ENCYCLOPEDIA OF
Global health
ENCYCLOPEDIA OF
global health YAWEI ZHANG general editor
Copyright © 2008 by SAGE Publications, Inc. All rights reserved. No part of this book may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying, recording, or by any information storage and retrieval system, without permission in writing from the publisher. Readers are advised and encouraged to seek either a professional opinion or a medical diagnosis for any condition they may have. For information: SAGE Publications, Inc. 2455 Teller Road Thousand Oaks, California 91320 E-mail: order @ sagepub.com SAGE Publications Ltd. 1 Oliver’s Yard 55 City Road London EC1Y 1SP United Kingdom SAGE Publications India Pvt. Ltd. B 1/ I 1 Mohan Cooperative Industrial Area Mathura Road, New Delhi 110 044 India SAGE Publications Asia-Pacific Pte. Ltd. 33 Pekin Street #02-01 Far East Square Singapore 048763 Library of Congress Cataloging-in-Publication Data Encyclopedia of global health/Yawei Zhang, general editor. p. ; cm. Includes bibliographical references and index. ISBN 978-1-4129-4186-0 (cloth : alk. paper) 1. World health—Encyclopedias. 2. Public health—Encyclopedias. 3. Medicine—Encyclopedias. I. Zhang, Yawei. [DNLM: 1. World Health—Encyclopedias—English. 2. Medicine—Encyclopedias—English. WA 13 E5566 2008] RA441.E53 2008 362.103—dc22
2007037954
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ENCYCLOPEDIA OF
Global health CoNteNtS
About the General Editor Introduction
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Reader’s Guide
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List of Articles
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List of Contributors Chronology
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Resource Guide Glossary Appendix Index
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Articles A to Z
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1779 1783 1841
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About the General Editor
Encyclopedia of Global Health About the General Editor
Yawei Zhang, M.D., Ph.D. Assistant Professor Yale University Division of Environmental Health Sciences Dr. Zhang received medical training at West China University of Medical Sciences between 1987 and 1993. After her graduation, she worked at Gansu Health Department, Lanzhou, China for about six years on several major public health studies, such as the National Children’s Nutrition Survey Study and the Children’s Immunization Program. These nationwide activities inspired her to further pursue research in the field of public health. In addition, her public health experience in China has also made her believe the importance of health education and the pursuit of research to advance the global understanding of the causes, treatment and prevention of disease. Dr. Yawei Zhang is currently an Assistant Professor at Yale University School of Public Health. Prior to her appointment at Yale, she obtained postdoctoral training at the National Cancer Institute. She received her Master’s degree and Ph.D. degree in Public Health at Yale University. As a cancer epidemiologist, Dr. Zhang has been conducting epidemiological studies of human cancer risk involving various cancers, including Hodgkin’s lymphoma and non-Hodgkin’s lymphoma, multiple myeloma, and cancers of the breast, testis, lung, and thyroid. During the past 10 years of research, she worked as Principal Investigator, CoInvestigator, Biostatistician, and Project Director for several major epidemiological studies investigating environmental exposures, endogenous hormones, genetic polymorphisms, and gene–environment interactions in the risk of human cancer. She is currently the Principal Investigator for epidemiological study of Quality of Life among Testicular Cancer Survivors. Dr. Zhang’s research has made a significant impact on cancer prevention and control as reflected in her scientific publications.
Introduction The contemporary understanding of global health is complicated and extends to all ends of the Earth and beyond. From the health effects of global warming to the implications of single nucleotide differences on disease, the factors that impact global health are extremely diverse and are changing constantly. As new scientific advances are made, as new policies are implemented, as wars are waged and peace agreements signed, or as new strains of infectious diseases evolve, the state of global health changes. Despite this dynamic and diverse system of knowledge, there are issues, people, discoveries, and advances that stand out as having made a significant impact on global health over the past centuries. This encyclopedia subsequently provides readers with a historical context for important changes and issues in global health and will serve as a foundation of knowledge. However, I invite you to use this information to inform your understanding of the current issues and challenges facing the field of global health and to participate in current global health discourse. The globalization of health began in the late fifteenth century when the European explorers discovered the Americas. Not only did the European explorers establish trade routes between Asia, Europe, and the Americas, they also geographically spread disease between continents. Soon after, they made connection between Africa and the Americas through slave trade, as well as many other areas of the world where
they traded. Over the past several decades, rapid development of economic, political, social, and cultural globalization and the easy access to high-speed forms of transportation have lead to an exponential rise in international travel. It has given rise to new patterns in the spread of infectious diseases. The recent outbreak of the virus SARS (Severe Acute Respiratory Syndrome) represents a good example of how new infectious diseases can spread globally in an unprecedented speed. Health officials in Hong Kong reported that within seven days, a man infected with SARS had flown from Hong Kong to Munich, Barcelona, Frankfurt, London, Munich again, Frankfurt again and then back to Hong Kong before entering a hospital. The man is believed to be responsible for spreading SARS to Europe. On the other hand, the international response to SARS highlights the importance of global scientific networks in addressing the problem of emergent infectious diseases. While it took two years to identify HIV as the cause of AIDs in 1980s, it took only two weeks to identify coronavirus as the cause of SARS in the recent outbreak because the World Health Organization (WHO) created a global network involving 13 laboratories in ten countries to work on the case of SARS. A number of new infectious diseases have emerged during the past several decades that can be attributed to the urbanization, deforestation, change in land use vii
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Introduction
and climate, population growth, poverty, political instability, and even terrorism. The rise of globalization has also lead to a rise in the incidence of non-communicable diseases through the adoption of unhealthy lifestyles, including stress, alienation and the aggressive marketing of fast foods, cigarettes, and alcohol. Although economic development and the introduction of modern medicine have reduced the incidence of infectious diseases and have made a general improvement in population health, the reduction of mortality from infectious diseases has been paralleled by an increase in non-communicable diseases, such as heart disease, diabetes, and cancer. This health transition experienced by most developing countries has been slower than the health transition in the more developed countries. Globalization has promoted uneven socioeconomic development in many developing countries, leading to rising incomes for certain sectors of the population and to lifestyle changes in these sectors that create a new health burden of noncommunicable diseases and injuries. Meanwhile the poorer sectors of the population whose incomes and lifestyles have not changes that much still suffer from the old health burden of infectious diseases and malnutrition. The Global Burden of Disease project by the World Bank and the WHO in the early 1990s provided evidence of the epidemiological transition of disease burden in developing countries, and predicted that causes of death attributable to non-communicable diseases are expected to rapidly increase while causes of death attributable to communicable, perinatal, maternal and nutritional causes will decline over the next couple of decades. The international health data in 1990 revealed that the heart disease, stroke, and cancer have replaced the major communicable diseases and malnutrition as the prime causes of death worldwide, and the total number of deaths from non-communicable disease causes was actually greater in the developing countries than in more-developed countries.
Infectious Diseases
Infectious diseases, also called communicable diseases, are characterized by the presence or activation of one or more pathogenic microbial agents, transmitted through contact with infected individuals, by water, food, airborne inhalation, or through vector-borne spread. Infectious diseases have historically been the leading cause of human morbidity and mortality. Over the past 150 years, the mortality due
to infectious diseases has declined substantially in developed countries, and non-communicable diseases such as cardiovascular disease, cancer, stroke, chronic obstructive pulmonary disease, and diabetes mellitus have become the leading causes of death in these countries. In the United States, only pneumonia, influenza, and HIV/AIDS, currently, rank among the top 10 causes of mortality. However, in developing countries, acute infectious diseases are the leading cause of death among children and young adults, and account for half of all deaths. It has been suggested that acute infectious diseases will decrease substantially during the next few decades. In addition, it is well documented that chronic infections plays an important role in pathogenesis of a number of chronic diseases, including cervical cancer (human papilloma virus [HPV]), hepatic cancer and cirrhosis (hepatitis B virus [HBV] and probably hepatitis C virus [HCV]), gastric cancer and peptic ulcer disease (Helicobacter pylori), and possible cardiovascular disease (Chlamydia pneumoniae or other infectious agents). A number of strategies have been employed to prevent morbidity and mortality from specific infectious diseases, including vector control (i.e., malaria, dengue, yellow fever, and onchocerciasis [river blindness]), vaccination (i.e., smallpox, measles, polio, neonatal tetanus, diphtheria, pertussis, tetanus, hepatitis B, meningococcal meningitis, and yellow fever), mass chemotherapy (i.e., hookworm, onchocerciasis, dracunculiasis [guinea worm], and sexually transmitted infections [STIs]), improved sanitation and access to clean water (i.e., diarrheal diseases), improved careseeking and caregiving (i.e., diarrheal diseases, acute respiratory infections, and neonatal tetanus), and behavior change (i.e., HIV and other STIs, diarrheal diseases, and dracunculiasis), among others. Through a combination of enhancements in case identification, containment, and vaccination, smallpox was successfully eradicated in the late 1970s worldwide. WHO and various partner agencies subsequently launched the Expanded Program of Immunizations (EPI) in 1974 to eradicate polio, dramatically reducing morbidity and mortality from measles and neonatal tetanus, and decreasing morbidity and mortality from diphtheria and pertussis worldwide. Furthermore, the success of HBV and HPV vaccination makes hepatic cancer and cirrhosis from HBV infection and cervical cancer from HPV a preventable chronic disease.
Non-communicable Diseases
Non-communicable diseases are also called chronic diseases, or degenerative diseases, which are characterized by complex risk factors, functional impairment or disability, with a prolonged course of illness and the unlikelihood of cure. While it has been a major public health concern in developed countries, non-communicable diseases are expected to become a big burden to developing countries during the next few decades. In 1990, epidemiologists found that non-communicable diseases such as heart disease, stroke, and cancer have replaced the major communicable diseases and malnutrition as the prime causes of death worldwide, and estimated that by 2020 non-communicable diseases will account for 7 of 10 deaths in developing countries. Considerable efforts have been made to investigate potential risk factors for non-communicable diseases since the 1950s. It is currently well accepted that tobacco use, alcohol consumption, dietary intake, and physical activity are the major principle lifestyle factors highly associated with non-communicable diseases morbidity and mortality. In addition, a number of other factors are also currently linked to the etiology of non-communicable diseases, including social class, culture, social networks, education, income, race, gender, and occupation, although the results from current available literatures are inconsistent. Cardiovascular disease refers to a group of diseases that involve heart and blood vessels. While it has been the leading cause of death and disability in industrialized countries, it is the second leading cause of death and disability among individuals in developing countries. In 2000, cardiovascular diseases accounted for 20 percent of all deaths worldwide. The mortality pattern varies by age, race, and gender. Not only is cardiovascular disease the major cause of death in older age groups and in men, it is also a very significant contributor to mortality in persons of economically productive ages (30–69 years) and in women. In the United States, cardiovascular disease mortality is higher in men than in women, and less for white men and women than for black men and women. Although cardiovascular disease has been widely studied in developed countries, information on diagnosis, treatment, and their natural history is sparse in developing countries. Cancer is the second leading cause of death in the United States. The global burden of cancer is currently unclear because of the limited information on
Introduction
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cancer incidence in developing countries. The International Agency for Research on Cancer (IARC) has produced numerous publications on cancer, including a detailed compilation of cancer incidence data from high-quality registries, which served as the basis for global estimation of cancer. The incidence rate of specific cancers varies between developed and developing countries. While cancers of the lung, breast, colon, and prostate are the most frequent types in the developed world, cancers of the mouth and oropharynx, stomach, and liver are the most common malignancies in the developing world. Although lung cancer is relatively less common in the developing countries, its incidence and mortality is increasing as tobacco smoking becomes more prevalent. One of the well-established risk factors for lung cancer is tobacco smoking, but it is the most difficult to control because tobacco products are a great source of revenue for businesses and a major source of tax revenue for many governments. It has been suggested that 81 percent of worldwide liver cancer is attributable to infectious with hepatitis B and C viruses and to parasites that invoke a chronic inflammatory process. Because these infectious agents are more prevalent in developing countries, liver cancer is more frequent in these countries. Hepatitis B is generally transmitted through sexual intercourse or mother to child. A vaccination against hepatitis B is available now and has been demonstrated to be effective in reducing the incidence of liver cancer. In developing countries, the state-of-the-art medical treatments with surgery or chemotherapeutic medicines are not widely available. As such, the major focus is on prevention rather than treatment. Although enormous resources are devoted to treating cancer in developed countries such as the United States, prevention efforts have also proven to be the most successful means of decreasing mortality from cancer over the past several decades. A recent publication by IARC demonstrated that differences in the average length of survival between developed and developing countries were greatest for certain cancers in which multiple therapy (radiation, surgery, and chemotherapy) is most effective, including testicular cancer, leukemia, and lymphoma that occur predominantly among younger individuals. However, for the most common preventable cancers such as those of the mouth, stomach, liver, and lung, uniformly poor survival outcomes in all registries including those in either developed or developing countries were observed.
Introduction
Diabetes has become enormously prevalent and is a major cause of disability worldwide. There are two major distinct types, (a) insulin-dependent diabetes mellitus or type 1 diabetes which is characterized by immune destruction of the cells of the pancreas that secrete insulin; and (b) noninsulin-dependent diabetes mellitus or type 2 diabetes which is characterized by a high level of serum glucose and elevated levels of insulin. Type 1 diabetes usually occurs in younger people and appears to have a strong genetic component. It has been shown that type 1 diabetes rates are the highest in Finland and Sweden and the lowest in Asian countries, Mexico, Chile, and Peru. In the United States, the disease rates are generally higher among the white population than black or Hispanic population, but the lowest among Native Americans. On the other hand, type 2 diabetes prevalence is increasing among populations experiencing modernization with decreases in physical activity and increases in average body mass. The high rates of type 2 diabetes have been observed in Pacific Islanders, Australian aborigines, Asian Indians, and certain subsets of Native Americans. Both types of diabetes can lead to major complications including blindness, renal failure, injuries and chronic infections of the extremities, or even large vessel disease, such as ischemic heart disease. As such, the WHO has identified diabetes as a major priority in non-communicable disease control. Injuries are among the leading causes of death and burden of diseases all over the world. Every day, almost 16,000 individuals die from injuries. Incidence and severity of injuries vary according to age, sex, race, occupation, as well as economic and geographic factors. Globally, injuries are an enormous toll for children, adolescents and young adults, and their associated death rates are higher among boys than among girls. The burden of injuries in developing countries differs from developed countries. China, Latin America, the Caribbean, sub-Saharan Africa are among the highest injury burden countries. Compared to intentional injuries, unintentional injuries conferred a much bigger health burden. Unintentional injuries are responsible for 5.2 percent of total deaths and account for 10–30 percent of all hospital admissions. The leading cause of injury deaths is motor-vehicle accidents globally, then suicide, homicide, drowning, war-related injuries, falls, burns, and poisonings. Although motor-vehicle injuries are preventable, declines in incidence have not been observed around the world. In fact, increases during the next few years are expected because a number of factors that con-
tribute to motor-vehicle injuries are still issues particularly in for developing countries, including rapid population growth, increasing motorization, little access to emergency care, lack of safety features in cars, crowded roads, poor road maintenance, and lack of police enforcement.
Mental Health
Mental health has received little attention historically because of its limited mortality. However, a recent assessment using the disability-adjusted life years (DALYs) as an indicator of the burden of disease has underscored the importance of mental health and stimulated reexamination of international health priorities. In developing countries, five of the ten leading causes of disability among persons 15–44 years are mental health and behavioral problems. All together, these five conditions account for almost 22 percent of all DALYs in the most productive years of life. While mental health and related conditions accounted for 10.5 percent of the disease burden with an additional 1.5 percent attributed to intentional injuries in developing countries, they accounted for 23.5 percent with an additional 2.2 percent attributed to intentional injuries in developed countries. It has been estimated that mental health and related conditions in developing countries are increasing toward the level in developed countries.
The Encyclopedia
The Encyclopedia of Global Health is a comprehensive A to Z, interdisciplinary, one-stop reference to a broad array of health topics worldwide. It covers all aspects of health including physical and mental health entries, current health status in each country of the five continents, biographies of major doctors and researchers, profiles of major medical institutes, organizations, corporations, and foundations, descriptions of major drugs and operations, articles on national health policies, and thematic health topics in the humanities. Pedagogical elements of the encyclopedia include an in-depth chronology detailing advances in health through history, a glossary of health definitions, extensive cross-references to related topics, and thorough bibliographic citations. Not only is the Encyclopedia of Global Health a useful reference for health professionals, but also for general populations. Yawei Zhang General Editor
Reader’s Guide This list is provided to assist readers in finding articles related by category or theme. CHILDREN’S HEALTH
Adolescent Development Adolescent Health Adoption Medicine Alcohol and Youth Asthma in Children Birth Defects Breech Birth Child Abuse Child Behavior Disorders Child Dental Health Child Development Child Mental Health Child Safety Childhood Cancers Childhood Immunization Diabetes Type I (Juvenile Diabetes) Dysmorphology Exercise for Children Failure to Thrive Fetal Alcohol Syndrome Hearing Problems in Children Infant and Newborn Care Infant and Toddler Development Infant and Toddler Health Juvenile Rheumatoid Arthritis Neonatologist Neonatology
Pediatrics Premature Babies Prenatal Care Rickets Smoking and Youth Spina Bifida Sudden Infant Death Syndrome Tanner Stages
COUNTRIES: AFRICA
Algeria Angola Benin Botswana Brunei Darussalam Burkina Faso Burundi Cameroon Cape Verde Central African Republic Chad Comoros Congo Congo, Democratic Republic Côte d’Ivoire Djibouti Egypt Equatorial Guinea
Eritrea Ethiopia Gabon Gambia Ghana Guinea Guinea-Bissau Kenya Lesotho Liberia Madagascar Malawi Mali Mauritania Mauritius Morocco Mozambique Namibia Niger Nigeria Rwanda São Tomé and Principe Senegal Sierra Leone Somalia South Africa Sudan Swaziland
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Tanzania Togo Tunisia Uganda Zambia Zimbabwe
Antigua and Barbuda Argentina Bahamas Barbados Belize Bolivia Brazil Canada Chile Colombia Costa Rica Cuba Dominica Dominican Republic Ecuador El Salvador Grenada Guatemala Guyana Haiti Honduras Jamaica Mexico Nicaragua Panama Paraguay Peru Saint Kitts and Nevis Saint Lucia Saint Vincent and the Grenadines Suriname Trinidad and Tobago United States Statistics Uruguay Venezuela
China East Timor Georgia India Indonesia Iran Iraq Israel Japan Jordan Kazakhstan Korea, North Korea, South Kuwait Kyrgyzstan Laos Lebanon Malaysia Maldives Moldova Mongolia Myanmar Nepal Oman Pakistan Palestine Philippines Qatar Russia Saudi Arabia Seychelles Singapore Sri Lanka Syria Tajikistan Thailand Turkey Turkmenistan Ukraine United Arab Emirates Uzbekistan Vietnam Yemen
COUNTRIES: ASIA
COUNTRIES: EUROPE
COUNTRIES: AMERICAS
Afghanistan Azerbaijan Bahrain Bangladesh Bhutan Cambodia
Albania Andorra Armenia Austria Belarus Belgium
Bosnia and Herzegovina Bulgaria Croatia Cyprus Czech Republic Denmark Estonia Finland France Germany Greece Hungary Iceland Ireland Italy Latvia Liechtenstein Lithuania Luxembourg Macedonia FYROM Malta Monaco Netherlands Norway Poland Portugal Romania San Marino Serbia and Montenegro Slovakia Slovenia Spain Sweden Switzerland United Kingdom
COUNTRIES: PACIFIC Australia Fiji Kiribati Marshall Islands Micronesia Nauru New Zealand Palau Papua New Guinea Samoa Solomon Islands Tonga Tuvalu Vanuatu
Reader’s Guide
DISEASES, CANCERS
Adrenocortical Carcinoma Anal Cancer Bile Duct Cancer Bladder Cancer Bone Cancer Brain Cancer Breast Cancer Cancer (General) Carcinoid Tumors Carcinoma of Unknown Primary Colorectal Cancer Esophageal Cancer Extragonadal Germ Cell Tumor Eye Cancer Gallbladder Cancer Head and Neck Cancer Hodgkin’s Lymphoma Kidney Cancer Leukemia Liver Cancer Lung Cancer Malignant Mesothelioma Multiple Myeloma Neuroblastoma Non-Hodgkin Lymphoma Oncologist Oncology Oral Cancer Osteonecrosis Ovarian Cancer Pancreatic Cancer Penile Cancer Pheochromocytoma Pituitary Tumor Prostate Cancer Skin Cancer Small Intestine Cancer Soft Tissue Sarcoma Stomach Cancer Testicular Cancer Thymus Cancer Thyroid Cancer Uterine Cancer Vaginal Cancer Vulvar Cancer
DISEASES, LOCALIZED Acid Reflux Acne Acoustic Neuroma
Age-Related Macular Degeneration Alzheimer’s Disease Amblyopia Anal/Rectal Diseases Aneurysms Angina Aphasia Appendicitis Arrhythmia Arteriosclerosis Asbestos/Asbestosis Asthma Back Injuries Back Pain Bell’s Palsy Birthmark Bladder Diseases Blepharitis Blepharospasm Blindness Bone Diseases Bone Marrow Diseases Brain Diseases Brain Injuries Brain Malformations Breast Diseases Breathing Problems Bronchitis Carpal Tunnel Syndrome Cataract Celiac Disease Cellulitis Chlamydia Infections Chronic Obstructive Pulmonary Disease (COPD) Cirrhosis Cleft Lip and Palate Colon Polyps Colonic Diseases (General) Concussion Congenital Heart Disease Conjunctivitis Connective Tissue Disorders Constipation Cornea and Corneal Disease Coronary Disease Deafness Dental Health Dermatitis Diabetic Eye Problems Diabetic Foot
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Diabetic Kidney Problems Diabetic Nerve Problems Diabetic Teeth and Gum Problems Diarrhea Digestive Diseases (General) Diverticulosis and Diverticulitis Dysphagia Ear Disorders Ear Infections Elbow Injuries and Disorders Emphysema Esophagus Disorders Eye Diseases (General) Facial Injuries and Disorders Foot Health Foot Injuries and Disorders Fractures Gallbladder and Bile Duct Diseases Gastroesophageal Reflux/Hiatal Hernia Gastrointestinal Bleeding Genetic Brain Disorders Genital Herpes Glaucoma Glomerular Diseases Goiter Gonorrhea Gout and Pseudogout Gum Disease Hair Diseases and Hair Loss Hand Injuries and Disorders Head and Brain Injuries Head and Brain Malformations Head Lice Headache and Migraine Heart Attack Heart Diseases (General) Heart Valve Diseases Hemorrhoids Hepatitis Hepatitis C Hernia Hip Injuries and Disorders Huntington’s Disease Hydrocephalus Impetigo Incontinence Inflammatory Bowel Disease Intestinal Parasites Irritable Bowel Syndrome Kidney Diseases (General) Kidney Failure and Dialysis
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Kidney Stones Knee Injuries and Disorders Leg Injuries and Disorders Liver Diseases (General) Low Vision Meniere’s Disease Mouth Disorders Neck Disorders and Injuries Neural Tube Defects Nose Disorders Onchocerciasis Paget’s Disease of Bone Pancreatic Diseases Peptic Ulcer Pneumonia Polycystic Kidney Disease Pulmonary Embolism Pulmonary Fibrosis Raynaud’s Disease Respiratory Diseases (General) Retinal Disorders Rheumatic Heart Disease Rosacea Salivary Gland Disorders Scoliosis Severe Acute Respiratory Syndrome (SARS) Shoulder Injuries and Disorders Sinusitis Skin Diseases (General) Skin Pigmentation Disorders Spinal Cord Diseases Spinal Cord Injuries Spinal Muscular Atrophy Spinal Stenosis Spleen Diseases Stomach Disorders Taste and Smell Disorders Temporomandibular Joint Dysfunction Thoracic Outlet Syndrome Throat Disorders Thyroid Diseases Tinnitus Trachoma Tuberculosis Ulcers Urinary Tract Infections Usher Syndrome Vitiligo Voice Disorders Wrist/Arm Injuries and Disorders
DISEASES, SYSTEMIC
Acquired Mutation Addison’s Disease AIDS AIDS and Infections AIDS-Related Malignancies Alcoholism Allergy Anemia Anorexia Nervosa Arthritis Autoimmune Diseases (General) Bacterial Infections Beriberi Bird Flu Bleeding Disorders Botulism Bulimia Bursitis Cerebral Palsy Chagas Disease Chickenpox Cholera Chronic Fatigue Syndrome Coma Common Cold Cystic Fibrosis Degenerative Nerve Diseases Dengue Developmental Disabilities Diabetes Diabetes Type II Diphtheria Disabilities (General) Dizziness and Vertigo Down Syndrome Dystonia Eating Disorders E. Coli Infections Edema Ehlers-Danlos Syndrome Endocrine Diseases (General) Epilepsy Fainting Fever Filariasis / Elephantiasis Food Allergy Foodborne Diseases Fungal Infections Gaucher’s Disease Genetic Disorders
Germline Mutation Giardia Infections Growth Disorders Guillain-Barre Syndrome Hemorrhagic Fever Herpes Simplex High Blood Pressure Hyperactivity Hypoglycemia Hypothermia Immune System and Disorders Infectious Diseases (General) Influenza Klinefelter’s Syndrome Kwarshiorkor Lactose Intolerance Lead Poisoning Legionnaire’s Disease Leishmaniasis Leprosy Leukodystrophies Lou Gehrig’s Disease Low Blood Pressure Lupus Lyme Disease Lymphatic Diseases Malaria Marasmus Marfan Syndrome Measles Meningitis Metabolic Disorders Missense Mutation Movement Disorders Multiple Chemical Sensitivity Multiple Sclerosis Mumps Muscle Disorders Muscular Dystrophy Myasthenia Gravis Myositis Nausea and Vomiting Neurofibromatosis Neurologic Diseases (General) Neuromuscular Disorders Nonsense Mutation Osteoarthritis Osteogenesis Imperfecta Pain Paralysis Parasitic Diseases
Reader’s Guide
Parathyroid Disorders Parkinson’s Disease Peripheral Nerve Disorders Phenylketonuria Pituitary Disorders Point Mutation Poisoning Polio and Post-Polio Syndrome Polymyalgia Rheumatica Porphyria Prader-Willi Syndrome Psoriasis Rabies Reflex Sympathetic Dystrophy Rett Syndrome Reye Syndrome Rheumatoid Arthritis Rubella Salmonella Infections Sarcoidosis Scleroderma Seizures Sexually Transmitted Diseases Shingles (Herpes Zoster) Shistosomiasis Sickle Cell Anemia Sjogren’s Syndrome Smallpox Somatic Mutation Staphylococcal Infections Streptococcal Infections Stress Stroke Tay-Sachs Disease Tetanus Tourette Syndrome Transient Ischemic Attack Tremor Tuberous Sclerosis Turner’s Syndrome Typhoid Vasculitis Viral Infections Whooping Cough Wilson’s Disease
DRUGS AND DRUG COMPANIES Adult Immunization Amphetamines Anabolic Steroids Antibiotics
Drug and Medical Device Safety Generic Drug Immunization/Vaccination Inhalants Maintenance Medication Me-Too Drug Over-the-Counter (OTC) Drug Pharmaceutical Industry (Worldwide) Pharmacist Pharmaco-epidemiology Pharmacogenetics Pharmacogenomics Pharmacologist Pharmacology Pharmacopeia/Pharmacopoeia Pharmacy Placebo Prescription Drugs Abuse United States Pharmacopeia and National Formulary (USP-NF)
HEALTH SCIENCES
Acquired Immunity Active Immunity Activities of Daily Living (ADLs) Aerospace Medicine African American Health AIDS, Living with Air Pollution Alcohol Consumption Allele Allopathy Alpha Error Alternative Medicine Alzheimer’s Caregivers Amputees Anthrax Antioxidants Artificial Limbs Asian American Health Background Radiation Bacteriology Base Excision Repair Base Pair Base Sequence Beta Error Biochemistry Biodefense Bioinformatics Biological and Chemical Weapons Biomarker
Biosafety Bioterrorism Birth Cohort Birth Rate Bisexual Body Cell Mass Body Mass Index Body Surface Area Bone Health Bone Mass Density Bone Mineral Density Brown Fat Burns Caffeine Calcium Cancer—Coping with Cancer Cardiologist Cardiology Caregivers Carotenoid Cascade Centenarian Cervical Spine Chemokine Chemokinesis Chinese Medicine, Traditional Cholesterol Chromosome Chronology of Global Health Circadian Clone Club Drugs Cocaine Abuse Coefficient of Inbreeding Complex Humanitarian Emergencies Conventional Medicine Cosmetics Craniology Crossing Over Crude Mortality Rate Cytogenetics Cytokine Daily Reference Values (DRVs) Date Rape Death and Dying Death Rate Demographic Transition Diesel Exhaust Dieting Disasters and Emergency Preparedness Disease and Poverty
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Disease Prevention Dizygotic Twin DNA DNA Repair Drinking Water Drug Abuse Dyslexia Ecogenetics Ectoparasites Elder Abuse Electromagnetic Fields Electrophysiology Empiric Risk Endemic Endocrinology Engram Environmental Health Environmental Medicine Environmental Tobacco Smoke (ETS) Environmental Toxicology Epidemic Epidemiologist Epidemiology Epigenetics Evidence-Based Medicine Exercise for Seniors Exercise/Physical Fitness Eye Care Falls False Negative False Positive First American Medical School Flea Bites Fluoride Folic Acid Food Contamination/Poisoning Food Safety Forensic Medicine Fraternal Twins Gastroenterologist Gastroenterology Gay Gene Gene Pool Genetic Code Genetics Genomic Library Genotype Geriatrics Gerontology Global Health Ethics Hair Dye
Haploid Hardy-Weinberg Law Healthcare, Africa Healthcare, Asia and Oceania Healthcare, Europe Healthcare, South America Healthcare, U.S. and Canada Heart Diseases—Prevention Heat Index Hematologist Hematology Hemizygous Hemochromatosis Herbal Medicine Herbal Remedy Herbalism Herbalist Heroin Abuse Heterosexual Heterozygote Hispanic American Health Histology Homeopathy Homicide Homosexual Homozygote Hormones Household Poisons Hygiene Immunologist Immunology In Situ In Vitro In Vivo Inbreeding Incidence Indoor Air Pollution Infertility Innate Immunity Inpatient Institutional Review Board (IRB) Internal Medicine Internist Iridology Knockout Lean Body Mass Learning Disorders Lesbian Linkage Analysis Linkage Map Locus
Malariologist Malariology Marijuana Abuse Medical College Admissions Test (MCAT) Medical Entomology Medical Geography Medical Helminthology Medical Jurisprudence Medical Physics Medical Prefix Medical Tourism Memory Mercury Meta-analysis Methamphetamine Abuse Methylation Mismatch Repair Molds Monozygotic Twin Mortality Mosquito Bites Native American Health Naturopathy Nephrologist Nephrology Neuroendocrinology Neurologist Neurology Neuropsychologist Neuroradiologist Neuroradiology Neuroscience Neuroscientist Noise Nuclear Medicine Nutrition Nutritionist Obesity Occupational Health Occupational Injuries Occupational Medicine Ophthalmologist Ophthalmology Optometrist Oral Surgeon Organ Donation Orthomolecular Medicine Orthopedics Orthopedist Osteopathy Otolaryngologist
Reader’s Guide
Otolaryngology Otology Outpatient Ozone Passive Immunity Pasteurization Pathologist Pathology Pathophysiology Perinatologist Perinatology Pesticides Phenotype Phrenology Phylogenetics Physiatrist Physical Therapist Physiology Piercing and Tattoos Podiatrist Pollution Polymerase Chain Reaction (PCR) Polymorphism Prevalence Preventive Care Primary Care Proctology Programmed Cell Death Pulmonology Radiation Exposure Radiologist Radiology Radon Rare Diseases Refractive Errors Refugee Health Rehabilitation Reproductive Health (General) Roentgenology Safety (General) Satellite DNA Saturated Fat Sleep Disorders Smokeless Tobacco Smoking Smoking Cessation Snellen’s Chart Speech & Communication Disorders Spider Bites Sports Injuries Sprains and Strains
Sun Exposure Sun Protection Factor (SPF) Telepathology Third World Tick Bites Toxicology Trans Fat Travel Medicine Traveler’s Health Tropical Medicine Tumor Registry Ultraviolet Radiation United States Medical Licensing Examination (USMLE) United States Statistics Universal Donor Unsaturated Fat Urological Surgeon Urologist Virology Vitamin A Deficiency Vitamin and Mineral Supplements West Nile Virus
MEN’S HEALTH
AIDS Bisexual Breast Cancer Heterosexual Homosexual Hormones Impotence Infertility Male Genital Disorders Penile Cancer Prostate Cancer Prostate Diseases Reproductive Health (General) Testicular Cancer Urinary Tract Infections
MENTAL HEALTH
Anxiety Disorders Attention Deficit Disorder Attention Deficit Disorder with Hyperactivity Autism Bereavement Dementia Depression
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Manic-Depressive Illness Mental Health Obsessive-Compulsive Disorder Psychiatrist Psychiatry Psychoimmunology Psychologist Psychology Psychoneuroimmunology Psychooncology Psychotherapy Schizophrenia Suicide
ORGANIZATIONS AND ASSOCIATIONS
Adult Congenital Heart Association (ACHA) Alzheimer’s Association Alzheimer’s Disease Education and Referral Center (ADEAR) American Academy of Addiction Psychiatry (AAAP) American Academy of Family Physicians (AAFP) American Academy of Nurse Practitioners (AANP) American Academy of Ophthalmology (AAO) American Academy of Orthopedic Surgeons (AAOS) American Academy of Pediatrics (AAP) American Association for Cancer Research (AACR) American Association for Health Education (AAHE) American Association of Orthodontists (AAO) American Cancer Society (ACS) American College Health Association (ACHA) American College of Epidemiology (ACE) American College of Nurse-Midwives (ACNM) American College of Obstetricians and Gynecologists (ACOG) American College of Occupational and Environmental Medicine (ACOEM) American College of Physicians (ACP) American College of Preventive Medicine (ACPM)
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Reader’s Guide
American College of Sports Medicine (ACSM) American College of Surgeons (ACS) American Council for Fitness and Nutrition (ACFN) American Dental Association (ADA) American Dental Hygienists’ Association (ADHA) American Diabetes Association (ADA) American Fertility Association (AFA) American Geriatrics Society (AGS) American Health Care Association (AHCA) American Heart Association (AHA) American Lung Association American Medical Association (AMA) American Medical Women’s Association (AMWA) American Nurses Association (ANA) American Obesity Association (AOA) American Osteopathic Association American Pharmaceutical Association (APhA) American Podiatric Medical Association (APMA) American Pregnancy Association (APA) American Psychological Association (APA) American Public Health Association (APHA) American Red Cross American Social Health Association (ASHA) American Society for Reproductive Medicine (ASRM) American Society of Clinical Oncology (ASCO) American Society of Clinical Pathologists (ASCP) American Society of Human Genetics (ASHG) American Society on Aging (ASA) American Urological Association (AUA) Association for International Cancer Research (AICR) Association of Maternal and Child Health Programs (AMCHP) Association of Schools of Public Health (ASPH) Association of Women’s Health, Obstetric and Neonatal Nurses (AWHONN)
European Association for Cancer Research (EACR) European Association for the Study of Obesity (EASO) Fondation Jean Dausset (CEPH) Human Genome Organisation (HUGO) Institute for Children’s Environmental Health (ICEH) Institute of Medicine (IOM) International AIDS Vaccine Initiative (IAVI) International Center for Equal Healthcare Access (ICEHA) International Classification of Diseases (ICD) International Clinical Epidemiology Network (INCLEN) International Committee of the Red Cross (ICRC) International Council of AIDS Service Organizations (ICASO) International Epidemiological Association (IEA) International Federation of Red Cross and Red Crescent Societies (IFRC) International Genetic Epidemiology Society (IGES) International Red Cross and Red Crescent Movement (RCRC) International Society for Environmental Epidemiology (ISEE) International Society for Pharmacoepidemiology (ISPE) International Society of Geographical and Epidemiological Ophthalmology (ISGEO) International Women’s Health Coalition (IWHC) MedicAlert Médicins Sans Frontières National Asian Women’s Health Organization (NAWHO) National Association of Health Data Organizations (NAHDO) National Association of People with AIDS (NAPWA) National Breast Cancer Coalition (NBCC) National Coalition for Cancer Survivorship (NCCS) National Environmental Health Association (NEHA)
National Mental Health Association (NMHA) National Network for Immunization Information (NNii) National Women’s Health Organization (NWHO) North American Association for the Study of Obesity (NAASO) Pasteur Institute School Nutrition Association (SNA) Society for Healthcare Epidemiology of America (SHEA) Society for Nutrition Education (SNE) Society for Public Health Education (SOPHE) Voluntary Euthanasia Society (VES)
PEOPLE
Abse, Dannie Ames, Bruce N. Avery, Oswald Theodore Axelrod, Julius Beals, Rodney K. Beijerinck, Martinus W. Bell, Charles Blackwell, Elizabeth Bross, Irwin D.J. Brown, Louise Brown, Michael Stuart Calabresi, Paul Casals-Ariet, Jordi Chekhov, Anton Chen, Zhong Wei Crick, Francis Da Vinci, Leonardo Darwin, Charles Ehrlich, Paul Farmer, Paul Fredrickson, Donald Gage, Phineas Galton, Sir Francis Gibbon, John H., Jr. Hardy, James D. Hounsfield, Godfrey Hughlings Jackson, John Kelman, Charles D. Kirklin, John W. Kübler-Ross, Elisabeth La Montagne, John Lauterbur, Paul C. Lederberg, Joshua
Reader’s Guide
Lewis, Edward B. Mansfield, Peter Marx, Gertie F. McClintock, Barbara Mead, Margaret Moscati, St. Joseph Nirenberg, Marshall W. Osler, Sir William Parkinson, James Pasteur, Louis Pauling, Linus Ramsay Hunt, James Rodbell, Martin Roentgen, Wilhelm Sabin, Albert Sabin, Florence R. Sachs, Jeffrey Schweitzer, Albert Soper, Fred L. Stewart, Alice Stickler, Gunnar B. Thomas, Lewis Thorn, George W. Varco, Richard L. Warshaw, Joseph Watson, James Wilkins, Lawson Zoll, Paul M.
PROCEDURES AND THERAPIES Acupuncture Allograft Angioplasty Biofeedback Biotherapy Blood/Blood Transfusion Cancer Alternative Therapy Cancer Chemotherapy Cancer Radiation Therapy Cardioversion Chemoprevention Chemoradiotherapy Chemotherapy Chiropractic Cryopreservation Cryosurgery Diagnostic Imaging Diagnostic Tests Dialysis Enzyme-Linked Immunosorbent Assay (ELISA)
Exercise Treadmill Test Gamete Intrafallopian Transfer (GIFT) Gel Electrophoresis Gene Array Analysis Gene Mapping Gene Silencing Gene Transfer Genes and Gene Therapy Genetic Testing/Counseling Genetic Transformation Genomic Imprinting Heart Bypass Surgery Heart Transplantation Immunosuppression Immunotherapy Kidney Transplantation Laboratory Tests Liver Transplantation Lung Transplantation Microsurgery Oral Rehydration Therapy Organ Transplantation Pancreas Transplantation Stem Cells/Stem Cell Transplantation Surgery Telesurgery
RESEARCH
Case-Control Study Clinical Trial Cohort Study Cross-Sectional Study Crossover Study Double-Blinded Study Framingham Heart Study Longitudinal Study Nurses’ Health Study Prospective Study Randomized Clinical Trial Retrospective Study SEER (Surveillance, Epidemiology, and End Results Program)
SOCIETY AND HEALTH
Administration on Aging (AoA) Administration for Children and Families (ACF) Agency for Healthcare Research and Quality (AHRD) Agency for Toxic Substances and Disease Registry (ATSDR)
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Center for Food Safety and Applied Nutrition (CFSAN) Centers for Disease Control and Prevention (CDC) Centers for Medicare and Medicaid Services (CMS) Department of Energy (DOE) Department of Health and Human Services (HHS) Drug Enforcement Administration (DEA) Employment Retirement Income Security Act (ERISA) Environmental Protection Agency (EPA) European Food Safety Authority (EFSA) European Public Health Alliance (EPHA) European Public Health Association (EUPHA) Federal Emergency Management Agency (FEMA) Fee-for-Service Food and Drug Administration (FDA) Food and Agriculture Organization of the United Nations (FAO) Global Health Council Health Insurance Portability and Accountability Act (HIPAA) Health Maintenance Organization (HMO) Health Resources and Services Administration (HRSA) Indian Health Service (IHS) Insurance International Agency for Research on Cancer (IARC) International Health Ministries Office (IHMO) Joint FAO/WHO Expert Committee on Food Additives (JECFA) Joint United Nations Programme in HIV/ AIDS (UNAIDS) Managed Care Medical Research Council Medicaid Medicare Medigap Policy MEDLINE Mine Safety and Health Administration (MSHA) National Cancer Institute (NCI) National Center for Chronic Disease Prevention and Health Promotion (NCCDPHP)
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Reader’s Guide
National Center for Complementary and Alternative Medicine (NCCAM) National Center for Environmental Health (NCEH) National Center for Health Marketing (NCHM) National Center for Health Statistics (NCHS) National Center for HIV, STD, and TB Prevention (NCHSTP) National Center for Infectious Diseases (NCID) National Center for Injury Prevention and Control (NCIPC) National Center for Public Health Informatics (NCPHI) National Center on Birth Defects and Developmental Disabilities (NCBDDD) National Cholesterol Education Program (NCEP) National Eye Institute (NEI) National Heart, Lung, and Blood Institute (NHLBI) National Human Genome Research Institute (NHGRI) National Immunization Program (NIP) National Institute of Allergy and Infectious Diseases (NIAID) National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS) National Institute of Biomedical Imaging and Bioengineering (NIBIB) National Institute of Children’s Health (NICHD) National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) National Institute of Environmental Health Sciences (NIEHS)
National Institute of Mental Health (NIMH) National Institute of Neurological Disorders and Stroke (NINDS) National Institute of Nursing Research (NINR) National Institute of Occupational Safety and Health (NIOSH) National Institute on Aging (NIA) National Institute on Alcohol Abuse and Alcoholism (NIAAA) National Institute on Deafness and Other Communication Disorders (NIDCD) National Institute on Drug Abuse (NIDA) National Institutes of Health (NIH) National Library of Medicine (NLM) National Program of Cancer Registries (NPCR) Occupational Safety and Health Administration (OSHA) Pan American Health Organization (PAHO) Point of Service (POS) Preferred Provider Organization (PPO) Public Health Substance Abuse and Mental Health Services Administration (SAMHSA) United Nations Children’s Fund (UNICEF) United Network for Organ Sharing (UNOS) United States Public Health Service World Health Organization (WHO)
WOMEN’S HEALTH
Abortion AIDS AIDS and Pregnancy Birth Control/Contraception Bisexual Breast Cancer
Breast Feeding Breast Implants/Breast Reconstruction Cervical Cancer Climacteric Diabetes and Pregnancy Doula Estrogen Replacement Therapy (ERT) Female Circumcision Gynecologist Gynecology Heterosexual High Risk Pregnancy Hormone Replacement Therapy Hormones Infertility Lesbian Menopause Menstruation and Premenstrual Syndrome Midwife Obstetric Fistula Obstetrician/Gynecologist Obstetrics Osteoporosis Ovarian Cancer Postpartum Depression Preeclampsia Pregnancy Pregnancy and Substance Abuse Pregnancy Loss Reproductive Health (General) Smoking and Pregnancy Teenage Pregnancy Urinary Tract Infections Uterine Cancer Uterine Diseases Vaginal Cancer Vaginal Diseases Vulvar Cancer Women’s Health (General)
List of Articles A
Abortion Abse, Dannie Acid Reflux Acne Acoustic Neuroma Acquired Immunity Acquired Mutation Active Immunity Activities of Daily Living (ADLs) Acupuncture Addison’s Disease Administration for Children and Families (ACF) Administration on Aging (AoA) Adolescent Development Adolescent Health Adoption Medicine Adrenocortical Carcinoma Adult Congenital Heart Association (ACHA) Adult Immunization Aerospace Medicine Afghanistan African American Health Age-Related Macular Degeneration Agency for Healthcare Research and Quality (AHRD)
Agency for Toxic Substances and Disease Registry (ATSDR) AIDS AIDS and Infections AIDS and Pregnancy AIDS, Living with AIDS-Related Malignancies Air Pollution Albania Alcohol and Youth Alcohol Consumption Alcoholism Algeria Allele Allergy Allograft Allopathy Alpha Error Alternative Medicine Alzheimer’s Association Alzheimer’s Caregivers Alzheimer’s Disease Alzheimer’s Disease Education and Referral Center (ADEAR) Amblyopia American Academy of Addiction Psychiatry (AAAP) American Academy of Family Physicians (AAFP)
American Academy of Nurse Practitioners (AANP) American Academy of Ophthalmology (AAO) American Academy of Orthopedic Surgeons (AAOS) American Academy of Pediatrics (AAP) American Association for Cancer Research (AACR) American Association for Health Education (AAHE) American Association of Orthodontists (AAO) American Cancer Society (ACS) American College Health Association (ACHA) American College of Epidemiology (ACE) American College of Nurse-Midwives (ACNM) American College of Obstetricians and Gynecologists (ACOG) American College of Occupational and Environmental Medicine (ACOEM) American College of Physicians (ACP) American College of Preventive Medicine (ACPM) American College of Sports Medicine (ACSM) American College of Surgeons (ACS)
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List of Articles
American Council for Fitness and Nutrition (ACFN) American Dental Association (ADA) American Dental Hygienists’ Association (ADHA) American Diabetes Association (ADA) American Fertility Association (AFA) American Geriatrics Society (AGS) American Health Care Association (AHCA) American Heart Association (AHA) American Lung Association American Medical Association (AMA) American Medical Women’s Association (AMWA) American Nurses Association (ANA) American Obesity Association (AOA) American Osteopathic Association American Pharmaceutical Association (APhA) American Podiatric Medical Association (APMA) American Pregnancy Association (APA) American Psychological Association (APA) American Public Health Association (APHA) American Red Cross American Social Health Association (ASHA) American Society for Reproductive Medicine (ASRM) American Society of Clinical Oncology (ASCO) American Society of Clinical Pathologists (ASCP) American Society of Human Genetics (ASHG) American Society on Aging (ASA) American Urological Association (AUA) Ames, Bruce N. Amphetamines Amputees Anabolic Steroids Anal Cancer Anal/Rectal Diseases Andorra Anemia Aneurysms Angina Angioplasty
Angola Anorexia Nervosa Anthrax Antibiotics Antigua and Barbuda Antioxidants Anxiety Disorders Aphasia Appendicitis Argentina Armenia Arrhythmia Arteriosclerosis Arthritis Artificial Limbs Asbestos/Asbestosis Asian American Health Association for International Cancer Research (AICR) Association of Maternal and Child Health Programs (AMCHP) Association of Schools of Public Health (ASPH) Association of Women’s Health, Obstetric and Neonatal Nurses (AWHONN) Asthma Asthma in Children Attention Deficit Disorder Attention Deficit Disorder with Hyperactivity Australia Austria Autism Autoimmune Diseases (General) Avery, Oswald Theodore Axelrod, Julius Azerbaijan
B
Background Radiation Back Injuries Back Pain Bacterial Infections Bacteriology Bahamas Bahrain Bangladesh Barbados Base Excision Repair Base Pair Base Sequence
Beals, Rodney K. Beijerinck, Martinus W. Belarus Belgium Belize Bell, Charles Bell’s Palsy Benin Bereavement Beriberi Beta Error Bhutan Bile Duct Cancer Biochemistry Biodefense Biofeedback Bioinformatics Biological and Chemical Weapons Biomarker Biosafety Bioterrorism Biotherapy Bird Flu Birth Cohort Birth Control/Contraception Birth Defects Birth Rate Birthmark Bisexual Blackwell, Elizabeth Bladder Cancer Bladder Diseases Bleeding Disorders Blepharitis Blepharospasm Blindness Blood/Blood Transfusion Body Cell Mass Body Mass Index Body Surface Area Bolivia Bone Cancer Bone Diseases Bone Health Bone Marrow Diseases Bone Mass Density Bone Mineral Density Bosnia and Herzegovina Botswana Botulism
List of Articles
Bovine Spongiform Encephalopathy Brain Cancer Brain Diseases Brain Injuries Brain Malformations Brazil Breast Cancer Breast Diseases Breast Feeding Breast Implants/Breast Reconstruction Breathing Problems Breech Birth Bronchitis Bross, Irwin D.J. Brown, Louise Brown, Michael Stuart Brown Fat Brunei Bulgaria Bulimia Burkina Faso Burns Bursitis Burundi
C
Caffeine Calabresi, Paul Calcium Cambodia Cameroon Canada Cancer (General) Cancer Alternative Therapy Cancer Chemotherapy Cancer Radiation Therapy Cancer—Coping with Cancer Cape Verde Carcinoid Tumors Carcinoma of Unknown Primary Cardiologist Cardiology Cardioversion Caregivers Carotenoid Carpal Tunnel Syndrome Casals-Ariet, Jordi Cascade Case-Control Study Cataract Celiac Disease
Cellulitis Centenarian Center for Food Safety and Applied Nutrition (CFSAN) Centers for Disease Control and Prevention (CDC) Centers for Medicare and Medicaid Services (CMS) Central African Republic Cerebral Palsy Cervical Cancer Cervical Spine Chad Chagas Disease Chekhov, Anton Chemokine Chemokinesis Chemoprevention Chemoradiotherapy Chemotherapy Chen, Zhong Wei Chickenpox Child Abuse Child Behavior Disorders Child Dental Health Child Development Child Mental Health Child Safety Childhood Cancers Childhood Immunization Chile China Chinese Medicine, Traditional Chiropractic Chlamydia Infections Cholera Cholesterol Chromosome Chronic Fatigue Syndrome Chronic Obstructive Pulmonary Disease (COPD) Chronology of Global Health Circadian Cirrhosis Cleft Lip and Palate Climacteric Clinical Trial Clone Club Drugs Cocaine Abuse Coefficient of Inbreeding
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Cohort Study Colombia Colonic Diseases (General) Colon Polyps Colorectal Cancer Coma Common Cold Comoros Complex Humanitarian Emergencies Concussion Congenital Heart Disease Congo Congo, Democratic Republic Conjunctivitis Connective Tissue Disorders Constipation Conventional Medicine Cornea and Corneal Disease Coronary Disease Costa Rica Côte d’Ivoire Craniology Crick, Francis Croatia Cross-Sectional Study Crossing Over Crossover Study Crude Mortality Rate Cryopreservation Cryosurgery Cuba Cyprus Cystic Fibrosis Cytogenetics Cytokine Czech Republic
D
Daily Reference Values (DRVs) Darwin, Charles Date Rape Da Vinci, Leonardo Deafness Death and Dying Death Rate Degenerative Nerve Diseases Dementia Demographic Transition Dengue Denmark Dental Health
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List of Articles
Department of Energy (DOE) Department of Health and Human Services (HHS) Depression Dermatitis Developmental Disabilities Diabetes Diabetes and Pregnancy Diabetes Type I (Juvenile Diabetes) Diabetes Type II Diabetic Eye Problems Diabetic Foot Diabetic Kidney Problems Diabetic Nerve Problems Diabetic Teeth and Gum Problems Diagnostic Imaging Diagnostic Tests Dialysis Diarrhea Diesel Exhaust Dieting Digestive Diseases (General) Diphtheria Disasters and Emergency Preparedness Disease and Poverty Disease Prevention Diverticulosis and Diverticulitis Dizygotic Twin Dizziness and Vertigo Djibouti DNA DNA Repair Dominica Dominican Republic Double-Blinded Study Doula Down Syndrome Drinking Water Drug Abuse Drug and Medical Device Safety Drug Enforcement Administration (DEA) Dyslexia Dysmorphology Dysphagia Dystonia
E
Ear Disorders Ear Infections East Timor Eating Disorders
Ecogenetics E. Coli Infections Ectoparasites Ecuador Edema Egypt Ehlers-Danlos Syndrome Ehrlich, Paul El Salvador Elbow Injuries and Disorders Elder Abuse Electromagnetic Fields Electrophysiology Emphysema Empiric Risk Employment Retirement Income Security Act (ERISA) Endemic Endocrine Diseases (General) Endocrinology Engram Environmental Health Environmental Medicine Environmental Protection Agency (EPA) Environmental Tobacco Smoke (ETS) Environmental Toxicology Enzyme-Linked Immunosorbent Assay (ELISA) Epidemic Epidemiologist Epidemiology Epigenetics Epilepsy Equatorial Guinea Eritrea Esophageal Cancer Esophagus Disorders Estonia Estrogen Replacement Therapy (ERT) Ethiopia European Association for Cancer Research (EACR) European Association for the Study of Obesity (EASO) European Food Safety Authority (EFSA) European Public Health Alliance (EPHA) European Public Health Association (EUPHA) Evidence-Based Medicine Exercise for Children Exercise for Seniors
Exercise Treadmill Test Exercise/Physical Fitness Extragonadal Germ Cell Tumor Eye Cancer Eye Care Eye Diseases (General)
F
Facial Injuries and Disorders Failure to Thrive Fainting Falls False Negative False Positive Farmer, Paul Federal Emergency Management Agency (FEMA) Fee-for-Service Female Circumcision Fetal Alcohol Syndrome Fever Fiji Filariasis/Elephantiasis Finland Flea Bites Fluoride Folic Acid Fondation Jean Dausset (CEPH) Food Allergy Food and Agriculture Organization of the United Nations (FAO) Food and Drug Administration (FDA) Food Contamination/Poisoning Food Safety Foodborne Diseases Foot Health Foot Injuries and Disorders Forensic Medicine Fractures Framingham Heart Study France Fraternal Twins Fredrickson, Donald Fungal Infections
G
Gabon Gage, Phineas Gallbladder and Bile Duct Diseases Gallbladder Cancer Galton, Sir Francis
List of Articles
Gambia Gastroenterologist Gastroenterology Gastroesophageal Reflux/Hiatal Hernia Gastrointestinal Bleeding Gaucher’s Disease Gay Gene Gel Electrophoresis Gene Array Analysis Gene Mapping Gene Pool Gene Silencing Gene Transfer Generic Drug Genes and Gene Therapy Genetic Brain Disorders Genetic Code Genetic Disorders Genetic Testing/Counseling Genetic Transformation Genetics Genital Herpes Genomic Imprinting Genomic Library Genotype Georgia (Country) Geriatrics Germany Germline Mutation Gerontology Ghana Giardia Infections Gibbon, John H., Jr. Glaucoma Global Health Council Global Health Ethics Glomerular Diseases Goiter Gonorrhea Gout and Pseudogout Greece Grenada Growth Disorders Guatemala Guillain-Barre Syndrome Guinea Guinea-Bissau Gum Disease Guyana Gynecologist Gynecology
H
Hair Diseases and Hair Loss Hair Dye Haiti Hand Injuries and Disorders Haploid Hardy, James D. Hardy-Weinberg law Head and Brain Injuries Head and Brain Malformations Head and Neck Cancer Head Lice Headache and Migraine Health Insurance Portability and Accountability Act (HIPAA) Health Maintenance Organization (HMO) Health Resources and Services Administration (HRSA) Healthcare, Africa Healthcare, Asia and Oceania Healthcare, Europe Healthcare, South America Healthcare, U.S. and Canada Hearing Problems in Children Heart Attack Heart Bypass Surgery Heart Diseases (General) Heart Diseases—Prevention Heart Transplantation Heart Valve Diseases Heat Index Hematologist Hematology Hemizygous Hemochromatosis Hemorrhagic Fever Hemorrhoids Hepatitis Hepatitis C Herbal Medicine Herbal Remedy Herbalism Herbalist Hernia Heroin Abuse Herpes Simplex Heterosexual Heterozygote High Blood Pressure High Risk Pregnancy Hip Injuries and Disorders
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Hispanic American Health Histology Hodgkin’s Lymphoma Homeopathy Homicide Homosexual Homozygote Honduras Hormone Replacement Therapy Hormones Hounsfield, Godfrey Household Poisons Hughlings Jackson, John Human Genome Organisation (HUGO) Hungary Huntington’s Disease Hydrocephalus Hygiene Hyperactivity Hypoglycemia Hypothermia
I
Iceland Immune System and Disorders Immunization/Vaccination Immunologist Immunology Immunosuppression Immunotherapy Impetigo Impotence In Situ In Vitro In Vivo Inbreeding Incidence Incontinence India Indian Health Service (IHS) Indonesia Indoor Air Pollution Infant and Newborn Care Infant and Toddler Development Infant and Toddler Health Infectious Diseases (General) Infertility Inflammatory Bowel Disease Influenza Inhalants Innate Immunity
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List of Articles
Inpatient Institute for Children’s Environmental Health (ICEH) Institute of Medicine (IOM) Institutional Review Board (IRB) Insurance Internal Medicine International Agency for Research on Cancer (IARC) International AIDS Vaccine Initiative (IAVI) International Center for Equal Healthcare Access (ICEHA) International Classification of Diseases (ICD) International Clinical Epidemiology Network (INCLEN) International Committee of the Red Cross (ICRC) International Council of AIDS Service Organizations (ICASO) International Epidemiological Association (IEA) International Federation of Red Cross and Red Crescent Societies (IFRC) International Genetic Epidemiology Society (IGES) International Health Ministries Office (IHMO) International Red Cross and Red Crescent Movement (RCRC) International Society for Environmental Epidemiology (ISEE) International Society for Pharmacoepidemiology (ISPE) International Society of Geographical and Epidemiological Ophthalmology (ISGEO) International Women’s Health Coalition (IWHC) Internist Intestinal Parasites Iran Iraq Ireland Iridology Irritable Bowel Syndrome Israel Italy
J
Jamaica
Japan Joint FAO/WHO Expert Committee on Food Additives (JECFA) Joint United Nations Programme on HIV/ AIDS (UNAIDS) Jordan Juvenile Rheumatoid Arthritis
K
Kazakhstan Kelman, Charles D. Kenya Kidney Cancer Kidney Diseases (General) Kidney Failure and Dialysis Kidney Stones Kidney Transplantation Kiribati Kirklin, John W. Klinefelter’s Syndrome Knee Injuries and Disorders Knockout Korea, North Korea, South Kübler-Ross, Elisabeth Kuwait Kwarshiorkor Kyrgyzstan
L
La Montagne, John Laboratory Tests Lactose Intolerance Laos Latvia Lauterbur, Paul C. Lead Poisoning Lean Body Mass Learning Disorders Lebanon Lederberg, Joshua Leg Injuries and Disorders Legionnaire’s Disease Leishmaniasis Leprosy Lesbian Lesotho Leukemia Leukodystrophies Lewis, Edward B. Liberia
Libya Liechtenstein Lithuania Liver Cancer Liver Diseases (General) Liver Transplantation Locus Longitudinal Study Lou Gehrig’s Disease Low Blood Pressure Low Vision Lung Cancer Lung Transplantation Lupus Luxembourg Lyme Disease Lymphatic Diseases
M
Macedonia (FYROM) Madagascar Maintenance Medication Malaria Malariologist Malariology Malawi Malaysia Maldives Male Genital Disorders Mali Malignant Mesothelioma Malta Managed Care Manic-Depressive Illness Mansfield, Peter Marasmus Marfan Syndrome Marijuana Abuse Marshall Islands Marx, Gertie F. Mauritania Mauritius McClintock, Barbara Me-Too Drug Mead, Margaret Measles Medicaid Medical College Admissions Test (MCAT) Medical Entomology Medical Geography
List of Articles
Medical Helminthology Medical Jurisprudence Medical Physics Medical Prefix Medical Research Council Medical Tourism MedicAlert Medicare Médicins Sans Frontières Medigap Policy MEDLINE Memory Meniere’s Disease Meningitis Menopause Menstruation and Premenstrual Syndrome Mental Health Mercury Meta-analysis Metabolic Disorders Methamphetamine Abuse Methylation Mexico Micronesia Microsurgery Midwife Mine Safety and Health Administration (MSHA) Mismatch Repair Missense Mutation Moldova Molds Monaco Mongolia Monozygotic Twin Morocco Mortality Moscati, St. Joseph Mosquito Bites Mouth Disorders Movement Disorders Mozambique Multiple Chemical Sensitivity Multiple Myeloma Multiple Sclerosis Mumps Muscle Disorders Muscular Dystrophy Myanmar
Myasthenia Gravis Myositis
N
Namibia National Asian Women’s Health Organization (NAWHO) National Association of Health Data Organizations (NAHDO) National Association of People with AIDS (NAPWA) National Breast Cancer Coalition (NBCC) National Cancer Institute (NCI) National Center for Chronic Disease Prevention and Health Promotion (NCCDPHP) National Center for Complementary and Alternative Medicine (NCCAM) National Center for Environmental Health (NCEH) National Center for Health Marketing (NCHM) National Center for Health Statistics (NCHS) National Center for HIV, STD, and TB Prevention (NCHSTP) National Center for Infectious Diseases (NCID) National Center for Injury Prevention and Control (NCIPC) National Center for Public Health Informatics (NCPHI) National Center on Birth Defects and Developmental Disabilities (NCBDDD) National Cholesterol Education Program (NCEP) National Coalition for Cancer Survivorship (NCCS) National Environmental Health Association (NEHA) National Eye Institute (NEI) National Heart, Lung, and Blood Institute (NHLBI) National Human Genome Research Institute (NHGRI) National Immunization Program (NIP) National Institute of Allergy and Infectious Diseases (NIAID) National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS)
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National Institute of Biomedical Imaging and Bioengineering (NIBIB) National Institute of Children’s Health (NICHD) National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) National Institute of Environmental Health Sciences (NIEHS) National Institute of Mental Health (NIMH) National Institute of Neurological Disorders and Stroke (NINDS) National Institute of Nursing Research (NINR) National Institute of Occupational Safety and Health (NIOSH) National Institute on Aging (NIA) National Institute on Alcohol Abuse and Alcoholism (NIAAA) National Institute on Deafness and Other Communication Disorders (NIDCD) National Institute on Drug Abuse (NIDA) National Institutes of Health (NIH) National Library of Medicine (NLM) National Mental Health Association (NMHA) National Network for Immunization Information (NNii) National Program of Cancer Registries (NPCR) National Women’s Health Organization (NWHO) Native American Health Naturopathy Nauru Nausea and Vomiting Neck Disorders and Injuries Neonatologist Neonatology Nepal Nephrologist Nephrology Netherlands Neural Tube Defects Neuroblastoma Neuroendocrinology Neurofibromatosis Neurologic Diseases (General) Neurologist
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List of Articles
Neurology Neuromuscular Disorders Neuropsychologist Neuroradiologist Neuroradiology Neuroscience Neuroscientist New Zealand Nicaragua Niger Nigeria Nirenberg, Marshall W. Noise Non-Hodgkin Lymphoma Nonsense Mutation North American Association for the Study of Obesity (NAASO) Norway Nose Disorders Nuclear Medicine Nurses’ Health Study Nutrition Nutritionist
O
Obesity Obsessive-Compulsive Disorder Obstetric Fistula Obstetrician/Gynecologist Obstetrics Occupational Health Occupational Injuries Occupational Medicine Occupational Safety and Health Administration (OSHA) Oman Onchocerciasis Oncologist Oncology Ophthalmologist Ophthalmology Optometrist Oral Cancer Oral Rehydration Therapy Oral Surgeon Organ Donation Organ Transplantation Orthomolecular Medicine Orthopedics Orthopedist Osler, Sir William
Osteoarthritis Osteogenesis Imperfecta Osteology Osteonecrosis Osteopathy Osteoporosis Otolaryngologist Otolaryngology Otology Outpatient Ovarian Cancer Over-the-Counter (OTC) Drug Ozone
P
Paget’s Disease of Bone Pain Pakistan Palau Palestine Panama Pan American Health Organization (PAHO) Pancreas Transplantation Pancreatic Cancer Pancreatic Diseases Papua New Guinea Paraguay Paralysis Parasitic Diseases Parathyroid Disorders Parkinson, James Parkinsonís Disease Passive Immunity Pasteur Institute Pasteur, Louis Pasteurization Pathologist Pathology Pathophysiology Pauling, Linus Pediatrics Penile Cancer Peptic Ulcer Perinatologist Perinatology Peripheral Nerve Disorders Peru Pesticides Pharmaceutical Industry (Worldwide) Pharmacist Pharmaco-epidemiology
Pharmacogenetics Pharmacogenomics Pharmacologist Pharmacology Pharmacopeia/Pharmacopoeia Pharmacy Phenotype Phenylketonuria Pheochromocytoma Philippines Phrenology Phylogenetics Physiatrist Physical Therapy Physiology Pituitary Disorders Pituitary Tumor Placebo Pneumonia Podiatrist Point Mutation Point of Service (POS) Poisoning Poland Polio and Post-Polio Syndrome Pollution Polycystic Kidney Disease Polymerase Chain Reaction (PCR) Polymorphism Polymyalgia Rheumatica Porphyria Portugal Postpartum Depression Prader-Willi Syndrome Preeclampsia Preferred Provider Organization (PPO) Pregnancy Pregnancy and Substance Abuse Pregnancy Loss Premature Babies Prenatal Care Prescription Drug Abuse Prevalence Preventive Care Primary Care Proctology Programmed Cell Death Prospective Study Prostate Cancer Prostate Diseases Psoriasis
List of Articles
Psychiatrist Psychiatry Psychoimmunology Psychologist Psychology Psychoneuroimmunology Psychooncology Psychotherapy Public Health Pulmonary Embolism Pulmonary Fibrosis Pulmonology
Q
Qatar
R
Rabies Radiation Exposure Radiologist Radiology Radon Ramsay Hunt, James Randomized Clinical Trial Rare Diseases Raynaud’s Disease Reflex Sympathetic Dystrophy Refractive Errors Refugee Health Rehabilitation Reproductive Health (General) Respiratory Diseases (General) Retinal Disorders Retrospective Study Rett Syndrome Reye Syndrome Rheumatic Heart Disease Rheumatoid Arthritis Rickets Rodbell, Martin Roentgen, Wilhelm Roentgenology Romania Rosacea Rubella Russia Rwanda
S
Sabin, Albert Sabin, Florence R.
Sachs, Jeffrey Safety (General) Saint Kitts and Nevis Saint Lucia Saint Vincent and the Grenadines Salivary Gland Disorders Salmonella Infections Samoa San Marino São Tomé and Principe Sarcoidosis Satellite DNA Saturated Fat Saudi Arabia Schizophrenia School Nutrition Association (SNA) Schweitzer, Albert Scleroderma Scoliosis SEER (Surveillance, Epidemiology, and End Results Program) Seizures Senegal Serbia and Montenegro Severe Acute Respiratory Syndrome (SARS) Sexually Transmitted Diseases Seychelles Shingles (Herpes Zoster) Shistosomiasis Shoulder Injuries and Disorders Sickle Cell Anemia Sierra Leone Singapore Sinusitis Sjogren’s Syndrome Skin Cancer Skin Diseases (General) Skin Pigmentation Disorders Sleep Disorders Slovakia Slovenia Small Intestine Cancer Smallpox Smokeless Tobacco Smoking Smoking and Pregnancy Smoking and Youth Smoking Cessation Snellen’s Chart Society for Healthcare Epidemiology of America (SHEA)
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Society for Nutrition Education (SNE) Society for Public Health Education (SOPHE) Soft Tissue Sarcoma Solomon Islands Somalia Somatic Mutation Soper, Fred L. South Africa Spain Speech and Communication Disorders Spider Bites Spina Bifida Spinal Cord Diseases Spinal Cord Injuries Spinal Muscular Atrophy Spinal Stenosis Spleen Diseases Sports Injuries Sprains and Strains Sri Lanka Staphylococcal Infections Stem Cells/Stem Cell Transplantation Stewart, Alice Stickler, Gunnar B. Stomach Cancer Stomach Disorders Streptococcal Infections Stress Stroke Substance Abuse and Mental Health Services Administration (SAMHSA) Sudan Sudden Infant Death Syndrome (SIDS) Suicide Sun Exposure Sun Protection Factor (SPF) Surgery Suriname Swaziland Sweden Switzerland Syria
T
Taiwan Tajikistan Tanner Stages Tanzania Taste and Smell Disorders Tay-Sachs Disease
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List of Articles
Teenage Pregnancy Telepathology Telesurgery Temporomandibular Joint Dysfunction Testicular Cancer Tetanus Thailand Third World Thomas, Lewis Thoracic Outlet Syndrome Thorn, George W. Throat Disorders Thymus Cancer Thyroid Cancer Thyroid Diseases Tick Bites Tinnitus Togo Tonga Tourette Syndrome Toxicology Trachoma Trans Fat Transient Ischemic Attack Travel Medicine Traveler’s Health Tremor Trinidad and Tobago Tropical Medicine Tuberculosis Tuberous Sclerosis Tumor Registry Tunisia Turkey
Turkmenistan Turner’s Syndrome Tuvalu Typhoid
U
Uganda Ukraine Ulcers Ultraviolet Radiation United Arab Emirates United Kingdom United Nations Children’s Fund (UNICEF) United Network for Organ Sharing (UNOS) United States Medical Licensing Examination (USMLE) United States Pharmacopeia and National Formulary (USP-NF) United States Public Health Service United States Statistics Universal Donor Unsaturated Fat Urinary Tract Infections Urological Surgeon Urologist Uruguay Usher Syndrome Uterine Cancer Uterine Diseases Uzbekistan
V
Vaginal Cancer
Vaginal Diseases Vanuatu Varco, Richard L. Vasculitis Venezuela Vietnam Viral Infections Virology Vitamin A Deficiency Vitamin and Mineral Supplements Vitiligo Voice Disorders Voluntary Euthanasia Society (VES) Vulvar Cancer
W
Warshaw, Joseph Watson, James West Nile Virus Western Sahara Whooping Cough Wilkins, Lawson Wilson’s Disease Women’s Health (General) World Health Organization (WHO) Wrist/Arm Injuries and Disorders
Y
Yemen
Z
Zambia Zimbabwe Zoll, Paul M.
List of Contributors Acharya, Utkarsh Ohio University College of Osteopathic Medicine Aenlle, Lisa Michigan State University College of Human Medicine Ajayi, Toyin King’s College, London School of Medicine Ahmad, Aisha St. Joseph Mercy of Macomb Akter, Farhana King’s College, London Alexander, Shelley L. University of Missouri-Kansas City School of Medicine
Bergman, Hagit University of Louisville
Chen, Stephen University of Toronto
Bhatraju, Pavan University of Louisville
Chute, Laura Autumn Independent Scholar
Boslaugh, Sarah E. BJC HealthCare
Clerkin, Cathleen University of California, Berkeley
Boyle, Helen Independent Scholar
Clerkin, Paul J. Sacramento City College
Boyle, Peter Independent Scholar
Corfield, Justin Geelong Grammar School, Australia
Brady, Mark Brown Medical School
Cox, W. Joshua Kansas City University of Medicine and Biosciences
Breitbart, Ross E. Philadelphia College of Osteopathic Medicine
Ali, Ather Yale University
Bumpass, David B. University of Virginia
Ali, S. Harris York University, Toronto
Burns, Melody University of Missouri-Kansas City School of Medicine
Ament, Jared Daniel Harvard Medical School Harvard School of Public Health
Currier, Connie Michigan State University Curry, Christine Independent Scholar Cymet, Tyler Childs Johns Hopkins School of Medicine
Busfield, Joan University of Essex
Darda, Saba Independent Scholar
Barnes, Regan Kansas City University
Chandra, Amit New York Hospital, Queens
Darido, Elias Independent Scholar
Basseri, Robert J. University of Southern California, Los Angeles
Chang, Cindy Cold Spring Harbor Laboratory SUNY Stony Brook
Dasari, Chanukya R. University of Missouri-Kansas City School of Medicine
Bedi, Manpreet University of Missouri-Kansas City
Chaudhari, Bimal P. Boston University
Dasco, Matthew Brown University
Benzekri, Noelle A. UCLA School of Medicine
Chaudhury, Moushumi Boston University
David, Annette M. Health Partners, L.L.C.
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De Maio, Fernando Simon Fraser University
Gearhart, Shannon Indiana University School of Medicine
de Sanjosé, Silvia Catalan Institute of Oncology, Barcelona, Spain
Ghanbari, Hamid Independent Scholar
Desai, Gautam J. Kansas City University of Medicine and Biosciences Desai, Komal Bharat Independent Scholar Donkor, Martha Edinboro University Dowling, Dennis J. Independent Scholar Drazin, Doniel Albany Medical College Draeger, Nicholas J. Kansas City University of Medicine and Biosciences Dude, Annie University of Chicago Dunbar, Brett D. Independent Scholar Ezra, Navid David Geffen School of Medicine Farooq, Sidrah Independent Scholar Fatima, Quratulain Independent Scholar Fernandez Diaz, Natalia Independent Scholar Fitch, Erin Oregon Health and Science University
Gharipour, Mohammad Independent Scholar Gladwin, Rahul University of Health Sciences, Antigua Glaros, Alan George Kansas City University of Medicine and Biosciences Glaser, Kelli Independent Scholar Gokoffski, Kimberly University of California, Irvine Goldkamp, Jennifer University of Missouri, Kansas City Goldstein, Bradley E. Lake Erie College of Osteopathic Medicine Gowda, Charitha Duke University School of Medicine Grant, Jonelle S. University of North Carolina Grant, William B. Sunlight, Nutrition, and Health Research Center Guffey, Megan K. Independent Scholar Gupta, Nakul Ross University School of Medicine Gurbani, Barkha N. UCLA School of Medicine
Hunt, Tracey A. Kansas City University of Medicine and Biosciences Husseini, Abdullatif Birzeit University, Palestine Ingram, Stephanie F. University of South Florida College of Medicine Jain, Sachin Rush University Medical Center Janes, Matthew University of California, Irvine Janneck, Laura Case Western Reserve University School of Medicine Jeshmaridian, Samvel Sergei American Psychological Association Joshi, Priya P. Chicago Medical School Khan, Karim Independent Scholar Karty, Ann M. Kansas City University of Medicine and Biosciences Kaur, Yasmin St. Matthew’s University Kaushik, Anjan P. University of Virginia Keller, Thomas Christian University of Virginia Kennedy, Justina University of Louisville
Gurbani, Mala University of Southern California
Khan, Omar A. University of Vermont College of Medicine
Hadland, Scott Washington University School of Medicine
Khanderia, Shamoli Private Practice Physician
Foote, Mary University of Arizona
Hamilton, William J. Arizona State University
Kim, Daniel Harvard School of Public Health
Franco-Paredes, Carlos Emory University
Haque, Omar Sultan Harvard Medical School
Kiem, JoAnn Tijn Kon Independent Scholar
Frye, Stacy A. Michigan State University
Hartmann, Daniel University of Heidelberg, Germany
Kim, Lindsay Emory University School of Medicine
Fujioka, Kimberly University of California, Berkeley
Hellawell, Jennifer L. Cornell University School of Medicine
Gagne, Joshua J. Jefferson Medical College
Hissett, Jennifer University of Colorado Health Sciences Center
Kolo, George Kansas City University of Medicine and Biosciences
Garcia, Megan University of Missouri-Kansas City
Hoh, Josephine Yale University Department of Epidemiology and Public Health
Fleg, Anthony UNC Chapel Hill Schools of Medicine and Public Health
Garner, Angela J. University of Missouri-Kansas City School of Medicine
Hohman, Donald W., Jr. St. George’s University
Kulczycki, Andrzej University of Alabama, Birmingham La Flair, Lareina Nadine Harvard Medical School Lathorn, Heather Independent Scholar
List of Contributors
Le, Mai Nhung San Francisco State University
Meiners, Melissa University of Missouri, Kansas City School ‘ of Medicine
Patel, Sangeeta University of Illinois at Chicago College of Medicine
Menon, Priya Johannesburg General Hospital
Patel, Shalu S. University of Michigan
Mexia, Ricardo Independent Scholar
Pilitsis, Julie Rush University Medical Center
Michaud, Lyn Independent Scholar
Pizzorno, Joseph E. Bastyr University
Michon, Heather K. Independent Scholar
Pollard, Vincent Kelly University of Hawaii at Manoa
Liu, Constance W. Case Western Reserve University
Miller, DeMond Shondell Rowan University
Lozada, Jose S. Case Western Reserve University
Monaco, Thiago University of Sâo Paulo Medical School, Brazil
Potru, Rachana Michigan State University College of Human Medicine
Lee, Darrin J. University of California, Irvine Levin, Elizabeth Laurentian University Lim, Joanne University of Southern California List, Justin M. Stritch School of Medicine, Loyola University Chicago
Lunardini, David J. University of Virginia Ly, E. John Brown University Medical School Ma, Shen-Ying Richard University of Virginia Madjar, Ingrid Y. Kansas City University of Medicine and Biosciences College of Osteopathic Medicine Malik, Rizwan Asif Independent Scholar Malouin, Rebecca A. Michigan State University Mamelian, Kristen University of Missouri, Kansas City Manganaro, Christine L. University of Minnesota Martinez, Celina Johns Hopkins University School of Medicine Masood, Quratulain Independent Scholar May, Linda E. Kansas City University of Medicine and Biosciences Mayne, Susan T. Yale University McClain, Rance Kansas City University of Medicine and Biosciences McRae, Mary Peace Kansas City University of Medicine and Biosciences Mehta, Amee Independent Scholar Mehta, Jinal University of Missouri
Prono, Luca Independent Scholar
Morris, Shaun K. Independent Scholar
Purdy, Elizabeth Independent Scholar
Nandi, Deipanjan Duke University School of Medicine
Quinn, John University of Illinois at Chicago
Neu, Denese M. HHS Planning & Consulting, Inc.
Rad, Seyed Ali Mohammadi Michigan Radiological Society
Neff, Duane R. Brandeis University
Raminani, Sudha R. The Fenway Institute
Nguyen, Claire K. Johns Hopkins Bloomberg School of Public Health
Ran, Maosheng University of Guam
Nijhawan, Rajiv I. Independent Scholar Noguchi, Lisa Pittsburgh Medical Center Novogradec, Ann York University, Toronto Ogden, Richard K. Kansas City University of Medicine and Biosciences Padula, Alessandra Università degli Studi, L’Aquila, Italy
Rattan, Rishi University of Illinois–Chicago Richards, Misty Charissa Albany Medical College Roberto, Christina Yale University Robinson, Elliot P. University of Virginia Rodriguez-Morales, Alfonso J. Universidad de Los Andes, Venezuela Rowland, Amy John Jay College of Criminal Justice
Pakes, Barry University of Toronto
Sacks, Emma Columbia University
Palmatier, Jason Independent Scholar
Sagert, Kelly Boyer Independent Scholar
Panjabi, Rajesh University of North Carolina, Chapel Hill Johns Hopkins School of Public Health
Samad, Ahmed S. Hoffmann-La Roche Inc.
Patel, Ashwinkumar Wharton School of the University of Pennsylvania Patel, Pinaki N. Kansas City University of Medicine and Biosciences College of Osteopathic Medicine
Samartzis, Dino Harvard University Sathe, Neha New York University Saunders, Paul Richard Canadian College of Naturopathic Medicine
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List of Contributors
Scheller, Ericka L. Kansas City University of Medicine and Biosciences Schlaefer, Katherine Camino al Cambio Sebley, Caroline Kansas City University of Medicine Sedney, Cara West Virginia University School of Medicine Seetharam, Anil Washington University in St. Louis Sehgal, Akta University of Missouri–Kansas City School of Medicine Shealy, C. Norman Independent Scholar Shekhawat, Nakul Vanderbilt University Shen, Francis H. University of Virginia Shenderov, Kevin New York University Shimizu, Ikue Brown University Medical School Sinclair, Amber University of Georgia Skaouris, Afrodite Northeastern Illinois University Smith, Erin Kansas City University of Medicine Smith, Matthew Jordan Florida State University Soper, Fred L. Independent Scholar Stansbeary, Jeremy John Oklahoma State University Stevenson, Bernadette Mietus University of North Carolina Stickler, Gunnar B. Independent Scholar Strain, Ryan University of Missouri-Kansas City School of Medicine Sturm, Jacquelyn Independent Scholar
Sullivan, Timothy Georgetown University Sundet, Sarah Independent Scholar Tabin, Geoffrey University of Utah School of Medicine Tan, Jonathan SUNY Stony Brook School of Medicine Tavassoly, Iman Mazandaran University of Medical Sciences, Iran Taylor, John M. University of Alberta Tella, Swathi Independent Scholar Taarea, Roberto Independent Scholar Tarigopala, Sweta Independent Scholar Tavassoly, Omid Tarbiat Modares University Terzioglu, Aysecan City University of New York Tatevossian, Tiffany David Geffen School of Medicine at UCLA Than, Khoi D. Johns Hopkins University School of Medicine Thorn, George W. Independent Scholar Tuddenham, Susan Independent Scholar Urajnik, Diana University of Toronto Usera, Phillip Cresswell The Medical School for International Health, Israel Van Opstal, Elizabeth Michigan State University Varco, Richard L. Independent Scholar Vassy, Jason Washington University in St. Louis
Sturzenegger, Amber Kansas City University
Vegosen, Leora Johns Hopkins Bloomberg School of Public Health
Subbarayan, Rishi North Eastern Ohio Universities College of Medicine
Villanueva, Tiago Centro Hospitalar de Lisboa-zona Central, Portugal
Walsh, John Shinawatra University, Thailand Waskey, Andrew J. Dalton State College Watcha, Daena Stanford University Webster, Danielle University of Missouri–Kansas City School of Medicine Webster, Noah J. Case Western Reserve University Wentzell, Emily University of Michigan Willsie, Debra A. University of Missouri–Kansas City Willsie, Sandra Kansas City University of Medicine and Biosciences Winn, Jessica Independent Scholar Winograd, Claudia University of Illinois Wirtz, Andrea Johns Hopkins University School of Public Health Wolinski, Melissa K. Michigan State University Wynne, Ben Gainesville State College Yaman, Aylin Antalya State Hospital Yaman, Hakan Akdeniz University Yeh, James S. Boston University School of Medicine Yelin, Joel C. Rowan University Yoo, Grace San Francisco State University Younger, Jarred Stanford University School of Medicine Yeung, Michael Independent Scholar Zheng, Tongzhang Yale University School of Medicine Zincavage, Rebekah M. Brandeis University
Chronology
8000–10000 b.c.e.: Evidence that healers attended to trauma, set broken bones, assisted at childbirth, and conducted healing rituals. 3100 b.c.e.: First report of use of Chinese herb Ma Huang, also known as ephedrine. 1350 b.c.e.: Earliest recorded epidemic of smallpox. Smallpox spread rapidly throughout the populated world including Egypt, Arabia, Greece and in the second century c.e. had spread into central Europe. 300 b.c.e.: An essential part of Greek thinking is the early idea of balance of the four basic elements: fire, water, air, and earth. To each of these elements there was a bodily humor (blood, black bile, yellow bile, and phlegm). Illness was ascribed to their imbalance. 0 c.e.: At the beginning of the Christian era, the world population is probably about 250 million, a figure that did not change appreciably for a thousand years. 335: Emperor Constantine decrees that infirmaries (early hospitals) must be built in Rome. 700s–800s: First asylums (mental hospitals) built.
1348: Venice develops a 40-day detention period (quarantine) for all incoming vessels as Venetians believed the plague was introduced via ships. Genoa, Marseilles, and other major ports adopted the quarantine. 1400s: Pope Sixtus IV permits autopsies at Bolonga and Padua medical schools. 1530: Contagion theory of disease is articulated by Renaissance physician and scholar Girolamo Fracastoro. In 1530, he also coined the name for syphilis. 1610: First cesarean section is performed on a living woman. 1624: Typhoid fever is described. Typhoid fever is an infectious disease caused by the bacterium salmonella typhi, which multiplies in the bloodstream and gets excreted out via the digestive tract. Late 1640s: Yellow fever epidemic is recorded. Yellow fever is caused by the yellow fever virus, which is carried by mosquitoes. It is now endemic in 33 countries in Africa and 11 countries in South America. 1665: Scientific journals begin publication. The French Journal des sçavans and the English Philosophical xxxv
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Transactions of the Royal Society first began systematically publishing research results.
terial disease that primarily affects the nasal passages, throat, and lungs.
1700s: Bristle toothbrushes are introduced. It was during World War II that the concept of brushing teeth really caught on in the United States, in part due to the fact that it was part of American soldiers’ regular daily duty to clean their teeth.
1820s: Tubal sterilization is proposed.
1747: First clinical trial, of citrus fruit for treating scurvy, is conducted. Scurvy is a deficiency disease that results from lack of vitamin C, which is required for correct collagen synthesis in humans. 1750: Word “antiseptic” is first used. Antiseptics are antimicrobial substances that are applied to living tissue/skin to reduce the possibility of infection, sepsis, or putrefaction. 1751: Giovanni Morgagni’s On the Seats and Causes of Disease as Investigated by Anatomy, containing life and postmortem observations on 700 patients is published. 1785: First clinical description of chicken pox. Chickenpox is caused by the varicella:zoster virus (VZV), also known as human herpes virus 3 (HHV-3), one of the eight herpes viruses known to affect humans. 1785: Placebo is described. 1796: Edward Jenner introduces a modified technique of variolation by using cowpox material. Mass inoculation using cowpox material (called vaccination) was introduced extensively in Britain first and then in all of Europe and other parts of the colonial world. 1802: Health and Morals of Apprentices Act legislated to control abuses of the Industrial Revolution in England. It limits the work of children in textile factories to 12 hours per day, but setting no lower age limit for employment. 1803: Morphine is isolated from opium. 1818: Cholera spread to Southeast Asia, China, Japan, East Africa, the eastern Mediterranean (Syria and Palestine), and southern Russia. 1820s: First description of diphtheria. Diphtheria is a very contagious and potentially life-threatening bac-
1830: Widespread efforts to alleviate many unhealthful conditions begins in England. 1831–1833: The first cholera pandemic to strike England and western Europe takes thousands of lives and quickly spreads to North America via shipping. 1839: “Cell Theory” is introduced. 1839: Vulcanization is discovered, making rubber condoms possible. 1842: Ether is introduced as the first practical anesthetic. Anesthesia has traditionally meant the condition of having the perception of pain and other sensations blocked. 1842: Edwin Chadwick introduced his Report on an Inquiry into the Sanitary Condition of the Labouring Population of Great Britain, a document fundamental in the development of modern public health. 1849: John Snow publishes On the Mode of Communication of Cholera, a work expanded and augmented in 1854 which would become one of the great classics of epidemiological reasoning. 1859: Louis Pasteur suggests that fermentation is caused by living organisms, and that human disease is caused by a similar process. 1851: The First International Sanitary Conference, organized by 12 European nations in Paris, tries to work out the solutions to the “Defense of Europe.” This was the first attempt to reach a consensus on drafting international quarantine regulations. 1854: Italian researcher Filippo Pacini discovers and names the cholera vibrio in the stools and intestine of cholera patients and cited it as the cause of the illness. 1855: Cell division is first described. Cell division is the biological basis of life and enables sexually reproducing organisms to develop from the one-celled zygote.
1859: Charles Darwin’s The Origin of Species is published. Darwin summarized his theory of evolution through natural selection. 1863: International Committee of the Red Cross is founded. The Red Cross was the first nongovernmental organization (NGO), founded by a Swiss national inspired by the terrible suffering of soldiers. 1868: First employee and employer-sponsored health insurance program is established. 1870: French physiologist Paul Bert publishes Barometric Pressure, a summary of his pioneering studies on the effects of high and low pressure on human physiology. 1875: Union of sperm and egg nuclei during fertilization is observed. 1879: Germ theory is introduced. The germ theory of disease, also called the pathogenic theory of medicine, is a theory that proposes that microorganisms are the cause of many diseases. 1890: John Simon, the pioneer of English state medicine, surveys progress in public health during the past two centuries in his English Sanitary Institutions. 1880: A Panama Canal building project is started by the French. After 8 years and almost 20,000 deaths from malaria and yellow fever, the French abandoned their effort. 1881: Robert Koch discovers how to grow bacteria in culture, an advance for testing antibiotics. 1889: Baltimore surgeon William Halsted suggests that his nurse wears rubber gloves during surgery and realizes effect on antisepsis. 1890: Antibodies, called antitoxins at the time, are discovered. 1890: Cause of dental caries is discovered. Dental caries, also described as tooth decay, damages the structures of teeth. 1983: French physician, Jacques Bertillon, introduces the Bertillon Classification of Causes of Death at the
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International Statistical Institute in Chicago. A number of countries adopted Dr. Bertillon’s system . 1896: Radium is discovered. Radium is intensely radioactive and is used in medicine to produce radon gas, which in turn is used as a cancer treatment. 1900: Blood types are discovered. The classification of blood is based on the presence or absence of inherited antigenic substances on red blood cells. 1903: Several nations sign International Sanitary Agreement to prevent the spread of yellow fever, cholera, and bubonic plague. 1904: An Edinburgh doctor reports that alcohol, lead, and morphine given to a pregnant woman can harm a developing fetus. 1906: Word “allergy” is coined. Allergies are the immune system’s incorrect response to a foreign substance. 1907: The French government hosts the first international health office, called L’Office International d’Hygeine Publique (OIHP) in 1907 in Paris. OIHP was the first truly international health agency to monitor and report health outbreaks 1909: Rockefeller Foundation begins with some 72,000 shares of stock in Standard Oil of New Jersey. Its purpose was to “Promote the well-being and to advance civilization of the peoples of the United States ... ”. 1910: First gene is mapped to a chromosome. Today, scientists have identified more than 1 million genetic variations that relate to disease risk or drug responses, and predict whether a medicine might be effective, ineffective, or toxic in certain individuals. 1911: Measles proven to be caused by a virus. Measles is a highly contagious infectious disease characterized by fever, cough, conjunctivitis, and a distinctive spreading rash. 1912: Word “vitamins” is coined to describe nutrients, deficiencies of which cause disease. 1913: James B. Waton’s manifesto on behaviorism is published.
xxxviii Chronology
1915: First-known medical transport takes place as the Serbian Army retreats from Albania. 1919: Rickets are attributed to dietary deficiency, shown as preventable and curable with cod liver oil. 1920s: George Papanicolaou introduces the Pap smear test for screening cervical cancer and uterine cancer. 1921: Discovery of insulin to treat diabetes. The disease was reported as an uncommon condition in the developing world at the time.
1946: The International Monetary Fund is developed representing 182 member countries who promote monetary cooperation, economic growth, and temporary financial assistance in other to help balance payment adjustments through surveillance and technical assistance. 1946: United Nations Children’s Fund (UNICEF) is established.
1922: Cures of cancer with radiotherapy reported.
1947: Nuremberg Code is promulgated. The Nuremberg Code is a set of principles for human experimentation set as a result of the Nuremberg trials at the end of World War II.
1923: League of Nations Health Organization forms. A series of basic clinical field research studies on medicine and public health are undertaken.
1948: World Health Organization (WHO) is founded. The WHO, the primary global health organization in the world.
1924: Last outbreak of bubonic plague in the United States begins. Last reported U.S. cases of human-tohuman plague transmission occurs. 1927: Pregnancy test is invented.
1949: Framingham Heart Study is launched. The Framingham Heart Study is a cardiovascular study based in Framingham, Massachusetts. The study began with 5,209 adult subjects from Framingham, and is on its third generation of participants today.
1928: First antibiotic drug, penicillin, is discovered by Scottish scientist Sir Alexander Fleming.
1950: Studies conclude there is strong evidence that smoking cigarettes causes lung cancer.
1934: Mumps shown to be caused by virus. Mumps is a viral infection that primarily affects the parotid glands.
1950: Chinese government announces it wants to reconcile traditional Chinese medicine and Western medicine into a single system.
1936: Cystic fibrosis (CF) is described. Cystic fibrosis is an inherited disease that affects breathing and digestion. 1937: First U.S. blood bank is established in Chicago. 1937: The West Nile Virus is first isolated in a human in Uganda. West Nile Virus is spread by vector transmission where a living organism passes the virus to the human. 1940: One of four viruses that cause dengue fever is discovered. 1945: First water fluoridation program is launched in Michigan. 1946: Communicable Disease Center, which developed into the Centers for Disease Control and Prevention, is founded.
1953: Structure of DNA is discovered. Watson and Crick published their results on DNA structure in the April 25, 1953 issue of Nature. The model of the DNA as a double helix revolutionized research. 1954: Field trials of polio vaccine begin. Polio is an acute viral infectious disease which is spread from person to person via the fecal–oral route. 1958: WHO recommends launching the Eradication of Smallpox Program at the World Health Assembly. 1958: The International Standards for Drinking Water are published. In this instance the term “standards” was used to be applied to the suggested criteria of water quality. 1958: Cardiopulmonary resuscitation (CPR) is discovered. It is an emergency first aid procedure for a
victim of cardiac arrest. It is part of the chain of survival, which includes early access (to emergency medical services), early CPR, early defibrillation, and early advanced care. 1960: Birth control pill is introduced. The Federal Drug Administration (FDA) approved a drug containing artificial progesterone and estrogen as a contraceptive. 1960: The Center for Health and Population Research is founded by the United States and Pakistan governments to study the epidemiology, prevention, and treatment of cholera. 1962: Rubella virus is isolated. Rubella is a mild disease with signs and symptoms of low-grade fever, swollen lymph nodes in the neck, and a pink rash of many tiny raised bumps on the face, trunk, and extremities. The greatest health concern with rubella is to women in the first trimester of pregnancy and may result in spontaneous abortion. 1962: Rabies virus is observed. Rabies is a serious viral disease that affects the central nervous system. Typically, rabies spreads by way of the saliva of infected animals. 1963: Activities of Daily Living (ADLs) scale first published. ADLs refer to the regular, everyday tasks that are necessary for independent living and self-care. 1964: U.S. Public Health Service launches its first antismoking campaign. 1965: Medicare is signed into law on July 30, 1965 by President Lyndon B. Johnson as an amendment to Social Security legislation. 1965: The International Agency for Research on Cancer (IARC) is established to conduct research on environmental biology and cancer. 1967: First successful heart transplant is completed. 1970: Environmental Protection Agency (EPA) is founded. The EPA is an agency of the federal government of the United States charged with protecting human health and with safeguarding the natural environment. 1971: Australia passes its first law requiring seat-belt use.
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1971: Herb used in ancient Chinese medicine to treat malaria, quinghaosu, is proven to be effective. 1971: Family Health International is founded. It is among the largest and most established nonprofit organizations active in international public health. 1972: Clean Water Act is passed. 1972: WHO launches a special program of research, promotion, and development on human reproduction to meet the needs of developing countries. 1972: Medicaid is instituted in the United States as health insurance for the poor. 1973: Surveillance, Epidemiology, and End Results Program (SEER) is established by the National Cancer Institute (NCI) of the U.S. Department of Health and Human Services to collect and study cancer incidence and survival data in the United States. 1973: Supreme Court passes Roe v. Wade, a law legalizing first-term abortion and leaving the regulation of second- and third-term abortions in states’ hands. 1975: WHO, together with the United Nations Development Program (UNDP) and the World Bank, establishes a special program for research and training in tropical diseases. 1975: First case of e. Coli 0157:H7 is reported. Escherichia coli are bacteria of which the virulent strains can cause significant gastrointestinal morbidity and mortality. E. coli O157:H7’s virulence stems from its ability to produce several toxins. 1975: First hybridoma, cell that produces monoclonal antibodies is created. 1975: United Nations Children’s Fund (UNICEF) supports piloting and launch of Integrated Child Development services. Today, this program reaches out to 4.8 million expectant and nursing mothers and 30 million children under six years of age in India per year. 1976: Existence of oncogenes reported by Dr. G. Steve Martin of the University of California, Berkeley. An oncogene is a modified gene, or a set of nucleotides that codes for a protein, that increases the malignancy of a tumor cell.
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Chronology
1976: First mass flu (influenza) vaccine program is launched. Each year, the influenza virus changes and different strains become dominant. Due to the high mutability of the virus, a particular vaccine formulation created in labs usually only works for about a year. 1978: First test-tube baby born. 1978: Hepatitis A is grown in culture. Hepatitis A is spread through feces. One can get infected through close contact with an infected person (e.g., changing a diaper or having sexual contact). One also can get infected by eating contaminated food or drinking contaminated water. 1979: Smallpox is eradicated. It was a highly infectious viral disease spread by respiratory discharge, killing 25–30 percent of unvaccinated patients. The virus still exists in at least two laboratories in the world (the CDC and a research institute in Moscow) so that a vaccine can be made in case there is another outbreak. 1980: Congress passes Superfund Act, formerly known as the Comprehensive Environmental Response, Compensation, and Liability Act. 1981: First description of acquired immunodeficiency syndrome (AIDS) is published in Morbidity and Mortality Weekly. 1982: A hepatitis B vaccine is available. Infection due to hepatitis B virus became a global health problem in the late 1980s.
1985: FDA approves the first enzyme linked immunosorbent assay (ELISA) test kit to screen for antibodies to HIV. 1986: The largest-ever radiation accident involving a nuclear reactor occurs at the Chernobyl nuclear power plant in Ukraine. Radioactive contamination spread over large areas of Belarus, the Russian Federation, and Ukraine. 1986: U.S. Surgeon General C. Everett Koop calls for AIDS education for children of all ages, saying that “We can no longer afford to sidestep frank, open discussions about sexual practices, homosexual or heterosexual.” 1987: CDC recommends universal precautions for preventing the spread of infection. 1988: The World Health Assembly resolves to eradicate polio by the year 2000. 1988: Human Genome Project is launched. An international research effort to sequence and map all of the genes—together known as the genome—of members of the human species, Homo sapiens. Completed in April 2003. 1988: The use of radiation sources in medical and other applications is widespread throughout the world. 1988: Condom use is shown to be effective in preventing sexual transmission of HIV. 1990s: At least 11 countries are experimenting with biological weaponry.
1982: The CDC changes the name of the illness called GRID or “gay cancer” to AIDS.
1990: First public health recommendations urging women to have regular mammograms.
1983: Human immunodeficiency virus (HIV) is discovered. HIV emerged as an explosive pandemic by the mid-1980s. As soon as the main modes of transmission of AIDS were identified, a global program on AIDS was initiated in the mid-1980s by WHO.
1990: Around 1 billion people do not have access to a safe water supply, while over 1.7 billion are without adequate sanitation.
1983: A dermatologist from India begins to identify skin lesions from arsenic poisoning on his patients from the Eastern Indian State of West Bengal which shares some aquifers with Bangladesh. 1984: First needle exchange program is introduced in Amsterdam.
1990: American AIDS deaths pass the 100,000 mark —nearly twice the number of Americans who died in the Vietnam War. 1992: National Institutes of Health (NIH) forms Office of Alternative Medicine. 1993: Tuberculosis emerges as a globally dangerous infection.
1994: BRCA2, second breast cancer gene, is located and identified. 1994: Obesity in the United States increases to 22.5 percent from 14.5 percent in 1976. 1995: Hepatitis A vaccine is introduced. Hepatitis A is an acute infectious liver disease caused by the hepatovirus hepatitis A virus. The vaccine will prevent infection from hepatitis A for approximately 15–30 years. 1995: Protease inhibitors (PIs) are introduced. PIs are a class of medication used to treat or prevent infection by viruses, including HIV and hepatitis C. 1997: Scientists clone sheep. 1997: Highly pathogenic avian influenza outbreak in Hong Kong causes 18 cases. Extensive studies of the human cases determined that direct contact with diseased poultry was the source of infection. 1997: China’s immunization program covers more than 95 percent of children. 1997: The first human trials of an AIDS vaccine begin with 5,000 volunteers from across the nation. 1998: WHO initiates a global program called Roll Back Malaria. Malaria remains a threat in about 100 countries, most of which are located in the tropics and subtropics. 1998: Healthy People 2010 is released. It is a nationwide health promotion and disease prevention plan that is composed of 467 specific objectives, 28 goals, and two overarching goals to be achieved by the year 2010. 1998: 134 million children are immunized against polio in a single day in India. 1998: Human embryonic stem cells are cultured. Because of their plasticity and potentially unlimited capacity for self-renewal, Embryonic stem cell therapies have been proposed for regenerative medicine and tissue replacement after injury or disease. 1999: Washington University in St. Louis researchers show that treating rats’ injured spinal cords with immature nerve cells grown from stem cells helps re-
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store some function. The research suggests that this technique could one day be used in human spinal cord injury treatment. 2000: EPA signs agreement with 26 other nations to bring down the emissions of several chemicals to reduce smog, acid rain, and other types of environmental damage. 2000: United Nations Millennium Declaration is signed. The Millennium Development Goals are eight goals that 191 United Nations member states have agreed to try to achieve by the year 2015. 2002: The first human cases of SARS are identified. SARS originally involved a zoonotic transmission in which the novel coronavirus crossed over from an animal species to humans, then adapting itself so that it could be transmitted between human hosts. 2002: The Global Fund is created. AIDS, tuberculosis, and malaria are preventable diseases that can be treated effectively. Relative to high-income countries, the burden of these diseases is 30 times greater in developing countries, resulting in economic loss, social disintegration, and political instability. The Fund was created to respond to this challenge. 2004: Road traffic injuries are a deadly scourge, taking the lives of 1.2 million men, women and children around the world each year. Hundreds of thousands more are injured on roads, some of whom become permanently disabled. The vast majority of these occur in developing countries, among pedestrians, cyclists, motorcyclists, and users of public transport, many of whom would never be able to afford a private motor vehicle. 2005: Save the Children, a U.S.-based independent global humanitarian organization, released its annual Mothers’ Index that ranks the best and worst places to be a mother and a child. The index, highlighted in the organization’s State of the World’s Mothers 2005 report, ranks the status of mothers and children in 110 countries based on ten indicators pertaining to health and education. The index reveals that where mothers survive and thrive, children survive and thrive. Scandinavian countries sweep the top rankings of the best places to be a mother, while countries in sub-Saharan Africa dominate the bottom tier. The United States ranks in 11th place.
2007: Former United Nations chief Kofi Annan warns that climate change is likely to be the most urgent humanitarian challenge in the future, highlighting some one million people hit by recent flooding in Africa. Risks to international public health from floods, heat waves, and droughts arising from climate change are becoming the focus of global health organizations and
officials around the world. A range of health problems is expected to accompany rising temperatures worldwide, especially in developing countries, according to Climate Change 2007: Impacts, Adaptation and Vulnerability. Briseis Kilfoy Yale University
A Abortion An abortion is the termination of a pregnancy. It may be spontaneous (also called miscarriage) or induced. About one in five pregnancies ends in spontaneous abortion, typically at an early stage and due to chromosomal abnormality of the conceptus. Such spontaneous embryonic wastage often causes grief for the pregnant woman and is ignored by communities. In contrast, induced abortion (hereafter, abortion) may bring relief from an unwanted pregnancy and is often condemned by societies. Abortion is widely resorted to for birth control; most of the world’s women are likely to have had one or more abortions by the time they complete their childbearing years. Historically, women who underwent abortions risked their personal health and social standing. This situation changed slowly in the 20th century as abortion procedures became much safer and as efforts to legalize abortion gained momentum. Abortion is nowadays a minimum-risk procedure when it is performed by a trained professional in a hygienic setting. But in many countries where it is illegal, and in some where it is legal, unsafe abortion is a common cause of maternal mortality and its complications contribute to serious sequelae for women’s health such as infertility. Despite these realities, abortion
is often stigmatized within medicine and is deeply controversial in some societies and polities. Incidence of Abortion Worldwide, an estimated 46 million pregnancies end in induced abortions each year, nearly half of them in unsafe circumstances. Given that some 210 million pregnancies occur annually, this implies that about 22 percent of all pregnancies worldwide are aborted. However, the incidence of abortion is only known in detail for those countries in which abortion is legally permitted with few restrictions and where official statistics are reasonably complete. The abortion rate refers to the annual number of abortions per 1,000 women of reproductive age. For many years, the lowest abortion rates in the world have been in the Netherlands, Belgium, and Scandinavia (about 5–6/1,000 women aged 15–44). These countries are characterized by a culture of contraceptive responsibility and some of the world’s most liberal abortion laws, with services legal, free, and widely available. The highest abortion rates in the world are found in many former Soviet Bloc republics, where family planning services have been severely lacking. The total abortion rate (TAR) expresses the average number of abortions experienced by a woman during her childbearing years. It is highest in Georgia at 3.7
Abortion
abortions per woman. The TAR declines to low levels as more effective contraceptive methods become available and widely adopted. In the United States, 1.3 million abortions occurred in 2002 and each year, 2 out of every 100 women aged 15–44 have an abortion. At the current rate of 21 abortions per 1,000 women aged 15–44, over one-third (35 percent) of U.S. women will have had an abortion by the time they reach age 45. These levels are higher than in western Europe, Australia, or New Zealand, where contraceptive practice is more widespread and effective. Characteristics of Abortion Patients Both unintended pregnancy and abortion rates are higher among some groups of women. These typically include women under age 30 (especially those aged 20–24), unmarried women, those in poverty, and those with more disadvantaged racial/ethnic minority status. Although it is often assumed that women who have abortions and women who have children are different, in fact they are the same women at different points in their lives. Among U.S. women who have an abortion, 61 percent are already a parent and 52 percent intend to have children or more children in the future. Most women who choose to have an abortion do so because they feel unable in their current circumstances to fulfill their parental responsibilities as they would like, or to provide the kind of family support they believe their children deserve. With improved availability and new technologies for performing abortions, including medication abortion and vacuum aspiration with ultrasound, women are increasingly able to obtain an early-term abortion when it is safer and less traumatic. Within the United States, 9 in 10 abortions occur in the first 12 weeks of pregnancy and 3 in 5 occur at or before eight weeks’ gestation. The proportion carried out at or before six weeks’ gestation has increased from 14 percent of all abortions in 1992 to 25 percent in 2001. Less than 1 percent of women who have had an abortion did so at or after 21 weeks’ gestation. Individual and Societal Determinants of Abortion Women have abortions for many reasons. Most terminate their pregnancies because doing otherwise would limit their ability to meet their current
responsibilities and because they cannot afford the index child at that time. Even if it is dangerous or forbidden, many women will resort to abortion in order to protect their family from poverty or to conceal an illegitimate pregnancy where it is stigmatized. Unwanted pregnancy and unsafe abortion are frequently associated with sexual coercion and violence, particularly in adolescent girls. When asked for their reasons to have an abortion, 74 percent of recent U.S. abortion patients cited concern for or responsibility to other individuals. Almost as many (73 percent) said they could not afford a baby then; 69 percent said that having a baby would interfere with their education, employment, or ability to care for dependents; almost half (48 percent) said they were having relationship problems or would have to raise the child as a single parent; and 38 percent did not wish to have another child because they had already completed their childbearing. The incidence of abortion in society is primarily a function of the incidence of unintended pregnancy, which, in turn, is determined by the level of sexual activity, the age at which women marry, desired family size, and contraceptive knowledge and use. It follows that abortion rates will be higher where desired family size and effective contraceptive use are low, regardless of the legal status of abortion, or cultural and religious sanctions against the practice. Thus, compared to western Europe, abortion rates tend to be several times higher in Latin America and the Caribbean, in many sub-Saharan African countries, and in some Asian countries where contraceptive prevalence is low and access to safe, legal abortion services is limited. The U.S. abortion rate is higher than that found in other Western nations because of the higher proportion of pregnancies that are unintended (almost 50 percent), about half of which are aborted. As fertility preferences fall, both contraceptive use and abortion initially rise. Evidence from a diverse set of countries shows that over time, abortion rates fall as levels of contraceptive use increase further. In South Korea, both contraceptive prevalence and abortion rates increased as the average family size fell by over half between the 1960s and 1980s. After some 20 years, the birth rate began to stabilize, the abortion rate plateaued, and contraceptive prevalence continued to rise. Many Russian women who
wanted only two children had multiple abortions in their lifetimes, largely due to the poor accessibility and quality of contraceptive services and the ready availability of abortion. The situation finally changed in the early 1990s when the government began to promote contraception; over 1988–98, modern contraceptive use increased 80 percent while the abortion rate fell by 53 percent. Abortion Laws, Policies, and Health Consequences Some unintended pregnancies will always occur due to nonuse of contraceptives, difficulties with their use, and contraceptive failure. In addition, pregnancy itself may pose a threat to a woman’s life or to her physical and mental health. Due to such circumstances, almost all countries have adopted laws that allow a pregnancy to be terminated under specified conditions. Nearly all Western democracies permit abortion under broad social and health grounds, enabling women to obtain a medically supervised and extremely safe abortion early in pregnancy. The U.S. Supreme Court ruled in 1973 that restrictive state abortion laws were unconstitutional, thereby legalizing abortion throughout the nation. As in other countries, decriminalization of abortion led to an initial increase in abortion rates that subsequently declined as contraceptive practice improved. At the start of the 21st century, 60 percent of the world’s women were living in countries where early abortion is legally available on broad grounds, with 40 percent able to obtain the procedure on request, that is, without having to specify a reason. One in four (25 percent) were living in countries that allowed abortion only to save a woman’s life or prohibited the procedure altogether; 10 percent of women had legal access to abortion only when deemed necessary to protect a woman’s physical health or life; and 4 percent had access also if needed to protect a woman’s mental health. Of 145 developing countries, abortion was not permitted for rape or incest in 101 countries, for fetal impairment in 108, and for social or economic reasons in 118. It was not allowed even to preserve a woman’s physical health in 65 countries. Abortion is still frequently performed in such countries such that 20 million abortions, or about 41 percent of all procedures worldwide, are il-
Abortion
legal. However, the poor are least likely to get a safe clandestine procedure. Those who are both poor and living in rural areas, without access to hospital care for the complications that may follow an unsafe abortion, are at high risk of death. Access to safe abortion is heavily influenced by the actual implementation of laws and by societal and cultural views on sexuality and reproduction. Latin American countries generally severely stigmatize abortion and permit it only in the event of a threat to a woman’s life. However, safe abortion services are readily accessible for those who can pay for them. India legalized abortion in 1971 but has more abortionrelated deaths than any other country. Many women are unaware of the law, few primary health centers provide service despite being mandated to do so, and procedures are often performed by untrained persons in unhygienic conditions. Legal abortion does not guarantee safety in an environment where broad access to services under sanitary conditions is impeded or where providers are not trained. Restrictive laws and policies are invariably associated with a high incidence of unsafe abortion. When Romania banned access to abortion and contraceptive services in 1966, maternal deaths soared from 20 in 100,000 live births to as high as 150 in 1983. After the procedure was legalized again in 1990, maternal mortality fell sharply from 159 to 83 deaths/100,000 live births within a year and continued to fall thereafter. This fall coincided with a rapid rise in contraceptive prevalence as access to modern contraceptives improved. Hospital admissions for septic and incomplete abortion also fell sharply after South Africa legalized abortion in 1997. Each year, about 19 million women undergo unsafe abortions; 97 percent of these are in developing countries. One-third of these women will suffer serious complications, but fewer than half will obtain the hospital treatment they need. Unsafe abortion causes annually about 68,000 deaths, most attributable to hemorrhage, infection, and poisoning from substances used to induce abortion. Although unsafe abortion is preventable through cheap, effective interventions, almost 100 million women alive today will experience the risk and trauma of an unsafe abortion during their lifetimes if no new actions are taken. African women experience the greatest risk of death from unsafe abortions, with a ratio of 1 in 150
Abortion
compared to Asia’s 1 in 250, Latin America’s 1 in 800, and northern countries’ 1 in 3,700. The consequences are especially serious for poor, young, and uneducated women. Morbidity from unsafe abortion burdens impoverished healthcare services and consumes scarce resources. The cost of providing safe abortion services would be many times lower. In more affluent countries, legal abortion is one of the safest procedures in medical practice, with case fatality rates below 1 death per 100,000 procedures. Abortion is far less likely than an injection of penicillin to cause death and is considerably safer than carrying a pregnancy to term. Surgical and Medical Methods Vacuum aspiration is the preferred surgical method prior to 12 weeks’ gestation. The vacuum can be generated either by an electric pump or with a handheld plastic syringe. Dilatation and curettage (D&C) remains widely used in developing countries, but carries higher risk and is more painful. Medication abortion performed within nine weeks of the last menstrual period is safe, effective, and acceptable to most women, with fewer than 5 percent of cases needing a subsequent surgical intervention for incomplete abortion. The regimen comprises an initial dose of mifepristone (an antiprogrestogen) followed by a prostaglandin, usually misoprostol. This essentially changes the procedure from one requiring surgical skills to one requiring only patient-management skills and can enable a shift toward earlier abortions, which reduces the risk of complications. Mifepristone, popularly referred to as “the abortion pill” or by its earlier acronym, RU-486, was first approved in France in 1988 and its use for early-term abortion is spreading in many countries. Postabortion Care Postabortion care (PAC) is increasingly being instituted worldwide as a critical healthcare service that can save women’s lives in settings where abortion is performed unsafely. PAC should be offered promptly after all abortions, whether medical or surgical, as well as for miscarriages. It has three essential components. First, emergency treatment of postabortion complications must be provided. Manual vacuum aspiration (MVA) is the preferred procedure for treating
incomplete abortions. It is safer and less expensive than D&C, and can be performed effectively in lowresource settings. Second, postabortion patients need strengthened family planning counseling and contraceptive method provision, both immediately after a procedure and in subsequent follow-up, to better space or prevent subsequent pregnancies. Third, referrals should be provided for other reproductive health services such as sexually transmitted infection (STI) and human immunodeficiency virus (HIV) prevention education, screening, diagnosis, and treatment; screening for sexual and/or domestic violence, with treatment as needed; and for medical, social, and economic services and support. In addition, PAC programs increasingly recognize the need to build partnerships with communities. Abortion can be made both safer and rarer. Improved contraceptive practice is critical to reducing the incidence of abortion. New technologies allow women to obtain earlier and safer abortions. Laws and policies should reflect health concerns. Access to safe abortion can be improved through decreasing administrative barriers to legal abortion services that may be performed under the indications allowed by a country’s law, particularly in public sector facilities. PAC programs increasingly stress a continuum of postabortion care. Much more work is needed in this vital area to prevent unsafe abortion and improve the lives of women and their families. SEE ALSO: Birth Control/Contraception; Infertility; Preg-
nancy Loss; Public Health; Reproductive Health; Sexual Health; Women’s Health. BIBLIOGRAPHY. Heather Boonstra, et al., Abortion in
Women’s Lives (Guttmacher Institute, 2006); CATALYST Consortium, PAC Compilation Document (United States Agency for International Development, 2005); Andrzej Kulczycki, The Abortion Debate in the World Arena (Routledge, 1999); World Health Organization, Safe Abortion: Technical and Policy Guidance for Health Systems (World Health Organization, 2003); World Health Organization, Unsafe Abortion: Global and Regional Estimates of the Incidence of Unsafe Abortion and Associated Mortality in 2000 (World Health Organization, 2004). Andrzej Kulczycki, Ph.D. University of Alabama at Birmingham
Acid Reflux
Abse, Dannie (1923– ) Dannie Abse, a Welsh writer and pulmonologist, is considered one of Britain’s most important contemporary poets. Abse’s poems, plays, essays, and novels have met both critical and popular success due to his ability to signify universal themes through frank depictions of daily life. His writing is influenced by his experience of his Welsh nationality and his Jewish heritage, his occupation as a physician, and a strong awareness of social issues. Abse was educated at the University of Wales, Kings College in London, and Westminster Hospital, and received his medical license in 1950. He spent four years in the Royal Air Force, and in 1955 joined the London Chest Clinic. He has served both as a physician and a freelance writer until his recent retirement from medical practice. Abse published his first collection of poems, After Every Green Thing (1948) while in medical school, and has since published over 20 works, including novels, books of poetry, and memoirs. He had three children with art historian Joan Mercer, his wife of over 50 years until her death in 2005. Abse’s early work does not focus on his identity as a physician. He began to explicitly incorporate his medical experiences into his work early in the 1960s. He writes frequently about the tension between his clinical and literary identities: the symbolic “white coat” and “purple coat” figure repeatedly in his poetry. Abse’s social consciousness extends too to his regard of the medical profession in his consideration of medical ethics. Funland and Other Poems (1973) is considered one of his best volumes of poetry. One of his most famous medical poems, “In the Theatre (A True Incident),” can be found as a part of this volume. Among the many awards he has received are the Arts Council of Wales Literature Award for his volume of Selected Poems (1970) and his play Pythagoras (1979), a Jewish Chronicle Book Award (1970), and the Cholmondeley Award in 1985. Abse has also served as a Senior Fellow of the Humanities at Princeton University (1973–74), President of the Poetry Society (1978–92), was named a Fellow of the Royal Society of Literature in 1983, and a Fellow of the Welsh Academy of Letters in 1992. SEE ALSO: Chekhov, Anton; Da ������������������� Vinci, Leonardo.
BIBLIOGRAPHY. Tony Curtis, Dannie Abse (University of
Wales Press, 1985); The Poetry Archive, “Dannie Abse: Recordings,” www.poetryarchive.org (cited November 2006).
Constance W. Liu, M.D. Case Western Reserve University
Acid Reflux Acid reflux, also known as gastroesophageal reflux disease (GERD) or chronic heartburn, is a medical condition characterized by abnormal backflow of acid from the stomach to the esophagus. It is one of the most common disorders of the gastrointestinal tract and it is estimated that 3 to 4 percent of the population has GERD, while up to 40 percent of the population experience heartburn, the most common symptom associated with GERD, at least once a month. The various causes of acid reflux generally lead to the same symptoms and can be diagnosed through a careful patient history and some diagnostic exams. Treatment ranges from conservative management through lifestyle changes, to the use of medications and potentially to surgery. Possible complications from untreated acid reflux include Barrett’s esophagus and esophageal cancer. In normal individuals, acid is secreted in the stomach to aid in the digestion of food. This acid is usually kept in the stomach and prevented from flowing backward into the esophagus by a zone of constricting muscles called the lower esophageal sphincter (LES). The strength of the LES is also supported anatomically by the muscles of diaphragm. Generally speaking, acid reflux occurs when the LES fails to keep acid and stomach contents from refluxing into the esophagus. The various causes of acid reflux fall into two general categories: decreased strength or tone of the LES and increased stomach filling. Decreased LES tone is associated with pregnancy, smoking, certain drugs (anticholinergic drugs and smooth muscle relaxants), foods (fatty foods, peppermint, chocolate), previous surgery (especially Heller myotomies for achalasia), and hiatal hernias (where the LES is displaced from its normal location below the diaphragm to above it). Increased gastric filling is associated with the ingestion of large meals,
Acne
hypersecretion of acid (as can be seen in ZollingerEllison syndrome), and decreased stomach motility. Symptoms and Diagnosis By far the most common symptom associated with acid reflux is heartburn, which is the feeling of acid from the stomach irritating the lining of the esophagus. While the stomach is equipped to deal with a highly acidic environment, the esophagus is not and therefore acid acts as a strong irritant to the esophagus. Acid can also reflux higher up into the esophagus and enter and irritate the lungs, throat (pharynx, larynx), and mouth. In these cases, patients can develop chest pain, pneumonia, cough, a sour taste in the back of the neck, or even erosion of the dental enamel. Long-term acid reflux can lead to strictures or narrowing of the esophagus due to chronic irritation and can cause dysphagia (difficulty swallowing). The diagnosis of acid reflux is often based on history, but can be confirmed through a trial treatment of medication and other diagnostic exams. Those with symptoms suggestive of acid reflux are started on medical therapy, generally a proton-pump inhibitor, and are followed for response. A resolution of symptoms would confirm the diagnosis and not warrant any further measures. Those who have persistent symptoms require further tests, which can include 24-hour pH monitoring, barium swallow, and esophagoscopy. Treatment and Complications Treatment is aimed at reducing symptoms, healing areas of inflammation, and preventing complications. It ranges from lifestyle changes to medicines to surgery. Lifestyle changes include smaller meals, sleeping with the head of the bed raised, weight loss, smoking cessation, and reducing consumption of aforementioned associated foods and drugs. Medications that are used include H2-blockers and proton-pump inhibitors. The surgical procedure for acid reflux is called a fundoplication (wrapping part of the upper stomach around the LES to reinforce it) and is reserved for those who would require longterm high-dose proton-pump inhibitors. Prolonged and untreated acid reflux can lead to a condition known as Barrett’s esophagus, which is when the cells lining the esophagus change from squamous epithelium (their usual cell type) to columnar epithe-
lium (a cell type found in the intestine) in a process called metaplasia. The change is considered to be a defense mechanism because columnar epithelial cells can secrete mucus that is protective against the acid refluxing into the esophagus. However, the progression to Barrett’s esophagus is considered a step toward developing esophageal cancer. People with Barrett’s esophagus have 30 to 125 times the risk of developing esophageal cancer than the general population. SEE ALSO: Esophageal Cancer; Esophagus Disorders. BIBLIOGRAPHY. Raj Goyal, “Diseases of the Esophagus,”
Harrison’s Principles of Internal Medicine, 16th ed. (McGraw-Hill, 2005); James W. Freston, ed., Diseases of the Gastroesophageal Mucosa: The Acid-Related Disorders, (Springer-Verlag, 2001).
E. John Ly, M.D. Brown University
Acne The everyday pimples and pus-filled papules (small bumps) many adolescents and young adults see on their faces, chests, and backs are known medically as acne. The most frequent form of acne is acne vulgaris. Acne is highly prevalent during puberty and adolescence and may be associated with psychological effects such as reduced self-esteem or depression. Many people see improvement after puberty, but this is not always the case. Acne crosses all racial and social boundaries. It is most common in persons aged 9–19 years and estimates are that 75–95 percent of the adolescent population is affected. However, it has been known to occur in infants and older adults as well. It is estimated that among adults over the age of 25, 40 percent of men and 54 percent of women have some degree of acne. The high prevalence of acne vulgaris is related to the multifactorial nature of the disease. First, it is considered to have a hereditary/genetic component. Second, it is linked to hormone levels in the body, specifically androgens, which are male sex hormones found in both genders (but slightly higher in boys, accounting in part for the increased prevalence in
Acoustic Neuroma
boys). Changes in hormonal activity (during a woman’s menstrual cycle, pregnancy, or stress) may also be associated with the development of acne. In new adult onset acne, a medical disease etiology should be ruled out, such polycystic ovary syndrome in women or Cushing’s syndrome. More commonly though, as during puberty, the increased “sex hormone” activity in both genders leads to increased sebum production by the sebaceous glands. In the genetically susceptible individual, however, there are changes in the keratinocytes (skin cells) lining the pore, whereby the cells become sticky and a clump of cells forms. This cell clumping leads to the development of a comedone, which is the initial step in the development of acne. Subsequently there is an accumulation of dead skin cells, bacteria and sebum in the follicle, to which the skin reacts with an inflammatory defense reaction. In an attempt to try to eliminate these contents, white blood cells are called into the area leading to the typical reaction of heat, redness, pain, and swelling.
warm water and mild antibacterial soap twice a day. The use of an over-the-counter topical treatment containing benzoyl peroxide or salicylic acid can also help to prevent further lesion development. When dealing with a moderate or severe case of acne, a physician can prescribe oral antibiotics, oral contraceptives (for women), topical retinoids, or topical antimicrobials. Typically, a combination of these treatments, such as oral antibiotics and topical retinoids, is necessary. In the case of nodular or severe cystic acne, incision and drainage of the lesions may be required. Furthermore, a physician may also prescribe isotretinion (Accutane) to prevent the development of cysts and new lesions. It is important to note that the treatment of acne takes time to produce results. If there is no noticeable change within 12–16 weeks, the method of treatment may need to be modified. Once there are signs of improvement, it is necessary to continue these treatments in order to prevent recurrences.
Symptoms and Diagnosis Acne vulgaris can be expressed with varying degrees of severity, and is classified as mild, moderate, or severe (nodular-cystic) acne. Mild acne is characterized by the appearance of closed and open comedones, more commonly known as whiteheads and blackheads, respectively. Comedones are characterized by the open hair follicle or pore being clogged (plugged). Closed comedones, or whiteheads, refer to the plug being buried beneath the skin’s surface. In contrast, open comedones, also known as blackheads, are exposed to the surface of the skin and are darkened due to oxidation. Other visible lesions such as papules (small, tender, pink bumps) and pustules (red pimples containing pus) are also an indication of acne. When comedones are accompanied by papules and pustules, it is considered to be a moderate type of inflammatory acne. Some individuals may also have pimples that form below the skin and can be solid (nodules) or filled with pus (cysts). This type of acne is referred to as nodular acne and represents a severe form of the disease.
BIBLIOGRAPHY. American Academy of Dermatology,
Treatment and Management The goal of acne treatment is to prevent the development of new lesions and heal current lesions. For mild acne, this may be achieved by washing the face with
Acoustic neuromas are benign brain tumors derived from Schwann cells (cells that myelinate nerve axons in the peripheral nervous system) that affect cranial nerve VIII, the vestibulocochlear (acoustic) nerve. Acoustic
SEE ALSO: Adolescent Health; Skin Diseases (General).
“What Is Acne?” www.skincarephysicians.com/acnenet (cited June 2006); L. Cordain, S. Lindeberg, M. Hurtado, et al., “Acne Vulgaris: A Disease of Western Civilization,” Archives of Dermatology (v.138, December 2002); Mayo Clinic, “Acne,” www.mayoclinic.com (cited September 2006); National Institute of Arthritis and Musculoskeletal and Skin Diseases, “Questions and Answers about Acne,” www. niams.nih.gov (cited January 2006); National Institute of Arthritis and Musculoskeletal and Skin Diseases, “What Is Acne? Fast Facts: An Easy-to-Read Series of Publications for the Public,” www.niams.nih.gov (cited August 2006). Shalu S. Patel Nidhi J. Avashia Lauren Siliati Independent Scholars
Acoustic Neuroma
Acquired Immunity
neuromas are known by several other names: acoustic schwannomas, acoustic neurinomas, vestibular schwannomas, and vestibular neurilemomas. Symptomatically, acoustic neuromas affect people worldwide at an incidence of 1 per 100,000 person-years; the actual incidence of the disease is even higher considering that many acoustic neuromas are asymptomatic. Acoustic neuromas are more common in people between the ages of 30 and 50. They usually occur unilaterally, with an equal prevalence between the right and left side. Established risk factors for acoustic neuroma include acoustic trauma (chronic exposure to extremely loud noise), parathyroid adenoma, and neurofibromatosis. It should be noted that bilateral acoustic neuromas primarily occur in patients with neurofibromatosis. The clinical presentation of acoustic neuroma depends on the particular nerve that it affects. Almost all patients have involvement of the acoustic nerve, which manifests as hearing loss and tinnitus (a ringing sound in the ear[s]). A majority of patients also have involvement of the vestibular nerve (a branch of the vestibulocochlear nerve), which will present as unsteadiness. A smaller fraction of patients will have involvement of cranial nerve V (trigeminal nerve) and cranial nerve VII (facial nerve). If the former nerve is affected, patients may experience facial numbness or pain; if the latter nerve is involved, symptoms may include facial paralysis and taste disturbances. Tumor progression to involve other brain structures may result in problems with speaking and/or swallowing, ataxia (incoordination), hydrocephalus, and death. Diagnosing acoustic neuromas relies on physical examination, audiometry, and imaging. On physical examination, patients may present with the symptoms mentioned above. Audiometry, a more formal hearing test, shows abnormalities in at least 90 percent of patients with acoustic neuroma. On imaging, magnetic resonance imaging (MRI) is the preferred modality because of its greater power of detection compared to computed tomography (CT). However, CT can be used in patients who cannot tolerate MRI. There are three treatment options for acoustic neuroma: surgery, radiation therapy, and observation. Surgery is a favorable option for otherwise healthy patients because of its extremely high cure rate and very low mortality rate; 98 percent of cases have complete
tumor removal and only 1 percent result in death. Complications after surgery can include cerebrospinal fluid (CSF) leaks, headaches, and cranial nerve palsies. Radiation therapy is also associated with very high success rates and can be used in patients with small (<3 centimeter) tumors or those who are not candidates for surgery due to age, preexisting medical conditions, and so forth. Observation, consisting of regular imaging once or twice a year, is a reasonable choice because fewer than half of acoustic neuromas show evidence of growth. Complications with observation are those of tumor growth: increased hearing loss, brainstem compression, and hydrocephalus. Acoustic neuromas will always affect people around the world. Fortunately, treatment options to battle this tumor are increasingly effective. SEE ALSO: Brain Cancer; Cancer Radiation Therapy; Hy-
drocephalus; Neurofibromatosis; Parathyroid Disorders.
BIBLIOGRAPHY. William F. House, Charles M. Luetje, and
Karen Jo Doyle, Acoustic Tumors: Diagnosis and Management (Singular, 1997); Leonard I. Malis, Acoustic Neuroma (Elsevier Science, 1998). Khoi D. Than, M.D. Johns Hopkins University School of Medicine
Acquired Immunity Acquired immunity is the cumulative development over a lifetime of the body’s ability to fight off disease caused by invading agents with antibodies and specialized lymphocytes, one type of white blood cells. Each person’s immune system is unique, defined by genetic coding with an ability to distinguish self-cells from foreign invaders, with some exceptions, including autoimmune diseases or immunodeficiency. The immune response can be activated through either active or passive means. Active immunity is the development of an immune response by exposure to either the disease or by vaccination. Exposure to the invading agent and developing the illness activates the immune system for recovery and stores the information in memory cells. Immunizations stimulate body tissues to form
antibodies and develop memory cells to store information without causing the illness. Passive immunity provides protection after exposure to a pathogen by direct injection of specific antibodies and generalized human-derived immune globulins. Also, for some cancers, specific T-lymphocytes can be grown in a lab from a person’s own cells and then reinjected. Mothers can provide passive immunity to newborns and infants; immune globulin (IgG) crosses the placenta to provide some initial immunity to newborns and immune globulin (IgA) passes to the infant in the colostrum of breast milk. Immunity is also categorized by source, either natural or artificial. Natural sources include exposure to disease or pathogen or conferred immunity from mother to child. Artificial sources include immunization or direct injection of antibodies from a source outside the body. The body uses two methods of specific defense against invading agents: The humoral defense with the creation of antibodies, and a cell-mediated response where the immune system activates specialized T-lymphocytes, also known as natural killer cells, to destroy the infected cells. B-lymphocytes (B-cells) make and secrete antibodies with a few acting as memory cells to ensure lasting immunity is produced in the bone marrow and in the fetal liver. Each lymphocyte is programmed to recognize only one specific antigen, yet B-lymphocytes can respond to millions of different antigens, both naturally occurring and artificially created. T-lymphocytes are produced in the thymus and directly attack and destroy infected cells. When the body is exposed to an invading agent, helper T-cells (also known as CD4 cells) send a signal to the B-cells to initiate the humoral response and begin antibody production. The immune system utilizes B-cells to recognize and identify the invading agent. The B-cells produce and release antibodies through the humoral response, and some B-cells commonly called memory cells record and retain the information specific to the antigen to provide long-lasting protection against each specific invading agent. The Y-shaped antibodies have receptor binding sites that attach to the antigen or invading agent. Antibodies work in three similar, though different, ways: by binding to several antigens to form a clump to be devoured by phagocytes, by the complement
Acquired Immunity
Immunizations stimulate body tissues to form antibodies and develop memory cells that can recognize an invader.
system that brings water into the cells causing the cells to burst, and by opsonization coating the invading cells with antibodies with a constant region providing a receptor site matching a receptor on the phagocyte, allowing the phagocyte to engulf and destroy the invading agent. The cell-mediated response is slower. T-cell division can take up to seven days to reach full capability in humans. Although delayed, once the cytotoxic Tcells and natural killer cells reach the site of infection, they directly attack and destroy infected cells. Once the danger has passed, suppressor T-cells slow down and turn off the immune response. The first or primary immune response to an invader not previously encountered can be slow. The secondary immune response relies on the memory cells of B-lymphocytes and T-lymphocytes. If the invading agent shows up again in the body, the memory cells immediately recognize the invader and trigger antibody
10
Acquired Mutation
production; the person may not even know they were exposed to the invading agent. SEE ALSO: Active Immunity; Autoimmune Diseases; Im-
mune System and Disorders; Infectious Diseases; Passive Immunity.
BIBLIOGRAPHY. Ben Harder, “Seeking Immunity,” Popular
Mechanics (September 2006); Howard Hughes Medical Institute Report, New Ways to Boost the Body’s Defenses Arousing the Fury of the Immune System (Howard Hughes Medical Institute, 1998); Jeffrey L. Kishiyama and Daniel C. Adelman, “Allergic and Immunologic Disorders,” Current Medical Diagnosis and Treatment (Lange Medical Books, 2004). Lyn Michaud Independent Scholar
Acquired Mutation Also known as somatic mutation, acquired mutation is an alteration of genetic matter that occurs after the time of conception and affects somatic cells (as opposed to mutations that affect germ cells). A principal consequence of affecting only somatic cells is that such mutations cannot be passed to offspring. However, acquired mutations are normally transmitted to all cells descended from the original mutant cell, giving rise of a clone (colony) of cells bearing the acquired mutation. Mutations of this sort are critical in the development of various cancers. The Weinberg Progression Model identifies six acquired characteristics shared by all tumors, but the relative role inheritance and acquired mutation play in each characteristic is a complex function of the disease in question, the family history of the subject, and other factors, such as environmental exposure. Of greatest importance in the study of modern medical practices are self-sufficiency in growth factors and the loss of inhibition to growth factors. Proto-oncogenes are normal genes that encode proteins responsible for normal cellular growth. When subject to acquired mutation, proto-oncogenes may become oncogenes, leading to unregulated cell growth and proliferation. Typically, oncogenes act in a dominant manner, needing only one mutated copy (out of two)
to have a physiological impact. In contrast, tumor suppressor genes, which encode proteins responsible for antigrowth signals, typically function in a recessive manner and require mutations to both copies before physiological consequences manifest themselves. Individuals who are born heterozygous for a tumor suppressor gene (via inherited mutation) require only one acquired mutation event to alter the antigrowth signaling pathway, whereas individuals born without such a hereditary mutation require two acquired mutation events to yield the same outcome. For example, mutation to the HER2 gene contributes to the uncontrolled growth of approximately 30 percent of breast cancers. Targeting this over expression mutant is a key strategy in chemotherapy for breast cancer. The retinoblastoma tumor suppressor protein, pRb, needs to be present in at least one copy in order to prevent the development of retinoblastoma. In individuals who inherit only one wild-type allele, an acquired mutation can precipitate sporadic retinoblastoma. SEE ALSO: Cancer; Germ Line Mutation; Programmed
Cell Death.
BIBLIOGRAPHY. R.L. Nussbaum, et al., Thompson &
Thompson: Genetics in Medicine, 6th ed., revised reprint (Saunders, 2004); Karol Sikora, ed., Genes and Cancer (Wiley & Sons, 1990).
Bimal P. Chaudhari Boston University
Active Immunity Active immunity is the development of a secondary immune response retained by B-lymphocyte and Tlymphocyte memory cells to confer long-term protection from specific diseases caused by pathogens. Active immunity is achieved through immunization or by contracting the illness and having the body’s immune response identify and eliminate the pathogen. Memory cells store information about the pathogen in preparation to activate the antibody response against another invasion. The Centers for Disease Control and Prevention (CDC) studies the epidemiology, or prevalence
within a society, of certain diseases and makes recommendations for immunization based on research and surveillance. Current recommended early childhood immunizations provide protection from some of the more prevalent and virulent diseases including measles, mumps, rubella, hepatitis B, varicella, diphtheria, tetanus, polio, whooping cough (pertussis), influenza, and pneumococcal disease. Recommendations change as new research shows changes in epidemiology or with development of new vaccines. Adult immunization is based on risk factors including previous vaccination history or potential for exposure to pathogens. Since 2001, military personnel, healthcare workers, and first responders to emergency situations have been recommended to have smallpox vaccination in the event of an outbreak. Travelers in foreign countries may be required to have vaccinations for endemic diseases even when the risk of contracting the disease is low in order to control the spread of the disease. To prevent outbreaks of disease, some workplaces, including healthcare facilities, schools, and colleges, confirm and maintain records of immunization. When in doubt, a blood test can confirm active immunity, the presence of antibodies to a specific pathogen. Vaccines are made from a weaker form of the antigen, attenuated (modified to not cause disease) or inactivated antigens. Some newer vaccines activate an immune response with exposure to only one or two proteins from the pathogen inserted in a circular DNA plasmid. After injection, the muscle cells cause the pathogenic protein to be replicated and this foreign protein triggers the immune response and memory cell production. In case of future infection by the pathogen, the immune system will recognize the specific protein on the pathogen and produce the antibodies to destroy the pathogen before it can cause illness. Instead of being a primary antibody response to a full-blown disease, immunization causes the creation of memory cells to form secondary immune response or an artificially produced form of active immunity. Active immunity is not immediate and cannot be relied upon to prevent the development of the disease once an individual has been exposed to a pathogen. The immune system needs time to activate the cascade of responses to fight off infection. Once complete, the body will have the ability to maintain higher levels of antibodies for longer periods than if the antibody were injected directly into the body. Antibod-
Activities of Daily Living (ADL)
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ies and cytotoxic or natural killer cells are active for a limited duration. When the immune response turns off after the infection is destroyed, antibodies and cytotoxic or natural killer cells die. B-lymphocyte memory cells and T-lymphocyte memory cells recognize antigens from a previous invasion. Memory cells, unlike other cells in the immune system producing the immune response, live on in the body for decades. When the memory cell encounters the specific antigen it was created to recognize, the antigen is immediately recognized and a rapid immune response is activated. The B-cell or T-cell undergoes rapid cell division to create a large defense arsenal to destroy the invader before the disease can start. Active immunity also provides public protection to those who have not been vaccinated. Infectious diseases are normally infectious during active outbreak. When the body produces antibodies to the specific pathogen before development of the disease, the ability to pass on the pathogen is limited. Over time and with vigilant vaccination, a disease can be eradicated, as smallpox was considered to be with the last known case in the late 1970s. Constant monitoring for new and reemerging infectious diseases and availability of new vaccines will enhance public health. SEE ALSO: Acquired Immunity; Infectious Diseases; Im-
munization/Vaccination.
BIBLIOGRAPHY. Josh Fischman, “Sticking It to Cancer,”
US News & World Report (April 3, 2006); Howard Hughes Medical Institute, New Ways to Boost the Body’s Defenses Arousing the Fury of the Immune System (Howard Hughes Medical Institute, 1998); Harry W. Lampiris, Daniel S. Maddix, and Steven L. Barriere, “Vaccines, Immune Globulins and Other Complex Biologic Products,” in Basic and Clinical Pharmacology (Appleton & Lange, 1998). Lyn Michaud Independent Scholar
Activities of Daily Living (ADL) Activities of Daily Living (ADL) refers to the regular, everyday tasks that are necessary for independent living and self-care. These typically include: bathing,
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Acupuncture sation for Economic Co-operation and Development (OECD); the World Health Organization and EuroREVES have led more recent efforts. SEE ALSO: Arthritis; Dementia; Disabilities (General); Re-
habilitation; Seniors’ Health (General); Stroke.
BIBLIOGRAPHY. Ian McDowell and Claire Newell, Mea-
suring Health: A Guide to Rating Scales and Questionnaires (Oxford University Press, 1996); Claire Gudex and Gaetan Lafortune, “An Inventory of Health and Disability-Related Surveys in OECD Countries,” OECD Labour Market and Social Policy Occasional Papers (no. 44, 2000).
Measuring everyday tasks that are necessary for independent living helps predict healthcare utilization, mortality, and cost of healthcare.
dressing, toileting, continence, eating, and transferring (the ability to get out of a bed or chair). The concept guides the measurement of physical functioning in the elderly and individuals who experience limiting conditions, such as arthritis or stroke. ADL measures have been found to be predictors of a variety of outcomes, including healthcare utilization, mortality, and cost of healthcare. They are used as a basis for estimating population health needs, and as a basis for determining benefits in private and public health insurance schema. A variety of instruments to measure ADL exist. The most frequently used measurement instrument is the Katz ADL Scale, which has been repeatedly validated since it was first published in 1963. Other instruments have since developed: The Instrumental Activities of Daily Living (IADL) measure was developed to measure higher functions, such as shopping, cooking, doing housework, using public transportation, using the telephone, and balancing a checkbook. Functional status measurements frequently incorporate both ADL and IADL. Instruments of ADL are ideally selected for sensitivity to a specific context, disease, or level of function. These instruments tap into the same construct of disability and function, but are not comparable. This has led to efforts to develop standard global instruments: Early efforts were managed by the Organi-
Constance W. Liu, M.D. Case Western Reserve University
Acupuncture Acupuncture is one of the most ancient healing modalities, dating back to 6000 b.c.e. It has roots in China but is practiced worldwide today, both within and without the framework of traditional Chinese medicine (TCM). Until recently, there were few randomized trials proving the efficacy of acupuncture, but research now demonstrates success for many different conditions. The Yellow Emperor’s Classic of Internal Medicine was the first document to depict acupuncture. During the 6th century, Korea and Japan began integrating forms of TCM, such as acupuncture and herbals, into their medical traditions. Acupuncture first entered the Western world in France, when Jesuit missionaries returned with accounts of this technique in the 16th century. French clinicians took quickly to the practice; however, it was not until the early 1800s that America and Britain showed interest in acupuncture. The goal of acupuncture is to remove obstructions or rebalance the flow of qi (also spelled ch’i), the vital life force that pulses through the body. Disease results from an imbalance in the forces of yin and yang. Yin, often thought of as the feminine form, is linked with cold, stasis, and tranquility. The masculine counterpart, yang, represents stimulation, assertiveness, and heat. Through the balanced interplay of these forces, well-being is achieved. In the
absence of this, disease has the potential to surface and obstruct the movement of qi. Qi flows throughout the body in a series of meridians (paths) set within the musculature. Needles (usually stainless steel) are placed at specific points to release the obstruction, both to treat illness and promote health. Over 365 documented acupuncture points exist on the human body. Some of these points correspond to organs and organ systems, much in the way that Chapman’s points are described in osteopathic medicine—as a manifestation of the viscerosomatic reflex. Many specialized forms of acupuncture exist, such as ear, scalp, and hand treatment. The auricular microsystem is one of the most commonly used, with over 200 points on the outer ear corresponding to other body regions. When these points are treated, a stimulus is felt to be sent through the brain to a respective location on the body via an electrical impulse. Hand acupuncture began in Korea when acupuncturists noticed patients experienced relief from other body aches following a hand treatment. Modern scalp acupuncture differs from traditional body acupuncture in three ways. Rather than following the typical channels of the body, scalp points are mapped out in zones correlating to various regions and differing functions. There is also variance in the depth and angle of needle placement. Finally, scalp acupuncture employs rapid stimulation of needles, unlike the low-pulsing technique of traditional therapy. After thousands of years in practice, acupuncture entered the research arena in the 1950s throughout China. During this time, the medical community sought evidence-based explanations for the benefits patients had been experiencing for millennia. J.S. Han of Beijing heralded these efforts, as he studied the neurotransmitter release accompanied by acupuncture. Practitioners develop individualized treatments for each patient, which leads to barriers when one tries to standardize care in order to study efficacy for a specific condition. Many studies are inconclusive, primarily due to poor methodology, and most trials are small with insufficient power. Improper blinding raises doubts on reliability and most acupuncture studies do not resemble clinical practice. Collaboration between experienced acupuncturists and investigators is necessary to accurately apply methodology, while preserving the essence of the practice.
Acupuncture
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Some conditions have responded well to acupuncture, and evidence exists to support the use of acupuncture for adult postoperative and chemotherapy nausea, nausea of pregnancy, knee osteoarthritis, and postoperative dental pain. The data are less conclusive, yet still viable, for asthma, back pain, headaches, drug dependency, and rheumatic disorders. There are numerous reports on the safety of acupuncture, with most adverse effects similar to other practices that use needles: infections, pneumothorax, organ punctures, and broken needles left in skin. Some patients feel tired, lightheaded, or have pain and bruising at the insertion site. With the use of sterile, disposable needles, the incidence of infection has greatly diminished, and overall, acupuncture is a safe modality. The conventional educational process for acupuncture is between 2,000 and 3,000 hours in accredited master-level programs, but varies regionally. Other programs require fewer hours but higher degrees to enroll. In a rapidly growing field, physicians and nonphysicians alike are being trained in the practice. With an augmented interest in alternative forms of healthcare, patients are examining new ways to treat old problems. SEE ALSO: Alternative Medicine; National Center for
Complementary and Alternative Medicine (NCCAM); Osteopathic Medicine; Traditional Chinese Medicine. BIBLIOGRAPHY. B. Berman, et al., “Effectiveness of Acu-
puncture as Adjunctive Therapy in Osteoarthritis of the Knee, a Randomized Controlled Trial,” Annals of Internal Medicine (v.141/12, 2004); E. Ernst, et al., “Prospective Studies of the Safety of Acupuncture: A Systematic Review,” American Journal of Medicine (v.110, 2001); K. Kaptchuck, “Acupuncture: Theory, Efficacy and Practice,” Annals of Internal Medicine (v.137/8, 2002); A. Lewin, “Acupuncture and Its Role in Modern Medicine,” Western Journal of Medicine (v.120/1, 1974); H. Macpherson, et al., “Patient Reports of Adverse Events Associated with Acupuncture Treatment: A Prospective National Survey,” Quality & Safety in Health Care (v.13/5, 2004); G. Mestler, “A Galaxy of Old Japanese Medical Books with Miscellaneous Notes on Early Medicine in Japan. Part II. Acupuncture and Moxibustion. Bathing, Balneotherapy and Massage, Nursing, Pediatrics and Hygiene. Obstetrics and Gynecology,” Bulletin of the Medical Library Association (v.42/4, 1954); “NIH Consensus Confer-
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Addison’s Disease
ence. Acupuncture,” Journal of the American Medical Association (v.280/17, 1998); I. Veith, “Acupuncture in Traditional Chinese Medicine. An Historical Review,” California Medicine (v.118/2, 1973); A. White, et al., “A Brief History of Acupuncture,” Rheumatology (Oxford) (v.43/12, 2004); World Health Organization, Viewpoint on Acupuncture (World Health Organization, 1979). Gautam J. Desai, D.O. Sharlene A. Murphy Kansas City University
Addison’s Disease Addison’s disease is a chronic condition involving metabolic dysfunction during which adrenal glands cannot produce enough of a particular hormone, which can, in turn, lead to fatigue, low blood pressure, loss of appetite, and the darkening of the pigmentation of the skin. This is caused by atrophy of the adrenal cortex. Although the condition has been known for many years, it was the English physician Thomas Addison who managed to correlate a set of disease symptoms, and along with another physician, Richard Bright, at Guy’s Hospital, London, wrote Elements of the Practice of Medicine (1839), and then wrote On the Constitutional and Local Effects of Disease of the Supra-Renal Capsules (1855). His book, An Essay on the Operation of Poisonous Agents upon the Living Body (1829), coauthored with John Morgan, was the first English book on the condition, which was named Addison’s disease after him, with Addison’s (pernicious) anemia also named after him. The traditional development of Addison’s disease is for it to get progressively worse over a number of months. Gradually, the patient encounters a loss of appetite, leading to weight loss, muscle weakness, and chronic fatigue as his/her condition deteriorates. This is often accompanied by nausea, diarrhea, or vomiting, with areas of hyperpigmentation—a darkening of skin color—and often depression and/or increased irritability. There can also be a craving for salt or salty food, with many women experiencing irregular menstrual periods, or periods that stop entirely. Medical doctors examining patients for Addison’s disease usually look for signs such as hypoten-
sion (low blood pressure), which gets worse when a person is standing; an increasing numbness in the extremities; decreased blood volume; dehydration; tetany, particularly after drinking milk; tremors; and restlessness. Often patients, especially children suffering from Addison’s disease, will be found to have extremely low blood sugar levels. Diagnosis to confirm Addison’s disease takes place when it has been shown that patients have adrenal hormone levels far lower than they should be, even after the stimulation of them with synthetic pituitary hormone. The most common cause of Addison’s disease in developed countries tends to be the autoimmune destruction of the adrenal cortex, which in turn leads to a proclivity to develop the adrenal autoimmune attack. Although this can happen in people without a family history of Addison’s disease, for many people, the disease is inherited. A large genetic component has been found not only in humans, but also in some dog breeds, such as standard poodles and boxers. It is now felt that between 80 and 90 percent of all humans suffering from Addison’s disease have it because their autoantibodies are directed against adrenal cells that contain 21-nydroxylase, the enzyme involved in the production of cortisol and aldosterone. Other cases can come from patients who have also been suffering from tuberculosis, HIV, sarcoidosis, amyloidosis, or metastic cancer. The development of cortisone by the American biochemist Edward C. Kendall during the period leading up to its first introduction in 1948 has massively changed the manner of treating sufferers of Addison’s disease. Kendall, along with fellow American Philip S. Hench and Swiss chemist and researcher Tadeus Reichstein, won the Nobel Prize for Physiology or Medicine in 1950. The methods of treating Addison’s disease vary considerably, with the crux of the treatment being the attempt to replace the missing cortisol, and if necessary using fludrocortisones to replace the missing aldosterone. If a person has an acute attack, known as an Addisonian crisis, it is often treated with intravenous injections of cortisone (or cortisol), a saline solution, and/or glucose. The hormone replacement therapy using treatment with cortisone has to continue for life, often only controlling the symptoms of the disease rather than totally treating it. Over history, many people have suffered from Addison’s disease. It is now thought that the British
Administration for Children and Families (ACF)
writer Jane Austen, who was believed at the time to have been suffering from bile, actually succumbed to Addison’s disease. Fellow British writer Charles Dickens may also have suffered from Addison’s disease. Other famous people who suffered this disease included U.S. president John F. Kennedy, popular singer Helen Reddy, and the scientist and astronomer Eugene Merle Shoemaker, the codiscoverer of the comet Shoemaker-Levy. SEE ALSO: Metabolic Disorders. BIBLIOGRAPHY. Jorn Nerup, Addison’s Disease: A Review
of Some Clinical, Pathological and Immunological Features (Mollers, 1974); Icon Health Publications, Addison’s Disease—A Medical Dictionary, Bibliography, and Annotated Research Guide to Internet References (Icon Health Publications, 2003). Justin Corfield Geelong Grammar School, Australia
Administration for Children and Families (ACF) The Administration for Children and Families (ACF) operates under the auspices of the Department of Health and Human Services and is charged with promoting the health and general well-being of children, families, and local communities. The mission of ACF is to encourage Americans to achieve economic independence and productivity within their own communities in ways that best serve the interests of the nation’s children and families. ACF works with Congress, states, health and community leaders, nongovernmental organizations (NGOs), and Native American groups to fulfill that mission. Special programs serve the interests of individuals with specific needs, including at-risk children and families, those with developmental disabilities, refugees, migrants, and runaway and homeless youth. The agency’s Web site (www.acf.dhhs.gov) provides a wealth of material on its activities, including fact sheets on relevant topics. The ACF is headed by an assistant secretary and a principal deputy assistant secretary who oversee various offices, such as Public Affairs, Family Assistance,
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Refugee Resettlement, and Children, Youth, and Families, which are charged with implementing policy and providing services to target groups. Headquartered at 370 L’Enfant Promenade, SW, in Washington, D.C., regional offices are also located in Boston, New York, Philadelphia, Atlanta, Chicago, Dallas, Kansas City, Denver, San Francisco, and Seattle. Each office serves a designated area of the country; for instance, the Atlanta office serves Alabama, Florida, Kentucky, Mississippi, North Carolina, South Carolina, and Tennessee as well as Georgia. ACF offers a range of programs, such as those designed to help parents seeking to adopt or to become foster parents and those that provide assistance to physically and mentally disabled persons who need guidance to live independently. Child-related programs include assistance for abandoned children, child abuse and neglect prevention, child care and development, child support enforcement, and child welfare services. Community-related programs include food and nutrition education, family violence prevention, and the Healthy Marriage Initiative. ACF may award grants to communities in crisis and to groups that offer services to children and families. Individuals in need may also receive help directly from ACF to locate job opportunities, obtain funds to pay energy bills, receive temporary financial assistance, or deal with natural disasters. The Head Start program is probably the best known of ACF’s projects. The program was created to promote school readiness among at-risk children through the provision of educational, health, and social services to the child’s family. Grants are awarded to local governments and agencies to develop Head Start programs. Since 1995, the supplementary program, Early Head Start, targets children under the age of three to promote healthier growth and development. Health services are an important element of the Head Start program, and medical and dental exams are regularly scheduled for families enrolled in the program. Whenever further treatment is necessary, Head Start workers are involved in follow-up activities. Childhood immunizations are carefully monitored, and parents and children learn the importance of good nutrition. Other ongoing ACF projects include the FaithBased and Community Initiative, which endeavors to join faith-based groups with others in the community
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Administration on Aging (AoA)
to provide the full benefit of social services to area residents. The Healthy Marriage Initiative is designed to keep families together by teaching couples how to work through problems and build stronger marriages. ACF also works with fathers to help them to recognize the importance of their roles in the lives of their children. Grants are available for communities to create ACF-initiated programs. SEE ALSO: Department of Health and Human Services
(DHHS); Health Resources and Services Administration (HRSA); Indian Health Service (IHS). Bibliography. ACF, “Office of Head Start,” www.acf.hhs.
gov/programs/hsb/ (cited December 2006); DHHS, “Administration for Children and Families,” www.acf.dhhs. gov (cited December 2006); Kenneth J. Meier and Laurence J. O’Toole, Jr., Bureaucracy in a Democratic State: A Government Perspective (Johns Hopkins University Press, 2006); Lorri A. Zipperer, ed., The Health Care Almanac: A Resource Guide to the Medical Field (American Medical Association, 1995). Elizabeth R. Purdy, Ph.D. Independent Scholar
mission of AoA is to allow the elderly to maintain healthy, independent lives as long as possible and to live out their lives in dignity. AoA is also involved in preparing society to deal with America’s aging population. The AoA is led by the Assistant Secretary for Aging who oversees the activities of 10 regional support centers that are geographically organized. AoA’s focus areas are: support, nutrition, prevention, information, and rights protection. Support for individuals may range from performing minor home repairs to furnishing transportation to doctors’ offices or to the grocery store. Since 2000, support for caregivers has been funded through the National Family Caregiver Support Program (NFCSP), which offers counseling, information, and assistance. AoA’s Nutrition Program has served around six billion meals to America’s elderly since its creation. Meals are provided at senior citizens’ centers or delivered directly to homebound individuals. Much of the work of AoA is accomplished with the help of volunteers. AoA’s prevention program focuses on promoting healthy lifestyles that may circumvent chronic diseases and lengthen life spans. Special assistance is offered to Native Americans, Native Ha-
Administration on Aging (AoA) In 2005, around 36.8 million Americans were over the age of 65, comprising some 12.4 percent of the total population. It has been estimated that as the baby boomer generation ages, this population will rise to 71.4 million by 2030, making up a fifth of the total population. Located at One Massachusetts Avenue in Washington, D.C., the Administration on Aging (AoA) operates under the auspices of the Department of Health and Human Services (DHHS) to provide services to elderly Americans, caregivers, and local communities that serve this expanding population. AoA was created and funded through the Older Americans Act of 1965. Direct services include the home-delivery meal program, adult day care, transportation for seniors, nursing care representation, healthcare and promotion, and counseling. Support for families of the disabled or chronically ill is provided through the National Family Caregiver Support Program. The
The AoA serves America’s elderly, who are expected to number 71.4 million, or a fifth of the total population, by 2030.
Adolescent Development
waiians, grandparents who are raising grandchildren, and elderly caregivers of children and adolescents with mental incapacities or developmental difficulties. Activities geared toward protecting the rights of older Americans range from financial counseling to investigations into elder abuse and consumer fraud. Information on elder care is available through AoA’s hotline (800-677-1116) or from the Web site (www.aoa.gov). The Older Americans Act of 1965 also established the National Network on Aging, which is a partnership among national, state, tribal, and local communities. Made up of 56 state units, 655 area units, 233 tribal and native units, and two Hawaiian units, the network has served around seven million seniors and their caregivers since its creation. Most of the network’s clients are the economically disadvantaged, those who are geographically isolated, and those who experience social and health disparities. Other legislation has supplemented the work of AoA and expanded protections for the elderly. For instance, amendments to the Social Security Act established Medicare (Title XVIII) and Medicaid (Title XIX) to provide the elderly with health insurance and financial assistance. In 1967, Congress made it illegal to discriminate on the basis of age. Amendments in 1973 established grants to local communities to establish senior citizens’ centers and to set up an employment program for individuals over 50 years of age. The following year, housing assistance grants for low-income seniors were instituted. In 1987, major nursing home reforms were enacted to protect the health and well-being of the elder population who are unable to live independently. See Also: Department of Health and Human Services
(DHHS); Medicaid; Medicare.
BIBLIOGRAPHY. HHS, “Administration on Aging” http://
www.aoa.gov/; Robert Kutzmman and Katherine Beck, Alzheimer Disease: The Changing View (Academic Press, 2000); Harold C. Relyea and Thomas P. Carr, The Executive Branch: Creation and Organization (Novinka, 2003); Lorri A. Zipperer, ed., The Health Care Almanac: A Resource Guide to the Medical Field (American Medical Association, 1995). Elizabeth R. Purdy, Ph.D. Independent Scholar
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Adolescent Development The term adolescence was coined by the American psychologist and educator Granville Stanley Hall (1842–1924) to describe the transitional period of human development from childhood to adulthood. Hall viewed adolescence as a time of storm and stress, marked by vacillating and contradictory emotions. The anthropologist Margaret Mead (1901–78), who studied growing up in Samoa and other South Pacific islands, claimed that adolescence might be stressful or smooth, depending upon how a particular society responded. Mead concluded that when a culture provides a gradual, serene transition from childhood to adulthood, storm and stress is not typical. Her observation was supported by research in 186 preindustrial societies. Albert Bandura (1915–), a contemporary U.S. psychologist, said adolescence, even in America, is not as stressful as Hall implied. Sigmund Freud (1856–1939), the founder of psychoanalysis, placed adolescents in the genital stage, the stage of mature adult sexuality. This stage is biologically determined and it occurs when reawakened sexual urges are no longer repressed, as they were during the previous latency period. In the genital period, sexual gratification is aimed at developing satisfying heterosexual relationships with people outside the family and in finding a suitable reproductive partner. Physical and Physiological Development Adolescence begins with pubescence, a period of rapid physical growth, maturation of reproductive functioning, and appearance of primary and secondary sexual characteristics. Pubescence lasts about two years and ends with puberty, when sexual maturity and reproductive capacity are complete. Puberty is triggered by hormonal changes. During puberty, both boys and girls undergo an adolescent growth spurt, that is, sudden growth in height, weight, and muscular and skeletal development. Most notable and obvious is the appearance of menarche in females. Males experience nocturnal emissions. The primary sex characteristics are enlargement and maturation of organs directly related to reproduction. The secondary sex characteristics include physiological signs of sexual maturation such as breast development, growth of body hair, and so forth, that do not involve the sex organs. The principle signs
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Adolescent Development today’s higher standards of living, such as improved nutrition and better healthcare.
Research has found both structural and functional changes in adolescents’ information processing.
of sexual maturity are production of sperm (for males) and menstruation (for females). Puberty, which begins earlier in girls than in boys, ends when a person can reproduce. The timing of these events varies considerably both individually and crossnationally. In most societies, puberty is considered to be the end of childhood. The end of adolescence is not clear-cut either. In Western societies, no single sign indicates that adulthood has been attained. In some societies, adolescence ends at puberty and is signified by puberty rites, which take a variety of forms. In contemporary understanding, adolescence is the transition from childhood to adulthood. It lasts from between age 10 and 13 until the late teens or early 20s. In recent decades, people have been reaching sexual maturity sooner, growing faster and bigger than they used to, and attaining adult height earlier. This trend toward larger size and earlier maturation is known as the secular trend. Secular trend is influenced by
Psychosocial Development Independent of culture, an adolescent’s rapid body changes affect his or her self-concept and personality. Particularly important is the effect of early or late maturing, which is pronounced during adolescence but seems to disappear by adulthood. In Erik Erikson’s theory of life-span development, the fifth crisis involves the adolescent’s search for identity, or role confusion. The most important task for the adolescent is this search for identity, which can occur in many ways: by developing one’s values, by developing pride in one’s achievements, and by developing close relationships with peers. Career choice is usually viewed as an important step in identity formation. Erikson believed that teens who have successfully resolved the conflicts of the earlier four stages are much better equipped to resist peer pressure and find their own identity during adolescent years. Those teens who are not as successful come into the adolescent years with a lack of trust in others, feelings of guilt and shame, low self-esteem, and dependency on others. Peer pressure is quite effective on teenagers who desperately want to “fit in” and have an identity of some sort and who feel that others will not want to be with them unless they conform to the expectations and demands of the peer group. They play the part of the model child for the parents, the good student for the teachers, and the “cool” juvenile delinquent to their friends and will be confused about which of the many roles they play is really their own identity. Cognitive and Moral Development Research has found both structural and functional changes in adolescents’ information processing. Structural changes include increases in declarative, procedural, and conceptual knowledge and expansion of the capacity of working memory. Functional changes include progress in deductive reasoning and thinking. Because of emotional immaturity, adolescents might make poor decisions. A new stage of development is being conceptualized—that of youth, a stage that bridges the transition between adolescence and adulthood. This stage is more like a waiting period in which the youth is ostensibly preparing for adult responsibilities, which require the maturation of emotions.
According to Lawrence Kohlberg (1927–87), moral reasoning is based on a developing sense of justice and growing cognitive abilities. Kohlberg has proposed that moral development progresses from external control to internalized societal standards and personal moral codes. Kohlberg’s theory holds that moral reasoning, which he thought to be the basis for ethical behavior, has developmental stages. Adolescents, especially those who receive a formal high school education, move into a stage of thinking that the Swiss psychologist Jean Piaget (1896–1980) named the stage of formal operations in which abstract thinking becomes possible. This cognitive advance is primarily due to the final development of frontal lobes of the brain, the part of the brain that is responsible for organizing, understanding, and decision making. Teenagers begin to think about hypothetical situations, leading to a picture of what an ideal world would be like. Many become convinced that such a world would be attainable if only everyone else would listen to and follow the teenager. Vocabulary and other aspects of language development, especially those related to abstract thought, such as social perspective taking, also improve in late adolescence and youth. This leads adolescents to word play and creating their own “dialects.” Even with all the difficulties of establishing a personal, sexual, social, and vocational identity, adolescence is typically a positive threshold to adulthood. SEE ALSO: Adolescent Health; Child Development. BIBLIOGRAPHY. A. Bandura, Social Fundamentals of
Thought and Action (Prentice-Hall, 1986); Anne Colby, et al., The Measurement of Moral Judgment (Cambridge University Press, 1987); Erik Erikson, Identity: Youth and Crisis (Norton, 1968); Sigmund Freud, A General Introduction to Psychoanalysis, J. Riviere, trans. (Permabooks, 1953); Andrew Garrod, ed., Approaches to Moral Development: New Research and Emerging Themes (Teachers College Press, 1993); G.S. Hall, Adolescence (Appleton, 1916); S. Jeshmaridian, “Youth & Education in Transition Society of Armenia,” in A. Avetisyan, ed., The Education in Armenia in Transition Period (Yerevan State University Press, 1999); Lawrence Kohlberg, Child Psychology and Childhood Education: A Cognitive-Developmental View (Longman, 1987); Margaret Mead, Male and Female (Morrow, 1949); Margaret Mead, Culture and Commitment: A Study of Generation Gap (Natural History/Doubleday, 1970); Jean Piaget,
Adolescent Health
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The Origin of Intelligence in Children (Norton, 1952); A. Schlegel and H. Barry, Adolescence: An Anthropological Inquiry (Free Press, 1991). Samvel Jeshmaridian, Ph.D. American Psychological Association
Adolescent Health In most modern societies, no single event or ceremony marks the passage from childhood to adulthood. Rather, we experience an extended transition period linking childhood and adulthood known as adolescence. Although adolescence has been traditionally defined as the “teens,” from age 13 to 19, it is not necessarily determined by chronological age. The secular trend, or the tendency of one generation to begin puberty at an earlier age than their parents due to better nutrition and healthcare, began about 100 years ago but seems to be leveling off. For instance, in the late 1980s, it appeared to level off in Europe and North America. An adolescent is no longer physically a child, but is not yet an independent, self-supporting adult. Early adolescence is full of opportunities for cognitive, physical, and psychosocial development, but also of risks to healthy development. Dramatic physiological changes mark adolescence. The reproductive organs enlarge and mature and secondary sex characteristics appear. For the most part, the adolescent years are relatively healthy. Health problems are often associated with poverty and lifestyle. Adolescence also concerns how a person deals with life issues such as work, family, and relationships. Although many adolescents can think and solve problems in an adult manner, much of their thought and behavior continues to be somewhat childish and contradictory. For instance, although adolescents may think about death in the abstract, they frequently engage in high-risk behaviors, such as taking drugs, driving fast, or becoming gang members. The adolescent brain is not yet fully mature. It undergoes a second wave of overproduction of gray matter, especially in the frontal lobes, followed by pruning of excess nerve cells. Continuing myelination of the frontal lobes facilitates the maturation of cognitive processing. Adolescents process information about
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Adolescent Health
emotions with the amygdala, whereas adults use the frontal lobe. Thus, adolescents tend to make less accurate and reasoned judgments. Underdevelopment of frontal cortical systems connected with motivation, impulsivity, and addiction may help explain adolescents’ tendency toward risk taking. Physical health in adolescence can be affected by the lack of regular vigorous physical activity in most societies of the contemporary world. Also, many adolescents do not get enough sleep because the high school schedule is out of sync with their natural body rhythms. Concern with body image, especially among girls, may lead to eating disorders. Three common eating disorders in adolescence are obesity or overweight, anorexia nervosa (eating disorder characterized by self-starvation), and bulimia nervosa (eating disorder in which a person regularly eats huge quantities of food and then purges the body by laxatives, induced vomiting, fasting, or excessive exercise). All can have serious long-term effects. Anorexia and bulimia affect mostly girls. Outcomes for bulimia tend to be less drastic than for anorexia. In the United States, adolescent substance use has decreased in recent years. Still, drug use often begins as children move into middle school. Marijuana, alcohol, and tobacco are the most popular drugs with adolescents. All involve serious risks. Marijuana use can lead to the use of hard drugs. Although most young people experience no major health problems, as a rule, risky behavior patterns, such as drinking alcohol, drug abuse, sexual activity, gang membership, and use of firearms, tend to increase throughout the teenage years. Mental Health The age at which puberty begins has implications for the way adolescents feel about themselves as well as the way others treat them. Early maturing boys have a distinct advantage over later maturing boys. They do better in athletics, are generally more popular with peers, and have more positive self-concept. The picture differs for girls. Although early maturing girls are more sought after as dates and have better self-esteem than do late maturing girls, some consequences of early physical maturation may be less positive. For example, early breast development may set them apart from their peers and be a source of ridicule. Late physical maturation may produce certain psychological difficulties for both boys and girls. Boys who
are smaller and less coordinated than their more mature peers tend to feel ridiculed and less attractive. Similarly, late maturing girls are at a disadvantage in middle school and early high school. They hold relatively low social status and may be overlooked in dating. Depression in adolescents does not necessarily appear as sadness but as irritability, boredom, or inability to experience pleasure. It needs to be taken seriously because of the danger of suicide. The risk factors for adolescent depression are anxiety, fear of social contact, stressful life events, female gender, chronic illness such as diabetes or epilepsy, parent–child conflict, abuse or neglect, and having a parent with a history of depression. Body image and eating disturbances can aggravate depressive symptoms. Depressed adolescents who do not respond to outpatient treatment or who have substance dependence or psychosis or seem suicidal may need to be hospitalized. Short-term cognitive behavioral therapy can be effective. In this type of therapy, patients learn to choose pleasurable activities, improve social skills, and modify self-defeating ways of thinking that can lead to depression. Selective serotonin reuptake inhibitors (SSRIs), a type of antidepressant medication, are the most common treatment for adolescent depression, and their rapidly increasing use since the mid-1990s has been accompanied by a modest reduction in suicide rates. Leading causes of death among adolescents include motor vehicle accidents, firearm use, and suicide. In the United States, a teenager commits suicide every 90 minutes—a rate that has tripled over the last two decades. Male adolescents are five times more likely to commit suicide than are females, although females attempt suicide more often than males do. The rate of adolescent suicide is significantly greater among whites than among nonwhites. The suicide rate of African-American males has increased much more rapidly than has that of white males over the last two decades. Native Americans have the highest suicide rate of any ethnic group in the United States, and Asian Americans have the lowest rate. It is not clear why suicide has increased so dramatically over the last few decades. Some psychologists suggest that the sharp rise in stress that teenagers experience—in terms of academic and social pressure, alcoholism, drug abuse, and family difficulties—provokes the most troubled adolescents to
take their own lives. The most influential factors in adolescent suicide are considered depression and a deep sense of hopelessness. Morality Measurement and Moral Health After becoming fascinated with children’s reactions to moral dilemmas, Lawrence Kohlberg developed his stages of moral development to explain the development of moral reasoning. Kohlberg’s theory holds that moral reasoning, which he thought to be the basis for ethical behavior, has six identifiable developmental stages. Kohlberg’s stages are broken into three different levels: preconventional, conventional, and postconventional. According to his model, it is not possible to regress backward in stages. It is also not possible to “jump” stages; each stage provides new perspective and is “more comprehensive, differentiated, and integrated than its predecessors.” Level one, or the precconventional level of moral reasoning, is especially common in children, although adults can also exhibit this level of reasoning. Reasoners in the preconventional level judge the morality of an action by its direct consequences. The preconventional level consists of the first and second stage of moral development. In stage one—obedience and punishment orientation—adolescents focus on the direct consequences that their actions will have for themselves. For example, they think that an action is morally wrong if the person who commits it gets punished. Stage two—self-interest orientation—espouses the what’s-in-it-for-me position: right behavior being defined by what is in one’s own best interest. Stage two reasoning shows some limited interest in the needs of others, but only to a point where it might further one’s own interests, such as “you scratch my back, and I’ll scratch yours.” Concern for others is not based on loyalty or intrinsic respect in stage two. The conventional level of moral reasoning, or level two, is typical of adolescents and adults. People who reason in a conventional way judge the morality of actions by comparing these actions to social rules and expectations. The conventional level consists of stages three and four of moral development. In stage three—social contract orientation—individuals are receptive of approval or disapproval from other people. They try to be a good boy or good girl, having learned that there is inherent value in doing so. Stage
Adolescent Health
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three reasoning may judge the morality of an action by evaluating its consequences in terms of a person’s relationships. For stage four—universal ethical principles and principled conscience—it is important to obey laws and social conventions because they maintain a working society. Moral reasoning in stage four advances beyond the need for approval exhibited in stage three, because the individual understands that society needs to transcend individual needs. Level three, or the postconventional level, consists of stages five and six of moral development. In stage five, people have certain principles to which they may attach more value than laws, such as human rights or social justice. In this reasoning, actions are wrong if they violate these ethical principles. Laws are regarded as social contracts rather than dictums, and must be changed when necessary (provided there is agreement). By this reasoning, laws that do not promote general social welfare should be changed. Democratic governments are ostensibly based on stage five reasoning. In stage six, moral reasoning is based on the use of abstract reasoning using universal ethical principles. One way to do this is by imagining oneself in everyone else’s shoes, imagining what they would decide if they were doing the same. While Kohlberg insists that stage six exists, he has difficulty finding participants who use it. It appears that people rarely, if ever, reach stage six of Kohlberg’s model. Psychosocial Problems The search for identity is closely linked to vocational choice, which is related to and influenced by socioeconomic status, sex, parental attitudes, schooling, and personality. Erik Erikson described the psychosocial conflict of adolescence as identity versus identity or role confusion. The “virtue” that should arise from this conflict is fidelity. Identity search occurs in a few ways: by developing one’s values, by developing pride in one’s achievements, and by developing close relationships with peers. Teenagers are highly influenced by the peer group. They strongly identify with others in this group and tend to do what their crowd does. Teenagers identify with other teenagers rather than people of their own race, religion, community, or sex. And they consider themselves more idealistic, less materialistic, healthier in their sexuality, and better able to understand friendship and the important things in life than are members of the older generation.
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Adolescent Health
Adolescent sexual experiences have repercussions on budding identity. Many conflicts between parents and adolescent children focus on sexuality. Current sexual attitudes are more liberal than in the past. In Western cultures, most males do not lose respect for females who have intercourse before marriage, and most members of both sexes approve of living together before marriage. Still, males tend to be more sexually active. Adolescent problems include drug abuse, school dropout, juvenile delinquency, and sexual problems such as venereal disease and unwanted pregnancy. James Marcia, in research based on Erikson’s theory, has described four identity statuses: identity achievement, foreclosure, moratorium, and identity diffusion. These four categories differ from each other according to presence or absence of crisis or commitment, the two elements Erikson saw as crucial to forming identity. Marcia defined crisis as a period of conscious decision making and commitment as a personal investment in an occupation or systems of beliefs or ideology. He found relationships between identity status and such characteristics as anxiety, self-esteem, moral reasoning, and patterns of behavior. Building on Marcia’s theory, other researchers have identified additional personality and family variables related to identity status. Sexuality, Pregnancy and Sexually Transmitted Diseases Sexual orientation appears to be influenced by an interaction of biological and environmental factors and to be at least partly genetic. The course of homosexual identity and relationship development may vary from cohort, gender, and ethnicity. Sexual attraction seems to begin at about age 10, when the adrenal glands increase their hormonal output. Although teenage sexual activity nowadays is more prevalent than in the past, it still involves risks of pregnancy and sexually transmitted diseases. Adolescents at greatest risk are those who begin sexual activity early, have multiple partners, do not use contraceptives, and are ill-informed about sex. In Western contemporary societies, it is thought that regular condom use is the best safeguard for sexually active teens. Comprehensive sex education programs delay sexual initiation and encourage contraceptive use. Sexually transmitted diseases are those that spread by sexual contact. Sexually transmitted diseases include chlamydia, trichoniasis, gonorrhea, human pap-
illomavirus (HPV) (genital warts), herpes, hepatitis B, syphilis, and human immunodeficiency virus (HIV) or AIDS. Sexually transmitted diseases can be transmitted by oral sex as well as intercourse. They are more likely to develop undetected in girls than in boys. Rates of sexually transmitted diseases in the United States are among the highest in the industrialized world. The decision to become sexually active represents a major personal commitment that has important consequences. Nowhere is the importance of this decision more clearly seen than in the case of teenage pregnancy in the United States. The teenage pregnancy rate in the United States is more than 90 pregnancies per 1,000 girls, and that rate is over double the rate for Great Britain, Canada, France, Australia, and Sweden. Teenage pregnancy and birthrates in the United States have declined in the last decade. Teenage childbearing often has negative outcomes. Teenage mothers and their families tend to suffer ill health and financial hardship, and the children often suffer from ineffective parenting. Birth rates for 15- to 19-year-old girls in the United States fell by one-third between 1991 and 2003 to 41.7 births per 1,000 girls in that age group, the lowest rate in more than 60 years. Birthrates for unmarried teenagers, who bear about 81 percent of all babies born to adolescent mothers, also have declined since 1994, especially among younger teens. The vast majority (88 percent) of births to teenagers aged 17 and younger result from unintended pregnancies. Effective procedures for encouraging teenagers not to be sexually active include teaching teenagers to understand the problems of sexual activity. SEE ALSO: Adolescent Development; Psychotherapy; Sex-
ually Transmitted Diseases; Teenage Pregnancy.
BIBLIOGRAPHY. T. Anderson and D. Magnusson, “Bio-
logical Maturation in Adolescence and the Development of Drinking Habits and Alcohol Abuse among Young Males. A Prospective Longitudinal Study,” Journal of Youth and Adolescence (v.19, 1990); A. Bandura, Social Fundamentals of Thought and Action (Prentice-Hall, 1986); D.A. Brent and B. Brimaher, “Adolescent Depression,” New England Journal of Medicine (v.347, 2002); Anne Colby, et al., The Measurement of Moral Judgment (Cambridge University Press, 1987); E. Erikson, Identity: Youth and Crisis (Norton, 1968); S. Freud, A General Introduction to Psychoanalysis, J. Riviere, trans.
Adoption Medicine
(Permabooks, 1953); Andrew Garrod, ed., Approaches to Moral Development: New Research and Emerging Themes (Teachers College Press, 1993); G.S. Hall, Adolescence (Appleton, 1916); N.J. Hopwood, et al., “The Onset of Human Puberty: Biological and Environmental Factors,” in J. Bancroft and J.M. Reinisch, eds., Adolescence and Puberty (Oxford University Press, 1990); L. Kohlberg, Essays on Moral Development: Vol. 1. The Philosophy of Moral Development (Harper & Row, 1981); L. Kohlberg, Essays on Moral Development: Vol. 2. The Psychology of Moral Development (Harper & Row, 1984); L. Kohlberg, Child Psychology and Childhood Education: A Cognitive-Developmental View (Longman, 1987); J.E. Marcia, “Identity in Adolescence,” in J. Adelson, ed., Handbook of Adolescent Psychology (Wiley, 1980); M. Mead, Male and Female (Morrow, 1949); M. Mead, Culture and Commitment: A Study of Generation Gap (Natural History/Doubleday, 1970); National Institute of Mental Health, “Suicide Facts,” www.ninh.nih.gov (cited February 2007); J. Piaget, The Origin of Intelligence in Children (Norton, 1952); A. Schlegel and H. Barry, Adolescence: An Anthropological Inquiry (Free Press, 1991). Samvel Jeshmaridian, Ph.D. American Psychological Association
Adoption Medicine Adoption medicine is a field of medicine concerned with the care and anxieties of families and children involved in international adoptions. A multidisciplinary team of physicians works with the adopting parents before, during, and after the adoption process, helping them understand the unique risks children from their particular adoption area face. Doctors from the fields of pediatrics, psychology, infectious diseases, rehabilitation therapy, and behavioral/developmental medicine review the adopted child’s dossier before the adoption process takes place. These professionals advise the new parents of what questions to ask, such as family history, the health of the child’s siblings, the course of the mother’s pregnancy, and birth of the child. With answers to these questions, the parents and physicians are better able to predict what future medical and emotional care the child will need, and what problems may be expected. This team also works with the family after adoption,
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examining the child and setting baseline standards for future growth and development. There are unique medical problems the child may face in transitioning between his or her native home and his or her new one. Certain diseases are more common in specific geographical areas. In China, some intestinal parasites are more common, such as ascaris, giardia, and scabies. Impetigo is more common in orphanages than in cleaner, less crowded facilities. Human immunodeficiency virus (HIV) is seen in Romania, Haiti, and Uganda. Syphilis is common in any country where infants may be abandoned. Depending on the condition of the mother during her pregnancy, fetal alcohol syndrome may be a risk, as are other developmental delays. In general, it is felt that for every three months that a child spends in an orphanage, there may be a one-month developmental delay. The child of a birth mother infected with hepatitis B (HBV) can be a chronic carrier. Higher risk exists for all common forms of hepatitis—hepatitis A (HAV), HBV, and hepatitis C (HCV). In some countries, there is a greater risk that the proper immunization and vaccination schedule has not been followed, leading to infections with childhood illnesses that are not a problem in more-developed countries. There are also malnutrition issues to be considered, as well as attachment problems. Metabolic problems, such as G6PD deficiency and thyroid diseases, may also be more common. Not all children adopted from international countries will be sick or needing greater medical attention in their future. However, because of their origin location, most are at a higher risk of some disorders. In the first year of life, it is normal for any child to be sick with coughs, colds, and other minor illnesses from eight to 12 times. The stress on the adopting family from these normal exposures to new environments may be higher in adoption situations. Information about the child’s initial health can help ease the stress of these normal childhood experiences. This is why adoption medicine is becoming more critical in helping families attain successful, healthy adoptions. SEE ALSO: Child Development; Childhood Immunization;
Pediatrics; Third World.
Bibliography. Laurie C. Miller, The Handbook of In-
ternational Adoption Medicine: A Guide for Physicians, Parents, and Providers (Oxford University Press, 2004);
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Adrenocortical Carcinoma
Wolkind Stephen, Klaus Marshall, Press Mac Keith, Medical Aspects of Adoption and Foster Care, (Cambridge University Press, 1993). Caroline Sebley, O.M.S. II Kansas City University of Medicine and Biosciences Tyler Cymet, D.O. Johns Hopkins School of Medicine
Adrenocortical Carcinoma While adrenocortical masses are common and occur in up to 15 percent of the adult population, adrenocortical carcinomas (ACs) are much less frequent. In fact, an international estimate of ACs is only one per million each year. However, it is currently not known why the incidence is approximately 10 times higher in southern Brazil. While there is no racial predilection toward this disease, it occurs in females approximately three times more frequently than in males. One of the more common classification schemes for adrenocortical carcinomas is the functional and nonfunctional distinction. Functional tumors are classified by the type of hormone that the tissue produces, that is, glucocorticoids, mineralocorticoids, androgens, estrogens, and/or other peptides. There is generally a bimodal age distribution with functional carcinomas: early childhood and in the fourth to fifth decades of their lives. Nonfunctional carcinomas are more common in adults. Adrenocortical tumors have been linked to several hereditary cancer syndromes, including Gardner syndrome, Beckwith-Wiedmann syndrome, multiple endocrine neoplasia type 1 (MEN 1), the SBLA (sarcoma, breast, lung, and adrenocortical cancer) syndrome, familial polyposis coli, Turcot syndrome, Cowden syndrome, and the Li-Fraumeni syndrome. The cause of these syndromes is not yet known, although it has been proposed that tumor suppressor gene (TP53 and TP57 genes) mutations and adrenal hyperplasia may predispose an individual to ACs. Proto-oncogenes and defects in apoptosis may also regulate AC development. Individuals with adrenocortical carcinomas may note symptoms directly related to the tumor mass
itself or may suffer from excessive hormonal production. Nonfunctional tumors may be associated with abdominal pain, back pain, abdominal fullness, and weight loss. In addition to these symptoms, the individual may also have symptoms related to his or her particular endocrine abnormality. This may include the following: • Cushing’s syndrome • Virilization syndromes: virilization in girls, precocious puberty in boys • Hirsutism, facial acne, oligomenorrhea, or amenorrhea • Feminization • Primary hyperaldosteronism • Hypertension • Polycythemia • Hypercalcemia • Hypoglycemia • Insulin resistance • Catecholamine excess If an adrenocortical tumor is suspected, computed tomography (CT) scanning or magnetic resonance imaging (MRI) are the initial imaging studies of choice. The classic image of an AC on CT scans is a unilateral mass with irregular borders. MRIs are particularly useful for differentiating adrenocortical carcinomas from nonfunctional adenomas and pheochromocytomas. Ultrasounds are less useful for detection but can be used to follow adrenal incidentalomas. It is also important to test for abnormal hormone production. Dexamethasone suppression tests and 24-hour urinary cortisol excretion tests can be used to screen for Cushing syndrome. Hyperaldosteronism can be evaluated by measuring aldosterone and renin levels. Individuals should also be tested for levels of adrenal androgens and plasma estradiol to screen for virilization syndromes and feminization syndromes, respectively. Urinary catecholamines may also be tested as well as to rule out a pheochromocytoma. Once the presence of an adrenocortical carcinoma has been established, the stage of the tumor must be established to guide treatment. Staging for ACs is commonly based upon the Sullivan scale which takes into consideration tumor size, the involvement of lymph nodes, and the presence of metastases. Treatments include chemotherapeutic drugs, radiation therapy, and surgical treatments. The primary drug for ACs is mitotane, which causes adrenal inhibition.
Adult Congenital Heart Association (ACHA)
Other medications include suramin, gossypol, and cisplatin-based chemotherapy. There also exist medications to treat endocrine excess. Radiation therapy is aimed at palliation of local disease but has not been shown to treat the primary disease process. Surgical management, however, is the definitive management of adrenocortical adenomas and carcinomas. Surgery is almost always curative for adenomas and provides the best possibility for carcinomas. Patients with functional AC have a better prognosis than those with nonfunctional AC. The overall five-year survival rate for patients with any type of AC is 20 to 35 percent. If surgical resection is possible, this rate increases to 32 to 47 percent; however, relapse is common and occurs in approximately 80 percent of patients. SEE ALSO: Cancer (General). BIBLIOGRAPHY. B. Allolio, et al., “Management of Adreno-
cortical Carcinoma,” Clinical Endocrinology (v.60/3, 2004); S.R. Bornstein, C.A. Stratakis, and C.P. Chrousos, “Adrenocortical Tumors: Recent Advances in Basic Concepts and Clinical Management,” Annals of Internal Medicine (v.130/9, 1999); M. Boscaro, et al., “Adrenocortical Carcinoma: Epidemiology and Natural History,” Minerva Endocrinologica (v.20/1, 1995); M.E. Lockhart, J.K. Smith, and P.J. Kenney, “Imaging of Adrenal Masses,” European Journal of Radiology (v.41/2, 2002); L. Ng and J.M. Libertino, “Adrenocortical Carcinoma: Diagnosis, Evaluation and Treatment,” Journal of Urology (v.169, 2003); X.R. Xiao, et al., “Diagnosis and Treatment of Adrenal Tumours: A Review of 35 Years’ Experience,” British Journal of Urology (v.82, 1998).
promotion of medical research. The ACHA provides a wide range of resources to its members, and to anyone interested in learning more about heart defects. One of the group’s central goals involves educating the general public on the nature of congenital heart defects and the fact that today more and more individuals have the ability to live longer, and with a higher quality of life, with heart defects and related problems. While the group does not endorse or certify specific clinics, it maintains a list of clinics worldwide that specialize in the treatment of congenital heart defects. The organization also maintains an extensive list of state, regional, national, and international support groups. Four times a year the ACHA publishes a newsletter, Heart Matters, that includes a great deal of medical and nonmedical information related to the heart. According to the ACHA, as many as one million adults in the United States suffer from various congenital heart defects, and many of those afflicted require ongoing care. Estimates indicate that the number of adults with congenital heart defects will likely increase by as much as 5 percent each year due to improvements in medical science. As a result, while congenital heart defects remain one of the most common birth defects, there are and will continue to be more adults than children living with the problem. One of the goals of the ACHA is to ensure that the
Darrin Lee University of California, Irvine
Adult Congenital Heart Association (ACHA) Incorporated in 1998 and with offices in Philadelphia, Pennsylvania, the Adult Congenital Heart Association (ACHA) is a nonprofit organization dedicated to helping prolong and improve the lives of adults with congenital heart defects. The group accomplishes its goals through education, outreach, advocacy, and the
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As many as one million adults in the United States suffer from various congenital heart defects.
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Adult Immunization
quality care usually provided to infants with heart defects carries over to this growing adult population. The ACHA is governed by a 13-member board of directors and many top U.S. specialists in congenital heart defects sit on the group’s medical advisory board. The organization sponsors regional conferences and an annual national conference as well as ongoing fund-raising and lobbying efforts. In February 2006, the ACHA, the Children’s Heart Foundation, and the Congenital Heart Information Network sponsored the first National Congenital Heart Lobby Day in Washington, D.C., with the goal of convincing Congress to appropriate funds for research. The ACHA also sponsors the Karen McNulty Scholarship Fund, named for one of the organization’s cofounders and designed to help those who might not possess the means to attend the ACHA’s national meetings. Among groups that endorse the work of the ACHA are the American Heart Association, the American College of Cardiology, and the American Academy of Pediatrics. See Also: Birth Defects; Heart Diseases (General); Heart
Diseases—Prevention.
BIBLIOGRAPHY. The Adult Congenital Heart Associa-
tion, www.achaheart.org (cited June 2006); Alice Dembner, “Childhood Heart Defects Cause Trouble in Later Years,” Boston Globe (September 26, 2005); Michael Gatzoulis, et al., Adult Congenital Heart Disease: A Practical Guide (BMJ Publishing Group, 2005); Welton M. Gersony and Marlon S. Rosenbaum, Congenital Heart Disease in the Adult (McGraw Hill Professional Publishing, 2001); L.A. Rhodes, et al. “The Adult with Congenital Heart Disease,” West Virginia Medical Journal (v. 102/1, 2006). Ben Wynne, Ph.D. Gainesville State College
Adult Immunization Immunizations are defined as the process that occurs when an individual is exposed to an agent specifically designed to increase the immune system response against that agent. Inoculation and vaccination describe a similar action as immunization in that both
use a viable infecting agent to increase the immune system’s protective response. Immunization is the general term used to describe vaccination. Immunizations are an important component of public health around the world and have been recognized as one of the most important human achievements in the history of medicine for improving health. In 2002 immunizations are attributed with preventing an estimated 2 million deaths. Providing immunizations for adults has been shown to prevent infection, illness, and death. Immunizations of adults is a proven tool for managing and eradicating disease. The most successful use of immunizations to prevent illness on a global scale was in the eradication of smallpox. Smallpox threatened more than 60 percent of the world’s population, killing 25 percent of those infected. Smallpox was responsible for an estimated 300–500 million deaths worldwide in the 20th century. A British doctor, Edward Jenner, known as the inventor of the modern immunization process, noticed that the smallpox virus resembled the harmless cowpox virus. He found that by injecting a human with the cowpox virus, the person became immune to smallpox. Eventually, through a worldwide campaign against smallpox, the disease was declared successfully eradicated in 1979 by the World Health Organization (WHO). Other worldwide campaigns to control and prevent the spread of disease through immunizations include poliomyelitis and tetanus. While childhood vaccinations are often placed at the forefront of immunization efforts, the role of adult immunizations should not be underestimated. In some cases, vaccine-preventable diseases that present as mild in children can be severe diseases in adults. This is especially true for mumps, chickenpox, and rubella. In addition to adults who are not immunized against preventable diseases, it is also important to remember that there are several other reasons why immunization initiatives should focus on all adults and not just nonimmunized ones. In particular, it should not be assumed that all adults were immunized as children. Furthermore, adults who were immunized as children may not have benefited from newer vaccines that may have recently been developed with higher levels of protection. Adult immunizations are particularly important for preventing morbidity and mortality. Adults often have unique risk factors, and the elderly are also
Aerospace Medicine
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WHO and other international aid organizations that are currently at the forefront of immunization initiatives for children and adults throughout the world continue to lead the fight against preventable infectious diseases through expansions of immunization programs. SEE ALSO: Bird Flu; Childhood Vaccination; Disease Pre-
vention; Drug Industry (Worldwide); Infectious Disease (General); Immunization/Vaccination; National Immunization Program (NIP); National Network for Immunization Information (NNii). BIBLIOGRAPHY. American College of Physicians Task
Force, Guide for Adult Immunization (American College of Physicians, 1994); Barry R. Bloom and Paul-Henri Lambert, The Vaccine Book (Academic Press, 2002); Stanley A. Plotkin, Walter A. Orenstein, and Paul A. Offit, Vaccines (Saunders, 2003). Jonathan Tan, M.P.H. SUNY Stony Brook School of Medicine Immunizations are believed to have prevented an estimated 2 million deaths worldwide in 2002 alone.
more likely to be immune compromised. Vaccines needed by adults include the hepatitis A and B vaccine, measles-mumps-rubella (MMR) vaccine, meningococcal vaccine, tetanus-diphtheria vaccine, chickenpox vaccine, and the human papillomavirus (HPV) vaccine. For those over the age of 50, it is recommended that the flu vaccine be used each year. For individuals above 65 years of age, the pneumococcal vaccine is recommended. A current debate on the international level challenges the commitment of the world to eradicating diseases that are known to be preventable through the use of immunizations. Immunizations have been proven to offer a cost-effective intervention to prevent diseases because they usually only require a one-time visit with almost none of the difficult behavioral changes required for other interventions to be successful. Still, an estimated 2.1 million people around the world have died recently from diseases preventable by the use of vaccines.
Aerospace Medicine Aerospace medicine is a branch of preventive medicine, or occupational medicine, concerned with the health and safety of aircrew and passengers exposed to the aerospace environment. Practitioners and researchers apply principles of atmospheric physics and environmental physiology in assessing an individual’s fitness for flight, and develop aviation hardware to maximize aircrew and passenger safety. The aerospace environment may involve abrupt or prolonged exposure to altered atmospheric pressure, enhanced or reduced gravitational forces (g-forces, or Gz), or extreme low temperatures. Any of these, in addition to human factors, may pose serious threats to astronauts, pilots, aircrew, passengers, or patients during aero-medical transport. With increasing altitude, atmospheric pressure and temperature lose compatibility with normal homeostasis. Although the fraction of atmospheric oxygen does not change with altitude, its partial pressure (PO2) decreases in proportion to the overall decline in barometric pressure (Dalton’s Law). In the event
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Afghanistan
of a sudden loss of cabin pressure aircrew and passengers are exposed to rapid decompression, which constitutes a medical emergency. At higher cruising altitudes (≥30,000 feet), such a hypobaric environment renders the venous PO2 greater than the ambient PO2 and oxygen diffusion in the lungs is reversed. This serious hypoxic environment calls for the use of oxygen masks by aircrew and passengers and a rapid descent to lower altitudes. When decompression does not necessarily involve a severe hypoxic environment, patients and/or aircrew may experience decompression sickness (DCS) during a transition to a lower atmospheric pressure. DCS is caused by soluble nitrogen trapped in the tissues that expands into bubbles as atmospheric pressure is decreased. Stiff, painful joints are diagnostic of DCS (referred to as the bends), while vascular and nervous tissue may also be affected. Commonly understood among SCUBA divers, DCS is also encountered in the aerospace environment. Astronauts and pilots of high performance aircraft experience varied gravitational forces that may have adverse medical consequences. Positively enhanced gravitational forces are experienced by high-performance pilots during rapid acceleration and tend to cause pooling of blood in the lower extremities. Such blood shifting can lead to diminished cerebral perfusion and cerebral hypoxia at higher positive forces. This often results in episodes of syncope referred to as gravitationally induced loss of consciousness (GLOC). In contrast to these effects of enhanced gravitational forces, astronauts experience prolonged exposure to microgravity. Such prolonged exposure leads to changes in autonomic cardiovascular regulation, as well as altered skeletal muscle metabolism. Return to Earth’s +1 Gz field may result in orthostatic symptoms such as postural tachycardia, and general orthostatic intolerance, while skeletal muscle is atrophied. Civilian aerospace practitioners are referred to as aviation medical examiners (AME), while military practitioners are called flight surgeons. Both civilian and military practitioners perform aeromedical examinations to evaluate aircrew safety. AMEs are designated by the Federal Aviation Administration (FAA) and are tasked with screening aircrew for medical conditions that may compromise in-flight safety. The examination involves screening for conditions such as risk for myocardial infarction, epilepsy, color
blindness, diabetes, and any other possible source of incapacitation. Upon assurance of safety, AMEs issue Airman Medical Certificates. Despite the fact that aerospace medicine is considered its own boarded medical specialty, familiarity with medical problems in relation to the aerospace environment is essential to the practicing emergency physician. Emergency physicians are required to evaluate a patient’s fitness for aeromedical transport, as well as to prepare them safely for flight. See Also: Occupational Health; Occupational Injuries;
Occupational Medicine.
BIBLIOGRAPHY. R.L. DeHart, ed., Fundamentals of Aero-
space Medicine, 2nd ed. (Williams & Wilkins, 1996); John Ogle, “Aerospace Medicine,” www.eMedicine.com (cited August 2006). Phillip C. Usera The Medical School for International Health, Israel
Afghanistan Afghanistan is located in southern Asia, bordered on the west by Iran and the east by Pakistan. With an area of only 647,500 square miles, this small nation has some of the most rugged terrain in the world, ranging from the high mountains of the Hindu Kush to the arid, windswept plains in the north and the southwest. More than 25 years of war has left Afghanistan’s 31 million citizens with one of the worst health profiles on the planet. Life expectancy at birth is just 43 years. Only 2 percent of the population is over 65. Infant mortality is 160 per 1,000 live births. One in four children die before the age of 5. Despite millions of dollars in international aid, the dozens of nongovernmental organizations that have flooded into the country since the fall of the Taliban in 2003 have barely been able to make a dent in the major health problems facing Afghans today. In many cases, they are not able to even reach the population that needs them most—the 80 percent of Afghans who live outside the few major cities. It is simply too dangerous and too difficult to move around outside
More women die in childbirth in Afghanistan than almost anywhere else in the world, and 87 percent of these deaths are preventable.
these cities. There is no national network of clinics and hospitals, and there is no safe way to transport the sick to population centers for care. Most Afghans suffer from inadequate sanitation and nutrition, falling prey to preventable waterborne illnesses such as hepatitis A, typhoid fever, and diarrhea. Communicable diseases such as measles, polio, and tuberculosis are rampant; leprosy exists in some areas. Malaria is common during the summer outside the mountains. Afghans also have to cope with a variety of natural and man-made hazards. Earthquakes are common in the mountains, as are floods and drought. Sporadic tribal warfare and insurgency continue throughout the region. In 1996, it was estimated that there were more than 10 million landmines and other pieces of unexploded ordinance. It is not known how many people lose lives or limbs to forgotten landmines each year. Women continue to suffer from inadequate healthcare at a disproportionate rate. Afghan women marry very young and begin childbearing as soon as physically possible. They suffer from high rates of anemia and
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malnutrition. Spousal abuse is rampant and tolerated by society. Since 2003, there have been several cases of self-immolation, where desperate women commit suicide by setting themselves on fire. Although gathering statistics has proven difficult given the closed nature of Afghan society, one 2002 report estimated maternal mortality at 1,600 deaths per 100,000 live births. More women die in childbirth in Afghanistan that almost anywhere in the world, and the death rates in the Badakshan region were the highest ever documented. The most common cause of death in childbirth was hemorrhage. The same study found that 87 percent of these deaths were preventable. However, this would require the removal of barriers on several levels: educating women about the risks of pregnancy so they would know when they were in danger; bringing health resources to the most remote areas of the country; and ensuring that even remote healthcare facilities could care for crisis births in a sanitary manner. While there has been significant progress in these areas, the childbearing years remain a dangerous time for the majority of Afghan women. Maternal mortality, poverty, disease, and poor sanitation have a tremendous impact on another vulnerable population: the children. More than one million Afghan children are orphans. About half a million are disabled. Almost 350,000 have lost a limb to landmines. Thousands of children under 5 die each year, most from diarrhea or common diseases. Aid agencies have launched major campaigns to immunize children across the country but are hampered by transportation and safety issues. A 2002 study by the U. S. Centers for Disease Control and Prevention estimated that 70 percent of Afghans suffered from clinical depression and anxiety. While those levels have dropped slightly in recent years, emotional disorders still make life difficult for millions of Afghans today. More and more young people are turning to opium to cope with their problems. Drug use and depression will make the work of rebuilding their war-torn land difficult in the coming years. SEE Also: Disease and Poverty; Healthcare, Asia and
Oceania; Women’s Health (General).
BIBLIOGRAPHY. Physicians for Human Rights, Women’s
Health and Human Rights in Afghanistan (Physicians for
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African-American Health
Human Rights, 2001); World Health Organization, “Afghanistan,” www.who.int (cited March 2007). Heather Michon Independent Scholar
African-American Health While healthcare in the United States has exhibited remarkable improvements in the past half century, evidence continues to suggest that African Americans suffer increasing disparities in the incidence, prevalence, mortality, and overall negative health outcomes in comparison with white Americans. For instance, African Americans have the highest asthma attack rates of all ethnic groups and are three times more likely than whites to be hospitalized for asthma. Black children are five times more likely than white children to have lead poisoning, which is associated with lowered IQ, learning disabilities, and behavioral problems. The prevalence of diabetes is 70 percent higher among African Americans as compared to white Americans. The death rate among black women with lupus rose by 70 percent from 1979 to 1998. African Americans are eight times more likely than white Americans to be struck by sarcoidosis, a chronic disease that interferes with the functioning of vital organs, especially the lungs. Blacks are more likely to get cancer and to die from the disease than other racial and ethnic groups. Compared to white men, black men are 1.5 times more likely to develop prostate cancer and two to three times more likely to die of the disease. Despite passage of the 1964 Civil Rights Act, numerous medical milestones, and the government’s “Healthy People” initiative to eliminate minority health disparities by 2010, African Americans still suffer much higher disease and excess death rates than other racial groups. Infant mortality, one of the nation’s most critical gauges of maternal and societal health, is twice as common in black communities as in white communities, and occurs across all socioeconomic ranges of the black community. In addition to such disparities in health, blacks also report suffering from disparities in the care they receive. Recent stud-
ies have found that 80 percent of blacks believe they receive different medical treatment and have different care options due to their race and ethnicity. socioeconomic factors Much of the disparity in health and healthcare in the African-American community has been attributed to socioeconomic factors. According to the 2000 census, 36 million people in the United States, or 13 percent of the civilian noninstitutionalized population, were black, making African Americans the second largest minority population behind the Hispanic/Latino population. Of the 20.4 million blacks and 133.4 million non-Hispanic whites 25 and older, a lower percentage of blacks had earned at least a high school diploma (79 percent and 89 percent, respectively). According to the 2000 census the average African-American family median income was $33,300 in comparison to $48,500 for non-Hispanic Caucasian families, and 23 percent of African-Americans, in comparison to 8 percent of non-Hispanic Caucasians, were living at the poverty level. The unemployment rate for African Americans was twice that for non-Hispanic Whites, both when considering men and women. In 2003, 53.9 percent of African Americans used employer-sponsored health insurance while 22.6 percent of African Americans in comparison to 8.1 percent of non-Hispanic Caucasians relied on public health insurance. A relatively small percentage, 4.7 percent of African Americans compared to 7.5 percent of nonHispanic Caucasians, relied on private insurance. Finally, a 2003 assessment concluded that 18.8 percent of African Americans in comparison to 11 percent of non-Hispanic Caucasians were uninsured. Most studies recognize an immediate and significant correlation between disparities in healthcare and disparities in these general socioeconomic factors. Primary care is the underpinning of the healthcare system, and research studies have shown that having a usual source of healthcare raises the chance that people receive adequate preventive care and other important health services. About 20 percent of black Americans lack a usual source of healthcare compared with less than 16 percent of non-Hispanic whites, and African Americans are far more likely to rely on hospitals or clinics for their usual source of care than are white Americans.
healthcare disparities Race and ethnicity influence a patient’s chance of receiving many specific procedures and treatments. African Americans are 13 percent less likely to undergo coronary angioplasty and one-third less likely to undergo bypass surgery than are whites. Among preschool children hospitalized for asthma, only 7 percent of black, compared with 21 percent of white children, are prescribed routine medications to prevent future asthma-related hospitalizations. The length of time between an abnormal screening mammogram and the followup diagnostic test to determine whether a woman has breast cancer is more than twice as long for African-American women as in white women. African Americans with HIV infection are less likely to be on antiretroviral therapy, less likely to receive prophylaxis for pneumocystis pneumonia, and less likely to be receiving protease inhibitors than other persons with HIV. African-American residents of nursing homes are all far less likely than white residents to have sensory and communication aids, such as glasses and hearing aids. Disparities in healthcare are often ascribed to differences in income and access to insurance. Medicaid coverage also affects the continuity of physician care. African Americans are less likely than whites to see one specific physician for care. As healthcare disparities have risen, and been publicized through the media, the federal government has undertaken a number of programs and campaigns aimed at relieving at least some of the problem. Among them are the 9-A-Day Program—a national campaign to encourage African-American men to eat nine servings of fruits and vegetables a day because African-American men are among the most seriously affected by diet-related chronic diseases, and have the lowest overall consumption of fruits and vegetables. The Know What to Do for Life Campaign is a national education campaign designed to help reduce the infant mortality rate among African Americans due to preterm birth, low birth weight, and sudden infant death syndrome (SIDS). The Closing the Health Gap Campaign, launched in 2001, is an educational campaign designed to address the health gap between racial and ethnic minorities and the general population. It aims to help make good health an important issue among racial and ethnic minority populations, who are affected by serious diseases and health conditions at far greater rates than other Americans. In 2002, the U.S. Department of Health and
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Human Services (DHHS) and its founding partner, the ABC Radio Networks, launched the campaign with a series of health messages for African-American communities. The following year the campaign expanded its focus to bring the best health information to more communities, including Hispanic Americans, Asian Americans and Pacific Islanders, American Indians, and Alaska Natives. Take a Loved One for a Checkup Day is another part of the campaign. The Closing the Health Gap campaign also works to spread the word about the new Medicare prescription drug benefits or changes in Medicaid drug programs. Finally, the Obesity Abatement in the African-American Community Initiative aims to bring broad and diverse segments of the African American community together to engage in data gathering, education, recreation, and nutrition programs designed to impact this life-threatening problem. Gender Both black males and females are more likely to experience health problems than their white counterparts. According to the Centers for Disease Control and Prevention’s “Deaths: Preliminary Data for 2003,” the estimate of life expectancy at birth for the total population reached a record high of 77.6 years. This represents an increase of 0.3 years relative to 2002. Although women live longer than men, the gap between male and female life expectancy did close from 5.4 years in 2002 to 5.3 years in 2003. Men have a life expectancy of 74.8 versus 80.1 years for women. All men recently saw an improvement in life expectancy. African-American men can expect to live approximately 6.2 years less than white men—69.2 years versus 75.4 years—an increase of .6 years in 2002. African-American women are more likely to die from heart disease than other groups of women. Diabetes, high blood pressure, high cholesterol, not exercising, and smoking all put women at risk for heart disease. In addition, studies have shown that African Americans don’t receive the same care for heart disease as whites because they don’t receive the same procedures and treatments. Breast, lung, and colon-rectum cancers are among the most commonly diagnosed cancer cases in African-American women. Cancer survival rates are lower overall for African-American women than for whites, and mortality for colorectal, lung, breast, and cervical
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Agency for Healthcare Research and Quality (AHRQ)
cancers are high. African-American women are more likely than all other women to die from breast cancer. Major cancer risk factors for African-American women include tobacco use, poor diet, obesity, and inadequate screening for cervical and breast cancer. There is not enough information to determine why African Americans bear this cancer burden. Some reasons may be poverty, poor access to healthcare, patients not following up after getting abnormal test results, tumors found at a later (more advanced) stage so there are fewer treatment options, different belief systems, fear of talking about cancer, and lack of trust of the medical system. African-American women have the highest rates of being overweight or obese. Being overweight or obese increases the risk of heart disease, type 2 diabetes, high blood pressure, stroke, breathing problems, arthritis, gallbladder disease, sleep apnea (breathing problems while sleeping), osteoarthritis, and some cancers. African-American women have more barriers to care than white women. Lack of health insurance is a major stumbling block to healthcare for African American women. Compared with white women, AfricanAmerican women are less likely to have health insurance. They have less access to employer-sponsored health insurance because of salary constraints and inability to pay employee premiums when health insurance is offered. Because of lower insurance coverage and a heavier reliance on Medicaid, African-American women are more likely to get routine care at a clinic or health centers and less likely to go to a doctor’s office. While overall improvement in healthcare access and quality has risen in the past few decades, the U.S. healthcare system at present does not provide an equal distribution of health resources across all racial, ethnic, and social classes. This is particularly damaging to the African-American community. Government studies as well as research funded by the private sector continues to recognize these inequities and study ways to deal with them. To date most programs have met with mixed reviews, and their success or failure continues to be tied to the long-term ebb and flow of funding. See Also: Department of Health and Human Services
(DHHS); Disease and Poverty; Healthcare, U.S. and Canada.
BIBLIOGRAPHY. Valire Carr Copeland, “African Ameri-
cans: Disparities in Health Care Access and Utilization,”
Health and Social Work (v.30/3, 2005); Barbara HewinsMaroney, Alice Schumaker, and Ethel Williams, “Health Seeking Behaviors of African Americans: Implications for Health Administration,” Journal of Health and Human Services Administration (v.28/1, 2005); January W. Payne, “Dying for Basic Care: For Blacks, Poor Health Care Access Cost 900,000 Lives,” Washington Post (December 21, 2004); Randolph Quaye, “The Health Care Status of African Americans,” The Black Scholar (v.24/2, 1994); Jen’nan Ghazal Read and Michael O. Emerson, “Racial Context, Black Immigration, and the U.S. Black/White Health Disparity,” Social Forces (v.84/1, 2005); United States Department of Health and Human Services, www.hhs.gov (cited October 2006); Karen Williams and Veronica W. Johnson, “Eliminating African-American Health Disparity via History-based Policy,” Harvard Health Policy Review (v.3/2, 2002). Ben Wynne, Ph.d Gainesville State College
Agency for Healthcare Research and Quality (AHRQ) Originally created in 1989 as the Agency for Healthcare Policy and Research in the Department of Health and Human Services (DHHS), the Agency for Healthcare Research Quality (AHRQ) is the primary federal agency in charge of improving the quality, safety, efficiency, and effectiveness of healthcare for all Americans. The research sponsored and conducted by the AHRQ is a source of information for decision makers in a variety of healthcare fields. It functions as one of 12 DHSS agencies; related agencies include the National Institutes of Health, the Centers for Disease Control and Prevention, the Food and Drug Administration, the Health Care Financing Administration, and the Health Resources and Services Administration. Since its creation, the AHRQ has concentrated on several strategic goals that revolve around promoting optimum research techniques and disseminating the best available research findings to healthcare practitioners and policy makers. Those who benefit from the agency’s mission are clinicians, hospitals, public officials at the local, state, and federal levels, medical school faculty, public and private insurers, patients,
Agency for Toxic Substances and Disease Registry (ATSDR)
and consumers in general. The agency strives to provide evidence-based information on healthcare outcomes, standards, costs, and access to allow those in critical positions to make more informed decisions and, in so doing, improve the overall quality of healthcare services in the United States. Many of the initiatives sponsored by the AHRQ are aimed at addressing concerns related to research indicating that as many as 100,000 Americans die each year as the result of misdiagnosis or other medical errors. The agency gives special attention to higherrisk populations such as low-income families, children, the elderly, minorities, and those with special needs, and routinely produces detailed reports on the disparity in healthcare delivery to these groups. Each year the agency surveys approximately 15,000 households to learn more about how American use and pay for healthcare. The AHRQ employs approximately 300 individuals and operates with an annual budget that can exceed $300 million in a given year. Approximately 80 percent of the agency’s budget is invested in grants and contracts focused on improving healthcare delivery. Research grants sponsored by the AHRQ are subject to the same scientific peer review and ranking used by the National Institutes of Health. The agency also holds regional meetings and an annual national conference, and maintains a database of publications and internet sources on a wide variety of medical matters dealing with the organization’s mission. See Also: Department of Health and Human Services
(DHHS); Healthcare, U.S. and Canada; Health Resources and Services Administration (HRSA). BIBLIOGRAPHY. Agency for Healthcare Research and
Quality, AHRQ Annual Report on Research and Financial Performance, FY 2005 (Agency for Healthcare Research and Quality, 2005); Agency for Healthcare Research and Quality, www.ahcpr.gov (cited June 2006); Carolyn M. Clancy, “Back to the Future,” Health Affairs (June 25, 2003); Carolyn M. Clancy, “AHRQ: A Tradition of Evidence,” Health Management Technology (v.24/8, 2003); Carolyn M. Clancy, “AHRQ’s FY 2005 Budget Request: New Mission, New Vision,” Health Services Research (v.39/3, 2004). Ben Wynne, Ph.d Gainesville State College
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Agency for Toxic Substances and Disease Registry (ATSDR) Formally created in 1985, the Agency for Toxic Substances and Disease Registry (ATSDR) is the product of the Comprehensive Environmental Response, Compensation, and Liability Act of 1980 (CERCLA), also known as the Superfund law. The Superfund program is responsible for locating and cleaning up dangerous hazardous waste sites in the United States. The ATSDR’s primary mission is to serve the general public by using the best available science and technology, taking responsive public health actions, and disseminating the most current health information available to prevent harmful or disease-related exposures to toxic substances. In 1986 the Superfund Amendments and Reauthorization Act broadened the responsibilities of the ATSDR in the areas of public health assessment, toxicology database creation and management, and medical education. The agency serves as the principal federal public health agency responsible for evaluating the human health effects of exposure to hazardous substances. To accomplish its goals the ATSDR works closely with national, state, and local lawmakers; community groups; healthcare providers; and with other agencies such as the Centers for Disease Control (CDC), the Department of Toxic Substance Control (DTSC), the United States Army Corps of Engineers, and the Department of Homeland Security. Along with the Environmental Protection Agency (EPA), the ATSDR is required to prepare and maintain a detailed, prioritized list of materials deemed to pose the greatest health risk to those living in the United States. The list is revised every two years to reflect the most current information available on toxic substances. The agency reviews information about hazardous materials found at waste sites and conducts all the necessary tests in the event of human exposure to toxic substances. Through agreements with appropriate state health departments and universities, the ATSDR conducts various healthcare studies defining the relationship between hazardous materials and health issues such as cancer, leukemia, asthma, multiple sclerosis, and other diseases. It creates Public Health Assessments (PHAs) of risk at sites and offers information and
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Age-Related Macular Degeneration
training to affected communities and their healthcare professionals on ways to identify, assess, control, and prevent human exposure to hazardous material. Since 9/11 the ATSDR has played a significant role in planning for responses to terrorist attacks or other sudden, large-scale healthcare emergencies. The agency is designed for a rapid response to natural disasters as well. The ATSDR is headquartered in Atlanta, Georgia, and has 10 regional offices around the country. It operates within the U.S. Department of Health and Human Services and has an annual (2006) budget of approximately $75 million. See Also: Department of Health and Human Services
(DHHS); Environmental Protection Agency (EPA); Environmental Toxicology. BIBLIOGRAPHY. Agency for Toxic Substances and Disease
Registry (ATSDR), www.atsdr.cdc.gov (cited June 2006); ATSDR, ATSDR Public Health Assessment Guidance Manual, www.atsdr.cdc.gov/HAC/PHAManual (cited June 2006); Janet L. Heitgerd, “Using GIS and Demographics to Characterize Communities at Risk,” Journal of Environmental Health (v.64/5, 2001); H.E. Hicks and C.T. DeRosa, “Great Lakes Research: Important Human Health Findings and Their Impact on ATSDR’s Superfund Research Program,” International Journal of Hygiene and Environmental Health (v.205/1–2, 2002). Ben Wynne, Ph.d Gainesville State College
Age-Related Macular Degeneration Age-related macular degeneration (AMD) is the leading cause of severe vision loss and blindness. It strikes individuals over 60 years of age with increasing risk of disease as an individual ages. AMD destroys the macula, the central part of the retina imperative for reading, driving, and recognizing people, and renders people nearly blind and severely functionally impaired. AMD is diagnosed based on changes in the macula rather than visual acuity. Early AMD is characterized
by drusen or by hyperpigmentations, without atrophy or visible choroidal neovascularization. Drusen are the major clinical feature of AMD and consist of deposits ranging in color from white to yellow that become detectable by ophthalmoscopy when their diameter exceeds 25 μm. The biogenesis of drusen remains unresolved. As drusen increase in size, the area of hyperpigmentation and hypopigmentation of the retinal pigment epithelium (RPE) in the macula increases, resulting in higher risk of late AMD. Late AMD has “dry” and “wet” forms, but whether these two forms are really the same disease remains controversial. The initial symptoms of dry AMD are visual gaps in an image, for example, letters dropped out of a line of text, while the first symptom of wet AMD is image distortion called metamorphopsia. After the initial diagnosis, about 15 percent of patients with unilateral wet AMD develop wet AMD in the other eye. If left untreated, wet AMD can rapidly lead to legal blindness (visual acuity ≤0.1, 6/60), usually within months after the second eye becomes affected. In contrast, patients with dry AMD may take years to progress to blindness. Both dry and wet forms can be found in the same patient: Dry form, also called central geographic atrophy (CGA), can occur in one eye and the wet form, also called choroidal neovascularization (CNV), in the other, or both dry and wet can be seen in the same eye. The prevalence of late AMD is approximately 1.5 percent in individuals of European descent over the age of 50, and rises progressively with age, reaching 10 percent in individuals aged 75 years or older. Prevalence of AMD is reported to be 2.4 percent in African Americans (AA), 4.2 percent in Hispanic, 4.6 percent in Chinese, and 5.4 percent in Caucasian Americans (CA). The highest prevalence of any AMD occurred in those 75 to 84 years old, varying from 7.4 percent in AA to 15.8 percent in CA and Chinese. Estimated prevalence of advanced AMD is 0.3 percent in AA, 0.2 percent in Hispanic, 0.6 percent in CA, and 1.0 percent in Chinese. The frequency of wet AMD was highest in Chinese compared with other ethnic groups. Epidemiological studies suggest that the strongest risk factors for AMD are family history, age, and cigarette smoking. The first of these almost certainly reflects genetics, as concordance rates for AMD among monozygotic twins have been reported in
several small studies to be 100 percent, and family studies indicate an approximately twofold elevated risk if there is an affected first-degree relative. The risk associated with cigarette smoking suggests a role for oxidative damage and/or vascular insufficiency. Consistent with a role for oxidative damage, the Age-Related Eye Disease Study (AREDS) found that daily supplements of zinc and the antioxidants β-carotene and vitamins C and E led to a 25 percent reduction in the rate of progression to late AMD compared with a placebo group. Geneticists initially used a candidate gene approach with the hypothesis that some cases of AMD might be caused by the same alleles responsible for the rare early-onset monogenic macular diseases. Evidence suggested that the protein-altering mutations in the genes coding for ABCR (associated with Stargardt disease or early macular degeneration, the type that blinded the singer Ray Charles) and fibulin 5, a close relative of fibulin 3/EFEMP1 (the protein that is altered in malattia leventinese), play small but substantial roles on AMD patients: Allele frequencies of about 3.5 percent in AMD patients versus 1 percent in controls for ABCR, and about 1.5 percent versus 0 percent in cases versus controls, respectively, for fibulin 5. Family studies of AMD have been technically challenging because of the late-onset nature of the disease. Younger individuals generally do not show the phenotype, while older affected individuals may have died prior to ascertainment. Despite the challenges, linkage analyses have consistently implicated several chromosomal regions. Two of the chromosomal regions implicated by linkage analysis have been strongly confirmed and refined by association studies using single nucleotide polymorphisms (SNPs). One locus, on chromosome 1q32, the CFH gene encoding a complement regulatory protein, is strongly associated with AMD. In Caucasian populations, homozygotes for the His402 allele are found in more than 25 percent of AMD patients compared to fewer than 10 percent of controls. In connection with CFH, a common sequence variant in complement factor B (CFB), another complement regulatory protein, was found to have a two- to threefold difference in frequency in AMD patients versus controls. CFB is located in the major histocompatibility complex (MHC) on chromosome 6. A second linkage region, 10q26, showed tight association with LOC387715, a sequence that by
Age-Related Macular Degeneration
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computer-based analyses was predicted to be a hypothetical gene. A genome-wide association study on a Chinese cohort found that an adjacent downstream gene HTRA1 promoter SNP is highly associated with wet AMD. The HTRA1 association was confirmed in a Caucasian population. Variations in the CFH, CFB, and HTRA1 loci account for more than 50 percent of the genetic susceptibility for AMD risk. While no treatment for dry AMD is currently available, clinicians are beginning to make headway in the noninvasive treatment interventions for wet AMD. Vascular endothelial growth factor (VEGF), an important molecule in angiogenesis, has become a main therapeutic target for wet AMD. Two of these agents designed to inhibit the action of VEGF, ranibizumab and bevacizumab, are recombinant monoclonal antibodies directed against the VEGF protein. Ranibizumab (Lucentis) is a partial antibody of 48 kD, while bevacizumab (Avastin) is a whole antibody of 149 kD. Bevacizumab was approved by the Food and Drug Administration (FDA) as a treatment for metastatic colon cancer in 2004, and ranibizumab was approved for treatment of CNV in 2006. Bevacizumab is prescribed in an off-label manner as a treatment for CNV. Four studies have shown that bevacizumab was safe and effective in treating CNV. Moreover, the cost of bevacizumab is 1/10 that of ranibizumab. For these reasons, a randomized clinical trial is highly recommended to directly compare these two drugs. Taken together, the identification of the major AMD susceptibility genes and effective treatment represent one of the most spectacular triumphs of human disease genetics. Deservedly, AMD research was recognized as one of the breakthroughs of the year in 2006. SEE ALSO: Eye Diseases (General); Geriatrics; Ophthal-
mologist; Ophthalmology.
BIBLIOGRAPHY. “Breakthrough of the Year. The Runners-Up,” Science (v.314/5807, 2006); P.T. de Jong, “Age-Related Macular Degeneration,” New England Journal of Medicine (v.355/14, 2006); A. ������������������������������� Dewan, et al., ���������������� “HTRA1 Promoter Polymorphism in Wet Age-Related Macular Degeneration,” Science (v.314/5801, 2006); A.O. Edwards, et al., “Complement Factor H Polymorphism and Age-Related Macular Degeneration,” Science (v.308/5720, 2005); B. Gold, et al., “Variation in Factor B (BF) and Complement Component 2 (C2) Genes Is Associated with Age-Related Macular
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AIDS
Degeneration,” Nature Genetics (v.38/4, 2006);������������� G. ��������� Hageman, et al.,���������������������������������������������� “A Common Haplotype in the Complement Regulatory Gene Factor H (HF1/CFH) Predisposes Individuals to Age-Related Macular Degeneration,“ Proceedings of the National Academy of Sciences of the United States of America (v.102/20, 2005); J.L. Haines, et al., “Complement Factor H Variant Increases the Risk of Age-Related Macular Degeneration,” Science (v.308/5720, 2005); J. Jakobsdottir, et al., “Susceptibility Genes for Age-Related Maculopathy on Chromosome 10q26,” American Journal of Human Genetics (v.77/3, 2005); R. Klein, et al., “Prevalence of Age-Related Macular Degeneration in 4 Racial/Ethnic Groups in the Multi-Ethnic Study of Atherosclerosis,” Ophthalmology (v.113/3, 2006); R.J. Klein, et al., “Complement Factor H Polymorphism in Age-Related Macular Degeneration,” Science (v.308, 2005); A. Rattner and J. Nathans, “Macular Degeneration: Recent Advances and Therapeutic Opportunities,” Nature Reviews. Neuroscience (v.7/11, 2006);���� A. Rivera, et al., ������������������������������������������ “Hypothetical LOC387715 Is a Second Major Susceptibility Gene for Age-Related Macular Degeneration, Contributing Independently of Complement Factor H to Disease Risk,” Human Molecular Genetics (v.14/21, 2005); E.M. Stone, “A Very Effective Treatment for Neovascular Macular Degeneration,” New England Journal of Medicine (v.355/14, 2006); Z. Yang, et al., “A Variant of the HTRA1 Gene Increases Susceptibility to Age-Related Macular Degeneration,” Science (v.314/5801, 2006). Josephine Hoh, Ph.D. Yale University
AIDS AIDS (acquired immunodeficiency syndrome) is a chronic, life-threatening disease that is caused by the human immunodeficiency virus (HIV). AIDS was first reported in the United States in 1981. The Centers for Disease Control and Prevention (CDC) published a Morbidity and Mortality Weekly Report (MMWR) in June 1981 that highlighted five cases of a rare type of pneumonia (Pneumocystis Carinii). Since this first report in 1981, AIDS has become a global epidemic affecting all people, directly or indirectly. As of January 2006, the World Health Organization (WHO) and the United Nations Joint Programme on AIDS (UNAIDS) estimate that 65
million people have been diagnosed with HIV/ AIDS, the disease has killed at least 25 million people worldwide, and currently there are at least 39 million people living with HIV/AIDS. Since the identification of HIV, scientists have made many advances in the areas of transmission control, identification of risk factors, and therapy. Scientists are working to develop a vaccine against HIV, but testing, education, and prevention are needed to curb the epidemic in the meantime. The world is seeing a rise in the rates of infection that continues to challenge the medical and scientific communities. Due to the rise of the global economy and transportation ease, HIV/AIDS has affected all regions of the world. Emergence The five cases of a rare type of pneumonia the June 1981 CDC MMWR reported were among homosexual men living in Los Angeles, California. The CDC was alerted to these cases when a seldom-used drug was suddenly being prescribed to treat this pneumonia. Subsequently, in July 1981, the CDC reported that 26 cases of Kaposi’s sarcoma (also a rare type of cancer) had been diagnosed within the previous 30 months. All of these cases of Kaposi’s sarcoma were also diagnosed among homosexual men. An overall increase of rare diseases indicated that a new virus was severely weakening patients’ immune systems and causing these rare diseases to emerge. Health authorities termed this emerging disease gay-related immune deficiency (GRID) because the initial cases were first seen among homosexual men. In 1982, scientists determined that blood, and not homosexual activity, was the carrier of this new virus. Because blood had now been determined to be the carrier of GRID, the CDC warned blood banks about this new virus as blood recipients were at risk of contracting GRID. GRID was subsequently renamed AIDS because infection was not exclusive to homosexual activity. In 1983 the French scientist Luc Montagnier discovered the virus that causes AIDS. An American scientist, Robert Gallo, also claimed to have discovered the existence of the virus. The resulting controversy was cleared up by attributing discovery of the virus to Luc Montagnier and confirmation to Robert Gallo. The virus was named HIV.
The first approved HIV test was developed and distributed in 1985 to test potentially infected people and blood supplies. Scientists, alerted to the possibly significant impact of HIV, created the International AIDS Conference to disseminate and discuss all aspects of HIV, including treatment, research, and prevention. The international community began to respond to the impact of HIV as the death toll rose exponentially. The first anti-HIV drugs (Retrovir and Zidovudine) were approved by the Food and Drug Administration (FDA) in 1987. In the same year, President Ronald Reagan responded to this emerging epidemic as “public enemy number one” and the U.S. government banned the immigration of HIV-infected individuals. This ban is currently maintained; it holds that HIV is a disease of national significance. However, the U.S. attorney general may grant a waiver for HIV-infected
Scanning electron micrograph of HIV-1 budding from cultured lymphocyte. Round bumps on cell surface represent budding virions.
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individuals to enter for events (such as short-term visits and conferences). Other countries have various policies regarding the immigration of HIV-infected people into their countries. Research continues to focus on HIV treatment for those who are infected as well as HIV vaccine development. New drugs have been developed to curb the progression of HIV to AIDS. Vaccine development has not been successful and scientists state that much research must still be done. They remain unsure whether an HIV vaccine will be found, and the HIV/ AIDS epidemic continues to worsen. Definition and Progression AIDS is a disease in which HIV causes damage to the immune system and makes one susceptible to opportunistic infections and other illnesses. HIV, a retrovirus, is the cause of AIDS. HIV is a retrovirus because it stores its genetic information on a single-stranded RNA molecule instead of the usual double-stranded DNA molecule, and because after the retrovirus penetrates a cell, it uses a special enzyme to construct a DNA version of its genes which then becomes a part of the penetrated cell’s genetic material. HIV infects human cells and uses the cells’ nutrients and energy to reproduce and grow. When a person is infected with HIV, the virus multiplies within the white blood cells, which are part of the immune system and normally protect the body from disease. The virus continues to replicate within the white blood cells and continues to damage other body cells. AIDS is diagnosed as HIV increases in prevalence in the body and causes increasing damage to the immune system. HIV causes the destruction of CD4 cells, a vital component of the immune system, and increases the number of opportunistic infections because the body is more susceptible to infections and cancers. Opportunistic infections occur in people who have compromised immune systems and are caused by various organisms. They are common among AIDS patients but are rarely seen in healthy people. The CDC defines AIDS, for someone who has already tested as HIV seropositive, as meeting at least one of the following conditions: • The presence of one or more AIDS-related infections or illnesses; and/or • CD4 cell count has fallen below 200 cells per cubic millimeter of blood.
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The period for progression from HIV to AIDS varies greatly and relies on several factors. These factors include the amount of time between the transmission of HIV and when the person is tested for HIV, the presence of antiretroviral therapy, and several other external factors such as access to care, the presence of other disease, and overall body health. Some people are co-diagnosed with HIV and AIDS and others are not diagnosed with AIDS for several years after they have been diagnosed with HIV. Some people do not develop symptoms for as long as 10 to 12 years. This long latency period (when the virus does not cause any significant symptoms) is problematic because people may not feel that they are sick and, therefore, do not feel the need to be tested for HIV. Transmission Someone who has been infected with HIV/AIDS carries the virus in certain body fluids, including blood, semen, vaginal fluids, and breast milk. Transmission of the virus can occur only when HIV-infected fluids enter the bloodstream of another person. HIV can enter the body through the vaginal lining, vulva, penis, rectum, mouth, or large cuts in the body. There have been no indications that HIV can be transmitted by saliva, tears, sweat, urine, feces, casual contact, or insects such as mosquitoes. There are three identified main transmission routes for HIV: • Sexual transmission • Blood or blood product • Mother-to-child transmission Sexual transmission of HIV occurs usually when an uninfected person has unprotected sex (anal, vaginal, or oral) with an HIV-positive person. Protected sex with an infected person is not 100 percent safe. Having protected sex involves the use of a condom that may break during sexual intercourse. Oral transmission of HIV is less likely, but can occur in such instances as when the uninfected person has open mouth sores or cuts that can be in direct contact with semen. Direct contact with HIV-infected blood can occur when infected blood comes into contact with an uninfected person in a variety of ways. Transmission by blood can also occur when infected blood comes into contact with an open sore or cut. Blood transfusion was a cause of transmission before testing procedures were established. The United States screens all blood
donations for HIV and, therefore, transmission by blood transfusion is highly unlikely in this country. Transmission from an HIV-infected mother to her child during pregnancy or when breastfeeding is another possible HIV transmission route. Pregnant women who are HIV positive can transmit HIV to their unborn children during pregnancy. Pregnant woman who are not on HIV medication treatment transmit HIV to their newborn children in an estimated 20 to 30 percent of cases. HIV medication treatment is highly effective in preventing the transmission of HIV from mother to child during pregnancy, with the risk of transmission to the newborn reduced to 1 to 2 percent. The most common ways that HIV is spread are by unprotected sex with an infected partner and/or sharing drug needles. There have been many theories regarding risky contact with bodily fluid; however, transmission not involving blood, semen, vaginal fluids, and breast milk have not been documented. Scientists state that if there were transmission routes (other than those mentioned above), then the epidemic would have looked very different and the numbers of those infected would have been much higher. The CDC investigates all cases that suggest a possible new transmission route. Symptoms/Clinical Manifestations The symptoms of HIV/AIDS vary greatly, depending on the patient’s stage of infection. When a person is initially infected with HIV, he or she may have no symptoms that are readily evident. However, within the first two to six weeks, the symptoms that usually occur are similar to when one has a flu-like illness. These symptoms include headache, fever, lethargy, and enlarged lymph nodes and they may last for one to two months. These symptoms are often overlooked by people because they are similar to other minor illnesses and, therefore, do not alarm the newly infected person. During this initial period, people are highly contagious because genital fluids contain extremely high amounts of HIV. Because the genital fluids contain much higher amounts of HIV during this time, the likelihood or transmission increases greatly. After this initial period, the infected person may be asymptomatic (not showing any symptoms) for an extended time. The National Institutes of Health states
that this period can sometimes last for as long as 10 to 12 years in some adults. During this time, the virus continues to replicate and negatively affects the immune system. As the immune system declines, the symptoms become worse. The first signs of infection include enlarged lymph nodes, lethargy, weight loss, frequent fevers, persistent or frequent yeast infections, persistent skin rashes, pelvic inflammatory disease in women, short-term memory loss, herpes, genital or anal sores, and shingles (a painful nerve disease). The virus continues to attack the immune system and symptoms worsen and increase in prevalence. As the viral load increases, the HIV-infected person’s immune system deteriorates. The symptoms that accompany the progression of HIV to AIDS include the following: • coughing and shortness of breath • seizures • lack of coordination • difficult or painful swallowing • dementia (confusion and/or forgetfulness) • severe diarrhea • fever • vision loss • abdominal cramps, vomiting, nausea • weight loss and extreme fatigue • severe headaches • coma As an HIV-infected person’s condition worsens and they develop AIDS, they become more prone to developing diseases and cancers that are otherwise rarely seen in patients. Examples include Kaposi’s sarcoma and lymphomas (cancers of the immune system). HIV Tests There are three types of tests that are used to detect HIV using blood or oral mucus samples. The tests are the antigen test, the antibody test, and the DNA or RNA test. Tests that detect the presence of HIV antibodies in the person’s bloodstream are the most commonly used. Antibodies are special proteins that are produced when HIV enters the bloodstream. HIV antibodies can be detected within six to 12 weeks from when HIV first enters the person’s bloodstream. In rare situations, it may take up to six months for a person to produce these antibodies. The most widely used antibody test is called the enzyme-linked immunoabsorbant assay (ELISA). This
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test is highly sensitive, meaning that it is very accurate in detecting HIV antibodies but may not be as effective when distinguishing HIV antibodies from other antibodies. Consequently, if a person receives a positive ELISA test, it must be confirmed by another HIV test. In the United States, the Western blot assay test is used to confirm a positive ELISA test. The Western blot test is extremely accurate and detects the presence of HIV proteins. In resource-challenged countries, a second ELISA test is often used to confirm the first positive test result. When discussing testing options, it must be noted that the HIV virus has a variable period between the point of infection (transmission) and the development of detectable antibodies. This means that there is a window of time during which the person is HIV positive and may be able to infect another person with HIV, but would test as HIV negative. The CDC states that this window of time can vary between three and six months. Most countries have established protocols for HIV testing that involve counseling before and after receiving test results. A doctor, nurse, or certified counselor discusses the meaning of the test and test results with the patient. The amount of time it takes to receive the results depends on the type of test and varies between 30 minutes (HIV Rapid Test) and one week. Treatment At the beginning of the HIV epidemic, there were very few treatment options available. There were neither medications to treat the various types of opportunistic infections that arose nor medications adequate to bolster the immune system. Since the discovery of HIV, there have been several types of drugs developed to slow disease progression from HIV to AIDS and treat the accompanying opportunistic infections and cancers. No treatment exists to cure HIV/AIDS. Current HIV/AIDS treatment consists of highly active antiretroviral therapy (HAART). HAART exists of combinations (known as cocktails) of at least three different types of HIV drugs belonging to at least two different classes of drugs. Each of these drugs interacts with the virus in different ways. The goal of these HIV medications is to decrease the viral load (the number of virus cells in the body of an infected person) and, consequently, keep the person
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healthier. The FDA has approved three groups of HIV drugs: nucleoside reverse transcriptase inhibitors, protease inhibitors, and fusion inhibitors. Nucleoside reverse transcriptase inhibitors delay the spread of HIV by interrupting the early virus replication stage (when the virus is trying to make copies of itself ) and delaying the onset of opportunistic infections. Protease inhibitors also interrupt the replication stage of the virus, but does so at a later stage during the process. Fusion inhibitors work by affecting HIV’s ability to enter into the white blood cell by blocking the merging of the virus with the cell membrane. HAART has proven to be the most effective method to stabilize disease progression and has significantly decreased the impact of HIV. HAART medication adherence is extremely important because the virus can become resistant to HAART if it is not taken as prescribed and the medications will decrease in efficacy. Medication adherence has become an important global issue because as the viral strains become resistant to various HAART medications treatment becomes extremely difficult. Post-exposure prophylaxis (PEP), consisting of anti retroviral treatment, is available to reduce the risk of transmission if it is begun immediately after direct exposure. PEP consists of taking antiretroviral medications immediately following an exposure to HIV, within 72 hours of the exposure. This treatment must be taken for four weeks and consists of two to three different medications. PEP is used after occupational exposures (such as needle pricks) and, since 2005, PEP can be used when a person has had a risky sexual encounter (such as unprotected sex or having a condom break during intercourse). Sexually Transmitted Infection(s) and HIV/AIDS It has been shown that having a sexually transmitted infection (STI) can increase the risk of acquiring HIV/AIDS. STIs can cause open sores or lesions in the skin to occur, thus increasing transmission likelihood. However, other biological events occur that also cause a person’s risk of acquisition to increase (such as tissue swelling). Studies have shown that people with an STI are more likely to contract HIV/AIDS. The risks associated with contracting certain STIs are very similar to those of HIV transmission.
Epidemiology AIDS has been one of the most devastating epidemics recorded in history. UNAIDS and the WHO estimate that AIDS has killed more than 25 million people since it was first recognized in 1981. According to the 2006 UNAIDS Global Summary, there are currently 39.5 million people living with HIV/AIDS worldwide: 37.2 million adults, 17.7 million women, and 2.3 million children aged 15 years or younger. This same report states that in 2006, at least 4.3 million people were newly infected and at least 2.9 people died from AIDS. Since 1981, great progress has been made to decrease the impact of HIV/AIDS. Developments include the identification of risk factors, development of HIV/AIDS testing and reporting standards, HIV/ AIDS prevention and risk-reduction campaigns, HAART, and an increasing focus on access to medications. Researchers have also identified new risk (hot-spot) groups and trends. Currently, there is a worldwide growth of cases among women and young adults aged 15–24. Sub-Saharan Africa is the most affected region, accounting for 63 percent of people living with HIV/AIDS. Southern Africa is the most affected sub-Saharan region, accounting for 32 percent of the global estimation for those who are living with HIV/AIDS and 34 percent of all HIV/AIDS-related global deaths. The second most affected region is south and southeast Asia, with 8.6 million living with HIV/AIDS. Global rates of HIV infection have increased in all regions. UNAIDS also states that many people do not know that they are infected with HIV/AIDS and, therefore, have not made behavioral modifications to prevent transmission. The CDC has estimated that one-fourth of infected peoples globally do not know that they are infected. The reason that people may not get tested for HIV includes lack of access to healthcare, stigmatization surrounding getting tested, and because they do not know that their behaviors cause them to be susceptible to HIV acquisition. This lack of testing also causes current HIV/AIDS prevalence and incidence (measuring the global burden of disease) to be inaccurate. Consequently, all statistics and estimates regarding HIV/AIDS are likely underestimates. Risk Populations HIV can be transmitted to anyone who is exposed to the virus and does not protect him- or herself properly.
The CDC states that each year, more than 5 million people globally are infected with HIV. Many people are at risk for acquiring HIV, but some people are more susceptible due to their or their partner’s risk behavior(s). According to the CDC, the following populations are the most vulnerable to HIV infection: • injection drug users • drug and alcohol substance abusers • commercial sex workers and their partners • youth and street children • prison populations • men who have sex with men These risk populations all have different characteristics associated with infection. These characteristics are often dependent on regional social and cultural characteristics, including (but not limited to) religious beliefs, stigmatization of healthy behaviors (such as condom use), disenfranchisement, and lack of education. Some of these reasons are due to biological vulnerabilities. Women are more likely to contract HIV when having vaginal sex with an HIV-infected person than an uninfected man is when he is having vaginal sex with an HIV-infected woman. Apart from biological vulnerabilities, risk behaviors are what cause others to be vulnerable to contracting HIV. In the United States, HIV infection rates have remained alarmingly high among young people, minority groups (African Americans and Hispanics), and women. Cultural and social environments that influence one’s ability to avoid specific risk behaviors can exacerbate biological vulnerabilities. Much attention has been given to women and their ability to negotiate safer sex behaviors. Economic Impact The HIV/AIDS epidemic has affected life expectancy in certain hard-hit areas and, therefore, has negatively impacted labor force and human capital. The hardest-hit regions are also those areas with the least resources. In these areas, the population is affected by the cost of medical care, the inability to work due to medical condition, deaths, rising numbers of orphans, and an overall inability to cope with the impact of HIV/AIDS. As more people become infected, the labor force decreases. Policy makers, public health officials, and HIV/ AIDS scientists have pursued several goals to control and reduce HIV transmission rates. These goals in-
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clude addressing social and cultural environment issues, increasing access to antiretroviral medications, increasing HIV/AIDS prevention and risk-reduction knowledge and practice, and increasing access to medical care. Scientists have been pushing global agendas that promote HIV testing as a means for controlling the spread of HIV. Increases in HIV testing will ensure that more people become aware of their HIV status and make behavioral changes, therefore limiting the spread of HIV. Testing will also increase the reliability of HIV/AIDS surveillance data. SEE ALSO: AIDS and Infections; AIDS and Pregnancy;
AIDS—Living with AIDS; AIDS-Related Malignancies; International AIDS Vaccine Initiative (IAVI); Joint United Nations Programme on HIV/AIDS (UNAIDS). BIBLIOGRAPHY. AIDS Education Global Information Sys-
tem (AEGIS), “So Little Time . . . : An AIDS History,” www .aegis.com (cited February 2007); amfAR, The Foundation for AIDS Research, www.amfar.org (cited February 2007); AVERT, “The Origins of HIV and the First Cases of AIDS,” www.avert.org (cited February 2007); Centers for Disease Control and Prevention, MMWR Weekly (v.30/21, 1981); Centers for Disease Control and Prevention, “HIV/AIDS,” www.cdc.gov/hiv (cited February 2007); Joint United Nations Programme of HIV/AIDS, Report on the Global AIDS Epidemic 2006, www.unaids.org/en/HIV_data/ 2006GlobalReport (cited February 2007); Joint United Nations Programme of HIV/AIDS, “UNAIDS/WHO AIDS Epidemic Update: December 2006,” www.unaids.org/en/ HIV_data/epi2006 (cited February 2007); U.S. Department of Health and Human Services, “AIDSinfo,” aidsinfo.nih .gov (cited February 2007). Sudha Raminani The Fenway Institute
AIDS and Infections Infection with the human immunodeficiency virus (HIV) leads to a progressive destruction of the human immune system. At the point where the immune system is no longer able to defend against pathogens, HIV-positive individuals frequently present with opportunistic infections, and are then considered to
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Infection with the human immunodeficiency virus (HIV) leads to a progressive destruction of the human immune system. As the price of antiretroviral (ARV) therapy has decreased in recent years, an increasing number of HIV-positive individuals have access to treatment worldwide.
have acquired immunodeficiency syndrome (AIDS). The majority of these infectious agents are of little consequence to a person with an intact immune system; however, the unifying theme for opportunistic infections is their increased frequency and severity in those living with HIV. These infections can be divided into several categories, including bacterial, viral, fungal, and protozoan. When an HIV-positive individual has access to and is treated with antiretroviral (ARV) therapy, the incidence of opportunistic infections is reduced but not eliminated. Globally, the majority of those infected with HIV do not have access to ARV therapy, making it important to recognize and treat AIDS-related infections. The most common bacterial opportunistic infection in those living with HIV is caused by Mycobacterium tuberculosis, the pathogen that causes tuberculosis (TB). TB is transmitted when someone with active disease coughs or sneezes, releasing droplet nuclei of live bacterium into the air. When most people inhale this live bacterium, they develop latent TB infection, and are therefore neither sick nor infectious. Approximately 2 billion individuals worldwide are latently infected with TB. However, the immune destruction related to HIV infection leads to an increased risk of TB
reactivation from latency. In individuals who are HIV positive, TB is more difficult to diagnose and progresses faster, leading to increased morbidity and mortality. Active TB infection leads to a severe cough that often progresses to coughing up blood, chest pain, weight loss, chills, fever, and night sweats. Candida is the most common HIV-related fungal infection, most commonly with Candida albicans, and occurs in over 90 percent of HIV-infected individuals at some point in the course of the disease. Candida is often part of the normal flora of a healthy human mucosa, and overgrowth is kept in check by the immune system. However, in those with HIV, the immune system can no longer control the fungal growth, with infection typically occurring on or around mucous membranes, such as the mouth (thrush), esophagus, and vagina. Oral thrush appears as a white film over the tongue, oral mucosa, and throat. Often the lesions are painful, making eating and drinking difficult with thrush. Vaginal Candida infections are called yeast infections. While any woman can develop a yeast infection, HIV-positive women often get recurrent yeast infections. These women experience frequent vaginal itching and burning, as well as white vaginal discharge.
Viral infections can have severe consequences for those living with HIV. Infection with oncogenic viruses, such as human herpes virus-8, human papilloma virus, and Epstein Barr virus, leads to higher rates of the malignancies Kaposi’s sarcoma, AIDS-related lymphoma, and invasive cervical cancer, respectively. Cytomegalovirus infection (CMV), which is common in the general population, can have severe effects on those with HIV. Most frequently, CMV will cause retinitis, or inflammation of the retina, the layer of cells at the back of the eye. This inflammation can lead to vision changes and rapid progression to blindness. One of the most common protozoa (single-celled parasite) infections worldwide, encephalitis caused by Toxoplasma gondii, has a significant impact on those living with HIV. Most individuals come into contact with Toxoplasma infection via eating undercooked meat, drinking contaminated water, or contact with cat feces. In someone with a healthy immune system, there is generally no consequence to infection. However, in an HIV-positive individual, a latent infection from within skeletal muscles, heart, or brain will more frequently reactivate. Encephalitis is characterized by headaches, changes in mental status, fever, motor weakness, and speech disturbances. Toxoplasmosis can also cause severe ocular and pulmonary disease in HIV-positive individuals. As the price of ARV therapy has decreased in recent years, an increasing number of HIV-positive individuals have access to treatment worldwide. However, lack of healthcare infrastructure, a paucity of trained healthcare workers, lack of political will and significant international investment, and stigma surrounding treatment all conspire to prevent universal access to ARV treatment in the developing world. In such a setting, the burden of opportunistic infections remains high. Therefore, prevention and treatment of these diseases may allow for decreased morbidity and mortality. SEE ALSO: AIDS; AIDS—Living with AIDS; AIDS-Related
Malignancies; National Center for HIV, STD, and TB Prevention (NCHSTP); Tuberculosis. BIBLIOGRAPHY. Centers for Disease Control and Preven-
tion, “HIV/AIDS,” www.cdc.gov/hiv (cited January 2007); C.B. Holmes, et al., “Review of Human Immunodeficiency Virus Type 1-Related Opportunistic Infections in Sub-Sa-
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haran Africa,” Clinical Infectious Diseases (v.36/5, 2003); U.S. Department of Health and Human Services, “AIDS info,” aidsinfo.nih .gov (cited January 2007). Christine Curry Independent Scholar
AIDS and Pregnancy As the HIV epidemic becomes increasingly feminized and concentrated among young people, the reproductive health rights and needs of HIV-positive women and their children are becoming more of an urgent health concern. While the mother herself faces only a small risk of increased morbidity due to HIV during pregnancy, mother-to-child HIV transmission has been a major source of new infections in the past. Also called perinatal or vertical transmission, an HIV-positive woman can transmit the HIV virus to her baby during pregnancy, labor, and delivery, or while breastfeeding. If a woman takes no preventative drugs, the chance of passing on the virus to an infant is approximately 15 to 30 percent, rising to about 45 percent with prolonged breastfeeding. In 2005, approximately 700,000 children under 15 acquired HIV, largely from mother-to-child transmission. Ninety percent of the more than 5 million children who have been infected with HIV live in Africa. While preventing unwanted pregnancies among HIV-positive women is an important step in reducing the number of mother-to-child HIV infections, many HIV-positive women want to or will become pregnant. Fortunately, a short course of antiretroviral drugs taken before birth, around the time of delivery, together with formula feeding, can reduce the risk of mother-to-child transmission to less than 2 percent. Zidovudine (AZT) has proved particularly effective in preventing mother-to-child transmission. While AZT should ideally be started shortly following the completion of the first trimester, in limited-resource settings, AZT will be given from 28 weeks gestation onward, along with a single dose of AZT and nevirapine administered during labor. Although many women have taken antiretroviral medication during pregnancy to treat their own illness without drastic effects on infant growth and development, little population data
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are available regarding side effects of antiretrovirals taken during the first trimester, when the fetus faces the highest risk of developing developmental defects. While previous research suggests that particular delivery methods, such as Caesarian births, might prove effective in preventing mother-to-child transmission, this evidence is still considered inconclusive. In many countries, the increased risk of maternal death due to complications from Caesarian surgery probably outweighs the decreased probability of HIV transmission to the infant. While these drugs were largely unavailable in the past, much progress has been made in using short courses of drugs to cut mother-to-child HIV transmission rates even in rural areas lacking much health infrastructure. Continuing challenges to motherto-child transmission prevention programs include refusal to take an HIV test, a fear of HIV-based discrimination, and a lack of follow-up care. Women in many countries who are HIV positive and pregnant often face discrimination from medical care providers, which also discourages them from returning to clinics for follow-up visits. Many women also report that they are afraid their children will be taken away from them, either because they are HIV positive or because they engage in high-risk behaviors such as intravenous drug use or sex work. The proven effectiveness of short-term antiretroviral therapy combined with formula feeding in preventing mother-to-child HIV transmission has posed a dilemma to many new mothers in developing countries, where the health risks of feeding infants formula mixed with unclean water potentially outweigh the benefits of avoiding HIV transmission. Furthermore, in many countries formula is unavailable or prohibitively expensive, or women face cultural pressure to breastfeed. In these settings, additional doses of antiretroviral drugs may help decrease mother-to-child transmission during breastfeeding. Another dilemma facing HIV-positive women who want to become pregnant, or HIV-positive men who want to father a child, is how to conceive without sexually transmitting HIV to an uninfected partner. HIVpositive women can be artificially inseminated, which provides complete protection to the male partner but none to the baby. The only protection available for HIV-positive men seeking to impregnate an HIVnegative woman is sperm washing, separating sperm
cells from seminal fluid, ensuring that the sperm cells themselves are free of the virus, and then fertilizing the mother via in vitro fertilization or artificial insemination. While this technique is highly effective, it is available to only a tiny minority of patients even in nations with many reproductive health resources. For the vast majority of serodiscordant couples (where one member is HIV positive and the other is not), sexual intercourse remains the only option. HIV transmission rates are lower for those receiving antiretroviral therapy and among those who are not currently infected with other sexually transmitted infections. SEE ALSO: AIDS and Infections; AIDS—Living with AIDS;
AIDS-Related Malignancies; Pregnancy.
BIBLIOGRAPHY. AVERT, “Preventing Mother-to-Child
Transmission of HIV,” www.avert.org/motherchild.htm (cited February 2007); Centers for Disease Control and Prevention, “HIV/AIDS,” www.cdc.gov/hiv (cited February 2007); Joint United Nations Programme of HIV/AIDS, Report on the Global AIDS Epidemic 2006, www.unaids.org/ en/HIV_data/2006GlobalReport (cited February 2007); U.S. Department of Health and Human Services, aidsinfo .nih .gov (cited February 2007). Annie Dude University of Chicago
AIDS, Living with Acquired immunodeficiency syndrome (AIDS) is a collection of symptoms and infections resulting from specific damage to the immune system. It is caused by the human immunodeficiency virus (HIV). HIV is transmitted through direct contact with mucous membranes or bodily fluids, such as blood, semen, preseminal fluid, vaginal fluid, and breast milk. Transmission can occur through vaginal, anal, or oral sex; blood transfusions; hypodermic needles; childbirth; or breast-feeding. HIV is thought to have originated in sub-Saharan Africa during the 20th century and first appeared in the United States in 1981. It is currently a pandemic of enormous magnitude, with an estimated 38.6 million people infected worldwide. According to the Joint United Nations Programme on HIV/AIDS (UNAIDS)
and the World Health Organization (WHO), as of January 2006, AIDS has killed more than 25 million people. In 2005 alone, AIDS claimed an estimated 2.4 to 3.3 million lives, of which more than 570,000 were children. One-third of these deaths have occurred in sub-Saharan Africa, retarding economic growth and destroying human capital in the region. HIV targets specific cells in the human immune system, namely CD4+ T-cells, dendritic cells, and macrophages. When initially infected with the virus, a person may experience flu-like symptoms. As the body responds to the infection, there is often a clinically latent phase lasting a median of nine to 10 years. However, the rate of clinical progression varies widely between individuals, ranging from two weeks up to 20 years. The late stage of the condition leaves an individual’s immune system severely compromised—often defined as having a CD4+ count of less than 200 cells per microliter (normal is between 500–1,800 cells/µL). At this level of immunodeficiency, people become susceptible to opportunistic infections, such as Pneumocystis jiroveci pneumonia, tuberculosis, cryptosporidiosis, cryptococcus neoformans, toxoplasmosis, cytomegalovirus (CMV), and mycobacterium avium complex (MAC). Additionally, people are at increased risk of developing certain cancers, for example, Kaposi’s sarcoma and lymphoma. Although there is no cure for HIV and AIDS, treatments do exist that have effectively slowed the virus’s progression. Antiretroviral treatment reduces both the mortality and the morbidity of HIV infection. Access remains a compelling issue, as antiretroviral medications are not available in many countries. To further complicate the matter, an HIV/AIDS diagnosis brings with it a stigma that is frequently as severe as the associated life-threatening conditions, making prevention campaigns and treatment exceedingly difficult. Diagnosis Many people living in the developing world are unaware that they are infected with HIV. Less than 1 percent of the sexually active urban population in Africa has been tested, and this proportion is even lower in rural communities. There are typically two tests conducted to detect HIV—enzyme-labeled immune serum assay (ELISA) and the Western blot assay—the latter being a confirmatory test to reduce
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the number of false positives with ELISA. However, the time between initial infection and seroconversion can vary between individuals—often referred to as the window period. This explains why a positive test is unlikely until approximately three to six months after exposure. It is often imperative to diagnose HIV infection as early and readily as possible. As a result, tests are available to detect HIV antigens, HIV-RNA, and HIV-DNA prior to the development of detectable antibodies. Although these tests are not specifically approved for the diagnosis of HIV, they are commonly utilized in developing countries due to their relatively low cost and ease of use. Once diagnosed with HIV, it is crucial to be followed regularly by a physician. Blood samples will be taken often in order to determine a CD4 count and viral load to follow the disease’s progression/regression. It is possible to have an element of control over HIV and issues such as diet, proper hygiene, safe sexual practice, and medication regimens should not be undervalued. Staying Healthy with HIV When diagnosed with HIV there are many things one can do to stay healthy longer. Heeding the advice of a healthcare provider who is knowledgeable in HIV is paramount. This includes always complying with scheduled appointments, following treatment guidelines, and promptly reporting any and all symptoms or side effects. The influenza and pneumococcal (community-acquired pneumonia) vaccinations are especially important when infected with HIV and a doctor can suggest the best time for them to be administered. As with most things, adopting generally healthy habits is prudent. Smoking and illicit drug use should be stopped as quickly as possible. Eating healthy foods and regular exercise will also keep the body strong, well nourished, and better able to combat assailing diseases. The body should be getting adequate rest, physically and psychologically. Research has shown that individuals with HIV who have social, physical, and/or emotional outlets cope better with the stress of having the disease and are overall happier and healthier. Specific precautions are advised for women with HIV. A physician should examine women for other sexually transmitted diseases (STDs) and perform a Pap smear test at least once a year. Women with HIV are more susceptible to viruses such as the human
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papillomavirus (HPV), some subtypes of which are associated with cervical cancer. Protecting Others from HIV HIV is most commonly transmitted during sexual relations and it can take only one episode of intercourse for transmission to occur. Condoms, when used correctly, can significantly reduce the transmission of HIV and other STDs. Similarly, it is recommended to use condoms or other barriers during oral sex. Communication with sexual partners is critical even if it is often extraordinarily difficult. People who may have been exposed in the past and who may be exposed in the future have a right to know. Local public health departments can often help facilitate this process. It is equally important to remember that HIV can be transmitted via other bodily fluids; therefore, HIV-positive people must not share needles or donate blood, plasma, or organs. It has also been recommended, regardless of the context, to not share toothbrushes and razors. During pregnancy, the chances of passing HIV to the child are approximately 25 percent. However, this figure is greatly reduced if one takes antiretrovirals. Patients need to be adequately informed about the risks and benefits of antiretroviral therapy (ART) during pregnancy. It is vital to receive the proper prenatal care because factors such as smoking and Caesarian section have been shown to greatly increase the chances of vertical transmission. The baby may also be at risk if exposed to live attenuated vaccination and will also likely need ART once born. Although HIV can be passed through breast milk, the WHO currently recommends that mothers with HIV in developing countries breast-feed their children because the childhood morbidity and mortality associated with not breast-feeding in this context is too grave. Ideally, the mother would concomitantly be receiving ART. Treatment Unlike measles, mumps, rubella, and many other commonly vaccinated viruses, there is no vaccine available against HIV or AIDS. The only known foolproof method of prevention is avoiding exposure. This posed a significant problem for healthcare professionals routinely working with HIV-infected individuals until the advent of postexposure
prophylaxis (PEP). Research using a primate model suggests that when healthcare professionals are exposed to HIV, administering combivir (3TC and ZDV) within 48 hours of inoculation, every day for four weeks, may reduce the risk of systemic infection by 81 percent. PEP should not be taken lightly, however, because it is associated with several unpleasant side effects, including diarrhea, malaise, nausea, and fatigue. HIV is currently treated with highly active antiretroviral therapy (HAART). HAART was introduced in 1996 and has been beneficial for many HIV-infected individuals around the world. The most recent form of HAART consists of a cocktail of at least three drugs belonging to at least two different classes or families. This typically includes two nucleoside reverse transcriptase inhibitors (NRTIs) plus either a protease inhibitor or a nonnucleoside reverse transcriptase inhibitor (NNRTI). Until recently, HAART was not available in many developing countries. As a result of world pressure, however, generics have now flooded the markets and large pharmaceutical companies and patent holders have made agreements with developing countries to ensure that HAART is more readily accessible. This trend has yet to become ubiquitous. In many instances, HAART must be reserved for those with both the greatest need and greatest chances for survival. Concerns about compliance and potential resistance are significant factors that are taken into account. HAART may stabilize a patient’s symptoms and viremia, but it is in no way a cure. Treatment is usually continued for life, as symptoms and a high viral load will return if it is stopped. For example, without HAART, 40 percent of HIV-infected children in developing countries will progress to AIDS and die within two years of being infected. SEE ALSO: AIDS; AIDS and Infections; AIDS and Preg-
nancy; AIDS-Related Malignancies.
BIBLIOGRAPHY. Centers for Disease Control and Preven-
tion, “1993 Revised Classification System for HIV Infection and Expanded Surveillance Case Definition for AIDS among Adolescents and Adults,” www.cdc.gov/mmwr (cited February 2006); Divisions of HIV/AIDS Prevention, Centers for Disease Control and Prevention, “HIV and Its Transmission,” www.cdc.gov/nchstp (cited May
AIDS-Related Malignancies
2006); C.B. Holmes, et al., “Review of Human Immunodeficiency Virus Type 1-Related Opportunistic Infections in Sub-Saharan Africa,” Clinical Infectious Diseases (v.36/5, 2003); L. Kumaranayake and C. Watts, “Resource Allocation and Priority Setting of HIV/AIDS Interventions: Addressing the Generalized Epidemic in Sub-Saharan Africa,” Journal of International Development (v.13/4, 2001; J.L. Marx, “New Disease Baffles Medical Community,” Science (v.217/4560, 1982); D. Morgan, et al., “HIV-1 Infection in Rural Africa: Is There a Difference in Median Time to AIDS and Survival Compared with that in Industrialized Countries?” AIDS (v.16/4, 2002); D. Morgan, et al., “Progression to Symptomatic Disease in People Infected with HIV-1 in Rural Uganda: Prospective Cohort Study,” British Medical Journal (v.324/7331, 2002); San Francisco AIDS Foundation, “How HIV Is Spread,” www.sfaf.org (cited May 2006); World Health Organization, “Interim Proposal for a WHO Staging System for HIV Infection and Disease,” Weekly Epidemiological Record (v.65/29, 1990). Jared Daniel Ament Independent Scholar
AIDS-Related Malignancies The onset of the acquired immunodeficiency syndrome (AIDS) epidemic was heralded by an increased incidence of a rare malignancy, Kaposi’s sarcoma (KS), in 1981. Since then, scientists have recognized that individuals with AIDS have an increased risk of developing several malignancies, including KS, AIDS-related lymphoma (ARL), and invasive cervical cancer. Both KS and invasive cervical cancer are malignancies associated with viral infection: human herpesvirus-8 (HHV-8) and human papillomavirus (HPV), respectively. Additionally, almost half of all cases of AIDS-related lymphomas are associated with HHV-8 or Epstein Barr virus (EBV). KS is the most common neoplasm arising in HIVinfected individuals. Skin lesions on the lower extremities, face, and genitalia are characteristic of KS. Early lesions (patch stage) may evolve into more advanced lesions (plaque stage) as the KS tumor cells proliferate and involve more of the dermis. These lesions may eventually become ulcerating tumors (nodular stage).
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As compared to KS found in other epidemiologic groups (endemic-KS, iatrogenic-KS, and classic-KS) subsequent metastasis is common in AIDS-KS, with frequent sites including the oral cavity, gastrointestinal tract, and lungs. Lymphedema, particularly in the face, genitalia, and lower extremities, may be extensive. ARLs are a heterogeneous group of tumors largely of B-cell derivation. The development of ARL generally correlates with a low CD4+ T-cell count, high HIV viral load, increased age and male gender. There are differences between the lymphomas associated with AIDS and those seen in the general population. ARL are often more advanced and severe; have involvement in areas outside of lymph nodes including the bone marrow, body cavities, jaw and soft tissues; and are associated with HHV-8 and EBV infection. While the prevalence of oral, anal and cervical HPV infections is increased in HIV positive individuals, as is the incidence of invasive cervical cancer, the development of cancer is not correlated with a decreased CD4 T-cell count. Therefore, unlike in the cases of KS and ARL, antiretroviral therapy (ARV) therapy has not decreased the incidence of HPV-associated tumors. As cervical cancer is the second most common female cancer worldwide, and as more women are becoming infected with HIV, increased screening for cervical cancer is indicated in HIV-positive women. There are disparities in the morbidity and mortality of AIDS-related malignancies between the developed and developing world. Since the introduction of ARV, KS incidence in HIV-positive individuals has decreased in developed nations. Similarly, decreased incidence of certain ARLs is seen in those treated with ARVs. In contrast, in the developing world, where there is high HIV prevalence and little access to ARVs, the disease burden associated with AIDS-related malignancies remains high. For example, patients in sub-Saharan Africa with AIDS-related KS have high tumor burdens and rapid disease progression resulting in a life expectancy of fewer than 6 months. In summary, HIV infection is associated with increased incidence of several malignancies that have significant morbidity and mortality, thus making the screening for and treatment of these cancers an important part of HIV management. SEE ALSO: AIDS; AIDS and Infections; AIDS, Living with;
Cancer.
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Air Pollution
BIBLIOGRAPHY. Centers for Disease Control and Preven-
tion, “HIV/AIDS,” www.cdc.gov/hiv (cited January 2007); E. Feigal, A. Levine, and R. Biggar, AIDS-Related Cancers and Their Treatment (Informa Healthcare, 2000); U.S. Department of Health and Human Services, aidsinfo.nih.gov (cited January 2007). Christine Curry Independent Scholar
Air Pollution Air pollution is the presence of one or more contaminants in the outdoor environment in quantities and durations that can injure human, plant, or animal life and reduce the quality of life or conduct of business. Air pollution basically consists of several different agents, whether chemical, physical, or biological, that taint the earth’s air supply and cause many problems, making this type of pollution a major global issue. One of the causes of air pollution is our process of burning carbon-based fossil fuels for energy, which releases particulate matter (such as diesel emissions) into the air. Every day, humans consume fossil fuels for energy to use for personal and industrial purposes in their automobiles, homes, and manufacturing plants. Some environmentalists also believe that burning charcoal and wood in barbecues and fireplaces releases significant amounts of air pollutants into the atmosphere. The release of such noxious gases creates further pollution that serves as a catalyst in chemical reactions when combined with other atmospheric gases (e.g., carbon monoxide, sulfur dioxide, nitrogen oxides, chemical vapors, particulates, and other pollutants). The greatest danger of air pollution is the geographic range it can cover. Pollution in the air can reach from one end of a country to the other. For example, during the first Persian Gulf war, when Saddam Hussein set fire to Kuwait’s oil fields, the environmental effects were catastrophic. The smoke from the fires covered nearly all of Kuwait, darkening the sky and thickening the air. H.M. McClain quotes a Kuwaiti who compared breathing that air to “taking the exhaust pipe of a diesel truck in your mouth.’” It is difficult to contain air pollution, so the best way to deal with it is to stop it before it becomes airborne.
Despite recent efforts to control it, the effects of air pollution are still prevalent. Sources Because air pollutants are classified by how they are formed, it is important to know which ones are directly released into the atmosphere and which are subsequently formed by chemical reactions that take place in the atmosphere. Air pollution is also characterized by geographic source. The geographic sources of air pollution are divided into three main categories: point source, line source, and regional source. Point sources refer to any air pollutants that result from a single “ejection” point. For example, a volcanic eruption or a manufacturing plant would be a point source. A line source of pollutants occurs when a number of point sources are connected. The prime example of a line source is a long traffic jam extended over a stretch of highway. A regional source is comprised of any number of point and line sources that pollute a large area. Some examples of regional sources include fuel combustion, industrial process losses, and waste disposal. Generally, people associate air pollution with human activity, though this is not always the case. Anthropogenic sources are those caused by human activities, such as the burning of fuel and combustion within factories and power plants. Motor vehicles and large marine vessels running mainly on coal or fuel power generate harmful fuel emissions into the air. Stoves or furnaces that run on wood, coal, natural gas, oil, or fuel also release toxic chemicals into the air. Landfills, with their tons of waste, can produce methane gas and release it into the environment. The military’s use of nuclear weapons, toxic gases, and germ warfare also discharges harmful emissions into the atmosphere. Even household products can have extremely harmful effects: The fumes from paint, varnish, aerosol sprays, and other solvents can cast harmful vapors into the air. Air pollution can also be caused or produced by natural occurrences. Forest fires, plant pollen, and volcanic eruptions are all examples of natural sources of air pollution. In 1815, the largest volcanic eruption in modern history took place. The eruption of the Tambora volcano in Indonesia shot ash approximately 15 miles into the atmosphere. The result was widespread famine from loss of crops due to the ash blocking critical sunlight. In England, there was frost every day in 1816 and crops not killed by the frost rotted or did not
Air Pollution
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ripen due to a lack of sunlight. The average temperature decreased between 1.6 degrees and 3.2 degrees C and the period became known as the year without a summer. On a sociological level, the effects of air pollution were apparent after food became scarce. In Wales, people starting to panic and rioted for food. Reducing anthropogenic emissions became an important issue after the devastating events of December 4–10, 1952, in London, England. Fireplaces and coal heating were common; they produced arsenic, cadmium, carbon dioxide, and carbon monoxide as by-products. To make matters worse, a high-pressure cell began to center on the city, resulting in a point source of stagnant polluted air. By December 6, 1952, people started to suffer from respiratory problems. The following day, London hospitals became crowded with patients and people started dying. It was not until December 10, 1952, that the high-pressure cell began to move. After the crisis was over, the death toll was estimated at 4,000 people. Effects The effects of air pollution have been divided into several categories so that better analyses of pollutants can be conducted. Effects include aesthetic losses, economic losses, safety hazards, personal discomfort, and health effects. Aesthetic effects include any changes caused by air pollution that result in the loss of visually pleasing scenery. Economic losses include the loss of vegetation and livestock due to massive exposure to the gaseous air pollution. These particles can kill or sicken commercial crops and livestock. Other losses may occur as people’s possessions deteriorate as a result of the pollution, which can cause the build up of dirt or dust particles, the corrosion of metals, the weathering of stone, or the accelerated cracking of rubber. An additional effect of air pollution is personal discomfort and health hazards. Eye irritation, asthma, bronchitis, and sinusitis are a few of the health risks caused by air pollution. These are the more minor risks of air pollution that are usually acute and curable. The more serious health risks are chronic, incurable, and life threatening and include miscarriages, nervous system damage, birth defects, and even death in the form of overexposure or cancer. Scientists receive information about air pollution in two ways—monitoring and models. Monitoring is usually done with animals as test subjects. These ani-
Some efforts to curtail air pollution have succeeded. Removing lead from gasoline reduced the amount of lead in the air by 89 percent.
mals are exposed to various chemicals and monitored by scientists who draw conclusions based on their observations. Modeling involves a systematic approach of receiving data from individuals or groups from various locations. For example, people in New York City, where the air pollution is high, may record the many types of health problems that they experience. An atmospheric effect of air pollution that has become common is acid rain, which is one of the most damaging pollutions. Acid rain is caused when foreign gases are introduced into the air by large factories and automobiles. More technically, acid rain is caused by the emission of sulfur dioxide and nitrogen oxides from the combustion of fossil fuels. As its name suggests, acid rain is more acidic than regular rain water. The acidity of a fluid is measured on the pH scale, a scale that goes from 0 to 14. From 0 to 6 a fluid is acidic and from 8 to 14 a fluid is base. A pH of 7 is the middle ground, where purified water falls. Rain water has a pH of about 5.6 or 5.7. Acid rain has
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been recorded with a pH as low as below 2. For comparison, the pH of bottled lemon juice is 2.1. Acid rain is responsible for making rivers and lakes around the world unsuitable for aquatic life, punching a hole in the ecosystem which, in turn, completely disrupts the rest of the environment. It also contaminates water reservoirs in the drinking water supply system with poisons that cause cardiovascular complications in people. Aside from the more general effects of air pollution, the result of acid rain is prevalent in the ecosystems of the world. In North America and parts of Europe, acid rain has caused the “acidification” of lakes and streams. The ecosystems existing in these lakes are sensitive to the water’s pH level. When a lake’s pH reaches 4.0, it is considered dead. The ozone layer is responsible for absorbing large amounts of harmful ultraviolet radiation emitted by the sun. Therefore, any disturbance in the ozone layer’s function could have drastic effects. The most clearly established human health effect of ozone depletion is an increase of the incidence of skin cancer in light-skinned populations. Some scientists believe that global warming is a direct result of the emission of gases such as methane, nitrous oxide, and refrigerants. The greenhouse effect occurs when the sun’s rays are permitted to enter the earth’s lower atmosphere but are unable to leave. As a result, the gases become trapped and increase the earth’s overall temperature. The negative impacts of global warming include sea-level rise, soil moisture abnormalities, and an increase in ozone depletion. The rate of ozone depletion is actually increased when hot air becomes trapped in the lower atmosphere. Regulation Although air pollution from natural occurrences is unavoidable, air pollution caused by human activity is preventable. For example, cars emit carbon monoxide, a poisonous gas, into the atmosphere because humans continue to produce and use these air polluting vehicles. From 1970 to 1990, air pollution trends of certain chemicals have clearly dropped. Simply by removing lead from gasoline, the reduction of lead in the air between 1982 and 1991 was 89 percent. Other than lead, sulfur dioxide, nitrogen oxides, and carbon monoxide have also decreased over the years. A number of laws have been passed since the 1950s regarding clean air. The Air Pollution Control
Act of 1955 was the first federally enacted legislation passed to help prevent air pollution. The Clean Air Act of 1963 set forth standards to which the act would abide by. The act helped industries and government to work cooperatively to reduce emissions and promote research and development for cleaner manufacturing processes. Upon the founding of the U.S. Environmental Protection Agency (EPA) in 1970, Congress set forth the goals of prevention, control, and abatement of air pollution. Currently, the EPA has several duties and tasks which include developing and enforcing regulations, offering financial assistance, performing environmental research, furthering environmental education, and publishing information. The EPA works in conjunction with Congress to generate and enforce the appropriate regulations. With laboratories located throughout the nation, the EPA performs various forms of research to identify, understand, and solve environmental issues past and present. As a method of monitoring the EPA’s actions, the Government Performance and Results Act of 1993 was passed. Air pollution continues to be a serious issue for all societies of the world. The problem has been improving but still has not been fully alleviated. With the help of technology, organizations, laws, and legislations, society as a whole has the responsibility to take a stand in preventing further catastrophic events from taking place. Although some events are inevitable, taking action now to modify human behavior will surely benefit humankind in the future. SEE ALSO: Asthma; Asthma in Children; Indoor Air Pollu-
tion; Respiratory Diseases (General).
BIBLIOGRAPHY. R.H. Boyle and R.A. Boyle, Acid Rain
(Schocker Books, 1983); B.G. Liptàk and D.H.F. Liu, Air Pollution (Lewis Publishers, 2000); H.M. McClain, “Environmental Impact: Oil Fires and Spills Leave Hazardous Legacy,” www.cnn.com (cited September 2006); R. Miller and W.E. Miller, Contemporary World Issues Environmental Hazards: Air Pollution (ABC-CLIO, 1989); L. Topkina, “Tambora Volcano and the 1815 Eruption,” vulcan.wr.usgs .gov (cited June 2006). DeMond Shondell Miller Joel Yelin Rowan University
Albania
Albania Like other transition nations, Albania has been struggling to reinvent itself economically and politically and to provide a healthy living standard after the fall of the Soviet Union in 1991. Albania’s per capita income of $5,300 makes it one of the poorest counties in Europe. A fourth of the population lives in poverty, and around 11.8 percent of the people subsist on less than $2 a day. Officially, unemployment is reported at 14.3, but unofficial estimates place unemployment at 30 percent. Widespread underemployment also exists. The largest segment of Albania’s economy is derived from agriculture (58 percent of the labor force), which is chiefly subsistence in nature. Regular remittances from abroad, particularly from Greece and Italy, make up from $600 to $800 million of Albania’s total budget. Much-needed resources are drawn away from the social sector by corruption and organized crime. The United Nations Development Programme (UNDP) Human Development Reports rank Albania 73rd out of 177 countries on overall quality-of-life issues. Albania’s government spends 4 percent of its total budget on healthcare, which consumes 6.5 percent of the Gross Domestic Product (GDP). Approximately $366 (international dollars) per capita is allotted for healthcare expenses. Around 42 percent of all healthcare expenses are covered by the government, and 25.1 percent of government funding is earmarked for social security. A portion of government funds is used to pay salaries of personnel in government-sponsored facilities. It is illegal for these medical professionals to accept additional payments from patients. However, 45 to 67 percent of Albanians submit informal payments to ensure a higher quality of service. Consequently, the poorest segment of the population lacks sustained access to quality healthcare. The private sector provides 58.3 percent of healthcare funding, with 99.80 percent of that funding deriving from out-of-pocket expenses. There are approximately 1.31 physicians, 3.62 nurses, 0.59 percent midwives, 0.45 percent dentists, and 0.40 pharmacists per 1,000 population in Albania. The population of 3,581,655 has a life expectancy of 77.43 years, and females generally outlive males by four years. There is a good deal of disparity between male (93.3 percent) and female (79.5 percent) literacy in Albania. Approximately 95 percent of all children are enrolled in school at the primary level. Attendance drops
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to 81 percent at the secondary level, partially because 23 percent of Albanian children between the ages of 5 and 14 are in the labor force. Technically, only 1 percent of urban residents and 5 percent of rural residents lack access to safe drinking water. However, less than one-half of the population has running water inside the home. One percent of the urban population and 19 percent of rural residents lack access to improved sanitation. Three-fourths of Albanian women use birth control. Fertility is relatively high at 2.03 children, partially because of the need for free labor on family farms. Albania has a problem with teenage pregnancy, and 16 of every 1,000 live births involve adolescent mothers. Only 2 percent of all births occur without the presence of trained attendants, and 91 percent of mothers receive antenatal care. The adjusted maternal mortality rate is 55 deaths per 100,000 live births. Infant mortality is likewise high at 20.75 deaths per 1,000 live births. However, the government has successfully reduced infant mortality. Between 1970 and 1990, the death rate per 1,000 live births fell from 45 to 19. During that same period, the death rate of under-5s dropped from 37 to 17. Three percent of all Albanian infants are underweight at birth, and 14 percent of under-5s fall into this category. Eleven percent of under5s experience moderate to severe wasting, and over a third of this age group experiences stunting. The government subsidizes 60 percent of required infant vaccines, and the international community is involved in the childhood immunization program. Consequently, 99 percent of infants are immunized against hepatitis B, and 98 percent are vaccinated against diphtheria, pertussis, and tetanus (DPT1) and polio. Ninety-seven percent are vaccinated against tuberculosis and DPT3; and 96 percent are immunized against measles. More than half of all children under the age of 5 receive oral rehydration treatment when necessary. The public health system in Albania has shifted its focus from guaranteeing basic health standards and eradicating the causes of infectious, toxic, and traumatic diseases to dealing with chronic diseases of lifestyle and behavior. SEE ALSO: Healthcare, Europe. BIBLIOGRAPHY. Central Intelligence Agency, “Albania,”
World Factbook, www.cia.gov (cited January 2007); Martin A. Levin and Martin Shapiro, eds., Transatlantic Policy-
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making in an Age of Austerity: Diversity and Drift (Georgetown University Press, 2004); Enver Roshi, et al., “Building Public Health Allocations in the Transition Countries of Eastern Europe: The Example of Albania,” European Journal of Public Health (v.16/243–245, 2006); United Nations Children’s Fund (UNICEF), “Albania,” www.unicef.org (cited January 2007); Taryn Vian and Lydia J. Barak, “Beliefs about Informal Payments in Albania,” Health Policy and Planning (v.21/5, 2006); World Bank, “Albania Data Profile,” www.southeasteurope.org (cited January 2007); World Health Organization, “Albania,” www.who.int (cited January 2007); Raymond E. Zickel and Walter R. Iwaskiw, Albania: A Country Study (Federal Research Division, 1994). Elizabeth R. Purdy, Ph.D. Independent Scholar
Alcohol and Youth Each day in the United States, 7,000 youth under the age of 16 take their first drink. The media has been flooded with alcohol-related tragedy in youth, a statistic that is apparently rising. Some of the most important new data to emerge on young adult drinking were collected through a recent nationwide survey, the National Epidemiologic Survey on Alcohol and Related Conditions (NESARC). According to these data, in 2001–2002 about 70 percent of young adults in the United States, or about 19 million people, consumed alcohol in the year preceding the survey. Furthermore, research has indicated that the heaviest drinking usually takes place during the late teens and early 20s. The issue becomes increasingly troublesome because NESARC data indicate that binge drinking is also the most common in this age group. Binge drinking was defined by the study as consuming five or more drinks in a row at least once over the past month. It has been recommended that alcohol consumption be limited to no more than two standard drinks for men or one drink for women per day. A standard drink is defined as one 12-ounce bottle of beer, one 5-ounce glass of wine, or 1.5 ounces of distilled spirits. Information from NESARC and the National Institute on Alcohol Abuse and Alcoholism (NIAAA) indicates that approximately 46 percent of young adults (12.4 million) in the United States en-
Alcohol use is exacerbated by certain mood disorders (depression, anxiety, mania) and stresses prevalent among this age group.
gaged in drinking that exceeded the recommended daily limits at least once in the past year, and 14.5 percent (3.9 million) had an average consumption that exceeded the recommended weekly limits. The rise in alcohol-related traffic fatalities and crime is being attributed to the rising prevalence of risky drinking behavior. In 2003, 32 percent of drivers aged 16–20 who died in motor vehicle accidents had detectable levels of alcohol in their blood. This number increased to 51 percent for drivers aged 21– 24. There is, therefore, a clear relationship between young adult drivers and drinking, making them a serious public health threat to others and themselves. Alcohol and Development Adolescence is a time marked by change and exploration. The young adult is bombarded with new responsibilities and pressures. Many move out of their parents’ homes for the first time and go live with their peers. They go to college or start a job, and often begin new
and serious relationships that often include new sexual experiences. And in the process of constantly battling with their own identities and how they fit in the world, they are suddenly free to make decisions without any parental censorship or guidance. For a variety of other social and cultural reasons, the availability and interest in consuming alcohol rises during this period. Stress has also been identified as a potent factor leading to the development of unhealthy behaviors such as drinking. The brain continues to develop throughout adolescence and well into young adulthood. This has many researchers concerned about the impact drinking will have on this critical period of development. Many believe that it may lead to lifelong impairments in brain function, particularly as it relates to memory, motor skills, and coordination. The findings are not generalizable, however, as many past drinkers have not experienced these deficits. Many environmental and genetic factors exist that have been shown to influence the risk and variable outcomes of alcohol exposure. Influences and Prevention A recent national survey in the United States reported that men are much more likely than women to drink in a harmful manner. From the ages of 19–30, 45 percent of men and 26.7 percent of women reported heavy drinking, which was defined by the study as five or more drinks on one occasion. Similarly, racial, ethnic, and cultural differences in drinking and alcohol-related problems have been documented. In general, white and Native American young adults drink more than African Americans and Asians, and drinking rates for Hispanics fall in the middle. The ethnographic differences are important to consider: For whites, heavy drinking is a part of a youthful lifestyle, whereas Hispanics tend to see heavy drinking as a “right” they earn when they reach maturity. Studies examining college students found that although college students tend to drink heavier when they drink, the prevalence in young adults exists regardless of whether they attend college. Military culture tends to be accepting of alcohol use, and in 2002, a survey found that 27 percent of servicemen aged 18–25 reported heavy drinking, compared with 8.9 percent of those aged 26–55. Regardless of context, the phenomenon of perceived social norms—or the belief that “everyone” is drinking and drinking is acceptable—is one of the strongest correlates of drinking among young adults.
Alcohol and Youth
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Personality traits such as impulsivity, risk taking, and feelings of invincibility have also been associated with increased alcohol use. Many young people feel impervious to any negative consequences that might occur because of drinking. This is exacerbated by certain mood disorders (depression, anxiety, mania) and stresses prevalent among this age group. Children model their behavior after their parents, and this extends to alcohol consumption. The family structure and type of parenting are also important influences in a child’s development. However, the possibility of a hereditary source for heavy alcohol consumption cannot be undervalued. Researchers from the Collaborative Study on the Genetics of Alcoholism (COGA) recently published reports of several genes associated with alcohol dependence in adults. If an association exists between these genes and adolescent drinking behavior, then scientists may be able to begin teasing apart the complex interplay between genetics and environment. Young adults have been shown to be at increased risk for heavy alcohol consumption. However, the direction each takes in life and the respective influences they are exposed to can differ drastically. Thus, prevention efforts must be multifaceted in approach. Many American colleges, for example, have implemented alcohol-free policies that have been shown to reduce the likelihood of binge drinking and dangerous alcohol-related behavior. The military has attempted similar strategies. Some of the most aggressive interventions have been in the area of drinking and driving. The “zero-tolerance” law strictly limits a young driver’s blood alcohol content to zero and has been adopted by all states. This has led to a 19-percent reduction in drinking and driving and a 20-percent reduction in fatal motor vehicle accidents among young drivers. However, the best approach to reducing harmful drinking and alcohol-related problems in young adults is likely through community action: A young person’s surroundings, culture, and overall social acceptance of alcohol remain prevailing influences. SEE ALSO: Adolescent Development; Adolescent Health;
Alcohol Consumption; Alcoholism.
BIBLIOGRAPHY. R.M. Bray, et al., 2002 Department of De-
fense Survey of Health-Related Behaviors among Military Personnel (RTI International, 2003); R. Caetano and L.A.
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Kaskutas, “Changes in Drinking Patterns among Whites, Blacks, and Hispanics, 1984–1992,” Journal of Studies on Alcohol (v.56, 1995); C.M. Chen, M.C. Dufour, and H.Y. Yi, “Alcohol Consumption among Young Adults Ages 18–24 in the United States: Results from the 2001–2002 NESARC Survey,” Alcohol Research & Health (v.28/4, 2004/2005); S. Hiller-Sturmhöfel and H.S. Swartzwelder, “Alcohol’s Effects on the Adolescent Brain: What Can Be Learned from Animal Models,” Alcohol Research & Health (v.28/4, 2004/2005); R. Hingson, et al., “Magnitude of Alcohol-Related Mortality and Morbidity among U.S. College Students Ages 18–24: Changes from 1998 to 2001,” Annual Review of Public Health (v.26, 2005); T.S. Naimi, et al., “Binge Drinking among U.S. Adults,” Journal of the American Medical Association (v.289, 2003); Substance Abuse and Mental Health Services Administration, Results from the 2004 National Survey on Drug Use and Health: National Findings, www.oas.samhsa.gov (cited March 2006); S.F. Tapert, L. Caldwell, and C. Burke, “Alcohol and the Adolescent Brain: Human Studies,” Alcohol Research & Health (v.28/4, 2004/2005); A.M. White and H.S. Swartzwelder, “Hippocampal Function during Adolescence a Unique Target of Ethanol Effects,” Annals of the New York Academy of Sciences (v.1021, 2004); H.R. White, E.W. Labouvie, and V. Papadaratsakis, “Changes in Substance Use during the Transition to Adulthood: A Comparison of College Students and Their Noncollege Age Peers,” Journal of Drug Issues (v.35, 2005); H. Yi, G.D. Williams, and B.A. Smothers, Trends in Alcohol-Related Fatal Traffic Crashes: United States, 1977–2002, Surveillance Report No. 69 (National Institute on Alcohol Abuse and Alcoholism, 2004). Jared Daniel Ament Independent Scholar
Alcohol Consumption Alcohol is a part of nearly every human society, finding its place in religious ceremonies and celebrations, and on the dinner table. From the viewpoint of those not working in health professions, alcohol is a social entity, a core element distinguishing one’s culture. However, for clinicians, alcohol is also a medical entity, a toxin whose abuse leads many patients to unnecessary morbidity and mortality.
Across world cultures, alcohol plays a diverse number of roles. Although prohibited in Islamic and Seventh-Day Adventist religious communities, it is central to religious ceremonies and celebrations in many others. A study analyzing the volume of alcohol consumed revealed highest consumption in Europe and North America, with the lowest consumption being in the eastern Mediterranean and southeast Asia. This study also found a discordance between national per capita alcohol consumption and rates of alcohol abuse. Indeed, it appears that alcohol’s disease burden on a society is not predicted by the amount of alcohol in that society. Comparing countries in Europe, for example, there was a 10-fold difference in alcohol attributable premature deaths (AAPD), despite comparable national rates of consumption. Alcohol’s gender role also differs across cultures, with rates of use and abuse varying widely. However, consistently across cultures, males are more likely to develop alcohol dependence and are approximately twice as likely to suffer AAPD than females. Harms and Benefits The potentially harmful aspects of alcohol are well known, representing the majority of medical and societal campaigns directed at alcohol. More specifically, we know that overuse of alcohol, both acute and chronic, can cause harm. Acutely, alcohol consumption impairs reaction time and critical thinking abilities at blood alcohol levels of 0.03 mg/dl and higher. As a result, the person is at higher risk for motor vehicle crashes; in the United States, 40 percent of traffic fatalities are alcohol related. Those who drink excessive amounts of alcohol also suffer adverse consequences related to poor decision making and disinhibition, both of which are effects of alcohol. In addition, severe intoxication with alcohol can lead to blood alcohol levels high enough (e.g., 40–50 mg/dl) to cause coma, stupor, or death. Chronically, alcohol overconsumption can cause a wide range of consequences, including cognitive impairment, peripheral neuropathy, myopathy, and liver dysfunction. However, there is increasing evidence that alcohol, when consumed in moderation, is both relatively benign and may have potential health benefits. Regarding the former position, the two sources of the medical evidence on alcohol, the study of the acute physiological effects of consumption and observational studies
Alcoholism
comparing abstainers with alcohol users, have made it difficult to extrapolate whether there are negative consequences for healthy users of moderate amounts of alcohol. However, we do know that alcohol is not benign in certain populations—for example, in pregnant women, those with family histories of alcoholism, and persons with hepatic/pancreatic disease, there is no harmless dose of alcohol. As for whether alcohol consumption can be beneficial, the evidence suggests that for healthy persons without conditions contraindicating alcohol, 0.5 to 1 portion of alcohol per day (1 portion = one glass of wine, one can of beer) may have health benefits. A large study of nurses showed that those who consumed moderate amounts of alcohol had decreased mortality rates compared to those abstaining from alcohol. This finding is consistent with prospective studies from around the world, which have shown that relative risk of death for moderate drinkers, compared to abstainers, is 0.6 to 0.9. Ecological studies conclude the same, the most well known of which is the “French paradox” (the low rates of heart disease in France despite a high-fat diet, theorized to be attributable to high red wine consumption). It appears that the mechanism for this effect is the beneficial effect of alcohol on coronary heart disease; thus, those individuals at highest risk for heart disease appear to benefit the most. SEE ALSO: Alcohol and Youth; Alcoholism. BIBLIOGRAPHY. C. Fuchs, et al., “Alcohol Consumption
and Mortality among Women,” New England Journal of Medicine (v.332/19, 1995); K. Mukamal, “Overview of the Risks and Benefits of Alcohol Consumption,” UpToDate, www.uptodate.com (cited January 2007); National Highway Traffic Safety Administration, “Traffic Safety Facts 2000: Alcohol,” www.nhtsa.dot.gov (cited March 2005); J. Rehn, et al., “The Global Distribution of Average Volume of Alcohol Consumption and Patterns of Drinking,” European Addiction Research (v.9, 2003); U.S. Department of Agriculture/U.S. Department of Health and Human Services, Home and Garden Bulletin No. 232. Nutrition and Your Health: Dietary Guidelines for Americans, 3rd ed. (U.S. Government Printing Office, 1990). Anthony Fleg University of North Carolina
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Alcoholism Worldwide, alcoholism is a leading preventable cause of morbidity and mortality. The chronic effects of alcohol overuse are destructive to bodily organs, families, and communities alike. Although the numbers of persons consuming alcohol is great, constituting a majority of the population in certain cultures, a small minority of these will develop problems with alcohol. Alcoholism is defined by the U.S. National Council on Alcoholism and the American Society of Addiction Medicine as a “primary chronic disease with genetic, psychosocial, and environmental factors influencing its development and manifestations.” The criteria for alcoholism, as defined by this group, are as follows: • impaired control over drinking • preoccupation with the drug alcohol • use of alcohol despite adverse consequences • distortion of thinking, most notably denial The term alcoholism encompasses the Diagnostic and Statistical Manual, 4th edition (DSM-IV) definitions of alcohol abuse and dependence, terms used to more clearly define types of alcoholism. Both are characterized as maladaptive patterns of alcohol abuse, with separate criteria. Alcohol abuse involves one or more of the following: • failure to fulfill work, school, or social obligations; • recurrent substance use in physically hazardous situations; • recurrent legal problems related to substance use; • continued use despite alcohol-related social or interpersonal problems. Alcohol dependence involves three or more of the following: • tolerance • withdrawal • substance taken in larger quantity than needed • persistent desire to cut down or control use • time is spent obtaining, using, or recovering from the substance • social, occupational, or recreational tasks are sacrificed • use continues despite physical and psychological problems The three definitions—alcoholism, alcohol abuse, and alcohol dependence—all represent maladaptive
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use of alcohol that compromise the ability to function and fulfill obligations. While the distinctions between the three are useful in research, they are often indistinguishable in the clinical setting. Moreover, because they are treated similarly, health professionals will often focus on developing an individualized treatment plan based more on individual needs, rather than the diagnostic category. In addition, while the three overlap in many individuals, a unique feature of alcohol dependence is worth mentioning. In contrast to alcohol abuse, alcohol dependence involves signs of physiological dependence on alcohol characterized by an inability to quit or decrease usage of alcohol, despite a desire to do so. This article will use the convention chosen by many and will define alcoholism to be the disease of alcohol abuse and/or dependence, as outlined by the DSM-IV criteria. Epidemiology Although many societies treat “alcohol use” as a socially accepted norm, making it commonplace, the
A molecule known as CRF has recently been implicated in a possible biological mechanism connecting stress and alcoholism.
abuse of alcohol is often found concentrated in specific segments of the population. Data from primary care patients suggest that prevalence rates of alcohol abuse/dependence can approach 10 percent of the population. Persons at the youngest and oldest ends of the age spectrum appear to be the most at risk for alcohol problems. For young adults 18–25 years of age, the group for whom binge and heavy drinking rates are the highest in the United States, the risks and costs of alcoholism throughout their lifetime are both acute and long term. Acute risks for this age group include alcohol-related motor vehicle crashes and violence. Longer-term effects are also great owing to their young age, and the fact that they are still developing physically and emotionally. One study in the United States, where laws require persons to be 21 years of age to consume alcohol, revealed that young persons who initiated alcohol use before the age of 21 were four times more likely to become alcoholics over their lifetime when compared to those who began drinking alcohol at age 21. For older patients, unique problems associated with alcoholism include comorbid medical conditions and drug–alcohol interactions. Two other populations known to have high rates of alcoholism are smokers and those with mental illness. In the case of smokers, 30 percent of those who smoke suffer from alcoholism, while 90 percent of alcoholics smoke. Different studies in the United States have shown that those with mental illness are more likely to have problems with alcohol, and vice versa. Current evidence suggests that approximately 40 percent with one of the two problems will also have the other (e.g., 40 percent of those diagnosed with mental illness will have problems with alcohol, while 40 percent of those with alcohol disorders will have diagnosable mental illness). Long before there was rigorous science to back up a mechanism for alcoholism, it was clear that this condition had both a biological and social aspect. It is now known that alcohol is an antagonist to NMDA receptors, and an agonist at GABA receptors. Downstream from these receptors, alcohol affects many pathways, including the dopamine reward pathways. Recently, a molecule involved in stress responses, CRF, has been implicated as a mediator in the alcohol–GABA relationship, suggesting a biological mechanism connecting stress and alcoholism.
Beyond our ever-increasing understanding of the mechanisms behind alcohol addiction, there is also increasing evidence for a genetic basis to the disease. First-degree relatives of alcoholics have a relative risk for alcoholism three- to fourfold that of those without alcoholic relatives. In addition, a large populationbased twins study found that identical twins have greater rates of concordance with regard to alcoholism than do fraternal twins; the authors estimate that approximately 50 to 64 percent of the variation between twins was explained by differences in addictive genetic factors. Pathological Effects of Alcohol Alcoholism is a costly societal condition. Estimates from Europe suggest an excess annual cost of €1,431 in 2003 for those with alcoholism, mostly due to decreased production. Another study estimated the cost to the United States in 1998 for alcoholism to be $185 billion, a result of the lost productivity, treatment, and comorbidities associated with alcoholism. Although these numbers are staggering, there are many costs to alcoholism that cannot be quantified, including the suffering of family members and the lost potential of the alcoholic. In addition, even though the statistics linking alcohol use with crime, violence, motor vehicle crashes, suicide, and drowning are direct indicators of alcohol’s societal costs, it is certain that alcoholism puts persons at risk to themselves and others through a perpetual overuse of alcohol. Alcohol also has devastating effects on the body of the alcoholic. Chronic alcohol overuse affects nearly all of the body’s organs and organ systems. The nervous system effects of alcoholism are particularly devastating. Wernicke’s encephalopathy (WE), a condition seen in alcoholics due to low thiamine levels causes confusion, disorientation, and other signs of encephalopathy, oculomotor dysfunction, and gait ataxia. Korsakoff ’s amnestic syndrome is often seen in patients who have already experienced WE, especially WE due to alcohol. It is marked by selective memory deficits (retrograde and anterograde), apathy, and an intact sensorium. Beyond these specific deficits, there are also global changes found in alcoholics, with more than half showing deficits on neuropsychological testing; this corresponds with widespread changes to the brain, namely the enlargement of the ventricles, that is
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seen with chronic alcohol abuse. Other categories of nervous system dysfunction found disproportionately in alcoholics include cerebellar degeneration, damage to the corpus callosum, peripheral neuropathy, and myopathy. The gastrointestinal (GI) system is also vulnerable to damage from alcohol. Most prominently affected are the liver and pancreas. Inflammation of the liver due to alcohol, known as alcoholic hepatitis, causes symptoms of nausea, vomiting, and abdominal pain. Over years of such inflammation, this will lead to permanent scarring and necrosis of the liver, a condition known as alcoholic cirrhosis. At this point, the functional capacity of the liver is decreased, and the patient is at risk for liver failure and hepatocellular carcinoma (HPC), not to mention the various sequelae from the liver’s inability to process and eliminate toxins from the body. Chronic ethanol use, even in moderate amounts, is also known to enhance the risks for HPC in carriers of hepatitis B and C. The pancreas is also affected by chronic alcohol use, leading to a similar acute and chronic inflammatory response as is seen in the liver. One in 10 alcoholics will develop acute pancreatitis, with the majority of them progressing to chronic pancreatitis. In addition, cancers of the GI tract also rise with increasing rates of alcohol consumption, and are, therefore, found disproportionately in alcoholics. While the bodies of alcoholics suffer greatly, fetuses exposed to ethanol are especially susceptible to long-term damage. The range of effects from maternal alcohol use vary from severe (fetal death, fetal alcohol syndrome) to mild or nonexistent, depending on many factors. Worldwide, rates of fetal alcohol syndrome, the disorder at the severe end of the spectrum of alcohol-related effects, range from 1 in 100,000 to 1 in 100. Its characteristics include facial abnormalities and central nervous system deficits. Other alcoholrelated effects from fetal exposure include low birth weight, sleep disorders during infancy, learning disabilities, hyperactivity, and low IQ. There are other conditions clearly associated with alcoholism, a few of which are mentioned below. Those conditions for which evidence is unclear (e.g., dementia or lung cancer) are not discussed here. • Breast cancer: Those who drink more alcohol have higher rates of breast cancer, with a dosedependent curve between the two, beginning
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•
• •
Alcoholism at one to two drinks per day. Hormone replacement therapy appears to further enhance alcohol’s effect of breast cancer risk, while high folic acid intake lessens alcohol’s effect. Cancer of the oral cavity, larynx, pharynx, and esophagus: The rates of these cancers rise linearly with increased alcohol use. In addition, smoking has a synergistic effect on cancer risk in those who also use alcohol. Osteoporosis: Alcoholism is related both to more falls and decreased bone mineral density. Diabetes: Through pancreatic damage and the chronic inflammation associated with alcohol, those with drinking problems are at higher risk for diabetes.
Treatment Alcoholism, with the vast aforementioned risks to both individual patients and to the society around them, requires aggressive treatment. There are many options, some of which have been validated in studies of their effectiveness, to treat those with alcohol problems. First, however, the patient must recognize his or her illness, a process that involves both the diagnosis being made and the patient overcoming denial. The medical community has turned to behavioral approaches as primary interventions for alcoholics, recognizing that the behavior patterns associated with this condition must be broken before abstinence from alcohol can be achieved. Alcoholics Anonymous (AA) and similar support groups operate across the world, providing large numbers of alcoholics with “treatment” for their disease. More recently, medications have become available as alternative treatment for alcoholism, with naltrexone currently recommended for patients who need help to maintain abstinence. Two components of all treatment plans for alcoholics deserve mention. First, there is a risk for alcohol withdrawal in those who have developed high levels of alcohol dependence, and therefore, measures are taken to ensure a safe cessation of alcohol. Second, there is no level of alcohol considered “safe” for alcoholics, and therefore, complete abstinence from alcohol is necessary to achieve remission. SEE ALSO: Alcohol and Youth; Alcohol Consumption;
American Academy of Addiction Psychiatry (AAAP).
BIBLIOGRAPHY. American Psychiatric Association, Di-
agnostic and Statistical Manual, 4th ed. (American Psychiatric Association Press, 1994); Centers for Disease Control and Prevention National Center on Birth Defects and Developmental Disabilities, “Fetal Alcohol Spectrum Disorders,” www.cdc.gov/ncbddd (cited January 2007); M. Charness, “Overview of the Chronic Neurologic Complications of Alcohol,” UpToDate, www.uptodate.com (cited January 2007); S.Y. Choi and H. Kahyo, “Effect of Cigarette Smoking and Alcohol Consumption in the Aetiology of Cancer of the Oral Cavity, Pharynx and Larynx,” International Journal of Epidemiology (v.20, 1991); G. Freund, “Chronic Central Nervous System Toxicity of Alcohol,” Annual Review of Pharmacology (v.13, 1973); M. Gold and M. Aronson, “Screening for and Diagnosis of Patients with Alcohol Problems,” UpToDate, www.uptodate.com (cited January 2007); D.S. Hasin, et al., “Epidemiology of Major Depressive Disorder: Results from the National Epidemiologic Survey on Alcoholism and Related Conditions,” Archives of General Psychiatry (v.62, 2005); A.C. Heath, et al., “Genetic and Environmental Contributions to Alcohol Dependence Risk in a National Twin Sample: Consistency of Findings in Women and Men,” Psychological Medicine (v.27, 1997); P.R. Martin, et al., “Alcoholic Organic Brain Disease: Nosology and Pathophysiologic Mechanisms,” Progress in Neuro-Psychopharmacology & Biological Psychiatry (v.10, 1986); R.M. Morse and D.K. Flavin, “The Definition of Alcoholism,” Journal of the American Medical Association (v.268, 1992); K. Mukamal, “Overview of the Risks and Benefits of Alcohol Consumption,” UpToDate, www.uptodate.com (cited January 2007); H. O’Connell, et al., “Alcohol Use Disorders in Elderly People—Redefining an Age Old Problem in Old Age,” British Medical Journal (v.327, 2003); D.A. Regier, et al., “Comorbidity of Mental Disorders with Alcohol and Other Drug Abuse. Results from the Epidemiologic Catchment Area (ECA) Study,” Journal of the American Medical Association (v.264/19, 1990); F. Smit, et al., “Costs of Nine Common Mental Disorders: Implications for Curative and Preventive Psychiatry,” Journal of Mental Health Policy and Economics (v.9/4, 2006); UCLA Center for Advanced Endoscopy and the Pancreatobiliary Center, “Alcohol-Induced Pancreatitis,” www.ercp.ucla.edu (cited January 2007); U.S. Department of Health and Human Services (DHHS), Healthy People 2010, conference ed. (DHHS, 2000). Anthony Fleg University of North Carolina
Allele
Algeria Algeria is located in north Africa between Libya, Tunisia, and Morocco and is the second largest country on the continent. Seized as a French colony in 1830, it launched a violent bid for independence in 1954 and was finally surrendered by the French in 1962. Subsequent governments were unable to build a social and political structure that pleased the various cultural and religious factions within the country. In 1992, civil war broke out between the National Liberation Front (FLN) and the Islamic Salvation Front (FIS). By the time the FIS was disbanded in 2000, more than 100,000 Algerians were dead. Low-level Islamic insurgency continues today. The population of Algeria is now approximately 3,333,000, and is growing at a rate of 1.22 percent annually. The birth rate is 17.11 per 1,000 population, with a death rate of 4.62 per 1,000 population. Median age is 25.5 years. The current life expectancy is 71.91 years for males and 75.21 years for females. Gross national income is low at US$2,730 per capita, and 25 percent of the population live under the poverty line. Sixty percent of Algerians live in urban areas, and the economy is dominated by natural gas and oil production along the coast. Algeria does not suffer from a large number of communicable diseases. The country lies north of the malaria zone and has about 450 cases a year. There is a high risk of cutaneous leishmaniasis in some regions. Trachoma, a degenerative eye infection that can lead to blindness, is common in rural areas. Sanitation is generally good, with 85 percent of the population able to access clean water and 92 percent using sanitary waste facilities. There are, however, some outbreaks of diarrhea, typhoid fever, and hepatitis A. In 2003, the country suffered its first outbreak of the plague since 1950. There were 11 confirmed and seven suspected cases and one known fatality. HIV/AIDS has not emerged as a major threat in Algeria, with an adult prevalence rate of 0.1 percent. About 19,000 Algerians have contracted the virus, and slightly over 500 have died. The government has shown a high level of commitment to treatment and prevention, but educational programs are lagging to some degree, and a large number of vulnerable young people do not yet understand the basics of prevention. Noncommunicable diseases cause the most problems for Algerians, causing 66 percent of deaths each
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year. Cardiovascular disease is the cause of more than 50 percent of all deaths. Cancers cause another 20 percent. Lifestyle surveys show that most Algerians stay away from alcohol and over 55 percent get their full five servings of fruits and vegetables each day. But on the negative side, 32.3 percent of men smoke daily, and 21.4 percent of women have a high body mass index. The diabetes rate is around 6 percent. The health of women and children has improved since the end of the civil war. Infant and child mortality has fallen, with 34 deaths per 1,000 births in infants under the age of 1, and 39 death per 1,000 for children between the ages of 1 and 5. Use of contraceptives among women has risen to 57 percent, and the fertility rate is 1.86 children per woman. Eighty-one percent receive prenatal care and 96 percent give birth with the help of trained assistants. The maternal mortality rate is 140 deaths per 100,000 live births. Immunization rates have risen for children, and more girls are going to school. However, 25 percent of children go to work between the ages of 5–14, especially in rural districts. Algeria devotes 3.6 percent of its Gross Domestic Product to health and spends about US$94 per capita. The country has a large pool of medical professionals, including more than 35,000 doctors and 62,000 nurses. Despite these factors, the health system is overburdened and poorly organized outside the cities. Many people choose to go to traditional healers to meet their health needs. See Also: Healthcare, Africa; Libya; Morocco; Tunisia. Bibliography. Central Intelligence Agency, “Algeria,”
World Factbook, www.cia.gov (cited June 2007); Joint United Nations Programme on HIV/AIDS, “Algeria,” www.unaids.org (cited June 2007); UNICEF, “Algeria—Statistics,” www.unicef.org (cited June 2007); World Health Organization, www.who.int (cited June 2007). Heather K. Michon Independent Scholar
Allele An allele or allelomorph is one of the variant forms of a gene at a particular locus, or location, on a chromosome. Different alleles produce variations in the
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phenotype of inherited characteristics such as hair color or blood type. Ultimately, virtually all allelic variation arises from differences in DNA base sequence: Either directly in the locus coding for a protein or indirectly through a distant locus, known as the promoter, which is responsible for controlling the level of expression of the gene. Alleles are normally inherited from parents, although acquired mutation can give rise to alleles not present in either parent. Regardless of how they come to be, allele effects can be classified according to a handful of rules. An allele is said to be “dominant” if the presence of one copy of the allele (out of a possible two) is sufficient to determine phenotype. Conversely, a “recessive” allele must be present in two copies in order to affect phenotype. In reality, there are many alternate states that may violate this simple dichotomy. Codominance exists when two different alleles, present concurrently, both act to determine phenotype. The ABO blood type system is a prime example of codominance where the AB blood type is caused by simultaneous expression of alleles for both A and B antigen. Incomplete dominance exists when heterozygotes (those with two different alleles of a gene) exhibit a phenotype intermediate to the homozygous phenotypes of the two alleles. Finally, incomplete penetrance explains the phenomena where individuals with a particular set of alleles fail to show the phenotype classically associated with that allele. SEE ALSO: Base Sequence; Chromosome; DNA; Geno-
type; Heterozygote; Homozygote; Phenotype; Point Mutation; Somatic Mutation. BIBLIOGRAPHY. R.L. Nussbaum, et al., Thompson &
Thompson: Genetics in Medicine, 6th ed., revised reprint (Saunders, 2004); Minou Bina, ed., Gene Mapping, Discovery, and Expression: Methods and Protocols, (SpringerVerlag, 2006). Bimal P. Chaudhari Boston University
Allergy Allergy is an inflammatory disorder of hyperreactivity of the immune system against common envi-
ronmental exposures. The prevalence of allergy is increasing, both in industrialized and developing nations; the reason for this is unknown. A higher prevalence of allergy is observed in developed nations, as compared with less affluent countries, and migrants to high allergy areas develop allergies in a time-sensitive manner. Access to care is a serious issue with allergy and asthma, leading to higher mortality in places where diagnosis, prevention, and treatment are not readily available. Allergy develops from a combination of genetic factors and environmental exposures, and is also known as atopy, a genetic predisposition toward overreactive immune responses to harmless environmental exposures. Atopy typically includes the atopic triad: asthma, eczema, and allergic rhinitis. Allergies can affect many organ systems, including airways, gastrointestinal tract, eyes, nose, and skin, and can manifest as asthma, food allergy, allergic rhinitis (hay fever), eczema (atopic dermatitis), or hives (urticaria). Normally, the immune system protects the body from invading pathogens by recognizing the microbe and generating protective cells and molecules against it. An allergic reaction is also an immune response, but to nonpathogens. Common allergens include house dust mites; cockroaches; cat and dog dander; plant pollens from trees, grasses, and shrubs; foods such as peanuts, shellfish, and eggs; and medications, such as penicillin. Rural and urban areas contain different allergens. For example, air pollution in cities that are heavily industrialized is known to exacerbate asthma, while chicken feathers, dust, and grass pollen have been identified as common triggers in rural areas. Immunology An allergic reaction is classified as a type I hypersensitivity reaction, characterized by secretion of immunoglobulin E (IgE) antibodies. In an allergic reaction, a person must be previously sensitized to the particular allergen, so that the immune system is able to identify and memorize a specific molecular “footprint” for each allergen. On encountering the allergen for the first time, IgE is produced. These IgE antibodies attach themselves to mast cells, which line the organs of the body, or basophils, which are present in blood. Mast cells and basophils contain granules full of inflammatory molecules, including histamine, leukotrienes, and prostaglandins.
Allergies can affect many organ systems, including airways, eyes, nose, and skin, and manifest in many ways, including hay fever.
Other immune cells also play an important role in allergy and the allergic reaction. Activated B cells (or plasma cells) produce the IgE antibodies selectively in allergic individuals. B cells are also able to make other antibodies (including IgG) against allergens that do not lead to mast cell degranulation but are protective against allergic inflammation. Allergen-specific IgG antibody, but not IgE, has been found in nonallergic individuals, demonstrating that their immune systems can also recognize and respond to the allergen, but without inducing an inflammatory response. When a previously sensitized person comes in contact with the same allergen for the second time, the allergen crosslinks two or more molecules of IgE on the same mast cell or basophil, leading to degranulation. The release of granules causes the effects of inflammation, either systemically or locally at the site of exposure (lungs, skin, etc.). These can include redness, swelling, itchiness, increased vascular permeability, mucus secretion, and anaphylaxis. T cells are also important in the pathogenesis of an allergic reaction. The immune deviation hypothesis states that allergies can be explained by the balance between type 1 and type 2 T cell activity. Type 2 helper (Th2) T cells produce molecules that prepare, assist, and exaggerate the IgE inflammatory response. The natural function of Th2 cells is to respond to parasites and extracellular bacteria, while Th1 cells respond to viral and intracellular infections. In sev-
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eral models, deviation toward a Th1 response, away from a Th2 response, can prevent development of an allergic reaction. However, Th1 cells can also synergize with Th2 cells to aggravate allergies, so it is not entirely clear that the Th1/Th2 dichotomy or immune deviation fully explains pathogenesis. It has also been shown that nonallergic people have regulatory mechanisms in place to thwart a runaway immune response, while allergic individuals have lower levels of these regulatory cells and molecules. A different type of T cell, which is anti-inflammatory and plays a protective role against allergies, is called a regulatory T cell (Treg). Tregs secrete anti-inflammatory cytokines, which counteract the effects of the proinflammatory molecules. The best-supported hypothesis for the pathogenesis of allergy is that it is due to an insufficient development of allergen-specific Tregs expressing anti-inflammatory molecules. All people develop the same reactions to harmless allergens, but only allergic people are missing the anti-inflammatory brigade that prevents allergic reactions. Hygiene Hypothesis Atopic disease, especially childhood asthma, has increased in prevalence worldwide since 1980. This increase is most obvious in countries that are rapidly industrializing or becoming westernized. Epidemiologic data and evidence from the immune-deviation hypothesis have given rise to the hygiene hypothesis. Because children get fewer infections in a cleaner, more industrialized age, it has been suggested that Th2 cells are improperly trained in their ability to distinguish harmless and harmful molecules. This results in a hyperresponsiveness of the immune system. The evidence for the hygiene hypothesis mostly consists of epidemiological studies that suggest associations and correlations, rather than causation. Data for specific microorganisms are limited, but three that have a protective effect against asthma and atopic dermatitis are hepatitis A virus, salmonella, and helminths/parasites. In addition, studies have shown that enrollment in daycare, having several siblings, growing up on a farm, and exposure to bacterial by-products are all negatively correlated with the development of a positive allergy skin test. However, exposure to pigs in early childhood is correlated with an increase in asthma, and cat ownership increases the risk of developing one of the three atopic diseases.
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Allergic Rhinitis Allergic rhinitis is inflammation of the eyes, nose, and throat upon exposure to an allergen. Mucus secretion, itchy, watery eyes, and frequent sneezing are the hallmarks of allergic rhinitis, also known as hay fever. Skin-prick testing is the gold standard for diagnosis, proving effective in over 80 percent of allergic rhinitis patients tested. Small amounts of common allergens are scratched onto the skin. If the patient is allergic, a red, itchy wheal will appear on the skin within 30 minutes, which can be detected as evidence of a specific allergy. Levels of IgE in the blood are often used as a diagnostic tool in clinics, but a recent study has shown that IgE titer varies between individuals, so that a single blood serum IgE level is not indicative of allergenicity of an individual. In areas without primary care clinics, allergic rhinitis can be diagnosed by noting seasonal variations and the common exposures that trigger a reaction. Treatments for allergic rhinitis include antihistamines, intranasal steroids to suppress inflammation, and air filters, which have shown mild benefit in reducing indoor allergens. In addition, immunotherapy, involving subcutaneous administration of increasing doses of allergen over a three-to-five-year period, has been shown to cure individuals of their allergies. The mechanism is thought to induce production of protective IgG antibodies as well as expansion of protective anti-inflammatory Tregs that are specific to each allergen. Where immunotherapy is not available, identification and avoidance of the triggering allergen(s) is important. Asthma Asthma is a chronic respiratory disease characterized by attacks of difficulty breathing. Around 300 million people in the world have asthma, and an estimated 400 million will have it by 2025. Not all asthma is related to allergy, but allergies are a common trigger for asthma attacks, as are infections, exercise, cold weather, and environmental exposure to respiratory irritants. Asthma is diagnosed by a lung function test that measures the volume and force of air entering and leaving the lungs. Leukotriene receptor antagonists have shown effectiveness in asthmatics with allergic rhinitis, and leukotriene receptor antagonists and antihistamines are more effective when used together
than either alone. Where treatment and management options are limited for asthma, it can be life threatening. Triggers such as allergens and air pollution should be avoided if possible. Atopic Dermatitis (Eczema) Atopic dermatitis is a chronic inflammatory skin disease that usually begins in early infancy. The rash itself is extremely itchy and is usually located on the inside surface of elbows and knees, as well as the cheeks of infants and hands and feet of older children and adults. The disease only develops where the skin is scratched, earning this disease the name the itch that scratches. Eczema is the fastest growing of all atopic diseases. A high percentage of patients with eczema have positive skin tests to dietary and environmental allergens, and associated atopic disease (asthma, allergic rhinitis) often develops in children with eczema. The prevalence of food allergy in this population is significantly higher than in the general population. Treatments for eczema include topical corticosteroids, oral steroids, T cell immunosuppressant topical creams, and avoidance of allergy-inducing foods. Anaphylaxis Anaphylaxis is a systemic reaction to an allergen that can lead to hives, constriction of airways, and even death. Common triggers for anaphylaxis are insect stings from the Hymenoptera family (bees, wasps), penicillin and vancomycin allergy, and food allergy, such as tree nuts or shellfish. Portable epinephrine is the best immediate treatment for an onset of anaphylaxis, while immunotherapy have been shown to be highly effective in preventing subsequent systemic reactions. In areas where epinephrine (adrenalin) is not available, avoidance of triggers is important but often difficult. Genetic Factors and Epidemiology Allergy develops from childhood, and around 50 percent of asthma and allergy are thought to be due to genetic factors. Forty to 50 percent of newborns with two atopic parents develop atopic disease, while 20 to 30 percent with single atopic heredity and 10 percent of newborns with no atopic heredity develop some form of the atopic triad. Children are sensitized to allergens in the order in which they are exposed: food, indoor allergens, then
Allograft
outdoor allergens. In infancy, the early signs of atopy are generally eczema, gastrointestinal symptoms, and frequent wheezing. In later childhood, allergy generally manifests as bronchial asthma and allergic rhinitis. Socioeconomic Status When healthcare is intermittent or absent, asthma and allergic anaphylaxis are life-threatening conditions. In addition, epidemiological studies have demonstrated a higher prevalence in atopic diseases that correlates with increasing industrialization of a nation and westernized lifestyle of its population. In a study done on Nigerian and Australian children, it was found that with similar levels of atopy, children living in Australia were at a higher risk for asthma. Also, immigrants to countries with high rates of atopy acquire allergies in a time-dependent manner, according to the age they were when they moved. Vaccination rates, ethnicity, environment, and previous infections do not affect this acquisition of allergic sensitization. However, the International Study of Asthma and Allergies in Childhood (ISAAC) has demonstrated a wide range of worldwide prevalence of asthma, allergic rhinitis, and eczema, not always parallel to a nation’s level of industrialization. The commonly cited link between high socioeconomic status and atopic disease has not been conclusively proven. In studies from the United Kingdom, it was found that there was a higher prevalence of asthma among children in families of high socioeconomic status. One explanation of this is the hygiene hypothesis, that upper-class families live in cleaner conditions. However, an Australian study showed no statistically significant relationship between asthma incidence and social class, and ISAAC data also have not shown this link. It is possible that previous studies linking atopy to elevated socioeconomic status suffered from reporting bias, from less exposure to clinical medicine and less familiarity with the diagnoses. When polled about severe asthma, as opposed to moderate, children in families with low income had high levels. SEE ALSO: Asthma; Asthma in Children; Disease and Pov-
erty; Food Allergy.
BIBLIOGRAPHY. Lara J. Akinbami, “The State of Childhood
Asthma, United States, 1980–2005,” Advance Data from Vital and Health Statistics, Centers for Disease Control and
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Prevention (v.381, 2006); International Study of Asthma and Allergies in Childhood (ISAAC), isaac.auckland.ac.nz (cited February 2007); D. Umetsu and R. DeKruyff, “The Regulation of Allergy and Asthma,” Immunological Reviews (v.212, 2006); David Werner, Where There Is No Doctor: A Village Health Care Handbook (Hesperian Foundation, 2006). Erin Fitch Oregon Health & Science University
Allograft An allograft, also known as an allogenic transplant, refers to a medical situation when cells, tissues, and organs used in operations have been sourced from a genetically nonidentical member of the same species. This is common with transplants when tissue and organ are taken from a donor and transferred to a recipient, most often someone unrelated to the donor, although obviously of a compatible blood type. This is common practice with skin transplants and also transplants of corneas, hearts, livers, kidneys, and bone and bone marrow, although transplants for the last often come from relatives. Isografts are when tissue or organs are transplanted from a genetically identical donor, such as an identical twin, with autograft being when tissue is transplanted from one site on a patient to another, such as for skin grafts after melanomas and so forth caused by skin cancer. There can also be xenografts, where transplants are made from another species. SEE ALSO: Heart Transplantation; Kidney Transplanta-
tion; Liver Transplantation; Lung Transplantation.
BIBLIOGRAPHY. Andrei A. Czitrom, Allografts in Ortho-
pedic Practice (Williams & Wilkins, 1992); Garry E. Friedlaender, Bone and Cartilage Allografts: Biology and Clinical Applications (American Academy of Orthopaedic Surgeons, 1991); Ralph M. Steinman, ed., Mechanisms of Host Resistance to Infectious Agents, Tumors and Allografts (Rockefeller University Press, 1986); Marshall R. Urist, ed., Clinical Orthopaedics and Related Research (Lippincott, 1985). Justin Corfield Geelong Grammar School, Australia
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Allopathy Modern medicine, as practiced in the United States, has evolved to include licensure for the unlimited scope and practice of medicine to two types of recognized physicians, allopathic (MD) and osteopathic (DO). The terms allopath, allopathy, and allopathic are used to describe a system of medicine in which the use of drugs is directed to producing effects in the body that will directly oppose and so alleviate the symptoms of a disease. These terms are often inaccurate, misleading, and archaic. Allopath and allopathy were actually coined by Samuel Hahnemann, the founder of homeopathy, and were used in a pejorative manner in regard to the conventional practice of “heroic” medicine of the 18th and 19th centuries. Medical treatments often considered standard for the day have long since fallen out of favor as fanciful at best and deadly at worst. Some treatments were based on the humoral theories of phlegm, black bile, yellow bile, and blood. Symptoms were treated without regard for the cause or the natural healing processes inherent to the patient. Fevers, regardless of the etiology, were seen as an overabundance of blood. Patients were treated by phlebotomy, or blood letting. Often, this left the patient more vulnerable or weakened to the point that death followed. Surgeons needed to perform rapidly because there were few effective anesthetics, and more often than not, the procedures involved amputation. With the lack of knowledge of or disdain of the germ theory, “laudable” pus was thought to be a sign of healing when, in fact, it indicated microbe invasion. The pharmacopoeia of the 18th and 19th centuries included poisons such as arsenic, mercury, and strychnine, and heavy metals and addictive components such as opium, belladonna, and alcohol. Allopathic and its derivatives have passed into common usage to mean regular medicine, the traditional form of medical practice. There is sentiment among some MDs that the term allopath and its derivatives are limiting as descriptors of the nature of their practices. They note that these terms have only persisted in the lexicography as a convenient means of distinguishing the system of medicine practiced by MDs from that practiced by osteopathic physicians, who are also licensed for the unlimited scope and practice of medicine as well as for other systems that have either
been assimilated with the allopathic profession (i.e., hydropathy and eclecticism) or may remain limited to licensed practitioners in parts of the United States (i.e., naturopathy and homeopathy). SEE ALSO: Alternative Medicine; Osteopathy. BIBLIOGRAPHY. The Bantam Medical Dictionary (Ban-
tam, 1990); N. Gevitz, Other Healers: Unorthodox Medicine in America (Johns Hopkins University Press, 1988); K.E. Gundling, “When Did I Become an ‘Allopath’?” Archives of Internal Medicine (v.158/20, 1998); W.S. Haubrich, Medical Meanings (American College of Physicians, 1997); S.R. Kottegoda, “Allopathy,” Lancet (v.1, 1983); Stedman’s Medical Dictionary, 27th ed. (Lippincott, Williams, & Wilkins, 2000). Dennis J. Dowling, D.O., F.A.A.O. Independent Scholar
Alpha Error In inferential statistics, we state a null and alternative hypothesis, gather data, and compute statistics to decide whether to accept or reject the null hypothesis. Because we compute statistics on a sample in order to make decisions about a population whose parameters are unknown, there is always some probability that our decision will be incorrect. There are two ways we may be incorrect: We may reject the null hypothesis when it is true, or we may accept the null hypothesis when it is false. The first type of error is known as alpha error, or Type I error. The second type of error is known as beta error, or Type II error. For instance, we might be comparing two groups of children to see if they differ in height: Our null hypothesis is no difference between the group means on height, while our alternative hypothesis is that there is a difference in the group means. If our sample statistics indicated that there was a significant difference in means between the groups, while in the population no difference existed, this would lead us to reject the null hypothesis and commit an alpha error. The probability of an alpha error, also referred to as α (the Greek letter alpha), is set before
Alternative Medicine
analysis begins; the probability most commonly used is 0.05. See Also: Beta Error. BIBLIOGRAPHY. Phillip I. Good and James W. Hardin,
Common Errors in Statistics (and How to Avoid Them), 2nd ed. (Wiley & Sons, 2006); Bernard Rosner, Fundamentals of Biostatistics, 5th ed. (Duxbury, 2000). Sarah Boslaugh BJC HealthCare
Alternative Medicine Alternative medicine uses therapeutic approaches not considered part of traditional medicine, including physical treatments and spiritual and mental approaches to healing. Alternative medicine is distinct from complementary medicine, which is used along with conventional medicine approaches. Complementary and alternative medicine, as defined by the National Center for Complementary and Alternative Medicine (NCCAM), are a group of diverse medical and healthcare systems, practices, and products that are not presently considered to be part of conventional medicine. Alternative medicine originated at least 6,000 years ago. Its most researched sources are traditional naturalistic Hindu medicine (also known as ayurvedic medicine), traditional Chinese medicine, and ancient Roman medicine. These therapies derive from strong beliefs in the healing power of nature. In traditional Hindu medicine, health is based on the balance of three fundamental body elements: breath (vayu or prana), bile (pitta), and phlegm (kapha or slesman) and the treatment of disease is based on restoring the equilibrium of these elements. Traditional Chinese medicine considers disease a result of dissonance between external and internal environments; treatments consist of herbal medicine, acupuncture, and massage. Therapeutic approaches of Chinese medicine are based on principles derived from Eastern philosophy and theories such as yin–yang, qi, and the five elements. Ancient Roman alternative medicine mainly used herbal remedies and marginalized the role of contemporary medicine and physicians.
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Modern Alternative Medicine Statistics show that significant percentages of the populations of developed countries use complementary and alternative medicine. In the United States, according to a 2004 National Institutes of Health survey, 36 percent of Americans used complementary and alternative medicine as a form of therapy (praying for health reasons was not included in these statistics). Women are more likely than men to use complementary and alternative medicine. The trend toward using complementary and alternative medicine and natural compounds has significantly increased in past decades. An important reason for this trend is the belief that these therapies will have fewer side effects. Another important factor is a vision of health as a state of complete physical, mental, and social well-being, not merely the absence of disease. In contrast to conventional medicine, which treats the body like a machine, alternative medicine emphasizes the importance of the balance of mental, physical, and spiritual aspects. Simplicity, availability, and lower prices compared to modern medications also contribute to the use of alternative medicine. There is serious skepticism about the efficacy and safety of alternative medicine compared to conventional medicine. Many previous studies of it were poorly designed and had observer bias. Some skeptics of alternative medicine point to the placebo effect or relief of symptoms based on natural recovery from an illness. There are reports of death based on discontinuing conventional medicine in favor of alternative medicine. Therapeutic approaches NCCAM classifies complementary and alternative medicine therapies into five categories: alternative medical systems, mind–body interventions, biologically based therapies, manipulative and body-based methods, and energy therapies. Acupuncture originated in China more than 2,000 years ago and is one of the oldest and most commonly used medical procedures in the world. Acupuncture involves procedures that stimulate anatomical points on the body by using a variety of techniques. Penetrating the skin with fine needles is the most common technique. Acupuncture, in its original form, was based on beliefs about the circulation of a vital force or energy along specific pathways (meridians) in the human body. Disease is the inappropriate flow of
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this energy through the meridians. This inappropriateness can be in strength, quality, or direction of the energy. Acupuncture points are located along these channels and stimulation of them will change the flow of energy in the body. These acupuncture points are seen to correspond to anatomical structures such as peripheral nerve systems. Aromatherapy uses essential oils and water-based colloids extracted from flowers, herbs, and trees to promote physical, emotional, and spiritual health and balance. It dates back 6,000 years and is defined as the controlled use of plant essences for therapeutic purposes. The medieval Persian physician Avicenna is credited with determining the methods for extracting essential oils from plants. Gattefosse was the first person to use the term aromatherapy to describe the practice. Universal reactions to the chemical properties of certain essential oil scents can evoke calmness or joy, energize or relieve stress, or impact emotions in other ways. From an aromatherapy point of view, the aromas of oils are not in themselves therapeutic; it is the essence of oils and their chemical properties that give them their therapeutic value. Ayurveda is an approach that has been practiced in the Indian subcontinent for more then 5,000 years. Ayurvedic healing includes use of herbs, nutrition, panchakarma cleansing to remove accumulated waste in body and mind, acupressure and oil massage, yoga, sanskrit, and jyotish (vedic astrology). The chiropractic system focuses on the balance between body structure (mainly the spine) and function. It is concerned with the relationship between bone structure function and overall health. The main tool in chiropractic medicine is manipulative treatment. Under the Dietary Supplement Health and Education Act (DSHEA) of 1994, a dietary supplement is defined as a product taken by mouth that contains ingredients intended to supplement the diet. Dietary supplements are considered foods, not drugs. In order for an ingredient of a dietary supplement to be a “dietary ingredient,” it must be one or any combination of the following substances: a vitamin; a mineral; an herb or other botanical; an amino acid; a dietary substance for use by humans to supplement the diet by increasing the total dietary intake, such as enzymes or tissues from organs or glands; or a concentrate, metabolite, constituent, or extract.
Herbal medicine uses plants for healing purposes, rather than as dietary supplements. It involves either oral or topical use of plant extractions. Chinese herbal medicine is the most prevalent ancient herbal tradition currently used. It is based on the yin (cooling) and yang (stimulating) qualities of herbs. Combinations of herbs are used according to the lack or excess of these qualities in the patient. Unlike in conventional drugs, in herbal medicine whole plants are used. It is believed that these combinations of different components are synergistic, so the effect of the whole herb is greater than the effect of its components when used separately in modern drugs. Also, it is believed that toxicity is reduced when using whole plants, though more data is needed to verify this concept. Electric and magnetic fields are part of the spectrum of electromagnetic radiation that extends from static electric and magnetic fields, through radiofrequency and infrared radiation, to X-rays. Magnetic therapy is based on the metaphysical assumption that all illnesses are due to some sort of imbalance or disharmony in energy. The balance or flow of electromagnetic energy must be restored to restore health, and magnets are thought to be able to do this. Another common belief is the effect of magnetic therapy in increasing blood circulation, which has yet to be confirmed. The main principle of the homeopathic doctrine is similia similibus curantur (like shall be cured by like). This principle was mentioned in the writings of Hippocrates, Paracelsus, and other ancient Greek philosophers. According to Samuel Hahnemann, founder of homeopathy, all diseases can be actively cured by the introduction of the second diseased state. In essence, small, highly diluted quantities of medicinal substances are given to cure symptoms. The same substances, if given in higher or more concentrated doses, would actually cause the disease. Massage therapies work muscle and connective tissue to promote relaxation and well-being by enhancing the function of those tissues. In almost all cultures massage therapies are separate parts of complementary and alternative medicine. Massage therapies are used in not only improving blood circulation, but also in psychological and spiritual aspects of health. Different techniques used in massage therapies include effleurage, or soft massage along the length of muscles; petrissage, or pressure applied across the width
of muscles; friction, or deep massage applied by circular motions of the thumbs and fingertips; kneading, or squeezing across the width of muscle; and hacking, such as light slaps or karate chops. Naturopathic medicine is a system of medicine that assists in the restoration of health by following a set of specific rules. A basic assumption is that nature is orderly, and this orderliness is designed to result in ongoing life and well-being. This dependable orderliness is believed to be guided by a kind of inner wisdom or inner power that everyone has. This power guiding internal physical processes that lead to health or disease can be assisted by naturopathic treatments that encompass various aspects of alternative medicine such as nutrition and lifestyle counseling, dietary supplements, herbal medicine, exercise, homeopathy, and traditional Chinese medicine. Osteopathic medicine is considered a part of conventional medicine. One of the key concepts of osteopathic medicine is that structure influences function. If there is a problem in one part of the body’s structure, function in that area, and possibly in other areas, may be affected. Another integral part of osteopathic medicine is emphasis on the body’s innate ability to heal itself. Many of osteopathic medicine’s manipulative techniques are aimed at reducing or eliminating the impediments to proper structure and function, so the self-healing mechanism can assume its role in restoring the person’s health. This system of hands-on techniques helps alleviate pain, restores motion, supports the body’s natural functions, and influences the body’s structure to help it function more efficiently. Qigong is a component of traditional Chinese medicine. In Chinese, the word qigong is composed of two characters, qi and gong. Qi means life energy and gong means daily effort. Everyone is born with qi and has the potential to use qi for many purposes. However, the skill to use qi is acquired through training. Once a person is trained, he or she can use qi for medical self-healing. Qigong practice combines movement, meditation, and breathing techniques to enhance the flow of qi in the body, improve blood circulation, and improve immune functions. Reiki is a Japanese technique for stress reduction and relaxation that also promotes healing. It is based on the idea that an unseen “life force energy” flows through every person and is what causes us to
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A 2004 survey found that 36 percent of Americans used complementary and alternative medicine as a form of therapy.
be alive. If one’s life force energy is low, then one is more likely to get sick or feel stress, and if it is high, one is more capable of being happy and healthy. The word reiki is made of two Japanese words: rei, which means “God’s wisdom or the higher power” and ki, which means “life force energy.” Reiki treats the whole person including body, emotions, mind, and spirit, creating beneficial effects that include relaxation and feelings of peace, security, and well-being. Therapeutic touch is a type of medicine in which a therapist moves his or her hands over the patient’s “energy field,” directing the flow of energy, so that the patient can heal. It is based on the belief that each living thing has a “life energy field” that extends beyond the surface of the body and generates an aura. This energy field can become unbalanced, misaligned, obstructed, or out of tune. The basic premise is that this energy field can be felt and manipulated by making movements that resemble massaging the air a few inches above the surface of the patient’s body. Energy healers also feel that they can transfer some of their own life energy to the patient. These techniques are believed to restore the energy field to a state of balance and proper alignment. The restoration of integrity to the field is thought to make it possible for the body to heal itself. Therapeutic touch was created in the early 1970s by Dolores Krieger, a nurse and
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a faculty member at New York University. She was convinced that the palms are chakras and can channel healing energy. Therapeutic touch is also being practiced worldwide by all kinds of alternative healers and laypeople. Color therapy is another approach to healing that aims to stimulate the patient’s inner resources to aid in the recovery of health. Treatment with color was probably first practiced by ancient Egyptians and was later adapted in ancient Greece, India, and China. It was also practiced in Central America by the Mayans and in North America by Native Americans. In the 20th century, the philosopher and educator Rudolf Steiner (1861–1925) developed some theories of color therapy, which lately have become widely accepted. Although studies have demonstrated that colors have profound effects on the emotional and physical behavior of human beings, many of the theories are still scientifically unproven. In horticultural therapy, plants are utilized as tools for an activity therapy to improve or expand a person’s physical and/or mental well-being. Most of the studies on the benefits of gardening have been supportive to horticultural therapy. Although gardening has been common in many countries throughout history, the first serious research on horticultural therapy was done by Leonard Meager in 1699. His advice was to “spend time in the garden, either digging, setting out, or weeding—there is no better way to preserve your health.” Hypnosis is the induction of a deeply relaxed state, with increased suggestibility and suspension of critical faculties. Patients in this state are given suggestions to encourage changes in behavior or relief of symptoms. The rationale for this method is that in the hypnotized state, the conscious mind presents fewer barriers, so it is more susceptible to successful psychotherapy. Additional methods used in alternative medicine include acupressure, Alexander technique, applied kinesiology, anthroposophic medicine, autogenic training, yoga, and meditation. SEE ALSO: Acupuncture; Chinese Medicine, Traditional. BIBLIOGRAPHY. P.M. Barnes, et al., Complementary and
Alternative Medicine Use among Adults: United States 2002 (National Center for Health Statistics, 2004); P. Prioreschi, “Alternative Medicine in Ancient and Medieval History,”
Medical Hypotheses (v.55/4, 2000); R. Rawlings, Healing Gardens (Willow Creek Press, 2001); D.V. Thomas, “Aromatherapy: Mythical, Magical, or Medicinal?” Holistic Nursing Practice (v.17/1, 2002); R.L. Train, The Effect of Horticultural Therapy in Maintaining the Life Satisfaction of Geriatrics (Kansas State University Press, 1974); A. Vickers and C. Zollman, “ABC of Complementary Medicine ‘Massage Therapies,’ ” British Medical Journal (v.319, 1999). Seyed Ali Mohammadi Rad Michigan Radiological Society Mohammad Gharipour Independent Scholar
Alzheimer’s Association Over the last 25 years, the number of Americans diagnosed with the progressive brain degeneration of Alzheimer’s disease has more than doubled, reaching 4.5 million in 2006. According to current estimates, by 2050, as the baby boomer generation ages, the number of Americans with Alzheimer’s will have climbed to between 11.3 and 16 million. The Alzheimer’s Association was established in 1980 to meet the needs of this growing population. Its national headquarters is located at 225 North Michigan Avenue in Chicago. Information on the Alzheimer’s Association and the community it serves is provided by toll-free telephone (800-272-3900) and the internet (www.alz.org). The mission of the Alzheimer’s Association is to improve the quality of life for those who suffer from the disease and to provide training and support for caretakers. In this capacity, one of the major functions of the Alzheimer’s Association is to serve as a clearinghouse for research on the disease. Ongoing research is regularly presented in the agency journal, Alzheimer’s and Dementia, which appears quarterly in July, October, January, and April. The Alzheimer’s Association network is composed of more than 100 chapters and 1,800 support groups located throughout the United States. In addition to offering support for patients and their caregivers, the association furnishes information and advice to medical professionals on how to improve the quality of healthcare for Alzheimer’s patients and lobbies legislators on issues associated with the health and well-being of their
target population. Fund-raising is an ongoing activity, and the Alzheimer’s Association sponsors the Memory Walk in September and October of each year in more than 600 communities throughout the United States. According to the Alzheimer’s Association, there are 10 warning signs for Alzheimer’s: memory loss, difficulty in performing everyday activities such as preparing a meal or using the telephone, having trouble with language, being disorientated to time and place, poor or decreased judgment, losing the ability for abstract thinking, constantly misplacing things, rapid changes in mood or behavior, personality shifts, and loss of initiative. Alzheimer’s may progress over a period ranging from three to 20 years. In its initial stages, Alzheimer’s may consist mainly of memory loss and difficulties in communicating. As the disease progresses, sufferers may experience delusions and hallucinations or even become violent. Most patients lose the ability to function without ongoing assistance. In its final stages, as brain cells further deteriorate, Alzheimer’s leads to death. The most common form of Alzheimer’s is dementia, which affects nearly half of all individuals over the age of 85 and a tenth of those over 65. The lobbying activities of the Alzheimer’s Association have been particularly important in recent years because funding for Alzheimer’s research and care was drastically cut by the George W. Bush administration. The budget for fiscal year 2007, for instance, proposed cutting funding by $7 million and slashed funds available to both the Alzheimer’s Association’s 24/7 Contact Center and the Safe Return program. The former provides matching grants to states to provide services to Alzheimer patients and their caregivers, and the latter helps to track Alzheimer’s patients who wander away from home. The president’s funding cuts were also designed to eliminate a joint Alzheimer’s research venture with the Centers for Disease Control and Prevention. See Also: Alzheimer’s Caregivers; Alzheimer’s Dis-
ease; Alzheimer’s Disease Education and Referral Center (ADEAR); Healthcare, U.S. and Canada.
Bibliography. Alzheimer’s Association, www.alz.org
(cited June 2007); L.E. Herbert, et al., “Alzheimer Disease in the U.S. Population: Prevalence Estimates Using the 2000 Census,” Archives of Neurology (August 2003); R. Kutzmman and K. Beck, Alzheimer Disease: The Changing View (Academic Press, 2000); Losing a Million Minds: Confront-
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ing the Tragedy of Alzheimer’s Disease and Other Dementias (U.S. Government Printing Office, 1987); H.C. Relyea and T.P. Carr, The Executive Branch: Creation and Organization (Novinka, 2003); L.A. Zipperer, ed., The Health Care Almanac: A Resource Guide to the Medical Field (American Medical Association, 1995). Elizabeth R. Purdy, Ph.D. Independent Scholar
Alzheimer’s Caregivers Alzheimer’s disease is a slowly developing neurodegenerative disease that results in progressive dependence of a person and typically imposes an intense demand on caregivers, so much so that caring for the caregivers is considered part of the treatment for Alzheimer’s disease. Alzheimer’s patients need support from the initial course of the disease, from care to avoiding accidents to advice for remembering routine activities such as bathing or eating. As the disease progresses, patients lose their capacity for instrumental activities of daily living (IADLs), such as taking a bus or preparing food, while retaining the ability for the basic activities of daily living (ADLs). In a more advanced stage, patients lose capacity for ADLs and need help performing simple and essential daily tasks. Bathing or eating a served meal may be challenging. In the final phase, patients are immobilized and unable to perform any ADL. Caregivers then have to assume every action needed for the patient’s survival. Even with the best care, patients further deteriorate and die due to the physical limitations imposed by the disease. Alzheimer’s caregivers are often family members, commonly a spouse, daughter, or son. In such situations, the deep feelings for the patient that act as a drive for caring can also become challenges during this time-consuming and physically and emotionally demanding task. Family members deal with the burden of caregiving while also experiencing the cognitive deterioration of those they love, including behavioral problems such as anger explosions, sleeping disorders, delusions, and more. Alzheimer’s patients may have part-time professional assistance or full care in a long-term facility.
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Whether a patient needs professional care is not necessarily dependent on demands of the disease itself. The main factor is the availability of family members willing to care and the number of people to share the task. This generally not only depends on the family members’ relationship with the patient, but also on how informed and prepared caregivers are. Important factors of successful caregiving include continual psychological follow-up of caregivers, taskspecific orientation for them to deal with each demand they will face, and the correct healthcare for the patient, because many health-related, preventable problems are common factors in the failure of family caregiving. When accepting the responsibility of caregiving, people should seek information on the disease, including potential complications and respective solutions. Apart from competent health professionals (Alzheimer’s disease will demand multidisciplinary healthcare), caregivers should try to locate the nearest peer support groups run by Alzheimer’s caregivers where they may share difficulties and experiences. SEE ALSO: Alzheimer’s Association; Alzheimer’s Dis-
ease; Alzheimer’s Disease Education and Referral Center (ADEAR); Caregivers; Dementia; Geriatrics. BIBLIOGRAPHY. P.M. Aupperle, “Navigating Patients and
Caregivers through the Course of Alzheimer’s Disease,” Journal of Clinical Psychiatry (v.67/Suppl. 3, 2006); R. Bullock, “The Needs of the Caregiver in the Long-Term Treatment of Alzheimer Disease,” Alzheimer Disease and Associated Disorders (v.18/Suppl. 1, 2004); Martin P.R. Kneebone II, “Coping and Caregivers of People with Dementia,” British Journal of Health Psychology (v.8, 2003); S. Sorensen, M. Pinquart, and P. Duberstein, “How Effective Are Interventions with Caregivers? An Updated MetaAnalysis,” Gerontologist (v.42/3, 2002). Thiago Monaco Independent Scholar
Alzheimer’s Disease Dementia is a brain disorder that seriously affects a person’s ability to carry out daily activities. Worldwide, there are an estimated 24 million people with
dementia. By 2040, it is projected that this figure will have increased to 81 million. The most frequent type of dementia is Alzheimer’s disease (AD), accounting for almost half of all patients with dementia. AD initially involves the parts of the brain that control thought, memory, and language. Correspondingly, advancing age is the primary risk factor for AD. In the United States, AD was the seventh leading cause of death in 2004, with 65,829 deaths. An estimated 4.5 million Americans currently have AD, and the numbers are rising. At over $100 billion per year, AD is the third most costly disease in the United States, after heart disease and cancer. The federal government estimates spending approximately $647 million for AD research in fiscal year 2005. Much of the concern about governmental social safety nets is founded on estimates of the costs of caring for baby boomers, assuming that they develop AD in the same proportions as earlier generations. The average lifetime cost of care for an individual with AD is $174,000. AD is a major public health challenge because the median age of the industrialized world’s population is increasing gradually. Among people aged 65, 2 to 3 percent show signs of the disease, while 25 to 50 percent of people aged 85 have symptoms of AD. An even greater number have some of the pathological hallmarks of the disease without the characteristic symptoms. Every five years after the age of 65, the probability of having the disease doubles. The share of AD patients over the age of 85 is the fastest-growing segment of the AD population in the United States. AD is named after Alois Alzheimer, a German doctor. In 1906, Dr. Alzheimer noticed changes in the brain tissue of a woman who had died of an unusual mental illness. He found abnormal clumps (now called amyloid plaques) and tangled bundles of fibers (now called neurofibrillary tangles), which today are considered hallmark signs of AD. Yet almost a century later, the ultimate cause of the disease is unknown. It is known, however, that genetic factors are important, and mutations in three different genes have been identified that account for a small number of cases. AD is definitely linked to the 1st, 14th, and 21st chromosomes, but other linkages are controversial and not, as yet, confirmed. While some genes predisposing to AD have been identified, such as ApoE4 on chromosome 19, sporadic AD also involves other risk and protective genes still awaiting confirmation.
Early-onset AD has been clearly shown to be genetic in origin. While mutations on chromosomes 9 and 19 have been linked with late-onset AD (the most common form), not everyone with the mutations develops the disease. The relationship between genetics and late-onset AD is not fully known. Some studies have implicated prior traumatic head injury, lower education level, and female gender as possible risk factors. Scientists are finding increasing evidence that some of the risk factors for heart disease and stroke, such as high blood pressure, high cholesterol, and low levels of the vitamin folate, may also increase the risk of AD. However, at the present time, no definitive causes have been identified. Evidence for physical, mental, and social activities as protective factors against AD is also increasing. Symptoms, Diagnosis, and Treatment The most striking early symptom of AD is loss of short-term memory (amnesia). At first, slips are only minor and can be confused with age-related memory change. Slowly, however, the forgetfulness steadily becomes more pronounced with illness progression, while preserving long-term memories. As the disorder progresses, those characteristics that help to make up the essential human qualities start to deteriorate. These changes include cognitive (intellectual) impair-
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ment and extend to the domains of language, skilled movements, and recognition. People in the middle stages of AD may forget how to do simple tasks such as brushing their teeth or combing their hair. They can no longer think clearly. They can fail to recognize familiar people and places. They begin to have problems speaking, understanding, reading, or writing. Later on, people with AD may become anxious or aggressive, or wander away from home. Eventually, patients need total care. The diagnosis is made primarily on the basis of history, clinical observation, and tests of memory and intellectual functioning over a series of weeks or months, with various physical tests (blood tests and neuroimaging) being performed to rule out alternative diagnoses. No medical tests are available to diagnose AD conclusively pre-mortem. Expert clinicians who specialize in memory disorders can now diagnose AD with an accuracy of 85 to 90 percent, but a definitive diagnosis of AD must await microscopic examination of brain tissue, generally at autopsy. Initial suspicion of dementia may be strengthened by performing the Mini Mental State Examination, after excluding clinical depression. Psychological testing generally focuses on memory, attention, abstract thinking, the ability to name objects, visuospatial abilities, and other cognitive functions. Results of psychological tests may not
An estimated 4.5 million Americans currently have Alzheimer’s disease, making it a major public health challenge. There is currently no cure, and medications offer relatively small symptomatic benefit for some patients but do not slow disease progression.
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readily distinguish AD from other types of dementia, but can be helpful in establishing the presence and severity of dementia. There is currently no cure for AD. Available medications offer relatively small symptomatic benefit for some patients but do not slow disease progression. Additionally, cognitive and behavioral interventions and rehabilitation strategies may be used as an adjunct to pharmacologic treatment, especially in the early to moderately advanced stages of the disease. The evidence relating certain behaviors, dietary intakes, environmental exposures, and diseases to the likelihood of developing AD varies in quality and in its acceptance by the medical community. Due to their observational design, studies examining disease risk factors are often at risk from confounding variables. Some proposed preventive measures are even based on studies conducted solely in animals. New Areas of Research The National Institute on Aging (NIA), part of the National Institutes of Health (NIH), is the lead federal agency for AD research. NIA-supported scientists are testing a number of drugs to see if they prevent AD, slow the disease, or help reduce symptoms. Scientists are finding that damage to parts of the brain involved in memory, such as the hippocampus, can sometimes be seen on brain scans before symptoms of the disease occur. An NIA public–private partnership, the AD Neuroimaging Initiative (ADNI), is a large study that will determine whether magnetic resonance imaging (MRI) and positron emission tomography (PET) scans, or other imaging or biological markers, can see early AD changes or measure disease progression. The NIA is sponsoring the AD Genetics Study to learn more about risk factor genes for late-onset AD. There is evidence that inflammation in the brain may contribute to AD damage. Some studies have suggested that drugs such as nonsteroidal anti-inflammatory drugs (NSAIDs) might help slow the progression of AD, but clinical trials thus far have not demonstrated a benefit from these drugs. Researchers are continuing to look for ways to test how other anti-inflammatory drugs might affect the development or progression of AD. Several years ago, a clinical trial showed that vitamin E slowed the progress of some consequences
of AD by about seven months. Additional studies are investigating whether antioxidants (vitamins E and C) can slow AD. Additionally, early studies suggested that extracts from the leaves of the ginkgo biloba tree may be of some help in treating AD symptoms. There is no evidence yet that ginkgo biloba will cure or prevent AD, but scientists are trying to find out in a clinical trial whether ginkgo biloba can delay cognitive decline or prevent dementia in older people. Some studies have suggested that estrogen used by women to treat the symptoms of menopause also protects the brain. Experts also wondered whether using estrogen could reduce the risk of AD or slow the disease. Clinical trials to test estrogen, however, have not shown that estrogen can slow the progression of already-diagnosed AD. And one study found that women over the age of 65 who use estrogen with a progestin are at greater risk of dementia, including AD, and that older women using only estrogen could also increase their chance of developing dementia. Scientists believe that more research is needed to find out if estrogen may play some role in AD. They would like to know whether starting estrogen therapy around the time of menopause, rather than at age 65 or older, will protect memory or prevent AD. SEE ALSO: Alzheimer’s Association; Alzheimer’s Caregiv-
ers; Alzheimer’s Disease Education and Referral Center (ADEAR); Dementia; Developmental Disabilities; Diagnostic Imaging; Huntington’s Disease; Movement Disorders; National Institute of Neurological Disorders and Stroke (NINDS); Parkinson’s Disease. BIBLIOGRAPHY. Alzheimer’s Association Fact Sheet: AN-
1792, news.bbc.co.uk (cited November 2006); J. Cervilla, et al., “Premorbid Cognitive Testing Predicts the Onset of Dementia and Alzheimer’s Disease Better than and Independently of APOE Genotype,” Psychiatry (v.75, 2002); M. Hashimoto, et al., “Role of Protein Aggregation in Mitochondrial Dysfunction and Neurodegeneration in Alzheimer’s and Parkinson’s Diseases,” Neuromolecular Medicine (v.4/1–2, 2003); M. Kerr and D. Small, “Cytoplasmic Domain of the Beta-Amyloid Protein Precursor of Alzheimer’s Disease: Function, Regulation of Proteolysis, and Implications for Drug Development,” Journal of Neuroscience Research (v.80/2, 2005); I. Lott and E. Head, “Alzheimer Disease and Down Syndrome: Factors in Pathogenesis,” Neurobiology of Aging (v.26/3, 2005); D.G.
Alzheimer’s Disease Education and Referral (ADEAR) Center
Munoz and H. Feldman, “Causes of Alzheimer’s Disease,” Canadian Medical Association Journal (v.162/1, 2000); S. Ohnishi and K. Takano, “Amyloid Fibrils from the Viewpoint of Protein Folding,” Cellular and Molecular Life Sciences (v.61/5, 2004); Dorene Rentz, “More Sensitive Test Norms Better Predict Who Might Develop Alzheimer’s Disease,” Neuropsychology (v.18/1, 2004); P. Tiraboschi, et al., “The Importance of Neuritic Plaques and Tangles to the Development and Evolution of AD,” Neurology (v.62/11, 2004); G. Wenk, “Neuropathologic Changes in Alzheimer’s Disease,” Journal of Clinical Psychiatry (v.64/ Suppl. 9, 2003). Barkha Gurbani UCLA School Of Medicine
Alzheimer’s Disease Education and Referral (ADEAR) Center Created by the U.S. Congress in 1990, the Alzheimer’s Disease Education and Referral (ADEAR) Center compiles, archives, and disseminates information concerning Alzheimer’s disease to healthcare professionals, patients, and family members affected by the disease, and to the general public. The organization is operated as a service of the National Institute on Aging (NIA), one of the federal government’s National Institutes of Health and part of the U.S. Department of Health and Human Services. The NIA conducts and supports research dealing with health issues related to the aging process and is the primary federal agency for Alzheimer’s disease research. The ADEAR Center is headquartered in Silver Springs, Maryland. Since its creation, the ADEAR Center has helped millions of Americans with information on Alzheimer’s disease and caregiving, updates on research, and referral services to community-based resources. It has disseminated material though conferences, exhibits and health fairs, and assisted with clinical trial recruiting. The center also offers online publications including a newsletter, Connections, that provides the latest medical and non-medical information related to Alzheimer’s disease.
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Due to the increase in the number of Americans suffering from the disease, ADEAR has significantly expanded its focus. Initially concentrating on communicating research advances to healthcare professionals, the organization established an ongoing outreach program designed to meet the needs of patients, their families, and particularly caregivers. ADEAR responds to questions and other requests from the general public, provides background information on clinical trials, and acts as a general clearinghouse for referrals and the distribution of information on healthy aging. In conjunction with the NIA, National Institute on Neurological Disorders and Stroke (NINDS), the National Institute on Mental Health (NIMH), the National Cancer Institute (NCI), National Institute on Nursing Research (NINR), and several private organizations, the ADEAR Center maintains a detailed database on clinical trials. This frequently updated resource includes information on the nature of individual trials, how individuals can get involved, various protocols and criteria, and a list and map of trial sites. All information provided by the Center comes under the scrutiny of NIA scientists and healthcare communicators who review the material for accuracy and integrity. If current trends continue, ADEAR should expand its service even further to keep up with demand. According to current research the number of Americans afflicted with Alzheimer’s disease will almost double over the next 25 years as the baby boom population ages and life expectancy among the elderly increases. See Also: Alzheimer’s Association; Alzheimer’s Caregiv-
ers; Alzheimer’s Disease.
BIBLIOGRAPHY. Alzheimer’s Association, www.alz.org
(cited June 2006); Alzheimer’s Disease Education and Referral Center, www.nia.nih.gov/Alzheimers (cited June 2006); Paul Dash and Nicole Villemarette-Pittman, Alzheimer’s Disease (Demos Medical Publishing, 2005); J. Madeline Nash, “The New Science of Alzheimer’s,” Time (July 17, 2000); National Institute on Aging, www. nia.nih .gov (cited June 2006); National Institutes of Health, www .nih.gov (cited June 2006). Ben Wynne, Ph.D. Gainesville State College
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Amblyopia
Amblyopia Amblyopia, or “lazy eye,” is an ocular disorder characterized by dominance of one eye’s input to the brain over the other. It occurs in about 3 percent of the population. If left untreated, amblyopia can cause permanent visual impairment in one eye, leading to lifelong consequences. However, early detection and treatment of amblyopia through the use of eye patches or eye drops can help strengthen the weaker eye and lessen or cure the disorder. Amblyopia is most commonly diagnosed as a twoline difference of visual acuity between both eyes. Several more comprehensive testing methods exist for determining the causes, classification, and extent of the amblyopia. Classification depends on the symptoms leading up to development. Under normal conditions, each eye’s retina picks up light-induced signals that travel through the optic nerve, combine, and reseparate into left and right visual hemispheres at the optic chiasm, and travel to the contralateral (opposite) sides of the visual cortex. Binocular interactions between the signals from both eyes result in integration of neural signals from both sides of the brain to form a single perceived image. Anisometropic amblyopia occurs when the unfocused eye’s image is inhibited to favor the image from the focused eye. Strabismus is characterized by dysfunction of ocular muscles and uncoordinated eye movement and fixation. Since both eyes send very different images to the brain, intraocular image conflict occurs. In strabismic amblyopia, the patient strongly favors movement and fixation using just one eye and neglects these functions in the other eye. Visual deprivation can be caused by a variety of conditions such as cataract, high refractive error (nearsightedness or farsightedness), corneal opacities, ptosis (drooping of the eyelid), or other disorders that result in understimulation of the retina. Such problems may lead to amblyopia and are especially detrimental during the earliest years of life, when the retina and visual pathways are rapidly developing and setting the course for all future visual function. This explains why the earlier amblyopia is diagnosed and treated, the better the hope for recovery. If a cataract or other ocular disorder is congenital or present from birth, immediate treatment is necessary to prevent permanent debilitation in the afflicted eye.
Studies have shown that early detection and treatment of amblyopia can result in surprising levels of improvement in the weak eye’s function. Previously, it was thought that the damage caused by amblyopia became permanent after age 7. New studies by the National Institutes of Health (NIH) have shown that the possibility for at least some improvement remains well into the teenage and adult years. Of course, since the visual system loses its neuroplasticity (ability to develop and adapt to new conditions) with age, the earlier this neuro-ophthalmological disorder is dealt with the better. With amblyopia prevalent in about 3 percent of the population, detection and treatment by 5 years of age reduced the prevalence to 2 percent, while even earlier measures taken by 3 years of age reduced the prevalence to 1 percent. The two major ways of treating amblyopia are use of eye patches (occlusion) and atropine drops (penalization). Measures taken to correct the specific cause of amblyopia, such as refractive correction or surgery, can also significantly improve binocularity. Occlusion involves covering up one eye with a patch and forcing use and improvement of the weaker eye. While occlusion is straightforward, the treatment has a low compliance rate, especially among young children, because eye patches are uncomfortable and can cause difficulty and embarrassment in situations such as school. Penalization involves using atropine drops to blur the image in the dominant eye, forcing use of the weak eye. Previously, it was believed that patients ought to be treated for long daily intervals. However, new NIH studies reveal that occlusion or penalization for as little as two hours each day can still be as beneficial as treatment for several hours. In light of low compliance rates, these results are good news for amblyopic children worldwide. Amblyopia is the leading cause of monocular vision loss in adults. Because they only have one functional eye, amblyopic patients are at greater risk for blindness. Negative consequences of untreated amblyopia can include reduced depth perception, reduced visual-motor skills, and psychosocial impacts such as low self-esteem, damaged interpersonal communication, and lower employability. Globally, amblyopia deserves attention because of its lifelong consequences on patients’ lives. SEE ALSO: Cataract; Eye Care; Eye Diseases (General);
Ophthalmologist; Ophthalmology.
American Academy of Family Physicians (AAFP)
BIBLIOGRAPHY. Lorraine Steefel, “Amblyopia,” in The Gale
Encyclopedia of Medicine, 3rd ed. (Thomson Gale, 2006); A. Webber and J. Wood, “Amblyopia: Prevalence, Natural History, Functional Effects and Treatment,” Clinical and Experimental Optometry (v.88, 2005); Kimberly G. Yen, “Amblyopia,” www.emedicine.com (cited October 2006). Nakul Shekhawat Vanderbilt University
American Academy of Addiction Psychiatry (AAAP) Founded in 1985 with approximately 1,000 members, the American Academy of Addiction Psychiatry (AAAP) seeks to educate the public and influence public policy with regard to addictive illness while increasing the overall effectiveness of psychiatric care in the United States related to addictions. The group’s mission includes promoting universal access to quality treatment for all those who need it, promoting excellence in the clinical practice of addictive psychiatry, disseminating new information on addictive illnesses, and encouraging research on the etiology, prevention, identification, and treatment of addictions. The AAAP supports an increased emphasis in medical education related to addiction and addiction therapy as well as increased government and private funding for research on alcohol and drug abuse. The group also provides continuing education to addiction professionals. The AAAP believes that substance abuse prevention and treatment should be a national priority and that substance abuse causes mental and physical illnesses that contribute to a myriad of social ills in the United States such as crime, homelessness, unemployment, family violence, and the breakup of families, and places added burdens on healthcare and law enforcement professionals. As a result, the group advocates the need for universal access in the United States to a mental healthcare package on par with those related to medical or surgical problems. This should include, but not be limited to, programs for screening, evaluation, detoxification, ongoing treatment, and followup that includes a psychiatric assessment. The AAAP also takes public stands on a variety of issues, some of which have proved controversial.
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While the group takes a strong stand against the legalization of drugs, it favors the medical use of marijuana under certain circumstances and supports the funding and development of programs that allow habitual intravenous drug users increased access to clean needles. The AAAP also endorses heavily monitored substance abuse treatment for nonviolent drug offenders in lieu of incarceration, and many AAAP members participate in the delivery of treatment to patients in the criminal justice system. A board of directors comprised of some of the nation’s leading healthcare professionals governs the AAAP, and the organization’s publication, The American Journal on Addictions, appears five times a year. Three times annually the group publishes a newsletter, AAAP News, with updates on research, current events that impact the addiction field, and general information about the activities of the AAAP and its members. The group has headquarters in Washington, D.C., and holds annual national conventions in major cities across the country. See Also: Alcoholism; Drug Abuse; Marijuana Abuse;
Heroin Abuse; National Institute on Alcohol Abuse and Alcoholism (NIAAA); National Institute on Drug Abuse. Bibliography. American Academy of Addiction Psy-
chiatry, aaap.org (cited June 2006); American Psychiatric Association, www.psych.org (cited June 2006); American Society of Addiction Medicine, www.asam.org (cited June 2006); Association for Medical Education and Research in Substance Abuse, www.amersa.org (cited June 2006); Norman S. Miller, ed., Principles and Practice of Addictions in Psychiatry (W.B. Saunders Co., 1997); John T. Pichot, et al., “Addiction Psychiatry: Training, Certification and Internet Resources,” www.unhooked.com (cited June 2006); Kevin A. Sevarino, Treatment of Substance Use Disorders (BrunnerRoutledge, 2002). Ben Wynne, Ph.D Gainesville State College
American Academy of Family Physicians (AAFP) Since its inception in 1947, the American Academy of Family Physicians (AAFP) has labored to advance
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American Academy of Nurse Practitioners (AANP)
the health of Americans by providing quality family healthcare in a cost-effective manner. This national association of family physicians operates according to seven major objectives: advocacy, which attempts to shape family care by lobbing legislators and encouraging positive interaction among the public, the business community, and healthcare professionals; practice enhancement, which promotes the development of healthcare practitioners who are able to balance their personal and professional lives; education of doctors, residents, and medical students in the art, science, evidence, and socioeconomics of family medicine; improving the health of the public by encouraging medical professionals to take the lead in promoting disease prevention and the management of chronic diseases; maintaining lines of communication among family healthcare providers and the broader community; recruiting an adequate workforce to meet the needs of all patients and communities; and outreach designed to promote the development of family medicine globally, nationally, and locally. Information on AAFP is provided through a toll-free number (800-274-2237) or through the academy’s Web site (www.aafp.org). On October 3, 1971, the American Academy of General Practice assumed its current identity, becoming the American Academy of Family Physicians in order to mirror shifts in perceptions of healthcare in America. The more than 94,000 members of AAFP reside in the 50 states, the nation’s capital, Puerto Rico, the Virgin Islands, and Guam. AAFP serves both the interests of the general public and physicians who practice family medicine. In order to ensure that family physicians continue to be aware of research and development within the field of family medicine, all active members of AAFP are required to complete at least 150 hours of continuing education every three years. There are a number of ways to meet this requirement, including attending classes, presenting papers at professional conferences, teaching at the postgraduate level, and residency training. AAFP, which is headquartered in Leawood, Kansas, is governed by a congress of delegates that is made up of two members of each of the 55 chapters and from various subgroups, such as those representing women and minorities. Meetings of this congress take place annually. The board of directors and various standing and special commissions and committees implement policies and oversee the day-to-day activities of AAFP.
In order to be licensed, family practitioners must take a certifying examination that is given annually. Recertification examinations are also given on this basis. AAFP’s clinical journal, American Family Physician, has a circulation of 156,000. Another journal, Family Practice Management, is geared toward practice management and socioeconomic issues. Current news relevant to the organization and the practice of family medicine is provided through AAFP News Now, which is available on the Web site, by e-mail, or through regular post. Current AAFP initiatives include disaster recovery, the provision of information on Medicare prescription drug coverage, an alliance with drug companies to offer patient prescription assistance to Americans whose incomes fall below a certain level, and efforts to achieve the ultimate goal of universal health coverage in the United States. The charitable arm of AAFP, the American Academy of Family Physicians Foundation, administers the Center for the History of Family Medicine, which serves as a clearinghouse for records on the practice of family medicine. See Also: American College of Physicians (ACP); Health-
care, U.S. and Canada.
Bibliography. American Association of Family Physi-
cians, www.aafp.org (cited December 2006); Robert B. Taylor, ed., Family Medicine: Principle and Practice (Springer, 2003); Earl Wysong, High Risks and High Stakes: Health Professionals, Politics, and Policy (Greenwood, 1992); Lorri A. Zipperer, ed., The Health Care Almanac: A Resource Guide to the Medical Field (American Medical Association, 1995). Elizabeth R. Purdy, Ph.D. Independent Scholar
American Academy of Nurse Practitioners (AANP) The American Academy of Nurse Practitioners (AANP) serves as an advocacy group for nurse practitioners in the United States. A nurse practitioner is an individual who has completed a specialized master’s degree and advanced practical training in addition to the requirements for the basic registered nurse (RN) program. In the course of obtaining this advanced de-
gree, nurses are trained in diagnostics and management techniques, preparing them to assist physicians in providing patients with quality healthcare. Patients may see nurse practitioners instead of physicians on routine visits. This practice frees up physicians to concentrate on providing health services to patients who require advanced knowledge and particular attention. Generally, nurse practitioners are authorized to order, perform, and interpret various medical tests, including lab work and X-rays; diagnose and treat chronic diseases and temporary infections and injuries; counsel patients; and educate patients on general health issues. In some states, they may also prescribe medications. AANP’s mission is to promote general health through advancing the role of the nurse practitioner in the medical profession. Awareness of the role of the nurse practitioner within the community is promoted through public service announcements that regularly appear on local television stations. For instance, the “Peaceful Moment” ad, offered in either English or Spanish, promotes the notion that patients are more likely to have peace of mind when they are cared for by friendly nurse practitioners than when services are offered through impersonal physicians. AANP also serves as the certification body for nurse practitioners. Candidates are required to take competency-based examinations on health promotion, disease prevention and diagnosis, and management of acute and chronic diseases. Nurse practitioners may choose among nine fields of specialization: acute care, adult health, family health, gerontology, neonatal, oncology, pediatric/child health, psychiatric/mental health, and women’s health. Subspecialty areas include allergy and immunology, cardiovascular, dermatology, emergency, endocrinology, gastroenterology, hematology and oncology, neurology, occupational health, orthopedics, pulmonology and respiratory health, and sports medicine. AANP also provides members with information on job opportunities, and scholarships are available to qualified applicants. In 1965, the University of Colorado became the first institution of higher learning to offer degrees to nurse practitioners. By 2006 the number of colleges and universities offering nurse practitioner degrees had reached 325, and around 6,000 new nurse practitioners were entering the field each year. Currently, there are 115,000 nurse practitioners in the United States. Ac-
American Academy of Ophthalmology
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cording to AANP data, 81 percent of its membership are currently employed as nurse practitioners, and 95 percent have earned graduate degrees. The membership is predominately female (97 percent) and white (89.2 percent). The national office of AANP is located in Austin, Texas, and further information is provided by telephone (512-442-4262) or on the AANP Web site (www.aanp.org). The Journal of the American Academy of Nurse Practitioners provides members with information on relevant research, news, and events. The advocacy role of AANP necessitates an active role in the political process, and the academy regularly lobbies legislators to protect the interests of nurse practitioners and on issues dealing with the delivery of quality healthcare in America. The Office of Health Policy is headquartered in Washington, D.C. The AANP Advocacy Center maintains an updated listing of all relevant bills and encourages members to contact relevant legislators to express support or opposition to particular bills. See also: American College of Nurse-Midwives (ACNM);
American Nurses Association (ANA); Association of Women’s Health, Obstetric, and Neonatal Nurses (AWHONN); National Institute of Nursing Research (NINR). Bibliography. American Academy of Nurse Practi-
tioners, www.aanp.org (cited December 2006); Anne B. Hamric, et al., Advanced Practice Nursing: An Integrative Approach (Saunders, 2005); Earl Wysong, High Risks and High Stakes: Health Professionals, Politics, and Policy (Greenwood, 1992); Lorri A. Zipperer, ed., The Health Care Almanac: A Resource Guide to the Medical Field (American Medical Association, 1995). Elizabeth R. Purdy, Ph.D. Independent Scholar
American Academy of Ophthalmology (AAO) The American Academy of Ophthalmology (AAO) was originally part of the American Academy of Ophthalmology and Otolaryngology (AAOO), which was founded in the 1890s to provide continuing education for eye, ear, nose, and throat doctors. In 1979,
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American Academy of Orthopedic Surgeons (AAOS)
the AAO was incorporated as an independent entity when the AAOO was divided into separate academies to serve physicians in the various specialties. The goals of the AAO are to advance the lifelong learning process and professional interests for ophthalmologists so that they can provide the general public with the best eye care possible. The group is headquartered in San Francisco and its membership of approximately 7,500 eye care professionals includes the vast majority of the United States’s practicing ophthalmologists. Education is a primary focus of the AAO’s mission and the organization offers a number of programs that meet the ever-evolving needs of America’s ophthalmologists. The academy also produces a wide variety of print and electronic materials for its members including reference books, audio and videotapes, CD-ROMs, self assessment programs, and an online educational delivery system. The AAO’s Governmental Affairs Division represents ophthalmologists and their patients before state and federal lawmakers and academy members meet regularly with government officials to consult on legislative issues that affect eye care delivery in the United States. With a variety of educational programs and public information campaigns, the group serves as the primary national outlet for preserving and protecting vision. Through a cooperative effort with other organizations, the AAO provides cutting-edge eye care information via the internet. The group produces a number of publications. The Ophthalmology Journal, the official journal of the AAO, provides peer-reviewed reports on the latest research in the field, and EyeNet Magazine is a monthly news magazine devoted to clinical, socioeconomic, and political trends that affect the practice of ophthalmology. Academy Express is a weekly news brief covering the latest academy news, current journal studies, specialty news, government advocacy, and other issues dealing with the ophthalmology industry. A board of directors that includes some of the nation’s leading eye care professionals governs the AAO. The board manages and directs the fiscal needs of the academy and allocates resources relative to the organization’s mission. In 1980 the Foundation of the American Academy of Ophthalmology was established to raise funds and maintain financial support for programs that advance ophthalmic education and develop ophthalmic educational products and servic-
es to improve eye care in both the United States and in developing countries. The foundation also supports the Museum of Vision, which preserves the history of the AAO and of ophthalmology in general while serving as a repository for valuable materials related to the field. Each year the museum acquires a wide array of items for its collection including historical artifacts, archival material, and rare books. More than 300,000 patrons visit the museum each year. See also: Ophthalmologist; Ophthalmology. Bibliography. American Academy of Ophthalmology,
www.aao.org (cited June 2006); Taylor Asbury, Paul Riordan-Eva, and John P. Whitcher, Vaughn and Asbury’s General Ophthalmology (McGraw Hill, 2003); The Foundation of the American Academy of Ophthalmology, www.eyecareamerica.org (cited June 2006); International Society of Refractive Surgery, www.isrs.org (cited June 2006). Ben Wynne, Ph.D. Gainesville State College
American Academy of Orthopedic Surgeons (AAOS) Since its founding in 1933 at Northwestern University, the American Academy of Orthopedic Surgeons (AAOS) has been the chief provider of musculoskeletal education around the globe. The academy offers advanced training through classes, conferences, publications, online material, and the Orthopaedic Learning Center. AAOS’s mission is to advance a high quality of musculoskeletal health by promoting the interest of patients and supporting orthopedic surgeons in their practices. The Academy, which began with a membership of less than 500, has grown to 24,000 members all over the world. The national headquarters of the American Academy of Orthopedic Surgeons is located at 6300 North River Road, Rosemont, Illinois, and AAPS may be reached by phone (847-823-7186) or via the internet (www.aaos.org). Orthopedic medicine is a special field of medicine that evolved from the need to treat children with deformities of the limbs and spine. The word orthopaedics is derived from two Greek words, ortho (straight) and
American Academy of Orthopedic Surgeons (AAOS)
pais (child). The symbol of the profession is a bent tree sporting a brace that has been attached to straighten its growth. Specifically, orthopedic surgeons treat disorders of bones, joints, ligaments, muscles, and tendons. To become an orthopedic surgeon, a physician must have completed five years of residency in addition to four years of medical school. The American Board of Orthopaedic Surgery serves as the certifying body of the profession, and all orthopedic surgeons are required to pass comprehensive oral and written exams. They must also face a stringent membership review that is a prerequisite for academy membership. Continuing education is provided to members through academy courses held at designated locations throughout the United States and through online courses. Research and concerns over specific issues are shared at the annual meeting at which 300 papers are presented and 180 instructional courses offered. Additional information is provided by scientific posters and technical exhibits on display at the conference. Three journals, The Journal of the American Association of Orthopedic Surgeons, JBJS-American, and JBJS-British, furnish members with articles on current research and issues. The Research and Scientific Affairs Department of AAOS is responsible for collecting, analyzing, and disseminating data generated by various groups. Research committees are charged with conducting and compiling research on designated subjects, including biological implants, biomedicine, infections, and occupational health and workers’ compensation. One of the ways in which AAOS promotes general good health is by informing the public about activities that may either cause or prevent injuries and by making the public aware of diseases that create musculoskeletal conditions. Press releases on relevant orthopedic issues are regularly distributed to the media. For example, AAOS issued a press release to inform males that despite popular belief, osteoporosis is not exclusive to aging females. Sports injuries frequently send patients to orthopedic surgeons, and when Arnold Schwarzenegger, the governor of California, broke his leg in December 2006, AAOP seized the opportunity to distribute the message that ski bindings might have made Swarzenegger vulnerable to injury because standing for long periods on skis creates potential hazards.
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Orthopedic surgeons treat disorders of the bones, joints, ligaments, muscles, and tendons.
The advocacy activities of AAOS are carried out by the American Association of Orthopaedic Surgeons. This agency, which is based at 317 Massachusetts Avenue, NE, in Washington, D.C., oversees government relations. AAOS serves its constituency by remaining cognizant of all relevant activities. In response, the advocacy staff lobbies legislators and monitors policy implementation of various government agencies. See also: Orthopedics; Orthopedist. Bibliography. American Association of Orthopedic Sur-
geons, www.aaos.org (cited December 2006); George L. Lucas, et al., A Primer of Biomechanics (Springer, 1999); Lonnie R. Mercier, Practical Orthopedics (Mosby, 1995); Earl Wysong, High Risks and High Stakes: Health Professionals, Politics, and Policy (Greenwood, 1992); Lorri A. Zipperer, ed., The Health Care Almanac: A Resource Guide to the Medical Field (American Medical Association, 1995). Elizabeth R. Purdy, Ph.D. Independent Scholar
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American Academy of Pediatrics (AAP)
American Academy of Pediatrics (AAP) The American Academy of Pediatrics (AAP) is an organization of 57,000 pediatricians from the United States, Canada, and Latin America who have acknowledged their commitment to promoting the health and well-being of infants, children, adolescents, and young adults. The membership includes specialists in various subfields, such as pediatric surgeons and pediatric oncologists. Through the National Agenda for Children, the AAP pursues the ultimate goal of affordable healthcare that serves the needs of its clientele, while also advancing educational and social needs. The national headquarters of the American Academy of Pediatrics is located at 141 Northwest Point Boulevard, Elk Grove Village, Illinois. Additional information on AAP is available by telephone (847-434-4000) or through the official Web site (www.aap.org). Governance is provided by a board of directors composed of 10 members elected to represent distinct regions. Day-to-day business is conducted by the executive committee, which is made up of a president, a national vice president (the president elect), and a committee vice president. The executive director is an ex officio member of the committee. Funding for the organization is provided through membership dues, revenue from AAP courses and activities, and charitable donations to the Friends of Children Fund and the Tomorrow’s Children Endowment. After the Civil War, the Industrial Revolution ushered in a period of rapid development in the United States in which even very young children were put to work in factories. The response to this practice was a rise in social consciousness that led to an awareness of children’s rights to be considered and celebrated on their own merits. Literature of the day spoke of treating the “whole child.” By the early 20th century, social movements promoting the welfare of children arose. In 1930 a group of 35 pediatricians met in Detroit, Michigan, and formed the American Academy of Pediatrics. These physicians were particularly concerned about promoting the value of preventive medicine, including regular checkups and immunization schedules. In order to deliver on its mission statement and keep members up to date on new research and issues of concern, AAP conducts regular continuing educa-
tion courses and hosts scientific meetings and seminars. Information on research and relevant issues is provided through Pediatrics, AAP’s scientific journal, Pediatrics in Review, an educational journal, and AAP News. Members also regularly produce books and pamphlets that inform the public and medical professionals about topics affecting infants, adolescents, and children. Throughout the year, AAP activities are carried out by committees devoted to pursuing research and development in areas affecting the target population, including injury and poison prevention, disabled children, sports medicine, nutrition, breastfeeding, and child health financing. The Department of Federal Affairs is a separate advocacy office located at 601 13th Street, NW, Washington, D.C. (202-347-8600). AAP also has advocacy staff in each state to promote the AAP agenda and to lobby legislators. One of the major initiatives at the federal level is the Campaign for Children’s Health, which pressures Congress to enact universal healthcare coverage for children. Campaigns at the state level include ASK (Asking Saves Kids), Bright Futures, Back to Sleep, Buckle Up America, Cover the Uninsured Week, and Healthy Foster Care America. Through regular press releases, AAP informs the public about issues concerning the welfare of infants, children, and adolescents. For instance, in December 2006, AAP expressed concern about the 40,000 advertisements a year that are believed to significantly contribute to obesity, poor nutrition, and cigarette and alcohol usage among America’s young people. See also: Adolescent Health; Child Safety; Infant and
Toddler Health; Pediatrics.
Bibliography. American Academy of Pediatrics, www
.aap.org (cited December 2006); R.E. Behrman, et al., Nelson Textbook of Pediatrics (Saunders, 2000); Julia A. McMillan, ed., Oski’s Pediatrics: Principles and Practice (Lippincott Williams, and Wilkins, 1999); Abraham M. Rudolph, et al., Rudolph’s Pediatrics (McGraw-Hill, 2001); Earl Wysong, High Risks and High Stakes: Health Professionals, Politics, and Policy (Greenwood, 1992); Lorri A. Zipperer, ed., The Health Care Almanac: A Resource Guide to the Medical Field (American Medical Association, 1995). Elizabeth R. Purdy, Ph.D. Independent Scholar
American Association for Cancer Research (AACR)
American Association for Cancer Research (AACR) Researchers have identified more than 200 kinds of cancers that attack the human body. In addition to leukemia, the most common forms of cancer occur in the brain, breasts, colon, head and neck, lungs, ovaries, and prostate. Each year, cancer claims the lives of approximately 500,000 Americans and affects the health, lives, and family dynamics of millions of cancer survivors. The American Association for Cancer Research (AACR) is dedicated to identifying the causes of cancer, treating those with cancer, and preventing cancer among those who have been fortunate enough to escape the disease. The organization began in 1907 when 11 physicians founded AACR with the intention of promoting research into cancer and disseminating available information on the topic to both the medical community and the public. The national headquarters is located at 615 Chestnut Street in Philadelphia, Pennsylvania. Information on cancer and on AACR’s activities is available by telephone (215-440-9300) or on the internet (www.aacr.org). The AACR Web site also provides upto-date information on cancer centers, support groups, new treatments, and current clinical trials. Today, the AACR has more than 24,000 members who have joined together to provide information about research and development into the causes, diagnosis, treatment, and prevention of cancer. AACR members are based in the United States and in 70 other countries. Members include researchers, medical professionals, cancer survivors, and advocates. Five peer-reviewed journals, Cancer Research, Clinical Cancer Research, Molecular Cancer Therapeutics, Molecular Cancer Research, and Cancer Epidemiology, Biomarkers, and Prevention, serve as vehicles to inform AACR members and the medical profession about innovative research and cutting-edge technology in cancer prevention and treatment. AACR also sponsors regular conferences, seminars, and workshops; the annual meeting is attended by around 17,000 researchers and physicians. Presented in less scientific language than the five peer-reviewed journals, CR, which identifies itself as “a magazine about people and progress in cancer,” targets cancer survivors, patient advocates, and families
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and physicians of cancer patients. The mission of CR is to promote collaboration and communication of cancer survivors and their support groups with the community of researchers, physicians, and advocates while promoting the overall purpose of preventing and curing cancer. The magazine carries practical advice about a variety of related topics, such as starting advocacy and support groups. As the charitable arm of the AACR, the AACR Foundation for the Prevention and Cure of Cancer is geared toward providing financial support for highpriority research, education, and communication of cancer-related topics. Funding is awarded to promote innovation in cancer research, expand knowledge and training of cancer researchers, and enhance public understanding of cancer and cancer research. Through the AACR Centennial Research Grant Fund, AACR matches every dollar contributed with $2 from its own funds. Donations may be earmarked for the Centennial Research Grant Fund for Early-Career Scientists, and AACR matches contributions to this fund on a four-to-one basis. At the international level, AACR is committed to preventing and curing cancer throughout the world. Specific goals are facilitating the exchange of research knowledge, encouraging global collaborations, promoting research and training across national borders, promoting global dialogues on issues related to cancer, extending global access to AACR programs and resources, incorporating international research into AACR’s agenda, building and maintaining relationships with other cancer research organizations, and enhancing public awareness of cancer research on a global basis. Advocacy for cancer prevention, research, and treatment is a major focus of AACR activities, and the AACR Science Policy and Legislative Affairs Committee frequently appears before Congress, the National Cancer Advisory Board, and other government agencies to testify about issues related to cancer research. The committee also lobbies Congress to seek additional funding for biomedical research. Other members perform similar functions at the state level. Regular e-mail Action Alerts inform legislators and members about import issues and developments. Disseminating information on hot topics is an important element of serving the public. For instance, AACR has been heavily involved in making the public aware that many cervical cancers are caused by human
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American Association for Health Education (AAHE)
papillomaviruses (HPV). In summer 2006, the Food and Drug Administration (FDA) approved the first known vaccine to protect women against high-risk types of HPV. Subsequently, the Advisory Committee on Immunization Practices (ACIP) recommended that all females between the ages of nine and 26 receive the vaccinations, and the U.S. government began sponsoring public service ads to inform the public about the vaccine. AACR warns women that they may be infected with HPV without showing symptoms and cautions that women still need regular Pap smears, because the vaccine may not protect against all forms of HPV. AACR also alerts women to the fact that cigarette smoking in women with high concentrations of HPV may increase cancer risks by as much as 27 percent. Periodic press releases inform the media and the public about ongoing research and encouraging developments. A December 11, 2006, report, for instance, offered the information that smokers may cut the risk of cancer through exercise but emphasized that the most effective measure in cancer avoidance is still giving up smoking entirely. A November 15, 2006, press release touted the possibility that a new virus to stimulate immune systems in colorectal cancer patients holds promise. Other reports informed the public that diet, exercise, aspirin consumption, and childbirth all play a role in decreasing risks of certain cancers. See also: American Cancer Society (ACS); Association
for International Cancer Research (AICR); Cancer (General); National Cancer Institute (NCI). Bibliography. American Association for Cancer Re-
search, www.aacr.org (cited December 2006); Roger Hardman and Leonard Lichtenfeld, eds., American Cancer Society: Fulfilling the Potential of Cancer Prevention and Early Detection (National Academies Press, 2004); Robert A. Weinberg, Racing to the Beginning of the Road: The Search for the Original Cancer (Harmony Books, 1996); Earl Wysong, High Risks and High Stakes: Health Professionals, Politics, and Policy (Greenwood, 1992); Lorri A. Zipperer, ed., The Health Care Almanac: A Resource Guide to the Medical Field (American Medical Association, 1995). Elizabeth R. Purdy, Ph.D. Independent Scholar
American Association for Health Education (AAHE) Established in 1937 as the Health Division of the American Alliance for Health, Physical Education, Recreation, and Dance (AAHPERD), the American Association for Health Education (AAHE) has been an independent organization since 1973. The organization represents more than 7,500 health educators and specialists and is the oldest and largest group of its kind in the United States. Although an independent group, the AAHE remains one of six national associations that together are part of the AAHPERD. The mission of the AAHE is to advance the cause of health education through a comprehensive approach that encourages, supports, and assists health professionals in a variety of settings including community organizations, public agencies, businesses, schools at all levels, and institutions of higher learning. To accomplish its goals the group promotes the development of national research priorities and facilitates the practical use of research among a constantly expanding network of health education professionals. The AAHE also takes a lead role in developing policies for healthcare programs and interfacing with other like-minded groups, as well as legislators, to promote the latest research and development opportunities. With regard to continuing education, the National Commission for Health Education Credentialing (NCHEC) recognizes the AAHE as a multiple event provider of health education contact hours. Among its many other ongoing functions, the AAHE collects, analyzes, and disseminates health data in an effort to understand and monitor the health needs of individuals and their communities. This includes the identification and assessment of potential public health dangers and outlining strategies to prevent or minimize their impact on the population as a whole. Paying particular attention to the needs of the young, the AAHE works with health educators and parents to provide the healthiest environment available for children. This includes programs to broaden day care option, the development of detailed preschool and early childhood health education programs, and the implementation of plans designed to provide economic, physical, and moral support for communities that include many families with younger children.
American Association of Orthodontists (AAO)
A board of directors that includes some of America’s leading health education professionals governs the AAHE. The organization publishes a refereed bimonthly magazine, the American Journal of Health Education, serves as the profession’s voice and source of news and information, keeping educators up to date on issues, trends, teaching methods and curriculum developments in health. In addition, the AAHE publishes the International Electronic Journal of Health Education, a peer-reviewed electronic journal; HEXtra, a quarterly newsletter; HIV Prevention and CSHE Project Brief, a triannual publication related to HIV education and prevention; and scores of pamphlets and booklets on specific health topics. The AAHE also sponsors an annual convention in association with the AAHPERD. See also: American Public Health Association (APHA);
National Association of Health Data Organizations (NAHDO); National Center for Public Health Informatics (NCPHI). Bibliography. American Alliance for Health, Physical
Education, Recreation and Dance, www.aahperd.org (cited June 2006); American Association for Health Education, www .aahperd.org/aahe (cited June 2006); M.N. Freed, R.K. Hess, and J.M. Ryan, The Educator’s Desk Reference: A Sourcebook of Educational Information and Research (Praeger, 2002); Jerrold S. Greenberg, The Code of Ethics for the Health Education Professionals: A Case Study Book (Jones and Bartlett, 2001); John C. Smart, ed., Higher Education: Handbook of Theory and Research (Agathon Press, 1999). Ben Wynne, Ph.D Gainesville State College
American Association of Orthodontists (AAO) The American Association of Orthodontists (AAO) was founded in 1901 in St. Louis, Missouri. Today, the organization includes more than 15,000 members representing 95 percent of orthodontists who have graduated from accredited orthodontic programs. The organization functions as a professional association of educationally qualified orthodontic specialists
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dedicated to ethically advancing the art and science of orthodontics and dentofacial orthopedics, improving the health of the public by promoting quality orthodontic care, and supporting the successful practice of orthodontics in general. The association’s founder, Dr. Edward Hartley Angle, was an early proponent of orthodontics as a specialized field of study. A true pioneer, he spent most of his adult life promoting the profession. Angle was born on a farm in Pennsylvania in 1855 and at the age of 22 graduated from the Pennsylvania College of Dentistry. In 1892, he gave up general dental practice and became the first person to specialize exclusively in the teaching and practice of orthodontia. In 1900, he opened his first private school for the teaching of orthodontia in St. Louis. Not long afterward, 11 of Dr. Angle’s initial graduates organized the world’s first orthodontic society, the Society of Orthodontists. They later added the word “American” to the name and the organization became known as the American Society of Orthodontists. This represented the genesis of the present association. In 1907, Dr. Angle moved the school to New York and the next year to New London, Connecticut, where it held regular sessions until 1911. Dr. Angle eventually gave up the practice of orthodontia and devoted himself to the study, teaching, and the development of better and more refined orthodontic appliances. He died in 1930 in Pasadena, California. The American Journal of Orthodontics and Dentofacial Orthopedics remains the nation’s leading orthodontic resource. It is the official publication of the AAO and its constituent societies, the American Board of Orthodontics and the College of Diplomates of the American Board of Orthodontics. Published monthly, the journal gives its subscribers access to original peer-reviewed articles that examine all phases of orthodontic treatment. The journal is fully illustrated with tables, photos, and statistical data and includes information on successful diagnostic procedures, imaging techniques, bracket and archwire materials, extraction and impaction concerns, orthognathic surgery, temporomandibular joint (TMJ) disorders, removable appliances, and adult therapy. The association holds a meeting every year, usually in the spring, along with various regional conferences and workshops held throughout the year at different locations. Continuing education credits are offered at these meetings and also through an online
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American Cancer Society (ACS)
program. The AAO Foundation is the charitable arm of the AAO that provides support to orthodontic education programs and orthodontic research around the country. See also: American Dental Association (ADA); Dental
Health.
Bibliography. American Association of Orthodontists,
www.braces.org (cited October 2006); American Association of Orthodontists Foundation, www.aaofoundation.net (cited October 2006); American Board of Orthodontics, www.americanboardortho.com (cited October 2006); Edward H. Angle Society of Orthodontists, www.angl.allenpress.com (cited October 2006); Wilbur Morse Shankland, The American Association of Orthodontists: The Biography of a Specialty Organization (American Association of Orthodontists, 1971). Ben Wynne, Ph.D Gainesville State College
American Cancer Society (ACS) The American Cancer Society (ACS) is one of the most visible health-related organizations in the United States. It is also the largest voluntary health organization in the world. ACS was founded in 1913 as the American Society for Control of Cancer. The community-based program is wholly dedicated to eliminating cancer in the United States. As a means of accomplishing this, ACS endeavors to prevent cancer, save lives, and ease the lives of cancer sufferers through cancer research, education, advocacy, and service. At the international level, ACS focuses on collaboration and information sharing on a global basis. The national headquarters for ACS is located in Atlanta, Georgia. Information on the agency is available by telephone (800-ACS-2345) or on the ACS Web site (www.cancer.org). There are more than 3,400 local chapters in the United States, and area chapters may be located by entering individual Zip codes into a locater on the ACS Web site. Some 90 percent of ACS funding is provided by private donations, and corporate donors such as IBM, MetLife, Neutrogena, Wal-Mart/Sam’s Club,
Walgreen’s, Weight Watchers, and Wells Fargo are integral to the work accomplished by ACS. Volunteers are the heart of ACS, and more than three million volunteers from the medical profession and lay community conduct research, educate the public, lobby legislators at the national, state, and local levels, and provide support for those affected by cancer. Support for cancer patients and their families includes a range of activities that vary from counseling to locating housing when treatment centers are far from home. To protect the public interest, ACS implements checks and balances throughout its system. Governance is provided by the National Assembly and the National Board of Directors. The National Assembly is composed of six delegates from each of 14 divisions, the 43-member Board of Directors, up to 12 past ACS officer delegates, and a number of honorary lifetime delegates. The Assembly is responsible for electing the National Board of Directors, approving bylaws and division chapters and charter requirements, selecting the Nominating Committee, and approving the Division of Funds Policy. The National Board of Directors is made up of 11 officers, 24 directors, eight directors-at-large, and an exofficio Trustee Liaison. All director positions are split evenly among the medical and lay communities. Research into cancer prevention and treatment is a significant element in achieving the ultimate goal of eradicating cancer. From an initial investment of $1 million raised by Mary Lasker in 1946, ACS’s total research contribution has grown to around $3 billion. In the fiscal year ending 2004, 15 percent of the ACS budget was allotted to research ($120 million), 21 percent to prevention ($170 million), 19 percent to patient support ($160 million), and 16 percent to detection and treatment ($131 million). Of the remaining 29 percent of the budget, seven percent ($64 million) was allocated to general management and 22 percent ($178 million) to fund-raising. From the first cancer prevention study launched in 1959, ACS has played a role in more than 100 cancer research studies. Forty Nobel Prize winners received ACS funding early in their careers. Partnership with other organizations and government agencies that fight cancer is essential to the effectiveness of the ACS. The ACS research program is divided among outside grants, intramural epidemiology and surveillance research, and the ACS behavioral research
American College Health Association (ACHA)
center. Education is another key factor in fighting cancer, and public education and cancer prevention receive a good deal of ACS attention. According to the ACS, cancer is characterized by uncontrolled growth and the spread of abnormal cells. ACS data reveal that American women have a lifetime risk of one in three of developing cancer, and men have less than a one in two lifetime risk. Cancer risks may be increased by lifestyle, genetics, or exposure to toxic materials. External factors identified by ACS as possible causes of cancer include tobacco, chemicals, radiation, and infectious organisms. Internal factors that may increase the risk of cancer are inherited mutations, hormones, immune conditions, and mutations that occur from metabolism. ACS estimates that some 170,000 deaths occurred in the United States in 2006 because of tobacco use, and states that all of those could have been prevented. Other cancers related to nutrition, physical inactivity, and obesity are also considered preventable, as are skin cancers caused by unprotected exposure to the sun’s rays. Cancers may grow without warning for up to 10 years. Once diagnosed, cancer is treated through surgery, radiation, chemotherapy, hormones, and immunotherapy. As with all health organizations, advocacy is an essential ingredient in protecting the interests of the target group. The American Cancer Society regularly pressures Congress and the executive branch of government to increase funding for cancer research, broaden the network of cancer prevention, early detection, and treatment, smooth the navigation path of healthcare systems, and improve the quality of life for cancer patients and survivors and their families. The ACS Cancer Action Network (www.acscan.org) operates as a sister advocacy organization focused on voter campaigns and promoting laws and policies that further the goal of eliminating cancer and improving cancer treatments. Important milestones in ACS history include the campaign to encourage women to consider the Pap test as an essential part of healthcare; since its inception in 1960, this campaign has helped to cut the death rate from uterine cervix cancer by more than 70 percent. That same year, ACS led the campaign to raise public awareness about the connection between lung cancer and tobacco use and began pressuring Congress to ban tobacco advertising. In 1971, ACS launched the first
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Great American Smokeout, lobbying Congress for passage of the landmark National Cancer Act, which significantly increased federal cancer funding. The I Can Cope program was initiated in 1979 to provide professional support for cancer patients and their families and friends. The following year, ACS published early detection guidelines for breast cancer. Cancer camps for children were first opened in 1981. ACS was instrumental in the passage of the Americans with Disabilities Act of 1990, which prohibited discrimination against cancer patients as well as against those with other disabilities. Likewise, the presence of ACS was felt in the passage of the Family and Medical Leave Act of 1993, which protected jobs of individuals who took leave to care for family members with cancer. See also: American Association for Cancer Research
(AACR); Cancer (General); Coping with Cancer; National Cancer Institute (NCI); National Coalition for Cancer Survivorship (NCSS). Bibliography. American Cancer Society (ACS), www
.cancer.org (cited December 2006); ACS, “Cancer Facts and Figures 2006,” www.cancer.org (cited December 2006); Roger Hardman and Leonard Lichtenfeld, eds., American Cancer Society: Fulfilling the Potential of Cancer Prevention and Early Detection (National Academies Press, 2004); Walter S. Ross, Crusade: The Official History of the American Cancer Association (Arbor House, 1987); Robert A. Weinberg, Racing to the Beginning of the Road: The Search for the Original Cancer (Harmony Books, 1996); Earl Wysong, High Risks and High Stakes: Health Professionals, Politics, and Policy (Greenwood, 1992); Lorri A. Zipperer, ed., The Health Care Almanac: A Resource Guide to the Medical Field (American Medical Association, 1995). Elizabeth R. Purdy, Ph.D. Independent Scholar
American College Health Association (ACHA) Originally called the American Student Health Association (ASHA), the American College Health Association (ACHA) was formed in 1920 and today serves as
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American College of Epidemiology (ACE)
the leading organization in the field of college health, providing services, information, and advocacy that helps its members improve the health of their campus communities. The association has grown from less than 24 original institutions of higher education to almost 1,000. The ACHA’s institutional members represent two- and four-year public and private colleges and universities across the nation. Student health services at these institutions can range from singlenurse offices to fully staffed healthcare facilities. The ACHA also serves more than 2,400 college healthcare professionals including administrators, support staff, physicians, nurses, nursing directors, mental health providers, nutritionists, pharmacists, and students to better address individual needs. The ACHA sponsors a wide range of programs that address specific healthcare issues of postsecondary students in the United States, including alcohol and drug abuse, tobacco use, sexual health, nutrition, violence, vaccinations, and mental health. The Association’s programs and services address gender-specific health issues and those affecting minority populations. An 18-member board of directors governs the ACHA and the association’s national office is located near Baltimore, Maryland. In 1995, the American College Health Foundation (ACHF) was organized to provide long-term financial support for the ACHA through the development of endowments. The foundation is governed by a board of directors independent from the governing board of the ACHA, and supports projects and activities that would not otherwise be funded by conventional revenue sources. Independently and in cooperation with other organizations the association lobbies state and national legislators and is a leading voice in debates on current healthcare issues. The ACHA produces a number of publications related to its mission. Published bimonthly, the Journal of American College Health is the association’s primary professional journal. It disseminates information on the latest developments and research in the field including clinical and preventive medicine, environmental health and safety, nursing assessment, intervention, pharmaceuticals, and sports medicine. The Journal publishes articles on student behavior and healthcare policies and includes a section designed to stimulate discussion of controversial issues. The organization also publishes a quarterly newsletter and
a variety of brochures dedicated to important healthcare issues and designed for the target audience of college students. One of the ACHA’s primary functions is to provide continuing education for college and university healthcare professionals. Every year the association sponsors regional and national workshops, seminars, and internet-based training as well as an annual national convention that allows healthcare professionals from around the country the opportunity to exchange ideas and take advantage of other continuing education activities. See also: Adolescent Development; Adolescent Health. Bibliography. American College Health Association,
Annual Report (FY 2005); American College Health Association, www.acha.org (cited June 2006); Ruth E. Boynton, “The First Fifty Years: A History of the American College Health Association,” Journal of the American College Health Association (v. 19, 1971); William A. Christmas, “The History of Sections in the American College Health Association,” Journal of American College Health” (v. 41, 1992). Ben Wynne, Ph.D. Gainesville State College
American College of Epidemiology (ACE) Established in 1979, the American College of Epidemiology (ACE) is the nation’s primary professional organization dedicated to continuing education and advocacy for epidemiologists. As part of an ongoing effort to promote advances in science and public healthcare, ACE sponsors scientific meetings, publications, workshops, educational conferences, and a number of special programs related to epidemiology. Specifically, ACE advocates policies and actions that enhance the science, study, and practice of epidemiology; promote the professional development of epidemiologists; and recognize excellence in epidemiology and outstanding leaders in the field. Since its founding, ACE has experienced steady growth; the group has developed and maintains a large membership base representing all aspects of epidemiology.
American College of Nurse-Midwives (ACNM)
One of the organization’s most important functions is the establishment of ethical guidelines for the field of epidemiology. This includes identifying and defining core values, duties, and virtues in epidemiology, such as a dedication to the concept of free inquiry and the pursuit of knowledge, and the ongoing effort to improve public health through the practical application of scientific discovery. In addition, the ACE promotes mentoring programs for graduate students in the field of epidemiology and serves as an advocacy group for issues related to patient confidentiality. The group takes an active role in calling attention to major disparities in healthcare and health risks between the U.S. population in general and minority populations. A 19-member board of directors that includes some of America’s leading healthcare professionals governs ACE, which has its headquarters in Raleigh, North Carolina. The organization publishes Annals of Epidemiology, a monthly peer-reviewed international journal that deals with issues affecting the causes and distribution of human illnesses on a global basis, and a quarterly newsletter with information on the organization and its membership. Each year, in association with a number of other organizations, the ACE sponsors an annual meeting called the Congress of Epidemiology, where professionals in the field exchange the latest information. Groups that are related to, or work closely with ACE include the International Epidemiological Association, Council for State and Territorial Epidemiologists, International Society for Environmental Epidemiology, and Society for Healthcare Epidemiology of America. See Also: International Clinical Epidemiology Network
(INCLEN); International Epidemiological Association (IEA); International Society for Environmental Epidemiology (ISEE); Society for Healthcare Epidemiology of America (SHEA). Bibliography. American Academy of Epidemiology,
www.acepidemiology2.org (cited June 2006); Congress of Epidemiology 2006, “Program Information,” www.epicongress2006.org (cited June 2006); Anders Ahlbom, Introduction to Modern Epidemiology (Epidemiology Resources, 1990); John M. Last, A Dictionary of Epidemiology (Oxford University Press, 1995); David E. Lilienfeld and Paul D. Stolley, Foundations of Epidemiology (Oxford University
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Press, 1994); Kenneth J. Rothman, Epidemiology : An Introduction (Oxford University Press, 2002). Ben Wynne, Ph.D. Gainesville State College
American College of Nurse-Midwives (ACNM) In 17th- and 18th-century America, midwives were depended on not only to deliver babies, but also to advise women about pregnancies, birth control, abortion, and infant care. Few midwives of this period were formally educated. Instead, they were trained in medicinal folklore and possessed a wide knowledge of the use of herbs. Midwives tended to be workingclass women, and many were immigrants or slaves. As knowledge of medicine grew, the licensing of physicians forced midwives out of birthing rooms, except in isolated communities. However, increasing mortality during the 1920s (124 deaths per 1,000 live births) and the expansion of the public health system led to the recognition that nurse-midwives could fill a vital role in promoting good prenatal and postnatal care. In response to this need for improved infant and maternal health, Mary Breckinridge established the Frontier Nursing Service in the Appalachian Mountains of Kentucky and imported British nurse-midwives to join other public health nurses. The first nurse-midwifery school soon followed, and in 1939 the Frontier Graduate School of Midwifery, which became the Frontier School of Midwifery and Family Nursing, opened its doors. The first professional organization for nurse-midwives was founded in 1955 as the American College of Nurse-Midwifery of New Mexico. After merging with the American Association of Nurse-Midwives of Kentucky in 1969, the organization became the American College of Nurse-Midwives (ACNM), which continues to serve as the professional organization for all certified American nurse-midwives. The national headquarters of ACNM is located at 8403 Colesville Road, Suite 1550, Silver Spring, Maryland. Information on the organization is available by telephone (240-485-1800) or via the internet (www.midwife.org).
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American College of Obstetricians and Gynecologists (ACOG)
The women’s movement of the 1960s and renewed interest in women’s health signaled a resurgence in the number of certified nurse-midwives (CNMs). They increased from 1,723 in 1963 to 2,550 by 1982. In 1995 there were 2,000 practicing CNMs in the United States. Many of them worked in the birthing centers that sprang up around the country and in hospitals, where they worked closely with physicians to promote healthy pregnancies and birthing. Between 1990 and 2003, the number of births attended by midwives climbed from 3.9 percent to 8 percent. In Georgia, New Hampshire, New Mexico, Oregon, Vermont, and Alaska, at least 16 percent of all births are attended by midwives. By 2006, more than 7,000 nurse-midwives from 50 states were certified by the American College of Nurse-Midwives. Together, they attended some 277,811 births. The focus of the American College of Nurse-Midwives is on setting high professional standards for midwives that will allow them to fill their assigned roles in the pregnancy and birthing processes. In addition to certification, ACNM offers its members opportunities for education and practical training, recognition, insurance, and support. Ongoing research is an important element in fulfilling the purpose of the organization, and ACNM stresses the necessity for interprofessional and interorganizational communication and relationship-building. Up-to-date research and information is available through the Journal of Midwifery and Health. Another journal, Quickening, is available only to members. The American College of Nurse Midwives Foundation, Inc., which serves as the charitable arm of ACNM, was established to promote the health of newborns, women, and families by sponsoring studies, surveys, and research; publishing and disseminating relevant material; granting scholarships to eligible candidates for nurse-midwives programs and fellowships to practicing nurse-midwife practitioners; and sponsoring educational and scientific meetings. See also: Association of Women’s Health, Obstetric, and
Neonatal Nurses (AWHONN); Midwife; Obstetrics.
Bibliography. American College of Nurse Midwives
www.midwife.org (cited December 2006); Clare Hanson, A Cultural History of Pregnancy: Pregnancy, Medicine, and Culture, 1752–2000 (Palgrave, 2004); Judith Pence Rooks,
Midwifery and Childbirth in America (Temple University Press, 1997); Helen M. Sterk, et al., Who’s Having This Baby? Perspectives on Birthing (Michigan State University Press, 2002); Earl Wysong, High Risks and High Stakes: Health Professionals, Politics, and Policy (Greenwood, 1992); Lorri A. Zipperer, ed., The Health Care Almanac: A Resource Guide to the Medical Field (American Medical Association, 1995). Elizabeth R. Purdy, Ph.D. Independent Scholar
American College of Obstetricians and Gynecologists (ACOG) The American College of Obstetricians and Gynecologists (ACOG) was founded in 1951 in Chicago, Illinois, and is currently based in Washington, D.C. ACOG has almost 50,000 members, all of whom must be physicians who are board certified in obstetrics and gynecology; approximately 95 percent of all obstetrician-gynecologists in the United States are members of the organization. Members are both generalists and subspecialists, including maternal-fetal medicine specialists, gynecologic oncologists, reproductive endocrinologists, and urogynecologists. Women constitute 38 percent of ACOG’s total membership. The stated objectives of ACOG involve fostering and stimulating improvements in all aspects of healthcare for women. The group promotes the highest possible standards for education and the highest ethical standards of practice in its relationship to the public welfare. ACOG also sponsors publications and encourages contributions to medical and scientific literature. Obstetrics & Gynecology, popularly known as “the green journal,” is the official peer-reviewed journal of the ACOG. Published monthly, the journal includes original articles and research studies on general scientific advances, cutting-edge medical and surgical techniques, obstetric management, and clinical evaluations of drugs. Obstetrics & Gynecology is recognized as one of the most reliable and respected sources of information on current developments in women’s healthcare. Among ACOG’s other regular
American College of Occupational and Environmental Medicine (ACOEM)
publications are ACOG Clinical Review, a newsletter that offers synopses of the latest developments in obstetrics, gynecology, oncology, and infertility, and ACOG Today, a monthly newsletter designed to keep members up to date on the latest trends in the field. The college distributes a variety of educational literature including Planning Your Pregnancy and Birth, Encyclopedia of Women’s Health, Managing Menopause Magazine, and more than 200 different pamphlets on a wide range of subjects relating to women’s health concerns. A 24-member executive board with seven elected officers governs the ACOG, which is recognized as a nonprofit 501(c)(3) corporation. The organization is divided into nine geographic districts and an armed forces district, each of which elects its own chair, vice chair, and advisory council to provide for local or regional needs. ACOG’s national office in Washington employs a staff of 200. At the beginning of every year, ACOG’s Governmental Relations Committee identifies the organization’s primary legislative priorities and works to achieve its national, state, and local political goals. In 2002, ACOG joined Doctors for Medical Liability Reform (DMLR), a coalition of more than 200,000 practicing medical specialists dedicated to protecting patients’ access to healthcare by promoting passage of federal medical liability reform legislation. See Also: Gynecologist; Gynecology; Obstetrician/Gy-
necologist; Obstetrics.
Bibliography. American College of Obstetricians and
Gynecologists, www.acog.org (cited June 2006); Charles R. B. Beckmann, et al., Obstetrics and Gynecology, 4th ed. (Lippincott Williams & Wilkins, 2002); Paul D. Chan and Susan M. Johnson, Gynecology and Obstetrics (Current Clinical Strategies Publishing, 2005); Alan H. DeCherney and Lauren Nathan, Current Obstetric & Gynecological Diagnosis & Treatment (McGraw-Hill, 2002); Victor Y. Fujimoto, et al., Appleton & Lange’s Review of Obstetrics and Gynecology (McGraw-Hill, 1999); Eric E. Sauerbrei, Khanh T. Nguyen, and Robert L. Nolan, A Practical Guide to Ultrasound in Obstetrics and Gynecology (Lippincott Williams & Wilkins, 1998). Ben Wynne, Ph.D. Gainesville State College
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American College of Occupational and Environmental Medicine (ACOEM) Since its founding in 1916, the American College of Occupational and Environmental Medicine (ACOEM) has endeavored to promote the overall health and safety of workers, workplaces, and environments through preventive medicine, clinical care, research, and education. ACOEM defines occupational and environmental medicine as a special field of medicine that is concerned with preventing and managing work-related and environmental injuries, illnesses, and disability and with promoting the health and productivity of workers and their families and communities. The chief tasks of the occupational health professional are to treat jobrelated diseases and recognize and resolve hazardous working conditions. The environmental health professional must maintain up-to-date knowledge of new environmental elements that threaten public health, identify pollution and environmental activities that pose health hazards, and work for resolutions to environmental problems. ACOEM has a membership of more than 5,000 healthcare professionals. The major goals of ACOEM are to educate health professionals and the public on occupational and environmental issues of concern, stimulate research in the field of occupational and environmental medicine, enhance the quality of medicine offered by occupational and environmental health professionals, and guide relevant public policy in ways that enhance the field of occupational and environmental health. The national headquarters is located at 25 Northwest Point Boulevard, Suite 700, Elk Grove Village, Illinois. Information is available by telephone (847-818-1800) or over the internet (www .acoem.org). ACOEM is composed of 31 societies located in the United States and Canada. In the spring, members of ACOEM come together for the American Occupational Health Conference. The State-of-the-Art Conference is held each fall. In addition to these annual conferences, ACOEM offers continuing education courses whose subjects range from drug and alcohol testing to preparation for the Board Review in Occupational Medicine. Information on current research is published monthly in the Journal of Occupational and Environmental Medicine, and
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American College of Physicians (ACP)
books such as Occupational Medicine Practice Guidelines are published periodically. ACOEM research covers a range of topics related to the workplace and the environment, including mold, noise-induced hearing loss, depression screening, and reproductive hazards. ACOEM members are kept up to date on the activities of the organization through regular newsletters. Advocacy is extremely important to occupational and environmental health professionals, and the ACOEM maintains a presence in Washington, D.C., so that advocates are in a position to influence decisions that impact worker and public health. Advocates at the state level are involved in lobbying various state and local legislatures to protect the interests of the public and occupational and environmental professionals. ACOEM periodically issues press releases to keep the public informed about relevant occupational and environmental issues. In November 2006, for instance, a press release called public attention to a special December issue of the Journal of Occupational and Environmental Medicine, which focused on exposure to particles that increased the risk of lung cancer. Workers exposed to carbon black, commonly used in rubber and printing industries, were considered particularly vulnerable. In June 2006, another ACOEM press release urged occupational health professionals to work toward modifying health risks such as smoking and obesity in order to improve worker health and reduce healthcare costs.
Guide to the Medical Field (American Medical Association, 1995). Elizabeth R. Purdy Independent Scholar
American College of Physicians (ACP) The American College of Physicians (ACP) is a national organization of 120,000 physicians who focus on the prevention, detection, and treatment of illnesses in adults. Members include internists, internal medicine subspecialists, medical students, residents, and fellows. The subspecialties sponsored by ACP include cardiology, gastroenterology, nephrology, endocrinology, hematology, rheumatology, neurology, pulmonary disease, oncology, infectious diseases, allergy and immunology, and geriatrics. Since its establishment in 1915, ACP has worked toward promoting both the science and practice of medicine. A sister organization, the American Society of Internal Medicine (ASIM), was established to focus chiefly on the financial aspects of medicine. In 1998 the two groups merged into ACP-ASIM. In 2003, however, the organization opted to drop the ASIM, reestablishing itself as the American College of Physicians. National
See Also: Environmental Health; Environmental Medi-
cine; Environmental Protection Agency (EPA); Occupational Health; Occupational Injuries; Occupational Medicine; Occupational Safety and Health Administration (OSHA). Bibliography. American College of Occupational and
Environmental Medicine, www.acoem.org (cited December 2006); Stephen Bonner and John Harrison, Dangerous Trades: History of Health and Safety at Work (Thoemmes Continuum, 2004); Kristine Gebbie et al, eds., Who Will Keep the Public Healthy? Educating Public Health Professionals for the 21st Century (National Academy Press, 2003); David Koh, et al., eds., Textbook of Occupational Medicine Practice (World Scientific Publishing Company, 2001); Earl Wysong, High Risks and High Stakes: Health Professionals, Politics, and Policy (Greenwood, 1992); Lorri A. Zipperer, ed., The Health Care Almanac: A Resource
The 120,000 members of the American College of Physicians focus on illness and disease prevention, detection, and treatment.
headquarters is located at 190 North Independence Mall, West, Philadelphia, Pennsylvania. Information on ACP is available by telephone (800-253-1546) or through the Web site (www.acponline.org). Offices of Government Affairs, Medical Laboratory Evaluation, Proficiency Testing, and Practice Management are based in Washington, D.C., at 2001 Pennsylvania Avenue, NW. ACP governance is provided by an elected Board of Regents, and various committees and the Board of Governors serve as advisers. The Board of Governors is composed of 79 members from chapters and regions in the United States, Canada, Mexico, Central and South America, and Japan. Membership in the ACP, which is multilevel according to degrees and achievements, is separated into Medical Student, Associate, Member, Fellow, Honorary Fellow, and Master. The Annals of Internal Medicine is published twice a month to keep members up to date on current research and relevant issues. The ACP Journal Club capsules the most important articles from an internal medical perspective from over 100 medical journals, and ACP Observer serves as a monthly newsletter. The studentoriented newsletter, IMpact, is also published monthly. In addition, ACP publishes a number of books, including the major reference tool, ACP Medicine. Research and training are offered at an annual meeting at which more than 200 scientific papers are presented. Opportunities for continuing education courses are vast, and ACP offers more than 50 postgraduate programs each year, including MKSAP 14, the Medical Knowledge Self-Assessment Program, and the Clinical Skills Program. ACP also offers MKSAP for Students and an InTraining Examination to serve as student assessment tools. Members may access testing materials on DVD and at the ACP Web site. Promoting professionalism is a significant focus for ACP. For instance, the Center for Practice Innovation is responsible for promoting high-quality healthcare that is responsive to economic challenges. The Center for Ethics and Professionalism is charged with promoting the ethical practice of medicine while enhancing the quality of patient care. The ACP Practice Management Center, aided by the ACP Web site, serves as a resource guide for healthcare professionals. The ACP Foundation supports education, research, service, and professionalism. National and international proficiency testing is provided by the Medical Laboratory Evaluation Program.
American College of Physicians (ACP)
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Advocacy is an essential element in protecting the interests of both the public and internists. Therefore, ACP is involved in an ongoing relationship with members of Congress and various government agencies to protect the public and promote the interests of internists. More than 60 position papers have been developed to aid advocates in protecting the organization’s and members’ interests. ACP also sponsors the Legislative Action Center (LAC) via the official Web site, providing practical support for members who are interested in particular legislation. Working directly from the ACP site, members may send letters, e-mails, or faxes to members of Congress. If they wish, they can utilize talking points and sample letters provided by ACP. ACP has been heavily involved in advocating for greater access to healthcare in the United States. Citing a recent study, ACP contends that 70 percent of uninsured Americans in poor health and almost half of those in fair health have not seen a doctor in the previous year. These individuals may die if chronic conditions such as hypertension and diabetes remain untreated. One-fifth of all self-employed Americans have had no health coverage for more than a year. ACP argues that expanded access to healthcare will result not only in healthier Americans, but also in a reduction in the total burden of illness facing the country. In a public statement approved by the Board of Regents in October 2000, ACP lambasted the national government, arguing that access to healthcare should be a right rather than a luxury. ACP actions on such issues include a public action campaign to inform decision makers, political candidates, and the general public about the adverse effects of having no health insurance. See also: America Academy of Family Physicians
(AAFP); American Association for Health Education (AAHE); Healthcare, U.S. and Canada; International Center for Equal Healthcare Access.
Bibliography. American College of Physicians, www
.acponline.org (cited January 2007); American College of Physicians, “No Health Insurance? It’s Enough to Make You Sick,” www.acponline.org/uninsured/lack-contents .htm (cited January 2007); John Maynard and Douglas Maynard, eds., Communication in Medical Care: Interaction between Primary Care Physicians and Patients (Cambridge
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American College of Preventive Medicine (ACPM)
University Press, 2006); Earl Wysong, High Risks and High Stakes: Health Professionals, Politics, and Policy (Greenwood, 1992); Lorri A. Zipperer, ed., The Health Care Almanac: A Resource Guide to the Medical Field (American Medical Association, 1995). Elizabeth R. Purdy, Ph. D. Independent Scholar
American College of Preventive Medicine (ACPM) Founded in 1954 and headquartered in Washington, D.C., the American College of Preventive Medicine (ACPM) is the leading professional organization for physicians dedicated to disease prevention and health education. The organization actively promotes the practice, teaching, and research of preventive medicine and its members are committed to disease prevention and the promotion of health in the individual, the community, and the nation. The ACPM’s more than 2,000 members hold clinical, research, teaching, and administrative positions in managed health organizations, public agencies, various parts of the medical industry, and in medical schools. Many serve on ACPM committees and task forces and represent the organization at national forums, contributing to the role of the ACPM as a primary national resource with regard to disease prevention and the promotion of health in the United States. The organization works in association with a number of public and private concerns to strengthen the practice of preventive medicine, including the Centers for Disease Control and Prevention, the Health Resources and Services Administration, the National Heart, Lung, and Blood Institute, the National Cancer Institute, and the Agency for Toxic Substances and Disease Registry. Among the ACPM’s primary functions are the development and advocacy of public policies that are consistent with current scientific research and trends of preventive medicine. In so doing, the college analyzes and responds to legislation related to preventive medicine and creates policy statements and strategies to mobilize its membership. The ACPM also educates lawmakers with regard to preventive medicine issues
and promotes its members to serve on federal advisory boards and panels. Among the primary policy issues with which the college is concerned are the financing for preventative maintenance residency programs, tobacco prevention, improving patient safety, bioterrorism threats, federal funding for prevention programs, and improvements in preventative safety products and services. The ACPM is accredited by the Accreditation Council for Continuing Medical Education (ACCME) to provide continuing medical education for physicians, and as such the organization provides many opportunities for its members. Each year, the college’s members participate in national and regional meetings where they receive continuing education credit as they exchange the latest information available on preventive health medicine. The ACPM’s education committee oversees the development of educational materials for its membership, including internetbased activities, and the dissemination of information on a national basis. A board of directors that includes some of America’s most respected healthcare professionals governs the ACPM. The organization is the cosponsor, along with the Association of Teachers of Preventive Medicine, of the American Journal of Preventive Maintenance, which contains original, peer-reviewed articles along with reviews, critical commentaries, and editorials on all aspects of preventive medicine. Twice a month, the ACPM publishes ACPM Headlines, an electronic newsletter. See Also: Agency for Toxic Substances and Disease Reg-
istry (ATSDR); Centers for Disease Control and Prevention (CDC); Health Resources and Services Administration (HRSA); National Cancer Institute (NCI); National Heart, Lung, and Blood Institute (NHLBI). Bibliography. American College of Preventive Medicine,
www.acpm.org (cited July 2006); Richard S. Lang and Donald D. Hensrud, eds., Clinical Preventive Medicine (American Medical Association, 2002); Geoffrey Rose, The Strategy of Preventive Medicine, reprint edition (Oxford University Press, USA, 1994); U.S. Preventative Service Task Force, www.ahrq.gov/clinic/uspstfix.htm (cited July 2006). Ben Wynne, Ph.D. Gainesville State College
American College of Sports Medicine (ACSM)
American College of Sports Medicine (ACSM) The American College of Sports Medicine (ACSM) was founded in New York City in 1954 during the annual meeting of the American Association for Health, Physical Education, and Recreation (AAHPER). The following year, the organization was incorporated in Washington, D.C., and in 1961, permanent national offices for the ACSM were established in Philadelphia. In 1984 the organization’s headquarters relocated to Indianapolis, Indiana. Today, the college is the largest sports medicine and exercise science organization in the world, with more than 20,000 members internationally. The group’s primary mission involves the promotion and integration of scientific research, education, and practical applications of sports medicine and exercise science to maintain and enhance physical performance, fitness, health, and quality of life. Because they work in a wide variety of medical specialties, allied health professions, and scientific disciplines, the college’s members are able to serve as leaders in the diagnosis, treatment, and prevention of sports-related injuries and the advancement of the science of exercise. One of the chief functions of the ACSM is to provide and promote continuing education for its membership. The college currently endorses almost 200 annual conferences that extend CEC and CME credit to individuals seeking credit hours, including a wide range of programs worldwide. The ACSM also hosts its own national and regional meetings that provide its members with continuing education and networking opportunities. Through the ACSM, members can receive a number of health and clinical certifications such as Certified Personal Trainer, Health/Fitness Instructor, Exercise Specialist and Registered Clinical Exercise Physiologist. Since 1984, the ACSM Foundation has served as the fund-raising arm of the college, actively seeking corporate sponsorship as well as donations from ACSM members and the general public. The foundation maintains several endowments and offers research grants to student members as well as new and senior investigators in fields such as injury prevention, weightlessness and space physiology, exercise and aging, exercise and
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cardiovascular disease, and the relationship between exercise and heart rate. In an effort to disseminate information to its members and the American population in general, the ACSM sponsors a number of publications. Medicine and Science in Sports and Exercise is the College’s official monthly journal and the leading multidisciplinary journal in the field. It includes original scientific and clinical papers as well as reports on current research. Exercise and Sport Sciences Reviews is published quarterly, and includes topical information for students, professors, clinicians, and scientists. The college also publishes a bimonthly electronic news magazine, periodic news releases, brochures, position stands, and a great deal of educational material for its members.
ACSM members serve as leaders in the diagnosis, treatment, and prevention of sports-related injuries.
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American College of Surgeons (ACS)
See also: American Council for Fitness and Nutrition
(ACFN); Exercise/Physical Fitness; Sports Injuries.
Bibliography. American College of Sports Medicine,
www.acsm.org (cited July 2006); Peter Brukner and Karim Khan, Clinical Sports Medicine (McGraw-Hill, 2002); Mike Mcnamee, Philosophy and the Sciences of Exercise, Health and Sport: Critical Perspectives on Research Methods (Routledge, 2005); Pierre Rouzier, et al., The Sports Medicine Patient Advisor (Sportsmed Press, 2004); Jerry R. Thomas and Jack K. Nelson, Research Methods in Physical Activity (Human Kinetics, 2001). Ben Wynne, Ph.D. Gainesville State College
American College of Surgeons (ACS) Located in Chicago, Illinois, the American College of Surgeons (ACS) was founded in 1913 to improve the quality of care for surgical patients by setting high standards for surgical education and practice. The organization currently has around 70,000 members, almost 4,000 of whom live outside the United States. Established members of the organization are referred to as Fellows, while surgeons who are just beginning their practice but meet specific requirements for membership are referred to as Associate Fellows. A 19-member Board of Regents, which includes some of America’s most respected surgeons, governs the ACS. The College maintains numerous committees whose members are leading surgical specialists in their field who study specific surgical issues and make informed recommendations. At the local level, the ACS membership is organized into 100 chapters, 35 of which operate outside the United States. The activities of the college are wide and varied. The ACS serves as the sponsoring organization for the Residency Review Committee for colon and rectal surgery, neurological surgery, otolaryngology, plastic surgery, thoracic surgery, and urology and sponsors several scholarship programs related to postdoctoral education in surgery. The organization also conducts various programs through its Commission on Cancer aimed at improving the care of cancer patients. Through its
Committee on Trauma, the ACS works to improve the care of critically ill patients before, en route to, and during hospitalization. The College sponsors training courses in emergency care for ambulance personnel and courses for physicians related to improving the overall care of trauma victims. In its role as an advocate, the college analyzes socioeconomic, legislative and regulatory issues related to surgery and surgeons, issues policy statements on a variety of topics, and works with elected officials and federal agencies to help meet the needs of its members. As a public service, the ACS disseminates useful information to patients including general information designed to help them make informed decisions concerning their healthcare options and surgical procedures. The American College of Surgeons is accredited by the Accreditation Council for Continuing Medical Education (ACCME) to sponsor continuing medical education for physicians. The College offers a variety of courses to its members and has established the Surgical Education and Self-Assessment Program (SESAP) to provide practicing surgeons with an excellent resource for lifelong learning. The ACS also holds national and regional meetings and other workshops each year that provide its members with a wide range of options for earning CME credit and for networking with other professionals in their field. The Journal of the American College of Surgeons (JACS) is the official scientific publication of the ACS. JACS is a monthly, peer-reviewed journal publishing original contributions in all areas of surgery including original scientific articles, collective reviews, clinical investigations, images for surgeons, and a surgeonsat-work section. Other features include a palliative care series, evidence-based surgery abstracts and sections related to continuing medical education. The Bulletin is the college’s monthly news magazine, containing information that surgeons may find helpful in their daily practices. Articles and columns included in the bulletin may relate socioeconomic trends, legislative developments that affect surgeons, major addresses given at ACS national and regional meetings, or general news on ACS activities. In addition to its regular periodicals, the college produces and distributes more than 150 other publications on a variety of topics including manuals that focus on assessing and improving surgical procedures in
American Council for Fitness and Nutrition (ACFN)
many different areas, guidelines for trauma care, the operating room environment, and information on practice management. The ACS’s official newspaper is Surgery News, which provides concise reports on clinical meetings, federal and state politics affecting surgeons, and reports on the business aspects of surgical practice. Surgery News is published in cooperation with the International Medical News Service. See also: American Academy of Orthopedic Surgeons
(AAOS); Surgery.
Bibliography. American Board of Thoracic Surgery,
www.abts.org (cited July 2006); American College of Surgeons, American College of Surgeons Yearbook, 1995 (Award Printing Corporation, 1995); American College of Surgeons, www.facs.org (cited July 2006); American College of Surgeons Oncology Group, www.acosog.org (cited July 2006); Loyal Davis, Fellowship of Surgeons: A History of the American College of Surgeons (American College of Surgeons, 1996). Ben Wynne, Ph.D. Gainesville State College
American Council for Fitness and Nutrition (ACFN) The American Council for Fitness and Nutrition (ACFN) is a nonprofit organization that brings together health and nutrition advocates, health organizations, and food and beverage companies to work toward long-term solutions to combat the growing obesity epidemic in the United States. According to the ACFN, there is no single cause for obesity, and as a result no simple solution to the problem. The Council promotes cooperation between a cross-section of society including federal, state, and local government officials, schools, parents, institutions of higher learning, and leading members of the food and beverage industry. The ACFN represents a diverse group of organizations and is administered by an Advisory Board that includes some of America’s leading experts in the fields of nutrition, physical activity, and behavioral change. The group also works closely with other health organizations such as the American Al-
95
liance for Health, Physical Education, Recreation and Dance, the American Association of Diabetes Educators, the International Food Information Council, the National Association for Health and Fitness, and America on the Move. As part of its primary mission the ACFN seeks to highlight individuals and organizations that empower Americans to make positive, sustainable lifestyle choices that will lead to overall improvement in their health. The organization also generates awareness of current research that focuses on sustainable solutions to the obesity epidemic and serves as an information resource for health professionals, policy makers, and others who are dedicated to improving overall health and wellness in the United States. In addition to mainstream programs, the council develops materials aimed at curbing obesity in minority populations. “Food, Fun and Fitness” is an eight-week program used by leaders in the African-American community to educate children and their families on the importance of diet and nutrition. In association with private partners, the ACFN also has developed a wellness program designed to promote heath and fitness in the Hispanic-American community. Under the title Tipping the Scales on Obesity: Meeting the Challenges of Today for a Healthier Tomorrow, the ACFN has assembled a comprehensive examination of existing data and research about obesity, inactivity, and related matters to provide a greater understanding of the roots of the obesity problem and the need for constructive, practical solutions. In addition to providing a comprehensive examination of the latest studies, Tipping the Scales examines why and how multiple sections of society should work together to attack the obesity problem, evaluates a wide range of proposed solutions, and outlines elements of successful social and individual health and fitness strategies. The ACFN also publishes a monthly newsletter, Food for Thought, that includes current news items related to the organization. See also: American Obesity Association (AOA); Europe-
an Association for the Study of Obesity (EASO); Exercise/ Physical Fitness; North American Association for the Study of Obesity (NAASO); Nutrition; Nutritionist; Obesity. Bibliography. American Council for Fitness and Nu-
trition, www.acfn.org (cited July 2006); Zafra Cooper,
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American Dental Association (ADA)
Christopher G. Fairburn, and Deborah M. Hawker, Cognitive-Behavioral Treatment of Obesity: A Clinician’s Guide (Guilford, 2004); Lance Levy, Understanding Obesity: Five Medical Causes (Firefly Books Ltd., 2000); National Association for Health and Fitness, www.physicalfitness .org (cited July 2006); North American Association for the Study of Obesity, www.naaso.org (cited July 2006); Thomas A. Wadden and Albert J. Stunkard, eds., Handbook of Obesity Treatment (Guilford, 2004). Ben Wynne, Ph.D. Gainesville State College
American Dental Association (ADA) The first dental college in the United States was established in 1840 as the Baltimore College of Dental Surgery in Maryland. On August 3, 1859, 26 representatives from existing dental associations met in Niagara Falls, New York, and established the American Dental Association. By 1880, 28 dental schools were operating in the United States. Over the following decade, that number reached 100. In 1897, ADA merged with the Southern Dental Association, becoming the National Dental Association (NDA). In 1922, members chose to resume the name American Dental Association. National headquarters is located at 211 East Chicago Avenue in Chicago, Illinois. Information is available by telephone (312-440-2500) or on the internet (www.ada.org). The ADA is guided by a well-defined set of principles that include the following: Good oral health is an essential element in quality of life and overall health; the interests of public health and dentistry are closely linked; scientific principles and clinical judgment must guide oral healthcare; prevention is the key to good oral health; excellence in education depends on lifelong learning; and recruitment of skillful and dedicated staffs is necessary to a successful dental practice. ADA governance is provided through the House of Delegates, which is managed by the Board of Trustees. Eleven councils representing subfields of dentistry make recommendations on policy. Education and research have always been key elements in achieving the ADA mission of promoting
good dental health, and ADA offers accreditation training for dental laboratory technicians, dental hygienists, and dental assistants. As early as 1929, a third of the budget was designated for research purposes. In 1964, the ADA Health Foundation was founded to promote dental health research and education. Findings on current research and information on relevant issues is published in the Journal of American Dental Association (JADA), and information on events and issues is provided in ADA News. The ADA Health Foundation, which encompasses the ADA Relief Fund, the ADA Endowment and Assistance Fund, and the ADA Emergency Fund, is the charitable arm of ADA. The purpose of the foundation is to fund grants for research, education, and access to dental care. A relief fund is also available for dentists and their families whenever a dentist becomes unable to practice because of injury, illness, or advanced age. Other grants are available for disaster relief. The foundation also provides 27 percent of the funding for the Paffenbarger Research Center (PRC) based in Gaithersburg, Maryland. Additional funding for PRC is received from the National Institute of Standards and Technology (40 percent) and through grants from the National Institutes of Health (33 percent). PRC researchers are on the cutting edge of dental technology and have been involved in developing such products as improved high-speed drills, protective tooth sealants, and more natural-looking filling materials. ADA has a long history of promoting good oral health among American children. In 1934, for instance, ADA joined the U.S. Public Health Service in providing dental examinations to 1.5 million children in 26 states. During the following decade, National Children’s Dental Health Week was instituted. Fluoridation of water was endorsed in 1950. In 2003, Give Kids a Smile Day became a regular part of National Children’s Dental Health Month. Advocacy is another essential element in protecting the interests of the public and the dental profession. In the 1960s, the focus of advocacy efforts was on extending dental coverage of the poor through Medicare and Medicaid programs and on support for the Health Professions Education Act. Today, a major focus is universal access to dental care. Lobbying has not been limited to legislators and American public officials. In 1955, ADA lobbied the World Health Organization to establish a dental unit.
American Dental Hygienists’ Association (ADHA)
See also: American Association of Orthodontists (AAO);
American Dental Hygienists’ Association (ADHA); Dental Health. Bibliography. American Dental Association, www.ada.
org (cited January 2007); Robert W. McCluggage, A History of the American Dental Association (American Dental Association, 1959); Peter A. Mossey, et al., Essential Skills for Dentists (Oxford University Press, 2006); Earl Wysong, High Risks and High Stakes: Health Professionals, Politics, and Policy (Greenwood, 1992); Lorri A. Zipperer, ed., The Health Care Almanac: A Resource Guide to the Medical Field (American Medical Association, 1995). Elizabeth R. Purdy, Ph.D. Independent Scholar
American Dental Hygienists’ Association (ADHA) Founded in 1923 in Cleveland, Ohio, the American Dental Hygienists’ Association (ADHA) is today headquartered in Chicago, Illinois, and represents the professional interests of more than 120,000 registered dental hygienists in the United States. The organization’s primary focus is to improve the public’s overall health by advocating the art and science of dental hygiene, promoting universal access to quality oral healthcare, increasing awareness of the cost-effectiveness of disease prevention through oral healthcare, and promoting the highest standards of dental hygiene education, research, and practice. From an organizational standpoint, the ADHA is composed of almost 400 local dental hygiene associations, known as component organizations, that provide the most direct, hands-on activities for the membership. The component organizations implement community service programs and education sessions and offer ideas and information about state and national policies. Within the same framework state dental hygiene associations serve the component groups within their jurisdiction by keeping them informed about national policies and programs, and by monitoring legislation. At the national level, the ADHA represents the interests of all dental hygienists and provides edu-
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cational and professional development programming. The national organization is divided into 12 geographic districts, each of which represents a collection of state groups. The ADHA is governed by a Board of Trustees that includes some of the most respected professionals in the field. The ADHA Institute for Oral Health is a foundation created to provide funding for educational scholarships, fellowships, research grants, and community service grants to dental hygienists throughout the United States. All Institute programs are funded directly by individual and corporate donors. The ADHA Institute for Oral Health relies on the continued support of ADHA members and organizations, dedicated oral health professionals, and corporate supporters. The ADHA’s communication division disseminates a great deal of information through a variety of publications. Access is an informative, four-color magazine that focuses on health and practice news, professional concerns, and legislative developments. Published 10 times annually, it provides current news on issues that are important to dental hygienists, such as managed care, multiple practice settings, infection control, genetic engineering, women’s health, product news, new technology, and periodontal trends. Published quarterly online, the Journal of Dental Hygiene (JDH) is the ADHA’a official scientific organ, providing original research conducted and presented by many of America’s leading dental hygienists. The JDH also publishes a regular selection of continuing education courses approved by state dental boards. Twice a year, the ADHA publishes Information Network, a newsletter for national, component, and constituent leaders. In addition to its regular periodicals, the ADHA publishes a variety of consumer fact sheets on subjects related to oral care, such as nutrition, disease transmission, tobacco-related issues, and what to expect during a dental hygiene appointment. See also: American Association of Orthodontists (AAO);
American Dental Association (ADA); Dental Health.
Bibliography. American Dental Hygienist Association,
www.adha.org (cited July 2006); Michele Leonardi Darby, Mosby’s Comprehensive Review of Dental Hygiene (Mosby, 2006); Michele Leonardi Darby and Margaret Walsh, Dental Hygiene—Theory and Practice (Saunders, 2003); Christina
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American Diabetes Association (ADA)
B. Debiase, ed., Dental Hygiene in Review (Lippincott Williams & Wilkins, 2001); Bonnie L. Kendall, Opportunities in Dental Health Careers (VGM Career Horizons, 2001); Esther M. Wilkins, Clinical Practice of the Dental Hygienist (Lippincott Williams & Wilkins, 2004). Ben Wynne, Ph.D. Gainesville State College
American Diabetes Association (ADA) The American Diabetes Association was founded in 1940 to serve the needs of diabetics and their support teams and to promote the interests of medical professionals who work with diabetics. The membership is made up of interested members of the general public and health professionals. The focus of ADA is on diabetes research, disseminating information about the disease, and advocacy. The stated mission is to prevent and cure diabetes and to improve the quality of life for diabetics. ADA has chapters in all states and in the nation’s capital. The national headquarters is located at 1701 North Beauregard Street, Alexandria, Virginia. Information on the organization is available by telephone (800-DIABETES), via the internet (www.diabetes.org), or through state and community offices. The human body requires insulin to convert food into energy, but insulin is not effectively produced in individuals suffering from diabetes. In the United States today, 20.8 million children and adults have diabetes. Diabetes may be a result of genetics or lifestyle, or both. Approximately 6.2 million individuals suffering from diabetes have never been diagnosed and are receiving no treatment. Left untreated, diabetics may go into diabetic comas and die. Generally, treatment consists of insulin taken orally or in shots, and lifestyle changes. Diabetics need to monitor their blood sugar levels at intervals throughout the day. Diagnostic tools include the Fasting Plasma Glucose (FPG) Test and the Oral Glucose Tolerance Test (OGTT). FPG is recommended by ADA because it is easier, faster, and less expensive. A fasting level of 126mg/dl or higher is indicative of diabetes. Tests may reveal that an individual is pre-diabetic, a condition that affects some
54 million Americans. Lifestyle changes and careful monitoring by health professionals may prevent prediabetes from developing into full-blown diabetes. African Americans, Latinos, Native Americans, Asian Americans, and Pacific Islanders are more likely than other Americans to develop diabetes. There are three major types of diabetes. Type 1, which affects 5 to 10 percent of Americans, is a result of the body’s inability to produce insulin. Type 2, which is the most common form of diabetes, occurs when the body is unable to effectively use insulin that is produced. Gestational diabetes, which affects around 4 percent of all pregnant women, generally disappears after birth. However, the condition may cause pregnancy complications and endanger the health of the fetus. Because ADA is financed by charitable donations, the leadership is committed to ensuring the ethical use of ADA funds. The Whistleblower Program serves as a tool for identifying and dealing with suspected fraud or dishonesty. Funding is also generated from diabetic-oriented products such as cookbooks, meal planners, self-care guides, and informational materials. Additional income garnered from events, fundraisers, and corporate donors allows ADA to expand its scope of services. Celebrity advocates serve the dual purpose of drawing public attention to diabetes and generating funding for ADA. Coalitions and collaborations with the American Cancer Society, the American Heart Association, the American College of Cardiology, the Diabetes Care Coalition, Remaking American Medicine, patientINFORM, and Nickelodeon are integral to ADA’s ability to protect the total health of its constituency. Through the ADA Research Foundation, efforts are focused on supporting research on preventing, treating, and curing diabetes. Between 1990 and 2005, research funding more than doubled, increasing from $18 million to $40 million. Targeted research areas include genetics, islet cell biology, immunology, diabetes education, and behavioral research. ADA researchers work closely with the diabetes researchers at the National Institutes of Health. The ADA Web site offers a wealth of material for diabetics, their caregivers, and medical professionals, including information on current clinical trials. Findings on current research are available through ADA’s online database and in Forefront Research Magazine. Lobbying legislators and government of-
American Fertility Association (AFA)
ficials is an ongoing activity at ADA. In 2006 ADA’s advocacy efforts were focused on garnering support for the Gestational Diabetes Act. See also: Diabetes; Diabetes and Pregnancy; Diabe-
tes Type I (Juvenile Diabetes); Diabetes Type II; National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK).
Bibliography. American Diabetes Association, www.
diabetes.org (cited January 2007); Ashley M. Ford, ed., Trends in Diabetes Mellitus Research (Nova Biomedical Books, 2005); Ashley M. Ford, Focus on Diabetes Mellitus Research (Nova Biomedical Books, 2006); Mark A. Sperling, ed., Diabetes Mellitus in Children (Saunders, 2005); Earl Wysong, High Risks and High Stakes: Health Professionals, Politics, and Policy (Greenwood, 1992). Elizabeth R. Purdy, Ph.D. Independent Scholar
American Fertility Association (AFA) The American Fertility Association (AFA) was founded in 1999 by Pamela Madsen with a primary goal of educating the general public about reproductive diseases and supporting families during struggles with infertility and adoption. The organization was originally founded as the American Infertility Association, but after several years, the name was altered to better reflect the positive aspects of its mission. During its first six years of existence, membership in the organization increased by more than 600 percent—from around 3,000 to over 21,000. The AFA provides a wide range of services designed to disseminate information related to medical opinions, treatment options, coping techniques, legal and insurance issues, and other concerns. One of its goals is to help couples make informed decisions throughout the infertility process. The AFA’s services focus on increasing awareness of the medical and social issues surrounding reproductive health and infertility, as well as preventative efforts targeting young people and designed to help them make informed choices about their sexual and reproductive lives. The AFA believes
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the option to pursue medical treatment for infertility should be available to all those who need treatment, not just to those with the financial resources to pay for the treatment out of pocket. As a result the association endorses state and federal legislation that will require insurers to cover the costs of appropriate medical treatment for infertility. As part of its advocacy role with regard to adoptions, the AFA actively promotes reforms in adoption law that allow for the creation of more families via adoption, and spearheads ongoing efforts aimed at improving the institution of adoption, consumer protections for adoptive families, and an easing of the financial barriers to adoption. The AFA also issues position statements on some of the more controversial aspects of fertility and reproduction in a modern, scientifically enlightened society. The AFA supports a couple’s right to choose what to do with their frozen embryos, whether it be keeping them for a future attempt at conception, donating them to another infertile couple, donating them to research, or destroying them. The association also believes that embryonic stem cells hold tremendous promise and could provide the missing link needed to cure some of the world’s deadliest diseases. The AFA supports a prohibition on cloning that is limited to reproductive uses and contains a sunset provision so that the issue can be fully examined as advances in technology warrant. The association believes a limitation on cloning should not limit research into other uses of nuclear transfer technology. The AFA also supports research into the use of somatic cell nuclear transfer (SCNT) for therapeutic cloning purposes. The AFA maintains its national headquarters in New York City, and is governed by a Board of Directors and a Medical Advisory Board that includes many of America’s leading healthcare professionals in the field. See also: Infertility; Reproductive Health (General). Bibliography. American Fertility Association, www
.theafa.org (cited July 2006); American Pregnancy Association, www.americanpregnancy.org (cited July 2006); Obgyn.net: The Universe of Women’s Health, www.obgyn. net (cited July 2006). Ben Wynne, Ph.D. Gainesville State College
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American Geriatrics Society (AGS)
American Geriatrics Society (AGS) According to government estimates, there were 15,542,288 males and 21,653,879 females over the age of 65 living in the United States in 2006, comprising 12.5 percent of the total population. By 2030, as the baby boomer generation ages, elderly Americans are expected to make up 20 percent of the population. Many Americans over the age of 65 suffer from various diseases, and large numbers of America’s elderly are unable to live without assistance. Currently, a fifth of Medicare recipients suffer from five or more chronic conditions such as hypertension, diabetes, cardiovascular disease, and arthritis. Even those who have no serious health problems are aware that they may need medical and/or physical help as they age. Treating the elderly as a population with distinct medical and psychological needs has led to an increased interest in the study of geriatric medicine. The American Geriatrics Society (AGS) was established in 1942 to promote the interests of the elderly and support health professionals involved in the field of geriatrics. One of the 20 charter members was Dr. Ignatz Leo Nascher, who is credited with coining the term geriatrics. Membership eligibility was based on professional interest in the field. The following year, the first scientific conference was held in New York City. AGS national headquarters is located in the Empire State Building, 350 Fifth Avenue, Suite 801, in New York City. Information on AGS is available by telephone (212-3081414) and via internet (www .americangeriatrics.org). The mission of AGS is to improve the health, independence, and quality of life for all older Americans. This mission is fulfilled through clinical practice, professional and public education, and research and public policy. In order to become a geriatrician, a physician must complete a year of geriatric training in addition to the training required for physicians entering family practice or internal medicine. As Americans continue to age in increasing numbers, the ratio of physician to patient is expected to decrease so that by 2030, there will be only 1 geriatrician for every 7,665 elderly patients. Geriatricians generally take a holistic approach to patient care, working with nurse practitioners, psychiatrists, surgeons, pharmacists, social workers, and physical and occupational therapists.
Information on AGS research is regularly published in the Geriatrics Review Syllabus, Journal of the American Geriatrics Society, Annals of Long-Term Care, and Clinical Geriatrics. Clinical practice guidelines are available on various subjects, including persistent pain, diabetes, and falls. Geriatrics at Your Fingertips, a major resource tool for those interested in healthcare for the elderly, sells some 15,000 copies each year. Education is an ongoing process at AGS, and the Association of Directors of Geriatric Programs engages in advancing and supporting various programs in geriatric medicine at accredited medical schools. A threeyear training program for administrators of geriatric programs is offered through the Hartford Geriatrics Leadership Development Program. Significant data on geriatrics are generated through the joint efforts of the Association of Directors of Geriatric Academic Programs and the Cincinnati Institute for the Study of Health. This research is funded by the Donald W. Reynolds Foundation and the John A. Hartford Foundation. Findings from this study have been published in Geriatric Medicine: A Clinical Imperative for an Aging Population and in Caring for Older Americans: The Future of Geriatric Medicine. A quarterly newsletter available on the AGS Web site provides regular updates on the longitudinal study. See also: Geriatrics; National Institute on Aging (NIA). Bibliography. American Geriatrics Society, www.amer-
icangeriatrics.org; Julie K. Gammack and John E. Morley, eds., Geriatric Medicine (Saunders, 2006); Sue V. Saxon and Mary Jean Etten, Physical Change and Aging: A Guide for the Helping Professions (Tiresias Press, 2002); Lynn M. Tepper and Thomas M. Cassidy, eds., Multidisciplinary Perspective on Aging (Springer, 2004). Elizabeth R. Purdy, Ph.D. Independent Scholar
American Health Care Association (AHCA) Founded in 1948 and headquartered in Washington, D.C., the American Health Care Association (AHCA) is a nonprofit federation of affiliated state
health organizations that together represent more than 10,000 nonprofit and for-profit assisted living, nursing, developmentally-disabled, and subacute care providers who attend to the needs of more than 1.5 million elderly and disabled individuals nationally. The ultimate goals of the group revolve around providing quality care to the nation’s elderly and disabled who are served by AHCA members. As a result, the association and its affiliates are advocates for those who, because of disability, trauma, illness, or social needs, require a long-term healthcare setting. The AHCA also promotes public policies that balance economic and regulatory principles to promote quality care as well as quality of life. The National Center for Assisted Living (NCAL) is the assisted living voice of the AHCA. Through the AHCA’s national network of state affiliates, the NCAL supports lobbying efforts at the national level and helps state affiliates promote their agendas through their own state legislatures. Because assisted living receives a great deal of attention and scrutiny at the national level from Congress, the Department of Labor, the General Accounting Office, the Institute of Medicine and the Department of Health and Human Services, the AHCA, and the NCAL work together to offer federal representation for its members. They also collaborate to maintain the Mark A. Jerstad Information Resource Center, which contains a collection of materials about assisted living and a research division that conducts studies to develop information and data that are issued to Wall Street analysts, national media, and policy makers. The AHCA/NCAL offers a variety of professional publications to its members, including FOCUS, a monthly newsletter. FOCUS covers the latest business news, trends, regulatory activity, and legislative developments and provides examples of some of the best practices in assisted living residences across the nation. Provider is a solution-oriented monthly magazine that offers readers pragmatic, hands-on guidance regarding the entire long-term care continuum, including extensive coverage of assisted living issues. The NCAL’s enewsletter, NCAL Connections, is dedicated to keeping members informed of developing events in assisted living and at NCAL. It is distributed to the association’s leadership, state affiliates, and associate business members. The AHCA/NCAL Gazette is a daily publication designed to keep state association leaders informed
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of state and national news that affects long-term care professionals so that they can incorporate this information into their decision making at the state level. AHCA Notes is a monthly newsletter that updates NCAL members on long-term care trends as well as state and national regulatory and legislative activity. In addition to state and local meetings, the AHCA also holds an annual convention and, in cooperation with several other professional groups, sponsors National Assisted Living week each September to raise public awareness of the assisted living profession. See also: Administration on Aging (AoA); American Ge-
riatrics Society (AGS); American Society on Aging (ASA).
Bibliography. American Health Care Association, www
.ahca.org (cited August 2006); National Center for Assisted Living, www.ncal.org (cited August 2006).
Ben Wynne, Ph.D. Gainesville State College
American Heart Association (AHA) In 1915, a group of physicians and social workers who were concerned about the high death rate from heart disease and the lack of information on this common disease met in New York City to form the Association for the Prevention and Relief of Heart Disease. The group subsequently conducted landmark studies in New York and Boston. As interest in heart disease increased, six cardiologists from various organizations banded together to create the American Heart Association in 1924. The stated mission of the AHA is to reduce disabilities and death from both cardiovascular disease and stroke. National headquarters for the AHA and the American Stroke Association are located at 7272 Greenville Avenue in Dallas, Texas. AHA also maintains 12 regional offices. Information is available by telephone (800-AHA-USA-1 or 888-4-STROKE) and on the AHA Web site (www.americanheart.org). More Americans die every year from coronary heart disease than from any other reason, and stroke is the number three killer of Americans. While heart attacks are sometimes so intense that there is little
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American Lung Association (ALA)
doubt about the cause of pain, most attacks build over time. They start with mild pain or discomfort, and many sufferers believe the pain is caused by indigestion or stress. AHA identifies three clear indications of a heart attack: chest discomfort or a squeezing kind of pressure that lasts for more than a few minutes or that goes away only to return; discomfort in one or both arms, the back, neck, jaw, or stomach; and shortness of breath that occurs with or without chest discomfort. Other impending signs of a heart attack may include breaking out in a cold sweat, nausea, or lightheadedness. Women are more likely than men to experience shortness of breath, nausea or vomiting, and back or jaw pain. Anyone experiencing these symptoms is advised to call 911 rather than getting to the hospital on his or her own, partially because individuals who arrive by ambulance receive faster treatment. Medical personnel are trained to take immediate measures that may save a person’s life. Although strokes tend to come on suddenly, they may be preceded by an indefinite period of uncontrolled hypertension, which is known as the “silent killer” because symptoms may go unnoticed or be attributed to other causes. AHA offers five warning signs of impending stroke: Sudden numbness or weakness of the face, arm, or leg, particularly if the numbness occurs on only one side of the body; sudden confusion that prevents the sufferer from communicating with others; sudden trouble seeing in one or both eyes; sudden trouble walking, dizziness, loss of balance, or coordination; and sudden severe headache with no known cause. As in the case of suspected heart attack, 911 should be called immediately because there is a window of only three hours in which a clot-busting drug may be administered to limit the possibility of stroke-related disabilities. A major reorganization of AHA in 1948 brought nonmedical volunteers with various skills into the organization, and public service announcements became a fixture on American radio later that same year. As AHA activities increased, community groups were established across the country. In 1949, the first national fund-raising campaign raised $2.7 million. These funds allowed AHA to increase endeavors in research, education, and community work. Children’s advocacy became a major focus of activity, and AHA has repeatedly stood up to the tobacco industry in the interest of public health. Other ways in which AHA supports
the public is through events, such as the annual Heart Walk, which raises public awareness of heart disease while generating funds for AHA activities. See also: Heart Attack; Heart Diseases (General); Heart
Diseases—Prevention; National Heart, Lung, and Blood Institute (NHLBI); National Institute of Neurological Disorders and Stroke (NINDS); Stroke. Bibliography. American Heart Association, www.amer-
icanheart.org (cited January 2007); Peter Mills, ed., Education in Heart, Volume 1 (BMJ, 2001); Clive Rosendorff, ed., Essential Cardiology: Principles and Practice (Humana, 2005); George J. Taylor, ed., Primary Care Management of Heart Disease (Mosby, 2000); Earl Wysong, High Risks and High Stakes: Health Professionals, Politics, and Policy (Greenwood, 1992); Lorri A. Zipperer, ed., The Health Care Almanac: A Resource Guide to the Medical Field (American Medical Association, 1995). Elizabeth R. Purdy, Ph.D. Independent Scholar
American Lung Association (ALA) In the early 20th century, tuberculosis was a leading cause of death in the United States. In 1904, the National Association for the Study and Prevention of Tuberculosis became the first nationwide voluntary health organization in the country. By 1973, that organization had evolved into the American Lung Association. In 1907, Emily Bissell began the annual tradition of Christmas seals to raise money for respiratory health. That first campaign netted $3,000. The following year, Christmas seals raised $135,000 and continued to climb. Research activities began in 1920, and X-rays and the tuberculin skin test soon became common diagnostic tools. In partnership with the U.S. Public Health Service, the association began routinely testing in workplaces and communities. Grants and fellowships were awarded to lure scientists and physicians to the field of respiratory medicine. A major breakthrough in the fight against tuberculosis occurred in the 1950s when Dr. Edith Lincoln used her grant money to discover that isoniazid, which could be
administered by mouth or by injection, could prevent complications of tuberculosis such as meningitis. By 1956, the association had expanded its research areas to include asthma, chronic bronchitis, emphysema, and other respiratory diseases. Four years later, its Board of Directors released a public warning, advising the public that “cigarette smoking is a major cause of lung cancer,” and increased efforts to educate the public about the symptoms and causes of chronic respiratory diseases. The first Action for Clean Air Committees were established in 1964. In order to mirror expanded areas of interest, the association became the National Tuberculosis and Respiratory Disease Association, and launched the antismoking campaign Kick the Habit. In 1973, the name of the organization was changed to the American Lung Association, with the stated mission of preventing lung disease and promoting lung health. National headquarters is located on the 6th floor of 61 Broadway in New York City. Information on ALA is available by telephone (800-LUNGUSA) or at the ALA Web site (www.lungusa.org). A team of registered nurses and registered respiratory therapists are on call to answer questions and provide information on topics related to respiratory health. The focus of the ALA has continued to be on asthma, tobacco control, and environmental health. ALA’s generous grant program has been responsible for major lifesaving progress in the field of lung health, such as the use of surfactant therapy with premature infants experiencing respiratory distress syndrome (RDS). In order to achieve its mission, ALA is involved in a number of ongoing projects, including the Open Airways for Schools project, which works with children who have asthma. Antismoking efforts encompass a number of control and prevention activities, such as Teens against Tobacco Use, Not on Tobacco (N-O-T), and Freedom from Smoking®. The eradication of air pollutants is a major focus of ALA’s environmental health activities. Recommendations for preventing occupational lung disease were first issued in 1980. Because minorities suffer disproportionately from certain lung diseases, ALA is involved in targeting vulnerable groups through partnerships with minority colleges and universities and with community groups. Advocacy also remains a major area of activity, and members of ALA seek to influence policy at the
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national, state, and local levels. ALA maintains an office in Washington, D.C., and organizational pressure was essential to the passage of the Clean Air Amendments of 1990, the ban against smoking on airlines, and the institution of stricter smog and soot standards. Recent activities of the ALA Action Network have involved preparing Americans for the flu season, garnering support for the Comprehensive Tuberculosis Elimination Act of 2006, and supporting the City of Baltimore’s efforts to eliminate smoking in bars and restaurants. See also: Environmental Tobacco Smoke (ETS); Lung
Cancer; National Heart, Lung, and Blood Institute (NHLBI); Smoking; Smoking Cessation; Tuberculosis. Bibliography. American Lung Association, www.lung
usa.org; Alan Derickson, Black Lung: Anatomy of a Public Health Disaster (Cornell University Press, 1998); National Heart, Lung, and Blood Institute, The Lungs in Health and Disease (National Institutes of Health, 1997); J.H. Owing, ed., Smoking and Health: New Research (Nova Biomedical Books, 2005); Frank E. Speizer, Occupational and Environmental Lung Disease (U.S. Department of Health and Public Services, 2000); Earl Wysong, High Risks and High Stakes: Health Professionals, Politics, and Policy (Greenwood, 1992); Lorri A. Zipperer, ed., The Health Care Almanac: A Resource Guide to the Medical Field (American Medical Association, 1995). Elizabeth R. Purdy, Ph.D. Independent Scholar
American Medical Association (AMA) The American Medical Association is the largest physicians group in the United States. Its mission is to bring physicians together to deal with relevant professional and public health issues. Governance is implemented through the House of Delegates, and oversight is provided by the Board of Trustees. AMA’s national headquarters is located at 515 State Street in Chicago, Illinois. Information is available by telephone (800-621-8335) or on the World Wide Web (www.ama-assn.org).
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American Medical Women’s Association (AMWA)
Nathan Smith Davis, who received his medical degree from the Medical College of Western New York at the age of 20, founded the AMA in 1847. At the first meeting, attended by 250 delegates from 28 states, the first medical code of ethics was adopted, and the standards for physician education were established. The following year, the AMA began efforts to establish the merit of antibiotic use in medicine, surgery, and obstetrics. In 1883, the AMA began publishing the Journal of the American Medical Association, and Dr. Davis served as its first editor. By 1898, the Committee on Scientific Research was established to provide grants for medical research. Eight years later, the AMA began conducting inspections of 160 medical schools. Scores were awarded on the basis of acceptable (A), doubtful (B), and unacceptable (C). In 1910, the publication of standards for medical schools led to a drastic drop in the so-called diploma mills that had been graduating ill-trained physicians. Within two years, the Federation of State Boards was set up to rate medical schools along AMA guidelines. The Women’s Auxiliary was established in 1922, and students and residents were admitted to membership in 1972. Advocacy has been an essential function of the AMA throughout its history, and the organization has maintained a physical presence in Washington, D.C., since 1943. The AMA’s first political action committee (PAC) was set up in 1961. Advocacy efforts have been instrumental in the passage of seat belt laws, the acceptance of alcoholism as an illness, the expansion of Medicare coverage, the nationwide use of the Sabin oral vaccine against polio, the implementation of smoking bans, the rise in hospice care for the terminally ill, the elimination of legal HIV/AIDS discrimination, and the increase in attention paid to family violence. Intense lobbying efforts have been directed toward reforming the American healthcare system to allow for expanded healthcare coverage. The AMA has taken a position against physician-assisted suicides and lobbied for malpractice reform. The proposed Patient Protection Act II was an AMA attempt to prevent insurance companies from infringing on patient–doctor relationships, and the organization has continued the fight for the Patient’s Bill of Rights into the 21st century. After the terrorist attacks on the United States on September 11, 2001, 3,500 doctors offered to assist in recovery efforts. Subsequently, the AMA set up its online Center for Disaster Preparedness and Medical Response.
Publications of the AMA are widely used. Current Procedural Terminology (CPT) has become the standard text on medical procedures, and the AMA Family Medical Guide is a fixture in homes throughout the United States. Other AMA publications include the AMA newsletter, amednews (www.amednews.com), and AMA Voice. Archives journals summarize relevant articles from other publications. Data collection also plays a significant role in the research capabilities of the AMA, and online databases allow patients, physicians, and other health professionals to quickly access information. See also: American College of Physicians (ACP); Ameri-
can Medical Women’s Association (AMWA).
Bibliography. American Medical Association, www
.ama-assn.org (cited January 2007); Suzanne Scott Embree, The Politics of Expertise: A Profession and Jurisdiction (New York University Press, 1973); John F. Monagle, Health Care Ethics: Issues for the 21st Century (Aspen, 1998); Howard Wolinsky and Tom Brune, The Serpent on the Staff: The Unhealthy Politics of the American Medical Association (Putnam, 1994); Earl Wysong, High Risks and High Stakes: Health Professionals, Politics, and Policy (Greenwood, 1992); Lorri A. Zipperer, ed., The Health Care Almanac: A Resource Guide to the Medical Field (American Medical Association, 1995). Elizabeth R. Purdy, Ph.D. Independent Scholar
American Medical Women’s Association (AMWA) Dr. Bertha VanHoosen founded the American Medical Women’s Association in 1915 to serve as a vehicle for protecting the interests of female physicians, who were far outnumbered by their male colleagues. The association remains the only organization in the country that is solely committed to serving female physicians and medical students. Throughout its history, AMWA has worked to improve the health of women throughout the country by empowering them to take the initiative in promoting their own good health. The current membership of some
10,000 members operates at the national, state, and local levels. Headquarters is located at 211 North Union Street, Suite 100, Alexandria, Virginia, and information on the organization is available on the AMWA’s Web site (www.amwa-doc.org). Advocacy is a key element of promoting and protecting women’s health issues, and AMWA continues to advocate the interests of women in general and of female physicians in particular. AMWA endeavors to educate the public about issues relevant to women’s health, and encourages professional advancement through continuing education and the development of enhanced expertise. AMWA also recognizes the importance of women mentoring one another and of forming strong alliances that best serve their distinct interests. AMWA’s advocacy activities support females of all ages. Recognizing the importance of sex education in protecting young people from sexually transmitted diseases (STDs) and concerned about the number of teenage pregnancies, in 2005 AMWA joined other advocates, including Planned Parenthood, the National Women’s Law Center, and the Alan Gutt macher Institute, in calling for review of the abstinence-only curricula mandated in American schools under Republican leaders since Ronald Reagan at a cost of $168 million each year. Menopausal women were the focus of AMWA’s efforts to shed greater light on the issue of hormone replacement therapy (HRT) when a 2004 study indicated that health providers and women were still confused about the advisability of using HRT, which has been linked to higher incidences of breast cancer. AMWA’s stand on the issue of hormone therapy is that it is a highly personal decision that should be made by individual women in consultation with their healthcare providers. Advocacy efforts also center on healthcare coverage for all Americans, healthcare system reform, elder care, dependent care, Medicaid reform, and reproductive health. Research is an integral part of promoting good health among American women, and AMWA’s research interests include those that affect women differently than men as well as those that predominately affect females. Among the former, smoking prevention and cessation, osteoporosis, and heart disease demand the lion’s share of attention. Among the latter, major areas of concern include violence against
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women, gender equity, breast cancer, reproductive health, and cervical cancer prevention. In the past, the Journal of the American Medical Women’s Association functioned as the only peerreviewed medical journal that dealt exclusively with women’s health issues and promoted the careers of female physicians. Although it is no longer in print, archived journals continue to serve as valuable resource tools. Newsflash, a weekly newsletter, keeps members up to date on other members, health issues, and advocacy concerns. Twice a month, the AMWA print newsletter provides more in-depth coverage of relevant issues. Members also have access to Doctor’s Digest, which is published six times a year. Each issue is dedicated to a particular area of significance to practicing physicians. See also: National Women’s Health Organization
(NWHO); Women’s Health (General).
Bibliography. American Medical Women’s Association,
www.amwa-doc.org (cited January 2007); Janice W. Lee, ed., Gender Roles (Nova Biomedical Books, 2005); Judith Lorber, Women Physicians: Careers, Status, and Power (Tavistock, 1984); Laura Lynn Windsor, Women in Medicine: An Encyclopedia (ABC-CLIO, 2002); Earl Wysong, High Risks and High Stakes: Health Professionals, Politics, and Policy (Greenwood, 1992); Lorri A. Zipperer, ed., The Health Care Almanac: A Resource Guide to the Medical Field (American Medical Association, 1995). Elizabeth R. Purdy, Ph.D. Independent Scholar
American Nurses Association (ANA) There are approximately 2.9 million registered nurses in the United States who work with other medical professionals to provide quality healthcare to the population. With a membership of 150,000, the American Nurses Association serves the interest of the nursing profession through a national organization and 54 constituent associations. ANA’s goals have always been to encourage high professional standards among its members, promote and protect
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American Obesity Association (AOA)
the welfare of nurses in their work settings, project a positive view of the nursing profession, and advocate on issues of concern to nurses and the general public. National headquarters is located at 8515 Georgia Avenue, Suite 400, Silver Spring, Maryland. Information on the organization is also available by telephone (800-274-4262) or on the World Wide Web (www.nursingworld.org). Credentialing information for nurses may be obtained by calling the American Nurses Credentialing Center at 800-284-2378. According to the ANA, the field of nursing is concerned with protecting, promoting, and optimizing health and abilities, preventing illnesses and injuries, alleviating suffering through diagnosis and treatment, and advocating the interests of individuals, families, communities, and populations. ANA is governed by a House of Delegates composed of representatives from the constituency associations and a Board of Directors. In addition to individual members, ANA has two organizational members, the Center for American Nurses and United American Nurses, AFL-CIO. Ties with other organizations strengthen ANA’s ability to promote the interests of its membership. Organizational affiliates include the American Association of Nursing and a number of groups dedicated to subfields of nursing, such as the American Association of Critical-Care Nursing, the Association of Nurses in AIDS Care, and the Association of Women’s Health, Obstetric, and Neonatal Nurses. The ANA believes that healthcare is best delivered in community-based settings, and major advocacy efforts are focused on healthcare reform. The organization maintains that the key to providing quality healthcare is expanding the role of registered nurses (RNs) and nurse practitioners in the delivery of healthcare. Federal funding for education and training is considered essential. Policy efforts of general interest are concerned with Medicare reform, the proposed Patient’s Bill of Rights, safer needle devices, and expanded access to medical care. Issues that are of particular concern to nurses include appropriate staffing, whistleblower protection for healthcare workers who report fraud and illegal medical practices, and timely and adequate reimbursement of healthcare services. ANA advocates pursue policy interests by lobbying Congress and federal government officials as well as state and local legislators and agencies. Attempts to improve the professional lives of nurses focus on
gaining collective bargaining rights and lobbying for better pay and working conditions. ANA research efforts generally concentrate on improving ways in which nurses practice their profession. Relevant publications include The American Nurse, American Nurse Today, American Journal of Nursing, Online Journal of Issues in Nursing, and textbooks on various subjects related to the education of nurses. The Code of Ethics is available at the ANA’s Web site. Free publications available for download from this site include articles on general issues, such as “Preventing Work Place Violence” and “Your Health and Safety Rights,” as well as those on education and planning that are devoted to nursing as a profession. See also: American Academy of Nurse Practitioners
(AANP); American College of Nurse-Midwives (AANM); Association of Women’s Health, Obstetric, and Neonatal Nurses (AWHONN). Bibliography. American Nurses Association, www.nurs-
ingworld.org (cited January 2007); Perle Slavik Cowen and Sue Moorhead, Current Issues in Nursing (Mosby Elsevier, 2006); Anne B. Hamric, et al., Advanced Practice Nursing: An Integrative Approach (Saunders, 2005); Lucille A. Joel, The Nursing Experience: Trends, Challenges, and Transitions (McGraw-Hill, 2006); Carol Jorgensen, Professional Issues in Nursing: Challenges and Opportunities (Lippincott, Williams, and Wilkins, 2006); Earl Wysong, High Risks and High Stakes: Health Professionals, Politics, and Policy (Greenwood, 1992); Lorri A. Zipperer, ed., The Health Care Almanac: A Resource Guide to the Medical Field (American Medical Association, 1995). Elizabeth R. Purdy, Ph.D. Independent Scholar
American Obesity Association (AOA) The American Obesity Association is the only organization on obesity that pursues the goal of preventing and treating obesity and related conditions through affecting policy decisions and educating the public. The latter includes the dissemination of information, such as the fact that even small weight losses may have
enormous health advantages, and maintaining up-todate consumer information and alerts on weight loss products and devices. The organization also serves as a resource center for legislators, government officials, media, and health professionals. Successful lobbying of decision makers has led the Social Security Administration, the Internal Revenue Service (IRS), and Medicare to treat obesity as a disease rather than as a social problem. AOA’s other focus areas deal with research and eliminating discrimination of obese individuals and the stigma associated with the disease. AOA was founded in 1995 by noted researchers Richard L. Atkinson and Judith S. Stern. The national headquarters is located at 1250 24th Street, NW, Suite 300, Washington, D.C. Information is available by telephone (202-776-7711) or via the internet (www. obesity.org). The AOA Research Foundation serves as a supporting organization, and AOA is governed by an Advisory Council and a Board of Directors. Approximately one in every three Americans is considered obese, amounting to some 60 million people. Some 64.5 percent of the total population is overweight, and the obesity of children has become an issue of international concern among developed countries. Obesity disproportionately affects low-income individuals and families whose diets are composed chiefly of low-cost foods, such as fats and starches. Since the 1960s, as the pace of life has quickened, the population of the United States has been bombarded with advertisements and media images that equate food with social acceptance. Unhealthy fast food and overly large portions combine with a lack of exercise and physically sedate working conditions to produce a plethora of health problems. Some 300,000 excess deaths in the United States occur yearly as a result of these problems, and obesity is the second leading cause of unnecessary deaths. Some $100 billion is expended annually in treating conditions related to being overweight, such as heart disease, diabetes, hypertension, stroke, gallbladder disease, and cancers of the breast, prostate, and colon. The National Institutes of Health currently allocates only 1 percent of its budget to the fight against obesity, and major AOA advocacy efforts are directed toward increasing government funds for the study of the effects of obesity on American society. AOA is also concerned about developing tools for prevention and treatment of obesity and related conditions and in understanding
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genetic links that contribute to the condition. Other efforts focus on expanding insurance coverage for the treatment of obesity and in ending the widespread discrimination against obese individuals in the workplace as well as in society as a whole. AOA has been effective in bringing about policy changes that increase the priority of obesity as a public health issue and in advancing new treatments for the disease. AOA offers ongoing support for obese Americans and works with groups ranging from Shape Up America to the American Society of Bariatric Physicians to enhance support. Corporate members involved in the battle against obesity vary from drug companies such as Merck and Pfizer to weight control brands and companies such as Slim Fast and Weight Watchers. Public awareness is further enhanced through the building of strong relationships with media, including the New York Times, Washington Post, CNN, and the BBC. See also: European Association for the Study of Obe-
sity (EASO); North American Association for the Study of Obesity (NAASO); Obesity.
Bibliography. American Obesity Association, www
.obesity.org (cited January 2007); Per Björntorp, ed., International Textbook of Obesity (Wiley, 2001); Linda A. Ferrera, ed., Focus on Body Mass Index and Health Research (Nova Science, 2006); Igor Harsch, ed., The Various Types and Treatments for Obesity (Nova Science, 2006); Evelyn B. Kelly, Obesity (Greenwood, 2006); Peter R. Ling, ed., Trends in Obesity Research (Nova Biomedical Books, 2005); Thomas A. Wadden and Albert J. Stunkard, eds., Handbook of Obesity Treatment (Guilford Press, 2002). Elizabeth R. Purdy, Ph.D. Independent Scholar
American Osteopathic Association The American Osteopathic Association (AOA) began in 1897 as the American Association for the Advancement of Osteopathy. From a committee of 16 students of Dr. Andrew Taylor Still, the organization has grown to over 36,000 members. From the early outset, the members included both men and women. The initial
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American Pharmacists Association (APhA)
first and second vice-presidents, as well as the secretary and another member of the board, were female graduates of the American School of Osteopathy. At the time of organization’s inauguration, osteopathic medicine and osteopathic physicians (doctors of osteopathy or DOs) were neither well known nor well accepted. Aside from the need for camaraderie, the members sought to increase the general and official recognition of the profession, unmask and eliminate diploma mills and their constituency, and establish educational regulations for reputable colleges of osteopathy. With the 1901 annual convention, the organization changed its name to the current one and established the official journal, Journal of the American Osteopathic Association. By then, only 14 states had laws recognizing and regulating the practice of osteopathy. Within a dozen years, 39 states had practice laws for osteopathic physicians and eight other states joined the list by 1923. The process did not occur without opposition. The American Medical Association (AMA) ruled that it was unethical for a member of their organization to consult with DOs. Despite efforts on the part of the AOA, as well as passage of such laws as the Military Appropriations Act in the 1940s and directives from the Armed Services Subcommittee in the 1950s, DOs were not accepted as U.S. military physicians until 1966. The AMA appeared to reverse its position from rejection to assimilation in the late 1950s when a contract was signed by the California Medical Association and the California Osteopathic Association to amalgamate. Rather than causing the dwindling of membership or osteopathic organizations, the event became a rallying point to increase efforts for the profession to remain independent, parallel, and distinctive. Currently, all 50 states, the District of Columbia, the United States military, and the United States Public Health Service recognize DOs as fully licensed physicians and surgeons. The AOA is the recognized body for certification of osteopathic specialists through boards representing all areas of medical practice as well as the accrediting organization for undergraduate, graduate residency, and continuing medical education processes. Osteopathic state, military, and specialty associations form component societies of the AOA with members as delegates to the governing body, the AOA House of Delegates.
SEE ALSO: Allopathy; Osteopathy.
American Osteopathic Association, www.osteopathic.org (cited February 2007); American Osteopathic Association, The American Osteopathic Association—The People and Events that Shaped Our History: A Centennial Perspective 1897–1997 (American Osteopathic Association, 1997); Barbara Petersen, “Major Events in Osteopathic History,” in Robert Ward, ed., Foundation for Osteopathic Medicine, 2nd ed. (Lippincott Williams & Wilkins, 2003). Bibliography.
Dennis J. Dowling, D.O., F.A.A.O. Independent Scholar
American Pharmacists Association (APhA) Founded in 1852 as the American Pharmaceutical Association, the American Pharmacists Association (APhA) is the largest and oldest organization of its type, representing more than 57,000 practicing pharmacists, pharmaceutical scientists, pharmacy technicians, pharmacy students, and others interested in advancing the profession. The stated mission of the organization is to provide information, education, and advocacy to help all pharmacists in the improvement of medication use and to advance patient care. The APhA House of Delegates develops policy for the organization and is comprised of state delegates as well as delegates from APhA academies and affiliated organizations, and a number of ex officio members. Each year the association sponsors a major national conference as well as a number of regional meetings. The APha devotes its energies to the advancement of patient care services as they relate to pharmacists, the expansion of overall patient access to pharmacists, and the dissemination of educational and training information that will allow all member pharmacists to improve positive health outcomes of their patients. The association also sponsors a career center to assist potential pharmacists in making informed decisions related to their career paths and information about potential employers. The APhA provides current pharmacists access to many continuing education programs, and maintains a database of the latest
American Podiatric Medical Association (APMA)
information as it pertains to specific drugs. The association is headquartered in Washington, D.C. The APhA produces a number of publications to keep its members up to date on the latest research and advances in patient care. The Journal of the American Pharmacists Association is the group’s official peer-reviewed journal. It provides information on pharmaceutical care, drug therapy, diseases, trends in pharmacy practice, and original research on a variety of subjects. The association also publishes the Journal of Pharmaceutical Sciences, which includes articles, notes, reviews, and commentaries related to the physical and biological factors that affect patient access to drugs and studies on various methods to maximize the effectiveness of drugs, dosages, and delivery systems. Pharmacy Today is a monthly news magazine that includes extensive information on medications, therapies, and patient care, and also tracks healthcare related policy, legislation, and regulation at the state and federal levels. Published bimonthly, Student Pharmacist Magazine is the nation’s premier publication for those seeking to pursue a career in pharmacy. It provides news and information about career planning as well as career advice from practicing professionals, practice-setting profiles, student viewpoints on current issues, the importance of political advocacy, general tools for improved pharmacist-patient communication, and information related to current technology. APha DrugInfoLine is a monthly newsletter of interpreted drug and pharmacotherapeutic information designed raise awareness and keep pharmacists current on the latest trends in the biomedical literature. See also: Pharmacist; Pharmacology; Pharmacy. Bibliography. American Pharmacists Association, www
.aphanet.org (cited July 2006); Dick R. Gourley and James C. Eoff, eds., The APHA Complete Review for Pharmacy (Castle Connolly Graduate Medical Publishers, 2006); Andrea Peirce, The American Pharmaceutical Association Practical Guide to Natural Medicines (William Morrow, 1999); Leon Shargel, et al., Comprehensive Pharmacy Review (Lippincott Williams & Wilkins, 2003). Ben Wynne, Ph.D. Gainesville State College
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American Podiatric Medical Association (APMA) Established in 1912 and headquartered in Bethesda, Maryland, the American Podiatric Medical Association (APMA) is the largest and most influential professional organization representing the interests of America’s podiatrists. Most of the 15,000 podiatrists in the United States are members of the association, and within the APMA’s umbrella of organizations are component societies representing the 50 states, the District of Columbia, Puerto Rico, and a Federal Services jurisdiction. Corporate members represent a diverse range of interests from athletics footwear producers to pharmaceutical companies. The association also works with almost two dozen affiliated or related societies. Affiliated groups include the American Academy of Podiatric Sports Medicine, the American College of Foot and Ankle Orthopedics and Medicine, the American College of Foot and Ankle Pediatrics, the American College of Foot and Ankle Surgeons, the American College of Podiatric Radiology, the American Society of Podiatric Dermatology, and the American Society of Podiatric Medicine. The APMA’s stated mission revolves around a commitment to advancing the profession of podiatric medicine for the benefit of its members and the general public by ensuring the highest quality of foot and ankle care. Through its educational foundation, the association advances the growth and stability of podiatric medicine through the awarding of student scholarships and by creating programs to increase awareness of foot and ankle health nationwide. The U.S. Department of Education designated the APMA’s Council on Podiatric Education as the primary accrediting entity for the nation’s podiatric medical schools. In addition to developing and implementing standards and practices for the profession, the council is charged with approving residency and continuing medical education programs and certifying various specialty boards and other groups within the podiatric community. The Council on Podiatric Education serves as an autonomous accrediting agency for podiatric medical education and derives its authority from the House of Delegates of the APMA. It is recognized by the Council on Higher Education Accreditation (CHEA) and holds a membership in the Association of Specialized Professional Accreditors (ASPA).
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American Pregnancy Association (APA)
The Journal of the American Podiatric Medical Association, the official peer-reviewed journal of the APMA, is the oldest and most frequently cited journal in the profession of foot and ankle medicine. Founded in 1907, the Journal appears six times per year and publishes research studies, case reports, literature reviews, special communications, clinical correspondence, letters to the editor, book reviews, and various other submissions. It also regularly carries reports and announcements from the association. See also: American Academy of Orthopedic Surgeons
(AAOS); American College of Sports Medicine (ACSM); Orthopedics; Podiatrist.
Bibliography. Ian J. Alexander, The Foot: Examination
and Diagnosis (Churchill Livingstone, 1997); American Association of Colleges of Podiatric Medicine, www.aacpm .org (cited August 2006); American College of Foot and Ankle Surgeons, www.acfas.org (cited August 2006); American Podiatric Medical Association (APMA), www.apma.org (cited August 2006); Lisabeth M. Holloway, A Fast Pace Forward: Chronicles of American Podiatry (Pennsylvania College of Podiatric Medicine, 1987); M. Lisa Weatherford, ed., Podiatry Sourcebook (Omnigraphics, 2001). Ben Wynne, Ph.D. Gainesville State College
American Pregnancy Association (APA) As an organization committed to promoting healthy pregnancies and to reproductive issues, the American Pregnancy Association pursues its goals through education, research, advocacy, and serving the public interest. APA is headquartered at 1424 Greenway Drive, Suite 440, Irving, Texas. Education efforts include a toll-free helpline (800-550-2296), and a wealth of information on pregnancy and reproduction provided at the APA’s Web site (www.americanpregnancy.org). In addition to a pregnancy calculator, online topics include birth control, fertility issues, fetal development, preparation for childbirth and parenting, healthcare for pregnant mothers, the birthing experience, prenatal testing, complications
of pregnancy, birth defects and disorders, multiple births, unplanned pregnancies, pregnancy loss, and postnatal care. Other sections offer information on adoption and women’s health in general. APA was founded in 1995 in response to the media attention that followed the decision of an infertile couple, Mike and Annie Shaeffer, to use two billboards in the city of Dallas to announce their desire to adopt. After the Dallas Morning News and the Associated Press covered the story, the national media became interested in the couple. As a result of the national coverage, the Shaeffers received more than 1,000 calls from individuals and couples who needed advice and information on pregnancy and reproduction. This led to the decision to establish America’s Pregnancy Helpline, which generated 212 referrals in its first year, and to begin broadcasting public service announcements. Over the next nine years, the helpline provided information and referrals to 147,000 women and families from 75 countries and the United States. In 2003 the helpline was expanded into the APA. The constituency of the APA is vast. According to the organization, some 16,438 women become pregnant every day in the United States (6 million a year). Even though 64 percent of American women use birth control, 8,219 unplanned pregnancies occur each day. Each year, 468,988 babies are born to teenage mothers. Around 260,000 infants are stillborn each year, and many pregnancies are terminated either through abortions (1,200,000 per year) or miscarriages (600,000 a year). Every year, some 875,000 women experience some kind of pregnancy complication, partially because 1,172 of the mothers who become pregnant each day are uninsured and because 458,952 pregnant women each year fail to receive adequate prenatal care. Every day across the country, some 11,018 infants are born, but approximately 27,864 infants a year die before they reach their first birthdays. More than 154,000 American infants are born with some kind of birth defect. Each day, approximately 5,479 couples experience fertility issues, and APA is concerned with providing information and support for them. About a third of infertility problems are related to female inability to conceive, another third to male fertility problems, and the remaining third derives from couple infertility issues or unknown causes. After a year of failing to conceive,
American Psychological Association (APA)
APA encourages couples to seek medical help and undergo testing. Fertility therapies vary from hormones to surgeries to in vitro fertilization. In the case of female infertility, some couples turn to surrogacy, deciding to have the male’s sperm implanted in a surrogate mother. For parents who choose adoption over fertility treatments, APA provides explanations of the adoption process, discusses the advantages of closed versus open adoptions, and offers referrals to adoption agencies and attorneys who deal with adoptions. In addition to conducting extensive research on pregnancy and reproduction, APA is a strong advocate at the national, state, and local levels for women and families, promoting health issues of relevant concern. Advocacy efforts have often been directed at pressuring insurance companies, corporations, and businesses to expand coverage for pregnancies, infertility, and adoption. Insurance companies are also the target of efforts to abolish the practice of classifying pregnancy as a preexisting condition, which allows carriers to deny coverage to workers and dependents of workers who change jobs over the course of a pregnancy. At the national and state level, advocates lobby to promote and protect reproductive, pregnancy, and sexual health issues. Winning the right for gynecologists and obstetricians to practice without charging exorbitant insurance premiums to protect them from unnecessary lawsuits is also of major concern. See also: American College of Obstetricians and Gyne-
cologists (ACOG); American Fertility Association (AFA); Infertility; Reproductive Health (General). Bibliography. Heather E. Aldred, ed., Pregnancy and
Birth Sourcebook (Omnigraphics, 1997); American Pregnancy Association, www.americanpregnancy.org (cited January 2007); Murray Enkin, et al., A Guide to Effective Care in Pregnancy and Childbirth (Oxford University Press, 2000); Clare Hanson, A Cultural History of Pregnancy: Pregnancy, Medicine, And Culture, 1752–2000 (Palgrave, 2004); M. Sara Rosenthal, The Pregnancy Sourcebook: Everything You Need to Know (e-book) (Chicago NTC Contemporary, 1999); Helen M. Sterk, et al., Who’s Having This Baby? Perspectives on Birthing (Michigan State University Press, 2002). Elizabeth R. Purdy, Ph.D. Independent Scholar
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American Psychological Association (APA) With 150,000 members, the American Psychological Association is the largest association of psychologists in the world. APA considers psychologists to be individuals who have obtained doctoral degrees from accredited colleges and universities. Individuals whose terminal degrees are at the master’s level may be known by a variety of titles, such as counselors and clinicians. The term psychology, according to the APA definition, is “the study of the mind and behavior.” Psychologists may choose to concentrate on specific subfields, such as children’s development or geriatrics. APA headquarters is located at 750 First Street, NE, Washington, D.C. Additional information on the organization is available by telephone (800-374-2721). From the APA’s Web site (www.apa.org), users may access information on APA as well as read articles on a variety of topics related to psychology, including addictions, aging, Alzheimer’s disease, anger, anxiety, bullying, depression, kids and the media, race, sexuality, shyness, stress, violence, and women and men. APA’s mission is to advance the interests of psychology both as a science and as a profession while promoting the interests of public health and welfare. These goals are accomplished by encouraging the development of all branches of psychology; supporting ongoing and innovative research; demanding that all members as well as the APA achieve high standards of ethics, conduct, education, and achievement; expanding knowledge and understanding through meetings and seminars and through relationships and ongoing dialogue among members; distributing reports on relevant issues; generating scientific papers; and publishing materials that advance the field of psychology and the public interest. APA is governed by a Board of Directors, a Council of Representatives, and various committees. The system is set up according to well-defined checks and balances. APA was founded in December 1893 in Philadelphia, Pennsylvania. During World War II, APA began working closely with the American Association for Applied Psychologists. In 1945 the two groups united as APA with a new mission that encompassed both academic and applied psychology. Seventeen divisions were also established, and the Council
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American Public Health Association (APHA)
of Representatives replaced the Board of Directors as the policy-making body. Advocacy is an important element in achieving organizational goals. Through the Public Interest Public Policy Office, APA maintains relationships with key legislators and government officials, lobbies officials, and helps to formulate policies on relevant issues. Areas of concern to APA include children; youth; families; women; HIV/AIDS; disabilities; lesbian/gay/transgender, and bisexual issues; ethnic minorities; the elderly; crime and violence; and the media and telecommunication. Current hot-topic issues focus on reacting to the Centers for Disease Control and Prevention’s release of a draft version of The Health Protection Research Guide 2006–15 and to a draft version of the National Institutes of Health’s reauthorization bill. APA is also involved in a petition campaign to protect the integrity of scientific research. Organizational publications include Ethics and Behavior, Spin, and Psychological Science Agenda. Current science policy issues include combating terrorism, buprenorphine treatment of substance abuse, medical errors and patient safety, child health and human development, and mental health research. Educational policy efforts have been directed toward garnering additional funding for education and training, encouraging work with underserved populations, and supporting National Health Service Corps and Community Health Centers initiatives. See also: National Mental Health Association (NMHA);
Psychologist; Psychology.
Bibliography. American Psychological Association,
www.apa.org (cited January 2007); John Z. Arlsdale, ed., Advances in Social Psychology Research (Nova Science, 2006); Robert M. Donaldson, Jr., et al., eds., The Yale Guide to Careers in Medicine and the Health Professions: Pathways to Medicine in the 21st Century (Yale University Press, 2003); Donald A. Hantula, ed., Advances in Social and Organizational Psychology (Lawrence Erlbaum, 2006); Janice W. Lee, ed., Gender Roles (Nova Biomedical Books, 2005); Earl Wysong, High Risks and High Stakes: Health Professionals, Politics, and Policy (Greenwood, 1992); Lorri A. Zipperer, ed., The Health Care Almanac: A Resource Guide to the Medical Field (American Medical Association, 1995). Elizabeth R. Purdy, Ph.D. Independent Scholar
American Public Health Association (APHA) The mission of the American Public Health Association (APHA) is to improve public health and achieve an equal health status for all people. APHA pursues these goals by promoting public health as a science and as a profession, advocating for improved health for persons around the globe, emphasizing prevention as a key to health, and enhancing protections for the environment that impact on public health. National headquarters is located at 800 I Street, NW, Washington, D.C. Information on APHA is available by telephone (202-777-2742) or via their Web site (www.apha.org). Founded in the late 19th century, APHA is now the largest public health organization in the world, with a membership of more than 50,000 people engaged in over 50 subareas of public health. Members of the APHA team include advocates, chiropractors, consultants, dentists, dietitians, educators, environmental engineers, epidemiologists, administrators, lab technicians, nurses, optometrists, physicians, podiatrists, researchers, scientists, statisticians, students, and managed care providers. These individuals work together to promote good health, prevent disease and injury, and avert premature death. Over time, the APHA team has been instrumental in helping to increase life expectancy in the United States from 45 years to 77.85 years (75.02 for males and 80.82 for females). From the outset, APHA has been involved in preventing disease and promoting good health practices and policies. Goals are focused on professional exchange, study, and action. Particular areas of interest involve personal and environmental health; health funding; pollution control; chronic and infectious disease prevention, control, and treatment; creating a smoke-free society; and educating professionals in the field of public health. Professional development is pursued through academic and practical training, publications, annual meetings, and advocacy. APHA maintains close relationships with legislators and administrative officials at both the national and state levels in order to have a greater impact on public health policy issues. Priority advocacy issues include public health and managed
care, children’s health, the environment, and the public health infrastructure. APHA publications include the American Journal of Public Health and The Nation’s Health, a monthly newsletter. APHA also publishes a number of books and periodicals on the diverse areas encompassed by the public health profession; these books serve as resource materials around the world. Some 30 discipline-based groups are represented at APHA’s annual meeting, which is attended by more than 14,000 professionals. APHA has approved continuing education and development programs for certified health educators, physicians, laboratory professionals, registered dietitians, chiropractors, and dental professionals. The Scientific and Professional Affairs unit of APHA is charged with practice oversight, program development, grant making, and the dissemination of relevant public health information Current APHA projects and areas of public interest include education and treatment of HIV/AIDS, Action for Healthy Kids, Toolkit for the Intervention of Overweight Children and Adolescents, the Obesity Epidemic in U.S. Minority Communities, AskMe3 (a health literacy program), March of Dimes, the Maternal Child Health Information Resource Center, Public Health and the Pursuit of Peace, and Healthy Diet Counseling. APHA works with the Centers for Disease Control and Prevention on the Public Health Innovations Project, which provides the public health community with tools needed for impacting community health and responding to disasters such as Hurricane Katrina and to outbreaks of influenza, mad cow disease, and the West Nile virus. See also: Association of Schools of Public Health (ASPH);
Centers for Disease Control and Prevention (CDC); European Public Health Association (EUPHA); National Center for Public Health Informatics (NCPHI). Bibliography. American Public Health Association,
www.apha.org (cited January 2007); Philip J. Hilts, Rx for Survival: Why We Must Rise to the Global Challenge (Penguin, 2005); Klaus Hurrelmann and Ulrich Laaser, eds., International Handbook of Public Health (Greenwood, 1996); Michael R. Reich, ed., Public-Private Partnerships for Public Health (Harvard Center for Population and Development Studies, 2002); Earl Wysong, High Risks and High Stakes: Health Professionals, Politics, and Policy (Greenwood,
American Red Cross
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1992); Lorri A. Zipperer, ed., The Health Care Almanac: A Resource Guide to the Medical Field (American Medical Association, 1995). Elizabeth R. Purdy, Ph.D. Independent Scholar
American Red Cross After observing the success of the International Red Cross in Europe, social reformer and nursing pioneer Clara Barton (1821–1912) founded the American Red Cross on May 21, 1881, to provide assistance for Americans suffering from disasters or serving on the battlefield. As a representative of the organization, Barton, who served as president until 1904, provided assistance during the Johnstown, Pennsylvania, flood of 1889 and during the Galveston, Texas, tidal wave disaster of 1900. During the Spanish-American War (1898) in Cuba, Barton brought order to chaos, offering food and medicine that the army had been too disorganized to provide. Synonymous with compassionate service, the Red Cross responds to more than 70,000 disasters each year, including fires, hurricanes, floods, earthquakes, tornadoes, hazardous materials spills, transportation accidents, and explosions. In the field, Red Cross workers provide shelter, food, physical and mental health services, financial assistance, transportation, medications, and tools. The Red Cross also serves as a liaison with government agencies and insurance agencies; and when all other avenues are exhausted, the Red Cross provides long-term assistance. In addition to providing disaster relief, the American Red Cross oversees the collection, testing, storage, and distribution of the nation’s blood supply. Because a blood transfusion is needed every two seconds in the United States, the work of the Red Cross in this area is essential to the health of Americans. Other services offered by the organization include providing community assistance for the economically disadvantaged, supporting and comforting members of the military and their families, and offering health and safety education, such as cardiopulmonary resuscitation (CPR), first aid, and lifeguarding classes. At the international level, the American Red
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American Red Cross
Cross provides disaster relief and establishes development programs. Although the American Red Cross has some 35,000 paid employees who work in 800 locally supported chapters, the heart of the organization is the nearly 1 million volunteers who provide expert training, compassion, and labor. Required to respond within two hours to any emergency, Red Cross workers go across the country, as was the case after terrorist attacks on September 11, 2001, and when Hurricane Katrina devastated America’s Gulf Coast in late August 2005. When evacuees were spread across the country after New Orleans flooded in the wake of Katrina, the Red Cross set up a special Web site to facilitate communication among family members who had lost contact with one another. In addition to offering financial and health support, the Red Cross provided psychologists and counselors to furnish emotional support to Katrina victims. Through affiliation with the International Red Cross and the Red Crescent organization, the American Red Cross extends help wherever it is needed. For instance, in 2005, workers traveled to Pakistan and northern India after an earthquake devastated the area at a cost of 74,000 lives. Relief efforts continued as the organization sought to assist the 3.5 million people who were left homeless in the wake of the earthquake. Efforts to aid Indonesian children who have been devastated by two tsunamis, earthquakes, volcanic eruptions, and a measles epidemic are also ongoing. Other international projects include immunization programs in Angola, Kenya, Sudan, and Bangladesh and a housing program in Sri Lanka. Recognizing that each day, 850 million people in the world go hungry and 20,000 individuals die from starvation, the American Red Cross celebrates World Food Day each October to draw the attention of the American people to world hunger. Supported entirely by donations and proceeds from Red Cross products, approximately 91 percent of the organizational budget is earmarked for humanitarian efforts. Red Cross products range from first aid, shortwave radios, and automobile emergency kits to jewelry, clothing, and book bags. Corporate donors are integral to the work of the Red Cross. For instance, proceeds from the sale of Clorox bleach products are used to fund the Dedicated to a Healthier World project. The national headquar-
ters of the American Red Cross is located at 2025 E Street, NW, Washington, D.C. Further information and assistance is available by telephone (800-REDCROSS) or on the internet (www.redcross.org). As part of an agreement with Language Line, telephone conversations are instantly interpreted into other languages, and information at the Web site is available in English or Spanish. The American Red Cross depends on practical support from a wide range of individuals and organizations. For instance, Red Cross technical experts have led the way in meeting health crises, such as the HIV/AIDS epidemic that has ravaged entire populations in parts of Africa and Asia. Celebrity endorsement has traditionally served to draw attention to the work of the Red Cross. Celebrity supporters in the World War I era included Mary Pickford and Douglas Fairbanks. In 2006, 44 celebrities announced their support for the American Red Cross, including Julianne Moore, Pierce Brosnan, Rascal Flats, Dakota Fanning, Cuba Gooding, Jr., Jamie Lee Curtis, and Jimmy Smits. Collaborations with other health organizations also greatly strengthen the ability of the Red Cross to promote safety and health. Governance of the American Red Cross has traditionally been provided by a Board of Governors. In 2006 the governing process was overhauled, and board membership was reduced by half. The Cabinet Council, composed of seven members transferred from the Board of Governors, was created to serve as an advisory board. Partially in response to complaints of fraud among Red Cross workers involved in Katrina relief, whistle-blowing measures were expanded. In April 2006 the American Red Cross also announced plans to strengthen its infrastructure to provide for speedy assistance to a million families within a 10-day period and to 2 million people over a longer period. The new initiatives also led to the creation of a nationwide database to track shelters and evacuees during disasters. The organization also committed Red Cross workers in 13 high-risk areas to working closely with state emergency personnel to provide disaster assistance and relief. As with any other public health service organization, advocacy is an essential ingredient for the American Red Cross in delivering on its mission to serve and protect the public. Therefore, it works with legislators and administrators at all levels of government
American Social Health Association (ASHA)
to pursue the public interest. The advocacy function involves developing policy statements, testifying at hearings, generating position statements, and serving on external task forces and committees. See also: International Committee of the Red Cross
(ICRC); International Federation of Red Cross and Red Crescent Societies (IFRC); International Red Cross and Red Crescent Movement (RCRC). Bibliography. American Red Cross, www.redcross.org
(cited January 2007); David H. Burton, Clara Barton: In the Service of Humanity (Greenwood, 1995); Foster Rhea Dulles, The American Red Cross: A History (Greenwood, 1971); John F. Hutchinson, Champions of Charity: War and the Rise of the Red Cross (Westview, 1996); Ross Ishbel, Angel of the Battlefield: The Life of Clara Barton (Harper, 1956); Michele Turk, Blood, Sweat, and Tears: An Oral History of the Red Cross (E Street Press, 2006); Robert W. Winston, The Red Cross and the War (Winston, 1918). Elizabeth R. Purdy, Ph.D. Independent Scholar
American Social Health Association (ASHA) Originally called the American Social Hygiene Association, the American Social Health Association (ASHA) was founded in 1914 as part of a reform movement and moral crusade focused on stopping the spread of venereal disease. Problems associated with venereal disease were of particular concern as millions of young American males mobilized for World War I. Because of the fear that these soldiers would return from overseas infected, thousands of posters, pamphlets, books and handbills were distributed to soldiers and the general public with the message that remaining diseasefree was an important element in winning the war and preserving the “American way” in the United States. At a time when venereal diseases such as gonorrhea and syphilis were taboo subjects despite their devastating consequences, ASHA spoke out. In the 21st century, ASHA remains dedicated to improving the health of individuals, families, and
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communities with a focus on preventing sexually transmitted diseases and infections. As a nonprofit organization, it is funded primarily by individual donors, foundations, corporations, government agencies and other groups interested in the association’s mission. The group’s goals include educating the public to understand, prevent, and destigmatize sexually transmitted diseases; empowering patients through education and support to understand and manage their health needs; and advocating strong healthcare policies to provide adequate resources for fighting diseases. The association is recognized by patients, providers, policy makers, government officials, and the general public for developing and delivering accurate, medically based information about sexually transmitted diseases. Across the United States public clinics and health facilities at colleges and universities make use of the ASHA’s educational books and pamphlets by distributing them to clients, patients and students. Community groups also depend on the association to help disseminate information related to the consequences of high-risk behavior and to the transmission, prevention, testing and treatment of disease. The ASHA created the Herpes Resource Center (HRC) in 1979 and the National HPV and Cervical Cancer Prevention Resource Center in 2000 to aid education, increase public awareness, and lend support to those concerned with or affected by sexually transmitted diseases. These resource centers publish the latest information on sexually transmitted diseases, serve as a referral center to match individuals with state or local organizations that might offer them assistance, advocate for responsible national policies related to prevention and treatment, and promote public awareness by working with media outlets. See also: Centers for Disease Control and Prevention
(CDC); National Center for HIV, STD, and TB Prevention (NCHSTP); Sexually Transmitted Diseases.
Bibliography. American Social Health Association, Sex-
ually Transmitted Diseases in America: How Many Cases and at What Cost? (Kaiser Family Foundation, 1998); American Social Health Association, www.ashastd.org (cited August 2006); Ruth Clifford Engs, Clean Living Movements: American Cycles of Health Reform (Praeger, 2001); U.S. Department of Health and Human Services, Centers
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American Society for Reproductive Medicine (ASRM)
for Disease Control and Prevention, “Sexually Transmitted Diseases,” www.cdc.gov/std (cited August 2006). Ben Wynne, Ph.D. Gainesville State College
American Society for Reproductive Medicine (ASRM) Founded in 1944 in Chicago, Illinois, as the American Fertility Society, the American Society for Reproductive Medicine (ASRM) was originally composed of a small group of fertility experts who were the first physicians to perform many of the standard procedures used by modern fertility specialists, including donor insemination and in vitro fertilization. Through the years, ASRM members have developed new approaches to contraception and ovulation induction and have helped promote key legislation related to reproductive rights. The Society’s stated mission is the promotion and advancement of the art, science, and practice of reproductive medicine through the pursuit of excellence in education and research and through advocacy on behalf of patients, physicians, and affiliated healthcare providers. The ASRM is committed to facilitating and promoting educational activities for the general public and continuing medical education activities for professionals who are engaged in the practice of and research in reproductive medicine. Today, all 50 states are represented in the ASRM’s membership, as are more than 100 foreign countries. The society is multidisciplinary, with members including obstetrician/gynecologists, urologists, reproductive endocrinologists, embryologists, mental health professionals, internists, nurses, practice administrators, laboratory technicians, pediatricians, research scientists, and veterinarians. The ASRM has an administrative office in Birmingham, Alabama, and a public affairs office in Washington, D.C. Policy is set by an elected Board of Directors and implemented by an executive director, an associate executive director, and an accomplished staff. The society is also committed to ensuring that the quality of its continuing medical education program
meets the Accreditation Council for Continuing Medical Education (ACCME) essentials. This goal is met through scientific presentations, seminars, workshops, and postgraduate courses at the organization’s annual meeting, free-standing postgraduate courses, the monthly continuing medical education initiatives, electronic media, internet CME activities, periodic lectures and workshops, and by other publications from the society. To ensure the ongoing effectiveness of its programs, the organization routinely surveys its membership and solicits various forms of feedback. The ASRM sponsors a number of publications, including Fertility and Sterility, an international journal for obstetricians, gynecologists, reproductive endocrinologists, urologists, basic scientists, and other health professionals who treat and investigate problems of infertility and human reproductive disorders as well as issues related to women’s health. It is a peer-reviewed journal that includes original scientific articles in clinical and laboratory research related to reproductive endocrinology, developmental biology, urology, physiology, immunology, genetics, contraception, psychosocial issues, ethics, and menopause. The society also publishes two newsletters, ASRM News and Menopausal Medicine, as well as a wide range of booklets and fact sheets for healthcare professionals and the general public. See also: American College of Obstetricians and Gyne-
cologists (ACOG); American Fertility Association (AFA); Infertility; Reproductive Health (General).
Bibliography. American Society for Reproductive Med-
icine, www.asrm.org (cited August 2006); Bruce R. Carr, Richard E. Blackwell, and Ricardo Azziz, Essential Reproductive Medicine (McGraw-Hill Professional, 2004); Society for Assisted Reproductive Technology, www.sart.org (cited August 2006). Ben Wynne, Ph.D. Gainesville State College
American Society of Clinical Oncology (ASCO) Founded in 1964, the American Society of Clinical Oncology (ASCO) is the world’s leading professional
American Society of Clinical Oncology (ASCO)
organization representing physicians who treat individuals with cancer. The society’s membership sets high standards for patient care worldwide and plays a leading role in advancing clinical research aimed at improving the prevention, diagnosis, and treatment of cancer. Members of the ASCO also advocate policies that provide universal access to high-quality care for all patients with cancer and support increased funding for clinical and translational research. The ASCO has more than 23,000 members worldwide, including clinical oncologists from all oncology disciplines and subspecialties (medical oncology, therapeutic radiology, surgical oncology, pediatric oncology, gynecologic oncology, urologic oncology, and hematology); physicians and healthcare professionals participating in approved oncology training programs; oncology nurses; and other healthcare practitioners with a predominant interest in oncology. International members representing more than 100 nations make up a quarter of the society’s total membership. ASCO is governed by an elected board of 19 members including a president, president elect, secretarytreasurer, immediate past president, executive vice president, and 14 directors. The society conducts the majority of its business through more than 20 committees made up of ASCO members who volunteer their time to the society’s programs. Leaders of patient advocacy groups are also active in ASCO committees. ASCO has access to a wide range of legislative and regulatory resources that allow oncologists around the country to remain current on key issues that have substantial impact on the cancer community. The society’s advocacy programs function to educate Congress, state legislatures, the media, and the general public about the effects of legislation on the ability of oncologists to provide first-rate cancer care. The ASCO Foundation, a 501(c)(3) charitable organization, supports educational programs of the highest quality in cancer care and prevention; facilitates the dissemination of information about cancer and cancer treatment to patients and their families; and, through its grants program, supports, encourages, and recognizes excellence in clinical research in the field of oncology. Through partnerships with private businesses, foundations, and individuals, the ASCO Foundation obtains vital support for programs that inspire ingenuity in research, invigorate a new generation of oncologists, bring new treatments to great
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The American Society of Clinical Oncology’s 23,000 members include cancer specialists working in more than 100 nations.
numbers of practitioners and their patients, and advocate for policy that enriches the lives of people living with cancer and their families. ASCO sponsors several publications, including the Journal of Clinical Oncology, the organization’s official, peer-reviewed journal that offers its readers access to the latest research in the field of cancer treatment. The Journal of Oncology Practice (JOP) provides oncologists and other oncology professionals with information and other resources in an ongoing effort to enhance individual or group practices and promote high standards for quality of patient care. The JOP has been recognized as the primary resource for oncologists making daily decisions about clinical and administrative management. In addition to journals, the ASCO produces a variety of printed matter related to topics that are important to oncologists and to the practice of oncology. See also: American Association for Cancer Research
(AACR); American Cancer Society (ACS); Association for International Cancer Research (AICR); International Agency for Research on Cancer (IARC); National Cancer Institute (NCI); Oncologist; Oncology. Bibliography. Martin Abeloff, et al., Clinical Oncology
(Churchill Livingstone, 2004); American Society of Clinical Oncology, www.asco.org (cited August 2006); Raymond E. Lenhard, Jr., Robert T. Osteen, and Ted Gansler,
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eds., Clinical Oncology (Blackwell, 2000); Philip Rubin, Clinical Oncology: A Multi-Disciplinary Approach for Physicians & Students (Saunders, 2001). Ben Wynne, Ph.D. Gainesville State College
American Society of Clinical Pathology (ASCP) The American Society of Clinical Pathology (ASCP) was founded in 1922 in St. Louis, Missouri, with 145 charter members. At the time the society’s stated goal was “to achieve greater scientific proficiency in clinical pathology, and to maintain the status of clinical pathology on an equal plane with other specialists.” As set forth in the group’s constitution, the primary objectives of the ASCP are to promote the practice of scientific medicine by a wider application of clinical laboratory methods to the diagnosis of disease, stimulate original research in all branches of clinical laboratory work, maintain uniform standards for the performance of various laboratory examinations, elevate the scientific and professional status of pathologists, and encourage a closer cooperation between the practitioner and the clinical pathologist. The ASCP is governed by a Board of Directors that includes some of America’s leading professionals in the field of clinical pathology. The board sets policy and develops long range strategies, while separate commissions within ASCP develop and monitor overall strategy related to specific areas such as membership, education, publications, assessment, and public policy. A large part of the mission of ASCP deals with education, and the society offers a number of scholarship programs to encourage young people in the laboratory sciences. Through a state-of-the-art database and placement service, the organization also aids recent medical school graduates as they enter the job market. For experienced healthcare professionals ASCP offers a variety of continuing medical education options, including national and regional conferences, online courses and self-study programs. The society also keeps its members informed about state and national legislation related to the laboratory sciences and maintains an advocacy cen-
ter through which members can express their opinions and concerns to elected officials. The center allows ASCP members to track the voting records of legislators and congressmen and publishes schedules of upcoming congressional hearings or other important meetings. ASCP sponsors several publications, including the American Journal of Clinical Pathology, a monthly peer-reviewed journal for those interested in pathology and laboratory medicine, and Pathology Patterns Reviews, which is published twice a year and includes review articles on topics relevant to diagnosis, technology and practice environment. LABMEDICINE is a monthly periodical dedicated to providing the entire laboratory community with continuing education and career development and covering new technologies as they become applicable to the medical laboratory. See also: Pathologist; Pathology. Bibliography. American Society of Clinical Pathologists
(ASCP), Handbook of Clinical Pathology (ASCP, 1999); ASCP, www.ascp.org (cited September 2006); American Society for Clinical Laboratory Science, www.ascls.org (cited September 2006); College of American Pathologists, www.cap.org (cited September 2006); Michael Laposata, Laboratory Medicine: Clinical Pathology in the Practice of Medicine (ASCP, 2002); Daniel D. Mais, Quick Compendium of Clinical Pathology (ASCP Press, 2005). Ben Wynne, Ph.D. Gainesville State College
American Society of Human Genetics (ASHG) Founded in 1948, the American Society of Human Genetics (ASHG) is the primary professional membership organization for human geneticists in the Americas. The society’s more than 8,000 members include researchers, academicians, clinicians, laboratory practice professionals, genetic counselors, and nurses along with others who have a special interest in the field of human genetics. The ASHG’s goals focus on providing venues to bring investigators opportunities
to share their research findings in the many areas of endeavors in human genetics; informing health professionals, legislators, health policy makers, and the general public about all aspects of human genetics; and facilitating interactions between geneticists and other communities, including policy makers, industry, educators, and patient and public advocacy groups. The ASHG is governed by an 18-member board of directors that includes leaders in the field of human genetics. The board sets policy and develops long range strategies for the society. While there are different levels of membership in the society, any person residing in the Americas who is interested in research in human genetics or in issues pertaining to human genetics is eligible for membership in the society upon election by the Board of Directors. The ASHG’s administrative offices are located in Bethesda, Maryland, and the organization sponsors a number of regional gatherings throughout the year as well as a major annual meeting. A large part of the mission of the ASHG deals with education, and the society promotes scholarship and encourages students and young practitioners who devote their time and energy to genetics and genetic research. The society also has a long history of providing educational opportunities for students and science and biology teachers at the ASHG annual scientific meeting, at national teacher conferences, and through individual efforts of hundreds of ASHG members as part of the Mentor Network. More than 1,200 genetic scientists, counselors, clinicians, and advocates are members of the Mentor Network and routinely work with teachers at various levels. The ASHG, along with the Association of Professors of Human and Medical Genetics, have developed a Medical School Core Curriculum to provide guidance to deans and curriculum committees regarding medical genetics knowledge, skills, and behaviors that all medical students will need during their careers as physicians. For experienced healthcare professionals the ASHG offers a variety of continuing medical education options including national and regional conferences, online courses, and other programs. The society sponsors a number of publications, including the American Journal of Human Genetics, a highly regarded peer-reviewed monthly journal, and a variety of pamphlets and brochures related to the field of genetics. The ASHG Evolution Series is a regu-
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larly updated collection of essays by society members written to demonstrate the historical, conceptual, and practical connections between human genetics and evolution. The goal of the series is to help those with an interest in genetics and genetic theory see more clearly the centrality of evolution theory to biology and its importance with regard to science education. See also: Genetics; National Human Genome Research
Institute (NHGRI).
Bibliography. American Society of Human Genetics,
www.ashg.org (cited September 2006); Genetics Education Partnership, genetics-education-partnership.mbt.washington.edu (cited September, 2006); Ricki Lewis, Human Genetics (McGraw-Hill, 2005); March of Dimes, “Genetics and Your Practice,” www.marchofdimes.com/gyponline (cited September 2006); National Society of Genetic Counselors, www.nsgc.org (cited September 2006). Ben Wynne, Ph.D. Gainesville State College
American Society on Aging (ASA) Founded in 1954 as a not-for-profit organization, the American Society on Aging (ASA) is committed to improving the health and quality of life for older Americans and their families by providing physical, emotional, social, economic, and spiritual support. The 6,000 members of ASA encompass a wide range of disciplines, including physicians, educators, administrators, decision makers, the business community, researchers, and students. ASA, which is governed by a Board of Directors, is headquartered at 833 Market Street, Suite 511, San Francisco, California. Information on the organization is available by telephone (800-537-9728) or from the Web site (www. asaging.org). ASA’s online resources include sections on the aging and assistive workforces, alcohol and drugs, arts, cultural and ethnic diversity, DriveWell, elder abuse, injury prevention, lesbian and gay aging, lifelong learning, and mental health. ASA encourages the elderly to improve the quality of their own lives by engaging in lifelong learning and participating in civic
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affairs and spirituality programs. Special support is available for the elderly who need long-term care. Organizational objectives include expanding the ability of ASA members to serve their constituency through research, conferences, publications, and resource provisions; enhancing communication and engaging in collaborative and advocacy efforts to positively affect policy; proposing solutions to existing problems; and exploring new mechanisms that increase the ability of ASA to accomplish its mission. ASA is also committed to strengthening advocacy efforts to increase funding for age-related issues and reaching the broadest spectrum of elderly Americans. Educational opportunities encompass conferences, courses, and professional training for those who work with the elderly. Each year, the ASA-NCOA (National Council on Aging) joint conference brings together researchers from around the country, providing them with a forum for discussing age-related issues and presenting the results of numerous research projects. In the fall, ASA conducts the Autumn Series on Aging, which is a series of regional training events for professionals who work with the elderly, their families, and caregivers. ASA also offers inexpensive or free online seminars that serve as convenient training tools and provide continuing education credits. Seminar topics include “Comprehensive Geriatric Assessment,” “National Center for Health Statistics Trends in Health and Aging Series,” “PARC Disaster Preparedness Series,” “Planning and Coordinating Care for People with Alzheimer’s,” “the Legal and Ethical Issues of Aging,” and “What about Us? How Today’s Uninsured Baby Boomer Can Save on Prescription Drug Costs.” Additionally, ASA sponsors a number of continuing education and staff development courses, such as those offered for care managers, counselors, nurses, nursing home administrators, social workers, assisted living facilities administrators, case managers, certified health education specialists, recreation therapists, and drug and alcohol counselors. ASA publications also serve as resource and communication tools. Information on aging issues is available through Aging Today, a bimonthly publication. Generations provides scholars with a forum for geriatric research. Recent article topics in Generations include “Ageism and Sexism in the Workplace,” “Cosmetic Surgery and Cosmetics: Redefining the
Appearance of Age,” and “Old-Age Policies, Politics, and Ageism.” ASA Connection provides the online community with valuable resources on aging, and Age Beat serves as a resource on aging for journalists. See also: American Geriatrics Society (AGS); Geriatrics;
National Institute on Aging (NIA).
Bibliography. American Society on Aging, www.asag-
ing.org (cited January 2007); Patricia M. Burbank, ed., Vulnerable Older Adults: Health Care Needs and Interventions (Springer, 2006); Malcolm Johnson, The Cambridge Handbook of Age and Ageing (Cambridge University Press, 2005); Stephen Katz, ed., Cultural Aging: Life Course, Lifestyle, and Senior Worlds (Broadview, 2005); Richard A. Settersten, Invitation to the Life Course: Toward New Understandings of Later Life (Baywood, 2003); Lorri A. Zipperer, ed., The Health Care Almanac: A Resource Guide to the Medical Field (American Medical Association, 1995). Elizabeth R. Purdy, Ph.D. Independent Scholar
American Urological Association (AUA) Founded in 1902 and with a current membership of over 15,000 urologists and other healthcare professionals, the American Urological Association (AUA) is the largest professional association in the United States devoted to the advancement of urologic patient care. The association strives to enhance urological care nationwide by providing a wide range of services including research opportunities, publications, continuing medical education, national and regional meetings and the formulation of health policy. The AUA is governed by a board of directors that includes six officers, eight section representatives, and a number of nonvoting consultants. There are several levels of membership and all members are expected to adhere to the association’s Code of Ethics. The AUA’s annual meeting is the world’s largest meeting of urologic professionals, routinely drawing more than 10,000 urologists and other healthcare professionals, along with hundreds of exhibitors. While activities at the annual meeting are a source
of Continuing Medical Education (CME) credit, the association’s Office of Education also offers a variety of programs in all domains of urology disorders of the urinary system, adrenal glands, and the male genital tract in adults and children. These domains include urinary tract and male genital tract tumors, calculus disease, urinary diversions, benign prostatic hyperplasia, voiding dysfunction, incontinence, female urology, male and female sexual dysfunction, male infertility, genitourinary trauma, erectile dysfunction, pediatric urology, and office management. Information on basic science, clinical practice, practice management, socioeconomic considerations, and ethics are also included. As an advocacy group, the AUA develops its own annual legislative agenda and seeks to affect public policy related to the practice of urology. The association works to ensure that undue federal restrictions or limitations are not implemented that would hinder urologists’ ability to provide appropriate patient care. In addition, the AUA monitors the voting record of U.S. senators, congressmen, and state legislators and pays particular attention to the status of important issues such as government regulation, Medicare policies, and insurance reform. A primary function of the AUA deals with professional placement. Through a database that is constantly updated, the association offers employers and those seeking work in the field a valuable networking resource. The Journal of Urology is the official journal of the AUA. Published monthly, the journal is the most widely circulated publication in the field, offering upto-date, clinically relevant information to urologists and those in related fields. The journal presents investigative studies on critical areas of research and practice; survey articles providing short condensations of the most important urology literature worldwide; and practice-oriented reports on interesting clinical observations. Members of the AUA also receive access to a number of related publications, including Urologic Clinics of North America and the Atlas of Urologic Clinics in North America. Established in 2005 through a consolidation of the American Foundation of Urological Diseases (AFUD) and the AUA, the AUA Foundation is a partnership of physicians, researchers, healthcare professionals, caregivers, patients, and the general public established to promote research, patient and public education, and
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advocacy programs to improve the prevention, detection, treatment, and cure of urological disease. See also: Urological Surgeon; Urologist. Bibliography. American Urological Association, www
.auanet.org (cited September, 2006); American Urological Association Foundation, www.auafoundation.org (cited September, 2006); Lawrence W. Jones, Paul C. Peters, and Wendy Cowles Husser, The American Urological Association Centennial History (American Urological Association, 2002); UrologyHealth.org, www.urologyhealth.org (cited September, 2006). Ben Wynne, Ph.D. Gainesville State College
Ames, Bruce (1928– ) Bruce Ames is the American biochemist and geneticist who developed the Ames test for chemical mutagens. This test made him a hero to environmentalists in the 1970s, but Ames has since changed his position on man-made chemicals. During the late 1980s, and especially the 1990s, he came into conflict with those green militants who had hailed him as an asset to their cause. Ames has also devoted much of his career to cancer and aging, summarizing his research in over 500 publications. His authority is invoked in many medical fields and he is frequently quoted. Ames was born on December 16, 1928. He attended Cornell University from 1946 to 1950, graduating with a B.A. degree with a major in chemistry and a minor in biology. He then transferred to the biology department of the California Institute of Technology for his graduate study. After obtaining his Ph.D. in biochemistry, Ames moved to the National Institute of Arthritis and Metabolic Diseases (NIAMD) in 1953 as a public health service fellow. There, he started work on what would later become the Ames test. He conducted research to isolate the enzymes involved in the histidine pathway and to regulate genes in histidine biosynthesis using salmonella. Ames concluded that the histidine genes could be overexpressed if histidine availability reduced the
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growth rate. In 1962 Ames became a section head in the newly created laboratory of molecular biology at NIAMD, a position he held until 1967. In 1968 Ames was appointed Professor of Biochemistry and Molecular Biology at the University of California, Berkeley, a title he retained until 2000. Over his long career at Berkeley, Ames has chaired the Department of Biochemistry and Molecular Biology and acted as director of the National Institute of Environmental Health Sciences Center. He is currently a professor at the Berkeley Graduate School and a senior research scientist at the Children’s Hospital Oakland Research Institute. Ames owes much of his celebrity to the Ames test, which he refined in the 1970s. The test targets chemical mutagens, the agents that tend to increase the frequency or extent of genetic mutation. Ames’s version of the test is rapid and inexpensive and thus became more effective than the slower and more expensive epidemiological surveys and animal tests that were used before Ames devised his own test. It has been widely used to assess the mutagenic and carcinogenic risks of a large number of chemicals. The test allows scientists to discover whether the chemicals they are testing cause mutations in bacteria and could thus lead to cancer in humans. Thanks to Ames’s analysis, synthetic chemicals that were commonly used have been banned. Tris, the flame retardant used in children’s pajamas, was one of the most famous to be outlawed. The test and its results had a wide impact not only on the scientific community, but also on consumers’ choices. The development of the mutagenic test earned Ames important environmental awards such as the 1985 Tyler Prize. The relevance of the test for cancer research was recognized with the General Motors Cancer Research Foundation Prize in 1983. In addition, Ames was a member of the board of directors of the National Cancer Institute’s National Cancer Advisory Board from 1976 to 1982. Yet, Ames soon changed from an environmentalist icon into a target of green activists who claim he has put his services to work in favor of big corporations. After developing the mutagenic test, Ames collected more data that showed that natural chemicals can be as carcinogenic as those manufactured in a laboratory. Ames challenged common wisdom that portrayed man-made chemicals as more dangerous than natural ones:
People got in their head, well, if it’s man-made somehow it’s potentially dangerous, but if it’s natural, it isn’t. That doesn’t really fit with anything we know about toxicology. When we understand how animals are resistant to chemicals, the mechanisms are all independent of whether it’s natural or synthetic. And in fact, when you look at natural chemicals, half of those tested came out positive. Taking a cup of coffee as an example, Ames claims that there are more than 1,000 chemicals in it. Only 22 of these have been tested in animal cancer tests and 17 came out positive. So, he concludes, there are more carcinogens in a cup of coffee than people can get from a year’s exposure to pesticide residue. Chemicals of a carcinogenic nature have also been found in table pepper, mushrooms, peanut butter, tea, and bread. Ames has also denounced what he sees as environmentalists’ idyllic and romantic view of a past world that never really existed. He has challenged their views as antitechnology and antiscience. In 1990, he spoke against California’s Proposition 128, which, if passed, would have banned many pesticides. Ames has also criticized the ban on Alar, the plant growth regulator used primarily for apples that was prohibited in 1989. While it has been proved that Alar is a human carcinogen, the amount necessary to lead to cancer is extremely high. Although Ames does not completely rule out external factors in the development of cancer, he also strongly maintains that cancer is a degenerative disease of old age, in the same way as heart disease and cataracts. The fact that cancer rates are going up, Ames argues, is not the result of an increase in pollution, but of the fact that people live longer. These controversial views have caused heated debates within the scientific community and have also made Ames the subject of media interest. Because of this, Ames does not describe himself as a mere scientist but also as a popularizer who is trying to prevent cancer, rather than find a cure for it. As expected, Ames’s recipe for cancer prevention is as simple as it is provocative: “We should be eating more fruits and vegetables, so the main way to do that is to make them cheaper. Anything that makes fruits and vegetables more expensive may increase cancer.” Ames has criticized the overreliance on results from animal tests for the classification of carcinogens. Together with his researchers, he has established a
rating system for carcinogens similar to that in use for toxicity. The HERP (human exposure dose/rodent potency dose) index rates the degree of carcinogenesis of various chemicals based on the degree to which they have caused tumors in lab animals. The system, however, does not constitute a risk assessment but simply “an index of possible hazard.” Using this system, Ames came to the defense of Alar with a letter to Science arguing that the regulator caused a HERP level of 0.0017 percent in a six-ounce glass of apple juice, less than one-tenth that of either a single raw mushroom a day or a single peanut butter sandwich. Since the 1980s, Ames has also focused part of his research on aging and has shown the role of mitochondrial decay as a major contributor to aging and age-related degenerative diseases. He has carried out a series of experiments with the aim to reverse mitochondrial decay and has argued for a balanced intake of micronutrients in the population to prevent diseases, obesity, and malnutrition. The underlying factor in Ames’s research and the main source of his controversial character is his unabashed faith in the progress of science and technology. Ames has always described himself as optimistic about scientific research and about understanding cancer because there are millions of scientists throughout the world and rich nations need to continue to train and employ even more of them: “Life expectancy gets longer every year, and it’s going to get even longer, and it’s due to modern science and technology.” Ames was awarded the National Medal of Science in 1998 and is a member of the National Academy of Sciences. In spite of the controversies generated by his views on carcinogens and cancer, he has received many more prizes, including the Gold Medal Award of the American Institute of Chemists (1991), the Glenn Foundation Award of the Gerontological Society of America (1992), the Lovelace Institute’s Award for Excellence in Environmental Health Research (1995), the Linus Pauling Institute Prize for Health Research (2001), and the American Society for Microbiology Lifetime Achievement Award (2001). SEE ALSO: Cancer (General); Environmental Health; Envi-
ronmental Medicine; Gerontology.
Bibliography. Bruce Ames, www.bruceames.org (cited
January 2007); Virginia Postrel, “Of Mice and Men: Bruce
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Ames Interview” (November 1994), Reasononline, www .reason.com/news/show/32261 (cited January 2007). Luca Prono Independent Scholar
Amphetamines Amphetamines are central nervous system stimulants used medically to treat narcolepsy and attention deficit hyperactivity disorder (ADHD) that are also used illegally for recreational and performanceenhancing purposes. The term amphetamine refers to a class of drugs that includes amphetamine itself as well as the compounds dextroamphetamine (known commercially as Dexedrine®), methamphetamine, and MDMA. Methamphetamine in its various forms is commonly referred to as “speed,” “crystal meth,” “ice,” or “Tina,” while MDMA is frequently called “ecstasy,” “E,” or “X.” The illicit usage of all amphetamines has emerged in recent years as an important public health problem. In the United States, amphetamine, dextroamphetamine, and methamphetamine are classified as Drug Enforcement Administration (DEA) Schedule II drugs, which means that they have high potential for abuse, but can be made available in some medically necessary circumstances. MDMA is a Schedule I drug, implying that it also has a high potential for abuse, but has no currently accepted medical use. The sensation acquired after using any of the various amphetamines varies with the route of administration. In general, injection produces the most immediate effects. Inhalation by smoking produces a slower “high,” and the ingestion of pills provides the most delayed physiological changes. A “rush” of euphoria, an intensely pleasurable feeling attained soon after taking an amphetamine, is unique to injection and inhalation. Pharmacologically, amphetamines act by altering the transmission of central nervous system monoamine neurotransmitters, particularly norepinephrine, dopamine, and serotonin. The various amphetamines exert slightly different psychological changes, but in general, all act as potent stimulants, causing euphoria, enhancing alertness, improving attention, and increasing libido if taken in substantial doses. The abuse
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of amphetamines for recreational and performanceenhancing purposes is related to these effects. Physiologically, amphetamines cause increased heart rate, blood pressure, respiratory rate, and temperature, and, in excess, can lead to cardiac arrhythmia, hyperthermia, stomach cramping, nystagmus (rapid beating) of the eyes, tremors, stereotyped behaviors, anxiety, aggression, paranoia, and insomnia. Cardiac abnormalities and stroke occur rarely but are often fatal. “Coming down” off amphetamines causes the opposite effects, most notably fatigue, difficulty concentrating, and mood depression. Medical Usage Amphetamines, specifically dextroamphetamine (Dexedrine®), the purified isomer D-amphetamine, is indicated for the treatment of attention deficit hyperactivity disorder (ADHD) in children. At prescribed doses, it promotes impulse control and concentration while decreasing irritability. Adderall®, another ADHD medication, is a mixture of four amphetamine salts with similar beneficial effects. Prominent side effects among children taking amphetamines for ADHD include appetite suppression and insomnia, the latter of which can be prevented by taking the medication early in the day. Amphetamines are also standard in the treatment of narcolepsy, a disorder marked by frequent and often unexpected bouts of sleeping throughout the day. They are also occasionally used as “augmentation” agents in the treatment of depression when coupled with another antidepressant medication, such as a selective serotonin reuptake inhibitor (SSRI). In some countries, amphetamines are also approved for weight loss, but in the United States, this practice has been eliminated because of concerns about the safety of this practice. In general, the legitimate medical usage of amphetamines does not promote addiction among those to whom the medication has been prescribed. However, the increasing rate of prescription among children and adolescents has led to increased availability of amphetamines and concern about the practice of sharing these medications with others for illegitimate purposes. Production Methamphetamine is readily produced using common household products and over-the-counter medicines,
most notably ephedrine or pseudoephedrine. These compounds, once easily obtained in large quantities by purchasing cough and cold remedies, have been the subject of new legislation that restricts their purchase in many jurisdictions. Although synthesizing methamphetamine is a relatively simple process, most methods of production involve flammable chemicals, such as phosphine gas. Significant morbidity and mortality has resulted from fires caused by inexperienced chemists working with such compounds in clandestine laboratories. Much of the methamphetamine supply in the United States originates from large-scale producers located in Mexico and California. However, there has been a surge of small-scale laboratories in recent years, particularly in the Midwest, that have become an important source of the drug. These laboratories may elude detection by law enforcement officials because they are often mobile, existing, for example, in large vans or pickup trucks. These operations have been found in such diverse locations as mobile homes and motel rooms, exposing the general public to the danger associated with methamphetamine production. In 2006 the United Nations Office on Drugs and Crime reported that global production of amphetamine-like stimulants, including methamphetamine, was estimated at 480 metric tons. This was a higher value than calculated for the previous year but was less than that for 2000, showing an overall decrease since the beginning of the 21st century. Nations in north America, central America, western, central and eastern Europe, and east and southeast Asia represent the most important contributors to the global methamphetamine market. In particular, the largest producers of methamphetamine worldwide are located in Burma, China, and the Philippines. Societal and Global Impact The illicit use of amphetamines, most notably methamphetamine and MDMA, is of increasing concern in north America. In 2002, 1.4 percent of people aged 15–64 used methamphetamine or another amphetamine-type stimulant. Domestic methamphetamine production operations are an important public health issue not only because they provide a readily available supply of methamphetamine, but also because of laboratory fires.
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Worldwide, abuse of amphetamines rivals that of cannabis, the most commonly used drug internationally. The majority of amphetamine users live in Asia, with the highest prevalence of abuse found in Thailand. These high rates are concerning for several reasons. Because of their energy-increasing and inhibition-lowering effects, the use of amphetamines can be associated with risky sexual behaviors and transmission of sexually transmitted diseases including human immunodeficiency virus (HIV). Injection of the amphetamines intravenously also provides a route for direct inoculation of HIV and other blood-borne diseases, including the hepatitis B and C viruses. Additionally, injection using nonsterile needles places the user at risk for bacterial infections such as sepsis, bone and joint infection, pneumonia, and abscesses of the skin and other organs. Treatment for amphetamine abuse is reviewed elsewhere in this encyclopedia (see, e.g., Methamphetamine Abuse). Modalities targeting individual drug users as well as public health interventions are important in reducing the prevalence of illegal amphetamine use, and will ultimately prove invaluable in decreasing the harms associated with abuse. SEE ALSO: AIDS; Club Drugs; Drug Abuse; Methamphet-
amine Abuse.
In the United States, 185,000 amputations are performed each year, with the highest rates among people aged 65 and older.
BIBLIOGRAPHY. Drug and Alcohol Services Information
System, “Trends in Methamphetamine/Amphetamine Admissions to Treatment: 1993–2003,” www.oas.samhsa .gov (cited October 2006); Merck Manual Home Edition, “Amphetamines: Drug Use and Abuse,” www.merck.com/ mmhe (cited October 2006); National Institute on Drug Abuse, “NIDA Research Report—Methamphetamine Abuse and Addiction,” www.drugabuse.gov (cited October 2006). Scott E. Hadland Washington University School of Medicine
Amputees Amputation is an acquired condition that results in the loss of a limb, usually from injury, disease, or surgery. As a surgical measure, it is used to control pain
or a disease process in the affected limb, such as malignancy or gangrene. Arms, legs, hands, feet, fingers, and toes can all be amputated. Congenital (present at birth) limb deficiency occurs when an infant is born without part or all of a limb. The causes of congenital limb differences are frequently unknown, but might be attributed to drug use in the mother. About 1.2 million individuals in the United States are living with an amputation, with 185,000 performed each year. The birth prevalence of congenital limb deficiency is around 25 per 100,000 live births. The prevalence rate is highest among people aged 65 years and older, around 19.4 per 1,000. The number of total amputees worldwide is not currently known. The causes of amputation differ significantly in various countries. For example, countries with a recent history of warfare and civil unrest might have a higher incidence of amputations due to war itself or
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its technology (landmines, uncontrolled ordnance, etc.). In Islamic countries, amputation of the hands or feet is sometimes used as a form of punishment for criminals. In some cultures and religions, minor amputations or mutilations are considered a ritual accomplishment. The avulsion of some teeth (mainly incisives) is or was practiced by some cultures for ritual purposes (e.g., in the Iberomaurusian culture of Neolithic north Africa). Genital modification and mutilation may involve amputating tissue (as is the case with circumcision), although not necessarily as a result of injury or disease. In the United States, the most common causes of amputation of the lower extremity are disease (70 percent), trauma (22 percent), congenital or birth defects (4 percent), and tumors (4 percent). As for upper extremity amputation, it is usually performed because of trauma or birth defect. Common traumas that lead to amputation of the limbs include industrial accidents and burns. Among the diseases and conditions that may lead to amputation of an extremity, the most prevalent are hardening of the arteries, arterial embolism, impaired circulation as a complication of diabetes mellitus, gangrene, and severe frostbite. Amputations can be either planned or emergency procedures. The operation is performed under regional or general anesthesia by a general or orthopedic surgeon in a hospital operating room. All amputations consist of a twofold surgical procedure: to remove diseased tissue so that the wound will heal cleanly and to construct a stump that will allow the attachment of a prosthesis or artificial replacement part. After amputation, medication is prescribed for pain, and patients are treated with antibiotics to discourage infection. Physical therapy and rehabilitation are started as soon as possible, usually within 48 hours. Rehabilitation is a long, arduous process. In addition, many people feel a sense of loss and grief when they lose a body part. A large proportion of amputees (50 to 80 percent) experience the phenomenon of phantom limbs; they feel body parts that are no longer there. All the risks associated with the administration of anesthesia exist, along with the possibility of heavy blood loss and the development of blood clots. Infection is of special concern to amputees. Infection rates in amputations average 15 percent. The fiveyear survival rate for all lower extremity amputees is
less than 50 percent. For diabetic amputees, the rate is less than 40 percent. Up to 50 percent of people who have one leg amputated because of diabetes will lose the other within five years. SEE ALSO: Artificial Limbs; Diabetes; Diabetic Foot. Bibliography. The Global Lower Extremity Amputa-
tion Study Group, “Comparing the Incidence of Lower Extremity Amputations across the World,” Diabetic Medicine (v.12/1, 1995); S. Terry Canale, “Amputation,” in Campbell’s Operative Orthopaedics, 10th ed. (Mosby, 2002). Barkha Gurbani UCLA School Of Medicine
Anabolic Steroids Anabolic steroids, more appropriately called anabolic/androgenic steroids, are synthetic and naturally occurring substances related to male sex hormones including testosterone. Anabolic steroids were first discovered in the 1930s. They have been used to treat conditions such as hypogonadism, certain types of impotence, and muscle wasting associated with conditions such as cancer and AIDS. Today, however, the use of anabolic/androgenic steroids is most widely associated with their controversial use as performance enhancing substances in athletic training and competition. Anabolic/androgenic steroids work by increasing protein synthesis and reducing recovery time via blockage of the hormone cortisol’s action on muscle tissues. These effects greatly reduce catabolism of the body’s muscle mass. Anabolic effects of anabolic/ androgenic steroids are increased muscle mass and strength, increased bone remodeling and growth, increased appetite, and stimulation of bone marrow leading to increased production of red blood cells. These effects are maximized when the steroids are combined with proper diet and exercise. Androgenic effects include growth of the clitoris in females and the growth of the penis in male children, impaired spermatogenesis, increased libido, deepening of the voice, and increased growth in androgen-sensitive hair of the beard, chest, limbs and pubic area.
Anal Cancer
Unwanted side effects associated with the use of anabolic/androgenic steroids include possible elevation in blood pressure, acne, hepatotoxicity, gingival overgrowth, elevation in low density cholesterol levels, and lowering of high density cholesterol, which increases the long-term risk of cardiovascular disease. Specific to male users, anabolic/androgenic steroids have also been noted to cause male breast development and transient testicular atrophy. Female users may notice the development of masculine features such as hirsutism, deepening of the voice, and male pattern baldness, as well as abnormal menstrual cycles. Heavy users of anabolic/androgenic steroids are known to take the medications for several weeks or months at a time, and then stop their use for varying periods of time. This use pattern is known as “cycling.” Another common usage pattern is the use of multiple anabolic/androgenic steroids simultaneously, a practice known as “stacking.” Anabolic/androgenic steroids are controlled substances in the United States, and as such can only be obtained legally via a prescription for a legitimate medical need. Most steroids used in the United States are obtained illegally via the black market or the internet. These steroids are smuggled into the United States from other countries with less stringent control of their distribution. The Anabolic Steroid Control Act of 2004 amended the controlled substance act to place anabolic/androgenic steroids and prohormones on a list of controlled substances and made their possession without a prescription a federal crime. The use and abuse of anabolic/androgenic steroids may date back to ancient Greece. The Greeks were believed to have consumed testicular extracts in attempts to promote androgenic and anabolic growth. There are also multiple traditional Chinese medicines that are purported to bolster virility and male performance as well as being oriented toward muscle growth and athletic ability. Modern anabolic/androgenic steroids are available in distinct delivery forms including pills, oil-dissolved or waterdissolved injections, and transdermal forms, which deliver substances through the skin via creams or transdermal patches. Anabolic/androgenic steroids have been reported in all levels of athletic competition. Surveys have demonstrated rates of use in high school students ranging from 1 percent to over 20 percent. Surprisingly,
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not all surveys linked anabolic/androgenic steroid use to athletic training or competition. Some surveys showed significant use by nonathletes in attempts to “bulk up” and improve their physical appearance. Use has been shown to be higher in certain sports such as football, weightlifting, bodybuilding, and track and field. Anabolic/androgenic steroid use also varies within a specific sport. Collegiate linemen were noted to have more frequent usage of anabolic/androgenic steroids than other positions. There has been an increasing push from individuals and organizations around the world to decriminalize the possession and use of anabolic/androgenic steroids. They cite the lack of scientific evidence of harmful side effects with controlled dosing and administration schedules. This push has made its way up to the highest levels of the United States government, as lawmakers in both the House of Representatives and the Senate have been publicly criticized on the government’s stance on anabolic/androgenic steroids. Despite this pressure, the government maintains its position that the risks of using anabolic/androgenic steroids are too great to allow them to be decriminalized and unregulated. See also: Drug Abuse. Bibliography. National Institute on Drug Abuse, “Ana-
bolic Steroid Abuse,” NIH Publication Number 06-3721 (July 2001, revised August 2006); National Institute on Drug Abuse, “Steroids (Anabolic-Androgenic)” (March 2005); Troy Reese and Wade F. Exum, “Anabolic-Androgenic Steroids,” in Ferdy Massimino and Robert E. Sallis, eds., Essentials of Sports Medicine (Mosby, 1997). Rance McClain, D.O. Kansas City University of Medicine and Biosciences
Anal Cancer Anal cancer is very rare. According to the American Cancer Society, approximately 4,600 new cases of anal cancer are diagnosed per year in the United States. Due to the relatively easily accessible location of the anus, anal cancer is typically readily diagnosable. The
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farther up in the anus that the cancer begins, the more difficult it is to access, and hence the more difficult to diagnose early. Risk factors for anal cancer include being a female who has had cervical or vulvar cancer, anyone with HIV or AIDS, all recipients of a transplant, and all individuals who receive anoreceptive intercourse. People living with HIV or AIDS as well as transplant recipients are at an increased risk for anal cancer because of their immunocompromised state. Human papillomavirus (HPV) infection appears to be related to anal cancer incidence. HPV resides in mucous membranes, specifically in those membranes of the mouth and throat as well as the ano-genital area. People infected with high-risk strains of HPV, as well as those individuals infected with multiple HPV strains, are at an increased risk for developing anal cancer, as compared to the non-HPV-infected population. Low-risk HPV strains may cause genital warts in some people; low-risk HPV strains are not associated, however, with cancer. Additionally, despite being treated with intensive antiretroviral medications, men and women living with HIV in the United States do not have a decreased incidence of anogenital cancers stemming from HPV. The anal tissue is composed of skin and the large intestine, which ends in the anus. The anus is the final part of the body that stool passes through before being ejected. Often symptoms of anal cancer are also associated with other disorders such as hemorrhoids, anal warts, or fissures, so it can be difficult to suspect anal cancer without a clinical examination. These symptoms include anal bleeding, discharge, itchiness, pain, and bumps. Another symptom might be a change in the diameter of the stools. Anal bleeding is predominantly the first symptom of an anal canal cancer. The simplest method for spotting anal cancer is the digital rectal exam (DRE), whereby a doctor inserts his or her gloved, lubricated finger into the anus to examine the male prostate or female pelvic area for lumps. During the DRE, the doctor may find suspicious lumps or growths in the anus, as well. Most men over 50 years of age are recommended to have a DRE once per year. Another screen for a type of anal cancer called anal intraepithelial neoplasia (a localized noninvasive cancer) is the anal cytology test, often called the anal Pap smear as it is reminiscent of the Pap smear in female gynecological exams. A swab of cells from inside the anus is taken and exam-
ined microscopically for unusual cellular growth. A positive result would suggest the patient be referred for a biopsy. Endoscopy may also be used, whereby a long, thin tube, often with a light and/or camera on one end, is inserted into the anus and used to visually examine the rectum, anus, and final part of the large intestine. Endoscopy is usually not painful, and may require that a patient takes laxatives beforehand, to clear the bowels. If a suspicious growth or lump is detected, the next step in the diagnostic exam is a biopsy. A biopsy is when the doctor takes a small sample of tissue from the suspicious area, and gives it to pathologist who will examine it microscopically for abnormalities. If the examining doctor can remove the entire tumor with the biopsy alone, he or she will most likely do so. There are different additional biopsy methods. Fine-needle aspiration biopsy is used to remove a small sample of fluid and cells from the lymph tissue surrounding the site in question. A pathologist will examine the sample to determine if the tumor has spread into the lymph nodes. Another biopsy for testing if a previously diagnosed cancer has spread to the lymph nodes is called sentinel node biopsy. A safe level of radioactive tracer compound is injected into the tissue surrounding the tumor, and then lymph nodes are examined for accumulation of the tracer. If the lymph nodes contain cancer cells, it is evidence that the cancer has spread. Once a cancer is diagnosed, there are medical imaging technologies that can help determine the stage of progression of the cancer, which will determine the treatment methodology used. An ultrasound can be used to monitor the spread of the tumor as it invades nearby tissues. A computed tomography, or CT, scan uses X-rays to determine if the cancer has spread to other tissues or organs. CT scans are typically performed on the abdominal and pelvic regions. There are different types of anal cancer. If the tumor is in the anal canal, whether the mucosa is of keratinized or nonkeratinized skin cells, it is generally treated in similar fashions. Anal canal cancers also result in a similar prognosis. In contrast, adenocarcinomas (epithelial cell cancers arising in glandular tissue) are typically managed as rectal cancers. Treatment options for anal cancer include chemotherapy, radiation therapy, and, for the most severe cases, surgery. In many situations, a combination
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treatment of radiation therapy and chemotherapy can clear the cancer from a patient. This combination is used in order to lessen the negative side effects of chemotherapy. The need for surgery depends on how deeply the tumor has invaded in the anal tissue, as well as how far the cancer may have spread in the body. Surgery used to be the treatment of choice, prior to the decade of the 1980s. In that time, the surgery performed was abdominoperineal resection, an operation which entirely removes a patient’s rectum, anus, and the lymph nodes draining these organs. Today, such a drastic procedure is rarely, if at all, performed. SEE ALSO: AIDS; AIDS-Related Malignancies; American
Cancer Society (ACS); Anal/Rectal Diseases; Cervical Cancer; Colorectal Cancer; Organ Donation; Vulvar Cancer. Bibliography. American Cancer Society, “How Is Anal
Cancer Diagnosed?”, www.cancer.org (cited June 2007); C. Eng, “Anal Cancer: Current and Future Methodology”, Cancer Investigation (v.24/5, 2006); ICON Health Publications, Anal Cancer—A Medical Dictionary, Bibliography, and Annotated Research Guide to Internet References (Icon Health Publications, 2004); J. Palefsky, “Human Papillomavirus-Related Tumors in HIV”, Current Opinion in Oncology (v.18/5, 2006); Hope E. Uronis and Johanna C. Bendell, “Anal Cancer: An Overview”, The Oncologist (v.12/5, 2007). Claudia Winograd University of Illinois at Urbana-Champaign
Anal/Rectal Diseases The final region of the digestive system, the rectum has similar basic functions as the rest of the colon for absorption of water and minerals into blood, and preparation of the feces to leave the digestive tract. The cells of the rectum are glandular and secret mucus used in production of feces and to lubricate the lower portions of colon. The presence of folds in its walls called rectal valves help support the weight of the feces and prevent involuntary elimination from the force of gravity. The anus is the external opening of the anal sphincter, through which movement of feces is normally under voluntary control.
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Anal or Rectal Abscess Abscesses are pus collection from bacterial invasion and occur in the intermuscular space where a crypt has formed. The two types are superficial (near the surface), and deep. Superficial abscesses may be painful with swelling, redness, or tenderness. Deep abscesses sometimes produce toxic symptoms with less severe pain. Abscesses formed in the higher regions of the rectum may cause lower abdominal pain or fever, and are sometimes associated with inflammatory bowel diseases. Treatment is by incision and drainage. Antibiotics have limited usefulness in those patients who are febrile, diabetic, or have developed a systemic infection. Anal atresia Anal atresia is a congenital anomaly in which the anus is not formed appropriately to function properly. If it is unnoticed on physical exam, it becomes apparent after feeding, with symptoms of distal bowel obstruction. In infant males, a fistula (tube) is formed that reaches from the anal pouch to the perineum or urethra. In infant females, the fistula reaches from the anal pouch to the vagina, fourchette, or urethra. Testing is done by collecting and filtering the urine to test for meconium (first discharge from the bowels). Treatment of cutaneous fistulas can be corrected by surgery, higher lesions should not be treated until the infant is older, the structures involved are larger, and temporary relief of obstruction is accomplished by colostomy. Bleeding The passage of blood through the rectum, called hematochezia, often indicates lower gastrointestinal tract source and black tarry stool, called melena, is a typical indication of upper gastrointestinal tract source. Gastrointestinal bleeding may result from various diseases, diverticular diseases, colonic carcinoma, polyps, inflammatory bowel disease, internal hemorrhoids, and anal fissures. Diagnosis includes a complete history and physical, and a chemical test to detect the presence of occult blood in the stool. A digital rectal exam can determine the presence of masses, fissures, and hemorrhoids. Sigmoidoscopy will show evidence of hemorrhoids, infectious bowel disease, polyps, and cancer. A colonoscopy will help detect polyps, ulcers, and tumors.
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Most lower gastrointestinal tract bleeding does not require emergency therapy. Treatment for severe bleeding includes preventing complications of blood loss, stabilizing the blood pressure, and supplying blood through transfusion if the patient is at risk for further hemorrhage. To stop bleeding in emergency situations, coagulation, laser treatment, and surgery may be necessary. Once the patient is stable and the cause of bleeding is diagnosed, treatment will proceed for the specific disease. Cancer The uncontrolled growth of cells common types in anorectal cancer include adenocarcinoma, melanoma, and lymphoma, with the potential for these cells to metastasize and spread to other parts of the body. The incidence of colorectal cancer increases after the age of 40 and peaks between ages 60 and 75. Adenocarcinoma grows slow with a long interval before symptoms appear. A positive test for occult blood indicates further testing. A colonoscopy is used to diagnose cancer, although no specific blood test for colorectal cancer exists, the serum levels of tumor markers may be elevated. Treatment is by removal of lesions. Depending on the level of involvement of the lymph nodes, additional treatment with radiotherapy and chemotherapy or a combination may be necessary to control local tumor growth, to delay recurrence, and improve survival. Oncologists, physicians whose specialty is cancer treatment, oversee the administration of chemotherapeutic medication. Fluorouracil is used alone or in combination with leucovorin. Fluorouracil is an antimetabolite acting on the cell’s biochemical pathway leading to cell replication. Fluorouracil metabolites inhibit DNA synthesis and incorporation into RNA to interfere with RNA function. Given intravenously for colorectal cancer, side effects may include nausea, oral and gastrointestinal ulceration, and bone marrow suppression. Leucovorin is used to rescue normal cells from destruction. The incidence of anal cancer increases in patients who are HIV positive and especially among those who practice male homosexual behavior. The incidence may increase due to human papilloma virus rather than from HIV itself. Treatment of this cancer includes surgery, chemotherapy with mitomycin, cisplatin and fluorouracil. Mitomycin is an antibiotic alkylating agent to cross-link DNA and attack hypoxic tumor stem cells. Side effects include nausea and vomiting and se-
vere myelosuppression, bone marrow suppression, potential renal toxicity and interstitial pneumonitis. Even with its high toxicity mitomycin is a first-line treatment for hypoxic tumor stem cells and is considered a second-line agent for use in metastatic colon cancer. Cisplatin is an inorganic metal complex containing platinum acts as an alkylating agent to destroy cells at any stage, inhibiting DNA synthesis and binding DNA by forming cross-links. Side effects include nausea and vomiting with little effect on the bone marrow. Screening allows for early detection and diagnosis. Recommended screening includes annual testing of the stool for occult blood after the age of 50, annual rectal examinations after the age of 40 and a sigmoidoscopy every three to five years after the age of 50. Anal Fissure Fissures are longitudinal tears or chronic ovoid ulcers caused by traumatic laceration with large or hard feces and may result in secondary infection. Trauma by anal intercourse is possible but rare. Fissures cause pain and bleeding with defecation and the pain may continue. Treatment is noninvasive with the use of stool softeners and bulking agents to minimize trauma. Glycerin suppositories lubricate and soften the tissue to promote healing. Warm sitz baths ease the discomfort. When noninvasive treatments fail, surgery may be necessary to repair the tear or ulcer. Anorectal Fistula Anorectal fistulas are tube like openings with one end of the tube in the anal canal and the other end opening in the peri-anal skin. Fistulas originate in crypts, diverticulitis, tumors, or the result of trauma, and are common in patients with a history of recurring abscesses with drainage. Surgical treatment is used to destroy the tube in the anal canal. Foreign bodies Foreign objects lodged in the rectum can be introduced into the rectum or anus by swallowing (toothpicks, bones in food), body processes (gallstones or rectal stones), erosion (urinary calculi, surgical sponges/instruments), or from intentional introduction with unintentional lodging (sexual play). The object is caught in the rectal wall or trapped above the rectal sphincter. The patient may feel sudden excruciating pain during elimination that continues for a while and then
may stop with repeating character. Infection may occur. Treatment includes using a local anesthetic and then removing the object manually. If the object cannot be palpated, the patient should be hospitalized while the peristaltic movements of the muscles in the rectal wall work the object down, and then follow the same removal procedure. Hemorrhoids Hemorrhoids, also called piles, are inflamed and swollen veins around the anus or in the lower rectum. They are caused by straining during elimination, pregnancy, and chronic diarrhea or constipation. Symptoms of bright red blood and pain or itching usually resolve within a few days. Bleeding should be checked by a physician to make sure it is not from a more serious disease. Over-the-counter preparations are available to relieve itching and inflammation. Inflammatory Bowel Diseases Inflammatory bowel diseases are characterized by colitis, an inflammatory disease of the colon, and may have symptoms of diarrhea and profuse bleeding. Diseases within this category are Crohn’s disease, ulcerative colitis, and infectious colitis. Definitive diagnosis of inflammatory bowel disease must differentiate between the different types. Infectious colitis is inflammation and can be established by stool culture and rectal biopsy. Crohn’s disease is more common in the small intestine, although it may occur anywhere in the gastrointestinal tract. With age of onset under the age of 30, it appears to have genetic factors involved, though the origin is not fully defined. Lesions and ulcers form in the mucosa and can thicken to fibroids. The tissue involved tends to have healthy areas interspersed with injured areas. Patients may complain of chronic diarrhea with pain, fever, weight loss, and symptoms similar to obstruction or appendicitis. Crohn’s may progress from inflammation to partial and/or chronic obstruction to fistulas and abscesses. Treatment includes alleviating symptoms with anti-diarrheal medication. Some people benefit from special diets. Corticosteroids may be used for acute stages and temporary symptom relief, though contraindicated when infection is present. Immunomodulating drugs can be effective for long-term therapy by reducing the need for corticosteroids, healing fistulas and maintaining remission to improve clin-
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ical status. Surgery may be necessary to remove intestinal obstruction or fistulas. No specific cure is available, though numerous medications are being used worldwide for investigational purposes. Ulcerative colitis is a chronic inflammation and ulceration in colonic mucosa. Average age of onset tends to occur in two peaks—one between the ages of 15 and 30 and another between the ages of 50 and 70. Ulcerative colitis, similar to Crohn’s, appears to have genetic factors involved, though the origin is not fully defined. Beginning with inflammation, crypt abscesses and mucosal ulceration may develop in the rectosigmoid. Ulcerative proctitis is the form of ulcerative colitis localized in the rectum and is more common and less invasive. Symptoms vary depending on location of inflammation and include abdominal cramping, urge to eliminate, and blood and mucous in the stools. In the rectum the feces may be normal though accompanied by mucous. Pruritis Itching may occur secondary to a variety of causes: dermatologic, allergic reactions, superficial infections, parasites, from the use of oral antibiotics especially tetracycline, systemic disease, proctological origin of skin tags, crypts, tumors, poor hygiene and a warm and moist environment. Simple changes in lifestyle can relieve the itching, such as eliminating foods known to cause itching, like spices, citrus, coffee, beer, and cola. It often brings relief to wear loose and breathable clothing to prevent heat and moisture build up, to cleanse properly, and to apply talcum powder or cornstarch to combat moisture. Hydrocortisone cream can be used to alleviate itching. If the cause is parasitic, a fungicide can be prescribed. Systemic causes must treat the specific disease causing the pruritis. Polyps Polyps are masses of tissue arising from the bowel wall and protruding into the anal canal. Polyps often appear in multiples and may co-exist with cancerous tissue. Symptoms of polyps can range from having no symptoms to rectal bleeding or cramping. Abdominal pain or obstruction may signal the presence of large lesions. Diagnosis is often discovered by sigmoidoscopy or endoscopy. Treatment requires removal of polyps. The tissue should be tested for malignancy as
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the potential exists for large polyps to contain cancerous cells. Proctitis Inflammation of the rectal mucosa of unknown origin. Infectious bowel disease, sexually transmitted diseases (more common in homosexual males) or other infections may be implicated. Diagnosed by culture of smears of the rectal wall to determine bacterial, viral or fungal activity. Appropriate medication therapy involves doxycycline, sulfamethoxazole-trimethoprim, metronidazole or vancomycin if appropriate. Rectal Prolapse Prolapse is the protrusion of the rectum through the anus. Transient minor prolapse may appear in infants and children and often naturally repairs. Prolapse in adults frequently occurs in females over the age of 60. Symptoms include protrusion while straining and in advanced cases during walking or standing. Bleeding and incontinence may be frequent symptoms, though pain is usually absent. Simple mucosal prolapse involves mucosal tissue and the excess tissue may be excised or ligated. Procidentia is the prolapse of the entire thickness of the rectum and surgical elevation can be used to correct the displacement. SEE ALSO: Chemoradiotherapy; Chemotherapy; Colorec-
tal Cancer; Constipation; Diarrhea; Gastroenterology; Hemorrhoids. Bibliography. “Anal and Rectal Diseases,” www.nlm.nih.
gov/medlineplus; Sydney E. Salmon and Alan C. Sartorelli, “Cancer Chemotherapy,” Basic and Clinical Pharmacology (Appleton and Lange, 1998).
Lyn Michaud Independent Scholar
Andorra With a temperate climate that produces cold, snowy winters and warm, dry summers, Andorra draws tourists from around the world. Made up of only 468 square kilometers, this southwestern European nation has a population of 71,201. Tourists are also attracted
to the low tax base, and residents from neighboring European countries regularly shop in its stores. Altogether, tourism accounts for more than 80 percent of the Gross Domestic Product (GDP) of Andorra. The absence of income taxes also attracts immigrants, both legal and illegal. The per capita income of $24,000 places Andorra 41st in world incomes. As a result, the standard of living and access to healthcare are high, and travelers to Andorra are usually impressed with the quality of available medical services. The government reports a zero unemployment rate, and there is no identifiable poverty in Andorra. In 2004, Andorra agreed to cooperate with the European Union on a number of economic, social, and cultural accords. Despite the high standard of living, data on many health indicators are unavailable for Andorra. Healthcare is considered a fundamental right in Andorra, and Article 30 of the constitution guarantees citizens that the government will protect their health by providing social security, which is financed by cooperation between the public and private sectors. This guarantee was supplemented by the passage of the General Law on Health in March 1989. Spending on healthcare is consequently high in Andorra, although it has fluctuated some. Between 1998 and 2003, spending fell from 7.2 percent of the GDP to 4.9 percent. By 2006, the percentage had again risen and is currently 7.1 percent of total GDP. Andorra allots $2,453 (international dollars) per capita for healthcare services. The government covers 68.6 percent of total health expenditures, earmarking 89.2 percent for social security. The private sector furnishes 31.4 percent of total healthcare outlays, and 71.10 percent of that amount is derived from out-of-pocket expenses. There are 3.70 physicians, 3.11 nurses, 0.15 midwives, 0.68 dentists, and 1.03 pharmacists per 1,000 population in Andorra. At 83.51 years, Andorra has the highest life expectancy in the world. Females can expect to outlive males by an average of six years. Literacy is universal. One hundred percent of children complete primary school, but enrollment at the secondary level is only 81.3 percent. One hundred percent of Andorrans have access to safe drinking water and improved sanitation. On average, women in Andorra give birth to 1.3 children each. This is the 16th lowest fertility rating among nations of the world. The infant mortality rate of 4.04 deaths per 1,000 live births is the 10th lowest in the world. The un-
Anemia
der-5 mortality rate is also low at 7 per 1,000 live births. In general, immunization rates are predictably high. Ninety-nine percent of infants are immunized against diphtheria, pertussis, tetanus (DPT1 and DPT3), and tuberculosis, 98 percent against measles, and 95 percent against Haemophilus influenzae type B. However, only 54 percent of infants receive hepatitis B vaccinations. SEE ALSO: Healthcare, Europe. Bibliography. Central Intelligence Agency, “Andorra,”
World Factbook, www.cia.gov (cited January 2007); Commission on the Status of Women, “Andorra,” www.un.org/ womenwatch (cited January 2007); Spencer Di Scala, Twentieth Century Europe: Politics, Society, Culture (McGraw-Hill, 2004); Sandra Halperin, War and Social Change in Modern Europe: The Great Transformation Revisited (Cambridge University Press, 2004); Martin A. Levin and Martin Shapiro, eds., Transatlantic Policymaking in an Age of Austerity: Diversity and Drift (Georgetown University Press, 2004); United Nations Children’s Fund, “Andorra,” www.unicef.org (cited January 2007); World Bank, “Andorra Data Profile,” devdata.worldbank.org (cited January 2007); World Health Organization, “Andorra,” www.who .int (cited January 2007). Elizabeth R. Purdy, Ph.D. Independent Scholar
Anemia Anemia is defined as an insufficient quantity of normal red blood cells (RBCs) or decreased levels of hemoglobin. Hemoglobin is the iron-containing protein present in RBCs. It is synthesized in the mitochondria of the RBC as the cell develops within the bone marrow. Subsequent to maturation, the RBC enters the vasculature where it functions to transport oxygen throughout the body. Anemia is quite variable in the sense that it can result from impaired red cell production, increased red cell destruction, and/or significant blood loss. There are many serious health consequences associated with anemia, and it can act to make individuals more susceptible to other adverse health events. Often, it is difficult
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to determine if health complications are the result of anemia or serve to produce the anemia conditions. The variation among the etiologies of anemia has thus fostered health professionals to categorize the disorder into more specific terms. The class of anemia that receives the most attention is nutritional iron deficiency anemia (IDA). Inadequate intake of iron, poor iron availability, or increased utilization of iron can lead to iron deficiencies within the body, which can evolve in stages beginning with depleted iron stores. This stage is indicated when hemoglobin levels are at an adequate level but iron is no longer stored in tissues, as indicated by low serum ferritin levels. As iron availability begins to depreciate, normal erythropoeisis, the development of RBCs that requires the greatest amount of iron, becomes interrupted and leads to the stage known as iron-deficient erythropoeisis. However, in this stage, hemoglobin levels continue to remain at normal values but are accompanied by an increase in transferrin receptor (TfR). The deteriorating iron supply eventually inhibits the production of hemoglobin, decreasing the levels to below normal cutoff values, and culminates in the final stage known as IDA. Macrocytic anemias are often the result of inadequate intake or absorption of vitamin B12 or folic acid caused by diet, disease, or medication use. Pernicious anemia is a type of megaloblastic macrocytic anemia, a chronic illness that occurs when the stomach fails to produce intrinsic factor to assist in the absorption of vitamin B12. Both vitamin B and folic acid are required for proper DNA production and thus successful erythropoeisis. Deficiencies in one of these micronutrients can also stimulate deficiencies in the other. When erythropoeisis is interrupted, macrocytes, abnormally large RBCs with irregularly shaped nuclei, and megaloblasts, the precursor to RBCs, are present in the blood vessels and bone marrow, respectively. Macrocytic anemias can also be initiated by causes not associated with vitamin B12 or folic acid deficiencies, such as viral illnesses (e.g., HIV), bone marrow diseases, and other infections that inhibit DNA synthesis. These macrocytic anemias may or may not be accompanied by the presence of megaloblasts. Hemolytic anemia, a general category of nonnutritional forms of anemia, includes hemogloblinopathies that are genetic blood diseases such as sickle-cell anemia and thalassemia; autoimmune diseases; and
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infections such as malaria, toxins/drugs, and trauma. Hemolytic anemia occurs when RBCs are prematurely destroyed and bone marrow cannot produce enough RBCs to compensate for the decline, resulting in decreased levels of RBCs. In this case, low levels of hemoglobin are typical and accompanied by elevated levels of bilirubin and reticulocytes, the precursors to RBCs. Toxins, medications, and autoimmune disorders may not only induce hemolytic anemia, but may also contribute to aplastic anemia by impairing red bone marrow, leading to decreased production of RBCs, as well as leukocytes and platelets. This anemia is a common concern in the use of radiation therapy for the treatment of cancer patients. Significant blood loss due to trauma, disease, and/ or infections may give rise to hemorrhagic anemia. A common contributor to such anemia is the presence of parasitic infections. Hookworms are responsible for significant blood loss, attributable to the feeding habits in which they attach to the gut wall and secrete an anticoagulant, resulting in blood loss. Other parasites, such as Trichuris and Schistosoma, can cause anemia due to blood loss via dysentery and urinary blood loss, respectively. Diagnosis Diagnosis of anemia is dependent on clinical presentations as well as medical tests. Symptoms characteristic of anemia typically include pallor of the eyelids, lips, tongue, and underneath fingernails; fatigue; complications in cognition; dizziness; headaches; and dyspnea. Patient histories, including nutrition, pregnancy, menstruation, and disease as well other clinical presentations, may assist in determining the specific form of anemia and/or its underlying cause. To further diagnose anemia, several blood tests can be utilized. Most widely accepted is the World Health Organization (WHO) definition of anemia. Anemia is defined when a patient has a hemoglobin level, with or without decreases in RBC concentration, below that of the accepted international WHO cutoff values: men <13.0g/dl, women <12g/dl, pregnant women <11.0g/dl, infants <10.5g/dl, and children <11.0g/dl. Hematocrit, the percentage of RBCs present in the total blood volume, as well as red blood cell and complete cell blood counts, are also commonly used measures of anemia. Despite the fact that hemoglobin, hematocrit, and RBC measurements are com-
monly accepted, easy to use, and relatively inexpensive, the sensitivity and specificity of these measures cannot detect mild IDA and can vary significantly with conditions of pregnancy, disease and infection, and smoking, thus, promoting the current search for more precise methods. Other diagnostics that have recently become accepted to identify IDA include serum ferritin and serum transferrin receptor (sTfR) measurements. These tests, usually performed using more complex enzyme linked immunoassay methods, reflect the body’s iron stores. Decreases in serum ferritin (<12ng/mL) or increases in serum transferrin receptor (>8.0μg/mL) indicate IDA. Research has promoted the use of TfR measurements for detecting IDA, as it is not hindered by conditions of pregnancy or infection. Blood smears, or blood films, also assist in the diagnosis of anemia and its source. IDAs are often characterized by microcytic, sometimes hypochromic, RBCs. Conversely, the presence of macrocytic cells may indicate a deficiency of vitamin B or folic acid, and may be followed with other laboratory diagnostics for differentiation of the anemia and/or associated deficiencies. The presence of other irregularly shaped or destroyed RBCs can also indicate other diseases, such as sickle cell disease that exhibits a characteristic RBC shape, or other infection, such as malaria. Confirming the destruction of RBCs, laboratory tests often indicate increases in bilirubin levels, the product of hemoglobin destruction in the kidney. Treatment and Control Healthcare professionals treat severe anemia with great priority, as it has been associated with complications in cognition, depression, neurological disorders, and/or cardiac decomposition among patients. Furthermore, anemia during pregnancy has been associated with adverse events during parturition, as well as cognitive impairment, and neurological disorders in the newborn and later in development of the child. Treatment of anemia is dependent on the etiology of the condition. Most often, individuals are prescribed nutritional counseling and/or supplements for nutritional deficiencies. However, gastrointestinal side effects are known to occur in about 25 percent of the patients receiving iron supplementation. Pregnant women, as a high-risk group, have become the target for iron/folic supplementation using a typical dosage
Aneurysms
of 60mg iron with 400μg folic acid per day. Iron fortification of common foods has also been implemented in many areas to control anemia within populations with high prevalence of IDA. In the case of anemia associated with parasitic infections, deworming methods or treatment for other infections should be combined with supplementation. Drug therapies have been designed to treat aplastic anemias by stimulating the production of RBCs by mimicking the body’s natural RBC-producing hormones using erythropoeitin and interleukin-3. In the case of severe anemias, blood transfusion with antibiotics and hospitalization is sometimes necessary. Overall, it is important to note that anemia can be the result of many varying etiologies and, thus, determining the treatment is dependent on the etiology, severity, patient characteristics, and resources available. Treatment of the underlying causes of anemia is of particular importance, especially in cases of disease, to prevent anemia from continuing and exacerbating other conditions. Epidemiology The control of anemia has reached significant priority in public health, especially within developing countries, as a result of its extreme prevalence, preventability, and adverse outcomes. The WHO proposed the elimination of anemia as a key feature of the Safe Motherhood Program, and targets anemia in many other intervention programs as well. The increase in priority is a result of estimates that greater than onethird of women worldwide and one-half of the women and children in developing countries are currently anemic. Additional estimates suggest that 16,800 to 28,000 deaths among women of reproductive age, especially young women, are attributable to anemia. Unfortunately, estimates are uncertain and can vary given the diagnostic abilities, reporting, hospital attendance, and priorities of each health setting and region. Further geographical estimates calculated in 2001 have suggested the all-cause mortality associated with anemia is 6.37, 7.26, and 3.0 percent in Africa, Asia, and Latin America, respectively. Anemia is often implicated in other health problems of these developing countries including infectious diseases. In developing countries, anemia due to malaria, helminthes, HIV, and other infections accounts for a significant proportion of anemia in
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the populations. This is in contrast to industrialized countries in which iron deficiency, accounting for 50 to 80 percent of the cases, is followed by anemia associated chronic disease. SEE ALSO: Hematology; High Risk Pregnancy; Nutrition;
Sickle Cell Anemia; Women’s Health (General); World Health Organization (WHO). Bibliography. Florence Aslinia, Joseph Mazza, and
Steven Yale, “Megaloblastic Anemia and Other Causes of Macrocytosis,” Clinical Medicine & Research (v.4/3, 2006); Marcel Conrad, “Anemia,” in Clinical Methods (Butterworth Publishers, 1990); Merck, “Chapter 127: Anemias,” The Merck Manual of Diagnosis and Therapy, 17th ed. (Merck, 2006); Tanuja Rastogi and Colin Mathers, “Global Burden of Iron Deficiency Anaemia in the Year 2000,” in WHO Global Burden of Disease 2000 (draft) (World Health Organization, 2000); Paul Schick, “Megaloblastic Anemia,” eMedicine, www.emedicine.com (cited October 2006); Heather Taylor, Anemia Detection Methods in Low-Resource Settings: A Manual for Health Workers (U.S. Agency for International Development, 1997); G. J. Torta and B. Derrickson, “The Cardiovascular System: The Blood,” in Principles of Anatomy and Physiology (Wiley, 2006). Andrea L. Wirtz Johns Hopkins University School of Public Health
Aneurysms An aneurysm is defined as a localized, pathological, blood-filled dilatation of a blood vessel caused by a disease or weakening of the vessel’s wall. These diseases include, but are not limited to, atherosclerosis, hypertension, syphilis, trauma, congenital malformations, and bacterial and fungal infections. Aneurysms fall into one of two general categories: True aneurysms, which involve all three layers of the artery (intima, media, and adventitia), and false aneurysms, which do not involve all of the layers. Aneurysms most commonly occur in the abdominal aorta, thoracic aorta, and intracranial arteries, but can also affect the coronary, femoral, popliteal, splenic, carotid, and renal arteries. The shape of an aneu-
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rysm is either saccular (like a sack) or fusiform (like a spindle). Both are susceptible to growth, rupture, and dreadful consequences. Abdominal Aortic Aneurysms Abdominal aortic aneurysms (AAA) are defined as an aortic diameter of at least 1.5 times the diameter measured at the level of the renal arteries. In most people, this diameter works out to be 3 centimeters. Abdominal aortic aneurysms are the most common type of aneurysms and occur between the renal and inferior mesenteric arteries. (Anything located more superiorly is a thoracic aortic aneurysm.) They are true aneurysms and therefore involve all layers of the aorta. Atherosclerosis is considered the most common cause of AAA, although other etiologies include cystic medial necrosis and infections. Aneurysms are also associated with diseases such as Marfan and Ehlers-Danlos syndromes. In the United States, AAA kills 15,000 people per year and is the 10th most common cause of death for people older than 55 years. Why and how abdominal aortic aneurysms develop is uncertain, although there are theories. The fact that AAA develops in many members of some families suggests a genetic basis, and chromosome 19 has been implicated. Another possibility involves enzymes called proteases that destroy important components of the arterial wall such as elastin and collagen. Finally, it is thought that inflammation in the arterial wall may play a role in the development of AAA as well. Risk factors for the development of AAA include age greater than 60 (5 to 10 percent prevalence), male sex, Caucasian race, atherosclerosis, hypertension, and a family history of the disease. The strongest risk factor for developing AAA, however, is cigarette smoking. Cigarette smoking carries an odds ratio of 5 (i.e., a smoker is five times more likely to develop AAA than a nonsmoker) and a longer history of smoking confers a greater risk. It is estimated that smoking alone causes 75 percent of all AAA greater than 4 centimeters in diameter. Smoking also increases the rate at which an aneurysm grows. Patients with AAA are frequently asymptomatic and the disease is discovered only incidentally via imaging studies obtained for other reasons. The two most important symptoms are abdominal or back pain as well as abdominal tenderness to palpation. Other findings on physical examination may include
a pulsatile mass at or above the navel, which is approximately where the aorta divides and a common location for AAA, as well as an audible bruit (a harsh, shooting sound of blood flowing) when the abdomen is auscultated with a stethoscope. Patients with a ruptured aneurysm will be hypotensive due to exsanguination of blood into the abdominal cavity; the survival rate of patients with ruptured AAA is less than 50 percent. The diagnosis of AAA can be accomplished with physical examination and imaging studies. As mentioned, physical examination may reveal a pulsatile abdominal mass. Imaging studies include ultrasonography (preferred), computed tomography (CT), and magnetic resonance imaging (MRI).A small percentage of patients with AAA have an entity called inflammatory aneurysm. Additional findings of inflammatory aneurysm include weight loss and an elevated erythrocyte sedimentation rate (a type of blood measurement indicative of systemic inflammation). The treatment of AAA is medical and/or surgical. Medical therapy involves quitting cigarette smoking, as well as reducing risk factors such as high blood pressure and high cholesterol (such as with beta-blocker and statin medications, respectively). Researchers are also looking into the role of antibiotic therapy, given the role that infection may play in AAA development. Records show that surgery for AAA was attempted since the 100s c.e. in ancient Rome, but success did not occur until the 1920s. Surgical therapy involves replacement of the aneurysm with a prosthetic graft, although endovascular techniques are also being developed. The indications for surgery include aneurysms that are symptomatic and any aneurysm greater than 5.5 centimeters in diameter. Cases that are planned in advance are now associated with a low mortality rate of less than 5 percent, but emergent cases for aneurysm rupture have a mortality rate of greater than half. The chances for surgical success are improved at a hospital and with a surgeon who does many procedures repairing AAA. Just like there are risk factors for aneurysm development, there are risk factors for aneurysm rupture. These factors include aneurysm diameter, rate of expansion, and gender. The annual rupture risk depends on the size of the aneurysm diameter: 0 percent for aneurysms less than four centimeters, 3 percent for aneurysms four to five centimeters, 10 percent for five to six centimeters, 15 percent for six to seven centime-
ters, 30 percent for seven to eight centimeters, and 40 percent for aneurysms greater than eight centimeters. In terms of aneurysmal expansion rate, the faster an aneurysm expands, the increased risk it has of rupturing. In addition, larger aneurysms tend to expand more rapidly. Last, although males are more likely to develop AAA, females have a four times higher risk of aneurysm rupture. Other factors that increase the risk of AAA rupture include smoking and hypertension. Patients at risk of developing AAA should undergo screening examinations. Men between the age of 65 and 75 should be screened once with ultrasound if they ever smoked cigarettes. Men who are older than 60 years with a nuclear family history of AAA should also be screened. Other current recommendations are to monitor aneurysms three to four centimeters in diameter with ultrasound every few years, while aneurysms four to five centimeters in diameter should be monitored with ultrasound or CT every six to 12 months. Thoracic Aortic Aneurysms Thoracic aortic aneurysms (TAA) are less common than abdominal aortic aneurysms but are just as frightening. Even more frightening is the fact that one-fifth to one-fourth of patients with TAA have a coexisting AAA. TAA occur at an incidence of six per 100,000 patient-years and are more common in males in their 50s and 60s. TAA are divided into four anatomic categories: ascending aorta, aortic arch, descending aorta, and thoracoabdominal. Two classification systems exist, namely the DeBakey and Stanford systems. Aneurysms that originate in the ascending aorta and involve the aortic arch (30 percent of TAA) are termed DeBakey Class I. DeBakey Class II aneurysms involve the ascending aorta only (20 percent). DeBakey Class III aneurysms originate in the descending aorta and comprise the other half of TAA. In the Stanford system, group A aneurysms have involvement of the ascending aorta, while group B aneurysms involve only the aortic arch and descending aorta. Cystic medial degeneration (or necrosis) is a natural process whereby the middle layer of an artery degenerates and consequently weakens the blood vessel. Atherosclerosis is a major cause of cystic medial degeneration, as is protease-mediated breakdown of vascular proteins such as elastin and collagen. These processes are the pathophysiology behind vessel dila-
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tation and TAA formation. The biggest risk factor for cystic medial degeneration and TAA is hypertension. Two genetic conditions also present patients with a higher risk of developing TAA, namely Marfan and Ehlers-Danlos syndromes. Other risk factors include a family history (which is often due to mutations in the transforming growth factor beta receptor 2 gene), a bicuspid aortic valve, and infectious or inflammatory disorders of the esophagus (such as giant cell arteritis, syphilitic aortitis, etc.). Patients with TAA are usually asymptomatic. Symptoms, when they do occur, are usually due to compression of other structures and vessels by the aneurysm, or from emboli spewed off from the aneurysm causing ischemia of different organs. Such symptoms can include pain in the chest, back, flank, or abdomen. Furthermore, compression of the vagus or recurrent laryngeal nerves can cause vocal hoarseness; compression of the trachea, bronchi, or lungs can cause respiratory symptoms such as wheezing, coughing, or shortness of breath; compression of the phrenic nerve can cause paralysis of the diaphragm; and compression of the esophagus can cause problems with swallowing. Also, an ascending TAA can cause aortic regurgitation, which can itself cause heart failure. A ruptured TAA can cause pain, hypotension, shock, or even hematemesis (coughing up blood). The most important factor related to the actual rupture of TAA is the aneurysm size. The five-year risk of rupture is 0 percent for aneurysms less than 40 millimeters in diameter, 15 percent for aneurysms 40 to 59 millimeters, and 30 percent if the aneurysm is 60 millimeters or larger. On average, ascending TAA are about 60 millimeters in diameter at time of rupture while descending TAA are about 70 mm. Thoracic aortic aneurysms grow anywhere between one to 10 millimeters per year, and the aneurysms that grow fastest are the ones that are already large or are located along the descending aorta. The preferred methods of diagnosing TAA are CT and magnetic resonance angiography (MRA). Other options include chest X-ray, echocardiography, and contrast angiography. The medical treatment of asymptomatic TAA includes blood pressure control (with beta-blocker medications), surveillance, and serial imaging to monitor the growth of the aneurysm. Aneurysms require surgical intervention if the patient is symptomatic; the size of the aneurysm
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is greater than 50 millimeters or 60 millimeters for ascending and descending aortic aneurysms, respectively; the aneurysm grows faster than 10 millimeters in a year; or there is evidence of aortic dissection. Surgical repair involves substituting a graft for the diseased section of aorta. Outcomes following surgery reveal the problematic nature of this disease. The one-month mortality rate is at least 10 percent (greater than 40 percent if the surgery is emergent), stroke rate is 20 percent for ascending aneurysms, and injury rates of the spine and/ or kidneys are 15 percent for descending aneurysms. Patient factors predictive of poor outcome following surgery include symptomatic aneurysms, preoperative kidney disease, older age, and descending aneurysms. Another option for aneurysm repair is endovascular stenting. This new technique is minimally invasive and has been shown to be associated with fewer perioperative complications when compared to surgery. However, long-term follow-up has not yet shown an advantage. Undoubtedly, this technology will continue to improve and one day present a viable option for patients. Brain Aneurysms Cerebral aneurysms are the primary cause of subarachnoid hemorrhage (SAH); therefore, the discussion of one is equivalent to a discussion of the other. Most cerebral aneurysms are of the saccular (berry) type, and the prevalence is estimated to be 5 percent; in other words, 300 million people worldwide have at least one brain aneurysm (approximately one-fourth of patients have two or more). Fortunately, most of these are small enough to be asymptomatic and remain unruptured; aneurysmal SAH occurs at a rate of “only” approximately 12 per 100,000. The average age of cerebral aneurysm rupture is 51 years, and certain risk factors exist that predispose people to aneurysm formation. The most preventable risk factor is cigarette smoking, which increases the risk of aneurysm formation by 2.5 to 5 times compared to nonsmokers. This relationship is also dose dependent, so the more one smokes, the greater risk one has of developing a brain aneurysm. Other strong risk factors include a family history, which increases the risk by four times; hypertension, which increases the risk by 2.5 times; and alcohol, which increases the risk by a factor of 1.5 to 2. Genetics, the medication phenylpro-
panolamine, and estrogen deficiency are also thought to play a role in the development of aneurysms. Aneurysms of the brain cause symptoms in two circumstances: if it is large enough or if it ruptures. The major symptom of a ruptured aneurysm is a headache, usually described as “the worst headache of my life.” Other symptoms include loss of consciousness, nausea and vomiting, seizures, and even low back pain. A finding on physical examination, aside from potential neurologic deficits, is retinal hemorrhages. The most useful tool in diagnosing SAH is a head CT scan without contrast. If the head CT scan is normal, it may have missed the SAH, so a lumbar puncture may contribute to the diagnosis if there is an elevated opening pressure or red blood cell count in the cerebrospinal fluid (CSF). Other diagnostic tools include cerebral angiography and MRI. Treating cerebral aneurysms can be performed with surgery or with endovascular techniques, but only one-third of patients will have favorable results. Surgical intervention is also known as aneurysm “clipping.” In this procedure, the patient receives a craniotomy which allows the neurosurgeon access to the aneurysm. Then, the neurosurgeon places a titanium clip at the base of the aneurysm. This occludes blood flow into the aneurysm and prevents or controls bleeding for unruptured or ruptured aneurysms, respectively. The endovascular treatment of brain aneurysms, also known as “coiling,” is a minimally invasive technique where the neurosurgeon or interventional radiologist enters the patient’s circulatory system through a peripheral vessel and thereby gains access to the cerebral vasculature. Using real-time radiologic imaging, the aneurysm is located and a thin, flexible, wiry material is injected into it until the aneurysm is filled with coils. This also occludes the aneurysm, preventing blood flow and consequent rupture. The complications following SAH are many. The most important one is death. The fatality rate following SAH is 50 percent, with 10 percent of patients dying before reaching the hospital, another 15 percent dying within one day, and another 20 percent dying within one month. Other complications include increased intracranial pressure (ICP) (55 percent of patients), cerebral infarction (50 percent of survivors), vasospasm (34 percent of patients), cardiac dysfunction (20 percent of patients), hydrocephalus (15 percent of
Angina
patients), seizures (7 percent of patients), rebleeding (7 percent of patients), and hyponatremia, all of which may lead to death. Vasospasm, also known as delayed ischemic neurologic deficit, is the leading cause of morbidity and mortality following aneurysm rupture and affects one-third of patients with SAH. The pathogenesis of vasospasm is fascinating: When an aneurysm ruptures, blood comes into contact with the periadventitial space of the blood vessel, resulting in an upregulation of inflammatory cell mediators on the blood vessel wall as well as on circulating white blood cells. As a result, the white blood cells stick to the blood vessel wall and migrate through it, becoming entrapped in the subarachnoid space. This causes vasospasm in two ways. First, white blood cells are a source of endothelins, which are potent vasoconstrictors. Second, as the white blood cells die they release oxygen free radicals, which work to destroy the vasodilator nitric oxide (NO) that is normally released by the blood vessel wall. Patients with vasospasm present with symptoms of altered mental status and/or focal neurologic deficit (i.e., weakness, hemiparesis) anytime between the third and twentieth day following aneurysm rupture, although most commonly it occurs between the sixth and eighth day. Transcranial doppler (TCD) studies can be used to detect vasospasm, although the tool is of low specificity and is particularly unhelpful in elderly patients, who have diminished vasomotor reactivity. The primary treatment and prevention of vasospasm involves hyperdynamic therapy (also known as triple-H therapy: hemodilution, hypertension, and hypervolemia). As mentioned, cerebral infarction (i.e., strokes) occurs in half of SAH survivors; the most common cause is vasospasm. Ten percent of all strokes are due to SAH. Cardiac dysfunction is due to inadequate blood flow to the hypothalamus, which results in an increase in hormone release within the heart and consequent injury. These changes are evident on electrocardiography (EKG). Hyponatremia is caused by injury to the hypothalamus and the syndrome of inappropriate antidiuretic hormone (SIADH) secretion. Screening for cerebral aneurysms is useful only in four select populations. First, patients with two or more first-degree relatives with aneurysms should receive screening. So should patients with autoso-
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mal dominant polycystic kidney disease who have a personal or family history of aneurysm rupture, symptoms, a high-risk occupation, and/or an upcoming surgical procedure. Third, patients with glucocorticoid-remediable aldosteronism should receive screening as these patients have a higher incidence of aneurysms. Last, patients with connective-tissue diseases such as Ehlers-Danlos syndrome or pseudoxanthoma elasticum should also receive screening. Screening involves the use of MRA or computed tomography angiography (CTA). Patients selected for screening will need annual imaging done for the first three years; if these studies are normal, screening can be decreased in frequency to once every five years. SEE ALSO: Cholesterol; Ehlers-Danlos Syndrome; High
Blood Pressure; Marfan Syndrome; Smoking.
Bibliography. Keith D. Calligaro, Matthew J. Dougherty,
and Larry H. Hollier, Diagnosis and Treatment of Aortic and Peripheral Arterial Aneurysms (Saunders, 1999); Michael Forsting, Intracranial Vascular Malformations and Aneurysms: From Diagnostic Work-Up to Endovascular Therapy (Springer, 2004); George E. Pierce, Abdominal Aortic Aneurysms (Saunders, 1989); Sanjay Rajagopalan, et al., Peripheral Vascular Disease (Saunders, 2002); Tatsuzo Tanabe, Aortic Aneurysms: Pathophysiology, Diagnosis, and Treatment (Hokkaido University School of Medicine, 1993); James S.T. Yao and William H. Pearce, Aneurysms: New Findings and Treatments (Appleton & Lange, 1994). Khoi D. Than, M.D. Johns Hopkins University
Angina Angina is the term for the chest pain or discomfort that occurs when cardiac muscle does not receive adequate blood flow. This is usually caused by the buildup of fat and cholesterol within the coronary arteries, and can therefore be considered a sign of heart disease. The three main types of angina are stable angina, unstable angina, and Prinzmetal’s angina. Each causes the same type of pain but occurs in a different pattern and under different circumstances. Individuals with angina should eliminate modifiable
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risk factors, such as cigarette smoking, hypertension, high cholesterol, and poorly managed diabetes mellitus to prevent a worsening of their heart disease. Physicians may also recommend medications or surgery to manage angina. The most common cause of angina is coronary atherosclerosis, or the accumulation of fat and cholesterol that forms stiff plaques within the coronary arteries. Narrowing of the coronary arteries by fatty plaques can limit the amount of blood flow that reaches the heart. Because blood supplies oxygen to body tissues, an increase in cardiac work or a temporary decrease in blood flow through the coronary arteries in someone with coronary atherosclerosis can prevent the heart from receiving enough oxygen. Myocardial ischemia, or inadequate oxygenation of the heart, causes the symptom known as angina. Individuals describe this chest pain as pressure, tightness, or tingling in the center of the chest that sometimes radiates to the neck, jaw, shoulders, arms, wrists, or upper abdomen. Pain usually lasts less than 15 minutes and can vary in intensity. Stable angina is sometimes called demand angina because it occurs when oxygen supply does not meet cardiac demand. Cardiac oxygen demand increases with physical activity or emotional stress. When an increase in oxygen demand cannot be met with an increase in blood flow due to narrowing of the coronary arteries, pain occurs in a predictable, reproducible manner and subsides once the demand decreases. Unstable angina is pain that occurs at rest, with lower levels of physical activity or with increasing frequency than it did when an individual was said to have stable angina. Individuals with new-onset chest pain are also included in this group. Unstable angina is caused by a temporary reduction in cardiac oxygen supply that is not caused by an increase in physical activity. Decreases in coronary blood flow are caused by blood clots that form within coronary arteries and adhere temporarily to plaques. The clots, in turn, may release vasoconstrictors that induce spasms of the blood vessel and further decrease blood flow. Although the clots rapidly dissolve on their own, unstable angina is a worrisome symptom because without treatment, individuals often go on to have a heart attack later in life. Prinzmetal’s angina, also known as vasospastic angina, is chest pain that occurs at rest without
a decrease in cardiac exercise capacity. Myocardial ischemia is caused by coronary artery spasms in individuals with underlying coronary atherosclerosis. Some individuals go on to have a heart attack within three months of diagnosis, but spontaneous remission eventually occurs in most. There are a number of ways to manage angina, including habit modification, medication, and in severe cases, surgical cardiac revascularization. Many individuals are able to control their angina through smoking cessation, weight loss, stress management, exercise, and proper control of hypertension, high cholesterol, and diabetes mellitus. Others may also require medications that decrease cardiac workload and lower oxygen demand (beta-adrenergic blocking agents and calcium channel blocking agents) or those that increase coronary blood flow by dilating the vessels (short- and long-acting nitrates). Individuals with severe coronary atherosclerosis may need to undergo surgical revascularization to restore adequate blood flow to the heart. This can be done through procedures called coronary artery bypass grafting (CABG), balloon angioplasty, or cardiac stenting. SEE ALSO: Angioplasty; Arteriosclerosis; Coronary Dis-
ease; Exercise Treadmill Test; Heart Attack; Heart Bypass Surgery. Bibliography. J. Willis Hurst and Douglas C. Morris,
Chest Pain (Futura, 2001); John Parker, “Angina Pectoris: A Review of Current and Emerging Therapies,” The American Journal of Managed Care (v.10/11 Suppl., 2004). Celina Martinez, M.D. Johns Hopkins University
Angioplasty The word angioplasty comes from the Greek roots angio, which means vessel, and plasticos, which means molding. It is sometimes referred to as Dottering, after Dr. C.T. Dottering, who with Dr. M.P. Judkins was the first to describe angioplasty without a balloon in 1964. In medical practice, angioplasty is the invasive widening of vessels that often are closed
An angiogram—a form of x-ray—is performed to diagnose blockages (occlusions) or narrowings (stenosis) in arteries.
off or narrowed. The most common reason for the narrowing of vessels is atherosclerosis. This decrease in the cross-sectional area of the lumen of the artery decreases blood flow to vital organs and can cause ischemic damage. Typically, angioplasty is performed under local anesthesia by inserting a wire through the skin and into the lumen of an artery beyond the blockage. Over the wire, a balloon catheter is passed to the area of the vessel that is occluded, then hydraulically inflated. This compresses the atheromatous plaque in the wall of the artery and dilates the vessel, thus restoring blood flow to the distal segment. In some cases, a stent (mesh tube) is left behind to support the walls of the vessel and prevent reclosure. Angioplasty with stent placement has been shown to be superior to angioplasty alone in keeping arteries open. When a stent is used, in two out of 10 people the artery will close again within the first six months. When a stent is not used, in four out of 10 people the artery will close again within the first six months. Some newer stents are coated with drugs that prevent restenosis of the artery. These drugs include sirolimus, everolimus, and paclitaxel. Most patients receiving angioplasty will need to take medication for the rest of their lives to prevent platelets in the blood from forming clots due to stent placement. These drugs include clopidogrel and/
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or aspirin. Also, patients will need to carry a stent placement card to alert healthcare workers to the presence of the device. The most common arteries that receive angioplasty are the coronary, renal, and carotid arteries. Less commonly, angioplasty is done on peripheral arteries and narrowed veins. Percutaneous transluminal coronary angioplasty (PTCA) was first performed by Dr. Andreas Gruentzig in 1977. In recent years, PTCA has become favored over coronary artery bypass grafting (CABG) in treating myocardial ischemia due to coronary artery stenosis. This is typically done by threading a catheter through the groin into the femoral artery, thus allowing access to the coronary arteries. Although PTCA has been associated with increased likelihood of recurrent angina and the need for repeated procedures, it is still the treatment of choice for revascularization, as it makes surgery unnecessary. Similarly, angioplasty has replaced carotid endartectomies and renal endartectomies making surgery unnecessary in the setting of carotid stenosis and renal artery stenosis, respectively. Angioplasty is a relatively safe procedure that has become more common in recent years. Risks include restenosis of the occluded artery, bleeding from the catheter insertion site, hematoma formation (pseudo aneurysm), dissection of the artery, allergic reaction to the imaging dye, kidney damage from the dye, heart attack, or stroke. The overall mortality from an angioplasty procedure is approximately 1 percent. The risk for mortality is directly related to the overall health of the patient. SEE ALSO: Angina; Arteriosclerosis; Coronary Disease;
Heart Attack; Heart Bypass Surgery.
Bibliography. Julian M. Aroesty, “Patient Information:
Angina Treatment—Medical versus Interventional Therapy,” UpToDate, patients.uptodate.com (cited October 2006); Clive Handler and Michael Cleman, eds., Classic Papers in Coronary Angioplasty (Springer, 2006); Michel Henry, et al., eds., Angioplasty and Stenting of the Carotid and Supra Aortic Trunks (Informa Healthcare, 2004). Angela Garner University of Missouri–Kansas City Naveen Kukreja University of Missouri–Kansas City
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Angola
Angola Angola is located on the south-central Atlantic coast of Africa and is bordered by the Democratic Republic of the Congo and Zambia. The country is rich in oil, diamonds, and other natural resources. A Portuguese colony from the 1600s until 1975, Angola is nominally a democratic republic, but the country has seen little peace or security. The civil war that broke out upon independence lasted for nearly 30 years and killed an estimated 1.5 million Angolans. Another 4 million were displaced by the fighting. Angola’s population is estimated at 12.1 million (2006), with the population growing at 2.45 percent annually. Life expectancy at birth is an abysmal 37.47 years for men and 39.83 years for women. Infant mortality is 185 deaths per 1,000 live births. Maternal mortality is 1,700 per 100,000 live births. Poverty is rampant, with most of the population living on less than $ 1 per day. Chronic malnutrition affects 40 to 50 percent of the population. Although there are 90 different ethnicities in Angola, most of the population belongs to three main Bantu-language groups: the Ovimbundu (37 percent of the population), the Mbundu (25 percent), and the Bakongo (13 percent). Two percent of the population are mestiços, or of mixed white and African heritage, and 1 percent is white, most of them Portuguese who decided to stay after independence in 1975. The dominant religion is Roman Catholic, with several evangelical groups making inroads in recent years. Many Angolans also follow the indigenous religions and beliefs of their tribes. Angola has a land area of 772,954 square miles (about twice the size of Texas) and has a 1,000-milelong coastline on the Atlantic Ocean. The major geographic features are a narrow coastal plain that rises quickly to a high interior plateau. Lying close to the equator, Angola has a typically tropical climate, with a dry, cool season followed by a lengthy hot, rainy season. Rainfall in northeastern regions can average 59 inches a year. Flooding is common on the plateau. Prior to the civil war, Angola was able to meet its own food needs, and even export a surplus. Today, only 2.65 percent of the land is arable and overuse has depleted soil quality. A large percentage of the population faces food insecurity. Deforestation of the
rainforest has led to the loss of biodiversity and desertification; soil erosion has caused buildup of silt in major waterways. Most of the country suffers from a lack of potable water. Poor sanitation, lack of clean water, and inadequate food supplies leave Angolans at high risk for a variety of bacterial and viral diseases, including diarrhea, hepatitis A, typhoid fever, malaria, African trypanosomiasis (also called sleeping sickness), meningococcal meningitis, yellow fever, leprosy, and schistosomaisis. In spring 2005, Angola suffered a severe outbreak of the Marburg virus, a hemorrhagic fever closely related to Ebola. Medical officials recorded 237 deaths from 261 reported cases before it was brought under control. In spring 2006, the country suffered its first cholera outbreak in more than a decade, and programs are underway to control the reemergence of the disease. Angola has so far been spared the brunt of the AIDS epidemic ravaging Africa. In 2003 the infection rate was about 4 percent, with an estimated 250,000 Angolans living with AIDS, and 21,000 AIDS-related deaths. However, the figure is expected to climb, and within a few years, health officials believe up to 20 percent of the population could be infected. Landmines remain a devastating reminder of the war years, and Angola has one of the highest per capita rates of landmine injuries in the world. Estimates of the number of landmines still hidden under the soil range from six to 20 million. More than 75,000 Angolans (at least 10,000 of them children) have lost a limb to landmines. New injuries are estimated at 150 per week. There are fewer than 50 hospitals in Angola, almost all of them located in the urban areas. The long civil war destroyed much of the country’s infrastructure and road system, making it difficult to get medical supplies and personnel into the rural areas. In the 1980s, the government claimed more than 700 health posts and 140 regional health centers, but the quality of care available was deemed to be low even by African standards. Since the end of the war, international health agencies have poured in to fill the healthcare gap. Still, the World Health Organization says there are only five physicians for every 100,000 people, and 60 to 70 percent of the population have no access to the most rudimentary healthcare. SEE ALSO: Healthcare, Africa.
Anorexia Nervosa
Bibliography. Central Intelligence Agency, “Angola,”
World Fact Book, www.cia.gov (cited March 2007); Adam Mynott, “Angola’s Landmine Legacy,” BBC News (November 29, 2004), news.bbc.co.uk (cited March 2007); United Nations Children’s Education Fund, “Angola— Statistics,” www.unicef.org/angola (cited March 2007); World Health Organization, “WHO Angola,” www.who .int (cited March 2007). Heather K. Michon Independent Scholar
Anorexia Nervosa Anorexia nervosa (AN) is a severe psychiatric illness primarily characterized by a refusal to maintain a minimally normal body weight for age and height. The term anorexia originates from the Greek word orexis, meaning appetite. Therefore, anorexia nervosa translates literally as a “nervous loss of appetite.” Clinical descriptions of AN emerged in the medical literature in the 1870s when it was described by both Ernest-Charles Lasègue and Sir William Gull. Although it is a serious illness, AN affects a small percentage of the population. Evidence from epidemiological studies indicates that the lifetime prevalence rate for AN is approximately 1 percent in the female population, while rates for men range between one-tenth and one-third of the rates for women. The full range of symptoms necessary to diagnose AN are detailed in the fourth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV). The first diagnostic criterion is a refusal to maintain a minimally normal body weight. DSM-IV suggests a guideline of weight loss below 85 percent of expected body weight. However, the International Classification of Mental and Behavioral Disorders, 10th edition, stipulates a more stringent weight threshold of a body mass index of 17.5 kg/m2 to diagnose AN. The use of varying weight criterion has generally led clinicians to diagnose a patient’s low weight status in relation to age, weight history, and weight at which menses regularly occurs. It is the refusal to maintain a normal weight that distinguishes AN from bulimia nervosa, the other main eating disorder described in DSM-IV.
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Beyond an obstinate pursuit of thinness, the second diagnostic criterion for individuals with AN is an intense fear of gaining weight or becoming fat, despite being underweight. To be diagnosed with AN, an individual must also experience the third criterion, which is a distorted perception of body shape or weight, an excessive influence of shape and weight on self-evaluation or denial of the seriousness of being underweight. Because many patients with AN often have extremely ambivalent feelings about seeking treatment, they may deny a fear of weight gain even though this denial is incongruent with their overt behaviors to avoid weight gain. The final diagnostic criterion for AN is amenorrhea, signified by the absence of at least three consecutive menstrual cycles in postmenarcheal females. The current utility of this diagnostic criterion is debatable because research has found few differences between individuals with AN who menstruate regularly and those with amenorrhea. While it may not be a useful diagnostic distinction, it remains an important physiological indicator of possible hypothalamic disturbances, osteoporosis, and/or infertility. Once the diagnosis of AN has been reached, it may be further classified into two distinct subtypes. The restricting subtype captures those individuals who employ weight loss strategies such as calorie restriction, fasting, or excessive exercise. Individuals with AN who engage in behaviors such as binge eating and/or purging via self-induced vomiting or the abuse of laxatives, enemas, or diuretics are classified as binge/purge subtype. Individuals who fall into the latter category tend to exhibit more impulsive behaviors such as self-mutilation, suicide attempts, stealing, or alcohol and/or substance abuse. AN is often accompanied by a number of physical signs and symptoms, usually stemming from starvation or binge eating and purging. These physical symptoms may include gastrointestinal and cardiovascular problems, cold intolerance, and lethargy. The disorder is also frequently accompanied by other psychopathology, particularly depression and anxiety. The causes of AN are varied and include both genetic and environmental risk factors. AN has a typical age of onset in adolescence or early adulthood. Overall, approximately 40 percent of individuals with AN recover, 30 percent improve, and 20 percent remain chronically ill, with mortality rates between 10 to 20 percent due to medical problems related to starvation or suicide.
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Current treatments for AN involve behavioral programs to normalize weight, usually within structured inpatient settings, and cognitive-behavioral therapy to address disturbed eating behaviors and maladaptive cognitions for relapse prevention. A family-based therapy approach, known as the Maudsley method, has the best empirical support for treating adolescents with this illness. The use of antidepressant medication in treating AN during either the acute or recovery stages has not proven beneficial. SEE ALSO: Bulimia; Dieting; Eating Disorders. Bibliography. Christopher Fairburn and Kelly Brownell,
Eating Disorders and Obesity. A Comprehensive Handbook (Guilford Press, 2002); Diane Klein and B. Timothy Walsh, Eating Disorders (International Review of Psychiatry, 2003). Christina Roberto Yale University
Anthrax Anthrax (Bacillus anthracis) gets its name from the Greek word for coal (anthrakis) due to the black skin lesions the disease causes. Anthrax has appeared throughout history; Virgil describes it among domesticated wild animals in his Georgics (29 b.c.e.). It was also the first disease of microbial origin identified by Robert Koch (1876). The first new form of anthrax, inhalation anthrax, occurred among wool sorters in England and may have been the first occupational respiratory disease. In 1979, anthrax spores were accidentally released from a military research facility in Sverdlovsk, Russia, resulting in many deaths. The 2001 postal anthrax attack in the United States showed that anthrax could be used as a bioterrorism weapon. B. anthracis is a large, aerobic, gram-positive, spore-forming, nonmotile Bacillus species. Spores grow readily on all ordinary lab media at 37 degrees C and are shaped like a “jointed bamboo rod” or a “curled hair.” B. anthracis forms a prominent capsule in tissue in vivo and in vitro in the presence of bicarbonate and carbon dioxide. Germination occurs when the bacillus is exposed to an environment rich in amino acids,
nucleosides, and glucose. However, spore formation (sporulation) will occur when the infected body is opened and exposed to air. These spores can survive for decades in ambient conditions. Anthrax is a zoonotic disease that predominantly occurs in domesticated and wild animals. Contact with infected animals or animal products can result in human infection. There are three main forms of anthrax infection: inhalation, cutaneous, and gastrointestinal. Other forms of anthrax infection include meningococcal and oropharyngeal. Natural infection occurs predominantly by the cutaneous route. Inhalation anthrax occurs when spores are breathed in. It is the most lethal form, with mortality greater than 80 percent. The spores must be 1–2 µ in length for them to stay in the lungs. Spores that are greater than 5 µ in size pose a minimal threat to the lungs because they are either trapped in the nasopharynx or cleared by the mucociliary escalator system. Cutaneous anthrax infection occurs when spores enter the body through an abrasion on the skin. This may occur when handling animal hides, wool, leather, or even hair from infected animals. With proper therapy, death is rare for this form. Gastrointestinal anthrax follows consumption of grossly contaminated and undercooked food. This is characterized by acute inflammation of the intestinal tract. Oropharyngeal anthrax is a milder form of gastrointestinal anthrax and has a favorable prognosis. B. anthracis can also cause meningitis. The most common portal of entry is the skin. However, inhalation and gastrointestinal anthrax can also lead to meningitis. These meningococcal cases are almost always fatal. B. anthracis is found worldwide. It is a normal part of the soil flora and can periodically undergo bursts of multiplication that are not well understood. Conditions for multiplication are favorable when the soil has a pH above 6.0, is rich in organic matter, and a dramatic change occurs in the soil environment such as a drought or abundance of rainfall. It is very common for herbivores to be infected while grazing. Epizootic anthrax continues to occur in highly endemic areas such as Iran, Iraq, Turkey, Pakistan, and sub-Saharan Africa. Anthrax reportedly killed over 1 million sheep in Iran in 1945. It is thought that anthrax may be spread from animal to animal by biting flies, and to different environments by vultures and nonbiting flies. Animal vaccination programs have
Antibiotics
helped in some areas. Nevertheless, epizootics still occur. For example, in 2000 over 30 farms in North Dakota were quarantined due to anthrax, and 157 animals died. Anthrax in humans usually occurs following agricultural, horticultural, or industrial exposure to contaminated animals. In the United States from 1900 to 1976, only 18 cases of inhalation anthrax were reported under natural conditions. The cases were related to textiles that were manufactured from imported goat hair. The largest epidemic of inhalation anthrax occurred in Sverdlovsk, Russia, in 1979, where it is believed that there may have been 250 cases, with as many as 100 deaths. Cutaneous anthrax is more common; there were 224 cases reported between 1944 and 1994 in the United States. Outside the United States, the largest epidemic of human anthrax occurred in Zimbabwe, where about 10,000 mostly cutaneous cases were reported. There is little experimental data available to accurately measure the incidence of gastrointestinal anthrax; however, it is still reported in Africa and Asia, mostly resulting from undercooked food. Recently, there have been 22 cases of anthrax in the United States of unnatural (criminal) cause. Clinical presentation of inhalation anthrax begins with a two-stage process. It is believed to start after a one-to-six-day incubation period with nonspecific symptoms. Early symptoms may resemble that of a viral infection, presenting with fever, malaise, fatigue, myalgia, cough, headache, vomiting, chills, and abdominal and chest pain. This stage may last from a few hours to a few days. Some may experience a brief period of recovery. Stage 2 may occur after one to five days of initial symptoms, and is marked by an abrupt onset of high fever, dyspnea, stridor, cynosis, diaphoresis, severe respiratory distress, and shock. Several physiological changes in animal models have been observed, including hypocalcemia, extreme hypoglycemia, hyperkalemia, depression of respiratory centers, hypotension, anoxia, respiratory alkalosis, and terminal acidosis. In these recent cases, lymphadenopathy and enlargement of the mediastinum led to stridor. SEE ALSO: Biodefense; Bioterrorism. Bibliography. Thomas D. Brock, Robert Koch: A Life in
Medicine and Bacteriology (ASM Press, 2000); Barbara Saffer, Diseases and Disorders: Anthrax (Lucent Books, 2004);
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Philipp Sarasin, Anthrax: Bioterror as Fact and Fantasy (Harvard University Press, 2006). Tyler Childs Cymet, D.O. Johns Hopkins School of Medicine
Antibiotics Antibiotics are an important class of anti-microbials used to kill or slow the growth of bacteria. They are specific in nature and their mode of action and therefore do not have any effect against viruses, fungi, or parasites. Fortunately, they are harmless for the host and can be used effectively to manage and treat bacterial infections. Since their accidental discovery in 1929, antibiotics have played a large role in reducing morbidity and mortality of bacterial infections around the world. Antibiotics are considered one of the few successful developments of a “magic bullet” capable of effectively treating a patient with minimal harm to the individual. Although the future effectiveness of antibiotics is in question because of the development of antibiotic resistant bacteria, antibiotics will always be among the most dramatic achievements of modern medicine. Many infectious diseases once considered incurable can now be treated with several pills. The discovery of antibiotics is sometimes said to have happened twice. The earliest discovery was made in 1896 by a French medical student, Ernest Duchesne. As a student, Duchesne found the antibiotic properties of Penicillium but did not make the key connection between the fungus and the substance containing the antibacterial properties. In 1928 Alexander Fleming, a British scientist, discovered the agent that came to be known as penicillin, and he often receives the credit for the discovery of antibiotics. Fleming’s discovery, although important enough to change the course of medicine and the future of mankind, was an accident. The story is that Fleming had returned from a weekend vacation and proceeded to look through sets of old plates that had been left out in the lab. He found that colonies of Staphylococcus bacteria that were streaked out to grow on the plate had lysed. Fleming noted that the bacterial lysis occurred in areas next to contaminated mold that was
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also growing on the plate. He consequently made the connection that the mold was producing an agent capable of causing bacterial cell destruction. The substance found to diffuse across the agar plate from the mold to the bacteria was named penicillin after Penicillium, the mold that produced it. Although Fleming made the discovery of penicillin, the use of the substance in a clinical setting to treat patients was not yet possible. Fleming lacked the ability to purify the large quantities of penicillin needed for a treatment dose. Consequently, he was unable to test the agent’s efficacy in an animal or human host. His work with the substance ended in 1931 with his last published work on penicillin. Almost 10 years later, in 1939, a trio of scientists demonstrated penicillin’s true power in the clinical setting. Howard Florey, Ernst Chain, and Norman Heatley took animals and humans suffering from bacterial infections and in dire condition and cured them with only modest amounts of the drug. Medicine would never be the same. In the early 1940s during the peak of World War II, England and the United States collaborated to increase the production of penicillin. At the time, England had fully committed itself to war in Europe and lacked the capacity to develop penicillin for the masses. To this day, this international cooperation remains a successful example of group collaboration and research in medicine. In its earliest years, penicillin was reserved exclusively for treating soldiers in the war, rather than for general clinical use. A 1942 fire disaster at a Boston nightclub that left many burn victims suffering in area hospitals brought media attention to penicillin. During this time, burn victims were known to die from bacterial infections, such as Staphylococcus. The pharmaceutical company producing penicillin, Merck, forwarded penicillin to Massachusetts General Hospital for the burn victims. The highly publicized success of penicillin in treating the victims launched it into general public use. Types of Antibiotics Antibiotics can be categorized in several different ways based on their target specificity, mode of administration, and mode of action. At the highest level of classification, antibiotics can be classified as acting either with bactericidal or bacteriostatic effects. Bactericidal antibiotics kill bacteria directly. Bacteriostatic
antibiotics kill bacteria indirectly by preventing them from multiplying and relying on the host immune system to destroy them. Another large category distinction can be made based on target specificity. Narrow-spectrum antibiotics target specific types of bacteria, such as Gramnegative or Gram-positive bacteria. On the other hand, wide-spectrum antibiotics affect a much larger range of bacteria and can be used when the source of infection is not entirely known but the speed of treatment is critical. Mode of administration can also be used to classify antibiotics and include the categories of oral, intravenous, or topical antibiotics. While oral administration is the simplest approach, this route is not always effective if the infection is severe. For more serious cases, intravenous antibiotics are used. Depending on the location of the infection, topical applications can be used, as in the case of eye drops or ointments. Antibiotics work through a variety of mechanisms that affect bacteria so that an infection can be resolved in the host. From a pharmacological perspective, the mode of action is a main level by which antibiotics can be classified. These types include antimicrobials that inhibit bacterial cell wall synthesis, inhibitors of protein synthesis, inhibitors of metabolism, and inhibitors of nucleic acid function or synthesis. Through these various mechanisms of attack, bacteria multiplication and their ability to survive can be severely reduced by antibiotics. Depending on the specific bacterial pathogen, an appropriate antibiotic is chosen. In addition, different mechanisms of antibiotic action can be chosen based on whether the bacterial pathogen is resistant to that mode of action. Development of Antibiotic Resistance The powerful effects of antibiotics have been demonstrated all over the world throughout the 20th century. Previously lethal bacterial infections can be treated with a few pills. The reduction in deaths and serious infections has translated into increasing life expectancies in many countries over the past several decades. Although the widespread use of antibiotics has brought about positive changes in countless human lives, their widespread use has also led to one of today’s most pressing medical crises: the emergence of antibiotic resistant organisms. Only within the past decade has the emergence and spread of resistant or-
ganisms come to the forefront of patient care. Physicians and scientists are finding low-cost first-line antibiotics are no longer effective and antibiotics that were reserved for more serious infections need to be given to achieve the same benefit. The change occurring in bacteria around the world is now considered one of medicine’s top priorities. While the global fight against infectious disease was thought to be won with the eradication of smallpox, the reduction in poliomyelitis, and immunization of eight out of 10 of the world’s children against many diseases, a new health crisis looms on the horizon. Antibiotic resistance occurs when bacteria find a way to survive the effects of an antibiotic. This resistance is an evolutionary pressure, providing a survival benefit for select bacteria and therefore making them harder to eliminate. Several diseases, such as tuberculosis, gonorrhea, malaria, and ear infections in children are becoming very difficult to treat in comparison to just a decade ago. In the case of multidrug-resistant tuberculosis, the drugs needed to treat it can cost 100 times more than the first-line drugs of nonresistant tuberculosis. While some countries can afford to pay for this, many countries without such financial benefit can no longer afford to treat multi-drug resistant tuberculosis. Inability to treat due to financial limitations only serves to assist the further spread of the dangerous drug-resistant pathogen. The development of drug resistance in hospital settings further contributes to the growing global problem. Seriously ill hospitalized patients are often given the strongest antibiotics as a matter of necessity and timeliness of treatment. While some pathogens may be destroyed by the antibiotics, it is possible for some to escape and infect another patient in close proximity. Therefore, while the treatment may be beneficial to the individual patient at the time, it becomes yet another opportunity for bacteria to develop resistance in the face of medicine’s strongest antibiotics. The ability to multiply rapidly and transfer resistant genes are two key aspects that make bacteria efficient pathogens capable of resistance. The transfer of resistant genes to other related bacteria happens through the process of “conjugation,” in which plasmids with genes move from one organism to another. Therefore, not only can bacteria pass on resistant genes to their progeny, but they can also rapidly spread it to others in the population.
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There are several factors that encourage the spread of resistant bacteria and that must be addressed by policy if the world is to avert a health crisis. A major preventable cause is the incorrect use and abuse of antibiotics that increase the likelihood of bacterial resistance and subsequent emergence of untreatable bacteria. Misuse occurs when an antibiotic is not taken for the entire prescribed course, is taken at too low a dose, or is used in inappropriate situations, such as to treat a pathogen of nonbacterial origin. Misuse due to failure to take antibiotics for the full course often happens because patients feel better before the end of their prescribed course—before the infecting organism is killed off. In this state, the remaining bacteria can grow tolerant of the antibiotic effects and develop resistance. Other patient-related factors include the belief that new and expensive medications are better than older ones. This misunderstanding drives up healthcare costs and provides bacteria an opportunity to learn how to evade the mechanism of yet another drug. Patients are not the only ones who misuse antibiotics. Healthcare providers may be influenced by the desire to please patients who ask for an antibiotic prescription. While in most cases, with the exception of severe illnesses or other indicating factors, the proper procedure would be to take a culture to determine if the illness is indeed bacterial in nature, this is not currently done. Many people take antibiotics for the wrong reasons: A common example is the prescription and use of antibiotics to resolve viral infections presenting as the common cold. Regardless of the potency of the antibiotic regimen, these drugs cannot eradicate a viral infection, because antibiotics are specific to bacteria. Excessive use of antibiotics as a prophylactic agent for international travelers can also be considered a misuse unless deemed necessary for specific health reasons. Another cause increasing the risk of antibioticresistant bacteria is the use of antibiotics in animals. According to the World Health Organization (WHO), almost 50 percent of all antibiotic production in north America and Europe is given to animals and poultry soon to be used for food production. In general, antibiotics are used as prophylaxis and for growth promotion. Whether the animal is ill with a bacterial infection is not a primary consideration. This setting has shown an increase in resistant bacteria that can spread from animals to humans through
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food. The use of antibiotics in animals for these unrelated health reasons remains a contentious issue in medical, scientific, and agricultural circles.
more efforts are needed and the urgency of addressing bacterial resistance should not be understated.
Antibiotics and the Future of HealthCare A crisis of enormous proportion is brewing in the form of antibiotic resistant pathogens. Once-treatable infectious diseases may provide medicine with a challenge just as great as that before the discovery of antibiotics in the early 20th century. Like the collaborative efforts of the United States and Britain to produce the first antibiotics in mass quantities, collaboration is needed if medicine and science are to tackle drug-resistant bacteria. Partnerships between WHO, the United Nations, and industrialized countries with the resources for modern medical research will need to be fortified to prevent a global health crisis. Fortunately, attempts have already been made to address the emergence and spread of antibiotic-resistant pathogens. In 2001, WHO initiated the first global strategy, which is known as the WHO Global Strategy for the Containment of Antimicrobial Resistance. First, this plan acknowledges that resistance to antibiotics is a worldwide problem and is not limited to certain countries. The plan then outlines steps countries need to take to reduce and slow the emergence of resistant bacteria from several perspectives within the healthcare system. Such steps include educational campaigns for prescribers of medication to ensure the appropriate use of medication to treat bacterial infections. WHO has also produced a Model List of Essential Drugs designed to assist governments and ministries of health around the world to understand which antibiotics are the most appropriate for specific pathogens when a choice arises between the most effective drug and the drug most useful in avoiding further bacterial resistance in the region. The goal of the list is to enable providers in entire countries to use drugs in a rational and appropriate way. Since the list was developed in 1977, countries that participate have been found to reduce their utilization of antibiotics, have more reserve drugs available for severe cases, and have drug stocks that last longer, thus reducing overall costs. Such efforts on a global scale are only the beginning and are crucial to safeguarding humanity’s vulnerability to antibiotic resistant bacteria. Still,
trol and Prevention (CDC); Disease Prevention; Food and Drug Administration (FDA); Foodborne Diseases; Generic Drug; Infectious Diseases (General); Pharmaceutical Industry (Worldwide); Pharmacologist; Pharmacology; Prescription Drugs Abuse; Viral Infections.
SEE ALSO: Bacterial Infections; Centers for Disease Con-
BIBLIOGRAPHY. Paul H. Axelsen, Essentials of Antimicro-
bial Pharmacology: A Guide of Fundamentals for Practice (Humana Press, 2001); Centers for Disease Control and Prevention, “Get Smart: Know When Antibiotics Work,” www.cdc.gov (cited October 2006); Stuart B. Levy, The Antibiotic Paradox: How the Misuse of Antibiotics Destroys Their Curative Powers (HarperCollins Publishers, 2002); National Institutes of Health National Institute of Allergy and Infectious Disease, “The Problem of Antimicrobial Resistance,” www.niaid.nih.gov (cited October 2006); Christopher Walsh, Antibiotics: Actions, Origins, Resistance (ASM Press, 2003); World Health Organization, “Antimicrobial Resistance,” www.who.int (cited October 2006). Jonathan Tan SUNY Stony Brook School of Medicine
Antigua and Barbuda The Caribbean islands of Antigua and Barbuda have been having economic difficulties after a decline in tourism that began in 2000. Commitment to public health has suffered, even though the government announced in 1994 that it was committed to guaranteeing health as a human right and launched a multiyear program designed to improve access to healthcare. With a per capita income of $10,900, Antigua and Barbuda rank 85 out of 233 countries in world income. Some 82 percent of the labor force are engaged in service industries, mostly tourism, and unemployment now stands at 11 percent. The unofficial poverty rate is 12 percent, and the bulk of those living below the poverty line are mothers with dependent children. Important data on many social indicators are unavailable, making analysis of general health somewhat difficult.
Antioxidants
While only 3.8 percent of the labor force is involved in agriculture, this sector is extremely important to the overall health of islanders because local farmers sell chiefly to the domestic market. Agriculture on the islands is vulnerable to the hurricanes and tropical storms that occur between July and October and to periodic droughts. Most islanders (85.8 percent) over the age of 15 are able to read and write. The United Nations Development Programme (UNDP) Development Reports rank Antigua and Barbuda 59th of 177 countries on overall quality-of-life issues. While 95 percent of the urban population has access to safe drinking water, that number drops to 89 percent in rural areas. Likewise, 94 percent of the rural population has access to improved sanitation compared to 98 percent of urban residents. The government spends 4.5 percent of its Gross Domestic Product (GDP) on healthcare, and allots $443 (international dollars) per capita for healthcare expenditures. Government spending accounts for 70.6 percent of total health expenditures, but none of that is directed toward providing social security. Almost 30 percent of healthcare costs are derived from private sources, and virtually all of those are out-of-pocket expenditures. Access to health professionals on Antigua and Barbuda is somewhat limited because there are only 0.17 physicians and 3.28 nurses per 10,000/ population on the islands. Antigua and Barbuda’s population of 69,108 experiences a life expectancy of 72.16 years, earning the islands a ranking of 118th in world life expectancy. At 2.24 children per female, the fertility rate is also in the mid-range. Approximately 53 percent of island females use some method of birth control. All births are attended by skilled personnel, and all women receive prenatal care. The maternal mortality rate is 65 deaths per 100,000 live births. The infant mortality rate on the islands is 18.86 deaths per 1,000 live births, and male infants (22.71) are particularly vulnerable compared to females (14.82). The under-5 mortality rate is 12 deaths per 1,000 live births. Eight percent of island infants are underweight at birth. Around 10 percent of children under the age of 5 are malnourished, and 4 percent are severely underweight. Some 10 percent of the under-5 population suffer from wasting diseases, and 7 percent of this age group experience growth stunting. The government subsidizes 100 percent of the re-
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quired vaccines for small children. As a result, 91 percent of all children are immunized against diphtheria, pertussis, and tetanus (DPT1), and 97 percent receive the DPT3, polio, measles, hepatitis B, and Haemophilus influenzae type B (Hib3) vaccines. HIV/AIDS is a growing problem in the Caribbean, and more than 3,500 cases were reported in the area in the early 1990s. The rate in Antigua and Barbados remains comparatively low, with only 41 cases reported. Cancer is the leading cause of death on the islands, followed by cerebrovascular and heart diseases, hypertensive diseases, and diabetes mellitus. See also: Barbados; Dominica; Grenada. Bibliography. Jacqueline Anne Braveboy-Wagner and
Dennis J. Gayle, Caribbean Public Policy: Regional, Cultural, and Socioeconomic Issues for the Twenty-First Century (Westview, 1997); Central Intelligence Agency, “Antigua and Barbuda,” World Factbook, www.cia.gov (cited January 2007); Chandra Hardy, The Caribbean Development Bank (Lynne Rienner, 1995); Franklin W. Knight and Teresita Martinez-Vergne, eds., Contemporary Caribbean Cultures and Societies in a Global Context (University of North Carolina Press, 2005); Pan American Health Organization, “Antigua and Barbuda,” www.paho.org (cited January 2007); United Nations, “Antigua and Barbuda,” unstats. un.org (cited January 2007); United Nations Children’s Fund, “Antigua and Barbuda,” www.unicef.org (cited January 2007); World Bank, “Antigua and Barbuda Data Profile,” devdata.worldbank.org (cited January 2007); World Health Organization, “Antigua and Barbuda,” www.who.int (cited January 2007). Elizabeth Purdy, Ph.D. Independent Scholar
Antioxidants Antioxidants are compounds used by the body to keep cells from being damaged by the oxidative stress of chemical reactions. The by-products of these oxidation reactions, free radicals, are the main cause of harmful chain reactions and are therefore removed or reduced by antioxidants. These compounds work simultaneously in complex systems and can be made
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in the body or obtained through dietary means. These molecules have proved to be quite effective in treating various diseases because they offer basic protection to cells throughout the body. However, some say that improper use could cause an antinutritional effect. The exact mechanisms and amount needed has not been completely determined. Oxidation is a basic and ubiquitous process in the body whereby electrons are transferred from one compound to another. During this process, charged molecules called free radicals are formed. Oxidative stress is a result of unnecessary reactive oxygen species (ROS) being formed with charged oxygen molecules. Because cells cannot survive in a continuous oxidized state, antioxidants are used to counteract this process and help the cell return to chemical equilibrium. Antioxidants can be compounds made by the body or can be acquired through dietary supplementation. In the body, these endogenous and exogenous antioxidants work together to reduce or prevent oxidative cell damage when needed. The major compounds of dietary antioxidants include vitamin A, vitamin C, vitamin E, selenium, and plant-derived chemicals. Recommended dietary sources include vegetables, fruits, tea, cocoa, wine, nuts, low-fat dairy products, and cereal grains. Dietary antioxidants seem to have a vital role in reducing the chance or preventing the onset of various conditions such as cancer, heart disease, cognitive impairment, and eye diseases. The free radicals generated by the body seem to play a role in the natural aging process and aging seems to contribute to health problems due to the resulting oxidative stress. A highfiber vegetarian diet with an assortment of vegetables and fruits seems to significantly reduce the incidence of cancer in general. Due to the complex composition of most fruits and vegetables, researchers have not been able to conclusively link an antioxidant-rich diet to decrease in cancer incidence. However, vitamin C was shown to have the strongest protective effect against stomach cancer and vitamin E showed some tumor-suppressing capabilities in animal studies. In the case of heart disease, research has shown that intake of several different antioxidant vitamins could provide a protective effect against the oxidation of low-density lipoprotein (LDL) cholesterol, which leads to clogged arteries. Preventing this clogging could significantly lower the chance of getting a heart attack.
Also, vitamin E in particular can potentially be used to reverse or prevent neurological diseases such as Alzheimer’s and Parkinson’s. Finally, the eye is a place for high levels of oxidation due to intense exposure to light. Antioxidants have been shown to neutralize such by-products that accumulate over time. In specific circumstances, antioxidants create an undesirable effect on health. One trial showed that beta-carotene, a form of vitamin A, increased the risk of lung cancer in smokers. After exercising, free radicals are produced by the immune system to repair damaged tissue and excess antioxidant levels could potentially hinder this process. While we lack a complete understanding of antioxidants’ role in the body or in pharmacologic treatment, it is certain that they are an essential part of health. SEE ALSO: Biochemistry; Disease Prevention; Nutrition;
Vitamin and Mineral Supplements.
Bibliography. International Food Information Council
Foundation, “Functional Foods Fact Sheet: Antioxidants,” www.ific.org (cited May 2007); Andreas M. Papas, Antioxidant Status, Diet, Nutrition and Health (CRC Press, 1999). Angela Garner, M.D. University of Missouri–Kansas City Viswanatha Lanka University of Missouri–Kansas City
Anxiety Disorders While anxiety helps humans survive day-to-day experiences and prepares the body to face threats and danger, obsessive anxieties and fears serve negative functions by maintaining the stressful state and preventing normal and healthy relaxation. When this phenomenon occurs, anxiety disorders, a group of behavior abnormalities characterized by feelings of doom and excessive fear, may develop. Throughout the industrialized world, billions of dollars are spent each year in providing treatment for anxiety disorders. Many individuals, however, never seek professional help in dealing with these conditions despite major reductions in quality of life. In the United
States, the medical cost of treating anxiety disorders is twice that spent on other medical conditions, even among populations who are ill. Medications used in treatment of these disorders are among the most widely used drugs in the world. Both white and black Americans exhibit similar patterns of anxiety disorders. However, African Americans are more likely to suffer from hypertension, which has been associated with anxiety disorders. Hispanic Americans, particularly from countries of the Caribbean, are prone to ataque de nervios, which is similar to classic panic attacks. Affected individuals may episodically shout uncontrollably or burst into tears. Attempts to use Western treatments for anxiety disorders have generally not been successful in non-Western nations. This is due in part to the fact that Eastern societies tend to look for specific reasons for anxiety disorders that range from work stress to environmental stressors. The assumption is that if those causes are removed, the disorder will vanish. Individuals who suffer from anxiety disorders tend to be tense, worried, unhappy, pessimistic, and unable to separate real from imagined dangers. Anxiety disorders include panic disorder without agoraphobia, panic disorder with agoraphobia, agoraphobia without a history of panic disorder, specific phobias, social phobia, obsessive-compulsive disorder (OCD), post-traumatic stress disorder (PTSD), acute stress disorder, generalized anxiety disorder, anxiety disorder due to a generalized medical condition, substance-induced anxiety disorder, and anxiety disorder not otherwise specified. Research and history Longitudinal studies of both inpatients and outpatients under treatment for anxiety disorders reveal that affected individuals may have a lower than normal life expectancy. Males with anxiety disorders are particularly vulnerable to cardiovascular diseases. In one American study of 33,000 male professionals between the ages of 42 and 77, men who had been diagnosed with anxiety disorders were three times more likely to develop cardiovascular problems than those who did not have the disorder. The study also revealed that deaths among males with anxiety disorders tended to be sudden rather than progressive. A subsequent study found a five times greater risk among males with anxiety disorder, even when other factors associated with
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cardiovascular disease such as family history, smoking, and high blood pressure were controlled. Both males and females with anxiety disorders are at greater risk than the general population for suicide. A fifth of all patients in one study had attempted suicide. Although there is a well-established body of literature on anxiety disorders, the causes of these conditions are not always known. With a great deal of overlapping, anxiety disorders have been regarded as either biological conditions that respond well to medications or as psychological phenomena that call for psychological intervention. Much of the early literature on anxiety disorders derived from the work of Sigmund Freud (1856–1939), the father of psychoanalysis. Freud contended that anxiety neurosis was characterized by excitation consciousness that led to irritability, auditory hypersensitivity, and anxious expectations. He believed that anxiety disorders were a result of a dammed up libido. He later determined that anxiety triggered defensive mechanisms in response to certain conditions or events, rather than the other way around. More recent analysis of anxiety disorders have led to Freudian theories being labeled as “toxic.” By the mid-20th century, theorists had come to the conclusion that anxiety disorders were generally interpersonal in nature. According to a number of studies, most anxiety disorders have onset in childhood. Estimates of how many anxiety disorders become chronic vary from 4.3 to 68 percent. Anxiety disorders in children may exhibit as headaches and stomachaches that have no physical cause. Before 1980, child and adolescent anxiety disorders were not considered age specific. At that time, the American Psychiatric Association created three subcategories designed to deal with disorders in pre-adulthood: separation anxiety, overanxious disorder, and avoidant disorder. Separation anxiety is a natural sign of healthy development in older infants and may continue to some extent in young children. It is classified as a disorder when the condition persists at later ages for more than four weeks and is marked by excessive distress when being separated from home and family, persistent fears that outside forces will separate the child or adolescent from attachment figures, or when he/she refuses to leave the home as a result of obsessive anxiety. Physical conditions associated with separation anxiety include headaches, stomachaches, nausea, vomiting,
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One study found that men diagnosed with anxiety disorders were three times more likely to develop cardiovascular problems.
and nightmares. Overanxious disorder occurs only in older children and adolescents. It is marked by excessive and irrational worrying about events that may take place at some unspecified future time. Avoidant disorder involves refraining from contact with specific phenomena. In 1994 in the Diagnostic and Statistical Manual of Mental Disorders, 3rd edition and 3rd edition revised (DSM-III and DSM-III-R), the American Psychiatric Association (APA) eliminated Anxiety Disorders of Childhood and Adolescent subcategories, leaving only separation anxiety as a child-specific disorder. Panic disorder In 1975, R.L. Spitzer and his colleagues argued that panic disorder and generalized anxiety disorders should be understood as separate disorders. The APA complied in DSM-III. The onset of panic disorder occurs most often between the ages of 25 and 44. Once it has begun, however, it may continue into old age. A joint Harvard–Brown Anxiety Disorder Research Program in the mid-1990s found that within approximately two years of onset of the initial diagnosis, 18 percent of patients who had acrophobia and 23 percent of those who did not had recovered. By contrast, 80 percent of those with major depressive attacks, 22 percent with mood disorders, and 20 percent with schizophrenia had recovered within that same period. While experiencing many of the same symptoms, individuals with panic disorder may experience symptoms with varying degrees of intensity. In some indi-
viduals, panic attacks are chronic rather than episodic. Approximately a quarter of individuals who have panic attacks experience them from one to five times a day. Panic attacks tend to be sudden in onset, and the most common characteristic is the feeling that sufferers are about to die or be faced with some major calamity beyond their control. Other common symptoms of panic attack include expectations of fainting, collapse, losing control, having a heart attack, becoming insane, becoming ill, being unable to get home, making a fool of him/herself, or experiencing memory loss. Panic attacks also have physical manifestations, such as shortness of breath, palpitations, chest pain or discomfort, and choking or smothering sensations. Phobias Persistent and irrational fears of particular objects, activities, and situations that cause a person to refrain from all contact with the source of fear are identified as phobias. Agoraphobia, one of the most often diagnosed phobias, is defined as the fear of being in places and situations where escape is difficult and in which danger or embarrassment is viewed as certain. Popularly, agoraphobia is often referred to as fear of crowds. Whether the disorder is always accompanied by panic disorder or whether it may occur in isolation continues to be debated. Approximately one-third of individuals diagnosed with agoraphobia also exhibit one additional anxiety disorder, and another third exhibit multiple social fears. In extreme cases, individuals who suffer from agoraphobia refuse to leave their homes. Occurrences of agoraphobia with panic disorders are more common in lower socioeconomic status individuals. Phobias associated with particular phenomena are called specific phobias. Fear of animals is one of the most common phobias and is more likely to affect small children and women. Ninety percent of those affected by animal phobias are female. A common animal phobia is ailurophobia, which is fear of cats. Common situational phobias are aerophobia, or fear of flying; fear of heights; and claustrophobia, the fear of enclosed spaces. A common phobia, known in the United States as school phobia and in Britain as school refusal, is characterized by outright refusal by a child to attend school. Behaviors associated with the phobia include refusal to leave the home, limited social functioning, fear of crowds, and avoidance of situations
from which escape is assumed to be difficult. School phobia may manifest physically in nausea, anorexia, vomiting, headache, pallor, abdominal pain, general malaise, and diarrhea. The phobia may develop in the absence of a prior history of anxiety disorders, or it may occur in conjunction with separation anxiety, panic disorder, or social phobia. With a strong genetic link, particularly in females, specific phobias occur in around 30 percent of first-degree relatives of individuals with these disorders. Social phobias occur most often in individuals of high socioeconomic status, and 70 percent of sufferers are female. The mean age onset is 15 years, and life quality tends to be low. The condition may consist solely of an obsessive fear of public speaking, or it may encompass a morbid fear of being made to look ridiculous in front of others that severely limits social interaction. Individuals with severe social phobias have a risk of depression that is three times that of the general population, and are twice as likely to develop alcohol dependency. There is a three- to sixfold higher risk for developing bipolar disorder, and social phobias are also a strong predictor for future development of mood disorders. In addition to being female, other risk factors include the lack of a close relationship with an adult during childhood, not being firstborn, parental marital conflict or rejection, family history of psychiatric problems, and poor school performance. obsessive-Compulsive disorder (OCD) In 65 percent of all cases, obsessive-compulsive disorder surfaces before the age of 25. It is most likely to appear in late adolescence or early adulthood. Although approximately 70 percent of all children who have OCD are male, adult prevalence is roughly equal. By definition, OCD is characterized by behavior that ranges from obsessive cleanliness and organization to fear of any contact with other people or objects because of possible contamination. Other common behaviors include locking and relocking doors, following specific rituals, obsessive counting, and hoarding. OCD often occurs in conjunction with schizophrenia and depressive or mood disorders, social disorders, eating disorders, autism, and Tourette’s syndrome. A large body of literature exists on post-traumatic stress disorder (PTSD) as a result of studies conduct-
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ed on survivors of combat, concentration camps, and natural disasters. Women are more likely than men to experience PTSD, but it occurs in response to different stimuli. Men tend to develop the condition after serving in combat or after witnessing major injuries or deaths. Around half of all women diagnosed with PTSD have developed the disorder in response to a physical attack or rape or to prolonged threats of such attacks. Females below the age of 15 are particularly vulnerable. Although males have no increased risk of experiencing other anxiety disorders, the risk for females is three- to fourfold higher than in the general population. The major predictors for developing PTSD are strong adolescent friendships, a prior history of trauma, a family history of psychiatric disorders, disrupted parental attachments, and the severity of exposure to relevant traumas. Acute stress disorder shares some characteristics with PTSD, but it is more severe and tends to occur within six months of a specific trauma. Acute stress disorder is accompanied by a marked reduction in motor activity and an increase in uncontrolled activity. In the most severe cases, sufferers may revert to infantile passivity in an effort to return to the safest period of their lives. Some individuals try to return to the prenatal condition, reverting to the fetal position and total dependency. During World War II and the Israeli War of Independence, this condition surfaced among the military. Some soldiers exhibited incontinence, abnormal speech, and a variety of infantile behaviors. Acute stress disorder may also be characterized by rationalization in which sufferers look to outside forces such as religion, astrology, and meditation to remove them from immediate danger. Generalized and other anxiety disorders Worldwide, generalized anxiety disorder (GAD) is one of the most common mental disorders. It is more likely to strike women than men. Diagnosis is made after six months of continued behaviors that include constant worry and tension that have no basis in reality. Affected individuals obsess about their health, finances, family problems, and work situations. Anxiety disorder due to a generalized medical condition may be a side effect of conditions such as asthma, chronic obstructive pulmonary disease, congestive heart failure, Cushing’s syndrome, delirium, dementia, epilepsy,
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hypertension, hyperthyroidism, Huntington’s disease, infections, multiple sclerosis, premenstrual syndrome (PMS), and Wilson’s disease. Substance-induced anxiety disorder may be brought on by alcohol and drug abuse or through withdrawal from such substances. Various studies have estimated that from 25 to 45 percent of all individuals with anxiety order are also suffering from substance abuse. All anxiety disorders not included in the preceding categories are included under the umbrella term anxiety disorder not otherwise specified. Culture-specific anxiety disorders Culture may play a significant role in determining phobias. One of the most striking examples of this phenomenon occurred in 1967 among Chinese males living in Singapore. These men developed the phobia known as koro, which is marked by an overwhelming fear that sexual organs are retracting into the abdomen as a prelude to death. Affected males ran screaming for help, but the attacks subsided after a few hours. It was later revealed that many of the affected males were experiencing guilt related to sexual behavior. Although less common in females, koro appears as an obsessive fear of the retraction of the nipples, breasts, or occasionally the labia. Another phobia that is specific to Chinese cultures is pa-leng, an obsessive fear of being cold. This phobia is characterized by cold, clammy hands, tachycardia, and dry mouth. This fear arises out of the Chinese acceptance of the yin and yang theory that is believed to maintain balance within the body. Because affected individuals believe that extreme cold will be a prelude to their deaths, they wear thick layers of clothing in all kinds of weather. Panic disorders are more common in particular cultures. From 60 to 89 percent of Khmer refugees living in the United States, for instance, are subject to a panic disorder that is associated with dizziness and soreness in the neck. The cultural element of the disease is derived from the belief that the most important vessels of the body are found in the limb and necks in order to serve as conduits for wind. Sufferers fear that malfunctions of these vessels will precipitate death. In Iran, a panic disorder identified as “heart distress” results in palpitations. Fright disorders and so-called voodoo death are also culture specific. Among Latin American cultures, susto, which is marked by irrita-
bility, insomnia, and phobia, occurs in response to sudden frights, black magic, or witchcraft. The Japanese identify behavior that would be considered neurotic in Western societies as shinkeishitsu. It is characterized by perfectionism, extreme selfconsciousness, and social phobias. Japanese psychiatrist Shoma Morita has identified three subcategories of shinkeishitsu: obsessive, marked by lack of eye contact, blushing, stuttering, and body odor; neurasthenic, characterized by hypochondria, poor concentration, and shyness; and anxiety states, which are similar to panic attacks. These conditions affect 50 percent, 25 percent, and 10 percent, respectively, of all individuals with anxiety disorders in Japan. Another 10 percent of anxiety disorders fit into none of these subcategories. See also: Adolescent Health; AIDS; American Psycho-
logical Association (APA); Child Mental Health; Depression; Heart Diseases (General); High Blood Pressure; Hormones; Infant and Toddler Development; Mental Health; Psychiatry; Psychology; Smoking; Suicide; World Health Organization (WHO). Bibliography. American Psychiatric Association, Di-
agnostic and Statistical Manual of Mental Disorders: DSM IV (American Psychiatric Association, 1998); Roger Baker, ed., Panic Disorder: Theory, Research, and Therapy (Wiley, 1989); David H. Barlow, Anxiety and Its Disorders: The Nature and Treatment of Anxiety and Panic (Guilford, 2002); Eric J.L. Griez, et al., Anxiety Disorders: An Introduction to Clinical Management and Research (Wiley, 2001); Richard G. Heimberg, et al., Generalized Anxiety Disorder: Advances in Research and Practice (Guilford, 2004); Eric Hollander and Daphne Simeon, Concise Guide to Anxiety Disorders (American Psychiatric Publishing, 2003); Cynthia G. Last, ed., Anxiety across the Lifespan: A Development Perspective (Springer, 1993); National Institutes of Health, “Anxiety Disorders,” www.nimh.nih. gov (cited June 2007); P.W. Ngul, “The Koro Epidemic in Singapore,” Australian and New Zealand Journal of Psychiatry (v.3, 1969); Benjamin A. Root, Understanding Panic and Other Anxiety Disorders (University Press of Mississippi, 2000); William Stewart, Controlling Anxiety: How to Master Fears and Phobias and Start Living with Confidence (Oxford University Press, 1998); Steven Taylor, Anxiety Sensitivity: Theory, Research, and Treatment of the Fear of Anxiety (Erlbaum, 1999); P. Tryer, Anxiety:
Aphasia
A Multidisciplinary Review (Imperial College Press, 1999); Benjamin B. Wolman, ed., Anxiety and Related Disorders: A Handbook (Wiley, 1994). Elizabeth R. Purdy, Ph.D. Independent Scholar
Aphasia Approximately 1 million Americans currently suffer from a relatively unknown condition called aphasia, with 80,000 new cases being diagnosed annually. Aphasia is caused by damage to the brain and consists of an individual’s partial or complete loss of the ability to comprehend language. This condition has a high prevalence among individuals who sustain a stroke; however, it also occurs in individuals, irrespective of age, who have experienced other forms of brain damage (i.e., trauma, hemorrhage, tumor, or infection). The pathophysiology of aphasia varies, necessitating an understanding of the different regions and functions of the brain to determine the type and extent of the condition. In general, the brain consists of two cerebral hemispheres with various regions therein. Overall, the right hemisphere of the brain deals with context, spatial orientation, analytic thought, creativity, and intuition, whereas the left hemisphere handles logic and language. When a person suffers from brain damage to the left hemisphere of the brain, the language capabilities of the person are affected as well as movement in the right side of the body. There are several different types of aphasia, but they are generally characterized as Broca’s aphasia, Wernicke’s aphasia, and global aphasia. Broca’s aphasia is categorized by labored, stilted speech, in which the speaker drops words and can only speak in short sentences. Conversely, Wernicke’s aphasia results in speech that incorporates nonsensical words. Sufferers of Wernicke’s aphasia speak fluently, but the words are awkwardly expressed. Furthermore, such individuals also have difficulty understanding the speech of others. In contrast to other more region-specific aphasia, global aphasia is the most severe type and is noted for damage to the entire hemisphere of the brain, resulting in severe limitations of speech and a general inability to comprehend the language of others.
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The diagnosis of aphasia is performed by the physician in his or her examination of a patient who has sustained a traumatic brain-related episode. Aphasics can have expressive language difficulties, such as problems in speaking, naming, or word repetition. Problems with receptive language, more commonly known as the lack of oral language comprehension, are also symptoms. Other problems related to reading and writing, wordfinding, fragmented speech, motor speech inability that also includes swallowing difficulties, and the inability to make various speech sounds are associated with aphasia. In addition, there are many other conditions that can occur along with aphasia. Many stroke-induced aphasia sufferers can also suffer from some form of paralysis of the body, apraxia (the inability to control speech producing muscles), alexia (the inability to read), or dysgraphia (the inability to write). Approximately eight to nine percent of children have a speech sound disorder, often attributed to sustaining a brain-related injury. Aphasia in children is commonly referred to as acquired childhood aphasia. Another condition in children that results in aphasia is called Landau-Kleffner syndrome (LKS), which is a rare epilepsy syndrome. Symptoms of LKS include difficulties in speech, behavioral problems, and seizures. Because the symptoms of LKS are similar to the symptoms of other conditions, such as autism, attention deficit disorder, or mental retardation, many children with LKS are misdiagnosed. Individuals who become aphasic may develop spontaneous or partial spontaneous recovery. Conversely, recovery over an extended duration is also commonly noted. However, such outcomes are largely determined upon the mechanism and type of brain injury, the extent and region of brain damage, age, overall health, and other personal factors (i.e., socioeconomic status, educational level) that may help predict, but not necessarily dictate, the course of the condition. For example, aphasia acquired through head trauma has been associated with the best prognosis, while the worst prognosis is associated with aphasia caused by damage to both sides of the brain. Moreover, it is believed that the chance for recovery from aphasia in children is greater than that for adults. A speech language therapist is often consulted to assist in the reconstitution of language and to determine other methods of communication
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for the patient. In addition, group and family therapy have been found to be beneficial support structures in developing new communication skills for the individual with aphasia. SEE ALSO: Brain Cancer; Brain Diseases; Brain Injuries;
Speech and Communication Disorders; Stroke.
Bibliography. Antonio R. Damasio, “Aphasia,” New
England Journal of Medicine (v.326, 1992); National Institute on Deafness and Other Communication Disorders, “Aphasia,” www.nidcd.nih.gov (cited October 2006); Michel Rijntjes, “Mechanisms of Recovery in Stroke Patients with Hemiparesis or Aphasia: New Insights, Old Questions and the Meaning of Therapies,” Current Opinion in Neurology (v.19, 2006); Wrong Diagnosis, “Statistics by Country for Aphasia,” www.wrongdiagnosis.com (cited October 2006). Afrodite Skaouris Northeastern Illinois University Dino Samartzis, D.Sc., M.Sc., Dip. EBHC Harvard University and Erasmus University
Appendicitis Appendicitis, sometimes known as epityphlitis, is a condition whereby people suffer from an inflammation of the appendix. Some milder cases can resolve themselves using the body’s natural functions, but most require the removal of the inflamed appendix either by laparotomy or laparoscopy, often leaving a small scar. Essentially, if untreated, the risk of peritonitis, when the inflamed appendix bursts, and shock, is high and death can result. The first person to describe acute appendicitis was Reginald H. Fitz in 1886. His article, “Perforating Inflammation of the Vermiform Appendix with Special Reference to Its Early Diagnosis and Treatment,” was published in the American Journal of Medical Science and led to the recognition that appendicitis is one of the most common causes of trouble in the abdomen for humans around the world. There are a range of causes for appendicitis, which may come from a hard mass of fecal matter, with many people suggesting the swallowing of grape seeds or
similar materials might cause this, from viral induced ulcers, and/or lymphoid hyperplasia. Excessive consumption of alcohol may also exacerbate a case of appendicitis. Doctors try to establish whether a patient may have appendicitis by measuring the number of white blood cells (leukocytes), which often increase from the normal count of between 5,000 and 10,000 (for an adult) to an abnormal count of between 12,000 and 20,000. This takes place because of other acute inflammatory conditions that occur in the abdomen at the same time. Those suffering an attack of appendicitis usually feel pain all over their abdomen or sometimes in their upper abdomen around the area of the navel. The pain is usually not that severe, and for a period of one to six hours after the first pain sensation, the abdominal pain becomes restricted to the lower right side. There may also be nausea and/or vomiting, with patients often developing a fever, although this sometimes happens some hours, or even a day, later. The basic method for treating appendicitis is for a surgeon to completely remove the appendix in a minor operation, regularly performed, called an appendectomy. For this reason, many people have their appendix removed ahead of any trouble. The operation itself, conducted under anesthesia, may be over in as little as 30 minutes. Problems arise if the diagnosis of acute appendicitis is not made straightaway; it is possible for doctors to wait for a while—often as long as 34 hours—so that a more definitive diagnosis can be made. During that time, it is important for the patient to remain in the hospital in case of medical emergencies and/or when the need for surgical intervention arises. Owing to the complications of acute appendicitis and the fact that appendectomy can be performed without side effects, some people planning travels or expeditions, or moving to countries where medical care is not good, may opt for an appendectomy before they leave. In 1950 a crisis arose when Dr. Serge Udovikov needed an appendectomy in the Australian Antarctic Territory. Now, in remote places such as the Mawson Base in the Australian Antarctic Territory (where a case happens on average every two years), it is considered necessary to have a resident doctor capable of performing an appendectomy. SEE ALSO: Surgery; Travel Medicine.
Argentina
Bibliography. D.A. Hale, et al., “Appendectomy: Im-
proving Care through Quality Improvement,” Archives of Surgery (v.132, 1997); T.B. Hugh and T.J. Hugh, “Appendicectomy—Becoming a Rare Event?” Medical Journal of Australia (v.175, 2001); Richard A. Williams and Paul Myers, Pathology of the Appendix (Chapman & Hall Medical Publishers, 1994). Justin Corfield Geelong Grammar School, Australia
Argentina Although Argentina has the potential to offer its population of 39,921,833 a comfortable lifestyle with relatively good health, the country is currently suffering economically. Negative growth and investment skepticism are by-products of inflation, external debt, capital flight, and budget deficits. With a per capita income of $13,700, Argentina ranks 69th of 233 countries in world income. The private sector furnishes 51.4 percent of healthcare costs in Argentina, and 55.6 percent of that amount is out-of-pocket expenses. Workers’ unions continue to play an important role in the Argentine health sector, and at least 300 organizations provide healthcare coverage. Some 5 percent of total government expenditures are directed toward healthcare. Nearly 9 percent of the total Gross Domestic Product (GDP) is allotted to healthcare, and the government spends $2,067 (international dollars) per capita on healthcare. Around 49 percent of total healthcare expenditures derive from the government, and 56.8 percent of that amount is spent on social security benefits. There are 3.01 physicians, 0.80 nurses, 0.80 dentists, and 0.42 pharmacists per 1,000 population in Argentina. Free healthcare is provided to the poorest segment of the population. Around three-fourths of workers’ families are covered under government plans, but higher-income Argentines depend on the private sector for coverage. Approximately 63 percent of the over-60 population is covered under pension plans, but critics claim that insufficient benefits often make retirees newly poor. The government has tried a variety of programs to meet the health and social needs of the poor. For instance, the National Food Plan (PAN),
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which delivered food boxes directly to the poor, was replaced with a voucher system that failed to accomplish its goals. Subsequently, responsibility for providing basic needs was shifted to the provinces. Overall, the government has committed itself to improving health, and increased spending has resulted in improved health indicators. Despite government commitment, 38.5 percent of the population live in poverty, and 3 percent of Argentines survive on less than $1 a day. Unemployment stands at 11.6 percent. Around 97 percent of the people have sustained access to safe drinking water. Argentines have a life expectancy of 76.12 years, with women outliving men by an average of seven years. The population is highly literate (97.1 percent), and enrollment in primary and secondary schools is universal. The United Nations Development Programme (UNDP) Human Development Reports rank Argentina 36th of 177 countries on overall quality-of-life issues. Argentina ranks in the middle (134 of 225 countries) in infant mortality, with a current rate of 14.73 deaths per 1,000 live births. Maternal health (82 deaths per 100,000 live births) is also a major issue in the country, and efforts have been made at both the national and provincial level to make women and children less vulnerable. However, such programs as PROMIN, the mother–child nutritional program, have run into policy and implementation problems. On average, each woman gives birth to 2.16 children. Nearly three-fourths of Argentine women use some method of birth control. This is largely a result of the Sexual Health and Responsible Parenthood initiative established in 2003, which provides free contraceptives. The program focuses on education and on prevention of unwanted pregnancies and sexually transmitted diseases. At least 99 percent of deliveries are attended by skilled personnel, and 98 percent of women receive prenatal care. Between 1990 and 2004, infant mortality was reduced from 26 to 16 deaths per 1,000 live births, and under-5 mortality was reduced from 29 to 18 deaths per 1,000 live births. Eight percent of infants are underweight at birth, and 5 percent of under-5s are moderately so. One percent of this age group is severely underweight. Three percent of under-5s experience wasting, and 12 percent suffer from growth stunting. Required immunizations are fully subsidized by the government. As a result, 99 percent of
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infants are vaccinated against tuberculosis, and 95 percent are immunized against diphtheria, pertussis, and tetanus (DPT1); polio; and measles. Around 90 percent receive DPT3 and Haemophilus influenzae type B immunizations, and 88 percent are vaccinated against hepatitis B. While Argentina experiences the pollution problems common to industrialized societies, the government has committed itself to protecting the health of Argentines and the planet by voluntarily setting targets to reduce greenhouse emissions. HIV/AIDS has increasingly become a problem in Argentina, and the country is experiencing a 0.7 percent adult prevalence rate. More than 130,000 people are living with this disease, which has proved fatal to around 1,500 Argentines. SEE ALSO: Healthcare, South America. Bibliography. Central Intelligence Agency, “Argentina,”
World Factbook, www.cia.gov (cited January 2007); Commission on the Status of Women, “Argentina,” www.un.org/ womenwatch (cited January 2007); Manuel Antonio Garretón, et al., Latin America in the Twenty-First Century: Toward a New Sociopolitical Matrix (North–South Center Press, 2003); Carlos Gerardo Molina and José Núñez del Arco, eds., Health Services in Latin America and Asia (Johns Hopkins University Press, 2001); Roberto Martinez Nogueira, “Devising New Approaches to Poverty in Argentina,” in Dagmar Raczynski, ed., Strategies to Combat Poverty in Latin America (Inter-American Development Bank, 1995); Pan American Health Organization, “Argentina,” www.paho.org (cited January 2007); United Nations Children’s Fund, “Argentina,” www.unicef.org (cited January 2007); World Bank, “Argentina Data Profile,” devdata .worldbank.org (cited January 2007); World Health Organization, “Argentina,” www.who.int (cited January 2007). Elizabeth Purdy, Ph.D. Independent Scholar
Armenia The health of Armenia’s population of 2,976,372 has suffered greatly from the long conflict with Azerbaijani Muslims over the contested area of Nagorno-
Karabakh. The conflict has drained resources from the economy that might have been used to solve health and social problems. Resources have been further restricted by neighboring Turkey’s economic blockade and border closing that followed Armenia’s seizure of the contested area and further encroachment into Azerbaijani territory. Government corruption also interferes with efforts to improve the health and economic status of Armenians. Some 45 percent of Armenians are involved in the agricultural sector, and the economy is heavily dependent on international aid and regular remittances from Armenians who work abroad. Armenia’s population is highly literate (98.6 percent), and 97 percent of all children are enrolled in primary schools. At the secondary level, 66 percent of males and 71 percent of females regularly attend school. The United Nations Development Programme (UNDP) ranks Armenia 80th of 177 countries on overall quality-of-life issues. With a per capita income of $4,800, Armenia is ranked 133rd of 233 nations in world income. Distribution of income continues to be unequal, with the highest 10 percent of the population sharing 41.3 percent of the country’s resources and the lowest 10 percent claiming only 1.6 percent. Armenia has an unemployment rate of 31.6 percent, and 43 percent of the population lives in poverty. Around 13 percent of the population lives on less than $1 a day. The Armenian government spends 6 percent of the Gross Domestic Product (GDP) on health and provides $302 (international dollars) per capita for health costs. Some 80 percent of all health expenditures derive from private sources, and 80.60 percent of private expenditures are out of pocket. Social security provides no safety net for vulnerable segments of the population. There are 3.50 physicians, 4.35 nurses, 0.47 midwives, 0.26 dentists, and 0.04 pharmacists per 1,000 population in Armenia. Armenians have a projected life expectancy of 71.84 years and a death rate of 8.23 deaths/1,000 population. Only 1 percent of Armenia’s urban population lacks sustained access to safe drinking water, but 20 percent of rural households are not provided with this necessary resource. Among urban residents, 4 percent lack access to improved sanitation, and this number rises to 39 percent in rural areas. Both the health and economy of Armenians are adversely affected by occasionally severe earthquakes
Arrhythmia
and droughts. Toxic chemicals such as DDT in the soil further threaten public health. Armenia’s fertility rate is 1.33 children per woman, a reduction from 3.2 in 1970 and 2.5 in 1990. Approximately 61 percent of Armenian women use birth control. Only 3 percent of births occur outside the presence of a skilled attendant, and 92 percent of all women receive prenatal care. Maternal death occurs at a rate of 55 per 100,000 births. Improvements in reproductive issues are largely in response to the efforts of the United Nations and World Health Organization, who have worked with Armenian nongovernmental organizations to establish family planning clinics and programs. Between 1990 and the present, Armenia made great strides in childhood health, reducing infant mortality from 52 deaths to 22.47 deaths per 1,000 live births and under-5 mortality from 60 to 32. The rate of low birth weight infants has been reduced to 7 percent, and only 3 percent of children under 5 are moderately underweight. Only 2 percent of Armenian under-5s suffer from wasting diseases, but 13 percent of this age group experience growth stunting. Immunization rates have been a contributing factor in improving the health of Armenian children. Currently, 96 percent of under-1s receive tuberculosis vaccinations, and 97 percent are vaccinated against diphtheria, pertussis, and tetanus (DPT1). Some 93 percent of under-1s receive polio vaccinations. Immunization rates for measles and hepatitis B stand at 92 and 91 percent, respectively. Almost half of children under 5 suffering from diarrhea receive oral rehydration. While HIV/AIDS does pose a threat in Armenia (0.1 percent), the country has escaped the escalation that is plaguing much of Asia. This is partly due to efforts to educate the public about the use of condoms. Other preventable diseases still occur, and in 1998 a small village near Yerevan experienced an outbreak of cholera, reporting 25 cases but releasing no information on the number of deaths. In 2003, 5.3 cases per 100,000/population of malaria and 98 cases per 100,000/population of tuberculosis were reported. The government has attempted to reduce the negative health impacts of alcohol and tobacco by restricting advertising of these products. SEE ALSO: Healthcare, Asia and Oceania.
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Bibliography. Central Intelligence Agency, “Armenia,”
World Factbook, www.cia.gov (cited January 2007); Commission on the Status of Women, “Armenia,” www.un.org/ womenwatch (cited January 2007); Carlos Gerardo Molina and José Núñez del Arco, eds., Health Services in Latin America and Asia (Johns Hopkins University Press, 2001); Ts’ui-jung Liu, et al., Asian Population History (Oxford University Press, 2001); Jyotsna Pattnaik, ed., Childhood in South Asia (Information Age, 2005); United Nations, “Armenia,” unstats.un.org (cited January 2007); United Nations Children’s Fund, “Armenia,” www.unicef.org (cited January 2007); World Bank, “Armenia Data Profile,” devdata.worldbank.org (cited January 2007); World Health Organization, “Armenia,” www.who.int (cited January 2007). Elizabeth Purdy, Ph.D. Independent Scholar
Arrhythmia Arrhythmias are defined as an abnormal condition characterized by the heart having an irregular muscle contraction. Heart rhythm problems arise when the electrical impulses that normally stimulate the heart in a coordinated fashion malfunction. Consequently, the heart can be described as beating too fast, too slow, or in an irregular rhythm when arrhythmic. While most people will experience an arrhythmia at least once in their life, the consequences and underlying pathology vary greatly in severity. They can be present in the healthy heart with minimal consequences for the life of the individual or they can be an extremely serious problem that can threaten the individual, often leading to heart disease, stroke, or a sudden death. Diagnosis of arrhythmias is often suggested from the use of a stethoscope to auscultate the heart or feeling the peripheral pulses for any deviation from normality. When an irregular heart rate is suspected from these general methods, more specific methods such as an electrocardiogram (ECG or EKG) are employed. ECGs are more specific and can also detect arrhythmias that are inaudible or impalpable in nature. For those individuals in which an unpredictable arrhythmia is suspected, a Holter monitor, or ECG used for 24-hour periods, is recommended.
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Emergency treatment of cardiac arrhythmias is dependent on the hemodynamic status of the patient, which in turn determines the urgency of action needed. Indications of extremely urgent care include shock, hypotension, congestive heart failure, severe shortness of breath, altered level of consciousness, and chest pain. With other patients presenting with less serious symptoms, the proper management often means taking time to employ more diagnostic tests, taking a thorough medical history and performing a complete physical exam. Arrhythmias can be caused by a variety of underlying pathologies. These include atrial fibrillation, premature atrial contraction, sinus sickness syndrome, ventricular fibrillation, premature ventricular contraction, asystole, ventricular tachycardia, junctional tachycardia, and first-, second-, and third-degree heart blocks. Depending on the cause, several routes of treatment can be undertaken from a medical and surgical perspective. On an international scale, arrhythmias are often undiagnosed or unreported due to a lack of healthcare access and the necessary technological tools for treating troublesome arrhythmias. While industrialized countries with modern healthcare technology like the United States may have the tools to treat arrhythmias and prevent adverse events, countries on the other end of the economic scale are not as fortunate. Dealing with arrhythmias, regardless of country, will require strong tools for diagnosis and an equally strong integration of the patient into the healthcare system in order to achieve behavioral changes. SEE ALSO: American Heart Association (AHA); Congeni-
tal Heart Disease; Heart Disease (General); Heart Diseases—Prevention; Heart Valve Diseases. Bibliography. Cable News Network (CNN), “Sudden
Cardiac Arrest: Diseases and Conditions,” www.cnn.com (cited October 2006); Mary Boudreau Conover, Understanding Electrocardiography (Mosby, 2002); I. Eli Ovsyshcher, Cardiac Arrhythmias and Device Therapy: Results and Perspectives for the New Century (Futura, 2000); Michael Rosen, Foundations of Cardiac Arrhythmias (Informa Healthcare, 2000).
Jonathan Tan SUNY Stony Brook School of Medicine
Arteriosclerosis Arteriosclerosis literally means “hardening of the arteries” and is a broad term used to describe many diseases that cause thickening and loss of elasticity of the walls of arteries. Arteries are the vessels that carry oxygenated blood full of nutrients from the heart to organs throughout the body. Blood leaves the heart through the aorta, the largest artery in the body, and travels through arteries and then arterioles, the smallest arteries, to different organs. The arterial wall is made up of three distinct layers—an outer layer of tissue (adventitia), a muscular middle layer (media), and an inner layer of epithelial cells (intima). There are three recognized types of arteriosclerosis: atherosclerosis, arteriolosclerosis, and Monckeberg medial calcific sclerosis. Atherosclerosis is the most common and most important pattern of arteriosclerosis because its end result can be a harmful clot in the blood that may cause a heart attack, stroke, or disease of the peripheral blood vessels. How the entire process occurs is not entirely understood, but most scientists agree that it begins when the inner layer of a blood vessel, or the endothelium of the intimal layer, becomes injured. Some things that cause mechanical damage to the endothelium are high cholesterol and triglycerides, high blood pressure, and cigarette smoke. People who have an abnormally large amount of cholesterol or other lipids (fats) in their blood are often treated with lipid-lowering medications to prevent or slow the process of atherosclerosis. Once damage has occurred, platelets, cholesterol, other cells and debris accumulate over time in the damaged endothelium. These cells release chemicals which attract still more cells to the site of the injured layer. Fat deposits and builds up in and around these cells. The cells at the impaired area produce connective tissue that also deposits there. This conglomeration of cells, fat, debris, and connective tissue is called an atheroma, or fatty plaque. If we imagine an artery as a round tube and the blood flowing through the tube, it is easy to see that the bigger a plaque is, the more it affects the size of the lumen, or area that the blood has to flow through. If the wall of the vessel is thickened enough from a large atheroma or multiple atheromas, there will be decreased blood flow, which decreases oxygen supply to the body’s
Arthritis
organs. If blood flow is cut off to the heart, this can cause a myocardial infarction, or heart attack. If the blood supply to the brain is blocked, this can cause a stroke. Similarly, if the blood flow to the extremities is stopped, gangrene may occur. Often what blocks blood flow to these vital organs is a clot. Fortunately, atherosclerosis does not produce symptoms until the vessel’s luminal diameter has been decreased by 70 to 80 percent. Angina pectoris, or chest pain brought on by exertion, can be caused by this blockage of the lumen. In this situation, a person’s arteries may still have enough room for blood to travel when the person is at rest, but when he or she works hard and the heart pumps more blood, all of this extra blood cannot fit and causes chest pain. Interestingly, acute (sudden) events such as a heart attack, stroke, or sudden death are typically caused by rupture of plaques that only decrease the lumen by 50 percent. This happens because the plaque rupture releases several chemicals that aid in coagulation or are “proclotting.” The most important of these is tissue factor, which initiates the pathway of clotting. This leads to the formation of a clot in situ, right on top of the preexisting fatty plaque. So the long-standing, slowly accumulating process of atherosclerosis (which is going on inside all of us all the time) may cause symptoms such as angina pectoris if severe, but the life-threatening events such as heart attack or stroke are usually associated with this sudden plaque rupture on top of an already somewhat narrowed lumen. Arteriolosclerosis affects small arteries and arterioles, which are very small arteries. This involves thickening of the vessel walls that narrows the lumen. Like atherosclerosis in the larger vessels, the process of arteriolosclerosis can lead to ischemia or insufficient blood flow to organs supplied by these blocked vessels. Arteriolosclerosis is most often seen in people who have diabetes mellitus and/or high blood pressure, though some amount is a normal part of aging. Monckeberg medical calcific sclerosis is the third type of arteriosclerosis and is characterized by deposits of calcium in muscular arteries in people older than age 50. While these calcifications may be seen on imaging studies such as X-ray or may be palpable, they do not decrease the size of the lumen through which blood may travel. This is not considered a clinically significant disease and does not generally cause events such as heart attacks.
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See also: Angina; Angioplasty; Cholesterol; Heart At-
tack; Stroke.
Bibliography. Vinay Kumar, Nelso Fausto, and Abul
Abbas, Robbins and Cotran’s Pathologic Basis of Disease, 7th ed. (Saunders, 2005); Charles E. Rackley, “Pathogenesis of Atherosclerosis,” UpToDate, www.uptodateonline.com (cited October 2006).
Rachana Potru Michigan State University College of Human Medicine
Arthritis Arthritis is a general term, derived from the Greek language, and literally means joint inflammation (arthro-, or joint, and -itis, or inflammation; the plural is arthritides). Arthritis is the leading cause of disability in the United States, affecting more than 16 million adults. The incidence of arthritis is on the rise, with an expected 67 million adults to be diagnosed by 2030. Although the most common types of arthritis are osteoarthritis and rheumatoid arthritis, a variety of other forms exist, including those secondary to infection and metabolic disturbances. Osteoarthritis Osteoarthritis is the most common form of arthritis, affecting nearly one-third of people over the age of 65. As the population ages, so will the number of people affected by osteoarthritis—59 million cases are expected by 2020. Also known as degenerative joint disease, osteoarthritis is characterized by joint pain and mild inflammation due to deterioration of the articular cartilage that normally cushions joints. Joint pain is gradual in onset, occurring after prolonged activity, and is typically deep and achy in nature. One or multiple joints may be affected, predominantly involving the knee, hips, spine, and fingers. Approximately 90 percent of individuals experience crackling noises (crepitus) in the affected joint with motion. Muscle weakness and joint laxity or stiffness can occur as people become reluctant to move painful joints. Patients tend to have decreased joint stability and are predisposed to injuries such as meniscal
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and anterior cruciate ligament tears. Hip arthritis can affect gait, while arthritis of the hands can lead to decreased dexterity. Enlargement of the bony processes surrounding affected joints, called osteophytes (bone spurs), are common. Joint trauma, increased age, obesity, certain genetic components and occupations, and hobbies or sports that result in excessive joint stresses can result in the cartilaginous changes leading to osteoarthritis. Damage begins with the development of small cracks in the cartilage that are perpendicular to the joint. Eventually, cartilage erodes and breaks off, facilitating painful bone-on-bone contact. In due course, pathologic bony changes, such as osteophytes and subchondral bone cysts, develop and further restrict joint movement and integrity. Osteoarthritis may be divided into two types, primary and secondary osteoarthritis. Primary osteoarthritis is age-related, affecting 85 percent of individuals 75–79 years of age. Although the etiology is unknown, primary osteoarthritis is associated with decreased water retaining capacity in the cartilage, analogous to a dried-up rubber band that can easily fall apart. Secondary osteoarthritis is caused by another condition, such as joint trauma, congenital joint malalignment, obesity, hormonal disorders, and osteonecrosis. In addition, treatment for osteoarthritis is directed toward reducing pain and correcting joint mechanics, and may include exercise, weight loss, nonsteroidal anti-inflammatory drugs, steroids, and total joint replacement surgery. Autoimmune Arthritis Autoimmune arthritis is characterized by joint inflammation and destruction caused by one’s own immune system. Genetic predisposition and inciting factors, such as an infection or trauma, can trigger the inappropriate immune response. Rheumatoid arthritis is often associated with elevations in the serum level of an autoantibody called rheumatoid factor, whereas the seronegative arthropathies are not. Rheumatoid arthritis is a progressive inflammatory condition that can lead to decreased mobility and joint deformities. The worldwide prevalence is 0.8 percent, with a 3:1 predilection for women over men. Disease onset, mainly occurring in the third and fourth decades of life, may be acute or slowly progressive with initial symptoms of fatigue, weakness, malaise, weight
loss, and mild, diffuse joint pain. Rheumatoid arthritis tends to affect the hips, knees, elbows, ankles, spine, hands, and feet symmetrically. The disease course is characterized by periods of remission, followed by progressive exacerbations in which specific joints become warm, swollen, and painful. Morning stiffness, typically lasting about two hours, is a hallmark feature of rheumatoid arthritis. Patients with rheumatoid arthritis tend to complain of joint pain after prolonged periods of inactivity, whereas osteoarthritis is typically exacerbated with extended activity. Rheumatoid arthritis can be severely debilitating, resulting in a variety of deformities. Complete remission is reported in less than 10 percent of patients and typically occurs within two years of onset. Although the exact cause is unknown, rheumatoid arthritis results from the inflammation of the tissues surrounding the joint space. The thin lining of the joint space becomes thick and inflamed, taking on the form of a mass with finger-like projections (pannus), which invades the joint space and surrounding bone. Initially, this results in joint laxity; however, with progression, the bones can actually undergo fusion (ankylosis), limiting motion. The effect rheumatoid arthritis has on the hands is a defining characteristic, and clinically can be distinguished from osteoarthritis based on the distribution of joints affected in the hands. Rheumatoid arthritis tends to affect the more proximal joints, while osteoarthritis tends to affect the more distal joints of the hands and fingers. In severe cases, joint laxity and tendon rupture result in a characteristic deformity of the fingers and wrist. Rheumatoid nodules are thick fibrous nodules that form as a result of excessive tissue inflammation in rheumatoid arthritis. These nodules are typically present over pressure points, such as the elbows, Achilles tendon, and flexor surfaces of the fingers. Destruction of peripheral blood vessels (vasculitis) from the inflammatory process can occur in any organ, leading to renal failure, myocardial infarction, and intestinal infarction. In addition, rheumatoid arthritis is also associated with an increased risk of infections, osteoporosis, and atherosclerosis. Diagnosis of rheumatoid arthritis is based on the presence of several clinical features: rheumatoid nodules, elevated levels of rheumatoid factor, and radiographic changes. Although rheumatoid factor is
present in over 80 percent of people with rheumatoid arthritis, it cannot be used alone as a diagnostic tool because multiple conditions can be associated with elevated levels of rheumatoid factor. Since no therapy cures rheumatoid arthritis, treatment is directed toward decreasing symptoms of pain and inflammation. Surgical treatment may include total joint replacement, carpal tunnel release, and tendon repair. Hand splints are used to slow the progression of finger and wrist deformations. The overall lifespan of individuals with rheumatoid arthritis is typically shortened by 5–10 years and is highly dependent on disease severity. Disease severity and the likelihood of extra-articular manifestations are each directly related to serum rheumatoid factor levels. Several rheumatoid arthritis variants exist. In Sjogren’s syndrome, the characteristic symptoms include dry eyes, dry mouth, and rheumatoid arthritis. Furthermore, Felty syndrome is associated with splenomegaly (enlarged spleen), neutropenia (depressed white blood cell levels), and rheumatoid arthritis. In addition, juvenile rheumatoid arthritis is the most common form of childhood arthritis. Disease etiology and clinical course typically differ from that of adultonset rheumatoid arthritis and sufferers are prone to the development of other rheumatologic diseases, including rheumatoid arthritis. SPONDYLOARTHROPATHIES Ankylosing spondylitis, Reiter syndrome, psoriatic arthritis, and arthritis associated with inflammatory bowel disease are a subset of conditions known as spondyloarthropathies. Typically affecting the sacrum and vertebral column, back pain is the most common presenting symptom. Enthesitis, the inflammation at the insertion of a tendon or ligament into bone, is a characteristic feature of spondyloarthropathy. Unlike rheumatoid arthritis, spondyloarthropathies are not associated with elevated levels of serum rheumatoid factor. Spondyloarthropathies occur most frequently in males and in individuals with a genetic variation known as HLA-B27. Ankylosing spondylitis is the most common type of spondyloarthropathy, affecting 0.1 to 0.2 percent of the population in the United States and usually occurring in white males between 15 and 40 years of age. Genetic studies have shown that more than 90
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percent of all white patients with ankylosing spondylitis are HLA-B27 positive. Ankylosing spondylitis is characterized by arthritis of the spine and sacroiliac joints. In ankylosing spondylitis, extensive inflammation of the spinal column is present, causing a characteristic “bamboo spine” appearance on radiographs. Arthritis first occurs in the sacroiliac joints and gradually progresses up the vertebral column, leading to spinal deformity and immobility. Typical symptoms include back pain, which improves with activity, and heel pain due to enthesitis of the plantar fascia and Achilles tendon. Hip and shoulder arthritis may occur early in the course of the disease. Reiter syndrome is a clinical triad of urethritis, conjunctivitis, and arthritis. These patients typically develop acute oligoarthritis (two to four joints affected) of the lower extremities within weeks of a venereal or gastrointestinal infection. Reiter arthritis is not considered an infectious arthritis because the joint space is actually free of bacteria. Instead, an infection outside the joint triggers this form of arthritis. Other symptoms can include fever, weight loss, back pain, enthesitis of the heel and dactylitis. Most cases resolve within one year; however, 20 percent develop chronic progressive arthritis. Occurring almost exclusively in men, Reiter syndrome is strongly linked to the HLA-B27 gene variant, which is present in 90 percent of symptomatic individuals. Psoriasis is an immune-mediated inflammatory skin condition characterized by raised red plaques with an accompanying silvery scale, which can be painful and itchy at times. Though typically seen on the elbow, knees, scalp, and ears, plaques can occur on any surface of the body. About 10 percent of people with psoriasis develop a specific type of arthritis known as psoriatic arthritis. Psoriatic arthritis typically occurs after psoriasis has been present for many years. The prevalence of psoriatic arthritis in the United States is 0.1 percent, with a peak age of onset between 30 and 55. Usually less destructive than rheumatoid arthritis, psoriatic arthritis tends to be mild and slowly progressive, though certain forms, such as arthritis mutilans, can be quite severe. Onset of symptoms associated with psoriatic arthritis may be acute or insidious, initially presenting as oligoarthritis with enthesitis. Over time, arthritis
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begins to affect multiple joints (polyarthritis), especially the hands and feet, resulting in sausage-shaped swelling of the fingers and toes (dactylitis). Typically, the polyarticular pattern of psoriatic arthritis affects a different subset of finger joints than rheumatoid arthritis. It is not until years after peripheral arthritis has occurred that psoriatic arthritis may affect the axial joints, causing inflammation of the sacroiliac joint (sacroiliitis) and intervertebral joints (spondylitis). Furthermore, arthritis mutilans is a more severe and much less common pattern (<5 percent of psoriatic arthritis cases) resulting in bone destruction with characteristic telescoping of the fingers or toes. In addition, individuals with psoriatic arthritis necessitate more aggressive treatment if the onset of the condition occurs before the age of 20, there is a family history of psoriatic arthritis, there is extensive skin involvement, or the patient has the HLADR4 genotype. Crohn’s disease and ulcerative colitis, two types of inflammatory bowel disease, are complicated by arthritis in as many as 20 percent of patients. Although arthritis associated with inflammatory bowel disease typically occurs in the lower extremities, up to 20 percent demonstrate symptoms identical to ankylosing spondylitis. Arthritis is usually exacerbated in conjunction with inflammatory bowel disease exacerbations and lasts several weeks thereafter. Crystalloid Arthritis Joint inflammation, destruction, and pain can occur as a result of the precipitation of crystals in the joint space. Gout and pseudogout are the two primary types of crystalloid arthritis caused by different types of crystalloid precipitates. Gout is an extremely painful form of arthritis caused by the deposition of needle-shaped mono sodium urate crystals in the joint space. Initially, gout tends to occur in one joint only, typically the big toe (podagra), though it can also occur in the knees, fingers, elbows, and wrists. Pain, frequently beginning at night, can be so intense that patients are sensitive to even the lightest touch. Urate crystal deposition is associated with the buildup of excess serum uric acid (hyperuricemia), a by-product of everyday metabolism that is filtered by the kidneys and excreted in the urine. Causes of excess uric acid pro-
duction include leukemia/lymphoma, alcohol ingestion, and chemotherapy. Kidney disease and certain medications, like diuretics, can depress uric acid excretion, leading to hyperuricemia. Although acute gouty attacks are self-limited when hyperuricemia is left untreated for years, such attacks can recur intermittently, involving multiple joints. Chronic tophaceous gout occurs when after about 10 years, chalky, pasty deposits of monosodium urate crystals begin to accumulate in the soft tissue, tendons, and cartilage causing the appearance of large round nodules called tophi. At this disease stage, joint pain becomes a persistent symptom. Gout is most frequently seen in men in their 40s due to the fact that men tend to have higher baseline levels of serum uric acid. The prevalence of gout is increasing in the United States, likely due to the Western diet and the increasing incidence of insulinresistant syndromes. Pseudogout is caused by rhomboid-shaped calcium pyrophosphate crystals deposition (CPPD) into the joint space leading to symptoms that closely resemble gout. Typically occurring in one or two joints, such as the knee, ankles, wrists, and shoulders, pseudogout can last between one day and four weeks and is self-limiting in nature. A major predisposing factor is the presence of elevated levels of pyrophosphate in the synovial fluid. Because pyrophosphate excess can result from cellular injury, pseudogout is often precipitated by trauma, surgery, or severe illness. A deficiency in alkaline phosphatase, the enzyme responsible for breaking down pyrophosphate, is another potential cause of pyrophosphate excess. Other disorders associated with synovial CPPD include hyperparathyroidism, hypothyroidism, hemochromatosis, and Wilson disease. Unlike gout, pseudogout affects both men and women, with more than half at age 85 and older. Infectious arthritis Infectious arthritides are a set of arthritic conditions caused by exposure to certain microorganisms. In some instances, the microorganisms infiltrate the joint space and cause destruction, while in others an infection stimulates an inappropriate immune response leading to reactive arthritis. Typically caused by bacterial infections, infectious arthritis may also result from fungal and viral infections.
Artificial Limbs
Septic arthritis usually affects a single, large joint such as the knee. Although a multitude of organisms may cause arthritis, Staphlococcus aureus is the most common pathogen. Neisseria gonorrhoeae, the bacteria that causes gonorrhea, is the most common pathogen affecting sexually active young adults. The most common way by which bacteria enter the joint space is through the circulatory system after a bloodstream infection. Microorganisms may also be introduced into the joint by penetrating trauma or surgery. Factors that increase the risk of septic arthritis include old age (>80), recent surgery or skin infection, preexisting arthritic condition, immunosuppression, chronic renal failure, and the presence of a prosthetic joint. Postinfectious arthritis is seen after a variety of infections. Certain gastrointestinal infections, urinary tract infections, and upper respiratory tract infections can lead to arthritic symptoms after the infections themselves have resolved. Examples include Reiter syndrome and arthritis associated with rheumatic fever. SEE ALSO: Gout and Pseudogout; Immune System and
Disorders; Immunology; Infectious Diseases (General); National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS); Orthopedics; Orthopedist; Osteo arthritis; Psoriasis; Rheumatoid Arthritis. Bibliography. K. Aho and M. Heliovaara, “Risk Factors
for Rheumatoid Arthritis,” Annals of Medicine (v.36, 2004); D.T. Felson, “Clinical Practice. Osteoarthritis of the Knee,” New England Journal of Medicine (v.354, 2006); R.K. Kataria and L.H. Brent, “Spondyloarthropathies,” American Family Physician (v.69, 2004); J.R. O’Dell, “Therapeutic Strategies for Rheumatoid Arthritis,” New England Journal of Medicine (v.350, 2004); D. Samartzis and J.C. Liu, “Ankylosing Spondylitis,” Textbook of Neurological Surgery (Lippincott Williams & Wilkins, 2002); L. Sharma, D. Kapoor, and S. Issa, “Epidemiology of Osteoarthritis: An Update,” Current Opinion in Rheumatology (v.18, 2006). Thomas Christian Keller University of Virginia Dino Samartzis, D.Sc., M.Sc., Dip. EBHC Harvard University and Erasmus University Francis H. Shen, M.D. University of Virginia
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Artificial Limbs Artificial limbs are a type of prosthesis that replaces a missing part of the body. They are classified by the type of amputation they replace, for example, below the knee, above the knee, below the elbow, or above the elbow. For congenital (from birth) defects the terms refer to the affected body part. After an amputation, a patient may need to work with a rehabilitation specialist, such as a physical therapist, who will develop a personalized plan. This plan starts with ensuring proper healing of the amputation and includes exercises to keep the muscles and joints healthy and strong. The ultimate goal is for the patient to be able to use a prosthetic arm or leg in much the same fashion as the original limb. A variety of prostheses are available. Although artificial limbs used to be made from wood and certain types of metal, they have now been replaced with lighter materials such as fiberglass. Artificial limbs in the past had no mobility; they were replaced with models that had joints that could be bent (if unnaturally and not automatically) and fixed in different positions for different types of activities (e.g., sitting and walking). These, in turn, were replaced with robotic models capable of moving by themselves when controlled by an internal computer or directly by the user. In the past, they would be controlled by other muscles (such as those on the back), but today, direct neural control is preferable. In direct neural control of prosthetic limbs, limbs and appendages are moved by muscles that are stimulated by very small amounts of electricity from the nervous system. Even if the limb or appendage is absent, the nerves and impulses controlling the missing limb are (usually) still there, and the brain can send electricity to guide a “phantom” limb. If these currents are amplified and sent to a motor in the artificial limb, that limb can be moved via the same method used to control natural limbs. The current challenge for medical science is to perfect the system. In September 2005, Popular Science reported on a prototype neurally controlled limb developed by the Rehabilitation Institute of Chicago’s amputee program. This prosthesis required a unique surgery that rerouted multiple nerves that once connected to the arm of the user, to their chest, where the nerves interfaced with various electrodes. This design is the
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first neurally controlled prosthesis to move simultaneously at the shoulder, elbow, and wrist. It contains a 64-bit computer to coordinate its movements and allows the user to actually sense pressure when grasping an object. Many people in developing countries, particularly victims of landmines, cannot afford even the most basic artificial limbs. Antipersonnel landmines are often used indiscriminately and frequently result in injury or death of noncombatants. In the last 65 years, over 110 million mines have been spread throughout the world into an estimated 70 countries. Landmine victims use a disproportionately high amount of medical resources; the vast majority of incidents occur in regions and countries without a sophisticated medical infrastructure and with limited resources, where rehabilitation is difficult in the best of circumstances. It is estimated that only a quarter of the patients with amputation secondary to landmines receive appropriate care. The Department of Mechanical Engineering at the Uni-
versity of Waterloo (Canada) is currently developing a semiactive prosthetic leg geared specifically for landmine victims in Afghanistan. This prosthetic is geared specifically for transfemoral amputees. Many people with prosthetic limbs are able to continue to participate in sports. Interest and participation in disabled sports is growing rapidly nationally and internationally. In the first international Paralympic Games, which were held in Rome in 1960 after the regular summer Olympic Games, 400 athletes from 23 countries participated. The Paralympics is organized in a similar fashion to the Olympics. Athletes are categorized by their disability and grouped for competitions. This international competition is at a similar level to the able-bodied Olympics. The competitions are held every four years at the same venue as the Olympic competitions during the summer and winter. Between Olympic seasons, international world cup–level competitions are held. Most of the same countries that send athletes to the Olympics sponsor athletes to the Paralympic Games. SEE ALSO: Amputees; Bone Cancer; Bone Diseases; Bone
Health; Elbow Injuries and Disorders; Leg Injuries and Disorders; Rehabilitation; Shoulder Injuries and Disorders; Wrist/Arm Injuries and Disorders. Bibliography. Jesse C. DeLee, David Drez, and Mark D.
Miller, DeLee and Drez’s Orthopaedic Sports Medicine, 2nd ed. (Saunders, 2003); V. Putti, “Historic Artificial Limbs,” Clinical Orthopaedics and Related Research (v.412, 2003). Artificial limb technology has been continually refined, and simple early prostheses have since been replaced by robotic models with direct neural control.
Barkha Gurbani UCLA School Of Medicine
Asbestos/Asbestosis The inhalation of asbestos fibers is a serious health hazard. Asbestos is a confirmed human carcinogen, or cancer-causing substance, and is listed as such by the U.S. Department of Health and Human Services and the U.S. Environmental Protection Agency (EPA). Both the U.S. Department of Labor’s Occupational Safety and Health Administration (OSHA) and the U.S. National Institute for Occupational Safety and Health (NIOSH) also recognize asbestos as a danger-
ous cancer-causing agent. In the United States, approximately 10,000 people die each year of asbestosrelated diseases. Asbestos is the common, collective name applied to a group of six naturally occurring fibrous minerals of generally impure magnesium silicate composition. These minerals are chrysotile, anthophyllite, tremolite, actinolite, riebeckite, and grunerite (the last two often being identified by their trade names crocidolite and amosite, respectively). The ore of these asbestos minerals is composed of fibrous strands that tend to split into continuously smaller fibers, eventually reaching microscopic size. These tiny particles are readily airborne and, therefore, easily inhaled. Asbestos is found in two main natural forms: serpentine and amphibole. Fibers of the serpentine form are curly, while those of the amphibole variety are needle-like. Chrysotile is an example of an asbestos mineral that occurs in the serpentine form. Chrysotile is the type of asbestos most often used industrially in the United States today. Other asbestos minerals, such as tremolite, actinolite, and anthophyllite, occur in the amphibole form and, while less commonly used, are found in a variety of construction and insulation materials and have been used in some consumer products as well. Asbestos has several desirable physical properties that have made it a versatile material for use in thousands of commercial applications and household products. These properties include thermal stability, resistance to electrical conductivity and chemical degradation, high tensile strength, and light weight. Although the properties of asbestos have been known for several thousand years, it was not until the Industrial Revolution of the late 1800s that asbestos came into widespread use as insulation for kilns, boilers, steam pipes, and other high-temperature applications. Throughout most of the 20th century, asbestos had been used extensively for thermal insulation, electrical insulation, and fireproofing. It is present in many building materials including roofing products, acoustic ceilings, vinyl flooring, wallboard materials, plasters and stuccos, adhesives and caulking, seals, and gaskets. Asbestos has had application as a reinforcing material in tiles, plastics, and cements, and as friction components of automobile brake and transmission systems. Asbestos has been used routinely to insulate heating and cooling ducts and water pipes in homes, offices,
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and schools. Asbestos has also found its way into hundreds of consumer products, some as unlikely as handheld hair dryers, potting soil, and cigarette filters. Friability The crystal lattice of asbestos is easily fractured along two planes of cleavage. This results in a linear fragmentation pattern and, therefore, a fibrous form. As fibrous bundles of asbestos are separated into smaller and smaller units, they become invisible to the unaided eye. Ultimately, asbestos fibers can reach a size that is 10 times smaller than the diameter of a human hair. At this size, they can easily remain suspended in the air for a prolonged duration. Although such fibers will eventually settle, modest air currents will cause their resuspension. In this way, trillions of asbestos fibers can disperse throughout a building from one small and seemingly isolated source. The extent to which the asbestos fibers in asbestos-containing products become airborne depends on the product’s friability. The term friable refers to the tendency of a material to be crushed, crumbled, or pulverized into a powdery or dust-like consistency upon the application of only slight pressure. The usual criterion is “fingertip pressure.” Many asbestos-containing materials display this characteristic. Examples of friable asbestos-containing products include spray-on acoustic ceilings, wallboard joint compounds and plasters, and thermal insulation on water heaters and pipes. With many materials (including asbestos), age and desiccation lead to increased friability. Because friable materials are easily airborne, friability has been an important factor in asbestos-related health issues and in asbestos legislation. Friable materials with greater than 1 percent asbestos are regulated by law. Some applications of asbestos are considered to be nonfriable. Asbestos-containing products such as roofing shingles or floor tiles contain a hardening agent, which theoretically prevents friability. Such products are designated as nonfriable asbestos-containing materials and are unregulated by law. Under conditions of normal usage, however, nonfriable asbestos products are subjected to forces far exceeding the “fingertip pressure” criterion of friable asbestos products and over the years might eventually begin to crumble, thereby releasing asbestos fibers into the air. Home or office remodeling projects that involve sawing or drilling into nonfriable asbestos-containing
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products can also cause the hazardous release of airborne asbestos fibers. Asbestosis The inhalation of asbestos fibers is known to cause three serious respiratory diseases: (1) cancer of the lung tissue itself; (2) cancer of the lining around the lungs (a rare and fatal cancer called mesothelioma); and (3) asbestosis. Asbestosis is a noncancerous disease in which the deep air sacs of the lungs become scarred, stiff, and dysfunctional. Exposure to asbestos is the exclusive cause of this disease. Because airborne asbestos fibers are of microscopic size, they are not trapped by the natural filter systems of the nose and bronchial tubes. Instead, these invisible fibers are inhaled into the deep recesses of the lungs where they become lodged and cannot be expelled. There, they cause irritation of the lung tissue and trigger the release of chemicals in the body’s natural attempt to dissolve the foreign fibers. This, in turn, causes cell damage and inflammation of the lung tissue. With time, fibrosis or scar tissue develops in the small airways and air sacs (alveoli) of the lungs, encapsulating the asbestos fibers. This scarring results in a thickening that renders the lung tissue less flexible. As fibrous scar tissue replaces healthy lung tissue, the body’s ability to exchange oxygen and carbon dioxide is impaired. In this way, asbestosis results in a permanent and progressive decline in pulmonary function. Asbestosis is a chronic and debilitating disease that continues to advance long after there is no further exposure to asbestos. Symptoms, Diagnosis, and Treatment The primary symptoms of asbestosis are shortness of breath, chronic cough, chest discomfort, and loss of appetite. The unremarkable nature of these symptoms contributes to a difficult diagnosis. Like other asbestos-related diseases, the symptoms of asbestosis do not appear until 10 to 30 years or more after the initial exposure to asbestos. The diagnosis of asbestosis relies heavily upon a thorough medical history, especially focused on past asbestos-related employment. Imaging techniques such as X-rays and computerized tomography (CT) scans can show scarring and thickening of lung tissue that can indicate the presence of asbestos in the lungs.
A pulmonary function test that analyzes how well the lungs are working can also aid in this diagnosis. A conclusive diagnosis of asbestosis, however, is reached only through a biopsy. With this technique, a needle is inserted through the chest wall and a small sample of lung tissue is removed for microscopic examination. This is an important step that differentiates the diagnosis from a cancerous asbestos-related disease. There is no effective treatment for asbestosis. It is a disease that generally worsens with age. The use of a humidifier can ease the persistent cough that accompanies this illness. Although usually not fatal, asbestosis can dramatically limit a victim’s physical activity as breathing becomes more and more difficult. As the lungs become less able to function, supplemental oxygen may be a necessary part of treatment. Individuals who suffer from asbestosis are at a much greater than normal risk of developing lung cancer or mesothelioma (cancer of the membrane that envelops the lungs). Additionally, because there appears to be a synergistic effect between asbestos and tobacco, asbestosis sufferers who smoke raise the risk of developing cancer even higher. Because of the extraordinarily long latency period between exposure and the appearance of symptoms, it is likely that the incidence of asbestosis diagnoses will increase during the next several decades. Exposure Risk Asbestosis has been strongly associated with certain occupations. Victims of asbestosis have usually inhaled asbestos particles at a work site related to the construction trades, manufacturing industries, or repair services. At highest risk have been insulation installers, shipyard workers, pipe fitters, power plant workers, installers of linoleum, and automobile brake mechanics. There is some debate concerning both the type of asbestos and the length and level of exposure in relationship to the development of asbestosis and other asbestos-related diseases. For instance, it has been suggested that exposure to asbestos of the serpentine form (such as chrysotile) is less hazardous than exposure to asbestos of the amphibole form (such as tremolite). Likewise, it has been proposed that there might be thresholds of intensity and duration of exposure required to initiate a disease process. With regard to these debates, the medical evidence indicates that there is no level or duration of exposure to any form of asbestos that should be consid-
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ered safe. All such exposures are hazardous. There are documented cases of asbestos-related disease resulting from exposure to each of the six varieties of asbestos. Furthermore, while a dose-response relationship might exist, the length and level of asbestos exposure seem to lack verifiable thresholds. This is evidenced by the occurrence of nonoccupational cases of asbestos-related illness. Children of asbestos workers, whose only exposures were the hugs they received from their fathers who arrived home in asbestos-contaminated work clothes, have developed asbestosis and other asbestosrelated diseases as adults. Residents of towns occasionally traversed by asbestos-laden freight trains have experienced high rates of asbestos-related diseases. Even in these kinds of seemingly innocuous bystander exposures, asbestos presents a serious health risk.
tion banned only new asbestos products, allowing the continued manufacture, use, or importation of any asbestos-containing product that was already on the market as of July 12, 1989. This regulation allows many consumer products to legally contain limited amounts of asbestos. Although the use of asbestos has decreased, it is still found in many residential and commercial buildings as well as many consumer products and, therefore, continues to represent a serious health risk.
Asbestos Legislation The correlation between asbestos and poor respiratory health has been observed since the late 19th century when asbestos factory workers showed high rates of lung disease. By 1920, several studies in the United States had shown that asbestos workers, especially those who had begun work at a young age, were dying prematurely. Medical authorities have widely recognized asbestos as a serious health hazard and a potent carcinogen since the early 1960s. In 1972, OSHA established regulations limiting asbestos exposure of employees at industrial work sites. While these regulations caused some decline in the use of asbestos, provisions in the law allowed for approved levels of exposure in certain industries. While medical experts warn that there is no safe level of exposure to asbestos, regulatory agencies have often followed an “acceptable exposure” philosophy. By 1978, a ban had been placed on the use of “popcorn ceilings” of sprayed-on asbestos-containing material and other extremely friable asbestos products. This ban, however, permitted the use of remaining inventories; therefore, these asbestos ceilings continued to appear in houses built through the mid-1980s. Large stocks of other friable asbestos products also remained in the marketplace for many additional years. In 1989 the EPA established a phase-out rule on the manufacture, use, or importation of all asbestos products. Such activities were scheduled to cease by 1997. However, in October 1991, a U.S. federal court overturned this EPA regulation. The revised regula-
James R. Jett, Clinical Respiratory Medicine (Mosby, 2004); Asbestos Resource Center, “Asbestosis,” www.asbestos resource.com (cited October 2006); David M. Hansell, et al., Imaging the Diseases of the Chest, (Elsevier Mosby, 2005); Marvin I. Schwarz and Talmadge E. King Jr., Interstitial Lung Diseases (Decker, 2003).
SEE ALSO: Cancer (General); Lung Cancer; Malignant Me-
sothelioma; Occupational Health; Occupational Injuries; Occupational Medicine; Occupational Safety and Health Administration (OSHA). Bibliography. Richard K. Albert, Stephen G. Spiro, and
Paul J. Clerkin Sacramento City College
Asian-American Health Asian Americans compose a large and growing portion of the U.S. population. Asian-American populations include the following ethnic groups: Asian Indian/Pakistani, Chinese, Filipino, Japanese, Korean, Southeast Asian, and Pacific Islanders. The AsianAmerican portion of the population has been increasing since the mid-1960s, when immigration rose from China, India, the Philippines, Vietnam, Southeast Asia, and Korea. Recent U.S. census data report over 11 million Asian Americans; that number is projected to grow steadily in the next 50 years. Asian-American populations are concentrated in the western, northeastern, and some southern states, with the largest concentrations in Hawaii, California, Washington, New Jersey, and New York. The majority are born outside of the United States, but there is a growing portion of U.S.-born Asian Americans.
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Asian-American Health
Asian Americans are especially diverse, hailing from various countries and 43 different ethnic groups. The many groups speak over 100 languages and dialects and have distinct cultures. A large percentage of Asian-American households have limited English proficiency. Additionally, the sociodemographic profile of Asian Americans is extremely wide, with large variances in education attainment and income. Researchers have had a difficult time assessing and analyzing the health status of Asian Americans because of their diversity. However, researchers have implemented better data collection protocols and are becoming better able to assess the health needs of Asian Americans. Additionally, the already-diverse origins of Asian Americans become more diverse when Pacific Islanders are categorized along with Asians. The inclusion of Pacific Islanders can complicate data analysis and may cause inaccuracies when trying to interpret health indicators. Starting with the 2000 census, Pacific Islanders and Asians have been divided into two distinct ethnic groups, allowing for more efficient and accurate data collection and health status analyses. Morbidity and mortality incidence and prevalence rates vary for Asian Americans. Asian Americans are genetically predisposed to certain illnesses in addition to the major illnesses that affect the general American population. Asian Americans suffer from disproportionate rates of cancer, chronic obstructive pulmonary disease, hepatitis B, HIV/AIDS, and tuberculosis. Asian Americans have higher rates of liver cancer; lung cancer is the leading cause of cancer death. Vietnamese women have higher rates of cervical cancer, and Asian Indians have higher rates of coronary heart disease and parasitic infections. Health Status Only a very limited number of studies have focused on the overall health status of Asian Americans, and according to the Substance Abuse and Mental Health Services Administration, assessment of the diverse Asian-American ethnic category as a whole can be misleading. However, Asian Americans have been shown to have higher rates of preventable disease. The Office of Minority Health states that factors that contribute to poorer health outcomes include language and cultural barriers, stigmas associated with certain health conditions, and access to care (includ-
ing lack of health insurance). According to the Centers for Disease Control and Prevention (CDC) and the Department of Health and Human Services, the leading causes of death among Asian Americans in 2000 were as follows: • cancer • heart disease • stroke • unintentional injuries • diabetes • influenza and pneumonia • chronic lower respiratory disease • suicide • nephritis, nephrotic syndrome, and nephrosis • septicemia Evidence suggests that Asian Americans may suffer from disproportionate rates of morbidity and mortality. In 1998, the National Center for Health Statistics stated that cancer has been the number one cause of mortality among Asian-American women since 1980. Incidence of colorectal cancer is extremely high among Asian Americans. The Chinese have higher mortality rates for lung and bronchial cancer than other Asian-American subgroups. Numerous studies have documented a higher burden of cancer morbidity and mortality within Filipino, Japanese, Korean, Vietnamese, and Hmong communities. Studies have shown that cases of type 2 diabetes are frequent among some Asian-American subgroups. Anyone who has a family member with type 2 diabetes has a higher risk for diabetes. Some scientists state that the food choices of Asian Americans may cause them to be at higher risk of developing diabetes. The Department of Health and Human Service’s National Diabetes Education Program issued a press release stating that Asian Americans (including Native Hawaiians, Filipinos, and Japanese Americans living in Hawaii) are more likely to have diabetes than other ethnic groups. The American Heart Association stated that heart disease and stroke were the leading causes of mortality among Asian-American males and females in 1999. Hawaiians have been shown to have higher incidence of morbidity and mortality from heart disease. Studies and formative research regarding heart disease in Asian communities suggest that members of this group may not be aware of their cholesterol levels, indicating a possible gap in knowledge and access to
care. CDC studies have indicated that the majority of Asian Americans have not had their cholesterol levels checked. Other risk factors for heart disease include obesity, which also disproportionately affects the various Asian-American subgroups. Asian Americans are at risk for contracting HIV/ AIDS, with men accounting for the largest portion of cases. Asian Americans are at a higher risk of contracting two of the cofactors of HIV infection: hepatitis B and tuberculosis. There remain unidentified risk factors that are not thoroughly understood. This may be attributable to the stigma associated with issues surrounding sexuality and sexual behaviors. Asian Americans may not seek or be exposed to the health information that would inform them of their HIV/ AIDS acquisition risk factors. Health promotion, education, and prevention campaigns must consider the cultural intricacies of the many Asian-American subgroups. Language barriers, economic barriers, and stigma/prejudice factors may be inhibiting attainment of health information and healthy behaviors. Additionally, campaigns should incorporate cultural normative behaviors and group identities. It should also be noted that members of subgroups may subscribe to alternative medicine and therapies. The use of alternative medicine as a means to achieve good health is not yet completely understood or quantified. Health Initiatives In addition to responses to the issues surrounding the racial/ethnic classification of Asian Americans and data gaps, there have been other initiatives to address health problems faced by Asian Americans. Many organizations have been chartered specifically to help Asian Americans, or to address related issues. These groups include the Asian and Pacific Islander Partnership for Health, the Asian and Pacific Islander American Health Forum, the National Asian Women’s Health Organization, the Association of Asian Pacific Community Health Organizations, the Office of Minority Health, and the National Center on Minority Health and Health Disparities. Healthy People 2010, an initiative launched by the Department of Health and Human Services, focuses upon the elimination of health disparities affecting Asian-American communities. Healthy People 2010 has acknowledged the deficiency of data collection for
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Asian Americans and the subgroups and has also set forth an agenda to implement uniform data collection methods. The intiative is collecting data for 10 leading health indicators, which include obesity, tobacco use, substance use, sexual behavior, mental health, injury and violence, environmental quality, immunization, and access to healthcare. The data will ensure a more accurate understanding of Asian-American health status and will lead to stronger health assessments. President George W. Bush signed an executive order to form an Advisory Commission on Asian Americans and Pacific Islanders in 2001. In a 2003 report, this commission acknowledged that the biggest concern for these communities is health. The report stated that Asian Americans have been overlooked because they have been the “silent minority” and “often perceived as compliant, passive, and self-reliant.” It also acknowledged the wide array of cultural differences among Asian Americans, as well as the importance of these cultural traditions within their communities. It found that health programs and health reports must incorporate the unique cultural aspects of Asian Americans in order to be fully responsive to their needs, and it called for further action to ensure that Asian Americans achieve and maintain good health. SEE ALSO: Chinese Medicine, Traditional; Department of
Health and Human Services; Healthcare, Asia and Oceania; Healthcare, U.S. and Canada; National Asian Women’s Health Organization (NAWHO); National Center for Complementary and Alternative Medicine (NCCAM). Bibliography. National Diabetes Education Program,
“Millions of Asian Americans and Pacific Islanders at Increased Risk for Type 2 Diabetes: New Awareness Campaign Uses Generational Appeal to Help Reverse Diabetes Risk,” www.ndep.nih.gov (cited February 2007); Office of Financial Management, “Standards for Data Collection and Reporting on Race/Ethnicity,” www.ofm.wa.gov/pop/race (cited February 2007); U.S. Census Bureau, Census 2000, www.census.gov (cited February 2007); U.S. Equal Employment Opportunity Commission, “Introduction to Race and Ethnic (Hispanic Origin) Data for the Census 2000 Special EEO File,” www.eeoc.gov (cited February 2007). Sudha Raminani The Fenway Institute
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Association for International Cancer Research (AICR)
Association for International Cancer Research (AICR) The Association for International Cancer Research (AICR) is an independent, Scottish-based charity that funds research by leading scientists around the world into the cause and prevention of cancer. The association supports fundamental research into the causes, mechanisms, diagnosis, treatment, and prevention of cancer with an emphasis on scientific rather than clinical research. The AICR is also interested in supporting recently qualified researchers, promoting new discoveries, working in fields that traditionally have been underfunded, and international collaboration. The association is governed by a seven-member board of directors that sets policy relevant to group’s stated mission. The AICR’s Scientific Advisory Committee (SAC) is made up of some of the world’s most prominent cancer researchers, who meet regularly on a volunteer basis to evaluate proposals and counsel the board on the most appropriate areas of support. The SAC evaluates and grades each proposal received by the association, recommends appropriate funding levels, and charts specific courses of action. The AICR emphasizes the need for a flexible approach to funding and routinely examines new approaches to solving problems associated with cancer research. At times this involves the funding of preliminary research efforts to determine whether major funding of a particular project is warranted. Because the association understands that cancer is a worldwide problem, and that the incidence of different forms of cancer varies from country to country, the AICR recognizes the importance of international collaboration. AICR policy is to support research into the causes, mechanisms, diagnosis, treatment, and prevention of cancer. This support is not limited to the United Kingdom but is available to researchers working in recognized research institutions in any country in the world. As a result AICR encourages collaboration between research groups in different institutions and different countries. The majority of AICR’s research funding takes the form of three-year project grants that cover the direct costs of conducting the research, but not the indirect and infrastructure costs, which are met by the research institutions. The AICR also awards six-year
cancer research fellowships, which include the principle investigator’s salary. AICR only supports research conducted at nonprofit-making institutions and for nonprofit-making purposes. The association reserves the right to share in the intellectual property rights and any resulting financial benefits that result from research funded by the AICR, so that any such profits may be directed toward charitable objectives. In so doing the group also maintains a clear policy that it will not support research in an institution or in a situation where the main purpose of the research being conducted is for the profit of another person or organization. AICR does not give any particular area of research greater priority, but awards its funds on the basis of the scientific quality of the applications received. All other factors being equal, preference is shown toward applications from younger researchers who are establishing themselves as principal investigators, and those promoting innovative research. See also: American Association for Cancer Research
(AACR); European Association for Cancer Research (EACR); International Agency for Research on Cancer (IARC). Bibliography. Association for International Cancer Re-
search, www.aicr.org.uk (cited September 2006); John Higginson, Calum S. Muir, and Nubia Muñoz, Human Cancer: Epidemiology and Environmental Causes (Cambridge University Press, 1992); International Cancer Research Portfolio, www.ncri.org.uk (cited September 2006). Ben Wynne, Ph.D. Gainesville State College
Association of Maternal and Child Health Programs (AMCHP) Throughout its 60-year history, the Association of Maternal and Child Health Care Programs (AMCHP) has acted as a resource and advocate for women and their families. AMCHP seeks to protect the health and well-being of its constituency, particularly those who are economically disadvantaged and underserved,
Association of Maternal and Child Health Programs (AMCHP)
by embracing values of leadership, social justice, diversity, equity, integrity, partnership, empowerment, and honesty. National headquarters is located at 1220 19th Street, NW, Suite 801, Washington, D.C. Information is also available by telephone (202-775-0436) and on the internet (www.amchp.org). AMCHP is governed by a board of directors, which is responsible for shaping policy. The Executive, Finance, and Governance Committees serve as advisers to the board. Special-issue organizational committees include Emergency Issues, Health Care Finance, and Workforce Development. AMCHP is supported by membership dues, donations from individuals, and grants from corporations such as the Annie E. Casey Foundation, the Commonwealth Fund, and the W.K. Kellogg Foundation, and through cooperative agreements with the Maternal and Child Health Bureau and the Centers for Disease Control and Prevention. AMCHP membership is composed of state public health leaders and includes directors and coordinators of women’s and children’s health programs, academicians, family healthcare professionals, and members of the AMCHP constituency. As a group, the AMCHP membership oversees public health programs that serve more than 27 million women, children, and youth throughout the United States. This constituency includes 80 percent of all American infants, half of all pregnant women, and a fifth of the country’s children. AMCHP has a strong commitment to providing quality maternal healthcare, which in turn produces healthier infants and children. Prenatal and postnatal programs have been established to fulfill this need, and an antismoking campaign targets pregnant mothers. Because African-American infants are twice as likely as white infants to be underweight at birth, AMCHP has established Action Learning Labs across the country to address the disparity. Other health initiatives involve HIV/AIDS education and prevention of mother-to-child transmission of the disease. AMCPH partners with the National Network of State Adolescent Health Coordinators to promote overall good health among youth and their families. The Conceptual Framework for Adolescent Health allows AMCHP to target unhealthy behaviors by teaching youth about HIV/AIDS and sexually transmitted diseases (STDs), and special efforts are directed at averting unintended pregnancies. Children
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with disabilities or chronic illnesses are also a special focus of AMCHP’s efforts, and the organization works with national and state officials to meet the needs of this vulnerable group through healthcare and support services. Professional training and continuing education are essential in the health profession; the online training program, MATRICHS, which is offered through a partnership with the University of Rochester, allows health professionals to obtain practical and analytical skills in a flexible setting. Because of the need to represent a population that often lacks personal and financial resources, AMCHP is a strong advocate for universal health insurance and care for Americans in need. AMCHP also lobbies for a strong government commitment to national health. Advocates regularly track and analyze policy proposals that range from Medicaid reform to bioterrorism. The data collected by AMCHP substantially strengthen advocacy efforts in addition to shaping internal policies and programs. AMCHP is also a member of the Friends of Title V, which provides a safety net for Americans with low incomes, those who are at risk, and those who are underinsured or uninsured. The coalition maintains pressure on the national government to fund the Title V block grant. See also: Administration for Children and Families
(ACF); Adolescent Health; American Pregnancy Association (APA); Infant and Toddler Health; Reproductive Health (General).
Bibliography. Heather E. Aldred, ed., Pregnancy and
Birth Sourcebook (Omnigraphics, 1997); Judith Ann Allender and Barbara Spradley, Community Health Nursing: Promoting and Protecting Public Health (Lippincott, Williams, and Wilkins, 2005); Association of Maternal and Child Health Programs, www.amchp.org (cited January 2007); Barbara Ehrenreich and Deirdre English, For Her Own Good: Two Centuries of the Experts’ Advice to Women (Anchor, 2005); Environmental Protection Agency, Protect Our Children, Protect Our Future (Environmental Protection Agency, 2003); Kristine Krapp and Jeffrey Wilson, eds., The Gale Encyclopedia of Children’s Health: Infancy through Adolescence (Thomas Gale, 2005); Gloria Leifer, Introduction to Maternity and Pediatric Nursing (Saunders, 2003); U.S. Department of Health and Human Services, “National Survey of Children’s Health: The Health and Well-Being of
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Association of Schools of Public Health (ASPH)
Children in Rural Areas,” www.mchb.hrsa.gov/ruralhealth (cited January 2007). Elizabeth R. Purdy, Ph.D. Independent Scholar
Association of Schools of Public Health (ASPH) The Association of Schools of Public Health (ASPH) was established in 1953 to facilitate communication among leading healthcare professionals and the leadership of its member schools. The association is the only national organization representing deans, faculty, and students of accredited member institutions and other programs that are in the process of seeking accreditation as schools of public health. As a result, the ASPH provides a focus and platform for enhancing existing and emerging academic public health programs; works with various agencies of the federal government on projects designed to strengthen public health education and the public health profession; assists member schools in developing and coordinating national health policies; serves as an information center for government and private groups and individuals with concerns related to those of member institutions; and assists in meeting national goals related to disease prevention and overall improvements in health and healthcare. The association is governed by a 15-member board of directors charged with maintaining the organization’s focus and ensuring that the ASPH adheres to its stated mission and goals. The association’s standing committees and councils recommend program directions and policies to both the board and the membership in general. In addition to ongoing responsibilities as a liaison between schools, government, professional organizations, and the general public, the ASPH maintains a number of databases related to its mission that are constantly updated. The association’s data center collects and analyzes data on applicants, students, graduates, and faculty of the schools and conducts cost studies related to education and expenditures in member institutions. Students of schools of public health are diverse in their ethnic, economic, and professional backgrounds.
They come from all areas of the United States and the rest of the world. Some enter graduate schools of public health directly from undergraduate school or another graduate program, others have worked for some time in other fields and are returning to school to enhance their careers. Public health has something for everyone because of its multidisciplinary approaches and incorporation of a wide range of interests and abilities. ASPH is home to the membership of accredited schools of public health and several member programs of public health that are seeking accreditation as schools of public health. Each school has its own character and environment. These schools offer a wide range of degree concentration programs. Because of the ASPH’s commitment to eliminating health disparities, the association has established an initiative to provide information about the health disparities research activities of member schools and diversity-related issues in public health. This initiative is a venue for sharing research activities and provides important information that will help in diversifying schools’ own faculty and student bodies—a necessary step toward helping eliminate U.S. health disparities. The goals of this resource center are to disseminate best practices for minority faculty and student recruitment and retention; facilitate increased research about health disparities; encourage development and implementation of multicultural perspectives across curricula; increase the cultural competence of faculty, staff and students; and create and maintain partnerships with minority health professions, schools, and other minority-based institutions. See also: American Association for Health Education
(AAHE); American Public Health Association (APHA); European Public Health Alliance (EPHA); European Public Health Association (EUPHA); National Center for Public Health Informatics (NCPHI); Public Health.
Bibliography. Association of Schools of Public Health,
www.asph.org (cited September 2006); Edward W. Maibach and Roxanne Louiselle Parrott, eds., Designing Health Messages: Approaches from Communication Theory and Public Health Practice (SAGE, 1995). Ben Wynne, Ph.D. Gainesville State College
Association of Women’s Health, Obstetric, and Neonatal Nurses (AWHONN)
Association of Women’s Health, Obstetric, and Neonatal Nurses (AWHONN) Through its membership of more than 22,000 healthcare professionals residing in the United States, Canada, and abroad, the Association of Women’s Health, Obstetric, and Neonatal Nurses (AWHONN) promotes the health of women and newborn infants. The association was formed in 1969 as a branch of the American College of Obstetricians and Gynecologists but became independent in 1993. The 52 geographical sections that make up the association are subdivided into 163 chapters. AWHONN is headquartered at 2000 L Street, NW, Suite 740, Washington, D.C. 20036. Information on the organization is available by telephone (800-673-8499 in the United States or 800-245-0231 in Canada) or on the internet (www.awhonn.org). AWHONN provides nurses with information vital to the performance of their duties in homes, hospitals, and ambulatory settings through education, advocacy, research, and collaborative efforts with other organizations. The focus of AWHONN’s activities is on childbearing and the newborn, women’s health issues throughout life, and professional matters of interest to AWHONN members. Professional enrichment is provided through an annual leadership conference designed to orient, train, and mentor both new and continuing leaders, and the association’s Web site serves as a major resource tool for members and the public. AWHONN is governed by a board of directors with recommendations from an advisory panel. Advocacy interests are promoted through the activities of two in-house lobbyists and the joint efforts of AWHONN leadership. The AWHONN Consulting Group is concerned with the financial and business-related issues of healthcare delivery to the target group. AWHONN is involved in the March of Dimes program, which generates funding to prevent premature births that may lead to devastating health problems. Other AWHONN initiatives and programs that impact on women’s and infant’s health include the NearTerm Infant Initiative Resource Center, the Folic Acid Awareness program, the National Summit on Preconception Care, Covering Kids and Families Back-toSchool Campaign, influenza preparedness, Hurricane
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Katrina relief, breast cancer awareness, and cervical cancer screening. AWHONN is also a supporter of Gynecologic Cancer Awareness Month and Cover the Uninsured Week. A multiyear cardiovascular health program has been instituted to meet the needs of women in general and nurses in particular. The official research publication of AWHONN is the Journal of Obstetric, Gynecologic, and Neonatal Nursing. The Association also publishes AWHONN Lifelines, which is geared toward clinical practice management. Publications designed to serve the public interest include Every Woman: The Essential Guide for Healthy Living, and the Baby Talk Childbirth Education Guide. Every Woman is distributed free of charge at healthcare centers throughout the United States. Recent advances in resource development include the creation of the AWHONN Industry Membership (AIM) program, sponsored by 35 corporate members; a 23 percent increase in annual operating revenue; increased research grant opportunities; enhanced advanced practice registered nurse (APRN) education; and a comprehensive fund-raising campaign that increased donations by 400 percent. Registered nurses are graduates of accredited nursing programs, and additional training is necessary for nurses who focus on the care of critical groups. Nurses who specialize in clinical obstetrics care for pregnant women are involved in the delivery and postpartum periods. They receive special training that prepares them for dealing with high-risk maternity situations. Neonatal nurses are concerned with caring for infants, particularly those who are at highrisk or critically ill, and for their families. Both obstetric and neonatal nurses must be certified by the National Certification Corporation for the Obstetric, Gynecologic, and Neonatal Nursing Specialties or the American Nurses Credentialing Center. AWHONN offers an evidence-based clinical practice guideline program and a clinical practice monograph series to enhance professional nursing education. Efforts to extend the reach of neonatal nursing led AWHONN to double the number of instructors for the Fetal Heart Monitoring Principles and Practices Program, which in turn led to an increase in the number of classes offered and the number of students signing up for the classes. An Advanced Fetal Heart Monitoring Principles and Practices Workshop was also added to the curriculum.
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Asthma
See also: American Academy of Nurse Practitioners
(AANP); American College of Nurse-Midwives (ACNM); American College of Obstetricians and Gynecologists (ACOG); American Nurses Association (ANA). Bibliography. Association of Women’s Health, Obstet-
ric, and Neonatal Nurses, www.awhonn.org (cited January 2007); Glenys Boxwell, Neonatal Intensive Care Nursing (Routledge, 2000); Gloria Leifer, Introduction to Maternity and Pediatric Nursing (Saunders, 2003); Gloria Leifer, Maternity Nursing (Elsevier/Saunders, 2005); Leonard Lowdermilk and Shannon E. Perry, Maternity and Women’s Health Care (Mosby, 2004); Sharon Smith Murray, et al., Foundations of Maternal-Newborn Nursing (Saunders, 2002); Judith Pence Rooks, Midwifery and Childbirth in America (Temple University Press, 1997); Helen M. Sterk, et al., Who’s Having This Baby? Perspectives on Birthing (Michigan State University Press, 2002); Lorri A. Zipperer, ed., The Health Care Almanac: A Resource Guide to the Medical Field (American Medical Association, 1995). Elizabeth R. Purdy, Ph.D. Independent Scholar
Asthma Globally, asthma incurs a large burden of disease, affecting an estimated 300 million persons. Only recently, however, has the condition been recognized and addressed at the international level through efforts such as the Global Initiative for Asthma (GINA). As more attention is given to asthma and its increasing rates, the global campaign to address this disease and its causes will become more effective and comprehensive. On the medical spectrum, asthma also requires a “global” perspective, representing a unique intersection of many areas of health. It draws together the fields of pediatrics and adult medicine, affecting certain subgroups in each disproportionately. It lies at the crossroads between preventive medicine, acute care, and chronic disease management. Asthma treatments and technologies involve medical specialties from pulmonology to immunology to infectious disease. Furthermore, looking into the causes of this condition invokes conversations ranging from the social determinants of health and health inequities to
environmental health, and toward the genetic susceptibilities underlying asthma. Coming to a well-accepted definition for asthma has been a difficult task, and has consequently led to the difficulty in describing asthma prevalence on local and national levels, much less on the international level. Asthma, most broadly defined, is a chronic inflammatory disorder of the airways of the respiratory tract, usually diagnosed in childhood. The signs and symptoms of asthma are nonspecific, overlapping with other respiratory and cardiovascular conditions. Cough (especially in the morning and night), wheezing, chest tightness, and intermittent dyspnea are common patient complaints. In addition, there is often an episodic nature of the symptoms, often associated with “triggers” (e.g., dust, mold, or exercise). However, an additional criteria that distinguishes asthma from chronic obstructive pulmonary disorder (COPD), a condition with similar symptoms, is the reversibility of airflow obstruction that occurs with asthma. The diagnosis of asthma is usually made clinically, based on a patient’s symptoms. For population-based estimates, surveys using validated questionnaires that assess patient symptoms have relatively good sensitivity (0.85 for children, 0.80 for adults) and specificity (0.81 for children, 0.97 for adults), using physician assessment as the “gold standard.” Epidemiologic studies, meanwhile, suggest the combination of testing for bronchial hyperresponiveness and the self-report of symptoms (e.g., wheezing). However, Litonjua and Weiss remind us that “Each method of selecting asthma patients has its inherent problems. It is likely that some bias in reporting of cases is present in each group and that the biases in each approach are different.” Factors associated with asthma The causes and contributing factors to asthma are varied, and often hard to assess. These factors may be broadly defined on a molecular/genetic level, in the context of other health conditions, and through the lens of the social determinants of this condition. As an inflammatory condition, it is not surprising that mast cells, eosinophils, and lymphocytes are implicated in the immunologic dysregulation that appears to underlie asthma. Drazen summarizes the pathogenesis of asthma as follows: B lymphocytes set off a cascade, via cytokines, that activate mast cells and eosinophils that cause the inflammation of air-
ways, cellular infiltration into the airways (involving T lymphocytes and eosinophils), and further cytokine production. Currently, we do not know the root cause for this dysregulation, though some evidence suggests that an early-in-life shift imbalance between Th2 and Th1 cells is to blame. We also know that elevated IgE levels are associated with asthma. IgE is an antibody that is elevated in atopy, the term for conditions of hypersensitivity to environmental allergens (e.g., asthma, eczema, hay fever, rhinitis). A further pathway by which predisposition to asthma is thought to occur is maternal smoking during pregnancy, which through cellular effects on the fetus’s developing airways, leads to small airways relative to the size of the lung parenchyma, and might explain increased rates of asthma seen in children with fetal exposure to environmental tobacco smoke (ETS). The genetics of asthma are complex, and the genes causing aggregation of asthma in families have yet to be identified. Current evidence suggests multiple genes and gene pathways to be involved in predisposing some to asthma, with hope that as these can be more clearly elucidated, gene-based therapies will become a possibility. There are certain factors and conditions that make asthma more or less likely. Regarding the former, the following conditions are associated with asthma: • Personal or family history of allergies and/or atopy: • Gender: Predominantly male disease in childhood, equal prevalence across the sexes in young adults (ages 20–40) and more common in females in adults over 40 years of age. • Smoking and exposure to environmental tobacco smoke: Numerous studies show correlations between active smoking and asthma. Exposure to cigarette smoke is also a risk factor for asthma, with maternal smoking, both during pregnancy and after giving birth, as the most important cause of secondhand smoke exposure for children. • Obesity: Studies consistently show an association between body mass index (BMI) and asthma. Conversely, persons with initial asthmatic symptoms who are over 50 years of age, who have more than 20 pack years of smoking history, or who have extensive exposure to respiratory irritants (e.g., silica, asbestos)
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are less likely to be asthmatic, and more likely to have other health conditions causing the symptoms. The larger conversation of social determinants of health, emerging over the last decades, recognizes that poor, underserved, minority, and marginalized populations face life conditions that predispose them to disease. With regard to asthma, low socioeconomic status is associated with higher prevalence of asthma in U.S. and European studies. Weitzman et al. found that African-American children are at higher risk for asthma, not as a genetic predisposition to asthma, but instead related to the higher rates of poverty, larger family size, smaller homes, and lower birth weight and maternal age. A study in Boston, Massachusetts, of 2- to 3-year-olds identified positive correlations between low social support and exposure to violence in relation to asthma prevalence.
With the projected increase of urbanization on a global scale, the number of asthma sufferers will likely rise above 300 million.
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However, a unique aspect of asthma is that there are additional social determinants that affect the wealthier countries and populations of the world disproportionately. First is the increased exposure to respiratory irritants in houses made to be more energy efficient. As houses progress to become more sealed to air passage (into, or out of, the home), the exposure to aerosolized irritants, such as mold and dust, is thought to be a contributing factor in the rise of asthma rates in wealthier countries. Second, living in urban areas, regardless of race or socioeconomic status, is associated with a higher risk for asthma. Global Burden of Asthma Experts agree that asthma is an underrecognized public health and global health condition. An estimated 1 in 250 deaths worldwide is attributable to asthma, while in terms of disability adjusted life-years (DALYs) lost, asthma is comparable to diabetes, accounting for approximately 15 million DALYs each year. As mentioned before, rates of asthma are hard to accurately assess and compare, but the GINA prevalence estimates range from 0.7 percent to 18.4 percent. However, mortality rates due to asthma show a much different picture, with many developing countries at the top of the list. For instance, South Africa has an asthma mortality rate sixfold higher than England’s, despite the fact that England’s prevalence for asthma is twice that of South Africa. Beasley et al., in looking at the worldwide prevalence and etiology of asthma, found striking trends that may assist with the discussion of the global burden of this condition: (1) asthma prevalence is increasing worldwide, (2) asthma is more common in Western countries and in those that are English speaking, and (3) asthma is increasing in developing countries because of their westernization. With the projected increase of urbanization on a global scale, there is reason to believe that the number of persons with asthma will continue to increase from the current estimate of 300 million. Moreover, there are many barriers to reducing the burden of asthma globally, as outlined by Masoli and colleagues. First, poverty and poor health infrastructure make it hard to get the few evidence-based treatments to many of the world’s asthma sufferers. Second, asthma is not treated as a health priority, and is often overshadowed by more “deadly” diseases such as HIV/AIDS. Third, the disease is often misunderstood
by patients and clinicians alike; in the case of the latter, the disease-based focus, instead of treating patients based on their symptoms, is a barrier to optimal care. CURRENT APPROACHES Effective asthma treatment, on an individual and population level, is a current matter of debate. From the health perspective, there are still no curative treatments, and the effectiveness of various treatment regimens still has much room for improvement. From the economic perspective, a cost-effective treatment regimen is a challenge, particularly in the developing world. Politically, the issue does not raise the support needed to recruit adequate resources to prevent and treat the condition. Current practice focuses on preventing the severe exacerbations of asthma through the use of preventive treatment. Where the resources are there to provide medications, the current approach is to get patients treatments, predominantly inhaled beta-agonists or corticosteroids. There are well-defined treatment regimens based on the severity of patients’ symptoms. Diagnosis and treatment is particularly important for patients at the ends of the age spectrum, for whom asthma attacks are more likely to be fatal. In the case of severe asthma attacks, hospitalization may be required to manage the condition. On a population scale, societies have begun to implement policies that address environmental causes of asthma. Smoking bans, for instance, decrease the exposure to ETS, with expected effects on asthma rates. Workplace regulations requiring the monitoring of exposure to inhaled pollutants and the use of protective face gear also promise to decrease exposure to respiratory irritants. Meanwhile, housing ordinances against mold, asbestos, and other known pollutants make the home environment safer. At the same time, many persons and countries face an ever more polluted environment, with more persons exposed to the pollution due to urbanization and westernization. Currently, there is no precedent for large-scale, societal reforms to address asthma, but rather a more piecemeal approach to risk reduction. Future directions In looking to the future of asthma as a global disease, there is much work to be done to halt the rise of this condition and lower the mortality related to the con-
dition. While the former relies on preventive efforts, the latter relies on treatment of asthmatics to prevent severe consequences. However, both require the will of health leaders, politicians, and citizens to devote the resources necessary to address the problem. The executive summary of GINA includes recommendations for preventing and treating asthma so as to reduce the global burden of disease. First, these guidelines point to the need to recognize asthma as a leading cause of morbidity and mortality in the world. Until asthma is recognized as such, it will be difficult to muster resources to counter its effects. Second, there are areas where asthma research is badly needed. A system whereby asthma prevalence and mortality can be accurately measured across the world is essential. More basic research, meanwhile is needed into the causes and contributing factors behind asthma, as well as research to find more effective treatments. Critical to the effectiveness of such research efforts is the focus on solutions for both wealthy and less wealthy nations, as much of the current scholarship is oriented toward the former, making it of little use to the latter, where the proposed solutions are not financially viable. Third, GINA finds a great need in the area of providing consistent guidelines for the prevention and treatment of asthma to the global community. These should focus on the cost-effective regimens proven to reduce morbidity and mortality. Such guidelines, analogous to the research, must be adaptable for countries of varying wealth. Fourth, there must be improved access to essential medicines for lowand middle-income countries. Concurrent to this effort, further study into the noneconomic barriers (e.g., political issues or lack of health infrastructure) in accessing asthma medications is needed. Fifth, societies must address the environmental causes of asthma, including indoor and outdoor pollution, smoking, and work site exposures. This realm may prove the hardest and most expensive to address, but is the backbone to efforts to reduce the global burden caused by this disease. See also: Air Pollution; Allergy; Asthma in Children; En-
vironmental Health; Indoor Air Pollution; Smoking.
Bibliography. C.A. Aligne, “Risk Factors for Pediatric
Asthma,” American Journal of Respiratory and Critical
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Care Medicine (v.162/3, 2000); All about Vision, “Glossary of Eye Care Terms,” www.allaboutvision.com (cited April 2007); R. Beasley, et al., “Prevalence and Etiology of Asthma,” Journal of Allergy and Clinical Immunology (v.105, 2000); J.B. Berz, et al., “Prevalence and Correlates of Early Onset Asthma and Wheezing in a Healthy Birth Cohort of 2- to 3-Year Olds,” Journal of Pediatric Psychology (v.32/2, 2007); B. Burrows, et al., “Association of Asthma with Serum IgE Levels and Skin-Test Reactivity to Allergens,” New England Journal of Medicine (v.320/5, 1989); J.M. Drazen, “Pathogenesis of Asthma,” UpToDate, www.uptodateonline.com (cited April 2007); C.H. Fanta and S. Fletcher, “Diagnosis of Asthma in Adolescents and Adults,” UpToDate, www.uptodateonline.com (cited April 2007); Global Initiative for Asthma Management and Prevention, NHLBI/WHO Workshop Report, Pub. #95-3659 (National Institutes of Health, 1995); U. Hedlund, et al., “Socio-Economic Status Is Related to Incidence of Asthma and Respiratory Symptoms in Adults,” European Respiratory Journal (v.28, 2006); �������������� M.A. Jenkins, et al., “Validation ���������������������������������������������� of Questionnaire and Bronchial Hyperresponsiveness against Respiratory Physician Assessment in the Diagnosis of Asthma,” International Journal of Epidemiology (v.25/3, 1996); A. Litonjua and S. Weiss, “Epidemiology of Asthma,” UpToDate. www.uptodateonline.com (cited March 2007); A. Litonjua and S. Weiss, “Risk Factors for Asthma,” UpToDate. www.uptodateonline.com (cited March 2007); M. Masoli, D. Fabian, and S. Holt, “The Global Burden of Asthma: Executive Summary of the GINA Dissemination Committee Report,” Allergy (v.59, 2004); E.A. Mitchell, et al., “Socioeconomic Status in Childhood Asthma,” International Journal of Epidemiology (v.18, 1989); T.A. Platts-Mills, “How Environment Affects Patients with Allergic Disease: Indoor Allergens and Asthma,” Annals of Allergy, Asthma and Immunology (v.72/4, 1994); I.B. Tager, “Passive SmokingBronchial Responsiveness and Atopy,” American Review of Respiratory Disease (v.138/3, 1988); ���������������� B.G. Toelle, ��� et al., “Toward a Definition of Asthma for Epidemiology,” American Review of Respiratory Disease (v.146/3, 1992); K.B. Weiss, P.J. Gergen, and D.K. Wagener, “Breathing Better or Wheezing Worse? The Changing Epidemiology of Asthma Morbidity and Mortality,” Annual Review of Public Health (v.14, 1993); M. Weitzman, S. Gortmaker, and A. Sobol, “Racial, Social, and Environmental Risks for Childhood Asthma,” Archives of Pediatrics & Adolescent Medicine. (v.144/11, 1990); J.W. Yunginger, et al., “A Community-Based Study of the Epidemiology of Asthma.
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Incidence Rates, 1964–1983,” American Review of Respiratory Disease (v.146/4, 1992). Anthony Fleg University of North Carolina
Asthma in Children A chronic inflammatory disease of the lungs, asthma consists of the following: symptoms of cough, shortness of breath, wheezing, and chest tightness that can occur episodically, usually triggered by a specific environmental factor; narrowing of the airways that can be completely or partially reversible; and increased reaction to specific stimuli. Childhood asthma costs society an enormous amount, including 10 million missed school days, which in turn causes lost productivity due to parents’ missed work days, and $1.6 billion annually for treatment. The most common chronic childhood disease, asthma affects over five million U.S. children. From 1980 to 1996, asthma prevalence in the general U.S. population has increased more than 50 percent, with the largest increase reported in the younger-than-18 age group. In 2003, the Centers for Disease Control and Prevention found that lifetime asthma prevalence among children younger than 18 was 12.5 percent with a current asthma prevalence of 8.5 percent in this same age group. The increase in childhood asthma prevalence may be explained by several theories. One theory suggests that improved hygiene and a concomitant decrease in exposure to infectious pathogens have caused an imbalance in the normal immune response in children. It has also been suggested that an increase in indoor air pollution and an increase in exposure to indoor allergens (e.g., cockroaches, cats, dust mites, dogs, and molds) has led to more diagnoses of childhood asthma. Other explanations include early exposure to respiratory viral infections, enhanced host susceptibility (i.e., more premature infants surviving with chronic lung diseases), and a general increase in knowledge about asthma, both within the general population and the medical community, leading to more diagnoses of childhood asthma. Risk factors for developing childhood asthma include the following: living in an urban environment,
race, socioeconomic status, increased exposure to allergens, and smoking. Childhood asthma symptoms occur due to airflow obstruction when smooth muscles in the airways constrict in response to an inciting agent. Airway wall edema, accumulation of mucus in the airways, and the body’s inflammatory response also contribute to asthma symptoms. Reduced expiratory airflow occurs due to airflow obstruction. This can be diagnosed using pulmonary function tests. Additionally, if the obstruction is reversed after the patient is given a bronchodilator, then one can feel fairly certain of an asthma diagnosis. Airway hyperresponsiveness is another characteristic of asthma. This is defined as the degree to which the airways narrow in response to a nonspecific stimulus like methacholine, a drug used to induce bronchoconstriction; cold air; or histamine. Asthmatic children’s airways react to a lower dose of methacholine than those without asthma due to the hyperresponsivenss of their airways. Environmental allergens, viral upper respiratory infections, and air pollutants can also induce hyperresponsive airways. The degree of increased airway responsiveness correlates well with asthma severity in children. Last, chronic airway inflammation causes changes in the lungs at the onset of asthma symptoms, including the accumulation of an abundance of inflammatory cells such as eosinophils, lymphocytes, and mast cells. Mainstays of asthma treatment include short- and long-acting bronchodilators, inhaled and oral corticosteroids, and environmental control practices. Environmental control practices are defined as behavioral changes and practices to reduce symptoms and complications of asthma, including pet removal, cockroach extermination, frequent vacuuming, and other methods. Goals of therapy include the following: preventing symptoms, maintaining pulmonary function, maintaining normal daily activities, prevention of asthma exacerbations, minimizing emergency room visits, and providing optimal medical treatment with little or no side effects. The U.S. Department of Health and Human Services’s National Asthma Education and Prevention Program has published national guidelines for the diagnosis and management of asthma. These guidelines recommend standardized management and
Attention Deficit Disorder
treatment of asthma by severity: mild intermittent, mild persistent, moderate persistent, and severe persistent asthma. Severity of asthma increases with increasing frequency of symptoms and increasing use of medications. African-American and low-income children are disproportionately affected by asthma compared to other subpopulations of children. Due to asthma’s mixed etiology of biologic, environmental, and social factors, prevalence of childhood asthma is higher in these marginalized groups. Lack of accessibility to healthcare is a barrier to diagnosis and treatment of asthmatic children. A 2006 study by McDaniel et al. found that African-American children are 20 percent more likely to have asthma and to visit emergency rooms for their asthma care. SEE ALSO: Air Pollution; Allergy; Asthma; Environmental
Health; Indoor Air Pollution; Institute for Children’s Environmental Health; National Heart, Lung, and Blood Institute; Smoking. Bibliography. M. McDaniel, C. Paxson, and J. Waldfo-
gel, “Racial Disparities in Childhood Asthma in the United States: Evidence from the National Health Interview Survey, 1997 to 2003,” Pediatrics (v.117/5, 2006); National Heart, Lung, and Blood Institute, National Asthma Education and Prevention Program, Expert Panel Report 2: Guidelines for the Diagnosis and Management of Asthma (National Heart, Lung, and Blood Institute, 1997); Gregory Sawicki and Mark Dovey, “Chronic Childhood Asthma: Definition; Epidemiology; Pathophysiology,” UpToDate, www.uptodate .com (cited October 2006). Lindsay Kim Emory University
Attention Deficit Disorder Attention deficit disorder (ADD) is a cluster of behaviors that cause a child to underachieve in an academic setting, and also to behave poorly in spite of good parenting and schooling and a strong intellect. It was first diagnosed in 1902 by George Still, an English pediatrician, who noticed that a range of his patients, mainly boys, underwent certain behavioral difficulties
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from the age of 8. Most of these involved their being inattentive and overactive at school, often resulting in their getting into trouble with school authorities and sometimes with their parents. After the “Spanish” influenza epidemic of 1918–1919, which killed some 20 million people worldwide, many survivors were left neurologically impaired by the disease and/or attempts to treat it. Some later developed Parkinson’s disease, but long before this, they showed symptoms of brain dysfunction. This led researchers to conclude that ADD was a result of mild brain damage. Initially, there was no treatment, but in 1937, a number of children in children’s homes in Britain were given the drug amphetamine to try to alter their behavior. It worked, leading to the drug being used to treat children suffering from ADD starting in the 1950s. Throughout the 1950s and the 1960s, researchers tried to categorize the different types of behavior associated with ADD. These included minimal brain damage, all the way to minimal brain dysfunction. This in turn led to some people conducting extensive research into the dominance of the eye, foot, and hand, and also the movement of fingers, tests that started to become popular in the United States. In 1973, Dr. Ben F. Feingold, who had been an associate professor of allergy at the Los Angeles Children’s Hospital, suggested that there could be a relationship between diet and ADD. He believed that it was possible that children who ate food with too many additives could have an increased risk of suffering from ADD. In response to his claims and the press coverage they received, the U.S. government set up committees to see whether there was any truth in Feingold’s theory. Dr. Feingold had originally felt that diet could be the cause of as many as half the cases of ADD, but the extensive tests showed that it could be said to be a cause in as few as 5 percent of the children who suffered from ADD. Soon afterward, attention was drawn to the stimulant methylphenidate (Ritalin) which had been introduced in 1957. Many tests on it had shown that it was possible that it could be used to treat children with ADD, and it is now used for such treatment on a relatively routine basis. The reason why George Still began to notice that boys were suffering from ADD from the age of 8 had to do with schooling, with the need for many children, from that age, to be able to concentrate in classrooms.
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As they get older, children who fidget and who are too impulsive and insatiable—often being socially out of tune—quickly draw attention to themselves. It often coincides with the children underperforming at school, with the worst cases being distracted and distracting, and also disruptive. Parents of such children are now encouraged to make an appointment with a child psychologist, and the child is then monitored more closely by the school. If a child is diagnosed with ADD, action has to be taken by parents, siblings, and teachers. Unfortunately, parents often feel unnecessarily guilty at the diagnosis. Parents need to accept that ADD is a physical condition that should be treated carefully and thoughtfully; they need to avoid getting angry as the child draws attention to himself or herself. Researchers have found that fathers are often better at dealing with ADD children than mothers. Most parents are encouraged to establish a routine, to communicate clearly with the child, and to watch for events that might trigger a negative response. They also have to monitor behavior by siblings, and by their children at parties and other public events. For teachers who have to deal with suspected cases of ADD, it has been found to be most effective if they are notified as soon as possible so that they can be aware of the issues involved. One effective way of dealing with children suffering from ADD involves seating them in a good place in classroom that reduces their chances of being distracted or distracting others. There has to be regular communication between teacher and parent, and the children have to be involved in some part of the decision-making process, with their treatment explained to them carefully. Remedial help is important, as is attending a school with smaller classes, which will mean that the teacher can focus more closely on all the children. It is also common for many children suffering from ADD to be taught at a slower pace, or for them to repeat a year of schooling to ensure that they get a good grounding. Teachers must be encouraging, flexible, firm at times, and, above all, patient. Most children with ADD are totally unaware that there is anything abnormal about their behavior. They do not see themselves necessarily as being as socially inept as others might view them. Since many ADD children having poor planning skills, as they move through secondary school, they often have
more problems. There may be comments on their handwriting, as well as on their thought processes in essays. However, it is possible for a student to do well in one subject or group of subjects even while faring poorly in others. Research has also gone into better diets for ADD children, with many urged to eat more fruit and drink fewer soft drinks, which are high in sugar. Many doctors and psychologists prescribe Ritalin to children who suffer from ADD, and research points to this being an effective way of managing the disorder. See also: American Academy of Pediatrics; Attention
Deficit Hyperactivity Disorder; Child Mental Health; Psychology; Psychiatry. Bibliography. Thomas Armstrong, The Myth of the
A.D.D. Child (Plume, 1997); Christopher Green and Kit Chee, Understanding A.D.D.: Attention Deficit Disorder (Doubleday Books, 1994); William Sears and Lynda Thompson, The A.D.D. Book: New Understandings, New Approaches to Parenting Your Child (Little, Brown, 1997). Justin Corfield Geelong Grammar School, Australia
Attention Deficit Hyperactivity Disorder Attention deficit hyperactivity disorder, also known as ADHD, is a relatively common behavioral disorder affecting 3 to 7 percent of the school-age population. It is a persistent pattern of inattention and/ or hyperactivity-impulsivity that is not typically observed in individuals of a comparable age. Behavioral characteristics of the disorder are observable from the preschool years onward. Assessment requires a careful, multisource approach as ADHD must be differentiated from a wide range of other psychiatric, developmental, and medical conditions. The effects of ADHD are life encompassing and, without treatment, may lead to a wide range of severe impairments including poor academic outcome, work difficulty, social rejection, driving accidents, increased risk of smoking, alcohol and drug abuse, and poor self-esteem.
Australia
Classification of what constitutes ADHD has changed over the past 20 years based upon revisions of the Diagnostic and Statistical Manual of Mental Disorders (DSM), the criteria used to define the disorder. Currently, DSM-IV notes specific criteria for diagnosing subtypes of ADHD. The main symptoms consist of inattention, hyperactivity, and impulsivity, and have been present before the age of 7. The symptoms are present in two or more settings, lead to significant impairment, and cannot be better accounted for by another psychiatric disorder. Those diagnosed with ADHD are also more likely to have other developmental, social, and health problems. ADHD is commonly associated with oppositional defiant disorder, conduct disorder, depression, and anxiety. A significant number of children and adolescents will continue to have some symptoms of the disorder into adulthood. The actual cause of ADHD is not known but is believed to include multiple factors. Explanations can be simply divided into biological and environmental. Biological explanations include genetics and brain structure, while environmental includes parenting and diet. Studies have demonstrated that cases of ADHD tend to run in families and suggest that transmission may be partly mediated by genetics. Current studies are looking at specific dopamine genes as well as how brain structure relates to behavior. Evidence for environmental influences on ADHD have been noted in intervention studies demonstrating improvement in symptoms when parents have been taught alternative parenting skills (this does not imply that parents of children with ADHD are bad parents). Food additives, refined sugars, and fatty acid deficiencies have all been associated with ADHD symptoms; however, the clinical importance of dietary change as a means of treating ADHD symptoms remains uncertain. Treatment of ADHD requires special consideration of the core symptoms and also family and social factors. The largest study of long-term treatment of ADHD to date is known as the Multimodal Treatment Study of Children with ADHD. This study found that stimulant medications used as the sole form of treatment led to significantly better results of core symptoms than behavioral therapy alone. On the other hand, a combination of medication and behavior therapy led to the best overall improvement in symptoms of ADHD. The American Academy of Pediat-
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rics and the American Academy of Child and Adolescent Psychiatry have published treatment guidelines for ADHD. Both support that treatment should be based on specific target symptoms and goals. Stimulant medications (methylphenidate and amphetamine products) are a first-line treatment recommendation for most children with ADHD, often in combination with behavioral therapy and other forms of treatment. In addition, special educational services are often required for the ADHD child. Two federal laws guarantee a child’s right to receive such services and are noted under Section 504 of the 1973 Vocational Rehabilitation Act, and a 1991 addendum to the 1990 Individuals with Disabilities Education Act (IDEA). SEE ALSO: American Academy of Pediatrics (AAP); At-
tention Deficit Disorder; Child Mental Health; Psychology; Psychiatry. Bibliography. D. Daley, “Attention Deficit Hyperactiv-
ity Disorder: A Review of the Essential Facts,” Child: Care, Health and Development (v.32, 2006); Diagnostic and Statistical Manual of Mental Disorders, 4th ed. (American Psychiatric Association, 2000); Michael Reiff, ADHD: A Complete and Authoritative Guide (American Academy of Pediatrics, 2004). Debra A. Willsie, D.O. University of Missouri–Kansas City
Australia As the 19th-richest country in the world, Australia has a per capita income of $31,600 and universal access to healthcare. According to the United Nations Development Programme (UNDP) Human Development Reports, Australia has the third highest standard of living in the world. Funding for healthcare is derived from a number of sources that include national, state, and territorial governments; private health insurers; and individuals. Government spending on health is high, with 14 percent of total expenditures targeted for this area. Just under 10 percent (9.5 percent) of the Gross Domestic Product (GDP) is used for healthcare, and the government allots $2,874 (international dollars) per capita to cover the costs of healthcare. Government
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spending on health accounts for 67.5 percent of total spending. The private sector provides 32.5 percent of health expenses, and 67.80 percent of that amount comes from out-of-pocket payments. There are 2.47 physicians, 9.71 nurses, 1.10 dentists, and 0.72 pharmacists per 1,000 population in Australia. Government commitment to healthcare is strong in Australia. Between 1960 and 1990, the government nearly doubled medical spending in response to advancing medical and pharmaceutical technologies. Medicare was introduced in 1984. This program, which is funded through tax revenue, covers all Australians. Medicare includes a pension plan, and the cost of all doctor visits is reimbursed. Treatment in public hospitals is entirely free. Critics contend that in the 1990s, services to the poor were cut after the election of John Howard as prime minister. Dental services, which had been free for the disadvantaged, were shifted to dental clinics. Critics also contend that lifestyles of the elderly declined, creating a group of newly poor individuals. Healthcare in Australia is the joint responsibility of state and territorial governments, which provide community and public healthcare that focuses on women’s and children’s health, oral health, occupational health, and disease control. Services include home care, immunization programs, and preventive care. Oversight of issues affecting public health is the responsibility of local governments, and inspections of facilities, training, waste disposal, and water supplies are regularly conducted. At the national level, funding is also available for medical services and pharmaceuticals, aged care, education of medical professionals, and health research. Australia’s population of 20,264,082 people enjoys a life expectancy of 80.5 years, the ninth highest ranking among the world’s nations. Literacy is almost universal, and only 1 percent of the population over the age of 15 is unable to read and write. Enrollment in school in both the primary and secondary levels is higher than 100 percent. Australia has no identifiable poverty rate, but 5.1 percent of the labor force is unemployed. There is some income disparity in Australia, which ranks 35.2 on the Gini Index of Human Inequality. While the poorest 10 percent of the population share only two percent of resources, the richest 10 percent claims 24.4 percent. The entire population has access to safe drinking water and improved sanitation.
Some 76 percent of Australian women use some form of birth control. On the average, women give birth to 1.76 children each. All births are attended by skilled professionals, and all women receive ante natal care. The adjusted maternal mortality rate is eight deaths per 100,000 live births. Rising interest in women’s health concerns in the 1960s and 1970s focused attention on reproductive issues and on other factors that affect women’s health. Women were reeducated to see pregnancy, menopause, and other bodily functions as normal occurrences rather than medical conditions. In the 1990s, the interest in women’s health spawned a men’s health movement, which focused on the fact that life expectancy for Australian males is 77.64 years as compared to 83.52 years for females. A new body of literature emerged focusing dealing with male involvement in industrial and traffic accidents and on the typical male reluctance to visit physicians. Currently, Australia has an infant mortality rate of 4.63 deaths per 1,000 live births. This ranking places Australia among the 20 countries with the lowest infant mortality rates in the world. Between 1990 and 2004, infant mortality dropped from eight to five deaths per 1,000 live births, and under-5 mortality declined from 10 to six deaths per 1,000 live births. Seven percent of infants are underweight at birth, but the vast majority of Australian children are healthy. Ninety-seven percent of infants are immunized against diphtheria, pertussis, and tetanus (DPT1), 95 percent against hepatitis B and Haemophilus influenzae type B, and 93 percent against measles. Eight percent of infants fail to receive DPT3 and polio vaccinations. Australia has not escaped the HIV/AIDS epidemic that has swept much of world, and the country has a 0.1 percent adult prevalence rate. Around 14,000 people are currently living with this disease, which has proved fatal to approximately 200 Australians. Concern over the HIV/AIDS epidemic led Australia to develop an internationally praised program in which social scientists cooperated with gay advocacy groups and officials of the former Labour government to promote HIV/AIDS awareness and prevention. Other communicable diseases have also caused some concern in Australia. Legionnaires’ disease surfaced in Australia in spring 2000, and an outbreak of severe acute respiratory syndrome (SARS) occurred in 2003 as part of a multicountry outbreak.
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The Australian medical community has expressed grave concern over chronic health conditions that are a result of lifestyle and behavior. Obesity is considered endemic, and 20 percent of the population continues to smoke despite efforts to educate the public about the dangers of the practice. In order to produce a healthier population, Australia has developed a National Research Priority that promotes improved health of infants, children, and the aged; preventive healthcare throughout life; and strengthening of the social and economic fabric that promotes well-being. See also: Healthcare, Asia and Oceania. Bibliography. Central Intelligence Agency, “Australia,”
World Factbook, www.cia.gov (cited December 2006); Commission on the Status of Women, “Australia” www.un.org/ womenwatch (cited December 2006); Department of Foreign Affairs and Trade, “Health Care in Australia,” www .dfat.gov. au (cited December 2006); Institute of Health and Welfare, “Australia’s Health 2004,” www.aihw.gov.au (cited December 2006); Peter Saunders and James Walter, eds., Ideas and Influence: Social Science and Public Policy in Australia (University of New South Wales Press, 2005); Hugh Stretton, Australia Fair (UNSW Press, 2005); United Nations Children’s Fund (UNICEF), “Australia,” www.unicef.org (cited December 2006); World Bank, “Australia Data Profile,” devdata.worldbank.org (cited December 2006); World Health Organization, “Australia,” www.who.int (cited December 2006). Elizabeth R. Purdy, Ph.D. Independent Scholar
Austria Austria has the 14th-highest standard of living in the world according to the United Nations Development Programme (UNDP) Human Development Reports, and Austrians have easily available access to healthcare and other social services. With a per capita income of $32,500, Austria ranks as the 17th-richest country in the world. The official poverty rate is 5.9 percent, and the government records unemployment at 5.2 percent. Income is more evenly distributed than in many countries, and Austria ranks 31 on the Gini Index of Human Inequality. The bottom 10 percent
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of the population share 3.3 percent of total resources, and the richest 10 percent claim 22.5 percent. Commitment to healthcare has a long history in Austria, and social security, dating back to 1909, is a major element of the healthcare system. The program covers the elderly, the disabled, and survivors of dead workers. Social security is financed by monthly payments from wage earners and salaried employees (10.25 percent of earnings), employers (12.55 percent of payroll), and the government, and is administered by the Federal Ministry of Social Security, Generations, and Consumer Protection. The Health Promotion Law, enacted March 27, 1998, serves as an overall guideline for the provision of healthcare in Austria. The stated purpose of the law is to preserve, promote, and improve the health of Austrians. Implementation of healthcare depends on partnerships between central and lower-level government and on the participation of the citizenry, employers, private insurers, and nongovernmental organizations (NGOs). Maternity and sick leave have been provided for Austrians since 1888. In 1974, wage earners earned the right to cash benefits while on leave, and workers may earn 100 percent of their salaries for up to 12 weeks. If this coverage is exhausted, other programs take over to furnish income supplements. Mothers on maternity leave receive full salary up to eight weeks before birth and for eight weeks after the expected birth date of a child. Fathers also receive full benefits under family leave provisions. The government contracts with doctors, hospitals, and pharmacists to provide maternity and dental care, hospitalization, expenses for medications and medical devices, preventive care, home care, and transportation to the site where medical care is located. Workers pay a low percentage of the costs for themselves and their dependents. Government spending on health is high in Austria, and the government allocates 13 percent of total government expenditures for healthcare. The government spends 7.5 percent of the total Gross Domestic Product (GDP) in this area, allocating $2,306 (international dollars) per capita to meet health expenses. Some 67.6 percent of all health expenses are covered by the government, and 65.8 percent of that amount is designated for social security. The private sector accounts for 32.4 percent of total health expenses, and 59.20 percent of that amount is derived from out-of-pocket expenses. There are 3.38 physicians, 9.38 nurses, 0.21 midwives,
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0.50 dentists, and 0.60 pharmacists per 1,000 population in Austria. Most of the population of 8,192,880 live in the lowlands of the east because other areas are impassable in the winter. Poor soil in these areas makes agricultural activity unfeasible. Austrians enjoy a life expectancy of 79.07 years, and the country ranks 27th in the world in this category. On average, females outlive males by six years. Literacy stands at 98 percent in Austria, and more than 100 percent of students attend both primary and secondary school. The entire population has access to safe drinking water and improved sanitation. More than half the female population uses birth control, and the fertility rate in Austria is predictably low at 1.36 children per female. All births are attended by trained personnel, and all women receive prenatal care. The maternal mortality rate is only four deaths per 100,000 live births. The Federal Ministry of Health and Women’s Issues subsidizes six health centers around Austria that were created to minimize existing health inequalities among women. With an infant mortality of 4.6 deaths per 1,000 live births, Austria has the world’s 18th lowest ranking. Between 1990 and 2004, both infant and under-5 mortality were halved, falling from eight to four deaths per 1,000 live births and from 10 to five deaths per 1,000 live births, respectively. Seven percent of all children are underweight at birth, but overall, Austrian children are extremely healthy. Infant immunization rates are lower than might be expected with such a high standard of living. Around 97 percent of infants receive the diphtheria, pertussis, and tetanus (DPT1) vaccine, but percentages drop to 83 percent for DPT3, polio, hepatitis B, and Haemophilus influenzae type B. Measles immunization rates are even lower (74 percent). Although the mortality rate is low (less than 100 people), Austria has not escaped the HIV/AIDS epidemic (0.3 percent adult prevalence rate). Around 10,000 people are currently living with the disease. In 2004, Austria experienced an outbreak of human influenza A/H3N2. SEE ALSO: Healthcare, Europe.
Central Intelligence Agency, “Austria,” World Factbook, www.cia.gov (cited January 2007); Commission on the Status of Women, “Austria,” www. Bibliography.
un.org/womenwatch (cited January 2007); Spencer Di Scala, Twentieth Century Europe: Politics, Society, Culture (McGraw-Hill, 2004); Sandra Halperin, War and Social Change in Modern Europe: The Great Transformation Revisited (Cambridge University Press, 2004); Martin A. Levin and Martin Shapiro, eds., Transatlantic Policymaking in an Age of Austerity: Diversity and Drift (Georgetown University Press, 2004); Social Security Administration, “Austria,” www.ssa .gov (cited January 2007); Peter Thaler, The Ambivalence of Identity: The Austrian Experience of Nation-Building in a Modern Society (Purdue University Press, 2001); United Nations Children’s Fund (UNICEF), “Austria,” www.unicef .org (cited January 2007); World Bank, “Austria Data Profile,” devdata.worldbank.org (cited January 2007); World Health Organization, “Austria,” www.who.int (cited January 2007). Elizabeth R. Purdy, Ph.D. Independent Scholar
Autism Autism is a neurodevelopmental disability that cannot be diagnosed by any specific biological or medical test. It is organic rather than genetic, developing during the prenatal period. Autism is characterized by a triad of symptoms that include difficulties in social interaction with others, problems communicating with others, and patterns of restrictive, repetitive, and stereotypical interests and activities that are evident before the age of 3. The disorder popularly referred to as autism generally describes the most common form of autism. There is a group of other disabilities of varying severity that are also classified as autism spectrum disorders (ASD). Diagnoses of autism are based in large part on observation. In its most common form, autism is apparent in infancy. In other forms, it may surface after months or even years of apparently normal development. Chromosomal/DNA testing may be useful, particularly if autism occurs along with other disorders such as Fragile X, Angelman syndrome, William’s syndrome, tuberous sclerosis, Landau-Kleffner syndrome, or fetal alcohol syndrome. Approximately 35 percent of children included in autism studies have been diagnosed with epilepsy or
unusual electrical discharges in the brain. The likelihood of seizures increases as individuals reach adolescence and adulthood and may indicate a lower life expectancy. The ratio of males to females in autistic diagnoses is 4.3:1. Early research centered on schoolage children, but tests have now been developed that can identify autistic tendencies in infants. Early identification and therapy are important for optimal development of autistic children. In February 2007, the Centers for Disease Control and Prevention in Atlanta, Georgia, announced in its Morbidity and Mortality Weekly Report that between 2004 and 2007, the prevalence of autism in the American population rose from 1 in 166 to 1 in 150. The World Health Organization (WHO) estimates the global prevalence of autism at 2 to 6 in 1,000. Although diagnosis and treatment of autism is common in industrialized nations, autism is not always understood in developing countries. Without the assistance of international organizations such as WHO and the Global Autism Project, many families in developing countries would be on their own. According to popular belief, many individuals with autism have superior intelligence; the term idiot savant is well established in popular culture, in part because of the Oscar-winning film Rain Man (1988), in which Dustin Hoffman played savant Raymond Babbitt. Most studies do not support the theory of superior ability across the spectrum of autism disorders. According to one study of 51 children, 10 percent of the sample tested in the normal range, while only one exhibited superior intelligence. Other studies have revealed that while from one-third to one-half of autistic children demonstrate average or above-average intelligence, the remainder fall into the mentally dysfunctional range. Those with the highest levels of intelligence are often diagnosed with “high-functioning autism.” While individuals with autism develop varying levels of abilities, they will have the disorder for the rest of their lives. In addition to autism, disorders classified under the umbrella of autism spectrum disorders include Asperger’s syndrome, pervasive development disorder not otherwise specified (PDDNOS), childhood disintegrative disorder (CDD), and Rett syndrome. All of these conditions are classified as pervasive development disorders (PDD) by both the American Psychiatric Association and WHO, and all are indicative of abnormalities in social in-
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teraction and language or in symbolic imaginative play before the age of 3. Since 1951, the American Psychiatric Association has used its own system, DSM-IV-TR, to classify disorders according to distinct differences in behavior and learning patterns. At the global level, the International Diagnostic System of Mental and Behavior Disorders (ICD-10) is used to identify similar disorders. Autism and Development The absence of normal alliterative baby sounds, the failure to engage in social smiling, a disinclination to respond to familiar voices, and disinterest in following objects within eye range are all indicative of the most common form of autism in young infants. The autistic infant may not show the marked preference for parents and other caregivers that is evident in most infants. An autistic infant may also be unusually quiet, leading parents to suspect that their child might be deaf. Unlike deaf infants, however, autistic infants do not look directly into the faces of others and may break eye contact immediately. Autistic infants are less likely than others to call attention to themselves. They may not engage in age-appropriate play and will not join in games such as pat-a-cake and peek-a-boo. The autistic infant may not respond to his/her own name. He or she may not develop the ability to pay attention to more than one person, object, or event at a time. Since routine is so important to autistic children, the most frequent reactions may arise when the child wants someone to do or not to do a particular thing. For instance, the child may take an adult’s hands and push them toward a particular object. An autistic child may become unreasonably upset if furniture is moved or if an alternate route is taken to a familiar place. The failure to communicate in appropriate ways often leads to behavior that is considered difficult. Between 1 and 2 years, the symptoms associated with autism become more noticeable. The child may engage in repetitive motor movements such as hand flapping, body rocking, head weaving, and facial grimaces. Part of the normal development of infants and children involves learning social skills through imitation, but the imitative ability is impaired in the autistic child. Unlike other children who may use a cardboard box for a train or a stick for a sword, autistic children do not engage in symbolic play. They tend to
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fixate on parts of an object rather than playing with the object according to its design. An autistic child may be fascinated with the wheels of a toy car or an airplane, for instance, but never play with such toys in ways that mimic the use of the actual object. Researchers do not understand whether this behavior is caused by a lack of understanding or ability, or a combination of the two. Some autistic children fixate on particular objects such as stop signs, carpet lint, and Disney characters. Others may turn a jigsaw puzzle over before putting it together or spend long periods placing objects in a row. Communication problems are present to some degree in all autistic individuals. The first signs of autism may be an infant’s failure to develop age-appropriate speech and to respond to the voices of others. The autistic child may grunt in unusual ways. One-third of autistic children never develop oral speech. Some who talk may be unable to engage in ordinary social communication. The autistic child may have a limited vocabulary during later infancy, only to lose it. Language skills regress in 20 percent of autistic children during the second year. However, most autistic children do not lose adaptive and motor skills that have developed. In one study, 40 percent of a group of autistic children from 18 to 36 months had no functional speech as compared to 10 to 15 percent of this age group in the general population. Those who could speak rarely developed the ability to use word combinations. Despite earlier delays, some autistic children begin speaking in the preschool years. Speech in autistic children may be stereotypical, repetitive, or idiosyncratic. It may also be abnormal in pitch, intonation, rate, rhythm, and stress, often taking on monotone or sing-song intonations. Echolalia, the practice of repeating the speech of others, is common among verbal autistic children. Echolalia may be either immediate, repeating speech that has just been heard, or delayed. In the latter case, an autistic child may repeat words heard on television or a video, mimicking exact tones and accents, or speech may appear robotic. Because of the repetition, children who exhibit echolalia may confuse pronouns, referring to themselves as “you” and others as “I,” and the child may fail to consciously develop speech based on grammatical rules as other children do. Autistic children tend to be literalists. For instance, instead of hurrying as most children would do when instructed
to “hop to it,” an autistic child might literally hop up and down. Autistic children may also lack an understanding of appropriate speech and fail to understand idioms, figures of speech, and abstractions. Sign language has been successfully used with autistic children, although young children may lack the motor skills needed to form signs correctly. It is recommended that all individuals who regularly come into contact with a signing autistic child learn common signs. Some teachers who work with autistic or deaf children have also adopted particular signs for use with other children. For instance, the sign for “bathroom” is shaped by placing the thumb between the second and third fingers and moving the hand up and down. Many teachers have found that teaching this sign to all children in a class is less disruptive than repeated requests to go to the rest room. Other Autism Spectrum Disorders There are distinct indicators and patterns associated with all of the disorders identified as autism spectrum disorders. Asperger syndrome was first described independently by Austrian-American psychiatrist Leo Kanner (1894–1981) and by Austrian pediatrician Hans Asperger (1906–80). The prevalence of Asperger’s is 1 in 300, and the ratio of male to female is 10:1. Unlike typical autism, infants with Asperger’s usually develop normally, exhibiting neither language delays nor communication impairment. Indeed, they often talk incessantly. They may have trouble with motor skills, however, and often appear clumsy and uncoordinated. They do not always understand special relationships, and their handwriting may be illegible. Children with Asperger’s tend to be teased and bullied by classmates. As they reach adulthood, individuals with Asperger’s often fail to develop age-appropriate language and communication skills. They tend to have extensive vocabularies. They are likely to know a lot about subjects of great interest and are willing to talk about them for hours. They have a tendency to talk “at” others rather than conversing with them. Individuals with Asperger’s may not develop nonverbal communication skills, however, and often fail to understand abstractions. Like other autistic individuals, they rarely engage in ordinary eye contact. Facial expressions may be classified as unusual or inappropriate. Individuals with Asperger’s tend to have difficulty keeping friends. They gravitate toward
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From 2004 to 2007, the prevalence of autism in the American population rose from 1 in 166 to 1 in 150. The most common form of autism may first appear as a lack of social smiling, not looking directly into the faces of others, and breaking eye contact, among other symptoms.
those who share similar interests but often alienate them because they fail to pick up on social cues. An inherent disinclination to break rules generally makes the adult with Asperger’s an upstanding citizen. Childhood disintegrative disorder (CDD) was first identified in 1908 by Theodor Heller, a Viennese special educator. Also known as Heller’s syndrome, the disorder disproportionately affects males. The disorder is rare, and the exact prevalence is unknown. A child with CDD may appear to be developing normally. At some point between the ages of 2 and 10, however, the child begins to immediately and significantly regress in areas that include bladder and bowel control, adaptive behavior, expressive or receptive language, motor skills, social interaction, and play skills. A diagnosis of Asperger’s requires that the child also exhibit at least two of the triad symptoms associated with autistic behavior: difficulties in social interaction, communication problems, and restricted
or repetitive behaviors and interests. Social skills in children with CDD seem to suffer more than those in individuals with typical autism, and the social deficits seem to be more severe. Some studies have suggested that children with CDD are prone to epilepsy as they age, tending to have reduced life expectancies. Rett syndrome, which is a rare disorder with a prevalence rate of one in 15,000, is distinctly different in origin from other autistic disorders because it is a genetic disorder linked to a specific gene defect. Behavior patterns are similar to those common in traditional autism. Rett syndrome was first identified in 1966 by Andreas Rett (1924–97). Most individuals with the disorder are female because the gene defect is usually fatal in males. Rett syndrome is characterized by six to 18 months of normal development followed by an abrupt loss of acquired skills. This loss may affect both language and motor function. The child may become uncoordinated, eventually los-
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ing all ambulatory ability. The circumference of the head begins to decrease between 5 and 48 months, and control of the hands diminishes between 5 and 30 months. Some children with Rett syndrome remain at one of the early stages without losing all skills that were developed before the disorder surfaced. Others become mentally impaired and develop severe communication deficits. Individuals with Rett syndrome have normal life expectancies. Autistic disorders not otherwise specified are categorized under an umbrella term, pervasive development disorder not otherwise specified (PDD-NOS). There are no actual diagnostic criteria for this disorder. Diagnosis is based on observation of abnormal peer relations and unusual sensitivities. Individuals with this disorder are generally identified later than other autistic children, and they tend to be higher functioning. History and research There is evidence to suggest that autism has been present in humankind for thousands of years. Born into societies where disabilities were misunderstood and often equated with evil, research suggests that most of these children were abandoned in remote places and left to die. In 1725, a child of approximately 12 years of age was found living in the woods in Germany. He became known as Peter the Wild Boy of Hanover. Peter received so much attention that he was taken to Britain, and King George I (1660–1727) and Queen Caroline (1683–1737) became interested in him. Although he never learned to speak, he loved music and would respond to it by humming. In 1799, French physician Jean Marc Gaspard Itard (1775– 1838) brought world attention to Victor, a child who had apparently been brought up by wolves. Itard posited that Victor had one of the forms of autism that was not identifiable in infancy. He believed that Victor had been at least 3 or 4 when he was abandoned, because he was able to survive. Itard was never able to help Victor to socialize. The first schools for children with special needs were not established in the United States until the 1820s, and they generally focused on education for the blind and deaf. When compulsory education laws were enacted at the end of the 19th century, the laws did not apply to children with disabilities. Except for some assistance provided by the private sector, par-
ents were expected to deal with disabled children on their own. At the turn of the 20th century, the term autism was often associated with schizophrenia. By mid-century, a truer understanding of the disorder developed when Leo Kanner of Johns Hopkins University became the first physician to apply the term as it is understood today. While working with a group of 11 children who were exhibiting abnormal patterns of development, Kanner observed that the children were deficient in socialization and language skills and he described their behavior as extremely rigid. Although much of his diagnosis was accurate, Kanner’s small sample and the scarcity of existing information on autism led him to make a number of incorrect assumptions. He determined that the disease was not congenital, that it was psychological rather than medical in origin, that all autistic children had higher-than-normal intelligence, and that it was most likely to affect children who came from families of high economic status. Around the same time Kanner was working with autistic children in Baltimore, Maryland, Hans Asperger was seeing four boys between the ages of 6 and 11 at the University Pediatric Clinic in Vienna. He noted that the boys had sophisticated language but exhibited unusual eye contact, gestures, and voice tones and stresses. While of apparently normal intelligence, the boys all lacked age-appropriate social skills and were frequently teased and bullied. All experienced motor problems that made them physically awkward. They were described as egocentric, noncompliant, negative, and obsessive. All difficulties had surfaced during the second year after normal development during infancy. What Asperger diagnosed as autistic psychopathy subsequently became known as Asperger’s syndrome. Debate continues on the differences and similarities between high-functioning autism and Asperger’s. From the 1940s to the 1960s, researchers believed that autism was caused by unloving and neglectful parents who forced a child that had been born healthy to turn inward. As the primary caregivers, mothers were particularly assumed to be at fault. In 1967, Austrian-American writer and child psychologist Bruno Bettelheim (1903–90) coined the term “refrigerator mother” to explain how autism developed. Instead of treating autistic children, all their mothers and some of their fathers were pushed into psychoanalysis to learn to be “better” parents.
Despite the fact that many parents and caregivers sensed that a child was not developing according to proscribed patterns, in the past parental fears were often dismissed by professionals who had little or no experience in diagnosing ASD. One large-scale study in 1977 revealed that only 10 percent of parents who sought help with developmental problems were given an immediate diagnosis. One-fourth were told not to worry, and another 10 percent were told to take a wait-and-see attitude. Between 1966 and 1991, the median prevalence of autism in the general population was reported as 4.4 per 10,000. By 1992 that prevalence rate had climbed to 12.7 per 10,000. The increase may have been due to increased awareness, better diagnostic instruments, and broader diagnostic criteria rather than to actual increases in the number of children born with autism. Some researchers, parents, and activists insist that environmental factors and vaccinations are responsible for the increased prevalence. These suppositions have neither been proved nor disproved. Helen Tager-Flusberg, a professor of anatomy, neurobiology, and psychology at Harvard University, was the first to identify a basic pattern of development for children with ASD. Much of her research has been conducted under the auspices of the Boston University School of Medicine’s Lab of Developmental Cognitive Neuroscience, which has been engaged in studying autism in both children and adults since the early 1980s. The child study examines children between the ages of 18 months and 18 years, while the adult study focuses on individuals between the ages of 18 and 30. The multidisciplinary research team includes scholars from the fields of psycholinguistics, clinical psychology, psychiatry, speech-language pathology, occupational therapy, special education, and biology. There are a number of measures employed to test the abilities of autistic children. The Autism Diagnostic Observation Scale uses a scale of 0 to 3 to test speech and comprehension in children who are preverbal or who speak in single words or simple phrases. Rendering both standard and age-equivalent scores, the Mullen Scales of Early Learning measures development from birth to 68 months by examining visual reception, repetitive language, expressive language, and fine and gross motor skills. The MacArthur-Bates Communicative Development Inventory tests the ability of
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infants to engage in words and gestures through parental information about what words are understood and the use of gestures and play. The Communication and Symbolic Behavior Scales-Development Profile tests children by tempting them to engage in social interaction. The Vineland Adaptive Behavior Scales Survey Form is administered to a child’s regular caregiver by trained assistants who gather information on the autistic child’s ability to communicate and access motor skills. They then develop a profile of the child’s social skills and day-to-day behavior. The Autism Behavior Checklist is completed by parents, teachers, and caregivers who observe a child on a regular basis. It is then interpreted by trained personnel. The checklist, which has been used with children as young as 3 years, is composed of 57 questions designed to test abilities in five areas: sensory, relating, body and object use, language, and social and self-help. Government and celebrity involvement The National Institutes of Health (NIH) established guidelines for the evaluation and treatment of autism in 1996. The next year, two of the Children’s Environmental Health Centers were instructed to focus on autism, and an international network was established to promote research on autism through the Collaborative Programs of Excellence in Autism (CPEA). Working through the NIH, the American government initiated Studies to Advance Autism Research and Treatment (STAART), which focuses on diagnosis, early detection, prevention, and treatment. The STAART network is made up of eight autism centers established at Boston University; Kennedy Krieger Institute; Mount Sinai Medical School; University of California, Los Angeles; University of North Carolina, Chapel Hill; University of Rochester; University of Washington; and Yale University. Current studies include Effectiveness of Early Intervention with Fluoxetine in Enhancing Developmental Process in Children with Autism; Early Characteristics of Autism; Diet and Behavior in Young Children with Autism; Citalopram for Children with Autism and Repetitive Behavior; and Relationship Training for Children with Autism and Their Peers. Funding for autism research was also included in the Children’s Health Act of 2000. Six years later, Congress passed the Combating Autism Act (P.L.
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109-416), which authorized a five-year cycle of support for autism research by authorizing $920 million to be earmarked for biomedical and environmental research, surveillance, awareness, and early identification. Distribution of funds is the responsibility of the Department of Health and Human Services. Other congressional bills dealing with autism have also been introduced, including the Expanding the Promise of Individuals with Autism Act, which is designed to provide demonstration grants for the treatment and services of persons with autism. A number of states have passed legislation mandating that insurance companies cover autism therapies. Celebrity involvement in raising funds for autism research and programs has helped to bring the issue to public attention. In addition to grants, fund-raising activities have included benefits, community events, and donation drives. Celebrities with children who have autism include Holly Robinson Peete, Jenny McCarthy, and Tisha Campbell Martin. The sports community is also involved through groups such as Athletes Against Autism (Triple A), which operates under the auspices of the Cure Autism Now Foundation. Triple A was founded by professional hockey players Olaf Kolzig, Byron DaFoe, and Scott Mellanby, who have autistic children. Entertainers who do not have children with autism are also involved in fund-raising and raising public awareness. Singer Toni Braxton, the national spokesperson for the advocacy group Autism Now, and comedian Bill Cosby headlined a benefit concert on April 9, 2007, that raised $1,450,000 for autism research, awareness, and advocacy. The benefit was hosted by newsman Tom Brokaw. See also: Alcohol Consumption; Birth Defects; Centers
for Disease Control and Prevention (CDC); Child Behavior Disorders; Child Development; Childhood Immunizations; Genetic Disorders; Infant and Toddler Development; Infant and Toddler Health; National Institutes of Health (NIH); Neurology; Neuroscience; Rett Syndrome. Bibliography. Arthur Allen, Vaccine: The Controver-
sial Story of Medicine’s Greatest Lifesaver (Norton, 2007); Autism Speaks, www.autismspeaks.org (cited June 2007); Boston University School of Medicine Lab of Developmental Cognitive Neuroscience, www.bu.edu/anatneuro/ dcn (cited June 2007); Judith J. Carta, ed., Issues Related to Young Children with ASD/PDD (Pro-Ed, 2006); Cure
Autism Now, www.cureautismnow.org (cited June 2007); Glynis Hannell, Identifying Children with Special Needs: Checklists and Action Plans for Teachers (Corwin, 2006); L. Juane Heflin and Donna Fiorino Alaimo, Students with Autism Spectrum Disorders (Prentice Hall, 2007); Joan L. Luby, Handbook of Preschool Mental Health Disorders and Treatment (Guilford, 2006); Paul Rhea, Language Disorders from a Developmental Perspective: Essays in Honor of Robin S. Chapman (Lawrence Erlbaum, 2007); Sally J. Rogers and Justin H.G. Williams, eds., Imitation and the Social Mind: Autism and Typical Development (Guilford, 2006); STAART, www.nimh.nih.gov/autismiacc/staart.cfm (cited June 2007); Helen Tager-Flusberg, “On the Nature of Linguistic Function in Early Infantile Autism,” Journal of Autism and Development Disorders (v.11, 1981); Fred R. Volkmar, et al., eds., Handbook of Autism and Pervasive Development Disorders (Wiley, 2005); Clarissa Willis, Teaching Young Children with Autism Spectrum Disorder (Gryphon House, 2006). Elizabeth R. Purdy, Ph.D. Independent Scholar
Autoimmune Diseases (General) Autoimmune disease (AD) is a condition where the human body’s immune system reacts against its own tissues. This process occurs in rheumatoid arthritis (RA), type 1 diabetes, systemic lupus erythematosus (SLE), Crohn’s disease, and many other debilitating ailments. Worldwide, autoimmune diseases account for much suffering and morbidity. Many estimates indicate that between 20 to 50 percent of the world’s population suffer from some variant of AD. There are too many autoimmune diseases to list here, so a few will be used for illustration. There is a worldwide distribution of autoimmune conditions and many of the causes and treatments are still unknown. No region, country, race, or gender is invulnerable to AD and the burden of disease falls on all social and economic classes. Although some relationships have been drawn between viral infections, gender, geographic locations, and even diet or occupational exposures, much remains to be seen and understood in the fight against ADs and what must be
done to treat them. AD is especially a burden in the developing world as diagnosis and proper treatment often elude those who need them most. The human body’s immune system is able to distinguish self tissues from foreign invading organisms. This is called the self-versus-nonself defense, or immune response. The immune system tissues and cells throughout the body’s systems carry markers that enable cells of the immune system to identify these self cells. Cells encountered without markers initiate an immune response and are attacked and eliminated from the human body. This is the process that occurs when an invading organism enters the body. The initiation of this response is called an antigen. Antibodies, such as B cells that will invade and collaborate to kill the attacking bacteria, fungus, or virus, are then formed to continue the response. AD occurs when the body is unable to properly distinguish self from nonself and initiates a response or an attack that eliminates its own healthy tissues. This attack can be on one organ or on a whole system of organs; for example, with SLE, antibodies are created against the patient’s own DNA. Lymph tissue found in lymph nodes throughout the body, such as the thymus, spleen, and bone marrow, are main centers for immune cells to grow and where signs or symptoms of immune system crisis can usually first be observed. Cells associated with the lymphatic and immune systems travel throughout the body in blood and lymphatic vessels. Cells that make up the immune system must communicate with one another in order to be able to distinguish which cells are invading and which are not. T cells, B cells, and phagocytes are some major constituents in the immune system. These cells suppress activation of the immune system and maintain immune system homeostasis. T cells are one type of white blood cell that attacks virus-infected cells, foreign cells, and cancer cells. T cells also produce a number of substances that regulate the immune response. Some T cells can seek and destroy invading foreign cells, while some are suppressor T cells. Suppressor T cells slow down and stop the immune response of B cells and other T cells. These suppressor cells effectively “shut off ” the antibody production when an infection is under control. When T cells fail or function improperly, AD can result and cells of the immune system attack healthy cells in the body.
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B cells are the other major class of lymphocytes, or white blood cells, involved in the immune response. B cells are white blood cells of the immune system that are derived from the bone marrow and spleen. B cells develop into plasma cells, which produce antibodies. When a B cell interacts with an antigen, it differentiates into antibody-secreting plasma cells and memory cells. It is the primary lymphocyte responsible for immunity, and is effective against pathogens such as bacteria, viruses, or fungi. B cells secrete antibodies and are involved with memory of antigens. They have a long cell life, so that in the event the same antigen invades, the immune system can identify and initiate another response more quickly than the first time it was invaded. Phagocytes are large cells that “eat” or engulf other foreign invading pathogens. When the immune system becomes compromised, or is altered and can no longer function, immune cells can become blind and begin to attack self cells. These are the basic mechanisms of the immune response and what can go wrong in the presence of AD. Epidemiology In the United States, prevalence of autoimmune disorders has been estimated as ranging from at least 10 million to as many as 50 million people. This difference reflects the current lack of consensus about which diseases meet the definition of AD. Classification of diseases as AD or not is still under review in much of the world. In the early 1980s so much of HIV/AIDS was misunderstood that some scientists classified it as an autoimmune disease. Because more of the mechanisms of HIV/AIDS became known after intense study, scientists realized it is not an AD at all. Other such misclassifications may remain in practice until more is understood about the many ADs that occur throughout the world. Standardization of this classification will bring more clarity to disease epidemiology. Furthermore, correct diagnosis is difficult even in developed nations and may happen years after medical care is first sought for an ailment. It is thought that there are many undiagnosed cases in developing nations, and this likely contributes to an inaccurate estimation of prevalence. One consensus in the medical community is that AD disproportionately affects women. Some estimates
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are that 75 percent of all cases first appear in women between 15 and 44 years of age. Because of this, the burden of disease in the developing world is significant. Women bear more responsibility for child rearing, daily-life activities, and are accountable for many other liabilities in the family unit. Furthermore, AD can occur during childbearing years, leading to further problems with their children and community. Some ADs affect African-American, American-Indian, and Latina women more often than white women in the United States. Sex-specific hormones may further amplify this hyperimmune response in women leading to the increased prevalence. Much is misunderstood and much more research needs to be done to find more causes of AD and reasons for the disproportionate number of female sufferers. ADs, thus, contribute disproportionately to morbidity and mortality among young to middle-aged women. SLE, thyroiditis, scleroderma, RA, Crohn’s disease and type 1 diabetes affect both women and men. SLE is a chronic inflammatory connective tissue disease. It is marked by skin rashes; joint pain and swelling; inflammation of the kidneys; inflammation of the fibrous tissue surrounding the heart, or pericardium; and causes the skin to lose its elasticity and can lead to total hair loss. Thyroiditis is an inflammation of the thyroid gland that causes it to become underactive and results in fatigue, weakness, weight gain, cold intolerance, and muscle aches. Sclerosis is a hardening within the nervous system, especially of the brain and spinal cord, resulting in degeneration of the nervous system and leading to eventual death. RA is a disease that attacks joints. It causes hot, painful swelling and deformity mainly to the joints of the fingers, hands, and knees. Crohn’s disease is an ongoing disorder that causes inflammation of the digestive tract. Crohn’s disease is an inflammatory bowel disease, the general name for diseases that cause swelling in the intestines. Crohn’s disease affects men and women equally and seems to run in some families, leading it to most likely be a genetically inherited AD. Type 1 diabetes, also known as insulin-dependent diabetes, is diagnosed mainly in childhood or early adolescence. This AD requires daily insulin injections for the body to metabolize sugar. The most common form is caused by the destruction of beta cells in the pancreas by an AD process. Beta cells are those found
in the pancreas and are responsible for making insulin, which controls the amount of sugar in the blood by moving it into the cells in the body for energy. When the immune system attacks these cells, the pancreas is unable to produce insulin and the body is unable to process sugar from foods to obtain energy. Treatment for type 1 diabetes in the developed world is readily available and prognosis when the treatment regimen is kept can be quite positive. Daily insulin injections, strict blood glucose monitoring, diet plan, daily exercise, and good patient and doctor follow-up are needed for good outcomes with diabetes type 1. These treatments are not readily available in the developing world. Specific incidence and prevalence rates vary among the ADs. For example, in the United States an estimated 5 percent of the population are affected by tissue-specific or systemic ADs. Most ADs can occur at any age of development and ethnic and geographic differences in incidence of specific ADs have been documented. However, specific groups may be at higher risk for some diseases and at lower risk for others, as illustrated by geographic region and women in general. For example, ������������������������������������ genetic predisposition and hormones play a part in ADs. The incidence of multiple sclerosis, Crohn’s disease, and type 1 diabetes are highest in northern Europe but nearly disappear the closer to the equator the population lives. ��������������� There are some common traits among many ADs, but there are also important demographic differences between them. Disease-specific research and studies that focus on other potentially related diseases are still underway. Genetics and Possible Causes The cause of autoimmune disorders remains largely unknown. Recent evidence supports a role of environmental agents such as chemicals, lifestyles, and family history. The important question of whether genetics plays a large role is still under review, but most research indicates that it does. For the case of thyroid disease, a recent population-based study of risks stresses the increasing importance of environmental contributions to the development of autoimmunity. For the case of RA, however, it has not yet been concluded that genetics does or does not contribute to the disease. Infection as a possible trigger for ADs has long been proposed as well. Viral infections have
received particular attention in SLE studies, with findings of virus-like inclusions in kidney biopsy tissue. These connections with infections and AD are still under review and are not conclusive. Evidence in patients that susceptibility genes exists for autoimmunity comes from family studies. These studies are especially important with twins. Studies in type 1 diabetes mellitus, RA, multiple sclerosis, and SLE have shown that approximately more than a fifth of the pairs of monozygotic (one fertilized ovum separates into two identical zygotes or fetuses) twins show disease concordance, compared with less than 5 percent of dizygotic (two separate eggs by two separate sperm; nonidentical pair twins) twins. These data suggest there may be a genetic connection with AD. Occupational and Psychosocial Risks Cigarette smoke and passive or secondhand smoke are some of the worst occupational and daily-living hazards to affect world populations in the past 100 years. Contribution to cancer and many lung disorders is becoming more understood with more research. Cigarette smoke is a known carcinogen, or cancer-causing agent, and negative health effector. Furthermore, cigarette smoke has been associated with an increased risk of developing RA and possibly thyroiditis. Also, some case-control studies from Japan, the United Kingdom, and Sweden detected a statistically significant increase in the risk of developing SLE among current smokers and identified cigarette smoking as a risk factor leading to the development of lupus nephritis. Lupus nephritis is an inflammation of the kidney caused by SLE. Another major occupational exposure possibly causing AD is exposure to crystalline silica. Crystalline silica, or silicon dioxide, is an eye, skin, and lung irritant. It is a known carcinogen and is most dangerous in the dry form. Crystalline silica is used in some highly popular brands of cleansers, glass and ceramic manufacturing, cat litter, paints, and some powdered flea-control products for pets. Crystalline silica has been identified as a strong risk factor for developing AD, especially SLE. Occupational silica exposure is most frequently associated with dusty, nonfarmingrelated jobs. In areas where chemical regulation and poor compliance persist, many workers may be heavily exposed to crystalline silica.
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Some research suggests that emotional stress from major life events may contribute to the onset of AD, and specifically RA. The cause may be different hormone levels or another unknown cause. New casecontrol studies provide several new insights into the contribution of psychosocial stress to the onset of AD and RA. For example, one study showed that in women, arguments with their partners during a five-year period preceding the RA symptoms and the five years preceding the RA diagnosis were significantly associated with the onset of RA compared with controls. The same study found men who reported problems at work preceding the onset of symptoms and economic problems within five years of diagnosis of RA. These data may not be entirely conclusive, but they offer insight into further areas of research on the causes of AD. This connection between social environmental factors and medical status is not new. Much research in the past has made the connection between the onset of ADs such as type 1 diabetes. Psychological mechanisms are directly linked by hormonal and nervous system signals, influencing the need for insulin. Stress has also been shown to modulate immune responses in a number of studies. Treatment At present, there is no known way to prevent ADs. However, with proper medication and careful monitoring, many people are able to live fairly normal lives. There are four general immunologic approaches to AD treatment: altering thresholds of immune activation, modulating antigen-specific responses, reconstituting the immune system with autologous (one’s own) or allogeneic (genetically different) stem cells, and sparing of target organs. Each treatment is different for each AD. Treatment of autoimmune diseases can focus on either suppressing the induction of autoimmunity, restoring normal regulatory mechanisms, or inhibiting the effector mechanisms. To eliminate autoreactive cells, immunosuppressive or ablative therapies are most commonly used. In recent years, cytokine blockade has been demonstrated to be effective in preventing immune activation in some diseases. New therapies are currently in clinical trials to target lymphoid cells more specifically, either by blocking a signal needed for T or B cell activation, by eliminating the effector T cells or B cells, or by
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Avery, Oswald Theodore
using autoantigen to induce tolerance. Therapies that prevent target organ damage or support target organ function remain an important therapeutic approach to autoimmune disease. These ���������������� therapies are still in early development. There is currently considerable interest in new drugs that have been associated with the development of an autoimmune response with drug-related SLE. Two recent epidemics of scleroderma-like illness, one in Spain related to a contaminant of rapeseed oil and one in the United States related to a contaminant of ltryptophan, have raised interest in potential environmental triggers of autoimmunity.� Nonsurgical treatment for the rheumatic ADs includes healthy diet, prompt treatment of infections, immunosuppressants, corticosteroids, and anti inflammatory medications. Current treatment protocols for the more severe outcomes of ADs include organ transplants and surgery to repair or replace damaged joints. It is predicted that genetic research will enable earlier and more precise diagnoses of ADs and highly individualized drug treatment. As more information is published on both risk factors for the onset of autoimmunity and for the development of progressive disease, scientists are learning more about what makes AD start and function. Many potential exposures have not been thoroughly or consistently studied for their impact on both disease onset and disease progression. More research needs to be done and treatment must reach all patients in developed and less developed countries. AD will continue to be a major problem until it is better understood and more treatments become available. SEE ALSO: Acquired Immunity; Active Immunity; Child-
hood Immunization; Diabetes Type 1 (Juvenile Diabetes); Immune System and Disorders; Immunosuppression; Lupus; Rheumatoid Arthritis; Scleroderma; Sjogren’s Syndrome.
Bibliography. American Autoimmune Related Diseases
Association, “Questions and Answers,” www.aarda.org (cited January 2007); M.A. Dooley and L. Hogan, “Epidemiology and Risk Factors for Autoimmune Disease,” Current Opinion in Rheumatology (v.18, 2003); R.P. Kimberly, “Research Advances in Systemic Lupus Erythematosus,” Journal of the American Medical Association (v.285, 2001); W. J. Koopman, “Research Advances in Rheumatoid Arthritis,” Journal of the American Medical Association (v.285, 2001);
Robert Lahita and Nicholas Chiorazzi, Textbook of the Autoimmune Diseases (Lippincott Williams & Wilkins, 2000); National Institutes of Health, “Press Release” (July 7, 1999); Noel Richard Rose and Ian R. Mackay, eds., The Autoimmune Diseases, 4th ed. (Academic Press, 2006). John Michael Quinn V University of Illinois at Chicago
Avery, Oswald Theodore (1877–1955) Oswald Theodore Avery was a Canadian-born molecular biologist and bacteriologist who discovered in 1944 that genes and chromosomes are made of DNA. Together with his colleagues Maclyn McCarty and Colin MacLeod, Avery engineered the molecular revolution in biology. Oswald Theodore Avery was born in Halifax, Nova Scotia, on October 21, 1877. He was the second of the three sons of Joseph Francis Avery, a Baptist minister, and Elizabeth Crowdy. The couple had emigrated from England to Canada. When Oswald was 10, they moved to New York where his father became the pastor at the Mariners’ Temple in the Lower East Side. Avery attended the New York Male Grammar School, the Colgate Academy, and then enrolled at Colgate University, from where he graduated with a B.A. in the humanities in 1900. In spite of his first degree, Avery chose a career in medicine, entering the College of Physicians and Surgeons at Columbia University. He obtained his degree in medicine in 1904. After a few years of practice as general surgeon, Avery transferred to laboratory work, accepting the position of associate director of the bacteriological department at the Hoagland Laboratory in Brooklyn. Under the mentorship of Benjamin White, Avery became interested in the chemical composition of pathogenic bacteria as a way to understand their biological activities. His research on tuberculosis was soon noticed by Rufus Cole, the director of the Hospital of the Rockefeller Institute for Medical Research, who asked Avery to join the Institute’s research program on pneumonia in 1913. For the next 35 years of his career, Avery focused on Diplococcus pneumonite and, as part of this research, together with McCarty and MacLeod,
Axelrod, Julius
discovered that hereditary material was composed of DNA. The three scientists observed that the “R-form” (nonvirulent) pneumococcus bacteria transformed into the virulent “S-form” after killed S-form bacteria were added to the culture. The changed bacteria were of the same type and had the same virulence of the killed bacteria. The changes from “R-form” to “S-form” were permanent and inheritable. The scientists were then able to separate the active “transforming substance” from samples of pneumococci, which turned out to be deoxyribonucleic acid, or DNA. Although Avery suffered from Graves’ disease in the early 1930s, he continued to be an active member of the Rockefeller Institute of which he became a member emeritus after his retirement in 1943. Five years later, Avery moved to Nashville, Tennessee, where he died of liver cancer on February 20, 1955. SEE ALSO: Bacteriology; DNA; DNA Repair; Genetic
Code.
Bibliography. René J. Dubos, The Professor, the Institute,
and DNA (Rockefeller University Press, 1976); MacLyn McCarty, The Transforming Principle: Discovering that Genes Are Made of DNA (W.W. Norton, 1986); Robert Olby, The Path to the Double Helix: The Discovery of DNA (Dover, 1994). Luca Prono Independent Scholar
Axelrod, Julius (1912–2004) Julius Axelrod was an American biochemist who was awarded the Nobel Prize in Physiology or Medicine together with Sir Bernard Katz and Ulf von Euler in 1970. Axelrod was presented with the Nobel for research on how neurotransmitters regulate the metabolism of the nervous system and on the mechanism for their storage, release, and inactivation. Julius Axelrod was born on May 30, 1912, on the Lower East Side of New York City. His parents were Isadore and Molly Axelrod, who were Jewish immigrants from Poland. Julius attended Seward Park High School and, in 1929, enrolled at New York University. A year later, he transferred to City College, from where
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he graduated in 1933 with a Bachelor of Science degree in biology. Axelrod found it difficult to find a job in the middle of the Depression. In 1935, he finally found employment at the New York City Department of Health’s Laboratory of Industrial Hygiene, testing vitamin supplements added to food. Three years later, Axelrod married Sally Taub, an elementary school teacher. The couple had two sons, Paul and Alfred. While working at the Department of Health, Axelrod lost his left eye in a laboratory accident. He took night classes at New York University, which awarded him a Master of Science degree in chemistry in 1941. In 1946, Axelrod joined the research division at the Goldwater Memorial Hospital under the direction of Bernard Brodie. It was while working with him that Axelrod developed the interest in pharmacology that would become the center of his career. Together with Brodie, Axelrod worked on analgesics, discovering acetaminophen (paracetamol), which became one of the most widely used painkillers in the world. Three years later, Axelrod was hired as a research chemist at the National Heart Institute (NHI) in Bethesda, Maryland. While at NHI, Axelrod obtained a Ph.D. in pharmacology from George Washington University. In 1955, Axelrod transferred to the National Institute of Mental Health (NIMH), where he directed the pharmacology section of the Laboratory of Clinic Science. Two years later, he began his work on the activity of neurotransmitter hormones that would lead to his Nobel Prize. During the 1970s, his work in the field enabled the development of a new class of antidepressants such as Prozac. Axelrod retired in 1984 and was named Scientist Emeritus of the National Institutes of Health in 1996. He died on December 29, 2004, at his home in Rockville, Maryland. SEE ALSO: National Institute of Mental Health (NIMH);
Neurology; Pharmacology.
Bibliography. Adam Bernstein, “Nobel Prize Winner Ju-
lius Axelrod,”��� Washington Post (������������������������� December 30, 2004); ����� “Contemporaries—Julius Axelrod, Ph.D.,” Modern Medicine (March, 1970); Daniel ��������������������������������������� M. Fox, Marcia Meldrum, and Ira Rezak, Nobel Laureates in Medicine or Physiology: A Biographical Dictionary (Taylor & Francis, 1990). Luca Prono Independent Scholar
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Azerbaijan
Azerbaijan Azerbaijan is located on the edge of eastern Europe, with its eastern border on the Caspian Sea. Russia and Georgia border on the north, Armenia on the west, and Iran on the south. From 1920 to 1991, Azerbaijan was part of the Soviet Union. Its population is about 8 million people. Almost 60 percent of the population live below the poverty level. Azerbaijan’s healthcare system was poor during the Soviet years, and faltered more after independence. Today, the government spends $7 per capita on healthcare. Medical personnel are only paid about $10 per month; physicians earn less than $100 a month. Equipment is outmoded and many medical procedures are outdated. Life expectancy at birth is low by regional standards. The average Azerbaijani man lives to be about 60, the average woman to about 69. The World Health Organization estimates healthy life expectancy at 59 years for women and 56 years for men. The rate of cardiovascular disease is high among men, many of whom smoke and have elevated cholesterol levels. Maternal mortality is high compared to nearby Europe, with 37 maternal deaths for every 100,000 live births. Women marry young and begin having children immediately, increasing the likelihood of highrisk pregnancies. About 40 percent of childbearing women are anemic. Access to contraceptives is limited; in one survey, 57 percent of women said their last pregnancy was unintended. For many women, abortion is the only method of fertility control, and even in the cities, contraception is limited to condoms or intrauterine devices. Azerbaijan also has some of the highest infant and child mortality rates in Europe. Infant mortality is about 69 deaths per 1,000 live births. Immunization rates are high, so most of these children die not from major infectious diseases such as diphtheria or measles, but from respiratory or diarrheal illnesses. A 2000 survey found that 20 percent of Azerbaijani children under 5 showed stunted growth, a key indicator of malnutrition. A 2001 study found that 32 percent of children under 5 were anemic. Chronic
malnutrition and anemia together lower children’s resistance to illness. Sanitation is limited outside the cities, making waterborne illnesses a problem in most of the country. Hepatitis A and B are common, as is typhoid fever. Malaria is prevalent in the central part of the country, and not uncommon in other regions outside the mountains. In spring 2006, at least five people in Azerbaijan died of the H5N1 avian flu. There are two major medical schools within the country: the Azerbaijan Medical Institute in Baku and the Institute for Advanced Training for Physicians. A network of 700 hospitals and clinics serves all but the most rural populations. Visits to state-run hospitals and clinics are free to citizens, but an increasing number of Azerbaijanis have begun to favor private clinics. Although private healthcare can be expensive, private clinics tend to have newer equipment and better-trained staff than state hospitals. A private-clinic doctor can expect to earn $500 a month, rather than $80 offered by the state. By 2005, there were 400 clinics employing more than 5,000 people. In summer 2006, the government suddenly shut down 16 of the country’s largest private clinics and more than 150 dental clinics, saying that they had violated licensing and procedural regulations. Many Azerbaijanis believe that the shutdown had less to do with standards than with a desire by the government to control the healthcare system, perhaps out of a determination to force doctors to work for the state. The matter remained unresolved in fall 2006. SEE ALSO: Armenia; Healthcare, Europe; Russia. Bibliography. Central Intelligence Agency, “Azerbai-
jan,” World Factbook, www.cia.gov (cited March 2007); Commission on the Status of Women, “Azerbaijan,” www .un.org/womenwatch (cited March 2007); United Nations Children’s Fund (UNICEF), “Azerbaijan,” www.unicef.org (cited March 2007); World Health Organization, “Azerbaijan,” www.who.int (cited January 2007). Heather K. Michon Independent Scholar
B Background Radiation Radiation is simply energy released in the form of electromagnetic waves or particles. With reference to health, radiation generally refers to high-energy forms of radiation that have the potential to cause death of the cell or mutations in the DNA. Radiation has always been present everywhere on earth; indeed, radiation accounts for part of the baseline mutation rate in nature and so contributed to the evolution of life as we know it. The natural radiation that everyone is exposed to is referred to as background radiation and is the baseline rate against which other radiation exposures are compared. There are three general outcomes when radiation energy is transferred to cells and disrupts biological molecules: (1) the cell dies, (2) the cell repairs itself properly and there is no residual damage, or (3) the cell repairs itself improperly resulting in a change. While cell death can be exploited by medicine to kill tumor cells with high-dose radiation therapy, permanent changes in DNA from low-dose radiation over years can sometimes result in cancer. Although radiation exposure in certain professions is higher due to X-rays from medical devices or radiation from nuclear reactors, the low natural baseline level of radiation all around us—background ra-
diation—constitutes the vast majority of the average person’s radiation exposure. Background radiation comes from (1) extraterrestrial sources such as cosmic rays from outer space, (2) terrestrial sources such as radon gas, and (3) within one’s body itself because of the decay of mildly unstable isotopes of potassium40 and carbon-14. Many things can contribute to the amount of background radiation an individual is exposed to at a given time: flying in an airplane where there is less atmosphere to shield against cosmic rays, being inside buildings, certain foods such as bananas that contain high levels of phosphate, or living in a particular geographic area that has more radioactive isotopes. However, people normally spend small amounts of time in airplanes or doing jobs involving minimally radioactive substances such as phosphate fertilizer, so these enhanced exposures are usually insignificant compared to the normal background radiation. To put background radiation into perspective, a commercial round-trip flight across the United States is equivalent to adding about a month of average background radiation, a total body computerized tomography (CT) scan is equivalent to four years of average background radiation exposure, mammography is equivalent to about four months of background radiation, and a simple chest X-ray
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is comparable to background radiation exposure for just 10 days. Radon and its decay products are the most important sources of background radiation. Although it had been known that those working in mines with high levels of radon were at risk for lung cancer, studies in the 1970s first demonstrated that indoor radon exposures in basements of houses could be as high as those in the mines; subsequent studies have shown that outdoor levels, although less than indoor, also represent a significant portion of the average person’s radon exposure. The link between radon exposure and lung cancer is now well established, and in the United States, radon is the second leading cause of lung cancer after cigarettes. SEE ALSO: Cancer (General); Lung Cancer; Radiation Ex-
posure.
Bibliography. Radiological Society of North America,
“Radiation Exposure in X-Ray Examinations,” www.radiologyinfo.org (cited September 2006); United Nations Scientific Committee, United Nations Scientific Committee on the Effects of Atomic Radiation 2000 Report, Sources and Effects of Ionizing Radiation, www.unscear.org (cited September 2006). Mark F. Brady, M.D. Brown University
Back Injuries Back pain is the fifth leading cause for office visits in the United States. Treatment must be based on the cause, and tailored to the patient’s health and lifestyle. Medications may decrease inflammation and ease pain. Osteopathic manipulation has been shown to be of benefit in low back pain, and physical therapy may help as well. Surgery is reserved for severe pain or where neurological function is impaired. Back injuries are the most frequent cause of back pain, and have a variety of causes. Understanding anatomy may help in understanding injury types. The front of the spine consists of round bony structures (vertebral bodies), separated by springy objects (intervertebral disks), which act
as shock absorbers for the spine during movement. The disks have a central gelatinous core (nucleus pulposus), surrounded by a tough cartilaginous ring (annulus fibrosis). The posterior spine protects the spinal cord, and also provides a site for attachment of muscles/ligaments. Congenital/developmental injuries occur during the perinatal period; for example, spondylolysis is a bony defect in part of the spine. Spondylolisthesis is anterior slippage of the vertebral body, which can cause nerve root injury. Sprains or strains from sudden stresses to the back (a fall or heavy lifting) may occur anywhere on the back, causing problems based on the severity of injury. With enough force, the vertebrae may break. Structures surrounding nerves may push on these nerves, causing numbness/tingling of the legs/toes, and if severe, loss of bowel or bladder control. Magnetic resonance imaging (MRI) is the tool of choice to detect disk herniation (protrusion of the nucleus pulposus through the annulus fibrosis) and establish the level of injury, but is reserved for patients not improving with conservative therapy, or those with “red flags,” such as loss of bowel or bladder control, muscle weakness, numbness in the groin or leg, and other worrisome signs and symptoms. Back injury may result from spread of cancer to the bone (metastasis), which weakens the bone, making it susceptible to fracture. Many types of cancer spread to the spine, and back pain in these patients is usually constant, dull, and unrelieved by rest. MRI and CTmyelography are the studies of choice for metastasis. Infection of the spine (vertebral osteomyelitis) can lead to back pain and fractures. CT and MRI are sensitive and specific for osteomyelitis, and some blood tests may help determine infection (the white blood cell count) or inflammation (the erythrocyte sedimentation rate). The most common cause of atraumatic vertebral body injury is postmenopausal osteoporosis, which often leads to compression fractures and can result in severe pain, loss of function, and diminished quality of life, especially in older patients. Studies have shown that regular exercise can slow age-related bone loss and is an effective means of preventing falls. Adequate intake of calcium and vitamin D should be encouraged in all patients at risk for osteoporosis. Vertebral body fractures can also result from flexion injuries, seen in falls or motor vehicle accidents.
Back Pain
If a fracture occurs with minimal trauma or spontaneously, a metabolic cause should be suspected, such as osteoporosis or cancer. The physical exam and radiographic appearance of the fractured vertebra help make the diagnosis. Evaluation of any back injury should involve inspection, palpation, and a neurologic exam. If a patient has severe pain or is unable to move his or her legs, a spine fracture should be assumed until proven otherwise, and care must be taken to avoid damage to the spinal cord by immobilizing the spine pending xray results. The neck should not be moved and the patient not allowed to sit up until cleared by the X-ray. CT scan or MRI should also be performed depending on the presenting complaint. The management of back injuries depends on the etiology. A sprain or strain may be managed with rest, ice, and analgesics. If due to a metastatic disease/condition, the underlying disorder should be treated along with the back injury. For example, a patient with osteomyelitis requires antibiotics as well as treatment for pain and inflammation. Back pain from acute injury may improve with antiinflammatories such as ibuprofen, analgesics such as acetaminophen, and muscle relaxants for short-term therapy. Two commonly used modalities to treat back pain due to injury are physical therapy and spinal manipulation. Osteopathic physicians may use manual therapy in combination with conventional treatment, including pharmaceuticals and surgery. Chiropractors also perform spinal manipulation, but may not prescribe medications. Some types of osteopathic manipulative therapy (OMT) are soft tissue (stretching, deep pressure, and traction); muscle energy (patient’s muscles used from a precise position in a specific direction against physician’s counterforce); high velocity, low amplitude, or thrust (high-velocity forces are used to eliminate restricted movement—this is contraindicated in some acute back injuries/osteoporosis); and counterstrain (patient is moved to a position of greater comfort, which is very useful for acute injury or tender points).While OMT is beneficial for many problems, some forms may be contraindicated in some patients, including those with back injury due to bone cancer, bone or joint infection, osteoporosis, or spinal fusion. A randomized, controlled trial concluded that patients with low back pain could be treated effectively
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with OMT when compared to a group treated with medications. Both groups improved during 12 weeks. There was no statistically significant difference between the two groups in any of the primary outcome measures, but the OMT group required significantly less analgesics, antiinflammatory agents, and muscle relaxants. Early intervention with physical therapy may lead to fewer physician visits, fewer restricted workdays, fewer days away from work, and shorter case duration. Patients may learn exercises and stretching that they can continue to do at home once the physical therapy sessions have ended. SEE ALSO: Back Pain; Diagnostic Imaging; Occupational
Injuries; Orthopedics; Osteopathy; Osteoporosis.
Bibliography. Elizabeth Cobb, Edmund H. Duthie Jr.,
and John B. Murphy, Geriatric Review Syllabus, 5th ed. (Blackwell, 2002–2004); Gunnar B.J. Andersson, et al., “A Comparison of Osteopathic Spinal Manipulation with Standard Care for Patients with Low Back Pain,” New England Journal of Medicine (v.341, 1999); Dennis L. Kasper, et al., Harrison’s Principles of Internal Medicine, 16th ed. (McGraw-Hill, 2005); Al Ropper and Robert H. Brown, Adams and Victor’s Principles of Neurology, 8th ed. (McGraw-Hill Professional, 2005); Gary C. Zigenfus, et al., “Effectiveness of Early Physical Therapy in the Treatment of Acute Low Back Musculoskeletal Disorders,” Journal of Occupational and Environmental Medicine (v.42/1, 2000). Gautam J. Desai, D.O. Deepa R. Halaharvi, M.S. III Shelley L. Alexander, D.O. University of Missouri– Kansas City School of Medicine
Back Pain Back pain is a ubiquitous complaint and one of the most common reasons for a medical office visit. The differential diagnosis for back pain is very broad. Therefore, a thorough history and careful physical exam are essential for determining the etiology of the back pain. Fortunately, most back pain complaints are benign in nature and responsive to conservative measures alone. However, in the presence
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of certain symptoms, an aggressive pathology may be suspected; this necessitates urgent evaluation and intervention. Approximately 75 to 80 percent of individuals experience back pain at some point during their lifetime. Back pain affects both sexes, all age groups, and all socioeconomic classes. Back pain most commonly affects those between 35 and 55 years old and is the leading cause of disability for individuals under 55 years old. Because of the prevalence and potentially debilitating nature of back pain, it is a major public health concern. Back injuries occur in approximately 2 percent of the U.S. workforce annually, resulting in loss of compensation exceeding $20 billion. In 1998 alone, the healthcare expenditure incurred by low back pain in the United States exceeded $90 billion. The differential diagnoses for causes of back pain are extensive. The challenge is identifying the cases where further urgent evaluation and intervention are needed. Hence, when assessing for a source of back pain, several important factors should be considered that include a person’s age, preceding events, chronicity, location, any radiating pain, additional related symptoms, and even psychological disturbances. Physical exams including thorough systematic assessment of the neurological function of the lower extremities should be performed. Imaging studies, such as conventional radiographs or more advanced radiographic studies, may be employed as well. One common source of low back pain is a herniated disc. A herniated disc or discs may be due to an acute traumatic event, repetitive use injury, postural problems, or degenerative processes. The disease involves the inner part of the disc (nucleus pulposus) bulging through the surrounding outer ring of the disc (annulus fibrosus). As a result, the extruded disc substance can compress a nerve root (pinched nerve) as it leaves the vertebral column. Common complaints of herniated discs include radiating back pain and paresthesias that follow the course of the compressed nerve’s dermatome. Physical activities or maneuvers that increase the pressure onto the disc, such as coughing, sneezing, and sitting forward can worsen the pain. First-line treatment includes antiinflammatories, activity modifications, and therapy. An individual who does not re-
Back pain is the fifth leading cause for office visits in the United States and the leading cause of disability for people under age 55.
spond to conservative treatment may be a candidate for invasive measures, such as spinal injections and disc surgery. Another etiology of back pain that should be considered in the differential diagnoses, especially among the elderly, is spinal stenosis. Spinal stenosis is the narrowing of the spinal canal or the opening for an exiting nerve. The narrowing may be congenital or may be acquired, such as from degenerative arthritis. The narrowing causes nerve compression and ischemia. Individuals with spinal stenosis complain of onset of pain, paresthesias, and weakness with walking or standing. Unlike disc herniation, the symptoms in spinal stenosis usually improve with sitting forward because the maneuver increases the diameter of the spinal canal and area of the neural foramen (canal of exiting nerve root). Initial treatment is with physical therapy and antiinflammatories as well. Surgery to widen the canal and decompress the nerve may be in-
Bacterial Infections
dicated for those who do not obtain relief from noninvasive measures. Other potential sources of back pain include spinal deformities, fractures, infection, and tumor, which may occur in the setting of fever, night sweats, significant weight loss, and bowel or bladder irregularities. These “red flag” symptoms warrant special awareness and immediate medical attention and evaluation, and a detailed history of symptoms, physical exam, and advanced imaging will aid in differentiating between these pathologies. SEE ALSO: Back Injuries; Fractures; National Institute of
Arthritis and Musculoskeletal and Skin Diseases (NIAMS); Occupational Injuries; Orthopedics; Orthopedist; Scoliosis; Spinal Stenosis. Bibliography. Ashok Biyani and Gunnar B.J. Anders-
son, “Low Back Pain: Pathophysiology and Management,” Journal of the American Academy of Orthopaedic Surgeons (v.12, 2004); Francis Shen, Dino Samartzis, and Gunnar B.J. Andersson, “Nonsurgical Management of Acute and Chronic Low Back Pain,” Journal of the American Academy of Orthopaedic Surgeons (v.14, 2006). Shen-Ying (Richard) Ma, M.D. University of Virginia Dino Samartzis, D.Sc., M.Sc., Dip. EBHC Harvard University and Erasmus University Francis H. Shen, M.D. University of Virginia
Bacterial Infections Bacterial infections occur when single-celled microorganisms called bacteria colonize the human body. While this colonization is usually fended off by the immune system, bacteria cause disease when they cannot be controlled and begin to interfere with normal function. Bacteria can invade almost any system of the body, and do so through many routes of entry. Some types of bacteria normally live symbiotically with humans, especially on the skin and in the gut, but these can cause disease when they grow out of control or enter parts of the body where they are not normally found. There are millions of differ-
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ent species of bacteria, but only a handful account for the majority of infections in humans. It is difficult to quantify exactly how much disease is caused by bacterial infections, but it is significant. In 2002, lower respiratory infections and diarrheal diseases, which are usually caused by bacteria, were the two leading causes of death in children under 5 years, accounting for 17.7 percent and 14.9 percent of all deaths before age 5, respectively. For adults, tuberculosis alone was the third leading cause of death for those ages 15–59, accounting for 1,036,000 deaths in 2002. These numbers give an indication of the devastating impact that bacterial infections have on human health. Some bacteria tend to infect certain populations, such as children, the elderly, or people with compromised immune systems. This last group has grown recently with the emergence of the HIV/AIDS epidemic, and subsequently many types of bacterial infections are reemerging as major threats to public health. The most striking example of this is tuberculosis, which was thought to be well controlled in the 1970s, but has now resurfaced, especially in areas where AIDS is prevalent. In addition to these challenges, many bacteria are quickly developing resistance to the drugs currently used to treat them. Bacterial infections are a critical challenge in current global health, especially in the context of the AIDS pandemic and emerging drug resistance. Types of Bacterial Infections Respiratory infections can be divided into two categories: upper respiratory infections (URIs) and lower respiratory infections (LRIs). Upper respiratory infections involve the nasal cavities, sinuses, pharynx, and larynx, and are most commonly caused by viruses. However, some URIs are caused by bacteria, including group A beta-hemolytic Streptococcus, which causes the syndrome known as strep throat. Other bacterial causes of URIs include Streptococcus pneumoniae and Haemophilus influenzae type B, although the latter has been largely eliminated in nations with vaccination programs. Symptoms of URIs include runny nose, cough, sore throat, fever, and sneezing. Otitis media, infection of the middle ear, is also commonly associated with URIs because the middle ear and the nasal cavity are anatomically connected by the Eustachian tube.
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Lower respiratory infections involve the lungs and bronchi, and lead to the most mortality of all infectious diseases, causing around 6.8 percent of all deaths worldwide, and one in three newborn deaths. Often used synonymously with pneumonia, LRIs are much more commonly caused by bacteria than URIs. Common bacterial pathogens include Streptococcus pneumoniae and Staphylococcus aureus, which are both gram-positive bacteria. Many strains of gramnegative bacteria also cause pneumonia; these tend to originate in the gastrointestinal tract and get into the lungs when vomit is aspirated. LRIs are characterized by high fever, shortness of breath, chest pain, and productive cough with yellow-green sputum and blood. The alveoli of the lungs become filled with fluid, compromising the exchange of oxygen for carbon dioxide. When severe, this can be fatal. LRIs can also lead to acute respiratory distress syndrome (ARDS), which is an inflammatory response in the lungs leading to rapid filling of the alveoli with fluid, respiratory failure, and death. Bacterial infections in the lungs can also lead to abscesses or collections of fluid in the space surrounding the lungs called pleural effusions. Diarrheal diseases are among the most common disease types in the world, and the causes are numerous. Bacterial infections of the intestines are a major cause of diarrhea, and impart a sizable disease burden on human populations, especially children, and especially in poor countries. Diarrheal diseases account for approximately 18 percent of deaths in children under 5 around the world, with 40 percent of these deaths occurring in Africa. Diarrhea consists of frequent, loose, watery stools, which may contain blood or fat. It is sometimes accompanied by abdominal pain or cramping, vomiting, or fever. Because so much fluid is being lost from the gastrointestinal system, diarrhea may precipitate severe dehydration, which is the primary cause of death from diarrheal illnesses. The most common bacterial causes of diarrhea are E. coli O157:H7, Salmonella enteridis, Vibrio cholerae, and Shigella. Bacterial meningitis is inflammation of the meninges due to bacterial infection. Symptoms include sensitivity to light, stiff neck, headache, fever, and confusion, although usually only one or a few symptoms are present. The symptoms in small children can be more difficult to detect, and may consist only of inactivity, poor feeding, and irritability. It is im-
portant to diagnose bacterial meningitis early and aggressively treat it because it can progress rapidly, causing death in a matter of hours, and is usually curable with antibiotics. The three most common bacteria that cause meningitis are Haemophilus influenzae type b, Neisseria meningitidis, and Streptococcus pneumoniae, although with the advent of the H. influenzae vaccine, incidence of meningitis caused by that strain has decreased precipitously. The bacteria are spread by contact with nose or throat mucus from an infected person, so close contacts are usually given antibiotics prophylactically. Endocarditis is inflammation of the inner layer of the heart, especially the heart valves. Bacteria can colonize the valves when they are damaged and blood flow around them is altered. Endocarditis can lead to spiking fever, bacteria in the bloodstream, emboli, and heart murmur. Many species of bacteria cause endocarditis, the most common of which are Staphylococcus aureus, alpha hemolytic Streptococci, and Enterococci. It is treated with high-dose antibiotics or surgical removal of the infected valve. Cellulitis is an infection of the tissue underlying the skin, characterized by inflammation and pain. It generally occurs when bacteria that normally live on the surface are introduced into the tissue below through a break in the skin. This can be done by cuts, scratches, burns, during surgery, or by placement of a catheter into a vein. Under the skin, the bacteria can proliferate, damage, and kill the host cells. There are many types of bacteria that can cause cellulitis, the most common being Staphylococcus aureus and Group A Streptococcus. These infections are usually easily treatable with antibiotics, but can persist, spread to other organs, and cause significant damage if left untreated. One well-known complication of cellulitis is necrotizing fasciitis, which infects the fascia just deep to the subcutaneous tissues. This infection spreads quickly and is fatal if not treated. Sexually transmitted infections (STIs) comprise another group of bacterial infections, the most common of which are gonorrhea, chlamydia, and syphilis. STIs are very common around the world, and often go untreated due to lack of access to healthcare and stigma surrounding sex-related issues. This poses an important challenge, because having one STI with active symptoms predisposes one to being infected with another. In the context of the HIV/AIDS pandemic,
this is a cause for concern, because being infected with an STI increases one’s risk of being infected by HIV. Symptoms of STIs include sores on the genitals, purulent discharge, and painful urination, depending on the pathogen. In women, they can also induce pelvic inflammatory disease, ectopic pregnancies, and miscarriages, and in poor regions of the world, STIs and their complications are the most common cause of illness and death for women. STIs can also cause infertility in men, and be passed on to babies born to infected mothers, potentially resulting in blindness, disability, or death. In addition, STIs are often asymptomatic, and infected individuals often do not know that they are infected unless they are tested, yet can still infect others. Urinary tract infections include infections of the urethra (urethritis), the bladder (cystitis), and the ureters and kidneys (pyelonephritis). Symptoms include frequent urination, pain in the bladder, cloudy urine, fever, and nausea. The most common infectious agents are Escherichia coli and Staphylococcus saprophyticus, which are easily treated with oral antibiotics. However, if the infection ascends to the kidneys, indicated by tenderness in the ribs next to spine, intravenous antibiotics may be necessary. Untreated pyelonephritis can result in kidney failure, especially in children. Urinary tract infections are most common in sexually active women and individuals with urinary catheters. All of the different types of infections discussed thus far can potentially lead to bacteremia, or bacteria in the bloodstream. Transient bacteremia happens frequently. For example, after brushing one’s teeth, it is normal to have minute amounts of bacteria in the bloodstream. These bacteria are usually cleared by the immune system and do not lead to disease. However, when a bacterial infection is present, much higher levels of bacteria can be released into the blood stream over a longer period of time. In these cases, the immune system may react with a systemic inflammatory response called sepsis. This response is an overreaction that causes inflammation and coagulation throughout the whole body. This can progress to multiorgan dysfunction syndrome and death. Sepsis is characterized by rapid heart rate, high fever, hyperventilation, and high or low white blood cell count. Management and treatment con-
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sists of antibiotics, drainage of fluid collections, fluid replacement, and organ support. Global Impact and Drug Resistance Clearly, bacterial infections are diverse in their presentation and severity. It is striking, however, that on the global scale such a large proportion of morbidity and mortality is accounted for by a relatively small cohort of pathogens. Bacteria are a major health concern in both rich and poor countries. While some infections like cholera are more of a concern in areas with poor sanitation, others such as methicilline-resistant Staphylococcus aureus are a growing concern in hospitals of industrialized countries. One example of a pathogen with a truly global reach is Mycobacterium tuberculosis. This bacterium causes tuberculosis (TB), which is considered a reemerging infectious disease, largely due to coinfection with HIV. About one-third of the world population is infected with tuberculosis, meaning that they have the bacteria in their lungs; however, only 10 percent of those will develop active disease. The other 90 percent remain asymptomatic, with the bacteria contained in their lungs by their immune systems. However, with the spread of HIV and the epidemic weakening of immune systems, more people are unable to keep their chronic infections at bay, and progress to develop TB. Tuberculosis illustrates another important aspect of bacterial infections: drug resistance. TB is curable with the administration of triple antibiotic therapy. Yet this therapy needs to be administered rigorously for several months in order to work. If the drug regimen is not followed well, there is a risk that drug resistance will develop. Drug resistance follows the basic principles of evolution. When there is a population of bacteria in an infection, and they are treated with an antibiotic, some of them may develop mutations that make them unsusceptible to the drug. With the fast pace at which most bacteria reproduce and the large numbers of organisms in a given infection, this is almost inevitable. If those resistant bacteria survive beyond the course of treatment, they may reproduce and become an infection of drug-resistant bacteria. This is what has been happening with TB; the improper administration of drug therapy over time has led to strains of M. tuberculosis that are resistant to the standard treatment regimens. In some parts of the
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world, there are cases of multidrug-resistant tuberculosis (MDR-TB) that are essentially untreatable. SEE ALSO: Bacteriology; Chlamydia Infections; Cholera;
E. Coli Infections; Gonorrhea; Meningitis; Pneumonia; Salmonella Infections; Staphylococcal Infections; Streptococcal Infections; Tuberculosis. Bibliography. Paul Farmer, Infections and Inequalities:
The Modern Plagues (University of California Press, 2001); Mark Gladwin and Bill Trattler, Clinical Microbiology Made Ridiculously Simple (MedMaster, 2004); Laura Janneck, “Diarrheal Diseases in Global Health,” in Chinelo Enwonwu and Eva Nieder, eds., Public Health Management & Policy: An Online Textbook, www.case.edu/med/epidbio/ mphp439 (cited December 2006); World Health Organization (WHO), World Health Report (WHO, 2003). Laura Janneck Case Western Reserve University School of Medicine
Bacteriology Bacteriology, or the study of bacteria, is a subdiscipline of microbiology. Bacteriology encompasses many fields, including medicine, technology, agriculture, business, biology and sanitation. Bacteriology’s beginnings date back to around 1000 b.c.e. and methods of food preservation used by the Chinese, who worked to prevent food from spoiling, though they did not know the exact cause. The modern foundation for bacteriology is credited to the 19th-century botanist Ferdinand Cohn, who was the first to describe a method of organizing microorganisms. His methodology of taxonomic classification is still used today, although it has been refined many times. Bacteria are divided into over 3,000 known species, but it is estimated that this represents less than 1 percent of all the species available in nature. Bacterial taxonomy is based on morphology and genetic structure, as well as environmental characteristics. Recently, bacteriology has expanded to include the recently discovered archaea. Archaea are also single-celled organisms, but they are believed to have existed before
what we classify today as bacteria, having branched from the evolutionary tree before bacteria. Bacteria are defined as single cell, prokaryotic microorganisms. The name bacteria (or singularly bacterium) was derived from the Greek word βακτηριυ, meaning “small stick.” Bacteria have three distinct recognizable regions: the cell membrane, the cytoplasmic region, and the appendages. The cell membrane region has two distinct functions. First, the general morphology of the bacteria, whether spherical, rod, or spiral/bent rod is determined by the cell membrane. Second, the molecular structure of the membrane, whether a monolayer or bilayer, affects the properties of the cell. The cytoplasmic region contains all genetic materials and all structures used to process food, conduct respiration, and make energy. The appendages are critical in the development of movement. They range from short filamentous sweepers to long tails and flagella. The plethora of morphologies including cocci- (spherical) and rod-shaped can range in size from 0.5 to 5 micrometers (10-6 meters). Bacteria can live in virtually every environment on earth, from deep-sea thermal vents to the subzero temperatures in the Antarctic. Bacteria are found in foods, in the air, in the soil, in water, and on human skin. Each environment carries its own obstacles for bacteria to overcome, and they have evolved to have characteristics that allow them to thrive in such extreme conditions. Bacteria in the soil must combat fluctuating alkalinity, relatively low amounts of oxygen, and even other bacteria. Bacteria living in air developed spores to adapt to a constantly changing environment. Those living in marine environments have responded to the low levels of light and oxygen by developing different methods for respiration and energy production. Bacteria living on food and the human body are extremely susceptible to other microorganisms and the natural defenses of the host, like the high acidity found on human skin. History and Definitions Bacteriology could not have progressed without the rapid development of the microscope, as bacteria cannot be viewed with the unaided eye. The development and constant refinement of the light microscope is directly correlated with the introduction of bacteriology as a subdiscipline of microbiology. Although the first use of the microscope appears to have been around
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Bacteriology encompasses many fields, including medicine, technology, agriculture, business, biology, and sanitation. One of the benefits of bacteriology has been the production of antibiotics, which have increased life expectancies around the world.
1625 by Francesco Stelluti, Antony van Leeuwenhoek, a Dutchman, conducted the first use of the microscope to accurately describe and observe microorganisms around 1648. Leeuwenhoek was a scientist at heart, but a draper and haberdasher by trade. In his spare time, he made simple microscopes consisting of two convex lenses between plates. By shining a light at an angle onto his glass lenses, Leeuwenhoek was able to magnify 50 to 300 times and observe microorganisms. He made over 400 varieties of microscopes, nine of which have survived today. These surviving scopes are still able to magnify on the order of 270 times. From these observations, he made constant reports to the British Royal Society. Leeuwenhoek described microorganisms as animalcules. Because he utilized new technology he was met with much skepticism over his findings. In addition to Leeuwenhoek, notable scientists include Robert Koch and Louis Pasteur. Pasteur, a French chemist, is most famous for his pasteurization techniques for food preservation, his disproving of the theory of spontaneous generation, and the development of vaccines for diseases caused by anthrax and fowl cholera. Koch, a German doctor, is notable for his development of the germ theory of disease, the
development of agar as a medium for culture growth, and for his postulates. Koch’s work included the isolation and observation of anthrax, incorporating two of the most fundamental aspects of bacteriology. He formulated scientific postulates for the establishment of an organism as the causative agent in disease, stating that (1) it must be found in all cases of the disease observed, (2) it must be prepared, isolated and maintained in a pure culture, (3) it must be capable of producing the original infection, even after several generations in culture, and (4) it must be retrievable from an inoculated host and cultured again. Techniques and new Developments Today, there are many techniques used in bacteriology. The most common tests are the gram stain and the acid-fast stain. Utilization of the aseptic technique is critical in the laboratory. The aseptic technique is utilized to prevent contamination of work spaces, media, and pure cultures. Its guidelines are useful not only in bacteriology but in any medical, biological, or sanitation work. Contamination is a constant problem when working in a laboratory because of microorganisms’ abilities to live in virtually every environment.
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When a pure culture is obtained for observation there are three basic rules that must never be broken to avoid contamination. First, all materials that will touch the culture in any way must first be sterilized. Second, any and all media used for transferring, storing, and culturing microorganisms must be sterilized. Third, no contaminants may be allowed to enter the field of work so as to keep the area sterile. The use of dyes to observe bacteria and microorganisms is also a necessity for practicing bacteriology. The categories of dyes range from acidic/basic dyes to natural dyes. Dyes are used to stain specific structures within the microorganism, to generally stain the whole organism, and as negative stains. The processes of dyeing are based on the molecular morphology of the bacteria, especially the cell membranes. The methodology for staining is rather simple. The culture is fixed and dried onto a platform, whether a slide or culture plate. The process of fixation and drying kills the bacteria, effectively reducing its pathogenicity. From this point, the chosen dye is applied according to the standards of practice, and observations are then documented. Modern bacteriology includes industrial microbiology and biotechnology. Most of the microorganisms used have been isolated or genetically modified in some way. Isolation and selection of microorganisms in this way is called bioprospecting. One major product of bacteriology has been the production of antibiotics. Antibiotics are therapeutic agents used to destroy bacteria in order to cure disease in animal and plant species. In addition to the production of antibiotics, bacteria, and to some extent viruses and fungi, are being used as biopesticides to combat disease. The future of bacteriology may involve advancements in electron microscopy, further genetic engineering correlated with bacteriophage, and the introduction of better antiviral therapies and nanotechnology that may lead to new ways to combat cancers or easily introduce substances for genetic therapy into the human system. See also: Anthrax; Antibiotics; Bacterial Infections; Bio-
logical and Chemical Weapons; Laboratory Tests; Parasitic Diseases. Bibliography. G. William Claus, Understanding Mi-
crobes (W.H. Freeman, 1988); Lansing M. Prescott, John
P. Harley, and Donald A. Klein, Microbiology, 6th ed. (McGraw-Hill Science/Engineering/Math, 2004). Matthew Jordan Smith Florida State University
Bahamas Although the Bahamas ranks 52nd among world incomes ($20,200), social indicators do not always mirror this relative prosperity. Nevertheless, the government is committed to providing universal access to healthcare, and expenditures on health are generally higher than other countries in the Caribbean region. The government spends 6.4 percent of the Gross Domestic Product (GDP) on healthcare and assigns $1,220 (international dollars) per capita to total health expenditures. The 1999–2000 national budget allotted 14.8 percent of total expenses to healthcare. However, only 1.7 percent of those expenditures are targeted for social security. The private sector supplies 52.5 percent of total health expenditures, and 40.5 percent of private healthcare costs are out-of-pocket expenses. There are 1.05 physicians, 4.47 nurses, and 0.07 dentists per 1,000 population in the Bahamas. The government has instituted a series of healthcare reforms and is working to broaden the safety net for the most vulnerable members of the population. Reforms introduced in the Strategic Plan for 2000–2004 include HIV/AIDS education and care, expansion of maternal and perinatal care, family planning, elder care, disease control and prevention, and strengthened relationships with nongovernmental organizations. Data on health indicators are not always available for the Bahamas, and this makes overall analysis of Bahamian health difficult. Based on partial data, the United Nations Development Programme (UNDP) Human Development Reports rank the Bahamas 52nd of 177 countries on general quality-of-life issues. The tropical marine climate of this Caribbean island in the North Atlantic Ocean draws tourists from around the world, but particularly from the United States (80 percent). As a result, one-half of the Bahamian workforce is engaged in the tourism sector.
The island has also become a mecca for international banking and investment. Education is compulsory up to the age of 14, and islanders are generally literate (95.6 percent), with females (96.5 percent) being slightly more literate than males (94.7 percent). Approximately 85 percent of the relevant population attend primary school. Enrollment in both primary and secondary schools has dropped in recent years. Tuition at the College of the Bahamas is fully subsidized by the government. The Bahamas has a poverty rate of just over 9 percent, and just over 10 percent of the labor force is unemployed. Seven percent of the population is undernourished. Since the 1990s, the Caribbean islands have been beset by rising HIV/AIDS rates (3 percent in the Bahamas), leading to lower-than-normal life expectancy, higher infant mortality and death rates, and slowing population growth rate. Chiefly as a result of the HIV/AIDS epidemic, life expectancy in the Bahamas is only 65.6 years, with females outliving males an average of seven years. This ranking places the Bahamas 158th in life expectancy among 226 countries of the world. By 2003, 5,600 cases of HIV/AIDS had been reported, and the Bahamas had lost approximately 200 people to the disease. Only 1 percent of births in the Bahamas occur outside the supervision of trained medical personnel, and the official maternal mortality rate is 60 deaths per 100,000 live births. The infant mortality rate is 24.68 deaths per 1,000 live births. Male infants (30.29) are especially vulnerable when compared to female infants (18.96). The Bahamas ranks 97th in infant mortality. Around 94 percent of infants are immunized against measles. The crude death rate among the general population is similarly higher for males (625 per 100,000/population) than for females (485 per 100,000/population). The major causes of death among Bahamian males are HIV/AIDS, homicides, land transport accidents, ischemic heart disease, cerebrovascular disease, communicable diseases, circulatory diseases, and cancer. Males are also heavily affected by mental health, alcohol and drug abuse, and homicide. Bahamian females are more likely to die from HIV/AIDS, breast cancer, diabetes mellitus, hypertensive disease, ischemic heart disease, circulatory diseases, communicable diseases, and other cancers. Health concerns for women also include maternal morbidity, abortion, domestic vio-
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lence, and mental health. More than three-fourths of all victims of domestic violence are female. Elderly hospitalization in the Bahamas is generally a result of acute respiratory disease and diseases of the urinary and digestive systems. At the opposite end of the age spectrum, pregnancy complications, intestinal infectious diseases, acute respiratory infections, HIV/AIDS, and child abuse are the leading causes of death of children under the age of 4. Children between the ages of 5 and 9 are more likely to be affected by acute respiratory infections, intestinal infectious diseases, parasitic diseases, injuries, HIV/AIDS, and child abuse. Other causes of death include land transport accidents and deaths from fire and nutritional deficiencies. Hospitalization of this age group is generally due to acute respiratory infections, intestinal infectious diseases, parasitic diseases, injuries, and HIV/AIDS as well as to bronchitis and asthma. In addition to the same conditions that beset younger children, adolescents are likely to be affected by injuries from accidents or violence, teenage pregnancy, the consequences of becoming sexually active at an early age, HIV/AIDS, alcohol and drug abuse, diabetes mellitius, and mental illness. See also: AIDS; Cuba; United Kingdom. Bibliography. Jacqueline Anne Braveboy-Wagner and
Dennis J. Gayle, Caribbean Public Policy: Regional, Cultural, and Socioeconomic Issues for the Twenty-First Century (Westview, 1997); Central Intelligence Agency, “Bahamas,” World Factbook, www.cia.gov (cited January 2007); Chandra Hardy, The Caribbean Development Bank (Lynne Rienner, 1995); Franklin W. Knight and Teresita Martinez-Vergne, eds., Contemporary Caribbean Cultures and Societies in a Global Context (University of North Carolina Press, 2005); Pan American Health Organization, “Bahamas,” www.pa ho.org (cited January 2007); Ramesh Ramsamran, Caribbean Survival and the Global Challenge (Lynne Rienner, 2002); United Nations, “Bahamas Millennium Goals,” unstats.un.org (cited January 2007); World Bank, “Bahamas Data Profile,” devdata.worldbank.org (cited January 2007); World Health Organization, “Bahamas,” www.who.int (cited January 2007). Elizabeth Purdy, Ph.D. Independent Scholar
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Bahrain
Bahrain Bahrain is an archipelago in the Persian Gulf, just east of the Saudi Arabian coast. At 668 square kilometers (266 square miles), it is the smallest of the Arab nations. It has a reputation as a modern, cosmopolitan nation; King Hamid bin Isa Al Khalifa announced a series of reforms upon taking the throne in 2002 that included suffrage for women and open parliamentary elections. There are a few signs of stress within the small kingdom. Oil deposits, long the source of Bahraini wealth, are beginning to dwindle. The population is 708,600 and includes 235,000 foreign workers. Annual population growth is 1.39 percent. The birth rate is 17.53 per 1,000 and the death rate is 4.21 per 1,000. Median age in the kingdom is 29.7 years. Life expectancy at birth is currently 72.18 years for males and 77.25 years for females. Bahrain is a hub for international shipping and transport, with a strong petroleum and refining sector. Ninety percent of Bahrainis live in urban areas. The gross national income is $10,840. With a favorable climate and high standard of living, there is low risk of communicable disease in Bahrain. The Ministry of Health counted 71 cases of malaria, 4 cases of measles, 171 cases of pulmonary tuberculosis (TB), and 433 “unspecified” illnesses in 2005. Little is known about the extent of HIV/AIDS in Bahrain, although the Joint United Nations Programme on HIV/AIDS (UNAIDS) reports that the country has a good surveillance system for AIDS, TB, and sexually transmitted diseases, and conducts regular reports. The adult prevalence rate of HIV/AIDS is around 0.2 percent. In the 1990s, the country began mandating premarital blood testing, which has limited cases of mother-to-child transmissions. Donated blood is also screened. The ministry of health reported 10 new cases of AIDS in 2005. Morbidity and mortality in Bahrain is driven by noncommunicable disease. The leading causes of death reported by the ministry of health were circulatory diseases; unclassified illnesses; cancers; endocrine, nutritional and metabolic disorders; external causes; respiratory diseases; infectious or parasitic disease; diseases of the genitourinary systems; digestive diseases; and conditions originating in the perinatal period. Women and children are well treated within the kingdom. Contraceptive use is over 60 percent, and
the total fertility rate is 2.57 children per woman. Ninety-seven percent of women receive prenatal care, and 98 percent have trained attendants monitor them in childbirth. The maternal mortality rate is 28 deaths per 100,000 live births. Infant mortality is nine deaths per 1,000 births, and child mortality (ages 1–5) is 11 per 1,000. Children have access to medical care and free education. Bahrain devotes 4 percent of its Gross Domestic Product to healthcare and spends $619 per capita. There is both a public and private healthcare system, with nine government hospitals and nine private hospitals and dozens of clinics, including some run by the kingdom’s largest employers for the use of their workers. All the major medical specialties are available, and 100 percent of the population has access to care. The ministry of health recorded 4.46 million outpatient visits and 38,261 for the reporting year ending in 2005. See also: Qatar; Saudi Arabia; United Arab Emirates. Bibliography. Joint United Nations Programme on HIV/
AIDS (UNAIDS), “Bahrain,” www.unaids.org (cited June 2007); Ministry of Health—Kingdom of Bahrain, “HID— Health Statistics. 2005,” www.moh.gov.bh (cited June 2007); United Nations Children’s Fund (UNICEF), “Bahrain—Statistics,” www.unicef.org (cited June 2007); World Health Organization, www.who.int (cited June 2007).
Heather K. Michon Independent Scholar
Bangladesh Bangladesh is a small country lying along the Ganges Delta, where the river meets the Bay of Bengal. Originally part of India, which surrounds it on three sides, Bangladesh became East Pakistan when the British ended their colonial control of the subcontinent in 1947. From the beginning, East Pakistan had little in common with West Pakistan, which was 1,000 miles away. A 1971 bid for independence resulted in the bloody Bangladesh Liberation War. Today, Bangladesh is one of the most densely populated countries in the world and is plagued by natural disasters, economic despair, and political instability.
Barbados
The total population is estimated at about 150 million and is crowded into a country slightly smaller than the State of Iowa. There are 985 Bangladeshis for every square kilometer, or 2,639 for every square mile, making it the 11th-most densely populated country in the world. The population is growing at about 2 percent annually; this is driven in part by a high birth rate of 29.36 births per 1,000 population. Life expectancy has risen in recent years and now stands at about 62.8 years for both males and females. Child mortality rates have been dropping since the 1990s, with 54 deaths per 1,000 for children under 1 and 73 deaths per 1,000 for children aged 1–5. Poverty is pervasive in Bangladesh, with 44 percent of the population living on less than U.S. $1 a day. Malnutrition is commonplace, with 30 percent of infants underweight and 50 percent of young children underweight or stunted. Two-thirds of Bangladeshis work in agriculture, with rice as their principal crop. Garment factories have thrived in recent years, employing 2 million people, mostly women and children. Tens of thousands of Bangladeshis leave the country each year to work as laborers in Malaysia or the Persian Gulf, sending home an estimated $4.8 billion in the form of remittances. Because of the country’s location at the delta of the powerful Ganges and Bramaputra rivers, its low-lying geography, and its dense population, natural disasters have come to play a large role in the health of Bangladeshis. The Bhola Cyclone of November 1970 killed an estimated 500,000 people and displaced countless others, and in the past 30 years, Bangladesh has endured at least 170 widespread natural disasters. Between 1987 and 2001, 464,000 people were killed by cyclones and 41,400 by flooding. A slower but ultimately no less dangerous threat comes from rising sea levels due to global warming, which could rob the country of 10 percent of its total landmass by mid-century. Communicable disease is the chief cause of morbidity in Bangladesh, although a poor surveillance system makes exact figures difficult to come by. Outbreaks of bacterial diarrhea, typhoid, malaria, dengue fever, leptospirosis, and hepatitis A and E are common. Only 74 percent of the population have access to clean drinking water, and only 48 percent have sanitary facilities. Early marriage is common in Bangladesh, with 67 percent of girls wed by the age of 19. About 5 percent are married between the ages of 10–15. Childbearing
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also begins early. The fertility rate is 3.09 children per mother, with 58 percent of women having access to contraceptives. Most women in childbirth are attended by relatives; only 12.6 percent of rural women and 24.5 percent of urban woman are attended by doctors or midwives. The maternal mortality rate is 315 deaths per 100,000 live births, or about 370,000 a year. Bangladesh is making strides in improving healthcare within the country and receives a great deal of support from the international community. In 2004 there were an estimated 38,500 physicians, 20,300 nurses, and 20,500 midwives working in the country. See also: Healthcare, Asia and Oceania. Bibliography. Central Intelligence Agency, “Bangla-
desh,” World Factbook, www.cia.gov (cited June 2007); United Nations Children’s Fund (UNICEF), “Bangladesh— Statistics,” www.unicef.org (cited June 2007); World Health Organization, www.who.int (cited June 2007). Heather K. Michon Independent Scholar
Barbados The Caribbean island of Barbados is the 60th-richest nation in the world, with a per capita income of $17,300. This relative prosperity is mirrored in the general good health among the 279,912 islanders. Barbadians consider healthcare a basic human right, and healthcare is free. Government institutions provide essential drugs at no cost, and children and the elderly receive some medications free at pharmacies participating in the Barbados Drug Formulary. The government spends 6.9 percent of the Gross Domestic Product (GDP) on healthcare and allots $1,050 (international dollars) per capita to defray health costs, providing 69.4 percent of all health expenditures. Private expenditures amount to 30.6 percent of total spending, and 77.20 percent of all private costs are out of pocket. There are 1.21 physicians, 3.70 nurses, and 0.24 dentists per 1,000 population in Barbados. Literacy on the island is high at 99.7 percent. Primary school enrollment is reported at 100 percent and secondary school enrollment at 90 percent. Barbados is
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highly dependent on the tourist industry, and most of the visitors to the island come from the United States. Consequently, the island’s economy declined in the aftermath of the terrorist attacks on New York and Washington, D.C., on September 11, 2001, when scores of Americans refused to travel. Unemployment in Barbados hovers at just under 11 percent. The unofficial poverty rate is 8 percent. Most of those who live below the poverty line are single mothers and their dependent children. One hundred percent of Barbadians have access to safe drinking water, and 99 percent have access to improved sanitation. The United Nations Development Programme (UNDP) Development Reports rank Barbados 31st of 177 countries on general quality-oflife issues. Barbadians have a life expectancy of 72.79 years, with females outliving males by about four years. The current fertility rate is 1.65 children per female. Around 55 percent of females use some method of birth control. At least 98 percent of all births are attended by skilled medical personnel, and 89 percent of women receive prenatal care. The adjusted maternal mortality rate is 95 deaths per 100,000 live births. An infant mortality rate of 11.77 deaths per 1,000 live births places Barbados 149th among 225 nations of the world on this important health indicator. Infant mortality has steadily declined in Barbados, as has under-5 mortality, which fell from 16 deaths per 1,000 live births in 1990 to 12 per 1,000 live births in 2004. Infant mortality dropped from 14 to 10 in that same period. Ten percent of all infants are underweight at birth, and 6 percent of under-5s are moderately underweight. Only 1 percent of Barbadian children are severely underweight. Five percent of under-5s suffer from wasting disease, and 7 percent experience moderate to severe growth stunting. The government subsidizes 94 percent of required vaccines. As a result, 97 percent of infants receive vaccinations against diphtheria, pertussis, and tetanus (DPT1); and 93 percent are immunized against DPT3, hepatitis B, and Haemophilus influenzae type B. Only 2 percent of island children fail to receive measles vaccinations. In the 1990s the HIV/AIDS epidemic reached the English-speaking nations of the Caribbean, including Barbados, which has a 1.5 percent adult infection rate. By 2003, 2,500 cases of HIV/AIDS had been reported, and 200 people had died from the disease or
related complications. As a result, the government has launched a massive HIV/AIDS awareness program. Barbados is also susceptible to lifestyle and environmental health conditions as well as to communicable diseases and life-threatening accidents. See also: Dominica; Grenada; Trinidad and Tobago.
Jacqueline Anne Braveboy-Wagner and Dennis J. Gayle, Caribbean Public Policy: Regional, Cultural, and Socioeconomic Issues for the Twenty-First Century (Westview, 1997); Central Intelligence Agency, “Barbados,” World Factbook, www.cia.gov (cited January 2007); Commission on the Status of Women, “Barbados,” www.un.org/womenwatch (cited January 2007); Chandra Hardy, The Caribbean Development Bank (Lynne Rienner, 1995); Franklin W. Knight and Teresita Martinez-Vergne, eds., Contemporary Caribbean Cultures and Societies in a Global Context (University of North Carolina Press, 2005); Pan American Health Organization, “Barbados,” www.paho.org (cited January 2007); Ramesh Ramsamran, Caribbean Survival and the Global Challenge (Lynne Rienner, 2002); United Nations Children’s Fund, “Barbados,” www.unicef.org (cited January 2007); World Bank, “Barbados Data Profile,” devdata.worldbank.org (cited January 2007); World Health Organization, “Barbados,” www. who.int (cited January 2007). Bibliography.
Elizabeth Purdy, Ph.D. Independent Scholar
Base Excision Repair A base excision repair is a cellular mechanism that is used to repair damaged DNA during the replication of DNA. This is particularly important to ensure that mutations are not induced during this replication. The main problem with DNA has been that single bases of it can be chemically mutated by deamination or alkylation. This, in turn, may lead to incorrect base pairing and can then result in mutations in the DNA that become perpetuated. The base excision repair involves the flipping of the mutated base out of the DNA helix, and then repairing the base alone. For this, there are two enzymes that are used: DNA glycosylases and AP endonucleases.
Base Sequence
The first of these, the DNA glycosylase, has the ability to recognize a number of different damaged bases. It is also able to remove any DNA bases that are cytotoxic or that may cause DNA polymerase to make errors. Some of these DNA glycosylases have been shown to be bifunctional, by displaying a lyase activity. The DNA glycosylase then initiates a base excision repair pathway and this helps with the identification of the damaged DNA structure, or when there is an inappropriate base. Much base excision repair takes place automatically and the human body includes a large number of DNA glycosylases naturally. These include uracil DNA glycosylases, single-strand selective monofunctional uracil-DNA glycosylase (known as SMUG1), and thymine DNA glycosylase (known as TDG). Mention should also be made of the reactive oxygen species (ROS), which is the major source of endogenous DNA damage. SEE ALSO: Base Pair; Crick, Francis; DNA; DNA Repair;
Genetic Code; Genotype; Watson, James.
Bibliography. Errol C. Friedberg, Graham C. Walker,
and Wolfram Siede, DNA Repair and Mutagenesis (ASM Press, 1995); L.H. Pearl, “Structure and Function in the Uracil-DNA Glycolase Superfamily,” Mutation Research (v.460, 2000); G. Slupphaug, et al., “A Nucleotide-Flipping Mechanism from the Structure of Human Uracil-DNA Glycosylase Bound to DNA,” Nature (v.384, 1996). Justin Corfield Geelong Grammar School, Australia
Base Pair A base pair (bp) in molecular biology usually involves two nucleotides on opposite or complementary DNA or ribonucleic acid (RNA) strands that are connected together via hydrogen bonds. In the traditional Watson-Crick base pairing model in DNA, adenine (A) forms a base pair with thymine (T), and guanine (G) forms a base pair with cytosine (C). In RNA, the thyamine is replaced by uracil (U). Non– Watson-Crick base pairing models have alternate hydrogen bonding patterns with pairs such as Hoogsteen base pairs being common.
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Base pairs are often used to measure the size of an individual gene, with the total number of base pairs becoming equal to the number of nucleotides in one of the strands. With extremely complex genomes, the detailing of base pairs can be very complicated. In fact, the human genome is estimated to have 3 billion base pairs, which contain 20,000 to 25,000 distinct genes. For dealing with these large numbers, there are kilo base pairs (kb or kbp), which consist of 1,000 base pairs, mega base pairs (Mb) which have 1 million base pairs and giga base pairs (Gb). SEE ALSO: Base Sequence; Crick, Francis; DNA; Genetic
Code; Genotype; RNA; Watson, James.
Bibliography. David N. Cooper and Michael Krawczak,
Human Gene Mutation (Bios Scientific Publication, 1993); Nancy Guzzo-Pernell, “Triple Helical DNA: The Design, Synthesis and Testing of Nucleoside Bases for Selective Binding to CG Base Paid,” Ph.D. thesis, University of Melbourne (1995). Justin Corfield Geelong Grammar School, Australia
Base Sequence The nucleic acids of living organisms (DNA and RNA) are composed of a sequence of repeating units, with each unit composed of three subunits: a sugar (deoxyribose or ribose), a phosphate group, and a nitrogencontaining structure called a base. A base sequence is the specific order in which those nitrogen-containing bases appear in a particular section of nucleic acid and, for each gene in an individual, determine the genotype of that individual. DNA encodes information on genotype using four bases: adenine, thymine, cytosine, and guanine. Although DNA is a double helix, the existence of base pairs allows full communication of the information in a DNA double helix from one strand (called the coding or sense strand). RNA encodes the information on the relevant coding strand using a similar set of bases as DNA, only substituting uracil for thymine. When reported in the literature or by a laboratory, base sequences adhere to a simple set of rules allowing
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universal interpretation of findings. Unless otherwise specified, a reported base sequence is for either the coding strand of a segment of DNA or the equivalent sequence of RNA and is read from left to right. When indicated, the length of the sequence will be given in base pairs (bp), acknowledging the fact that although only one strand is shown, the underlying DNA exists as a pair of complementary strands. The first letter of each base is commonly used to abbreviate the name of the base in reporting base sequences, as a given sequence may be many hundreds or thousands of bases pairs in length. Sequences are typically written using all upper-case or all lower-case letters, although mixed usage is sometimes used when comparing two sequences to make it easier for the reader to determine differences between sequences. SEE ALSO: Base Pair; Crick, Francis; DNA; Genetic Code;
Genotype; RNA; Watson, James.
Bibliography. Robert L. Nussbaum, et al., Thompson &
Thompson: Genetics in Medicine, 6th ed., revised reprint (Saunders, 2004).
Bimal P. Chaudhari Boston University
Beals, Rodney K. (1931– ) Rodney K. Beals is an American orthopedic surgeon who described a number of congenital malformation syndromes, including the Beals syndrome, the BealsHecht syndrome, and the Hecht-Beals syndrome. Beals is a general orthopedist who specializes in bone lengthening and shortening and in treating fractures by using the Ilizarov method. Throughout his career, he has performed adult reconstruction surgeries and total joint replacements as well as pediatric orthopedic procedures. With over 100 refereed publications, Beals is considered a leading orthopedic expert in the skeletal manifestations of dwarfing conditions. Beals enrolled at the University of Oregon Medical School in 1952 and graduated with an M.D. in 1956. After his internship at Minneapolis General Hospital, he was a resident physician in general surgery at
San Bernardino County Hospital between 1957 and 1958. He started his residency in orthopedics at the University of Oregon Medical School in 1958 and completed it in 1961. In that same year, he joined the faculty of the Oregon Health Sciences University (OHSU). He became head of the Division of Orthopedics and Rehabilitation of OHSU in 1981 and served in that capacity until 1994. His interest in genetic diseases arose by chance when Beals and Frederick Hecht, a medical geneticist, had to share an office in the 1960s at the medical school in Oregon because no more single offices were available. They shared the same small room for a number of years, and, sitting so close to each other, they began sharing their interests and collaborating in clinical research. Beals and Hecht are mostly associated with three syndromes. The Beals syndrome is a form of bone dysplasia, which is characterized by short stature, broad shoulders, horizontal alignment of the clavicles, and peculiar ear malformations. The Beals-Hecht syndrome presents itself from birth and is a heritable illness of connective tissue that resembles the Marfan syndrome and arthrogryposis. The Hecht-Beals syndrome is a relatively rare, heritable condition whose main traits include the inability to open the mouth completely and pseudocamptodactyly (short finger flexor tendons with wrist extension). Beals served as president for the Western Orthopedic Association and the Lamplighters Association. He is a member of the American Orthopedic Association, a board-certified fellow of the American Academy of Orthopedic Surgeons, and an honorary member of the Little People of America. He has received many honors, including being named an American, British, and Canadian Traveling Fellow for the Combined English Speaking Orthopedic Associations of the World. SEE also: Orthopedics. BIBLIOGRAPHY. Oregon Health and Science University,
“Rodney Beals, M.D.,” www.ohsu.edu/academic/som/orthopaedics (cited January 2007): “Rodney Kenneth Beals,” WhoNamedIt.com, www.whonamedit.com/doctor.cfm/ 1271.html (cited August 2007). Luca Prono Independent Scholar
Belarus
Beijerinck, Martinus W. (1851–1931) Martinus Willem Beijerinck was a Dutch microbiologist and botanist who founded the discipline of virology with his discovery of viruses. He was the first to conceptualize that viruses were live and reproducing entities although different from other organisms. Beijerinck also discovered new types of bacteria from soil. Because he focused his research on soil and plant bacteria, his fundamental contribution to the field of general microbiology has been neglected in favor of the more dramatic studies by his contemporaries Robert Koch and Louis Pasteur on human and animal diseases. Beijerinck was born in Amsterdam on March 16, 1951. Because his family was extremely poor, Martinus did not start attending school until he was 12, although his intelligence and hard work soon allowed him to reach the top of his class. It was during this period that he developed a deep interest in plants. With the help of his brother and uncle, Beijerinck managed to enter Delft Polytechnical School, where chemistry became his main subject of study, enabling him to work with future Nobel Prize winner J.H. Van’t Hoff. He graduated in 1872, the same year that he enrolled at the University of Leiden. After passing his candidate examination magna cum laude in 1873, he held a variety of teaching posts. He obtained his doctorate from the University of Leiden in 1877. Beijerinck’s teaching methods were disliked by most of his students, and research was always his major interest. In 1885, Beijerinck left academic life to become a microbiologist at the Netherlands Yeast and Alcohol Manufactory in Delft, where he could devote his entire time to research. In 1889, he coined the term filterable virus to describe the filterability of the infectious agent of tobacco mosaic disease. Beijerinck later studied nitrogen fixation, the conversion of nitrogen gas into ammonium which makes it available to plants. Although his self-esteem was always low, his scientific reputation continued to grow, and in 1895, the Dutch government created a special position for him at the Delft Polytechnical School. While at Delft, Beijerinck developed the principles of enrichment culture, which allowed a better understanding of the role of microorganisms in natural processes. Beijerinck re-
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ceived international recognition for his discovery. He was awarded the Leeuwenhoek Medal by the Dutch Royal Academy of Sciences in 1905 and was also a candidate for the Nobel Prize in chemistry. He died on January 1, 1931, in Gorssel in the Netherlands. SEE ALSO: Virology. Bibliography. King-Thom Chung and Deam Hunter
Ferris, “Martinus Willem Beijerinck. Pioneer of General Microbiology,” ASM News (v. 62/10, 1996); “Beijerinck, Martinus W.,” MedicineNet,com, www.medterms.com/ script/main/art.asp?articlekey=39058 (cited August 2007). Luca Prono Independent Scholar
Belarus The relationship between Belarus (formerly Belo russia) and Russia has remained strong since the breakup of the Soviet Union in 1991. Both countries are struggling economically, and healthcare systems combine elements of the old and new political and economic systems. While Belarus is technically a democracy, it is in reality a dictatorship. Healthcare is available for all Belarusians, but it is often accessed through connections and informal payments, and those who have neither sometimes go without medical attention. A 2004 study found that 10 percent of Belarusians submit informal payments whenever they seek medical care. With a per capita income of $7,100, Belarus ranks 112th in world incomes. The government reports unemployment at 1.6 percent, but evidence of widespread underemployment exists. Fourteen percent of the population is engaged in agriculture. Some 27.1 percent of the population live in poverty. Belarus has one of the most equal income distributions in the world, ranking 30.4 percent on the Gini index of inequality. One-fifth of all resources are in the hands of the richest 10 percent of the population, and the poorest 10 percent claim 5.1 percent of resources. The United Nations Development Programme Human Development Reports ranks Belarus as 67th on general quality-of-life issues.
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The social security system covers all permanent residents who are employed as well as workers on cooperatives and farms. Separate systems cover aviators, teachers, artists, athletes, civil servants, some medical personnel, and those whose health was affected by the Chernobyl accident. The system is financed through a 1-percent tax on earnings. In addition to healthcare coverage, benefits include cash payments for illness, maternity leave, worker injury, and family allowances. Four percent of the total budget is directed toward healthcare. Of total GDP (Gross Domestic Product), the government expends 6.4 percent on healthcare, allotting $570 (international dollars) per capita. The government provides 75.9 percent of all health expenditures, and 4.9 percent of that amount is earmarked for social security. The private sector furnishes 26.6 percent of total health spending, and 80.50 percent of that amount is derived from out-of-pocket expenses. There are 4.55 physicians, 11.63 nurses, 0.52 midwives, 0.44 dentists, and 0.29 pharmacists per 1,000 population in Belarus. Among the 10,293,011 people of Belarus, life expectancy is 69.08 years. There is a wide gap between male (63.47 years) and female (74.98) life expectancy. Literacy is virtually universal at 98.6 percent. Approximately 94 percent of Belarusian children attend primary school. Ninety percent of males and 92 percent of females in the relevant age group attend secondary school. Safe drinking water and improved sanitation are available to the entire population. Half of all Belarusian women use birth control; on the average, women give birth to 1.43 children each. Skilled attendants are present at all births, and all Belarusian women receive antenatal care. The adjusted maternal mortality rate is 35 deaths per 100,000 live births. Belarus has an infant mortality rate of 13 deaths per 1,000 live births. Between 1990 and 2004, infant mortality was reduced from 13 to nine deaths per 1,000 live births. At the same time, under-5 mortality fell from 17 to 11 deaths per 1,000 live births. Five percent of all infants are underweight at birth. The government subsidizes all required infant vaccinations, and 99 percent of infants have been immunized against tuberculosis, diphtheria, pertussis, tetanus (DPT1 and DPT3), polio, measles, and hepatitis B. Southern Belarusians have expressed grave concern about the continuing health threat of contamination from the Chernobyl nuclear reactor accident in neigh-
boring Ukraine in 1986, and the widespread use of pesticides has polluted the soil throughout the country. Belarus has one of the highest incidences of HIV/ AIDS among the countries of the former Soviet bloc, with an adult prevalence rate of 0.3 percent. Around 15,000 Belarusians are living with the disease, which has proved fatal to some 1,000 people. Belarus has secured a loan from the World Bank and is engaged in expanding the ability to combat HIV/AIDS, tuberculosis, malaria, and other communicable diseases. See also: Russia; Ukraine. Bibliography. Dina Balabanova, et al., “Health Service
Utilization in the Former Soviet Union: Evidence from Eight Countries (Cross-Country Comparisons),” Health Services Research (December 2004); Central Intelligence Agency, “Belarus,” World Factbook, www.cia.gov (cited December 2006); Helen Fedor, Belarus and Moldova: Country Studies (Federal Research Division, LOC, 1995); Martin A. Levin and Martin Shapiro, eds., Transatlantic Policymaking in an Age of Austerity: Diversity and Drift (Georgetown University Press, 2004); Social Security Administration, “Belarus,” www.ssa.gov (cited December 2006); United Nations Children’s Fund (UNICEF), “Belarus,” www.unicef .org (cited December 2006); World Bank, “Belarus Data Profile,” devdata.worldbank.org (cited December 2006); World Health Organization, “Belarus,” www.who.int (cited December 2006). Elizabeth R. Purdy, Ph.D. Independent Scholar
Belgium The western European nation of Belgium has one of the highest standards of living in the world, and the United Nations Development Programme Human Development Reports rank Belgium 14th among the world’s nations in general quality-of-life issues. Health care coverage is universal, but Belgians have the freedom to choose supplementary coverage if desired. All hospitals receive government subsidies. The private sector plays only a minor role in healthcare in Belgium. With a per capita income of $31,100, Belgium is the 21st richest country in the world. Income is rela-
tively evenly distributed, and Belgium ranks 25 on the Gini index of inequality. The richest 10 percent of the population claim 23 percent of the wealth, and the bottom 10 percent share 3.2 percent. However, poverty (4 percent) and unemployment (8.4 percent) do exist. Belgians have a strong safety net, and health coverage is required by law. As the population ages, healthcare becomes a heavier burden for the government, and the Silver Fund was set up in 2001 to create a future reserve so that all Belgians will continue to receive quality healthcare and be able to enjoy a reasonable standard of living. The current health system had its roots in the post–World War II period. In 1963, the health system was overhauled with Leburton’s Law, which created the National Institute for Sickness and Invalidity. Physicians were so enraged by the pay schedule set up in Leburton’s Law
To plan ahead for the needs of its aging population, the Belgian government set up a special healthcare fund in 2001.
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that they went on strike in March 1964. Negotiations led to modifications to the schedule, and the strike ended in June 1964. All Belgian workers are covered through insurance programs, and public assistance, which includes health coverage, is available for those who need it. New parents may receive a birth grant or an adoption allowance. Financing involves collecting contributions from both employers (34 percent) and employees (13 percent). Self-employed Belgians are also covered, with contributions to the program based on income. Costs for healthcare and medications are either fully or partially refunded, according to an established rating system. Belgium’s commitment to healthcare leads to 9.4 percent of the total Gross Domestic Product (GDP) being expended on health. Approximately $2,828 per capita is targeted for government healthcare programs. Some 67.2 percent of all health expenses derive from government funding, and 88.4 percent of that amount is targeted for social security. The private sector contributes 32.8 percent of spending on healthcare, and 66.60 percent of that amount comes from out-of-pocket expenses. There are 4.49 physicians, 5.83 nurses, 0.64 midwives, 0.81 dentists, and 1.14 pharmacists per 1,000 population in Belgium. Belgium’s population of 10,379,067 enjoys a life expectancy of 78.77 years, with females outliving males by an average of six years. This rating places Belgium 35th in the world in life expectancy. Literacy is virtually universal (99 percent). Primary school enrollment is 100 percent, and secondary school enrollment is in the high 90s. All Belgians have access to safe drinking water and improved sanitation. Over 70 percent of women use birth control, and the fertility rate is 1.64 children per female. All births are attended by trained personnel, and antenatal care is universally available. The maternal mortality rate is 10 deaths per 100,000 live births. Belgium has the 19th lowest infant mortality rate in the world at 4.62 deaths per 1,000 live births. The government halved the infant and under-5 mortality rates between 1990 and 2004, with rates declining from 10 to five and from eight to four respectively. Although eight percent of infants are below normal weight at birth, Belgian children tend to be healthy. Immunizations rates are predictably high. Ninety-seven percent of infants receive diphtheria, pertussis, and tetanus (DPT1) vaccinations; 96 percent receive polio vaccinations; 95
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percent receive DPT 3 and Haemophilus influenzae type B vaccinations. However, only 82 percent of infants are immunized against measles, and only 65 percent are immunized against hepatitis B. The HIV/AIDS adult prevalence rate in Belgium is 0.2 percent. Some 10,000 people are living with the disease, and less than 100 others have died from the disease or its complications. Local communities have taken on a good deal of the responsibility for HIV/AIDS awareness, and schools provide information on prevention of this and other sexually transmitted diseases in sex education classes. Imported cases of yellow fever appeared in Belgium in 2001, and Belgium was one of a number of countries that suffered a scare in 2003 when severe acute respiratory syndrome (SARS) surfaced. In winter 2004, Belgium experienced an outbreak of type A/H3N2 influenza. The leading causes of death in Belgium are heart attacks, strokes, and other circulatory system diseases, followed by cancer and transport accidents. See also: Healthcare, Europe. Bibliography. Central Intelligence Agency, “Belgium,”
World Factbook, www.cia.gov (cited December 2006); Commission on the Status of Women, “Belgium,” www .un.org/womenwatch (cited December 2006); Spencer Di Scala, Twentieth Century Europe: Politics, Society, Culture (McGraw-Hill, 2004); Federal Public Service Foreign Affairs, Foreign Trade, and Development Cooperation, “Belgium,” www.diplomatie.be/en/belgium (cited December 2006); Sandra Halperin, War and Social Change in Modern Europe: The Great Transformation Revisited (Cambridge University Press, 2004); Martin A. Levin and Martin Shapiro, eds., Transatlantic Policymaking in an Age of Austerity: Diversity and Drift (Georgetown University Press, 2004); Jeremy Rifkin, The European Dream: How Europe’s Vision of the Future Is Quietly Eclipsing the American Dream (Jeremy P. Tarcher/Penguin, 2004); United Nations Children’s Fund (UNICEF), “Belgium,” www.unicef. org (cited December 2006); World Bank, “Belgium Data Profile,” devdata.worldbank.org (cited December 2006); World Health Organization, “Belgium,” www.who.int (cited December 2006). Elizabeth R. Purdy, Ph.D. Independent Scholar
Belize Belize is located in northeastern Central America, flanked by the Caribbean to the east, Mexico to the north, and Guatemala to the south. Long known as British Honduras, Belize won independence in 1981 after more than a century of colonization, but remains a member of the Commonwealth of Nations with Queen Elizabeth II as official head of state. In many respects, Belize is more a Caribbean country than a Central American one: It is the only English-speaking country in Central America, and its population is largely mestizo and Creole. There is a long-standing border dispute with Guatemala, which often claims all or part of Belize as its territory. Belize is about the same size as Massachusetts, and has a population of about 295,000 people, making it one of the least densely populated countries in the world, even for its small size. The population is growing at 2.26 percent annually, driven mostly by a high birth rate. Life expectancies have risen steadily since the 1990s, with the average Belizean living to the age of 68. Infant and child mortality have dropped by more than half since 1990, with 15 deaths per 1,000 in children under 1 and 17 deaths per 1,000 for children under 5. The Belizean economy is not robust, relying mostly on tourism and agriculture. There is about 9 percent unemployment among the small workforce. Fully onethird of the population lives in poverty, and that rate has held steady since the mid-1990s. Malaria is the chief vectorborne disease in Belize, although infection rates have been dropping steadily over the past decade. Dengue fever cases have also dropped. The country suffered a small cholera outbreak in 1992. Investment in upgrading the country’s water and sanitation systems is rapidly bringing gastrointestinal diseases under control. Almost all children receive immunization for common childhood diseases. Morbidity and mortality in Belize is driven primarily by noncommunicable diseases, with cardiovascular disease accounting for 30 percent of deaths among adults ages 50 and over in the period from 1993–96. Cancer and diabetes are also among the leading causes of death in that age group. Among people in the 20–49 age bracket, accidents and violence were a leading cause of mortality, accounting for about 9 percent of deaths in an average year; most are motor vehicle crashes.
Bell, Charles
The first case of AIDS was reported in Belize in 1986 and it now appears in 2.5 percent of the adult population, with an estimated 3,700 cases by 2006. Almost 50 percent of the infected are women, and less than 100 are children under the age of 15. The governmental ministry of health is the chief provider of medical care in Belize, with a small private sector in the major cities. There are eight general hospitals, with at least one in each administrative district, and a system of 75 health centers that handle basic services. Mobile clinics serve the more rural areas. Medical facilities are generally well-staffed and equipped. Private health insurance is becoming more popular in Belize, but is usually priced out of the reach of the average working family. Some Belizeans choose to take advantage of the lower-priced care over the border in Mexico. See also: Guatemala; Honduras; Mexico. Bibliography. Central Intelligence Agency, “Belize,”
World Factbook, www.cia.gov (cited June 2007); United Nations Children’s Fund (UNICEF), “Belize,” www.unicef .org (cited June 2007); World Bank, “Belize Data Profile,” devdata.worldbank.org (cited June 2007); World Health Organization, “Belize,” www.who.int (cited June 2007).
Heather K. Michon Independent Scholar
Bell, Charles (1774–1842) Charles Bell was a Scottish surgeon, anatomist, and artist whose research on the anatomy of the brain made a vital contribution to the field of neurology. Bell published important volumes for the discipline and discovered Bell’s palsy, the paralysis of the facial nerve that supplies the facial muscles on one side of the face, and the Mona Lisa syndrome. This syndrome takes place after Bell’s palsy when the facial nerve regenerates and provokes a Mona Lisa–like smile. With his many publications and his work as a surgeon, Bell was one of the first physicians to combine the scientific study of neuroanatomy with clinical practice. Charles Bell was born in November 1774 in Doun in Monteath, Edinburgh, Scotland. He was one of three sons of a minister of the Church of England who
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died only five years after Charles’s birth. The task of raising the three children fell completely on Charles’s mother, who encouraged them to cultivate cultural interests. Charles Bell attended Edinburgh High School for three years and then began studying medicine at Edinburgh, following the example of his elder brother, the surgeon and teacher John Bell (1763–1820). In 1799, Charles Bell graduated from the University of Edinburgh and was admitted to the Royal College of Surgeons. Bell decided to leave Edinburgh and settled down in London in 1804, where he established a private teaching practice and then bought the Great Windmill Street School of Anatomy founded by William Hunter. In 1814, the Middlesex Hospital hired Bell as surgeon and, while working at the hospital, Bell was one of the key supporters of the founding of the Middlesex Hospital and Medical School in 1828. Bell’s most important publication was An Idea of a New Anatomy of the Brain (1811), which has been described as the “Magna Carta of neurology” for its importance in establishing neurology as a discipline and a field for research. In it, Bell described the different functions of the brain and the cerebellum and showed the double roots of the spinal nerves. For the first time, these were investigated on a living donkey. In the early 1820s, François Magendie in Bordeaux, France, building on Bell’s work, was able to demonstrate that the ventral roots of spinal nerves are motor, the dorsal roots sensory (Bell-Magendie’s law). Bell served as a surgeon at the Battle of Waterloo (1815), where he operated on the wounded and produced powerful drawings of injuries. Bell illustrated his scientific publications with many detailed anatomical and surgical images. His artistic and literary background led him to write the first treatise on facial expression for painters and illustrators, titled Essays on the Anatomy of Expression in Painting (1806). In 1824, Bell became the first professor of anatomy and surgery of the College of Surgeons in London, and four years later, at the opening of the University of London, the private Great Windmill Street school was incorporated into King’s College. Bell was appointed professor of physiology at the University of London. Although he resigned from the position soon after his appointment, Bell was honored with several important awards in his later years and was considered the foremost physician and scientist of his day in England. His fame soon became international, and physi-
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cians from other countries visited him in England or crowded his lectures abroad. In 1829, he received the first medal awarded by the Royal Society (50 guineas) and was knighted by King William IV in 1831. He left London in 1836 to accept an invitation to become professor of surgery in Edinburgh, thus returning to his beloved birthplace. As he once stated, “London was a good place to live in but not to die in.” He remained an active researcher until his death, which took place in North Hallow, Worcestershire, on April 28, 1842. SEE ALSO: Neurology. Bibliography. Andrzej Grzybowski, Matthew H. Kaufman,
“Sir Charles Bell (1774−1842): Contributions to Neuroophthalmology,” Acta Ophthalmologica Scandinavica (OnlineEarly Articles), doi:10.1111/j.1600-0420.2007.00972. x, Blackwell-Synergy.com, www.blackwell-synergy.com/ doi/abs/10.1111/j.1600-0420.2007.00972.x (cited August 2007); R.A. Kazi and P. Rhys-Evans, “Sir Charles Bell: The Artist Who Went to the Roots!” Journal of Postgraduate Medicine (v.50, 2004). Luca Prono Independent Scholar
Bell’s Palsy Bell’s palsy affects one in 5,000 people, which corresponds to approximately 40,000 people annually in the United States. It does not have a more common occurrence in any particular race or gender, nor is it more severe in any race or gender. People who tend to be more at risk for Bell’s palsy are pregnant women in the third trimester, diabetics (who are four times more likely to experience it than healthy people), older people, and immunocompromised people such as those living with HIV or AIDS. It is the most common cause of temporary facial weakness or paralysis due to the two facial nerves (right and/or left) experiencing damage or other trauma. Typically, the damage occurs to one nerve rather than to both, but symmetric damage may occur. Nevertheless, symmetric, also called bilateral, damage occurs in less than 1 percent of Bell’s palsy cases. The facial nerve (cranial nerve VII) innervates the muscles of
the face, as well as carrying taste information from the foremost two-thirds of the tongue. It stems from the middle area of the brainstem. If only one facial nerve is affected, a person’s entire corresponding one-half of the face may twitch, droop, or exhibit some other form of movement disruption. Most commonly, one side of a person’s face will droop. When the person smiles, the typical half-smile is called a “Bell smile.” The onset of Bell’s palsy is usually rapid; typically, people wake up in the morning with an episode of Bell’s palsy. Some people may recognize a tingling around the eye or lip prior to the onset of an episode. Most people, however, do not have recurring episodes. Although it is most likely not serious, people with Bell’s palsy symptoms should consult a physician. Because of its not unique symptoms, there is no concrete diagnostic tool for Bell’s palsy. Rather, a physician must rule out all other possible causes for the paralysis or weakness. Bilateral Bell’s palsy is therefore difficult to distinguish from other, much more common causes of bilateral facial paralysis or weakness. Because many phenomena can disturb the facial nerve, Bell’s palsy has a variable etiology. One cause may be inflammation of the nerve due to a viral infection. Possible infections that would affect the facial nerve include viral meningitis or herpes simplex, the cause of a cold sore. The chickenpox and shingles virus (herpes zoster) or Lyme disease may also be responsible for some cases of Bell’s palsy; therefore, while Bell’s palsy is not transferable, a viral cause might be contagious. Bell’s palsy may be an additional symptom of an underlying disorder; for example, a patient with both Crohn’s disease and Bell’s palsy may in fact have a case of Lyme disease as the cause. Treatment for Bell’s palsy, if any, might include antiviral medications, if a viral cause is suspected. Most people recover completely within weeks to months of the onset. Generally, a person will recover without any medical intervention. Should the person be unable to close the eyes or mouth, thus being at risk for further complications such as a corneal infection, an antiinflammatory medication such as a corticosteroid might be prescribed. Due to the functions of the seventh cranial nerve, people with Bell’s palsy may experience intermittent loss of their sense of taste.
Benin
Because the seventh cranial nerve, like other nerves, is a bundle of neurons, when the nerve recovers from its damage or trauma, recuperating neuronal connections may form new, previously unmade connections. A new connection is called a synkinesis. A common synkinesis occurs when the neurons innervating the mouth connect to those innervating the eye; thus, a person’s eye and mouth might have some coincident movements. Another function of the facial nerve is to stimulate the salivary and lacrimal (tear) glands. Some people recovering from Bell’s palsy may exhibit tearing upon eating. This phenomenon is called “crocodile tear syndrome.” The term palsy refers to muscle weakness or paralysis. Bell’s palsy is so named for Scottish surgeonanatomist Sir Charles Bell. Over 150 years ago, Sir Charles Bell studied the seventh facial nerve and how it innervates the face. Some famous people who have had Bell’s palsy include Roger Ebert and Andrew Lloyd Webber. SEE ALSO: Bell, Charles (1774–1842); Chickenpox; Facial
Injuries and Disorders; Herpes Simplex; Infectious Diseases (General); Neurology; Neuroscience; Paralysis; Shingles (Herpes Zoster); Viral Infections.
Bibliography. James N. Parker and Philip M. Parker,
eds., Bell’s Palsy—A Medical Dictionary, Bibliography, and Annotated Research Guide to Internet References (Icon Health Publications, 2003); Philip M. Parker, ed., The Official Patient’s Sourcebook on Bell’s Palsy (Icon Health Publications, 2003). Claudia Winograd University of Illinois at Urbana-Champaign
Benin Benin is located in western Africa and is flanked by Togo and Nigeria, with a narrow border on the Bight of Benin. A French colony from 1872 to 1960, the former state of Dahomey has struggled to find its economic footing since independence. Most of the population gets by on subsistence farming, and suffers from a high burden of infectious disease.
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The population of Benin is 8,100,000, growing at 2.67 percent annually. The birth rate is 38.1 per 1,000 population and the death rate is 11.94 per 1,000 population. Median age is 17.7 years. Life expectancy is 52.28 years for males and 54.63 years for females. About 48 percent of the population lives in urban areas. Poverty is rife: gross national income is U.S. $510, and 31 percent of the population gets by on U.S. $1 a day. With a tropical climate and poor sanitation, communicable disease is the biggest threat to the Beninese. Malaria and yellow fever are common. Benin lies within the African Meningitis Belt, and has suffered through frequent epidemics of the meningococcal form of the disease. With only 67 percent of the people able to access clean water and between 11 and 33 percent of the population using sanitary waste facilities, diarrhea, hepatitis A, and typhoid are endemic. Rates of cholera and trypanosomaisis have dropped in recent years, and now seem to be under control. HIV/AIDS has struck Benin hard over the last decade, with an adult prevalence rate of 1.8 percent. An estimated 77,000 Beninese are living with the virus, 45,000 of them women. The country has a good surveillance system and has instituted a variety of educational programs. While not all at-risk populations are being reached, there have been some notable successes. Between 1996 and 2002, the rate of infection among sex workers dropped from 59.5 percent to 38.9 percent. Benin has a high rate of child mortality, with 111 deaths per 1,000 for infants under the age of 1, and 150 deaths per 1,000 for those between the age of 1 and 5. The United Nations Children’s Fund calculates that 23 percent of Beninese children under 5 are underweight, 31 percent show signs of stunting, and 8 percent are wasting. There are an estimated 370,000 orphans under the age of 17, with the AIDS epidemic likely to increase that number in coming years. More than a quarter of children are in the labor force, and 37 percent marry before the age of 18. Only 48 percent of males and 23 percent of females are literate. The total fertility rate in Benin is 5.08 children per woman. Childbearing begins early, and is assumed to lead to a high percentage of cases of obstetric fistula, a serious health issue that has not yet been recognized by the government. Nineteen percent of women have access to contraception; only 3 percent use modern
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birth control methods. About 80 percent receive some prenatal care. Almost all women who give birth in the cities do so with a trained attendant. In the rural areas, only 23 percent have trained care. The maternal mortality rate is consequently very high at 880 deaths per 100,000 live births. Benin spends 4.9 percent of its Gross Domestic Product on health expenditures. There is both a public and a private healthcare system. Within the public system are six hospitals, 84 health centers, 342 community health centers, and 300 village units; there are also more than 600 private clinics. Total medical personnel within the country includes 311 doctors, 4,965 nurses, 824 midwives, and around 5,000 community health workers. Care is accessible within the cities, but far more sporadic in the countryside. See also: Healthcare, Africa; Nigeria; Togo. Bibliography. Central Intelligence Agency, “Benin,”
World Factbook, www.cia.gov (cited June 2007); Joint United Nations Programme on HIV/AIDS (UNAIDS), “Benin,” www.unaids.org (cited June 2007); RTI International, “SubSaharan Africa—Benin,” researchafrica.rti.org (cited June 2007); United Nations Children’s Fund (UNICEF), “Benin—Statistics,” www.unicef.org (cited June 2007); World Health Organization, www.who.int (cited June 2007). Heather K. Michon Independent Scholar
Bereavement Bereavement refers to an emotional state of loss usually experienced after the death of a loved one. The word itself is related to the old English term bereafian meaning to rob. It is often confused or used interchangeably with the terms grief or mourning. However, it is important to distinguish between these concepts for the purposes of understanding and treating bereaved persons. Put simply, bereavement is the state of being after a loss, whereas grief is the reaction to the loss, and mourning is the cognitive and emotional processing of the loss. Bereavement, grief, and mourning are all contextual and vary with personal history, support systems,
life cycle, culture, and beliefs of individuals or communities who have experienced a loss. A loss does not always refer to a death or loss of a loved one. Grief reactions and a state of bereavement can follow loss of material objects, employment, physical functioning, personal freedom, social status, or even the loss of a sense of safety or security. Anticipatory grief, or the expectation of an impending loss, whether regarding oneself or another person, can be as severe as the response to the loss itself. Like major depression or anxiety, the emotional response is often accompanied by physical symptoms as well as complex social, behavioral, and cognitive changes. Bereavement, grief, and mourning are part of a normal response to a loss, but when the symptoms are intense—including morbid preoccupation of worthlessness, suicidal ideation, psychotic symptoms, psychomotor retardation, or melancholic depression—then there may be marked functional impairment that is not normal and requires expert evaluation and treatment. Mild forms of these symptoms are to be expected for some time following a loss; however, when they are prolonged (more than two months) treatment should be sought. Physiologic symptoms of grief overlap with those of depression and may include decreased sleep, decreased appetite, nightmares, exacerbation of preexisting conditions, and even auditory or visual hallucinations. Intense or unresolved grief reactions, prolonged grief, or failure to mourn appropriately can lead to serious and permanent health effects including posttraumatic stress and major depressive disorder. It may also result in physical symptoms in any body system or somatization, such as headaches or gastrointestinal problems. Many psychiatric illnesses can trace their roots to unresolved grief that may go undetected until stressors or additional loss events bring them to the surface. Complicated grief can be fatal as there is an increased risk of death by suicide in recently and remotely bereaved persons. This is particularly true in older men, and in teens following the death of a parent or friend. Stages of Grief In the late 1960s, Elisabeth Kübler-Ross described a set of five discrete stages of grief. While most re-
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4. Depression, which is usually omnipresent, may intensify after attempts at resolving the grief using denial, anger, or bargaining have all failed. 5. Acceptance is the successful resolution of the loss event. Other more recent theorists and clinicians describe the process in more dynamic terms as shock and denial, yearning and searching, disorganization and despair, followed by reorganization.
When symptoms of bereavement are intense or last for more than two months, treatment should be sought.
searchers and psychiatrists do not believe that every person must experience all of the stages and allow that the stages may be coincident and overlapping rather than discrete, the five stages of grief remain an important road map for grief and the process of mourning in a bereaved person. The five stages are as follows: 1. Denial—in which a person negates the truth of the loss despite overwhelming evidence to the contrary. Denial is a normal psychological defense mechanism that may involve outright denial or minimization of the seriousness of the event. 2. Anger—in which a person directs his/her frustrated emotions at him-/herself, another person, or at god. Anger may be focused on the events leading to the loss or at the perceived injustices of the resulting situation. The anger may be manifested “actively” by lashing out physically or verbally at the intended target, or “passively” by quiet but intense tension, failure to cooperate, or other passive-aggressive behavior. 3. Bargaining—in which a person attempts to negotiate, usually with him-/herself, regarding the conditions or consequences of the loss in order to obtain a more favorable outcome, whether real or perceived.
Special Cases and Treatment Specific patterns of bereavement, grief, and mourning are manifest in persons who share a particular set of cognitive or emotional skills at the time of the loss. This phenomenon is especially true in children who experience the loss of a parent, with the age and stage of the child very much affecting their response and the required interventions. The death of a parent is a traumatic event which challenges developing notions of trust and dependency in children of all ages. Young children may view death as a reversible event and may not seem to react as intensely, but the lifelong effects often become evident later in life. Some children may react by regressing to a previous stage of development, while others may act out their emotions as anger and delinquency. Others still will become overachievers as a response to the loss. The relationship of parental loss and achievement has been well studied; it is worthwhile to note that more than 60 percent of British prime ministers lost a parent at a young age, as did many other notable recent world leaders. In adult children, the death of a parent heightens a person’s awareness of his/her own mortality and causes significant psychosocial distress. The death of a child, particularly a young child, is a uniquely traumatic event for parents. Stillbirths, abortions, deaths in infancy, as well as deaths at any age are usually characterized by intense feelings of guilt and may require prolonged supportive therapy. Mothers who have lost a child are at exceptionally high risk of suicide and must be evaluated and cared for appropriately. The death of a spouse is usually regarded as the most common significant loss during the life cycle. It often involves a loss of a sense of self in older age groups, and a loss of hope for the future for bereaved
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young spouses. Studies have shown increased overall mortality from a variety of causes in the year following spousal bereavement. Treatment for bereaved spouses and bereaved parents can be done individually by primary care specialists or psychiatrists, or often more effectively in professionally led groups of similarly bereaved individuals. As loss, death, grief, and mourning are as ubiquitous as life, birth, and happiness, the global health importance of recognizing the differences between normal and abnormal unresolved grief cannot be overstated. Facilitation of healthy mourning in individuals, families, and communities is an important element in the primary prevention of serious illness. SEE ALSO: Death and Dying; Depression; Kübler-Ross,
Elisabeth; Mental Health; Suicide.
BIBLIOGRAPHY. Elisabeth Kübler-Ross and David Kes-
sler, On Grief and Grieving: Finding the Meaning of Grief through the Five Stages of Loss (Scribner, 2005); Michael R. Leming and George E. Dickinson, Understanding Dying, Death, and Bereavement, 6th ed. (Wadsworth, 2006); Christopher Reed, “Elisabeth Kübler-Ross,” The Guardian (August 31, 2004). Barry Pakes, M.D., M.P.H. University of Toronto
Beriberi Beriberi was an epidemic disease that caused the deaths of tens of thousands of people whose diets consisted primarily of polished white rice in the late 19th century. The relationship of this illness to thiamine deficiency was recognized in 1937, allowing for widespread treatment and prevention. It is now a rare disease that is only seen in specific populations. Nonetheless, it must not be overlooked because it may result in permanent disability or even death. Beriberi is a disorder caused by a deficiency in dietary vitamin B1 (thiamine). Thiamine is commonly found in pork, chicken, fish, eggs, organ meats, wheat germ, beans, peas, nuts, and whole grains. It is a water-soluble and heat-labile vitamin that
functions in carbohydrate metabolism. The current recommended dietary allowance (RDA) is one-half milligram per 1,000 kilocalories consumed. For most people, about one serving of a thiamine-rich food daily can fulfill this dietary need. Early symptoms of thiamine deficiency include fatigue, irritability, depression, poor concentration, and nausea. Over time, individuals can develop so-called dry beriberi or wet beriberi. Dry beriberi manifests primarily as a disease of the nervous system. It is caused by the degeneration of nerve fibers and their surrounding myelin sheaths. Individuals may experience pain, tingling, or numbness in the hands and feet, called peripheral neuropathy. As nerve damage continues, symptoms worsen to include decreased deep tendon reflexes, wasting away of the leg muscles, and eventual paralysis of the lower extremities. Wet beriberi, on the other hand, is a disease of the cardiovascular system. It is so named because individuals with wet beriberi develop an accumulation of fluid in their tissues. The malnourished heart becomes weak and dilates, leading to poor cardiac pumping and eventually to heart failure. Heart failure leads to fluid accumulation in the tissues and associated swelling, lung congestion, and shortness of breath with minimal exertion. The majority of individuals who die from beriberi do so from heart failure. Although this was once a widespread problem, beriberi is now seen primarily in select groups of people. Individuals at greatest risk include breastfed infants of mothers with inadequate thiamine intake, individuals undergoing dialysis or taking high doses of diuretics, people who have undergone bariatric surgery or have been infected with human immunodeficiency virus (HIV), and those in developing countries whose diets are mainly limited to milled rice. Alcoholics are also at risk for developing beriberi because alcohol metabolism requires higher amounts of thiamine and because heavy alcohol intake can lead to poor nutrition and impaired absorption and storage of dietary thiamine. Individuals with beriberi can easily receive thiamine by injection or in pill form. Most symptoms rapidly improve once the vitamin is given. Nervous system damage is reversible if thiamine deficiency is recognized and treated early, while cardiac damage tends to be completely reversible regardless of how long the person has been symptomatic.
Bhutan
SEE ALSO: Alcohol Consumption; Alcoholism; Nutrition;
Peripheral Nerve Disorders; Vitamin and Mineral Supplements. Bibliography. Kenneth Carpenter, Beriberi, White Rice
and Vitamin B: A Disease, a Cause, and a Cure (University of California Press, 2000); Derrick Lonsdale, “A Review of the Biochemistry, Metabolism and Clinical Benefits of Thiamine and Its Derivatives,” Evidence-Based Complementary and Alternative Medicine (v.3/1, 2006). Celina Martinez, M.D. Johns Hopkins University
Beta Error In inferential statistics, we state a null and alternative hypothesis, gather data, and compute statistics to decide whether to accept or reject the null hypothesis. Because we compute statistics on a sample in order to make decisions about a population whose parameters are unknown, there is always some probability that our decision will be incorrect. There are two ways we may be incorrect: We may reject the null hypothesis when it is true, or we may accept the null hypothesis when it is false. The first type of error is known as alpha error, or Type I error. The second type of error is known as beta error, or Type II error. For instance, we might be comparing two groups of children to see if they differ in height: Our null hypothesis is no difference between the group means on height, while our alternative hypothesis is that there is a difference in the group means. If our sample statistics indicated that there was no significant difference between the groups, while in the population they were significantly different, we would fail to reject the null hypothesis and commit a beta error. The probability of an beta error, also referred to as β (the Greek letter beta), is commonly set at 0.20, which is higher than that commonly used for alpha error (0.05) because the consequences of beta error are usually considered less serious than the consequences of alpha error. Statistical power is defined as 1- β; for instance, if β is 0.20, power is 1- 0.20 or 0.80.
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See also: Alpha Error; Meta-Analysis. BIBLIOGRAPHY. Phillip I. Good and James W. Hardin,
Common Errors in Statistics (and How to Avoid Them), 2nd ed. (Wiley, 2006); Bernard Rosner, Fundamentals of Biostatistics, 5th ed. (Duxbury, 2000). Sarah Boslaugh BJC HealthCare
Bhutan Bhutan is a landlocked country in southern Asia between China and India. Its name is derived from the Sanskrit word for “high land.” Most of the country lies within the Himalaya mountains, with many peaks over 23,000 feet (7,000 meters). Population estimates range from 650,000 to over 800,000 depending on the source. The country is sparsely settled, with most people living as subsistence farmers in small villages scattered throughout the countryside. This isolated kingdom is one of the most protected countries in the world, with tourism and foreign involvement strictly monitored to assure that the people can stay true to their Buddhist roots. Before 1999, even television was forbidden. Bhutan is the only country to measure what it calls its “gross national happiness,” defining the national quality of life by what is best for the spiritual and cultural good of its citizens. Beginning in 1961, the kingdom committed itself to building its infrastructure, and has since implemented a well-integrated system of roads, telecommunications, schools, and hospitals. Recent years have also seen tremendous progress in the area of public health. Since the 1990s, life expectancy has risen from around 49 years to 66 years. Infant mortality was nearly cut in half, from 107 deaths per 1,000 live births down to 65 deaths per 1,000. Despite this rapid rate of progress, significant challenges remain. By 2004, 62 percent of Bhutanese had access to clean drinking water and 70 percent had adequate sanitation facilities—a vast improvement over earlier times, but not enough to end waterborne diseases. The United Nations Children’s Fund estimates that six out of every 10 rural children suffer from worms, diarrhea, or skin or eye infections arising from
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poor sanitation. Acute respiratory infections and malaria are ongoing problems. Malnutrition is also an issue, especially for the rural poor, although the introduction of iodized salt has reduced the prevalence of goiter from 64.5 percent in the 1980s to 14 percent by 1996 and cretinism (a form of physical and mental stunting) has declined from 10 percent to just 0.4 percent in the same period. Children now routinely receive vitamin A supplements, and pregnant women have better access to iron supplements to control anemia. Four out of five women still give birth at home, contributing to a high maternal mortality rate of 420 deaths per 100,000 live births. The fertility rate is also high at 4.1 children per mother. About a third of all women have access to contraception; about half receive prenatal care. Delivery of medical services to the country’s many remote communities is a challenge for the kingdom. About 90 percent of the rural population lives outside the small network of roads, making it difficult to reach health centers for either preventative or emergency care. Progress is being made in this sector as well, with hundreds of new health outposts built in recent years. See also: Healthcare, Asia and Oceania. Bibliography. Central Intelligence Agency, “Bhutan,”
World Factbook, www.cia.gov (cited June 2007); United Nations Children’s Fund (UNICEF), “Bhutan—Statistics,” www.unicef.org (cited June 2007); World Health Organization, www.who.int (cited June 2007). Heather K. Michon Independent Scholar
Bile Duct Cancer Bile duct cancer, or cholangiocarcinoma, is a troublesome form of cancer because the bile duct plays a central role in the transport and storage of bile and in helping the body to digest certain nutrients and clear waste products. The gall bladder is an organ located underneath the liver that stores and secretes a substance called bile, which is originally produced in the liver. Bile reaches the gall bladder from the liver
through the bile duct and is also secreted from the gall bladder through the bile duct. Secretion of bile serves two major functions for the body: It helps to clear waste products from the body and also helps the body to digest fatty foods. The biggest risk factor for developing bile duct cancer is long-standing inflammation of the bile duct, which can be due to a number of different causes. Sclerosing cholangitis is a genetically inherited condition where inflammation of the bile duct leads to extensive scarring, which then causes narrowing of the duct. Sclerosing cholangitis can occur in the setting of ulcerative colitis, a form of inflammatory bowel disease. Another risk factor for bile duct cancer is inflammation due to formation of stones in the bile duct. Risk factors for bile duct and gall bladder stones include a high-fat diet, obesity, ethnic predisposition, age, and hormone status in women. Other conditions that can predispose a patient to bile duct cancer include polycystic liver disease, choledochal cysts or cysts of the bile duct, congenital dilation of the intrahepatic bile ducts (also known as Caroli syndrome), and cirrhosis. Cirrhosis is long-term inflammation of the liver that can be caused by a variety of conditions, including excessive alcohol consumption and exposure to certain toxins. Infection with the parasite Clonorchis sinensis, a type of fluke found mostly in Asia, can also cause bile duct cancer, as can certain toxins, such as thorium dioxide and nitrosamines. Finally, chronic infection with the hepatitis B and C viruses can significantly increase an individual’s risk of developing both liver and bile duct cancer. Cancer of the bile duct can generally be classified into two forms: Intrahepatic bile duct cancer arises in the portion of the duct embedded within the liver, while extrahepatic bile duct cancer arises in the portion of the bile duct that connects the liver to the gall bladder. Although extrahepatic bile duct cancer, or cholangiocarcinoma, carries a very poor prognosis, it is fortunately a relatively rare disease. Most patients with extrahepatic bile duct or pancreatic cancer present with the triad of symptoms of jaundice, abdominal pain, and weight loss. Fever and pruritis are other common symptoms as well. Jaundice is a yellowish discoloration of the skin and mucous membranes that is caused by a buildup of bile precursors in the body due to the blockage of their release from the body through the bile duct. Pruritis, or itchy skin, is simi-
Biochemistry
larly caused by the buildup of bile precursors in the body and the subsequent deposition of bile salts in the skin, which causes generalized itchiness. While tissue diagnosis is the norm in most cancers, it is very difficult to obtain a preoperative tissue sample in patients with bile duct cancer. Diagnosis is usually made by radiological imaging tests to identify a mass in conjunction with blood tests. Imaging studies are essential in making the diagnosis and in formulating a treatment regimen for the patient. Most patients with jaundice undergo a transabdominal ultrasound (US) as part of their initial evaluation to confirm biliary ductal dilatation, localize the site of the obstruction, and exclude gallstones. The bile duct is often dilated or enlarged due to obstruction from the cancerous mass. If the findings on US are inconclusive, some patients may go on to have a dynamic CT scan, magnetic resonance cholangiopancreatography (MRCP), and/or endoscopic retrograde cholangiopancreatography ERCP with brushing/biopsy. MRCP and ERCP are two techniques whereby a gastroenterologist inserts a scope down the patient’s esophagus, through the stomach and intestine, and into the bile duct to directly view the lesion and surrounding structures without having the patient undergo surgery. In this way, the physician can view the lesion and the degree of narrowing of the duct, can directly biopsy the tumor, and may also be able to insert stents as a temporizing measure to help relieve the patient’s symptoms related to the stenosis. There are also a number of blood tests that may be helpful in the diagnosis of bile duct cancer. The blood tests check levels of several proteins, or serum markers, that bile duct cancers can secrete. However, because these proteins can come from other sources and because they are not elevated in all patients with bile duct cancer, these tests are lacking in specificity and sensitivity. The serum markers most frequently tested in bile duct cancer are carcinoembryonic antigen (CEA) and CA 19-9. Treatment for bile duct cancer usually involves surgery to remove the tumor. For this reason, when a diagnosis is made by tissue biopsy or based on radiological, clinical, and laboratory findings, determining the potential respectability of the tumor is of paramount importance. If the tumor involves important blood vessels, such as the portal vein or the hepatic artery, presurgical hepatic arteriography or portal venogra-
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phy may be helpful in determining the degree of vascular involvement. Although surgery is the only way of attaining a cure in bile duct cancer, only about 10 percent of cases are curable by surgery alone. For the remainder of patients, surgery may be performed as a palliative, or symptom-reducing, measure to alleviate the pain associated with the bile duct obstruction and reduce the symptoms of jaundice and pruritis. Additional treatment options include radiation therapy and stenting procedures to relieve obstruction and improve biliary drainage. Factors that worsen a patient’s prognosis include size and number of the tumors and their invasion into nearby nerves and other structures, which can complicate surgical resection. SEE ALSO: Cirrhosis; Gallbladder and Bile Duct Diseases;
Liver Cancer; Liver Diseases (General).
Bibliography. Piet C. de Groen, Gregory J. Gores, and
Nicholas F. LaRusso, “Biliary Tract Cancers,” New England Journal of Medicine (v.341/18, 1999); Donald E. Henson, Jorge Albores-Saavedra, and Donald Corle, “Carcinoma of the Extrahepatic Bile Ducts. Histologic Types, Stage of Disease, Grade, and Survival Rates,” Cancer (v.70/6, 1992). Jennifer Hellawell Cornell University
Biochemistry Biochemistry is the science that studies the chemistry of processes that take place in living creatures and make life possible. The term biochemistry only became widely used in the early part of the 20th century; the subject had previously been known as biological chemistry or physiological chemistry. Important areas of biochemistry include the study of digestion and of the differences between intake and outflow of energy in different forms in living creatures and the identification of the component parts of and chemical reactions within blood. Biochemistry also improves our understanding of the role and composition of hormones and genes and helps explain the nature of evolution in chemical terms. All of life depends on a series of critical chemical reactions. The process of photosynthesis, for example,
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by which plants convert sunlight into energy, is a fundamentally chemical process. Animal life depends on the ingestion of food (generally a physical action) and then the conversion of that food into energy through digestion, which is a series of chemical reactions that break down the food into a variety of chemicals that may power the animal or else be eliminated as waste. All of the many chemical reactions involved in this process may be considered metabolism. Metabolism, in turn, depends on the presence of enzymes, which are chemicals present in large numbers in all complex living creatures and which are created and regulated by genetic information contained within DNA and within cells. It is difficult to isolate biochemistry from the many other fields of science with which it is linked. This complexity suggests the need for cooperation between scientists from different fields and the importance of creating cross-discipline teams. The possibility of contemplating a body of knowledge and investigation to be known as biochemistry was not possible before chemistry itself was properly established as a body of knowledge. It was only when scientists such as Robert Boyle and AntoineLaurent Lavoisier pioneered the field of chemistry that its impact on the biological sciences began to be recognized. Subsequently, scientists such as Louis Pasteur were able to identify the interaction between chemistry and biology on a firmly experimental basis. What was identified by experiment has been brought into the realm of theory. Improvements in equipment and documentation, as well as in the distribution of information and findings by computer networks, have enabled complex and sophisticated examinations that were not possible until recent decades. Genome sequencing, for example, requires experimental data gathering and analysis of such intensity that it would have been almost unimaginable until very recently. Advances in biochemistry have helped explain how creatures living in different environments survive, while providing insights into the ways in which life might flourish in alien contexts. This understanding is constantly changing with new discoveries about the extreme conditions in which life exists on earth—including in much higher temperatures and much deeper under the surface of the sea than had previously been believed.
SEE ALSO: Genetics; Hormones; Metabolic Disorders. BIBLIOGRAPHY. Robert K. Murray, et al., Harper’s Il-
lustrated Biochemistry, 27th ed. (McGraw-Hill Medical, 2006); Colleen Smith, Allan Marks, and Michael Lieberman, Marks’ Basic Medical Biochemistry: A Clinical Approach, 2nd ed. (Lippincott Williams & Wilkins, 2004); Donald Voet, Judith G. Voet, and Charlotte W. Pratt, Fundamentals of Biochemistry: Life at the Molecular Level (Wiley, 2005). John Walsh Shinawatra University
Biodefense With the increasing concern about possible biological warfare attacks in recent years, many governments have been involved in developing “biodefense” techniques to protect military combatants and civilians from biological attacks. Biological warfare has been practiced since ancient times, when people sometimes poisoned the water supplies of their rivals. There were also cases when the bodies of people who had died of the plague were catapulted into besieged cities, and on some occasions, attempts were made to infect letters by bringing them into contact with the body of a plague victim in the hope that the disease might then be transmitted to the political leaders they were sent to. Although both of these techniques provoked fear, neither could be successful unless the diseased fleas that carried the plague were also transmitted. Later, biological warfare involved attacks on water supplies and food supplies of particular countries or city states, and there have been attempts to spread disease to the domesticated animals of enemy countries. The term biodefense includes attempts by a government or organization to prevent such attacks, but it may also include prevention of the spread of disease of plants and domesticated animals through use of quarantine laws. Some countries, especially island nations, have introduced strict laws, with the British Isles having tough quarantine restrictions on the importing of animals, including pets such as dogs that may suffer from rabies. Australia and
Biofeedback
New Zealand continue to maintain strict quarantine regulations banning the import of all animals, plants, and plant materials except under very stringent conditions. However, the media’s focus on biodefense is largely concerned with the possibility of a biohazard terrorist attack, often known by the term bioterrorism. Whereas soldiers on the battlefield often have methods of protection against both chemical and biological warfare, the civilian population is generally regarded as unprotected. Although some news organizations have engendered fear in the public about possible widespread biological terrorism, the use of biological weapons has always been extremely hazardous. A small attack with anthrax occurred in the United States in the early 2000s, but there has also been the fear of the spreading of diseases such as smallpox, the plague, and others. The result has been that some governments have stockpiled vaccines to deal with these diseases. In Australia in recent years, these vaccines have been useful in dealing with small outbreaks of anthrax that occurred along some old stock routes, and also equine encephalitis, although the number of people affected has been small, and none of these incidents were bioterrorism. Mention should also be made of diseases that have been deliberately spread by governments, such as myxomatosis, which existed naturally in some parts of South America, being first observed in Uruguay in the early 1900s, and was introduced in western Europe and Australia in 1950 to control the rabbit population. It was very effective, but gradually some rabbits managed to build up natural defenses and it is now ineffective. In 1996 the calicivirus, also known as the rabbit hemorrhagic disease, was also developed by the Commonwealth Scientific and Industrial Research Organization in Australia for the same purposes. In the United States, the National Biodefense Analysis and Countermeasures Center (NBACC) was established in 2001 following the anthrax attacks; it is based at Fort Detrick in Frederick, Maryland. The United States Medical Research Institute of Infectious Diseases (USAMRIID), a military research institute, is also based at Fort Detrick. SEE ALSO: Bioterrorism; Biological and Chemical Weap-
ons.
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BIBLIOGRAPHY. Anthony H. Cordesman, The Challenge
of Biological Terrorism (CSIS Press, 2005); Neelina H. Malsch, ed., Biomedical Nanotechnology (Taylor & Francis, 2005). Justin Corfield Geelong Grammar School, Australia
Biofeedback Biofeedback is a form of complementary and alternative medicine that involves measuring the responses of a patient, such as the blood pressure, heart rate, or skin temperature, to provide patients with feedback about their awareness and their conscious control of physiological activities. This has gradually been expanded to deal with perspiration and muscle tension. Dr. Neal Miller, a neuroscientist from Yale University, developed the concept of biofeedback in the 1960s after he was involved in animal experi-
The electromyogram (EMG) has been useful with aches and pains and conditions that worsen under stress, such as asthma and ulcers.
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mentation about the behavioral responses of rats. His team of researchers discovered that when the pleasure center of the rat’s brain is stimulated by electricity, this results in changes in the heart rate, proving that rats were under the control of an automatic nervous system and were not just responding to conscious efforts. These experiments were then applied to humans to find out whether humans also respond automatically. Dr. Elmer Green of the Menninger Foundation continued the research, developing it in other areas and conducting a large amount of original research on the responses of functions in humans to particular activities. This helped develop some ways of dealing with headaches and migraines. By the early 1970s, much work was being conducted by Dr. Barbara B. Brown who coined the term biofeedback and later established the Biofeedback Research Society, which evolved into the Biofeedback Society of America and is now the Association for Applied Psychophysiology and Biofeedback. Her book Stress and the Art of Biofeedback helped to spread these ideas to healthcare professionals around the world. Mention should be made of some religious and spiritual groups that have long claimed that systems such as yoga have essentially fulfilled this purpose for hundreds of years. Because of increased interest in biofeedback, a number of systems of measuring biofeedback data have developed. The original method of measurement was having sensors attached to fingers and feet to measure skin temperature. As body temperature usually drops when a person experiences stress, this method can be used to measure headaches, especially the frequency of migraines, and also circulatory problems, such as Raynaud’s disease. However, the most common method of obtaining biofeedback now is with the use of the electromyogram (EMG), which uses electrodes and other types of sensors to measure muscle tension or lack thereof in a patient. This has been useful for measuring problems such as backaches, headaches, and neck pain. It can also be used for the measurement of medical conditions that can worsen under stress, such as asthma and ulcers. Other methods of obtaining biofeedback data have relied on the Galvanic skin response, whereby sensors measure the activity of sweat glands or the amount of
perspiration. This is the system often used by lie detectors, which aim to try to measure minute changes in these body functions in response to stress. Medically, it is also used to measure phobias, anxiety attacks, and stuttering. The last major method of collecting data is using electroencephaolography (EEG), where a machine measures brain waves linked to relaxation, calmness, deep sleep, light sleep, and other related areas. Because of the cost of these machines, this system is rarely used. A new area of biofeedback is the technology developed by Massimiliano Peretti to test people’s automatic responses to artwork and music. Although the original research seemed ephemeral, some similar studies have been undertaken to help shopping malls, trade fairs, business conference venues, and supermarkets determine the best designs, music, temperature, and the like. SEE ALSO: Alternative Medicine. BIBLIOGRAPHY. Boris Blumstein, et al., eds., Brain and
Body in Sport and Exercise: Biofeedback Applications in Performance Enhancement (Wiley, 2002); Barbara Banter Brown, Stress and the Art of Biofeedback (Harper & Row, 1977); Jim Robbins, A Symphony in the Brain: The Evolution of the New Brain Wave Biofeedback (Atlantic Monthly Press, 2000); Mark S. Schwartz, Biofeedback: A Practitioner’s Guide (Guilford, 2003). Justin Corfield Geelong Grammar School, Australia
Bioinformatics Bioinformatics involves the use of a range of techniques in computational biology to solve biological problems on a molecular level. It uses methods of applied mathematics, chemistry, biochemistry, informatics, statistics, computer science, and artificial intelligence. Bioinformatics has led to major advances in a range of fields, such as the modeling of evolution and the measuring of biodiversity, and medical advances including gene finding, genome assembly, the prediction of gene expression, analysis of protein–protein interactions, modeling
Biological and Chemical Weapons
of protein structure alignment and prediction, and sequence alignment. The use of bioinformatics in the prediction of protein structure has been important and has led to protein threading. Homology and homology modeling are used to determine which parts of proteins are the important sections of their structures and how they interact with other proteins. With its successful use in work on protein structure, bioinformatics has been used to assist with recent advances in the finding of genes and the genome assembly, which in turn have been particularly useful in a number of separate fields. With the core of comparative genome analysis of humans being orthography analysis, involving the establishment of the correspondence between genes, as well as integrating information from genomic features in different organizations, has led medical researchers to investigate new areas such as the analysis of mutations in cancer. One of the main problems with cancer research has been that for any analysis of individual cancers, there has to be a massive sequencing effort to identify point mutations in a variety of cancer genes. This has meant that vast amounts of data have needed to be stored, and automated systems developed to process sequence data. Similarities and differences in cancers have been found, however, and this work has allowed researchers to develop a further understanding of the problems that reoccur in similar forms of cancer. Bioinformatics is increasingly important because more data is being collected by researchers, and faster computers running better software, such as Perl as well as the previous algorithms using BLAST, can analyze information much more quickly than before. Medical researchers have also been able to share gathered data more easily and this, in turn, has allowed researchers to achieve better modeling from their computations. SEE ALSO: Cancer (General); Gene Array Analysis; Genet-
ics; Genomic Library.
Bibliography. A.M. Campbell and L.J. Heyer, Discover-
ing Genomics, Proteomics and Bioinformatics (Benjamin/ Cummings, 2002); E.H. Davidson, Genomic Regulatory Systems: Development and Evolution (Academic Press, 2001). Justin Corfield Geelong Grammar School, Australia
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Biological and Chemical Weapons The ability to use certain biological and chemical agents as weapons is predicated on certain principles: The agent needs to be economically viable, it must be able to reach the target with limited collateral damage, and it must achieve the desired result. One additional element to make an element appealing as a weapon is the lack of treatment options or limited availability for antidotes, antibiotics, vaccines, active antibodies in immune globulin, or medications. Using these agents intentionally to cause harm and their release into the air, food, or water supply is bioterrorism, leaving first responders to identify whether an attack has occurred. During the Cold War, both the United States and the Soviet Union researched the possibility of using biological and chemical weapons. Terrorist attacks occurring within the last 30 years include the release of salmonella by the Rajneeshee Cult in Oregon into several salad bars and the water system in 1984, and anthrax spores mailed to Senator Tom Daschle’s office in Washington, D.C., in 2001. Similar attacks using a chemical weapon were the release of sarin gas into the Tokyo subway in Japan in the 1990s, which killed 12 people and injured 5,000, and in 1988 in Halbja, Iraq, Saddam Hussein released a chemical cocktail made up of mustard gas, sarin, tabun, and VX. This combination of a blister agent and nerve agents could not be treated. In response to the threat of terrorism, numerous world health and political organizations have listed the most likely biological and chemical weapons to be used for an attack. Biological Weapons Biological weapons are biological agents such as bacteria, viruses, or toxins with the potential to cause deadly illness leading to mass casualties and civil disruption. According to a 1993 North Atlantic Treaty Organization (NATO) handbook, 31 pathogens are considered to be possible weapons of mass destruction based on the criteria of virulence, effectiveness, and ease of dispersal or use. Other factors that determine whether an agent might be a viable weapon for terrorists are whether it can be easily procured
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or produced in a laboratory, is dispersible in aerosol form for maximum toxicity, and is able to survive conditions to reach the intended target. While a weapon could be as benign as a flu-type virus, the widespread results might be mitigated by the lack of severity of illness and perhaps lack of awareness the attack even occurred. Biological weapons are small and can be passed from person to person to cause a continuing outbreak. The result could be prolonged, and with new cases, new events, and the possibility for changing epidemiology, an outbreak would receive ongoing media attention. Smallpox was considered eradicated by the World Health Organization (WHO) in 1980, and WHO recommended that the vaccination no longer be given as standard procedure, meaning that the disease is unlikely to be contracted from a natural source. After the attacks with anthrax, the probability of smallpox being used as a weapon is high. It is highly contagious and hardy enough to remain stable and infectious in a variety of environments. The best treatment relies on early detection, isolation of infected persons, and focused selective vaccination. In 2002, the Centers for Disease Control and Prevention (CDC) recommended a three-phase vaccination plan to immunize first responders with smallpox vaccine. Anthrax is the common name of the bacterium Bacillus anthracis. When a person is exposed naturally by eating tainted meat or absorbing it through the skin from infected wool or hides, antibiotics are effective. As a potential biological weapon, anthrax can be easily grown on nutrients in the laboratory. When dried, the bacterium forms spores that can last in a variety of environments (hot, dry, or cold) and when reintroduced to the warm moist environment in the lungs after inhalation, the spores can germinate and cause illness and possible death within two to 10 days of exposure. Ciprofloxacin is considered the drug of choice for the strains of B. anthracis engineered for bioterrorism and is effective prophylaxis when given to persons with potential exposure. Plague is caused by the bacterium Yersinia pestis, a gram-negative rod with an incubation period of two to 10 days. The most toxic form and the one more likely to be used as a biological weapon results in pneumonic plague, which is contracted from inhaled droplets and causes kidney and respiratory failure. Antibiotic therapy of streptomycin, gentamicin, or doxycycline
should begin immediately and infected persons must be placed in strict respiratory isolation. Botulism is a paralytic disease caused by food-borne Clostridium botulinum. Release of the toxin throughout the body causes blurred vision and difficulty swallowing and speaking usually within 24 to 36 hours and can lead to general weakness, respiratory failure, and death. Diagnostic assistance and procurement of treatment in the form of botulinus antitoxin can be obtained from state health departments or the CDC. Tularemia is caused by Francisella tularensis. The bacterium is resistant to freezing, remains viable in water for weeks, and has a two- to 10-day incubation period. It can be contracted naturally through contact with animal tissues or ticks, with probable aerosol transmission. Due to virulence and ease of dissemination, it was added to lists of possible biological weapons. The symptoms produced are fever, headache, nausea, and prostration. It will likely develop a lesion at the inoculation site, either on the skin or the eyes. Treatment with the antibiotics streptomycin and tetracycline or chloramphenicol is effective. Hemorrhagic fever viruses from the arenavirus, filovirus, unyavirus, or flavivirus families target the vascular bed. Microvascular damage and changes in vascular permeability cause body fluids to leak out of tissues and orifices. The most feared in this category are the Ebola and Marburg viruses, as the vector remains unknown. Hemorrhagic fevers are most commonly disseminated by arthropod vectors (the bites of fleas and mosquitoes) and can be controlled with insecticide. Isolation is important and the use of universal precautions (gowns, masks, gloves, and eye protection) will help contain the virus. No specific treatment for hemorrhagic fevers exists except intravenous ribavirin for Lassa fever. Q-fever is transmitted to humans through inhalation or ingestion. The cause of infection is the rickettsiae Coxiella burnetii, which is resistant to heat and drying and survives in dust. Following an incubation period of one to three weeks, fever, headache, and muscle pain develop. Pneumonia, endocarditis, and central nervous system effects may occur. Treatment for acute infection with tetracycline or doxycycline can suppress symptoms and shorten the duration of clinical illness. Other such diseases include Brucellosis, which is transmitted from animals to humans with an incuba-
tion period of a few days to several weeks. The onset of illness includes fever, chill, and sweats. An infected person may not seek medical attention until they experience weakness, weight loss, and exhaustion. Combination antibiotic therapy is the most effective. Glanders caused by Burkholderia mallei is best treated with streptomycin and tetracycline or chloramphenicol and streptomycin. No vaccine exists. Typhus is an epidemic louse-borne infection caused by Rickettsia prowazekii. After an incubation period of 10 to 14 days the mild symptoms of the prodromal phase are followed by chills, high fever, delirium, and stupor. Treatment includes tetracycline or chloramphenicol. Prognosis is age related; in children the disease is mild; the mortality rate increases from 10 percent in persons aged 20–30 and rises to 60 percent by age 60. Vaccination provides some protection to decrease severity of illness. Ricin is an immunotoxin and the chief active compound found in castor beans. Ingesting the seeds can result in death in six to eight days. The symptoms of poisoning include nausea, vomiting, and diarrhea leading to dehydration and icterus. When inhaled, the response is more immediate and severe. Chemical Weapons Chemical weapons are chemical agents and fall into four categories: blister agents, nerve agents, choking agents, and blood agents. Most of these agents are delivered in the form of gases or vapors in chemical warfare. The toxic response is the rapid absorption into the body after inhalation. Technically, any chemical compound used as a weapon with intent to harm could be considered a chemical weapon. One such example is rubbing an arrow across the back of a poison frog from the Amazon. This chemical has now been classified as curare and the effect on the nervous system has been determined. Chemical agents have been used in warfare as early as World War I, when white phosphorous was used in grenades and mortar shells to cause thermal burns, and to mark targets. After surgery to remove particles and bathing in bicarbonate solution, a person poisoned by white phosphorus should be treated like any other burn victim. Nerve agents are potent compounds that cause cholinesterase inhibition; they are mostly organophosphate compounds similar to insecticides such
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as malathion but more potent. Many countries and terrorist groups have the capability to manufacture sarin, soman, tabun, GF, and VX. These agents can be inhaled or absorbed through the skin. Paramedics entering the contamination area must wear level A protective gear. Poisoning results are systemic with miosis, salivation, abdominal cramps, diarrhea, muscle paralysis, and respiratory arrest. Through the inhaled route, they also cause severe bronchoconstriction. Nerve agent victims must be decontaminated with water and then evaluated for the need to administer antidotes. Treatment includes atropine for muscarinic effects, pralidoxime for nicotinic effects, and benzodiazepines for central nervous system effects. While the only specific treatment is atropine given intravenously and repeated until the acetylcholine excess is reversed, additional treatment includes treatment with cholinesterase reactivating agent pralidoxime. During the Persian Gulf War, military personnel were issued self-injectables, including an initial dose of atropine/pralidoxime combination. Choking agents interfere with oxygen delivery. Chlorine gas is intermediately water soluble and reacts with water in the upper airways. At high concentrations, it may produce bronchospasm, pulmonary injury, and pulmonary edema. Treatment includes administration of oxygen and monitoring of pulmonary status. Phosgene gas is only slightly water soluble. It can be fatal after only brief exposure because it turns to hydrochloric acid in the lungs to cause pulmonary edema. Treatment is supportive only, with pulmonary monitoring, intubation, and ventilation as needed. Cyanide is a blood agent. It has a bitter almond odor and prevents cells from using oxygen. Death results from respiratory failure in eight to 10 minutes by inhalation. Treatment options include moving the poisoned person to fresh air or administering pure oxygen. Cyanide can also be used to contaminate a water supply. An antidote kit for cyanide should include amyl nitrite, sodium nitrite, and sodium thiosulfate. SEE ALSo: Anthrax; Bioterrorism; Botulism; Hemorrhagic
Fever; Smallpox.
Bibliography. Yonah Alexander and Milton Hoenig,
Super Terrorism: Biological, Chemical and Nuclear (Transnational Publishers, 2001); Ken Alibeck and Stephen
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Hundelman, Biohazard: The Chilling True Story of the Largest Covert Biological Weapons Program in the World—Told from Inside by the Man Who Ran It (Random House, 1999); Federation of American Scientists, “Chemical Weapons Information Table,” www.fas.org (cited January 2007); Bill Frist, When Every Moment Counts (Rowman & Littlefield, 2002); Judith Miller, Stephen Engleberg, and William Broad, Germs: Biological Weapons and America’s Secret War (Simon & Schuster, 2001). Lyn Michaud Independent Scholar
Biomarker A biomarker is a measurable and quantifiable biological parameter that serves as an indicator of a particular physiological state or of pharmacologic responses to a therapeutic intervention. In a medical context, a biomarker is a substance whose detection indicates a particular disease state, for example, the presence of specific pathological entities, cytological or histological characteristics, gene or chromosome mutations, particular transcripts of proteins, posttranslational variants, or alterations in the level of messenger ribonucleic acid (mRNA) and protein expression. Several decades of intensive research have produced molecular markers as tools for health-related assessments, epidemiologic studies, and the diagnosis of degenerative and disabling diseases, such as cancer, cardiovascular, neurological, and inflammatory diseases. The ability to effectively treat and cure a disease is often directly dependent on the capability to detect it at its earliest stage. Especially for cancer, there is an urgent need to improve early diagnostics, as it is often diagnosed in advanced stages, delaying timely treatment and leading to a poor prognosis. A cancer biomarker refers to a molecule that is indicative of the presence of cancer. It can be a specific response of the body or it can be secreted by the malignancy itself. With the recent developments in the fields of genomics and proteomics, there is an increasing interest in cancer risk assessment, monitoring progression, predicting recurrence, and determining the efficacy of therapeutic treatment. New technologies such as DNA and tissue microarray, two-dimensional
gel electrophoresis, mass spectrometry, and protein assays coupled with advanced bioinformatic tools are being applied to complex biosystems in order to uncover molecular mechanisms associated with cancer that may lead to new diagnostic tests and improvements in therapeutics. For clinical implementation and routine use, the ideal biomarker should be highly specific for a particular disease condition and should be measurable in easily accessible body fluids such as saliva, serum, or urine. Examples of routinely used biomarkers include CA 15-3 (breast cancer), CA 125 (ovarian cancer), and PSA (prostate cancer). However, such biomarkers are rare, and most candidate biomarkers are found in many different types of disease. In this case, biomarker pattern proteome analysis can be used to study the expression profiles of hundreds of proteins in parallel. Thus, several relatively nonspecific biomarkers can be combined in order to provide a more specific disease index. Proteomic pattern analysis based on mass spectrometry using the ProteinChip/SELDI-TOF platform holds special promise for the discovery of novel biomarkers as it distinguishes disease and disease-free states with high sensitivity and specificity. It allows an analysis of complex protein mixtures by combining two formerly well-established methods—solid phase chromatography and TOF-MS—for the conduction of expression difference mapping applications on one platform. Applying computational methods, the generated multiple proteomic spectra are superimposed to detect changes in protein expression and their association to disease conditions. Recent mass spectrometry technologic developments with high-throughput protein expression measurements permit the large-scale comparison of proteomic expression patterns of different clinical specimens. Up to now, investigators using these technologies in search of biomarkers, in particular for different types of cancer, mainly report on concentration changes and molecular modifications of abundant host response serum proteins. Recent studies on posttranslationally modified host response proteins and degradation products indicate that the identified modifications and degradation products are diseasespecific signatures. SEE ALSO: Bioinformatics; Cancer (General); Heart Diseases
(General); Infectious Diseases (General); Laboratory Tests.
Biosafety
Bibliography. John C. Bloom, Robert A. Dean, and
Bloom Bloom, eds., Biomarkers in Clinical Drug Development, Vol. 132 (Marcel Dekker, 2003); Daniel Hartmann, et al., “Identification of Potential Markers for the Detection of Pancreatic Cancer through Comparative Serum Protein Expression Profiling,” Pancreas (v.33/3, 2006). Daniel Hartmann University of Heidelberg
Biosafety Biosafety includes developing and implementing standards of practice, facility design, and use of safety equipment to protect the workplace, the public, and the environment from known and potentially infectious biological agents—microbes, viruses, toxins, and living modified organisms. The Centers for Disease Control and Prevention (CDC), Occupational Safety and Health Administration (OSHA), World Health Organization (WHO), United Nations Secretariat of the Convention on Biological Diversity, European Biosafety Society, and other organizations around the world work together to create biosafety standards, exchange information, make recommendations, and ensure regulatory control. A risk assessment for biological products identifies characteristics for potential harm, avenues of exposure, infection development, and the associated health consequences including treatment options such as antidotes, medications, and vaccines. To prevent exposure and adverse health complications, biosafety standards are employed based on the potential hazard. Four risk groups are classified by method of transmission, severity of infection, and prevention or treatment options. Risk level 1 organisms provide low risk to individuals or the community to cause disease in healthy adults. Risk level 2 organisms have minimal risk for spread of disease and have available treatment and preventive measures. Risk level 3 organisms cause serious or deadly disease to the individual but with little risk to the community. Risk level 4 organisms cause serious disease and are able to be passed to others in the community; treatment and preventive measures are not available.
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Procedures and Equipment Containment of infectious materials requires protection from the biological agent and utilization of appropriate handling procedures. Both factors in providing biosafety are only as good as implementation in daily practice. Communication of hazards, training in safety standards, provision of safety equipment, and protective gear reduce risks of exposure to pathogens. In the clinical or hospital setting, universal precautions prevent contamination from human blood, tissue, and fluids, except perspiration. Safety equipment used includes gloves, gowns, splash shields, and face protection. In the laboratory setting, safety precautions are specific to particular pathogens. Holding each worker responsible for following guidelines, policies, and procedures on a day-to-day basis increases the level of safety. Safety equipment provides a first barrier of defense between the biological agent and the worker and includes personal protective equipment and enclosed work areas called biological safety cabinets. Class I and class II biological safety cabinets provide good levels of protection when used with good microbiological techniques. Gas-tight class III biological safety cabinets provide the highest level of protection. The other immediate barrier is personal protective equipment worn on the person, which ranges from gloves, coats, and goggles to shoe covers, respirators, face shields, and air-supplied full-body suits. The second barrier of defense is facility design. To prevent the spread of disease by contact, facilities separate laboratory space from public areas, install decontamination equipment areas, and provide sinks for hand washing. To prevent the spread of disease by aerosol or droplet transmission, facilities control airflow and isolate laboratory space in separate buildings or restricted areas. Biosafety Levels In microbiological and biomedical laboratory settings, approval to work with the four different levels of pathogens is contingent on the laboratory’s ability to provide a safe environment for workers and to prevent release into the environment through appropriately engineered facilities, the installation of safety equipment, properly trained staff, and the implementation of specific practices and standards. Biosafety level 1 laboratories are teaching laboratories or those laboratories that work with non-
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disease-causing organisms in humans. Some of these relatively benign organisms may pose a health threat to immunosuppressed individuals. Level 1 laboratories require no additional safety equipment other than a sink for hand washing. Biosafety level 2 laboratories are for clinical or diagnostic laboratories and teaching laboratories working with indigenous pathogens within a community or group. Human biological samples, blood, body fluids, and tissues provide moderate risk. Viruses such as hepatitis B and human immunodeficiency virus (HIV) are included in this category. In addition to using universal precautions, sharp and contaminated instruments and products should be handled with caution and decontaminated and disposed of properly to avoid release into the environment. Biosafety level 3 laboratories include the above laboratories and research and production facilities working on indigenous and exotic pathogens transmitted by respiratory routes and known to cause lethal infection. Safety equipment must include biological safety cabinets and appropriate airflow controls and filtration. Viruses causing tuberculosis, Q fever, and viral encephalitis are examples of the types of pathogens at this level. Biosafety level 4 restricted access laboratories work with dangerous and exotic agents with high pathogenic risk and for which there is no available vaccine or therapy. These types of infectious agents include Ebola, Marburg, and other hemorrhagic fever microbials. The route of transmission is respiratory and requires class III biological safety cabinets or full-body protection suits with positive-pressure air to prevent contamination. Complete decontamination and the highest security measures must be taken to prevent accidental release. The facility should be separate from other buildings or in an isolated area with special ventilation and disposal precautions to prevent release. Established biosafety levels for infectious disease also work for laboratories using animals for experimental research. The animal biosafety levels 1, 2, 3, and 4 provide similar levels of protection as provided for in the previously described biosafety levels for work with human disease-causing pathogenic material. A biosafety level 3 for agriculture is in place for work with pathogens described by the United States Department of Agriculture (USDA) and such facilities are designed
with specific precautionary measures to be self-contained barriers for the prevention of release. Security of Pathogenic Organisms Traditional standards of biosafety focused on physical protection from laboratory-acquired infection. Since 2001, increased awareness of the potential for highly pathogenic agents to be used by terrorists added biosecurity to biosafety standards by restricting access, regulating transport, and preventing theft of select pathogens. Without measures in place to provide security for both specimen organisms and data, laboratories may be vulnerable to penetration for the purpose of harming workers or for the diversion of infectious material. Security must include screening of personnel, positive identification of employees before entering sensitive areas, and restricted access by approval to specific inventories of highly pathogenic organisms. When shipping or receiving pathogenic material, all regulations for accountability, packaging, labeling, and permits must be followed. This limits the possibility of pathogens falling into the wrong hands by accident or intent. Laboratories must report incidents of missing pathogens, environmental release, human exposure, and/or infection to the Department of Health and Human Services or the USDA. Continuous vigilance is imperative for workers to protect themselves, the public, and the environment from accidental release and infection by pathogens. The use of good microbiological technique and utilization of appropriate safety equipment as determined based on risk provides initial readiness. Evaluation of laboratory procedures, access issues, and types of pathogens being used should be included in emergency planning. An emergency is any adverse event or threat disrupting the safety precautions in place including fire, weather warnings, natural disasters, and power interruptions. Procedures for evacuation, containment, and notification of dangers to first responders and coordination with emergency and medical personnel for decontamination, therapeutic evaluation, and treatment are defined as needed. Global Implications An international protocol called the Cartagena Protocol on Biosafety was adopted by the Conference on Parties to the Convention on January 29, 2000, and
Bioterrorism
entered into force on September 11, 2003, after being ratified by 50 member states. As part of its objectives, the Cartagena Protocol on Biosafety established the Biosafety Clearing-House for information sharing; information includes a database for finding information on national contacts, risk assessments, organisms, and other resources. In addition to protecting public health, the Cartagena Protocol on Biosafety addresses trade and environmental protection issues surrounding new technologies including living modified organisms and genetic engineering. Networking, collaboration, and information sharing all help to reduce the possibility of exposure to pathogens and will provide safeguards to prevent adverse effects from the products of genetic modification. Biosafety relies on both formal and informal education, cooperation in the global scientific, medical, and regulatory communities, and adherence to established safety procedures and standards to prevent release, exposure, and misuse of pathogens and living modified organisms. With the increasing threat of terrorism, security and prevention of access to pathogenic agents must be addressed to reduce the potential for pathogenic organisms to be used as weapons. SEE ALSO: Agency for Toxic Substances and Disease Regis-
try (ATSDR); Biological and Chemical Weapons; Centers for Disease Control and Prevention (CDC); Disease Prevention; Disasters and Emergency Preparedness; Infectious Diseases (General); Occupational Safety and Health Administration (OSHA); World Health Organization (WHO). BIBLIOGRAPHY. Biosafety Clearing-House, www.bch.bio
div.org (cited May 2007); European BioSafety Association, www.ebsaweb.eu (cited May 2007); Jonathan Y. Richmond and Shanna L. Nesby-O’Dell, “Laboratory Security and Emergency Response Guidance for Laboratories Working with Select Agents,” Morbidity and Mortality Weekly Report (Centers for Disease Control and Prevention, December 6, 2002); U.S. Department of Health and Human Services, Biosafety in Microbiological and Biomedical Laboratories, 5th ed. (U.S. Department of Health and Human Services, 2007); World Health Organization, “Biorisk Reduction,” www.who. int/csr/bioriskreduction/en (cited May 2007). Lyn Michaud Independent Scholar
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Bioterrorism Bioterrorism is defined by the U.S. Centers for Disease Control and Prevention (CDC) as “the deliberate release of viruses, bacteria, or other germs used to cause death in people, animals, or plants.” Although it is not a new phenomenon, it has increasingly become a topic of international public concern, particularly after recent high-profile bioterrorism attempts in Japan and the United States. The ability of biological agents to infect large numbers of people, the difficulty of initially detecting an attack, and the threat that these agents will create widespread population disruption and panic present a unique set of challenges. Smallpox and anthrax, followed by plague, are generally considered to be the most likely biological agents. However, a host of other agents, including toxins produced by bacteria as well as viruses and bacteria, may also be deployed. International efforts to control bioterrorism began in 1925 with the Geneva Protocol. In 1972 a convention known as the Biological and Toxin Weapons Convention (BTWC) prohibited the development, production, stockpiling, and acquisition of biological and toxin weapons. Since then, the majority of the world’s countries have signed on to the convention. The use of biological weapons is far from new. In fact, one of the earliest incidences of bioterrorism is thought to have occurred in the 6th century b.c.e. when Assyrians poisoned enemy wells with rye ergot, a fungus that can cause convulsions if ingested. In 1346, plague broke out in the Tartar army while it was besieging the city of Kaffa in Crimea. Reportedly, the Tartars hurled the bodies of plague victims over the city walls, causing an epidemic that forced the city to surrender. It is postulated that infected Kaffa residents may have been the source of the black plague that subsequently swept across medieval Europe. In the 1700s, during the French and Indian wars, the British reportedly gave blankets that had been used by smallpox victims to Native Americans, igniting smallpox epidemics that decimated the Native American population. Biological weapon use and development in the 20th century include the 1915 use of glanders bacteria and anthrax by German undercover agents to inoculate livestock from the United States bound for Allied countries. From the 1930s through 1945, the Japanese set up a biological warfare testing center, known as Unit 731, in occupied Manchuria. Here, thousands
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Smallpox and anthrax are often considered the most threatening biological agents because of their relative ease of production.
of prisoners and Chinese nationals were used as experimental subjects for developing and testing biological weapons. During the early 1940s, the Japanese dropped plague-infected fleas over China and Manchuria, causing outbreaks in these areas. In 1942, both the United States and United Kingdom (UK) began biological weapon research programs of their own, at Camp Detrick, Frederick, Maryland, and Gruinard Island off the coast of Scotland, respectively. Testing of anthrax spore dissemination through conventional bombs on Gruinard Island resulted in contamination so great that the entire island eventually had to be decontaminated with formaldehyde and seawater. The UK bioweapon development program was eventually terminated, and in 1969, President Richard Nixon signed an executive order to stop all offensive biological and toxin weapon research and production. In 1984, the Rajneeshee cult in the United States deliberately contaminated salad bars in an Oregon town with salmonella, sickening hundreds of people. In 1995, the Japanese Aum Shinrikyo cult attempted on several occasions to release biological agents, including anthrax, before finally releasing the chemical nerve agent sarin in the Tokyo subway. After the first Gulf War, the Iraqi government admitted that Iraq had a biological weapons development program, although thus far, no evidence has supported the continuation of that program after the war. Finally, in
2001, anthrax-containing letters were mailed by an as-yet-unidentified source. Twenty-two people were infected, 11 with cutaneous anthrax and 11 with inhalation anthrax. Five cases were fatal. Anthrax and smallpox are often discussed as the most threatening biological agents because of their relative ease of production, infectivity, and toxicity, although a host of other agents exist. The CDC divides biological agents into category A, category B, and category C. Category A agents (e.g., anthrax, plague, smallpox, botulism toxin, tularemia, hemorrhagic fevers such as Ebola) are considered high risk because they can easily be spread or transmitted from person to person, result in high death rates, require special action for public health preparedness and management, and have the potential to cause widespread public panic and social disruption. Category B agents (e.g., ricin, glanders bacteria, brucella) are lower priority; they are only moderately easy to spread and result in moderate illness and low death rates. Category C agents are emerging pathogens that could be engineered for mass spread in the future (e.g., hantavirus or multidrug-resistant tuberculosis). Much attention is focused on biological agents that directly infect humans. However, it is important to remember that agents that destroy a nation’s food supply could also be devastating and disruptive to society. Aggressive forms of plant fungi, for example, could destroy swaths of crops in a relatively short period of time, and agents directed at livestock could wipe out cow, sheep, pig, or chicken populations. Aside from food security issues, this would be economically devastating to agricultural industries. Anthrax Anthrax (Bacillus anthracis) infects grazing mammals such as sheep, cattle, and goats when they ingest soil contaminated with B. anthracis spores. Outside of the bioterrorism context, human infection with anthrax, “wool sorter’s disease,” is usually the result of contact with infected animals or anthrax-contaminated animal products. The most dangerous form of infection is inhalation anthrax, in which aerosolized anthrax spores pass into the lungs. Here, they eventually germinate, sometimes after a lag time of several weeks, producing toxin-making bacteria. Initial symptoms are very nonspecific: Victims may have a low fever, cough, some muscle
aches, headache, vomiting, weakness, chills, abdominal pain, or fatigue. Patients may seem to recover but then progress to the second, more serious phase of the disease in which they suddenly present with high fever and chills, great difficulty in breathing, and shock. By the time these symptoms develop, therapy is usually ineffective, and death occurs within 24 to 72 hours in almost 90 percent of cases. Inhalation anthrax is the most alarming in terms of use as a bioweapon. It is possible for spores to be disseminated (e.g., inside a bomb that explodes in midair) through aerosol over a large, densely populated area with devastating effects. Because initial symptoms are very difficult to distinguish from an innocuous viral illness, a diagnosis might not be made until a patient is extremely sick. A less serious form of anthrax is cutaneous anthrax, which may develop from contact of broken skin with spores. If left untreated, the infection will manifest as a large, blackened ulcer. However, the mortality rate is lower than for inhalation anthrax. Anthrax infections in the stomach or throat are rarely reported. Treatment of anthrax is with antibiotics, which can be given prophylactically or once infection is detected. An anthrax vaccine exists and is used to protect animals and people at increased risk of exposure such as military personnel, but has significant toxicities that make it unacceptable for vaccination of large populations. Smallpox Smallpox is seen as one of the most likely viruses to be used as a biological weapon. It is extremely infectious, and was particularly devastating to Native American populations in North and South America when it was brought to the continent by European explorers. Through a vaccination campaign, it was declared eradicated worldwide by the World Health Organization (WHO) in 1980. Vaccination was completely discontinued in the United States after 1980. The last fatal case was due to a laboratory-acquired infection in the UK in 1978. The virus still legitimately exists in two laboratories in the world: the CDC in Atlanta, Georgia, and the State Research Center of Virology and Biotechnology in Novosibirsk, Russia, although there are concerns about clandestine stocks that may exist in other places. There is debate over whether to destroy these last stocks, but thus far, the WHO has decided to delay destruction.
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Transmission is primarily person to person through respiratory routes, although infection from contact with dried virus on cloth or other materials is also possible. The virus may remain stable for up to a year in dust and cloth. About 10 days after infection, patients develop severe headache, backache, and fatigue, followed by lesions in the mouth and characteristic pox all over the body. Lung infection, damage to the eyes, and infection of the bones, brain, and testes are all possible complications. The mortality rate is 30 percent in unvaccinated individuals, and 3 percent in vaccinated individuals. Hemorrhagic-type smallpox is a more virulent form that causes death in over 90 percent of both vaccinated and unvaccinated individuals. There is no established treatment for smallpox, and vaccination has been largely discontinued in the United States and around the world since 1980, rendering millions of people vulnerable to the virus. The original vaccine does not meet current quality standards and had some significant side effects, so there are currently efforts underway to develop a safer vaccine. The virus could be delivered via aerosol as a biological weapon. Plague Most experts consider anthrax and smallpox to be the greatest threats. However, plague also appears to be a candidate for bioterrorist attack. It could be disseminated in an aerosol form, similar to anthrax and smallpox, or it could be used to infect rodents. Fleas feeding on the rodents could then transmit the bacteria to humans, much as they did during the massive Black Death outbreak that decimated medieval Europe. Plague-infected fleas could also conceivably be released. Plague occurs in several forms, but the most likely from an aerosol attack would be primary pneumonic plague. This occurs through inhalation of bacteria and begins abruptly after a one-to-six-day incubation period with intense headache, fever, diarrhea, vomiting, and abdominal pain. Lung infection with respiratory failure and shock develops quickly. Without antibiotics, patients typically die within two to three days. Plague pneumonia is extremely contagious via respiratory droplets. However, with antibiotics, the mortality rate decreases below 10 percent. Bubonic plague from an infected flea bite presents similarly, but a large swelling of a lymph node near the bite, a “bubo,” is characteristic. Mortality is around 60 percent, but reduces to less than 5 percent with antibiotics. There is a
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vaccine available, but due to associated risks, it is not considered safe for use in large human populations. Antibiotics are very effective at treating plague. International Controls The first effort to prohibit the use of biological agents was contained in the 1925 Geneva Protocol, signed at the end of World War I. This specified that no country should use biological weapons unless first attacked with a biological agent. However, it said nothing about research or development of biological agents. In contrast, the Biological and Toxin Weapons Convention (BTWC), signed on April 10, 1972, banned the stockpiling, development, acquisition, and use of biological agents and toxins for nonpeaceful purposes. Currently, over 150 countries have signed on. However, some point out that the BTWC lacks verification provisions and parties are very little constrained to provide information on certain activities that are “legitimate,” such as pharmaceutical plants, but have the capacity to be used to produce biological weapons. Many countries around the world have begun to prepare for the possibility of bioterrorism. In the United States, for example, Congress passed the Public Health Security and Bioterrorism Preparedness and Response Act (“Bioterrorism Act”) in 2002, which provides guidelines for biosafety and the development of appropriate responses to bioterrorist attacks. It is unclear how likely it is that a major bioterrorist attack will occur. However, the prospect of bioterrorism will no doubt be a cause of concern for years to come. SEE ALSO: Anthrax; Biodefense; Biological and Chemical
Weapons; Biosafety; Botulism; Disasters and Emergency Preparedness; Hemorrhagic Fever; Infectious Diseases (General); Smallpox. Bibliography. Arizona Department of Health Services,
“History of Biowarfare and Bioterrorism,” www.azdhs. gov (cited February 2007); P. Bossi, et al., “Bioterrorism: Management of Major Biological Agents,” Cellular and Molecular Life Sciences (v.63, 2006); Centers for Disease Control and Prevention Emergency Preparedness and Response Section, www.bt.cdc.gov (cited February 2007); Donald Henderson, “The Looming Threat of Bioterrorism,” Science (v.283/5406, 1999); N.F. Lightfoot and R.C.
Spencer, “Preparedness and Response to Bioterrorism,” Journal of Infection (v.43, 2001); National Public Radio, “History of Biological Warfare,” www.npr.org (cited October 18, 2001); Paul Rogers, Simon M. Whitby, and Malcolm Dando, “Biological Warfare against Crops,” Scientific American (v.280/6, 1999). Susan Tuddenham Independent Scholar
Biotherapy Biotherapy involves the use of living animals or insects for medical treatment or to help with medical diagnosis. This has always been a controversial area of medicine; it was popular in medieval and early modern Europe, and is still used in some instances. Technically, the use of guide dogs to assist blind people may also be regarded as an extension of biotherapy. Traditionally, the most well-known use of biotherapy in medieval and early modern Europe involved the application of leeches. Much Roman and European medieval medical diagnosis centered on treatment of blood, often involving the shedding of blood to “purge” what was known as “bad blood,” or what is now recognized as being high blood pressure or blood clots. Accounts of the use of leeches are also found in the Indian Sanskrit writings of Caraka and Susrua in the first century c.e. The Roman physician Galen (129–216 c.e.) also mentioned leeches, and their use was common into the 19th century in Europe, Asia, and the Americas. medicinal leeches This generally involved the European medicinal leech (Hirudo medicinalis). The leech has three jaws and 100 sharp teeth, and uses the anticoagulant hirudin, first identified in 1884, and isolated in its purified form for the first time in the 1950s. The use of leeches used to be known as leeching, but is now known as hirudotherapy. The main use of leeches by modern surgeons is after reattaching severed body parts such as fingers or after a tissue graft procedure. Leeches can be applied to areas where an anticoagulant is needed and can be used to help circulation throughout the attached body part. There have been a number of other ani-
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mals used for biotherapy, including maggots (maggot debridement therapy and larva therapy), honey bees (apitherapy), fish (ichthiotherapy), and worms (helmitherapy). Maggots, leeches, and fish have been used in the saving of limbs, dogs may be used to detect cancers, and bee venom can be helpful in neurological and musculoskeletal diseases.
Bibliography. Ralph E. Parchment, “Biotherapy,” in
SEE ALSO: Blindness; Blood/Blood Transfusion; Cancer
Justin Corfield Geelong Grammar School, Australia
(General).
Robert G. McKinnell, ed., The Biological Basis of Cancer (Cambridge University Press, 1998); Roy T. Sawyer, Leech Biology and Behaviour (Oxford University Press, 1986); Annie Young, Lewis Rowett, and David Kerr, eds., Cancer Biotherapy: An Introductory Guide (Oxford University Press, 2006).
Biotherapy has always been a controversial area of medicine; it was popular in medieval and early modern Europe, and is still used in some instances. Technically, the use of guide dogs to assist blind people may also be regarded as an extension of biotherapy.
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Bird Flu
Bird Flu Bird flu, also known as avian influenza, is an infection by avian influenza viruses, which are transmitted from wild birds to domesticated birds, and from domesticated birds to human beings. This infection was first reported in 1997 in Hong Kong, then reemerged in 2003 in southeast Asia and spread across Asia, the Middle East, Africa, and Europe. Since its emergence, it has infected about 249 people and killed 180 worldwide, with the most deaths in 2005 and 2006. It caused panic at a global level and mobilized scientific and medical experts as well as politicians and lay people. The term human influenza virus usually refers to the subtypes that spread widely among humans. There are only three known A subtypes of influenza viruses (H1N1, H1N2, and H3N2) currently circulating among humans. It is likely that some genetic
parts of current human influenza A viruses originally came from birds. Bird flu is caued by the influenza A(H5N1) virus, or the H5N1 virus, which occurs mainly in birds. Medical researchers found that most human cases have resulted from people having close contact with poultry infected with the H5N1 virus or H5N1-contaminated surfaces. When the first confirmed cases of human infection from several subtypes of avian influenza were reported in Hong Kong in 1997, there were 18 patients, six of whom died. The disease reemerged in China’s Fujian Province in 2003, with two human patients, one of whom died. It also appeared in Vietnam in three human patients, all of whom died. In late 2003 and early 2004, more outbreaks of avian influenza were detected in eight countries: Cambodia, China, Indonesia, Japan, Laos, South Korea, Thailand, and Vietnam. Mass killings of infected birds
When wild birds have close contact with domesticated birds, such as chicken, ducks, and turkeys, avian influenza can be easily spread to the domesticated birds and can make them very sick and kill them in a short period of time.
began in order to control the outbreaks; more than 100 million birds in the affected countries either died from the disease or were killed to limit its spread. By March 2004, the outbreak was reported to be under control. New outbreaks of bird flu among poultry and wild birds occurred in Asia in June 2004, and for the same year the World Health Organization (WHO) reported 46 cases in Thailand and Vietnam of humans infected with bird flu, 32 of whom died. In 2005 and 2006, following the wild birds’ migration routes, the disease quickly spread to the birds of Asia and central Asia (Indonesia, Russia, Kazakhstan, and Azerbaijan), the Middle East (Turkey and Iraq), Africa (Djibouti) and Europe (Greece, Italy, France, Germany, and the United Kingdom [UK]). This also led to an increase in cases of bird flu among humans, mostly in Indonesia, Thailand and Vietnam. Avian influenza viruses occur naturally among birds, and wild birds worldwide carry the viruses in their intestines without getting sick from them. However, when wild birds have close contact with domesticated birds, such as chicken, ducks, and turkeys, avian influenza can be easily spread to the domesticated birds and can make them very sick and kill them in a short period of time. Infected birds shed influenza virus in their saliva, nasal secretions, and feces. Susceptible birds become infected as a result of having contact with contaminated secretions or excretions or with surfaces that have come into contact with these substances. Besides human beings, pigs, ferrets, tigers and leopards in zoos in Thailand, and domestic cats (who were fed raw infected chickens under experimental conditions in Germany) have also been infected with bird flu. Bird flu occurs in domestic birds in two main forms, which are distinguished by low and high extremes of virulence. The “low pathogenic” form is often undetected, since it usually causes only mild symptoms, such as ruffled feathers and a drop in egg production. The “highly pathogenic” form spreads rapidly through flocks of poultry, affects multiple internal organs, and has a mortality rate that can reach 90 to 100 percent, often within 48 hours. While in most cases people are infected with the H5N1 virus through contact with H5N1-infected poultry or H5N1-contaminated surfaces, given the survival of influenza A(H5N1) virus in the environment, several other modes of transmission are theo-
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While bird flu has killed only 180 people worldwide, a change in its form could precipitate a worldwide influenza pandemic.
retically possible. For instance, oral ingestion of contaminated water during swimming and inoculation through the nose and eyes during exposure to water are other potential modes. The widespread use of untreated poultry feces as fertilizer is another possible risk factor. The spread of bird flu viruses from one ill person to another has been reported very rarely, and it did not continue beyond one person. Bird flu is often seen among members of families who live in crowded conditions in the same houses with their domesticated birds, or who are constantly exposed to the virus in rural areas. Most patients have a history of direct contact with poultry, particularly plucking and preparing of diseased birds, handling fighting cocks, playing with poultry (especially ducks), and consumption of duck’s blood or possibly undercooked poultry. A group of researchers at the University of Wisconsin has a possible explanation for why the deadly H5N1 bird flu virus cannot yet jump easily between humans. Flu viruses that target humans tend to attach to cells further up in the airway in order to maximize their chances of being passed on by coughing and sneezing. However, the researchers found that the bird flu virus attaches itself to cells deep in human airways. The virus tends to be buried so deep in the lungs that it is unlikely to be spread by coughing and sneezing. Professor Ian Jones of the University of Reading, UK, argues that the Wisconsin study provides some explanation of why people, particularly children, had
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caught the virus and died; yet it had remained “bird flu.” According to Jones, the Wisconsin research indicates that the humans affected with bird flu were unlucky and transmitted enough virus to their mouths for it to reach the lower lungs, a distance shorter in children than adults. Therefore, having casual contact with the virus may not be as dangerous as initially thought; there have been relatively low frequencies of bird flu in humans despite widespread exposure. Scientists suspect that clusters of bird flu cases among members of the same families, while they might be related to common exposure, might also be connected to genetic factors that may affect hosts’ susceptibility to the disease. In order to prevent transmission of the bird flu to human beings, several measures have been taken, such as the U.S. ban on the importation of birds and bird products from H5N1-affected countries in Asia, Africa, and Europe, and the establishment of international guidelines on how to handle and cook poultry and eggs. The guidelines include washing hands with soap and warm water for at least 20 seconds before and after handling raw poultry and eggs, cleaning cutting boards and other utensils with soap and hot water to keep raw poultry from contaminating other foods, using a thermometer to make sure that poultry is cooked to a temperature of at least 165 degrees F (74 degrees C), and cooking eggs until the whites and yolks are firm. The Centers for Disease Control and Prevention (CDC) does not recommend any travel restrictions to H5N1-affected countries, but it advises travelers to those countries to avoid visiting poultry farms or having contact with animals in live food markets or with any surfaces that appear to be contaminated with feces from poultry or other animals. Eating meat or eggs that are sold in the streets or in places that seem unhygienic is also not recommended for travelers to those countries. symptoms and Diagnosis The most common symptoms of bird flu in humans range from typical human influenza-like symptoms, such as fever, cough, and sore throat, to eye infections, pneumonia, respiratory diseases, and other severe and life-threatening complications. The relatively less common initial symptoms are diarrhea, vomiting, abdominal pain, and bleeding from the nose and gums. The symptoms are generally seen in two to five days
after exposure, but the upper limit is eight to 17 days, possibly owing to unrecognized exposure to infected animals or environmental sources. Death occurs within an average of nine or 10 days after the onset of illness, and most patients died of progressive respiratory failure. Infection has caused high rates of death among infants, children, and young adults. Avian influenza cannot be diagnosed without a proper laboratory test for humans; it is usually diagnosed by collecting a swab from the nose or throat during the early days of the illness. In the laboratory, avian influenza is either detected by using a molecular test or by growing the virus, which can only be done in laboratories with high levels of protection. If it is late in the illness, it is harder to detect avian influenza, but it can still be diagnosed by looking for evidence of the body’s response to the virus. Treatment and vaccines In treating avian influenza, several prescription medicines that are approved for human influenza work to some extent, depending on the time of diagnosis and the patient’s general physical condition. The drug Tamiflu proved the most effective commercial drug against bird flu, and the WHO distributed capsules for free in several countries in Asia where many people cannot afford the drug, such as Indonesia, China, Vietnam, and Thailand. Thirty million capsules were distributed from 2005 to 2006. Although there is no commercially available vaccine to protect humans against the H5N1 virus, vaccine development efforts are taking place in different parts of the world, such as the United States and China. The first research studies to test a vaccine against bird flu started in April 2005 and were followed by a series of clinical trials. In September 2006, a vaccine developed in China was proven to be safe and effective at low doses against the H5N1 virus. The vaccine tested in that new study contained a modified form of the whole H5N1, plus the adjuvant aluminum hydroxide. The researchers of that study work at reducing the vaccine’s common side effects, such as pain, swelling, and fever. Despite the rapid scientific developments to prevent bird flu, scientists are concerned that H5N1 virus may change, since all influenza viruses have that ability, and may begin to spread easily from one person to another. Moreover, the World Organization for Ani-
Bird Flu
mal Health (OIE) reports that several Asian and African nations underreport cases of bird flu because of the lack of adequate veterinary facilities and adequate compensation schemes for the farmers with infected poultry. Both the WHO and OIE state that full-scale international cooperation is needed in economic and social terms in order to solve these problems and raise global awareness about bird flu and how to prevent it among humans and domesticated birds. International Mobilization The quick spread of bird flu among both birds and humans in late 2005 and early 2006 caused worldwide alarm. Several international organizations, such as the WHO, the CDC, and OIE, initiated research on the infection in order to understand its transmission patterns and to find efficient ways to eradicate the disease. Scientists from different countries held an international conference, “Case Management and Research on Human Influenza A/H5,” in Hanoi, Vietnam, in May 2005 in order to help initiate international scientific cooperation. A similar international meeting was held in Beijing, China, in January 2006, and it focused on international funding for research on bird flu and for the affected countries, where mass killings of poultry had taken place. The United Nations declared bird flu a global threat and called for funding of $1.5 billion; the World Bank and the European Union answered that call by donating $500 million and $80 million, respectively. Ministries of health, hospitals, laboratories, and related faculties of universities were also mobilized in order to fight bird flu in affected countries. These institutions prioritized rapid detection of human infections, finding an effective cure, and issuing guidelines on how to avoid bird flu. In large countries such as Russia, China, and Turkey, politicians and scientists used mass media (especially television and newspapers) and cooperated with well-known public figures and religious leaders to increase awareness of bird flu. These efforts went together with the mass killings of potentially infected poultry in areas where bird flu had been detected in poultry or in human beings. Government authorities, advised by medical authorities, conducted most of the killing and disposal of the poultry in affected countries in proper ways, often by burning or burying it. In Asian countries, such
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as Thailand, Vietnam, and Indonesia, where there is considerable rural poverty, bird flu surveillance is particularly hard, since many farmers’ economic subsistence depends on the poultry they raise, and they may be reluctant to report sick chicken or ducks to the authorities. The CDC started a $5.5 million initiative to improve influenza surveillance in Asia, and collaborated with the WHO in providing help in laboratory diagnostics and training to local authorities, as well as investigating bird flu in infected people. Global economic inequalities hinder efforts to detect bird flu to a considerable extent. Large sums of money have been donated, but there are still problems in ensuring their worldwide distribution and effective use. The WHO indicates the need for a more regular funding and payment plan from developed countries so that the research on bird flu and early detection systems can work more effectively in the long run. The problem of bird flu has also cultural and social aspects. International organizations need to fully cooperate with national and local medical and political authorities. While looking for cases of bird flu and eradicating affected poultry, medical and political authorities should be sensitive about the cultural and social characteristics of the people, taking into account their living arrangements, eating habits, and conceptions of privacy. These issues are particularly important in places where bird flu is endemic and is permanently affecting poultry, such as in Java, Indonesia, where the people may feel reluctant to report every outbreak. Scientists are also concerned about the problems of detecting bird flu in wild animals, especially migrating birds and forest animals. Besides these problems, scientists’ biggest concern remains that the bird flu virus may change form and gain the capacity to spread easily from one person to another. In that case, a worldwide influenza pandemic could occur, since there is little or no immune protection against the H5N1 virus in the human population. However, partly because of the threat of this worst case scenario, experts from around the world are watching the virus and its transmission patterns in Europe and Asia extremely closely, as well as trying to find the most efficient medication and vaccination against bird flu. SEE ALSO: Food Safety; Influenza; World Health Organi-
zation (WHO).
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Bibliography. BBC News, “Clue to Slow Human Bird
Flu Jump,” www.news.bbc.co.uk (March 22, 2006); Centers for Disease Control and Prevention, “Key Facts about Avian Influenza (Bird Flu) and Avian Influenza A(H5N1) Virus,” www.cdc.gov/flu/avian (cited June 2006); Matt McGrath, “Nations Under-Report Bird Flu,” BBC News, www .news.bbc.co.uk (cited July 31, 2006); Robert Preidt, “LowDose Bird Flu Vaccine Effective: Chinese Team Reports Success with New Formulations,” MedLine Plus, www .nlm.nih.gov/medlineplus/news (cited September 2006); Writing Committee of the World Health Organization Consultation on Human Influenza A/H5, “Avian Influenza A(H5N1) Infection in Humans,” New England Journal of Medicine (v.353, 2005). Aysecan Terzioglu City University of New York
Birth Cohort A birth cohort is defined as a group of individuals born at or around the same time. These cohorts are defined in studies to examine the impact of generation-specific factors that influence members of these cohorts. Differences in disease incidence are due to either exposures common to the birth cohort (e.g., early childhood disease that confers later immunity to diseases such as tuberculosis), the influence of early nurture (e.g., availability of child care for young children has a potential impact on later development), or events that have an age-specific impact later in life (e.g., adult women’s consumption of calcium has a later impact on fractures). An early example of a study that takes into account birth cohort effects is epidemiologist Wade Hampton Frost’s examination of tuberculosis mortality trends by year of birth, an analysis that suggested that early childhood disease imparted later immunity to tuberculosis. Since then, birth cohort studies have been used to describe associations between birth year and later incidence of peptic ulcer, breast cancer trends, and reproductive health. Large birth cohorts recruit a cross-section of individuals at or near birth and follow them over their life course. These are assembled for the purposes of studying exposures with long time lapse, and are potentially
important for studying etiology of chronic diseases or other conditions that are impacted by longtime exposure. Current examples include the Early Childhood Longitudinal Study (United States), British Cohort Study (United Kingdom), and several birth cohort studies that are being undertaken in developing countries, including the Pelotas birth cohort study in Brazil and the Mexican Health and Aging Study. SEE ALSO: Cohort Study. BIBLIOGRAPHY. Wade H. Frost, “The Age Selection of Mor-
tality from Tuberculosis in Successive Decades,” American Journal of Hygiene: Section A (v.30, 1939); Kenneth Rothman and Sander Greenland, eds., Modern Epidemiology (Lippincott Williams & Wilkins, 1998); George D. Smith and Diana Kuh, “Commentary: William Ogilvy Kermack and the Childhood Origins of Adult Health and Disease,” International Journal of Epidemiology (v.30, 2001). Constance W. Liu, M.D. Case Western Reserve University
Birth Control/Contraception Birth control is a regimen of one or more actions, devices, or medications followed in order to deliberately prevent or reduce the likelihood of a woman becoming pregnant or giving birth. Mechanisms that are intended to reduce the likelihood of the fertilization of an ovum by a spermatozoon may more specifically be referred to as contraception. Methods of birth control that may prevent the implantation of an embryo if fertilization occurs are medically considered to be contraception but characterized by some opponents as abortifacients. Contraception differs from abortion in that the former prevents fertilization, while the latter terminates an already-established pregnancy. Methods and intentions typically termed birth control may be considered a pivotal ingredient to family planning. In recent decades, there have been tremendous advances in the development of safer and more effective contraceptives, and in the provision of affordable and accessible family planning services. Yet, millions of individuals and couples around the world are still unable to plan their families as they
wish. It is estimated that over 120 million couples do not use contraceptives despite wanting to space or limit their childbearing. In addition, many women who use contraceptives nevertheless become pregnant while other couples who want to have children are unable to conceive. There remain many causes behind unmet needs for family planning services, despite the tremendous increases in options for birth control. First, there might be a lack of services or barriers to their access. Even if there is access to services, the poor quality of services, such as suboptimal interactions between clients and providers, substandard technical competence of providers, inadequate information, and poor design and management of service delivery systems may result in inadequate provision of services for family planning. Moreover, the culprit is increasingly technology issues, such as limited or inappropriate choice of methods and fear, or experience, of side effects. Finally, there may be broader social issues, such as an individual’s lack of knowledge, power imbalances within couples and families, and sociocultural, religious, and gender barriers. Despite the fact that it is generally less controversial than abortion, in many religions and cultures, birth control is a controversial political and ethical issue. Birth control has many opponents, with varying degrees of opposition. There are some opponents who oppose all forms of birth control short of sexual abstinence. Then, there are those who oppose forms of birth control they deem “unnatural,” while allowing natural birth control. There are also those who support most forms of birth control that prevent fertilization but oppose any method of birth control that prevents a fertilized embryo from attaching to the uterus and initiating a pregnancy. Religions vary widely in their views of the ethics of birth control. In Christianity, the Roman Catholic Church accepts only natural family planning, while Protestants maintain a wide range of views from allowing none to very lenient. Views in Judaism range from the stricter Orthodox sect to the more relaxed Reformed sect. In Islam, contraceptives are allowed if they do not threaten health or lead to sterility, although their use is sometimes discouraged. Hindus may use both natural and artificial contraceptives. There are historic records of Egyptian women using a pessary (a vaginal suppository) made of various acidic substances and lubricated with honey or oil,
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which may have been somewhat effective at killing sperm. However, the sperm cell was not discovered until Anton van Leeuwenhoek invented the microscope in the late 17th century, so barrier methods employed prior to that time could not have made use of the details of conception. Asian women may have used oiled paper as a cervical cap, and Europeans may have used beeswax for this purpose. The condom appeared sometime in the 17th century, initially made of a length of animal intestine. It was not particularly popular nor as effective as modern latex condoms, but was employed both as a means of contraception and in the hopes of avoiding syphilis, which was greatly feared and devastating prior to the discovery of antibiotic drugs. The fact that various effective methods of birth control were known in the ancient world sharply contrasts with the wide segments of the population of early modern Christian Europe. This ignorance continued far into the 20th century, and was paralleled by high birth rates in European countries during the 18th and 19th centuries. Forms of Contraception Probably the oldest methods of contraception (aside from sexual abstinence) are coitus interruptus, certain barrier methods, and herbal methods (emmenagogues and abortifacients). Coitus interruptus (literally interrupted sex), also known as the withdrawal method, is the practice of ending sexual intercourse (“pulling out”) before ejaculation. The main risk of coitus interruptus is that the man may not make the maneuver in time. Although it is commonly believed that preejaculate fluid can cause pregnancy, modern research has shown that preejaculate fluid does not contain viable sperm. Sexual abstinence is the practice of refraining from all sexual activity. As with avoiding intercourse, the intention to remain abstinent may not prevent pregnancy due to the level of discipline required. The risk of pregnancy from nonvaginal sex, such as outercourse (sex without penetration), anal sex, or oral sex is low. (A very small risk comes from the possibility of semen leaking onto the vulva [with anal sex] or coming into contact with an object, such as a hand, that later contacts the vulva.) However, with this method, discipline is required to prevent the progression to intercourse. Forms of spermicide, foams, creams, and jellies, and suppositories placed near the cervix before sexual
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intercourse work by killing sperm before they enter the uterus. Creams and jellies come in plastic tubes and are inserted with a plastic applicator. Foams come in aerosol cans along with an applicator, and have the consistency of shaving cream. Suppositories are also available and are inserted into the vagina. The rhythm method (with a rather high method failure rate of 10 percent per year) was developed in the early 20th century, as researchers discovered that a woman only ovulates once per menstrual cycle. Not until the mid-20th century, when scientists better understood the functioning of the menstrual cycle and the hormones that controlled it, were oral contraceptives and modern methods of fertility awareness (also called natural family planning) developed. Barrier methods place a physical impediment to the movement of sperm into the female reproductive tract. The most popular methods are the male condom, a
Hormonal contraceptives, if used strictly, have failure rates of less than 1 percent per year, but typical use failure rates are up to 8 percent.
sheath worn over a man’s penis to catch sperm and prevent them from entering the woman’s vagina. Condoms can help prevent the spread of some sexually transmitted diseases, including AIDS. The female condom is a strong, soft, polyurethane sheath with a flexible ring at each end. It is inserted into the vagina prior to intercourse and provides protections against both pregnancy and sexually transmitted diseases. The inner ring aids insertion and secures the device in place while the softer outer ring remains outside of the vagina. Cervical barriers are devices that are contained completely within the vagina. The cervical cap is the smallest cervical barrier. It stays in place by suction to the cervix or to the vaginal walls. The Lea’s shield is a larger cervical barrier, also held in place by suction. A diaphragm is a round rubber dome that is placed inside the vagina to cover the cervix and block sperm from entering. It is meant to be used in combination with a spermicide to reduce the risk of pregnancy. The sponge is a flexible device made of polyurethane and saturated with spermicide. It is placed into the vagina, and prevents pregnancy by blocking the entryway to the uterus and absorbing and trapping sperm. There are a variety of delivery methods for hormonal contraception. Combinations of synthetic estrogens and progestins (synthetic progestogens) are commonly used. These include the combined oral contraceptive pill (“the pill”), the patch, and the contraceptive vaginal ring (NuvaRing®). Not currently available for sale in the United States is Lunelle, a monthly injection. Other methods contain only a progestin. These include the progestin-only pill (the POP or “mini pill”), the injectables Depo-Provera® (a depot formulation of medroxyprogesterone acetate given as an intramuscular injection every three months) and Noristerat® (norethisterone acetate given as an intramuscular injection every eight weeks), and contraceptive implants. The progestin-only pill must be taken at more precisely remembered times each day than combined pills. The various progestin-only methods may cause irregular bleeding while being used. Intrauterine devices (IUDs) are small, T-shaped plastic objects inserted into the uterus by a medical professional to prevent pregnancy. Exactly how IUDs work is a matter of controversy. Originally, it was thought that they worked by speeding the transport of the egg through the fallopian tube, and reducing chances for fertilization. It was also thought that the
IUD produced a mild inflammation in the lining of the uterus, which prevented a fertilized egg from implanting. Today, some investigators insist that neither of these theories is correct and suggest that IUDs work by interfering with the transport of both sperm and egg. IUDs come in a variety of shapes and sizes. Some contain progesterone, while others contain copper. Some combined pills and POPs may be taken in high doses to prevent pregnancy after a birth control failure (such as a condom breaking) or after unprotected intercourse. Hormonal emergency contraception is also known as the morning-after pill, although it is licensed for use up to three days after intercourse. Copper intrauterine devices may also be used as emergency contraception. For this use, they must be inserted within five days of the birth control failure or unprotected intercourse. Sterilization (vasectomy or tubal ligation) is a surgical procedure that provides a permanent means of birth control. Tubal ligation is a surgical procedure for a woman that cuts or bands the fallopian tubes so that sperm cannot reach an egg released by the ovaries, nor can the egg reach the uterus. A vasectomy is a surgical procedure for a man that ties off the spermatic tubes so that the ejaculate becomes sperm-free. Fertility awareness (FA) methods involve a woman’s observation and charting of one or more of her body’s primary fertility signs to determine the fertile and infertile phases of her cycle. Unprotected sex is restricted to the least fertile period. During the most fertile period, barrier methods may be used or she may abstain from intercourse. Different methods track one or more of the three primary fertility signs: basal body temperature, cervical mucus, and cervical position. Other bodily cues including abdominal pain at the time of ovulation are considered secondary indicators. A woman may chart these events on paper or with software. The term natural family planning (NFP) is sometimes used to refer to any use of FA methods. However, this term specifically refers to the practices that are permitted by the Roman Catholic Church, breastfeeding infertility, and periodic abstinence during fertile times. FA methods may be used by NFP users to identify these fertile times. Effectiveness Effectiveness is measured by how many women become pregnant using a particular birth control meth-
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od in a year. The most effective methods in typical use are those that do not depend upon regular user action. Surgical sterilization, Depo-Provera, implants, and IUDs all have failure rates of less than 1 percent per year for perfect use. Depo-Provera, or the shot, has a typical failure rate of 3 percent, while sterilization, implants, and IUDs still have a typical failure use under 1 percent. Other methods may be highly effective if used consistently and correctly, but can have typical use failure rates that are considerably higher due to incorrect or ineffective usage by the user. Hormonal contraceptives, fertility awareness methods, and ecological breastfeeding, if used strictly, have failure rates of less than 1 percent per year. Typical use failure rates of hormonal contraceptives are as high as 8 percent per year. Fertility awareness methods as a whole have typical-use failure rates as high as 25 percent per year; however, as stated above, perfect use of these methods reduces the failure rate to less than 1 percent. Condoms and cervical barriers such as the diaphragm have similar typical-use failure rates (15 and 16 percent, respectively), but perfect usage of the condom is more effective (2 percent failure versus 6 percent) and condoms have the additional feature of helping to prevent the spread of sexually transmitted diseases such as HIV. The withdrawal method, if used consistently and correctly, has a failure rate of 4 percent. Due to the difficulty of consistently using withdrawal correctly, it has a typical use failure rate of 27 percent and is not recommended by some medical professionals, although others believe it deserves more support. Not all methods of birth control offer protection against sexually transmitted infections. Abstinence from all forms of sexual behavior will protect against the sexual transmission of these infections. The male latex condom offers some protection against some of these diseases with correct and consistent use, as does the female condom, although the latter has only been approved for vaginal sex. The female condom may offer greater protection against sexually transmitted infections; however, the female condom can be difficult to use. Frequently, a woman can improperly insert it, even if she believes she is using it correctly. The remaining methods of birth control do not offer significant protection against the sexual transmission of these diseases. However, so-called sexually transmitted infections may also be transmitted nonsexually, and therefore,
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abstinence from sexual behavior does not guarantee 100-percent protection against sexually transmitted infections. For example, HIV may be transmitted through contaminated needles that may be used in tattooing, body piercing, or injections. Healthcare workers have acquired HIV through occupational exposure to accidental injuries with needles. Birth Control Education Many teenagers, most commonly in developed countries, receive some form of sex education in school. What information should be provided in such programs is hotly contested, especially in the United States and Great Britain. Possible topics include reproductive anatomy, human sexual behavior, information on sexually transmitted diseases (STDs), social aspects of sexual interaction, negotiating skills intended to help teens follow through with a decision to remain abstinent or to use birth control during sex, and information on birth control methods. One type of sex education program, called abstinence-only education, promotes abstinence until marriage and does not provide information on birth control, or heavily emphasizes negative information such as failure rates. Because abstinence offers better protection against pregnancy and disease than sexual activity with even the best birth control methods, advocates of abstinence-only education believe they will result in decreased rates of teenage pregnancy and STD infection. However, some studies have found that abstinence-only sex education programs actually increase the rates of pregnancy and STDs in the teenage population. SEE ALSO: Abortion; American College of Obstetricians
and Gynecologists (ACOG); Birth Rate; Obstetrician/Gynecologist; Pregnancy; Sexually Transmitted Diseases; Teenage Pregnancy; Vaginal Diseases; Women’s Health (General). BIBLIOGRAPHY. A. DiCenso, et al., “Interventions to Re-
duce Unintended Pregnancies among Adolescents: Systematic Review of Randomised Controlled Trials,” British Medical Journal (v.324/7351, 2002); “Evolution and Revolution: The Past, Present, and Future of Contraception,” Contraception Online (v.10/6, 2000); John Kippley and Sheila Kippley, The Art of Natural Family Planning, 4th ed. (The Couple to Couple League, 1996); Planned Parenthood, “A
History of Birth Control Methods,” www.plannedparenthood.org (cited September 2006); John M. Riddle, Eve’s Herbs: A History of Contraception and Abortion in the West (Harvard University Press, 1990); S.O. Skouby, “Contraceptive Use and Behavior in the 21st Century: A Comprehensive Study across Five European Countries,” The European Journal of Contraception and Reproductive Health Care (v.9/2, 2004); Patricia Thomas, “Contraceptives,” Medical World News (v.29/5, 1988); James Trussell, et al., “Contraceptive Effectiveness Rates,” in Contraceptive Technology, 18th ed. (Ardent Media, 2007). Barkha Gurbani UCLA School Of Medicine
Birth Defects After being in the womb for months and in the birth canal for hours, most newborns show effects that may be frightening to new parents, even raising the fear of birth defects. Heads may be misshapen, and one or both ears may be folded over or sticking out. Skin may be red, showing signs of forceps use, or yellow, indicating jaundice. In most cases, neither condition is serious. Babies may be placed under lights to correct jaundice, and redness clears up on its own. Thirty percent of all newborns have facial acne, and many have drooling rash. Half of all infants have erythema toxicin, a rash that looks like insect bites. It normally disappears within a month. Eyelids and breasts may be swollen. In some infants tear ducts are blocked, but in 90 percent of cases, the condition clears up without treatment by the end of the first year. In healthy newborns, the body soon takes on a normal appearance. In babies born with birth defects, abnormalities do not disappear, even though they may not be evident for some time, as in the case of autism spectrum disorders (ASD) or Huntington’s disease. Birth defects are the leading cause of infant death. Defects may be structural, functional, metabolic, behavioral, or hereditary, manifesting as physical or mental abnormalities, or both. The most widely used classification of birth defects is the International Classification of Diseases. Teratology is the branch of science that conducts research on the causes, mechanisms, and patterns of abnormal fetal development.
Approximately eight million babies around the world are born each year with some kind of genetic birth defect. Low-weight babies, even if they are fullterm, are particularly vulnerable to a number of defects. A 2006 report by the March of Dimes Foundation contends that in 70 percent of all cases, birth defects could have been prevented or mitigated. Underlying causes associated with genetic birth defects in developing countries include high incidences of babies born to older women, inbreeding, and poor nutrition. Without treatment, around 3.3 million children die from birth defects before the age of 5, and another 3.2 million live with chronic disabilities. In a number of cases, birth defects are associated with an increased risk of sudden infant death syndrome (SIDS). More than 94 percent of all birth defect–related deaths occur in middle and lower income countries. The highest rate of genetic birth defects is found in the Sudan (82 per 1,000 live births) and the lowest rate in France (39.7). The United States falls between those extremes at 47.8. The most common causes of genetic birth defects in the March of Dimes study were congenital rubella, congenital syphilis, iodine deficiency, and fetal alcohol syndrome. Many birth defects are congenital rather than genetic, occurring during fetal development. The five most common causes of congenital birth defects, comprising more than a fourth of the total, include congenital heart defects, neural tube defects, thalassemia and sickle cell disease, Down syndrome, and enzyme disorders. Infants born to two parents from countries that lie in the “malaria belt” are at particular risk for developing thalassemia and sickle cell disease. An enzyme disorder, Tay-Sachs is a recessive, single-gene disorder that involves the inability to break down fatty deposits in brain and nerve cells. It is most common in Jews of eastern European descent. The disorder may not be evident for the first six months of life. Symptoms include behavior changes, paralyses, and blindness. Without treatment, death usually occurs between the ages of 3 and 4. Prevention and screening A number of factors have been identified as deterrents to the development of birth defects, including ingestion of folic aid by women who may become pregnant, diets adequate in iodine, immunizations, proper nutrition, and genetic testing to identify possible risk factors. In 50 to 60 percent of all cases, the causes of
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birth defects are unknown. There is strong evidence that risks for birthing babies with defects increases with the age. One of the most important things that women who are trying to get pregnant can do is to take multivitamins containing folic acid and eat grain products enriched with this essential B vitamin. It is estimated that these efforts could reduce incidences of spina bifida by 70 percent. After Chile added folic acid to enriched flour in 2000, the incidence of neural tube defects declined by 40 percent. Advances in genetic testing allow the potential for certain disorders to be determined before birth. Some parents choose to terminate pregnancies, but others use the knowledge to make plans for meeting the needs of special children. Newborn screening is mandated in all states within the United States and in most countries so that potential problems can be identified and treated as quickly as possible. At a cost of just a few dollars for each test, lives are saved, quality of life is improved, and overall health costs are reduced. In developing countries, many women give birth outside the presence of trained personnel, and infants may not be tested. In countries where populations are susceptible to specific conditions, genetic testing is a major factor in decreasing incidences of birth defects. For instance, in 2001, Iran began testing engaged couples for the thalassemia gene to identify whether one or both partners carried the gene. Identification and counseling of carriers precipitated a 70-percent drop in the number of children born with the disorder. The most common genetic test conducted on newborns is for phenylketonuria (PKU), which leads to severe and irreversible mental retardation if not treated promptly. PKU occurs in one per 10,000 to 15,000 live births. By following specific dietary restrictions, most children with PKU develop normal intelligence. Some American states and a number of countries also test for galactosemia, which develops after a milk feeding and is characterized by diarrhea, vomiting, failure to thrive, and the presence of E. coli and septicemia. The prevalence is one in 60,000 to 80,000 live births. Because continued exposure to milk products may lead to liver disease, jaundice, cirrhosis, cataracts, irreversible mental retardation, or death, treatment is concerned with avoidance of galactose. Testing for hyperthyroidism is also common. The prevalence of this disorder is one in every 3,600 to 5,000 live births. If left untreated, the disorder may cause irreversible
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mental retardation, growth failure, deafness, neurological abnormalities, and characteristics of cretinism. With prompt treatment, normal or near normal performance is achieved by four to seven years. In the United States, the most common neural tube defects are spina bifida and anencephaly. Over 95 percent of both disorders are diagnosed during prenatal testing. The latter condition is always fatal because the brain is only partially formed or entirely missing. The most common birth defect in the United States is spina bifida, which may be dealt with through surgery and rehabilitation. The condition occurs when the spinal column fails to close properly during the first month of fetal formation. The position of the spinal opening is indicative of the severity of problems associated with the disorder. The lower the opening, the better the prognosis is for normal activity. Nerve damage tends to cause at least partial paralysis of one or both legs. Ninety percent of individuals born with spina bifida survive into adulthood, and 80 percent have normal intelligence. Three-fourths are involved in sports and recreational activities. Folic acid has decreased incidences of neural tube defects around the world. Chromosomal abnormalities Normal adult cells contain 46 chromosomes. Two of those cells determine biological sex. Females have XX chromosomes, and males have XY. Before fertilization, metosis occurs, a process by which chromosomes in both the egg and sperm are reduced to 23, with each cell containing only one sex chromosome. When this process fails, abnormalities occur. Chromosomal abnormalities are heavily associated with birth defects that may lead to mental and physical disorders and to confusion over biological sex. Just before the onset of puberty, children with abnormal sex chromosomes who have been brought up as females may be given hormones to stimulate the growth of breasts and the uterus. They may also be put on a regimen of estrogen and progesterone to encourage menstruation. Individuals who have Klinefelter’s syndrome possess an increased number of X chromosomes that are nullified by the presence of Y chromosomes. Physically, they may appear to be males, but testes fail to develop. The condition is highly associated with mental retardation. So-called super females, who have extra X chromosomes but no Y chromosomes, appear physically normal. The degree of mental retardation
in these individuals is dependent on the number of extra chromosomes. Children who are born with testicular feminization have testes, but they otherwise develop as females. Incomplete or imperfect development of the female reproductive organs may lead to a number of conditions such as failure to menstruate by the age of 16 (primary amenorrha), severe pelvic pain, a tendency to urinary retention, and infertility. Treatment may include plastic surgery. Asherman’s syndrome, a condition in which the uterine cavity has been obliterated by adhesions, is common in developing countries with high incidences of tuberculosis and schistosomiasis. Mullerian Agenesis occurs when the fullerien ducts fail to develop properly during the first 10 weeks of gestation preventing the formation of the fallopian tubes, uterus, and upper portion of the vagina. The condition is also associated with spinal and renal malformations. Perhaps the best known of all chromosomal defects is Down syndrome. In the United States, some 5,000 children are born each year with the condition. The prevalence is one in 733 live births. The disorder was first identified by British physician John Langdon Down (1828–96) in 1866. French physician Jerome Lejeune (1926–94) later discovered that Down syndrome children had 47 rather than 46 chromosomes in each cell. Subsequent research revealed that an extra partial or complete 21st chromosome is responsible for the characteristics associated with Down syndrome, which include oblique eyes, a flat nasal bridge, poor muscle tone, enlarged tongues, and short necks. Intelligence levels may vary, but most individuals with Down syndrome are able to take an active part in the lives of their families and community. However, physical conditions such as congenital heart disease, gastroesophagal reflux disease, recurrent ear infections, and thyroid disease are common concerns. Physical defects Many birth disorders are correctable or may be mitigated with education and/or rehabilitation. Others, such as hemophilia, require lifelong vigilance to mitigate the dangers inherent in the condition. Hemophilia is a genetic condition in which the blood fails to clot. It is passed from mother to child, mostly to males. Hemophiliacs have to be extremely careful because even small scrapes or scratches can prove fatal.
Infants born with scoliosis are born with one or more malformed vertebrae. Since the 1940s, geneticists have recognized the role that environmental factors play in fetal development. Until that time, it was assumed that fetuses were protected from outside forces. The revelation that birth defects and environmental agents were linked arose in response to high incidences of babies with birth defects born to mothers who had contracted rubella (German measles) or who had taken the European tranquilizer thalidomide. Mothers who develop rubella early in pregnancy have a high chance of giving birth to infants with multiple birth defects that include blindness, deafness, microcephaly (small head size), cerebral palsy, and congenital heart disease. Birth defects caused by rubella are entirely preventable either through maternal immunity or through immunizations. Approximately 5,000 thalidomide babies were born in Europe with deformities that included being born with gills instead of arms and legs and missing internal organs. Infants born to mothers who abuse drugs and alcohol may be born with fetal alcohol syndrome (FAS). These infants tend to be small in size, and the circumference of their heads is also small. They often have joint abnormalities and congenital heart disease and may experience withdrawal symptoms immediately after birth. Mental retardation is generally mild to moderate, but development and behavior problems are common. Children born with Angelman syndrome (also known as “happy puppet syndrome”), which was first identified by Harry Angelman (1915–96) in 1965, have large mouths with protruding tongues, a puppet-like gait, laughing fits, jerky limb movements, flapping hands, and a small skull. They are also mentally retarded. First identified by Eugene Apert (1868–1940) in 1906, infants with Apert syndrome have peaked, pointed heads and webbed fingers and toes. Children who have Bardet-Biedl syndrome, which was identified by Georges Louis Bardet (1885–?) and Arthur Biedl (1869–1933), have high birth weights. Although of short stature, these individuals become obese children. They have abnormally small genitalia, extra fingers and toes, are mentally retarded, and are subject to psychological and neurological disorders. Kidney problems in 35 percent of all children with this disorder prove fatal.
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When an infant is born, his or her feet may turn in, out, upward, or downward. If feet are easily manipulated into a normal position, many doctors take a wait-and-see attitude. Club foot, which is the second most common defect in the United States, is diagnosed when the foot turns both inward and downward. The abnormality ranges from mild and flexible to severe and rigid. It may affect either or both feet. If feet disorders continue, infants may be placed in casts to straighten the feet. In some cases, the child may need braces, corrective shoes, or surgery. Cleft palate and cleft lip occur when the roof of the mouth and the upper lip do not join during fetal development. The severity of the condition varies from a small notch to a large groove, and it may create difficulties for the child that interfere with eating and talking and increase susceptibility to ear infections. Surgery is performed to correct the condition. Congenital hearing loss is present at birth. It may be related to genetic disorders, maternal intrauterine infections, exposure to harmful substances, prematurity, perinatal anoxia (a lack of oxygen during birth), and hyperbilirubinemia (an excess of bilirubin in the blood). Genetic hearing loss may be a consequence of recessive genes, or it may be X-linked. It may present as a single birth defect, or it may occur in conjunction with other defects. Congenital blindness is a major concern in developing countries, and scientists are working to develop corn hybrids that have been fortified with beta carotene to decrease incidences of congenital blindness. Diseases In industrialized nations, medical technologies have decreased fetal and delivery risks related to mother– child transmissions of infectious diseases. They continue to be a major problem in developing countries, however, particularly transmission of the HIV/AIDS virus. Infants born with AIDS may have craniofacial abnormalities, and they tend to experience failure to thrive and increased susceptibility to infections. Three-fourths of all babies with AIDS have some degree of neurological damage. Any untreated sexually transmitted disease (STD) poses a threat to the health of an unborn child. Because a number of diseases have genetic links, newborns may have already developed certain diseases. Alagille syndrome, for instance, is a hereditary
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liver disease that is characterized by jaundice, failure to thrive in the first three months of life, itching, fatty deposits under the surface of the skin, stunting, and developmental delays. Major organs and systems of the body also tend to be affected. Huntington’s disease is an inherited dominant, single-gene genetic disorder that does not manifest itself until adulthood, generally occurring between the ages of 35 and 45. Over time, facial expressions become twisted and the body becomes uncontrollable. Huntington’s patients may develop deep-seated psychological problems that are similar to manic depression or schizophrenia. It is usually fatal, but genetic testing can identify carriers. Cerebral palsy is a group of disorders that interfere with the brain’s ability to coordinate body movements. The condition may be present at birth, or may become apparent soon afterward. Cerebral palsy is characterized by “spastic movement,” involuntary movements, tight muscles, difficulty walking, and difficulty with fine motor skills, sensations, and speech. Seizures are not uncommon. Many people mistakenly assume that all individuals with cerebral palsy are mentally retarded because of physical abnormalities. Cystic fibrosis is the most common fatal genetic disease found among Caucasians. It is caused by a recessive, single-gene disorder that results in malfunctions of the lungs and pancreas. It may not be diagnosed for three or four years. Medical advances with gene and enzyme therapy have allowed patients with cystic fibrosis to lead longer lives than in the past. A type of muscular dystrophy known as Duchenne-type is passed from mothers to sons. The onset is generally between the ages of three and nine, and muscles continue to deteriorate over time. Because the muscles of the heart and lungs are affected, the disease is always fatal. See also: Abortion; AIDS; Autism; Down Syndrome; Fo-
lic Acid; Genetic Disorders; Genetic Testing/Counseling; Hormones; Infant and Toddler Development; Infant and Toddler Health; Obstetrics; Pregnancy; Sexually Transmitted Diseases; Sickle Cell Anemia; Smoking and Pregnancy; Spina Bifida; Sudden Infant Death Syndrome; Tay-Sachs Disease; Vitamin and Mineral Supplements. Bibliography. M.A. Ferguson-Smith, et al., eds., Prena-
tal Diagnosis and Screening (Churchill Livingstone, 1992); George Fried and George J. Hademenos, Schaum’s Outline of Theory and Problems of Biology (McGraw-Hill Profes-
sional, 1999); Gordon B. Hughes and Myles L. Pensak, eds., Clinical Otology (Stuttgart, 1997); Patricia Ludder Jackson and Judith A. Vessey, Primary Care of the Child with a Chronic Condition (Mosby, 2000); March of Dimes, “The March of Dimes Global Report on Birth Defects, The Hidden Toll of Dying and Disabled Children,” www.marchofdimes.com (cited July 2007); Thomas H. Maugh II, “Nearly 8 Million Babies Are Born with Genetic Defects Yearly, Study Finds,” Los Angeles Times (January 31, 2006); David McKay and Jane Norman, Gynaecology Illustrated (Churchill Livingstone, 2000); Keith L. Moore and T.V.N. Persaud, Before We Are Born: Essentials of Embryology and Birth Defects (W.B. Saunders, 1998); National Down Syndrome Society, www.ndss.org (cited July 2007); The Planned Parenthood Women’s Health Encyclopedia (Crown, 1996); Philip R. Reilly, Is It in Your Genes? The Influence of Genes on Common Disorders and Diseases that Affect You and Your Family (Cold Spring Harbor Laboratory Press, 2004); Spina Bifida Association, www.sbaa.org (cited July 2007); Jenifer Swanson, Infant and Toddler Health Source Book: Basic Consumer Health Information (Omnigraphics, 2000); B. Wilcken, et al., “Screening Newborns for Inborn Errors of Metabolism by Tandem Mass Spectrometry,” New England Journal of Medicine (v.348, 2003); James Wynbrandt and Mark D. Ludman, The Encyclopedia of Genetic Disorders and Birth Defects (Facts on File, 2000). Elizabeth R. Purdy, Ph.D. Independent Scholar
Birthmarks Birthmarks are a common finding in children. Typically, birthmarks are different types of noncancerous vascular tissue. Although most of these are apparent at birth, they may become noticeable at different ages. Hemangiomas are collections of vascular cells that are usually raised above the skin. These lesions are typically red, soft, and usually compressible. They range in size from a millimeter to a few centimeters, and less commonly are they larger than five centimeters. They may occur in up to 3 percent of newborns. About 65 percent are superficial, and primarily capillary in nature. The cavernous or deep type represent an additional 15 percent, and the remaining 20 percent of hemangiomas present as a mixed picture with components of
Birth Rate
both superficial and deep growths. Sometimes, deeper lesions appear darker red or bluish in color. There are more hemangiomas in female infants and premature infants, and statistically most hemangiomas found in the first month of life occur on the head and neck, followed by the trunk, and then the extremities. Hemangiomas typically have a period of rapid growth for several months and may grow until the child is approximately one year old. At that time, most hemangiomas have reached their maximum size and their growth rate plateaus. The collection of cells then usually involute over time, occasionally ulcerate, and then shrink and disappear. Seventy-five percent of hemangiomas have resolved by five to six years of age. Although therapies exist to manage hemangiomas, including topical or injected steroids, surgery, laser therapy, chemotherapeutics, radiation, cryotherapy, antifibrinolytics, among others, most regress and completely disappear without treatment within five years. Bleeding and infection may complicate the process; therefore, treatment options must be weighed based on potential scarring or loss of function prior to initiation of therapy, or potential side effects subsequent to treatment. The second major type of birthmark is vascular malformation. These abnormal groupings of blood vessels are usually flat on the skin and do not typically enlarge. The capillary growths range in color from pink to red to purple, and they may involve both superficial and deeper vessels and tissue. Although these birthmarks may fade, they often persist into adulthood. One superficial grouping of dilated capillaries is called a “stork bite” or “salmon patch.” These light red areas commonly found on the nape of the neck occur in 40 percent of all infants. Sometimes during physical exertion or crying, these areas may become more noticeable and erythematous, or a deeper red color. Another type of vascular grouping is known as a “port-wine stain.” This particular vascular abnormality often involves deeper tissue, therefore there also may be associated local bone irregularity and neurologic symptoms related to the abnormality. Sometimes children with this type of birthmark and specific involvement of the ophthalmic branch of the fifth cranial nerve (trigeminal) may also have vascular abnormalities involving brain tissue or the blood vessels feeding the brain. Children with these syndromes may also have associated seizures, mental retardation, hemiplegia, and glaucoma. “Port-
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wine stains” tend to darken over time. Categorically, since vascular malformations are congenital abnormalities, they are more permanent and may persist throughout life. Treatment for these conditions is based upon functional impairment or cosmetic desire, and may involve surgical intervention or flashlamp pumped pulsed dye laser (FPDL). See also: Birth Defects; Skin Diseases (General); Skin
Pigmentation Disorders.
BIBLIOGRAPHY. Fern A. Wirth, M.D., and Mark H. Low-
itt, M.D., “Diagnosis and Treatment of Cutaneous Vascular Lesions,” American Family Physician (v.57/4, 1998); Basil J. Zitelli and Holly W. Davis, Atlas of Pediatric Physical Diagnosis, 4th ed. (Mosby, 2002). Ann M. Karty, M.D., FAAFP Kansas City University of Medicine and Biosciences
Birth Rate Birth rate is a measure that quantifies the number of births in relation to population size. Births, deaths, in- and out-migration are important components of population change. An essential but not inclusive measure of the population change is the birth rate. The crude birth rate (CBR), which is the simplest measure of natality, is usually calculated by dividing the number of live births in a population in a given period (usually one year) by the average or midyear population size multiplied by a constant K (usually 1,000). The numerator is usually obtained from birth registers, which vary in completeness and accuracy from one country to another, whereas the source of the denominator is the census or population estimate. Under reporting of births and deaths is more common in developing countries than in developed countries. An example of calculating crude birth rate: Country X has a population of 1.6 million in the year 2005, and the total number of live births in the same year was 40,000. CBR = (#livebirths/midyear population) x K
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CBR = (40,000/1,600,000) x 1,000 = 25 per 1,000 population in 2005 Natural increase of a population refers to the difference, whether positive (surplus) or negative (deficit), between births and deaths in a population. Natural increase = births – deaths for a specific population in a given time. Measures of fertility include age-specific fertility rate, which is the most suitable statistical measure for detailed comparison between different populations, because it is not affected by different age composition. It is defined as the number of births to women in a given age group divided by the number of women in the same age group multiplied by a constant. General fertility rate (GFR) is the number of live births per 1,000 women of childbearing age (usually 15–49 years); the total fertility rate (TFR) is the average number of children born to a women throughout her reproductive years. TFR is a robust measure of fertility that is not affected by the age structure. Among the factors affecting birth rate are the current age-sex structure, religious beliefs especially concerning contraception, economic status, women’s social status, female literacy levels, and general education. Improving the last four factors usually leads to a decline in birth rates. The issue of anticontraception religious beliefs is very sensitive and should be approached cautiously to avoid undesirable community reactions. However, birth control programs that do not tackle these factors are not effective unless they are enforced by a central government with a strong antinatalist policy. Birth rate is also an important indicator of demographic transition, which starts with a decline in mortality rates and birth rates. However, the mortality decline precedes the fertility decline, leading to a rapid population growth during the transition period. In midyear of 2006, the estimated world birth rate was 21 per 1,000, whereas for the more developed countries it was 11 per 1,000, and for the less developed countries it was 23 per 1,000. SEE ALSO: Birth Control/Contraception; Death Rate. Bibliography. D. Coggon, G. Rose, and D. Barker, Epi-
demiology for the Uninitiated (BMJ, 2003); Leon Gordis, Epidemiology (Saunders, 2004); John Last, A Dictionary of Epidemiology (Oxford University Press, 2000); Popula-
tion Reference Bureau, 2006 World Population Data Sheet (Population Reference Bureau, 2006). Abdullatif Husseini Birzeit University
Bisexual The term bisexual refers to persons of both sexes (female and male) whose orientation, preferences, or sexual practices are based on bisexuality. Bisexuality in human sexual or communicative behavior is related to aesthetic, romantic, or sexual desire for people of either gender/sex. It can also be the search for emotional/sexual satisfaction with both sexes/genders. Sometimes, it is considered a third category together with homosexuality or heterosexuality, but for most experts, bisexuality expresses a blend of the two. Although as a form of sexual behavior it is as old as the other two commonly accepted forms (heterosexuality or homosexuality), and is recorded in reliable history and documents, bisexuality became a serious object of study only recently, beginning approximately in the first decade of the 20th century. Bisexuality does not necessarily imply an equal attraction to both genders/sexes; bisexuals can have their own preferences, they can even feel attracted to a gender and not to a sex. Bisexuality, like other forms of sexual orientation, includes a large variety of sexual lifestyles such as monogamy, group sex, serial monogamy, polygamy, or celibacy. The term bisexual was first used in the 19th century to refer to hermaphrodites. In 1914, it began to be used to refer to a sexual orientation, preference, practice, or feeling. Other terms recently incorporated into the context of “bi” gender attraction, and commonly used as synonyms, are pomosexual, omnisexual, or pansexual. Bisexuality was a common option in several cultures in history, for instance, in the shudo tradition in Japan or the baccha practices of central Asia. There are other cases where homosexuality is a ritual that boys have to follow before experiencing an adult heterosexual life. Among the Sambia of New Guinea, boys are separated from the rest of their people when they are 7 and are sent back once they are 10 after three years of homosexual practice. In this context, the combination
of homosexuality and heterosexuality helps one come of age properly. Early homosexuality was mandatory for the Spartans, for men as well as for women. After developing strong emotional links among members of the same sex, every adult was prepared for assuming the responsibility of procreation. Only some monotheistic religions have privileged heterosexuality, and, therefore, other forms of sexual behavior were suppressed—bisexuality among them. In The Bisexual Option by Dr. Fred Klein, he proposes a classification of bisexuality into three main categories: temporary, historical, and sequential. The category of temporary bisexuality could be applied to individuals who, after a time with bisexual behavior, finally become homosexual or heterosexual, but never both. Historical bisexuality refers to individuals who have a clear heterosexual or homosexual orientation, but who sometimes experience sexual fantasies with people of the opposite gender or sex. Sequential bisexuality concerns individuals who have, in a successive way, a relationship with a male and with a female. Some other classical studies about sexual behavior, notably Alfred Kinsey’s Sexual Behavior in the Human Male (1948) and Sexual Behavior in the Human Female (1953), have hyptothesized that all people seem to be at least somewhat bisexual. Those studies show that most people have some kind of attraction to each sex, although in practice, only one of the sexes is preferred. In fact, only between 5 and 15 percent of the entire (interviewed) population were strictly homosexual or heterosexual. Because of the stigma of bisexuality, like other sexual options beyond the accepted heterosexual rule, even in homosexual communities bisexuals are accused of duplicity. It is a common stereotype and it is usually believed that bisexuals are really hidden homosexuals who engage with heterosexual relationships in order to be socially accepted. For that reason, bisexuals are often associated with the image of homosexual men who are married to women or at least have an open and visible heterosexual relationship. This is, in fact, the main point of the ambiguity in the interpretation of bisexuality: There is always an (apparent) distance between the real behavior and the declared or explicit orientation. SEE ALSO: Homosexual; Lesbian.
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Bibliography. William E. Burleson, Bi America: Myths,
Truths, and Struggles of An Invisible Community (Haworth Press, 2005; Alfred Kinsey, ed., Sexual Behavior in the Human Female (Indiana University Press, 1998 [1953]); Alfred Kinsey, Wardell B. Pomeroy, and Clyde E. Martin, Sexual Behavior in the Human Male (Indiana University Press, 1998 [1948]); Fred Klein, The Bisexual Option, 2nd ed. (Haworth Press, 1993). Natalia Fernandez Diaz Independent Scholar
Blackwell, Elizabeth (1821–1910) Elizabeth Blackwell was a pioneer in the field of preventative medicine and the first woman in America to receive a medical degree. She was born into a large and privileged family in Bristol, England, on February 3, 1821. Her father, Samuel, was a sugar refiner. In 1832, after his business failed, the family emigrated to the United States, where they became active in the abolition movement and other unpopular causes. Blackwell’s father died shortly after the family moved to Cincinnati in 1837, and she became a teacher to help keep the family financially afloat. In 1845, she visited a friend named Mary Donaldson, who was dying of cancer. During their conversation, Donaldson commented, “If I could have been treated by a lady doctor, my worst sufferings would have been spared me.” Then she said, “You are fond of study, Elizabeth. You have health, leisure, and a cultivated intelligence. Why don’t you devote these qualities to the service of suffering women? Why don’t you study medicine?” Blackwell tried to reject Donaldson’s suggestion. She was not fond of science nor was she particularly interested in healing the sick. However, she slowly warmed to the idea of a challenge, and within months, she was reading medical books and trying to gain admission to medical schools. She was rejected by 29 schools before receiving a reply from tiny Geneva Medical College in upstate New York. The professors had put her application before the student body, who had voted for her admission either as a joke or to annoy the faculty, who clearly did not want her there.
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When she arrived in Geneva in November 1847, the wives of the faculty would not even look at her, considering her “either wicked or insane.” Through hard work and determination, she graduated near the top of her class on January 29, 1849. As college president Benjamin Hale handed her the degree, she said, “Sir, by the help of the Most High, it shall be the effort of my life to shed honor on this diploma.” She spent the next few years in France and England, trying without tremendous success to gain admittance into the medical community. While she was away, her sister Emily had also decided to become a doctor, and in 1857, the two opened the first women’s hospital, the New York Infirmary for Indigent Women and Children. In 1868, she opened the first women’s Medical College on the infirmary grounds. The next year, considering her pioneering work in America complete, she left for England. In England, Blackwell helped organize the National Health Society and was a cofounder of the London School of Medicine for Women, where she taught for many years as a professor of gynecology. She was the first woman listed in the British Medical Register. She also became a well-known writer and lecturer on preventative medicine and women’s rights. Blackwell settled in a village near the English Channel, where she died on May 31, 1910, at the age of 89. By that date, there were 7,399 female doctors and surgeons in the United States. See also: Hygiene; Preventive Care; Women’s Health
(General).
Bibliography. “Elizabeth Blackwell, MD, the First Fe-
male Medical Doctor Educated at Geneva Medical School,” campus.hws.edu/his/blackwell (cited February 2007); Dean Smith, “A Persistent Rebel,” American History Illustrated (January 1981). Heather K. Michon Independent Scholar
Bladder Cancer The bladder is an organ that receives and stores urine from the kidneys. When a tissue within the bladder
becomes cancerous, it is called bladder cancer. According to the National Cancer Institute, over 65,000 new cases of bladder cancer will be diagnosed in the United States in the year 2007. Only about one-fifth of that number will die from bladder cancer in the same year. Bladder cancer is the fourth leading cancer affecting males in the United States. According to the Mayo Clinic, males are four times more likely to develop bladder cancer than women. There are three major types of bladder cancer, each affecting one of the three major cell types in the bladder. The first type is transitional cell carcinoma. Transitional cells line the bladder. They are called transitional cells because they are the transitional shape between thicker cells and flat squamous cells. A second common bladder cancer is that of the squamous cells. The third major bladder cancer is an adenocarcinoma. The affected cells are mucous- and fluid-secreting cells. When a certain cell population is continuously under stress, such as hostile conditions or a need for regeneration and repair, that population is at a higher risk for developing cancer, because cancer is an inability of cells to control their rate of growth. If a person has consistent inflammation or other irritation in his or her bladder, that person is at an elevated risk for developing squamous cell cancer or an adenocarcinoma. Adenocarcinomas may also occur in people with specific rare birth defects affecting their bladders. An additional risk for squamous cell cancer is an infection. As with many other cancers, a risk factor for bladder cancer is smoking. In fact, smoking is the greatest risk factor for bladder cancer. Additionally, occupational chemical exposure, such as to certain textile chemicals and those involved in production of hair products, paint, and rubber, may increase a person’s risk for developing bladder cancer. Other risk factors include male gender, older age, or being white. According to the Mayo Clinic, more than 90 percent of bladder cases in the United States develop in people greater than 55 years of age. Furthermore, white people are twice as likely to develop bladder cancer as black or Hispanic people. The population with the lowest risk of bladder cancer is Asians. Nutritionally, eating a high-fat diet or consuming excessive amounts of fried meats may leave a person at a higher risk for developing bladder cancer. A study published in 1999 by researchers at Harvard University shows that bladder cancer risk in men may
be reduced by a diet high in cruciferous vegetable such as cauliflower. Other cruciferous vegetables include kale, broccoli, bok choy, turnips, radishes, and horseradishes. An additional study from the same researchers, also published in 1999, shows that higher fluid intake reduces the risk of bladder cancer in men. While the research on cruciferous vegetables has not been related to women, it is generally accepted that a high fluid intake and therefore dilution of toxins and regular flushing of these toxins can help anyone lower his or her risk of developing bladder cancer. Drinking water with high levels of arsenic can also increase a person’s risk for bladder cancer. Another risk factor for developing bladder cancer is receiving radiation therapy for other cancer. Females undergoing radiation therapy for cervical cancer are more likely to develop bladder cancer than other women. Males receiving radiation therapy for prostate cancer do not have an elevated risk for bladder cancer. All patients taking the anticancer medications cyclophosphamide (Cytoxan) or ifosfamide (Ifex) have an elevated risk of bladder cancer. To screen for bladder cancer, there are many options, both invasive and external. A simple test is screening the urine for red and white blood cells, which should otherwise not be present. The urine can also be viewed with a microscope to look for the presence of any unhealthy cells. Traditional imaging methods such as X-ray or computed tomography (CT) scan may also be used to examine the anatomy for proper size and function, and find any blockages due to tumors. A minimally invasive screening procedure is a digital exam, whereby the physician feels for bumps with his or her fingers, via the vagina or rectum. An additional option is the use of a cytoscope, or a narrow flexible tube that has a light and a lens on one end and which is inserted into the patient to examine internally. Questionable tissue may be sampled for a biopsy or a detailed examination by a pathologist for abnormalities. Often biopsy samples can be taken during cytoscopy. Additionally, the tumors are often small enough to be removed completely via the biopsy process. There are many treatment options for bladder cancer. These options include chemotherapy, radiation therapy, and surgery, as well as immunotherapy and vaccine therapy. Treatments are designed around the patient’s age, general health, and the stage of the bladder cancer. An invaluable method for evaluating the
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efficacy of a novel technology or drug for treatment, diagnosis, prevention, or cure of cancer is the clinical trial. Eligible patients of bladder cancer are encouraged by the National Cancer Institute to participate in a relevant clinical trial. To determine eligibility, potential patients are screened thoroughly, and counseled extensively to assist their decision based on the risks of participation and the possible benefits. As with many other cancers, the earlier a patient is diagnosed with bladder cancer, the better his or her prognosis will be. Bladder cancer can spread to other surrounding tissues. Once this happens, treatment is difficult; however, if the cancer has not yet spread, the chance for a successful treatment is higher. SEE ALSO: American Association for Cancer Research
(AACR); American Cancer Society (ACS); American Urological Association (AUA); Bladder Diseases; National Cancer Institute (NCI); Nutrition; Occupational Health; Pathology; Smoking; Urinary Tract Infections; Urological Surgeon; Urologist; Viral Infections. Bibliography. Michael Bailey and Michael Sarosdy,
Bladder Cancer (Fast Fact Series) (Health Press, 2006); Gary N. Dunetz, Bladder Cancer: A Resource Guide for Patients and Their Families (AuthorHouse, 2006); Pamela Ellsworth and Brett Carswell, 100 Questions & Answers about Bladder Cancer (Jones and Bartlett, 2005); D.S. Michaud, et al., “Fruit and Vegetable Intake and Incidence of Bladder Cancer in a Male Prospective Cohort,” Journal of the National Cancer Institute (v.91/7, 1999); D.S. Michaud, et al., “Fluid Intake and The Risk of Bladder Cancer in Men,” New England Journal of Medicine (v.340/18 1999); Mark P. Schoenberg, The Guide to Living with Bladder Cancer (Johns Hopkins University Press, 2000). Claudia Winograd University of Illinois at Urbana-Champaign
Bladder Diseases The bladder, the storage organ of the urinary tract system, is a triangular shaped organ in the abdomen to hold urine prior to elimination. The urinary tract system starts in the kidneys where blood is filtered and urine is produced. Normal urine holds water,
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salts and wastes no bacteria, viruses or fungi. The bladder has defense mechanisms against colonization by pathogens, emptying of the bladder to decrease colony counts, a protective layer of glycosaminoglycan to prevent bacteria from adhering to the bladder wall and the urine’s antimicrobial properties. The urine passes through tubes called ureters to fill the bladder. With normal voluntary control, the urine empties from the bladder into the urethra to pass out of the body. The bladder has elastic walls to allow the bladder to fill and with normal bladder function the pressure inside the bladder is greater than the sphincter resistance and the urine empties through the urethra. The bladder drains completely and contracts when it has been emptied. The bladder holds approximately 1 1/2 cups or 350–500 mL of fluid and the average adult produces approximately 1 1/2 quarts per day. Normal adults void four to six times per day. Bladder contraction is coordinated with urethral sphincter relaxation. The central nervous system inhibits or facilitates voiding and controls the smooth muscle with the sympathetic α-adrenergic system. The parasympathetic nerves (cholinergic) contract the detrusor muscle in the bladder to allow the bladder to empty. The somatic nervous system controls the striated muscle sphincter. Urinary Symptoms with Bladder Involvement Patient symptoms with bladder involvement include urgency (sudden need to urinate), frequency (need to urinate more frequently during the day with no increase in volume), nocturia (need to get up more than once in the night to urinate), oliguria (less-thannormal urine elimination) hesitancy (delay while bladder pressure increases to overcome sphincter resistance, straining, decreased force of urination, dribbling and dysuria (painful urination often associated with inflammation). These symptoms might be caused by increased urine output or decreased bladder capacity. The cause of increased urine output will be determined and can be secondary to other disease states like diabetes, excess fluid intake and the use of diuretics. The cause of decreased bladder capacity might be due to obstruction at the bladder neck or distally in the urethra like benign prostatic hyperplasia, of a neurogenic nature causing the bladder to
have limited expansion and contraction capability or from bladder compression by conditions like tumors, pelvic mass, and pregnancy. Diagnostic Tools used for Bladder Diseases In addition to the history and physical examination, the physician or urologist (specialist in urinary tract health) will perform diagnostic testing to rule out, differentiate and confirm diagnosis of bladder disease. Urinalysis can provide information indicative of various diseases not just those limited to the urinary tract. In the physician's office, the urine dipstick test will provide clues to urinary tract disease like information on the pH of the urine (possible sign of bacterial infection), detect the presence of nitrites (possible sign of bacterial infection), and detect the presence of blood. The presence of blood in urine (hematuria) indicates need for immediate and thorough evaluation, while hematuria may be a signal to test further for cancer, it is not necessarily indicative of cancer. Hematuria may be caused by infection, prostatitis, overexertion, urinary stones, and lesions. Additional testing will pinpoint the cause. Microscopic urinalysis can determine presence and identification of pathogens causing infections confirm the shape of crystal and stone formation and confirm the presence of numerous other cells indicative of diseases in other parts of the urinary system or other body systems. Cytoscopy provides a visual of the bladder and lower urinary tract. A small tube is inserted into the bladder with light and telescope for the physician to check for abnormalities. Abnormal tissue can also be taken for biopsy to determine if it is cancerous. Imagine, X-ray, ultrasound, or magnetic resonance imaging (MRI) are useful in detecting tumors, checking for residual urine, observing bladder function, bladder wall contours and bladder position. Cystometry is used to test bladder capacity and control by filling the bladder with water or air and recording intravesical pressure and sensations. Congenital Anomalies of the Bladder These diseases are often diagnosed before birth by sonogram and at birth a special team can evaluate the infant’s health and plan for treatment.
Bladder exstrophy. Infants born with an open bladder at the top causing urine to leak from ureteral orifices, corrected by bladder reconstruction or urinary diversion if the bladder cannot expand properly. Congenital bladder diverticula. Development of pouches in the bladder wall predispose the person to urinary tract infections. Diagnosis can be made by cytoscopy and removal of diverticula may be necessary. Megacystis syndrome. Large thin-walled smooth bladder without outlet obstruction. Obstructive uropathy is hindered urine flow due to a possible bladder neck obstruction. Treatment is by catheterization. Bladder Diseases and Treatment Options Urinary Tract Infection. Acute cystitis is a urinary tract infection of the bladder with common causes of coliform bacteria or gram-positive bacteria; sometimes in children the infection will be viral from adenovirus. Symptoms include frequency, urgency and dysuria. The urinalysis is positive for the pathogen. Infections can vary from uncomplicated to recurrence, infection with new pathogens and spread to other areas of the urinary tract. Treatment with antibiotics to which the infecting organism is susceptible is effective. Trimethoprim-sulfamethoxazole taken orally can be used for the acute cystitis and for prophylactic care in women with frequent cystitis. Other medications used to treat cystitis include cephalexin, ciprofloxacin, nitrofurantoin, norfloxacin, and ofloxacin. Infection typically responds rapidly to antibiotic therapy. Urinary Incontinence. Urinary incontinence is an involuntary leakage of urine and is most common in the older population. Remaining continent requires the bladder to expand and contract and for the sphincter to be under voluntary control. Incontinence is caused by a variety of circumstances exstrophy, bladder dysfunction, congenital or acquired neurogenic bladder, bladder outlet obstruction, flaccid bladder resulting in overflow incontinence where the pressure inside the bladder exceeds outlet resistance. Detrusor muscle overactivity interferes with bladder control (the bladder involuntarily contracts), the bladder contraction may be weak and excess urine stays within the bladder (urine retention). Detrusor muscle underactivity may result from an injury to the nerves or caused by anticholinergic drugs. In addition to the physical and correctible bladder in-
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sufficiencies, other factors play a role in incontinence including mobility to make it to the bathroom in time, mental awareness to recognize need to urinate and where to do so. Urinary incontinence can be classified in four categories, total incontinence (any time, any position), stress incontinence (with activities that increase pressure inside the abdomen, laughing, sneezing, or exercising), urge incontinence (unexpected urgency with uncontrolled urine release most often with inflammation or neurogenic disorder) and overflow incontinence (chronic internal bladder pressure minimally exceeds resistance causing dribbling). Patients can assist physicians with diagnosis by providing a good history of incontinence, keeping a diary or journal over a two- to three-day span to record volume and time of urination, any episodes of incontinence and related observations or assessments. Physical, laboratory and testing with cystometry will determine bladder capacity and function to reveal the cause of incontinence. Treatment options vary by diagnosis/severity and may include noninvasive techniques as strengthening the pelvic muscles with Kegel exercises and scheduling voiding times, medication with anticholinergics or estrogen cream as appropriate for women, intermittent catheterization, sacral nerve stimulation with TENS (transcutaneous electrical nerve stimulation) or surgical correction Neurogenic Bladder. Vesical dysfunction by nerve supply with two types hypotonic (flaccid) or spastic (contracted) bladder. Injury or damage to the brain or spinal cord, peripheral nerve damage, acute infectious diseases, chronic vascular disease and metabolic disorders all can interrupt the innervation of the bladder. Injury or damage to the local nerve supply in the sacral spinal cord most often leads to the hypotonic type of neurogenic bladder and injury or damage to the brain or suprasacral spinal cord most often leads to spastic type of neurogenic bladder. In the hypotonic type symptoms experienced include distension of the bladder and constant dribbling. The patient may experience very little pain and have frequent urinary tract infections. Treatment by catheterization can prevent overdistension. In the spastic type symptoms are characterized by urge incontinence, treatment by surgery to maximize emptying while minimizing outlet resistance.
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Recovery is uncommon. Medication therapy may improve bladder storage by relaxing the smooth muscle in the bladder wall, emptying by stimulating the contraction of the detrusor muscle in the bladder and control. The patient should be monitored for renal function and complications. Interstitial Cystitis. Interstitial cystitis is an inflamed, irritated bladder wall even with the layer of glycocalyx to protect the bladder from toxic effects of urine. Common symptoms are pain with bladder filling that is relieved on voiding, urgency and frequency, decreased bladder capacity, pressure, pain or tenderness and painful sexual intercourse and in men discomfort in the penis and scrotum. In women, the symptoms are more severe or related to menses. The cause of the disease is unknown and often accompanies other diseases like allergies, irritable bowel syndrome and inflammatory bowel disease. Interstitial cystitis appears in two forms the non-ulcerative form with inflammation and irritation is more common in young women and the ulcerative form with the development of ulcers leading to scar tissue fibroids is more common in middle-age and older women. The bladder capacity is diminished by fibrosis formation making the bladder stiff and small. Diagnosis is made by exclusion of other diseases; because of similar symptoms to other disorders, other conditions must be ruled out first. Oddly enough, one diagnostic tool is also a treatment: the cystoscopy with distension of bladder has been shown to cause symptoms to subside perhaps because of increased bladder capacity. Other treatments include bladder instillation (washing and bathing the inside of the bladder) with dimethyl sulfoxide, heparin, or BCG to relieve symptoms. Complementary therapies of acupuncture and TENS (transcutaneous electrical nerve stimulation) provide symptom relief. Medications may restore the bladder lining. Surgery is considered only when all other options fail. Bladder Cancer. Malignant tumors develop on lining of the bladder wall and spread to underlying muscle and throughout the body in venous and lymph pathways. Symptoms include blood in urine, pain, urgent need to urinate related to the storage and emptying of urine. Bladder cancers detected by imaging must be confirmed with cytoscopy and biopsy. Primary bladder cancers are epithelial malignancies, most commonly transitional cell carcinoma with
papillary growths or ulcerated lesions. Adenocarcinomas and squamous cell cancers are associated with vesical calculi and chronic catheter use. Superficial cancers can be treated with transurethral resection and intravesical chemotherapy with thiotepa, mitomycin, and doxorubicin. The most effective agent for intravesical installation is BCG (attenuated tubercle bacilli) acts as a nonspecific immunostimulant activating macrophages to effective killer cells for prolonged and disease-free intervals. More invasive localized cancers require partial cystectomy (removal of lesions or in the bladder diverticulum) or radical cystectomy (removal of bladder, prostate, seminal vesicles, fat and peritoneal attachments in men and removal of bladder, uterus, cervix, urethra, anterior vaginal vault, fat, peritoneal attachments and often ovaries) along with treating with radiotherapy and chemotherapy Bladder Disease Secondary to Other Diseases Benign Prostate Hyperplasia (BPH). The increased cell production in the prostate causes it to enlarge and obstruct urine flow resulting in higher outlet resistance, hypertrophy of detrusor muscle, diverticula, and a predisposition to infection. Porphyria causes increased levels of porphyrins and precursors excreted in urine. The bladder may be affected including urinary retention, dysuria, and frequency. Information for Patients In addition to physicians and nurses many organizations create, maintain and disseminate information for patients and family to understand health conditions from bladder diseases. As a place to start, the National Institute of Health at www.nih.gov provides a searchable site to type in the diagnosis, organ affected or keywords and provides links to numerous organizations. SEE ALSO: American Urological Association (AUA); Can-
cer (General); Incontinence; Urinary Tract Infections.
Bibliography. “Bladder Diseases,” National Institute
of Health, www.nlm.nih.gov/medlineplus (cited August 2007); Sydney E. Salmon and Alan C. Sartorelli, “Cancer Chemotherapy,” Basic and Clinical Pharmacology (Ap-
Bleeding Disorders
pleton and Lange, 1998); Linda M. Ross, ed., Kidney and Urinary Tract Disease and Disorders Sourcebook (Omnigraphics Inc, 1997); Marshall L. Stoller and Peter R. Carroll in “Urology” Current Medical Diagnosis & Treatment 2004 (Lange, 2004). Lyn Michaud Independent Scholar
Bleeding Disorders Bleeding disorders are a broad group of diseases that can be categorized under multiple different causes and clinical presentations. There are several different types of bleeding disorders that have several different etiologies. Most bleeding disorders are caused by defects in the body’s normal blood clotting capability. Common causes of bleeding disorders are due to problems with normal functioning of platelets, clotting factors, blood vessels, and tissue integrity. Disorders involving certain aspects of the normal clot formation process can be due to an inherent disease process or genetic defect, they can be caused by adverse effects of certain medications, or they can be caused secondarily to other disease states. All these disorders share in common that an individual with this bleeding disorder will have an increased propensity to bleed as well as the inability to stop the bleeding and maintain normal homeostasis functioning. Homeostasis is the body’s capacity to maintain normal blood flow to essential organs and body parts through a series of blood vessels (i.e., arteries, capillaries, and veins) and supporting tissues. Homeostasis functions to maintain sufficient tissue perfusion by preventing excess formations of thromboses (clots inside blood vessels) as well as breaking up existing clots when required (disorders of this aspect of homeostasis are not going to be addressed in this entry, see Hypercoagulable Disorders). The body’s homeostasis must also function to prevent the loss of blood by the ability to form clots when necessary. Defects in this component of homeostasis are the source of most bleeding disorders and will be addressed in this entry. In cases of tissue damage in humans, the normal response of the body is to form clots to stop bleeding and initiate tissue repair. Blood clots are formed
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by the interaction of certain components of tissues, platelets, blood clotting factors and other blood signaling molecules. These compounds undergo various complex chemical interactions, thereby allowing the body to precisely regulate the extent of clotting at the exact site of injury. It is likely there will be some form of a bleeding disorder if the body has a defect in the functioning of the normal clotting system. platelet disorders One of the most common defects in clot formation is disorders of platelets. Defects can be due to decreased formation of platelets, increased destruction or consumption of platelets, or impairment in normal function of platelets. There are normally 150,000 to 450,000 platelets per cubic millimeter of blood and are made from cells called megakaryocytes in the bone marrow; decrease in number of platelets is called thrombocytopenia. Clinical features of thrombocytopenia are increase amount of bleeding, easy bruising, formation of petechia and purpura (skin rashes), prolonged bleeding time (time before bleeding stops after injury), and possible (potentially life-threatening) intracranial or gastrointestinal bleeding. Thrombocytopenia is usually due to the decreased formation or increase destruction of platelets. Decreased formation of platelets can be due to (but not limited to) vitamin B12/folate deficiency, severe blood infections (sepsis), and certain leukemias. These diseases cause decrease in number or decrease in functioning of normal megakaryocytes in bone marrow, leading to decreased platelets. B12 and folate are required for normal proliferation of megakaryocytes and other blood cells in bone marrow, deficiency in these essential vitamins lead to thrombocytopenia and anemia. Severe infections of the blood cause inflammation, which decreases proliferation of megakaryocytes and decreases number of platelets. Leukemias, especially, can lead to severe platelet deficiency due to overgrowth of cells other than megakaryocytes within the bone marrow. One severe side effect in patients with leukemia is their increased propensity to bleed due to lack of platelets in the blood. Platelets usually live for about nine days in the blood; anything that causes platelets to have a shorter lifespan can cause bleeding disorders. There are some primary (inborn) disorders that cause thrombocytopenia by increasing destruction of platelets.
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Thrombotic thrombocytopenic purpura (TTP) is a disorder caused by a deficient enzyme in blood vessels that regulates and shuts off clot formation. TTP is characterized by excess consumption of platelets in blood vessels, leading to thrombocytopenia. Idiopathic/immune thrombocytopenic purpura (ITP) is an autoimmune disease of unknown origin (idiopathic) where the body’s immune system attacks and kills normal platelets. The immune system forms an antiplatelet antibody against the specific platelet surface molecule GpIIb/IIIa. The destruction of these normal platelets leads to thrombocytopenia and subsequent bleeding. Increase destruction of platelets can also be caused secondarily to other diseases. Diseases such as hemolytic uremic syndrome (HUS) occur after an infection of a specific strain of E. coli (O157:H7). HUS is due to a toxin formed by these bacteria and causes destruction of red blood cells leading to anemia, destruction of platelets leading to thrombocytopenia, and can even cause acute kidney failure. Another disease process that leads to platelet destruction is disseminated intravascular coagulation (DIC). This process is most commonly caused by severe bacterial infection (sepsis), obstetric complications, or certain types of cancers (leukemia or pancreatic cancer). This process, by several means, causes extensive clotting throughout the entire body, which uses up the majority of platelets and clotting factors in the blood. Since most platelets and clotting factors have been used up due to this disorder, it predisposes the patient to bleed elsewhere. This disorder is extremely severe and life threatening and has a poor prognosis. Platelet dysfunction induces bleeding disorders can also be due to innate defects of platelet functioning. These disorders are congenital and result in a normal number of platelets in the blood but these platelets lack a certain necessary function in clot formation and homeostasis. The most common of these platelet dysfunction diseases is von Willebrand disease (vWD). In normal platelets there is a molecule called von Willebrand factor (vWF) that has many different functions. The most important function of this molecule is the interaction with other signaling molecules and clotting factors inside the blood in response to tissue damage. These interactions eventually lead to the formation of clots and induce tissue repair. In patients with vWD, their platelets lack
normal amounts of vWF, which predisposes them to increased bleeding. Another congenital disease of normal platelet functioning is Bernard-Soulier disease, which is characterized by platelets lacking normal GpIb functioning. GpIb is a glycoprotein attached to the surface of platelets which functions to interact with other signaling chemicals in the blood in response to tissue damage. This interaction will eventually lead to the adhesion of platelets to that site of injury. Without this functioning surface glycoprotein, platelets cannot adhere to sites of damaged tissue to form clots, and will lead to increase bleeding. Another congenital disorder of platelets is called Glanzmann’s thrombasthenia where platelets lack the surface glycoprotein GpIIb/IIIa. This disease causes a dysfunction of platelets to aggregate together at the site of tissue damage. Yet again, there will be less clot formation and an increased amount of bleeding. Platelet dysfunction can also be secondary to a certain condition called essential thrombocytosis. In this disease, there is actually an increase in number of platelets in the blood but they lack their normal functions. Essential thrombocytosis is a type of myeloproliferative disorder where there is an excess in number of megakaryocytes in the bone marrow that produce an increased number of dysfunctional platelets. The exact cause of the platelet dysfunction in this disease is unknown but clinical features are similar to other platelet derived bleeding disorders. coagulation factors Besides platelets, the other most important aspect of clot formation and the ability of the body to control bleeding is the presence of clotting (coagulation) factors in the blood. Clotting factors are a group of molecules and enzymes that are activated in tissue damage and work in concert with platelets to eventually form clots and stop bleeding. These molecules are formed by the liver and are found freely circulating in the blood awaiting activation. There are about a dozen different clotting factors (each indicated by a different Roman numeral) that each plays a specific role in clotting, and any absence or defect in these molecules can cause bleeding disorders. Without sufficient amounts of functional clotting factors in the blood, clots will not form and the body is more prone to bleeding. This is especially evident after tissue injury where bleeding would normally be stopped
after clotting factors interact to form permanent clots. Clinical features of decreased amount of clotting factors are increased risk of spontaneous bleeding and bruising, prolonged time before clot formation, and bleeding into tissues such as joints, muscles, and body cavities. Several diseases and disease states can lead to decrease the production of clotting factors by the liver. One of the most common causes of decreased production of clotting factors is due secondarily to chronic liver failure or liver cirrhosis. Cirrhosis is a chronic disease of the liver where normal liver tissue is replaced by scar tissue and becomes nonfunctional. This disease is typically due to long-term liver damage caused by alcohol abuse or viral hepatitis infections. Because of the extensive functions of the liver, patients with cirrhosis will have dysfunctions of many organ systems. Since the liver is the only site for production of clotting factors in the body, decreased liver function will cause decreased synthesis of these molecules leading to prolonged bleeding. Another disease that will ultimately lead to decreased functional clotting factors is a deficiency in vitamin K. Vitamin K is an essential vitamin whose function is to convert several different clotting factors (factors II, VII, IX, X, and proteins C and S) from a nonfunctional form to a functional form. Vitamin K is found in many leafy vegetables and grains and is also produced by symbiotic bacteria living in our digestive tract. Vitamin K deficiency is relatively rare but can be present in special situations such as extensive intestine damage (inability to absorb vitamin K) or in newborns (newborns have sterile digestive tracts when born, so no bacteria are present to generate vitamin K). Without ample levels of vitamin K in the body, these clotting factors will be nonfunctional and will predispose the patient to bleeding. Normal levels of clotting factors will also be decreased in a category of congenital diseases called hemophilias. As with most congenital diseases, these hemophilias may be due to a defective gene passed down from one or both parents or may be due to a random mutation causing the disease. There are several different types of hemophilias, each categorized by the specific clotting factor that is lacking in that disease. Hemophilia A (most common hemophilia) is caused by a deficiency in normal levels of factor VIII, hemophilia B (Christmas disease) lacks factor IX, and hemophilia C lacks factor XI. These hemophilias share similar clinical features with other diseases where
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there is a deficiency in clotting factors: increase propensity to bleed, prolong time before clot formation, and abnormal bleeding into tissues. There is considerable variability in the severity and amount of bleeding between different patients with these diseases. Some patients may have the disease but be without clinical symptoms or some patients may have the disease and express severe bleeding and tissue damage. other causes of bleeding disorders Disorders of bleeding can be caused by things other than diseases involving platelets and clotting factors. There are certain medications whose effects and adverse reactions can cause bleeding disorders. A very common category of medications that were designed to change the normal functioning of bleeding in the body is anticoagulant drugs. Examples of this category of drugs are aspirin, warfarin, heparin, abciximab, clopidogrel, and dipyridamole. These medications act to prevent clot formation by different actions; several of them work against the actions of platelets (aspirin, abciximab, clopidogrel, dipyridamole) and a few work against clotting factor activity (warfarin and heparin), essentially causing a controlled bleeding disorder. These medications are used clinically to prevent the formation of blood clots in certain individuals. Individuals with a previous history of tissue damage caused by clot formation (e.g. stroke, heart attack, deep vein thrombosis, pulmonary embolism) and individuals at risk for such damage are placed on a specific anticoagulant medication to prevent clot formation and subsequent tissue damage. Some medications are used purposefully to cause changes in normal bleeding homeostasis and prevent clot formation, but some medications are used for entirely different reasons and have the adverse effect of causing bleeding problems. One example of a medication whose adverse side effect causes bleeding problems is a category of drugs called nonsteroidal antiinflammatory drugs (NSAIDs) such as aspirin, ibuprofen, and naproxen. NSAIDs are widely used to reduce mild to moderate pain, reduce body temperature during fevers, and also used to reduce inflammation. These medications are able to have these actions because they inhibit the formation of certain chemical signaling molecules inside the body called prostaglandins and “Bladder Diseases,” National Institute of Health, www.nlm.nih.gov/medlineplus (cited August 2007); “Bladder Diseases,” National Institute of Health, www.nlm.nih.gov/medlineplus (cited
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August 2007); thromboxanes. These chemical signals
are formed by the body’s natural reaction after tissue damage, but can lead to further tissue damage because of their role in activating and increasing inflammation. NSAIDs have the adverse reaction to increase bleeding because their effects on inhibiting thromboxanes, which normally have an important role in platelet activation and clot formation. As explained earlier, while certain individuals use aspirin to prevent clot formation, other individuals use aspirin (and other NSAIDs) for different reasons and the increased risk of bleeding is an unwanted side effect of using these drugs. Another class of medications that has the undesirable potential to cause bleeding disorders is certain antibiotics. Antibiotics can cause increased amount of bleeding primarily by their effects on intestinal bacteria. Administration of antibiotics is commonly done by oral route where absorption of the medication takes place in the intestines, and frequently not all is absorbed and some remains in the intestinal canal. Antibiotics inside the intestine can kill large amounts of normally present symbiotic bacteria that function to provide us with vitamin K. When antibiotics destroy these “good” bacteria in the intestine, the body has less vitamin K to be absorbed and becomes deficient in this essential nutrient. Subsequently a bleeding disorder may manifest. Antibiotics can, in effect, cause a pharmacological vitamin K deficiency and will show similar clinical presentations to this bleeding disorder. Bleeding disorders fall under many different categories of diseases and causes, which lead to problems of clot formation and increased propensity to bleed. The bleeding disorder may be due to innate disorders of the body’s normal clotting functioning (platelet and clotting factor activity) or may be due to some other cause like another primary disease state or due to certain medication adverse effects. Treatment of these disorders varies widely between different diseases and causes of the disorder, so it is important for physicians to be aware of potential bleeding disorders in patients and to know the specific clinical presentations of each. SEE ALSO: Anticoagulants; Clotting Factors; Hemophilia;
Homeostasis; Hypercoagulable Disorders; Platelets.
BIBLIOGRAPHY. Michael J. Farabee, “Animal Organ Systems
and Homeostasis,” (Estrella Mountain Community College, 2006); “What Are Coagulation Disorders?” National Hemo-
philia Foundation (2006); B. Furie, “Thrombus Formation In Vivo,” Journal of Clinical Investigation (v.115/12, 2005); Marcel Levi and Hugo ten Cate, “Disseminated Intravascular Coagulation,” New England Journal of Medicine (v.341/8, 1999); “Vitamin K for Newborn Babies,” Department of Health (UK) Circular (May, 1998); “Aspirin FAQ’s,” Bayer Healthcare (2007). Angela Garner, M.D. Ryan Strain University of Missouri– Kansas City
Blepharitis Blepharitis is a disorder of the eyelids characterized by redness, thickening, and crusting as a result of chronic inflammation. Symptoms include burning, stinging, crusting, and foreign body sensation. It is a very common external eye problem whose etiology is not entirely clear. It is often divided into anterior and posterior blepharitis. Anterior blepharitis is further characterized by its association with staphylococcal overgrowth or seborrheic dermatitis. Posterior blepharitis is related to meibomian gland dysfunction with or without accompanying acne rosacea. Staphylococcal blepharitis is caused by a chronic infection of the base of the lashes. Secondary skin ulceration, crusting of the lashes, and recurrent sty formation result. It is characterized by itching, tearing, burning, and light sensitivity. Pustules in these areas eventually become ulcerated and form a crust that bleeds when removed. This can be a recurrent problem; scarring of eyelids or sparse, misdirected eyelashes (trichiasis) can occur. The first-line treatment of staphylococcal blepharitis is an antibiotic ointment along with lid hygiene. Lid hygiene consists of warm compresses followed by lid massage and scrubs three times a day. Seborrheic blepharitis is characterized by dry or greasy flakes, easily removed from the lid margin. It is often associated with seborrheic dermatitis (dandruff of scalp and eyebrows and facial scaling). Secondary bacterial colonization often occurs with a propensity for oil and skin cells. Appropriate treatment includes treating the underlying seborrhea and also lid hygiene. If bacterial overgrowth develops, an antibiotic may be added to the treatment regimen. Meibomian gland dysfunction is characterized by dilated meibomian glands on the back surface of the
Blepharospasm
eyelid margin. Copious amounts of inspissated lipid material can be expressed. The tear film layer appears oily and foamy. This type of blepharitis is easy to miss and the symptoms appear out of proportion to the minimal clinical findings. When associated with acne rosacea, telengiectatic (dilated) blood vessels and thickening of the lid margins are also present. The patient will also have associated skin redness, acne, and telangiectasias on the forehead, upper cheekbones, and nose. Treatment for posterior blepharitis includes lid hygiene, antibiotics, mild topical steroids, and occasionally doxycycline. Doxycycline alters the underlying composition of the oil glands and allows for improvement of function. Any underlying skin disorders also need to be treated concomitantly. Although this is a prevalent ocular disease worldwide, certain risk factors have been associated with its occurrence, including autoimmune disorders and acquired immunodeficiency states. It is also important to note that while many cases of blepharitis may be benign and chronic, any prolonged inflammation of the eyelid must also be differentiated from sebaceous cell, squamous cell, or basal cell carcinoma, as all may present with similar clinical findings. SEE ALSO: Acne; Blepharospasm; Eye Care; Eye Diseases
(General); Ophthalmology; Rosacea.
BIBLIOGRAPHY. Laurence L. Brunton, Goodman and
Gilman’s The Pharmacological Basis of Therapeutics (McGraw-Hill, 2006); Mark Dambro and Jo Griffith, Griffith’s 5 Minute Clinical Consult (Lippincott Williams and Wilkins, 2006); Merck Manual of Diagnosis and Therapy (Merck, 1999); Lawrence Tierney, Stephen McPhee, and Maxine Papdakis, Current Medical Diagnosis and Treatment (McGraw-Hill, 2006). Komal Bharat Desai, M.D. Swathi Tella Independent Scholars
Blepharospasm Blepharospasm, characterized by recurrent spasm of the orbicularis oculi muscle, is a disease where patients demonstrate uncontrolled blinking, twitching,
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or closure of the eyelids. Symptoms are most commonly bilaterally found, and usually manifest in the fifth to seventh decades. Women are more affected than men, with a 3:1 ratio. The high incidence of movement disorders among first-degree relatives of patients with blepharospasm suggests that the condition is genetically transmitted. Patients often display a grimacing expression with involuntary closure of the eyes, and symptoms often disappear in sleep. Blepharospasm is usually idiopathic, or may be secondary to ocular irritation, such as corneal or conjunctival foreign body, trichiasis, blepharitis, or dry eye syndrome. It is speculated that the condition is related to basal ganglia dysfunction, and is exacerbated by fatigue or stress, suggesting that there may be a psychological component to the condition. Severe blepharospasm may lead to functional blindness. Meige syndrome is blepharospasm with uncontrollable facial, head, and neck involvement. Hemifacial spasm should be considered in the differential diagnosis for blepharospasm; patients with this manifest unilateral facial spasms that involve both the upper and lower face. This condition is usually idiopathic but may be secondary to the compression of the facial nerve by an artery or by a posterior fossa tumor. Magnetic resonance imaging (MRI) should be obtained in all patients where this is a suspicion to rule out malignancy. Other conditions to be considered in the differential diagnosis include Tourette syndrome, trigeminal neuralgia, tardive dyskinesia, and eyelid myokymia. Eyelid myokymia usually involves the lower eyelid, and is unilateral in nature. The twitches are commonly triggered by stress or caffeine. While some cases of blepharospasm spontaneously resolve, most cases require some form of treatment. Any underlying disorder contributing to ocular irritation should be appropriately treated. If an underlying disorder causing ocular irritation has been ruled out, treatment of blepharospasm includes psychotherapy, neuroleptic pharmacological therapy, biofeedback training, hypnosis, and botulinum toxin. Haloperidol, clonazepam, bromocriptine, and baclofen have all shown limited success. Botulinum toxin, the current first-line therapy, can be injected into the orbicularis muscles. This type of treatment is often reserved for severe cases of blepharospasm. Injections are usually repeated
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every 12 weeks, indefinitely. Side effects include transient ptosis and diplopia. If the patient is unresponsive or intolerant to these therapies, surgical ablation of the facial nerve or extirpation of the orbicularis muscles may be considered. SEE ALSO: Blepharitis; Eye Care; Eye Diseases (General);
Ophthalmology.
BIBLIOGRAPHY. J. Costa, et al., “Botulinum Toxin Type A
Therapy for Blepharospasm,” Cochrane Database of Systematic Reviews (v.1/CD004900, 2005); Peter K. Kaiser, Neil J. Friedman, and Roberto Pineda II, The Massachusetts Eye and Ear Infirmary Illustrated Manual of Ophthalmology (Saunders, 2004); ���������������������������������� Derek Y. Kunimoto, Kunal D. Kanitkar, and Mary S. Makar, The Wills Eye Manual (Lippincott Williams & Wilkins, 2004); Paul Riordan-Eva and John P. Whitcher, Vaughan & Asbury’s General Ophthalmology (McGraw-Hill, 2004); A.H. Ropper, R.H. Brown, and D. Phil, Adams and Victor’s Principles of Neurology, 8th ed. (McGraw-Hill, 2005). Komal B. Desai, M.D. Independent Scholar
Blindness The World Health Organization (WHO) defines blindness as the inability to read the largest letter on a vision chart at a distance of 10 feet. In 2002, 37 million people worldwide met this definition, with 90 percent living in developing countries. An additional 124 million people had low vision, defined as the inability to clearly see at a distance of 20 feet what individuals with normal vision can see at a distance of 60 feet. Blindness and low vision are global health problems of particular significance because they confer decreased life expectancy, quality of life, and economic productivity. Notably, at least 75 percent of world blindness is thought to be entirely treatable or preventable, and the eradication of unnecessary blindness has become the focus of a number of organizations and promising global health initiatives. Given the scope of this issue, it is helpful to consider the causes of blindness in developing and developed countries separately.
The Vision 2020 initiative may prevent over 100 million cases of blindness and save an estimated U.S. $223 billion worldwide.
Causes in the Developing World A cataract is an opacity in the lens of the eye that can have many causes but is most often age related. It is the most common cause of world blindness, treatable or otherwise, accounting for almost 50 percent of cases. Cataract surgery, which involves surgical removal of the lens usually followed by the implantation of a synthetic intraocular lens, is extremely cost-effective. A number of medical centers and temporary camps in developing countries perform affordable, high-volume cataract surgery to address the substantial backlog of affected individuals. However, despite these efforts, the number of cataract blind is antici-
pated to double in the next 20 years as the population increases in both size and age. Glaucoma is a group of diseases characterized by damage to the optic nerve of the eye, usually associated with elevated pressure within the eye. Affecting an estimated 12 million individuals worldwide, glaucoma is the second most common cause of world blindness, as well as the leading cause of blindness among African Americans. The goal of glaucoma treatment is to prevent damage to the optic nerve through the use of medications and surgical interventions that decrease the pressure within the eye. Trachoma is the most common infectious cause of blindness in the world, and is most prevalent in developing countries where crowding, poor hygiene, and limited access to water are particularly problematic. The causative bacterium, C. trachomatis, is spread through contact with eye discharge from infected individuals, typically carried by flies. Repeated episodes of trachoma cause scarring of the conjunctiva and eyelid deformities, which in turn lead to corneal scarring, ulceration, and eventual blindness. Trachoma can be effectively treated with antibiotic therapy consisting of oral azithromycin or tetracycline eye ointment. Because infection tends to recur, current public health efforts are focused on prevention through improving facial hygiene and access to clean water. Onchocerciasis is also known as “river blindness” because the blackfly that transmits the parasitic worm Onchocerca volvulus is most abundant near fast-flowing rivers. Upon biting its human host, the infected blackfly transmits larvae that mature into adult worms; these in turn produce larvae that migrate to the skin and ocular tissues where they cause a locally damaging immune response to the skin and eyes upon dying. The blinding complications of onchocerciasis are effectively prevented with the antiparasitic agent ivermectin. Additional public health efforts have promoted the use of insect repellents, protective clothing, and insecticidal spraying. Vitamin A deficiency is the leading cause of preventable blindness in children. It is estimated that more than 100 million children have the condition, which can cause night blindness, drying of the cornea, and ultimately irreversible corneal damage. The condition also increases the severity and risk of acquiring infections such as measles. Vitamin A supplementation is inexpensive and effective, de-
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creasing child mortality by 25 percent and as much as 50 percent in children with measles. Breastfeeding and nutrition education represent additional means of prevention. Low vision affects 124 million individuals and may be due to any of the causes of blindness mentioned here. Many more individuals not included in this number have low vision due to uncorrected or undercorrected refractive error (myopia, hyperopia, and astigmatism). It is estimated that 25 percent of individuals with low vision may benefit from services including corrective lenses, low vision aids, and mobility training. Leprosy is a chronic infection by the bacterium Mycobacterium leprae that affects the skin and peripheral nerves. Leprosy can also cause damage to the cornea and nerves of the eye that eventually results in scarring and blindness. These irreversible ocular complications can be avoided through early treatment with multidrug therapy (MDT) consisting of dapsone, rifampin, and clofazimine. Widespread use of MDT has significantly decreased the prevalence of leprosy from 5.2 million infected individuals in 1985 to 286,000 cases in 2004. Other important causes of blindness in the developing world include age-related macular degeneration and diabetic retinopathy (see next section), as well as HIV and corneal opacity. Causes in the Developed World Age-related macular degeneration (AMD) is a chronic, degenerative condition that affects the part of the eye responsible for central vision. In developed countries, it is the leading cause of blindness in individuals over the age of 65. There are two forms of AMD, dry and wet, with the wet form accounting for most cases of blindness. Treatment options are limited, though some studies have demonstrated a benefit from increased intake of certain antioxidants. Laser therapy and injectable medications that prevent the growth of abnormal blood vessels seen in the wet form of the disease may also be helpful. Diabetic retinopathy is the most important ocular complication associated with diabetes mellitus, and is the leading cause of blindness for individuals between the ages of 20 and 74 in the United States. In addition, the WHO estimates that in 2002 diabetic retinopathy accounted for 5 percent of world
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blindness, or almost 5 million individuals. Blood glucose control represents an important means by which individuals with diabetes mellitus may prevent or slow the progression of diabetic retinopathy. Laser therapy and a procedure called vitrectomy may be helpful in more advanced forms of the disease. Other important causes of blindness in the developed world include cataract and glaucoma (see previous section). Global Efforts In 1999, the WHO and the International Agency for the Prevention of Blindness (IAPB) launched an initiative called Vision 2020: The Right to Sight. The goals of the initiative are to eliminate preventable blindness by the year 2020 and to improve resources for the rehabilitation and education of individuals with irreversible vision loss. The initiative identifies five major priorities: cataract, refractive error and low vision, trachoma, onchocerciasis, and childhood blindness. Successful implementation of this initiative will prevent over 100 million individuals from developing blindness and save an estimated U.S. $223 billion worldwide. Data from 2004 suggest that progress is being made with regards to the treatment and prevention of blindness due to infectious disease, but the prevalence of blindness due to other conditions is increasing. Challenges include training, development of infrastructure and technology, and cooperation by individual countries. Much work remains to be done, and the many programs and organizations dedicated to global eye health continue in their efforts to address this important issue. SEE ALSO: Age-Related Macular Degeneration; Cataract;
Cornea and Corneal Disease; Diabetes; Glaucoma; Leprosy; Low Vision; Onchocerciasis; Refractive Errors; Trachoma; Vitamin A Deficiency; World Health Organization (WHO). BIBLIOGRAPHY. World Health Organization (WHO),
State of the World’s Sight: VISION 2020: The Right to Sight: 1999–2005 (WHO, 2005).
Geoffrey C. Tabin, M.D. University of Utah School of Medicine Kurt H. Kelley University of Vermont College of Medicine
Blood/Blood Transfusion The concept of blood transfusion has existed for centuries—the Romans first attempted to transfuse patients orally, without success. The administration of animal blood in transfusions was documented as late as the 1600s, with unsatisfactory results. It was not until the 1900s that Landsteiner discovered the blood typing system (ABO), which, along with Lister’s concepts of sepsis, sterility, and blood anticoagulation, paved the way for successful blood transfusions. Blood transfusion today is not without risk, but modern science has made it very safe. The majority of blood is made up of red blood cells, white blood cells, platelets, and plasma. Red blood cells (RBCs) are responsible for carrying oxygen from the lungs to all tissues of the body, including the heart and brain. RBCs have other functions, such as buffering the blood of acids and playing a role in carbon dioxide (waste gas) management. RBCs are made in the bone marrow by stimulation of hormones from the kidneys. The essential component of RBCs is hemoglobin, which is a molecule with a central iron atom component in its center. Without this iron, the RBC is unable to carry oxygen. A person with low iron is anemic, meaning they have fewer functional RBCs, resulting in decreased ability to circulate oxygen around the body. This usually results in the anemic person becoming easily fatigued. The amount of RBCs in the blood can be measured in two ways. It can be measured as a percentage called the hematocrit, which is the amount of cells per volume of blood. The average is around 45 percent, meaning approximately 45 percent of the blood volume is RBCs. The remaining volume is plasma or other cells. The amount of RBCs in the blood can also be determined by using the amount of hemoglobin present (the functional component of RBCs). This value is usually about one-third of the hematocrit or 15 g/dL on average. White blood cells are a diverse group of cells that all function in fighting infection. The different types of white blood cells are neutrophils, basophils, monocytes, macrophages, eosinophils, B-cells, and T-cells. Certain cells are responsible for fighting bacterial infections, others for viral infections, and still others are better at fighting fungal infections. Neutrophils are better at killing bacteria, T-cells are essential in many viral infections, and macrophages help the body get rid of
many fungal infections. All of these cells work together to keep our bodies free of infection; the lack of any one of these cells can result in life-threatening infections. Platelets, also made in the bone marrow, function in blood clot formation. They bind to exposed blood vessel walls when they are damaged. This binding triggers a cascade of chemical events that leads to blood clot formation. Included in this cascade are several chemical molecules, or factors, that stabilize the clot by forming a mesh-like network of fibers over the platelets. Thus, it is the initial platelet binding to the cut blood vessel walls and then the chemical reaction of molecules called factors that creates a watertight plug preventing further escape of blood from damaged blood vessels. Plasma contains mostly water and ions like calcium, sodium, potassium, and chloride. Plasma makes up the majority of the volume of blood. It is the carrying medium of all of the cells, ions, clotting factors, and other molecules like albumin. Albumin is a large carrier molecule analogous to a dump truck that carries smaller molecules and dissolved drugs in the blood stream around the body. Oxygen is not very soluble (does not dissolve well) in plasma, so the majority of oxygen is carried by RBCs. blood transfusion A blood transfusion is when blood from one person or blood from multiple people is combined and put into the blood circulation of another. Blood products that are transfused can be composed of any of the previously discussed parts of blood. It can be composed of a single part of blood like plasma or can be all of the components of blood, which medically is called whole blood. What determines the need for a blood transfusion can be complex. Different medical conditions require different types of blood transfusions. Transfusions are done for blood loss (as in loss from a motor vehicle collision or surgery) or blood disorders exhibiting missing components of blood plasma, such as hemophilia (which is a disease with missing clotting factors). For example, if one sustains a large loss of blood from a gunshot wound, this necessitates replacement. Next, one may inquire what needs to be replaced; the answer lies in what was lost. If all of the components of the blood are lost, then they all must be replaced in order to restore harmony of the blood. So in this ex-
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ample of trauma secondary to a gunshot wound, both red blood cells and plasma are replaced. Once it is determined that a patient will need or may need a transfusion, tests must be done to make sure the proper type of blood is given. As described above, several blood groups exist. Blood typing is the test where the blood type (A, B, or O) is determined. Screening is also done to check for positive or negative blood for other blood cell determinates. A person who is type O negative is considered the universal donor because anyone can receive this type of blood without fear of the recipient’s body reacting against it. Type AB positive is considered the universal recipient, because this blood will not react with blood added to it inside of a person’s body. However, prior to any transfusion the blood to be transfused is reacted with the recipient’s blood just to make sure no adverse reactions occur. This mixing of the two bloods to look for reaction is called performing a crossmatch. This is analogous to checking in the laboratory for any blood incompatibilities (false matches) in order to prevent mistakes. Current evidence suggests that adverse reactions from transfusions most commonly encountered today are not due to computer error, but to human error. Human error occurs when the incorrect blood is given to a person because of mislabeling or improperly checking blood prior to transfusion. To reduce risk in blood transfusions, modern laboratories check blood for the presence of the human immunodeficiency virus, hepatitis B and C, cytomegalovirus, and even more commonly bacteria of various types. Blood tests are very good and the incidence of disease contracted from blood products is relatively low. In light of these risks, it is law that a patient must be informed of the risks of transfusion (especially the risk of infection) before a transfusion can be performed. The exception to this, of course, is if the patient may not live without the life-saving transfusion and that person is unable to give consent. Various methods of preventing the need for transfusion are available. One is simply to save some blood ahead of time, which is usually only done when a major surgery is anticipated. In this scenario, several weeks prior to major surgery blood is withdrawn from the patient and put in a blood bank. With the help of hormones, the patient’s body then replenishes the blood drawn off. If during the surgery a transfusion
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is necessary, one’s own blood can be used, eliminating all of the possible complications of blood transfusion. One other common and probably more practical method exists. Prior to surgery blood is withdrawn from a patient, and the volume of blood that is drawn is replaced with fluids through an IV. In essence, the amount of blood cells has been diluted, and so for a given volume of blood that is lost, less actual blood cells are lost. After the surgery, the blood that was withdrawn is returned, thus replacing the lost volume from the surgery with blood rich in red blood cells. Blood transfusions are a vital component of life saving procedures used in medicine. Many types of transfusions exist, and the proper transfusion must be matched with the correct need in order to benefit the patient. Blood transfusions are not without consequence. Even with superior medical science and technology errors occur and tests are not perfect. Consequently, blood transfusions should be reserved for those who are truly in need. See also: AIDS; Hematologist; Hematology; Hepatitis;
Hepatitis C; Surgery.
Bibliography. L.T. Goodnough, M.E. Breacher, and M.H.
Kanter, “Transfusion Medicine. First of Two Parts—Blood Transfusion,” New England Journal of Medicine (v.340/6, 1999); L.T. Goodnough, M.E. Breacher, and M.H. Kanter, “Transfusion Medicine. Second of Two Parts—Blood Transfusion,” New England Journal of Medicine (v.340/7, 1999); R.S. Hillman and K.A. Ault, Hematology in Clinical Medicine, 3rd ed. (McGraw-Hill, 2002); J.G. McFarland, “Perioperative Blood Transfusions: Indications and Options,” Chest (v.115/5 Suppl., 1999). Angela Garner, M.D. University of Missouri, Kansas City
Body Cell Mass The body cell mass of a person is the total mass of all the cellular elements in the body that constitute the metabolically active tissue in the body. Unlike the weight of a person, this does not include parts of the body that are not active and that result in a depletion of the body cell mass over time, such as with the wasting of the
body that takes place when a person is suffering from chronic conditions such as terminal cancer or AIDS. To calculate the body cell mass, one includes in the measurement all the organ and muscle tissue, the intracellular and extracellular water, and the bone tissue. Although the purpose is often to obtain the overall body cell mass, it is usually just as important to get the relative percentages of each part of the body. For most well-nourished people, the muscle tissue is expected to account for approximately 60 percent of the body cell mass, with organ tissue accounting for another 20 percent, and the remainder made up of red cells and tissue cells. The body cell mass is expected to contain between 98 and 99 percent of all the body’s potassium. Generally, the method used for working out whether the body cell mass has been depleted is by using bioelectrical impedance analysis, which can be performed by many medical doctors. It does not involve any X-rays—in fact, there is no recourse to radiation—and it can get highly accurate results. The figures obtained by the bioelectrical impedance analysis are then combined with other body statistics such as sex, age, height, and weight, which are then used to calculate the body cell mass and obtain further figures that can be used to assess the health or otherwise of the person under observation. SEE ALSO: AIDS; Body Surface Area; Cancer (General). BIBLIOGRAPHY. Francis D. Moore, The Body Cell Mass and
Its Supporting Environment: Body Composition in Health and Disease (Saunders, 1963); Richard N. Pierson, Quality of the Body Cell Mass: Body Composition in the Third Millennium (Springer-Verlag, 2000).
Justin Corfield Geelong Grammar School, Australia
Body Mass Index Body mass index (BMI) is a calculation of a person’s weight compared to his or her height. It is also known as the Quetelet index, named after Adolphe Quetelet, who developed the formula in the mid-1800s. BMI is calculated by taking a person’s weight (in kilograms)
divided by the person’s height squared (in meters). Originally, BMI was thought to be a good estimation of the amount of fatty tissue within a person, but some limitations do exist. The range of indices can vary from about 15 (which is starvation) to over 40 (morbidly obese). This range is further subdivided into underweight, normal weight, overweight, obese, and morbidly obese. The definition of underweight is a BMI less than 18.5, while a BMI of greater than 25 is considered overweight. A person with a BMI between 18.5 and 25 is classified as normal weight. BMI above 30 is considered obese, and above 40 is morbidly obese. These ranges are only applicable to adults, and may vary due to ethnicity. In children, BMI is calculated in the same manner; however, the use of the index is different compared to adults. BMI in children should be compared by age and sex for interpretation. It is calculated and compared in a percentile fashion rather than the index number alone. Children above the 95th percentile for their age and sex are considered overweight, and children who have a BMI greater than the 85th percentile have a greater risk of becoming overweight. Those who are under the 5th percentile for age and sex are considered underweight. While BMI is an easy and inexpensive measurement, it can be a fairly inaccurate measurement of body fat due to the fact that it does not take into account muscle mass, bone structure, fat percentage, or body type. This is why a professional football player will be regarded as overweight or obese, and a marathon runner as underweight. Even with these limitations, BMI is acceptable for monitoring weight trends in inactive and overweight persons. This is because while monitoring BMI, we know that the person’s height is unchanged. In the United States, BMI is also used for defining those with eating disorders. According to the Diagnostic and Statistical Manual, one of the criteria for the diagnosis of anorexia nervosa is a BMI below 17.5. Nutritional status can also be determined for these people if a BMI trend is followed. In the elderly population, there can be a misleading trend of decreasing BMI. This is because as one ages, the amount of muscle mass starts to decrease, while the amount of fatty tissue is increasing. Because muscle is denser than fat, a decreasing BMI does not mean a decrease in fatty tissue. In fact, in the elderly population, it is more likely that they will gain fatty tissue.
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SEE ALSO: Nutrition; Obesity. Bibliography. Linda A. Ferrera, Body Mass Index: New
Research, (Nova Science Publishers, Incorporated, 2005); H.M. Seidel et al., Mosby’s Guide to Physical Examination, 5th ed. (Mosby, 2003). George P. Kolo, D.O. Kansas City University Brett D. Dunbar Independent Scholar Roberto Taarea Independent Scholar
Body Surface Area Body surface area is the surface of a human body that can be measured or calculated. In more literal terms, body surface area is the skin, which covers a human body. It is often difficult to measure one’s surface area, thus body surface area is usually just an estimate based upon the height and weight of the person. Body surface area is commonly used in medicine because it is an indicator of metabolic mass, as opposed to body weight, which can be skewed due to adipose tissue. Drug dosage and administration of IV medications is determined by body surface area. Some of the uses of body surface area include renal function, cardiac index, chemotherapy, and glucocorticoid dosing. There are certain facts that may be correlated with body surface area. In mammals, body surface area may be correlated with basal metabolic rate, which is the rate at which energy is used by an organism when it is at complete rest. One’s basal metabolic rate can be expressed as the calories that are used per square meter of body surface area per hour. Body surface area may also be correlated with blood volume in a warm-blooded animal. Aspects of the human body that are not correlated to body surface area are things such as glomerular filtration rate and liver function, both of which are related more to the internal working of each related organ. Medically speaking, body surface area has been important in prescription drug dosing. An example of this is anticancer drug dosing; such dosing has been related
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Bolivia See also: Body Cell Mass; Cancer Chemotherapy; Phar-
macology.
Bibliography. Tsutomu Kouno, et al., “Standardization
of the Body Surface Area (BSA) Formula to Calculate the Dose of Anticancer Agents in Japan,” Japanese Journal of Oncology (v.33/6, 2003); Vinay Kumar, Nelso Fausto, and Abul Abbas, Robbins & Cotran Pathologic Basis of Disease, 7th ed. (Saunders, 2004); R.D. Mosteller, “Simplified Calculation of Body Surface Area,” New England Journal of Medicine (v.317/17, 1987).
Angela Garner, M.D. University of Missouri-Kansas City
Body surface area is used as an indicator of metabolic mass instead of using body weight, which can be skewed due to adipose tissue.
to body surface area since the 1950s. Chemotherapy is a treatment that is offered and dosed using body surface area, rather than body weight, for two reasons. First, according to the National Cancer Foundation, body surface area has been shown to give a more accurate cross-species comparison of activity and toxicity for some drugs. Second, body surface area is more closely correlated to cardiac output. This is important because cardiac output determines how much blood flows to the liver and kidney, both of which influence how much drug is eliminated. If a drug dose is supposed to be related to body surface area, it is imperative that body surface area is carefully calculated. Although there are several formulas for calculating body surface area, one of the classic ways is the DuBois and DuBois formula, which was first developed in 1916. The formula is: BSA (m²) = Wt (kg)0.425 x Ht(cm)0.725 x 0.007184. An average body surface area for a man is 1.9 square meters, and for a woman 1.6 square meters. An average 9-year-old child’s body surface area is 1.07 square meters, while that for a 10-year-old child is 1.14 square meters. Controversy has arisen in recent times because of the pharmacokinetics of drugs. Different individuals all have varying abilities to metabolize drugs. Therefore, even if drug doses vary with body surface area it is important to monitor the patient using other factors, such as glomerular filtration rate.
Bolivia Throughout its history, Bolivia has been beset with political and civil unrest. Even after democratic civil rule was established in 1982, widespread poverty, racial tensions (two-thirds of the population are indigenous), and illegal drug use continued to limit the government’s ability to provide adequate health and social programs for the population of 8,989,046. Bolivia’s population has tripled over the last half-century, and resources are strained. A debt-forgiveness plan is under way to take some of the burden off the government so that greater resources can be directed to social programs. Bolivia’s Strategic Health Plan has been instituted with the intention of eradicating poverty through family planning, domestic violence prevention, and Basic Health Insurance and National Mental Health programs designed to close the health gap between the poor and the rest of the population. Universal Maternal-Child Insurance is an important part of this program. The health plan also calls for universal access to healthcare through individual, family, community, and government cooperation. Around one-tenth of Bolivia’s national budget is allotted to healthcare. The government designates 6.7 percent of the Gross Domestic Product (GDP) for such expenditures and spends $176 (international dollars) per capita on healthcare. The government provides 64 percent of healthcare funding, and the private sector funds 36 percent. Out-of-pocket expenses furnish
79.30 percent of all private expenditures. Social security spending accounts for 65 percent of government spending. There are 1.22 physicians. 3.19 nurses, 0.1 midwives, 0.71 dentists, and 0.55 pharmacists per 1,000 population in Bolivia. Eight percent of Bolivia’s workforce is unemployed, and there is widespread underemployment. With a per capita income of only $2,900, Bolivia is one of the poorest and least developed countries in Latin America, ranking 160th in world incomes; 64 percent of the population live in poverty. Some 20 percent of the population are malnourished, and 34 percent live on less than $2 a day. More than 14 percent survive on less than $1 a day. Income is unequally distributed, with a Gini index of inequality of 60.6 percent. The richest 10 percent of the population share 32 percent of resources and the poorest 10 percent survive on only 1.3 percent. Life expectancy is only 65.84 years, with women living an average of six years longer than men. While most of the male population (93.1 percent) is literate, only 81.6 percent of females are considered so. Primary school enrollment is reported at 95 percent and secondary school enrollment at 88 percent. More than one-fifth of children between the ages of 5 and 14 are in the workforce. While 95 percent of urban residents have sustained access to safe drinking water, only 68 percent of rural residents have such access. Some 58 percent of urban residents have access to improved sanitation, but less than a quarter of rural residents have this basic health requirement. The United Nations Development Programme (UNDP) Human Development Reports rank Bolivia 115th of 177 countries on overall quality-of-life issues. At 2.85 children per woman, Bolivia has the 88th highest fertility rate in the world. Contraceptive use is around 58 percent. Skilled personnel attend 67 percent of all births, and 79 percent of women receive prenatal care. Maternal mortality is extremely high at 420 deaths per 100,000 live births, and Plan Vida has been instituted with the goal of halving maternal mortality. Bolivia’s children are also particularly vulnerable to poverty and inadequate healthcare. The current infant mortality rate is 51.77 deaths per 1,000 live births, the 61st highest ranking in the world. Nevertheless, the government has made great strides in reducing childhood mortality. Between 1990 and 2004,
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under-5 mortality plummeted from 125 to 69 deaths per 1,000 live births, and infant mortality decreased from 89 to 54 deaths per 1,000 live births. Seven percent of infants are underweight at birth, and 8 percent of under-5s are moderately underweight. One percent of this group is severely underweight. One percent of under-5s experience moderate-to-severe wasting, and 27 percent suffer from growth stunting. The government of Bolivia subsidizes only 34 percent of required vaccines, but international organizations have stepped in to promote childhood immunization. As a result, 94 percent of infants are vaccinated against diphtheria, pertussis, and tetanus (DPT1), and 93 percent against tuberculosis. Some 84 percent are immunized against hepatitis B, and 81 percent receive DPT3 and Haemophilus influenzae type B vaccinations. Less than 80 percent are vaccinated against polio, and 64 percent receive measles vaccinations. HIV/AIDS is a growing problem in Latin America, and Bolivia has a 0.1 percent adult prevalence rate. Around 5,000 people have this disease, which has claimed some 500 lives. In 1997 Bolivia experienced outbreaks of both cholera and yellow fever, and the latter resurfaced two years later. SEE ALSO: Healthcare, South America. Bibliography. Central Intelligence Agency, “Bolivia,”
World Factbook, www.cia.gov (cited January 2007); Commission on the Status of Women, “Bolivia,” www.un.org/ womenwatch (cited January 2007); Manuel Antonio Garretón, et al., Latin America in the Twenty-First Century: Toward a New Sociopolitical Matrix (North-South Center Press, 2003); Carlos Gerardo Molina and José Nuñez del Arco, eds., Health Services in Latin America and Asia (Johns Hopkins University Press, 2001); Pan American Health Organization, “Bolivia,” www.paho.org (cited January 2007); Dagmar Raczynski, ed., Strategies to Combat Poverty in Latin America (Inter-American Development Bank, 1995); United Nations Children’s Fund (UNICEF), “Bolivia,” www.unicef.org (cited January 2007); World Bank, “Bolivia Data Profile,” devdata.worldbank.org (cited January 2007); World Health Organization, “Bolivia,” www .who.int (cited January 2007). Elizabeth Purdy, Ph.D. Independent Scholar
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Bone Cancer One of the less common cancers is that of the bone. Bone cancer occurs throughout the world and thus makes an impact on global health resources. Cancer of the bone rarely begins in the bone itself; more often, it is a result of cancer spreading from elsewhere in the body. Cancer that originates within bone cells is a primary bone cancer; if the cancer is a spreading of another tissue’s cancer, it is secondary bone cancer. Additionally, most tumors of the bone are benign. Only occasionally do they become cancerous. Primary bone cancer is classified into four major categories: osteosarcoma, chondrosarcoma, Ewing’s sarcoma, and spindle cell sarcoma. A sarcoma is any cancer of the connective tissues or supportive tissues. These tissues include blood vessels, bone, cartilage, fat, and muscle. Osteosarcoma, therefore, is a cancer in the bone itself. This type of cancer starts while the bone is still growing; thus, affected people are typically between the ages of 10 and 25 years old. An osteosarcoma will usually occur at the ends of long bones. Two common locations for such a sarcoma are in the thigh bone (femur) or shin bone (tibia); thus, osteosarcomas often occur around the knees. The excess bony substance produced is called an osteoid. Chondrosarcoma is cancer in the cartilage. Cartilage is a shiny substance that covers the ends of bones to cushion the joints. Chondrocytes are the cells that make cartilage—when chondrocytes grow and produce cartilage in an area of bone that normally would not have cartilage cover, a chondrosarcoma results. Chondrosarcomas usually begin when a person is above age 50. The third bone cancer, Ewing’s sarcoma, generally results from prior cancer treatment such as radiation or chemotherapy. It is a cancer of the nervous tissue in the bone marrow and affects younger people. These tumors are named after the surgeon who first described them, and are commonly seen in the pelvis. Along with being a bone cancer, Ewing’s sarcoma is one of a group of cancers called the Ewing’s family of tumors (EFT); other EFT cancers are extraosseous Ewing’s (EOE), primitive neuroectodermal tumor (PNET), and Askin’s tumor, or PNET of the chest wall. Although Ewing’s sarcoma affects the bone, EOE is around the bone, and PNETs are not in the bone, all EFT tumors originate in the same type of stem cell.
Spindle cell sarcomas include fibrosarcoma, leiomyosarcoma, malignant fibrous histiocytoma, and undifferentiated sarcoma of bone. The undifferentiated sarcomas are from cells that have not yet differentiated into specific bone cells. The remaining kinds of spindle cell sarcomas can be diagnosed by a pathologist based upon microscopic cellular analysis. Another type of cancer in the bones that is not in the above-mentioned categories is multiple myeloma. This cancer is of the bone marrow, typically in people between age 50 and 70. People whose lives have been affected by myeloma can often find support in groups for the cancers of the blood, which are also associated with bone marrow. These cancers include leukemia and lymphoma. There is also an International Myeloma Foundation, based in California. Numerous resources are available for people who have been affected by bone cancer. The American Cancer Society is one such information source. Another society is the International Society of Bone and Soft Tissue Pathology. When counting all races, male death rates to bone cancer in the United States between the years 2000 and 2003 were 0.5 men per 100,000; 0.3 women per 100,000 died from bone cancer in that period. The rates were highest for whites, then slightly lower for blacks and Hispanics, followed by Asians and Pacific Islanders, and the lowest mortality rate was found in American Indians and Alaska Natives. The most common symptom of bone cancer is pain in the bone. Activity may or may not aggravate this pain. The pain is generally described as dull or achy. Bone cancers do not originate from injuries such as a broken bone; however, the injury can cause the tumor to hurt. Additionally, a tumor may weaken a bone, making it more susceptible to breaking. Bone cancers can sometimes be visualized in an Xray. Some cancers make a gap in the bone; others cause excess bone growth. To aid in a diagnosis, blood and urine chemistry profiles can be taken. In some cases, a biopsy of the bone in question will be taken. A biopsy involves removal of a small section of tissue which is then analyzed under a microscope by a pathologist. To remove a cancerous bone tumor, the most common option is surgery. Often, this treatment is complemented with radiation and chemotherapy. If the tumor has metastasized, or spread to other tissues, the treatment becomes more difficult and the
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prognosis is not as good. A secondary bone cancer should be treated by a specialist in the field of the primary tissue cancer, as the secondary cancer will better respond to treatment for the primary cancer than it would respond to primary bone cancer treatment. SEE ALSO: American Cancer Society (ACS); American
College of Surgeons (ACS); Bone Diseases; Bone Health; Bone Marrow Diseases; Bone Mass Density; Bone Mineral Density; Cancer (General); Cancer Chemotherapy; Cancer Radiation Therapy; Diagnostic Tests. Bibliography. Jean-Jac Body, ed., Tumor Bone Diseases
and Osteoporosis in Cancer Patients: Pathophysiology, Diagnosis, and Therapy (Informa Healthcare, 2000); Alberto S. Pappo, ed., Pediatric Bone and Soft Tissue Sarcomas (Pediatric Oncology) (Springer, 2005); L.A.G. Ries, et al., eds., SEER Cancer Statistics Review, 1975–2003 (National Cancer Institute, 2003). Claudia Winograd University of Illinois at Urbana-Champaign
Bone Diseases Bone diseases have a major impact on affected individuals and their families, as well as on the population as a whole. Although some bone diseases lead directly to pain and deformity, bone disease is often a “silent” disorder until it causes fractures. The 1.5 million osteoporotic fractures in the United States each year lead to more than half a million hospitalizations, over 800,000 emergency room encounters, more than 2,600,000 physician office visits, and the placement of nearly 180,000 individuals into nursing homes. Hip fractures are by far the most troublesome type of fracture, accounting for about 300,000 hospitalizations each year. Caring for these fractures is expensive. Studies show that annual direct care expenditures for osteoporotic fractures range from $12 to $18 billion per year in 2002 dollars. Indirect costs (e.g., lost productivity for patients and caregivers) likely add billions to this figure. These costs could double or triple in the coming decades. From an individual’s perspective, bone disease has a devastating impact on patients and their families. While few die directly from bone disease, for many in-
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dividuals a fracture can lead to a downward spiral in physical and mental health that for some ultimately results in death. Bone diseases dramatically affect functional status. Many individuals who suffer fractures experience significant pain and height loss, and may lose the ability to dress themselves, stand up, and walk. These individuals are also at risk of complications such as pressure sores, pneumonia, and urinary tract infections. Nearly one in five hip fracture patients end up in a nursing home, a situation that a majority of participants in one study compared unfavorably to death. Many bone disorders other than osteoporosis add greatly to the burden of bone disease in the population. Thousands of Americans are affected by other bone diseases such as rickets and osteomalacia, renal osteodystrophy, primary hyperparathyroidism, osteogenesis imperfecta, Paget’s disease, bone cancer, and other developmental and acquired skeletal disorders. Estimates of the societal burden of these conditions are not readily available. The impact of these conditions on individuals, moreover, varies enormously, and is largely dependent upon the severity of the disease. Paget’s disease of the bone is a chronic bone disorder in which bones become enlarged and deformed. Bone may become dense but fragile because of excessive bone breakdown and deformation. Named for Sir James Paget (1814–1899), this disease affects 1 to 3 percent of people over 50 years of age, but affects over 10 percent of people over 80 years of age. Paget’s disease is the second most common bone disorder in people over 50 after osteoporosis. It is rarely diagnosed in young adults. Paget’s disease can affect one or more bones in the body. Most often, the pelvis, bones in the skull, the long bones (the large bones that make up the arms and legs), and the collarbones are affected. In addition, the joints between bones (e.g., the knees or elbows) can develop arthritis because of this condition. Normally, cells that break down old bone (osteoclasts) and cells that form new bone (osteoblasts) work in balance to maintain bone structure and integrity. In Paget’s disease, more bone breaks down than usual and more new bone forms than usual. These changes in the bone can lead to bone enlargement and deformity. The new bone growth tends to be softer and more fragile than normal bone, and can develop in a haphazard pattern. Because of this, the bone can fracture. The long bones, especially the legs, tend to bow, and the skull may enlarge, particularly over the forehead.
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Bone tumors may be benign (noncancerous) or malignant (cancerous). According to the National Cancer Institute (NCI), benign bone tumors are more common than malignant ones. Benign tumors do not spread and are usually not life threatening. However, they can grow and compress healthy bone tissue; they can also absorb or replace healthy tissue with abnormal tissue. Common benign tumors include the following: 1.) osteochondroma, which is the most common benign bone tumor, is marked by bony growths that project from the surface of the affected bone, and is most common among teens and young adults; 2.) giant cell tumor, which usually starts in the ends of bones, tends to occur more frequently in young adults, and can cause extreme pain; 3.) unicameral bone cyst or solitary bone cyst, which is a fluid-filled cavity that can weaken bones, leading to increased risk of fracture, and which is more common in children; and 4.) osteoid osteomas, which are small tumors that can develop on any bone, but are most often seen on the arms and legs. Cancer that arises in the bone is called primary bone cancer. Primary bone cancer is rare, with approximately 2,500 new cases diagnosed each year in the United States. Primary bone cancer is not the same disease as cancer that spreads or metastasizes to the bone from another part of the body, such as the breast, lungs, or prostate. When this happens, it is called secondary bone cancer. Multiple myeloma is a cancer that also affects bones, although it actually starts in the cells of the immune system. Some of the more common forms of primary bone cancer include osteosarcoma, which is the most common type of bone cancer. It develops in new tissue in growing bones, and tends to occur more frequently in children and adolescents. Common locations include the knees as well as the upper legs and upper arms. With Paget’s disease may come an increased risk for osteosarcoma. Another type of primary bone cancer is chondrosarcoma, which arises in cartilage and tends to occur more often in adults. Common locations include the pelvis, upper legs, and shoulders. Ewing’s sarcoma is thought to begin in immature nerve tissue in bone marrow. It tends to occur more frequently in children and adolescents. Common locations include the pelvis, upper legs, ribs, and arms. Bone cancer can be very painful. It can also interfere with normal movements and can weaken the bones, occasionally
leading to a fracture. Other symptoms may include fatigue, fever, weight loss, and anemia. These symptoms can also be caused by many other conditions. Osteopetrosis is a congenital condition in which the bones are overly dense. This happens because the body makes more new bone than it breaks down. Although the bones are dense, they are not very strong and tend to break more easily. In addition, problems with the bone marrow mean that the person’s immune system may be weakened. There are three major types of osteopetrosis. Malignant infantile form is very severe. It is inherited when both parents have an abnormal gene that is passed to the child. Intermediate form, which is less severe than the malignant infantile form, is found in children younger than 10 years old, and usually does not shorten life expectancy. Adult form, which is a milder type of osteopetrosis, is found in adults between 20 and 40 years old. This form rarely causes a significant reduction in life expectancy. Symptoms can include increased bone fractures, frequent infections, blindness, and/or deafness. Treatment options include medications and physical therapy. In severe cases, bone marrow transplant can be an option. Osteomalacia (which means soft bones) involves softening of the bones caused by a deficiency of vitamin D or problems with the metabolism of this vitamin. Like osteoporosis, osteomalacia weakens the bones and makes bones more likely to break. However, the process is different from that in osteoporosis. In osteoporosis, bone is broken down faster than it is re-formed. In osteomalacia, the two activities are balanced, but the bone that is formed does not become dense and hard (mineralized). Among older people, osteomalacia is much less common than osteoporosis. Osteomalacia may be caused by poor dietary intake or poor absorption of calcium and other minerals needed to harden bones. Osteomalacia is a characteristic feature of vitamin D deficiency in adults. Symptoms of osteomalacia include weakness, lack of appetite, weight loss, pain, and bones that fracture easily. The treatment of osteomalacia is by dietary change. Hormone supplements may also be helpful for postmenopausal women. Rickets is an abnormal bone formation in children resulting from inadequate calcium in their bones. Rickets most commonly affects children who may have low vitamin D levels due to poor diet or a condition (such
as celiac disease) that makes it difficult for the body to absorb vitamin D and calcium. Rickets is most likely to occur during periods of rapid growth, when the body demands high levels of calcium and phosphate. Lack of calcium can result from inadequate dietary calcium, inadequate exposure to sunshine (needed to make vitamin D), or from not eating enough vitamin D—a nutrient needed for calcium absorption. Vitamin D is found in animal foods, such as egg yolks and dairy products. Vitamin D is made by the body when it is exposed to ultraviolet rays in sunlight; these rays do not pass through ordinary window glass. Vitamin D is also added to milk, milk products, and multivitamin pills. Some people who do not get enough sun exposure, milk products, or green vegetables may also develop the disease, but that rarely happens anymore. Up through the first third of the 20th century, rickets was largely due to lack of direct exposure to sunlight or lack of vitamin D. Once the role of vitamin D in rickets was discovered, cod liver oil (which is rich in vitamin D) became a favored, if not too tasty, remedy. Thanks to such supplements of vitamin D, nutritional rickets has become relatively rare in industrialized nations. It still occurs, for example, in breast-fed babies whose mothers are underexposed to sunlight and in dark-skinned babies who are not given vitamin D supplements. In unindustrialized countries, vitamin D deficiency rickets continues to be a problem. Hereditary rickets is caused by an inherited disease that interferes with the resorption of renal tubular phosphate in the kidney. Rickets can also be caused by certain liver diseases. A similar disorder can occur in adults and is called osteomalacia. Then, it is caused by the inability of bone cells to calcify, or harden. Less frequently, nutritional shortage of calcium or phosphorus may produce rickets. Rickets is a failure to mineralize bone. This softens bone (producing osteomalacia) and permits marked bending and distortion of bones. Osteonecrosis occurs when a portion of bone loses its blood supply and begins to die. Doctors in the United States see about 10,000 to 20,000 new cases of osteonecrosis each year. Common locations include the knee and the hip, but other areas can be affected as well. The exact cause is unknown; factors that increase risk of developing osteonecrosis include previous fracture or trauma to the bone, corticosteroid use, obesity, certain diseases, and conditions including sickle cell anemia, lupus, and rheumatoid arthri-
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The estimated direct healthcare expenditure for osteoporosisrelated fractures alone is $12.2–17.9 billion annually.
tis. Osteonecrosis causes pain, swelling, and limited range of motion. Early treatment focuses on pain relief and efforts to prevent injury. Strengthening exercises and braces may also be used. In later stages, joint replacement surgery may be the best option. Osteoporosis is a disease of the bone in which the amount of bone is decreased, the strength of trabecular bone is reduced, cortical bone becomes thin, and bones are susceptible to fracture. Osteoporosis is a condition that features loss of the normal density of bone. Osteoporosis leads to abnormally porous bone that is more compressible like a sponge than dense like a brick. This disorder of the skeleton weakens the bone leading to an increase in the risk of breaking bones. Much more information on the frequency and burden of osteoporosis and other bone diseases is required if plans to prevent the projected “epidemic” are to be successful. Careful collection of national and local data on all osteoporotic-related fracture types is needed so that progress in meeting prevention goals can be measured. SEE ALSO: Bone Cancer; Bone Health; Bone Marrow Dis-
eases; Bone Mass Density; Bone Mineral Density; Osteoarthritis; Osteonecrosis; Osteoporosis; Paget’s Disease of Bone; Rickets. BIBLIOGRAPHY. S. Boonen, et al., “Functional Outcome
and Quality of Life Following Hip Fracture in Elderly
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Women: A Prospective Controlled Study,” Osteoporosis International (v.15/2, 2004); A. Brainsky, et al., “The Economic Cost of Hip Fractures in Community-Dwelling Older Adults: A Prospective Study,” Journal of the American Geriatrics Society (v.45/3, 1997); R.T. Burge, et al., “Methodology for Estimating Current and Future Burden of Osteoporosis in State Populations: Application to Florida in 2000 through 2025,” Value Health (v.6/5, 2003); W. Cockerill, et al., “Health-Related Quality of Life and Radiographic Vertebral Fracture,” Osteoporosis International (v.15/2, 2004); D.T. Gold, et al., “Paget’s Disease of Bone and Quality of Life,” Journal of Bone and Mineral Research (v.11/12, 1996); A. Praemer, S. Furner, and D. Rice, Musculoskeletal Conditions in the United States (American Academy of Orthopedic Surgeons, 1999); L.S. Rosen, “New Generation of Bisphosphonates: Broad Clinical Utility in Breast and Prostate Cancer,” Oncology (v.18/5 Suppl. 3, 2004); J.M. Torpy, C. Lynm, and R.M. Glass, “Osteopenia and Preventing Fractures,” Journal of the American Medical Association (v. 296/21, 2006); F.W. Wehrli, et al., “Quantitative MRI for the Assessment of Bone Structure and Function,” NMR in Biomedicine (v.19/7, 2006). Barkha Gurbani UCLA School Of Medicine
Bone Health The human bone is a remarkable organ. It provides the human body with various essential functions, such as serving as a support frame that provides structure and facilitates movement, providing protection of various soft tissues (i.e., spinal cord, brain), and serving as a reservoir for essential minerals, which are vital to maintaining normal physiologic homeostasis. These functions are influenced by a combination of internal body processes and environmental contributions. Abnormalities in either realm can lead to disease, which predisposes bone to becoming fragile and increases the risk of developing fractures. Bone is composed of both organic and inorganic components. The organic portion is comprised of mainly proteins, whereas the inorganic component is made of minerals, which are calcium and phosphorous. The interaction between the minerals and the proteins gives the bone its characteristic
strength. Overall, the human bone is a dynamic organ because it continuously changes its shape and size throughout a person’s lifetime. This dynamic process, known as modeling and remodeling, involves making new bone and breaking down existing bone. The skeletal health of an individual is dependent on both processes. An individual’s overall bone health can be affected by internal factors, such as their genetic composition and hormones, as well as external factors. Genetic abnormalities include defects in bone production that result in thin bones, such as osteogenesis imperfecta, as well as defects in bone breakdown that result in dense bones, such as osteopetrosis. Environmental factors may stem from nutritional deficiencies, which can result in rickets, or from iatrogenic causes such as certain medications. In addition, irregularity of the hormonal regulatory mechanisms that balance bone homeostasis can also result in poor bone quality, as is often the case with patients who have chronic kidney disease and are dependent on dialysis. Regardless of the mechanism, poor bone health leads to bones that are fragile and thus prone to fracture. Osteoporosis is by far the most prevalent bone disease worldwide. It is estimated that over 44 million Americans are at risk for osteoporosis, and 80 percent of those affected are women. While there are different types of osteoporosis, the most common form is age-related osteoporosis, which leads to changes in bone microarchitecture and decrease in bone mass. The overall result is bone fragility and propensity for severe fractures. The diagnosis of osteoporosis is established by screening with bone mineral density scans. Known risk factors that increase the likelihood of osteoporosis include being female, Caucasian or northern European descent, advanced age, estrogen deficiency, smoking, inactivity, malnutrition, and use of specific medications such as steroids or anticonvulsants. The importance of good bone health is illustrated by the impact of osteoporosis on both the individual and society. The most significant consequence of osteoporotic bones are fractures. It is estimated that over 1.5 million osteoporotic-related fractures occur in the United States annually. These fractures can be devastating and may not only decrease an individual’s quality of life, but also raise mortality risk. In addition, osteoporotic fractures incur significant societal costs in
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healthcare expenditures and loss of productivity. The estimated direct healthcare expenditure for osteoporosis-related fractures is $12.2–$17.9 billion annually. As the U.S. population ages, the importance of bone health and prevention of avoidable consequences, such as those of osteoporosis, becomes ever more critical. Health interventions focusing on public education, early assessment, and disease prevention will be essential components in promoting good bone health and minimizing the individual and societal costs of bone disease. SEE ALSO: Bone Diseases; Bone Mass Density; Bone Min-
eral Density; National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS); Osteogenesis Imperfecta; Osteoporosis. Bibliography. National Osteoporosis Foundation, www
.nof.org (cited December 2006); United States Department of Health & Human Services, www.surgeongeneral.gov (cited December 2006). Shen-Ying (Richard) Ma, M.D. University of Virginia Dino Samartzis, D.Sc., M.Sc., Dip. EBHC Harvard University and Erasmus University Francis H. Shen, M.D. University of Virginia
Bone Marrow Diseases Common bone marrow diseases are leukemias, or cancers of the white blood cells; anemias, or the inability to produce enough red blood cells; genetic disorders; environmentally provoked diseases; and the spread of other cancers such as lymphomas. They can be caused by genetic or environmental factors, or a combination of the two. Bone marrow is a fatty, spongy tissue inside some of the hollow bones of the body. Three major sites of bone marrow are the hip, sternum, and thigh bones. Bone marrow is the location of the blood stem cells, which semi-differentiate into cell types that can then become one of the several types of blood cells. The three types of blood cells are the red and white blood cells and the platelets, which are important in blood clots.
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There are five types of white blood cells; if any of these cells becomes abnormal and divides too rapidly, a leukemia results. The problem with a leukemia is that the excessive white blood cells do not serve their typical function of fighting infections; rather, they crowd the other cells, preventing growth and differentiation of functional red and white blood cells, and platelets. If the bone marrow produces too many red blood cells, the blood can become too thick to travel normally through the blood vessels. Small blood vessels can become clotted. As a result, the brain may not receive enough oxygen, causing a stroke, or portions of the heart may become oxygen starved and die, causing a heart attack. This scenario is a rare disease called polycythemia vera. When a semi-differentiated stem cell becomes abnormally prevalent over the other types, there can be too much of a particular blood cell type. As in leukemia, this blood cell type causes overcrowding in the marrow, and thus inhibits the growth and differentiation of the remaining types of blood cells. This type of disorder is called a myeloproliferative disorder. One example of a myeloproliferative disorder is thrombocythemia, or the overproduction of blood cells, primarily that of platelets. The opposite type of disorder is called myelodysplastic syndrome (MDS). In MDS, not enough of a certain type of blood cell is made. If too few red blood cells are produced, the result is anemia. If too few white blood cells are made, infections could result due to the reduced protection from the diminished white blood cells. If too few platelets are made, bleeding disorders such as hemorrhaging or excessive nosebleeds may result because the body is unable to form sufficient blood clots. In the case of too few white blood cells, symptoms of leukemia may also result. In fact, unchecked MDS often progresses into acute myeloid leukemia. A distinct disorder resulting in too few red blood cells is aplastic anemia. In this case, not enough red blood cell progenitor cells are developed in the marrow. The cause of this under development may be an injury to the bone marrow, an alteration in the bone marrow environment that is hostile to red blood cell precursors, or a genetic disorder. Sometimes the cause is human parvovirus. In many cases, the cause is unknown. Other anemias include the type due to improperly shaped red blood cells owing to a lack of iron
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in the diet or poor iron absorption, or a generalized low red blood cell count due to a kidney disorder. The kidneys produce erythropoietin, a chemical that stimulates red blood cell differentiation. If as the result of a renal disorder the kidneys produce an insufficient amount of erythropoietin, an anemia may be a secondary result. Another bone marrow disorder is primary systemic amyloidosis (PSA). PSA is the most common type of amyloidosis. An amyloidosis occurs when amyloid proteins are not broken down and therefore build up in the body. It is potentially fatal because the buildup of proteins can interrupt the normal function of the affected organ. Amyloidoses are classified by the origin of the amyloid proteins that build up. PSA results from the bone marrow making antibodies that cannot be normally broken down once they have served their immune function. As a result, the bloodstream becomes flooded with antibodies that can then deposit as amyloids in other tissues. It is typically older patients who suddenly develop myelofibrosis, a disease with no known risk factors or causes, and no definite cures. For an idiopathic reason, cells in the bone marrow begin to die, causing scarring of the marrow and poor blood cell production. There are treatments, but the disease gets progressively worse. Some bone marrow diseases can be treated with medication; others may require a blood transfusion. In some cases, a bone marrow transplant is necessary. A bone marrow transplant is a painful process, for both the donor and recipient, so it is a final option. The donor is often a family member but may be an unrelated person. Some cancer patients undergoing intensive chemotherapy against rapidly dividing cells may develop ill or dying blood stem cells as a side effect. It is possible for these patients to donate marrow that will then be transplanted back into the same patient after the treatment. SEE ALSO: Anemia; Blood/Blood Transfusion; Bone Can-
cer; Bone Diseases; Bone Health; Bone Mass Density; Bone Mineral Density; Connective Tissue Disorders; Nutrition; Vitamin and Mineral Supplements. Bibliography. Peter Beighton, ed., McKusick’s Heritable
Disorders of Connective Tissue (C.V. Mosby, 1993); Diane C. Farhi, et al., Pathology of Bone Marrow and Blood Cells
(Lippincott Williams & Wilkins, 2004); Attilio Orazi, Dennis P. O’Malley, and Daniel A. Arber, Illustrated Pathology of the Bone Marrow (Cambridge University Press, 2006); Alberto S. Pappo, ed., Pediatric Bone and Soft Tissue Sarcomas (Pediatric Oncology) (Springer, 2005); Lila Penchansky, Pediatric Bone Marrow (Springer, 2004). Claudia Winograd University of Illinois at Urbana-Champaign
Bone Mass Density Bone mass density refers to the absolute amount of bone as measured by bone mineral density (BMD) testing. BMD generally correlates with bone strength and its ability to bear weight. The BMD is measured with a dual energy X-ray absorptiometry test (DEXA scan). By measuring BMD, it is possible to predict fracture risk in the same manner that measuring blood pressure can help predict the risk of stroke. Reduced bone mass is the most common clinical skeletal disorder. An age-related decline in bone mass begins around age 35 and accelerates in women after menopause. Loss of bone mass is due to osteopenia or, if more severe, to osteoporosis. Bone density in any adult that is between 1 and 2.5 standard deviations below the mean is defined as osteopenia, and a value more than 2.5 standard deviations below the mean is defined as osteoporosis and is associated with skeletal fragility; this level is considered to represent the fracture threshold. These values are referred to as T-scores (number of standard deviations above or below the mean value in young adults of the same sex and race). The purpose of BMD testing is to help predict the risk of future fracture and aid a decision as to whether prescription medicine therapy is needed to help reduce the risk of fracture. The risk of fractures of the hip, wrist, upper arm, and vertebrae increases for both men and women with decreased bone density. Lifestyle changes, calcium and vitamin D supplementation, and pharmacological treatments for low bone density decrease the risk of fractures. Low bone mineral density appears to predict fractures in all ethnic groups. However, the differences in fracture risk across different ethnic groups cannot be
explained on the basis of differences in bone mineral density alone. The risk of hip fractures is considerably lower in African-American women than in Caucasians. A number of factors may contribute to the relative protection against fracture, including higher peak bone mass and slower rate of bone loss after menopause. However, studies have reported that after adjusting for body size and other covariates, bone density–specific fracture risk is still lower in African-American women when compared to Caucasian women. Asian women also appear to have a lower risk of fracture than Caucasian women. Bone mineral density is lower in Asian than in Caucasian women, but this is due to their smaller body habitus. In studies adjusted for other factors known to affect bone density, bone mass density in women under 70 kilograms was similar for African-American, Japanese, and Chinese women, but lower in Caucasians. Asian women were also found to have a lower bone density–specific fracture risk than Caucasian women. At present, the National Osteoporosis Foundation and the U.S. Preventive Services Task Force, the issuers of the two most prominent guidelines about BMD testing, have recommended that all women over the age of 65 be tested, regardless of risk factors. The guidelines differ a little bit regarding younger women because of the lack of reliable scientific information. In addition, there are several medications and medical conditions that a doctor reviews to determine if a person is at an especially high risk for fracture. The attainment of a higher peak bone density has an important role in the prevention of osteoporosis later in life. Genetic factors and race/ethnicity have a strong influence on peak bone density. Physiological, environmental, and modifiable lifestyle factors can also play a significant role. These factors include adequate nutrition and body weight, exposure to sex hormones at puberty, and level of physical activity, and are not only important for the acquisition of maximal bone mass but also for its maintenance throughout life. SEE ALSO: Bone Cancer; Bone Diseases; Bone Health;
Bone Marrow Diseases; Bone Mineral Density; Osteoporosis. BIBLIOGRAPHY. L.K. Bachrach, “Osteoporosis and Mea-
surement of Bone Mass in Children and Adolescents,” Endo-
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crinology and Metabolism Clinics of North America (v.34/3, 2005); Ronald G. Grainger, David J. Allison, and Adrian K. Dixon, eds., “Dual Energy X-Ray Absorptiometry (DXA),” Grainger & Allison’s Diagnostic Radiology: A Textbook of Medical Imaging, 4th ed. (Churchill Livingstone, 2001). Barkha Gurbani UCLA School Of Medicine
Bone Mineral Density Bone mineral density is an estimate of bone mass. Bone mineral density tests, such as dual-energy Xray absorptiometry (DEXA) scans, can be used to estimate the mineral content of bone, and thus its strength and risk for fracture. Osteoporosis is an agerelated disease, more prevalent in females, resulting in loss of bone mineral density and associated morbidities, such as fractures. DEXA scan is an accurate and effective method for osteoporosis screening. Early identification of individuals at risk for osteoporosis will allow for therapeutic intervention, which can reduce the risk of osteoporotic-related fractures. Bone is a dynamic organ and a rich mineral reservoir. It is mainly composed of calcium and phosphorous, and is constantly being broken down and rebuilt. A normal individual has a healthy equilibrium between these two opposing processes. When the mineral content of bone is taken away faster than it is added, the bone becomes thin, weak, and prone to fracture. Bone mineral density tests specifically measure the mineral content of the bone and estimate the risk for fracture. There are several types of clinical tests that are used to determine bone mineral density. Such tests include the use of single-photon absorptiometry, dual-photon absorptiometry, ultrasound, and quantitative computed tomography. However, the most reliable and accurate test method of predicting fracture risk, while using the least radiation as possible, is the DEXA scan. A DEXA scan is used to establish the diagnosis of osteoporosis, which places individuals at risk for devastating fractures. In order to determine if a person has osteoporosis, a DEXA scan is performed on the individual’s wrists, spine, and hips. The results are
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then compared to normal cohorts and expressed in two numbers. The Z-score is derived by comparing a person’s DEXA scan result to a person of similar age, sex, and race. The T-score is derived from comparing a person’s DEXA scan result to that of healthy young adult women. A negative number in either score indicates osteopenia. According to World Health Organization guidelines, a T-score of minus 2.5 establishes the diagnosis of osteoporosis. An integral part of preventing the morbidities associated with osteoporosis is early patient screening and intervention. General guidelines recommend obtaining a bone mineral density test in all women aged 65 and older, regardless of the presence of any other risk factors for osteoporosis. Younger postmenopausal women who present with one or more risk factors for osteoporosis are also recommended to have DEXA scan screening. Risk factors for osteoporosis include a strong family history of osteoporosis, smoking, early estrogen deficiency, use of medications such as steroids and anticonvulsants, and presence of endocrine abnormalities, such as hyperthyroidism. In addition, postmenopausal women who present with fractures are also recommended to obtain a DEXA scan to confirm the diagnosis of osteoporosis and determine the severity of bone loss. By identifying individuals at greatest risk for osteoporosis and employing early intervention, such as lifestyle modification and medications, the risk of hip and vertebral fractures has been shown to be reduced by up to 50 percent. SEE ALSO: Bone Diseases; Bone Health; Bone Mass Den-
sity; National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS); Osteogenesis Imperfecta; Osteoporosis. BIBLIOGRAPHY. John D. Heckman, Animesh Agarwal,
and Robert C. Schenck, Current Orthopedic Diagnosis and Treatment (McGraw-Hill, 2006); National Osteoporosis Foundation, www.nof.org (cited December 2006). Shen-Ying (Richard) Ma, M.D. University of Virginia Dino Samartzis, D.Sc., M.Sc., Dip. EBHC Harvard University and Erasmus University Francis H. Shen, M.D. University of Virginia
Bosnia and Herzegovina Bosnia and Herzegovina is located in the Balkans, with a western coast on the Adriatic Sea. It shares borders with Montenegro, Croatia, and Serbia. Bosnia and Herzegovina was one of the countries to emerge from the disintegration of Yugoslavia in the 1990s. Three main ethnic groups now uneasily share power in the new country: Bosniaks, Croats, and Serbs. Bosniaks are primarily Sunni Muslim, Croats are Roman Catholic, and Serbs are Orthodox Christians. The republic also has three official languages. The population is 4,552,000 and growing at 1 percent annually. The birth rate and death rate are about equal, at 8.8 and 8.42 per 1,000 population, respectively. Growth comes mostly from migration, with 9.65 migrants per 1,000. Median age is 38.9 years. Life expectancy is 74.5 years for males and 82.03 for females. The economy has not yet rebounded from the war years, and Bosnia and Herzegovina is the second-poorest of the former Yugoslav states, with gross national income of U.S. $2,440 and 45.5 percent unemployment. The risk of communicable disease is low, and does not rank among the 10 leading causes of death within the republic. A 2003 report looked at 42,614 reported cases of communicable disease and found that the vast majority were influenza, chicken pox, gastroenteritis, and scabies. There has been a recurrent problem with Q fever (coxiella brunetii infection), a zoonotic illness affecting both livestock and humans in rural areas. Sanitation within the country is good, with 97 percent using clean water and 99 percent using sanitary facilities. AIDS affects less than 0.1 percent of the adult population, with between 500 to 1,000 infections and a small number of AIDS-related deaths. In cases where the means of transmission is known, 54 percent came from heterosexual contact, 15 percent came from homosexual contact, and 14 percent came from IV drug use. While AIDS is clearly not widespread at the present time, there is the risk of a much wider outbreak. The level of prevention education is low, and there has been a rapid increase in drug abuse in recent years. Noncommunicable disease is also expected to rise as the population ages. Recent lifestyle surveys found that 54.2 percent of males are regular consumers of alcohol and 49.3 percent use tobacco. Seventytwo percent of men and 80.5 percent of women get
Botswana
limited physical exercise; 25.2 percent of women are overweight, and 29.8 percent are smokers. The leading causes of mortality in Bosnia and Herzegovina are cerebrovascular disease, heart disease, respiratory cancers, diabetes, colon cancers, liver cancer, cirrhosis of the liver, and suicide. Children’s health has returned to prewar standards. Mortality rates are low, with 13 deaths per 1,000 in infants younger than 1, and 15 deaths per 1,000 for those between the ages of 1 and 5. Ninety-three percent attend school. Some serious problems remain, including residual ethnic tension from before the war and the continuing disenfranchisement of Roma (gypsy) children from both education and healthcare. There are also the deadly leftovers of the war: More than one million landmines and unexploded pieces of ordinance litter the countryside. More than 15,000 people are injured or killed by landmines each year, a quarter of them children. Women’s reproductive health is generally good. The fertility rate is 1.23 children per women. All women receive prenatal care and deliver with the help of trained assistants. Maternal mortality is 31 deaths per 100,000 live births. Bosnia and Herzegovina has a large medical community with all the major specialties well represented. There are 87 health centers and a large number of health stations at the community level. There are also five clinical centers, 23 general acute hospitals, seven specialized hospitals, and 12 district hospitals. The country devotes 8.3 percent of the gross domestic product to healthcare, and spends about U.S. $197 per capita. However, a 2001 report by the United Nations notes that the healthcare system is poorly organized and is currently not capable of meeting the needs of its citizens, to the point where minor health complaints are allowed to become lingering, chronic, and sometimes life-threatening health problems. See also: Croatia; Healthcare, Europe; Serbia and Mon-
tenegro.
BIBLIOGRAPHY. Central Intelligence Agency, “Bosnia and
Herzegovina,” World Factbook, www.cia.gov (cited June 2007); Institute for War and Peace Reporting, “Bosnia Struggles with Wave of Drug Addiction,” iwpr.net (cited June 2007); Joint United Nations Programme on HIV/ AIDS (UNAIDS), “Bosnia and Herzegovina,” www.unaids
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.org (cited June 2007); World Health Organization, “Health Care Systems in Transition,” www.euro.who.int (cited June 2007); World Health Organization, “Mortality in Bosnia and Herzegovina,” www.who.int (cited June 2007); World Health Organization, “WHO Global InfoBase,” www.who .int (cited June 2007). Heather K. Michon Independent Scholar
Botswana Botswana is a landlocked country in southern Africa, bounded by South Africa, Zambia, Zimbabwe, and Namibia. The former British protectorate of Bechuananland emerged as an independent nation in 1966 and quickly became one of the most progressive countries in Africa. With an economic growth rate averaging nine percent a year since 1966, Botswana climbed from poverty to a middle-income state by the 1990s. At the same time, the country has been virtually crippled by the AIDS epidemic, with one in three Batswana infected. The population is 1,816,000 and growing at 1.5 percent annually. Growth is driven by a high birth rate at 23.17 per 1,000 population and an influx of migrants, mainly from nearby Zimbabwe. The death rate is also high at 13.63 per 1,000 population. Median age is 20.9. Life expectancy, which in the 1980s had reached an average of 64 years, has dropped to 51.55 years for males and 49.58 years for females, and is expected to decline even further in the coming years. Over half of all Batswana live in urban areas. Gross national income is U.S. $5,180, with 24 percent living on U.S. $1 a day or less. The unemployment rate is 24 percent. Communicable diseases are responsible for upward of 77 percent of all deaths in Botswana. Malaria is endemic in the northern regions. While sanitation in the urban areas is fairly good, with 100 percent access to clean water and 57 percent to sanitary waste facilities, it is far from adequate in rural areas, where only 90 percent have safe water and 23 percent use sanitary facilities. Waterborne and foodborne illnesses are common. Severe flooding in 2006 set off an epidemic of diarrheal infections. Tuberculosis is also a growing problem, with 553 cases per 100,000 people.
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Nothing has had as great an impact on health in Botswana as the AIDS epidemic. The adult prevalence rate is 24 percent, giving the country the second-highest prevalence in the world, next to Swaziland. There are an estimated 270,000 Batswana living with the virus today, including 140,000 women and 14,000 children. AIDS-related deaths exceed 18,000. AIDS cases fill 60 percent of the country’s hospital beds. The country has worked hard to check the growth of the disease and deal with those afflicted. About 85 percent of patients in need receive antiretroviral drug therapy. Educational programs also seem to be paying off: In a 2006 Joint United Nations Programme on HIV/AIDS survey, 88 percent of men and 75 percent of women said they had used a condom during their last sexual encounter. AIDS has created 120,000 orphans, a population that will only grow in the coming years. Infant and child mortality has risen since 1990, with 87 deaths per 1,000 in infants younger than 1 and 120 deaths per 1,000 in children aged 1–5. Most children do receive routine immunization and the chance to go to school. Botswana earmarks 6.4 percent of its Gross Domestic Product on healthcare, spending about U.S. $206 per capita. There are 22 hospital beds per 10,000 people, and a wide variety of health facilities spread across the country. The medical community is small, with 715 physicians and 4,753 nurses in 2004. The government recognizes the need to recruit more medical staff, but is somewhat hampered by the lack of a national medical college. See also: AIDS; Healthcare, Africa. Bibliography. Central Intelligence Agency, “Botswana,”
World Factbook. www.cia.gov (cited June 2007); Joint United Nations Programme on HIV/AIDS (UNAIDS), “Botswana,” www.unaids.org (cited June 2007); Researchafrica. rti.org, “Sub-Saharan Africa—Botswana,” researchafrica. rti.org (cited June 2007); United Nations Children’s Fund (UNICEF), “Botswana—Statistics,” www.unicef.org (cited June 2007); World Health Organization, “WHO Global InfoBase,” www.who.int (cited June 2007); World Health Organization, “A Guide to Statistical Information at WHO, 2007,” www.who.int (cited June 2007). Heather K. Michon Independent Scholar
Botulism Botulism is a bacterial infection that affects the nervous system. There are between 70 and 100 cases of botulism per year in the United States. The toxin formed by the bacteria is fatal at very low doses, and can therefore be used as a biological weapon. The causative organism of botulism is Clostridium botulinum, an anaerobic, spore forming, gram-positive bacteria. Bacterial spores are found in soil, dust, and marine sediment (both freshwater and saltwater). Many subtypes of the bacterium exist, but only A, B, E, or F can cause the botulism infection in humans. The bacterium produces a toxin that affects muscle contraction. Infection occurs through ingestion of contaminated foods (which contain preformed toxin), through open wounds (e.g., through subcutaneous injections of heroin, also known as “skin popping”), and via bacterial colonization of the intestinal tract of infants. Honey should not be fed to infants under 12 months old, since it has been associated with intestinal botulism infections. Home canning is also associated with infection due to poor hygiene during the canning process. According to the Center for Disease Control and Prevention (CDC), of the 100 U.S. cases reported per year, over 70 percent are the infant form, while the rest are either foodborne or via wounds. Symptoms of botulism arise one to six days after infection. The botulism toxin prevents muscles from contracting, causing relaxed paralyzed muscles, a condition known as “flaccid paralysis.” This effect is the opposite of that seen in the stiff muscles and “tetany” seen in tetanus infections. Severe infections are identified by a symmetric, descending (beginning at the head and spreading down to include the chest and leg muscles) paralysis, and cranial nerve (which affects hearing, smell, and facial and eye muscles) abnormalities. If the paralysis descends to include respiratory muscles, patients may need to be placed on a respirator for mechanical ventilation. Other symptoms include double vision, blurry vision, drooping eyelids, dry mouth, weakness, lethargy, constipation, and dilated or unreactive pupils. Infants often present with symptoms of weakness, floppy limbs, lethargy, and constipation. If the diagnosis of botulism infection is suspected, it can be confirmed with a laboratory blood test for the neurotoxin. The disease is prevented via hygienic food storage, thorough cooking of food to kill spores prior to
Bovine Spongiform Encephalopathy (BSE)
eating, and avoiding honey for infants. Botulism is treated with a botulism antitoxin that neutralizes the effects of the botulism toxin. Adult patients are also often treated with antibiotics. A vaccine is currently available for individuals with a known exposure to botulism and it may be useful in cases where botulism is used as a biological weapon. Botulism toxin is also used as an injection for its paralytic effects to treat certain facial neuromuscular disorders and for cosmetic purposes. SEE ALSO: Biological and Chemical Weapons; Center
for Food Safety and Applied Nutrition (CFSAN); Centers for Disease Control and Prevention (CDC); Food Contamination/Poisoning; Food Safety; Foodborne Diseases; Tetanus. BIBLIOGRAPHY. Elias Abrutyn, “Botulism,” in Harrison’s
Principles of Internal Medicine, 15th ed. (McGraw-Hill Professional, 2001); Peter P. Taillac, “Botulism,” www. emedicine.com (cited June 2006); Centers for Disease Control and Prevention, www.cdc.gov (cited June 2006); World Health Organization, www.who.int (cited June 2006). Amit Chandra, M.D., M.Sc. NY Hospital, Queens
Bovine Spongiform Encephalopathy (BSE) Bovine spongiform encephalopathy (BSE) is popularly known as “mad cow disease.” It is a neurodegenerative disease found in cattle that is fatal to cattle and to humans if it is transmitted to them. BSE is one of a number of forms of transmissible spongiform encephalopathies (TSEs), which are a cluster of rare degenerative brain disorders. TSEs are also known as “prion” diseases, which leave tiny holes in victims’ brains that give the brains a “spongy” appearance. Prion is short for proteinaceous infectious particle. The particle is a protein that occurs in a harmless normal form in the body’s cells. The most widely accepted current theory is that a normal protein changes into a pathogenic form that then damages the central nervous system of cattle. Prions seem to be the cause in other forms of transmissible spongiform encephalopathy.
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Mad cow disease in humans has been approached as a variant of Creutzfeld-Jakob disease (CJD), another human TSE. The new TSE (designated as vCJD to mark it as a variant CJD) has symptoms that are different from classic CJD. Also, it afflicts much younger people. Strong epidemiologic and laboratory evidence suggests a causal link between vCJD and BSE. The incubation time for vCJD and BSE are also consistent. The new disease of vCJD was first reported during a BSE outbreak in the British Isles, and it appears likely that vCJD is caused by eating food from cattle that are contaminated with BSE agents. Emergence and Transmission The first known cases of BSE occurred in the 1970s, and two cases of BSE were also identified in 1986. These cases probably originated from the feeding of cattle a protein feed made from scrapie-infected sheep products that was believed to be safe. The BSE epidemic in cattle in Great Britain peaked in January 1993. At that time there were 1,000 new cases per week. By the end of 2005, over 184,000 cases of BSE had been confirmed in the United Kingdom. The cases of BSE came from over 35,000 herds. At the end of May 2007, 14 cases of BSE in animals had been identified in north America. Eleven of the cases were in Canada and three were identified in the United States. The first U.S. case was identified on December 23, 2003, in Washington state. Tracing the ear-tag identification number of the BSE victim showed that it had been imported from Canada in 2001. In 2006, the United States Department of Agriculture announced the discovery of a BSE in a 10year-old cow in Alabama. Outbreaks of BSE or vCJD in humans since 1995 include 147 human victims in the United Kingdom, seven in France, and one each in Ireland, Israel, Italy and Japan. BSE and other TSEs are not contagious; however, they are transmissible, even through ocular, oronasal, or iatrogenic exposure. TSEs are transmissible because the deadly prion protein is acquired from an alien source. Researchers are examining the possibility that TSEs are also infectious. It is likely that human victims had been eating the infected meat for some time. Also, in Great Britain several BSE victims were apparently the recipients of
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blood transfusions from donors who did not know they were infected with the BSE agent. Symptoms and Diagnosis In cattle symptoms of BVE are neurological and physiological. Symptoms in cattle include change in attitude and behavior. Some or all of these symptoms may be manifest: apprehension, increased startling, depression, hyperesthesia or hyperreflexia. Gradually, the animal’s movements become more erratic. Uncoordinated movements related to degeneration in the brain cause the animal to becomes uncoordinated and to have trouble walking or standing. The movements are adventitial movements with muscle fasciculations, tremor, and myoclonus. The gait becomes affected by ataxia with hypermetria. Other symptoms include pruritus, which is intense itching, often around the anus, with itching sensitivity and fecal seepage occurring. Actions to scratch the itching can cause injuries. Weight loss occurs while the appetite remains, and rumination is reduced. Bradycardia (low heart beat) and altered heart rhythms (noncardiac arrhythmia) may be present. In dairy cows milk production decreases. The progression in symptoms may take from two weeks to six months once the symptoms of the disease are visible. The development of BSE may be slow: It may take from two to eight years for the disease to be manifest once it has been contracted. The disease terminates in death. Euthanasia on humane grounds is usually applied—not only to a single victim but at times to larger herds. For human victims of BSE, the symptoms are similar to those in cattle. Neurological damage in the brain causes psychological symptoms to be manifest. These usually progress from apparently nonspecific psychiatric symptoms of anxiety, insomnia, memory loss, depression, and withdrawal to more psychotic symptoms. The symptoms are only apparent because the brain is actually being destroyed by the disease. Physiological symptoms develop in humans as the disease progresses into increasingly dysfunctional neurological problems. As the brain is destroyed muscle control decreases so that muscle spasms and lack of muscle control give the victim an unsteady gait. Eventually the victim is rendered helpless and death ensues. Diagnosis can be very difficult because there is currently no definitive test. The use of bioassay brain
material that is then used to inoculate mice can provide a method for detection. However, the test takes 300 days to be completed and is therefore impractical. The use of serological tests has been found impractical because no immune responses have been found to date in either BSE or other TSEs. Postmortem examination of the clinically affected brain typically shows changes in the brain or the brain stem. The brain will show symmetrical spongiform changes of grey matter. Immunohistochemical tests usually show the specific prion of the disease. Fibrils can be seen with an electron microscope. Other aspects of the damage caused by the disease may be manifest, such as isoforms of prion protein (PrP) in extracts of fresh or frozen brain. Other Forms of TSE Besides BSE there are other forms of TSEs in animals. Sheep and goats are prone to the fatal degenerative disease known as scrapie. Since TSEs are transmissible, infected animals can spread the disease to other flocks if they are sold rather than destroyed. The disease causes loss of production and it prevents the sale of semen, embryos, or breeding stock to other countries. In the late 1960s, it was discovered that elk and deer can be afflicted with TSE. Chronic wasting disease (CWD) is similar to mad cow disease, but affects deer and elk populations. Herds in Colorado and Wyoming have been affected, and the disease is spreading. Feline spongiform encephalopathy (FSE) was found in cats in Great Britain in 1990. Since then, it has been reported in continental Europe as well. Transmissible mink encephalopathy (TME), which affects the central nervous system, was first diagnosed in 1947 in ranch-raised minks in the United States. TME has since been reported in Russia, Canada, Finland, and Germany. There are many forms of TSEs in humans, including CJD, kuru (“laughing sickness”), fatal familial insomnia (FFI), and Gerstmann-Straussler-Scheinker disease (GSS). Kuru was first identified in Papua New Guinea among the Fore people. With a Stone Age culture, they practiced ritualistic cannibalism. At funerary feasts they would eat the brains of deceased relatives, allowing infectious crystal protein to invade human cells. After the practice was outlawed in the 1970s, kuru gradually disappeared.
Brain Cancer
FFI is symptomatically similar to CJD. It is an hereditary prion disease that disrupts sleep creating insomnia that lasts until death. The disease is due to a missense mutation at codon 178 of the prion protein gene on chromosome 20. The disease runs in families and is fatal in seven to 36 months after the beginning of symptoms. GSS is a TSE that is very rare, and most cases have been inherited. It usually strikes between ages 35 to 55. As the disease progresses, symptoms resemble Parkinson’s disease with dysarthria, nystagmus, spasticity, and disturbances in vision or deafness. Treatment and Prevention There are no known effective treatments for TSEs. The National Institute of Neurological Disorders and Stroke (NINDS) and other organizations are working to find cures. Because of the lack of effective diagnostic tests or treatments, the common method for dealing with animals is for them to be killed by lethal injection. The affected victims are slaughtered and other herd members are usually destroyed as well. Agricultural authorities in many countries have taken steps to prevent the use of infected cow parts in feed or in products used by humans. In countries with modern healthcare systems, suspected or documented cases are traced to their origins. Steps to safeguard the importation of other live ruminant species are taken. Policies and procedures are also put in place to govern the importation of embryos. Medical workers handing tissues from BSE cases, even if only suspected, are required to wear appropriate protective gear. Strict protocols are followed to prevent exposure to prions, which are very resistant to physical or chemical treatments. The appearance of cases of TSEs has produced political controversy over the safety of the food supply, blood supply, and medical procedures. The general public and the media have been fairly successful in pushing governments to exercise due regard for public safety from any threat connected with TSEs. See also: Center for Food Safety and Applied Nutri-
tion (CFSAN); Centers for Disease Control and Prevention (CDC); Food Contamination/Poisoning; Food Safety; Foodborne Diseases; Missense Mutation. Bibliography. Colm A. Kelleher, Brain Trust: The Hidden
Connection between Mad Cow and Misdiagnosed Alzheim-
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er’s Disease (Pocket Books, 2004); Brian K. Nunnally and Ira S. Krull, eds., Prions and Mad Cow Disease (Marcel Dekker, 2003); Richard Packer, Politics of BSE (Palgrave Macmillan, 2006); Stanley B. Prusiner, Prion Biology and Disease (Cold Spring Harbor Laboratory Press, 2004); Scott C. Ratzan, ed., Mad Cow Crisis: Health and the Public Good (New York University Press, 1998); Tom Ridgway, Mad Cow Disease: Bovine Spongiform Encephalopathy (BSE) (Rosen Publishing Group, 2002); John R. Romans, William J. Costello, and Wendell C. Carlson, Meat We Eat (Prentice-Hall, 2000); John Spriggs and Grant Isaac, Food Safety and International Competitiveness: The Case of Beef (Oxford University Press, 2001); Patrick Van Zwanenburg and Erik Millstone, BSE: Risk, Science and Governance (Oxford University Press, 2005). Andrew J. Waskey Dalton State College
Brain Cancer In the spectrum of all cancers, brain cancer is a unique entity because it affects people of all ages— brain tumors are the most common cancer of children after leukemias—and has relatively few known causes and risk factors. Brain cancer is also interesting because there are more than 20 different types of primary brain tumors, and the brain is a common location for metastatic cancers from other organs. The most common metastases to the brain are lung and breast cancers. The most common symptom experienced by people with brain tumors is progressive neurologic deficit, usually weakness. Headaches are the second most common symptom of brain tumors and occur for five different reasons: 1.) increased intracranial pressure (ICP), 2.) high blood pressure secondary to the elevated ICP, 3.) invasion or compression of pain-sensitive structures (e.g., blood vessels) by the tumor, 4.) secondary to difficulty with vision, and 5.) psychological secondary to other symptoms caused by the tumor. Other symptoms may depend on the location of the tumor. If the tumor is supratentorial (above the tentorium cerebelli, the sheet of dura mater that separates the inferior cerebellum from the superior cerebral cortex), other symptoms may include seizures and mental status changes. Infratentorial tumors, on the
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other hand, may have symptoms of hydrocephalus due to obstruction of cerebrospinal fluid flow. Types of Brain Tumors Acoustic neuromas, also known as vestibular schwannomas, are a common brain tumor, comprising approximately 10 percent of primary brain tumors. Acoustic neuromas arise from the vestibular division of cranial nerve VIII (vestibulocochlear nerve). Because this nerve is responsible for hearing function, patients with acoustic neuromas present with symptoms of hearing loss, tinnitus (ringing in the ears), and imbalance. The treatment of acoustic neuroma involves surgery and/or radiation therapy. Common complications after surgery include cranial nerve and brainstem dysfunction, as well as cerebrospinal fluid (CSF) leak. Astrocytomas are the most common primary brain tumor, and there are many different types of astrocytomas. The World Health Organization (WHO) classifies astrocytomas with a grading system where increased grade equals increased malignancy. Grade I includes pilocytic astrocytoma, grade II low-grade astrocytomas, grade III anaplastic astrocytomas, and grade IV glioblastoma multiforme (GBM). The most common and malignant astrocytoma is GBM; typical survival in patients diagnosed with GBM is one year. Another interesting clinical entity is brain stem glioma. Brain stem gliomas tend to occur in children and adolescents, and patients typically present cranial nerve palsies, gait abnormalities, and weakness.
A positron emission tomography (PET) scan of a 62-year-old man with a brain tumor classified as a grade III astrocytoma.
Brain stem gliomas are very malignant and are associated with poor prognosis; typical survival is from 6 to 12 months. The choroid plexus is a leafy structure present in the brain’s ventricles that produces CSF. Choroid plexus tumors account for just 1 percent of brain tumors and are primarily a disease of childhood, with 70 percent of patients under the age of 2 years. Some are even found in neonates, suggesting that choroid plexus tumors can also be a congenital condition. These tumors are usually benign but can also be malignant. Because choroid plexus produces CSF, patients usually present with symptoms of hydrocephalus: headache, nausea, vomiting, large head, and so forth. The only option for treatment is surgery. Central nervous system (CNS) lymphoma may occur primarily, originating in the brain, or secondarily, originating outside the brain and metastasizing to it. Lymphoma is very common and the fifth leading cause of cancer deaths in the United States. Primary CNS lymphoma (PCNSL) is rare, making up only 1 to 2 percent of brain tumors and a similar percentage of lymphoma cases. Although PCNSL is rare, the incidence is rising because of the predilection of AIDS and transplant patients to develop lymphoma. Males are affected slightly more often than females, and the average age at diagnosis is about 50 years old. The most commonly affected locations in the brain are the frontal lobes and the cerebellum. Symptoms are frequently due to spinal cord compression (changes in strength and sensation) and carcinomatous meningitis (multiple cranial nerve deficits). There are three broad conditions that increase the risk of developing PCNSL. First, collagen vascular diseases such as systemic lupus erythematosus, Sjogren’s syndrome, and rheumatoid arthritis carry a higher incidence of PCNSL than the general population. The second group of patients is immunosuppressed patients, such as the elderly or people with AIDS. Last, infection with Epstein-Barr virus (EBV) has been detected in every case of PCNSL. The treatment of CNS lymphoma includes radiation therapy and chemotherapy. Unfortunately, the disease carries a very poor prognosis. Without treatment, death usually occurs within two to three months; with radiation alone, average survival is 10 months. Combining radiotherapy with chemotherapy offers the best treatment and greatest chances for longer survival.
Colloid cysts are a type of glioma that are benign, slow growing, and comprise approximately two percent of all gliomas and 1 percent of all brain tumors. These tumors typically arise in the third ventricle of the brain, where they block CSF flow and cause symptoms of hydrocephalus. If the cyst causes sudden blockage, it can lead to sudden death. The most common symptoms due to colloid cysts are headache, gait disturbance, and altered mental status. As with most tumors, the treatment of colloid cysts is surgical. Craniopharyngiomas are benign brain tumors that arise from a specific portion of the pituitary gland. They make up a small percentage (three to four percent) of all brain tumors. Half of the time, craniopharyngiomas occur in children and the peak incidence is between age 5–10 years. Treatment is surgical, but because of the location of these tumors, the operation is quite difficult and recurrences occur frequently. Ependymomas arise from ependymal cells which line the brain’s ventricles. These tumors can also occur in the spine. Seventy percent of ependymomas occur in children, comprising 10 percent of all pediatric brain tumors. When occurring intracranially, the average age of diagnosis in all ependymoma patients is approximately 17 years. Intracranial ependymomas are typically benign tumors that arise in the fourth ventricle of the brain. Symptoms commonly include headache, nausea, vomiting, gait imbalance, and vertigo. The treatment of ependymoma is surgical resection followed by radiation therapy. This treatment plan results in a five-year survival rate of 40 percent; the younger the patient is, the worse the prognosis. Epidermoid cysts are benign tumors that make up 1 percent of brain tumors. They typically arise in the cerebellopontine angle (the junction of the cerebellum and pons) or fourth ventricle of the brain from ectodermal remnants of development. If the cyst ruptures, a condition called aseptic meningitis may result with symptoms such as fever, headache, and stiff neck. Treatment is surgical. Ganglioglioma is a very rare and slow-growing tumor seen mainly in children and young adults; the peak age of occurrence is 11 years. The tumor can arise anywhere in the nervous system. Patients typically present with seizures that are refractory to treatment with medicines. The treatment of this type of brain tumor is surgical, and the prognosis is good.
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Hemangioblastomas (HGB) are the most common tumors that arise in the adult posterior fossa (the posterior-inferior part of the brain, i.e., the cerebellar area). These tumors are benign, and 20 percent arise as part of von Hippel-Lindau disease (VHL). In general, HGB account for 1 to 2 percent of brain tumors, and approximately 10 percent of posterior fossa tumors. The most common location of HGB is the cerebellum. Patients become symptomatic usually in their 20s if they have VHL and their 30s if the HGB is sporadic. Symptoms include headache, nausea, vomiting, and cerebellar findings (i.e., incoordination). Treatment is surgical. The most common low-grade gliomas are infiltrating astrocytomas (WHO grade 2), oligodendrogliomas, and oligoastrocytomas. Low-grade gliomas usually occur in children or young adults and typically present clinically with seizures. Definitive diagnosis is made with biopsy. Treatment is surgical; when complete excision is not accomplished, chemotherapy is the next line of treatment. Meningiomas account for 15 to 20 percent of all primary brain tumors. Meningiomas arise from the arachnoid (one of the thin layers covering the brain) and are typically benign and slow growing. The most common location of meningiomas is parasagittal, that is, along the midline that separates the two cerebral hemispheres. The average age of affected patients is 45 years and there is a slightly higher prevalence among females. Meningiomas are also a common finding in patients with neurofibromatosis. Surgery is usually curative if the tumor is completely removed, but recurrence is common: 10 to 15 percent in cases where the entire tumor is removed and 30 percent when total removal is not accomplished. The prognosis, however, is excellent with a five-year survival exceeding 90 percent. Oligodendrogliomas (ODG) are mainly a tumor of adulthood, as the average age of affected patients is 40 years. They are relatively common and make up one-quarter to one-third of glial tumors; there is a slight predilection for development of ODG in males. ODGs commonly grow in the frontal lobes of the brain, and patients frequently present with seizures, headaches, and mental status changes. The treatment of ODG is surgery when possible and chemotherapy for all patients. The pineal region of the brain contains the pineal gland. A large variety of tumor types can arise in this
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region. In pediatric patients, the most common lesions are germinomas and astrocytomas. In adults, however, tumors in the pineal region are more likely to be meningiomas or gliomas. Other lesions include pineocytomas, chemodectomas, and choriocarcinomas, to name a few. Clinically, patients of all ages present with the symptoms of hydrocephalus, that is, headache, vomiting, lethargy, and so forth. The treatment of pineal tumors includes surgery and/or radiation. Pituitary adenomas are tumors of the pituitary gland that make up one-tenth of primary brain tumors. They affect both sexes equally and typically become symptomatic during a patient’s 20s and 30s. Symptoms of pituitary adenoma result from hormonal or mass effect. The most common hormones released by pituitary adenomas are prolactin, adrenocorticotropic hormone (ACTH), and growth hormone. Prolactinomas cause amenorrhea (no menstrual periods) and galactorrhea (breast milk discharge) in women, impotence in males, and infertility in both sexes. Pituitary adenomas that secrete ACTH cause Cushing’s disease. Growth hormone-secreting adenomas cause acromegaly in adults and gigantism in children. Excess ACTH is called hypercortisolism, and hypercortisolism caused by pituitary adenomas is called Cushing’s disease. Other causes of hypercortisolism, including lung and adrenal tumors, produce the same symptoms but are known as Cushing’s syndrome. Physical findings in patients with Cushing’s disease or syndrome include weight gain, hypertension, hyperglycemia, osteoporosis, muscle wasting, and psychiatric changes. Skin findings can include thinning, bruising, and purple stripes (striae). The treatment of pituitary tumors can consist of medicines, radiation therapy, and surgery. Primitive neuroectodermal tumors (PNET) are tumors that arise from primitive neuroectodermal cells. Although there are several different PNETs, the most important are medulloblastomas. Medulloblastomas account for one-fifth of pediatric brain tumors, and they are the most common malignant pediatric brain tumor. Most occur in the first decade of life with a twofold greater incidence in males. Medulloblastomas usually arise in the cerebellum in the vicinity of the fourth ventricle, and resultant symptoms include headache, nausea, vomiting, and ataxia. The treatment of medulloblastoma involves surgery and radia-
tion therapy, with prognosis being dependent on the extent of surgical tumor removal. SEE ALSO: Acoustic Neuroma; Brain Diseases; Breast Can-
cer; Headache and Migraine; Hydrocephalus; Lung Cancer.
Bibliography. Mark S. Greenberg, Handbook of Neuro-
surgery, 5th ed. (Thieme, 2001); Andrew H. Kaye and Edward R. Laws, Brain Tumors: An Encyclopedic Approach (Churchill Livingstone, 2001); Michael Prados, Brain Cancer (B.C. Decker, 2002); Joanna Hollenberg Sher and Donald H. Ford, Primary Intracranial Neoplasms (Spectrum, 1978); Charles B. Wilson, Craig H. Yorke Jr., and Victor A. Levin, Intracranial Malignant Growth, Primary and Metastatic (Year Book Medical, 1977). Khoi D. Than, M.D. Johns Hopkins University School of Medicine
Brain Diseases The nervous system is composed of central, peripheral, and autonomic nervous systems and is integral to the functioning of many other organ systems in the body. The brain is part of the central nervous system and is derived from neuroectoderm. Approximately 20 percent of people in the United States suffer from some sort of damage to the nervous system, and a vast number of disorders affect the nervous system. These disease states may begin in utero or develop through the course of a lifetime. Research is currently being conducted in centers across the world to find cures for these diseases. In the United States, Congress developed the National Institute of Neurological Disorders and Stroke in 1950 in an attempt to help address these problems through funding and research. Many other private and public institutions are also involved in understanding and developing treatments for these diseases. A neurogenetic disease includes any disease process that is due to a defect in one or more genes that affect the differentiation and/or function of the neuroectoderm and its derivatives. The disease may be autosomal dominant, autosomal recessive, sex-linked recessive, or of mitochondrial inheritance. Autosomal dominant disorders include Huntington’s disease, spi-
nobulbar muscular atrophy, and the autosomal dominant cerebellar ataxias. Autosomal recessive disorders of the nervous system include diseases such as Friedreich’s ataxia and Refsum disease. Sex-linked recessive disease of the nervous system include disorders such as Duchenne muscular dystrophy and adrenoleukodystrophy. Mitochondrial diseases include disorders such as neuropathy, ataxia and retinitis pigmentosa (NARP), and Leber hereditary optic neuropathy (LHON). The presentation of these diseases varies greatly depending on the gene targets, ranging from motor and sensory deficits to dementia and psychiatric symptoms. Developmental disorders affect the central nervous system as it develops. The resulting injury may be due to a disease, injury, or genetic defect and affect mental or motor disability. The developing brain in utero is subject to injury at various stages, including the following: • primary neurulation: three to four weeks gestation; • prosencephalic development: two to three months gestation; • neuronal proliferation: three to four months gestation; • neuronal migration: three to five months gestation; • organization: five months gestation to years postnatal; • myelination: birth to years postnatal. The Diagnostic and Statistical Manual of Mental Disorders, 4th edition (DSM-IV), has established three criteria for identifying an individual with a developmental disability: an IQ below 70, significant limitation in two or more areas of adaptive behavior, and evidence of the limitation occurring in childhood. The causes of developmental disorders range from genetic conditions, such as fragile X syndrome, Down syndrome, and phenylketonuria to problems during pregnancy or exposure to infectious diseases. These disorders may also be caused by environmental and social deficiencies or exposures. Developmental disorders, such as cerebral palsy, may also affect the motor systems. In the case of cerebral palsy, the individual has motor or postural abnormalities without a deficit in intelligence. Neurodegenerative diseases cause the deterioration of neurons over time. Specifically, they may affect movement and create conditions such as dementia.
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There are many causes and types of neurodegenerative diseases, ranging from deposition of elements and metabolic disorders to autoimmune disorders and diseases of unknown etiologies. The most common neurodegenerative diseases are Parkinson’s disease and Alzheimer’s disease. Parkinson’s disease is a progressive condition in which cognitive and motor abilities can be affected. It is associated with dopamine deficiency due to the degeneration of nigrostriatal neurons. Alzheimer’s disease is associated with cognitive deterioration and is caused by neuronal atrophy and the deposition of amyloid plaques and neurofibrillary tangles. Multiple sclerosis is another neurodegenerative disease. Metabolic diseases are diseases that affect the products involved in metabolism. There are many types of metabolic diseases. Their targets may include the disruption of carbohydrate (pyruvate carboxylase deficiency), amino acid (Hartnup disease), or nucleotide (Lesch-Nyhan syndrome) production or interfere with mitochondrial (Kearns-Sayre syndrome), lysosomal (Hunter disease), or peroxisomal (Zellweger syndrome) function. Metabolic diseases may also interfere with lipid storage as in Gaucher’s disease. The vast majority of metabolic disorders are inherited, but they may be acquired as well. Because metabolic diseases span a number of different organs and functions, there is a wide variety of clinical symptoms that may be associated with metabolic diseases that affect the brain. The individual may suffer from movement disorders, seizure disorders, psychoses, hallucinations, and other symptoms secondary to increased or decreased products of metabolism. Cerebrovascular disease (CVD) is any disease process that affects the blood vessels in the brain. Disease of the vasculature may result in too little or too much oxygen-rich blood flow. Most commonly, CVD results from occlusion of the vessels leading to the brain (i.e., carotid arteries). This may, in turn, lead to strokes. Stroke is the third most common cause of death in the United States. Risk factors for arterial occlusion that can be prevented include smoking cessation, lack of exercise, diet, obesity, diabetes, high blood pressure, and high cholesterol levels. There are risk factors that cannot be controlled, that is, age, gender, and ethnicity. Individuals may also suffer from hemorrhage from cerebrovascular diseases, such as arteriovenous
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malformations, aneurysms, or trauma. Bleeding into the brain can further lead to more severe complications and poor outcomes. Deficits resulting from cerebrovascular disease range from memory loss and aphasias to paralysis and paresthesias. Other cerebrovascular diseases include vascular dementia and rarer diseases such as moyamoya disease. Treatment of these conditions is based upon the severity and type of disease; however, it is important to note that maintaining adequate oxygen delivery to the tissues is necessary for survival. Convulsive disorders result from hypersynchronous discharge by cortical neurons. Seizures may have motor manifestations, such as tonic and/or clonic movements. They may also manifest in an impaired level of consciousness. There are a wide variety of causes for seizures, including perinatal injury, infection, metabolic or congenital disturbances, alcoholism, drug withdrawal, cerebrovascular lesions, or an idiopathic etiology. There are many types of seizures as well. The seizure may be localized to one cerebral hemisphere (simple partial or complex partial seizure) or affect both hemispheres (tonic-clonic seizures). Seizures that develop in childhood are known as absence (petit mal) seizures. Any of these types of seizures may lead to a condition known as status epilepticus, which is defined as prolonged (longer than 30 minutes) or repetitive seizures without a return to consciousness. This state is considered a medical emergency. An individual who has two or more unprovoked seizures is considered to be epileptic. Control of seizures varies and may be treated with anticonvulsant therapy or neurosurgical procedures. Like any other organ system, the brain is susceptible to infection. Two of the more common types of central nervous system infections are meningitis and encephalitis. Meningitis is defined as an inflammation of the meninges. This disease process may lead to headaches, nuchal rigidity, and photophobia. If left untreated, it may lead to cerebral edema, subdural effusions, ventriculitis, and/or hydrocephalus. Antibiotics are the treatment of choice depending on the infectious agent involved. Typical infectious agents are E. coli, Listeria, S. pneumoniae, N. meningitidis, HSV, H. influenzae B, GBS, and gram-negative rods. In patients who are immunocompromised (such as human immunodeficiency virus [HIV] patients), the individual may be susceptible to Cryptococcus, CMV,
toxoplasmosis, and JC virus. Encephalitis is characterized by inflammation of the brain parenchyma. This disease is usually caused by HSV or the arboviruses. The patient will typically present with an altered consciousness, headache, fever, and/or seizures. Antivirals are the typical treatment. Most intracranial neoplasms are metastatic (70 percent). The most common primary tumors that metastasize to the brain are from the lung, breast, kidney, gastrointestinal tract, and skin. Of the primary brain tumors, approximately 40 percent are benign in nature. The most common primary neoplasms are astrocytomas, glioblastoma multiforme (GBM), meningiomas, acoustic neuromas, medulloblastomas, and ependymomas. GBMs and meningiomas are more common in adults, while medulloblastomas and astrocytomas are more common in children. These tumors may lead to mass effect or increased intracranial pressure. Neoplasms may also cause focal neurologic deficits or headaches. Tumors are usually diagnosed via computed tomography (CT) or magnetic resonance imaging (MRI). Surgical resection, radiation, and chemotherapy are the treatments of choice depending on the severity and type of tumor. Trauma may lead to various types of brain disease. After a traumatic brain injury, an individual may be subject to a number of different types of bleeds within the brain. For instance, a trauma patient may suffer from subarachnoid hemorrhage, subdural hematomas, epidural hematomas, intraparenchymal hemorrhage, or contusions. If the bleeding is extensive enough, there may be a mass effect, which causes compression of other parts of the brain, leading to cranial nerve deficits or compression of the brain stem and life-threatening conditions. Diagnostic Techniques There are a number of ways to determine the exact nature of a neurological disease process. In addition to the medical history and physical examination, diagnostic procedures are often warranted. For instance, a spinal tap or lumbar puncture can be used to help distinguish and differentiate between disease states such as infections, injuries, tumors, or bleeding in the brain and spinal cord. This procedure requires sampling of cerebrospinal fluid. Imaging techniques are also useful for diagnostic purposes. Specifically, CT and MRI of the brain and
Brain Injuries
spinal cord may help to differentiate between disease processes. CT utilizes X-rays taken from multiple angles to generate a two-dimensional image via a computer. MRI, on the other hand, is based upon magnetic fields and high-frequency radio waves. MRI detects most neurologic disorders with more precision than CT. Specifically, these imaging techniques are valuable in identifying disease processes such as tumors, cerebral infarcts, hemorrhage, and multiple sclerosis. Functional MRI may also help to identify disease processes by demonstrating which parts of the brain are active when performing various tasks. Magnetic resonance angiography (MRA) and cerebral angiography are techniques that are devoted to imaging blood vessels. While cerebral angiography provides more accurate imaging, MRA is noninvasive. Positron emission tomography (PET) is an imaging technique used to evaluate brain function based upon radioactive labeling of necessary substances, such as oxygen or sugar. Single photon emission computed tomography (SPECT) is another technique that relies on radioactive labeling. This technique produces images of blood flow to the brain. Doppler ultrasonography can also be used to show blood flow in different vessels in the brain. Not only is it important to identify physical abnormalities in the brain, but it is also valuable to evaluate the electrical properties of the brain. Electroencephalography (EEG) is a noninvasive procedure that enables one to evaluate the brain’s electrical activity as wave patterns. There are characteristic patterns associated with various disease states, including seizures, brain damage secondary to stroke, and confusion due to liver failure. EEG can also be used to detect electrical activity after using evoked responses. Identifying evoked responses can be used to determine brain function. Electromyography and nerve conduction studies are also electrical studies that can be used to evaluate electrical activity being transferred to muscle. SEE ALSO: Brain Cancer; Brain Injuries; Brain Malforma-
tions.
BIBLIOGRAPHY. American Heart Association, 2001 Heart
and Stroke Statistical Update (American Heart Association, 2000); R. Nabbout and O. Dulac, “Epileptic Enceph-
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alopathies: A Brief Overview,” Journal of Clinical Neurophysiology (v.20/6, 2003); R.N. Rosenberg, et al., eds., The Molecular and Genetic Basis of Neurological Disease, 2nd ed. (Butterworth-Heinemann, 1997). Darrin Lee University of California, Irvine
Brain Injuries A traumatic brain injury (TBI) is a significant blow, shock, or penetrating head injury that disrupts the function of the brain. It is a nondegenerative, noncongenital insult to the brain from an external mechanical force. This may possibly lead to permanent or temporary impairments of cognitive, physical, and psychosocial functions with a diminished or altered level of consciousness. The severity may range from mild or brief change in mental status or consciousness to severe or extended periods of unconsciousness or even amnesia. A TBI can result in short- or long-term brain function problems and contributes to morbidity and fatality in multiple systems trauma throughout the world. Globally, TBI accounts for a significant amount of trauma and related illness and injury. The effects of poor safety standards in industry, motor vehicle crashes and lack of helmets and seat belt use, conflict- and war-related injury such as explosion/blasts and violence, sports injuries such as boxing and contact sports, increased alcohol and drug consumption, as well as the inability for many of those with head injury to receive prompt and adequate diagnosis and treatment make TBI a major problem for the developing world. Of the 1.5 million who sustain a TBI each year in the United States, roughly 50,000 die, 235,000 are hospitalized, and about 1.1 million are treated and released from an emergency department. TBI accounts for approximately 40 percent of all deaths from acute injuries in the United States. Globally, the number of patients who receive TBI but do not seek medical attention or simply do not have any access to medical care is unknown and thought to be significant in remote areas, developing nations, and areas currently in conflict. The leading causes of TBI throughout the world are preventable and vary from country to country. The
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At least 5.3 million Americans have a long-term need for help performing activities of daily life as a result of a traumatic brain injury.
most common are from falls (both ground level and from height), motor vehicle crashes, blunt trauma, penetrating trauma, and explosion blasts. In areas of political conflict and war, many other mechanisms exist that cause TBI. For example, a concussion is caused by deformity of the deep structures of the brain that can lead to neurological dysfunction. Concussion is considered a mild form of diffuse axonal injury and is a mild form of TBI. Males are about 1.5 times more likely than females to sustain a TBI. The two age groups at highest risk for TBI in the United States are 0 to 4 year olds and 15 to 19 year olds. Military duties increase the risk of sustaining a TBI and many normal soldiers and forced child soldiers throughout Africa and other regions in conflict suffer the most from TBI. In the United States, African Americans have the highest death rate from TBI. The Glasgow Coma Scale (GCS) defines severity of TBI within 48 hours of injury. GCS is a standardized system used to assess the degree of brain impairment and to identify the seriousness of injury as it relates to outcome. The three determinants in the GCS are eye opening, verbal responses, and motor responses. This standard is accepted globally and aids in predicting long-term negative effects and morbidity. The Centers for Disease Control and Prevention (CDC) estimates that at least 5.3 million Americans currently have a long-term or lifelong need for help to perform activities of daily living as a result of a TBI.
Long-term effects for those who receive any form of TBI can be considerable and are often undertreated. They include a lack of improving memory and problem solving, an inability to manage stress and emotional change, inability to control temperament, and a significant inability to improve or maintain job skills. Furthermore, TBI can cause a wide range of functional changes affecting thinking, sensation, language, and/or emotions. It can also cause epilepsy and increase the risk for conditions such as Alzheimer’s and Parkinson’s disease. Direct medical costs and indirect costs such as lost productivity of TBI in 1995 were estimated at $56.3 billion in the United States. It is difficult to calculate these costs for the developing world as poor data exist and TBI is often underdiagnosed. The financial cost is estimated at approximately $4 billion per year in the United States. This cost involves diagnostic equipment and new treatments that are not available to the developing world. Many of these areas are the very ones that need it most and experience TBI from protracted war and conflict and lack of any safety standards in industry or at work. Furthermore, these estimates try to include loss of potential income and financial burden on relatives who may need to become caregivers, cost of acute care, and other medical expenses such as continuous ambulatory and rehabilitation care. SEE ALSO: Activities of Daily Living (ADLs); Alcohol and
Youth; Bross, Irwin D.J.; Child Abuse; Child Safety; Concussion; Fainting; Falls; Gage Phineas; Head and Brain Injuries; Hydrocephalus; Knockout; Seizures. Bibliography. J.A. Langlois, W. Rutland-Brown, and K.
E. Thomas, Traumatic Brain Injury in the United States: Emergency Department Visits, Hospitalizations, and Deaths (Centers for Disease Control and Prevention, National Center for Injury Prevention and Control, 2004); L. Miller, R. Hayes, and D. Thurman, eds., Head Trauma: Basic, Preclinical, and Clinical Directions: The Epidemiology and Economics of Head Trauma (Wiley, 2001); National Institute of Neurological Disorders and Stroke, Traumatic Brain Injury: Hope through Research, www. ninds.nih.gov (cited January 2007) (National Institutes of Health, 2002). John Michael Quinn, V University of Illinois at Chicago
Brain Malformations Brain malformations affect children worldwide. Usually, they form congenitally, have no effective means of prevention or treatment, and are associated with poor prognoses. Anencephaly is the absence of a major portion of the brain, skull, and scalp, and results from failure of the neural tube to close. (The neural tube is the primitive structure from which develops the central nervous system.) Children born with anencephaly are essentially headless, and, therefore, death is certain. In America, 1,000 to 2,000 children are born with anencephaly every year. Females are more likely to be affected than males, and insufficient maternal intake of folic acid also increases the likelihood of this and other neural tube defects. Colpocephaly is the enlargement of the occipital horns, the part of the brain located at the posterior end of the lateral ventricles, because of insufficient development of the posterior cerebrum. The precise cause of colpocephaly is unknown, but is believed to result from some intrauterine disturbance between the second and sixth months of pregnancy. Children with this malformation present with microcephaly, mental retardation, muscle spasms, and seizures. The prognosis with colpocephaly is directly correlated with the degree of abnormality. Holoprosencephaly results from the failed development of the prosencephalon (embryonic forebrain). The prosencephalon fails to divide and form the two cerebral hemispheres, and this failure results in defects in both the brain and face. About one-half of holoprosencephaly cases are caused by chromosomal defects, such as trisomy 13 (Patau syndrome) and 18 (Edwards syndrome). The clinical presentation of this disorder falls along a broad spectrum, with defects as minor as a cleft lip or as severe as cyclopia (one eye). One risk factor for the development of holoprosencephaly is birth to a diabetic mother. Hydranencephaly is a form of porencephaly, characterized by a brain with absent cerebral hemispheres, replaced instead with cerebrospinal fluid (CSF)-filled sacs. This condition is caused by vascular insult (i.e., stroke), injuries, or infections after week 12 of pregnancy. Although the infant may appear normal at birth, after a few weeks, he or she demonstrates irritability and increased muscle tone followed by seizures and hydrocephalus after several months. Death
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typically occurs during the first year of life, although reports exist of patients surviving into their 20s. Iniencephaly is a combination of retroflexion (backward bending) of the head and severe spinal defects. Like anencephaly, iniencephaly is a neural tube defect. Affected infants are born looking upward because of the retroflexion, and the skin of the face is connected directly to the skin of the chest, while the skin of the scalp is connected to the skin of the back. Thus, patients appear to have no neck. Females are affected more than males. These patients tend to survive only for a few hours after birth. Lissencephaly means “smooth brain” and is an umbrella term that encompasses several disorders, including Miller-Dieker syndrome, isolated lissencephaly sequence, and Walker-Warburg syndrome. The normal brain has many folds and grooves (gyri and sulci), but brains affected by lissencephaly do not. Lissencephaly is caused by defective neuronal migration, which itself is thought to be caused by viral infections, inadequate blood supply to the embryonic brain, or genetic disorders (namely X- or chromosome 17linked). Symptoms of lissencephaly include abnormal facies, difficulty swallowing, failure to thrive, and psychomotor retardation. Megalencephaly, or macrencephaly, is the presence of an abnormally large and heavy brain compared to the average weight for age and gender. The cause of this condition is a disturbance of the regulation of cell reproduction or proliferation. Children with megalencephaly typically present with developmental delay and seizures, and males are affected three to four times more frequently than females. The incidence of this condition is estimated to be between 2 percent and 6 percent. Megalencephaly (macrencephaly) is not to be confused with macrocephaly, which is a large head but not necessarily a large brain. Microcephaly means “small head” and is formally defined as a head circumference that is smaller than 2.5 standard deviations from the average given an age and gender. It can be caused by a variety of conditions (exposure to chemicals and radiation) and chromosomal abnormalities that result in an inappropriately developing brain. Other risk factors include maternal infections, diabetes, vitamin and nutrient deficiency, and drug or alcohol abuse. Along with a smaller head circumference, patients with microcephaly can present with developmental delay.
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Porencephaly is an extremely rare disorder where there are CSF-filled cysts or cavities on the surface of the brain. This can be caused by genetics, poor brain development, or destruction of brain tissue by stroke or infection after birth. The pathogenesis of this disease is as follows: Any abnormal area of the brain is walled off with smooth tissue, the brain tissue is cleared by the body, and the space becomes filled with CSF. Signs and symptoms of porencephaly include developmental delay, paralysis, decreased muscle tone, seizures, and macro- or microcephaly. Death results before adulthood. Schizencephaly is a type of porencephaly characterized by abnormal slits (clefts) in the cerebral hemispheres. This disorder can be caused by genetic abnormalities, certain medications taken by the mother during pregnancy, exposure to toxins, or vascular injury. Patients with schizencephaly affecting their entire brain will typically suffer from developmental delay, while patients with only one side of the brain affected may have unilateral (one-sided) weakness but potentially normal intelligence. SEE ALSO: Birth Defects; Folic Acid; Hydrocephalus; Neu-
ral Tube Defects; Seizures.
Bibliography. National Institute of Neurological Dis-
orders and Stroke, “Cephalic Disorders Fact Sheet,” www. ninds.nih.gov (cited February 2007); Margaret G. Norman, et al., Congenital Malformations of the Brain: Pathologic, Embryologic, Clinical, Radiologic and Genetic Aspects (Oxford University Press, 1995). Khoi D. Than, M.D. Johns Hopkins University School of Medicine
Brazil Brazil, the largest country in Latin America, has become a leading economic power in the region. The quality of life and healthcare are relatively high for the region, and the United Nations Development Programme (UNDP) Human Development Reports rank Brazil 69th of 177 countries on general quality-of-life issues. According to the constitution adopted in 1988, the government of Brazil is required to provide health-
care under the Unified Health System (SUS) and must adhere to specific guidelines and principles. In practice, the national government has shifted most of the responsibility for healthcare to municipalities. Six percent of all national government expenses are directed toward meeting the goals of SUS. Approximately 7.6 percent of the Gross Domestic Product (GDP) is spent on healthcare, and the government allots $597 (international dollars) per capita for such expenses. The private sector is responsible for most of the healthcare funding in Brazil, providing 54.7 percent of total expenditures. Out-of-pocket expenses account for 64.20 percent of private expenses. The government furnishes 45.3 percent of total health spending, but none of that amount is set aside for social security. There are 1.15 physicians, 3.84 nurses, 1.11 dentists, and 0.30 pharmacists per 1,000 population in Brazil. Vast income disparities persist, and Brazil is ranked 59.7 on the Gini index of human inequality. The richest segment of the population claims almost a third of the country’s resources, leaving less than 1 percent for the poorest segment. With a per capita income of $8,300, Brazil ranks 96th in world incomes. However, Brazil has the fourth highest income in Latin America, outranked by Chile ($11,900), Costa Rica ($11,400), and Mexico ($10,000). Because of the vast inequality, over a fifth of Brazil’s population lives in poverty. Much of the poverty is found among the 20 percent of the workforce that are engaged in agriculture, chiefly at the subsistence level. Nearly 10 percent of the labor force is unemployed. More than 86 percent of Brazil’s population is literate. Around 95 percent of all children are enrolled in primary school; yet, only 50 percent of females and 42 percent of males regularly attend secondary school. While 96 percent of urban residents have sustained access to safe drinking water, only 58 percent of rural residents are able to meet this basic need. Among urban residents, 83 percent have access to improved sanitation, but that number plummets to 35 percent among rural residents. Brazilians have a life expectancy of 77.97 years, and females outlive males by an average of eight years. On the average, each Brazilian woman produces 1.91 children. Some 77 percent of adult women use birth control. Consequently, the fertility rate dropped from 5 children to 2.8 children per woman between 1970 and 2004. Skilled professionals attend 96 percent of all
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births, and 86 percent of women receive prenatal care. Brazil’s adjusted maternal mortality rate is 260 deaths per 100,000 live births. In 1993, the government launched the National Program for Complete Care for Women’s Health, targeting prevention, diagnosis, and recuperation. Brazilian women’s groups have faulted the program and are engaged in developing a new plan designed to be more comprehensive and effective. Infant mortality is high in Brazil at 28.6 deaths per 1,000 live births, and male infants (32.3) are more vulnerable than female infants (24.7). However, Brazil has been successful in reducing childhood mortality over the last several years. Between 1990 and 2004, under-5 mortality fell from 60 to 34 deaths per 1,000 live births, and infant mortality fell from 50 to 32 deaths per 1,000 live births. In spite of this, 10 percent of all infants are underweight at birth. Six percent of under-5s fall into this category, and 1 percent of this age group is severely underweight. Two percent of under-5s suffer from moderate-to-severe wasting, and 11 percent experience growth stunting. The government subsidizes 100 percent of required vaccines, and childhood immunizations are consequently high. At least 99 percent of infants receive immunizations against tuberculosis and measles, and 98 percent are immunized against polio. Some 96 percent of infants receive diphtheria, pertussis, and tetanus (DPT1 and DPT3) and Haemophilus influenzae type B vaccinations. Ninety percent are immunized against hepatitis B. HIV/AIDS has taken a heavy toll on the health of Brazilians and has been instrumental in lowering life expectancy and population growth rates and in raising infant mortality and death rates. It has also negatively affected the distribution of population by age and sex. The current adult prevalence rate is 0.7 percent, placing Brazil 63rd in the world in number of HIV/AIDS cases reported. Some 660,000 Brazilians are living with this disease, which has claimed 15,000 lives. The early 21st century proved that Brazil is also extremely vulnerable to other communicable diseases. Dengue/dengue hemorrhagic fever surfaced in 2002, and yellow fever was reported in 2000, 2001, and 2003. Brazil was also one of the countries that experienced an outbreak of severe acute respiratory syndrome (SARS) in 2003. In September 2006, Brazil became one of five countries (the other four were France, Britain, Norway, and Chile) to adopt a program taxing airfares
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to provide funding for treating children around the world who have contracted AIDS, tuberculosis, and malaria. With an ultimate goal of treating 200,000 people affected with AIDS, 150,000 children diagnosed with tuberculosis, and 28,000,000 infected with malaria, the group is working through the Genevabased UNITAID and with former U.S. president Bill Clinton’s foundation to encourage drug companies to provide discounted drugs for the program. At least 12 other countries are considering similar programs. SEE ALSO: Healthcare, South America. BIBLIOGRAPHY. Central Intelligence Agency, “Brazil,”
World Factbook, www.cia.gov (cited January 2007); Commission on the Status of Women, “Bolivia,” www.un.org/ womenwatch (cited January 2007); Sonia Miriam Draibe and Marta Teresa S. Arretche, “Involving Civil Society Brazil,” in Dagmar Raczynski, ed., Strategies to Combat Poverty in Latin America (Inter-American Development Bank, 1995); Celia W. Dugger, “Five Nations to Tax Airfare to Raise Funds for AIDS Drugs,” New York Times Online (September 19, 2006); Manuel Antonio Garretón, et al., Latin America in the Twenty-First Century: Toward a New Sociopolitical Matrix (North-South Center Press, 2003); Carlos Gerardo Molina and José Nuñez del Arco, eds., Health Services in Latin America and Asia (Johns Hopkins University Press, 2001); Pan American Health Organization, “Brazil,” www.paho.org (cited January 2007); United Nations Children’s Fund (UNICEF), “Brazil,” www.unicef. org (cited January 2007); World Bank, “Brazil Data Profile,” devdata.worldbank.org (cited January 2007); World Health Organization, “Brazil,” www.who.int (cited January 2007). Elizabeth R. Purdy, Ph.D. Independent Scholar
Breast Cancer Breast cancer is cancer of the breast where cancerous growth arises in the tissues of the breast. If the malignant growth arises in the lining of the ducts that carry milk from the milk-producing lobules to the nipple, the breast cancer is called ductal carcinoma. If the malignant growth arises in the lining of lobules, the breast cancer is called lobular carcinoma.
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Ductal and lobular carcinomas may grow only inside the ducts and lobules of the breast or may spread into adjacent tissue. If the cancer cells grow only inside the ducts or lobules, the disease is called ductal carcinoma in situ (DCIS) or lobular carcinoma in situ (LCIS). Patients with DCIS or LCIS have a higher risk of invasive breast cancer. While ductal carcinoma and lobular carcinoma represent the most common breast cancers (about 85 percent of all cases for the former and 8 percent for the latter), there are other rare types of breast cancers, such as other epithelial carcinomas, sarcomas, lymphomas and Paget’s disease of the nipple. Epidemiology Breast cancer is the leading cause of cancer death among women worldwide. More than 1 million women will be diagnosed with breast cancer in 2007 worldwide. Risk varies by over fivefold among societies, and the highest risk is in the industrialized nations. The American Cancer Society estimates that nearly one in eight women in the United States will have breast cancer in her lifetime. The 2007 statistics show that over 180,510 persons (178,480 for female and 2,030 for males) will be diagnosed with breast cancer (not including carcinoma in situ) and 40,000 people will die from the disease in the United States. While breast cancer is the most common type of cancer among women, breast cancer also occurs in men. Male breast cancer is about 100 times less frequent than the disease in women. The incidence rate of breast cancer is low before 40 years of age, but the rate increases continuously and rapidly with age, and peaks at the oldest ages. In the United States, breast cancer is diagnosed more often in white women than in Latina, Asian, or African-American women. Incidence rates of breast cancer were reported to be increasing in the 1980s and 1990s; recent studies suggest that the increase has leveled off, and the reported earlier increase appears to be largely due to early detection through mammography screening. Breast cancer mortality is also declining, which can be largely attributed to early detection and better treatment. Etiology While considerable efforts have been made, little is known about the etiology of breast cancer. Breast cancer risk has been traditionally linked to menstrual
and reproductive factors, and genetics. These factors can account for only about 25 percent of breast cancer cases. Thus, much of the etiology is still unexplained. It is suggested that breast cancer is originated in utero. Exposure to higher levels of endogenous hormones in utero has been suggested to be a risk factor for female breast cancer. Neonatal jaundice has been linked to an increased risk of breast cancer and neonatal jaundice is related to high estrogen levels among infants. Female members of dizygotic twins were reported to have a higher risk of breast cancer and dizygotic twin pregnancies were shown to have higher pregnancy estrogen levels because dizygotic twins tend to have two placentas. First-born women and women born to older mothers were shown to have greater risk of breast cancer; pregnancy estrogen concentrations are higher during the first pregnancy and among older women. Maternal pregnancy toxemia and preeclampsia have been linked to a reduced risk of breast cancer, and these conditions are associated with low levels of pregnancy estrogens. Birth weight and birth length have been linked to breast cancer risk, and fetal growth was positively correlated with pregnancy estrogen levels in both blood and in urine. Age at puberty and menarche in young girls has been reported to be decreasing in many populations, including the United States. Age at puberty and menarche are well-established risk factors for breast cancer. It is estimated that a one-year decrease in age at menarche would increase breast cancer risk by at least 7 to 10 percent. Because of this established relationship, it is suggested that factors that affect age at puberty and menarche would also affect breast cancer risk. Factors that have been linked to a woman’s sexual maturation include nutritional status, physical activity, obesity, health status, psychological factors, prenatal growth factors, endogenous hormones, and genetics. Studies suggest that increased energy intake in childhood has contributed to decreasing age at menarche. Higher vegetable protein intake was associated with a later age at puberty, while higher animal protein and lower vegetable protein intakes were associated with early age at menarche. A diet rich in fat during the preadolescent years could accelerate age at menarche. Women on vegetarian diets have decreased plasma concentrations of estrogens, and have a later
age at menarche. Higher consumption of grains and legumes was associated with later menarche. Studies have also reported that soy consumption is associated with sexual maturation. Consumption of soy milk with isoflavones is associated with a significant lengthening of overall menstrual cycle length in women, and a lengthening of the menstrual cycle would reduce breast cancer risk. Physical activity has been linked to girls’ sexual maturation and breast cancer risk. Girls who engage in strenuous physical activity such as regular ballet dancing, gymnastics, running, or swimming have a delay in the onset of menses. It is reported that each year of premenarcheal training delays menarche by five months. An alteration of energy balance in early life through increased physical activity could delay age at sexual maturation and reduce the risk for breast cancer in later life. Obesity is of critical importance for female sexual maturation and the subsequent occurrence of breast cancer in adulthood. It is hypothesized that subcutaneous fat tissue acts as a secondary hormonal gland and adipose tissue influences the synthesis and release of hormones (e.g., estrogens), and thus promotes the onset of menarche. A reduced risk of breast cancer has been associated with early age at first full pregnancy, increasing number of pregnancies, and breastfeeding for a long period. On the other hand, an increased risk of breast cancer is associated with never having children, taking diethylstilbesterol during pregnancy, and late age at menopause (after age 55). Most epidemiologic studies do not support an overall association between oral contraceptive use and the risk of breast cancer, while some suggest that particular subgroups of oral contraceptive users may be at increased risk. Use of estrogens for postmenopausal replacement therapy has been associated with an increased risk of developing breast cancer, particularly among women who have used estrogens for a long time in relatively high dosages. It is widely accepted that relatively high doses of ionizing radiation can cause breast cancer, while questions remain regarding the importance of age at exposure, shape of the dose‑response curve, and the length of the latency period. Low-dose radiation and exposure to electromagnetic fields have not been consistently found to increase the risk of breast cancer.
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It is suggested that shift work occupation and nighttime lighting at home in modern societies might explain, in part, the high risk in industrialized societies. Recent studies of circadian gene polymorphisms and breast cancer risk appear to support the hypothesis. Tobacco smoking was not considered to be a major risk factor for female breast cancer. Several recent studies, however, suggested that both active and passive smoking increase the risk of female breast cancer if active or passive smokers were compared with the subjects who had never smoked and had not been exposed to passive smoke. The risk of breast cancer associated with tobacco smoking may vary by hormone receptor status and by genetic polymorphisms. Epidemiological studies do suggest a modest increased risk of breast cancer in women who consume alcohol on a regular basis. So far, there are no clear links between adult dietary intakes and breast cancer risk. Most epidemiological studies have either suggested a weak association or no association between fat intake and breast cancer risk. A reduced risk of breast cancer, however, appears to be associated with an increased intake of dietary fiber and vegetables rich in vitamins A and C. Recent studies do not support an association between hair dye use and breast cancer risk, nor do they support an overall association between DDT/ DDE and other organochlorine pesticides and breast cancer risk. However, people having higher body levels of PCBs may have an increased risk of female breast cancer among those who have CYP1A1 m2 genetic polymorphism. Women who are overweight or obese have a higher risk of breast cancer after menopause. Losing weight after menopause may reduce the risk. Strenuous long-term physical activity is reported to decrease a woman’s risk of invasive and in situ breast cancer. Recent studies suggest that use of antibiotics is associated with an increased risk of breast cancer. It is currently unknown, however, if it was the antibiotics’ effects or the underlying conditions which led to the increased breast cancer risk. While benign breast diseases (BBDs) are considered to be associated with an increased risk of breast cancer, the risk seems largely confined to the less common type of proliferative disease. Women with atypical hyperplasia have about three to four times the breast cancer risk of women without proliferative
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Breast cancer is the leading cause of cancer death among women worldwide; over 1 million women will be diagnosed with it in 2007.
disease. Women who undergo breast biopsy that reveals nonproliferative lesions have no greater breast cancer risk. An increased risk of breast cancer was reported among women whose mammography shows more dense tissue. The most powerful risk factor for breast cancer identified to date is history of breast cancer in a first-degree relative (mother, sister, or daughter). A family history of breast cancer in a first-degree relative increases the risk by approximately 80 percent over that of women without a family history. The risk is greater for a family history of bilateral breast cancer, and if a family member had breast cancer before age 40. Certain genes have been linked to an increased risk of breast cancer, particularly BRCA1 and BRCA2 genes. Recent studies also show clock genes and DNA repair genes may also be related to breast cancer risk in young women. It should be pointed out that a majority of breast can-
Prevention and Detection There is no established program that can be offered for breast cancer prevention; this is due to the fact that epidemiologic studies of breast cancer frequently have contradictory results, even with respect to major suspected risk factors as summarized above. The known breast cancer risk factors can account for only a small proportion of breast cancer cases. However, this does not mean that women cannot do anything to reduce their breast cancer risk. In fact, based on the epidemiological studies, changes can be made to reduce breast cancer risk, such as staying physically active, preventing weight gain (especially after menopause), eating more fruits and vegetables, and limiting alcohol intake. Breast self-exams, clinical breast exams, and regular mammography screening can lead to early detection of breast cancer, or detect the disease at an early stage. Detection of breast cancer before symptoms can lead to early treatment, which improves the survival probability from the disease. Regular and proper breast selfexams may help to find unusual changes in the breasts, such as lumps. While not all the lumps are cancerous changes, medical advice should be sought for any suspicious changes in the breast detected through selfexams. A doctor or trained specialist may check for any abnormal signs in the breasts, such as the shape, dimpling, and the lump of the breast; enlarged lymph nodes near the breasts; nipple appearance, tenderness or discharge, and other abnormal signs. In the United States, the American Cancer Society recommends a mammogram every year or two for women between the ages of 40 and 50, and a yearly mammogram for women over the age of 50. Women who are younger than 40 but at higher risk for breast cancer (such as having family breast cancer history) should get advice from their doctor about whether mammography screening should be conducted and how frequently to have the screening. It should be recognized that mammography screening itself cannot make a final diagnosis of breast cancer. However, if mammography screening shows suspicious areas, further diagnosis can be sought. Women may be exposed to radiation through mammography screening, but this radiation dose is very low, and based on epidemiological studies, exposure at this low level
should carry very low risk, especially for exposure after age 40. The benefits of early detection of the disease are considered to outweigh the potential risk. Symptoms, Diagnosis, and stages Clinical presentation of breast cancer depends on the stage of the disease. Early breast cancer may have no symptoms. Patients can present with breast anomalies such as lumps, nipple discharge, nipple retraction, Paget’s disease of the nipple, inflammatory skin changes, skin retraction, and so forth. First symptoms can be enlarged axillary or supraclavicular lymph nodes or metastases (bone, skin, lung, liver, brain, etc.). Patients with breast anomalies should undergo imaging procedures to try and characterize the tumor. Diagnostic mammography is an important tool for diagnosing breast cancer, especially in non-dense breasts. Ultrasounds and MRI can also be used. If a tumor is found with these techniques, a cytological or a histological confirmation is needed. Pathological analysis of the tumor through needle biopsy or surgical biopsy is important. The pTNM classification is used to stage the disease according to the size of the tumor (pT), the number of lymph nodes involved (pN), and the existence or not of distant metastases. Very early breast cancer is called carcinoma in situ, which means the disease is contained in either the breast duct or the lobule. For invasive breast cancers, the disease is divided into four stages (stages I–IV) based on how far the disease has spread to other parts of the body (stage I: the tumor is contained with the breast and is smaller than 2 cm; stage II: the tumor is larger than 2 cm and/or has spread to less than 4 lymph nodes under the arm; stage III: the cancer has spread to other lymph nodes or other tissues near the breast; and stage IV: the cancer has spread to distant organs of the body). Treatment Treatment should be a multidisciplinary decision involving the patient. A number of tumor characteristics have important therapeutical implications, such as tumor stage and grade, expression or not of estrogen, and/or progesterone receptors and the overexpression or not of ERBB2. For early breast cancer, surgery is one of the bases of treatment. Breast conserving surgery is frequently offered to patients, if feasible. If mastectomy is per-
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formed (large tumors, inflammatory disease, patient’s choice), patients should be offered reconstruction. Homolateral axillary lymphadenectomy should be performed to aid in determining prognosis and treatment options. Lymphatic mapping and sentinel lymph node (SLN) biopsy are still being evaluated. The principle of SLN is to do complete axillary dissection only in patients with positive SLN, avoiding complete lymphadenectomy’s complications in patients with no axillary involvement. Radiotherapy is also an important part of breast cancer treatment. Postoperative whole breast irradiation with or without a boost to the tumor bed is given to patients who have had breast-conserving surgery. It also can be given to the chest wall after mastectomy or to the axilla after lymphadenectomy if adverse prognostic features are present. Radiotherapy can be used for metastasis (painful bone metastases, brain metastases). Chemotherapy can be used in the adjuvant, the neoadjuvant, and the metastastic setting. Adjuvant chemotherapy is used to decrease risk of relapse. It is used in patients with poor risk features: large tumors, high-grade tumors, no expression of hormone receptors, node-positive tumors. The main regimens are anthracycline-based (such as FAC or FEC: fluorouracile, doxuribicin or epirubicin and cyclophosphamide). Regimens with taxanes and anthracyclines have been studied in node-positive patients. Despite increasing toxicity, they seem to improve survival. Neoadjuvant chemotherapy is usually used to reduce the size of the primary tumor to offer breast-conserving surgery. Hormone therapy is used as an adjuvant therapy for patients with endocrine-responsive disease. Premenopausal women are usually offered tamoxifen with or without ovarian function suppression. Postmenopausal women are more and more frequently offered aromatase inhibitors, which have been shown to be superior to tamoxifen in that setting. Duration of endocrine therapy is five years. The intravenous antibody trastuzumab (Herceptin®) has shown a benefit as an adjuvant treatment for patients whose tumor overexpresses ERBB2. The treatment of metastatic disease depends on the patient’s general health, the tumors’ characteristics (endocrine response, ERBB2 overexpression), the location of the metastases, and what treatments the patient has already received. For patients with
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endocrine-responsive and slow-growing disease, and non-life threatening metastases, hormone therapy can be used. For patients with more aggressive disease, chemotherapy should be considered. Anthracyclines are usually the first choice if they have not been used before. Taxanes are active for disease that relapses after anthracycline-based regimens. A wide range of drugs have been tested in the metastatic setting (capecitabine, vinorelbine, gemcitabine). The objectives of this treatment are to obtain the best symptom palliation and the best survival with the best possible tolerance. Trastuzumab can be used in patients whose tumor overexpresses ERBB2. SEE ALSO: Breast Diseases; Breast Implants/Breast Recon-
struction; Cancer (General); Cancer Alternative Therapy; Cancer Chemotherapy; Cancer Radiation Therapy; Cancer—Coping with Cancer; Women’s Health. Bibliography. M. Clarke, et al., “Effects of Radiother-
apy and of Differences in the Extent of Surgery for Early Breast Cancer on Local Recurrence and 15-Year Survival: An Overview of the Randomized Trials,” Lancet (v.17/366, 2005); A.S. Coates, et al., “Five Years of Letrozole Compared with Tamoxifen as Initial Adjuvant Therapy for Postmenopausal Women with Endocrine-Responsive Early Breast Cancer: Update of Study BIG 1-98,” Journal of Clinical Oncology (v.25/5, 2007); Early Breast Cancer Trialists’ Collaborative Group (EBCTCG), “Effects of Chemotherapy and Hormonal Therapy for Early Breast Cancer on Recurrence and 15-Year Survival: An Overview of the Randomised Trials,” Lancet (v.14–20/265, 2005); A. Howell, et al., “Results of the ATAC (Arimidex, Tamoxifen, Alone or in Combination) Trial after Completion of 5 Years’ Adjuvant Treatment for Breast Cancer,” Lancet (v.365/9453, 2005); A. Jemal, et al., “Cancer Statistics, 2007,” CA: A Cancer Journal for Clinicians (v.57, 2007); F. Laden, et al., “DDE and PCBs and Breast Cancer: Combined Analysis of Five U.S. Studies,” Journal of the National Cancer Institute (v.93, 2001); M.J. Piccart-Gebhart, et al., “Trastuzumab after Adjuvant Chemotherapy in HER2-Positive Breast Cancer,” New England Journal of Medicine (v.353/16, 2005); R.A. Smith, V. Cokkinides, and H.J. Eyre, “Cancer Screening in the United States, 2007. A Review of Current Guidelines, Practices, and Prospects,” CA: A Cancer Journal for Clinicians (v.57, 2007); B.W. Steward and P. Kleihues, eds., World Cancer Report (IARC Press, 2003); F.A. Tavassoli and P. Devilee, eds.,
World Health Organization Classification of Tumours. Pathology and Genetics of Tumours of the Breast and Female Genital Organs (IARC Press, 2003); U. Veronesi, et al., “Breast Cancer,” Lancet (v.365, 2005); Y. Zhang, et al., “Polychlorinated Biphenyls, Cytochrome P-4501A1 Genetic Polymorphisms and Risk of Female Breast Cancer in Connecticut,” American Journal of Epidemiology (in press); T. Zheng, et al., “DDE and DDT in Breast Adipose Tissue and Risk of Female Breast Cancer,” American Journal of Epidemiology (v.150, 1999); T. Zheng, et al., “Exposure to Electromagnetic Fields from Use of Electric Blankets and Other Electrical Appliances and Breast Cancer Risk,” American Journal of Epidemiology (v.151, 2000); T. Zheng, et al., “Lactation and Breast Cancer Risk: A CaseControl Study in Connecticut,” British Journal of Cancer (v.84, 2001); T. Zheng, et al., “Radiation Exposure from Diagnostic and Therapeutic Treatment and Risk of Breast Cancer,” European Journal of Cancer Prevention (v.11, 2002); T. Zheng, et al., “Use of Hair Coloring Products and Risk of Female Breast Cancer in Connecticut,” European Journal of Cancer (v.38, 2002). Tongzhang Zheng Yale University Helen Boyle Independent Scholar Yawei Zhang General Editor Peter Boyle International Agency for Research on Cancer
Breast Diseases To understand breast conditions, it is necessary to appreciate the distinct tissues that make up the breast. The breast is composed primarily of glandular tissues and supporting, or stromal, tissues. The glandular part of the breast includes the lobules, which produce milk, and the ducts, which carry the milk from the lobules to the nipple. The stromal tissue includes fatty, or adipose, tissue and fibrous connective tissue, which is made up of ligaments that support the breast. Breast diseases are a wide spectrum of diseases ranging from benign fibromas to cancerous tumors associated with varying prognoses. Although certain diseases such as melanoma
and lymphomas may ultimately spread to the breast and other organs, the term breast diseases refers to disorders of the breast that first arise in the breast. Benign breast diseases include a range of disorders that can cause breast pain, lumps, or nipple discharge in a patient of any age. The most common cause of benign nodularity, or lumpiness, and pain in the breast is fibrocystic change, followed by benign breast tumors and breast inflammation. Fibrocystic change is a hormonally related process that occurs in about 60 percent of premenopausal women and usually does not involve nipple discharge. Fibrocystic changes can be grouped into either epithelial hyperplasia, or overgrowth of cells lining the duct or lobule, or adenosis, which is enlargement of the lobules. The most common cause of a benign breast mass with possible discharge is a fibroadenoma. Other benign causes of breast pain, nodularity, and nipple discharge include breast abscesses and mastitis, infections of the breast tissue that often occur during breastfeeding, and naturally large pendulous breasts. Far less common causes include duct ectasia, sclerosing adenosis, phyllodes tumors, intraductal papillomas, fat necrosis, breast masses, and hidradenitis suppurativa. Keys to distinguishing among the possible causes of benign breast disease include careful history and examination of the lesion. Infectious causes are usually revealed by localized inflammation, warmth, and discharge. However, fibroadenomas can sometimes present more like cancerous breast masses and often require ultrasound imaging and biopsy to rule out cancer. Although benign breast conditions are by definition not cancerous, they can cause troubling symptoms and over time can increase a patient’s risk of developing breast cancer. The two main tests used to image questionable masses in the breast include mammograms and ultrasound. Mammograms are X-rays of the breast tissue that allow visualization of masses or calcifications. Macrocalcifications are usually due to deposits of calcium-rich plaques in the arteries due to aging and are considered benign. Microcalcifications are finer calcifications that can be suspicious for a cancerous or precancerous process depending on the distribution of the calcifications. Ultrasounds are useful in helping to determine if a mass is cystic, or fluid-filled, or solid. In most cases, it is not necessary to biopsy cysts, but
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masses usually require tissue biopsy to rule out cancer. Other diagnostic tests that may be performed are pathological analysis of breast nipple discharge and fine needle aspiration or core biopsies. Cancerous breast diseases include a spectrum of diseases and can present in many different ways. They differ from benign breast diseases because they have grown enough to invade surrounding tissues. The most common types of breast tumors are invasive adenocarcinomas, which are cancers of glandular tissue and can be divided into ductal or lobular adenocarcinomas. Precursor forms of these lesions that have not yet begun to invade beyond the duct or breast are referred to as ductal carcinoma in situ (DCIS) and lobular carcinoma in situ (LCIS). About 20 percent of new breast cancer cases are DCIS, while 80 percent are invasive ductal adenocarcinomas, and 10 percent are invasive lobular. Breast tumors can be further classified according to how the cells appear under the microscope to a trained pathologist, with medullary, tubular, and mucinous representing more benign types of tumors. The presentation of patients with breast cancer can vary depending on the type of breast cancer and the time at which they present. Some patients may present to their physician complaining of a lump discovered on breast exam. Other symptoms may include discharge, dimpling of the skin over the breast, retraction of the nipple, and redness or itchiness. Other patients may have a lesion detected by screening mammography or may be under close surveillance due to a strong family history. A minority of patients may present much later with advanced metastatic breast cancer, which can cause bone pain from bone metastasis, shortness of breath from malignant pleural effusions, or changes in balance, coordination, and cognition due to spread to the brain. All patients with a questionable mass in the breast usually undergo radiological imaging by mammography or ultrasound and almost always undergo a biopsy of the lesion as definitive diagnosis relies on examination of the tissue by a trained pathologist. Initial workup of the patient with breast cancer also involves a bone scan and other imaging tests to rule out spread of the disease to bone and other organs, as well as tests to determine the presence of certain receptors and mutations in the tumor that may influence treatment options.
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Prognosis of a patient’s breast cancer is related to a number of different factors. These factors include the age and menopausal status of the patient, as younger premenopausal ones tend to develop more aggressive and deadly tumors. Advanced stage of the disease, histologic and nuclear grade, as well as estrogen receptor and progesterone receptor status of the tumor affect prognosis. Presence of estrogen and progesterone receptors on the primary tumor usually improves prognosis because it affords more treatment options that specifically counteract the effect of hormones on tumor growth. Prognosis is also affected by the presence of the Her2/neu receptor on the primary tumor, which confers a worse prognosis. Certain histologic subtypes of breast cancer also carry a better prognosis, such as mucinous, medullary, and tubular carcinomas. There are a number of well-established risk factors for breast cancer, which mostly reflect a woman’s lifetime exposure to certain hormones, such as estrogen and progesterone. This is because growth and development of breast tissue is controlled in part by these hormones, as is the growth of certain breast cancers. Risk factors for breast cancer include family history, nulliparity or no history of pregnancy, early menarche or first menstruation, advanced age, and a personal history of breast cancer. There are also certain genetic mutations that can predispose women to developing breast cancer, such as mutations in the BRCA1 and BRCA2 genes. There are a number of other risk factors that remain controversial due to a lack of supporting evidence. These include use of hormone replacement therapy (HRT) in postmenopausal women, as well as exposure to certain drugs, alcohol, and chemicals. Women considering using HRT should discuss their individual risks and concerns with their physician before starting therapy. Because breast cancer can be effectively screened and treated in many cases, the American Cancer Society has issued guidelines for screening. These recommendations include yearly mammograms starting at age 40 and periodic clinical breast exams (CBE) about every three years for women starting in their 20s and increasing to every year for women over the age of 40. It is also recommended that women begin performing periodic self–breast exams in their 20s and report any change in breast health to their healthcare providers as soon as possible. Finally, women at increased risk should talk to their providers about beginning more rigorous screening regimens.
Treatment of breast cancer usually involves surgery, followed or preceded by radiation and/or systemic chemotherapy. Surgical options vary depending on how much of the breast is involved and whether the patient wishes to undergo breast reconstruction after the resection. Many surgical patients will also undergo a sentinel node biopsy, which is an intraoperative procedure in which blue dye is introduced into the breast lymphatics and allowed to drain the axillary lymph nodes, located under the armpit. The surgeon will remove the first couple of nodes identified in this manner and consult with a pathologist to determine if the cancer has spread through the lymphatics. If so, the surgeon will often continue on with a radical or modified radical mastectomy. If not, the patient is spared an overly invasive surgery. The extent of lymph node involvement will also help guide postsurgical management of the patient. If chemotherapy is given after the surgery, it is referred to as adjuvant, while chemotherapy given before surgery, to hopefully reduce the size of the tissue to be excised, is referred to as neoadjuvant. Depending on the extent of their surgery, some patients may choose to undergo reconstructive surgery of the breast through the use of implants or manipulation of certain muscles in the abdomen and back. In patients with certain mutations and receptors on their tumors, other more targeted therapies may exist. For example, patients with Her2/neu mutations may benefit from treatment with Herceptin® or Lapatinib®, drugs that target the Her2/neu receptor. Patients with estrogen and/or progesterone receptors on their tumors may benefit from treatment with antiestrogen drugs, such as Tamoxifen® and Raloxifen®. Avastin® is another targeted therapy for breast cancer that prevents blood vessel formation around the tumor by blocking the action of a protein called vascular endothelial growth factor. Follow-up of breast cancer patients is essential as patients have a higher lifetime risk of developing a recurrence or a second primary breast cancer. Most asymptomatic patients should continue to receive annual mammograms and breast exams from their physicians. SEE ALSO: Breast Cancer; Breast Implants/Breast Recon-
struction; Chemotherapy; Hormones; Women’s Health.
Bibliography. Mark N. Levine and Timothy Whelan,
“Adjuvant Chemotherapy for Breast Cancer—30 Years
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Later,” New England Journal of Medicine (v. 355/18, 2006); National Cancer Institute, “Breast Cancer Treatment for Health Professionals,” www.nci.nih.gov/cancertopics (cited April 2007); Richard J. Santen, “Benign Breast Disease,” www.UpToDate.com (cited April 2007). Jennifer Hellawell Cornell University
Breastfeeding Breastfeeding is the name for taking milk from the nipple of the mother or another woman producing milk. The process is known as suckling when it occurs among mammals. Breastfeeding is widely regarded as the safest and healthiest form of feeding a baby but other forms of nutrition are possible and may be preferable when the mother suffers from ill health or if genetic disorders or disease might be passed to the child. Certain social and cultural factors are also relevant to the decision as to whether or not to breastfeed. Milk is produced in the mammary glands, located in the breasts. Production is regulated by the hormonal system, which governs bodily changes and adaptations throughout the period of pregnancy. Although some milk is produced during pregnancy, it is only available in sufficient quantity for feeding after birth takes place. Generally, the amount of milk produced by the mammary glands is sufficient for the child or children but this is not automatically the case. When there is a mismatch, breast pumps may be used to stimulate production or remove excess milk, since in the latter case this can lead to engorgement, a sometimes painful condition. The breast pump is a manually or electrically operated machine and the milk produced may subsequently be stored in a suitable container and location and used to feed a child when the mother is not directly available. Although breastfeeding is a natural behavior and can help develop the bond between mother and child, it is not an instinctual behavior and will need to be learned by observation or teaching. The World Health Organization (WHO) argues as a matter of scientific principle that women should breastfeed their children exclusively, since this will
Breastfeeding is widely regarded as the best method of feeding a baby, with health benefits to both the mother and child.
promote recovery from illness while reducing the risks of diarrhea and pneumonia, among other diseases. The WHO stipulates that children should be breastfed exclusively, without being offered even water, let alone any other form of sustenance, should be fed on demand 24 hours a day, and the process should begin within one hour of birth. No artificial teats or pacifiers should be used. The mother is also protected to some extent, since breastfeeding reduces the woman’s risk of developing ovarian or breast cancer. In some countries, children may be breastfed until the age of 6 or 7, at least as a supplement to a solid diet. However, the WHO recommends exclusive breastfeeding for six months, which should be supplemented and then substituted by alternative nourishment at about the age of 2. In previous decades, aggressive marketing techniques of artificial milk preparations, particularly
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in the developing world, resulted in large numbers of children receiving inappropriate nourishment and suffering often severe health problems. Administered properly and in suitable situations, these forms of powdered milk may be used successfully but careful supervision and education of mothers is necessary. Although transmission of HIV from mother to child may occur in the womb and during the period of breastfeeding, with an apparently cumulatively increasing risk as the period of breastfeeding continues, new research suggests that exclusive breastfeeding suppresses transmission much more than mixed feeding. In countries with high rates of HIV occurrence, the benefits to the baby’s ability to resist disease have meant that only approximately half the number of deaths of babies occurred with exclusively breastfed babies compared to those whose diet was supplemented by artificial milk powder, porridge, and other foodstuffs. See also: AIDS; AIDS and Pregnancy; Infant and New-
born Care; Infant and Toddler Development; Infant and Toddler Health; Women’s Health. Bibliography. Naomi Baumslag and Dia L. Michels,
Milk, Money, and Madness: The Culture and Politics of Breastfeeding (Bergin and Garvey Trade, 1995); Hoosen M. Coovadia, et al., “Mother-to-Child Transmission of HIV-1 Infection during Exclusive Breastfeeding in the First Six Months of Life: an Intervention Cohort Study,” Lancet (v.369/9567, 2007). John Walsh Shinawatra University
Breast Implants/Breast Reconstruction Over the past 30 years, breast reconstruction and cosmetic breast augmentation surgery has undergone immense evolution, striving to improve the physical appearance and the quality of life of an individual. Breast reconstruction is typically performed in the surgical management of individuals with breast cancer and can entail the use of breast implants, whereas cosmetic breast augmentation is primarily done for purely cosmetic purposes.
In the surgical treatment of breast cancer, a mastectomy is typically performed, which entails the removal of breast tissue, relevant skin, and the nipple-areolar complex. Therefore, the primary aim of breast reconstruction following a mastectomy is to reconstruct the breast mound and the skin. A secondary objective is the reconstruction of the nipple-areola complex and possibly the neighboring breast to obtain a certain aesthetic symmetric outcome. The timing of breast reconstruction varies, being either immediate or delayed. Furthermore, various breast reconstruction techniques are performed and include nonautologous methods (fixed volume breast implants, breast expanders), combination of nonautologous and autologous methods (latissimus dorsi flap with breast implants), autogenous methods (deep inferior epigastric artery perforator, extended latissimus dorsi flap, superior gluteal artery perforator flap, and transverse rectus abdominus myocutaneous flap), and oncoplastic methods (breast lift or breast reduction techniques). In cosmetic breast augmentation surgery, a popular form of aesthetic enhancement and reconstruction entails the use of an artificial implant. Breast implants provide greater symmetry than alternative methods, are versatile in size and morphology, and provide natural aesthetics as compared to alternative methods. In 1962, plastic surgeons Cronin and Gerow invented silicone gel breast implants. Since then, over two million women in the United States and Canada have received these implants. Of those utilized, 20 to 30 percent were implemented for reconstruction and 70 to 80 percent were used for cosmetic augmentation. Because of reports of silicone leakage, other complications, and the need for further investigation, saline implants were developed and are also currently being utilized. These implants are composed of a salinefilled inner core with a cross-linked layer of silicone elastomer envelope that is in direct contact with the periprosthetic capsular tissue following implantation. These implants allow ease of surgical implementation and quick postoperative recovery. Plastic surgery has enjoyed much attention and wide success, especially in the past two decades when the surge of breast implantations gained particular attention. Many factors are at play in regards to patient outcome in reconstructive and cosmetic breast implant surgery. Time of surgery, patient acceptance, complication rates, and cost effectiveness are issues
that are thoroughly examined before surgical intervention is sought. Costs of such treatment vary between physicians. Complications Although breast implantation surgery has gained immense popularity, its success has been blemished by the various complications associated with the implant material. The most common complication consists of capsular contracture, which entails a tightening or squeezing of the scar or capsule on the implant, causing hardening of the breast and abnormal aesthetics. This condition is treated by additional surgery to remove the scar tissue or with implant replacement, resulting in additional costs. Usually, patients with capsular contracture are asymptomatic, but 10 percent develop symptoms and require surgical intervention. Furthermore, the risk of contracture has been noted to be greater in individuals undergoing postreconstruction radiotherapy. Intraoperative complications could occur, but excessive scarring, especially in patients who smoke, is a risk. Also, the risk of implant rupture is always a concern. However, while some manufacturers report the incidence of rupture in silicone implants to be as low as 0.2 to 1.1 percent, other investigators report up to 71 percent rupture rates. However, due to varying reports, the life-span of the implant remains inconclusive. In addition, concern has also arisen that the increasing trend of inappropriately trained plastic surgeons performing such surgeries may contribute to breast reconstruction/ implantation complications. With nearly four decades of silicone breast implantation, a slew of concerns regarding its safety and performance has arisen. Silicone breast implants have been approved to be used in the United States because they were on the market prior to the 1976 regulations set forth by the Food and Drug Administration (FDA). However, in 1991, the FDA required further information regarding this product, but it remained on the market during this data collection. In January 1992, the FDA issued a moratorium on the use of all silicone gel breast implants pending further review of reports of connective tissue disease and silicone bleeding. Later in 1992, the FDA restricted the use of silicone gel implants to clinical trials for a limited number of uses, such as reconstruction, congenital abnormality, and replacement of ruptured implants. Despite
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complications associated with silicone, this substance continues to be used, with over 2 million women in the United States and Canada having received implants with silicone as the gel core or envelope. The risk of silicone leakage to surrounding tissue or lymph nodes exists and can prove detrimental. Between 1985 and 1994, 90,000 adverse reactions in the United States were reported, which included 68 deaths associated with silicone gel-filled implants and three deaths attributed to saline-filled prosthesis with silicone envelopes. Conditions associated with silicone leakage include breast pain, fatigue, myalgias, arthralgias, hair loss, memory loss, autoimmune-like disorders, and delay of mammographic visualization of breast cancers. Furthermore, reoperation is necessary, which could leave unpleasant scarring and aesthetic quality that may further affect the psychological well-being of the patient. However, recent reports have contended that the risk of health-related problems associated with silicone use have been exaggerated. In addition, many contend that the risk of silicone leakage has decreased due to improved containment capsules. Although complications with silicone implants have been reported, they continue to be used. Companies continue to manufacture them because silicone is an affordable substance. Physicians prefer them because of the high profit margin and because they exhibit a more natural appearance and low capsular contracture rate than alternative material. SEE ALSO: Breast Cancer; Breast Diseases; Surgery. Bibliography. S. Ahmed, et al., “Breast Reconstruc-
tion,” British Medical Journal (v.330, 2005); M.E. Jenkins, H.I. Friedman, and A.F. Von Recum, “Breast Implants: Facts, Controversy, and Speculations for Future Research,” Journal of Investigative Surgery (v.9, 1996); A.R. Muzaffar and R.J. Rohrich, “The Silicone Gel-filled Breast Implant Controversy: An Update,” Plastic and Reconstructive Surgery (v.109, 2002); O.G. Robinson, E.L. Bradley, and D.S. Wilson, “Analysis of Explanted Silicone Implants: A Report of 300 Patients,” Annals of Plastic Surgery (v.34, 1995). S.L. Spear and C.J. Spittler, “Breast Reconstruction with Implants and Expanders,” Plastic and Reconstructive Surgery (v.107, 2001). Dino Samartzis, DSc, MSc, Dip. EBHC Harvard University and Erasmus University
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Breathing Problems Breathing problems may occur as the result of a disease process affecting one or more of the body’s systems. Dysfunction associated with any of the following may lead to difficulty breathing or dyspnea (shortness of breath): • the musculoskeletal system, including dysfunction of muscles and bones that move in order to facilitate breathing • the respiratory system, including foreign body obstruction, infection, irritation, lung diseases, and hypoxia (low environmental oxygen) • the cardiovascular system, including infection, myocardial infarction, congestive heart failure, and congenital valve problems • the nervous system, including problems of the body’s breathing center, and diseases of nerves that innervate respiratory muscles Some causes of dyspnea are not easily categorized into a body system. For example, emotional factors, such as anxiety, may play a role. The treatment for a person experiencing breathing problems must be tailored to the cause, which is often multifactorial. Breathing problems involving the musculoskeletal system are familiar to those who engage in sports. The major muscles used during breathing are the diaphragm and the external intercostals. The diaphragm is located below the lungs, within the abdominal cavity, and contracts during inhalation to expand the thoracic cavity and allow for necessary lung expansion. If the diaphragm or external intercostal muscles are damaged, then the accessory breathing muscles (the sternocleidomastoid, the platysma, and the strap muscles of the neck) are utilized. It is not uncommon for these muscles to pull or tear with excessive use or strain such as during sports. Breathing will be difficult and often painful if these muscles are damaged. Similarly, if ribs are fractured from trauma, the expansion of the thoracic cavity will be inhibited during inhalation and cause problems in lung expansion due to pain occurring with inhalation. Rib pain may continue for weeks after the initial trauma because of inflammation. Body shape plays a role in the amount of work needed to breathe. Some individuals have a skeletal structure that may alter their ability to breathe. For example, a person with severe scoliosis (lateral curva-
ture of the spine) may have difficulty as the curvature of the spine may decrease the volume of the thoracic cavity, and, hence, decrease the potential for lung expansion. Obese patients may also experience breathing problems because of an increased burden on their cardiovascular and respiratory systems, as well as the pressure from excess body weight on the ribs, which move with respiration. The respiratory system includes the nose, mouth, nasopharynx, oropharynx, pharynx, larynx, trachea, bronchi, and lungs. Dysfunction of any one of these parts may disrupt the system’s ability to perform to capacity. For example, a congested or broken nose will limit the amount of air that enters into the system, as will infected and swollen tonsils. Children with strep throat may experience this sort of dyspnea due to congestion. Foreign objects may also block the nose or throat and hinder the flow of air into the lungs. Often, toddlers, if given the opportunity, will put peas, peanuts, candy, marbles, or other small objects into their noses. It is also not uncommon for people of all ages to get a piece of food lodged in their throat, serving as a barrier to air entering the lungs. Two main categories of disorders affect the lungs: obstructive and restrictive lung disease. Obstructive disease processes such as asthma, chronic obstructive pulmonary disease (COPD), emphysema, and bronchitis make exhalation difficult because of obstructed airflow out of the respiratory system. For example, in asthma, the airways may be swollen and inflamed, which physically decreases the size of the airway. In general, obstructive diseases are worsened, and often caused by, cigarette smoking. The nicotine in cigarette smoke is not only a carcinogen but also an irritant to the entire respiratory tract, from the nose and mouth through to the lungs and may cause problems throughout. Despite the wellknown link between cigarettes and lung cancer, many people continue to smoke, being addicted to chemicals in the cigarettes. In countries that rely upon wood burning fires for cooking and household heating, people may develop emphysema despite the fact that they have never smoked. This is due to being in enclosed areas where the fire is located. Restrictive disease processes, on the other hand, do not result in exhalation difficulty but rather in problems inhaling as a result of decreased lung volume.
Pneumonia is a good example of a restrictive process. Interstitial mucus accumulates in pneumonia (often caused by the bacteria Streptococcus pneumoniae) decreasing available lung space for air. Lung cancer is also considered a restrictive process. Lung cancer may either originate in the lungs, such as adenocarcinoma, or metastasize to the lungs from another place in the body (e.g., from cancer in the breast). Further examples of restrictive lung disease include pulmonary edema, pleural effusion, pneumothorax (air in the pleural cavity), sarcoidosis (a systemic disease that results in interstitial fibrosis), and other bacterial, viral, and fungal infections. Immunocompromised individuals (e.g., HIV/AIDS patients), in particular, are more susceptible to a decreased lung volume from infection, as their immune system is less capable of fighting off foreign bodies. As the heart is responsible for pumping blood to and from the lungs, to obtain and exchange oxygen, anything that inhibits the heart from maintaining adequate circulation throughout the body will manifest, in part, with dyspnea. Congestive heart failure (CHF) results when the heart fails to adequately pump blood throughout the body. When circulation ceases to be maintained, patients with CHF will have noticeable shortness of breath as well as edema from the overload of fluid in the lungs. CHF may occur as a result of a myocardial infarction (heart attack). Patients who experience a heart attack may also have secondary pulmonary edema. Multiple heart attacks may lead to ischemic heart disease and a further decline in breathing ability. Cardiomyopathy (a disease of heart muscle) will also decrease the heart’s pumping capacity. This may be the result of alcohol consumption or may present as a congenital defect because of a genetic predisposition. Other congenital problems are valve problems, transposed vessels, and holes in the chambers of the heart. These may cause dyspnea as well as more serious problems. In general, disorders or diseases affecting the heart will result in breathing problems secondary to circulation problems. Disturbances within the nervous system may affect the body’s primary breathing control center. Located in the medulla, the primary breathing control center is an integral part of the central nervous system (CNS). Trauma, cancer, infection, or lack of blood flow (vascular insufficiency) are all possible causes of
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a pathological condition within the medulla. Neurologic problems may also cause secondary dyspnea. For example, a focal mononeuropathy (a neuropathy or disease affecting a single nerve) involving the phrenic nerve will result in an inability of the diaphragm to contract during inhalation, which will inhibit lung expansion. Within the nervous system, there may be a malfunction in the communication between nerve cells (neurons). In myasthenia gravis, an autoimmune neuromuscular disease, this impaired communication results in severe muscle weakness and muscle fatigue. Often, the muscles of inspiration are among those affected, so a patient with myasthenia gravis may also have trouble breathing. Other diseases of the nervous system that hinder respiration include multiple sclerosis and amyotrophic lateral sclerosis (ALS or Lou Gehrig’s disease). A person with anxiety may exhibit respiratory difficulty, often breathing rapidly, yet not taking deep breaths. A person undergoing a panic attack may also suffer from rapid breathing (tachypnea) as well as a sensation of smothering or being unable to get a breath in. Panic attacks generally last less than 10 minutes; however, they can be extremely frightening. The treatment is usually long term, involving medications and behavioral counseling. When not having a panic attack, patients may have completely normal Xrays and pulmonary function tests. Patients with breathing disorders need comprehensive evaluation and diagnostic testing based on history and physical exam findings. At times, external influences on the body such as trauma, hypothermia, and hyperthermia can result in breathing problems. Fortunately, many causes of breathing problems may be at least controlled, and even a slight improvement in the ability to breathe may provide comfort to the patient. SEE ALSO: Asbestos/Asbestosis; Asthma; Bacterial Infec-
tions; Bronchitis; Emphysema; Exercise Treadmill Test; Heart Attack; Lung Cancer; National Heart, Lung, and Blood Institute (NHLBI); Pneumonia; Pulmonary Fibrosis; Pulmonology; Smoking; Tuberculosis. BIBLIOGRAPHY. Abul Abbas, Nelson Fausto, and Vinay
Kumar, eds., Pathologic Basis of Disease, 7th ed. (Elsevier Saunders, 2005); Eugene Braunwald, et al., eds., Harrison’s Principles of Internal Medicine, 16th ed. (McGraw-Hill,
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2005); Arthur F. Dalley and Keith L. Moore, eds., Clinically Oriented Anatomy, 5th ed. (Lippincott Williams & Wilkins, 2006). Gautam J. Desai, D.O. Kieara A. Conway Kansas City University of Medicine and Biosciences
Breech Birth Most babies are born head first because they are in a head-down position in the mother’s uterus. When a baby is positioned so that the feet are first to exit the womb, it is called a breech birth or breech baby. About 3 to 4 percent of babies are in a breech presentation at the onset of labor. Many babies are breech early in pregnancy, but most of them turn to the headfirst position near the end of the pregnancy. Babies who are born early are more likely to be breech. In the case of twins or triplets, the likelihood of a breech baby is increased. Abnormal levels of amniotic fluid around the baby may also result in a breech birth. As the due date approaches, a physician can determine if the fetus is breech by performing a physical exam, an ultrasound, or both. There are many complications associated with a breech birth delivered vaginally, and therefore, physicians typically suggest cesarean delivery, also called a C-section. The risks involved with cesarean delivery include bleeding, infection, and a longer hospital stay for both the mother and her baby. A baby who is breech may be very small or may have birth defects. Breech babies may also have accidents during delivery that can damage the umbilical cord, leading to asphyxia, a condition caused by inadequate oxygen intake. When the umbilical cord becomes compressed, there is diminished oxygen flow to the baby. The baby must be delivered immediately (usually by C-section) so that he or she can breathe. If there is a delay in delivery and oxygen deprivation is prolonged, the brain can be damaged, leaving the baby with permanent neurological damage or even causing death. In some cases, a breech birth may even cause the death of the mother, baby, or both.
To prevent harm to the fetus and/or mother, it is important for pregnant women to see a doctor early and regularly. This way, the physician can tell if the baby is breech and can help plan the necessary course of action. Some doctors plan to deliver the baby by C-section, while others give their patients exercises to do at home that may help turn the baby to the headfirst position. For women who prefer a normal vaginal delivery, their physician may use the external cephalic version procedure to try to turn the baby from breech position to vertex (head-down) position while the fetus is still in the uterus. The physician will use his or her hands on the outside of the expecting mother’s abdomen to try to orient the baby, so that the head is first to exit the vagina. External cephalic version is performed at the end of pregnancy, after about 37 weeks of gestation. The success rate of external cephalic version depends on several factors, with an average success rate of about 65 percent. Even if the procedure works at first, there is still a chance that the baby will turn back around to the breech position. SEE ALSO: Breathing Problems; Fraternal Twins; Obstet-
rics; Perinatologist; Prenatal Care.
Bibliography. G.J. Hofmeyr and M.E. Hannah, “Planned
Caesarean Section for Term Breech Delivery,” Cochrane Database of Systematic Reviews (Issue 2, 2003); Robert Kelly, “External Cephalic Version,” American Family Physician (September 1998); Halie Shalley, Williams Obstetrics: Breech Presentation and Delivery (McGraw-Hill, 2006). Navid Ezra University of California, Los Angeles
Bronchitis The term bronchitis refers to a self-limited condition caused by infection and/or inflammation of the bronchial tree. Bronchi are tube-like structures that serve to communicate oxygenated air to the lung during inhalation and remove debris and products of metabolism (e.g., carbon dioxide) during exhalation. The origin of the bronchial tree is the trachea (main breathing tube), which branches into the right and left main stem bronchi. These main stem bronchi repeat-
edly branch into smaller and smaller bronchi, allowing for dispersion of oxygenated air to the periphery of the lung. Some experts have made the analogy of an upside-down tree trunk with branches to the branching of the bronchi within the human lung. Bronchitis results from inflammation and/or infection of the epithelial cell lining of the bronchial tree by viruses, bacteria, or following inhalation of irritant gases such as those associated with home fires, mixing of bleach and ammonia in a closed space, chemical fires, and so forth. These infected epithelial cells frequently become detached from the surface of the lining of the bronchi and may be coughed up by the patient in the form of sputum (phlegm). Symptoms of bronchitis include cough, which may be a nonproductive (dry) cough or a cough productive of sputum (phlegm); mild to moderate chest pain (behind the breastbone and noted particularly with repeated coughing); and rarely, mild shortness of breath with or without wheezing. Bronchitis may be acute or chronic. It has been estimated that 10 percent of nonsmoking adults will experience at least one episode of bronchitis per year. Tobacco smokers are at increased risk to develop repeated episodes of bronchitis and, with long-term smoking, a condition known as chronic bronchitis may develop. The diagnosis of chronic bronchitis is made when cough and sputum (phlegm) production occurs on most days of the month for at least three months of the year, for two consecutive years. During the early days of acute bronchitis, symptoms may be indistinguishable from any other respiratory tract infection. The duration of the cough associated with acute bronchitis persists for at least five days and may last for as long as three to four weeks. The differential diagnosis of acute bronchitis includes postnasal drip, exacerbation of asthma, or chronic obstructive pulmonary disease (COPD) as well as other types of pulmonary disease including influenza or pneumonia. A large number of viruses have been shown to cause acute bronchitis; in addition, a number of bacterial species may cause bronchitis. Treatment with antibiotics is generally not recommended and will only be effective when cultures or testing for antibodies has identified specific bacterial causes of bronchitis; specific antiviral medications may be indicated for the treatment of bronchitis caused by the
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influenza virus (antiviral therapies have been shown to reduce the length of symptoms and prompt faster return to usual activities). Diagnosis and Treatment Because bronchitis is typically self-limited, the physical examination of the patient with bronchitis should show cough but no fever, no evidence of fast breathing, no evidence of fast heart rate, and no difficulty with oxygenation. Deviation from this presentation may occur if the patient with bronchitis is also experiencing an exacerbation of an underlying respiratory condition such as asthma or COPD. Diagnostic studies such as chest X-ray, arterial blood gas, and sputum culture are typically not warranted. Only when the physician is concerned that the symptoms may be caused by an alternative diagnosis should these studies be obtained. To do so otherwise has not been proven to be cost-effective. Supportive care is also traditionally offered because this condition is self-limited. Supportive care consists of encouraging the patient to expand fluid intake, as needed use of analgesics such as acetaminophen, ibuprofen, or naproxen (when not contraindicated), and rest. Cough suppressants are not routinely recommended as prospective studies have shown no benefit when these agents were compared to placebo. Antibiotics, mucolytics, and bronchodilators (breathing medications) should not be routinely administered as they have not been proven to alter the time to resolution of symptoms or return to normal activities. Exceptions to the above include cases of bronchitis occurring in patients with underlying lung diseases which may be exacerbated by the acute bronchitis. Examples of such underlying lung conditions include but are not limited to asthma, COPD, pulmonary fibrosis, and sarcoidosis. In such cases, consideration may be given to the use of bronchodilators, corticosteroids, antibiotics, and cough suppressants, on a case-by-case basis. Input from a pulmonologist may be helpful. In the event that a patient suspected of having uncomplicated, acute bronchitis does not respond to supportive care within the usual time frame and has protracted symptoms, consideration should be given to consultation with a pulmonologist and performance of a chest X-ray, blood tests, lung function testing, and possibly cultures for microorganisms.
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Conditions that may masquerade as uncomplicated bronchitis include pertussis (whooping cough), asthma, COPD, lung cancer, pneumonia, inhaled foreign body, or infectious processes including but not limited to tuberculosis, fungal infection, or other malignancy. If one of these conditions is diagnosed following appropriate studies, definitive therapy should be applied. In recent years, development of evidence-based guidelines has become common practice. These guidelines are formulated by groups of content experts following an exhaustive review of prospective, controlled clinical studies of patients with the disease under consideration. The evidence supporting application of or withholding of treatment is rated according to the level of evidence from the literature that supports the recommendation. The American College of Chest Physicians has published two sets of evidence-based guidelines on acute bronchitis, the first in 2001 and the second in 2006. These guidelines should be consulted for specific levels of recommendation of the treatments discussed herein. SEE ALSO: Asthma; Chronic Obstructive Pulmonary Dis-
ease (COPD); Pneumonia; Pulmonology.
Bibliography. S.S. Braman, “Chronic Cough Due to
Acute Bronchitis. ACCP Evidence-Based Clinical Practice Guidelines,” Chest (v.129/Suppl., 2006); R. Gonzales, et al., “Principles of Appropriate Antibiotic Use for Treatment of Uncomplicated Acute Bronchitis,” Annals of Internal Medicine (v.134, 2001). Sandra K. Willsie, D.O. Kansas City University
Bross, Irwin D.J. ����������� (1921–2004) Irwin D.J. Bross was an American public health advocate and biostatistician who devised methods for analyzing vehicle crash injury cause and effect, and conducted clinical studies of the relationship between low-level radiation exposure and cancer. In the late 1970s, Bross showed that people exposed to low-level radiation at work or as a result of frequent medical X-rays were 10 times more likely to develop
leukemia than had been thought. Bross also spoke out against animal testing for medical purposes. As director of biostatistics at Roswell Park Memorial Institute in Buffalo, New York, Bross studied the increasing rates of leukemia in the 1970s. His sample consisted of 16 million people from New York, Maryland, and Minnesota. Bross took into account factors as different as health history, employment, residential history, family background, cause of death for parents and grandparents, exposure to farm animals, and pet ownership. Bross concluded that the main cause of the rising rates of leukemia was medical radiation in the form of diagnostic medical X-rays. The nine-year study also indicated that children who were subjected at various stages in utero to X-ray exposures of under 1 rem were up to 50 percent more likely to die from leukemia. The survey was initially sponsored by the government-run National Cancer Institute (NCI). Its final data confirmed the findings of the British epidemiologist Alice Stewart contained in an earlier study. In 1977, Bross published his study in the prestigious New England Journal of Medicine, despite the fact that it had been peer reviewed by government scientists who, according to him, were deliberately placed on the NCI board to bring his research into disrepute. Soon after the publication of the study, the NCI discontinued its funding. After that experience, Bross became a strong critic of what he called “official science,” saying that the government purposefully neglects new evidence in medical research that goes against previously established conclusions and investments in possible treatments. He publicly accused “[t]he big science Federal agencies . . . , their industrial constituencies and their allies in the scientific and medical communities” of “lying to the public about the hazards of low-level ionizing radiation for twenty-five years.” Bross’s later research focused on revising the health data on a sample of 50,000 of the estimated 250,000 personnel exposed to radiation because of their employment in the nuclear testing program in the 1950s. He concluded that 500 had died from radiation-induced illnesses. SEE ALSO: Cancer (General); Radiation Exposure. Bibliography.� Irwin D.J. Bross, Crimes of Official Science: A Casebook (Biomedical Metatechnology Press,
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1988); Irwin D. J. Bross, Scientific Strategies to Save Your Life, (Marcel Dekker, 1981).
eggs and sperm and has caused some concern about the social implications of sex selection.
Luca Prono Independent Scholar
SEE ALSO: American Fertility Association (AFA); In Vitro;
Infertility; Pregnancy.
Bibliography. Steve Connor and Maxine Frith, “IVF
Brown, Louise (1978– ) When she was delivered by caesarean section at Oldham Hospital in Lancashire, England, on July 25, 1978, Louise Joy Brown became the first infant conceived using in vitro fertilization (IVF). After numerous attempts to impregnate Lesley Brown, Louise’s mother, physicians tried fertilizing her eggs in a Petri dish before implanting a two-and-a-half-day-old embryo. Dubbed a “test-tube baby” by the press, Louise Brown was subjected to media attention that has persisted, especially in the wake of the July 2006 announcement that she was pregnant. It took 12 years for British physiologist Robert Edwards and gynecologist Patrick Steptoe to develop the in vitro fertilization procedure in which eggs are fertilized with sperm in a lab and the resulting embryos are transferred to a woman’s uterus two to six days later. It often takes multiple cycles of IVF to produce pregnancy. Initially developed as a technique for couples experiencing infertility (which is generally medically defined as the inability to conceive during one year of trying), IVF is now one of several assisted reproductive technologies (ARTs). IVF has expanded options for lesbian and gay couples, women undergoing treatment for cancer or other serious illnesses who can have their eggs extracted and frozen for later IVF, those who wish to postpone pregnancy, and parents interested in screening for genetic abnormalities or the sex, because a number of tests can be done before implanting embryos. As of June 2006, more than 3 million IVF babies had been born worldwide. While considered a medical miracle to some, the cost of IVF—well over $10,000 per cycle—makes it only accessible to patients with comprehensive medical insurance or personal financial resources. Wellpublicized multiple births have also caused concern about the medical dangers and expense associated with multifetus pregnancies and postnatal care. Likewise, the invention of IVF has spurred a market in
Boom Produces More than 3 Million Babies around World,” The Independent (June 22, 2006); Nancy Gibbs, “Brave New Baby,” Time (March 31, 2003); Robin Marantz Henig, Pandora’s Baby: How the First Test Tube Babies Sparked the Reproductive Revolution (Houghton, 2004). Christine L. Manganaro University of Minnesota
Brown, Michael Stuart (1941– ) Michael Stuart Brown is an American geneticist who, along with Joseph L. Goldstein, was awarded the Nobel Prize in Medicine in 1985 for a description of the regulation of cholesterol metabolism. Brown was born to Harvey Brown, a textile salesman, and Evelyn Brown, a housewife, on April 13, 1941, in Brooklyn, New York. When Brown was 11 years old, the family moved to a suburb of Philadelphia, where Brown attended Cheltenham High School. While still a teenager, Brown developed the two main interests that would characterize his career: science and writing. He combined these two interests while a student at the University of Pennsylvania, graduating in chemistry in 1962 and working for the student newspaper, the Daily Pennsylvanian. In 1966, Brown obtained his M.D. degree from the School of Medicine of the University of Pennsylvania. He spent the next two years as intern and resident in Internal Medicine at the Massachusetts General Hospital in Boston, where he met Joseph L. Goldstein, with whom he would establish a long-term scientific collaboration. From 1968 to 1971, Brown worked at the National Institutes of Health, initially as a clinical associate in gastroenterology and hereditary disease, and then joining the Laboratory of Biochemistry, where he became interested in enzymology and metabolic regulation. In 1971, Brown became a member of the division of gastroenterology in the Department of Internal Medicine
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at the University of Texas Southwestern Medical School in Dallas and was joined the following year by Goldstein. Brown became a professor in 1976 and, a year later, he was appointed director of the Southwestern Medical School’s Center for Genetic Disease. Brown and Goldstein fully resumed their scientific collaboration, researching, in particular, the causes of hypercholesterolemia. They discovered that human cells have low-density lipoprotein (LDL) receptors that remove cholesterol from blood. When LDL receptors are not present in sufficient numbers, individuals develop hypercholesterolemia, thus becoming at risk for cholesterol-related diseases. Brown and Goldstein’s research led to the development of statin drugs, the cholesterol-lowering compounds that reduce the risk of heart diseases and strokes. In addition to the Nobel Prize, Brown has been awarded many other important honors, including the National Medal of Science in 1988. He is a member of important scientific institutions, including the National Academy of Sciences of the United States, the American Academy of Arts and Sciences, and the American Board of Internal Medicine, and he is a fellow of the American College of Physicians. SEE ALSO: Cholesterol; Genetics. Bibliography. Michael Brown, “Biography,” in Wilhelm
Oldelberg, ed., The Nobel Prizes 1985 (Nobel Foundation, 1986): “Michael S. Brown: The Nobel Prize in Physiology or Medicine 1985,” Nobelprize.org, www.nobelprize.org/ nobel_prizes/medicine/laureates/1985/brown-bio.html (cited August 2007). Luca Prono Independent Scholar
heat through muscle contraction or shivering. Moreover, they have less thermal insulation in the form of white adipose tissue to protect them from the cold. To compensate for these deficits, newborns have stores of brown adipose tissue in their necks and backs. While brown fat does not offer the thermal insulation of white fat, it does allow the newborn to generate heat through a process called nonshivering thermogenesis. Human cells have mitochondria that generate chemical energy in the form of adenosine triphosphate (ATP). The mitochondria in brown fat cells, however, have a special mechanism to create heat energy instead of chemical energy to warm the body. When the newborn is exposed to cold, thyroid-stimulating hormone (TSH) and epinephrine are released in the body. These hormones initiate biochemical pathways that activate nonshivering thermogenesis in the mitochondria of brown fat cells, allowing them to produce heat instead of ATP. Brown fat cells are better able to undergo nonshivering thermogenesis than white fat cells because they have a greater number of mitochondria and because they have a greater amount of thermogenin (also called uncoupling protein 1, UCP1), a protein required for mitochondria to switch from making ATP to heat. Brown fat is active at birth and then soon transforms to white fat during normal newborn development. Maternal and fetal malnutrition may decrease the amount of brown fat available in infancy. See also: Hypothermia���������������������������������� ; Infant and Newborn Care; Infant
and Toddler Development; Infant and Toddler Health.
Bibliography. Melinda K. Loughead, Jeffrey L. Loughead,
and Mary Jane Reinhart, “Incidence and Physiologic Characteristics of Hypothermia in the Very Low Birth Weight Infant,” Pediatric Nursing (v.23/1, 1997); Patti J. Thureen and William W. Hay, eds., Neonatal Nutrition and Metabolism, 2nd ed. (Cambridge University Press, 2006);
Brown Fat Brown fat is specialized adipose tissue found in the newborn that allows it to generate heat to maintain its body temperature. Newborns are at a greater risk for hypothermia than older humans. They have a larger surface area-to-volume ratio and cannot warm themselves on their own by seeking a warmer environment, covering themselves, or generating significant
Jason Vassy Washington University in St. Louis
Brunei Brunei, also called Brunei Darussalam, is a small country on the northwest coast of the island of Borneo in
Bulgaria
the South China Sea; it shares that island with Malaysia. Brunei is a sultanate ruled by the same family since the 15th century. It derives enormous wealth from rich petroleum and natural gas fields, as well as from strong foreign investment, and has one of the highest per capita Gross Domestic Products in Asia. However, leaders worry that outside influences on this strictly Islamic country might soon undermine social cohesion. The population is estimated at 374,500, growing at 1.81 percent annually. Life expectancy is about 75 years for males and 77 years for females. Infant mortality is 8.80 deaths per 1,000 live births; under-5 mortality is 9.80 deaths per 1,000. With government-subsidized housing, food, education, and medical care, there is no real problem of poverty in Brunei. All but 0.9 percent of the workforce are in the industrial or services sectors. While communicable diseases were once major causes of poor heath and death within the sultanate, they are now practically nonexistent. The country has a robust surveillance system to spot emerging health threats, including new diseases like severe acute respiratory syndrome (SARS) and avian flu. There is almost universal immunization for the chief diseases of childhood, and Brunei is polio-free. Both morbidity and mortality in Brunei are driven primarily by noncommunicable diseases and disorders. Leading causes of inpatient morbidity are pregnancy, asthma, gastrointestinal disorders, acute respiratory infections, heart and circulatory diseases, and diabetes. The leading causes of morbidity in Brunei are cancers, heart disease, diabetes, cerebrovascular diseases, respiratory diseases, hypertensive diseases, traffic accidents, influenza and pneumonia, and congenital disorders. Brunei has a well-integrated network of healthcare facilities under a centralized Ministry of Health. There are four public hospitals and one private facility; five medical centers; 15 regional health centers; 10 health clinics; 15 mother-and-child wellness clinics; 13 “traveling” health clinics; and five “flying” health clinics that reach the most isolated communities on a regular basis. There are 463 physicians, 1,925 nurses, and 68 dentists working within the country. Healthcare is free to all residents. See also: Healthcare, Asia and Oceania. Bibliography. Central Intelligence Agency, “Brunei,”
World Factbook, www.cia.gov (cited June 2007); United
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Nations Children’s Fund (UNICEF), “Brunei—Statistics,” www.unicef.org (cited June 2007); World Health Organization, www.who.int (cited June 2007). Heather K. Michon Independent Scholar
Bulgaria A member of the Soviet bloc, Bulgaria is still in the process of transitioning from a state-controlled system to a democratic, free market economy. Inflation (5 percent) and unemployment (11.5 percent) have combined with corruption and organized crime to drain important resources from the government that are needed for healthcare and other social programs. Bulgaria ranks 89th in world incomes, with a per capita income of $9,600. The Gini coefficient for Bulgaria is 31.9 percent, and income is somewhat unequal, with the richest 10 percent of the population claiming 22.8 percent of resources while the poorest 10 percent share 4.4 percent. Eleven percent of the population are engaged in agriculture. Approximately 13.4 percent of Bulgarians live in poverty, and 5 percent of the population live on less than $1 a day. By some estimates, 90 percent of the population is classified as low-income. Women and children are particularly vulnerable, and 65 percent of female-headed families live in abject poverty. Elderly women are three times more likely than men to be poor. The Bulgarian government designates 12 percent of the total budget and 7.5 percent of the Gross Domestic Product (GDP) for health expenditures. Some $573 (international dollars) per capita are used to fund government healthcare programs. Of all government expenses, 54.5 percent derive from government subsidies. Over half of that amount (51.6 percent) is earmarked for social security. The private sector furnishes 45.5 percent of health expenditures, and outof-pocket expenses account for 98.40 percent of that amount. There are 3.56 physicians, 3.75 nurses, 0.55 midwives, 0.82 dentists, and 0.13 pharmacists per 1,000 population in Bulgaria. According to the Public Health Act, all Bulgarians have equal rights within the healthcare system. Special programs deal with the healthcare needs of
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pregnant women and mothers with children who receive public assistance. Overseeing the health needs of children is the joint responsibility of the Minister of Health, the Minister of Education and Science, and the Minister of Labor and Social Policy. Specific programs are administered by local communities. Social security is financed by contributions from employers and employees supplemented by the government. Despite legal equality, informal payments for healthcare are a way of life in Bulgaria, and gifts and cash payments are considered universal for operations, childbirth, and life-threatening situations. Such payments are expected and may be demanded in hospitals and elite facilities and by noted physicians. Medical professionals depend on such payments to supplement income, but they can present problems for those with few resources who are able to receive quality care only through submission of such payments. Among the population of 7,385,367, life expectancy is 72.3 years. Females tend to outlive males by about seven years. Literacy is high at 98.6 percent, and 90 percent of Bulgarian children are enrolled in primary school. All males and 97.8 percent of females are enrolled in secondary school. One hundred percent of the population has access to safe drinking water and improved sanitation. Bulgarian women give birth to an average of 1.38 children each, and 42 percent use birth control. Only 1 percent of all births occurs outside the presence of a skilled attendant. The adjusted maternal mortality rate is 32 deaths per 100,000 live births. At 19.85 deaths per 1,000 live births, infant mortality is high; Bulgaria ranks 115th in infant mortality among nations of the world. However, the government successfully reduced both infant and under-5 mortality between 1990 and 2004. Infant mortality declined from 15 to 12 deaths per 1,000 live births, and under-5 mortality dropped from 18 to 15 deaths per 1,000 live births. A tenth of all infants are underweight at birth. The government subsidizes all required immunizations. Consequently, 98 percent of infants have been vaccinated against tuberculosis; 95 percent against diphtheria, pertussis, and tetanus (DPT1 and DPT3) and measles; and 94 percent against polio and hepatitis B. A series of health interviews conducted in March 2001 by the National Statistical Institute (NDI) found that 35.9 percent of men and 44.4 percent of Bulgarian women admit to having impaired health. Most health
experts insist that many health problems are caused by lifestyle and behavior, citing unhealthy diets and poor working conditions as major causes of ill health. The HIV/AIDS adult prevalence rate is in low in Bulgaria at less than 0.1 percent. Around 346 people are living with the disease, which has claimed 100 Bulgarians. Air pollution is a major threat in Bulgaria, and the rivers are polluted with raw sewage, heavy metals, and detergent. Soil contaminated with heavy metals and industrial wastes also poses health risks. Bulgaria experienced an outbreak of severe acute respiratory syndrome (SARS) in spring 2003. See also: Greece; Romania; Turkey. Bibliography. Dina Balabanova and Martin McKee,
“Understanding Informal Payments for Health Care: The Example of Bulgaria,” Health Policy (v.62/3, 2002); Central Intelligence Agency, “Bulgaria,” World Factbook, www.cia. gov (cited December 2006); Commission on the Status of Women, “Bulgaria,” www.un.org/womenwatch (cited December 2006); Glenn E. Curtis, Bulgaria: A Country Study (Federal Research Division, Library of Congress, 1993); Martin A. Levin and Martin Shapiro, eds., Transatlantic Policymaking in an Age of Austerity: Diversity and Drift (Georgetown University Press, 2004); United Nations Children’s Fund (UNICEF), “Bulgaria,” www.unicef.org (cited December 2006); Social Security Administration, “Bulgaria,” www.ssa.gov (cited December 2006); Social Watch, “Bulgaria,” www.socialwatch.org (cited December 2006); World Bank, “Bulgaria Data Profile,” devdata.worldbank. org (cited December 2006); World Health Organization, “Bulgaria,” www.who.int (cited December 2006). Elizabeth R. Purdy, Ph.D. Independent Scholar
Bulimia Bulimia nervosa is a complex eating disorder characterized by episodes of eating large quantities of food (bingeing) and then engaging in purging or other methods to compensate for the binge eating. The term bulimia is derived from Greek to mean “ox hunger,” thus giving a concise description of one of the disorder’s key clinical features: excessive food consumption.
Methods of purging typically include self-induced vomiting and abusing laxatives and/or diuretics. Fasting or excessive exercise are “nonpurging,” but they are, nonetheless, compensatory behaviors. Another significant feature of bulimia nervosa is a strong dissatisfaction with the individual’s body weight and shape. Eating disorders such as bulimia nervosa and anorexia nervosa primarily affect women; an estimated 1 to 2 million women are afflicted with this disorder in the United States alone. If undiagnosed, bulimia nervosa can lead to serious medical consequences. The Diagnostic and Statistical Manual of Mental Disorders, 4th edition (DSM-IV), published by the American Psychiatric Association, establishes criteria used by clinicians in diagnosing and distinguishing eating disorders. Unlike anorexia nervosa, there are explicit criteria for both frequency and duration for a diagnosis of bulimia nervosa. The DSM-IV criteria for bulimia nervosa include recurrent episodes of binge eating accompanied by a feeling of a loss of control (binge eating constitutes a consumption of larger-than-normal quantities of food in a discrete period); recurrent compensatory measures to avoid gaining weight post-binge that either involve purging (e.g., self-induced vomiting) or nonpurging activities (e.g., excessive exercise). The bingeing and purging behaviors occur a minimum of two times a week for a duration of three months; self-evaluation is disproportionately influenced by body shape and weight. In addition, these disturbances do not occur during episodes of anorexia nervosa. Bulimia nervosa is a relatively “new” disorder; there are no data for bulimia nervosa prior to 1970. Like anorexia nervosa, bulimia nervosa is significantly more common in women than in men, affecting 1 to 3 percent of young females in their lifetime. Also, it is more common in developed countries such as the United States and has increased in prevalence over the last 50 years. Recent data from a nationally representative study of eating disorders in the United States report a lifetime prevalence of bulimia nervosa to be 1.5 percent in women and 0.5 percent in men. Peak onset, or beginning, of eating disorders typically occurs at either 14 or 18 years of age. While research has yet to reach agreement as to the cause of eating disorders, cultural pressures such as an overidealization of thinness and a demonstrated prejudice against obesity have been implicated. As in
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anorexia nervosa, a number of factors have been observed to be associated with bulimic behavior: professions or artistic pursuits that involve a public display of the body (e.g., ballet, modeling); a history of dieting; biological deficiencies such as serotonin deficiency; and a history of physical or sexual abuse. Similar to anorexia nervosa, bulimia nervosa is classified into two subtypes: purging subtype and nonpurging subtype. The bulimia nervosa purging subtype involves the use of purging methods such as self-induced vomiting or laxatives to counteract the calories consumed during a binge episode. The nonpurging subtype attempts to achieve the same goal of avoiding weight gain by excessively exercising or fasting. Individuals with bulimia nervosa typically experience a high rate of comorbid psychopathology. Mood disorders and personality disorders are most commonly associated with bulimia nervosa; to a lesser extent, obsessive-compulsive disorder and anxiety disorders are noted. Substance abuse, including excessive consumption of alcohol, is another problem particular to bulimia nervosa. Alcohol abuse occurs more frequently in individuals with bulimia nervosa than in people with anorexia nervosa; between 20 to 40 percent of bulimic women report a history of drug or alcohol abuse. Symptoms and outcomes Unlike individuals with anorexia nervosa, bulimic women usually maintain a normal weight (some may even be considered overweight). Some of the typical findings of purging subtype bulimia nervosa include swelling of the salivary glands, abrasions or calluses near the knuckles caused by scraping against teeth during episodes of self-induced vomiting (also known as Russell’s sign), and dental problems attributed to the erosion of enamel by stomach acid. Similar to women with anorexia nervosa, women who suffer from bulimia nervosa may experience interruptions in their menstrual cycles. Additionally, they may describe feeling “out of control” around food and attempting to control their weight by engaging in compensatory behavior (typically self-induced vomiting or laxative use) after a binge episode. Their relationship to food may have an addictive quality; they may also have a history of substance abuse or may be currently abusing other substances such as alcohol or cigarettes.
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Because of the clandestine nature of this illness, it is not unusual for women with bulimia nervosa to continue their behavior without seeking treatment. While the mortality rate for bulimia nervosa is significantly less than that for anorexia nervosa, this disorder nonetheless carries a number of serious medical complications, including cardiovascular abnormalities (tachyarrhythmias), severe electrolyte imbalances, increased dental problems, irregular menstrual cycles, esophageal and gastric rupture, gastrointestinal bleeding, and seizures. Studies suggest that the majority of individuals with bulimia recover. Outcome studies report that 50 percent of individuals achieve full recovery, 30 percent demonstrate marked improvement, while the remaining 20 percent still engage in behaviors that meet the criteria for bulimia nervosa at the follow-up point. However, longitudinal studies have shown that bulimic symptoms decrease over time. A low self-esteem emerged as a predictor of outcome in bulimia nervosa.
Current Research Because eating disorders typically occur in women and in industrialized Western cultures, it has been suggested that aspects of Western culture influence disordered eating patterns and that eating disorders could be thought of as “culture-bound syndromes.” Using Raymond Prince’s definition of a culture-bound syndrome as “a collection of signs and symptoms (excluding the notion of cause) that is restricted to a limited number of cultures primarily by reason of certain of their psychosocial features,” Pamela Keel has examined the research on the incidence of bulimia nervosa in non-Western cultures. If a disorder does not exist without any form of Western influence, it could be construed as a culture-bound illness. Keel highlights current research on bulimia nervosa that may support this assertion and reports that bulimia nervosa is associated with Western influences (e.g., with few exceptions, the low prevalence of bulimia nervosa in non-Western nations).
Treatment and Prevention Hospitalization is rarely required for bulimia nervosa unless the individual has a major medical problem or is suicidal. For those with uncomplicated bulimia nervosa, the most effective treatment that has emerged may include cognitive behavioral therapy, other interpersonal therapy, antidepressant medication, or some combination of these. Cognitive behavioral therapy focuses on the present and emphasizes the link between thoughts, feelings, and behaviors related to the eating disorder. Treatment with medication has been more successful with bulimia nervosa than with anorexia nervosa. Although various antidepressants, including tricyclics, selective serotonin reuptake inhibitors, and monoamine acid oxidase inhibitors, have been shown to be effective in reducing symptoms of bulimia, fluoxetine (also known by the trade name Prozac®) is to date the only drug approved by Food and Drug Administration for treatment of bulimia nervosa. While targeted and universal prevention efforts have improved both knowledge and attitudes, there has been little demonstrated success in changing disordered eating behavior. This has been attributed to a need to increase understanding of the risk factors that lead to eating disorders as well as continued effort to sustain the intervention’s success.
SEE ALSO: Anorexia Nervosa; Eating Disorders; Psychia-
try; Psychotherapy.
Bibliography. Anne E. Becker, et al., “Eating Disorders,”
New England Journal of Medicine (v.341, 1999); Sara F. Forman, “Eating Disorders: Epidemiology, Pathogenesis, and Clinical Features,” in B.D. Rose, ed., UpToDate, www.UpToDate.com (cited February 2007); Sara F. Forman, “Eating Disorders: Treatment and Outcome,” in B.D. Rose, ed., UpToDate, www.UpToDate.com (cited February 2007); James I. Hudson, et al., “The Prevalence and Correlates of Eating Disorders in the National Comorbidity Survey Replication,” Biological Psychiatry (v.61/3, 2007); Pamela Keel, Eating Disorders (Pearson Education, 2005). Lareina Nadine La Flair Harvard University
Burkina Faso Burkina Faso, located in west Africa, is a landlocked country surrounded by Mali, Niger, Benin, Togo, Ghana, and Côte d’Ivoire. Known for generations as Upper Volta, in 1984 it became Burkina Faso, meaning “land of the upright people.” The land is crossed
Burns
by four major rivers, le Mouhoun (the Black Volta), le Nekambé (the White Volta), le Nazinon (the Red Volta), and la Comoé. Only le Mouhoun and la Comoé flow year-round, and only 25 percent of the population have access to potable water. The population is 13.9 million and growing at 3 percent annually. The birth rate is 45.62 per 1,000 people and the death rate is 15.6 per 1,000 people. Only 18 percent of Burkinabes live in urban areas. Population density is 48 people per square kilometer. Ninety percent of the population is engaged in subsistence farming. There is no industrial base nor mineral or natural resources to exploit. The need for employment has led to the mass emigration of 3 million Burkinabes, mostly to neighboring Côte d’Ivoire. This has caused a wide demographic disparity: 56 percent of the population is under the age of 18 and well over 50 percent is female. About 45 percent of the population live on less than $1 a day. Life expectancy at birth is 47.3 years for males and 48 years for females, with healthy life expectancy of 34.9 for men and 36.3 for women. Infant mortality is 91.35 deaths per 1,000 births. Mortality for children between 1 and 5 years is 192 per 1,000. Maternal mortality is 1,000 deaths per 100,000 live births. Obstetric fistula is a serious problem among Burkinabe women. The fertility rate is 6.47 births per woman. Only 38 percent of births are monitored by a trained attendant. Child marriage is common, with one in three girls married before the age of 18 and some marrying as early as 8. Childbearing begins early and can lead to tearing of the birth canal and surrounding tissue. Unrepaired, this can lead to lifelong urinary or fecal incontinence. Women suffering this injury are often shunned by their husbands and communities and forced to live in shame. Burkina Faso has launched a “National Strategy for the Eradication of Fistula,” offering educational programs and opportunities for corrective surgery. It is also launching initiatives through its Safe Motherhood program, and is trying to limit or end the practice of child marriage. Almost 60 percent of Burkinabe children between the ages of 5 and 14 work. School attendance is low, with 53 percent of boys and 39 percent of girls enrolled in primary school. Adult literacy rates are 19 percent for men and 8 percent for women. Female genital mutilation is widely practiced, with 75 to 77 percent of females over the age of 15 having had the procedure.
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The country has a high prevalence of parasitic disease, but has recently made some important gains in prevention. In 2006, the World Health Organization (WHO) announced that Burkina Faso had become the first country in its African region to achieve universal coverage of anthelmintic (antiparasitic) drugs to combat elephantiasis (lymphatic filariasis), schistosomiasis, and soil-transmitted helminthiasis (intestinal parasites). WHO is also seeing a reduction of other endemic parasitic illnesses, including onchocerciasis (river blindness). Burkina Faso sits in the African Meningitis Belt, and outbreaks of meningitis occur regularly. Between 2004 and 2006, the country suffered repeated outbreaks of yellow fever and cholera, and in 2003, there was a polio outbreak. AIDS affects 4.2 percent of the population, with about 300,000 active cases. WHO believes that 45,500 patients are currently in need of antiretroviral medications; only 4,446 are receiving them. The main hospital in Ouagadougou is one of the most modern in Africa, but outside the capital, services are few and far between. WHO counted 789 doctors and 5,518 nurses in 2004. SEE ALSO: Filariasis/Elephantiasis; Healthcare, Africa;
Meningitis; Onchoceriasis; Parasitic Diseases.
Bibliography. Central Intelligence Agency, “Burkina
Faso,” World Factbook, www.cia.gov (cited February 2007); United Nations Children’s Fund (UNICEF), “Burkina Faso— Statistics,” www.unicef.org (cited February 2007); World Health Organization, www.who.int (cited February 2007). Heather K. Michon Independent Scholar
Burns Burns are classified according to the percentage of the total body surface area involved and are measured by size and depth. Treatment and prognosis of burn injuries are based upon these classifications. It is important to understand the anatomy and function of the skin, the largest organ of the human body, to be able to diagnose and treat burn injuries. Skin is made up of two layers: the epidermis and the dermis. The
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epidermis is made of five layers, the stratum corneum being the most superficial. This layer is continuously sloughed off and regenerated. The dermis is made up of connective tissue, blood vessels, nerves, skin appendages, hair follicles, and sebaceous (oil), apocrine (scent), and eccrine (sweat) glands. The skin serves many purposes. It protects the body from chemicals, microorganisms, ultraviolet rays, and minor trauma. Skin serves as a barrier against water loss. It allows for sensation such as touch, position, pressure, pain, and temperature. Contained within the skin are special cells that serve as an immunological defense. Vitamin D synthesis occurs in the skin in response to sun exposure. These important functions can be lost with burn injuries. Traditionally, burns were classified as first, second, third, or fourth degree. This has been replaced by a system that reflects the appropriate interventions needed to treat the burn. They are classified as superficial, superficial partial thickness, deep partial thickness, and full thickness. The percentage of total body surface area (TBSA) can be assessed using the Rule of Nines method. This method divides the body into multiples of 9 percent. The entire head and neck is 9 percent, entire chest and abdomen is 18 percent, entire arm is 9 percent, and the entire leg is 18 percent of TBSA. Another method is based upon the fact that the hand is approximately 1 percent of TBSA. Using this method, one can calculate the number of “hands” that equals the area of the burn. The Lund and Browder method is age adjusted, which allows for more accurate pediatric assessment. Accurate assessments of burn injuries are essential to direct appropriate treatment. Reexamination of burn-depth estimations is necessary in the first 24 to 72 hours. Prognosis, or patient outcome, is dependent upon burn size, depth, age, and presence of inhalation injuries. Patient comorbidities, or underlying medical problems, also contribute to prognosis. Children younger than 10 years of age and adults over 50 years of age are considered to be high-risk patients. The American Burn Association classifies burns as minor, moderate, or major and gives indications for referral to a burn unit. Minor burns include partialthickness burns of less than 15 percent TBSA in the 10- to 50-year-old age group; partial-thickness burns of less than 10 percent TBSA in children under 10 or adults over 50 years; and full-thickness burns of
less than 2 percent BSA in any person. These burns usually require only outpatient treatment. Moderate burns include partial-thickness burns of greater than 15 to 25 percent TBSA in the 10- to 50-year-old age group; partial-thickness burns of 10 to 20 percent TBSA in children under 10 or adults over 50 years; and full-thickness burns of less than 10 percent in any person. Partial-thickness burns of the hands, face, feet, perineum, or any circumferential burns of the extremities are excluded. These patients require hospitalization for burn treatment. Major burns are defined as partial-thickness burns greater than 25 percent TBSA in the 10- to 50-year-old age group; partial-thickness burns greater than 20 percent TBSA in children under 10 or adults over 50 years; full-thickness burns of greater than 10 percent TBSA in any person; burns involving the hands, face, feet, or perineum; burns crossing over major joints; circumferential burns involving an extremity; inhalation burns; electrical burns; burns with associated trauma; burns in infants or the elderly; and burns in high-risk patients. These burns require referral to a specialized burn treatment center. Quantifying burn injuries is done according to burn depth and size. Superficial burns are confined to the epidermis—sunburn is a classic example. The involved skin is red, painful, and tender to touch. It blanches with pressure. Blister formation does not occur. They usually heal within seven days without scarring. Only supportive therapy is needed, with analgesics and intravenous (IV) fluids for extensive injuries. Aloe vera or a topical antibiotic such as silver sulfadiazine (SSD) or bacitracin may be used. Superficial partial-thickness burns involve the epidermis and portions of the dermis. They are painful, red, blanch with pressure, and usually form blisters. Healing occurs within one to three weeks and depends upon the density of the skin involved. Thin, hairless skin heals more slowly than thick or hairy skin. Treatment involves antimicrobial creams to prevent infection and occlusive dressings. The burn should be gently cleaned with soap and water before dressing. Dressings should be changed daily. Scarring is unusual but pigment changes may occur with healing. Deep partial-thickness burns extend from the epidermis deep into the dermis. This causes damage to hair follicles and glands. These types of burns can be difficult to assess because they may appear more su-
Bursitis
perficial initially. Pain sensation and capillary refill are lost, but pressure sensation remains intact. Blistering almost always occurs. Healing can take from three weeks to two months. Scarring is common. Treatment involves gentle cleansing with soap and water, debridement of sloughing skin or blisters, pain management with nonsteroidal antiinflammatory drugs (NSAIDs), a topical antibiotic, and occlusive dressing. Tetanus immunization should be updated for all deep burns. Surgical debridement and skin grafting may be necessary for optimal function. Full-thickness burns involve the entire epidermis and dermis. They are usually painless due to nerve damage. The skin appearance varies from waxy and white to charred and black. The skin is dry and does not blanch with pressure. Healing will not occur spontaneously with full-thickness burns. Severe scarring with contracture results. Surgical repair and skin grafting is necessary. Inhalation burn injuries require special consideration. Smoke inhalation significantly increases mortality in the burn patient and accounts for half of all fire-related deaths. Direct thermal injury is usually limited to the upper airway; injuries below the vocal cords occur only with steam inhalation. Small particles from smoke can reach the terminal bronchioles and induce bronchospasm and edema due to an inflammatory reaction. Toxic inhalants must also be addressed. Carbon monoxide poisoning can be a fatal consequence of smoke inhalation. It can cause brain hypoxia and coma, which then predisposes the patient to aspiration and further pulmonary injury. Patients with suspected carbon monoxide poisoning should be started on 100 percent oxygen by nonrebreather mask and be evaluated for hyperbaric oxygen therapy. Hydrogen cyanide is formed when nitrogen-containing polymers are burned. Cyanide can lead to profound tissue hypoxia and necessitates specific treatment. Follow-up care involves assessing the patient for signs of infection, scarring, and contracture. Patients with infected burn injuries should be hospitalized to minimize the risk of sepsis. Scarring and contracture can lead to patient disfigurement and disability, which will require specialized care. All burn patients should be seen the day after the burn injury to assess pain control and dressing changes. Subsequent follow-up is then done weekly until wound epithelialization oc-
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curs. More frequent follow-up visits are needed if special biologic or synthetic dressings are used. After epithelialization, follow-up should occur every four to six weeks to assess scar formation and patient coping. More serious, deeper burns require referral to a surgeon for treatment and follow-up. See also: Sun Exposure; Sun Protection Factor (SPF). Bibliography. E.D. Morgan and M.F. Miser, Treatment
of Minor Thermal Burns, www.utdol.com (cited September 2006); L.R. Schwartz, “Thermal Burns,” in Emergency Medicine: A Comprehensive Study Guide, 6th ed. (cited September 2006). Christina Murray, MSVI Angela Garner, M.D. University of Missouri–Kansas City
Bursitis Bursae are fluid-filled sacs located at points of contact between bony landmarks and overriding tendons. There are at least 150 bursae symmetrically distributed throughout the human body. Additional bursae can develop in areas of increased friction. Each bursa acts as a cushion that minimizes friction and allows smooth gliding interactions between bones and tendons. The bursa is lined by a membrane that secretes synovial fluid. Synovial fluid serves to lubricate the area and facilitate motion in confined joint spaces. Without bursae, limb movement would be painful. Bursitis is inflammation of the bursa. The most frequent sites of bursitis are the shoulder, elbow, hip, and knee—specifically the subdeltoid, olecranon, ischial, trochanteric, semimembranous-gastrocnemius, and prepatellar bursae. Irritation of the bursa can be acute or chronic. Various etiologies underlying bursitis include trauma (inflammatory or hemorrhagic bursitis), infection, and arthritic conditions such as osteoarthritis, rheumatoid arthritis, systemic lupus erythematosus, gout, and pseudogout. Overuse or repetitive microtrauma is the most common cause of bursitis. Bursitis is diagnosed in patients of all ages and levels of activity. The risk of bursitis increases with age; however, traumatic bursitis is more likely in patients
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under 35 years of age. Bursitis is predominantly diagnosed in males. Individuals who participate in repetitive or vigorous activity or who suddenly increase the intensity of activity are at increased risk for bursitis. Patients with bursitis typically present with point tenderness directly over the bursa, dull ache or stiffness at the affected joint, increased pain with range of motion of overlying muscles and tendons, warmth, erythema, and swelling at the bursal site. Inflammation of the calcaneal bursa can cause swelling extending proximally to the knee. Types of Bursitis Inflammatory bursitis is often due to repetitive microtrauma. Recurring injury to the bursa triggers local vasodilatation and increased vascular permeability, ultimately causing the infiltration of extracellular fluid and proteins into the bursa. Inflammation causes synovial cells to multiply and thereby increases fluid production. In the acute setting, early inflammation causes the bursa to become distended. The additional bulk is perceived as foreign by the immune system, and this stimulates further inflammation. In the cases of chronic microtrauma, the bursal wall becomes thickened and the contents of the bursal sac are altered. Rather than synovial fluid, the bursa is filled with granular, brown, inspissated blood and calcifications. Its gritty contents create more friction when bone and tendon move against the bursa. Hemorrhagic bursitis is characterized by bleeding directly into the bursa. It is typically due to violent trauma inflicted on the overlying tissues, and most commonly occurs at the prepatellar bursa of the knee. Rapid accumulation of blood causes an acute enlargement of the bursa and accompanying pain. The increased bursal mass hinders mobility of the nearby joint. Infectious bursitis most commonly affects the olecranon and prepatellar bursae. Predisposing factors include diabetes, alcoholism, steroid therapy, uremia, trauma, skin disease, and a history of noninfectious bursitis. Patients will present with extreme tenderness, warmth, and erythema at the site, and there is often evidence of injury to the overlying skin. Infection often occurs from direct introduction of bacteria through traumatic injury or by contiguous spread of cellulitis. Bacterial infection is most commonly due to Staphylococcus aureus and Staphylococcus epidermi-
dis. Roughly 10 percent of cases have been linked to species of Streptococcus. Further support for infectious bursitis includes the presence of lymphadenitis, cellulitis, and fever. The absence of these findings, however, does not rule out infection. Acute swelling and erythema warrant aspiration of the bursa and analysis of the fluid—including cell count, Gram stain, culture, and microscopic evaluation. A bursal fluid white cell count greater than 1,000/mcL is consistent with infection. A measurement greater than 50,000/mcL suggests septic bursitis. Complete laboratory evaluation should also include a complete blood count and erythrocyte sedimentation rate. Bursitis due to crystal deposition is associated with various arthritic conditions, including rheumatoid arthritis, gout, and pseudogout. On aspiration, various types of crystals may be seen based on the underlying illness: monosodium urate (gout), calcium pyrophosphate (pseudogout), cholesterol (rheumatoid chylous bursitis), and hydroxyapatite (hydroxyapatite crystal disease). Crystal deposition and the arthritides are less common causes of bursitis. The differential diagnosis for upper extremity pain includes rotator cuff tear, adhesive capsulitis, tendonitis, shoulder dislocation, fracture, and referred pain from a neck injury. Other possible diagnoses for lower extremity pain include sciatica, lumbar disc disease, pelvic stress fracture, pelvic tumor, avascular necrosis of the femoral head, meniscal tear, thrombophlebitis, ligamentous injury or tear, Osgood-Schlatter disease, Achilles tendonitis, and Reiter syndrome. Evaluation and Treatment Bursitis is typically diagnosed based on physical examination. Patients often present with abrupt onset of swelling and localized tenderness over the bursa, pain with range of motion of adjacent muscles and tendons, and erythema. One exception to note is olecranon bursitis—this condition may not be painful at presentation. Chronic bursitis may also present with disuse atrophy and weakness. When considering bursitis, it is important to obtain a thorough medical history, including duration of symptoms, recent fever, history of repetitive movement (i.e., kneeling while cleaning floors or resting elbows on a computer desk), history of rheumatic conditions (i.e., RA, SLE, or gout), surgical history, and recreational activities.
Diagnostic testing may include aspiration of the bursa with fluid analysis, radiological studies (X-ray, magnetic resonance imaging, computerized tomography, bone scan), complete blood cell count, erythrocyte sedimentation rate, rheumatoid factor, rapid plasma reagent, antinuclear antibody, and uric acid. As stated previously, aspiration of the bursa should be done when an infectious etiology is under consideration. The bursal fluid may be tested for cell count with differential, appearance, culture, Gram stain, and presence of crystals. Fibrocartilaginous bodies (also known as “rice bodies”) in the bursa are associated with autoimmune disorders such as rheumatoid arthritis. Radiographs are not usually necessary, but they may be done in cases of acute trauma, joint instability, or significant deformity. Trauma cases may reveal a hooked acromion process, tendon calcification, or decreased acromiohumeral distance. MRI is usually reserved for cases requiring surgery. Bone scans assist clinicians in ruling out stress fracture, avascular necrosis, and osteomyelitis. Treatment of bursitis should include pain control as well as rehabilitation and prevention of future potential injury. A seven-step plan, represented by the acronym PRICEMM, has gained wide acceptance among healthcare providers. PRICEMM has been used as a framework for tailoring a patient’s rehabilitation plan. The acronym stands for protection, relative rest, ice, compression, elevation, medication, and modalities. The first step of treatment is to eliminate pressure from the affected area and to protect the joint. Movement and pressure of the inflamed area can exacerbate symptoms and impede healing. Soft foam padding, orthopedic felt, and braces can be used to protect the affected area from increased friction or pressure. A sling can be used to protect the arm and support the shoulder in some cases of upper extremity bursitis. Heel pads can be inserted into shoes to decrease friction at the calcaneal bursae. Sitting on a foam pad (referred to as a “doughnut” cushion) has also provided relief to patients with bursitis of the hip, particularly ischiogluteal bursitis. Relative rest should be prescribed to encourage patients to continue participation in exercise, but to choose activities that will not further irritate the bursa. Initially, activity should be modified to avoid things that exacerbate the pain. The overall goal should be for the patient to refrain from the triggering activity, but
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to maintain their fitness level by participating in alternative activities such as swimming or cycling. Continued physical activity accelerates the rehabilitative process. Bed rest or immobilization of the associated joint after the inflammation subsides is not appropriate and should be discouraged in cases of bursitis. Application of an ice pack will help to decrease inflammation and swelling, allowing the bursa to return to its normal shape and consistency. Ice is also an effective analgesic. Direct application of ice to the skin should be done at least twice a day for 10 minutes at a time. Compression of the affected bursa can be accomplished with an elastic bandage. While the bursa is wrapped, the extremity should be elevated above the level of the heart to decrease the amount of swelling. Elevation of the extremity for 20–30 minutes several times daily will facilitate removal of fluid from the affected area. Various modalities have aided the healing of irritated and inflamed bursae. Electrical stimulation, ultrasound, and phonophoresis have been used to decrease inflammation and reduce pain. These practices are typically done by a physical therapist. Physical therapy is often prescribed for patients experiencing weakness in an extremity or a decline in range of motion. Medications of choice for bursitis are nonsteroidal antiinflammatories (NSAIDs) or aspirin. The goal of using these medications is to alleviate pain and allow the patient to resume activity and participate in a rehabilitation program. NSAIDs are typically used for four to six weeks if symptoms have been present for fewer than three weeks at the time of diagnosis. While NSAIDs and aspirin are the preferred initial treatment, some patients will require additional medication if conservative management is not effective. Corticosteroid injections (betamethasone, triamcinolone) are the next step in treatment. Corticosteroids are powerful anti-inflammatory medications that provide rapid relief when injected into the bursa at the point of maximal tenderness. Patient education regarding the potential side effects of corticosteroid use should always be done. All patients should be informed of the possibility for subcutaneous fat atrophy, skin depigmentation, hyperglycemia, tendon rupture, and infection. Risk for these complications is decreased when the injections are spaced at least one month apart. As discussed earlier, some cases of bursitis are due to a bacterial infection of the bursal fluid. If this is the
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case, the swollen bursa needs to be drained in order to evacuate the infected fluid. Antibiotics should be prescribed to cover potential infectious agents, typically Staphylococcus species; penicillinase-resistant penicillins (i.e., dicloxicillin, nafcillin, oxacillin) or first-generation cephalosporins (i.e., cephalexin) are frequently used for treatment. The chosen medication may need to be adjusted after culture and analysis of the fluid. Surgery is another option for treatment of bursitis, but it is rarely done. The main surgical candidates are patients with chronic bursitis or infectious bursitis. In chronic cases that have not improved with traditional therapy, surgery may be done to correct an anatomical abnormality, such as a bone spur. In cases of infection, the bursa may be opened and drained (“incision and drainage” procedure) or removed entirely. See also: Elbow Injuries and Disorders; Knee Injuries
and Disorders.
Bibliography. Janus Butcher, Keith Salzman, and Wade
Lillegard, “Lower Extremity Bursitis,” American Family Physician (May 15, 1996); David Hellmann and John Stone, “Arthritis & Musculoskeletal Disorders,” in Lawrence Tierney, Maxine Papadakis, and Stephen McPhee, eds., Current Medical Diagnosis & Treatment (Lange Medical Books/ McGraw-Hill, 2006); Rita Seeger Jablonski and Elaine Ferrary, “Common Medical Problems: Musculoskeletal Injuries through Urinary Tract Disorders,” in Ellis Youngkin and Marcia Davis, eds., Women’s Health: a Primary Care Clinical Guide (Pearson Prentice Hall, 2004); Timothy Robinson and Brenda Oshea-Robinson, “Bursitis,” in Mark R. Dambro, ed., Griffith’s 5-Minute Clinical Consult (Lippincott Williams & Wilkins, 2006); Keith Salzman, Wade Lillegard, and Janus Butcher, “Upper Extremity Bursitis,” American Family Physician (November 1, 1997). Stacy Frye Michigan State University College of Human Medicine
Burundi Burundi is a landlocked country in central Africa surrounded by Rwanda, Tanzania, and the Democratic Republic of the Congo. Ethnic war broke out between
the Hutu and Tutsi in 1993 and lasted until a ceasefire in 2003; the conflict killed 200,000 Burundians and displaced hundreds of thousands more. Two years after the end of the fighting, there were 117,000 internally displaced persons and 485,000 refugees in nearby Tanzania awaiting resettlement. Ongoing inter-ethnic tension and occasional violence has hampered the work of international aid workers and restricted the flow of humanitarian aid in recent years. About the size of Maryland, the population of Burundi is 8,391,000 and growing at 3.6 percent annually. The birth rate is 41.97 per 1,000 and the death rate is 13.17 per 1,000; the migration rate is 7.13 per 1,000, as refugees make their way home. Median age is just 16.7 years. Life expectancy is 68.91 years for males and 54.75 years for females. Burundi is resource poor and has no industrial base. Only 11 percent live in urban areas. Ninety percent of Burundians rely on subsistence agriculture to get by. Gross national income is U.S. $100 a year. Less than 50 percent of the population has clean drinking water and only 36 percent have sanitary waste disposal. Along with the climate, poverty, and general overcrowding, this creates a breeding ground for epidemic levels of acute respiratory disease and diarrhea. Malaria cases account for 40 percent of health-center patients. Cholera is endemic, as is meningitis. AIDS has struck Burundi hard, with an adult prevalence rate of 3.3 percent. About 150,000 Burundians are estimated to be infected, including 79,000 women and 20,000 children. There have been an estimated 13,000 AIDS-related deaths. Despite a strategic plan by the government, lack of funding and infrastructure has hampered treatment and prevention efforts. Only 14 percent of patients are receiving antiretroviral treatment. Just 2.4 percent of pregnant woman are being treated to prevent mother-to-child transmission. A 2006 survey found just 3.6 percent of men and women could identify ways to prevent HIV infection. AIDS is still highly stigmatized in Burundi, making life difficult for patients and for the estimated 120,000 children orphaned by the virus. Women’s health has suffered greatly, both during and after the war. Not only do they suffer from the threat of disease, poverty, and malnutrition, they also face widespread sexual abuse and violence. In one recent survey, 42 percent of women said they had been the victims of domestic violence. In another study, 19
percent of women had suffered sexual violence. Rape is stigmatized, and few cases are ever brought to trial. Only 16 percent of Burundian women use contraceptives. The fertility rate is 6.48 children per woman. About 78 percent receive some prenatal care, but only 25 percent have a trained attendant during childbirth. The maternal mortality rate is among the world’s highest, with 1,000 deaths per 100,000 live births. Burundian women thus have a 1 in 12 lifetime risk of dying in childbirth. Children’s health has also suffered. Mortality estimates show that 114 children out of every 1,000 die before their first birthday, with 190 children of every 1,000 dying before the age of 5. Children are much more likely to die from diarrhea and respiratory infections, and 50 percent of all malaria deaths in Burundian hospitals are under age 5. Children also face violence, displacement, death, and injury from landmines, trafficking into prostitution, or militias. Little is known about the current status of the medical system. Many facilities were destroyed during the fighting. The government spends U.S. $1 per capita on healthcare. While 80 percent of the population live with five kilometers of a medical facility,
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there is a huge shortage of staff, equipment, and critical drugs. Up to 90 percent of patients have to go into debt to obtain care. See also: Healthcare, Africa; Rwanda. Bibliography. Central Intelligence Agency, “Burundi,
World Factbook, www.cia.gov (cited June 2007); Joint United Nations Programme on HIV/AIDS, “Burundi,” www.unaids.org (cited June 2007); Researchafrica.rti.org, “Sub-Saharan Africa—Burundi,” researchafrica.rti.org (cited June 2007); United Nations Children’s Fund (UNICEF), “Burundi—Statistics,” www.unicef.org (cited June 2007); World Health Organization, “Health Action in Crisis: Burundi, December 2005 Country Report,” www.who .int (cited June 2007); World Health Organization, “WHO Global InfoBase,” www.who.int (cited June 2007); World Health Organization, “Guide to Statistical Information at WHO,” www.who.int (cited June 2007); World Organization Against Torture, “Violence against Women in Burundi,” www.omct.org (cited June 2007). Heather K. Michon Independent Scholar
C Caffeine Caffeine, or trimethylxanthine, is a substance that appears naturally in plants such as coffee, tea, cacao, guarane, and kola nuts. In some cases, it acts as a pesticide by killing insects feeding on the plant. Caffeine acts as a stimulant to the central nervous system and has become the most commonly taken psychoactive drug in the world, with large international industries promoting the drinking of coffee and tea as a sophisticated lifestyle choice, in addition to its stimulant effects. Carbonated cola drinks also make use of caffeine to different extents and, in recent years, there have been considerable marketing efforts to promote hypercaffeinated soft drinks as a means of staving off fatigue and increasing personal productivity. These drinks are subject to abuse and, taken in large quantities, can lead to medical problems such as heart disease or even failure. A typical cup of coffee might contain 100 milligrams of caffeine, because caffeine represents some 0.7 to 1.5 percent of coffee by total weight. The caffeine content of a cup of tea may be around 40 milligrams, although tea varies a great deal in this regard, while soft drinks vary between 10 to 80 milligrams of caffeine per serving. These drinks are part of an enormous global trade that links impoverished coffee growers, powerful and wealthy inter-
mediaries and coffee companies, and the consumers of the world’s cities and suburbs. Coffee growing has become central to the struggle for justice in the fairtrade movement. Regular users of caffeine, who include the great majority of adults in most Western countries and in those countries where coffee is typically grown, report increased liveliness and thought stimulation after imbibing caffeine in the preferred format. In some cases, it is believed that physical performance can also be increased for a relatively short time after taking caffeine. This effect intensifies with the dose of caffeine taken, which varies in efficacy from person to person and with regularity of usage. Negative impacts include sleeplessness, heart problems, and nervous irritability. Withdrawal from caffeine use can lead to headaches and nausea, caused by excess flow of blood to the head. The period of withdrawal symptoms ranges up to five days, depending on the length and intensity of the usage. This means that caffeine should be considered an addictive substance. However, the use of caffeine is not regulated as a general principle anywhere in the world. Nevertheless, after the sudden deaths of several young people who were believed to have drunk a highly caffeinated soft drink and possibly combined it with vodka, regulation was suggested in some European countries, despite lack of definitive proof.
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Calabresi, Paul SEE ALSO: Anxiety Disorders; Drug Abuse; Heart Diseases
(General); Sleep Disorders.
BIBLIOGRAPHY. “Red Bull in Suspected Link to Deaths,”
BBC News Online, news.bbc.co.uk (cited April 2007); A. Nehlig, J.L. Daval, and G. Debry, “Caffeine and the Central Nervous System: Mechanisms of Action, Biochemical, Metabolic and Psychostimulant Effects,” Brain Research (v.17/2, 1992); Antony Wild, Black Gold: A Dark History of Coffee (HarperPerennial, 2005). John Walsh Shinawatra University An average cup of coffee contains about 100 milligrams of caffeine and it represents some 0.7 to 1.5 percent of coffee by total weight.
Calabresi, Paul (1930–2003) Other results of overuse of caffeine include sleep disorders and anxiety, with more extreme cases leading to heart palpitations. Because the drinking of caffeine stimulates the production of gastric acid, excessive drinking can lead to the formation of peptic ulcers and the problems associated with them. Extreme use of caffeine can lead some individuals into a state of extreme excitability and can be related to an inability to think or communicate coherently. Repeated long-term use can also produce similar symptoms in some people; office workers are likely to be particularly susceptible to such problems, owing to the sedentary nature of working life and the easy availability of caffeinated products. In recent years, efforts have been made to promote and market decaffeinated products and to make people aware of negative effects of the substance. Caffeine is also used to combat depression of respiration, such as might result from overdoses of barbiturates or morphine. Other breathing problems might also be treated by caffeine preparations, which should be prescribed by medical practitioners. Some research has suggested that the use of caffeine can prevent the outbreak of Parkinson’s disease among men, inhibit certain types of heart disease, and can retard baldness. Clearly, these conditions would represent lucrative opportunities for pharmaceutical companies capable of manufacturing safe and effective remedies. However, it is not currently known quite how caffeine works in these cases. Further research is indicated.
Paul Calabresi was an Italian-born American oncologist whose research led to the development of pharmacological treatments for cancer. Calabresi was born to Massimo Calabresi and Bianca Maria Finzi-Contini Calabresi in Milan, Italy, on April 5, 1930. His family opposed the Fascist dictatorship of Benito Mussolini, and when Paul was nine, they moved to New Haven, Connecticut, where Paul attended Hopkins School. He then enrolled at Yale College, from which he graduated in 1951. After earning his M.D. from the Yale School of Medicine in 1955, Calabresi served as an intern and resident on the Harvard Medical Services of the Boston City Hospital. He then became a member of the Yale faculty, teaching there until 1968. While at Yale, Calabresi chaired the Clinical Pharmacology Advisory Committee for the Yale Cancer Center. After he left Yale, he joined Brown University as professor of medical science and as physician-in-chief of Roger Williams General Hospital. At Brown, he founded the University Cancer Center, which he also directed, and he was appointed chair of the department of medicine in 1974. In 1991, he transferred to Rhode Island Hospital but continued to teach at Brown. Throughout his career, Calabresi was active in researching the potential of anticancer agents and developing pharmacological treatments for cancer. His studies led to therapies for diseases like Hodgkin’s lymphoma, breast cancer, and prostate cancer. Because of his international reputation as an oncologist,
Calcium
Calabresi was often involved in the National Cancer Program. Different political administrations relied on him as an adviser on oncological issues. President George H.W. Bush appointed him a member of the National Cancer Advisory Board in 1991. Four years later, President Bill Clinton made Calabresi one of the three members of the President’s Cancer Panel. In 1998, he helped found the National Dialogue on Cancer (NDC), which is cochaired by President George H.W. Bush and Barbara Bush. Calabresi served on the steering committee of the NDC until his death. In 1999, Senator Dianne Feinstein appointed Calabresi to the National Cancer Legislation Advisory Committee. Calabresi was also a member of prestigious committees including the boards of overseers at the E. Bronson Ingram Cancer Center at Vanderbilt University and Tufts University School of Medicine, and the National Board of Trustees for the Leukemia and Lymphoma Society. He was an honorary life member of the board of directors of the American Cancer Society. SEE ALSO: Cancer (General); Oncologist; Oncology. BIBLIOGRAPHY. Rhode Island Cancer Council, “Paul Ca-
labresi, M.D., M.A.C.P.,” www.ricancercouncil.org (cited January 2007); Yale University Office of Public Affairs, “World-Renowned Oncologist Dr. Paul Calabresi Passes Away,” Yale Bulletin and Calendar, www.yale.edu/opa/v32. n10 (cited January 2007). Luca Prono Independent Scholar
Calcium Calcium is an element found in the periodic table and has an atomic number of 20. It is also the most abundant mineral found in the human body; 99 percent of total body calcium is stored in the bones and teeth. Calcium is one of the most essential minerals—it is needed not only for maintaining bone health, but also for proper muscle and nerve function. Calcium is necessary for blood vessel contraction and growth, the release of hormones and enzymes, and the maintenance of the body’s basic structure.
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Bones are constantly reconstructed and remodeled throughout an individual’s lifetime. After bone has been broken down, calcium is then restored back into it in order to increase the strength of the bones. This cycle also occurs in an individual’s growing years, when bone formation occurs more frequently than bone breakdown. As an individual ages, the balance between these two phases of bone growth changes. In aging adults, especially postmenopausal women, breakdown exceeds formation, leading to bone loss. When the body’s blood levels of calcium decrease, calcium that was stored in bones is used to replenish the body’s calcium. Insufficient calcium intake, a decrease in calcium uptake, or an increased loss of calcium in urine can decrease total calcium in the body, leading to osteoporosis (also known as poor bones). Osteoporosis, which strikes about 10 million Americans, is the weakening of bones caused by an imbalance of bone destruction and building. In order to provide a strong foundation for bone, calcium intake needs to be increased and maximum bone stores must be made before age 30. Hypocalcemia is a medical condition that usually occurs not from a decrease in uptake of calcium but as a side effect of other diseases, such as kidney failure or stomach problems. Both of these organ systems are crucial to calcium absorption in the body. Diuretics, medications that cause an individual to increase urinary excretion and are taken to decrease blood pressure, can also result in a decrease in calcium. Severe cases of hypocalcemia can result in irregular heart rates and death. The Institute of Medicine and the National Academy of Sciences are both responsible for setting a standard recommended level of calcium, also known as the Dietary Reference Intake. For calcium, the recommended intake is listed as an Adequate Intake (AI), which is a suggested average intake level based on observed or experimentally determined levels. Research has shown that adults are not meeting these calcium requirements. There are many calcium-rich foods suggested to prevent calcium deficiency, the top three being milk, yogurt, and cheese. According to the U.S. Department of Agriculture’s Food Guide Pyramid, individuals age 2 and above need two to three servings of dairy products per day. A diet rich in protein, especially from animal sources, can cause calcium loss in the body. Sulfur,
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which is found in meat, increases calcium excretion, and a diet rich in meat causes bone demineralization. Calcium is also responsible for muscle contraction and enzyme function. Calcium levels in the blood are regulated by the parathyroid hormone and calcitonin, a hormone that lowers the calcium in blood by slowing bone breakdown. When blood calcium levels fall, more parathyroid hormone is made by the parathyroid glands; less hormone is made if blood calcium levels are high. The hormone is what stimulates the digestive tract to absorb more calcium and causes kidneys to activate vitamin D, which causes even more absorption of calcium. When an individual has too much calcium in his or her blood, they have a condition known as hypercalcemia. This is most commonly caused by an increase in the amount of parathyroid hormone, a condition known as hyperparathyroidism. It can also be caused by an increase in the intake of calcium or vitamin D and by cancers of the kidneys, lungs, and ovaries. Calcium is released when cancer metastasizes to bone and destroys bone cells. Any disorder that causes a breakdown in bone can also be responsible for hypercalcemia. Those who are immobilized, such a paraplegics, quadriplegics, or people who require bed rest, may develop hypercalcemia because calcium in the bone is released into the blood when bones are inactive for long periods of time. Patients who have hypercalcemia do not present with symptoms unless the condition becomes very severe, in which case they may suffer brain dysfunction, delirium, and confusion. Hypercalcemia is usually treated with drugs that slow the release of calcium, including calcitonin, gallium nitrate, and plicamycin. A recent finding also relates calcium to the control of weight gain in middle-aged women. Women in their 50s gained four pounds less when they took 500 milligram supplements of calcium as opposed to women who did not take any. Studies have shown that low intakes of calcium boosted the levels of calcium found within cells and turned on the genes involved in fat formation. See also: Bone Diseases; Bone Health; Osteoporosis. BIBLIOGRAPHY. A. Gonzalez, et al., “Calcium Intake and
10-Year Weight Change in Middle-Aged Adults,” Journal of
the American Dietetic Association (v.106/7, July 2006); Harvard Public School of Health, “Calcium and Milk,” www. hsph.harvard.edu/nutritionsource (cited October 2006); Merck Manual, “Calcium: Minerals and Electrolytes,” www. merck.com (cited October 2006). Angela Garner, M.D. University of Missouri–Kansas City
Cambodia This country located in mainland southeast Asia has a relatively undeveloped medical care system. Cambodia was a French protectorate from 1863 until 1953, being a part of French Indochina. It gained its independence in December 1953, as the Kingdom of Cambodia, and was the scene of a bitter civil war from 1970 until 1975, and again from 1978 until 1991 when it was occupied by a pro-Vietnamese government. During the periods of war, its health system was devastated, although there is now a relatively good service for wealthier people. Cambodia with a population of 13,363,000 (2004), has 30 doctors and 74 nurses per 100,000 persons. In medieval times, the Kingdom of Angkor, covering much of what is now Cambodia, relied mainly on faith healers, and there is also evidence of Chinese medical practices and herbal cures. The first European “doctor” to visit Cambodia was Charles Lister, a British merchant who moved to the country in 1701, and pretended to have a knowledge of medicine. He managed to cure the then king, Chettha IV, and was appointed the court physician, a position which was subsequently filled by his descendants who were still in the same position in 1822. With the arrival of the French in 1863, there was a medical service established in the country primarily for the treatment of Europeans and also wealthier Cambodians. Most of it was centered on Phnom Penh, the country’s capital, although there were small clinics at Kompong Cham and other regional centers. The Preah Keth Mealea Hospital was established in 1891, and until 1955 it was the only hospital of any size in the country. After independence, the government of Prince Norodom Sihanouk massively enlarged the provision of healthcare to all towns and also many vil-
Cameroon
lages, and also embarked on a program of eliminating areas where mosquitoes could breed, thereby significantly reducing the incidence of malaria. At this time, a number of Cambodian doctors became important administrators with Dr. Sonn Mam (1888–1966) being minister of health in the late 1940s and early 1950s. In 1940, he had founded the Psychiatric Hospital at Takhmau, and when he retired from politics, he continued to run the hospital, as well as becoming a professor at the newly established Royal School of Medicine. The other important hospital in Phnom Penh during the 1950s and 1960s was the Calmette Hospital, but again it generally treated members of the foreign community or urban elite. Many of the senior Cambodian government officials sought treatment overseas, with longtime defense minister, later prime minister, Lon Nol seeking treatment in France after a car crash in 1967, and, while he was president, in Hawaii after a stroke in 1971. His adversary Prince Norodom Sihanouk also sought medical treatment from rest cures in Grasse in the south of France. He later sought treatment in China for cancer. The civil war which raged from 1970 until 1975 saw the medical services, which had been relatively good under Sihanouk, destroyed or drained of resources. Doctors from Médicins Sans Frontières worked in the country, as did an increasing number of Cambodians who had been trained in medicine. One of these was Haing S. Ngor who was later to settle in the United States, and star in the Hollywood film The Killing Fields (1984) in which one of the most dramatic scenes was at the Preah Keth Mealea Hospital on April 17, 1975, when the Communists, the Khmer Rouge, won the civil war and evacuated all the cities and towns in the country. During the three-and-a-half years of Khmer Rouge rule, the health services were effectively destroyed with villagers surviving on herbal cures, and work undertaken in the few remaining village clinics, although these were mainly used by party officials. In December 1978, the country was invaded by Vietnam, and the war that followed resulted in the laying of millions of landmines, with the result that one of the major problems facing the Cambodian medical system through the 1980s to the present day are the many unexploded mines in the countryside, causing terrible injuries and loss of limbs. Following the Paris Peace Agreement of 1991, the health care system has been improved, and placed un-
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der the direction of the newly established National Institute of Public Health. However, the life expectancy for the country remains low. In 1991, it was 48 years for males and 51 years for females, rising to 61 today. In many parts of the country, bad sanitation and problems over access to fresh water, has seen significant numbers of people suffering from waterborne diseases, and also from malaria as well as hepatitis A and hepatitis B. In addition, there are many cases of malaria, rabies, and tuberculosis. Many travelers to the country have also suffered from heat exhaustion and heat stroke, and there has been a rising level of AIDS cases. Although pharmacies throughout the country are now well stocked, and there are increasing numbers of hospitals, these are largely located in the capital and major cities and towns, with the healthcare services in the countryside remaining rudimentary. See also: Hepatitis B; Malaria. BIBLIOGRAPHY. Justin Corfield and Laura Summers, His-
torical Dictionary of Cambodia (Scarecrow Press, 2003); Photo-Souvenirs du Cambodge—Sangkum Reastr Niyum: Sante Publique 1955–1969 (Government of Cambodia, c.1994). Justin Corfield Geelong Grammar School, Australia
Cameroon Cameroon is a republic in western Africa with a coastline on the Bight of Bonny on the Gulf of Guinea. Sometimes referred to as “Africa in miniature” for containing all of the major geographical attributes of the continent—coastline, savannah, mountain, rainforest, and desert—Cameroon also has many of the social challenges that face Africans. Two former French and British colonies merged to form the country in 1961 and it has enjoyed relative peace and stability since then. Although Cameroon has a welldeveloped economic sector based on timber and agricultural exports and modest petroleum reserves, many Cameroonians live in poverty, and the government is controlled by a single party. Observers say human rights abuses are common, and there is growing
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unrest among the people, particularly in Anglophone areas of the former British Cameroon. The population is 18,100,000 and is growing at 2.24 percent annually. The birth rate is 35.07 per 1,000, with a death rate of 12.66 per 1,000. Median age is 18.9 years. Life expectancy is 52.15 years for males and 53.59 years for females. Fifty-three percent of the population live in urban areas. Gross national income is $1,010. Fortyeight percent of Cameroonians live in poverty, with 17 percent living on less than $1 day. Malaria is endemic throughout the country, and is the leading cause of both illness and death in Cameroon. It is the cause of 50 percent of all medical consultations and 30 percent of all hospitalizations. In two-thirds of the country, malaria is resistant to standard drug treatment. Yellow fever is common in some regions. Potable water and sanitary waste facilities are available to less than half of rural Cameroonians. There are frequent outbreaks of cholera, meningococcal meningitis, and schistosomiasis. In 2007, the H5N1 avian flu was detected in birds within Cameroon, but there have been no reported human transmissions to date. The adult prevalence rate for HIV/AIDS is 5.4 percent, with an estimated 510,000 Cameroonians infected with the virus. There have been 46,000 AIDS-related deaths. Women between the ages of 15 and 24 have borne the brunt of the virus, with 290,000 infected so far. Twenty-two percent of patients are receiving antiretroviral drugs. Only 4.2 percent of pregnant women are treated to cut the risk of mother-to-child transmission of the virus. Education does seem to be making some inroads. Cameroon is an important site for AIDS research: All of the strains of HIV/AIDS are present in the population. The fertility rate for Cameroonian women is 4.49 children; only 23 percent have access to contraceptives. Over 60 percent of rural women marry in adolescence. Legal abortions are restricted, forcing women to use illegal means. In a survey, 21 percent of respondents said they had had an abortion at some point in their lives; 40 percent had undergone more than one. Most went to doctors or nurses for the procedure, but safe practices were not generally used. One in four women had complications. Childbirth is also risky, with 670 deaths per 100,000. Infant and child mortality is 85 deaths per 1,000 for children younger than 1, and 149 deaths per 1,000 for those aged 1–5 years.
Cameroon spends $14 per capita on healthcare. There are a wide variety of hospitals and clinics, including public, private, and mission institutions. Medical staff is minimal, with 7.4 physicians and 36.7 nurses per 100,000. See also: AIDS; Healthcare, Africa; Malaria. BIBLIOGRAPHY. Central Intelligence Agency, “Cameroon,”
World Factbook, www.cia.gov (cited June 2007); Guttmacher Institute, “Although Abortion Is Highly Restricted in Cameroon, It Is Not Uncommon among Young Urban Women,” www.guttmacher.org (cited June 2007); Joint United Nations Programme on HIV/AIDS (UNAIDS), “Cameroon,” www.unaids.org (cited June 2007); Researchafrica.rti.org, “Sub-Saharan Africa—Cameroon,” researchafrica.rti.org (cited June 2007); United Nations Children’s Fund (UNICEF), “Cameroon—Statistics,” www.unicef.org (cited June 2007); World Health Organization, “Guide to Statistical Information at WHO,” www.who.int (cited June 2007); World Health Organization, “WHO Global InfoBase,” www.who. int/infobase (cited June 2007). Heather K. Michon Independent Scholar
Canada With a per capita income of $33,900, Canada is the 16th-richest country in the world, with a high standard of living and easy access to healthcare. The United Nations Development Programme Human Development Reports rank Canada sixth in the world in overall quality-of-life issues. Commitment to healthcare is integral to the Canadian philosophy, and the government allots 3 percent of the total budget for health expenditures. Almost 10 percent (9.9 percent) of the Gross Domestic Product (GDP) is earmarked for health spending, and $2,989 (international dollars) per capita are used to provide healthcare. Government funding accounts for 69.9 percent of total health expenditures, with 2.1 percent assigned to funding social security. The private sector provides 30.1 percent of healthcare expenditures, and 49.60 of those costs are outof-pocket expenses. There are 2.14 physicians, 9.95
nurses, 0.59 dentists, and 0.67 pharmacists per 1,000 population in Canada. Following the lead of Saskatchewan, other provinces became involved in providing healthcare at the end of World War II. In 1966, the Federal Medicare Program was established to provide medical benefits for the elderly. Canadians are adamant about the government’s responsibility to provide healthcare through the National Health Service, which is funded through a combination of federal and provincial taxes and user fees. By law, every Canadian must be covered under the plan, and coverage must be uniform across the nation. The plan is both portable and comprehensive, guaranteeing quality healthcare in all provinces and covering all medically necessary hospital stays and doctors’ fees. Canada’s health plan is implemented on a nonprofit basis in cooperation with the private sector. Canada has the 12th-highest life expectancy in the world. The approximately 33,098,932 people of Canada can expect to live to 80.22 years, with women outliving men by an average of six years. Literacy is predictably high, and only 1 percent of the population over the age of 15 are unable to read and write. One hundred percent of Canadian children are enrolled in primary and secondary school. Despite the high standard of living, some Canadians do suffer economically; current unemployment is reported at 6.8 percent. While Canada does not have an official poverty line, wages for 15.9 percent of the population fall below the low income cut-off (LICO) line. The segments of the population most likely to be poor are aboriginals (27 percent) and single mothers with dependent children (35.1 percent). As a result of unequal distribution of income, Canada ranks 33.1 on the Gini index of inequality, with the richest 10 percent claiming 23.8 percent of resources while the poorest 10 percent share only 2.8 percent. One hundred percent of urban Canadians have access to safe drinking water and improved sanitation, and only 1 percent of rural residents lack such access. Three-fourths of Canadian women use some method of birth control, and the fertility rate is predictably low at 1.61 children per female. Only 2 percent of births occur outside the presence of trained personnel. The adjusted maternal mortality rate is predictably low at six deaths per 100,000 live births. Domestic violence is a major problem in Canada, particularly among military families, and threatens the health of both women and
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Canadians are adamant about the government’s responsibility to provide healthcare through the National Health Service.
children. However, new laws, greater public awareness and government responsibility, and an increase in the number of available shelters for abused women and their children has resulted in a decline in the number of domestic violence cases reported in recent years. Particular attention is being paid to aboriginal women because of historical patterns of domestic violence among this group both on and off reservations. At 4.69 deaths per 1,000 live births, Canada has the 23rd lowest infant mortality rate in the world. Between 1990 and 2004, infant mortality declined from seven to five deaths per 1,000 live births, and under-5 mortality fell from eight to six deaths per 1,000 live births. Six percent of all infants are underweight at birth, but most Canadian children are remarkably healthy. Diphtheria, pertussis, and tetanus (DPT1) vaccines are received by 97 percent of all children,
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measles by 95 percent, DPT3 by 91 percent, polio by 88 percent, and Haemophilus influenzae type B by 83 percent. Efforts to improve the lives of children led to the passage of the Canada Child Tax Benefit in 1998, which combined the former child benefit with a new supplement designed to subsidize low-income families. Several provinces also have separate child benefit packages. These programs provide supplementary health benefits, childcare, at-risk services for children, and job training for mothers. With a 0.3 percent adult prevalence rate, the HIV/ AIDS virus has created a major health problem for Canada. Around 56,000 people are living with this disease, which has already claimed the lives of about 1,500 people. Most communicable diseases have been eradicated, but influenza epidemics occur often. A suspected outbreak of severe acute respiratory syndrome (SARS) in British Columbia in August 2003 was found to be without basis. However, both leptospirosis and E. coli appeared in 2000, and the West Nile virus surfaced in the fall of 2002. Diabetes is a major health threat in Canada, affecting more than 2 million Canadians. In ranked order, the leading causes of death are diseases of the circulatory system, cancer, external causes, communicable diseases, and perinatal conditions. Aboriginal health is of grave concern in Canada because the incidence of chronic disease among aboriginals is three times that of the general population and the suicide rate is from two to seven times higher. More than 600 government programs are directed at meeting the needs of this population. Articulated goals include educating pregnant women about gestational diabetes, meeting the needs of youth, training in early childhood development, making the population aware of mental health issues, and preventing and treating cancer and alcohol and drug abuse. See Also: Healthcare, U.S. and Canada; Native American
Health.
BIBLIOGRAPHY. Central Intelligence Agency, “Canada,”
World Factbook, www.cia.gov (cited December 2006); Commission on the Status of Women, “Canada,” www. un.org/womenwatch (cited December 2006); Alvin Finkel, Social Policy and Practice in Canada: A History (Wilfrid Laurier University Press, 2004); Martin A. Levin and Martin Shapiro, eds., Transatlantic Policymaking in an
Age of Austerity: Diversity and Drift (Georgetown University Press, 2004); Pan American Health Organization, “Canada,” www.paho.org (cited December 2006); United Nations Children’s Fund (UNICEF), “Canada,” www. unicef.org (cited December 2006); Anne Westhues, ed., Canadian Social Policy: Issues and Perspectives (Wilfrid Laurier University Press, 2003); World Bank, “Canada Data Profile,” devdata.worldbank.org (cited December 2006); World Health Organization, “Canada,” www.who. int (cited December 2006); Dan Zuber, Differences that Matter: Social Policy and the Working Poor in the United States and Canada (ILR Press, 2006). Elizabeth R. Purdy, Ph.D. Independent Scholar
Cancer (General) The term cancer is used to describe a number of related diseases in which abnormal cells grow out of control in parts of the body and spread. It has been an affliction for thousands of years; evidence of cancerous growths and tumors has been found in fossilized human remains uncovered by archaeologists and anthropologists, and also in ancient Egyptian mummies. There is a reference to cancer on a Babylonian cuneiform from about 2000 b.c.e. Atossa, the wife of Darius the Great, the King of Achaemenian Persia, was treated for breast cancer by the captive Greek physician Democedes. It was the ancient Greek physician Hippocrates who used the term carcinoma to describe these tumors. Their ability to cling to parts of the body later gained them the name cancer, which is the Latin word for crab. For this reason, the crab is often used around the world as a sign for cancer and cancer research, and by some cancer charities. Cancer is so common that it has been estimated that half of all men and a third of all women in the United States will develop cancer at some stage in their lifetime. It should be added that many people die with cancer, though it is not the cause of death. In other countries, the rates of cancer deaths vary considerably, although they are increasing in most countries for two reasons. The main factor is increased life expectancy, as cancer develops more often in older people. Until the 19th century, many people were dy-
ing long before the age at which cancer would develop or become fatal. As healthcare around the world has improved since the late 19th century, life expectancy has increased considerably, and this, in turn, has led cancer rates to rise dramatically, even with much improved cancer treatment programs. In 1993, cancer accounted for 12 percent of all deaths—equivalent to the loss of some six million people. By 1998, cancer deaths had risen to 7.2 million, or 13 percent of all deaths in that year. World Health Organization (WHO) figures for 1998 show 81 million people living with cancer. Statistics on cancers in different countries are usually collected by tumor registries (often known as cancer registries). In some ways, the higher rate of death from cancer can almost be said to be a sign of higher life expectancy and living standards. In Singapore, cancer is now the single largest cause of death, accounting for 26 percent of deaths in 2003. In the United States, cancer is the second largest cause of death, after heart disease. Until recently, the percentage of people dying from cancer in central African countries, which generally had underfunded hospitals, was much lower because of the early deaths of many people long before the age at which they might develop cancers. However, rates have been rising with the increase in cancers that affect people suffering from diseases such as human immunodeficiency virus (HIV), and with better record keeping in these countries. The most common cancers are skin cancer, lung cancer, colon cancer, and cancer of the rectum, with women also susceptible to cervical cancer and breast cancer, and men susceptible to prostate cancer. Childhood cancers include leukemia, lymphoma, brain cancer, and osteosarcoma. Historically, some people suffering from cancer were said to have had tumors, or malignant tumors, with the disease occasionally described as a malignancy. The study of cancer is known as oncology, with cancer surgeons and cancer researchers known as oncologists. Healthy human bodies contain up to 10 trillion cells that grow, divide, and die in a relatively orderly fashion. However, cancer cells occur when a cell multiplies inappropriately. This results in the division of large numbers of these cancer cells, and this causes cancer. The causes of cancer come from a large range of sources, known as risk factors, some of which are genetic, being inherited from parents and grandpar-
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ents. Others are as a result of the patient’s lifestyle. The best-known risk factor is tobacco, the use of which can cause cancer. Smoking tobacco through cigarettes, cigarillos, or use of pipe tobacco causes lung cancer. Smoking also often leads to many other internal problems that get worse with increased use of tobacco. Smokeless tobacco, such as chewing tobacco, especially bought commercially with nicotine and other addictive agents added, can also result in oral cancer, as well as gum disease. Similar problems result from the chewing of betel nut, which is practiced in southeast Asia and parts of the Indian subcontinent. The more people use tobacco, whether through cigarettes or smokeless tobacco, the greater the chances of dying from lung cancer. This can be influenced by the age at which a person starts smoking, as well as the number of cigarettes that they smoke on a daily basis, and the tar level of the cigarettes. The result is that 30 percent of all cancer deaths in the United States are tobacco related, with lung cancer worldwide accounting for 17 percent of all deaths. Although the link between smoking and lung cancer is now widely known throughout the world, it was not conclusively proven until the British scientist and medical researcher Richard Doll wrote about his research in the British Medical Journal in 1950. cancer and lifestyle In many developed countries, diets, particularly those that contain high amounts of saturated fats (from animals) and red meat, have also led to a large number of cancers. The inadequate consumption of fruits and vegetables also contributes to cancer, but this may be because nutrients from fruits and vegetables help block the cancer-causing effects of other parts of the diet. The excessive consumption of alcohol can cause liver cancer, and some studies have shown that even some moderate levels of drinking alcohol can cause breast cancer in women, and in both sexes there is an increased prevalence of colon and rectal cancer. After many studies, it has been proven that moderate consumption of coffee or use of artificial sweeteners does not cause a higher prevalence of cancer. There have been many findings of workplace cancer since the early work of Sir Percivall Pott. Prior to Pott, a British surgeon, John Hunter, had been able to show that there were a range of cancers and that the most likely places to be affected were the breast,
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uterus, lips, external parts of the nose, gastric pylorus, and pancreas; he made no mention of lung cancer, colon cancer, or rectal cancer. In 1775, Pott, working in London, wrote about his discovery of the link between scrotal cancer in chimney sweeps with their regular exposure to soot, establishing the basis for occupational cancer. Pott’s pioneering work was important in many later studies. Indeed, the American environmental writer Rachel Carson recognized the importance of this early work by Pott, as did the British scientist and medical researcher Richard Doll. Carson used the idea in her book Silent Spring (1962), in which she wrote about the link between environmental pollution and the effects of the use of pesticides on animals, especially birds. This led to the United States banning DDT in 1972. In some workplaces and homes the use of such chemicals as asbestos and benzene has resulted in some people developing the prevalence for much higher rates of cancer. The use of defoliants such as Agent Orange in the Vietnam War has also been linked to large numbers of cases of cancer by U.S. and Australian service personnel, as well as by many people in Vietnam. Much stricter regulation of potential carcinogens has reduced the number of people suffering in developed countries, although with increasing life expectancy, lower levels of exposure over a much longer time has also increased cancer prevalence among some people. Radiation can also cause cancer. Most cancer deaths from radiation are from natural sources; for instance, skin cancer is connected with the sun’s ultraviolet rays. Overexposure to the sun and sunburn, especially in children, can lead to melanomas. This has spurred anticancer campaigns to encourage people to keep out of the bright sun and to discourage sunbathing, especially in countries with high rates of skin cancer, such as Australia. There have also been many cases of people contracting cancers from exposure to nuclear materials. Some of those who survived the atom bombs dropped on Hiroshima and Nagasaki in 1945 died from cancers. Similarly, many people in Russia, Belarus, and Ukraine, as well as some neighboring countries, have also died of cancer because of the Chernobyl nuclear accident on April 26, 1985. Although the Chernobyl nuclear power plant was located in the Ukraine, in what was then the Soviet Union, the highest rate of thyroid cancer in the region was
found in Belarus to the north, as the radiation was carried by the wind across the country. There have also been many press reports about what became known as Gulf War syndrome. Many pointed to high cancer rates in people who were exposed to radiation, especially depleted uranium; a number of studies have been undertaken, but they have produced contradictory or inconclusive findings. cancer treatments The reason why cancers have been very difficult to treat is because once a cancer cell has formed, it often moves, unlike a normal cell. This process, called metastasis, means that surgery often cannot remove all the cancerous cells. If the cancer is detected early, it may be possible to excise the cancerous area—a process known in ancient and medieval times. This has always been possible if the cancer occurs in areas that can be excised, such as the breast or a limb. Nowadays, some 60 percent of cancers in the United States are treated with surgery, although this is sometimes not the sole method of treatment. For cancer in inner organs, surgery has been made possible by developments such as key-hole surgery and the use of the flexible fiberoptic endoscope, developed by the U.S. oncologist Basil I. Hirschowitz, which has made it easier to spot the location of cancers. However, if the cancer is not detected early enough, surgery becomes more difficult, and if the cancer is well developed and has spread, surgery is ineffective. Treatment using radiation therapy, essentially radiation using high-energy particles or waves, may destroy cells that are too small to be seen and removed. Chemotherapy is also used, with powerful anticancer drugs entering the bloodstream with the aim of reaching places that cannot be reached by surgery or radiation therapy, or when the latter may prove fatal to a patient for other reasons. Because of the large number of people who have died from cancer, there are many societies around the world that have been prominent in raising cancer awareness, collecting money for cancer research, and also helping those dying from cancer, as well as their family and friends. The American Society for the Control of Cancer was established in 1911, and was later renamed the American Cancer Society. It and the British Imperial Cancer Research Fund (later renamed the Imperial Cancer Research Society) have been very effective in fund-raising and provid-
ing grants to oncologists. The greater awareness of cancer has also led many philanthropists to donate money for cancer awareness programs and for cancer research and treatment. prevention Over time, it has been shown that the best methods of preventing death from cancer lie in prevention. A healthier diet and lifestyle involving reducing the amount of red meat, eating more fruits and vegetables (especially peas and lentils), eating particular foods in moderation, avoidance of smoking or other high-risk activities, and remaining out of the sun’s direct ultraviolet rays for as much as possible is a clear way of reducing the risk of getting cancer. The other method of preventing death has hinged on early diagnosis. This has involved an awareness campaign about regular tests for breast cancer and Pap smear tests for cervical cancer, as well as tests for colon, rectal, prostate, mouth, and skin cancer, and about having those with symptoms seek treatment early. Those living with cancer have developed techniques of maintaining as normal a lifestyle as possible, with the establishment of many self-help groups and charitable associations. Of course, the level of treatment that is achievable largely depends on the medical services available in the country or area in which a person is living. Although cancer treatment is still difficult to access in many poor countries, its availability has increased dramatically over the last 20 years, with cancer charities raising money for cancer treatment drugs and equipment in many third world countries. SEE ALSO: Cancer Alternative Therapy; Cancer Chemo-
therapy; Cancer—Coping with Cancer; Cancer Radiation Therapy; Oncologist; Oncology. BIBLIOGRAPHY. Nathaniel I. Berlin, “The Conquest of
Cancer,” Perspectives in Biology and Medicine (v.22, 1979); J. Geoffrey Golson and Graham A. Colditz, eds., The Encyclopedia of Cancer and Society (SAGE, 2007); Bernard Glemser, Man against Cancer: Research & Progress (Bodley Head, 1969); Richard Kluger, Ashes to Ashes (Knopf, 1997); James S. Olson, The History of Cancer: An Annotated Bibliography (Greenwood, 1989); James S. Olson, Bathsheba’s Breast: Women, Cancer and History (Johns Hopkins University Press, 2002); L.J. Rather, The Genesis of Cancer: A Study in the History of Ideas (Johns Hopkins University
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Press, 1978); Ronald W. Raven, The Theory and Practice of Oncology (Parthenon, 1990). Justin Corfield Geelong Grammar School, Australia
Cancer Alternative Therapy Because cancer can manifest itself in so many different ways and variations, including the ability to spread or metastasize, it is not surprising that a variety of different forms of treatment are used to combat it. Even when the cancer is susceptible to the use of drugs (chemotherapy) or ionizing rays (radiotherapy), there are likely to be additional symptoms or outbreaks of the disease that require other forms of treatment. These alternative therapies vary significantly in their nature and efficacy with respect to any particular patient. Of course, the best form of treatment is prevention and there are a number of lifestyle factors that can be applied to reduce the risk of cancer: avoiding cigarette smoke, keeping skin protected from the sun, adopting a balanced diet, and so forth. There are also external effects that societies can control to some extent through reducing pollution or changing the forms and patterns of large-scale energy generation or other effects in the environment that can stimulate cancer growth. Because chemotherapy and radiotherapy can provoke often distressing and debilitating side effects, it is important for the patient to be kept in as mentally and physically strong a condition as possible. Appetite and diet management will be one important area in this regard, especially because patients may find their appetite impaired by other forms of treatment. There are, additionally, various forms of alternative or complementary medicine; each have some adherents. Evidence varies as to the efficacy of such treatments, but even those that have very little basis in medical reality may yet carry a psychological value. Therapeutic massage can be used to tackle some types of muscular pain and to strengthen the body and its flexibility. Acupuncture is favored by some as a means of pain management. Some scientists have been experimenting with more effective means of inhibiting cancer cell growth or killing the cells that have been affected.
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Efforts include the search for vaccines that would immunize people to specific cancerous growths and the use of high-temperature (hyperthermia) treatments to tackle cancerous cells. Other research has focused on the use of newly understood types of energy beams or more exotic approaches. SEE ALSO: Alternative Medicine; Cancer (General); Can-
cer Chemotherapy; Cancer—Coping with Cancer; Cancer Radiation Therapy.
BIBLIOGRAPHY. James S. Gordon and Sharon Curtin,
Comprehensive Cancer Care: Integrating Alternative, Complementary, and Conventional Therapies (Perseus, 2001); Ross Pelton, Alternatives in Cancer Therapy: The Complete Guide to Alternative Treatments (Fireside, 1994). John Walsh Shinawatra University
Cancer Chemotherapy Chemotherapy involves the use of chemical compounds to tackle medical problems; cancer chemotherapy, therefore, means the use of such compounds specifically to combat cancer. Some types of remedy work well in tackling some of the many types of cancer that can affect people, but others are less effective. This can be because of the nature of cancer, which causes cells to divide and mutate and thereafter cause problems, while chemicals only affect cells in one particular stage. There is also the problem that cancer can spread and develop into different forms, which means that patients may require a variety of simultaneous treatments and it can be difficult to identify how these treatments will interact with each other and with the patient’s body. Furthermore, the patient may already be in a weak and vulnerable condition and therefore susceptible to side effects of drugs, which can include nausea, hair loss, fatigue, and other symptoms which can themselves be traumatic for patients. Medical advice should always be sought when beginning new forms of treatment and completing the course to the end is very strongly advised in nearly all cases. The need for sterile conditions or to monitor the patient’s response to a cocktail of treatments may
mean that hospital accommodation is advisable. This is especially true when the depletion of white blood cells, which is typical of chemotherapy treatments, intensifies the impact of existing cancer. The form in which chemotherapy treatments are administered varies depending on the nature of the cancer. Ointments, for example, may be applied directly to skin lesions, while injection or oral forms are more common for internal manifestations. The use of gene transfer technology offers some hope for delivering treatments more directly to parts of the body that are otherwise only accessible through invasive surgery. In the modern world, cancer chemotherapy products are almost universally produced by big pharmaceutical companies. Starting a pharmaceutical company generally requires a huge investment of money and the ability to test new drugs for perhaps decades before they can be put on the market. This means that companies tend to be very large and powerful and able to deter competitors from trying to directly compete with them. Because of this, the cost of chemotherapy treatments tends to be high, both
In underdeveloped countries, patients may not be able to afford cancer chemotherapy treatment.
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because of research and development costs and because the company can receive some monopoly benefits. In developed countries in which medical insurance schemes of one sort or another bear the cost of such treatments, the patient receives the treatment, but the cost of insurance overall is high. In countries without such schemes, only wealthy people can afford treatment at all. Research suggests that no matter how well intentioned medical practitioners may be, the cost of treatments has an impact upon which ones are prescribed for or made available to patients. The positive side of this issue is that profitability of possible cures stimulates further research in the corporate sector. SEE ALSO: Cancer (General); Cancer Alternative Therapy;
Cancer Radiation Therapy; Chemotherapy; Pharmaceutical Industry (Worldwide). BIBLIOGRAPHY. Mireille Jacobson, et al., “Marketwatch:
Does Reimbursement Influence Chemotherapy Treatment for Cancer Patients?” Health Affairs (v.25/2, 2006); Roland T. Skeel, Handbook of Cancer Chemotherapy, 7th ed. rev. (Lippincott, Williams & Wilkins, 2007). John Walsh Shinawatra University
Cancer—Coping with Cancer Cancer is one of the most prevalent diseases in the world today, especially in developed countries. Despite recent medical developments in diagnosing and treating cancer that have increased survival rates considerably, people still associate cancer with long-term suffering and death. There are different ways of coping with the diagnosis and treatment of cancer, depending on the psychological and cultural characteristics of patients. Coping with cancer includes two interrelated processes: Coping with the side effects of cancer treatment and coping with the social and psychological changes that the cancer causes in a patient’s life. Having cancer often brings radical changes to a person’s social interactions and position, work and family life, and views on life, health, and sickness. Many sources of patients’ self-esteem can be threatened by cancer
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and the effects of medical treatment, such as their appearance, physical abilities and activity level, personal attributes (such as being independent and healthy), and role and identity within family and work life. Sometimes the side effects of cancer treatment can be more distressing than the cancer itself, and even if those side effects are mostly temporary they affect patients’ emotions and everyday life considerably. Both radiation therapy and chemotherapy have common side effects, which include fatigue, nausea, hair loss, pain, skin problems, mouth and throat difficulties, diarrhea, and constipation. Although new scientific developments, such as effective nausea medications, modify the severity of side effects to some extent, many cancer patients still experience these problems during their treatment. The severity of these problems also depends on the age and general physical condition of the patient. Fatigue is one of the most common side effects of cancer treatment, but it can vary from a mild lack of energy to being completely exhausted. Some patients feel tired after each treatment session, whereas others may have fatigue that lasts for several months after the completion of therapy. In order to cope with this problem, having a good night’s sleep and resting as needed throughout the day are essential. Although light activity is usually beneficial to help patients maintain their energy, and working or doing family duties gives patients the motivation and fulfillment they need, they also have to acknowledge their fatigue and delegate some of those activities. Eating nutritious food and drinking plenty of liquids also helps patients manage their fatigue. As for nausea, antinausea medications help prevent or decrease nausea and vomiting in many people who have cancer treatment. Eating bland foods such as toast and crackers, drinking small amounts of clear liquid frequently, eating cold foods, and wearing loose clothing also help in reducing nausea. Hair loss is one of the most important side effects for many cancer patients, since it affects self-image considerably. Not all of the patients who undergo cancer treatment lose their hair, since only certain chemotherapy and radiation therapy drugs cause this. Doctors always have to warn their patients about this side effect beforehand. Many cancer patients buy a hairpiece or a wig that matches with their actual hair. Some patients also cut their hair very short before
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their treatment, so that the hair loss is not as overwhelming for them. Others may choose to wear bandannas, scarves, or turbans and some do not mind showing their baldness in public, because they believe that it shows that they are strong and unafraid even in the midst of cancer treatment. Loss of an organ, particularly one or both breasts, as a part of cancer treatment is also highly difficult for many female cancer patients to cope with in psychological and social terms. There are various ways of dealing with this problem, such as having breast implants or gaining the ability to live with a new self-image. In many countries, such as the United States and Germany, female breast cancer survivors have proved that their bodies are still aesthetically beautiful by exhibiting art photographs of their bodies. Losing one or both breasts may also affect a patient’s sexual life, and patients have to acknowledge these changes and openly discuss sexuality issues with their partners. Cancer treatment may also limit or put an end to the reproductive abilities of male and female cancer patients, and this may be a major problem in cultures where having children is seen as the main duty of married couples. In those cases, patients have to share this problem with their partners, and couples have to redefine their social roles and reshape sexual life together. Besides the side effects of cancer treatment, accepting the cancer diagnosis and figuring out how cancer fits into a patient’s life is also challenging. Shock is often the first reaction of many cancer patients, because no one is ever prepared to learn that they have cancer, even if they suspected that they had it. Shock may be followed by disbelief, denial, anxiety, guilt, sadness, grief, depression, and anger, in different degrees of severity in different people. Many patients ask the “Why me?” question, wondering why, among all people, they have cancer. There may also be a stigma attached to having cancer, since in many cultures it is assumed that what happens to a person is somehow linked to what the person deserves. Patients may seek professional or spiritual help and the help of loved ones in order to cope with these emotions. Benefiting from the experiences of other cancer patients or survivors and sharing information and advice with other cancer patients are also effective ways of dealing with the stress that is caused by cancer. Medical researchers indicate that most cancer patients’ negative emotions due to their disease are con-
nected to the fear of what is unknown and unpredictable, and in order to deal with this problem, patients have to seek more knowledge about their illness and treatment. This can be in the form of asking a list of questions of their doctors, reading related materials in print and on the internet, and benefiting from other people’s cancer experiences and narratives. By knowing more about their disease and its treatment process, patients can gain a greater sense of control over their situation. Rather than suppressing their negative emotions when healthcare providers and their loved ones tell them to be optimistic and hopeful, patients should try to balance their negative and positive emotions, and try to communicate them openly with their loved ones. Seeking spiritual support or the guidance of religious leaders, benefiting from support groups, and having psychological counseling are the other possible means for cancer patients to open up about their problems and express them appropriately. The Cancer Centers, which are prevalent in large U.S. cities and in European countries, also provide professional psychological help for cancer patients. Patients can chose one of these methods, depending on their character, psychological situation, and social environment. Even keeping a journal can be a good way for patients to express their feelings and give meaning to what they are going through. Some patients even find meaning in their illness that transcends their individual plight, and they turn their illness into a positive lesson about life and health. Keeping up an active social life and maintaining hobbies and work as much as is allowed by the cancer treatment also give patients a greater sense of control over their life and disease. However, acknowledging the side effects of cancer, such as pain and fatigue, and delegating some work and family duties to loved ones are also essential for cancer patients. SEE ALSO: American Cancer Society (ACS); Cancer (Gen-
eral); Cancer Chemotherapy; Psychooncology; Stress.
Bibliography. American Cancer Society, “Coping with
Physical and Emotional Changes: The Emotional Impact of a Cancer Diagnosis,” www.cancer.org (cited March 2005); Andrew Kneier, et al., “Cancer Coping Strategies”, Cancer Supportive Care Programs, www.cancersupportivecare .com (cited September 2004); Mayo Foundation for Medi-
Cape Verde
cal Education and Research, “Living with Cancer,” Mayo Clinic Family Health Book, 3rd ed. (Collins, 2003). Aysecan Terzioglu, Ph.D. City University of New York
Cancer Radiation Therapy Cancer radiation therapy uses ionizing rays such as Xrays, gamma rays, or nuclear particles to kill cells by inhibiting their ability to divide. The control of the rays involved has become very precise and medical practitioners are skilled at shielding the other cells of the body from being affected by the radiation, because it kills all types of cells indiscriminately. Generally, radiation therapy (also known as radiotherapy) is offered to patients in conjunction with surgery and it eliminates those cancerous cells that linger after the surgical procedure has been completed. Given the specialist equipment and training required to offer this treatment, patients must be able to travel to the service center (hospital) and to afford the treatment. Consequently, it is largely limited to the developed world. Radiation therapy was first attempted in 1896 by Emil Grubbe, who was hoping to treat a breast carcinoma, just one year after X-rays were first discovered by Wilhelm Conrad Röntgen. Grubbe, who did not graduate from medical school until 1898, went on to found the world’s first radiation therapy unit in Chicago. The practice has spread rapidly since and has become one of the standard treatments for cancer, together with chemotherapy. Approximately half of all cancer patients who survive the disease do so at least partly because of the impact of radiotherapy. Radiation therapy has a number of possible side effects in addition to the death of tissue, including fatigue, scarring, pigmentation change in the affected skin area, and rashes. Some side effects can be quite traumatic for patients and caregivers. The complete set of side effects varies considerably because of the variety of different types of radiation, the diversity of cell types within a tumor, and their location. However, it should also be borne in mind that comparatively low dosages of radiotherapy, perhaps administered for palliative reasons, may have minimal or no side effects at all. Severe side effects can include hair loss,
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skin dryness, fibrosis of the tissue, and even cancer, because the therapy can also stimulate the production of the disease it is intended to kill. Radiation therapy may be delivered externally, from a suitable machine or, alternatively, from some kind of radioactive implant that can be dispatched to the affected area. The dosage of the radiation also varies for similar reasons and is generally increased to deal with tumors that have more diversified impacts on cells; in some cases, tumors cannot be treated effectively in this way. Internal forms of radiotherapy include interstitial brachytherapy, in which the source of the radiation is placed inside the tumor, as well as endocavitary brachytherapy, in which the radiation source is placed in a body cavity in which tumors may form. Additionally, nonsealed brachytherapy involves the injection of sources into the patient in some specific cases. Advanced mathematical and computer modeling techniques are increasingly being used to determine less invasive and more efficient approaches to planning a program of radiation therapy. Clearly, being subject to radiation therapy is a rather debilitating experience for even the healthiest person and so there is a real need to maximize the efficiency of its use. SEE ALSO: Cancer (General); Cancer Alternative Therapy;
Cancer Chemotherapy; Roentgen, Wilhelm.
Chicago Radiological Society, “Emil Grubbe,” www.chi-rad-soc.org (cited May 2007); Daniel Cukier, Virginia E. McCullough, and Frank Gingerelli, Coping with Radiation Therapy, 3rd ed. (McGraw-Hill, 2001); Steven A. Liebel, Textbook of Radiation Oncology, 2nd ed. (Saunders, 2004). BIBLIOGRAPHY.
John Walsh Shinawatra University
Cape Verde Cape Verde is a small archipelago in the Atlantic Ocean about 500 kilometers off the western coast of Africa. It was uninhabited until the arrival of the Portuguese in the 15th century, who turned it into a main transfer point for their trade routes between Africa, Europe, and the Caribbean. The total landmass for
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the 10 islands and eight islets that make up the chain is roughly the size of Rhode Island. The islands were formed by ancient volcanoes, although only Mount Fogo on Fogo Island remains active today. The population on Cape Verde is 421,000. More Cape Verdeans live outside the islands than on them; there are more than 500,000 in the United States alone. Most young people leave to find work; the unemployment rate for those who stay is 21 percent, and about 30 percent of islanders live in poverty. Those who do find work are generally in the service industry. Food supply is a problem on Cape Verde. The country suffers from drought in many areas and erratic rainfall in others. Eighty-two percent of all food is imported, and high-quality food is out of the reach of many islanders. Diabetes cases are expected to grow from 7,000 in 2000 to 24,000 by 2030. Life expectancy is high compared with continental Africa. The average Cape Verdean male lives to age 67, and the average female to 74. Healthy life expectancy is 59 for men and 63 for women. Child mortality is relatively low, with 35 per 1,000 dying before the age of 1 and 26 per 1,000 dying between the ages of 1 and 5. Ninety-nine percent of women receive prenatal care and 89 percent give birth with the assistance of trained attendants; maternal mortality is 150 deaths per 100,000 live births. Around 50 percent of women have access to birth control. Cape Verde is well insulated from major infectious diseases, and the World Health Organization notes no major outbreaks in recent years. About 90 percent of children receive full immunization. The HIV/AIDS infection rate is believed to be about 0.035 percent, according to 2001 estimates. The islands have a small pool of medical personnel, with 231 doctors and 410 nurses. Government expenditures on healthcare are about $57 per capita. SEE ALSO: Healthcare, Africa. BIBLIOGRAPHY. Central Intelligence Agency, “Cape Verde,”
World Factbook, www.cia.gov (cited March 2007); Joint United Nations Programme on HIV/AIDS (UNAIDS), “Cape Verde,” www.unaids.org (cited June 2007); United Nations Children’s Fund (UNICEF), “Cape Verde—Statistics,” www.unicef.org (cited March 2007); World Health Organization, “Guide to Statistical Information at WHO,” www.who.int (cited March 2007); World Health Organi-
zation, “WHO Global InfoBase,” www.who.int/infobase (cited March 2007). Heather K. Michon Independent Scholar
Carcinoid Tumors A tumor, in general, is an overproduction or an abnormal production of cells. A carcinoid tumor is a slow growing tumor, which is a result of an overproduction of hormone-producing cells. These hormone-producing cells are called enterochromaffin cells. Carcinoid tumors are a type of neuroendocrine tumor, and are the most common type of tumor within the neuroendocrine tumor category. Carcinoid tumors usually originate in the small intestine, and more specifically in the ileum. These types of tumors can be either malignant or benign. In general, the potential for spread and metastasis to the liver increases if the tumor is over two centimeters in diameter. It generally takes three to five years for a carcinoid tumor to grow two centimeters, and in some cases takes up to 10 years. These tumors are not restricted only to the small intestine, but can also occur in places such as the lungs, pancreas, ovaries, or testes. Because these tumors are derived from hormoneproducing cells, the tumor secretes substances that are very similar to hormones such as prostaglandins, histamine, bradykinin, and serotonin. Generally these hormone-like substances do not reach the systemic circulation unless there has been hepatic metastasis. This is due to the fact that if there is no liver involvement, systemic effects will not be seen because a normally functioning, unaffected liver breaks down the excess hormones produced by the tumor. If, however, there has been an excess level of hormones systemically circulating, it can lead to a patient having symptoms that are known as the carcinoid syndrome. About 10 percent of people who have carcinoid tumors will develop carcinoid syndrome. There are a set of clinical features that this syndrome entails: small-bowel obstruction secondary to the tumor; flushing, wheezing, diarrhea, cardiac involvement leading to heart failure and facial telangiectasia; and secondary to hepatic metastases it can cause pain, hepatomegaly, and jaundice.
Within the body, carcinoid tumors would most likely be present growing deep within the mucosa of the organ, and may even be extending into the submucosa underneath. Specifically within the small intestines, carcinoid tumors will often be seen as small nodules growing into the lumen. The tumors will appear brown or yellow, and this is due to the cholesterol and lipid accumulation that is occurring within the tumor. Under a microscope, histologically speaking, carcinoid tumors can be divided into five patterns. The most common type of pattern that has been identified is a combination of the five patterns. Diagnosing a carcinoid tumor can vary depending on the situation. If the tumor is nonfunctioning, as in it is not producing much hormone, then there may be a delay between the actual diagnosis and the onset of symptoms. According to the Carcinoid Cancer Foundation, these nonfunctional tumors can cause a sequence of events such as intermittent abdominal pain, which leads to a change in bowel habits that can lead to intestinal obstruction. In other cases, however, symptoms will not be present until the tumor has metastasized to the liver. This leads to liver enlargement, which causes abdominal pain. If the tumor is a functioning type of tumor, it is easier to diagnose due to the presence of the carcinoid syndrome and accompanying symptoms. Normally when trying to diagnose a carcinoid tumor, the tests completed are urine 5HIAA, serum serotonin, Neuron Specific Enolase, Pancreastatin, Substance P, Pancreatic Polypeptide, and Atrial Naturetic Hormone (ANH). The best treatment for carcinoid tumors is surgical resection if it is possible. This treatment has a very good outcome if the tumor is localized to one area and has not spread to any other areas. Completely removing the overgrowth of tissue can result in a permanent cure. When the tumors are larger and have spread within the local tissue and lymph nodes, the general survival rate is between eight and 23 years. If the person were suffering from the carcinoid syndrome, the treatment would be to remove as much as the primary tumor as possible. Then hepatic metastasis may be removed as the symptoms improve. Normally, a patient is likely to present with this type of tumor in the fifth decade of life. The incidence rate of carcinoid tumors is about 2.0–2.5 per 100,000 people. The most common site for men to develop
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carcinoid tumors is the small intestine, whereas for women the most common location is the appendix. In children, the tumor most commonly appears in the appendix, but is usually benign and occurs without any symptoms. In general, carcinoid tumors are rare, but they may be aggressive, as well as have the capacity to spread to other areas of the body. The areas which carcinoid tumors are likely to metastasize to are the liver, mesenteric lymph nodes, ovaries, peritoneum, and the spleen. About 20 percent of people with small intestinal carcinoid tumors will develop distant metastasis. Risk factors for developing this type of tumor are a family history of carcinoid tumors, a patient who has multiple endocrine neoclassic type 1, and persons with some types of stomach diseases are said to have an increased risk as well. SEE ALSO: Cancer (General); Carcinoma of Unknown Pri-
mary; Liver Cancer.
Bibliography. J.R. Anderson and B.G. Wilson, “Carci-
noid Tumors of the Appendix,” British Journal of Surgery (v.72/7, 1985); I.P. Kema, P.H. Willemse, and E.G. De Vries, “Carcinoid Tumors,” The New England Journal of Medicine (v.341/6, 1999); Cameron Tebbi, “Carcinoid Tumors,” www. emedicine.com (cited July 2006); Richard Warner, “A Review of Carcinoid Tumors,” www.carcinoid.org (cited July 2006). Angela Garner, M.D. University of Missouri–Kansas City
Carcinoma of Unknown Primary Physicians encounter patients with metastatic cancer frequently in practice. Although often, the etiology of the cancer and the impaired organ are obvious, occasionally the diagnosis of carcinoma of unknown primary is encountered. Because cancers tend to migrate to lymph nodes, a biopsy result of this type presumes metastatic cancer as, typically, this tissue diagnosis has come from a pathologic review of an identified abnormal lymph node. It is also possible that at the time of presentation of the abnormal lymph node, the primary tumor is still at a subclinical level, making diagnosis of the primary cancer even more difficult.
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This biopsy result means one is unable to distinguish the primary site of the tumor, although it does imply there has been metastatic spread. Specific drainage patterns of the lymph system are known, so often the location of the abnormal lymph node can assist in diagnosing the etiology of the carcinoma. When a diagnostic biopsy demonstrates unknown primary tumor site with cervical lymphadenopathy, or enlarged lymph nodes in the neck area, it accounts for just under 5 percent of all head and neck cancers. The majority of patients with metastatic cervical lymphadenopathy often have squamous cell carcinoma or poorly differentiated carcinoma. Adenocarcinoma is rarely identified in a metastatic lymph node in the cervical region. When present, adenocarcinoma in the cervical lymph nodes can indicate a primary cancer found in the salivary glands, sinuses, thyroid, and parathyroid glands. More commonly, these histologically glandular primary cancers are located below the clavicles, including gastrointestinal tract, lung, and breast. The diagnostic evaluation of a patient with an unknown primary tumor includes a complete history and physical examination. A specific history of tobacco, alcohol, sun exposure, occupational exposure should be obtained, as they are also known risk factors for certain types of cancer. Chronic unintentional weight loss, fever of unknown origin, chronic cough, or localized pain to any area of the body may help with the diagnosis and search of the etiology of the cancer. In addition, a chest radiograph should be obtained, as well as a computed tomography (CT) scan, and possibly additional plain radiographs, depending upon the location of the abnormal lymph node. Recently, positron-emission tomography (PET) scans have been considered as an adjunct in the evaluation of carcinoma of unknown primary. Theoretically, tumor cells have a higher metabolic rate than normal tissue, which suggests abnormal cells accumulate more of the tracer used in a PET scan. This uptake or “hot spot” may help locate the primary malignant site. Unfortunately, there are limits to PET scans. Lesions smaller that one centimeter may be too small for the resolution of certain PET scan machines and may be missed. In addition, certain tumors do not uptake the tracer consistently, while other tissues in the body may absorb the tracer, as seen in inflammation or normal tissues such as the kidney and bladder. At this point, PET scanning is not
considered standard of care for screening, because it is neither reliable nor cost effective. Blood tests are an additional piece of the diagnostic process. Depending upon coexisting medical problems, it is reasonable to obtain a complete blood count, electrolyte panel, and assessments of liver function and kidney function. Hemoccult testing of stool should be considered and prostate-specific antigen (PSA) should be obtained in male patients, as well as consideration for serum tumor markers. Although certain tumor markers are helpful in monitoring response to therapy and relapse, they are not useful in the general population for screening, due to insufficient sensitivity and specificity. However, in the situation of carcinoma of unknown primary, they should be considered. See also: Cancer (General); Lymphatic Diseases; Skin
Cancer.
BIBLIOGRAPHY. Elizabeth J. Mahoney and Jeffrey H. Spie-
gel, M.D., “Evaluation and Management of Malignant Cervical Lymphadenopathy with an Unknown Primary Tumor,” Otolaryngologic Clinics of North America (v.38/1, 2005); Greg L. Perkins, et al., “Serum Tumor Markers,” American Family Physician (v.68/6, 2003). Ann M. Karty, M.D., FAAFP Kansas City University of Medicine and Biosciences
Cardiologist A cardiologist is a medical doctor who specializes in treating diseases affecting the heart, arteries, and veins. Cardiologists are responsible for the medical management of ailments including congestive heart failure, valvular heart disease, and peripheral vascular disease. Patients are usually first referred to cardiologists from a primary care physician once a complex diagnosis affecting the heart is made. At the initial visit, the cardiologist inquires about the patient’s symptoms to gather information about the patient’s illness. The cardiologist then performs a thorough cardiovascular exam in which he or she listens carefully for flow abnormalities, or irregular heartbeat patterns.
Cardiology
Often, cardiologists perform electrocardiograms (ECG), echocardiographs (echo), blood tests, or chest radiographs to gain further insight into the disease process. An ECG measures the electrical activity of the heart while a Doppler echo allows the cardiologist to create sound waves to produce an image of the heart and view the blood flow through the heart. Cardiologists also perform stress treadmill tests to help elucidate how the heart responds to increased exertion. In patients with persistent chest pain, a cardiac catheterization may be performed to view the heart and its blood supply. Under the guidance of a televised viewing screen, the cardiologist inserts a small catheter into the femoral artery of the thigh. The catheter is threaded into the heart and the pressure and blood flow is measured. A contrast dye is then injected into the blood vessels to visualize any blocked vessels. If there are numerous partially or completely occluded vessels, the cardiologist is likely to consult a cardiothoracic surgeon to perform a surgical bypass operation. This operation replaces the diseased heart blood vessels with veins from the lower leg. Cardiologists also prescribe medications to decrease the likelihood of cardiovascular events including heart attack and stroke. Cardiologists working in private practice or hospitals must undergo several years of education and training. Individuals must first complete four years of undergraduate education, four years of medical school training, and three years of internal medicine residency at accredited institutions. The individual then passes the Internal Medicine Board Certification examination and begins three additional years of fellowship training in general cardiology. After passing the examination for board certification in cardiovascular diseases, he or she may pursue a subspecialty in interventional cardiology, electrophysiology, or nuclear cardiology or may simply begin his or her practice as a general cardiologist. The path toward pediatric cardiology is very similar. Individuals also obtain an undergraduate and medical degree, but then complete a pediatric medicine residency and a fellowship in pediatric cardiology. The average annual salary for cardiologists is $200,000 depending on location and expertise. SEE ALSO: America Heart Association (AHA); Heart At-
tack; Heart Diseases; Healthcare, U.S. and Canada; Internist.
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BIBLIOGRAPHY. American College of Cardiology, “What
Is a Cardiologist?” (cited February 2007); American Heart Association, “How Cardiologists Diagnose Heart Defects,” www.americanheart.org (cited February 2007); Durham Regional Hospital, “Cardiologist,” www.durhamregional.org (cited February 2007); Texas Heart Institute, “What Is a Cardiologist?” www.texasheartinstitute.org (cited July 2006). Stephanie F. Ingram University of South Florida
Cardiology Cardiology is the branch of medicine concerned with the heart and blood vessels, known as the cardiovascular system. It encompasses a wide variety of disorders related to different parts of the heart and the vascular system. A physician who specializes in cardiology is called a cardiologist. ���������������������� In the Western world, cardiology is an ever-growing field within internal medicine. Extensive studies have identified risk factors for heart disease, including diabetes mellitus and obesity. Both are on the increase within the general population and this will inevitably lead to increased incidence of heart disease, even with growing public awareness of these health matters. In a recent publication, Julie������������������������� Gerberding�������������� , director of the Centers for Disease Control and Prevention (CDC), highlighted the fact that over 70 million Americans have cardiovascular disease and that cardiovascularrelated deaths account for 40 percent of annual deaths. It has been estimated that the cost of heart disease and stroke, including lost productivity, was $403 million in 2006. This figure is set to rise annually as the general population ages and larger numbers of this group have age-related cardiovascular problems. The first physician to describe the blood vessels was William Harvey, an English physician, in 1628. In 1706 a French anatomist, Raymond de Vieussens, first characterized the structure of the heart chambers and valves. These two key contributions allowed a major work, considered to be the true beginning of the field of cardiology, to be written. In 1749, Jean-Baptiste Sénac����������� published Traité de la structure du coeur, de son action, et de ses maladies (Treated structure of the heart, of its action,
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and of its diseases). The publication discussed the physiology and anatomy of the heart and even discusses some heart diseases that are still present today. When the stethoscope was invented in 1816 by René Laënnec, the art of auscultation, a key tool in the study of the heart, took off. There have been many advances in cardiac medicine and surgical procedures. In 1952, John F. Lewis at Northwestern University in Evanston, Illinois, performed the first successful open heart surgery. Not long after, Christiaan Barnard performed the first whole-heart transplant in 1967, at Groote Schuur Hospital, Cape Town, South Africa. He continued to pioneer further developments in cardiology. In 1982, the first permanent artificial heart was implanted into a human by William DeVries and Robert Jarvick. In 2006 various trials began looking at injecting stem cells into hearts damaged following myocardial infarction (heart attack) to see whether they can repair the damage. In the United States, training to become a cardiologist is very competitive. Physicians graduate from medical school as a doctor of medicine; this is usually a four-year program. They then go on to an internal medicine program of three-year duration. On completion of this program, they then progress to a cardiology fellowship, which usually lasts another three years, although the whole process can last up to eight years with research included. On completion of the licensing examinations, including regional licensing examinations, the physician will then be a qualified cardiologist. He or she may then stay within the field of cardiology or branch out to teach, conduct research, or even go on to become a cardiovascular surgeon. The Heart and its diseases The heart is a vital organ whose purpose is to pump blood around the body, thereby providing a source of oxygen to muscles and organs, and to clear away waste products from metabolism. The arterial system is made up of blood vessels that carry oxygenated blood, the largest of which is the aorta. Arteries become smaller arterioles and then capillaries, which allow the exchange of oxygen and waste products at organs and muscles. These then become venules and finally form larger veins in the venous system. The heart itself needs its own blood supply and receives this via the coronary arteries.
The heart can be said to be a double pump, divided into the right heart and the left heart. The right heart is at a lower pressure and receives blood from the venous system via the superior and inferior vena cava. Blood passes from these vessels to the right atrium and through to the right ventricle via the tricuspid valve; the right ventricle then pumps the blood through the pulmonary valve into the lungs. Once in the lungs, the blood is oxygenated and then passes to the left heart through the pulmonary veins. Once in the left atrium, the blood has entered the systemic system. The blood is pumped into the left ventricle through the mitral valve. Once in the left ventricle, it is pumped through the aortic valve into the aorta. Both sides of the heart pump in unison in a healthy person, and this coordinated pumping action is maintained via electrical activity innate to the cardiac muscle cells. This pumping action is what propagates the blood pressure, which can be felt as a palpable pulse. Blood pressure needs to be maintained at a fairly constant level in order to keep the blood flowing through the blood vessels and prevent too much strain being placed on the heart. Blood pressure is made up of two numbers, the higher or systolic value indicates the pressure propagated when the ventricle contracts and pumps blood into the aorta and is ideally 120 mmHg. The lower value, or the diastolic value, is the pressure during the relaxation phase and is around 80 mmHg in a healthy individual. Blood pressure is measured using a sphygmomanometer. There are many diseases associated with the heart and cardiology covers them all. However, the most commonly seen heart disease in the Western world is ischemic heart disease (IHD). This is when the heart muscle does not receive enough oxygen from the blood in the coronary arteries to maintain its level of activity, and so there is a mismatch between demand and supply. This leads to a condition known as angina pectoris, in which the individual experiences well-defined chest pain when the heart muscle is not receiving enough oxygen through the coronary arteries. This can often escalate and eventually lead to a myocardial infarction, where an affected area of heart dies because it has not received enough oxygen through the coronary arteries. The main cause for IHD is atherosclerosis of the coronary arteries caused by an abnormal inflammatory response associated with elevated cholesterol levels. There are many risk
factors, but the most significant are diabetes mellitus, hypertension, smoking, high cholesterol, and family history indicating predisposition. Most cardiologists advocate the use of a statin to lower cholesterol, and aspirin in those at risk, and also encourage cessation of smoking and regular exercise with weight loss. Congestive cardiac failure is commonly seen in older people and is characterized by breathlessness and some degree of fluid overload seen as swollen ankles. It is due to the heart being unable to pump effectively to maintain the cardiac output and is usually secondary to IHD in the Western world. Diagnostic Tests and Pharmacological Agents In the field of cardiology, there are key tools and tests that are used by cardiologists worldwide to aid diagnosis and response to treatment. The stethoscope is a crucial instrument and is used to listen to the closure of the valves within the heart chambers. The clo-
Cardiology is an growing field. Diabetes and obesity are both are on the rise and will lead to increased incidence of heart disease.
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sure of the semilunar valves produce the first heart sound heard as “lub” and the second heart sound is down to the closure of the semilunar valves, which produce the “dub.” If there are extra sounds or a murmur, which is due to turbulence of blood flow over the valves, then the timing with respect to the heart sounds can be used to aid diagnosis. For example, the presence of a third heart sound on auscultation in children and young adults is not unusual, but the presence of a third heart sound in elderly adults can be the first sign of heart failure. In 1903, Willem Einthoven described the electrocardiogram (ECG), for which he won the Nobel Prize for Medicine in 1924. This important tool is primarily based on detecting the contraction of the cardiac muscle, which is associated with electrical changes known as depolarization. These can be picked up by attaching electrodes to the surface of the body. Within the right atrium of the heart, there is an area known as the sinoatrial node (SAN), which is where the electrical discharge begins for each cardiac cycle. This electrical activity then propagates through the atria to the atrioventricular node (AVN); the electrical activity then spreads rapidly down the bundle of His (hiss) between the ventricles and then separates to spread around the apex of each ventricle to lead to ventricular contraction. This completes the cardiac cycle, and in the electrical context, it can be thought of as being made up of two separate chambers: the atria, which pump synchronously, and the ventricles, which also pump synchronously. This repetitive cardiac cycle leads to an ECG with distinctive wave forms for each part of the cardiac cycle. The P wave is due to the atria contraction, QRS complex is down to ventricular contraction, and the T wave is down to the ventricular relaxation. The transverse portions of the ECG such as the PR interval indicates the time for the electrical activity to travel from the SAN to the AVN. The ST interval is an isoelectric phase and its elevation or depression can indicate myocardial infarction and myocardial ischemia, respectively. The ECG can also be used to indicate possible cardiomyopathy, atrial and ventricular hypertrophy, pericarditis, pulmonary embolus, and abnormal heart rhythms and extra beats. If a patient is suspected of suffering from IHD, then he or she may have ECG and blood pressure monitoring while walking on a treadmill, known as an exercise
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treadmill test. This is a commonly used outpatient procedure conducted in cardiology departments worldwide. If a patient is unable to safely have an exercise treadmill test, then he or she may alternatively have a myocardial perfusion scan. This is where a dye is injected into the coronary arteries and the blood supply of the myocardium can be visualized to look for any narrowing or blockages. If there is some degree of narrowing, then the usual treatment is angioplasty, usually with a balloon to open up the narrowed vessel, or if the narrowing is very severe then the vessel can be kept open with a narrow stent. These both open the vessel and allow blood flow to return to the underperfused area of the heart and increase the oxygen supply, thereby preventing angina. Common agents used in cardiology are angiotensin converting enzyme inhibitors (ACE-I), betablockers, calcium channel blockers (CCB), diuretics, and nitrates. ACE-I are used in hypertension and post-MI as it protects ventricular muscle from detrimental changes. Beta-blockers and CCB are used in hypertension and diuretics are used in hypertension and to clear fluid in heart failure. Nitrates are vasodilators used in angina. In the Western world, cardiovascular disease is the biggest killer, but with more health education, the mortality rate may be reduced. It is inevitable that this field will continue to grow and develop and the role of the cardiologist will become even more invaluable to society. SEE ALSO: Angina; Arteriosclerosis; Cardiologist; Heart
Attack; Heart Bypass Surgery; Heart Diseases (General); Heart Diseases—Prevention; Heart Transplantation; Heart Valve Diseases. BIBLIOGRAPHY. A. Bowman, “Jean-Baptiste Senac and His
Treatise on the Heart, Historical Perspectives in Cardiovascular Medicine & Surgery,” Texas Heart Institute Journal (v.14, 1987); The Franklin Institute’s Resources for Science Learning, “Milestones in Cardiology,” www.fi.edu/biosci (cited February 2007); Julie Louise Gerberding, Heart Disease and Stroke: The Nation’s Leading Killers (Centers for Disease Control and Prevention, 2006); Punit Ramrakha and Jonathan Hill, Oxford Handbook of Cardiology (Oxford University Press, 2006). Yasmin Kaur St. Matthew’s University
Cardioversion In order for the heart to work effectively, it needs to pump in a controlled and regular rhythm, with coordination between the atria and ventricles. If these cease to work in unison, then the result in the worst case scenario may be death, depending on the type of arrhythmia. Cardioversion is the procedure used to convert an abnormal heart rhythm or arrhythmia to a normal or sinus heart rhythm. There are two types of cardioversion: The first uses pharmacologic agents and the second uses direct current. Depending on the type of arrhythmia, the stable patient will usually be offered a pharmacologic agent prior to being offered electrical cardioversion. There are many antiarrhythmic pharmacologic agents that work by various mechanisms to try to modify the heart rhythm and return it to sinus. However, the term cardioversion usually refers to electrical cardioversion. This can be an emergency procedure on an unconscious patient in ventricular fibrillation (VF) or ventricular tachycardia (VT); this is called defibrillation. It can also be an elective procedure, referred to as direct current cardioversion, for a patient failing to respond to antiarrhythmic pharmacologic interventions or with a case of recent onset that may respond to a direct electrical shock. The patient will be brought in as an elective day case and will be made nil by mouth. The patient will be put under general anesthesia and will be anesthetized for the whole duration. Two electrical pads are placed on the front of the chest under the right clavicle and on the back of the patient on the left side, or a wire can be passed into the heart and the heart is directly shocked. The patient is under electrocardiogram (ECG) monitoring throughout and the pads are directly connected to a machine that delivers a certain amount of shock at the correct time according to the ECG. The electrical shock has to be delivered on the R-wave of the ECG; failure to do this may induce a ventricular arrhythmia that can be fatal. The energy level applied varies; 100 joules is used for atrial fibrillation and 200 joules for VF/VT. Once the patient is ready to be shocked, the machine synchronizes and prepares to deliver the shock. The shock only lasts a few milliseconds. The heart momentarily stops and the hope is that it will be reset in normal sinus rhythm. Another shock can be given at a higher energy value if the heart is unresponsive.
Caregivers
Following the shock, the patient will need to have ECG monitoring in recovery. As with all procedures, there are some risks, the main one being dislodging emboli, which may travel in the arterial system to the brain and lead to a stroke. Therefore, only new onset arrhythmic patients are offered cardioversion. The patient will usually be followed up to ensure that there are no adverse complications and to make certain that they do not become arrhythmic once again, which is also a known risk. SEE ALSO: Arrhythmia: Cardiology; Heart Attack; Heart
Diseases (General); Heart Disease Prevention.
BIBLIOGRAPHY. Carsten W. Israel and S. Serge Barold,
eds., Advances in the Treatment of Atrial Tachyarrhythmias: Pacing, Cardioversion, and Defibrillation (Blackwell, 2001); Murray Longmore, Ian B. Wilkinson, and Supraj R. Rajagopalan, Oxford Handbook of Clinical Medicine (Oxford University Press, 2004). Yasmin Kaur St. Matthew’s University
Caregivers Caregiving is the help provided to someone who is unable to live independently and who needs assistance with eating, bathing, or dressing. The definition of caregiver is anyone who provides assistance to an older adult or someone with a disability. Informal caregivers are unpaid individuals who care for a family member or friend. Worldwide, female family members, such as wives and adult daughters, are the primary caregivers to the aged and those in frail health. The care can be at home or may be informal care in a long-term care setting. As the global economy changes and as more women enter the labor market, informal caregiving has become more of a challenge throughout the world. Past research on informal caregivers has focused on caring for the aged, in particular those with Alzheimer’s disease or dementia. This research has shown that caregiving can negatively impact on the caregiver’s psychological health due to increased stress, burden, and depression. Caregivers contend with time constraints, financial pressures, family tensions, and
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employment concerns. In addition, caregivers exhibit poorer physical health. Previous research has shown that race, older age, employment status, and inadequate social support increase the caregiver’s risk for poor health outcomes. Caregivers experience many different processes in caring for a frail family member, including identifying a diagnosis, finding support, and decision making about treatment and the location of long-term care. When looking at caregiving cross-culturally, past research has shown that the meaning and process of caregiving are influenced by culture, socialization, and religion. Paying respect and providing for elderly parents are values that are common throughout the world. For example, among Thai caregivers of chronically ill relatives, caregiving was seen as a willingly accepted burden and an unavoidable duty, attitudes that are clearly influenced by Buddhist beliefs. In a study of family caregivers of Alzheimer’s patients in China, cultural ideals promoting family interdependence, veneration of elderly family members, and acceptance of traditional family roles reduced the psychological impacts of caregiving. At the same time, cultural barriers can also prevent respite care for the caregiver. In a study of Asian-American caregivers, personal issues, such as caregivers feeling unwilling or too proud to accept outside help, provided barriers to care for the caregiver. SEE ALSO: Alzheimer’s Caregivers; Alzheimer’s Disease;
Elder Abuse; Geriatrics.
BIBLIOGRAPHY. H. Li, “Barriers to and Unmet Needs
for Supportive Services: Experiences of Asian-American Caregivers,” Journal of Cross-Cultural Gerontology (v.19/3, 2004); Y. Limpanichkul and K. Magilvy, “Managing Caregiving at Home: Thai Caregivers Living in the United States,” Journal of Cultural Diversity (v.11/1, 2004); M. Navaie-Waliser, et al., “When the Caregiver Needs Care: The Plight of Vulnerable Caregivers,” American Journal of Public Health (v.92/3, 2002); T.L. Patterson, et al., “The Cultural Context of Caregiving: A Comparison of Alzheimer’s Caregivers in Shanghai, China and San Diego, California,” Psychological Medicine (v.28/5, 1998). Grace Yoo Mai Nhung Le San Francisco State University
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Carotenoid
Carotenoid Carotenoids are naturally occurring pigments that are found in plants and other photosynthetic organisms such as algae and some bacteria. Approximately 600 carotenoids have been identified, 50 of which are consumed by humans. The vital role that carotenoids play as accessory pigments in photosynthesis has been an active area of research for many years. In addition, some carotenoids are metabolic precursors to retinol in humans, and thus have important health roles in the prevention of vitamin A deficiency, one of the most important nutrient deficiencies on a worldwide level. Carotenoids are widely distributed in plants, including fruits and vegetables, where they account for most of the red/orange/ yellow colors in these foods. Many of the carotenoids ingested from foods are absorbed and accumulate in human blood and tissues. Whether non-provitamin A carotenoids have health effects in humans is not clear. Carotenoids are generally classified into two categories, the carotenes (hydrocarbon carotenoids) and the xanthophylls (oxygenated carotenoids). The most well-known carotenes include alpha- and beta-carotene, found in carrots, and lycopene, found in tomato products. The most well-known xanthophyllic carotenoids include lutein and zeaxanthin, which are found in deep-green leafy vegetables such as spinach, and cryptoxanthin, found in oranges. Carotenoids serve an important antioxidant function in plants and photosynthetic organisms; whether they serve a similar antioxidant function in humans is less clear. Some chronic conditions such as cancer, age-related macular degeneration, and aging are thought to result from oxidative stress. Many epidemiological, mechanistic, and clinical studies are actively investigating whether people who consume more carotenoids (from food or supplemental sources) have a reduced risk of developing chronic disease. As an example, the human macula (part of the retina) specifically concentrates two of the carotenoids found in human blood, lutein, and xeaxanthin. Recent evidence suggests that higher concentrations of these two pigments (obtained from diet) in the macula may protect against photo-induced damage, reducing the risk of macular degeneration. Human supplementation trials are currently underway to evaluate this hypothesis. Another carotenoid that has been of particular interest for its health effects is lycopene. Many, but not
all, epidemiological studies find that persons with greater lycopene intake/status are at lower risk of developing chronic diseases, including prostate cancer. This relationship is promising but not yet convincing. The only carotenoid that has been evaluated in long-term supplementation trials in humans for disease prevention is beta-carotene. It was hypothesized that this carotenoid might help to reduce the incidence of lung and other tobacco-related cancers, as cigarette smoking is known to be a potent oxidative stressor. Results showed that contrary to the hypothesis, supplementation with high-dose beta-carotene increased lung cancer incidence in high-risk populations (e.g., smokers). It is now recognized that carotenoids, particularly at high concentrations, can form breakdown products with unexpected physiological effects. Based on these findings, it is generally advised that humans obtain carotenoids from foods rather than from supplements, with correspondingly lower exposures. Exceptions to this are for prevention of vitamin A deficiency in at-risk populations, and in the setting of clinical trials (e.g., for age-related macular degeneration), with careful monitoring for health risks and benefits. SEE ALSO: Age-Related Macular Degeneration; Chemo-
prevention; Nutrition; Vitamin and Mineral Supplements.
BIBLIOGRAPHY. George Britton, Synnove Liaaen-Jen-
sen, and H.P. Pfander, eds., Handbook of Carotenoids, (Birkhauser Verlag, 2004); Norman I. Krinsky, Susan T. Mayne, and Helmut Sies, eds., Carotenoids in Health and Disease (Marcel Dekker, 2004). Susan T. Mayne Yale University
Carpal Tunnel Syndrome Carpal tunnel syndrome (CTS) is the most common compressive neuropathy (pressure on a nerve causing symptoms) and is characterized by pain, tingling, numbness, weakness of the fingers, and/or muscle wasting. Anything putting pressure on the median nerve in the carpal tunnel may cause these symptoms. Traditional treatments include antiinflammatory
medications, splints, steroid injections, or surgery. Alternative treatments include emu oil, osteopathic manipulative treatment (OMT), acupuncture, and yoga. The prognosis varies and depends upon the severity, but most patients with mild-to-moderate CTS without muscular atrophy (muscle wasting) will respond well to nonsurgical interventions. Narrowing of the carpal tunnel (through which the median nerve and tendons pass) is the anatomical basis for the disease. The tunnel is comprised of carpal bones on three sides, and the transverse carpal ligament on the other. Factors increasing pressure within the tunnel (and the median nerve) include pregnancy, edema (excess fluid), and inflammatory arthritis, as well as repetitive wrist movements, such as those associated with typing, gardening, and house painting. The elevated pressure causes decreased blood flow to the median nerve, and impairs nerve conduction. CTS is three times more common in females and usually presents after the age of 30. Patients are commonly awakened at night by painful numbness in the hands that they may try to alleviate by shaking their hand and rubbing their fingers. The fingers commonly affected are the thumb, index, and middle fingers, as they are supplied by the median nerve. Patients also may report dropping objects or weakness of the first three fingers. Daytime attacks usually are elicited by any activity that causes wrist flexion, such as car driving or holding a telephone. Physical examination may be normal, but in advanced cases, the patient may have weakness and atrophy. Two commonly performed tests include Phalen’s maneuver and Tinel’s sign. Phalen’s maneuver involves holding the patient’s wrists in flexion for 60 seconds. A positive test is one that elicits pain or sensory changes in the first three fingers. Tinel’s sign is evaluated by tapping on the wrist crease in the area of the median nerve/carpal tunnel. A positive sign causes pain and or sensory changes. An electro myelogram with nerve conduction studies may also be used to determine the health of the nerve. Common treatments of CTS include nonsteroidal antiinflammatory drugs (NSAIDs), corticosteroids, splinting, and surgery. Splints may be used with other treatments, and many patients report relief within days. Nighttime splints prevent wrist flexion, and should be a first-line choice for patients with mildto-moderate CTS. NSAIDs and corticosteroids treat
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the inflammation of the median nerve as well as surrounding structures. Corticosteroids are often given as an injection into the region of the carpal tunnel. Candidates for surgery include patients with constant numbness, symptoms for over a year, or muscle weakness and wasting. The surgery, carpal tunnel release, involves cutting the transverse carpal ligament to increase tunnel size. A patient considering surgery should seek a second opinion to confirm the diagnosis, and choose a capable surgeon who performs many CTS surgeries. Patients who develop CTS during pregnancy should never have surgery, as CTS usually will resolve after childbirth. Several alternative therapies for the treatment of CTS are available. Osteopathic manipulative treatment (OMT) can elongate the transverse carpal ligament in cadavers, and may be of benefit to patients with CTS as well. These nonthrusting stretching techniques have little risk, can be done at home, and appear to improve symptoms. Many botanicals, including willow bark, St. John’s wort, grape seed extract, arnica, garlic, and flaxseed oil have also been used by patients to treat symptoms of CTS. Results have been mixed, and more data are needed to substantiate claims. Topically applied emu oil has been shown to be helpful in small studies. Acupuncture for CTS has not been evaluated in a controlled study. One study revealed eight weeks of twice-weekly yoga to be of benefit, with patients demonstrating a significant reduction in pain and improvement in grip strength. Ergonomic therapies may reduce or prevent symptoms of CTS. These techniques involve behavior modification, and use of devices such as an ergonomic keyboard. A multifaceted approach, with identification and removal of precipitating factors, must be taken to successfully treat this condition. SEE ALSO: Hand Injuries and Disorders; Occupational In-
juries; Peripheral Nerve Disorders; Wrist/Arm Injuries and Disorders. BIBLIOGRAPHY. R.H. Gelberman, et al., “Carpal Tunnel
Syndrome: A Scientific Basis for Clinical Care,” Orthopedic Clinics of North America (v.19, 1988); J.N. Katz, et al., “Maine Carpal Tunnel Study: Outcomes of Operative and Nonoperative Therapy for Carpal Tunnel Syndrome in a Community Based Cohort,” Journal of Hand Surgery (v.23, 1998); Robert P. Sheon, “Treatment of Carpal
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Tunnel Syndrome,” www.UpToDate.com (cited October 2006); J.C. Stevens, et al., “Carpal Tunnel Syndrome in Rochester, Minnesota, 1961 to 1980,” Neurology (v.38, 1988); B.M. Sucher, “Myofascial Release of Carpal Tunnel Syndrome,” Journal of the American Osteopathic Association (v.93/1, 1993). Gautam J. Desai, D.O. Aaron J. Douglas Kansas City University of Medicine and Biosciences Ashley J. Dalton, Pharm.D. University of California San Diego Medical Center Kathleen M. LaFavor, D.O., M.B.A. Creighton University
Casals-Ariet, Jordi (1911–2004) Jordi Casals-Ariet was a Spanish-born American physician and viral epidemiologist who discovered the Lassa fever virus in 1969, along with many other viruses throughout his career. He helped classify about 1,000 viruses, establishing their taxonomies. Casals nearly died in the process of discovering the Lassa virus in his laboratory at Yale. Casals was born in Vialadrau (Girona), Spain. He earned his bachelor’s degree in Barcelona where he attended medical school. In 1936, he became a visiting investigator at the Rockefeller Institute for Medical Research in New York City. Casals spent two years in the Department of Pathology at Cornell University Medical College and then returned to the Rockefeller Institute as a staff member. In 1964, his unit was moved to Yale University, and he spent the rest of his career in New Haven, Connecticut. At the same time, he also carried out research at Mount Sinai School of Medicine in New York City, where his last scientific paper was published in 1998. He died on February 10, 2004. It was at Yale that Casals and his team detected a new virus in the blood of three American missionary nurses who had worked in northern Nigeria. The virus was named after the place where it was first found, the Lassa village in Nigeria. The discovery of
the virus was followed by laboratory accidents that endangered the health of Casals and his colleagues, leading to the establishment of new standards of laboratory safety. After the discovery of the Lassa virus, recommendations for more rigorous precautions concerning the isolation of sick passengers were also issued. Casals collaborated with hundreds of scientists around the world and was renowned for his scientific accuracy and his professional ethics. For his contribution to virology, he received the Richard M. Taylor Award in 1969. He also received the Kimble Methodology Award from the American Public Health Association. Casals served as consultant to many important institutions including the Walter Reed Army Institute of Research, the World Health Organization, the Armed Forces Epidemiology Board, the U.S. National Institutes of Health, the American Committee on Arthropod-borne Viruses and the International Committee on Taxonomy of Viruses. Casals was also elected to many national and international scientific societies such as the New York Academy of Sciences, the Belgian Society of Tropical Medicine, the French Society of Microbiology, and the Royal Society of Tropical Medicine and Hygiene. SEE ALSO: Biological and Chemical Weapons; Biosafety;
Fever; Travel Medicine; Viral Infections; Virology.
BIBLIOGRAPHY. Lawrence K. Altman, “Jordi Casals-Ar-
iet, Who Found the Lassa Virus, Dies at 92,” New York Times (February 21, 2004); Jeanne Lenzer, “Jordi CasalsAriet,” British Medical Journal (v.328/7445, 2004). Luca Prono Independent Scholar
Cascade A biochemical cascade is an instance when there are a series of chemical reactions in which the products of one of the reactions lead to subsequent reactions. These have been very important in biochemistry with enzymatic cascades involving the treatment of coagulation. However, for most doctors, it is the allergic cascade that is of the greatest importance.
Case-Control Study
An allergic cascade occurs when a person is allergic to a specific item and faces a cross-reaction when their immune system reacts to another item that the body identifies as the first. This becomes particularly important when a person is trying to work out exactly what they are or are not allergic to. If, for example, a person is allergic to rye, but because of his or her diet, the only time he or she comes across rye in the diet is in bread that contains gluten. The body’s immune system may link the two together, and as a result, if the person eats something with gluten but without rye, it is possible for an allergic reaction to result if there has been an allergic cascade. This is actually far more common than has been previously thought, especially as there are medical tests that people can take to identify allergies and identify levels of the body’s intolerance to specific items in the diet. SEE ALSO: Allergy; Celiac Disease; Food Allergy. BIBLIOGRAPHY. Stephen F. Kemp and Richard F. Lockey,
eds., Diagnostic Testing of Allergic Disease (Clinical Allergy & Immunology, Volume 15) (Informa Healthcare, 2000); Burton Zweiman and Lawrence Schwartz, eds., Inflammatory Mechanisms in Allergic Diseases (Clinical Allergy & Immunology, Volume 16) (Informa Healthcare, 2001).
Justin Corfield Geelong Grammar School, Australia
Case-Control Study Case-control studies are a fundamental study design used in epidemiology. This nonexperimental, or observational, study design ascertains the differences in suspected exposures between individuals with a disease of interest (“cases”) and comparable individuals who do not have the disease (“controls”). Analysis yields an odds ratio (OR) that reflects the relative probabilities of exposure in the two populations. Case-control studies can be classified as retrospective or prospective, depending on when cases are identified in relation to measurement of exposures. The case-control study was first used in its modern form in 1926, but grew in popularity in the 1950s following the publication of several seminal case-control stud-
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ies carried out by Sir Richard Doll and others that established the link between smoking and lung cancer. Case-control studies are advantageous because they require smaller sample sizes and thus fewer resources and less time than other observational studies. This design is the only viable option for studying exposure related to rare diseases, for diseases that are a consequence of long exposure, and is an ideal design for conditions that potentially result from multiple exposures. The primary challenges in designing a case-control study lie in appropriate selection of cases and controls, with the objective of minimizing confounding, or the differential distribution of exposures that are due to factors other than disease status. Steps can be taken in the study design and analysis to minimize confounding. A well-designed study must include controls that are selected from the same source population from which cases are selected. Additionally, cases and controls may be “matched” by relevant characteristics that might otherwise result in a biased estimate of the association between disease and exposure. With reference to analysis, multivariate analysis, usually logistic regression, allows the primary association between exposure and disease to be “adjusted” for the effect of measured confounders. Bias might also result if exposures cannot be measured or recalled equally in both cases and controls. Choosing from a population with a disease different from the one of interest but of similar morbidity may minimize that probability, as these individuals are more likely to recall exposures or to have their information recorded to a level comparable to cases. Care must also be taken in interpreting the results of a case-control study. Odds ratios are not equivalent to absolute risk difference, although given a rare-enough exposure, OR is considered to be nearly equal. SEE ALSO: Cohort Study; Epidemiology; Prospective
Study; Retrospective Study.
BIBLIOGRAPHY. Kenneth Rothman and Sander Green-
land, eds., Modern Epidemiology (Lippincott Williams & Wilkins, 1998); James Schlesselman, Case-Control Studies: Design, Conduct, Analysis (Oxford University Press, 1982). Constance W. Liu, M.D. Case Western Reserve University
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Cataract
Cataract Cataract is the single leading cause of blindness worldwide. It is caused by the opacification (clouding) of the crystalline lens within the eye. Luckily, the disorder can usually be corrected by surgical removal of the clouded lens and, if possible, replacement of the old lens with a synthetic one in order to restore proper sight. Cataract can be classified by its cause, stage, or anatomical classification. While age-related cataract is most frequently observed, other common forms of cataract include congenital, traumatic, or complicated. Congenital cataracts are present from birth or develop very early in life, necessitating early removal of the clouded lens in order to allow for proper development of the infant’s sensitive visual system. Eye trauma from accidents or injuries can also cause cataracts to form in the eye. Complicated cataracts develop when other eye diseases—such as glaucoma, retinitis pigmentosa, retinal detachment, or uveitis— affect the physiology of the lens. Cataract classifications based on stage include immature, mature, hypermature, and morgagnian cataract. While immature cataracts still have some transparent protein left, mature cataracts are often easily recognizable because all proteins have become opaque. Hypermature cataracts progress so far that their proteins become liquid; if the nucleus (center) of the lens floats freely in the lens capsule’s “bag,” the
Nuclear cataracts begin at the center of the lens; the cloudiness grows from the center and negatively affects vision.
cataract is classified as morgagnian and should be removed immediately. Finally, cataracts may also be classified by their anatomy. Nuclear cataracts begin at the center of the lens; as the cataract progresses, the cloudiness grows from the center and changes the lens color, negatively affecting vision. Cortical cataracts are whitish opacities that begin on the outer edges of the lens and gradually grow to the center, interfering with proper lens function. Subcapsular cataracts develop in the back of the lens and quickly begin to block light from passing through the lens onto the retina. There are several key risk factors for cataract; while some of these are unavoidable, others are important to note because they may help reduce the huge global backlog of people in need of cataract surgery. The biggest risk factor for cataract is age; worldwide, at least some opacification of the lens occurs in 50 percent of people over age 60 and 100 percent of people over age 80. Studies reveal that females are slightly more likely to develop cataract than males. Diabetes and other health complications can not only cause eye diseases such as diabetic retinopathy, but may also increase the risk of developing cataract. The two most easily preventable risk factors for cataract are ultraviolet (UV) light exposure and smoking. Harmful UV radiation from the sun damages the lens and expedites the process of opacification. It is strongly recommended that all people, regardless of age, wear UV-resistant sunglasses outside during bright days. However, due to poverty and lack of education in many countries, sunglasses are rarely, if ever, used by most of the population. Another preventable but often ignored risk factor for cataract is smoking. Smoking releases permanently damaging free radicals within the body, increasing the risk of cataract formation. Because most cataracts progress slowly and painlessly, changes in vision may be too gradual to notice until the cataract is more fully developed. Patients with cataract usually complain of blurry vision, halos around sources of light, difficulty seeing at night, faded colors, and quickly changing eyeglass prescriptions. Diagnosis of cataract includes a visual acuity screening followed by a more thorough examination possibly involving dilation of the pupils in order to observe the entire lens. Treatment of cataract involves surgical removal of the opaque lens. The ophthalmologist makes an in-
Celiac Disease
cision near the edge of the cornea, or colored part of the eye, through which he or she makes another incision in the anterior capsule, which contains the lens. The old lens is broken up and aspirated out of the eye in phases. A newer, safer technique called phacoemulsification uses a tiny ultrasonic vibrator to disintegrate the hard nucleus of the lens. Phaco emulsification is quicker and requires a smaller incision than regular surgery. Following cataract extraction, a synthetic intraocular lens (IOL) may be inserted through the same incision into the “capsular bag” that contained the old lens. Since the lens is important for focusing light onto the retina, lens replacement essentially restores the patient’s sight to pre-cataract conditions. Without an IOL, the patient requires significant refractive correction in order to make up for aphakia (lack of lens). Unfortunately, many patients in third world countries are too poor to afford IOLs and must depend on very thick eyeglasses in order to see properly after cataract surgery. After surgery, patients may experience some difficulty with night vision. As with any surgery, complications are rare but possible; overall, however, cataract surgery is a quick and inexpensive means of essentially restoring sight to a blind person. While cataract is not life threatening and can be easily treated, it enormously impacts millions of people’s lives. Globally, the need for cataract surgery in the world is staggering. While programs are under way to provide surgery for those who need it, the backlog of cataracts is growing. In 1999, the global need for cataract surgery was over 30 million people annually; however, only 10 million operations a year were performed. It is estimated that the number of cataract blind will increase to approximately 50 million people by 2020. Poverty and associated factors such as poor nutrition, poor hygiene, and lack of access to education or healthcare all appear to significantly influence the prevalence of cataract. Surgical treatment may be quick, inexpensive, and relatively free of complications, but the challenge is to provide such treatment to the growing millions who need it. SEE ALSO: Eye Care; Eye Diseases (General); Ophthalmol-
ogist; Ophthalmology.
BIBLIOGRAPHY. Christopher Hammond, “The Epidemi-
ology of Cataract,” Optometry Today (February 9, 2001);
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Susan Lewallen and Paul Courtright, “Blindness in Africa: Present Situation and Future Needs,” British Journal of Ophthalmology (v.85, 2001); Mayo Clinic, “Cataracts,” www.mayoclinic.com (cited November 2006); Paul Riordan-Eva and John P. Whitcher, General Ophthalmology, 16th ed. (McGraw-Hill, 2004). Nakul Shekhawat Vanderbilt University
Celiac Disease Celiac disease, also called gluten-induced enteropathy or nontropical sprue, is a disorder of impaired nutrient absorption in which intolerance to the protein gluten causes damage to the small intestine, leading to malnutrition and growth failure. Antibodies against gluten, a protein found mainly in wheat, rye, oats, and barley, destroy the lining or epithelium of the small intestine, which is normally responsible for nutrient absorption as digested food passes through the gastrointestinal tract. The clinical manifestations and degree of symptoms among celiac patients are believed to correlate with the extent of damage to the small intestinal lining. Classic symptoms include diarrhea, bloating, vomiting, loss of appetite, fatigue, and even irritability. In many cases, short stature or growth failure can precede these other signs of malnutrition or gastrointestinal disease. Removal of gluten-containing food products from the diet, within a few weeks to months, can dramatically improve a patient’s well-being by eliminating symptoms and protecting against further destruction to the small intestinal epithelium. If left untreated, however, celiac disease can have severe and even life-threatening complications, including osteoporosis, central and peripheral nerve disorders, lack of dental enamel formation, infertility, and intestinal lymphoma. It is estimated that anywhere from one in 150 to one in 250 people worldwide has celiac disease. Although celiac disease can affect an individual of any age or gender, women are three times as likely to be affected as men. However, the variable clinical presentations among those affected—ranging from no symptoms to severe disease and growth failure—suggest a higher incidence than reported, with many cases remaining
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undiagnosed. Most cases appear primarily in whites of northern European ancestry; however, there appears to be increasing incidence among African and Asian populations in recent years. Presentation and diagnosis of celiac disease appears to peak in two age groups—that is, between the ages of 1 and 4, and again after 50 years of age. Healthy epithelium of the small intestine is characterized by small hair-like projections, or villi, that are responsible for nutrient absorption. The specific damage in celiac disease occurs to the villi, which become partially or completed flattened. This flattening interferes with nutrient absorption, which can lead to malnutrition and growth failure. Classically, celiac disease is characterized by the presence of villous atrophy—which leads to malabsorption manifest by symptoms such as weight loss and nutrient or vitamin deficiency—and the resolution of epithelial lesions and amelioration of symptoms upon removal of gluten-containing foods. People can be screened for celiac disease with blood testing for antibodies specific to the disease. Antibodies to endomysium, a component of smooth muscle connective tissue, and to tissue transglutaminase, a protein within endomysium, are highly sensitive and specific for celiac disease. These antibodies are present in high levels in more than 90 percent of people with untreated celiac disease and are rarely found in those without celiac disease. While levels, or titers, of these antibodies can provide a presumptive diagnosis of celiac disease, a tissue sample, or biopsy, of the small intestine remains essential for definite diagnosis. The antibody titers may also be useful in monitoring clinical response to a gluten-free diet. As patients completely remove gluten from their diet, there is a reduction in the amount of antibodies present, and this response to treatment can be followed over time. Blood levels of endomysial and tissue trans glutaminase antibodies may even become negative in patients strictly adhering to a gluten-free diet. Celiac disease falls under the category of auto immune diseases. More commonly known auto immune conditions include type 1 diabetes mellitus, rheumatoid arthritis, and thyroid dysfunction. It has been widely established that having one autoimmune condition is predisposing for another. Thus, patients with celiac disease should be screened particularly for type 1 diabetes mellitus and autoimmune thyroid dis-
ease. Type 1 diabetes mellitus is a disorder characterized by an inadequate or complete lack of insulin, a hormone in the body that helps transport sugar molecules into cells to be converted to energy. Autoimmune thyroid disease occurs when a person develops antibodies that attack and damage the thyroid gland, interfering with the synthesis and release of thyroid hormone. Thyroid hormone has critical functions in almost all tissues of the body, and is important for growth and development, internal temperature regulation, and food metabolism. It is also recommended that patients with one of these autoimmune conditions be screened for celiac disease even if asymptomatic. Other conditions that are more common in those with celiac disease include dermatitis herpetiformis, Down syndrome, depression, fatigue, neurologic diseases, arthritis, and liver disease. In fact, it is believed that almost 70 to 80 percent of those who present with dermatitis herpetiformis, a severe itchy blistering rash localized to the arms, legs and torso, also have coexisting intestinal damage demonstrated on tissue biopsy. These symptoms can be treated with a gluten-free diet. There appears to be a strong association between Down syndrome and celiac disease, with the prevalence of celiac disease almost 20-fold higher in patients with Down syndrome when compared to the general population. SEE ALSO: Autoimmune Diseases (General); Diabetes
Type 1 (Juvenile Diabetes); Inflammatory Bowel Disease; Thyroid Diseases.
BIBLIOGRAPHY. J.H. Cummings and N. McGough, “Celiac
Disease: A Diverse Clinical Syndrome Caused by Intolerance of Wheat, Barley and Rye,” Proceedings of the Nutrition Society (v.64/4, 2005); P.H. Green and B. Jabri, “Celiac Disease,” Annual Review of Medicine (v.57, 2006). Charitha Gowda Duke University School of Medicine
Cellulitis Cellulitis is a common bacterial infection of the skin that occurs because of a break in the skin barrier that allows organisms to invade. It leads to inflammation
Centenarian
of connective tissue that is characterized by a reddening of skin with feeling of warmth and tenderness to the affected area. This can take place locally or, if serious, can affect the rest of the body and be potentially life threatening. Generally, cellulitis is a condition that ensues in the extremities, but it can occur anywhere on the body. Risk factors include a disruption of the skin, blood vessel or lymphatic disorders, or a history of previous cellulitis. Breaks in the skin are commonly caused by trauma such as a cut, fungal infections of the feet that cause cracking and drying, or foot ulcers that frequently occur in diabetic patients. Disorders of the blood vessels or lymphatic system can occur in people who are overweight or pregnant. This can also occur in people with venous insufficiency, meaning one’s veins are not able to properly return blood back to the heart, causing pooling of blood. Because these conditions lead to less blood flow in the extremities, less cells of the immune system will be delivered by the blood to fight infection. This infection is a clinical diagnosis, meaning it is diagnosed based on signs and symptoms of the patient and does not necessitate laboratory testing in most individuals. The hallmark local features around the injury are edema (swelling), erythema (redness), warmth, and tenderness. Also, the margins of redness usually are not demarcated. Without these classical features, it is strongly suggestive that the diagnosis is not cellulitis. Commonly, this can affect the lymphatic system that is responsible for returning fluid to the blood. Lymph nodes around the area can be tender and enlarged, and lymphangitis can be evident (visible as red ascending streaks on the skin). Lymphangitis is strongly suggestive of cellulitis, but the absence of it does not rule out the diagnosis. The patient can also form an abscess (appearing as pus-filled cavity in an attempt by the body to wall off infection). If the infection affects the rest of the body or becomes systemic, patients can experience fevers, chills, fatigue, and myalgias (muscle aches); the illness can look similar to the common flu. Usually, the bacterium that causes this infection is either Staphylococcus aureus or beta-hemolytic streptococci. Less commonly, other organisms can be involved in dog or cat bites, puncture wounds, or in an open wound exposure to fresh- or saltwater. It is appropriate to treat this empirically with antibiotics, meaning the patient is given an antibiotic that will
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treat the most common cause relating to their exposure. Blood or skin cultures are used only in those with systemic illness, recurrent cellulitis or risk factors for recurrent illness, atypical exposures, or for those who do not improve with treatment. SEE ALSO: Edema; Impetigo. BIBLIOGRAPHY. Larry M. Baddour, “Epidemiology, Clinical
Features and Diagnosis of Cellulitis,” www.utdol.com (cited February 2007); “Cellulitis,” MedlinePlus, U.S. National Library of Medicine and the National Institutes of Health, www.nlm.nih.gov/medlineplus/ency/article/000855.htm (cited August 2007). Erin Eisenhardt Angela Garner, M.D. University of Missouri–Kansas City
Centenarian A centenarian is a person of extreme longevity who has passed the barrier of 100 years of age, an age far superior to the average lifespan in any country. Because of their extreme survival, centenarians have been the subjects of many scientific studies. Stories of extreme longevity have emerged from many different cultures and times. In ancient Greece, with its healthy Mediterranean diet, culture of physical activity, and sanitation, a person who could escape trauma or dying in childbirth could have lived to 100. Today, the number of centenarians is increasing along with aging populations. The United States is a good example of this phenomenon—it has the highest number of centenarians in the world, numbering about 55,000; the number of centenarians in the United States is expected to surpass 800,000 by 2050. This is far more than the approximately 450,000 centenarians estimated to be alive in the world today. Gerontological researchers are interested in identifying longevity factors by studying centenarians. This research has already helped scientists to identify genetic causes for longevity, such as genes that regulate immune and inflammatory responses, lipid metabolism, and insulin signaling pathways. Concerning their morbidity profile, centenarians have in common the
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delay of or escape from the most lethal age-related diseases, and can be classified into three groups: those surviving potentially lethal diseases with onset prior to their 80th birthdays, those delaying such diseases’ onset after the age of 80, and those escaping them altogether. Apparently, longevity strategies may vary between men and women, because they distribute unevenly into these groups. Much more than a populational curiosity, centenarians represent the potential of human longevity and are themselves important sources of knowledge about longevity-related factors. SEE ALSO: American Geriatrics Society (AGS); Geriatrics. BIBLIOGRAPHY. M. Capri, et al., “The Genetics of Human
Longevity,” Annals of the New York Academy of Science (v.1067, 2006); J. Evert, et al., “Morbidity Profiles of Centenarians: Survivors, Delayers, and Escapers,” Journals of Gerontology. Series A, Biological Sciences and Medical Sciences (v.58/3, 2003); C. Franceschi, et al., “Genes Involved in Immune Response/Inflammation, IGF1/Insulin Pathway and Response to Oxidative Stress Play a Major Role in the Genetics of Human Longevity: The Lesson of Centenarians,” Mechanisms of Ageing and Development (v.126/2, 2005); L.A. Gavrilov and P. Heuveline, “Aging of Population,” in Paul Demeny and Geoffrey McNicoll, eds., The Encyclopedia of Population (Macmillan Reference USA, 2003). Thiago Monaco, M.D., Ph.D. University of São Paulo Medical School, Brazil
Center for Food Safety and Applied Nutrition (CFSAN) The Center for Food Safety and Applied Nutrition (CFSAN) operates under the auspices of the Food and Drug Administration (FDA), which became independent of the U.S. Department of Agriculture in 1862. The FDA regulates the safety of food, cosmetics, drugs, biologics, medical devices, and radiological products. According to a designated division of responsibilities, CFSAN works with FDA field staff to protect the nation’s food and cosmetic supplies, applying standards of safety, sanitation, and truth in labeling. CFSAN also works with international organizations and foreign governments to enforce these
standards upon food and cosmetic products that are imported into the country. CFSAN offices are located at 5600 Fishers Lane in Rockville, Maryland. Information is available by telephone (800-463-6332) or at the CFSAN Web site (www.cfsan.fda.gov). The center maintains research facilities in Laurel, Maryland, and Dauphin Island, Alabama, and AFSAN headquarters for two joint ventures are housed near Chicago, Illinois. The center has more than 800 employees. At the technical end, they include chemists, microbiologists, toxicologists, food technologists, pathologists, molecular biologists, pharmacologists, nutritionists, epidemiologists, mathematicians, and sanitarians. Other employees serve as administrators and support staff. The center provides information and advisory services not only to American consumers, but also to domestic and foreign industries, field workers, and government and civic organizations. In order to carry out its mission, CFSAN works with academicians, health providers, and various government agencies to regulate the safety of drugs and cosmetics and to educate the public about safe handling and use of these products. CFSAN activities involve collaborative research projects such as the Joint Institute for Food Safety and Applied Nutrition (JIFSAN) operated in conjunction with the University of Maryland and the National Center for Safety and Technology (NCFST) carried out in cooperation with the Illinois Institute of Technology. Through these efforts, CFSAN is able to generate more effective safety measures. Current safety measures include inspecting establishments that produce or handle food, collecting and analyzing food samples, monitoring imported foods, carrying out premarket reviews of food products, communicating with relevant individuals and groups, conducting consumer studies and focus groups, engaging in laboratory research, and implementing studies on food processing, packing, and biotechnology. Information on food safety is available at www.foodsafety.gov. The U.S. Congress identifies cosmetics as products that are introduced into or on the body for the purpose of cleansing, beautifying, promoting attractiveness, or altering the appearance. The definition also applies to components of such products, with the exception of soap. Cosmetic products are prohibited from containing materials that may cause harm to consumers because they are poisonous, deleterious, or composed of material that is filthy, putrid, or decomposed. Unsafe
Centers for Disease Control and Prevention (CDC)
color additives are also banned, and federal regulations stipulate that packaging of cosmetics must take place in a sanitary manner. Cosmetics are considered misbranded if labels contain incorrect, incomplete, false, or misleading information. Ongoing center activities involve public service announcements that alert the public to food and cosmetic issues that may negatively affect their health. Each December, for instance, the center cautions consumers that raw eggs may contain Salmonella enteriditis (SE). Consumers are cautioned not to eat unbaked cookie dough or to drink eggnog that has not been treated to destroy bacteria. The center also keeps consumers up to date about possible outbreaks, such as the recent Escherichia coli outbreak that struck patrons at Taco Bell restaurants in the northeast and the norovirus outbreak that occurred among guests at an Oregon party who had eaten raw, frozen oysters on the half-shell imported from South Korea. See also: Bioterrorism; E. Coli Infections; Food and
Drug Administration (FDA); Foodborne Diseases; Food Contamination/Poisoning; Food Safety; Nutrition.
BIBLIOGRAPHY. Center for Food Safety and Applied Nu-
trition, www.cfsan.fda.gov (cited January 2007); Sandra A. Hoffmann and Michael Taylor, eds., Toward Safer Food: Perspectives on Risk and Priority Setting (Resources for the Future, 2005); Kenneth J. Meier and Laurence J. O’Toole Jr., Bureaucracy in a Democratic State: A Government Perspective (Johns Hopkins University Press, 2006); Stanley T. Omaye, Food and Nutritional Toxicology (CRC Press, 2004); Barbara Rasco and Gleyn E. Bledsoe, Bioterrorism and Food Safety (CRC Press, 2005); Dennis D. Riley, et al., Bureaucracy and the Policy Process: Keeping the Promises (Rowman & Littlefield, 2006). Elizabeth R. Purdy, Ph.D. Independent Scholar
Centers for Disease Control and Prevention (CDC) Operating through the Department of Health and Human Services, the Centers for Disease Control and Prevention (CDC) protects the health of the nation
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through promotion, prevention, and preparedness and plays a major role in improving public health globally. CDC is based at 1600 Clifton Road, NE, in Atlanta, Georgia. Information is provided though a toll-free number (800-311-3435) and through the agency Web site (www.cdc.gov/). What is now CDC began on July 1, 1946, as Malaria Control in War Areas (MCWA), with only a single, small building and a few hundred employees. Entomologists and engineers provided the expertise needed to destroy malaria-carrying mosquitoes with DDT, and some 58 percent of the original workload was concentrated on this single function. With a budget of less that $10 million, CDC employed only seven medical officers. Today, CDC’s area of operations has expanded to include preventing and controlling all infectious and chronic diseases, injuries, workplace hazards, disabilities, and environmental threats. CDC researchers and investigators perform essential functions by identifying factors that threaten health and by shaping national and international agendas to eliminate or mitigate threats to public health. The CDC budget has expanded to $8 billion (fiscal year 2005), and the agency employs a staff of approximately 15,000. CDC facilities were expanded in September 2005 with the addition of four new buildings. The CDC has the capability to respond to national and world crises at a moment’s notice. The goal of promoting global health though prevention and control of disease, injury, and disability is accomplished through the dissemination of information and collaborations with government and civic organizations in the United States and abroad. CDC activities include monitoring health, identifying and investigating health threats, conducting research, developing policies, implementing strategies aimed at prevention and control, promoting healthy lifestyles and behaviors, protecting environmental health, and supplying leadership and training on health-related issues. The CDC is made up of several facilities dedicated to performing specific functions, and its laboratories are state of the art. The Global Communications Center, which functions as a training institution for public health professionals, also includes a visitor education center and conference and distance learning facilities. The Emerging Infectious Diseases Laboratory is probably the best known of all CDC facilities, for it is there that research is conducted on life-threatening infectors such as Ebola, viral hemorrhagic fevers, monkeypox,
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and avian influenza. The main headquarters building of CDC houses the Office of the Director, the Emergency Operations Center, and the Office of Terrorism Preparedness and Emergency Response. In the Environmental Health Laboratory, scientists conduct research on environmental toxins and develop new diagnostic and prevention methods. Since the terrorist attacks on the United States on September 11, 2001, responding to potential bioterrorist activities has been a high priority at CDC. Recommendations from the Government Accounting Office led CDC to hire seven chief management officials who have been charged with improving operations and evaluating progress. Other changes included reassigning more than 600 employees from administrative positions to research and field work, slashing administrative costs by more than $83 million, consolidating 40 hotlines into one contact center, restructuring human resources to eliminate 76 jobs, consolidating the technology infrastructure at a savings of $23 million, and streamlining management levels. As part of the reform process, CDC’s governing process was transformed into a network. The Executive Leadership Board assumed responsibility for science, programs, and operations policies. The Management Council was charged with implementing strategies and making recommendations about fiscal management and agency operations. The Center Leadership Council was assigned the task of overseeing scientific and public health programs. The Division Director’s Council and the Steering Committee were designated as advisers to other governing bodies. Day-to-day activities at CDC are coordinated through the Office of the Director, who oversees the activities of the various programs. The Coordinating Center for Environmental Health and Injury Prevention is made up of the National Center for Environmental Health/Agency for Toxic Substances and the Disease Registry and National Center for Injury Prevention and Control. The Coordinating Center for Health Information and Services is composed of the National Center for Health Statistics, the National Center for Public Health Informatics, and the National Center for Health Marketing. The Coordinating Center for Health Promotion is comprised of the National Center for Birth Defects and Development Disabilities, the National Center for Chronic Disease Prevention
and Health Promotion, and the Office of Genomics and Disease Prevention. Other CDC agencies include the Coordinating Center for Infectious Diseases, which is made up of the National Center for Infectious Diseases, the National Immunization Program, and the National Center for HIV, STD, and TB Prevention. The Coordinating Office for Global Health is responsible for all activities dealing with international health activities, while the Coordinating Office for Terrorism Preparedness and Emergency Response is concerned with preparedness and emergency responses. The National Institute for Occupational Safety and Health focuses on health issues in the workplace. CDC works with the Agency for Toxic Substances and Disease Registry in an administrative capacity. The CDC Foundation, an independent offspring of CDC, works with the private sector on issues of concern to public health. See also: Agency for Toxic Substances and Disease Reg-
istry (ATSDR); Department of Health and Human Services (DHHS); National Center for Chronic Disease Prevention and Health Promotion (NCCDPHP); National Center for Environmental Health (NCEH); National Center for Health Marketing (NCHM); National Center for Health Statistics (NCHS); National Center for HIV/AIDS, STD, and TB Prevention (NCHHSTP); National Center for Infectious Diseases (NCID); National Center for Injury Prevention and Control (NCIPC); National Center for Public Health Informatics (NCPHI); National Center on Birth Defects and Developmental Disabilities (NCBDDD); National Institute for Occupational Safety and Health (NIOSH). BIBLIOGRAPHY. Centers for Disease Control and Preven-
tion, www.cdc.gov (cited January 2007); Centers for Disease Control and Prevention, “Agency Leadership Taking Steps to Improve Management and Planning, but Challenges Remain” (Government Accounting Office, 2004); Department of Health and Human Services, et al., CDC Injury Research Agenda (Department of Health and Human Services, 2002); Lynda S. Doll, et al., Keeping America Healthy: CDC Prevention Research Partnerships (U.S. Public Health Service and Department of Health and Human Services, 2002); Scott F. Dowell and Alexandra M. Levitt, Protecting the Nation’s Health in an Era of Globalization: CDC’s Global Infectious Disease Strategy (Department of Health and Human Services and Centers for Disease Control and Prevention, 2002); Kenneth J. Meier and Laurence J. O’Toole,
Centers for Medicare and Medicaid Services (CMS)
Jr., Bureaucracy in a Democratic State: A Government Perspective (Johns Hopkins University Press, 2006); Dennis D. Riley, et al., Bureaucracy and the Policy Process: Keeping the Promises (Rowman and Littlefield, 2006). Elizabeth R. Purdy, Ph.D. Independent Scholar
Centers for Medicare and Medicaid Services (CMS) The Centers for Medicare and Medicaid Services (CMS), which operates under the auspices of the Department of Health and Human Services , implements the activities of specified social service programs as mandated by federal law. The mission of CMS is to deliver up-to-date health insurance coverage that provides quality healthcare for all beneficiaries. Medicare and Medicaid were established in 1965 as part of President Lyndon B. Johnson’s War on Poverty. Medicare covers individuals who are 65 or older, or who have certain disabilities, or who have end-stage renal disease, a condition in which patients suffer permanent kidney failure that requires regular dialysis or a transplant. Medicaid is a state-administered program for low-income individuals and families. Disbursement is made directly to healthcare providers and, according to state requirements, may involve a nominal copayment. In 2003, the Medicare Modernization Act supplemented Medicare health benefits with prescription drug coverage. Information on CMS is available through a toll-free number (877-267-2323) or via the internet (www.cms.hhs.gov). CMS is headquartered at 7500 Security Boulevard, Baltimore, Maryland, 21244. In addition to national headquarters and various field offices, CMS maintains facilities in the Hubert H. Humphrey Building in Washington, D.C. Ten regional offices provide direct services to beneficiaries, and regional staffs work with healthcare providers and state and local governments to implement Medicare, Medicaid, and the State Children’s Health Insurance Program (SCHIP). Puerto Rico and the Virgin Islands are covered by the New York office, and American Samoa, the Northern Mariana Islands, and Guam are handled by the San Francisco office. The needs of Native Americans and Native Alas-
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kans are met through ongoing consultation with tribal leaders who collaborate with CMS to ensure that native populations are provided with quality healthcare through access to Medicare, Medicaid, and SCHIP. Originally, the Medicare and Medicaid programs were housed separately under the Social Security and Social and Rehabilitative Services Administrations, respectively. Because CMS works with vulnerable populations, ensuring continuity of services during natural disasters, inclement weather conditions, and various emergencies is essential. The ability of the CMS to do this was put to the test when beneficiaries in Louisiana, Mississippi, and Alabama were faced with the consequences of Hurricanes Katrina and Rita in late 2005. Evacuees from New Orleans were dispersed around the country, and continuation of services was integral to survival as well as to the quality of life. The Congressional Affairs Group in the Office of Legislation serves as a liaison between the U.S. Congress and beneficiaries of CMS programs. Three congressional committees have authorization responsibility for CMS: House Ways and Means, House Energy and Commerce, and Senate Finance. When requested, CMS organizes briefings on relevant issues. The Office of Legislation is directly responsible for responding to congressional recommendations and concerns, developing legislative strategies, holding public hearings on issues of concern to the CMS constituency, developing, analyzing, and reviewing healthcare initiatives, and fostering effective relationships with Congress, the White House, and other government agencies. CMS activities are monitored through the Comprehensive Error Rate Testing Program, Medicaid Payment Error Rate Measurement, and Recovery Audit Contractors. Research activities focus on actuarial studies, assessments of healthcare providers, consumer-related topics, healthcare financing, and health outcomes. Data on the Medicare and Medicaid programs are generated in part through the Medicare Contractor Provider Satisfaction Survey and the Medicare Current Beneficiary Survey. see also: Department of Health and Human Services
(DHHS); Medicaid; Medicare.
BIBLIOGRAPHY. Lori Achman and Linsday Harris, Early
Effects of the Medicare Modernization Act: Benefits, Cost Sharing, and Premiums of Medicare Advantage Plans
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(AARP Public Policy Institution, 2005); Lu Ann Aday, At Risk in America: The Health and Health Care Needs of Vulnerable People in the United States (Jossey-Bass, 2001); Centers for Medicare and Medicaid Services, America, Pull Up a Chair: We’ve Got Something Good to Talk About: Introducing Medicare Rx Prescription Drug Coverage (Centers for Medicare and Medicaid Services, 2005); Centers for Medicare and Medicaid Services, www.cms.hhs.gov (cited January 2007); Jessica Greene, et al., How Much Do Health Literacy and Patient Activation Contribute of Older Adults’ Ability to Manage Health? (AARP Public Policy Institute, 2005); Marion Ein Lewin and Stuart Altman, eds., America’s Health Care Safety Net: Intact but Endangered (National Academy Press, 2000). Elizabeth R. Purdy, Ph.D. Independent Scholar
Central African Republic The United Nations recently described the Central African Republic as “the world’s most silent crisis.” A landlocked country bordered to the east by Sudan, Chad, and the Democratic Republic of the Congo, the Central African Republic has had to cope with the spillover of neighboring conflicts while dealing with a low-level internal conflict that has led to the displacement of 1 million citizens by 2006. Even before the increase in hostilities, the Central African Republic was one of the 10 poorest nations in Africa, with 66 percent of the population living on less than $1 a day. The population is 4.3 million, with an average annual growth rate of 1.53 percent. The birth rate is 33.81 births per 1,000 people, and the death rate is 18.65 per 1,000 people. The migration rate is zero. About 45 percent of Central Africans live in urban areas. Life expectancy is low, averaging less than 44 years, with healthy life expectancy estimated at 37 for men and 38 for women. The formal economy is based on agriculture, particularly the cultivation of staple crops such as cassava, peanuts, maize, and cotton. The Central African Republic is known to have a widespread informal economy based on the illegal export of diamonds, ivory, bushmeat, and other banned items. Poaching
has led to a serious loss of biodiversity in one of the world’s last great wildlife refuges. Access to clean water is 75 percent nationwide, and only 27 percent of citizens have access to sanitary facilities. Gastrointestinal diseases are common. Malaria and tuberculosis are the most serious infectious diseases in the Central African Republic; the country also lies squarely in the African meningitis belt. Recent years have seen outbreaks of polio and shigellosis. Only about one-third of epidemiological reporting sites are operating, making it difficult to track or handle emerging outbreaks. Infant mortality is 115 per 1,000 births, with another 193 deaths per 1,000 for children between the ages of 1 to 5. The immunization rate is around 30 percent for the most common childhood diseases. Malnutrition is widespread, with 3 percent of children under 5 classified as severely malnourished. Almost 60 percent of Central African children are in the workforce before the age of 14, and 57 percent are married by the age of 16. Civil unrest, low adult life expectancy, and the expanding AIDS crisis has left a large orphan population, estimated at 330,000 in 2005. Literacy rates are low, especially among females. Female genital mutilation is widely practiced in the Central African Republic, with about 36 percent of girls having undergone the procedure, either type I (circumcision, or the removal of the clitoral hood) or type II (excision, the removal of the clitoris and labia). Access to contraception is low, with only 28 percent of women using birth control. The fertility rate is 4.8 births per women. There is a shortage of trained birth attendants, with 44 percent of births occurring under supervision, and only 62 percent of women receiving prenatal care. Maternal mortality is high, with 1,100 maternal deaths per 100,000 live births. AIDS has become a significant public health problem in the Central African Republic in recent years. With only 11 testing and counseling sites in place at the end of 2005, the true dimensions of the spread of the human immunodeficiency virus (HIV) are not known, but the estimated rate of infection is 15 percent for the capital city of Bangui, 13 percent in other urban areas, and 17 percent in rural areas. An estimated 300,000 Central African adults currently live with the disease. Young women have been the hardest hit by the epidemic, with an estimated 17 percent of women overall, and 15 percent of pregnant women,
Cerebral Palsy
currently infected with HIV. Treatment plans designed by the government and nongovernmental organizations are proving difficult to implement, given the internal security situation and the general poor quality of health services throughout the country. Access to healthcare is minimal. Annual government expenditure on health is about $12 per capita. There is one medical center for every 6,000 people, or one bed for every 1,095 patients. Facilities are obsolete, and much medical equipment has been looted or destroyed in ongoing internal conflicts. Public healthcare workers can go unpaid for up to 40 months. There are 331 doctors, 1,200 nurses, and 519 midwives for the population of 4.3 million. SEE ALSO: AIDS; Healthcare, Africa. BIBLIOGRAPHY. Central Intelligence Agency, “Central Af-
rican Republic,” World Factbook, www.cia.gov (cited June 2007); Joint United Nations Programme on HIV/AIDS (UNAIDS), “Central African Republic,” www.unaids.org (cited June 2007); Researchafrica.rti.org, “Sub-Saharan Africa—Central African Republic,” researchafrica.rti.org (cited June 2007); United Nations Children’s Fund (UNICEF), “Central African Republic—Statistics,” www.unicef. org (cited June 2007); World Health Organization, “Guide to Statistical Information at WHO,” www.who.int (cited June 2007); World Health Organization, “WHO Global InfoBase,” www.who.int/infobase (cited June 2007). Heather K. Michon Independent Scholar
Cerebral Palsy Cerebral palsy refers to a group of conditions that affect control of movement and posture. Cerebral refers to the brain and palsy to muscle weakness/poor control. Because of damage to one or more parts of the brain that control movement and posture, an affected child cannot move his or her muscles normally. Thus, these disorders are not caused by problems in the muscles or nerves. Instead, faulty development or damage to motor areas in the brain disrupt its ability to adequately control movement and posture. Depending on which areas of the brain have been dam-
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aged, one or more of the following may occur: muscle tightness or spasticity (increased muscular tone with exaggeration of the reflexes); involuntary movement; disturbance in gait (manner of walking) or mobility; difficulty in swallowing; and problems with speech. Many children with cerebral palsy also have other problems that require treatment. These include mental retardation; learning disabilities; seizures; and vision, hearing, and speech problems. Cerebral palsy itself is not progressive (i.e., brain damage does not get worse); however, secondary conditions, such as muscle spasticity, can develop, which may get better over time, get worse, or remain the same. Cerebral palsy is not a communicable disease. Although cerebral palsy is not “curable” in the accepted sense, training and therapy can help improve function. It is estimated that some 764,000 children and adults in the United States manifest one or more of the symptoms of cerebral palsy. This is more people than any other developmental disability, including Down syndrome, epilepsy, and autism. Cerebral palsy usually is not diagnosed until a child is about 2 to 3 years of age. Currently, about 8,000 babies and infants are diagnosed with the condition each year. In addition, some 1,200 to 1,500 preschool-age children are recognized each year to have cerebral palsy. In the 1860s, an English surgeon named William Little wrote the first medical descriptions of a puzzling disorder that affected children in the first years of life, causing stiff, spastic muscles in their legs and, to a lesser degree, in their arms. These children had difficulty grasping objects, crawling, and walking. They did not get better as they grew up nor did they become worse. Their condition, which was called Little’s disease for many years, is now known as spastic diplegia. It is one of several disorders that affect control of movement due to developmental brain injury and are grouped together under the term cerebral palsy. Because it seemed that many of these children were born following premature or complicated deliveries, Little suggested their condition resulted from a lack of oxygen during birth. He proposed this oxygen shortage damaged sensitive brain tissues controlling movement. However, in 1897, the famous psychiatrist Sigmund Freud disagreed. Almost a century later, in the 1980s, scientists analyzed extensive data from a government study of more than 35,000 births and were surprised to discover that such complications ac-
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count for only a fraction of cases—probably less than 10 percent. In most cases of cerebral palsy, no cause of the factors explored could be found. These findings from the National Institute of Neurological Disorders and Stroke (NINDS) perinatal study have profoundly altered medical theories about cerebral palsy and have spurred researchers to explore alternative causes. Cerebral palsy is not a disorder with a single cause. It is a group of disorders with similar problems in control of movement, but probably with a variety of causes. In about 70 percent of cases, cerebral palsy results from events occurring before birth that can disrupt normal development of the brain. An additional 20 percent are diagnosed with congenital cerebral palsy due to a brain injury during the birthing process. Finally, in the United States, about 10 percent of children who have cerebral palsy acquire the disorder after birth. (The figures are higher in underdeveloped countries.) A large number of factors that can injure the developing brain may produce cerebral palsy. Risk factors for cerebral palsy include the following: premature birth; low birth weight; inability of the placenta to provide the developing fetus with oxygen and nutrients; lack of growth factors during intrauterine life; RH or AB-O blood type incompatibility between mother and infant; infection of the mother with German measles or other viral diseases in early pregnancy; bacterial infection of the mother, fetus, or infant that directly or indirectly attacks the infant’s central nervous system; prolonged loss of oxygen during the birthing process; and severe jaundice shortly after birth. There are three major types of cerebral palsy. Some individuals may have symptoms of more than one type. About 70 to 80 percent of affected individuals have spastic cerebral palsy, in which muscles are stiff, making movement difficult. When both legs are affected (spastic diplegia), a child may have difficulty walking because tight muscles in the hips and legs cause legs to turn inward and cross at the knees (scissoring). In other cases, only one side of the body is affected (spastic hemiplegia), often with the arm more severely affected than the leg. Most severe is spastic quadriplegia, in which all four limbs and the trunk are affected, often along with the muscles controlling the mouth and tongue. Children with spastic quadriplegia often have mental retardation and other problems. About 10 to 20 percent of affected individuals have the athetoid or dyskinetic form of cerebral palsy,
which affects the entire body. It is characterized by fluctuations in muscle tone (varying from too tight to too loose) and sometimes is associated with uncontrolled movements (which can be slow and writhing or rapid and jerky). Children often have trouble learning to control their bodies well enough to sit and walk. Because muscles of the face and tongue can be affected, there can also be difficulties with sucking, swallowing, and speech. About 5 to 10 percent of affected individuals have the ataxic form of cerebral palsy, which affects balance and coordination. They may walk with an unsteady gait with feet far apart, and they have difficulty with motions that require precise coordination, such as writing. Cerebral palsy is diagnosed mainly by evaluating how a baby or young child moves. Early signs of cerebral palsy usually appear before 18 months of age, when parents become concerned about their baby’s or toddler’s tardiness in reaching developmental milestones, such as to roll over, sit, crawl, or walk. The doctor will evaluate the child’s muscle tone, which can make them appear floppy. The doctor also may suggest brain imaging tests such as magnetic resonance imaging (MRI), computed tomography (CT) scan, or ultrasound. Treatment and Prevention “Management” is a better word than “treatment.” Management consists of helping the child achieve maximum potential in growth and development. This should be started as early as possible with identification of the very young child who may have a developmental brain disorder. A team of healthcare professionals works with the child and family to identify the child’s needs and create an individualized plan to help the child reach his or her maximum potential. The team is generally coordinated by one healthcare professional and may include pediatricians, physical medicine and rehabilitation physicians, orthopedic surgeons, physical and occupational therapists, ophthalmologists, speech/language pathologists, social workers, and psychologists. In spite of improvements in the care of pregnant women and sick babies, the number of babies with cerebral palsy seems to be increasing. This is due, in part, to the survival of an increasing number of very premature babies, who are at high risk of cerebral palsy.
Cervical Cancer
However, some causes of cerebral palsy have been identified, and cases of cerebral palsy that result from them can often be prevented. Rh disease and congenital rubella syndrome used to be important causes of cerebral palsy. Now Rh disease usually can be prevented when an Rh-negative pregnant woman receives appropriate care. Women can be tested for immunity to rubella before pregnancy and be vaccinated if they are not immune. If a newborn baby has jaundice, this can be treated with phototherapy (light therapy) in the hospital nursery. Routine vaccination of babies (with the Hib vaccine) prevents many cases of meningitis, another cause of brain damage in the early months. Of great importance are optimal wellbeing prior to conception, adequate prenatal care, and protecting infants from accidents or injury. Active national programs of research are being vigorously pursued to prevent cerebral palsy and improve the quality of life for persons with cerebral palsy. SEE ALSO: Developmental Disabilities; Movement Dis-
orders; National Institute of Neurological Disorders and Stroke (NINDS). BIBLIOGRAPHY. M.C. Hermansen, “Perinatal Causes of
Cerebral Palsy,” Clinics in Perinatology (v.33/2, 2006); K.W. Krigger, “Cerebral Palsy: An Overview,” American Family Physician (v.73/1, 2006); T.N. Raju, “Historical Perspectives on the Etiology of Cerebral Palsy,” Clinics in Perinatology (v.33/2, 2006). Barkha Gurbani UCLA School Of Medicine
Cervical Cancer The cervix is the lower part of the uterus, or womb, of females. It connects the uterus to the vagina, with the part closest to the uterus called the endocervix and the part closest to the vagina called the ectocervix. The junction between the endocervix and ectocervix is called the transition zone because the cell type changes from cuboidal glandular cells to flat, squamous cells. This transition zone is important because most cervical cancers arise in this area. Because there are two different cell types in the cervix, the two ma-
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Addressing worldwide disparities in access to healthcare will be an important part of efforts to conquer cervical cancer.
jor forms of cervical cancer are squamous cell carcinoma and adenocarcinoma of the glandular tissue. Squamous cell carcinomas make up about 80 to 90 percent of all cervical cancers, while the remaining 10 to 20 percent is comprised of adenocarcinomas. The process by which cervical cancer develops involves several stages from precancerous changes to cancer. The precancerous changes are often referred to as cervical intraepithelial neoplasia (CIN) or squamous intraepithelial lesion (SIL) because they are confined to the epithelial, or outermost, layer of cells. The gradual precancerous changes that occur in the cells of the cervix caused by human papillomavirus (HPV) can be detected by a Pap test, which is a test where the doctor samples cells from the cervix to look for precancerous changes. If the gynecologist or pathologist notes precancerous changes in the patient’s Pap smear, more frequent Pap smears may be recommended. In higher-risk patients, further examination of the cervix through a colposcope may also be indicated. In patients who are shown to have precancerous lesions on Pap tests, further testing for the DNA of the HPV may also be indicated. This is because patients with low-grade lesions and acute infection with HPV are at higher risk of developing cancer than those who test negative for the virus. Because Pap tests are very sensitive and relatively cheap to perform and because there are effective interventions for patients who have positive Pap smears, Pap tests are considered to be highly effective
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screening tests for cervical cancer. In fact, it has been shown that over 90 percent of all cervical cancers can be detected by Pap smears. The American Cancer Society has issued guidelines recommending periodic Pap tests for females. It is recommended that all women begin getting Pap smears either three years after their first vaginal intercourse or by the age of 21 at the latest. Periodic testing should be performed every one to two years until the age of 30. For women over the age of 30 who have had three consecutive normal Pap tests, testing can be performed once every two to three years. Women with other risk factors should be tested annually. Women over the age of 70 with three or more normal Pap tests or those who have undergone a total hysterectomy with complete removal of the cervix may cease cervical screening. Although Pap tests are highly effective, it is estimated that about 33 percent of women in the United States do not receive them on a regular basis for a number of reasons. There are a number of known risk factors for cervical cancer. One of the greatest risk factors for cervical cancer is infection with HPV. HPV is a very common virus that comes in a variety of strains. Certain types of HPV can cause benign warts of the skin and cervix (e.g., HPV 6 and 11), while a few are known to cause squamous cell carcinoma of both the cervix and anus (e.g., HPV 16, 18, 31, and 33). The two most common strains of HPV that are known to cause cervical cancer are strains 16 and 18 and are known as “high-risk strains.” Most women who become infected with HPV are able to clear the infection, but some women begin to develop atypical changes of the cells of the cervix that can later develop into cancer. For unknown reasons, most HPV infections occur in younger patients and infection becomes much less common beyond the age of 30. Other risk factors are having sex at an early age, having many sexual partners, having a partner who has had many sex partners, and having sex with uncircumcised males. More risk factors for cervical cancer include smoking, infection with human immunodeficiency virus (HIV), a positive family history of cervical cancer, and infection with chlamydia. Risk factors that are currently being investigated include multiple pregnancies, diet, low socioeconomic status, and exposure to diethylstilbestrol (DES) as a fetus.
Many risk factors for cervical cancer are modifiable in that action can be taken to reduce them. For example, the risk of developing smoking-induced cervical cancer can be greatly reduced by quitting smoking and reducing secondhand exposure to tobacco smoke. The risk of developing HPV-induced cervical cancer can also be reduced by adopting certain sexual practices, such as decreasing number of partners and using barrier contraceptive methods. However, barrier methods, such as condoms, are not foolproof ways of preventing infection with HPV. Recently, two different HPV vaccines have been approved for use in the United States and other countries. These include a vaccine against HPV types 6, 11, 16, and 18 called Gardasil® (Merck) and another vaccine against HPV types 16 and 18 called Cervarix® (GlaxoSmithKline). These vaccines are meant to be administered to prevent infection with HPV, not to treat existing infection. Because HPV exposure occurs primarily through sexual contact, these vaccines are recommended in patients who have not yet become sexually active. Development of guidelines surrounding HPV vaccination has been somewhat controversial due to the cost of the vaccine and the questions of when and to whom to administer the vaccine. The vaccines provide the added benefit of reducing risk of genital warts, but are not able to prevent all types of HPV-induced cervical cancer. For this reason, it is important for patients to continue to modify other risky behaviors and also to continue to seek appropriate screening for cervical cancer through periodic Pap tests. The prognosis of patients with cervical cancer depends primarily on extent of the disease at diagnosis. As with many other forms of cancer, the factors that affect prognosis include stage, volume and grade of tumor, histologic type, lymphatic spread, and vascular invasion. Some reports also suggest that adenocarcinoma of the cervix carries a worse prognosis than squamous cell carcinoma of the cervix. Treatment for cervical cancer varies depending on when the disease is diagnosed. For early-stage disease, treatment options include radical hysterectomy with pelvic and periaortic lymphadenectomy, which is removal of the entire uterus and supporting structures and removal of all lymph nodes in the pelvis and near the abdominal aorta as most cervical cancers spread through invasion of the lymphatic system. Other op-
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tions for early-stage disease include radiation therapy and conization, where the affected part of the uterus is cauterized. Another surgical option called radical trachelectomy involves removal of the cervix and parametrial glands, but allows the patient to retain the uterus and ovaries if future childbearing is planned. Some higher-risk patients may also undergo adjuvant chemotherapy. In more advanced cases, treatment options usually involve combined chemotherapy and radiation therapy or radical hysterectomy. In all cases, treatment options are based on extent of disease and the patient’s plans for bearing children and overall psychosocial status. Continued follow-up is currently recommended and usually entails regular clinical evaluations along with imaging tests at the discretion of the doctor and patient. Cervical cancer represents a small fraction of cancer deaths in women, but the prevalence of cervical cancer is much higher in certain socioeconomic groups and in developing countries around the world. Because there are highly effective screening and preventive measures available, the prevention of cervical cancer morbidity and mortality has become a very important public health issue in the United States and worldwide. Addressing disparities in access to these services worldwide will be an important part of the efforts to overcome morbidity from cervical disease. SEE ALSO: Cancer (General); Cancer Chemotherapy; Can-
cer Radiation Therapy; Gynecology; Vaginal Diseases.
BIBLIOGRAPHY. Eileen M. Burd, “Human Papillomavi-
rus and Cervical Cancer,” Clinical Microbiology Reviews (v.16/1, 2003); Timothy P. Canavan and Nipa R. Doshi, “Cervical Cancer,” American Family Physician (March 1, 2000); John Elkas and Robin Farias-Eisner, “Cancer of the Uterine Cervix,” Current Opinions in Obstetrics and Gynecology (v.10/1, 1998). Jennifer Hellawell Cornell University
Cervical Spine The cervical spine is an integral structural unit of the spinal column, responsible for numerous biomechan-
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ical functions and the protection of the spinal cord and the exiting neural elements. However, the cervical spine is susceptible to degeneration, injury, infection, deformity, and tumors as well as being prone to developmental anomalies. Comprehension of the anatomy and function of the cervical spine is imperative for understanding its role and relation to the head and spinal column. The cervical spine is composed of seven vertebral segments that together provide support for the head and protection for the spinal cord, and facilitate various dynamic movements of the neck. The cervical spine is composed of two basic regions: upper (C1C2) and lower cervical spine (C3-C7). All of the cervical vertebrae have numerous ligamentous structures that serve as bands connecting the various bony elements together. In addition, the cervical spine is unique in comparison to the rest of the spine in that it accommodates passage of the vertebral artery, which is a branch of the subclavian artery that proceeds toward the head to join the basilar artery, thereby supplying a portion of the blood supply to the brain. In addition, the cervical spine from C1 to C4 accommodates the passage of nerve roots that give rise to the cervical plexus, whereas the cervical spine from C5 to C7 gives rise to the brachial plexus. These bundles of nerve branches are responsible for innervating various regions of the body. The atlas (C1) is the first cervical vertebra, which articulates with the base of the skull and forms the occipitoatlantal joint. The axis (C2) is the second cervical segment, which articulates directly with the atlas above and the third cervical segment below. The atlas and axis are the only two cervical vertebrae that are not associated with an intervertebral disc. Anatomically and biomechanically, these two cervical segments differ from the rest of the cervical spine. The atlantoaxial joint accounts for approximately 50 percent of rotation (turning of the head left and right) of the cervical spine, whereas the occipitoatlantal joint accommodates the greatest amount of flexion and extension of the head (nodding). However, excessive movements by the occipitoatlantal and atlantoaxial joints are prevented due to their distinct ligamentous structures and unique bony morphology. The lower cervical spine differs considerably from the upper cervical region. More notably, the lower cervical spine has uncovertebral joints and facets
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joints that prevent excessive rotation. The intervertebral disc is an important structure that acts as a shock absorber and is located between each vertebral segment of the lower cervical spine as well as throughout the thoracic and lumbar spine. The intervertebral disc is composed mainly of an inner and outer region, and contributes approximately 20 to 30 percent of the height of the spinal column. The normal spinal canal of the cervical spine exhibits a triangular configuration; however, the sagittal diameter of the spinal canal decreases from the level of the head on downward. As such, the spinal cord occupies less space in the upper cervical spine region, but more space in the lower cervical spine region. SEE ALSO: Neck Disorders and Injuries; Spinal Cord Dis-
eases; Spinal Cord Injuries.
BIBLIOGRAPHY. A.R. Crossman and David Neary, Neuro-
anatomy (Churchill Livingston, 2000); Francis H. Shen and Dino Samartzis, “Basic Anatomy of the Spinal Column,” in M. Miller and J.K. Sekiya, eds., Core Knowledge in Orthopaedics: Sports Medicine (Mosby Elsevier, 2006); Augustus A. White and Manohar M. Panjabi, Clinical Biomechanics of the Spine, 2nd ed. (Lippincott Williams & Wilkins, 1990). Dino Samartzis, D.Sc., M.Sc., Dip. EBHC Harvard University, and Erasmus University Francis H. Shen, M.D. University of Virginia
Chad Chad, called by some the “dead heart of Africa,” is an arid, landlocked country with few natural resources and many troublesome neighbors. Civil war rocked the population almost continuously from 1979 to 1993. It had barely emerged from this period when conflict in the Darfur region of neighboring Sudan and civil war in the Central African Republic began a refugee crisis in which tens of thousands of people fled across the eastern and southern borders. Decades of warfare and endemic poverty have had a deep impact on the health of average Chadians. Chad’s current population is 10 million, with an unknown and fluctuating number of refugees in border
areas. The population is growing at 2.93 percent annually, with a birth rate of 45.73 births per 1,000 citizens, and a death rate of 16.37 per 1,000 citizens. The migration rate is officially 0.11 migrants per 1,000 citizens, but this figure may be skewed by the refugee situation. A staggering 80 percent of Chadians live on less than $1 a day. The economy has been hampered by the history of civil unrest and a lack of infrastructure. Most Chadians are subsistence farmers, with the country’s main exports being commodities such as cotton, sorghum, millet, peanuts, rice, potatoes, and manioc (tapioca). Since 2000, a consortium of foreign investors has been developing the country’s oil resources, estimated at 1 to 2 billion barrels of recoverable crude; the first oil exports left the country in 2004. It is unclear how much oil revenues might help the average citizen in the future. The population is at high risk for any number of waterborne and vectorborne diseases. About 42 percent have access to clean water, and only 9 percent have adequate sanitary facilities. Chad is located within the African Meningitis Belt. Measles, cholera, and hepatitis E outbreaks are common. Malaria is endemic and carries a fatality rate of between 7 and 12 percent. Respiratory diseases are prevalent within the refugee camps and quickly spread to neighboring communities. The AIDS rate stands at about 3.5 percent, with 180,000 people living with the virus and an estimated 11,000 deaths by 2005; 57,000 children under the age of 17 have been orphaned by the disease and 16,000 children under the age of 14 carry the virus. Infant mortality is high, with 120 children per 1,000 dying before the age of 1 and another 208 per 1,000 dying between the ages of 1 and 5. Immunization rates for Chadian children remain poor, with less than 45 percent receiving protection from common illnesses. More than 50 percent of children are at work before the age of 14, and 72 percent marry before the age of 17. Child trafficking is a major problem within Chad, with an unknown number of young people sold into involuntary domestic or sexual slavery. Chad is also a transit point for children being trafficked between Cameroon, Nigeria, the Central African Republic, and other countries. Female genital mutilation is widely practiced in Chad, with 45 percent of women having undergone the procedure in adolescence. The most common is type II (removal of the clitoris and labia), with type III (infibulation, or the removal of the clitoris and labia
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and sewing shut the labial and vaginal area) still in practice near the Sudanese border. The fertility rate is 6.7 births per women. Only 3 percent of Chadian women have access to birth control, and only 14 percent have a trained attendant monitoring deliveries. This has led to a high maternal mortality rate, with 1,100 maternal deaths per 100,000 live births. The Chadian government spends $7 per capita on healthcare. There is a single national hospital for 7.5 million people and four regional hospitals serving 950,000 each, with 64 district hospitals and 911 health centers spread throughout the country. Virtually all of these facilities are inadequately staffed and lack equipment and supplies. The price of medical care and drugs are beyond the reach of most Chadians. In 2004 there were 345 doctors, 2,400 nurses, and 112 midwives working within the medical system. There is a critical lack of specialists, including anesthesiologists. Nongovernmental organizations have taken the lead in providing medical care in refugee camps, but even they cannot begin to meet the needs of all those who need help. SEE ALSO: Healthcare, Africa; Refugee Health; Sudan. BIBLIOGRAPHY. Central Intelligence Agency, “Chad,”
World Factbook, www.cia.gov (cited June 2007); Joint United Nations Programme on HIV/AIDS (UNAIDS), “Chad,” www.unaids.org (cited June 2007); Researchafrica.rti.org, “Sub-Saharan Africa—Chad” researchafrica.rti.org (cited June 2007); United Nations Children’s Fund (UNICEF), “Chad—Statistics,” www.unicef.org (cited June 2007); World Health Organization, “Guide to Statistical Information at WHO,” www.who.int (cited June 2007); World Health Organization, “WHO Global InfoBase,” www.who. int/infobase (cited June 2007). Heather K. Michon Independent Scholar
Chagas Disease Chagas disease, also known as American trypanomyiasis, is the most important parasitic disease of Latin America, affecting 10 to 20 million people or more. Of these, 1 million will die prematurely as a result of the disease. Chagas disease affects mostly impover-
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ished people from Mexico to southern South America. Recent population movements and the chronic asymptomatic nature of the disease mean that there are hundreds of thousands of infected individuals in nonendemic countries. Due to its transmissibility by transfusion, transplantation, and transplacentally, Chagas disease can be spread in nonendemic countries where there is no screening of the blood and organ supply for the disease. Chagas disease is caused by the flagellated protozoan parasite Trypanosoma cruzi. It is transmitted by multiple species of blood-sucking triatomine insects (also known as kissing bugs or reduvid bugs) that interact with humans when they infest thatched homes in poor rural and periurban communities. Chagas disease is a zoonisis (a disease that normally affects animals but may also affect humans) with a variety of animal reservoirs including armadillos, opposums, and domestic animals. When an infected triatomine bug consumes a blood meal from a human, T. cruzi parasites are excreted in the feces. If the feces come in contact with mucous membranes or penetrates skin, then the resulting local infection may cause a chagoma or a pathognomonic unilateral conjunctivitis known as Romana’s sign. A very small number of individuals suffer from fulminant myocarditis or meningoencephalitis; more commonly, acute infection is asymptomatic and unrecognized. The chronic form of Chagas disease surfaces in about one-third of infected individuals between 10 to 40 years after initial infection. Reactivation of T. cruzi can occur much earlier in the setting of human immunodeficiency virus (HIV) coinfection or in transplant patients. During the long latent phase, T. cruzi parasites infect and multiply within cardiac and smooth muscle cells. As such, chronic infection affects primarily the cardiac and gastrointestinal systems. Cardiovascular effects include cardiomegally, cardiac aneurysms, and conduction abnormalities from benign electrocardiogram (ECG) changes to serious arrhythmias. These conditions often lead to progressive heart failure or to sudden cardiac death. Gastrointestinal manifestations are due to inflammation and destruction of the autonomic ganglia in the gastrointestinal tissues leading to megacolon and megaesophagus in the most severe cases. T. cruzi is increasingly being recognized as a heterogenous complex of organisms with variable
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phenotypic, genotypic, and clinical features. For example, gastrointestinal manifestations of chronic Chagas disease are much more common north of the equator because of the type of T. cruzi strains found in those areas. Diagnosis of Chagas disease in the acute phase is accomplished by identifying parasites in peripheral blood. During the chronic phase, there are few parasites in the blood and even blood or aspirate cultures are often negative. Other strategies include xeno diagnosis (examining feces of triatomine bugs that are allowed to have a blood meal on the suspect patient) and serologic tests, which are available but have relatively high false-positive rates. Detection of parasite DNA by polymerase chain reaction (PCR) amplification is the most sensitive, specific, and expensive means of diagnosis. Drug treatment of the acute stage of infection with nifurtimox or benzinidazole may result in the elimination of the parasite from the blood. The treatment the late Chagas disease has traditionally been only symptomatic. More recently, attempted treatment of chronic infection has become more accepted. Trials of long-term treatment with the above agents (60 days or more) have had measured success in chronically infected children and have even proven effective in preventing or retarding cardiac manifestations in adults. As the diagnosis is usually delayed, and treatment is toxic and of variable efficacy, prevention is the key to reducing morbidity and mortality. Programs to control Chagas disease must focus on reducing human–vector contact by eliminating the vector in sites of human habitation. Campaigns involving spraying homes and domestic animal shelters with residual pyrethroid insecticides have been successful in Southern Cone countries, which have been declared free of transmission. Unfortunately, due to the interaction between sylvatic and domestic cycles of the vectors in Andean pact and Central American countries, vector control has been more difficult. Improved housing combined with awareness and avoidance of the triatomine vector are other proven strategies. Continued funding, political will, and technical expertise are key to further success in controlling Chagas disease. SEE ALSO: Healthcare, South America; Parasitic Diseases.
BIBLIOGRAPHY. Centers for Disease Control and Preven-
tion, “Chagas Disease,” www.cdc.gov (cited September 2006); J.H. Maguire, “Chagas Disease—Can We Stop the Deaths? [comment],” New England Journal of Medicine (v.355/8, 2006); A. Prata, “Clinical and Epidemiological Aspects of Chagas Disease,” Lancet Infectious Disease (v.1/2, 2001). Barry Pakes, M.D., M.P.H. University of Toronto
Chekhov, Anton (1860–1904) Anton Chekhov was a Russian doctor who is considered one of his country’s most prominent writers; he was hugely influential in the development of the modern short story and dramatic form. Chekhov was born on January 29, 1860, in a small port town in southern Russia. In 1875, his father’s business failed. The family lost their house and moved to Moscow while Anton, still a schoolboy, stayed behind in Taganrog. He did not rejoin them until he graduated and obtained a scholarship to study medicine at the University of Moscow. He began to earn money during his medical school years by writing comic pieces for local publication, and within a few years, he was publishing more serious works. Throughout his life, Chekhov never abandoned medicine (calling it his “wife”), but was devoted to literature (his “mistress”). The influence of Chekhov’s professional life is found in his well-developed observations of disease, particularly mental illness, and the repeated appearance of the physician figure in his work. His protagonists frequently suffer from symptoms of depression, alcoholism, and a variety of psychiatric disorders Chekhov himself observed. He prided himself on his accurate depiction of health conditions in his work, and credited his medical training with granting him skills of observation that served him well in literature. Chekhov also uses physician characters in his plays and short stories: In his work, they are variously dispassionate, narrow minded, cynical, or observational. Chekhov passed away on July 15, 1904, severely weakened from tuberculosis that first manifested near the end of his medical training in 1884.
Chemokinesis
SEE ALSO: Abse, Dannie (1923–); Da Vinci, Leonardo. BIBLIOGRAPHY. John Coope, Doctor Chekhov: A Study in
Literature and Medicine (Cross Publishing, 1997); Louis Pedrotti, “Chekhov’s Major Plays: A Doctor in the House,” in Jean Pierre Barricelli, ed., Chekhov’s Great Plays: A Critical Anthology (New York University Press, 1981). Constance W. Liu, M.D. Case Western Reserve University
Chemokine Chemokines are a family of small cytokines, which are proteins secreted by cells. The name comes from their ability to induce directed chemotaxis in nearby responsive cells, making them chemotactic cytokines. These proteins are classified according to shared structural characteristics such as their very small size, as well as the presence of four cyzteine residues in conserved locations that form the key to their threedimensional shape. Chemokines are primarily used to guide the migration of cells, as cells are usually attracted by chemokines and follow the signal of increasing chemokine concentration toward areas that have greater chemokine concentrations. With chemokines serving like hormone-like mediators, they have been shown to have the ability of attracting immune system cells to specific sites in the human body. It has been found that chemokines are located in all vertebrates and also in some viruses and bacteria, but have not been found in animal life classified as invertebrates. The discovery of the chemokines and the movement of cells has become extremely useful for medical research, especially with the human immune systems. Chemokines are seen as a method of preventing the spread of infections. Although chemokine research has resulted advances in a number of areas, it is also regarded as potentially rewarding in trying to help with the treatment of human immunodeficiency virus (HIV). This is because the entry of HIV into a host cell requires the participation of some of the cell surface proteins that normally serve as chemokine receptors. HIV infects helper T-cells
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by using a protein called gp120, and is embedded in its envelope. This leads to the gp120 protein binding itself to a molecule called CD4, which is found on the surface of the helper T-cell. This in turn leads to a large number of reactions that then allow the HIV genetic information to enter the cell. As a result, one of the areas of research into HIV has been into the binding of gp120 to CD4, which in turn exposes a region of gp120 that interacts with the chemokine receptors. Some researchers believe that looking into changes in the chemokine receptors may help find a way to treat HIV. SEE ALSO: AIDS; Chemokinesis; Cytokine. BIBLIOGRAPHY. E. Fernandez and E. Lolis, “Structure,
Function and Inhibition of Chemokines,” Annual Review of Pharmacological Toxicology (v.42, 2002); K. Laing and C. Secombes, “Chemokines,” Developmental and Comparative Immunology (v.28/5, 2004); Craig Mudroch and Adam Finn, “Chemokine Receptors and Their Role in Inflammation and Infectious Disease,” Blood: Journal of the American Society of Hematology (v.95/10, 2000); Richard Ransohoff, et al., eds., Universes in Delicate Balance: Chemokines and the Nervous System (Elsevier, 2002). Justin Corfield Geelong Grammar School, Australia
Chemokinesis Chemokinesis is the motile response of unicellular prokaryotic or eukaryotic organisms to chemicals which cause the cell to make some changes in their migratory behavior, usually involving a change in its movement, by speeding it up, slowing it down, or changing its direction. It gets its name from chemokines which in turn take their name from chemotactic cytokines—the term chemo being used to describe any condition where there is an increase in the activity induced by the presence of any chemical substance. In chemokinesis the changes involve a decrease or an increase in speed, alterations of amplitude or frequency of motile character, or changes in the director of migration. Chemokinesis, in contrast with
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chemotaxis, involves a random and non-vectorial moiety. However there have been variations with chemoattraction not necessarily including any element of orientation for the cells themselves. This use of Chemokinesis has proved important in research into the human coronary system and also into helping locate effective receptors for treatment for a variety of conditions. See also: Chemokine; Coronary Disease. Bibliography. G. J. Ferguson, et al., “���������������� PI(3)Kgamma has
an Important Context-Dependent Role in Neutrophil Chemokinesis,” Nature Cell Biology (v.9/1, 2007); A. L. Gonzalez, et al., “Transendothelial Migration Enhances Integrin-Dependent Human Neutrophil Chemokinesis,” Journal of Leukocyte Biology (v.81/3, 2007); T. ������������� Okada and J.G. Cyster, “������������������������������������������ CC Chemokine Receptor 7 Contributes to GiDependent T Cell Motility in the Lymph Node,” Journal of Immunology (v.178/5, 2007). Justin Corfield Geelong Grammar School
Chemoprevention Chemoprevention is the use of drugs, vitamins or other chemical agents to try to reduce the risk of developing cancer, to delay development of cancer or to reduce recurrence of cancer. The National Cancer Institute established a program in the 1980s to evaluate possible effectiveness of many compounds both natural and synthetic. The first compound to show effectiveness was tamoxifen (a synthetic compound used in treating breast cancer) in patients with risk for breast cancer. In 1988, the Food and Drug Administration (FDA) approved the use of tamoxifen as a preventive against breast cancer in high risk patients. Chemoprevention as an approach to preventing cancer is receiving attention both in clinical research and medical practice as a way of limiting the negative medical and financial implications of diagnosing and treating cancer. As many people have embraced lifestyle changes with nutrition, exercise and other life changes for disease prevention, che-
moprevention provides an additional measure to be used for overall health in those populations at risk for cancer (previous cancer patients, pre-cancerous conditions, higher risk from family history, lifestyle, occupation and environment) as well as the general population. Research studies on prevention of cancer provide additional treatment options for those patients who have already been diagnosed and treated for cancer to prevent recurrence. This has shown to be effective in the treatment of breast cancer in reducing rates of recurrence over a five year period with increased survival rates. In addition, newer recombinant vaccine therapy is providing new ways of looking at cancer treatment before it occurs to achieve the best possible results for normal longevity. Chemoprevention Currently Approved for Use Tamoxifen. Tamoxifen, a selective estrogen receptor modulator used to treat breast cancer has shown a protective effect after the patient stopped taking the medication. Research from the United Kingdom shows women at high risk for breast cancer continue to receive a risk-reduction benefit from tamoxifen supporting the U.S. Breast Cancer Prevention Trial which found a continued benefit from tamoxifen after its use had ended and a stronger benefit-to-risk ratio in premenopausal women. Because of side effects and the potential for the development of endometrial cancer, tamoxifen may not be the best choice for cancer prevention. Other selective estrogen receptor modulators like raloxifine are showing the same chemopreventive effects with a reduced risk and even protective effect against endometrial cancer. Human Papillomavirus (HPV) Vaccine. Human Papillomavirus (HPV) Vaccine was approved for use in the United States, Canada, and the European Union in 2006. The recombinant vaccine marketed under the names Gardisil, and Silgard, is used as prophylaxis against diseases (including prevention of cervical cancer) caused by four types of HPV. The vaccine is given in three doses (initial dose, second dose in two months from initial dose, and third dose in six months from initial dose). Clinical study data shows 100 percent effective in preventing cervical precancers and non-invasive cervical cancers related
to HPV 16 and HPV 18 types, 95 percent effective in preventing adenocarcinoma in situ, and 100 percent effective in preventing vulvar and vaginal pre-cancers related to HPV 16 and HPV 18. Medications with Potential Effectiveness in Cancer Prevention Finasateride, an enzyme inhibitor used to treat benign prostatic hyperplasia (BPH) was shown in a study by the Prostate Cancer Prevention Trial showed a 25 percent reduction of prostate cancer, though the long-term survival portion of the study has not been completed. Retinoic acid derivatives produce remission in patients with acute promyelocytic leukemia and as a chemopreventive agent for secondary tumor growth in patients with head and neck squamous cell carcinoma. Retinoic acid derivatives are believed to regulate cell growth, differentiation, and programmed cell death. Aspirin and other nonsteroidal antiinflammatory drugs (NSAIDS), medications used for pain relief, fever reduction and to treat arthritis (aspirin, sulindac, piroxicam, and celecoxib have show reduction of risk for colorectal cancer. However, although aspirin has shown to also be protective for cardiovascular events, other NSAIDS have shown an increased risk for cardiovascular events. Beta carotene and vitamin E are carotenoids that protect plants from cell damage and are used in human biochemical process. However, as a chemopreventive medication results have not shown a reduction in the incidence of cancer either for prostate cancer or for preventing the occurrence of second primary tumors in patients treated with radiation therapy for head and neck cancer. The ongoing selenium and Vitamin E Cancer Prevention Trial (SELECT), for instance, will follow more than 35,000 men for at least seven years to help determine whether vitamin E and selenium can protect men against prostate cancer. Selenium is also being studied for chemopreventive benefits against lung cancer; however, a study from Warwick Medical School, in Coventry, U.K., has shown selenium may increase the risk of developing type 2 diabetes. According to studies presented at the 2005 American Society of Clinical Oncology annual meeting, some existing medications may take on a role in the prevention of the onset of prostate, endometrial,
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and breast cancers. Toremifene, a selective estrogen receptor modulator used to treat breast cancer reduces the risk of developing prostate cancer. A preliminary study at Regional Urology LLC, in Shreveport, Louisiana, of 514 men with a precancerous condition prostatic intraepithelial neoplasia received 20 milligrams, 40 milligrams, or 60 milligrams of toremifene or a placebo. At the end of one year, 31.2 percent of the men in the placebo group had developed prostate cancer, versus only 24.4 percent in the 20-milligram group. Raloxifene, a selective estrogen receptor modulator used to treat breast cancer has shown a protective effect against endometrial (uterine lining) cancer. Statins, cholesterol-lowering drugs may reduce breast cancer risk although human clinical research shows conflicting data. One study of 40,000 female veterans showed women who took statins had an associated decreased risk for breast cancer. Chemoprevention Trials Chemoprevention trials are research studies conducted on healthy participants to study the effects of drugs, vitamins or other chemical agents on cancer prevention. Instead of using tumor formation as the end point, researchers use biomarkers or tumor markers to determine efficacy. Biomarkers include cervical dysplasia, colon crypt formation and polyps or tumor markers include genetic specific and non-specific indicators of the presence of cancer like CA-125, and chromosomal gene mutations like P-53. Research is ongoing to determine cancer preventive effects of oltipraz a dual antiparasitic/anticarcinogenic agent against bladder cancer, difouromethylorithine (DFMO) a synthetic enzyme inhibitor against bladder, breast, cervical, colorectal, prostate, and skin cancers. In addition, calcium, flavonoids, antioxidants (vitamins A, C, E, lycopene, etc.) are being researched against bladder, breast, cervical, colorectal, head and neck, lung, prostate, and skin cancers. Herbal Medicine In most cases, the use of herbal medicine to prevent cancer is based on observation, animal studies and laboratory cell studies. Clinical studies in humans are needed to confirm cancer preventive benefits. Herbal medicines should be considered as drugs and caution
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used in taking them as supplements because of possible interactions with prescription medications, lack of standardization in extract formulas and minimal empiric scientific evidence to confirm claims of cancer preventive activity. Grape Seed Extract. Grape seed contains antioxidant substances that prevent cell damage caused by free radicals, which are highly reactive molecules that can damage cell function. Grape seed extract has been used for cancer prevention and wound healing. Although grape seed extracts have shown some beneficial antioxidant effects in preliminary clinical trials, few trials have looked at specific diseases or conditions. One study funded by the National Cancer Institute (NCI) found that grape seed extract did not reduce the hardening of breast tissue that can occur after radiation therapy for breast cancer and NCI is funding additional studies to evaluate grape seed extract for the prevention of breast and prostate cancers. Green Tea. All types of tea (green, black, and oolong) are produced from the Camellia sinensis plant using different methods. Fresh leaves from the Camellia sinensis plant are steamed to produce green tea. Green tea and green tea extracts, such as its component EGCG, have been used to prevent and treat a variety of cancers, including breast, stomach, and skin cancers. Green tea is usually brewed and drunk as a beverage. Green tea extracts can be taken in capsules and are sometimes used in skin products. Laboratory studies suggest that green tea may help protect against or slow the growth of certain cancers, but studies in people have shown mixed results. Green tea is safe for most adults when used in moderate amounts though it may cause interactions with some prescription medications. Garlic. Garlic been used as both a medicine and a spice for thousands of years, some research studies provide evidence that garlic and its components are effective inhibitors of the cancer process by slowing or preventing tumor cell growth. A study conducted at the School of Chinese Medicine also shows that a crude extract of garlic induces a caspase -3 gene expression that leads to apoptosis (cell death) of human colon cancer cells. Research thus far on garlic has been performed in animal models or cell cultures and epidemiology observation of populations comparing garlic consumption with no garlic consumption.
Clinical trial in humans is necessary to verify garlic’s cancer preventive possibility. Lycopene. Lycopene, shown to have antioxidant and antiproliferative properties in animal and cell studies and is present in the human body in higher levels than other carotenoids. Human clinical studies have not shown reduced incidence of cancer corresponding to the observational or epidemiology studies have shown certain populations have lower incidence of cancer correlated with the consumption of lycopene. One of the potential problems is the difference in dosing between intake of lycopene by the use of tomato based products compared to the use of lycopene supplements. Studies have examined large populations to identify which lifestyle factors affect health. Panax Ginseng. Ginsan, an acidic polysaccharide isolated from Panax ginseng activated multiple effector pathways of the immune system with increased proliferation of T-cells and B-cells and induced spleen cells to become cytotoxic against a wide range of tumor cells in mice, with no harm to the mice. This study indicates potential for the use of ginsan to activate the immune system and provide a nontoxic anti-neoplastic medication. Probiotics. Probiotics are live microorganisms, which, when administered in adequate amounts, confer a health benefit on the host as defined by the United Nations Food and Agricultural Organization and the World Health Organization. Foods containing probiotics are yogurt, fermented and unfermented milk, miso, tempeh, and some juices and soy beverages. Most often, the microorganisms come from the bacteria, Lactobacillus or Bifidobacterium. Although studies are limited, there is some evidence from study of specific probiotic formulations regarding a reduction in the recurrence of bladder cancer. Red Wine. Red wine is a rich source of biologically active phytochemicals, in particular two components of red wine (catechins and resveratrol) are believed to have anticancer properties. These compounds are antioxidants that protect cells from destruction by free radicals. Resveratrol has been shown to reduce tumor incidence in animals by affecting one or more stages of cancer development and inhibit cancer cell growth in cell cultures. The cell and animal studies of red wine have examined effects in several cancers including leukemia, skin, breast, and prostate cancers.
Scientists are studying resveratrol to learn more about its cancer preventive activities. Recent evidence from animal studies suggests this anti-inflammatory compound may be an effective chemopreventive agent in three stages of the cancer process: initiation, promotion, and progression. Research studies have linked drinking a glass of red wine a day and decreased risk of prostate cancer, even against more invasive disease. However, even though many different supplements made of resveratrol are available, human clinical studies are being conducted with red wine; no scientific evidence has shown definitively that resveratrol is an effective chemopreventive substance. Saw Palmetto. A double-blind, randomized study conducted at the University of California, San Francisco, showed no difference in improving the symptoms of benign prostatic hyperplasia compared to placebo. Over-the-counter use of saw palmetto products to treat the condition is common in older men based on previous clinical studies showing positive benefits. Though the University of California researchers indicate their research corrected for flaws in earlier studies by following the 225 men over age 49 for a full year, using a consistent herbal product, however the research study was designed to correct some of the design flaws seen in earlier studies, they suggest a different preparation or dose of saw palmetto might have been effective.
See also: Breast Cancer; Cancer Alternative Therapy; Cancer (General); Cervical Cancer; Herbal Medicine; Immunotherapy; Prostate Cancer; Prostate Diseases. BIBLIOGRAPHY. “Cancer Prevention,” www.cancer.gov
(cited August 2007); “Garlic,” “Grape Seed,” “Probiotics,” and “Green Tea,” nccam.nih.gov (cited August 2007); “HPV Vaccine for the Prevention of Cervical Cancer and Other Diseases in EU,” ctep.info.nih.gov (cited August 2007); Hope S. Rugo, “Cancer,” in Current Medical Diagnosis & Treatment 2004 (Lange, 2004); Sydney E. Salmon, and Alan C. Sartorelli, “Cancer Chemotherapy” Basic and Clinical Pharmacology (Appleton and Lange, 1998); Peter Teeley and Philip Bashe, The Complete Cancer Survival Guide (Doubleday, 2000); “Saw Palmetto Fails to Improve Benign Prostatic Hyperplasia,” “Celecoxib Significantly Reduces the Risk of Precancerous Colorectal Polyps,” “Studies Affirm Tamoxifen’s Long-Term Preven-
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tive Benefit,” “Red Wine and Cancer Prevention,” “Vitamin E Does Not Help Head and Neck Cancer Patients,” www.cancer.gov/clinical trials (cited August 2007). Lyn Michaud Independent Scholar
Chemoradiotherapy The major modalities for the treatment of cancer patients are surgery, radiotherapy, and chemotherapy, all of which aim to eliminate all cancer cells. Chemoradiotherapy is the combination of chemotherapy and radiation therapy administered to cancer patients. Adjuvant chemotherapy refers to the application of chemotherapy after radiation or surgery to control micrometastatic tumor and to try to increase the cure rate for breast and colorectal cancer. Neoadjuvant chemotherapy, on the other hand, is the use of chemotherapeutic agents prior to radiotherapy or surgery, causing initial shrinkage of tumors. The first clinical use of chemotherapy was documented in the early 1940s when the use of nitrogen mustard obtained a brief remission in a patient with lymphoma. Since then, many different types of drugs or biological agents that are cytotoxic (cell killing), hormonal, monoclonal antibodies, or small molecules have been developed to treat cancer patients either as single drugs or in combination with others. The goal of these drugs is to kill cells. Ideally, the chemotherapeutic agents would target and eradicate only growing tumor cells, but in reality, healthy cells are often killed, which leads to side effects such as hair loss and vomiting. The efficacy of chemotherapy is sometimes hindered when tumor cells become resistant to the chemotherapeutic agents due to cellular mechanisms such as decreased uptake and increased efflux of drugs. Radiation therapy refers to cancer treatment using ionization radiation such as X-rays or gamma (γ) rays that can be delivered by various methods such as external beam radiotherapy with a linear accelerator. Brachytherapy is another type of clinical radiotherapy that gives powerful localized radiation doses from wires or seeds containing radioisotopes that give out radioactive decay while being implanted within an
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organ or tissue. Radiotherapy can provide high curative rates in cancers such as Hodgkin’s disease and testicular cancer. While being absorbed by the cells, radiation causes random injury to the DNA. Efficacy is determined by the extent of cellular damage that is beyond repair. In general, cell killing is achieved when the normal cells are more effective in repairing themselves, causing more death in the cancer cell population. The dose of radiation is quantified as the amount of energy absorbed per unit mass and the standard unit is the gray (Gy), which is defined as one joule per kilogram. When delivered to a tumor, the dose of radiation is limited to the damage to the surrounding healthy cells. It is also dependent on several factors such as the goal of the therapy (curative versus palliative), relative sensitivity of the specific cancer cells to radiation, the volume of cancer, and condition of the patient. SEE ALSO: Breast Cancer; Cancer (General); Cancer Che-
motherapy; Chemotherapy; Colorectal Cancer; Nausea and Vomiting; Oncology. BIBLIOGRAPHY. Mark H. Beers, Robert S. Porter, and
Thomas V. Jones, eds., The Merck Manual of Diagnosis and Therapy, 18th ed. (Merck Research Laboratories, 2006); Raymond E. Lenhard Jr., Robert T. Osteen, and Ted Gansler, eds., Clinical Oncology (American Cancer Society, 2001); Ian F. Tannock, et al., eds., The Basic Science of Oncology, 4th ed. (McGraw-Hill, 2005). Stephen Chen University of Toronto
Chemotherapy Chemotherapy is the treatment of disease by administering drugs. Chemotherapy is most commonly used to treat all types of cancer by destroying cancer cells and preventing them from metastasizing. During chemotherapy, chemicals are introduced into the body to destroy cancerous cells and tumors, and these chemicals also spread throughout the body, destroying malignant cells that have spread to other organs. Chemotherapy works well, but it also affects normal cells, causing undesirable side effects.
Chemotherapy is administered in highly variable periods of treatments, giving the body ample time to recover and rest.
Chemotherapy disrupts the cell cycle, which is the process by which cells reproduce, grow, and perform their daily functions. If the cell cycle is disrupted, the cell dies. Chemotherapy drugs may disrupt a specific phase of the cell cycle, usually the DNA replication phase. This means that chemotherapy drugs also disrupt cell cycles in normal body cells such as in the bone marrow, the mouth, and the digestive track, causing unpleasant side effects such as hair loss, mouth sores, vomiting and nausea, and a weakened immune system if drugs affect the bone marrow. Extra medication is taken to counter these side effects. The countermedications help restore the normal functioning of the stomach and prevent nausea and vomiting. White blood cell count is also carefully monitored by physicians administering chemotherapy drugs to patients.
Different types of chemotherapy drugs exist to treat various types of cancers and tumors, and they affect these cells in different phases of the growth cycle. For example, alkylating drugs disrupt cells in all phases of the cell cycle and are commonly used to treat lymphatic cancers, skin cancers, and other malignancies. Alkylating drugs work by adding alkyl groups to electronegative regions of all cells, causing adjacent guanine bases in DNA to attach to each other and disrupting DNA replication in the S phase of the cell cycle. An example of an alkylating drug is cyclophosphamide, which also attacks the immune system. Other types of alkylating drugs include nitrosoureas, which inhibit the DNA repair phase. Nitrosoureas can also flow through the blood-brain barrier and are used in the treatment of brain malignancies. Common nitrosoureas are carmustine (BCNU), semustine, and lomustine (CCNU). Other types of chemotherapy drugs are antimetabolites, which mimic DNA substrates. This causes the incorrect substrate (an antimetabolite) to be inserted into a growing DNA strand, creating abnormal DNA. An example of antimetabolites is flucytosine. Mitotic inhibitors, another type of chemotherapy drug, work by attaching to a protein called tubulin, thus preventing cell division. Finally, there are drugs that change the levels of sex hormones produced in the body. For example, estrogen is needed by some ovarian and breast cancers to grow. These drugs lower the level of body estrogen, thus preventing the spread of cancer. Chemotherapy drugs are most commonly administered using combination therapy. During combination therapy, two different drugs are prescribed at the same time in smaller doses, thus reducing the occurrence of side effects. The two drugs work effectively by attacking cells in different phases of growth, making the attack more powerful and effective. Combination therapy also reduces the risk of developing resistance to chemotherapy drugs, which can develop with prolonged use of a particular drug. Chemotherapy also works in combination with surgery and radiation therapy. Chemotherapy drugs may increase the effectiveness of radiation therapy, thus reducing the dosage of radiation needed for treatment. Surgery may also make chemotherapy drugs more effective. Tumors may be surgically removed and then drugs may be administered in lower dosages to attack only the area surrounding where the tumor had been.
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Drugs may be administered in the form of a pill or injected into the body using a needle. Chemotherapy is administered in highly variable periods of treatments, giving the body ample time to recover and rest. Some patients may be given daily treatments, some once a month, and others once every three weeks. Chemotherapy is not always successful—not even in combination with radiation therapy and surgery. Some cancers and tumors of the brain, pancreas, and prostate do not respond to these chemical treatments. Doctors have come up with new compounds that locate cancer cells and shut them down while allowing healthy cells to function normally. An example of such a drug is Gleevec®, used for treating chronic myelogenous leukemia. Further research is being conducted in the field of biomedical engineering, where miniature machines pinpoint malignant cells and perform microsurgery—safely removing all infected cells without damaging normal cells and without side effects. SEE ALSO: Cancer (General); Cancer Chemotherapy; Can-
cer Radiation Therapy; Chemoradiotherapy.
BIBLIOGRAPHY. Joseph T. Dipiro, et al., Pharmacotherapy:
A Pathophysiologic Approach (McGraw-Hill, 2005); Laurence Brunton, John Lazo, and Keith Parker, Goodman & Gilman’s The Pharmacological Basis of Therapeutics (McGraw-Hill, 2005).
Rahul Gladwin, M.D. University of Health Sciences Antigua
Chen, Zhong Wei (1929–2004) Zhong Wei Chen was a Chinese microsurgeon and orthopedic surgeon who became a leader in his field when he became the first to perform and publish a report of a hand reattachment in 1963. After this successful operation, Chen developed many other microsurgery procedures while working at the Sixth People’s Hospital in Shanghai, China. Chen was born in Ningbo, Zhejiang Province, China, in 1929, the son of a doctor and a pharmacist. In 1948, he entered the Shanghai Second Medical College, where he developed his interest in surgery. He enrolled in postgraduate training in 1954 at
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Shanghai Lister Hospital. His mentor was Professor Yan Qing Ye, one of the founders of modern Chinese orthopedics. Afterward, Chen moved to Shanghai Sixth People’s Hospital, where he quickly became an internationally renowned microsurgeon. The operation that earned him the title of “Father of Replantation” was performed in 1963 on a Chinese factory worker whose right hand had been severed an inch above the wrist. Chen was the first to report a case of extremity replantation in medical literature in the Chinese Medical Journal. After the hand reattachment, Chen continued to develop the field of microsurgery, carrying out, together with his team, 1,100 digit and limb replants by 1983. These included an arm replantation after segmental resection, a case that opened new frontiers in functional restoration after tumor removal. Chen also successfully reconstructed forearm muscles and was among the first to reconstruct a missing thumb with a second toe. As the head of his microsurgery laboratory, he encouraged research in methods to improve the patency of small vessels, preservation of amputated extremities, and vascularized nerve grafting. These operations and research contributed to the international dimension of his reputation; during his career, Chen was invited to lecture in 40 universities around the world. He published many papers in medical journals and was honored with many scientific awards such as the presidency �������������������������������� of the International Society for Reconstructive Microsurgery and the Chinese Qiu Shen Award for the top 10 Chinese scientists in history.������������������������������������������ When he died on March 23, 2004, in Shanghai, from falling off the balcony of his seventh-floor apartment, Chen was the chairman of the Department of Surgery at Zhong Shan Hospital in Shanghai. He was also a member of the Chinese Academy of Sciences and a founding member of the International Society for Reconstructive Microsurgery. SEE also: Microsurgery; Surgery. BIBLIOGRAPHY. B. Strauch, Han-Liang Yu, and Zhong-
Wei Chen, Atlas of Microvascular Surgery (Thieme Publishing Group, 1992); Caroline Richmond, “Zhong Wei Chen. Obituary,” British Medical Journal (v.328, 2004). Luca Prono Independent Scholar
Chickenpox The varicella zoster virus is a member of the herpes virus family. Varicella zoster virus causes the infectious disease known by the common name chickenpox. The virus passes from person to person through contact transmission with an incubation period of 10 to 20 days from exposure. Physicians usually make a clinical diagnosis of chickenpox; the infected person shows signs such as fever or lesions and might complain of loss of appetite, malaise, or pain. Chickenpox can be confirmed with laboratory tests for varicella zoster virus including enzyme-linked immunosorbent assay (ELISA), which uses specific antibodies to identify the corresponding antigen, fluorescent antibody (a reaction combining fluorescing dyes attached to antibodies that glow when attached to the complementary antigen in the serum), and hemagglutination reaction where antigens and antibodies combine to form a clump. Most children who develop chickenpox experience a fairly benign form. They may develop a low-grade fever and malaise. Raised red lesions form a rash on the trunk, neck, and face. During this time, a physician might recommend a lotion like calamine or antihistamines to relieve the itching. While the lesions are forming and rupturing, the varicella zoster virus is highly contagious to those persons who have never had the virus. The infected person may continue to develop new lesions from one to five days after the first breakout. The lesions crust over and fall off in approximately 14 days from eruption. Although infrequent, severe complications of the illness may include Reye’s syndrome with concomitant aspirin therapy, pneumonia, bacterial superinfection, or encephalitis. Infected adults often experience more severe symptoms and are at a higher potential risk for additional adverse effects. Women in the first trimester of pregnancy appear to be more prone to the development of pneumonia requiring intravenous antiviral treatment and respiratory support. Infection with varicella zoster virus during the second and third trimesters is less life threatening. The antibodies cross the placenta providing protection to the fetus. To protect immunocompromised individuals and pregnant women, varicella zoster immune globulin can be administered. Varicella zoster immune globulin contains the antibodies for the virus and will pro-
Child Abuse
vide temporary and immediate passive immunity for susceptible individuals within four days of exposure. Varicella zoster immune globulin can also be given to premature infants and newborns when the mothers give birth during active chickenpox infection and before antibodies have formed in the mother’s blood. A test for confirmation of the virus can be performed on umbilical cord blood. Becoming ill with a disease and recovering results in lifelong immunity from having it again. This type of immunity is called acquired immunity. The body adds antibodies to the specific antigen to its arsenal for fighting off disease. While a person cannot have chickenpox again, the virus becomes latent, ascending to the dorsal root ganglia to hide from the immune system and the antibodies now present in the body to combat infection. Varicella zoster virus has two different life cycles: a productive or active phase and a latent phase. The productive phase occurs in skin cells, where the virus can grow and multiply. This is also the infectious phase of the virus. The latent phase occurs in nerve cells. The latent virus may go through periodic reactivation. A person may live for months or years without an outbreak. An undefined trigger or immuno compromised state causes the growth of the varicella zoster virus inside the nerve cell. These new viruses travel down the nerve fiber and infect the skin. The rash will be localized on the surface of the skin supplied by that nerve cell. This form of the disease is known as shingles and can be very painful. As with chickenpox, the blisters that form will be contagious to persons who have not had chickenpox or been vaccinated with varicella zoster virus vaccine. Up until the mid-1990s chickenpox was considered a common childhood illness and many children were exposed to the varicella zoster virus at school or camp. Vaccine researchers used the antibodies from children who had chickenpox. The virus passed through a variety of steps including culturing in guinea pig and human cells to attenuate the virus, weakening it enough to not cause the disease yet provide enough of the pathogen for the body to develop antibodies. The vaccine provides active immunity to the disease by stimulating the formation of antibodies. If the virus invades again, the body’s defenses will include an artificially induced memory of having the disease and being able to combat it.
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Current guidelines recommend the administration of varicella zoster virus vaccine to children aged 12–18 months and to children 11–12 years old who have not previously received the vaccination nor had chickenpox. Because of the risk of Reye’s syndrome, parents are cautioned to not give Aspirin for at least six weeks after receiving the vaccine. Health professionals encourage early childhood vaccination according to established guidelines. As a public health issue physicians discuss the risks and benefits of vaccination. Vaccination against varicella zoster virus protects children from contracting chickenpox and provides a level of protection to those individuals in the public who are not immunized, because the virus is contagious only during active skin infection. See also: Acquired Immunity; Active Immunity; Child-
hood Immunization; Immunization/Vaccination; Shingles (Herpes Zoster); Smallpox; Viral Infections. BIBLIOGRAPHY. John M. Beale Jr., “Fundamentals of Im-
munology and Immunizing Biologicals,” Textbook of Organic Medicinal and Pharmaceutical Chemistry, 10th ed. (Lippincott-Raven, 1998); Dorothy H. Crawford, The Invisible Enemy: A Natural History of Viruses (Oxford University Press, 2000); Samuel Shelburne III and Wayne X. Shandera, “Infectious Diseases: Viral and Rickettsial,” Current Medical Diagnosis and Treatment (Lange Medical Books, 2004). Lyn Michaud Independent Scholar
Child Abuse The term child abuse encompasses many behaviors that adults perpetrate against children, including physical harm, sexual contact, emotional maltreatment, and material neglect of a child’s physical, emotional, or medical needs. Those committing abusive acts can include not only the child’s biological parents or legal guardians, but also caretakers, teachers, grandparents, members of the clergy, friends of the family, and other adults who have contact with the child. The effects of abuse on child health, growth, and development can include death, long-term physical injury, and psychiatric symptoms, such as depression and low self-esteem,
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that persist into adulthood, and often lead to suicidal thoughts, substance abuse, and perpetuating the cycle of violence on one’s own children. A range of acts can constitute physical child maltreatment, including attacking the child with an object; dunking the child into boiling water or otherwise causing burns, pushing, kicking, or slapping the child; physically confining a child with rope or other restraints; or attacking the child with a knife, razor blade, or other conventional weapon. One complication in detecting physical maltreatment is that corporal punishment of children is still legal and somewhat common in several countries, including the United States. This acceptance of corporal punishment often leads to confusion on the part of parents and other potential child abuse perpetrators as to where the line between acceptable physical force and abuse falls. Symptoms of physical child abuse can include fractures, burns, bruises, missing teeth, internal bleeding, and abrasions on the skin. While not all injuries to children are the result of child abuse, abused children often exhibit characteristic patterns of injuries, such as clustered bruises, torsional arm fractures, cigarette-sized burns, or other injuries not easily explainable in the context of a child’s normal activities and developmental stage. One particularly common form of physical child abuse prevalent in infants under the age of one is shaken baby syndrome, which occurs when an individual violently shakes an infant, causing internal injuries resulting from gravitational acceleration and deceleration. One feature of shaken baby syndrome is that there is very little external evidence of abuse unless the infant’s head strikes a wall or other object, but internally, the infant can suffer from retinal hemorrhages, subdural hematomas, and fracturing of the ribs or long bones. Shaken baby syndrome is a common cause of infant mortality, and even nonfatal injuries can be quite severe, and include blindness, cerebral palsy, and cognitive impairment. Clinicians should strongly suspect shaken baby syndrome or other physical abuse when an infant presents with injuries that are not explained by the normal milestones of development in infants. Sexual abuse of children includes not only sexual intercourse or assault, but also fondling of a child’s genitalia or breasts, masturbating in the presence of a clothed or unclothed child, inappropriate exposure of genitalia to a child, or forcing the child into unwanted
Abuse can lead to long-term physical injury and psychiatric symptoms, such as low self-esteem, that persist into adulthood.
sexual acts. Exploiting children for the production of pornographic films or for prostitution also constitutes sexual abuse. While not always easy to detect, research has indicated that children who have been sexually abused will often have nightmares, exhibit regressive behaviors such as bedwetting, sexual behavior inappropriate to the age of the child, pregnancy in young adolescents, or genitourinary symptoms of trauma or a sexually transmitted infection. Emotional abuse of children can take the form of rejecting the child emotionally or physically abandoning the child; unduly criticizing the child or blaming him or her for family misfortune; threatening the child with death, mutilation, or punishment; isolating the child from peers or other family members; encouraging the child to participate in criminal activities such as drug selling; or abusing favorite pets. Symptoms of emotional abuse include depression, anxiety, stomach or head pain without any other cause, failure to gain weight (especially in infants), difficulty forming rela-
tionships, inappropriate emotional reactions such as angry outbursts or cruelty toward others, and withdrawing from social contact with others. A rare but often harmful form of child abuse is Munchausen-by-proxy, whereby a parent instigates the diagnosis and treatment of injury or illness in a child that either does not have these conditions, or whose medical conditions were inflicted by the parent. The goal of Munchausen parents is purported to be vicarious attention and sympathy for the medical hardships of the child, which can include hospitalization, unnecessary operations and medications, and even death. Because these parents seem so attuned to the medical concerns of their children, this syndrome can be hard to detect. Neglect of children can take the form of failure to provide adequate food, shelter, clothing, hygiene, protection from injury, or medical care. Neglect can also take the form of educational neglect, whereby parents fail to provide children with schooling as required by the state. However, detecting the neglect of children is often confounded by both poverty and shifting standards, across time and locale, of what level of provision is adequate for a developing child. Rather than discrete episodes, as is often the case with physical or sexual abuse, childhood neglect is usually characterized by ongoing inadequate attention to the child’s needs. Neglected children often fail to grow appropriately or suffer from malnutrition; exhibit long-term medical problems such as uncontrolled asthma or diabetes; and can also exhibit behavioral and psychiatric symptoms including depression, substance abuse, and difficulty forming long-term relationships. In many countries, the legal and medical systems often interface as medical providers are often the first adults outside the immediate family to recognize and report child maltreatment. Medical providers are often also called on to provide professional evaluations and testimony as to the nature of injuries if the child is taken out of the home and placed with a foster family, or in criminal trials against the perpetrators of abuse. See also: Child Development; Child Mental Health;
Child Safety.
Bibliography. Cynthia Crosson-Tower, Understanding
Child Abuse and Neglect, 7th ed. (Allyn & Bacon, 2007); Lisa Aronson Fontes, Child Abuse and Culture: Working with Di-
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verse Families (Guilford, 2005); Beth M. Schwartz-Kenney, Michelle McCauley, and Michelle A. Epstein, eds., Child Abuse: A Global View (Greenwood, 2000). Annie Dude University of Chicago
Child Behavior Disorders The vast majority of children display a range of behavior problems such as whining or disobeying; however, some children experience more severe behavior problems, known as behavior disorders. There is not always consensus on when a problem becomes a disorder. The field of child behavior disorders is a relatively new one and the study of childhood disorders from a developmental perspective has become known as developmental psychopathology. It is now recognized that the developmental level of the child is a prime consideration in assessing and treating behavior problems in children. It is often less the behavior per se and more the appropriateness of the behavior for a child of a certain age that makes a behavior problem a behavior disorder. Adult models of psychopathology may not be relevant for childhood problems; however, many adult problems stem from childhood disorders and many childhood disorders have lifelong consequences. With better attention to child behavior disorders, children may lead better lives and adult psychopathologies may be reduced. Estimates suggest 10 to 20 percent of children have a behavior, emotional, or learning disorder at any one time. These developmental disorders are most often diagnosed when the child is school aged. Children undergo rapid change physically, psychologically, and cognitively and their behavior needs to be evaluated in a developmental context compared to their peers. To determine whether their behavior is a developmental variation or pathological depends on the child’s age, the frequency and intensity of the behavior and the overall environment. For example, hitting to resolve a dispute, temper tantrums, or bed-wetting are not unexpected at age 2, but most inappropriate at age 12. Unlike adults who may self-refer, children are usually referred for assessment by parents. Parents’ own emotional states and tolerance for disruptive behaviors
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influence whether they will refer. Further, the younger the child, the more information comes from the parent about the child, rather than directly from the child. One of the most widely used tools to classify childhood disorders is the Child Behavior Checklist developed by Thomas Achenbach. Two factors on this scale are involved in the majority of behavior disorders. First is externalizing behavior such as aggression and hyperactivity, while the second is internalizing behavior such as depression and anxiety. This approach is based on large-scale normative data and the rating scales are available for parents, teachers, and youth. A clinical approach to diagnosis of childhood disorders is found in the Diagnostic and Statistical Manual of Mental Disorders, 4th edition, technical revision (DSM-IV-TR). The DSM recognizes several broad classes of childhood disorders including intellectual problems such as developmental delays, developmental problems such as autism, behavior problems such as conduct disorder, emotional problems such as anxiety, and physical problems such as bedwetting. Child behavior problems may exist on their own or with other problems. The most common developmental disorder is attention deficit disorder with or without hyperactivity (ADD or ADHD). Because children with ADD/ ADHD may be difficult to discipline, parenting may be affected. Equally common are anxiety disorders, with separation anxiety unique to children. Disruptive behavioral disorders include aggression, conduct, and oppositional defiant disorder. Mood disorders including depression are less common in children but increase during adolescence. Other major categories include sleep, eating, and tic disorders. Cognitive-behavior therapy in some form is the most utilized and effective treatment approach for childhood behavior problems. Many times, it is the parent who is taught to employ the technique and success depends to a large extent on the willingness of the parent to be actively involved. Drugs are used less frequently with children due to unknown risk factors, with the notable exception of stimulant treatment for attention disorders (which is most effective when combined with behavioral interventions). Psychoanalytic therapies including talk therapy are less frequently used with the exception of play therapy. Behavior disorders in children stem from many causes including polygenic and neurobiological fac-
tors, infant temperament, family relationships (including attachment issues and parenting), psychological issues in parent and child, and micro- and macro-social factors. Treatment and intervention programs must recognize the diversity of causes and outcomes. Providing support to diagnosed and at-risk children may improve their lives as children and as adults, including reducing the number of adolescents who end up in the justice system. SEE ALSO: Attention Deficit Disorder; Attention Deficit
Disorder with Hyperactivity; Autism; Developmental Disabilities; Hyperactivity. BIBLIOGRAPHY. T. Achenbach, Manual for the Child Be-
havior Checklist/4-18 and 1991 Profile (University of Vermont, 1991); Richard Behrman, Robert Kliegman, and Hal Jenson, Nelson Textbook of Pediatrics, 17th ed. (Saunders, 2004); Diagnostic and Statistical Manual of Mental Disorders, 4th ed., technical revision (American Psychiatric Association, 2000); Eric Mash and Russell A. Barkley, eds., Child Psychopathology, 2nd ed. (Guilford, 2003). Elizabeth Levin, Ph.D., C.Psych. Laurentian University Lauren Bonder McMaster University
Child Dental Health Despite advances in dental science and notable preventive efforts, dental decay (caries) continues to cause untold childhood pain and dysfunction around the globe and remains the single most common chronic childhood disease in the United States. In the United States, dental decay is five times as common as asthma and seven times as common as hay fever. This preventable health problem begins early: 17 percent of children 2 to 4 years have already had decay. Among low-income children, almost 50 percent of tooth decay remains untreated. Worldwide, dental decay is a dynamic, active, multifactorial disease process that manifests on children’s teeth in an orderly and predictable way. The daily reality for children with untreated oral disease is often persistent pain, inability to eat comfortably or chew well, embarrass-
Child Development
ment at discolored and damaged teeth, and distraction from play and learning. Teaching a child proper oral care at a young age is an investment in his or her health that will pay lifelong dividends. When infants are born, almost all of their primary or baby teeth have already formed, although they are still hidden in the gums. They typically begin to erupt through the gums when the baby is about six months old. Usually, the first baby teeth to erupt are the two bottom front teeth. Next come the top four front teeth. From here, teeth slowly begin to fill the mouth, usually two at a time on either side of the jaw. A child should have all 20 primary teeth by the time he or she is 36 months old. The first tooth should be a sign that it is time for a child’s first dental visit. Although primary teeth eventually fall out, they are just as important as the 32 permanent teeth. Primary teeth help the child bite and chew food, and save space and guide the child’s permanent teeth. The World Health Organization advocates a riskfactor approach for the promotion of oral health. Central to this approach is the enhancement of individual behaviors including adoption of oral hygiene efforts and control of dietary sugar consumption. Fluoride is one of the best ways to help prevent tooth decay. A naturally occurring mineral, fluoride combines with the tooth’s outer layer (enamel) to strengthen it. In many municipal water supplies, the right amount of fluoride is added for proper tooth development. The local water district should be able to provide information as to whether the water contains fluoride and how much. If the water supply does not contain any (or enough) fluoride, the child’s pediatrician or dentist may suggest using fluoride drops or a mouth rinse in addition to a fluoride toothpaste. If fluoride is a child’s greatest protection against tooth decay, then frequent snacking may be the biggest enemy. The sugars and starches found in many foods and snacks such as rice, cookies, candies, dried fruit, soft drinks, pretzels, and potato chips combine with plaque on teeth to create acids. These acids attack the tooth enamel and may lead to dental decay. Each “plaque attack” can last up to 20 minutes after a meal or snack has been finished. A balanced diet is necessary for a child to develop strong, decay-resistant teeth. In addition to a full range of vitamins and minerals, a child’s diet should include plenty of calcium, phosphorous, and proper levels of fluoride.
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Fluoride and a balanced diet are not the only components of children’s oral health and prevention of dental decay. There are other components that extend globally to include establishing a dental home and a proper brushing and flossing regimen that ultimately contribute to children’s dental health. SEE ALSO: American Dental Association (ADA); Dental
Health; Fluoride.
BIBLIOGRAPHY. Children’s Dental Health Project, “Chil-
dren’s Dental Health,” www.cdhp.org (cited October 2006); B.L. Edelstein, “Pediatric Caries Worldwide: Implications for Oral Hygiene Products,” The Compendium on Continuing Education in General Dentistry, (v. 26/5, Suppl. 1, 2005); H. Harris and A. Christen, Primary Preventive Dentistry (Appleton and Lange,1995); P.E. Petersen and M.A. Lennon, “Effective Use of Fluorides for the Prevention of Dental Caries in the 21st Century: The WHO Approach,” Community Dentistry and Oral Epidemiology (v.32, 2004). Jonelle S. Grant, D.D.S. University of North Carolina at Chapel Hill
Child Development Child development describes the physical, cognitive, emotional, and social growth of the child from birth to adolescence (some definitions include the prenatal period). The field of child development is part of a larger discipline known as developmental psychology (or human development in its interdisciplinary form), which is concerned with identifying and understanding systematic changes in the individual across the lifespan. Interest in child development stems from many disciplines—biology, psychology, sociology, education, medicine, and so forth. However, psychologists have played a predominant role in research and applied work in the area of child development. Development is best described as a continual, cumulative, and holistic process. Changes in one aspect of development (e.g., language) have important implications for other aspects. While the average features of development proceed through a relatively regular, sequential process of change (normative
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development), there are individual variations (idiographic development). Maturation and Learning An important process underlying developmental change is maturation (sometimes called predetermined development). Maturation refers to the biological unfolding of an individual according to the hereditary information passed from parents to child at the moment of conception (fusion of gametes). Growth is guided by an inherent process, or an inborn maturational blueprint. This process helps explain how all children follow the same sequence of changes during development (biological program). In this manner, the discontinuous or stage theory of development is attributed in many respects to our biology. Stage theorists accept that development takes place through a series of unique steps, each characterized by qualitative changes in physical attributes, thought, emotions, and behavior. For example, a certain degree of physical maturation is necessary in order for a child to sit up and then walk. Further development is predicated upon already-existing achievements. A second developmental process is learning. Learning refers to changes in cognition, feelings, and behaviors as a result of a child’s experiences. Children develop within context: While a certain level of physical maturation is required in order for a child to read (e.g., brain development), experience (e.g., reading instruction, practice) will promote the ability to read. In other words, developmental changes occur due to environment. Unique historical/cultural contexts (from the familial to a broader level) transmit patterns of beliefs, customs, values, and skills through socialization. Abilities are just as dependent on modeling, practice, and the motivation to engage in particular behaviors as physiological maturation. Indeed, the concept of developmental readiness depends upon a combination of heredity and experience. Experience may facilitate development when the necessary maturation has occurred. There is a long-standing debate about the relative influence of heredity (nature) or environment (nurture) on development. Early theorists (e.g., Arnold Gesell, 1880–1961) emphasized genetics as the determining factor. There has been little disagreement over the predominant role of genetics in the determination of individual differences in physiology.
However, there has been less certainty regarding the influence of heredity on cognitive and social behavior. In general, theorists who believe developmental attributes are resistant to modification (plasticity or capacity to change) emphasize the importance of genetics. Those who regard environment as important emphasize early learning experiences as affecting development through to adulthood. Contemporary theorists generally accept that unique combinations of nature and nurture affect development, but there is still contention over which contributes most to particular developmental changes. Motor Development The first two years of life are marked by rapid physical growth and maturation. Infants make remarkable progress with controlling their movements and the mastery of motor skills. All of the senses (e.g., smell, touch) are operative at birth, and a number of primitive reflexes are predominant for the first three to four months of life. One such reflex is sucking behavior. Locomotor (e.g., crawling, walking) and early manipulatory skills (e.g., reaching, grasping) evolve in a definite sequence (termed milestones). For example, infants, on average, roll over and display visually guided grasping movements at about 3 months of age, sit alone at 5 months, and walk at 1 year of age. The similarities between physical and motor development tend to suggest the role of genetics in motor progress. However, despite a similar pattern, there are individual differences in the rate at which different children progress through the milestones. Motor development does not simply unfold as maturation proceeds; it is an action system wherein existing capabilities are combined into more complex behaviors— guided by exploration and practice (called dynamic systems theory of motor development). Environmental experience generates curiosity and goal-oriented behavior, which impact the emergence of motor skills. Likewise, developing motor skills affect other aspects of development. For example, exploration may guide perceptual development through object searching. Development unfolds during early and middlechildhood (2–12 years) in much the same way as in the first two years of life. Sensory discrimination, such as accuracy of color matching, depth perception, and auditory capability, improve. Increases in body size, muscle strength, and agility support more com-
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In the concrete operational phase (7–11 years) of cognitive development, reasoning becomes more logical and organized as children apply new information to skills. After age 11, cognition finally becomes the abstract and logical thinking of an adult.
plex locomotor skills, such as running, jumping, and throwing a ball. At the same time, eye–hand coordination and fine motor skills are developing. Children proceed through a series of developmental milestones where previously acquired skills are integrated into more complex systems. Skills are refined as children develop and are faced with new experiences. Cognitive Development Cognitive development, including concept formation, problem solving, and reasoning, refers to the process through which children acquire and use knowledge. Jean Piaget’s (1896–1980) cognitive-developmental theory has been one of the most influential explanations of how intellectual skills develop. In contrast to the early neo-behaviorist viewpoint (e.g., where learning occurs through reinforcement of behavior), Piaget proposed that children actively create knowledge as
they interact with their world. This is described as the constructivist approach to cognitive development. Cognitive structures develop through assimilation (interpreting new experiences in terms of existing models of the world) and accommodation (modifying information to meet new situations). Development is characterized by the continual organization (e.g., rearrangement) of the cognitive structures to produce a more elaborate cognitive system. Piaget divided cognitive development into four stages that are characterized by qualitatively different skills. In the sensorimotor stage (birth–2 years), the infant coordinates sensory information and motor movements to explore the world. A hallmark of this stage is the development of object permanence, or the idea that an object continues to exist, even while out of sight. The preoperational stage (2–7 years), is characterized by symbolic, yet illogic, thought. Make-believe
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play and the development of language take place during this stage. Symbols and language are increasingly used to represent the child’s world. In the concrete operational phase (7–11 years), reasoning becomes more logical and organized. Children are applying new information to skills. In the final stage of formal operations (11 years–adult), cognition becomes the abstract and logical thinking of the adult. Although Piaget made a lasting contribution to our understanding of cognitive development, his work has been challenged. Recent work has led to several refinements of his theory. Current theories do not place as much emphasis on the stage-like processes of cognitive development as Piaget did (e.g., information processing perspective). Children are continually refining and acquiring new cognitive skills; few abilities are present in one distinct stage and not another. Other theoretical perspectives emphasize the influence of the social world on cognitive development (e.g., sociocultural theory). A child’s development is a socially mediated process, and is affected by interactions with others within a unique cultural context. Children actively construct knowledge (self-generation of cognitive ability), but also develop within the complex, multilayered system of their environment (ecological-systems theory). Language Development Language development illustrates the combined influence of inherent ability and experience. Infants are capable of vocalizing at birth. Babies coo (vowel-like noises) and babble (consonant-vowel-like combinations) in the first few months of life. This is called prelinguistic vocalization. Infants are quite receptive and responsive to language at this time. They are sensitive to the sound of voices and their native tongue, and respond through gestures and other nonverbal cues (e.g., facial expressions). The complexity of communication changes from vocalizations to one-word utterances to combinations of words into simple sentences by the time a child is 2 years of age. Early words are linked to specific cognitive achievements. For example, the development of object permanence corresponds to disappearance terms, such as “all gone.” Children can also connect a new word with its underlying concept after only a brief encounter (fast mapping). Child–caregiver interaction is a powerful influence; verbal prompts,
imitation, and expansion on a child’s language promote further language development. In the preschool years (2½–5 years of age), children come to produce relatively complex sentences. With this complexity comes the ability to conform to rules of language. Inflections are used, like singular and plural for nouns, and tense for verbs. Children become capable of asking questions and of connecting sentences/embedding one sentence within another. They can express relational contrasts (e.g., big/little), and adapt language to social expectations. Conversational skills are acquired that enable the child to communicate more effectively with others. By middle childhood, children become better listeners and manipulate language through more complex grammatical structures. The development of comprehension is marked by meta-linguistic awareness (the ability to think about language) and make inferences regarding the meaning of sentences. As children move from childhood to adolescence, they become more effective at communication through linguistic refinement and social experience. Emotional and Social Development Social and emotional development begin early in life. Interest, fear, disgust, joy, sadness, and anger emerge during the first year. More complex emotions, such as embarrassment and pride, are displayed in the second or third year as children develop self-recognition. These emotions are sometimes called self-conscious emotions as they either enhance or injure our sense of self. Emotional expression (e.g., happiness, crying) powerfully affects the behavior of others. Parents attend to their infants’ unpleasant feelings and become less responsive to negative behavior. In this way, an elaborate communication system develops between caregiver and child. The child’s emotions are adaptive in that they assist caregivers with meeting the infants’ needs and goals. At the same time, the ability to recognize and interpret others’ emotions serves an important social referencing function (use of another’s emotions to interpret an unfamiliar situation). Patterns of emotional and verbal responsiveness between a mother and her child lead to what is called attachment (emotional/affectionate bond). Young children learn to judge/interpret others’ emotions and gain emotional understanding through their developing cognitive skills and early socializa-
tion with caregivers, especially mothers. They begin to use language to assist with the self-regulation of emotion and can verbalize a variety of emotional selfregulation strategies around 2 to 3 years of age. With greater cognitive ability, school-age children can understand the needs and expectations of others, and their ability to live up to these expectations affects their self-concept. At the same time, an increase in empathy enables children to better understand the feelings of others. They test their self-concepts by making comparisons with peers and they develop the ability to imagine how others evaluate them. This allows them to anticipate evaluations, correct their behavior, evaluate the action, and react to it emotionally. Children have also developed more ways to deal with emotionally arousing situations through the increasing development of emotional self-regulation. Two theories have been particularly influential in the area of thought and research on social development. Historically, the psychoanalytic perspective (Sigmund Freud, 1856–1939) describes children as moving through stages in which they encounter conflict between biological drives and social expectations. The manner in which conflict is resolved determines how children learn and socialize with others. The progression of children through the stages is the basis for personality in later life. On the other hand, social learning theory (e.g., Albert Bandura, 1925–) emphasizes modeling (imitation or observational learning) as the major source of social development. Currently, this perspective places great emphasis on the role of cognitive processes in social development. It also emphasizes social learning as reciprocal determinism. Reciprocal determinism is the complex interactions that occur between an “active person,” the person’s behavior, and their environment. SEE ALSO: Adolescent Development; Genetic Code; In-
fant and Toddler Development; Physiology; Psychologist; Psychology. BIBLIOGRAPHY. Jacqueline Barnes, Children and Fami-
lies in Communities: Theory, Research, Policy, and Practice (Wiley, 2006); Laura E. Berk, Child Development, 7th ed. (Pearson Education, 2007); Gavin Bremner, Theories of Infant Development (Blackwell, 2004); Catherine R. Cooper, Developmental Pathways through Middle Childhood: Rethinking Contexts and Diversity as Resources
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(Lawrence Erlbaum, 2005); Andreas Demetriou, The Development of Mental Processing: Efficiency, Working Memory, and Thinking (Blackwell, 2002); Jeffrey M. Jenson, Social Policy for Children and Families: A Risk and Resilience Perspective (Sage, 2006); Robert V. Kail, Children and Their Development, 4th ed. (Pearson Education, 2007); Yuriy V. Karpov, The Neo-Vygotskian Approach to Child Development (Cambridge University Press, 2005); Heidi Keller, Between Culture and Biology: Perspectives on Ontogenetic Development (Cambridge University Press, 2002); Jacqueline Nadel, Emotional Development: Recent Research Advances (Oxford University Press, 2005); Catherine Raeff, Social and Cognitive Development in the Context of Individual, Social, and Cultural Processes (Routledge, 2003); Neil J. Salkind, Child Development, 4th ed. (Macmillan, 2002); David R. Shaffer, Developmental Psychology: Childhood and Adolescence, 6th ed. (Brooks/Cole, 2001). Diana Urajnik University of Toronto Elizabeth Levin, Ph.D., C.Psych. Rashmi Garg Laurentian University
Childhood Cancers Childhood cancers are considered to be rare. In the United States an estimated 9,500 new cases were expected in 2006 and in European countries 1 in 500 children is estimated to be diagnosed with cancer before the age of 15. Despite these statistics, cancer is the leading cause of death by disease among children from infancy to age 15. Contributing factors to childhood cancer include infection, environmental factors, genetic susceptibility and other factors. Infection may overwhelm the immune response or leave the person susceptible to another opportunistic infection. Environmental factors include, but are not limited to, electromagnetic radiation, secondhand smoke, contamination of food supply by radiation, medications used as chemotherapy, food additives, and pesticides. The Chernobyl accident is linked to 691 cases of thyroid cancer in children in Belarus. Genetic susceptibility might be familial tendency to cancer without the specific cause having been
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identified or it might be an identified genetic marker with mutations. Altered oncogenes create normal proteins in abnormal amounts, proteins with abnormal structures or unregulated cell proliferation as in Burkitt’s lymphoma the c-myc oncogene is activated. The tumor suppressor gene codes for or controls the regulatory proteins to suppress proliferation as in soft tissue sarcoma the P53 gene (normally triggering programmed cell death) has a mutation causing the accumulation of the cancer cells. Mutator genes function to repair DNA damage from environmental or other factors, when a mutation occurs the DNA damage accumulates. Childhood cancers affect stem cells (simple undifferentiated cells capable of producing many different specialized cells. Childhood cancers can more often be cured, lead to clinical remission. According the data from Surveillance, Epidemiology and End Results (SEER) Program and the American Cancer Society, the combined five-year survival rates for all childhood cancers has improved from 56 percent in the 1970s to 79 percent in the 1990s. Cancers are named and classified depending on the site of the abnormal cells, the tissue infected and the degree of loss of normal cell growth. The naming and classification helps the oncologist determine the appropriate method of treatment and to minimize side effects from the treatment. Of the various childhood cancers, 11 are the most common making up approximately 89 percent of the cases diagnosed. Leukemia Leukemia is malignant neoplasm of the blood forming tissues. With longer cell cycles and decreased growth fractions, these cells have a slower growth than normal cells accompanied by slowed programmed cell death allow them to accumulate in the bone marrow and replace normal hematopoietic cells. These cells are in the blood and can infiltrate any organ or site. They most often disrupt the function of the central nervous system and the bone marrow leading to anemia, thrombocytopenia or granulocytopenia The classification of acute means the cells are immature cells. Malignancy begins in a single often pluripotent or committed stem cell that proliferates. Risk factors for leukemia include exposure to ionizing radiation, chemicals (benzene, some antineo-
plastic drugs use for chemotherapy and genetic abnormalities. Symptoms generally have caused illness for a short time, just days or weeks and include fatigue, fever, malaise, weight loss, and bleeding. Acute lymphoblastic leukemia is diagnosed by the higher incidence of leukemic lymphoblasts or lymphocytes (the B cells and T cells) in the white blood cells that fight infection. Acute myelogenous leukemia affects any of the blood cells (the major types are red blood cells carrying oxygen to the body’s cells, white blood cells and platelets helping to from clots and to control bleeding). Lymphoma Lymphomas are neoplasms in the lymphatic system. Staging the disease depends on spread. Stage 1 is one lymph node involvement, Stage II involves one side or in the chest or abdomen, Stage III involves both sides, Stage IV includes bone marrow or liver involvement. Additional staging factors take into account constitutional symptoms. Subtype A shows no constitutional symptoms and Subtype B shows symptoms including a 10 percent weight loss over six months. Hodgkin’s disease is local or disseminated malignant proliferation of tumor cells in the lymph node tissue and bone marrow. The lymph controls infection by decreasing fluid at infections and removing foreign invaders. The lymph also collects and transports white blood cells. Although rare before the age of ten, see in children under 14 and in young adults 15–35. The cells rise in a single lymph node and spread to nearby lymph nodes. Hodgkin’s is characterized by the presence of Reed-Sternberg cells (large bi-nucleated cells). Symptoms include painless swelling or a palpable mass in the feet, neck, groin, and underarms along with general symptoms of fever, weight loss, night sweats, and itching. Treatment is chosen for maximum result while limited sideeffects radiation for decreased risk and might include radiation, chemotherapy, and/or surgery. Non-Hodgkin’s Lymphoma Cancer of the lymphoid tissue (lymph nods, tonsils, sinuses, and peripheral) occurs in sites of immune system activity including bone marrow, spleen, liver, or gastrointestinal tract. Local disease is apparent, most have multiple areas involved. Symptoms vary by site and type of cells involved. Burkett’s lymphoma is in the
B-cells, lymphoblastic is in the T-cells and large cell lymphoma is in larger cells than those previously mentioned. Lymphoblastic or large cell lymphoma may arise from tissue next to the heart. Nausea and vomiting and abdominal pain may indicate Burkitt’s. Spread to the central nervous system (brain or spinal cord) may show in facial muscle weakness and constitutional symptoms of fever, night sweats, and weight loss. Treatment is based on aggressiveness of the disease, low, intermediate, or high. The limited stage involvements require less aggressive treatment while more advanced stages will require more aggressive treatment. Solid Tumors Solid tumors classification is based on the site, carcinoma affects the surface cell layer, sarcoma affects cells other than the covering layer Retinoblastoma Retinoblastoma is a tumor of the immature retina observed by ophthalmoscopy. The tumor and calcification can be seen by imaging. Because of the familial nature of the infection, family members should be evaluated as well. Treatment is by removal of the intraocular tumor and destroying damaged tissue. Chemotherapy is indicated when the disease has progressed beyond the globe. Re-exam is necessary as the incidence of additional infections is increased. Neuroblastoma Neuroblastoma is a solid malignant tumor mainly in the adrenal gland and extra adrenal sympathetic chain often appearing in the abdomen, thorax, neck, or pelvis. Symptoms vary by site of infection possibly including enlarged liver, bone pain, anemia, and bruising. A palpable mass can be felt on examination and diagnosis by imaging for size and nature and testing the bone marrow for metastatic involvement. Treatment is by surgical removal of the localized and primary regions with combination therapy of chemotherapy and radiation for advanced disease. Tumors of Bones and Joints Because of location, these tumors are difficult to diagnose. Patients will often present with persistent or unexplained pain. Osteosarcoma the tumor grows in the metaphysis toward the end of long bones, often in the region of the knee. Pain and mass are the usual
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symptoms and can be seen with imaging. Biopsy of the tumor is necessary for diagnosis. Treatment includes removal of the tumor, in the past this often included amputation of the affected limb, surgeons now have techniques to remove the tumor while keeping the limb intact. Because of likelihood of metastasizing often to the lung, chemotherapy is necessary and used pre-operatively and postoperatively. Ewing’s sarcomas are seen first in the shaft of long bones of the extremities. The sarcoma is a round cell bone tumor. Patients complain of symptoms of pain and swelling. Imagining shows lytic destruction and/ or multiple layers. Treatment is by chemotherapy, surgery, and radiation. Brain Tumors Brain tumors in children are most often cerebellar astrocytomas and medulla blastomas, ependymomoa, gliomas of the brain stem and optic nerve, germinomas, and congenital tumors. The common metastatic tumors are often epidural neuroblastoma and meningeal leukemia. The cells invade and destroy normal tissue. Symptoms include intracranial pressure with headaches, vomiting and mental changes, drowsiness, lethargy, and seizures. Complete removal of the tumor is desirable along with a shunt to move cerebrospinal fluid around the brain because the tumor may have been obstructing. Radiation may be necessary because of the potential for reoccurrence and chemotherapy to prevent tumor growth. Fewer effective chemotherapy medications are available because they will not cross the blood-brain barrier (a protective mechanism to prevent infection). If chemotherapy is used it is in high doses and requires the need for rescue of cells by removal of stem cells for later reintroduction. Liver Cancer Liver cancer because of the blood supply the liver is a fertile site for blood borne tumors. Symptoms include weight loss, anorexia, fever, and an enlarged liver progressing to jaundice. Imaging and liver biopsy confirm diagnosis. Treatment begins with temporary tumor shrinkage by infusion of chemotherapy via the hepatic vein to decrease systemic effects. The affected tissue can be surgically removed including part of the liver because liver tissue can regenerate. If surgery isn’t successful, the prognosis may be grim; radiation and chemotherapy are not very effective.
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Rhabodomyosarcoma Rhabodomyosarcoma is a soft tissue sarcoma affecting almost any part of the body though most often seen in head and neck, genitourinary tract, arms, legs, or trunk. The tumor tissue develops in the immature fat cells that become fat cells, cartilage, fibrous tissue, muscles cells, and bone cells. Although predisposing factors are not fully known, rhabdomyosarcoma has been seen in families. Symptoms vary depending on location and range from a protrusion, to sinus problems (if the head/neck is involved), pain, and lymph node swelling. To confirm diagnosis the tumor tissue is removed by biopsy for testing. Treatment will depend on tumor size and stage. Surgery will quickly remove small, accessible tumors. Radiation and chemotherapy combined with surgery. Treatment Measures Used by Oncologists Treatment options depend on the type of cancer, the location and how aggressive or advanced the cancer. The oncologist will follow a protocol for each disease and make recommendations to eliminate the cancer with a single or combination of therapies. Surgery Removal of the primary tumor and involved structures is intended as a cure to make sure the tumor does not regrow. Surgery may also be performed to provide additional diagnosis and supportive care (biopsy for diagnosis, placement of catheters for drawing blood or administer chemotherapy medications or tubes for feeding, repair complications, to determine extent of cancer spread. Radiation Therapy Radiation kills cancer cells in the similar manner to how X-rays work. Each patient is evaluated for type of cancer, site of cancer, and effectiveness of radiation therapy. The radio-oncologist prescribes the amount of radiation, where the radiation is to be given, the frequency (how many times per day) and duration (for how long or number of treatments). A linear accelerator is used to administer the dose of radiation in the exact area needed in the right amount to destroy cancer cells without destroying healthy tissues. Depending on the type of cancer and the site, the oncologist will determine if radiation therapy is appropriate.
Chemotherapy Chemotherapy has improved the expectation of normal longevity with the use of antitumor agents especially seen with acute leukemia, Ewing’s, Hodgkin’s, lymphosarcoma, rhabdomyosarcoma, and retinoblastoma in childhood cancers. Antineoplastic medications have been used since the first chemotherapy drug was used successfully in 1941 and in 1942 researchers discovered that mechlorethamine was effective against Hodgkin’s disease. Antineoplastic agents are classified by effects on cell survival as a function of the dose. Alkylating agents transfer alkyl groups to cellular constituents leading to cell death, antimetabolites act on the intermediary metabolization of proliferating cells, mitotic inhibitors involve inhibition of cell cycle phase, antibiotics inhibit growth (the ones used in cancer treatment are cytotoxic), and other miscellaneous chemotherapeutic compounds act on other pathways with new chemotherapy compounds having increasing selectivity for cancer cells. Chemotherapy might be considered a case where the cure is as painful as the bite. Challenges with administering chemotherapy include toxicity. Toxicity to cancer cells also means toxicity to normal cells. Numerous toxic side effects ranging from nausea and vomiting, tiredness to diminished blood counts, damage to other organs (kidney, liver, bone marrow), and even secondary cancers. Bone Marrow Transplant Bone marrow transplants are used in bone marrow cancers (like leukemia) to replace infected bone marrow with healthy bone marrow. Before the transplant the damaged bone marrow is destroyed with chemotherapy or radiation to kill the cancer cells. Stem cells in bone marrow create all the blood cells and these stem cells are transplanted into the bone marrow. This is often not always a first line of treatment, but used for relapses or recurrences or for rescue treatment after high-dose chemotherapy. Immunotherapy The immune system protects the body from infection with a cascade of responses with white blood cells (B-cells and T-cells). In cancer patients, chemotherapy and radiation damage the white blood cells as well as cancer cells. Injection of antibodies in immunoglobulin provides protection against sec-
ondary infections. Cancer patients who have a bone marrow transplant may need additional T-cells to fight infection. Cancer research is being conducted on using T-cells to fight tumor cells. Alternative or Complementary Therapy Alternative therapies are intended to take the place of conventional medical therapy (surgery, chemotherapy, and radiotherapy). Complementary therapies enhance conventional medical therapies. These therapies tend to be controversial with minimal scientific evidence to justify the claims. The National Center for Complementary and Alternative Medicine maintains a searchable Web site to provide information and recommendations on therapies currently showing scientific evidence of therapeutic benefit. When considering the use of therapies in addition to conventional medicine, the patient/family should discuss the possibility with the attending oncologist to make sure the therapy will not interfere with cancer treatment and is appropriate. Physicians should educate themselves on alternative and complementary therapies to discuss them knowledgably with patients and to provide the best possible long-term quality of health. Additional Factors and Concerns Cancer treatments are time consuming, often take place over a long term and can make the patient experience additional distress and illness. These factors can lead to additional stress in relationships and interfere with education and social life. When cancer progresses to the point of being untreatable, dealing with the process of dying may require additional supportive therapy for the patient and family from mental health professionals, the patient’s spiritual community as well as the medical team. The goal is to improve treatment program to maintain or improve cure from childhood cancer in the long term, to reduced treatment-related side effects and increase quality of life for the entire lifespan. Continued goals must include research into the causes of cancer, continued funding for these research activities as well as to provide testing and treatment around the world and to improve access. See also: Cancer (General); Chemoradiotherapy; Che-
motherapy; Immunotherapy; Oncologist.
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Bibliography. “Children at Risk Main Health Effects
of Exposure to Environmental Factors,” (World Health Organization Fact Sheet, May 2003); “National Cancer Institute A Snapshot of Pediatric Cancer,” www.planning.cancer.gov (cited August 2007); Hope S. Rugo, “Cancer,” Current Medical Diagnosis & Treatment 2004, (Lange, 2004); Sydney E. Salmon, and Alan C. Sartorelli, “Cancer Chemotherapy.” Basic and Clinical Pharmacology (Appleton and Lange, 1998); Grant Steen, and Joseph Mirro, eds., Childhood Cancer A Handbook from St. Jude Children’s Research Hospital, (Perseus Publishing, 2000); William B. Young, and Stephen D. Silberstein, Migraine and Other Headaches (American Academy of Neurology, 2004). Lyn Michaud Independent Scholar
Childhood Immunizations Childhood immunizations have been the most effective way to control the extensive transmission of infectious diseases. Immunizations have the potential to protect children from life-threatening diseases, save the community from widespread epidemics, and improve overall global public health. With the development of vaccines, preventing the spread of infectious diseases through the use of immunizations has been a remarkable success. Vaccines are designed to protect individuals from disease by eliciting an immune response in the body. Vaccines cause the human body to perceive that it is being invaded by a foreign pathogen, or disease-causing organism. The body then produces antibodies. If the pathogen was to invade the body again, the antibodies would recognize and destroy it. Vaccines can be made in a variety of ways. All vaccines are designed to prevent future infections using the same mechanism of triggering an immune response in the body. There are currently four different types of traditional vaccines. Live attenuated vaccines are weakened forms of the pathogen. They generally produce a long-lasting immune response, but can potentially change back to their original pathogenic form. Inactivated vaccines are a killed form of the microorganism. These vaccines create
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a short-lived immune response and often require subsequent doses in order to become effective. Toxoid vaccines allow the body to think that it is a toxin released by certain toxin-producing bacteria. These vaccines produce an immune response against a specific toxin that is released into the bloodstream by toxin-producing bacteria. Subunit vaccines are generally vaccines that consist of a fragment of the pathogen. These vaccines can also produce an adequate immune response during future infections. Vaccines must be administered in a timely manner in order to be most effective at producing an immune response in the body. According to the updated Centers for Disease Control and Prevention’s (CDC) Recommended Immunization Schedule for 2007, the standard immunization series administered between 0 and 18 months include four doses of diphtheria, tetanus, and pertussis (DPaT) vaccine, three doses of Rotavirus (Rota) vaccine, three doses of polio vaccine, three doses of Haemophilus influenzae type b (Hib) vaccine, three doses of Pneumococcal vaccine (PCV), and three doses of hepatitis B (HepB) vaccine. The first dose of the measles, mumps, and rubella (MMR) vaccine and the varicella vaccine is recommended at the age of 1, while the second dose of these vaccines is recommended between 2 to 4 years of age. The immunization series also recommends two doses of the hepatitis A (HepA) vaccine for children older than the age of 1 and a yearly influenza vaccine. Following this immunization schedule in a timely manner will significantly reduce the risk of contracting these infectious diseases during the remainder of a child’s life. Immunizations have been successful in eradicating diseases worldwide. As a result of the Smallpox Eradication Program launched by the World Health Organization (WHO), the last case of smallpox in the world was seen in 1977. The eradication of smallpox was one of the most significant public health interventions in history. Similarly, diseases such as measles, polio, diphtheria, tetanus, pertussis, rubella, mumps, and Hib are no longer prevalent because of the widespread implementation of immunizations. With the development of eradication programs, the WHO continually aims to eliminate infectious diseases at the global level through the use of immunizations. The administration of immunizations to children is a cost-effective public health intervention because it can protect children from deadly infectious diseases
for life. However, there are still many children around the world who have not received their vaccinations, making them susceptible to contracting and spreading infectious diseases. This gap in immunization coverage could be a result of disparities in pediatric healthcare. Although elimination of overall disparities in healthcare has surfaced as a pivotal challenge for healthcare delivery around the world, it has also posed a problem in administering immunizations to all children. Most importantly, immunizations can prevent excessive morbidity and mortality, thereby allowing children to ultimately lead healthier lives. By facilitating access to preventative healthcare, getting immunized in a timely manner can help avoid high costs of future hospitalizations and medical visits. Because reducing healthcare disparities has been a crucial challenge around the world, the best place to begin eliminating these disparities should be at the preventative stage. As a result, focusing on increasing immunization coverage among children will significantly improve overall health outcomes around the world. SEE ALSO: Adult Immunization; Disease Prevention; Im-
munization/Vaccination; Infectious Diseases (General).
BIBLIOGRAPHY. American Academy of Family Physicians,
“Childhood Vaccines: What They Are and Why Your Child Needs Them, 2006,” www.familydoctor.org (cited January 2007); Centers for Disease Control and Prevention, The Importance of Childhood Immunizations (National Immunization Program, 2006); Centers for Disease Control and Prevention, “Recommended Immunization Schedules for Persons Aged 0–18 Years—United States, 2007,” MMWR Weekly (v.55/51, 2007); Centers for Disease Control and Prevention, “Special Report: 50 Years of Immunization Success,” www.cdc.gov (cited January 2007). Priya Menon Johannesburg General Hospital
Child Mental Health Child mental health is defined as the total well-being and optimal development of a child in the emotional, behavioral, social, and cognitive domains. Children’s mental health is often defined as different than adult
mental health and more multifaceted because of the unique developmental milestones that children experience. Characteristics of the child (e.g., gender, genetics) are important determinants of that child’s well-being. However, the definition also includes those conditions that directly affect or modify mental health, including aspects of a child’s family, community, and broader society. The mental health problems children may experience may be reflected as difficulties in psychological and emotional development, social relationships, and behavior. When problems are persistent, severe, and cause impaired functioning, they are defined as mental health disorders. Well-designed mental health promotion/prevention programs and interventions can enhance the well-being of children, and mitigate the escalation of problems. A child’s well-being is influenced by a variety of protective and risk factors. Fostering psychological and emotional health is an important part of good mental health. Children with good mental health are able to develop emotionally and cognitively, form effective social relationships with others, and cope with problems. Protective factors are child and environmental characteristics that enhance positive mental health outcomes by protecting a child/reducing the negative effects created by risk factors. Protective factors can be characterized as child, family, and community strengths that contribute to resilience. Child strengths can include healthy physical status, intelligence, and a relaxed temperament. Family strengths are those characteristic of a cohesive and supportive family (e.g., nurturing parenting style, supervision, socioeconomic advantage). Community strengths can encompass safe schools and participation in recreation activities. The impact of risk factors often leads to poor mental health outcomes in children. The presence of multiple risk factors increases a child’s vulnerability to experiencing a problem. Risks may stem from premature birth and low birth weight, physical health, ethnicity, peer and family relationships, parental mental health status (especially the mother), having parents who abuse alcohol and/or drugs, and witnessing family violence. Many experts cite socioeconomic status (i.e., parental education or income) as a strong predictor of psychological well-being. In addition, particularly vulnerable groups of children are those who have been physically or sexually abused, those in foster care, and refugee
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children. Another subgroup of children are those with learning disabilities. Children with a learning difficulty (e.g., problems in learning and understanding compared with children of the same age) are at increased risk of developing a mental health problem. Clinical definitions of children’s mental health focus on the identification and classification of disorders as well as their treatment and are most often based on the Diagnostic and Statistical Manual for Mental Disorders. Mental disorders cause both diagnostically significant symptoms and functional impairment. Defined in this way, community prevalence rates indicate that 15 percent of children (and youth) may experience a mental disorder at any given time. Anxiety, attention, conduct, and depressive disorders are the most common types of childhood disorders. One in five children may have more than one disorder (comorbidity). These conditions have a negative impact on children’s development and functioning in the home, school, and community. Approximately 50 percent of childhood disorders also persist and can affect eventual adult productivity and functioning. The human and economic impact of mental health disorders places them among the most costly of health conditions. Prevention/Intervention Population-based research has confirmed that many children with mental health disorders do not receive the treatment they need. Recent estimates based on a combination of epidemiological studies indicate that
Community prevalence rates indicate that at any given time, 15 percent of children and youth have a mental disorder.
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only 20 percent of children with disorders receive specialized services. Unmet need is reflected in differential access (particularly for minority children), and may be a result of specific barriers that impede service use. Barriers that inhibit access to services are often comprised of distance to care, wait for treatment, and the stigmatization of mental illness. Other factors can include lack of parental knowledge of available resources, and parent psychosocial functioning (e.g., depression). Furthermore, families who experience social adversity (e.g., family stress, lack of social support) may have great difficulty in accessing care. Children in single-parent or impoverished homes, who experience trauma such as child abuse, or whose families are mobile are significantly less likely to seek help for their mental health difficulties. Difficulties with service use for children with mental health disorders have been emphasized in policy documents aimed at addressing these issues, such as the 1999 Surgeon General’s report on mental health. Efforts to improve access to mental health services have been undertaken, such as systems-of-care, wraparound intervention, and large-scale projects. Some experts have suggested a combination of population health and clinical strategies. This would involve a mix of universal promotion/prevention programs to foster optimal wellbeing for all children, and more targeted interventions delivered in a strategic, cost-effective manner. Recent service models have emphasized holistic, family-centered promotion strategies and care. Intended policy outcomes of programs and services are the optimal development of all children, and the reduction in impairments associated with mental health disorders. SEE ALSO: Anxiety; Attention Deficit Disorder with Hy-
peractivity; Autism; Child Behavior Disorders; Depression; Mental Health; National Institute of Mental Health (NIMH); National Mental Health Association (NMHA); Obsessive-Compulsive Disorder; Psychiatrist; Psychotherapy; Tourette Syndrome. BIBLIOGRAPHY. British Medical Association Board of
Science, Child and Adolescent Mental Health: A Guide for Healthcare Professionals (British Medical Association, 2006); Children’s Mental Health Ontario (CMHO), Children’s Mental Health Services for Children Zero to Six: Review of the Literature and Practice Guide (CMHO, 2002); Michael Epstein, Krista Kutash, and Albert Duchnowski,
Outcomes for Children and Youth with Emotional and Behavioral Disorders and Their Families: Programs and Evaluation of Best Practices, 3rd ed. (PRO-ED, 2006); National Children’s Alliance, Mental Health in Middle Childhood Policy Brief, www.nationalchildrensalliance.com (cited October 2006); United States Public Health Service, Report of the Surgeon General’s Conference on Children’s Mental Health: A National Action Agenda (Department of Health and Human Services, 2000); Charlotte Waddell and Cody Shepherd, Child and Youth Mental Health: Population Health and Clinical Service Considerations (Mental Health Evaluation and Community Consultation Unit, University of British Columbia, 2002). Diana Urajnik Melanie Barwick University of Toronto
Child Safety Children are particularly vulnerable to accidents and their safety requires different approaches than those for adults. Accidental injury kills 1 million children annually worldwide. Ninety-eight percent of these deaths occur in low-income countries, where injury is making significant gains on disease as the leading cause of death in young children. In the United States and most other industrialized nations, accidental injury has surpassed disease to become the number one cause of death among children ages 14 and under. No one device or solution can prevent all types of accidental childhood injuries; instead, child safety requires a multifaceted approach. Safe Kids, a global network of organizations, lists several actions to be considered when creating programs to reduce childhood injuries: educating adults and children about risks, designing of safe environments, conducting research, and advocating for effective laws. One of the main pathways to improving child safety concerns education of parents, caregivers, children, healthcare practitioners, policy makers, and other target groups in order to change knowledge, attitudes, and behavior. Examples of areas in which education about risks is crucial include the use of seatbelts and keeping plastic bags, choking hazards, and toxic materials out of the reach of children.
Chile
With the massive numbers of traffic accidents during the 20th century, much effort has been put into building safer cars, with special care to ensure that children travel safely. According to the Canada Safety Council, the correct use of a child restraint on every trip can prevent 70 percent of crash-related deaths and serious injuries to child passengers. Some common household objects can be extremely dangerous to children. Small objects and plastic wrappings or bags should not be left with unattended children because they are choking hazards. Toxic products, such as cleansers, should be locked away out of the reach of children. Many injuries and deaths are also caused by falls, both outside and inside the house, and often these incidents can be prevented by using simple child safety devices available on the market today. Changing children’s surroundings and influencing design are also key issues when dealing with child safety. Child safety advocates promote the development and manufacture of safer products. This can be achieved by both the issuance and enforcement of regulations as well as through the development of voluntary standards and guidelines enabling injury prevention. In order to provide sustained improvement of child safety, there is a growing need for more research, data collection, and surveillance, as well as evaluation of programs and product effectiveness. Child safety promotion has recently had to expand into new areas, namely concerning the internet. The easy access to online communities and recent cases of children being harassed online by pedophiles have sparked much discussion about how to best monitor the way children interact online. SEE ALSO: Adolescent Health; Child Abuse; Environmen-
tal Health; Safety (General); United Nations Children’s Fund (UNICEF).
BIBLIOGRAPHY. Canada Safety Council, www.safety-coun-
cil.org (cited January 2007); Kurt Eichenwald, “On the Web, Pedophiles Extend Their Reach,” New York Times (August, 2006); Mayo Clinic on Child Safety, www.mayoclinic.com (cited January 2007); Safe Kids Worldwide Network, www. safekidsworldwide.org (cited January 2007). Ricardo Mexia Independent Scholar
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Chile Chile is located on the west coast of South America, with a western border along the Pacific Ocean. The high ridge of the Andes separates it from Argentina on its east. Chile is 4,630 kilometers long—the longest border of any country in the world—and is only 430 kilometers across at its widest point. The northern region is dominated by the Atacama Desert, and its lower tip is close to the Antarctic Circle. After many years of political upheaval, Chile is coming into its own as a stable, democratic country, offering the opportunities of a better life to its substantial population. Chile is home to 16.1 million and growth is slow at 0.94 percent annually. The birth rate is 15.23 per 1,000 people and the death rate is 5.81 per 1,000; the migration rate is stagnant at 0 migrants per 1,000 people. The urbanization rate is 87 percent and continues to grow at about 2 percent annually, although the population density remains fairly low at 22 people per square kilometer. Chile has a mature market economy with a strong agricultural and manufacturing sector. About 8 percent of the country’s 6.3 million workers are unemployed. Per capita income is $4,910 a year, with 18 percent of Chileans living below the poverty line. Extreme poverty is low, with less than 2 percent living on $1 a day. Life expectancy at birth is currently 73.49 years for males and 80.21 years for females; healthy life expectancy is 65 for men and 70 for women. Infant mortality is low at 8.58 deaths per 1,000 live births. Eight of every 1,000 children die before the age of 5. Maternal mortality is 31 deaths per 100,000 live births. Ninety-five percent of women receive prenatal care, and 100 percent of births are monitored by trained attendants. Chile has made great strides in social health and welfare in recent years, although pockets of poverty and isolation remain. The government has launched the Chile Solidario program aimed at providing assistance to the country’s poorest households. In rural areas, only 59 percent of the population have access to clean drinking water and only 64 percent have sanitary facilities, compared to 95 percent of the urban population. With the establishment of a strong epidemiological surveillance program, Chile has managed to eradicate or limit several major infectious diseases. Malaria, plague, dengue fever, and schistosomiasis have been
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eliminated. There has not been a documented case of cholera since 1998, and typhoid is in decline. However, hantavirus is prevalent in rural regions, and meningococcal infections remain endemic in some areas. Most Chileans suffer the common problems of an industrialized nation: Heart disease and cancer are the major causes of death. There are an estimated 500,000 people with diabetes, and that number is expected to grow to over 1 million by 2030. With such a high rate of urbanization, accidents and violence are frequent and deadly. The rate of human immunodeficiency virus (HIV) infection is 0.3 percent, with about 26,000 people living with the virus in 2003. According to the World Health Organization, the government spends approximately $137 per capita on healthcare each year. In 2000, there were 20 “high complexity” hospitals, 196 general hospitals, 526 primary care clinics, and 1,840 rural health posts—about one healthcare facility per 28,500 people. There were 17,250 physicians and 10,000 nurses working within the country in 2003. In recent years, the ministry of health has focused on women and children, increasing the immunization program, and improving cancer screening. SEE ALSO: Healthcare, South America. BIBLIOGRAPHY. Central Intelligence Agency, “Chile,”
World Fact Book, www.cia.gov (cited February 2007); Pan American Health Organization, “Pan American Health Organization 2002 Report,” www.paho.org (cited February 2007); Peter Stalker, ed., A–Z Countries of the World (Oxford Reference Online, 2006); United Nations Children’s Fund (UNICEF), “Chile—Statistics,” www.unicef.org (cited February 2007); World Health Organization, www.who.int (cited February 2007). Heather K. Michon Independent Scholar
China There is little doubt among Chinese leaders that healthcare in China will be challenged in the 21st century. More and better medical services will be needed in coming years because of social develop-
ments and the variety of diseases in China, a country with a population of well over a billion. The income of families in urban areas of China is expected to be three times as high as its current (2006) level by 2020, and as a result there should be much more demand for basic medical services in the cities. In rural areas, family incomes are also expected rise by 2020, causing a similar increase in the need for foundational medical care. A relatively small number of Chinese will become wealthier, and as a result will expect higher quality healthcare. In contrast, as many as 200 million Chinese will still be living at or below the poverty line by 2020. These low-income people will be unable to afford the costs of a serious disease. Since the founding of the People’s Republic of China, the goal of health programs has been to provide care to every member of the population and to make maximum use of limited healthcare personnel, equipment, and financial resources. The emphasis has been on preventive rather than curative medicine on the premise that preventive medicine is “active” while curative medicine is “passive.” The healthcare system has dramatically improved the health of the Chinese people, as reflected by the remarkable increase in average life expectancy from about 32 years in 1950 to 69 years by the 1980s. After 1949, the Ministry of Public Health was responsible for all healthcare activities and established and supervised all aspects of health policy. Along with a system of national and local facilities, the ministry regulated a network of industrial and state enterprise hospitals and other facilities covering the health needs of workers. In 1981, this network provided approximately 25 percent of the country’s total health services, providing care in both rural and urban areas through a three-tiered system. In rural areas, the first tier was primitive, with doctors working out of village medical centers. They provided preventive and primary-care services, with an average of two doctors per 1,000 individuals. The second tier includes township health centers, which functioned primarily as outpatient clinics for about 10,000 to 30,000 individuals each. These centers had between 10 and 30 beds each, and the most qualified members of the staff were assistant doctors. These two lower-level tiers made up the “rural collective health system” that provided most of the country’s medical care. Only the most seriously ill patients
were referred to the third and final tier, the county hospitals, which served 200,000 to 600,000 individuals each and were staffed by senior doctors who held degrees from five-year medical schools. Healthcare in urban areas was provided by paramedical personnel assigned to factories and neighborhood health stations. If more professional care was necessary the patient was sent to a district hospital, and the most serious cases were handled by municipal hospitals. To ensure a higher level of care, a number of state enterprises and government agencies sent their employees directly to district or municipal hospitals, circumventing the lower-level healthcare. The 1950s saw a shift in health policy to an emphasis on preventive treatment. At that time the Communist party began to mobilize the population to engage in mass “patriotic health campaigns” aimed at promoting general improvements in environmental sanitation and hygiene and attacking certain diseases. One of the best examples of this approach was the mass assault on the “four pests”—rats, sparrows, flies, and mosquitoes. Special efforts were aimed at improving water quality through such measures as deep-well construction and human-waste treatment. Only in larger cities had human waste been centrally disposed. In the countryside, where “night soil” has always been collected and applied to the fields as fertilizer, it was a major source of disease. Since the 1950s, rudimentary treatments such as storage in pits, composting, and chemical treatments have been implemented. As a result of these preventive efforts, epidemic diseases such as cholera, plague, typhoid, and scarlet fever have been virtually eliminated. The mass mobilization approach proved particularly successful in the fight against syphilis, which was reportedly eradicated by the 1960s. The incidence of other infectious and parasitic diseases was reduced and controlled. Despite these positive gains, relaxation of certain sanitation and anti-epidemic programs since the 1960s has resulted in some increased incidence of disease. In the early 1980s, the persistence of such diseases as hookworm and schistosomiasis reflected continuing deficiencies in human-waste treatment. Tuberculosis, a major health hazard in 1949, remained a problem to some extent in the 1980s, as did hepatitis, malaria, and dysentery. By the mid-1980s, China recognized acquired immunodeficiency syndrome (AIDS) as a
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serious health threat, but remained relatively unaffected by the disease in comparison to other parts of the world. Still, following a 1987 regional World Health Organization meeting, the Chinese government announced it would join the global fight against AIDS, which involved quarantine inspection of people entering China from abroad, medical supervision of people vulnerable to AIDS, and the establishment of AIDS laboratories in coastal cities. In the mid-1980s, the leading causes of death in China were similar to those in the industrialized world: cancer, cerebrovascular disease, and heart disease. Some of the more prevalent forms of fatal cancers included cancer of the stomach, esophagus, liver, lung, and colon-rectum. The frequency of these diseases was greater for men than for women, and the number of lung cancer deaths was much greater in higher income areas. The degree of risk for different kinds of cancers varied widely by region. For example, nasopharyngeal cancer was found primarily in south China, while the incidence of esophageal cancer was higher in the north. To address concerns over health, the Chinese greatly increased the number and quality of healthcare personnel, although serious shortages continued to exist. Efforts were also made to improve and expand medical facilities. The overall number of hospitals and hospital beds has increased significantly in the last several decades, as has the number of specialized hospitals and scientific research institutions. By the 1990s, the availability and quality of healthcare in China still varied widely from city to countryside. According to census data, in rural areas the crude death rate was higher than in urban areas, and life expectancy was lower. The number of senior physicians per 1,000 population was about 10 times greater in urban areas than in rural communities, and state expenditure on medical care per capita was greater in urban areas than in rural areas. There were also about twice as many hospital beds in urban areas as in rural areas. Eventually economic reforms caused a fundamental transformation of rural healthcare. The decollectivization of agriculture resulted in a decreased desire on the part of rural populations to support the collective welfare system, of which healthcare was a part. This shift entailed a number of important consequences for rural healthcare. The lack of financial
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The Chinese pharmacopoeia includes more than 500 examples of crude drugs from plants and 400 traditional medicines.
resources for the cooperatives resulted in a decrease in the number of first tier doctors, which meant that health education and primary care suffered and that in some villages sanitation and water supplies were checked less frequently. At the same time, the failure of the cooperative healthcare systems limited the funds available for continuing education for first tier doctors, thereby hindering their ability to provide adequate preventive and curative services. The costs of medical treatment increased, making it difficult for some patients to obtain necessary medical attention. If the patients could not pay for services received, then the financial responsibility fell on the hospitals and health centers, in some cases creating large debts. Consequently, in the post-Mao era of modernization, rural areas were forced to adapt to a changing healthcare environment. Many first tier doctors went into private practice, operating on a fee basis and charging for medication. Soon, farmers demanded better medical services as their incomes increased, bypassing the first-tier doctors and going straight to health centers or county hospitals. A number of firsttier doctors left the medical profession after discovering that they could earn a better living from farming, and they were not replaced. The leaders of local healthcare systems also found farming to be more lucrative than their salaried positions, and many of them left their jobs. Many of the cooperative medical programs collapsed. Farmers in some areas estab-
lished voluntary health insurance programs but had difficulty organizing and administering them. Although the practice of traditional Chinese medicine was strongly promoted by the Chinese leadership and remains a major component of healthcare, Western medicine gained increasing acceptance from the 1970s through the beginning of the 21st century. The number of physicians and pharmacists trained in Western medicine reportedly increased, as did the number of physicians’ assistants trained in Western medicine. The goal of China’s medical professionals remains to synthesize the best elements of traditional and Western approaches, though in practice this combination has not always worked smoothly. In many respects, physicians trained in traditional medicine and those trained in Western medicine constitute separate groups with different interests. In general, physicians trained in Western medicine have been somewhat reluctant to accept traditional practices that they consider unscientific, and traditional practitioners have sought to preserve authority in their own sphere. Although Chinese medical schools that provided training in Western medicine also provided some instruction in traditional medicine, relatively few physicians emerged in the last few decades who were regarded as competent in both areas. In addition, the manner in which traditional and Western treatment methods were combined and integrated in the major hospitals varied greatly. In most urban hospitals, the pattern seemed to be to establish separate departments for traditional and Western treatment. In the rural hospitals, however, traditional medicine received greater emphasis. Traditional medicine depends on herbal treatments, acupuncture, acupressure, moxibustion (the burning of herbs over acupuncture points), and “cupping” of skin with heated bamboo. Because they have somewhat milder side effects, these approaches are believed to be most effective in treating minor and chronic diseases. Traditional treatments may be used for more serious conditions as well, particularly for acute abdominal conditions such as appendicitis, pancreatitis, and gallstones, and sometimes traditional treatments are used in combination with Western treatments. Although healthcare in China had developed in very positive ways by the mid-1980s, it aggravated the problems brought on by overpopulation. In 1987, China was faced with a population four times that of
the United States and over three times that of the Soviet Union. Efforts to distribute the population over a larger portion of the country failed because only the minority nationalities seemed able to thrive in the mountainous or desert-covered frontiers. Birth control programs implemented in the 1970s succeeded in reducing the birth rate, but by the turn of the 21st century, China’s population had surpassed the 1.2 billion mark, putting still greater pressure on the land and resources of the nation. In the modern era, the mood in China is one of change, although not the rapid change that is needed. China has fallen behind the West and is working to take up what it feels is its rightful position on the world stage. The effort to change and modernize is reflected in healthcare as well as in business and industry. For 50 years, the Communist government took care of the health needs of the country, dictating what was necessary and the manner in which resources were allocated. The central, provincial, and local governments funded hospitals, and medical care was provided at either no charge or very little charge to patients. Now that China has moved into a more capitalistic, entrepreneurial era, hospitals have been told that they have to finance some of their own costs. This has proved to be a difficult process for hospitals and for patients. Patients are now being asked to pay for some of their care and there is currently no system of private health insurance, although a number of organizations are looking to start such programs. Probably the most immediate problem in China is the almost total absence of primary care. Even in cities, there are few independent doctor’s offices or neighborhood clinics, so individuals are forced by necessity to go to the hospital for every healthcare need. Because there is little in the way of appointment systems, there is routinely a great deal of crowding and general confusion. An enormous amount of resolve and money would be needed to correct this problem in a country with China’s vast population. Hospital structures are also vastly different from place to place. Large cities like Beijing are well served with both general and specialist hospitals. Specialist hospitals, which are equivalent to tertiary care referral centers in the West, have excellent equipment and technology, and routinely perform cardiac surgery, angioplasty, and transplant surgery. In many rural areas, there is a structured system of local hospitals
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with increasing levels of expertise. However, there are areas of extreme poverty where the level of care leaves much to be desired. In the provinces farthest from Beijing, hospitals have little in the way of modern equipment or even modern plumbing. In general, doctors and nurses are poorly paid, and their level of training varies greatly. Training for doctors ranges from a two-year course to programs that are similar to those offered by Western medical schools. Specialists are generally well trained, but there is no national body that sets standards and assesses competency, such as the American Boards or a Royal College. Although doctors and nurses have social status similar to their counterparts in the West, many of the younger doctors are impatient with the very slow system of promotion. Moving from city to city, or even from hospital to hospital, is rarely an option, in part because such mobility has not been a traditional feature of Chinese life. Despite the absence of an official private healthcare system, patients can pay an additional amount of money to see a physician of their choice, or see one at a more convenient time, or receive individualized care. Some of these payments are official and are set by the hospital, but other payments are of the unofficial variety. The newly affluent Chinese are demanding a better level of service in all areas of life, including healthcare, and hospitals are responding to their demands by building units with comfortable private rooms and special nurses. See also: Healthcare, Asia and Oceania. BIBLIOGRAPHY. Gerald Bloom, Shenglan Tang, and Tang
Shenglan, eds., Health Care Transition In Urban China (Ashgate Publishing, 2004); Wong Chak-kie, China’s Urban Health Care Reform: From State Protection to Individual Responsibility (Lexington Books, 2005); Country Studies, www.countrystudies.us (cited October 2006); Howard W. French, “Wealth Grows, but Health Care Withers in China,” New York Times (January 14, 2006); Yuanli Lui, “China’s Public Health Care System: Facing the Challenges,” Bulletin of the World Health Organization (v.82/7, July 2004); Michael J. Moreton, “Healthcare in China,” www.medhunters.com (cited October 2006). Ben Wynne, Ph.D. Gainesville State College
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Chinese Medicine, Traditional
Chinese Medicine, Traditional Traditional Chinese medicine (TCM), a unique medical system, is gaining popularity worldwide for health promotion and adjuvant therapy. Emphasizing one’s internal and external harmony with oneself and the universe, TCM has been used to diagnose, treat, and prevent illnesses. TCM treatment focuses on strengthening the patient’s entire bodily system and restoring his or her inner balance. Although TCM is much more appropriate to disease prevention and the treatment of chronic diseases, it is crucial to consider certain fundamental issues, such as source materials, standardization, biological assays, diagnosis, and clinical studies. More studies are required to establish the effectiveness, safety, cost-effectiveness, and mechanism of action of TCM. The earliest written proof of TCM’s exceptional historical development is more than 2,000 years old. Various diseases and their classification, treatment, drug preparations, and applications were recorded and refined over many centuries by TCM practitioners. Since the 19th century, TCM has become a mainstream alternative medicine practiced all over the world. Currently, TCM continues as a distinct branch of modern medical practice. Influenced by Taoism, Buddhism, and Neo-Confucianism, the philosophical frameworks of TCM theory include yin-yang (two opposites are in constant motion), the five elements (earth, wood, water, metal, and fire), the human body meridian system, zang fu theory, and more. The general principles of TCM emphasize that humans are part of the universe and cannot be separated from the universal process of change, that optimum health results from living harmoniously, and that a holistic approach is to be used when addressing imbalances. In TCM, the body’s internal organs (“five viscera,” “six bowels,” and “extraordinary organs”)—not entirely equal to those of modern anatomy—are not thought of as individual structures but as complex networks. Qi, a basic component of the body, is the energy that is expressed externally through the meridian system. Health is seen as a harmonious equilibrium between the yin and yang, the five elements, the internal environment, other external conditions, and the seven emotions (joy, sorrow, anger, worry, panic, anxiety, and fear). Disease is regarded as
symptomatic of the patient’s bodily dysfunction and inner disharmony. The goal of TCM treatments is to assist the body to regain balance and achieve homeostasis, instead of tackling only the physical manifestations of the illness. The yin-yang and five elements theories are the major guideline for clinical diagnosis and treatment. By observing, listening, smelling, and pulse reading, as well as inquiring about the patient’s family relations, work, and emotions, TCM practitioners make a comprehensive, in-depth diagnosis of the total wellbeing of the patient. The body, mind, and spirit are viewed as one system. TCM practices include acupuncture and acupressure, moxibustion (burning an herb near the skin), herbal medicine, nutrition (food therapy), Chinese massage therapy (tui na), and exercise (e.g., tai chi, qi gong, and other meditation exercises). Herbal medicine and acupuncture have been the primary methods of modern TCM treatment, while other methods such as massage, qi gong, or food therapy play a secondary role. Herbal medicine acts on zang fu organs internally. Acupuncture is accomplished by stimulating certain areas of the external body. Qi gong tries to restore the orderly information flow inside the network through the regulation of qi. TCM is different from the modern drugs that have been successful in the treatment of acute conditions such as infectious diseases; the approach of TCM is much more appropriate to disease prevention and the treatment of chronic diseases without an unacceptably high level of collateral damage (e.g., pain relief, emotional care, and optimal wellness care). TCM is also known to be particularly helpful for various diseases and ailments, such as obesity, diabetes and its complications, high cholesterol, male and female fertility disorders, Alzheimer’s disease, digestive disorders, allergies, sinusitis, addictions, menopausal symptoms, osteoporosis, arthritis, infections, and sleep disorders. Many people are concerned about TCM because of its unscientific understanding of the human body and the nature of disease and its treatment. The efficacy of most previous TCM therapies has not been found through a sufficiently large number of rigorous clinical trials, especially randomized control trials. Although the methodological quality of trials of TCM has been improving over the years, many
Chiropractic
problems remain, such as lack of blind design, small sample size, lack of long-term design, problems of measurement, and so forth. There is an urgent need for the quality of trials of TCM to be improved to establish the effectiveness, safety, cost-effectiveness, and mechanism of action of this mode of treatment. For instance, there is no scientific consensus on the effectiveness that acupuncture should have for some illnesses. Also, the efficacy of TCM’s herbal medicines is a characteristic of a complex mixture of chemical compounds present in the various herbs. Although some herbs have known active ingredients that are also used in Western pharmaceuticals, there are considerable controversies over the effectiveness and safety of these substances. In general, the basic mechanism of TCM in treating the body is still not clear. This is partly related to language and lack of scientific research. For instance, it is difficult to translate qi and yin and yang into scientific terms. However, some studies have been conducted to explore the mechanism of TCM, indicating, for example, that acupuncture may modulate neurotransmitters, cytokines, and neuropeptides through electrophysiological changes in the nervous system. In the Chinese pharmacopoeia, more than 500 examples of crude drugs from plants and 400 traditional medicines that are widely used all over the world are recorded. Herbal medicines have become a popular form of therapy because of their fewer side effects, better patient tolerance, relatively inexpensiveness, and acceptance due to long history of use. TCM represents a daunting challenge because of the natural variability of the individual herbs and the chemical complexity of the formulations. Very efficient and selective methods including extraction techniques are required for identification and quantitative analysis of the active compounds and drug standardization. Fingerprint analysis has now been accepted by the World Health Organization as a methodology for the assessment of herbal medicines. The approaches of validation of TCM would be based on a set of rigorous criteria, such as preparation, chemical standardization, biological assays, animal models, and clinical testing. The safety of TCM depends on the type of treatment. Compared to other medical interventions, acupressure and acupuncture are largely accepted as safe.
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Some Chinese herbal medicines may involve a risk of allergic reaction, toxic reactions, possible mutagenic effects, drug interactions, and drug contamination. Potential risk may also include the use of some toxic and carcinogenic compounds (e.g., arsenic, cinnabar). It is not clear how certain herbs or mixtures of herbs interact with other drugs. The integration between Chinese and Western medicine is ongoing. Further studies and clinical trials should explore exactly how TCM works and clarify its effectiveness, safety, and cost. SEE ALSO: Acupuncture; Alternative Medicine; China;
Herbal Medicine; Herbal Remedy; Herbalism; Herbalist.
BIBLIOGRAPHY. Giovanni Maciocia, The Foundations of
Chinese Medicine: A Comprehensive Text for Acupuncturists and Herbalists (Churchill Livingstone, 1989); David Molony and Ming Ming Pan Molony, The American Association of Oriental Medicine’s Complete Guide to Chinese Herbal Medicine (Berkeley Books, 1998); Nigel Wiseman and Andrew Ellis, The Fundamentals of Chinese Medicine (Paradigm Publications, 1995). Mao-Sheng Ran, M.D., Ph.D. University of Guam Siu-Man Ng, Ph.D. University of Hong Kong
Chiropractic Chiropractic is a complementary and alternative healthcare profession that is involved in diagnosing and treating medical problems by adjustments made to the spine and the musculoskeletal system, usually by way of affecting the nervous system to improve the wellbeing of patients. This is based on an understanding that some human body problems come from lack of a normal nerve function, which chiropractors help improve through manipulation and adjustments of body structures. It has been particularly useful in dealing with joint problems, with some medical professionals still querying its use for many other health problems. The history of chiropractic work began with Daniel David Palmer, an Iowa merchant who was able to treat a deaf janitor, Harvey Lillard, on September 18,
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Chlamydia Infections
1895. Lillard had a misaligned vertebra, which, when adjusted, helped cure his deafness. The word chiropractic was coined by Rev. Samuel Weed, who based it on the Greek words “done by hand.” Palmer’s technique was seen as a method of curing people of some ailments without the use of medicine, and led to the establishment of the Palmer School of Chiropractic (now the Palmer College of Chiropractic). Many doctors were critical of this, and Heinrich Mathey, a medical doctor in Davenport, Iowa, started a campaign against Palmer, who was convicted in 1906 of practicing medicine without license. This led B.J. Palmer, son of Daniel Palmer, to form the Universal Chiropractic Association (UCA) to protect members and cover their legal expenses. Gradually, some people came to see chiropractors as being extremely useful in dealing with specific problems. This led to the National Institute of Health meeting in 1975 where chiropractors, osteopaths, medical doctors, and researchers met for a conference on spinal manipulation. Until 1983, the American Medical Association regarded chiropractic as “an unscientific cult,” but lost a court case when a Chicago chiropractic, Chester A. Wilk, launched an antitrust suit against them. Nowadays, doctors of chiropractic are trained in accredited chiropractic colleges, and chiropractic is a recognized profession in more than 100 countries in the world. SEE ALSO: Alternative Medicine. BIBLIOGRAPHY. Nathaniel Altman, Everybody’s Guide to
Chiropractic Health Care (St. Martin’s Press, 1990); Scott Haldeman, ed., Principles and Practice of Chiropractic (Appleton & Lange, 1992); Dirk Tousley, The Chiropractic Handbook for Patients (White Dove, 1985). Justin Corfield Geelong Grammar School, Australia
Chlamydia Infections While curable, chlamydia infections have spread globally with considerable impact on public health. The most significant global health impact of chlamydia may be in the evidence suggesting that treatable bacte-
rial sexually transmitted infections such as chlamydia and gonorrhea facilitate heterosexual transmission of human immunodeficiency virus (HIV). There are several types of chlamydia bacteria, but the types with greatest impact on public health are Chlamydia trachomatis and Chlamydia pneumoniae. Transmission of Chlamydia trachomatis infections occurs through oral, vaginal, or anal contact with an infected person. Women may be at higher risk of infection because certain cells in the female cervix are very susceptible to this infection. Chlamydia infections may be completely asymptomatic in many people. This lack of symptoms or signs to prompt medical attention means that unaware carriers can easily transmit chlamydia infection. Chlamydia trachomatis also causes trachoma, a severe chronic inflammatory eye disease that is a leading cause of preventable blindness worldwide, and lymphogranuloma venereum, a sexually transmitted infection affecting lymph nodes in the pelvis. Women with symptoms of chlamydia infection in the cervix may experience pelvic pain, abnormal vaginal discharge, or pain with sexual activity. Men with chlamydia infection of the penis may have abnormal discharge from the penis or pain with urination. In developed countries, treatment of suspected or diagnosed chlamydia infection is typically with an antibiotic, usually doxycycline or azithromycin. Many areas of the developing world diagnose and treat people for chlamydia infections in the context of World Health Organization guidelines for syndromic management for sexually transmitted infections. In women, chlamydia infection of the cervix may lead to pelvic inflammatory disease (PID), which usually involves infection of the fallopian tubes. PID can cause tubal scars and blockages that may prevent fertilization of an egg. Scarring associated with PID appears to be one of the major causes of infertility in the world. In addition, scarring may lead to pregnancy implantation in the fallopian tube (ectopic pregnancy). In men, chlamydia may spread to the epididymis, causing inflammation of this reproductive area (epididymitis), and leading to testicular pain, swelling, and infertility in some cases. It is possible for a pregnant woman to pass chlamydia infection to a baby, leading to eye infection or pneumonia. Condom use reduces the risk of sexual transmission of chlamydia infection. Eradication strategies vary in dif-
Cholera
ferent areas of the world. Some screening and treatment strategies have focused on screening people who present to their healthcare provider for routine care, while others focus on approaching and screening categories of individuals at highest risk of carrying infection. Chlamydia pneumoniae causes respiratory infection in humans, commonly children. Manifestations of infection may include pneumonia, sore throat, and laryngitis, among others. Like infections with Chlamydia trachomatis, Chlamydia pneumoniae infections often have no or mild symptoms. Transmission occurs through passing infected respiratory tract secretions. It is difficult to characterize the global impact of these infections due to problems in diagnosis and distinguishing it from other types of respiratory infection. Chlamydia psittaci rarely causes infection in humans. Symptoms may include fever, chills, headache, muscle aches, and cough. Infection occurs through breathing in secretions from infected, often asymptomatic, birds, usually pet birds and poultry. SEE ALSO: Bacterial Infections; Sexually Transmitted Dis-
eases; Trachoma.
BIBLIOGRAPHY. Centers for Disease Control and Preven-
tion, www.cdc.gov. (cited February 2007); Gale Reference Team, “Blinding Trachoma: Progress towards Global Elimination by 2020,” UN Chronicle (v.43/1, 2006). Lisa Noguchi Pittsburgh Medical Center
Cholera Cholera is an acute intestinal illness caused by the toxigenic bacterium Vibrio cholerae. While most infected individuals have no or mild to moderate symptoms, 5 percent have severe disease. Severe infection is characterized by large volumes of watery diarrhea and vomiting. Profuse amounts of diarrhea can lead to dehydration, metabolic disturbances, hypovolemic shock, and coma. Without appropriate fluid replacement, severe cholera can lead to death within hours. Without treatment, a cholera outbreak in a community may lead to fatality rates approaching 50 percent.
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V. cholerae is a gram-negative, curved, motile bacillus. While humans are the only known hosts, V. cholerae can exist in aquatic environments. Infection is generally via contaminated water and less commonly food. Once ingested, the bacterium produces an enterotoxin that activates the adenylate cyclase enzyme on the mucosal epithelium of the intestine. Activation of the enzyme opens ion channels and allows ions to flow into the intestinal lumen. Subsequently, massive amounts of water may be osmotically drawn into the intestine leading to dehydration and circulatory shock. Treatment for severe cholera consists of aggressive rehydration therapy to replace lost water and correct electrolyte imbalances. The World Health Organization (WHO) and the United Nations Children’s Fund (UNICEF) provide standardized sachets to be mixed with water to produce oral rehydration solution (ORS). ORS uses sodium-coupled glucose co-transport to stimulate resorption of salt and water. Therapy is given orally unless the patient is in shock or otherwise unable to take fluids by mouth, in which case they are given intravenously. In situations in which WHO/UNICEF ORS is not available, a rice- or cerealbased solution may be used. In severe cases, antimicrobial therapy may reduce the volume and duration of diarrhea and the period of vibrio excretion. There is no effective vaccine against cholera. Originally endemic to the Indian subcontinent, there have been seven global cholera pandemics and multiple epidemics over the past 200 years. In 1854, in one of the most important events in the history of public health, John Snow removed the handle on the Broad Street water pump in London and proved that cholera was transmitted via contaminated water. Due to improved sanitation, cholera no longer poses a significant risk in the developed world. However, in 2004, the WHO reported over 100,000 cases of cholera causing over 2,300 deaths in a total of 56 countries and estimates that this represents only 5 to 10 percent of the true burden of disease. SEE ALSO: Bacterial Infections; Diarrhea; Epidemic. BIBLIOGRAPHY. Centers for Disease Control, “Cholera”,
www.cdc.gov (cited May 2006); World Health Organization, “Cholera”, www.who.int (cited May 2006).
Shaun K. Morris, M.D., MPH Independent Scholar
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Cholesterol Cholesterol comes from and is needed to produce the cell membranes of living tissue. It does not dissolve in blood, and is a precursor to certain steroids such as cortisol, aldosterone, and vitamin D. A person’s cholesterol level will go up when he or she eats a high-fat diet, but a person can also have an intrinsic level of cholesterol that is genetically determined. Cholesterol levels rise when the weather is cold and increase between the ages of 20 and 60. High cholesterol levels increase the risk of cerebrovascular and cardiovascular problems; disease risk increases in proportion to the cholesterol level. Low cholesterol levels are rare and, when seen, are associated with depression and certain types of cancer. In physically active individuals, the risk of cholesterol depositing in the lining of arteries decreases. There are no symptoms of high cholesterol levels. Diagnosis is made with the aid of laboratory testing, and simple tests will provide one number for the total cholesterol level. The body will bind cholesterol to lipoproteins (low density, triglycerides, or high density) that circulate in the bloodstream. Cholesterol bound to high-density lipoproteins will not deposit cholesterol on the arterial lining; however, cholesterol attached to low-density lipoproteins, or triglycerides, will. SEE ALSO: Arteriosclerosis; Coronary Disease; Heart At-
tack; Heart Diseases (General); Stroke.
BIBLIOGRAPHY. D. John Betteridge, ed., Lipids and Vascu-
lar Disease (Informa Healthcare, 2000); Jean P. Kovala, ed., Cholesterol in Atherosclerosis and Coronary Heart Disease (Nova Biomedical Books, 2005). Tyler Cymet, D.O. Johns Hopkins School of Medicine
Chromosome A chromosome is a microscopic and threadlike part of a cell that carries within it hereditary information in the form of genes. With every species having a characteristic number of chromosomes, with species that reproduce asexually, the chromosome number remains
the same in all the cells of that organism. By contrast, in organisms that reproduce sexually, the number of chromosomes in the body cells is diploid, that is, chromosomes are found in pairs. During fertilization, two gametes combine to produce a zygote, a single cell, which has a diploid set of chromosomes. In addition, with organisms that have separate sexes, there are two major types of chromosomes: sex chromosomes and autosomes. The former are involved in determining whether the organism is male or female, and the latter deal with the inheritance of other characteristics. The first identification of chromosomes was in plants and was made by the Swiss botanist Karl Willem von Nägeli (1817–1891) in 1842. Next, the Belgian scientist Edouard van Beneden (1846–1910) identified chromosomes in ascaris worms. Chromosomes were described in detail by the German anatomist Walther Flemming (1843–1905) and the name was coined by another German anatomist, Heinrich Wilhelm Gottfried von Waldeyer Hartz (1836–1921). The British biologist and geneticist Cyril D. Darlington (1903–1981) discovered the chromosomal crossover and its importance in evolution. SEE ALSO: Cytogenetics; Genetic Code; Genetic Disor-
ders; Genetics.
BIBLIOGRAPHY. Oren Solomon Harman, The Man Who
Invented the Chromosome: The Life of Cyril Darlington (Harvard University Press, 2004); Teimuraz Lezhava, Human Chromosomes and Aging: From 80 to 114 Years (Nova Biomedical, 2006); Ram J. Singh and Prem P. Jauhar, eds., Genetic Resources, Chromosome Engineering and Crop Development (CRC Press, 2005). Justin Corfield Geelong Grammar School, Australia
Chronic Fatigue Syndrome Chronic fatigue syndrome (CFS) is a disorder consisting of disabling fatigue lasting more than six months and is associated with sleep disturbances, musculoskeletal pain, and difficulties with concentration and short-term memory. Ultimately, the diagnosis can be confirmed when other disorders with coexisting fa-
tigue are ruled out: hypothyroidism, hepatitis, cancer, alcohol or drug abuse within the past two years, sleep apnea, narcolepsy, iatrogenic effects of current medications, schizophrenia, psychotic disorders, severe obesity, dementia, anorexia nervosa, and bulimia. A comprehensive history and thorough physical and mental status exams should be followed by a minimum battery of laboratory tests, which include the following: urinalysis including complete blood count with differential; blood tests for protein, albumin, globulin, alkaline phosphatase, calcium, phosphorus, electrolytes, urea nitrogen, creatinine, glucose, alanine aminotransferase, and thyroid stimulating hormone. If doubts remain, one might also consider an antinuclear antibody titer to rule out a connective tissue disease and a Lyme Western blot test. There are no specific physical findings. No other laboratory tests are of diagnostic value, specifically neuroimaging tests such as magnetic resonance imaging (MRI), positron-emission tomography (PET) scans, radio nuclide scans, and various immunologic tests are not diagnostic. Serologic tests for Epstein-Barr, retro viruses, herpes virus 6, enteroviruses, Candida albicans, and so forth, neither confirm nor rule out CFS. Diseases that may often coexist with CFS are fibromyalgia, anxiety, nonpsychotic depression, multiple chemical sensitivity disorder, inadequately treated hypothyroidism, asthma, multiple sclerosis, and multiple pharmaceutical drug usage. The essential requirements for diagnosing CFS are 1.) chronic severe mental and physical fatigue lasting more than six months; 2.) exclusion of any known medical disease causing fatigue; and 3.) exclusion of any major psychiatric disorder. Of particular importance is the fact that 77 percent of patients with confirmed fibromyalgia, 64 percent of those with temporomandibular joint syndrome, and 30 percent of those with multiple chemical sensitivities clearly fulfill the criteria for codiagnosing CFS. Additionally, 22 out of 23 patients with CFS exhibited significant hypotension when placed on a tilt table at only 70 degrees, suggesting dysautonomia of the sympathetic nervous system. Similarly, most of these patients have marked increase in pulse rate when they stand suddenly. They also virtually always have striking increases in 24-hour catecholamine production; deficient levels of intracellular magnesium; deficient levels of taurine (86 percent) and up to seven essential amino acids; abnormal blood levels of serotonin,
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norepinephrine, beta endorphin, cholinesterase, and/ or melatonin; low or deficient levels of DHEA (dehydroepiandrosterone); focal excess electrical activity in one area of the brain, usually right frontal cortex; inability to follow photostimulation; mild to moderate depression; and deficient levels of vitamin B6. All of these findings are present also in virtually all patients with chronic depression and fibromyalgia, suggesting at least a common pattern of dysfunction of the hypothalamic-pituitary-adrenal axis. This is compatible with Selye’s concept of maladaptation to excess stress. Thus, multiple and varying physical and emotional factors are likely to be responsible for the particular expression of the clinical disorder. It is valuable to recall that a similar syndrome throughout the 19th and early 20th century was called neurasthenia. Most physicians report little success in treating CFS. Antidepressants and various antianxiety drugs and cognitive behavioral therapy have been of no value. In our experience, the following have been effective in over 80 percent of patients with CFS: • intravenous solutions of 2 g of magnesium chloride, 100 mg of B6, 1 cc of B complex, 1 g of calcium chloride, 250 mg of dexpanthenol, 1,000 mcg of B12, in 500 cc intravenous solution, daily for two weeks; • 60 minutes of daily stimulation, transcranially, with the Liss Cranial Electrical Stimulator, Shealy Series; • 60 minutes of daily photostimulation at 1 to 7 Hz; • continuing with B complex 100 mg daily as well as magnesium lotion, 2 teaspoons on the skin twice daily and a progressive exercise program. SEE ALSO: Anxiety; Depression; Multiple Chemical Sensi-
tivity; Stress; Temporomandibular Joint Dysfunction; Thyroid Diseases. BIBLIOGRAPHY. Leslie A. Aaron, Mary M. Burke, and
Dedra Buchwald, “Overlapping Conditions among Patients with Chronic Fatigue Syndrome, Fibromyalgia, and Temporomandibular Disorder,” Archives of Internal Medicine (v.162/2 , 2000); Niloofar Afari and Dedra Buchwald, “Chronic Fatigue: A Review,” American Journal of Psychiatry (v.160, 2003); Mark A. Demitrack and Leslie L. Crofford, “Evidence for and Pathophysiologic Implications of Hypothalamic-Pituitary-Axis Dysregulation
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in Fibromyalgia and Chronic Fatigue Syndrome,” Annals of the New York Academy of Sciences (v.840, 1998); Keiji Fukuda, et al., “The Chronic Fatigue Syndrome: A Comprehensive Approach to Its Definition and Study,” Annals of Internal Medicine (v.121/12, 1994). C. Norman Shealy, M.D., Ph.D. Independent Scholar
Chronic Obstructive Pulmonary Disease (COPD) Chronic obstructive pulmonary disease (COPD) is a devastating disorder that causes a huge degree of human suffering throughout the world. COPD is currently the fourth leading cause of death in the United States and sixth leading cause of death globally. It is a major public health threat throughout the world and afflicts millions. COPD is a disease where airflow obstruction due to chronic bronchitis or emphysema makes breathing difficult. When COPD occurs, it decreases the ability of the lungs to take in oxygen and remove excess carbon dioxide. COPD is progressive and not fully reversible despite available treatments. COPD can be caused by chronic bronchitis, emphysema, small airways disease, or a combination. As COPD progresses, the smaller airways and alveoli within the walls of the lungs lose their innate elasticity and collapse. This closes some of the smaller air passages and narrows larger ones. Most of the air passageways fill with mucus, and as air continues to reach the alveoli when the lungs expand during breathing, it becomes trapped and cannot leave the lungs upon exhalation. This is a disease that reduces lung capacity. A main contributing factor to COPD is environmental exposure to inhaled toxins, smoking, and secondhand smoke. Chronic bronchitis is described as the presence of an ongoing productive cough for many months during a two-year period. Emphysema is an abnormal, permanent enlargement of the air spaces in the lungs with destruction of these cell walls that makes them no longer function. COPD is present only if chronic airflow obstruction occurs in the lungs; chronic bronchitis without chronic airflow obstruction is not included within COPD.
History In the early 19th century, the Scottish physician Charles Badham and the great French physician and inventor of the stethoscope René Laënnec made the classic description of chronic bronchitis and emphysema. Later that century, a British textbook described the familiar clinical picture of chronic bronchitis as an advanced disease with repeated bronchial infections that ended in right heart failure. At that time, the described disease caused more than 5 percent of all deaths. Their work and disease descriptions led to our understanding of what COPD is today. The 20th century brought many advances that aid in the efficient diagnosis, sufficient treatment, and overall reduced morbidity for those with COPD. Specifically, accurate X-ray technology, sputum tests positive for microflora, arterial blood gas values, cardiac monitoring (ECG), and lung capacity testing such as spirometry for observation of airflow obstruction all enable the physician to paint the picture of COPD and in turn properly treat the patient. Unfortunately, many of the above-mentioned diagnostic tools are not available where they are needed most: in developing nations. Areas that have big industry and poor market regulations and lack any smoking cessation treatments have more citizens exposed to terrible environmental conditions and COPD risk factors. The disability resulting from lack of diagnosis or poor treatment is significant and leads to death. Global Epidemiology In the United States, 12 to 16 million people currently suffer from COPD and about 10 to 13 million have chronic bronchitis. Approximately 1.5 to 2.3 million suffer from emphysema. In the past 25 years, new cases of COPD have increased by half. Further estimates gauge the prevalence (new cases/patients per a year) of chronic airflow obstruction in the United States at 8 to 17 percent for men and 10 to 19 percent for women. The most significant increase in prevalence has been a 30 percent jump among women in the past 10 years. Globally, information and recorded medical data are not always reliable, as areas with increased risk have poor health surveillance systems and treatment measures. However, most research concludes that international prevalence rates are higher because of the fact that over 1 billion people are exposed to cigarette smoke—a major risk factor for COPD.
Chronic Obstructive Pulmonary Disease (COPD)
A 2005 study by the Journal for European Epidemiology used a population-based format in Spain and determined the prevalence of COPD in individuals aged 40–69 years at 9.1 percent (78 percent were men). Furthermore, based on pooled data from a number of studies, global prevalence of COPD was 8 percent, chronic bronchitis was 6 percent, and emphysema 2 percent. Many spirometric tests have been performed throughout the world with direction from the Global Initiative for Obstructive Lung Disease (GOLD). Under these guidelines, it is estimated that roughly 10 percent of adults aged 40 years or older are living with COPD throughout the world. GOLD works ������ with doctors and public health officials throughout the world to raise awareness of COPD and to improve prevention and treatment. GOLD is also responsible for the development of evidence-based guidelines for treatment of those with COPD and works to improve the lives of people living with the disease. Risk Factors In the United States, the surgeon general concluded that cigarette smoking was a major risk factor for mortality from chronic bronchitis and emphysema in the mid-1960s. Continued studies at present draw a direct connection between cigarette smoking and lung capacity, reduced airflow, and COPD. Approximately 80 to 90 percent of the deaths from COPD are from cigarette smoking. These data can actually be expressed in pack-years (average number of packs of cigarettes smoked per day multiplied by the total number of years of smoking). This obvious dose–response relationship between decreased lung capacity and function and that of cigarette smoking is overwhelming in relation to COPD. The obvious relationship between cigarette smoking and COPD has aided in cessation programs and public awareness campaigns about the harms of smoking. In the past 15 to 20 years, many antismoking advocacy groups and state legislatures in the United States have been successful in reducing the number of new smokers, helping those who still smoke to quit, and limiting the reach of stealth marketing campaigns and near-invincible lobbying groups of large tobacco companies. However, most of the settlements with major tobacco companies apply to the developed world, leaving much of the third world open for exploitative
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measures by big tobacco companies. For example, in China and India, where smoking among children is at atrocious levels, regulation is poor and major tobacco companies are not legally bound to promote awareness programs or follow such strict regulations on their products. Such programs can be simple and effective, such as a mandatory cigarette package label stating that smoking causes COPD and many other diseases, limiting advertisements of smoking products, and limiting smoking indoors. Without some of these simple measures in place, citizens continue to smoke and to start smoking earlier, therefore developing the many health problems that arise from smoking. Indeed, many of those who will get COPD in their lifetime started to smoke at an early age and had little to no education about smoking’s effects on health. However, the Framework Convention on Tobacco Control (FCTC), a watershed piece of legislation, was adopted by the 192 member states of the World Health Organization (WHO) and entered into force in early 2005. The FCTC encourages governments to provide people with more information about the dangers of smoking and enact and enforce measures that help keep young people from starting to smoke. These new measures offer hope for the reduction in incidence of COPD but are difficult to enforce and many governments are slow to fully accept them. The FCTC continues to be implemented and challenged in many regions and markets throughout the world. Cigarettes are not the only risk factors for COPD, and occupational exposures to toxins and inhalants are also an important cause of COPD. This exposure could be something as simple as inhaling dust from work, asbestos from old buildings, air pollution, or secondhand smoke. Many occupations have a higher risk for COPD due to chronic exposure to an unhealthy environment. These environments include coal and gold mining, cotton and other textile manufacturing, workplaces containing vaporized paints and dyes, and a wide variety of other industrial occupational settings. The level of exposure to many pollutants is poorly regulated and poorly tabulated in the least developed nations, where occupational health and safety conditions may be abysmal. These areas have many workers at risk for COPD. It should be noted that although several specific occupational dusts and fumes are risk factors for COPD, the mag-
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nitude of these effects may be substantially less important than the effect of cigarette smoking. Ambient Air Pollution Environmental health begins with the air we breathe. Beijing, Mexico City, and Tokyo arguably suffer from some of the world’s worst air pollution. However, the relationship between air pollution and COPD is not completely proven. There are high rates throughout the developing world of women with COPD who report that they do not smoke. It is possible that indoor air pollution may be a potential contributor to their COPD. Indoor air pollution usually comes from a lack of ventilation that leads to a concentration of air pollution where people live, work, and sleep. Indoor air pollution sources can be as varied as carpeting and woodworking that emit formaldehyde gas, paints and metals that give off volatile organic compounds, dust from stoves and fireplaces that leaves remnant particles, and dust from fuels (coal, wood, natural gas, turf/peat, and dung). These indoor air pollutants may all contribute to COPD. In most populations, ambient air pollution is still a much less important risk factor for COPD than cigarette smoking. Recent research on passive or secondhand smoke has made clear the relation to COPD. Specifically, a mother smoking while pregnant causes exposure to the fetus and contributes to significant reductions in postnatal lung function and growth. Many of the details about passive smoke and how it affects pulmonary function in COPD are still under study. Treatment COPD is treatable, but there is no cure for the disease. Early diagnosis and treatment remain great tools against the disease, as the earlier it is caught, the faster it can be treated and the more lung capacity can be reserved. Of course, the best treatment is prevention and avoiding environmental risk factors such as smoking. Complete cessation of smoking can slow COPD progression. In North America, COPD diagnosis often occurs late, when patients exhibit major symptoms and are in their late 50s or 60s. At this point, lung function has significantly declined and quality of life has deteriorated. In the least developed nations, COPD diagnosis and treatment may never occur and many of those with emphysema and bronchitis may not have any access to medical care or treatment.
Most patients who are diagnosed early enough can stop smoking and begin to take measures to curb the disease. However, as the disease progresses, such medicines as bronchodilators that enlarge the area of the lungs to aid in air flow in and out may offer assistance, as will the delivery of oxygen therapy. Oxygen can be given on a long- or short-term basis. In late stages of COPD, many complications with breathing and heart failure can occur and, if not treated, can be fatal. The goal of treating COPD is to improve physical endurance and overcome the conditions that cause shortness of breath and limit the capacity for daily activities. These treatments can also include antibiotics if there is a bacterial infection causing bronchitis. Doctors who treat COPD are aiming at improving lung function, reducing time spent in hospital, minimizing disability, and delaying early death. SEE ALSO: Air Pollution; Asbestos/Asbestosis; Bronchitis;
Emphysema; Environmental Health; Environmental Tobacco Smoke (ETS); Industrial Health; Pollution; Respiratory Diseases; Smoking; Smoking and Pregnancy; Smoking and Youth; Smoking Cessation. BIBLIOGRAPHY. R. Carter, B. Nicotra, and J. V. Tucker,
Courage and Information for Life with Chronic Obstructive Pulmonary Disease (New Technology Publishing, 1999); Trevor Hansel and Peter Barnes, Recent Advances in the Pathophysiology of COPD: Progress in Inflammation Research (Basel, 2004); Neil Schachter, Life and Breath: Preventing, Treating and Reversing Chronic Obstructive Pulmonary Disease (Broadway, 2003). John Michael Quinn V University of Illinois at Chicago
Chronology of Global Health Populations have always been concerned with the health of their members and the health of other populations with whom they interact. Although specific problems change with evolving socio-environmental and political contexts, several concerns persist: the control of transmissible diseases; the control of the physical environment, including sanitation; the provision of sufficient, clean water and nutritious food;
the provision of medical care and the specific role of primary care; the relief of destitution and destruction, including wars, famines, and poverty; the economics of who pays for healthcare; and the politics of setting health policies. Accounts of plagues and other health issues in historical texts parallel many current public health concerns. Measures to provide clean water and remove waste are apparent in ancient structures of India, Crete, Egypt, and Peru, among others. Hippocrates’ treatise, Air, Water and Places, guided Greek colonizers in choosing salubrious settlement sites and establishing physician practices. The Romans built aqueducts as well as public medical services. After the fall of Rome, health infrastructure and administration decayed in western Europe but endured in the Byzantine Empire. In medieval Europe, extralocal health concerns focused on routes of trade, pilgrimages, and the Crusades. Fortified cities fostered crowding and poor sanitation, and monasteries featured “infectoriums.” Early transborder epidemics (fueled by expanded travel, war, and incarceration) included leprosy, which was ignited by returning crusaders, and the Black Plague, which was carried by traders through central Asia, India, and the Middle East to European ports in 1348. In the 1500s, ships arriving in Venice were quarantined, following earlier practices of isolating lepers. Exploring Europeans introduced diseases such as measles, malaria, and smallpox to the New World. In turn, they were exposed to “tropical” infections including cholera and sleeping sickness. In the 1700s, centralizing European powers viewed a healthy population as necessary for “opulence and power.” They focused locally, establishing hospitals, dispensaries, and asylums, along with paved roads, water supplies, and sanitation. Variolation came to Europe around 1700 via Constantinople; in 1796, Edward Jenner developed the cowpox vaccination, commencing mass health campaigns. The Industrial Revolution increased movement and contact of people and germs through urbanization, improved roads and canals, and faster modes of communication. These changes elucidated the link between poverty and disease, rendering occupational health and aid to the poor a social focal point. Edwin Chadwick amended England’s Poor Laws in 1834 to include new ideas on administering aid, sanitation, community health education, and disease prevention.
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The year 1848 witnessed a cholera epidemic and the introduction of England’s Public Health Act and General Board of Health (which met with resistance) and France’s public health administration. England’s Public Health Act (1875) established a medical officer in each district. U.S. Public Health and sanitation surveys were spurred by immigration and the subsequent crowding in the mid-19th century. Unified Germany established the Reich Health Office in 1873. Health considerations outside of Europe and North America remained largely the purview of religious organizations. Disease outbreaks sparked international conversations on disease. In 1849 J. Snow and W. Budd simultaneously proposed that cholera spread through the water supply, but disagreement about contagion, medical licensure, and state responsibility curtailed early control efforts. In 1851, the First International Sanitary Conference convened in Paris, but the charter drafted at this conference was weak. Agreement on modes of contagion, further cholera epidemics, and the opening of the Suez Canal in 1869 allowed for real international progress. The work of L. Pasteur, J. Lister, J. Henle, O.W. Holmes, I. Semmelweis, F. Cohn, and R. Koch, among others, contributed to germ theory and its clinical applications. Discovering animal vectors, including Ronald Ross’s isolation of mosquitoes as the malaria vector, helped curb transmission. The New York City Health Department first applied bacteriology to public health via a system of public health laboratories. Urban sanitation, personal hygiene improvements, and cotton underwear also worked to reduce infection spread. In some cases, imperial powers established colonial health services to maintain healthy troops, workers, and business prospects. The outbreak of wars at the end of the 19th century spotlighted public health. Armies required a supply of healthy men, in turn requiring reduced childhood mortality. Voluntary health organizations furnished new services and filled gaps left by specialized medicine. International health organizations coalesced, including the Pasteur Institutes, the Rockefeller Health Board (1913), the Pan American Sanitary Bureau (1902), and the League of Nations Health Board (1923). The London School of Hygiene and Tropical Medicine was established in 1899 to train doctors. Graduate programs in health education began in the United States in 1943. The Johns Hopkins School of
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Hygiene and Public Health established the first formal Department of International Health in 1961. After World War II, global health regulation became more centralized and organized. The new World Health Organization, the United Nations, and the International Financial Institutions focused on disease control for political and economic stability. The 1970s saw the launching of major global health programs including smallpox eradication (which was successful in 1981) and the United Nation Children’s Fund’s (UNICEF) Child Survival program. The coverage of basic health services was paramount in the 1970s and focused on simple technologies for health, such as oral rehydration solutions and vaccines, including the Salk polio vaccine. In 1978 the World Conference on Primary Health Care, in Alma-Ata (in the former Soviet Union), produced a broad definition of health and the declaration of Health for All by 2000. However, the broad and horizontal goals of community primary healthcare, based on China’s model, gave way to disease-specific, vertical public health programming, and the siloing of linked public health efforts. Concerns about overpopulation in the 1970s led to population control programming, including family planning, small-family policies, and both voluntary and forced sterilization. The 1994 International Conference on Population and Development (ICPD) in Cairo ushered in a shift toward “reproductive health,” followed by the Safe Motherhood Initiative. Efforts continue to broaden the focus to women in general, not just as mothers, and to health across the lifespan. In the 1980s, the World Bank’s Structural Adjustment Programs (SAPs) streamlined public spending, translating into reduced government input into healthcare in developing countries. With the publication of the 1993 World Development Report, “Investing in Health,” the tenor in health economics shifted to justify healthcare with economic rationales. In contrast, many scholars continue to advocate for a rights-based approach to healthcare, following the Alma-Ata declaration. In 1981, human immunodeficiency virus (HIV) was identified and it has since killed over 25 million people. While antiretroviral therapies exist, the cost of drugs excludes a large number of the world’s poorest would-be patients—a number that continues to grow and create ever-more orphans. Institutes, multilateral organizations, nongovernmental organizations (NGOs), bilateral agencies, and
foundations have become important players in global health. These new actors work to balance old problems using novel strategies, such as Sector-Wide Approaches (SWAps) and donor harmonization. A major focus includes efficiency and equity trade-offs. New threats mount: the exacerbation of old infections and emergence of new ones, drug resistance, disease spread by air travel, environmental changes and global warming, chronic diseases, drug trafficking, and destructive and self-destructive violence. To face new and continuing challenges, interventions target behavioral, environmental, and structural issues, such as the Global Tobacco Treaty, workers’ rights, and mental health. SEE ALSO: Global Health Council; Global Health Ethics;
Healthcare, Africa; Healthcare, Asia and Oceania; Healthcare, Europe; Healthcare, South America; Healthcare, U.S. and Canada. BIBLIOGRAPHY. P. Basch, Textbook of International Health,
2nd ed. (Oxford University Press, 1999); G. Berlinguer, “Globalization and Global Health,” International Journal of Health Services (v.29/3, 1999); Centers for Disease Control and Prevention, www.cdc.gov (cited May 2007); M.H. Merson, R.E. Black, and A.J. Mills, International Public Health: Diseases, Programs, Systems and Policies, 2nd ed. (Jones and Bartlett, 2007); D. Porter, UN-HABITAT Annual Report (United Nations, 2006); Dorothy Porter, Health, Civilization, and the State: A History of Public Health from Ancient to Modern Times (Routledge, 1999); G. Rosen, History of Public Health (MD Publications, 1958); World Health Organization, “Framework Convention on Tobacco Control (WHO FCTC),” www.who.int/tobacco (cited May 2007); A. Zwi and D. Yach, “International Health in the 21st Century: Trends and Challenges,” Social Science & Medicine (v.54, 2002). Emma Sacks Columbia University Heather Lanthorn Independent Scholar
Circadian The term circadian literally means “around a day,” and is a descriptive word that indicates that an entity functions on an approximately 24-hour cycle. All living cells
have an inherent and endogenously active chronological system that helps them synchronize their physiology and behavior to cues from the environment. These circadian rhythms are highly conserved across species and are genetically programmed. Molecular and genetic evidence of circadian rhythms has been observed in species as varied as photosynthetic bacteria, fungi, plants, mice, and humans. It is hypothesized that the 24-hour period is not arbitrary but developed in accordance with the needs of the first primitive unicellular organisms to prevent DNA damage from sunlight approximately 2 billion years ago. Additionally, recognition of night and day would have helped primitive cells more efficiently demarcate appropriate periods for nitrogen fixation and photosynthesis. As an essential feature of cellular life, chronicity and the specific manner of splicing time may have developed in response and relation to the periodicity of the earth’s rotation around its axis. With natural environment cues of sunlight and sunset, human circadian rhythms occur at almost exactly 24-hour periods. However, when animals are placed in constant light or constant darkness, and with natural environmental cues absent, the endogenous circadian system is said to “free run.” Within these somewhat artificial conditions, circadian rhythms still function at periods of approximately 24 hours, although the exact free-running period varies from species to species. In humans, the free-running rhythm is 25 hours, and variation from person to person is no more than a few minutes. The endogenous circadian rhythm is independent from homeostatic mechanisms such as temperature control and does not change in different environmental temperatures. It would be a mistake to assume that just because circadian rhythms are under genetic control and are evolutionarily conserved that they are impervious to changes in the environment. In a free-running environment (such as having been awake all night in a hospital), a circadian rhythm can be reset by even brief contact with sunlight. Blue light seems to create the most powerful effect. This does not mean that the 24-hour period changes but that the phase (“day”/“night”) within that period can be subjectively reset. The extent and direction of the phase shift will vary depending on where one is in the 24-hour cycle (i.e., subjective “day” or “night,” the early or late night, etc.). For example, if one is in one’s subjective
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“day” phase, sunlight will not significantly change the phase one is in, but if one is shown sunlight in the late phase of “night,” a phase advance will occur and the internal clock will be reset via a projection directly from the retina to pacemaker cells in the hypothalamus. These are the foundations of the adaptive mechanisms underlying the phase delay and phase advancement that can occur when organisms are placed in nonsymmetric day and night environments. It should be noted that many nonphotic effectors of the internal clock (melatonin, leptin, opioids, etc.) exist as well. Circadian rhythmicity is a self-sustaining property that emerges at the level of the cell itself. Circadian rhythms are produced by the selective expression and regulation a variety of evolutionarily conserved “clock” genes (clock, Bmal1/Mop3, Per1, Per2, Per3, etc.) and their positive and negative transcriptional/ translational feedback loops. The regulation of these protein products produces cyclical variation in important intracellular molecules. In mammals, the superchiasmatic nucleus (SCN) of the hypothalamus, acting as “conductor” of a symphony of peripheral extrahypothalamic oscillators, is centrally important in producing circadian activity and behavior. Circadian rhythms are strongly innate and conserved mechanisms. No amount of environmental training is able to recreate circadian-dependent behavior in animals that have clock genes experimentally knocked out. As mentioned, free-running circadian activity exists without environmental cues. Circadian activity has been demonstrated to occur autonomously in some cells even when separated from their organismic milieu. Circadian Rhythms and Health The importance of endogenous circadian rhythms for health and human flourishing is immense. Circadian rhythms help us track time and prepare for environmental changes. Humans must know when to sleep and when to wake, and must coordinate this with the needs of their local environment. In many animals, mating is a seasonal event that must be calculated unconsciously by an estimation of a variable that exhibits seasonal variation: the length of the day, and its deviance or concordance with one’s internal clock. With humans, knowing when to harvest and when to plant crops may be achieved by other means. Yet,
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much of our internal biochemistry, including those factors that determine sexual behavior, immune function, and metabolism, exhibit cyclical time dependence. Hormones such as testosterone, insulin, cortisol, body temperature, and metabolic rate all fluctuate with the phase of the circadian clock. Also, attention, memory and motor tasks are better or worse performed in different circadian phases. A number of situations exist wherein human wellbeing can be challenged due to the imposition of modern environmental inventions that perturb the accuracy of the individual’s calculation of endogenous time. Examples include jet lag, shift work, and other artificial light and sleep-deprivation environments. SEE ALSO: Genetics; Knockout; Sleep Disorders. BIBLIOGRAPHY. A. Avivi, et al., “Biological Clock in Total
Darkness: The Clock/MOP3 Circadian System of the Blind Subterranean Mole Rat,” Proceedings of the National Academy of Sciences of the United States of America (v.98, 2001); D.M. Berson, “Strange Vision: Ganglion Cells as Circadian Photoreceptors,” Trends in Neurosciences (v.26, 2003); H. Oster, “The Genetic Basis of Circadian Behavior,” Genes, Brain, and Behavior (v.5/Suppl 2, 2006); S. Panda, et al., “Coordinated Transcription of Key Pathways in the Mouse by the Circadian Clock,” Cell (v.109, 2002); S.M. Reppert, “A Clockwork Explosion!” Neuron (v.21, 1998); M.H. Vitaterna, et al., “Mutagenesis and Mapping of a Mouse Gene, Clock, Essential for Circadian Behavior,” Science (v.264, 1994). Omar Sultan Haque Harvard University
Cirrhosis Cirrhosis is a clinical entity characterized by a spectrum of diffused hepatic pathologic features that underpin a number of characteristic clinical signs and symptoms. It represents an irreversible state of chronic liver failure resulting from a wide variety of chronic liver diseases. The word cirrhosis derives from the Greek scirrhus, which means “tawny” (the color of the orange or tawny surface of the liver seen at autopsy). The term was coined by René Laënnec in 1826, through his work in which he also discusses the
stethoscope. Chronic liver disease and cirrhosis are responsible for about 35,000 deaths per year in the United States, where it is the ninth leading cause of death, accounting for 1.2 percent of total deaths. The pathologic features that define cirrhosis are extensive fibrosis (deposition of the components of the extracellular matrix), along with regenerative, structurally abnormal nodules. They are a consequence of events such as destruction of liver cells (hepatocytes), collapse of the supporting fibrous network with ulterior deposition of connective tissue, distortion of the normal vascular architecture, and nodular regeneration of the remaining liver parenchyma. Hepatic fibrosis is the result of the activation of hepatic stellate cells (quiescent liver cells that store vitamin A) through the release of factors from hepatocytes and Kupffer cells (specialized liver cells of the immune system), thus producing collagen. These pathologic features imply the presence of irreversible chronic injury to the hepatic parenchyma. Cirrhosis can be classified using etiologic or morphologic criteria. However, it is more accurate to devise a classification by combining both types of criteria. The same pathological pattern can be caused by different types of injury, whereas the same type of injury may result in a variety of morphologic patterns. Thus, cirrhosis can be classified as alcoholic, cryptogenic and posthepatitic, biliary, cardiac, metabolic, inherited, and drug related. Alcoholic cirrhosis is a consequence of chronic alcohol consumption and is one of the most common types of cirrhosis in North America and many areas in western Europe and South America. Posthepatitic cirrhosis refers to the final stage of diverse types of chronic liver disease. Cryptogenic cirrhosis pertains to the cases where the etiology of cirrhosis is unknown (around 10 percent of all patients with cirrhosis). Biliary cirrhosis (either primary biliary cirrhosis or secondary biliary cirrhosis) is caused by the protracted obstruction of the biliary system. Cardiac cirrhosis is a consequence of severe right-sided congestive heart failure. Cirrhosis can also result from infectious diseases (e.g., brucellosis, toxoplasmosis, viral hepatitis), drugs and toxins (e.g., alcohol, amiodarone, oral contraceptives), inherited and metabolic disorders (e.g., α1antitrypsin deficiency, hemochromatosis, Wilson’s disease), and other causes (e.g., cystic fibrosis, nonalcoholic fatty liver disease, sarcoidosis). Hepatitis C has
replaced alcoholic liver disease as the main cause of cirrhosis, accounting for around 26 percent of cases, with alcoholic liver disease comprising 21 percent. The clinical manifestations of cirrhosis are often suggestive of the degree of liver damage and not of the liver disease causing it. While some patients are completely asymptomatic and have a reasonable life expectancy, others have severe symptoms and a short life expectancy. The clinical presentation of cirrhosis could involve either a late-stage complication such as bleeding from gastroesophageal varices (hemorrhage of the engorged vessels located near the inner surface of the gastroesophageal region) or encephalopathy (a spectrum of neuropsychiatric derangements that are not caused by brain disease), or be more subtle and comprise symptoms such as fatigue, muscle wasting, easy bruising, mild abdominal swelling, or a new onset of bilateral ankle edema. Signs of chronic liver dysfunction include reddening of skin on the palmar surface of the hands, Dupuytren’s contracture (a condition of the hands and fingers causing one or more fingers to bend into the palm), spider angiomata (an abnormal number of vessels near the surface of the skin), enlarged parotid and lacrimal glands, gynecomastia (benign enlargement of the male breast), testicular atrophy, impotence, loss of axillary and pubic hair, and clubbing (a deformity of the fingers and nails). Most cases of cirrhosis and chronic liver failure have a nonspecific presentation. Patients with advanced cirrhosis may be affected by complications such as portal hypertension (increased pressure in the main vein bringing blood to the liver from the digestive system) and its consequences (e.g., gastroesophageal varices and an enlarged spleen), ascites (fluid in the abdomen), hepatic encephalopathy, spontaneous bacterial peritonitis (an acute infection of the fluid in the abdomen), hepatorenal syndrome (kidney failure in patients with chronic liver disease, ascites, and portal hypertension), and liver cancer. The most serious complications are variceal bleeding, ascites, and hepatic encephalopathy. Patients with cirrhosis have an increased risk of developing liver cancer. Treatment modalities for cirrhosis involve prevention and addressing reversible causes such as chronic hepatitis, chronic alcohol abuse, hemochromatosis, and primary biliary cirrhosis. Furthermore, it also involves treating the manifestations and complications
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of cirrhosis and chronic liver failure. Some patients have indication for liver transplantation. SEE ALSO: Alcoholism; Hepatitis C; Liver Cancer; Liver
Diseases (General); Liver Transplantation.
BIBLIOGRAPHY. Mark R. Allee and Mary Zoe Baker, “Gy-
necomastia,” www.emedicine.com (cited April 2007); Samy A. Azer, “Esophageal Varices,” www.emedicine.com (cited April 2007); Jesus Carale and Sandeep Mukherjee, “Portal Hypertension,” www.emedicine.com (cited April 2007); “Dupuytren’s Contracture,” www.patient.co.uk (cited April 2007); A.H. Goroll and A.G. Mulley Jr,, Primary Care Medicine—Office Evaluation and, Management of the Adult Patient, 5th ed. (Lippincott Williams & Wilkins, 2005); Dennis L. Kasper, et al., Harrison’s Principles of Internal Medicine, 16th ed. (McGraw-Hill, 2005); “Palmar Erythema,” www. patient.co.uk (cited April 2007); “Spider Angioma,” www. nlm.nih.gov/medlineplus (cited April 2007); D. Warrell, et al., Oxford Textbook of Medicine, 4th ed. (Oxford University Press, 2004); David C. Wolf, “Cirrhosis,” www.emedicine.com (cited April 2007). Tiago Villanueva Centro Hospitalar de Lisboa-zona central
Cleft Lip and Palate Cleft lip and cleft palate are congenital deformities that occur in the womb. Cleft lip is an abnormal fissure during development that fails to close the lip and leaves an opening or openings at birth. Cleft palate is a fissure or opening at the roof of the mouth or palate. This opening forms a pathway between the mouth and nasal cavities and can cause speech impairment, infection, and breathing difficulty if not treated. Cleft palate may be one side of the roof of the mouth (unilateral), or both sides of the mouth (bilateral). The opening may be complete or incomplete. The causes are poorly understood but both genetic and environmental factors are at play. With access to more DNA diagnostics, clefts are considered to be more a part of a syndrome. Alcohol and tobacco use by the mother during pregnancy may also play a role. Almost all cases of cleft lip and cleft palate can be treated surgically, although in the developing world, many
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who are afflicted do not have access to this surgical treatment. Globally, cleft lip and cleft palate pose the largest danger from lack of treatment: dental caries, ear infections, and social stigma. Furthermore, feeding and suckling may be a major issue if not treated. In the past 20 years, many efforts have been made to record frequency of cleft lip and cleft palate globally, with a lack of results. Many countries have begun major research efforts to seek an accurate incidence and prevalence description as well as any possible genetic/environmental factors that may exist. One of the major goals is also to describe an international classification of cleft lip and cleft palate with help of the World Health Organization (WHO). There are many parts of the world where the diagnosis, classification, and record keeping of cleft lip and palate are inadequate or inconsistent. This hinders public health efforts to serve areas of greatest need. Specifically, parts of Africa, central Asia, eastern Europe, India, and the Middle East significantly lack resources and healthcare infrastructure to be able to offer solid data to the epidemiology of cleft lip and palate. It is understood that approximately 7,000 to 8,000 children are born with cleft lip or cleft palate each year in America. This makes cleft lip and palate one of the most common major birth defects in North America. Clefts occur more often in children of Asian, Latino, or Native American descent. It is also more common in males than in females to have cleft lip, while more common in females to have cleft palate. There are generally three different kinds of clefts: cleft lip without a cleft palate; cleft palate without a cleft lip; or cleft lip and cleft palate together. Bilateral cleft lip is a cleft in both sides of the lip. Complete bilateral cleft lip involves two wide gaps in the upper lip and an opening of the upper jaw. A cleft lip appears as a narrow opening or gap in the skin of the upper lip that extends all the way to the base of the nose. A cleft palate is an opening between the roof of the mouth and the nasal cavity. Some children have clefts that extend through both the front and rear part of the palates, while others have only a partial cleft. The specific classifications and severity of clefts are defined by the WHO. Diagnosis for cleft lip and palate are simple upon birth with visualization. Diagnostic imaging, such as ultrasound, is also effective while the mother is still pregnant. Surgery is the most common treatment.
The type of operation required depends on the severity and location of the cleft. Many times, multiple operations are performed as the child grows and develops. Ongoing treatments and therapies such as speech and language therapy as well as dental and orthodontic care must be provided for solid followup. Most of the above-mentioned treatments are lacking in the developing world. In the developing world, the prognosis of cleft lip and palate can be quite poor as the resources are lacking to properly treat it and offer secondary therapies for speech development and social interaction. However, where resources do exist, prognosis is quite good. Treatment may extend over several years and require multiple surgeries, depending upon extent of the cleft, but most children affected can have a normal appearance and normal speech, and are well adjusted to eating and drinking normally. SEE ALSO: Beals, Rodney K.; Birth Defects; Mouth Disor-
ders; Prenatal Care; Speech and Communication Disorders.
BIBLIOGRAPHY. L.A. Croen, et al., “Racial and Ethnic Vari-
ations in the Prevalence of Orofacial Clefts in California, 1983–1992,” American Journal of Medical Genetics (v.79, 1998); Diego F. Wyszynski, Cleft Lip and Palate: From Origin to Treatment (Oxford University Press, 2002). John Michael Quinn V University of Illinois at Chicago
Climacteric The term climacteric was used by the ancient Greeks to identify the critical years in a person’s life, and is commonly used by medical researchers and doctors to mark the menopausal period in women and the similar period in men’s lives. Astrologers in the ancient world in Europe used numerology and star patterns to ascertain when those times would affect individual people, often seeing lives in multiples of seven years, with a person’s 63rd year said to be the Grand Climacteric, an age that many men and women approached with care, as evidenced by comments made by the Roman emperor Augustus. Later, the Grand Climacteric was raised to the age of
Clinical Trial
81, again a multiple of seven. Shakespeare’s “Seven Ages of Man” reflects the importance of the number seven in numerology. The word comes from the Greek work klimakterikos, from klimakter for the step of a staircase, and first appeared in the English language in 1601, with its astrological purposes assigned in 1634, and more general application six years later. Nowadays, the medical use of the term climacteric is as a synonym for the female menopause, marking a major change in a woman’s life when the menstrual cycle ends. It is also used to refer to the corresponding time in the lives of men. The International Menopause Society uses the term in its charter, defining itself as “the society for the study of all aspects of the climacteric in men and women.” SEE ALSO: Menopause. BIBLIOGRAPHY. Richard Gates, After the Ball Is Over:
Men in Midlife (University of New England Press, 1994); Luigi Mastroianni Jr. and C. Alvin Paulsen, eds., Aging, Reproduction and the Climacteric (Plenum, 1986); Peter A. O’Connor, Understanding the Mid-Life Crisis (Sun Books, 1981); Elmer L. Sevringhaus, The Management of the Climacteric, Male or Female (C.C. Thomas, 1948).
Justin Corfield Geelong Grammar School, Australia
Clinical Trial A clinical trial is a study that uses human volunteers to answer a specific research question. An important epidemiological tool, clinical trials consist of two subtypes: observational trials and interventional trials. Observational trials consist of collecting data and inferring results after surveillance of a population in its natural environment. Interventional trials examine whether a new treatment is safe and effective in humans. A group of physicians, nurses, medical researchers, and other healthcare professionals oversee a clinical trial. They coordinate the study and the study participants, manage and interpret the results, and publish findings. People choose to participate
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in clinical trials for several reasons, including earlier access to new treatments and the advancement of medical research; however, they must meet the study’s specific inclusion criteria, which are characteristics that the study investigators determine a priori. Inclusion criteria can include age; the extent, or stage, of the disease; prior treatments, and others. In addition, exclusion criteria are determined to prohibit certain people who cannot participate in the clinical trial. Once the study participants have been selected, they must provide informed consent. This process consists of explaining the purpose, risks and benefits, duration, and any required procedures of the trial. After informed consent and the gathering of participants, the clinical trial can begin. Successful clinical trials incorporate frequent contact between the study participant and the research team as well as strict adherence to the study protocol, a detailed methodology on the execution of the study. During a clinical trial, the clinical research team will assess the participant’s baseline health, provide the intervention or treatment that is being studied, monitor the participant’s response to the intervention through laboratory tests or imaging, and record results. Sometimes, a clinical trial may find that the treatment is causing harm. The research team may choose to stop the clinical trial; however, if a treatment is shown to benefit the study participants, this signifies that the treatment may be ready for mass distribution. Clinical trials have four different phases. Phase I trials evaluate the safety of the new treatment, determine a safe dosage, and identify side effects in a small group of people (usually 20 to 100 people). Phase II trials are an expansion of Phase I trials and use 100 to 300 people to evaluate safety. Phase III trials confirm the effectiveness of the new treatment, further elucidate the safety profile of the treatment, including monitoring side effects, and compare the new treatment to ones already available. These trials usually consist of 1,000 to 3,000 people. Lastly, Phase IV trials occur after the treatment is on the market by monitoring the intervention’s safety. Funding for clinical trials comes from many sources. These include hospitals, medical schools, research foundations, pharmaceutical companies, and federal agencies, including the National Institutes of Health and the Centers for Disease Control and Prevention.
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See also: Case-Control Study; Centers for Disease Con-
trol and Prevention (CDC); Cohort Study; National Institutes of Health (NIH); Randomized Clinical Trial. BIBLIOGRAPHY. National Institutes of Health, “An Intro-
duction to Clinical Trials,” www.clinicaltrials.gov (cited October 2006).
Lindsay Kim Emory University School of Medicine
Clone Clone is a term with multiple usages in the biomedical sciences, referring both to a general concept in molecular genetics and to the application of this concept to whole organisms (particularly, but not exclusively, to higher animals). Generally, a clone is any organism (or group of organisms) that comes into existence with a DNA base sequence identical to that of an already-existing or previously existent organism. Although certain lower worms are naturally capable of forming clones, the use of this term with regard to animals usually refers to efforts by scientists to clone mammals and, more specifically, humans. Although potentially a new means of reproduction, cloning in humans is primarily viewed as a source of embryonic stem cells for research and potential transplantation. As cloning is not a natural occurrence for humans (except for the case of identical twins), scientists are developing specialized techniques to allow the cloning of humans. Although potentially useful in research and/or therapy, the process remains ethically controversial, particularly with religious conservatives. Because many considerations of the ethical, legal, and social impact of cloning begin with fundamental discussions of how cloning is carried out, and by extension what a clone is and what respect and protections it ought to be afforded, a basic understanding of cloning and its differences from fertilization is crucial to evaluating the competing arguments. Normal human development begins with fertilization: the fusion of egg and sperm to form a zygote. After four to five days of growth and differentiation, the zygote reaches the blastocyst stage (100 to 200 cells). If this development has taken place in utero,
the blastocyst may implant on the uterine wall and, with the right conditions, develop into a newborn in due course. If fertilization is done in vitro (IVF), there is no reason the blastocyst must ever be implanted. Blastocysts have been maintained in media for up to 14 days. During this period, it is possible to extract embryonic stem cells from the blastocyst. Blastocysts have also been maintained indefinitely in cold storage where they might be later used as a source of embryonic stem cells or as part of an IVF procedure leading to pregnancy and, later, birth. While there are several techniques that a scientist might use to create a clone, the common usage of cloning with respect to animals is a technique known as somatic cell nuclear transfer (SCNT). Cloning of mammalian species via SCNT is a complex, multistep process. First, an egg cell is obtained from a female (not unlike IVF). This cell is then enucleated (the nucleus is removed). Concurrently, a nucleus is removed from a somatic cell of the organism being cloned. This nucleus is placed into the newly enucleated egg cell. This cell is then stimulated to launch a cascade of biochemical events leading to cell division resembling that of a zygote arising from fertilization. With respect to humans, there are two clear purposes to cloning—reproduction and therapy—giving rise to two labels for a fully defined cloning protocol that specifies the fate of the blastocyst generated by nuclear transfer. Reproductive cloning is cloning carried out with the intent to merge the practice of SCNT with IVF, eventually leading to pregnancy and birth. Therapeutic cloning is the practice of SCNT for the purposes of extracting embryonic stem cells from the resultant blastocyst. It is envisioned that such stem cells may be used in the treatment of conditions marked by the degeneration or loss of certain cell types or functions by coaxing the stem cells to differentiate into needed cell types, a process known as stem cell therapy. Therapeutic cloning necessarily plays a significant role in stem cell therapy. To date, there has been no credible claim that a human product of SCNT has been implanted in a woman and brought to term (the practice has, in fact, been roundly condemned by all but a tiny minority) and only limited reports that SCNT has been used as a source of stem cells, though this is the major goal of current research and the major source of ethical contention.
Clone
Ethical Considerations and Religious Perspectives Secular arguments about the ethics of cloning may be divided by the level of respect granted to the blastocyst. This division has been at the heart of most political, ethical, and legal debate surrounding the practice of human cloning. In general, one may ascribe to the blastocyst status approximately equal to that of a person, status equal to any other aggregation of cells (e.g., a cheek swab), or an intermediate status supporters have termed special respect. The first generally precludes cloning as an ethical activity; the second permits it. The intermediate position does not preclude research on the blastocyst, even research that destroys the blastocyst, but it does preclude the use of such processes merely for convenience. Religious commentary on SCNT largely falls into the same three positions as secular argumentation. That is not to say that there is uniformity of opinion within religions, particularly between the various sects of Christianity, which have widely divergent views on the nature of the zygote and blastocyst. Within Christianity, the Roman Catholic Church and many Protestant denominations are prominent opponents of SCNT on the grounds that it leads to the intentional killing of persons who come into being at the moment of conception. Other Protestant denominations take markedly different views. In particular, Anglicanism, which has long held that personhood is acquired sometime between conception and birth, does not object to the destruction of blastocysts per se. Rather, the Anglican Communion objects to the creation of life for the purpose of its destruction, a clear condemnation of SCNT. Islamic and Jewish ethics, in their most orthodox forms, have a long history of embracing IVF only when it does not use donor gametes or surrogate mothers. No major cases relating specifically to cloning have come to pass, but many scholars of Jewish and Islamic law suggest that while prior to ensoulment (40 or 120 days depending on the school of law consulted) research leading to the destruction of an embryo may be permissible, the explicit creation of an embryo for such a purpose would be abominable. This position actually echoes the Anglican position, reached by a radically different mode of thinking. Buddhism speaks without a clear voice on this point. Instead, two principles at odds with each other
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are presented and adherents are left to contemplate them. Given the emphasis Buddhists place on knowledge and compassion, advances that might come from cloning, research is to be praised. However, Buddhists also place emphasis on ahimsa (nonharming). The destruction of blastocysts is potentially prohibited by the First Precept of Buddhism, which prohibits causing death or injury to living creatures. Legal Status The legal regulation of cloning varies significantly between jurisdictions. Generally speaking, blastocysts are not legal persons, whether created by fertilization or SCNT, so common law and laws designed to regulate research on persons are of little use in the regulation of cloning. Despite the wide variation in regulatory practice, regimes typically fall into a handful of categories. Some countries have regulatory oversight, but while exposing such research to enhanced scrutiny, do not generally restrict nonreproductive cloning practices. Many regimes in southeast and east Asia (but not Japan) along with the United Kingdom (UK) and Belgium have such a system. In contrast to the UK and Belgium, most of the rest of the European Union takes a more restrictive approach to cloning, banning or severely restricting the use of SCNT specifically for research purposes through adoption of relevant articles in the Oviedo Convention of 1997. The United States, with a strong historical tradition of devolving regulatory responsibility for healthcare to the states, has taken a different tack. There is no federal prohibition on any cloning activity. Instead, current policy is to withhold federal funding for such activities. Into this regulatory vacuum, states have adopted widely varying rules, from Arkansas’s total ban on all cloning activities to Connecticut’s ban on reproductive cloning only to California’s ban on reproductive cloning coupled with a significant public funding effort to support therapeutic cloning. SEE ALSO: Abortion; Stem Cells/Stem Cell Transplanta-
tion.
BIBLIOGRAPHY. National Bioethics Advisory Commis-
sion, Ethical Issues in Human Stem Cell Research, Volume I: Report and Recommendations (National Bioethics Advisory Commission, 1999); Parliamentary Office of Science and Technology, “Stem Cell Research,” www.parliament.
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uk/post/ (cited October 2006); I. Wilmut, et al., “Viable Offspring Derived from Fetal and Adult Mammalian Cells,” Nature (v.385, 1997). Bimal P. Chaudhari Boston University
Club Drugs Law enforcement and healthcare professionals use the term club drugs to reference a group of diverse substances that have come to be used in social settings such as dance clubs, raves, concerts, and parties. Club drugs differ from opiates such as heroin and marijuana in part because they are synthetics produced in licit or illicit laboratories. For example, ecstasy is largely produced by illegal laboratories in Belgium, Luxembourg, and Asia. Methamphetamine is produced from cold medications and household chemicals. They often have licit uses. Ketamine is licensed for use in the United States as a sedative; methamphetamine is licensed for treatment of obesity and attention deficit hyperactivity disorder; and GHB is indicated for narcolepsy. The United Nations (UN) estimated that of the approximately 200 million illicit drug users worldwide in 2004, 9.7 million were ecstasy users and 25 million were amphetamine users. Amphetamine-type drugs are considered the second most widely used drug globally (behind cannabis). Treatment demand for these drugs is highest in east and southeast Asia, Oceania, North America, and Europe. Amphetaminetype drugs and ecstasy account for approximately 10 percent of drug seizures (cocaine is 9 percent). Trends vary by country and by specific drug, but amphetamine and ecstasy use appears to have increased over the last decade. In 2005, the UN reported a 22-percent increase in ecstasy use in 2005, which it attributed to improved reporting in less developed countries. The U.S. Centers for Disease Control and Prevention (CDC) reports that illicit drug use is associated with higher rates of unintended pregnancy and sexually transmitted diseases such as viral hepatitis and human immunodeficiency virus (HIV). In addition, recent research suggests club drug use is more common among men who have sex with men, and increases the risk of contracting HIV among this population.
Gamma hydroxybutyrate, ketamine, and flunitrazopam have been used to facilitate the sexual assault of women. The drug is often mixed with alcohol or food and given to unsuspecting victims, who are assaulted after being partially or completely incapacitated. Generally, mixing club drugs with alcohol can increase the likelihood of side effects and other risks. Current national and international drug control efforts focus on the pursuit of manufacturers, distributors, and users of illicit drugs, and on regulated inventory management of medications with legal uses. Public health officials are attempting to improve public awareness of specific risks, including educating potential users about both drug avoidance and prevention of severe health effects. For example, a campaign in the United States tries to educate teens about the potential for brain damage associated with 3,4methylenedioxy-N-methylamphetamine (MDMA) use; another campaign encourages the consumption of water before and during dance parties to reduce the risk of malignant hyperthermia and death. SEE ALSO: AIDS; Amphetamines; Drug Abuse; Drug En-
forcement Administration (DEA).
BIBLIOGRAPHY. Grant Colfax and Robert Guzman, “Club
Drugs and HIV Infection: A Review,” Clinical Infectious Diseases (v.42, 2006); Thomas E. Freese, Karen Miotto, and Cathy J. Reback, “The Effects and Consequences of Selected Club Drugs,” Journal of Substance Abuse Treatment (v.23, 2002); Jane Carlisle Maxwell, “Party Drugs: Properties, Prevalence, Patterns, and Problems,” Substance Use & Misuse (v.40/9– 10, 2005); United Nations Office on Drugs and Crime, World Drug Report 2006, www.unodc.org (cited December 2006); U.S. National Institute on Drug Abuse, www.clubdrugs.gov (cited December 2006); Drug Enforcement Administration, www.usdoj.gov/dea (cited December 2006). Amber Sinclair University of Georgia
Cocaine Abuse Cocaine is a white crystalline powder that is extracted from the leaves of the coca plant. When ingested in quite small quantities, cocaine produces a state of eu-
phoria, mental acuity, and freedom from fatigue that is very attractive to many people. As a result, the production and distribution of cocaine, which has been designated an illegal narcotic internationally, has become a major international undertaking involving an unknown number of producers. The enormous demand for the drug mostly derives from the developed world and the United States in particular. The coca plant grows wild in Ecuador, Bolivia, and Peru, where local people had been chewing its leaves since before recorded history and enjoying the stimulant effect associated with it. Chewing the leaf also ameliorates the effects of hunger, thirst, and fatigue; it was regarded as a gift from the gods and, consequently, has important cultural connotations in those societies. In this context, the hallucinogenic effect of intense use of the drug was often employed. Europeans visiting South America noticed this phenomenon and its use spread. Cocaine was extracted from the leaves and transformed into a white powder which, being concentrated, has a much more intense effect than the leaves. Initially, cocaine was regarded as something of a miracle cure for all kinds of ailments and it was distributed widely as part of various well-known soft drinks. Coca Cola, for example, was marketed as a product able to combat menstrual cramps, headaches, and alcoholism, among other health issues. The company changed to cocaine-free coca leaves in 1903. In 1914, the United States introduced legislation to control cocaine (the Harrison Narcotic Act), under which it was designated as a dangerous narcotic. Nevertheless, the use of cocaine grew throughout the 20th century and cultivation of the plant spread across South America to as far afield as Sri Lanka and Java. Most cocaine is converted into the form of cocaine hydrochloride close to its place of production. It is then smuggled to its market after passing through various intermediaries. Commonly, the cocaine is “cut” or mixed with some other much cheaper agent with a view to increasing profitability. The cutting agent may be something comparatively harmless, such as sugar or talc, but in other cases powerful hallucinogens or even poisons may be used, which necessarily result in subsequent negative health outcomes. The purity of the cocaine bought at the street level varies anywhere from 0 to 95 percent. Smuggling is often conducted by poor or vulnerable individuals, “mules,” who carry the drug in of-
Cocaine Abuse
421
ten large quantities but are given only very limited incriminating evidence as to its origin or destination. The cocaine may be stored in a condom and the mule must swallow it to pass through customs undetected. Should the condom break inside the body, an intense reaction will immediately occur and death is a common result. Swallowing cocaine even in small quantities can lead to toxic reactions of different levels of severity but also include death. Cocaine users adopt a variety of means to use the drug. Snorting through a paper tube is probably the most common and iconic. The drug has become fashionable in some social sets and is associated especially with those such as performers who wish to recreate the high-adrenaline feeling of live performance or else with fashion models, who use the drug both as stimulant and appetite suppressant. It is also possible to inject the drug or rub it in small quantities into the body tissue, from which it can diffuse through the body. In some forms, the cocaine may be dissolved into water and ingested in that form. When the cocaine is converted into sulphate form, in which impurities are burnt away, then it is smoked in the practice known as “freebasing.” A similar process is used to create crack, or rock cocaine, which is sold in the form of solid pellets. It reportedly produces a very intense high, which is often associated with acts of violence. Generally, the more intense the feeling, the shorter lived is the stimulating effect and the
The United States designated cocaine a dangerous narcotic in 1914, but cocaine use continued to grow throughout the 20th century.
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Coefficient of Inbreeding
more rapid the onset of addiction. Breaking the compulsion is very difficult and those without money to feed their addiction are often obliged to enter a life of crime, including for example burglary or prostitution, to raise regular amounts of cash. The money required may amount to thousands of dollars per day, although this varies enormously depending on location and various supply and demand conditions. The illicit drugs trade is of such value that it has led to the involvement of organized crime and violence that threatens the international relations of a number of South American countries in particular. The lethal dose of cocaine varies considerably on a person-by-person basis and may be as low as 20 milligrams or as high as 800 milligrams. As noted above, mild use of the drug has euphoric effects and suppresses fatigue. Acute use of the drug leads to increased blood pressure and heartbeat to accompany the intensified feelings of pleasure and energy. More severe impacts include renal failure, premature birth among pregnant women, stroke, heart failure, renal failure, cerebral hemorrhage, and other life-threatening conditions. Chronic use of the drug also multiplies the possibility of heart attack by a large amount, threatens brain damage, and causes involuntary jaw movements that result in grinding of the teeth and, consequently, tooth damage and decay. Users who customarily snort the drug may suffer deterioration of the tissue separating the nostrils and, in severe cases, the nose is destroyed, together with its attendant sensory facility. Hallucinations and severe personality disorders are also observed in some cases. Regular cocaine users may be noticeable because of certain common symptoms, including bloodshot dark ringed eyes, constant sniffing, nervous motions, and significant weight loss. Owing to its anesthetic effect, cocaine has been used medicinally and in some types of surgery, although it is not particularly efficient in this regard. It may still be encountered as a local anesthetic. See also: Amphetamines; Club Drugs; Drug Abuse;
Heart Attack; Heroin Abuse.
BIBLIOGRAPHY. L.L. Cregler and H. Mark, “Medical
Complications of Cocaine Abuse,” New England Journal of Medicine (v.23, 1986); Stephen T. Higgins and Jonathan L. Katz, Cocaine Abuse: Behavior, Pharmacology, and Clinical Applications (Academic Press, 2006); Tim Madge, White
Mischief: A Cultural History of Cocaine (Thunder’s Mouth Press, 2004). John Walsh Shinawatra University
Coefficient of Inbreeding The coefficient of inbreeding, F, is a measure of the probability that two genes at any locus in an individual are identical by descent from the common ancestor(s) of the two parents. A corollary to this is that F also indicates the likelihood that an individual is homozygous, as opposed to heterozygous, at a given locus, above and beyond the likelihood of such an event occurring through random mating. Mathematically, the calculation of the coefficient of inbreeding can be traced to a method noted population geneticist Sewell Wright devised in 1922:
F=
Σ[(0.5)
n1+n2+1
]
(1 + FA)
where F is the coefficient of inbreeding, FA is the inbreeding coefficient of the common ancestor, n1 is the number of generations from the father to the common ancestor, n2 is the number of generations from the mother to the common ancestor and the summation is over all hereditary lines involving a common ancestor. In societies where inbreeding is relatively uncommon, FA can generally be assumed to be zero (this is the case where the limit of F is calculated as n1+n2→∞). However, in cultures where inbreeding is common or within families where inbreeding is known or suspected, FA can have a significant impact on F. Calculating a Coefficient of Inbreeding One of the more common occurrences of inbreeding is the mating of first cousins. Such a pedigree would have two common ancestors (both of the great-grandparents in this example). Following Wright’s method for calculating F, the great-grandfather is two generations removed from both the mother and the father and the great-grandmother is similarly distant from
Cohort Study
the parents. If we assume that neither of the greatgrandparents is inbred, then: 2+2+1 F = (0.5) 2+2+1(1+0)+(0.5) (1+0)= 0.0625 .
Suppose, however, that the great-grandfather in this family was himself the son of two half-siblings. In this case, FA for the great-grandfather is not zero. Half-siblings share a common parent (and that parent is not counted twice because it is the same parent). Thus, for the great-grandfather:
FA= (0.5) 1+1+1(1+0)= 0.125 and
F = (0.5) 2+2+1(1+0.125)+(0.5)2+2+1(1+0)= 0.0664 SEE ALSO: Birth Defects; Inbreeding. BIBLIOGRAPHY. R.L. Nussbaum, et al., Thompson &
Thompson: Genetics in Medicine, 6th ed., revised reprint (Saunders, 2004).
Bimal P. Chaudhari Boston University
Cohort Study Cohort studies are a fundamental nonrandomized study design used in epidemiology; they are designed to identify whether a particular exposure is related to an outcome of interest. In its simplest form, this observational study design compares one group (“cohort”) of individuals with a particular exposure to a group of individuals who do not have that exposure (“referent group”) over a period of time (longitudinally). Analysis yields a relative risk (RR) that reflects the relative probabilities of exposure in the two populations. Cohort studies can be classified as retrospective or prospective, depending on whether the exposure and covariates that define the cohort are measured before or after the occurrence of disease. Cohort studies are often considered the best alternative for examining potentially hazardous ex-
423
posures when random assignment is not feasible or is unethical (as would be the case with harmful exposures such as smoking). Prospective cohorts are considered a robust method for studying common exposures because the timing of outcomes versus exposures is better established, lending greater validity to a causal relationship. Cohort studies potentially require substantive investment of cost and time, as the outcome of interest might manifest only after a long exposure time. Furthermore, statistical efficiency may not be achieved if the outcome of interest is rare. Cohort studies are subject to several types of bias. Selection bias might occur when loss to follow-up through mortality or simply dropping out of the study disproportionately affects exposed or unexposed subjects. Also, quality of outcome information might differ between exposed and unexposed subjects. Cohort studies are subject to the problem of confounding: That is, the distribution of nonexposure factors that are associated with the outcome might differ coincidentally in cohort and referent groups. Exposed and unexposed subjects might experience confounding, or differential distribution of nonexposure factors that are associated with the outcome. A well-designed cohort study begins with a welldefined study population, with particular attention paid to who is included in the study, whether or not new eligible subjects are allowed to enter the cohort as time passes, and how individuals are reclassified if their exposure status changes. The Framingham Heart Study is a well-known cohort study that has been following participants from a small town near Boston, Massachusetts, since 1948. The Framingham Study has been used to identify major cardiovascular disease risk factors, such as high blood pressure, cholesterol, smoking, and diabetes. SEE ALSO: Case-Control Study; Epidemiology; Prospec-
tive Study; Retrospective Study.
BIBLIOGRAPHY. Steven Piantadosi, Clinical Trials: A Meth-
odologic Perspective, (Wiley, 2005); Kenneth Rothman and Sander Greenland, eds., Modern Epidemiology (Lippincott Williams & Wilkins, 1998).
Constance W. Liu, M.D. Case Western Reserve University
424
Colombia
Colombia Colombia is located at the northern end of South America and is the only South American nation with a coast on both the Pacific Ocean and Caribbean Sea. It is the fourth largest nation on the continent. Colombia’s climate ranges from the snow-covered peaks of the Andes to the tropical rainforest of the coast. The population has been ravaged by political upheaval and guerrilla conflict, but has at least one festival for every day of the year. The population is 43.6 million and is growing at 1.46 percent annually. With a migration rate of minus 0.3 percent per 1,000, most of this growth comes from natural increase. The birth rate is 20.48 per 1,000 and the death rate 5.58 per 1,000. Tropical conditions in the lowlands along the coast give way to a more temperate climate in the mountains. Rainfall ranges from under 30 inches a year in higher elevations to 200 inches a year in the tropics. Deforestation and soil erosion have become problems in recent years. Colombia’s economy has been hampered by ongoing armed conflict. Per capita income is $2,000 a year. Fully 50 percent of the population live below the poverty line, and 8 percent get by on $1 a day. The urbanization rate is 77 percent and has been growing at 2.6 percent annually. Life expectancy remains surprisingly high. At birth, a Colombian male can expect to live to 68.15 years; the average female lives to 75.96 years. Healthy life expectancy is 57.8 years for men and 66.3 years for women. Infant mortality is 20.35 deaths per 1,000 live births. Twenty-one of every 1,000 children die before the age of 5. Maternal mortality is 30 deaths per 100,000 live births. Prenatal care is received by 91 percent of pregnant women, but only 86 percent of deliveries are monitored by a trained attendant. An estimated 77 percent of Colombian women use birth control. Domestic violence is a huge problem, with 40 percent of women surveyed reporting abuse. Guerilla warfare has led to the internal displacement of 3 million people, 75 percent of them women and children. A third of Colombia’s children are anemic and 14 percent of them show stunted growth from malnutrition. The United Nations Children’s Fund (UNICEF) estimates that there are 910,000 orphans under the age of 17. Although officially prohibited, child welfare advocates believe that between 6,000 and 7,000 children are serving in militias. An
increasing number of children are also falling victim to sexual abuse. In the cities, 92 percent of the population have access to clean water, and 86 percent have sanitary waste facilities. Outside the urban areas, these rates drop to 71 percent with access to safe water and 54 percent with sanitary facilities. Malaria and dengue fever remain a serious concern, and there are sporadic outbreaks of yellow fever and cholera. Hepatitis B is endemic in some areas. Childhood immunization rates are above 90 percent for many major childhood illnesses; measles and rubella in particular have been brought under control. Along with the problems of a developing nation, Colombia also has all the problems of an urbanized nation. A third of all deaths are the result of heart disease. The World Health Organization estimates that 880,000 Colombians suffer from diabetes. With so many people moving to the cities, deaths from traffic accidents, homicides, and suicides continue to rise. The prevalence of HIV/AIDS remains low, with an estimated 0.7 percent of the population infected and about 190,000 Colombians now living with the virus. An estimated 3,600 have died from it. The government spends about $116 per capita on healthcare each year. In the 1990s, the government instituted what was called Law 10 to empower the General Heath and Social Security System to strengthen the national healthcare system. Its focus in recent years has been on health education, improving water standards, and prevention. The country has an estimated 58,800 physicians and 24,000 nurses. Under the Colombian system, local mayors are responsible for healthcare within their individual municipalities. SEE ALSO: Healthcare, South America. BIBLIOGRAPHY. Central Intelligence Agency, “Colombia,”
World Factbook, www.cia.gov (cited February 2007); Peter Stalker, ed., A–Z Countries of the World (Oxford Reference Online, 2006); Pan American Health Organization, “Colombia,” in Pan American Health Organization 2002 Report, www.paho.org (cited February 2007); United Nations Children’s Fund (UNICEF), “Colombia—Statistics,” www. unicef.org (cited February 2007); World Health Organization, “Colombia,” www.who.int (cited February 2007). Heather K. Michon Independent Scholar
Colonic Diseases (General) The colon is the large intestine, and is divided into several regions, based on distance through the large intestine and functional purpose of the region. Colonic diseases include colon cancer, Crohn’s disease, diverticulitis, diverticulosis, polyps, and ulcerative Colitis. Colonic diseases are quite common in the United States and around the globe. Colon cancer and the related cancer of the rectum are very common cancer types. Colon cancer has subtle symptoms, such as blood in the stool or altered appearance of stool, which are also symptoms of a variety of other digestive or intestinal disorders. Because early diagnosis of colon cancer is related to a better prognosis, annual screening of stool for blood is recommended for people older than fifty years. Colon cancer often develops from polyps, which are benign growths on the colonic lining. If a polyp begins to grow uncontrollably, it may be cancerous. Routine colonic cancer screening by a colonoscopy is recommended for older people. The colonoscopy is performed via insertion of a long flexible tube with a camera on one end, into the colon via the anus and rectum. The patient is generally sedated intravenously for this process. The extent of the colonoscopy can be total, which examines the entire colon, or flexible sigmoidal, which investigates the end portion only. If no polyps are present, the total screen can be repeated every ten years. A flexible sigmoidal colonoscopy should be repeated every five years. Crohn’s disease is a chronic disorder of the digestive tract that often affects the large intestine, though it can affect the tract from the esophagus to the rectum. It is an inflammatory disorder that may be auto-immune. It may have genetic components, but often the cause is idiopathic, meaning it is unknown. The inflammation can result in pain and difficulty in passing stool. Crohn’s patients can benefit by following a diet regimen that avoids aggravating foods while maintaining proper nutrition, taking corticosteroids and antibiotics if necessary, and painkiller medications. A supplement of vitamin E may need to be added to the diet, as Crohn’s patients may not absorb enough vitamin E from a regular diet. Sometimes surgery may be recommended, to remove parts of the diseased organ. Surgery is not always successful, and inflammation often recurs. The disease typically inflames during periods of high stress or after exerting physical activity.
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Diverticulosis and diverticulitis together are called diverticular disease. A diverticulum (plural: diverticula) is an outpouching of the colon. These outpouches appear in weak spots in the colon, and are not uncommon. When a person has diverticulosis, he or she may not present with any symptoms. If any symptoms do occur, they are typically bloating, constipation, or mild cramps. Sometimes the diverticula become infected or otherwise inflamed, which is called diverticulitis. Symptoms of diverticulitis are abdominal pain, especially tenderness in the lower left abdominal region. If the diverticulitis is due to infection of the diverticula, typically symptoms of an infection will present, such as fever, chills, nausea, fatigue, aches, etc. The infection can be treated with antibiotics and the person is often back to normal health within a few days. Diverticular disease may be lessened or prevented by a diet high in fiber. Ulcerative colitis is a disease consisting of ulcers in the lining of the colon and also of the rectum. While Crohn’s disease affects further inside the intestinal wall, ulcerative colitis is inflammation of the intestinal lining. Ulcerative colitis can affect different regions of the colon and rectum, and depending on the affected region, the disease is called different names. For example ulcerative proctitis inflames the lower colon and the rectum. Pancolitis inflames the entire colon, and limited or distal colitis inflames only the left (distal) colon. Crohn’s disease and ulcerative colitis are examples of Inflammatory Bowel Disease (IBD). IBD is not to be confused with Irritable Bowel Syndrome (IBS). IBS is a chronic disorder that is very common, affecting approximately one in five adults in the United States. SEE ALSO: Colon Polyps; Colorectal Cancer; Diverticulo-
sis and Diverticulitis; Gastroenterologist; Gastroenterology; Inflammatory Bowel Disease; Ulcers. Bibliography. Tracie M. Dalessandro, What to Eat
with IBD: A Comprehensive Nutrition and Recipe Guide for Crohn’s Disease and Ulcerative Colitis (iUniverse, Inc., 2006); ICON Health Publications, Colon Disease: A Medical Dictionary, Bibliography, and Annotated Research Guide to Internet References (ICON Health Publications, 2004). Claudia Winograd University of Illinois at Urbana-Champaign
426
Colon Polyps
Colon Polyps The term colon polyp describes a growth or mass that protrudes into the open space of the colon from the normal colon wall or lining. Colon polyps are a very common finding in men and women of all races, and some have the potential to become cancer. The transformation to cancer typically takes several years. Depending on location, type, and size, polyps can cause bleeding, anemia, abdominal pain, and obstruction, but are most commonly asymptomatic. This lack of symptoms is one reason screening tests such as colonoscopy are performed. Risk factors for the development of colon polyps seem to include a high animal fat diet, especially red meat, low dietary fiber intake, obesity, and possibly cigarette smoking. Colon polyps are typically sporadic, but familial syndromes do exist leading to a predisposition for polyp and/or cancer development. The most common types of polyps found in the colon are neoplastic or adenomatous, and nonneoplastic. There are several types of nonneoplastic polyps including hyperplastic, juvenile, inflammatory, and hamartomas. The most common type of nonneoplastic polyp is hyperplastic and these have historically been considered to have little or no potential to become malignant or cancerous. The adenomatous polyps, on the other hand, do have the potential to become malignant. Twothirds of colon polyps are adenomatous, and most colon cancers come from adenomas. However, only a small percentage of adenomatous polyps develop into cancer. Larger adenomatous polyps are more likely to develop into cancer. Adenomas are further classified based on their microscopic (histological) appearance as tubular, villous (having a finger-like appearance), tubulovillous, pedunculated (having a stalk), or sessile (broad based). Adenomatous polyps are growths arising from glandular tissue, compared to hyperplastic polyps that come from excessive proliferation or overgrowth of normal colonic tissue. The less common polyps include hamartomas, which arise from spontaneous new growth of otherwise normal tissue. Juvenile polyps are a type of hamartoma that are more likely to bleed. Inflammatory polyps are irregular and result from an inflammatory or immune response within the colon. A procedure known as colonoscopy is usually how polyps are found. Colonoscopy procedures use a fiber optic camera inside the lumen of the colon to screen
for colon cancer and are also performed for various other reasons. Generally, the polyps can be removed during colonoscopy, a procedure known as polypectomy. Some polyps are found to have malignant or cancerous characteristics upon further microscopic examination. Occasionally, very large polyps require a more aggressive surgical removal. Once a person has been found to have colon polyps, they are at an increased risk to develop more. Research is ongoing to determine ways to prevent polyp formation. Some recommendations that have been made include avoiding cigarette smoking and heavy alcohol intake, and adding dietary calcium carbonate, folic acid, and selenium supplementation. Staying at your ideal body weight with a low-fat diet that is rich in fiber, fruits, and vegetables is also recommended. SEE ALSO: Colonic Diseases (General); Colorectal Cancer. BIBLIOGRAPHY. Anne Charette and Robert H. Fletcher,
“Patient Information: Significance of Colon Polyps,” www. utdol.com (cited August 2005); Vamen Jakribettuu and Dennis J. Ahnen, “Approach to the Patient with Colonic Polyps,” www.utdol.com (cited July 2005). W. Joshua Cox, D.O. Kansas City University of Medicine and Biosciences
Colorectal Cancer Colorectal cancer by definition is any malignancy occurring as a primary site in the ascending, transverse, or descending colon including the sigmoid and rectal ampulla. Many statistics are available and continue to be collected regarding this frequently occurring and fatal, yet curable, disease. This seemingly contradictory description is nonetheless true, because increased public awareness programs, aggressive screening recommendations, and early diagnosis render this a potentially highly curable disease. Colorectal cancer is the third most common cancer in the United States and is second only to lung cancer as a cause of cancer death. Worldwide, colorectal cancer is the fourth leading cause of cancer death. In the United States, a person has approximately a
6 percent lifetime chance of developing colorectal cancer, but studies show that the frequency of occurrence and death increase with advancing age. Ninety percent of newly diagnosed colorectal cancers and 94 percent of all colorectal cancer deaths occur in patients over the age of 50. For 2006, 148,610 new cases of colorectal cancer are estimated (72,800 males and 75,810 females). Additionally, 55,170 deaths due to colorectal cancer are predicted in 2006 (27,870 males and 27,300 females). This represents approximately 10 percent of all cancer deaths. Historically, men have had a 35 percent higher rate in occurrence rate and death as compared to women. Furthermore, between the ages of 60 and 79, men have 60 times greater chance and women have 48 times greater chance of developing colorectal cancer as compared to the population younger than 39 years of age. Racial and ethnic differences are noted both in occurrence and mortality rates. For instance, AfricanAmerican males have the highest rate of incidence and mortality (72.9 and 34.3 per 100,000 respectively) as compared to non-Hispanic white males (63.1 and 24.8 per 100,000 respectively). In the United States, the incidence of colorectal cancer has slowly decreased, beginning in 1998, but the incidence rate for occurrence in the ascending colon (right-sided colorectal cancer) has increased. Early screening and early polypectomy may be, in part, responsible for this shift. Risk factors Familial adenomatous polyposis (FAP) and hereditary nonpolyposis colorectal cancer (HNPCC) are the two most common forms of inherited familial colorectal cancer syndromes, but they only represent 5 percent of the total new cases each year. FAP, in its various forms, is characterized by an inherited tendency to develop multiple (sometimes hundreds) of colonic polyps of an adenomatous histology. In the most common subtype of FAP, 90 percent of untreated patients will develop colorectal cancer by age 45. In HNPCC (which is actually more common than FAP) individuals develop colon cancer as young as 20 years old, with the average age of diagnosis being 48 years of age. Most (70 percent) of the cancers occur proximal to the splenic flexure and some 10 percent of the cases have synchronous cancers separated by normal bowel. Sporadic cancers are thought to develop from adenomatous polyps. It is noted that if there is a fam-
Colorectal Cancer
427
ily history of adenomatous polyps then this confers the same risk to the individual as if there were a family history of colorectal cancer. Inflammatory bowel disease, specifically ulcerative colitis (UC), is another risk factor in development of colorectal cancer. If UC involves the entire large bowel, there is as much as 15 times the risk (compared to the general population) of developing colon cancer and if UC is restricted to the left side (descending colon) the risk is three times that of the general population. Inflammatory bowel disease restricted to the rectum does not appear to increase the risk of developing colorectal cancer. For individuals who have had UC for 10 to 20 years, there is an approximate occurrence of colorectal cancer of about 0.5 percent per year and a 1 percent per year colorectal cancer occurrence after 20 years of the presence of UC. After 40 years of UC, which affects the entire colon (pancolitis), the probability of developing colorectal cancer is approximately 30 percent. Crohn’s disease, which can affect the entire alimentary canal, also shows a similar risk factor in developing colorectal cancer. Interestingly, type 2 diabetes mellitus and the consequent insulin resistance are risk factors for developing colorectal cancer. Insulin acts as a growth stimulant for colonic mucosal cells and type 2 diabetes and hyperinsulinemia support the increased growth of polyps and colonic tumor cells. Alcohol increases the risk of developing colorectal cancer when the daily consumption of alcohol exceeds 45 grams. Smoking is a definite risk factor in colorectal cancer occurrence. The American Cancer Society in 2000 estimated that approximately 12 percent of the 1997 deaths from colorectal cancer were due to cigarette smoking. In that review, current male smokers had a 32 percent higher death rate compared to nonsmokers and current female smokers had a 41 percent higher death rate compared to nonsmokers. Furthermore, in that study, the statistics were worse in smokers who had smoked more per day and for more years. These data are from the Cancer Prevention Study II and analyzed statistics on 312,332 men and 469,019 women. A recent study documents that the highest incidence of colorectal cancer is found in individuals who have smoked more than 20 years and who never used nonsteroidal antiinflammatory drugs. Smokers who did use nonsteroidal anti-inflammatory drugs were still at a 30 percent higher
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Colorectal Cancer
risk for developing colorectal cancer, thus showing an incomplete protection against the onset of colorectal cancer. This study was based on the medical history and medical surveillance of 3,299 people between the ages of 20 and 74, half of whom had had colorectal cancer, and the other half had not. Diet has been an area of intensive study as it relates to colorectal cancer. Since the large bowel (colon) retains the by-products of digestion (and presumably ingested toxins) until elimination (defecation) can occur, it is essential to identify those foods, metabolites and ingested toxins that can predispose an individual to colorectal cancer. Large-scale studies have produced much conflicting data, causing confusion in making recommendations. For instance, high consumption of red meat, animal and saturated fat, and refined carbohydrates (see alcohol) has an increased risk of developing colorectal cancer. Protective effects against colorectal cancer are conferred by consumption of vegetables, fruits, antioxidant vitamins (e.g., vitamins C and E), calcium, and folate. Dietary fiber was first noted to have a protective effect against colorectal cancer as early as the 1970s and was for many years considered a strong deterrent against colorectal cancer occurrence. A recent prospective study analyzing 725,628 adults indicated that high dietary fiber intake did not reduce the risk of colorectal cancer. This is certainly not in keeping with previous studies and recommendations regarding the colorectal preventative effects of high dietary fiber. The conclusion offered after these data were analyzed was that individuals who ate high levels of dietary fiber also ate less red meat, took antioxidant vitamins, and were more physically active, thus following a more healthy lifestyle. The researchers were equally clear that increased consumption of dietary fiber has proven value in helping to normalize bowel function, control blood sugar in diabetics, and control lipids, thus reaffirming the need for daily dietary fiber intake. In a five-year study in 2005 of 1,953 patients with colorectal cancer and 2,015 without colorectal cancer, the taking of cholesterol-lowering medications of the statin category was associated with a 47 percent relative reduction of colorectal cancer after adjustment was made for other risk factors. In 2006 a study by the American Cancer Society involving 132,136 patients (men and women) taking statins showed
only a weak reduction in the incidence of colorectal cancer and no specific type of statin was found to be more effective than another. Diagnosis and Treatment Many methods of screening patients and diagnosing colorectal cancer are available. Screening tests need to be relatively low risk, affordable, and have a reasonable level of security that a positive test is indicative of the presence of the condition and a negative test is indicative that the condition is not present. The fecal occult blood test (FOBT) is a reaction for blood in the stools. This positive reaction is not specific for colorectal cancer, but is based on the presence of blood in the stools (feces) because of intralumenal bleeding, which can occur from partially severed polyps (which could be cancerous) or ulcerating lesions (which may be malignant). For this test to be effective, the patient follows a diet for three days that is restricted in certain foods and medications that may cause a falsely positive reaction from the sample. The fecal smear is obtained on three separate occasions and the smears are tested by applying an acidic peroxide developer. A positive reaction indicates the presumptive presence of blood and that further workup is indicated, such as flexible sigmoidoscopy (direct examination of the descending colon with a fiberoptic flexible tube) coupled with double-contrast barium enema (radiography of the colon) or full-length colonoscopy. Colonoscopy is a direct visualization through a fiberoptic flexible tube of the entire length of the colon. The advantage of this choice is that if a lesion is seen during the procedure, a biopsy (a piece of the tissue) or complete removal of the abnormal tissue (e.g., polyp, tumor) is accomplished. This allows screening and diagnosis and possibly complete removal of the entire malignancy in one procedure. Various recommendations for screening populations at risk are available. If individuals have visible blood passage with or between bowel movements, a colonoscopy should be performed to identify the source of bleeding. In general, all men and women with average risk (no personal history or family history of colorectal cancer) should undergo screening for colorectal cancer and adenomatous polyps at 50 years of age. The options for screening are the fecal occult blood test and flexible sigmoidoscopy with
Colorectal Cancer
double- contrast media (air and barium). In individuals with increased risk, such as personal history of colorectal cancer, ulcerative colitis, Crohn’s disease, and/or adenomatous polyp, a colonoscopy is indicated. Because each of the tests carry some risk to the patient, from not capturing the presence of an abnormal lesion to causing injury to the patient (puncturing the colon, hemorrhaging, infection), the individual and the physician together need to determine the best screening and diagnostic pathway based on the patient’s personal and family medical history, preferences, and the likelihood and ability of the patient to adhere to the mutually agreed upon strategy. Without question, surgery offers the best potential benefit for a cure of colorectal cancer, especially if the cancer is found early. Surgery by a colonoscopy-directed biopsy includes the complete removal of the cancerous lesion that is contained completely within the colon, and this may be followed by removal of more of the colon through an open abdominal surgery (laparotomy) to insure that tiny portions of cancer (metastasis) in neighboring colonic tissue are removed. Lymph nodes are also removed and examined so that an estimate (staging) of the colorectal cancer can be made. Spread of the cancer may be to lymph nodes in the area, distant lymph nodes, and other organs, such as the liver and lung. Even if the cancer has spread to the liver (which usually is considered to be incurable by surgery alone), removing a portion of the colon and rerouting the fecal stream may be necessary to prevent painful and life-threatening bowel obstructions from the tumor enlarging inside the bowel. Sometimes, depending on the location of the colorectal cancer in the colon, the remaining end portion of the bowel is brought to the outside of the abdominal wall where the fecal material is captured in a disposable bag (colostomy). Radiation therapy (the use of intensive X-ray beams to a specific area) is sometimes used to shrink tumors before surgery to help in the removal procedure. Radiation therapy is also used to help shrink tumors that cannot be completely removed. Finally, radiation therapy is directed to colorectal cancer metastases to painful organs, such as the liver and bone, in an effort to help decrease the pain and offer palliative (noncuring comfort) care.
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Chemotherapy is used to treat all stages of colorectal cancer. For decades, 5-fluorouracil was the gold standard as the only chemotherapy for colorectal cancer. Now, many new forms of chemotherapy are available and are being investigated to find the best combination and timing for use of these agents. Because of the prevalence of colorectal cancer, much new research is underway. The best treatment is the individual’s own awareness of the family history and personal bodily function, and early screening for the condition. See also: Cancer (General); Colonic Diseases (General);
Colon Polyps.
BIBLIOGRAPHY. American Cancer Society, www.cancer.
org (cited October 2006); Peter A.L. Bonis, Dennis J. Ahnen, and Lisen Axell, “Screening Strategies in Patients and Families with Familial Colon Cancer Syndromes,” UpToDate, www.uptodate.com (cited August 2006); Carolyn C. Compton, “Pathology and Prognostic Determinants of Colorectal Cancer,” UpToDate, www. uptodate.com (cited August 2006); Robert H. Fletcher, “Family History of Colorectal Cancer: Risk, Pathogenesis, and Screening,” UpToDate, www.uptodate.com (cited August 2006); Robert H. Fletcher, “Screening for Colorectal Cancer,” UpToDate, www.uptodate.com (cited August 2006); Edward Giovannucci, and Andrew Chan, “NSAIDS: Role in Prevention of Colorectal Cancer,” UpToDate, www.uptodate.com (cited August 2006); Russell Harris, “Overview of Preventive Medicine,” UpToDate, www.uptodate.com (cited August 2006); Brian C. Jacobson, Beverly Moy, and Francis A Farraya, “Surveillance after Colorectal Cancer Resection”, UpToDate, www.uptodate.com, (cited August 2006); Steven Lawrence, and Dennis J. Ahnen, “Clinical Manifestations, Diagnosis, and Staging of Colorectal Cancer,” UpToDate, www.uptodate.com (cited August 2006); Mark J. Ott, and Jean-Pierre En Pierre, “Surgical Management of Primary Colon Cancer,” UpToDate, www.uptodate. com (cited August 2006); Mark A. Peppercorn, and Robert D. Odze, “Colorectal Cancer Surveillance in Inflammatory Bowel Disease, UpToDate, www.uptodate. com (cited August 2006). Richard K. Ogden, D.O., FACOFP, FAAFP Kansas City University of Medicine and Biosciences
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Coma
Coma Originating from the Greek word for “deep sleep” (koma), a coma is a profound state of unconsciousness. Consciousness, on the other hand, is the state of awareness of the self and the environment in which individuals are responsive to stimuli. Scientists believe that the neurotransmission of chemical signals to the brain is essential to consciousness and responsiveness. Because the brain of a person in a coma is malfunctioning, responsiveness is absent. At the functional level, a coma is caused by a primary or secondary brain stem injury and by diffuse cortical causes that may be toxic, anoxic (characterized by a lack of oxygen), or metabolic. Swelling in the brain (edema) causes intracranial pressure, which may be limited to one part of the brain or may encompass the entire brain. Intracranial causes of coma tend to be neoplastic, inflammatory, hemorrhagic, infectious, and traumatic in nature. Extracranial causes may be toxic, anoxic, circulatory, or metabolic. Herniation occurs when areas of the brain shift from their proper positions. Degrees of decreased responsiveness to stimuli may be separated into four distinct groups. In Grade I drowsiness, lethargic, somnolent, and uninterested individuals are easily aroused into consciousness. During Grade II stupor, patients immediately lapse into sleep if left undisturbed. The deep stupor of Grade III is marked by responses to strong, painful stimuli but motor responses and facial movements are inappropriate. Patients in all three categories are able to breathe on their own. Patients may not be able to breathe on their own in the deep coma of Grade IV. In this state, patients do not respond to any kind of stimuli, and reflexes are absent. Using a scale of 3 to 15, the Glasgow Coma or Responsiveness Scale ranks eye opening, verbal response, and motor responses to determine the extent of consciousness. Eye movement rankings range from spontaneous (4) to never (1). Best verbal responses are ranked from orientated (5) to none (1). Best motor responses are classified from obeys commands (6) to nil (1). A coma may be a response to an illness such as diabetes, uremia, or stroke, or to chemical or biological agents, or it may result from severe head traumas. Brain measurements of persons in comas are vastly dissimilar to those taken in individuals who are sleeping. In most cases, a coma lasts no longer than a few
weeks; and many individuals return to normal physical and mental activity after waking. Patients who have been in extended comas or who have neural or physical damage ranging from moderate to severe may need to undergo rehabilitation or remain in managed care. Patients often slip from a coma into a vegetative state from which they do not recover. In this state, the patient is able to breathe, either on his or her own or with a respirator; however, cognitive neural functions are absent even if the patient seems to be awake. In rare cases, patients have periods in which they arouse followed by relapses into a coma state. How much individuals in comas understand about the world around them has been hotly debated. One study of 111 patients who had awakened from comas at a Hartford, Connecticut, hospital revealed that 27 percent had no recollection of anything that had happened while they were unconsciousness. Out-of-body
The majority of coma patients are young people who have been in accidents, but they are more likely to survive than people over 50.
experiences were reported by 23 percent. Fourteen percent stated that they had experienced distorted consciousness involving hallucinations, memory lapses, or personality changes. Nine percent reported that they had an inner awareness of outside events. Diagnosis and prognosis Diagnoses of the severity of comas and the likelihood of recovery are based on interpretation of physical signs and brain activity. Since the majority of coma patients are young people who have been involved in traumatic accidents, there are great emotional, social, and financial stakes involved in charting treatment plans. A coma resulting from a severe head injury is diagnosed after a period of unconsciousness that lasts for at least six hours. One study found that in 96 percent of such patients, death took place within 48 hours. Physicians are not able to predict outcomes for coma patients with accuracy, and they are often forced to take a wait-and-see attitude. As a general rule, the longer patients are in comas, the less likely they are to recover. If severe edema is present after a traumatic injury, physicians may place a patient in an artificial coma so that he or she will not wake up in order to give the body a chance to heal and the swelling to disappear. If this happens, the patient is allowed to awaken gradually. In cases where edema persists along with extensive brain damage, the prognosis for recovery is poor. Findings from several neurosurgical centers have revealed that around half of coma patients with head injuries recover. In one study of patients with nontraumatic coma, 16 percent made a full or partial recovery. However, 70 percent either died or remained in a vegetative state for at least a month after the onset of the coma. The most significant factor in potential recovery is whether or not patients exhibit signs of brain stem function. If papillary response, oculocephalic responses, or both, are absent, the prognosis is poor. There is evidence that 96 percent of those who do not exhibit these responses die within six hours of the onset of a coma. In 91 percent of coma patients whose pupils were fixed after 24 hours, death followed. Only four percent achieved satisfactory recovery. Some studies support the findings that young people are more likely than people over the age of 50 to survive, regardless of the length of the coma. In the latter group, less than half were able to return to work if they had
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remained unconscious for more than a day. In all age groups, among patients who exhibited abnormalities in both eye signs and motor defects, the survival rate was only 7.8 percent. In 2006, The Journal of Head Trauma Rehabilitation reported on a study designed to determine postinjury outcomes of 339 patients with traumatic head injuries. Brain injuries ranged from mild (230) to moderate (48) to severe (52). In addition to social factors such as age and prior-injury educational level, post-trauma prognoses were based on the Glasgow Coma Scale score, duration of post-traumatic amnesia, cerebral imaging results, and presence or lack of neurosurgical interventions. The Extended Glasgow Outcome Scale was used in determining outcome measures. The team conducting the study concluded that patients with the shortest period of post-traumatic amnesia were the least likely to develop moderate to severe disabilities. Patients with positive cerebral imaging, indicating epidural, subdural, subarachnoid, parenchymal, or intraparenchymal lesions, skull fracture, and unilateral or bilateral lesions, were the least likely to be discharged from professional supervision. Some patients who recover from comas after experiencing traumatic brain injury have been diagnosed with depression. In an article published in The Journal of Head Trauma Rehabilitation in spring 2007, a team of scholars examined factors related to post-coma depression, including age, education, substance abuse, family support, and psychiatric history. Standard classifications were used to identify the extent of individual injuries. There was no statistically significant difference in the level of depression among those with mild, moderate, and severe brain injury. Some differences in levels were explained by pre-injury level of education, previous psychiatric history, and preconceived support levels. The strongest impact on both early and late surfacing depression was patients’ selfassessment at the time of discharge. External responses to coma The first Humane Society was founded in Amsterdam in the Netherlands in the 17th century. Other countries followed suit, and the first North American society was founded in Philadelphia, Pennsylvania, in 1780. The focus at that time was in developing ways to revive drowning victims. Mechanical respirators later provided a major breakthrough in dealing with
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coma patients who were not able to breathe on their own, and brain resuscitation methods were instituted to promote survival of the neurons and prevent brain death. Major breakthroughs in respiratory resuscitation and intensive care occurred in the 1950s. During the following decade, cardiac resuscitation and emergency cardiac care paved the way for greater numbers of coma patients to survive, offering hopes of recovery to relatives and friends. Since the 1970s, improvements in critical care medicine have precipitated even greater progress in treating coma patients. Efforts at brain resuscitation in the 21st century involve basic and advanced life support, diagnostic and monitoring techniques, and brain activity measurements. Because advanced medical technology allows patients in prolonged comas to live for years, the rightto-die issue has become a hot-button political topic throughout much of the world. Advocates of the right to die believe that life should not be prolonged when there is no hope of recovery, particularly in instances where patients have made prior acknowledgment that they would not choose to remain on life support. Hospice care has surfaced as a humane alternative, giving patients and their families a comforting environment in which patients are allowed to die with dignity. Opponents of the right to die argue that as long as a person is breathing and has a heart beat, even if it is by artificial means, all efforts should be directed toward prolonging life. In 1968, the term death was first used in the United States to refer to the point at which the heart and lungs no longer functioned. The term brain dead was used to describe the state in which these functions were performed by artificial means on patients who could no longer function on their own. Controversy continues over the care and monitoring of patients experiencing prolonged unconsciousness. In the face of the controversy, most countries have responded in ways that reflect their own cultures. In Japan, for instance, the term brain dead has no legitimate scientific meaning. Because of this, Japanese physicians are banned from harvesting organs to be used in organ transplants. At the other end of the spectrum, the Dutch strongly support the right to die and consider it an individual decision. Legal controversy In 1976, at the age of 22, Karen Ann Quinlan was determined to be legally brain dead after a drug over-
dose. A decision by her parents to subsequently remove her from a respirator was challenged in court. Nevertheless, the respirator was ultimately removed, and Quinlan lived for several years in a vegetative state. In 1983, at the age of 26, Nancy Beth Cruzan went into a coma after being involved in an automobile accident. She was kept alive via hydration and a feeding tube. Her parents’ decision to remove her from life support was also challenged. A number of witnesses testified in court that Cruzan had repeatedly stressed the fact that she would not wish to be kept alive through artificial means if there was no hope of recovery. In 1990, in Cruzan versus Director, Missouri Department of Health (497 U.S. 261), the United States Supreme Court acknowledged that competent individuals have a liberty interest that is derived from the Due Process Clause of the 14th Amendment that allows them to refuse medical treatment. However, patients who are in comas are not considered competent; unless compelling evidence of their disinclination to remain on life support exists, the state retains a compelling interest in sustaining life. No other case of a coma patient who relapsed into a years-long vegetative state has received more attention around the world than the case of Terri Schiavo. The Florida resident had developed an eating disorder, dropping from 250 pounds as a teenager to 110 pounds within six years of her marriage to Michael Schiavo. On February 25, 1990, at the age of 26, Schiavo was alone in her apartment when she went into cardiac arrest. In the absence of immediate medical help, her brain was without oxygen for 10 to 12 minutes. Around half that period has been known to cause irreversible brain damage. Emergency personnel resuscitated her, and she was placed on a respirator. Terri Schiavo emerged from the coma a month later, lapsing into a persistent vegetative state. Her husband Michael and her mother, Mary Schindler, served as her caregivers for the next three and one-half years. Experimental treatment in California was unsuccessful, and Schiavo was diagnosed with irreversible and extreme brain damage. Michael Schiavo won a malpractice lawsuit against Shiavo’s fertility doctor, claiming that he had been negligent in treating his wife. The jury awarded Michael $300,000 for loss of consortium, and $700,000 was placed in a court-managed trust to pay for Terri Schiavo’s care. In 2003, Michael Schiavo sought legal permission to remove his wife’s feeding
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tube. After her parents challenged the decision, a legal and moral uproar ensued that ultimately involved Florida governor Jeb Bush, his brother, President George W. Bush, and the United States Congress. The Supreme Court refused to enter the fray. Terri Schiavo died two weeks after her feeding tube was removed in 2005. Autopsy reports supported Michael Schiavo’s conviction that his wife could not have recovered. See also: Adolescent Health; Brain Injuries; Depression;
Diabetes Type I (Juvenile Diabetes); Diabetes Type II; High Blood Pressure; Neuroscience; Organ Donation; Organ Transplantation; Rehabilitation; Stroke. BIBLIOGRAPHY. Arthur L. Caplan, et al., The Care of Ter-
ri Schiavo: Ethics at the End of Life (Prometheus Books, 2006); Alexander Capron and Margaret Lock, eds., Deadly Disputes: Understanding Death in Europe, Japan, and North America (University of California Berkeley, 1995); C.A. Carlsson, et al., “Factors Affecting the Clinical Course of Patients with Severe Head Injuries,” Neurosurgery (v.29, 1968); Elaine de Guise, et al., “Prediction of Outcome at Discharge from Acute Care Following Traumatic Brain Injury,” The Journal of Head Trauma Rehabilitation (v.21/6, 2006); Leslie B. Ivan and Derek A. Bruce, Coma: Physiopathology, Diagnosis, and Management (Charles C. Thomas, 1982); Madelaine Lawrence, In a World of Their Own: Experiencing Unconsciousness (Praeger, 1997); Barbara J. Logue, Last Rights: Death Control and the Elderly in America (Lexington Books, 1993); James F. Malec, et al., “Self-Assessment of Impairment, Impaired Self-Awareness, and Depression after Traumatic Brain Injury,” The Journal of Head Trauma Rehabilitation (v.22/3, 2007); Neurology Channel, “Coma,” www.neurologychannel.com/coma (cited July 2007); Fred Plum and Jerome B. Posner, The Diagnosis of Stupor and Coma (Davis, 1982); Sue Woodman, Last Rights: The Struggle over the Right to Die (Plenum Trade, 1998). Elizabeth R. Purdy, Ph.D. Independent Scholar
Common Cold The common cold is a mild viral infection that affects the upper respiratory tract and is one of the most common viral infections in humans. The main cul-
The common cold is one of the most common human diseases; there are an estimated 1 billion annual cases in the United States.
prits behind the common cold are the rhinoviruses. After the rhinoviruses, the paramyxoviruses and the coronaviruses are contributors. The cold virus can be transmitted in many ways including airborne particles, direct contact, and fomites. Its cycle typically lasts two weeks. There is no cure for the common cold, but there are treatments that boost the immune system, prevent complications, and reduce symptoms. The molecular structure for the common cold is based on the viruses that cause the infections. Rhino viruses have small single-stranded ribonucleic acid (RNA) genomes with a 5' protein and a 3' poly-A tail like human DNA. They are encased in a capsid that contains four proteins. There are 60 copies each of these proteins within an icosohedral capsid. These proteins are the major components to which human antibodies react. Coronaviruses are large viruses with a single-stranded RNA genome. The name corona, Latin for crown, is derived from the findings of small viral spike peplomers that resemble a crown. These peplomers coat the exterior of the virus and are integral to antibody binding.
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Paramyxoviruses, indirect causative agents of the common cold or respiratory tract infections, are also worth mentioning. Paramyxoviruses include RSV (respiratory syncytial virus), bronchiolitis, and pneumonia. They, too, are contained inside a capsid but their structure is quite pleomorphic and they contain many attachment proteins used for fusion with host membranes. They also have an RNA genome inside the capsid. The genome contains the code for the N, M, P, and F proteins. The N protein is a nucleocapsid that encapsulates the genome. The M protein is the matrix protein and is used for assembly of the virion. The P protein is used as a helper protein in other processes. The F protein is the fusion protein and is used in concordance with the attachment proteins for cell binding with host membranes. Transmission As previously stated, the modes of transmission of the common cold virus include, but are not limited to, airborne transmission, contamination through direct contact of exposure to nasal secretions that contain the infection, and fomites. Fomites are inanimate objects (such as doorknobs) that have been contaminated with the virus. Transmission may occur when a host comes into contact with the fomites and picks up virus specimens. Then the host touches the nasal passageway and subsequently inhales the virus. Airborne transmission occurs when a host expels air that is contaminated with the virus, such as through sneezing. When a sneeze occurs, tiny water droplets are blown into the air. These droplets may contain the virus, and if inhaled by a potential host, may cause infection once they reach the tissue of the lungs. Coughing also causes transmission of the virus, although it has been shown that sneezes produce exponentially more airborne viruses than coughing. Once infected, the host undergoes the usual two-week cycle. The first three to four days are the most infectious, meaning that in this time period the virus can spread more easily to others as the immune system has not yet begun to fight the cold systemically. Once the virus is on a host, infection occurs in a typical way. The most common entry of the virus is through the lining of the nasopharynx, the area from the nose down to the throat. Other typical entry pathways are through the eyes and to a minor extent the mouth, although typically entry through the mouth does not occur. In the case of entry through the eyes,
the virus enters the eye and crosses down into the nasopharynx area via nasolacrimal ducts. Entry into body cells is via the ICAM-1 receptor. A cell with low concentrations or no receptors is not infected with the virus. Because of this finding, most research conducted on the common cold viruses has centered around the information found with the ICAM-1 receptor. Symptoms and Pathology Typical symptoms of the common cold include but are not limited to sneezing, coughing, malaise, sore throat, respiratory blockage, runny nose, and inflammation. During the first few days of infection the general symptoms only include a sore throat and malaise. The other symptoms are the result of the immune system. Sneezing, coughing, and a runny nose are mechanisms employed to rid the body mechanically of the virus. Respiratory blockage and inflammation are direct internal results of the host immune system activating and using chemical signals to respond to the cold by attracting the many different types of immune response cells. Once immunity has been established to a particular strain of virus, any subsequent infections with that same virus initiate a quick immune response based on previously stored memory cells. This acquired immunity decreases the length and efficacy of the virus. Although a host may have an established acquired immunity to a strain of virus, there are so many strains of the common cold (over 100) that subsequent infections rarely are the result of the same strain and therefore establish a full infection resulting in the two-week cycle. Besides the infection from the cold virus and the body’s immune response to that infection, complications can arise as a result of a cold. Because the infection causes a weakening of the immune system as it is actively fighting the cold, other opportunistic bacteria or even viruses have a better chance of causing infection. Human bodies are covered with many types of bacteria, like staph, and are therefore susceptible to coinfection. During the two-week cycle it is typical for the host to blow their nose and wipe it with tissues. When blowing the nose, covering of one nostril while the other is evacuated can cause the pressure built up inside that nostril to physically push more bacteria and/or viruses into the nasal tissues. In addition to nasal tissues, the sinus cavity can be overwhelmed with bacteria and/or viruses and this may result in typical sinusitis and middle ear infections in children.
In the United States alone, it is estimated that there are over 1 billion cases of the common cold each year. This means that the entire population of the United States becomes infected more than once each year. Typical seasons for the viruses are early spring and early fall, but they may occur year-round. Children are extremely susceptible to cold viruses as they have not been through such infections before. Therefore, once a cold infects one child, it spreads quickly. Another reason for the rapid spread is that signs of infection often do not appear for 24 to 48 hours, and the host is most infectious within the first 72 hours. It has been found that most children catch colds from other children, and most adults catch the cold from children too. The common cold is the number one reason for doctor visits, missed work, and missed school. The rate of infection is two to four times per year for adults and can be as high as 12 per year in school-aged children. As the common cold is an upper respiratory infection, it is different from the flu (influenza). Differences between the commonly mistaken diseases are evidenced by the fever, chills, and typical body aches associated with the flu. The flu virus can be life threatening and the elderly can experience confusion and drowsiness. The common cold also typically remains in the nasopharynx area of the body as it needs to be near cells that have the aforementioned receptors. These cells are packed densely into those areas. In addition to differences in symptoms, there are also differences in complications. The common cold has rarely been seen to be life threatening, but its complications and resulting coinfections (such as pneumonia) can be. Treatment and Prevention There are no known cures for the common cold but there are several in development. There are many folk remedies that are considered useful but ultimately not 100 percent effective. There are naturally occurring supplements and vitamins that seem to have some effect on the virus, but many just boost the immune system. Antiviral drugs have also been explored but to date there are none available on the open market. Prevention seems to be the best route until further developments are made. It is virtually impossible to eliminate all chances of getting a cold but there are many steps and precau-
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tions that can help prevent recurrent infections. Most of these involve the reduction of exposure to germs, bacteria, and viruses, and the other steps involve boosting the immune system. Disinfectants should be used to clean any high-traffic areas. Washing of hands or use of hand sanitizers are the most sensible precautions one can take. Hands should be washed immediately after coming in contact with possible infectious agents like soiled tissues and napkins and before nose wiping, eating, and food preparation. Supplementing the immune system is the second most common way to avoid and recover from infection. Simple steps like a good night’s sleep and proper diet contribute immensely to one’s health. Malnutrition and lack of sleep cause the body to undergo vast chemical changes and reduce the efficacy of the immune system, leaving the body susceptible to infection. In children, nutrition is extremely important. Studies have shown that children who breastfeed are five times less likely to have ear infections. The breastmilk contains vital immune cells that pass from mother to child. Because the common cold is a viral infection, antibiotics are not effective to any extent in treating symptoms. This is because antibiotics are antibacterial medications and bacteria and viruses are vastly different in their genomic and structural makeup. The call for wide-ranging vaccination is also not practical. There are so many strains within many different virus families that at present it would be impossible to construct a vaccination that encompasses all of these strains. Naturally occurring supplements and vitamins have shown some promise in boosting the immune system, but none of these have been shown to effectively combat the virus itself. Although there is no direct correlation between zinc consumption and the common cold, it has been shown that children and adults who are zinc deficient get more infections and stay sick longer. Products like echinacea have shown no efficacy against the viruses that cause the common cold. Vitamin C has shown the most promise of any naturally occurring supplement. Many studies have shown vitamin C to reduce the duration of the common cold. Linus Pauling, a Nobel Prize winner, was a strong advocate of high doses of vitamin C to prevent infection by common cold viruses. Although there have been clinical trials and tests for almost all of the preceding remedies, there have
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been many conflicting reports. With each substance there are complications: with vitamin C there is an elevated risk of kidney stone development, echinacea use is recommended for only two weeks, and zinc is naturally removed from our body in correlation with food acids like citric acid. The folk remedies of chicken soup, spicy foods, and chamomile have some effect, but to date, there is no hard scientific evidence to support that these directly combat the virus. It has been observed, however, that the spiciness of food and the temperature of soup contribute to reducing blockage of the nasal passageway. The two most promising and effective agents to combat the common cold are analgesics and antiviral drugs. Analgesics act on the central nervous system to reduce pain levels and inflammation. The most common antiviral drug developments for the common cold have targeted the receptors on the body’s cells as well as the receptors on the virus. Once the medication binds to the virus, it prohibits the virus from binding to cells, thereby not allowing the release of the genome and the proliferation of the virus. See also: Alternative Medicine; Antibiotics; Viral Infec-
tions; Virology; Vitamin and Mineral Supplements.
BIBLIOGRAPHY. Lansing M. Prescott, John P. Harley, and
Donald A. Klein, Microbiology, 6th ed. ( McGraw-Hill Science/Engineering/Math, 2004); Ellen G. Strauss and James H. Strauss, Viruses and Human Disease (Academic Press, 2001); David Tyrrell and Michael Fielder, Cold Wars: The Fight against the Common Cold (Oxford University Press, 2002).
Matthew Jordan Smith Florida State University
Comoros Comoros is an island nation located in the northern edge of the Mozambique Channel, midway between Mozambique and Madagascar. It is comprised of four islands: Ngazidja, Mwali, Nzwani, and the disputed island of Mayotte, which is also claimed by the French. The French colonized Comoros in 1841 and maintained control until the country won independence in
1975. Political stability did not follow independence; there have been 19 attempted or successful coups in 30 years. At 2,170 square kilometers (1,348 square miles), it is one of the smallest and most densely populated countries in Africa. Comoros has a growing population, high unemployment, and few natural resources. It is the world’s largest exporter of ylangylang, and one of the largest producers of vanilla. The population of Comoros is 711,400 and growing at 2.84 percent annually. The birth rate stands at 36.35 per 1,000; the death rate is 7.95 per 1,000. Median age is 18.7 years. Life expectancy is 60.37 years for males and 65.15 years for females. Gross national income is $640 a year, with 60 percent living well below the poverty level. It is among the poorest countries in the world, relying heavily on the remittances of 150,000 Comorans who live off the islands. The islands are prone to tropical storms and cyclones. The volcanic Mount Karthala on Grand Comore has erupted several times in recent years, once causing the evacuation of 40,000 residents to protect them from the release of toxic gasses. Volcanic ash has contaminated the rainwater cisterns on Grand Comore and other islands. Malaria, tuberculosis, cholera, and gastrointestinal illnesses are the most common communicable diseases on Comoros. Only 33 percent of the population has sanitary waste facilities, and 86 percent has access to clean water. AIDS is not a major health threat on Comoros. There are believed to be 500 to 1,000 current cases and there have been between 100 and 200 AIDS-related deaths since the virus emerged. Children are especially prone to diarrheal diseases and malaria. Infant mortality is 53 deaths per 1,000; the mortality rate for children between the ages of 1 and 5 is 71 per 1,000. One-third of children are working and one-third marry in adolescence. Literacy rates are low at 64 percent for males and 49 percent for women. The total fertility rate is 4.97 children per woman. Only 26 percent use contraceptives. Seventyfour percent of women receive prenatal care, with 62 percent having a trained assistant during childbirth. The maternal mortality rate is consequently high, with 480 deaths per 100,000 live births. Comoros has limited medical facilities; those with means travel to Mozambique, or even to France, for critical care. Islanders without means often rely on traditional healers. Each island has at least one hos-
Complex Humanitarian Emergencies
pital, but medical staff is limited and facilities are poorly equipped. SEE ALSO: Healthcare, Africa. BIBLIOGRAPHY. Central Intelligence Agency, “Comoros,”
World Factbook, www.cia.gov (cited June 2007); Joint United Nations Programme on HIV/AIDS (UNAIDS), “Comoros,” www.unaids.org (cited June 2007); United Nations Children’s Fund (UNICEF), “Comoros—Statistics,” www. unicef.org (cited June 2007); World Health Organization. “WHO Global InfoBase,” www.who.int/infobase (cited June 2007); World Health Organization, “Guide to Statistical Information at WHO,” www.who.int (cited June 2007).
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Complex emergencies typically occur in the context of already-strained biological, psychological, and social resources in a population. CHEs can occur in both industrialized and developing countries, although the epidemiologic patterns tend to differ. In developing countries, many recent CHEs have resulted from massive movements of people due to violence or the threat of violence. Crude mortality rates are generally high, with most deaths being caused by acute respiratory disease, vaccine-preventable diseases, diarrhea, and malnutrition. These are causes of death that are generally preventable with Complex humanitarian emergencies may cause deaths not just through injury, but also when chronic diseases go untreated.
Heather K. Michon Independent Scholar
Complex Humanitarian Emergencies A complex humanitarian emergency (CHE) is a type of disaster event that is caused by and results in a very complicated set of circumstances usually leading to great human suffering and death. CHEs have become increasingly common due to a variety of factors including war, poverty, environmental destruction and change, growing population density, and an increasing frequency of massive natural disasters. The United Nations (UN) definition of complex emergency is a major humanitarian crisis of a multicausal nature that requires a systemwide response. Commonly, a long-term combination of political, conflict, and peacekeeping factors is also involved. The hallmark of disasters and complex emergencies is the need for external assistance and aid. The man-made or natural events that cause complex emergencies introduce hazards into populations that are both vulnerable and susceptible to those particular hazards. The event then exceeds the capacity of the society to respond and, therefore, demands regional or international assistance. Most often, CHEs result from dramatic events leading to a synergy of hazards including infectious diseases; limited access to food, water and housing; violence; and failing health infrastructure.
access to clean water, adequate food, shelter, and immunization. Children between 0 and 5 years of age are at particularly high risk in these situations. Relatively minor acute events in the setting of chronic violence, political unrest, poor health, and educational infrastructure can result in significant morbidity and mortality. Over 75 percent of world epidemics occur in developing countries at war, where public health practices and infrastructure are not available. In industrialized countries, CHEs usually result from massive natural disasters (e.g., Hurricane Katrina) or from the effects of advanced weaponry on human and physical infrastructure (e.g., former Yugoslavia). These societies usually have high baseline levels of health and education but are overwhelmed by the disaster event. Initially, morbidity and mortality is usually a result of injuries sustained during the acute event. Later, a state of overcapacity or breakdown of the health infrastructure leads to suffering and death from the complications of untreated chronic diseases such as diabetes, heart disease, high blood pressure, and undernutrition. Psychological trauma is a major component of the recovery phase from these events. CHEs demand a complex multimodal response. Responding UN agencies, governments, and nongovernmental organizations must work to rapidly assess the needs of the affected population and meet those specific needs. Several organizations and UN agencies maintain Web sites and staff to assess needs and coordinate these multifaceted efforts.
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In CHEs, infrastructural and logistical coordination are no less important than financial, material, and human resource support. Approaches to CHEs should simultaneously address the immediate effects and the underlying causes of the humanitarian emergency. Many organizations also include development and sustainability in their goals for disaster response. The resilience of a population to the effects of a complex humanitarian emergency has many social and cultural determinants. The key to reducing the impact of CHEs is to address underlying insecurity in the determinants of health before an acute event. Mitigation of morbidity and mortality can be achieved by a robust emergency infrastructure, detailed emergency planning, and strong leadership. SEE ALSO: American Red Cross; International Committee
of the Red Cross (ICRC); International Federation of Red Cross and Red Crescent Societies (IFRC); International Red Cross and Red Crescent Movement (RCRC); Refugee Health; World Health Organization (WHO). BIBLIOGRAPHY. F.M. Burkle, “Complex Humanitarian
Emergencies: A Review of Epidemiological and Response Models,” Journal of Postgraduate Medicine (v.52, 2006); United Nations, www.un.org (cited January 2007); World Health Organization, www.who.int (cited January 2007). Barry Pakes, M.D., M.P.H. University of Toronto
Concussion Although there is no consensus on the definition of a concussion, the committee on head injury nomenclature of the Congress of Neurological Surgeons long ago defined concussion as follows: A clinical syndrome characterized by immediate and transient post-traumatic impairment of neural function, such as alteration of consciousness, disturbance of vision, equilibrium, etc. More recently, the term traumatic brain injury (TBI) has gained popularity, as it more accurately describes the condition. TBI can range from mild, with only brief changes in function, or severe, with prolonged alteration in function and long-term complications.
The number of people who suffer from TBI each year is unknown. The Centers for Disease Control and Prevention state that 1.4 million people in 2004 presented to emergency departments for TBI. Other studies have estimated the incidence of TBI in high school football alone as 250,000 cases annually and that up to 20 percent of players sustain a concussion. Leading causes of TBI are sporting activities, falls, motor vehicle collisions, being struck by or against an object, and assaults. Males are one and a half times as likely as females to suffer TBI; two distinct age groups are more likely to suffer TBI: 0–4 year olds and 15–19 year olds. It is advisable to safeguard against TBI by ensuring athletes wear proper head protection during any competition or training when TBI could occur. Drivers and passengers in motor vehicles should wear seat belts at all times. Homes should be made as fall proof as possible, and to lessen the risk of TBI to infants and children, countertops and furniture edges should be padded and stairways should be blocked. Immediate signs and symptoms of TBI are confusion, amnesia, headache, ringing in the ears, drowsiness, nausea, vomiting, unequal pupil size, convulsions, unusual eye movements, slurred speech, and loss of consciousness. Later, the sufferer may develop poor concentration, irritability, sleep disturbances, personality changes, and fatigue. Management of someone who has sustained a TBI is another area of debate because of the lack of evidence-based data on assessment and outcomes. There have been multiple different guidelines published for the evaluation and management of TBI. It is uniformly accepted that any loss of consciousness warrants transportation to a hospital for further evaluation. If the loss of consciousness is prolonged, the addition of cervical spine precautions and stabilization is warranted, and neuroimaging should be performed at the hospital. If the TBI is thought to be mild, and the sufferer is not immediately evaluated in an emergency department, family members should still be educated on monitoring for delayed symptoms that may need to be evaluated if they occur. Hospital evaluation should include a detailed neurological examination with mental status evaluation. Examination should seek evidence of associated trauma or injuries such as cuts, bruising, or possibly broken bones. Neuroimaging may be performed
Congenital Heart Disease
and includes computerized tomography (CT) scan or magnetic resonance imaging (MRI) scan. The CT scan is the best way to evaluate a serious head injury, as it can accurately diagnose bleeding under the skull or within the brain itself, as well as fractures of the skull bones. The majority of TBI is treated conservatively with bed rest, fluids, and mild pain relievers such as acetaminophen or ibuprofen. Aspirin should be avoided, as it could potentially contribute to bleeding and the use of aspirin in children may lead to serious problems, such as Reye’s syndrome. Ice can be applied to areas of additional trauma, such as an area of swelling where the trauma occurred. If the TBI was suffered during athletic competition or practice, there are multiple different guidelines on return to play criteria. If questions exist on returning to play, it is advised to seek out a TBI specialist or sports medicine physician for final approval. Delayed resumption of activities following TBI is aimed at reduction in incidence of a rare condition termed second impact syndrome. This syndrome was first described in 1973. It occurs most often in athletics, when someone returns to competition before the symptoms of a first concussion have completely resolved. A second episode of trauma to the head, no matter how mild, can result in loss of regulation of blood supply to the brain. This loss of regulation can subsequently lead to vascular engorgement and herniation of the brain. When this occurs, it is usually a fatal condition. There have been 17 reported cases of second impact syndrome since 1992. Post-concussion syndrome is characterized by fatigue, headaches, equilibrium disturbances, and difficulty with concentration. This syndrome may persist for weeks to months after the initial injury. Other dangers following TBI must be considered. There is evidence that cumulative neurological damage can occur with repeated TBI. Even episodes of TBI separated by months or years can lead to permanent neurological damage. There are several well-known examples of boxers suffering from conditions such as “punch-drunk” syndrome. There are many organizations available to those who suffer long-term problems from TBI. National organizations can put victims in touch with local or state resources, such as support groups, healthcare professionals and rehabilitation services.
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See also: Brain Injuries; Head and Brain Injuries; Sports
Injuries.
BIBLIOGRAPHY. R.C. Cantu, “Head Injuries in Sport,” Brit-
ish Journal of Sports Medicine (v.30, 1996); R.C. Cantu, “Second Impact Syndrome,” Clinical Journal of Sports Medicine (v.1, 1998); Centers for Disease Control and Prevention, “Facts about Traumatic Brain Injury,” www.cdc.gov (cited August 2005); Committee on Head Injury Nomenclature of the Congress of Neurological Surgeons, “Glossary of Head Injury Including Some Definitions of Injury to the Cervical Spine,” Clinical Neurosurgery (v.12/386, 1966); J.A. Longlois, W. Rutland-Brown, and K.E. Thomas, Traumatic Brain Injury in the United States: Emergency Department Visits, Hospitalizations, and Deaths (Centers for Disease Control and Prevention, National Center for Injury Prevention and Control, 2004). Rance McClain, D.O. Kansas City University of Medicine and Biosciences
Congenital Heart Disease Diseases that encompass congenital malformations and their respective physiologic disturbances affect nearly 1 in 3,000 or 0.1 to 2 percent of all live births. Genetics and environmental factors contribute to the significant worldwide incidence of these defects. Some of the environmental factors investigated include intrauterine environment, cardiotoxic medications or substances consumed by the pregnant mother, maternal age, and birth order. Low birth weight, folate deficiency, and maternal infection such as rubella are contributory, if not causative, of congenital heart disease in developing nations. Congenital heart diseases caused by malformation can be classified into three discrete groups. Defects causing impaired oxygen transfer from the lungs to the heart, or hypoxemia, include transposition of the great arteries (TGA), tetralogy of Fallot (TF), hypoplastic right-heart syndrome, and critical pulmonary stenosis. Second, those malformations impairing the flow or perfusion of oxygenated blood to the systemic circulation include hypoplastic left-heart syndrome, and coarctation of the aorta (COA). The third classification includes both impaired oxygenation and flow
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of oxygenated blood. These malformations are shunts that divert blood intended for either the pulmonic or systemic circulation, and include patent ductus arteriosus (PDA) and ventricular septal defects (VSD). There are many more malformations such as atrial septal defects (ASD), valvular defects, or single chambers. However, only those occurring with greatest global incidence will be discussed in greater detail. Poor Oxygenation of Blood Transposition of the great arteries is a malformation characterized by anomalous emergence of the aorta from the morphologic right ventricle and the pulmonary artery from the morphologic left ventricle. Oxygen-depleted blood returning from the body enters the superior and inferior vena cavae from the upper and lower extremities, respectively. The deoxygenated blood then enters the right atrium (RA), passes through the tricuspid valve, into the right ventricle (RV). From here, the already oxygen-depleted blood reenters the systemic circulation via the aberrant connection of the aorta to the RV, possibly causing a life-threatening hypoxemia. Likewise, oxygenated blood from the lungs enters the pulmonic vein and passes into the left atrium (LA). The oxygen-rich blood then passes into the left ventricle (LV) via the mitral valve, and due to the aberrant emergence of the pulmonary artery from the LV, further contributes to the patient’s hypoxic state. The only way a neonate might survive with a TGA is by way of an additional malformation that aids in mixing the oxygen-depleted blood with oxygen-rich blood. Among these are ASDs, VSDs, but most importantly, a PDA. In patients with only an ASD, adequate mixing of the blood may not occur due to low atrial pressures; therefore, a PDA may be necessary for further mixing to occur. Because PDAs close completely only after a few days, the clinical presentation of a cyanotic infant may be delayed. However, if a TGA patient is born with a VSD, depending on the size of the defect, extreme cyanosis may not occur until weeks later due to adequate shunting of oxygen-rich blood from the left heart with oxygen-depleted blood in the right heart. This is known as the Taussig-Bing complex. Survival of a neonate with TGA is contingent upon early surgical intervention. However, medical management is required immediately and prior to surgery. This includes maintaining patency of the ductus
arteriosus (DA) with prostaglandins, namely PGE-1. Treated surgically, oxygen-depleted blood from the body is redirected to the mitral valve to flow into the pulmonary circuit and oxygen-rich blood is redirected from the lungs to the tricuspid valve to flow into the systemic circulation via the aorta, known as an atrial baffle repair. This type of surgical correction is only successful with a simultaneous arterial switch repair. This operation accounts for the perfusion of the coronary arteries with oxygen-rich blood, and thus the viability of the heart parenchyma. Further problems in management of TGA patients include congestive heart failure, especially in those with a large VSD. Tetralogy of Fallot affects nearly 6 percent of all patients with congenital heart disease. It has been shown that patients affected by TF are more likely to be afflicted with various extracardiac defects including vertebral, tracheal, esophageal, renal, genital, and ear aberrancies. Commonly characterized by four specific cardiac anatomic abnormalities, a child born with TF may present with little to no cyanosis, a subtle murmur, or more urgently, marked cyanosis. The four anomalies include pulmonic outflow tract obstruction, also known as stenosis or narrowing of the area leading up to the pulmonic valve, with resultant hypertrophy of the RV, an interventricular septal defect, and last, an aorta that overrides the VSD allowing for easy communication of blood from the RV to the aorta. Because of increased left heart pressure in comparison to the right heart, blood moves from the LV through the VSD into the RV. Because the aorta sits over the VSD, both oxygen-rich blood from the LV and mixed-oxygenated blood from the RV can enter it. Thus, patients can survive with these defects and present with only mild cyanosis, if at all detectable. However, during physical activity, increased return to the right heart may reverse the flow of blood through the VSD, from the right heart to the left heart, also known as a right-to-left shunt. In these instances, patients become markedly cyanotic and must rest or assume a knee-to-chest position to ensure adequate delivery of oxygenated blood to the brain and body. In contrast to cyanosis associated with exertion, some patients may experience “tetralogy spells,” which are periods of hypoxemia of unknown cause. The spells typically last 15 to 30 minutes and have been associated with near-total occlusion of the RV outflow tract (RVOT) and are speculated to be
elicited by fright, activity, or injury. As the cyanosis worsens, the patient begins to take shorter, deeper breaths to compensate for the concomitant acidbase changes in the blood. TF can be medically or surgically managed. Medical management of a tetralogy spell entails placement of the child in a knee-to-chest position, which increases blood flow to the lungs and decreases blood flow to the extremities for optimal oxygenation. If a spell occurs within a hospital, intravenous morphine and fluids are given to aid in RV filling. Beta-blockers, which are medications that slow the heart rate, can also be given to relax the RVOT. Associated cardiac and extracardiac abnormalities should also be attended to accordingly, and careful prevention of systemic infection, blood clots, and anemia is advised. Surgical treatment entails either complete repair of all four anomalies or “palliative” anastomoses between the pulmonary and systemic circulatory systems are created to help mix the blood adequately. In a total repair, the VSD is patched, and the area of stenosis in the pulmonary infundibulum is broadened. If a patient is not a candidate for total correction, the Blalock-Taussig procedure has proven to be effective as well. In this procedure, a piece of GOR-TEX® tubing is used to connect the aorta and pulmonary artery, creating a shunt that aids in mixing oxygenated with deoxygenated blood. Poor Systemic Perfusion The prevalence of hypoplastic left heart syndrome is 1.4 to 3.8 percent of infants born with cardiac malformation. This syndrome consists of an underdevelopment of left heart anatomical structures, including the LA, mitral valve (leading to severe mitral stenosis), LV, aortic valve (resulting in aortic atresia), and the aorta itself. Treatment of this syndrome entails maintaining the patency of the DA, followed by early palliative surgical intervention. Coarctation of the aorta makes up 6 to 8 percent of all congenital heart defects and, thus, is one of the most common malformations of all congenital heart defects. There is a 2–5:1 ratio of male to female occurrences. With no familial risk of COA recurrence in subsequent children per se, there is an increased risk of left ventricular outflow tract obstructions in families with a member who has COA. This defect occurs in high incidence with bicuspid aortic valve in which
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the aortic valve has only two leaflets instead of three. It is also a well-known characteristic of the chromosomal disorder Turner’s syndrome or 45 XO. The malformation is characterized by a stricture in the aorta. Most typically, the stricture occurs at the junction of the aortic arch with the descending aorta, either before, immediately opposite, or slightly after the intersection of the DA or the left subclavian artery with the aorta, but can occur anywhere along the aorta’s path. Clinical presentations of this malformation include a rise in blood pressure above the narrowing and a decrease in blood pressure below the narrowing, leading to hypertension, or high blood pressure, in the upper extremities, and hypotension in the lower extremities. However, if the DA is maintained, neonatal COA patients may remain asymptomatic. An important diagnostic finding in infants is a delayed or reduced femoral pulse, when compared to the brachial pulse. Standard studies for infants suspected of COA include electrocardiogram, and a chest X-ray, which may show cardiac enlargement and pulmonary edema with pulmonary venous congestion, all of which are associated with backflow of blood from the constricted aorta into the left heart. Last, a two-dimensional echocardiogram will reveal the site of coarctation and the extent of narrowing. Initial management upon discovery of the COA should include maintaining patency of the DA or reopening it with a prostaglandin, namely intravenous PGE-1. Anticongestive medications should be used to prevent fluid leakage into the lung space. Examples include short-acting inotropic agents such as dobutamine or dopamine, diuretics to encourage urine output, and last, oxygen. If a patient is not a candidate for surgical intervention, a balloon angioplasty can be used to temporarily widen the stricture. There are various surgical procedures that help COA patients, namely resection of the narrowed area, and anastomosing or reconnecting the two free ends of the aorta. Second, a patch aortoplasty works when the aorta opened longitudinally at the coarctation site and a synthetic patch is used to support the previously strictured area. These surgical interventions should be considered urgent when the infant develops congestive heart failure early in life. In young patients with high upper extremity blood pressure, renal function should be assessed because lack of blood flow to
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the kidneys can initiate a cascade of blood pressure– enhancing mechanisms, particularly the renin-angiotensin pathway, exacerbating the heart disease. Shunts A PDA is an abnormally open DA communicating blood from the aorta directly into the pulmonary arteries. Its etiology is suspected to be genetic but is not completely understood. There is a strong familial risk for siblings of patients with PDAs as it occurs with a 2 to 4 percent increased frequency in affected families. Its incidence has markedly risen to .02 to .04 percent among term infants in the past two decades because of decreased infant mortality. It is often detected in premature infants, those born at high altitudes, and those born to mothers infected with rubella during pregnancy. There is a significant association between low birth weight infants and PDAs, and thus, these defects may occur in higher frequencies in developing countries. There is also a correlation between those infants suffering from respiratory distress syndrome (usually preterm infants) and PDAs. Functional closure of the DA normally occurs with the onset of delivery, as the infant takes his or her first breaths of air; complete occlusion of the vessel, however, may take up to one month, especially in preterm infants. A DA that remains patent is thus abnormal as it allows for continued diversion of blood from the systemic circulation to the pulmonary circulation. Depending on the size of the DA and the gestational age at delivery, a patient’s murmur can be a mild systolic murmur or a machine-like holosystolic murmur. A large or nonrestrictive PDA will present in the term infant as respiratory distress, heart failure, and poor feeding. Bounding pulses as well as palpable precordial impulses felt on the anterior chest are also present. In the preterm patient, apnea, which is periods of no respiration, or any respiratory distress should be medically followed for possible PDA. Although diagnosis can be made from physical exam findings, confirmatory tests include echocardiogram, which can reveal the size of the PDA and the degree of shunting, chest X-ray, which may show darkened lung markings and left atrial and/or ventricular enlargement, and last, an electrocardiogram, which can show ventricular hypertrophy. Small PDAs can be medically treated by a nonsteroidal antiinflammatory agent, such as indometha-
cin or ibuprofen. The former is rarely used because it is toxic to the kidneys. These agents block the cox1 and cox-2 pathways that produce prostaglandins, in turn inducing closure of the vessel. The standard of care for premature infants who are unresponsive to indomethacin or ibuprofen treatment is surgical ligation of the PDA. Coil occlusion is an innovative technique that employs a coil inserted into the PDA. The coil serves as a site for embolization that will ultimately completely occlude the vessel. The amplatzer duct occluder is a cone-shaped device that is inserted into the PDA from the aorta. It is effective for patients with large PDAs, but the risk of embolization to the aorta accompanies it. Ventricular septal defects are present in 3 to 6 out of 10,000 live births, and comprise 30 to 60 percent of all congenital heart defects, making them the most common type of CHD. They often accompany other cardiac malformations, most notably truncus arteriosus, where one outflow tract exists for both ventricles, and the double-outlet right ventricle or the Taussig-Bing anomaly. Many types of VSDs exist because of the complex nature of embryological fetal heart formation. A defect in any of the three components of the interventricular septum can result in a shunt upon delivery. The three components are the membranous septum, which lies immediately between the aortic and tricuspid valves; the muscular septum, which comprises the breadth of the interventricular septum; and the conal septum, which lies from between the aortic and pulmonic valves to immediately subjacent to them. Seventy-five percent of VSDs occur in the membranous septum subjacent to the aortic valve and posterior to the tricuspid valve. As discussed above, the resistance from the pulmonary circuit declines drastically within the first week of life, often more rapidly in preterm infants. Therefore, with the LV pumping against resistance from the entire body, and the RV pumping against the low resistance of the lungs, blood is forced from the LV through the VSD into the RV. While some oxygenated blood is lost through the VSD in this left-toright shunt, the body can still be adequately perfused depending on the size of the VSD, and if small, the patient may be asymptomatic. If the defect is 6 to 10 millimeters in diameter, it is classified as a large or nonrestrictive VSD. The pressures between both ven-
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tricles become normalized, and they functionally become one ventricle. The Eisenmenger phenomenon occurs when increases in pulmonary blood flow result in increases in pulmonary vascular resistance. To accommodate the increasing blood volume as well as the increased outflow resistance, the RV hypertrophies. As time elapses, the RV may produce pressures that exceed those of the LV and can ultimately reverse the flow of blood through the VSD, creating a right-to-left shunt. At this point, patients present with mild-to-severe cyanosis and palliative surgical treatment is necessary. SEE ALSO: Adult Congenital Heart Association (ACHA);
American Academy of Pediatrics (AAP); American Heart Association (AHA); Birth Defects; Cardiology; Cleft Lip and Palate; Failure to Thrive; Infant and Toddler Development; Neonatology; Pregnancy and Substance Abuse; Premature Babies; Turner’s Syndrome; World Health Organization (WHO). BIBLIOGRAPHY. Michael A. Barone and Michael Crocetti,
Oski’s Essential Pediatrics, 2nd ed. (Lippincott Williams & Wilkins, 2004); S. Buescher, R.O. Christiansen, and H.W. Taeusch, eds., Pediatric and Neonatal Tests and Procedures (Elsevier Health Sciences, 1996); Kirsten Bourke Dummer and Thomas P. Graham Jr., “Pathophysiology and Clinical Features of Isolated Ventricular Septal Defects in Infants and Children,” www.uptodate.com (cited December 2006); John M. Kissane, Pathology of Infancy and Childhood, 2nd ed. (Mosby, 1975); Grace C. Kung and John Triedman, “Pathophysiology of Left to Right Shunts,” www.uptodate. com (cited December 2006); Myung K. Park, Pediatric Cardiology for Practitioners, 4th ed. (Mosby, 2002); World Health Organization, “Strategic Priorities of the WHO Cardiovascular Disease Programme,” www.who.int (cited December 2006). Priya P. Joshi Chicago Medical School, Rosalind Franklin University
Congo Congo, also known as Congo-Brazzaville, is distinct and independent from its western neighbor, the
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Democratic Republic of the Congo. Once a French colonial holding, the west African state gained independence in 1960 and was for many years a Communist-dominated government. The collapse of the Soviet Union in the early 1990s led to a power struggle and a civil war from 1997 to 1999. A new constitution took effect in 2002. The population of Congo is 3.7 million and growing at a rate of 2.6 percent annually. The birth rate is 42.57 per 1,000 and the death rate is 12.93 per 1,000. Migration is minus 3.62 per 1,000. Over a third of all Congolese live in the capital city of Brazzaville, which has a population of over 1.2 million, and another 700,000 live in the coastal city of Pointe-Noire. The petroleum industry dominates the Congolese economy, followed by lumber, sugar, cocoa, coffee, and diamonds. Insufficient domestic food production has resulted in a dependence on food imports, which most cannot afford. Per capita income in Congo is $750, and almost 35 percent of the population live below the poverty line. Life expectancy is 52.8 years, with healthy life expectancy at 45 for men and 47 for women. Infant mortality is 81 deaths per 1,000. Another 108 children per 1,000 die between the ages of 1 and 5. Maternal mortality is 510 deaths per 100,000 live births. Forty-four percent of women have access to birth control. Eighty-six percent of births are monitored by trained attendants, and 88 percent of women receive prenatal care. Fifty-eight percent of Congolese have access to clean drinking water and only 27 percent have adequate sanitary facilities. This leaves the population at high risk for gastrointestinal diseases, predominantly bacterial diarrhea. Tropical diseases are also common. Malaria is endemic, with 4.3 million cases in 2003 alone, and is among the main causes of mortality in young children. Congo has also faced multiple outbreaks of the Ebola virus since 2001. HIV/AIDS affects 5.3 percent of the adult population, with about 120,000 Congolese currently living with the virus. Women under the age of 35 are more than twice as likely to contract the virus as men. There is little framework for treatment or educational programs and little money for antiretroviral drug therapies. Almost all women receive treatment to prevent mother-to-child transmission of the virus, keeping the number of children younger than 15 with HIV down to about 15,000.
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A medical structure exists on paper but does not function well in practice. Government expenditure on health is $12 per capita per year; the Congolese pay 100 percent of their health expenses out of pocket, and most do not have the available cash. Educational programs are defunct. Hospitals lack equipment, drugs, supplies, reliable power, and adequate sanitation. In the Pool region, home to 180,000 people, there were reportedly only five doctors and two midwives to treat that entire population. The support and assistance of nongovernmental organizations remains critical. SEE ALSO: Congo, Democratic Republic of the; Health-
care, Africa.
BIBLIOGRAPHY. Central Intelligence Agency, “Republic of
the Congo,” World Factbook, www.cia.gov (cited June 2007); Joint United Nations Programme on HIV/AIDS (UNAIDS), “Congo (Republic of ),” www.unaids.org (cited June 2007); Researchafrica.rti.org, “Sub-Saharan Africa–Republic of the Congo,” researchafrica.rti.org (cited June 2007); United Nations Children’s Fund (UNICEF), “Congo–Statistics,” www.unicef.org (cited June 2007); World Health Organization, “Guide to Statistical Information at WHO,” www.who. int (cited June 2007); World Health Organization, “WHO Global InfoBase,” www.who.int/infobase (cited June 2007). Heather K. Michon Independent Scholar
Congo, Democratic Republic of the The Democratic Republic of the Congo (DRC) is the third-largest country in Africa—a huge state the size of western Europe straddling the equatorial heart of the continent. Landlocked except for a narrow strip of territory following the Congo River to its outlet on the Gulf of Guinea, the DRC is mostly covered with the planet’s second-largest rainforest. Five of its national parks have been declared World Heritage sites by the United Nations Educational, Scientific, and Cultural Organization (UNESCO). It is also one of the most war-torn countries in the world. A Belgian colony in the late 19th and early 20th century, the DRC emerged as an independent state
in 1960 and almost immediately spiraled out of control. From 1971 to 1997, the faltering state was known as Zaire. After a rebellion removed dictator Mobutu Sese Seko from power in 1997, the country was renamed the Democratic Republic of the Congo. Almost 4 million Congolese are believed to have died in the war. Despite a new constitution and elections in 2006, the country remains unstable and the United Nations (UN) believes that up to 1,000 people a day are dying in continuing, low-grade combat. The DRC is home to 63 million people, with 250 different ethnic groups and almost as many languages. Little is known about the country’s economy, the rate of poverty and unemployment, or the life of the average Congolese. A third of the population lives in the cities. The capital city of Kinshasha is the thirdlargest city in Africa, with 8.3 million residents. The prevalence of waterborne and vectorborne diseases is very high. Sanitation rates are poor, with 46 percent having access to clean drinking water and 30 percent using adequate sanitary facilities. Bacterial and protozoal diarrhea and hepatitis A are common. Malaria is endemic, accounting for 45 percent of all childhood deaths. Since 2000, the country has suffered severe repeated outbreaks of Marburg hemorrhagic fever, cholera, acute respiratory syndrome, typhoid, plague, and meningococcal disease. It is 11th on the list of 22 counties with the highest rates of tuberculosis (TB), with 366 TB cases per 100,000 people. Life expectancy is low, averaging 50 years for men and 53 years for women. Healthy life expectancy is lower, at 35 for men and 39 for women. Infant mortality is 129 deaths per 1,000 births, and 205 of every 1,000 children die between the ages of 1 and 5. Maternal mortality is also high, with 990 deaths for every 100,000 live births. The DRC was one of the first African nations to implement a HIV/AIDS awareness program when the virus first emerged in the late 1980s, but these efforts were derailed by civil unrest in the mid-1990s. Today, the DRC has an estimated AIDS infection rate of 3.2 percent, with between 500,000 and 2.6 million people currently living with the disease. There are only 184 testing and counseling sites for a country one-quarter the size of the continental United States. Fewer than 7,000 are receiving antiretroviral medications. Efforts to handle the AIDS epidemic and other diseases are hampered by a lack of government funding and a badly broken medical system. Government
Conjunctivitis
expenditures on healthcare are about $4 per capita, or about 4 percent of the Gross Domestic Product. There were approximately 5,800 physicians and 29,000 nurses at work in 2004, and some had not received their government pay for more than 10 years. Governmental medical training schools have closed, and private schools are turning out healthcare workers with inadequate training. Nongovernmental organizations have flooded the country to try to fill in the gaps, but their distribution is uneven and many needy Congolese are going untreated. SEE ALSO: Congo; Healthcare, Africa. BIBLIOGRAPHY. Central Intelligence Agency, “Demo-
cratic Republic of the Congo,” World Factbook, www.cia. gov (cited June 2007); Joint United Nations Programme on HIV/AIDS (UNAIDS), “Congo, Democratic Republic of the,” www.unaids.org (cited June 2007); Researchafrica. rti.org, “Sub-Saharan Africa–Democratic Republic of the Congo” researchafrica.rti.org (cited June 2007); United Nations Children’s Fund (UNICEF), “Congo, Democratic Republic of the–Statistics,” www.unicef.org (cited June 2007); U.S. Agency for International Development, www.usaid. gov (cited June 2007); World Health Organization, “Guide to Statistical Information at WHO,” www.who.int (cited June 2007); World Health Organization, “WHO Global InfoBase,” www.who.int/infobase (cited June 2007). Heather K. Michon Independent Scholar
Conjunctivitis Conjunctivitis is a disease that affects the conjunctiva in the eye, causing it to become inflamed and reddened. It is commonly known as “red eye” or “pink eye” disease. A variety of infecting agents may give rise to the disease and it is their exact nature that determines the severity of the disease, how infectious it is, and how it may be treated. Additional symptoms can include discomfort in the eye, discharge of pus or eyes watering, and eyelids sticking together after sleep. Direct contact with a person suspected of having conjunctivitis should be minimized and washing of hands with soap and water should always be conducted.
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The conjunctiva is a thin membrane that covers parts of the eye and the eyelid. Infections may be caused by bacterial agents such as staphylococci, pneumococci, and sexually transmitted organisms such as gonorrhea infectants. In the last case, the disease requires extensive antibiotic treatments, although other forms are susceptible to lower doses, either applied directly to the infected area or taken orally. Gonococcal conjunctivitis may be passed on to a child during childbirth and can lead to blinding. Babies suspected of suffering from this disease will have a silver nitrate preparation dropped into each eye. Adenoviruses, such as those causing chickenpox or measles, can spread from conjunctivitis to causing respiratory problems. Many different causes apply in different parts of the world. Trachoma, which is the most common cause of blindness in the world and is prevalent in various parts of Africa, Asia, and the Middle East, is caused by the transmission of Chlamydia trachomatis. This form of conjunctivitis leads to scarring of the conjunctiva and, hence, blindness. Medical advice should always be sought when symptoms are observed because of the possibility of severe symptoms or because a case could lead to a very infectious outbreak. When conjunctivitis does occur in the developed world, it tends to lead to a rapidly spreading outbreak that requires identification of all those infected to prevent it spreading further. Conjunctivitis resulting from sexually transmitted diseases is also becoming more prevalent, partly for societal reasons in some countries, and this possibility intensifies the need for medical consultation if presence of the disease is suspected. In some cases, reddening of the eyes might result from the use of some cosmetic or workplace-related substance that has provoked an allergy but does not involve a direct infection. People living in polluted environments such as large cities or in countries in which coal or another type of fuel producing large numbers of air particles is burned in large quantities are subject to a range of possible allergic reactions. The increasing use of chemicals in agricultural production might also stimulate the same effect in some people. It is also possible that another medicine, prescribed or otherwise, has produced such a result. Medical practitioners will wish to question the patient in some detail to identify the exact nature of any allergic response or infection and its cause.
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Methods by which conjunctivitis can spread include direct contact, using the same towel as a person who is infected, or in some cases, the presence of house flies. Clearly, some measure of good hygiene will reduce the likelihood of infection, but is unlikely to remove it altogether. SEE ALSO: Blindness; Chlamydia Infections; Eye Care; Eye
Diseases (General); Gonorrhea; Ophthalmology; Trachoma.
BIBLIOGRAPHY. L. Abbott, “Conjunctivitis,” American
Family Physician (v.57/4, 1998).
John Walsh Shinawatra University
Connective Tissue Disorders Connective tissue is one of four major types of tissue in the body. The four categories are connective, epithelial, muscle, and nervous tissue. Connective tissue includes all those tissues that hold organs together, such as blood, bone, cartilage, and fat. There are many disorders of the connective tissue. Some connective tissue disorders (CTDs) are genetic, some are environmental, and some are idiopathic, meaning they do not have a known cause. Connective tissue fibers run through many organs, holding them together. These fibers are constructed of proteins including fibrillin, collagen, and elastin. As proteins are encoded by genes in the DNA, many genetic diseases affecting connective tissue proteins are found. Genetic CTDs include Ehlers-Danlos syndrome, affecting collagen; Marfan syndrome, affecting fibrillin; and Loeys-Dietz syndrome, typically affecting vascular fibrillin. An environmentally caused CTD is scurvy, which is a disruption of the collagen due to a lack of Vitamin C in the diet. Cancer of a connective tissue is classified as a sarcoma. Some CTDs can have an autoimmune component; that is, the person’s body forms antibodies against its own tissue. The antibodies attack native tissue, leading to inflammation, pain, and sometimes other debilitating symptoms. Common CTDs include soft tissue diseases, or soft tissue rheumatic syndromes. These disorders afflict the tissues surrounding joints; therefore, the
cushioning and mobility functions of the joints may be impaired. Most soft tissue rheumatic syndromes are types of tendonitis. These soft tissue diseases are generally caused by strain, injury, or overuse of a particular joint or muscle. Blood disorders can stem from absent or aberrant abilities to synthesize, mature, or break down blood cells. These disorders may affect red or white blood cells, plasma, platelets, or blood enzymes. A common blood disorder is anemia, which is a reduced amount of blood cells. Many types of anemia can be found; some are genetic, some are nutritional, and others are idiopathic. A famous although very rare blood disease is hemophilia, which is usually found in males. Hemophilia is genetically caused by two main genetic mutations in important blood clotting factors. Hemophiliacs (people with hemophilia) have blood that fails to clot properly; therefore, small cuts or nosebleeds do not heal quickly and severe blood loss can result. Each type of hemophilia is classified as mild, moderate, or severe, depending on how much clotting factor is present in the blood. Bone disorders can be diseases that affect the bone directly, cancer of the bone, or side effects of other cancers. Osteogenesis imperfecta (OI), also know as “brittle bone disease” is a genetic CTD affecting the bones. Another bone CTD, avascular necrosis (AN) is a result of inadequate or completely absent blood supply to the bone. An injury or trauma may have cut off the blood supply; the result is a starved bone that may die. The most common site for AN is at the end of a long bone. Cartilage is also a connective tissue. The three types of cartilage are elastic cartilage, fibrocartilage, and hyaline cartilage. Elastic cartilage is so named because it contains elastin, a yellow-tinted protein. Fibrocartilage can endure high amounts of pressure; thus, it is found between the vertebrae. Hyaline cartilage is named for its glassy appearance. It lubricates joints, among other physiological roles. Because there are multiple forms of cartilage, each with distinct properties and functions, there are many forms of CTDs that affect cartilage. Fat is stored in adipose cells. There are several CTDs involving fat. Some people have genetic mutations in key enzymes or proteins involved in making or breaking down fat tissue. They may look as if they have a metabolic disorder when in reality it is a CTD. With such a CTD, however, a person may develop
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secondary metabolic disturbances. A common CTD involving adipose tissue is a lipodystrophy. Lipodystrophies are characterized by a complete or only partial lack of adipose tissue. In the United States, primary federal funding for research in connective tissue disorders comes from the National Institute of Arthritis and Musculoskeletal and Skin Diseases, part of the National Institutes of Health. SEE ALSO: Bone Cancer; Bone Diseases; Ehlers-Danlos
Syndrome; Marfan Syndrome; Nutrition; Osteogenesis Imperfecta; Vitamin and Mineral Supplements. BIBLIOGRAPHY. Peter Beighton, ed., McKusick’s Heritable
Disorders of Connective Tissue (C.V. Mosby, 1993); Erik Berntorp, et al., Textbook of Hemophilia (Blackwell, 2005); Kenneth J. Carpenter, The History of Scurvy and Vitamin C (Cambridge University Press, 2003); Frédéric de Ceuninck, Massimo Sabatini, and Philippe Pastoureau, Cartilage and Osteoarthritis (Methods in Molecular Medicine) (Humana Press, 2004); Icon Health Publications, The Official Patient’s Sourcebook on Ehlers-Danlos Syndrome: A Revised and Updated Dictionary for the Internet Age (Icon Health Publications, 2002); Gregory R. Mundy, Bone Remodeling and Its Disorders (Taylor & Francis, 1999); Alberto S. Pappo, ed., Pediatric Bone and Soft Tissue Sarcomas (Pediatric Oncology) (Springer, 2005). Claudia Winograd University of Illinois at Urbana-Champaign
Constipation Constipation and its causes are a collection of diseases that are very important to health providers around the entire globe. Constipation is a global health problem affecting more than 12 percent of the entire world (that is, people who have on average less than three bowel movements per week). Constipation means different things to different people. Some consider constipation difficulty passing stool, having hard stool, infrequent bowel movements, or a feeling of partial clearing after a bowel movement. Treatment of symptoms varies depending on region and culture.
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Constipation is twice as common in Americans and in Asian Pacific Islanders as in Europeans. Of the 720 million people who suffer from constipation, one quarter of these people do nothing to try to alleviate their symptoms. These people would rather just wait and hope their symptoms go away by themselves. The main reason for not treating their constipation is myths about what treatments are safe and effective. Some common treatments for constipation in America are the use of dietary fiber, lubricant laxatives, saline laxatives, stool softeners, exercise regimens, surgical procedures, and some prescription medications like tegaserod, lubiprostone, or orlistat. In less Westernized countries, it is more common to treat constipation simply by just changing dietary habits. This includes adding certain foods that may help with constipation. Some of these foods are bananas, honey, pears, prunes, walnuts, pine nuts, seaweed, cabbage, bran, flax seed, licorice root, rhubarb root, dark green vegetables, and other certain chlorophyll-rich foods. A large majority of people with constipation try to first treat their constipation by changing dietary intake, even though it has been shown through extensive research that nutrition and lifestyle do not necessarily affect the incidence of constipation. Increasing dietary fiber and fluids will not necessarily provide effective relief from constipation. One of the safest and most effective treatments of constipation is the use of contact laxatives. Asia Pacific Islanders have one of the highest incidences of constipation in the world (17 percent), and their use of laxatives is one of the lowest; less than 20 percent effectively treat their constipation with laxatives. Americans, on the other hand, who have the highest use of laxatives (40 percent), are still not effectively treating their constipation with useful laxatives. It is up to healthcare providers to give good suggestions on how to treat constipation and to dispel myths about its treatment. There are many different treatments for constipation, just as there are a many different causes of constipation. Constipation is a sign or symptom that can be associated with certain diseases or side effects to medications. Some common causes of constipation in the United States are personal habit (not wanting to use the restroom in public), chronic overuse of stimulant laxatives causing dependence, and pelvic floor dysfunction. Some common medications that cause
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constipation are narcotic pain medications, some antidepressants, some anticonvulsants, iron supplements, some calcium channel blockers, and some antacids. Constipation in other countries is typically caused by certain hormonal disorders, colonic diseases (diabetes, cancer, intestinal obstructions), and some central nervous system diseases. Constipation is a worldwide problem that is easily detectable and treatable, yet there are still a large number of people who live with constipation without any relief. If healthcare providers continuously screened for constipation in routine exams, then gave patients suggestions for treatment, the amount of people who suffer from this problem could be decreased significantly. SEE ALSO: Colonic Diseases (General); Diarrhea; Digestive
Diseases (General); Irritable Bowel Syndrome; Nutrition.
BIBLIOGRAPHY. S.A. Müller-Lissner, et al., “Myths and
Misconceptions About Chronic Constipation,” American Journal of Gastroenterology (v.100/1, 2005); A. Wald, et al., “The BI Omnibus Study: An International Survey of Community Prevalence of Constipation and Laxative Use In Adults,” Digestive Disorders Week (Abstract T1255. May 20–25, 2006). Angela Garner, M.D. University of Missouri–Kansas City
Conventional Medicine Conventional medicine is the name used to describe modern, scientifically grounded medicine. Other names used to describe conventional medicine are allopathic medicine, biomedicine, mainstream medicine, orthodox medicine, regular medicine, scientific medicine, the Hippocratic tradition, or Western medicine. Its practitioners hold degrees such as medical doctor (M.D.), or doctor of osteopathy. There are now many subspecialties such as cardiology, ophthalmology, podiatry, pulmonology, neurological surgery, internal medicine, gynecology, pediatrics, oncology, rheumatology, and others. Allied with conventional medicine are other health professions whose clinicians are licensed to
work with patients. These include registered nurses, physical therapists, physician’s assistants, nutritionists, and others who promote the health and well being of patients. Pharmacists and others also supply drugs or special concoctions for patients with unique needs. Conventional medicine is often called Western medicine in third world countries. It may at times be allied with traditional older medical practices such as Chinese medicine to become complementary medicine. Medical alternatives offered to patients who may be beyond the aid of conventional medicine are called naturopathy. Western medicine uses the scientific method to investigate medical phenomena related to diseases or injuries. The investigations are of the body or of the mind, as in the case of psychology. It also uses the scientific method to develop surgical techniques, drugs, and other instruments for healing. Western medicine began with the Greeks. The writings of Hippocrates and Galen were studied in the ancient world, and they were translated into Syriac in Persia beginning in the 7th century, shortly before the Arab conquests. The Arabs and their other ethnic converts such as the Persians found that Christians and Jews had medical knowledge that was far superior to that which they brought from the desert. The works of the Greek physicians were translated into Arabic, and to this body of knowledge was added the medical knowledge of the Persians and the Hindus of India. During the flourishing centuries of the Islamic empire many Arabic-speaking Moslems, Jews, and Christians preserved and developed medical knowledge. Hospitals were established and medical schools such the one operated by Moses Maimonides in Egypt trained physicians. The Crusades in the Holy Land and the Christian recovery of Spain from the Moors opened opportunities for the transmission of Greco-Arabic medical knowledge into Europe. The medical works were studied and mastered by scholars who served as physicians in an observational and theoretical manner. By the time of the Reformation medical knowledge and practices were changing. The experimental method was advocated by philosophers like Francis Bacon and later by physicians like John Locke. As the experimental method moved medical study away from a scholastic method, it became necessary to
develop instruments for conducting experiments. An alliance between craftsmen and physicians with a classical training in medical knowledge allowed the building of many useful devices for studying diseases and for use in healing. Scientists such as William Harvey studied and came to understand the circulatory system. Artists skilled in developing detailed pictures of the parts of the human body, or of diseases and their symptomatic manifestations, aided the development of medical books and the transmission of a more exact, descriptive science of medicine. The printing industry aided in the circulation of medical books, as did medical societies whose members sought to find forums for the discussion of medical matters. Surgery also came to be allied with classical medical knowledge. Originally barbers or butchers, surgeons augmented their skills with advancing medical knowledge. With the aid of skilled medical craftsmen, new instruments for surgery or for splinting wounds led to increases in the number of people who underwent surgery and lived to tell about it. By the 1800s, medical science continued to develop; however, because it was still very primitive and its success rates were low, a vast array of alternative remedies appeared. Quack remedies, generally useless and often just masking symptoms with combinations of alcohol and opium, were sold by traveling medicine men. Charlatans who offered the sick expensive false hope abounded. Quackery flourished in a number of American states where there were no legal requirements for the practice of medicine. Eventually scientific and practical advances reversed the situation. In the late 1800s, advances in biology and other life sciences revealed the germ theory of disease and opened up the microscopic world. Treatments for some diseases were provided with the development of synthetic dyes. Some of the new sulfur dyes enabled researchers to see bacteria take in the colored dye, which then killed the bacteria but did not harm humans. From these and other discoveries, pharmacology was able to advance beyond traditional herbalism. In the 20th century medicine made huge advances in curing disease. As biology, human anatomy, and other sciences advanced they provided physicians with clearer understandings of anatomy, physiology, pathology, and psychology. Great advances in understanding genetics and then the discovery of DNA led to radical new therapies, including an explosion
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in new synthetic drugs and discoveries of the huge pharmacopeias found in nature. The healthcare industry has grown into a huge enterprise of physicians and other medical workers, hospitals, research institutes, and drug manufacturers, and there have been enormous advances in scientifically engineered technology that includes ultrasound and MRI devices. The work of the scientifically trained physician today is focused on more than just treatment of the signs of disease and symptoms presented by the patient. Modern medicine is the work of a whole community. Physicians and clinical staff, researchers, and others heal, provide comfort care, and encourage alterations in lifestyles, such as new diets for diabetics, that can promote healing. SEE ALSO: Allopathy; Alternative Medicine; Herbal Medi-
cine; Herbalism; Homeopathy.
BIBLIOGRAPHY. Lee Goldman and Dennis Ausiello, eds.,
Cecil Textbook of Medicine (Elsevier Health Sciences, 2003); Lois N. Magner, History of Medicine (CRC Press, 2005); Roy Porter, ed., Cambridge History of Medicine (Cambridge University Press, 2006); Paul Starr, Social Transformation of American Medicine: The Rise of a Sovereign Profession and the Making of a Vast Industry (Basic Books, 1982). Andrew J. Waskey Dalton State College
Cornea and Corneal Disease The cornea is the transparent and protective front part of the eye that allows light to pass through to the retina. With help from the lens, the cornea refracts light and allows the eye to focus. The cornea is made of five layers including the epithelium, Bowman’s layer, stroma, Descemet’s membrane, and corneal endothelium. The epithelium is the outer part of the cornea. It consists of nonkeratinized cells that continuously regenerate. These cells allow minor injuries to the corneal surface to heal rapidly. Many nerve endings exist on the surface of the cornea. The nerve endings protect the eye by stimulating the eye to blink when the eye is touched by a foreign object. Corneal
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epithelium rests on Bowman’s layer. Bowman’s layer provides strength to the cornea and prevents infection. The corneal stroma is the middle layer of the cornea and provides most of the corneal thickness. It consists of parallel bundles of collagen fibrils. The spacing of the collagen fibrils is thought to provide the transparency of the cornea. Beneath the stroma lies Descemet’s membrane, a thin acellular layer that provides a separation between the stroma and endothelium. The corneal endothelium is the final layer of the cornea. It separates the cornea from the anterior portion of the eye. Metabolic exchanges of fluid and solute between the cornea and other parts of the eye occur through the endothelium. Many conditions including infection, trauma, and degeneration can affect the cornea. Signs of corneal disease include pain, tearing, redness, scarring, light sensitivity, and blurred vision. The cornea is examined with a slit lamp. Fluorescein stain is placed in the eye and the stain outlines defects in the epithelium. A local anesthetic is normally also applied to allow visualization. Keratitis is an inflammation of the cornea caused by infection, usually bacterial or viral in nature. Treatment includes artificial tears or antibiotics, depending on the extent of disease. Corneal ulcers can occur after damage to the epithelium. If not treated, they can lead to blindness and impaired vision. Ulcers often appear in the central part of the cornea and can be associated with a hypopyon if severe enough. A hypopyon is a collection of white blood cells in the anterior chamber of the eye. Most ulcers are caused by bacteria, but with injury, fungus must be considered. During examination, the eye is stained with fluorescein and an ophthalmologist will obtain scrapings of the cornea for culture and smears to detect the cause of the ulcer. Treatment includes broad spectrum antibiotics due to the wide variety of potential bacteria. Similar to bacteria, viruses can also infect the eye. The herpes simplex virus that normally causes cold sores can also cause inflammation of the cornea and ulcers. Treatment includes steroids and antiretroviral medications. Herpes zoster, the virus that causes chicken pox, can also cause lesions of the cornea. After a person is exposed to chicken pox, the virus lies dormant in the nerves and can reappear years later. Like herpes simplex, herpes zoster is treated with antiretroviral medications.
Trauma to the cornea often involves a severe decline in vision. Damage of other vital structures can also be associated with this. Urgent surgical treatment is indicated to prevent infection, permanent loss of vision, or loss of the eye. There are many types of degenerative and dystrophic processes that can affect the cornea. They can range from a minor to a very severe impairment of vision. Some of the more common ones include keratoconus, Fuch’s dystrophy, and epithelial basement dystrophy. Occasionally, these disorders may require corneal transplant surgery to improve visual function. SEE ALSO: Antibiotics; Eye Care; Eye Diseases (General);
Herpes Simplex; Ophthalmologist; Shingles (Herpes Zoster). BIBLIOGRAPHY. Peter K. Kaiser, Neil J. Friedman, and Ro-
berto Pineda, The Massachusetts Eye and Ear Infirmary Illustrated Manual of Ophthalmology (Saunders, 2004); Derek Y. Kunimoto, Kunal D. Kanitkar, and Mary S. Makar, The Wills Eye Manual (Lippincott Williams & Wilkins, 2004); Paul Riordan-Eva and John P. Whitcher, Vaughan & Asbury’s General Ophthalmology (McGraw-Hill, 2004); Michael H. Ross, Gordon I. Kaye, and Wojciech Pawlina, Histology: A Text and Atlas (Lippincott Williams & Wilkins, 2003). Komal Bharat Desai, M.D. Independent Scholar Jacquelyn Sturm Independent Scholar
Coronary Disease Coronary disease (CD) is defined as a reduction in blood flow to the heart muscle, usually caused by a narrowing or hardening of its supplying arteries, the coronary arteries. CD has also been called coronary artery disease, coronary heart disease, atherosclerotic coronary artery disease, and ischemic heart disease. It imposes an extensive global health burden, with implications for public health and patient care. CD is the primary cause of heart attack, which is the leading cause of death in Western society. In the Western world, lower incidence has been reported in Mediterranean countries, such as Spain. CD is also
prevalent in the developing world, as over 60 percent of the world’s share of CD is found in those countries. In the United States, approximately 13 million live with CD. In 2003, the Centers for Disease Control and Prevention (CDC) reported that CD was present in 6.6 percent of nondiabetic Americans, and 24.5 percent of diabetics. CD is also the leading cause of premature, permanent disability in the U.S. labor force, accounting for 19 percent of disability allowances by the Social Security Administration. Every year, up to 1.5 million Americans have new or recurrent myocardial infarction, with approximately one-third mortality. Lifetime risk for developing CD in the general U.S. population is also noteworthy: 48.6 percent for men and 31.7 percent for women at age 40; 34.9 percent for men and 24.2 percent for women at age 70. Those with CD are exposed to a significantly greater risk of heart attack, stroke, and other serious complications. In one recent study of 14,062 Americans aged 45–64, the incidence of CD over 7-to-10-year follow-up was 5.1/1,000 person-years in black women, 4.0/1,000 in white women, 10.6/1,000 in black men, and 12.5/1,000 in white men. The normal function of the coronary arteries is to supply the heart muscle with oxygen-rich blood. In CD, the coronary arteries are thickened and occluded by cholesterol plaques, a process known as atherosclerosis. This process is attributed to dietary fat and cholesterol intake, genetic factors, the internal chemical milieu and various patient risk factors, such as smoking status. In myocardial infarction, or heart attack, a cholesterol plaque becomes unstable and ruptures. A blood clot forms and expands, cutting off blood supply to surrounding heart tissues, causing ultimate heart muscle death. As the clot grows, blood supply may be compromised and the area of heart muscle death may spread. This can lead to life-threatening arrhythmias, sudden cardiac death, and congestive heart failure, a reduced pumping function of the heart. Diagnosis and Treatment Signs and symptoms of CD commonly include shortness of breath out of proportion to activity level and chest pain or tightness. With a history of these complaints, further evaluation consists of a thorough history and physical exam, and may include additional
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testing. An exercise stress test is one common study used to evaluate exercise capacity. It consists of running on a treadmill for an extended period of time with the level of difficulty increasing periodically. One other common test is an angiogram, where dye is injected into the blood vessels of the heart in order to visualize any blockages in blood flow to the heart. However, CD may be present even without symptoms. In fact, the disease may have no warning signs. This highlights the importance of appropriate screening, early prevention, and early diagnosis based on risk factors, which are numerous. They are presented below as those that can be modified or managed with lifestyle or medication and those that cannot. Modifiable risk factors are as follows: • Elevated total cholesterol, especially elevated low-density lipoprotein (LDL-C), and reduced high-density lipoprotein (HDL-C) • Diabetes mellitus • Smoking • Obesity and overweight • High blood pressure • Stress • Sedentary lifestyle Nonmodifiable risk factors are as follows: • Increasing age • Male gender • Family history of premature CD (in a male firstdegree relative younger than 55 years, or female first-degree relative younger than 65 years) While each modifiable cardiac risk factor should be individually addressed, and plays an important role in the development of CD, guidelines for primary prevention of CD focus on risk stratification. Based on this, a 35-year-old male with total cholesterol less than 200 mg/dl, HDL-C 50mg/dl, with no history of smoking, diabetes, or high blood pressure would have a relatively low 10-year CD risk of 3 percent. In 20 years, as the same man’s blood pressure creeps up to 140/80, and total cholesterol to 240 mg/dl, his relative risk increases to average, or 16 percent. If the same 55-year-old man were diabetic, his risk would be 25 percent, high compared to his peers. The National Cholesterol Education Program’s Adult Treatment Panel III guidelines recommend ag-
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gressive treatment of cholesterol. This begins with therapeutic lifestyle changes including smoking cessation, stress management, dietary modification, and increased physical activity. The next step is pharmacological treatment. Statins are often used to reduce LDL-C. Nitroglycerin reduces chest discomfort and reduces the heart’s need for oxygen over a short period of time. Beta-blockers and angiotensin-converting enzyme (ACE) inhibitors reduce the risk of recurrent heart attack in those with a history and reduce high blood pressure. Aspirin is also used to reduce the blood’s tendency to clot. Risk equivalents are also considered in CD. This is the concept that if a patient has been diagnosed with one disease, his or her cholesterol and other medical problems should be treated as if he or she has CD. Examples of risk equivalents include history of stroke, diabetes, or peripheral vascular disease. Some have even considered chronic kidney disease a CD risk equivalent. Once the diagnosis of CD or a risk equivalent has been made, it is often appropriate to begin treatment. This is intended to prevent further sequelae of the disease, such as myocardial infarction and heart failure. Treatment can include therapeutic lifestyle change and medical therapy, as mentioned above. However, in those with established disease, further treatment may include a procedure to increase blood flow to the heart. Angioplasty is a procedure in which a balloon or a metal stent is inserted into the blocked artery via wire catheter. Coronary artery bypass surgery is more invasive and requires replacement of one or more blocked arteries in the heart with one from the arm or leg. As discussed, CD poses a burden to society in a multitude of ways, both on public health and on patient care. While there are good ways to treat and control it, recent efforts have focused on primary prevention and risk factor modification, in order to prevent the disease from causing its unfavorable outcomes. SEE ALSO: Arteriosclerosis; Cardiology; Cholesterol; Heart
Attack; Heart Diseases (General); Heart Diseases—Prevention; National Cholesterol Education Program (NCEP). BIBLIOGRAPHY. D.W. Jones, et al., “Risk Factors for Coro-
nary Heart Disease in African Americans: The Atherosclerosis Risk in Communities Study, 1987–1997,” Archives of Internal Medicine (v.162/22, 2002); D.M. Lloyd-Jones, et al., “Lifetime Risk of Developing Coronary Heart Disease,” Lancet
(v.353/9147, 1999); Centers for Disease Control and Prevention, “Self-Reported Heart Disease and Stroke among Adults with and without Diabetes—United States, 1999–2001,” Morbidity and Mortality Weekly Report (v.52/44, 2003). Ross E. Breitbart Philadelphia College of Osteopathic Medicine
Costa Rica Costa Rica is one of the most prosperous countries in the Central American/Caribbean region, with a per capita income of $11,400, making it the 83rd-richest nation in the world. Consequently, the population of 4,075,261 derives the benefit of comparatively high health and social indicators. The United Nations Development Programme Human Development Reports rank Costa Rica 48th among 177 countries on general quality-of-life issues. Despite this relative prosperity, poverty is high at 18 percent; 2 percent of Costa Ricans subsist on less than $1 a day. Current unemployment is reported at 6.6 percent of the workforce. The government is committed to poverty reduction and has established a safety net to protect the most vulnerable segments of the population. While a fifth of the population remains engaged in agriculture, the Costa Rican economy has diversified, and the technology and tourism industries are expanding. This diversification has deepened the divide between the rich and the poor, and Costa Rica ranks 46.5 on the Gini index of inequality. The poorest segment of the population claims only 1.1 percent of the country’s resources while the richest 10 percent share 36.8 percent of the resources. Healthcare in Costa Rica is guided by the National Health Plan instituted in 1998, which expanded the General Law on Health through a series of reforms. The goals of these reforms are concentrated on maintaining universal health coverage, narrowing existing gaps in access to health services, and improving the quality and efficiency of the healthcare system. Government spending on health is high, with 21 percent of the national budget designated for healthcare. The government allots 7.3 percent of the Gross Domestic Product (GDP) for health expenses and earmarks $616 (international dollars) per capita to healthcare.
Côte d’Ivoire
Nearly 80 percent (78.8 percent) of all health funding is derived from government sources, and 88.6 percent of these funds are used to provide social security. The private sector is responsible for 21.2 percent of health expenditures, and out-of-pocket expenses account for 88.70 percent of private spending. There are 1.32 physicians, 0.92 nurses, 0.01 midwives, 0.48 dentists, and 0.53 pharmacists per 1,000 population in Costa Rica. Literacy is high in Costa Rica at 96 percent. Around 90 percent of children attend primary school, but only 62 percent are enrolled in secondary school. One-half of all children between 5 and 14 are in the workforce. Life expectancy is 77.02 years, with females outliving males by an average of five years. All urban residents and 92 percent of rural residents have access to safe drinking water. Conversely, 97 percent of rural residents have access to improved sanitation, but only 89 percent of urban residents have such access. Each Costa Rican woman gives birth to an average of 2.24 children. Eighty percent of women use some method of birth control even though 76.3 percent of the population are Roman Catholic. Only 2 percent of all births occur outside the care of a skilled attendant, and 70 percent of women receive prenatal care. The adjusted maternal mortality rate is 43 deaths per 100,000 live births. Extensive efforts are under way to reduce maternal death rates, and teen mothers are a particular focus of attention. Special attention is also directed toward women in the provinces of Limón and San José. Costa Rica has been successful in reducing the infant mortality rate, which currently stands at 9.7 deaths per 1,000 live births. Between 1990 and 2004, infant mortality dropped from 16 to 11 deaths per 1,000 live births, and under-5 mortality was reduced from 18 to 13 deaths per 1,000 live births. Seven percent of infants are underweight at birth, and 5 percent of under-5s are moderately underweight. Two percent of under-5s suffer from moderate-to-severe wasting diseases, and 6 percent experience growth stunting. The Costa Rican government subsidizes all required vaccinations. Thus, immunization rates are relatively high. Ninety percent of children are vaccinated against tuberculosis; diphtheria, pertussis, and tetanus (DPT3); polio; and Haemophilus influenzae type B. Infants receive DPT1 and hepatitis B (89 percent) and measles (88 percent) vaccinations at lower levels. In common with other areas of Latin America, Costa Rica is experiencing major health problems
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related to incidences of HIV/AIDS. With an adult prevalence rate of 0.6 percent, 12,000 Costa Ricans are living with this disease. Nine hundred others have died from the disease or its complications. SEE ALSO: Healthcare, South America. BIBLIOGRAPHY. Central Intelligence Agency, “Costa
Rica,” World Factbook, www.cia.gov (cited January 2007); Commission on the Status of Women, “Costa Rica,” www. un.org/womenwatch (cited January 2007); Manuel Antonio Garretón, et al., Latin America in the Twenty-First Century: Toward a New Sociopolitical Matrix (NorthSouth Center Press, 2003); Carlos Gerardo Molina and José Nuñez del Arco, eds., Health Services in Latin America and Asia (Johns Hopkins University Press, 2001); Pan American Health Organization, “Costa Rica,” www.paho. org (cited January 2007); Juan Diego Trejos, “Costa Rica: The State’s Response to Poverty,” in Dagmar Raczynski, ed., Strategies to Combat Poverty in Latin America (Inter-American Development Bank, 1995); United Nations Children’s Fund (UNICEF), “Costa Rica,” www.unicef.org (cited January 2007); World Bank, “Costa Rica Data Profile,” devdata.worldbank.org (cited January 2007); World Health Organization, “Costa Rica,” www.who.int (cited January 2007). Elizabeth R. Purdy, Ph.D. Independent Scholar
Côte d’Ivoire Côte d’Ivoire (sometimes called the Ivory Coast) is located in western sub-Saharan Africa on the Gulf of Guinea between Liberia and Ghana. For many years, it was looked upon as the economic jewel of the region and was among the world’s leading exporters of coffee, cocoa, and palm oil. However, in 2002, armed conflict broke out between the government and the Forces Nouvelles (FN). This ongoing struggle for control led to the implementation of an internationally monitored “confidence line” between the FN in the north and the government in the south. Now trapped in a situation described as “no peace, no war,” millions of Ivoirians have faced displacement and abuse as the nation’s economy and infrastructure have fallen into ruin.
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The population of Côte d’Ivoire is 17.7 million and growing at 2.03 percent annually. The birth rate is 35.11 per 1,000 residents and the death rate is 14.84 per 1,000. Only 45 percent of the population live in urban areas. Life expectancy at birth is extremely low, at 41 years for males and 47 years for females. Healthy life expectancy is 37 years for men and 41 years for women. Infant mortality is high, with 117 deaths per 1,000 live births. Maternal mortality is 690 per 100,000 live births. In 2004, the United Nations Children’s Fund (UNICEF) estimated that 68 percent of women had the services of a trained attendant at birth, and that percentage may have dropped as the civil unrest has continued. The average Ivoirian woman gives birth to 4.5 children; only 15 percent of women use birth control. The condition of Ivoirian children is dire. Only 50 percent are immunized against common childhood illnesses; in the north, most immunization programs were entirely shut down until UNICEF and other aid organizations moved in. The mortality rate for children between the ages of 1 and 5 years rose from 157 per 1,000 children in 1995 to 194 per 1,000 in 2004— among the highest mortality rates in the world. Between the AIDS epidemic that has gripped the country over the last decade and ongoing civil war, there are an estimated 940,000 orphans under the age of 17. An estimated 3,000 children are serving as soldiers. Millions have been displaced. All of these factors leave children vulnerable to physical and sexual abuse and exploitation. Female genital mutilation is practiced in Côte d’Ivoire, with an estimated 39 percent of urban females and 48 percent of rural females having been cut in this way. The most common procedure is type II, defined as the removal of the clitoris and all or part of the labia minora. The country’s infrastructure has failed or fallen into disrepair, and at best 84 percent of the population has access to clean water and 40 percent have sanitary waste disposal. This has contributed to severe outbreaks of cholera and typhoid in the past two years. Malaria is common, as is yellow fever; hepatitis A, B, and E; schistosomiasis; and trypanosomiasis (sleeping sickness). There have been Ebola outbreaks within the country, although none in recent years. Current figures are difficult to come by, but the best estimates put the prevalence of human immuno-
deficiency virus (HIV)/AIDS at 7 percent, with an estimated 570,000 Ivoirians infected and 47,000 deaths. Among those with the virus are some 40,000 children, and the disease has left 310,000 orphans. The medical establishment has almost completely collapsed since 2002, leaving 60 percent of the population without healthcare. International aid groups, led by Médecins Sans Frontières (Doctors without Borders), have reopened some hospitals and instituted mobile clinics to try to bring help to those in need. SEE ALSO: Healthcare, Africa.
Central Intelligence Agency, “Côte d’Ivoire,” World Factbook, www.cia.gov (cited June 2007); Joint United Nations Programme on HIV/AIDS (UNAIDS), “Côte d’Ivoire,” www.unaids.org (cited June 2007); Researchafrica.rti.org, “Sub-Saharan Africa—Côte d’Ivoire” researchafrica.rti.org (cited June 2007); United Nations Children’s Fund (UNICEF), “Côte d’Ivoire—Statistics,” www.unicef.org (cited June 2007); World Health Organization, “Guide to Statistical Information at WHO,” www.who.int (cited June 2007); World Health Organization, “WHO Global InfoBase,” www.who.int/infobase (cited June 2007). BIBLIOGRAPHY.
Heather K. Michon Independent Scholar
Craniology Craniology, often called craniometry, is the study of the skull or cranium, and the word is derived from Latin. Research has varied from the measuring of the skull to provide information for anthropologists or about evolution, to pseudoscience with people trying to use head shapes and sizes for phrenology, to medical treatment for people who have suffered head injuries. The measuring of skulls for anthropological information is usually known as craniometry, and is important for anthropologists and ethnologists. The Swedish professor of anatomy Anders Retzius established the use of a cephalic index for physical anthropology for the classification of ancient human remains, especially skulls, found by archaeologists in Europe. Retzius defined skulls as dolichoce-
With his 1981 book The Mismeasure of Man, Stephen Jay Gould debunked 19th-century craniology and similar scientific racism.
phalic, brachycephalic, and mesocephalic. This led to Georges Vacher de Lapouge describing the skulls in such a way as to classify them to help espouse his ideas on eugenics. He made divisions between the different races, and also between several types of Aryans. His ideas were taken up by William Z. Ripley in The Races of Europe (1899), leading to interest being expressed in them by racists in Nazi Germany. Similar ideas were espoused by Pieter Camper, who tried to compare skulls of different races to help find a scientific basis for racist theories. There were also a number of ideas put forward by Samuel George Morton, who compared skulls from around the world and tried to work out the different brain capacities, with his work being highlighted by Josiah C. Nott and George Gliddon in Types of Mankind (1854). However, Morton’s work has since been scientifically demolished by the American paleontologist and historian of science Stephen Jay Gould, whose book, The Mismeasure of Man (1981), showed that Morton had “cheated” on many occasions to obtain the statistics he published. The study of skulls by the German-born Franz Josef Gall led in a similar direction at first. Gall started work as a medical doctor but became interested in
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what he called “canioscopy”—the study of skulls or heads. For the most part, he worked only with skulls, putting together a large collection that is now held at the Rollet Museum in Baden bei Wien, Austria. He first used these to propound the inferiority of blacks and also the Irish, the latter leading to the popularity of his work in England, although his work was criticized by the Roman Catholic Church and the Austrian government where he was working. Gall soon started developing what was to become phrenology, by which people sought to be able to determine the character of a person by the shape of his or her skull. It was believed by many at the time that some people were born evil, and this could be shown in the shapes of their skulls. The result was that in 19th-century North America and in Victorian Britain, scientists visited prisons where they measured and modeled the heads of criminals, even going so far as collecting skulls from men and women who were executed to try to come up with some evidence for the shape of a “criminal” head. Today, the idea of using skulls to provide a scientific justification for racism has been rejected and phrenology deemed a pseudo-science, with conclusions of no scientific worth. However, the study of skulls during the 18th and 19th centuries did lead to the collation of large amounts of data and some discoveries about the skull that form the basis of modern craniology, which largely deals with fractures. SEE ALSO: Brain Injuries; Brain Malformations; Fractures;
Head and Brain Injuries; Head and Brain Malformations.
BIBLIOGRAPHY. G. Hauser and G.F. de Stafano, Epignetic
Variants of the Human Skull (E. Schweizerbart’sche Verlagsbuchhandlung, 1989); Folke Henschen, The Human Skull: A Cultural History (Thames & Hudson, 1966); William W. Howells, Cranial Variation in Man: A Study by Multivariate Analysis of Patterns of Difference among Recent Human Populations (Peabody Museum of Archaeology and Ethnology, Harvard University, 1973); Marta Mirazón Lahr, The Evolution of Modern Human Diversity: A Study of Cranial Variation (Cambridge University Press, 1996); Spencer L. Rogers, The Human Skull: Its Mechanics, Measurements and Variations (Thomas, 1984). Justin Corfield Geelong Grammar School, Australia
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Crick, Francis Harry Compton (1916–2004) Francis Crick was an English physicist and molecular biologist who discovered the structure of the DNA molecule in 1953 together with James D. Watson and Maurice Wilkins. With them, he was awarded the Nobel Prize in Physiology or Medicine in 1962 for the relevance of their discovery in furthering the understanding of information transfer in living material. Francis Crick was born on June 8, 1916, in Northampton, United Kingdom, the eldest son of Harry Crick and Annie Elizabeth Wilkins. His family, who owned a shoe factory, was extremely religious, but Francis was drawn from a very early age to scientific explanation rather than religious dogmas. He first attended Northampton Grammar School, then at age 14 obtained a scholarship to study mathematics, physics, and chemistry at Mill Hill School in London. He later studied physics at University College, London, from where he graduated with a B.Sc. in 1937. Crick started a Ph.D. on the viscosity of water at high temperatures under Professor Edward Neville da Costa Andrade. His postgraduate studies were interrupted by World War II. During the war, Crick worked at the Admiralty Mining Establishment devising new magnetic and acoustic mines that defied German minesweepers. After the war, Crick started to study biology, making a decisive transition in his career. Supported by a Medical Research Studentship, Crick worked at the Stangeways Laboratory in Cambridge where he researched the physical properties of cytoplasm. In 1949, Crick joined the Medical Research Council Unit led by M.F. Perutz at the Cavendish Laboratory in Cambridge where he started the research that would eventually earn him the Nobel Prize. A year after joining the Cavendish Laboratory, Crick again became a research student, enrolling for a Ph.D. at Caius College, Cambridge, and studying X-ray diffraction. These were intellectually challenging years for Crick, who had to learn the elements of organic chemistry and crystallography. While at Cambridge, Crick met James Watson and the two became close friends. Their friendship led to common research interests and, eventually, to their theory of the double-helical structure of DNA in 1953
and their description of the structure of small viruses. The hypothesis of the DNA helix was followed by an enduring controversy with King’s College, London, as Maurice Wilkins, who had worked there, joined Crick and Watson. Wilkins showed them X-ray diffraction images originally produced at King’s College by himself, Raymond Gosling, and Rosalind Franklin. These images proved to be crucial in Crick and Watson’s discovery as they were evidence of the helical structure of DNA. In the 1960s, Crick worked in the fields of biochemistry and genetics, stimulating research in protein synthesis, the genetic code, and on acridine-type mutants. Crick is closely identified with Cambridge University. However, he lectured in many universities, including Harvard. In 1977, he left Cambridge, refusing the Mastership of Gonville and Caius College after it had been offered to Italian geneticist Guido Pontecorvo, who had also refused. Crick then went to work at Salk Institute for Biological Studies in La Jolla, California, where he had been a nonresident fellow since 1960 and had spent his sabbatical from Cambridge in 1976. At the Salk Institute, Crick began the second part of his career which has received less attention than the first. There, he specialized in neuroanatomy and neuroscience, which in the 1980s became his main field of research. Crick was struck by the many different and unconnected disciplines in neuroscience and by the consideration of consciousness as a taboo. He hoped to encourage interactions between the different disciplines of neuroscience to address the issue of consciousness. In his investigations, Crick worked with the philosopher Patricia Churchland and neuroscientist Christof Koch. Crick and Koch focused in particular on how the brain produces visual awareness a few hundred milliseconds after viewing a scene. Crick challenged computational models describing how the brain worked, as they were not based on observations of brain structure and function. Crick received many awards and honors during his career. He was made a Fellow of the Royal Society in 1959. In 1962 he was elected a Foreign Honorary Member of the American Academy of Arts and Sciences. He was awarded the Prix Charles Leopold Meyer of the French Academy of Sciences in 1961, and the Award of Merit of the Gairdner Foundation
Croatia
in 1962. With the codiscoverers of DNA structure Watson and Wilkins, he was given a Lasker Foundation Award in 1960. Crick was elected a fellow of the Committee for the Scientific Investigation of Claims of the Paranormal in 1983 and a Humanist Laureate of the International Academy of Humanism in the same year. Crick did not isolate himself in his laboratory away from wider social issues. In 1987, concerned that some of his research on the genetic code might be used to support creationism, Crick publicly joined a group of Nobel Prize winners demanding a ban on teaching creationism in schools. He also spoke in favor of the establishment of Darwin Day as a national British holiday. In 1995 the scientist endorsed the Ashley Montagu Resolution demanding an end to the genital mutilation of children. He was also one of the founding members of SOMA, an organization that tried to prevent the criminalization of cannabis. Crick died of colon cancer on July 28, 2004, at San Diego Thorton Hospital, California. As he requested, he was cremated and his ashes were scattered in the Pacific Ocean. His memory is honored with the Francis Crick Prize Lectures at the Royal Society, London, and the Francis Crick Graduate Lectures at the University of Cambridge. SEE ALSO: Avery, Oswald Theodore (1877–1955); Base
Pair; DNA; Genetic Code; Watson, James.
BIBLIOGRAPHY. Francis Crick, What Mad Pursuit: A Per-
sonal View of Scientific Discovery (Basic Books, 1990); Edward Edelson, Francis Crick and James Watson: And the Building Blocks of Life (Oxford University Press, 2000). Luca Prono Independent Scholar
Croatia Croatia is located on the Balkan Peninsula, with a coastline on the Adriatic Sea, adjacent to Italy. It is one of the new states to emerge from the dissolution of the former Yugoslavia in the 1990s. The long period of civil war did tremendous damage to the region’s infrastructure, and the economy is struggling to rebound.
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Foreign investment has increased, and the picturesque countryside now draws up to 6 million tourists a year. The population is 4,493,000. The death rate of 11.57 per 1,000 is higher than the birth rate of 9.63 per 1,000, with the population declining by 0.035 percent annually. Median age is 40.6 years. Life expectancy is 71.26 years for males and 78.75 years for females. Gross national income is $8,060 per person, with a total poverty rate of 11 percent. Most Croatians work in industry or services, with less than 3 percent working in agriculture. Unemployment is between 14 and 17 percent. Mortality from communicable disease is just 1 percent annually. All Croatians have access to clean water and sanitation. HIV/AIDS prevalence rate is less than 0.1 percent. In 2006, there were 54 new HIV cases, 16 new AIDS cases, and 6 AIDS-related deaths. Croatia has some of the lowest rates of sexually transmitted disease infections in Europe. Tuberculosis also has a low prevalence, with 31 new cases per 100,000 people. Croatians have several risk factors for the development of noncommunicable disease. About 30 percent smoke daily. About 17 percent of males and 15 percent of females are obese. Physical inactivity and low consumption of fruits and vegetables are common. Cardiovascular disease is the leading cause of mortality in Croatia, causing 53 percent of all deaths. Ischemic diseases account for 20 percent of deaths and cerebrovascular disease for 16 percent. Cancer is responsible for 23 percent of deaths. Alcohol consumption is also high, averaging 11 liters per person per year (compared with an average 9.4 liters in other parts of the European Union [EU]). This is believed to be a contributory factor in many unintentional accidents, especially road accidents. Mortality from unintentional accidents is 58 per 100,000, higher than the EU average. Traffic injuries are also higher, at 384 per 100,000, compared with the EU average of 297 per 100,000. Neuropsychiatric disorders affect about 2 percent of the population. Mortality from suicide or self-inflicted causes is 20 deaths per 100,000, about two times higher than the EU average. Children’s health has rebounded from the war years, and child mortality has dropped to about 6 deaths per 1,000 for children under 5. All but 4 percent of children are immunized for all major vaccine-
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preventable diseases. Malnutrition rates are negligible, but obesity is becoming more common among the young. Although the exact number is not known, there are a large number of Croatian children living in orphanages and state-run institutions. A recent public service campaign by the government has been successful in getting children into foster homes. Croatia has one of the lowest teen pregnancy rates in Europe. Abortion rates for women overall have dropped sharply since the prewar years, falling from 882 abortions per 1,000 live births in 1985 to 295 abortions per 1,000 live births in 1997. The total fertility rate is 1.41 children per woman. Maternal mortality is just 8 deaths per 100,000 live births. The Croatian medical system is a mix of public and private, with most people entering the health system through private general practitioners or clinics, while all hospitals, teaching hospitals, and health institutes are run by the state. In a move to decentralize, many health centers, polyclinics, home-care agencies, and other local facilities are now run by county governments rather than the state. Croatia has an adequate ratio of medical personnel to citizens, and offers a wide range of specialized medicine within the country. However, specialized services tend to be centralized in the large cities, which can put a travel burden on those in need. Long waits for treatment are not unusual. Health insurance is compulsory, with those who cannot afford coverage (or do not receive it through employment or other means) getting basic coverage through the Croatian Institute for Health Insurance. SEE ALSO: Bosnia and Herzegovina; Healthcare, Europe;
Serbia and Montenegro.
BIBLIOGRAPHY. Central Intelligence Agency, “Croatia”,
Crossing Over Crossing over is the reciprocal exchange of segments of DNA between chromatids of homologous chromosomes. Sometimes referred to as recombination, crossing over is a characteristic of prophase in the first meiotic division. Normal crossing over is a major source of genetic variation in human reproduction and is used by researchers to help identify the relative location of genes. Errors in crossing over are a common source of mutation. In the absence of crossing over, germ cells would contain chromosomes that were identical to those of ancestors. It would, in theory, be possible to directly trace a single chromosome back generations. In the extreme case, there would only be a handful of distinct chromosomes, altered only by acquired mutations over the years. Instead, during meiosis, homologous chromosomes approach each other and exchange sequences of DNA, thus making the chromosomes of germ cells slightly different from those of the surrounding somatic cells. Because this transfer of genes occurs by the physical breaking and transfer of DNA, scientists can draw inferences from the frequency with which certain traits tend to cross over. First, they can conclude that two traits that are often seen together are likely caused by genes that lie in close proximity to each other. Genes that are close together on a chromosome are likely to travel together when a crossing over event occurs. Scientists can also conclude that traits encoded by genes that cross over frequently are encoded by genes located at the ends of chromosomes as opposed to loci near the center of the chromosome. SEE ALSO: Acquired Mutation; DNA.
World Factbook, www.cia.gov (cited July 2007); Joint United Nations Programme on HIV/AIDS (UNAIDS), “Croatia,” www.unaids.org (cited July 2007); World Health Organization, “Croatia: 10 Health Questions About the New EU Neighbors,” www.euro.who.int (cited July 2007); World Health Organization, “Highlights on Health: Croatia,” www.euro.who.int (cited July 2007); United Nations Children’s Fund (UNICEF), “Croatia—Statistics,” www.unicef .org (cited July 2007).
BIBLIOGRAPHY. R.L. Nussbaum, et al., Thompson &
Heather K. Michon Independent Scholar
Crossover studies, sometimes referred to as casecrossover studies, are a type of clinical trial design
Thompson: Genetics in Medicine, 6th ed. (Saunders, 2004).
Bimal P. Chaudhari Boston University
Crossover Study
where a participant experiences both the intervention and control aspects of the study. Participants are first randomized into either the intervention or control arms of a study for a previously determined amount of time and observed. After that time has concluded, these participants essentially “cross over” into another arm of the study, thus serving as their own controls in the study. This type of study is appealing because of its efficiency and precision. Crossover studies are efficient because participants are used more than once. The benefit with this fact is that the required number of participants that a study would need to recruit can be much less than that of a simple parallel trial. The number of participants is commonly referred to as a study’s sample size. The sample size, along with a few other factors, directly influences the statistical significance of any measurable outcome difference. The lower the sample size is in a study, the greater the likelihood that the measured outcome will lack statistical significance. Crossover studies may also provide an increase in the precision of the study because treatment comparisons occur within the same individual, which may reduce the normal variability that exists within two human beings. Although the theory behind crossover studies has been established for many years, the main assumption related to this type of design, which makes them unpopular in many practical circumstances, is the fact that there must not be any therapeutic carryover from the previous treatment. If there is any residual effect present, then this effect must be eliminated before the next treatment can begin. This becomes an even more difficult scenario when there are multiple treatments. In order for a crossover study to provide valid results, without any residual effects, there must also not be any exogenous changes over time that may alter the state of the patient. Any changes, whether they are seasonal changes, changes in a participant’s comorbidities, or changes that may influence the participant’s adherence to the trial, could greatly alter the results of the trial. Therefore, when designing or reviewing a crossover study design, the following criteria should be kept in mind when determining the appropriate use of a crossover clinical trial design: 1.) The participant’s first allocation has not had any long-lasting effects that could alter any of the subsequent interventions; 2.) if therapeutic effects do carry over, then the wash-
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out period has been sufficient enough to eliminate these effects before the second intervention can begin; 3.) exogenous or secular changes over time have not influenced the possible outcome of the trial. SEE ALSO: Case-Control Study; Clinical Trial; Cohort
Study; Cross-Sectional Study; Randomized Clinical Trial.
BIBLIOGRAPHY. National Institutes of Health, “An Introduction to Clinical Trials,” www.clinicaltrials.gov (cited October 2006).
Jose Lozada Independent Scholar
Cross-Sectional Study The cross-sectional study is an observational study design that examines a representative group of individuals at a specific point or short segment in time. These studies are often performed to gather “snapshot” information regarding prevalence of disease, condition, or exposure. Cross-sectional studies are used primarily for descriptive or surveillance purposes that do not require them to be hypothesis driven. Cross-sectional studies are occasionally used to investigate exposure–outcome relationships, but this kind of interpretation of cross-sectional data should only be done cautiously. Cross-sectional studies have the advantage of being relatively inexpensive, and the sampling frame can sometimes be selected to be specific to study a particular question. These studies do not suffer from loss to follow-up as longer, time-dependent studies do. Cross-sectional studies are frequently used to examine prevalence of disease or condition. The duration or severity of disease, however, might result in a number of issues: For example, diseases or conditions of long duration might be overrepresented, while diseases of very short duration might be missed because of the short window during which the study is conducted. Cross-sectional studies should be used only cautiously to support exposure–outcome relationships. Drawing conclusions regarding etiology based on cross-sectional information is difficult for a number of reasons, most due primarily to the inability of
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such studies to establish temporality. Causality might be inferred in specific circumstances: when the exposure is a permanent characteristic that certainly preceded the outcome of interest, or when the exposure occurs immediately before the disease or condition in question. Even so, without other biological or epidemiological evidence of an exposure’s relationship to the disease or condition, it becomes difficult to determine whether the exposure has a causal, mediating, moderating, or even mitigating effect on the outcome. Because longitudinal cohort studies have an element of temporality, they are considered better suited for the purposes of establishing causation. Issues of confounding (or the differential distribution of nonexposure factors associated with the outcome) must also be taken into consideration in evaluation association. A last disadvantage of these studies is their vulnerability to selection bias. Segments of the population might be more or less difficult to survey cross-sectionally. The researcher should consider this issue in his or her sampling framework. SEE ALSO: Case-Control Study; Epidemiology.
In emergency situations, CMR is usually expressed in deaths per 10,000 population per day. The baseline CMR in developed countries is approximately 0.25 deaths per 10,000 population per day, whereas in the least developed countries, it is 0.38, and in sub-Saharan Africa, it is 0.44 deaths per 10,000 per day. CMR is a useful measure in describing and evaluating the conditions of populations of refugees or internally displaced persons, and measuring the success of interventions. Generally, a doubling of the baseline CMR indicates a health emergency. When the baseline rate is not known, CMR exceeding one death per 10,000 population per day it is considered a humanitarian emergency. For example, in Goma, Zaire, CMR ranged from 27 to 50 among refugees fleeing the violence in Rwanda in the first month after their arrival. The rate decreased dramatically once the population movement ceased and relief became available and organized. Increased CMR can reflect the poor condition of refugees, availability of food in a refuge camp, violence, or other factors. Relief efforts are usually aimed at reducing CMR to less than one or to less than twice the baseline rate documented for the population prior to the disaster.
BIBLIOGRAPHY. Kate Ann Levin, “Study Design III: Cross-
SEE ALSO: Death Rate.
Sectional Studies,” Evidence-Based Dentistry (v.7, 2006); Kenneth Rothman and Sander Greenland, eds., Modern Epidemiology (Lippincott Williams & Wilkins, 1998).
Constance W. Liu, M.D. Case Western Reserve University
BIBLIOGRAPHY. M. Merson, R. Black, and A. Mills, Inter-
national Public Health: Diseases Programs, Systems and Policies (Jones and Bartlett, 2006); Sphere Project Handbook, www.sphereproject.org (cited September 2006). Barry Pakes, M.D., M.P.H. University of Toronto
Crude Mortality Rate Crude mortality rate (CMR) refers to the number of people who die per 1,000 persons in a population in a specific amount of time, usually one year. In a country such as Canada, CMR is approximately seven deaths per 1,000 population per year. CMR is a simple measure and a relatively easy health statistic to gather and calculate. It is used to gauge health status in developing countries, particularly in emergency situations, when other data are not available. CMR data may be gathered from burial site surveillance, population surveys, or other hospital or administrative records.
Cryopreservation Cryopreservation, which derives from the Greek word cryo for “icy cold,” is a process whereby cells and sometimes whole tissues are preserved by cooling to very low subzero temperatures, often 77 K or minus 196 degrees C, the boiling point of liquid nitrogen. This is because at these very low temperatures any biological activity is effectively stopped, including those biochemical reactions that might lead to cell death. The problem is often that the act of freezing the cells at such low temperatures may seriously damage the cells.
Cryosurgery
In addition, there can be problems with the high concentration of solutes, such as salt, in nonfrozen solution during freezing. Another problem encountered is too much extracellular ice, which can be fatal to some cells. It can cause mechanical damage through crushing and stresses associated with cellular dehydration. The discovery of the destructive forces of low temperatures has been put to use in cryosurgery. The concept of cryopreservation was developed by Dr. James Lovelock, whose work showed that red blood cells were damaged during this freezing, although he felt that this was largely because of osmotic stress. Gradually, work by others has resulted in large numbers of cells and tissues being preserved. The cost of cryopreservation in terms of the energy used to freeze the products and then store them is significant, with the result that it tends to be a process for only a limited number of types of biological materials. Cryopreservation is used for large numbers of blood products, especially special cells needed for transfusion, or stem cells. Similarly, tissue samples such as tumors and histological cross sections have been preserved. There has also been increased cryopreservation of semen, which can be used almost indefinitely after cryopreservation; human eggs (ococytes); and human embryos that contain two, four, or eight cells when they are frozen. Studies have shown that children born from such circumstances have no increased risk of birth defects. In recent years there has even been an effort, known as cryonics, to preserve humans cryogenically. A number of people have arranged to have their head or brain or sometimes their whole body preserved at their death in the hope that future medical science and technology might advance sufficiently for people to be reborn. A number of societies promote research in the area of cryopreservation. The main one is the Society of Cryobiology, which was founded in 1964 as the International Scientific Society for Low-temperature Biology and Medicine and which publishes the journal Cryobiology. In 1964 a Society of Low Temperature Biology was also founded in Britain. SEE ALSO: Cryosurgery. BIBLIOGRAPHY. John G. Day and Mark R. McLellan, eds.,
Cryopreservation and Freeze-Drying Protocols (Humana
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Press, 1995); P. Mazur, “Cryobiology: The Freezing of Biological Systems,” Science (v.168/934, 1970); David E. Pegg and Armand M. Karow, Jr, eds., The Biophysics of Organ Cryopreservation (Plenum, 1987). Justin Corfield Geelong Grammar School, Australia
Cryosurgery Cryosurgery is a therapeutic technique that involves the localized application of extreme cold to destroy abnormal or diseased tissue. Its name derives from the Greek word cryo, meaning “icy cold.” The main diseases and disorders that are treated by cryosurgery are often connected with skin. Cryosurgery can be used to treat warts, moles, skin tags, solar keratoses, and small skin cancers. In recent years, cryosurgery has also been used for treating some internal disorders, including cancers such as liver cancer, prostate cancer, and some cervical cancers, as well as for the control of gynecologic and urologic tumors, the elimination of hemorrhoids, and other conditions that involve diseased tissues. Although it has been found to be effective in some circumstances, it can only be used against localized diseases; that is, when the cancer has not spread. From the 1950s, developments were made in cryopreservation, which was used to store specific cells and tissues at very low temperatures. Soon, it was realized that particular cells and tissues could also be destroyed or permanently damaged owing to the method of freezing or the destructive forces on cells of the freezing temperature. Although this was originally concerned with tissue or cells away from the human body, it was only a matter of time when methods were developed to treat people with cryosurgery. It has also been found that freezing can destroy cells and tissue by triggering an immune response, which can lead to the release of intercellular proteins that can attract natural antibodies, which in turn can be used to destroy diseased cells. These techniques were developed and improved on in 1961 by the U.S. neurosurgeon Irving Cooper, who used liquid nitrogen to destroy brain tumors in the first efficient cryosurgical system applied to internal tissues.
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At its most basic, cryosurgery involves damaging blood vessels that supply diseased tissue by freezing them. This then allows parts of the body to be treated. The main technique involves the use of liquid nitrogen, which can be sprayed in very small amounts onto the diseased tissue using a tube called a cryoprobe or simply dabbed on with a cotton swab. For less severe problems, some doctors have used carbon dioxide rather than nitrogen. As cryosurgery on the skin is minimally invasive, involves minimal pain and/ or scarring, and is cheap, it is being used more and more; however, there has been new research into the possibility of damage to nerve tissue. SEE ALSO: Cryopreservation. BIBLIOGRAPHY. Richard W. Dehn and David P. Asprey,
eds., Clinical Procedures for Physician Assistants (Saunders, 2002); Nikoli N. Korpin, ed., Basics of Cryosurgery (Springer-Verlag, 2001); Gary P. Lask and Ronald L. Moy, eds., Principles and Techniques of Cutaneous Surgery (McGraw-Hill, 1996); Hans von Leden and William G. Cahan, Cryogenics in Surgery (Medical Examination Publishing, 1971); Setrag A. Zacarian, Cryosurgery for Skin Cancer and Cutaneous Disorders (Mosby, 1985). Justin Corfield Geelong Grammar School, Australia
Cuba Cuba is an island nation located in the Caribbean Sea, about 90 miles off the coast of the United States. It was a Spanish possession for 388 years, winning independence in 1902 after a brief period of occupation by the United States in the aftermath of the 1898 Spanish–American War. Fidel Castro took power in 1959 and declared Cuba a Communist state, leading to a long-term embargo by the U.S. government, which is still in effect. The collapse of the Soviet Union in the 1990s ended subsidies and nearly destroyed the Cuban economy. Standards of living dropped dramatically in the immediate postSoviet era, but are once again on the rise as Cuba normalizes relations with Latin America and makes inroads with the European Union.
Cuba is the most populous nation in the Caribbean, with an estimated population of 11.4 million people and an annual growth rate of 0.31 percent. The birth rate is 11.89 per 1,000 people, the death rate is 7.22 per 1,000 people, and the migration rate is negative, with minus 1.57 migrants per 1,000 people. Seventy-six percent of the population live in urban areas, and the overall population density is 102 people per square kilometer. As a Socialist country, most of the economy is state controlled, with 78 percent of the workforce employed by the state in its industries. Cuba’s chief exports are sugar, nickel, tobacco, citrus, and coffee; a large oil field was discovered off the coast in 2005 but has not yet been developed. Per capita income is estimated at $1,170. Despite economic downturns in the last decade, the average Cuban has a long and fairly healthy life, on par with much richer nations. At birth, life expectancy for Cubans is currently 75.11 years for males and 79.85 years for females, with healthy life expectancy at 67 years for men and 69.5 years for women. Infant mortality is low at 6.22 deaths per 1,000. Seven of each 1,000 children die before the age of 5. Maternal mortality is also low, with 33 fatalities per 100,000 live births. All Cuban women have access to prenatal care, and 100 percent of births are monitored by a trained attendant. About 70 percent of women use birth control. The fertility rate is 1.66 children per woman. Heart disease is the leading cause of death, followed by cancer, pneumonia, and accidents or violence. Diabetes has been on the rise, with an estimated 480,000 cases by 2000. In recent years, the country has embarked on a far-ranging program of education and early detection that it hopes will bring the problems under control, and diabetic care centers have been set up in each province. Major infectious diseases are rare in Cuba. There is an active malaria and dengue fever eradication program in place, and animals are vaccinated for rabies. The National Immunization Program vaccinates children against 13 separate diseases. Prevalence of HIV/AIDS is estimated to be low, at 0.1 percent. About 3,300 Cubans were said to be living with the disease in 2003. Under the dictates of Socialism, every Cuban has the right to free healthcare, and 99 percent of citizens have access to it. The World Health Organiza-
Cyprus
tion estimates the country to have approximately 67,000 physicians and 84,000 nurses. There is a wellintegrated network of hospitals and clinics throughout the country. Between 1996 and 2000, hospitals reduced the number of beds by 10,000 as more and more care was taken over by home healthcare workers and outpatient clinics. SEE ALSO: Healthcare, South America. BIBLIOGRAPHY. Central Intelligence Agency, “Cuba,”
World Factbook, www.cia.gov (cited January 2007); Peter Stalker, ed., A–Z Countries of the World (Oxford Reference Online, 2006); International Atomic Energy Agency, “Cuba’s Nutritional Mission,” www.iaea.org (cited January 2007); Pan American Health Organization, Pan American Health Organization 2005 Report, www.paho.org (cited January 2007); United Nations Children’s Fund (UNICEF), “Cuba—Statistics,” www.unicef.org (cited January 2007); World Health Organization, “Countries—Cuba,” www .who.int (cited January 2007). Heather K. Michon Independent Scholar
Cyprus The Middle Eastern island of Cyprus has had a rocky political past filled with ethnic tension, and missing health data make it difficult to draw an accurate portrait of the health and well-being of Cyprus as a whole. While Greek Cypriots control approximately two-thirds of the island, the remaining area is in the hands of Turkish Cypriots, who are concentrated in the so-called Turkish Republic of Northern Cyprus, which is recognized only by Turkey. The standard of living is much higher among Greek Cypriots, where the per capita income is $21,600, establishing Cyprus as the 49th-richest country in the world. However, per capita income plummets to $7,135 in the north, which depends heavily on aid from Turkey. Although the bulk of workers are employed in services throughout Cyprus, 14.5 percent of Turkish Cypriots are employed in agriculture as opposed to 7.4 in Greek Cyprus. Unemployment is also higher in the north (5.6 percent) than in the rest of Cyprus (4.0 percent).
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While Cyprus has no official poverty line, the government is committed to improving general health through the provision of a safety net that includes pensions, public assistance, and child benefit subsidies. Taken as a whole, the United Nations Development Programme Human Development Reports rank Cyprus 29th out of 177 countries on overall quality-of-life issues. Cyprus has no national health plan, but plans for instituting such a program are under way. The government currently provides public health services at a small fee and encourages the development of a wide range of services in the public and private sectors. The government meets the needs of rural residents through mobile health units and district physicians that offer specialized healthcare through weekly visits. Government spending on healthcare has been on the rise, and the Cypriot government expends 6.4 percent of the Gross Domestic Product (GDP) on healthcare, an increase of 1.02 percent since 1995. This funding allows $1,143 (international dollars) per capita for health costs. Less than half (49.1 percent) of total health expenditures are derived from government funding. Of that amount, 10.7 percent is earmarked for social security. The private sector contributes 50.9 percent of healthcare expenses, and 96 percent of those expenses are out of pocket. There are 2.34 physicians, 3.76 nurses, 0.82 dentists, and 0.18 pharmacists per 1,000 population in Cyprus. Among the total population of 784,301, life expectancy is 77.82 years, with females living five years longer than males on the average. Cypriots are generally literate, although there is some disparity between males (98.9 percent) and females (96.3). Approximately 98 percent of the relevant population attend primary and secondary school. Technically, all Cypriots have access to safe drinking water and improved sanitation. However, periodic droughts such as the 10-year drought that ended in 2001 have created a major shortage of fresh water in Turkish Cyprus. As a result, the government has increased the number of desalination plants. Each Cypriot woman gives birth to an average of 1.82 children. Maternal mortality currently stands at 47 deaths per 100,000 live births. Between 1990 and 2004, Cyprus was successful at cutting infant mortality by half, from 10 to five deaths per 1,000 live births. Under-5 mortality declined even further, dropping
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from 12 to five deaths per 1,000 live births between 1990 and 2004. Receiving necessary immunizations is an important element in maintaining childhood health. Some 98 percent of Cypriot infants are vaccinated against diphtheria, pertussis, and tetanus (DPT1) and polio, and 86 percent are vaccinated against measles. Cyprus has not been heavily affected by the HIV/ AIDS epidemic (it has a 1.82 adult prevalence rate), and less than 1,000 Cypriots have this disease. In order to keep HIV/AIDS under control, the National AIDS Program educates the public about how to prevent infection, and all pregnant women are tested for the disease to avoid mother-to-child transmission. Viral meningitis surfaced in Cyprus in summer 1996.
Cystic fibrosis occurs in one in 3,000 Caucasians, but does strike other groups; for example, it also afflicts one in 9,500 Hispanics.
SEE ALSO: Healthcare, Europe. BIBLIOGRAPHY. Michael E. Bonine, ed., Population, Pov-
erty, and Politics in Middle East Cities (University Press of Florida, 1997); Central Intelligence Agency, “Cyprus,” World Factbook, www.cia.gov (cited January 2007); Commission on the Status of Women, “Cyprus,” www.un.org/ womenwatch (cited January 2007); Social Watch, “Cyprus,” www.socialwatch.org (cited January 2007); World Bank, Cyprus: A Long-Term Development Perspective (World Bank, 1987); World Bank, Changing the Future: Choosing Prosperity for the Middle East and North Africa (World Bank, 1995); World Bank, “Cyprus Data Profile,” devdata. worldbank.org (cited January 2007); World Health Organization, “Cyprus,” www.who.int (cited January 2007). Elizabeth R. Purdy, Ph.D. Independent Scholar
Cystic Fibrosis First identified in 1938, cystic fibrosis (CF) is the most common inherited life-ending disease found in Caucasians, with an estimated frequency of one in approximately 3,000 live births. Since its initial discovery, scientists have learned that the genetic defect is transmitted as an autosomal recessive trait and that the CF defect impacts a single gene on chromosome 7, named the cystic fibrosis transmembrane regulator (CFTR). Once a uniform death sentence during child-
hood, because of enhancements in the care of patients with CF, the diagnosis now holds greater promise for a productive and longer life, particularly when care is received through an advanced, evidence-based medicine CF specialty care center. CF patients born in the 1990s are predicted to survive a median of greater than 40 years; this compares favorably to the early mid-20th century, when diagnosis during childhood was once predictive of death within six months. The hallmark of CF is impacted mucus and the list of commonly affected organs includes those in the respiratory tract (nose, sinuses, and lungs); digestive system (intestines, biliary system, and pancreas); and reproductive system. Although most commonly seen in descendants of European ancestors, CF has been reported in African Americans, as well as in natives of Middle Eastern countries, India, and Pakistan. The frequency of this genetic defect in nonwhites is 1:9,500 Hispanics; 1:11,200 Native Americans; 1:15,000 African Americans; and 1:31,000 Asian Americans. Because of the inherited genetic defect in the CFTR, CF patients’ epithelial cells cannot pump adequate water into their mucus secreting cells, leading to development of secretions that are much thicker and stickier than normal; these thick, tenacious secretions effectively act to block mucus glands throughout the body. The obstruction of mucus glands and small airways in the lungs leads to further retention of mucus and associated chronic
infections. Such chronic infections in the lungs, along with related complications, are ultimately the cause of death in 90 percent of CF patients. Because of chronic infections and the need for repeated administration of antibiotics, bacteria in CF patients are typically highly resistant to commonly administered antibiotics. This antibiotic resistance makes it much more difficult to find the right combination of antibiotics to treat infections. As the repeated infections become increasingly difficult to clear, CF lung disease progresses to the development of bronchiectasis (a condition where the airways lose their supportive structure, become extraordinarily dilated, and retain even more mucus). Development of bronchiectasis makes the CF patient more prone to lung collapse (pneumothorax), another respiratory complication of CF. Symptoms Respiratory symptoms include cough, shortness of breath, wheezing, and chest pain. When an acute infection occurs, patients may develop fever, muscular pains, fatigue, lack of appetite, and weight loss. Patients may also develop infections and symptoms of sinusitis, bronchitis, and nasal polyps. Gastrointestinal symptoms may be present at the time of birth. A condition known as meconium ileus (an acute obstruction of the intestines due to thickened secretions) may be present at birth and often requires emergent surgery for correction. CF patients who experience involvement of the pancreas may develop diabetes (usually requiring insulin) and, in addition, experience difficulty digesting proteins and fats. As a result of the protein and fat malabsorption, CF patients commonly report very foul smelling bowel movements that are often described as greasy and difficult to flush. Vitamin deficiencies are a frequent accompaniment to the intestinal malabsorption seen in CF, and without correction, they may lead to malnutrition, nerve damage, bleeding problems, and thinning of the bones. Other symptoms and conditions that can develop related to the above processes include abdominal pain, constipation, appendicitis, lack of appetite, nausea, vomiting, lack of bowel movements, and gall stones. Men with CF commonly produce semen without any sperm and, as a result, are not able to naturally father children. This is typically because their vas
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deferens (the small tubes that connect the testes with the urethra) are congenitally absent. Despite this abnormality, sexual desire and function is typically not altered in men with CF. Women with CF who are able to maintain a normal nutritional status have reduced fertility rates, but not exceedingly so. Therefore, birth control measures must be discussed with women who have CF and who are sexually active. In addition, any individual with CF should be referred for genetic counseling prior to becoming pregnant. Diagnosis and follow-up Males and females are affected equally with CF. It is estimated that 70 percent of patients with CF are diagnosed by the age of 1, and 90 percent by the age of 8. Rarely, patients with CF have a delayed diagnosis into adulthood. Evaluation of the chloride content of sweat is still the most commonly used screening tool for patients suspected of having CF. A positive test is indicated when the sweat chloride measures more than 60 mmol/L in children and more than 80 mmol/L in individuals over the age of 18. A positive test should be repeated and tests should only be performed by a laboratory accredited by the CF Foundation. Genetic testing should be performed when the diagnosis of CF is suspected and the sweat chloride is normal. Genetic testing should also be considered when prenatal diagnosis is desired or needed for CF. More recently, newborn screening for a substance called immunoreactive trypsin has begun. Newborn blood can be tested for this substance, but frequent false positives occur, necessitating further, more sophisticated testing in the event of a positive result. Genetic testing of CF patients has revealed that there are over 1,000 known different variant CF-causing alleles. It has been estimated that upward of 70 percent of CF chromosomes in the United States possess delta F508 alleles. A variety of other diagnostic tests are frequently employed in CF patients. These include chest X-rays, sputum cultures (to identify bacterial causes of respiratory infections), computed tomography (CT) of the chest, sinus evaluation, testicular ultrasounds, semen analysis, and pancreatic testing. During the 1990s, the CF Foundation developed guidelines in an attempt to standardize care for
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patients with CF. The CF foundation has recommended that the following surveillance tests be frequently performed on patients with known CF, with an emphasis on catching disease progression early, thus enabling aggressive management: • Outpatient visits to healthcare provider (four or more times per year) • Pulmonary function testing (two or more times per year) • Sputum cultures (at least once a year) • Creatinine (kidney function) testing (every year) • Blood sugar (glucose) testing (every year after age 14) • Liver tests (every year) Lung function testing is done to follow progressive decline in function. Exacerbations of CF may be detected early when pulmonary function declines, allowing a head start on the institution of therapy for the exacerbation. Patients with moderate to severe CF as well as those experiencing exacerbations (such as bronchitis or pneumonia) should be monitored for low blood oxygen levels, and when discovered, oxygen supplementation must be provided promptly. Treatment Inhaled breathing treatments with drugs known as beta agonists (e.g., albuterol) are typically provided to CF patients despite the lack of evidence supporting their broad use in patients who have not yet developed obstructive lung function parameters. Administration of hypertonic (concentrated) saline mist breathing treatments has recently shown a statistically significant ability to help CF patients rid their lungs of mucus, which helps to reduce exacerbation rates and improves lung function. The use of inhaled antibiotics, particularly tobramycin, has been shown to reduce infections and numbers of exacerbations, and to reduce the numbers of pseudomonas bacteria in sputum samples from CF patients. The typical dose administered to adult patients with CF is 300 milligrams inhaled two times per day in four-week intervals. More recently, use of one of the “newer” macrolides in CF patients has become more common. Azithromycin was investigated in a research study whereby research subjects received the drug three times per week if over the age of 6. This treatment
has been shown to reduce colonization of the airways with pseudomonas, improve pulmonary function, reduce exacerbations and hospitalizations, and improve nutritional status of CF patients. Dornase alfa (recombinant human DNase, marketed as Pulmozyme®) has been shown in at least one multicenter study to lead to modest improvement in lung function as well as reduced numbers of exacerbations. Techniques aimed at helping the patient cough up his or her respiratory secretions are used in most CF patients with documented lung disease. Examples of these techniques include clapping on or vibration of the chest. In addition, CF patients should be counseled to actively exercise to enhance cardiovascular fitness and improve quality of life. In general, antibiotics are reserved for documented exacerbations; however, antibiotics are probably the single most important reason that CF patients are living longer and more productive lives. Along these lines, many CF centers have adopted a protocol that provides for preventive use of antibiotics administered whenever sputum cultures reveal potentially resistant and destructive bacteria (e.g., Pseudomonas), even in the absence of chest X-ray abnormalities or patient symptoms. This strategy has been demonstrated to prolong the time before CF patients begin to have chronic infections with such bacteria. Acute exacerbations of CF involving respiratory infections are routinely treated with intravenous antibiotics, with the choice of antibiotic based upon the most recently isolated sputum bacteria. Administration of long-term inhaled antibiotics (e.g., tobramycin) has been shown to improve lung function and reduce CF exacerbations. Consistent use of antiinflammatory therapies, such as ibuprofen, has been shown to reduce the rate of lung function decline in CF patients. In addition, therapy with corticosteroids has led to delays in the progression of CF; with oral corticosteroid therapy, the risks of complications of therapy, including cataract development, diabetes, and growth reduction are higher than with inhaled corticoteroids. At the present time, considering the risks–benefit ratio of using systemic corticosteroids, most practitioners are electing not to prescribe oral corticosteroids to CF patients for long-term use. Attention to good nutrition is paramount in CF patients; it is recommended that 35 to 40 percent of
Cytogenetics
calories be delivered daily as fats. If pancreatic insufficiency is present, the patient should take pancreatic enzyme supplements with each meal and snack in doses adequate to maintain weight and prevent fatty, greasy stools. Fat soluble vitamins should be administered daily, including vitamins A, D, E, and K. Men with CF who desire to have children should be evaluated for candidacy for techniques to harvest spermatozoa directly from the testes. These sperm samples can be used for fertilization via artificial insemination. Women with CF who desire to have children are frequently able to conceive without much difficulty. Obviously, if a woman with CF anticipates becoming pregnant, it would be in her best interest to work with a physician to develop a plan to optimize her physical state and pulmonary function; doing so would allow for the best possible chance for a successful pregnancy. Regular exercise and physical conditioning is extremely important in CF patients. Exercise has been shown to improve physical fitness, possibly increase secretion clearance, and improve quality of life. The most common exercises recommended include aerobic forms of exercise such as swimming, walking, jogging, and cycling. Additional Therapies Lung transplantation has been performed in some individuals with CF who have developed end-stage pulmonary involvement. The long-term survival rates in CF patients undergoing lung transplantation are estimated as 60 percent at five years post-transplantation. Generally accepted indications for lung transplantation in patients with CF include FEV1 (lung function test) less than 30 percent of predicted value; low blood oxygen levels or high blood carbon dioxide levels; increased hospitalization frequency; frequently coughing up blood; or extreme malnutrition. Difficulties with lung transplantation in CF patients are similar to those encountered with patients requiring other organ transplants; these include paucity of donor organs, deterioration of the CF patient’s condition prior to the time that a donor is located, and so forth. Survival of CF patients posttransplant is estimated to be 80 percent at one year, and less than 50 percent at four years. Several ongoing research trials are underway that should assist practitioners and CF patients with new therapies to
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extend their life span. Examples of new therapies include gene therapy to correct the basic genetic defect. A good resource for patients with CF and their families is the Cystic Fibrosis Foundation. SEE ALSO: Bronchitis; Genetic Disorders; Genetic Test-
ing/Counseling; Lung Transplantation; Pneumonia.
BIBLIOGRAPHY. A. Boehler, “Update on Cystic Fibrosis:
Selected Aspects Related to Lung Transplantation,” Swiss Medical Weekly (v.133, 2003); Cystic Fibrosis Foundation, www.cff.org (cited May 2007); P.B. Davis, “Cystic Fibrosis since 1938,” American Journal of Respiratory and Critical Care Medicine (v.173, 2006); A.J. Gershman, et al., “Cystic Fibrosis in Adults: An Overview for the Internist,” Cleveland Clinic Journal of Medicine (v.73/12, 2006); N.L. Turcios, “Cystic Fibrosis—An Overview,” Journal of Clinical Gastroenterology (v.39/4, 2005). Sandra K. Willsie, D.O. Kansas City University of Medicine and Biosciences
Cytogenetics Cytogenetics deals with chromosomal structures and their inheritance as applied to clinical medical genetics. Chromosomes are microscopic structures found in cells and malformations associated with them lead to numerous genetic diseases. Over the years, chromosomal analysis has improved in precision and resolution, and has led to improved diagnosis of various genetic diseases in all areas of medicine. Genetic diseases begin with a mutation in chromosomal structure. The hundreds of types of genetic diseases include congenital abnormalities, reproductive wastage, and retarded mental growth. Statistics show that approximately 1 percent of all live births have congenital abnormalities (2 percent to women over 35) and they are present in 50 percent of all spontaneous abortions. Some common genetic disorders are Down syndrome, Turner’s syndrome, cystic fibrosis, and Huntington’s disease. The study of chromosomes begins with the extraction of intact chromosomes from live body cells. The most common cells used for chromosomal studies
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are white blood cells (T lymphocytes) because they grow rapidly in cell cultures. These cells are arrested in metaphase, and treated with hypotonic solutions to release their chromosomes. The only disadvantage is that these cell cultures live only three to four days. Chromosomes may also be extracted from skin fibroblasts, bone marrow cells, lymphoblastoid cells, and fetal cells (from amniotic fluid and chorionic villus biopsy). After cells are extracted, they have to be viewed so that chromosomes can be identified for abnormalities. The 48 pairs of chromosomes can be identified by using various staining techniques such as Q banding, R banding, C banding, G banding, and fluorescence in situ hybridization (FISH). G banding is the most used chromosomal staining method. Chromosomes are first treated with trypsin and then with Giemsa stain. All chromosomes can be individually identified using this technique. With Q banding, chromosomes are stained with quinacrine mustard or related compound, and examined by florescence microscopy, which is useful for detecting heteromorphisms—occasional chromosomal structural and staining variants. Before chemical staining using the R banding menthod, chromosomes are treated with heat, resulting in patterns that are easier to analyze. In C banding, regions of chromosomes containing heterochromatin are stained. FISH is used to examine the presence or absence of a particular DNA sequence, and the number or organization of a chromosome or chromosomal region. With FISH, technicians use DNA probes to detect individual DNA sequences and copies of a particular chromosome. These probes can also be developed to scale entire lengths, and “paint” target chromosomes in metaphase and anaphase. Chromosomal Abnormalities There are two main types of chromosomal abnormalities: aneuploidy and translocations. Aneuploidy is an abnormal chromosomal number due to extra or missing chromosomes, for example, Down syndrome. This is the most common type of chromosomal abnormality, and persists in 3 to 4 percent of all clinically recognized pregnancies. Aneuploidy is further divided into trisomy or monosomy. Trisomy is usually caused by meiotic nondisjunction. Nondisjunction is most common at meiosis I, but can occur during meiosis II, and even less frequently during mitosis.
Translocations are due to abnormal rearrangements in chromosomal material. Material may be exchanged between different chromosomes, causing disease. There are two types of translocations: balanced and unbalanced. Balanced translocations occur if the cell ended up with a normal number of chromosomes; no symptoms are presented. Unbalanced translocations occur if there is additional or missing material and abnormal phenotype may be visible. They are more commonly found in couples who have had two or more spontaneous abortions. SEE ALSO: Chromosome; Genetic Disorders; Genetics;
Genetic Testing/Counseling.
BIBLIOGRAPHY. R.J. McKinlay Gardner and Grant R.
Sutherland, Chromosome Abnormalities and Genetic Counseling (Oxford Monographs on Medical Genetics, No. 46) (Oxford University Press, 2003); Robert L. Nussbaum, Roderick R. McInnes, and Huntington F. Willard, Genetics in Medicine, 6th ed. (Thompson & Thompson, 2001); Albert Schinzel, Catalogue of Unbalanced Chromosome Aberrations in Man, 2nd ed. (Walter de Gruyter, 2001); Herman E. Wyandt and Vijay S. Tonk, eds., Atlas of Human Chromosome Heteromorphisms (Springer, 2004). Rahul Gladwin University of Health Sciences Antigua
Cytokine Cytokines are small secreted protein messengers that are involved in a range of physiological processes, including development and wound healing. They have a particularly pivotal role in the immune system. Similar to hormones, cytokines affect the behavior of their target cells—causing effects such as growth, proliferation, and migration. Yet, unlike hormones, cytokines are produced by a variety of cells, rather than specialized glands. The roles of different cytokines are not completely understood, and they are the subject of intense research efforts. As a result of the important role of cytokines in the immune response, these molecules may have medical applications that have only begun to be explored.
When a pathogen breaches the skin and establishes a focus of infection, the white blood cells that initially detect this infection become activated and release cytokines. These cytokines act on nearby blood vessels and attract other white blood cells to attack the infection, thus leading to an inflammatory response. The cytokines that are released in response to an infectious agent determine the course of the immune response—for instance, whether it will be a cell-mediated or antibody-mediated response. Because different kinds of immune responses are required to effectively combat various disease agents, a proper cytokine profile is crucial in ensuring an appropriate response to a pathogen or tumor. A cytokine can act on any cells that have a receptor for it—this can be the same cell that secretes it, nearby cells, or even distant cells throughout the body. In most cases, cytokine receptors are found on white blood cells, although some cytokine receptors are found on other cell types, such as blood cell precursors and the endothelial cells lining blood vessels. Interestingly, a single cytokine can have different effects on various cell types. Cytokine networks can be extremely complex because various cytokines can have similar effects, and each of these chemical messengers can promote or interfere with the actions of other cytokines. This cross-talk and redundancy causes it to be difficult to discern the biological roles of individual cytokines. Clinical Uses of Cytokines Current knowledge regarding cytokines has led to the realization that these molecules have promise as medical tools, and they may allow physicians to manipulate the immune response in a manner that is beneficial to the patient. For instance, cytokines that promote the growth of white blood cells are currently given to patients on chemotherapy to help the immune system rebound after the difficult treatment regimen. In addition, abnormal immune responses are the cause of allergies and autoimmune diseases, and cytokines may hold the key to treating these disorders. As yet, the clinical applications of these molecules are still largely uninvestigated. A further understanding of the role of cytokines in various disorders, such as autoimmune diseases and cancer, may lead to novel and effective therapies for these illnesses.
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SEE ALSO: Autoimmune Diseases; Hormones; Immune
System and Disorders; Immunology.
BIBLIOGRAPHY. Luke A.J. O’Neill, “Immunity’s Early-
Warning System,” Scientific American (January 2005); Nicholas P. Plotnikoff, et al., eds., Cytokines: Stress and Immunity, 2nd ed. (CRC, 2006); Daniel Remick, ed., Cytokines in Health and Disease, 2nd ed. (Informa Healthcare, 1997); Angus W. Thomson and Michael T. Lotze, eds., The Cytokine Handbook, 4th ed. (Academic Press, 2003). Kevin Shenderov New York University
Czech Republic After the so-called Velvet Revolution of 1989 released Czechoslovakia from its relationship with the Soviet bloc, the country resumed the liberalizing process that had been put down in 1968 by the Soviet Union. In a “velvet divorce” on New Year’s Day 1993, the country divided into the Czech and Slovak republics. The Czech Republic is one of the most financially stable countries in Eastern Europe, and living conditions have been further strengthened by entry into the European Union (EU) since all member states are required to meet EU guidelines. Major pension and healthcare reforms are in the planning stages. With a per capita income of $20,000, the Czech Republic is the 53rd-richest country in the world. Unemployment stands at 8.9 percent, and unemployed workers often depend on the government for assistance. Budget cuts in 2004 led to the tightening of eligibility for such assistance. There is no abject poverty, but income inequality does exist. The Czech Republic ranks 25.4 on the Gini index of inequality, with the richest 10 percent of the population claiming 22.4 percent of all resources and the poorest 10 percent sharing 4.3 percent. The United Nations Development Programme Human Development Reports rank the Czech Republic 30th in the world on general quality-of-life issues. Between 1993 and 2004, the government spent an average of 17 percent of the budget on healthcare. Currently, health spending is 7.5 percent of the Gross Domestic Product (GDP), and $1,302 (international
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dollars) per capita is allotted for health-related programs. Ninety percent of health expenditures derive from government funding; 85.4 percent of that amount is directed toward social security, which is financed by contributions from employers (19.5 percent of payroll) and employees (6.5 percent of earnings) and supplemented by the government. The elderly, the disabled, and survivors are covered under social security. The private sector accounts for only 10 percent of health spending in the Czech Republic, and 83 percent of that involves out-of-pocket expenses. There are 3.51 physicians, 9.71 nurses, 0.47 midwives, 0.66 dentists, and 0.55 pharmacists per 1,000/ population in the Czech Republic. A health crisis erupted in February 2006 when more than 100,000 members of the health profession demanded the immediate resignation of the new health minister who had promised to make the struggling health industry more financially viable. Detractors argued that the reforms were returning the health profession to a state-controlled system. Physicians and pharmacists went on strike, outraged that the minister had used his authority to set limits for insurance coverage that slashed rates for their services. Some Czechs maintained that services were being denied and overall health threatened by the minister’s actions. Another potential crisis loomed over whether or not healthcare workers would leave the country en masse to seek more lucrative employment in other EU states. The government was particularly concerned about the ongoing loss of Czech physicians who earn only a fourth of the salaries paid to doctors in other EU countries. The population of 10,235,455 Czechs enjoys a life expectancy of 76.22 years, with women outliving men an average of six years. Literacy is high at 99 percent, and primary and secondary schooling is available to all students. Safe drinking water and improved sanitation are also universally available. Birth control is used by 72 percent of Czech women, and the Czech Republic has the sixth-lowest fertility rate in the world (1.21 children per female). All births are attended by trained personnel, and 99 percent of women receive antenatal care. The adjusted maternal mortality rate is one of the lowest in the world at nine deaths per 100,000 live births. The Czech Republic has the ninth-lowest infant mortality rate in the world at 3.89 deaths per 1,000
live births. Between 1990 and 2004, the government successfully reduced infant mortality from 11 to four deaths per 1,000 live births and under-5 mortality from 13 to four deaths per 1,000 live births. Seven percent of infants are underweight at birth, and 1 percent of under-5s are moderately underweight. Two percent of the under-5 population suffers from wasting and/or stunting. Childhood immunizations are high in the Czech Republic, and 99 percent of infants are immunized against tuberculosis; 98 percent against diphtheria, pertussis, and tetanus (DPT1 and DPT3), hepatitis B, and Haemophilus influenzae type B; 97 percent against measles; and 96 percent against polio. Extensive air and water pollution in northwest Bohemia and northern Moravia has created a major health threat, but environmental conditions are expected to improve as the government complies with EU regulations. HIV/AIDS is well under control and has a 0.1 percent adult prevalence rate. While 2,500 people are living with the disease, it has proved fatal to less than 10 people. Influenza created major health problems in 2003 and 2004. SEE ALSO: Healthcare, Europe. BIBLIOGRAPHY. Central Intelligence Agency, “Czech Re-
public,” World Factbook, www.cia.gov (cited December 2006); Commission on the Status of Women, “Czech Republic,” www.un.org/womenwatch (cited December 2006); Ihor Gawdiak, Czechoslovakia: A Country Study (Federal Research Division, Library of Congress, 1989); Katka Krosnar, “Czech Health Workers Call for Minister to Be Sacked,” Lancet (April 1, 2006); Martin A. Levin and Martin Shapiro, eds., Transatlantic Policymaking in an Age of Austerity: Diversity and Drift (Georgetown University Press, 2004); Martina Mareckova, “Exodus of Czech Doctors Leaves Gaps in Health Care,” Lancet (May 1, 2004); Social Security Administration, “Czech Republic,” www. ssa.gov (cited December 2006); United Nations Children’s Fund (UNICEF), “Czech Republic,” www.unicef.org (cited December 2006); World Bank, “Czech Republic Data Profile,” devdata.worldbank.org (cited December 2006); World Health Organization, “Czech Republic,” www.who. int (cited December 2006). Elizabeth R. Purdy, Ph.D. Independent Scholar
D Daily Reference Values (DRVs) The daily reference value (DRV) is a number of statistics assigned by the U.S. Department of Agriculture for the optimum diet, both in overall amount and in type. The DRV for adults and children over the age of 4, based on a diet of 2,000 calories a day suggests that about 30 percent of all calories can be fat (about 65 g), of which just a bit less than a third of it (20 g) should be saturated fat. Some 60 percent of the diet should consist of carbohydrates (300 g), with 10 percent consisting of protein (50 g). The diet should also contain 300 mg of cholesterol, 25 g of fiber, some 2,400 mg of sodium, and 3,500 mg of potassium. DRVs have been important in food labeling, although many people only study them from the information on cereal packets, even though it appears on many other items of food. In Australia and New Zealand, DRVs are known as recommended dietary intake, although the U.S. Department of Agriculture does state categorically that DRVs are not the recommended amounts of nutrients that people should eat in one day but more the balance of the diet they should aim to have over a period of time. Most of the nutritional information figures printed on food labels include the average size of servings,
the number of servings in a particular package, and the nutritional information in regard to the quantity per serving, the percentage of the suggested daily intake per serving, and the quantity per 100 g, which may be larger or smaller than the serving size. For some foods that are generally eaten with something else, such as most people eating cereal with milk, figures are also given for the overall level of nutrients when the two are combined. The use of DRVs allow people to assess whether their diet exceeds the amount of fat, saturated fat, cholesterol, or carbohydrates that they should be eating, and serve as an important reference point for people dealing with dietary problems. In particular, most people play close attention to the fat level of products such as cookies, peanut butter, and potato chips, which vary considerably from brand to brand. SEE ALSO: Dieting. Bibliography. Paula Kurtzwell, “Daily Values Encourage
Healthy Diet,” http://www.fda.gov/FDAC/special/foodlabel/dvs.html (cited August 2007). Justin Corfield Geelong Grammar School, Australia
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Darwin, Charles (1809–82) The naturalist and evolutionary biologist Charles Darwin was born in Shrewsbury, England, on February 12, 1809. A polymath, Darwin was also educated in theology, chemistry, medicine, and geology. Extensive field research, comparative study and reflection on the writings of other natural scientists led him to infer that natural selection explained how species differentiated from one another, including species whose only trace was found in ancient fossil records. During 1831–36, Darwin sailed along the coast of the Atlantic and Pacific coasts of South America in the British naval vessel HMS Beagle. Periodically, Darwin went ashore for weeks and months at a time. During those five years, his analytic methods consisted almost entirely of making extensive observations, recording his findings systematically, and making comparative and inductive generalizations. During that period, Darwin spent a crucial three months doing field research on the isolated Galapagos Islands where species varied astonishingly from one island to another. Darwin first thought of natural selection as early as 1838. More than 20 years later, the first edition of Darwin’s The Origin of Species was published in 1859. This underwent six editions. As Darwin concisely summarized his theory of evolution through natural selection in the final edition, “Species have been modified through a long course of descent. This has been effected chiefly through the natural selection of numerous successive, slight, favourable variations.” Darwin acknowledged intellectual debts to 20 others who had written about evolution, including Erasmus Darwin, Jean-Baptiste Lamarck, Charles Lyell, and Alfred Russel Wallace. Darwin died in Downe, England, in 1882. As a result of a petition in Parliament, he was buried in Westminster Abbey. Subsequent discoveries have validated and elaborated many of Darwin’s claims. Others used Darwin’s work to support political arguments that he might have rejected. For example, Social Darwinism crudely asserted racist claims that the predominance of the strongest nations over weaker societies justified imperialists’ right to rule over vast colonies in Africa, the Americas, Asia, and the Pacific.
Despite corroborating evidence, Darwin’s theory of gradual, incremental change over millions of years has been contentious. Controversially, humans are part of nature—not separate from it. In reaction, opponents of Darwin on state and local U.S. public school boards have attempted to relegate Darwin’s theory of evolution in the curriculum to a theory competing with theological explanations like creationism or intelligent design. see also: Acquired Mutation; DNA; Watson, James. BIBLIOGRAPHY. Charles Darwin, The Voyage of the Beagle
(First published, 1839; P. F. Collier & Son, 1909); Charles Darwin, On the Origin of Species, 6th ed., The Harvard Classics, vol. 29 (First published, 1872; Franklin Center, Franklin Library, 1975); Frank. J. Sulloway, “Why Darwin Rejected Intelligent Design,” in Intelligent Thought: Science versus the Intelligent Design Movement, ed. John Brockman (Vintage Books, 2005). Vincent Kelly Pollard University of Hawaii at Manoa
Date Rape Date rape is a term used largely in industrialized countries to describe what a victim experiences when he or she is forced or coerced into unwanted sexual activity by a friend, romantic suitor, or peer through violence, verbal pressure, misuse of authority, or threat of violence. While some prefer the more inclusive term acquaintance rape, which does not imply any sort of romantic relationship between the rapist and the victim, both terms acknowledge the fact that the majority of women (and men) who are raped know their attackers, and that the victim did not consent to sexual activity. Both terms were originally introduced into public health parlance in the 1980s in an attempt to dispel the myth that the majority of rapes occurred due to random attacks by strangers, and to give voice to sexual experiences many women believed had been nonconsensual, but were not criminal in nature as they occurred in the context of a romantic relationship. Advocates for the rights of rape victims emphasized the concept of date rape to promote awareness that all sexual activity requires explicit consent from both parties; a new, prior,
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A recent concern is the use of “date rape drugs” such as rohypnol, which can be slipped into alcoholic or other drinks.
or ongoing dating or intimate relationship does not necessarily imply that either party has a ‘“right” to sexual relations. This new awareness of date rape has led to legal changes in the United States that make it easier for victims to prosecute attackers, although much discussion remains about the legal standards of consent. While it is hard to determine the rates of date rape in the United States, even less is known regarding rates of date rape worldwide, especially in cultures where dating and premarital romantic and sexual relationships either do not occur, or in very different contexts. The related concept of marital rape has recently been utilized in developing countries to describe unwanted sexual contact by a spouse, particularly in regards to increasing women’s sexual rights as a means of preventing HIV infection. A recent concern, particularly among young people, is the use of “date rape drugs” such as rohypnol, GHB, and ketamine, which can be slipped into alcoholic or other drinks when a victim is not looking. These drugs are odorless, colorless, and produce paralysis, blackouts, and memory loss, making victims vulnerable to attackers. Intoxication due to alcohol or other drugs is often associated with date rape. SEE also: Club Drugs; Sexually Transmitted Diseases. BIBLIOGRAPHY. William A. Bridges, and James Hale, eds.,
Date Rape (Thomson Gale, 2004).
Annie Dude University of Chicago
Leonardo da Vinci was one of history’s great polymaths, a supremely talented artist, sculptor, inventor, architect, and engineer. He was also the most gifted anatomist of the Renaissance era. Born in April 1452 in the town of Anchiano and raised in Vinci, 50 miles west of Florence, Leonardo di ser Piero da Vinci was an illegitimate child, and thus blocked from most professions of the time. Noting his son’s skill for drawing, around 1468 Leonardo’s father sent him to apprentice with famed artist Andrea del Verrocchio in Florence. In Verrocchio’s workshop, da Vinci would study alongside a generation of famous artists, including Sandro Botticelli, Cosimo Rosselli, Piero Perugino, and Domenico Ghirlandaio. Anatomy was part of the training for any budding young apprentice painter, and one that da Vinci approached with great interest. Most painters would have confined themselves to external observation, but da Vinci was driven by a desire to understand the inner workings of man, and eventually, the skills he honed dissecting frogs, cows, birds, and bears gave way to the desire to dissect a human body. Exactly when he began this work is not clear, but it was probably in the early 1500s. In 1507, while living in or near a hospital in Florence, he gave this account: “An old man a few hours before his death told me that he had passed a hundred years, and that he did not feel any bodily deficiency other than weakness. And thus while sitting on a bed in the hospital of Santa Maria Nuova in Florence, without any movement or sign of distress he passed away from his life. And I made an anatomy of him in order to see the cause of so sweet a death.” Inside the old man’s heart, da Vinci observed thick deposits within the aorta and surrounding veins—the first observation of atherosclerosis, or hardening of the arteries—centuries before the medical profession had a name for it. Estimates of how many autopsies da Vinci performed vary, with most scholars putting the count at 30; the majority of them were conducted between 1510 and 1513. It was challenging work for the artist, and conditions were far from pleasant. There was always the chance of contracting disease or infection,
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and without benefit of embalming, bodies decomposed rapidly. However, he persevered in the work and rendered his observations in almost 1,000 exquisitely detailed drawings. One of his great innovations was the cross-sectional view of anatomy. “ … [To] give knowledge of the true form of any member of man . . . I shall observe this rule, making of each member four representations from the four sides. And in the case of the bones, I shall make five, cutting them through the middle and showing the cavity of each of them … ,” he once wrote of his technique. One of his more famous sketches showed a fetus in the crosssection of a womb. He was the first to accurately show the S-curve of the human spine and the first to depict an appendix. Human dissection was rare outside medical schools, and religious and social taboos abounded. The artist was eventually accused of necromancy, or communicating with the spirits of the dead. When he moved to Rome in 1513, he had to worry about running afoul of the Church; Pope Leo X did eventually prohibit him from conducting more autopsies. Da Vinci had always intended to publish his anatomical work, perhaps as an encyclopedia or atlas of the body, but like so many projects he had planned, he never had the time to see it through to fruition. He died in May 1519. Over 150 years later, in 1680, many of his drawings were finally put in book form, not as a work on anatomy, but in a work entitled Treatise on Painting. See Also: Heart Diseases (General); Italy. Bibliography. Martin Kemp, Leonardo da Vinci: The
Marvellous Works of Nature and Man (Oxford University Press, 2007); Charles Nicholl, Leonardo da Vinci: Flights of the Mind (Viking Adult, 2004). Heather K. Michon Independent Scholar
Deafness Deafness refers to the loss of a portion or all of the sense of hearing. This is the pathological definition and should not be confused with the term “Deaf ” which is
always capitalized and defines the culture of persons who cannot fully hear, do not view their deafness as a pathological or medical condition, and whose choice of communication is typically Sign Language. The term “deaf ” (with a small “d”) refers to persons who have a hearing loss, and who do not consider themselves as culturally Deaf and frequently prefer spoken or manually coded language (i.e., Signed Exact English) and if they had no hearing loss they would be a part of the hearing world. In general, there are three types of hearing loss: conductive, sensorineural, and mixed. Because of the development of the fetus and the young child, there are different subtypes or etiologies when considering pediatric and adult deafness. Conductive hearing loss is caused by any obstruction that limits external sound from traversing the external auditory canal, the tympanic membrane, the ossicles, and into the inner ear. Common acquired conductive obstacles of the external auditory canal encountered in clinical practice in adults include excessive buildup of cerumen (ear wax), external auditory canal infection with swelling and debris (otitis externa), fluid in the middle ear (both sterile and infected), and a loss of the ossicular mobility so that vibrations are not completely carried to the inner ear. Less commonly, tumors of the external auditory canal can cause conductive hearing loss. The most common cancerous tumor is squamous cell carcinoma, followed by basal cell carcinoma and melanoma. Tumors of bony origin include osteomata and exostoses and limit hearing by blocking sounds from reaching the tympanic membrane. Conductive hearing losses due to middle ear pathology include Eustachian tube dysfunction, development of a cholesteatoma; infection and fluid buildup with or without tympanic membrane perforation. Congenital malformations of the external auditory canal, tympanic membrane, and ossicles are also causes of conductive hearing loss. In the pediatric population, congenital atresia (lack of development) of the external auricle, external canal, tympanic membranes, ossicles, and or the cochlea are causes of conductive hearing loss. Also, suppurative otitis media (infected) and otitis externa; dysfunctional tympanic membranes with or without perforation; and cholesteatoma all cause conductive hearing loss. A cholesteatoma is a growth of epithelium from the external canal migrating into the middle ear and
causing a buildup of sloughed surface cells and chemicals which both block the hearing and destroy the inner ear. Malformations caused by trauma can cause any degree of conductive hearing loss depending on the obstructive sequelae. Sensorineural hearing loss is caused by a deficient functioning of the inner ear cochlea and eighth cranial nerve (Vestibulocochlear nerve). Presbycussis (hearing loss of old age) is multifactorial and probably is caused by lifelong noise exposure, medications, and familial tendencies. In one series screening over 2,000 Medicare recipients, nearly 60 percent qualified as having sensorineural hearing loss. Another cause of sensorineural hearing loss is ototoxicity from multiple drugs, representative of which are the aminoglycosides (gentamicin, etc.); cancer chemotherapeutic agents (the worst being cisplatinum, then 5-FU and nitrogen mustard and bleomycin); aspirin; and antimalarial medications (chloroquine). Degenerative and destructive causes of sensorineural hearing loss include multiple sclerosis, diabetes, cerebrovascular insufficiency, and cholesteatoma, while compressive causes include Arnold-Chiari malformations (downward traction of the base of the brain, thus stretching the acoustic nerve) and acoustic neuroma. This is a non-cancerous tumor arising from the eighth cranial nerve, which can destroy the hearing in that ear. Perilymphatic fistula (caused generally by congenital malformations or mechanical trauma or barotraumas [excessive positive or negative air pressure exposure] to the inner ear) causes the internal fluid from the cochlea to leak out, thus distorting the sound/fluid wave mechanism of the inner ear, which causes a sensorineural hearing loss. This requires surgery to repair the round or oval window of the cochlea. Congenital sensorineural hearing loss can be caused by intrauterine exposure to viral infections such as HIV, syphllis, cytomegalovirus, hepatitis, rubella, and toxoplasmosis. Inherited forms of sensorineural hearing loss follow both autosomal dominant and autosomal recessive patterns yielding all combinations of hearing/deaf parents and children. Evaluation of Deafness The evaluation of deafness in the adult begins with a complete history and physical examination. The history should be complete as to the patient’s mother’s prenatal course, including establishment of the mater-
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nal immunity to rubella and lack of exposure to other ototoxic viruses (see above). Patient-specific questions should focus on the onset, severity, associated symptoms (dysequilibrium, tinnitus, etc.), history of recurrent infections, mechanical and barotraumas, previous otologic surgery, otalgia, and otorrhea (ear pain and drainage from the external auditory canal). Besides routine blood work (a complete blood count, chemistry panel, and TSH to evaluate the thyroid function), an office-based tuning fork examination is a high-yield screening test to help differentiate between conductive and sensorineural hearing. Tuning forks of 256 and 512 Hz are used to estimate the amount of hearing loss present. If a person cannot hear the 256 Hz tuning fork and can hear the 512 Hz tuning fork, then a 10-15 dB loss is present. If the person cannot hear the 512 Hz tuning fork, then the loss is estimated at 20 to 30 dB. Air conduction should produce a louder sound than bone conduction and is tested by striking the tuning fork and holding it near the external canal opening. Bone conduction is then tested by placing the vibrating tuning fork on the mastoid process and the patient reports which of the two tones seemed the loudest, which should be the air conduction in the normal ear. This is the Rinne test. The Weber test is performed by placing the vibrating tuning fork on a midline osseous facial structure (bridge of the nose, between the upper central incisors, etc.) and asking the patient which ear perceives the louder sound. In the normal ear exam, the sound is heard equally well bilaterally. If the patient reports that the tone lateralizes to one ear, this indicates a conductive hearing loss to that ear or a sensorineural hearing loss to the contralateral ear. Direct otoscopy should be performed and pathological changes such as cerumen impaction, infections, tumors, tympanic membrane abnormalities and middle ear fluid or ossicular abnormalities can be visualized. As a part of the workup of hearing loss, pneumoscopy should be performed. The size of the otoscope speculum is chosen to create an air tight chamber of the external auditory canal and with direct visualization of the tympanic membrane (TM) a small amount of air is insufflated. A nonmobile TM indicates a middle ear effusion, tumor, or a sclerosis (scarring). A hypermobile TM is seen with disruption of the ossicles.
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Formal audiometric evaluation in a soundproof room is indicated in conditions of sudden hearing loss, sensorineural loss, and as a part of the workup for possible hearing amplification and or cochlear implant consideration. Otoacoustic emissions (OAE) testing is now required in over 30 states as a hearing screening test in the newborn nursery. The basis of the test is that when the cochlea is presented with certain sounds, the outer hair cells can respond with sound production which is then measured by a sound emitting and receiving probe placed in the external ear canal.
population about noise pollution is becoming more of an issue with the popularity of the digitalized pocket personal music systems. Environmental noises such as a lawn mower can easily emit sounds greater than the 80 dB limit, which is considered potentially hazardous, while jet plane takeoffs, rock band practice at four to six feet, and jack-hammers can surpass 120 dB. Hearing protection can certainly offer hearing perpetuation.
Treatment of hearing loss The treatment of hearing loss should be directed at the source of the deficit. Obviously, the treatment would be indicated for infections, TM perforations, ossicular abnormalities, tumors, and trauma. If, however, the reason for the hearing loss is sensorineural, hearing amplification (hearing aids) might be indicated. Hearing aids increase the volume of the external sounds and may help the patient hear better. Problems encountered include impacted cerumen buildup, otalgia, and the increased volume of background noises as well as the desired speech and sound. Cochlear implant surgery might be indicated in adults who have attempted hearing aids, and still have less than 50 percent recognition of spoken sentences, and have no medical contraindications to surgery. The cochlear implant is a medical apparatus that perceives sound, changes the sound to digital format, sends these signals to the cochlea, where electrodes bypass the damaged hair cells and stimulate the acoustic nerve which sends impulses to the brain for processing. This requires a surgery and follow-up visits for programming the speech processor for the appropriate level of electrode stimulation. An accommodation period is required for the brain to “learn” to process these new signals and recognize them as spoken language. Statistics on the numbers of deaf and hard-of-hearing are difficult to identify because many people are hesitant to acknowledge the condition. Estimates of 20 to 30 million Americans have deafness and public awareness programs are certainly indicated. Education is essential about hearing screening in the schools and newborn nursery to identify problems with learning and appropriate speech formation. Warning the
an Tagge, Textbook of Family Practice 6th Edition: Otolaryngology (Saunders, 2002); Betsy Sanford, and Peter C. Weber, “Etiology of Hearing Impairment in Children,” UpToDate, www.uptodate.com (cited March 29, 2006);Peter C. Weber, “Etiology of Hearing Loss in Adults,” UpToDate, www.uptodate.com (cited April 20, 2006); Peter C. Weber, “Evaluation of Hearing Loss in Adults,” UpToDate, www.uptodate.com (cited January 6, 2005); Peter C Weber, “Hearing Amplification in Adults,” UpToDate, www. uptodate.com (cited April 20, 2006).
See Also: Ear Disorders; Hearing Problems in Children. Bibliography. John C. O’Handley, Evan Tobin, and Bry-
Richard K. Ogden, D.O., FACOFP, FAAFP Kansas City University of Medicine and Biosciences
Death and Dying Death has always fascinated humankind. The interest on death and in the process of dying is more ancient than civilization itself. In fact, archaeological findings of burial sites and evidences of ritual funerals attest to this interest. Its inexorability and the unknown associated with it have long been focus of conjectures. The process of dying has always been a source of fear, not only due to its ultimate result, but also because of the suffering usually associated with it. While many fields of knowledge have been dedicated to the study of death throughout human history, the recent progresses of science and medicine have brought into discussion many issues regarding death and dying, such as palliative care and euthanasia or one’s right to dignity during the process of dying. The important aging of the world’s popula-
tion, in action in the last decades, has put death and dying into the forefront of societal attention. Extremely medicalized all over the world until recently, death is currently being more regarded as a natural and expected part of life—and the quest for a peaceful death—as a natural human right. Historic Perspectives The reality and ubiquity of death has had a profound impact in human psyche and civilization. The personalization of death as a figure or character has been present in the mythologies of many different cultures. The black-dressed skeleton with a scythe, well known in the United States, is only one of several images that came to use in different times and places, often reflecting popular values and beliefs toward death. The beliefs and attitudes concerning death have varied a great deal: The Latin term memento mori, first evoked in Roman antiquity and translated as remember that you are mortal, was popular for centuries, but its meanings varied in the course of the years. Originally associated with the ideal of carpe diem (seize the day), memento mori was an advice toward hedonism. The idea is present even in the Bible: “Eat and drink, for tomorrow we die!” (Isaiah 22:13), but as Christian theology developed and brought death and dying to the forefront of religious life, the idea that was to influence the whole Western civilization was the moralizing role of death. In a system of belief with emphasis on the afterlife where a soul could either be sent to heaven or hell, depending on the Christian success on avoiding sin. Memento mori became a warning advice: By remembering one’s own mortality, one would have it easier to uphold a pious life. In the mid-14th century’s Europe, the Black Death, a devastating pandemic, changed peoples’ views on life and death, with long-lasting effects. During the Black Death, anyone who seemed perfectly well could quickly die without apparent causes. In fact, the pandemia killed nearly two-thirds of the European population and virtually everyone was acquainted with victims of the disease, leading to deep cultural impacts. The uncertainty of life and the ubiquity of death came to populate the minds of medieval Europeans; as an example, the danse macabre, the dance of death, a popular allegory in which a personified Death danced with representatives of each segment of society of those times (typically an emperor, a king, a monk, a pope, a young
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boy, and a beautiful girl) was a popular remembrance of death not distinguishing between its victims. In the following years, the perceived need for spiritual comfort and a Christian death and the lack of sufficient Church personnel (the Church itself having suffered huge losses during the Black Death) resulted in the appearance of the Ars Moriendi (the art of dying), a book of rules and procedures to ensure a good death and on how to “die well,” i.e., according to the Christian principles and to reassure the entrance into Heaven. Apart from the solely religious issues, the book stated that people did not need to be afraid of death: As a pathway to Heaven, it was a good thing. The book oriented dying people on how to avoid different temptations common to the dying process and addressed friends and relatives on how to behave at deathbed. The Ars Moriendi became very popular and was the first of a series of guides to death and dying that were to influence Western culture toward a natural view of the process. Until a century ago, most Americans died at home in a process that was considered a normal event of life. With the relatively recent progresses of science, medicine, and sanitation, humanity became as capable as ever of prolonging life and avoiding death in many cases. The limit between a mild and a mortal disease became blunted when many severe diseases and conditions gained a perspective of cure, as it was the case for cancer. The same progress, nevertheless, has also contributed to important changes on how society views and deals with death. Once much more common in all age groups, death was viewed as a proper part of life: as mentioned above, a terminally sick person would often die at home, surrounded by family and friends. With death reduced to a medical event and more avoidable than ever, it progressively ceased to be considered such a normal part of life. Avoiding death became a medical challenge—not succeeding became almost a defeat. Today more than 80 percent of American deaths occur at a healthcare facility. Dying at a hospital, alone or surrounded by unknown, professionally acting people, became almost the rule. Death became a distant event, something most people may never expect to witness. This social distance led to a lack of knowledge of people in general about death and dying, which further contributes to the maintenance of such distance. Finally, a considerable amount of health resources is spent during the final weeks of life—frequently
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with curative intentions toward an incurable disease, which do not enhance quality of life—sometimes actually reducing it. This phenomenon that has been called therapeutic futility, diverts financial and human resources from uses that could benefit society. In the last few decades, this practice has started to be recognized as a menace to a person’s right to a peaceful death and a misuse of social resources. The perspective of prioritizing quality of life and suffering relief in terminal diseases is leading a worldwide discussion on what is to be considered a good death and what is the role of health professionals. Recognizing death Recognizing the exact moment of death has always been difficult. For a long time, death was defined as the cessation of breathing and heartbeats, but these may be quite difficult to detect in severely ill patients due to superficial breathing or an extremely slow heart frequency, which led to a myriad of tests used to diagnose recent death. Difficulties diagnosing cardiorespiratory arrest were overcome in the last century with the advent of the electrocardiograph, capable of accurately detecting the heart’s electrical activity or its absence. However, the recent use of cardiopulmonary resuscitation (CPR) and prompt defibrillation made cardiorespiratory arrest potentially reversible and thus not synonymous with death. Cardiorespiratory arrest then became known as clinical death. The quest for an early diagnosis of death, essential in many cases (e.g., the need for early removal of organs from donor in organ transplantation) led to the concept of brain death. With the recognition that the source of consciousness is the brain, this organ is considered the only part of the human body that is essential for what is called one’s self or individuality. Brain death is synonymous with death even with other organs still functioning. Diagnosing brain death, nonetheless, is often not trivial: With other organs functioning, the sole source of definite information concerns the brain itself and the physician has to demonstrate a state of permanent lack of brain activity. Many exam protocols are precise but not always present on site, especially in developing countries. In such cases, the delay in the diagnosis of death may harm or prevent transplantation.
Caring for a Dying Person A patient without perspectives of cure may be cared for and die at home, and more people are choosing this alternative. In this case, and to assure a peaceful death, it is of utmost importance that family and caregivers (who may be the relatives of the patient) be fully informed on the process of dying and the actions they will likely have to do during this time. Many times the problems leading to the failure of home care and dying at home lie in the lack of knowledge of the caregivers, that either may interpret expected events as unexpected or attribute a nonexisting suffering to them. Another common factor of failure lies in the difficulties in reacting to common situations, for example, the caregiver may take the patient to the hospital without real need. The medical estimation of the time of death is important for the patient and family to prepare for the process, but it is important to stress that there is no precise way to predict survival, because it varies in different individuals and in different diseases. The dying patient may experience different symptoms, because these depend on the cause underlying the process. Receiving information from the health team on those symptoms and the problematic situations likely to occur in a specific case is important for planning the home care and how to behave in both the expected and the troublesome events. During the process of dying, two kinds of events are distinguished: the physical phenomena linked to death and the psychological phases the terminally ill patient experiences. Although death assumes many forms, some physical features are common to anyone experiencing death from a chronic condition. As a person at the end stage of life becomes weaker, their appetite decreases and swallowing may be very difficult. As the time of death approaches, people may not be able to feed anymore and offering food may increase the patient’s distress with no benefit: At this stage, feeding will not do any good because the body is not able to process nutrients any longer. Consciousness variations are not always present. While some people early in the stage of dying become and remain unconscious until they die, other people may sleep and wake alternately and some retain consciousness until just before dying. Visions or hallucinations are common and normally not distressful,
when there is no need for medication. In either condition, they may still hear and listening to their loved ones may be a relief. Breathing changes are a common potential source of discomfort both for the patient and caregivers and range from none at all to severe shortness of breath; the breathing rate may be decreased or increased and breathing can be regular or irregular. When breathing discomfort is present, physicians usually have medications to alleviate them. Noisy breathing, also known as the death rattle, may arise due to the progressive inability to clear lung secretions. This symptom is often exuberant and may scare caregivers but cause no discomfort for the patient. Circulation is expected to progressively slow down and fail. In such process, it is common that extremities of the body, such as hands and feet, become cooler and bluish, indicating poor oxygen intake. Again, this is not uncomfortable for the patient and nothing needs to be done. The psychological stages through which a person with an incurable disease often passes include denial, anger, bargaining, depression, and finally acceptance. It has been demonstrated that both terminally ill patients and their family caregivers may pass through these phases, but this order, however, is only the most common: they may happen in any order and not all of them will necessarily happen to a person. It is important to notice that denial and anger may be natural, healthy initial stages of a future acceptance and not a sign of permanent distress. Psychological support for both patient, caregivers, and family may help them to accept a reality that they cannot change, decrease the despair and suffering that commonly follow a diagnosis of a fatal disease and allow people to pass through this difficult period as peacefully as possible. It may also facilitate the use of the remaining time prior to death to something enjoyable. Examples may include travels or other activities early in the course of disease or visiting a distant relative. Psychological support also helps people to say farewell to their loved ones and give a sense of closure to their lives. This sense appears to be important in most cultures both to the remaining ones and to the patients, who often decrease their sense of psychological discomfort by having the chance of closing their own lives.
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Palliative Care and Ethical Questions Palliative care is the field of medicine that studies interventions aimed at relieving suffering and increasing quality of life as opposed to traditional medicine, which has mostly pursued prevention and cure. Palliative care is not exclusive of the period of dying: on the contrary, it is indicated whenever a medical situation cannot be cured but relieved. During a terminal disease, it is possible that every medical intervention be directed to caring instead of curing and frequently, there are several options to relieve or decrease suffering up to the last moments of life. The knowledge on palliative care has given rise to a number of ethical questions regarding what treatment to offer a patient, because a problem will always be obviously incurable. Moreover, there are established therapeutic regimens that may be challenged to the benefit of the patient. One may take the example of cancer, which has been extensively studied and therapeutic protocols of treatment exist for most types of disease. Nonetheless, the predicted treatment may not be applicable to a frail elder patient with multiple diseases who may not support the burden of full chemotherapy that may enhance suffering without achieving cure. Informed consent is required for any kind of medical intervention unless in emergency situations and, thus, this concept changed how doctors deal with death and dying. Even in emergencies, advance patient directives can prevent the physician from starting cardiopulmonary resuscitation or using mechanical breathing support. The same is valid in many countries for the use of life supporting devices in people with no prognosis of cure or simply not desiring their use. Euthanasia, Orthothanasia, and Dysthanasia Euthanasia (from Greek for good death) is the practice of terminating one’s life when it is perceived as intolerable, generally due to suffering associated with a terminal disease. Euthanasia is to be practiced in a painless or minimally painful way, usually with a lethal injection, a drug overdose, or disconnection of life supporting devices. Euthanasia is a controversial practice because of conflicting religious, legal, and humanist views all over the world. Voluntary euthanasia occurs with the consent or request of either decisionally competent patients or their proxies. Nonvoluntary euthanasia occurs with-
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out the request or consent of either a competent patient or his or her proxy; in this case, the patient and proxies may not even be told of euthanasia and this is not considered a good practice even in countries where euthanasia is allowed. Involuntary euthanasia occurs with the objection of patient or surrogates; it occurs when practiced despite a specific refusal. Even in countries where euthanasia is accepted, involuntary euthanasia is considered murder. When a medical doctor does not practice euthanasia, it is often called mercy killing. It is important to notice that palliative care that may not intentionally contribute to death is not considered euthanasia (e.g., the use of strong opioid analgesics to relieve pain, contributing to respiratory failure). The same applies to not initiating supportive treatments that be either irrelevant for patient survival or refused by patient or proxy: opposed to the withholding of an initiated treatment this is not considered euthanasia. The set of medical and multidisciplinary practices that aim at promoting a peaceful death and relieving suffering is known in palliative care as orthothanasia (from Greek for correct death). Palliative care strongly opposes the use of every life-sustaining technique for keeping a terminally ill patient alive, which can actually prolong suffering. The same applies to not using analgesic or other distress-relieving drugs for fear of contributing to death. The set of measures exclusively aimed at prolonging life in spite of suffering—sometimes actually causing it—is considered a fault and has been termed dysthanasia, or bad death. Current Perspectives With the reality of population aging virtually everywhere, which will continue in the next decades, health issues related to elderly people became as important as never before. Death and dying is obviously not a topic exclusive to the elderly, but dying in old age may be a part of a successful and healthy life, while dying young is not, for most deaths in young age became preventable with the advances of sanitation and medicine. Moreover, the same progresses mean that most deaths throughout the world occur in the elderly and, therefore, the questions raised in death and dying are fundamental for geriatric care. Parallel to a better understanding of the process of dying, there have been efforts for the recognition
of unavoidable and incoming death and responsible and adequate use of medical resources. Nowadays, it is widely recognized within the scientific community that using advanced and invasive medical resources in terminally ill patients may be a therapeutic futility if not directed toward suffering relieving, the utmost aim in caring for those who are dying. SEE ALSO: Geriatrics; Kübler-Ross, Elisabeth; Pain. Bibliography. N. M. Goolam, “Euthanasia: Reconciling
Culture and Human Rights,” Medicine and Law (v.15/3, 1996); E. Kübler-Ross, On Grief and Grieving: Finding the Meaning of Grief through the Five Stages of Loss (Simon & Schuster, 2005); J. Ladbrook, “Caring for the Dying,” Nursing New Zealand (v.4/10, 1998); M. C. Long, “Death and Dying and Recognizing Approaching Death,” Clinics in Geriatric Medicine (v.12/2, 1996); M. M. Ross, “Palliative Care. An Integral Part of Life’s End,” Canadian Nurse (v.94/8, 1998); John Shinmers, ed., “The Art of Dying Well,” Medieval Popular Religion, 1000–1500, a Reader (Broadview Press, 1997) Thiago Monaco, M.D., Ph.D. University of SĂo Paulo Medical School, Brazil
Death Rate The death rate is a statistic that allows us to analyze either the total number of deaths or the number of deaths due to a specific cause in a defined population over a particular period of time. Death rates are usually expressed in terms of 1,000 or 100,000 population. The most basic concept of a death rate is the crude death rate, the total number of deaths per 1,000 people in a population over a period of time. So, for instance, if there are 600 deaths per year in a population of 100,000, the crude death rate will be 600/100,000, or 6/1,000. While the crude death rate gives some indication of the mortality profile of a country, it can be misleading. For instance, the crude death rate of Sweden might be higher than that of Haiti, despite longer life expectancy for each individual than in Haiti, because Sweden’s population is older, on average, and thus each individual is more likely to die in any given year. In order to gain a true sense of the overall mor-
Degenerative Nerve Disease
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The death rate analyzes either the total number of deaths or the number of deaths due to a specific cause over a period of time.
tality picture, one must instead use an age-adjusted death rate, which compares two rates as if they were based on the same population, or a life table which tabulates life expectancies at every age. In addition to the age profile of a nation, other factors that strongly influence the death rate are the rates of infant mortality (the number of deaths of children less than 1 year old/1,000 live births), child mortality, maternal mortality (the number of deaths due to childbearing/100,000 live births), overall nutritional standards, hygiene levels, access to medical care, access to safe drinking water, and overall levels of infectious disease. See Also: Death and Dying. Bibliography. Economic and Social Commission for
Western Asia, Demographic and Related Socio-Economic Data Sheets for Member Countries of the Economic and Social Commission for Western Asia as Assessed in 2000 (United Nations Publications, 2002); Mary A. Freedman and James A. Weed, eds., Vital Statistics of the United States: Mortality (DIANE Publishing, 1999); Russell O. Wright, Life and Death in the United States: Statistics on Life Expectancies, Diseases and Death Rates for the Twentieth Century (McFarland, 1997). Annie Dude University of Chicago
Neurons are populations of cells which transmit information as electrical-chemical currents. Together, they form a network termed the nervous system which serves to coordinate activities such as movement with sensation and motivation. Neurons themselves are post-mitotic which means that they have lost their ability to divide and produce more neurons. In other words, once a neuron is damaged, surrounding neurons are unable to replace the lost neuron. This characteristic, in conjunction with the lack of a rigorous stem cell population within which to replace damaged neurons, makes the nervous system highly sensitive to environmental assaults. Degenerative nerve disease is a pathological condition characterized by selective degeneration of groups of nerves. The general dogma that describes the progression of nerve degeneration begins with the accumulation of protein aggregates that are resistant to normal mechanisms of protein degradation. These proteins often have important functions in the nondiseased state. At high concentrations, however, they form insoluble sheets or aggregates which are toxic to the neuron within which they reside. In an unknown mechanism, these aggregates lead to the death of their host neuron. The disease state begins when gross neuronal death is detectible through functional deficit. A major characteristic of degenerative nerve diseases is that they affect select groups of neurons, leading to selective loss of function. Thus, for convenience, degenerative nerve diseases will be grouped according to area or type of neuron afflicted. Degenerative disease of the cortex Alzheimer’s disease (AD) is a degenerative disease afflicting neurons of the cerebral cortex. Loss of cortical neurons initially manifests as impairment of higher cerebral function which progresses to severe memory loss with disorientation. The final outcome of AD involves the complete loss of higher cerebral function which at autopsy presents as massive cerebral atrophy. These symptoms do not usually manifest in patients before they reach the age of 50. With the aging population, AD has turned into the most common cause of dementia in the elderly. AD is thought to be sporadic in causality although familial cases do exist. Currently, the accumulation of
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two major proteins has been implicated in leading to the development of AD: Aβ amyloid and tau protein. Aβ amyloid is an integral membrane protein which can be cleaved into two species, one of 40 amino acids in length, the other of 42. Although the method by which Aβ amyloid induces neuronal death is unknown, Aβ amyloid 40 is thought to be protective against AD induced by Aβ amyloid 42. Presenilin is a proteolytic enzyme responsible for cleaving and clearing Aβ amyloid protein. Thus, mutations in presenilin are often responsible for a patient’s AD. Tau, on the other hand, is a protein normally associated with microtubules in axons of neurons, that serve to facilitate vesicular transport. In the disease state, tau is hyperphosphorylated, its accumlation leads to the formation cytoplasmic neurofibrillary tangles. Aggregates of these proteins in the cortex (frontal, parietal, and temporal lobes) leads to the development of neuritic plaques of twisted neural axons visible upon biopsy. Because Aβ amyloid is coded for on chromosome 21, genetic predisposition to AD is associated with patients who suffer from Down Syndrome. Almost all patients with trisomy 21 and live into their 40s develop AD. Not only are they almost guaranteed to suffer from AD, because of increased production of Aβ amyloid, but symptoms of dementia also manifest earlier than patients with only two copies of the allele. Allele E4 of ApoE has also been established to predispose individuals to AD. Located on chromosome 19, this gene codes for a product with high affinity for Aβ amyloid. Patients with ApoE-induced AD manifest symptoms later in life. Degenerative disease of the basal ganglia Parkinsonian diseases (PD) are a collective group of chronic progressive diseases affecting dopaminergic pathways in the striatum. The striatum, which consists of the substantia nigra, caudate, putamen, globus pallidus, subthalamus, and thalamus, regulates voluntary muscle movement. As a result, symptoms of PD include involuntary tremors followed by periods of stiffness, as well as poor coordination and difficulty balancing. Dementia, depression, and visual-spatial impairment are also associated with PD. Idiopathic Parkinson’s disease is typically sporadic in origin, manifesting equally in men and women
between the ages of 45–65. Biopsies reveal neurons of the substantia nigra (dopaminergic) and locus ceruleus (norepinephrine secreting) to be degenerated, filled with cytoplasmic, eosinophilic inclusions termed Lewy bodies. Lewy bodies are aggregates of damaged neurofilaments. Selective loss of dopaminergic neurons has directed the development of PD therapies to revolve around dopamine replacement. However, dopamine’s suspected involvement with schizophrenia explains why many of these drugs produce schizoid side effects. Other etiologies of damage to the substantia nigra include pesticides, ischemic injury, chronic carbon monoxide poisoning, Wilson’s disease and encephalitis. Huntington’s disease (HD) is another common neural degenerative disease that affects the striatum. In particular, the caudate, putamen and globus pallidus are severely atrophied in HD, leading to symptoms such as chorea (involuntary dance-like rhythmic movements), muscle rigidity, and dementia. The long search for the protein responsible for this disease has come up with the Huntington gene, located on chromosome 4. Inherited in an autosomal-dominant manor, the Huntington gene consists of a cluster of trinucleotide repeats which increase in quantity with each successive generation, termed genetic anticipation. Interestingly, the number of repeats tends to stay the same on the allele inherited by the mother, while it increases on the allele inherited by the father. The Huntington allele is considered mutant if it possesses more than 40 trinucleotide repeats because it is at this point that the protein becomes toxic to the neurons within which it resides. Although symptoms typically appear between the ages of 35–45 years, the more repeats that exist in the Huntington gene, the earlier the disease manifests. Degenerative disease of the spinal cord Lou Gehrig’s disease, also known as amyelotrophic lateral sclerosis, is a degenerative disease that involves upper and lower motor neurons. Although most cases are sporadic, genetic predisposition has been associated to mutations in the superoxide dismutase I gene (chromosome 21). Symptoms of both upper motor neuron (positive Babinski sign, spastic reflexes) and lower motor neuron (muscle weakness
Dementia
and atrophy) damage appear usually between 40–60 years of age. Although the above-mentioned diseases are the most common types of degenerative nerve disease, many more afflict our nervous system. Because our nervous system is so sensitive to environmental assaults, much effort in the scientific community is dedicated toward developing therapies including either reviving endogenous stem cells to replace damaged tissue or implanting neural progenitors that have been cultured from stem cells. See Also: Alzheimer’s Disease; Downs Syndrome; Hun-
tington’s Disease; Parkinson’s Disease.
Bibliography. Y. Furukawa, et al., “Disulfide Cross-
Linked Protein Represents a Significant Fraction of ALSAssociated Cu, Zn-superoxide Dismutase Aggregates in Spinal Cords of Model Mice,” Proceedings of the National Academy of Sciences. (v.103/18, 2006); K. Kieburtz, et al., “Trinucleotide Repeat Length and Progression of Illness in Huntington’s Disease,” Journal of Medical Genetics (v.31, 1994); Mark Rapoport, et al., “Tau is Essential to Beta-Amyloid-Induced Neurotoxicity,” Proceedings of the National Academy of Sciences (v.99/9, 2002); DunSheng Yang, et al., “Examining the Zinc Binding Site of Amyloid-β Protein,” European Journal of Biochemistry (v.267, 2000). Kimberly Gokoffski University of California, Irvine
Dementia Dementia is a progressive loss of cerebral function which may result in a generalized disturbance in function. It is common in the developed world and its prevalence is increasing as the age of population is increasing. It involves more than one area of cerebral function, for example, memory, language, and judgment, and may result in severe dysfunction of daily life. The prevalence of dementia is approximately 6 percent in those over 65 years and 30 percent of people aged over 90 years. Dementia is rare before the age of 60. Symptoms of dementia include loss of memory,
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personality changes, and loss of executive function such as the ability to make decisions. There are several diseases that cause dementia. The most common cause is Alzheimer’s disease (AD); it accounts for 30 to 50 percent of dementia. AD is characterized early on by neuropathological changes, primarily in the hippocampus. It is stated that AD pathology is more likely to be clinically expressed as dementia in women than in men. AD is a neurodegenerative disease with histopathological features such as loss of synapses and cells and presence of amyloid plaques and neurofibrillary tangles (NFTs). NFTs are pathological protein aggregates in neurons; they are associated with the microtubule associated protein tau in the cerebral cortex particularly in the temporal lobe. The presence of NFTs may contribute to the cognitive decline such as impairment in language (aphasia), skilled movements (apraxia), and recognition (agnosia). Other symptoms of AD include loss of memory and deterioration of musculature and mobility leading to unsteady gait. AD patients generally have reduced acetylcholine activity, high concentrations of homocysteine, and folate deficiency leading to increased risk of dementia and cognitive decline. Higher plasma vitamin B-12 may reduce the risk of homocysteine-associated dementia. Factors known to increase risk of the AD include mutations in the amyloid precursor gene and the apolipoprotein E (apoE) genotype. The apoE gene has three alleles called ε2, ε3, and ε4. The ε4 allele (chromosome 19) accelerates the age of onset of familial AD and increases the risk of developing late-onset “sporadic” AD. Its presence has been associated with an increase in β-amyloid protein (Aβ) senile plaques and neuritic plaques. ApoE in the normal brain is involved in the transport of cholesterol, redistributing lipids among CNS cells for normal lipid homeostasis, repairing injured neurons, maintaining synapto-dendritic connections, and scavenging toxins. ε4 binds to Aβ; this interaction prevents toxic aggregation of Aβ. This property is lost in AD, thus leading to Aβ accumulation and resulting plaque formation. ε4 is also associated with small vessel arteriolosclerosis and microinfarcts of the deep nuclei perhaps as a result of the plaque accumulation. Aβ protein is produced from proteolytic cleavages (using β and γ secretases) of amyloid precursor protein (APP). Aβ accumulates in the brain cortex and hippocampus of patients with AD and self-aggregates to form toxic oligomers causing neurodegeneration
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Another risk factor for AD is mutations in the presenilin gene. Presenilin mutations are the main cause of familial disease. These mutations seem to result in a gain of toxic function, and a partial loss of function in the gamma-secretase complex, which affects several downstream signaling pathways. The loss of function of presenilin causes incomplete digestion of the Aβ and might contribute to an increased vulnerability of the brain, thereby explaining the early onset of the inherited form of AD. Other risk factors of AD include head injury, Down syndrome, lower premorbid intellect, and proneness to psychological distress; chronic stress is associated with hippocampal damage and impaired memory in humans. AD is a devastating disorder for which there is no cure or effective treatment; however, various pharmacological treatments are currently employed. AD generally has a poor prognosis with a median life expectancy after diagnosis of five to six years. The second most common cause of dementia is vascular dementias which are a group of syndromes relating to cardiovascular risk factors such as smoking, arteriosclerosis, hypertension, and diabetes. The disease occurs as a result of large hemispheral infarcts and is also associated with widespread small ischemic or vascular lesions (microinfarcts, lacunes) throughout the central nervous system with predominant subcortical lesions in the basal ganglia and white matter or in regions such as the thalamus and hippocampus. Patients who have had a stroke are at increased risk for vascular dementia. Patients often have impaired memory and altered behaviors; other signs depend on infarction distribution. Another cause of dementia is Lewy body disease, characterized by the presence of structures called Lewy bodies which are round deposits that contain damaged nerve cells. These Lewy body proteins are found in an area of the brain stem where they deplete the neurotransmitter dopamine, causing Parkinsonian symptoms. The brain chemical acetylcholine is also depleted, causing disruption of perception, thinking, and behavior; patients also have visual hallucinations and instability. Prognosis is fairly poor, as most patients survive for about six years after diagnosis. Rare causes of dementia include frontotemporal dementia, alcohol related, HIV infection, syphilis, subdural hematoma, and some forms of cerebral tumors. People with multiple sclerosis, motor neuron
disease, Parkinson’s disease, and Huntington’s disease may also be more likely to develop dementia. Dementia is associated with poor prognosis in patients; most patients eventually need continuous help with everyday activities. Dementia is an important public health problem with devastating consequences for the patient and an increased burden on families. SEE ALSO: Alzheimer’s Disease; Parkinson’s Disease. Bibliography. E. Ifeachor, et al., “Biopattern Analysis
and Subject-Specific Diagnosis and Care of Dementia,” Proceedings of the 27th Annual International Conference of the IEEE EMBS, Shanghai, China, September 1–4, 1005. Farhana Akter King’s College London
Demographic Transition Demographic transition is a term coined by F. W. Notestien in 1945 to describe the changes that occur in a population as it moves from a premodern to a modern society, or from a developing to an industrialized economy. Developing countries are characterized by a population in which there are high birth rates and high death rates. The age structure of the population is pyramidal and there are far more children than elderly. In the first stage of the demographic transition, as per capita income rises, death rates fall due to factors that may include improved hygiene, nutrition, and healthcare. Birth rates (fertility rates) remain high and there is rapid population growth. After some time, birth rates begin to decline as families decrease the number of children they wish to have. They invest more resources into fewer children and realize that most children will survive to adulthood. A new stable population state is eventually reached in which both birth and death rates are relatively low, and the age structure of the population is rectangular. The epidemiologic transition that generally accompanies and contributes to the demographic transition involves a change in the patterns of health and disease in a population. Developing countries generally have high infant, child, and maternal mortality rates. In these countries, acute and infectious diseases such
Dengue
as pneumonia, tuberculosis, and meningitis are common causes of death. In industrial countries, infant, child, and maternal mortality tend to be relatively low, and cancer, heart disease, and stroke are the most common causes of death. These insidious and chronic diseases are often related to risk factors such as diet, smoking, and sedentary lifestyle. Cancers are a common cause of death in pre- and posttransition populations; however, the types of cancer vary. In developing countries, cancers are primarily those caused by microorganisms—liver, cervical, stomach, and nasopharyngeal neoplasms. However, cancers of the developed world—lung, colon, and breast—may be related to the risk factors previously mentioned. Deaths from motor vehicle accidents generally increase during the early transition period as there are more motorized vehicles in operation, and decrease in the posttransition period as laws and technology improve the safety of vehicle operation. There is a great deal of variability in how each country and/or population experiences the demographic and epidemiologic transitions based on political and social structure, and resources. There is also great debate as to whether economic growth or other social or external factors are primarily responsible for these changes. Emerging diseases, social upheaval, and other dramatic events can interrupt or reverse the transition processes. For example, the HIV epidemic and wars have stalled reductions in mortality in sub-Saharan Africa. Similarly, massive social and healthcare system disruption have moved countries of the former Soviet Union back into a state in which vaccine-preventable and infectious diseases are a significant cause of morbidity and mortality. The concepts of demographic and epidemiologic transition are critical to understanding the health needs and the determinants of health of a population. They are also useful in designing health interventions and for health infrastructure, human resource, and social infrastructure planning. SEE ALSO: Third World. Bibliography. P. F. Basch, Textbook of International Health,
2nd ed. (Oxford University Press, 1999); T. Kue Young, Population Health (Oxford University Press, 2005). Barry Pakes, M.D., M.P.H. University of Toronto
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Dengue Dengue is a mosquito-borne viral infection of mostly tropical and subtropical urban and semiurban areas that causes fever. In the last half of the 20th century, incidence increased 50-fold. Dengue is endemic in over 100 countries although southeast Asia and the west Pacific are most severely affected. Two-fifths of the world’s population, including over 1 billion children, are exposed to the female Aedes mosquitoes that transmit the virus. There are approximately 50 million infections a year with 1 percent of infections developing into the potentially lethal dengue hemorrhagic fever (DHF). DHF has a global mortality rate of 5 percent. There is no treatment or vaccine for dengue, although with appropriate supportive therapy, mortality can be reduced to less than 1 percent. Although clearing an infection results in immunity against a particular serotype, there is only partial, transient cross-protection and an individual can be infected with another serotype. Sequential infection increases the probability of developing DHF. History The first reported cases and epidemics of dengue occurred in the 1600s. Dengue was initially considered a mild, nonfatal travelers’ disease. By 1845, global pandemics arose and continue today. During the 20th century, distribution and density of Aedes mosquitoes expanded because of human travel and trade. Rapid rise in urban population and unplanned urbanization led to inadequate solid waste disposal and unhygienic water storage, creating mosquito-breeding grounds. While eradication efforts began in the mid-1900s, they were discontinued, and reinfestation of Aedes mosquitoes occurred in larger distribution and density than previously. By 2005, dengue had a global distribution comparable to malaria. Transmission and Virology The most common vector is the Aedes aegypti mosquito, which has global distribution, though Aedes albopictus, found in Africa, the Americas, and Europe, is also a vector. Aegypti is a daytime feeder that prefers humans and lays eggs preferentially in artificial containers such as used tires and water storage drums. Female Aedes mosquitoes acquire the virus by feeding on an infected human and shed the virus during subsequent feeding.
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The dengue virus, a flavivirus, is the most widespread arthropod-borne virus, or arbovirus. Other mosquitoborne flavivirus infections include yellow fever and West Nile disease. All four dengue serotypes have a global distribution. There is a weeklong incubation period in mosquitoes prior to infectivity. For a week after a human is infected, the virus silently replicates in organs such as the thymus and then infects white blood cells. Viremia is detectable for approximately five days. Mosquitoes acquire the virus during this time. Illness will develop about two days after onset of viremia and continue for about a week. Dengue infection during pregnancy does not cause any congenital malformations. Dengue virus cannot be transmitted between humans. Dengue infections peak in winter.
Environmental management includes adequate solid waste disposal and improved water storage. Chemical management focuses on applying insecticides to larval habitats periodically. Insecticide spraying to kill adult mosquitoes has transient and variable effect because insecticide may not penetrate indoor habitats. Aedes mosquitoes are resistant to organochloride sprays and ultralow-volume fumigation is ineffective. Active surveillance of mosquito populations, habitats, and susceptibility is essential to prevention of dengue.
Symptoms, Diagnosis, and Treatment Presentation is age dependent, with children experiencing a milder infection. The three categories of dengue fever, in increasing severity, are fever, dengue fever, and DHF. Fever is the most common presentation. Dengue fever also presents with headache, muscle and joint pain, nausea, vomiting, and rash. Weakness, malaise, and anorexia may persist for several weeks. Rarely, patients experience hemorrhagic manifestations including ruptured capillaries, bruising, and bleeding of gums and nose. DHF affects mostly children and is characterized by fever, hemorrhagic manifestations, low platelet count, and objective evidence of “leaky capillaries,” such as an elevated hematocrit or effusions. Without treatment, more than one in five patients dies. Fever in DHF patients can be as high as 41 degrees C (106 degrees F). The most severe form of DHF is dengue shock syndrome. After three to six days of fever, there is an abrupt temperature change, signs of circulatory failure, hypotensive shock and death within 12 to 24 hours. Blood and urine tests showing elevated hematocrit, low albumin, or microscopic blood in urine are signs of dengue. Travel history can be important in diagnosis. Intensive supportive therapy focuses on maintaining circulating fluid volume. Treatment also includes rest, mosquito barriers, and fever and pain relief. Hospitalization is required when severe hemorrhagic manifestations or shock are present.
Bibliography. Centers for Disease Control Division of
Prevention and Control Because eradication is believed unattainable, efforts concentrate on controlling mosquito populations.
SEE ALSO: Hemorrhagic Fever; Infectious Diseases (Gen-
eral); Medical Entomology; Mosquito Bites; Viral Infections; Virology.
Vector-Borne Infectious Diseases (CDC-DVBID), “Dengue Fever Publications,” http://www.cdc.gov/ncidod/dvbid/ pubs/dengue-pubs.htm (cited January 2007); World Health Organization (WHO), “WHO: Dengue,” http://www.who. int/topics/dengue (cited January 2007). Rishi Rattan University of Illinois–Chicago
Denmark With a per capita income of $34,800, Denmark is the 13th richest country in the world with a high standard of living and a strong safety net for the population. Danes are financially protected against illness, unemployment, and aging. Benefits in Denmark are not totally dependent on earlier employment, and programs are financed by taxes and duties. The government subsidizes housing and child-related expenses. Specific services involve health services, day care, and home help. The United Nations Development Programme (UNDP) Human Development Reports rank Denmark 15th among nations of the world in overall quality of life issues. Unemployment stands at 5.7 percent. There is virtually no poverty in Denmark, but 12 percent of females and 11 percent of males earn less than 60 percent of the median income. Primary and secondary schooling are available to all students, and enrollment is over 100 percent.
Dental Health
In the post–World War II era, the Danish government updated existing programs and created new ones as Denmark became a social welfare state. For instance, the National Pensions and Disablement Plan of 1957 guaranteed pensions to all citizens. Amendments in 1964 required workers to pay into the Supplementary Pension Fund. Compulsory health insurance was introduced in 1973, guaranteeing cash subsidies for Danish workers who become ill. Three years later, the Social Assistance Act was passed, enacting fixed rates for recipients. The government is concerned with the well-being of the population, and families receive a good deal of protection in Denmark. All females are eligible for maternity leave for four weeks before and 14 weeks after birth. Fathers may take up to two weeks leave during the 14-week period, and 10 weeks leave may be shared between both parents. The new parents receive a per diem allotment, which may amount to full salary. Family allowances are given to all families with children under the age of 18, and payments are increased for single-parent families. In 2002, the “Healthy throughout Life” plan announced that 11 ministries were working together to increase life expectancy, minimize inequalities in health, and improve the overall quality of health among the population. Target areas included smoking and obesity, and the government expressed continued commitment to reducing incidences of cancer, osteoporosis, and chronic obstructive pulmonary disease. The Danish government spends one percent of the total budget on healthcare. Nine percent of the Gross Domestic Product (GDP) is spent on healthcare at a rate of $2,762 (international dollars) per capita. Some 83 percent of total health expenditures are provided by government funding. Private sector expenses account for 17 percent of total spending, and 92.50 percent of that amount involves out-ofpocket expenses. There are 2.93 physicians, 10.36 nurses, 0.22 midwives, 0.83 dentists, and 0.49 pharmacists per 1,000 population in Denmark. The population of 5,450,000 experiences a life expectancy of 77.79 years, and women outlive men an average of five years. Only one percent of the population over the age of 15 is unable to read and write. The entire population has access to safe drinking water and improved sanitation. Birth control is practiced by 78 percent of female Danes, and women give birth to an average of 1.74 children each. All births are at-
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tended by skilled attendants. The adjusted maternal mortality rate of five deaths per 100,000 live births is one of the lowest in the world. Denmark has the 17th lowest infant mortality rate in the world at 4.51 deaths per 1,000 live births. Between 1990 and 2004, infant mortality was cut in half, dropping from eight to four deaths per 1,000 live births. During that same period, under-five mortality decreased from nine to five deaths per 1,000 live births. Five percent of all infants are underweight at birth. Immunization rates are predictably high, and 96 percent of infants are vaccinated against measles. Immunization rates for diphtheria, pertussis, and tetanus (DPT1 and DPT3), polio, and Haemophilus influenzae type B are reported at 95 percent. Denmark is highly industrialized, and air pollution from vehicle and power plants poses a major health threat. The North Sea has been polluted with nitrogen and phosphorus, and drinking and surface water sources are threatened by animal wastes and pesticides. The adult prevalence rate of HIV/AIDS is 0.2 percent in Denmark. While 5,000 people are living with the disease, less than 100 have died from HIV/ AIDS or its complications. Meningococcal disease surfaced in Denmark in 2001, and influenza outbreaks occurred in 2003 and 2004. See Also: Cancer (General); Chronic Obstructive Pulmo-
nary Disease (COPD); Osteoporosis.
Bibliography. Spencer Di Scala, Twentieth Century
Europe: Politics, Society, Culture (Boston: McGraw-Hill, 2004); Sandra Halperin, War and Social Change in Modern Europe: The Great Transformation Revisited (New York: Cambridge University Press, 2004); Martin A. Levin and Martin Shapiro, editors, Transatlantic Policymaking in an Age of Austerity: Diversity and Drift (Washington, D.C.: Georgetown University Press, 2004). Elizabeth R. Purdy, Ph.D. Independent Scholar
Dental Health Dental health emcompasses care of the teeth, jaws, soft structures of tongue, lips and oral mucosa (the soft
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pink covering inside the mouth). Teeth are made up of four types of tissue—enamel, dentin, pulp and cementum. Enamel covers the visible part of the tooth; it is the hardest body substance and does not regrow or repair itself when damages. The dentin is the calcified tooth core surrounding the pulp, made up of connective tissue, blood supply and nerves. Dentin continues to grow in healthy teeth. Cementum covers the root of the tooth and is made up of connective tissue to assist in anchoring the tooth to the jaw and cushion the impact of chewing. For optimal dental health, individuals should brush not only their teeth, but all soft surfaces of the mouth and tongue. Flossing between the teeth, wearing a mouthguard for sports, maintaining good nutrition are also instrumental in dental health. In addition to home care, the dental health team will keep teeth healthy and treat pain or injuries. The professional team may include a dental hygienist, a general dentist and a variety of specialists as needed. Dental problems Tooth decay. Dental cavities consist of decay caused by infectious bacteria—the most common being Streptococcus mutans. The bacteria feeds on sugars in foods and produces acids that can dissolve the enamel. The bacteria can also form plaque that sticks to teeth and dental work. Cavities are holes resulting from the disease from destruction of enamel and penetration into the dentin. Prevention includes removal of food particles by brushing and flossing, and routine dental visits for cleaning and removal of plaque and tartar. Treatment for lesions that haven’t formed cavities include using fluorides and sealants to help maintain the enamel. If a cavity has formed, restoration includes fillings or crowns. When the decay has reached the pulp a root canal will be performed Malocclusion. Biting (occlusion) is how teeth come together. Bite problems include teeth spacing, position of teeth, and protruding or recessing teeth. To repair these issues, an orthodontist will create braces or brackets to apply pressure to teeth (one tooth or a group) to move the teeth into alignment by reshaping the bone growth to hold the root. The process takes less time in children. In more severe cases of malocclusion, oral surgery may be necessary.
Enamel covers the visible part of teeth; it is the hardest substance in the human body and does not regrow or repair damage.
Periodontal disease. A group of diseases of the hard and soft tissue supporting structures. Bacteria found in the crevices of the gum causes infections related to the disease. Gingivitis is the first stage, and causes gums to become red, swollen, and bleed easily. In its early stages, gingivitis can be eliminated by brushing and flossing daily to remove plaque. Left untreated, gingivitis can progress to periodontitis, when bacteria attack the bone and tissue supporting the teeth. Inflammation of the bone and hard tissue is called periodontitis; if the bone dissolves, the teeth could loosen or fall out. Treatment includes cleansing (with scaling or root planing) to remove plaque and tarter on the tooth and below the gumline, and surgery to clean the roots or for restoration (reducing pocket depth, gum grafts, bone grafts). Tooth grinding (bruxism) is the grinding and clenching of the teeth. Symptoms might include abnormal tooth wear or damage, gum inflammation, pain while chewing, infection and temperomandibular disorders (TMJ with limited jaw opening and muscle tenderness in the jaw area). Treatment depends on underlying cause and might include stress reduction, medication, or oral devices to prevent grinding, and in the case of severe damage, surgery might be required. Wisdom teeth are the third molars. In some they occur in the mouth properly with ample room. In others, the third molar may not come through the surface of the gum, cause cysts or crowd other teeth, and surgical removal may be necessary.
Department of Energy (DOE)
In the event of tooth loss from an accident or progression of periodontal disease, false teeth (dentures or implants) must be fabricated to enable chewing. Prosthodontists specialize in creating and inserting prosthodontics (dentures, tooth implants, and other types of artificial dental structures such as crowns or bridges). Cosmetic Dentistry seeks to improve the appearance of the teeth and includes stain removal using bleaching, laser or light therapy, reshaping the teeth and gums, bonding (applying resin to a tooth to increase the length of the tooth, or to fill a gap) and applying veneers to the surface of the tooth. see also: Mouth disorders; Oral Surgeon. Bibliography. Robert K. Jackler, MD and Michael J. Ka-
plan MD, “Ear, Nose & Throat” Current Medical Diagnosis and Treatment (Lange Medical Books, 2004); Sadie S. Mestman, D.M.D. and Ariella D. Herman Ph.D. What to do for Healthy Teeth (Institute for Healthcare Advancement, 2004); Rebecca W. Smith and Faculty of the Columbia University School of Dental and Oral Surgery, Columbia University School of Dental and Oral Surgery Guide to Family Dental Care (W.W. Norton & Co, 1997); Lyn Michaud Independent Scholar
Department of Energy (DOE) The origins of the Department of Energy (DOE) can be traced to the Manhattan Project and the race to develop the atomic bomb during World War II. In 1942, the U.S. Army Corps of Engineers established the Manhattan Engineer District to manage the project. Following the war, the Atomic Energy Act of 1946 created the Atomic Energy Commission, which took over the Manhattan Engineer District’s sprawling scientific and industrial complex. In response to changing needs in the mid-1970s, the Atomic Energy Commission was abolished and the Energy Reorganization Act of 1974 created two new agencies: the Nuclear Regulatory Commission to regulate the nuclear power industry and the Energy Research and Development Administration to manage the nuclear weapon, naval
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reactor, and energy development programs. However, the extended energy crisis of the 1970s soon demonstrated the need for unified energy organization and planning. The Department of Energy Organization Act brought the federal government’s agencies and programs into a single agency. The DOE, activated on October 1, 1977, assumed the responsibilities of the Federal Energy Administration, the Energy Research and Development Administration, the Federal Power Commission, and parts and programs of several other agencies. The Department provided the framework for a comprehensive and balanced national energy plan by coordinating and administering the energy functions of the federal government. The Department undertook responsibility for long-term, high-risk research and development of energy technology, federal power marketing, energy conservation, the nuclear weapons program, energy regulatory programs, and a central energy data collection and analysis program. Over its two-decade history, the Department has shifted its emphasis and focus as the needs of the nation have changed. During the late 1970s, the Department emphasized energy development and regulation. In the 1980s, nuclear weapons research, development, and production took a priority. Since the end of the Cold War, the Department has focused on environmental cleanup of the nuclear weapons complex, nonproliferation and stewardship of the nuclear stockpile, energy efficiency and conservation, and technology transfer and industrial competitiveness. In the 21st century, the DOE contributes to the future of the nation by ensuring energy security, maintaining the safety and reliability of nuclear stockpile, cleaning up the environment from the legacy of the Cold War, and developing innovations in science and technology. Included under the DOE are a number of organizations dedicated to health and safety issues as they relate to energy sources and patterns of consumption. In 1989, the DOE created the Office of Environmental Management (EM) to mitigate the risks and hazards posed by the legacy of nuclear weapons production and research. Although the nation continues to maintain an arsenal of nuclear weapons, as well as some production capability, the United States has embarked on new missions. The most ambitious and far ranging of these missions is dealing with the environmental legacy of the Cold War. Like most industrial and manufacturing operations, the nuclear complex has generated waste,
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pollution, and contamination. However, many problems posed by its operations are unique. They include unprecedented amounts of contaminated waste, water, and soil, and a vast number of contaminated structures that will remain radioactive for thousands of years. Similarly, the Office of Civilian Radioactive Waste Management (OCRWM) is a program of the DOE assigned to develop and manage a federal system for disposing of spent nuclear fuel from commercial reactors and high-level radioactive waste from activities related to national defense. The Office of Health and Safety and Security (HSS) focuses on maintaining and improving worker health and safety policies and assisting line management in interpreting policies and implementing worker health and safety programs. This office addresses Department-wide safety issues that impact multiple DOE sites and that would benefit from a Department-wide approach to resolution. The HSS has four subordinate offices. One office focuses on worker safety and health policy development, maintenance, and interpretation. A second office focuses on technical assistance and issues management, and will be the focal point for interface with the line management program offices, field elements, and stakeholders. The third office manages studies that evaluate domestic health effects to include health surveillance, screening, and studies. Domestic health studies, surveillance, and screening examine current and former worker health and health effects and ensure this information is used to protect workers and the public and to continuously improve worker health and safety policies. This office also supports the Department of Labor in the implementation of the Energy Employees Occupational Illness Compensation Program Act (EEOICPA). The fourth office examines the effects on populations from U.S. nuclear weapons testing or accidents and operations involving radiological materials and other international health studies. These offices work together with a major focus on helping the program offices and field elements solve problems and improve safety programs and performance. The combination of these functions into a single office with a primary mission of worker health and safety policy and technical assistance enables the HSS to focus on helping the program offices and field elements to solve the highest priority health and safety issues and to direct DOE support
resources to where they are most needed. The HSS maintains a program designed to assess the health impacts of Energy operations on employees exposed to airborne concentrations of beryllium. Energy facilitates the initiation of an integrated interagency CBD research agenda leading to improved diagnosis, prognosis, and treatment of this disease. Energy departmental elements responsible for protection and control measures for current workers, compensation for individuals who have developed CBD, and CBD research, work closely with other agencies conducting related activities. The DOE is committed to safe operation of its nuclear facilities and activities. The Department’s Office of Nuclear and Facility Safety Policy establishes nuclear safety requirements and associated guidance for nuclear facilities and activities through a combination of public rules and DOE directives. The DOE also works with nongovernmental organizations to develop standards that can be used to maintain and enhance the safety of America’s facilities and activities. The Department’s overall goal in relation to its nuclear safety enforcement is to improve nuclear safety performance throughout the Department’s programs, sites, and contractors. Additional statutory responsibilities include enforcement of the Worker Safety and Health Program in the same manner that the nuclear safety rules are enforced. One of the desired outcomes of this program is to promote proactive behavior on the part of contractors with the overall goal, remaining the improvement of nuclear safety performance. See ALso: Environmental Protection Agency (EPA). Bibliography. United States Department of Energy,
www.energy.gov (cited October, 2006); United States Department of Energy, Department of Energy 1977–1994: A Summary History (Office of Human Resources and Administration, Executive Secretariat, 1994); United States Department of Energy, Report No. 11—Department of Energy Environment, Safety, and Health Initiatives Related to Nuclear Safety (U.S. Department of Energy Internal Working Group, Office of Environment, Safety, & Health, 1995); United States Environmental Protection Agency, Setting Priorities, Getting Results: A New Direction for the Environmental Protection Agency. Report to Congress (National Academy of Public Administration, 1995); United States
Department of Health and Human Services (HHS)
Office of Technology Assessment, Hazards Ahead: Managing Cleanup Worker Safety and Health at the Nuclear Weapons Complex (U.S. Office of Technology, 1993). Ben Wynne, Ph.d Gainesville State College
Department of Health and Human Services (HHS) The United States Department of Health and Human Services (DHHS) is the umbrella organization for a number of government agencies that deliver social services to Americans, especially to the most vulnerable segments of the population. The roots of HHS can be traced to the creation of the Cabinet-level Department of Health, Education, and Welfare (HEW) in 1953 under President Dwight D. Eisenhower. In 1979, under President Jimmy Carter, the Department of Education assumed Cabinet status, and the Department of HEW was transformed into the Department of Health and Human Services. The Secretary of Health and Human Services is responsible for overseeing implementation of more than 300 programs that deal with issues such as health and social science research, disease prevention, food and drug safety, health coverage for and financial assistance to the elderly, disabled, and economically disadvantaged, infant health, preschool education and services, faithbased community initiatives, child abuse, domestic violence, home care and nursing home care, health services for Native Americans and Native Alaskans, and medical and emergency preparedness. Operating under a budget of $698 billion (fiscal year 2007), HHS receives 25 percent of national government outlays; and through the Medicare and Medicaid programs alone, HHS affects the lives of a fourth of the population. Data collected through HHS are a major determinant in policy and budget decisions at all levels of government. In addition to functions carried out by eight public health service agencies, three human service agencies, and 11 operating divisions, HHS funds services administered by state, local, and county governments and by private sector grantees. HHS public health services agencies include the National Institutes of Health, which is the nation’s chief
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medical research organization; the Food and Drug Administration, which oversees the safety and reliability of foods, drugs, and cosmetics; the Centers for Disease Control and Prevention, which protects public health through prevention and control of diseases, injuries, and disabilities and oversees the Agency for Toxic Substances and Disease Registry; the Indian Health Service, which provides services to America’s Native Indian and Alaskan populations; Health Resources and Services Administration, which extends healthcare services to low-income, uninsured, or geographically isolated populations; Substance Abuse and Mental Health Services Administration, which works with states to provide treatment and counseling for the target population; and the Agency for Healthcare Research and Quality, which conducts research on U.S. healthcare systems, the quality and costs of healthcare, access to healthcare, and the effectiveness of medical treatments. Other programs that come under the HHS umbrella include the Centers for Medicare and Medicaid Services, which also bears responsibility for the State Children’s Health Insurance Program (SCHIP); the Administration for Children and Families, which administers the welfare and Temporary Assistance for Needy Families programs; the Administration on Aging, which provides essential senior services such as home-delivered meals and transportation; and the U. S. Public Health Service Commissioned Corps, which consists of some 6,000 health professionals under the leadership of the Surgeon General. HHS departments include the Office of Public Health and Science, the Office of the HHS Inspector General, and the HHS Office for Civil Rights. HHS national headquarters is located in the Hubert H. Humphrey Building at 200 Independence Avenue, SW, Washington, D.C. 20201. A number of other HHS agencies are headquartered at various locations around the capital. In addition to the Washington offices, HHS maintains facilities for the National Institutes of Health in Bethesda, Maryland, and several thousand employees are employed by various HHS agencies located in the Parklawn Building in Rockville, Maryland. The Centers for Disease Control and Prevention and the Agency for Toxic Substances and Disease Registry are housed in Atlanta, Georgia. HHS has established a number of major goals. These priorities include providing consumers with
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Depression Bibliography. Russell L. Ackoff and Sheldon Rovin, Re-
designing Society (Stanford University Press, 2003); Pascale Carayon, Handbook of Human Factors and Ergonomics in Health Care and Patient Safety (Lawrence Erlbaum, 2007); Department of Health and Human Services, http://www. hhs.gov/; Jerry V. Diller, Cultural Diversity: A Primer for the Human Services (Thomson Brooks/Cole, 2007); “Editorial: Family Planning Farce,” New York Times Online (November 24, 2006); Sar A. Levitan, et al., Programs in Aid of the Poor (Johns Hopkins University Press, 2003); Kenneth J. Meier and Laurence J. O’Toole Jr., Bureaucracy in a Democratic State: A Government Perspective (Johns Hopkins University Press, 2006); Dennis D. Riley, et al., Bureaucracy and the Policy Process: Keeping the Promises (Rowman & Littlefield, 2006); Gregory L. Weiss, Grassroots Medicine: The Story of America’s Free Clinics (Rowman & Littlefield, 2006). The United States Department of Health and Human Services is the umbrella organization for agencies that deliver social services.
the tools that allow them to make informed healthcare decisions; protecting healthcare records while providing patients and medical personnel with easy access to accurate healthcare information; facilitating prescription drug coverage for elderly Americans; providing assistance in revitalizing the New Orleans health system in the aftermath of Hurricane Katrina; personalizing healthcare in the United States; establishing prevention as a major factor in promoting public health; enhancing pandemic preparedness; and instituting emergency response and commissioned corps renewal. Despite the HHS pledge to deliver quality health and human services to all Americans, critics of the George W. Bush administration have expressed grave concern over HHS’s ability to serve the interests of women since the recent appointment of antiabortionist Dr. Eric Keroack to head family planning programs at HHS. Keroack is opposed to birth control, and his views on reproductive health are far from mainstream. This controversial appointment gave Keroack responsibility for financial decisions concerning the provision of healthcare to poor women in the areas of birth control, pregnancy tests, and breast care screening. See Also: Centers for Disease Control and Prevention
(CDC); National Institute of Health (NIH).
Elizabeth R. Purdy, Ph.D. Independent Scholar
Depression Depression is the general name for a set of diseases within the group of the mood disorders with different levels of impact. They include major depression disorder or episode, dysthymia, drug-induced depression, depression induced by a general medical condition, and depressive disorder not otherwise specified. Depressive disorders affect millions of people worldwide and major depression, the most serious of them, can be extremely incapacitating for daily activities or even lead to suicide. Depression is currently the first cause of disability in North America and it may become the second leading cause of disability worldwide by 2020. Depressive disorders affect people in all age groups. Depressive disorders are characterized by sadness or anhedonia, a severe loss of interest or pleasures in usual activities, as well as the presence of other symptoms. Diagnosis is made based on medical history, because there are no specific tests for these disorders. While prognosis and treatment vary from disorder to disorder, options may include drug therapy, psychotherapy, and electroconvulsive therapy for some cases. Combinations of these are often used. It is important to clarify that depression as used in common language to describe low mood or sad-
ness that arises from disappointments or losses do not fit a medical diagnosis and better terms to describe such feelings are either sadness or demoralization. Bereavement may cause all symptoms of a major depressive disorder, but this is considered a normal, self-limited situation unless it is sustained for more than two months after the loss. History Depressive disorders have called attention of people since ancient times. The papyrus of Ebers contains perhaps one of the earliest descriptions of clinical depression and the symptoms leading to the suicide of the Greek hero Ajax, described in Homer’s Iliad, is such a good depiction of a depressive disorder that it must have been based on real observations. Depression may also trace its roots to melancholia, a term used in ancient medicine to describe a predominance of black bile, one of the “four humors” postulated by Galen. The theory of the four humors postulated that there was need for equilibrium between those humors in the human body, and the excess of one of them would cause disease. When the black bile (melancholia in Greek) predominated, symptoms compatible with modern depression disorders arose. It is interesting to note that the modern theory of depressive disorders somehow resembles the idea of unbalanced humors: depression started to be explained by observations in the 1950s that drug-induced changes on neurotransmitter levels affected depressive symptoms, prompting the conclusion that depression was caused by an imbalance in the levels of neurotransmitters, still considered the pathophysiological basis of depressive disorders. Prevalence About 16 percent of the world population is affected by a form of depression on at least one occasion in their lives and the mean age of onset is in the late 20s. Some countries report a considerably higher incidence of depression, such as Australia, where the incidence of depression in women can reach 25 percent. Women appear to be at a higher risk for depression, but this is decreasing and there seems to be no gender difference in the elderly. One important point is that there may be an underestimation of the incidence of depression in men; due to cultural factors, men are less likely to complain of depressive symptoms and even less likely to seek and accept treatment for depression.
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Etiology Apart from depression induced by drugs or a general medical condition, the etiology of depression is unknown. Depression is more common in first-degree relatives of depressed patients than in the general population, and concordance between twins is high, which suggests a role of genetics. A genetic tendency for depressive disorders may be triggered, though, by deep or prolonged stress. Major life-stressing episodes, such as separations and losses, may cause depressive disorders but long-lasting, multi-episode depression seem to arise only in predisposed subjects. Neurotransmitters, which are substances produced by the neurons and used to transmit information between them, are also implicated in the etiology of depression. The production of different neurotransmitters has been found to be either diminished or abnormally regulated during depressive disorders. These include acetylcholine (involved in many cognitive functions such as learning and memory), norepinephrine and dopamine (involved mainly in motivation), and serotonin (related to the feelings of pleasure and satisfaction). Different neurotransmitters may have different levels of compromise, which may explain the diversity in the clinical manifestations of depressive disorders. Symptoms Symptoms of depression are classified by the Diagnostic and Statistical Manual of Mental Disorders, 4th edition (DSM-IV) in major and minor symptoms according to their specificity for depressive disorders. The major symptoms of depression are depressive mood or sadness and anhedonia, and a loss of interest or pleasure in usual activities. The minor symptoms can be divided in psychological or physical. Psychological minor symptoms are feelings of worthlessness or inappropriate guilt, reduced ability to concentrate or make decisions, recurrent thoughts of death or suicide (thinking, planning, or attempting). The physical minor symptoms are sleep disorders (insomnia or hypersomnia), changes in weight or appetite, loss of energy, fatigue and psychomotor agitation, or retardation. Anxiety is also commonly observed but it is not considered as a depressive symptom for diagnostic purposes. The severity of depression varies between patients and may be estimated by the number of presenting symptoms, their intensity as perceived by the patient or the physician, and the presence or absence
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of suicidal symptoms. Since depressive disorders can present with varied symptoms ranging from severe to mild, the diagnosis is sometimes difficult. A depressed patient may also present to the health professional with a great variation in his or her aspect, varying from apparently normal subjects to persons with a miserable aspect, with tearful eyes and poor facial expression, low voice and poor interaction with the interviewer, wearing carelessly, and assuming a curved posture. Psychotic symptoms may arise in some cases of depression, a situation which is more common late in life than in younger patients; nevertheless, psychotic symptoms are similar among elderly and young patients. Psychotic symptoms may include guilt about past actions and thoughts, delusions of illness, or even auditive hallucinations. Types of Depression and Diagnosis All depressive disorders are diagnosed based on history and symptoms. Major depression is the most severe form of depression and the one which may present great risk of suicide. It is characterized by the recurrence of major depressive episodes. A major depressive episode is characterized by at least one of the major symptoms and a total of at least five symptoms, for at least two weeks and in the absence of a general medical condition or drug that may explain the symptoms or a maniac episode. This last condition would prompt a diagnosis of a bipolar disorder, which is considered a separate clinical entity. The symptoms also cannot be explained by bereavement, in which case they have to be prolonged for more than two months to be considered a major depressive episode. Dysthymic disorder is characterized by chronic depression but less severe than a major depression. A patient has dysthymia when reporting depressed mood or appearing depressed to others for most of the day on the majority of days for two years or more. Sleep or appetite alterations, low self-esteem, and low energy are other common symptoms. Being a less severe form of depression, dysthymia may be undiagnosed for quite a long time, causing loss of life quality without impairing functioning with intensity enough for an obvious suspicion. A minor depressive episode does not fit the five symptoms of the major depressive episode nor does
it fit the duration of at least two years to be characterized as dysthymia. Thus, a patient is said to have a minor depressive episode if conditions for a major depressive disorder are present but the symptoms number from two to four symptoms including one major symptom. Currently the official diagnostic criteria of DSM-IV do not include minor depression and this set of symptoms would be characterized as a depression not otherwise specified. Treatment There are three main types of therapy for depressive disorders: antidepressant drugs, psychotherapy, and electroconvulsive therapy. Drug treatment Antidepressant drugs act by enhancing the levels of one or more neurotransmitters and the choice of the correct antidepressant involves the recognition of the different profiles depression can assume as well as the patient profile: Elderly people may not tolerate older antidepressants’ collateral effects and many drugs used to treat chronic conditions may not be used together with a given antidepressant. Several antidepressant drugs are currently available and they are divided into different classes according with the mechanism of action. Because these variations in the action of the antidepressants often reflect on potency, different neurotransmitter activation, and side effects, the choice of an antidepressant drug may be critical to the treatment of a depressive patient. The main classes of antidepressants are monoamine oxidase inhibitors, tricyclic antidepressants, selective serotonin reuptake inhibitors, dopamine reuptake inhibitors, norepinephrine reuptake inhibitors, tetracyclic antidepressants, and novel, atypic antidepressants. Psychotherapy Psychotherapy, conducted by trained mental health professionals (psychiatrists, psychologists, or psychiatric nurses), emphasizes the need for understanding and correcting situations, habits, or problems contributing to depression. Psychotherapy offers individuals or group approaches and, by resolving factors contributing to the depressive disorder, it may achieve either the effective treatment of depression or enhance the effectiveness of other treatment strategy. Psychotherapy and drug therapy are usu-
ally coadjuvant and the simultaneous use of both is a common treatment strategy. Successful psychotherapy may lead to a different pattern of habitual thinking, which may result in a lower relapse rate than is achievable with drug-exclusive therapy; this, however, may produce quicker results. In a crisis situation, drug therapy is usually the choice. From the many different psychotherapeutical approaches, cognitive behavior therapy has been demonstrated to be one of the most efficient in the treatment of depressive disorders. The base of this strategy is to work on how patients think about themselves and how they behave in their relationships. The main focus is to help depressed patients to identify and substitute negative thoughts with more realistic ones and develop stronger coping strategies. It can also be used to help patients with interpersonal skills, which may allow the experience of interpersonal communication and relationship with the least possible stress. Electroconvulsive Therapy Electroconvulsive therapy (ECT), also known as electroshock therapy or, simply, electroshock, uses short bursts of an electrical current in the brain in order to elicit a brief seizure while the patient is under general anesthesia. Most countries nowadays only allow ����������� electroconvulsive therapy�������������������������������������� to be conducted under anesthesia, in contrast to the direct electroconvulsive therapy of the past. Usually, the patient receives frequent treatment sessions per week for about one month and then the need for repeated sessions is evaluated. ECT may elicit side effects such as disorientation, headache, and short-term memory loss. ECT offers a very fast response when compared to psychotherapy and drug therapy, but this response decays if there is no maintenance treatment with either electroconvulsive therapy������������������������ or with a drug. Due to its fast action, ���������������������������������������� electroconvulsive therapy��������������� is considered to be the treatment of choice in emergency situations (e.g., suicidal behavior or in catatonic depression with cessation of oral intake). Antidepressant drugs may be associated from the beginning of ������������������� ECT���������������� so as to allow early discontinuation of it after drug therapy achieves control of the symptoms. ECT has assumed a bad reputation in popular culture worldwide, but it is still considered a good treatment option if well indicated, that is, where other
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treatment options have failed, in severely depressed patients (especially those who have a story of previous response to ECT), in patients with significant psychotic symptoms or where antidepressants cannot be used for any reason. It is, therefore, considered to be a therapy of exception. Suicidal Behavior Suicide is the most severe consequence of depression and overwhelming suicidal thoughts are considered a medical emergency. Medical professionals advise that people who express plans of suicide seek medical attention immediately. This is especially true when the means to undertake the plans were already made available (e.g., drugs, weapons, or other means). Having a suicide plan detailed is also a great risk for suicide. Treatments for a suicidal depressed patient may include reclusion, surveillance, or sedation with drugs until the effects of antidepressants are evident and suicidal thought vanishes. It is important to notice that most suicidal patients may inform the health professional once asked about suicidal intentions, although they will probably not inform that spontaneously. Therefore, it is important that health professionals actively search for risk of suicide in every depressed patient. Depression in the Elderly There are some special characteristics that make depression in the elderly a specific subject of study. As in other diseases in the elderly, differences in the aged organism may make depressive disorders difficult to diagnose. There is a smaller chance of finding depressed mood (sadness) in an elderly depressed subject as compared to anhedonia, leading to difficulty in suspecting the diagnosis. Within the minor symptoms, physical symptoms tend to be more common than psychological symptoms. Loss of functional status is often observed, especially in the frailest elders. Cognition, especially memory, can be so severely impaired that sometimes it mimics the clinical patterns of dementia; because in these cases the cause of cognitive loss is depression and that effect is potentially reversible, such condition is called pseudodementia. Another important feature of depression in the elderly relates to decompensation of previously compensated comorbidities: the loss of functional status
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may be so important that the person may lose ability or will to keep treatment for chronic conditions and it is not uncommon for the sudden worsening of a chronic condition to prompt the diagnosis of depression during emergency care. Suicidal behavior in major depression may be less frequent than in younger patients; nevertheless, studies have suggested that elderly people commit less theatrical attempts than younger patients and frailty may make elderly people more prone to die from an attempt that would not kill a younger person. These features make suspicion of suicide very important when dealing with older depressed patients. Depression in Children Depression in children can be very challenging, because the clinical presentation may be blunted by different, nonspecific symptoms. A depressed child might present with learning or memory problems not previously existing, sleep problems and nightmares, irritability, loss of appetite, and important behavioral changes. Rarely do these symptoms prompt parents to seek medical help; therefore, health professionals should suspect depression when evaluating children with such symptoms.
The Role of Anxiety in Depression Although anxiety and depression may occur at the same time (independently occurring together), both can occur together, with mood congruence and overlapping symptoms, a presentation that makes it difficult to separate the depression and the anxiety. This is especially true for elderly depressive patients, and “anxious depression” is a colloquial term well understood among clinicians. Seasonal Affective Disorder Seasonal affective disorder is a kind of depressive disorder that occurs in wintertime during short daylight periods. The production of melatonin, which occurs mainly in the dark, may be abnormally stimulated by the changes in the length of daylight period and this may be in the center of seasonal affective disorder’s pathophysiology. That is believed to be the reason why many patients with this condition benefit from phototherapy, the controlled exposure of the patient to bright, artificial light. Conclusion Depressive disorders are a relatively common set of diseases and the most severe form, major depression, can be very disabling. Occurring in all age groups, depression imposes a great burden on children, who often lack the diagnosis for a long time, and on elderly people, for whom the diagnosis may be difficult and the consequences of the disease may be severely incapacitating, notably in the frail elderly with different comorbidities. The most dreaded consequence of depression, which is suicide, on the other hand, can occur in all age groups. Early recognition and appropriate treatment of depressed people can be pivotal in these people’s lives. SEE ALSO: Geriatrics; Mental Health; Psychology. Bibliography. American Psychiatric Association, Diag-
Women appear to be at a higher risk for depression, but this is decreasing and there seems to be no gender difference in the elderly.
nostic and Statistical Manual of Mental Disorders, 4th ed. (text revision) (�������������������������������������������� American Psychiatric Association, 2000); R. C. Bland, �������������������������������������������������������� “Epidemiology of Affective Disorders: A Review,” Canadian Journal of Psychiatry (v.42, 1997); Edmund H. Duthie, et al., Practice of Geriatrics, 3rd ed. (Saunders, 1998);�������������������������������������������������� John R. Geddes, et al., “Relapse Prevention with Antidepressant Drug Treatment in Depressive Disorders: A Systematic Review,” Lancet (v.361, 2003); C. J. L. Mur-
ray and A. D. Lopez, “Alternative Projections of Mortality and Disability by Cause 1990–2020: Global Burden of Disease Study,” Lancet (v.349, 1997); J. C. Nelson, “Managing Treatment-Resistant Major Depression,” Journal of Clinical Psychiatry (v.64 Suppl, 2003); A. R. Tyrka, et al., “Psychotic Major Depression: A Benefit-Risk Assessment of Treatment Options,” Drug Safety (v.29/6, 2006); C. F. Reynolds III, “Treatment of Major Depression in Later Life: A Life Cycle Perspective,” Psychiatric Quarterly (v.68, 1997); J. J. Schildkraut, “The Catecholamine Hypothesis of Affective Disorders: A Review of Supporting Evidence,” American Journal of Psychiatry (v.122/5, 1965). Thiago Monaco, M.D., Ph.D. University of São Paulo Medical School, Brazil
Dermatitis Dermatitis is a general term used to describe the features of several skin conditions linked by the clinical finding of inflammation in the epidermis (top layer of the skin). In general it may be thought of as the skin’s response to stress or irritants in the environment, and it is not contagious. There are many different types of dermatitis, which are clinically characterized by the presence of redness, scaling, pruritus (itching), swelling, and in severe cases blistering. Each type of dermatitis has an underlying pathophysiologic mechanism, which directs the appropriate therapy. Family practitioners, internists, allergists and dermatologists (a doctor who specializes in skin diseases), commonly diagnose cases of dermatitis based on the appearance and symptoms. In the event that the dermatitis is caused by an environmental allergen, prick testing with dermal needles (by an allergist) or patch testing with epicutaneous (upon the skin) chemicals applied with stickers on the skin may be necessary to determine the causative agents. Epidemiology Dermatitis occurs in people of all ages and ethnicities. According to the National Institutes of Health, people who live in dry climates or in cities have a higher risk of developing atopic dermatitis. Approximately 20 percent of children suffer from some form of dermatitis, and some of them continue to have this condition as adults.
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Atopic Dermatitis Atopic dermatitis, often referred to as eczema, has a high prevalence in children, but may occur at any age. It is caused by a combination of genetic and environmental factors, and is often linked with allergies, asthma, and stress. The clinical appearance of atopic dermatitis may vary by the individual; however, the hallmark clinical picture is acute eruptions of erythematous (red), scaled, and pruritic (itching) plaques involving the antecubital fossa (inner arm crease) and popliteal fossa (behind the knee crease). The condition waxes and wanes and may have periods where the skin appears normal. Atopic dermatitis is usually controlled by identifying and avoiding triggers and maintaining the skin barrier with emollient moisturizers. In moderate to severe cases it may be necessary to treat the affected area with topical steroids or immunomodulators, and systemic antihistamines. Contact Dermatitis Contact dermatitis is the skin’s innate inflammatory reaction to an offending external environmental chemical trigger. There are three main subcategories of contact dermatitis: urticarial, irritant, and allergic. On the other hand, with contact urticaria, the least common, hives develop by an IgE-mediated immediate type mechanism to chemical triggers such as environmental allergens or certain foods. The classical clinical presentation is characterized by a local tingling sensation and localized redness and swelling. It is usually treated with topical anti-itch creams, oral antihistamines. In moderate to severe cases systemic steroids may be necessary. As this is an immediate type reaction it may develop rapidly. A common example of contact urticaria is the allergic reaction to latex. In irritant contact dermatitis (ICD), the most common form, irritants penetrate the skin and in doing so may remove the protective oils and moisture from the skin’s outer layer. This results in chemical injury to the superficial layers of the skin with subsequent inflammation. The dermatitis in ICD usually appears within 48 hours of exposure to a caustic chemical and is generally limited to the areas of the skin which was in contact with the irritant. There may be variation in the clinical appearance depending on the strength of the chemical trigger and the strength of the skin barrier to sustain the insult. ICD can be caused by soaps, detergents, and antiperspirant, among others.
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Allergic contact dermatitis (ACD) arises when an immune response is triggered in the skin after repeated contact with allergenic substances (such as fragrances and formaldehyde). The ACD-type dermatitis may be confined to the area of the skin that contacts the allergen; however, distant sites of previous exposure may also re-react with repeated exposures. The best form of treatment for contact dermatitis is to avoid the substance that causes the inflammatory reaction. It might be difficult to determine the exact component of the substance that is causing the reaction. In ACD, patch tests may need to be performed. Seborrhoeic Dermatitis Seborrhoeic dermatitis mostly occurs in the hairbearing and oily areas of the skin, such as the face, scalp, genital area, and trunk. This form of dermatitis is believed to be an inflammatory reaction to a combination of the Malassezia yeast, a normal inhabitant of the skin, and decreased keratolysis (dead cells being removed) of the skin. Seborrhoeic dermatitis usually appears as dry, pink patches with waxy scale. It can be treated with the use sulfa/sulfacetamide washes and lotions, selenium, and zinc-based lotions and shampoos, topical antifungal/yeast agents (such as the azoles), and topical steroids. Neurodermatitis Neurodermatitis is a skin condition that is characterized by tremendous pruritus and subsequent excoriation. As is seen with all chronic dermatoses, the skin may increase in thickness and become rough (lichenified) in the affected area. Physicians may use patch testing, skin biopsies, or blood tests to accurately diagnose the condition, and a neurologic cause must be ruled out. Antipruritus medications such as emollients, topical steroids, and antihistamines may be needed. Prevention For prone individuals, lifestyle changes which maintain the skin barrier and include the avoidance of known triggers are paramount to the reduction of flare-ups and alleviation of symptoms. SEE ALSO: Skin Diseases (General). BIBLIOGRAPHY. DermNet NZ, “Dermatitis” www. derm-
netnz.org (November 2005); James C. Shaw, “Overview of
Dermatitis,” UpToDate (2006); National Institute of Arthritis and Musculoskeletal and Skin Diseases, “Handout on Health: Atopic Dermatitis,” www.niams.nih.gov (April 2003). Shalu S. Patel University of Michigan Rajiv I. Nijhawan JoAnn Tijn Kon Kiem Independent Scholars
Developmental Disabilities Developmental disabilities are a global health matter, affecting individuals from childhood through adulthood, presenting various special issues for families, educational, and healthcare systems throughout the world. A developmental disability, as defined by the U.S. government in Public Law 95-602, is a chronic mental and/or physical impairment, which manifests before age 22. Developmental disabilities are characterized by significant functional limitations in three or more of the following areas of major life activities: 1) self-care, 2) receptive and expressive language, 3) learning, 4) mobility, 5) self-direction, 6) capacity for independent living, and 7) economic self-sufficiency. These problems are diagnosed by comparing a child’s performance with the performance norms of the child’s same-age peers. As developmental disabilities are chronic, usually affecting multiple body parts or systems, and are likely to be lifelong, they often necessitate individualized multidisciplinary care. Developmental disabilities are sometimes referred to as developmental delays or disorders. Types of Developmental Disabilities Developmental disabilities can be categorized into nervous system disabilities, sensory-related disabilities, metabolic disorders, and degenerative disorders. Nervous system disabilities refer to primary impairments of the brain and/or spinal cord, thereby impacting multiple aspects of learning and intelligence. The most common result of a nervous system disability is mental retardation (or low intelligent quotient [IQ]), which is a hallmark characteristic of many developmental disabilities. The most common nervous system disabilities include Down syndrome, Fragile X
syndrome, and autism spectrum disorders. Autism, for example, is characterized by impairments in social interaction, communication, and restricted repetitive patterns of behavior, interests, or activities. Sensory-related disabilities refer primarily to impairments in visual and auditory processing. They occur, not only as a primary symptom (such as deafness), but are also common comorbid problems with other developmental disabilities. Metabolic disorders are often caused by genetic deficiencies in an enzyme, thereby affecting a person’s ability to synthesize and break down substances in the body. For example, phenylketonuria (PKU) is caused by a deficiency of a certain enzyme, creating a toxic level of one amino acid and too little of another, resulting in brain damage and severe mental retardation. Degenerative disorders refer to disabilities that are not apparent at birth but that manifest at an older age, causing the child who was developing normally to lose previously acquired skills. Functioning may regress or be lost in physical, mental, and/or sensory modalities. An example of a degenerative disorder is Rett syndrome, where persistent and progressive degeneration throughout life occurs in five areas: head circumference, hand movements, social engagement, gait, and language development. Incidence Approximately 17 percent of children under the age of 18 have some type of developmental disability, including more mild conditions such as speech and language disorders and learning disabilities. About 2 percent of children under the age of 18 have a more serious developmental disability including mental retardation, autism, cerebral palsy, hearing loss, and vision impairment. Of these serious developmental disabilities, mental retardation is the most common. Causes The exact cause of many developmental disabilities is unknown. Some factors that contribute to developmental disabilities include trauma or infection to the brain, prenatal nutrition problems, prenatal drug or alcohol exposure, extreme premature birth, genetic and chromosomal abnormalities, and poor nutrition and medical care. Some disabilities are believed to be caused by an interaction of these biological and environmental factors.
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Associated Problems Children with developmental disabilities have been shown to have poorer health, including increased rate of injury and need for medical attention. They also do not perform as well in school as their peers. Children with developmental disabilities have increased social problems including poor peer relationships, and increased risks of delinquency and substance abuse. They are also at increased risk for child abuse. Assessment Evaluation of developmental disabilities is best accomplished by a multidisciplinary team that includes the child’s pediatrician, teachers, a psychologist, a speech and language therapist, an occupational therapist, and an educational specialist. Evaluations should include standardized tests of intellectual ability (e.g., the Bayley Scales of Infant Development, the Stanford-Binet Intelligence Scale, and the Wechsler Intelligence Scales), behavioral assessments (e.g., Vineland Adaptive Behavior Scale), clinical testing of speech and language, academic testing, physical and neurological examinations, and a detailed medical and developmental history. Test results are compared to norms for same-age peers to determine relative discrepancies. The Diagnostic and Statistical Manual of Mental Disorders, 4th edition, text revision (DSMIV-TR) is also used for making diagnoses. Early Identification and Screening While a developmental disability may keep a child from developing normally and reaching cognitive, behavioral, or physical milestones, specialized intensive intervention can help improve the prognosis. The key to treatment success is early intervention. Thus, early identification is crucial. Birth to 3 years of age is a critical time in a child’s development, and identification and treatment during this time can improve a child’s functioning, prevent associated problems, and ease the burden for the family. Proper treatment can also improve quality of life for the child and enable him or her to lead a more independent life as an adult. Screening tools identify children who may have a developmental disability and, thus, warrant further assessment and possible treatment services. By conducting screenings early, a child may begin to receive treatment during a time when he or she is still developing and, therefore, most responsive to intervention.
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Family physicians and pediatricians are in a unique position to identify children with developmental disabilities. Unfortunately, however, many fail to identify them early enough for families to provide early intervention services. The American Academy of Pediatrics recommends that primary pediatric healthcare providers use standard screening tools to conduct developmental screening of infants and children every year during the first three years of life. Treatment While there is no cure for many of the developmental disabilities, treatments are available to address a range of symptoms. For example, for autism, a multidisciplinary approach of behavioral, occupational, and speech and language therapy can help a child to use language, decrease harmful behaviors, and aid in selfcare. Educational resource specialists can provide support in the school environment to facilitate the child’s functioning in the regular classroom. Many research studies have shown the importance of teaching treatment techniques to parents and teachers. Skills taught to parents and teachers include feeding techniques, eye gaze, sign language, child management skills, positioning, gross motor skills, and communication skills. Medications also play an important role in treating the symptoms associated with developmental disabilities. Early Intervention Research has shown that early intervention has a positive effect for many disabilities and substantial benefits for certain disorders. For example, children who are identified as having autism early in life have been shown to have significantly better cognitive, language, and motor skills and complete a higher level of education than their peers who were identified later in life. Early intervention can also improve a child’s self-esteem thereby keeping him or her from a trajectory that may include substance abuse, interpersonal problems, or delinquency. Educational Services For school-age children, U.S. law mandates that an evaluation called an Individualized Education Program (IEP) be conducted which documents the child’s developmental level, the types of support that he or she needs to succeed, and goals for establishing independence. Parents, teachers, and school psychologists
are often present at IEP meetings to ensure that there is a comprehensive approach in meeting children’s needs. For younger children, a similar evaluation called the Individualized Family Support Plan (IFSP) is conducted to establish early intervention services. It is critical that the educational program of a child with a developmental disability is at the appropriate level for him or her. For children who attend school, a range of options are available. Some children will require a separate special education classroom for their needs to be met. This is no longer the only choice available, however, as it has been in the past. Children with disabilities may now also participate fully in the regular classroom, due to a movement called “mainstreaming.” Sometimes, they may have a resource specialist with them in the classroom to provide individualized support. Experts agree that the child should be placed in the least restrictive school environment possible. Postsecondary education and vocational training is also increasingly available for people with disabilities, and legislation in some areas mandates that accommodations be made for students with disabilities. Daily Living For adults, the scenarios in which people live and work lie on a spectrum. There was a time when people with disabilities lived segregated from the general population in institutions. Legislation and alternative support systems have made this situation less common. Many adults with developmental disabilities live by themselves, with family, or with roommates. Such individuals may have an aide who comes to the house or apartment to help with tasks of daily living on a regular basis, or who lives with them. Other people with developmental disabilities live in group homes with individuals with similar needs, where professional assistance is provided 24 hours a day. Day programs are also available, which provide a range of services from skills training, to social activities and outings, to educational programming. Support systems for people with developmental disabilities are often based on the premise of helping them to attain the greatest level of independence possible so that they can maintain quality of life and make positive contributions to society. SEE ALSO: Attention Deficit Disorder; Autism; Birth De-
fects; Blindness; Child Development; Child Mental Health;
Diabetes
Deafness; Down Syndrome; Genetic Disorders; Infant and Toddler Development; Mental Retardation; Metabolic Disorders; Premature Babies; Rett Syndrome; Spina Bifida. Bibliography. M. D. Batshaw, L. Pellegrino, and N. J.
Roizen, Children with Disabilities (Paul H. Brookes, 2007); S. I. Greenspan and S. Wieder, The Child with Special Needs: Encouraging Intellectual and Emotional Growth (Perseus Books, 1998); F. R. Volkmar, et al., Handbook of Autism and Pervasive Developmental Disorders (Wiley, 2005). Doniel Drazin, M.A. Albany Medical College
Diabetes The developed and developing worlds are witnessing an epidemic of type 2 diabetes mellitus (T2DM), associated with a concomitant rise in the rates of obesity. Diabetes mellitus (DM) is the sixth leading cause of death in the United States, and its adverse health consequences, including heart disease, blindness, limb amputation, and kidney disease, represent a tremendous burden to healthcare systems. Greater than 7 percent of Americans have diagnosed DM, but the disease and its complications account for almost 14 percent of American healthcare expenditures. Moreover, the American Diabetes Association (ADA) estimated that the direct and indirect expenditures of DM, including medical costs, lost workdays, disabilities, and deaths, totaled $132 billion in the United States in 2002. Glucose Metabolism DM is caused by an inability of the pancreas to produce the hormone insulin in a sufficient quantity to meet the body’s demands. The pancreas is an exocrine and endocrine organ located behind the stomach in the abdomen. It secretes certain important digestive enzymes into the small intestine to break down food (exocrine function), but it also secretes hormones such as insulin, glucagon, and somatostatin into the bloodstream to regulate the body’s nutrient use (endocrine function). The β-cells of the pancreas secrete insulin in response to eating. This hormone acts at receptors in the liver, muscles, and other organs to allow their uptake of glucose, the
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simple sugar carbohydrate that is the body’s primary energy source. The tissues of the body use the energy from glucose to perform their normal physiologic functions. If there is an excess of glucose, the liver and muscles can store it for later use as glycogen, a more complex carbohydrate consisting of chains of glucose. Insulin also allows the body to turn free fatty acids (FFA) into triglycerides, the main component of adipose (fat) tissue. Without insulin, the body cannot use the glucose in the bloodstream, despite its abundance after a meal. To compensate, tissues break down protein and fats for energy, a situation similar to starvation. DM results either when the pancreas does not produce enough insulin or when the body becomes resistant to the effects of insulin. Regardless, the common outcome is hyperglycemia (elevated blood glucose levels) and a paradoxical inability of the body’s tissues to use this glucose. Definition of DM The term diabetes most commonly refers to the endocrine disorders of carbohydrate metabolism known as diabetes mellitus (DM), conditions characterized by hyperglycemia. Originating from the Greek for “one that straddles” or “a siphon,” the word diabetes alone, however, also encompasses a number of metabolic disturbances that result in increased urine production, including DM and diabetes insipidus (DI). Unlike DM, DI is a condition of increased urine output that is not caused by increased glucose levels. It is categorized by etiology. Nephrogenic diabetes insipidus (NDI) is due to an inability of the kidney to concentrate urine and can be caused by a genetic mutation or by treatment with the mood stabilizer lithium. Central diabetes insipidus (CDI) is generally caused by an inability of the central nervous system to detect and regulate the electrolyte concentration of the body’s fluids; it can be caused by head trauma and some cancers. DI represents a distinct pathophysiologic process from DM and is not associated with the numerous complications of the latter. Two laboratory tests are used to define and diagnose DM: fasting plasma glucose (FPG) and the twohour oral glucose tolerance test (OGTT). The FPG is obtained by measuring the glucose level in the blood after a fast of eight to 12 hours. Even in nondiabetics, plasma glucose levels are elevated after eating, but high glucose levels after fasting indicate a problem
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with glucose metabolism consistent with diabetes. The ADA and the World Health Organization (WHO) define DM by an FPG≥126 mg/dL (7.0 mmol/L). FPG values between 100 and 125 mg/dL (5.6–6.9 mmol/L) define impaired fasting glucose (IFG), a “prediabetic” condition associated with future risk of progression to DM. The OGTT is a different measure of glucose metabolism; during this test, the participant drinks a 75-gram glucose solution and has his blood drawn two hours later. Normal individuals will be able to metabolize this glucose and reduce their plasma glucose to below 140 mg/dL (7.8 mmol/L) within two hours. DM is diagnosed at an OGTT≥200 mg/dL (11.1 mmol/L), while an OGTT between 140 and 200 mg/dL defines impaired glucose tolerance (IGT), another “prediabetic” state that has significant overlap with IFG. DM can be diagnosed with the FPG, the OGTT, or a random (nonfasting) plasma glucose >200 mg/dL in the presence of diabetic symptoms such an increased urination, thirst, blurred vision, or weight loss. Regardless, the diagnostic test should be repeated to confirm the diagnosis. Cases of DM that cannot be categorized as type 1 or type 2 (see below) may require antibody testing to identify the autoantibodies often found in type 1 DM (T1DM). In patients with certain risk factors associated with the development of T2DM, the FPG can be used as a screening test to detect the disease. Types and Epidemiology of DM While all forms of DM are marked by hyperglycemia and result from an absolute or relative insufficiency of insulin, there are distinct types of DM that differ in their etiology. In 1997, the ADA introduced the terms type 1 and type 2 diabetes mellitus to replace the previous terms insulin-dependent and non-insulin–dependent diabetes, respectively. Formerly known as insulin-dependent (IDDM) or juvenile onset diabetes, T1DM is an autoimmune disease in which the body’s own immune system destroys pancreatic β-cells, thereby eliminating the ability of the pancreas to produce insulin. T1DM affects less than 0.5 percent of the world population. Most cases occur in childhood or early adulthood, although it can occur at any age. Certain populations, including those in Scandinavia, are at greater risk for the disease than others, such as the Chinese. There is a genetic predisposition to T1DM, as evidenced by the
30-percent risk in identical twins of type 1 diabetics compared to the 0.4 percent risk in people with no family history of the disease. Some of the predisposing genetic mutations have been identified, although they are not sufficient to cause T1DM. Researchers have proposed several environmental triggers that may lead to T1DM in genetically predisposed individuals, including perinatal viral infections and exposure to certain foods like cow’s milk and cereals in infancy. Most researchers believe that some environmental exposure triggers an autoimmune response in such people, resulting in antibodies directed against molecules in the pancreas necessary for insulin release. These antibodies cause the body’s own immune system to destroy the pancreatic β-cells, eliminating the ability of the pancreas to secrete insulin within a few months to years. Type 1 diabetics must take insulin injections for survival. Screening for T1DM is not currently recommended for individuals at higher risk for the disease, such as children of type 1 diabetics. Associated with obesity, T2DM comprises the majority of the current diabetes epidemic. T2DM may account for up to 95 percent of DM cases in some populations. Initially in the disease process, T2DM is characterized by insulin resistance, not by decreased pancreatic insulin production. The body’s tissues, including the liver, muscles, and adipose tissue, become resistant to the effects of insulin and therefore take up less glucose from the bloodstream. To overcome this insulin resistance, the pancreas secretes greater amounts of insulin to maintain proper glucose balance. Eventually, the pancreas cannot maintain this elevated insulin secretion, and insulin production declines, resulting in hyperglycemia similar to T1DM. Greater than 8 percent of the U.S. population carries a diagnosis of T2DM, although the true prevalence is higher due to underdiagnosis. This percentage is increasing: The prevalence of T2DM increased 38 percent between 1976–80 and 1988–94 in U.S. adults. Formerly seen exclusively in adults, T2DM is also increasing in prevalence in children and adolescents as the obesity epidemic has begun to include these generations. Although rates of T2DM are currently higher in developed countries, its prevalence is increasing most rapidly in developing countries. Wild estimated that the global prevalence of all DM will increase 39 percent from 4.6 percent in 2000 to 6.4 percent in 2030. Indeed, India and China currently have the most diabetics.
Certain ethnic groups are at greater risk for T2DM, including African Americans, Latinos, Native Americans, Asian Americans, and Pacific Islanders. Although lifestyle and socioeconomic factors may explain some of these disparities, there is also a strong genetic component to T2DM that varies with ethnicity. Having a sibling with T2DM increases one’s own risk by 20 to 30 percent, and monozygotic (identical) twins have more similar risks for T2DM than dizygotic (fraternal) twins. Although rare types of DM due to single gene mutations exist, the genetic component of T2DM is likely due to mutations in several genes, each contributing a small part to the overall insulin resistance and pancreatic β-cell dysfunction. Despite the importance of one’s genetic make-up in determining one’s risk for T2DM, the recent increase in the incidence of this disease gives evidence for its environmental risk factors, including weight gain, physical activity, and diet. Thus, the current paradigm for the etiology of T2DM is that certain individuals, including members of at-risk ethnic groups, have a genetic predisposition to T2DM, making them more likely to manifest the disease if they have additional environmental risk factors like physical inactivity or increased caloric intake. Some of this increased risk is mediated by a predisposition in some people to gain weight more easily than others, resulting in the insulin resistance associated with increased adiposity. The risk of T2DM increases with increasing body mass index (BMI), even within the normal range <25 kg/m2. Other risk factors for the development of T2DM include an age of 45 years or older, a history of gestational DM, hypertension, and high cholesterol or triglycerides. Gestational diabetes exists when the physiologic stresses of pregnancy cause an underlying predisposition for DM to manifest. These women have a higher risk of developing nongestational DM later in life. Several hereditary forms of DM due to single mutations have been identified, the most common of which are the various maturity-onset diabetes of the young (MODY), which are disorders due to autosomal dominant inheritance of mutations in important genes in glucose metabolism. Only about 1 to 5 percent of cases of DM are from one of the several singlemutation types; the vast majority of cases are T2DM, whose hereditary component is likely a complex picture involving mutations in several genes.
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Other genetic conditions like Down syndrome and Huntington chorea are associated with an increased risk of DM. Diabetes can also be caused by diseases that damage the pancreas, including chronic pancreatitis from alcoholism and hemochromatosis, a condition marked by excess iron deposition in organs such as the pancreas. Traumatic injury to the pancreas, including any damage the pancreas may sustain during abdominal surgery, can also result in DM. Some medications can result in diabetes-like hyperglycemia, including thiazide diuretics and corticosteroids like prednisone. Natural History and Complications The classic symptoms of DM are due to hyperglycemia: increased thirst, increased consumption of liquids, and increased urination. Other symptoms include blurred vision and weight loss. Especially in the case of T1DM, some individuals are found to be diabetic when they go into diabetic ketoacidosis (DKA), a life-threatening condition in which the body’s inability to use glucose for energy results in the release of too much acid in the form of free fatty acids. People in DKA have abdominal pain, nausea, and vomiting and may progress to seizures or even coma without treatment, which includes insulin. Despite these possible early symptoms, many undiagnosed diabetics remain asymptomatic and may learn they have DM only because of routine medical blood tests. By this time, many of them already have one or more of the diabetic complications described below. The complications of DM are generally categorized as microvascular or macrovascular, affecting the small and large blood vessels of the body, respectively. The microvascular complications of DM include damage to the retinas, kidneys, and nerves, while macrovascular disease involves the vessels that oxygenate the heart, brain, and extremities, resulting in myocardial infarctions (heart attacks), cerebrovascular accidents (strokes), and limb amputations. T2DM has a more insidious onset than T1DM, and thus many type 2 diabetics already have microvascular complications like eye and kidney disease at the time their disease is diagnosed. Diabetic disease of the retinas (retinopathy) is often present at the time of diagnosis of T2DM (up to 30 percent of patients), whereas it is present in less than 3 percent of newly diagnosed type 1 diabetics. Almost all type 1 diabetics develop some retinopathy after having
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DM for 20 years, while this prevalence is 50 percent to 80 percent in type 2 diabetics. Diabetic retinopathy is the leading cause of blindness in adults 20–74 in developed countries. Its progression can be slowed with good glycemic control, as monitored with hemoglobin A1c levels, and by treating coexisting hypertension. Surgical procedures such as photocoagulation and vitrectomy may be required in more advanced cases. A second microvascular complication of DM is diabetic kidney disease (nephropathy), the leading cause of end-stage renal disease in the world. Diabetic nephropathy begins insidiously as microalbuminuria, a small amount of the protein albumin being leaked into the urine. The amount of this proteinuria increases with the progression of the kidney disease and is an indication of the amount of kidney function lost due to the scarring that DM causes in the kidneys. Once a large amount of proteinuria is present, the median time to end-stage renal disease is two and a half years, at which time kidney transplant or hemodialysis is necessary. Glycemic control and treatment with angiotensin converting enzyme (ACE) inhibitor medications can slow the progression of diabetic nephropathy. Diabetic microvascular disease also damages nerves (neuropathy), most commonly the sensory nerves in the lower extremities but also the autonomic nerves responsible for maintaining blood pressure when a person stands up from sitting. Diabetic peripheral neuropathy often results in decreased sensation in the feet, predisposing a patient to painless sores that can become infected. The macrovascular damage to the blood vessels in the legs (peripheral vascular disease [PVD]) decrease lower extremity circulation and slow the healing of such infections. The decreased oxygenation of the legs and the increased susceptibility to infections often necessitate leg amputations, ultimately required in 5 percent of diabetics. Again, good glycemic control, regular foot examinations, and surgeries that improve blood flow to the lower extremities can reduce the foot complications associated with DM. In addition to PVD, diabetic macrovascular disease also increases the risk of heart attack and stroke. Some studies estimate that DM increases the risk of these events by two to three times, even after adjusting for other known risk factors. Within diabetics, poorer glycemic control increases this risk even greater. Indeed, DM is considered to be a “risk equivalent” for coronary artery disease; that is, a dia-
betic is as likely to have a heart attack within 10 years as someone who has already had a heart attack. The World Health Organization (WHO) estimates that coronary heart disease (CHD) was the second leading cause of mortality worldwide in adults under 60 and by far the leading cause of mortality in those over 60 in 2002, followed by strokes. Given the significant risk of CHD conferred by DM, the prevention and treatment of this disease remains important to reduce its overall public health burden. Prevention and Treatment Since much of the pathogenesis of T1DM, including possible environmental triggers, remains unidentified, there are as yet no effective ways to prevent this type of DM. Given the magnitude of the public health impact of T2DM, however, its prevention is a topic of great interest. Despite the significant genetic predisposition to T2DM, some cases of the disease can be prevented through lifestyle modification. The Nurses’ Health Study in the United States showed that modifiable lifestyle factors associated with a lower incidence of T2DM include a BMI<25 kg/m2, moderate physical activity of at least 30 minutes per day, no smoking, and a diet high in fiber and polyunsaturated fat and low in trans fat and glycemic index. Randomized trials have shown that the risk of T2DM in those already at high risk for the disease can be reduced through weight loss and increased physical activity. Moderate calorie restriction such as a reduction of 250 to 500 calories per day improves insulin sensitivity and glycemic control. Increased physical activity, even independent of any reduction in body weight, also improves insulin sensitivity, while sedentary activities like television watching are associated with an increased risk of T2DM. The target of treatment for DM is glycemic control, or maintaining a diabetic’s blood glucose levels within a normal range. The importance of glycemic control in diabetics was demonstrated in the Diabetes Control and Complications Trial (DCCT), a landmark prospective randomized trial in type 1 diabetics that compared conventional insulin therapy with more intensive insulin therapy that used multiple daily injections or continuous insulin pump infusion. The more intensive therapy reduced glucose levels and delayed or slowed the progression of microvascular complications, including retinopathy and nephropathy.
The United Kingdom Prospective Diabetes Study (UKPDS) similarly demonstrated the importance of glycemic control for reducing microvascular complications in type 2 diabetics. There is less evidence to suggest that glycemic control reduces the risk of macrovascular complications like coronary artery disease, but the advantages for microvascular complications clearly make glycemic control an important therapeutic goal. Diabetics are encouraged to check their blood glucose at different times throughout the day (fasting and nonfasting) with home finger-stick glucometers and record these values in a log. If any of these values are too high or low, the patient and his physician can adjust his medication regimen accordingly. To get an overall idea of a patient’s glycemic control over the last three months, physicians will check a hemoglobin A1c (HbA1c) level, a form of hemoglobin attached to sugar. Hemoglobin is a protein in red blood cells that allows them to carry oxygen, and high glucose levels in the blood cause sugar to attach to it. Normally, HbA1c comprises less than 5 percent of an individual’s hemoglobin, but this percentage increases in diabetics. Diabetics should aim to keep their HbA1c levels below 7 percent, with dietary measures, physical activity, and medications. Lifestyle modification is an essential component of the treatment of DM. Even modest weight loss can improve a type 2 diabetic’s insulin sensitivity and improve HbA1c levels. This weight loss should be accomplished by reducing the total number of calories consumed daily with a diet rich in fruits, vegetables, whole grains, lean meats, and low-fat dairy products. Dietitians are key players in diabetic management, guiding patients to better food choices. Increased physical activity is also essential for weight loss and maintenance; the current recommendations from the National Institutes of Health call for 30 to 60 minutes per day of moderate intensity activity such as brisk walking. Maintaining adequate glycemic control with diet and exercise alone is rare in a diagnosed diabetic, and so medications are important adjuncts to lifestyle modification. Producing insufficient insulin to meet the body’s needs, type 1 diabetics require insulin injections or pumps, although inhaled insulin has recently been approved by the Food and Drug Administration (FDA). Different insulin preparations vary by how quickly they begin acting and for how long they act, and endocrinologists use a patient’s log of home finger-stick blood glucose levels to tailor a given pa-
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tient’s insulin regimen. While the goal is to avoid hyperglycemia, hypoglycemia (low blood sugar) is a risk of taking too much insulin. The symptoms of hypoglycemia include sweating, heart palpitations, and nausea, and if a hypoglycemic patient does not soon take in glucose either in the form of food or intravenous solution, he may progress to seizure or coma. In addition to type 1 diabetics, some type 2 diabetics may require insulin if oral medications do not provide adequate glycemic control. Generally, however, type 2 diabetics are initially begun on oral diabetic medications at the time of diagnosis. There are several classes of oral diabetic medications, including the sulfonylureas, the biguanides such as metformin, the thiazolidinediones, the α-glucosidase inhibitors, and the meglitinides. Each of these classes of medications acts at a different part of the glucose metabolism pathway, including insulin sensitivity and insulin secretion, but in general they can have approximately equal efficacy in glycemic control. Each also has its own different adverse effects, which may guide physicians to choose one medication over another for a given patient. Metformin is often the first-line agent for obese patients with T2DM, since it can cause a modest degree of weight loss. See Also: Diabetes and Pregnancy; Diabetes Type I (Ju-
venile Diabetes); Diabetes Type II.
Bibliography. K.M. Gillespie, “Type 1 Diabetes: Patho-
genesis and Prevention,” Canadian Medical Association Journal, (v.175/2, 2006); C. Mantzoros, ed., Obesity and Diabetes (Humana Press, 2006); S.M. Marshall and A. Flyvbjerg, “Prevention and Early Detection of Vascular Complications of Diabetes,” British Medical Journal (v.333/7566, 2006); S .Wild, et al., “Global Prevalence of Diabetes: Estimates for the Year 2000 and Projections for 2030,” Diabetes Care (v.27, 2004). Jason Vassy Washington University in St. Louis
Diabetes and Pregnancy There are two types of diabetes mellitus (DM) in pregnancy. First, women with types 1 and 2 DM before
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pregnancy (pregestational diabetes [PGDM]) are at increased risk for adverse obstetric outcomes such as miscarriage and congenital malformations. Second, women who are not diabetic before pregnancy may developed impaired glucose metabolism as a result of pregnancy (gestational diabetes [GDM]). GDM also carries an increased risk of adverse events, and although it resolves after delivery, it places the mother at an increased risk for future development of nonpregnant DM. About 4 percent of American pregnancies are complicated by DM, of which 88 percent are cases of GDM and 12 percent are in women with preexisting type 1 or 2 DM. The proportion of pregnancies with type 2 DM (T2DM) and thus PGDM is expected to rise as women delay pregnancy until later ages and as the incidence of T2DM increases with the increasing rates of obesity. Diabetic women who wish to conceive should first receive thorough physical examination, laboratory analyses, and counseling on the diabetic complications of pregnancy. Pregnancy should be avoided in women with significant coronary artery disease. PGDM causes obstetric complications for both the mother and the fetus. Reduced kidney function and high blood pressure increase the risk of preeclampsia, a life-threatening elevation of blood pressure. During the first trimester, pregnancies in women with PGDM are at higher risk of miscarriage and congenital malformations of the fetal nervous and cardiovascular nervous systems. Preeclampsia, miscarriage, and preterm birth (delivery before 37 weeks gestational age) are risks during the second and third trimesters. Many miscarriages may be due to low fetal oxygen levels (hypoxemia) resulting from the increased metabolic rate caused by the high insulin levels found in T2DM. Although worldwide reductions in perinatal mortality have been achieved in recent decades, diabetic pregnancies remain at a higher risk of perinatal mortality than other pregnancies. Because high maternal blood glucose levels are passed through the placenta to the fetus, PGDM is also associated with macrosomia, defined by a fetal weight greater than 4,000 grams (8.8 pounds). Pregnancies with macrosomia are more likely to be complicated by prolonged labor and shoulder dystocia of the infant at delivery, which may result in nerve damage to the shoulder and arm during difficult passage through the birth canal, especially with forceps- and vacuum-assisted deliveries. PGDM can also hinder the growth of fetuses, causing intrauterine
growth restriction (IUGR), if long-standing diabetic vascular disease results in decreased maternal blood flow to the placenta and fetus. After delivery, neonates of a PGDM pregnancy are susceptible to hypoglycemia, because they maintain an elevated metabolic state but no longer have access to the high glucose levels from their mothers. The best way to avoid the complications of PGDM is tight glucose control. For type 2 diabetics, this may necessitate switching from oral diabetic medication to insulin. Normal pregnancy is a time of increased metabolism, and this increased demand may unmask a woman’s previously hidden predisposition to glucose intolerance. Risk factors for GDM include obesity, a family history of DM, age greater than 25 years, and ethnicity including Hispanic and African. Different criteria are used to diagnose GDM. The American Diabetes Association (ADA) recommends a three-hour oral glucose tolerance test (OGTT) for diagnosis, although this may be less cost-effective than the World Health Organization (WHO) method, which uses a two-hour OGTT. Screening guidelines also differ. While some feel that all pregnant women should be screened for GDM, the ADA recommends that all pregnant women with at least one risk factor for GDM be screened between 24 and 28 weeks’ gestation or earlier if risk is greater. Pregnancies complicated by GDM are susceptible to many of the same adverse obstetric outcomes as PGDM, although these mothers do not already have some of the long-standing conditions associated with preexisting DM. Up to 50 percent of women with GDM go on to develop DM within 10 years of pregnancy. As with PGDM, the best treatment for GDM is glucose control, through diet and insulin therapy if necessary. SEE ALSO: American Diabetes Association (ADA); Diabe-
tes; Diabetes Type I (Juvenile Diabetes); Diabetes Type II; Diabetic Kidney Problems. Bibliography. G. Forsbach-Sanchez, H. E. Tamez-Perez,
and J. Vazquez-Lara, “Diabetes and Pregnancy,” Archives of Medical Research (v.36/3, 2005); F. Galerneau and S. E. Inzucchi, “Diabetes Mellitus in Pregnancy,” Obstetrics and Gynecology Clinics of North America (v.31/4, 2004). Jason Vassy Washington University in St. Louis
Diabetes Type I (Juvenile) The current obesity-associated diabetes epidemic has appropriately captured the attention of health professionals and the public. This epidemic is in type 2 diabetes mellitus (T2DM), a disease associated with insulin resistance followed by reduced insulin secretion. Five to 10 percent of cases of diabetes, however, are due to type 1 diabetes mellitus (T1DM), an autoimmune disease characterized by destruction of the cells in the pancreas that secrete insulin. The lifetime risk of T1DM is less than 0.5 percent, but the incidence varies with geographic region, from higher in Scandinavia to lower in Japan and China. Most cases of T1DM occur in childhood or early adulthood before age 30. In 1997, the American Diabetes Association introduced the terms type 1 diabetes mellitus to replace the previous terms insulin-dependent , or juvenile diabetes. The human body’s primary source of energy is the simple sugar glucose, one of the primary products of the digestion of a meal. Because of its importance for the function of the brain and other vital organs, glucose levels in the blood are normally tightly regulated by the pancreatic hormones insulin and glucagon, among others. The β-cells of a normal pancreas secrete insulin after a meal, which acts at receptors in the liver, muscles, and other organs to allow their uptake of glucose. Insulin also allows the body to turn free fatty acids (FFA) into triglycerides, the main component of adipose (fat) tissue. T1DM is an autoimmune disease in which the body’s own immune system destroys pancreatic β-cells, thereby eliminating insulin secretion. Without insulin, the body cannot use the glucose in the bloodstream, despite its abundance after a meal. The result is hyperglycemia (elevated blood glucose levels) and a paradoxical inability of the body’s tissues to use this glucose. To compensate for the lack of glucose utilization by the body, tissues break down protein and fats for energy, a situation similar to starvation. Once 80 percent of the β-cells in the pancreas are destroyed, the symptoms of diabetes manifest. symptoms and causes The classic symptoms of T1DM are due to hyperglycemia: increased thirst, increased consumption of liquids, and increased urination. The inability of the body to use glucose for energy causes other symptoms in T1DM, including weight loss despite an in-
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creased consumption of food. Such symptoms may prompt a healthcare provider to pursue a diagnosis of T1DM. Diabetes is diagnosed when the fasting plasma glucose (FPG) is ≥126 mg/dL (7.0 mmol/L) or when a random (nonfasting) plasma glucose is ≥200 mg/dL (11.1 mmol/L) in the presence of diabetic symptoms such an increased urination, thirst, blurred vision, or weight loss. Laboratory assays can also detect auto-antibodies, including anti-GAD antibodies, that cause the destruction of pancreatic βcells. Some individuals are found to be diabetic when they have diabetic ketoacidosis (DKA), a life-threatening condition in which the body’s inability to use glucose for energy results in the release of too much acid in the form of free fatty acids. People in DKA have abdominal pain, nausea, and vomiting and may progress to seizures or even coma without treatment, which includes insulin. There is a genetic predisposition to T1DM, as evidenced by the 30 percent risk in identical twins of type 1 diabetics compared to the 0.4 percent risk in people with no family history of the disease. Some of the predisposing genetic mutations have been identified, although they are not sufficient to cause T1DM. The distribution of these mutations in the human population varies with geographic location, explaining some of the ethnic differences in the prevalence of T1DM. The most important of these are genetic mutations in the HLA (human leukocyte antigen) region of chromosome 6, which account for 40 percent to 50 percent of the genetic risk for developing T1DM. Forty percent of children with T1DM have mutations in this region compared to 2 percent of children without the disease. Researchers have identified mutations in other chromosomes that are also associated with T1DM, albeit to a lesser degree. Genetic predisposition, however, is not sufficient to cause T1DM, since the majority of people with the higher-risk HLA mutations do not develop T1DM. Researchers have proposed several environmental triggers that may lead to T1DM in genetically predisposed individuals, including perinatal viral infections and exposure to certain foods like cow’s milk and cereals in infancy. None have been definitively associated with the etiology of T1DM, however. Most researchers believe that some environmental exposure triggers an autoimmune response in genetically predisposed individuals, resulting in antibodies directed against molecules in the pancreas
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necessary for insulin release, including glutamic acid decarboxylase (GAD). These antibodies cause the body’s own immune system to destroy the pancreatic β-cells, eliminating the ability of the pancreas to secrete insulin within a few months to years. The resulting lack of insulin causes hyperglycemia and wasting. Since much of the pathogenesis of T1DM, including possible environmental triggers, remains unidentified, there are as yet no effective ways to prevent this type of diabetes. Diabetes can result in many long-term medical complications during the life of a diabetic. The complications of diabetes are categorized as microvascular or macrovascular, according to the size of the blood vessels affected. Elevated glucose in the blood damages blood vessels and the organs to which they supply blood. The microvascular complications of diabetes include eye disease (retinopathy), kidney disease (nephropathy), and nerve disease (neuropathy). Diabetes is the top cause of blindness in adults in developed countries and of end-stage renal disease worldwide. The macrovascular complications of the disease include coronary artery disease and strokes, leading causes of mortality worldwide. Diabetes is considered to be a “risk equivalent” for coronary artery disease; that is, a diabetic is as likely to have a heart attack within 10 years as someone who has already had a heart attack. The nerve and vascular damage of diabetes also make it the leading cause of leg amputations in the United States. These potential complications make routine eye, kidney, heart, and foot care an important part of a diabetic’s healthcare. treatments Endocrinologists, physicians who treat hormone and metabolic diseases, care for type 1 diabetics. This care includes treatment with insulin, without which type 1 diabetics would not survive. In addition to survival, however, insulin helps prevent the above complications of T1DM by improving glycemic control, or maintenance of blood glucose levels within a normal range. The importance of glycemic control in type 1 diabetics was demonstrated in the Diabetes Control and Complications Trial (DCCT), a landmark prospective randomized trial that compared conventional insulin therapy with more intensive insulin therapy that used multiple daily injections or continuous insulin pump infusion. The more intensive therapy reduced glucose levels and
delayed or slowed the progression of microvascular complications. There is less evidence to suggest that glycemic control reduces the risk of macrovascular complications like coronary artery disease, but the advantages for microvascular complications clearly make glycemic control an important therapeutic goal. Diabetics are encouraged to check their blood glucose at different times throughout the day (fasting and nonfasting) with home finger-stick glucometers and record these values in a log. If any of these values are too high or low, the patient and his physician can adjust his insulin regimen accordingly. Plasma glucose levels before a meal should be 90–130 mg/dL (5.0–7.2 mmol/L), while the peak glucose level after a meal should be <180 mg/dL (<10.0 mmol/L). To get an overall idea of a patient’s glycemic control over the last three months, physicians will check a hemoglobin A1c (HbA1c) level, which should remain below 7 percent. Many different preparations of insulin exist that vary by how quickly they begin acting and for how long they act. Based on patients’ glucose logs, endocrinologists often prescribe combinations of short- and long-acting insulins for injection a couple of times per day. Some diabetics choose to use insulin pumps for continually delivery of a basal amount of insulin, to which they add greater amounts of insulin in response to elevated glucose readings or in anticipation of a meal. Moreover, the U.S. Food and Drug Administration (FDA) has approved inhaled insulin. The most serious side effect of insulin therapy is hypoglycemia, or having too little glucose in the blood. The symptoms of hypoglycemia include sweating, heart palpitations, and nausea, and if a hypoglycemic patient does not soon take in glucose either in the form of food or intravenous solution, he may progress to seizure or coma. See Also: Diabetes; Diabetic Eye Problems; Diabetic Kid-
ney Problems; Diabetic Nerve Problems.
Bibliography. K.M. Gillespie, “Type 1 Diabetes: Patho-
genesis and Prevention,” Canadian Medical Association Journal (v.175/2, 2006); A. Powers, “Diabetes Mellitus” in Harrison’s Principles of Internal Medicine, 16th edition. (McGraw-Hill, 2005). Jason Vassy Washington University in St. Louis
Diabetes Type II Diabetes mellitus is being called an epidemic by the World Health Organization (WHO), and 90 percent of the more than 170 million cases of diabetes worldwide are type 2 diabetes mellitus (T2DM), formerly called non-insulin–dependent or adult-onset diabetes. In contrast to type 1 diabetes, the T2DM epidemic has occurred concomitantly with the obesity epidemic, more prevalent in, but not limited to, the developed world. Although the number of diabetics in the United States more than doubled from 5.8 to 14.7 million people from 1980 to 2004, India and China currently have the most diabetics of any country. Wild and colleagues estimated that the global prevalence of diabetes will increase 39 percent from 4.6 percent in 2000 to 6.4 percent in 2030. Although type 1 diabetes is classically considered to be the diabetes of childhood, the prevalence of T2DM in children and adolescents has recently been increasing as these age groups are attaining a higher body mass index (BMI). Diabetes is the sixth leading cause of death in the United States, and WHO estimates that nine percent of deaths worldwide are attributable to the disease. Its adverse health consequences, including heart disease, blindness, limb amputation, and kidney disease, represent a tremendous burden to healthcare systems. Having diabetes increases an individual’s healthcare costs two to three times, much of which is due to increased hospitalizations. More than seven percent of Americans have diagnosed diabetes, but the disease and its complications account for almost 14 percent of American healthcare expenditures. Moreover, the American Diabetic Association (ADA) estimated that the direct and indirect expenditures of diabetes, including medical costs, lost workdays, disabilities, and deaths, totaled $132 billion in the United States in 2002. characteristics Unlike type 1 diabetes, T2DM is initially characterized by insulin resistance, not by decreased insulin production in the pancreas. Early in the disease process, the body’s tissues, including the liver, muscles, and adipose tissue, become resistant to the effects of insulin and therefore take up less glucose (sugar) from the bloodstream. This insulin resistance has been linked to obesity and specifically fat deposit in the central
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abdomen, although the pathway by which increased adiposity is associated with insulin resistance is not fully understood. To overcome insulin resistance, the pancreas secretes greater amounts of insulin to maintain proper glucose balance. Eventually, the pancreas cannot maintain this elevated insulin secretion, and insulin production declines, resulting in hyperglycemia and T2DM. The etiology of T2DM is still being elucidated, but the current paradigm is that certain individuals, including members of at-risk ethnic groups, have a genetic predisposition to T2DM, making them more likely to manifest the disease if they have additional environmental risk factors like physical inactivity or increased caloric intake. The prevalence of these atrisk mutations varies with ethnicity, and certain ethnic groups are at increased risk for T2DM, including African Americans, Latinos, Native Americans, Asian Americans, and Pacific Islanders. Some of this increased risk is mediated by a predisposition in these people to gain weight more easily than others, resulting in the insulin resistance associated with increased adiposity. Still, despite the importance of one’s genetic makeup in determining one’s risk for T2DM, the recent increase in the incidence of this disease gives evidence for its environmental risk factors, including weight gain, physical activity, and diet. For example, the risk for T2DM in Japanese immigrants to the United States soon matches the risk of T2DM of Americans more closely than that of native Japanese. Established environmental risk factors for T2DM include physical inactivity and increasing BMI, even within the normal range <25 kg/m2. Other risk factors for the development of T2DM include an age of 45 years or greater and a history of gestational diabetes. T2DM usually has a gradual onset and is asymptomatic early in the course of the disease, despite the “silent” damage that hyperglycemia causes in the body’s small and large blood vessels. For this reason, many type 2 diabetics already have eye, kidney, and nerve damage at the time their disease is diagnosed. Patients with risk factors for T2DM, including ethnicity, obesity, high blood pressure, and high cholesterol, should be screened for the disease. Other symptoms may prompt a healthcare provider to test a patient for diabetes, including increased thirst or urination. Two laboratory tests are used to
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define and diagnose diabetes: fasting plasma glucose (FPG) and the two-hour oral glucose tolerance test (OGTT), during which a patient’s glucose is measured two hours after drinking a 75-gram glucose solution. These tests can define diabetes in addition to impaired fasting glucose (IFG) and impaired glucose tolerance (IGT), “prediabetic” conditions associated with future risk of progression to T2DM. People with these conditions should institute lifestyle dietary and physical activity modification to prevent or delay the onset of T2DM. complications The complications of T2DM are categorized as microvascular or macrovascular, according to the size of the blood vessels affected, and are the reason that diabetes is costly in terms of mortality and healthcare expenditures. Elevated glucose in the blood damages blood vessels and the organs to which they supply blood. The microvascular complications of diabetes include eye disease (retinopathy), kidney disease (nephropathy), and nerve disease (neuropathy). Diabetes is the top cause of blindness in adults in developed countries and of end-stage renal disease worldwide. The macrovascular complications of the disease include coronary artery disease and strokes, leading causes of mortality worldwide. Indeed, DM is considered to be a “risk equivalent” for coronary artery disease; that is, a diabetic is as likely to have a heart attack within 10 years as someone who has already had a heart attack. The nerve and vascular damage of diabetes also make it the leading cause of leg amputations in the United States. The prevention of T2DM is thus an important public health initiative. Despite the significant genetic predisposition to T2DM, some cases of the disease can be prevented through lifestyle modification. The Nurses’ Health Study in the United States showed that modifiable lifestyle factors associated with a lower incidence of T2DM include a BMI<25 kg/m2, moderate physical activity at least 30 minutes per day, no smoking, and a diet high in fiber and polyunsaturated fat and low in trans fat and glycemic index. Randomized trials have shown that the risk of T2DM in those already at high risk for the disease (e.g., having impaired glucose tolerance), can be reduced with weight loss, increased physical activity and moderate calorie restriction such as a reduction of 250 to 500 calories per day.
The target of treatment for T2DM is glycemic control, or maintaining a diabetic’s blood glucose levels within a normal range. The United Kingdom Prospective Diabetes Study (UKPDS) demonstrated the importance of glycemic control for reducing diabetic microvascular complications. There is less evidence to suggest that glycemic control reduces the risk of macrovascular complications like coronary artery disease, but the advantages for microvascular complications clearly make glycemic control an important therapeutic goal. Diabetics are encouraged to check their blood glucose at different times throughout the day and report these values to their healthcare provider for optimization of their medical regimen. To get an idea of a patient’s overall glycemic control, physicians will check a hemoglobin A1c (HbA1c) level, a blood test correlated to the patient’s glycemic control in the past three months. Normal HbA1c levels are ≤5.0 percent, but this percentage increases in diabetics. Diabetics should aim to keep their HbA1c levels below 7 percent, with dietary measures, physical activity, and medications. Lifestyle modification is an essential component of the treatment of T2DM. Even modest weight loss can improve a type 2 diabetic’s insulin sensitivity and improve HbA1c levels. This weight loss should be accomplished by reducing the total number of calories consumed daily with a diet rich in fruits, vegetables, whole grains, lean meats, and low-fat dairy products. Increased physical activity is also essential for weight loss and maintenance; the current recommendations from the National Institutes of Health call for 30 to 60 minutes per day of moderate intensity activity such as brisk walking. Maintaining adequate glycemic control with diet and exercise alone is rare in a diagnosed diabetic, and so medications are important adjuncts to lifestyle modification. There are several classes of oral diabetic medications, including the sulfonylureas, the biguanides such as metformin, the thiazolidinediones, the α-glucosidase inhibitors, and the meglitinides. Metformin is often the firstline agent for obese patients with T2DM, because it can cause a modest degree of weight loss. If one medication is insufficient for glycemic control, physicians may choose a combination regimen of two or more agents. Ultimately, some type 2 diabetics may require insulin if oral medications do not provide adequate glycemic control. Because type 2 diabetics
Diabetic Eye Problems
often have other risk factors for heart disease, it is also important to aggressively treat their hypertension and high cholesterol, if present. Dietary education and routine eye and foot examination are also important components of diabetic health maintenance. See Also: Diabetes; Diabetes Type 1. Bibliography. Christos Mantzoros, ed., Obesity and
Diabetes (Humana Press, 2006); Sally M. Marshall and Allan Flyvbjerg, “Prevention and Early Detection of Vascular Complications of Diabetes,” British Medical Journal (v.333/7566, 2006); Sarah Wild, et al., “Global Prevalence of Diabetes: Estimates for the Year 2000 and Projections for 2030,” Diabetes Care (v.27, 2004). Jason Vassy Washington University in St. Louis
Diabetic Eye Problems One of the complications of diabetes mellitus (DM) is diabetic retinopathy, a disease of the retina or lightsensitive part of the eye. It is the most common cause of blindness in adults 20–74 years old in developed countries such as the United States. It is estimated that almost all type 1 diabetics and greater than 60 percent of type 2 diabetics have some degree of diabetic retinopathy after having DM for 20 years. About 20 percent of newly diagnosed type 2 diabetics have evidence of this condition at the time of diagnosis. Clinical course The retinal changes of DM are readily seen through an ophthalmoscope. As in other locations such as the kidneys and legs, the hyperglycemia of diabetes damages small blood vessels in the retina. The first evidence of this damage is called nonproliferative retinopathy, seen as small red bulges in the vessels called microaneurysms. With time, less oxygen is delivered to the retina as a result of this vascular damage, and some areas of the retina may infarct. Patients may notice no change in vision during this early stage, although some visual acuity may be lost if the damage involves the macula, the area of the retina responsible
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for the sharpest vision. New vessels grow in the retina to compensate for insufficient oxygen levels. This proliferative retinopathy can be seen on ophthalmologic examination as an overabundant number of small vessels. These new vessels can result in irreversible vision loss in two ways. They are fragile and prone to rupture, causing hemorrhage and scarring. These vessels can also contract and cause retinal detachment. In addition to retinopathy, diabetics are also more likely to get cataracts and glaucoma than the general population. Screening, Prevention, Treatment Because the damage is often irreversible by the time a person notices visual impairment, screening for diabetic retinopathy is important in the care of any diabetic patient. The American Diabetes Association (ADA) recommends that newly diagnosed type 2 diabetics receive a comprehensive dilated eye examination by an ophthalmologist at the time of diagnosis and then yearly thereafter. Type 1 diabetics should receive yearly eye examinations beginning three to five years after diagnosis and not usually before age 10. More frequent examinations are necessary if retinal damage is discovered. Good glycemic control, as measured by blood glucose and hemoglobin A1c levels, is important in preventing the progression of diabetic retinopathy and preserving vision. Treating high blood pressure in diabetics, with drugs such as β-blockers or angiotensin-converting enzyme (ACE) inhibitors, has also been shown to slow the progression of retinopathy. Once retinopathy is seen on ophthalmologic examination, early treatment is necessary to prevent further loss of visual acuity. Standard treatment is laser photocoagulation, in which a laser is used to close or destroy the abnormal retinal vessels that are prone to rupture. While this procedure will not restore any vision that has already been lost, it has been shown to slow further vision loss. In the case of extensive damage or retinal detachment, a vitrectomy is performed, a surgical procedure in which the scar tissue and cloudy bloody fluid in the eye are removed. In the case of detachment, retinal reattachment can also be performed during a vitrectomy, although this is successful in only about half of cases. SEE ALSO: Diabetes; Eye Diseases; Ophthalmology.
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Bibliography. American Diabetes Association, “Eye
Complications,” http://www.diabetes.org /type-2-diabetes/ eye-complications.jsp (cited June 2007); Donald S. Fong, et al., “Diabetic Retinopathy,” Diabetes Care (v.26/1, 2003). Jason Vassy Washington University in St. Louis
Diabetic Foot Problems Foot disease is a prevalent complication of diabetes mellitus (DM) and is the most common cause of limb amputation in the United States. The lifetime risk of foot ulcers in DM is 15 to 25 percent and 5 percent of diabetics ultimately require amputation. Foot infections are now the leading cause of diabetes-related hospitalized days. Diabetic foot disease represents a significant cost for healthcare systems, much of which could be reduced through preventive measures. The symptoms of diabetic foot disease include numbness and tingling in the feet that is worse at night. Foot infections manifest as redness, warmth, pain, and possibly pus around a foot ulcer. Diabetic foot disease develops for a number of reasons. Diabetic nerve dis-
Studies have suggested that acupuncture may benefit diabetes patients with no adverse side effects.
ease decreases the sensation in the feet and allows undetected injuries and improper foot placement during walking, which can lead to deformed foot joints and calluses. Diabetic nerve disease also decreases sweating in the feet, and the lack of moisture can predispose to cracking, which can introduce infection. Decreased blood flow to the foot also reduces oxygen delivery to the tissue of the foot, resulting in ulcers with slower healing. Certain bacteria and fungi thrive in the hyperglycemia of diabetes, and the immune response to these infections is impaired in diabetics. Fungal infections like athlete’s foot can cause cracks in the feet, upon which bacterial infections can superimpose. Often beginning around the nails, infections can range in severity from local skin infection (cellulitis) to infection of the deep tissue and even bone (osteomyelitis) to irreversible death of tissue (gangrene). Prevention with foot care is the most important intervention against diabetic foot disease. Diabetics should avoid tight-fitting shoes and may need insoles and special fitted shoes with extra depth and width. They should also wear loose-fitting cotton socks and avoid walking barefooted. The feet should be inspected daily, with a mirror if necessary, and care should be taken to avoid breaks in the skin during nail trimming, for example. The feet should be cleaned with lukewarm water and mild soap and patted dry. Diabetics should undergo yearly foot examinations by foot care specialists, including assessment of blood flow and neurologic function and inspection for ulcers and infection. Smoking cessation and tight glycemic control will slow the progression of foot disease. Treatment of diabetic foot depends on its severity. Superficial ulcers may only require debridement (removal) of dead tissue, and superficial infections may respond to oral antibiotics. Detected by X-ray, magnetic resonance imaging (MRI), and/or bone biopsy, infection of deeper tissue or bone may require hospitalization for intravenous antibiotics, along with removal of the infected tissue and bone. Severe infections may spread to the bloodstream and cause major systemic illness. After the elimination of diabetic foot infections, relapses are common. Amputation of the leg either above or below the knee may be required for gangrene, from which the tissue will not recover. In other cases where diminished blood flow is the primary problem, vascular surgery may be able to restore blood flow to the leg.
Diabetic Kidney Problems
See Also: Diabetes; Diabetes Type I (Juvenile); Diabetes
Type II.
Bibliography. Andrew Bolton, et al., “The Global Burden
of Diabetic Foot Disease,’ The Lancet (v.366/9498, 2005); Benjamin Lipsky, “A Report from the International Consensus on Diagnosing and Treating the Infected Diabetic Foot,” Diabetes Metab Res Rev (v.20/Suppl, 2004).
Jason Vassy Washington University in St. Louis
Diabetic Kidney Problems Diabetes mellitus is the leading cause of kidney failure in the United States. Although the early stages of diabetic kidney disease, or diabetic nephropathy, are subtle and often go unnoticed, the disease can eventually result in end-stage renal disease (ESRD) requiring kidney transplantation or dialysis therapy. This potentially deadly complication of diabetes mellitus has grown to great public health significance, given the high cost of dialysis and the shortage of organ donations. The U.S. Centers for Disease Control and Prevention (CDC) reported that 300,000 new cases of diabetic ESRD occurred in the United States in 2002. This absolute number continues to grow, although the proportion of diabetics who get ESRD seems to be declining. Still, ESRD treatment cost the United States Medicare system $25.2 billion in 2002. Diabetic nephropathy can occur with both type 1 and 2 diabetes mellitus, although it may occur earlier in life in type 1 diabetics, because their disease generally begins in childhood. Certain ethnic and racial groups are at greater risk for diabetic kidney disease, including African Americans and Mexican Americans. Differences in risk may be due to socioeconomic or genetic factors. Diabetic nephropathy is considered one of the microvascular complications of diabetes mellitus, resulting from damage to small blood vessels including those in the kidneys. The high glucose levels of diabetes damage the blood vessels and kidney tissue itself, causing a gradual decline in kidney function. This microscopic damage can be seen by taking a biopsy of the kidney, although this invasive procedure is often
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not necessary for the diagnosis of diabetic nephropathy. The natural history of diabetic nephropathy is a gradual process that begins with albuminuria, a condition in which the kidneys leak more protein into the urine than normal, particularly the protein albumin. Normal urinary albumin excretion is less than 30 mg/ day; albuminuria between 30 and 300 mg/day and greater than 300 mg/day is called microalbuminuria and macroalbuminuria (proteinuria), respectively. Microalbuminuria causes no symptoms and may already be present at the time that diabetes mellitus is diagnosed. Urinary albumin levels can be measured by using dipsticks tests on a single urine sample, by analyzing a patient’s urine after a 24-hour collection period, or by testing the urinary ratio of albumin to creatinine, a waste product eliminated in the urine. With the worsening of kidney disease, microalbuminuria may progress to macroalbuminuria, which may in turn progress to an elevated creatinine level in the blood, representing the kidneys’ inability to adequately remove this waste. To track the progression of diabetic nephropathy, nephrologists, physicians who specialize in the kidney, follow a patient’s blood creatinine levels and glomerular filtration rate (GFR), a measure of the kidneys’ function. Kidney function may decline such that survival is not possible without kidney replacement therapy: dialysis or kidney transplant. About 2 percent of diabetics per year progress from macroalbuminuria to increased creatinine levels or ESRD. Once a person has macroalbuminuria, the median time to renal replacement therapy is 2.5 years. The most effective way to prevent and treat diabetic nephropathy is through intensive glycemic control, measured by a patient’s blood glucose levels and hemoglobin A1c (HbA1c) concentration. Treating high blood pressure in diabetics has also proven important to slow the progression of diabetic nephropathy, and the angiotensin-converting enzyme (ACE) inhibitors and angiotensin receptor blockers (ARB) are particularly effective drugs in decreasing diabetic albuminuria. Dietary protein restriction may also slow the progression of kidney disease. A patient who progresses to ESRD requires kidney transplantation or dialysis, a therapy whereby the patient’s blood is cycled through a machine to remove the wastes normally filtered by the kidneys. Neither treatment is without its complications: kidney transplantation
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requires immunosuppressant drugs to prevent rejection of the new organ and dialysis is an invasive procedure often performed three times a week. SEE ALSO: Dialysis; Kidney Failure and Dialysis. Bibliography. A. I. Adler, et al., “Development and Pro-
gression of Nephropathy in Type 2 Diabetes: The United Kingdom Prospective Diabetes Study (UKPDS 64),” Kidney International (v.63, 2003); U.S. Renal Data System, “USRDS 2004 Annual Data Report: Atlas of End-Stage Renal Disease in the United States, National Institutes of Health, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD, 2004,” American Journal of Kidney Diseases (v.45/Suppl 1, 2005). Jason Vassy Washington University in St. Louis
Diabetic Nerve Problems The disease processes of diabetes mellitus cause injury to the nerves of the body. A common complication of long-standing diabetes mellitus is therefore diabetic neuropathy, a dysfunction of several of these nerves. Diabetes can affect nerves of a variety of functions and locations in the body. The most common example of diabetic neuropathy, however, is peripheral diabetic neuropathy, in which a loss of sensation first occurs in the most distal parts of the extremities, starting with the soles of the feet. Diabetics lose pain sensation in their feet and are thus unaware of small injuries to their feet, including minor sores from walking without shoes or from gravel in their shoes. With time, these unnoticed ulcers can become infected, a process aided by the poor circulation and depressed immune function that diabetes brings. Without treatment, these infections may require limb amputation. Types of Diabetic Neuropathy Distal symmetric polyneuropathy, also known as peripheral neuropathy, is classically described as having a “stocking-glove” distribution. That is, the loss of sensation begins in the feet and, over time, pro-
gresses up to the knees before including the fingers. The loss of sensation is symmetric and includes the inability to detect pain, vibration, pressure, and joint position. In addition to the infected ulcers described above, peripheral neuropathy can also eventually result in deformed Charcot joints of the foot, because the feet do not appropriately sense and respond to the contour of the surface on which they walk. More rare, diabetics can experience painful diabetic neuropathy, characterized by burning, shooting, lightning-like pain in the legs. A third type of diabetic nerve problem is diabetic autonomic neuropathy. The autonomic nervous system controls numerous bodily functions, such as circulation, respiration, digestion, and reproduction. Diabetic autonomic neuropathy, therefore, can manifest in many ways, including gastrointestinal and genitourinary dysfunction, rapid heartbeat, and lightheadedness on standing due to a drop in blood pressure. In addition to sensory and autonomic nerves, diabetes mellitus can also damage motor nerves, nerves that control muscle contraction. Diabetic motor neuropathy can be asymmetrical and may occur in locations such as the limbs and the muscles that control eye movements. Clinical Aspects of Diabetic Neuropathy Diabetic neuropathy may affect as many as 10 percent of diabetics, and its risk increases with poorer glucose control. The precise cause of diabetic nerve damage is not clear, although the high blood glucose levels and poor blood flow that are characteristics of diabetes mellitus are most likely involved. There are many other nondiabetic causes of neuropathies, and a physician must rule these out before diagnosing diabetic neuropathy. Nevertheless, the diagnosis must always be considered in a known diabetic patient, and all diabetics should receive routine neurological examinations. Noninvasive diagnostic tests for diabetic neuropathy include the basic neurological examination that tests the motor function and sensation to pinprick, vibration, and temperature. Evidence of autonomic neuropathy is detected by monitoring changes in blood pressure and heart rate difference between sitting and standing. Definitive diagnosis requires further testing such as nerve conduction studies and
Diabetic Teeth and Gum Problems
nerve and skin biopsies. As with most other complications of diabetes, the best treatment for diabetic neuropathy is glycemic control, keeping the blood glucose level low through diet and/or treatment with oral diabetes medications or insulin. Reducing hyperglycemia decreases an individual’s chance of getting diabetic neuropathy. Painful diabetic neuropathy can be treated symptomatically with tricyclic antidepressants and antiseizure medications such as phenytoin, gabapentin, and carbamazepine. SEE ALSO: Diabetes;Diabetic Foot; Neurology. Bibliography. V. Bansal, J. Kalita, and U. K. Misra, “Dia-
betic Neuropathy,” Postgraduate Medical Journal (v.82, 2006). Jason Vassy Washington University in St. Louis
Diabetic Teeth and Gum Problems Both type 1 and type 2 diabetes mellitus (DM) are associated with a higher prevalence of periodontitis, an infection of the gums and the tooth-supporting bones and ligaments of the mouth. Its symptoms include redness, swelling, and pain around the teeth, in addition to loose teeth. The disease progression includes the development of plaques between the teeth and gums, infection of the gums (gingivitis) when bacteria multiply in the plaque, and finally destruction of the tissue supporting the teeth, eventually resulting in tooth loss. About 50 percent of the U.S. adult population may have gingivitis, manifested as bleeding gums, while at least 14 percent have moderate to severe periodontitis. Although infection with oral bacteria is necessary for periodontitis, other risk factors must be present for the disease to progress. Smoking and poorly controlled DM are its major modifiable risk factors. The National Health and Nutrition Examination Survey (NHANES) III found the prevalence of periodontitis to be 17.3 percent in adult diabetics compared to 9 percent in nondiabetics. Moreover, diabetics experience earlier and more severe periodontitis than nondiabetics, and diabetics with poorer glycemic control
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have worse periodontal disease than well-controlled diabetics. Studies have shown no difference between diabetics and nondiabetics, however, in their response rates to the treatment of periodontitis, which consists at first of mechanical scraping and antibiotic therapy such as tetracycline or doxycycline. DM may increase the likelihood of periodontal infections for a number of reasons. The diabetic damage to blood vessels impairs oxygen delivery to tissues, which creates a favorable environment for the growth of certain bacteria. This vascular damage also impedes the delivery of immune cells, which already have decreased function due to DM, to sites of infections. Diabetics have impaired production of collagen, a necessary protein for proper tooth attachment. DM is also associated with a higher rate of xerostomia, or dry mouth due to decreased saliva production, which may promote the progression of infection in plaques. An alternative or complementary explanation is that some individuals may have genetic predispositions to both DM and periodontitis. An interesting idea is that periodontal disease itself may worsen diabetes. Inflammatory molecules (cytokines) released from periodontal pockets of infection may interfere with insulin and glucose metabolism. There is evidence to suggest that periodontitis may worsen glycemic control in diabetics. Additionally, temporary improvement in glycemic control has been reported after treatment of periodontitis with antibiotics. Good oral hygiene, including brushing, flossing, and routine dental care with the removal of plaque, is important for the prevention of periodontitis in diabetics and nondiabetics alike. Gingivitis usually responds to these measures also, but more advanced periodontitis may require the surgical removal of infected tissue. Systemic antibiotics like tetracycline or doxycycline may also be administered. As with most complications of DM, good glycemic control is important and may reduce the severity of periodontitis in diabetics. SEE ALSO: Diabetes; Diabetes Type I (Juvenile); Diabetes
Type II.
Bibliography. I.B Bender, A.B Bender, “Diabetes Mel-
litus and the Dental Pulp,” Journal of Endodontics (v.29/6, 2003); W.A. Soskolne, A. Klinger, “The Relationship be-
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tween Periodontal Diseases and Diabetes: An Overview.” Annals of Periodontology. (v.6/1, 2001). Jason Vassy Independent Scholar
Diagnostic Imaging Diagnostic imaging is the use of X-ray, ultrasound, radioactive isotopes, or magnetic resonance to generate graphical images of the inside of the human body for diagnostic purposes. More than 90 percent of all imaging can be performed using basic X-ray equipment and/or simple ultrasound machines. Diagnostic imaging is a prerequisite for the appropriate and successful treatment of at least a quarter of all patients worldwide. The use of diagnostic imaging is justified when needed to exclude disease, to prove the existence of a pathological process needing treatment, to assist in planning of treatment, or to follow the course of a disease already diagnosed and/ or treated. Diagnostic imaging makes proper treatment possible. Without such examinations, it can be more difficult for clinicians to determine appropriate treatment. For example, reports from some countries indicate that a significant portion of all abdominal surgical interventions (explorative laparotomy) may have been avoided if simple diagnostic imaging services such as ultrasound had been available. Because effective diagnostic imaging can reduce unnecessary procedures, diagnostic imaging services should be developed as an integral part of national healthcare systems. It should be planned according to country, region, or area needs, and the local social and economic structure. X-Rays X-rays (radiographs) are the most common and widely available diagnostic imaging technique. Even if more sophisticated tests are needed, an X-ray is often first approached. The part of the body being pictured is positioned between the X-ray machine and photographic film, while electromagnetic waves (radiation) travel through the patient’s body. Sometimes, to make certain organs stand out the patient is asked to drink or be injected with barium sulfate or a dye.
Computed Tomography (CT) Scans A CT scan is a modern imaging tool that combines X-rays with computer technology to produce a more detailed, cross-sectional image of the body. A CT scan allows a doctor see the size, shape, and position of structures that are deep inside the body, such as organs, tissues, or tumors. An X-ray tube slowly rotates around the patient, taking many pictures from all directions. A computer combines the images to produce a clear, two-dimensional view on a television screen. CT scans are used when there are problems with a small, bony structure or if there is severe trauma to the brain, spinal cord, chest, abdomen, or pelvis. As with a regular X-ray, sometimes barium sulfate or a dye is used to make certain parts of the body show up better. A CT scan costs more and takes more time than a regular X-ray, and it is not always available in small hospitals and rural areas. Magnetic Resonance Imaging (MRI) MRI is another modern diagnostic imaging technique that produces cross-sectional images of the body. Unlike CT scans, MRI works without radiation. The MRI tool uses magnetic fields and a sophisticated computer to take high-resolution pictures of bones and soft tissues. The MRI creates a magnetic field around the patient and then pulses radio waves to the area of the patient’s body to be pictured. The radio waves cause tissues to resonate. A computer records the rate at which body’s various parts (tendons, ligaments, nerves, etc.) give off these vibrations, and translates the data into a detailed, two-dimensional picture. An MRI may help doctors to diagnose torn knee ligaments and cartilage, torn rotator cuffs, herniated disks, hip and pelvic problems, and other problems. An MRI may take 30 to 90 minutes, and is not available at all hospitals. Ultrasound Medical ultrasonography uses high-frequency sound waves of between 2.0 to 10.0 MHz that are reflected by tissue to varying degrees to produce a two-dimensional image, traditionally on a television monitor. This is often used to visualize the fetus in pregnant women. Other important uses include imaging the abdominal organs, heart, male genitalia, and the veins of the leg. While it may provide less anatomical information than techniques such as CT or MRI, it has several advantages that make it ideal as a first-line
test in numerous situations, in particular that it studies the function of moving structures in real time. It is also very safe to use, as the patient is not exposed to radiation and is also relatively cheap and quick to perform. Ultrasound scanners can be taken to critically ill patients in intensive care units, avoiding the danger caused while moving the patient to the radiology department. The real-time moving image obtained can be used to guide drainage and biopsy procedures. Doppler capabilities on modern scanners allow the blood flow in arteries and veins to be assessed. Electron Microscopy The electron microscope is a microscope that can magnify very small details with high resolving power because of the use of electrons as the source of illumination. Its usefulness has been greatly reduced by immunohistochemistry, but it is still irreplaceable for the diagnosis of kidney disease, identification of immotile cilia syndrome, and many other tasks. Challenges in Developing Countries There are many challenges in diagnostic imaging in developing countries. Mainly, there is a severe lack of safe and appropriate diagnostic imaging services (i.e., basic X-ray and ultrasound) in large parts of the world. Imaging facilities are simply not available or not functioning. The lack of equipment could be due to lack of resources or poor maintenance of existing equipment (also linked to lack of available parts). Additionally, in many countries a large number of images are of poor quality and are of no diagnostic use. However, even if proper equipment is available, there is a lack of adequately trained medical specialists including radiographers/technologists. Inadequate training means a lack of qualified personnel, and improper use of equipment as well as incorrect interpretation of images. Finally, regardless of the type of equipment and procedures used, diagnostic imaging requires a rigid infrastructure that often does not exist in developing countries. This infrastructure includes trained medical, technical, and engineering staff; radiation protection measurements; regulations; reliable supplies of clean water, electric power, spare parts and consumables; and adequate air-quality control. The goal of the World Health Organization (WHO) working area for diagnostic imaging is to make safe
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and reliable diagnostic imaging services available to as many as possible, advise and support those working in the field developing and maintaining diagnostic imaging services, and promote the importance of safe and appropriate diagnostic imaging services. WHO suggests that diagnostic imaging services should be developed as an integral part of national healthcare systems, according to the needs and social and economic structure of the country, region, and area. It also suggests that the services be regulated by governments in accordance with international standards appropriate to the level of the healthcare system at which they are provided and appropriate to the therapeutic capabilities that are available. In addition to close collaboration with various United Nations agencies, and especially with the International Atomic Energy Agency (IAEA) in Vienna, various WHO collaborating centers, and nongovernmental organizations, the most important global collaboration takes place in the Global Steering Group for Education and Training in Diagnostic Imaging. This group was officially established after a WHO meeting on Training and Education in Diagnostic Imaging held in Geneva, Switzerland, May 31–June 3, 1999, and the overall objective of this group is to try to coordinate various training activities organized by international and regional societies, and join forces to improve quality, quantity, and equity of diagnostic imaging services worldwide, but with strong emphasis on countries in most need. SEE ALSO: Back Injuries; Fractures; Kidney Diseases (Gen-
eral); Pregnancy; World Health Organization (WHO).
Bibliography. R. M. Califf, “Evaluation of Diagnostic
Imaging Technologies and Therapeutics Devices: Better Information for Better Decisions: Proceedings of a Multidisciplinary Workshop,” American Heart Journal (v.152/1, 2006); S. Demeter, “Socioeconomic Status and the Utilization of Diagnostic Imaging in an Urban Setting,” Canadian Medical Association Journal (v.173/10, 2005); “Diagnostic Imaging Still Threatened by Shortages,” Lancet Oncology (v.5/6, 2004); Lee Goldman, ed., Cecil Textbook of Medicine, 22nd ed. (Saunders, 1999); John Noble, Textbook of Primary Care Medicine, 3rd ed. (Mosby, 2000). Barkha Gurbani UCLA School of Medicine
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Diagnostic Tests
Diagnostic Tests Diagnostic tests are used by healthcare workers to help determine the presence or absence of a disease or other health condition. Diagnostic tests can be grouped into two basic categories: medical or psychological. Within these two categories, there are many subsets of tests, used for a variety of purposes. The effectiveness and reliability of a diagnostic test is an important factor that must be taken into consideration when interpreting results. An accurate test is the best means to a proper diagnosis. The term diagnostic test can be misleading, because there are many reasons for using them beyond making an initial diagnosis. For example, diagnostic tests may also further define the illness, such as a cancer subtype. A more specific diagnosis may help guide the most effective treatment protocol and can also monitor treatment effectiveness. Psychological diagnostic tests may also be used to assist in prognosis by referring to longitudinal data of outcomes of patient with similar diagnoses. Quality and Effectiveness The quality and effectiveness of a diagnostic test is often measured by its accuracy. The accuracy of a test can be evaluated through four basic factors: sensitivity, specificity, positive, and negative predictive values. The sensitivity of a test is the probability that the test results reveal accurate diagnosis of an existing disease. The sensitivity is the proportion of accurate diagnoses correctly identified by the test. The specificity of a test is the probability that the test results will accurately identify individuals without the targeted disease. The positive predictive value of a test measures the percentage of individuals with a positive test result who actually have the disease. The negative predictive value measures the percentage of individuals with a negative test that do not have the disease. Types of Medical Tests Analysis of body fluids commonly includes of tests of the blood, urine, as well as the fluid surrounding the spinal cord and brain (cerebrospinal fluid). Less commonly, fluids such as sweat, saliva, or fluid from the digestive tract are assessed. Body fluid analysis can be used for many different purposes, including determining whether a person has an infection to deter-
mining whether a person has cystic fibrosis. Imaging provides a picture of the inside of the body. The most common test in this category is the X-ray. Some other commonly used examples are ultrasound, radioisotope (nuclear) scans, computed tomography (CT) scans, magnetic resonance imaging (MRI), and positron emission tomography (PET) scans. The test is selected based on what the examiner is wishing to determine, and the cost of each exam varies considerably. Endoscopy is a test that looks inside the body. An endoscope is a long flexible tube that has a camera and light inside it, permitting a physician to view images on a monitor during the procedure. An endoscope may be passed through the mouth to look at the esophagus or stomach (esophagogastroduodenoscopy), or can be passed through the rectum to look in the large intestine (colonoscopy). A newer endoscopic test consists of swallowing an extremely small capsule that contains a camera, and that takes pictures, permitting observation of areas without use of anesthesia. Measurement of body functions involves documenting and analyzing the different activity levels of different organs. For example, an electrocardiogram (ECG) records the electrical impulses of the heart at rest and an electroencephalogram (EEG) records the electrical changes of the brain during mental activity or rest. Biopsy involves removing a sample of tissue for examination. Only small samples are required because the examination is commonly done with a microscope. Common biopsy areas include skin, breast, lung, liver, kidney, intestine, and bone. Analysis of genetic material includes testing skin, blood, or bone marrow cells, and focuses on abnormalities of chromosomes and/or genes. DNA analysis is a component of gene analysis. Genetic testing is used with both children and adults to determine whether a disease is present, or if there is an increased risk of a disease. Genetic testing can also be done with individuals to determine the likelihood that a particular disease will be passed to their offspring. Psychological Testing Psychological testing can be measured through several formats. Norm-referenced tests (NRTs) compare a person’s score against the scores of people who have already taken the same exam, called the norming group. Groups can be normed by age, ethnicity,
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Body fluid analysis can be used for many different purposes, including determining whether a person has an infection. The effectiveness and reliability of a diagnostic test must be taken into consideration when interpreting results.
or disability. Criterion referenced tests compare an individual’s performance to a level of mastery. When reviewing test results, it is important to understand that most tests are standardized, meaning there are detailed instructions for administering the test, which requires specialized training in administration and scoring. This ensures the test is administered the same way to every individual, permitting comparison of results. Standardization is important because it affects the reliability and predictability of the test. The reliability of a test refers to how accurately the test measures some trait. In other words, if an individual is given a particular test at two different times several days apart, if environmental factors are similar, the individual should obtain similar scores. If the scores differ significantly from one session to the next, the test is not reliable. The validity of a test refers to the ability of the test to measure what it claims to measure. For example, the validity of an IQ test is based on how accurately it measures components of intelligence. Psychological and psycho-educational tests are another category of diagnostic tests. They provide an
avenue to identify and measure characteristics of an individual to norms based on age or behavior. Intelligence Tests. Intelligence tests are designed to measure a variety of mental functions including reasoning, comprehension, and judgment. They are used to obtain an idea of a person’s intellectual potential, and also to assess areas of brain dysfunction, such as in attention, memory, or visual perception. Intelligence tests are comprised of multiple subtests, which include verbal and nonverbal components. Intelligence tests are viewed as excellent predictors of academic achievement and provide a clearer picture of mental strengths and weaknesses. Intelligence tests can be categorized into two groups. Group intelligence tests are frequently used as screening assessment of “giftedness.” Commonly used tests in this category are the Otis-Lennon School Ability Test (OLSAT) and the Iowa Cognitive Abilities Test (COGAT). Individual tests of intelligence differ from group tests because they have more subtests and allow the administrator to vary the level of difficulty based on the individual’s initial performance. They also allow prompting if the individual’s answer
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is unclear. The most widely used intelligence tests are the Stanford-Binet, the Wechsler Intelligence Scale for Children (WISC), the Wechsler Adult Intelligence Scale (WAIS), and the Kaufman Assessment Battery for Children (Kaufman-ABC). The standardization and norming of these tests provide a uniform method to compare individual performance with a peer group. Intelligence testing is one of the primary tools for diagnosing children with mental retardation and learning disabilities. Academic Tests. Academic tests are used to measure skills such as reading, spelling, vocabulary, arithmetic, and writing, and can be administered in group or individual format. Group testing is commonly done in the school system, where students are tested at a particular grade level. Scores are standardized, and can be used to compare academic achievement within the same grade locally as well as nationally. These include the Comprehensive Tests of Basic Skills (CTBS) or the Iowa Tests of Basic Skills. Individually administered achievement tests are used more frequently to help identify concerns in specific academic areas. Individual achievement tests differ from group tests because they provide flexibility to adjust degree of testing difficulty to individual level of achievement, and may also allow for prompting. Both types of tests can be used to help identify intellectual giftedness or learning disabilities, by looking for discrepancies between IQ score and components of the achievement scores. Assessment of Personality. Personality tests can be separated into two categories and are designed to evaluate an individual’s thoughts, emotions, attitudes, and behavioral traits. The first category is objective testing, which includes testing via inventories questionnaires, self-report measures, and rating scales. Some frequently used instruments in this category are the Minnesota Multiphasic Personality Inventory-Adolescent (MMPI-A), the Behavior Assessment Scale for Children (BASC), and the Beck Depression Inventory (BDI). The second category of personality assessment is projective testing. This category utilizes ambiguous stimuli open for individual interpretation. The focus of this type of testing is that an individual’s reactions or responses to ambiguity will mirror facets of their personality. Projective drawing, storytelling, and inkblots are frequently used types of tests.
Neuropsychological Tests. Neuropsychological testing is often used to diagnose and monitor brain damage and dysfunction. A comprehensive assessment measures various aspects of cognitive functioning, including intelligence, attention and concentration, verbal and visual memory, language functioning, visual spatial functioning, motor abilities, sensory-perceptual processing, abstract reasoning, executive functioning (e.g., planning, self-monitoring, inhibition of impulses, and mental flexibility), and academic functioning. Some widely used neuropsychological tests are the Luria-Nebraska, and the Halstead-Reitan. Measures such as these enable neuropsychologists to isolate and diagnose organic brain impairment. It can also assist in the development of rehabilitation programs for cognitively impaired patients. Diagnostic tests address a broad spectrum in areas of medical and mental health. Validity and reliability are essential components of assessing diagnostic tests results. In other words, diagnostic tests should be able to identify between patients who have a particular health condition from those who do not have the health condition. In addition, diagnostics tests are helpful because they can be used to measure various stages of a disease and monitor the efficacy of different treatments. SEE ALSO: Attention Deficit Disorders; Bladder Diseases;
Bleeding Disorders; Biomarkers; Bipolar Disorder; Cancer; Child Development; Genetic Testing/Counseling.
Bibliography. A Lawyer’s Guide to Psychological As-
sessment of Adolescents (National Juvenile Defenders Center, U.S. Department of Justice, 2003): L. Aiken, Psychological Testing & Assessment (Allyn & Bacon, 2005); H. S. Levin, “A Guide to Clinical Neuropsychological Testing,” Archives of Neurology (v.51/9, 1994); E. Benson, “Psychologists Are Broadening the Concept of Intelligence and How to Test It,” Monitor on Psychology (v.34/2, 2003); Jerome M. Sattler, Assessment of Children: Behavioral and Clinical Applications, 4th ed. (Jerome M. Sattler, 2002). Gautam J. Desai, D.O. Elizabeth K. McClain, Ed.S. Kansas City University of Medicine and Biosciences College of Osteopathic Medicine
Dialysis
Dialysis Dialysis is a means of preserving one’s life. It is the act of an external machine performing the function of an internal organ. When the kidneys are no longer able to filter waste products from the body, concentrate urine, or preserve electrolytes (minerals in one’s blood and body fluid that affect many important aspects of normal balance in the body), then an individual is said to be in kidney failure, or renal failure. Dialysis is a cure for renal failure for many individuals. There are two types of dialysis techniques: peritoneal dialysis and hemodialysis. Peritoneal dialysis works by circulating a solution through the fluids of the abdomen. Hemodialysis works by circulating one’s blood through a special machine that contains special filters to remove waste products. Renal failure occurs when the kidneys fail to excrete harmful waste products. This may occur suddenly, acutely, or over a period of time, chronically, which may eventually lead to or end-stage renal disease (ESRD), which is a complete dysfunction of the kidneys. The etiologies of the two disease process are vast ranging from hereditary disorders to lifestyle choices. Dialysis is a treatment modality typically used to treat chronic renal failure. Diabetes and hypertension are the two most common causes of chronic renal failure and ESRD. Peritoneal dialysis involves the use of a catheter, a soft tube. The tube is used to fill the abdomen with a dialysis solution which contains dextrose, a sugar that will pull wastes and extra fluid from the blood into the abdominal cavity, where the solution is present. The dialysis solution and the waste products from the blood are then drained out of the body via the catheter. This process of filling the abdomen and then draining it is called an exchange and takes approximately 30 to 40 minutes. The process of allowing the solution to remain the abdomen is called the dwell time, which takes approximately four to six hours. A typical regimen consists of four exchanges a day each with a dwell time four to six hours. Hemodialysis utilizes a dialysis machine. The patient’s blood is sent to the machine through what is known as a vascular access. A vascular access is a means for blood to travel from the patient, to the machine, and back to the patient. An access is surgically constructed and consists of three different subtypes: primary AV fistula, synthetic
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AV graft (bridge graft), and a central venous catheter. A primary AV fistula is the preferred type of vascular access. A connection (fistula) is created between an artery (A) and a vein (V) usually in the lower arm under the skin. This allows the insertion of small needles into the fistula and the flow of blood to and from the machine. The second type of access is the synthetic AV graft, or bridge graft. This method is used when a patient’s arteries or veins are not able to create a fistula. In this situation, a plastic tube, graft, is used to construct a connection between the artery and vein. This tube is placed under the skin and is used similarly to an AV fistula. The third type of access is a central venous catheter. This route is performed in a more acute setting, when dialysis must be done immediately and the patient is devoid of a fistula, a graft or if a patient presents with nonfunctioning AV fistulas or grafts. Access is accomplished through placing a tube into a large vein in the neck. After the blood is collected from the body, it undergoes transformations by the dialysis machine. The machine allows contact between the patient’s blood and a solution called dialysate through a membrane, which is a special filter. On one side of the membrane is the dialysate and on the other is the patient’s blood. The toxic substances present in the blood shift from the blood, where it is in high concentration, to the dialysate, where it is in lower concentration or not present. This equalizes the concentration of the various substances. This method is more efficient than the natural kidneys and thus treatment is only needed intermittently. A typical regimen would include three to four hour sessions, three times a week. See Also: Kidney Failure and Dialysis; Kidney Diseases
(General).
Bibliography. Thomas Golper, “Continuous Renal Re-
placement Therapies: An Overview,” UpToDate, utdol. org (Cited September 2006); M. Manns, et al., “Continuous Renal Replacement Therapies: An Update,” American Journal of Kidney Disease (v.32/185, 1998); R.L. Mehta, “Continuous Renal Replacement Therapy in the Critically Ill Patient,” Kidney International (v.67:781, 2005,); P.M.
Palevsky, “Dialysis Modality and Dosing Strategy in Acute Renal Failure,” Semin Dial. (v.19/165, 2006).
Angela J. Garner, M.D. University of Missouri–Kansas City School of Medicine
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Diarrhea
Diarrhea This year, over one billion people around the world will suffer from diarrhea. The disease is particularly prevalent in the developing world, where a combination of poor sanitation practices and limited access to clean drinking water act together to spread many causative organisms. Diarrhea is often ignored as a routine irritation of the gastrointestinal system, but it can rapidly progress to cause profound and lifethreatening dehydration, especially in children. According to the World Health Organization (WHO), 500 million children worldwide have at least one episode of diarrhea every year. Two million of these children die, making it the second most common cause of childhood death after respiratory infections. In fact, 20 percent of all childhood deaths (under 5 years old) are caused by diarrhea-induced dehydration, making it a leading concern for global healthcare practitioners. Causes Diarrhea, defined as excessively liquid or frequent evacuation of feces, can be caused by numerous conditions. Infectious diseases make up the vast majority of causative factors, although diarrhea can also be caused by contaminated food, as a medication side effect (particularly antibiotics), as a symptom of colorectal cancer, and as a sign of hormonal abnormalities. Infectious organisms causing diarrhea include viruses (rotavirus being the most common), bacteria (e.g., E. coli), and parasites (e.g., Giardia). The gastrointestinal system, particularly the small and large intestines, are naturally populated by hundreds of different strains of nonharmful bacteria, many of which help with digestion. Infectious diarrhea can be caused either when a harmful, nonnative, biological agent colonizes the intestines or when one particular strain of native bacteria is favored over the others and takes over. This second pathway is exemplified by cases of bacterial overgrowth following the administration of antibiotics. The ingested antibiotics kill off most of the natural bacterial “flora” of the gut allowing a single disease causing variety to take over and proliferate. The principle pathway of infectious diarrhea however, occurs through the spread of dangerous organisms through the environment. Infected individuals without access to latrines or a safe sanitation system inadvertently contaminate their own supply of water,
spreading the disease to other members of their communities and creating a cycle of illness. Even with access to a clean water supply, organisms in improperly disposed of human waste can be spread to food by “vectors” like mosquitoes and other insects. Symptoms Diarrhea by itself is often ignored by patients and considered by many to be a temporary nuisance. However, it is important to distinguish associated symptoms that indicate a more serious condition. Fever, abdominal pain, blood or mucous in the stool, nausea, and vomiting are all reasons to seek urgent medical attention. If the nausea and vomiting are severe, the patient’s ability to maintain wellhydrated is at risk. Dehydration is the biggest danger to deal with during severe episodes of diarrhea. Signs and symptoms of dehydration include lethargy, weakness, sunken eyes, an increased heart rate (greater than 110 beats per minute for a 5-year-old), and decreased urine output. Chronic low-level diarrhea may also lead to malnutrition in children, who are unable to absorb the nutrients they need for normal growth and development. Treatment and Prevention The main treatment of diarrhea is rehydration therapy, either oral or intravenous. Oral fluids should be provided to the patient in a slow and steady manner, 15 ml per 15 minutes. In the 1960s, scientists invented oral rehydration salts (ORS), comprised of sugar, sodium, and other electrolytes, which are added to water to increase the intestinal absorption of the fluid. ORS saw their first widespread use in Bangladesh after the refugee crisis resulting from the 1971 India-Pakistan war. Since then, they have become widely available throughout the developing world and the therapy is thought to have saved millions of children’s lives. ORS is available for purchase in sachets manufactured under the supervision of the WHO and the United Nations Children’s Fund (UNICEF). Caregivers can also be taught the following simple home recipe to make a similar solution at home: one liter of water, one fist of sugar, and one pinch of salt. Oral rehydration should continue until the diarrhea runs its natural course. Children who cannot tolerate oral intake due to nausea and vomiting should be hospitalized for intravenous fluid therapy. Mothers should continue feeding their children during diarrhea episodes. The diet should include
Diesel Exhaust
breast milk for breastfeeding infants, or bananas, rice, and lentils for children used to solid food. The diet should be advanced slowly, and fluid hydration should be prioritized over solid foods. In rare cases, antibiotics may be required to treat certain strains of bacterial diarrhea. The decision to use antibiotics and the choice of agent should be left to a health practitioner, whose decision can be guided by an in-depth history of the illness and laboratory analysis (stool culture, stool analysis for ova and parasites, etc.). The majority of diarrhea episodes can be prevented via personal and public sanitation practices. Individuals should wash their hands after using the bathroom and before cooking and eating. Where municipal water is unavailable, water should be boiled or filtered. Municipal governments can prevent diarrhea by providing a clean supply of water and by building public latrines. Despite the consensus regarding diarrhea prevention and the ready availability of ORS, diarrhea remains a leading cause of child mortality in the developing world. Unhygienic bathroom practices and a limited access to clean water account for the continued prevalence. ORS is still used by caregivers only about 50 percent of the time to treat diarrhea. Diarrhea prevention should include increasing access to safe water, improved hygiene, and ORS promotion. The idea must be made clear to target populations that ORS is a treatment for dehydration, not diarrhea, and that it should be used as long as the diarrhea persists. In recent years, research has focused on developing a vaccine for rotavirus (two vaccines, rotateq and rotarix, are currently in clinical trials), which could prevent 500,000 child deaths and 2 million hospitalizations a year. SEE ALSO: Constipation; Digestive Diseases; Drinking
Water; E. Coli Infections; Giardia Infections; Infectious Diseases; Nausea and Vomiting; Travel Medicine; Traveler’s Health. BIBLIOGRAPHY. David A. Ahlquist and Michael Camil-
leri, “Diarrhea and Constipation,” in Harrison’s Principles of Internal Medicine, 15th ed. (McGraw-Hill Professional, 2001); Centers for Disease Control and Prevention, Richard E. Frye “Diarrhea,” eMedicine, www.emedicine.com, (Cited February 2006). The Rehydration Project; www.
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reydrate.org; World Health Organization; www.who.int/ topics/diarrhoea/en. Amit Chandra, MD, M.Sc. New York Hospital Queens
Diesel Exhaust At no point in human history have more humans been more exposed to air pollution than today. Rapid industrialization and urbanization are spreading this phenomenon across the globe affecting billions of people. The combustion of fossil fuels in many types of industrial and vehicular sources is responsible for the release of carbon monoxide, sulfur dioxide, nitrogen oxides, benzene, and particulate matter, among other emissions, into the environment. Most of these compounds have been shown to adversely affect human health. However, diesel vehicles and the diesel exhaust particles (DEP) they produce have been recognized as the most significant single contributors to the initiation and exacerbation of allergic airway disease and play a role in the progression of many other respiratory conditions as well. Diesel engines are preferred because of their energy efficiency and endurance, and with rising fuel prices, they constitute an ever-increasing proportion of vehicular systems, particularly trucks and buses. Unfortunately, even new, cleaner burning diesel engines emit more gaseous fumes and up to 100 times more particular matter than nondiesel engines. As a result, diesel vehicles are the largest single source of airborne particulates worldwide. Epidemiologic, human challenge, animal, and molecular studies have all shown a significant relationship between various types of air pollution and a myriad of respiratory and cardiovascular conditions. Gaseous (ozone and nitrogen dioxide) as well as particulate pollutants (DEP) have been shown to exacerbate asthma and chronic obstructive pulmonary disease, cause bronchitis, and lead to the slowing of children’s lung development. They are also associated with higher rates of heart attacks and hospitalizations for heart problems. In addition, dramatic increases in allergic rhinitis and asthma that affect tens of million of people have been linked with DEP produced by diesel vehicles.
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Dieting permanent. Some individuals are more susceptible to the effects of air pollution and diesel exhaust, but in all people, the effects are exacerbated and amplified by activities such as cigarette or cigar smoking. Due to the constant increase in the production of and exposure to DEP, the population health effects of diesel exhaust will only become more pronounced with time. Policy and legislation are needed to regulate DEP and prevent exposure. Further research is also needed to better define which type of DEP are most dangerous, who are most vulnerable to the effects, and how the consequences of DEP can best be treated. SEE ALSO: Pollution. Bibliography. D. Diaz-Sanchez and M. Riedl, “Diesel Ef-
Diesel engines constitute an ever-increasing proportion of vehicular systems, particularly in trucks and buses.
Diesel exhaust particles created by the combustion of diesel fuels consist of tiny grains of carbon dust covered in many different types of toxic chemicals and metals. The sizes of the particles vary and determine where they become trapped in the lungs. Depending on where they land, the particles then cause inflammation of both the upper and lower airways. The mechanism of this inflammation is thought to be by a combination of induction of oxidative stress and irritation causing the aggregation and activation of inflammatory cells and release of cytokines (mediators of inflammation). In patients suffering from allergic disease, the particles lead to increased allergic antibody production and the augmentation of allergic sensitization. Studies have found that children who live or play near freeways are more likely to have wheezing or severe asthma and are more likely to be hospitalized for asthma than children who do not. They are also more likely to suffer from atopy—the constellation of asthma, allergic dermatitis (eczema), and allergic rhinitis (hay fever). These effects have been confirmed in animal studies and other groups of people who are exposed to diesel pollutants as part of their jobs. It has been found that some of the symptoms of these conditions improve when the exposure to DEP pollutants is terminated. Other chronic effects of the pollution are
fects on Human Health: A Question of Stress?” American Journal of Physiology. Lung Cellular and Molecular Physiology (v.289, 2005); D. Diaz-Sanchez and M. Riedl, “Biology of Diesel Exhaust Effects on Respiratory Function,” Journal of Allergy and Clinical Immunology (v.115/2, 2005). Barry Pakes, M.D., M.P.H. University of Toronto
Dieting Diet is what people eat. The consumption of food is necessary to maintain life. A balanced diet is one that includes sufficient quantities foods with carbohydrates for energy, meats for proteins, calcium such as milk for bones, vegetables and fruits for minerals and vitamins. A balanced diet is one that supplies healthy foods in appropriate quantities. A casual, unplanned eating of whatever someone wants without regard to portions or to calorie expenditures is a diet that likely includes too much food or that is unbalanced can have negative consequences. One of these is that overeating can cause weight gains. While full weight is a sign of good health, it is possible for a person with an unbalanced diet to be at their full weight and still be less than the best of health. This can happened because an unbalanced diet can cause weight and poor health at the same time. An unbalanced diet can even allow the eater to be anemic or to suffer from of kinds of
conditions. One of these is weight gains and obesity that require the restoration of a diet that will eliminate the excess weight. This type of diet, a nutrition plan, to achieve goal such as a weight gain or weight loss are called dieting. Dieting is the ingesting of food in a regular planned manner to reach a particular weight goal. Most of the time the goal of dieting is weight loss; however, weight gain in the form of muscle is the usual goal of athletes. Weight lifters seeking to increase their muscle mass can be vigorous and still be overweight. Excess weight is a ration between body weight and body height. It is a relatively small range because some people are more muscular than are others. However, in the case of a body builder, the excess weight is muscle and not fat as in the case of those who are obese. Others who may seek to engage in a diet for gaining weight could include actors. In the case of actors playing a particular role, it may be necessary to gain a number of additional pounds in order to portray their character correctly. Weight gain diets are important to people who have become malnourished because they were stranded without food somewhere, were ill, or for some other reason. Diets to bulk up the body’s muscle mass are frequently used by athletes and soldiers. Most dieting is done to lose weight. People who have become overweight or obese can benefit by careful development of a weight loss program. Strictly speaking, people on a diet should see to replace fat with muscle. The conversion gives strength to the body as well as reserves of energy. It also reduces the strain on the heart and other systems such as the digestive system and its endocrine parts including the pancreas. There are a variety of eating disorders that are a very serious problem. Growing numbers of people have them. Most are cases of eating disorders, are a combination of emotional, physical, spiritual and cultural factors. Most of the people who have eating disorders are women, although men are afflicted as well. The most common eating disorders are anorexia nervosa, bulimia, and binge eating. Anorexia nervosa is an eating disorder in which the victim seeks to reduce his or her weight to much less than his or her ideal weight. The victim has an intense phobia that she or he will become fat. Bulimia victims experience recurring bouts of binge eating followed by purging. Depression is a common
Dieting
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psychological condition of bulimia victims. Their weight may be nearly normal, but the problem exists. Binge eaters eat large amounts of food off and on again. They often suffer from social emotions that make them feel out of control. Obesity and diabetes are common problems among binge eaters. Other ailments that present eating problems are diabetes, gluten intolerance, allergies to specific foods such as peanuts, and diets for specific acute illnesses such as cancer. In the case of diabetes the pancreas no longer makes enough insulin to process the sugars digestion has placed into the blood stream. Diabetes can be managed with a combination of diet, exercise, and medication. The reduction of sugar, saturated fats and alcohol, in the diet of diabetics is a desirable dietary goal. While diabetics can eat sugar, saturated fats, and drink alcohol if these are exchanged (using the American Diabetic Association’s food exchange plan), these are undesirable because they do not provide any nutrition other than sugar or fat which are either burned as calories or converted to fat. What is true for diabetics here is also true for all dieters who are seeking weight reduction. Diets for food allergies require the careful avoidance of foods that the body cannot tolerate or which may cause allergic reactions. An advance in the public education about these problems and in packaging labels on processed foods has reduced these threats somewhat. There are a multitude of diet plans. Many advertise themselves as the ideal or perfect diet plan. Other diet plans claim to be able to melt the fat away with the diets that is being sold to a potential dieter. However, given the great variety of people who are different ages with different body weights, body sizes, physical activities, and health problem, there is no one diet that fits all dieters. Adopting a diet plan is a matter of caveat emptor (“let the buyer beware”). A place to begin with dieting is with the Food Pyramid Guide. Whether viewed as six food groups, the pyramid rests upon carbohydrates. The carbohydrates that compose this group are breads, cereal grains such as wheat, corn, rice, millet, and other similar grains. The carbohydrate group can supply some roughage and a lot of calories. Much of its food value is converted into sugars to be used for energy. Excess amounts are converted into body fat unless combined with proteins to make muscle. These two groups include large quantities of proteins and fats. These are the building blocks for the body’s nutritional chemistry.
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The highest group in the Food Pyramid is the fats group. It is composed of fats from animal, some vegetables, and oils from nuts or other sources. This group is the smallest in size because it is meant to be consumed the least. The two blocks above the carbohydrate block are the vegetable group and the fruit group. These two groups are sometimes combined in other systems for grouping foods, but they supply different nutritional values. The vegetables supply carotene, a variety of vitamins and other nutritional units. The fruits supply vitamin C and other vitamins as well as other nutritional values. For the dieter, these two groups can be consumed in increased portions if the amount of carbohydrates is reduced because (especially the fruits) they supply sugars in limited quantities. The “trick” for the dieter is to not add sugar, creams, or other sauces that will turn the fresh or canned fruit into a calorie-rich desert. Above the vegetable and fruit group in the Food Pyramid are the smaller groups of the milk group (milk, cheese, and yogurt) and the meat group. Included in the meat group are animal meats, fish, poultry, eggs, nuts, and dried beans. There are a variety of fats found in foods. Those in meats such as choice cuts of beef or duck are rich in saturated fats. The fats are desirable from a culinary point of view because they flavor the meat. However, they are a health threat if consumed frequently over a long time because they contain saturated fats. These types of fats contain numerous hydrogen molecules in their formula. They are likely to contribute to artery blockage through artery plaque formation. They have also been linked to cancer. In small amounts, they are likely to be enjoyable, but they need to be restricted from the diet of most people unless they are engaged is hard physical activity such as hunting in the Artic or the activities of a young soldier in the field. Fats are needed by the body for important nutritional work. They should not be completely eliminated from most diets. Vitamins E and other vitamins are absorbed by the body’s fats for its metabolic use. The healthier fats to consume are the unsaturated fats. These can be found in olive oil and in other fats. They can also be used in salads, or in most cooking. The unsaturated fats do not have an abundance of hydrogen ions that can contribute to health problems. The diets of a great many people are not balanced. Instead of diets that are in appropriate portions recommended by the Food Pyramid, their diet is quite
distorted. The fat group is much larger than it should be. For many people fruit is occasional and vegetables are something rarely consumed. For many people, the only vegetables they consume are those found on pizzas that include peppers and onions. The unbalanced diet is likely to be very fattening and lacking nutrition. Excessive amounts of carbohydrates made from refined flour, fatty meats, and over consumption of beer is a formula for unwholesome weight gains. Many people rarely drink milk. The addition of calcium and vitamins to aid the body’s use of it is needed in most women and some men after menopause in order to prevent osteoporosis. Although it is not a food and is therefore not in the Food Pyramid, table salt is needed to keep the body’s use of water in balance. An insufficient supply of salt can contribute to dehydration. An excessive supply, however, can contribute to high blood pressure and to heart trouble. Most Americans get too much salt in their processed foods. Excessive amounts of salt cause retention of water and increases blood pressure. Good dieting will target the right amount of salt to consume along with other essential vitamins and minerals. The easiest diet to follow is to eat a balanced diet of the Food Pyramid Guide while exercising portion control. The portion sizes can be slowly reduced over a period of several weeks or months. The reduction will soon add up to the loss of pounds of fat. A pound of fat is equivalent is 3,500 calories. The reduction of calorie intake of just 350 calories per day will mean the loss of a pound in 10 days or in 20 days if the reduction in calories is cut in half. In addition to calorie reduction the development of systematic exercise is very valuable for aiding weight loss on a permanent basis. The practice of exercise converts fat calories to muscle. Exercise has a number of positive benefits and should accompany a diet plan. The burning of calories through exercise increases the strength of the body, the cardiovascular system, and the general psychology of the dieter. Few diet plans combine exercise with their numerous recipes. There are some organizations that have weight loss programs that do include an exercise plan. However, most diet plans, especially the fad diets, manipulate the balanced diet by adding more of some part of it or by eliminating some part of it. Some diets increase the amount of protein, or the amount of carbohydrates, or the amount of vegetables or fruits. Generally, diets increase some food and reduce or eliminate
Dieting
Many diet plans manipulate the balanced diet by increasing some food types and reducing or eliminating other food types.
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treats in the diet plan. This frees the dieter from the risk of identifying the desert with a reward and makes it just a part of the diet. In the world today, a part of the world is dieting to lose weight gained from lack of exercise and usually excessively large portions of food. People in the urban settings of the Northern Hemisphere are living in a built environment that does not favor exercise. Their environment also does not favor wise eating because of the number of high calories fast foods that are easily available. The combination of cheap carbohydrates and fats in “supersized” portions combined with a lack of exercise is contributing to obesity which has become a major health hazard for millions. Sensible diets combined with sensible exercise are vital to weight loss on a permanent basis. SEE ALSO: Anorexia Nervosa; Bulimia; Diabetes; Nutri-
others. The food that is increased may be fruit so that the dieter eats more grape fruit and no carbohydrates. Or the diet may eliminate carbohydrates and increase the amount of meat and vegetables. Other diets completely eliminate food and put the dieter on a strict water-alone diet. This can result in the loss of several pounds in a few days as the body eliminates feces and some fat. However, this type of diet carries the risk of health damage. It also is likely to result in frustration after the weight loss plateaus. Some diets increase or reduce the supplements of vitamins. Others recommend more salt or more calcium or something else. These diets can accomplish some weight loss. However, they can also be damaging to health. Another key element for any diet besides exercise is discipline. It takes systematic action to keep on a diet. Probably any diet plan will result in some weight loss; however, to reach the target weight requires discipline. The discipline needed to stay with a diet plan can be psychologically taxing or just plain boring. Many people fail to keep their diet plan with discouraging psychological results. The feeling of being a failure and that it does not matter what is attempted the weight will not come off is a common experience. A useful tactic for staying with a diet plan is to set small target goals. It, however, is important to set rewards that are something other than food. It does little good to lose a pound and then to indulge in a triple banana split. A better tactic is to include small
tion; Obesity.
Bibliography. Elliot D. Abravanel and Elizabeth King
Morrison, Dr. Abravanel’s Body Type Diet and Lifetime Nutrition Plan (Bantam Books, 1999); T. Colin Campbell and Thomas M. Campbell, The China Study: The Most Comprehensive Study of Nutrition Ever Conducted and the Startling Implications for Diet, Weight Loss and LongTerm Health (BenBella Books, 2005); S. Mikielle Chatman, Long Term Weight Reduction Management: The Advance Plan (Fat Chance Publications. 1992); Greg Guest, Globalization, Health, and the Environment: An Integrated Perspective (AltaMira Press, 2005); Jean A. T. Pennington and Judith S. Douglass, Bowes and Church’s Food Values of Portions Commonly Used (Lippincott Williams & Wilkins, 2004); James M. Rippe, Weight Watchers Weight Loss That Lasts: Break Through the 10 Big Diet Myths (Wiley, 2005); John Robbins and Dean Ornish, Food Revolution: How Your Diet Can Help Save Your Life and Our World (Red Wheel/Weiser, 2001); Shmayre Primack, Sure-Fire Weight Reduction and Longevity Program: Solutions for Life (Judlinsa Nutrition, LLC, 2007); Sue Rodwell Williams, Essentials of Nutrition and Diet Therapy (Times Mirror/Mosby College Publishing, 2000); Robert O. Young and Shelley Redford, The pH Miracle for Weight Loss: Balance Your Body Chemistry, Achieve Your Ideal Weight (Grand Central Publishing, 2006). Andrew J. Waskey Dalton State College
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Digestive Diseases (General)
Digestive Diseases (General) The topic of digestive disease encompasses a large range of disorders and processes. It includes all disorders that can produce dysfunction of digestion. Multiple organs may be effected and the disease can be life threatening, as in certain types of cancers, or fairly benign, such as in viral infections. Today, over 60 million people in the United States have a digestive disease at some point annually. Digestive disease accounted for over 230,000 deaths in 2002 and was responsible for 9 percent of all hospitalizations in that year. To grasp a general understanding of digestive disease processes, while not going into extreme depth about individual illnesses, it is easiest to cover the function of the digestive tract, some of the more common symptoms, and the causes of these symptoms. Function of the Digestive Tract The digestive tract serves two major functions: the absorption of nutrients and the elimination of waste. Each anatomical section of the tract is designed to process the food we eat and prepare it for either energy the body can use or disposal. Recapping the movement of food through the digestive tract is essential in understanding dysfunction of this organ system. First, the mouth houses certain enzymes in saliva that begin to break down food and then the food is pushed through the esophagus and into the stomach. It is in the stomach where food is further broken down by the highly acidic stomach contents. Next, digestion continues in the small intestine where the majority of nutrients are absorbed for the body’s use. It is also in the small intestine where substances from the gallbladder, such as bile, and substances from the pancreas are added. Bile helps the absorption of digested fats. Finally, once what is left of the food is in the large intestine, water is pulled out of the stool, and thus the stool becomes more concentrated. Bacteria are also present in the large intestine and help to further ferment and break down the left over food particles. Stool is then expelled through the colon. The motility of digestion is largely caused by involuntary stimulation from our nervous systems. Abdominal pain Abdominal pain is any pain that is felt between the chest and the groin. The causes of this pain are nearly endless and encompass problems associated
with any digestive organ (those listed above), the abdominal wall, the spine, female reproductive organs, or organs of the urinary tract, such as the kidneys or bladder. Different types of abdominal pain result depending on what organ or body part is affected. For example, when an internal organ causes the pain, a dull vague pain usually results. However, if the cause of the pain is more externalized, it commonly results in a sharper, more precise or clear-cut pain. Abdominal pain can also be broken down into acute pain, usually occurring suddenly and needing emergent intervention, and chronic pain, which is pain that occurs over a long period of time. The reason for these differences has to do with the distribution of different branches of our nervous system. Due to the numerous causes of abdominal pain, just a few of the causes will be mentioned. These different causes will be broken down into serious illnesses causing abdominal pain and then followed by other common diseases. The more serious causes of abdominal pain involve problems such as appendicitis, bowel perforation, and dissecting aorta aneurysm. The appendix is a blindended tube connected to the beginning of the large intestine. The appendix can become inflamed due to a process that is not entirely known. When this occurs, extreme pain is felt at the right lower side of the abdomen. This pain becomes worse when pressing on the skin over this area. If the appendix ruptures due to this inflammation, peritonitis (inflammation of the cavity surrounding the abdominal organs) can ensue. Bowel perforation can also result in a life-threatening peritonitis. A dissecting aortic aneurysm presents as tearing pain either felt in the abdomen or chest. This event involves the separation of layers of the aortic wall (the largest artery in the body) and can lead to rupture causing a massive amount of internal bleeding. These just account for a few of the more serious causes of abdominal pain. Others include gallstone disease, pancreatitis, peptic ulcer disease, diverticulitis, inflammatory bowel disease, and so forth. Other common causes of abdominal pain include problems such as kidney stones and disorders associated with the female reproductive tract. Kidney stones occur more commonly in men than in women and present with severe, spasm-like pain typically. Kidney stones usually result after a long period of time where the urine has been concentrated leaving
crystals or some other process. The causes of kidney stones depend largely on what substance forms the stone. Overall, drinking plenty of fluids will help prevent kidney stones from forming. Women often experience abdominal pain during menstruation or other processes involving the reproductive tract, such as a ruptured cyst of the ovary. The pain felt from a ruptured cyst is sharp, intense, and usually doesn’t last long. The abdominal pain felt during menstruation is often described as cramping and is caused by the release of hormones resulting in contraction of the uterus. Nausea and Vomiting Nausea and vomiting account for two symptoms that commonly occur in patients of all age groups. Although, these are actually two separate symptoms, they often occur together, with nausea preceding vomiting. Nausea is the urge in the need to vomit, but not necessarily regurgitating any stomach contents. Vomiting, on the other hand, is the actual process of pushing stomach contents up through the esophagus and out the mouth. Causes of these two symptoms in all age groups include medication, gastrointestinal obstruction, infections of the digestive tract, pregnancy, motion sickness, central nervous system diseases, alcoholism, and so forth. Some causes of nausea and vomiting in infants include pyloric stenosis (obstruction in the outlet of the stomach), milk allergy, gastrointestinal obstruction, and reflux (commonly known as “spitting up”). While acute or brief episodes of nausea and vomiting may just be a discomfort, prolonged vomiting can lead to severe dehydration or growth restriction in an infant. Also, prolonged or excessive vomiting in the adult can lead to aggravation of the esophagus, gastroesophageal reflux disease (GERD), and eventually may progress to esophageal cancer. Persistent vomiting is commonly associated with alcohol abuse. Dehydration caused from vomiting, when severe, is a life-threatening emergency and requires immediate medical attention to re-hydrate that individual. Hematemesis, the vomiting up of blood, is another serious condition that can occur and raises immediate concern. Causes of hematemesis are wide ranging, including ingestion of toxic substances and peptic ulcer disease. Like abdominal pain, nausea and vomiting combine with other symptoms of many disorders of the digestive tract.
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Diarrhea Diarrhea is defined as frequent, watery, loose stools and is chronic when these types of stools last longer than four weeks. Diarrhea can either be described as an increase in frequency, urgency, or in fecal continence. A wide range of illnesses can cause diarrhea, like most digestive tract problems. The leading cause of diarrhea is viral gastroenteritis, a viral infection of the digestive tract. This infection usually lasts only a few days and is commonly referred to as the “stomach flu”. Other common causes of diarrhea include malabsorption disorders (discussed later), inflammatory bowel disease, irritable bowel syndrome, and celiac disease. Like vomiting, dehydration is a major and usually the most severe consequence of diarrhea. Dehydration often has a faster onset in young children and is more concerning. As with vomiting, blood in diarrhea is also a reason for concern. Dysentery, bloody diarrhea usually caused by a bacterial infection, is associated with infections with certain types of E. coli, shigella, and salmonella. With excessive blood loss in stool, a patient must be continually reevaluated for anemia, a lowered number of red blood cells. Food poisoning is also a common cause of diarrhea that usually resolves in a 24- to 48-hour period. Food poisoning results from drinking water or eating foods containing bacteria or parasites. Often, people can have short-lived diarrhea because of a change in diet or digestive tract irritation from certain foods. In diarrhea, as with vomiting, it is important to maintain adequate fluid intake to ensure proper hydration. Constipation Constipation can either be defined as infrequent stools, straining with defecation, passage of hard stools, or the sense of incomplete evacuation of stool. A more exact definition states that constipation is a lack of a bowel movement for greater than three days for an adult. Some infants may go seven days without having a bowel movement. Commonly, constipation is caused by a low-fiber diet, lack of physical activity, not drinking enough water, or waiting to defecate when having the urge to do so. Constipation, as with the other digestive disease symptoms mentioned previously, is serious if occurring in certain situations. For example, a recently born infant that hasn’t passed a stool can have a congenital abnormality in their digestive tract that must be corrected rapidly or it may
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lead to permanent damage. Also, sudden loss of blood in the stool, hematochezia, in older people can be the first sign of a colon polyp or even colon cancer. Malabsorption Malabsorption is the difficulty of absorbing and digesting nutrients. As with the previously mentioned types of digestive disease symptoms, the causes of malabsorption are numerous. Malabsorption usually has to do with impairment of the absorption of specific sugars, fats, proteins, and vitamins; or, failed uptake of all substances in general. The causes of this problem can be from an infection, congenital, autoimmune, or caused by another illness. Autoimmune diseases are when the body’s own immune system recognizes a normal part as being foreign and attacks that specific body part. Some other problems associated with malabsorption include diarrhea, growth restriction, bloating, cramping, distended abdomen, frequent stools, malodorous stools, and muscle wasting. Prolonged malabsorption causes malnutrition and/or vitamin deficiencies, which lead to many more medical problems and issues. One of the most common causes of malabsorption in children is cystic fibrosis. This congenital disease primarily affects the respiratory system and causes recurrent bacterial infections and mucous buildup. The malabsorption component of this disease has to do with pancreatic insufficiency. This insufficiency leads malabsorption of fat and protein and eventually leading to difficult weight gain and malnutrition. Another common disease process that leads to impaired absorption is lactose intolerance (also known as milk intolerance). This illness is secondary to a deficiency in the enzyme lactase, which is found in the small intestine. Lactase, when present, breaks down lactose, a sugar found in milk and dairy products. This deficiency usually occurs after the age of five and leads to a deficiency in vitamin D, calcium, and protein, requiring supplementation with these substances. If a person who is lactase deficient consumes dairy products, they can have symptoms such as abdominal bloating, diarrhea, flatulence, and nausea. Overall, lactose intolerance is not a dangerous disorder. Other diseases causing malabsorption include Whipple disease, celiac disease, abetalipoproteinemia, biliary atresia, and chronic pancreatitis.
Infections with certain parasites can also lead to malabsorption and those symptoms that occur with it. For example, the parasite Diphyllobothrium latum, the fish tapeworm, can lead to an infestation that inhibits the absorption of vitamin B12. Deficiency of vitamin B12 leads to a certain type of anemia. Also, Giardia lamblia is another parasite can be acquired by drinking contaminated spring water from streams or lakes and infects the small intestine. Giardia causes loss of appetite, vomiting, diarrhea, flatulence, and cramping, which all play a role in not absorbing the proper amount of nutrition. Whether it is from a parasite, or from other causes, specific supplements are needed to replace appropriate nutrients that are lost in malabsorption. Gastroesophageal Reflux Disease GERD is a common condition in which food or liquids travels from the stomach and back up through the esophagus. The acidity of the stomach contributes to the symptoms felt from this disorder. Stomach acid helps break down and digest food and if this acid is refluxed back into the esophagus it can cause the feeling of “heartburn”. Often, GERD occurs without the presence of any symptoms. This likely occurs at some point during every person’s life. A defect in the sphincter of the lower esophagus, the valve that helps prevent reflux from the stomach, often contributes to GERD. Some of the symptoms associated with reflux besides heartburn, include vomiting blood/food, nausea, belching, hoarseness, sore throat, cough, and a sour taste in the mouth. Certain foods and activities can worsen GERD symptoms. For example, foods such as chocolate, caffeine, spicy foods, and peppermint can exacerbate these symptoms. Also, other contributors include being overweight, lying down shortly after a meal, taking medication without water, smoking tobacco, and drinking alcohol. It is important to avoid these foods and activities as part of the treatment of GERD. One of the worst consequences of prolonged gastroesophageal reflux is the change in the type of cell that lines the esophagus. Initially, this change in cell type has no meaningful consequences; however, if left unnoticed, a person may develop esophageal cancer that is life threatening. Overall, GERD is very easily managed on the right medications and if treated early.
Diptheria
Digestive diseases are common in every country and can range from very severe to just an overnight or one-time event. It is important to have severe illness of the digestive tract evaluated promptly and by the right healthcare worker. Also, it is important to try and prevent the less serious diseases or problems from progressing into something worse. These digestive issues will continue to be a large part of medical illnesses and will need to be evaluated earlier in order to put less strain on healthcare. SEE ALSO: Appendicitis; Constipation; Cystic Fibrosis; Di-
arrhea; Gastroesophageal Reflux/Hiatal Hernia; Inflammatory Bowel Disease; Kidney Stones; Nausea and Vomiting; Peptic Ulcer Disease. BIBLIOGRAPHY. Thomas E. Andreoli, et al., Cecil Essen-
tials of Medicine (Saunders, 2004); Dennis L. Kasper, Eugene Braunwald, Harrison’s: Principles of Internal Medicine (McGraw-Hill 2005); Medline Plus, “Medline Encyclopedia,” http://www.nlm.nih.gov/medlineplus (cited March 2005) National Digestive Disease Information Clearinghouse, “Digestive Disease Statistics,” http://digestive.niddk. nih.gov (cited December 2005). Angela J. Garner, M.D. University of Missouri–Kansas City School of Medicine
Diphtheria Diphtheria is a very contagious and potentially lifethreatening bacterial disease that primarily affects the nasal passages, throat, and lungs. In some instances, the infection can spread or attack the skin, heart, and nervous system. Immunization efforts have been able to keep this bacterial infection out of most of the developed world and much of the developing world. However, there has been a global resurgence of diphtheria due to poorly managed vaccination programs, a lack of funding, and other preventative measures. Regionally, former Soviet Republics have seen a disproportionate increase of diphtheria infection. This is proposed to be from inadequate and nonexistent vaccine programs throughout the 1990s.
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Diphtheria is caused by Corynebacterium diphtheriae bacteria and can be easily spread through mucous secretions by coughing or sneezing of infected persons. Cramped living conditions, poorly planned congested urban neighborhoods, lack of proper sanitation, lack of vaccination plans, and poor knowledge of the disease aid in its spread throughout the world. According to the Centers for Disease and Control (CDC), currently about 10,000 new cases are reported each year with a previous spike of some 60,000 cases reported annually during the mid-1990s. In a CDC report, it was noted that t�������������������������������������������������������� he overall case-fatality rate for diphtheria is five to 10 percent, with higher death rates (up to 20 percent) among persons younger than 5 and older than 40 years of age. Types of Diphtheria There are toxigenic and nontoxigenic strains of Corynebacterium diphtheriae that can cause disease. Strains that produce toxins cause an inflammation of the heart (myocarditis) and nerve inflammation and disease (neuritis and neuropathy). These toxins can also cause low platelet counts (thrombocytopenia) and protein in the urine (proteinuria). Where myo���� carditis experiences an early onset, it is often fatal. Neuritis often affects motor nerves and can resolve with possible paralysis of the soft palate, eye muscles, limbs, and diaphragm. Secondary pneumonia and respiratory failure are known to occur from paralysis of the diaphragm. Other complications are otitis media and respiratory insufficiency from airway obstruction. This is most common in infected infants. When the infection manifests in nonimmunized persons, the bacteria releases the toxin and subsequent damage occurs in the body. Toxigenic strains are more often associated with severe or fatal illness. This is mainly in the form of respiratory or other mucosal surface infections. Diagnosis and treatment Diphtheria is best diagnosed clinically by identifying a gray membrane covering the throat and possibly inflamed tonsils and with an accompanying sore throat, fever and malaise. Any mucosal membrane can be infected (i.e., various nasopharyngeal, coetaneous, genital, and ocular). The diagnosis can also be confirmed with a throat culture if the laboratory capabilities
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exist. Corynebacterium diphtheriae is an aerobic gram-positive bacillus. For those who are not vaccinated and contract the disease, active immunization and strong antibiotics are the best course of treatment. For those who are infected and are exposed to diphtheria, they must receive a booster of diphtheria toxoid plus active immunization and strong antibiotics. The most common vaccination program is the diphtheria toxoid mixed with tetanus and or pertussis vaccines. Vaccination provides the best preventative treatment. Epidemic in Post–Soviet Countries The fall of the Soviet Union in 1991 engendered the Newly Independent States (NIS) and Baltic States with a fragmented health infrastructure and delays in implementing control measures. During the early 1990s, diphtheria was at epidemic levels in these states. This rapid increase in new cases of diphtheria was the first comprehensive epidemic in industrialized countries in over three decades. Much research in the literature conclude that the main contributing factors to this epidemic include a large population of susceptible adults and children, decreased childhood immunization programs, loss of a vaccination and preventative programs, poor socioeconomic conditions, deteriorated health infrastructure, and high population movement and migration. A large-scale and well-coordinated international effort met these challenges in the mid1990s with ��������������������������������������� aggressive control strategies and highyield outcomes. The legacy of this epidemic includes a reexamination of the global diphtheria control strategy, new laboratory techniques for diphtheria diagnosis and analysis, and a model for future public health emergencies in the successful collaboration of multiple international partners. Diphtheria remains a global health threat and the most recent epidemic in post–Soviet nations is a stark reminder of diphtheria’s potency. SEE ALSO: Adolescent Health; Adult Immunization; Cen-
ter for Disease and Control and Prevention (CDC); Childhood Immunization; Epidemic; Immunization/Vaccination; National Immunization Program (NIP). Bibliography. W. Atkinson, Epidemiology and Preven-
tion of Vaccine-Preventable Diseases. eds. 9th ed. (Public
Health Foundation, 2006); S. ���������������������������� Dittmann, M. Wharton and C. Vitek, Successful Control of Epidemic Diphtheria in the States of the Former Union of Soviet Socialist Republics: Lessons Learned, The Journal of Infectious Diseases (v.181/ Suppl 1, 2000); Stanly A Plotkin,Vaccines, 4th ed. (Saunders, 2003); World Health Organization (WHO), Immunizations, Vaccines and Biologicals, http://www.who.int/vaccines-surveillance (cited July 2006). John Michael Quinn V, MPH University of Illinois at Chicago
Disasters and Emergency Preparedness The common understanding of a “disaster” assumes that some spectacular event has occurred in a particular time and space. Such a perspective is limiting because some disasters, such as famines and epidemics, or creeping environmental disasters (e.g., desertification, water depletion of lakes) involve diffuse processes occurring over long durations. For this reason, it is best to think of a disaster in more general terms, as the convergence of sociopolitical and biophysical processes that results in an event in which there is severe physical damages and a disruption of the routine functioning of a community and/or ecosystem. By this definition, all disasters have human and material dimensions. It is particularly important to recognize this dual nature of disasters when considering how certain populations are more vulnerable than others to the effects of a disaster. For example, analyses of the impacts of Hurricane Katrina on New Orleans, Louisiana, in 2005, and the heat wave on Chicago, Illinois, in 1995, reveal how certain marginalized communities were more heavily impacted than other groups because of the way the cities were physically and socially segregated by race and income. Similarly, analyses of the 1984 Union Carbide chemical leak disaster in Bhopal, India, reveal how those lowest on the economic scale experienced the highest fatality rate because the shanty town conditions in which these victims resided led to greater and more direct chemical exposures.
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The Disaster Management Cycle The disaster management cycle describes a continuum of interlinked activities aimed at the reduction of risk before disaster onset and the pursuit of postdisaster recovery efforts. It is a cycle because what is learned during the recovery phase can be used to produce more effective risk-reduction activities for similar disasters that may occur in the future. The disaster management cycle consists of five parts. The recovery phase consists of 1.) response, 2.) rehabilitation, and 3.) reconstruction activities, while the reduction phase involves 4.) mitigation and 5.) emergency preparedness. Mitigation and emergency preparedness are complementary. The former involves those measures intended to reduce the vulnerability of places to disaster and to reduce the disaster impacts. Mitigation includes such things as the enforcement of building and land use regulations, the control of hazardous substances, and the implementation of safeguards to protect critical infrastructure elements such as power supplies and communications networks. The overall objective of emergency preparedness is to ensure that appropriate systems, procedures, and resources are in place to provide prompt and effective assistance to disaster victims. In essence, it involves those measures that enable organizations, communities, and individuals to rapidly and effectively respond to disasters. The emergency preparedness component includes the formulation of disaster plans; the special provision for emergency action (i.e., evacuation plans, temporary safety shelters, the mobilization of relief
agencies, emergency warning, and communication systems); and public education/awareness programs and training programs (i.e., practice exercises and drills). Although related to other stages of the disaster management cycle, preparedness measures tend to be more strongly oriented toward action by organizations such as police and fire departments, utility companies, hospitals, social service agencies, military, mass media, and nongovernmental agencies. There are many disruptive elements associated with disasters, including property damage, loss of livelihood, interruption of essential services, economic losses, physical and mental health impacts. Notwithstanding their dual nature, disasters may be classified as natural or technological depending on the nature of the particular causative agent. Examples of the former include earthquakes, tornadoes, hurricanes, and floods, while the latter includes chemical spills, industrial explosions, and nuclear accidents.
The objective of emergency preparedness is to ensure that appropriate resources are in place to provide effective assistance.
Technological Disasters On a macroscale, globalization has contributed to issues of vulnerability and marginalization in the context of technological disasters and has played a role in the unequal distribution of risks and hazards around the world. For instance, in the aftermath of the Bhopal tragedy, it was found that Union Carbide’s sister companies in developed countries had more stringent safety measures and occupational health practices in place to protect workers and prevent industrial accidents. The significance of such differences is that the potential for industrial disasters may be higher in the developing world relative to the developed world. Furthermore, multinational corporations may choose to locate some of their companies in impoverished areas because it is less costly (because they will not have to abide by stringent environmental and health regulations and standards). Those living in such areas are more likely to accept these risk-producing industries because they have no other options to consider in regard to economic gains. This is also true for the location of toxic waste sites and other activities that have a high disaster potential. For example, research has found that toxic waste sites in the United States are more likely to be found near poor African-American neighborhoods, thus increasing the disaster potential for this social group.
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In the aftermath of a technological disaster such as a chemical contamination event, community members sometimes suffer for decades on a number of fronts (i.e., emotionally, mentally, physically, socially, financially, etc.). Further, low levels of contaminants may sometimes remain in the environment long after the disaster onset, thereby contributing to the experience of chronic, debilitating disease and illness—in effect leaving behind a toxic legacy. Such problems were experienced, for example, by survivors of the nuclear disaster in Chernobyl (1986), and those living in the contaminated Love Canal, New York, site (which brought to the fore the issue of toxic waste in 1978) as well as those residing near the many abandoned industrial sites (known as brownfields) throughout the world. Technological disasters of this type may have severe mental health impacts often described in terms of the syndrome of post-traumatic stress disorder (PTSD). Symptoms of PTSD include nightmares, emotional numbing, withdrawal, insomnia, and irritability. These may be exacerbated by the social conditions that emerge in the posttechnological disaster milieu. Unlike natural disasters where the physical harm to the body is immediately apparent (e.g., a broken arm caused by falling off a tree), with a technological disaster such as a nuclear or chemical contamination event, the harm is much more insidious. For example, exposure to chemical contaminants may lead to feelings of dread and anxiety because of the uncertainty caused by the lag time between exposure and the development of the disease (e.g., cancer). Moreover, because a technological disaster is often attributed to a human error, victims in the disaster aftermath are often involved in stressful legal cases involving compensation, blame, and the search for those responsible. These circumstances lead to a corrosive community that is characterized by a lack of trust, suspicion, and fragmentation which also contribute to the mental health impacts of a technological disaster. On the other hand, in the face of natural disasters, a sense of community cohesiveness emerges with the common rationalization that the disaster was merely an unfortunate and nonpreventable act of nature. In these circumstances, a therapeutic community may emerge in which people band together in a spirit of goodwill to respond to the natural disaster. Both types of social responses should be considered in developing appropriate emergency preparedness plans.
Natural Disasters Popular accounts of natural disasters tend to “naturalize” the disaster. Unlike the case of human-made disasters where failures in technology represent a loss of control over systems we have created, natural disasters are often viewed as the inevitable lack of control over natural agents. Consequently, the social and political underpinnings of the “natural” disaster are not considered as part of emergency planning. The impacts of a natural disaster, however, are the result of the interplay of human activities related to land use, living standards, and public policies in addition to the natural agent itself. For example, in the case of the Chicago heat wave, it was found that intense heat was deadly only in combination with particular social and physical circumstances in which socially isolated members of the black community (such as elderly individuals who were poor and lived alone) were afraid, or unable to, venture out in dangerous neighborhoods to seek air conditioning, nor could they leave their doors and windows open for fear of crime. The city’s emergency plan did not consider this. Similarly, Hurricane Katrina revealed the inadequacy of the emergency plans in New Orleans by emphasizing evacuation by car, neglecting those who simply could not afford this luxury and as a result were stranded in the flood conditions. Ideally, the development of effective and efficient emergency preparedness strategies should incorporate the lessons learned from the mistakes made in response to similar disasters of the past. In a positive light, this did, in fact, occur in 1999 when Chicago experienced another severe heat wave. In this instance, issues related to vulnerable and marginalized groups were more effectively addressed. Emergency Preparedness Myths Preparedness measures defined in many emergency management plans are often inadequate. These deficiencies may be partially addressed by focusing more attention on tighter coordination among organizations who work with vulnerable groups (such as social service organizations, police, and nongovernmental agencies). Furthermore, attention should focus on measures to ensure clearer communication among people who need information; and greater cooperation among individuals and organizations, particularly between the military and civilian groups.
Second, in drafting emergency preparedness measures, disaster managers should take into consideration the myths and realities of disasters. The Pan American Health Organization (2000) lists several of these. For example, it is a myth that medical volunteers with any kind of medical background are needed at times of emergencies because it is the local population who almost always covers the immediate lifesaving needs. As such, only those medical personnel with those specialized skills that are not available in the affected area may be needed. Similarly, it is a myth that any kind of international assistance is needed, and that it is needed immediately. The reality is that a hasty response that is not based on an impartial evaluation only contributes to the chaos. It is, therefore, better to wait until the genuine needs have been assessed because in actuality, most needs are met by the victims themselves and their local agencies, not by foreign intervenors. It is popularly thought that disasters bring out the worst in human behavior, such as looting and rioting, but in reality, this is not always true. Although there may be some isolated cases of antisocial behavior (that is often emphasized in media accounts, perhaps for the dramatic effect, as was the case in the Hurricane Katrina coverage), for the most part, people respond spontaneously and generously during disasters. It is also commonly thought that the affected population will be too shocked and helpless to take responsibility for their own survival. However, studies have shown that many find new strength during an emergency, as seen for example, by the thousands of volunteers who spontaneously united to sift through the rubble in search of victims in the aftermath of the 1985 earthquake in Mexico City. It is also a myth that disasters are random killers, because as we have discussed above, the fact of the matter is that the impact of disasters are felt most by vulnerable groups such as the poor, the elderly, women, and children. Emergency preparedness may be enhanced by incorporating elements of vulnerability analysis. This includes an integrated multidisciplinary approach that seeks to understand those circumstances that put people and places at risk based on an analysis of the complex interactions between social, natural, and engineered systems. By providing information about the sectors at risk such as the physical (e.g., buildings, infrastructure, critical facilities), the social (e.g., vulnerable groups, livelihoods, local institutions, poverty),
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and the economic (i.e., direct and indirect financial losses) as well as by focusing on the kind of risk (e.g., damage to public infrastructure, housing, or casualties), a more integrated approach to emergency preparedness may be developed—one that is sensitive to the totalizing nature of all disasters. As illustrated by our discussion of technological and natural disasters, the fact that all types of disasters have a sociopolitical basis should be taken more seriously in emergency preparedness planning. This could be accomplished, for example, by taking into account grassroots input and local knowledge into emergency preparedness planning by collaborating with lay participants, community members and environmental justice activists on specifically action-oriented strategies. Lay–expert collaborations have been found to be a necessary component for more successful regulatory processes and policies in general. This would also hold true for the development of sound emergency preparedness plans and measures because the success and failure of such efforts will ultimately depend on citizen understanding and public buy-in. SEE ALSO: Environmental Health; Pan American Health
Organization (PAHO); Post-Traumatic Stress Disorder.
Bibliography. W. Nick Carter, Disaster Management: A
Disaster Manager’s Handbook (Asian Development Bank, 1991); Lee Clarke, Mission Improbable: Using Fantasy Documents to Tame Disasters (University of Chicago Press, 1999); Eric Klinenberg, A Social Autopsy of Disaster in Chicago: Heat Wave (University of Chicago Press, 2003); Pan American Health Organization, Natural Disasters: Protecting the Public’s Health (Pan American Health Organization, 2000). S. Harris Ali, Ph.D. Ann Novogradec, Ph.D. York University, Toronto
Disease and Poverty There is a direct correlation between poverty and disease. Poverty creates a cyclical relationship with disease for vulnerable groups and countries in that poverty causes people and countries to be hopeless, unaccountable, and irresponsible and these in turn
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create the conditions for disease to fester and spread. Thus, from a human behavior perspective, many of the diseases that are causing so much suffering in our world today could be prevented if individuals and governments would be responsible in their behavior. While this may come as a harsh indictment, an analysis of the causes and spread of some of the deadliest diseases will reveal that they could be contained if governments and individuals acted in ways that would minimize the outbreak and spread of some diseases. However, governments and people in poor countries have not acted to curb diseases because they do not have the resources with which to act in the first place. Therein lies the dilemma and hopelessness of disease control in poor countries. The deadliest diseases are found predominantly in the poorest regions of the world. The poorest people in these places are the most vulnerable, as well. Sub-Saharan Africa and southeast Asia are the two regions in the world where the human cost of disease is greatest and poverty levels are highest. Indeed, sub-Saharan Africa is the only region in the world now where poverty levels keep rising and more people are afflicted with killer diseases every year. In a feature article in Time in March 2005, Jeffrey Sachs drew attention to the persistence of poverty in Africa by stating that “while the economic boom in East Asia has helped reduce the proportion of the extreme poor in that region from 58 percent in 1981 to 15 percent in 2001, and in south Asia from 52 percent to 31 percent, the situation is deeply entrenched in Africa, where almost half of the continent’s population lives in extreme poverty—a proportion that has actually grown worse over the past two decades as the rest of the world has grown more prosperous.” The magnitude of poverty in Africa can be appreciated from the Live 8 Concerts that Bob Geldof, in association with other activist musicians, organized in different cities across the globe to draw the attention of G-8 leaders meeting in Scotland in July 2005 about poverty in Africa. Geldof organized a similar concert in 1985 to raise money to fight African poverty in Ethiopia. Twenty years later, the situation appears to have worsened. One of the clearest expressions of the links between disease and poverty is the HIV/AIDS pandemic. HIV/AIDS pandemic In the 1980s, when doctors and scientists were grappling with the cause and mode of spread of AIDS, a
staff writer for Time magazine wrote that more than 2 million Africans were infected with the HIV virus. Less than 20 years later, in 2002, the World Health Organization (WHO) estimated that there were 29.4 million Africans living with HIV. In 2005, there were an estimated 35 million people worldwide living with HIV/AIDS and the greatest number lived in sub-Saharan Africa. Sue Sprenkle of the Southern Baptist Convention International Mission Board wrote in 2001 that “only 10 percent of the world’s people live in Africa, yet it is home to 70 percent to the world’s HIV-infected people.” Countries in southern Africa are the worst hit. According to estimates, one in every four people in Botswana is HIV positive; it is one in three in Zimbabwe. South Africa is perhaps the worst case in the world. In 1986, HIV prevalence in adults in that country accounted for only about one percent; by the end of 2001, it had risen to about 39 percent. Not surprisingly, of the 3.1 million people worldwide who died of AIDS in 2002, 2.4 million were living in sub-Saharan Africa. For South Africa alone, WHO has estimated that for the age group 15–34 years living with AIDS, 1.3 million would die between 2000 and 2005, and a further 1.7 million the next five years. The United Nations projects that there will be 40 million AIDS orphans in Africa by 2010. Some of these orphans would be carriers of the AIDS virus. The problem of HIV/AIDS in Africa thus reflects the deepest levels of misery and hopelessness. When we contrast the prevalence of HIV/AIDS in the world’s poorest regions with that in developed countries, an interesting scenario emerges. In first world countries, the incidence of AIDS is greatest among third world communities, that is, communities in developed countries that mimic conditions of life in third world countries. In the United States, for example, a Centers for Disease Control and Prevention (CDC) report that appeared in June 2005 estimated that more than 1 million Americans were living with the HIV/AIDS virus, up from between 850,000 and 950,000 in 2002. The report explained that the increase is due to the fact that people suffering from AIDS are living longer because of the availability of powerful drugs. Importantly, the report indicated that African Americans make up 47 percent and gay and bisexual men represent 45 percent of HIV/AIDS cases in the United States.
The categories “black,” “gay,” and “bisexual” represent marginalized and underresourced groups in the United States; however, they do not give a good measure of comparability. The demographics for 2003 are rather revealing. For every 100,000 people in given populations, the rates of HIV/AIDS infection were as follows: 58 for blacks, 10 for Hispanics, 8 for American Indian/Alaska, 6 for whites, and 4 for Asian/Pacific Islanders. The rates for all other groups combined are less than half of the rate among the black population. One wonders whether this is coincidence or an accident; it is as if to suggest that black people everywhere have been especially marked for the disease. Other Deadly Diseases In addition to AIDS, there are other deadly diseases that afflict millions of poor people worldwide. A WHO report in April 2005 stated that outbreaks such as Ebola and Marburg in Africa and severe aute respiratory syndrome (SARS) in Asia may arouse genuine fears in people, but they are not the biggest killers. Diseases such as malaria, diarrhea, tuberculosis, measles, meningitis, tetanus, and syphilis continue to kill millions in nations in Africa and southeast Asia, although in absolute terms the rate of death is greatest in Africa than anywhere else. According to the report, malaria kills between one and five million people around the world every year, and 90 percent of the deaths occur in Africa where a child dies of malaria every 30 seconds. A CNN news report in April 2005 stated that malaria costs Africa $12 billion a year. In southeast Asia, a similar trend can be observed. The WHO director for the region, Dr. Uton Muchtar Rafei, told a conference on tuberculosis (TB) and malaria in Dhaka, Bangladesh, in November 2000, that about 25 million people suffered from malaria and over 1.25 billion people were at risk of infection in the region. With reference to TB, Rafei said that about 40 percent of the people in southeast Asia were infected and more than 1.5 million died in 1999 alone. He said that 95 percent of TB cases worldwide occur in poor countries and that in these countries, poor people are the most vulnerable. In addition, in southeast Asia, a joint mission of international donors visiting Afghanistan in April 2002 drew attention to the appalling state of health delivery in the war-ravaged country, especially in rural areas where the doctor–patient ratio is one to 100,000. The
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mission reported that only 65 percent of Afghans had access to health facilities, while only 32 percent of children were immunized against childhood diseases. The mission recommended that donors would have to invest $200 million in healthcare to enable Afghans to move beyond the cycle of disease and deprivation. How Disease Occurs Given the spread of diseases in poor countries it is necessary to examine how they occur. HIV/AIDS is a good example. Some people, mostly a few evangelical Christians, have suggested that HIV/AIDS is divine punishment to curb promiscuity and homosexuality. There is even an apocalyptic ring to that suggestion and it says that in the last days incurable diseases will afflict humanity. To some Christians, then, HIV/ AIDS and other deadly diseases point to the end of the world. To the extent that the medical and scientific community has not yet developed a cure for HIV/ AIDS, these Christians may continue to hold their unique perspective on the disease. Indeed, HIV/AIDS is largely a sexually transmitted disease; however, it is not solely the disease of the sexually promiscuous, although such people stand a greater risk of infection. Millions of children have been born with the disease through no fault of their own, while others have contracted the virus through blood transfusion or intravenous needle-sharing with infected persons. What is evident is that HIV/AIDS has emerged as the disease of the poor both in developed and developing nations. One important factor regarding the spread of AIDS is that of government intervention and public responsibility. In rich countries, governments spend millions of dollars educating people and funding research to find a cure for the deadly disease. An MSNBC news report of July 5, 2005, states that the U.S. government passed a law that required all expectant mothers to undergo an HIV/AIDS test. The purpose was to protect unborn babies from contracting the virus from mothers who may be infected. This was a great preventative measure that served as the first line of defense against the disease in children. The government could pass this act because it had the resources to carry out the tests. But it is one thing to diagnose a disease and another thing to offer a cure to the afflicted. About 39 million Americans do not have health insurance, meaning that they do
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not have access to quality healthcare. If any of them contracts the HIV/AIDS virus they would not know that they are carriers and would unknowingly pass it on to partners. Thus even in the richest country in the world, the danger of AIDS is a factor of poverty. The situation is worse in poor countries where governments cannot fund research or import retroviral drugs to curb the spread of HIV/AIDS. In terms of educating the public about safe sex, governments in these countries face an uphill battle because of illiteracy, ignorance, and poverty. Radio and television advertisements have not been effective because the target group does not have access to such technology. Myths about the causes of the disease and traditional ideas about sex have inhibited efforts to curb the spread of the disease. In a February 2001 edition of Time, Johanna McGreary offered insights into how myths fed the spread of the disease in Africa. Some attributed infection to witchcraft, action by angry ancestors, or, in the case of South Africa, a ploy by whites to control the black population when apartheid finally ended. These beliefs could hardly help the people to understand the enormity of the danger with which they were confronted. And when they finally understood what they were up against, the stigma attached to the disease (because it is sexually transmitted) led infected persons to keep quiet about their condition. In the United States and Canada, people testing positive for the virus are required by law to inform their spouses if they are married. In Africa there is a “don’t tell” culture surrounding the disease. Even doctors do not indicate on death certificates that patients died of HIV/AIDS, in accordance with local practices. In the majority of cases, infected people did not know that they carried the virus and attributed its manifestation to malaria, TB, diarrhea, or any other disease that would crumble their already compromised immune system. These carriers would unknowingly spread the disease until they are too weak to engage in sex. By then, their partners might have carried it on to others, creating a ripple effect that is difficult to arrest. Once people have contracted the virus, they wait to die. In rural areas where patients may not have access to clinics, these people are treated as outcasts, condemned, and neglected because of their particular type of disease. Those who end up in hospitals may live a little longer because of the rudimentary treatments that they receive. Governments
are now struggling to increase the importation of generic drugs to prolong the lives of people carrying the HIV/AIDS virus. When we move beyond AIDS and consider diseases such as malaria, cholera, and TB, we see how poverty couples with ignorance to make people irresponsible. Malaria is spread by mosquitoes, and mosquitoes breed in stagnant water, dead weeds, and damp and dirty surroundings. The hot and humid climate in Africa and parts of Asia is ideal for mosquitoes to thrive; incidentally, these are places where drainage systems are poor and sanitation is worse. People dispose of garbage and human waste in utter disregard of the health consequences. Huge garbage dumps spring up in residential areas where mosquitoes breed in large numbers. The majority of people sleep without treated mosquito nets, thus becoming vulnerable to mosquito bites. Governments do not have enough resources to spray the mosquitoes or import medicines. And so like HIV/AIDS, people suffering from malaria only hope that they will be lucky. If not, they die. That is the sad reality of the impact of poverty on human health. In rural areas in western Africa, for example, villagers dig pits as places of convenience. These open pits attract flies that may settle on food. When it rains, feces washes into streams that may also serve as sources of drinking water for other rural populations. In towns, human-waste management is left in the hands of “night soil men” (men who clear pan loads of feces every night) who dig bigger pits where they dump the waste. The problems associated with human waste in rural areas occur in towns on a larger scale. Although city populations have potable water they still live with the stench and flies that have feasted on the feces. Even houses and facilities that have water closets are not entirely free from the problem of human waste. Cesspools are poorly constructed and easily spill over, leaving dark streams of toxic human waste that pollute the atmosphere. As the world waits for G-8 leaders to take action on world poverty, a British government official has said that people expecting total eradication of poverty would be disappointed. Some may see the comment as bad for its timing, but sadly, it is true. Even if rich nations create clean financial slates for poor African countries, they would have to find strategies to deal with disease on the continent. McGreary summed it up best when she said that “Here [Africa] the disease
Disease Prevention
[HIV/AIDS] has bred a Darwinian perversion. Society’s fittest, not the frailest, are the ones who die.” When the generation of working people is dying out because of disease, there is no amount of debt relief that can salvage sub-Saharan Africa from despair and demise unless disease has been brought under control. SEE ALSO: AIDS; Nutrition; South Africa. BIBLIOGRAPHY. Tony Barnett and Alan Whiteside, AIDS
in the Twenty-First Century: Disease and Globalization (Palgrave Macmillan, 2003); CNN, “WHO Finds TB, Malaria Return as Killer Diseases,” www.cnn.com (cited June 2005); Denise Grady, “Just How Does AIDS Spread?” Time (March 21, 1988); Johanna McGreary, “Death Stalks a Continent,” Time (February 12, 2001); Christine McMurray and Roy Smith, Diseases and Globalization: Socioeconomic Transitions and Health (Earthscan/James & James, 2000); Jeffrey Sachs “The End of Poverty,” Time (March 14, 2005). Martha Donkor, Ph.D. Edinboro University
Disease Prevention Disease prevention is essential in preserving lives, maintaining quality of life, and mitigating the enormous financial burden associated with unhealthy populations. Around the world, the leading causes of death are largely preventable by making alterations in lifestyles and practicing basic safety measures that prevent the spread of infectious diseases and help to forestall accidents. In developed countries, the leading causes of death are ischemic heart disease, cerebrovascular disease, chronic obstructive pulmonary disease, lower respiratory infections, trachea, bronchus, and lung cancers, vehicular accidents, stomach cancer, hypertensive heart disease, tuberculosis, and suicide. While the developing world shares some of the affects of lifestylerelated diseases, they also have unique vulnerabilities to diseases that are generally under control in the developed world. The leading causes of death in developing countries are HIV/AIDS, lower respiratory infections, ischemic heart disease, diarrheal disease, cerebrovascular disease, childhood diseases, malaria, tuberculosis, chronic obstructive pulmonary disease, and measles.
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At the global level, the major steps in disease prevention include combating poverty, increasing surveillance of disease outbreaks, providing assistance to countries that report health problems, restricting transport of people and goods out of infected areas, developing tests that provide early detection capabilities, and making vaccines and antiviral drugs available wherever needed. At the national level, all countries need well-established infrastructures that guarantee access to healthcare, ensure safe drinking water and improved sanitation, and monitor public health. Both national governments and international organizations need to take greater responsibility for promoting preventive care at the individual level through information dissemination and programs designed to encourage populations to practice preventive measures that include avoiding tobacco and excessive alcohol consumption, obtaining prenatal and postnatal care, maintaining healthy weight levels, eating more fruits and vegetables and less fat, salt, and sugar, being physically active, immunizing children against preventable diseases, washing food, hands, and utensils to avoid food contamination, practicing birth control and safe sex, controlling chronic diseases such as diabetes and high blood pressure, practicing home and vehicular safety, and maintaining good mental health. In the poorest countries of the world, disease prevention and treatment require concentrated efforts by international organizations such as the United Nations, the World Health Organization (WHO), and the United Nations Children’s Fund (UNICEF) as well as by national and private organizations. The United Nations Millennium Goals recognize that the key to disease prevention is fighting poverty. Specific goals include reducing child mortality by two-thirds, cutting maternal mortality by three-fourths, and reversing current trends in infectious diseases such as AIDS, tuberculosis, and malaria. The Global Fund to Fight AIDS, Tuberculosis, and Malaria awards grants for programs designed to prevent and treat these diseases while requiring accountability and success in meeting target goals. The United States government has earmarked funding for disease prevention and treatment through the Millennium Challenge Account and the President’s Emergency Plan for AIDS Relief. In June 2007, at the annual summit of the Group of Eight (G-8) industrialized nations, delegates
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pledged $60 billion a year earmarked for prevention and treatment programs for HIV/AIDS, malaria, and tuberculosis in Africa and for strengthening health systems in the least developed countries. Private funding is also essential in dealing with disease prevention at the global level. For instance, in June 2007, the Sabin Vaccine Institute, an organization devoted to eradicating diseases associated with poverty announced that actress and humanitarian Alyssa Milano had been named a founding ambassador of the newly created Global Network for Neglected Tropical Diseases (NTDs). The institute is dedicated to calling public attention to the 13 chronic and disabling bacterial and parasitic infections that are collectively known as “diseases of poverty.” Those diseases, which include hookworm, schistosomiasis, river blindness, and elephantiasis, currently affect a billion people in developing countries. Milano’s personal pledge of $250,000 and a matching grant are being used to eliminate lymphatic filariasis (LF) in the southeast Asian nation of Myanmar under the direction of the Lymphatic Filariasis Support Centre of the Liverpool School of Tropical Medicine. An earlier $8.9 million grant is being used to eliminate NTDS in Rwanda and Burundi. Promoting healthy lifestyles Disease prevention also involves educating the public about what is involved in leading healthy lifestyles. The elimination of tobacco products may be the single most important factor in preventing a number of diseases. While most of the emphasis on the dangers of smoking has focused on risks to smokers, newer research has documented an alarming trend in conditions and diseases linked to passive smoke, including eye irritation, headache, cough, sore throat, and dizziness. Passive smoke can also exacerbate existing health problems. In homes where anyone smokes, all members of the household have a 25 percent higher risk of developing lung cancer and heart disease; and smoking and heavy alcohol consumption have been linked to cancers of the upper and lower gastrointestinal tract. Children in homes where someone smokes are susceptible to low birth weight, respiratory illnesses, middle ear infections, and mortality. Infants are at an increased rate for sudden infant death syndrome (SIDS). Good nutrition is one of the building blocks of disease prevention. The human body is designed to
extract vitamins, minerals, and other substances from food to maintain health and energy. In developing countries, the poorest segments of the population are often undernourished. Consequently, residents suffer from poor overall health and are vulnerable to diseases. Deficiency diseases such as xerophthalmia, anemia, scurvy, and pellagra that have been virtually eradicated in the developed world continue to occur in developing nations. Populations in developing notions are also extremely vulnerable to food and waterborne and vectorborne diseases. Throughout the world, dietary alterations are key factors in disease prevention. Dietary habits are major factors in 60 percent of male cancers and 40 percent of female cancers. Salt reduction is instrumental in reducing incidences of high blood pressure. The recognition that saturated fats are strongly linked with cardiovascular diseases has halved incidences of fatal heart attacks in the United States. The addition of folic acid to the diet of women of childbearing age has reduced the incidence of birth defects by approximately 70 percent. Adding calcium to diets helps to prevent osteoporosis. Zinc and antioxidants are believed to halt the progress of muscular degeneration, which is the leading cause of irreversible blindness. Consumption of fruits and vegetables has been associated with reducing risks of certain cancers. Fiber and possibly calcium are considered deterrents to the development of colon cancer. Infectious diseases Some 40 new diseases have been identified over the last few decades, and all have major global implications. Some of these new diseases are mad cow disease, the hanta virus (a pulmonary syndrome caused by contact with infected rats), E. coli, Lyme disease, sudden acute respiratory syndrome (SARS), and avian flu. Older diseases such as dengue fever, cholera, and tuberculosis have resurged. Malaria is one of the major causes of death among the children of Africa and is the seventh leading cause of death in developing countries. There has been a fivefold increase in the number of foodborne diseases over the past few decades. Globalization plays a major role in the spread of infectious diseases because travelers, immigrants, and goods may transport diseases from country to country. The most striking example of the link between globalization and disease occurred with the
SARS outbreak. The disease moved from a small village in rural China to the other side of the world with the result that Canada became a hotspot for SARS. By 2003, 8,100 cases of SARS had been reported worldwide and 800 people had died. The outbreaks exacted a heavy toll on the tourist industry at a cost of $7.6 billion and the loss of 2.8 million jobs. In 1985, a shipment of tires from Japan arrived in the United States containing pockets of water in which Asian mosquitoes were breeding. These mosquitoes are capable of spreading a new and more virulent form of dengue fever. The disease had been eradicated in North and Latin America for decades through pesticides. However, in the early 1980s, 800,000 new cases were reported. By the end of the decade, the incidence rate had reached over a million. Outbreaks of avian flu resulted in a worldwide scare after the disease jumped from birds to humans. Marburg fever, a deadly hemorrhagic disease, was first identified in Germany in 1967. When Marburg fever reached Angola in May 2005, 90 percent (300 people) of those infected with the disease died. Peru experienced a major cholera outbreak in the 1990s when contaminated water infected fish and shellfish. Infected fish were subsequently eaten by Peruvians. After treatment systems failed to remove the disease from water supplies, infected water was unknowingly pumped into Peruvian homes where it was ingested by unsuspecting residents. Before it was checked, cholera had spread throughout South America. In spring 2004, a polio outbreak that originated in Niger spread to Indonesia. Polio continues to be a major risk in Muslim countries where populations refuse to endorse Western vaccinations. Because of the resurgence of the disease, the WHO has accepted the responsibility for tracking polio. HIV/AIDS, which was first identified in New York and Los Angeles in 1981, is the leading cause of death in developing countries. There are approximately five million new cases of HIV/AIDS reported each year despite the fact that the disease is entirely preventable if individuals practice safe sex and refrain from sharing needles with other drug users. Strict testing of blood supplies has virtually wiped out transmission from blood transfusions in developed countries. Worldwide, about 3 million people die each year from the virus. Sixty percent of all cases are found in sub-Saharan Africa where HIV/AIDS continues to
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decimate populations in countries such as Swaziland (38.86 percent adult prevalence rate) and Botswana (37.30 percent adult prevalence rate. In the United States, with a 0.60 percent adult prevalence rate, most HIV/AIDS is spread through male-to-male sex and through unprotected heterosexual sex with infected partners. Three-fourths of all infected Americans are male. Forty-nine percent are African American, and 31 percent are white. According to the Centers for Disease Control and Prevention, out of 956,666 persons diagnosed with HIV/Aids since 1981, 530,756 have died. Widespread testing to identify individuals with the virus and landmark advances in drug therapies have resulted in lower death rates from HIV/AIDS. Children Prenatal care is an essential element in producing healthy children, and immunizations and prompt medical attention protect children from conditions that threaten health after they are born. Each year, more than 10 million children die from preventable diseases. The most common of these are polio, diphtheria, tetanus, whooping cough, measles, mumps, rubella, Haemophilus influenza type B (Hib), Hepatitis B, chicken pox, pneumonia, sepsis, and skin and throat infections. Children under the age of five are particularly vulnerable to these diseases. Before the Haemophilus influenza type B vaccination was introduced in the United States in 1992, one of every 200 children contracted bacterial meningitis. Among infected children, one in 20 died, and from 10 to 30 percent suffered permanent brain damage. Acute diarrhea is one of the leading causes of death among children. Because children with diarrhea are vulnerable to dehydration, rehydration therapies that restore the proper balance of fluids and electrolytes are essential. Educational efforts to teach mothers to care for children with diarrhea have been highly successful in a number of developing countries. In Bangladesh, for example, poor women were taught to concoct a rehydration formula using a little salt and sugar added to a cup of water. They then taught the method to other mothers. For a total cost of $9 million in aid, the death rate from acute diarrhea in Bangladesh was slashed from 50 percent to less than one percent. In countries where malaria is endemic, inexpensive insecticide-treated bed netting saves lives. Seven
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countries in southern Africa followed the example of South American countries that had been successful in eradicating malaria and sent out teams of volunteers to educate the population about malaria prevention. A subsequent campaign was designed to ensure that all children between the ages of nine months and 14 years were vaccinated against measles. International aid bore the cost of $1.10 per child with the result that in six of the countries, incidences of measles dropped 60,000 in 1996 to 117 in 2000. In Nepal, grandmothers conducted house-to-house campaigns to inform the population about polio and encourage parents to vaccinate their children. United States The United States spends more than twice as much on healthcare as any other nation in the world; yet, the population is one of the unhealthiest among industrialized nations. Much of that ill health is due to unhealthy life style choices that include diets that are high in fats and sugars, smoking, alcohol consumption, and limited physical activity. However, a deeper issue involves lack of access to healthcare that has been precipitated by rising health costs and the increasing number of uninsured Americans. While every state has its own health department and a plethora of government and private organizations are devoted to every aspect of health, there is a tendency for Americans, particularly those in the working class who do not qualify for government-assisted medical care and who may not be able to afford private insurance, to neglect preventive care, focusing on treating illness after they develop. Even among those who have Medicare and/or Medicaid, medications and treatments are not always affordable. A major reason that Americans are unhealthier than in the recent past is due to government complaisance. Before 1970, government spending on public health continued to rise. At that time, funding was cut by half. Additional cuts by the Reagan/ Bush administrations in the 1980s continued to limit the ability of the government to engage in disease prevention. In 1989, for instance, there was a rise in incidences of tuberculosis. After terrorist attacks on the United States on September 11, 2001, George W. Bush made Americans more vulnerable to ill health by shifting funding away from general health programs to antiterrorism programs.
According to a report by the World Bank, when mortality rates are age-adjusted, the United States ranks 24th in the world in mortality. Studies show that about one-fifth of Americans never fill prescriptions from their physicians, and approximately half on those who do fill them neglect to take medications consistently. In the 1950s, the United States had the sixth lowest infant mortality rate in the world. By 2007, the American had dropped to 42nd lowest (6.37 deaths per 1,000 live births) and ranked 45th in life expectancy (78 years). Because of the controversy surrounding abortion, birth control, and sex education, teen pregnancies, which present high risks to both mother and child, continue to be the highest in the Western world. A million teenage mothers give birth each year. Roughly a third abort, another third miscarry, and the final third give births. Disease prevention and preventive care are the focus of the Healthy People 2010 initiative, which has targeted 467 issues in 28 separate areas designed to make Americans healthier. Major goals include improving quality of life, eliminating health disparities, reducing obesity, increasing fruit and vegetable consumption, and decreasing consumption of fats and sodium. Focus areas include preventing and treating diseases such as arthritis, osteoporosis, cancer, kidney disease, diabetes, respiratory diseases, and sexually transmitted diseases (STDs) and promoting oral health, family planning, food and drug safety, mental health, and occupational safety and health. See Also: AIDS; Birth Defects; Cancer (General); Centers
for Disease Control; Diabetes; Gastroenterology; Immunization/Vaccination; Infant and Toddler Health; High Blood Pressure; Medicaid, Medicare, Pregnancy, Preventive Care; Sudden Acute Respiratory Syndrome (SARS); Sexually Transmitted Diseases; Sudden Infant Death Syndrome (SIDS); Suicide; United Nations Children’s Fund (UNICEF); Vitamin and Mineral Supplements; World Health Organization (WHO). Bibliography. Adrianne Bendich and Richard J. Deckel-
baum, eds., Preventive Nutrition: The Comprehensive Guide for Health Care Professionals (Humana Press, 2005); Centers for Disease Control and Prevention, “Smoking and Tobacco Use Fact Sheet” www.cdc.gov (cited February 2007); Larry Cohen, et al, Prevention Is Primary: Strategies for Community Well Being (Jossey-Bass, 2007); Tom Farley
Diverticulosis and Diverticulitis
and Deborah A. Cohen, Prescription for a Healthy Nation: A New Approach to Improving Our Lives by Fixing Our Everyday World (Beacon, 2005); William H. Foege, et al., eds., Global Health Leadership and Management (Jossey-Bass, 2005); George Fried and George J. Hademenos, Schaum’s Outline of Theory and Problems of Biology (McGraw-Hill Professional, 1999); William. A. Gunn, et al, Understanding the Global Dimensions of Health (Springer, 2005); Kelly Lee, Globalization and Health: An Introduction (Palgrave Macmillan, 2003); Alan D. Lopez, Global Burden of Disease and Risk Factors (Oxford University Press, 2006). Elizabeth R. Purdy, Ph.D Independent Scholar
Diverticulosis and Diverticulitis A diverticulum is an out pouching of the wall of the gastrointestinal tract that is sac-like in appearance. Diverticula can appear at any level of the gastrointestinal tract including the esophagus, stomach, or the small intestine; however, the most common location is the left side of the colon. Diverticulosis means that unless otherwise specified, diverticula are present within the colon. Diverticulitis is a state of inflammation within a diverticuli. While diverticulosis is rare in a patient under age 30, in Western society the prevalence approaches 50 percent in adults over age 60 and up to 25 percent of these will have complications. Given the prevalence of diverticulosis in developed societies and the relative infrequency of the disease in nonindustrialized countries, it is thought that environmental and lifestyle factors contribute to the development of diverticula. The wall of the colon is marked by longitudinal bands of muscle that are penetrated by nerves and blood vessels. The sites of penetration of these structures create defects in the muscle wall that are points of weakness for diverticula formation. The herniation of the colonic wall through these defects in the muscle can happen if there is prolonged, exaggerated contraction of the musculature as is seen when there is reduced stool bulk. A diet high in fiber will increase stool bulk and prevent the exaggerated contractions that will cause
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diverticula formation. The trend in industrialized societies to diets high in carbohydrates, protein, and saturated fats explains the higher prevalence of diverticulosis in these nations. The diagnosis of diverticulosis is often incidental, found during testing for other reasons such as a screening colonoscopy. The majority of people with diverticulosis will remain asymptomatic. Diverticulitis, or inflammation of diverticula, occurs when there is erosion of the wall of a diverticuli as a result of decreased local blood flow. The decreased flow may be a result of increased colonic wall tension or the impaction of stool within the diverticuli. Diverticulitis can be divided into simple and complicated forms. The overwhelming majority of cases, around 75 percent, are considered simple diverticulitis, which is not associated with complications and will respond to medical management. Surgical intervention is rarely necessary. Conversely, complicated diverticulitis will often require surgical intervention. As the wall of the intestine is eroded by inflammation, symptoms can develop which include abdominal pain or cramping, nausea and vomiting, diarrhea or constipation, and urinary symptoms. Complications of diverticulitis can include abscess formation within the diverticuli, obstruction of the colon, and perforation of the colon leading to peritonitis and sepsis. In addition, a fistula, or an abnormal connection between two structures, can develop between the bowel and the surrounding anatomy such as the bladder or the vagina. Treatment of diverticulitis varies depending on the severity of disease. Patients with asymptomatic diverticulosis are often advised to increase fiber intake to prevent development of new diverticula. Patients with simple diverticulitis and mild symptoms can be treated on an outpatient basis with oral antibiotics and a clear liquid diet. If severe symptoms are present, the patient may be admitted to the hospital for intravenous fluids and antibiotics while being kept fasting. If there is obstruction, fistula formation or peritonitis surgery may be necessary to resect the diseased area of the colon or to close the fistula. In conclusion, diverticulosis is a mostly benign condition that can develop complications leading to hospitalization and surgical intervention. SEE ALSO: Colonic Diseases (General); Gastroenterology.
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Bibliography. Vinay Kumar, Abul Abbas, and Nelson
Fausto, Pathologic Basis of Disease (Elsevier Saunders, 2005).
Kristen Mamelian University of Missouri, Kansas City
Dizygotic Twin Two siblings who come from separate ova, or eggs, that are released at the same time from an ovary and are fertilized by separate sperm. Dizygotic twins are also known as fraternal twins. The term originates from di or two and zygote or eggs. In order for this to occur, two eggs need to be present, referred to as double ovulation, as well as the presence of two separate sperm. This is very rare and the causes are still under study and research. Across the world, the occurrence of dizygotic twinning varies. Throughout the world, dizygotic twins can be seen as a family blessing or financial curse. Dizygotic twins develop in the uterus separately. Each zygote develops with its own chorion or outer sac. This chorion is connected to the placenta which is the outermost protective membrane around the developing fetus. The placenta lines the uterine wall, partially envelopes the fetus, and is attached to the umbilical cord. The placenta exchanges nutrients, wastes, and gases between maternal and fetal blood. Each zygote also has its own inner sac that contains amniotic fluid. Dizygotic twins each have its own placenta; however, if the two zygotes implant in the uterus close together, it may appear on an ultrasound as one placenta. Dizygotic twins may have different fathers, meaning that one egg is fertilized by one sperm and the other egg is fertilized by a different father with different sperm. These cases are rare and few have been documented. Due to their being two separate zygotes, the genetic makeup is different and dizygotic twins are not identical. On average, these twins will share half of their genes, just like any other siblings. Twothirds of twins are fraternal and may be the same sex or be a male and female pair. Dizygotic twins are most common for older mothers, with highest rates for mothers over the age of 35 years. With the advent of technologies and techniques to assist women in getting pregnant, the rate
of fraternal twins has increased markedly. Other possible predispositions to dizygotic twins are mothers who are taller and heavier, the recent discontinuation of oral birth control, possible genetic predispositions that involve excess secretion of follicle-stimulating hormone (FSH), emotional stress, and diet. Diet may play a role as seen in African mothers from Nigeria in the Yoruba tribe that have high frequency of dizygotic twins and have a significant diet of yams. Last, environmental stress from chemical agents in highly polluted areas may reduce sperm count, thus decreasing the frequency of fraternal twinning. The key concept here is that while certain background factors may be important, fraternal twinning is influenced by a complex mix of events that are poorly understood. In poorer countries, fraternal twins may cause financial hardship. However, in some cultures throughout the world, dizygotic twins are seen a gift to the family and society. Epidemiology Historically, about one in 100 to 125 human births results in a twin pregnancy in North America. In Japan, rates vary from one or two per 1,000 and can be as high as 14 per 1,000 in Africa. The rate of twinning varies greatly among ethnic groups. The widespread access and use of fertility medications has aided in an increase in the birth of fraternal twins. Fertility medications may cause a stimulated release of multiple eggs by the mother that cause dizygotic twins. SEE ALSO: Birth Rate; Fraternal Twins; Monozygotic Twin. Bibliography. Nancy Segal, “Chapter 1: Identical and
Fraternal Twins: Living Laboratories,” in Entwined Lives: Twins and What They Tell Us about Human Behavior (Penguin, 1999).
John M. Quinn V, M.P.H. University of Illinois at Chicago
Dizziness and Vertigo Dizziness is a common complaint for which patients seek medical advice. Dizziness is typically defined as one of four types: vertigo, lightheadedness, disequi-
librium, and presyncope. Differentiation of these types is necessary in the diagnosis, management, and treatment. However, this can be challenging because symptoms associated with each of these conditions (including nausea, vomiting, and diaphoresis) may be difficult for patients to describe. Additionally, comorbid chronic conditions over time may confound the picture. It is difficult sometimes to discern if symptoms are related to an acute illness or a new symptom of a chronic disease. The differential diagnosis of the symptom of dizziness is large and may be a side effect of many of the body’s systems. Seizure disorders may present with dizziness as a symptom, as well as psychiatric disorders and motion sickness. Ear disorders including otitis media and impacted cerumen may also present with dizziness. Vertigo specifically is the illusion of movement (typically rotational motion). Vertigo is also the most prevalent type of dizziness. It is important to differentiate whether the symptoms of vertigo are from peripheral vestibular causes, from central causes, or from other conditions such as drug side effect or chronic neurologic disease. To determine if the patient truly has vertigo or another type of dizziness, it is common to inquire if the patient “feels lightheaded” or if “the room appears to be spinning around.” Often, patients with true vertigo will respond that the room appears to be spinning. An accurate history must be performed to help narrow the differential diagnosis. Inquiring about the timing and duration of the dizziness, exacerbating and remitting factors, associated neurologic symptoms, and any hearing loss should be performed as well as queries about medications, toxic exposures, and trauma. Diagnosis of dizziness and vertigo further depends upon physical examination, with particular attention to examination of the head and neck, cardiovascular system, and neurologic findings. Orthostatic changes in systolic blood pressure and pulse may identify patients with underlying dehydration or autonomic dysfunction, in addition to changes in blood pressure resulting from medical treatment of hypertension. Orthostatic hypotension, defined as a drop in blood pressure of at least 20 mm Hg systolic or 10 mm Hg diastolic within three minutes of standing may be diagnostic of the problem. Additionally, a resting pulse >100 may indicate some volume depletion. Irregular-
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Dizziness is typically defined as one of four types: vertigo, lightheadedness, disequilibrium, and presyncope.
ity of the pulse which includes both bradycardia, or slowing of the heart, and tachycardia, or increasing the speed of the heart rate, may further contribute to underlying cardiovascular abnormalities that may lead to vertigo as a symptom of presyncope, or an actual syncopal, episode. The Dix-Hallpike maneuver may assist in the diagnosis of benign paroxysmal positional vertigo (BPPV). Because this procedure sometimes provokes the symptoms, the patient must be aware that the symptoms may temporarily worsen while performing the procedure. Through some specific movements, the physician moves the patient’s head from an upright position to a supine position, resulting in minimal hyperextension of the neck. A positive test results in horizontal nystagmus which changes direction when the patient sits upright again. Although a positive DixHallpike maneuver may be helpful to differentiate the diagnosis of patients with vertigo, it is not absolutely pathognemonic for BPPV. Peripheral causes of vertigo include factors that exacerbate the normal functions of the organs of the ear. Commonly, a viral or bacterial infection can inflame the labyrinthine organs. Additionally, the vestibular nerve itself can become inflamed, usually from a self-limited upper respiratory viral infection, while the vesicular
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eruption of herpes zoster may, in addition to causing skin symptoms and pain associated with this infection, also affect the ear and cause vertigo. While BPPV causes transient episodes of vertigo symptoms because of calcium debris in the semicircular canals, the etiology of Ménière’s disease appears to be caused by an increased amount of endolymph in the semicircular canals of the ear. A cholesteatoma, a benign cyst-like tumor filled with debris, can involve the middle ear and mastoid which may also cause vertigo. Over time, thickening of the tympanic membrane caused by age or chronic recurrent infections may cause otosclerosis which contributes to hearing loss and subsequent vertigo. Trauma, either a direct blow to the ear or indirectly from barotrauma of scuba diving or heavy weight bearing, for example, may cause perilymphatic fistulas to form which may result in vertigo. Central causes of vertigo are those etiologies that involve the brain. The location of certain tumors may cause symptoms, as may cerebrovascular disease affecting arterial flow to the brain, or subsequent ischemia or infarction resulting in transient ischemic attack or stroke. Some migrainous headaches cause vertigo as part of its pattern, either as part of the aura preceding the headache or part of the migraine itself. Other chronic neurologic conditions, such as multiple sclerosis, which causes demyelinization of the white matter in the central nervous system, may also contribute to the symptoms. Other causes of vertigo exist. Occasionally, vertigo may result from somatosensory input from head and neck movements. Adverse reactions from medications or drugs may contribute to vertigo. Additionally, psychologic stress may cause a symptom of vertigo, as it relates to hyperventilation associated with anxiety and panic attacks. Laboratory testing should be considered in the diagnosis of vertigo, especially if there are additional symptoms or if there is a concern about medication side effect or electrolyte abnormality. Also, a formal audiometry test should be considered for those patients complaining of hearing loss. Radiologic studies should be considered in patients with additional neurologic symptoms, patients with risk factors for cerebrovascular disease, or progressive unilateral hearing loss and consideration for neuroimaging should also occur for any localizing neurologic symptom.
Treatment of dizziness and vertigo depends upon the etiology of the symptom. Several medications exist to treat the concurrent nausea and vomiting associated with the disorder. However, those medicines are usually treating the side effects of the vertigo, not the underlying cause, which is why diagnosis is so imperative. SEE ALSO: Arrhythmia; Ear Disorders; Fainting; Multiple
Sclerosis; Neurologic Diseases (General).
Bibliography. Jon E. Isaacson and Neil M. Vora, “Dif-
ferential Diagnosis and Treatment of Hearing Loss,” American Family Physician (v.68/6, 2003); Ronald H. Labuguen, “Initial Evaluation of Vertigo,” American Family Physician (v.73/2, 2006); Thomas H. Miller and Jerry E. Kruse, “Evaluation of Syncope,” American Family Physician (v.72/8, 2005); Randy Swartz and Paxton Longwell, “Treatment of Vertigo,” American Family Physician (v.71/6, 2005). Ann M. Karty, M.D. Kansas City University of Medicine and Biosciences
Djibouti Djibouti is located on the eastern coast of Africa, a small, narrow country between Eritrea to the north, Ethiopia to the west and south, and Somalia to the southeast. Yemen is 12 miles off the coast, across the Gulf of Aden. The country has historical ties to France. Ninety-two percent of Djiboutians are Muslim, with 60 percent belonging to the Issa people, 35 percent to the Afar, and the remainder a mix of Arab, Ethiopian, and European. The population is 486,500, growing at a rate of 2.2 percent annually. The birth rate is 39.53 per 1,000 and the death rate is 19.31 per 1,000. With its favorable location at the end of the Red Sea, Djibouti’s economy is almost entirely reliant on shipping. Most of the population, 86 percent, lives on the coastline, with just a minority of nomadic peoples subsiding in the hot, dry interior. Unemployment in Djibouti is 50 percent, and per capita income is $1,030 per annum. Life expectancy at birth is 54 years for males and 57 years for females, with healthy life expectancy at 42.5 years for men and 43 years for women. Infant mortality is 102 deaths per 1,000 live births. The death rate
DNA
for children aged 1–5 years is 126 per 1,000. Maternal mortality is high at 730 deaths per 100,000 live births. About 60 percent of births are monitored by a trained attendant. Sanitation within the country is limited, with 80 percent of Djiboutians having access to clean water and 50 percent having sanitary facilities. Hepatitis A and E, typhoid, malaria, and dengue fever are common. Djibouti has a high rate of tuberculosis infections, with 100 cases per 100,000 people. Polio has been identified in all neighboring countries and is suspected to be present in Djibouti as well. Immunization rates for children against polio and other illnesses are about 60 percent. A single case of avian flu was detected in May 2006. The human immunodeficiency virus (HIV)/AIDS rate is 2.9 percent, with an estimated 9,100 Djiboutians infected with the virus and 690 deaths from this disease. The highways passing through Djibouti from Ethiopia are among the busiest on the Horn of Africa, and an active sex trade exists between truckers and the poverty-stricken women who live along the way. A 2005 survey by the United Nations Children’s Fund (UNICEF) found that 48 percent of Djiboutians under age 24 did not know that using condoms could help prevent the disease. UNICEF set up an education center in an old shipping container left by the side of a highway; it also hands out an average of 300 condoms a day. Female genital mutilation (FGM) is widely practiced in Djibouti, with the U.S. State Department estimating that 90 percent to 98 percent of girls under age 10 are undergoing the procedure. Girls from the Issa and Afar tribes are usually given type II FGM, called excision—the removal of the clitoris and the labia minora. Girls from Yemeni tribes are generally given type III, also known as infibulation—the removal of the clitoris, labia minora, and labia majora, with the vagina sewn up with only a tiny hole left open for the passage of urine and menstrual blood. Medical services are limited and are largely restricted to Djibouti City and outlying towns. Those who live in the interior have little access to healthcare. In 2004, the World Health Organization counted 129 physicians and 257 nurses working in the country. SEE ALSO: Healthcare, Africa. Bibliography. James Morrow, Djibouti (Modern Middle
East Nations and Their Strategic Place in the World Series)
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Mason Crest Publishers, 2002); Peter J. Shraeder, Erick J. Mann, Djibouti, (ABC-CLIO, 1991). Heather K. Michon Independent Scholar
DNA DNA is the abbreviation for the double helix molecule, deoxyribonucleic acid. It is a long chain polymer (polynucleotide) which is found is all living cells. Using its chemical patterns it directs the formation, growth, operations and reproduction of individual cells and thus of organs and of living organisms. The DNA molecule is very long and is like a spiral staircase or a double helix in structure. The structure of DNA was first discovered by James D. Watson and Francis H. C. Cricket in 1953. The discovered of the structure opened the way for detailed understanding of the chemistry of the DNA molecule and of genetics as well. DNA molecules are composed of two polynucleotide strands wrapped around each other to form a double helix. They consist of two long nucleotides composed of a sugar molecule and a phosphate group bonded to a DNA base. This sequence is repeated numerous times to form genes and chromosomes. The legs of the DNA spiral staircase have major and minor groves. Other chemicals form the connecting steps. The whole molecule is composed of thousands of smaller chemical units called nucleotides which are bonded together to form polynucleotides. Nucleotides are composed of a phosphate, a sugar (deoxyribose) and another compound which is called generally a base. The sugar is 2’-deoxyribose which has five carbon atoms. The carbon atoms in the sugar molecule are named 1’ (prime), 2’ and so forth. Hydrogen bonds between bases on the two DNA strands stabilize the double helix. There are four types of bases: adenine, guanine, thymine, and cytosine. The adenine and guanine bases have two carbon-nitrogen rings and are purines. The thymine and cytosine bases have a single ring and are pyrimidine. The bases are attached to the 1’ carbon of the deoxyribose. It takes a sugar plus a base to make a nucleoside. Nucleotides have one, two, or three phos-
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phate groups. These are attached to 5’-carbon atom of the sugar molecule. The bases vary in the nucleotides, but the sugar and the phosphate are the same in all DNA nucleotides. Nucleotides may be individual molecules or they may be polymers of DNA or ribonucleic acid (RNA). It is the varying combinations of bases that create the power of the DNA molecule to replicate itself thus to grow new living cells. The nucleotides bonded as triphosphates of the four bases that are boned into DNA polynucleotide chains. The base adenine is a heterocyclic aromatic organic compound. It is composed of a pyrimidine ring which is fused to an imidazole ring. There are two types of nitrogenous bases—purine and pyrimidines. Purines are the essential part of both deoxyribonucleotides (DNA) and ribonucleotides (RNA). In addition to its role in DNA and RNA adenine is an important part of many organic chemical reactions and processes. The reactions include protein synthesis and cellular respiration. In earlier chemistry adenine was often identified as vitamin B4, but understanding has been modified. Adenine combines with two of the B vitamins—niacin and riboflavin. These form into essential cofactors. Some evolutionists have argued that adenine was synthesized from hydrogen cyanide (HCH) to begin the formation of life; however, this view is not universally held. Adenine forms nucleotides of DNA from its purine nucleobases. Its hydrogen molecules bond in DNA with thymine. In RNA adenine bonds with uracil and is a part of protein synthesis. Other reactions involving adenine include the formation of adenosine by bonding with ribose and deoxyadenosine by bonding with deoxyribose. It also bonds with phosphate groups to form denosine triphosphate (ATP). Cellular metabolism uses chemical energy from chemical reactions through adenosine triposphate. The DNA base guanine (C5H5N5O) is a purine with a pyrimidine-imidazole ring system with conjugated double bonds. It has a keto form and an enol form. With three hydrogen bonds it binds to cytosine which acts as an hydrogen donor. Specific locations in the guanine structure act as hydrogen acceptors. It is present in both DNA and RNA. Thymine (5-methylluracil) is a DNA base that is a pyrimidine nucleobase. It is a derivative of methylation of uracil at the fifth carbon atom. It is a part of the DNA molecule. However, in RNA it is replaced by uracil. In
DNA, thymine (T) bonds with adenine (A). The atomic structure of the nucleic acid is stabilized with two hydrogen bonds. Deoxyribose combines with thymine to form nucleoside deoxythymidine known as thymidine. It can bond with phosphates to form posphorylated molecules on the one, two, or three phosphoric acid groups. These form, respectively, TMP, TDP, or TTP. dna replication In DNA replication a common mutation occurs with two thymines or a cytosine are exposed to ultraviolet (UV) light. The UV light causes thymine dimmers to form. This causes pattern disorder in the DNA molecule and blocks its normal functioning. The DNA base cytosine was first discovered in 1894. It is a phyimidine derivative with a heterocyclic aromatic ring. Isolated from the thymus tissue of a calf it was within 10 years synthesized in laboratory experiments. Its atomic structure was understood by 1903. It is one of the nucleotide bases of DNA. It has a key role in genetic information transmission. Cytosine bonds with guanine with three hydrogen atoms. DNA has the ability to transmit genetic information that is needed by living cells to reproduce. This ability is closely related to the structure of DNA. While DNA is a polymer it is composed of long chain monomer (nucleotides). In each nucleotide is a sugar, a nitrogen molecule in the form of a molecular ring (base) and a phosphate base. The characteristic double-helix structure is a repetition of bands in a regular pattern. The DNA helix executes a turn after set of 10 base molecules. From a top view the DNA molecule looks like a stack of plates set on top on one another. From a side view it has on the opposing strands a distance that makes it “antiparallel.” Variants of DNA forms occur when the molecule and crystalline forms of the molecule form under different conditions. The A form is more compact than the B form found in living cells. The C, D, E forms also exist. The Z form takes a left-handed double-helix shape. Complementary base pairing between the two polynucleotide chains is fundamental to the structure and functioning of DNA. The bases of the two polynucleotides interact with one another. This is possible because the space between the two polynucleotides is at a distance that allows the two-ring purine molecules to engage the single ring pyrimidine molecules. The bases of the two polynucleotide chains interact with each other. Adenine and react with thymine
because the two ring purine molecules react with single ring pyrimidine. Guanine reacts with cytosine. The hydrogen bonds that bond between the bases are stabilizing. Two hydrogen bonds form between A and T, while three hydrogen bonds from between G and C in complementary base pairing. The sequence is predictive because they bonding must follow a pattern. It allows one strand to compliment and thus to replicate the other strand. The bonding of A to T and G to C a sequential pattern is formed. Because of the size of the molecules A and G or C do not bond because they cannot fit into the double helix nor may hydrogen bonding occur. The complementary bonding of the base pairs allows one strand to replicate the other strand. It is this vital mechanism that allows the expression of genetic information via messenger RNA molecules. The structure of RNA is similar to DNA, but with some significant differences. The RNA molecule replaces 2’-deocyribose and the base thymine with uracil. It can base pair with adenine. Moreover, RNA molecules exist normally as a single polynucleotide strand and not as a double helix. However, it is possible for it to have base pairings that occur for a short period of time creating double stranded regions. The DNA polymer encodes genetic information in the sequences of the bases in the DNA molecule. It does so in a series of genes. Genes are units of information. They correspond to specific segments of the DNA. They encode the amino acid sequence of a polypeptide. Human cells have 23 chromosomes. They genes are dispersed along the DNA molecule. In between the genes lie noncoding intergenic DNA sequences. Because of the coding sequencing can act as template strands DNA molecules have a vast range of genetic informational coding possibilities. Some of the genes are arranged in clusters. Operons occur in bacteria and contain coregulated genes. Higher organisms have multigene families. These genes are identical or similar, but they are not regulated in a coordinated manner. The expression of the genetic information in the genes in DNA is done by the genes. The expression process has a RNA copy made of the gene. It then makes a protein which allows cells to function. Cells use many proteins to in a orchestrated manner. The success of gene expression manufactures proteins at the right place and time.
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Gene expression is very restricted because while a number of genes may be present in a cell only a few are active. In addition, different types of tissue cells express different genes. The promoter which is a related segment of DNA regulates the coding sequence. A series of segments called exons are separated from the noncoding sequences (introns). The exons are responsible for most of the coding sequencing. The promoter binds RNA polymerase and associated transcription factor proteins. It also begins the process of synthesizing an RNA molecule. In replication the introns are removed from RNA transcripts of the gene’s code. Between genes the number and size of introns varies. Splicing eliminates them from replication. In this process mistakes can occur. There are pseudogenes which are simply mistakes that are nonfunctional. Physically a gene is a discrete segmane of DNA with a base sequence that encodes the amino acid sequence of a polypeptide. Gene segments of DNA vary widely in size. They may have as little as a hundred base pairs. Or they may have several million base pairs. Higher organisms including humans have gene sequences arranged in a very long sequence of DNA molecules called chromosomes. In humans there are at least 20,000 to as many as 25,000 genes arranged on 23 chromosomes. Intergenic DNA molecules separate the genes from one another. The intergenic DNA material does not seem to have a role in replication. The biological information is carried on just one of the strands of DNA. It is
National Human Genome Research Institute researcher Elizabeth Gillanders, Ph.D., monitoring a DNA sequencing machine.
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the template strand and it produces the complementary RNA molecule sequence which orders the synthesis of a polypeptide. The nontemplate strand of DNA has potential to act as a template strand. The strands of DNA are also called sense and antisense strand or coding and noncoding strands. In general genes are spread along the chromosomes in a random fashion. However, some are clustered into groups. There are two types of clusters of genes: operons and multigene families. Operons are found in bacteria. They are genes that act in a coordinated fashion so that they can encode proteins in a closely regulated manner. For example in E. coli, the lac operon has three genes. These encode enzymes that break down lactose. The bacterium uses the lac operon to enzymes to break down lactose as an energy source in a coordinated manner so that they switch on and off together. Higher organisms do not have operons. Instead clustered genes are multigene families. The genes in multigene families are very similar or identical which is different from the genes in operons. It has been speculated that during the evolutionary process that genes clustered in order to fulfill a need for multiple copies of the gene. Different chromosomes contain multigene families which may have developed during evolution when DNA rearranged. Simple multigene families have identical genes. For example many cells need the gene product 55 ribosomal RNA. There are about 2,000 genes that produce it exiting as clustered copies. Complex multigene families have similar, but nonidentical genes. For example the globin gene family produces a series of polypeptides. These differ from each other as α, β γ, ε, χ globin molecules. These forms of globin have different amino acid groups attached to produce the difference between them. The globin polypeptides form complexes join with heme to form hemoglobin the chemical that carries oxygen to cells. Gene expression is the process by which the biological information in the DNA molecule is used by the cell. The central dogma (a term coined by Francis Crick) stated that information is transferred fro DNA to RNA to a protein. The central dogma says that the transfer of genetic information is asymmetrical. It flows in only one direction. It cannot reserve engineer a product. The process of gene expression occurs when DNA molecules copy their genetic information to a RNA molecule which it synthesizes.
The RNA molecule is created by the process of transcription. The RNA molecule then directs the synthesis of a polypeptide that has an amino acid sequence. The specific amino acid sequence is determined by the base on the RNA in the process of translation. The amino acid sequence now has a function dictated by its protein. The number of possible different human beings is limited by the number of possible combinations of bases into genes. The bases (A, G, T, C) can combine four ways. However, a gene may have three hundred bases. This gene could have a total of 4,300 possible arrangements. Every one of the possible permutation could then produce a different gene and a slightly different human. Given a total of 25,000 genes in all humans there are nn(25,000) possible combinations of bases. This is a very high number, but not an infinite one. Some of these base sets acting as genes might be lethal combinations so that the individual might not survive to birth or long afterward. However, perhaps more important than DNA is the development of a human being is their environmental experiences. SEE ALSO: Chromosome; DNA Repair; Gene Array Analy-
sis; Gene Mapping; Gene Pool; Gene Silencing; Gene Transfer; Gene and Gene Therapy; Genetic Code; Genetics. Bibliography. Terry Brown, Gene Cloning and DNA
Analysis: An Introduction (Blackwell Publishing Professional, 2006); Hugh Fletcher, Ivor Hickey, and Paul Winter, Bios Instant Notes: Genetics. 3rd ed., (Taylor & Francis, 2007); Arthur Kornberg and Tania Baker, DNA Replication (University Science Books, 2005); Benjamin Lewin, Genes VIII, (Benjamin Cummings,m 2003); Arsceni Markoff, Analytical Tools for DNA, Genes and Genomes: Nuts & Bolts (DNA Press, 2005); Ulrike Nuber, ed., DNA Microarrays (Taylor & Francis, 2005); Matt Ridley, Genome: the Autobiography of a Species in 23 Chapters (HarperCollins, 2006); James D. Watson, Double Helix: A Personal Account of the Discovery of the Structure of DNA (Simon & Schuster, 2001); James D. Watson, et al., Recombinant DNA: Genes and Genomes – A Short Course (W. H. Freeman, 2006); Michael R. R. Winfrey, Marc A. Rott, and Alan T. Wortman, Unraveling DNA: Molecular Biology for the Laboratory (Benjamin Cummings, 1997). Andrew J. Waskey Dalton State College
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DNA Repair DNA repair refers to the mechanisms by which a cell maintains the integrity of its genetic code. This integrity not only ensures the survival of a species, which requires that parental DNA be inherited as faithfully as possible by the offspring, but it also preserves the health of an individual. Mutations in the genetic code can lead to cancer and other genetic diseases. Successful DNA replication requires that the two purine bases, adenine and guanine, pair faithfully with their pyrimidine counterparts, thymine and cytosine. There are three types of damage that can prevent correct base pairing: spontaneous mutations, replication errors, and chemical modification. Spontaneous mutations occur when DNA bases react with their environment, as when water hydrolyzes a base and changes its structure, causing it to pair with the wrong base. Replication errors are minimized when the DNA replication machinery “proofreads” its own synthesis, but sometimes the mismatched bases escape proofreading. Chemical agents modify bases and interfere with DNA replication. Nitrosamines, found in beer and pickled food products, aklylate bases and the DNA backbone. Oxidizing agents or ionizing radiation create free radicals in the cell that oxidize bases, especially guanine. Ultraviolet (UV) rays fuse adjacent pyrimidines, preventing DNA replication. Ionizing radiation or drugs such as bleomycin can also block replication, by creating double-stranded breaks in the DNA. Base analogs or intercalating agents can cause abnormal insertions and deletions in the sequence. There are three types of repair mechanisms: direct reversal of the damage, excision repair, and recombination repair. Direct reversal repair is specific to the damage. For example, in a process called photoreactivation, pyrimidine bases fused by UV light are separated by DNA photolyase. For direct reversal of akylation events, a DNA methyltransferase detects and removes the alkyl group. Excision repair can be specific or nonspecific. In base excision repair, DNA glycolyases specifically identify and remove the mismatched base. In nucleotide excision repair, the repair machinery nonspecifically recognizes distortions in the double helix caused by mismatched bases and excises the distorted region. Recombination repair takes advantage of the fact that mammalian
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chromosomes come in pairs, and uses the sequence from an undamaged sister chromosome to repair the damaged one. Often when DNA is damaged, the cell chooses to replicate over the lesion instead of waiting for repair (translesion synthesis). Although this may lead to mutations, it is preferable to a complete halt in DNA replication, which leads to death. On the other hand, the importance of proper DNA repair is highlighted when repair fails. The oxidation of guanine by free radicals leads to G-T transversion, one of the most common mutations in human cancer. Hereditary nonpolyposis colorectal cancer results from a mutation in the MSH and MLH proteins, which repair mismatches during replication. Xeroderma pigmentosum (XP) is another condition that results from failed DNA repair. Patients with XP are highly sensitive to light, exhibit premature skin aging and are prone to malignant skin tumors, all because the XP proteins, which mediate nucleotide excision repair, can no longer function. SEE ALSO: Cancer; Colorectal Cancer; DNA; Genetic
Code; Genetics; Skin Cancer.
Bibliography. J. O. Andressoo, J. H. Hoeijmakers, and J.
R. Mitchell, Nucleotide Excision Repair and the Balance between Cancer and Aging (Cell Cycle, 2006); Donald Kufe, et al., eds., Cancer Medicine, 6th ed. (Hamilton, 2003); James Watson, et al., Molecular Biology of the Gene (Benjamin Cummings, 2003). Cindy Chang Cold Spring Harbor Laboratory SUNY Stony Brook
Dominica Dominica is a small country located in the Windward Islands of the Caribbean, between the islands of Guadeloupe and Martinique. Its virtually unspoiled beauty has won it the nickname of “the nature island of the Caribbean.” The island is 289.5 square miles (754 square kilometers) and has eight active volcanoes; 65 percent of the country is covered with rainforest. Dominica is home to the world’s second largest “boil-
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ing lake,” a fumarole, or opening, in the Earth’s crust that allows volcanic gases to heat lake water to almost 200 degrees F. The site was declared a World Heritage Site in 1997. Dominica’s population is 68,900, with a growth rate of minus 0.08 percent annually. The migration rate is minus 9.3 per 1,000, as natives leave in search of work and opportunity. The economy is based on agriculture, particularly the cultivation of bananas. The industry has been in decline since the 1990s, leading to high rates of unemployment. The country’s geographical location in the “hurricane belt” leaves it vulnerable to heavy rainfall, flash flooding, and landslides. Volcanic activity and earthquakes are common. Life expectancy is high, at 72 years for males and 78 years for females. Child mortality is quite low, at 13 deaths per 1,000 for infants under age 1, and 15 deaths per 1,000 for children aged 1–5. Maternal mortality is reported at 67 deaths per 100,000 live births. All births in Dominica are attended by trained personnel, and 100 percent of women receive prenatal care. Immunization rates for children are high, and all schoolchildren are tested for hearing and vision problems, as well as growth and development issues. Adolescents accounted for 53 percent of attempted suicides reported between 1996 and 1999. Dengue fever is the most common vector borne disease present in Dominica. Malaria was eradicated in 1962, although there are some sporadic “imported” cases. Gastrointestinal diseases such as E. coli, giardia, and typhoid are frequently reported. There was a single case of leprosy diagnosed in 1998. Mortality is driven by accidents and violence, cardiovascular disease, and cancers. Diabetes is becoming more of a health problem for Dominicans. It is the second leading cause of hospital and clinic visits and the fourth leading cause of death in adults. In 2000, there were an estimated 3,000 cases of diabetes on the island. Dominica is almost free of HIV/AIDS, with only 69 cases confirmed in 2002. There are no known tuberculosis/HIV co-infections. The Dominica healthcare system is small, with 38 doctors and 317 nurses reported in 1997. Per capita government expenditures on health are $151 annually, although citizens generally pay 100 percent of medical expenses out of pocket. The Ministry of Health monitors seven health districts, including general hospitals and community-based clinics. The
government has been active in developing programs for specific populations in need, particularly children and the elderly. See Also: Dengue; Diabetes. Bibliography. Pan American Health Organization “Dom-
inica, General Situation and Trends,” http://www.paho.org/ english/HIA1998/Dominica.pdf (cited July 2007); World Health Organization, “Dominica,” http://www.who.int/ countries/dma/en/ (cited July 2007). Heather K. Michon Independent Scholar
Dominican Republic Located in the Caribbean, this nation occupies the eastern end of the island of Hispaniola, and was a Spanish colony until gaining its independence on February 27, 1844. It has a population of 8,834,000 (2004) and there are 216 doctors and 30 nurses per 100,000 people. There are also 516 dentists in the country. Until relatively recently, the health services in much of the Dominican Republic were fairly rudimentary. It is believed that Christopher Columbus, on his first voyage in 1492, may have landed on the Samaná peninsula which was then a separate island off the north coast of the Dominican Republic. On his second voyage in 1493, he built a base at what is now Santo Domingo, and it was during this visit that he and his sailors noticed the local Taino people smoking rolled leaves of tobacco. Some tobacco leaves were then brought back to Europe, with a major effect on the healthcare around the world to the present day. The major health problems facing people in the Dominican Republic include malaria, especially in rural parts of the country; heat exhaustion and heat stroke, and schistosomiasis (bilharzia). The latter comes from parasitic worms which live in infected freshwater snails and are commonly found in rivers, lakes and especially near dams. Tourists are thus advised not to swim except in chlorinated swimming pools. There have also been cases of dengue fever, and a prevalence of human T-cell leukemia
lymphona virus in some black former slave communities in the country. By 1988, there had been 701 cases of the acquired immune deficiency syndrome (AIDS), of which 65 had died. Subsequently, AIDS increased dramatically, and HIV and AIDS are now widespread. Healthcare in the Dominican Republic is run by the Secretariat of State for Public Health and Social Welfare, with the Secretary of State having a position in the cabinet. The Asociatión Médica Dominicana (Dominican Medical Association), founded in 1941, operates from Santo Domingo, the country’s capital, and publishes the Revista Médica Dominicana. It has 1,550 members. Founded in the same year, the Asociatión Médica de Santiago (Santiago Medical Association) operates from the city of Santiago de los Cabelleros, in the north of the country, and publishes Boletin Médico, and has 65 members. Mention should also be made of the Dominican Medical Congress which has been in operation since 1844. There are a number of medical schools throughout the country, the main one being the Faculty of Medicine in the Universidad Autónoma de Santo Domingo, the university founded in 1538 making it the oldest university in the Americas. There is a Faculty of Health Sciences at the Pontificia Universidad Catolica Madre y Maestra; a Faculty of Medicine at the Universidad central del Este; a School of Public Health at the Universidad Eugenio Maria de Hostos, the Faculty of Health Sciences at the Universidad Nacional Pedro Henriquez Urena and at the Universidad Tencnológia de Santiago. From the mid-1970s, there has been a major government attempt to improve healthcare throughout the country. As a result, by the early 1980s, there were some 5,000 rural health clinics, health subcenters and some satellite clinics. Pharmacies are now common throughout the country. Doctors were required to serve for one year in remote or poor districts, but there were complaints that some poorly trained local health workers were not sufficiently trained in how to teach about health problems and disease prevention. To alert the public to health care concerns, and raise money for charity, the postal authorities of the Dominican Republic have issued large numbers of postage stamps to raise money for medical charities. See Also: Leukemia; Malaria.
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Bibliography. Congreso Médico Dominicano del Cen-
tenario 1844–1944: Memoria (Editorial El Diario, 1945); Frank Moya Pons, ed., El Ejercicio de la Medicina en la República Dominicana (Editora Amigo del Hogar, 1983).
Justin Corfield Geelong Grammar School, Australia
Double-Blinded Study A randomized clinical trial is regarded as the most highly influential study design that provides the highest level of evidence in the assessment of therapeutic outcome in medical science because it increases the validity of the study by eliminating potential studyrelated biases. However, to address potential studyrelated biases, various criteria have been established to maintain such high level of evidence and are largely based on the quality of the trial. Thus, trial quality is an imperative component in any randomized clinical trial. If steps are taken to reduce potential bias, the appropriately size and direction of the intervention effect can be properly obtained. One method utilized to decrease the risk of potential bias that could mislead the intervention effect is double blinding. Prior to the start of a randomized clinical trial, generation of the allocation sequence is imperative. In clinical trials, defining the manner as to how the allocation sequence is generated characterizes the type of study design as being randomized, quasi-randomized, or a controlled clinical trial. If the generation of the allocation sequence was unpredictable, the two groups being compared are associated with less confounds between them and a true measure of the treatment effect can be obtained. Compromising the allocation sequence could contribute to selection bias. According to the latest statement by the CONSORT group regarding improving quality trials in randomized clinical trial, allocation concealment represents the method utilized to employ the random allocation sequence. Such a method clarifies whether the allocation sequence was or was not properly concealed until interventions were assigned. Proper allocation concealment prevents the participants and the investigators from knowing in advance what treatment the subjects will receive. Therefore, both the participants
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and the investigators or the researcher responsible for the assessment of the intervention are both blinded (double blinding) to the treatment administered. Thus, adhering to allocation concealment by double blinding prevents influencing the subjects whether or not to enroll, adhere, or respond to a treatment regime; thereby, decreasing the risk of selection bias. In fact, a meta-analysis of various trials assessing if allocation concealment was inadequate/unclear or adequate indicated that trials with inadequate/unclear concealment yielded an overestimated treatment effect by 30 percent. The overestimated effect of lack of allocation concealment was twofold in comparison to the assessment of nonblinding versus blinding. Thus, allocation concealment is an imperative component to trial quality. The lack of double blinding can further affect the true estimate of the treatment and contribute to performance bias by the patient and detection/measurement bias by the study investigators. Knowledge of the treatment by the study investigators and subjects could affect the outcome being expressed and measured; thus, affecting the true effect of the treatment. In addition, not accounting for study withdrawals or dropout rates, also referred to as attrition bias, may contribute to unbalanced sample groups; thus, the effects of the treatment could be inappropriately estimated. Methodological quality in randomized clinical trials is largely based upon the proper execution of the generation and concealment of the allocation sequence, and the assessment of withdrawals or dropouts. However, to properly perform such methods or avoid deleteriously affecting certain study events that may influence the treatment effect, double blinding is paramount. SEE ALSO: Clinical Trial; Crossover Study; Prospective
Study; Randomized Clinical Trial.
Bibliography. Centre for Evidence Based Medicine,
“Levels of Evidence and Grades of Recommendations,” www.cebm.net/levels_of_evidence.asp (cited October 2006); Matthias Egger, Shah Ebrahim, and George Davey Smith, “Where Now for Meta-Analysis,” International Journal of Epidemiology (v.31, 2002); David Moher, et al., “Does Quality of Reports of Randomised Trials Affect Estimates of Intervention Efficacy Reported in Meta-Analyses?” Lancet (v.352, 1998); David Moher, Kenneth F. Schulz, and Douglas G. Altman, “The CONSORT Statement: Revised
Recommendations for Improving the Quality of Reports of Parallel-Group Randomized Trials,” Journal of the American Medical Association (v.285, 2001); David L. Sackett and Michael Gent, “Controversy in Counting and Attributing Events in Clinical Trials,” New England Journal of Medicine (v.301, 1979). Dino Samartzis, D.Sc., M.Sc., Dip. EBHC Harvard University and Erasmus University
Doula This word, coming from the Greek, refers to a woman who helps another woman, and in medical terminology has come to mean a person, often a woman, who is a nonmedical assistant in prenatal care, childbirth, and in looking after a baby soon after he or she has been born. Initially, the term in Greek generally referred to a slave, with the medical anthropologist Dr. Dana Raphael being one of the first to use the term when she referred to experienced mothers among the Ilocanos in Luzon in the Philippines helping mothers who had just had their first babies. Although relatives such as grandmothers and aunts often helped people in village societies where there were extended family networks, there was also heavy use of nonrelated women. The more experienced women were able to help with breastfeeding and newborn babies. As a result, this was largely dealing with the postpartum period (i.e., after birth), but gradually came to be used to refer to people who helped before birth as well. Work by medical researchers Marshall H. Klaus, John H. Kennell, and Phyllis H. Klaus, in their book Mothering the Mother (1993) showed the importance of the doula attending birth, and as a result, the process became more common in nonvillage societies such as in cities. Nowadays, doulas involved in labor support are trained in dealing with the emotional and physical comfort needs of women about to give birth. Some work attached to hospitals and clinics, but many, especially in third world countries, work on a semiformal or informal basis visiting expectant women, and those who have recently given birth, in their homes. Their role has often been increased to involve them with helping mothers in recovery after childbirth
Down Syndrome
by doing housework, preparing meals, and buying food when the woman has no other social network on which she can call. On another level, they can also advise authorities if the mother is having any problems before or after birth. Although doulas in the United States and Canada are not required to be certified, this is possible, and many have completed long courses and built up years of experience. They have also been involved in providing medical advice to mothers, drawing up exercise regimens during pregnancy, and giving advice on diet and other areas. They suggest positions that the woman can adopt during labor, which is particularly important when labor pains begin unexpectedly. They also advise the partner of the mother, can be present at birth, and help with immediate postnatal care. SEE ALSO: Pregnancy; Prenatal Care. Bibliography. Marshall H. Klaus, John H. Kennell, and
Phyllis H. Klaus, Mothering the Mother: How a Doula Can Help You Have a Shorter, Easier, and Healthier Birth (Addison Wesley, 1993); Amen Ness, Lisa Gould Rubin, and Jackie Frederick, Birth That’s Right for You: A Doctor and a Doula Help You Choose and Customize the Best Birth Option to Fit Your Needs (McGraw-Hill, 2006); Dana Raphael and Flora Davis, Only Mothers Know: Patterns of Infant Feeding in Traditional Cultures (Greenwood, 1985); Karen Salt, A Holistic Guide to Embracing Pregnancy, Childbirth and Motherhood: Wisdom and Advice from a Doula (Da Capo, 2002). Justin Corfield Geelong Grammar School, Australia
Down Syndrome Down syndrome, also called Down’s syndrome or trisomy 21, is a congenital disorder caused by the presence of all or part of an extra 21st chromosome. This gives people with Down syndrome 47 chromosomes, rather than 46. It acquired the name after the British doctor John Langdon Haydon Down (1828–1896) who first described it in 1866. The outward physical signs of the disorder, usually identified at birth, are a range of major and minor differences in body struc-
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ture, including an impairment of cognitive ability and also physical growth. The incidence of Down syndrome is estimated at 1 for every 800 to 1,000 births, and it was first recognized by John L.H. Down as a different form of mental retardation in 1866, and four years later he published his report “Observations” on an Ethnic Classification of Idiots which was published in the Clinical Lecture Reports from London Hospital. Down, born in Torpoint, Cornwall, was from a well-connected family—his great-great grandfather on his father’s side was the Roman Catholic Bishop of Derry, and the daughters of his sister married into the Darwin and Keynes families. Apprenticed to his father, a village apothecary, Down later went to work as a surgeon in London, and then to the Royal London Hospital and the Royal College of Surgeons, and became a Fellow of the Royal College of Physicians. He then worked at the Earlswood Asylum for Idiots in Surrey, and conducted much of his work at the Normansfield Asylum, in Teddington, Middlesex. His work used many terms such as mongolism which have long since stopped being used. There were various programs in the United States and also Nazi Germany involving identifying people suffering from Down syndrome, and then embarking on forcible sterilization, even though the cause remained unknown at the time, but was believed to be genetic. In 1961, some 19 prominent geneticists wrote an open letter to The Lancet in which they argued that the “mongoloid” description should be dispensed with, and the journal supported the new term Down’s Syndrome. Four years later, the delegate to the World Health Organization from Mongolia also objected to the term, forcing it to be dropped as an official term. The vast majority of the people who suffer from Down syndrome have a third chromosome which is associated with the chromosome 21 pair. This is why the disorder is often known as trisomy 21. There are also some 4 percent of sufferers who have an abnormal condition known as translocation. This is because in their bodies, the extra chromosome in the 21 pair has broken off and attached itself to another chromosome. In spite of much research into the cause of Down syndrome, the reason for the chromosomal abnormalities is still unknown although it has been shown that there is a higher incidence of Down syndrome in the offspring of women who
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give birth over the age of 35. Although statistically the number of Down syndrome births in children remains one in 800–1,000, the level of incidence in women who give birth over the age of 40 are one in 40. This has led to a range of tests which can be used to diagnose Down syndrome prenatally by checking for the presence of the abnormal chromosome in samples of the fetal cells which can be collected from the amniotic fluid. As well as an extra chromosome, there are many common physical features associated with Down syndrome. These involve having shorter limbs and neck, poor muscle tone, and a single transverse palmar crease. Those affected with Down syndrome also usually have an enlarged protruding tongue and lips, a sloping underchin, and eyes which have an almond shape, sometimes with an inner epicanthal fold, and low-set ears. There are also several problems such as a lower-than-average cognitive ability, at its most extreme involving moderate mental retardation, with some having severe mental retardation, as well as heart and kidney malformations. Some 40 percent of people with Down syndrome also tend to suffer from congenital heart disease. A number of notable people who suffered from Down syndrome include the German actor Bobby Brederlow, the New York actor Chris Burke, the Belgian actor Pascal Duquenne, the London actor Max Lewis, the Scottish film actress Paula Sage, the artist Judith Scott, and the Argentine singer Miguel Tomasin who sung with the avant-rock band Reynols. In addition, Stephanie Ginnsz, an actor, was the first with Down syndrome to take the lead part in a motion picture. Anne de Gaulle (1928–1948), daughter of the French politician Charles de Gaulle, suffered from Down syndrome; and there has been retrospective speculation that Charles Waring Darwin, son of the naturalist Charles Darwin, was also a sufferer from Down syndrome, evidence for this included the fact that Darwin himself conducted a correspondence with John Langdon Haydon Down. Modern healthcare has meant that many people with Down syndrome now live into adulthood, although those with major heart defects that cannot be subjected to corrective surgery die as children. Overall in the United States and western Europe, people with Down syndrome have a life expectancy of about 55, lower than normal adults, mainly because the condition means that they age prematurely. Many
have managed to be self-supporting to a large degree, being able to work in the home, or a sheltered workshop. With increasing tolerance in the wider society, and the greater awareness of Down syndrome, there is a much more general acceptance of the disorder and people with the disorder which was not the case even 30 years ago when many Western countries had asylums where sufferers would spend most of their lives. The work undertaken by the National Down Syndrome Society in the United States, which holds Down Syndrome Month each October, has been very effective in raising the profile of the disorder. The Down Syndrome Awareness Day is held on October 20 each year in South Africa. See Also: Degenerative Nerve Diseases; Healthcare, U.S.
and Canada.
Bibliography. Valentine Dmitriev, Early Education for
Children with Down Syndrome: Time to Begin (Pro-Ed, 2001); Margaret Farrell and Pat Gunn, Literacy for Children with Down Syndrome: Early Days (Post Pressed, 2000); Lynn Nadel and Donna Rosenthal, eds., Down Syndrome: Living and Learning in the Community (Wiley-Liss, 1995); Kristina Routh, Down’s Syndrome (Heinemann Library, 2004); Carol Tinget, ed., Down Syndrome: A Resource Handbook (Taylor & Francis, 1988); O. C. Ward, John Langdon Down, 1828–1896 (Royal Society of Medicine Press, 1998). Justin Corfield Geelong Grammar School, Australia
Drinking Water Drinking water is potable water or water that can be drunk or ingested by human beings. Water is a vital necessity for humans, without which they quickly die. The modern world is now rapidly growing more urban than rural and has a population projected to reach as high as 12 billion people by the year 2050. Securing potable water for all people is challenging the limited supplies. Although almost 70 percent of the surface of the Earth is covered by water in the world’s oceans and seas its saline content is too high for humans to drink. In addition, enormous amounts of water are locked
in ice caps in Antarctica, Greenland, and elsewhere. Other large quantities exist as water vapor in clouds or in the atmosphere. As a consequence, only about one or two percent of the water on the surface of the earth is fresh water available to people for drinking. Virtually all of the water that people drink begins as rain water. It is gathered by nature and is available in very unevenly distributed places. As a result, drinking water comes from the surface of the Earth or from relatively shallow sources underground. The most common natural water sources for potable water are springs, lakes, streams, rivers, rain collectors, underground aquifers, or other natural sources. The fresh water supplies needed as drinking water are competed for by agricultural, industrial, and recreational users. In addition, it is simply not possible to sustain the ecology if all of the waters of lakes and streams are diverted for human use. As a consequence, much of the water drunk by people in urban areas is purified water. This is water that may have been used previously for industry, sewage, agricultural runoff, or other polluting and toxic uses. However, the science of water purification is advanced to the level where water can be used and then purified as is moves down stream to the sea in city after city. The use of purification systems would be required even if the water supplies were not polluted by prior human use. There are a variety of diseases that come from microbes in water such as E. coli or typhoid that would imperil human health without purification. Modern water purification uses chemicals to purify the water people drink. Chlorine or other chemicals are used to kill germs. The use of chlorine or chlorine compounds carries a small risk because it is an element that is a known carcinogen. However, the risk is very small that chlorine may cause cancer versus the very high likelihood that large numbers of people will sicken and die from untreated water. Innovative ideas offered the sources for new supplies of fresh water have included melting frozen water and in Libya pumping water trapped in earlier geologic eras across the Sahara Desert to population centers. Another important possible source that has been offered is the used of desalination plants that can extract fresh potable water from sea water. There are currently problems associated with the used of desalination processes. The problems include the high amounts of energy that are required to de-
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salinate water and the quality of the water itself. If it is sterile water, that is just pure evaporated water then it will taste flat and it will also be lacking in minerals that are found in natural water. Strictly speaking, all water on Earth is mineral water. As rain falls, it can collect minerals from the air. When it hits the ground, it will usually absorb some combination of minerals from rocks and soils it passes through. The minerals in the water people drink is one source of the minerals that are dietary supplements needed by people. Iodine is just one such mineral. The recognition that minerals are important to health has historically led people to seek out mineral springs. There, especially at hot springs, people have drunk and bathed in the mineral waters. There are also mineral springs that bottle and sell their waters around the globe. Famous bottle mineral waters include Apollinaris from Neuenahr, Germany; Badoit from Saint Galmier, France; Bru from Chevron, Belgium; Caddo Valley water and Mountain Valley water from near Hot Springs, Arkansas; Evian from Evian-les-Bains, France; Fiuggi from Italy; Gerolsteiner Srudel, from Gerolstein, Germany; Mattoni from Kysebel-Kyselka, Czech Republic; Perrier from Vergeze, France; Poland Water from Poland, Maine; San Pellegrino, from Bergamo, Italy; Vittel water from Vittel, France. Some of these bottle mineral waters are “sparkling” water, that is, they contain carbon dioxide that is found in the water at the spring from which it is drawn. Other commercial mineral waters are “still” mineral waters, that is, they do not have a significant gaseous content. The mineral content of mineral waters varies. There are springs that contain sweet-tasting limestone minerals. Other springs contain concentrations of alkali and can be unpleasant in tastes, but desired for bathing. In some places sulfur in the water gives it a rotten egg smell, which is however often desired as a natural mineral water for drinking and bathing in a spa. Some commercial mineral waters such as Apollinaris have a high mineral content. Others such as Poland Water from Maine have a low mineral content. Many claims have been made about the health benefits that come from drinking these mineral waters. Europeans have long made a variety of health claims about their mineral waters. In the United States, the Food and Drug Administration which supervises such claims has a very tough policy that requires rigorous scientific proof for such claims before they can be made.
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There are hundreds of brands of bottled water in the United States. Some are “spring” water, that is, bottled from some spring, but not necessarily at the spring itself. All mineral waters that are sold must be bottled at the source. Most bottled water sold in the United States is bottled tap water. For example, it is possible to purchase Miami tap water from nationwide grocery chain stores. There is nothing impure about these many brands of bottled water; however, many purchasers are misled into thinking that they are drinking spring water rather than purified water. In addition, some commercially available bottled water is sold as “sparkling” water; however, the carbon dioxide fizz has been inserted from industrially produced carbon dioxide. A test that can be used is if the water freezes without any bubbles, it is distilled water. If it has a white deposit at the center, it is hard water. It if has numerous bubbles, it is cloudy and is soft water. Historically, people were able to drink fresh water that was untreated from springs, streams, or other sources. This can still be done in some remote locations such as Alaska, northern Canada, or Patagonia or the Andes in southern Chile. Fresh untreated water is still consumed by great numbers of people around the Earth from springs or mountain streams. In addition, fresh water that is untreated but pure
The fresh water supplies needed as drinking water are in competition with agricultural, industrial and recreational uses.
enough to drink straight out of the ground is available from water wells. Large numbers of people in the United States or around the world get their drinking water from wells. Drilling or digging holes into the ground to get water is an ancient practice that has been able to reach everdeeper sources of ground water through modern well drilling technology. ��������������������������������� Hand dug shallow wells are wells dug with hand tools during a dry season to the water table below. In many cultures, a man or woman called a dowser in the United Sates is believed to have special powers for locating pure water has been summoned to identify the place where the new well will be dug. Using a “divining or witching” rod, they will walk an area until the diving rod shows them the best place for water. Such practices go back for thousands of years. Claims made for the success of dowsers are not universally accepted. For thousands of years, shallow hand-dug wells have been a major source of water for people. Wells are considered shallow if they descend to less than 50 feet in depth. Shallow wells reach either the water table (water table wells), which is the level at which the soil is saturated with water, or a well may be dug through an impermeable layer of clay or rock to an aquifer, which is a permeable layer of either soil or rock through which water flows but which is capped by at least one impermeable layer (aquifer wells). The well is a hole that is dug to the place where water is found and then some deeper. The bottom of the well is filled with clean gravel. Stones or burnt bricks or some other solid material is used to form the sides of the well. The sides keep the soil from collapsing into the well and ruining it. In modern water wells, the casing of the sides is often cement. The water table rises in the well and reaches greater heights during wet seasons. For millions of people in rural areas of the world, and especially in the third world shallow water wells supplying water to their village means that they do not have to share a water hole with wild beasts. The water will therefore not be polluted with their droppings or contaminants. Well water is healthier to drink from than is a water hole as long as the well is properly capped and ground water with pollutants does not sweep into it. In many third world countries, shallow wells are still being dug and used by people as a substitute for
Drinking Water
sharing a waterhole with wild animals. These wells are dug at villages in the bush that are remote and can be reached only by a beaten track. Wells can be drilled with machinery as well as dug with hand tools. The drilling of wells began in the mid-1800s. The well diggers of that time adopted a machine that drove or “pounded” a bit into a hole into the ground. The bit was attached to a cable and was dropped repeatedly into the drill hole. The cable tool drilling method was slow and inefficient. It was replaced by the rotary drilling method in the 1900s. The rotary drill bit is made of tungsten steel or other tough metals. Attached to a drill pipe, it is rotated to grind up rock that it encounters in drilling the well. It is operated inside of a larger pipe which is regularly flushed with water to cool the drill bit and to wash out the cuttings, dirt, gravel, and sand. The outer pipe acts as a wall and prevents the drill hole from collapsing which would block the drill hole. As the drilling progresses, the well driller keeps an accurate log of the depths of the drilling and the levels at which water is encountered. Millions of other rural homes on other continents are supplies with potable water from water wells. Today the vast majority of wells used in the United States are drilled wells. Probably half of the households in rural America used well water. The number around the world is enormous. Obtaining adequate potable water supplies is a growing global problem. Diseases from a range of pathogens including parasites plague millions in third world countries. In many desert and semiarid areas the growth of populations is taxing all available water supplies. The carrying capacity of an ecological system is very much tied to the availability of water. For perhaps as many as a billion people on the globe, potable water, safe for humans to drink, is difficult to obtain. As a consequence, the threat to the health of large numbers of people is grave. Standards for water quality are set around the world by many governmental agencies. The World Health Organization sets international drinking water standards. In the United States, the Safe Drinking Water Act of 1974 (SWDA) (42 U.S.C. 300j-9(i) requires the Environmental Protection Agency to set national standards. It also allows water treatment employees the right to report violations as protected whistle-blowers. Their reporting of water treatment
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standards violations would go to the Occupational Safety and Health Administration (OSHA). Tests for water safety include tests for bacterial contamination from pathogens like Escherichia coli (E. coli). The laboratory examination of water samples will reveal the presence of sewage that can cause serious health threats. The health of an individual and of a country’s population as well is an indicator of their capacity for productive work. The wealthier an individual or a country is, the greater its capacity to obtain safe drinking water. The World Health Organization estimated that in the low- and middle-income countries of the world, as many as a billion people do not have access to safe water. In addition, proper sanitation facilities are not available for another one billion people. In a great number of countries, a lack of water is not the problem instead, it is the absence of adequate water treatment facilities that keeps drinking water supplies from being safe. Even in water, rich countries the threat to the safety of drinking water, especially from tap water, are pathogens or industrial pollutants. The main reason for poor access to safe water is the inability to finance and to adequately maintain the necessary infrastructure. Overpopulation and scarcity of water resources are contributing factors. SEE ALSO: E. Coli Infections; Food and Drug Administra-
tion (FDA).
Bibliography. American Water Resources Association
Staff, Water Quality and Treatment Handbook (American Water Works Association, 1999); Joshua I. Barzilay, Winkler G. Weinberg, and J. William Eley, Water We Drink: Water Quality and Its Effects on Health (Rutgers University Press, 1999); Michael D. Campbell and Jay H. Lehr, Water Well Technology: Field Principles of Exploration, Drilling, and Development of Ground Water and Other Selected Minerals (McGraw-Hill, 1973); Jerry Dennis, The Living Great Lakes: Searching for the Heart of the Inland Sea (St. Martin’s Press, 2004); Michael Detay, Water Wells: Implementation, Maintenance and Restoration (Wiley, 1997); R. Allan Freeze and John A. Cherry, Groundwater (Prentice-Hall, 1979); Ulric P. Gibson and Rexford D. Singer, Water Well Manual: A Practical Guide for Locating and Constructing Wells for Individual and Small Community Water Supplies (Premier Press, 1971); P. Howsam, Water Wells—Monitoring,
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Maintenance, Rehabilitation: Proceedings of the International Groundwater Engineering Conference Cranfield Institute of Technology (Taylor & Francis, 1990); Brian Kronvang. Jadran Faganeli and Nives Ogrinc, eds.. Interactions Between Sediments and Water (Springer-Verlag, 2006); Gordon A. McFeters, ed., Drinking Water Microbiology (Springer-Verlag, 1990); Nutrient Management in Agricultural Watersheds: A Wetlands Solutions (Wageningen Academic Publishers, 2005); National Academies Press, Identifying Future Drinking Water Contaminants (National Research Council, 2000); Kerwin L. Rakness, Ozone in Drinking Water Treatment: Process Design, Operation, and Optimization (American Water Works Association, 2005); Steven Schwartz, The Book of Waters (A&W Visual Library, 1979); Frank R. Spellman, Steve Strauss, and Joanne Drinan, Drinking Water Handbook (CRC Press, 1999); James M. Symons and Bradley Lee, Jr., The Drinking Water Dictionary (McGraw-Hill, 2001). Andrew J. Waskey Dalton State College
Drug Abuse Drug abuse refers to repetitive, nonmedical use of any substance that is detrimental to the physical, psychological, or social health of the user and negatively impacts the welfare of others. One of the most complex and widespread epidemics in the world, drug abuse cuts across economic, social, ethnic, gender, and age strata and affects people in developed and underdeveloped countries alike. Drug abuse poses significant threats to the health, social and economic stability, and functionality of families, communities, and nations. The World Health Organization indicated in the 2002 World Health Report that there are 2 billion alcohol users, 1.3 billion smokers, and 185 million drug users, and drug abuse accounted for an estimated 8.9 percent of deaths worldwide. Yet, that estimate does not take into consideration deaths indirectly related to substance abuse, such as suicide, cancer, accidents, or violence, signifying that drug abuse contributes to far more global illness and death than the statistics reveal.
Drugs Drugs fall into one of three categories: legal or licit, prescription, and illicit. They include, but are not limited to, the following substances: alcohol, cannabinoids (e.g., marijuana, hashish), cocaine, hallucinogens (e.g., LSD, mescaline), inhalants (e.g., toluene, acetone), opioids (e.g., heroin, morphine, methadone), sedative hypnotics (e.g., barbiturates, nonbarbiturate sedatives, benzodiazepines), stimulants (e.g., amphetamines, anorectic agents, preparations of Catha edulis, ecstasy), and tobacco. All drugs are characterized by the ability to change the consciousness, mood, senses, or thinking patterns of the user. Legal or licit drugs, like alcohol, cigarettes, and even caffeine, do not induce harmful effects when use is limited; however, when such drugs are taken in excess, they have potentially psychoactive and addictive effects. Prescription drugs are considered helpful, not harmful, when taken under the guidance of a licensed medical practitioner; however, when abused, they are considered detrimental to individual health and well-being. Substances deemed illicit either by international standards or local legislature are generally deemed more problematic with the potential to greatly inhibit the welfare of individuals and their communities. There is much debate about the distinction between drug use, drug abuse, addiction, and dependence. The terms are often interchangeable, although they have subtly different implications in the realms of public health, mental health, law, and the mass media. Here, drug use indicates neither the problematic nor habit-forming use of any substance. Drug abuse results from the complex physiological and psychological interactions of the substance, the individual, and social and environmental factors. It refers to a pattern of self-destructive behavior of repeated use of drugs that fall outside the realm of accepted medical or social norms, despite negative health and social consequences. Drugs may elicit either physical or psychological dependence or both. Drug dependence is a physical phenomenon caused by the biochemical activity of repeated use of the drug in the body and is characterized by marked physical disturbances when the drug is withdrawn. The dependence potential of a substance is determined by its pharmacological properties, mode of administration, and frequency of use. Psychological dependence, labeled addiction, describes the overwhelming craving or compulsion a
user feels to use the drug(s) to function or survive. The attainment and use of the drug often override the individual’s other personal, social, and/or occupational responsibilities, leading to a pattern of selfdestructive and socially destructive behavior. Drug addiction tends to evolve during periods of abuse and may or may not involve a chemical dependency. Like drug abuse, drug addiction is regarded as a chronic mental health disorder that is precipitated by a complex combination of genetic, environmental, biological, and pharmacological factors. Most drugs of abuse generate physical dependence and all induce a psychological dependence. Interestingly, addiction may occur without dependence, but the converse is not necessarily true. For example, inhalants and LSD do not mediate a physiological addiction, yet the individual seeks the sensations experienced induced by the drug and continues use. Conversely, some drugs create a physical dependence, such as chlorpromazine, but are not abused due to the lack of development of a psychological dependence or addiction. Risk Factors Drug abuse is not a singular problem involving a specific substance, but rather a multitude of problems resulting from the abuse of a multitude of substances. The complexity of the problem renders the identification of the causal pathway complex and difficult to determine. It is not entirely understood why some people use drugs in a controllable, predictable, and nondestructive manner, while others develop addiction and dependence. There exists a gamut of underlying physical, psychological, and environmental factors that contribute to drug abuse, yet there is no clear causal pathway from any single risk to the eventual outcome of drug abuse. Physical factors include a genetic disposition to addiction, the inability to manage stress and emotions, and the age of initiation of drug use, with those starting at a younger age more likely to develop drug abuse problems. Psychological factors relate underlying mental health conditions and personality characteristics to the propensity to abuse drugs. Environmental factors range from the influence of the family to the norms of society. Family instability, family members suffering from drug abuse, and domestic or societal violence all correlate to the potential of an individual to develop a drug abuse disorder. Poverty
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and unemployment may contribute to the stress of a family or an individual to satisfy their quality of life and lead them to use and abuse drugs. Organized crime, the increased availability of drugs, a culture of drug use, and even the surge of medical prescription correlate to an outcome of drug abuse. Again, there is not clear causal pathway from any one risk factor to the eventual outcome of drug abuse: There are individuals who possess a number of risk factors and never develop abuse, just as there are individuals with few risk factors who ultimately exhibit symptoms of abuse. associated Health Problems Drug abuse relates directly and indirectly to an array of causes of morbidity and mortality. The inconsistency of epidemiological methodology and the lack of data from several countries inhibit a comprehensive review of the total global burden of disease instigated by drug abuse. The contribution of drug abuse to morbidity and mortality rates is frequently underestimated because It may be one several contributing factors to the outcome of illness. The extent of health problems resulting from drug abuse depend on the type(s) of substance(s) abused, the mode of administration, the frequency of use, the age of initiation, and the underlying genetic factors of the individual. The health problems derived from drug abuse can be categorized into three broad categories: 1.) physical problems, 2.) psychological/psychiatric problems, and 3.) social and economic problems. Physical Problems Drug abuse is related to a plethora of chronic and acute health sequelae. Abusing drugs holds the potential to cause morbidity in nearly every organ system in the human body. It increases a person’s risk for cardiovascular hypertension, stroke, coronary artery disease, gastrointestinal and biliary ulcers, pancreatitis, cancer of the gastrointestinal tract and lungs, cirrhosis of the liver, chronic obstructive pulmonary artery disease, neuropathy, vitamin deficiencies, hematopoietic anemia, and death by overdose. Furthermore, trauma accidents in air, land, or water including car crashes, drownings, fires, electrocution, and injury from falling are common when an individual is under the influence of drugs. The risk of contracting communicable and infectious diseases rises with drug use. Alcohol, opioids,
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and cannabinoids have been proven to suppress the immune system by markedly decreasing lymphocyte proliferation, antibody formation, and cytotoxic activity. As a result of decreased immune function, susceptibility to infectious diseases increases. Drug users face a greater susceptibility to bacterial, viral, and fungal etiologic agents that cause diseases such as syphilis, community-acquired pneumonia, herpes, hepatitis, and human immunodeficiency virus (HIV)/AIDS. In addition to immunosuppression, injection drug users (IDUs) put themselves at further risk for blood-borne infections such as hepatitis and HIV/AIDS when sharing needles or using contaminated paraphernalia. Drug abuse has been a factor in the spread of HIV/ AIDS and other sexually transmitted diseases as it correlates with increased sexual risk taking. Intoxication with alcohol, cannabinoids, cocaine, inhalants, opioids, or stimulants lessens the user’s sense of social inhibitions and paves the way for promiscuous behaviors. In short, drug abuse increases the susceptibility of infection by immunomodulation and the exposure to infectious agents by increasing the impulse to engage in harmful health behaviors. In eastern Europe and Russia, injection drug fueled the transmission of HIV/AIDS and shaped the epidemic in the region. Unplanned pregnancies are not uncommon with drug abusers as they have relatively more sexual partners and more pregnancies than nonusers. With the increased potential to contract an infectious disease, drug-abusing mothers bear a greater probability of transmitting infectious diseases to their babies. Mother-to-child transmission plays a significant role in the spread of diseases such as HIV/AIDS and syphilis, particularly in underdeveloped countries where HIV/AIDS education and healthcare are inadequate. Furthermore, all drug use—from tobacco and alcohol to cocaine and opioids—during pregnancy causes mild to serious fetal developmental defects and sometimes death. Psychological/Psychiatric Problems The American Psychiatric Association’s Diagnostic and Statistical Manual of Mental Disorders (DSM) classifies substance abuse as a mental health disorder. Drug abusers develop a range of short- and long-term mental health disorders as well as exacerbate any previous mental health conditions. The effects of many drugs cause, as well as mimic, psychiatric disorders such
as anxiety, paranoia, delusions, depression, or mood changes. Depression is the most notable symptom of drug abuse. Depression affects an individual’s quality of life and physical health as well as the health and well-being of those around them. There is also a strong relationship between drug abuse and suicidal ideation, attempts, and acts, which are mediated by depression. Social and Economic Problems The social and economic repercussions of drug abuse reach far beyond the individual, affecting families, communities, and nations. Family and loved ones of addicts usually support the greatest financial and emotional onus produced by drug abuse. The physical and psychological illnesses resulting from drug abuse create excess tension in the household and ultimately undermine the stability of the family. Further discord disrupts and sometimes destroys households with the combination of the economic need of the addict to maintain the drug supply and the financial demands of healthcare for subsequent illnesses. Family members who care for addicts report a decreased quality of life and an increase in mental health disorders, including depression. Druginduced memory lapses, impulsive behaviors, and a preoccupation with acquiring and using drugs strain the social relationships of drug abusers. The children of addicts suffer in myriad ways, as they are deprived of their physical, emotional, and educational needs due to irresponsible parenting. Subjected to a climate of drug abuse, a risk factor in initiating drug use, children of addicts are more likely to become addicts, thereby driving the vicious cycle of drug abuse from generation to generation. In countries with social welfare systems, the children of addicts frequently end up in foster homes, shelters, or correctional facilities. In countries with little social infrastructure, the children of addicts may end up living with incarcerated parents in jail, abandoned, or living on the streets. On the streets or in parentless households, children are deprived the basic human rights of food, shelter, and education. Moreover, they become more vulnerable to sexual and labor abuse and exploitation. Communities feel the impact of drug abuse in the forms of crime, violence, and a loss of economic productivity. Drugs and alcohol are associated with crimes ranging from petty theft to rape and homicide. Some crimes, like thefts, are motivated by the addicts’ need
for funds to support their drug abusing habit. Other crimes are committed under the influence of drugs when moods, impulses, and perceptions are tainted by intoxication. The direct relationship between drug abuse and crime mean greater local and national expenditures on crime prevention and managing the criminal justice system. The HIV epidemic coupled with the increase of crimes and incarcerations attributed to drug abuse and trafficking continue to propel the cost of drug abuse prevention and treatment to spiral upward. In the workplace, drug abuse leads to significant declines in productivity, which, depending on the extent of the drug abuse problem, triggers public health repercussions on national and international levels. For example, unemployment and homelessness may result from poor job performance. The local communities and national economies—not the drug abusers—bear the brunt of the burden of subsequent healthcare, legal, and educational costs. Global Burden of Drug Abuse Few, if any, countries are immune to the deleterious effects of drug abuse. Worldwide, the regulation and treatment of drug abuse are the cause of staggering economic and social costs, permeating all cultural and geographic boundaries. Few comprehensive international studies have been undertaken to measure the global costs of drug abuse to society. The World Health Organization is the only organization working to document and control all drugs regardless of their legal status. As previously mentioned, in its 2002 World Health Report, it found that 8.9 percent of deaths worldwide were directly attributable to drug abuse, In other words, tobacco and alcohol accounted for 4.1 percent and 4.0 percent, respectively, of the burden of ill health in 2000, while illicit drugs accounted for 0.8 percent. With globalization bringing about improved transportation and communication capacities around the globe, people, capital, and goods are able to move more easily and more frequently across borders than was previously the case. While the trend in globalization has facilitated the growth and development of legitimate international businesses, it has also paved the way for drug producers and traffickers to organize themselves on a global scale. According to the United Nations Office on Drugs and Crime, the value of the global illicit drug market in 2003 was estimated
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at $13 billion at the production level, $94 billion at the wholesale level, and at $322 billion based on retail prices, taking seizures into account at all levels. The drastic increase in value of drugs as they move from production to market illustrates the economic extent of the business and the demand for the product. While those involved in the upper echelons of the drug trade reap the economic benefits, society around the globe pay the price. The Office of National Drug Control Policy estimated that the costs of drug abuse incurred by government and society between the years of 1992 and 2002 were $15.8 billion for healthcare, $128.6 billion for lost productivity, and $36.4 billion for law enforcement and social welfare. Additionally, countries must deal with the fact that many of the funds earned by illegal trafficking are siphoned into gangs and terrorists groups to support illegal and violent activities. In fact, much of the violence attributed to drug abuse is associated with its illegal trafficking and sales and with its biological effects on the abuser. The comorbidity of drug abuse with other social problems suggests that addressing greater social problems, like crime, poverty, or the development of health educational infrastructure, may mitigate the negative health, social, and economic impacts of drug abuse on individuals and communities. Control and Prevention The World Health Organization and individual nations strive to prevent and reduce the negative health and social consequences of drug abuse through public health programming and policy. Public health programs try to inform the public of the perils of drug abuse and provide alternative activities for youth to prevent the initiation of drug use. Taxation of legal drugs such as alcohol and tobacco has proven to be an effective means of countering the economic drain due to drug abuse as it generates enormous revenue for the government and allows for employment opportunities within the industries. The principal manner to control drug abuse has been to make drugs illegal and enforce the control of production, distribution, and use around the globe. The drawback is that the majority of costs due to drug abuse arise from police, legal, and incarceration expenses along with lost productivity of incarcerated criminals and of victims of crimes. Furthermore, as seen with prohibition in the early 20th-century Amer-
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ica, an illegal or black market is harder to uncover, regulate, and control. These issues have prompted some social and political groups to lobby for the legalization of drugs. Proponents for the legalization of drugs argue that eliminating the black market and creating stricter business regulation for drug handlers would minimize on the crime associated with the current black-market style of drug trafficking. Some researchers believe that the economic costs associated with drug abuse can be reduced by legalizing nowillegal drugs. Legalization would allow for taxation as with alcohol and tobacco to augment government income and help cover the costs of the damaging health and economic sequelae of drug abuse. Opponents to the legalization of drugs argue that legalizing drugs would only increase drug production, supply, and drug abuse, further intensifying the heath, social, and economic problems linked to drug abuse. They also assert that the legalization of drugs would send a message of approval of drug abuse to youth, which may stimulate a more severe epidemic in the future. Countries with indigenous populations encounter other challenges in policy development. They struggle to reconcile the conflicting modern-day political, social, cultural, and medical viewpoints on drug abuse with the historical and cultural significance of drug use embedded in the traditions of indigenous groups. Treatment and Rehabilitation There exists neither a quick solution nor cure for drug abuse. All treatment programs, aside from harm reduction, have a twofold purpose: 1.) helping individuals live without the use of drugs and 2.) reintegrating affected individuals into society to function as productive members. Treatment is a continuing process that employs medical or behavioral therapies or both. Medical therapies are available for some drugs, including opioids and tobacco. They offer help in overcoming the physical symptoms of drug withdrawal during detoxification by mimicking some of the effects of drugs in the body. Medical therapies are also available to help reestablish normal brain function and prevent relapses later on in the rehabilitation process. Behavioral programs aim to engage the recovering addict in the rehabilitation process and to motivate, condition, or teach them to change harmful attitudes and behaviors. These programs are usually religious or socially based and incorporate group and individ-
ual counseling as well as self- or mutual-help groups. Most programs require a residential stay in a clinic or in a therapeutic community, where the recovering addict has the opportunity to focus on rehabilitation without the distractions, stresses, and temptations of everyday life. Popular around the world are Alcoholics Anonymous and Narcotics Anonymous, 12-step rehabilitation programs incorporating peer support networks and individual and group counseling. Nearly all rehabilitation programs promote absolute abstinence from drugs for life. Accordingly, no treatment program asserts to cure drug abuse; rather, they enforce the fact that rehabilitation requires a constant, active effort to sustain rehabilitation and sobriety. Comparatively, harm reduction represents a major paradigm shift in the treatment of drug abuse. Harm reduction asserts that drug abuse will persist despite all efforts to curtail it. Under this presumption, harm reduction seeks to minimize the harmful effects of drug use and abuse, rather than promoting abstinence like treatment programs. Such methods and strategies are becoming more common in public health programs striving to minimize the spread of HIV among IDUs. One example of harm reduction strategies employed to achieve this goal are needle exchanges, where needles are distributed or exchanged, free of cost, to IDUs to reduce the chances of transmission by sharing contaminated needles. SEE ALSO: AIDS and Infections; Alcohol and Youth; Al-
coholism; Drug Industry; Mental Health; Pregnancy and Substance Abuse. Bibliography. American Psychiatric Association, Diag-
nostic and Statistical Manual of Mental Disorders DSMIV-TR 4th Edition (Text Revision) (American Psychiatric Publishing, 2000); Herman Friedman, Susan Pross, and Thomas W. Klein, “Addictive Drugs and Their Relationship with Infectious Diseases,” FEMS Immunology & Medical Microbiology (v.47/3, 2006); Hamid Ghose, Drugs and Addictive Behavior: A Guide to Treatment (Cambridge University Press, 2002); Zili Sloboda, ed., Epidemiology of Drug Abuse (Springer, 2005); World Health Organization, Alcohol in Developing Societies: A Public Health Approach (World Health Organization, 2002). Katherine Schlaefer, M.P.H. amino al Cambio
Drug and Medical Device Safety For decades, drug and medical device safety has been, and continues to be, an important global health issue. Several major drug-related tragedies have demonstrated the need for effective drug and medical device safety systems. Clinical trials and postmarketing surveillance help to ensure some degree of safety among marketed medical interventions. Recent safety concerns substantiate the need for improved systems to ensure drug and device safety. a Global Health Concern In 1961, the world experienced the infamous “thalidomide disaster.” Thalidomide was a prescription drug marketed in several countries to alleviate morning sickness in pregnant women. Shortly after its launch, health practitioners observed a dramatic increase in phocomelia, a rare birth defect in which children are born without limbs. Epidemiological studies demonstrated that phocomelia was associated with exposure of the fetus to thalidomide. Despite national and international efforts intended to prevent and mitigate future drug-related tragedies, such as the establishment of the World Health Organization (WHO) Programme for International Drug Monitoring, drug safety issues persist into the 21st century. In 2004, the COX-2 inhibitor rofecoxib was removed from the markets in many countries due to serious safety concerns related to potentially fatal cardiovascular complications. Two years later, in September 2006, the Institute of Medicine (IOM), a not-for-profit subsidiary of the National Academies in the United States, which exists to provide science-based advice on matters of biomedical science, medicine, and health, published a landmark report on drug safety—The Future of Drug Safety: Promoting and Protecting the Health of the Public. Drug Development and Approval The IOM report, and the publicity surrounding it, underscores the importance of drug safety to public health. Each year, more and more drugs are introduced to the world market. Bringing a new drug to market involves a complicated, time-consuming, and costly research and development process. A major
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component of the development and approval process is a three-phase clinical study period in which an investigational new drug is tested in human subjects to assess its safety and efficacy. Phase 1 studies involve the initial introduction of an investigational new drug into healthy human volunteers and are designed to determine the metabolic and pharmacologic actions of the drug in humans and the side effects associated with varying doses. Phase 2 includes early controlled clinical studies conducted to obtain preliminary data on the effectiveness of the drug in patients with a particular disease or condition. These studies are typically well-controlled, closely monitored, and conducted in a relatively small number of patients and can help determine the common short-term side effects and risks associated with the drug. Phase 3 studies are basically expanded Phase 2 studies that are performed after preliminary data suggesting effectiveness of the drug are obtained, and are intended to gather additional information about effectiveness and safety that is needed to evaluate the overall benefit–risk relationship of the drug. PostMarketing Surveillance Even though one of the primary objectives of the drug development and approval process is to ensure that drugs are safe before marketing commences, conventional randomized, controlled trials used in clinical testing are often inadequate to detect and assess rare adverse events associated with a new drug. Since these studies are conducted in relatively small numbers of people, rare adverse events associated with a new drug may not be detectable until more people are exposed to it. To identify safety issues associated with a newly marketed drug, postmarketing surveillance methods, or pharmacovigilance, have developed. Pharmacovigilance is a process of continual monitoring for deleterious effects of marketed drugs. In practice, pharmacovigilance refers almost exclusively to spontaneous reporting systems. These systems, such as the MedWatch system maintained by the Food and Drug Administration (FDA) in the United States, allow regulators and healthcare providers to report adverse drug reactions to a central agency (e.g., FDA), which can then combine reports from many sources to produce a more informative drug safety profile.
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Medical Device Safety Like drugs, medical devices are subject to safety evaluation. The term medical device covers a broad range of entities typically including instruments, apparatuses, machines, implants, and contrivances intended for use in diagnosing, treating, or preventing disease. Specific examples include electronic blood glucose monitors, pacemakers, contact lenses, and hearing aids. The FDA recognized three classes of medical devices based on the level of control necessary to assure the safety and effectiveness of the device: general controls, general controls with special controls, and general controls and premarket approval. The amount of information that must be obtained prior to marketing varies by class according to the potential for risk posed by the device. Once a device is marketed, sponsors must follow good manufacturing practices and monitor the safety of their products. Devices are also subject to inspections by appropriate regulatory agencies. SEE ALSO: Clinical Trial; Food and Drug Administration
(FDA); Food Safety; Pharmacoepidemiology; Randomized Clinical Trial. BIBLIOGRAPHY. Committee on the Assessment of the US
Drug Safety System, et al., The Future of Drug Safety: Promoting and Protecting the Health of the Public (The National Academies Press, 2006); Food and Drug Administration, “U.S. Food and Drug Administration Homepage,” www.fda.gov (cited October 2006); Brian L. Strom, Pharmacoepidemiology (Wiley, 2005); “WHO Programme for International Drug Monitoring,” www.who-umc.org (cited October 2006).
ute illegal substances. The DEA also works with state, local, and international officials to bring individuals and organizations to justice whenever they violate drug enforcement laws in those jurisdictions. The DEA is headquartered at 2401 Jefferson Davis Highway, Alexandria, Virginia 22301. Information on the agency is available by telephone (1-202-307-1000), through the 21 regional offices, and on the internet (http://www.dea.gov/). The DEA’s major responsibilities include investigating charges against suspected violators, preparing cases for prosecution by appropriate individuals; managing the national drug intelligence program; implementing the seizure and forfeiture of assets proved to be associated with drug trafficking; enforcing the sections of the Controlled Substances Act that deal with the manufacture, distribution, and dispensing of legally produced controlled substances; working with governments at all levels to stop violators who perpetrate crimes across borders; and implementing measures to control illegal substances through such activities as crop eradication, crop substitution, and training of foreign officials engaged in drug enforcement. The DEA also works with the secretaries of state and U.S. ambassadors to coordinate international drug enforcement activities and serves as a liaison in the area of drug enforcement between the United States and the United Nations, Interpol, and other international crime-fighting agencies.
Joshua J. Gagne, Pharm.D. Jefferson Medical College
Drug Enforcement Administration (DEA) In compliance with federal law, the United States Drug Enforcement Administration (DEA) is responsible for the oversight of all controlled substances. DEA has the authority to levy federal and/or civil charges against violators who grow, manufacture, or distrib-
DEA and FDA agents caught e-traffickers who used websites to illegally distribute controlled substances in Operation “Cyber Chase.”
Dyslexia
In 1915, the Bureau of Internal Revenue was assigned the responsibility of drug enforcement. With the passage of the Eighteenth Amendment in 1919, Prohibition expanded the scope of the Bureau’s activities as speakeasies sprang up around the country, and as moonshining activities expanded in rural areas. Organized crime was an offshoot of Prohibition, and DEA agents were engaged in fighting crime on a major scale. In 1968, President Lyndon B. Johnson introduced Reorganization Plan 1, combining the Bureau of Narcotics (FBN), which, as an agency of the Treasury Department, had been responsible for controlling marijuana and narcotic drugs, and the Bureau of Drug Abuse and Control (BDAC), which operated under the auspices of the Department of Health, Education, and Welfare to control depressants stimulants, and hallucinogens. The new agency became the Bureau of Narcotics and Dangerous Drugs (BNDD), operating under the Department of Justice to enforce all federal laws on controlled substances. In 1973, as part of the global war on illegal drugs, President Richard Nixon introduced Reorganization Plan 2, consolidating all federal drug enforcement responsibilities into the current DEA. The decision to consolidate drug enforcement responsibilities was in large part a reaction to the emergence of the drug culture that had become a permanent element of American society. Those responsibilities took on new meaning in the latter decades of the 20th century when schools became a frequent target of drug dealers, many of whom were students themselves. DEA data indicate that the number of people using illegal drugs grew from 4 million in 1960 to 74 million in the first years of the 21st century. During that same period, international drug-trafficking syndicates, such as those from Colombia and Mexico, made the DEA’s efforts to control illegal drugs even more difficult. Between 1960 and 1974, the DEA opened offices in 43 foreign countries, covering the globe from Paris to Hong Kong to Mexico to the Philippines to Canada to the Netherlands. In 1970, Congress passed the Controlled Substances Act as Title II of the Comprehensive Drug Abuse Prevention and Control Act, consolidating 50 separate laws into a single package to control narcotic and psychotropic drugs. Substances were classified according to their potential for abuse and addiction and whether they had a legitimate medical value. In amended form, this legislation continues to provide the framework for the DEA classification of drugs. In 1971, the Diversion
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Control Program established measures for dealing with the practice of diverting legal drugs such as amphetamine and methamphetamine into illegal channels. In 1973, the DEA Intelligence Program was established to provide up-to-date information that allowed the newly established DEA to track and access criminal activity for use in identifying and prosecuting violators and in establishing long-term strategies. The National Narcotics Intelligence System was also set up as the first national law enforcement automated index. The following year, the Drug Abuse Warning Network (DAWN) was founded to generate data on the scope of drug abuse in the United States. Over time, the DEA added additional capabilities in aviation, training, technologies, and laboratories. In the late 1990s, DEA agents began devoting a good deal of attention to monitoring synthetic drugs such as ecstasy, and the potential use of illegal substances by terrorists became a focus of increased activity after the attacks on the United States on September 11, 2001. See Also: Drug Abuse; Drug and Medical Device Safety. Bibliography. Drug Enforcement Administration, www.
dea.gov; Drug Enforcement Administration: A Tradition of Excellence, 1973–2003 (Department of Justice and Drug Enforcement Administration, 2003); Kenneth J. Meier and Laurence J. O’Toole Jr., Bureaucracy in a Democratic State: A Government Perspective (Johns Hopkins University Press, 2006); David F. Musto and Pamela Korsmeyer, The Quest for Drug Control: Politics and Federal Policy in a Period of Increasing Substance Abuse, 1963–1981 (Yale University Press, 2002); Dennis D. Riley, et al., Bureaucracy and the Policy Process: Keeping the Promises (Rowman & Littlefield, 2006); David Robbins, Heavy Traffic: Thirty Years of Headlines and Major Ops from the Case Files of the DEA (Chamberlain, 2005). Elizabeth R. Purdy, Ph.D. Independent Scholar
Dyslexia Dyslexia, also known as a reading disorder, is the most common and best studied of the learning disabilities. A reading disorder refers to children who do not begin
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Learning disabilities can persist into adulthood and it is estimated that dyslexia affects between 4 and 15 percent of the population.
to read at the appropriate time and have no obvious reason for failure to do so. Dyslexia is diagnosed when achievement on individualized, standardized tests is substantially below what is expected. It must be differentiated from normal variations in learning, mental retardation, and from environmental causes such as lack of opportunity to learn, poor teaching, or the presence of significant cultural factors. Without recognition and treatment, having a learning disability can lead to demoralization, low self-esteem, and difficulties with social adjustment. Learning disabilities can persist into adulthood and it is estimated that dyslexia affects between 4 and 15 percent of the population. Living in an industrialized country where reading is fundamental to lifetime learning and job requirements, dyslexia can be a major disability. Early identification of affected individuals has the potential to make a significant impact on society in general. Establishing whether a child has dyslexia is not a simple task as there are no universally accepted definitions for categorizing an individual as having a developmental disability. The U.S. Office of Education, provided as part of Public Law 94-142, lists guidelines for determining the existence of a specific learning disability. The American Psychiatric Association has published the Diagnostic and Statistical Manual of Mental Disorders, 4th edition (DSM-IV), which spec-
ifies criteria that must be met in order to diagnose a reading disorder. The essential diagnostic feature is that one’s reading achievement is substantially below that expected given the individual’s chronological age, measured intelligence, and age-appropriate education. In addition, the reading disturbance must significantly interfere with academic achievement or with activities of daily living. If the child has a vision or hearing impairment, neurological, or other medical condition, the reading difficulties must be in excess of what would be expected in those situations. One of the major tasks for school-aged children is learning to read. Early symptoms of reading difficulty may include inability to distinguish among common letters or to associate common sounds with syllables. For the dyslexic, oral reading is characterized by distortions, substitutions, or omissions. Both oral and silent reading is characterized by slowness and errors in comprehension. Federal legislative action, noted in Public Law 99-457, has provisions that guarantee that diagnostic and interventional services will be made available to those who display significant developmental delays or have been diagnosed with physical or mental conditions that have a high probability of causing developmental delays. Although symptoms of reading difficulty may appear as early as kindergarten, a reading disorder is seldom diagnosed before the end of kindergarten or the beginning of first grade because this is when formal reading instruction usually begins in most school settings. Unfortunately, this alone does not guarantee early recognition of the disability. When a child is very bright, he or she may be able to function at or near grade level, so that the problem is not identified until fourth grade or later. Dyslexia is a complex disorder that requires careful team evaluation to rule out other disorders that may mimic it. Deficits in visual perception, linguistic processes, attention, and/or memory may be involved. There may be underlying abnormalities in cognitive processing that precede or are associated with learning disorders. Many individuals with psychiatric disorders diagnosed in infancy and early childhood also have learning disorders. These include conduct disorder, oppositional defiant disorder, attention deficit hyperactivity disorder, and major depression. When a child is noted to be struggling academically, he or she should be referred for evaluation. Psychologists are professionals trained to administer and inter-
pret testing results. Reading ability is correlated with intelligence and diagnosed using discrepancy scores. There are standardized tests available to determine intelligence (IQ) and academic achievement. A variety of statistical approaches are then used to establish that a discrepancy is present. A significant difference between IQ and academic achievement scores is usually defined as more than two standard deviations or two years below what is expected for chronological age. In mental retardation, learning difficulties are consistent with their lower intelligence scores. Children from backgrounds where English is not the primary language or where teaching has been inadequate may score poorly on achievement tests and this must be taken into consideration before making a diagnosis. It is rare for a reading disorder to be diagnosed in isolation; mathematics disorder and disorder of written expression are commonly identified in the same individual. The majority of individuals diagnosed with a reading disorder are males. However, this is thought to be due to a bias in referral as boys tend to be more problematic in the classroom. The diagnosis is found to occur at more equal rates in males and females when careful referral and stringent diagnostic criteria are used. Clustering of dyslexia in families has been noted since the early 1900s and reading disorders are more prevalent among first-degree biological relatives of individuals with learning disorders. At this time, the causes of reading disorders are not known but appear to be multifactorial. Learning disabilities are frequently found in association with a variety of medical conditions such as lead poisoning, fetal alcohol syndrome, and Fragile X syndrome. Genetic predisposition, injury during the birthing process, and various neurological or other medical conditions may be associated. On the other hand, many individuals with no such history have a learning disability. The cause of dyslexia has been the subject of much speculation. Behavioral, social, and neurobiological factors continue to be recognized as possible important factors. Different subtypes of dyslexia, with proposed etiologies and neuropsychological rationales for treatment exist. Among the leading speculations being considered are phonological deficiencies, deficits in auditory processing, abnormal cortical asymmetry, a rapid automatic naming dysfunction, a cerebellar deficit, a deficit in temporal processing, and visual deficits.
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Remarkably, little research on the treatment of developmental dyslexia has been published during the last 25 years; however, there are many studies in progress and with advancing technology, the answer may not be far off. There are hundreds of institutes all over the world that offer programs to facilitate the reading of dyslexic children. The important question is, and remains, what is the best learning environment for a particular child hampered in the ability to read? Despite the unanswered questions, it appears that with early identification and intervention, having a reading disorder has a good prognosis in a significant percentage of cases. SEE ALSO: Child Development; Child Mental Health;
Learning Disorders; Psychologist; Psychiatry.
Bibliography. Dirk Bakker, “Treatment of Developmen-
tal Dyslexia: A Review,” Pediatric Rehabilitation (v.9, 2006); Diagnostic and Statistical Manual of Mental Disorders, 4th ed. (American Psychiatric Association, 2000); Kimberly Noble and Bruce McCandliss, “Reading Development and Impairment: Behavioral, Social, and Neurobiological Factors,” Developmental and Behavioral Pediatrics (October 2005); Steven Pliszka, Caryn Carlson, and James Swanson, ADHD with Comorbid Disorders: Clinical Assessment and Management (Guilford Press, 1999). Debra A. Willsie, D.O. University of Missouri–Kansas City
Dysmorphology Dysmorphology is the study of abnormal form in the human body. This relates to anatomy of patients who may have genetic and congenital birth defects. The pediatrician, endocrinologist, embryologist, and clinical geneticist, Dr. David Smith, first began this area of interdisciplinary study of medicine in the 1960s. At this time, clinical genetics were at their infancy. The study of dysmorphology involves observation and assessment of patients, the understanding of intricacies in the genetic disorder, and any relevant treatment measures available. When ����� a physician confronts the patient and family issues relating to morphological birth defects and their
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genetic components, that physician is taking on the role of dysmorphologist. In the developing world, a myriad of congenital birth defects remain underdiagnosed, poorly treated, and misunderstood. The social stigma, isolation, and lack of adaptation can lead to a loss of quality of life. A physician acting as dysmorphologist is able to identify these risks for defects and offer clinical support to the patient and family. The lack of access to this treatment and assessment in least developed nations throughout the world leads to patient suffering. For example, the level of care that is expected for such assessments when the index of suspicion is high for any dysmorphology include nutrition; basic lifestyle and occupation and work details; medical, obstetric, and drug histories; if possible, genetic and biochemical data collection (difficult in the developing world); and overall assessment of clinical dysmorphology with a family history. Also, assessing a person’s body proportion (the length of the arms and legs relative to the trunk) may provide information for further examination. With a prolonged birth and breech presentation, congenital dislocation of the hip, clubfeet, and a flattened, elongated “breech head” can result. These morphological abnormalities are usually benign and can be corrected. However, a simple obstructed urethra causing a deficient volume of amniotic fluid leads to flattened facial features and fixed joints. One minor malformation in the patient should not cause major concern, particularly if the feature is shared with a parent and does not affect daily life. As outlined by many clinical genetics protocols, three or more malformations, especially if associated with short stature, failure to thrive, a slower developed head and brain, or other developmental delay, should bring about further investigation in the newborn or infant. Much of these needs cannot be met in the developing world. For example, abnormalities of the spine can be major malformations that are readily apparent at birth but poorly treated in developing nations. Some specific examples that plague developing countries without access to prenatal care as in the case of Africa and Asia are anencephaly (absent skull and brain), encephalocele (cranial defect with brain coming out into external sac), and spina bifida. All of the above dysmorphological disorders result in death to the child.
SEE ALSO:� Adolescent Development; Beals, Rodney K.;
Birth Defects; Brain Malformations; Genetic Testing/ Counseling; Growth Disorders; Neural Tube Defects.
Bibliography. “Basic Dysmorphology,” http://www.
usd.edu/med/som/genetics/curriculum/2EDYSMO5. htm (cited June 2007); Muin J. Khoury, et al., “The Interaction between Dysmorphology and Epidemiology: Methodologic Issues of Lumping and Splitting,” Teratology (v.45/2, 1992). John M. Quinn V, M.P.H. University of Illinois at Chicago
Dysphagia Dysphagia is a condition of having difficulty swallowing. Two classifications exist: transfer dysphagia and esophageal dysphagia. Both are characterized by the complaints that foods and liquids are slow to go down and cling to the throat. Both can be either sporadic or chronic in nature. Additionally, both have certain triggers that help classify the disorder. Transfer dysphagia is caused by disorders often stemming from strokes or neurological complications. In this case, a disruption of the motor sensors and controls prevents a patient from being able to trigger the swallowing mechanisms in an automatic fashion. The life span of transfer dysphagia is affected by what the underlying cause is. Patients who have had a stroke often experience weakness of one side of the mouth that makes the swallowing process difficult. This weakness, however, can be mediated with time and practice. Some neurological disorders, however, have a bleaker outcome and the life of the patient may be riddled with bouts of dysphagia. Regardless of the underlying cause of transfer dysphagia, it is characterized as being triggered by the swallowing process rather than a certain type of food. Because the problem is with the swallowing action, a major concern for transfer dysphagia patients is that food or drink will enter the lungs or chest cavity, cause choking, or be expelled from the nose. Unlike transfer dysphagia, esophageal dysphagia is typically caused by structural disorders in the
Dystonia
throat. Tumors and lesions in the throat are very common to the esophageal dysphagia patient. The defining aspect between transfer dysphagia and esophageal dysphagia is that esophageal dysphagia is linked directly to food and not the act of starting to swallow. In esophageal dysphagia, the act of swallowing can be initiated with success, but the food or drink may be slow to go down the throat, or may cause a clinging sensation—a feeling that the food is clinging to the throat. Esophageal dysphagia can be long lasting or may occur only a few times without a noticeable pattern. With that, esophageal dysphagia can start out weak and progress in severity, or start out in a very severe fashion and ease with time. The major factors at work in either case are the underlying conditions that are causing the esophageal dysphagia. Structural disorders such as a tumor may be slow to grow and will not block as much food as would occur in the later stages of growth. Conversely, a heavy impact to the throat or muscles surrounding the throat may cause a sudden challenge to swallowing, one that will soften with time. Regardless of the cause, patients with esophageal dysphagia often experience comfort with regurgitation of the food. Regurgitation is typically better tolerated than trying to force the food to swallow, which may cause some additional discomfort. Complaints such as heartburn, sore throat, chest pain, and coughing up food are common to the esophageal dysphagia patient. Both transfer dysphagia and esophageal dysphagia are defined as difficulty swallowing. Transfer dysphagia is characterized by the physical act of initiating the swallow, while esophageal dysphagia is characterized by the food or drink not going down correctly. SEE ALSO: Bell’s Palsy; Cancer (General); Food Allergy. Bibliography. Elayne Achilles, The Dysphagia Cook-
book: Great Tasting and Butritious Recipes for People with Swallowing Difficulties (Cumberland House, 2003); Lynn S. Bickley, ed., Bates’ Guide to Physical Examination and History Taking, 8th ed. (Lippincott Williams and Wilkins, 2003). William J. Hamilton Arizona State University
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Dystonia Dystonia is a movement disorder consisting of involuntary muscle contractions, which force certain parts of the body into abnormal, sometimes painful, movements or postures. This can affect any part of the body including the arms, legs, trunk, neck, eyelids, face, or vocal cords. This movement is not controlled by the patient and can be painful. Dystonia can be present in patients with cerebral palsy, Parkinson’s disease, or other neurological problems. If dystonia causes any type of impairment, it is because muscle contractions interfere with normal body function. Features such as cognition, strength, and the special senses are usually normal. Dystonia is not fatal; however, it is a chronic disorder and prognosis is difficult to predict due to the different body systems involved. It is the third most common movement disorder after Parkinson’s disease and tremor that affect more than 300,000 people in North America. Dystonia does not discriminate and it effects all races and ethnic groups the same way. In the developing world, diagnosis and treatment of dystonia can be elusive and complex as symptoms vary and neurological diagnostics are often nonexistent. The German neurologist, Dr. Hermann Oppenheim, of Berlin was interested in the variation in muscle tone seen in neurologic pathologies that he encountered in several young patients. In his papers, he used the term dystonia to indicate that muscle tone was hypotonic at one occasion and tonic spasm at another. Hypotonic means having less-than-normal tension in the muscle and tonic is continuous tension or nonstop contraction of muscles. As the term dystonia has been widely accepted and has been used by neurologists and other physicians alike; other terms such as repetitive movement disorder and muscle twitch have also been used. These terms and concepts are directly related to muscle tone. This is the level of muscle contraction present during resting state. With increased tone, there is stiffness and rigidity, while with decreased tone, there is looseness of the limbs and trunk. However, the definition of dystonia has grown with the levels of diagnosis and categories expanding. The major issue most diagnosticians have with these additions to dystonia is that by using only sustained postures for their definition, this allows many types of abnormal postures to be called dystonia, such as fixed postures that could develop from a stroke. Furthermore, these
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definitions do not take into account other types of abnormal neurological movements. In the early 1980s, a committee consisting of members of the Scientific Advisory Board of the Dystonia Medical Research Foundation developed the following definition: “Dystonia is a syndrome of sustained muscle contractions, frequently causing twisting and repetitive movements, or abnormal postures.” This committee also proposed a classification schedule for dystonia. This scheme recommends three classifications: age at onset, parts of body affected, and etiology or the cause and origin of disease.
SEE ALSO:� Aphasia; Bell, Charles; Bell’s Palsy; Dysphasia;
Movement Disorders; Muscle Disorders.
Bibliography. Mitchell Brin, Cynthia Comella, and
Joseph Jankovic, Dystonia: Etiology, Clinical Features, and Treatment (Lippincott Williams & Wilkins, 2004); Dystonia Medical Research Foundation, http://www.dystoniafoundation.org. John M. Quinn V, M.P.H. University of Illinois at Chicago
E Ear Disorders Ears are the organs that help humans hear. The ears modify sound input, communicate it through the cartilaginous tissue and ear canals, and send signals through nerves, and into the brain. In addition, ears participate in body systems assisting with balance. Ear disorders have a variety of causes. The ear, or auricle, has three separate areas: the external ear, the middle ear, and the inner ear. An otoscope is the tool medical practioners use to examine the ear. Often a pneumatic bulb is used as well. The outer part of the ear is made of cartilage. This part of the ear collects sound through the air. The sound is then transmitted into the external canal, through the middle ear, and to the inner ear where hair cells send signals through the nerves to the brain. The layers of the skin around the ear and the canal have thin hairs and, cerumen, or ear wax, is produced. Sometimes cerumen can completely occlude the external ear canal and dampen sound. External ears have been decorated for thousands of years. In some cultures, earlobes have stretched and enlarged to signify importance within the community. Other cultures have traditionally pierced earlobes for decorative jewelry. Occasionally, superficial infections of the skin on the ear can occur, sometimes due to
these piercings or insect bites. Repeated injury to the cartilage sometimes does not allow the ear to heal correctly to its original shape; the normally soft and malleable cartilage becomes hard and lumpy. Thus, frequent trauma can distort the entire cartilage sometimes seen in “wrestler’s ear” or “cauliflower ear.” Foreign bodies may become lodged in this location of the ear, as well. Additionally, the external canal of the ear can become infected, a condition known as “otitis externa” or “swimmer’s ear.” This uncomfortable ailment is commonly treated with topical medications. Although rare, congenital external ear malformation can occur during embryologic development. Also, bony growths, called osteomas, may be in the external canal and uncommonly cysts and tumors will grow there. Anatomically, the external ear ends at the tympanic membrane, or eardrum. The middle ear compartment begins behind the tympanic membrane. Sound is conducted through air in this compartment. The Eustachian tube connects the middle ear compartment to the posterior area of the pharynx. This tube helps to equalize pressure from the surrounding atmosphere to the middle ear cavity. Although the tube is normally closed, it opens up with swallowing and positive pressure. Increasing altitude in an airplane causes the air to expand and open the tube. However, upon descent, the volume of air shrinks
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and causes a vacuum in this closed system. Divers also experience this “Eustachian tube dysfunction” but for a different reason. In those cases, as divers go deeper, the external atmospheric pressure under water increases. This also causes a vacuum to occur. When the Eustachian tube is not working correctly, people will complain of a pressure sensation, or a popping and clicking sound in their ear. Active opening of the tube (by applying pressure to the nasal cavity) is sometimes necessary to open the Eustachian tube. An otoscope with the attached pneumatic bulb can help assess the movement of the tympanic membrane and assist with the examination of the middle ear and diagnosis. Sometimes, fluid can accumulate behind the ear drum. Clear, noninfected fluid is known as “serous otitis.” This may accumulate when the Eustachian tube is not functioning correctly, occasionally because of viral illnesses or seasonal allergies. When the fluid behind the ear drum becomes thicker appearing or discolored, it may be infected. The ear drum compensates for this fluid accumulation by bulging and reddening, and is called “otitis media.” These painful occurrences may be either viral or bacterial, and antibiotics are not always required. Occasionally, a tympanic membrane ruptures. A spontaneous rupture may occur secondary to fluid accumulation and infection, behind the ear drum. Purulent drainage and blood then may become evident, as the discharge comes out of the middle ear and through the external ear canal and to the outside of the ear. Tympanostomy tubes are sometimes placed surgically, through the ear drums, to assist in the treatment of chronic ear infections. When the tube is functioning correctly, any fluid accumulating behind the ear drum will drain out. Traumatic tympanic membrane ruptures may also happen from exposure to sudden loud sounds, severe pressure changes related to Eustachian tube dysfunction, or puncture wounds from foreign bodies placed in ears. A ruptured tympanic membrane is typically painful and impairs hearing until healing is complete. Scars become evident on the tympanic membrane from ruptures, and repeated scarring may chronically impair ability to hear. Rarely, a cholesteatoma may grow within the middle ear. This benign mass is typically skin tissue that may be locally destructive and have chronic drainage, causing hearing loss and nerve damage. The inner ear is the third part of the ear. This area of the ear helps with hearing and balance through a se-
ries of bones, semicircular canals, hollow areas, fluid filled areas, different types of hair cells, and a cranial nerve sending signals to the brain. A common symptom might include dizziness due to a malfunction of the balance centers. Because physicians are unable to directly visualize the inner ear, it is more difficult to definitively diagnose these problems. Hearing loss is a common disorder of ears. Hearing impairment is further categorized as conductive hearing loss (often pathology of the external ear, the middle ear, or both), sensorineural hearing loss (related to a problem with the inner ear or the nerves leading to the brain), or a mixed hearing loss which is both conductive and sensorineural. The loss may be sudden or chronic. A 512-Hz tuning fork may help with delineate the type of hearing loss. Softly striking the tuning fork and placing it midline on the patient’s forehead is called the Weber’s test. In patients with normal hearing, the sound remains midline. However, a conductive hearing loss causes the sound to be heard best in the affected ear and a sensorineural hearing loss causes the sound to be heard best in the normal ear. A Rinne test helps to assess air conduction and bone conduction. The 512-Hz tuning fork is softly struck. Patients should be able to hear the sound as it is placed on the mastoid bone. This assesses bone conduction. Once the sound is no longer appreciated by the patient, the tuning fork is then placed next to the ear canal to assess air conduction. The sound is appreciated through the air in patients with normal hearing or sensorineural hearing loss meaning air conduction is better than bone conduction. However, the sound is not heard in conductive hearing loss, implying bone conduction is better than air conduction. Formal audiometry testing is indicated in patients with hearing loss. Furthermore, speech development is dependent upon ability to hear; many hospital nurseries now screen newborn children for congenital hearing loss with specialized mechanical equipment, just after delivery. See also: Deafness; Dizziness and Vertigo; Ear Infec-
tions; Infant and Toddler Development; Infant and Toddler Health; Piercings and Tattoos.
Bibliography. Clinical Practice Guideline–Diagnosis
and Management of Acute Otitis Media (American Acad-
Ear Infections
emy of Pediatrics and American Academy of Family Physicians, 2004); Jon E. Isaacson, and Neil M. Vora, “Differential Diagnosis and Treatment of Hearing Loss,” American Family Physician, (v.68/6, 2003); Robert Sander, “Otitis Externa: A Practical Guide to Treatment and Prevention,” American Family Physician (v.63/5, 2001). Ann M. Karty, M.d., Faafp Kansas City University of Medicine and Biosciences
Ear Infections Ear infections, specifically infections of the middle ear, are common childhood infections in industrialized countries and the leading cause of outpatient antimicrobial treatment of children in the United States. Infections of the middle and inner ear can cause temporary or permanent loss of hearing and associated speech and language delays. The World Health Organization estimates that in developing countries, 51,000 children under 5 years of age die annually from complications of infections of the middle ear. There are three types of ear infections characterized by location in the ear. Infection of the middle ear is known as otitis media and is characterized by infected fluid behind the eardrum. Otitis is the Latin word for inflammation of the ear. The eardrum separates the inner ear from the ear canal. Infections of the middle ear are defined by acute otitis media, a middle ear infection with both effusion, or fluid, and presence of signs or symptoms of an acute infection, or by otitis media with effusion, a middle ear infection with effusion and without signs or symptoms of an acute infection. Signs and symptoms of acute otitis media include pulling of the ear in an infant, irritability in an infant or toddler, discharge from the external ear, and fever. By 3 years of age, 50 to 85 percent of children in the United States have had acute otitis media with peak incidence between ages 6 and 11 months. Recurrent acute otitis media infections, defined as three or more episodes of infection, affect 10 to 20 percent of children by 1 year of age. Children with recurrent acute otitis media infections may have a surgical treatment, myringotomy, whereby a small tube is placed inside the affected ear by an otolaryngologist. Infections of the middle ear are caused
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by Eustachian-tube dysfunction, bacterial infection, viral infection, or immune response to infection. Common bacterial infections include Streptococcus pneumoniea, Moraxella catarrhalis, and nontypeable Haemophilus influenzae. Risk factors for infections of the middle ear include young age (less than 2 years old), daycare attendance, having older siblings, fall and winter season, impaired immune system, genetic predisposition, and family history. Acute otitis media spontaneously resolves, without treatment, within 2 to 14 days in 80 percent of children between 2 and 12 years of age. Antibiotic treatment is recommended for children without improvement in symptoms following 48 to 72 hours of observation. Infection of the outer ear is known as otitis externa and is characterized by infected fluid in the ear canal. Infection of the outer ear is also known as swimmer’s ear. Infections of the outer ear are defined by acute or chronic forms. Acute otitis externa is generally diagnosed by signs and symptoms of a bacterial infection, such as an odorless secretion from the ear, itching, and pain. Chronic otitis externa is commonly due to a fungal infection or allergic reaction, generally due to an inflammation of the skin of the ear canal. Acute otitis externa affects 4 in 1,000 people annually in the United States, is most common in children 7–12 years of age, and is associated with high humidity, warmer temperatures, swimming, local trauma in the ear, and hearing aids. Chronic otitis externa affects 3 to 5 percent of the population in the United States. Treatments for infections of the outer ear include topical therapy and
Ear infections are the leading cause of outpatient antimicrobial treatment of children in the United States.
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amelioration of inciting factors. Twenty-five percent of individuals treated for otitis externa will also be given an antibiotic. Infection of the inner ear is known as otitis interna or labyrinthitis. Inner ear infections can be caused by bacterial infections such as meningitis or syphilis (either congenital or acquired). Viral infections also cause infections of the inner ear through congenital infection, as part of a systemic viral illness, or an isolated involvement of the inner ear. Confirmed associations have been identified between infections of the inner ear and cytomegalovirus (congenital infections) and mumps (acquired). Cytomegalovirus is considered the most common congenital infection in the United States and the most common infectious cause of congenital deafness. Suspected pathogens associated with infection of the inner ear include rubella (congenital), rubeola, influenza, varicella-zoster, EBV, poliovirus, RSV, adenovirus, parainfluenza, and herpes simplex viruses. Congenital infection with the protozoa, toxoplasmosis, also leads to inner ear infections. Fungal infections of the inner ear are rare unless an individual is immunocompromised. Symptoms of infections of the inner ear include dizziness, vertigo, ringing in the ears, and hearing loss. Idiopathic sudden sensorineural hearing loss in an otherwise health individual is usually due to a viral inner ear infection. Approximately 30 to 70 percent of patients will have partial or complete recovery of hearing with proper treatment. SEE ALSO: Bacterial Infections; Deafness; Hearing Prob-
lems in Children; Otolaryngologist; Viral Infections.
Bibliography. J. David Osguthorpe and David R. Nielsen,
“Otitis Externa: Review and Clinical Update,” American Family Physician (v.74/9, 2006); Maroeska M. Rovers, et al., “Otitis Media,” Lancet (v.363, 2004). Rebecca Malouin, Ph.D., M.P.H. Michigan State University
East Timor Located in southeast Asia, East Timor was a Portuguese colony from 1702, and in 1951 became an overseas province of Portugal. In August 1975, there was a
civil war, and soon afterward, Indonesia invaded East Timor, occupying it until 1999 when it was controlled by the United Nations. In May 2002, it finally gained independence. During most of the period of Portuguese rule, the healthcare services were underdeveloped. Many of the health problems in East Timor were because of malaria and other insect-borne diseases, as well as poor hygiene. To improve these, J. Gomes da Silva was appointed to take over the running of medical services in East Timor, and found that the hospital was badly equipped, and all the Christian cemeteries were badly positioned, causing possible contamination of the water supply for Dili and other towns, and being a probable source of cholera. No action was taken on the report he made on the problems he found. In December 1940, José dos Santos Carvalho was appointed as the health delegate for the central and eastern parts of East Timor, remaining there during the Japanese Occupation, and writing the major work on the history of medicine in East Timor. In 1948, there were four hospitals and six doctors in East Timor. The health problems at the time included malaria, pneumonia, elephantiasis, tuberculosis, cholera, and venereal diseases. Four years later, in 1952, the First National Congress of Tropical Medicine was held in the Portuguese capital, Lisbon. Annual congresses were held for the next few years where Portuguese colonial administrators coordinated their medical care programs, which at that stage were mainly for the Portuguese and other Europeans. By 1958, the congresses had become renamed the International Congress for Tropical Medicine and Malaria, and over the next few years the World Health Organization led campaigns to eradicate malaria which did affect many people in East Timor. When Indonesia invaded East Timor in 1975, there was only one major hospital, located in Dili, the administrative capital of East Timor. Even though the vast majority of the population of East Timor opposed the Indonesian Occupation, many did accept that the Indonesians did massively improve healthcare in what became their 27th province. Indeed, prior to the Indonesian invasion, there was only one surgeon and one dentist covering the entire population of 610,000, although there were often a dozen doctors serving in the Portuguese army. From 1976 until 1999, the provision of healthcare in East Timor was much better
Eating Disorders
than many other parts of Indonesia, with the Indonesian government eager to win over the population of the place. More hospitals were built, and clinics opened in many small towns. However, in 1999, in a referendum, the people voted heavily in favor of independence. After this, pro-Indonesian militia destroyed much of the government infrastructure in the place. This destruction saw the burning down of clinics and medical centers around the country. Since 1999, there have been attempts to rebuild the East Timorese health services, and the presence of large numbers of United Nations and foreign soldiers and officials in the country, several hospitals were refurbished. Malaria still remains a major problem in the country, with problems over dengue fever, tuberculosis, and cholera. SEE ALSO:
Cholera; Dengue; Indonesia; Malaria.
Bibliography. Geoffrey C. Gunn, Timor Loro Sae: 500
Years (Livros do Oriente, 1999); José dos Santos Carvalho, Vida e morte em Timor durante a segunda Guerra mundial (Livraria Portugal, 1972).
Justin Corfield Geelong Grammar School, Australia
Eating Disorders Eating disorders are among the most lethal of the psychiatric diagnoses and generally occur in adolescent girls or young women. However, eating disorders do not exclusively affect females; men experience these illnesses at surprisingly high rates as well. An estimated five million Americans each year are affected by these multidimensional illnesses which can cause devastation to the individual’s work, home, and personal life. While these illnesses are generally characterized by a serious eating disturbance accompanied by excessive concern about body weight and shape, each disorder has distinct clinical features. Anorexia nervosa (AN) is described as a refusal to maintain normal body weight for one’s age and height, an intense fear of becoming fat, and a loss or disruption of menstrual periods, while bulimia nervosa (BN) is characterized by episodic binge eating followed by an
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engagement in compensatory behaviors such as vomiting or laxative misuse. The third and largest category is eating disorder not otherwise specified (EDNOS) which includes binge-eating disorder. Diagnostic Criteria The Diagnostic and Statistical Manual of Mental Disorders, 4th edition (DSM-IV), published by the American Psychiatric Association, establishes criteria used in diagnosing and distinguishing eating disorders. AN is diagnosed according to four diagnostic criteria: a refusal to maintain body weight within a normal range for the person’s age and height; an intense fear of gaining weight; a severe disturbance of body image in which body image becomes responsible for self-worth accompanied by a denial of the gravity of the illness; and in women past the age of menarche, an absence of more than three menstrual cycles (amenorrhea). Additionally, there are two currently recognized subtypes of AN: restricting (ANR) and bingeing/purging (ANBP). Individuals with ANR use constraint in their eating to reduce their weight and are, in general, more perfectionistic and restrictive in their eating behaviors. In contrast, individuals with ANBP may binge and use purging methods (i.e., vomiting, laxatives) to control their weight; the ANBP subtype is typically more categorically impulsive, older, and may be more likely to be suicidal or to have substance abuse problems. The DSM-IV criteria for BN include recurrent episodes of binge eating accompanied by a feeling of a loss of control (binge eating constitutes a consumption of larger-than-normal quantities of food in a discrete period); recurrent compensatory measures to avoid gaining weight post-binge that either involve purging (e.g., self-induced vomiting) or nonpurging activities (e.g., excessive exercise or fasting); the bingeing and purging behaviors occur a minimum of two times a week for a duration of three months; selfevaluation is disproportionately influenced by body shape and weight. In addition, these disturbances do not occur during episodes of AN. Also included in the DSM-IV is the category eating disorder not otherwise specified, which includes all clinically significant eating behaviors that do not fit neatly into the categories of AN or BN. Although it is referred only as a research diagnosis, binge-eating disorder falls into this category and is receiving much
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attention in the current contexts of the obesity epidemic as well as in the pending revisions to the DSMIV. Binge-eating disorder’s hallmark characteristic is binge eating (i.e., consuming in a discrete period a larger-than-normal amount of food for that particular time) at least two days a week for a duration of six months. These binges are similar to those that occur with BN, but in addition, meet at least three of the five following criteria: eating more rapidly than normal; eating until uncomfortably full; eating large amounts of food when not otherwise feeling physically hungry; eating alone out of embarrassment; or feeling disgusted with oneself or guilty after overeating. Epidemiology, Cause, and Features Epidemiological trends in eating disorders are difficult to characterize due to the complex nature of the illness and the manner in which they are conservatively self-reported. However, the majority of research studies indicate a growing trend in the emergence of anorexia and bulimia during the last half-century. Although eating disorders usually occur in adolescent girls or young women, a significant number of new cases are seen in boys and men. The first nationally representative study of eating disorders in U.S. households found that the overall lifetime prevalence of eating disorders in 0.6 to 4.5 percent. This same population-based interview estimated the lifetime prevalence of AN to be 0.9 percent in women and 0.3 percent in men. BN also primarily affects women and tends to develop during late adolescence and early adulthood. Thus, prevalence rates for younger adolescents are generally lower than those reported by college students. Current lifetime prevalence rate for BN is 1.5 percent in women and 0.5 percent in men. Although the range of disordered eating is broad outside a diagnosis of AN or BN, relatively little is known about EDNOS itself. Individuals who receive a diagnosis of EDNOS are often excluded from other treatment studies. It is estimated, however, that between 3 to 5 percent of women aged 15–30 in Western countries suffer from EDNOS. Its most studied disorder, binge-eating disorder, occurs more frequently in females, yet is also more evenly distributed across age, gender, and ethnicity than other eating disorders. The lifetime prevalence of binge-eating disorder is 3.5 percent in women and 2.0 percent in men.
Eating disorders are are among the most lethal of the psychiatric diagnoses and affect an estimated five million Americans a year.
To date, the precise causes of eating disorders remain to be identified although neurochemical, genetic, developmental, psychological, family, and sociocultural factors have been implicated in various combinations. For example, societal ideals of thinness and harmful media images have received much attention for contributing to the development of body image disturbance. A causal relationship has been established between women who experience body dissatisfaction and media images, which in turn, can create a risk for development of disordered eating behaviors. A history of dieting in response to societal factors has also emerged as a predictor of eating disorders and disordered eating attitudes. Additionally, young women who engage in sports or artistic endeavors that emphasize thinness (such as ballet, modeling, or running) are observed to have a higher incidence of eating disorders. The role of families in the social influence of eating disorders has been explored for causal factors of the illness. In a psychoanalytic model of family influence, eating disorders were interpreted as a fear of sexual maturity in young women, although these fears may not be exclusively associated with eating disorders. The psychodynamic model of family influences attributes eating disorders to an unresolved mismatch between parental and child needs, while a family
systems model studies parental criticism and dysfunction. Another perspective further examines the observation that eating disorders run in families by asserting that disordered eating attitudes and weight concerns are, in fact, behaviors learned by children from their parents. Cognition, behavior, and personality also contribute to the development of eating disorders. For example, AN has been associated with high levels of constraint and perfectionism, while BN is linked with impulsive behavior and poor emotional regulation. Negative emotionality is common to both disorders. The etiology of eating disorders is multifactorial; traumatic experiences, including sexual violence, have been implicated as a risk factor in a number of studies. The results, however, are conflicting and reveal a complex yet nonspecific relationship between eating disorders and sexual assault. Several studies have found that a history of sexual trauma is more often reported by women with BN than by women with AN and that trauma-induced dissociation influences bulimic symptomatology. There is incontestable evidence that biology contributes to the etiology of eating disorders. The role of neurochemical interactions that govern satiety is another area ripe for research. Neurotransmitters such as norepinephrine and serotonin may account, at least partially, for the cardiac and neuropsychiatric changes seen in individuals with AN. Also, genetics studies have concluded that women with first-degree relatives with eating disorders are at significantly higher risk for developing an eating disorder themselves. Current research on twins also shows increased heritability for eating disorders. Individuals with AN typically display the following features upon examination in a clinical setting: a recent history of weight loss, dizziness, absence of menstrual periods (amenorrhea), low blood pressure (hypotension), feeling cold all the time (hypothermia), and slow heart rate (bradycardia). Other clinical findings characteristic of AN are constipation and feeling bloated after meals, fatigue, nausea, dry skin, development of fine hairs across the body (lanugo), yellowish or orange discoloration of the skin (hypercarotenemia), and bluish discoloration of the hands or feet (acrocyanosis). Additionally, she may demonstrate a distorted body image by claiming that she is overweight or deny that her extreme weight loss
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is problematic. She may also engage in an excessive amount of exercise to control her weight. Unlike individuals with AN, women with BN may not have a history of weight loss, as many who suffer from this disorder are able to maintain a normal weight in spite of the characteristic binge and purge behavior. She may admit to feeling “out of control” around food and attempting to control her weight by engaging in compensatory behavior (typically self-induced vomiting or laxative use) after a binge episode. Her relationship to food may have an addictive quality; she may also have a history of substance abuse or may be currently abusing other substances such as alcohol or cigarettes. A physical examination may reveal some swelling of the salivary glands and abrasions or calluses near the knuckles termed Russell’s sign (caused by scraping against teeth during episodes of self-induced vomiting). She may also exhibit dental problems attributed to the erosion of enamel by stomach acid. Like women with AN, women who suffer from BN may experience interruptions in their menstrual cycle. Screening for Eating Disorders There are several screening tools of varying length that have been developed to detect eating disorders in individuals. The Eating Attitudes Test (EAT) is perhaps the most commonly used evaluative tool and has an accuracy rate of approximately 90 percent in diagnosing eating disorders according to DSM-IV criteria. Two shorter tools, the SCOFF questionnaire and the ESP, are also recognized for their efficacy in identifying individuals who might be at risk for an eating disorder although neither tool has been validated. Eating Disorders, Ethnicity, Gender Eating disorders were once thought to be an illness ascribed only to affluent, white women, but they are now an undiscriminating phenomenon; eating disorders are increasingly observed in various socioeconomic and ethnic minority groups. Although research currently is too limited to address variations in subgroups within the four main ethnic minority categories in the United States, there are both risk and protective factors inherent in each group’s cultural values. According to research, African-American women appear to be less likely to suffer from eating disorders than white women and, at a given weight, to be
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more satisfied with that weight. In contrast, rates of eating disorders in Hispanic women are very similar to those in white women although with more severe bingeing and greater body dissatisfaction in the former group. Although Asian women were found to be less likely to score high on eating disorders screening tools, there have been other studies that suggest Asian women did not differ from white women in levels of body dissatisfaction. Studies on eating disorders in Native-American samples suggest an increased level of purging among girls in this group. Additionally, there are differences in clinical presentation of eating disorders among these ethnic minority groups. For example, in some Asian cultures, weight gain does not carry the stigma that it does in the United States, and women with anorectic symptoms instead may attribute their food refusal to a physical ailment (e.g., somatization). The rate of men seeking treatment for eating disorders has increased in recent decades. Some studies have shown higher rates of eating disorders in men who participate in certain sports where weight is important (e.g., wrestling) and also in homosexual men compared to the general population; however, data concerning the latter are conflicting. On the whole, eating disorders in men closely resemble eating disorders in women, and more work is needed to understand why. Outcome The list of medical complications arising from these eating disorders is extensive. The American Academy of Pediatrics has issued a policy statement on the medical dangers of both bulimic and anorexic behaviors. Purging can result in severe electrolyte imbalances in the bloodstream, damage to the esophageal lining, poor dentition, enlarged salivary glands (which is erroneously interpreted by bulimic patients as having a “fat face”), calluses on the hands, and cardiac abnormalities. Severe caloric restriction as seen in AN can also lead to electrocardiographic and gastrointestinal abnormalities (e.g., mitral valve prolapse), anemia, amenorrhea, bone loss (osteopenia), seizures, amenorrhea, and difficulty in psychological functioning. Osteopenia is one of the most severe consequences of self-starvation and is often the most difficult to reverse. This bone loss can occur over even a short period and may lead to an increased risk for fracture of the hip and/or spine later in life. Eating disorders can be
fatal; the mortality rate for women with AN is 12 times greater than for women in the general population. Studies indicate that about half of all patients with AN have “good” outcomes as measured by weight gain and return of menstrual cycles. A number of patients “cross over” into bulimia during their recovery phase, and overall, 32 to 70 percent of those with AN achieve full recovery at a 20-year follow-up. Symptoms of BN appear to decrease over time as well, although about 30 percent of women who met the criteria for bulimia continued to engage in bingeing and purging behaviors for 10 years during follow-up. Strong fears of maturing and a low self-esteem emerged as predictors of outcome in AN and BN, respectively. Treatment and Prevention Treatment of eating disorders is costly and can range from $10,000 to $20,000 per patient per year and varies by the type of eating disorder. Because they require medical as well as psychological treatment, women with AN spend more time and resources in an inpatient setting than women with BN. Moreover, most women with BN never seek treatment for their disorder. Symptom severity, psychosocial impairment, and psychological comorbidity are all predictors of increased treatment use. Treatment for AN typically includes nutritional care, medical monitoring, and psychological treatment that may include cognitive behavioral therapy (relating thoughts and feelings to behavior) or family therapy. Effective treatment for those with BN may include cognitive behavioral therapy, other interpersonal therapy, antidepressant medication, and some combination of the three. For individuals with binge-eating disorder, dietary approaches in combination with psychotherapy and antidepressants have all been used with some success. Ideally, care for an individual with an eating disorder would employ a multidisciplinary team approach consisting of a medical provider, a dietitian, a mental health provider, and some form of nutritional therapy. However, for individuals with severe medical and/or psychological symptoms of their eating disorder, hospitalization may be required. There are a range of treatment options for those seeking specialized care for their eating disorder. These options include inpatient treatment, residential treatment programs, and outpatient treatment. Inpatient treatment programs generally include
Ecogenetics
medical monitoring, monitored meals, and group therapy sessions. Residential treatment programs, such as the renowned Renfrew Center, are similar to inpatient treatment programs and provide specialized, around-the-clock care exclusively for eating disorders. Outpatient programs are generally less expensive than inpatient or residential care and offer a high degree of flexibility in therapeutic intervention as well as offer controlled environment for mealtimes, depending on the type of program chosen, that is, day or evening. Eating disorder patients may encounter various forms of psychotherapy during their treatment, but cognitive behavioral therapy remains the most effective for individuals with BN. Cognitive behavioral therapy aids the patient in linking thoughts and feelings to disordered eating, as well as in managing anxiety and developing coping strategies. Pharmacotherapy for AN is limited, while use of antidepressants in treating BN is far more successful, particularly with the antidepressant fluoxetine (typically marketed as Prozac®). Similar success with antidepressants has been demonstrated in those with binge-eating disorder. Efforts at prevention of eating disorders have demonstrated limited success in changing disordered eating behavior; however, improvements in both knowledge and attitudes are noted. The challenge remains to increase understanding of the risk factors that lead to eating disorders as well as to sustain the success shown immediately after the intervention. SEE ALSO: Anorexia; Bulimia; Obesity; Psychiatry; Psy-
chotherapy.
Bibliography. Anne E. Becker, et al., “Eating Disorders,”
New England Journal of Medicine (v.341, 1999); Sara F. Forman, “Eating Disorders: Epidemiology, Pathogenesis, and Clinical Features,” in B. D. Rose, ed., UpToDate ( , 2007); Sara F. Forman, “Eating Disorders: Treatment and Outcome,” in B. D. Rose, ed., UpToDate ( , 2007); James I. Hudson, et al., “The Prevalence and Correlates of Eating Disorders in the National Comorbidity Survey Replication,” Biological Psychiatry (v.61/3, 2007); Pamela Keel, Eating Disorders (Pearson Education, 2005).
Lareina Nadine La Flair, M.P.H. Harvard University
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Ecogenetics Related to environmental sciences (particularly environmental health or biomedicine) and to molecular biology and genetics, ecogenetics is an emergent discipline in the interphase of these sciences. Ecogenetics initially attempted to study and understand how the genetic and environmental factors could together influence the organism’s response to carcinogenic agents and other imposed stresses. However, ecogenetics represents a growing science with many practical purposes, particularly in the field of prevention of environmentally related genetic diseases. Today, we could consider that understanding the play between heredity and environment and relating it to disease causation is the task of ecogenetics. The field of ecogenetics has emerged from the older area of pharmacogenetics and investigates how genetic polymorphisms may represent risk factors for a number of diseases associated with exposure to toxic chemicals and other environmental substances and factors. In addition, the extrapolation that genetic variations would be expected to affect responses to any kind of environmental and xenobiotic agent, not just drugs, lead to “ecogenetics,” by analyzing the critical genetic determinants that dictate susceptibility to environmentally influenced adverse health effects. Currently, it is postulated that many diseases are the result of environmental factors acting on genetically susceptible individuals. Many genetic conditions, including those involving hematological and liver diseases, serum proteins alterations, skin disorders, DNA repair diseases, and others have now been included in the study of diseases that are subject of ecogenetics. This discipline is growing faster in the area of cancer ecogenetics, particularly with the objective of preventing or avoiding neoplastic diseases. This would be reached through the use of genetic markers. Although ecogenetics seeks to examine genetically mediated differences in susceptibility to environmental agents, researchers often examine the relationship between genetic markers and disease without regard to environmental determinants. By using epidemiologic definitions of genotype–environment interaction, it can be shown that the relative risk of disease for the genetic marker is a function of the frequency of exposure to
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the environmental agent, the strength of interaction between the genotype and the agent, and the specificity of the environmental effect vis-à-vis the genotype. Currently, applications of ecogenetics to various types of diseases and some of its associated factors can be found in the biomedical literature, as the ecogenetics of some parasitic pathogens and its vectors (e.g., leishmaniasis, Chagas’s disease, etc.). Today, the field of the ecogenetics is, by far, more complex than some years ago, given the vast number of ethical, legal, and social issues related to the discipline. This is particularly important with studies investigating and evaluating genetic polymorphisms in human populations and should consider the impact of this emergent science on risk assessment, regulatory policies, and medicine and public health. SEE ALSO: Environmental Medicine; Epigenetics; Genet-
ics; Genetic Disorders; Genomics.
Bibliography. Lucio G. Costa and David L. Eaton,
Gene-Environment Interactions: Fundamentals of Ecogenetics (Wiley, 2006); Muin J. Khoury, “An Epidemiologic Approach to Ecogenetics,” American Journal of Human Genetics (v.42/1, 1988); François Noireau, “Ecogenetics of Triatoma sordida and Triatoma guasayana (Hemiptera: Reduviidae) in the Bolivian Chaco,” Memórias do Instituto Oswaldo Cruz (v.94/4, 1999). Alfonso J. Rodriguez-Morales, M.D., M.Sc. Universidad de Los Andes, Venezuela Carlos Franco-Paredes, M.D., M.P.H. Emory University
E. Coli Infections Escherichia coli are bacteria of which the virulent strains can cause significant gastrointestinal morbidity and mortality. E. coli O157:H7 is the strain most well known to the general public for causing epidemics after ingestion of contaminated water and foods, including undercooked hamburgers, lettuce, and spinach. The Centers for Disease Control and Prevention estimates that over 73,000 cases of infection and 61 deaths occur in the United States annually because of E. coli O157:H7.
First isolated in 1982, E. coli O157:H7’s virulence stems from its ability to produce several toxins. These toxins have the ability to invade the gastrointestinal mucosal surfaces, causing a range of symptoms including asymptomatic infections, severe abdominal cramps with or without fever, watery diarrhea, or grossly bloody diarrhea. More severe diseases may also occur. Hemolytic uremic syndrome causes a blood disorder, acute renal failure, and neurological symptoms, while thrombocytopenic purpura can cause low platelets. Among reported U.S. outbreaks, 23 percent of patients were hospitalized, 6 percent had hemolytic uremic syndrome or thrombocytopenic purpura, and approximately 1percent died from E. coli infections. E. coli is ubiquitous around the world. The incidence and prevalence of E. coli infections remain underreported because many infected persons do not report to their physician when they are infected, the physician does not send the correct laboratory test for definitive diagnosis, or the physician does not report the infection to the proper authorities. Seasonally, E. coli infections occur more frequently in the summer, which may be due to the higher consumption of ground meats during outdoor barbeques. Transmission of E. coli to humans occurs primarily through the contamination of the food and water supply. E. coli O157:H7 can be found in the intestines of cattle, deer, goats, and sheep. The meat may be contaminated through slaughter or through the process of grinding the meat. Additionally, E. coli can infect raw milk if the bacteria have colonized cows’ udders. E. coli is also found in sprouts, salami, and unpasteurized milk and juice. Swimming or drinking sewagecontaminated water can also be a means of transmission. Handling infected stools or inadequate hand washing can also transmit E. coli rapidly, especially among toddlers and young children. Once E. coli infection is suspected, the diagnosis can be confirmed by growing colonies of the bacteria and then assaying the colonies for the O157 antigen, the protein that causes the infection. Although it is recommended that all physicians screen for E. coli, only onequarter of laboratories actually screen all stool specimens. Because the antigen declines steeply after six days of illness, it is imperative to culture stools early. Currently, rapid detection tests are being developed. No specific treatment exists for E. coli infection. Most infected people recover from this self-limiting
Ectoparasites
illness within five to 10 days. Studies have not found antibiotics to be effective, and in some cases, antibiotics have worsened the illness. Antimotility agents (i.e. Immodium) should not be used in infected patients. One study found that patients who used antimotility agents were at increased risk to develop hemolytic uremic syndrome. In terms of prevention, a safe food supply and better hygiene practices can help curb the incidence of E. coli infections. Physicians should counsel patients on proper handling of meat, including correct cooking temperatures, hand washing, using only treated water for cooking and drinking, and drinking only pasteurized liquids. See also: Bacterial Infections; Centers for Disease Con-
trol and Prevention (CDC); Digestive Diseases (General), Drinking Water; Food and Drug Administration (FDA); Food Contamination/Poisoning; Food Safety. Bibliography. T.G Boyce, D.L. Swerdlow, and P.M. Grif-
fin, “Escherichia coli O157:H7 and the Hemolytic-Uremic Syndrome,” New England Journal of Medicine(v.333/6, 1995); Centers for Disease Control and Prevention, “Escherichia coli O157:H7”, www.cdc.gov (cited October 2006); C. Su, and LJ Brandt “Escherichia coli O157:H7 Infection in Humans.” Annals of Internal Medicine (v.123/9, 1995). Lindsay Kim, MPH Emory University School of Medicine
Ectoparasites Parasites are organisms that feed, grow, or find shelter in or on a host organism without contributing to the survival of the host. Ectoparasites are parasites, usually insects, that reside on the exterior of the host organism, as opposed to endoparasites, which live inside organs, tissues, or cells. Human ectoparasites live on or in the skin and usually feed on blood or keratin from their human host. Most ectoparasites go through at least part of their life cycle on their host organism and are members of the insecta class of invertebrates—lice, fleas, and flies—or the arachnida class—ticks, scabies, and others. Ectoparasites are very common and were responsible for transmitting the infectious agents that caused
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some of the worst plagues in human history. Today, they continue to cause significant morbidity and even mortality in many parts of the world. The human diseases caused by ectoparasites are due either to the infestation itself, or a virus, bacteria, or parasite carried by the ectoparasite vector. Many ectoparasites are simply a nuisance, such as lice of the head, body, or pubic area. Lice cause itching, irritation, and occasionally secondary bacterial infections, but rarely any more serious disease. Other ectoparasites such as scabies and the tungiasis (tunga penetrans) flea cause disease when the female lays her eggs in the skin of human hosts. This causes intense itching and discomfort and can also lead to secondary infections. Similarly, certain tropical species of flies can intentionally or accidentally deposit their eggs under human skin. These eggs develop into larva which cause pain and irritation and eventually exit the skin, much to the surprise of the unsuspecting host. Scabies and lice are the most common ectoparasites encountered in North America and are a common cause for presentation to primary care providers. Many other types of chiggers, mites, and blister beetles inhabit environments from mattresses to jungles, and have effects from allergic irritation to blistering and infection. Certain types of ticks can cause paralysis in children by injecting a potent neurotoxin into the blood as it feeds. Over several days, the effects of tick paralysis may present as a feeling of unsteadiness and progress to weakness in the limbs and possible respiratory failure. This type of tick paralysis is rare, but residents and visitors to tick-infested areas should be aware of the risks, and inspect their bodies for ticks after outdoor activities. The most important route by which ectoparasites cause disease in humans is by acting as vectors for dangerous bacteria. For example, Lyme disease is caused by a bacteria transmitted in North America by the Ixodes ticks found primarily in New England states. Lyme disease presents initially as a bulls-eye rash, and if not treated, it may lead to nervous disorders, heart problems, or joint swelling and pain. Over 15,000 cases of Lyme disease are reported in the United States each year; while treatment is available and effective, many cases go unnoticed. Another very important family of diseases transmitted by ticks are rickettsia (also known as Ehrli-
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chia). These are very small bacteria that are responsible for a variety of diseases including the typhus group (murine typhus, epidemic typhus, and scrub typhus), the spotted fever group (Rocky Mountain spotted fever, rickettsial pox, and others), as well as Q fever and trench fever. Each of these diseases is carried by a different type of ectoparasite tick, louse, or mite, which is, in turn, normally carried by a mammal such as a mouse, dog, squirrel, or human. The diseases caused by rickettsia range from mild to life threatening, but all are treatable with antibiotics if properly diagnosed. Ectoparasites, specifically ticks, can also carry and infect humans with viral infections. An example of this is tickborne encephalitis (TBE). The TBE virus is found in forested areas throughout eastern Europe and Asia. Most cases of TBE are subclinical and are not detected, but in certain cases, TBE can cause severe disease and death. There is a vaccine available for TBE and it is recommended for people who live or travel in high-risk areas for long periods. While it is difficult to estimate the global impact of ectoparasite and ectoparasitically transmitted disease, there is no doubt that ectoparasites have been, and will continue to be, associated with human disease. Despite advances in hygiene-related prevention and antibiotic treatments, ectoparasites, like many other emerging and reemerging diseases, are increasingly resistant to the medical treatments available, including the safest insecticides and repellants. As human habitation encroaches farther into ectoparasite habitats and as humans live in more densely populated communities, it is likely that ectoparasite-related illness will only increase. SEE ALSO: Lyme Disease; Parasitic Diseases. Bibliography. Eugene Braunwald, et al., eds., Harrison’s
Principles of Internal Medicine, 15th ed. (McGraw-Hill, 2001); J. H. Diaz, “The Diagnosis, Management, and Prevention of Common Ectoparasitic Infections,” Journal of the Louisiana State Medical Society (v.158/2, 2006); J. H. Diaz, “The Epidemiology, Diagnosis, Management, and Prevention of Ectoparasitic Diseases in Travelers,” Journal of Travel Medicine (v.13/2, 2006). Barry Pakes, M.D., M.P.H. University of Toronto
Ecuador Ecuador is located on the northwestern edge of South America, with a coast on the Pacific Ocean. The famed Galapagos Island, part of Ecuadorian territory, lays 965 kilometers (600 miles) offshore. The country was a Spanish colonial possession until 1821 and has never really found political or economic stability. Economic disparity is wide in Ecuador, with most of the money and power in the hands of those of European ancestry, while mesitzos and indigenous peoples live in abject poverty. The population of Ecuador is estimated at around 13,756,000 and growing at 1.55 percent annually. The birth rate is 21.91 births per 1,000, with a death rate of 4.21 deaths per 1,000 and a net migration rate of minus 2.16 migrants per 1,000. The population is mostly young: median age is 24 years, and 41 percent of the population is under the age of 18. Life expectancy at birth is currently 73.74 years for males and 79.63 years for females. Ecuador has one of the most unequal distributions of wealth in the world. It is estimated that the richest 20 percent of Ecuadorians hold 50 percent of the nation’s wealth, while the poorest 20 percent hold only 5 percent. A 2004 survey found that the majority of the urban poor subsist on $2.70 a day, while indigenous poor in the rural areas live on a mere $1.30. This inequality had heavy implications for public health within the country. Ecuador still has a significant burden of communicable disease within its borders. Malaria is common through the country, as is dengue fever in the costal regions. Cases of Chagas disease began in the early 1990s. There have been occasional reports of jungle yellow fever over the past two decades. Rabies and other zoonotic diseases are endemic throughout the country. There are sporadic cases of leprosy. Acute respiratory disease affects thousands each year. Cholera cases dropped in the 1990s, but diarrhea and other gastrointestinal diseases are common. HIV/AIDS impacts 0.3 percent���� ����������� of the adult population, or an estimated 23,000 people. There have been about 1,000 AIDS-related deaths since the virus first emerged. Political problems have hampered the country’s efforts to institute education and prevention programs, and only 34 percent������������� �������������������� of those in need are taking antiretroviral drugs. However, the Joint United Nations Programme on HIV/AIDS (UNAIDS) notes that there have been improvements in care in recent years, particularly for at-risk women and children.
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Noncommunicable diseases and external issues also take their toll on the population. Cardiovascular disease is common, and often stems from other degenerative conditions, such as rheumatic fever. With 63 percent of Ecuadorians living in urban areas, accidents and violence are the frequent cause of hospital admissions. Its geographic location leads to death, disease and injuries from a variety of natural disasters, including floods, earthquakes, and volcanic eruptions. Infant and child mortality dropped between 1990 and 2005, with 25 deaths per 1,000 for children aged 1 to 5 years and 22 deaths per 1,000 for those under the age of 1. Immunization rates have risen to 94 percent. Malnutrition remains an issue, particularly among indigenous children. Twelve percent of children are classified as underweight, with 26 percent showing signs of stunted growth from long-term poor nutrition. Approximately 5.5 percent of Ecuador’s Gross Domestic Product goes to healthcare, and the country spends about $127 per capita. There is both a private and a public healthcare system. An estimated 18,000 doctors and 19,500 nurses work within the country, augmented by over 1,000 midwives. There are about 14 hospital beds for every 10,000 people. SEE ALSO: Diarrhea; Malaria. Bibliography. “Ecuador,” CIA World Factbook, www.cia.
gov/library/publications/the-world-factbook/geos/ec.html (cited June 2007); “Ecuador—Overview—An inequitable society,” UNICEF, www.unicef.org/ecuador/overview_2834. htm (cited June 2007); “Ecuador,” UNAIDS: The Joint United Nations Programme on HIV/AIDS, www.unaids.org/en/Regions_Countries/Countries/ecuador.asp (cited June 2007); World Health Organization, “Core Health Indicators/WHO 2007,” Core Health Indicators/WHO 2007, www.who.int/ whosis/database/core/core_select.cfm (cited June 2007). Heather K. Michon Independent Scholar
Edema Edema is an increase in interstitial fluid in any organs and used to be called dropsy or hydropsy. It generally manifests itself in a swelling of the feet and the ankles,
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but can occur in any organ or tissue in the body. Technically, it can also appear in plants where plant organs swell after an excessive accumulation of water. The production of interstitial fluid in the body is usually kept in balance but occasionally it can change through increased secretion of fluid into the interstitium or when there is impaired removal of the fluid. Edemas in some parts of the body are affected by gravity and this is known as peripheral edema or dependent edema. Gravity means that for people who spend much of their time upright, excess fluid often ends up in the ankles or feet, resulting in swelling there. However, for bedbound people, the first instance of edema can often be sacral edema. The main causes of peripheral edema include the high hydrostatic pressure on the veins, which leads to general inflammation, a poor reabsorption of fluids, low oncotic pressure, or an obstruction to the system of draining the lymph glands. In the case of pressure on the veins, it may originate from long periods in the same position (such as on long-haul flights), or the use of tight knee pads, or the wearing of tight jeans. This might lead, in the most extreme cases, to deep vein thrombosis, resulting from venous obstruction, congestive heart failure, or varicose veins. Low oncotic pressure may result in cirrhosis, renal protein loss, or even malnutrition. The obstruction of the lymph glands usually leads to infections but can also lead to fibrosis after surgery, and even cancer. It is also possible that edema might lead to allergic conditions such as angioedema. Although the symptoms of edema have been well known since ancient times, they were explained by the Greeks and the Romans by their belief in “humors” in the body, who saw an imbalance in them as the cause of swelling. Gradually, the knowledge of edemas increased with Herman Elwyn writing about it in 1929, and Cecil Drinker producing a major work in 1950. SEE ALSO: Cirrhosis. Bibliography. Cecil K. Drinker, Pulmonary Edema and
Inflammation (Harvard University Press, 1950); Herman Elwyn, Edema and Its Treatment (Macmillan, 1929); Alfred P. Fishman and Eugene M. Renkin, Pulmonary Edema (American Physiological Society, 1979). Justin Corfield Geelong Grammar School, Australia
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Egypt Egypt is one of the oldest civilizations in the world and has the largest population (78,887,007) of all Arab countries. Today, the government is struggling to return Egypt to a position of economic viability. Health services and free education have deteriorated, resulting in a less healthy population where large segments are unemployable. A ����������������������� per capita income of $3,900 places Egypt 146th in world incomes. Some 32 percent of the population is involved in agriculture, much of it subsistence. Nearly 10 percent (9.5 percent) of the work force is unemployed. One-fifth of Egyptians live in poverty, and in some areas as many as 58 percent are severely impoverished. Three percent of Egyptians live on less than $1 a day. Some ����� estimates place the number of Egyptians outside the healthcare system because of residency in informal areas at 48 million. In Cairo, around two million people live in squatter settlements or slums. It is believed that some 12 million Egyptians live in shacks, garages, mosques, and under staircases. Other impoverished Egyptians have taken up residency in the small one- and two-room houses built in cemeteries for temporary use by families visiting the dead. Income ������� disparity also exists, and Egypt ranks 34.4 on the Gini index of inequality. The top 10 percent of the population claims a fourth of all resources while the bottom 10 percent share only 4.4 percent. The United Nations Development Programme’s (UNDP) Human Development Report ranks Egypt 111th in the world in overall quality of life issues. While health insurance is readily available to more affluent Egyptians, it is beyond the reach of many Egyptians, and the government has not been able to breech this divide. There is a major problem with the quality of healthcare received by poor Egyptians. Three percent of total government expenditures are directed toward healthcare. The government designates 5.8 percent of the total Gross Domestic Product (GDP) for healthcare, and $235 (international dollars) per capita are expended in this area. Government funding provides 42.6 percent of all healthcare funding; and 27.1 percent of that total is earmarked for social security, which provides monthly allowances to orphans, divorced individuals, the elderly, and the disabled. The private sector provides 57.4 of all healthcare expenditures, and 93.2 percent
Health services in Egypt have deteriorated, resulting in a less healthy population where large segments are unemployable.
of private spending is out of pocket. There are 0.54 physicians, 2.00 nurses, 0.14 dentists, and 0.10 pharmacists per 1,000/ population in Egypt. Ranking in the mid-range on life expectancy, Egyptians can expect to live 71.29 years. On average, women outlive men by five years. Literacy is relatively low in Egypt, at 57.7 percent, and there is an appreciable difference in male (68.3 percent) and female (46.9 percent) literacy. Egypt has limited fresh water resources outside the Nile area. However, all urban residents and 97 percent of rural residents have sustained access to safe drinking water. Less than 60 percent of rural Egyptians have access to improved sanitation as compared to 84 percent of urban residents. Women produce approximately 2.83 children each in Egypt. Between 1970 and 1990, the fertility rate dropped from 6.1 to 4.3. This is due in great part to the fact that women are marrying later and 60 percent of Egyptian women now use birth control. Trained personnel are present at 69 percent of all births, and 69 percent of women receive antenatal care. The adjusted maternal mortality rate is 84 deaths per 100,000 live births. The rural mortality rate is almost double that of urban areas. Infant mortality stands at 31.33 deaths per 1,000 live births, the 79th highest infant mortality rate in the world. However, some significant success has been made. Between 1990 and 2004, infant mortality plummeted from 76 to 26 deaths per 1,000 live
births, and under-5 mortality declined from 104 to 36 deaths. Twelve percent of all infants are underweight at birth, and nine percent of under-5s fall into this category. Four percent suffer moderate to severe wasting, and 16 percent experience stunting. The government subsidizes all required vaccinations. Consequently, immunization rates are high, with 98 receiving diphtheria, pertussis, and tetanus (DPT1) and tuberculosis vaccines, and 97 percent receiving DPT3, polio, measles, and hepatitis B vaccinations. Around 29 percent of under-5s receive necessary oral rehydration therapy when needed. Seventeen percent of Egyptian children are not enrolled in primary school. While 88 percent of males attend secondary school, only 82 percent of females do so. Six percent of children between the ages of 6 and 14 are in the labor force, and their presence is particularly prevalent in the cotton industry. ���������������������� Over half of Egyptian children suffer from anaemia, and a fifth of all children suffer from vitamin deficiencies. The health of Egypt’s street children is particularly precarious. A joint United Nations Children’s Fund (UNICEF) and World Food Program study revealed that 66 percent of these children suffer from substance abuse. Thirty percent of them have never attended school, and 70 percent have dropped out. ���������������������������������� Female genital mutilation/cutting is still common in Egypt, and 95 percent of urban and 99 percent of rural females undergo this procedure. While Egypt is not experiencing HIV/AIDS to the same extent as many of the poorest African nations, the country has a 0.1 percent adult prevalence rate. Some 12,000 are living with the disease, and 700 have died. The first successful treatment of trachoma can be traced back to the ancient Egyptians, but the disease continues to affect modern Egyptians. It is the leading cause of blindness among rural Egyptians, and 36.5 percent of rural children are suffering from active trachoma. In one rural community, one out of every five adults is also afflicted with the completely preventable disease. The Carter Center of Emory University works with other international agencies to eradicate schistosomiasis and Guinea worm disease in rural Egypt. A major avian influenza epidemic hit Egypt in 2006. See Also: Saudi Arabia; United Arab Emirates. Bibliography. Central Intelligence Agency, “Egypt,”
World Factbook, www.cia.gov; Commission on the Status
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of Women, “Egypt”, www.un.org; Peter Kandela, “Alexandria: Oversupply of Doctors Fuels Egypt’s Health-Care Crisis,” The Lancet (v.352/9122, 1998); Helen Chapin Metz, ed., Egypt: A Country Study (Federal Research Division, 1991); Hania Sholkamy and Faha Ghannan, eds., Health and Identity in Egypt: Shifting Frontiers (American University in Cairo Press, 2004); Social Watch, “Egypt,” www. socialwatch.org; Khalid F. Tabbara, “Blinding Trachoma: The Forgotten Problem,” British Journal of Ophthalmology (v.85/12, 2001). UNICEF, “Egypt,” www.unicef.org. Elizabeth R. Purdy, Ph.D. Independent Scholar
Ehlers-Danlos Syndrome Ehlers-Danlos syndrome (EDS) is a collection of genetic diseases that cause instability of the collagen or its partner proteins, and therefore of connective tissue. Common features include joint hyperextensibility and elastic skin prone to tearing and bruising. One feature which may indicate EDS is the Gorlin sign, which is the ability to reach the tip of the nose with the tongue. There are many disorders of the connective tissue. Some are genetic, some are environmental, and some are idiopathic, meaning they don’t have a known cause. Genetic connective tissue disorders include EhlersDanlos syndrome, affecting collagen or the proteins that interact with collagen to provide stability to the connective tissue. EDS is panethnic and affects males and females equally. Overall, approximately one in 5,000 individuals has some form of EDS. Several genetic diseases that result in defective collagen are classified as EDS. EDS can be caused by other genetic mutations as well, but the major ones identified so far have been grouped into six classes, each containing one or more ‘types’. Initially there were eleven types of EDS; in 1997, scientists came together to simplify the system and combine like disorders into types. Today, former EDS types 1 and 2 are called Classical EDS. Classical EDS involves a mutation in type V or type I collagen, and results in joint hypermobility, dislocation or subluxation (partial or incomplete dislocation) of joints, highly elastic and velvety skin which readily bruises and tears, and often mitral valve prolapse, a cardiac condition. A woman
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with Classical EDS is at mortal risk if she becomes pregnant. Classical EDS is documented at a frequency of fewer than five in 100,000 patients. Former type 3 EDS is called Hypermobility. These patients also have joint hypermobility, dislocation, and subluxation; and often have mitral valve prolapse. Hypermobility is caused by a dominant mutation in one of two autosomal (non sex-chromosomal) genes. Former type 4 is called Vascular EDS. In Vascular EDS, the type 3 collagen gene (also autosomal) has a dominant mutation found in one in 100,000 people. Vascular EDS primarily affects the vasculature of individuals. Small blood vessels are weakened, as well as organ membranes, and people with Vascular EDS often do not live greater than 40 years. A common occurrence in people with this form of EDS is an aneurysm. Like other forms of EDS, Vascular EDS causes elastic, velvety skin which easily bruises and tears, and it can appear translucent. Women with Vascular EDS are also in mortal risk if they become pregnant. Former type 5 is not a major class of EDS; former type 6 is called Kyphoscoliosis. These individuals develop progressive scoliosis due to a rare, autosomally recessive mutation in their lysyl hydroxylase gene. Former types 7A and 7B EDS are called Arthrochalasis, and are due to a defect in type I collagen. The most affected joint in Arthrochalasis is the hip; these individuals often develop osteoarthritis. Former type 7C is the rarest of the major EDS classes. It is called Dermatosparaxis, and results in elastic, fragile skin which becomes progressively more brittle with age. There are five more types of EDS that are all classified as Other. These types are the former types 5, 8, 9, 10, and 11. Combined symptoms of these types include low blood pressure, frequent blood clotting, periodontal complications, and loose joints. Currently, there is no known cure for EDS; rather, patients manage their disease with supportive treatment. A major management step is protecting the joints from damaging impacts or dangerous stretching. Too much impact or stretching could lead to arthritis as well as dislocation of the joints. People with EDS must be vigilant in their eye care as the whites of the eyes may be weakened. Additionally, the skin must be protected from the sun. SEE ALSO: Cardiology; Connective Tissue Disorders; Mar-
fan Syndrome; National Institutes of Health (NIH).
Bibliography. Peter Beighton, ed., McKusick’s Heritable
Disorders of Connective Tissue (C. V. Mosby, 1993); Kenneth J. Carpenter, The Official Patient’s Sourcebook on EhlersDanlos Syndrome: A Revised and Updated Dictionary for the Internet Age (Icon Health Publications, 2002); ICON Health Publications, Ehlers-Danlos Syndrome: A Medical Dictionary, Bibliography, and Annotated Research Guide to Internet References (ICON Health Publications, 2004). Claudia Winograd University of Illinois
Ehrlich, Paul (1854–1915) Born on March 14, 1854, in modern-day Poland (then part of Germany) to Ismar and Rose Weigert Ehrlich, Paul Ehrlich created the first-known cure for syphilis, a disease later treated by antibiotics, and he discovered the process of chemotherapy, using chemicals to combat disease. Furthermore, because of his blood sample research, hematology became a scientific discipline. In 1908, Ehrlich received the Nobel Prize for Physiology or Medicine with Ilya Mechnikov for his discoveries about the human immune system. Ehrlich studied at the Universities of Breslau, Strasbourg, Freiburg-im-Breisgau, and Leipzig, earning his Ph.D. in medicine in 1878. He worked at the Berlin Medical Clinic, staining tissues with dyes, and discovering that all dyes were basic, acid, or neutral. Even today, the method for staining the tuberculosis bacteria is a derivative of Ehrlich’s process. In 1882, Ehrlich became a professor at the University of Berlin. In 1883, Ehrlich married Hedwig Pinkus, with whom he had two daughters. Contracting tuberculosis, possibly through his laboratory work, Ehrlich recuperated in Egypt, staying there from 1886 until 1888. In 1890, he began his breakthrough immunological studies at the new Institute for Infectious Diseases. He collaborated with two bacteriologists to find a cure for diphtheria. In 1894, their antitoxins began being used on children. Through this process, they recognized the need for dyes that stained bacteria but not other cells to help them combat disease; as they sought out these dyes, Ehrlich discovered that arsenic helped people overcome syphilis.
El Salvador
In 1897, Ehrlich was chosen as the public health officer in Frankfurt-am-Main; in 1899, he became the director of the Royal Institute of Experimental Therapy and of the Georg Speyerhaus; there, he founded the basis of chemotherapy. He called these chemicals “magic bullets” for their ability to target disease in the human body. During the later years of his career, Ehrlich experimented with methods to defeat tumors. The street where the Royal Institute was located was renamed Paul Ehrlichstrasse, which was reversed during the Hitler years in Germany. After World War II ended and the region became part of Poland, the street was named Ehrlichstadt. Ehrlich had a minor stroke in 1914. On August 20, 1915, he suffered a fatal one. SEE ALSO: Chemotherapy; Diphtheria; Sexually Transmitted Diseases. Bibliography. “Paul Ehrlich,” www.cartage.org.lb/en/
themes/Biographies/MainBiographies/E/Ehrlich(cited July 2007); “Paul Ehrlich,” Nobel Lectures, Physiology or Medicine 1901–1921 (Elsevier, 1967); “Paul Ehrlich: The Nobel Prize in Physiology or Medicine 1908,” nobelprize.org (cited July 2007). Kelly Boyer Sagert Independent Scholar
El Salvador El Salvador is located on the Pacific Coast of Central America, surrounded by Guatemala and Honduras. It is the smallest country in Central America, the most heavily industrialized, and the only one that does not have a coastline on the Caribbean. It is a mountainous country poetically called the Land of Volcanoes—a geological happenstance that leads to frequent earthquakes, while its geographical location makes it vulnerable to tropical storms and hurricanes. In 1998, the remnants of Hurricane Mitch dumped an enormous amount of rain on the country, leading to massive flooding that killed 300 and left at least 30,000 homeless. The country has not been free from man-made disasters either: A civil war from 1980 to 1992 took the lives of more than 75,000 Salvadorans before peace was declared.
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El Salvador has a population of 6.82 million and is growing at 1.72 percent annually. The birth rate is 26.61 births per 1,000 people and the death rate is 5.78 per 1,000 people. The migration rate is minus 3.61 migrants per 1,000. An estimated 3.1 million Salvadorans are living outside the country. Although the country has a well-developed industrial sector, the economy remains poor. Almost 17 percent of the Gross Domestic Product in 2005 came from remittances, money wired back into the country from emigrants. The agricultural sector has been hit by droughts, deforestation, soil erosion, and the collapse of world coffee prices. Per capita income in $4,700 a year, but 32 percent of the population live below the poverty line. The country recently entered into the Central American Free Trade Agreement (CAFTA), which it hopes will revitalize the country’s economy. Average life expectancy at birth is 67.88 years for males and 75.28 years for females; healthy life expectancy is 57.2 for men and 62.36 for women. Infant mortality is 24 deaths per 1,000 live births. Another 28 of every 1,000 children die between the ages of 1 and 5. Maternal mortality is 150 deaths per 100,000 live births. Sixty-eight percent of women receive prenatal care and 92 percent have a trained attendant present at delivery. The Salvadoran diet is based on rice and beans, and small cornmeal cakes called pupusas, which are filled with farmer’s cheese, beans, and fried pork fat or other meats. Even with the addition of local fruits and vegetables, this diet lacks essential vitamins and nutrients. A quarter of Salvadoran children are malnourished. There has been a concerted effort to increase childhood immunizations, and common diseases such as measles and polio have been all but eradicated in recent years. Civil war, natural disasters, and the search for work outside the country has led to 180,000 children under the age of 17 living as orphans. About 82 percent of the population have clean water to drink and 63 percent have access to sanitary facilities. Nevertheless, common waterborne and communicable diseases are under control within El Salvador, with only sporadic outbreaks of illnesses such as cholera. Leprosy is becoming increasingly rare. Salvadorans are more likely to die in accidents; from heart disease, cancer, and pneumonia; or in natural disasters than from an infectious disease. There is a nationwide monitoring network in place to deal
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with outbreaks; for example, dengue fever—both classic and hemorrhagic—broke out in 2006 and triggered a massive government response to stem the spread of the illness. Tuberculosis is on the rise, with 60 cases per 100,000 people. The HIV/AIDS rate is 0.7 percent, with 30,000 people living with the virus and 2,200 having died since it first emerged. Studies have shown that 89 percent of the cases were sexually transmitted, and the government has launched education campaign across the country. The government allocates $84 per person on healthcare. It is making strides to increase access to both urgent and preventative care but remains hampered to some degree by the poor economy. The World Health Organization counted 7,938 physicians and 5,103 nurses working in the country in the year 2000. SEE ALSO: Healthcare, South America. Bibliography. John R. Eriksson, Margaret Arnold, Alcira
Kreimer, El Salvador: Post-Conflict Reconstruction (World Bank Publications, 2000); Aldo Lauria-Santiago, and Leigh Binford, Landscapes of Struggle: Politics, Society, and Community in El Salvador (University of Pittsburgh Press, 2004.) Heather K. Michon Independent Scholar
Elbow Injuries and Disorders Musculoskeletal injuries are the most frequently occurring medical conditions in the United States. Although elbow injuries are among the least common musculoskeletal problems, their impact on daily life and an individual’s independence can be quite significant. The most common elbow injuries can be broken down into two main categories: overuse and trauma. Anatomy In order to understand disorders of the elbow, an appreciation for the basic anatomy is required. The elbow joint consists of the articulation of the upper arm, or humerus, with the two bones of the forearm, the radius and ulna. The radius and ulna articulate with the lateral and medial portions of the humerus (termed condyles) in a manner allowing for hinge-like movement,
as well as pivoting movements termed pronation and supination. The elbow joint movements are stabilized posteriorly by the olecranon process of the ulna bone, and laterally and medially by two major ligament complexes. Bursa, or fluid filled sacs, facilitate movement by reducing friction between elbow components. Overuse Humeral epicondylitis is the most common elbow problem and is a result of overuse of the elbow joint. The associated pain is a result of inflammation of the area where the forearm muscles attach to the humerus. The inflammation is more commonly on the lateral humerus (aka “tennis elbow”), but can also occur on the medial side (aka “golfer’s elbow”) or posteriorly around the triceps tendon. These conditions are most common between the age of 30 and 50 in those who perform repetitive hand or arm movements as a part of their profession. Repetitive forceful extensions of the elbow can also cause bony collisions between the olecranon and the humerus, leading to a condition called posterior impingement syndrome. The bones will often thicken and or fragment in response to the trauma, leading to pain over the olecranon process, limited range of motion, and swelling. Overuse of the elbow can also lead to inflammation of the bursa or muscle tendons, conditions termed bursitis and tendonitis, respectively. Bursitis most commonly involves the olecranon bursa, and tendonitis most commonly involves the biceps or triceps tendons. Trauma Trauma to the elbow joint can typically result in two types of injury: fracture or dislocation. Elbow dislocation often results from falling on an outstretched arm. Dislocation in any direction is possible, but posterior movement of the forearm bones is most common. A dislocated elbow will commonly be held at a 45-degree angle and will often have a clear deformity on or around the olecranon process. In children, a partial dislocation called radial head subluxation is possible. This occurs when a child’s arm is forcibly pulled while in the extended position, causing the radial head to slip underneath the annular ligament (part of the lateral ligament complex that stabilizes the radial head articulation with the ulna). Elbow fractures most commonly involve the radial head or olecranon process. Radial head fractures ac-
Elder Abuse
count for a third of elbow fractures, and often result from falling on a partially flexed but outstretched arm. Symptoms include point tenderness on the radial head, pain with pronation and supination, decreased range of motion, and possibly swelling. Olecranon process fractures generally result from direct trauma to the posterior elbow, often from falling backward. Alternatively, and less commonly, the olecranon suffers a stress fracture from forceful triceps muscle contraction while the arm is flexed, as in throwing a baseball. Much less commonly, the humerus may be fractured. Fractures above the condyles are termed supracondylar fractures, and are most common in kids under the age of 10. Although rare, condylar fractures can also occur. It is important to consider that dislocations or fractures of the elbow can lead to secondary injury of the nerves or vessels that traverse the elbow joint. This includes the brachial, radial, and ulnar arteries, and the radial, ulnar, and median nerves. These structures target the forearm and hand, and injuries can thus lead to downstream deficits in sensation, motor function, or blood supply. One such syndrome resulting from ulnar nerve compression is called cubital tunnel syndrome, and causes tingling and weakness in the hand. This discussion of elbow disorders is not comprehensive, and elbow pain or dysfunction can be caused by numerous other factors such as arthritis, infection, or cancer. SEE ALSO: Arthritis; Bursitis; Fractures; Occupational In-
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1 million elderly Americans are abused by their relatives, and with the aging of the population worldwide, elder abuse will naturally increase if not prevented. Abused seniors are at higher risk for depression and death compared to nonabused seniors. There is currently enough evidence to affirm that elder abuse is a worldwide problem, and the various existing studies have found a surprisingly high incidence of it, ranging from 3 to 6 percent of people above 65 years of age being abused annually. That puts elder abuse in the present developmental agenda. The perpetrators of elderly abuse are generally spouses or adult children, although they can be other family members and even informal or paid caregivers. While some behaviors are clearly abusive, the line that separates abuse from normal behavior may be tenuous. For example, people often cross this line when intending to control daily activities and schedules of their lucid but frail senior relative who could well decide upon his or her activities and maintain autonomy even if dependent on others to perform them. In that sense, caregivers for elderly persons who have chronic medical problems may not realize abusive behaviors or may be isolated enough to lose contact with other people and other caregivers, losing insight of what is normal. The harmful effects of caregiver burden are well studied and there are many options to relieve this burden, from services of care to the patients to services of care to the caregivers.
Elder Abuse
Risk Factors There are known risk factors for elder abuse. For the victim, they include impairment (physical, functional, and cognitive impairments) and social isolation. On the abuser’s side, they include substance abuse, psychiatric disorders, history of violence, stress, and dependence on the victim. A very common example of abuse includes administering medication by force. Abandoning a dependent elder or leaving him or her unattended so as to endanger his or her life is also a very common form of abuse. Approximately 60 percent of elder abuse is toward women, as is the majority of elder homicides, which suggests that domestic violence in old life may be a continuation of wife abuse in the past.
Elder abuse is any act or lack of appropriate act whose consequences are harm or distress to an elderly person. In the United States, it is estimated that each year
Types of Elder Abuse Elder abuse may be classified in neglect, for example, when a person is denied food, basic medication, heat,
juries; Osteoarthritis; Rheumatoid Arthritis; Sports Injuries; Wrist/Arm Injuries and Disorders. Bibliography. B. Morrey, The Elbow and Its Disorders,
3rd ed. (Saunders, 2000); M. Pecina and I. Bojanic, Overuse Injuries of the Musculoskeletal System (CRC Press, 1993); C. K. Stone and R. L. Humphries, Current Emergency Diagnosis and Treatment, 5th ed. (McGraw-Hill, 2004). David J. Lunardini University of Virginia
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clothing or comfort; rights abuse, when civil and constitutional rights of mentally capable elderly people are denied; financial, when the senior’s property, money, or other valuables are used illegally or with no authorization of the elderly person; physical, as in direct physical aggression, restraining or providing wrong medication or dosage; psychological, such as shouting at an elderly person, humiliating or frightening him or her in any way; and sexual, for example, by forcing the elderly person to engage in any nonconsensual sexual activity. One form of elder abuse must be stressed: doing any action or having the senior do any action that requires his or her consent in the case where the elderly person is not able to consent because of mental incapacity is to be considered elder abuse. It may fall into any of the above categories and can include transferring of power of attorney, changing heirs in one’s will, transferring property, engaging in sexual activities, and so on. Diagnosis and treatment Social isolation is commonly linked to elder abuse and can make the suspicion difficult, as abused elders tend to visit their health professionals less frequently, but also because the abuser often controls the victim’s access to other people and it is estimated that only one in 14 cases are revealed. Professional unawareness and lack of specific training may contribute to that picture; but even though symptoms and signs of abuse may be confounded with disease, certain clinical situations are suggestive of elder abuse and may be recognized by the experienced health professional. This is important because the physician or other healthcare practitioner may be the only person other than the abuser that the victim may be able to have contact with, and the American Medical Association has published guidelines for the identification of elder abuse. Maintaining a high level of suspicion is also important for its detection. The complexity of the situation makes a wide interdisciplinary approach essential, as is determining if the mistreatment was an isolated event or part of a chain of abusive actions. If the patient is mentally competent, he or she must be informed of the available options and decide what to do. If the patient is mentally incapable, then it is up to the healthcare team to decide what to do. A nonabusing caregiver of a victim of abuse may also require assistance: the psychological hazards of
Studies have found an incidence of elder abuse ranging from 3 to 6 percent of people above 65 years of age annually being abused.
family violence are high, possibly constituting even a physical health menace in older caregivers. Ideal treatment recognizes the multidimensionality of causes and consequences of elder abuse and, thus, the patient would be ideally treated by an interdisciplinary team, which may include physicians, nurses, social workers, psychologists and other therapists, lawyers, and law enforcement officials. Any previous failure should be investigated in order to improve any further intervention’s chance of success. Ethical Dilemmas Physicians and health workers worldwide are in general traditionally bound to keep secret the information gathered during their practices and respect the patient’s right to decide if some information is disclosed to the public. The importance of elder abuse, however, has prompted the issuing of protective laws in different countries that compel anyone aware of elder abuse to notify a competent agency. Finally, in many countries, such agencies are still incipient and incapable of handling the problem to its real extent. This situation may put health workers in an ethical dilemma in cas-
es where the abused senior does not want to turn the situation public: while the professional rules command them to respect those wishes, the law obliges them to report the abuse. Another problem in many countries is that the services for abused elderly people are very incipient and not enough for every case, and reporting the abuse may only cause the victims to loose access to the health service where the abuse was reported. Elder abuse is an important public health issue; as the percentage of elderly within the populations increase all over the world, its incidence is expected to grow despite any effort already made to prevent it. While the incidence of elder abuse has varied between 3 to 6 percent a year on those above 65 years in different studies, the real picture may be even worse because many cases may not be reported at all. Elder abuse is often difficult to detect for many health professionals and may be perpetrated even without the intention of the aggressor to do so. If health professionals need continuous education for better detection of the problem, the entire society must discuss what solution to give to those cases already identified. SEE ALSO: Child Abuse; Geriatrics. Bibliography. American Medical Association, Diagno-
sis and Treatment Guidelines on Elder Abuse and Neglect (American Medical Association, 1992); C. McCreadie, G. Bennett, and A. Tinker, “General Practitioners’ Knowledge and Experience of the Abuse of Older People in the Community: Report of an Exploratory Research Study in the Inner London Borough of Tower Hamlets,” British Journal of General Practice (v.48, 1998); K. Pillemer and D. Finkelhor, “The Prevalence of Elder Abuse: A Random Survey,” Gerontologist (v.28, 1988). Thiago Monaco, M.D., Ph.D. University of SÃo Paulo Medical School, Brazil
Electromagnetic Fields Electromagnetic fields (EMFs) are physical fields that are produced by electrically charged objects. Electric fields are produced by stationary charges and magnetic fields are created when electric current flows. These fields interact with close-by charged objects thus affect-
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ing their condition. EMFs can be viewed as the combination of an electric field and a magnetic field and are defined by their frequency and wavelength. The frequency simply describes the number of oscillations or cycles per second, while the term wavelength describes the distance between one wave and the next. Electromagnetic fields include static fields such as the Earth’s magnetic field and fields from electrostatic charges, electric and magnetic fields from the electricity supply at power frequencies, and radio waves from television, radio and mobile phones, radar, and satellite communications. It is important to separate two types of EMFs: Some electromagnetic waves carry so much energy that they have the ability to break bonds between molecules and these are called ionizing radiation. Fields whose energy is insufficient to break molecular bonds are called non-ionizing radiation and include visible light, infrared, and radio waves. Due to the increase in the human use of technologies using EMFs, this is an area that has know an exponential growth, which has also lead to new complaints and concerns. One of the most common is connected with the association between power lines and cancer. Research results are still controversial, but some studies point to an increase in the numbers of early cancer in people living downwind of power lines. Although there is no certain explanation for this higher rate (some even believe it might be just a “statistical artifact”), one that has recently known more supporters has to do with “corona ion” effects. Researchers have proposed that the air immediately surrounding a high-voltage power line becomes ionized by the electric field, thus combining with pollutants in the air, giving rise to charged airborne particles. If inhaled by someone closely exposed, they may be deposited in the lungs and eventually develop cancer. Other sources of electromagnetic fields that have spawned controversy are mobile phones. No conclusion has been reached when assessing whether the radiation arising from mobile phones and base stations is connected to disease. Other common sources of EMFs are wireless solutions, which are being implemented throughout the environment. Its impact is still to be assessed. On the account of this increase in exposure, a number of individuals have reported a variety of health problems that they relate to exposure to EMFs. This has been
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known as “electromagnetic hypersensitivity” and symptoms range from mild to severe, including skin redness, tingling, and burning sensations to fatigue, dizziness, nausea, heart palpitation, and digestive disturbances. The World Health Organization is currently conducting research to determine prevalence and ways to lower the impact of EMFs on those with this condition. SEE ALSO: Childhood Cancers; Environmental Health;
Leukemia; Radiation Exposure.
Bibliography. BBC News, “Cancer Rise Linked to Power
Lines,” news.bbc.co.uk/2/hi/science/nature/933678.stm (cited September 2000); Independent Expert Group on Mobile Phones, “Stewart Report,” www.iegmp.org.uk/ (cited May 2000); World Health Organization, “Electromagnetic Hypersensitivity,” www.who.int/mediacentre (cited December 2005). Ricardo Mexia, M.D. Independent Scholar
Electrophysiology Electrophysiology is a study of the electrical properties that exist within biological cells and tissues, and this has developed to include the ability of these cells to react to electrical current. To do this, researchers have had to measure the change of voltage and also the flow of electric current covering a variety of scales, ranging from places such as the heart to single-ion channel proteins. The origin of electrophysiology goes back to the research of the German, Emil Heinrich Du Bois-Reymond, from Berlin who, during his work at the University of Berlin, decided to concentrate on electrical activity in nerve and muscle fibers. His initial work was on fish and that they were capable of generating electrical currents on their own. From this, he turned to researching electrical conduction along muscle and nerve fibers which led him into work on electrical stimulation of muscles. His work on nerve and muscle stimulation led to the two-volume work Untersuchungen über thierische Elektricität (Researches on Animal Electricity), the first volume being published
in 1848, and the second volume was not published until 1884. The books are still regarded as pioneers in the field of scientific electrophysiology. Du BoisReymond collaborated with Hermann von Helmholtz, Carl Ludwig, and Erich von Brücke; and his work was continued and developed by French physician Jacques-Arsène D’Arsonval from the University of Poitiers, Limoges, and Paris. D’Arsonval started to use electricity to treat skin and mucous membranes with his work being known as D’Arsonvalization. Traditionally, electrophysiology has involved the placing of electrodes on various biological tissues. These electrodes may range from needles and discs, and then to printed circuit boards, and even hollow tubes such as glass pipettes filled with electrolytes. The last of these, if small enough, have been used to pass electricity to a single cell, although sometimes it is has been found that it is not necessary for the electrode tip to physically touch the cell. The biological tissues can also vary considerably, ranging from living organisms, excised tissue, cells removed from excised tissue, artificially grown cells or tissue, or hybrids of these preparations. The main drawback of these traditional (or classical) practices has been that these techniques have only allowed electrophysiologists to observe the effect of an electrical current at a single point within the volume of the tissue. This has led to the development of optical electrophysiology with practitioners eager to overcome that drawback. This, in turn, resulted in work on a variety of related fields such as electroantennography (covering the olfactory receptors in arthropods), electrocardiography (for treatment of the heart), electroclography (for treatment of eyes), electrocorticography (for treating the cerebral cortex), electroculography (for treatment of the muscles), electroencephalography (for treatment of the brain), and electroretinography (for treatment of the retina of eyes). Electrophysiology relies on the accuracy of intracellar recording whereby scientists measure the voltage or current which crosses the membrane of the cell being treated. Research in this field resulted in Alan Lloyd Hodgkin, Andrew Fielding Huxley, and Australian Sir John Carew Eccles winning the Nobel Prize in Physiology or Medicine in 1963. Their research was largely conducted on the Atlantic squid, Loligo pealei, using the voltage clamp technique. Huxley was later knighted for his services to science, as was Alan Hodgkin. In
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to the effects of tobacco smoking than others, suggesting a genetic predisposition to develop chronic obstructive pulmonary disease (COPD).
Electromagnetic fields include magnetic fields from the electricity supply at power frequencies, and radio waves.
1967, Finnish-born Swedish physiologist, Ragnar Arthur Granit, and Americans George Wald and Haldan K. Hartline won the Nobel Prize for their work on the internal electrical changes which take place when the eye is exposed to light, the work on the chemistry of vision and the neurophysiological mechanisms of vision, respectively. Further work on electrophysiology has helped with a greater understanding of it. SEE ALSO: Electromagnetic Fields. Bibliography. John R. Heckenlively and Geoffrey B. Ar-
den, eds., Principles and Practice of Clinical Electrophysiology of Vision, 2nd ed. (MIT Press, 2006); Lynn SnyderMackler, Clinical Electrophysiology: Electrotherapy and Electrophysiologic Testing (Williams & Wilkins, 1989); Natalie Virag, Olivier Blanc, and Lukas Kappenberger, Computer Simulation and Experimental Assessment of Cardiac Electrophysiology (Future Publishing, 2001). Justin Corfield Geelong Grammar School, Australia
Emphysema Emphysema is a chronic and irreversible lung condition which affects 4.7/100,000 persons in the United States. The primary cause of emphysema is tobacco smoking; other causes include chronic exposure to toxins and fumes. Some patients are more susceptible
Physiology/Pathophysiology Emphysema is one of a group of conditions called COPD; these diseases obstruct airflow. During inspiration, air enters the lungs through the trachea (windpipe) to reach air passages known as bronchi. Bronchi repetitively branch into progressively smaller and smaller branches (envision an upsidedown tree, without the leaves) until finally reaching thin-walled structures called alveoli (tiny air sacks). The walls of the alveoli interface with the bloodstream (capillaries) where oxygen crosses over the alveolarcapillary membrane to enter the circulation. Oxygen is needed by all organs for normal function; when oxygen transfer ceases to occur, organs die. In emphysema, destruction of the alveoli occurs through repetitive exposure to toxins such as tobacco smoking; stimulation of inflammation and the action of enzymes (e.g., elastase), cause destruction of the alveolar supporting structures. Without the supporting structures, the alveoli balloon out and oxygen is unable to cross over to enter the bloodstream. The net effect of this is low oxygen in the blood stream, called hypoxemia. Administration of supplemental oxygen can be successful early on in helping to overcome low oxygen levels in the bloodstream, but eventually, as emphysema progresses, this may not be adequate to allow for maintenance of life. Alpha-1 antitrypsin deficiency is an inherited condition estimated to be responsible for only 1 to 2 percent of all cases of emphysema. These patients lack adequate amounts of the protein responsible for keeping an enzyme called elastase in check; left unchecked, elastase destroys healthy lung tissue. Alpha-1 antitrypsin is a protein produced by the liver; deficiency of this protein leads to development of emphysema and cirrhosis of the liver. Screening for alpha-1 antitrypsin should be undertaken in all patients with emphysema as recognition of genetic deficiency of this protein should cause the practitioner to carefully evaluate whether or not the patient should receive artificial supplementation. In addition, development of pulmonary hypertension (elevated blood pressure in the pulmonary blood vessels) commonly develops in patients with
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emphysema. This is often irreversible and can be quite debilitating, leading to failure of the right side of the heart (also called cor pulmonale). This is a common cause of death in patients with emphysema. Signs and symptoms of emphysema Signs and symptoms of emphysema include shortness of breath (also called dyspnea). Dyspnea is often initially noted only on exertion (i.e., walking, running) however, with progression, eventually will be present at rest. Coughing, with or without phlegm production are frequently noted, as is wheezing (a musical noise sounding similar to a deflating accordion, noted on exhalation). Because patients with emphysema are predisposed to recurrent infections in the lungs, the first time a patient is diagnosed with emphysema may be following development of a chest infection. Diagnosis Diagnosis of emphysema begins with suspicion. Emphysema is traditionally diagnosed by the performance of pulmonary function testing (also called spirometry or PFTs). Spirometry is the first test performed and confirmation of the results of spirometry is required; in such cases, patients are typically referred to pulmonary function laboratories for additional testing including lung volumes. Emphysema causes reduced lung function and in particular, air trapping. As opposed to asthma, which, during an acute exacerbation, also leads to typically temporary air trapping, the air trapping associated with emphysema is very much less likely, and typically does not, substantially resolve with bronchodilators. Bronchodilator challenge is performed when evidence of airway obstruction is noted on PFTs. Patients with asthma will typically demonstrate at least a 12 percent improvement in one or both parameters (FEV1 [forced expiratory volume in 1 second] and FVC [forced vital capacity]), whereas the great majority of patients with emphysema will not substantially improve with bronchodilator therapy. Patients with emphysema will also demonstrate an elevated residual volume (consistent with air trapping) and a reduced diffusion capacity for carbon monoxide (DLCO). All patients with emphysema should be evaluated for hypoxemia; this includes performance of either an arterial blood gas or oximetry at rest and with exertion. When discovered, hypoxemia must be treated
with oxygen supplementation as this is the only treatment shown to reduce mortality in emphysema. Patients with emphysema may require oxygen supplementation only with exertion. Patients with emphysema who plan to travel by airline or visit areas of high altitude, should consult with their physicians, as oxygen supplementation may be required during those periods, even if the patient has no documented need for oxygen supplementation otherwise. All patients with emphysema should undergo screening for alpha-1 antitrypsin, particularly when there is a family history of emphysema, or emphysema is diagnosed at an early age. The test for alpha-1 antitrypsin deficiency is a blood test; abnormal results should be confirmed by repeat testing. Chest X-rays performed in patients with emphysema, particularly advanced emphysema, typically demonstrate air trapping (enlarged lungs), and may show the presence of blebs. Other tests sometimes done in emphysema patients include computed tomography (CT) scans, and arterial blood gas (done to check for low oxygen levels). Treatment All patients with emphysema or at risk for emphysema, and who smoke should be aggressively counseled and assisted with smoking cessation programs. The most effective programs are those that are multidisciplinary including use of counseling along with nicotine supplementation (in the form of gum, nasal sprays, patches, or tablets). Few patients who quit “cold turkey” (sudden discontinuation of smoking without behavioral or pharmacologic intervention) will be successful long term. The mainstay of therapy of existing emphysema is the use of bronchodilators. Evidence-based treatment guidelines such as the GOLD guidelines provide a guide for the treatment of emphysema and include information for both patients and care providers. These guidelines were developed by the World Health Organization in collaboration with world experts in COPD and are updated frequently. Patients who are documented to have severe deficiency of alpha-1 antitrypsin should be evaluated for administration of supplementation. This therapy is costly and benefits versus risk and cost must be considered. Surgical intervention for very severe emphysema may include lung volume reduction surgery (where sta-
Employment Retirement Income Security Act (ERISA)
pling and removal of large, non-functional portions of the lung is undertaken) and lung transplantation. Both of these interventions are associated with increased morbidity (complications) and mortality (death) compared to medical therapy. Patients being considered for either of these therapeutic interventions should be evaluated by a recognized center of excellence. See also: Chronic Obstructive Pulmonary Disease
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SEE ALSO: Genetic Testing/Counseling. Bibliography. M. P. Roth, et al., A Familial Empiric Risk
Estimates of Inflammatory Bowel Disease in Ashkenazi Jews,” Gastroenterology (v.96/4, 1989). Barry Pakes, M.D., M.P.H. University of Toronto
(COPD);.
Bibliography. Centers for Disease Control and Pre-
vention, www.cdc.gov/nchs/fastats/emphsema.tm (cited July 2007); Emphysema—A Medical Dictionary, Bibliography, and Annotated Research Guide to Internet References (ICON Health Publications, 2004).
Sandra K. Willsie, D.O., FACOI, FACP, FCCP Kansas City Uiversity of Medicine and Biosciences
Empiric Risk Empiric risk refers to the chance that a particular event or disease will occur in a person, family, or population, based on experience or observation (empeira = experience), as opposed to predicting risk based on theoretical considerations or conjecture. For example, the empiric risk can be calculated for relatives of inflammatory bowel diseases (IBDs) sufferers based on observed population statistics. Among Ashkenazi Jews, the age-corrected empiric risk estimates for IBDs are 8.9 percent to offspring, 8.8 percent to siblings, and 3.5 percent to parents. These estimates can be used for both genetic counseling and genetic modeling. Empiric risk can also be expressed as a risk ratio. For example, first-degree relatives of prostate carcinoma patients have a summary recurrence risk ratio of 2.53. The concept of empiric risk is used to investigate multifactorial traits and events such as cancer. The empiric risk is not calculated but is an observed population statistic used to predict recurrence of a multifactorial trait in a family. The empiric risk increases with severity of the trait, the number of affected relatives, their sex, and degree of relatedness to the affected individual.
Employment Retirement Income Security Act (ERISA) Passed in 1974, the Employee Retirement Income Security Act (ERISA) is a federal law that sets minimum standards for most voluntarily established pension and health plans in private industry to provide protection for individuals in these plans. It requires plan administrators—the people who run plans—to give plan participants in writing the most important facts they need to know about their retirement and health benefit plans including plan rules, financial information, and documents on the operation and management of the plan. Some of these facts must be provided to participants regularly and automatically by the plan administrator. Others are available upon request. One of the most important documents participants automatically receive when becoming a participant of an ERISA-covered retirement or health benefit plan or a beneficiary receiving benefits under such a plan, is a summary of the plan, called the summary plan description (SPD). The summary plan description gives participants details with regard to what their plan provides and how it operates, such as the manner in which benefits are calculated, when benefits become vested, and how claims are filed. In addition to the summary plan description, the plan administrator must automatically give participants a copy of the plan’s summary annual report each year. This is a summary of the annual financial report that most plans must file with the Department of Labor. The summary annual report is available at no cost. To learn more about the plan assets, participants may ask the plan administrator for a copy of the annual report in its entirety. There have been a number of amendments to ERISA, expanding the protections available to health benefit participants and beneficiaries. One important
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amendment, the Consolidated Omnibus Budget Reconciliation Act (COBRA), gives workers and their families who lose their health benefits the right to choose to continue group health benefits provided by their group health plan for limited periods of time under certain circumstances such as voluntary or involuntary job loss, reduction in the hours worked, transition between jobs, death, divorce, and other life events. Qualified individuals may be required to pay the entire premium for coverage up to 102 percent of the cost to the plan. COBRA generally requires that group health plans sponsored by employers with 20 or more employees in the prior year offer employees and their families the opportunity for a temporary extension of health coverage (called continuation coverage) in certain instances where coverage under the plan would otherwise end. COBRA outlines how employees and family members may elect continuation coverage. It also requires employers and plans to provide notice. Another amendment to ERISA is the Health Insurance Portability and Accountability Act (HIPAA), which provides rights and protections for participants and beneficiaries in group health plans. HIPAA includes protections for coverage under group health plans that limit exclusions for preexisting conditions; prohibit discrimination against employees and dependents based on their health status; and allow a special opportunity to enroll in a new plan to individuals in certain circumstances. HIPAA may also gives individuals the right to purchase individual coverage if they have no group health plan coverage available, and have exhausted COBRA or other continuation coverage. See Also: Health Insurance Portability and Account-
ability Act (HIPAA); Health Maintenance Organization (HMO). Bibliography. Melody A. Carlsen, “Will COBRA Begin
to Strike Employers Again?,” National Underwriter Property & Casualty-Risk & Benefits Management (March 30, 1992); Hinda R. Chaikind, et al., eds., The Health Insurance Portability and Accountability Act (HIPAA): Overview and Analyses (Novinka Books, 2004); United States Department of Labor, www.dol.gov. (cited October 2006). Ben Wynne, PH.D Gainesville State College
Endemic The term endemic should be defined according the context, an endemic plant or animal means that they are native or restricted to a specific geographic area. Whereas, in an epidemiological context it is defined as the continuous presence of a disease in a specific geographical area or population with relatively low to moderate level of prevalence and incidence compared to other areas or populations, without exhibiting extreme fluctuations over time. It may also indicate that the infection can persist in that area or population for a long period of time without the need of being reintroduced from an external source. The definition of hyperendemic is similar to that of endemic but the prevalence or incidence rates are persistently high. Endemic diseases are present all over the globe. Some are old diseases such as malaria and measles, and others are newly discovered such as HIV/AIDS or re-emerging (e.g. multidrug resistant tuberculosis). Although the historical roots of the term endemic was related mostly to communicable diseases, some noncommunicable diseases fall under the category of endemic disease. A good example of these is endemic goiter that occurs among populations of communities with iodine-depleted soil. Endemic diseases may lead to severe effects on populations and countries suffering from such diseases. The range of effects includes various aspects such as the economic and social aspects and is not limited to the medical aspects and human suffering. Malaria, for example, is an endemic disease in large areas of the African continent. In addition to 300 million acute cases taking place globally every year, resulting in more than a million deaths, of which 90 percent occur in Africa. The economic cost is estimated to be above $12 billion of lost Gross Domestic Product (GDP) of African countries. Another disease which is endemic in some African regions is HIV/AIDS which had devastating effects on the social fabric of some communities where the levels of HIV/AIDS related mortality was so high among adults leaving many children without parents to provide required care for them. This phenomenon was called the AIDS orphans. In 2005, it was estimated that the number of orphans because of AIDS in South Africa was 1,200,000, while in Zimbabwe 77
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percent of the number of orphans in the same year was because of AIDS. In the sub-Saharan Africa it is predicted that there will be 15.7 million AIDS orphans by the year 2010. The above-mentioned information testifies to the need for directing efforts toward controlling and preventing endemic diseases. The first step in that direction is to establish an efficient surveillance system that provides the needed information for monitoring the trends of disease occurrence including endemic diseases. This will give public health professionals information about the levels of endemic diseases and whether the endemicity is stable or fluctuating. It will also be helpful in detecting epidemics where the occurrence of a certain disease in a community or population group becomes clearly in excess of expected levels. A disease can be endemic in one place and epidemic in another. A classical example of that is smallpox in the early 17th century. While, smallpox was endemic among children in Europe, it caused a devastating epidemic in 1633 among indigenous Indians living at the Massachusetts Bay killing all the population in some plantations. With the recent advances in the fields of technology, communication and transport (traveling) the whole notion of endemic diseases should be readdressed. Infections and infectious agents do not know borders and can move quickly from one place to another. An infectious agent can arrive from a continent to another in a matter of hours. The recent bird’s flu and SARS epidemics are clear proofs of that fact. Some diseases such as HIV/AIDS became endemic in almost the entire globe. This shows the need for global cooperation in the field of disease control and prevention. SEE ALSO: Epidemiology; Epidemic. BIBLIOGRAPHY. AVERT, “AIDS Orphans” www.avert.org
(cited December, 2006); Centers for Disease Control and Prevention, “Protecting the Nation’s Health in an Era of Globalization: CDC’s Global Infectious Disease Strategy,” www.cdc.gov/globalidplan (cited December, 2006) Leon Gordis, Epidemiology (W.B. Saunders, 2004); John Last, A Dictionary of Epidemiology (Oxford University Press, 2000); Roll Back Malaria- World Health Organization, “Malaria in Africa,” www.rbm.who.int (cited December 2006). Abdullatif Husseini Birzeit University-Palestine
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Endocrine Diseases (General) Endocrine diseases are those that affect the human endocrine system which are the group of ductless glands used to regulate the human body processes by secreting chemical substances called hormones, which are then carried to a number of specific target organs and tissues by the bloodstream. The diseases or disorders result in too much hormone secretion or too little hormones being secreted, or from problems within the body which prevent the hormone to be used effectively. From the early 20th century, medical researchers have been involved in cataloging the various endocrine diseases and other disorders of the endocrine system. The first of these was disorders of the adrenal system. These include problems with adrenal insufficiency such as Addison’s disease, congenital adrenal hyperplasia (sometimes called adrenogenital syndrome), and mineralocorticoid deficiency. Other adrenal problems include Conn’s syndrome, Cushing’s syndrome, pheochromocytoma, and adrenalcortical carcinoma. Another range of problems with the endocrine system can be categorized as glucose homeostasis disorders, such as diabetes mellitus, and hypoglycemia, which include idiopathic hypoglycemia and insulinoma. Metabolic bone diseases include osteoporosis, osteitis deformans (sometimes called Paget’s disease of bone), and rickets and osteomalacia. There were also a large number of pituitary gland disorders such as diabetes insipidus, hypopituitarism (and panhypopituitarism), and pituitary tumors. The last includes pituitary adenomas, prolactinoma (and hyperprolactinoma), acromegaly, and Cushing’s disease. Other disorders include those affecting the parathyroid gland and the thyroid gland: hyperparathyroidism, pseudohyperparathyroidism primary hyperparathyroidism, secondary hyperparathyroidism, and tertiary hyperparathyroidism—some connected with Graves-Bassedow disease. The other endocrine diseases involve sex hormones, including disorders of sexual development, and intersex disorders, such as hermaphroditism, gonadal dysgensis, and androgen insensitivity syndromes; hypogonadism such as gonadotropin deficiency, Kallman syndrome, Klinefelter syndrome, ovarian failure, testicular failure, and Turner syndrome.
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The earliest evidence of medical practitioners becoming aware of the endocrine system was the Chinese, who, as early as 3000 b.c.e. started diagnosing some endocrinologic disorders and working out some effective treatments. One of the most obvious of these disorders was goiter which involved an enlargement of the thyroid gland, which rapidly becomes noticeable on sufferers. It was discovered that eating seaweed could help reduce the problem, but it was not until the 19th century that it was found that the cause was iodine deficiency and the cure was effective as seaweed was rich in iodine. The creation of eunuchs in the ancient world in Egypt, China, and elsewhere led to direct endocrinologic intervention, although this was not realized at the time. In Europe from the Middle Ages until as late as the 18th century, some boys were castrated to preserve their treble voices for singing in cathedral choirs. It was, curiously, the system of castration that led to some early surgeons to begin to study the endocrine system, even though it did not have that name at the time. A Scottish surgeon and anatomist, John Hunter, practicing in London, managed to successfully transplant the testis (testicle) of a rooster into the abdomen of a hen. His work was followed by that of French physiologist and neurologist Charles-Édouard BrownSéquard, who concluded that he believed the testicles contained a substance that had rejuvenation properties. In 1889, he injected himself with fluid from the testicles of freshly killed dogs and guinea pigs, to which he had added water. His work helped pioneer the studies of endocrinology, and hence helped others start work on describing, then diagnosing endocrine diseases. The work of the French physiologist Claude Bernard came up with the concept of humans—and, indeed, other living organisms—having what he described as the milieu intérieur (internal environment). This led to Walter Bradford Cannon, the American physiologist, using the homeostasis for the first time. SEE ALSO: Endocrinology. Bibliography. J. E. Griffin and S. R. Ojeda, Textbook of
Endocrine Physiology (Oxford University Press, 2000); V. C. Medvei, A History of Endocrinology (MTP Press, 1982). Justin Corfield Geelong Grammar School, Australia
Endocrinology Endocrinology is a branch of medicine that deals with the disorders of the endocrine system and also deals with specific secretions called hormones. This involves disorders such as diabetes mellitus, hyperthyroidism, and other similar problems. The origins of endocrinology come from the discovery that all multicellular organisms need to have a system to regulate and integrate the functioning of cells. To do this, especially in higher animals, the nervous system and the endocrine system are both used. For the latter, the body releases, usually into the blood, chemical agents that are essential for the proper development and function of organisms. This was first realized by some thinkers of the classical world such as the Greeks, Aristotle and Hippocrates, and the Romans, Lucretius, Celsus, and Galen. However, these tended to emphasize the influence of “humors,” and it was not until the 19th century that pathologists and others came up with a more detailed knowledge of the endocrine system. As a result, the branch of medicine known as endocrinology was developed whereby doctors and medical researchers deal with biosynthesis, storage, body chemistry, and the physiological function of hormones and with the cells of the endocrine glands and also tissues that secrete hormones into the glands. The development of research into endocrinology has seen researchers being involved in the diagnostic evaluation of a large number of symptoms and variations that occur between different people, and tabulate these to work out a long-term management of disorders which come from either a deficiency or an excess of a particular hormone. The most common field in which endocrinologists are involved is that of treating people with diabetes mellitus, first in diagnosing the presence of the disorder and then working out the most suitable way that people can manage it. An early French endocrinologist was Antoine Lacassagne who studied under Marie Curie, and worked heavily with radium. However, the study of it on a scientific level began with Arnold Adolph Berthold in the 1840s, and was developed by Charles Edouard BrownSéquard. The pioneer of endocrinology in the United States was Harvey Williams Cushing (eponym of Cushing’s syndrome) who was involved in the removal of a portion of the anterior lobe of the pituitary, being shown to be a successful way of treating acromegaly. In
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1916, P. E. Smith and Bennet Allen reported separately about the fact that pituitary surgery could result in a diminished growth rate and reduce the function of the thyroid gland. As interest in endocrinology mounted, it was decided to form what became the Endocrine Society. It was founded on June 4, 1917, as the Association for the Study of Internal Secretions. The certificate of incorporation was filed on January 13, 1918, and the society gained its present name on January 1, 1952. It has held annual meetings since 1916 (with the exception of 1943 and 1945), and has published Endocrinology since January 1917. It has also published the Journal of Clinical Endocrinology, which predates the society, having published its first issue in 1914. On January 1, 1952, it became The Journal of Clinical Endocrinology and Metabolism. There are currently between 7,000 and 8,000 endocrinologists in the United States, and these include Edwin B. Astwood who introduced the use of thiouracil in the treatment of thyrotoxicosis; Gerald Auerbach who isolated the parathyroid hormone; Paul Bell who elucidated the molecular weight of ACTH; Drs. A.H. Hersch and E. C. Kendall who treated rheumatoid arthritis with cortisone; and pioneers R. D. Evans, S. Hertz, A. Roberts, and J. G. Hamilton who worked with radioactive iodine. Other endocrinologists include Solomon A. Berson and Rosalyn S. Yalow who introduced the technique of radioimmunossay; Franciszek Kokot; Zvi Laron; Stafford Lightman; and Bernhard Zondek, a pioneer of reproductive endocrinology. Some recent endocrinologists have been involved in research that has massively helped other fields of medicine with Elwood V. Jensen, president of the Endocrine Society from 1980–81, winning the 1980 Charles F. Kettering Prize of the General Motors Cancer Foundation for his work on “discovering the steroid receptor protein present in certain mammary cancers and for developing a method for determining which breast cancers were hormonally sensitive and thereby responsive to endocrine therapy.” SEE ALSO: Endocrine Diseases (General). Bibliography. Endocrine Society, www.endo-society.
org; J. E. Griffin and S. R. Ojeda, Textbook of Endocrine Physiology (Oxford University Press, 2000); V. C. Medvei, A History of Endocrinology (MTP Press, 1982); J. D. Wilson, “Charles-Edouard Brown-Séquard and the Centennial
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of Endocrinology,” Journal of Clinical Endocrinology and Metabolism (v.71, 1984). Justin Corfield Geelong Grammar School, Australia
Engram Especially throughout the 20th century, philosophers, psychologists, and neurologists have tended to fiercely disagree about whether the brain and mind are modular and functions are localized (as in the caricature of 19th-century phrenologists) or whether it is more uniform and acts more globally, with its functions diffusely represented. One contested aspect of brain function is memory: When one has a new memory, what changes in the brain? Where does the memory “go” in the brain? The engram (or “trace”) is the putative particular brain locus for memories. Based on the failure of his own lesion studies to find any such entity, the American neuropsychologist Karl Lashley, in his famous 1950 essay, “In Search of the Engram,” sides against localization and concludes that the engram is represented broadly throughout the brain. One alternative explanation we may consider is that this difficulty in locating memories in the brain exists because memories are encoded in an immaterial mind and therefore would not alter the brain at all. This Cartesian dualistic notion is easily refuted by examples of patients who have changes in memory functioning by physical damage to their brains, or by the example of (physical) drugs that are given and subsequently alter the ability of a person to form or retrieve memories. Modern scientific methods have allowed a more nuanced position than the either/or of the Lashley era and the dualism pervasive since Descartes, or possibly even earlier via the 11th century Islamic philosopher Ibn Sina. In contrast, the 2000 Nobel Prize in Medicine was given partially to Eric Kandel for his work demonstrating the molecular mechanisms of memory storage at neuronal synapses. These basic learning mechanisms seem to, in fact, be conserved among all animals. Further evidence that memories are created, stored, and retrieved by the actions of functionally differentiated brain regions was provided
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by the increasing evidence from the neuropsychology clinic. The famous patient H. M. had his medial temporal lobes removed (most importantly, his hippocampus) and subsequently could no longer form new long-term declarative memories. Additional evidence has shown that procedural memories (e.g., learning how to throw a curveball) are created and stored in a manner separate from declarative memories (e.g., remembering a phone number). With the advance of modern cellular, molecular, and recombinant genetic methods of neurological research, the debate has somewhat resolved. Memory seems to have both definitive aspects of functional localization as well as diffuse representation: certain cortical and subcortical areas are absolutely crucial for nonpathological memory functioning, and yet many diffuse projections and interconnections exist between memory and other relevant brain regions. SEE ALSO: Memory; Neuroscience; Psychology. Bibliography. Darryl Bruce, “Fifty Years since Lashley’s
‘In Search of the Engram’: Refutations and Conjectures,” Journal of the History of the Neurosciences (v.10/3, 2001); A. Casadio, et al., “A Transient Neuron-Wide Form of CREBMediated Long-Term Facilitation Can Be Stabilized at Specific Synapses by Local Protein Synthesis,” Cell (v.99, 1999); Karl Lashley, “In Search of the Engram,” in Society of Experimental Biology Symposium No. 4: Physiological Mechanisms in Animal Behaviour (Cambridge University Press, 1950); W. B. Scoville and B. Milner, “Loss of Recent Memory after Bilateral Hippocampal Lesions,” Journal of Neurology, Neurosurgery and Psychiatry (v.20, 1957). Omar Sultan Haque Harvard Medical School
Environmental Health Environmental health is the subfield of public health that is concerned with assessing and controlling the impacts of people on their environment (including vegetation, other animals, and natural and historic landmarks) and the impacts of the environment on them. The environment is a vital tool that has been used by human beings for centuries. The environment
has provided food, shelter, and energy, but because of industrialization, technology has been drawing from and consuming more resources, causing adverse effects not only to the environment but also to people. Environmental pollution affects the people around it by contaminating the air and water with foreign material, causing widespread disease. Manmade chemicals used in the environment can infect the human body through inhaling pollutants in the air or drinking the one found in the water. Not only can the chemicals have long-standing effects on the individual exposed to them, but they can also have hereditary effects on the progeny of that person. Many herbicides have caused irreversible damage to the environment and the surrounding people (the most notable example of this is Agent Orange, which was developed by the United States and used in Vietnam). Every human being on the planet depends on the environment, so when it becomes contaminated, the environment has the potential to cause disease among people. Awareness of the effects people have on the environment is the most important factor in dealing with pollution because the best way to prevent the spread of disease through pollution is to eliminate its source. Herbicides are created to kill certain kinds of plants (mostly weeds) and are typically used by farmers. The chemicals in these herbicides are toxic to humans, so adequate warning is often provided when an area is to be sprayed to avoid human exposure to it. However, in some instances, a warning is not given. During the Vietnam War, the U.S. government developed an herbicide designed to destroy the foliage used by the Vietcong to hide the movement of their troops and set up ambushes. The herbicide was code named Agent Orange after the orange stripe on the barrels containing the herbicide. Although Agent Orange fulfilled its objective by destroying the plant life, the damage it caused has taken decades to recover from and will take many more. Furthermore, it has affected the soldiers and Vietnamese by causing several different health effects. People exposed to Agent Orange had a higher chance to contract liver problems, chances of cancer, and immune system disorders. Also, birth defects were more prevalent in children born from Vietnam veterans who were exposed to Agent Orange. Contamination of a water supply is dangerous because it spreads rapidly and affects every person
in the area. In 2005, residents of New Delhi, India, dealt with a cholera contamination in the water supply. A survey of water samples in 15 resettlement colonies and slums in the capital by Hazard Centre, a technical consultancy firm, revealed that 90 percent of those were contaminated. In the developing countries, the fact that human excreta often mix with drinking water supplies plays a central role in public health. Water quality is an important facet of the environment and must be a constant concern in the minds of humanity. Without taking the appropriate measures to cleanse water supplies, especially those used for drinking and bathing purposes, diseases such as cholera will continue to infect the world. In addition to its existence from sources such as human excreta, water pollution comes from waste water discharges from factories. Two plants located on the Xinqiang River, a drinking water source for central China’s Hunan Province, were accused of discharging waste water directly into the tributary; the arsenide content of the waste water was more than 1,000 times higher the national average. Air pollution shares the same dilemma as water pollution, because once started, the pollution spreads quickly and is almost impossible to contain. The Gansu Province of China had dealt with a severe lead poisoning incident. Residents of Xinsi and Mouba villages were poisoned by a lead smelting plant that continued to operate in summer 2006 after being told to cease production but has since been demolished. In an effort to eliminate air pollution, the U. S. Environmental Protection Agency banned the use of lead in gasoline. Lead poisoning affects children in a much harsher manner than adults. The chance of full recovery is lesser for children than for adults. Adults usually recover from mildly elevated levels, but children can suffer permanent impairment of their intelligence. People who survive severe toxic lead levels are likely to suffer some permanent brain damage. The health of the people is directly related to the health of the environment. Because pollution affects the air we needed to breathe and the water we needed to drink, people must be aware of the condition of the environment. It is because of this dependency on the environment that humanity must be conscious of environment’s status to prevent pollution before it starts. As long as people depend on the environment, its deteriorating condition due to
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the pollutants from automobiles and factories will continue to affect the health of the people. Even the herbicides created for agricultural or military means can cause people to be poisoned, the effects of which may be passed down to the progeny in the form of ailments and diseases. The environment provides many resources vital to people. However, in an effort to extract these resources the environment can become contaminated, which in turn contaminates the people. This cycle must end before the environment is completely destroyed and humanity is left with no more resources and widespread disease. See Also: Environmental Protection Agency (EPA); Lead
Poisoning; Pollution.
Bibliography. L. Hodges, Environmental Pollution
(Holt, Rinehart and Winston, 1977); L. Hui, “250 Kids Hospitalized in Gansu after Lead Poisoning,” news.xinhuanet. com/(cited December 6, 2006); N. Khanna, “Water Contamination: Cholera Cases on the Rise,” http://www.ndtv. com/ (cited December 6, 2006); D. W. Moeller, Environmental Health (Harvard University Press, 1992); L. Vancil, “Agent Orange,” www.vvvc.org cited October 16, 2006). DeMond Shondell Miller Joel C. Yelin Rowan University
Environmental Medicine A new biomedical science related to the study of short-, but also, long-term effects of environmental factors (physical, biological, and chemical) on human health. Although the concept and general application of environmental medicine is certainly older and well known, its vision was only focused to environmental health. In the past, this discipline, indeed, only dealt with solving of existing environmental problems at urban or rural ecosystems that could lead to problems in public health (e.g., contamination of rivers, lakes, wetlands, and other water sources). Currently, this concept is wider. Environmental medicine currently encompasses a plethora of preventive aspects, even considering the importance of the environmental health surveillance. This emergent discipline
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originated due to the growing number of links between environmental factors and human diseases. Environmental medicine is also called clinical ecology. Adverse effects of the environment on human health have become a major issue throughout the world during the last several decades. This issue is influenced not only by such events as Love Canal, Seveso, and Chernobyl, but also by recognition of the harmful effects of industrial emissions and, for example, worldwide waste problems. In most developed countries with established healthcare systems, environmental medicine has evolved as a special area with sources in the public health sector (environmental hygiene) and also in the individual care for patients with health problems linked to adverse environmental conditions. Currently, environmental medicine is closely related to different biomedical and environmental sciences such as public health, epidemiology, environmental epidemiology, toxicology, ecology, ecoepidemiology, ecogenetics, global health, tropical medicine, medical geography, medical geology, wilderness medicine, agricultural medicine biometeorology, medical demography, and occupational medicine, among others. A new important concept was introduced in this field few years ago: the concept of primary environmental care, related in its essence to the methodical principles of the primary healthcare, but in this case oriented to the environment, in which a person is interacting. Primary environmental care is a strategy of environmental action, basically preventive and participative at the local level, that recognizes the right of the human being to live in a healthy and proper environment and to be informed about the risks of the environment for the health, well-being and survival, but at the same time defining responsibilities and duties in regard to the protection, conservation, and recovery of the environment and the health. With this concept, it is important to add that environmental medicine is also related to public education about the interaction between humans and their environment, as well as to promote optimal health through prevention and effective treatment of the causes of illness. Other visions and concepts are currently in development; the model of environmental medicine is based on the growing appreciation that the human body is constantly coping with its dynamic environment by
means of a number of inherited, built-in, complexly interacting, and usually reversible biologic mechanisms and systems. These systems are designed to maintain overall homeostatic mechanisms among all biological mechanisms. Their ongoing adjustments are unique to the individual and change continually over time. In the terminology emerged from the environmental medicine science, adverse consequences that result when interactions among biological functions are compromised by external or internal stressors are called the environmentally triggered illnesses. The stressors may range from severe acute exposure to a single stressor, to cumulative relatively low-grade exposures to many stressors over time. The resultant dysfunction is dependent on the patient’s genetic makeup, his or her nutrition and health in general, the stressors, the degree of exposure to them, and the effects of seven fundamental biological governing principles: biochemical individuality, individual susceptibility, the total load, the level of adaptation, the bipolarity of responses, the spreading phenomenon, and the switch phenomenon. The environment could be considered in a broader sense today. The task of this science is related to the study of the health risks posed by contaminants and other factors at home, in the workplace, and in the ambient environment. Although incipient yet, some authors consider that this will also include the aerospace as an environment where a person could suffer diseases and generate conditions for human illnesses (which will be in relation to the aerospatial medicine). In the current scenario of global change, environmental medicine is today more important than yesterday; and jointly with occupational medicine, this new specialty is encouraged to be strategic rather than tactical to optimize its value in the core business of industry-related medical needs. Because employers, governments, and workers bear major costs, they have a strategic interest in outcomes. Strategic opportunities exist for reduction of the impact of occupational injury and disease; stewardship of the environment, product, and process; the reduction of nonoccupational healthcare costs; for having occupational and environmental health and safety follow best business practices and be prominent in the leadership of change; for optimizing human relations/labor policies and practices; and for meeting regulatory requirements. The strategic position of the specialty can be strengthened through discussion, dialogue and
vision development, role definition, establishment and use of performance indicators, improved career structures and training, and a proactive approach to qualify initiatives, research, marketing, and development of strategic alliances. In the study of environmental medicine, one of the oldest and more important disciplines contributing substantially to the knowledge of this science is the toxicology. Chemical compounds ubiquitous in our food, air, and water are now found in every person. The bioaccumulation of these compounds in some individuals can lead to a variety of metabolic and systemic dysfunctions, and in some cases outright disease states. The systems most affected by these xenobiotic compounds include the immune, neurological, and endocrine systems. Toxicity in these systems can lead to immune dysfunction, autoimmunity, asthma, allergies, cancers, cognitive deficit, mood changes, neurological illnesses, changes in libido, reproductive dysfunction, and glucose dysregulation. Chemicals and their effects on these systems should be reviewed inside the frame of environmental medicine. Additionally, a focus on therapeutic regimens to combat the toxic effects of these and other compounds need also to be considered. Chemicals known as solvents are part of a broad class of chemicals called volatile organic compounds. These compounds are used in a variety of settings, are ubiquitous, and off-gas readily into the atmosphere. As a result of their overuse, they can be found in detectable level in virtually all samples of both indoor and outdoor air. Certain of these compounds are detectable in adipose samples of all U.S. residents. Once in the body, they can lead to a variety of neurological, immunological, endocrinological, genitourinary, and hematopoietic problems. Some individuals also have metabolic defects that diminish the liver’s clearing capacity for these compounds. Supplementation may be of benefit to help clear these compounds from the body and to prevent adverse health effects. external contaminants Other important aspect that deserves to be studied in the field of environmental medicine is the problem with pesticides. Although the use of pesticides has doubled every 10 years since 1945, pest damage to crops is more prevalent now than it was then. Many pests are now
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pesticide resistant due to the ubiquitous presence of pesticides in our environment. Chlorinated pesticide residues are present in the air, soil, and water, with a concomitant presence in humans. Organophosphate and carbamate pesticides—the compounds comprising the bulk of current pesticide use—are carried around the globe on air currents. Municipalities, schools, churches, business offices, apartment buildings, grocery stores, and homeowners use pesticides on a regular basis. Pesticides are neurotoxins that can cause acute symptoms as well as chronic effects from repeated lowdose exposure. These compounds can also adversely affect the immune system, causing cell-mediated immune deficiency, allergy, and autoimmune states. Certain cancers are also associated with pesticide exposure. Multiple endocrine effects, which can alter reproduction and stress-handling capacity, can also be found. Limited testing is available to assess the toxic overload of these compounds, including serum pesticide levels and immune system parameters. Treatment for acute or chronic effects of these toxins includes avoidance, supplementation, and possibly cleansing. In spite of this, new contributions of recent medical advances have been introduced in the artillery of research tools for environmental medicine, particularly those related to geographical sciences and to molecular biology disciplines. A revolution in biology and medicine is taking place as a direct consequence of rapid developments in the field of molecular biology. The tremendous advances in our knowledge of basic molecular genetics and cell biology have opened the door for new methods of diagnosis, assessment of individual susceptibility to disease, and elucidation of the pathogenesis of disease. These advances will have a profound impact on the practice of occupational and environmental medicine. The core value guiding the work of physicians and health workers, including those in environmental and occupational epidemiology and medicine and injury prevention, is to protect the health of the public, especially its most vulnerable individuals. In these fields, we emphasize teaching the use of epidemiology, the core discipline of public health, as a tool for early detection and prevention of disease and injury, as well as an instrument for hypothesis testing. The classic core topics are toxic and physical exposures and their effects, and strategies for their prevention; emerging issues are child labor, mass violence, and democide. In environmental health,
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students need to be prepared for the reality that the most important and severe problems are often the most difficult to investigate, solve, and evaluate. The following are some recommendations for producing graduates who are effective in protecting communities from environmental hazards and risks: 1.) Teach the precautionary principle and its application; 2.) Evaluate programs for teaching environmental and occupational health, medicine, and epidemiology in schools of public health by their impact on the World Health Organization (WHO) (http://www.who.int/) health indicators and their impact on measures of ecosystem sustainability; 3.) Develop problem-oriented projects and give academic credit for projects with definable public health impact and redefine the role of the health officer as the chief resident for Schools of Public Health and Community Medicine; 4.) Teach the abuses of child labor and working conditions of women in the workplace and how to prevent the hazards and risks from the more common types of child work; 5.) Upgrade teaching of injury prevention and prevention of deaths from external causes; 6.) Teach students to recognize the insensitivity of epidemiology as a tool for early detection of true risk; 7.) Teach the importance of context in the use of tests of statistical significance; 8.) Teach the epidemiologic importance of short latency periods from high exposures as sentinel events for later group risk for cancer and stating the case for action; 9.) Protect students and colleagues who are whistle-blowers in environmental health from harassment and punishment; 10.) Develop curricula and workshops that promote the use of epidemiologic tools for preventing genocide, democide, and their precursors. Schools of Public Health and Community Medicine are at the interface between the resources of academic power and the major problems of community health. Implementing the above recommendations will strengthen academic investigation and impact. SEE ALSO: Environmental Health; Environmental Protec-
tion Agency (EPA); Environmental Toxicology; Epidemiology; Toxicology. Bibliography. Gordon Cook and Alimuddin Zulma,
Manson’s Tropical Diseases (Saunders, 2003); Walter J. Crinnion, “Environmental Medicine, Part One: The Human Burden of Environmental Toxins and Their Common Health Effects,” Alternative Medicine Review (v.5/1, 2000);
Walter J. Crinnion, “Environmental Medicine, Part Two: Health Effects of and Protection from Ubiquitous Airborne Solvent Exposure,” Alternative Medicine Review (v.5/2, 2000); Walter J. Crinnion, “Environmental Medicine, Part Three: Long-Term Effects of Chronic Low-Dose Mercury Exposure,” Alternative Medicine Review (v.5/3, 2000); Walter J. Crinnion, “Environmental Medicine, Part 4: Pesticides—Biologically Persistent and Ubiquitous Toxins,” Alternative Medicine Review (v.5/5, 2000); J. J. Krop, “Clinical Ecology and Its Role in Diagnosis of Chronic Diseases Caused by Environmental Pollution. Indoor Air Pollution as a Major Factor,” Folia Medica Cracoviensia (v.34/1–4, 1993); R. K. McLellan, “Clinical Ecology,” Journal of the American Medical Association (v.269/13, 1993); A. J. McMichael, et al., Climate Change and Human Health: Risks and Responses (WHO/WMO/UNEP, 2003). Alfonso J. Rodriguez-Morales, M.D., M.Sc. Universidad de Los Andes, Venezuela Carlos Franco-Paredes, M.D., M.P.H. Emory University
Environmental Protection Agency (EPA) The United States Environmental Protection Agency (EPA) is responsible for protecting the public health of Americans and for safeguarding the environment. EPA activities are frequently carried out in conjunction with state, local, and tribal governments. Major EPA efforts include guaranteeing that air is safe and healthy throughout the country; that drinking water is clean and safe to drink; that rivers, lakes, wetlands, aquifers, and coastal and ocean waters are protected; that foods are free of unsafe pesticide residues; and that wastes are stored, treated, and disposed of safely and in accordance with the natural environment. Furthermore, EPA is charged with reducing environmental risks from climate change, stratospheric ozone depletion, and other threats to a healthy global environment. EPA national headquarters is located in the Ariel Rios Building, 1200 Pennsylvania Avenue, NW, Washington, D.C. 20460. In addition to several other offices headquartered in the capital, the Environmental Science Center is located in Forte Meade, Maryland.
The EPA works to reduce environmental risks from climate change, and other threats to a healthy global environment.
General information on EPA may be accessed by telephone at (202) 272-0167 and through the 10 regional offices. Detailed information is available on the EPA Web site (http://www.epa.gov/), which also provides a listing for various telephone hot line numbers (http:// www.epa.gov/epahome/hotline.htm). EPA libraries distributed throughout the country have traditionally served as valuable resources for information on the environment and the agency; however, the future of these libraries is in jeopardy due to proposed cuts by the George W. Bush administration. The EPA was created in 1970 in response to rising concern about environmental issues. Today, the Agency employs around 18,000 individuals in various offices and laboratories. Over half of those employees are engineers, scientists, and policy analysts. Other professionals include specialists in legal matters, public affairs, financial planning, information management, and computer technology. The remaining employees make up the EPA’s support team. The EPA also maintains Research Triangle Park (RTP) in North Carolina where research is conducted on various pollutants and how humans react to them. Programs instituted under the Clean Air Act are encompassed in RTP, which also houses the EPA National Computer Center. Other EPA research facilities are located throughout the country, including Montgomery, Alabama; Denver, Colorado; Athens, Georgia; Las Vegas, Nevada; Narragansett, Rhode Island;
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Gulf Breeze, Florida; Duluth, Minnesota; Corvallis, Oregon; Cincinnati, Ohio; Ada, Oklahoma; Edison, New Jersey; and Ann Arbor, Michigan. The administrator of the EPA, who is appointed by the president of the United States, is responsible for leading the agency in fulfilling its mission. The following EPA offices make up the Office of the Administrator: Administrative Law Judges, Children’s Health Protection, Civil Rights, Congressional and Intergovernmental Relations, Cooperative Environmental Management, the Environmental Appeals Board, Environmental Education, the Executive Secretariat, Executive Services, Homeland Security, Policy Economics, and Innovation, Public Affairs, the Science Advisory Board, and Small and Disadvantaged Business Utilization. Other offices that answer to the administrator include the Office of Administration and Resources Management, which is responsible for managing EPA’s human, financial, and physical resources; the Office of Air and Radiation, which carries out air and radiation protection activities; American Indian Environmental Office, which works with tribal leaders to enhance environmental efforts among the native population; the chief financial officer, who has the responsibility for managing and coordinating budget, analysis, and accountability within EPA; the Office of Enforcement and Compliance Assurance, which focuses on community pollution prevention; the Office of Environmental Justice, which protects predominately minority communities and low-income populations; and the Office of Environmental Information, which focuses on innovative ways to use information to promote EPA mission. Additional offices that come under the direction of the administrator are the History Office, which archives materials and provides relevant information to the public; the Office of General Counsel, which houses the EPA legal team; the Office of Inspector General, which audits and investigates EPA programs; the Office of International Affairs, which serves as a liaison between the United States and the international community; the Office of Prevention, Pesticides, and Toxic Substances, which is responsible for the control of toxins and alerting the public about potential risks; the Office of Waste and Emergency Response, which oversees waste management and disposal and manages the Superfund Program created to fund cleanup
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of toxic waste sites; and the Office of Water, which regulates the quality of drinking water and provides oversight for all other water sources. The deputy administrator chairs the Science Policy Council, which liaises with the media, other federal programs, and researchers involved in cross-disciplinary issues that affect environmental policy. The EPA’s strategic goals include promoting clean air and global climate change, ensuring that water remains clean and safe, land preservation and restoration, producing healthy communities and ecosystems, and improving compliance and environmental stewardship. The EPA’s research activities are carried out under the Office of Research and Development, which partners with academicians involved in environmental research through research grants and fellowships. These research programs focus on a variety of topics crucial to a healthy environment. The Environmental Monitoring and Assessment Program (EMAP) monitors and analyzes trends in ecological research. The Lake Michigan Mass Balance Study, carried out through the Great Lakes National Program Office, involves the study of toxic chemicals found in Lake Michigan and records observations of how those toxins interact with the large-scale ecosystem of the lake. The EPA is also involved in the research of such agencies as the Human Exposure Research Division of the National Exposure Research Laboratory, the National Center for Environmental Assessment, the National Center for Environmental Economics, the National Center for Environmental Research, the National Environmental Scientific Computing Center, and the Office of Science and Technology of the Office of Water. See Also: Drinking Water; Pollution. Bibliography. Mark Allen Eisner, Governing the Envi-
ronment: The Transformation of Environmental Regulation (Lynne Rienner, 2007); Environmental Protection Agency, www.epa.gov; Major Management Challenges and Risk: Environmental Protection Agency (Government Accounting Office, 2003); Brent M. Haglund and Thomas Still, Hands-On Environmentalism (Encounter, 2005); Daniel E. Harmon, The Environmental Protection Agency (Chelsea House, 2002); Kenneth J. Meier and Laurence J. O’Toole Jr., Bureaucracy in a Democratic State: A Government Perspective (Johns Hopkins University Press, 2006); Robert Repet-
to, ed., Punctuated Equilibrium and the Dynamics of U.S. Environmental Policy (Yale University Press, 2006); Dennis D. Riley, et al., Bureaucracy and the Policy Process: Keeping the Promises (Rowman & Littlefield, 2006). Elizabeth R. Purdy, Ph.D. Independent Scholar
Environmental Tobacco Smoke Environmental tobacco smoke (ETS, also known as secondhand smoke or involuntary or passive smoking) is a worldwide phenomenon affecting people in all countries and communities. It has been linked to multiple health effects in both children and adults. Policies requiring smoke-free environments are the most effective measure of decreasing ETS exposure. ETS is a mixture of the smoke released from the burning end of a cigarette, pipe, or cigar (sidestream smoke) and the smoke exhaled by smokers (mainstream smoke). It contains over 4,000 chemicals, of which over 40 substances are known to be cancer causing (carcinogenic). In 1992, the U. S. Environmental Protection Agency (EPA) classified ETS as a group A carcinogen, based on evidence linking it as the cause of over 3,000 lung cancer deaths in humans each year. According to a report by the U. S. Department of Health and Human Services in 2006, more than 126 million nonsmoking Americans are exposed to secondhand smoke in their daily lives, both at home and work. Children are even more exposed to passive smoking than adults. Nearly 30 percent of U. S. children in the age group 3–11 years are exposed to ETS. About 25 percent of children live with at least one smoker, in contrast to only about 7 percent of nonsmoking adults. Although there has been a decline in the exposure to ETS in the United States over time, passive smoking continues to be a common and preventable public health hazard worldwide. There are several significant short-term effects of exposure to ETS. Tobacco smoke is a known allergen, causing exacerbation of symptoms in both allergy sufferers and asthmatics. Even in those without any known allergies, compared to when breathing smoke-free air, nonsmokers may experience multiple
symptoms in the presence of smoke, such as cough, headache, nausea, and fatigue. Even though these short-term effects terminate immediately after exposure, repeated exposure is believed to cause many significant long-term effects. There is comprehensive scientific evidence linking ETS to multiple long-term health effects in both adults and children. Nonsmokers who live with a smoker increase their risk of developing lung cancer by 20 to 30 percent. In addition, through the exposure of ETS in the workplace, a nonsmoker has a 16 to 19 percent increased risk of developing lung cancer. Secondhand smoke reduces the lung function of nonsmokers and causes irritation to the lining of the lungs, leading to coughing, excess phlegm, and chest discomfort. It can also irritate the eye, nose, and throat. In addition, daily exposure to ETS increases the risk of developing heart disease by 25 to 30 percent in nonsmokers. With their developing lungs, higher breathing rates than adults, and lack of control over their indoor environments, children are particularly vulnerable to the effects of secondhand smoke. Children exposed to ETS are at an increased risk for sudden infant death syndrome (SIDS), acute respiratory infections, ear problems, and more severe asthma. Newborns, whose mother smoked while pregnant or who were exposed to secondhand smoke after birth, develop weaker lungs than unexposed infants. According to EPA reports, in children younger than 18 months, ETS exposure causes between 150,000 and 300,000 lower respiratory tract infections (including pneumonia and bronchitis), leading to 7,500 to 15,000 hospitalizations each year. Passive smoking also causes a buildup of fluid in the middle ear of the exposed child, resulting in numerous middle ear infections. Asthmatic children who are exposed to secondhand smoke are especially at risk. The EPA estimates that the number, severity, and frequency of asthma exacerbations increases significantly with exposure, affecting between 200,000 to 1 million children annually. In nonasthmatic children exposed to ETS, there is an increased risk of developing lung disease. As a result of the clear scientific evidence of the effect of ETS on nonsmokers, in 2003, the World Health Organization (WHO) passed a resolution encouraging all countries to implement smoke-free policies in workplaces and indoor public buildings. The WHO recognizes that every person has the right
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to breathe air free of tobacco smoke. Several studies have indicated that there is no risk-free level of exposure to secondhand smoke. Completely eliminating smoking in indoor areas has been shown to fully protect nonsmokers from exposure to ETS. Simply separating smokers from nonsmokers, cleaning the air, or ventilating buildings cannot effectively eradicate the effects of passive smoking. As such, several countries (including Sweden and Ireland) and many parts of the United States (including the states of Florida, California, Ohio, and New York) have passed smoking bans, regulating smoking in public areas. Even though it is largely disputed by the hospitality industry, these bans have not been shown to have an impact on restaurant or bar revenues. There have been several disputes from the tobacco industry criticizing the validity of the research showing a link between ETS and health effects. However, a review of this research found that the only factor affecting the results was the presence of funding from the tobacco industry. SEE ALSO: Environmental Toxicology; Smokeless Tobac-
co; Smoking and Youth; Smoking Cessation.
California Environmental Protection Agency’s Office of Environmental Health Hazard Assessment, “Health Effects of Exposure to Environmental Tobacco Smoke,” www.oehha.ca.gov (cited February 2007); U. S. Department of Health and Human Services, “The Health Consequences of Involuntary Exposure to Tobacco Smoke: A Report of the Surgeon General,” www.cdc.gov/tobacco/ sgr (cited February 2007). Bibliography.
Shannon Gearhart, M.D. Indiana University School of Medicine
Environmental Toxicology Environmental toxicology refers to the poisoning of the environment either accidentally or deliberately, leading to the term ecotoxicology being coined by R. Truhart in 1969. The idea of poisoning an environment dates back to the ancient world with the muchhighlighted story of the Romans sowing salt over the fields of their defeated enemy Carthage following
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the destruction of that city in 146 b.c.e. The salinity was to ensure that no crops would grow there, but historians now doubt that the Romans would have done this, owing to the vast cost of salt in the ancient world and the fact that Carthage was refounded as a Roman city soon afterward. However, there remains the possibility that the Romans might have used seawater to destroy some of the fertile fields around Carthage. Biological warfare has been considered early during the 20th century; however, the concept goes back to medieval and early modern times when there were attempts to pass the bubonic plague to enemies, especially in Renaissance Italy. There were also instances of the poisoning of waterholes by American and Australian settlers to kill indigenous people in their respective countries. The destruction of their food supplies, such as the killing of the vast bison herds which provided much food for the Native Americans, and the kangaroos in the case of the Australian aboriginals, are further examples of environmental destruction. During the Vietnam War, the use of Agent Orange and other defoliants with the specific aim of destroying rainforests where Vietcong guerrillas were hiding, is the most widespread recent use of poisons to deliberately destroy entire ecosystems. However, the concept of environmental toxicology in the modern era largely came from Silent Spring by Rachel Carson. The book was published in 1962 despite attempts by pesticide companies to prevent its publication. Carson highlighted the accidental side effects from the use of toxins, especially DDT, and fertilizers, which were used by farmers and had the result of killing large amounts of wildlife. She concentrated on researching the side effects from these, which some felt might have led to higher levels of cancer in humans. First alerted to the threat of DDT by a bird sanctuary in Massachusetts whose wildlife had been killed by DDT from an aerial spraying of crops nearby, Carson was able to show that pollutants used in one area could quickly affect another neighboring area, and the destruction of a particular part of the food chain upsets the “balance of nature” and can quickly lead to the destruction of an ecosystem. Chemical companies felt that Carson’s work unfairly attacked their products and a few tried to pressure the publisher to stop the book coming out. Since Carson’s book, work by people such as Dr. R. Truhart led to the establishment of the field of eco-
toxicology which has been defined as the branch of toxicology which is concerned with the study of the toxic effects, caused either by natural or synthetic pollutants, to the constituents of ecosystems, animals and humans, vegetables and microbial life. This has focused attention on industrial pollution and discharge from the mines, both deliberate and accidental. The result has been seen near many gold mines where there has been widespread use of cyanide, which has led to the poisoning of the environment, including the water table. The effects have become noticeable around some mines such as those at Kalgoorlie in Western Australia. There had also been much pollution at the Panguna Copper Mine in Bougainville, leading to the local people, including some workers at the plant, to stage a revolt and eventually take control of the island to close down the mine. Environmental toxicology has also came about from accidents, the largest of which were clearly during the nuclear accident at Chernobyl and the chemical gas poisoning from the Union Carbide factory at Bhopal, the former resulting in a very high level of cancer in Ukraine and also neighboring areas, with large parts of the agricultural heart of the former Soviet Union being made uninhabitable; and the latter in the deaths of about 3,000 people on the night of December 3, 1984, and with injuries sustained by as many as 50,000 more. There have also been other accidents that have poisoned entire ecosystems such as the running aground of the Exxon Valdez on Prince William Sound, Gulf of Alaska, on March 24, 1989, and accidents by many other oil tankers which have resulted in massive oil slicks killing fauna and flora, and contaminating the shoreline. This also took place following the deliberate discharge of oil into the Persian Gulf by Iraqis in Kuwait just prior to the start of fighting between the United States and the Iraqis in the Gulf War of 1991. Other environmental toxicology has come from the dumping, deliberately or accidentally, of medical and nuclear waste around the world. SEE ALSO: Environmental Health; Environmental Medi-
cine; Environmental Protection Agency (EPA).
Bibliography. Rachel Carson, Silent Spring (Houghton
Mifflin, 1962); Inge F. Goldstein and Martin Goldstein, How Much Risk? A Guide to Understanding Environmental
Epidemic
Health Hazards (Oxford University Press, 2001); Lester B. Love, Toxic Chemicals, Health and the Environment (Johns Hopkins University Press, 1987). Justin Corfield Geelong Grammar School, Australia
Enzyme-Linked Immunosorbent Assay (ELISA) Enzyme-linked immunosorbent assay (ELISA) is a biochemical procedure that is used in scientific research and as a clinical tool. The basis of this technique is the ability of antibodies to bind specifically to their cognate antigens. ELISA is quite sensitive and specific, as well as relatively inexpensive, and therefore, is useful as a preliminary diagnostic tool. It is widely utilized in human immunodeficiency virus (HIV) testing and similar applications. During ELISA, an antibody is mixed with the antigen it recognizes, creating antibody–antigen complexes. A second antibody is then added that binds to these complexes—via either the antigen or the antibody component. This second antibody is coupled to an enzyme. When the enzyme’s substrate (the substance it modifies) is added, the enzyme will convert it into a light-releasing product. The result of the ELISA is that the presence of the original antigen–antibody complexes is detected as a fluorescent signal. ELISA is utilized to evaluate the presence of an antigen in a sample, or conversely, to detect the presence of an antibody. In the first case, an antibody specific for the antigen is used to coat a surface, and sample possibly containing the antigen is added. In the second case, the surface is coated with the antigen and the sample to be tested for the presence of antibody is added. In either scenario, an enzyme-linked secondary antibody is then used to detect the formation of antigen–antibody complexes. Use of ELISA in HIV Testing The first step in HIV testing is usually an ELISA. When an individual becomes infected with HIV, the immune system will attack the virus and produce antibodies specific for viral components. Rather than testing directly for HIV proteins, the ELISA tests for
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these anti-HIV antibodies. The assay is performed as follows: first, HIV viral proteins are coated on a surface (usually a plastic 96-well plate). Then, serum from a patient is added to the well. Excess serum is washed away and a second, enzyme-linked antibody is added that recognizes the anti-HIV antibodies. Excess antibody is washed away, and the enzyme’s substrate is added. If this results in a sufficiently strong fluorescent signal, the person is most likely infected with HIV. If there is little or no signal, the individual does not have anti-HIV antibodies. Caveats of ELISA According to the U.S. National Institute of Allergy and Infectious Diseases (NIAID), ELISA is reliable nearly 99.9 percent of the time. However, this means that the assay will give an incorrect result—either false-positive or false-negative—for approximately 1 in every 1,000 individuals tested. False-positives occur when an individual is not infected with HIV but his or her serum contains antibodies that cross-react with components of the HIV antigen mixture. False-negatives usually occur when an individual becomes infected with HIV a short time before the test, and his or her immune system has not yet produced antibodies against HIV. Because of the shortcomings of ELISAs, it is important to be tested periodically and to confirm positive results by ELISA retesting and by performing more specific and reliable assays such as a Western blot or polymerase chain reaction (PCR). SEE ALSO: AIDS; Immune System and Disorders; Immu-
nology; Polymerase Chain Reaction (PCR).
Bibliography. U.S. National Institute of Allergy and Infec-
tious Diseases, “Tests for HIV Infection,” http://www.niaid. nih.gov/dir/labs/lir/hiv/packet1.htm (cited March 1999). Kevin Shenderov New York University
Epidemic A sudden and great increase of new disease cases in a given human population from a common source. This can also understood as an increase in incidence
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of a disease in a given population. Incidence is the number of new disease cases or patients found or diagnosed over a given period of time. The Greek translation is understood as: epi- “upon” and demos or people. The rise in new cases with the disease is faster than what is to be expected in that given population from what is currently known about the disease and about the population. If the outbreak of disease affects the whole world it is refereed to as a pandemic: pan- all and demos- people. This is an important concept in global health as epidemics have decimated populations with malaria, tuberculosis, and many other communicable diseases. In a globalizing world, epidemics spread fast and efficiently from country to country and region to region devastating populations and quality of life. An outbreak refers to an increase in disease quickly to a small village or town whereas epidemic is an increase in disease for a specific region in the world or nation. Epidemics involve infectious disease and are detrimental to the communities they affect. Epidemics affect the health and well-being of millions throughout the developing world each year and many are preventable disease that can be avoided with simple measures such as vaccines, hygiene education, and public awareness. Types of Epidemics Epidemics are classified based on origin and pattern of transmission of disease. Epidemics can involve a single exposure to a disease or pathogen, multiple, or continuous exposures to disease causing agents. The disease involved in an epidemic can be transmitted by a vector (disease carrying agent) like a rat that carries bubonic plague, from person to person transmission (lack of hand washing or cramped living conditions), or from a common source such as contaminated water or food source. For example, a common water supply with cholera caused an epidemic in London in the middle of the 19th century. Many London citizens had uncontrollable diarrhea and other symptoms that used this water source. However, concluding the water source as the main point of transmission of disease was not so easy. To combat this epidemic, a large-scale epidemiological study was performed by a medical pioneer in this field, Dr. John Snow. His systematic methods used to study outbreaks and epidemics are the basis for epidemiological study used today.
Epidemics such as influenza, cholera (mentioned above), malaria, tuberculosis and most recently avian influenza virus, or bird flu, have inflicted millions across the globe. These diseases are preventable and their infection rate increases in the developing world with too few treatment measures. It is important to realize that not just the region or area that has the epidemic is affected—the whole world population feels ripple effects of these epidemics in a myriad of ways. These recent epidemics are able to move quickly transmitting from person to person in smaller communities and then moving across the globe passing socioeconomic barriers and inadequate treatment measures. For example, the affects of HIV/AIDS has graduated from epidemic to pandemic as new cases are growing and no population or community are immune. Indeed, everyone is negatively affected across the globe with this pandemic—medically, socially, economically, living standards, and in many other unforeseeable ways— HIV/AIDS affects everyone. However, the regions hardest hit with HIV/AIDS are sub-Saharan Africa, central Asia, and Latin America. Epidemics can spread and become pandemics as seen with HIV/AIDS. However, epidemics are usually contained to a specific community or geographical region as the incidence rises over time. For example, the bubonic plague or “Black Death” swept across the European continent by rats and more patients were getting the disease than any one city or area could adequately deal with—causing more disease to spread. This concept is arguably more recently observed with how bird flu has traveled across the globe on a much smaller scale inflicting less people but with lethality. The concept of globalization and easy connection of many people through trade, travel and the effects of war (forced migration and displacement), common markets, and mass transportation further enable transmission of disease across regions. This is epidemic in the 21st century. Sudden and major environmental changes can easily give rise to epidemics where populations are not suited to deal with such change and are resource poor (i.e., developing nations such as sub-Saharan Africa, the Middle East, Asia, and South America). One such example is malaria. There have been many spikes of malaria throughout the world in recent history and most centralized in Africa in the second half of the 20th century.
The Malaria epidemic Malaria has affected millions throughout human history. Prevention and treatment of malaria are readily known and not readily available to those regions that need it most. Various factors have prevented the public health community from eradicating the disease altogether. Environmental changes in weather and climate, irrigation and man-made standing waters where mosquitoes may breed, and people living in closer proximity to one another all enable the disease to infect many populations fast and efficiently. Furthermore, evolutionary changes in the malaria microbe and in mosquitoes, malarias vector, and human behavior toward the disease have all contributed to the durability of this epidemic. Malaria is a tropical parasitic disease that infects between 300 to 500 million people and kills nearly 3 million people annually. Furthermore, there has been an increase in multidrug-resistant parasitic strains that conventional medicine cannot treat. As a disease, malaria is transmitted through a mosquito bite that carries the parasite. If the disease is quickly diagnosed and properly treated, malaria is curable. Most countries that have the largest risk to contract malaria lack the resource to quickly diagnose or treat it—hence, the ongoing epidemic with a preventable and treatable disease. Epidemic and Epidemiology Epidemiology is the study of disease across populations and tries to conclude on disease as it will affect many people. This is different than clinical medicine where the individual is the focus of study and not a population or community. An epidemic affects populations and communities with disease and oftentimes an epidemiologist aids in the investigation and work to curb the spreading disease—like Dr. John Snow mentioned above in this entry. The epidemiologist will study the disease by looking at the physical and social environments where disease occurs. For example, malaria in Africa and government resource to combat epidemics and the lack of access the given country may have to disease prevention, quick diagnosis and effective treatment. Epidemiology involves all of this study material. Many doctors, nurses, and public health workers across the globe apply epidemiologic principles to better understand and prevent epidemics. The Centers for
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Disease Control and Prevention (CDC) is a U.S. federally funded agency that attacks epidemics globally. The CDC, based in Atlanta, Georgia, currently monitors the world for emergence of disease and epidemics. The CDC looks for health risks and promotes the prevention and treatment of global health risks and epidemics. Currently, the CDC is working with many other governments to curb epidemics and prevent further illness. Epidemics will never be eradicated from the health experience, but they can be caught quickly, treated, and prevented from future human suffering. SEE ALSO: AIDS; Bird Flu; Centers for Disease Control
and Prevention (CDC); Cholera; Endemic; Epidemiologist; Epidemiology; Incidence; Malaria; Malariology.
Bibliography. Rob Desalle, Epidemic! The World of Infectious Disease, (Norton, 1999); K. Kemm, Roger Bate and Lorraine Mooney, eds., Malaria and the DDT Story–Third World Problems–First World Preoccupations, Chapter 1 (Butterworth Heinemann, 1999); Sheldon Watts, Epidemics and History: Disease, Power, and Imperialism (Yale University Press, 1999).
John Michael Quinn V, M.P.H. University of Illinois at Chicago
Epidemiologist An epidemiologist is someone who studies diseases in populations in order to attribute factors that may be associated with a specific disease or a set of diseases with the end goal of finding methods of prevention and/or harm reduction. Epidemiologists may collect and analyze data attributed to an outcome of interest or use previously collected data, such as hospital records, in order to achieve their goals. Epidemiologists also play an instrumental role in designing observational and experimental studies involving human beings. One of the most cited pioneers in the field of epidemiology was an English physician in the 1850s named John Snow. During his time, the overall belief among the medical community was that cholera was transmitted through miasma, a concept that was usually described as “bad humors.” During a cholera epidemic in London in 1853, he observed that cases tended to
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Epidemiology losophy (PhD). The most common places to employ epidemiologists are governmental health departments, academic and research institutions, as well as private corporations such as pharmaceutical companies. SEE ALSO: Epidemiology. Bibliography. Dana Asher, Epidemiologists: Life Track-
ing Deadly Diseases (Rosen Publishing Group, 2003); Viet Thanh Nguyen, et al., Cholera, Chloroform, and the Science of Medicine: A Life of John Snow (Oxford University Press, 2003). Epidemics such as influenza, cholera, malaria, tuberculosis have inflicted millions across the globe.
be clustered. He eventually recorded cases on a map and concluded that most cases of cholera had used the same water pump on Broad Street as their main water source. In a somewhat maverick approach, he removed the pump’s handle and observed an overall reduction in the number of new cases of cholera. His findings were first rejected by the medical community but eventually received recognition for his findings. Some other famous epidemiologists are Richard Doll, Austin Hill, Robert Frost, and Jonathan Lister. Dr. Doll and Dr. Hill were instrumental in linking the dangers of cigarette smoking and risks for lung cancer. Dr. Frost was well known for his work in tuberculosis as well as founding the first epidemiology program in the United States. Dr. Lister is renowned both for his work with infection transmission and control as well as for Listerine®, the antiseptic mouthwash. In more recent times, individuals who have aided in the evolution and education of the field include Leon Gordis, Kenneth Rothman, Sander Greenland, Robert Elston, James Robins, and David Kleinbaum. Epidemiology began as a specialty within the medical profession, but epidemiologists are now trained independently of medical training in postgraduate programs, either in schools of public health or schools of medicine. The most common degrees awarded to individuals who wish to train in epidemiologic theory and practices are a master’s of science or master’s of health sciences (MS, MHS), master’s in public health (MPH), a doctor of public health (DrPH), and a doctor of phi-
Jose S. Lozada Case Western Reserve University
Epidemiology In the strictest sense, epidemiology is the study of epidemics. However, a broader definition is accepted today—epidemiology is the branch of medicine that specializes in studying the causes of disease, its distribution, and ways of controlling its spread in populations. Following its origins in the early 1800s, epidemiology has evolved through distinctive eras. These are characterized by its initial focus on sanitary conditions, then infectious diseases, and after World War II, heightened focus on chronic diseases. Epidemiological research has traditionally been quantitative and concerned with the incidence and prevalence of disease. Epidemiology has been criticized for focusing too narrowly on individual-level risk factors at the expense of political, economic, and social factors that underlie patterns of morbidity and mortality. The discipline may be entering a new era, characterized by multilevel research projects which incorporate molecular, individual, and societal levels of analysis. The Development of Epidemiology The work of John Snow in 1854 shaped the development of epidemiology. Working to understand an outbreak of cholera in the Soho district of London, Snow mapped the geographical location of victims and investigated what they may have had in common. One factor was that they were drinking water that originated in a common and contaminated pump. Snow
Epidemiology
closed the pump and was able to contribute toward stopping the epidemic. Importantly, he achieved this without knowledge of the bacterial mechanisms underlying the disease, and his methods influenced subsequent epidemiological research. This marked the first era of epidemiology, wherein sanitary conditions were the primary focus of research. This was followed by an infectious disease era (late 19th century to mid20th century) and the development of germ theory. After World War II and coinciding with the growing prevalence of chronic diseases, epidemiological research increasingly focused on individual-level risk factors and “healthy lifestyles.” This era was marked by an increasing acceptance of a “web of causality” model, in which no single causal agent would be expected to explain patterns of disease. In contrast, epidemiological research often operated within a “black box” paradigm, where associations could be theorized and investigated as causal without an understanding of biological mechanisms. This was a strength of epidemiology, for it could expand its research into areas not yet studied by other branches of science. However, it was also an important weakness, and criticisms have been made that associations without plausible underlying biological mechanisms do little to advance knowledge of public health concerns and may lead to false-positive (spurious) findings. The Tools of Epidemiology In practice, epidemiology is a very diverse field, and it is practiced by social scientists, physicians, demographers, biologists, and a wide range of other specialists in both the social and natural sciences. The central concept in epidemiology is a case, which can denote an episode of a disorder or illness, or an event, such as death. Epidemiologists study rates of incidence, or the number of new cases during a specific period of time, as well as rates of prevalence, or the total number of cases in a given period of time. Prevalence is often reported as a measure of point prevalence (at a specific point in time, such as a day), period prevalence (during a specific period of time, such as a year), and lifetime prevalence (reflecting the number of people expected to have a particular disorder at least once in their lifetime). Central to the work of epidemiologists is also the notion of a rate. This can be a crude rate, reflecting the number of cases per population, for example, infant mortality per 1,000 live births. Adjusted
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rates are also used to examine the effects of specific variables or social characteristics, for example, ageadjusted mortality rates. The Critique of Epidemiology A focus on identifying individual-level risk factors has led to a criticism of epidemiology for neglecting the political, economic, and social factors that underlie patterns of disease. For example, the growing literature on the social determinants of health suggests that in order to better understand the fundamental causes of disease, researchers need to expand their theoretical models of causality to not only include individual-level risk factors, but also include large-scale social factors such as income inequality. An even more radical critique has developed from political economy, which suggests that researchers need to examine a society’s system of commodity production and distribution. From this perspective, health, like income inequality, is a consequence of macroeconomic forces governed by the structure of the economic system. Challenges and Opportunities A key challenge for epidemiology is to sustain a sense of coherence in light of increasing specialization; indeed, in recent decades, myriad branches of the discipline have developed, including pharmacoepidemiology, social epidemiology, genetic epidemiology, and molecular epidemiology. A successful integration of these subdisciplines, and awareness that, increasingly, health issues are global issues, may signal a new paradigm, which Mervyn Susser and Ezra Susser have labeled “eco-epidemiology.” This era would be characterized by a multilevel approach to the study of disease, wherein advances at the molecular, individual, and societal levels of study would be integrated. SEE ALSO: Disease and Poverty; Epidemiologist; Medical
Geography.
Bibliography. Nancy Krieger, ed., Embodying Inequality: Epidemiologic Perspectives (Baywood, 2005); Mervyn Susser and Ezra Susser, “Choosing a Future for Epidemiology: I. Eras and Paradigms,” American Journal of Public Health (v.86/5, 1996).
Fernando De Maio, Ph.D. Simon Fraser University
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Epigenetics
Epigenetics The DNA in cells carries the blueprints, or genes, that code for the proteins necessary for cellular structure and function via the processes of transcription and translation. The double-stranded DNA is divided into several large, discrete components within the cell called chromosomes, and distinct chromosomes carry specific genes. An entire set of chromosomes is called a genome. Epigenetics refers to the study of changes in the genome of an organism that do not alter the actual sequence of nucleotides in that organism’s DNA, but do modify the DNA structure in other ways, by adding other chemical groups or by binding regulatory proteins to the DNA backbone. An epigenetic change affects the phenotype, the appearance, physiological functioning, or physical construction of that organism, rather than the genotype, the actual DNA sequence of the gene, the genes found on each chromosome, and the number of chromosomes. Thus, epigenetic changes are distinct from genetic mutations, which alter the DNA sequence of nucleotides. Despite not affecting the gene itself, epigenetic changes are heritable, meaning that they can be passed on from one cellular generation to the next as cells divide and replicate. Furthermore, although it was previously believed that epigenetic changes could not be passed from one organism to another via the sexual reproduction of multicellular organisms, new evidence indicates that epigenetic changes to gametes, or sexual reproduction cells, can also remain stable from one generation to the next. Epigenetic changes are less permanent than alterations to the genetic code, however, and can often be reversed, thus allowing cells more flexibility in adapting to environmental conditions than genetic mutations alone would allow. There are many cellular processes that lead to epigenetic changes. Some of these involve differential gene expression at the cellular level. One of these is differential ribonucleic acid (RNA) splicing, whereby the nascent messenger RNA (mRNA) transcript coded from the same gene in two different types of cells is patched together differentially to lead to two different types of protein products. Another involves the preferential transcription of certain genes in certain cells via the use of transcription factors, molecular ‘tags’ that encourage RNA polymerase to copy some genes more often than others. ‘Maternal effect’ epigenetic changes
can occur during fetal gestation, as the embryo inherits RNA and transcription factors from the maternal oocyte during the process of fertilization. Unlike genetic mutations, however, epigenetic changes do not generally affect the sequencing of the amino acids that make up the normal protein found in a specific cell. Gene expression is also controlled at the chromatin level, and other epigenetic processes alter the physical structure (although not the nucleotide sequence) of DNA such that some genes are more readily transcribed and translated than others. Histone modification, the process of altering the proteins that bind and compact strands of DNA chromatin into chromosomes, can alter gene expression. Methylation of histone proteins will inactivate a gene, while acetylation of histones will make a gene more readily available to the cellular machinery that transcribes DNA. In human females, one copy of the X chromosome is often randomly inactivated via methylation. Epigenetics changes are important in somatic cellular differentiation, the process by which cells in different parts of a multicellular organism, all of which have the same genome, take on their unique characteristics and distinct abilities to function in certain ways. Thus, epigenetic changes are what allow human liver cells, for instance, to carry out different processes than stomach cells, despite having identical genomes. Almost all mammalian cells undergo this process of terminal differentiation, that is, once they have differentiated, they have “memory” of epigenetic changes and can only reproduce other similarly differentiated cells. Only stem cells retain totipotency, the ability to form any type of cell. Epigenetic changes can cause disease. Because one copy of a gene is often methylated or “silenced,” an individual inheriting a single copy of a recessive disease allele can show symptoms of the disease, even though that individual possesses a healthy allele. These individuals are said to be “hemizygous” for that trait or disease, which does not exhibit normal Mendelian inheritance patterns. This process of inactivating one copy of a gene, also called “imprinting,” often distinguishes the maternally inherited chromosome from the paternally inherited copy; some genetic diseases in humans are more likely to be caused by a disease allele on a specific parent’s chromosome. Epigenetic responses to carcinogens can alter regulation of the cell cycle, leading to can-
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cerous tumor growth, even if these carcinogens are not mutagens; that is, they do not alter the DNA sequence of a gene. See Also: DNA; DNA Repair. Bibliography. Vincenzo E. Russo, Arthur D. Riggs, Rob-
ert A. Martienssen (Eds), Epigenetic Mechanisms of Gene Regulation (Cold Spring Harbor Laboratory Press, 1996). David Stewart (Editor), Bruce Stillman (Editor), Epigenetics: Cold Spring Harbor Symposia on Quantitative Biology, Vol. 69, (Cold Spring Harbor Laboratory Press, 2004); Annie Dude University of Chicago
Epilepsy Epilepsy is one of the most common neurological disorders and affects people of any age, gender, race/ ethnicity, social class, and geographic location. It is a chronic condition influencing brain function characterized by discharge of excessive levels of neurons, resulting in seizures that vary in frequency, severity, and type. The causes of epilepsy vary as much as the people affected by the illness. For most people with epilepsy, experiencing seizures is sporadic, but the psychosocial consequences continually influence quality of life. Advances in medicine and specific research on the underlying causes of the disease, the reasons for spontaneous seizures, diagnostic measures, as well as the psychosocial impact on patients, families and communities have led to more effective treatments. What is Epilepsy? Epilepsy appeared in Indian and Babylonian medical texts dating back to 4500 b.c.e., with its name coming from the Greek word epilambanein meaning “to attack/seize.” The experience of a seizure was believed to be the result of supernatural forces, cycles of the moon, or spiritual possession. In modern times, the causes of epilepsy although not well understood include genetics, brain disease, substance abuse, parasites, febrile illness, and head injury/trauma. Not until the 17th and 18th centuries was epilepsy viewed as a medical disorder, and not until
For most people with epilepsy, experiencing seizures is sporadic, but the psychosocial consequences continually influence quality of life.
the establishment of the field of neurology was it thought of as a brain disorder. Epilepsy affects the brain through excessive release of neurons causing seizures that take on various forms based on the location and size of the area(s) affected. Generalized/ grand mal seizures are characterized by loss of consciousness and muscle stiffness and contraction. A variation on this are petit mal seizures usually with shorter periods of unconsciousness. The second type of seizure is partial or focal, which start in one part of the brain and can spread to other parts, leading to generalized seizures. Partial seizures may result in brief losses of attention or longer periods of mental absence. The third type, status epilepticus is characterized by frequent seizures without recovery, which if not treated can lead to brain damage or death. It is not well understood why people experience certain types of seizures, but triggers for their onset have been identified, including flashing lights, physical exertion, lack of sleep, or stress.
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Epidemiology of Epilepsy Although epilepsy does not discriminate based on sociodemographic characteristics, most diagnoses occur among infants, adolescents, and older adults. According to the World Health Organization (WHO), approximately 8.2 per 1,000 (50 million) people currently live with active epilepsy (experience reoccurring seizures or are in need of treatment). Developing nations have a much higher incident rate with 100 per 100,000 compared to 50 in developed nations. People with epilepsy have an increased risk of mortality attributed to underlying brain disease (i.e., tumor), having seizures at dangerous times (i.e., while swimming, driving, etc.), status epilepticus, respiratory failure during seizures, and suicide. PsychoSocial Consequences The psychosocial consequences of living with epilepsy can drastically influence a person’s quality of life. The psychological consequences include increased rates of mood and anxiety disorders, with the most common being depression and dysthymia. The underlying reasons for this are not well understood and have been attributed to the influence of epilepsy on the brain, anti-epileptic medications, disruptions in sleep, social factors, or various combinations. Anxiety is also more prevalent among people with epilepsy, characterized by feelings of fear, dread or uneasiness, and sometimes tied to the seizure experience or the result of not knowing when the next seizure will occur. A common social consequence of epilepsy is the restriction on driving, which can limit a person’s independence. People with epilepsy are also more likely to be on disability and not allowed to enter certain occupations where losses of consciousness could be dangerous (i.e., operating heavy machinery). Stigma, also a major consequence of living with epilepsy, can greatly alter social interactions. Moving toward a medical understanding of the disease along with increased public awareness have led to decreased levels of stigma, but it still exists. Stigma may especially be detrimental to children who may feel outcast by peer groups or reluctant to engage in activities out of fear of having a seizure. Studies have also documented the detrimental effect of epilepsy on education levels and marital status. Efforts made by groups such as the Global Campaign Against Epilepsy are essential to increase the quality of life among those with
epilepsy by raising public awareness and helping to reduce misunderstandings and stereotypes. Research and Treatment Increased knowledge about epilepsy is due to advances in understanding the brain and neurological function. Research on epilepsy generally falls into three areas including basic science (i.e., function of the brain and genetics), clinical (diagnosis and treatment), and psycho-social (i.e. how the experience of living with epilepsy influences quality of life). Treatment options are available depending on where you live (developed versus developing nation) and the ability to pay for it, and include pharmacotherapy (involving one or more antiepileptic medications) or brain surgery. According to WHO, 70 percent with epilepsy respond to treatment, and are able to control their seizures through these means, but nearly three-quarters of people in developing nations are unable to afford treatment. SEE ALSO: Seizures, Brain Diseases, Neurology BIBLIOGRAPHY. Thomas R. Browne and Gregory L. Hol-
mes, Handbook of Epilepsy, 3rd ed. (Lippincott Williams & Wilkins, 2004); Melissa A. Carran, et al., “Marital Status after Epilepsy Surgery,” Epilepsia (v.40/12, 1999); Epilepsy Foundation, “Mood,” www.epilepsyfoundation.org/about/ related/mood/types.cfm (cited June 2007); World Health Organization, “Epilepsy,” www.who.int/topics/epilepsy/en/ (cited July 2007). Noah J. Webster, M.A. Case Western Reserve University
Equatorial Guinea Equatorial Guinea, on the western coast of Africa, is smaller than the State of Maryland, has the smallest population of any country on the continent, and is the smallest Spanish-speaking nation in the world. Significant oil reserves were discovered in 1996, producing 420,000 barrels a day by 2005. On paper, Equatoguineans have the third highest per capita income in the world, just behind Luxembourg and Bermuda. In reality, the people see little evidence of these huge oil revenues, most of which goes directly into the pockets of the leadership.
Eritrea
President Teodoro Obiang Nguema has ruled the country as a semidictatorship since seizing power in a military coup in 1979. In recent years, Equatorial Guinea has become “one of the most paranoid, suspicious and xenophobic countries in Africa,” according to John Vidal, a Western journalist who made a rare trip inside the country in 2004. This apparently stems from Obiang’s fear that outside forces are plotting to steal the country’s oil reserves. This institutional paranoia makes assessing the health of Equatoguineans difficult. The population is estimated at approximately 540,000, with a annual growth rate of 2.05 percent. The birth rate stands at 35.59 births per 1,000 people and the death rate is believed to be 15.06 per 1,000. There is little migration. Fifty percent of the population live in urban areas. Life expectancy at birth is 48 years for males and 51 years for females, with healthy life expectancy at 45 years for men and 46 years for women. The fertility rate is 5.9 births per woman; maternal mortality rates stand at 880 deaths per 100,000 live births. Infant mortality is 103 deaths per 1,000, and 205 deaths per 1,000 for children aged 1–5. Both infant and child mortality rates have actually risen since 1990. Malaria, cholera, and yellow fever remain serious problems in Equatorial Guinea. (The regional strain of malaria has reportedly grown resistant to chloroquine, usually the most effective form of treatment.) With little potable water available to Equatoguineans, gastroenteritis and parasitic diseases are endemic. AIDS statistics are hampered by what the Joint United Nations Programme on HIV/AIDS (UNAIDS) calls “irregular” surveillance. It estimates the adult prevalence rate at 3.2 percent, with 8,900 adults currently infected. There are little data on treatment rates or attempts by the government to quell the spread of the virus. Increased government revenues have not gone into medical care; per capita spending on healthcare is estimated at $65. There are still limited hospital facilities throughout the small country. The U.S. Department of State notes that payment is usually required up front for any medical services, and that patients are often required to provide their own bed linens and, frequently, their own bandages and dressings. In 2004, there were 153 physicians, 228 nurses, and 43 midwives working in the country. SEE ALSO: Healthcare, Africa.
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Bibliography. Encyclopedia of the Nations, http://www.
nationsencyclopedia.com/Africa/Equatorial-GuineaHEALTH.html (cited July 2007); World Health Organization, “Equatorial Guinea.” http://www.who.int/countries/ gnq/en/ (cited July 2007); “Equatorial Guinea—Health.” Heather K. Michon Independent Scholar
Eritrea Eritrea is a small country on the eastern coast of Africa, bordering on the Red Sea. Endlessly at war with its southern neighbor Ethiopia and mired in drought, Eritreans have faced many hardships in recent years, many of them having an impact on the general health and welfare of the people. The total population is approximately 4,790,000 and growing at a rate of 2.47 percent annually. The birth rate is 34.33 per 1,000 and the death rate is 9.6 per 1,000; there is little or no migration. Life expectancy at birth is 58 years for males and 62 years for females, with healthy life expectancy at 49 years for men and 51 years for women. Eritrea is overwhelmingly rural, with just 21 percent of the population living in urban areas. Most Eritreans are subsistence farmers. Gross national income is $145 annually. Eritrea has had to cope with back-to-back disasters since the late 1990s. Between 1998 and 2000, more than 1 million Eritreans were displaced by war with Ethiopia, with another 70,000 to 100,000 reportedly killed. (There are an estimated 70,000 still living in refugee camps around the country.) In 2000, a severe drought led to a total crop failure. Recent years have seen crop yields rebound slightly, but not enough to stave off persistent food insecurity. In 2005, the United Nations estimated that 2.2 of 3.8 million Eritreans lacked adequate food supplies. Access to potable water is limited to about 44 percent of the population and only 9 percent use sanitary facilities—a mere 3 percent in rural areas. Malaria, tuberculosis, human immunodeficiency virus (HIV)/ AIDS, and malnutrition account for 60 percent of all outpatient cases and 40 percent of inpatient admittances in 2003. These four conditions were responsible for 56 percent of the deaths among inpatients in
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2003, a figure which increased in 2004. Acute respiratory infections are also a problem, accounting for more than 17 percent of hospital cases. Immunization rates among children are good in most areas, although not good enough in some regions to prevent localized measles epidemics. Infant mortality is 50 per 1,000 and child mortality is 78 per 1,000. Under-5 mortality has been cut in half since 1990. Eritrean women face many challenges. Child marriage is widely practiced, with about 60 percent of rural teens wed before the age of 16 (as are 31 percent of urban children). Female genital mutilation (FGM) is widespread, with a 1997 survey finding 90 percent of women reporting they had undergone some type of FGM in youth. In many areas, the cutting is performed in infancy, and in most of Eritrea, is rarely performed after the age of 7. The most radical form, type III or infibulation (including the removal of the clitoris and labia and sewing shut of the vaginal area) is performed mainly in the northern regions of the country, while type I (clitoridectomy) or type II (removal of the clitoris and labia minora) are spread throughout the country. Early marriage and childbearing contributes to a high maternal mortality rate of 630 per 100,000 live births. Seventy percent of all births happen at home, with just 28 percent under the supervision of a trained attendant. An uncounted number suffer from obstetric fistula, an injury of childbearing that leaves an open hole in the birth canal which leads to chronic fecal and urinary incontinence. Only 8 percent of Eritrean women have access to birth control. Women account for more than half of all HIV/AIDS cases within the country. The adult prevalence rate for HIV/AIDS is estimated at 2.4 percent. There are 59,000 Eritreans living with HIV/AIDS, 31,000 of them women. Ongoing internal and cross-border instability has made it difficult for the government or international organizations to craft a national plan to combat the spread of the virus or other sexually transmitted diseases. Delivery of healthcare services is uneven at best. Hospitals are understaffed, poorly equipped, and lacking in critical drug inventories. There are about 215 physicians and 2,500 nurses working within the medical system (excluding those working with nongovernmental organizations). With so much of the population living outside the cities, the sick or injured often face long treks to the nearest health centers. Once they reach care, they must try to find the money to pay for
services: patients are responsible for 100 percent of medical expenditures. Per capita spending on healthcare by the government amounts to about $4 a year. SEE ALSO: Healthcare, Africa. Bibliography. World Health Organization, “Eritrea,”
http://www.who.int/countries/eri/en/ (cited July 2007); “Teenage Childbearing and Child Health in Eritrea, RePEc (Research Papers in Economics), http://ideas.repec.org/p/ dem/wpaper/wp-2005-029.html (cited June 2007). Heather K. Michon Independent Scholar
Esophageal Cancer Esophageal cancer is a malignant (cancerous) growth which occurs in the muscular tube connecting the throat to the stomach. The main function of the esophagus is to aid in the passage of food and liquids from the throat to the stomach. The occurrence of cancer in this part of the body interferes with these normal functions. The two most common types of esophageal cancer are squamous cell carcinoma (also known as epidermoid carcinoma) and adenocarcinoma. Together, these account for over 95 percent of all esophageal cancers. Typically, the former occurs in the upper to middle portion of the esophagus, whereas the latter usually affects the lower third of the esophagus. Unfortunately, early-stage esophageal cancer often goes unnoticed because the individual typically does not suffer from symptoms of this disease until it has progressed to a later stage. This, alongside the lack of a serosal barrier makes the prognosis for esophageal cancer generally poor. The method of treatment and prognosis for esophageal cancer depends very much on the stage the cancer is classified as once identified. Both squamous cell carcinoma and adenocarcinoma each have their own etiologies (causes), and are therefore often studied separately by researchers in this respect. Common to both esophageal squamous cell carcinoma (SCC) and adenocarcinoma (AC), factors such as sex, race, economic status, as well as geographical location have been found to play a
role in the risk of developing one type of esophageal cancer over another, making this disease a global health phenomenon. Although the causes of SCC and AC are very different, the symptoms are often similar. For instance, persons who are diagnosed with esophageal cancer frequently describe symptoms that include progressive difficulty with swallowing foods and/or liquids (a medical condition referred to as dysphagia), hoarseness, chest pain, and significant weight loss. Common symptoms of a more advanced stage of esophageal cancer includes painful swallowing (also known as odynophagia) and regurgitation, which are often the result of a large tumor causing an obstruction within the esophagus. A barium swallow (a type of X-ray test) is most often used to identify whether an individual potentially has esophageal cancer. If further investigation is required, typically an endoscopy (the use of a lighted, flexible instrument called an endoscope, to examine the inside of certain parts of the body such as the esophagus) accompanied by a biopsy (the removal and examination of a sample of tissue) are used to better identify the disease. The cancer can be classified from stage I (small, localized, and usually curable cancer) to stage IV (cancer which has spread and is inoperable). There is also the TNM (tumor, node, metastases) system which can be used to classify solid tumors. Generally, late-stage esophageal cancer (i.e., stage III or IV) makes treatment options such as surgery, chemotherapy, and radiation to be palliative (to alleviate symptoms relating to the disease) rather than curative (to eliminate the disease). Photodynamic therapy (PDT) has also been administered as both a palliative and curative treatment method. The former has been used in advanced cancers to alleviate dysphagia and the latter has been used in early-stage esophageal cancer (i.e., a precancerous lesion). There are two well-documented conditions that have been found to contribute to the development of esophageal AC, these include 1.) gastroesophageal reflux disease (GERD) and 2.) Barrett’s esophagus (BE). The symptoms associated with GERD include frequent episodes of heartburn and reflux (gastric contents splashing back up into the esophagus) particularly after the consumption of certain foods or proceeding certain movements (i.e., laying down,
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sitting up, etc.). GERD causes a degree of damage to the esophageal mucosa which may become a serious problem if it manifests into a chronic condition. Chronic GERD, or an inflammation of the esophagus (esophagitis) can result in BE, which is a precursor for esophageal AC. BE is a condition where the cells in the lower end of the esophagus have undergone an abnormal change in cells (metaplasia) either resembling the lining of the stomach or of the intestines. Two different online books edited by Holzheimer and Mannick, and Thomson and Shaffer provide chapters specifically dedicated to the esophageal conditions, disorders, symptoms, and the treatment of esophageal neoplasms; these sources are recommended for further reading. Other documented risk factors of AC include hiatal hernia, being overweight, reduced lower sphincter pressure, diet, and to some degree, tobacco and alcohol consumption. There are a number of aspects relating to diet that have been associated with SCC, these are particularly relevant to high-risk regions of China and in some African and Far East countries. Poor dietary habits (i.e. consumption of high starchy foods and a diet low in fresh fruits and vegetables) as well as the occurrence of Plummer-Vinson syndrome (a complex vitamin deficiency) are amongst these. The consumption of dietary carcinogens such as nitrosamines (which have been detected in various foods and drinking water) and n-nitroso compounds (found in pickled or moldy foods) have also been implicated for their role in SCC occurrence. Chronic irritation and inflammation of the esophagus have also been found to be of major importance in the etiology of SCC. For instance, the consumption of scratchy foods as well as the practice of eating food rapidly without sufficient mastication are qualities amongst those with SCC in the high-risk region of Northern Iran. Additionally, the consumption of foods and drinks (particularly hot mate tea) at extremely high temperatures, chronic esophagitis, previous lyeinduced injury, and exposure to silica fibers and other occupational exposures and fumes, have also been suspected in SCC’s etiology. Other possible risk factors include disorders such as achalasia (an abnormal function of esophageal nerves and muscles which make swallowing difficult), esophageal diverticulum (an outpocketing of the esophageal wall), and tylosis (a genetic disorder), and human papillomavirus.”
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Most esophageal cancers that occur in the world are SCC. The highest rates of SCC occur in poor regions of the world and equally affect males and females. In the Western world this is not the case; AC is more common than SCC. Nevertheless, SCC that occurs in the Western world disproportionately affects men (especially those that are single) and certain races. For instance, rates were elevated almost four to five times higher for black women and men in comparison to white women and men with SCC. The occurrence of esophageal cancer is infrequent before 40 years of age, with the exception of some regions found within the “esophageal cancer belt” region of the world. The esophageal cancer belt, located in central Asia, “is an area that stretches eastward from Iran through Turkmenistan, Northern Afghanistan, Uzbekistan, and Kazakhstan into Northern China and Mongolia” (Kuska, 2001). Recent studies have provided evidence that the geographical limits of the esophageal cancer belt has been extended southwest to Quetta, Balochistan, located in Pakistan (Roohullah, et al., 2001; Bhurgri, et al., 2002). There have been other documented high-risk areas in the world (unrelated to the esophageal cancer belt region); among some of these are regions within France, Uruguay, and Transkei. Over the past two decades, AC has been on the rise throughout North America and parts of Europe, especially among white men. A number of hypotheses have been put forth to explain this increase by identifying possible risk factors for this disease. Some of the main explanations suggested for this increase, and warranting further research, have been succinctly noted by J. Lagergren to include (1) the increased frequency of GERD, (2) an increase in the use of medication which contributes to reduced sphincter pressure, and (3) an increase in the rate of obesity (which is thought to increase intraadominal pressure). Some studies have examined the role of workplace exposures in relation to increasing AC trends and the male predominance only to report minor to no influence in this regard (Jansson, et al., 2006; Jansson, et al., 2005; Engel, et al., 2002). Nevertheless, several researchers have noted the possibility of environmental exposures as the culprits for this dramatic increase. Numerous studies have been conducted which examine the various causes of esophageal cancer as de-
A drawing of esophageal cancer surgery, where the cancer and nearby tissue are removed and the stomach is joined to the esophagus.
scribed above. Amongst these, several studies have found some association with occupational exposures in relation to esophageal cancer, particularly those associated with exposures to silica dust and chemical solvents or detergents (Yu, et al., 2005; Cucino and Sonnenberg, 2002; Tsuda, et al., 2001; Sullivan, et al., 1998; Ruder, et al., 1994). In North America, esophageal cancer still disproportionately affects males, and those of certain races. For instance, in a report written by the U.S. Cancer Statistics Working Group in 2005, it was found that in the United States (based on 17 Surveillance, Epidemiology, and End Results Program [SEER] areas) esophageal cancer incidence ratios per 100,000 for the years 2000-2003 were 10.8:3.3 for black men in comparison to black women. Further, 7.8:1.9 incidence ratios for white men in comparison to white women were reported. Socioeconomic class has also been found to play a role in esophageal cancer incidence in much of the literature, with the exception of a study conducted by Bossetti, et al., (2001) in Italy which showed that there was a disappearance of the social gradient amongst esophageal cancer (and other upper digestive tract cancers) in the 1990’s that was once identified amongst this population in the 1980’s. Allen Pickens and Mark B. Orringer provide an overview of the geographical distributions and racial disparities of esophageal cancer. As evidenced by global statistics provided by Ferlay and colleagues (2004), worldwide esophageal cancer not only disproportionately affects more
males than females, its highest incidence rates can be found in certain areas of the world; amongst these are Eastern and Southern Africa and Eastern and South-Central Asia. These rates are consistent with those previously reported by Ferlay, et al., (2001). The only drastic changes between the global statistics reported for esophageal cancer in 2001 in comparison to those reported in 2004 are those pertaining to Fiji. Esophageal cancer incidence rates for Fiji were reported at more than nine times higher for males and more than four times higher for females compared to rates reported in 2001. However, these rates should be interpreted with caution since issues related to registry collection may be to blame for this increase (i.e. a change in compliance in reporting; a change in resources required to retrieve data, etc.,). Therefore, these reported increased rates may not necessarily be the result of an actual increase in risk over the years. In order to better understand the underlying issues and implications surrounding the incidence of esophageal cancer, further investigation of discrepancies which exist amongst sex, race, economic status as well as geographical location are necessary.” SEE ALSO: Cancer (General); Surveillance, Epidemiology,
and End Results Program (SEER).
Bibliography. Y. Bhurgri, et al., “Cancer Patterns in
Quetta (1998–1999),” The Journal of the Pakistan Medical Association (v.52/12, 2002); William J. Blot, et al., “Rising Incidence of Adenocarcinoma of the Esophagus and Gastric Cardia,” Journal of the American Medical Association (v.265/10, 1991); C. Bosetti, et al., “Changing Socioeconomic Correlates for Cancer of the Upper Digestive Tract,” Annals of Oncology (v.12/3, 2001); Linda Morris Brown, et al., “Excess Incidence of Squamous Cell Esophageal Cancer among U.S. Black Men: Role of Social Class and Other Risk Factors,” American Journal of Epidemiology (v.153/2, 2001); Linda Morris Brown, et al., “Chapter 1: Epidemiology of Esophageal Cancer,” in M. C. Posner, E. Vokes, R. Weichselbaum, eds., Cancer of the Upper Gastrointestinal Tract (Decker, 2002); Claudia Cucino and Amnon Sonnenberg, “Occupational Mortality from Squamous Cell Carcinoma of the Esophagus in the United States during 1991–1996,” Digestive Diseases and Sciences (v.47/3, 2002); Lawrence S. Engel, et al., “Occupation and Risk of Esophageal and Gastric
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Cardia Adenocarcinoma,” American Journal of Industrial Medicine (v.42/1, 2002); Jacques Ferlay, et al., GLOBOCAN 2000: Cancer Incidence, Mortality and Prevalence Worldwide, Version 1.0, IARC Cancer Base No. 5 (IARC Press, 2001); Jacques Ferlay, et al., GLOBOCAN 2002: Cancer Incidence, Mortality and Prevalence Worldwide IARC CancerBase No. 5. Version 2.0 (IARC Press, 2004), http://www-dep.iarc.fr/ (cited October 2006); P. Ghadirian, “Food Habits of the People of the Caspian Littoral of Iran in Relation to Esophageal Cancer,” Nutrition and Cancer (v.9/2–3, 1987); P. Ghadirian, J. Vobecky, and J. S. Vobecky, “Factors Associated with Cancer of the Oesophagus: An Overview,” Cancer Detection and Prevention (v.11/3–6, 1988); P. Ghadirian, J. M. Ekoe, and J. P. Thouez, “Food Habits and Esophageal Cancer: An Overview,” Cancer Detection and Prevention (v.16/3, 1992); René G. Holzheimer and John A. Mannick, “Surgical Treatment: Evidence-Based and Problem-Oriented,” http://www.ncbi.nlm.nih.gov/books/bv.fcgi?rid=surg (cited October 2005); Catarina Jansson, et al., “Socioeconomic Factors and Risk of Esophageal Adenocarcinoma: A Nationwide Swedish Case Control Study,” Cancer Epidemiology, Biomarkers and Prevention (v.14/7, 2005a); Catarina Jansson, et al., “Occupational Exposures and Risk of Esophageal and Gastric Cardia Cancers among Male Swedish Construction Workers,” Cancer Causes and Control (v.16/6, 2005b); Catarina Jansson, et al., “Airborne Occupational Exposures and Risk of Oesophageal and Cardia Adenocarcinoma,” Occupational and Environmental Medicine (v.63/2, 2006). Ann Novogradec, Ph.D. York University, Toronto
Esophagus Disorders The esophagus is the second part of the digestive tract, following the mouth and preceding the stomach. It is a tube that propels food down to the stomach, via rhythmic wave-like contractions called peristalsis. There are many esophageal disorders, but most have two particular symptoms. The first symptom is general chest or back pain. The second symptom is a difficulty in swallowing, called dysphagia. Esophageal disorders can be caused by an injury or an
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obstruction, or esophageal bleeding or cancer. Other disorders may affect peristalsis; these disorders are called propulsion-related esophagus disorders. In order to keep oral and gastric contents out of the esophagus while a person is not swallowing, the esophagus is flanked by two muscular sphincters. As a normal part of aging, these sphincters become weaker and sometimes cannot keep acidic stomach contents from entering the esophagus. This condition is called presbyesophagus, with the prefix ‘presby’ signifying the condition’s relationship to old age. Some younger people experience periodic gastric acid reflux, another example of the acidic stomach chyme entering the esophagus abnormally. The healthy esophagus is protected by a thick layer of tough cells which line the esophagus. These epithelial cells are of the squamous cell type. A person with chronic acid reflux may have a weakened or damaged esophageal lining. People suffering from bulimia who force themselves to vomit also damage their esophageal lining. Any cell population that is continuously replenishing itself and therefore undergoing genetic replication is at an elevated risk for developing cancer. The continuous genetic replication cycles can promote a mutation that might otherwise be inconsequential. Forced vomiting or acid reflux disease, add undo stress to the cells lining the esophagus, leading to an enhanced rate of cellular division while the esophagus tries to repair itself. This enhanced division rate also increases the risk of developing esophageal cancer. Esophageal cancer begins in the innermost cell layer lining the esophagus. In the past, esophageal cancer was difficult to treat and survival was rare. Today, a precancerous condition known as Barrett’s esophagus can be recognized early, when cancer treatment is most effective. Barrett’s esophagus is a result of acid reflux disease. Smoking and drinking in excess can also strain the esophagus and predispose it to cancer. Other risk factors include age above fifty-five years, male gender, being African American, being overweight, eating a diet poor in fruits and vegetables, and working in professions with exposures to certain chemicals such as dry cleaning solutions and construction materials, and other toxins or irritants such as during mining. Crohn’s disease is a chronic disorder of the digestive tract that often affects the large intestine,
though it can affect the tract from the esophagus to the rectum. It is an inflammatory disorder that may be auto-immune. It may have genetic components, but often the cause is idiopathic, meaning it is unknown. The inflammation can result in pain and difficulty in eating. Crohn’s patients can attempt to keep the disorder in check by following a diet regimen that avoids aggravating foods while maintaining proper nutrition, taking corticosteroids and antibiotics if necessary, and painkiller medications. A supplement of vitamin E may need to be added to the diet, as Crohn’s patients may not absorb enough vitamin E from a regular diet. The disease typically inflames during periods of high stress or after exerting physical activity. Developmental disorders and physical malformations can also lead to dysphagia. Loss of coordination in the normally rhythmic contractions of the musculature encircling the esophagus can lead to difficulties with swallowing, food regurgitation, or choking. Other causes of esophageally located dysphagia that are not directly due to the esophagus include movement disorders such as Parkinson’s disease or Huntington’s disease. Certain medications and other drugs may also cause dry mouth, which will affect the ability of food to travel down the esophagus. In the United States, the primary funding source for scientific investigations into disorders of the esophagus is the National Institute of Diabetes and Digestive and Kidney Diseases, part of the National Institutes of Health. SEE ALSO: Acid Reflux; Bulimia; Esophageal Cancer;
Gastroenterologist, Gastroenterology; National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK); National Institutes of Health; Otolaryngologist; Otolaryngology. Bibliography. Antonio Carminati, New Research on
Esophageal Cancer (Horizons in Cancer Research) (Nova Science Publishers, 2006); Randi E. McCabe MD, Traci L. McFarlane MD, and Marion P. Olmsted PhD, Overcoming Bulimia: Your Comprehensive, Step-by-Step Guide to Recovery (New Harbinger Self-Help Workbook) (New Harbinger Publications, 2004); Tracie M. Dalessandro MS RD CDN, What to Eat with IBD: A Comprehensive Nutrition and Recipe Guide for Crohn’s Disease and Ul-
Estonia
cerative Colitis (iUniverse, Inc., 2006); Thomas Murry and Ricardo Carrau, M.D., Clinical Management of Swallowing Disorders (Plural Publishing, 2006); Henry Parkman and Robert S. Fisher, The Clinician’s Guide to Acid / Peptic Disorders and Motility Disorders of the Gastrointestinal Tract (The Clinician’s Guide to GI Series) (Slack Incorporated, 2006); Richard E. Sampliner, Ajay Bansal, Jacques Bergman, and Navtej Buttar, Barrett’s Esophagus and Esophageal Adenocarcinoma (Blackwell, 2006). Claudia Winograd University of Illinois
Estonia Since the dissolution of the Soviet bloc, Estonia has maintained strong ties with the West. The economy is largely dependent on the electronics and telecommunications sectors and on trading relations with Finland, Sweden, and Germany. With a per capita income of $17,500, Estonia ranks 58th in world incomes. The Gini coefficient for Estonia is 37.2. The richest 10 percent hold 29.8 percent of the country’s wealth while the poorest 10 percent share only three percent. Unemployment stands at 7.9 percent and inflation at 4.1. Although Estonia has a low external debt, the budget deficit draws needed resources away from social programs. The United Nations Development Programme’s (UNDP) Human Development Report ranks Estonia 40th among 177 countries on overall quality of life issues. During the transition to a market economy, the government attempted to turn Estonia into a social welfare state, implementing the Estonian Healthcare Project (1995–98) according to World Health Organization guidelines to improve the quality of healthcare. In 2001, the Health Services Act set quality controls on healthcare and established the Healthcare Board. A social tax designed to generate funding for health services, pensions, and child benefits was also implemented. Despite good intentions, the government could not absorb the costs of the program, so benefits were reduced. Local governments were assigned the responsibility for administering social assistance, and living and housing allowances were abolished. The elderly were disproportionately affected by the changes.
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Between 1993 and 2004, Estonia spent an average of 16 percent of the budget on healthcare. The government now commits 5.3 percent of the Gross Domestic Product (GDP) to healthcare, allotting $682 (international dollars) per capita. Government funding provides 77.1 percent of total health expenditures, and 84.9 percent of that amount is earmarked for social security. In Estonia, social security is a combination of social insurance and mandatory individual accounts. Employees do not pay for the program, but the self-employed pay one-third of the minimum salary, and employers are required to contribute onethird of payrolls. The program covers the elderly, the disabled, and survivors. The private sector furnishes 22.9 percent of healthcare costs, and 88.30 percent of private provisions are derived from out-of-pocket expenses. When out-ofpocket expenses are high, the poorest segment of the population may be unable to afford healthcare or may be impoverished by meeting healthcare costs. Household budget surveys have indicated that the number of households spending more than one-fifth of their capacity to pay for healthcare rose steadily between 1995 and 2002. Again, the elderly who are require constant care and large amounts of medication are disproportionately affected. There are 4.48 physicians, 8.50 nurses, 0.34 midwives, 1.28 dentists, and 0.42 pharmacists per 1,000 population in Estonia. Estonia’s population of 1,324,333 has a life expectancy of 72.04 years. The gap between male (66.58 years and female (77.83 years) is wider than in most countries. Literacy is virtually universal at 99.8 percent. While 99 percent of children attend primary school, enrollment drops slightly at the secondary level. Seventy percent of Estonian women use birth control, giving birth to an average of 1.4 children each. All births are attended by trained personnel. However, Estonia’s adjusted maternal mortality rate of 63 deaths per 100,000 live births is relatively high. The current infant mortality rate is 7.73 deaths per 1,000 live births. Between 1990 and 2004, Estonia cut infant and under-five mortality in half, reducing rates from 12 to six deaths per 1,000 live births and from 16 to eight deaths per 1,000 live births, respectively. Four percent of all infants experience low birthweight. In most cases, immunization rates are high in response to government and international
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commitment. Ninety-nine percent of infants are immunized against tuberculosis; 98 percent against diphtheria, pertussis, and tetanus (DPT1) 96 percent against measles; and 95 percent against polio. Other immunization rates are lower, and the percentage of infants receiving DPT3 vaccinations drops to 94 percent, and only 90 percent receive hepatitis B vaccinations. The lowest immunization rate is found among infants inoculated against Haemophilus influenzae type B (27 percent). Air and water pollution became major issues in Estonia during the socialist decades, but the government has been successful in precipitating a steady decline, reducing emissions by 80 percent between 1980 and 2000. At the same time, levels of untreated waste being discharged into water sources were reduced by one-twentieth. HIV/ AIDS poses threat to Estonians, with a 1.1 percent adult prevalence rate. Around 7,800 people are living with the disease, and some 200 have lost their lives. See Also: Finland; Sweden; World Health Organization
(WHO).
Bibliography. William H. Berqquist, Freedom: Narra-
tives of Change in Hungary and Estonia (Jossey-Bass, 1994); Central Intelligence Agency, “Estonia,” World Factbook, www.cia.gov/cia/publications/factbook/geos/en.html; Jarno Habicht, et al, “Detecting Changes in Financial Protection: Creating Evidence for Policy in Estonia,” Health Policy and Planning (November 2006); Martin A. Levin and Martin Shapiro, eds., Transatlantic Policymaking in an Age of Austerity: Diversity and Drift (Georgetown University Press, 2004); Kaja Polluste, et al., “Quality Improvement in the Estonian Health System Assessment of Progress Using an International Tool,” International Journal for Quality in healthcare (v.18/6, 2006). Elizabeth R. Purdy, Ph.D. Independent Scholar
Estrogen Replacement Therapy (ERT) Estrogen is a group of hormones present in women that regulate sexual characteristics, including growth, maturation, and reproduction. Estrogen production
declines during menopause, when the body moves into a stage in which pregnancy and childbirth are no longer possible, although other functions continue as normal. This occurs on average between the ages of 45–55 in women in developed countries. The lack of estrogen causes a number of symptoms which can be troublesome to quality of life, including hot flushes, emotional disturbance, and sleeplessness, while also representing an often unwelcome constant reminder to the woman of the change of physical status she is undergoing. Within the woman, the ovaries cease to produce estrogen and the same effect can be produced by surgery, for example as a result of a hysterectomy. In some cases, therefore, medical practitioners may prescribe estrogen replacement therapy (ERT) as a means of controlling these symptoms. ERT is a subset of hormone replacement therapy (HRT), which also includes the replacement of other types of hormones for a variety of medicinal purposes. Postmenopausal women may suffer from the demineralization of bones and related conditions, including osteoporosis and atrophic vaginitis. Estrogen replacement may be effective in countering these threats and so may be prescribed, either through an orally or dermally administered procedure. The hormone may also be administered through the vagina. Estrogen administered alone (“unopposed”) is effective in treating postmenopausal symptoms, reduces osteoporosis threat, and has other benefits, but it has not been established how quickly this works on an individual basis and in the level of dosage required. However, there are negative side effects associated with unopposed estrogen replacement, not least of which is the elevated threat of various kinds of cancer, which is a threat that may persist beyond using ERT treatments. More research is necessary to determine which forms of estrogen pose higher risks than others, what is the time scale involved, and which groups of women may be at higher levels of risk than others, as well as explaining why that might be. As a result of this, medical practitioners now generally recommend using estrogen in combination with other substances, in a format known as “opposed.” It is most common for estrogen to be combined with progestin in this way; progestins are another type of hormone which are involved with regulating the maintenance of pregnancy.
Ethiopia
Estrogen combined with progestin make up the oral contraceptive. Unfortunately, the combination of opposed estrogen also produces often-distressing and uncomfortable side effects, including bloating, bleeding, and depression. Additionally, the long-term effects of the treatment are not clear and there is research exploring the link between opposed and unopposed ERT and the elevated incidence of breast cancer, coronary disease, and Alzheimer’s disease, especially among older women. It seems clear that women do respond differently to different regimes of estrogen and progestin and that important factors include age and the presence of an intact womb or otherwise. Medical advice should be sought to determine what is considered most appropriate in the individual case. Researchers continue to experiment with varied doses and dosage protocol to shed further light on these issues. Generally, the levels of estrogen recommended have decreased over time. Daily dosage is now commonly set at 0.625 mg per day, which is only one-quarter of doses recommended in the past. ERT became particularly popular—or at least more commonly prescribed—in the 1960s and 1970s in the United States and then declined as emergent risks became known. Currently, some 15 to 20 percent of American women will use ERT in one form or another. Some reject the idea because of the belief that synthetic products should not interrupt natural processes or because of fear of side effects or because of lack of good-quality information. Given the continuing lack in specific knowledge in particular, important areas of knowledge, as well as the need to balance benefit and risk in the case of individual patients, it would be prudent to seek individualized advice before deciding whether the benefits outweigh the risks for women suffering from symptoms specified above. SEE ALSO: Hormones; Menopause. Bibliography. Lynn Rosenberg, “Hormone Replacement
Therapy: The Need for Reconsideration,” American Journal of Public Health (v.83/12, 1993); Ronald K. Ross, et al., “Effect of Hormone Replacement Therapy on Breast Cancer Risk: Estrogen versus Estrogen plus Progestin,” Journal of the National Cancer Institute (v.92/4, 2000); Richard L. Tannen, et al., “Estrogen Affects Post-Menopausal Women Differently than Estrogen plus Progestin Replacement
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Therapy,” Human Reproduction (v.22/3, 2007), published online ahead of print publication. John Walsh Shinawatra University
Ethiopia Ethiopia, on the eastern edge of Africa, is an ancient land. For centuries, it served as the crossroads of Arab and African culture. It is the second oldest Christian country; its rich artistic and cultural heritage is undeniable. Virtually alone among its neighbors, it managed to remain independent during decades of European imperialism. However, the final decades of the 20th century and the first years of the 21st century have not been easy for the people of Ethiopia, bringing widespread famine, war, and disease that killed millions of people. With 74,800,000 residents, Ethiopia is the second most populous country in Africa after Nigeria. The population is growing at a rate of 2.31 percent annually. Only 16 percent of Ethiopians live in urban areas. Eighty percent live on less than $2 a day; per capita income is below $100 a year. Agriculture and subsistence farming is the linchpin of the economy. Life expectancy at birth is currently 49 years for males and 51 years for females, with healthy life expectancy at 41 years for men and 42 years for women. Infant mortality rates have dropped slightly since 1990, now standing at 109 deaths per 1,000 live births. Mortality for children between the ages 1–5 has also edged down, dropping from 204 per 1,000 in 1990 to 164 per 1,000 in 2005. Maternal mortality is high, with 850 deaths per 100,000 live births. Only 28 percent of women receive any kind of prenatal care, and 6 percent have a trained attendant present at birth. Fifteen percent have access to birth control. As it is across the Horn of Africa, female genital mutilation (FGM) is widely practiced in Ethiopia. Sanitation and clean water access is scarce, with 22 percent of Ethiopians able to use potable water and 13 percent using sanitary facilities (figures drop significantly outside the cities, where only 11 percent have clean water and 7 percent have safe latrines). This leads to a high risk of food- and waterborne illness such as bacterial and protozoal diarrhea, hepatitis A, and typhoid fever.
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European Association for Cancer Research (EACR)
Malaria, meningitis, and malnutrition are among the biggest health issues in Ethiopia today, with human immunodeficiency virus (HIV)/AIDS and tuberculosis following closely behind. Malaria cases have grown from 1.1 million in 1995 to 6.1 million in 2003. There were widespread outbreaks of meningitis in 2000, 2001, and 2002. A 2005 survey found 38 percent of the population underweight and 47 percent showing signs of stunting from long-term malnutrition. In the Somali region, almost 24 percent of the population were found to suffer from acute malnutrition. About 2.5 million were in need of supplemental food aid in 2006 alone. The adult prevalence rate for HIV/AIDS is estimated at 2.8 to 6.7 percent of the population, with between 950,000 and 2.3 million Ethiopians currently infected. Five thousand new cases are contracted every week. The Ministry of Health counted just under 25,000 people receiving antiretroviral medications in 2005; the estimated number of patients in need was 211,000. There are about 400 testing sites spread across a country two-thirds the size of Alaska. Government expenditures on healthcare works out to about $3 per capita. The U.S. Department of State describes medical facilities in Addis Ababa as “limited,” and virtually nonexistent outside the city. Doctors are generally well trained but hampered by poor hospital facilities, out-of-date equipment, and inadequate drug inventories. There were 1,936 physicians and 14,900 nurses working in the country in 2004. SEE ALSO: Healthcare, Africa. Bibliography. Helmut Kloos and Zein Ahmed Zein, eds.
Health, Disease, Medicine and Famine in Ethiopia: A Bibliography (Greenwood Press, 1991); World Health Organization, “Ethiopia,” http://www.who.int/countries/eth/eth/en/ (cited June 2007). Heather K. Michon Independent Scholar
European Association for Cancer Research (EACR) Established in 1968, the European Association for Cancer Research (EACR) is made up of over 5,000
members and is dedicated to the advancement of cancer research throughout Europe. Membership is open to those who possess an academic degree or the equivalent and have held an appointment or worked actively in cancer research for at least two years. Different membership levels include active, student, emeritus, honorary, distinguished, and sustaining members. The first five categories of membership are open to individual scientists as well as members of scientific societies engaged in cancer research. The last category is open to organizations in recognition of regular contributions to the aims and activities of the Association. Members are elected according to the EACR’s bylaws. The Association strives to foster communication with laboratory, translational, and clinical cancer researchers in all areas of oncology from basic research to prevention, treatment, and care. The Association also promotes opportunities for collaborative research with and within other Member Societies of the Federation of European Cancer Societies (FECS), of which EACR is a founder member, including the European Society for Medical Oncology (ESMO), European Society of Surgical Oncology (ESSO), European Society for Therapeutic Radiology and Oncology (ESTRO), European Branch of the International Society of Pediatric Oncology (SIOP), and European Oncology Nursing Society (EONS). To promote the efforts of new generations of healthcare professionals, the EACR sponsors education and training for the young cancer researcher through free membership for postgraduate students, and fellowships to promote technical exchange. The EACR also gives awards for lectures and posters at meetings, and sponsors special programs to assist researchers in eastern Europe, and promotes Young Investigators Forums to generate ideas for developing and enhancing the EACR. The General Assembly, as the supreme governing body of the Association, is composed of the membership of the EACR. The Executive Committee conducts the affairs of the Association and is advised by the Council which consists of elected representatives from each major European country. The European Journal of Cancer is the official journal of the EACR, the European Organization for Research and Treatment of Cancer (EORTC), the European School of Oncology (ESO), the FECS and the European Society of Mastology (EUSOMA). It is an international comprehensive
European Association for the Study of Obesity (EASO)
oncology journal that publishes original research, editorial comments, review articles, and news on experimental oncology, clinical oncology (medical, pediatric, radiation, surgical), and cancer epidemiology and prevention. The Journal’s editorial board is made up of some of Europe’s leading professionals in various fields of cancer research. The EACR also produces newsletters and a number of reports to disseminate useful information to its membership and each year sponsors a number of regional meetings as well as a major annual conference. See Also: Cancer (General); American Cancer Society
(ACS).
Bibliography. British Association for Cancer Research,
www.bacr.org.uk (cited September 2006); European Association for Cancer Research, www.eacr.org (cited September 2006); Federation of European Cancer Societies, www. fecs.be/emc.asp (cited September 2006); Joseph G. Sinkovics and Joseph Horvath, eds., Viral Therapy of Human Cancers (Informa Healthcare, 2004).
Ben Wynne, PH.D Gainesville State College
European Association for the Study of Obesity (EASO) The European Association for the Study of Obesity (EASO) was founded in 1988. It is headquartered in London and currently has more than 2,500 members from 27 different countries. Members represent a wide range of professions including sports specialists, dieticians, physicians, and scientists. EASO promotes research into obesity, facilitates contact and collaboration between organizations and individuals, and seeks to educate professionals and the public on the epidemic of obesity. The Association has created a number of task forces including those specifically aimed at Public Health and Prevention, Obesity Management, and Childhood Obesity. The overall goals of EASO revolve around enhancing the understanding and treatment of obesity in Europe; improving the quality of obesity education across Europe; developing a coherent approach to obesity
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management throughout Europe; forging European and global links between individuals and organizations concerned with the study of obesity; connecting active researchers from diverse disciplines who contribute to the development of a European perspective on obesity; and providing optimal input at the international level from a European perspective. In 1988, the EASO sponsored the first European Congress on Obesity (ECO), and since then, this annual meeting has been held in major cities throughout Europe. It routinely draws thousands of international delegates who meet to discuss the latest research and trends related to the study of obesity. As part of its mission, EASO also supports Young Investigators United (YIU) to facilitate the networking of young Europeans scientists and provide an arena for the exchange of ideas between leading experts and future leaders in the field. The YIU hold an annual meeting in conjunction with the EASO national conference. EASO sponsors a number of publications, including Obesity Reviews, a review journal that publishes papers from all disciplines related to the study of obesity. Obesity Reviews is designed to appeal to all professionals with an interest in obesity, such as endocrinologists, cardiologists, gastroenterologists, obstetricians, rheumatologists, and healthcare professionals working in general medicine or surgery. In addition, the Journal contributes to education and interprofessional development by publishing a variety of diverse opinions dealing with current controversies in the field. The International Journal of Obesity is a journal for clinicians and researchers working in obesity, diabetes and related disorders, dietetics, psychology, psychiatry, epidemiology, metabolic function, biochemistry, physiology, molecular biology, and genetics. In addition to periodicals, the Association regularly publishes various reports and position papers related to the study of obesity, including an annual survey on obesity throughout Europe. Related organizations include the United Kingdom Association for the Study of Obesity (ASO), the Hellenic Medical Association for the Study of Obesity (HMAO), the Netherlands Association for the Study of Obesity (NASO), and the Czech Society for the Study of Obesity (CSS). See Also: North American Association for the Study of
Obesity (NAASO); Obesity.
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European Food Safety Authority (EFSA)
Bibliography. European Association for the Study of
Obesity (EASO), www.easoobesity.org (cited September 2006); Hellenic Medical Association for the Study of Obesity, www.hmao.gr (cited September 2006); Aileen Robertson, ed., Food and Health in Europe: A New Basis for Action (World Health Organization, 2004); United Kingdom Association for the Study of Obesity, http://www.aso.org.uk (cited September 2006). Ben Wynne, PH.D Gainesville State College
European Food Safety Authority (EFSA) The European Food Safety Authority (EFSA) was created by a European Parliament and Council Regulation and adopted in January 2002. The regulation established the basic principles and requirements of food law and stipulated that EFSA would be an independent source of scientific advice, information, and risk communication in the area of food and food safety issues. The impetus for the creation of the Authority was a series of food scares in the late 1990s that undermined consumer confidence in the safety of food and of the ability of governmental authorities to adequately deal with the problem. Ultimately, this led the European Union institutions to conclude that there was a need to establish a new scientific body charged with providing independent and objective advice on food safety issues associated with the food chain. The administrative offices of the Authority moved from Brussels, Belgium, to Parma, Italy, in 2005. Four distinct bodies make up the EFSA: the Management Board, the Executive Director and staff, the Advisory Forum, and the Scientific Committee and Panels. The EFSA Management Board includes 14 members appointed from across the European Union and an additional representative from the European Commission. The Board’s primary responsibilities include implementing internal rules and regulations, drafting budgets and work programs, and in general ensuring that the EFSA functions efficiently. The Executive Director is the legal representative of the authority and is charged with handling daily
management responsibilities for all staff matters. The Advisory Forum is the EFSA’s consultative body. It advises the Executive Director on scientific matters and is an important forum for exchange on risk assessment and food safety issues. Numbering eight in total, the Scientific Committee and Panels are made up of independent scientific experts in various fields who are dedicated to providing the authority with the latest scientific information available related to food and food safety. Through the work of its Scientific Committees and Expert Panels, EFSA’s Department of Science provides risk assessment on all matters linked to food safety, including animal health and welfare and plant protection. The EFSA actively communicates with the public concerning its activities and recommendations. The Authority’s scientific opinions provide interested parties and the general public with objective, reliable, easily understood information through the dissemination of press releases, newsletters, and other communication tools designed to reach a broad audience. With a circulation of well over 10,000, the EFSAnews is the EFSA newsletter, which provides information relating to EFSA’s activities, ranging from its core scientific work to its corporate events, Web site developments, and publications. Editions of EFSAnews are available in several languages and in print or electronic versions. Each year, EFSA sponsors an annual meeting as an opportunity for industry, farming groups, consumer groups, and other non-governmental organizations such as those working on environmental issues to informally share knowledge and exchange views on food and food safety with EFSA staff. See Also: Food and Drug Administration (FDA); Food
Safety.
Bibliography. European Food Safety Authority, www.
efsa.europa.eu/en.html (cited September 2006); Food Safety from the Farm to the Fork, ec.europa.eu/food/food/biotechnology/index_en.htm (cited September 2006); Food Standards Agency, www.food.gov.uk (cited September 2006). Ben Wynne, PH.D Gainesville State College
European Public Health Association (EUPHA)
European Public Health Alliance (EPHA) The European Public Health Alliance (EPHA) was established in 1993 as an international nonprofit association registered in Belgium. The organization came into being amid concerns by a number of groups that while many European Union (EU) policies had an impact on public health, the EU at times did not directly recognize or address many of the public health issues involved. The Alliance hopes to promote and protect the health interests of all individuals living in Europe and to strengthen dialogue between EU institutions, the general public, and nongovernmental entities. The EPHA promotes the idea that the problems and concerns related to public health are international in character and therefore require solutions based on international cooperation. As a result, the EPHA supports an “open Europe” larger than the EU itself and enriched by the diversity and perspectives of an ever-expanding trans-European horizon. Among the specific goals of the organization include the introduction and implementation of policies that promote health in all areas of European policy; the promotion of the rights of all citizens to participate in decisions involving their own health and healthcare; ensuring cooperation among existing European organizations related to public health, health promotion, patient care, citizens rights and human rights; monitoring developments within the EU in the field of public health and providing a regular flow of information to and between members; influencing EU institutions and other relevant bodies in Europe and internationally to promote and evaluate effective public health policies: and seeking a greater role for public health and health promoting associations in the formulation and management of EU health policies. The EPHA operates on democratic principles and therefore facilitates communication and participation between and among member organizations and those EU institutions involved in policy development and program implementation. From year to year, the Alliance also aids many nongovernmental agencies in their advocacy work and in information dissemination, particularly in newer EU countries. Since its creation, the EPHA has grown dramatically in size and represents more than 100 organiza-
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tions with an interest in health issues. As a result, the Alliance has developed into a broad-based organization with a significant and growing influence on public policy. The EPHA’s membership consists of organizations, associations, and other groups at the local, regional, national or international level that in turn represent the interests of a broad, diverse cross section of society. There are two levels of membership. Full members are nongovernmental organizations that are active in the public health sector while associate members are other nonprofit organizations, professional bodies, academic institutions and local or regional authorities. The activities of the Alliance are governed by the Annual General Assembly, which convenes the membership once a year to discuss and evaluate policy. The Assembly elects an Executive Committee to oversee the overall day-to-day work of the organization and consultation and seminars are held with member organizations throughout the year as needed. The administrative offices of the EPHA are located in Brussels, Belgium. See Also: Healthcare, Europe; Global Health Council. Bibliography. European Public Health Alliance, www.
epha.org (cited September 2006); EU Business, www. eubusiness.com (cited September 2006); EUractiv.com, www.euractiv.com/en (cited September 2006); EUobserver.com, www.euobserver.com (September 2006); European Voice, www.european-voice.com (cited September 2006). Ben Wynne, PH.D Gainesville State College
European Public Health Association (EUPHA) Founded in 1992, the European Public Health Association (EUPHA) serves as an umbrella organization for health associations in Europe. It is an international, multidisciplinary scientific association that brings together more than 10,000 public health experts for professional exchange and collaboration. The organization includes almost 50 members and three associate members from 38 European countries and
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Evidence-Based Medicine
is governed by an elected Executive Council. The EUPHA’s mission revolves around being a proactive platform for public health professionals in research and practice and providing a medium to link theses concerned parties and policy-makers. The Association seeks to promote and strengthen public health research and practice in Europe; improve communication between researchers, practitioners, and policy-makers, provide a platform for the exchange of information, experience and research; and encourage and promote effective European joint research and other activities an the field of public health research and health services research in Europe. In accomplishing its mission and goals, the EUPHA has created specific sections to explore individual healthcare themes and bring together public health professionals working in the same or closely related fields. These sections are open to all EUPHA members, and among the themes are food nutrition, epidemiology, social security and health, child and adolescent health, public health practice and policy, migrant health, health services research, infectious disease control, utilization of medicines, and public health genetics. Each year, the EUPHA sponsors a number of meetings including a major national convention of researchers, practitioners, and policy-makers that focuses on the factors that cause diseases, disease control and cure, and the ongoing need to promote positive lifestyle changes for individuals. The International Scientific Research Committee of the EUPHA selects from hundreds of proposals those papers that will be presented and chooses topics for a wide variety of workshops. Since its inception, the Association has also worked with other groups to promote a wide rage of projects, programs, and initiatives. Along with the Open Society Institute (OSI), the EUPHA has established a major initiative for the support of public health associations as key links between governments, the scientific community, and the general population in central and eastern Europe. In addition, the Association regularly collaborates with the American Public Health Association (APHA), the Association of Schools of Public Health in the European Region (ASPHER), the European Health Management Association (EHMA), the International Union of Health Promotion and Education (IUHPE), the World Federation of Public Health Associations (WFPHA), and the World Health Orga-
nization/Regional Office for Europe (WHO/EURO). Six times a year, the EUPHA publishes the European Journal of Public Health, a peer-reviewed journal that includes original research articles and provides a forum for discussion and debate on current international health issues with a focus on Europe. See Also: Healthcare, Europe; European Public Health
Alliance (EPHA).
Bibliography. Association of Schools of Public Health
in the European Region, www.aspher.org (cited September 2006); Wilhelm Kirch, ed., Public Health in Europe (Springer, 2004); World Federation of Public Health Associations www.wfpha.org (cited September 2006); World Health Organization, The European Health Report 2005: Public Health Action for Healthier Children and Populations (World Health Organization, 2005); European Public Health Association, www.eupha.org (cited September 2006). Ben Wynne, PH.D Gainesville State College
Evidence-Based Medicine Evidence-based medicine (EBM) is a process clinicians can use to integrate current research and personal clinical expertise to make informed diagnostic, prognostic, therapeutic, and preventive decisions. At its ideal, EBM is a process of self-directed learning that provides clinicians with a lifelong method of updating clinical knowledge in a targeted, patient-centered fashion. The increasing organization and availability of up-to-date research on a broad range of topics makes EBM important and possible for all practitioners. Steps of EBM EBM processes can be broken down into five steps: 1) Formulate a question relevant to the elements found in the mnemonic PICO: patient, intervention, comparison, and outcome. 2) Identify the current best sources of reliable evidence. 3) Evaluate the evidence. 4) Apply evidence. 5) Evaluate performance.
Exercise for Children
Step one, formulating a focused clinical question, is critical, as the structure of the question guides the subsequent steps. The ideal question considers the elements of the mnemonic PICO: patient and the patient’s condition (P), describes the specific intervention (I), or more broadly, considers questions of etiology, diagnosis, treatment, prognosis, or cost-effectiveness, asks about comparison (C) intervention when appropriate, and considers the desired outcome (O). Step two is accomplished ideally through targeted search strategies in appropriate databases. The quantity of information has expanded, particularly with greater accessibility on the internet. Important sources of information directed at EBM include the Cochrane Library, the American College of Physicians Journal Club, and MEDLINE. The Cochrane Library is the product of an international collaboration between clinicians, consumers, and researchers whose primary purpose is to promulgate systematic reviews that serve as an authoritative summation of the medical literature on topics relevant to clinical practice. The American College of Physicians Club and the British Medical Journal serve as sources of up-to-date medical research. In step three, studies are evaluated according to two criteria, the first being “levels of evidence” that assign different levels of strength to research based on methodology and study design. This is determined by the type of question and by the rigor of the study design and subsequent statistical tests. The second criteria is importance of the evidence to the clinician’s specific question. In step four, the clinician evaluates the situation, his or her clinical knowledge, and patient preferences to integrate the evidence to answer the initial question. In step five, the clinician evaluates his or her ability to carry out these four steps to reflect on his or her performance. EBM in Developing Country Setting In a developing country setting, obstacles to implementing evidence-based medicine include unreliable access to information, including electronic repositories of information, may make implementation of EBM difficult. However, it has been suggested that inculcating healthcare workers with the skills and philosophy of EBM may improve not only medical practice but also the quality of evidence in these settings.
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SEE ALSO: Case-Control Study; Cohort Study; Random-
ized Control Trial.
Bibliography. Center for Evidence Based Medicine,
http://cebm.net/; Antonio Dans and Leonila Dans, “The Need and Means for Evidence-Based Medicine in Developing Countries,” Evidence Based Medicine (v.5, 2000); David Sackett, Evidence-Based Medicine: How to Practice and Teach EBM (Churchill Livingstone, 1988); Laura Zazowski, Christine Seibert, and Selma VanEyck, “Evidence-Based Medicine: Answering Questions of Diagnosis,” Clinical Medicine & Research (v.2/1, 2004). Constance W. Liu, M.D. Case Western Reserve University
Exercise for Children Exercise is a subcategory of physical activity (an umbrella term meaning any bodily movement produced by skeletal muscles that leads to anexpenditure of energy above the basal level, including work and leisure) that is planned, structured, repetitive, and aims to improve or maintain to a greater or lesser extent our physical fitness. It is well-known that physical exercise brings about many well known physical, psychological and social benefits to children. In comparison to adults and adolescents, exercise in children requires specific adjustments in terms of both type of exercise and load, requires an active involvement and supervision on behalf of parents, and most importantly, children should see it as a fun activity to do rather than an obligation. Health benefits of exercise Active children have higher levels of muscle and bone strength, a smaller risk of developing type 2 diabetes as well as a tendency toward lower blood pressure and cholesterol levels. Exercise also helps children develop social skills such as sharing, taking turns, cooperation, sense of belonging and learning about winning and losing. It also enhances physical skills like eye–hand coordination and ball skills. Furthermore, it may help foster stress coping strategies, as exercise may help children overcome difficulties with sleep, concentration, socializing, or with any emotional challenges of the daily routine,
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Exercise for Children the other hand, many children with anorexia nervosa also overexercise. Types of exercise The ideal type of exercise for children depends on the age group. Children are normally not ready for competitive sport until around age 8 or 9. Suitable activities for children under about 8 years include walking, cycling, kicking, throwing and hitting balls, using playgrounds, water activities, dancing, gymnastics, martial arts at a noncompetitive level, or taking pets for a walk or run.
Exercise for children has many benefits including improved health and fostering social skills.
such as running to catch a bus or studying for a test. It also makes them have a better outlook on life. On the other hand, developing regular exercising habits in children, in combination with healthy eating patterns is a good way to achieve weight control and to avoid becoming overweight and obese in this age group. Moreover, it should be noted that young children should avoid prolonged periods of inactivity (no more than one hour unless they’re sleeping or two hours in case of school-age children). Children are more likely to be motivated and stick to a certain type of exercise or sport if their families engage actively in that sort of activity and act as role models. The family should also not forget that, above all, exercise in children should be a fun activity. However, there is the danger of trespassing a threshold of healthy involvement when families become overinvolved and competitive and try to push their children into attaining goals and pursuing levels of exercise they are not ready or interested to pursue. Overexercising can cause similar effects to those of anorexia nervosa, such as weight loss, overuse injuries and hormonal imbalances like amenorrhoea. On
Amount of exercise The American Heart Association recommends that children age 2 and older undergo at least 30 minutes of enjoyable, moderate-intensity activities on a daily basis, as well as 30 minutes of vigourous physical activities at least three to four days each week to achieve a good level of cardiovascular fitness. A suitable alternative is to split those 30 minute periods into two 15- or three 10-minute periods during the day. The National Association for Sport and Physical Education (NASPE) states that for infants, there are no specific exercise requirements, and that exercise should encourage motor development. As for toddlers, it advocates one and a half hours of minimum daily activity, namely 30 minutes of planned physical activity and 60 minutes of unstructured physical activity (free play). As far as preschool children are concerned, it recommends two hours of minimum daily activity, including 60 minutes of planned physical activity and 60 minutes of unstructured physical activity. Finally, it calls for one hour or more broken up into bouts of 15 minutes or more. Even though children tend to spend a lot of time in sedentary activities such as television, computer games, the internet, and homework, time allocated to exercise should come at the expense of reducing these sedentary activities. ����������������� Even if children are involved in competitive sport, they need to be protected from injury. Thus, ������������������������������������� it is important to incorporate warm-up and cool-down exercises, as well as to wear protective gear such as knee pads or helmets. SEE ALSO: Exercise for Seniors; Exercise/Physical Fitness;
Sports Injuries.
Bibliography. National Association for Sport and Physi-
cal Education, www.aahperd.org/naspe/ (cited October
Exercise for Seniors
2006); U.S. Department of Health and Human Services, www.healthierus.gov/dietaryguidelines (cited September 2006); KidsHealth, www.kidshealth.org/parent/nutrition_ fit/fitness/exercise.html (cited September 2006). Tiago Villanueva Centro Hospitalar de Lisboa-zona central, Portugal Karim Khan Independent Scholar
Exercise for Seniors Exercise changes the body’s chemistry. Seniors benefit by improving quality of life, slowing the processes of deterioration, maintaining overall fitness leading to greater independence in later years. The long-term Harvard Nurses’ Health Study indicated specific benefits of mild-to-moderate exercise. Just getting moving is the first step. Including any activity to increase movement, from gardening to golf or dancing, allows a person to start expending energy, allows the muscles to work. Benefits from exercise include physical, psychological, and quality of life. Physical benefits include fewer fatal heart attacks, diminished risk for stroke, reduced risk for some cancers, and maintained bone density. Psychological benefits include the release of endorphins acting as antidepressants, decreased stress and improved coping skills, better mood, improved feeling of well-being, and better attitude. Quality-of-life benefits include increased energy and endurance, improved sleep, and better sexual function. Existing medical conditions are not an excuse to keep from exercising. Exercise can provide improvement. For arthritis, professionals recommend low impact, starting slow, and paying attention to the body’s signals like additional pain to stop. For those people with diabetes or diabetes risk factors, exercise improves the body’s ability to convert blood sugar to energy and has a stabilizing effect on blood sugar. While many professionals suggest 30 minutes of exercise every day is ideal, studies have shown that one to two hours every week provides some improvement. The important message is to get regular exercise. During middle age, muscles begin to shrink, and joints begin to stiffen with diminished joint flexibility.
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Building muscles creates strong muscles and bones, tones the muscle to do the work it is intended to do, supporting the body and providing strength to perform daily activities. The most effective muscle workout is to exercise major muscle groups. Allow the muscles to recuperate for 48 hours before repeating. Don’t do the same exercise every day; vary the routine to allow muscles the time needed to recover and to work different muscle groups. Using light weights, dumbbells, or resistance bands to work the eight major muscle groups needing attention include chest, back, abdominals, biceps, triceps, shoulder, buttocks, and hips and legs, improves muscle tone. Push ups, sit ups, and squats are all strength exercises and work by lifting the body’s own weight. Consulting a professional before beginning a weight program or performing the exercises under professional supervision decreases the risk of injury and improves the efficiency of the exercise. Stretching and Balance Aging adults experience slower reaction times and diminished sense of body position. Stretching and balance exercises improve the body’s ability to know when it is off balance and take action to remedy the situation. Stretching may reduce the risk of injuries from falls. Books, videos, and television programs provide a variety of stretching exercises designed for seniors; some can even be done while sitting. Pilates and the martial arts disciplines all involve stretching and bending. Seniors can find a stretching program suitable to their interest and abilities. Aerobic Exercise Continuous, uninterrupted, gentle exercise that encourages deep breathing but doesn’t allow the senior to get out of breath burns fat for energy, requires oxygen and engages heart and lungs increasing lung capacity, improving heart function. To get out of breath means the exercise is anaerobic and is burning glycogen instead fat as the main source of energy. The longer a person goes without exercising, fat burning enzymes diminish leading to fat deposits and being overweight. Aerobic exercise can be from mild to moderate to strenuous. Walking is an example of a mild aerobic exercise. Bicycling is an example of a moderate exercise. Running is an example of a strenuous or vigorous exercise. Seniors have numer-
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Exercise/Physical Fitness risk factors. Women at risk for osteoporosis and the potential of fractures from falls may find the most benefit from tai chi and strength training with resistance bands. Men at risk for heart disease may achieve better overall health benefit from aerobic exercise. Exercise should start slow and increase gradually. Include a five minute warm-up with stretching to help prevent injuries by supplying blood flow and oxygen to muscles. Wear protective gear appropriate to the sport, for example, helmets for biking; helmets, knee pads, elbow pads, and wrist protection for rollerblading. Take advantage of the professional assistance to make sure exercises are done with the proper form. Remember to do cool-down exercises after strenuous exercise to allow the heart rate to return to normal gradually, reduce lactic acid in the muscle tissue (lactic acid causes cramping, sore muscles, and pain), and prevent blood from pooling in the lower extremities. SEE ALSO: Gerontology.
Physical benefits for seniors include fewer fatal heart attacks, diminished risk for stroke, and maintained bone density.
ous aerobic exercises to choose from including dancing, swimming, rowing, cross-country skiing, skating, racket sports, and aerobic classes. Safety and Injury Prevention Sports injuries common to older exercisers are pulled muscles, torn ligaments and tendons, dislocated joints, and broken bones. To prevent these injuries, it is imperative to exercise within personal physical limits. Seniors beginning an exercise program should consult with their physician to determine their capabilities and limitations. Physicians may perform a stress test to see how much pressure the heart muscle can take and also the maximum heart rate and target heart rates during exercise. Sports literature provides a quick heart rate formula adjusted for age: 220 minus age equals the maximum heart rate and suggests working out at 65 to 80 percent of maximum heart rate will proved the aerobic zone. Keep in mind the formula is based on average and everyone is an individual with individual needs. A stress test will determine the individual maximum heart rate. They will also help the patient choose exercise option geared to the patient’s diagnosis and
Theodore Berland, Fitness for Life (American Association of Retired Persons, 1986); Edward L. Schneider, and Elizabeth Miles, Ageless Take Control of Your Age and Stay Youthful for Life (Rodale, 2003); C. Bree Johnston, William L. Lyons, and Kenneth E. Covinsky, “Geriatric Medicine” in Current Medical Diagnosis & Treatment 2004 (Lange, 2004). Bibliography.
Lyn Michaud Independent Scholar
Exercise/Physical Fitness Exercise is a means of combating one of the greatest dilemmas facing many developed countries. This issue is the consequences that arise from being overweight. This excess weight stresses our body’s systems. Additionally, when extra weight is present, quality of life also diminishes. Ultimately, many of us are not living to our full potential. Although this description sounds grim, the battle of the bulge can be won. All of us have the ability to fight back and win. There are two parts of the equation to fight this battle: diet and exercise. Essentially, a healthy diet includes eating in moderation a variety of good foods from the food pyramid.
The second part of the equation is exercise. Although diet is important to our health and well-being, we will focus on exercise. Good old-fashioned exercise, of just moving your body, is a part of the solution to either target excess weight or maintain a healthy weight. Exercise is not a bad word. Exercise or physical activity is as simple as the major shoe brand ad “Just Do It,” or is it? Yet if just doing physical activity is so easy, then why do the developed countries suffer from obesity? So “just doing it” must be more complex than what the shoe ad claims. Reasons to Exercise One of the main reasons is that cardiovascular disease is the number one killer in the United States. The American Heart Association (AHA) Web site lists 10 risk factors for cardiovascular disease: age, heredity, smoking, alcohol, high cholesterol, high blood pressure, excess weight, diabetes mellitus, stress, and lack of activity. Because we know that we are getting older and we cannot change our heredity, these risk factors will not be mentioned further. The remaining eight risk factors are controllable, meaning we can do something about them. Of these eight risk factors, let us focus on lack of activity. If we were to change lack of activity to physical activity, then how does that change the remaining seven risk factors? Physical activity is known to decrease high cholesterol. Specifically, low-density lipoprotein (LDL), which is considered the “bad” cholesterol, decreases; and high-density lipoprotein (HDL), which is the “good” cholesterol, increases. Exercise allows our body to use the HDL to help clean our blood vessels of the bad cholesterol. This change makes it easier for the heart to pump. Next, exercise causes a decrease in blood pressure. Exercise causes blood pressure to drop by strengthening the heart so that it can pump more efficiently while also improving the stretchiness of the blood vessels themselves. Physical activity also decreases weight. Not only does the actual physical activity burn calories, but continual exercise increases muscle mass. An increase in muscle mass allows the body to burn more calories at rest. The symptoms of diabetes mellitus are decreased or even completely eradicated as a result of physical activity. Many of the symptoms diabetics suffer from such as tingling/pain in the extremities and cuts healing slowly are a direct result of poor circulation. Again, exercise improves
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the heart’s ability to pump and the vessels’ ability to distribute the blood; therefore, the cells of the body, such as nerve cells or skin cells, get the necessary oxygen and nutrients from the blood that they need to function and repair themselves. Another major problem of diabetics is the ability of their cells to respond to insulin. Exercise directly improves the cells’ ability to respond to insulin. Last, physical activity decreases stress. Physical activity does not remove the stressors from your life, but it makes you feel more in control and focused, essentially better equipped to handle the stressors of life. Hence, by changing one risk factor, you have decreased or removed another five risk factors. Physical activity has other benefits as well. Increasing activity will also decrease the risk of certain types of cancer. Previous research has shown that regular exercise can decrease the risks of colorectal and lung cancer. Specifically important for men, exercise can also reduce the risk of prostate cancer. Additionally, the risks of getting breast and endometrial cancer are reduced by regular physical exercise. Beneficial to men, but of particular importance to older women, is the fact that activity increases bone density which decreases the risk of osteoporosis. Physical activity in children has the same benefits as it does in adults. When children exercise, it improves their cardiovascular system as well. Of note to the parents, children who are physically active sleep better. For parents of teenagers, physical activity helps with stress, especially during puberty. Puberty can be a very stressful and uncertain time for teenagers. Physical activity, again, helps teenagers cope with everyday stresses and helps build their self-esteem. Both of these points are crucial during puberty. Maintaining an active lifestyle during pregnancy helps decrease the discomforts of expectant mothers. We now know that maintaining and even starting (under the guidance of a physician) an exercise regime during pregnancy is safe and beneficial to the mother and baby. Exercise during pregnancy helps a woman maintain agility so she can continue with her everyday activities throughout the pregnancy. Exercise also decreases the pains associated with pregnancy. Exercise also improves her self-esteem. Additionally, labor and delivery times decrease. For the elderly, activity slows down the aging process. For people of any age, exercise gives you more confidence and improves your self-esteem. An-
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other important benefit of physical activity is energy. For those who feel exhausted and tired all the time, exercise helps. Although exercise cannot make up for a lack of sleep, it does give you an energy boost. In this way, it is true that exercise is a paradox; if you want energy, then you need to use energy. If you use your energy being physically active, then you will gain more energy from it. Exercise is great for the body and can be done at any age and stage of life. Reasons for not exercising Besides, these numerous benefits of exercise, most people still do not do it. To really get people moving, we need to truly understand why we are not active. The five main reasons people do not exercise are embarrassment, unable to exercise vigorously, do not enjoy it, lack of time, and money. Whether you have an extra 15 pounds or 150 pounds or more, most people who need to lose weight (and from the figures, statistical and otherwise, this is most people), we feel insecure about exposing our skin and fat. Most people have a “fear” of being seen wearing shorts and a T-shirt. Then mentioning the idea of going to a public place (i.e., around your block or a gym) in shorts, most people will not do it even if their doctor tells them they must for health reasons. Now, besides being overweight and embarrassed by being seen exposed in shorts and a T-shirt, we have to try to figure out how to use all of these new machines which look like some ancient torture devices—it’s no wonder many people cannot break out of the “fat mold.” For most people, the embarrassment factor is too great for them to overcome. Additionally, many people do not begin exercise because they are unable to move. For people so overweight that they have lost mobility, it is not only embarrassing but physically difficult to move their body. For these individuals, the idea of exercising vigorously is not possible. Another reason most people are not physically active is because they simply do not enjoy exercise. For many people, walking on a treadmill, for example, is extremely boring. Even if a physician tells you to exercise, if you do not enjoy it, why would you start doing it and keep doing it. Simply put, most people do not voluntarily do something for 30 or more minutes, three or more times per week if they find it boring. Despite our many technological advances to help us save time, it is a real challenge to
find the time to exercise. People, in general, work at least eight hours a day, then have numerous activities they or their families are involved in which occupy all of their time. People are so busy with work, clubs, committees, and driving their children to sports that they cannot find time to be physically active. Last, many people do not exercise because of the additional expense. In order to lose weight, many people will join a gym or fitness center which is very costly. Especially for people with middle- to lower-class incomes who need to lose weight, they cannot justify the cost of gym membership for their health. There are many valid areas that need to be addressed to get people moving and to keep them active for years to come. Getting Started To address these issues and to get people moving, remember to CARE. This acronym stands for Commit, Accountable, Realistic, and Excite. First of all, we need to commit today. We need to first commit to doing 10 minutes of activity three times every week. This can be done by making an appointment either mentally in your daily schedule or physically
Exercise is a part of the solution to either target excess weight or maintain a healthy weight.
write it in your day planner. The first step affirms a commitment to living healthier. Next, it is crucial to be accountable to someone to keep this appointment. If someone is a disciplined person, then once he or she makes an appointment or plan, he or she will follow through no matter what. Many people are not this disciplined; therefore, it is crucial to enlist a friend, coworker, boyfriend/girlfriend, or husband/ wife. Be honest to determine the type of accountability needed. Once accountability is established to help achieve the task of maintaining physical activity, then set a goal and a starting point. The goal and starting point must be realistic. Depending on a person’s initial fitness level, the starting point may be to walk the length of the house or apartment three times for three days. The physical activity does not need to start at a vigorous pace for the beginner; this is something that can be changed later. If this is the case, then the first goal would be to be active 10 minutes a day for three days of the week. Once this goal is achieved, then the next goal would be 30 minutes of activity for three times per week. If possible, continue to add time until the activity lasts for 40 minutes, and then add days of activity with six days being the maximum. During this process of adding time or days, changing the intensity level, or how hard you work, is a great way to improve health. Next, and one of the most important points, is experiment with what is exciting. People will continue to be active if they enjoy what they are doing! To find what is exciting, the key is experiment with different types of aerobic activities: biking (outside or stationary), hiking, rowing, swimming, aerobics classes (step aerobics, jazzercise, tae bo, etc.), walking (outside or on a treadmill), or a strength training circuit. The local public library is a valuable source of exercise videos that can be checked out for free. This resource will help people experiment with what is exciting and can be done at home to avoid feeling embarrassed. Because these videos are free at the public library, the cost of beginning an exercise regime is just time. Last, add an S to the acronym CARE to get CARES. One of the most important principles is “something is better than nothing.” Based on the physics principle of inertia (objects in motion tend to stay in motion and objects at rest tend to stay at rest), the most difficult part of exercising is starting. So, get up
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and do something today. After starting the first day, it will get easier every time thereafter. Because he or she CARES, we will start moving today. Exercise Prescription Now that we know what needs to be done to get started, what is the ultimate goal suggested by the AHA for decreasing cardiovascular risk factors. The AHA suggests 30 to 40 minutes of vigorous physical activity three to six times per week. However, this can be spread throughout the day into three 10-minute sessions, for example. Remember, most people will not start at this level, but this may be a long-term goal to achieve after months or years. The AHA states that even walking at a slow pace for one hour per week reduces the risks of cardiovascular disease for women in half. Additionally, the AHA’s Web site suggests a strength and flexibility component. To reiterate, the strength component of an exercise program helps build muscle mass which will increase the calories burned at rest. The flexibility component of exercise helps prevent injury to the joints during exercise and during normal daily activities. This exercise “prescription” is to decrease the cardiovascular risk factors. A person’s initial fitness level will determine the intensity of the activity. The harder the intensity of exercise will cause the cardiovascular system to work harder, thus increasing the heart rate. Therefore, the intensity of exercise can be determined by heart rate (HR). To determine if the exercise is at the intensity of choice, one must calculate target HR. Target HR is just that— the pulse (or heart rate) that one aims to reach during the physical activity. There are numerous ways to determine HR; below are two different formulas: [(HRmax – HRrest) X % intensity] + HRrest (HRmax – Adjuster) + 5 bpm To determine HRmax, one of the following formulas can be used. Target HR will vary slightly depending on the formula used, but this will be a good start. To find HRrest, take a pulse for one minute first thing in the morning (waking up without an alarm clock) while still in bed. This is done by placing your index and middle finger gently on the inside of the wrist (thumb side). A general guide for intensity level is low/light 50 to 60 percent, medium 60 to 70 percent, hard/high 70 to 80 percent, and elite >80 percent. For the equation, move
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the decimal point after the 0 over two spots to the left (i.e., 50 percent becomes 0.50). A quick check on intensity that does not involve math is the “talk test.” The intensity is too easy if a person can talk easily. Conversely, the intensity is too hard if a conversation is not possible. By using these principles, a person can determine if he or she is exercising at an appropriate level. Determining target HR is important for knowing the level of intensity of exercise. However, even if the level of intensity is light, the ultimate goal to achieve numerous health benefits is 30 minutes a day, three times per week. This goal can be achieved by Committing, being Accountable, setting Realistic goals, experimenting with what is Exciting, and by doing Something. While working toward this goal, do something exciting at a comfortable pace and place. Ultimately, these changes will decrease the cardiovascular risk factors. Decreasing these risk factors enables the cardiovascular system to function more effectively and for the rest of the body to feel good. SEE ALSO: Exercise for Children; Exercise for Seniors. Bibliography. Peter Brukner, Karim Khan, and John
Kron, The Encyclopedia of Exercise, Sport and Health (Allen & Unwin, 2004); Frank J. Cerny and Harold W. Burton, Exercise Physiology for Health Care Professionals (Human Kinetics, 2001).
Linda May Kansas City University of Medicine and Biosciences
Exercise Treadmill Test An exercise treadmill test (ETT) is an real-time evaluation of the heart while under cardiovascular stress. A primary care provider or well-trained professional performs ETTs in the outpatient setting. The testing is performed with a treadmill or bicycle and the heart’s electrical activity (electrocardiogram, EKG), blood pressure, heart rate, and pain levels are measured. Individuals undergoing this exam have typically exhibited unclear chest discomfort or signs of myocardial ischemia and have significant risk factors for coronary artery disease (CAD). The ETT aims to
reproduce any chest discomfort or electrical changes in the heart for an evaluation of worsening disease. ETTs are most beneficial in symptomatic men, older than 45 years old with risk factors for CAD, and are least predictive of disease in women, and individuals less than 35 years old. Although there are numerous acceptable protocols to complete an ETT, the overall goal remains consistent. The intensity of the treadmill increases until the patient reaches approximately 85 percent of his or her predicted maximum heart rate for his or her age group. If any type of pain occurs prior to reaching this goal, the testing may be terminated early. Interpretation of ETTs involve monitoring the EKG, heart rate, and blood pressure values for changes indicative of worsening ischemia, decreased exercise capacity, or arrhythmias. Following the results, a clinician may determine that this patient is a candidate for angioplasty, a procedure involving the unblocking of the heart’s coronary arteries. ETT is relatively safe, but as myocardial infarctions occur in 1 of 2,500 tests, clinical discretion of which patients are most appropriate for testing is imperative. Patients with cardiac arrhythmias, electrical conduction blocks, a recent heart attack, or uncontrolled heart failure represent absolute contraindications. Patients who are overly obese, have difficulty walking, have significant pulmonary disease, or have central nervous system disorders may have limitations preventing testing completion; thus, other testing modalities may need to be performed. ETT can be combined with further imaging including ultrasound (echocardiography), to visualize the heart’s wall motion, or with nuclear imaging to measure heart muscle perfusion. SEE ALSO: American Heart Association (AHA); Cardi-
ologist; Coronary Disease; Heart Attack; Heart Diseases (General); Heart Disease—Prevention. “ACC/AHA 2002 Guideline Update for Exercise Testing,” www.americanheart.org (cited July 2002); Sharonne N. Hayes and Patrick McBride, “Diagnosing Coronary Heart Disease: When to Use Stress Imaging Studies,” The Journal of Family Practice (v.52/7, 2003). Bibliography.
Stephanie F. Ingram University of South Florida College of Medicine
Eye Cancer
Extragonadal Germ Cell Tumor Extragonadal germ cell tumor (EGCT) originates from developing cancerous sperm or egg cells traveling from gonads to other parts of the body. The term extragonadal means outside of the gonads (reproductive organs). Germ cells refer to the reproductive cells such as the sperms and the eggs which are initially located in the yolk sac outside of the embryo. During development, the germ cells migrate to the embryo into the pelvis to become ovarian cells or into the scrotal sac as testicular cells. EGCT develops when these germ cells migrate to other parts of the body and begin to grow. EGCTs are rare among germ cell tumors and can be either benign (noncancerous) or malignant (cancerous). Benign EGCTs are called benign teratomas, which are often large and more common than malignant EGCTs. The great majority of these tumors is benign and can be treated with surgery alone; most of these benign tumors occur in children. Although benign tumors do not spread, they may cause other problems such as pressing on nearby organs. On the other hand, malignant EGCTs can be divided into two types: nonseminoma (e.g., embryonal carcinoma, yolk sac tumor, and mixed germ cell tumors) and seminoma (or germinoma in females). Although they are much more common in males with the malignant form, extragonadal tumors can also occur in females with equal frequency as in males for the benign type. Nonseminomas tend to grow and spread more quickly than seminomas. As a result, they usually are large and cause symptoms. If untreated, malignant EGCTs may metastasize to the lungs, lymph nodes, bones, liver, or other parts of the body. EGCTs can be diagnosed via a variety of tests and investigations such as biopsy (removing a sample of tumor for examination under microscope), complete blood count and other blood tests, and medical imaging such as computed tomography (CT) scan, magnetic resonance imaging (MRI), X-ray, and ultrasound. In addition, EGCTs often produce proteins, sometimes known as tumor markers, that can be measured from the blood. These markers are alpha-fetoprotein (AFP) and human chorionic gonadotrophin (HCG), and their levels are checked in the diagnosis of EGCT as well as monitored throughout treatment.
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There are different treatments available for EGCT patients and several factors need to be considered when designing a treatment plan: whether the tumor is nonseminoma or seminoma, size and location of the tumor, levels of tumor markers in the blood, extent of metastasis, initial response to treatment, and recurrence. Typically, patients with nonseminoma EGCTcarrying tumor in the back of the abdomen with slightly higher tumor marker levels in the blood and no spread of tumor to other organs are given good prognosis. In contrast, patients with nonseminoma EGCT-carrying tumor in the chest with high level of tumor markers and metastasis of tumor cells to organs other than the lungs have poor prognosis. There are three standard treatments available: radiation therapy, chemotherapy, and surgery. For seminoma, treatments often involve radiation therapy for small tumors in one area. Chemotherapy is administered if the tumors are larger or have spread, and surgery might be required if there is large tumor remaining after chemotherapy. For nonseminoma, chemotherapy followed by surgery is often performed to remove any remaining tumor. SEE ALSO: Cancer; Chemotherapy; Chemoradiotherapy;
Childhood Cancers; Liver Cancer; Lung Cancer.
Bibliography. Mark H. Beers, Robert S. Porter, and
Thomas V. Jones, eds., The Merck Manual of Diagnosis and Therapy, 18th ed. (Merck Research Laboratories, 2006); Raymond E. Lenhard Jr., Robert T. Osteen, and Ted Gansler, eds., Clinical Oncology (American Cancer Society, 2001). Stephen Chen University of Toronto
Eye Cancer The eye is anatomically complex. It has three major parts: the globe, the orbit, and the adnexal structures. From anterior to posterior, the globe contains the cornea, the uvea, the lens, and the retina. The uvea is comprised of the choroid, the iris, and the ciliary body. Cancers that affect the globe, or eyeball, are called intraocular (within the eye) cancers. The orbit consists of the tissues surrounding the globe. This includes the extraocular muscles that are responsible
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for moving the globe and the nerves attached to the eye. Cancers affecting these tissues are referred to as orbital cancers. The adnexal (or accessory) structures include the eyelids and tear glands. Cancers in this area are called adnexal cancers. Intraocular Cancers Intraocular cancers can be either primary or secondary. Secondary intraocular cancers are cancers that have spread to the eye from another part of the body. Breast and lung cancers are among the most common cancers to spread to the eye, usually to the uvea. In contrast, primary cancers originate inside the globe. Melanoma is the most common primary intraocular cancer in adults, followed by lymphoma. Melanomas of the eye are classified as anterior when arising in the iris and posterior when arising in the choroid or ciliary body. Ninety percent of intraocular melanomas are posterior choroidal, with nearly the remaining 10 percent being melanomas of the iris. Posterior choroidal melanoma arises from melanocytes in the choroid. The incidence in the United States is approximately six cases per 1 million and is highest around age 55, although this figure varies in regions with more or less sun exposure. Choroidal melanoma commonly results in partial or complete visual loss in the affected eye due to either tumor destruction of ocular tissues or as a consequence of treatment. It is associated with a mortality rate of 30 to 50 percent within 10 years, owing to its highly metastatic nature. There is currently no effective treatment for intraocular melanomas, although enucleation (removal of the eye while sparing orbital contents) and irradiation are potentially life saving. Primary intraocular lymphoma is the next most common intraocular malignancy in adults but remains exceedingly rare. An intraocular lymphoma is considered extranodal and is always of the non-Hodgkin type (as opposed to Hodgkin’s lymphoma). The elderly and patients with human immunodeficiency virus (HIV)/AIDS have a propensity for this cancer, likely due to their immunocompromised state. Over 80 percent of patients develop cerebral involvement, which is associated with a much poorer prognosis. Randomized treatment trials are scarce owing to the rarity of this cancer, but case reports support external beam radiation as an effective treatment. In children, retinoblastoma is the most common primary intraocular cancer, followed by medulloepi-
thelioma. Retinoblastoma is a tumor of the retinal photoreceptor precursor cells. It occurs due to mutations in the RB1-gene, although only 5 percent of patients who develop the disease have a positive family history. It has an incidence of approximately 11 per 1 million children worldwide. It occurs mostly in children younger than 5 and accounts for three percent of all neoplasms in children under 15. Retinoblastoma can be unilateral or bilateral and is usually first detected by leukocoria (a white papillary reflex replaces the normal red-light reflex). Visual disturbances are often noted because of the intrinsic retinal involvement of this cancer. Management varies per patient and includes radiation, neoadjuvant chemotherapy, and surgery. The most important prognostic factor remains early detection, resulting in survival rates of approximately 86 to 92 percent. Extraocular extension through the sclera or along the optic nerve is associated with higher mortality. Unfortunately, highly advanced cases of retinoblastoma are still seen in the developing world. This can be attributed to neglect, poverty, cultural beliefs, politics, health-seeking behavior, and so forth. Orbital and Adnexal Cancers Cancers of the orbit and adnexa are not unique to the eye. They develop from muscle tissue, nerve fibers, and skin, similar to neoplasms found elsewhere in the body. The most common orbital malignancy in adults is a cavernous hemangioma, representing 4.3 percent of all orbital neoplasms. Cavernous hemangioma is a benign, slow-growing, highly vascular lesion. It presents as a painless, unilateral, progressively proptotic eye. Unless visual acuity or field loss is appreciated, conservative management is all that is recommended. The tumor has a predilection for the intraconal space (between the optic nerve and the extraocular muscles); as a result, complications such as compressive optic neuropathy and mortality from intraoperative bleeding can occur. Novel surgical and laser techniques for the management of cavernous hemangiomas are being investigated. A lymphoid tumor is the second most common orbital tumor in adults. Orbital lymphoma is a painless, slow-progressing malignant neoplasm. A past medical history of non-Hodgkin’s lymphoma is common. Patients note extraocular motility problems and proptosis as the initial symptoms. The tumor can be diagnosed by biopsy and is managed with focal ra-
diation. Chemotherapy is reserved for those patients with systemic involvement. The most common orbital tumors in children are capilliary hemangioma, dermoid cyst, and rhabdomyosarcoma. Capilliary hemangioma is a benign vascular lesion that manifests at birth or by 6 months of age. It is characterized as a rapidly enlarging red spongy mass that usually appears in the upper eyelids. The growth phase is normally followed by spontaneous regression beginning at 1 year and is 75 percent complete by 7 years. Due to its size, capilliary hemangiomas have been associated with refractive error and possible ambylopia. There is also a rare association with Kasabach-Merritt syndrome, where platelets are entrapped within a large capilliary hemangioma, causing thrombocytopenia (low platelets) and bleeding diathesis. The most accepted treatment modality is to administer slow and careful intralesion steroid injections. An orbital dermoid cyst is also a benign orbital tumor. It is an example of a choristoma—a tumor that originates from aberrant primordial tissue. They are most commonly found at the junction of cranial sutures, specifically the frontozygomatic suture. Orbital dermoid cysts can grow large enough to displace the globe and compress the extraocular muscles and optic nerve, leading to diplopia and vision loss. Malignant orbital tumors can occur in childhood, the most common being rhabdomyosarcoma. Rhabdomyosarcoma is a cancer of striated muscle origin. Approximately 9 percent of all rhabdomyosarcomas occur in the orbit, with a predilection for the superior nasal orbit. The average age of onset is about 6 years, with a male-to-female ratio of 1.5:1. These tumors grow very rapidly and may infiltrate bone and adjacent tissues and produce marked proptosis. Prognosis is more favorable for orbital rhabdomyosarcoma than for rhabdomyosarcoma elsewhere in the body; however, management remains complex. A biopsy is required for diagnosis, but surgical excision of the tumor is usually limited due to its infiltrative nature. Radiation and chemotherapy comprise the initial treatment regimen. The most common adnexal tumor is basal cell carcinoma (BCC), followed by squamous cell carcinoma (SCC), melanoma, and sebaceous carcinoma, all involving the eyelid. BCC is described as having a waxy, pearly appearance with a crater-like depression. The tumor is slow growing and is usually secondary to ul-
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traviolet (UV) light exposure. Over 60 percent occur in the lower lid. The tumor rarely metastasizes, but excision with appropriate margins and lid reconstruction is recommended. SCC typically appears as a red, scaly patch with ulceration, crusting, and central keratinization. It is more aggressive than BCC and has been associated with UV light exposure or hereditary diseases such as xeroderma pigmentosa. Unlike BCC, SCC metastasizes often, spreading to the orbit, sinuses, and lacrimal system via direct extension or along nerve sheaths, lymph channels, and blood vessels to more distant sites. It is associated with a mortality of 0 to 30 percent, making early surgical excision with a frozen pathological specimen crucial. Exenteration is necessary when SCC invades the orbita. Melanoma of the eyelid is a different entity than the previously discussed intraocular melanoma. It is most common in elderly whites and represents 1 percent of all lid tumors. Missing eyelashes near a suspicious lesion is a common clinical finding. Over 40 percent of melanomas in the eyelid are amelanotic, making a biopsy warranted when clinical suspicion exists. The depth of invasion is used to stage this highly metastatic tumor; it will also guide the extent of surgical excision required. Cryotherapy should never be used for the treatment of melanoma. Sebaceous carcinoma is one of the most lethal eyelid tumors. Lymph node metastasis occurs in 17 to 23 percent of the cases. The mortality rate increases to 76 percent when orbital extension occurs (6 to 16 percent of the time). Clinically, these tumors have a higher incidence in Asians. They manifest as a painless or irritating enlarging mass, with patients often presenting with a history of recurrent chalazion refractory to treatment. Diagnosis requires properly prepared tissues with a special oil-red O stain. The management of sebaceous carcinoma is multidisciplinary and physicians familiar with this malignancy should be consulted. In addition, wide surgical excision with radical neck dissection and possible radiation is recommended. SEE ALSO: Eye Care; Eye Diseases (General). Bibliography. J. A. Borden, “Treatment of Tumors In-
volving the Optic Nerves and Chiasm,” Ophthalmology (v.17/1, 2002); D. Bouvier and C. V. Raghuveer, “Aspiration Cytology of Metastatic Chordoma to the Orbit,” American Journal of Ophthalmology (v.131/2, 2001); “Cavernous Hemangioma,” http://www.emedicine.com/oph/topic216.
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htm (cited May 14, 2007); S. J. Chawda and I. F. Moseley, “Computed Tomography of Orbital Dermoids: A 20-Year Review,” Clinical Radiology (v. 54/12, 1999); “Collaborative Ocular Melanoma Study Report no. 10: The Collaborative Ocular Melanoma Study (COMS) Randomized Trial of Pre-enucleation Radiation of Large Choroidal Melanoma II: Initial Mortality Findings,” American Journal of Ophthalmology (v.125/6, 1998); J. J. Dutton, “Clinical and Surgical Orbital Anatomy,” Ophthalmology Clinics of North America (v.9/4, 1996); R. C. Eagle, Eye Pathology: An Atlas and Basic Text (Saunders, 1999). Jared Daniel Ament, M.D., M.P.H. Harvard Medical School Harvard School of Public Health
Eye Care Eye care is a global health issue that holds significant impact on people’s lives, yet it has the potential for vast improvement given the proper resources and commitment. While the most common eye care problems are low visual acuity and disorders such as cataract, glaucoma, and diabetic retinopathy, several other issues such as ocular infections and childhood blindness also need to be addressed. As with many global health problems, there is a strong link between poor eye health and poverty or lack of education. While encouraging measures such as Vision 2020 are significantly improving eye health, much more still needs to be done to address this critical, yet relatively easily, health issue. Major Eye Care Problems It is estimated that there are 259 million people with visual impairment worldwide, including people with refractive error. Of this number, 42 million people are blind, while 217 million have less severe visual impairment. Uncorrected refractive error from problems such as myopia (nearsightedness) or hyperopia (farsightedness) is the major cause of visual impairment worldwide, but can be addressed through measures as simple as prescription eyeglasses. Aside from refractive error, several common eye disorders significantly contribute to visual impairment. Cataract is responsible for approximately half of all blindness worldwide; fortunately, surgery and im-
plantation of a synthetic lens can correct the problem and restore proper visual function to millions. Much of blindness is caused by chronic disorders such as glaucoma (12 percent), diabetic retinopathy (5 percent), and age-related macular degeneration (9 percent), all of which progress slowly and thus difficult to notice. Because these disorders damage nerve cells of the retina, their detrimental effects on vision are largely irreversible. Infectious eye diseases such as trachoma (4 percent) and onchocerciasis (1 percent) used to be major causes of blindness but are now more controlled thanks to coordinated international efforts by the World Health Organization (WHO) and partners. Childhood blindness due to disorders such as amblyopia and congenital (birth) defects affects 1.4 million children worldwide and comprises nearly 4 percent of worldwide blindness. However, because nearly half these cases can be prevented or treated through known measures, there is huge potential for improvement in this area. Visual impairment undoubtedly harms people’s lives through many ways, the most obvious of which is loss of productivity. Even when taking into account the success of the Vision 2020 initiative, unaccommodated blindness alone is responsible for a $44 billion productivity loss every year. The blind and visually impaired face much greater susceptibility to accidents and death, especially in the poorest of nations. Stigma, isolation, and inability to lead normal lives are unquantifiable, yet significant, detriments to quality of life. Risk Factors There is an undeniable link between poverty and poor eye care. Over 90 percent of the world’s blind live in developing countries. Africa is home to 18 percent of the world’s blind, while southeast Asia and the western Pacific region are home to 32 percent and 25 percent of global blindness, respectively. Old age is the biggest risk factor for visual impairment; over 82 percent of the world’s blind are over age 50. With current trends of increasing longevity, the prevalence of age-associated disorders such as cataract, glaucoma, diabetic retinopathy, and age-related macular degeneration is expected to increase even more in coming years. Social and environmental conditions such as malnutrition, poor hygiene or sanitation, lack of access to early treatment, and lack of knowledge regarding eye care are all major contributors to blindness and visual impairment.
Measures to Improve Eye Care In recent years, measures have been taken to improve global eye health. The most significant of these is the Global Initiative for the Elimination of Avoidable Blindness, or Vision 2020—the Right to Sight. This partnership between the WHO and the International Agency for the Prevention of Blindness began in 1999 and aims to eliminate the causes of preventable blindness by the year 2020. Furthermore, Vision 2020 hopes to prevent the projected doubling of worldwide cases of unavoidable visual impairment between 1999 and 2020. In 2006, a monitoring committee evaluated the progress of Vision 2020 and concluded that while the program was lessening increases in blindness and was lowering cases of avoidable blindness worldwide, significant further action was needed in order to meet the program goals. Recommendations included providing more financial resources for the program, contributing to the underlying problems of socioeconomic stagnation and lack of health awareness, increasing the quality and quantity of human resources through more training, addressing glaring inequities of health access in rural or underserved areas, improving infrastructure and supply storage and delivery, encouraging formation of national-level programs to address eye care, and strengthening coordination among all the partners involved in Vision 2020. The encouraging feature of global eye care is how certain inexpensive, easily delivered treatments can lead to profound improvement in the lives of millions. In the 1970s, the WHO led an international movement to eliminate xerophthalmia (night blindness) caused by vitamin A deficiency. Simple measures such as the administration of oral drops and dietary supplements were sufficient to cure the disorder. Today, with around 70 nations actively addressing the problem, xerophthalmia is no longer the widespread, debilitating cause of blindness that it once was. When cataract surgery first became widespread, most poor patients could not afford intraocular lens implantation and were forced to use thick glasses in order to see again. The introduction of increasingly efficient cataract operations and inexpensive intraocular lenses now restores normal sight to millions of cataract patients within days after surgery. Much more needs to be done to improve eye care. Such measures will undoubtedly need to address basic health issues such
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as poverty, hygiene, awareness, and access to timely care. However, given the proper investment, coordination, and dedication, the prospects for systemic improvement in eye care may indeed look hopeful. SEE ALSO: Amblyopia; Cataract; Cornea and Corneal Dis-
ease; Eye Diseases (General); National Eye Institute (NEI); Optometrist; Ophthalmologist; Ophthalmology.
Bibliography. Lalit Dandona and Rakhi Dandona,
“What Is the Global Burden of Visual Impairment?” BMC Medicine (v.4, 2006); A. Foster and S. Resnikoff, “The Impact of Vision 2020 on Global Blindness,” Eye (v.19 , 2005); Kevin D. Frick, “The Magnitude and Cost of Global Blindness: An Increasing Cost that Can Be Alleviated,” American Journal of Ophthalmology (v.135/4, 2003). Nakul Shekhawat Vanderbilt University
Eye Diseases (General) There are a variety of ocular diseases and pathology that may affect a person’s vision. Some common eye diseases and conditions are reviewed here. Refractive Error People with emmetropic vision have no refractive error. In these patients, the cornea, which provides twothirds of refractive power, and the lens, which provides the remaining one-third of refractive power, perfectly focus an image on the retina. By contrast, people with ametropic vision require corrective lenses in order for the image to be in proper focus. Color Blindness Color blindness is usually an X-linked recessive condition affecting retinal photoreceptors that affects about 10 percent of the male population. There are several forms of color blindness, ranging for asymptomatic types to the most common type where the patient may confuse red with green. Cone dystrophy can also induce diminished color vision. Physicians commonly use the Ishihara or Hardy-Rand-Rittler pseudoisochromatic color vision plates to assess color vision of each eye individually.
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Diplopia Diplopia, or double vision, can be divided into two subtypes—monocular or binocular—and can be intermittent or constant. In monocular diplopia, patients have double vision when closing one eye. In binocular diplopia, patients have double vision only with both eyes open, and closing one eye causes the double vision to disappear. Some causes of monocular diplopia include corneal irregularities, astigmatism, cataracts, and refractive error. A common cause of binocular diplopia is strabismus (misalignment of the eyes) or neuromuscular disorders. Common Disorders of the Eyelids A hordeolum, commonly referred to as a sty, is an infection of the hair follicles or meibomian glands, usually due to Staphylococcus aureus. A chalazion is a chronic, granulomatous inflammation of a meibomian gland, which unlike a hordeolum, does not have acute inflammatory signs. Treatment consists of warm compresses and antibiotic ointment, and surgical drainage and excision if unresponsive to medical treatment. Blepharitis, or inflammation of the eyelid margin, is a very common condition that can be subdivided into anterior and posterior blepharitis. Patients with blepharitis usually have symptoms of burning, itching, redness, and tearing. Anterior blepharitis can be further subdivided into staphylococcal or seborrheic blepharitis. Usually, both types of blepharitis are present. Posterior blepharitis is usually secondary to meibomian gland dysfunction, and patients may have frothy or greasy tears. A xanthelasma is a common lesion that affects the upper eyelid more often that the lower eyelid. This lesion, while sometimes associated with elevated lipids, can also be found in patients with normal serum lipids. Dry Eye Syndrome In patients with dry eye syndrome, they may have a foreign body sensation with sandy, scratchy, burning, or red eyes. Some of the many causes of dry eye syndrome include hypofunction of the lacrimal gland due to congenital, acquired, infectious, traumatic, or medication-induced causes; mucin deficiency due to chemical burns, medications, chronic conjunctivitis, and Stevens-Johnson syndrome; lipid deficiency due to blepharitis; or defective spreading of the tear film secondary to eyelid abnormalities, lagophthalmos, proptosis, or conjunctival abnormalities. Some diag-
nostic measures include Schirmer test and assessing tear film breakup time with a slit-lamp examination. Fluorescein staining and slit-lamp examination will show the corneal irregularities present. Other conditions that can cause foreign body sensation include corneal abrasions, trichiasis (this occurs when eyelashes grow in the wrong direction, touching the conjunctiva), and corneal foreign bodies. Conjunctivitis Conjunctivitis, also referred to as pink-eye, is a common condition that prompts patients to see their physician. Conjunctivitis can be allergic in nature, and can also be caused by many different bacterial and viral infections. The infection can induce redness, tearing, itching, and discharge. While allergic conjunctivitis almost always causes itching, infectious conjunctivitis usually induces discharge. Viral conjunctivitis is more common than bacterial conjunctivitis, and of the viral cases, adenovirus is the most predominant. Patients with conjunctivitis must remember to frequently wash their hands and avoid rubbing their eyes. Treatment is determined by the etiology. Cataracts A cataract is a clouding of the natural lens of the eye. People with cataracts usually experience glare or halos, and symptoms are worse at night. Cataracts can be caused by multiple factors, including normal aging, trauma, or congenital syndromes. People who use chronic steroids are predisposed to both cataract formation and glaucoma. Cataracts are commonly divided into nuclear sclerosis, cortical cataracts, and posterior subcapsular cataracts. All forms of cataracts that are visually significant can be treated with surgery. Surgical correction entails removing the cataract in its entirety and replacing it with a silicone or acrylic lens implant. This lens implant then functions to allow the eye to focus and see clearly after cataract extraction. Patients may or may not need glasses after surgery to maximize their visual potential. Technological advances in the treatment of cataracts has made this one of the most common and successful surgeries of all time. Glaucoma Risk factors for glaucoma include a family history of glaucoma, age, high blood pressure, African-American descent, and chronic steroid use. There are two
types of glaucoma: acute and chronic. Acute glaucoma, also called angle closure glaucoma, causes sudden pain and an acute increase in intraocular pressure. This is an emergency in which the patient needs to be immediately seen by an ophthalmologist. Chronic, or open-angle glaucoma, is significantly more common that acute glaucoma, and is characterized by increased intraocular pressure, increased optic cup to disk ratio, and visual field defects on testing. In order to minimize peripheral vision loss, close monitoring and compliance with treatment is important. Retinal Detachment Patients with retinal detachment may present with sudden onset of flashes of light, floaters, decreased vision, and a “shadow or curtain” over their visual field. A dilated examination of the retina is required for diagnosis. Early presentation to a retina specialist for retinal detachment repair offers the patient the best change of maximal restoration of vision. Visual prognosis is variable, and depends on a variety of factors. Some common causes of a retinal detachment are trauma and traction from the vitreous. A rhegmatogenous retinal detachment is due to a tear or break in the retina. Subretinal fluid enters through this break and accumulates under the retina, further propagating the detachment. In serous and tractional retinal detachment, there is no retinal break. Age-Related Macular Degeneration Age-related macular degeneration (ARMD) can be divided into two subtypes: wet, or exudative ARMD and dry, or nonexudative ARMD. Dry ARMD is characterized by drusen in the macular region and retinal pigment epithelial atrophy. Wet ARMD is characterized by choroidal neovascularization or retinal pigment epithelial detachment in addition to the findings of dry AMD. In both types of macular degeneration, central vision is first affected. There are a wide array of treatment modalities to help slow down progress and also treat active disease. Patients should monitor their vision with an Amsler grid, and regular follow-ups with an ophthalmologist are important. Temporal Arteritis In patients over the age of 50 who present with headache and associated symptoms, temporal arteritis
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should be suspected. This condition is also known as giant cell arteritis and anterior ischemic optic neuropathy. Associated symptoms include jaw claudication, visual loss, fever, malaise, weight loss, eye pain, and polymyalgia rheumatica. This vasculitis can lead to irreversible visual loss, which is why early treatment is essential. Erythrocyte sedimentation rate (ESR) and c-reactive protein (CRP) are usually elevated in these patients, and definitive diagnosis can be confirmed by a temporal artery biopsy. High-dose steroids should be administered as soon as the physician suspects temporal arteritis. Early diagnosis and treatment can offset involvement of the second eye. Ocular Manifestations of Systemic Diseases Ocular disorders associated with systemic diseases are vast and various. Hypertension is one such disease that has a major impact on the ocular system, in particular the retina. The earliest pathologic feature of hypertensive retinopathy is narrowing of a major arteriole. As the disease progresses in severity, the narrowing of many other arterioles occurs. In younger patients, if the disease progresses rapidly, more dramatic changes may be seen such as occlusion of the arterioles causing blood loss, infarction, to the retina resulting in “cotton-wool spots” or mini-ischemic areas in the retina. Yellow hard exudates, due to lipid deposition deep in the retina and arising from leaking retinal vessels, also develop. Optic disk edema is a prominent feature of severe hypertensive retinopathy called papilledema. Vision is disturbed as a result of these changes. In contrast to the vascular response exhibited by younger patients, elderly patients do not seem to suffer the same retinal changes. The vasculature is often plagued by atherosclerosis, hardening of the arteries due to accumulation of cholesterol and lipids. The vessels are not as vulnerable to injury because of their rigid structure. With successful management of the hypertension, the retinopathy is irreversible. Treatment for the elderly population is not as successful as the atherosclerotic changes are irreversible. Diabetic retinopathy is the leading cause of blindness in American adults, accounting for one-fourth of blind registrants in the Western world. Approximately 6.6 percent of the population between the ages of 20 to 74 has diabetes and approximately 25 percent of the diabetic population has some form of diabetic retinopathy. Diabetic retinopathy accounts for
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Eye Diseases (General) diabetic retinopathy can eventually progress and is the most severe consequence of ocular involvement of diabetes mellitus. With the progressive ischemia to the retina, there is stimulation of the growth of new vessels. These new vessels are friable and may cause extensive hemorrhaging in the eye if not treated early. They may grow near the optic disk, iris (rubeoisis iridis), or into the vitreous. The vitreous may eventually detach from the retina once the vessels begin to proliferate. This tractional pulling of the vitreous away from the retina may also cause the retina to detach. Treatment options consist of laser photocoagulation for proliferative retinopathy and also for the macular edema. If laser treatment is not successful, vitrectomy retinal surgery must be performed to treat the proliferative changes and the hemorrhaging in the eye. SEE ALSO: Blepharitis; Cornea and Corneal Disease; Glau-
The most common eye care problems are low visual acuity and disorders such as cataract, glaucoma, and diabetic retinopathy.
coma; Ophthalmologist.
Bibliography. Mark Beers and Robert Berkow, “Reti-
approximately 10 percent of new cases of blindness each year. There are two major types of retinopathy: nonproliferative and proliferative. Nonproliferative diabetic retinopathy is marked by microaneurysms of the blood vessels, that can bleed into the retina. These hemorrhages may be seen as flame shaped or dot shaped. Macular edema, swelling, is the most common cause of visual loss and can be seen at any stage of the disease. This ������������������������������ is caused by progressive weakening of the vasculature of the retina with resultant either focal or diffuse leakage. Proliferative
nal Disorders,” Merck Manual (v.17, 1999); Mark Dambro, “Retinopathy, Diabetic,” Griffiths 5 Minute Clinical Consult (v.14, 2006); “Diabetes Mellitus,” in Harrison’s Principles of Internal Medicine (McGraw-Hill, 2005); Robert Hardy and Debra Shetlar, Retina (Lange Medical Books/McGrawHill, 2004); Peter K. Kaiser, Neil J. Friedman, and Roberto Pineda II, The Massachusetts Eye and Ear Infirmary Illustrated Manual of Ophthalmology (Saunders, 2004). Komal Bharat Desai, M.D. Sweta Tarigopala, M.S. Jessica Winn, M.S. Independent Scholar
F Facial Injuries and Disorders Facial trauma, also referred to medically as maxillofacial injuries, encompass any injury to the mouth, face, and jaw. Almost everyone has experienced such an injury, or knows someone who has. Most maxillofacial injuries are caused by a sports mishap, motor vehicle accident, on-the-job accident, act of violence, or an accident in the home. A craniofacial disorder refers to an abnormality of the face and/or the head. Craniofacial differences can result from abnormal growth patterns of the face or skull, which involves soft tissue and bones. A craniofacial condition may include disfigurement brought about by birth defect, disease, or trauma. At the hospital, patients will most likely be seen by several medical personnel, one of whom will probably be an oral and maxillofacial surgeon. Oral and maxillofacial surgeons, surgical specialists of the dental profession, are specifically trained to repair injuries to the mouth, face, and jaw. After four years of dental school, oral and maxillofacial surgeons complete four or more years of hospital-based surgical residency training that may include rotations through related medical fields, including internal medicine, general surgery, anesthesiology, otolaryngology, plastic surgery, emergency medicine, and other medical spe-
cialty areas. At the conclusion of this program, oral and maxillofacial surgeons are prepared to perform the full scope of the specialty, which includes emergency care for the teeth, mouth, jaws, and associated facial structures. Facial Injury One of the most common types of serious injury to the face occurs when bones are broken. Fractures can involve the lower jaw, upper jaw, palate, cheekbones, eye sockets, and combinations of these bones. These injuries can affect sight and the ability to breathe, speak, and swallow. Treatment often requires hospitalization. Extensive maxillofacial fractures are often accompanied by other medical problems. A thorough physical examination, including neurologic examination, is necessary following a detailed history. Of particular importance are signs of raised intracranial pressure, other cranial nerve dysfunction, or pupillary abnormalities. The head and neck also require careful attention. Numerous neuralgias have been described as causes of facial pain. Neuralgia is defined as paroxysmal pain in the distribution of a particular nerve. The pain is typically maximal at onset and may be described as lancinating, “electric shocks,” or as “jabbing.” There may be a single sharp pain or repetitive pains in succession. The pain can last a fraction of a
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second or for several seconds. There may be a refractory period after the severe pain during which pain will not occur. Some neuralgic conditions have trigger zones (areas that when stimulated provoke an attack) or other triggers. The oral and maxillofacial surgeon coordinates treatment with other medical specialties to return the patient to his or her normal activities as soon as possible. The principles for treating facial fractures are the same as for a broken arm or leg. The parts of the bone must be lined up (reduced) and held in position long enough to permit them time to heal. This may require six or more weeks depending on the patient’s age and the fracture’s complexity. During the healing period when jaws are wired shut, the oral and maxillofacial surgeon prescribes a nutritional liquid or pureed diet, which will help the healing process by keeping the patient in good health. After discharge from the hospital, the doctor gives the patient instructions on continued facial and oral care. While not all facial injuries are extensive, they are all complex because they affect an area of the body that is critical to breathing, eating, speaking, and seeing. Even in the case of a moderately cut lip, the expertise of the oral and maxillofacial surgeon is indispensable. If sutures are needed, placement must be precise to bring about the desired cosmetic result. Because avoiding injury is always best, prevention includes the use of automobile seat belts, protective mouth guards, and appropriate masks and helmets for everyone who participates in athletic pursuits at any level. New innovations in helmet and mouth and face guard technology have made these devices comfortable to wear and very effective in protecting the vulnerable maxillofacial area. New synthetic materials and advances in engineering and design have produced mouth guards that are sturdier yet lightweight enough to allow the wearer to breathe easily. Mouth guards can vary from the inexpensive “boil and bite” models to custom-fabricated guards made by dentists, which can be adapted to the sport and are generally more comfortable. There are five criteria to consider when being fitted for a mouth protector. The device should be fitted so that it does not misalign the jaw and throw off the bite, lightweight, strong, easy to clean, and should cover the upper and/or lower teeth and gums. By encouraging sports enthusiasts at every level of play to wear mouth guards and other protective equipment,
oral and maxillofacial surgeons hope to help change the “face” of sports. Trauma does not only result from major events such as combat or automobile accidents. Childhood injuries caused by skateboards, sports, or bicycle accidents frequently involve dental or maxillofacial trauma. Younger children often sustain damage to teeth or supporting structures from falls. Various safe and effective sedation techniques can be employed to deliver prompt, comfortable, and successful treatment in the office setting. Impacted Teeth A tooth that fails to emerge or fully break through the gum tissue is, by definition, “impacted.” While this is a common problem associated with third molars, or wisdom teeth, as they are the last teeth to develop and erupt into the mouth, other teeth can also become impacted. Typical symptoms associated with impacted teeth are pain, swelling, and signs of infection in the surrounding tissues. An impacted tooth has the potential to cause permanent damage to adjacent teeth, gum tissue, and supporting bone structure. Impacted teeth are also associated with the development of cysts and tumors that can destroy large portions of the jaw. Many times, impacted wisdom teeth are not treated until symptoms are present; however, a recent study conducted by the American Association of Oral and Maxillofacial Surgeons and the Oral and Maxillofacial Surgery Foundation indicates that third molars should be removed by the time the patient is a young adult in order to prevent related gum disease or other problems. Facial Infections Infections in the maxillofacial region can develop into life-threatening emergencies if not treated promptly and effectively. Pain and swelling in the face, jaws, or neck may indicate an infection of dental or related origin. Temporomandibular Joint Disorders (TMJ) and Facial Pain A common cause of facial pain and headache is disease or dysfunction of the TMJ. Located where the lower jaw and skull meet, the TMJ is the ball and socket joint that enables the lower jaw (mandible) to move and function. TMJ disorders display a number of symptoms that may include earaches, headaches,
and a limited range of movement. Patients may also complain of clicking or grating sounds in the joint, or pain when opening or closing their mouths. Causes of TMJ disorders can be degenerative (osteoarthritis), traumatic (cartilage displacement or injury), inflammatory (rheumatoid arthritis), or stress related. Some patients experience a combination of muscle and joint problems. In order to properly diagnose and treat the problem, a clinical examination and a number of diagnostic procedures, including imaging studies (radiograph, computed tomography, magnetic resonance imaging) are utilized. Usually, nonsurgical management (soft diet, antiinflammatory drugs, physical, and/ or bite splint therapy) is the first step. For certain conditions, joint surgery may be an appropriate option. Lysis and lavage and arthroscopic joint surgery are minimally invasive procedures that have proven effective in resolving certain conditions involving TMJ pain and dysfunction. These procedures can be done under general anesthesia on an outpatientsurgery basis at a hospital or ambulatory surgery center. More complex joint surgery may be indicated for advanced conditions. Oral Pathology Dental pathology is a common cause of facial pain. Specific inquiry regarding prior dental procedures should be made of all patients with facial pain. The presence of provocative factors such as chewing or heat or cold sensitivity may provide useful clues. Trigeminal neuralgia also has been associated with ipsilateral dental pathology. Cancer is a rarer cause of facial pain. Extracranial bony or soft tissue metastases may impinge upon cranial and upper cervical nerves causing headache or facial pain. In addition, occult lung neoplasms may cause referred pain in the periauricular region. Facial pain due to cancer is discussed in detail separately. If indicated, biopsies and other tests can be performed to diagnose the problem and develop an appropriate treatment plan. Early detection and treatment of oral lesions greatly improve the patient’s prognosis. Lesions may be managed medically and/or surgically. Oral and Facial Deformities Differences in skeletal growth between the upper and lower jaws may lead to both functional and psychological difficulties. Functional difficulties may in-
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clude problems with chewing, swallowing, speech, or TMJ performance. Patients may also exhibit psychological difficulties stemming from aesthetic and social concerns. Some abnormalities may only involve misaligned teeth and can be corrected orthodontically with braces or other appliances. Serious growth disturbances, however, require surgery to realign the upper and lower jaws into a more normal relationship. Common dentofacial deformities, including under- or overdevelopment of the jaws (prognathia, micrognathia, retrognathia), or misaligned teeth (overbite or underbite), can make it difficult to eat, swallow, speak, and breathe. Corrective jaw surgery can be performed to produce a more balanced, functional skeletal relationship for the patient. Often performed in conjunction with treatment by an orthodontist and restorative dentist, corrective jaw surgery is usually performed in a hospital or ambulatory surgical center under general anesthesia. Congenital deformities such as cleft lip and palate occur when all or a portion of the oral-nasal cavity does not grow together during fetal development. Cleft lip and/or palate is a separation of the parts or segments of the lip or roof of the mouth, which are usually joined together during the early weeks in the development of an unborn child. A cleft lip is a separation of the two sides of the lip and often includes the bones of the maxilla and/or the upper gum. A cleft palate is an opening in the roof of the mouth and can vary in severity. A cleft palate occurs when the two sides of the palate do not fuse as the unborn baby develops. A team of healthcare specialists play an important role in the carefully orchestrated, multiple-stage correctional program for these patients. The goal is to help restore the jaw and facial structures, leading to normal function and appearance. Care and treatment must consider function, appearance, nutrition, speech, hearing, and emotional and psychological development. Burning Mouth Syndrome (BMS) BMS is defined as burning pain in one or several oral structures. Affected patients often present with multiple oral complaints, including burning, dryness, and taste alterations. Burning mouth complaints are reported more often in women, especially after menopause. Typically, patients awaken without pain but note increasing symptoms through the day
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and into the evening. Usually, no obvious etiology is found, but several possibilities exist that can be divided into local and systemic causes. A careful history and oral cavity examination assist in diagnosing the cause of BMS, which locally may include allergy, denture irritation, oral habits, infection (e.g., oral candidiasis), and reflux esophagitis. Systemic causes include vitamin and mineral deficiency, diabetes mellitus, and chemotherapy. SEE ALSO: Accidents; American Dental Association
(ADA); Birth Defects; Child Dental Health; Cleft Lip and Palate; Dental Health; Ear Infections; Oral Surgeon.
Bibliography. E. Bohm and R.R. Strang, “Glossopha-
ryngeal Neuralgia,” Brain (v.85, 1962); C. Feinmann, “Idiopathic Orofacial Pain: A Multidisciplinary Problem,” in Pain: An Updated Review (IASP Press, 1996); C. Feinmann, “The Long-Term Outcome of Facial Pain Treatment,” Journal of Psychosomatic Research (v.37, 1993); J.E. Horgan, et al., “OMENS-Plus: Analysis of Craniofacial and Extracraniofacial Anomalies in Hemifacial Microsomia,” Cleft Palate-Craniofacial Journal (v.32, 1995); D. Mock, W. Frydman, and A.S. Gordon, “Atypical Facial Pain: A Retrospective Study,” Oral Surgery, Oral Medicine, and Oral Pathology (v.59, 1985); E.J. Ratner, et al., “Jawbone Cavities and Trigeminal and Atypical Facial Neuralgias,” Oral Surgery, Oral Medicine, and Oral Pathology (v.48, 1979); J.G. Rushton, J.C. Stevens, and R.H. Miller, “Glossopharyngeal (Vagoglossopharyngeal) Neuralgia: A Study of 217 Cases,” Archives of Neurology (v. 38, 1981); P. Tessier, “Anatomical Classification Facial, Cranio-Facial and Latero-Facial Clefts,” Journal of Maxillofacial Surgery (v.4, 1976); L.P. Tourne and J.R. Fricton, “Burning Mouth Syndrome. Critical Review and Proposed Clinical Management,” Oral Surgery, Oral Medicine, and Oral Pathology (v.74, 1992). Barkha Gurban, B.A. University of California, Los Angeles
Failure to Thrive Failure to thrive is a term traditionally associated with pediatrics, describing a weight gain and physical growth delay that can impair a child’s development and maturation. The term has been borrowed into ge-
riatric literature to describe a situation where elderly people fail to maintain functional and nutritional status disproportionally to their health conditions. Pediatric Failure to Thrive Children are said to fail to thrive when presenting with clear underweight or failing to gain weight without an obvious reason. Different medical, psychological, environmental, and social factors are known that can impair normal growth in children. Medical disorders, notably but not exclusively affecting the digestory tract, may affect food intake, retention, digestion, or absorption. Parental abuse may impair a child’s appetite and different environmental and social factors may prevent the child from getting adequate nutrition. These include family’s environment and financial status—the regularity and quality of a child’s feeding directly reflect his or her development. The diagnosis is made when a child’s weight or rate of growing is far from what it should be by comparison with previous measures or height-weight charts and the treatment is based on eliminating the underlying cause. Nutritional supplementation is always offered and severe cases are treated in the hospital. Because the first year of age is crucial in brain development, failure to thrive during this time may result in a permanent mental deficit from mild to severe. The best way to avoid this is based on the early identification and treatment of failure to thrive. Geriatric Failure to Thrive Geriatric failure to thrive is a syndrome and a diagnosis of exclusion in older people. It is defined by weight and function loss and it can lead to death in a short time. This condition has a prevalence of 10 to 20 percent after 65 years of age and may be caused by either organic disease or nonorganic problems, such as psychological, functional, or social problems. Failure to thrive is characterized by progressive loss of physical functioning, weight, and lean body mass. Malnutrition, characterized by a loss of fat mass and visceral protein, is an important risk factor and so is low muscle mass, because it relates to physical function. Failure to thrive as a medical diagnosis is acceptable when its causes cannot be made clear. Almost all chronic systemic diseases and some medications can cause failure to thrive in very old people. Nonorganic
Fainting
causes of failure to thrive are usually linked to inability to get food, lack of interest in food or anorexia, or inability to consume available food. Depression is the most common psychological risk factor. Eating is a social event and it is not a surprise that social isolation also may lead to decreased food intake and failure to thrive. Poverty is also an important risk factor. Abuse also may cause failure to thrive in the elderly, especially on those more frail and incapable of self-defense. The clinical picture of geriatric failure to thrive due to abuse is nearly identical to the effects of abuse-related pediatric failure to thrive. The treatment of the potential causes is the basis of treatment of geriatric failure to thrive and dietary supplementation is also important and cost-effective in all cases. Geriatric failure to thrive is often treatable, with a positive impact on an older person’s health. SEE ALSO: Elder Abuse; Geriatrics; Nutrition; Pediatrics. Bibliography. Edmund Duthie, Practice of Geriatrics,
3rd ed. (Saunders, 1998 ); S.D. Krugman and H. Dubowitz, “Failure to Thrive,” American Family Physician (v.68/5, 2003); R.G. Robertson and M. Montagnini, “Geriatric Failure to Thrive,” American Family Physician (v.70/2, 2004). Thiago Monaco University of Sâo Paulo Medical School,
Fainting Fainting (medically known as syncope) is a sudden brief loss of consciousness and postural tone. The most common presentation of fainting is a person who was standing or sitting upright and then suddenly began to feel uneasy and uncomfortable. The person may sway, become anxious, or develop a headache; he or she often becomes pale or his or her face will turn a gray color. Before fainting, the skin will be damp and cold from sweat. Other symptoms include salivation, stomach upset, nausea, vomiting, ringing in the ears, and vision that may dim or close in concentrically. Patients attempt to suppress these symptoms by deep breathing, yawning, and sighing. Some fainting episodes can be suppressed by lying down. However, when an episode occurs, the patient typical-
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ly collapses to the ground and is motionless (this differs from a seizure, which typically causes patients to exhibit convulsive movements). The skeletal muscles typically remain fully relaxed, and the patient retains control over bowel and bladder function. The fainting episode usually lasts a few seconds to minutes, but it is rarely longer than five minutes. Classification and Causes There are three main types of fainting: neurogenic, orthostatic, and cardiogenic. All three are associated with a temporary significant reduction in blood flow to the brain. Systolic blood pressure is decreased, typically to less than 60 mm Hg. Neurogenic faints are of several different types. The most common of these is vasovagal fainting. Vasovagal fainting occurs mainly in young patients and people in good health. It is not suggestive of any underlying disease. There is also evidence of a familial predilection. The reason for the faint is a block of the normal sympathetic nervous system reaction to bodily stress. For instance, physical and emotional stresses normally cause an increase in sympathetic nervous system activity. This is reflected by an increase in heart rate, blood pressure, and the volume of blood pumped by the heart each minute (cardiac output). A variety of situations can trigger a vasovagal faint. These include bodily pain or injury (especially involving the internal organs), exercise, strong emotions, and situations that cause dilation of peripheral blood vessels (such as a hot, crowded room, particularly when a person is fatigued or has ingested alcohol). Carotid sinus hypersensitivity is another type of neurogenic fainting. The carotid sinus is a dilated portion of the carotid artery, which is one of the major arteries supplying blood to the head. The sinus has nerve endings and senses changes in blood pressure. It sends feedback to the vasomotor center in the medulla—this is an area of the brainstem that controls blood pressure and heart rate. For patients with carotid sinus hypersensitivity, compression of the sinus by everyday activities such as turning one’s head to the side, shaving, wearing a seatbelt, or tightening a necktie can cause the patient to faint. There are two abnormal responses that take place simultaneously: a vagal response and a vasodepressor response. The vagal response is a reflex action by the body which slows the heart rate (bradycardia) and causes a pause in the heartbeat (asystole)
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for greater than three seconds. The vasodepressor response is a decrease in the systolic blood pressure by more than 50 mm Hg without causing a significant change in heart rate. Carotid sinus hypersensitivity is most common in elderly men and patients with ischemic heart disease, hypertension, and head or neck tumors. Fainting typically occurs suddenly and while the patient is standing. The patient may have small convulsive movements during the episode. The faint rarely lasts longer than 30 seconds. Neurogenic fainting also includes situational reflex syncope. This type of fainting includes a variety of conditions with physical stimuli that can trigger an abnormal autonomic response. Examples include micturition, swallowing, exercise, and coughing. Micturition fainting mainly affects elderly men, typically at night when they awake to use the bathroom. The faint usually occurs at the end of voiding. The physiology behind this type of fainting is that the patient will awaken with a full bladder and associated vasoconstriction of the abdominal and pelvic blood vessels. When the bladder is emptied, the vessels dilate and consequently the patient becomes hypotensive. During sleep, the heart rate and resistance in the peripheral blood vessels are low, and this adds to the body’s delay in being able to correct the low blood pressure. Factors that increase the risk of micturition fainting include fatigue, hunger, upper respiratory infection, and alcohol ingestion. Fainting can also occur after difficulty swallowing in patients with esophageal disease. It is thought that an increase in intrathoracic and/or intraabdominal pressure may cause a decrease in blood flow to the brain, thus precipitating a faint. A similar mechanism is thought to be the cause of fainting after sudden vigorous coughing. Coughing also increases the intracranial pressure, further limiting cerebral blood flow. Exercise-induced fainting typically occurs with aerobic exercise, such as running. It is associated with nausea and is thought to be a familial condition. Medications, such as beta-blockers, may be helpful for these patients. When considering exercise as a possible trigger for fainting, it is important to first rule out heart disease or abnormality. Orthostatic fainting is another type of fainting. It is a result of orthostatic hypotension—a decrease in the systolic blood pressure greater than 20 mm Hg when a person suddenly rises from a supine or seat-
The most common presentation of fainting is a person who was standing or sitting upright and then suddenly began to feel uneasy.
ed position to standing or when someone is standing for an extended period of time. These patients have an inability to adjust their blood pressure for changes in position. For instance, upon standing for a long time, the blood pools in their legs (due to gravity), and there is constriction of the vessels in abdomen and upper extremities. Since a large volume of blood rests in the legs, less blood is able to be pumped to the brain. Fainting usually occurs within three minutes of being upright. The most common reasons for orthostatic hypotension and consequent fainting are a depletion of the central or total blood volume and the effects of medications (particularly antihypertensives and antidepressants). The underlying etiology may also involve impaired autonomic reflex control, the circulation of vasodilators (such as in a patient with carcinoid syndrome), or returning to activity after a period of prolonged bed rest, fasting, or alcohol use. Diabetes, alcoholism, pernicious anemia, and degenerative diseases of the nervous system (i.e., Parkinson’s disease) have all been linked to orthostatic fainting. Cardiogenic syncope is the third main type of fainting. The faints occur due to a sudden significant decrease in cardiac output. The symptoms that a patient experiences depend on the presence of cerebrovascular
atherosclerotic disease and the nervous system’s ability to compensate for the decline in cardiac output. The underlying cause may be electrical or mechanical. Electrical causes are more common, of which dysrhythmia is the most frequent diagnosis. Atrioventricular (AV) heart block is the dysrhythmia most likely to cause fainting. In healthy individuals, the body can normally adjust to maintain cerebral blood flow when the heart rate in between 40 and 185. However, patients with dysrhythmias have a decreased tolerance to changes in heart rate, and this is particularly evident in patients with premorbid cerebrovascular disease, coronary artery disease, and valvular disease. Fainting due to dysrhythmias is sudden and usually lasts less than three seconds. There are rarely any warning symptoms. Mechanical causes of cardiogenic fainting include outflow obstructions of the left and right ventricles, congenital heart defects with shunting, and acute massive myocardial infarction. Cardiac output is not sufficient to meet the body’s demands, particular during periods of high stress such as exercise. Symptoms tend to occur during physical exertion, but may also be precipitated by medications or heat stress. Evaluation A detailed history and physical examination provides a strong foundation for evaluating a patient who has fainted. The majority of cases will be able to be diagnosed based on the history and physical alone, without additional testing. A chronological account of the fainting episode—including the events and symptoms preceding it—is essential to the evaluation. The physician will ask about the patient’s posture or positioning, the environment they were in, the activity they were doing at the time, and the presence of any seizure activity. It is also important to know the patient’s past medical history and any medications they are taking (prescription and over the counter). With regard to the physical exam, attention is directed at the cardiovascular and neurologic systems. Patients are examined for orthostatic hypotension, hypertension, cardiac rhythm abnormalities, heart murmurs, signs of congestive heart failure, neurologic deficits, and signs of peripheral neuropathy. If patients have symptoms of carotid sinus hypersensitivity or if elderly patients have had multiple fainting episodes, a procedure called carotid sinus massage is often helpful in diagnosis. One sinus is massaged for
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five seconds and then the heart rate and blood pressure are monitored for changes. If there is a pause in the heartbeat for more than three seconds or if the blood pressure decreases more than 50 mm Hg without a significant decline in heart rate, this is suggestive of carotid sinus hypersensitivity. Carotid sinus massage is repeated on the other side to complete the evaluation. An electrocardiogram (ECG) is the test of choice for patients who have had a fainting episode. It is commonly done in all patients but is crucial in the evaluation of patients whose diagnosis is not clear from the history and physical examination. The ECG is helpful in identifying cardiogenic causes of syncope such as heart block, ventricular tachycardia, or myocardial infarction. For cases in which the history, physical exam, and ECG are not conclusive, other diagnostic tests can be done. These include echocardiogram, ambulatory ECG, exercise ECG, electrophysiologic studies, and cardiac catheterization. If all of these tests are negative, headup-tilt testing is done with hemodynamic monitoring. Treatment The treatment of fainting is directed toward correcting the cause of decreased cerebral blood flow and preventing future episodes. Patients who are seen while fainting or after losing consciousness should be positioned so that cerebral blood flow is maximized. The head should be lowered between the knees or the patient should be placed in the supine position with both legs elevated. The head should be positioned so that the tongue is not at risk for falling into the back of the throat. Any tight clothing should be loosened. It is important that the patient does not try to stand or sit up until the sense of weakness resolves. Prevention of fainting episodes depends on the particular type of fainting. Patients who have vasovagal episodes are encouraged to avoid physically and emotionally stressful environments. Beta-blockers, particularly acebutolol, have been used with success. Education is important for patients with carotid sinus hypersensitivity. Patients should be told of ways to decrease the risk of fainting. These include wearing a loose shirt collar and turning one’s whole body to look from side to side rather than just turning the head. Atropine has been effective in helping patients who have profound decreases in blood pressure and/or heart rate. Patients who do not respond
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to preventive measures or medications may be eligible for pacemaker placement. Patients with orthostatic hypotension are advised to exercise their legs for a few seconds and sit at the edge of their beds before standing. If these patients know they will be standing for an extended period of time, crossing their legs forcefully can help to prevent a faint. Alternative medications can also be used for patients using antihypertensives and antidepressants if it is believed that medications are playing a role. Elderly patients with recurrent fainting episodes are at significant risk of falls, fractures, and trauma. Preventive measures are recommended for around the home in order to decrease risk of injury. This includes covering the bathroom floor and bathtub with mats and increasing carpeting in the home. These patients are encouraged to walk on soft ground when outdoors and avoid standing in place for long periods. Padded hip protectors can also be worn for protection. SEE ALSO: Cardiology; Coronary Disease; Stress; Stroke. Bibliography. “Orthostatic Hypotension and Syncope,”
in Mark H. Beers and Robert Berkow, eds., The Merck Manual (Merck, 1999); Sumanth Prabhu, Robert A. O’Rourke, and J. Donald Easton, “Faintness and Syncope: Pathophysiology,” in Jay H. Stein, comp., Internal Medicine (Mosby, 1998); Allan H. Ropper and Robert H. Brown, “Faintness and Syncope,” Adams and Victor’s Principles of Neurology (McGraw-Hill, 2005). Stacy A. Frye Michigan State University
Falls A very large number of admissions to hospitals come from falls which are defined as movement of people because of gravity. The vast number of personal injuries, both small and very serious and even fatal, is particularly common in elderly people where their vision and muscles are weakened. In addition, some elderly people taking multiple prescription medication may also lose balance, which combined with slower reaction times often prove serious, with their bones often being more susceptible to major damage. Although large numbers
of children and adolescents are also involved in falls, their simple injuries often heal relatively easily; however, others have sustained serious injuries through risky behavior. According to figures for 2002 issued by the World Health Organization, some 392,000 people died from falls that year. Although many falls have resulted in deaths, others result in breakages of bones, bone fractures, or muscle and/or tendon injury or sprain. Throughout history, there have been many people who have been injured from or died as a result of falls. In Greek mythology, Icarus fell from the skies after flying too close to the sun, and the heat from the sun melted the wax which held his wings together. Although falling over, falling off a cliff or other natural formation, have always led to medical problems, falls by rulers have sometimes been seen as ill omens. Duke William of Normandy fell in the sand when he landed on the beach at Pevensey, on the south coast of England on September 28, 1066, prior to the Battle of Hastings. While his men thought it was a portent of disaster, William rose with his hands clutching sand claiming it represented his seizure of England. Julius Caesar, suffering from epilepsy, also fell to the ground on some occasions, but suffered no injuries. U.S. President Gerald Ford also became famous for two public falls. Until recently, falls from horses have led to large numbers of deaths and injuries, and still cause death and injury. Ptolemy VI “Philometor” of Egypt died after falling from his horse during battle and Alexander III of Scotland died when his horse fell over a cliff. Some of the important historical characters who have died from falling from horses include Pippin III, father of Charlemagne; John I, king of Aragon and his cousin John I, king of Castile; and James, Earl of Cardigan, who led the British cavalry at the Charge of the Light Brigade in 1854. William III of Orange, King of England died from injuries sustained after his horse tripped over a mole hill, leading to his enemies, the Jacobites, toasting “the little man in black.” Many jockeys have been killed or injured by falling from horses during races. People have also been injured or killed falling from trains, buses, and occasionally even from cars, usually when hanging on to them. The biggest fall from which someone survived was by Vesna Vulovi who, in 1972, survived a fall from 33,000 feet without a parachute. Some people engaged in high-risk activities have also been killed in falls. Mountaineer Francis Maitland Balfour, founder of embryology, died from a fall from
False Positive
Mont Blanc, and British Everest mountaineer George Mallory almost certainly died from a fall while climbing Mount Everest. Circus acrobat Karl Wallenda died from a fall from a tightrope in San Juan, Puerto Rico, and many circus performers have been injured in falls during trapeze or other acts. There have also been many people who have been killed or injured by falls from buildings. Some opponents of the Medicis in Renaissance Italy were thrown from the Palazzo Vecchio into the Piazza della Signoria in Florence, and the Thirty Years War in 1618 began with the defenestration by the people and the burghers of Prague when two royal deputies and a secretary were thrown from the window of the royal castle of Hradcany in Prague on May 23, 1618. In the incident at Prague, the three survived. One of Napoleon’s marshals, Louis-Alexandre Berthier, Prince of Wagram, died from a fall from a window, in suspicious circumstances; U.S. writer Constance Fenimore Woolson died from a fall from her apartment in Venice; several stock brokers died after falling from tall buildings in Wall Street during the stock market crash in 1929; James V. Forrestal, the first U.S. Secretary of Defense, fell from the Bethesda Naval Medical Center, Maryland, while suffering from depression; and many others, less famous, have fallen from buildings. SEE ALSO: Fractures; Sprains and Strains. Bibliography. Rose Anne Kenny, ed., Syncope in the
Older Patient: Causes, Investigations and Consequences of Syncope and Falls (Chapman & Hall Medical, 1996); National Health and Medical Research Council (Australia), Falls and the Older Person: Report of the Health Care Committee Expert Panel for Health Care of the Elderly (National Health and Medical Research Council, 1994).
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particularly common in studies with relatively small sample sizes. In medicine, false-negative findings are cases in which a test fails to detect a condition when it is actually present. This is often studied within the framework of receiver operating characteristics (ROC) curves, which graphically represent the tradeoff between false-negative and false-positive findings for a particular test or set of tests. SEE ALSO: Diagnostic Tests; False Positive. Bibliography. David De Vaus, Surveys in Social Research
(Routledge, 2002); A. Rolfs, PCR: Clinical Diagnostics and Research (Springer-Verlag, 1997). Fernando De Maio, Ph.D. Simon Fraser University
False Positive This type of error involves the rejection of the null hypothesis when it is actually true. It is also known as a Type I error or α error. The null hypothesis, a statement of equality, always asserts that there is no relationship between the independent variable and the dependent variable. It is this assertion that forms the basis of inferential statistics, which can be used to determine our level of confidence that our findings (based on data from a random sample) represent true patterns in the population. A statistical test’s level of significance (α, or alpha)
Justin Corfield Geelong Grammar School, Australia
False Negative This type of error involves the acceptance of the null hypothesis when it is actually false; in other words, it represents a failure to detect a real effect. It is also known as a Type II error or β error. These errors are
A false positive involves the rejection of the null hypothesis when it is actually true, and is also known as a Type I error.
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indicates the risk of a false-positive finding. A level of significance of 0.05 is normally accepted in social science; this indicates that we accept a 5 percent chance of making a false-positive error. At more demanding significance levels, such as 0.01 or 0.001, the probability of making false-positive conclusions are lower. For example, consider a study that observes a 2.5point difference in mean body mass index between groups A and B. A researcher may use a t-test to examine the statistical significance of that difference in mean scores. If the resulting test has a significance value of less than 0.05, the researcher would conclude that the difference between the groups is real. However, if the significance value of the t-test was greater than 0.05, the likelihood of a false-positive finding would be too great and the researcher would conclude that the groups do not differ in body mass index score (even though their results indicated a 2.5-point difference). SEE ALSO: Diagnostic Tests; False Negative. Bibliography. David De Vaus, Surveys in Social Research
(Routledge, 2002); A. Rolfs, PCR: Clinical Diagnostics and Research (Springer-Verlag, 1997). Fernando De Maio, Ph.D. Simon Fraser University
Farmer, Paul (1959–) Dr. Paul Farmer is a medical anthropologist, a physician, and a professor of Medical Anthropology at Harvard University. Dr. Farmer is also a founding director of Partners in Health, an international organization that provides direct healthcare services, research, and advocacy for those who are sick and living in poverty in resource-poor areas. Dr. Farmer specializes in infectious disease control in resource-poor areas and has pioneered novel approaches to community-based strategies for infectious disease control, including HIV/AIDS and multidrug-resistant tuberculosis. He has published numerous works capturing his experiences in Haiti and detailing his view of the socioeconomic factors of disease progression. Dr. Farmer first worked in Haiti in 1983 before he began medical school at Harvard University. His work
in Haiti is based upon a multifaceted approach to address the healthcare needs in Haiti and other resourcepoor areas. Dr. Farmer fostered his deep commitment to work in Haiti to address healthcare issues and moved forward to found Partners in Health (PIH) in 1987. The mission statement of PIH is “whatever it takes” and captures Dr. Farmer’s dedication to his work. Working with colleagues, Dr. Farmer created a model of communitybased healthcare that provides healthcare, food, clean water, housing, education, and other social services. This PIH model is based upon his belief that illness is caused by various socioeconomic factors that renders a patient vulnerable to disease. PIH has initiated a model of community-based care that proved that infectious diseases could be successfully treated. PIH has since become a worldwide health and social justice organization. Dr. Farmer has moved forward with an agenda to develop a system of healthcare that will continue to reach millions of afflicted poor in Haiti, Peru, Russia, Mexico, Guatemala, Rwanda, and Boston’s inner city. Beyond PIH Dr. Farmer is a course director at Harvard University, and also guest lectures at universities throughout the world. Dr. Farmer is a key player pushing forward AIDS/tuberculosis global agendas. He continues to train medical students and colleagues at Brigham and Women’s Hospital in Boston. Dr. Farmer has received numerous prestigious awards for his dedication in securing healthcare for the sick in resource-poor areas. Publications Dr. Farmer has authored and coauthored over 100 articles, authored 6 books, and is the focus of another book that narrates his experience in Haiti. SEE ALSO: AIDS; Haiti; Tuberculosis. Bibliography. Harvard Medical School, Department
of Social Medicine, “Paul Farmer, MD, PhD,” http://www. hms.harvard.edu/dsm/WorkFiles/html/people/faculty/ PaulFarmer.html (cited July 2007); Brigham and Women’s Hospital, “Social Medicine & Health Inequalities,” http:// www.brighamandwomens.org/socialmedicine/aboutfarmer.aspx (cited August 2003). Sudha R. Raminani, M.S. The Fenway Institute
Federal Emergency Management Agency (FEMA)
Federal Emergency Management Agency (FEMA) Since the beginning of the 19th century, the federal government has responded to disasters which include hurricanes, earthquakes, tornadoes, floods, fires, hazardous material spills, and terrorism. The roots of the Federal Emergency Management Agency (FEMA) can be traced to the Congressional Act of 1803 when Congress authorized a federal response to a fire that destroyed much of a New Hampshire town. Subsequently, Congress passed over 100 laws to authorize assistance on a piecemeal basis. In the 1930s, the Reconstruction Finance Corporation was authorized to offer loans to repair public facilities after disasters struck. In 1934, the Bureau of Public Roads assumed responsibility for repairing public roads and bridges damaged by national disasters. The Federal Disaster Assistance Administration was subsequently established under the auspices of the Department of Housing and Urban Development (HUD) in response to a series of disasters that included Hurricane Carla (1962), the Alaskan earthquake (1964), Hurricane Betsy (1965), Hurricane Camille (1969), Hurricane Agnes (1972), and the San Fernando earthquake (1971). The National Flood Insurance Act was passed in 1968. In 1979, President Jimmy Carter consolidated existing disaster-related responsibilities into FEMA. Statutory authority for FEMA activities can be traced to the Disaster Relief Act of 1974 and the Robert T. Stafford Disaster Relief and Emergency Assistance Act of 1988. After the terrorist attacks on the United States on September 11, 2001, which caused the deaths of nearly 3,000 people, the Department of Homeland Security (DHS) was created by the Emergency Supplement Act (PL-107-38) to oversee counterterrorism activities and to plan responses to potential future attacks. On March 1, 2003, in the biggest government reorganization since the end of World War II, FEMA became part of DHS. Congress then appropriated billions of dollars to FEMA to be used in preparing the nation for potential attacks by terrorists. FEMA’s mission has remained the same, and agency officials describe FEMA activities as a “disaster life cycle” in which the agency tries to prevent emergencies and disasters from occurring while preparing to
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deal with all eventualities. Whenever emergencies and disasters do occur, FEMA responds, assists in recovery, mitigates effects, and reduces risk of loss. As part of that responsibility, FEMA trains first responders and oversees the National Flood and Crime Insurance programs. Today, FEMA employs more than 2,600 full-time workers distributed among the national and regional offices and the Mount Weather Emergency Operations Center. Some 4,000 standby employees are attached to the National Emergency Training Center, located in Emmitsburg, Maryland. The national headquarters of FEMA is located at 500 C Street, SW, Washington, D.C. 20472. Additional information on FEMA is available by phone (1-800-462-7595) or on the internet (http://www.fema.gov/). Requests for disaster aid are channeled through a hot line (1800-621-FEMA). The agency Web site serves as a resource for disaster information on chemicals, dam failure, earthquakes, fires, floods, hazardous materials, heat, hurricanes, landslides, nuclear disasters, terrorism, thunderstorms, tornadoes, tsunamis, volcanoes, wildfire, and winter storms. The director, who is answerable to the director of Homeland Security, serves as the head of FEMA. The FEMA director is supported by the chief of staff and the director of operations. The agency is divided into three divisions according to responsibilities: Mitigation, Recovery, and Response. The internal structure of FEMA is subdivided into the Office of Equal Rights, the Office of the Executive Secretariat, the Office of General Counsel, the Office of National Security Coordination, the Office of Plans and Programs, the Office of Policy, the Office of International Affairs, the Office of Intergovernmental Affairs, the Office of Legislative Affairs, and the Office of Public Affairs. Ten regional offices provide direct support for designated geographic areas. Puerto Rico and the Virgin Islands are covered by Region II, along with New York and New Jersey; and Region IX bears responsibility for American Samoa, Guam, the Commonwealth of the Northern Marian Islands, the Republic of the Marshall Islands, and the Federated States of Micronesia, along with Arizona, California, Hawaii, and Nevada. When a disaster occurs, the governor(s) of the affected state(s) may request assistance from FEMA through regional offices. FEMA responds by conducting a preliminary disaster assessment. The presi-
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Federal Emergency Management Agency (FEMA)
Workers remove marine debris leftover from Hurricane Katrina. FEMA funds wet debris removal, which the Coast Guard oversees.
dent may subsequently authorize federal assistance on the basis of emergency declarations or major declarations. In the first case, assistance is capped at $5 million per event and takes the form of emergency services and mitigation. Additional funding may be authorized by Congress. In the case of major declarations, the president determines that the resources of state and local governments are inadequate to respond to natural events such as hurricanes, floods, and earthquakes, thereby authorizing the entire range of federal assistance programs. As part of its response efforts, FEMA officials work with state and local officials to deal with various aspects of the disaster. Postemergency assistance is available to individuals, communities, businesses, nonprofit organizations, and local emergency workers. This assistance often takes the form of grants, such as those awarded for specific disasters, environmental and historic preservation, hazard-related disasters, and nondisasters. The Repetitive Flood Claims Programs, which assists states and communities in areas that have filed one or more claims, is scheduled to close. FEMA grants may also be awarded for preparedness disaster training for specific groups such as firefighters and first responders. Direct assistance may take the form of loans, legal services, crisis counseling, unemployment assistance, emer-
gency food and shelter, and public assistance. FEMA also funds the National Urban Search and Rescue Response System to assist communities in the purchase, maintenance, and storage of rescue equipment and with training exercises and facilities. FEMA agents are available to conduct preparedness and response training for individuals, emergency workers, government personnel, businesses, farmers, teachers, tribal representatives, and volunteer agencies. When Hurricane Katrina stuck America’s Gulf Coast on the night of August 29, 2005, it set off a chain of events that tested FEMA’s ability to respond to disasters to the limit. Subsequent testimony revealed that FEMA Director Michael Brown had informed the Bush administration that New Orleans, which is situated 20 miles below sea level, was extremely vulnerable to flooding if the outdated levees were breeched. Requests for federal funding to update the levee system had previously been denied. On September 30, the levees broke, and 37 billion gallons of water poured into New Orleans. Thousands of people who had not been able to leave the city were stranded in public buildings without food, water, sanitary facilities, medicine, or other necessities. When television cameras brought the plight of the city to national attention, the public responded with outrage. FEMA was harshly criticized for its belated response, and criticism continued even after Brown resigned. Some critics believe the Bush administration’s decision to strip FEMA of its independence led to the poor national response to Katrina. In 2006, a bipartisan Senate report, Hurricane Katrina: A Nation Still Unprepared, maintained that FEMA was beyond repair and recommended that the agency be dismantled and replaced with a newly created National Preparedness and Response Authority. See ALso: Disasters and Emergency Preparedness. Bibliography. Ronald J. Daniels, et al., eds., On Risk and
Disaster: Lessons from Hurricane Katrina (University of Pennsylvania Press, 2006); Federal Emergency Management Agency (FEMA), http://www.fema.gov/; FEMA, Disaster Assistance: A Guide to Recovery Programs (FEMA, 2005); Spencer S. Hsu, “Senate Report Urges Dismantling of FEMA,” Washington Post (April 27, 2006); Roger L. Kemp, Homeland Security Handbook for Citizens and Public Officials (McFarland, 2006); Roger L. Kemp, The McGraw-Hill Security Handbook (McGraw-Hill, 2006);
Fee-for-Service
Kenneth J. Meier and Laurence J. O’Toole Jr., Bureaucracy in a Democratic State: A Government Perspective (Johns Hopkins University Press, 2006); James F. Miskel, Disaster Response and Homeland Security: What Works, What Doesn’t (Praeger Security International, 2006); Dennis D. Riley, et al., Bureaucracy and the Policy Process: Keeping the Promises (Rowman & Littlefield, 2006); Louis Rowitz, Public Health for the 21st Century: The Prepared Leader (Jones and Bartlett, 2006); William M. Thaler, ed., Emerging Issues in Homeland Security (Nova Science, 2005). Elizabeth R. Purdy, Ph.D. Independent Scholar
Fee-for-Service Traditionally, fee-for-service is a payment structure in which healthcare providers are paid a specified amount for each service they provide, including office visits, diagnostic tests, and medical procedures. Indemnity refers to insured individuals directly paying healthcare providers for a service, submitting bills to their insurance company, and then subsequently being reimbursed or indemnified for incurred costs. While fee-for-service and indemnity have inherently different meanings, the two terms are now often used interchangeably. Fee-for-service or traditional indemnity health insurance plans typically allow patients the freedom to choose any physician or hospital as well as allow patients to self-refer to specialists. This is unlike most forms of managed care in which patients choose a primary care physician from a panel of doctors their health plan has contracted with to provide services. This physician then manages his or her patient’s care by coordinating services and making appropriate specialist referrals. With fee-for-service plans, freedom of choice and flexibility come at a significant price. Insured individuals must pay a monthly fee or premium to their insurance company, an annual deductible, and coinsurance in which, for example, a patient pays 20 percent of his or her healthcare bill and the insurer pays 80 percent. Most fee-for-service plans do, however, have a cap or limit on how much an individual has to pay in out-of-pocket expenses for the year. Once this cap is reached, the insurance company pays for all subsequent costs.
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There are undoubtedly advantages as well as disadvantages to the fee-for-service payment structure. Under fee-for-service plans, insured patients are at liberty to choose any physician, specialist, or hospital they wish. In addition, they do not require preauthorization for services or referrals for specialist care. It has been argued that fee-for-service systems provide superior customer service—patient access to healthcare providers is prompt and direct. In addition, fee-for-service systems preserve physician autonomy. Physicians are left alone to decide what care their patients should receive and what prices should be charged. Despite such advantages, fee-for-service coverage also has apparent disadvantages. The financial burden in fee-for-service systems is high. Patients have higher monthly premiums as well as higher outof-pocket expenditures. In addition, coverage only pays for reasonable and customary medical expenses. If healthcare providers charge more than the defined average in their area, patients must pay the difference. Fee-for-service systems also carry a significant paperwork burden. Patients or their healthcare providers must file claims for every insurance company reimbursement. Finally, it has been suggested that feefor-service structures create perverse incentives for physicians. Physicians have a financial incentive to overtreat their patients because they are paid for every service they provide. In addition, physicians profit from sicker patients needing more services and this inherently creates a disincentive for preventive care and health promotion. Advocates for fee-for-service and managed care systems are currently divided. However, both sides would undoubtedly agree that, as American Medical Association economist Carol Kane notes, “hopefully, as markets evolve and as we continue to learn about payment mechanisms, we will tend toward those arrangements where physicians are fairly and appropriately compensated for focusing on patient needs.” SEE ALSO: Health Maintenance Organization (HMO); In-
surance; Managed Care; Point of Service (POS); Preferred Provider Organization (PPO).
Bibliography. David M. Eddy, “Balancing Cost and Qual-
ity in Fee-for-Service versus Managed Care,” Health Affairs (v.16/3, 1997); Health, United States, www.ahcpr.gov (cited September 2006); Managed Care Magazine online, www.
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managedcaremag.com/archives/9904/9904.capvsffs.html (cited October 2006). Sangeeta Patel University of Illinois at Chicago College of Medicine
Female Circumcision Often used synonymously with the terms female genital cutting or female genital mutilation, female circumcision refers to the removal of any part of the female external genitalia for a nonmedical purpose. The United Nations and the World Health Organization prefer the term genital mutilation to emphasize the often negative health and sexual consequences for women who have undergone the procedure, as well as to draw a clear distinction between removal of female genitalia from removal of the male foreskin, a procedure which carries fewer negative health consequences. Female circumcision is a blanket term that refers to many related but distinct practices. Most involve removing at least some genital tissue, although in some instances, the ritual is symbolically simulated with a knife or needle but no tissue is removed. A clitoridotomy involves the removal or splitting of the clitoral hood; cliteridectomy means the partial or complete removal of the external part of the clitoris; and infibulation replaces the entire vulva with an intact layer of flesh from pubis to the anus, apart from a small hole for urine and menstrual blood. The labia are sewn together following excision and will heal as scar tissue. The opening is cut prior to childbirth and then resewn. Although performed by trained medical personnel in some locales, female circumcision is often performed without anesthesia and using nonsterile equipment, which can cause a great deal of bleeding and pain. Girls and women are prone to infection following the procedure, following sexual intercourse, and following childbirth. Infibulation can also cause infections due to blocked passage of urine or menstrual blood, sometimes leading to infertility. Female circumcision is often justified by citing religious texts or cultural norms, and is often carried out by females on their own younger relatives. Most human rights organizations deplore any form of female geni-
tal alteration, especially as it is often performed on girls too young to give consent, most commonly when they are aged between 4 and 8. Although the practice was legal in the United States until 1996, it is now illegal although still practiced clandestinely among some immigrant groups. Female genital alteration is still common in many countries, especially in the Middle East and Africa, where rates can exceed 95 percent. Views among people living in these countries are naturally quite variable, although a small but growing number of people are rejecting the practice for their own children. See
Also:
(WHO).
Infertility; World Health Organization
Bibliography. Rogaia Mustafa Abusharaf, ed., Female
Circumcision: Multicultural Perspectives (University of Pennsylvania Press, 2007); Ellen Gruenbaum, Female Circumcision Controversy: An Anthropological Perspective (Johns Hopkins University Press, 2000). Annie Dude University of Chicago
Fetal Alcohol Syndrome Fetal alcohol spectrum disorders are a continuum of alcohol-induced fetal malformations. The severe end of this spectrum is a specific pattern of malformations in the developing fetus termed fetal alcohol syndrome. The Centers for Disease Control and Prevention (CDC) estimates that the incidence of fetal alcohol syndrome in the United States is between 0.2 and 1.5 cases per 1,000 live births in the various regions of the country. The incidence of all fetal alcohol spectrum disorders is estimated to be several times higher still. The actual mechanism of embryonic and fetal malformation due to maternal alcohol consumption is not known. It is thought that alcohol or its by-products may interfere with placental transfer of essential minerals and amino acids. The incidence of the fetal alcohol phenotype is directly related to the level of alcohol exposure. Approximately 30 percent of infants born to heavy drinkers have congenital anomalies compared to approximately 15 percent of those born to moderate drinkers.
Fetal alcohol syndrome is characterized by abnormal facial features, growth deficiency affecting length, weight, and head circumference, and central nervous system anomalies including developmental delay, mental retardation, and attention deficit disorder. The characteristic faces of the infant or child with fetal alcohol syndrome includes a thin upper lip, short palpebral fissures (the space between the margin of the eyelids), and an abnormal philtrum (the midline groove between the upper lip and the nose). Associated malformations that are not required for diagnosis but are, nonetheless, frequently seen include cardiac defects, particularly of the septum, and minor limb and joint anomalies. Fetal alcohol syndrome is one of the leading causes of preventable birth defects and mental retardation. While affected children may benefit from special education initiatives and psychosocial support, there is no specific treatment for the syndrome. The syndrome is, however, 100 percent preventable by eliminating alcohol consumption during pregnancy. There is no known “safe” level of alcohol consumption during pregnancy and damage may occur during any trimester. All healthcare professionals should educate women of childbearing age regarding the deleterious effects of alcohol on their growing child and women who are pregnant should be specifically counseled to stop consumption of alcohol and be given appropriate support to do so. It is important for health professionals to not limit preventative interventions solely to the mother but to also recognize the role of fathers and other family members in preventing the occurrence of fetal alcohol syndrome. SEE ALSO: Alcohol Consumption; Birth Defects; Mental
Retardation.
Bibliography. Centers for Disease Control and Preven-
tion, “Fetal Alcohol Spectrum Disorders,” http://www.cdc. gov/ncbddd/fas/ (cited January 14, 2007).
Claire K. Nguyen Johns Hopkins Bloomberg School of Public Health
Fever Fever, or pyrexis, is a condition in which body temperature rises above the normal. Mild fevers are as-
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sociated with loss of liquid and chills, while more extreme fevers can lead to convulsion and even death. Generally, a fever is caused as a result of infection by virus or bacteria and results from the body’s natural ability to produce more pyrogens than normal and these affect the brain’s ability to detect temperature changes. It is possible that fever can be a beneficial response by the body to an infection and helps in resistance and recovery from it. However, this has not yet been fully established and some controversy surrounds the issue. Nevertheless, the elevated temperatures stimulate the production of white blood cells and may inhibit the growth of invading organisms. During the course of a typical day, the internal temperature varies little and generally remains within one or two degrees of its average of 37.2 degrees C in the mouth; increases in temperature beyond this range are, therefore, defined as fever and temperature rises of above 40.5 degrees represent severe fevers; should the temperature reach 42.2 degrees or higher, then a genuine threat of death exists. Mild fevers generally feature increased sweating and reduced blood and urine production. Although fever is generally associated with viral infection, it can also come about as a result of coronary trouble or in response to extreme physiological stress. In general terms, treating fever should be approached by treating the underlying causes of the fever, although this may be accompanied by measures to reduce any discomfort the patient might be feeling as a result of high temperature. Consequently, aspirin might be used as an antipyretic agent and other pharmaceuticals used to tackle the cause and nature of the infection or other cause. A wide range of conditions are referred to as a form of fever, not always accurately. The name of the fever generally relates to its cause; for example, Rift Valley fever is caused by the bite of mosquitoes in the Rift Valley of Kenya and subsequently more widely; meanwhile, blackwater fever is a form of malaria in which the urine turns black. Hay fever is a condition in which an allergic reaction to pollen or similar item leads to flu-like symptoms, although strictly speaking this is not a fever at all. In many parts of the world, fevers continue to represent a serious threat to health. Dengue fever, for example, and hemorrhagic fever kill tens of thousands of people annually. Increases
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Fever is caused as a result of infection by virus or bacteria and results from the body’s natural ability to produce more pyrogens.
in public health technical capacity and resources in affected countries would help to reduce these numbers. However, as climate change continues to cause migration of living creatures into different locations, vulnerability will spread beyond areas where those problems have previously been experienced. SEE ALSO: Dengue. Bibliography. Centers for Disease Control Division of
Vector-Borne Infectious Diseases (CDC-DVBID), “Dengue Fever Publications,” http://www.cdc.gov/ncidod/dvbid/pubs/dengue-pubs.htm (cited January 2007); Duane J. Gubler, “Dengue and Dengue Hemorrhagic Fever,” Clinical Microbiology Reviews (v.11/3, 1998). John Walsh Shinawatra University
Fiji Fiji is an island nation in the Pacific Ocean, west of Tonga and south of Tuvalu. The nation is comprised of 322 islands (106 of them inhabited) and 522 islets. Almost 90 percent of the population lives on the two main islands of Viti Levu and Vanua Levu. A popular tourist destination for nearly 500,000 people a year,
Fijians have seen cycles of economic stagnation and political turmoil over the past 30 years. The nation has endured four military coups in the past 20 years, the latest in 2006. The population is 906,000, making it the most populous of the South Pacific’s island nations. However, the annual rate of growth is just 1.4 percent, due to a low birth rate and increased emigration. Many of those who leave the island are Indo-Fijians, descendents of Indian workers brought in by the British during a century of colonization. Once Fiji won independence in 1970, native Melanesians began to pass exclusionary laws against those of Indian heritage. Today, many Indo-Fijians suffer from racial discrimination and unequal access to public services, including education. Despite an overall literacy rate of 93 percent, a 1996 survey showed that only 14 percent of Indo-Fijian woman and 8 percent of men had received formal education. Life expectancy rates have risen sharply since the 1960s, now standing at around 67 for males and 72 for females. Infant and child mortality has fallen to relatively low levels, with 16 infant deaths per 1,000 and 18 deaths per 1,000 for children aged 1–5. Mothers receive adequate prenatal care, and maternal mortality is rare. While a variety of communicable diseases have been brought under control since the 1960s, problems do remain. The figures are not complete, but the World Health Organization estimates that at least 25 percent of Fijians live below the poverty line. Clean water and sanitation is spotty in some areas. Most child deaths are caused by acute respiratory diseases, meningitis, parasitic diseases, and anemia. Noncommunicable, chronic lifestyle diseases such as diabetes and hypertension are also beginning to put an increasing burden on the health of Fijians. Like their island neighbors, Fijians have moved toward a more sedentary lifestyle and adopted a more westernized diet, leading to a rise in obesity levels. Smoking is also common. A 2002 survey indicated that the adult prevalence rate for diabetes was 12 percent, and the prevalence rate for hypertension was 19 percent. A third of all deaths in Fijians aged 40–59 were attributable to circulatory diseases. Unlike most of the Pacific Islands, Fiji has a human immunodeficiency virus (HIV)-positive population, with 219 reported cases as of December 2006. Because HIV testing in Fiji is voluntary, the virus could be much more widespread; the Ministry of Health estimates that up to 4,000 Fijians could be undiagnosed. Other sexu-
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ally transmitted diseases have also spiked up. Fiji contributes less of its Gross Domestic Product to total health expenditures than any Pacific nation, around 3 percent annually or $104 per capita. Little money has been allocated to hospital infrastructure or drug procurement. There are 24 general hospitals and 74 primary care centers to serve the population; the Ministry of Health counted 339 doctors, 1,682 nurses, and 1,435 other healthcare staff in 2003.
Social Impact As a chronic infection, lymphatic filariasis inflicts severe social problems upon its victims. People with the disease often suffer pain, disfigurement, and sexual disability. Communities frequently shun women and men disfigured by the disease, many of whom never marry or become rejected by spouses. Their families and communities are further affected as people disabled by the disease are frequently unable to work.
SEE ALSO: Healthcare, Asia and Oceania; Tonga; Tuvalu.
Prevention, Treatment, and Control Prevention and control measures against lymphatic filariasis include sleeping under mosquito nets, with or without insecticide treatment, and the use of mosquito repellents. However, given the long life cycle of the filarial worms, even these mosquito control efforts have failed at eradicating the disease. Thus, in 2000, the World Health Organization launched a global program to eliminate lymphatic filariasis by mass drug administration (MDA) of at-risk populations with medicines, including diethylcarbamazine, ivermectin, and albendazole, known to kill the worms. Such efforts have yielded promising results in endemic areas, such as in Egypt, where research suggests that filariasis can be eliminated after five rounds of MDA. The goals of this global campaign are to eliminate lymphatic filariasis as a public health problem and alleviate the social and economic hardships in individuals suffering from lymphatic filariasis-induced disability.
BIBLIOGRAPHY. Richard and Renee S. Katz, The Straight
Path of the Spirit: Ancestral Wisdom and Healing Traditions in Fiji, (Inner Traditions International, 1999); “Fiji,” World Health Organization, http://www.who.int/countries/fji/en/.
Heather K. Michon Independent Scholar
Filariasis/Elephantiasis Currently affecting at least 120 million people in over 80 countries, lymphatic filariasis has for thousands of years been a leading cause of permanent and long-term disability worldwide. Its primary form, called Wuchereria Bankcrofti, is transmitted between humans by the bites of infected mosquitoes, mainly Anopheles and Aedes species in endemic parts of Africa and Asia, respectively. People living in areas of poor sanitation, where mosquitoes often breed, are at high risk for infection. Biological Impact Lymphatic filariasis is caused when several, threadlike parasitic worms invade the human lymph system, which fights infections and regulates the body’s fluid balance. The microscopic worms live in the lymph vessels for five to seven years, often causing permanent damage. An impaired lymph system results in the swelling of arms, legs, and even genitals, often to several times the normal size, usually termed lymphedema. Lymphedema makes it difficult to fight infections and those affected typically have severe fungal and bacterial diseases that thicken and harden the skin, which is called elephantiasis.
SEE ALSO: Healthcare, Africa; Healthcare, Asia and Ocea-
nia; Lymphatic Diseases; Parasitic Diseases.
Bibliography. Division of Parasitic Diseases at the Cen-
ters for Disease Control and Prevention, “Lymphatic Filariasis,” www.cdc.gov/Ncidod/dpd/ (cited October 2006); The Global Alliance to Eliminate Lymphatic Filariasis, “Global Alliance History,” www.filariasis.org (cited October 2006); R.M. Ramzy, et al., “Effect of Yearly Mass Drug Administration with Diethylcarbamzine and Albendazole on Bancroftian Filariasis in Egypt: A Comprehensive Assessment,” Lancet (v.367/9515, 2006). Rajesh Panjabi, MPH Department of Medicine, University of North Carolina–Chapel Hill Johns Hopkins School of Public Health
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Finland
Finland With a per capita income of $31,000, Finland is the 22nd richest nation in the world. The government provides a strong safety net; and according to the United Nations Development Programme’s (UNDP) Human Development Report, Finland has the 11th highest standard of living. Income is relatively well distributed, and Finland is ranked 26.9 percent on the Gini index of inequality. The richest 10 percent of the population holds 21.6 percent of the country’s wealth while the poorest 10 percent share 4.2 percent. Poverty is virtually nonexistent in Finland, but the government has been forced to deal with persistent unemployment (currently 8.4 percent). Municipalities are responsible for providing health insurance in Finland, and local governments may choose to provide coverage themselves or to join municipal boards or turn to outside agents. As the aging population expands, government resources have become strained. Consequently, families and communities have taken on a greater share of the responsibility for caring for the elderly. While most Finns enjoy easy access to healthcare, people who live in remote areas are sometimes cut off from health services. The government addressed this need in a 2003 report, which introduced a plan in which central and municipal governments work with nongovernmental organizations (NGOs) to make healthcare affordable and accessible to all Finns. Targeted areas included restructuring the healthcare system and strengthening financing methods. Long-term health goals were laid out in Health 2015, which encouraged healthier lifestyles across the population. Goals for different age groups were established such as improving women’s and children’s health, curtailing alcohol and drug abuse among adolescents, slashing the rate of accidental and violent deaths among adult males, and meeting the needs of the aging population. Finland spends an average of 3 percent of the total budget on health care. At present, 7.4 percent of the Gross Domestic Product (GDP) is designated for healthrelated programs, with $2,108 (international dollars) allotted per capita. The government provides 76.5 percent of all healthcare expenditures, and 21.5 percent of that amount is earmarked for social security. Social security in Finland covers the elderly, the disabled, and survivors. The system is financed by workers (4.4 percent of earn-
Finland is the 22nd richest nation in the world with a per capita income of $31,000.
ings), the self-employed (21.1 percent of earnings), and employers (from 1.3 to 4.45 percent of payroll) and supplemented by the government. The private sector furnishes 23.5 percent of total healthcare expenditures, and 81.20 percent of private funding is derived from out-ofpocket expenses. There are 3.16 physicians, 14.33 nurses, 0.76 midwives, 1.28 dentists, and 1.12 pharmacists per 1,000 population in Finland. The population of 5,231,372 enjoys a life expectancy of 78.5 years, the 39th highest in the world. Women outlive men an average of seven years. Literacy is universal in Finland, and all of the relevant population attends primary and secondary school. All Finns have sustained access to safe drinking water and improved sanitation. The use of birth control is widespread (77 percent), and Finnish women give birth at a rate of 1.73 children each. All births are attended by trained personnel, and all new mothers receive antenatal care. The adjusted maternal mortality rate of six deaths per 100,000 live births is among the lowest in the world. Finland has the sixth lowest infant mortality rate among the world’s nations at 3.55 deaths per 100,000 live births. Between 1990 and 2004, infant mortality was cut in half, dropping from six to three deaths per 1,000 live births. At the same time, mortality for children under the age of five fell from seven to four deaths per 1,000 live births. Although Finnish children are remarkably healthy, four percent of infants are underweight at birth. Immunization rates are predictably high, and 98 percent of infants are immunized against diphtheria,
Flea Bites
pertussis, and tetanus (DPT1 and DPT3) and tuberculosis; 97 percent against measles; and 96 percent against polio and Haemophilus influenzae type B. HIV/AIDS does not present a major problem in Finland, and the current adult prevalence rate is less than 0.1 percent. Around 1,500 people are living with the disease, and it has proved fatal to less than 100. In May 2000, meningococcal disease was identified in Finland, and the country experienced outbreaks of influenza in 2003 and 2004. Severe acute respiratory syndrome (SARS) surfaced in spring 2003. The leading causes of death in Finland are cardiovascular disease, alcoholism-related conditions, and accidents. High cholesterol and obesity are also of grave concern. See Also: Childhood Immunization; Obesity. Bibliography. Central Intelligence Agency, “Finland,”
World Factbook www.cia.gov/cia/publications/factbook/ geos/fi.html; Commission on the Status of Women, “Finland” www.un.org/womenwatch/daw/Review/responses/ FINLAND-English.pdf (cited April 2007); Spencer Di Scala, Twentieth Century Europe: Politics, Society, Culture (McGraw-Hill, 2004); Sandra Halperin, War and Social Change in Modern Europe: The Great Transformation Revisited (Cambridge University Press, 2004); Martin A. Levin and Martin Shapiro, eds., Transatlantic Policymaking in an Age of Austerity: Diversity and Drift (Georgetown University Press, 2004); Jeremy Rifkin, The European Dream: How Europe’s Vision of the Future Is Quietly Eclipsing the American Dream (Jeremy P. Tarcher/Penguin, 2004); Social Security Administration, “Finland” www.ssa.gov/policy/docs/progdesc/ssptw/2002-2003/europe/finland.html (cited April 2007); Eric Solsten and Sandra W. Meditz, Finland: A Country Study (Federal Research Division, LOC, 1990); Peter Taylor-Gooby, New Risks, New Welfare: The Transformation of the European Welfare State (Oxford University Press, 2004). Elizabeth R. Purdy, Ph.D. Independent Scholar
Flea Bites A flea bite is the resulting injury from a flea sting, which could produce a local inflammatory reaction, or after an incubation period, a flea-borne disease,
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such as plague, endemic typhus fever, dipylidiasis, and hymenolepiasis, among others, but most species of flea do not transmit pathogens. Fleas belong (taxonomically) to the order Siphonapetra, with two important families for human and animal health: Pulicidae and Tungidae. The above-mentioned diseases are transmitted by members of family Pulicidae (Pulex, Ctenocephalides, and Xenopsylla). In history, Xenopsylla cheopis represented the most important vector of an ancient disease previously known as the Black Death (plague), one of the worst natural disasters in history. Plague or Black Death is an infection of rodents caused by Yersinia pestis and accidentally transmitted to humans by the bite of infected fleas. Plague has three forms: bubonic plague (infection of the lymph glands), septicemia plague (infection of the blood), and pneumonic plague (infection of the lungs). Pneumonic plague can spread from person to person. Fortunately, this disease is treatable with antibiotics if detected early. Prevention consists of controlling rodent fleas, educating the public and the medical community in places where plague occurs, and using preventive medicines and vaccines as appropriate. Endemic typhus fever or typhus (also called fleaborne typhus and murine typhus) is a disease caused by small bacteria called Rickettsia. Dipylidiasis is a common tapeworm infection of dogs and cats caused by Dipylidium caninum. Arthropods serve as intermediate hosts for this parasite, including then the fleas which include the dog flea (Ctenocephalides canis), the cat flea (C. felis), and the dog louse (Trichodectes canis). The risk to human beings to acquire this disease is low, because this occurs by ingestion of arthropod intermediate hosts which harbor the cysticercoid larvae. The hymenolepiasis, caused by the dwarf tapeworm or Hymenolepis nana, is the most common tapeworm infection diagnosed in the world. Although it is not the most common form of transmission, fleas could vectorize this disease in animals and may be in humans. People get infected by accidentally ingesting tapeworm eggs, by ingesting fecally contaminated foods and water, by touching the mouth with contaminated fingers, or by ingesting contaminated soil. Another important infection directly caused by fleas is the tungiasis which is a common health problem in economically depressed communities in South American and sub-Saharan African countries,
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but it should be considered in the increasing number of international travelers to tropical destinations. The causative ectoparasite, Tunga penetrans (a flea of approximately 1 millimeter of size), penetrates into the skin of its host, undergoes a peculiar hypertrophy, expels several hundred eggs for a period of less than three weeks, and eventually dies. Besides the human, this flea could infect cattle, sheep, and horses. SEE ALSO: Medical Entomology; Medical Helminthology;
Parasitic Diseases; Tick Bites.
Bibliography. Harold Brown, Clinical Parasitology (Ap-
pleton-Century-Crofts, 1983); Albert Camus, The Plague (Penguin, 1970); Gordon Cook and Alimuddin Zulma, Manson’s Tropical Diseases (Saunders, 2003); Hermann Feldmeier, “Severe Tungiasis in Underprivileged Communities: Case Series from Brazil,” Emerging Infectious Diseases (v.9/8, 2003); Becerri Flores and Romero Cabello, Medical Parasitology (McGraw-Hill, 2004); David Heymann, Control of Communicable Diseases in Man (APHA/ PAHO/WHO, 2004). Alfonso J. Rodriguez-Morales, M.D., M.Sc. Universidad de Los Andes, Venezuela Carlos Franco-Paredes, M.D., M.P.H. Emory University
Fluoride Fluoride is the ionic form of the element fluorine, and there are organic and inorganic compounds containing fluorine which form fluorides. Some of these are found naturally in low concentrations in drinking water and in tea and other foods, and indeed, the ocean itself has an average concentration of fluoride compounds of 1.3 parts per million. In industry, hydrofluoric acid is used for the etching of glass and also for the making of integrated circuit boards and other industrial applications. However, generally, in terms of healthcare, it is used to deal with prevention of tooth decay. In a very concentrated form, it can be a prescription drug as a part of drug molecules to resist the detoxification in the liver by the Cytochrome P450 oxidase.
Fluoride has been used for a long time in the treatment of teeth to prevent tooth decay, and is found in toothpaste. In 1951, Joseph C. Muhler and Harry G. Day of Indiana University reported that their research on stannous fluoride was an effective means of preventing tooth decay, and the university sold the research findings to Procter & Gamble who started using it in their Crest® toothpaste. Nowadays, fluoride is found in most toothpastes, and it is possible to use fluoride although care must be taken not to use too much, otherwise dental fluorosis could occur through overexposure. In addition, there has been much debate over water fluoridation with some parts of the world introducing it into water supplies to help reduce the level of tooth decay in children. This has led to widespread debate around the world with the World Health Organization and the American Dental Association recommending increasing the level of fluoride in water to between 0.7 and 1.2 parts per million. Opponents of water fluoridization claims that an increase in fluoride could weaken the human immune system, and this could lead to increased prevalence of certain diseases and disorders. However, most international health service agencies recognize that the benefits involved in the prevention of dental decay hugely outweigh the concerns that some people have expressed regarding the side effects. Articles on the role of fluoride and it possible side effects have been published in the British Medical Journal and also in forums such as The Journal of Fluorine Chemistry. This has not stopped politicians in many countries opposing the fluoridization of water, some of which involved several marathon debates in the British House of Commons, the latest of which was in November 2003. SEE ALSO: Dental Health. Bibliography. L. L. Demos, et al., “Water Fluoridation,
Osteoporosis, Fractures—Recent Developments,” Australian Dental Journal (v.46/2, 2001); M.S. McDonagh, et al., “Systematic Review of Water Fluoridation,” British Medical Journal (v.321, 2000); G.M. Whitford, “Fluoride in Dental Products,” Journal of Dental Research (v.66/5, 1987).
Justin Corfield Geelong Grammar School, Australia
Folic Acid Folic acid, whose chemical name is pteroylmonoglutamic acid, was first isolated in 1945. Folic acid is B vitamin found in leafy greens, animal proteins, fruits, and vegetables. Humans absorb this vitamin from the proximal small intestine and store folate primarily in the liver and red blood cells (RBCs). Folate is indirectly responsible for the synthesis of DNA. Many etiologies exist for folate deficiency including infection, pregnancy, malabsorption/starvation syndromes, certain cancer medications, and antibiotics. With low levels of folic acid, RBCs tend to enlarge in volume, a term known as macrocytosis. With this enlargement, RBCs are not able to routinely carry enough oxygen to tissues creating a scenario known as megaloblastic anemia. Megaloblastic anemia can be diagnosed by measuring the mean volume of RBCs, examining peripheral blood smears of RBCs, measuring serum folate levels, and by examining bone marrow. Another major cause of megaloblastic anemia is vitamin B12 deficiency. The distinction between the two disease states is important in terms of treatment. If the cause of the anemia is due to vitamin B12 deficiency, increasing the dietary folate levels may improve the anemia temporarily but will not prevent the neurologic decline that occurs with vitamin B12 deficiency. Similarly, in the case of malabsorption syndromes, increasing the folate intake will not improve the ultimate source of the vitamin loss. Among the general public, folic acid is most well known for its importance in preventing neural tube defects (NTDs). The incidence of these ailments affecting proper development of the brain and spinal cord are significantly reduced by as much as 70 percent with the minimum daily dietary intake of 400 μg. The mechanism by which folate is able to prevent NTDs is not completely understood and the involvement in NTD development is possible even in the first week of pregnancy when a woman may be unaware she is pregnant. Thus, all women of childbearing age are especially encouraged to incorporate folic acid into their diets. In the United States, most flour and grain products are supplemented with folic acid in order to decrease the number of infants born with NTDs; however, supplementation in European or Australian countries is not required and has become a topic of controversy. Pregnant women are encouraged to maximize their
Fondation Jean Dausset (CEPH)
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dietary intake of folic acid; however, more than 1,000 μg daily affords no additional benefits and any adverse effects at this dosage have not yet been elucidated. The U. S. Department of Health and Human Services encourages dietary intake of folic acid through fortified dry cereals, supplements, or by eating fruits and vegetables high in folic acid. Folic acid is being examined in the cardiovascular arena with studies showing a promise of improved heart health, a decreased incidence of stroke, and a decrease in congenital heart defects. SEE ALSO: Anemia; Neural Tube Defects; Vitamin and
Mineral Supplements.
Bibliography. Centers for Disease Control and Preven-
tion, “The Basics about Folic Acid,” www.cdc.gov (cited November 2005); Centers for Disease Control and Prevention, “Folic Acid Now,” www.cdc.gov (cited November 2005); M. Tarek Elghetany and Katalin Banki, Henry’s Clinical Diagnosis and Management by Laboratory Methods: Erythrocytic Disorders (Saunders, 2006); L.L.M. Lindsey, et al., “Use of Dietary Supplements Containing Folic Acid among Women of Childbearing Age,” Morbidity and Mortality Weekly Report (v.54/38, 2005); National Women’s Health Information Center, “Folic Acid—Frequently Asked Questions,” www.womenshealth.gov (cited January 2005); Edward Reynolds, “Vitamin B12, Folic Acid, and the Nervous System,” Lancet (v.5, 2006). Stephanie F. Ingram University of South Florida College of Medicine
Fondation Jean Dausset (CEPH) Founded in 1984 as the Centre d’Etude du Polymorphisme Humain (CEP), this foundation was renamed the Fondation Jean Dausset in 1993. Dausset, a worldrenowned scientist, won the Nobel Prize in Physiology or Medicine in 1980. Since its inception the foundation has developed essential tools in the genetic and physical mapping of human chromosomes. During the 1990s the foundation began concentrating on polyfactorial diseases, making a significant contribution to the understanding of the etiology of
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inflammatory bowel maladies. Through a positional cloning strategy the foundation succeeded in identifying three mutations in a new gene that increases the susceptibility to Crohn’s disease. The foundation is also involved with a large international consortium concentrating on research for susceptibility genes for breast and prostate cancer. In 1991, the Foundation, along with the French Muscular Dystrophy Association, created the Généthon, a nonprofit research institute, in order to provide tools to the scientific community for the localization and cloning of disease determining genes. The Fondation Jean Dausset is headquartered in Paris, France, and each year sponsors a number of meetings and seminars related to the organization’s mission. See Also: Breast Cancer; Gene Mapping; Prostate Can-
cer; Muscular Dystrophy.
Bibliography. Association Française Contre les Myopa-
thies (AFM), www.afm-france.org (cited October 2006); Fondation Jean Dausset (CEPH), www.cephb.fr (cited October 2006). Erin Fitch Independent Scholar
Food Allergy A food allergy, or hypersensitivity, is an exaggerate immunological response to a food that can cause symptoms from tingling lips to difficulty breathing and life-threatening anaphylaxis. The prevalence of food allergies has been estimated to be around 1 to 3 percent in adults and 4 to 6 percent in children and rising, and more than 70 foods have been reported as causing food allergies. There is no current treatment for food allergies, and avoidance of the causative food is the only recommended prevention method. Access to care is crucial with food allergy; without it, the reaction can lead to inflammation of the airways, restricted breathing, and subsequent death. Many food allergies begin in childhood. Children develop allergies in order of their exposure to the causative agent, so food allergies begin when food
is introduced into the diet. Food allergy can develop from a combination of genetic factors and environmental exposures, as part of overall atopy, a genetic predilection toward overreactive immune responses against harmless environmental exposures. Many people outgrow their food allergies, although many of the most serious allergies are lifelong. Food allergies are not the same as intolerance, which can cause abdominal cramping, but is not associated with an allergic response mediated by immunoglobulin E (IgE). The most common foods that trigger food allergies are eggs, fish, peanuts, soybeans, milk, tree nuts, gluten, and shellfish/crustaceans, and it is usually a protein in the food that acts as the allergen. Because foods that trigger allergy depend on exposure, food allergies vary across the world. In central Europe, allergy to celery is common, whereas east Asia has a substantial population with rice allergy. As in any other allergic reaction, a person must be previously sensitized to the particular allergen, so that the immune system is able to identify and memorize a specific molecular “footprint” for each allergen. On encountering the allergen for the first time, IgE is produced. Once IgE has been synthesized, a second exposure to the allergen induces IgE to cause release of many inflammatory molecules. The signs and symptoms of an allergic food reaction can include tongue swelling, hives, difficulty breathing, vomiting, diarrhea, eczema, sudden decrease in blood pressure, loss of consciousness, and death. Most symptoms are classified according to the organ system they affect. Gastrointestinal signs can include vomiting, pain, or diarrhea and can develop rapidly after consumption of the allergen. Oral allergy syndrome is a result of cross-sensitivity to foods that also cause allergic rhinitis in the individual; it manifests as itchy, swelling lips and tongue. Atopic dermatitis, or eczema, can be caused by food allergy, as can hives and angioedema, or deep tissue inflammation. The most severe result of food allergy is anaphylaxis. The annual incidence of anaphylactic reactions is about 30 per 100,000 persons, and individuals with asthma, eczema, or hay fever are at greater relative risk of experiencing anaphylaxis. There are other causes of anaphylaxis besides food allergy, including medication allergy, insect stings, and latex, but foods
Food and Agriculture Organization of the United Nations (FAO)
are a common cause of anaphylaxis. Anaphylaxis is a systemic reaction that can affect several organ systems at the same time and can be life threatening without immediate treatment. An anaphylactic reaction may begin with a tingling or itching sensation in the mouth, and progress to hives, swelling of the mouth and throat area, difficulty breathing, vomiting, diarrhea, abdominal cramping, and loss of consciousness. The main treatment for an anaphylactic food response is injection with epinephrine or adrenaline. This can be self-administered with an EpiPen®, which is designed to inject a controlled amount of drug. The epinephrine constricts the swollen blood vessels and decreases inflammation, to decrease hives, tongue, throat and airway constriction, and to restore normal blood pressure. In the case of those with milder symptoms, food allergies can be difficult to detect. The timing of a reaction can be delayed due to the digestive process, and a detailed food diary can help in detecting the timing of reactions, as well as the amount of food that triggers them, and the duration and severity of symptoms. An elimination diet, in which one particular food is eliminated in order to see if the existing reaction (eczema, hives, respiratory difficulty) resolves, is a good way to confirm suspected food allergens. Other options for diagnosis, where allergists are present, include a skin prick test or oral challenge. In a skin prick test, small amounts of common allergens are scratched onto the skin and a red, itchy wheal will develop within minutes to indicate the specific allergens for that person. An oral challenge, which should only be undertaken under medical supervision, consists of feeding the suspected food and waiting for a reaction. In the case of anaphylactic reactions, oral challenge is not a good idea, especially in areas unequipped to treat severe allergic reactions. Because there is no prevention method analogous to allergy shots and respiratory allergies for food allergies, those with food allergies are advised to avoid their triggering food(s) at all costs. If labels are present on foods, these should be read and screened against the allergy. If no labels are available, one should avoid the food or contact the manufacturer for more details of its contents. In a resource-poor environment, where food labels and available epinephrine are rare, food allergies can be especially deadly.
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SEE ALSO: Allergy. Bibliography. Food Allergy and Anaphylaxis Network
(FAAN), www.foodallergy.org; World Health Organization International Food Safety Authorities Network, “Food Allergies,” www.who.int/entity/foodsafety/fs_management/ No_03_allergy_June06_en.pdf (cited April 28, 2007). Erin Fitch Oregon Health and Science University
Food and Agriculture Organization of the United Nations (FAO) Founded in 1945, the Food and Agriculture Organization of the United Nations (FAO) leads international efforts to defeat hunger throughout the world. Serving both developed and developing countries, the FAO acts as a neutral forum where all nations meet on an equal footing to negotiate agreements and debate policy. The organization also serves as a source of information related to world hunger and global agricultural issues. It helps developing and transitional countries modernize and make improvements in agriculture, forestry and fisheries to ensure optimum production with an emphasis on nutrition. Since its inception, the organization has focused special attention on rural areas, which are home to almost three-quarters of the world’s poor and hungry. In general terms, the FAO’s goals revolve around making sure that the world’s population has regular access to enough quality to lead active, healthy lives. The organization is charged with raising levels of nutrition, improving agricultural production and contributing to the overall growth of the world economy. As part of its mission, the FAO serves as an ever-expanding information network, calling on the expertise of its staff, including agronomists, foresters, fish and livestock specialists, social scientists, nutritionists, economists and statisticians, to collect, analyze and impart data. The organization also lends its years of experience to member countries in devising agricultural policy, supporting, planning and drafting effective legislation, and creating national strategies to alleviate hunger in impoverished areas. With regard to
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practical application, the organization promotes and maintains thousands of field projects around the world and manages millions of dollars contributed in large part by industrialized nations, development banks and private sources. In crisis situations, the FAO works with the World Food Program and other humanitarian agencies to help protect the livelihoods of individuals living in rural areas. The FAO also sponsors a variety of publication and produces a number of annual reports in various areas related to food production, world hunger, and the status of FAO projects. The FAO is governed by the Conference of Member Nations, which meets every two years to review the activities of the organization and approve the appropriate budgets. The conference elects a director general and governing council, which acts as a general governing body between Conference gatherings. The FAO is divided into eight departments: Administration and Finance; Agriculture; Biosecurity, Nutrition and Consumer Protection; Economics and Statistics; Fisheries; Forestry; General Affairs and Information; and Sustainable Development and Technical Cooperation. The organization maintains an international headquarters in Rome as well as a number of regional, subregional, and country offices and employs more than 3,700 individuals. In the 1990s, the FAO underwent significant restructuring to cut costs and decentralize its operation. This effectively increased the organizations emphasis on food security and focus on developing and transition nations while it increased interaction with the private sector. See Also: Food and Drug Administration (FDA); World
Health Organization (WHO).
BIBLIOGRAPHY. Ethics Update: World Hunger, ethics.
acusd.edu/Applied/WorldHunger/index.asp (cited September 2006); European Public Health Alliance, www. epha.org (cited September 2006); Food and Agriculture Organization of the United Nations, www.fao.org (cited September 2006); United Nations World Food Program www.wfp.org/english (cited September 2006); World Health Organization, www.who.int/en (cited September 2006). Ben Wynne, Ph.D. Gainesville State College
Food and Drug Administration (FDA) The United States Food and Drug Administration (FDA) is responsible for guaranteeing the safety of food, drugs, cosmetics, biological products, and medical devices and in monitoring the labels on these products to make sure that manufacturers do not make false or misleading claims about their contents. FDA activities are divided into new product reviews, product use and risk monitoring, ensuring safe manufacturing and handling, enforcing FDA standards, and conducting relevant research. The history of the FDA began in 1862 when President Abraham Lincoln named Charles M. Wetherill to head the Chemical Division of the newly established Department of Agriculture. In 1901, the Bureau of Chemistry was established and was subsequently charged with implementing the provisions of the Federal Food and Drugs Act of 1906, which Congress had passed in response media and public crusading. The Food, Drug, and Insecticide Administration was founded in 1927 as a regulatory agency of the Bureau of Chemistry. By 1930, the agency had become known as the Food and Drug Administration. Congress enacted the landmark Food, Drug, and Cosmetic Act in 1938, which still forms the statutory foundation of FDA activities. The Act was designed to ensure the safety of drugs, therapeutic devices, and cosmetics before they were marketed, establish food standards, and authorize the FDA to conduct factory inspections. In 1940, the FDA was transferred to the Department of Health, Education, and Welfare (HEW) and was incorporated into the Public Health Service branch of HEW in 1968. In 1980, the Department of Education assumed independent status, and HEW became the Department of Health and Human Services (HHS). Over time, the FDA was given responsibility for testing insulin and antibiotics, regulating chemical pesticides and food and color additives, establishing distinctions between prescription and over-the-counter (OTC) drugs, regulating drug efficacy, monitoring manufacturing processes, controlling prescription drug advertising, regulating biological therapeutic agents, and monitoring nutrition labeling. In the 21st century, FDA priorities are focused on mitigating public health risks, improving the
quality of information available to consumers, enhancing postmarketing safety, strengthening the ability of the agency to prepare for potential terrorist attacks, responding to any attacks that occur, and recruiting the best possible experts to carry out the agency’s mission. The FDA considers its main focus to be on protecting public health through ensuring that safe and effective products are not unnecessarily delayed in reaching the public, monitoring in-use products for safety, and supplying accurate, science-based information in the interests of public health. The FDA’s most visible role from a public perspective is in verifying products, which include foods, medical and surgical devices, drugs, and consumer and medical products that emit radiation. Decisions are frequently made on a benefits-versus-risks basis, and the methods that the FDA uses to evaluate items are flexible according to the product under review. Eighty percent of all food consumed by Americans is monitored by the FDA, including half of all seafood and more than a fifth of fruits and vegetables sold across the country. The FDA monitors four million food imports each year. Foods are checked for contaminants, and additives are examined for safety. Infant formulas, medical food, and dietary supplements come under the auspices of the FDA, but ensuring the safety of meat and poultry products is the responsibility of the United States Department of Agriculture (USDA). The FDA shares the responsibility for regulating water with the Environmental Protection Agency (EPA), with the FDA monitoring the safety and labeling of bottled water and the EPA monitoring and protecting all other water sources. Drugs that are used for treatment and prevention of disease in both humans and animals and medical devices that range from tongue depressors and thermometers to pacemakers and dialysis machines must pass FDA tests that demonstrate safety and effectiveness. Biologics such as vaccines, blood products, and gene therapy are also vetted for safety and effectiveness. Products such as X-ray machines and microwave ovens are evaluated according to performance standards. Cosmetics and dietary supplements may reach the public without FDA approval. However, the agency may remove products that are deemed to be unsafe or fine manufacturers whose labels are discovered to be misleading or inaccurate.
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The FDA employs around 9,000 workers, including biologists, chemists, physicians, biomedical engineers, pharmacologists, veterinarians, toxicologists, public health and communication specialists, administrators, and support personnel. Product reviews and regulatory policy are the responsibility of the Washington staff, and field employees are generally engaged in inspection, surveillance, laboratory research, and educating the public and industries about safety and effectiveness. The national headquarters of the FDA is located at 5600 Fishers Lane, Rockville, Maryland 20857. Information on the agency is available by telephone (1-301-4436367) or over the internet (http://www.fda.gov/). Part of the public health responsibility of the FDA is to provide consumers with informational resources. Consequently, FDA publications include FDA Consumer, which offers up-to-date health news and articles of interest on a bimonthly basis, and a plethora of brochures and fact sheets. These publications may be obtained from FDA offices, on the agency Web site, or by telephone. Periodic public service announcements and press releases also keep the public informed about ongoing issues of concern to consumers. The FDA History Office is responsible for maintaining administration history through records, data, and oral accounts. This office houses the FDA museum, which boasts a variety of exhibits ranging from a box of Pilsbury blueberry pancake mix that contained no blueberries to Lady Ample bust developers, which failed to deliver on their promise. Less whimsical exhibits include samples of thalidomide, which caused a myriad of deaths, injuries, and birth defects in the early 1960s and Lash Lure, which blinded users in the 1930s. See Also: Food Contamination/Poisoning; Food Safety. Bibliography. Stephen J. Ceccoli, Pill Politics: Drugs and
the FDA (Lynne Rienner, 2004); Fran Hawthorne, Inside the FDA: The Business and Politics behind the Drugs We Take and the Food We Eat (Wiley, 2005); Food and Drug Administration, http://www.fda.gov/; Jeanne Herzog, Recurrent Criticisms, A History of Investigations of the FDA (University of Rochester Medical Center, Center for the Study of Drug Development, 1977); Robert Higgs, Hazardous to Our Health? FDA Regulation of Health Care Products (Independent Institute, 1995); Sandra A. Hoffmann and Michael Taylor, eds., Toward Safer Food: Perspectives on Risk
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and Priority Setting (Resources for the Future, 2005); Stanley T. Omaye, Food and Nutritional Toxicology (CRC Press, 2004); Barbara Rasco and Gleyn E. Bledsoe, Bioterrorism and Food Safety (CRC Press, 2005). Elizabeth R. Purdy, Ph.D. Independent Scholar
Food Contamination/ Poisoning Food contamination or poisoning covers any disease of an infectious or toxic nature caused by the consumption of food or water. It includes cases caused by chemical contamination as well as those caused by microbes and their toxins, or any other case where harm can be done by consuming unsafe food or water. Despite the huge developments in food production, processing, distribution, and preparation, reflecting concerns with food safety, not all populations have access to safe food and water. Nowadays, this situation is still responsible for many cases of disease and a considerable number of deaths, particularly in developing countries. Although the exact numbers are difficult to calculate, the World Health Organization (WHO) estimates unsafe food causes approximately 1.5 billion annual cases of diarrhea in children, resulting in an estimated 2.1 million deaths from diarrhea worldwide, most of them caused by contaminated food and/or water. According to the second United Nations (UN) World Water Development Report, almost one-fifth of the world population (1 billion people) does not have access to safe drinking water. This issue is a reemerging public health problem as new foodborne disease threats occur, caused by a number of reasons. These include the current globalization as international travel and trade is flourishing, microbial adaptation, and changes in the food industry, as well as the changes in human demographics and lifestyle. Contamination generally has a negative impact on the quality of food and may imply a risk to human health; therefore, close monitoring of this situation is vital. Surveillance of foodborne disease is a fundamental component of food safety systems, particularly in developed countries. Surveillance data can be used
for planning, implementing, and evaluating public health policies. These tasks can accomplish a further development of the health of consumers, while cooperating with the food industry, which has known massive developments during the last few years. The new food and water processing techniques need to be assessed for their safety. This has created very strict regulations worldwide, thus causing severe restrictions in international commerce and some tension between exporting and importing countries. There are many aspects connected with food contamination, and those may include chemical, microbiological, and radiological contaminations. There are several sources of contamination by chemical hazards: environmental pollution of the air, water, and soil, such as the case with toxic metals and dioxins, or the intentional use of various chemicals, such as pesticides, animal drugs, and other agrochemicals. Current policy has set acceptable levels of intake of certain compounds, thus ensuring food safety. Even so, there are several naturally occurring toxins, such as mycotoxins, marine biotoxins, cyanogenic glycosides, and toxins occurring in poisonous mushrooms, which periodically cause severe intoxications. Other chemicals frequently involved in food contamination are dioxins and polychlorinated biphenyls (PCBs). Dioxins are unwanted by-products of some industrial processes and waste incineration. On the other hand, metals such as lead and mercury can cause neurological damage in infants and children. Exposure to cadmium can also cause kidney damage, usually seen in the elderly. If preliminary toxicological evaluations and/or exposure estimates suggest that adverse health effects might be expected in the population, and the risk becomes sufficiently characterized, various management options may be considered, including the establishment of Codex Alimentarius standards. Foodborne illness caused by microorganisms is considered a large and growing public health problem. Bacteria-related food poisoning is the most common, but fewer than 20 of the many thousands of different bacteria are actually the culprits. More than 90 percent of the cases of food poisoning each year are caused by Staphylococcus aureus, Salmonella, Clostridium perfringens, Campylobacter, Listeria monocytogenes, Vibrio parahaemolyticus, Bacillus cereus, and entero-pathogenic Escherichia coli. These bacteria are
commonly found in many raw foods. Normally, a large number of food-poisoning bacteria must be present to cause illness. Therefore, illness can be prevented by controlling the initial number of bacteria present, preventing the small number from growing, destroying the bacteria by proper processing, and avoiding recontamination. With globalization and the thorough use of antibiotics, microorganisms are traveling faster and resulting in much more resistance, creating big problems in the control of these diseases. Recent outbreaks of H5N1 avian influenza in poultry in Asia and, more recently, in Europe and Africa, have quickly raised awareness about new sources of infection and the risk to humans from various exposures. The vast majority of cases reported are connected with direct contact with infected poultry and airborne transmission. Although there is a possibility that the virus could also spread to humans through consumption of contaminated poultry products, so far, there is no scientific evidence that eating properly cooked food can be responsible for contamination of humans with avian influenza. In the last years of the 20th century, bovine spongiform encephalopathy (BSE), more commonly known as mad cow disease, was making headlines on a daily basis. This fatal, neurodegenerative disease in cattle is caused by the accumulation of a misfolded cellular protein, and is also thought to be the cause of variant Creutzfeldt-Jakob disease (vCJD), a human brainwasting disease. The misfolded protein accumulates in the central nervous system and is responsible for a rapidly progressive dementia and some patients manifest a cerebellar ataxia. The discovery of this new model of infection mechanism entitled Dr. Stanley Prusiner the 1997 Nobel Prize for Medicine. Recent concerns have arisen concerning radioactivity, which has always been around and exists naturally in the atmosphere, soil, seas, and rivers. It is also created by human activity during energy production and military operations. Inevitably, some of this radiation contaminates food. Being invisible, tasteless, and not mentioned on food labels, it is frequently overlooked, but levels in food are strictly monitored and controlled. Contamination from nuclear contamination from radionuclides is still a particularly present problem in Chernobyl, more than 20 years after the nuclear reactor exploded. Close monitoring of radioactivity in
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products coming from that region is usual and, for instance, in dairy products, special attention is being taken to ensure that the amount of radioactivity is compliant with government regulations. In order to monitor the quality and safety of food and water, frequent analysis of different components, including elements (toxic and nutrient), pesticide residues, industrial chemicals, volatile organic compounds, and radionuclides, must be performed. These analyses are costly and often have economical sanctions should an abnormal value be found. This has led to strong opposition from the food industry and heavier restrictions on worldwide trade. There have been several efforts to implement worldwide policies to prevent disease attributable to unsafe food or water. These policies cover the entire food chain from production to consumption and will make use of different types of expertise, including strengthening food safety systems, promoting good manufacturing practices, and educating retailers and consumers about appropriate food handling. Education of consumers and training of food handlers in safe food handling is one of the most critical interventions in the prevention of foodborne illnesses. Taking this into consideration, the UN General Assembly has decided to designate March 22 as World Water Day. In 2007, the theme was “Coping with Water Scarcity,” highlighting the significance of cooperation and importance of an integrated approach to water resource management of water at both international and local levels, as well as taking into account the need to provide easy and inexpensive solutions that can ensure sources of safe drinking water to all populations. There were also some worldwide programs taking into account that most food-related illnesses can be avoided by some simple, inexpensive measures and common-sense hygiene. The “Five Keys to Safer Food” campaign supported by WHO is one of the best examples, trying to set simple rules to improve food safety, such as keep clean; separate raw and cooked; cook thoroughly; keep food at safe temperatures; and use safe water and raw materials. As with so many diseases, food poisoning is more likely to affect people with lowered resistance to disease. Therefore, people most at risk are children, pregnant women, and the elderly. Extra care should be taken when preparing food for these vulnerable groups to minimize the risks of their developing symptoms.
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Clinical management of patients with acute symptoms of foodborne disease is generally the same regardless of cause (rest and rehydration). However, in more complicated cases, hospital care may be needed and prompt action must be taken to ensure the swift solution of these cases. SEE ALSO: Drinking Water; Foodborne Diseases; Joint
FAO/WHO Expert Committee on Food Additives (JECFA); Lead Poisoning; Mercury.
Bibliography. Food Standards Agency, “Food Standards
Agency,” http://www.food.gov.uk (cited April 2007); International Atomic Energy Agency, “Mobile Radiation Unit Helps Fight Food Contamination,” www-tc.iaea.org/tcweb/ news_archive/Chernobyl/fightfood/default.asp (cited April 2007); World Health Organization, “Foodborne Emerging Diseases,” www.who.int (cited January 2002). Ricardo Mexia, M.D. Independent Scholar
Food Safety Food safety is paramount in today’s society as it is vital that individuals trust the food they are consuming, especially as it frequently has been produced quite far from them. A complete approach is essential, so ������������������������������������ addressing food safety issues along the entire food production chain from production to consumption is crucial. These methods provide efficient, science-based tools to improve food safety, thereby benefiting both public health and economic development. Although there has been widespread improvement in food safety, the occurrence of foodborne disease remains a significant health issue in both developed and developing countries. Unsafe food has been a public health problem for centuries, addressed by governments and organizations all over the world, still, many food safety problems encountered today are not new. Estimates show that each year 1.8 million people die as a result of diarrheal diseases and most of these cases can be attributed to contaminated food or water. Many of these foodborne diseases can be
prevented through proper food preparation, using simple and effective techniques. There are more than 200 known diseases transmitted through food, so close monitoring and deployment of food safety procedures is very important, enabling huge reductions in the burden of disease. Food safety needs to focus on several aspects, including chemical safety, microbiological safety, and radiological safety. Chemical safety deals with the contamination of food by chemical hazards Contamination may occur through environmental pollution of the air, water and soil, such as the case with toxic metals and dioxins, or through the intentional use of various chemicals, such as pesticides, animal drugs, and other agrochemicals. When exposure to a chemical in food approach or exceed the acceptable level of intake, maximum levels for chemicals in food may be set, rendering some processing techniques inadequate for the food industry. This is a leading cause of trade problems internationally as it is a economically very competitive, and is broadening the gap between developing and developed countries. On the other hand, foodborne illness caused by microorganisms is a large and growing public health problem. Most countries with systems for reporting cases of foodborne illness have documented significant increases over the past few decades in the incidence of diseases caused by microorganisms in food, including pathogens such as Salmonella, Campylobacter jejuni and enterohaemorrhagic Escherichia coli, and parasites such as cryptosporidium, cryptospora, trematodes. With globalization and the thorough use of antibiotics, microorganism are travelling faster and creating much more resistances, creating big problems in the control of these diseases. Recent concerns have arisen concerning radioactivity, which has always been around and exists naturally in the atmosphere, soil, seas, and rivers. It’s also created by human activity during energy production and military operations. Inevitably, some of this radiation contaminates food. Being invisible, tasteless, and not mentioned on food labels, it is frequently overlooked, but levels in food are strictly monitored and controlled. The World Health Organization (WHO) has long been aware of the need to educate food handlers about their responsibilities for food safety. In 2001, after extensive consultation with food safety experts
and risk communicators, WHO introduced the Five Keys to Safer Food concept, trying to reach a broader audience. The Five Keys to Safer Food poster incorporates all the messages of the Ten Golden Rules for Safe Food Preparation under simpler headings that are more easily remembered and also provides more details on the reasoning behind the suggested measures. The core messages of the Five Keys to Safer Food are: keep clean; separate raw and cooked; cook thoroughly; keep food at safe temperatures; and use safe water and raw materials. Addressing the food industry, i������������������ n 1963 the United Nations, through the Food and Agriculture Organization of the UN (FAO) and WHO, has created the Codex Alimentarius Commission to develop food standards, guidelines and related texts such as codes of practice under the Joint FAO/WHO Food Standards Program. The main purposes of this Program are protecting health of the consumers and ensuring fair trade practices in the food trade, and promoting coordination of all food standards work undertaken by international governmental and nongovernmental organizations. The Codex Alimentarius, also known as the food code, has become the global reference point for consumers, food producers and processors, national food control agencies and the international food trade. The code has had an enormous impact on the thinking of food producers and processors as well as on the awareness of the end users—the consumers. Its influence extends to every continent, and its contribution to the protection of public health and fair practices in the food trade is immeasurable. Simply stated, the Codex Alimentarius is a collection of standards, codes of practice, guidelines, and other recommendations. Some of these texts are very general, and some are very specific. Some deal with detailed requirements related to a food or group of foods; others deal with the operation and management of production processes or the operation of government regulatory systems for food safety and consumer protection. One of the techniques most widely spread to ensure food safety is HACCP (Hazard Analysis and Critical Control Point). It was initially developed for the U.S. Space Program and provided a new approach to the food safety requirements the astronauts needed. Instead ���������������������������������� of focusing on final product sampling and some items concerning manufacturing conditions, this technique focuses on preventing hazards that can cause foodborne illnesses.
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Food safety inspector marks boxes of imported meats. Two hundred known diseases are transmitted through food.
There are seven basic principles involved: (1) analyze hazards; (2) identify critical control points; (3) establish preventive measures with critical limits for each control point; (4) establish procedures to monitor the critical control points; (5) establish corrective actions to be taken when monitoring shows that a critical limit has not been met; (6) establish procedures to verify that the system is working properly; (7) establish effective recordkeeping to document the HACCP system. In the context of global markets thriving and the growing need for international regulations concerning food safety, HACCP has been adopted by the Codex Alimentarius Commission as the international standard for food safety. Nowadays, there is a new concern regarding food safety. Modern biotechnology has created a new field of development in the agriculture and food industries by introducing the use of genetically modified organisms (GMOs) in the food production chain. By artificially modifying the genetic characteristics of organisms such as plants, animals, and micro-organisms (bacteria, viruses, etc.), scientists have been able to give them a new property (a plant’s resistance to a disease or insect, improvement of a food’s quality or nutritional value, increased crop productivity, a plant’s tolerance of a herbicide, etc.). In the late 1990s, there was some dispute over the safety of GMO, originated food, mainly after research by a scientist in Scotland suggested that procedures routinely used in genetic engineering could make plants harmful. The massive controversy that followed, in the aftermath of the bovine spongiform encephalopathy
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(BSE, commonly known as mad cow disease) scandal, was responsible for a “moratorium” on GMOs and enforcement of very strict regulations. SEE ALSO: Center for Food Safety and Applied Nutrition
(CFSAN); European Food Safety Authority (EFSA); Food and Agriculture Organization of the United Nations (FAO); Food Contamination/Poisoning; Foodborne Diseases. Bibliography. WHO Food Safety site, http://www.who.
int/foodsafety/en/ (cited SJune 2007); John Pickrell “Instant Expert: GM Organisms” NewScientist.com September 2006 Codex Alimentarius, http://www.codexalimentarius. net/ (cited June 2007). Ricardo Mexia, M.D. Independent Scholar
Foodborne Diseases A significant health burden in the United States, foodborne diseases cause an estimated 76 million illnesses, 325,000 hospitalizations, and 5,000 deaths annually. Known pathogens, however, only account for a small portion of these illnesses, hospitalizations, and deaths; unknown agents account for the majority of foodborne diseases. Annually, $6 billion is spent on medical care and lost productivity due to foodborne diseases. Underreporting of foodborne illnesses continues to hinder the public health community’s ability to accurately report the incidence, prevalence, and etiology of foodborne diseases. Prevention of foodborne diseases targets the safety of the food supply, manufacturing and processing of foods, and the transport of foods from the farm to the grocery store. Foodborne diseases consist of viruses, bacteria, and protozoa. The most common causes of annual foodborne diseases are the following: Norwalk-like virus (23 million cases), Campylobacter (2.5 million), Giardia lamblia (2 million), Salmonella (1.4 million), Shigella (450,000), and Cryptosporidium (300,000). Surprisingly, E. coli, a common known cause of outbreaks in the United States, accounts for only 110,000 cases. Transmission of foodborne illnesses occurs through the fecal-oral route and ingestion and improper handling of contaminated foods.
Clinically, foodborne diseases can cause a variety of symptoms, including abdominal pain, diarrhea, nausea, and vomiting. Some diseases do not present with gastrointestinal symptoms, but can cause paralysis, headaches, or amnesia. The timing of symptom presentation after ingestion of a contaminated food can help to determine the offending pathogen. Some pathogens like Staphylococcus aureus have preformed toxins, and symptoms can occur within six to 12 hours of ingestion, while other pathogens like E. coli produce toxins within 24 hours once they are ingested. When a foodborne illness is suspected, stool specimens may be helpful in isolating the offending pathogen; however, many patients may be diagnosed clinically and do not require confirmatory laboratory testing. Treatment of foodborne illnesses can consist of intravenous hydration if a patient is volume-depleted and/or antibiotic therapy. Increasingly, antibiotic resistance is becoming a problem in the treatment of these infections; thus, physicians must carefully weigh the risks and benefits of starting antibiotics in patients. Currently, surveillance systems track the epidemiology of foodborne illnesses and outbreaks. The Centers for Disease Control and Prevention’s FoodNet is an active surveillance program that covers over 44 million Americans. Yet, the underestimation of foodborne diseases occurs due to underreporting by health care professionals to the proper authorities and the low use of diagnostic studies. Additionally, not every patient with a foodborne illness will visit their primary care physician. Prevention is an important tool to control foodborne illnesses and outbreaks. Proper hand washing and food handling can decrease the transmission of pathogens, particularly among immunocompromised persons, a susceptible population. Hepatitis A, an illness transmitted mostly through raw shellfish, can be prevented with a vaccine. Food safety must be ensured by enforcing regulations from the Food and Drug Administration and the Department of Agriculture. See Also: Bacterial Infections; Botulism; Center for Disease Control and Prevention (CDC); Digestive Diseases (General); Drinking Water; E. Coli Infections; Food and Drug Administration (FDA); Food Contamination/Poisoning.
Foot Health
Bibliography. Centers for Disease Control and Preven-
tion. “Preliminary FoodNet data on the Incidence Of Infection With Pathogens Transmitted Commonly Through Food—10 States, United States, 2005,” MMWR Morbidity and Mortality Weekly Report (2006); Richard Guerrant, et al., “Practice Guidelines for the Management of Infectious Diarrhea,” Clinical Infectious Diseases (v.32, 2001); Morten Helms, Jacob Simonsen, Kare Molbak “Foodborne Bacterial Infection and Hospitalization: A Registry-based Study.” Clinical Infectious Diseases (v.42, 2006); Paul Mead, et al., “Food-related Illness and Death in the United States,” Emerging Infectious Diseases (v5, 1999); Robert Tauxe. “Emerging Foodborne Diseases: an Evolving Public Health Challenge,” Emerging Infectious Diseases (v.3, 1997); UpToDate. “Differential Diagnosis of Microbial Foodborne Disease,” www.uptodateonline.com (cited September 2006). Lindsay Kim, MPH Emory University School of Medicine
Foot Health Feet are the foundation of our bodies, and a disorder in the foot may alter the biomechanics of the balance between the feet and the rest of the body. Due to the complex structure of the feet, an otherwise small discomfort may become magnified once the effects of gravity take place on the feet due to the load they carry. Problems with the skin of the foot may lead to an altered gait, causing hip or back problems. Footwear can lead to problems as well, pushing on nails and altering the normal stresses that are applied to the bones of the feet. A person with altered sensation of the feet due to a metabolic condition such as diabetes mellitus may be unaware that they even have a foot problem, causing severe consequences. Through education and appreciation for the feet, one can prevent serious problems. Foot care may be provided by allopathic and osteopathic physicians (MDs and DOs), and also by doctors of podiatric medicine (podiatrists) whose practice is limited to the foot and ankle. Each foot has 26 bones surrounded by a complex network of muscles, ligaments, tendons, blood vessels, nerves, subcutaneous tissue, and skin. The foot is specifically designed to ensure ultimate strength, flexibility, and functioning. Feet must withstand pres-
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sure from body weight, aid in locomotion, and allow for complex movements. This complicated structure, coupled with weight bearing, leaves many chances for malfunctioning. An estimated 75 percent of Americans have experienced a foot ailment, making it a common health concern. Although this includes many minor concerns, at times, foot disorders may be very serious, or a sign of systemic disease. Common Foot Ailments Education about common foot ailments is necessary for proper foot health. Many conditions may begin small, but can develop into more serious disorders as well as a source of constant pain. Some minor disorders that can compromise the health of the foot are blisters, corns/ calluses, warts, fungal infections (athlete’s foot), ingrown toenails, bunions, hammer toes, and heel spurs. Blisters arise in an area of skin exposed to extensive friction. A blister should not be popped but permitted to spontaneously rupture. It should be washed and covered by an adhesive bandage until the skin repairs itself, and the inciting rubbing force stopped. Corns/ calluses are layers of dead skin that have encrusted onto each other. They form in places of repetitive microtrauma to provide protection to the foot. Plantar warts are caused by viruses in the human papillomavirus (HPV) family that have entered the skin, usually through a cut. The virus is commonly contracted from walking barefoot, especially in damp public areas, such as pools and showers. This is a noncancerous growth but should be treated to prevent pain and spread of the virus around the foot. Tinea pedis (athlete’s foot) is a fungal skin infection, which results in dry skin, itching, inflammation, and at times, blisters. Onychomycosis is a fungal infection of the toenails, causing yellowing, thickened, and misshapen toenails. Fortunately, many of these minor ailments can be treated with over-the-counter remedies. However, if the problem gets worse, has changing symptoms, or is not responding to treatments, a physician should be consulted. Ingrown toenails are nails that have grown into the skin, causing pain or infection. This typically results from improper nail cutting, trauma, or infection. Most ingrown toenails can be prevented if the toenails are clipped straight across, so that they are longer than the skin edge, which prevents the corners from digging into the skin. If the nail becomes
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infected, a relatively minor condition can become very serious and painful, and will need the care of a physician or podiatrist. A bunion is a misalignment of the bones of the big toe, causing it to point toward the other toes, which alters the joint motion, and later, can cause inflammation and pain. A hammertoe is a bent, contracted toe, commonly seen on the second toe. It may result from ill-fitting shoes that may cramp the toes together into a fixed position, or from an imbalance of the muscles. Bunions and hammertoes can be treated with conservative treatment, such as changing shoes, orthotics, and antiinflammatory medications. However, in certain cases, a doctor must surgically realign the bones and debride the swollen tissue to reduce persistent pain. Heel spurs are bony growths that develop on the underside of the calcaneus (heel) bone, leading to pain in the heel region, both standing and with ambulation. Heel pain and spurs can also result in plantar fascitis, an inflammation of the fascia running along the bottom of the foot. To reduce the pain, one must treat the associated inflammation and avoid added pressure on the spur. Treat with local ice applications, antiinflammatory medications, and orthotic devices or shoe inserts to take pressure off the heel region. Rarely, but in extreme cases, is surgery performed to treat chronically inflamed spurs. Foot Heath and Diabetes The feet can also be the first place to detect certain systemic disease, such as diabetes, gout, arthritis, anemia, kidney problems, and circulatory disorders. It is important to be aware of these signs and symptoms, because they can be indicators of systemic disease. There are approximately 21 million people in the United States who have diabetes, a disease where the body does not produce or effectively use insulin, a hormone needed to convert sugar into energy. Diabetes causes blood sugar levels to be higher than normal and can have devastating effects on the blood vessels and nerves. When the blood vessels in feet become damaged, there is decreased blood and micronutrient supply to surrounding tissues leading to nerve damage. This results in a burning pain or loss of feelings in the surrounding areas, and is known as diabetic neuropathy. The combination of damaged vessels and nerves often causes diabetics to have trouble with their
feet. A loss of sensation in the feet makes it difficult to detect problems such as cuts, blisters, or ulcers. In addition, once a problem begins, the decreased blood flow from the damaged vessels will hamper healing due to lack of perfusion by oxygen and micronutrients that aid in tissue healing. There are several key steps to maintaining adequate foot health in the diabetic patient. In addition to controlling blood sugar and adhering to other medical advice, a diabetic must also take precautions to protect and care for their feet. This includes a daily wash and inspection of their feet, trimming toenails, wearing proper footwear, and routine physician visits. If these precautions are not taken, a sore on the foot of a diabetic patient may go undetected and lead to a serious infection, which can ultimately lead to systemic infection or amputation of the gangrenous foot or limb. Although foot problems are a common complication of diabetes, with adequate blood sugar control and foot care, they are preventable. Women’s Foot Health Overuse and improper foot care may disrupt the delicate balance between design and performance. Highheeled shoes are a perfect example of when a compromise in balance can cause a disorder. High-heeled shoes position the foot in a manner in which pressure is transferred to the ball of the foot, the Achilles tendon is shortened, and the toes are compressed together, all of which place unnatural stresses on the feet. Footwear is one of leading causes of foot problems in women. These positional changes may result in blisters, corns, hammertoes, bunions, as well as other medical conditions, such as osteoarthritis of the knee and low back pain. There are over-the-counter treatments for some of these foot ailments, but most of them are permanent and may require surgery to alleviate pain and restore function. The best practice for avoiding these problems is to not wear high-heeled shoes. However, many women prefer the fashion of wearing high heels. The American Podiatric Medical Association recommends that women limit the time they wear heels and vary the heel height. It is also important that women find heels that properly fit the length and width of their feet. Finding the proper balance between fashion and comfort can have long-term effects on women’s foot health.
Foot Injuries and Disorders
There are a wide range of disorders that may alter the health of the foot. Although many are minor and can be treated with over-the-counter therapies, there are serious and systemic conditions that can also cause foot ailments. The best way to ensure proper foot health is to be aware of foot disorders and maintain a balance between the structure and function of the foot. SEE ALSO: Endocrine Diseases (General); Fungal Infec-
tions Hip Injuries and Disorders; Leg Injuries and Disorders; Podiatrist; Ulcers; Virology. Bibliography. American Diabetes Association, “Diabetes
Statistics,” www.diabetes.org (cited October 2006); American Podiatric Medical Association, www.apma.org (cited October 2006); Mayo Clinic, “Foot Problems in Women: High Heels and Your Health,” www.mayoclinic.com/health/ foot-problems/WO00114 (cited October 2006). Gautam J. Desai, D.O. Ericka L. Scheller, MS II Kansas City University of Medicine and Biosciences
Foot Injuries and Disorders As the weight-bearing portion of the body, injuries and disorders of the feet are common and can be quite disruptive to an individual’s lifestyle. With 26 bones, 23 joints, and 20 muscles in each foot, compounded with athletic exercise plans and improperly fitting shoes, there is plenty of room for injuries and disorders in the human foot. Below are the most common foot injuries and disorders, their symptoms, and treatment options. Achilles Tendonitis The Achilles tendon connects the calf muscle to the back of the leg. With overuse of the tendon, it can often become inflamed and stiff. Common in young athletes, Achilles tendonitis usually occurs after a runner’s calf muscle becomes tighter and prevents normal functioning of the Achilles tendon. The Achilles tendon will often become strained and inflamed. Symptoms for acute inflammation of the Achilles tendon are pain of the tendon during exercise. Achilles
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pain will gradually increase with prolonged exercise but will be resolved with rest. As soon as pain is felt, excessive use of the tendon must stop. If usage continues despite pain, a partial rupture of the tendon may occur. Treatment of Achilles tendonitis includes antiinflammatory drugs two to three times a day. In addition, a heel pad should be used to take the strain off the tendon. Last, if pain does not subside, a sports rehabilitation professional should be seen. Ankle Sprains Ankle sprains are one of the most common injuries of the lower extremities. They result from a tearing or stretching of ligaments that surround the ankle. Usually, this occurs when the ankle is forced into a position that is not normally encountered. The most frequent type of sprain occurs when the foot inverts and rolls, when weight is applied to the ankle on an uneven surface. Situations like this usually result in a sprain to the lateral portion of the ankle. Occasionally, patients report hearing a “snapping” sound which is then followed by swelling of the ankle. There are three categories of sprains: Grade I—stretch and/or minor tear of the ligament without laxity (loosening), Grade II —tear of ligament plus some laxity, and Grade III— complete tear of the affected ligament (very loose). The most important way to treat a sprain is to rest the ankle, treat it with ice, and compress and elevate the ankle. To prevent ankle sprains, one should avoid uneven terrain and wear shoes that are firmer which will provide more support. Athlete’s Foot Athlete’s foot is a skin infection in the foot caused by a fungus called Trichophyton. When the feet, or other areas of the body, stay moist, warm, and irritated, this fungus can thrive and infect the upper layer of the skin. The fungus usually infects between the toes or the arch of the foot. The foot is vulnerable to this fungus because shoes create a warm, dark, humid place for the fungus to grow. Symptoms of athlete’s foot include dry skin, itching, burning, pain, swelling, and blisters. Athlete’s foot usually arises in places where bare feet come in contact with moist surfaces, such as swimming pool locker rooms and showers. Preventative measures include avoid walking barefoot; use shower shoes; and reduce perspiration by using talcum powder, wear light and airy shoes, and wear
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socks that keep your feet dry, and change them frequently if you perspire heavily. Antifungal drugs are often prescribed to treat athlete’s foot. A physician should be consulted if improvement is not seen after two weeks of improved self-care and hygiene. Hallux Valgus: Bunions A bunion is a bony growth on the side of the base of your big toe. Pressure from your shoe and motion at that joint can cause pain. Bunions gradually become worse until running and even walking are extremely painful. Arthritis of the great toe joint, diminished or altered range of motion, and discomfort with pressure applied to the bump or with motion of the joint may all accompany bunion development. Symptoms that occur at the site of the bunion include pain or soreness, redness and inflammation, a burning sensation, and some numbness. If the patient thinks the bunion is caused by overpronation, he or she should try an arch support or custom orthotic device, which will reduce overpronation and minimize the growth of the bunion. It is advised to also wear a pad over the bunion to reduce friction. Severely disabling bun-
ions eventually require surgery. Because bunions are progressive, they will usually get worse over time. However, some bunions progress more rapidly than others. Once your foot and ankle surgeon has evaluated your particular case, a treatment plan can be developed that is suited to your needs. Plantar Fasciitis Plantar fascia is a fibrous sheath which helps in maintaining the arch on the bottom of the foot. This fascia is shaped like a bowstring, attached to the heel bone, and spreads out to the toes. Plantar fasciitis is inflammation of the insertion of the plantar fascia on the medial process of the calcaneal tuberosity. Symptoms include pain on the weight-bearing portion, pain on the first step in the morning that comes back later in the day. Tell-tale signs of plantar fasciitis include tenderness, tightness of plantar fascia, warmth of the affected area, and redness of the adjacent skin. Treatment includes stretching and strength-building exercises, weight control, oral antiinflammatory medications, steroid injections into the heel, physical therapy, plantar fascia night splints, and plaster or synthetic casts. SEE ALSO: Foot Health. Bibliography. M.J. Breitenseher, “Injury of the Ankle
Joint Ligaments,” Der Radiologe (v.47, 2007); C. R. Daniel III and N. J. Jellinek, “The Pedal Fungus Reservoir,” Archives of Dermatology (v.142 , 2006); R.A. Mann and M.J. Coughlin, “Hallux Valgus—Etiology, Anatomy, Treatment and Surgical Considerations,” Clinical Orthopedics and Related Research (v.11/1, 1981); Frank Mayer, et al., “The Effects of Short Term Treatment Strategies over 4 Weeks in Achilles Tendinopathy,” British Journal of Sports Medicine (January 2007); “Non-Surgical Way to Heal Severe Heel Pain. A New Twist on an Old Exercise Might Bring Relief from Chronic Plantar Fasciitis,” Health News (November 2006). Mala Gurbani, B.A. University of Southern California
Forensic Medicine Injuries and disorders of the feet are common and can be quite disruptive to an individual’s lifestyle.
Forensic medicine refers to the application of medical facts to legal problems. It includes the medical exami-
nation of both the living and the dead in civil or criminal cases, along with the ethical and legal aspects of the behavior and practice of healthcare personnel. The terms forensic medicine, forensic pathology, and legal medicine are often used interchangeably to describe all aspects of forensic work, which nowadays involves the application of a broader range of sciences than those provided by medical knowledge alone. The antecedents of forensic medicine go back several millennia. The Hippocratic Oath, the basis of medical ethics, dates from the 4th century b.c.e. In ancient Greece and Rome, physicians served as expert witnesses in medical matters, albeit in an ill-defined manner. In 13th-century China, Song Ci first documented how medicine and entomology could be used to solve criminal cases, and described how to distinguish drowning from strangulation. Forensic medicine further developed in 16th-century Europe as the legal system and the state of medical knowledge matured. During this time, army and university physicians started to collect information on the manner and cause of death. Separate tracts appeared in late-18th-century Italy, France, Germany, and England on what was variously described as police, legal, or forensic medicine. Criminal investigations increasingly adopted forensic science during the 19th century and the first-known chemical confirmation of arsenic poisoning as a cause of death in a murder trial occurred in England in 1836. A number of European universities appointed chairs of Medical Jurisprudence, confirming the emergence of the field. The subject became obligatory for British medical students in 1833, but did not develop into a robust academic discipline. Forensic pathology is the academic foundation for forensic medicine. It is predominantly made up of death investigation through autopsy and associated procedures, and develops justified explanations. Patient medical histories are obtained, witness statements reviewed, and laboratory tests conducted to recreate the events surrounding a sudden, unexpected death under suspicious circumstances. Crime scenes are investigated directly or indirectly, through testimonies and photographs that may be reproduced for the benefit of a court. An autopsy is performed if the cause of death is not determinable without dissection. Although religious groups may sometimes raise obstacles to conducting autopsies, such objections can often be
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mitigated through new technologies like laparoscopic examination and computed tomography (CT) scans. Forensic medicine increasingly calls upon a broader range of sciences to answer legal questions related to crimes or civil actions. For example, a forensic anthropologist may be called to recover and identify skeletal human remains; a forensic toxicologist may be required to identify poisons or drugs and their effects on the human body; a forensic odontologist may be needed to identify a deceased person through dental examination; and a forensic entomologist may help establish the time or location of death through examining insects in, on, or around human remains, and to assess whether a body was moved after death. A forensic engineer may assess injury patterns to evaluate how an injury occurred or how and why a device or structure failed. Forensic psychologists and psychiatrists may be needed to help resolve equivocal suicides or to demonstrate mental illness and thereby incompetency to stand trial, a technique sometimes used in an insanity defense. The need for clinical forensic medicine to devote more attention to the care of living victims of crime or liability-related accidents has driven the development of forensic nursing. Although long established in England, Canada, and Australia, forensic nursing is relatively new in the United States and is just emerging in countries such as India, China, Turkey, Pakistan, Japan, and South Africa. The growing presence and credibility of forensic nursing has expanded the frontiers of forensic medicine. Biological fluids and stains may be identified by toxicology testing of specimens. For example, blood may be obtained to measure alcohol levels and urine samples may be tested for opiates, diazepines, or cocaine. Small portions of internal organs may be removed for microscopic examination. Semen is the most commonly analyzed body fluid in criminal cases. In sexual assault cases, vaginal swabs may be obtained from the posterior vaginal fornix to show that ejaculation occurred by evaluating for known semen markers: acid phosphatase (AP), prostate specific antigen (PSA, also known as p30), or MHS5 antigen. The AP test is the most common screener for seminal fluid, but AP can also be found in other biological samples such as saliva or fecal matter. The presence of semen must be confirmed by identifying spermatazoa microscopically or by detecting PSA. If more than 48 hours have elapsed since the incident,
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one or two endocervical swabs are also taken because sperm remains longer in this area. The sensitivity of some of these confirmatory tests has recently been considerably improved. Advances in genetic analysis have been quickly integrated into forensic medicine. The DNA found in forensic samples, such as blood stains or hair samples, can be used to identify a suspect, an unknown person, or human body parts. DNA fingerprinting can be used to compare a person’s genetic makeup with material evidence gathered at a crime scene. The pattern of DNA fragments seen after hybridization with specific probes gives the DNA fingerprint which, like an ordinary fingerprint, is specific to an individual. Y-chromosome STR typing is an important new forensic method for processing sexual assault samples. There are no clear repeatable patterns of clinical forensic medicine practice when viewed on an international basis. In Britain, forensic pathologists rarely deal with living individuals, but general practitioners who work as police surgeons part time are often called upon to assess cases of substance abuse or sexual assault, injured prisoners, and those with preexisting morbidity to gauge their fitness for detention, release, transfer, or police interview. In the United States, forensic pathologists working as private practitioners are frequently involved in medical malpractice cases and vehicular injury litigations. Those working in the public sector are often called upon to date or evaluate wounds in assault cases, evaluate child abuse, and provide toxicological testimony. Also, there are no international standards of forensic medicine training, although international standards exist for fingerprint identification and bloodstain analysis, and recommendations exist for the harmonization of autopsy rules. Despite the importance of independence and impartiality in forensic work, the medical care of detainees in police custody and the investigation of police complaints are variable. In some countries, there are disturbing omissions concerning causes of death in custody statistics. There has also been adverse publicity in high-profile cases involving miscarriages of justice. Unsound practices may occur because forensic science may become part of the culture of government prosecution and laboratories run by law enforcement personnel may sometimes have relatively lenient or inadequately managed quality assurance standards.
The practice of forensic medicine requires a stable legal system and adherence to ethical and human rights standards. In addition, by helping to identify and prosecute the perpetrators of human rights abuses, forensic medicine contributes to the protection of human rights in at least five ways. First, it may document injuries attributable to torture or illtreatment. Second, it may establish the manner and cause of death and a victim’s identity in cases where fatal abuse is alleged. Third, it facilitates investigation of mass graves and other war crimes. Fourth, it may identify unknown, deceased, or missing persons through DNA analysis or other means. Fifth, it sets standards for torture investigation and autopsies. Forensic specialists have been heavily involved in missions to countries beset by recent genocides such as the former Yugoslavia, Rwanda, Sierra Leone, and East Timor. They have also been increasingly engaged by human rights and nongovernmental organizations. The word forensics has become common in the media, which has publicized the work of forensic practitioners. Perhaps the best-known crime detective is the fictional character Sherlock Holmes, believed to be based on a forensic surgeon and first introduced to the world in book form in 1887, when fingerprinting began to be applied in criminal investigations. At the start of the 21st century, a number of television crime detection dramas featured the forensic pathologist as the key person in solving murder cases, performing autopsies, examining DNA, and other bodily evidence using high-tech methods, and providing expert witness. This has stimulated general interest in forensic medicine. SEE ALSO: DNA; Laboratory Tests; Pathology; Poisoning;
Toxicology.
Bibliography. Stuart H. James and Jon J. Nordby, eds.,
Forensic Science: An Introduction to Scientific and Investigative Techniques (Taylor & Francis, 2005); Jason PayneJames, Anthony Busuttil, and William Smock, eds., Forensic Medicine: Clinical and Pathological Aspects (Greenwich Medical Media, 2003); Richard Shepherd, Simpson’s Forensic Medicine (Arnold, 2003).
Andrzej Kulczycki, Ph.D. University of Alabama, Birmingham
Fractures
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Fractures Bones are living tissue which serves to provide support and structure to the human body. Fractures as defined in the most basic meaning is the breaking of a bone. Under normal circumstances, bones are able to take a certain amount of force. However, if the force put upon the bone exceeds the limit that the bone can withstand, a fracture will result. There are several clinical subtypes that fractures can be divided into. The first is a fragility fracture, which is a result of minor trauma. An example of this would be a fracture in an individual with osteoporosis whose bones are frail. Even a simple accident could result in a fracture. The second type of fracture is a pathological fracture, which is a result of a structurally abnormal bone. An example of this is a fracture in an individual who has a type of bone disease which makes their bones abnormally susceptible to fractures. The fractures in an individual with a pathological cause can result spontaneously or secondary to trauma. The third type of fracture is a high-energy fracture which is a result of serious trauma. An example of this would be an individual who falls off the roof and breaks a bone. This third type of trauma is equal to stress fractures; however, an example of stress fractures would be in an athlete who does repetitive minor trauma. The key to stress fractures and high-energy fractures is that they occur in people who have normal bones. Finally, if the fracture occurs in such a way that the bone pierces through the skin, it is called an “open” fracture. The typical clinical presentation of a fracture would be acute pain followed by swelling. In most cases, the physician’s differential diagnosis would be whether the bone is broken or there is a soft tissue injury. A fracture is fairly easy to diagnose. Signs of a fracture are pain, swelling, abnormal movement of the limb with the fracture, and deformity. Symptoms vary according to the area in which the bone is affected. A plain radiograph taken in two views is useful in confirming a suspected fracture. Although this will often confirm a suspected diagnosis, a higher type of imaging method may be used if a fracture is still not found after a plain radiograph and the symptoms are still highly suggestive of a fracture. When treating a fracture, it is important to treat it according to the location of the fracture, as well as the type. The initial management of a fracture is to immobilize the area where the bone has been broken
If the force put upon the bone exceeds the limit that the bone can withstand, a fracture will result.
so that additional damage can be prevented. Other things that can be done are elevation of the broken bone to reduce bleeding and swelling. According to the Academy of Orthopedics, the treatment of broken bones follows one rule: “The broken pieces must be put back into position and prevented from moving out of place until they are healed.” After the healing process of the broken bone, rehabilitation is also important. Rehabilitation helps to avoid joint stiffness as well as muscle wasting around the affected bone. The best way to avoid fractures is to do regular exercise and follow a diet high in calcium, both of which encourage bone strength. See Also: Bone Health; Orthopedics; Orthopedist. Bibliography. American Academy of Orthopedics Sur-
geons, “Fractures: Types and Treatments,” orthoinfo.aaos. org/brochurBroberg, K. Bertram, Cracks and Fractures (Academic Press, 1999), Ronald McRae, Pocketbook of Orthopedics and Fractures, (Churchill Livingstone, 2006). Angela J. Garner University of Missouri-Kansas City School of Medicine
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Framingham Heart Study The Framingham Heart Study was a study of cardiovascular problems based in Framingham, Massachusetts. This town, officially the largest town in New England, was first established in 1650 and had an important place in the American War of Independence, as the birthplace of Crispus Attucks—the first African American killed in the war. The study started in 1948 when 5,209 adults from Framingham were examined, and it continues to the present day with grandchildren of some of the original participants being tested. It was coordinated by the National Heart Institute (now the National Heart, Lung, and Blood Institute), which has worked with Boston University since 1971. It has also drawn people from hospitals and universities in the entire Greater Boston area. The original cohort of 5,209 men and women were between the ages of 30 and 62, an offspring cohort was added in 1971 in research conducted by Boston University, and the study of a third-generation cohort began in April 2002, allowing for a study of hereditary problems. By the middle of 2005, the study involved a survey of 4,095 people. The idea of an intensive study of one community was partially that of Thomas Royle Dawber, who from 1949 until 1966, was the chief epidemiologist in the study, taking over after its early shaky start. Born in British Columbia, Canada, he attended Harvard Medical School and after 12 years in the U.S. Coast Guard, he started work near Boston and managed to keep the Framingham study going after it initially ran out of funds. He was methodical in his approach and ensured that medical professionals all around the world were aware of causes of coronary heart disease. Dawber and his colleagues published more than 100 papers including one study in the Annals of Internal Medicine in 1961 listing the major risk factors. These included aspects such as high blood pressure, high blood cholesterol, smoking, obesity, diabetes, and physical inactivity, most of which are now widely known. Dawber was nominated for the Nobel Prize on three occasions. The Framingham study, because of its intensity and because of the long period of the surveys, has produced much of the knowledge of heart disease as well as on the effects of diet and exercise, and on
the side effects from common medications such as aspirins. Often when diagnosing patients, medical professionals compare patients with those studied at Framingham. Some critics of the Framingham Heart Study claim that it overestimates the risk posed to people, with lower-risk groups, such as some communities in other countries, being far less prone to suffer from particular aspects of heart disease. Nevertheless, many medical professionals continue to use the data collected by the Framingham study, and another study has also been undertaken at Busselton, Western Australia, although the results from Framingham are more widely cited. SEE ALSO: Cohort Study; Heart Diseases (General); Heart
Diseases—Prevention; National Heart, Lung, and Blood Institute (NHLBI).
Bibliography. Framingham Heart Study, www.fram-
inghamheartstudy.org; Daniel Levy and Susan Brink, A Change of Heart: How the People of Framingham, Massachusetts, Helped Unravel the Mysteries of Cardiovascular Disease (Knopf, 2005). Justin Corfield Geelong Grammar School, Australia
France One of the most technically advanced nations in the world, France has a per capita income of $29,600 and ranks as the 27th richest nation. The United Nations Development Programme’s (UNDP) Human Development Report ranks France 16th of 177 nations on overall quality-of-life issues. France has an enormous national budget, and the tax burden is heavy. The process of privatizing is ongoing, and the government continues to maintain control of several mega businesses, including Air France, France Telecom, Renault, and Thales. Unemployment hovers at 10 percent and is heavily correlated with the poverty rate of 6.5 percent. France ranks 32.7 on the Gini inequality index, with the richest 10 percent of the population claiming 25.1 percent of resources and the poorest 10 percent holding on to only 2.8 percent. The population of 60,876,136 expe-
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France is one of the most technically advanced nations in the world and ranks 27th in terms of income, and has a relatively low incidence of death from heart disease when compared with other industrialized nations.
riences a life expectancy of 79.73 years, with females outliving males an average of eight years. Virtually all of the relevant population is enrolled in primary and secondary school. Safe drinking water and improved sanitation are universally available. France spends an average of 16 percent of the total budget on healthcare. Just over ten percent of the Gross Domestic Product (GDP) is used to finance healthcare programs, and $2,902 (international dollars) is allotted per capita. The French government accounts for 76.3 percent of all health spending, and 96.7 percent of that amount is earmarked for social security. The private sector provides 23.7 percent of total health spending with out-of-pocket expenses comprising 43.20 percent of private expenditures. There are 3.37 physicians, 7.24 nurses, 0.26 midwives, 0.68 dentists, and 1.06 pharmacists per 1,000 population in France. Social security covers all employed individuals, but some groups such as railroad and mining employees and farmers are covered under special systems.
Nonworking heads of household, the unemployed who serve as adult care givers, and French citizens who live abroad may opt to be covered under the pension. In addition to elderly benefits, the system provides assistance, including a family allowance, to single parents. Social security is financed through employee and employer contributions and supplemented by the government. A separate program for sickness and maternity benefits is responsible for benefits to the disabled and survivors. Significantly ill persons may receive half of their salaries for up to a period of six months. If a condition is chronic, coverage is extended to three years. Pregnant women on maternity leave earn full salary for six weeks before and 18 weeks after giving birth. Adjustments are made for subsequent and multiple births. Adoptive parents receive the same benefits in the postpartum period as do other mothers. Teen pregnancy is a major problem in France, and between 3,000 and 4,000 girls under the age of
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16 become pregnant each year. From 700 to 1,000 of those pregnancies are terminated in any given year. To combat this problem, the government has launched a public awareness program and now requires compulsory education in all schools, colleges, and handicapped facilities. Overall birth rates began to climb in 2001, partly because of an increase in the number of multiple births. Three-fourths of French females report that they use some method of birth control, and French women currently give birth at a rate of 1.84 children each. Only one percent of births occur outside the presence of trained medical personnel, and 99 percent of women receive antenatal care. The maternal mortality rate of ten deaths per 100,000 live births has remained stable in recent years. France has the 12th lowest infant mortality rate in the world at 4.21 deaths per 1,000 live births. Between 1990 and 2004, the government succeeded in cutting the infant mortality rate from seven to four deaths per 1,000 live births. During that same period, under-5 mortality was reduced from nine to five deaths per 1,000 live births. Despite general good health, 7 percent of French infants are underweight at birth. Infant immunizations are high in the areas of diphtheria, pertussis, and tetanus (DPT1) at 98 percent. Vaccinations for DPT3 and polio drop slightly (97 percent each), as do those for measles and haemophilus influenzae type B (86 percent each). Tuberculosis immunizations (85 percent) fall even further. The lowest rate of immunization is among children receiving hepatitis B vaccinations (28 percent). HIV/AIDS is of concern to the French government due to an adult prevalence rate of 0.4 percent. Some 120,000 people are living with this disease, which has taken the lives of around 1,000 individuals. Other communicable diseases surface periodically in France. Leptospirosis and listeria were reported in 2000, and meningococcal disease generated concern in 2000 and 2001. In 2003 and 2004, France experienced outbreaks of influenza. In 2003, legionellosis and Severe acute respiratory syndrome (SARS) provided scares. Rabies appeared in 2004 and chikungunya in 2006. Cancer is the leading cause of death in France among the general population, but circulatory diseases rank first among the elderly. Smoking is
banned in restaurants, schools, and most public buildings. France has a relatively low incidence of death from heart disease when compared with other industrialized nations. France has taken a leadership role in dealing with communicable diseases among the world’s children. In fall 2006, the government announced that it had joined with Brazil, Britain, Norway, and Chile under the auspices of the Geneva-based Unitaid to target taxes imposed on air fares for funding treatment for children diagnosed with HIV/AIDS, tuberculosis, and malaria. The group is working with a foundation headed by former president Bill Clinton to obtain discounted drugs for affected children. Ultimately, the program hopes treat 200,000 people affected with AIDS, 150,000 children diagnosed with tuberculosis, and 28,000,000 infected with malaria. See Also: European Public Health Association (EUPHA);
Healthcare, Europe.
Bibliography. Central Intelligence Agency, “France,”
World Factbook www.cia.gov/cia/publications/factbook/geos/fr.html; Commission on the Status of Women, France,” www.un.org/womenwatch (cited August 2007); Spencer Di Scala, Twentieth Century Europe: Politics, Society, Culture (McGraw-Hill, 2004); Celia W. Dugger, “Five Nations to Tax Airfare to Raise Funds for AIDS Drugs,” New York Times, (September 19, 2006); Sandra Halperin, War and Social Change in Modern Europe: The Great Transformation Revisited (Cambridge University Press, 2004); Martin A. Levin and Martin Shapiro, eds., Transatlantic Policymaking in an Age of Austerity: Diversity and Drift (Georgetown University Press, 2004); Jeremy Rifkin, The European Dream: How Europe’s Vision of the Future Is Quietly Eclipsing the American Dream (Jeremy P. Tarcher/ Penguin, 2004). Elizabeth R. Purdy, Ph.D. Independent Scholar
Fraternal Twins Twins are two children who share the same pregnancy and are born during the same birthing process. Fraternal twins, or nonidentical twins, are twins who are the
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Therefore, these women have a higher chance of having fraternal twins. In recent years, there has been an increase in the rate of fraternal twin births. Some attribute this to changing practices in society where some women are having children at later ages. Such older woman are more likely to need fertility treatment and thus are more inclined to give birth to multiple babies. SEE ALSO: Pregnancy; Premature Babies. Bibliography. March of Dimes, “Quick References
and Fact Sheets: Twins, Triplets, and Beyond,” www. marchofdimes.com (cited October 2006). E. John Ly, M.D. Brown University Medical School
The rate of fraternal twins in the general population is estimated to be around two to 14 per 1,000 births.
products of two separate eggs fertilized by two separate sperm in contrast to identical twins who are formed from one sperm and one egg. Fraternal twins result in two independent zygotes that both implant in the uterus. Thus, fraternal twins are also known as dizygotic twins. In regards to genetics, fraternal twins are exactly like any other pair of siblings. They are extremely unlikely to have identical genes, can be the same or opposite gender, and can appear similar or different. As with all twins, fraternal twins are more likely to be born prematurely due to the size restriction of the female uterus. Such premature newborns are susceptible to more complications that full-term newborns. With current medical technology and the capability to successfully care for premature babies, twins generally do as well. The rate of fraternal twins in the general population is estimated to around two to 14 per 1,000 births, but is higher among couples who undergo infertility treatments. Fraternal twins are rare because women usually release one ovum per menstrual cycle. However, those who are undergoing in vitro fertilization may be implanted with multiple embryos to increase the chances of at least one taking hold in the uterus and those taking drugs such as clomifene are intentionally stimulated to release multiple eggs from their ovaries.
Fredrickson, Donald (1924–2002) Donald Fredrickson was an American physiologist and leader in the field of biomedical research who made significant contributions to medicine over the course of four decades. He devised a system of classification of abnormalities in fat transport which was adopted by the World Health Organization (WHO). Fredrickson’s classification became an international standard for identifying increased risks of coronary artery disease linked to the consumption of fats and cholesterol. He also discovered two genetic diseases caused by disorders in lipid metabolism. Throughout his career, Fredrickson proved an innovative researcher and an able administrator of the many prestigious institutions he chaired. Donald Fredrickson was born in Cañon City, Colorado, on August 8, 1924. He attended the University of Michigan which awarded him a bachelor’s degree in 1946 and a medical degree in 1949. Fredrickson enrolled for postgraduate studies at Harvard University Medical School and Massachusetts General Hospital and, during this period, he was largely supported by his Dutch wife Henriette Priscilla Dorothea Eekhoff. In 1953, Fredrickson started working for the National Institutes of Health (NIH) in Bethesda, Maryland, and was certified by the American Board of Internal Medicine in 1957. His successful combination of laboratory
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research with clinical practice allowed him to become director of the National Heart Institute (now National Heart, Lung, and Blood Institute) in 1966. During Fredrickson’s two-year term as director, the South African surgeon Christiaan Barnard performed the first heart transplant in a person. In 1974, Fredrickson was named the second president of the Institute of Medicine, a healthcare and medical research policy group established in Washington, D.C., by the National Academy of Sciences. A year later, Fredrickson returned to the NIH, becoming its director for the next six years. This was a difficult time to serve as director of the NIH as fears over genetic manipulation were spreading rapidly through the general public and economic stagnation prompted the federal government to reduce public funds for the Institutes. Fredrickson, however, was a painstaking mediator who was able to preserve the freedom of scientific inquiry and, at the same time, to placate public fears of genetic manipulation. He was also capable of assuring a steady influx of funds to the Institutes. In the mid1970s, Fredrickson was appointed personal physician to King Hassan II of Morocco. After he completed his tenure in 1981, Fredrickson spent two years as Scholar-in-Residence at the National Academy of Science and then became president, chief executive officer, and trustee of the Howard Hughes Medical Institute (HHMI). He died at his home in Bethesda on June 7, 2002. SEE ALSO: Cholesterol. Bibliography. Donald S. Fredrickson, Recombinant
DNA Controversy: A Memoir: Science, Politics and the Public Interest, 1974–1981 (ASM Press, 2001); “Biographical Note,” Web site of the United States National Library of Medicine, www.nlm.nih.gov/(cited June 2007).
Luca Prono Independent Scholar
Fungal Infections Fungi are eukaryotic (contain a true nucleus) organisms that lack chlorophyll and rely on preformed
Of more than 100,000 fungal species, only several hundred cause infection and disease in humans.
organic matter as their energy source. Fungi may be grouped into two broad categories—yeasts and molds—based on their physical characteristics (single cells or hyphae) and mode of reproduction (budding or spore formation). Many species are dimorphic and may exist as yeast and as molds depending on the temperature or other characteristics of the physical environment. In general, fungi grow in damp, dark environments. The specific type of fungi present in a particular area depends on environmental conditions and available substrates. Of more than 100,000 fungal species, only several hundred cause infection and disease in humans. Fungi are found ubiquitously in the environment; however, despite this constant exposure, serious fungal diseases are rarely found in immunocompetent individuals. Fungal infections, called mycoses (myco Latin for fungus), may be superficial, deep, or systemic, and may cause very mild to life-threatening disease. The most common types of fungal infections are superficial skin infections caused by a variety of fungal species known as dermatophytes. While most fungal infections are not spread from person to person, superficial mycoses often are. The clinical con-
ditions, tinea pedis, tinea manis, tinea corporis, and tinea capitis, affect the feet (athlete’s foot), hands, body, and head, respectively. These infections are most often an itchy nuisance which can usually be easily controlled with topical medications. Pytiriasis versicolor is a fungal skin infection most often found around puberty and causes hyper- or hypopigmentation of the skin. Onychomycosis is a fungal infection of the finger or toe nails which can be chronic and difficult to treat. Piedra is a fungal colonization of the hair shaft in which the color and steadfastness of the fungal nodules depends on the species of fungus. A species of yeast called candida albicans is responsible for superficial infections of mucous membranes such as the vagina or mouth and are known commonly as yeast infections. Candida species can also cause skin infections in warm, moist areas, particularly in babies (diaper rash) or in adults in intertriginous areas or folds of fat in the breasts or abdomen. In people with HIV/AIDS, on chemotherapy, or with other immunocompromising conditions, superficial mycoses can progress to serious life-threatening conditions. For example, candidal infections can spread from the oral cavity to the esophagus, causing candidal esophagitis which can be very painful and prevent already-ill people from eating or drinking. Fungal infections of the eyes, though superficial, can be very serious. Mycotic keratitis (fungal infection of the cornea of the eye) can take many forms, and is associated with contact lens use, eye surgery, and immunosuppressive illnesses. Fungal infections that infect deeper skin tissues include sporothrix schenckii, a dimorphic fungi classically contracted from a piercing from a rose bush. Sporotricosis manifests as pain and redness that tracks up lymphatic vessels in the arm or leg and treated with oral antifungal medications. Mycetoma or madura foot is a fungal infection of an extremity, usually the foot, which invades and destroys skin and subcutaneous tissue. It can spread to deeper tissues such as bone and tendon, and cause very serious disability. Systemic fungal diseases are those that enter through a break in the skin, the lungs, or mucous membranes and progress to infect other parts of the body. These are much more serious infections that are usually only found in specific geographical re-
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gions where the fungi are found in the environment. For example, paracocidiomycosis is a fungal infection found only in Latin America. Spores of the fungus are inhaled and immediately invade the body, but the infection may remain dormant for many years. When it manifests, patients, usually men, present with painful ulcers in the mouth, nose, and throat. Paracoccidiomycosis is very difficult to treat and may progress or present as a lung infection resembling tuberculosis. Histoplasmosis is a systemic fungal infection found throughout the world and usually affects the lungs, but may involve any body organ. It has become much more common since the HIV epidemic and, depending on the individual, it may cause anything from flulike illness to death. The histoplasma fungus is most often found in soil enriched by bat or bird droppings and is, therefore, classically found in spelunkers. It may also be acquired occupationally by those working in mines, excavation sites, or other activities that may disrupt and aerosolize spores. Cryptococcosis is caused by an encapsulated yeast, which like histoplasmosis, is inhaled, and is also common in AIDS sufferers. One of its most severe manifestations is cryptococal meningitis which is a fungal infection of the membranes surrounding the brain, often leading to death. Blastomycosis is a fungal disease which is found in southeastern and south-central United States and Canada. This fungi is found near streams or in areas with moist soil where its spores are inhaled by people working or recreating in these areas. The spores then enter the lungs and develop into yeast which causes an asymptomatic infection in over 50 percent of people. In others, it can cause acute lung infection resembling a bacterial pneumonia, or chronic lung infections that may mimic lung cancer on X-ray. Blastomycosis, like other systemic mycoses may also affect other body systems, particularly bones, and the genitourinary tract. Antifungal medications exploit the fact that fungal cells use ergosterol in their cell walls whereas human cells use cholesterol. Medications from the azole group (ketoconazole, clotrimatzole, etc.) inhibit the synthesis of ergosterol, whereas polyene antimycotics (amphotericin) disrupt the ergosterol cell wall, killing the cells. Newer echinocandins (mycafungin) inhibit the synthesis of glucan, another cell wall component.
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Fungal infections may be simple or difficult to treat using these agents, with the success of treatment often depending as much on the host as on the medication or the fungus itself. Serious fungal infections in the developed world became more common during the height of the AIDS epidemic, but since the advent of highly active antiretroviral therapy (HAART), they have become less frequent. Fungal infections are still a cause of significant morbidity and mortality in the developing world, particularly in those with high HIV prevalence.
SEE ALSO: Molds. Bibliography. Eugene Braunwald, et al., eds., Harrison’s
Principles of Internal Medicine, 15th ed. (McGraw-Hill, 2001); Tony Hart, Microterrors: The Complete Guide to Bacterial, Viral and Fungal Infections That Threaten Our Health (Firefly Books, 2004). Barry Pakes, M.D., M.P.H. University of Toronto
G Gabon Gabon, known officially as the Gabonese Republic, is located in western Africa, with a coast on the Gulf of Guinea. The country was part of colonial French Equatorial Africa from 1910 to 1960. Per capita income in Gabon is four times that of other sub-Saharan nations, largely because of the rich offshore oil deposits that form most of its exports. Despite being home to 40 distinct ethnic groups, Gabon is mostly free from internal strife. In 2007, Omar Bongo became the longest-serving African president and celebrated his 40th year in power. The population is 1,455,000, growing at 2.04 percent annually. The birth rate is 35.96 per 1,000 and the death rate is 12.45 per 1,000. More people are migration out of Gabon than into it, with a migration rate of minus 3.15 migrants per 1,000. Median age is 18.6 years. Life expectancy is currently 52.85 years for males and 55.17 years for females. Gross national income is U.S. $5010, high for the region. However, it is not equally distributed, and many Gabonese live in poverty. About 60 percent of the population relies on agriculture. Gabon has had several small but highly publicized outbreaks of the Ebola virus in recent years. Still, the main killers of the Gabonese are more routine communicable diseases, such as malaria, which is endemic, and typhoid. Only 88 percent of the population
has access to clean drinking water and 37 percent use sanitary waste facilities. Gastrointestinal and parasitic infections are common. HIV/AIDS affects 7.9 percent of the adult population, with 60,000 Gabonese infected with the virus and 4,700 having already died. Gabon is among the 13 nations participating in the Joint United Nations Programme on HIV/AIDS (UNAIDS) Accelerating Access Initiative to buy drugs for reduced rates from suppliers, although currently only 23 percent of those infected are on antiretorviral drug therapy. Less than 1 percent of at-risk pregnant women are receiving drugs to reduce mother-to-child transmissions. Girls in Gabon marry young, sometimes as early as 10 or 12 years of age. The fertility rate is 4.71 children per woman. Contraception is avaliable to 33 percent of women. Abortion is legal in only a few situations, so many women rely on illegal abortions, often suffering major complications as a result. Ninety-four percent of pregnant women receive some prenatal care. Eight-six percent have the help of trained assistance during childbirth. The maternal mortality rate is 420 deaths per 100,000 live births. Infant and child mortality rates have held steady since 1990. Sixty of every 1,000 infants die before the age of 1; 91 of every 1,000 children die between their first and fifth birthdays. Immunization rates are low, and children
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are most vulnerable to malaria and other communicable diseases. Malnutrition is not a serious issue in Gabon, although 12 percent of children are underweight and 21 percent show signs of stunted growth. Gabon spends more on healthcare per capita than most of its neighbors, at U.S. $181. There are 27 hospitals and 660 clinics spread across the country, although access to care is uneven. There is a medical school at Université Omar Bongo. Three institutions, the Université Omar Bongo, the Albert Schweitzer Hospital, and the International Center for Medical Research, conduct research into malaria, AIDS, and other regional health concerns. See Also: Joint United Nations Programme on HIV/AIDS
(UNAIDS).
Bibliography. Central Intelligence Agency, World Fact-
book, “Gabon,” www.cia.gov/library/publications/theworld-factbook (cited June 15, 2007); IPS: Inter Press Service, “HEALTH-GABON: Abortions Mostly Illegal, But in Demand,” ipsnews.net (cited June 15, 2007); Researchafrica. rti.org: Sub-Saharan Africa-Gabon,” researchafrica.rti.org (cited June 15, 2007); UNAIDS: The Joint United Nations Programme on HIV/AIDS, “Gabon”, www.unaids.org/en (cited June 15, 2007); UNICEF, “UNICEF-At a glance: Gabon-Statistics,” www.unicef.org/infobycountry (cited June 15, 2007). Heather Michon Independent Scholar
Gage, Phineas (1823–60) Phineas Gage was a railroad foreman who endured a traumatic brain injury resulting in significant changes in his mental capacities. Over 160 years since his accident, Gage continues to play a significant role in defining the function of the brain in emotion and personality. On September 13, 1848, near Cavendish, Vermont, working with the Rutland and Burlington Railroad, a 25-year-old man, Phineas Gage, was clearing rocks to level the ground. The task involved placing an explosive charge deep into the rock by drilling a hole. The hole was then filled with gunpowder and a fuse was set. Sand was added on top of the explosive material to pre-
vent contact. A tamping rod was then used to pack the explosives deep into the rock. Unfortunately, on that fateful afternoon, Gage was distracted and he tamped down the powder without the addition of the sand. As his three-foot-long iron tamping rod, with a diameter of 1.25 inches, struck against the side of the rock, it ignited the gunpowder, shooting the rod completely through Gage’s head, landing almost 30 yards behind him. The 13.5 pound rod inserted into Gage’s skull just below his left cheekbone exiting from the top of his skull. Extraordinarily, Gage survived the accident. He sustained no motor or speech impairments and his memory remained intact. Within a matter of months, Gage regained his physical strength and was able to return to work. However, his personality dramatically changed, causing his colleagues to state that he was “no longer Gage.” A once-efficient, focused, and wellbalanced man with a strong work ethic, Gage had become restless, disrespectful, and unreliable, unable to execute plans. He eventually died in 1860, nearly 12 years after his tragic injury, of epileptic seizures. Gage’s skull and the iron tamping rod are on permanent exhibition at Harvard Medical School’s Warren Anatomical Museum in Cambridge, Massachusetts. The exact location and extent of injury to Gage’s brain continues to hold controversy, as it is uncertain if the lesion involved only the left or both frontal lobes. His ensuing personality change was the first clinical case to suggest the role of the frontal lobes in emotion and socially appropriate behavior. SEE ALSO: Brain Diseases; Phrenology. Bibliography. John Fleischman, Phineas Gage: A Grue-
some but True Story about Brain Science (Houghton Mifflin, 2004); Malcolm Macmillan, An Odd Kind of Fame: Stories of Phineas Gage (MIT Press, 2000).
Shannon Gearhart, M.D. Indiana University School of Medicine
Gallbladder and Bile Duct Diseases The production of bile is important for digestion and aids in the absorption of dietary fat. Bile is a heteroge-
neous mixture formed in the liver as an isotonic fluid and secreted into the bile duct. Bile is stored in the gallbladder, and food stimulates the release and secretion of the bile. Once released, bile flows into the duodenum and mixes with the food incoming content. Bile functions: (1) to aid absorption by making dietary cholesterol, fats, and fat-soluble vitamin soluble; (2) induce water secretion in the colon; and (3) excrete bilirubin, degradation products from worn-out red blood cells. The formation of calculi (gallstones) occurs in the gallbladder and can lead to acute and chronic inflammation of the gallbladder. The passage of the stone into the common hepatic duct obstructs the flow of secretion from the liver and pancreas and leads to serious and lethal complications. Bile Production Bile is an isotonic fluid whose electrolyte composition resembles that of blood plasma. It is produced by the liver and contains bile acids, bilirubin, cholesterol, phospholipids, and electrolytes. Soluble bile acids, the major solute components of bile (80 percent), are synthesized from water-insoluble cholesterols. The primary bile acids are cholic acid and chenodeoxycholic acid (CDCA). They are formed by conjugating glycine or taurine into cholesterol molecules. Bile Secretion Bile formed in the hepatic lobules are secreted into a network of bile ducts that eventually forms the right and the left hepatic ducts. The two hepatic ducts then converge to form the common hepatic duct. Off of the common hepatic duct is the gallbladder which is connected via the cystic duct. The cystic duct and the common hepatic duct join together to form the common bile duct, which enters the duodenum through the ampulla of Vater. Joining the ampulla are pancreatic ducts, through which exocrine pancreatic secretions are made. The sphincter of Oddi surrounds the common bile duct and the pancreatic duct. During fasting state, bile is secreted by the liver and about 50 percent of the secreted bile flows into the gallbladder via the cystic duct and is stored there. The remaining secretion flows into the common bile duct and is trapped in the duct due to the constriction of the sphincter of Oddi. The bile secretion that is stored in the gallbladder is highly concentrated because up to 90 percent of the water in the secretion are absorbed in the
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gallbladder. When an individual eats and food enters the duodenum, a series of hormonal and neuronal processes are activated that causes the contraction of the gallbladder and the relaxation of the sphincter of Oddi. Cholelithiasis Cholelithiasis is the formation or the presence of calculi in the gallbladder. Gallstone is the most frequent cause of clinical disorders relating to extrahepatic biliary tracts. In the United States, it is estimated that at least 20 million individuals have gallstones and the incidence of cholelithiasis is 1 million per year. More than 500,000 cholescystectomies are performed each year. Gallstones are divided into two major types: cholesterol stones and pigment stones. The predominant composition of cholesterol stones is cholesterol monohydrate, while pigment stones primarily are composed of calcium bilirubinate. Cholesterol gallstones formation is primarily due to the supersaturation of cholesterol in the bile. Other causes include the nucleation of cholesterol monohydrate and hypomotility of the gallbladder leading to delayed emptying. Pigment gallstone formation is primarily due to the presence of increased amounts of unconjugated and insoluble bilirubin in the bile, which then precipitates to form stones. Risk factors that predispose individuals to gallstone formation are 1.) obesity, 2.) rapid weight loss (low caloric intake), 3.) female sex hormones (i.e., pregnancy, contraceptives), 4.) age, 5.) gallbladder hypomotility, 6.) high fat diet, 7.) cystic fibrosis, and 8.) alcoholic cirrhosis. Treatment of cholelithiasis include surgical removal of gallbladder, medical dissolution of gallstones via medication, and stone fragmentation via the administration of extracorporeal shock wave. Cholecystitis Cholecystitis is the inflammation of gallbladder. Cholecystitis can be categorized as acute or chronic. Acute cholecystitis, inflammation of the gallbladder wall occurring as a response to cystic duct obstruction by a gallstone, is the most common cause of cholelithiasis. Symptoms of acute cholecystitis are recurrent worsening colicky pain in the right upper quadrant, often radiating into the right lower scapula, nausea, and vomiting. An enlarged and palpable gallbladder is present in about half of individuals with acute cholecystitis.
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During deep inspiration, pain increases and there is sudden stop of breathing (Murphy’s sign). The attack of acute cholecystitis typically resolves within a week. The triad sign of right upper quadrant pain, fever, and leukocytosis are highly suggestive of acute cholecystitis. Treatment and management include rehydration via intravenous fluids and electrolytes and parenteral antibiotics are given to prevent infection. Cholecystectomy will cure acute cholecystitis. In chronic cholecystitis, there are pathological findings of fibrotic, thick-walled, and contracted gallbladder. The mucosa may be ulcerated and scarred and stones or sludge often obstruct the lumen. It is thought that chronic cholecystitis results from the persistent bouts of acute cholecystitis and/or the mechanical irritation of the gallbladder wall from gallstones. The treatment and management of chronic cholecystitis is the same as that of acute cholecystitis. Choledocholithiasis Choledocholithiasis is the formation or the presence of the stones in the common bile duct. The passage of stones into the common bile duct occurs in about 15 percent of cholelithiasis patients. The incidence of stone in the common bile duct increases with age and it is estimated that up to 25 percent of elderly cholelithiasis patients have stones in the common duct. Stones in the common bile duct is the most common cause of extrahepatic obstructive jaundice and it can lead to serious or lethal infection (cholangitis), pancreatitis, or chronic liver disease. The obstruction of the biliary tree is a major source of bacteremia and systemic infection as gram-negative bacteria quickly colonize the area. Endoscopic and/ or surgical interventions are required to decompress the area. SEE ALSO: Bacterial Infection; Liver Diseases (General). Bibliography. Thomas E. Andreoli, et al., “Disorders of
the Gallbladder and the Biliary Tract,” Cecil Essentials of Medicine (Saunders, 2003); “Gallbladder Disease,” Medline Plus, www.nlm.nih.gov/medlineplus (cited March 2007); Marshall Kaplan, “Medical Progress: Primary Biliary Cirrhosis,” New England Journal of Medicine (v.335, 1996). James S. Yeh Boston University School of Medicine
Gallbladder Cancer The gallbladder is an organ located beneath the liver which participates in the digestion of food, specifically in the breakdown of fats, which are catalyzed by the liquid stored in the gallbladder known as bile. Cancerous cells can infest the tissue of the gallbladder, although this is a rare condition, which is slightly more common in women than in men. Hard clusters of material can form in the gallbladder (gall stones) and these can be painful and require surgery. The entire gallbladder can be removed if required without causing any particular problems to the patient. It is often during this procedure that any cancer of the organ is detected, because there are no characteristic symptoms of gallbladder cancer and the organ itself is quite difficult to access or to inspect. Some symptoms that can be caused, for example, jaundice, fever, weight loss, loss of appetite, and others, may arise from a number of different causes and, indeed, diagnosis is likely to attribute the symptoms to one of the more common conditions. People with a history of passing gallstones may have a slightly higher susceptibility to gallbladder cancer, but the underlying cause of the cancer is not fully known. Gallbladder cancer is best treated, as in the case of most cancers, if the disease is detected at an early stage and, particularly, before the cancer spreads or metastasizes. The extent to which the cancer has spread before it is detected will determine the nature of the treatment chosen. Surgery is possible if the disease remains localized in the gallbladder, which may be excised in a cholecystectomy, which might also involve removing part of the nearby liver. An alternative is to bypass the bile ducts where the passage has been blocked by cancerous cells. Some other surgical procedures may be effective depending on the spread of the disease. A catheter may be used to reroute the bile in some cases. It is also possible that surgery can be used to relieve painful or distressing symptoms caused by the buildup of cancerous masses in the body. If the cancer can be resected (excised) by surgery, then patients may have an 80 percent chance of survival; if this cannot be managed either because of the extent or the configuration of the spread, then survival chances can fall to 5 percent in some cases. Of course, advice from medical practitioners should be sought for a particular diagnosis and because of
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the possibility of the introduction of effective new techniques. It is also possible for the cancer to recur even when excised. Tests for recurrence are difficult to conduct effectively for similar reasons to those that make initial detection problematic. Surgery may be used in addition to either or both of chemotherapy and radiotherapy. External-beam radiation therapy may be used to attack the cancerous cells, but given the location of the gall bladder, this is once again often practically difficult to implement. Some drugs may act to make the relevant cells more sensitive to the radiotherapy and these are generally injected intravenously. As the cancer spreads, it may lead to general ill health and weakness which make the patient less resistant to the side effects of any such treatment and its sometimes debilitating effects. Drugs that have been used with some success include Mitomycin c and 5-FU, although these are associated with side effects, while capecitabine, a drug that is administered orally, shows promise in attacking gallbladder cancer. However, this drug is also associated with many side effects which will require careful management. Attention to general health issues such as diet and nutrition, exercise, and a positive psychological approach can in some cases assist in enabling the body to resist these effects. Specific remedies at this stage may include assistance with sleeping to overcome sleep disorders and nausea, frequent small meals to combat reduced size of the stomach, diuretics to reduce swelling, and often quite high dosages of pain-relief medications. Pain-relief drugs may require careful management because these are metabolized in the liver and the patient may suffer from an imperfectly working liver as a result of the cancer. SEE ALSO: Cancer (General); Cancer Alternative Therapy;
Cancer Chemotherapy; Cancer Radiation Therapy; Cancer—Coping with Cancer. Bibliography. E. J. Boerma, “Towards an Oncological
Resection of Gall Bladder Cancer,” European Journal of Surgical Oncology (v.20/5, 1994); Alan P. Venook and Sabrina Selim, “Cancer of the Gall Bladder,” http://www.cancersupportivecare.com/gallbladder.html (cited June 2007). John Walsh Shinawatra University
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Galton, Sir Francis (1822–1911) Francis Galton was born in Birmingham, England, in 1822. He is best known for coining the term eugenics, from the Greek for “well born,” in 1883. Galton was heavily influenced by his cousin Charles Darwin’s book On the Origin of Species (1859) and his position as a member of the British elite. He began doing quantitative research on heredity in the 1860s to demonstrate how it worked and how it might be used to manipulate the germ plasm, or what might today be called the gene pool, to improve society. Ruth Schwartz Cohen has argued that Galton redefined “heredity,” thus eventually helping the progress of genetics as a field. Galton developed the field of biometrics, the statistical study of hereditary patterns on a population level. Galton’s student Karl Pearson (1857–1936) continued his research program. Heredity was of ongoing interest to 19th-century intellectuals and laypeople, both of whom thought that children inherited traits and tendencies their parents acquired along with heritable physical characteristics. The idea that social and biological decline should be reduced through responsible marriage and moral behavior was on the minds of especially the upper class, who attributed rising crime and disease rates in urban areas to increasing numbers of degenerate people. Galton’s research did not demonstrate a radical break with previous attitudes about heredity and its relationship to civilization, but rather it attempted to redefine heredity and locate the solution to societal problems in science. He thought that stockbreeding techniques should be applied to humans. Galton’s contributions to eugenics lay primarily in his late-19th–century publications about the relationship between social class and the inheritance of ability and his development of biostatistics (also called biometry) as a discipline. While known primarily as an advocate of eugenic reform and for his statistical studies of heredity, Galton was also an active member of the Royal Geographical Society, an explorer, meteorologist, anthropometrist, and leading researcher on the statistical study of evolution. He was knighted in 1909 and died in 1911. SEE ALSO: Darwin, Charles; Genetics; Phrenology.
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Bibliography. Daniel J. Kevles, In the Name of Eugen-
ics: Genetics and the Uses of Human Heredity (Harvard University Press, 1985); Ruth Schwartz Cohen, Sir Francis Galton and the Study of Heredity in the Nineteenth Century (Garland, 1985); Francis Galton, Hereditary Genius (Macmillan, 1869); Francis Galton, Inquiries into Human Faculty and Its Development (J. M. Dent, 1883). Christine L. Manganaro University of Minnesota
Gambia Gambia is located in western Africa, completely surrounded by Senegal except for a 80 kilometers (50 miles) long coast on the Atlantic Ocean. Only 48 kilometers (30 miles) across at its widest point, Gambia follows the track of the River Gambia for 740 kilometers (460 miles). The country is overwhelmingly rural, with only 20 percent of Gambians living in urban areas. Poverty is widespread, with much of the population working as subsistence farmers; the chief export crop is the groundnut (or peanut). The population is 1,688,000, growing at 2.78 percent annually. The birth rate is 38.86 per 1,000 population and the death rate is 11.99 per 1,000 population. Median age is just 17.8 years, with 49 percent of Gambians under the age of 18. Life expectancy is 52.68 years for males and 56.46 years for females. Only a quarter of the population lives in urban areas, and 75 percent are involved in agriculture, either for subsistence or trade. Gross national income is just $290 a year, with 59 percent of Gambians getting by on $1 a day or less. Gambians are threatened by any number of communicable diseases, including malaria, dengue, Crimean-Congo hemorrhagic fever, yellow fever, schistosomiasis, trypanosomiasis, meningococcal meningitis, tuberculosis, acute respiratory disease, and others. Sanitation rates are low, with 82 percent of the population able to access clean water and 53 percent using adequate sanitary facilities. HIV/AIDS certainly exists in The Gambia, but there is little information on its spread or impact. The Joint United Nations Programme on HIV/AIDS (UNAIDS) does not list an adult prevalence rate for the country,
although some groups put the rate at 1.2 percent. A national coordinating committee was instituted in 2001. While communicable diseases are the most urgent threat to the health of Gambians, they are not the only ones. Diabetes is an emergent problem noted by the Secretary of State for Health and Social Welfare in mid-2007. There are an estimated 29,600 Gambians suffering from diabetes today, with about 500 deaths in the first part of 2007. The number of cases are expected to climb to 53,600 by 2025. Female genital mutilation (FGM) is another issue for Gambians. Gambia has one of the highest rates of FGM in the world, with estimates of between 60 and 90 percent of women in the county having gone through some form of the procedure. Rates seem to vary by ethnic group, with reports that 100 percent of Mandinga and Serehule women (about 50 percent of the total population) undergo FGM, along with 93 percent of Fula women (18 percent of the population). Excision is common,with some cases of infibulation. There is also a regional technique called “sealing,” about which little is known. There is an active campaign both nationally and internationally to end FGM. The fertility rate for Gambian women is 5.21 children. Only 18 percent use contraceptives. Although 91 percent receive at least some prenatal care, only 55 percent give birth with the help of trained attendants. The maternal mortality rate is 540 deaths per 100,000 births. Infant and child mortality rates have stayed steady since 1990, with 97 deaths per 1,000 for infants younger than one and 137 deaths per 1,000 for those between the ages of 1 and 5 years. Immunization rates are 88 percent for most vaccine-preventable childhood diseases. Seventeen percent of children under 5 are underweight, and 19 percent show signs of stunting. Gambia spends around U.S. $5 per capita on healthcare. There are three major hospitals and a number of community-level health centers. The University of Gambia maintains a medical school, and along with the Medical Research Council Laboratories, conducts research into a number of regional diseases, including HIV. Gambia has suffered from a “brain drain” of medical personnel in recent years, as young professionals leave the country in search of better opportunities elsewhere. There are 3.5 doctors and 12.5 nurses per 100,000 population. See also: Dengue; Female Circumcision; Malaria.
Gastroenterology
Bibliography. “allAfrica.com: Gambia: 2025—53,600
at Diabetes Risk”. allAfrica.com, allafrica.com (cited June 2007); CIA World Factbook, “Gambia” . www.cia.gov/library/publications/the-world-factbook, (cited June 2007); “Female Genital Mutilation: Gabon, Gambia, Germany, Ghana,” .ipu.org/wmn-e/fgm-prov-g.htm (cited June 2007); UNICEF. “UNICEF—At a Glance: Gambia—Statistics”. www.unicef.org/infobycountry (cited June 2007). World Health Organization; “WHO|A Guide to Statistical Information at WHO,” www.who.int/whosis/en/ (cited June 2007); World Health Organization, “WHO Global InfoBase,” www.who.int/infobase/report (cited June 2007). Heather K. Michon Independent Scholar
Gastroenterologist A gastroenterologist is a physician who specializes in the diagnosis, treatment, and management of disorders of the digestive system. The digestive or gastrointestinal (GI) system includes the esophagus, stomach, small intestine, colon, and rectum, which are the organs through which food passes in the body. It also includes the liver, gallbladder, and pancreas, which are organs directly related to the digestion, absorption, and removal of nutrients and waste. Therefore, a gastroenterologist is trained to deal with a broad range of disorders such as gastroesophageal reflux disease (heartburn), peptic ulcer disease (PUD), gallbladder and bilary tract disease, hepatitis, pancreatitis, inflammatory bowel diseases (IBD), celiac disease, and colon polyps or cancer. Both pediatric and adult gastroenterologists generally receive five to six years of training after graduating from medical school. In the United States, pediatric gastroenterologists complete their initial residency in pediatrics and then a fellowship (further specialized training) in pediatric gastroenterology while adult gastroenterologists complete their initial residency in internal medicine and then a fellowship in gastroenterology. One of the diagnostic and therapeutic tools that gastroenterologists frequently use is endoscopy. It is a specialized skill in which gastroenterologist receive extensive training and involves the use of a flexible,
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lighted tube with a built in camera in order to directly visualize parts of the upper gastrointestinal system (esophagus, stomach, duodenum) or the lower gastrointestinal system (rectum, sigmoid colon, colon). Endoscopy can be utilized for diagnosis of gastrointestinal disorders by visualization or biopsy for such things as peptic ulcers or colon cancer. It can also be used for therapeutic procedures such as dilatation for disorders of narrowing of the GI tract such as achalasia, hemostasis (to control bleeding) for a bleeding ulcer, or the removal of colon polyps. SEE ALSO: Acid Reflux; Colonic Disease (General); Esopha-
geal Disorders; Gastroenterology; Gastrointestinal Bleeding.
Bibliography. American College of Gastroenterology,
“What Is a Gastroenterologist?” www.acg.gi.org (cited October 2006); Tom MacDonald, Immunology for Gastroenterologists (Remedica, 2003).
E. John Ly, M.D. Brown University Medical School
Gastroenterology Gastroenterology is the branch of medicine that focuses on the structure, function, and diseases of the digestive system. The gastrointestinal tract breaks down food as it is digested to provide energy for the human body to function. During the digestive process, food and liquids travel from the mouth to the anus where elimination takes place. The digestive function is a complex process involving the esophagus, the stomach, the small and large intestines, the liver, the pancreas, and the gallbladder. If any part of this digestive process fails, it can lead to a host of gastric conditions that range from minor discomfort to potentially fatal malignancies. The first signs of gastric problems may be discoloration or ulcers in the cheeks, hard and soft palates, and tongue. Gastric conditions include dyspepsia, gastric reflux, bowel-related conditions, malabsorption syndromes, ulcerative colitis, Crohn’s disease, hepatitis, and malignancies of the gastric tract. Tools used in diagnosis include blood tests, gastroscopy, X-rays, and measurements of esophageal acidity and
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neuromuscular dysfunction. Treatments vary according to the condition and may include drugs, antacids or alginates, weight loss, elevation of the head when sleeping, and the elimination of smoking, alcohol, caffeinated beverages, fruit juices, and fatty and spicy foods. Surgery is used in more serious cases and may be followed by radiation and chemotherapy in the case of gastric cancers. Dyspepsia Gastric upsets are particularly common in Western countries because of nutritional and lifestyles. Approximately 10 percent of all visits to general practitioners involve gastric conditions, and 40 percent of the adult population in Western nations experience at least one serious gastrointestinal attack each year. Ninety percent of all gastric cases diagnosed by healthcare professionals are identified as dyspepsia, which is an umbrella term for gastric conditions. Dyspepsia includes indigestion, reflux (heartburn), gastritis, and duodenal and gastric ulcers. It is impossible to estimate how many people self-medicate and never seek professional help for dyspepsia. Dyspepsia can be caused by eating too quickly or eating on the move so that food is not digested properly. Stress may also be a factor in gastric disorders. Particular medications such as aspirin, nonsteroidal antiinflammatory drugs (NSAIDs), antacids containing magnesium, antibiotics, dioxin in large amounts, proton-pump inhibitors, and thiazide diuretics may also lead to dyspepsia. Diagnosis is based on observation and patient reports of abdominal discomfort accompanied by belching, bloating, flatulence, feelings of fullness, and heartburn. It may be necessary to rule out peptic ulcers. Pain associated with common forms of dyspepsia tends to be aching or uncomfortable. Sharp and stabbing pains or pain that radiates to other body parts may be indicative of more serious conditions. Symptoms that call for professional consultation include persistent vomiting with or without blood and unintentional rapid weight loss. Discomfort alleviated by pain suggests peptic ulcers, while pain relieved by food is indicative of a duodenal ulcer. Gastric reflux If the muscles at the lower end of the esophagus fail to close after contents are emptied into the stomach, gastric reflux may occur, causing partially digested food to
back up. The result is heartburn, belching, and other gastric distress. The condition could also be indicative of a hiatal hernia. Virtually all human beings experience gastric reflux at some point in their lives. Infants are particularly prone to the condition. Between the ages of birth and three months, one-half of all infants suffer gastric reflux that causes them to “spit up” undigested milk or food. Between 4 and 6 months, twothirds of all infants experience gastric reflux at least once a day. Incidences decline after eight months as the infant’s digestive system matures. In some cases, reflux may require hospitalization. Warning signs include malnutrition due to inadequate caloric intake or loss of calories through continual regurgitation, and pain, inflammation, or bleeding in the esophageal tract. Gastric reflux may also affect the airways, leading to constant hoarseness, laryngitis, cough, apnea, exacerbation of asthma, or pneumonia. Treatment for gastric reflux varies from lifestyle and nutritional changes to drugs and surgery. Elevating the head may reduce gastric attacks when sleeping. Smaller and more frequent feedings may also reduce attacks in infants. Older children and adults should avoid caffeinated beverages, peppermint, chocolate, onions, fatty and spicy foods, citrus fruits, and tomato-based products. Smoking and alcohol are contraindicated for anyone experiencing gastric attacks. Weight loss may reduce the frequency of attacks in adults and children who are obese. Conditions of the bowel All individuals suffer from bowel conditions at some point in their lives. Approximately one-fourth of the Western population suffers from irritable bowel syndrome (IBS), which is most common in individuals under the age of 45. IBS is accompanied by common symptoms of dyspepsia, lower abdominal pain, and altered bowel habits. Diarrhea, which is the most common bowel complaint, may be either viral or bacterial. It is characterized by increased frequency or passage of soft and watery stools. Diarrhea may be acute (lasting more than seven days), persistent (lasting more than 14 days), or chronic (lasting more than a month). Acute diarrhea is generally accompanied by the rapid onset of nausea and may be accompanied by nausea, vomiting, and abdominal cramping or tenderness. Patients with viral diarrhea may have a cough or cold that disappears within two to four days. In developing countries, di-
arrhea frequently results from giardiasis, a protozeal infection of the small intestine that is contracted from drinking contaminated water. This condition may also be contracted by tourists who travel to these countries. Giardiasis is characterized by watery and foul-smelling diarrhea, bloating, flatulence, and epigastric pain. Antibiotics are required to treat the condition. If diarrhea persists in individuals over the age of 50 or following travels in tropical and subtropical climates, professional help should be sought. Other trigger points include duration of more than two to three days in infants, blood or mucus in stool, rectal bleeding, and severe abdominal pain. Of itself, diarrhea is rarely life threatening, but in developing countries, acute infectious diarrhea is a leading cause of death. Persistent diarrhea may lead to dehydration, and death may care if patients are not rehydrated. Infants are particularly vulnerable to dehydration. In Western countries, liquids designed to restore fluid and electrolytes are widely available. In developing countries, access to such products is more limited. Infant mortality rates have dropped in many developing countries in response to the involvement of the World Health Organization (WHO) and United Nations Children’s Fund (UNICEF) in promoting rehydration with solutions containing sodium, potassium, chloride, bicarbonate, and glucose. It is estimated that most of the world’s children under the age of 5 will experience an attack of diarrhea caused by a rotavirus. Each year, more than 600,000 children die from the effects of the virus, and some 2,000,000 are hospitalized. In 1998, the Food and Drug Administration (FDA) approved a rotavirus vaccine that has reduced the incidences of associated dehydration by half in the United States. In 2003, a number of international organizations and the Centers for Disease Control and Prevention (CDC) joined together to reduce rotavirus-related child mortality in developing countries. Another common bowel complaint is constipation, which is characterized by a reduction in normal bowel habits. Although it may occur at any age, constipation is most common in the elderly. From 25 to 40 percent of sufferers are over the age of 65. Constipation can be caused by medications, IBS, pregnancy-related problems, difficulties encountered during potty training, depression, and colorectal cancer. If constipation is accompanied by weight gain, lethargy, coarse hair, and dry skin, it may be an indication of hyperthyroidism.
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Common treatment for constipation includes laxatives, stool softeners, and fiber. Bloody stools, constipation that endures for more than seven days, and depression call for professional consultation. Hemorrhoids (piles) may also affect bowel habits. Around 80 percent of the population experiences this condition at some time, and incidences are common among pregnant women and the elderly. Hemorrhoids are characterized by rectal bleeding, pain, and itching. Over-the-counter medications are generally effective, but more serious cases call for professional consultation. Both ulcerative colitis and Crohn’s disease are IBD, which are characterized by chronic inflammation and ulcers in the lining of the rectum and colon. With Crohn’s disease, inflammation occurs deeper within the walls of the intestine and may spread to the small intestines, mouth, esophagus, and stomach. Ulcerative colitis occurs among all age groups but is most common among individuals between the ages of 15 and 30. There is a strong genetic link with both diseases. The most frequently recognized symptoms are diarrhea and the presence of bloody stools. Other conditions Gallstones are another common cause of gastric problems and are asymptomatic in 60 percent of all cases. Since the late 20th century, most gallbladder surgeries are laparoscopic, which is less invasive than traditional abdominal surgery, and reduces postoperative effects and recovery time. Individuals who imbibe large amounts of alcohol frequently suffer from liver disease, particularly from potentially fatal cirrhosis of the liver. Hepatitis, which is an inflammation of the liver, is found in three forms. The mildest form is hepatitis A, which may be contracted by contact with infected food, objects, or stool. Because of its mildness, it may go undiagnosed. Hepatitis B is uncommon in the general population because of blood screening tests. However, it continues to occur among drug abusers who use unsterilized needles, and it may be transmitted through sexual contact or from mother-to-child during birth. Because it is viral in nature, it may lead to chronic liver disease or liver cancer. Hepatitis C is spread in ways similar to A and B, and is a chronic problem in kidney dialysis centers. The majority of patients with hepatitis C never completely recover,
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and many develop diseases of the liver. Since 1992, blood screening has significantly reduced incidences of hepatitis C in the United States. Symptoms of all three types of hepatitis include a generally feeling of malaise, fever, aching muscles, loss of appetite, nausea, vomiting, diarrhea, and jaundice. Some individuals may experience malabsorption syndromes such as lactose intolerance in which individuals are unable to properly digest dairy products. This condition, which is frequently diagnosed in infants, is characterized by loose bowel movements, fever, vomiting, and failure to grow at acceptable levels. A much rarer malabsorption condition is known as coliac disease, which renders sufferers unable to properly digest grain products. In its most often diagnosed in early infancy when cereal products are introduced into the diet and between the fourth and fifth decades or life. A gluten-free diet is mandatory for individuals diagnosed with coliac disease. Only 2 percent of cases referred to gastric specialists by internists involve malignancies. The most common malignancies of the gastrointestinal tract are colorectal cancer, pancreatic cancer, and gastric carcinoma. In the earliest stages, these conditions may not be evident. Professional help is sought only when individuals begin to have difficulty swallowing or experience unintentional weight loss. Other warning signs of possible malignancies include bloody, dark, or tarry stools, persistent changes in bowel habits, debilitating pain that persistently causes sufferers to awaken at night, and persistent vomiting with or without blood. Colorectal cancer, which has a strong genetic factor, may be accompanied by persistent diarrhea and a feeling that the bowel has not been fully emptied. See also: Acid Reflux; Alcohol Consumption; Caf-
feine; Cancer (General); Celiac Disease; Colonic Disease; Colorectal Cancer; Diarrhea; Esophageal Disorders; Gastroesophageal Reflux/Hiatal Hernia; Liver Diseases; Pancreatic Diseases; Ulcers. Bibliography. “CDC Advance Data Number 212: Preva-
lence of Major Digestive Disorders and Bowel Symptoms,” (March 25, 1992); “CDC Advance Data Number 322: National Ambulatory Medical Care Survey, 1999 Summary,” (July 17, 2001); Donald K. Cherry, et al., “Casebook: Abdominal Pain,” The Practitioner (May 31, 2006); Michael Fried, et al, “Global Guidelines: Is Gastroenterology Lead-
ing the Way?” The Lancet (December 9, 2006); Paul Hungin and Greg Rubin, Gastroenterology in Primary Care (Blackwell Science, 2000); Felicia LeClere, et al., “Key Developments in Gastroenterology,” The Practitioner (May 5, 2004); Carolos H. Lifschitz, editor, Pediatric Gastroenterology and Nutrition in Clinical Practice (Marcel and Dekker, 2002); Paul Rutter, Community Pharmacy: Symptoms, Diagnosis, and Treatment (Churchill Livingstone, 2004); Jenny du Toit, “Assessing Patients for Risk of Colorectal Cancer in Primary Care,” The Practitioner, (December 31, 2006). Elizabeth R. Purdy, Ph.D. Independent Scholar
Gastroesophageal Reflux/ Hiatal Hernia Up to 40 percent of people in Western countries are estimated to regularly experience heartburn, the most characterisitic symptom of gastroesophageal reflux disease (GERD). GERD is a digestive disorder that affects the lower esophageal sphincter (LES)—the muscle connecting the esophagus with the stomach. The LES has no anatomic landmarks, but its presence is identified by a rise in pressure over gastric baseline pressure. In normal digestion, the LES opens to allow food to pass into the stomach and closes to prevent food and acidic stomach juices from flowing back into the esophagus. The LES also relaxes when the stomach is distended with gas allowing it to vent (a belch). With GERD, however, the sphincter relaxes between swallows resulting in chronic regurgitation of acid into the lower esophagus. The inner lining of the stomach resists corrosion by acid because of specialized cells that secrete large amounts of protective mucous. The esophagus lacks this protective barrier and constant acid backwash irritates its inner lining resulting in inflammation called esophagitis. Esophagitis may lead to ulceration, narrowing of the esophagus (stricture), or cellular changes called metaplasia that are associated with an increased risk of esophageal cancer. In most cases, GERD can be relieved through diet, lifestyle changes, and over-the-counter medications. However, if the symptoms persist or worsen, patients should seek medical advice and may require more potent medications or surgery.
Signs and Symptoms Persistant heartburn, also called acid indigestion, is the most common symptom of GERD. It is a burning pain that starts in the center of the chest, and sometimes spreads upward to the neck and throat. It may be associated with a sour or bitter taste in the mouth. The pain of heartburn can last as long as two hours and is usually worse after eating. Lying down or bending over can precipitate heartburn or make it worse. Some patients with GERD do not report heartburn and rather suffer from a variety of symptoms that ranges from a bitter taste in the mouth or regurgitation of food or sour liquid to a persistant dry cough, hoarsness especially in the morning, wheezing, and asthma. These are called atypical symptoms and are the primary complaints in 20 percent of patients with GERD. Causes and Risk Factors The exact etiology of GERD is not known. Several risk factors weaken or relax the LES making reflux possible. Fatty and fried foods, chocolate, garlic, caffeine, spicy and acid foods, and mint flavorings relax the LES sphincter. Similarly, alcohol and cigarettes as well as certain medications such as nitrates and calcium channel blockers weaken the LES and increase the likelihood of reflux. Eating large meals or eating right before bedtime can also contribute to GERD. Certain medical conditons such as obesity and pregnancy are strongly associated with reflux disease. A hiatal hernia occurs when part of the stomach protrudes through the diaphragm into the lower chest. The diaphragm is the respiration muscle that seperates the chest from the abdominal cavity. Recent studies show that the opening in the diaphragm acts as an additional sphincter around the lower end of the esophagus. Studies also show that hiatal hernia results in retention of acid and other contents above this opening. These substances can reflux easily into the esophagus. Treatment The first step in treatment consists of lifestyle and dietary changes. Head elevation during sleep, weight loss, avoiding certain foods, as well as cutting down on alcohol consumption and cigarette smoking help reduce the symptoms of GERD. Antacids neutralize acid in the esophagus and stomach and provide temporary or partial relief.
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When GERD symptoms persist, medications such as histamine-2 receptor blockers (H2-blockers) and proton pump inhibitors (PPIs) are used to decrease stomach acid production. H2-blockers inhibit the histamine-induced acid production. PPIs block the protein that secrete acid into the stomach. They are more effective and more expensive than H2-blockers. Patients with GERD have an excellent response to PPIs. If symptoms continue for more than six weeks despite medical therapy, patients are further evaluated to document the extent and degree of tissue damage at the lower esophagus. Upper endoscopy is the standard procedure to evaluate esophagitis. A tissue biopsy can be obtained to check for cellular metaplasia, a condition called Barrett’s esophagus. Esophageal pH monitoring is the best study to document acid reflux, but is unnecessary in most patients with GERD. Esophageal manometric studies assess esophageal motility and determine the LES pressure. They are particularly useful in patients considered for antireflux surgery. A small number of patients with GERD may need antireflux surgery because of severe reflux and poor response to medical treatment. Fundoplication is a surgical procedure that increases pressure in the lower esophagus. It is performed laparoscopically with a low complication rate and good to excellent relief of symptoms. See Also: Acid Reflux. Bibliography. F. Charles Brunicardi, Schwartz’s Principle of Surgery, 8th ed. (McGraw-Hill, 2005 ); John L. Cameron, Current Surgical Therapy, 8th ed. (Mosby, 2004).
Elias Darido Independent Scholar
Gastrointestinal Bleeding Gastrointestinal (GI) bleeding arising from lesions in the alimentary canal can be attributed to a variety of pathological and rarely even physiologically normal conditions such as simple tearing, vomiting, or excessive coughing. The entire digestive tract, consisting of
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the esophagus, stomach, small intestine, large intestine (colon), rectum, and anus, may be susceptible to damage, with certain gut segments showing greater frequency of insult in certain diseases. Although the location of injury may be ascertained through diagnostic exam and laboratory testing, conclusive determination of the specific bleeding site usually requires endoscopy. This is also used as treatment and to resolve complications. Upper GI Inflammation/Ulcer The mucosal lining of the esophagus, stomach, and duodenum is especially susceptible to inflammation from infection, radiation therapy, damage caused by ingested materials such as alcohol and oral medications, and exposure to stomach acid and digestive enzymes. Initially, simple abrasion and erosion of the mucosal lining may be followed by a more severe lesion, which penetrates deeper layers of the gut wall, exposing blood vessels and underlying tissue. Repeated insult and resulting compensatory replacement of lining cells can also lead to the development of cancers also capable of damaging the luminal covering. The most common etiology of an inflamed esophagus is gastroesophageal reflux disease, characterized by heartburn and abnormal acid reflux due to a dysfunctional lower esophageal sphincter. In the stomach and duodenum, peptic ulcers are caused by overproduction of hydrochloric acid by parietal cells in gastric glands due to hormonal or parasympathetic nervous stimulation. A majority of cases are also strongly associated with bacterial infections of Helicobacter pylori which invade gastric pits and cause autodigestion of the stomach wall by gastric enzymes. Anatomical Malformations/ Age-Related Weakening Various anatomical malformations may also contribute to the etiology of gastrointestinal bleeding. On its course to the stomach, the esophagus passes from the chest cavity to the abdomen through a hole in the muscular diaphragm called the esophageal hiatus. In enlarged or age-related weakened openings, the upper cardiac part of the stomach herniates through the diaphragm into the chest cavity, increasing regurgitation and likelihood of bleeding characteristic of
acid reflux. In very rare cases, torsion and volvulus or twisting of the gut may cause mechanical stress induced bleeding. Diverticulitis Diverticulitis a condition associated with diet, constipation, and obesity, involves small outward herniation of the gut lining through small, natural, peripheral openings created by perforating intestinal nutrient arteries. Thin outpouches, of gut wall, are highly susceptible to perforation from fecal blockage, resulting in intestinal bleeding and other complications Lower GI Inflammation Inflammatory bowel disease is a broad category of conditions including ulcerative colitis, Crohn’s disease, and postinflectional colitis. Inflammation that arises from infection, genetic influence, immune abnormalities, stress, food allergy, or idiopathic causes may be significant enough to cause ulcerations and bleeding in the lower bowel. In Crohn’s disease, these lesions are deeper, discontinuous, and may occur along the entire digestive tract. Varices/Hemorrhoids/Polyps Veins draining deoxygenated blood from the gut tube carry newly absorbed nutrients first to the liver through portal circulation before draining into the inferior vena cava and heart for pulmonary circulation. Portal hypertension is a condition resulting in impeded blood flow to the liver, causing enlargement, thinning, and increased blood pooling and pressure in portal veins that drain the gut. The result is varicose veins, which jut out from underlying connective tissue layers into the gut lumen, becoming vulnerable to abrasion. In the esophagus and anus, which experience the greatest physical stress due to food boli and hardened stools, respectively, these exposed veins are particularly susceptible to rupture and bleeding. In a similar condition, hemorrhoids occur when anorectal veins are similarly swollen and inflamed due to strained bowel movements, not hypertension. Colon polyps are benign overgrowths in the gut lining, which also protrude into the lumen. The mechanism of injury related to bleeding is the same as that of varicies and hemorrhoids. Polyps, if left
Gaucher’s Disease
untreated, may form malignant cancers with similar bleeding pattern. Diagnosis and Treatment Bleeding that originates from the upper gut results in vomiting red blood, and stools with blood that is either black, occult, or red. Black tarry stool, also called melena, is the result of blood that has undergone bacterial breakdown by the naturally occurring intestinal flora to produce dark colored hematin. If the bleeding is slow, sometimes the invisible occult blood in the stool is detectable only by chemical tests. In bleeding that occurs more distally, near the anus, frank blood in the stool takes on a brighter red hue. The pain associated with GI bleeding may be nonexistent, poorly circumscribed, or highly localized depending on the location and severity. In general, blood tests and stool sample tests are used in the first step of diagnostic procedure to derive an etiology for the bleeding. Sometimes, the lesions are caused by bacterial or other parasitic pathogens, which are detected by these tests and resolved with antibiotics. If the cause of the bleeding is still unclear, however, endoscopy is the next step, which allows visual localization and biopsy sampling of inflamed tissues for ulcerative and precancerous cells. Endoscopic procedures, such as banding, can also be used to resolve bleeding, in cases of varicies and hemorrhoids. Other diagnostic methods include manometry, pH monitoring, and barium swallow X-rays. SEE ALSO: Anemia; Colorectal Cancer. Bibliography. Christine A. Iacobuzio-Donahue and
Elizabeth A. Montgomery, Gastrointestinal and Liver Pathology: A Volume in the Foundations in Diagnostic Pathology Series, (Churchill Livingstone, 2005); NIH/NIDDK National Digestive Diseases Information Clearinghouse, “Digestive Diseases,” digestive.niddk.nih.gov (cited April 2007); Patient Centered Guides, “Colon and Rectal Cancer,” www.oreilly.com/medical/colon/news/crc0101. gif (cited December 2005); U.S. National Library of Medicine Medline Plus, “Gastrointestinal Bleeding,” www.nlm. nih.gov/medlineplus/ency/article/003133.htm (cited December 2005). Chanukya R. Dasari Angela Garner, M.D. University of Missouri–Kansas City
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Gaucher’s Disease Gaucher’s disease (GD) is a rare genetic disease that was first described by French physician Philippe Gaucher in 1882. Despite being the most common lysosomal storage disease, it afflicts fewer than 10,000 worldwide. Caused by one of over 200 inheritable defects in the gene coding for ß glucocerebrosidase, it is also the most common genetic disease in Jews. ß glucocerebrosidase is an enzyme responsible for breakdown of glycolipids within the cell. Forms of Disease Three forms of GD have been reported. The form of disease determines the person’s symptoms and their severity. According to data from the Gaucher Registry, type 1 accounts for 94 percent of cases. Fortunately, these symptoms often manifest later in life and are less severe than the other forms. That is why type 1 GD is called the adult form. People with type 1 GD may have enlargement of the liver and spleen with the potential for subsequent destruction, reduced platelet count, anemia, reduced white blood cell count, and lung disease. The clinical course is variable and can range from barely detectable to wheelchair confinement at an early age. Forms 2 and 3 are much less common. They are not linked to the Jewish population. In addition to the symptoms suffered in type 1, GD patients with types 2 or 3 suffer neurologic squeal. Type 2, also called the infantile form, is fatal within the first three years of life. Type 3 GD, also called the juvenile form, progresses more slowly. However, it still results in neurologic problems, such as seizures and poor coordination. Diagnosis The best way to diagnose GD is with a genetic test. A doctor will send someone for this test if he or she is suspicious of GD. Some scenarios that may raise this suspicion are family history of GD, enlarged liver, enlarged spleen, or low platelet count. Genetic Screening Screening for type 1 GD is available. It is typically performed as part of a Jewish genetic screening panel, a battery of screening tests performed when a Jewish couple begins to plan for a family. This has brought up a number of ethical concerns. Will the knowledge of
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a couple’s carrier status impact the decision to move forward with a family? This carves out a niche for genetic counseling as more individuals are being screened. GD is inherited in an autosomal recessive pattern. If two parents are carriers for the same genetic mutation, the child has a 25 percent chance of having the disease. If one parent has the disease and the other does not, the child will be a carrier for GD. Treatment Imiglucerase (Cerezyme®, Genzyme) replaces the deficient ß glucocerbrosidase. It is used only in type 1 GD. Approximately 3,500 patients around the world are on this course of treatment. Enzyme replacement therapy is extremely costly, ranging from $250,000 to $600,000 annually, depending on the patient’s body mass. Again, ethical issues arise. How much is society willing to pay in order to extend life? What social obligations, if any, does the pharmaceutical industry have? Very severe cases of GD may require splenectomy if the spleen has been damaged. This is done much less frequently since the approval of Imiglucerase. SEE ALSO: Genetic Disorders; Genetic Testing/Counsel-
ing; Rare Diseases.
Bibliography. G. Anand, “Uncertain Miracle: A Biotech
Drug Extends a Life, but at What Price?” Wall Street Journal (November 16, 2005); Cerezyme Home Page, www. cerezyme.com/home; J. Charrow, et al., “The Gaucher Registry: Demographics and Disease Characteristics of 1698 Patients with Gaucher Disease,” Archives of Internal Medicine (v.160, 2000); National Gaucher Foundation, www. gaucherdisease.org/; National Organization for Rare Disorders, Inc., www.rarediseases.org. Ross E. Breitbart, M.S. Philadelphia College of Osteopathic Medicine
Gay Gene Plato may have offered the first explanation of homosexuality as an inborn trait in the Symposium, written in the 5th century b.c.e.: he suggests that all humans originally were paired, and homosexuals are the
separated halves of male-male pairs. Two pioneers of the modern study of sexuality, Karl Heinrich Ulrichs (1825–95) and Magnus Hirschfeld (1868–1935) also believed that homosexuality was an innate characteristic. Interest in discovery of a biological explanation for homosexuality remains strong in some quarters, and beginning in the mid-1990s, several scientists have announced discovery of results which would suggest a biological basis for homosexuality, although none of these claims have held up to sustained scrutiny. In 1991, Simon LeVay published results from a series of autopsies which found that the hypothalamus was smaller in homosexual men than in heterosexual men. This study has been criticized on many grounds, including the fact that the homosexual men in the study died from AIDS, which is known to affect the brain; in addition, other studies have failed to replicate his results. In 1993, Dean Hamer claimed that his studies of self-identified homosexual men and their family members suggested the presence of a “gay gene,” in this case a set of markers on the X chromosome, which was highly prevalent although not universal among the gay men in his sample. Hamer’s results received a great deal of publicity at the time, although interest has lessened as subsequent studies have failed to replicate his results and the design of his original research has been criticized. Most modern theorists believe that sexuality is a complex human behavior which cannot be reduced to a simple biological or genetic explanation. Another question whether the discovery of such an explanation would be good for the gay community. Some believe that establishing homosexuality as an inborn characteristic would lead to greater acceptance and stronger legal protections against discrimination such as that afforded to people based on their race or gender. Others argue that it could lead to further discrimination, including termination of pregnancies if a fetus was found to be carrying the “gay gene”, or early behavioral interventions on boys carrying that gene. See Also: Homosexuality; Genetics. Bibliography. Council for Responsible Genetics, “Do
Genes Determine Our Sexuality?” www.gene-watch.org/educational/genes_and_sexuality.pdf (cited May 2007); Dean H. Hamer, et al., “A Linkage between DNA Markers on the X Chromosome and Male Sexual Orientation,” Science (July 13,
Gene Array Analysis
1993), Simon LeVay, “A Difference in Hypothalamic Structure Between Heterosexual and Homosexual Men,” Science (August 30, 1991). Sarah Boslaugh BJC HealthCare
Gel Electrophoresis Gel electrophoresis, sometimes called cataphoresis, is a group of techniques used by scientists and medical researchers who separate molecules based on the physical characteristics of these molecules on the basis of their shapes, size, or isoelectyric point. Although there is no prescribed use for gel electrophoresis, the techniques are usually undertaken to partially purify molecules before they are used for a number of procedures including DNA sequencing, polymerase chain reaction (PCR) cloning, mass spectrometry, or immunoblotting. The term gel refers to the matrix used to separate the molecules, which in many instances, is a crosslinked polymer where the composition and porous ability is chosen on the weight and the composition of the target molecules being isolated. The main method of electrophoresis involves the movement of electrically charged particles in a fluid, after they are put under the influence of an electric field. If, however, the liquid instead of the particles are set into motion through use of a fixed diaphragm or through other techniques, the phenomenon is given the name electroosmosis. Although some electrophoresis techniques date from the 19th century, much of the development took part in the 20th century, with the Swedish chemist Arne Tiselius first using electrophoresis as an analytic technique in about 1930 when he was an assistant to the Sverdberg at the University of Uppsala. Tiselius was able to separate proteins in suspension on the basis of the protein’s electrical charge, thus developing the main technique still used in electrophoresis. He was awarded a doctorate for his research in 1930, and 18 years later, he won the Nobel Prize for Chemistry. Much of the current interest in electrophoresis is in human genetics with the technique being used to identify hundreds of variants of hemoglobin. The annual journal Advances in Electrophoresis reviews the literature being published in the field.
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SEE ALSO: DNA; Polymerase Chain Reaction (PCR). Bibliography. Anthony T. Andrews, Electrophoresis:
Theory, Techniques, and Biochemical and Clinical Applications, 2nd ed. (Oxford University Press, 1986); Milan Bier, ed., Electrophoresis: Theory, Methods and Applications (Academic Press, 1959–67); Barry L. Karger, Lloyd R. Snyder, and Csaba Horváth, An Introduction to Separation Science (Wiley, 1973). Justin Corfield Geelong Grammar School, Australia
Gene Array Analysis Gene array analysis is a method to simultaneously evaluate the expression of many genes. It can be used for sequence identification such as mutation analysis as well. Gene arrays are solid surfaces, such as a microscope slide, on which a number of nucleotide sequences belonging to a gene have been placed at defined locations by spotting or by direct synthesis. The aim of using this technology is to recognize the existence and abundance of labeled nucleic acids in a biologic sample, which is hybridized to the nucleotide sequences on the gene array. This technology is a very young one and is growing very fast. One of the most important features of gene arrays is the amount of quantitative data they can provide. The major challenge for using this technology is the methods that can be used for dealing with such a huge amount of data. These data can be interpreted in different ways. Bioinformatics is capable of helping to interpret the data provided by gene arrays by using mathematics, statistics, and computer science technology. In other words, gene array analysis is the analysis of data provided by gene arrays to obtain the correct interpretations and significant results. The nucleic acids attached to the array or the labeled nucleic acid of the sample are called target, while the labeled nucleic acids compromising the sample are called probes. The amount of probe hybridized to each target spot provides information about specific nucleic acid composition of the sample. A gene array experiment has the advantage of getting the information on thousands of targets in a single experiment.
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There are different kinds of gene arrays including nylon membrane arrays, glass slide arrays, and affymetrix’s gene chips. There are several terms that are used to refer to gene arrays including biochip, DNA chip, GeneChip® (Affymetrix, Inc.), DNA array, microarray, and macroarray. In general, biochip, DNA chip, or GeneChip refers to gene arrays on glass slides. Microarray and macroarray indicate the spot size or the number of spots on the slide. Gene arrays are powerful tools to compare complex sample RNA populations. For example, using array analysis, the expression profiles of normal and tumor tissues, treated and untreated cell cultures, developmental stages of an organism or tissue, and different tissues can be compared. A typical gene array experiment involves the following: 1. Isolating RNA from the samples to be compared; 2. Converting the RNA samples to labeled cDNA via reverse transcription; 3. Hybridizing the labeled cDNA to identical membrane or glass slide arrays; 4. Removing the unhybridized cDNA; 5. Detecting and quantization the hybridized cDNA; and 6. Comparing the quantitative data from the various samples. For validating the differences in expression of special genomic sequences, another method of analysis, such as RT-PCR, Northern analysis, or nuclease protection assays, is used. These procedures can be used for relative or absolute quantization of specific data recognized by gene array analysis. The most challenging part of a gene array experiment is the data analysis, which is performed with the help of computer and bioinformatics. Just one gene array experiment can offer thousands of data points. Then, making sense of the provided data is of great importance. For dealing with this challenge, the novel field of gene array bioinformatics has become available. The computational analysis of a gene array consists of several steps: image processing, normalization, and measuring and quantifying the gene array variability. During these steps, the data resulting from a gene array experiment can be interpreted. Gene array analysis by
bioinformatics methods can help to find which genes are differentially expressed in one set of samples relative to another. It can be applied to determine the relationships between genes or samples measured. It will also provide the possibility to classify samples based on gene expression measurement. SEE ALSO: Gene Pool; Genes and Gene Therapy; Genetics;
Genomic Library.
Bibliography. Ambion, “The Basics: What Is a Gene Ar-
ray?” http://www.ambion.com/techlib/basics/arrays/index. html (cited July 2007); Dov Stekel, Microarray Bioinformatics (Cambridge University Press, 2003).
Iman Tavassoly Mazandaran University of Medical Sciences, Iran Omid Tavassoly Tarbiat Modares University
Gene Mapping Gene mapping describes identifying the location of specific genes on chromosomes. It is a key step in understanding genetic diseases. The goal of gene mapping is to understand and treat genes that cause genetic disease. The Human Genome Project (HGP) was essentially completed in 2003. It was a 13-year project sponsored by the United States Department of Energy and the National Institutes of Health. Major contributions were made by China, France, Germany, Japan and Great Britain as well as others. Its goal was to build detailed guides to the type and location of all genes on chromosomes. Every human being has 46 chromosomes. Twenty-three are inherited from the mother and 23 from the father of the child. The X and Y chromosomes make the essential difference between male and female. If the chromosomes that determine the sexual inheritance are both X then the child will be a female. If one is an X and the other is a Y the child will be a male. The other chromosomes contain the genes that regulate the growth and functioning of all of the cells in the human body. The creation of a genetic map plotting the locations of genes on DNA strains of the respective chromosomes
is the goal of gene mapping. A genome is the total set of genes on chromosomes. The genome may be that of a human (human genome) or a chicken or pig (chicken genome and pig genome). When researchers begin the process of gene mapping there is nothing on the map. As the genome is investigated the chromosomes are identified and the respective genes are also identified and their location plotted on their respective chromosomes. The end product is a complete map reporting the location of all the respective genome’s genes and the DNA sequencing of the bases of each gene. Genetic markers are fragments of DNA that identify differences in strains. The genetic markers are unique sequence-dependent patterns or DNA. The ordering of the different bases in genes is made by observing recombinant frequencies. The makers are somewhat like finger prints because of their unique characteristics. It was estimated that there were between 50,000 and 100,000 genes in humans. However, the number of genes turned out to be much smaller. The number of genes is only between 20,000 and 25,000. The additional goal of determining the sequences of the three billion chemical base pairs that make up human DNA was also a goal. There are two ways to do gene mapping—genetic mapping and physical mapping. Gene mapping identifies the order of genes along each chromosome. Genetic mapping analyzes the locus of genes on chromosomes. The locus of a gene (loci of genes) on a chromosome can allow it to be linked to another gene, in which case the two genes are “linked.” If genes are not linked to each other although linked to the chromosome then they are separated by an independent assortment. Alleles are the sequences of chemical units that compose the genetic sequence of the gene. The loci may be the genetic inheritance of both the father and the mother of the human whose genetics are being mapped. The genes may have different loci, but during DNA crossover there may be a recombination of loci so that the order of the genes on the chromosomes is changed. The closer two genes are the less likely recombination is to occur. This failure to recombine is due to the fact that recombination frequency is more likely to occur when there is a chiasma between the two loci. If two DNA molecules are homologous and they combine the new combination is called DNA crossover. During meiosis if two homologous pairs of sis-
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ter chromatids align side by side then DNA crossover is likely to occur. The point at which two homologs connect is the chiasma. This is where the two homologs exchange DNA segments. The exchange is from the chiasma to the end of the chromosomes. If during the DNA exchange the sequences of chemicals on the DNA do not match exactly on the chromatid then the exchange will be an unequal crossover. The effect is to mis-code the genetic sequence. Physical gene mapping techniques are more precise than those used in gene mapping. The methods seek to establish the distances of genes on the chromosome and their distance from each other. Physical gene mapping include somatic cell hybridization and fluorescent in situ hybridization (FISH). Both the gene mapping and the physical mapping methods use genetic markers. These are specific physical or molecular features that differ among individual people. These markers are also transmitted genetically to succeeding generations. Physical mapping seeks to understand the process of DNA replication. When DNA replicates it creates a group of clones, but it does not have to replicate all of the DNA. With a map the clones are used to map the workings of the whole genome. The clones allow for the visualization of stretches of DNA in operation. Once mapping is completed genes can be investigated for a number of features. The most common is to identify the location of genetic disorders on genes. Then the investigation seeks to find ways to overcome the gene deficiency. There are many diseases that are genetically based. These include achondroplasia, agammaglobulinemia, albinoism, ankylosis, cellac disease (celiac sprue), Huntington’s Chorea, Christmas disease (hemophilia B), cystic fibrosis, Downs syndrome, dwarfism, Ehlers-Danlos syndrome, epilepsy, Friedreich’s ataxia, Gaucher’s disease, hemolytic disease of the new born, hemophilia, Hirschsprung’s disease (megacolon), Klinefeiter’s syndrome, myotonia congentia, osteogenesis imperfecta, phenylketonuria, polycystic kidney, sickle cell anemia, Tay-Sachs disease (gangliosidosis), Thalassemia (hemolytic anemia), Turner’s syndrome (gonadal dysgenesis), Von Recklinghausen’s disease (neurofibromatosis), Wilson’s disease, and many others. The process of identify the genetic locations responsible for genetically based diseases is also a form of gene mapping. It requires development of
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Gene Pool
a very fine map of the base sequences on the gene responsible for the disease. It can also be used to investigate the origin and the manifestation of genetic disease in large families. For these data it is also possible to project the demographics of the disease in the general population. There are numerous benefits that will be harvested in the short run from gene mapping. Among these are contributions to molecular medicine, environmental applications, advances in anthropology and especially in bioarchaeology which seeks to trace the linage of people, forensic DNA and the precise identification of criminals, and advances in agriculture, livestock breeding and other bioprocesses. Advances in genome science now being applied to all plants and animals are making biology the great science of the 21st century. It has created a biotech industry that producing billions of dollars in goods and services in the near future. See Also: Genetic Code; Genetic Testing/Counseling;
Genetics.
Bibliography. Minou Bina, ed., Gene Mapping, Discov-
ery, and Expression: Methods and Protocols (Springer-Verlag, 2006); T.A.A. Brown, Genomes 3 3E (Taylor & Francis, 2006); Ian Dunham, ed., Genome Mapping and Sequencing (Horizon Scientific Press, 2003); Lawrence B. Schook and Haris A. Lewin, eds., Gene-Mapping Techniques and Applications (Marcel Dekker, 2001); Matt Ridley, Genome: The Autobiography of a Species in 23 Chapters (HarperCollins, 2006); David Siegmund and Benjamin Yakir, The Statistics of Gene Mapping (Springer-Verlag, 2007). Andrew J. Waskey Dalton State College
Gene Pool In a population of sexually reproducing organisms, a gene pool is the sum of that population’s genetic material at a given time. In terms more specific to a particular genetic locus on a chromosome, it is the sum of the alleles in a population at that locus. As is currently posited by the “Out of Africa” hypothesis, the species of homo sapiens, and its gene
pool, began as a relatively small group of individuals (roughly in the hundreds) in east Africa. Over some tens of thousands of years, some groups left Africa and increasingly populated the rest of the world. This hypothesis finds wide agreement by modern evolutionary theorists. At the end of the 20th century, it has also found strong confirmation from the molecular genetic and chromosomal studies of population origins that have mapped the specific route taken by different human subgroups or races throughout evolutionary time. Evolution is the change in composition of a population’s gene pool. This can occur by a variety of mechanisms, including mutations, natural selection, and genetic drift. As populations left Africa, each faced different environments, different novel diseases, diets, and climates. To the extent that this was the case, over time, the surviving composition of each subpopulation’s gene pool was altered to be attuned to the needs of its specific environment. Two well-studied examples are illustrative of this point. As a population moved away from the equator where the average amount of sunlight (and also the risk of skin cancer) is less, over time pigments in the skin were selected to allow more translucency per sunlight exposure. This allowed a more efficient manifestation of the endogenous synthesis of vitamin D, an absolutely critical vitamin for proper human bone development and therefore proper childbirth. Second, as Europeans domesticated new animals and increasingly relied on such animals for sustenance, they had to evolve the enzymes necessary to digest specific novel nutrients (lactose). It is interesting to note that most of the world is lactose intolerant because the gene for the enzyme to digest lactose originated in Europeans. As populations change or evolve in response to different environments, their gene pools are changing their composition and character. Evolutionary “fitness” is defined not from the perspective of the human person but from the unconscious perspective of the gene: it is the ability to pass on one’s genes, the ability to reproduce. Because populations often face difficult and rapid changes in their environments (e.g., famine, plagues, ice ages as in Eurasia 20,000 years ago, social selection, etc.), the advantages gained in fitness by the adaptive specificity of a gene pool must be balanced by
Gene Silencing
the risks posed to evolutionary fitness by too narrow of a genetic profile. A large and diverse gene pool allows a greater chance for future adaptation to an ever-uncertain environment. SEE ALSO: Allele; DNA; Genetic Code. Bibliography. Richard Dawkins, The Selfish Gene (Ox-
ford University Press, 1976); Jared Diamond, Guns, Germs and Steel (Norton, 1999); Richard Leakey, The Origins of Humankind (HarperCollins, 1996); Nicholas Wade, Before the Dawn: Recovering the Lost History of Our Ancestors (Penguin, 2006). Omar Sultan Haque Harvard University
Gene Silencing Gene silencing is a process in which a gene is switched off. It is different from gene mutation. In fact, in gene silencing the mechanisms regulating gene expression are changed so that the gene will not be expressed and, in other words, the gene expression is down-regulated or the gene is turned off. It is believed that innate gene silencing has been a tool for protecting the genomes of organisms from infectious DNA elements such as viruses during the evolution. In other words, gene silencing has been an innate cellular immune surveillance system. Gene silencing has been proposed as a method for gene therapy in different diseases. Because genes are regulated by transcriptional and posttranscriptional mechanisms, gene silencing can be a transcriptional or posttranscriptional procedure. Gene silencing at the transcriptional level is made by creating an environment with modified histone proteins. In this environment, gene cannot be expressed because of changes in transcriptional agents. For gene silencing at the posttranscriptional level, the messenger ribonucleic acid (mRNA), which is the transcriptional result of that gene, must be destroyed to stop translational process. There are different methods for gene silencing at the transcriptional and posttranscriptional levels. Using oligodeoxynucleotides is a way for performing gene silencing as a therapeutic tool. Synthetic
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oligodeoxynucleotides are used for gene-specific expression interruption. Introduction of gene-specific oligodeoxynucleotides with their binding to target gene or mRNA inhibits transcription or translation of that specific gene. This strategy is called antisense strategy. Another strategy, which is called antigenene strategy, is based on avoidance of interaction between transcription factor and a target gene which will result in inactivation of that gene. The most famous gene silencing method is RNA interference (RNAi) which has brought hopes for gene therapy of many diseases. The discovery of RNAi has been one of the transforming events in biomedical sciences. This novel technology can result in gene silencing or even omitting functions of specific sequences from the genome. RNAi technology involves introduction of double-stranded RNA result in inhibition of gene expression at the posttranscriptional level. In order to target mRNA for destruction and perform a posttranscriptional gene silencing, short interference RNA (siRNA) or silencing RNA is used. siRNA is a short oligonucleotide of about 19 to 23 nucleotides with a high specificity for target genes which are supposed to be turned off. There are many ongoing trials to test the capability of RNAi for curing several diseases such as cancers and AIDS. Although gene silencing is an ancient immune cellular system, man-made gene silencing technology is a state-of-the-art approach for meddling with specific gene expression with applications in treatment of many important diseases. SEE ALSO: DNA; Gene Pool; Genetic Code; Genes and
Gene Therapy; Genomic Library.
Bibliography. Roman Gardlik, et al., “Vectors and Deliv-
ery Systems in Gene Therapy,” Journal of Medical Sciences Monitor (v.11/4, 2005); Gregory J. Hannon and John J. Rossi, “Unlocking the Potential of Human Genome with RNA Interference,” Nature (v.431, 2004); Wei Lv, Chao Zhang, and Jia Hao, “RNAi Technology: A Revolutionary Tool for the Colorectal Cancer Therapeutics,” World Journal of Gastroenterology (v.12/29, 2006). Iman Tavassoly Mazandaran University of Medical Sciences, Iran Omid Tavassoly Tarbiat Modares University
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Gene Transfer
Gene Transfer Gene transfer is the process of transferring genetic material from one cell to another by mechanical or surgical means. This process can help overcome the problems inherent in finding or manufacturing viruses which might be used to transfer the material and offers a genuine opportunity to redress some of the issues concerning genetic disease. Vertical gene transfer involves moving genetic material from a cell to its successor, while horizontal or lateral gene transfer involves the transfer of material among cells which do not have such a relationship. Scientific understanding of the role and nature of genes in single-celled organisms was more or less complete by the end of the 1960s. Since then, researchers have been working on expanding understanding to higher organisms. Although many advances have been made, the complexity of genetic interactions and bodily functions means that there have also been many failures and even deaths resulting from clinical trials. Inserting genetic material via virus has proved to be more difficult than anticipated because the human body has spent millennia fighting to resist viruses and the legacy of this conflict is multifactorial and difficult to document exactly. Clearly, those researchers who could discover breakthroughs and convert this knowledge into marketable treatments for pharmaceutical companies would find their careers transformed into glittering success and this, together with the need to obtain research grants, can produce pressure on scientists to work with maximum speed and at the limit of understanding. It is clear that bacteria contain genetic material that may have been spliced together from quite unrelated or at least diverse organisms. The altered genetic material has led to quite distinct changes in the ecological niche which the bacteria has subsequently occupied. To some extent, these changes are understood and can be manipulated to create distinctive forms of bacterial life. If the same processes can be more properly understood in more complex life forms and the changes that would be brought about therefore predicted, then it would be possible to modify living creatures, including people, in whatever ways might be desired. It is obvious that this would have major benefits in that it could assist people suffering from genetically inherited diseases and conditions. However, a number of social and ethical issues need to be resolved to determine wheth-
er the same technology would be deemed acceptable to root out other genetic conditions which some may consider undesirable—obesity, perhaps, or unattractive features. It is clear that even if this technology became sufficiently well established as to make it available on an open market, prohibitive costs are likely to rule it out from all but the most wealthy members of the most wealthy societies, at least for the foreseeable future. This brings about additional equity issues that should be considered. SEE ALSO: Gene Pool; Genetic Code; Genes and Gene
Therapy; Genomic Library.
Bibliography. Horace Freeland Judson, “The Glimmering Promise of Gene Therapy,” Technology Review (v.109/5, 2006); Harold Ochman, Jeffrey G. Lawrence, and Eduardo A. Groisman, “Lateral Gene Transfer and the Nature of Bacterial Innovation,” Nature (v.405, 2000).
John Walsh Shinawatra University
Generic Drug Generic drugs, sometimes known colloquially as generics, are drugs that are bioequivalent to a brandname drug with respect to the pharmacokinetic and pharmacodynamic properties. However, because of the registration of brand-name drugs, generic drugs tend to be sold at a much lower price, enabling health service providers and customers to make substantial savings. Generic drugs and medicines have to have exactly the same active ingredient as the brand-name versions and must meet identical pharmacopeial requirements for preparation. They also must be of exactly the same strength and use the same method of administration, safety, efficacy, and intended use. The sole reason for the use of generic drugs is to allow drugs to be made at a much cheaper price or to make drugs available that are not elsewhere for whatever reason. The reason why they are cheaper is that the company making the generic drug has generally not been involved in the extremely expensive research and development of drugs, the costs associated with obtaining regulatory approval in various countries,
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Although generic drugs are said to be identical as brand-name drugs, in terms of having the same medical properties, some people have found adverse reactions to changing from medication with brand-name drugs to generic drugs. In some countries such as Australia, patients are allowed to ask for brand-name drugs or request that pharmacists substitute it with a generic drug to alleviate any of these problems, both actual and perceived. SEE ALSO: Pharmacist; Pharmacologist; Pharmacology;
Pharmacopeia/Pharmacopoeia; Pharmacy.
Bibliography. M. Laurence Lieberman, The Essential
Generic drugs allow drugs to be made at a much cheaper price and make drugs available that are not elsewhere.
Guide to Generic Drugs (HarperCollins, 1986); Donald L. Sullivan, The Consumer’s Guide to Generic Drugs (Berkley Publishing Group, 1996). Justin Corfield Geelong Grammar School, Australia
and also the cost of marketing these drugs, and making medical professionals around the world aware of their existence and use. As a result, makers of generic drugs do not have to go through the lengthy process of developing drugs and spending resources on drugs which are later found to be unsuitable. Furthermore, they do not need to undertake clinical trials—the test for a generic drug is solely that it has exactly the bioequivalent makeup as the original. The making of generic drugs is legal in three circumstances. The first and major use is when the original patent for the brand-name drug as expired or there has never been a patent issued. The second instance is when the generic company certifies that the original brand-name drug patents are invalid, unenforceable, or will not be infringed. Generic drugs are also made when the patent for the brand-name drug is not enforceable in the country where the generic drugs is being manufactured and sold. To preempt the expiry of patents, many drug companies producing brand-name drugs produce their own generic product or license their own product to be made by generic companies. In a few cases, some countries have also allowed their own manufacturers to produce generic drugs to treat major diseases when the health service of that country has not been able to fund the cost of brand-name drugs. This has happened recently in Brazil and Thailand.
Genes and Gene Therapy Genes are chemical compounds that act as genetic codes. They instruct cells to make proteins. Each gene is a collection of DNA (deoxyribonucleic acid) in sequence. DNA molecules are long double-helix molecules resembling a spiral staircase. The steps in the spiral staircase were fixed at conception when the individual inherited 46 chromosomes from two parents (23 from each). The steps consist of pairs of four types of chemicals. Each is a molecule called a base (nucleotide). The four types are adenine (A), thymine (T), guanine (G), and cytosine (C). The genetic code of each individual is written in triplicate so that the combination of A with G or G with C or T creates sequences such as AAA, or AGT or GCT. The genetic codes are so arranged that they instruct the manufacturing of one of twenty amino acids. For example, the sequence GCT is the code for the manufacture of amino acid lysine. Each gene codes for the manufacture of one protein. This means that each gene is a stretch of DNA in a coded sequence. The sizes of genes vary. The size depends upon the size of the molecule that it is coded to manufacture.
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Obvious inherited characteristics are hair, skin, or eye coloring. These inherited characteristics are the product of the genes acquired at conception. Some traits are regulated by more than one gene. Each gene contains a set of nucleic acid molecules that comprise a set. The segment contains the coded information needed to produce a functional RNA (ribonucleic acid). The gene uses the coded information in an orderly manner. The code includes information in the segments that acts as rules directing the manufacturing of another molecular product. The gene also has in is program regions that carry instructions on how to function. The genetic makeup of an individual is a genotype. The genotype contains information for the physical development of the body. Phenotype is the name for the manner in which the genotype is expressed (phenotype expression). The interaction of the genes with each other and with the environment (e.g., food available, minerals in water, and other environmental factors) guides the physical development of the individual.Genes are the units of genetic inheritance. Often more than one gene is involved in the expression of the genetically determined characteristics of an individual. For some reason genes normally contain noncoding regions. genes and DNA The genes in cells are composed of a long strand of DNA. A promoter region controls the activity of the gene. The code also controls gene products that are used by the body. The code contains a sequence or a set of instruction for engaging in the process of transcription. The transcription process creates an RNA copy of the gene’s code. The RNA then directs the synthesis of proteins using the code. Gene expression is the gene using its code to manufacture gene products that are either a protein or an RNA copy. During RNA transcription the DNA molecule splits open along its length. One strand of the DNA molecule will be inactive. The strand becomes a template that is used to form an RNA molecule. The bases of the RNA are arranged in the same sequence as are the bases of the inactive strand of DNA with one difference. The RNA contains uracil (U) instead of thymine (T). In the next step of replication, the RNA copy becomes the messenger RNA (mRNA). The mRNA RNA acts as a template for protein synthesis. An RNA polymerase II in the nucleus of the cell uses protein
coding to a precursor RNA which contains the intron sequence that will be removed by splicing. It separates from the DNA and travels into the cytoplasm of the cell. In the cytoplasm it combines with a ribosome. The ribosomes are the cells manufacturing centers for making proteins. The mRNA in the next step instructs the ribosome to construct an amino acid which will be used to make a protein. The amino acids are freefloating chemicals in the cytoplasm. A transfer RNA (tRNA) brings them into what becomes a growing chain of proteins. The molecule chain will be folded into the exact shape needed because it is influenced through close by chaperon molecules. When cells divide DNA replicates itself. The DNA helix unravels. Step by step, a new molecule of DNA is formed. The replication leads to the formation of a new cell which then divides into two new cells. During DNA helix replication, it is possible for a mutation to occur. If the mistake is severe enough, the cell will die. Most mutations are trivial and will not have any significant consequence. However, some changes can introduce changes that may be detrimental or beneficial in some cases. When mutations that are deleterious mistakes occur these may affect only the individual. However, if the mistake affects the germline cells that are involved with reproduction then there can be genetic consequences that contribute to the expression of genetic disorders in the offspring. Humans have cells that are eukaryotic organisms, that is, most of the cells of the body contain chromosomes which contain the genes needed to do the chemical reactions which transfer energy, build tissue, reproduce and other activities of life. There are in the genes of eukaryotic organism noncoded regions (introns). When RNA transcription is taking place these are spliced away by the RNA messenger by regions called exons. The result is that a single gene can used different exons to produce differing splicings that then produce different proteins. gene therapy technology The Human Genome Project, completed in 2003, put the number of genes in the human genome at 20,000 to 25,000. The exact number is close to 20,500. The number was a surprise because earlier estimates had imagined a much larger number. The number of base pairs residing in the DNA double helix is estimated to be nearly three billion pairs.
Gene therapy is a new technology which seeks to change the function of some genes in individuals in order to cure or prevent certain diseases. At the present time gene therapy is still experimental in most of its forms. The goal of gene therapy is to replace or repair defective genes that cause disease. In the case of some diseases such as immune deficiency diseases sample cells of the immune system are taken from the patient. The cells may be in the patient’s blood or bone marrow. The normal gene is inserted into the cells form the patient. The replacement cells are then grown in a laboratory. When there is a sufficient supply they are reintroduced into the patient. In other forms of gene therapy the cells are fixed within the cell inside of the patient. Some diseases such as diabetes, hemophilia, and cystic fibrosis are caused by defects in the genetic code inherited from the parents of an individual. The therapy seeks to replace the defective genes with a healthy genetic code. The modified genetic code will then replicate itself in the cells of the individual being treated. However, it will not prevent the transmission of the defective gene(s) to offspring. Gene therapy has the potential to counteract a health gene. In diabetics this would mean that the cells of the islets in the pancreas that are no longer producing insulin would be replaced with genes that would then instruct the pancreas to manufacture insulin. The health benefits if successful would be enormous. The focus of gene therapy is upon the most fundamental level of biochemistry. For example the gene which causes type 2 diabetes mellitus has been identified. Research into the transference of genetic material into the chromosome that carries the gene is being conducted which if successful would restore some or all of the individual’s ability to manufacture insulin. Somatic gene therapy is research into gene therapy has been limited so far to targeting specific cells in the body. These are called somatic cells. When somatic gene therapy is successful it alters the genetic code or makeup of the individual. The changes in characteristics however, will not be transmitted to succeeding generations. Germline gene therapy seeks to produce changes in the individual’s genetic code that would alter genes and also make them transmissible to succeeding generations. So far, they have not been successfully developed.
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A major challenge for gene therapy is to develop methods for delivering the genetic material that will be the new genetic code. Genetic code is the genetic information that is present as a biochemical language. A genetic code is present in all living things including humans, animals, plants, bacteria, fungi and viruses. The genetic code is used by the DNA molecule to instruct cells to do specific functions. Or in the case of noncellular organism such as viruses the code instruction the interactions that replicate the virus usually to the detriment or death of the cell in which it is living. Using viruses to deliver the gene therapy is one strategy that is being explored. The virus will have been effectively neutralized as a harmful agent. It will then have been spliced so that the genetic code that will be the gene that is therapeutic is added to the virus. The part of the virus’ genetic code that is harmful will be spliced off rendering it harmless. The virus will when implanted in the body invade the specific cell tissue it normally effects but will instead add the genetic material that will give beneficial instructions to the cells of the tissue. The deliver systems of viruses make them strategically interesting vectors. Research is currently in progress to develop viral vectors for genetic therapy. Another strategy is the use of chemicals that act as vehicles to deliver the needed genes as chemical messengers. The chemical vehicle or chemical “vector” delivers the genetic material to the target cells. The chemical vector reacts with the target cells so that the gene therapy can become a part of the target cells. The first experiments with gene therapy were aimed at two genetic diseases. These were the inherited forms of immune deficiency in children and a genetic disorder that causes very high levels of serum cholesterol in both children and adults. The American Society of Gene Therapy (a nonprofit medical and science organization) has reported that X-linked immunodeficiency has been treated successfully with foamy viruses as vector in gene therapy. X-linked severe immunodeficiency (SXCID) is a rare genetic disorder which results from defects in the immune hormone receptor (common gamma chain). It is found on the surface of lymphocytes and immune blood cells. Patients with SXCID usually develop fatal infections in infancy unless they undergo a bone marrow transplant. However, in a percentage of
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cases the bone marrow transplant is ineffective. The new therapy holds considerable promise children suffering from SXCID. In the early 1990s gene therapy was attempted on patients with severe combined immune deficiency (SCID). The first two patients chosen for gene therapy were chosen because bone marrow transplants had indicated that replacing the defective gene was possible. In addition, studies with mice had indicated that enzyme replacement therapy was a model that gene therapy could follow. However, most of the first 3,000 patients with a variety of immune diseases were not helped significantly. Since 2000, advances in understanding the human genome and advances in understanding the immune system have aided the effectiveness of bone marrow transplants. However, they have not provided a permanent gene therapy cure for SCID victims. Researchers have been able to develop a gene therapy in mice for the immune deficiency disease agammaglobulinemia which is X-linked (XLA). The disorder affects only males. The researchers were able to identify the specific defective gene, and were able to replace it with a therapeutic gene. Research has not yet advanced enough to be applicable to humans. Stem cell transplantation is being used to treat individuals with T cell defects. The defect interferes with the victim’s body’s ability to ward off disease. The immune system is defective because of the genetically inherited defect. The use of stem cell is taken from the umbilical cord upon the birth of a normal infant. The blood containing the stem cells is transplanted into the immune deficient recipient. The procedure has met with some success. Two forms of SCID have been proven as successful treatments side effects have kept them from active use in the United States. The use of gene therapy is also only for genetically caused illnesses. In the future, it might be possible to use gene therapy for a wider range of diseases. Early experiments with gene therapy were also conducted upon cystic fibrosis (CF) patients. CF is caused by a defective gene which interferes with the balance of salt/water balance in the lungs. The CF gene is designed to manufacture a protein that will regulate the flow of salt and water in and out of the cells of the lungs. Instead, in CF patients the protein is dysfunctional. It causes the air passages to accumulate thick, sticky mucus. The mucus is an inviting en-
vironment for bacteria. Infections that occur damage the airways and the lungs. The gene therapy used to treat CF is targeted at the mucus linings of the lungs of the patient. The vectors used at first were viruses that are known to cause respiratory infections. While there was some risk of respiratory infection this was an inviting choice of vectors. Current research on animals using a non-viral vector has been successful in reducing the DNA molecule as a compacted molecule to the point where it can penetrate the cell wall membrane. This allows the therapeutic DNA molecule to enter into the cell nucleus. The goal is to deliver a gene which will manufacture enough protein to counteract the CF protein deficiency that causes breathing problems. The gene transfer method if successful will open a new way to treat many forms of genetic disorders. Gene therapy has been used to treat single cell disorders such as hemophilia, muscular dystrophy and sickle cell anemia. These therapies are still very experimental. Other applications of gene therapy include cancer treatments, heart disease and some infectious diseases. Gene therapy has also been investigated for infectious diseases such as AIDS. See Also: Gene Mapping; Gene Pool; Genetic Testing/
Counseling.
Bibliography. Roman Espejo, Gene Therapy (Thomp-
son Gale, 2004); Linda George, Gene Therapy (Thompson Gale, 2006); Anthony J. F. Griffiths, et al., Introduction to Genetic Analysis (W. H. Freeman Company, 2007); Leland Hartwell, Michael L. Goldberg, and LeRoy Hood, Genetics: From Genes to Genomes (McGraw-Hill, 2000); Benjamin Lewin, Genes IX (Jones & Bartlett, 2007); Jeffrey R. Morgan, ed, Gene Therapy Protocols (Springer-Verlag, 2001); Clay Farris Naff, Gene Therapy (Thompson Gale, 2004); Michael A. Palladino and Mary Colavito, Gene Therapy (Benjamin Cummings, 2006); Sandy B. Primrose, Giuseppe Bertola, Bob Old and Richard Twyman, Principles of Gene Manipulation (Blackwell Publishers, 2005); Matt Ridley, Genome: the Autobiography of a Species in 23 Chapters (HarperCollins, 2006); Gabor M. Rubanyi and S. Yla-Herttuala, eds., Human Gene Therapy (SpringerVerlag, 2003). Andrew J. Waskey Dalton State College
Genetic Brain Disorders Genetic brain disorders are defined as disease states that affect the differentiation and function of the neuroectoderm and its derivatives via defective genes. The Human Genome Project has suggested that there may be approximately 30,000 genes. In a particular disease, there may be one or more defective genes that contribute to the particular brain disorder. The defect may be a gain of function or loss of function. The inheritance of these defective genes may be autosomal dominant, autosomal recessive, sex-linked recessive, or mitochondrial. Many of these brain disorders not only affect the brain, but also affect many other organ systems. Hereditary genetic disorders involving the central nervous system may have a wide variety of clinical presentations, including that of developmental delay, neurological or developmental regression, varying levels of consciousness, multisystem involvement, and focal neurologic deficits. Inborn Errors of Metabolism The study of genetic brain disorders was largely established when Archibald Garrod published Inborn Errors of Metabolism in 1923. Inborn errors of metabolism are uncommon individually, but occur quite frequently when taken as a whole. Collectively, there is approximately 1 in 1,400 to 1 in 5,000 disorders per live birth. The incidence among different racial and ethnic groups varies among the diseases. They are often due to defective genes that regulate enzymes or transport proteins. These diseases can be divided into the following categories: carbohydrate metabolism, amino acid metabolism, organic acidemias, lysosomal storage diseases, fatty acid metabolism, and mitochondrial disorders. Most of these disorders are of autosomal recessive inheritance. The presentation of the disease can vary even within each specific disease type, ranging from differing ages of onset to variable levels of clinical severity. Various types of inherited disorders will result in differing mental deficits. For example, the psychoses and hallucinations may be due to any of the following disorders: lysosomal defects (Sanfilippo and Hunter diseases, GM2 gangliosidosis, neuronal ceroid lipofuscinosis, Krabbe disease), purine metabolism defects (Lesch-Nyhan syndrome), peroximsomal defects (adrenoleukodystrophy), Wilson’s disease, acute intermittent porphyria, and homocystinuria. Developmental
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delay may also result from metabolic defects such as lysosomal defects, disorders of amino acids, organic acids, carbohydrates, copper metabolism (Menke’s disease, Wilson’s disease), and peroxisomes (adrenoleukodystrophy, Zellweger syndrome). Seizures and ataxias can manifest secondary to metabolic diseases. It is important to diagnose and treat patients with inborn errors of metabolism because a delay in either may lead to long-term neurologic impairment. Patients should also be referred to appropriate counseling, as there exist many profession and peer support groups for individuals with these disorders. Genetic counseling should also be offered to evaluate recurrence risks, familial screening, and prognosis. Hereditary Movement Disorders Hereditary movement disorders may include neurologic deficits such as ataxia, dystonia, and chorea. Ataxia is the inability to maintain posture or smooth movement. Dystonias are defined as diseases that cause an abnormal muscle tone, while choreas are diseases associated with involuntary spastic movements. The differences in disorders are largely due to the gene and location of the gene deficits. The spinocerebellar pathways are involved in the majority of hereditary ataxia syndromes. These disorders can be associated with three different types of mutations. One set of diseases is due to nucleotide triplet repeat expansions. A common nucleotide expansion is that of the nucleotides cytosine; adenine and guanine are repeated which results in a polyglutamine tail as in the spinocerebellar ataxias and Huntington’s disease. Huntington’s disease is characterized by chorea, dementia, and psychiatric symptoms. Other hereditary ataxias include dentatorubral-pallidoluysian atrophy (DRPLA, also known as Haw River syndrome or Naito-Oyanagi disease), Friedreich’s ataxia, adrenoleukodystrophy, and Refsum disease. Movement disorders may also be due to defects in the mitochondrial DNA. Mitochondrial disorders are due to defects in either the nuclear- or mitochondrialencoded mitochondrial proteins. These defects are passed to subsequent generations via nonmendelian inheritance. Specific examples of mitochondrial diseases include Friedreich’s ataxia, mitochondrial myopathy, encephalopathy, lactic acidosis, stroke syndrome (MELAS), ataxia with selective vitamin E deficiency (AVED), and X-linked ataxia with sideroblastic anemia.
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Finally, diseases may be due to defects in DNA repair. In particular, ataxia telangiectasia mutated protein, aprataxin, and senataxin are proteins involved in DNA repair that can be altered to cause movement disorders. Specific examples of these mutations include ataxia telangiectasia, ataxia with oculomotor apraxia types 1 and 2, and spinocerebellar ataxia with sensory neuropathy (SCAN1).
recessive disorder characterized by epilepsy, ataxia, and myoclonus. Tuberous sclerosis complex is another inherited epilepsy disorder. It has autosomal dominant inheritance and is associated with hamartomas in the skin, lung, heart, kidney, and brain.
Muscular Dystrophies Duchenne muscular dystrophy (DMD) is an Xlinked autosomal recessive disorder that presents in early childhood. The disease is caused by a mutation in the dystrophin gene on the X chromosome. It is a rapidly progressive disease that is associated with muscle weakness, mental retardation, and cardiomyopathy. It often leads to patients being wheelchair-bound before they reach their teenage years and often results in death by the second to third decade of life.
Bibliography. T. N. Feraro, D. J. Dlugos, and R. J. Buono,
Motor Neuron Disorders Motor neurons are the cells that control voluntary muscle activity. Diseased motor neurons cause difficulty with voluntary movement. Many of these diseases are hereditary in nature and are associated with neurologic symptoms. For instance, Kearns-Sayre syndrome (KSS) is a maternally inherited disorder causing progressive ophthalmoplegia, atypical pigmentary retinal degeneration, heart block, ataxia, and dementia. Myoclonus is another symptom of motor neuron disease and can be associated with brain disease as in myoclonus epilepsy with ragged red fibers (MERRF). These patients also inherit the disease maternally and demonstrate myoclonus, ataxia, seizures, dementia, and hearing loss. MELAS syndrome is also associated with motor neuron disease, as described above. Epilepsy Epilepsy is a seizure disorder defined as the occurrence of two or more unprovoked seizures. Seizures are caused by the abnormal hypersynchronous firing of neurons in the brain. Seminal works by Fritsch, Hitzig, Ferrier, and Caton in the 1870s initiated the development of the epilepsy field. Seizures have many etiologies, some which have genetic components. Progressive myoclonus epilepsy (Unverricht-Lundborg type) is one form of inherited epilepsy. It is an autosomal
SEE ALSO: Huntington’s Disease; Metabolic Disorders;
Wilson’s Disease.
“Role of Genetics in the Diagnosis and Treatment of Epilepsy,” Expert Reviews of Neurotherapeutics (v.6/12, 2006); G.F. Hoffman, W.L. Nyhan, and J. Zschocke, Inherited Metabolic Diseases (Lippincott Williams & Wilkins, 2002); C.R. Scrivner, et al., eds., The Metabolic and Molecular Bases of Inherited Disease, 7th ed. (McGraw-Hill, 1995). Darrin J. Lee University of California, Irvine
Genetic Code The genetic code governs the production of protein synthesis in the cell by mapping DNA (deoxyribonucleic acid) sequences to proteins that are utilized for various cellular functions. The process of protein synthesis does vary between prokaryotes (single-cell organisms; i.e., cyanobacteria, E. coli) and eukaryotes (multicellular organisms; i.e., animal, plant); however, both cell types are characterized by the processes of transcription and translation that are mediated by the genetic code. In the eukaryotic cell, chromosomes are located within the nucleus of the cell. These chromosomes contain DNA that are composed of sequence(s) of the basic unit of genetic information—the gene. Governed by noncoding and coding sequences, the gene plays an integral role in the encoding of proteins. The essential component of the gene is the segment or portion that is necessary for transcription to produce the RNA (ribonucleic acid) transcript, being the mRNA (messenger RNA), to serve as a carrier of genetic information from DNA to the ribosomes for the production of proteins. Translation guides amino acid (protein building blocks) production by the sequence of nucleotide
Genetic Disorders
triplets, called codons, that stem from the RNA transcript. The RNA transcript is produced in the cell’s nucleus and during this process three other types of RNA molecules are manufactured: tRNA (transfer RNA), rRNA (ribosomal RNA), and snRNA (small nuclear RNA). With the exception of snRNA, all RNA molecules eventually leave the nucleus via the nuclear pores and are involved in the process of translation that occurs mainly outside the nucleus. The snRNA are components of spliceosomes, which aid in removing introns (noncoding sequence) from the genetic sequence of DNA. The snRNAs interact with other subunit nuclear proteins to form these spliceosomes. The tRNA molecules are composed of 70 to 90 nucleotides that fold and are representative of another triplet nucleotide sequence, called the anticodons, that base pairs with complementary codons of the mRNA molecule on the ribosome for translation and the production of amino acids and the polypeptide chain —resulting in the synthesis of proteins. Thus, the “coding” defined by the triplet base pairing of codons and anticodons is instrumental for the production of a particular amino acid and subsequent protein. SEE ALSO: Chromosome; DNA; DNA Repair; Genet-
ics; Gene Mapping; Gene Pool; Gene Silencing; Gene Transfer; Genes and Gene Therapy; Genetic Disorders; Genetic Transformation; Genetics; Genome; Genomic Imprinting; Genomic Library; Genomics; Genotype; Watson, James. Bibliography. Jeremy M. Berg, John L. Tymoczko, and
Lubert Stryer, Biochemistry, 5th ed. (W.H. Freeman, 2002); Harvey Lodish, et al., Molecular Cell Biology, 5th ed. (W.H. Freeman, 2003); Tom Strachan and Andrew Read, Human Molecular Genetics, 3rd ed. (Garland Science/Taylor & Francis Group, 2003). Dino Samartzis, DSc, MSc, Dip. EBHC Harvard University and Erasmus University
Genetic Disorders Genetic disorders are medical conditions that are caused by errors in the replication of genetic code. Genetic diseases may be evident at birth, while others will
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only be manifested later in life. Some involve inconveniences, while others are life threatening or fatal. There are many diseases caused by genetic abnormalities. They create deformity, disease or a tendency to develop certain diseases. Genetic disorders include achondroplasia, agammaglobulinemia, albinoism, ankylosis, cellac disease (celiac sprue), Huntington’s Chorea, Christmas disease (hemophilia B), cystic fibrosis, Downs syndrome, dwarfism, Ehlers-Danlos syndrome, epilepsy, Friedreich’s ataxia, Gaucher’s disease, hemolytic disease of the new born, hemophilia, Hirschsprung’s disease (megacolon), Klinefeiter’s syndrome, myotonia congentia, osteogenesis imperfecta, phenylketonuria, polycystic kidney, sickle cell anemia, Tay-Sachs disease (gangliosidosis), Thalassemia (hemolytic anemia), Turner’s syndrome (gonadal dysgenesis) Von Recklinghausen’s disease (neurofibromatosis, Wilson’s disease, and many others. Some genetic disorders such as myopia, color blindness or inherited blepharitis (Seborrheic blepharitis) have mild symptoms. Other genetic diseases such as cystic fibrosis (CF) have severe symptoms. In some cases of inherited diseases such as Huntington’s Chorea, death is an inevitable result. Prion diseases (spongiform encephalopathies) such as fatal familial insomnia (FFI) are genetic disorders that are also fatal. Some genetic disorders arise from a single gene. For this to occur, it is necessary for the single-gene disorder to be carried on a dominant gene. The dominant gene can express the disorder from a single gene. In the case of a recessive gene, two copies of the gene are needed for it to be expressed. The abnormality is expressed as the production of too little or too much of a particular protein. Genetic diseases may be rare disorders or they may be common. They can be the result of a mistake in the genetic coding of a single gene, or they may involve the whole chromosome. The mistakes may be the result of a reproduction in the mitochondria (self-reproducing) part of cells, or the mistake(s) may be due to chemical or radiation exposure. Radiation exposure included both atomic radiation and natural sunlight. Skin cancer is the most common type of cancer in United States, South Africa, and Australia. Fair-skinned people, who are exposed to strong sunlight, especially in childhood, are likely to develop some form of skin cancer after the age of 65. They ultraviolet radiation (UV) exposure damages the skin and creates mistakes in the
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genetic reproduction. Artificial sources of UV light such as tanning beds are also sources of skin cancer. Abnormalities in genes are common. They are more common in recessive genes than in dominant genes. All human beings carry abnormal genes. On average, each person has from six to eight abnormal recessive genes. Normally these genes are inoperative or do not cause a problem. Only if there is an inheritance from both parents of the same abnormal gene is there a problem. It is the presence of two copies of the abnormal gene that creates genetic disorders. In the human population at large, there is only a small likelihood that a person will have two copies of an abnormal recessive gene. However, in cases of children born to parents who are close relatives is the risk high. In groups of people such as Orthodox Jews in come communities, and Amish and Mennonites who have intermarried for some generations, the risks are much higher. Abnormal genes that create genetic disorders may be inherited. However, they may also be the result of some spontaneous action that caused a mutation in the genetic code of the gene. The spontaneous mutation may be the result of several causes or of no identifiable cause. In cases where the mutation does not affect the reproductive cells the mutation will simply die out with the individual. However, if the mutation is included in the reproductive cells then the mutation will be transmitted to offspring. Gene mutation that produces an abnormal gene may or may not be a “bad” event. The mutation is a matter of interpretation. For example, sickle cell anemia is an inherited blood disease found among people with African, Mediterranean, and Middle Eastern heritage. It is caused by the inheritance of two copies of the abnormal gene. Sickle cell anemia affects the hemoglobin (protein in red blood cells) of the red blood cells. These carry oxygen to all parts of the body. People with sickle cell anemia have inherited two copies of the abnormal gene. It causes their red blood cells to change shape from a flexible disk-shaped cell into one that is less flexible and is shape like an oldtime farm sickle (crescent moon shaped). The sickle shaped hemoglobin cells eventually clog blood vessels and prevent oxygen from reaching all parts of the body. The sickle cells are fragile and break down easily creating fatigue. People with a single sickle cell gene have the sickle cell trait. It does not cause the disease, but it does afford protection from malaria.
Some genetic disorders can occur at conception which may be so severe that the fetus does not survive or the infant if carried to full term does not survive. These mutations are rare, but the mutation dies with the individual. The mutation, as tragic as is the loss of the individual to family and friends, is not transmitted to the next generation. Mutations that affect radically the immune system are also in this category of severe mutations. Sometime mutations can give an advantage. It may be that a mutation improves the ability to survive in the local environment including the diseases prevalent in the environment. The effect is to increase the survival potential of succeeding generations. For example, people who have genes that produced an immune system that was able to withstand and to recover from a severe influenza strain while many others dies will transmit genes that are better for succeeding generations. If one parent has an abnormal gene and the other does not, then each child has a 50 percent chance of inheriting the abnormal gene. However, if one parent (rare occurrence) has two copies of the abnormal gene, then all of the children will inherit the abnormality. If only one parent has the abnormality and a child is born without the abnormal gene, then it will not transmit it to any offspring. For those who inherit the gene in a single copy, the odds are again set at 50 percent for the offspring (grandchildren) inheriting the gene assuming that the child mate does not have the same abnormal gene. In the modern world, medical advances have led to the survival and the reproduction of many people with inherited genetic disorders. Juvenile diabetes was until recent times fatal in childhood. Other hereditary disorders also prevented the individual from living long enough to reproduce and to thus transmit the disorder to their offspring. The net effect is that natural selection has been modified by human interference. It means that there is an increase in the number of individuals in the “gene pool” who have significant genetic defects. So the number of people born with genetic disorders can be expected to rise. See Also: Genes and Gene Therapy; Genetic Brain Disor-
ders; Genetic Testing/Couseling.
Bibliography. Suzanne B. Cassidy, Management of
Genetic Syndromes (Wiley, 2004); Muin J. Khoury, Julian Little and Wylie Burke, Human Genome Epidemiology:
Genetic Testing and Counseling
A Scientific Foundation for Using Genetic Information to Improve Health and Prevent Disease (Oxford University Press, 2003); Robert L. Nussbaum, et al., Thompson & Thompson Genetics in Medicine (Elsevier Science, 2004); Joel L. Spitz, Genodermatoses: A Full Color Clinical Guide to Genetic Skin Disorders (Lippincott Williams & Wilkins, 2004); Helga V. Toriello, Robert J. Gorlin and William Reardon, eds., Hereditary Hearing Loss and Its Syndromes (Oxford University Press, 2004). Andrew J. Waskey Dalton State College
Genetic Testing and Counseling Genetic testing is the use of biochemical and cytological techniques to determine the carrier and disease status of an individual with regard to any number of genetic or chromosomal states which may manifest themselves in disease states. Genetic counseling is the provision of information and assistance to individuals (consultands) who are, or may be, affected by a disease of genetic origin. Consultands may themselves be suffering from a disease, may be a relative (usually a parent) of such an individual, or may have questions about their own carrier status (typically for purposes of reproductive planning). Advice given in genetic counseling includes calculation and interpretation of pretest and posttest probabilities (both for development of disease and of disease appearance in offspring) as well as provision of information and advice on follow-up actions individuals might take given their newfound knowledge. Common Genetic Tests Because genetic testing is neither universal nor inexpensive, genetic testing methods vary widely by geography and available resources. As a broad distinction, genetic testing may be divided into cytological and molecular techniques. The principle cytological method in genetic testing is the karyotype. Karyotyping examines the gross appearance of all 46 chromosomes. While not able to detect point mutations, this method can detect abnormalities caused by unequal crossing over or nondisjunction. The latter are a class of abnormalities caused when meiosis is abnormal and subsequent
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fertilization leads to cells with either more or less than two of a particular chromosome. Syndromes caused by nondisjunction which can be detected by karyotyping include Down syndrome and Turner’s syndrome. Among molecular techniques, the most accurate is gene sequencing where various methods are used to determine the exact base sequence of a relevant locus. While sequencing allows precise determination of genotype, it is not always appropriate. Because sequencing is not cheap, it is not feasible to sequence an entire genome. Instead, counselors and/or physicians work with consultands to determine the region of DNA that should be sequenced. More commonly, when many different loci are of interest, tests are done that determine the presence or absence of specific alleles known to cause or cosegregate with disease. Such testing methods, unlike sequencing, cannot confirm the presence of a wildtype allele, only the absence of specified mutant alleles. Key Principles and Events Generally, patients are not told what decisions to make regarding the various testing and management options. Instead, they are given information and support and empowered to make their own decisions. This is known as the principle of nondirective counseling and has been widely adopted as standard practice, particularly in North America and western Europe. It should also be
National Human Genome Research Institute researcher Milton English, Ph.D., using a pipette to load DNA into a gel.
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emphasized that although the activities of counseling are commonly described in relation to genetic testing, counseling requires the ability to identify and address complex psychosocial issues associated with both the disorder of interest and the family of the consultand. The events in genetic counseling case management can be broadly classified into four chronological phases: collection of information, assessment, counseling, and follow-up. Genetic counselors collect information on family history and medical history as well as work with consultands to determine which further tests to order. In assessment, this information is combined with a physical examination to validate or establish a diagnosis. The counseling phase can only begin when this information has been established either definitively or in a probabilistic manner. The nature and consequences of the diagnosis are explained with emphasis not just on the consultand, but on the consequences for relatives. In the case of potential parents, the risk to current and future children is also explored. Decisions about case management and referrals to other health professionals are also made in this phase. Finally, responsible genetic counseling entails follow-up for psychosocial support and to help assess and incorporate emergent information into improved case management. SEE ALSO: American Society of Human Genetics (ASHG);
Down Syndrome; Turner’s Syndrome.
Bibliography. D.L. Baker, J.L. Schuette, and W.R.
Uhlmann, A Guide to Genetic Counseling (Wiley, 1998); R.J.M. Gardner and G.R. Sutherland, Chromosome Abnormalities and Genetic Counseling, 2nd ed. (Oxford University Press, 1996); R.L. Nussbaum, et al., Thompson & Thompson: Genetics in Medicine, 6th ed., revised reprint (Saunders, 2004). Bimal P. Chaudhari Boston University
teration of the genetic makeup. It was first discovered in 1928 by Dr. Frederick Griffith, and subsequently in 1944, Drs. Oswald T. Avery, Colin M. MacLeod, and Maclyn McCarty demonstrated that the gene transfer in bacteria Streptococcus pneumoniae was through DNA. Nowadays, genes from unrelated species can be combined in laboratories using molecular biology techniques which facilitate production of therapeutics such as insulin. In single-cell organisms such as bacteria, genetic transformation can be achieved in laboratory setting using strains such as Escherichia coli. Foreign genetic materials can be transferred to these bacteria either naturally or artificially. Some species of bacteria routinely take up foreign genetic materials from their surrounding environment that is thought be used as a source of nucleotides. It has been suggested that this uptake of foreign genetic information might have been developed through evolution to allow the organisms to gain ability to adapt to their environment. The second way to accomplish genetic transformation in organisms is via artificial methods utilizing either thermal (heat shock) or electrical (electroporation) means. Both methods involve making the cell walls permeable for the entry of genetic material, such as DNA, into the cells. In multicell organisms, such as plants, genetic transformation can also be achieved using particle bombardment or biolistics, which involves coating small gold or tungsten particles with DNA and then shooting them into plant cells. This process randomly incorporates DNA of interest into the plant genome. In addition, foreign DNA can be introduced into mammalian cells DNA via transfection (heat shock or liposome-based methods), microinjection (injection of DNA directly into the cells using tiny needles), or viral transduction (delivery of genetic material packaged in virus to target host cells). Mammalian cells can sometimes be rendered tumorigenic when viral genes, such as oncogenes, transform normal cells into those with abnormal cellular appearance and properties regulating growth, proliferation, or differentiation.
Genetic Transformation
SEE ALSO: Avery, Oswald Theodore; Cancer; Gene Trans-
Transformation is the consequence of the introduction and incorporation of foreign genetic material, such as DNA or RNA, into a cell that brings about al-
Bibliography. Bruce Alberts, et al., eds., Molecular Biology of the Cell, 4th ed. (Garland, 2002); J.F. Jackson and H.F.
fer; Genetics.
Genetics
Linskens, eds., Genetic Transformation of Plants (SpringerVerlag, 2003). Stephen Chen University of Toronto
Genetics Genetics is the branch of biology that studies heredity. The passing of biological information from parents to offspring occurs through the combination of genes that are unique to each individual person, animal or plant that reproduces through living cells. As a field of study, it is concerned with the origin of individual characteristics and the way that these are transmitted to offspring. Genetics has developed over the centuries from the view of Aristotle and others that the species are fixed. One ancient idea being that inside of the seed of a man was another tiny little man. Inside of his seed was another tiny little man and so on through the generations. Charles Darwin’s ideas on evolution sparked controversy in part over how it was possible for species to develop into different animals from “lesser” species. The prevailing view in his time was that of Jean-Baptiste Lamarck (1744–1829) who had viewed heredity as proceeding according to natural laws, in particular through “acquired characteristics.” His theory which was also accepted by Darwin and by others until the discovery of the ideas of Gregor Johann Mendel (1822–84) was recognized at the beginning of the 20th century. A particularly notorious result of the Lamarckian understanding of Darwinism occurred from its adoption into social and political ideas. Herbert Spencer adopted the idea of evolution directed by the acquired characteristics of human beings to his socioeconomic theory. Followers like William Graham Sumner brought his ideas to America where they were used with a moral component added to justify the capitalism of the Robber Barons and others in the late 19th century. The Supreme Court also incorporated the idea into its rulings. The effect of Social Darwinism was to say that the successful (the rich) are the evolutionarily advanced and the poor are those that should be left to die because society will be better for it. Other politi-
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cal theories also adopted this view. The rediscovery in 1900 of a paper published by Gregor Mendel, an Augustinian monk from Moravia set modern genetics on the path of genes as the bearers of inheritance. Mendel’s work as a gardener revealed to him that pea plants inherited traits. The traits came from the parents to the offspring. Having practiced gardening in his youth between 1850 and 1863 he grew and test over 29,000 pea plants (Pisum sativum). He observed that all traits were not inherited by the offspring, just some of the traits of each parent. He was able to show the genetic inheritance of the pea strains. One in four of the pea plants had pure bred recessive alleles. Two out of four were hybrids and one out of four was the dominant purebred type. He show that the inheritance of traits followed laws. These laws have since become known as Mendel’s Laws of Inheritance. He published his theory (“Experiments on Plant Hybridization”) in an obscure journal in 1866 (Proceedings of the Natural History Society of Brunn) in Brunn, Moravia (now Brno, Moravia). His theory was ignored until 1900 when the importance of his work was recognized. His paper was republished in a journal with an international readership. The development of statistics in the 20th century along with the gene theory enable a modern evolutionary synthesis to occur that when combined with the revealing of the structure of DNA and the mapping of the human genome has made it possible to understand the specific genetics of an individual and to trace the genetic heritage of people and animals to distant ancestors. Genetic information is located in the base sequences in the genes that are attached onto the DNA double helix. The constitute codes are read as gene expressions when the cells decode the information in order to manufacture proteins that cells need to function. In order to synthesize a protein a complementary RNA molecule is produced. Its sequence orders a specific amino acid sequence of the protein. The codes of the amino acids are 64-base triplets called codons. The codons encode the 20 possible amino acids. Most of the amino acids have more than one codon. The codons are synonyms if they encode the same amino acid. The “wobble” position is on the third base which can vary so that there are initiation codons and three stop codons. Humans who have identical copies of a particular gene are described as being homozygous. Those with
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two different copies of a gene are described as heterozygous. As genes are copied they undergo mutations. Variant genes are called alleles. In describing alleles life scientists use the convention that dominant variant genes are designated with a capital letter, while recessive variants are designated with a lower case letter. In the Mendelian genetic theory each inherited trait is a phenotype. All of the phenotypes are the result of specific genes or combinations of genes. In other words genes define the unique characteristics of individuals. All of the phenotypes are the sum of the genotype which constitutes the individual human or creature. If the phenotypes produce hybrids then one phenotype will probably dominate another. Purebred lines of genes are strains of species that have been bred as exactly the same for generations. For example, breeds of dogs or cattle or grape vines are selectively bred for characteristics that aid agriculture or other needs. The breeding seeks to maintain the same phenotype so that, for example, a Concord grape or a Scottish Terrier is the same from generation to generation. Crossbreeding of pure-breed types (homozygous) line will have different inherited characteristics. They will have offspring that will all have the same phenotype. The technical term for this cross-breeding is the F1 generation. The second generation (F2) will show the original phenotypes in a ratio of 3:1. The dominant phenotype will be the majority of the prodigy. Purebred lines are organisms that have been inbred for many generations. Stock breeders breed cats, dogs, cattle, sheep, or other kinds of animals for a variety of purposes. There are strains of laboratory animals such as mice, rats, flies, and other animals or plants are used for experimentation with virtually fixed genomes that permit replication of experiments in any laboratory in the world. dominance Dominance within species arises between differences in the phenotype for one inherited characteristic. Hybrids produced from two different phenotypes produce offspring with only one phenotype. For example, experiments with short-winged fruit flies and long winged fruit flies have shown that when bred they produce only long-winged offspring. Mendel’s studies of pea plants showed that the offspring inherited several phenotypes. Focusing in on only the color of the petals, he crossed plants with
white petals with plants with violet petals. The offspring of the first generation F1 (first filial) all inherited violet petal flowers. This demonstrated that the violet color was dominant to the white petal color. He then allowed the F1 generation of offspring to self fertilize. The resulting F2 (second filial) offspring has both violet and white petal flowers. However, the colors were in a ratio of 3:1 (monohybrid ration) in which the violet color was three and the white color was one. Other experiments with crossbreeding show the same off spring ratio which led Mendel to conclude that the inherited trait was biological which today are called genes. The monohybrid ratio is the basis for all pattern of inheritance in organism higher than peas. The 3:1 phenotype ration will be a 1:1 ration if an F1 individual is crossed with a homozygous recessive parent. The crossing will produce gametes with either a dominant or a recessive gene. A testcross is produced from a recessive parent crossed with the phenotype to determine if it is heterozygous. This ratio is important because in families with genetic diseases such as Huntington’s disease the dominant allele is rare. As a result, the individual with the allele will not likely be homozygous. Instances of partial or incomplete dominance also occur. For example snapdragon with white petals is crossed with a red petal parent the result will be a pink flower rather than the dominant ratio (F1). The next generation (F2) will produce red, white, and pink petal flowers. Co-dominance occurs with crossbreeding as well. It is a departure from standard Mendelian order. When two alleles of a gene product are two distinct and detectable then they product is the results of co-dominance. Human MN blood typing is a commonly cited example of this phenomenon. This blood type is distinct from the common A, B, O, AB typing. The antigen formed by responses to antibodies that are found on the red blood cells identifies this type. The MN blood groups have two types of antigens. These two types are produced by the inherited alleles. People who are genetically heterozygotes inheritance produces both antigens and are classed as MN. When co-dominance occurs, both alleles contribute equally to the phenotype. In contrast, in cases of incomplete dominance, the two alleles contribute unequally to the phenotype. When Mendel studies the genetic characteristics of the succeeding generations
of peas he developed a concept of genetic inheritance based upon only two different alleles. When his work was rediscovered, life scientists soon found that nature was much richer than Mendel’s theory had proposed. Indeed, there are cases of genes with three, four, and occasionally more alleles. To investigate two alleles is a challenge, but the process becomes very complicated when more than two alleles have to be considered. In the case of the color of rabbit fur, the gene for color has four alleles. The ratio produced is similar to incomplete dominance. There is a difference in that both alleles are dominant. This characteristic is found in blood groups that are inherited. In humans, the MN blood group is controlled by a single gene. Dominance, co-dominance, and incomplete dominance affect human health. Some of the alleles carried on the genes of some humans affect their viability. In many cases the homozygous recessive does not survive. However, the heterozygotes may have a normal lifespan. If there is a phenotype that is observable such as yellow coats in mice, then the consequences can be observed. Yellow coats are dominant to black coats in mice. However, when two yellow-coated mice breed their offspring die in utero. This particular allele is lethal. There is a nuance that is significant in this instance. In yellow coated mice the allele that produces a yellow coat is dominant. However, in terms of viability, it is recessive. This is an important principle that occurs in many other alleles. In the developmental genes, many that are mutations produce changes if one is present, but if two copies of the same allele are present, the outcome is lethal. In humans, Tay-Sach’s disease, Huntington’s disease and sickle cell anemia are diseases that manifest this genetic characteristic. In some cases, semi-lethal genes are present. If a homozygote is present in a crossbreeding but is present in only reduced numbers, it is an alternation of the 3:1 ratio established by Mendel. Because many genes have a large number of alleles, there are also possibilities of variants that are not fatal. The ideas developed by Mendel were developed in the first part of the 20th century. While the procedures have not been altered much since then, understanding DNA and the mapping of the human genome has created a huge number of polymorphic markers that enable useful genetic analysis.
Genetics
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Polymorphism in DNA sequences when identified allows alterations in DNA sequences to be understood. DNA polymorphisms are grouped into different classes and can be used in forensic genetics. They can also be used of other purposes as well. genetic coding The genetic code is universal. It applies to all organisms which use the same codons for the same amino acids. However, as ever in nature exceptions can be found. Genes are measures of the response of each individual to the environment. Genes are inherited from parents usually without any genetic accidents. However, in rare cases mutations occur. These are variations in the copying the genetic sequence(s) which serves as a code. The “mistake” mars the expected genetic outcome. Some mutations are nonconsequential. Others are beneficial. Others are harmful or even fatal. Genetic defects can occur spontaneously, be chemically induced, or caused by excessive exposure to radiation. The vast numbers of individuals that are born without any genetic defects is an improbably high number. Medical genetics is field of study that deals with genetic defects which cause diseases through heredity. Diabetes and hemophilia are two such inherited diseases. Genetic diseases are a diverse group of genetic disorders. They are caused by one or more genes. Among the disorders are neurofibromatosis, hemoglobinopathies, thalassemias, Charcot-Marie Tooth Disease, multifactorial disease, and other disease. To identify genetic diseases, genetic screening is used. Its use however, is surrounded with ethical issues. Recent research has indicated that cancer is genetically related. However, it also seems to be the case that there are DNA repair genes and tumor suppressor genes as well which use an in-activator gene. Because altered patterns of RNA are often found in tumors, it is currently thought that mutations in the introns or exon splice sites are responsible. Genes that have been identified as cancer causing are termed oncogenes. Other areas of genetic research or applications of genetic knowledge include gene therapy with the introduction into cells copies of the necessary genetic code that will end or reawaken the appropriate genetic code. The biotechnology industry is also the product of modern genetic research. Plants and animals have been the subject of extensive research and now development
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Genital Herpes
from genetic engineering. A major goal is the production of biologically useful proteins. Recombinant DNA is used to produce natural proteins. In addition, cloned genes are to produce proteins with modified amino acid sequences. Transgenic is the creation of useful plants and animals with altered genomes by the transfer of new genes. Cloning may be the ultimate act of genetic development. However, genetic work is filled with ethical issues arising from a respect for life. SEE ALSO: Genetic Code; Genetic Disorders; Genetic
Testing and Counseling.
Bibliography. Helen V. Firth, Judith G. Hall, and Jane A
Hurst. eds., Oxford Desk Reference Clinical Genetics (Oxford University Press, 2005); Leland Hartwell, et al., Genetics: From Genes to Genomes (McGraw-Hill, 2000); Bruce R.R. Korf, Human Genetics: A Problem-Based Approach (Blackwell Science, 2006); Robert L. Nussbaum, Roderick R. McInnes, and Huntington F. Willard, Thompson & Thompson Genetics in Medicine (Elsevier Health Sciences, 2007); Eberhard Passarge, Color Atlas of Genetics (Thieme Medical Publishers, Incorporated, 2006); Matt Ridley, Francis Cricket: Discoverer of the Genetic Code (HarperCollins, 2006); D. Peter Snustad, and Michael J. Simmons, Principles of Genetics (Wiley, 2005); Tom Strachan, and Andrew P. Read, Human Molecular Genetics (Taylor & Francis, 2003); Peter Turnpenny, and Sian Ellard, Emery’s Elements of Medical Genetics (Elsevier Health Sciences, 2007); Spencer Wells, The Journey of Man: A Genetic Odyssey (Random House, 2004); Spencer Wells, Deep Ancestry: Inside the Genographic Project (National Geographic Society, 2006). Andrew J. Waskey Dalton State College
Genital Herpes Genital herpes is a sexually transmitted infection caused by the herpes simplex virus type 1 (HSV-1) and type 2 (HSV-2). Although most individuals are asymptomatic, following a two-week incubation period, patients will present with painful blisters surrounding the genitals and rectum. HSV-1 also commonly causes sores around or in the lips and mouth; these sores are known as cold sores. HSV-2 can also cause oral sores,
although these are not as common. The genital blisters will break, forming ulcers that can take up to four weeks to heal. Subsequent outbreaks, especially in those infected with HSV-2, can occur in the following months or even years, although outbreaks tend to decrease in frequency and severity over time. Other symptoms might include swollen glands in the genital region, painful urination, vaginal discharge, fever, or headache. Genital herpes infections usually do not cause serious long-term health problems. Genital herpes is transmitted by contact with an infected sore, typically via sexual contact. Unlike some other sexually transmitted diseases, using condoms does not provide complete protection against transmission, as the condom may not cover the entire area. Using condoms, however, will cut down on transmission rates even if they are not 100 percent effective. Although close skin-to-skin contact can transmit these viruses, they are not transmitted via toilet seats, towels, or other forms of casual contact. Women seem to be slightly more susceptible to infection than men. Pregnant women can also pass genital herpes to their babies, who can subsequently have serious eye, skin, or brain problems, although the risk of transmission is low, especially if the woman is diagnosed and treated prior to delivery. Although there is no cure or vaccine for genital herpes, antiviral drugs can decrease the risk of viral transmission as well as reduce the severity and frequency of herpes outbreaks. These drugs include acyclovir, famciclovir, and valacyclovir. The drug valtrex can also reduce the likelihood that an infected person will pass the disease on to a noninfected sexual partner. Reducing the frequency and severity of herpes outbreaks is especially important in patients who are also at risk of HIV infection, as coinfection with an actively ulcerating sexually transmitted infection such as herpes greatly increases the chances of HIV transmission. Partly because transmission can occur even when a patient is not actively infectious or even aware of the infection, genital herpes is quite common in most populations. In the United States, approximately 25 to 30 percent of the adult population carries the HSV1 or HSV-2 viruses, and incidence rates have been rising over time. Prevalence rates in other countries can range from 2 to 74 percent, and are generally much higher than those of other sexually transmitted diseases such as syphilis or gonorrhea. Although data
Genomic Imprinting
are often scarce, many studies show that prevalence of herpes in countries outside the United States has also been increasing steadily since the 1970s, especially in Africa and countries of the former Soviet Union. Promoting many of the measures that prevent HIV transmission will also help decrease herpes transmission, including condom use (although, as noted above, condoms are not as effective in preventing herpes as they are in preventing HIV), reducing the number of sex partners, and effectively treating active infections. Because herpes is an important cofactor of HIV infection, treating herpes infections is an important way to help cut HIV transmission rates. See also: National Center for HIV, STD, and TB preven-
tion (NCHSTP); Sexually Transmitted Diseases.
Bibliography. Genital Herpes—A Medical Dictionary,
Bibliography, and Annotated Research Guide to Internet References (ICON Health Publications, 2004); Hunter Handsfield, Genital Herpes (McGraw-Hill, 2001) Lawrence R. Stanberry, Understanding Herpes: Revised Second Edition (University Press of Mississippi, 2006)
Annie Dude University of Chicago
Genomic Imprinting Genomic imprinting is an important process that occurs in some genes in the human genome wherein a gene is differentially expressed depending on whether it has been received from one’s mother or one’s father. Such “parent of origin” effects are only known to occur in sexually reproducing placental mammals. Imprinting is one of a number of patterns of inheritance that do not obey the traditional biallelic Mendelian rules of inheritance, which assume indifference about the parental origin of an allele. Traits are, therefore, able to be passed down maternal or paternal lines. Imprinting Mechanisms One mechanism by which a given imprinted gene in an individual is differentially expressed is that one of the gene’s parental alleles is silenced throughout the
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embryonic development of the individual by an alternation in parental DNA made during parental gametogenesis. The other parental allele is, therefore, allowed expression during embryonic development. An epigenetic mechanism by which this occurs is DNA methylation (the labeling of a –CH3 group to specific regions of DNA) at imprinting control regions (ICRs). Intracellular DNA reading mechanisms exist after fertilization to check that the correct parental allele has been allowed differential expression. Imprinting and Fetal Development Imprinting has been able to explain a number of predicaments of life in utero as experienced by mother, father, as well as offspring. A number of imprinted genes are related to the manner in which the developing human must extract resources from its environment. As experimental work has confirmed predictions made by Robert Trivers’s theory of parental investment, unfortunately, mother and father have different interests in how resources are extracted. Fathers and mothers have asymmetrical parental investment in each given child. This arises from the fact that mothers can only have one child every nine months for approximately 20 years, whereas a father could conceivably impregnate a different woman every day from puberty until death. Systematic knockout studies of key imprinted genes, especially as performed on mice, have provided support for the hypothesis that imprinted genes that allow expression of paternally inherited alleles tend to drive more extraction of nutrients from the mother during gestation and after birth to produce a larger child. In contrast, imprinted genes that allow expression of maternally inherited alleles will tend to drive mechanisms to prevent the disproportionate utilization of resources by the fetus. A commonly cited example of this differential resource transfer is the paternally expressed Igf2, which enhances fetal growth and placental nutrient transport capacity, and the maternally expressed Igf2 receptor, which degrades excessive Igf2. Many of the effects of imprinted genes occur at the placenta, a crucial site for resource and nutrient transfer. For example, an overgrown placenta (hydatidiform mole) results when maternal imprints are missing. Additionally, in Silver-Russell syndrome, a maternal uniparetal disomy, one finds growth restriction. Similar effects are found in other cases of
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disordered imprinting, as in preeclampsia, which also demonstrates growth restriction in utero. These diseases can only be understood within the context of imprinting as a common mechanism of parental conflict and manipulation of the phenotypic outcome of children. Imprinting and Cognition and Behavior after Birth Although only approximately 100 human genes are presently known to be subject to parent of origin effects, these prove to have tremendous implications for the development and eventual adult attributes of the human, including its cognitive and behavioral attributes. Imprinting effects, like other genetic expression patterns, need not be only all or none, but also may manifest as earlier age of onset effects or changes in severity. In Turner’s syndrome, a parent of origin effect exists in social and intellectual functioning. The phenotypic female (XO) could have received her only X chromosome from her father (Xp) or her mother (Xm). Xp Turner’s women—who received a paternally derived X (the same as every non-Turner’s woman)—were shown through surveys to display greater attributes of social intelligence. These data were confirmed by higher performance on tests of verbal IQ and social inhibition when compared to Xm Turner’s women. Xm Turner’s women—who receive a maternally derived X (which non-Turner’s males always receive from their mothers)—performed better than Xp Turner’s women on measures of visuospatial function. Other prominent cognitive and behavioral manifestations of the effects of imprinting are seen in a number of neuropsychological disorders, including autism and schizophrenia, and can help explain such varied phenomenon as motor tic complexity in Tourette syndrome when relevant imprinted genes are maternally inherited (and greater verbal tic complexity when paternally inherited). SEE ALSO: DNA; Gene Silencing; Turner’s Syndrome. Bibliography. D.P. Barlow, “Gametic Imprinting in
Mammals,” Science (v.270, 1995); M. Constância, G. Kelsey, and W. Reik, “Resourceful Imprinting,” Nature (v.432, 2004); A.R. Isles and L.S. Wilkinson, “Imprinted Genes, Cognition and Behavior,” Trends in Cognitive Sciences (v.4,
2000); R.L. Trivers, “Parental Investment and Sexual Selection,” in B. Campbell, ed., Sexual Selection and the Descent of Man, 1871–1971 (Aldine, 1972). Omar Sultan Haque Harvard University
Genomic Library A genomic library is a collection of genes or DNA sequences created using molecular cloning. These libraries are constructed using clones of bacteria or yeast that contain vectors into which fragments of partially digested DNA have been inserted. These bacteria and yeast are subsequently grown in culture and when these microorganisms replicate their genome, they also replicate the vector genome contained within them, that is, they replicate DNA fragments that had been inserted in vectors producing clones of the original DNA. This collection of clones, in theory, contains all sequences found in the original source, including the sequence of interest. This sequence of interest is identified using screening methods that are very complex and capable of finding the original clone among 10 million starting clones. Genomic libraries can be constructed using various hosts like plasmids (insert size up to 15 kb), bacteriophage lambdas (insert size up to 20 kb), cosmids (insert size up to 45 kb), YACs and (insert size up to 2,000 kb), and many more. Some important ones are as follows: Constructing Genomic Libraries Using Plasmids: This is the process of cloning human DNA fragments by inserting them between two EcoRI digested sites of a plasmid cloning vector. After the human DNA fragments are inserted into the plasmid, the plasmids in turn are inserted into bacterial cells. In the end, these host bacterial cells contain their own chromosomal DNA together with plasmid DNA. As these bacteria replicate their chromosomes, they also replicate with them the plasmid cloning vectors. Plasmids are very convenient to work with because they contain one origin of replication, one of more selectable markers (such as a gene that confers resistance to antibiotics),
Genotype
and one or more restriction sites that can be cut and used for ligation of foreign DNA molecules. Constructing Genomic Libraries Using Bacteriophage Vectors: The human genome is partially digested with a restriction enzyme like Sau3A in a specific way so that some of the sites are cleaved and others are not. By this way, random cleavage of the sites occurs and a collection of overhanging fragments of length suitable for cloning can be obtained, which are then ligated into bacteriophage lambda “arms” prepared so that the Sau3A ends of human DNA fragments can be ligated into the vector. The recombinant lambda chromosomes are then packaged into the infectious bacteriophage, and then the library, containing 1 million or more fragments of genomic DNA, can be stored for the future isolation of many genes. A collection of several hundred thousand phages would represent the entire DNA from the human genome. Constructing Genomic Libraries with Yeast Artificial Chromosomes (YACs): Large fragments of human DNA (over 500 kb) are generated by partial EcoRI digestion of human genomic DNA. Individual vector arms contain telomeres at one end and EcoRI compatible overhangs on at the other end. Individual vectors also carry a different selectable marker, and one arm also contains a centromere and selectable markers at each end and a yeast chromosome at the other end. The YACs are transferred into yeast, and the selectable markers are used to select only those yeasts that contain a properly constructed YAC. Advantages of Molecular Cloning The main task of modern medical genetics is to understand genetic disease in terms of mutations, and to find highly efficient methods of diagnosis and treatment. Medical geneticists, however, are faced by two difficulties when trying to find the basis of genetic disease. The first difficulty is obtaining enough amount of DNA to work with because cells generally have only two copies of a gene and some genes are only transcribed in specific tissues providing very little RNA to work with. The second difficulty is obtaining a purified form of the specific sequence of interest from all other sequences of DNA and mRNA pres-
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ent in the cell. To solve these two problems, scientists have come up with various techniques, one of them being molecular cloning. Molecular cloning allows us to obtain large sequences of purified DNA that were, otherwise, impossible to obtain. See ALSO: Clone; Genetic Disorders; Genetic Testing/
Counseling; Genetics.
Bibliography. Robert L. Nussbaum, Roderick R. Mc-
Innes, and Huntington F. Willard, Genetics in Medicine, 6th, ed., (Thompson & Thompson, 2001); Susan L. Speaker, Elizabeth Hanson, and M. Susan Lindee, Guide to the Human Genome Project: Technologies, People, and Information (Chemical Heritage Foundation, 2005). Rahul Gladwin, M.D. University of Health Sciences Antigua
Genotype A genotype is the specific genetic constitution or makeup (genome) of an individual in terms of its DNA. The DNA through the genotype determines the hereditary potentials and also the limitations of an individual person (or indeed that of any organism) from its embryonic formation through to adulthood. For organisms that reproduce sexually, the inherited genotype contains the entire complex set of genes from both parents. This means that after sexual reproduction, it is certain that each individual will have a unique genotype, except for identical twins, triplets, and so forth, who are derived from the same fertilized egg. This contrasts with the phenotype of an individual which involves the physical appearance and constitution of an organism. For medical research, the genotype is crucial in working out ways of treating diseases in general, separated from the person suffering from the disorder. This has been particularly important in the treatment of cancer, with oncologists and their research teams anxious to work on the fundamental causes of cancer and try to eliminate hereditary factors that might otherwise influence their work. Much of the original research and the development of ideas on genotypes was carried out by the Danish botanist and geneticist Wilhelm Ludvig
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Johannsen. He conducted many experiments in plant heredity and these tended to support the mutation theory of the Dutch botanist Hugo de Vries, which argues in favor of gradual change through heredity rather than Charles Darwin’s concept of natural selection. Johannsen coined the term genotype, based on genus, and also the term phenotype. Although research in genotypes has aided much medical research, one of the emerging problems with the increased popularity of genotype research has occasionally led to some people, who have no real understanding of medicine, to become fatalistic and feel that particular disorders from which they suffer are part of their inherited genotype and ignoring environmental and other factors. SEE ALSO: Phenotype. Bibliography. Steve E. Humphris and Sue Malcolm,
From Genotype to Phenotype (Bios Scientific Publishers, 1994); Majit S. Kang and Hugh G. Gauch, Jr., Genotype-byEnvironment Interaction (CRC Press, 1996); Amy Suzanne Richards, The Effects of Genotype and Environment on the Chemical Composition and the Influence of Oxidative Stability of Brassica napus and Brassica Juncea Oils, PhD thesis, University of Melbourne, 2006. Justin Corfield Geelong Grammar School, Australia
Georgia This Republic in the Caucasus was a part of the Russian Empire until 1922 when it became a constituent part of the Soviet Union. It became an independent nation in 1991. It has a population of 4,694,000 (2004) and has 436 doctors and 474 nurses per 100,000 people. While Georgia was a part of the Soviet Union, healthcare was extensive and coordinated from Moscow, the capital, which established the basic policies for the whole country, although these were implemented by the health ministries of the constituent republics. There were also regional and local health authorities which provided healthcare. The main problem faced by Georgia was that the Soviet
Union wanted to set national standards of health care, along with quotas for patient visits, and the provision of treatment and hospital beds with not much consideration for the regional differences in the need for healthcare. Georgia also became a place to where many people from elsewhere in the Soviet Union went to for health cures in spa resorts. Many of these were restricted to people who worked in state enterprises throughout the Soviet Union, with access being regarded as a privilege. Traditionally much healthcare was provided in the home, with people being treated by family members, and elderly people remaining at home rather than going to hospitals, as institutional nursing care was often poor. The system, which operated in Tbilisi, the capital of Georgia, and to a lesser extent in the rest of the country, saw emergency first aid provided by ambulance teams that were often well equipped by regional standards, although their equipment lagged considerably to that used in western Europe. As regular hospitals did not have emergency rooms, there were special emergency hospitals which dealt with people treated by ambulance teams. In remote parts of Georgia, the system was often haphazard because of the problems with communications and roads. When the Soviet Union was dissolved, the responsibility for looking after the health services of Georgia fell to the Ministry of Health. At that time, the healthcare of the population of Georgia had been exceedingly good. With Georgia having the highest number of doctors per capita, 59.2 doctors per 100,000 people, it also had more dentists per capita than any of the Soviet republics. Tuberculosis diagnoses, at 28.9 cases per 100,000 people, was the third lowest of any of the republics in the Soviet Union, and cancer, at 140.9 diagnoses per 100,000 people in 1990, was the lowest. However, there were problems with hospital bed availability which was low, and the rate of infant mortality was also high. By this time, the healthcare system had become underfunded, and the decline in living conditions also led to the increased prevalence of some diseases. There were also more frequent problems of ill-health environmental hazards. These include some problems from nuclear waste left over from Soviet-era sites. A Georgian commission inquiry into radiation burns suffered by 11 soldiers in February 1997, concluded in November 1997 that there were 352 contaminated
Geriatrics
sites in the country. By contrast with the plight of the majority of the people in the country, the elite in Georgia continued to experience good healthcare having access to the best medical facilities. Alcoholism and problems relating to it had always been a major factor in Georgia, and from the 1990s, there was a massive increase in drug use, but it remains low by international standards, with alcohol abuse being much more serious. The first cases of the HIV/AIDS were reported in 1993 with the Republic AIDS and Immunodeficiency Center in Tbilisi reporting the detection of sixteen cases, five from foreigners who were then deported. The number of cases has increased during the late 1990s, but is still much lower than many other countries in the world. There is now compulsory medical insurance for everybody, and there have been large increases in the amount of money spent on healthcare from the mid-1990s. The political infighting, and also the civil war and large numbers of refugees have led to more demand on medical facilities. There are three medical associations in Georgia, with the Georgian Bio-Medico-Technical Society and the Georgian Society of Patho-Anatomists both being affiliated to the Georgian Academy of Sciences, and the Georgian Neuroscience Association founded in Tbilisi in 1996. There is also a Research Institute of Oncology in Tbilisi. The main center for medical training in the country remains the Tbilisi State Medical University, which was founded in 1918. It publishes the Georgian Medical News each month and Georgian Medical Research annually. It has 780 teachers and 4,000 students and maintains a library of about 520,000 volumes. Within it are located schools of general medicine, pediatrics, stomatology, health administration and management, pharmacy, medical biology, and nursing. SEE ALSO: AIDS; Alcholism. Bibliography. W. Horsley Gantt, Russian Medicine (P.B.
Hoeber, 1937); Galina Vasilevna Zarechnak, Academy of Medical Sciences of the U.S.S.R.: History and organization 1944–1959 (U.S. Department of Health, Education and Welfare, 1960). Justin Corfield Geelong Grammar School, Australia
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Geriatrics Geriatrics is the medical specialty concerned with elderly people and the field of human aging. Due to the important and worldwide population aging, geriatrics became an important specialty in medical care and in public health planning. Geriatrics deals with the human aging process and its implications, as well as with the prevention, diagnosis, and treatment of health problems in elderly people. During human aging, people undergo transformations that change the likelihood of becoming ill, because the functional reserve of one person—the capacity of functioning of each human organ or system surpassing the needs of everyday life—decays in this process. Importantly, however, in the absence of health challenges (e.g., diseases), human aging does not impose restrictions to everyday life. Since aging is a progressive phenomenon, this likelihood of illness tends to increase with age. As both susceptivity and reaction capacity for diseases change with age, so too do the clinical manifestations of many common diseases. A myocardial infarction may arise without pain in an older person, making the clinical picture very different from what medical doctors might generally expect. Another specificity of geriatrics is the so-called comorbidity; because the effects of bad habits (e.g., bad nutrition, smoking, sedentarism, alcohol and abuse of other substances) tend to accumulate with time and the same is true for chronic diseases, it is common for an elderly person to have different diseases at one time. Comorbidities and bad health habits may increase the decay of functional reserve, making an individual more frail than he or she should be at a given age. This is called pathological aging, the phenomenon responsible for making people’s health status different from each other’s. A geriatrician, therefore, has to be able to give preventive care for anyone concerned with keeping good health, to care for multiple chronic diseases in an elderly person, or even to give palliative care for those dying. That makes geriatrics a very broad field. Some conditions are common in the elderly and they are studied carefully within geriatrics. They include cognition-affecting diseases (notably Alzheimer’s disease), depression and delirium (a mental disorder arising from clinical diseases), urinary symptoms
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and diseases (such as urinary incontinence or prostate diseases), malnutrition, immobility, and falls. While caring for comorbid conditions, geriatrics concentrates on maintaining the functional status of patients, because this is what allows the engagement of daily living activities or prevents a person from doing so rather than the number or importance of the diseases per se. In this sense, rehabilitation (e.g., with physical or occupational therapy) after a loss of health status or adaptations in the environment (e.g., the substitution of a ladder for a slope allowing the passage of wheelchairs) may help a patient recover functional status even when the medical condition responsible for the loss is irreversible. Polypharmacy is another common situation in geriatric care. Having more than one chronic condition, for example, diabetes, hypertension, and high lowdensity lipoprotein (LDL) cholesterol levels, may imply the need for simultaneous treatments, frequently with the use of multiple drugs, increasing the chances of adverse or antagonistic drug effects. The simultaneous use of different drugs may also be a burden in the patient’s metabolism, because the metabolic reserve also diminishes with age. Finally, changes in the metabolism and body composition result in several pharmacological behaviors different of those observed in young adults. A common condition is related to the duration and intensity of a drug effect: lipid-soluble drugs tend to have longer-lasting effects in the elderly and water-soluble drugs tend to have more intense effects due to the fat increasing with aging at the same time that the proportion of water decreases. Because of the particularities of pharmacology in the elderly and the likelihood of comorbid conditions, elderly people are at great risk of iatrogenics, defined as a medical intervention causing loss for the patient or the lack of a medical intervention that would have done good for the person. It is important to stress, nonetheless, that iatrogenics does not always mean a mistake, because the care of the elderly may be so challenging that giving standard care for a frail elderly may be the cause of iatrogenics. Finally, in this complex scenario, there are situations when a calculated iatrogenics may be essential to achieve a necessary result; the use of toxic antibiotics to cure an infection being one case in point. Another important aspect in geriatrics is the need to establish treatment priorities, because caring for one disease may prevent the treatment of another
condition or simply a patient may be so frail that the challenges of multiple drugs may result in worse consequences than carefully neglecting one mild disease. Priorities also must be established during terminal illness and palliative care, when relieving and avoid treatment-induced suffering is often more important than using all medical resources available in the quest for a cure that may not be achievable. Geriatrics also studies the field of death and dying. To die with dignity and with the least suffering, surrounded by loved ones is achievable in most cases, mainly when consensus between the patient, family, caregivers, and the healthcare team is present. Geriatric care professionals seek this while making its knowledge available to those in need of it, respecting the will of the patient, who is the center and aim of care. In cases when the patient has no competence to decide, being unconscious or cognitively impaired, advance directives given in the past by the patient or by a person in care of the patient may inform the healthcare team of the amount of therapeutic maneuvers to perform in a terminal condition, for example. Some countries require that advance directives or the power of attorney for healthcare decisions be given by a document signed by the patient prior to the incapacity. Although geriatrics, as a medical specialty, seeks to provide clinicians with the best training and knowledge to care for the elderly, it recognizes that there is no health-related profession or its specialty capable of giving good care in most complex cases, such as frail elders or those with multiple health-affecting conditions or situations. Such cases demand a broader, multidisciplinary team, ideally composed of different health professionals with background in elderly care. Geriatrics itself is a multidisciplinary field that recognizes the different axes involved in the health of the elderly: not only does medical condition influence health and functioning, but environmental factors, psychological status, social conditions and opportunities, and financial matters all influence the health of an older person as well. Geriatrics is a science that studies such fields as the medical therapy and palliative care for the elderly, but it emphasizes the need for health promotion and disease prevention as the only way to achieve long-lasting good health, a way far cheaper than the use of the most advanced therapeutic solutions.
SEE ALSO: Centenarians; Death and Dying; Pharmacology. Bibliography. W. Jacob-Filho and T. Monaco, eds., “Ag-
ing: Concepts and Misconcepts,” in Diagnóstico e Tratamento (Manole, 2006); C. S. Landefeld, Current Geriatric Diagnosis and Treatment (McGraw-Hill Medical, 2004).
Thiago Monaco, M.D., Ph.D. University of SÃo Paulo Medical School, Brazil
Germany Despite the economic upheaval that Germany has experienced since reunification in 1990, the country ranks as the 24th richest nation in the world, with a per capita income of $30,100. The German economy is the largest in Europe, but growth has continued to slow in recent years. No official poverty rates are reported, but unemployment is high (11.7 percent). Income inequality also exists, and Germany ranks 28.3 percent on the Gini index of inequality. The poorest 10 percent of the population claims only 3.6 percent of resources as com-
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pared to 25.1 percent for the richest 10 percent. Direction of social funding to residents of the East German area has caused a great deal of dissatisfaction among some West Germans, and the rapidly aging population has added additional strain to the budget. However, the overall standard of living remains high, and the United Nations Development Programme’s (UNDP) Human Development Report ranks Germany 21st of 177 countries on overall quality-of-life issues. Health insurance in Germany can be either compulsory or voluntary, and approximately 90 percent of all Germans are covered by the compulsory state health insurance plan. Social security is compulsory, and it covers workers, students, trainees, the elderly, and dependents of various groups. Benefits include medical coverage, long-term care insurance, pensions, unemployment stipends, and worker compensation insurance. Employees below a set wage standard pay half the required contribution, and the other half is picked up by the employer. Individuals who earn higher wages contribute established percentages toward insurance coverage, generally about four percent if they choose to join the program. If they desire, salaried employees may choose a private insurance provider.
The UNDP Human Development Report ranks Germany 21st of 177 countries on overall quality-of-life issues. Germany has the second largest population in Europe (82,422,299), and people there enjoy a life expectancy of 78.8 years.
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The government expends a good deal of money on healthcare in Germany, averaging 19 percent of the total budget. Just over 11 percent of the Gross Domestic Product (GDP) is used to fund healthcare, and $3,100 (international dollars) is allotted per capita. Most health spending in Germany originates with the government (78.2 percent), and social security spending accounts for 87.4 percent of all government health costs. The private sector is responsible for generating 21.8 percent of health expenditures, and nearly half (47.9 percent) of that amount involves out-of-pocket expenses. There are 3.37 physicians, 9.72 nurses, 0.10 midwives, 0.78 dentists, and 0.58 pharmacists per 1,000/ population in Germany. In March 2006, the German healthcare system experienced a medical crisis when physicians at all university clinics decided to strike over administrative demands that they work additional hours without a pay increase. After three months of negotiations, employers agreed to increase pay from eight to 18 percent and guaranteed bonuses to specialists who took on additional duties. Germany has the second largest population in Europe (82,422,299), and the people enjoy a life expectancy of 78.8 years. Females outlive males an average of six years. Access to safe drinking water and improved sanitation is universal. The population is highly literate (99 percent), and virtually all children are enrolled in primary and secondary schools. Germany has the 25th lowest fertility rate among the nations of the world. Three-fourths of German women use some form of birth control, and births occur at a rate of 1.39 children per female. All births are attended by trained personnel, and the adjusted maternal mortality rate for German women is eight deaths per 100,000 live births. Women’s health is a major concern, and programs have been initiated to target such areas as breast cancer screening, reproductive health, drug addiction, and domestic violence. While East Germans have equal access to healthcare, some problems of assimilation continue to exist. At the time of reunification, major health indicators in the east were generally lower than those in the west. After reunification, East Germany’s health system was abandoned in favor of the West German system. Over time, differences began to narrow but did not disappear. Life expectancy, for instance, remains lower in the east than in the west. Incidences of alcoholism and obesity have increased, posing greater health threats to East Germans than to West Germans.
At 4.12 deaths per 1,000 live births, Germany has the 11th lowest infant mortality rate in the world. Between 1990 and 2004, the infant mortality fell from seven to four deaths per 1,000 live births, and the mortality rate for children under the age of 5 dropped from nine to five deaths per 1,000 live births. Seven percent of all infants are underweight at birth. Most German infants receive the necessary vaccinations, and diphtheria, pertussis, and tetanus (DPT1) is reported at a rate of 98 percent. The number of infants receiving DPT3 is one percent lower than the rate for DPT1. Immunization rates fall still lower for other vaccinations: polio (94 percent), measles (92 percent), Haemophilus influenzae type B (90 percent), and hepatitis B (81 percent). Air pollution resulting from coal-burning facilities poses a health threat in urban areas of Germany, and the proper disposal of hazardous waste is a national issue. The HIV/AIDS virus has also caused concern because Germany has a 0.1 percent adult prevalence rate. Around 43,000 people are living with the disease, which has proved fatal to some 1,000 people. Germany has also had problems with a number of communicable diseases in recent years, including some that were imported from developing countries. Lassa fever, for example, was imported into Germany in 2000 and 2006. That same year, incidences of meningococcal disease were reported. In 2003, Germany was involved in an outbreak of severe acute respiratory syndrome (SARS), and influenza appeared in January 2004. About one-half of all deaths in Germany are a result of circulatory diseases. Cancer is another leading cause of death, partly because about a third of the population smokes. The government is particularly concerned about rising rates of smoking among women and young people. Consequently, in December 2006, the German government retreated from its traditional position on smoking and announced that it was following the lead of other European nations that had already placed limitations on smoking in restaurants, discos, schools, and some public buildings. Germany, unlike Britain, France, Ireland, and Italy, chose not to restrict smoking in pubs and bars. See Also: European Association for Cancer Research
(EACR); Healthcare, Europe.
Bibliography. Central Intelligence Agency, “Germa-
ny,” World Factbook, www.cia.gov/cia/; Jochen Clasen,
Germline Mutation
Reforming European Welfare States: Germany and the United Kingdom (Oxford, 2005); Commission on the Status of Women, Germany,” www.un.org/womenwatch/; Spencer Di Scala, Twentieth Century Europe: Politics, Society, Culture (McGraw-Hill, 2004); Sandra Halperin, War and Social Change in Modern Europe: The Great Transformation Revisited (Cambridge University Press, 2004); Wade Jacoby, Imitation and Politics: Redesigning Modern Germany (Cornell University Press, 2000); Mark Landler, “Germany to Restrict Smoking, Joining Other Nations in Europe,” New York Times, (December 3, 2006); Martin A. Levin and Martin Shapiro, eds., Transatlantic Policymaking in an Age of Austerity: Diversity and Drift (Georgetown University Press, 2004); Jeremy Rifkin, The European Dream: How Europe’s Vision of the Future Is Quietly Eclipsing the American Dream (Jeremy P. Tarcher/ Penguin, 2004). Elizabeth R. Purdy, Ph.D. Independent Scholar
Germline Mutation Germline mutation is an alteration of genetic matter which occurs after the time of conception and affects germ cells (eggs and sperm). A principal consequence of affecting germ cells is that such mutations may be passed to offspring. Another key consideration is that a germline mutation will likely have few, if any, consequences for the individual with the mutation. Instead, the consequences accrue the offspring. Mutations of this sort are critical in understanding Alfred G. Knudson’s two-hit hypothesis of heritable cancers as well as the spontaneous appearance of phenotypes associated with dominant inheritance in otherwise normal families. Retinoblastoma is the paradigmatic model of the role of germline mutations in cancer caused by the loss of tumor-supressor function. Retinoblastoma appears in two forms: heritable and sporadic, with heritable cancers accounting for 40 percent of the disease. In this form, a child inherits one wildtype allele and one mutant allele at the retinoblastoma locus. This first mutation is Knudson’s first hit. Cells
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heterozygous at the retinoblastoma locus show a normal phenotype until a somatic mutation occurs at the wildtype retinoblastoma locus (Knudson’s second hit). Because this mutation eliminates the only remaining DNA sequence to code for the working tumor suppressor, the resulting cell is without this tumor suppressor’s capabilities and is likely to accumulate other somatic mutations at an increased rate and progress to a tumor. In contrast, the 60 percent of sporadic cancers of this type require two somatic mutations of the retinoblastoma gene, an unlikely event in an otherwise normal cell. Because of these two different mechanisms of tumorigenesis, cancers of this type present differently in the heritable and sporadic modes. Because the underlying somatic mutation in the heritable form is much more likely, heritable cancers of this type occur simultaneously in multiple locations from multiple progenitor cells. Even if all such tumors are excised and the cancer goes into remission, relapse is likely throughout life. In contrast, sporadic cancers of this type occur singly, from a single progenitor cell and are unlikely to recur if cured. There are two ways a dominant mutation can affect a child born to two parents who do not carry the mutation: somatic mutation early in embryogenesis giving rise to a mosaic dominated by the mutant phenotype or germline mutation in one of the parents. The former is exceedingly rare. However, for certain conditions such as osteogenesis imperfecta, certain hemophilias and Duchene’s muscular dystrophy, germline mutation may increase the risk of recurrence by several orders of magnitude (to as high as 15 percent). Consideration of the role of mosaicism in atypical inheritance is now considered standard practice in genetic testing and counseling. SEE ALSO: Cancer (General); Osteogenesis Imperfecta;
Somatic Mutation.
Bibliography. Justin C. St. John and Gerald P. Schatten,
eds., Mitochondrion in the Germline and Early Development (Elsevier Science & Technology Books, 2007); R.L. Nussbaum, et al., Thompson & Thompson: Genetics in Medicine, 6th ed., revised reprint (Saunders, 2004). Bimal P. Chaudhari Boston University
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Gerontology Gerontology is the interdisciplinary study of aging and all that it encompasses, and gerontological studies have become increasingly significant as life expectancy expands around the globe. The word gerontology is derived from the Greek and literally means “old man.” The term was coined by Nobel Prize-winning Russian immunologist Elie Metchnikoff (1845–1916) who worked at the world-renowned Pasteur Institute. In The Nature of Man (1903) and The Prolongation of Life: Optimistic Studies (1907), Metchnikoff argued that creativity was essential to longevity. He believed that aging was a process of cellular involution in which deteriorating cells countermanded cell growth of earlier life stages. This process could be halted, he believed, by the promotion of intestinal health. Geriatrics, which is related to gerontology, is concerned with the physical aspects of aging. The term was coined by Austrian American physician Ignatz Nascher (1863–1944) in 1908. The field of gerontology was greatly advanced in 1992 with the publication of Senescence: The Last Half of Life by G. Stanley Hall (1844–1924), a pioneer in the fields of both psychology and education. Hall contended that aging should not signal an end to creativity and vitality. In 1939, professional handbooks become the major source of information for gerontologists, particularly in the United States, with the publication of American physician Edmund V. Cowdry’s (18881975) Problems of Aging. After World War II, the study of gerontology further expanded as researchers began applying social science to the study of aging. In 1944, the American Social Science Research Council established a committee on aging, leading to Otto Pollack’s (1887–1972) landmark publication of Social Adjustment in Old Age in 1948. The Gerontological Society was founded in 1945 and began publishing the Journal of Gerontology the following year. In 1953, Robert J. Havighurst (1900–91) and Ruth Albrecht (1910-?) published Older People in which they took other gerontologists to task for not addressing the lack of social equality for the elderly by examining such areas as housing, healthcare, and social security. Some four decades later, Betty Friedan (1921–2006), the mother of the Second Wave of the women’s movement, continued to fault gerontologists for their part in making the elderly invisible, accus-
ing them of dismissing the possibility that the elderly could continue to grow and change as they aged. Applications of gerontology Duke University conducted one of the first longitudinal (1955–80) studies that examined the impact of gender, ethnicity, and social status on aging. Two decades later, the Midtown Manhattan longitudinal Study and a National Center for Health Statistics study painted a discouraging picture of aging women. The report maintained that beginning in their 20s, women progressively deteriorated, with the most significant impairment occurring after the age of 40. In response to the women’s movement, researchers began paying greater attention to women’s physical and psychological health. Consequently, later studies indicated that women’s health had significantly improved, while little change had occurred in men’ health. In 2007, American women had a life expectancy at birth of 80.97 years. Following a global trend, life expectancy for males was lower at 75.15 years. In most of the world, individuals are living longer in response to improved healthcare and technology, healthier lifestyles, and widespread access to safe food, clean water, and improved sanitation. All developed nations are currently faced with an aging population that demands a significant portion of available resources. In 2007, 12.6 percent of the American population was over the age of 65. By 2030, estimates place that number at a fifth of the population in response to the aging of baby boomers. One-fourth of those aged Americans will be people of color. At the international level, it is estimated that the world’s population of those over the age of 60 will reach the two billion mark by 2030. In the United States, as in the rest of the world, the quality of life for the aged is heavily dependent on economic status and access to healthcare. Because of unequal wages, women and African Americans are more financially vulnerable that white males. Social Security, which provides 44 percent of income for elderly Americans, accounts for 88 percent of income for elderly African Americans. White males are more likely than other elders to have employment pensions and private retirement accounts, resulting in unequal distributions of elderly income. In 2004, for instance, the Social Security median income for American males over 65 was $12,583, but only $8,799
for women. When other sources were factored in, the median income for males increased to $20, 800 and to $12,000 for females. Without government aid through such programs as Social Security, Medicare, and Medicaid, elderly Americans would be even more vulnerable. This fact is evidenced by the decline in the poverty level for individuals over the age of 65, which dropped from 24.6 in 1970 to 9.8 in 2004. Despite the fact that the United States spends more on elderly healthcare than other developed nations, the care of aging Americans is considered poor when compared to those nations with government-sponsored programs that provide financial assistance to the elderly without requiring them to “poor themselves down” in order to qualify for residential long-term care. As a result of gaps in American healthcare coverage, two-thirds of elderly Americans are forced to purchase private insurance to supplement Medicare benefits. By the 1980s, gerontologists were focusing on societal and political solutions to the problems of aging and promoting what they called the “new longevity.” By the end of the century, the trend had shifted from relegating the aged to nursing homes to allowing the more affluent elderly to continue living as normally as possible in their own homes or in retirement communities. Since memory function declines as individuals age, gerontologists supported the use of physical and mental exercise to stimulate brain activity; and senior citizen centers offered a variety of programs to aid in continued growth and development. Providing solutions to aging has become a billion dollar market in much of the developed world, offering everything from cosmetics to drugs to surgery to halt or offset the aging process. Some gerontologists have criticized the overuse of such methods. On the other hand, the use of nutritional supplements in fighting disease has been readily embraced by both mainstream gerontologists and practitioners of alternative medicine. Studies have indicated that elderly individuals who experience vitamin B-7 and B-12 deficiencies may exhibit signs of dementia. Vitamin D is believed to aid in preventing bone fractures, while calcium is promoted as having the capability to enhance nerve function, promote blood clotting and muscle contraction, and provide some defense against colon cancer. Vitamin E is considered to protect against all cancers. Some gerontologists suggest that products
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such as those containing caffeine and sugar may have greater negative impacts on the aged. By the latter half of the 20th century, the global population of individuals over the age of 60 had nearly trebled. Global life expectancy increased from 46 years in 1950 to 66 years in 2000. Life expectancy in developing nations has increased by approximately 50 percent as fertility rates have decreased. Consequently, the aged make up larger proportions of populations. In response, the United Nations World Assemblies held two international conferences on aging. The first, held in Vienna in 1992, focused on aging in developed nations. The second conference in Madrid in 2002 examined aging in the developing world, which is home to more than one-half of the global population over the age of 60. By 2050, it is estimated that 85 percent of the aged will live in developing nations, with the largest gains taking place China, Brazil, Nigeria, Indonesia, Colombia, Kenya, and Thailand. Among developed nations, the largest gains are expected to occur in Japan, Switzerland, Italy, and Germany. The only nations that are not expected to mirror this trend to some degree are those in sub-Sahara Africa where poverty and HIV/AIDS continue to exact a heavy toll on life expectancy. In 2002, the International Association of Gerontology sponsored the Valencia Forum, joining with the United Nations Office on Aging to develop a research agenda for the world’s aging population. A number of variables such as sex, genetics, lifestyles, economic status, and access to healthcare, housing, and the environment are now regularly examined to develop gerontological theories and solutions to the problems of aging. See Also: Administration on Aging; Alzheimer’s Disease;
Geriatrics; Medicaid; Medicare; Women’s Health.
Bibliography. M. Clemmitt, “Caring for the Elderly,” CQ
Researcher (v.16, 2006); Margaret Cruikshank, Learning to Be Old: Gender, Culture, and Aging (Rowman & Littlefield, 2003); Betty Friedan, The Fountain of Age (Simon & Schuster, 1993); Robert J. Havighurst, and Ruth Albrecht, Older People (Arno, 1953); Malcolm L. Johnson, ed., The Cambridge Handbook of Aging (Cambridge University Press, 2005); Stephen Katz, Aging: Life Course, Life Style, and Senior Worlds (Broadview, 2005); Donald H. Kausler, et al., The Essential Guide to Aging in the Twenty-First Century:
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Mind, Body, and Behavior (University of Missouri Press, 2007); The Merck Manual of Geriatrics (Merck Research Laboratories, 2000); Debra J. Sheets, et al., eds., Enduring Questions in Gerontology (Springer, 2006). Elizabeth R. Purdy, Ph.D. Independent Scholar
Ghana Ghana is located in western Africa on the Gulf of Guinea, between Togo and Côte d’Ivoire. Formerly a British crown colony called the Gold Coast, in 1957, Ghana became the first sub-Saharan nation to emerge from colonial rule. Now 50 years old, Ghana has suffered through a long string of political coups and the creation of a new constitution. Its economy, while better than its neighbors, is still heavily dependent on international aid, and about 60 percent of the workforce relies on subsistence agriculture. The population is 22,931,000, growing at 1.972 percent annually. The birth rate is 29.85 per 1,000 population and the death rate is 9.55 per 1,000. Median age is 20.2 years. Life expectancy is 58.31 years for males and 59.95 years for females. Forty-eight percent of Ghanians live in urban areas. The gross national income is $450 a year, with 45 percent of the population living on $1 a day or less. With only 75 percent of the population able to access safe drinking water and 18 percent with sanitary waste facilities, Ghana suffers from a high rate of waterborne and parasitic infections, including diarrhea, typhoid fever, Guinea worm disease, and schistosomiasis. Malaria and tuberculosis remain the biggest threat to Ghanian health. Recent years have seen a decline in malaria deaths, but it is still among the biggest killer of children under 5, and only three percent of Ghanians sleep under insecticide-treated nets. Tuberculosis (TB) cases have increased dramatically over the span of a decade. In 1995, there were 2,195 TB cases within the country. Today, there are 30,000 new cases a year, and 15,000 fatalities. Many cases are found to be multidrug resistant. As in most country, the rise in TB cases has mirrored a rise in HIV/AIDS infections. The adult
prevalence rate is 2.3 percent, with an estimated 320,000 cases, including 180,000 women. Ghana has a strong strategic plan and has secured international funding for programs, but the Ministry of Health notes that most patients have trouble affording even subsidized drugs. Only seven percent of patients are on antiretroviral therapy; 1.3 percent of pregnant women receive treatment to prevent mother-to-child tranmission. The Ministry of Health says that the noncommunicable disease burden of Ghanians are “largely unknown.” A major hospital found that hypertension was the third leading cause of mortality in their facility, after malaria and diarrhea. Antitobacco programs and diabetes awareness campaigns have met with limited success. Most medical facilities are poorly equipped to handle noncommunicable illnesses. One in nine Ghanian children die before their fifth birthday. Malaria is the leading cause, although it has declined over the past five years. Immunization rates have increased, and are most apparent in the substantial reduction in measles cases, from 13,500 in 2001 down to just 487 in 2005. Malnutrition rates are “unacceptably high” according to the Ministry of Health. Fifty-seven percent of children work, and 28 percent marry before the age of 18. The total fertility rate is 3.89 children per women. A quarter of Ghanian women use contraceptives. Less than half have a trained attendant to assist during childbirth. The maternal mortality rate is thus high, estimated at 540 deaths per 100,000 live births. Medical services in Ghana are clustered along the coast, with limited services in the northern tier of the country. At least 40 percent of medical care comes from faith-based non-governmental organizations. Ghana suffers from a “brain drain” of trained staff: a 2002 report found that 30 percent of the physicians and nurses educated within the country between 1993–2002 left the country for better opportunities abroad. See Also: Healthcare, Africa; Malaria; Tuberculosis. Bibliography. “Ghana” CIA World Factbook, www.
cia.gov/library/publications/the-world-factbook/geos/ gh.html (cited June 2007); UNAIDS: The Joint United Nations Programme on HIV/AIDS, “Ghana,” www.unaids.org (cited June 2007); Ministry of Health, Republic of Ghana
Giardia Infections
“Pause, Get It Right, Move On: Review of Ghana Health Sector 2005 Programme of Work”. Ministry of Health, Republic of Ghana. www.moh-ghana.org/moh/docs/Report2005.pdf (accessed June 2007); “UNICEF—At a glance: Ghana—Statistics”. UNICEF. www.unicef.org/infobycountry (accessed June 2007). Heather K. Michon Independent Scholar
Giardia Infections Despite the controversy about the taxonomy of the species in the genus Giardia, this protozoan (G. intestinalis/lamblia/duodenalis) produces an important disease in the proximal portion of the small intestine, which could be asymptomatic, produce an acute self-limited diarrhea, and diverse intestinal symptoms such as chronic diarrhea, abdominal pain, cramps and tenderness, and weight loss, among others. Normally, there is no extraintestinal infections, but sometimes could produce a reactive arthritis (in recent years different studies revealed a clear relationship between giardiasis and inflammatory processes and allergy, possibly because infection by this protozoon enhances sensitization toward food antigens, due to increased antigen penetration through damaged intestinal mucosa). In severe Giardia infections, significant lesions of duodenal and jejunal mucose cells also are seen. Although many aspects of the infection are currently known, the mechanisms of pathogenicity and the major host defenses against Giardia infection are not well characterized. This infection could lead to intestinal malabsorption that may be severe, and when it occurs in children, it could be associated with growth and development retardation. This pathogen has a considerable prevalence either in institutional and community settings. This parasite, described in 1859 by Lambl, is a flagellated eukaryote organism (which belongs to the subphylum Mastigophora) with a relatively simple life cycle which includes trophozoites (vegetative stage) and cysts (infective stage). Humans can carry both forms, as can animals, and today, giardiasis is considered a zoonosis.
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Diagnosis of Giardia infections is made by examining stools of suspected individuals or animals (including direct and stained observations as well as cultures of the organism); however, sometimes this is not enough and other diagnostic techniques should be used (immunological and molecular tests), even to the extent of studying the duodenal contents. Giardia can also be diagnosed when organisms are seen in intestinal biopsy specimens and/or at endoscopic evaluations. The choice treatment for this infection is tinidazole or nitazoxanide. Alternative treatments may include metronidazole and paromomycin. In refractory patients, metronidazole and quinacrine may be used. As with most infectious and parasitic diseases, prevention is the most important issue. In the case of giardiasis, safe water access is one of the primary priorities that should be considered, because cysts could be viable for a long time in water contaminated by human and animal feces. Additionally, as giardiasis is common in children, health education, especially in primary schools, is useful in preventing this infection. Recently, the importance of this pathogen for travelers to zones with high prevalence of this parasitosis has been highlighted. Finally, molecular tools that are now available will be useful in better understanding the frequency of zoonotic transmission as well as in developing more effective approaches to controlling giardiasis. SEE ALSO: Gastroenterology; Infectious Diseases (Gen-
eral); Immunology; Parasitic Diseases; Pathology.
Bibliography. Antonio Atias, Medical Parasitology
(Mediterraneo, 2005); Paul Beaver, Rodney Jung, and Eddie Cupp, Clinical Parasitology (Lea & Febiger, 1984); Gordon Cook and Alimuddin Zulma, Manson’s Tropical Diseases (Saunders, 2003); Becerri Flores and Romero Cabello, Medical Parasitology (McGraw-Hill, 2004); David Heymann, Control of Communicable Diseases in Man (APHA/PAHO/WHO, 2004); Pan American Health Organization, Zoonoses and Communicable Diseases Common to Man and Animals: Parasitoses (Pan American Health Organization, 2003). Alfonso J. Rodriguez-Morales, M.D., M.Sc. Universidad de Los Andes, Venezuela Carlos Franco-Paredes, M.D., M.P.H. Emory University
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Gibbon, John H., Jr.
Gibbon, John H., Jr. (1903–73) John H. Gibbon, Jr., was an American cardiovascular surgeon who successfully developed the first artificial machine to bypass the patient’s heart and lungs during an operation. With his invention, Gibbon paved the way for modern open-heart surgery. Gibbon was born in Philadelphia on September 29, 1903, into a family of medical doctors from four generations. He received his A.B. from Princeton University in 1923 and his M.D. from Jefferson Medical College of Philadelphia in 1927. He completed his internship at Pennsylvania Hospital in 1929. He then obtained a research fellowship at Harvard in the early 1930s and later became a Harrison Fellow of Surgical Research at the University of Pennsylvania. It was during these years that Gibbon worked to develop an artificial mechanism that could take over the functions of the human heart and lungs during an operation. He was convinced that such a machine would allow better heart surgery techniques. His initial experiments in the field were met with skepticism by the medical establishment, but Gibbon continued his research independently. He first experimented on animals, keeping a cat alive for almost half an hour in 1935. During World War II, Gibbon suspended his experiments to serve in the China-Burma-India theater. After the war, Gibbon joined the faculty of Jefferson Medical College and became director of the Department of Surgery in 1946, a position he maintained until 1967. While at Jefferson, he resumed his experiments on animals, beginning a new series on dogs in the early 1950s. On May 6, 1953, Gibbon first used his heart-lung machine in an operation on a human being. The 18year-old Cecilia Bavolek underwent an operation for the repair of an atrial septal defect and was completely supported for 26 minutes by the machine. The development of the heart-lung machine catapulted Gibbon to international fame. Thanks to successive modifications and improvements, the machine can now be used for open-heart surgery and for heart transplant. While the name of Gibbon has become synonymous with the device he invented, he was also the editor of ���� the Annals of Surgery and author of Surgery of the Chest. He received honorary degrees from the Universities of Princeton, Buffalo, and Pennsylvania, and
Dickinson College. For his invention, Gibbon received awards from the Gairdner Foundation, the International Society of Surgery, the Pennsylvania Medical Society, and the American Heart Association. Gibbon retired from Jefferson Medical College in 1967 and died on February 5, 1973. SEE ALSO: Heart Bypass Surgery; Heart Diseases. Bibliography. Harris B. Shumacker, Jr., Dream of the
Heart: The Life of John H. Gibbon, Jr. M.D.: Father of the Heart-Lung Machine (Daniel & Daniel, 1999); “Biographical Note,” Web site of the United States National Library of Medicine, www.nlm.nih.gov/hmd/manuscripts/ead/ gibbon.html (cited July 2007). Luca Prono Independent Scholar
Glaucoma Glaucoma is a disease characterized by elevated intraocular pressure, optic nerve damage, and subsequent impaired vision. Glaucoma is one of the leading causes of adult blindness in the United States and worldwide. Risk factors include increased age, African-American race, and family history in a first-degree relative. The main types of glaucoma include primary open angle glaucoma, angle closure glaucoma, and congenital glaucoma. Primary open angle glaucoma is the most common form of glaucoma and occurs in 0.5 to 2.1 percent of the population over the age of 40. It is caused by a resistance to flow of aqueous humor. Aqueous ����������� humor is produced in the ciliary body and drained by the trabecular meshwork. Dysfunction of the trabecular meshwork leads to a disruption in the normal flow of aqueous humor. This results in an increase in the pressure of the eye and damage to the optic nerve. The increased pressure causes a decrease in the blood supply to the nerve and thus damage to the nerve. Over time, due to the damage to the nerve, patients will gradually lose peripheral vision. In advanced cases, the vision loss can lead to absolute blindness. Angle closure glaucoma results from the peripheral iris, or colored part of the eye, blocking the trabecular meshwork. The angle closure leads to a rise of the in-
Glaucoma
Glaucoma is one of the leading causes of adult blindness in the United States and worldwide.
traocular pressure from its normal level (10 to 21 mm Hg) to 30 mm Hg or more. This results in an increase in aqueous fluid inside the eye causing damage to the optic nerve. Prodromal symptoms occur as transitory attacks during which time patients may experience symptoms of decreased vision, eye pain, halos around lights, headache, nausea, and vomiting. Another important type of glaucoma is congenital or infantile glaucoma. Congenital glaucoma has an incidence of 1 in 10,000 births with an increased incidence in males. The exact cause is unknown but appears related to a maldevelopment of the aqueous humor drainage system. Signs and symptoms include enlarged cornea (buphthalmos), photophobia, and tearing. Prompt surgical intervention offers the best method of controlling the intraocular pressure and long-term preservation of vision. For the adult patient, the first signs of glaucoma include gradual loss of peripheral vision. Patients with angle closure glaucoma may present with pain and colored halos, but with primary open-angle glaucoma, patients may be asymptomatic until late in the disease. Glaucoma screening involves a complete ophthalmic history and examination, including evaluation of intraocular pressures, optic nerve, visual fields, and gonioscopy (evaluation of the drainage system of the eye). Intraocular pressure in most individuals ranges between 10 and 21 mmHg, with an average of approximately 16 mmHg. Patients with pressures above 21 are suspicious for glaucoma. Intraocular pressures
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can fluctuate throughout the day, so pressure levels cannot be the only screening tool for glaucoma. During examination, the optic nerve is also observed. The optic nerve is examined by comparing the cup to disk ratio. A central depression exists in the optic nerve called the cup. An increase in the size of the cup relative to the rest of the nerve signifies glaucomatous damage. Physical examination should also include gonioscopy. Gonioscopy consists of a special lens placed on the eye that allows visualization of the trabecular meshwork, peripheral iris, cornea, and presence of angle closure. For patients with glaucoma, management includes intraocular pressure checks every three to six months, visual field examination every six to 12 months, gonioscopy and optic nerve evaluation yearly. Treatment for glaucoma includes the use of medications, laser, and surgery. Although glaucoma cannot be completely attributed to increased intraocular pressure, most therapy is directed toward decreasing the pressure. Decreasing the pressure in the eye can decrease the risk of visual impairment dramatically. Medications include several types of eye drops directed at decreasing pressure. Several of the medications have mechanisms of action similar to medications taken for other systemic conditions. Patients with glaucoma should inform their ophthalmologist about other medications they are taking. Laser therapy involves laser treatment of the trabecular meshwork. It is thought that a cascade of biological events that involves renewal of trabecular meshwork cells and accelerated turnover of the extracellular matrix, or tissues between the trabecular cells, enhances outflow through the trabecular meshwork following laser treatment. With angle closure glaucoma, laser therapy creates an opening in the iris, allowing for another route of aqueous fluid to be removed from the eye. Surgical treatment consists of a trabeculectomy or tube shunt placement that allows an alternate route of filtration of excess aqueous fluid out of the eye. Through the methods of medications, laser treatment, and surgery, intraocular pressure is reduced and optic nerve damage is offset. Appropriate and early diagnosis and treatment can prevent significant loss of vision in glaucoma patients. Continued efforts to improve early screening and prompt treatment for glaucoma patients are underway. SEE ALSO: Eye Care; Eye Diseases (General); Ophthal-
mologist.
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Global Health Council
Bibliography. G. Cioffi, and E. Van Buskirk, “Glau-
coma Basics & Frequently Asked Questions,” American Glaucoma Society, www.glaucomaweb.org (cited October 2006); Peter Kaiser, Neil Friedman, and Roberto Pineda. The Massachusetts Eye and Ear Infirmary Illustrated Manual of Ophthalmology (Saunders, 2004); Jack J Kanski, Clinical Ophthalmology (Butterworth-Heinemann, 2000); Derek Y. Kunimoto, Kunal D. Kanitkar and Mary S. Makar. The Wills Eye Manual (Lippincott Williams & Wilkins, 2004). Komal Bharat Desai, M.D. Jacquelyn Sturm, M.S. Independent Scholars
Global Health Council The Global Health Council (GHC) was established in 1972 as the National Council of International Health. This established Council is a U.S.-based, nonprofit membership organization that is dedicated to saving lives and improving the health of people worldwide by working collaboratively to identify world health problems and reporting them to the international and domestic communities. GHC membership is extensive and includes government agencies, international healthcare professionals and organizations, nongovernmental organizations, corporations, and academic institutions. The mission of the GHC is “to ensure that all that who strive for improvement and equity in global health have the information and resources they need to succeed.” In line with the Council’s mission, the organization strives to serve as a voice to inform and educate those who wish to improve global health. Key Issues The GHC has identified the following five key issues that are critical to improving global health: • Women’s health • Child health • Human immunodeficiency virus (HIV)/AIDS • Infectious diseases • Emerging threats The GHC asserts that addressing all of the issues and key points involves coordinated global efforts to help eliminate the barriers to good health. The efforts
necessary to effect change and to address the barriers are complicated and require many resources. The GHC seeks to make multifaceted approaches to fostering change easier by encouraging partnerships among key organizations/peoples. The GHC acknowledges that the common barriers to good global health include poverty, limited education, limited access to healthcare and family planning, limited employment, limited maternal and reproductive health, and violence (gender based and war). The GHC also works to identify potential emerging public health threats. What the GHC Does The GHC works to ensure that all those who want to assist in achieving better global health have the resources to reach this goal. The Council’s membership ensures that it can inform and educate all peoples/ organizations who want to work toward improving global health, as well as educating key leaders, policy makers, the media, and concerned citizens. The GHC also works to encourage investment in the betterment of global health and development of effective methods to improving health. The Council furthers its mission by mobilizing grassroots efforts (such as the International AIDS Candlelight Memorial and Take Action); advocating for increased resources and policy changes to achieve better health; generating media focused on the key issues; disseminating information (through publications including HealthLink, AIDSLink, and technical reports); conducting an annual conference to share knowledge and discuss the key issues; and working to identify evidence-based recommendations through their research and analysis department. Departments The GHC consists of the following departments: • Research and analysis • Government relations • Policy analysis and communications • Public outreach • Administration These departments work together to push forward the GHC mission statement. The GHC offers technical support in the form of training courses, consultation services, and networking. Additional publications include monthly newsletters, monthly job newsletters, and other reports that focus on the identified key ar-
Global Health Ethics
The Global Health Council is a U.S.-based, nonprofit membership organization that is dedicated to saving lives.
eas. The GHC seeks to develop a sustainable future which includes better global health and believes that illness has wide implications that affect all peoples. SEE ALSO: Disease Prevention; International Center for
Equal Healthcare Access; International Council of AIDS Service Organizations.
Bibliography. Global Health Council, www.global-
health.org/; Jay A. Levy, Claude Jasmin, and Gabriel Bez, eds., Cancer, Aids and Quality of Life: Proceedings of the Second International Conference of the International Council for Global Health Progress (Kluwer Academic Publishers, 1997). Sudha Raminani, M.S. The Fenway Institute
Global Health Ethics The Institute of Medicine refers to global health as “health problems, issues, and concerns that transcend national boundaries, may be influenced by circumstances or experiences in other countries, and are best addressed by cooperative actions and solutions.” The notion of global health presumes a common bond between all of humanity, a common fate, and to some
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extent, a common interest in preventing death and alleviating suffering. For many, this common interest defines the ethics of global health; for others, global health ethics is a more complex and varied field. The domain of global health ethics involves both philosophically justifying common interests and deciding how to expend resources to best achieve them. Even though there are clear values inherent in the concept of global health, there is no one ethical framework that guides the field of global health, just as there is no one strict definition of what global health really is. Some of the most difficult questions in global health include the following: 1.What do we, as individuals or as countries, owe to each other in terms of medical aid? 2. How do we apportion scarce resources locally, nationally, and globally? How is it possible that some people have access to tertiary intensive care while others die from affordable vaccine-preventable diseases? 3. Do we have more of an obligation to prevent disease or to treat it? Must we focus on preventing human immunodeficiency virus (HIV) transmission or devote resources to treating those already infected? 4. What principles should be used in responding to global health threats such as pandemic influenza and bioterrorism? 5. How much should cultural preferences determine priorities? Are there moral absolutes in healthcare resource allocation? 6. Should we focus on ensuring equity and equality over maximizing potentially unequal health outcomes? Ethics can refer both to the systematic study of moral concepts and theories, or to a set of rules, principles, values, and ideals that guide a discipline or group of people. The study of ethics is generally divided into the areas of meta-ethics, normative ethics, and applied ethics. Meta-ethics refers to the study of foundational issues such as the nature and sources for ethical principles. The two broad schools of thought in meta-ethics are relativism which understands ethical values as a subjective creation of societies and cultures, and realism which posits that a moral truth based on natural law or divine inspiration objectively exists. Normative ethical theories are approaches to determining what one ought to do—the rightness or wrongness of principles, beliefs, or actions. Theories of normative ethics generally fall into three groups.
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Glomerular Diseases
Virtue ethics focuses on the ethical “actor” or “agent” and deals with qualities or virtues that are desirable. Aristotelian virtue ethics are the prototype of this way of thinking. Deontological ethics, pioneered by Immanuel Kant, emphasize moral duties as the most important element in judging ethical behavior. This approach focuses on certain moral principles that must guide actions, regardless of their consequences. For example, a strict follower of this view might say that it is immoral to lie even if it saves a human life. Teleological or consequence-based theories emphasize outcomes or ends, rather than duties or means. Consequentialist arguments are those most often used in public health and may seem straightforward, but they must resolve the complex task of specifying which outcomes are morally relevant and how they can be maximized. Applied ethics seeks to develop and apply ethical theory to real practical dilemmas. Medical ethics, research ethics, and public health ethics are all areas of applied ethics that may be relevant to problems of global health. Medical ethics usually refers to the ethical principles governing the relationship between healthcare professionals and patients. While medical ethics may extend beyond this narrow definition, it is this small area of medical ethics that has been most extensively studied and taught. Research ethics also received a great deal of attention in the decades following the horrors of Nazi experimentation on human subjects. As a result, there is an extensive, multifaceted regulatory framework that governs medical experimentation and protects research subjects. Public health ethics is a relatively new field that seeks to understand how to apply ethical principles to broader health issues, and balance the needs of individuals and communities. Public health ethics focus more on health promotion and disease prevention in populations than on clinical healthcare in individuals. Frameworks for public health ethics are derived from ethical theory but borrow from the related fields of political and legal theory for justification or implementation. Because promoting global health is necessarily a multidisciplinary and complex endeavor, many ethical paradigms may apply. The approach of public health ethics is probably the most relevant and appropriate to use in addressing global health dilemmas and in defining global health ethics.
Some public health ethics frameworks describe potential approaches to public health problems through the lens of political theory. They describe the underlying philosophy and rationale of subjective and objective utilitarians, libertarians and liberal egalitarians, communitarians, and others, and the corresponding public health decisions that can be derived from the consistent application of one of these approaches. Others describe and try to resolve the tensions in public health practice and focus on key areas such as confinement and the limits of liberty, paternalism and the limits of autonomy, and surveillance and the limits of privacy. Still others outline principles and processes that should apply and guide public and global health activities. These include substantive principles such as duty of care, equity, individual liberty, privacy, proportionality, protection of the public from harm, reciprocity, solidarity, stewardship, and trust. Relevant procedural principles include openness and transparency, accountability, inclusiveness, reasonableness, and responsiveness. Global health ethics is a critically important, complex, and currently ill-defined field. While it may seem obvious that improving global health and minimizing health disparities are ethical imperatives in global health, the setting of priorities and defining effective and appropriate means of achieving these goals are neither intuitive nor straightforward. The various approaches and frameworks of global health ethics can begin to solve these dilemmas and aid in developing an implementable global health agenda. SEE ALSO: Global Health Council; Institute of Medicine
(IOM).
Bibliography. Howard Frumkin, Environmental Health:
From Global to Local (Wiley, 2005); Global Health Council, www.globalhealth.org/ (cited July 2007).
Barry Pakes, M.D., M.P.H. University of Toronto
Glomerular Diseases Glomerular diseases are a group of disorders that directly affect the main filtering unit of the kidney,
Goiter
which is called the glomerulus. The glomeruli are groups of blood vessels in the body that clear extra fluid and waste substances from the body. The glomeruli are attached to a series of small tubes (tubules), which also contribute the filtration process by controlling sodium and water concentrations in the body. Glomerular diseases damage the glomeruli and cause leaking of protein and other cells. This leakage disturbs the fragile environment of the kidney and without this balance; it is harder for the body to rid of wastes and extra fluid. There are two main groups of glomerular diseases: nephrotic syndromes and nephritic syndromes. Both of these syndromes affect the glomerulus in different ways and show different symptoms. Nephrotic syndrome has a more insidious onset and commonly occurs in association with systemic diseases that affecting multiple organs in the body. This includes illnesses like diabetes mellitus, systemic lupus erythematous, or amyloidosis. Nephritic syndrome has a quicker onset and occurs in association with infections of single organ systems. An example of this is a bacterium in untreated strep throat, which can damage the kidneys or a virus like chicken pox. Proteinuria, protein in the urine, is the hallmark finding of glomerular disease. Normally, the glomerular wall sorts blood proteins based on the size and charge and blocks proteins that are too large or charged from entering the urinary tubules. With glomerular damage this sorting ability is hindered, so large and charged proteins are allowed into the urine. Proteinuria is present in both nephrotic and nephritic syndrome so to differentiate the amount of 3.5 grams/deciliter is the cutoff, above this level is considered nephrotic and below it is nephritic. Nephrotic syndrome also shows low levels or blood protein, which manifests as swelling in face and extremities that occurs gradually over time. Another sign of nephrotic syndrome is high levels of blood cholesterol and triglycerides, which can show as fatty casts in the urine. Hematuria, blood in the urine, is a common finding in nephritic syndromes. Hematuria can be defined as gross, or visible to the naked eye, or microscopic, only seen by high-power microscopy. In nephrotic syndrome, hematuria is due to disturbance and damage to glomerular cells caused by inflammation. The presence of blood in the urine
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can also been seen by the presence of bloody casts in a urinary specimen. Other symptoms of nephritic syndrome include generalized aches and pains in joints and muscles, swelling in extremities and face, lethargy, blurry vision, and fatigue or malaise. Management of glomerular diseases The first step in the management of glomerular disease is treatment of the underlying condition. In nephrotic syndrome, it is important to control the systemic inflammation in order to preserve remaining kidney structure and function. In nephritic syndrome, the underlying bacterial, viral or immune infection must be treated with proper medication. By doing this, the infections are stopped from spreading even further. The next step in management is administration of diuretics and antihypertensives to facilitate ridding of the excess fluid and control of blood pressure. Another management step is to replace any vitamins and electrolytes that are lost with glomerular damage. It is also important to take measures to decrease blood cholesterol and monitor for risk of thrombotic events. SEE ALSO: Kidney Failure and Dialysis; Nephrology. Bibliography. Abul Abbas, et al., Robbins and Cotran:
Pathologic Basis of Disease 7th ed., (Elsevier Saunders, 1999); Mark Beers, Thomas Jones, and Robert Porter, Merck Manual of Diagnosis and Therapy 18th ed., Section 17, (Merck & Co. Inc, 1995-2006); Arthur Schneider and Phillip Szanto, Pathology BRS 2nd ed. (Lippincott, Williams & Wilkins, 2001). Angela Garner, M.D. University of Missouri–Kansas City
Goiter Goiter leads to a swelling in the front of the neck, just below the Adam’s apple or larynx, owing to an enlarged thyroid gland. This often results in the normal thyroid gland weighing 20 to 30 grams (0.75 ounces), turning into a goitrous gland which can swell to 1 kilogram (more than 2 pounds). The main cause of goiter is an iodine deficiency, and this is often called
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Gonorrhea
endemic goiter. It is curable by consumption of food heavily supplemented with iodine, in the form of iodate or iodide, and this remains largely a problem in poor countries. However, there are some other causes such as congenital hypothyroidism, thyroiditis, Hashimoto’s thyroiditis, Graves-Basedow disease, and other relatively uncommon disorders. Goiter can also occur when the thyroid gland has the normally functioning tissue but enlarges for reasons that are currently unknown. All these disorders causing goiter tend to result in the thyroid gland not being able to secrete sufficient amounts of the thyroid hormone, and hence the gland grows larger to try to make more to compensate for this. Goiter was common in parts of the English Midlands where there was an iodine deficiency in the soil. This led it to be called, colloquially, the “Derbyshire Neck.” For the same reason, goiter used to be found in the area around the Great Lakes, Midwest, and the Intermountain regions of the United States. It is also common in Tasmania. The man who realized that goiter should be treated with iodine was Jean-Baptiste-André Dumas, a professor at the University of Paris. Anton Freiherr von Eiselberg recognized that tetany cramps often resulted after a goiter operation. Nowadays, it is mainly found in India, Pakistan, central Asia, and central Africa. Peter Pitt, a doctor working in Nepal, spent many years curing people suffering from goiter in the Himalayan kingdom. Part of the reason for its prevalence there, it has been suggested, is because of the increased use of rock salt and/or sea salt which has not been fortified with iodine. People with goiter appear in many stories. In Little Dorrit by British writer Charles Dickens, there is a person “sunning his big goitre [sic].” Goiter also tends to be popular in novels set in imperial Rome. SEE ALSO: Thyroid Diseases. Bibliography. R.I.S. Bayliss, Thyroid Disease: The Facts
(Oxford University Press, 1998); Leslie J. DeGroot, The Thyroid and Its Diseases (Wiley, 1984); Franz Merke, History and Iconography of Endemic Goitre and Cretinism (MTP Press, 1984); Peter Pitt, Surgeon in Nepal (John Murray, 1970).
Justin Corfield Geelong Grammar School, Australia
Gonorrhea Gonorrhea is a very contagious sexually transmitted disease (STD). It is one of the most common venereal diseases in the world. It can be successfully treated with antibiotics, but without prompt treatment, sterility may occur. In addition, it may also cause congenital blindness. The gonorrhea bacterium (Neisseria gonorrhoeae) is the cause of the disease. It causes inflammation of the mucous membranes of the urogential tract. They may also affect the membranes of the throat, the conjunctiva, and the rectum. These infections are most likely if the infected person has engaged in oral or anal sex. Gonorrhea infections of the throat (gonoccal pharyngitis) can cause a sore throat, but often the infection is asymptomatic. Diagnosis can be made with a throat culture. In cases of rectal gonorrhea (gonococcal proctitis), symptoms may include anal discharge, pain on defecating, and rectal bleeding. The gonorrhea bacterium usually infects the columnar epithelium of the urethra and the endocervix. Symptoms of gonorrhea in men are a thick yellowgreen discharge from the penis. The symptomatic discharge can occur as early as two days after infection but usually no later than 14 days after infection. Most case present symptoms within two to five days after infection. In addition, the urethra will also be inflamed which will cause significant pain in urinating. Urination will be slow and difficult. In a small number of males, no symptoms are presented; however, they become carriers who can infect their sexual partners. In women, the cervix is usually the first place infected. Symptoms of gonorrhea are often absent which will allow infection of new partner(s) in future sexual encounters. In some females, symptoms do develop. These are usually slowly presented as vaginal discharge, painful urination, frequent urination, or pain in the lower abdomen. Infection with gonorrhea may occur in the throat or rectum. Symptoms are asymptomatic. Discovery of the disease occurs only with coincidental medical tests. Diagnosis of gonorrhea for males is made with a Gram’s stain test of the urethral discharge. The diagnosis is reliable in men. It can be performed in a physician’s office with a sample of the patient’s discharge. However, the test is not as reliable in women because gonorrhea bacteria can be con-
fused with other naturally occurring organisms in the vagina or uterus. Definitive diagnosis in women is made with a culture. New testing techniques examine the genes of the bacteria from a urine or cervical swab. This test is somewhat more accurate than the culture method. Treatment for gonorrhea with antibiotics is usually successful. However, successful treatment will not protect against reinfection through subsequent sexual contacts. Resistant strains of the gonorrhea bacteria since the 1970s have rendered penicillin and tetracycline ineffective. The problem of resistance is a continuing problem that threatens vast numbers of people globally. The Centers for Disease Control and Prevention declared gonorrhea bacterium a “super bug” in 2007. Antibiotics now used to treat gonorrhea include fluoroquinolones, spectinomycin, amoxycillin, ampicillin, and others. If the patient is pregnant, fluoroquinolones cannot be used. There are no known home cures for gonorrhea. Treatment has to be made by a physician. In addition all sexual partners must be identified to its further spread. Treatment for gonorrhea in an age of HIV/AIDS is very important because in increases the risk of contracting or transmitting HIV/AIDS. The weakening of the mucosal surface by the gonorrhea infection increases the opportunity for the AIDS virus to successfully invade the body. The use of a condom provides limited protection. If not treated and allowed to become chronic gonorrhea, it can spread from the mucous membranes into deeper tissues. The bladder, prostrate gland, and the epididymis may all become infected. Scarring of the urethra can occur, which will make urination slow and difficult. Sterility can occur in males and in females as well. In females, chronic infection with gonorrhea can lead to infection of the uterus, the fallopian tubes, and ovaries leading to eventual sterility. At child birth, a woman infected with gonorrhea can transmit the disease to her newborn baby as it passes through the birth canal. Treatment of all newborn’s eyes is standard in modern hospitals as a prophylactic measure. In women, chronic gonorrhea can enter the blood stream. Fever, infections of the joints, tendons, liver, skin, and rarely the heart or brain can occur in severe cases. See Also: Sexually Transmitted Diseases.
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Bibliography. Linda Kollar, Gonorrhea (Chelsea House
Publishers, 2005); Gonorrhea—a Medical Dictionary, Bibliography, and Annotated Research Guide to Internet References (ICON Health Publications, 2004); Amy L. Sutton, Sexually Transmitted Diseases SourceBook: Basic Consumer Health Information about Chlamydial Infections, Gonorrhea, Hepatitis, Herpes, HIV/AIDS, Human Papillomavirus, Pubic Lice, Scabies, Trichomoniasis, Vaginal Infections, and Others (Omnigraphics, 2006). Andrew J. Waskey Dalton State College
Gout and Pseudogout Gout and pseudogout are painful inflammatory disorders caused by the deposition of crystals in the joints. They are the two most common crystal-induced arthropathies. Gout results from high blood levels of uric acid which leads to a buildup of monosodium urate monohydrate crystals in joint tissue. Gout actually encompasses a variety of clinical presentations including hyperuricemia (elevated levels of uric acid in the blood), acute gouty arthritis (attacks of acute inflammatory arthritis due to the collection of monosodium urate monohydrate crystals in joint fluid), tophi (accumulations of monosodium urate monohydrate crystals within and around a joint and its surrounding soft tissues), gouty nephropathy (impairment of the kidneys due to crystal deposition), and uric acid urolithiasis (also known as urinary tract stones). Pseudogout is caused by the accumulation of calcium pyrophosphate crystals in the cartilage and joint fluid. Epidemiology Gout has become more prevalent over the last 30 years, not only in the United States, but also abroad. British and American studies have estimated gout to affect 2.6 to 8.4 per 1,000 adults. More than 2 million people in the United States live with this disease. Gout is nine times more common in men than in women. The 1995 National Health Interview Survey (American study) reported 8.5 per 1,000 adults have gout, and 5 percent of all arthritis cases are gouty arthritis. The onset of gout is most common in the fifth decade of life (ages 40–49). The disease is most
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prevalent in the elderly population; this is supported by a rate of 24 per 1,000 men and 16 per 1,000 women aged 65–74 years. These rates are increased from those published in 1986: 13.6 per 1,000 men and 6.4 per 1,000 women. It is the most common cause of inflammatory arthritis in men over 30 years of age. This condition is rarely seen in male children and teenagers as well as premenopausal women. Increased systemic estrogen during the reproductive years is likely to be the reason for lower rates of gout in women. Estrogen acts to increase elimination of uric acid from the body via the kidneys. There is also a racial predilection for gout: it is more common among Pacific Islanders. In the United States, it is twice as prevalent in African-American males than it is in Caucasian males. Gout is twice as prevalent as pseudogout. The conditions are similar in that incidence increases with age: calcium pyrophosphate crystals are found in approximately 3 percent of adults in their 60s; however radiologic surveys show evidence of chondrocalcinosis (calcium deposits in the joints) in 50 percent of people in their 90s. Studies have differed on whether the disease is predominant in men versus women. Pathogenesis Gout is due to hyperuricemia, or high levels of uric acid in the bloodstream. Uric acid is produced when purines are metabolized by liver enzymes (such as uricase). Purines are a part of all normal tissue. They may be endogenously produced as a by-product of normal cell turnover or they may come from the diet (seafood, liver, beans, gravy, sweet breads, anchovies, beer, wine). Typically, the body is able to regulate the amount of uric acid by balancing production with excretion. If the body produces too much uric acid or if an insufficient amount is excreted from the body, uric acid builds up in the blood and precipitates as monosodium urate crystals. Most people with gout tend to be underexcretors of uric acid. This may be due to kidney or digestive system malfunction. Pseudogout is due to the buildup of calcium pyrophosphate crystals. The crystals are produced by nucleoside triphosphate pyrophosphohydrolase (NTPPPH), an enzyme found within the cartilage of joints with preexisting osteoarthritis. Active gout and pseudogout represent an inflammatory host response to monosodium urate and cal-
cium pyrophosphate crystals, respectively. The crystals are perceived as foreign bodies, and so they are enveloped by white blood cells (the body’s natural defense system). White blood cells, specifically neutrophils, attempt to destroy the crystals, but the crystals trigger lysis of these cells. This causes a release of enzymes which damage local tissues, produce pain, and cause joint swelling (arthritis). The Stages of Gout Gout can progress through four stages: asymptomatic hyperuricemia, acute gouty arthritis, intercritical gout, and chronic tophaceous gout. Asymptomatic hyperuricemia is often a precursor to gout. This first stage is not yet considered gout, because some patients with high uric acid levels do not go on to develop crystal deposits or symptoms. They simply have high bloodstream levels of uric acid. However, many patients with hyperuricemia will go on to have deposition of crystals in the joint space and surrounding tissue prior to the onset of their first gouty arthritis episode. Acute gouty arthritis is characterized by a sudden onset of intense pain and swelling in a joint. It is the most common early presentation of gout. The attack usually occurs at night, and it may be triggered by stressful events, alcohol or drug ingestion, or a concurrent illness. The most common site to be affected is the metatarsophalangeal joint of the first toe. This site will eventually be involved during the overall course of illness in 75 percent of gout patients. The ankle, foot, and knee are other common sites of initial involvement. The affected joint(s) will be warm, tender, and red. A diffuse redness is usually evident surrounding the joint as well. An early attack may include chills, fever, pressure or tightness in the joint, and gnawing pain. Acute gouty arthritis episodes typically last three to 10 days, after which, a patient is often asymptomatic. The patient may be symptom-free for months to years. Subsequent attacks may occur more frequently, last longer, and involve multiple joints. Intercritical gout describes the asymptomatic periods between gout attacks. Despite the absence of symptoms, crystal deposition is still present. Therefore, a patient can still be diagnosed with gout during this time. Intercritical gout intervals can last months or years, but the majority of patients will have a second attack within two years.
Chronic tophaceous gout usually develops over a period of approximately 10 years. This advanced stage involves multiple joints; the pain persists without interruption and tophi are evident. Tophi (singular: tophus) are subcutaneous crystal deposits that can accelerate joint degeneration and lead to disability and deformity. They are often large, painless, and irregular; they contain white tophaceous material. If a tophus exists close to the skin surface, the chalky material can be removed by aspiration. Tophi may also ulcerate through the skin, and the white chalk or paste will exude from that opening. Tophi most frequently occur in the synovium (joint lining), subchondral bone, olecranon bursa, infrapatellar and Achilles tendons, extensor surface of the forearms, overlying joints, and on the helix of the ear. Chronic crystal deposition and inflammation cause erosion of the cartilage and underlying bone. Deformation is a potential complication of these processes. Other complications seen with advanced chronic gout include kidney damage (uric acid deposits can cause renal failure), urinary stones, hypertension, and albuminuria (abnormal presence of protein in urine; indicative of kidney disease). Diabetes mellitus, atherosclerosis of the heart and brain, and hypertrigliceridemia (high cholesterol) are more common among gout patients. Presentation of Pseudogout Pseudogout, as the name implies, has a very similar presentation to gout. Patients experience sudden joint pain that begins without warning. Pseudogout may affect one or multiple joints simultaneously; the affected joint(s) are red, swollen, warm, and stiff. Unlike gout which most commonly affects the first toe, pseudogout is most likely to attack the knees. Other common sites include the wrist, ankle, shoulder, elbow, and fingers. Attacks of pseudogout typically resolve spontaneously without treatment, although they may continue for weeks. Recurrences may occur quickly after an earlier attack. Causes of Gout and Pseudogout The main predisposing factors for gout are a family history of the condition, obesity, alcohol abuse, a high purine diet, and high cholesterol. In describing the causes of gout, patients may be broadly classified as overproducers or underexcretors
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of uric acid. The majority of patients (90 percent) are underexcretors; their kidneys excrete less uric acid than is necessary to maintain balance in the body. Underexcretion may be due to a genetic issue (primary hyperuricemia) or may be attributed to other factors, such as impaired renal function, ketoacidosis, lactic acidosis, dehydration, diuretics, hypertension, hyperparathyroidism, medications, and the effects of lead exposure. Overproducers of uric acid may have a variety of acquired and genetic disorders, and these are typically associated with high rates of cell turnover. Examples include hemolytic anemias, anemias associated with ineffective red blood cell production, psoriasis, myeloproliferative diseases (i.e., chronic myelogenous leukemia, polycythemia vera, essential thrombocythemia), and lymphoproliferative diseases (i.e., Hodgkin’s lymphoma, non-Hodgkin’s lymphoma). Uric acid overproduction may also be due to excessive dietary purine intake, glycogen storage diseases, severe muscle exertion, alcohol abuse, or fructose intolerance. Cases of pseudogout are classified as familial, associated with metabolic diseases or trauma (including joint surgery), or sporadic. Any kind of insult to the joint can trigger the release of the calcium crystals, inducing a painful inflammatory response. Research suggests that genetics play a role, as many patients with pseudogout have a family history of the disease. Although the exact cause of pseudogout is unknown, several risk factors have been determined for this condition: hypothyroidism, hemochromatosis (excessive iron storage in the body), hyperparathyroidism, stroke, heart attack, and hypercalcemia. Attacks of pseudogout may be precipitated by injury, stress, surgery, severe dieting, alcohol abuse, and use of thiazide diuretics. Laboratory and Radiologic Findings The diagnosis of gout and pseudogout is unequivocally made by taking fluid from the inflamed joint through a needle (joint aspiration) and examining the joint fluid with polarized light microscopy. A smear of joint fluid from a gout patient will show strongly negatively birefringent, needle-shaped uric acid crystals. A sample of fluid from a pseudogout patient will show positively birefringent calcium pyrophosphate crystals. X-rays can also be useful in diagnosing these two diseases. Typical radiographic features of gout are soft tissue swelling around the affected joint, subcutaneous and periarticular masses adjacent to eroded
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bone, overall retention of bone density and joint spaces, asymmetric distribution of erosions, and a thin overhanging edge of displaced bone at erosion sites. Septic changes and chondrocalcinosis (calcification of the cartilage) may also be present. The main radiographic feature of pseudogout is chondrocalcinosis. Calcified deposits are most likely to be seen at the lateral and medial meniscus of the knee, the acetabular labrum of the hip, the symphysis pubis of the pelvis, the articular disc of the wrist, and the annulus fibrosus of the intervertebral discs of the spine. In addition to joint fluid analysis and X-rays, a thorough history and physical examination is critical to making the diagnosis. Information regarding the use of medications, alcohol abuse, and environmental exposures (such as lead) may suggest the presence of gout or pseudogout. Routine laboratory tests may also be done to detect comorbid conditions or associated diseases, such as chronic renal disease, sickle cell disease, polycythemia vera, leukemia, and Hodgkin’s disease. Treatments The first-line therapies for both gout and pseudogout are nonsteroidal antiinflammatory drugs (NSAIDs). NSAIDs decrease joint swelling and are effective for pain relief. Occasionally, additional medication is needed for pain; examples include codeine and meperidine. Colchicine is an alternative to NSAIDs for treatment of acute attacks. It can be administered orally every hour until symptoms are relieved or can be given intravenously to relieve inflammation and pain. Joint pain typically begins to wane after 12 hours and is completely relieved in 36 to 48 hours. It was once the treatment of choice for gout; however its use has been curtailed due to side effects of severe abdominal pain and diarrhea. Occasionally, colchicine has caused bone marrow damage. Since other effective treatments with fewer side effects are currently available, use of colchicine has fallen out of favor. Corticosteroids, such as prednisone, are another treatment option for acute attacks. These medications can be given orally (systemic steroids) or be prepared as a suspension which is injected into the joint (intra-articular steroids). Corticosteroids are often given to elderly patients with impaired renal function that cannot take NSAIDs. Besides addressing acute attacks, treatment should also be aimed at preventing recurrences. Prevention of
attacks does not prevent or heal joint damage which has already been done, but it will limit its progression. Lifestyle modifications should be encouraged, including avoiding alcoholic beverages, limiting the intake of purine-rich foods, stopping medications that increase blood levels of uric acid, and losing weight. Long-term prophylaxis may be accomplished with allopurinol. This medication should be started one month after an acute attack. Allopurinol blocks the production of uric acid in the body; it is a valuable option for patients with severe hyperuricemia. Side effects include nausea, hypersensitive skin rash, immunocompromise, and liver damage. Uricosuric drugs, such as probenecid and sulfinpyrazone, are also used for prophylaxis. These drugs promote excretion of uric acid in the urine. Patients who are given this therapy should have good kidney function in order to be able to tolerate the increase in renal workload. Last, colchicine and NSAIDs may be taken daily to prevent attacks. Treatment of pseudogout parallels the recommendations for gout. NSAIDs and corticosteroids can be given to decrease inflammation and pain. NSAIDs are the most commonly prescribed treatment. Joint aspiration can be done in order to remove fluid, and thus crystals from the area, to relieve pressure, pain, and stiffness from the joint. In severe chronic cases, surgery is a possibility. Calcified or otherwise damaged cartilage can be removed from the joint and bone can be repaired. Joint replacement is the most intense therapeutic option. Currently, there is no effective prevention for pseudogout attacks. Muscle strengthening and stretching are recommended to improve joint stability (thereby reducing injury which may trigger pseudogout episodes) and mobility over the long term. See also: Arthritis; Calcium; Rheumatoid Arthritis. Bibliography. Daniel J. McCarty, “Calcium Pyrophos-
phate Dihydrate Crystal Deposition Disease,” Primer on the Rheumatic Diseases (Arthritis Foundation, 1993); Lawrence M. Ryan and Daniel J. McCarty, “Arthritis Associated with Calcium-Containing Crystals,” Internal Medicine, Ed. Jay H. Stein (Mosby, 1998); Guillermo A. Tate, and H. Ralph Schumacher, Jr., “Gout: Clinical and Laboratory Features,” in Primer on the Rheumatic Diseases (Arthritis Foundation, 1993); Robert Terkeltaub, and Jay H. Stein, eds., “Gout and Hyperuricemia,” Internal Medicine, (Mosby, 1998); Robert Terkeltaub, and H. Ralph Schumacher, Jr., eds., “Gout: Epi-
Greece
demiology, Pathology, and Pathogenesis,” in Primer on the Rheumatic Diseases (Arthritis Foundation, 1993). Stacy A. Frye, M.D. Michigan State University
Greece With a per capita income of $22,300, Greece is the 45th richest nation in the world. The population has easy access to healthcare. The Greek economy is basically strong and is currently growing at a rate of 3.7 percent. However, unemployment (9.9 percent) and inflation (3.5 percent) are both higher than average for members of the European Union. Around 12 percent of the workforce is involved in the agricultural sector, and almost three-fourths are involved in services. Because of its ancient heritage and temperate climate, Greece draws visitors from all over the world, and tourism provides 15 percent of the Gross Domestic Product (GDP). The government does not issue an official poverty report, but some of the poorest residents are immigrants who are concentrated in menial jobs. Income disparities do exist, and Greece ranks 35.1 on the Gini index of inequality. The poorest 10 percent are able to claim only three percent of resources while the richest 10 percent hold 28.3 percent. The standard of living is reasonably high, and the United Nations Development Programme’s (UNDP) Human Development Report ranks Greece 24th of 177 countries on overall quality-of-life issues. Much of the responsibility for healthcare in Greece is concentrated in the private sector, which accounts for 48.7 percent of health costs. Some 95.40 percent of private resources involve out-of-pocket expenses. On the average, seven percent of the total government budget is allocated to healthcare. Approximately 10 percent of the GDP is directed toward healthcare, and the government allocates $1,997 (international dollars) to health-related programs. The government is responsible for over half (51.3 percent) of all health expenditures, and 32 percent of funding is earmarked for Social Security. All regular employees and some self-employed workers are covered under the social insurance plan. The program is financed through a combination of employee contributions (6.67 to 8.86
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percent of wages), employer benefits (13.33 to 14.73 percent of payroll), and government supplements (10 percent). Reforms to the existing pension system are under way. Workers receive cash benefits for illness and maternity leave. Both mothers and fathers are eligible for a one-year leave for the birth of a child, and leave time is expanded for the birth of additional children. Parents with children in public schools receive a family allowance, distributed at the beginning of each school year, for all children 16 and under. There are 4.38 physicians, 3.86 nurses, 0.18 midwives, 1.13 dentists, and 0.82 pharmacists per 1,000 population in Greece. In order to improve access to healthcare, the government instituted the Integration Action Plan and charged the Ministry of Health and Social Care with establishing 50 socio-medical centers and two mobile units. The services of a doctor, a nurse, a social worker, a physical trainer, and a special health promoter are available at each center. Patients who need further treatment are directed to area hospitals. Help for families in crisis is provided by the National Center of Immediate Social Assistance, which provides care and support for neglected children, victims of domestic violence, and the elderly who live alone. Life expectancy is the 25th highest in world, and the Greek population of 10,688,058 people can expect to live an average of 79.24 years. Females outlive males by about five years. While the vast majority of all Greeks over 15 are able to read and write, there is a slight disparity between male (98.6 percent) and female (96.5 percent) literacy rates. Most children attend primary school regularly, but only 87 percent of females and 85 percent of males regularly attend secondary school. Greek women give birth at a rate of 1.34 children each. The adjusted maternal mortality rate is nine deaths per 1,000 live births. Birth control has become a government concern, and information on family planning, abortion, and sexually transmitted diseases is widely distributed Family Planning Centers are set up in many hospitals, operating under the auspices of the Foundation for Social Insurance. Infant mortality is currently reported at 5.43 deaths per 1,000 live births. Between 1990 and 2004, infant and under-5 mortality were more than halved, dropping from ten to four and from 11 to five deaths per 1,000 live births, respectively. Eight percent of all infants are
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underweight at birth. While 96 percent of infants are immunized against diphtheria, pertussis, and tetanus (DPT1), all other immunization rates are in the high 80s: 88 percent of infants are immunized against DPT3, tuberculosis, measles, hepatitis B, and Haemophilus influenzae type B (Hib3) and 87 percent against polio. Earthquakes may present a safety hazard in Greece, and industrialization has led to air and water pollution that threaten general health. HIV/AIDS also causes some concern in Greece. With a 0.2 percent adult prevalence rate, some 9,100 Greeks are living with HIV/AIDS. The disease has caused the deaths of around 100 people. An outbreak of severe acute respiratory syndrome (SARS) created a public scare in spring 2002. Human trafficking poses a constant to threat the general well-being of the population, and both children and adults are victims of forced labor and sexual exploitation. Greece has the highest rate of smokers in Europe and one of the highest rates in the world. According to recent studies, 51 of men and 39 percent of women smoke. While the governments in several other European nations have imposed major restrictions on public smoking, cultural dictates make the government of Greece reluctant to do so. A new law prohibiting smoking in the workplace is generally ignored. Tobacco products do carry warnings, but opinion polls indicate that most Greeks consider them as annoyances rather than deterrents. Antismoking efforts have been greatly hindered by the presence of a strong tobacco lobby. See Also: European Public Health Association (EUPHA);
Smoking; World Health Organization (WHO).
Bibliography. Central Intelligence Agency, “Greece,”
World Factbook, www.cia.gov/cia/publications (cited July 2007); Commission on the Status of Women, “Greece,” www.un.org/womenwatch (cited July 2007); Spencer Di Scala, Twentieth Century Europe: Politics, Society, Culture (McGraw-Hill, 2004; Sandra Halperin, War and Social Change in Modern Europe: The Great Transformation Revisited (Cambridge University Press, 2004); Martin A. Levin and Martin Shapiro, eds., Transatlantic Policymaking in an Age of Austerity: Diversity and Drift (Georgetown University Press, 2004); Jeremy Rifkin, The European Dream: How Europe’s Vision of the Future Is Quietly Eclipsing the American Dream (Jeremy P. Tarcher/Penguin, 2004); Social Security Administration, “Greece” www.ssa.
gov (cited July 2007); UNICEF, “Greece” www.unicef.org/ infobycountry/greece_statistics.html; C.I. Vardavas and A. Kafatos, “Greece’s Tobacco Policy: Another Myth?” The Lancet, (May 6, 2006); World Bank, “Greece Data Profile,” /devdata.worldbank.org (cited July 2007). Elizabeth R. Purdy, Ph.D. Independent Scholar
Grenada Grenada is a small island at the southern end of the Grenadines, a short archipelago at the boundary of the Caribbean Ocean and the North Atlantic. At just 344 square kilometers, it is one of the smallest independent nations in the western hemisphere. Few Americans had heard of Grenada before October 1983, when hundreds of U.S. troops invaded the island to oppose Cuban troops building an airstrip. Operation Urgent Fury lasted just a few days and took the lives of 19 U.S. servicemen and 100 Cubans and Grenadians. The Cubans retreated, and the Grenadians welcomed the United States as liberators. Since the 1980s, Grenada has been a peaceful place, with an economy based on tourism, offshore finance, agricultural exports, and manufacturing. The total population is 89,700, and the growth rate is only 0.26 percent. Grenada has a birth rate of 22.08 per 1,000 people and a death rate of 6.88 per 1,000 people, but its migration rate is minus 12.59 per 1,000. Sixty-two percent of Grenadians work in the service industry, 24 percent in agriculture, and 14 percent in industry. Unemployment is 12.5 percent. Per capita income is $4,060, although a third of Grenadians live below the poverty level. Grenada lies at the edge of the Atlantic hurricane belt, with little to protect it from tropical systems. In 2004, Hurricane Ivan swept the island, taking no lives but destroying or damaging 90 percent of the residential housing. The economy is still recovering from the blow. Life expectancy at birth is 63.06 years for males and 66.68 years for females; healthy life expectancy is 58.4 years for men and 60 years for women. Infant mortality is just 14 deaths per 1,000 live births, and almost every child survives childhood. Immunization for the major diseases of childhood is almost uni-
Growth Disorders
versal. Between 1990 and 2004, there was only one reported death in childbirth. All Grenadian women have a trained attendant monitoring their deliveries, and 98 percent receive prenatal care. The local diet is based on cereal grains, yams, cassava and other root vegetables, shrimp, and fish. Nutmeg, mace, cinnamon, cloves, citrus fruits, and bananas are major export crops. The government has launched a campaign to “grow what you eat and eat what you grow” to encourage both a healthy diet and a reduced dependence on expensive, imported foods. With the exception of a few isolated cases of dengue fever, Grenadians are not plagued with major infectious diseases. Between 95 to 97 percent of citizens use safe drinking water and sanitary facilities. The HIV/AIDS rate is low, with 139 cases diagnosed between 1996 and 2001. Workplace accidents are common. Cardiovascular disease and cancers are the most common causes of death. The government allocates $212 per capita for medical care. There is one general hospital in St. George’s and two rural hospitals in the countryside. The Ministry of Health plans to establish several local “polyclinics” to better serve people for basic health needs. For the past 30 years, doctors have been a chief export for Grenada, thanks to the St. George’s University (SGU) School of Medicine. Since its establishment in 1977, SGU has used its low tuition and tropical locale to attract medical students from around the globe. Today, there are 5,000 SGU-trained physicians practicing in 35 countries and all 50 U.S. states. SEE ALSO: Healthcare, South America. Bibliography. Pan American Health Organization,
“Grenada,” http://www.paho.org/English/SHA/prflgre.htm (cited June 2007); World Health Organization, “Grenada,” http://www.who.int/countries/grd/en/ (cited June 2007).
Heather K. Michon Independent Scholar
Growth Disorders Child growth is internationally recognized as an important public health indicator for monitoring nu-
753
tritional status and health in populations. Growth is influenced by many factors such as heredity, genetic or congenital, illness and medications, nutrition, hormones, and psychosocial environment. Measurements of growth—height and weight—are a very inexpensive service that should be offered by all healthcare providers rendering care to children. The internationally recommended way to assess malnutrition at population level is to take body or anthropometric measurements (e.g., weight and height). Based on combinations of these body measurements, anthropometric indices are constructed. These indices are essential for the interpretation of body measurements as, for example, weight alone has no meaning unless it is related to an individual’s age or height. In children, the three most commonly used anthropometric indices are weight for height, height forage, and weight for age. These indices can be expressed in terms of z-scores, percentiles, or percentage of median, which enable comparison of a child or a group of children with a reference population. A normal growth pattern does not guarantee overall health; however, children with abnormal growth patterns frequently have nutritional complications of specific clinical disorders (e.g., cystic fibrosis, inflammatory bowel disease) or poor socioeconomic conditions. A child who is two standard deviations (SDs) or more below the mean height for children of that sex and chronologic age (and ideally of the same racial ethnic group) is said to have short stature. A single measurement of height is much less important in assessing growth than is the pattern of growth over a period of time; the key finding is slowed growth that progressively deviates from a previously defined growth channel (or percentile). Children who suffer from growth retardation as a result of poor diets and/or recurrent infections tend to have more frequent episodes of severe diarrhea and are more susceptible to several infectious diseases, such as malaria, meningitis, and pneumonia. In addition, there is strong evidence that impaired growth is associated with delayed mental development, poor school performance, and reduced intellectual capacity. Causes of Poor Growth Children are a reflection of their parents’ growth patterns and height. Parents who were late bloomers and experienced slow growth and late pubertal
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development may see the same pattern in their children. The final height these children achieve is usually normal. Parents who have short stature usually have children whose adult height potential is in the shorter range. Conversely, tall parents usually have tall children. As a general rule, a child’s potential adult height ranges between the average of the parents’ heights toward that of the parent who is the same sex as the child. Congenital (those present at birth) causes for growth failure include intrauterine growth retardation, skeletal abnormalities, and chromosome changes. Intrauterine growth retardation may result from maternal infections, smoking, or alcohol/drug use while pregnant. Skeletal causes, such as short-limbed dwarfism, result from abnormal production of new bone and cartilage. These children usually have unusual trunk/limb proportions. Chromosome variations causing short stature can include Turner’s syndrome in girls and Down syndrome. Conditions that are considered chronic can reduce growth because they interfere with the body’s ability to use nutrients properly. Diseases that involve the kidneys, digestive tract, heart, or lungs are examples of such conditions that may influence growth. Some medications that are used in large doses or for long periods of time may affect growth. Nutritional problems can influence growth in two ways. More commonly, the problem is a poor diet with inadequate nutrients, not enough calories, or the wrong food groups. Second, diseases that interfere with the absorption of food from the bowel will prevent the body from using those nutrients for growth. In these cases, symptoms may include nausea, vomiting, excessive gas, diarrhea or constipation, poor weight gain, or being underweight for height. After diagnosis, these problems usually improve with a special diet and or medications. With proper correction of these disorders, growth will also improve. Children in situations where home life is disrupted or unhappy or where there is a lack of love, of consistency, or of emotional support, experience severe stress. This stress can precipitate growth failure. Growth resumes when the problems are relieved and the stress is gone. Growth failure caused by endocrine disorders is uncommon, but is often easily remediable. Thyroid function should always be evaluated, because growth failure may be the first or even the only manifesta-
tion of hypothyroidism. The evaluation should include measurements of both serum thyrotropin (TSH) and thyroxine; both primary and central hypothyroidism can cause growth failure, and measurement of serum TSH alone will not detect central hypothyroidism. Cushing’s syndrome is rare in children except when due to the toxicity of glucocorticoid therapy. It is initially a clinical diagnosis that is suggested by the clinical findings and then confirmed by biochemical and imaging tests. A corticotrophin (ACTH)-secreting pituitary adenoma (Cushing’s disease) is by far the most common cause. The two major findings are weight gain (90 percent) and growth retardation (83 percent); bone age tends to be normal at diagnosis in most patients. If growth hormone deficiency is congenital and complete, the diagnosis is relatively easy to confirm. Affected children present with severe growth failure, delayed bone age, and very low serum concentrations of growth hormone, IGF-I, and its major binding protein, IGF-binding protein-3. Provocative testing of growth hormone secretion with insulin-induced hypoglycemia, as may be performed in adults with suspected growth hormone deficiency, is not recommended in children. The rare children with growth hormone insensitivity have high serum growth hormone concentrations but low serum IGF-I and IGF binding-protein-3 concentrations. In its complete form, this condition is called Laron-type dwarfism (complete growth hormone insensitivity). Causes of Excessive or Rapid Growth Children who are above the 95 percentile in height or are growing unusually fast for their age may need to be evaluated by their physician. Although tall stature is almost as common as is short stature, few children or their families seek medical attention, presumably because tall stature is socially acceptable and often advantageous. Nevertheless, it is critical to be able to identify situations in which tall stature or an accelerated growth rate provides a clue to an underlying disorder. Determining the heights of the biological parents is of critical importance because their height reflects the genetic component for growth and development of the child. When dysmorphic features are found, special effort should be made to rule out the disorders and syndromes that are associated with excessive growth. Causes of rapid growth that may be abnormal include excessive growth hormone production, some congenital growth hor-
mone production, some congenital genetic conditions, or early puberty. Signals of these problems may include unusual body proportions, breast growth, enlargement of the genitals, and axillary and pubic hair growth. Central (or true) precocious puberty refers to the early occurrence of normal puberty. Precocious puberty has been defined as sexual development in girls before the age of 8 years and in boys before the age of 9 years; however, current data for girls, particularly black girls, indicate that the age of onset of normal puberty is younger. The hallmarks of precocious puberty are accelerated growth and advanced bone age, plus breast development in girls and penile enlargement and sexual hair growth in boys. The pattern of secretion of pituitary gonadotropins and gonadal sex steroids is normal but early. Pseudoprecocious puberty refers to sexual precocity due to adrenal or gonadal disorders or rarely tumor production of human chorionic gonadotropin. The clinical manifestations are similar to those of central precocious puberty, except that the sexual development may be that of the opposite sex, for example, androgen effects in girls with congenital adrenal hyperplasia. Any cause of sexual precocity (including exogenous) can awaken the hypothalamic-pituitary axis for normal pubertal development and “induce” central puberty as well. Excessive growth hormone secretion causes gigantism in growing children and acromegaly after fusion of the epiphyseal growth plates, usually in adults. Although rare in children, the possibility of gigantism should be considered when the height exceeds +3 to +4 SDs. Pituitary growth hormone-secreting tumors usually are eosinophilic or chromophobe adenomas. Their cause is unknown, although many result from somatic mutations that generate activated G proteins with reduced guanosine triphosphatase (GTPase) activity. Growth hormone-secreting tumors also have been reported in patients with multiple endocrine neoplasia type 1, neurofibromatosis, or tuberous sclerosis. Hyperthyroidism caused by endogenous overproduction or overtreatment with exogenous thyroxine may lead to increased growth, advanced bone age, and, in early life, craniosynostosis. The tall stature and transient increase in linear growth usually do not require intervention, and the growth rate normalizes with treatment of the hyperthyroidism.
Growth Disorders
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Permanent hypogonadism, that is, permanent deficiency of testosterone in males or of estrogen in females, results in delayed skeletal maturation, a prolonged period of growth, tall stature, and eunuchoid proportions, with long legs and low upperlower segment ratio. As an example, several patients with estrogen deficiency resulting from aromatase deficiency or estrogen resistance caused by a mutation of the estrogen receptor gene who were tall have been described. Familial glucocorticoid deficiency is a rare autosomal recessive disorder characterized by hypoglycemia, seizures, increased skin pigmentation, and in some cases tall stature or advanced bone age. Biochemical findings include extremely high serum corticotrophin (ACTH) concentrations together with low or undetectable serum cortisol concentrations that do not respond to exogenous ACTH stimulation. Type 1 familial glucocorticoid deficiency is caused by mutations in the ACTH receptor gene, whereas some other defect is responsible for type 2 familial glucocorticoid deficiency. Excessive production of adrenal androgens probably is responsible for the tall stature. Another suggestion is that the high serum ACTH concentrations could activate melanocyte-stimulating hormone receptors in cartilaginous growth plates and that the increase in height is caused by the unopposed anabolic action of growth hormone. Primary cortisol resistance is a rare cause of hypercortisolism but may cause excessive growth because of the effects of the increased ACTH levels on adrenal androgen production. Because this is gonadotropin-independent precocity, the size of the testis is relatively small compared to the degree of growth and virilization. The bone age is advanced and many quite tall boys do not become excessively tall adults. Congenital total lipodystrophy is a rare autosomal recessive disorder. The main clinical features, in addition to overgrowth and acromegaloid changes, are generalized absence of subcutaneous fat, muscular hypertrophy, hyperpigmentation, enlargement of the penis or clitoris, advanced bone age, insulin resistance, hyperinsulinemia, hyperlipidemia, and nonketotic hyperglycemia. Large doses of insulin are given to avoid decompensation, but normoglycemia may not be attainable. Adult height in these patients tends to be normal or tall.
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Klinefelter syndrome is caused by an abnormality in chromosome number in which two or more X chromosomes are present in phenotype males. The most common abnormal karyotype is 47 XXY. Prepubertal boys often are tall for their age, with relatively long legs, and they may have learning disabilities, mainly in expressive language. Small testes and gynecomastia are the most common features on physical examination. Serum luteinizing hormone and follicle-stimulating concentrations are high in patients with Klinefelter syndrome. Usually, serum testosterone concentrations are in the low normal adult range. Testosterone treatment can be initiated during the pubertal years to facilitate development of secondary sexual characteristics and minimize the psychological complications of hypogonadism. This approach also may diminish adult height. Marfan syndrome is an autosomal dominant abnormality of connective tissue characterized by tall stature, long thin fingers (arachnodactyly), hyperextension of joints, and superior lens subluxation. Pectus excavatum, scoliosis, aortic or mitral regurgitation, and aortic root dilatation may be present. Female and male patients with this syndrome may attain excessively tall height, and treatment with estrogen in women and testosterone in men may be indicated, especially if any orthopedic problem is present. Homocystinuria is an inherited inborn error of methionine metabolism, caused by a deficiency of the enzyme cystathionine synthetase. Some of the clinical features are similar to those of Marfan syndrome, with subluxation of the lens being the most consistent finding. In addition, 50 percent of patients have mental retardation, life-threatening thromboembolic phenomena may occur at any age, and early onset of osteoporosis is seen. Neurofibromatosis type 1 is an autosomal dominant disorder that comprises approximately 90 percent of all cases of neurofibromatosis. It is caused by an abnormality of neural crest differentiation and migration during the early stages of embryogenesis. Short stature is common, but some patients are excessively tall. Thus, neurofibromatosis should be considered in patients with overgrowth. For many years, the World Health Organization (WHO) Department of Nutrition has been using anthropometric data to monitor trends in child malnutrition. A major difficulty has been the nonuni-
formity of survey analyses and presentation of their results. Although numerous nutritional surveys have been conducted since the 1970s, many of them have used distinct definitions of malnutrition (i.e., different anthropometric indices, reporting systems, cutoff points, and reference values), thus making comparison of results between studies difficult. This lack of comparable data prompted the beginning of WHO’s systematic collection and standardization of information on the nutritional status of the world’s under-5 population. The WHO Global Database on Child Growth and Malnutrition was initiated in 1986 to compile, standardize, and disseminate results of nutritional surveys performed worldwide. The specific objectives of this database are to characterize nutritional status; enable international comparisons of nutritional data; identify populations in need; help evaluate nutritional and health interventions; monitor secular trends in child growth; and raise political awareness of nutritional problems. A distinct feature of the database is the systematic analysis of raw data sets in a standard format to produce comparable results. SEE ALSO: Endocrine Diseases (General); Klinefelter’s
Syndrome; Marfan Syndrome; Tanner Stages.
Bibliography. C.E. Brain and M.O. Savage, “Growth
and Puberty in Chronic Inflammatory Bowel Disease,” Baillière’s Clinical Gastroenterology (v.8, 1994); P. Chatelain, “Trends in the Diagnosis and Treatment of Short Stature as Revealed by KIGS,” in M.B. Ranke and P. Wilton, eds., Growth Hormone Therapy in KIGS: 10 Years’ Experience (Johann Ambrosius Barth Verlag, 1999); A. Grimberg, J.K. Kutikov, and A.J. Cucchiara, “Sex Differences in Patients Referred for Evaluation of Poor Growth,” Journal of Pediatrics (v.146, 2005); S.L. Kaplan and M.M. Grumbach, “Pathophysiology and Treatment of Sexual Precocity,” Journal of Clinical Endocrinology and Metabolism (v.71, 1990); A.D. Rogol and E.L. Lawton, “Body Measurements,” in J.A. Lohr, ed., Pediatric Outpatient Procedures (J. B. Lippincott, 1991); J.M. Tanner, H. Goldstein, and R.H. Whitehouse, “Standards for Children’s Heights at Ages 2 to 9 Years Allowing for Height of Parents,” Archives of Disease in Childhood (v.45, 1970). Barkha Gurban, B.A. University of California, Los Angeles
Guatemala
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Guatemala Guatemala girdles the width of Central America, wedged between Mexico and Belize on the north and Honduras and El Salvador on the south. Most of the coastline is on the Pacific Ocean, but there is access to the Atlantic on the Gulf of Honduras. Guatemala is a beautiful country, with a volcanic mountain range and lush tropical lowlands and an ancient indigenous culture. Still, life there is difficult, with 75 percent of the people living below the poverty line. The country has a population of about 12.3 million (2006 estimate), growing at 2.27 percent annually. The birth rate is 29.88 per 1,000 people, the death rate 5.2 per 1,000 people, and the migration rate is minus 1.94 migrants per 1,000 people. The urbanization rate is 46 percent, with more and more people moving into the cities in search of work. The economy is driven mainly by agricultural exports, particularly coffee, bananas, and sugar. Fifty percent of the workforce is involved in agriculture. Per capita income is $4,080, but uneven distribution of land and wealth means that poverty is widespread. Sixteen percent of Guatemalans live on $1 a day or less. There are two Guatemalas when it comes to both wealth and health. Sixty percent of the population is of Amerindian-Spanish descent, known as mestizo or ladino. The rest of the people are indigenous, with 23 Mayan groups alone. Indigenous people tend to live in the mountains, far from adequate healthcare or decent food sources. For Guatemalans overall, life expectancy at birth is 67.65 years for males and 71.18 years for females, with healthy life expectancy averaging 54.9 years for men and 59.9 years for women. However, the life expectancy for indigenous people is, on average, 17 years shorter. Maternal mortality is 89 deaths per 100,000 live births nationally, but in the indigenous region of Alta Verapaz, it is 192 deaths per 100,000 live births. Guatemala’s location and geography make it vulnerable to a number of natural disasters affecting health and safety. Active volcanoes in the mountains lead to frequent damaging earthquakes. Tropical storm systems routinely cross the country. In October 2005, Hurricane Stan made a direct hit on the Yucatán Peninsula; flooding and mudslides caused the deaths of an estimated 2,000 to 3,000 people in Guatemala alone. Ninety-five percent of Guatemalans have access to clean drinking water and 61 percent have sanitary
Life in Guatemala is difficult; 75 percent of the people are living below the poverty line.
facilities, although, again, these rates are much different in indigenous areas. Major infectious diseases are largely under control, with only sporadic outbreaks of cholera, leptospirosis, and meningitis in recent years. Pneumonia and acute diarrhea are still common. The average Guatemalan is more likely to be affected by cardiovascular disease, cancer, or diabetes. In the cities, death by accident, suicide, or violent crime is common. Guatemala is a major transit point for cocaine and heroin, and in 2004, the country reawakened its dormant opium industry. Domestic violence and random violence against women is common in urban areas. More than 2,300 young women have been found raped, mutilated, and murdered since 2001. These crimes, like most homicides in Guatemala, go unsolved. The HIV/AIDS rate has remained fairly low, with 1.1 percent of the population estimated to be infected as of 2003. About 78,000 Guatemalans are living with the virus, and 5,800 people have already died of it. The government spends $112 per person annually on healthcare. The constitution recognizes health as a fundamental human right, and healthcare is supposed to be free for those without means. In recent years, the government has worked to improve healthcare among the Mayan, Garifuna, and Xinka people, although this investment has not yet paid off. In 2000, there were 43 hospitals and 1,309 mixed healthcare
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posts, maternity centers, general clinics, emergency centers, and mental health centers spread throughout the country. The World Health Organization estimated that there are 9,965 physicians and 44,986 nurses to serve the population. SEE ALSO: Healthcare, South America. BIBLIOGRAPHY. Walter Randolph Adams and John Palm-
er Hawkins, Health Care in Maya Guatemala: Confronting Medical Pluralism in a Developing Country (University of Oklahoma Press, 2007); Gerard M. La Forgia, ed., Health System Innovations in Central America: Lessons and Impact of New Approaches (World Bank Publications, 2005). Heather K. Michon Independent Scholar
Guillain-Barré Syndrome In 1859, Jean Landry first described what is likely now called Guillain-Barré syndrome or acute inflammatory demyelinating polyradiculoneuropathy (AIDP). William Osler later elaborated on this description in 1892. In 1916, Georges Guillain, Jean Alexandre Barré, and Andre Strohl refined the definition and clinical picture of Guillain-Barré syndrome by analyzing the cerebrospinal fluid of these patients. With this information, one could then distinguish Guillain-Barré syndrome from anterior horn cell disease processes. Guillain-Barré syndrome is an autoimmune-mediated disease that involves demyelination of peripheral nerves and associated inflammatory cells or an axonal degeneration with or without demyelination and inflammation. It most commonly causes muscle weakness or paralysis and is thought to be due to an irregular immune response often preceded by an infection, such as Epstein-Barr virus (EBV), cytomegalovirus (CMV), hepatitis, varicella, Mycoplasma pneumoniae, or Campylobacter jejuni. Specifically, the mechanism of action involves the destruction of peripheral nerve fibers via T-cell lymphocytes and macrophages. When Guillain-Barré syndrome was first described, it was believed to be a single disorder, but now the syndrome has been associated with many
variants. The National Institute of Neurological Disorders and Stroke (NINDS) developed the criteria for the diagnosis of Guillain-Barré syndrome. At a minimum, the individual must have progressive weakness of at least two limbs as well as areflexia. The most common form of Guillain-Barré syndrome in Europe and the United States is the acute inflammatory demyelinating polyradiculoneuropathy (AIDP). Other less common variants include the Miller-Fisher syndrome, acute motor axonal neuropathy (AMAN), and acute sensorimotor axonal neuropathy (AMSAN).These other variants occur more commonly in regions of the world such as China, Japan, and Mexico. This syndrome afflicts approximately 2 in 100,000 individuals and is not associated with any particular race or geographical distribution. However, adult men have a slightly greater risk of having GuillainBarré syndrome than adult women. After the age of 40, the risk for acquiring Guillain-Barré syndrome increases until the age of 80. The most recent epidemic of Guillain-Barré syndrome in the late 20th century occurred in northern China (AMAN variant) and had been attributed to C. jejuni infection. Typically, the afflicted individual has progressive motor weakness and areflexia starting in the proximal legs. The progression of Guillain-Barré syndrome is variable, ranging from hours to weeks. Often, they will complain of balance problems, paresthesias, and ascending weakness from the lower extremities to the upper extremities. The extent of weakness ranges from mild weakness to complete paralysis. Lower extremity weakness may manifest as foot drop. One of the most severe complications of this disease is respiratory compromise, resulting from weakness of the respiratory muscles. Dysautonomia is a common comorbidity that may manifest itself as arrhythmias, urinary retention, decubitus ulcers, constipation, gastritis, or ileus. The individual may also suffer from mood or anxiety problems. The disease process usually occurs within two to four weeks of an illness or immunization. In addition to weakness, the disease may manifest as pain, leading to misdiagnosis, particularly in children. Guillain-Barré syndrome may not present with weakness as the primary symptom. In fact, the Miller-Fisher variant is defined by the presence of ophthalmoplegia, ataxia, and areflexia.
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Once Guillain-Barré syndrome is suspected based upon physical findings and a clinical history, a lumbar puncture should be completed to look for demyelination without active infection. A magnetic resonance imaging (MRI) of the spine may help to confirm the diagnosis generally two weeks after the first onset of ascending weakness. The lumbosacral MRI will show enhancement of the cauda equina nerve roots. Abnormal electrodiagnostic studies may be useful within the first two weeks as well. Glycolipid antibody analysis is also useful because different forms of Guillain-Barré syndrome express different antibodies. For example, GQ1b antibodies are present in the MillerFisher variant, while GD1b has been linked to pure sensory GB syndrome. Current treatment is focused on immunomodulation. Initially, intravenous immunoglobulin (IVIG) is given to the patient. While an individual may benefit from short-term IVIG treatments, there is no definitive evidence that IVIG is beneficial in the long term. Another potential treatment is plasmapharesis. Recent studies have suggested that plasmapheresis may decrease the severity and duration of the disease. This treatment may have complications, including autonomic instability, hypercalcemia, or bleeding. Steroids have also been used in the past but are no longer considered efficacious. Physical activity is encouraged in these patients, although patients should be monitored for autonomic symptoms. If respiratory distress is noted, intubation may be required. Studies have shown that recovery usually occurs within six months to one year, although children generally have more favorable outcomes. Deaths are rare with this disease, especially if the disease is treated early on its course. Mortality rates are usually quoted at less than 5 percent. After Guillain-Barré syndrome has been treated, it has been known to recur in approximately 5 percent of cases. A total of 5 to 10 percent of the entire patient population is left with permanent disability. SEE ALSO: Autoimmune Diseases (General). Bibliography. A. K. Asbury and D. R. Cornblath, “As-
sessment of Current Diagnostic Criteria for Guillain-Barré Syndrome,” Annals of Neurology (v.27/Suppl, 1990); J. W. Griffin, et al., “Guillain-Barré Syndrome in Northern China. The Spectrum of Neuropathological Changes in
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Clinically Defined Cases,” Brain (v.118/Pt 3, 1995); R. A. Hughes and R. H. Rees, “Clinical and Epidemiological Features of Guillain-Barré Syndrome,” Journal of Infectious Diseases (v.176, 1997); J. R. Jones, “Childhood Guillain-Barré Syndrome: Clinical Presentation, Diagnosis and Therapy,” Journal of Child Neurology (v.11, 1996); A. H. Ropper, “The Guillain-Barré Syndrome,” New England Journal of Medicine (v.326, 1992). Darrin J. Lee University of California, Irvine
Guinea Guinea is located in western Africa, with a coastline on the Atlantic Ocean. It is sometimes referred to as Guinea-Conakry to differentiate it from the neighboring country of Guinea-Bissau. A former French colony, Guinea won its independence in 1958. Although it managed to avoid being drawn into the civil strife that rocked Sierra Leone and Liberia on its southern borders, political and economic discontent was leading toward demonstrations and general strikes in 2006 and early 2007, and some international observers believe Guinea could soon fall into chaos. Guinea’s population now stands at 9,948,000 and is growing at a rate of 2.62 percent annually. (These population figures do not include several large refugee groups living in camps along the borders.) The birth rate is 41.53 per 1,000 and the death rate is 15.33 per 1,000. Median age is 17.7 years. Life expectancy is 48.5 years for males and 50.84 years for females. Despite ample natural resources, Guinea’s economy is still characterized as “underdeveloped.” Gross national income is a mere $370 per capita. Malaria is the primary cause of morbidity in Guinea. Lassa fever, a viral hemmorhagic disease transmitted through animal waste, is endemic in Guinea; 80 percent of those infected are asymptomatic, but the fatality rate is high for those who become symptomatic. Acute respiratory infections are common, especially in the overcrowded refugee camps. Guinea also suffers from a high burden of yellow fever in some region, along with schistosomiasis, meningococcal meningitis, measles, and cholera. Sanitation is minimal within the country, with about half the population
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able to find clean water, and only 18 percent using adequate waste facilities. Estimates on the HIV/AIDS epidemic vary, but the Joint Programme of the United Nations on HIV/AIDS (UNAIDS) puts the adult prevalence rate at 1.5 percent. This translates to around 85,000 cases, of which 53,000 are women and 7,000 are children under age 15. At present, only 0.4 percent of pregnant women are receiving drugs to help prevent mother-to-child tranmission of the virus, despite the fact that in some areas, 6.5 percent of pregnant women are infected. Health officials have but Guinea on the fast track for improvements in their treatment and educational programs. Child mortality rates have dropped from 1990 levels, but remains high at 98 deaths per 1,000 for infants younger than 1, and 150 deaths per 1,000 for children aged 1–5. AIDS and other diseases have left an orphan population estimated at 370,000. Per capita government expenditures on health were around U.S. $13 in 2001. Medical facilities are spread around the country, often forcing the sick or injured to walk for many miles before finding healthcare. There are few ambulances to transport the seriously ill to district or general hospitals. Facilities around the country are in poor physical condition, and often lack safe water. The large refugee population has strained resources to the breaking point in some regions. Understaffing is also a problem, with 0.9 physicians and 4.7 nurses and midwives per 10,000 population. See Also: Cholera; Healthcare, Africa; Malaria. Bibliography. The Johns Hopkins University Center for
Communications Programs, “Guinea, Country Overview,” www.jhuccp.org/africa/guinea/index.shtml (cited July 2007); World Health Organization, “Guinea,” www.who. int/countries/gin/en/ (cited July 2007). Heather K. Michon Independent Scholar
Guinea-Bissau Guinea-Bissau is a small country on the Atlantic coast of Africa, between Senegal and Guinea. Formerly called Portuguese Guinea, it won independence in 1974 and took its name to differentiate itself from
its southern neighbor, itself a former French colony. Guinea-Bissau is one of the world’s 10 poorest countries. Political turmoil in the late 1990s sparked a brief civil war that in turn caused severe disruptions in the country’s agricultural and fishing industries. The population is 1,473,000 and growing at 2.05 percent annually. The birth rate is 36.81 per 1,000 population, and the death rate is 16.29 per 1,000. Median age is 19 years. Life expectancy is 45.37 years for males and 49.04 years for females. Gross national income is $180 per capita. Only 36 percent of the population lives in urban areas; 62 percent of Guineans work in agriculture. Vectorborne and waterborne diseases are common through Guinea-Bissau. Malaria is likely the chief killer. There is also a high risk of yellow fever, cholera, meningococcal meningitis, schistosomiasis, typhoid, hepatitis A, and diarrhea. Less than 60 percent of the population have access to clean water, and only 35 percent have sanitary waste disposal. Little is known about the dimension of the AIDS epidemic in Guinea-Bissau. In 2003, the adult prevalence rate was estimated at 10 percent, with 17,000 people believed to be infected as of 2001. Guinea-Bissau has abysmal rates for infant and child mortality, with 124 of every 1,000 infants dying between birth and age 1, and 200 deaths per 1,000 for children aged 1–5. In 2005, the United Nations Children’s Fund (UNICEF) estimated the total number of deaths at 16,000 children 5 and younger. A quarter of Guinean children are underweight, 30 percent show signs of stunting, and 10 percent are defined as wasting. Immunization rates run at around 80 percent. Fifty-five percent of children go to work during the school-age years. The health profile for women is similarly grim. The total fertility rate is 4.79 children per women. Only 8 percent of women use birth control. Just 62 percent have prenatal care, and 35 percent have a trained attendant during childbirth. Consequently, Guinea-Bissau has one of the highest maternal mortality rates in the world, with 1,100 women per 100,000 dying in childbirth. The medical system in Guinea-Bissau barely functions. Facilities are understaffed, and staff often goes for long periods without pay. There are 188 physicians, 912 nurses, and 160 midwives working within the country; per capita expenditures on healthcare by the government amounts to $8.70. Hospitals often lack electricity and running water. What equipment
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exists is often antiquated, and most facilities lack the most basic drugs and medical supplies. The necessity for up-front payment for care puts it out of the reach of many Guineans. See also: Cholera; Healthcare, Africa; Malaria. Bibliography. “A Guide to Statistical Information at
WHO”. www.who.int/whosis/en/index.html (cited June 2007); “Guinea-Bissau: Health Service Far From Well”. www.plusnews.org (cited June 2007); United Nations Children’s Fund, “At a Glance: Guinea-Bissau—Statistics”. www. unicef.org (cited June 2007). Heather K. Michon Independent Scholar
Gum Disease Gum disease, also called periodontitis or peridontal disease, is an inflammation of oral tissues caused by bacteria collecting around the base of the teeth. Prolonged inflammation destroys bone and connective fibers and can lead to tooth loss and a host of other health problems. Gum disease affects people throughout the world without regard to region, class, or development. According to the American Academy of Periodontology, there are several types of gum disease. Gingivitis is the mildest form, causing the gums to become red and swollen but causing little discomfort. It is the easiest form of gum disease to reverse. Agressive periodontitis is the next stage, where inflammation has caused loss of tooth attachment and bone loss. Chronic (or severe) periodontitis is the most frequently diagnosed form of gum disease, especially among adults. Bacteria and inflammation causes the formation of pockets around the base of the teeth, or the recession of the gums, along with loss of tooth attachment. Necrotizing periodontal disease is generally seen in those with diseases such as HIV/AIDS or other systemic diseases, or in cases of severe malnutrition. It causes the loss of gingiva and the formation of lesions on gum tissue. While periodontitis has long been viewed as arising from a lack of oral hygiene, there are in fact several other risk factors for the development of the disease. New research indicates that tobacco use may be the
Gum disease is an inflammation of oral tissues caused by bacteria collecting around the base of the teeth.
most significant risk factor in both periodontitis and oral cancers. Genetics may also play a large role, with around 30 percent of the population predisposed to gum problems. In women, hormonal changes around puberty and during pregnancy may spur the development of inflammation. Lifestyle issues like stress, poor nutrition, and the use of some medications are known to reduce the ability of the body to fight off infections. Bruxism, or the involuntary clenching or grinding of the teeth, causes a variety of gum problems, including recession. The ultimate result of untreated, advanced periodontitis is tooth loss, but researchers are now finding that even mild cases of gum disease has an impact far beyond the mouth. Periodontitis is believed to increase the risk of cardiovascular disease, perhaps as a reaction to the presence of bacteria in the bloodstream. It also may increase the risk of certain respiratory diseases. Pregnant women with periodontitis are seven times as likely to give birth prematurely. Some studies indicate that periodontitis can raise the risk of developing diabetes, or it can develop as a result of having diabetes. Most of the global population has some form of gum inflammation, with severe periodontitis affecting five to 15 percent worldwide. The World Health Organization has identified oral health as a major part of overall health and quality of life, and has
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launched a Global Oral Health Programme designed to raise awareness of the issue. Among their goals is increasing availability of dental care in disadvantaged regions and reducing the global consumption of tobacco products. See Also: American Dental Association (ADA); Child
Dental Health; Dental Health.
Bibliography. American Academy of Periodontology
“Frequently Asked Questions About Gum Disease and General Health,” www.perio.org (cited July 2007); “What Is the Burden of Oral Disease?” World Health Organization. www.who.int (cited July 2007); World Health Organization, “World Oral Health Report 2003,” www.who.int (cited July 2007). Heather K. Michon Independent Scholar
Guyana Guyana is located on the eastern coast of South America, bordered by Venezuela, Surinam, and Brazil. It is a small country with a long and complicated history. For two centuries, Guyana was a Dutch colony, but in 1815, it became a British possession; it did not gain independence until 1966. During these years of British rule, there was an influx of immigrants from India. So this small South American country has English as its primary language, and the majority of the population is of East Indian descent. Thirty percent of Guyanese are practicing Hindus. Guyana is about the size of Idaho and has an estimated population of 767,000. The population growth rate only 0.25 percent a year, with 18.28 births per 1,000 people and 8.28 deaths per 1,000 people. The migration rate is deeply in the negative column at minus 7.49 migrants per 1,000 people. Eighty percent of Guyana is covered by tropical rainforest. Most of the population lives in urbanized coastal areas. The climate is hot and humid, with some relief coming from the northeast trade winds. Winter is the rainy season, and flash flooding is common. In recent years, the government has opened the rainforest to Malaysian logging interests and palm oil
producers, which environmentalists warn could devastate local ecosystems. However, with per capita income for most Guyanese at $990 annually, the government has little choice but to woo foreign investors. The national economy has long depended on agricultural imports such as sugar, rice, molasses, and shrimp, along with gold and bauxite mining, but it is not profitable enough to improve the daily lives of the citizens. The Guyanese manage to get by on very little. Their average caloric intake is 2,450 per day, which is actually above the recommended averages. Staple foods are peas, rice, bread, and starchy vegetables such as plantain, cassava, and breadfruit. The calories are more than adequate, but malnutrition is still a problem, as this diet lacks key vitamins and protein. Life expectancy at birth is 63.21 for males and 68.65 for females; healthy life expectancy is 53.1 for men and 57.2 for women. Infant mortality is 32 deaths per 1,000 live births and 64 children in 1,000 die between the ages of 1 to 5 years. Maternal mortality is 170 deaths per 100,000 live births. Eighty-six percent of births are monitored by a trained attendant. About 37 percent of women have access to birth control. Like most of Latin America, there is a high rate of parasitic infections. About 83 percent of the population has access to clean drinking water and 70 percent can access sanitary facilities. Malaria, typhoid fever, and filariasis are common. Measles remains a problem. Immunization rates for children average about 90 percent for all major childhood diseases, and the country maintains an active malaria-eradication program. Communicable diseases are closely monitored, and the country has not suffered a major epidemic in several years. The HIV/AIDS rate is 2.5 percent, with an estimated 11,000 Guyanese living with the virus. More than 1,100 have died so far. Tuberculosis rates are also high. The Ministry of Health has launched an AIDS awareness program and has 14 treatment sites scattered throughout the country. Many AIDS patients are now receiving life-extending drug treatments, but it remains a struggle for the government to provide the recommended three-drug cocktail. In 2006, Health Minister Leslie Ramsammy announced that the government could not yet afford the new one-pill daily protocol, at a cost of $1,000 per patient per month.
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Basic healthcare is available throughout most of Guyana, with four regional hospitals, 22 district hospitals, 70 health centers, 32 health posts, and one psychiatric hospital. Ambulance service to more advanced care at the regional hospitals is spotty. There are 366 doctors and 1,738 nurses, leaving facilities frequently understaffed. SEE ALSO: Healthcare, South America.
Pan American Health Organization (PAHO) and World Health Organization (WHO), “Health Sector Analysis: Guyana,” www.lachealthsys.org (cited July 2007); World Health Organization, “Guyana,” http://www. who.int/countries/guy/en/ (cited July 2007). Bibliography.
Heather K. Michon Independent Scholar
Gynecologist A gynecologist is a medical doctor who specializes in the health and diseases of women’s reproductive organs. While medical training is broad and exposes a future physician to a wide array of medical problems and treatments, gynecologists have chosen to pursue a four-year residency in obstetrics and gynecology in order to train in the specialty of women’s reproductive health. Unlike most medical specialties, the practice of gynecology represents a blend of both medical and surgical skills making the gynecologist both a physician and a surgeon. They typically see female patients of all ages and are equipped to deal with a wide variety of reproductive health and basic medical issues. A gynecologist is an important caregiver in the context of global health because of the relevance of elevated maternal mortality rates, increasing prevalence of AIDS and other sexually transmitted infections among women, lack of screening for cervical cancer, and gender-based violence in the developing world. While all patients who visit gynecologists are female, their ages can range from the prepubescent to the elderly. Young females are often medically treated by a pediatrician or family physician into their teenage years, and most females generally begin to see a gynecologist around age 18 or once they have become
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sexually active. However, there is plenty of variation within this scheme. Many women begin to see gynecologists at age 18 for a Pap smear. The Pap smear is a screening test for cervical cancer and current guidelines indicate that women should begin to receive Pap smears at age 18 or the onset of sexual activity. Once initiated into the care of the gynecologist, most women continue to see one throughout their reproductive years, through menopause, and into the postmenopausal years when different types of problems can occur. Women seeking care from gynecologists require services ranging from prescriptions for oral contraceptive pills, to Pap smears, to assessment and treatment of abnormal vaginal bleeding, to lower abdominal or pelvic pain, to sexually transmitted infections, to urinary incontinence, to vulvar, vaginal, cervical, endometrial, or ovarian cancer. Gynecologists also need to tend to the mental and social health needs of their patients by screening them for depression, substance abuse, or gender-based violence. In addition, many women utilize their gynecologist as their primary health provider which means that these physicians are also evaluating their patient’s general medical health. A woman’s reproductive tract includes her ovaries, fallopian tubes, uterus, cervix, vagina, vulva, and breasts. It is worth noting that most breast surgery (for biopsy or excision of cancerous tissue) is done by gen-
A gynecologist is a medical doctor who specializes in the health and diseases of women’s reproductive organs.
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eral surgeons who specialize in surgery of the breast. However, there are a growing number of gynecologists, often gynecologic oncologists, who pursue fellowship training in breast surgery and are qualified to offer this service to their patients. The remaining reproductive organs located in the pelvis are the main focus of the gynecologist. There are a wide range of diseases or other problems that can affect these organs. Training to become a gynecologist is a lengthy process. First, she/he must complete four years of medical school and then complete four years of residency in obstetrics and gynecology. All residency programs that prepare medical school graduates to practice in this field train residents in both obstetrics and gynecology. It is up to the individual physician to chose whether she/he goes on to practice both obstetrics and gynecology or focus solely on gynecology upon completion of the program. Many obstetricians/gynecologists go on to pursue fellowship training. This means that they choose to further specialize in one area of gynecology and spend an additional one to three years honing their skills. Examples of fellowships that gynecologists pursue include gynecologic oncology, urogynecology, reproductive endocrinology and infertility, and family planning. There are other fellowships that pertain more directly to the practice of obstetrics such as maternal-fetal medicine. SEE ALSO: Gynecology; Obstetrician/Gynecologist; Ob-
stetrics.
Bibliography. P. R. Bennett and G. E. Moore, Molecu-
lar Biology for Obstetricians and Gynecologists (Blackwell, 1991); Duane E. Townsend, Maverick of Medicine Speaks to Women: A World-Renowned Gynecologist’s Solutions for a Better World in Women’s Health Care (Woodland Publishing, 2003). Megan K. Guffey, M.D., M.P.H. Independent Scholar
Gynecology Gynecology (alternately, gynaecology) is the branch of medicine that deals with the female reproductive organs. It is closely related to the field of obstetrics,
which is involved with the care of women and fetuses during pregnancy. OB/GYN is a common medical specialty. Gynecological problems are rare in preadolescence except in cases of birth defects or conditions precipitated by sexual abuse. The onset of menstruation, which generally occurs around the age of 12, marks the beginning of puberty. Even in cases where physical abnormalities are present, they may not surface before puberty. Dysmenorrhea (painful menstruation), for instance, may be either primary or secondary to pelvic disease. Around 50 percent of all women of childbearing age experience dysmenorrhea to some extent, but it is severe in only one in 10. Incidences of the disorder tend to decline after the age of 24 and may disappear earlier in women who become pregnant. In some women, amenorrhea, the absence of menstruation, is experienced without a clear physical cause. In most cases, it is associated with autoimmune or infectious diseases or cancer treatments. It may also occur in female athletes and in females with eating disorders. It is estimated that 95 percent of all premenopausal women experience Premenstrual Syndrome (PMS), occurring seven to 10 days before the beginning of the menstrual cycle. Symptoms tend to disappear once bleeding starts. Experiences with PMS vary greatly. Common symptoms include facial acne, breast swelling and tenderness, fatigue, insomnia, gastrointestinal problems, bloating, constipation, diarrhea, headache, backache, appetite variations, joint or muscle pain, and concentration and memory difficulties. Caused by fluctuating hormone levels, the classic symptom of PMS is wide mood swings involving tension, irritability, crying jags, anxiety, or depression. While there is no specific treatment for PMS, pain medication, vitamin B6, oil of evening primrose, and serotonin inhibitors offer relief to some women. In some cultures and religions, the most pressing gynecological problem is female genital mutilation (FGM), also known as female circumcision. The purported purposes of altering a girl’s external sexual organs are to prolong virginity and enhance marriageability. Performed in Africa, the Middle East, and in Muslim areas of Indonesia and Malaysia without anesthesia, FGM poses major health risks for females. Because the procedure is also performed among immigrant populations in Western countries, many nations have passed laws to make the practice illegal.
However, physicians are encouraged to show compassion in dealing with women who have undergone FGM. In 1995, the landmark Beijing Conference on women’s rights condemned the practice as a violation of human rights. Throughout the world, sexually transmitted diseases (STDs) continue to present major difficulties for the medical community, society, and governments. Health clinics are established to screen for STDs and to provide treatment and follow-up. Once diagnosed, all sexual partners of infected persons must be notified in order to prevent individual health problems and the spreading of the disease. Even women who have had sex with only one partner may be vulnerable to infection if that partner has practiced unsafe sex or had sex with multiple partners. The human papillomavirus (HPV) is the most prevalent of all STDs, and around 70 strains of the virus have so far been identified. In many developing nations, HIV/AIDS has become the most pressing gynecological problem for both women and for the children they deliver because of the risk of mother-to-child transmissions during the birthing process. Gynecological disorders Infections may occur in all parts of the reproductive system for a variety of reasons. Visits to gynecologists are often made in response to unexplained pelvic pain. One of the most common sources of pelvic pain is fibroids, noncancerous growths that take root in the smooth muscle layer of the uterus. Fibroids occur in from 30 to 50 percent of all women over the age of 30. They tend to occur earlier in African Americans. While fibroids may be asymptomatic, they are often associated with menstrual abnormalities and changes in menstrual patterns. Behaviors linked to the formation of fibroids include being physically inactive and consumption of alcohol and caffeine. Some physicians believe that taking vitamin B6 and eating more fiber may reduce the risk. Adenomyosis, a disorder in which endometrium tissues grow outside the walls of the uterus, is also common, occurring at a rate of 10 to 90 percent of all women over the age of 50. Both fibroids and adenomyosis may improve after menopause as estrogen levels decrease. As a general rule, germ cell tumors are most common in younger women, and epithelial growths are associated with older women. Half of all tumors found in older women are benign.
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Postmenopausal women, particularly those over the age of 60, may experience a prolapsed uterus, a condition in which the uterus partially descends into the vagina in response to the weakening of pelvic floor muscles. A prolapsed uterus may also result from a difficult labor, having a large baby, multiple pregnancies, obesity, chronic constipation, fibroids, or pelvic tumors. Symptoms include heaviness or pressure in the vagina, incontinence, backaches, painful or difficult intercourse, and constipation. Mild cases may be treated with hormone therapy and lifestyle changes. Kegel exercises that involve tightening the vaginal and uterine muscles may also offer some relief. In the most severe cases, surgical repositioning of the uterus is necessary. Early in pregnancy, women who experience severe abdominal pain on one side, spotting, vaginal bleeding, nausea, vomiting, fainting and dizziness may be experiencing an ectopic or tubal pregnancy in which a fertilized egg has implanted outside the uterus, usually in the fallopian tubes. If not treated promptly, the condition may lead to rupture, hemorrhage, and infection. Nine percent of all pregnancy-related deaths in the United States are a result of ectopic pregnancies. Risk for ectopic pregnancies include pelvic inflammatory disease or endometriosis, being over the age of 30, a history of ectopic pregnancies, smoking, and past surgeries of the abdomen or fallopian tubes. Endometriosis involves the depositing of tissues that normally line the womb outside the uterus. The condition occurs in three to seven percent of all women, but it may be more prevalent because of underreporting. Endometriosis normally peaks between the ages of 30 and 45 years. Symptoms include pain, menstrual disturbance, and infertility, and treatment may include medication or surgery. Gestational trophoblastic tumors, also referred to as “molar pregnancies,” involve the growth of moles that occur after abnormal fertilization. They may be either benign or cancerous. Researchers have not been able to establish a clear link between race and these cancers, but they are more common in some Asian countries, leading to the assumption that they may be related to diet. These tumors are 10 times more common in women over the age of 45. Warning signs include uterine bleeding, severe nausea, and vomiting. In general, such pregnancies resolve after uterine evacuation. In 10 to 20 percent of all case, moles transform into malignancies; but there is a cure rate of 90 to 95 percent.
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Gynecological cancers The most common cancers in women are breast, cervical, uterus, and ovary. Breast cancer is the second leading cause of death in the United States. Endometrial cancer is the most common gynecological cancer found in American women. Out of 37,000 cases diagnosed each year, the cancer is fatal in 3,000 to 4,000 women. It may strike at any age, but three-fourths of endometrial cancers occur after the age of 50. Warning signs are postmenopausal bleeding, and estrogen and obesity are established links. The condition known as polycystic ovarian syndrome (PCOS) involves a functional derangement of the hypothalamo-pituitary ovarian axis. PCOS may be genetic. Risk factors include obesity, abnormal menstrual disorders, hirsutism, acne, and infertility. Women with PCOS have three times the risk of developing endometrial cancer and are at increased risk for developing diabetes, hypertension, and cardiovascular disease. Growths in the vulva may be either benign or malignant, but vulva cancer is generally considered curable. The cancer is most common in women between the ages of 60 and 79; fewer than 15 percent occur in women under 40. Risk factors include a past history of the human papillomavirus or cancer and smoking. Eighty percent of cervical cancers are squamous in origin and were once assumed to have an ethnic risk factor. Incidences are rising among young white women and declining among black women. Accepted risk factors include a past history of HPV, smoking, alcohol abuse, early onset of sexual activity, marriage or conception at an early age, and multiple sex partners. Many women with these risk factors will not get cervical cancer, while women who have had only one sexual partner may contract the disease. Warning signs include bleeding or spotting after intercourse and bloody discharge. In the early stages, pain is rarely a factor. Cervical cancer is treated with surgery and radiation. Early in the 21st century, a vaccine to protect girls against cervical cancer was released. Despite the move for universal vaccinate of the relevant age group, the vaccine remains controversial. Ovarian neoplasms may result from normal changes to existing malignancies. Risk factors for ovarian cancer include early menstruation, late menopause, and never having had children. Symptoms of ovarian cancer are acute pelvic pain and hemorrhage. Women who have used oral contraceptives are at a reduced risk for ovarian cancer,
as are those who have had early pregnancies or several children. In the past, dilation and curettage (D&C) in which the lining of the uterus was scraped was used as both a diagnostic and surgical tool. However, new and less invasive technologies such as laparoscopy have become more common. The most common gynecological procedure performed is the hysterectomy, which involves surgical removal of the uterus. In 40 percent of all cases, one or both ovaries are removed, in part to remove the risk of developing ovarian cancer. Estimates suggest that without ovarian removal, one in every 700 women who undergo hysterectomies would have later developed ovarian cancer. After hysterectomies are performed, women abruptly enter menopause, a cessation of the menses that signals the end of fertility. Women who undergo menopause, before the age of 40 are said to experience premature ovarian failure. Before the scare over the link between breast cancer and hormone replacement therapy (HRT), estrogen and progesterone therapies were routinely prescribed for women after hysterectomies. The new findings have caused many women to look for alternative therapies. Early detection of gynecological cancers through self-examinations, mammograms, and Pap smears is a key factor in survival rates. Preventive care is similar to that of other cancers and involves controlling hypertension and cholesterol, not smoking, healthy eating habits, being physically active, using birth control, practicing safe sex, and managing stress. Contraception and infertility Most women of childbearing age are sexually active, and studies show that approximately one-half of all American women between the ages of 15 and 19 have had sexual intercourse. Large numbers of sexually active women do not use any form of birth control to prevent unwanted pregnancies or the transmission of STDs. Teenage pregnancies are a major problem in many countries throughout the world, and they present major health risks because they pose greater health risks to both mother and child and place onerous burdens on social service systems. Humans have practiced birth control throughout much of history. The most common method, which was used in biblical times, was coitus interuptus in
which the male withdraws from the female before climax to prevent the release of sperm. Natural forms of birth control, including the rhythm method, which estimates fertility by charting menstrual cycles, are still in use today. Since the women’s movement of the 1960s, research into contraception has produced a variety of birth control technologies, including spermacides, condoms, diaphragms, intrauterine devices, and the highly effective birth control pill. Common surgical contraception methods include tubal ligations in females and vasectomies in males. In both cases, the intent is to prevent the female’s eggs from being fertilized by sperm. In many societies, abortion remains the most controversial method of birth control. It is generally controlled by strict guidelines that serves the dual purpose of protecting the health of the mother and serving the interest of those who object to abortion on either religious or moral grounds. Abortions that occur spontaneously are called miscarriages, and those performed for health reasons are considered therapeutic. Approximately one in six couples are said to be infertile, but only 42 percent of infertile women seek professional help. The classification of infertility is made only after a couple fails to conceive after a year of unprotected intercourse. In about 40 percent of all cases, the male is either the sole or a contributing cause of infertility. In females, the most common causes of infertility are abnormalities or diseases of the fallopian tubes, ovulation disorders, cervical abnormalities, uterine failure, chronic infections, debilitating diseases, severe nutritional deficiencies, and advancing age. Modern medicine has provided
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a plethora of alternatives to traditional pregnancies that include artificial insemination from a partner or donor’s sperm, in vitro fertilization, fertility drugs, embryo transfer from a donor, and surrogacy. See also: Abortions; Adolescent Health; AIDS; Birth
Defects; Breast Cancer; Diabetes; Gastroenterology; Hormones; Hypertension; In vitro; Infectious Diseases (General); Infertility; Menopause; Obesity; Obstetrician/Gynecologist; Obstetrics; Preventive Care; Pregnancy; Sexually Transmitted Diseases (STDs); Women’s Health (General). Bibliography. Phyllis L. Carr, et al., The Medical Care of Women (Saunders, 1995); Allen H. DeCherney, and Martin L. Pernoll, eds., Current Obstetric and Gynecologic Diagnosis and Treatment (Appleton and Lange, 1994); Valerie Edge, and Mindi Miller, Women’s Health Care (Mosby, 1994); Stephen S. Entman, and Charles B. Rush, eds., Office Gynecology (W.B. Saunders, 1995); Neville F. Hacker, and J. George Moore, eds., Essentials of Obstetrics and Gynecology (Saunders, 1998); Norman E. Himes, Medical History of Contraception (Schocken Books, 1970); John H. Mattox, eds, Obstetrics and Gynecology (Mosby, 1998); David McKay and Jane Norman, Gynaecology Illustrated (Churchill Livingstone, 2000); Angus McLauren, A History of Contraceptives: From Antiquity to the Present Day (Basil Blackwell, 1991); Ann McPherson, ed., Women’s Problems in General Practice (Oxford University Press, 1993); Manuel Penalver, et al., eds., Gynecologic Oncology (Saunders, 2001).
Elizabeth R. Purdy, Ph.D. Independent Scholar
H Hair Diseases and Hair Loss Hair grows from hair follicles located in the layer of skin called dermis, lying immediately below the surface layer. The dermis all over the body contains hair follicles except for lips, palms of hands, and soles of feet. Hair color originates from a pigment called melanin, which also gives skin its color. Hair grows in cycles of growth consisting of a long growing phase followed by a short resting phase. Human hair growth is regulated by hormones like testosterone and dihydrotestosterone, which are present in both the sexes. These hormones influence hair growth in the underarms and pubic area. Beard hair grows due to stimulation from dihydrotestosterone. Hair disorders include hair loss, excessive hairiness (hirsutism), and ingrown beard hair. These disorders may be caused by physical causes or abnormal hormone secretion. Hair diseases may not be life threatening, but may be a cosmetics issue. Some common diseases are below: Alopecia Areata. This autoimmune disease results in patches of hair loss over the head. These patches may remain for years or may go away. This disease is caused when the immune system attacks hair follicles causing hair loss. Folliculitis. Folliculitis is a bacterial infection of hair follicles caused by Staphylococcus aureus. Follicles may
swell into a red bumps or pimples. The infection may also spread causing swelling, redness, pain, severe tenderness, and production of pus from the infected site. Hirsutism. Hirsutism is abnormal hair growth in women, particularly in the face, chest, and areolae. Hirsutism is caused by excessive levels of the hormone androgen and/or high sensitivity of hair follicles to androgen. This disorder may be caused by abnormalities in adrenal glands or ovaries. Keratosis Pilaris. Keratosis pilaris is caused when skin cells—that usually flake off—plug hair follicles causing small painless pimples. Keratosis pilaris is common in teenagers on the upper arms, and babies on their cheeks. There is no tested treatment for keratosis pilaris, which worsens during winter months and humid days, but generally disappears before age 30. Poliosis. Poliosis is abnormal whitening of hair in small patches that can occur anywhere on the body; on the forehead, it is called a white forelock. Poliosis occurs when hair coloring pigment melanin runs out causing hair discoloration. Poliosis also occurs due to genetic diseases like piebaldism. Most poliosis cases occur in otherwise healthy individuals. Hair loss. Hair loss is the gradual loss of hair with age seen in both the sexes, but more commonly in men. Hair loss may be caused by diseases, improper hair care, and genetics. Improper treatment of hair with
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chemicals like dyes, tints, straighteners, bleaches, and permanent waves can cause hair loss if these chemicals are used improperly or excessively. Other causes include shampooing, combing or brushing more often than necessary, and vigorously rubbing wet hair with a towel. The most common cause of hair loss is by genetics—a condition called androgenetic alopecia—resulting in hereditary balding or thinning of hair. Hereditary balding is most obvious around the temples and crown in men, and on top of the head in women. Androgenetic alopecia may be treated with minoxidilcontaining products which cause vasodilatation in hair follicles promoting hair growth. See ALSO: Hair Dye; Head Lice; Hormone Replacement
Therapy; Hormones.
Bibliography. Rodney Dawber, Diseases of the Hair
and Scalp (Blackwell Publishing, 1997); Benjamin Godfrey, Diseases of Hair (Churchill, 1872); Jerry Shapiro, Hair Loss: Principles of Diagnosis and Management of Alopecia (Taylor & Francis, 2002); Leonard Sperling, An Atlas of Hair Pathology with Clinical Correlations (Taylor & Francis, 2003).
Rahul Gladwin, M.D. University of Health Sciences Antigua
Hair loss is the gradual loss of hair with age; it is seen in both the sexes, but is more common in men.
Hair Dye Hair coloring products include a wide range of over 5,000 chemical substances, some of which have been reported to be mutagenic and carcinogenic to animals. Hair dye products may be divided into three categories, that is, permanent, semipermanent, and temporary hair colors. Permanent hair colors are the most popular hair dye products. They may be further divided into oxidation hair dyes and progressive hair dyes. Oxidation hair dye products consist of 1.) a solution of dye intermediates, which form hair dyes on chemical reaction, and preformed dyes, which already are dyes and are added to achieve the intended shades, in an aqueous, ammoniacal vehicle containing soap, detergents, and conditioning agents; and 2.) a solution of hydrogen peroxide, usually 6 percent in water. The prevalence of use of hair dyes is high among women in industrialized countries with more than half of women above age 18 applying hair dyes in Europe and the United States and around 10 percent among males. Consumers use all major types of hair colorants, which may contain aromatic amines, nitro-substituted aromatic amines, high molecular weight complexes, metal salts, and other. The content of hair dye has changed over the years and recent legislation prevents the use of carcinogenic substances in hair dye use. Some components of hair dyes may cause skin irritation on certain individuals and a preliminary test according to accompanying directions should first be made as it is generally advised by the manufacturers. A major concern on the health effects of hair dyes is, however, the suspicion that they may be linked to cancer. While no clear excess risk of cancer has been observed among hairdressers and barbers, the evaluation of cancer risk among regular users of hair dyes has been poorly evaluated due to lack of adequate data on humans. In 1992, the International Agency for Research on Cancer evaluated hairdressing and barbering as occupations entailing exposures that are probably carcinogenic to humans; personal use of hair colorants could not at that time be evaluated in terms of its carcinogenicity. Since this last evaluation, several studies have tried to provide human data on regular use of hair dyes. Among the cancer sites that have been most commonly evaluated in association with regular exposure to hair dyes are bladder cancer and lymphomas. Small amounts of
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Bibliography. International Agency for Research on Cancer, Occupational Exposures of Hairdressers and Barbers and Personal Use of Hair Colourants; Some Hair Dyes, Cosmetic Colourants, Industrial Dyestuffs and Aromatic Amines (International Agency for Research on Cancer, 1993); S. de Sanjose, et al., “Association between Personal Use of Hair Dyes and Lymphoid Neoplasms in Europe,” American Journal of Epidemiology (v.164/1, 2006); B. Takkouche, M. Etminan, and A. Montes-Martínez, “Personal Use of Hair Dyes and Risk of Cancer. A Meta-Analysis,” Journal of the American Medical Association (v.293, 2005).
Silvia de Sanjose, M.D., Ph.D. Catalan Institute of Oncology More than half of women in Europe and the United States above the age of 18 use hair dye products.
the bladder carcinogen 4-aminobiphenyl (4-ABP), an aromatic amine, in eight out of the 11 hair dyes tested have been identified. Although an excess risk has been seen in some studies that included information on personal use of permanent hair dyes and bladder cancer risk, the overall results are not yet converging. Use of hair dyes has been inconsistently associated to the etiology of lymphomas. Recently, Yawei Zhang from Connecticut and Silvia de Sanjose reporting from six European countries have shown that the risk of certain types of lymphomas may increase between 20 to 30 percent among regular users of hair dyes. In both studies, the risk was increased mainly among those women using hair dyes before 1980, but no clear association among those using hair dyes during the last 20 years. This observation suggests that more recent hair dyes may have a safe composition. Further, the evaluation of all available studies in humans estimated a 15 percent increased risk for hematopoietic cancer, 23 percent for Hodgkin’s lymphoma, and a 1 percent increased risk for bladder cancer. New rules are implemented by the European Community Directive on the safe use of ingredients in hair dyes. Twenty-two substances have been added to the list of banned ingredients identified as being potentially carcinogenic. SEE ALSO: Cancer (General).
Haiti Haiti is located on the western third of the island of Hispaniola, with the Dominican Republic next door. Plagued by violence and political upheaval throughout its long history, Haiti today has no end to its problems, and it is easily the poorest nation in the western hemisphere. Assaults on the health and welfare for Haitians come from all directions. The population is 8.3 million (2006 estimate), with a growth rate of 2.3 percent annually. The birth rate is 36.44 per 1,000 people and the death rate at 12.17 per 1,000 people. The migration rate is negative, with minus 1.31 migrants per 1,000. Haiti has virtually no economy and few exports other than people heading for a better life elsewhere. An estimated 70 percent of the population are unemployed. Per capita income is $390 a year. Most food is imported, and therefore expensive, so the average Haitian lives on subsistence diet of 800 calories a day, based on corn, cassava, millet, rice, fruit, beans, goat, pork, and shellfish. There is a shortage of potable water. Access to clean water is 71 percent, but access to sanitary facilities is only 34 percent, even in the urban areas. Massive deforestation in the mountains along the border with the Dominican Republic has left the country vulnerable to storm flooding, mud slides, and soil erosion. Life expectancy at birth is 51.89 years for males and 54.6 years for female, with healthy life expectancy 43.5 years for men and 44.1 years for women. Infant mortality is high, with 102 of every 1,000 infants dying before the age of 1, and 117 of every 1,000 children dying
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before the age of 5. Maternal mortality is equally high, with 1,000 deaths per 100,000 live births. Only 24 percent of births are monitored by trained attendants. Seventy-eight percent of women receive at least some prenatal care. Only 27 percent have access to birth control. The rates of HIV/AIDS are among the highest in the hemisphere, with 5.6 percent of the population, or 280,000 people, already infected with the virus. At least 24,000 Haitians have already died of AIDS. Haiti also has the highest per capita incidence of tuberculosis in Latin America. Tuberculosis alone kills 6,000 Haitians each year. The tropical climate, poor nutrition, and virtually nonexistent sanitation makes Haiti an excellent breeding ground for a wide variety of diseases, including diarrhea, malaria, typhus, rabies, anthrax, Q fever, brucellosis, hookworm, roundworm, schistosomiasis, and leptospirosis. Diabetes, arising from an unbalanced and nutrition-poor diet, is another growing health problem. In 2000, the World Health Organization tallied 161,000 cases of diabetes in Haiti; by 2030, it expects this number to grow to 401,000. �������������������� Rates of child immunization are very low, with only 43 percent of children protected against diphtheria, pertussis, tetanus, and polio, and only 54 percent receiving measles vaccination. The AIDS and tuberculosis epidemics have created a generation of orphaned children, who become easy prey for child traffickers. Most schools are closed due to ongoing political violence, with only 50 percent of school-aged children enrolled in programs, and less than 2 percent finishing secondary school. Sixty percent of the population lack access to basic healthcare. There are 49 hospitals, 217 health centers, and 371 health posts, most of them poorly staffed and poorly equipped. Well over half the population cannot obtain needed medicines. In 1998, the last year for which the World Health Organization has statistics, there were only 1,949 doctors and 834 nurses to serve the entire population. SEE ALSO: Healthcare, South America. Bibliography. Central Intelligence Agency, “The World
Factbook: Haiti,” www.cia.gov (cited July 2007); World Health Organization, “Haiti,” www.who.int cited July 2007). Heather K. Michon Independent Scholar
Hand Injuries and Disorders Injuries and disorders of the hand can often cause a person to change his or her entire lifestyle. As time progresses, the human race tends to be increasingly dependent upon their hands for fine coordinated movements, such as typing and dialing numbers on miniature phones. With this dependency upon hands and fingers to maximize technological capability, new hand injuries are emerging, and the existing ones are becoming that much more debilitating. Additionally, because acute hand injury is the leading cause of occupational injury treated in U. S. hospital emergency departments, it is imperative that risk factors for traumatic hand injury are identified and dealt with properly by employers. Carpal Tunnel Syndrome The carpal tunnel is a passageway of bones and ligament found at the base of the hand that is sometimes narrowed if swelling occurs. Specifically, carpal tunnel syndrome is caused by compression in the median nerve in the wrist. This may result in pain or a numbness that can extend all the way up the entire length of the arm. Initial symptoms include sensations of itching, burning, and numbness in the fingers and palm of the hand. If untreated, the patient may loose ability to strongly grasp objects or even distinguish between hot and cold by touch. Females are more at risk for developing carpal tunnel syndrome than males. Carpal tunnel syndrome is diagnosed with a physical examination for swelling in the wrists and atrophy of the muscles at the base of the hand. Ultrasound and different electrodiagnostic tests can also be used to diagnose carpal tunnel syndrome. Nonsurgical treatments of carpal tunnel syndrome include prescription medication, exercise, and acupuncture. Surgical treatments include open release surgery and endoscopy. Ganglion Cysts Ganglion cysts are one of the most common types of hand disorders. Ganglion cysts are a swelling due to accumulation of fluid in the back of the hand or wrists. The condition can be frightening as many may wonder if the fluid-filled capsule is cancer. Ganglion cysts are not cancerous, although they may grow as time progresses. While it is unknown what causes the formation of a ganglion, it is known that females
Acute hand injury is the leading cause of occupational injury treated in U. S. hospital emergency departments.
are more likely to be afflicted than males. Depending upon the location of a ganglion cyst, a patient may complain of pain if the ganglion puts pressure upon nerves. To diagnose ganglions, physicians often order X-rays so that conditions such as bone tumors or arthritis can be ruled out. Additionally, if the ganglion is deep under the skin, a magnet resonance imaging (MRI) or ultrasound may also be ordered. Nonsurgical treatment of cysts include immobilization because activity may sometimes worsen symptoms and aspiration of the ganglion with a needle. Nonsurgical treatment of a cyst does not guarantee that the cyst will not return. In surgical treatment of a cyst, the entire ganglion (cyst and outer sac) is removed. Trigger Finger Trigger finger is a common hand problem that causes snapping and catching of the fingers as a patient tries to straighten his or her finger. Diagnosis of trigger finger usually includes patient description of symptoms; X-rays and other tests are usually not needed. Trigger finger is common in individuals aged 40–60 and those who are also afflicted by other diseases such as diabetes and rheumatoid arthritis. If catching or popping symptoms are mild, over-the-counter pain medications or resting the finger may be enough to relieve symptoms. Other treatment options include surgery to widen the tunnel in which the finger is getting caught. However, because trigger finger is not a progressive disorder, surgery is only recommended for patients with more severe symptoms.
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Finger Fracture While fractures of the finger are normally considered minor traumas, if untreated, they can cause major problems in an individual’s manual dexterity. Finger fractures are most common among athletes and can be identified if the following symptoms persist: swelling, inability to move finger, deformity, and pain when the finger is straight and taps against a surface. Most finger fractures are healed by using a splint to put the broken bone back into place. Often, the fingers adjacent to the fractured ones are used for support. Typically, a splint is worn anywhere from three to six weeks after injury. Tendonitis of the Wrist Also known as De Quervain’s stenosing tenosynovitis, tendonitis of the wrist occurs when the tendons of the thumb inflame, causing pain and irritation. Occasionally, a lump or thickening can be felt at the base of the hand. It is unknown what causes this inflammation, although overuse is suspected to play a role. The primary symptom of this form of tendonitis is a general sensation of pain over the thumb-side of the hand. Antiinflammatory medication is usually the first course of action. However, if medication is ineffective, surgery may be the only effective option. Osteoarthritis of the Hand Osteoarthritis of the hand occurs when the cartilage of the joints in the hand begin to undergo wear and tear due to daily use or traumatic injury and eventually wear out. Osteoarthritis of the hand typically occurs in three locations: at the base of the thumb, at the end joint closest to the finger tip, and at the middle joint of a finger. Swelling, pain, stiffness, and generally diminished grip and pinch strength are all typical symptoms of arthritis of the hand. Nonsurgical treatment includes medication, resting the fingers and hand, heating pads, splints for overnight use, and cortisone injections. Dupuytren’s Disease Dupuytren’s disease is an abnormal thickening of the tissue just beneath the superficial skin of the palm. Initial symptoms often include firm lumps in the palm of the hand, causing fingers to slightly bend. The disease may be noticed when an individual has difficulty shaking hands, placing his or her hand on a flat surface such
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as a tabletop, and putting his or her hands in his or her pockets. Observation and surgery are the only two treatment methods used for Dupuytren’s disease. Last, one of the common problems that arises with hands, because they are exposed to so many different surfaces, is different types of hand infections. These include Paronychia, Felon, Herpetic Whitlow, osteomyelitis, tendon sheath infections, and mycobacterial infections. Treatment for these different infections vary. SEE ALSO: Carpal Tunnel Syndrome; Fractures; Osteoar-
thritis.
Bibliography. G.M. Alberton, et al., “Extensor Trigger-
ing in de Quervain’s Stenosing Tenosynovitis,” Journal of Hand Surgery (v.24, 1999); M. Chammas, et al., “Dupuytren’s Disease, Carpal Tunnel Syndrome, Trigger Finger, and Diabetes Mellitus,” ANZ Journal of Surgery (June 2006); R.P. Hertz and E.A. Emmett, “Risk Factors for Occupational Hand Injury,” Journal of Occupational Medicine (v.28, 1986); M.C. de Krom, et al., “Carpal Tunnel Syndrome: Prevalence in the General Population,” Journal of Clinical Epidemiology (v. 282/2, 1992). Mala Gurbani University of Southern California
Haploid For organisms, such as humans, which carry two copies of each chromosome in somatic (nonreproductive) cells, a haploid cell is one that has only one of each chromosome. The haploid number, N, is the number of chromosomes in a haploid cell. For humans, with 23 pairs of chromosomes in somatic cells, germ cells (sperm and eggs) are haploid cells with 23 unpaired chromosomes each. The haploid origin of a chromosome is used by scientists to match samples of DNA to individuals in a variety of settings. Given that a normal human typically has two alleles of each gene (one on each chromosome), it follows that at any given locus only one of the two alleles is represented in a given germ cell. Thus, we might imagine that each locus would determine
two haploid germ cells. As reproduction requires the combination of germ cells from two different individuals, human reproduction represents the opportunity for up to four distinct combinations of haploid germ cells. Once the particular combination of haploid cells is determined during fertilization, though, the maternal or paternal haploid origin of each chromosome will not, except in the case of a select few diseases such as Angelman and Prader-Willi syndromes—the uniparental disomies—be significant in the expression of genes. The relationship between particular loci and their haploid origin is not entirely without value, however. If individual chromosomes, or portions thereof, are sequenced, a genotype for a DNA sequence that came from a single parent can be identified: a haplotype. Shared haplotypes are indicative of relatedness. By comparing haplotypes of sufficient length or haplotypes that are sufficiently rare, it is possible to determine if two individuals share a common ancestor. SEE ALSO: Base Sequence; Crossing Over. Bibliography. Mark Kirkpatrick, ed., Evolution of Hap-
loid-Diploid Life Cycles: 1993 Symposium on Some Mathematical Questions in Biology (American Mathematical Society, 1993); R.L. Nussbaum, et al., Thompson & Thompson: Genetics in Medicine, 6th ed., revised reprint (Saunders, 2004). Bimal P. Chaudhari Boston University
Hardy, James D. (1918–2003) James D. Hardy was an American surgeon who pioneered transplant operations with three landmark cases: the first human lung transplant in 1963; the first animal-to-human heart transplant in 1964, which caused a heated debate on its ethical and moral consequences; and a double-lung transplant leaving the heart in place in 1987. Hardy was born on May 14, 1918, the son of a lime plant owner. He grew up in Alabama where he started his premedical studies at the University
Hardy-Weinberg Law
of Alabama. As that university only had two-year medical programs, Hardy transferred to the University of Pennsylvania where he received the M.D. in 1942. He completed his internship and residence in internal medicine at the Hospital of the University of Pennsylvania, where he became convinced of the importance of combining research and clinical practice. During World War II, Hardy worked in the 81st field hospital in Germany, where he decided to switch from medicine to surgery. After the war, Hardy again joined the University of Pennsylvania where he received a Damon Runyon Clinical Research Fellowship to study the use of heavy water in the measurement of body fluids. This research earned Hardy the Master of Medical Science in physiological chemistry from the university in 1951. That same year, Hardy moved back to his native South becoming Assistant Professor of Surgery at the University of Tennessee at Memphis and Director of Surgical Research. In 1953, Hardy was appointed Chair of Surgery. Two years later, the university started a four-year medical school in Jackson, and Hardy became the first Chair of Surgery in the new center. He held this position until 1987 and it was in this capacity that he performed the transplant operations that would make him famous throughout the world. The most controversial of Hardy’s transplant was by far the chimpanzee-to-man heart transplant performed in 1964. The operation attracted criticism also from some of Hardy’s colleagues. In the long run, Hardy’s animal-to-human transplant helped to establish a more secularized vision of the human body rather than the recipient of a man’s soul. During his long career, Hardy authored several books on surgery, served as editor in chief of academic surgery journals, and was a member of important surgery associations. He was also the 12th recipient of the prestigious ��������������� Rudolph Matas Award in Cardiovascular Surgery. SEE ALSO: Surgery. Bibliography. James D. Hardy, The Academic Surgeon:
An Autobiography (Magnolia Mansions Press, 2003); James D. Hardy, The World of Surgery, 1945–1985: Memoirs of One Participant (University of Pennsylvania Press, 1986). Luca Prono Independent Scholar
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Hardy-Weinberg Law The Hardy-Weinberg law is an equation used in genetics that describes the distribution of alleles in a given population. The equation is based on the idea that in sexually reproducing populations, it is possible to mathematically relate the prevalence of alleles of a particular gene to the resulting genotypes (individual combination of alleles). The Hardy-Weinberg law not only describes the frequency of possible genotypic combinations based on allele prevalence, but it also potentially describes the subsequent frequency of the phenotypes predicted by the expression of those alleles. Hardy-Weinberg Equation The simplest version of the Hardy-Weinberg law describes the distribution of a non-sex-linked allele with only two variations (which we call “a” and “b”) found in a single locus on the chromosome of an organism that sexually reproduces randomly. The equation can be described as follows: q2 + 2pq + p2 = 1 p = frequency of allele “a” q = frequency of allele “b” q2 describes the frequency of homozygous genotype “aa” (and the resulting phenotype), 2pq describes heterozygous genotype “ab,” and p2 describes the frequency of homozygous genotype “bb.” The sum of genotype frequencies is always 1. Assumptions These rules hold constant so long as certain assumptions are met: 1.) The alleles in question do not mutate drastically beyond normal rate over time; 2.) the population is large enough that the allelic distribution is immune to the effects of random genetic mutation (genetic drift); 3.) all individuals have an equal chance of successfully mating with each other; 4.) selection does not occur on the basis of phenotypic expression, and 5.) no migration occurs in or out of the population. We use the following example to illustrate the principles illustrated in the equation above. If the frequency of allele “a” is known to be 0.8, and the frequency of allele “b” is 0.2, then the frequency of the respective genotypes is per Table 1. The resulting
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phenotypic frequency depends on whether expression of one of the alleles dominates. If “a” is a dominant allele, then the predicted combined frequency of phenotypes “aa” and “ab” will be 0.96, or 96 percent of the population, while the expression of recessive allele “b” will be only through genotype “bb,” which constitutes 0.04, or 4 percent of the population. Table 1. Hardy-Weinberg Expression Example Hardy-Weinberg Genotype Expression aa
p
ab
2pq
bb
q2
Genotypic Frequency 0.82 = 0.64
2
2(0.8)(0.2) =0.32 0.22 = 0.04
Aa + ab + bb q2 + 2pq + p2
0.64 + 0.32 + 0.04 = 1.00
Potential Modifications The Hardy-Weinberg equation can be modified to account for more complex patterns, including genes that have more than two alleles or are sex linked. SEE ALSO: Gene Pool; Genes and Gene Therapy; Genetic
Code; Genetics.
Bibliography. William S. Klug and Michael R. Cum-
mings, Concepts of Genetics (Prentice-Hall, 2002) Phillip McClean, “Population and Evolutionary Genetics: The Hardy-Weinberg Law,” http://www.ndsu.edu/instruct/mcclean/plsc431/popgen/popgen3.htm (cited July 2007). Constance W. Liu, M.D. Case Western Reserve University
Head and Brain Injuries Around the world each year, over 1 million people die and 1 million more are disabled from head and brain injuries. Despite their status as a global epidemic, head and brain injuries are also considered a silent epidemic. Serious head and brain injury can occur even without a loss of consciousness and can be overlooked following traffic accidents and sports injuries. A lack of understanding about the nature of head and brain injury among the general public, as well as lack of affordable, accessible medical care, prevents people
from seeking treatment after sustaining such trauma. Head injury is a trauma to the head that may or may not involve the brain. Head injuries are classified as internal or external and are further categorized by mechanism, morphology, and severity. Practical prevention and education about head and brain injuries among the general public, as well as effective diagnosis, treatment, and rehabilitation services for affected individuals are of global health importance. Head injury is a trauma to the head that may or may not involve the brain. Brain injury is often used synonymously with head injury though the latter may not actually involve any neurological complications. Head injuries may be internal or external and can be categorized by mechanism (closed injury or penetrating injury), morphology (fractures, focal intracranial injury, or diffuse intracranial injury), and severity (mild, moderate, or severe). An external head injury is one that does not affect the skull or brain. External injuries may involve a laceration which causes profuse bleeding due to the thousands of blood vessels in the scalp, or trauma which may cause swelling due to fluid or blood buildup beneath the scalp. These injuries can take days or weeks to heal. Internal head injuries are further classified as closed head injury or penetrating head injury. Closed head injuries include any injury in which the scalp is not broken open. Closed head injury may occur with or without damage to the bones of the skull. For example, if a car stops suddenly and passengers experience whiplash, the brain may be jarred and result in concussion although the skull remains intact. Alternately, if the bones of the skull are smashed into the brain as a result of blunt trauma, but the scalp is not lacerated, this too is categorized as a closed head injury. Penetrating head injury occurs when an object transects the scalp, skull, and brain. A bullet that passes into the brain is an example of a penetrating head injury; wounds of this type can cause skull fragments to pierce the brain tissue and are susceptible to infection. Skull fractures are the result of any head injury that breaks the bones of the cranium. All skull fractures are internal injuries though they may not be outwardly visible. Symptoms of skull fractures can include: blood or clear fluid leaking from the nose or ear, unequal pupil size, discoloration around the eyes or ears, swelling or indentation of the cranium, loss of consciousness, memory lapse, blurred vision, confusion,
irritability, or headache. Skull fractures are categorized as linear, depressed, diastatic, or basilar. Linear fractures are a simple break in the bone that does not require serious medical intervention. Depressed fractures are a dented deformation of the skull that often requires surgical intervention. Diastatic fractures occur along the natural suture lines of the cranial bones causing the space between them to widen. This type of injury is more common among infants prior to fusion of these bones. Basilar fractures occur at the base of the skull and may affect the cribiform plate, occipital, temporal, frontal, and sphenoid bones. This type of injury is rare and requires more force than a cranial vault fracture. However, basilar fractures are generally considered severe as they are more likely to be associated with spinal cord, blood vessel, and nerve damage and are susceptible to meningeal infection. Focal intracranial injury denotes trauma confined to one area. These injuries may be extra-axial (within the skull but outside the brain), or intra-axial (within the brain). As the latter are specific to brain injuries, extra-axial injuries will be discussed here. Extra-axial focal intracranial injuries include subdural hematoma, epidural hematoma, and subarachnoid hemorrhage. A subdural hematoma is the collection of blood from a ruptured blood vessel between the arachnoid membrane and the dura; an epidural hematoma occurs between the skull and dura. Both subdural and epidural hematoma can be dangerous to brain function as they may increase intracranial pressure and interrupt the flow of cerebrospinal fluid and oxygen. Diffuse intracranial injury often indicates damage to several areas of the white matter of the brain. This typically includes concussion, coma, or diffuse axonal injury. The severity of a head or brain injury may not always be immediately evident. The most widely used tool in emergency assessment of head and brain trauma is the Glasgow Coma Scale (GCS). This standardized system scores patient competency in eye opening, motor and verbal response; scores between 15 and 13 are considered mild brain injuries, 12 to nine is moderate, and eight to three to are severe. Mild, moderate, and severe are terms used for initial assessment and should not be considered indicators of long-term outcomes. A GCS score can be skewed by shock, intoxication, hypoxemia, metabolic disturbance, spinal cord and orbital injuries, and age. Diagnoses and treatment strategies are based on further physical examination, observation, blood
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tests, imaging including X-ray, magnetic resonance imaging (MRI), computed tomography (CT), and/or electroencephalogram (EEG). Treatment will vary by severity of injury and availability of resources. Foregoing treatment for an initial mild head or brain injury can be risky. After one brain injury has been sustained, the likelihood of recurrence is two to four times greater, placing persons at risk for second impact syndrome or diffuse cerebral swelling. Compared to someone who has never experienced brain injury, the likelihood of recurrence is eightfold after the incurrence of two brain injuries. A six-year investigation into prevention, diagnosis, and treatment of mild traumatic brain injury by the World Health Organization Collaborating Centre Task Force found that a consensus among experts is lacking. The task force concluded that “clear, comprehensive, evidence-based guidelines dealing with mild traumatic brain injury are urgently needed.” Of the reported traumatic brain injuries, approximately 80 percent are classified as mild traumatic brain injuries. As it is extremely challenging to collect reliable data on cases of head and brain injury in the absence of hospitalization, the actual number of persons experiencing mild traumatic brain injury is probably much higher than current data reveals. Practical prevention and education about head and brain injuries among the general public could decrease their occurrence. Effective diagnosis, treatment, and rehabilitation services for affected individuals are of global health importance and can have a profound effect on the quality of life of individuals, families, and communities.
CT scans are used in diagnosing the severity of a head or brain injury, along with X-rays, MRIs, and EEGs.
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SEE ALSO: Brain Injuries; Concussion; Neurology; Reha-
bilitation; Sports Injuries; Stroke.
Bibliography. Christopher J.L. Murray and Alan D. Lo-
pez, Global Health Statistics (Harvard University Press, 1996). Paul Peloso, et al., “Critical Evaluation of the Existing Guidelines on Mild Traumatic Brain Injury,” Journal of Rehabilitation Medicine (v.36/43, 2004); Ian Roberts, “The CRASH Trial: The First Large-scale, Randomized, Controlled Trial in Head Injury,” Critical Care (October 2001). Jennifer Hissett University of Colorado at Denver Health Services Center
Head and Brain Malformations The most relevant head malformation is a condition called craniosynostosis, or the premature fusion of one or more of the head’s sutures. The human head is composed of multiple bones held together by several sutures, namely the metopic, coronal, sagittal, and lambdoid sutures. Simple craniosynostosis is when only one suture is involved, while compound craniosynostosis involves two or more sutures. The most common suture affected is the sagittal suture (50 percent of cases), followed by the coronal suture (25 percent), and metopic suture (10 percent). Lambdoid synostosis is very rare, with an incidence of 3 per 100,000 births. The overall prevalence of craniosynostosis is approximately 1 per 2,000 births, or 0.05 percent of children. One-fifth of craniosynostosis cases occur as one of more than 150 different syndromes, while the remainder occur as an isolated, nonsyndromic condition. The etiology of craniosynostosis is unknown. Several risk factors for the development of this condition have been identified and can be categorized by maternal factors, paternal factors, and infant factors. Maternal factors include white race, advanced age, smoking habits, residence at high altitude, and use of certain medications. Paternal factors include specific occupations, such as in agriculture, forestry, or mechanics. Infant factors include male sex. Genetics also play a role, given that a certain percentage of cases are familial and autosomal dominant in inheritance.
One known genetic mutation is in the gene encoding fibroblast growth factor receptor (FGFR), which is known to be expressed in the cranial sutures. Therefore, if a receptor is produced with a faulty molecular structure or in insufficient quantities, the skull’s sutures may not fuse correctly. Craniosynostosis is diagnosed by physical examination, X-rays, and computed tomography (CT). Physical examination findings may include a misshapen head as well as nonpatent suture lines and fontanelles (soft spots) on the child’s head. The signs of craniosynostosis on X-ray include bony bridging across the suture that produces beaking or heaping up of bone; sutures that appear very straight and narrow; and loss of suture clarity. Because CT offers a clearer picture than X-rays, it is the most reliable diagnostic tool. Craniosynostosis that goes uncorrected may result in increased intracranial pressure (ICP), an asymmetric face, malocclusion (misaligned teeth), and strabismus. Correction, therefore, is surgical and is preferably performed between 3 and 9 months of age by a pediatric neurosurgeon. The different surgical options include strip craniectomy and cranial vault remodeling. Strip craniectomy can now be performed with a minimally invasive, endoscopic technique. By definition, syndromic craniosynostosis involves multiple organ systems, that is, cardiac, renal, and musculoskeletal. The two most common syndromes are Crouzon’s disease and Apert’s syndrome, both of which are caused by autosomal dominant mutations on the FGFR2 gene on chromosome 10. The incidence of Crouzon’s disease is one per 25,000 and it accounts for 5 percent of craniosynostosis cases. External findings include wide-set and bulging eyes (hypertelorism and proptosis, respectively), beaked nose, and cleft palate. The patient’s brain may be affected by hydrocephalus and/or Chiari malformation. Apert’s syndrome affects one per 160,000 and is marked by syndactyly (webbed fingers/toes), hypertelorism, and shallow eye orbits. Intracranial findings in a patient with Apert’s syndrome may include megalocephaly and agenesis of the corpus callosum, both of which may contribute to cognitive deficits. Patients may also have cardiac and renal anomalies, such as atrial/ventricular septal defect and hydronephrosis, respectively. One condition that can be mistaken for craniosynostosis is deformational (positional) plagiocephaly, or flattened head syndrome. This condition has increased
Head and Neck Cancer
in prevalence over the past few decades to about 33 per 10,000 births, or approximately seven times more common than craniosynostosis. The increased prevalence is because of increased efforts to have infants sleep on their backs to prevent sudden infant death syndrome (SIDS), as well as increased awareness of the problem. Plagiocephaly is most commonly caused simply by the passage of the baby’s head through the birth canal. Fortunately, plagiocephaly can usually be corrected by alternating the position of the child until the head corrects itself. SEE ALSO: Brain Malformations; Cleft Lip and Palate; Ge-
netics; Hydrocephalus; Sudden Infant Death Syndrome (SIDS).
Bibliography. Haidar Kabbani and Talkad S. Raghuveer,
“Craniosynostosis,” American Family Physician (v.69, 2004); P. J. Vinken and G. W. Bruyn, Congenital Malformations of the Brain and Skull (Elsevier/North Holland, 1977).
Khoi D. Than, M.D. Johns Hopkins University School of Medicine
Head and Neck Cancer In the United States, cancers of the head and neck are most commonly a result of repeated exposure to toxins, such as cigarette smoke or alcohol. As a matter of fact, the combined effects of exposure to cigarette smoke and alcohol is multiplicative in head and neck cancers (HNCs). Signs and symptoms of possible HNCs include a lump in the throat, a growth in the oral cavity, difficulty swallowing, changes in vocal sound, or changes in skin. Therapies for HNCs typically involve a combination of chemoradiation therapy and surgical resection. Because such procedures would be carried out by a team of otolaryngologists and oncologists, cancers of the brain will not be discussed as that falls under the jurisdiction of neurosurgeons. Nasal Cavity Cancers in the nasal cavity occur around the nasal sinuses, thus termed paranasal sinus cancers. The most common presenting symptoms of cancer of the sinuses are facial or dental pain, epistaxis, or frequent nose bleeds, and persistent unilateral nasal obstruc-
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tion. These cancers have a multitude of causation including occupational exposure to toxic vapors such as formaldehyde. In addition, genomic evidence of the presence of infectious agents such as human papillomavirus 16 and 18 and Epstein-Barr virus in biopsies of paranasal sinus cancers points to virus causality. Finally, cigarette smoke and air pollution are linked to cancers of the nasal cavity. As in HNCs, the most common cancer of the nasal sinuses is squamous cell carcinoma. They are relatively slow growing and well differentiated. Esthesioneurblastoma is a rare cancer of the nasal cavity involving the olfactory epithelium. This cancer is believed to derive from uncontrolled proliferation of neural progenitors. Oral Cavity Squamous cell carcinoma, a cancer that grows exophytically and is ulcerative, is the most common form of cancer found in the oral cavity. These cancers tend to occur later in life. Major predisposing factors leading to squamous cell cancers in the oral cavity include leukoplakia, infection with human papillomavirus (types 16, 18, and 33), alcohol abuse, and mechanical irritation. It is common place for smokers to switch from cigarettes to chewing tobacco in an attempt to prevent lung cancer. What many do not realize, however, is that they are increasing the probability of inducing cancer of the mouth. Patients who have chewed large amounts of tobacco over long periods can develop leukoplakia, a precancerous lesion that presents as white plaques in the oral mucosa. These plaques are overgrowths of squamous epithelia and are usually dysplastic. Leukoplakia plaques, which are often multifocal, can be found on the vermilion border of the lower lip, buccal mucosa, hard or soft palates, as well as at the bottom of the mouth. While most are a result of long-term tobacco use (including that derived from smoking), they can also be a result of chronic friction (such as from braces or dentures), excessive alcohol consumption, and some foods. About 3 to 6 percent of leukoplakia lesions convert to squamous cell carcinoma. Gingival cancers typically occur in women on the lower alveolar ridge or gum line around the sixth decade of life. Due to tight adherence between the gum and the mandibular periosteum, these cancers can invade the mandible leading to bone damage.
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Salivary Gland Of the three salivary glands—parotid, submandibular, and sublingual—the cancer most commonly involves the parotid gland (around 70 percent). Of those, about 15 to 25 percent are malignant. Unlike other HNCs, salivary gland cancer is not highly correlated with smoking and excessive alcohol consumption. Instead, exposure to radiation and infectious agents such as Epstein-Barr virus has been linked. Pleomorphic adenomas are benign encapsulated gland tumors comprised of both epithelial and stromal or supporting cells. Histologically, they appear as collections of spindle and stellate cells. Parotid gland tumors can result in impingement on the CN VII (facial nerve) which is almost always a sign of malignancy. Malignant conversion of pleomorphic adenomas results in malignant mixed salivary gland tumor. Warthin tumor (papillary cystadenoma lymphomatosum) is a benign encapsulated growth with many cysts. These tumors rarely convert to malignant forms and often occur bilaterally. Intraductal papillomas are benign growths of the submucosa of glandular ducts. Sjogren’s syndrome is a major cause of benign proliferation of the parotid gland. Sjogren’s syndrome is an autoimmune disease more commonly affecting women. It is characterized by nontender, enlarged parotid glands which have a higher predisposition for converting into a lymphoma. Larynx and Esophagus The larynx is the most common site of HNC occurrence in the United States. Fortunately, detection of laryngeal cancers is able to occur during early stages because these cancers commonly affect the patient’s voice, causing hoarseness. Laryngeal cancers arise from environmental factors including asbestos or radiation exposure and long-term tobacco and alcohol use, the effects of which are synergistic. The most common laryngeal cancer is squamous cell carcinoma, which has a pearl-gray appearance on gross examination. Because this cancer can occur on the vocal cords, surgical resection leads to damage or loss of the patient’s voice. Esophageal cancer comes in two forms: squamous cell carcinomas and adenocarcinomas. Usually, squamous cell carcinomas are found in the upper twothirds of the esophagus, while adenocarcinomas occur in the distal one-third of the esophagus.
Squamous cell carcinoma of the esophagus is believed to be associated with environmental factors including exposure to toxins, such as alcohol consumption and tobacco use, and dietary issues. Deficiency in vitamins A, B1, B2, B6, and C, deficiency in zinc and molybdenum, food contamination with fungi, or high concentration of nitrates in food are common causes of squamous cell carcinoma of the esophagus. Adenocarcinomas typically arise from Barrett esophagus, a complication of long-standing acid reflux. Repeated trauma of stomach acid exposure can lead to metaplasia of the normal distal epithelium of the esophagus from stratified squamous epithelium to columnar epithelium with goblet cells. Diagnosis of HNCs begins with localization of the tumor via imaging techniques such as computed tomography scans followed up with fine-needle aspiration biopsies. Although HNCs result from a large array of causes, the most common treatment for HNCs is surgical resection with and without adjuvant radiation therapy. SEE ALSO: Cancer (General); Cancer Alternative Ther-
apy; Cancer Chemotherapy; Cancer Radiation Therapy; Cancer—Coping with Cancer.
Bibliography. H. Mineta, et al., “Human Papilloma Vi-
rus (HPV) Type 16 and 18 Detected in Head and Neck Squamous Cell Carcinoma,” Anticancer Research (v.18/ 6B, 1998); R.H. Spiro, “Salivary Neoplasms: Overview of a 35-Year Experience with 2,807 Patients,” Head & Neck Surgery (v.8/3, 1986); M.R. Spitz, “Epidemiology and Risk Factors for Head and Neck Cancer,” Seminars in Oncology (v.21/3, 1994). Kimberly Gokoffski University of California, Irvine
Head Lice Three species of lice (small, wingless insects) infest humans—Pediculus humanus capitis (head lice), Pediculus humanus corpus (body lice) and Phthirus pubis (pubic lice). Many treatments exist, and patients need to ensure removal of the lice from hair as well as clothing. Lice live and reproduce only on humans, transmitted by person-to-person contact or clothing, as human lice can survive on fabric for 10 days. Lice cycle through
Headache and Migraine
three stages—egg, nymph, and adult. Eggs are deposited on the hair shaft, providing warmth for incubation. The baby louse (nymph) hatches, leaving behind nits (casts of the empty egg)—tiny, yellow/white ovals, firmly cemented to the hair shaft. Visualization of the louse or detection of eggs within five millimeters of scalp permits diagnosis. Nits seen further along the shaft indicate prior infestation and may not need treatment. Head lice do not transmit disease, only itching. Lice require several blood meals daily and have special mouthpieces for this purpose. Saliva is injected into the feeding site, causing sensitization to foreign antigen, eventually causing itching with repeated bites. Delousing options include chemical treatments with Federal Drug Administration (FDA) approved overthe-counter preparations containing permethrin or pyrethrins, to manual removal. Medications do not kill unhatched embryos; hence, repeat administration must be done after a week to kill newly hatched nymphs. Fine-toothed combs will remove eggs, and hair must be combed daily until there are no further signs of infestation. Vinegar will loosen eggs from the hair shaft, permitting easier removal. All contacts of the infected individual must be treated simultaneously prevent reinfestation. Bedding and clothes must be washed on the hottest setting. Items unable to be washed should be doublebagged in closed dark trash bags, set aside for three days, then washed. Dry cleaning and ironing will kill lice and eggs. Hair implements should be soaked in a weak bleach solution or rubbing alcohol for one hour. Carpets must be vacuumed and other fabrics treated with insecticides. This entire process must be repeated in five to seven days to prevent reinfestation with newly hatched nymphs. SEE ALSO: Hair Diseases And Hair Loss; Infant and Tod-
dler Health, Infectious Diseases (General).
Bibliography. Pediculosis.com, www.pediculosis.com;
www.cdc.gov/ncidod/dpd/parasites/lice/default.htm (cited October 2006); A. Goldstein, B. Goldstein, “Pediculosis,” www.uptodate.com (cited October 2006). Gautam J. Desai, D.O. Karen H. Wendel Kansas City University of Medicine and Biosciences College of Osteopathic Medicine
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Headache and Migraine Complaints of headache are common making evaluation difficult. Essential to diagnosis and management is working with the patient to determine medical and family medical history in addition to symptoms. Treatment must be based on the cause of the headache. Patients assist in the diagnosis by providing information to describe the pain in relation to intensity (how much it hurts), quality (stabbing, throbbing, ice pick, etc.) site of pain (neck, forehead, localized, on both sides, etc.), associated symptoms (vision disturbances, vertigo, nausea and vomiting, etc.), and duration and frequency of pain. Sudden onset headache and major complaint of headache without trauma necessitates determining cause and provide immediate treatment for any underlying causes for which the headache may be a secondary symptom. The underlying cause may be vascular, infection, intracranial masses, preeclampsia, carbon monoxide poisoning. In addition to taking vital signs and checking eyes/vision, performing neurological, motor and sensory testing, the physician may also order further tests. Additional tests include blood testing, electrocardiogram, electroencephalogram, computed tomography (CT) scan or magnetic resonance imaging (MRI) will exclude intracranial mass lesion, MR angiography or venography can detect suspected aneurysms and weak areas of vessels. Lumbar puncture will exclude infections. After determining medical history, physical examination and testing the diagnosis is determined and treatment options considered. The two possible diagnoses for headache are secondary (a symptom of an underlying cause) or primary (tension headache or migraine). Secondary headache pain is a symptom of other illnesses, due to injury, infection, brain malformation, depression, tumors, spinal headache, sinus congestion, aneurysm, giant cell arteritis (inflammation of blood vessels in the head most often seen in elderly patients), cough, hypertension, exertion (exercise including sex), mountain sickness (hypoxia at altitudes 6,560 feet above sea level. When the diagnosis is primary headache, the headache itself is the illness. The most common and least debilitating primary headache is the ice-cream headache. Other headache triggers include stress, weather or season changes, certain foods and alcohol, and flickering light.
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Tension Headaches The pain has a tight pressing quality, worse with stress or at the end of the day. The pain may be generalized or intense around the neck or back of head. Tension headaches are often triggered by stress, fatigue, noise, and glare. Treatment includes analgesics and relaxation techniques of massage, hot baths, and biofeedback. When medications such as aspirin, ibuprofen, acetaminophen, and similar drugs fail, using migraine medication may be effective. Alternative treatments or supportive therapies for tension headache include acupressure, acupuncture, chiropractic, Feldenkrais method (touch to improve movement and movement awareness), hypnotherapy, meditation, myotherapy (deep muscle massage), osteopathic medicine, qigong (Chinese discipline of breathing and exercise), and reflexology (applying pressure to specific points on the foot) Cluster Headaches Most common in middle-aged males, the pain is excruciating and accompanied by nasal congestion, tears, and red or swollen eyes. Cluster headaches often occur at the same time each day experienced. The pain may be located around the eye, temple, and upper jaw. Cluster headaches are often triggered by alcohol and certain foods. During an acute attack, treatment with sumatriptan or dihydroergotamine can relieve the pain. The recurring nature of these headaches indicates treatment with maintenance medications. Migraine While scientists continue to search for specific etiology some studies have connected migraine activity to the neurotransmitter serotonin, brain hyperexcitablilty, the aura is caused by a wave of increased electrical activity and blood flow followed by a loss of electrical activity and decreased blood flow, the area of brain in upper brainstem holds pain sensors, inflammation of the meninges or blood vessels causes throbbing pain, scalp sensitivity to touch and increased pain with bending, straining, or shaking head. Hormonal aspects may trigger migraine either with rising estrogen levels or by taking oral contraceptives or hormone replacement. Migraines can be chronic occurring more than 15 days per month or episodic occurring less than
Some headache triggers include stress, weather or season changes, certain foods and alcohol and flickering light.
15 days per month to as few as one per year. A migraine headache may result in sensitivity to light and have an “aura” followed by severe throbbing unilateral headache lasting from a few hours to one to two days. Migraines are more common in women because of hormonal fluctuations. They start in adolescence and early adulthood and decrease with advancing age. They may occur once a year or as often as one to two times per week, and often after a stressful event. An aura is associated with an abnormal release of serotonin from platelets and the throbbing headache associated with decrease of platelet and serum serotonin levels. Other chemical triggers include falling estrogen levels and elevated levels of prostaglandin E1. Persons who experience migraine headaches may experience a common migraine or migraine with aura. Common migraine involves headache on one side, sensitivity to light and/or sound and accompanied by nausea and vomiting. Complete migraine has specific stages: pre-headache, aura, headache, and resolution. The stage before headache includes one or more symptoms of feeling sluggish, depressed, yawning, experiencing mood changes, or irritability. The aura includes visual aura, floaters in front of the eyes, hallucinations, seeing flashing lights, experiencing decreased vision or sensory aura feeling tingling and numbness. Headache is pulsating, throbbing
pain. The resolution stage follows the resolution of the pain and feelings or sensations, out of proportion, depression or tiredness, joy, or mania. Two types of rare migraine basilar artery migraine and ophthalmoplegic migraine involve severe visual disturbances along with the throbbing pain. Basilar artery migraine is experienced with blindness, dizziness, ringing in the ears, and facial numbness leading to disturbed consciousness and confusion. In ophthalmoplegic migraine pain around the eye, nausea and vomiting, double vision is due to nerve palsy with the potential to lead to long-term nerve deficiency. The pathophysiology of migraine appears to include vasomotor mechanism and treatment with medications to relieve arterial pressure and related to the neurotransmitter serotonin. For many years, the common medication for treating migraine was ergot alkaloids. The specific action of these medications also had diagnostic potential, if the medication worked, the headache was migraine. Current treatment during an acute attack includes a variety of fast-acting medications in injectable, nasal and oral forms, with sumatriptan often considered the drug of choice. Alternative therapies include acupuncture, Alexander technique (inhibition of habitual muscular movement and encouraging the body’s natural reflexes to take over), biofeedback, energy medicine (electrical nerve stimulation by electrodes placed near painful site or in proximity to the nerve supplying the painful area), and hypnotherapy. Some physicians experiment with and recommend herbal and mineral remedies to their patients including feverfew, magnesium, and riboflavin. People who experience frequent headaches may benefit from following a healthy lifestyle includingmonitoring their diets, getting enough sleep, and exercising. Patients can take an active part in their healthcare by keeping a journal to record information pertinent to the headaches, which will help their physician with a proper diagnosis and treatment and to establisyh goals for pain management. For additional information, the American Council for Headache Education maintains a Web site at www.achenet.org. See Also: Biofeedback; Chiropractic; Osteopathy. Bibliography. Michael J. Aminoff, “Nervous System”
in Current Medical Diagnosis & Treatment 2004 (Lange,
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2004); David W. Sifton, The PDR Family Guide to Natural Medicines & Healing Therapies (Three Rivers Press, 1999); William B. Young, and Stephen D. Silberstein, Migraine and Other Headaches (American Academy of Neurology, 2004). Lyn Michaud Independent Scholar
Healthcare, Africa The healthcare system in Africa today varies hugely. In some areas of the continent, diagnosis and treatment is excellent, but there are also many other areas where the system is clearly substandard. Much of this is because of historical reasons, and the systems introduced or neglected by various colonial powers and, after independence, the governments of the respective countries, not having the resources, human or financial, to do everything that was needed to be done. Prior to the arrival of the colonial powers, there were a range of healthcare systems used in Africa. In Ancient Egypt, surviving clay tablets show that the doctors were often sent to study in Syria and Assyria. It is also clear that they had identified and differentiated between about 200 types of illnesses, with substantial knowledge about the human anatomy, as evident in their embalming processes. The kings of Persia employed Egyptian physicians, and the Greek writer Herodotus describes the specialties of the doctors. These advances in healthcare also influenced the civilizations near Egypt—both in north Africa and in Sudan and Ethiopia. The Carthaginian Empire tended to draw much of their medical sciences from the Phoenicians and also the Greeks, with Roman healthcare ideas tending to dominate north Africa from the 3rd century b.c.e. These gradually came to see the body as being made up of humors and medical problems being an imbalance of the different humors. With the spread of Arab culture from the 6th and 7th centuries c.e., there was a change in healthcare, with many problems having a more scientific diagnosis. The nature of healthcare was much advanced by the great Arab medical writer Avicenna (980–1037 c.e.) whose ideas were popular in north Africa for many centuries.
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In areas that had large British and European populations, such as South Africa, Southern Rhodesia (modern-day Zimbabwe), and Kenya (pictured above), the level of healthcare was better than in the areas that had small white populations.
In sub-Saharan Africa, healthcare was generally fairly primitive and relied heavily on the use of witch doctors and shamans, as well as on herbal cures and pastes, some of which were effective at dealing with particular ailments. Many of the illnesses which existed during this period remain prevalent with several strains of malaria, yellow fever, typhus, sleeping sickness, “river blindness,” cholera, and polio. There have also been problems with leprosy, snakebites, and a host of other medical problems. The early European colonial powers had to quickly introduce healthcare systems largely because of the number of early sailors and soldiers who died from tropical diseases. In particular, malaria remained a major problem until the 20th century, with a Nigerian nationalist group using the mosquito as their symbol on the basis that it had resulted in the deaths of more Europeans than from any other single cause. The Portuguese were the first European power to make extensive voyages around the coast of Africa, and the first to establish large numbers of bases on
the continent. They drew some of their healthcare ideas from Garcia de Orta (1501/02–68), a Portuguese Jewish physician who was able to work out cures for people suffering from some common tropical diseases, especially cholera. It was not long before the Portuguese established hospitals in their colonial possessions, but these only catered to Europeans and members of the local elite. In most of their colonies, the Europeans suffered most commonly from malaria, with treatment until the early 20th century being difficult until it was proven that the Anopheles mosquito was the vector by which people caught the disease. The Portuguese government sponsored a number of conferences on malaria and other tropical diseases, with a series of stamps issued in their colonies in December 1958 highlighting a Tropical Medicine Congress, and another series in 1962 about an antimalaria campaign, not just for prestige, but also to inform the local population. Because of centuries of neglect, the healthcare system in most former Portuguese colonies remains
poor, although in Angola, there are, on average, some 7.7 doctors and 115 nurses per 100,000 people. It is also estimated that 30 percent of the population can reach hospitals or clinics within an hour. The reason for this might be connected with Agostinho Neto (1922–79), the longtime nationalist leader and the first president after independence being a Lisbontrained doctor. Much of this progress has also come from considerable expenditure by the present government during the last decade. By contrast in Mozambique, the civil war which wrecked the economy of the country since independence in 1975, there are 0.76 doctors per 100,000 people, and one hospital bed per 1,133 people. The healthcare services in Cape Verde are also poor with 17 doctors and 56 nurses per 100,000 people; with 17 doctors and 109 nurses per 100,000 people in Guinea-Bissau, 47 doctors and 127 nurses per 100,000 people in São Tomé. Because of a historical agreement with the Portuguese, the Spanish had only a few isolated colonial possessions in Africa. Their original possessions in Morocco were mainly military and trading bases which had only primitive healthcare. The Spanish army, as with other colonial armies, had a number of military doctors and hospitals at their disposal. The settlers also had access to health services that were not made available to the locals. Later, during the early 20th century, in Spanish Morocco there was a great focus on eradicating diseases such as cholera and leprosy, with the Spanish colonial postal authorities issuing large numbers of “semipostal” stamps to raise money for healthcare. Toward the bottom end of the scale, since independence in 1968, the healthcare provisions in Equatorial Guinea remain very poor with only 25 doctors and 40 nurses per 100,000 people. The first British settlements in Africa were often forts which usually included small garrison hospitals. As the settlements grew, these facilities steadily improved and hospitals were built. Among the many Britons who worked as doctors in Africa was Dr. David Livingstone (1813–73), the missionary and Hugh Lofting (1886–1947) who was also the creator of Doctor Doolittle. In the Sudan, Charles E.G. Beveridge, born in Samoa, and from an Australian family, worked for the Sudan Medical Services for most of his life. In the areas that had large British and European populations, such as South Africa, Southern Rhodesia (modern-day Zimbabwe), and
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Kenya, the level of healthcare was better than in the areas that had small white populations. As many of the countries became independent during the 1950s and 1960s, there was a vast improvement in healthcare with help from the World Health Organization. Inoculations and greater health education helped improve life expectancy rates. Gradually, the governments have worked to erode the threat from malnutrition, malaria, cholera, and polio. With more people living longer, liver cancer and some other cancers have become more prevalent. However, during the late 1980s, life expectancy figures fell dramatically with the spread of HIV/AIDS, and the rise in the number of deaths from conditions which were affected by HIV such as pneumonia and Kaposi’s sarcoma. With many wars in Africa, and many crises, the work of Médicine sans Frontières has saved the lives of many people, often in appalling conditions, and without much help from governments. In South Africa, some of the best healthcare in Africa is available, but much of it is restricted to the major cities. The South African surgeon Dr. Christiaan Barnard (1922–2001) performed the first heart transplant operation on December 3, 1967. Areas that were formerly dark-skinned tend to have much lower healthcare available, with the statistics for the entire country being 56 doctors and 472 nurses per 100,000 people, one of the best rates in Africa. Of the former parts of British Africa, the ratios are only higher in Seychelles which as 132 doctors and 468 nurses per 100,000 people. In Namibia, the ratios are 30 doctors and 168 nurses per 100,000, in Botswana, the respective ratios are 24 and 219 per 100,000; the ratios in Nigeria are 19 nurses and 66 doctors. During British colonial rule, healthcare provisions for Europeans in Southern Rhodesia were very good with Salisbury Hospital and Bulawayo Hospital having much of the equipment which one would have found in hospitals in Europe at the same time. Since independence in 1980, there have been attempts by the government to increase healthcare for the entire population, with a network of hospitals and rural health centers providing increasing levels of care, with Zimbabwe (as it became after 1980) having 14 doctors and 129 nurses per 100,000 people. In Swaziland, there are 15 doctors per 100,000 people; and in Kenya there are 13 doctors and 90 nurses per 100,000 people. Again, like Zimbabwe, Kenya had a
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significant European population and there are hundreds of hospitals and health centers throughout the country, with the provision of free medical care to all children and adult outpatients. The Kenya Medical Research Institute (KEMRI) was established in 1979 and has done much in recent years to coordinate healthcare. Accounts of the Kenyan medical services have been written by expatriate doctor Christopher Wilson and Canadian nurse Ruth S. Best. The remainder of former British Africa has fared far worse with Sierra Leone, before the recent fighting, having 7.3 doctors and 33 nurses per 100,000 people, with 45 hospitals throughout the country. For the other countries, the ratio of doctors and nurses per 100,000 people are Zambia 6.9 and 113; Ghana 6.2 and 72; Lesotho 5.4 and 60; Tanzania 4.1 and 85; Gambia 3.5 and 1.3; and Uganda 0.4 and 19. One of the more well-known doctors in Tanzania, Emmanuel N. Ayim, originally from Ghana, is the father of Afro-German scholar May Ayim. The poor figures for Uganda come largely from the civil strife that it faced from the 1970s. Prior to that, the health system was relatively good—for a British African colony—with Denis Parsons Burkitt (1911–93) working there and coming across what became known as Burkitt’s lymphoma, a cancer in the lymphatic system. In Malawi (formerly Nyasaland), despite Dr. Hastings Banda (1898–1997), a former doctor in Britain, running the country for the first 31 years after independence, it has only 51 hospitals and clinics and one of the lowest ratio of doctors and nurses 0.9 doctors and 3 nurses per 100,000 people. In former French colonies in Africa, the two countries that have the best rates of healthcare are Algeria and Tunisia. In the former, the French army doctor Xavier Quatrefarges lived during the 1840s along with his wife Eliza Lynch, later first lady of Paraguay. The great Algerian-French writer Albert Camus (19131960), wrote The Plague (1947), an allegory described by way of an epidemic in a city in French Algeria. Nowadays, there are 85 doctors and 298 nurses per 100,000 persons, with medical care free for middleand low-income earners, with healthcare good in the cities but still poor in remote parts of the country. In Tunisia, there as 70 doctors and 286 nurses per 100,000 people, with massive improvements in healthcare during the 1980s and 1990s. In the rest of former French Africa, the healthcare system has been
worse, with Congo having 25 doctors and 185 nurses per 100,000 people, with three general hospitals and over 500 medical centers throughout the country. In Djibouti, there are 14 doctors and 74 nurses per 100,000 people, and in Mauritania, the ratios of 14 doctors and 62 nurses must be seen in the context that there is only one hospital in the entire country, although there are 25 regional health centers. In Guinea, there are 13 doctors and 56 nurses per 100,000 people, with the ratios in Madagascar being 11 doctors and 22 nurses; in the Cote d’Ivoire, nine doctors and 31 nurses; in Cameroon, 7.6 doctors and 37 nurses; in Togo, 7.6 doctors and 30 nurses; in Senegal, 7.5 doctors and 22 nurses; and in Comoros, 7.4 doctors and 34 nurses. In most of the rest of former French Africa, healthcare is far more rudimentary. There are only 5.7 doctors and 230 nurses per 100,000 in Benin; 4.7 doctors and 13 nurses per 100,000 in Mali; and 3.6 doctors and 37 nurses per 100,000 in Gabon. The healthcare service in Gabon has become most well-known by the work of Dr. Albert Schweitzer (1875-1965), the German doctor who moved to Lambaréné in Gabon where he rebuilt a derelict hospital and ran a leper colony until his death. The Central African Republic has 3.5 doctors and 8.8 nurses per 100,000 people with few facilities available outside Bangui, the capital. In Niger, with 3.5 doctors and 23 nurses per 100,000 people, there are only two hospitals in the entire country, with only 32 percent of the population within one hour of access to appropriate medical care. Healthcare is even worse in Burkina Faso (formerly Upper Volta), where there are only 3.4 doctors and 20 nurses per 100,000 people, with only a third of the population having access to safe drinking water. In Chad, a third of the children under the age of 5 suffer from malnutrition, and with 3.3 doctors and 15 nurses per 100,000 people belies the fact that most of the health services are concentrated in the south. The Germans and the Belgians, in their African colonies, provided hospitals for their own settlers and for other Europeans, but little or no healthcare for the local population. After World War I, the German colonies were taken over by the other colonial powers, with the Democratic Republic of Congo (formerly Belgian Congo and later Zaire) now having a reasonably extensive healthcare system with 6.9 doctors and 44 nurses per 100,000 people.
In neighboring Rwanda and Burundi, German colonies and later Belgian colonies, the healthcare system in both countries has been poor in colonial times and since independence. Some of the former Italian colonies have had very poor healthcare, with Alberto Denti di Pirajno’s best-selling books, A Cure for Serpents (1955) and A Grave for a Dolphin (1956), describing the problems facing doctors in the Italian colonies. The system in Somalia—part of which had been an Italian colony, and the other part being British—has all but collapsed during recent civil wars. In Libya, at independence the healthcare system was in a deplorable state, but since the discovery of oil, has seen considerable wealth and it now was 128 doctors and 360 nurses per 100,000 people, with all healthcare, including the provision of medicine, being free. In Eritrea, there are only three doctors and 16 nurses per 100,000 people, with up to half of all infants dying in their first year. In connection with Eritrea, mention should be made of the Australian doctor Dr. Fred Hollows who established an eye hospital in Asmara. In Ethiopia, briefly an Italian colony, the healthcare service has remained one of the worst in Africa, with only 1.2 doctors and 18 nurses per 100,000 people. However, the Addis Ababa Fistula Hospital, cofounded by Australian Dr. Catherine Hamlin, treats about 1,400 women suffering from obstetric fistula each year. Liberia, the only part of Africa not to be colonized, has 2.3 doctors and 5.9 nurses per 100,000 people, with malaria and leprosy rife. See Also: AIDS; Djibouti; Guinea Malaria; South Africa. Bibliography. Adelola Adeloye, ed., African Pioneers
of Modern Medicine: Nigerian Doctors of the Nineteenth century (University Press, Nigeria, 1992); Adelola Adeloye (ed), Nigerian Pioneers of Modern Medicine (Ibadan University Press, 1977); J.D. Alsop, “Sea Surgeons, Health and England’s Maritime Expansion: the West African trade 1553–1660,” Mariner’s Mirror (v.76/3, 1990); Knud Balslev, A History of Leprosy in Tanzania (African Medical & Research Foundation, Nairobi, 1989); Ahmed Bayoumi, The history of the Sudan Health Services (African Medical and Research Foundation, Nairobi, 1979); Heather Bell, Frontiers of Medicine in the Anglo-Egyptian Sudan 1899–1948 (Oxford University Press, 1999); Ann Beck, A History of the British Medical Administration of East Africa 1900–1950
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(Harvard University Press, 1970); Ruth S. Best, Strawberries All Year Round (Best, Toronto, 1970); Leonard Bousfield, Sudan Doctor (C. Johnson, 1954); Cole P. Dodge and Paul D. Wiebe, eds., Crisis in Uganda: The Breakdown of Health Services (Pergamon Press, 1985); Alberto Denti di Pirajno, A Cure for Serpents: A Doctor in Africa (Andre Deutsch, 1955); T. Gerald Garry, African Doctor (The Book Club, 1939); Michael Gelfand, A Service to the Sick: A History of the Health Services for Africans in Southern Rhodesia 1890–1953 (Mambo, 1976). Justin Corfield Geelong Grammar School, Australia
Healthcare, Asia and Oceania Healthcare varies in Asia and Oceania depending on a number of socioeconomic factors. Japan, for instance, has a more sophisticated healthcare delivery system because of its position as a world economic force. In contrast, more isolated and primitive locations such as Papua New Guinea have few, if any, public health service options. japan Since World War II, Western biomedicine has dominated Japanese medical care. Public health services, including free screening examinations for particular diseases, prenatal care, and infectious disease control are provided by national and local governments. Payment for personal medical services is offered through a universal medical insurance system that provides relative equality of access, with fees set by a government committee. People without insurance through employers can participate in a national health insurance program administered by local governments. Since the 1970s, all elderly persons have been covered by government-sponsored insurance. Patients are free to select physicians or facilities of their choice. By the turn of the 21st century, there were more than 8,700 general hospitals, more than 1,000 comprehensive hospitals, and approximately 1,000 mental hospitals in Japan with a total capacity of 1.5 million beds. Hospitals provided both outpatient and inpatient care. In addition, 79,000 clinics offered primarily outpatient services, and there were 48,000 dental clinics. Most
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Healthcare, Asia and Oceania that is relevant to a nation like Japan. It is thought that HIV/AIDS is a problem caused by and affecting only foreigners. As a result, compared with other countries, HIV/AIDS is of relatively little concern to the Japanese government and population. Therefore, education and awareness campaigns about the disease, while available, are not considered of the utmost importance.
Japan has a more sophisticated healthcare delivery system because of its position as a world economic force.
physicians and hospitals can sell medicine directly to patients, but there are more than 36,000 pharmacies where patients can purchase synthetic or herbal medication. While national health expenditures have risen in recent years and conditions continue to improve, the system is not perfect. Cost-control problems, excessive paperwork, long waits to see physicians, assembly-line care for outpatients (because few hospitals or clinics make appointments), overmedication, and abuse of the system are some of the traditional ills of the Japanese healthcare system. Another problem is an uneven distribution of health personnel, with cities favored over rural areas. Recent improvements in the system have been made in an attempt to produce equity between the rural and urban populations, but those in the countryside are still less likely to receive adequate care at all times. With a prevalence rate around .02 percent, Japan is fortunate to be one of the countries that has been the least affected by HIV/AIDS. However, the lack of contact and familiarity with the disease has meant that education about it is somewhat limited. Lack of awareness has resulted in many misperceptions and stigmas about HIV/AIDS in Japanese society. For instance, many view HIV/AIDS as a problem of poor, developing countries rather than something
the philippines Health conditions in the Philippines approximate those in many other southeast Asian countries but lag behind those in the West. The ratio of physicians and hospitals to the total population is similar to those in a number of other countries in the region, but considerably below those of Europe and North America. Most healthcare personnel and facilities are concentrated in urban areas, and periodically, there have been significant migrations of physicians and nurses to the United States. The Philippines has a dual healthcare system consisting of Western biomedicine and traditional medicine. The modern system is based on the germ theory of disease and has scientifically trained practitioners. The traditional approach assumes that illness is caused by a breach of taboos set by supernatural forces. It is not unusual for an individual to alternate between the two forms of medicine. If the benefits of modern medicine are immediately obvious, then they are usually accepted. However, if there is no immediate cure or result, the impulse of many Filipinos to turn to a traditional healer is often strong. In the past, hospital equipment often has not functioned properly because there were not enough technicians capable of effectively maintaining the supply. However by 2000, the Department of Health had apparently addressed at least part of the problem through the establishment of centers for the repair and maintenance of hospital equipment. Life expectancy in the Philippines has increased over the last several decades and infant deaths have dropped significantly, but again, mortality rates are still higher than those of Western nations. Like many other locales around the world, in the Philippines great healthcare disparities exist between urban and rural areas. Immunization shots for infants and other preventative measures are more prevalent in urban settings than rural, and even though the Department of Health has attempted to develop universal levels of minimum care, the more remote areas inevitably received less atten-
tion. While medical treatment has improved and services have expanded, pervasive poverty and lack of access to family planning detracts from the general health of the Philippine people. Much of the population continues to exist below the poverty line, and a high rate of childbirth tends both to deplete family resources and be injurious to the health of the mother. The main general health hazards are pulmonary, cardiovascular, and gastrointestinal disorders. Although relatively few Filipinos have been infected with AIDS, concern about the disease has caused authorities to give it considerable attention. Since the first cases of HIV/AIDS were reported in 1984, 1,515 HIV infections, including 508 AIDS cases and 196 HIV/AIDSrelated deaths, had been reported by June 2001. Overall, the epidemic in the Philippines has been classified as low. As of January 2004, the National Epidemiology Center of the Department of Health recorded 1,979 cases of individuals with HIV/AIDS of which 1,343 (68 percent) were asymptomatic and 636 (32 percent) were AIDS cases at the time of the report. Of the total AIDS cases, 257 (40 percent) had already died as a result of AIDS-related complications. indonesia Indonesians’ greater access to education over the past few decades has translated into an increased adherence to modern forms of healthcare. Life expectancies have risen in many areas and in those same areas the quality of life has improved. However, the distribution of resources for health maintenance and improvement in Indonesia remains unequal. The poor, rural, and uneducated classes generally suffered much higher mortality rates than their more educated counterparts. The overall number of healthcare professionals increased during the period, but many are concentrated in urban areas. Likewise, the better equipped urban hospitals tend to have more physicians and higher central government spending per bed than hospitals in the rural areas. Community and preventative health programs have become a key component of Indonesia’s healthcare system. Community health services are organized in a three-tier system with community health centers at the top. Usually staffed by a physician, these centers provide maternal and child healthcare, general outpatient and preventative healthcare services, pre- and postnatal care, immunization, and communicable
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disease control programs. Specialized services are sometimes available at some of the larger clinics. Second-level community health centers include health subcenters consisting of small clinics and maternal and child health centers that are staffed with between one and three nurses and visited weekly or monthly by a physician. The third level of community health services are village-level integrated service posts. These posts are not permanently staffed facilities, but are monthly clinics maintained on donated land, in which a visiting team from the regional health center reinforces local health volunteers. In general, although the community health situation has improving slightly in Indonesia over the last 20 years, the provision of community services remains low by the standards of developing countries. australia In Australia, the government, through the Department of Health and Ageing, sets national health policies and subsidizes health services provided by state and territory governments and the private sector. Total expenditure on health by all levels of government and the private sector currently account for almost 10 percent of Australia’s Gross Domestic Product. Like other countries, Australia faces growing pressures on health funding because of the aging of the population, technological changes, and increasing patient expectations. The Australian Government funds universal medical services and pharmaceuticals, and gives financial assistance for public hospitals, residential aged care facilities, and home and community care for the elderly. It is also the major source of funds for health research, and provides support for training health professionals and financial assistance to students. State and territory governments have primary responsibility under the Constitution for providing health services, including most acute and psychiatric hospital services. The states and territories also provide a wide range of community and public health services, including school health, dental health, maternal, and child health, occupational health, disease control activities, and a variety of health inspection functions. The main health responsibilities of local governments in Australia are in environmental control such as garbage disposal, maintenance of clean water, and health inspections. Local government also provides a range of home care and personal preventive services, such as
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immunization. A universal system of health insurance was introduced in the 1980s and is funded, in part, through a tax on income. The system’s three main functions are to cover the cost of medical services, pharmaceuticals, and public hospital care. Under Medicare, all permanent Australian residents are entitled to free public hospital care when choosing to be public patients. Doctors appointed by the hospitals provide the medical treatment. State and territorial governments provide public hospital services and work closely with the Australian government and professional bodies to ensure that the quality of care and appropriate standards are maintained. Australians may elect to be treated as private patients in public hospitals or to use private hospitals. In the private sector, patients can choose to pay directly for medical costs or use private health insurance. The Australian government also subsidises medical, pharmaceutical, and hospital services for veterans and war widows under similar plans administered by the Department of Veterans’ Affairs. Private hospitals provide about a third of all hospital beds in Australia. Private medical practitioners provide most out-of-hospital medical services and perform a large proportion of hospital services alongside salaried doctors. Private practitioners provide most dental services and allied health services such as physiotherapy. About half of all Australians are covered by private health insurance. Forty-three percent of the population are covered by hospital insurance for treatment as a private patient in both public and private hospitals. In almost all cases, coverage also extends to ancillary, nonmedical services provided outside of the hospital or clinical setting such as physiotherapy, dental treatment, and the purchase of eye glasses. Six percent of the population are covered for ancillary services only. The federal government is seeking a better balance between public and private sector involvement in the health sector by encouraging people to take out private health insurance, while preserving Medicare as the universal safety net. Australia works with international organizations, including the World Health Organization (WHO) and the Organisation for Economic Co-operation and Development (OECD), health ministries in other countries, and with independent research institutes to prevent and control the spread of disease, set international health standards, and support general health promotion activities. International involvement allows
Australia and other countries to learn from each other’s experiences and also enables Australia to contribute to the international development of health policy. Australia places a special emphasis on the Asia Pacific region, collaborating with international and regional organizations and ministries of health on issues that affect neighboring countries as well as Australia’s health policies. Australian academic institutions and health agencies offer international consultant services, on-site training programs, and work placements to strengthen health sector capacity, particularly in the region. Medicare Australia also works with the World Bank, AusAid, and the WHO to provide international consultant services in a range of areas including the development and management of secure online health business solutions; health system financing; health insurance administration; health information systems; pharmaceutical systems design and operations; and training and institutional development. new zealand AND Papua New Guinea New Zealand has a parallel system of public and private health services. Public healthcare is subsidized by the New Zealand government, while private healthcare is paid for by the individual. Individuals who can afford to pay for private health insurance do so, while those who cannot use the public health system. Both systems are of high quality, but there are some advantages to having private health insurance. In New Zealand, health problems are essentially divided into two categories: those associated with accidents and those that are not. Health problems that arise out of an accident are subsidized by the New Zealand government through the Accident Rehabilitation & Compensation Insurance Corporation. The Corporation makes payments to individuals who have suffered injury or disability as the result of an accident. If the individual has health needs or problems that are not related to an accident, then the medical and healthcare required for that individual is still heavily subsidized by the New Zealand government, but not through the Corporation. Regardless, permanent residents of New Zealand are covered under the country’s public health system one way or another. There are public hospitals and private hospitals in New Zealand. Public hospitals are available to any New Zealand resident, while private hospitals are available to anyone who has paid private health insur-
Healthcare, Europe
ance premiums, regardless of whether that person is a permanent resident or citizen of New Zealand. The primary advantage of having private health insurance is the individual’s ability to receive immediate care at a private hospital while avoiding waiting lists at public hospitals for nonurgent medical situations. Under the public health system, there is no charge for outpatients or overnight visits for New Zealand residents. New Zealand has a reciprocal arrangement with other countries whereby no charge is applied to nonresidents of New Zealand. Otherwise, a nonresident of New Zealand is charged a minimum rate per day for a hospital visit unless their injury is the result of a motor vehicle accident, in which case there is no charge. For New Zealand permanent residents and citizens who suffer injury or disability as the result of an accident, applications may be made to the Accident Rehabilitation and Compensation Insurance Corporation for either loss of earnings due to disability or for the costs of ongoing medical treatment. The claim for loss of earnings due to disability can be made at a rate of 80 percent of the individual’s salary. Notwithstanding the public health system subsidies, individuals may choose to purchase their own private health insurance, which they can use to supplement any health services that they receive from the government under the public health system. Under the private healthcare system, anyone may buy health insurance. Those who choose to do so pay an annual premium to an insurance company, and all or part of the individual’s health expenses for treatment at private hospitals are paid for by the insurance company. Premiums are set at different levels that coincide with the amount of coverage that the individual requires. Papua New Guinea’s population has suffered significant declines in living standards in recent years due to worsening economic performance. Although the country does not exhibit the widespread abject poverty present in some developing countries, poor health and social indicators show that poverty is a real problem. Papua New Guinea’s main social tenets, such as life expectancy and maternal and child mortality rates, show improvements over the last few decades, but are still well below the averages for lower middle income countries. Papua New Guinea still has limited primary healthcare. Infectious diseases claim many lives, and there are serious public health risks from endemic diseases such as malaria, and an
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emerging HIV/AIDS epidemic. An estimated 1.7 percent of people in the country carry the virus. See Also: Australia; China; Chinese Medicine, Tradition-
al; Japan; New Zealand.
Bibliography. Australian Government, AusAID, www. ausaid.gov.au (cited October 2006); Australian Government, Department of Foreign Affairs and Trade, www. dfat.gov.au/facts/health_care.html (cited October 2006); Australian Government, Department of Health and Aging, www.health.gov.au (cited October 2006); “The Body: HIV and AIDS in Japan,” www.thebody.com (cited October 2006); “Country Studies,” www.countrystudies.us (cited October 2006); Kundig Associates, “New Zealand’s Health System,” www.migrate.co.nz/Info/info5.htm (cited October 2006); Milton J. Lewis, The People’s Health: Public Health in Australia, 1950 to the Present (Praeger, 2003); Fadia Saadah, and James Knowles, The World Bank Strategy for Health, Nutrition, and Population in the East Asia and Pacific Region (World Bank Publications, 2001).
Ben Wynne, Ph.D Gainesville State College
Healthcare, Europe As in other parts of the world, lifestyle-related health factors and socio-economic concerns in the European Union (EU) are multi-dimensional and linked to a number of major health problems. The EU is dedicated to dealing with these factors through comprehensive health promotion in various settings such as schools, workplaces, families, and local communities. Communicable diseases such as tuberculosis, measles, and influenza also represent a serious risk to human health in the EU, and contribute to about one-third of all deaths occurring globally. Communicable diseases do not respect national borders and can spread rapidly if actions are not taken to combat them. New diseases emerge and others develop drugresistant mutations such as multidrug resistant tuberculosis, and methicillin-resistant Staphylococcus aureus. In addition to trying to address these concerns, EU researchers are also studying chronic conditions such as cancer, heart diseases, and allergies.
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lifestyle factors In Europe, six out of the seven most important risk factors for premature death (blood pressure, cholesterol, body mass index, inadequate fruit and vegetable intake, physical inactivity, excessive alcohol consumption) relate to how Europeans eat, drink, and move. A balanced diet and regular physical activity, along with refraining from smoking, are important factors in the promotion and maintenance of good health. Moreover, those with lower incomes and education level usually are the most affected by these factors, and therefore are at the greatest risk. Excess weight and obesity are increasing at an alarming rate in Europe. Obesity is one of the most serious public health problems in Europe because it increases significantly the risk of many chronic diseases such as cardiovascular disease, type 2 diabetes and certain cancers. These diseases represent the greatest burden to healthcare systems in Europe and are the leading cause of mortality in EU member states as well as worldwide. The increase of childhood obesity is of particularly concern. Lifestyle factors, including diet, eating habits, and levels of physical activity and inactivity, are often adopted during the early years of life. As childhood obesity is also strongly linked to obesity in adulthood, the best time to address the problem is early in life. Maintaining normal weight is challenging, particularly in the modern era with its abundance of high calorie foods designed to be rapidly prepared and consumed. The environments that many people live in are conducive to obesity. In many parts of the EU, there is an abundance of energy-rich food that is often poor in nutrients, and at the same time, there are decreasing opportunities for physical activity on the part of the population both at work and during leisure time. Food portion sizes also grow year by year, even though people actually need less and less energy due to the shift toward sedentary lifestyles. Tobacco is the single largest cause of avoidable death in the EU, accounting for over half a million deaths each year. In the 21st century, it has been estimated that 25 percent of all cancer deaths and 15 percent of all deaths in the EU could be attributed to smoking. In order to curb this epidemic, the European Community is actively developing a comprehensive tobacco control policy that includes legislative measures; the mainstreaming of tobacco control into a range of other Community policies; making sure that the pioneering role of the
European Community in many tobacco control areas produces an impact beyond the EU; and establishing the community as a major player in tobacco control at a global level. Alcohol is also key health factor in European countries that requires constant attention. Europe is the continent where per capita alcohol consumption is the highest in the world. In established market economies such as the EU member states the burden of disease and injury attributable to alcohol is estimated to be almost 10 percent. Combating alcohol-related injuries or health problems therefore is a public health priority in many Member States, and at the EU level. It is not only health consequences in a narrow sense that raise concerns, but also alcohol-related social issues such as violence, crime, domestic problems, social exclusion, difficulties in the workplace, and particularly drunk driving. All of these are areas require political action, and all are being addressed by the member states to one degree or another. In addition, there is agreement among the member states that, beyond individual national efforts, a joint alcohol strategy at the community level should be maintained. Thousands of acute drug-related deaths are recorded each year throughout the EU, mostly involving young people. National statistics on drug deaths usually refer to acute deaths directly related to drug consumption or overdose, although differences in definitions exist from nation to nation. The actual figure is thought to be considerably higher because of underreporting of deaths related to overdoses and also because of deaths indirectly related to intravenous drug use such as AIDS and other infectious diseases. In addition, drug use as it relates suicide, accidents and violence often goes unreported in drug fatality statistics. Some more inclusive studies have indicated that all of these fatalities could increase the real number of deaths that can be related to drugs as much as three-fold. Various public and private initiatives by EU member states have been designed to decrease risk, although some remain controversial. Needle exchange programs, substitution programs with methadone or related substances for opiate users, and low-threshold and outreach services (for instance walk-in clinics for addicted people irrespective of current drug use) are thought to have had a positive impact in helping decrease the number of drug-related deaths in the EU per annum, although the work is ongoing. Overall, the
number of drug-related fatalities has stabilized and even decreased in some areas in recent years. Cannabis remains the most commonly used illegal substance in Europe, with a high level of variation between countries. Recent studies among 15-year-old students suggest that lifetime prevalence varies from under 10 percent to over 30 percent compared to 1 percent to 10 percent for cocaine (15–34 years). It is difficult to define clear trends that apply to the EU as a whole with regard to drug usage. The use of other drugs is much less common, both among young people and in the general population. Recent use of amphetamines or cocaine is generally found in less than 1 percent of adults. Overall, the increase in the use of ecstasy, which began to occur during the 1990s appears to have stabilized, with only a few countries still reporting an upward trend. Use of synthetic drugs by young people in social settings remains a major concern. Drug users are overrepresented in prisons compared with the general population. Estimates of lifetime prevalence of drug use among prisoners vary between 22 percent and 86 percent, depending on the prison population, detention facility, and country. If the rate of drug use in the EU as a whole is between four and seven cases per 1,000 population aged 15–64, this translates into between 1.2 and 2.1 million problem drug users, of whom around 1 million are active injecting drug users (IDUs). Injecting drug use seems to have fallen since the 1990s; however, it remains a significant concern. AIDS/HIV risk Drug injectors are at very high risk of experiencing adverse consequences such as HIV/hepatitis C virus (HCV) infections. The HIV epidemic is spreading rapidly in some of the new EU countries and their neighbors. Where HIV prevalence has remained high among IDUs, sustained prevention efforts are important to prevent transmission to new users, sexual partners and from mother to child. Injecting drugs use can be a route for the transmission of a range of other infectious diseases such as botulism and tuberculosis. The Directorate General (DG) of Health and Consumer Protection deals with the public health aspects of illegal drug use (as well as legal drugs misuse or abuse), especially prevention programs, education, risk reduction, treatment and the raising of awareness. It cooperates with other agencies with regard to ancillary services of the Commission that deal with the problems created by
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drug use such as smuggling, overall increases in crime, and any special needs of law enforcement in these areas. It also cooperates with the European Monitoring Centre for Drugs and Drug Addiction (EMCDDA) in Lisbon and with international organizations, such as the World Health Organization (WHO) and the Pompidou Group of the Council of Europe. Socioeconomics and health Socioeconomic factors continue to serve as leading indicators of the quality of health and healthcare in the EU. On average, EU citizens with better jobs, more education or higher incomes have better health and live longer. Differences in life expectancy of five years or more can be found between the most advantaged and least advantaged groups. Such gradients exist within all European countries for many diseases and other general factors contributing to poor health. Limited access to proper healthcare lowers the ability of huge numbers of EU citizens to achieve their potential. As a result, the EU has adopted policies aimed at reducing health inequities. The EU hopes to improve the quality of healthcare afforded the disadvantaged to that of the most advantaged classes in society, and thereby ensure that the health needs of the most disadvantaged are fully addressed as quickly as possible. At the EU level this involves efforts to produce economic, employment and social policy designed to strengthen the European economy and at the same time ensure universal social protection; increase the support of the economies and health infrastructures of countries and regions of the EU which are lagging behind or have special needs; and promote research to identify the causes of socioeconomic health inequalities and develop and evaluate measures to combat them. An increasing number of patients in the EU receive treatments based on biological substances donated by others. These include blood, tissues, cells, and whole human organs. Such substances are of high therapeutic value, but they also carry risks for the recipients, in particular the risk of transmission of communicable diseases. The community contributes to reducing these risks by adopting legislation on the quality and safety of these substances, and by funding various research projects in this area. Donation of blood and plasma in the EU provides the source material for a wide range of essential, often life-saving, therapeutic substances.
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Their universal use in medicine requires the highest achievable level of safety. Human tissues and cells are increasingly used in transplantation, as well as tissue engineering and cell therapy. Due to their biological origins, tissues and cells also carry risks for the transmission of diseases, which obviously poses a concern for those in need of transplants. In the EU, by far the biggest problem with regard to transplants or the use of other biological material is the low number of organ donors, which naturally leads to a severe scarcity of organs. Recently, and in another ongoing efforts, the community has taken steps to help improve the situation by fostering new initiatives at the EU level related to organ donation and the management of biological materials. The European Center for Disease Prevention and Control (ECDC) is an EU agency that has been created to help strengthen Europe’s defenses against infectious diseases, such as influenza, SARS and HIV/ AIDS. In the modern era infectious disease outbreaks spread internationally and with alarming speed. Cooperation between national disease control agencies is vital to the process of meeting the increasingly complex health challenges of the 21st century. As a result, the European Parliament and Council passed in 2004 the appropriate legislation creating the ECDC. The organization’s mission is to identify, assess and communicate current and emerging threats to human health posed by infectious diseases. In order to achieve this mission, ECDC works in partnership with national health protection bodies across Europe to strengthen and develop continent-wide disease surveillance and early warning systems. By working with experts throughout Europe, the ECDC seeks to pool Europe’s health knowledge and, in so doing, to develop authoritative scientific opinions about the risks posed by current and emerging infectious diseases. The ECDC is strategically located in the Tomteboda building in the heart of Stockholm’s Karolinska Institute Campus area, near to the Swedish Institute for Infectious Disease Control. food safety in europe Food safety is one of the EU’s leading areas of healthrelated activity. Experience shows that to ensure the safety and reliability of food within the EU and worldwide, the entire food chain has to be evaluated and maintained at an acceptable level. The EU has laws
covering how farmers produce food (including what chemicals they may use when growing plants and what they may feed their animals), how food is processed, how food is sold, and what sort of information is provided on food labels. The EU also has laws regulating the safety of food imported into the EU as well as extensive procedures that allow for the tracking of food products coming into member states. The work of keeping the EU’s laws on food safety up to date is complemented by the Health and Consumer Protection Directorate-General officials in the Food and Veterinary Office (FVO) based in Grange, Ireland, whose main job is to verify, through inspections that EU countries and other countries exporting food to the EU observe certain rules and regulations. Their work includes working with international organizations and the EU’s trading partners on food and farming issues and running the EU’s “rapid alert” system on food and feed safety. Within the EU, having seen the advantages of separating risk assessment from risk management, the European Commission reassigned the work of risk assessment on food safety to a relatively new agency, the European Food Safety Authority (EFSA), in Parma, Italy. The Commission remains responsible, however, for overall risk management. The EU and the United States both have very high standards of food safety, although somewhat different approached to dealing with certain problems related to food and the food supply. In the United States, the Delegation of the European Commission to the United States in Washington works mainly with the U.S. Food & Drug Administration (FDA) within the Department of Health and Human Services, and with the U.S. Department of Agriculture. It also maintains a dialogue with the American food industry and with public interest groups and is available to answer questions that can benefit trade in both directions across the Atlantic Ocean. public health Threats to public health are a permanent cause of concern for health authorities all over the world. In order to be prepared to face threats likely to affect public health in the EU, the Commission collaborates with EU member states to develop preparedness activities and plans. A generic preparedness plan has been issued by the commission to address generically different types of health threats. More specific plans
have been issued both at national and at the community level to address the issues of pandemic influenza, SARS, smallpox, and bioterrorism. Under new programs developed in the first decade of the 21st century, actions and support measures in the field of noncommunicable diseases have been focused on developing strategies and mechanisms for preventing, exchanging information on, and responding to noncommunicable disease threats, including gender-specific health threats and rare diseases. During the late 1990s, a significant debate developed over how to organize surveillance for infectious diseases in the EU culminating in the decision by the European Parliament and Council to create a plan for a decentralized health networks as opposed to constructing a large central European surveillance center. According to the plan, institutions in member states received funding to organize European surveillance for one or more related infectious pathogens. Using an approach based on risk and hazard analysis, studies identified common control points and concluded that the networking approach was successful but needed augmentation under a framework of improving existing organizational, financial, and legal factors. An important contributor to the networks’ success has been the high level of participation by national public health institutes, in large part because these institutions have had an active role in running the networks themselves. The networks’ start-up costs have been low because existing physical infrastructures in the participating institutions are utilized. These networks, combined with European infrastructures such as the European Program of Intervention Epidemiology Training, and publications such as Eurosurveillance and Eurosurveillance Weekly, have accelerated the development of the elements needed for effective control of communicable diseases at the European level. For example, surveillance systems and epidemiological response capacities have been improved, surveillance and laboratory methods are increasingly cross-referenced, published forums for sharing experiences related to control measures now exist, and a group of highly trained field epidemiologists has been formed and is functioning. In the modern era, health systems and health policies across the EU have become more interconnected than at any other time in history. This is the case because of a number of factors, including the in-
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creased mobility of patients and professionals around the EU, growing common public expectations across Europe, greater dissemination of new medical technologies and techniques, and the enlargement of the union itself. This increased interconnection raises many health policy issues, including those related to the quality of, and access to, cross-border care; information requirements for patients, health professionals and policy makers; the nature of cooperation on health matters among the member nations; and the ability to reconcile national policies with the obligations of the EU’s internal concerns. Rights to healthcare are recognized in the Charter of Fundamental Rights of the EU, and high-quality health services have become a priority issue for European citizens. The European Court of Justice has made it clear that treaty provisions on free movement apply to health services, regardless of how they are organized or financed at the national level. However, many healthcare stakeholders have asked for greater clarity with regard to what community law means as it applies to health services. The European Commission therefore continues to develop a community framework for safe, high quality and efficient health services by reinforcing cooperation between member states and by ensuring equal application of Community law to health services and healthcare. In general, the commission sets the standard for health functions based on a foundation of legal certainty and the pledged support of member states. Legal certainty is critical tenet of the process as it serves to significantly boost the confidence of citizens as well as national and local health professionals. Across Europe, there has traditionally been a need to address the wider application of European Court of Justice rulings regarding treaty provisions on the free movement of patients, professionals and health services. This focuses in particular on cross-border care, although cross-border care has consequences for all health services, whether provided across borders or not. Of equal import is the support for member states in areas where European action can add value to national action on healthcare services. Discussions about “patient mobility” at the EU level were prompted in the late 1990s after several judgments of the European Court of Justice. Until then, the mechanisms within the EU enabling patients to receive treatment abroad (other than patients paying for the treatment themselves) were limited. However, one
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important ruling made it clear that as health services are provided for remuneration, they must be regarded as services within the meaning of EU Treaty and thus relevant provisions on the free movement of services apply. On the basis of this and subsequent decisions, any nonhospital care to which individuals are entitled in the individual’s own member ��������������������������� state��������������� may be sought in any other member ������������������������������������� state������������������������� without prior authorization, and be reimbursed up to the level of reimbursement provided by individual’s own system. This also extends to hospital care. To track the potential needs of the EU along these lines, the European Commission has launched public health reporting projects that will continue well into the 21st century. The reports deal with topical public health issues that provide the basis for further policy developments. The aim of launching the effort was to bring together top European scientists and officials in the field of public health and statistics from all EU countries so that they could contribute collectively to the creation of the European Health Information and Knowledge System. The dissemination of health information to different users throughout the EU has changed dramatically over the last few decades. A great deal of effort has been put into the compilation of data, the development of indicators and new technologies for the analysis and presentation of health data, and the evaluation of the effectiveness of health reporting. However, health reporting traditionally has been a public health issue discussed widely among health professionals at the local, regional and national levels. The objective of the EU Public Health Program is to provide member states with appropriate health information in order to support their national health policies. For a growing number of member states, health status analysis and reporting has become an important instrument to support national health policy cycles. Basically, such health reporting supports the preparation, planning, implementation and evaluation of health policy including programs and at the community level and at the member state level. General health policy within the EU deals with priority settings for health policy and with the past and possible future effects of health policy programs. european health goals One of the European Commission’s aims is to produce comparable information on health and health-
related behavior of the populations of member states, and on diseases and their effect on health systems as a whole. This information is based on common indicators agreed to by member states. Most of the research and policy supported by the Program of Community Action in the Field of Public Health are related to the development of indicators in various health fields in order to facilitate and improve the collection of data. An initial set of European Community Health Indicators (ECHI) has been produced and widely disseminated. The work is ongoing with existing indicators undergoing constant scrutiny, and with new indicators periodically being added to the mix. The objective is to produce as complete a list of ECHIs as possible to serve as the foundation for the European Health Information and Knowledge System. This and other related programs have also funded the production of regular European health reports that disseminate critical information to member states. Currently, and most likely for the foreseeable future, work on indicators and data collection will be conducted in coordination with a variety of organizations and task forces in hopes of creating a prototype for future health monitoring. The tasks of those involved will cover all five phases of data management: the analysis of data needs in their respective areas; definition of indicators and quality assurance; technical support for national efforts; data collection at the EU level; reporting and analysis; and the promotion of the results. Within this framework collaboration and close coordination with Eurostat and its partnership groups is a very important part of the process. The objective is to complete the ECHIs list that will serve as a foundation for the European Health Information and Knowledge System. The ECHI project has already developed a comprehensive list of indicators, in close cooperation with many of the other projects under the program. As of June 2006, the general list contained approximately 400 items or indicators, although there is a push among some in the European Commission to develop a shortlist in order to prioritize needs and streamline data collection among the member states. To this end, ECHI has undertaken the task of selecting the indicators for the shortlist in close collaboration with the project leaders and the Commission departments that are affected.
Healthcare, South America
See Also: European Association for the Study of Obesity
(EASO); European Public Health Alliance (EPHA); European Public Health Association (EUPHA). Bibliography. Country Studies, www.countrystudies.
us (cited October 2006); European Centre for Disease Prevention and Control (ECDC), www.ecdc.eu.int (cited October 2006); Richard Freeman, The Politics of Health in Europe (Manchester University Press, 2000); Wilhelm Kirch, Public Health in Europe: 10 Years European Public Health Association (Springer, 2004); Martin McKee, Laura MacLehose, and Ellen Nolte, Health Policy and European Union Enlargement (Open University Press, 2004); Elias Mossialos, Anna Dixon, and Josep Figueras, eds., Funding Health Care: Options for Europe (Open University Press, 2002). Ben Wynne, Ph.D. Gainesville State College
Healthcare, South America Because it covers a vast area and includes an estimated population of almost 400 million, healthcare on the South American continent varies widely. In some areas, great strides have recently been made in improving health and healthcare systems, while in other, more primitive areas, there are few, if any, significant healthcare options. brazil Brazil is by far the largest and most populous country in South America. Its strong industrial and agricultural sectors make it South America’s leading economic power. The Brazilian constitution of 1988 and the Organic Health Law of 1990 universalized access to medical care, unified the public health system supported by the Ministry of Health and the National Institute for Medical Assistance and Social Security, and decentralized the management and organization of health services from the federal to the state and municipal levels. Many of the sweeping health reforms that were initiated during the period attempted to extend coverage to those outside the social security system. The constitution grants all Brazilian citizens the right to free medical assistance from public as well
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as private providers reimbursed by the government. While the public domain oversees basic and preventive healthcare, the private nonprofit and for-profit healthcare sector delivers the bulk of medical services, including government-subsidized inpatient care. This publicly financed, privately provided health system continues to intensify its focus on high-cost curative care, driving hospital costs steadily upward. Therapeutic treatment in hospitals tends to dominate funding at the expense of health promotion and disease prevention programs. Not only have basic and preventive health services for the entire population diminished, but the public health system also subsidizes expensive, high-technology medical procedures that consume 30 to 40 percent of health resources and often end up being used to attend affluent segments of the society. Although states and municipalities have rapidly acquired more responsibility in administering health funds and facilities, the federal government in Brazil retains the role of financing public health outlays. As stipulated by the constitution, government subsidies for health services are derived from the social security budget, which is predominantly based on earmarked taxes and contributions from employee payroll and business profits. Private sources finance half of total health expenditures. Perceptions of inefficiency in the government reimbursement schedule and deterioration in service quality of the public health system spurred a rapid growth in the private financing of healthcare beginning in the 1980s, particularly in economically advanced areas. The private sector covers roughly 20 percent of the Brazilian population and consists of several hundred firms offering four principal types of medical plans: private health insurance, prepaid group practice, medical cooperatives, and company health plans. The group medical plans rank Brazil as the largest health maintenance organization (HMO) provider in Latin America. bolivia From the mid-1970s to the mid-1980s, Bolivia made slow but steady progress in improving the health conditions of its population. Overall life expectancy rose, and the mortality rate dropped for both adults and children. Despite these improvements, however, Bolivia’s health indicators remain among the worst in the western hemisphere. Health conditions vary sig-
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nificantly across regions, within regions, and by urban or rural residence. Infants in rural areas have a far greater probability of dying than those in urban settings. Similarly, mortality rates for rural children up to the age of 5 are nearly double those found in children residing in the cities. Studies also note disparities in rates among ethnic groups. Rates are highest among children of mothers who speak only an indigenous language, intermediate among bilingual mothers, and lowest among monolingual Spanish-speaking mothers. Bolivian health specialists also confront a variety of diseases that affect the general population. In the past, the government has organized mass campaigns in an effort to deal with malaria epidemics, and relatively aggressive vaccination programs to combat yellow fever and jungle fever. Pulmonary tuberculosis and silicosis remain serious concerns. Toward the end of the 20th century, the government began restructuring its healthcare system to allow for more effective delivery. Bolivia’s health network traditionally had been characterized by a high degree of fragmentation and duplication of services. Although the Ministry of Social Services and Public Health had overall responsibility for the system, 10 separate social security funds offered health services to members insured through their place of employment. In addition to wasting scarce resources, this approach had a heavy urban bias. The new approach called for a unified system under the control of the Ministry of Social Services and Public Health, with emphasis on preventive rather than curative medicine. chile By the early 1970s, the state-run health programs in Chile faced a financial crisis, and as a result, policy makers in the 1980s redesigned the nation’s existing healthcare institutions. The end result was a system that contains essentially five components, the most prominent being the National System of Health Services (SNSS). The SNSS organizes and implements broad public health programs in areas such as inoculations and maternal-infant care. It provides periodic preventive medical care to all children less than 6 years of age not enrolled in alternative medical plans. Through this program, which has broad national coverage, low-income mothers can receive supplemental nutritional assistance for their children and for themselves if they are pregnant or nursing.
As a result, the incidence of moderate-to-severe childhood malnutrition among those participating in the program was reduced to negligible levels. While the SNSS remains the largest healthcare provider in the country, other components of the Chilean health system include the National Health Fund, the Security Assistance Institutions, private insurance companies, and private medicine, which includes both private hospitals and clinics. In the 21st century, Chilean health indicators are much closer to those of industrial nations than to those of the developing world. The SNSS still handles the vast majority of all medical visits and almost all births occur with professional assistance in hospitals or maternity clinics. In rural areas where women might need to travel greater distances to give birth, they can spend the last 10 to 15 days of pregnancy in special hostels. Inoculations of infants and children are virtually universal for tuberculosis, diphtheria, pertussis, tetanus, poliomyelitis, and measles. Ecuador In Ecuador, both the public and the private sectors provide health services. Most public healthcare comes under the direction of the Ministry of Public Health, although the armed forces, the Ecuadorian Social Security Institute (IESS), and a number of other autonomous agencies also contribute. The Ministry of Health covers the vast majority of the population and the IESS approximately 10 percent. The Ministry of Public Health has organized a multitiered system of healthcare in Ecuador. Auxiliary healthcare personnel staff posts that serve small rural settlements with populations of less than 1,500, and more significant health centers staffed with healthcare professionals service communities of 1,500 to 5,000 inhabitants. Provincial and national hospitals are located in the largest cities. By the turn of the 21st century, there were more than 2,000 health establishments nationwide with the Ministry of Public Health running well over half of those. However, the limited numbers of healthcare professionals in the country and their lack of training continues to hamper public healthcare efforts. These deficiencies are most apparent with regard to medical specialists, technicians, and nurses. Infant mortality rates in Ecuador have improved over the past few decades although recent rates re-
main a serious concern, and infant mortality can vary greatly by region and socioeconomic status. Childhood mortality rates have generally decreased as a result of immunization campaigns and attempts to control diarrheal diseases. In Ecuador, the main causes of death among adults are motor vehicle accidents, coronary heart disease, cerebrovascular disease, cancer, and tuberculosis. A number of tropical diseases also concern health officials, including onchocerciasis (river blindness) which is found in a number of isolated areas, Chagas disease (a parasitic infection), leishmaniasis (also a parasitic infection), and malaria. Uruguay Uruguay has been described as South America’s “first welfare state” due to its pioneering efforts in the fields of healthcare as well as public education and social security. Starting with the progressive reforms of the early part of the 20th century, the state has taken a leading role in providing healthcare, particularly to the lower classes, although private medicine remains the preferred option of the middle and upper social divisions. During the first half of the 20th century, Uruguay and Argentina led Latin America in advanced standards of medical care, and into the 1990s, the University of the Republic’s medical school had a high international reputation and attracted students from other countries in South America. However, in recent years, standards of care in public hospitals and clinics have been adversely affected by budget restrictions. Uruguay’s welfare state has declined a great deal in the standards of protection that it affords the mass of the population. Still, spending on healthcare equipment is significant and health standards in general in Uruguay remain relatively high when compared to other countries in Central and South America. A significant effort has been made to increase the proportion of infants receiving inoculations against diseases such as whooping cough and measles, and the average life expectancy at birth is around 70 years for men and 76 years for women, only slightly behind Chile and Argentina. The leading causes of death in the country are circulatory disease, tumors, trauma, respiratory disorders and infections, perinatal complications, infectious diseases, suicide, and cirrhosis of the liver.
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colombia In the new century, most Colombians enjoy significantly better healthcare and nutrition than previous generations. The country had risen from the ranks of the poorest nations in Latin America during the 1950s and 1960s to an intermediate status based on leading health and economic indicators. These improvements are the result of rapid socioeconomic modernization, which was accompanied by improvements in education and working conditions; greater access to urban healthcare facilities; running water and sewerage systems; and, in general, more modern attitudes toward sexuality, medicine, disease prevention, nutrition, and exercise. There were also explicit state policies designed to improve access to and availability of healthcare and medical services. Beginning in the 1980s, Colombia developed a public and private infrastructure of hospitals and other healthcare facilities, a widespread network of medical schools, and a specialized set of institutions responsible for formulating and handling public policy in the health sector. Despite general improvement, the benefits of better healthcare are not evenly distributed among the different strata of Colombian society, or from region to region. In urban areas, the upper and middle classes and many blue-collar workers enjoy above-average health conditions. In contrast, the rural and urban poor suffer from higher mortality and morbidity rates because of inadequate or inaccessible medical services, housing, and food. As a result, Colombian health policy-makers continue to be faced with the task of improving services to the least-favored segments of society, while improving the quality and overall performance of the national healthcare system Venezuela Venezuela has had, by Latin American standards, an enviable record in health and social welfare and one that has shown tremendous progress through the years. In 1940, the overall life expectancy at birth was 43 years. By the end of the century, that figure had risen to over 70 years (71 years for males and 77 for females, both among the highest in Latin America). This reflects generally improving health conditions in recent decades, and the increase in preventive public health measures undertaken by the government. For example, successful inoculation programs have decreased the incidence of a number of contagious diseases.
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On the other hand, comparisons between causes of mortality 50 years ago and in the modern era show that Venezuela, a rapidly industrializing country, has become more prone to causes of death usually associated with urban and industrialized countries and a faster pace of life. These include heart disease, accidents, cancer, certain respiratory illnesses, and so forth. Infant mortality has also declined because of better public health measures, prenatal care, and national immunization campaigns. Overall, healthcare facilities have grown in number and in quality, and at the same time, the population had become more urban and better educated. There has been an increase in the number of medical facilities and personnel offering healthcare. Immunization campaigns have systematically improved children’s health, and regular campaigns to destroy disease-bearing insects and to improve water and sanitary facilities have all boosted Venezuela’s health. However, the availability of care in rural areas represents a gap in the healthcare delivery system. Doctors tend to concentrate in the large cities, especially Caracas, leaving many smaller provincial towns without adequate medical personnel. Private medical facilities, operated for profit, enjoy greater prestige than public institutions. Charitable organizations, especially the Roman Catholic Church, operate some health facilities. The bulk of the population, however, relies on the Venezuelan Social Security Institute, which operates its own hospitals, covering its costs out of social security funds. Peru Beginning in the early 1990s, Peru was hit by a cholera epidemic that highlighted long-standing healthcare problems in the country. A number of studies amply illustrate Peru’s vulnerability to disease and the uneven distribution of resources to combat illness. Most health facilities and the leading health facilities are concentrated in metropolitan Lima, followed by the principal older coastal cities. Whereas Lima has approximately one doctor for every 400 persons on average, and other coastal areas have a ratio of one doctor for every 2,000, rural areas consistently have only one doctor for about every 12,000 persons. The same levels of inequity apply with respect to hospital beds, nurses, and all the medical specialties. Even in the modern era, a significant portion of urban
residents and most rural Peruvians lack basic potable water and sewerage. As a result, the population has been exposed to a wide variety of waterborne diseases, which in turn further reflect the inequities evidenced in Peru’s healthcare system. The leading causes of death by infectious diseases have varied from year to year, but invariably, the principal ones are respiratory infections, gastroenteritis, common colds, malaria, tuberculosis, influenza, measles, chicken pox, and whooping cough. Many important health and social issues in Peru are interrelated with the country’s steadily worsening environmental conditions. The high levels of pollution in large sectors of Lima, Chimbote, and other coastal centers are the result of the unregulated dumping of industrial, automotive, and domestic wastes. The loss of irrigated coastal farmland to urban sprawl, erosion of highland farms, and the clear-cutting of Amazonian forest have all conspired to impoverish the nation’s most valuable natural resources and further exacerbate social conditions. Unfortunately, while Peru is endowed with perhaps the widest range of resources in South America, somehow they have never been coherently or effectively utilized to construct a balanced and progressive society. Argentina Argentina offers both a public and private healthcare system. About 18 million Argentineans have health insurance through their unions and go to clinics called obras sociales for medical care. About 4 million people from the middle and upper classes are privately insured. Some large private health insurance companies have their own hospitals. About a third of the population does not have health insurance, and of these, almost half are children. Those without health insurance go to public hospitals for treatment. These hospitals are equipped to handle emergencies but may not have the facilities for more involved forms of treatment. Government cuts to the public health system have left many poorer Argentineans without access to needed healthcare services. Although most areas have a safe water supply and, in general, healthy living conditions, in certain interior regions, particularly in the north, and in poverty-stricken areas in the cities, living conditions are far from ideal. Many homes in these areas have no running water, sewage system, or electricity, and there may be no healthcare facilities nearby. AIDS-
related diseases are growing, and cholera and tuberculosis have reappeared in some regions. Medical care in Buenos Aires is generally good, but care varies in quality outside the capital, and in some parts of Argentina, the hospitals do not have the most up-to-date equipment. Serious medical problems requiring hospitalization or perhaps even medical evacuation to the United States can cost thousands of dollars or more, and doctors and hospitals often expect immediate cash payment for health services. Like the rest of the world, South America has not escaped exposure to the HIV/AIDS epidemic. By far the largest and most populous country on the continent, Brazil suffers under a diverse epidemic that has penetrated all 26 states in the country. Although national HIV prevalence among pregnant women has remained low, a growing share of new HIV infections are among women, and those living in deprived circumstances appear to be disproportionately at risk of infection. In Brazil’s cities, the contribution of injecting drug use to HIV transmission appears to have declined due to a variety of programs designed to reduce the risk of exposure. Official estimates show that three-quarters of the estimated 200,000 drug injectors in Brazil now use sterile syringes. In Argentina, most new infections have been occurring during unprotected heterosexual intercourse, with increasing numbers of women acquiring HIV. The male-tofemale ratio among reported AIDS cases shrank from 15:1 in 1988 to 3:1 in 2004. Injecting drug use and unsafe sex between men continue to provide impetus to the spread of HIV in Argentina, especially in the urban areas of Buenos Aires, Cordoba, and Santa Fe provinces, where an estimated 80 percent of AIDS cases have occurred. When tested in the city of Buenos Aires, some 44 percent of drug injectors were HIV positive, while in other studies HIV prevalence of 7 to 15 percent has been found among men who have sex with men. HIV has penetrated rural parts of Paraguay, especially along the borders with Argentina and Brazil. Bolivia’s epidemic remains small and appears to be driven largely by commercial sex and sex between men, much of it concentrated in urban areas. Infection levels in groups of men who have sex with men have reached 15 percent in La Paz and almost 24 percent in Santa Cruz. A study in the city of Cochabamba has shown that 3.5 percent of the surveyed street youth were living with HIV, and most had been
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infected sexually. Sex between men appears to be a prominent factor also in Ecuador’s growing epidemic, where new reports of HIV cases have almost doubled in the last decade. In Colombia, HIV initially affected mostly men, so much so that they comprise 83 percent of all AIDS cases reported to the national health authorities to date. However, a significant proportion of men who have sex with men also maintain sexual relationships with women. As a result, increasing numbers of women are becoming infected. See Also: Argentina; Brazil; Peru. Bibliography. Anabela Abreu, et al., eds., HIV/AIDS in
Latin American Countries: An Assessment of National Capacity (World Bank, 2003); AVERT, www.avert.org (cited October 2006); Country Studies, www.countrystudies. us (cited October 2006); Cultural Profiles Project, www. cp-pc.ca/english/index.html (cited October 2006); Family Health International, www.fhi.org/en/index.htm (cited October 2006); Sonia Fleury, Susana Belmartino, and Enis Baris, eds., Reshaping Health Care in Latin America: A Comparative Analysis of Health Care Reform in Argentina, Brazil, and Mexico (IDRC, 2001); Transparency International, Global Corruption Report 2006: Special Focus: Corruption and Health (Pluto Press, 2006). Ben Wynne, Ph.D. Gainesville State College
Healthcare, U.S. and Canada While Canada and the United States had quite similar healthcare systems in the 1960s, the two neighbors now stand in marked contrast in terms of healthcare system provision and payment. The United States features a market-based system of delivery and payment, while healthcare delivery is organized in Canada by provincial governments, which also are responsible for most healthcare expenditures. One of the biggest differences between the two is that the United States is one of only a few industrialized countries not to guarantee healthcare for all of its citizens, while Canada represents an example of a country with universal healthcare guaranteed due to the heavy involvement of the government in providing funding for care.
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Although the United States’ healthcare system is largely characterized by private provision, federal and state governments still play a substantial role in providing the funding for healthcare services, especially via large national entitlement programs, Medicare, Medicaid, and State Children’s Health Insurance Program (SCHIP). Medicare provides direct payments from the federal government to private providers for physician and hospital services, and recently expanded to include funding for prescription drugs. Generally available to individuals over the age of 65, as well as certain other categories of people (such as those officially classified as disabled), Medicare and other public programs account for approximately 50 percent of all healthcare expenditures in the United States, and is funded via payroll taxes into a trust fund, one which is slated to run out of funds at some time in the 21st century without substantial overhaul of the program. government-sponsored programs Medicaid also provides direct payments from state and federal governments to providers, often via state Medicaid programs. While Medicaid eligibility is determined at the state level, this program is largely limited to poor, pregnant women, children, and elderly persons needing long-term care assistance. SCHIP generally covers children up to the age of 18 whose families make too much money to qualify for Medicaid but who are still considered “low income” according to state guidelines. A handful of states have extended SCHIP to all uninsured children in the state, regardless of family income. Other smaller government programs provide for direct provision of care for certain categories of people, such as military veterans and Native Americans. The federal government and many state governments also provide health insurance to employees, as do many municipal governments. In recent years, a growing number of providers have stopped accepting patients insured by Medicaid and even Medicare, citing burdensome administrative requirements and low reimbursement rates. Individuals who are not eligible for Medicare, Medicaid, or SCHIP in the United States must purchase health insurance or healthcare on the private market. Many Americans are provided with subsidized health insurance as a fringe benefit of employment, although the percentage of employers offering health insur-
ance to workers and, especially, workers’ dependents, is shrinking every year due to higher health insurance premiums. Small and family-owned businesses are particularly unlikely to offer health insurance, as these firms are too small to negotiate attractive premiums. Likewise, part-time or freelance workers are usually not offered health insurance plans by their employers. Decreasing coverage by employers has fueled a recent rise in the number of Americans without health insurance in the early 21st century. Individuals can purchase insurance premiums, but these premiums are often prohibitively expensive. In 2004, an estimated 15 percent of the total population, or about 45 million Americans, lacked health insurance. While critics of increased government funding for healthcare often indicate that a government program may reduce choice, it is important to note that most privately insured Americans now belong to an HMO plan, which restricts choice of providers to certain networks if patients want full reimbursement of expenses. These providers are those that have negotiated with the insurance company for a certain price, in exchange for referrals for business. Thus, the market is already restricting choice of provider. health insurance One myth regarding healthcare in the United States is that health insurance is required for access to care. The federal Emergency Medical Treatment and Labor Act (EMTALA) states that hospitals and providers accepting Medicare payments must provide emergency medical care, including providing a medical intake exam, stabilizing an emergency condition, or allowing a pregnant woman to deliver, regardless of ability to pay. This law applies to all individuals regardless of United States citizenship or immigration status, and thus has become a primary means of obtaining medical care for illegal immigrants, who often have no access to either government programs or employersponsored insurance. The costs of providing care for uninsured individuals in emergency rooms is often passed on to other consumers in the form of higher charges and premiums, which often induces employers or other funders to drop coverage, leading to more uninsured patients. Many free clinics also exist, as well as community-based health clinics that charge low-income patients special rates. Still, consistently accessing primary care via free or community-based clinics can be difficult and time consuming.
Another problem related to health insurance affordability is the problem of underinsurance. Many of those with health insurance are only insured against catastrophic losses, and must pay high deductibles, coinsurance, or copayments for pharmaceuticals, primary care physician visits, and procedures that cost below a certain minimum value. These extra charges can be quite financially burdensome, especially for low-income families; an estimated 50 percent of those who file for bankruptcy do so because of an inability to pay medical bills. A majority of these 50 percent had some sort of insurance. Furthermore, the burden of these charges means that many of those with health insurance still go without needed care because they cannot afford to pay the unsubsidized bill. The problems of uninsurance, underinsurance, and lack of access to care have all contributed to health disparities in the United States between racial groups and social classes, with low-income minorities suffering particularly poor health outcomes relative to other segments of the population. While many argue that these disparities are due to innate health behaviors, a distrust of the medical system among minority patients, and population health factors such as obesity rates, nutritional practices, language barriers, and smoking and other substance abuse, lack of access to affordable care certainly seems to play a role in perpetuating these disparities, particularly in terms of alleviating disabilities and chronic conditions such as diabetes and hypertension. In contrast to the United States, most Canadians receive healthcare free at the point of service, although healthcare is still largely provided privately, rather than in state-owned clinics and hospitals as with Great Britain’s National Health Service. Physicians also generally receive a fee per service, rather than acting as government employees. The federal and provincial governments provide almost all of the money for physicians and inpatient services. The largest public program in Canada is also called Medicare, which are all run according to common principles set out in the Canada Health Act, but are administered by different provinces, much as Medicaid is administered by each state in the United States. Patients within the Medicare system are free to choose their own providers, who are then reimbursed. Medicare at the federal level operates largely via block grants to the provinces, in conjunction with funding for
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other social programs; this arrangement can lead to significant differences in the types of care and means of accessing care across provinces. The largest federal program outside of Medicare provides for care for the First Nations people, directly reimbursing providers for their care. As in the United States, veterans and prison inmates are provided for by their own programs. Canada funds the Medicare and other health programs via payroll taxes on employers, as well as user premiums in some provinces. Canada’s healthcare plan does not cover certain services, including dental care for anyone over 14, optometry services (in some areas), or prescription drugs. Many Canadians have supplementary health insurance to cover these items, as do many elderly Americans who do not want to rely on Medicare as the sole means of insurance. Canadians also purchase health insurance on the private market in order to access care more quickly. Canada does prohibit direct purchase of services within Canada, so citizens have a difficult time “opting out” of the system unless they travel to the United States or another country. As in the United States, a right to healthcare does not always result in access to care, or access in a timely fashion, although little rigorous data exist evaluating how harmful wait lists and other access delays are to patients. Wait times for hospital procedures or office appointments can stretch weeks or months, fueled partially by a chronic shortage of physicians. Nonetheless, despite access problems and some limits on services, the Canadian state guarantees a much higher level of medical services free at the point of use than the United States does, and thus comparative health policy analysts and advocates for (and opponents of ) American universal health coverage often use the United States’ and Canada’s healthcare systems to illustrate the relative merits of a market-based health system (albeit one with substantial state involvement) and a governmentsponsored, single-payer health system. Although cross-country comparisons of health outcomes are difficult, proponents of universal healthcare in the United States will usually point out that while the United States spends an estimated 15 percent of its Gross National Product (GNP) on healthcare, while Canada spends only approximately 9.5 percent, population health statistics are often better for Canadians than for Americans, indicating that the United
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States is getting less “value for money” for healthcare expenditures than Canadians are. According to the World Health Organization (WHO) in 2005, Canadians had a higher life expectancy (79.3 years vs. 77.0 years), lower infant mortality rates (5.6/1,000 live births to 6.4/1,000 live births), and lower rates of under-5 child mortality (6/1,000 live births to 8/1,000 live births) than the United States. Many hypotheses have been advanced to explain these differences, especially those that argue either for or against the United States expanding federal and state funding for the health system. One reason why health outcomes in the United States might be worse than in Canada is due to population health reasons. Drugs, violence, war wounds, alcohol abuse, and obesity are all more common in the United States than in Canada (although Canadians are slightly more likely to smoke), all of which place a burden on the health system. The United States has more illegal immigrants, who are more likely to use expensive emergency rooms for primary care in lieu of relatively inexpensive outpatient clinics. Yet, both countries face the problem of caring for aging populations, so demographics alone likely does not explain all of the cost difference between the two countries. One reason proposed as to why the United States spends more on healthcare with poorer results is because there are so many uninsured Americans who lack access to preventive care as well as primary care, diagnosis, and treatment, and thus present in emergency rooms only when they have already progressed to an advanced stage of an illness or surgical problem that is then more difficult and costly to treat. Access to primary care, however, also seems to be somewhat a problem in Canada, albeit not as extensive a problem as in the United States. The 2003 Canadian Community Health Survey indicated that up to 1.2 million Canadians do not have a primary care doctor, either because they could not find one or had not yet looked. Those without a primary doctor, as in the United States, are more likely to visit an emergency room. Wait lists also contribute to delayed care in Canada. Thus, this problem of access to primary care seems to plague both nations, only the problem is more severe in the United States. There are also some expenditure differences in specific areas that may also help drive the differential in spending between the two countries. Because
Canada’s system of payments is more homogenous than the United States’ system of reimbursement from several different private and public sources, Canada also has a lower percentage of total healthcare expenditures going toward administrative costs. Administrators and physicians are also paid more, on average, in the United States, which is one reason why Canada faces a chronic physician shortage, as many are lured south of the border. There is more direct-to-consumer marketing in the United States of health plans and pharmaceuticals, costs that eventually reach payers. Research and development spending on pharmaceuticals and other technologies is also higher in the United States. Some argue that without the profit motivation, innovation in healthcare would falter should the United States move toward more of a state-funded medical system. It is difficult to know using Canada as an example, since the Canadian government might be unable to afford greater technological spending, or it could be choosing to spend less because it also benefits from innovations discovered in and funded by the United States. Finally, the United States’ infamous malpractice litigation suits often increase costs in healthcare, both in terms of malpractice insurance premiums from physicians and also because of “defensive medicine,” whereby physicians order tests and procedures that are probably not necessary but will protect them against a lawsuit, should a negative outcome occur. Particularly cited by opponents of moving away from a market-based system in the United States is the argument that U.S. healthcare costs more because it is of higher quality. The United States leads the world in terms of advanced diagnostic equipment, such as magnetic resonance imaging (MRI) and computed tomography (CT) scanners. Canadians seeking these services have often crossed the border to pay out-of-pocket rather than wait in long lines at home, anecdotes that critics of universal health insurance in the United States cite as proof that the United States’ system is superior. Yet, because Canada funds treatments that are proven most cost-effective, some argue that Canada offers superior treatment because it is more likely to yield results. Numerous comparative studies examining mortality outcomes from cancer show that while Americans are more likely to develop certain types of cancers,
Health Insurance Portability and Accountability Act (HIPAA)
such as breast and prostate cancer, the overall mortality rate in the two countries is about the same, indicating that Canada’s health system might perform better in terms of cancer care. The two approaches to healthcare both have economic consequences. Canada’s publicly funded system requires higher income taxes, which can suppress economic growth. Yet, in the United States, individuals often face “job lock,” whereby they fear changing employment lest they lose affordable healthcare coverage. This “job lock” can suppress labor market flexibility. Furthermore, companies that pay high premiums for employee care are often at a competitive disadvantage in the global economy, because of this relatively high cost of labor. This disadvantage has been particularly prevalent in industries such as the auto industry, which faces highly unionized workforces and heavy “legacy” costs—health benefits promised to previous generations of workers who are now retired. Both countries face the challenge of increasing medical costs due to higher utilization rates of expensive technology, as well as aging populations. Recently, in the United States, some states and municipalities have started universal access programs of their own, tired of waiting for federal reform. The City of San Francisco and the State of Oregon have both recently moved toward covering all uninsured citizens, as has the State of Massachusetts. Proposals range from forcing companies to cover more of their part-time workers to expanding Medicaid and SCHIP to all uninsured. Yet, these reformers face strong opposition to universal health insurance from the hospital and health insurance industry, and in many cases from physicians and health workers themselves, who fear lower incomes and reduced autonomy. Reform proposals in Canada generally focus on increasing the amount of funding for reimbursements to providers, rather than dismantling the system of public health insurance altogether. Canadians seem to take pride in their universal health system, in part because, by being based on fairness and equity, it is distinct from the United States’ market-based system. SEE ALSO: Medicaid; Medicare. Bibliography. Steffie Woolhandler Terry Campbell, and
David U. Himmelstein, “Costs of Health Care Administra-
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tion in the United States and Canada,” New England Journal of Medicine, (August 21, 2003); U.E. Reinhardt, et. al., “U.S. Health Care Spending In An International Context,” Health Affairs, (v.23/3, 2004). Annie Dude University of Chicago
Health Insurance Portability and Accountability Act (HIPAA) Background The Health Insurance Portability and Accountability Act (HIPAA), enacted by the United States Congress in 1996 (Public Law 104-191), is the most significant federal legislation affecting the U.S. healthcare industry since the creation of Medicare and Medicaid in 1965. Over time, the greater utilization of and wider access to personal health information (PHI) in conjunction with insufficient confidentiality protection procedures amplified the potential for unauthorized use and disclosure of individual’s PHI. These trends placed substantial pressure on traditional confidentiality protections and consequently lead to the development of HIPAA legislation. HIPAA was designed to improve the portability and continuity of health insurance coverage; combat waste, fraud and abuse in healthcare; simplify the administration of health insurance; protect the privacy and security of patients’ medical information; and standardize electronic healthcare transactions. HIPAA’s impacts penetrate into all facets of the U.S. healthcare system, most notably on the practices of medical care and clinical research. Components The Healthcare Access, Portability, and Renewability provisions (Title I) regulate the availability and scope of health insurance plans in order to protect the stability of coverage for employees (and their families). The Title also prohibits health plans from creating eligibility rules or assessing premiums based on an individual’s health status, medical history, genetic information, or disability and restricts the limitations
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on benefits health plans can impose based on an individual’s preexisting conditions. The Administrative Simplification provisions (Title II) augment the efficiency and effectiveness of the healthcare system by regulating the exchange of electronic healthcare data. The U.S. Department of Health and Human Services, charged with the task of implementing Title II, instituted five regulations applicable to covered entities (health plans, clearinghouses, and providers) that transmit PHI data. The Standards for Privacy of Individually Identifiable Health Information (Privacy Rule) establishes, for the first time, comprehensive protections for the use and the disclosure of PHI. The Privacy Rule guarantees that health data are properly insulated while simultaneously allowing the exchange of health information necessary for ensuring quality healthcare and protecting the public’s health. It also assures the confidentiality and documentation of any PHI disclosure and mandates notification to individuals regarding any use of their PHI. The provisions are comprehensive and designed to strike a balance between permitting critical uses of information and securing individuals’ privacy. The Transactions and Code Set Rules institute uniform standards for electronic healthcare transactions involving the transfer of PHI and establish consistent code sets and identifiers for electronic data interchange. The Security Rule establishes standardized security requirements for administrative, technical, and physical procedures to ensure confidentiality during the use and dissemination of PHI. The Unique Identifiers Rule institutes consistent standards for electronic transactions by requiring employers and healthcare providers to obtain and use a unique identifier code for all electronic transactions. Last, the Enforcement Rule outlines offenses, monetary penalties, investigation procedures, and hearings for violations. Covered entities that knowingly and improperly disclose identifiable PHI are subject to civil penalties (up to $25,000 annually) and criminal penalties (up to $250,000 and 10 years imprisonment). Implications The complex legalities and potential penalties associated with HIPAA as well as the increase in paperwork and the cost of implementation have necessitated significant changes in the way healthcare providers
and researchers operate. HIPAA restrictions limit, if not eliminate, retrospective chart-based research and researchers’ ability to prospectively recruit research subjects. HIPAA regulations require that covered entities obtain patients’ signed authorization to use or disclose PHI for research purposes. Such research modifications have also significantly increased the cost of performing clinical research. SEE ALSO: Department of Health and Human Services
(DHHS); Institute of Medicine (IOM); Institutional Review Board (IRB); Insurance. Bibliography. B. C. Fuchs, et al., The Health Insurance
Portability and Accountability Act (HIPAA) of 1996: Guidance on Frequently Asked Questions (CRS, 1998); D. Shalowitz and D. Wendler, “Informed Consent for Research and Authorization under the Health Insurance Portability and Accountability Act Privacy Rule: An Integrated Approach,” Annals of Internal Medicine (v.144/9, 2006); G. M. Stevens, A Brief Summary of the HIPAA Medical Privacy Rule (CRS, 2003); U.S. Department of Health and Human Services, Summary of the HIPAA Privacy Rule (Office for Civil Rights, 2003); J. F. Wilson, “Health Insurance Portability and Accountability Act Privacy Rule Causes Ongoing Concerns among Clinicians and Researchers,” Annals of Internal Medicine (v.145/4, 2006). Rebekah M. Zincavage Duane R. Neff Brandeis University
Health Maintenance Organization (HMO) A health management organization is type of medical service in which members prepay a monthly or annual fee for their healthcare needs, including hospitalization. The term was coined by a health policy analyst, Dr. Paul Ellwood, in the early 1970s. At the time, Ellwood and some of his like-minded colleagues regarded Medicare as the advent of a disturbing trend toward socialized medicine. Because of this, he intended to introduce the “health maintenance organization” (HMO) as a better alternative to a socialized system. Ellwood’s goal was to initiate a new direction
in healthcare which would not only provide quality service to the public, but would also contain escalating healthcare costs by preventing disease and also maintain good health in the population. Most HMOs involve physicians engaged in group practice. Because costs to patients are fixed in advance, preventive medicine is stressed to avoid costly hospitalization. One criticism of HMOs is that patients can use only doctors and specialists who are associated with the organization. Many people who have had a long-standing relationship with a family doctor or specialist have balked at what they see as a limitation of choice. “Open-ended” HMOs offer members the option of seeing a doctor who is not part of the HMO, but the patient must pay additional costs. Proponents of HMOs say that they make healthcare available to more people and that their emphasis on prevention results in earlier diagnosis and increased healthcare savings. Numerous complaints (and lawsuits) have arisen, however, over HMOs’ refusals to approve various treatments, and over the concern that the organizations skimp on care in order to realize profits. An HMO enters into contractual arrangements with healthcare providers (e.g., physicians, hospitals, and other healthcare professionals) who together form a “provider network.” In simple terms, a contracted provider is one who provides services to health plan members at discounted rates in exchange for receiving health plan referrals. Unlike traditional indemnity insurance, healthcare provided by an HMO generally follows a set of care guidelines provided through the HMO’s network of providers. Under this model, providers contract with an HMO to receive more patients and in return usually agree to provide services at a discount. This arrangement allows the HMO to charge a lower monthly premium, which is an advantage over indemnity insurance, provided that its members are willing to abide by the additional restrictions.Members are required to see only providers within this network to have their healthcare paid for by the HMO. If the member receives care from a provider who isn’t in the network, the HMO won’t pay for care unless it was pre-authorized by the HMO or deemed an emergency. Members select a primary care physician (PCP), often called a “gatekeeper,” who provides, arranges, coordinates, and authorizes all aspects of the member’s healthcare. PCPs are usually family doctors, internal medicine doctors, general
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practitioners, pediatricians, and obstetricians/gynecologists. In a typical HMO, most medical needs must first go through the PCP, who authorizes referrals to specialists or other doctors if deemed necessary. Emergency medical care does not require prior authorization from a PCP, and many plans allow women to select an obstetrician/gynecoogist (OB/ GYN) in addition to a PCP, whom they may see without a referral. Members can only see a specialist (e.g., cardiologist, dermatologist, rheumatologist) if this is authorized by the PCP. If the member sees a specialist without a referral, the HMO won’t pay for the care. HMOs are the most restrictive type of health plan because they give members the least choice in selecting a healthcare provider. However, HMOs typically provide members with a greater range of health benefits for the lowest out-of-pocket expenses, such as either no or a very low copayment (the amount of money a member is required to pay the provider in addition to what the HMO pays. It often must be paid prior to services being rendered. HMOs also manage care through utilization review. The amount of utilization is usually expressed as a number of visits or services or a dollar amount per member per month. Utilization review is intended to identify providers providing an unusually high amount of services, in which case some services may not be medically necessary, or an unusually low amount of services, in which case patients may not be receiving appropriate care and are in danger of worsening a condition. HMOs often provide preventive care for a lower copayment or for free, in order to keep members from developing a preventable condition that would require a great deal of medical services. When HMOs were coming into existence, indemnity plans often did not cover preventive services, such as immunizations, well-baby checkups, mammograms, or physicals. It is this inclusion of services intended to maintain a member’s health that gave the HMO its name. Some services, such as outpatient mental healthcare, are often provided on a limited basis, and more costly forms of care, diagnosis, or treatment may not be covered. Experimental treatments and elective services that are not medically necessary (such as elective plastic surgery) are almost never covered. Other methods for managing care are case management, in which patients with catastrophic cases are
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identified, or disease management, in which patients with certain chronic diseases like diabetes, asthma, or some forms of cancer are identified. In either case, the HMO takes a greater level of involvement in the patient’s care, assigning a case manager to the patient or a group of patients to ensure that no two providers provide overlapping care, and to ensure that the patient is receiving appropriate treatment, so that the condition does not get worse beyond what can be helped. HMOs often shift some financial risk to providers through a system called capitation, where certain providers (usually PCPs) receive a fixed payment per member per month and in return provide certain services for free. Under this arrangement, the provider does not have the incentive to provide unnecessary care, as he will not receive any additional payment for the care. Some plans offer a bonus to providers whose care meets a predetermined level of quality. Some critics regard HMOs as monopolies that distort the market for healthcare. They argue that HMOs were supposed to be a stopgap solution, and perhaps even set up for ultimate failure so the public would demand that the federal government would take over with a national healthcare system. See Also: Health Insurance Portability and Accountabil-
ity Act (HIPAA); Medicaid.
American Heart Association, www. americanheart.org (cited October 2006); Ellyn Spragins, “Beware Your HMO,” Newsweek (October 23, 1995); John E. Kralewski, Roger Feldman, Bryan Dowd, and Janet Shapiro, “Strategies Employed by HMOs to Achieve Hospital Discounts: A Case Study of Seven HMOs” Health Care Management Review (v.16/1, 1991); Huey L. Mays, Jerald Katzoff, and Marc L. Rivo, “Managed Health Care: Implications for the Physician Workforce and Medical Education,” Journal of American Medical Association (v.274/9, 1995); William MacMillan Rodney, “Health Care Reform: Does Primary Care Mean, ‘Whoever Gets There First?’” American Family Physician, (v.50/2, 1994); Linda S. Widra and Myron D. Fottler, “Determinants of HMO Success: The Case of Complete Health,” Health Care Manage Review, (v.17/2,1992). Bibliography.
Ben Wynne, Ph.D Gainesville State College
Health Resource and Services Administration (HRSA) Created through the 1982 merger of the Health Resources Administration and the Health Services Administration, the Health Resource and Services Administration (HRSA) is an agency of the United States Department of Health and Human Services. It is the primary federal agency for improving access to healthcare services for those who are uninsured, isolated, or medically vulnerable. The HRSA provides national leadership, program resources, and services needed to improve access to culturally competent, quality health care. Focusing on those with the most need, the agency has as its goals the overall improvement of the nation’s access to healthcare, the improvement of healthcare outcomes, the improvement of the quality of healthcare, the elimination of health disparities, the improvement of public healthcare systems, the improvement of responses to emergency situations, and overall excellence in management practices. The HRSA has six operating components. The Bureau of Health Professions (BHPr) provides national leadership in coordinating, evaluating, and supporting the development and utilization of the Nation’s health personnel. The Bureau of Primary Health Care (BPHC) provides national leadership in assessing the nation’s healthcare needs of underserved populations and in assisting communities to provide primary healthcare services to the underserved in moving toward eliminating health disparities. The Bureau also administers the Black Lung Clinics program, the Native Hawaiian Health Care Program, the Healthy Communities Access Program, the Radiation Exposure Screening and Education Program, and the National Hansen’s Disease Program. Healthcare Systems Bureau (HSB) provides national leadership and direction in several key functional areas, including the procurement, allocation and transplantation of human organs and blood stem cell; the facilitation of the development of state, territorial, and municipal preparedness programs to enhance the capacity of the nation’s hospitals and other healthcare entities to respond to mass casualty incidents caused by terrorism and other public health emergencies; the provision of programmatic,
Hearing Problems in Children
financial and architectural/engineering support for healthcare facilities construction/renovation programs; the reduction in numbers of uninsured persons through the State Planning Grants Program; and the management and operation of the national programs for childhood vaccine and smallpox vaccine injury compensation. The HIV/AIDS Bureau (HAB) provides leadership in the delivery of high-quality clinical care and supporting services for uninsured and underinsured individuals living with and families affected by HIV/ AIDS. It includes the Office for Advancement of Telehealth, the HRSA-wide developer of telehealth, including the use of electronic information and telecommunications technologies for all types of healthrelated activities. It also includes HRSA’s Center for Quality which strengthens and improves the quality of health care, especially related to agency programs and service populations. The Maternal and Child Health Bureau (MCHB) provides national leadership, in partnership with key stakeholders, to improve the physical and mental health, safety and well-being of the maternal and child health (MCH) population. The MCH population includes all of the Nation’s women, infants, children, adolescents, and their families (including fathers), and children with special healthcare needs. The Bureau also manages the HRSA Office of Women’s Health. The Office of Rural Health Policy (ORHP) serves as a focal point within the department and as a principle source of advice to the administrator and secretary for coordinating efforts to strengthen and improve the delivery of health services to populations in the nation’s rural areas and border areas.
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Hearing Problems in Children Most children are able to hear the minute they are born. However, two or three out of every 1,000 children in the United States are born without the ability to hear. Hearing problems such as hearing loss can be a significant life-changing event to a newborn baby or child and to his or her family. Among the wide range of hearing disabilities, there are two different types of permanent hearing loss and a condition of temporary hearing impairment that can be seen commonly among children. Treatment options are available to resolve reversible hearing problems and understanding if your child is experiencing hearing difficulties can help the treatment process be more effective. Temporary hearing loss in children can be caused by a variety of problems. These include a collection of wax in the ear canal, a foreign object stuck in the ear, excess mucus that accompanies a cold and sits in the Eustachian tube, or an ear infection such as otitis media (infection of the middle ear). Children can also develop hearing problems from specific diseases such as meningitis. Although there are many causes of temporary hearing loss, permanent hearing impairment is also possible. Permanent deafness can fall into one of two categories. The first type is a hearing condition where the auditory nerve (cranial nerve 8) in the inner ear is damaged. This damage cannot be reversed. The other
See Also: Department of Health and Human Services
(DHHS).
Bibliography. Health Resources and Services Adminis-
tration, www.hrsa.gov (cited September 2006); Health Resources and Administration HIV/AIDS Bureau, hab.hrsa. gov/history.htm (cited September 2006); United States Department of Health and Human Services, www.hhs.gov (cited September 2006). Ben Wynne, Ph.D Gainesville State College
Two or three out of every 1,000 children in the United States are born without the ability to hear.
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type of hearing loss is where external sound waves are unable to reach the inner ear. This can be caused by numerous problems such as earwax buildup, fluid collection, or even a punctured eardrum that cannot be fixed. Hearing problems that go without the proper treatment and care progressively get worse until they disappear completely. Treatment options include hearing aids, special training, specific medications, and certain surgical procedures. ����������� Because of the problems that can arise without early treatment of hearing impairment, it is imperative that you take note of your child’s daily activities and look for signs that might indicate some difficulty in hearing. Some of these signs include when a child fails to respond when called, complains of hearing ringing in his or her ears, speaks loudly at inappropriate times, watches television at an abnormally high volume, pronounces words incorrectly, comes across as inattentive, and is highly prone to daydreaming. If any of these indications are noted, it is crucial that action be taken immediately. The mechanism of the process of hearing and the reasoning behind hearing impairment is an important concept necessary to learn to develop a strong understanding of this disability. Unfortunately, sound does not travel properly through fluid or cerumen (earwax), and because of this, children who develop ear infections may experience difficulties in hearing. Normal speech tends to sound soft spoken like a whisper, so these children are inclined to feel the need to speak much louder. This hearing impairment only exists so long as the infection is present. It has no connection with any permanent hearing deficits. Nevertheless, if the child were to develop constant recurrent middle ear infections, it is likely that this child will experience a delay in his or her speech development only because he or she is unable to hear properly. Hearing problems that arise at birth can be difficult to diagnose. They might not be too obvious until the baby reaches the age of 12 to 18 months, the time when children start saying their first words. Prior to this age, children with hearing loss have a tendency to respond to their surroundings by utilizing their senses such as their eyes and sense of touch. This method of reacting to their environment can actually cover any underlying hearing difficulty the child might have. SEE ALSO: Acoustic Neuroma; Child Development; Deaf-
ness; Ear Disorders.
Bibliography. Better Health, “Ear Problems in Children,”
www.betterhealth.vic.gov (cited May 2007); Better Health, “Hearing Problems in Children,” www.betterhealth.vic.gov (cited May 2007); MedlinePlus, “Hearing Disorders and Deafness,” www.nlm.nih.gov/medlineplus (cited May 2007); World Health Organization, “World Health Organization Fact Sheet on Deafness and Hearing Impairment,” http://www.who.int/ mediacentre/factsheets/fs300/en/ (cited May 2007). Akta Sehgal University of Missouri, Kansas City School of Medicine
Heart Attack Cardiovascular disease (comprised mainly of heart disease and stroke) represents the leading cause of mortality and morbidity globally. In the United States, heart attacks make up about half of the prevalence of all coronary heart disease. Definition and Medical Diagnosis A heart attack, known in medical terms as an acute myocardial infarction, refers to the death of heart tissue following the rupture of atherosclerotic plaque in the wall of a coronary artery that causes a blood clot to block the flow of blood and supply of oxygen through the artery downstream to that area. The rupture of the atherosclerotic plaque is often triggered within a few hours by factors such as physical exertion (particularly for people not normally active), emotional stress, anger, and excitement. A heart attack can be life threatening, and typically requires hospitalization. Common symptoms of a heart attack include chest pain, sweating, and shortness of breath, although heart attacks can also occur without any symptoms (so-called “silent” heart attacks). A diagnosis of heart attack is made according to criteria of a positive history, electrocardiogram, and heart enzymes measured in the blood, as set out by the World Health Organization. “Probable” and “definite” diagnoses of a heart attack require that two and all three of these criteria are met, respectively. Risk Factors Established risk factors for coronary artery atherosclerosis (and thus heart attacks) include age, male gender,
cigarette smoking, elevated low-density lipoprotein (LDL) cholesterol, low high-density lipoprotein (HDL) cholesterol, hypertension, diabetes, physical inactivity, obesity, and low socioeconomic status (as measured by income and education). Risk factors for which there is less consensus among scientists include novel markers of systemic inflammation such as C-reactive protein, elevated homocysteine and lipoprotein(a) levels, psychological factors such as depression and hostility, and physical and social environmental factors such as living in a poor neighborhood. The average age at which a first heart attack occurs is 66 years in men and 70 years in women. In general, higher rates of a first heart attack occur among blacks than among those of other races/ethnicities. The average rates for a first heart attack per 1,000 population in nonblack women during the 1990s were estimated at 6.8, 14.2, and 33.2 for ages 65 to 74, 75 to 84, and 85 and older, respectively. Among black women, the average rates per 1,000 for these same age groups were higher at 8.6, 17.6, and 24.8, respectively. These discrepancies are in keeping with the higher prevalence of heart disease risk factors also found among blacks. Based on a study spanning 52 countries, nine modifiable risk factors (including smoking, abnormal lipid levels, hypertension, and diabetes) account for more than 90 percent of the risk of a first heart attack. This suggests a tremendous potential to reduce heart attack risk and the burden of heart disease through these risk factors. The associations were consistent between men and women, between racial/ethnic groups, and across geographic regions, such that these findings should be applicable worldwide. In recent years, research studies have increasingly explored associations between the socioeconomic environments of neighborhoods in which one lives and the risk of a heart attack. In a four-year followup study of the entire Swedish population aged 40 to 64 years, researchers looked at the relationship between the level of neighborhood socioeconomic deprivation and the risk of being admitted to hospital with a nonfatal heart attack, controlling for one’s age and income. Both women and men living in the poorest versus richest neighborhoods had 1.9 and 1.4 times higher odds of a nonfatal heart attack, respectively.
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Treatments and Medical Consequences After a diagnosis of heart attack is made, medical treatments while in hospital include clot-dissolving medications (thrombolysis), angioplasty, and coronary bypass surgery. If not already on them, patients are started on medications including aspirin, beta-blockers, and statins, and are recommended to make changes to lifestyle risk factors, to lower their risk of future cardiovascular events. Based on data from the Framingham Heart Study, those who survive a heart attack are estimated to have 1.5 to 15 times higher risks of illness and death than those in the general population. Within six years of a heart attack, 18 percent of men and 35 percent are estimated to experience another heart attack, 8 percent of men and 11 percent of women to suffer a stroke, and 7 percent of men and 6 percent of women to have a sudden death. Studies are also ongoing as to the extent to which psychosocial factors, including social support, may help to improve long-term survival among heart attack patients. A heart attack is a lifethreatening condition that contributes to substantial morbidity and mortality worldwide. A variety of risk factors for heart attacks have been established, while other risk factors have emerged and continue to be investigated. Many of the established risk factors are modifiable, such that intervening on these risk factors could have a major impact on the overall burden of heart attacks and cardiovascular disease. A number of treatments have also been developed to limit medical consequences among heart attack patients. SEE ALSO: Cholesterol; Diabetes; Heart Diseases (Gen-
eral); Heart Diseases—Prevention; High Blood Pressure.
Bibliography. P.C. Strike and A. Steptoe, “Behavioral and
Emotional Triggers of Acute Coronary Syndromes: A Systematic Review and Critique,” Psychosomatic Medicine (v.67, 2005); K. Sundquist, M. Malmstrom, and S.E. Johannson, “Neighborhood Deprivation and Incidence of Coronary Heart Disease: A Multilevel Study of 2.6 Million Women and Men in Sweden,” Journal of Epidemiology and Community Health (v.58, 2004); T. Thom, et al., “Heart Disease and Stroke Statistics—2006 Update: A Report from the American Heart Association Statistics Committee and Stroke Statistics Subcommittee,” Circulation (v.113, 2006). Daniel Kim, M.D., M.P.H., M.Sc. Harvard School of Public Health
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Heart Bypass Surgery Heart bypass surgery, also known as coronary artery bypass graft surgery (CABG), is the most commonly performed surgical procedure performed on the heart to bypass the obstructed artery (the coronary artery) of the heart and improve blood flow to the heart. The coronary arteries supply oxygen and nutrients to the cardiac muscles; due to the small size of the arteries, they are often prone to accumulation of fats and cholesterol which can lead to plaque formation and the development of atherosclerosis. If these arteries are blocked there is also a risk of developing ischemic heart disease or coronary artery disease leading to the development of angina. Factors increasing plaque accumulation include high blood pressure, increased cholesterol levels, smoking and the presence of diabetes. The increase in age (greater than 55 years for women and 45 years for men) also increases the risk as does a positive family history for early heart disease. To determine the presence of coronary artery disease, a stress test accompanied by electrocardiogram monitoring of the heart and cardiac catheterisation is performed. The latter is performed by insertion of a catheter through the artery in the groin or arm to the heart, with injection of contrast medium into the arteries. CABGs are generally performed to relieve the chest pain and reduce the risk of death from coronary artery disease. A CABG generally takes four to six hours to complete. There are many techniques of performing a CABG; a detour is created to bypass the obstructed artery. Various arteries and veins may be used as grafts, these conduits include the saphenous vein, the internal thoracic artery (internal mammary artery) and the radial artery. Before the surgery the surgeon will use a coronary angiogram to identify the blockages. The surgical procedure begins with an incision of the middle of the chest followed by a median sternotomy (cutting of sternum). Through this incision the surgeon is able to view the heart and the aorta. To achieve the cardiopulmonary bypass tubes are inserted into the right atrium of the heart which will collect venous blood from the body to the membrane oxygenator in the bypass pump (heartlung machine) thus enabling circulation of oxugenated blood to other parts of the body. The aorta is cross claped to allow bypasses to be connected to
the aorta. The heart is stopped using a mixture of chemicals called cardioplegia. Standard CABG surgery may be associated with concerns over neurological and inflammatory complications related to the bypass and thus many patients receive the off-pump CABG (OPCABG). This technique is used to perform the bypass without the use of the bypass pump. The advantage of this type of surgery is that it may be perfomed whilst the heart is still beating, thus reducing the risk of loss of memory. OPCABG has been reported to be superior in terms of length of stay in hospital following surgery and incidence of stroke; however it associated with a higher rate of mediastinal infection than CABG surgery. A technique known as minimally invasive direct coronary artery bypass (MIDCAB) is also used where the normal action of incision of the chest during the other techniques is avoided. Heart bypasses differ in the numbers of coronary arteries bypassed in the procedure. There may be single bypass (one coronoary artery bypassed), double (two), triple (three), quadruple (four), and quintiple (five). For the coronary arteries to be bypassed, it must be ensured that the arteries are not too small, not heavily calcified, and not located within the heart muscle (intramycocardial). The recovery period after CABG (the first four to eight weeks after the surgery) is associated with higher risks of complications and hospital readmission. CABGs are associated with several risks; they are associated with significant postoperative cardiovascular morbidity and mortality in high-risk patients. Possible risks in receiving a CABG are myocardial infarctions which occur in five to 10 percent of patients. Stroke occurs in one to two percent, primarily in elderly patient. Depression is common after surgery, but is generally improved with the use of cognitive behavioral therapy. Research suggests that risks of CABG are worse in women than men. Overall mortality related to CABG is three to four percent. Mortality may be higher in women, primarily due to their advanced age at the time of CABG surgery and smaller coronary arteries as women are generally smaller than men. Mortality and complications increase with factors such as age (older than 70 years), kidney failure and presence of other diseases such as diabetes mellitus. Approximately 25 to 30 percent of patients undergoing CABG have diabetes mellitus, these patients have increased risk due to respiratory, renal and cerebral
Heart Diseases (General)
complications, and wound infections. Diabetes mellitus represents an independent risk factor for late graft failure and mortality from cardiac causes. CABGs are however performed on these patients as it results in better quality of life in the diabetic patient with severe coronary artery disease, as compared to medical treatment and the use of other surgical procedures such as percutaneous coronary angioplasty. The long-term results after CABG surgery include possible blockage of vein grafts after surgery due to blood clotting. After a successful CABG, a patient’s anginal chest pain generally resolves; however they may experience chest discomfort due to the incision of the chest prior to the bypass. In general, the success rate of CABG is approximately 90 percent; many of these patients experience significant improvements after the surgery. SEE ALSO: Heart Attack; Heart Diseases (General). bibliography. A. Jalal, et al., “Coronary Artery Bypass
Grafting on Beating Heart. Does it Provide Superior Myocardial Preservation than Conventional Technique?” Saudi Medical Journal (v.28/6, 2001).
Farhana Akter King’s College, London
Heart Diseases (General) Heart disease is the leading cause of death and disability worldwide. Approximately 16.7 million people die from heart disease each year, with coronary heart disease killing more than 7 million people. Heart disease can affect any component of the cardiovascular system, which includes the heart muscle, valves, conduction system, coronary arteries and veins, as well as systemic arteries and veins. Coronary artery heart disease, alone, accounts for roughly 2.3 million cases of heart disease annually. There are a variety of types of heart disease that affect a wide range of age groups and ultimately may lead to heart failure. Congenital heart disease, valvular heart disease, cardiomyopathies, and coronary artery disease are examples of heart disease. The severity of these diseases is dependant upon the degree to which they affect the ability
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of the heart to adequately pump blood throughout the body to meet nutritional demands. Coronary artery disease (CAD) is the most common form of heart disease. CAD is the number one killer worldwide for those older than 60 years of age, and is the second leading cause of death, behind HIV/AIDS, for those 15 to 59 years old. Each year, 3.8 million men and 3.4 million women worldwide die from CAD. Currently, in the United States it is estimated that one out of every 2,000 people are affected by CAD. Although genetics play a role in the development of CAD, 80 to 90 percent of people who die of CAD have one or more risk factors influenced by an unhealthy lifestyle. CAD occurs when the arteries that supply blood to the heart muscle become hardened and narrowed. This process is due to a buildup consisting mostly of fat, cholesterol, and calcium that circulate in the blood. The buildup of material is referred to as a plaque and leads to a condition known as atherosclerosis. As the plaque grows in size, the amount of blood passing through the vessels decreases and heart muscle does not receive adequate oxygen needed to survive. The development of atherosclerosis is a process that develops over time, often beginning in childhood and gradually increasing with age. CAD varies in severity and its presentation can range from asymptomatic to chest pain associated with exertion (angina), heart attack, and sudden cardiac death. Acute coronary syndrome refers to the symptoms associated with acute myocardial ischemia due to CAD. Of all people who die within the first month of experiencing CAD symptoms, approximately two-thirds of these people die before reaching the hospital. This highlights the importance of prevention and early recognition of CAD symptoms. Risk factors for CAD in developed countries are divided into two groups: modifiable and nonmodifiable. Modifiable risk factors include high blood pressure, high cholesterol, smoking, diabetes, excess weight, and sedentary lifestyle. Nonmodifiable risk factors include family history, increased age, and male gender. Approximately 75 percent of heart disease can be attributed to conventional risk factors. Some less recognized risk factors include low socioeconomic status, mental illness, stress, alcohol, excess blood homocysteine, and inflammation. Those in developing countries face an even greater burden of risk factors in the fact that they also have to contend with low birth weight and folate
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deficiency due to malnutrition and communicable diseases, as well as the other risk factors. As the name implies, modifiable risk factors are those factors that an individual can change in his or her daily lifestyle. High blood pressure, also known as hypertension, is a very common factor leading to CAD. It is estimated that by the time that a person reaches 60 years old, he or she has a greater than 60 percent chance that they are living with high blood pressure. Of that number, 31 percent of those people are unaware of the condition and are not experiencing any signs or symptoms. High cholesterol is most frequently a result of the food we eat; however genetics play an important role in determining cholesterol levels. Cholesterol can be made by the body or obtained from the foods high in cholesterol (i.e., meat, fish, eggs). Foods that do not contain cholesterol but are high in saturated fats and trans fats also lead to elevated levels of cholesterol production and increase risk of heart disease. Cholesterol is divided into four different types. Increased levels of total cholesterol, triglycerides, and low-density lipoprotein (LDL) are responsible for increased risk, and an estimated one-third of all cardiovascular disease worldwide is attributed to high cholesterol. High-density lipoprotein (HDL) is the final type of cholesterol and has been shown to have a protective effect on the arteries of the body; therefore, decreased HDL levels leads to increased risk of heart disease. Therefore control of cholesterol is an important consideration in the attempt to decrease the risk of developing CAD. lifestyle heart risks Concerning smoking, cigarette smokers are 60 percent more likely to develop CAD due to toxins damaging the inner layer of the blood vessel walls. Even though there is an increased incidence of CAD in smokers, approximately 20 percent of adult men and 22 percent of adult women continue to smoke cigarettes. Healthcare costs directly related to smoking result in a global net loss of $200 billion per year, with one-third of those losses occurring in developing countries. Diabetes is a disease characterized by elevated blood sugar levels, and is primarily caused by decreased insulin production (type 1) or decreased responsiveness of tissues to insulin (type 2). Insulin is a hormone produced by the pancreas, and functions to transport sugars from the bloodstream to various
tissues for nutrition and storage. Another risk factor is excess weight, which leads to increased workload of the heart and is a key factor in the development of high blood pressure. Body mass index (BMI) is a method to calculate the degree of excess weight, and takes into account the weight and height of the individual. Healthy people have a BMI in the range of 18.4 to 24.9, while an index of 25 to 29.9 is considered overweight and an index of more than 30 is considered obese. Studies have shown that a decrease in weight by 11 to 22 pounds can reduce the risk of developing high blood pressure by over 25 percent. It has been proven that physical activity improves the ability of the heart and lungs to pump blood more effectively. Subjects with a sedentary lifestyle have a twofold increased risk of having a fatal heart attack compared to active people of the same age with equal risk factors. Exercise on a regular basis also helps to decrease all of the other aforementioned modifiable risk factors. Prevention strategies, such as lifestyle modifications, are the first step to decreasing the risk of heart disease. Recommendations to a healthier lifestyle include 30 minutes of moderate physical activity four or more days a week, smoking cessation, and diets rich in fruits, vegetables, and potassium that avoid saturated fats and high-calorie meals. Decreasing body weight and avoiding stresses of daily life can reduce the demand on the heart. CAD typically occurs in middle-aged people, but risk factors are determined by lifestyle behaviors in childhood and early adulthood. Worldwide, 18 million children under 5 years are overweight, and 14 percent of 13- to 15-year-olds smoke cigarettes. This highlights the importance of healthy lifestyle choices early on to significantly decrease risk of heart disease in the future. Congenital heart disease refers to defects of the heart that are present at birth, and most commonly affect the chambers of the heart, heart valves, and the arteries and veins in close proximity of the heart. Examples of the most common defects include atrial septal defect (ASD), ventricular septal defect (VSD), and patent ductus arteriosus (PDA), with VSD being the most common congenital defect. In the United States, in approximately six to eight of every 1,000 live births, the baby will be born with a congenital heart defect. Congenital diseases of the heart may be a consequence of genetic factors or adverse exposures during pregnancy such as maternal alcohol use, cer-
tain medications (e.g., warfarin, angiotensin converting enzymes) used by the expectant mother, maternal malnutrition, and maternal infections such as rubella. Although many of these defects will be detected at birth, many patients present for the first time in adulthood. It is estimated that more than 750,000 adults in the United States are currently living with congenital heart disease. This number is expected to increase by approximately 9,000 adults per year. congenital factors Another category of heart disease involves the valves within the heart. These valves help direct the flow of blood by opening and closing with contraction and relaxation of the heart. The two types of valvular abnormalities involve difficultly opening valves (stenosis) and the inability to tightly close valves (regurgitation). These abnormalities can lead to decreased ability of the heart to efficiently pump blood and can eventually lead to heart failure. Within the heart, there are four valves: the aortic, mitral, tricuspid, and the pulmonic valves. The aortic valve, located in the left ventricle and leads to the aorta, and the mitral valve, located between the left atrium and left ventricle and regulates blood flow within the heart and are key in any discussion concerning valvular abnormalities. There are two types of aortic stenosis that are not congenital in nature; these include aortic stenosis due to calcium deposits and rheumatic aortic stenosis due to old rheumatic fever. Calcific aortic stenosis has a high correlation with coronary artery disease. The most common etiology for congenital aortic stenosis is bicuspid aortic valve. Stenosis decreases the size of the outlet from the heart, thus the heart muscle must work harder to pump out the same amount of blood as a normal heart. This increased workload causes the heart muscle to thicken, and eventually the muscle will not be able to maintain the workload and it will ultimately result in heart failure. Regurgitation is the development of backflow through valves that are unable to tightly close. This additional blood that leaks back causes the heart muscle to stretch and the chambers of the heart to become dilated, leading to decreased efficiency and potentially heart failure. Regurgitation most commonly occurs in three of the four valves of the heart: the aortic, mitral, and tricuspid valves. The cause of this regurgitation can be related to aging, infection, genetics (e.g., Marfan’s
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syndrome), and autoimmune diseases (e.g., systemic lupus erythematosus). Concerning mitral stenosis, the majority of cases are secondary to rheumatic heart disease, and predominantly affect women. Mitral valve stenosis and regurgitation affect blood flow between the left atrium and left ventricle, and are attributed to the same factors as aortic stenosis and regurgitation. Mitral valve prolapse, most commonly diagnosed valvular abnormality, is a condition where the mitral valve bulges into the left atrium. Prolapse is a direct result of insufficient or lax fibrous bands, called chordae tendenae, which anchor the valve to the left ventricle. The tricuspid and pulmonic valves are also susceptible to stenosis and regurgitation; however, this occurs with less frequency than the aortic and mitral valves. Therapies for valvular dysfunctions vary from medical management to treat the symptoms or surgical intervention to replace or repair the valve itself. illness and heart disease Rheumatic fever can develop following a bacterial infection in the blood, and results in an inflammatory illness that can lead to disability or death. Rheumatic fever and rheumatic heart disease affects 15.6 million people globally, including 2.4 million children. It is the most common cardiac disease in children and young adults. There are an estimated 500,000 new cases each year, 300,000 of which are from Africa. Rheumatic fever is due to bacterial invasion by Streptococcus pyogenes and is typically preceded by a sore throat and fever that is left untreated. The aortic and mitral valves are the most commonly affected; however, the tricuspid and pulmonic valves are not immune to damage. Ultimately, acute rheumatic fever can lead to scarring of the heart valves. Theses valves that are affected by rheumatic heart disease are more susceptible to colonization by other bacteria, and can progress to infective endocarditis. Cardiomyopathies are diseases of the heart muscle that alter the ability of the heart to pump adequate blood throughout the body. An estimated 50,000 Americans are affected by cardiomyopathies, and they are the leading cause of heart failure leading to transplantation. The three main categories of cardiomyopathy include genetic, mixed, and acquired cardiomyopathies. The most important causes of genetic abnormalities include hypertrophic cardiomyopathy. Hypertrophic cardiomyopathy involves the thickening of the heart muscle,
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Heart Diseases—Prevention
which causes outflow obstruction and inadequate filling of the heart chambers with blood. This condition is inherited in half the cases, and affects one out of 500 live births in the United States. Hypertrophic cardiomyopathy is the second leading cause of heart disease, and the most common cause of sudden death in young, otherwise healthy athletes. Examples of mixed cardiomyopathies include dilated and restrictive cardiomyopathy. In dilated cardiomyopathy, the heart muscle becomes stretched and loses its ability to contract, and can be due to a virus, excessive alcohol intake, or due to unknown causes. It is also the third most common cause of heart failure and the most frequent cause of heart transplantation. Restrictive cardiomyopathy hinders the ability of the muscle to contract and relax due to scarring or abnormal deposits in the muscle, but in most cases the cause remains unknown. Chest radiation, chemotherapy, and connective tissue diseases can lead to scarring and fibrosis, while amyloidosis and hemochromatosis are responsible for abnormal deposits. The final classification, acquired cardiomyopathy, can be due to inflammation (myocarditis), stress, or chronically elevated heart rates. It is important to recognize the extent and impact of heart disease among the worldwide population. The incidence continues to rise in developing countries as the average life expectancy increases. Genetics plays a minor role in the development of heart disease, leaving unhealthy lifestyle decisions to be the greatest predictor of the development of heart disease. There are many decisions one can make to decrease the risk of heart disease such as smoking cessation, diets low in cholesterol and high in fruits and vegetables, and regular exercise. Proper education for children concerning healthy lifestyles should be taught at a young age to reduce the incidence of heart disease in adulthood. There have been great strides made in diagnostic technology and the treatment of heart disease; however, the fundamental message concerning heart disease is that the greatest reduction in death and disability can be seen with prevention and not cure. SEE ALSO: Heart Attack; Heart Bypass Surgery; Heart Dis-
ease—Prevention; Heart Transplantation..
Bibliography. Bernard J. Gersh, The Ultimate Guide
to Heart Health: Mayo Clinic Heart Book (William Morrow, 2000); “Heart Disease,” www.cdc.gov (cited Septem-
ber 2006); “Heart Disease,” www.who.org (cited October 2006); Dennis L. Kasper, Harrison’s Principles of Internal Medicine (McGraw-Hill, 2005); Barry J. Maron, et al., “Contemporary Definitions and Classification of the Cardiomyopathies: An American Heart Association Scientific Statement from the Council on Clinical Cardiology, Heart Failure and Transplantation Committee; Quality of Care and Outcomes Research and Functional Genomics and Translational Biology Interdisciplinary Working Groups; and Council on Epidemiology and Prevention,” Circulation (v.113, 2006). Hamid Ghanbari Independent Scholar
Heart Diseases—Prevention According to the World Health Organization (WHO), an estimated 17 million people die of cardiovascular diseases (CVD) every year worldwide. The two leading types of CVD are coronary heart disease and stroke, both of which the death rates are declining in developed regions such as North America and western European countries, but rising steadily in still developing countries. This decline has been attributed to a combination between advances in diagnosis and treatment, and most importantly on aggressive public health policies on preventive measures that minimize the role modifiable risk factors in CVD progression. In the worldwide INTERHEART study, which comprised of 52 countries and 30,000 study subjects, nine potential modifiable risk factors were found to be contributing to over 90 percentof the population risk for a first myocardial infarction (MI). These factors consisted on physical activity, diet and consumption of fruits and vegetables, alcohol consumption, psychosocial factors, smoking, hypertension, diabetes, dyslipidemia, and abdominal obesity. Physical Activity It should come as no surprise that physical activity is directly related to lowering the risk of CVD. The mechanism for lowering cardiovascular risk is due to improved oxygen transport and reduced myocardial oxygen demand due to lowered systolic blood
pressure and decreased resting heart rate. The effect of physical activity appears to be graded, that is, the risk of coronary disease decreases in a stepwise fashion as the intensity of the activity is increased. General consensus defines adequate physical activity as lasting 20 minutes or more of brisk walking, for about five times a week without pauses. Diet and alcohol It has been shown in multiple studies that a diet high in fruits and vegetables contribute to a lower risk of cardiovascular disease, namely MI and stroke. Also, a high fiber diet can substantially reduce the risk of cardiovascular complications. Dietary fat is also an important contributor to CVD, and it appears that the type of fat ingested is more important than the total amount of fat. Trans fatty acids are associated with a higher incidence of coronary heart disease, while polyunsaturated fat and monounsaturated fat decreases this incidence. Fish consumption, due to its high amount of omega-3 fatty acids, also has been shown in randomized trials to lower the incidence of cardiovascular disease. Recent news has focused on the role of alcohol in lowering CVD risk. Moderate consumption of alcohol, that is one drink per day for women and two drinks per day for men have shown to decrease cardiovascular mortality. As should be expected, excessive intake of alcohol substantially increases the risk of stroke. Psychosocial Factors A reduction in the psychosocial stressors in life contributed to a reduction in cardiovascular risk. These factors included depression, stress at work or home, financial stress, and feeling of control. Smoking Multiple studies and meta-analysis have shown the importance of smoking cessation in preventing cardiovascular disease, making smoking the largest preventable cause of death. Smoking not only increases blood pressure and heart rate, but at the biological level, it causes endothelial injury, platelet activation and coronary plaque destabilization. Significant benefits are seen after smoking cessation at one year, decreasing the risk of MI and death from cardiovascular disease by one-half; while cessation at three years equals the cardiovascular risk from that of a nonsmoker.
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Hypertension Aggressive blood pressure control is essential in reducing cardiovascular risk. The Seventh Joint National Committee (JNC 7) provides important guidelines for therapy based on concomitant diseases as well as the degree of hypertension. Systolic blood pressure control is just as important as diastolic blood pressure. Hypertension is defined as blood pressure greater than 140/90 in two separate readings taken at more than two office visits. Tighter blood pressure control (< 130/80) is aimed at patients with hypertension and other comorbid diseases such as diabetes, renal insufficiency and heart failure. Firstline agents for initiation of drug therapy should be a thiazide diuretic or a beta-blocker based on the ALLHAT study. Other choices to consider are ACE inhibitors, angiotensin-receptor blockers, and calcium channel blockers, depending on their other comorbidities. Additionally, it is important to stress the importance of lifestyle modifications which are essentially very similar if not identical to the cardiovascular modifiable risk factors. Diabetes The role of tight glycemic control cannot be overemphasized. Diabetes is now considered a coronary artery disease (CAD) equivalent, which should come as no surprise since the presence of diabetes allows for more severe CAD as well as more diffuse coronary disease. A subanalysis of the United Kingdom Prostective Diabetes Study found that a 1 percent reduction in HbA1C was associated with an 18 percent reduction in MI as well as 15 percent reduction in stroke. In addition, tight glycemic control has clear and significant benefits on microvascular complications such as neuropathy, nephropathy, and retinopathy. Dyslipidemia Appropriate management of dyslipidemia leads to the slowing of the progression of atherosclerosis. Statins have become the mainstay of lipid lowering therapy but its mechanism of action appears to be more pleomorphic than previously thought. Additional benefits of statins include improved endothelial function, decreased platelet thrombus formation, and decreased vascular inflammation by decreasing CRP levels, a marker of active inflammation. Current guidelines for the treatment of
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dyslipidemia are based on the Adult Treatment Panel III (ATP III) and it involves a nine-step process. See Also: Heart Attack; Heart Bypass Surgery; Heart Dis-
eases (General); Heart Valve Diseases.
Bibliography. Bernard J. Gersh, The Ultimate Guide to
Heart Health: Mayo Clinic Heart Book (William Morrow, 2000); “Heart Disease,” www.cdc.gov (cited September 2006); “Heart Disease,” www.who.org (cited October 2006); Dennis L. Kasper, Harrison’s Principles of Internal Medicine (McGraw-Hill, 2005). Michael Yeung Independent Scholar
Heart Transplantation Heart transplantation is a surgical procedure to implant a healthy heart into a patient with heart failure. Heart transplantation is usually the last option on a list of treatments for heart diseases. The primary diagnoses of patients receiving heart transplants are coronary artery disease, cardiomyopathy, and congenital diseases. The first heart transplant was performed by Professor Christiaan Barnard at Groote Schuur Hospital in South Africa in December 1967. A major barrier to transplantation is the process of rejection in which the recipient’s immune system recognizes the graft being foreign and attacks it. The antigens responsible for this reaction are the HLA system. The HLA genes are highly polymorphic and any two individuals (except identical twins) will express different HLA proteins. The three organ rejection reactions are hyperacute, acute, and chronic. Hyperacute rejection occurs within minutes or hours of transplantation and can be recognized by the surgeon just after the graft vasculature is anastomosed to the recipient’s. This process occurs when preformed antidonor antibodies are present in the circulation of the recipient. An acute rejection occurs within days of transplantation in an untreated recipient or may occur months or years later when the immunosuppression has ended. Acute rejection is a combined process in which cellular and humoral parts of the immune system contribute. Chronic re-
jection presents in patients over a period of four to six months. It is usually irreversible and is the single largest cause of organ transplant rejection. Mechanisms for increasing graft survival are to match more of the HLA genes between the recipient and the donor. Also, patients are given immunosuppressive drugs to prevent attack of the transplanted organ by the transplant recipient’s immune system. Common drugs are cyclosporine, azathioprine, steroids, rapamycin, and mycophenolate mofetil. A common side effect of immunosuppressive treatment is for the recipient to be more susceptible to opportunistic infections most likely by fungal or viral organisms. Also, these patients are at a higher risk for cancers that are caused by viruses. Current research to overcome this obstacle of immunosuppression is looking at inducing donor-specific tolerance in host T lymphocyte cells. The United Network for Organ Sharing (UNOS) is a private, nonprofit organization that matches available organ donors with waiting transplant recipients through the national Organ Procurement and Transplantation Network (OPTN). Organ procurement is dependent on recipient time on waiting list, severity of disease, ABO blood type, and body size. Contraindications specific to heart transplants are if the patient has an active infection, pulmonary hypertension, untreatable liver or kidney disease, chronic lung disease, mental illnesses, disease of the blood vessels in the brain, and continued alcohol or drug abuse. In general, the two forms of heart procedures are orthotopic or heterotopic. In an orthotopic procedure, the patient’s heart is removed leaving portions of the left and right atrium, pulmonary vein, and aorta. The new heart is then modeled to fit the recipient’s chest and the different chambers and vessels are anastomosed together. In a heterotopic procedure, the patient’s own heart is not removed before implanting the donor heart. The two hearts are connected together to form a “double heart.” This way, the patient’s own heart may recover from the decreased workload and be able to function normally in the future. This procedure is also done if the donor heart is large enough to sustain the patient’s body or if the donor heart is too weak. In both procedures, the donor heart is stimulated to maintain a regular beat through medications or a pacemaker. After the surgery, the patient usually
Heart Valve Diseases
remains in the intensive care unit for 24 to 72 hours. Also for the next few months following the surgery, the patient revisits the transplant center for weekly physical examinations. According to 2000 data from the Registry of the International Society for Heart and Lung Transplantation (ISHLT), 81 percent of transplant recipients survive one year. During the first year, infection and acute rejection are the leading causes of death. A constant 4 percent decrease occurs yearly after the first year as the incidence of coronary allograft vascular disease increases. Pediatric patients less than 1 year of age are least likely to reject the donor heart, but 30 percent of older pediatric patients succumb to transplant rejection. SEE ALSO: Heart Attack; Heart Bypass Surgery; Heart Dis-
eases; Organ Donation; Organ Transplantation.
Bibliography. Vinay Kumar, et al., Pathologic Basis
of Disease (Elsevier Saunders, 2005); Mary C. Mancini, “Heart Transplantation,” www.emedicine.com (cited January 2006); Medline Plus, “Heart Transplant,” www.nlm. nih.gov (cited January 2006); United Network for Organ Sharing, “How the Transplant System Works: Matching Organ Donors and Recipients,” www.unos.org (cited January 2006). Pavan Bhatraju University of Louisville
Heart Valve Diseases Heart valve disease refers to a group of conditions affecting the mobility and closure of the heart’s four valves. Anatomically, the heart is divided into four chambers. Deoxygenated blood returns from the periphery of our body through the inferior and superior vena cava into the right atrium. The tricuspid valve serves as the gateway from the right atrium into the right ventricle. The pulmonic valve, in turn, regulates the flux of the blood from the right ventricle into the pulmonary arteries. Blood then enters the pulmonary circulation for oxygenation, and return to the left atrium. From the left atrium, blood transverses the mitral valve to reach the left ventricle, and ultimately
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is pumped to the aorta leading to our systemic circulation through the aortic valve. Heart valve diseases arise as a result of congenital abnormalities or acquired conditions such as infections or degenerative processes, which in turn change the hemodynamic blood patterns that flow through the heart valves. These abnormalities often lead to narrowing or stenosis, or it can also lead to leakage, which is also called regurgitation. Valvular murmurs can often be picked up through auscultation, and the degree of severity is formally quantified by the use of transthoracic echocardiogram. Below is a review of the most common valvular conditions. Aortic Valve Stenosis Aortic stenosis occurs from a narrowing of the aortic valve, often caused by either progressive calcification of the valve or rheumatic heart disease. It is important to note that rheumatic aortic valve is often accompanied by mitral valve disease as well. There are also congenital conditions such as unicuspid and most commonly bicuspid aortic valve which changes the properties of the valve and predisposes it to early narrowing. The natural history of aortic stenosis is characterized by asymptomatic progression until the valve area is narrowed enough to elicit the classical symptoms of angina, syncope, and exertional dyspnea. Severe aortic stenosis is suggested by an aortic jet velocity greater than 4 m/s, a mean transvalvular gradient greater than 50 mmHg, and an aortic valve area of less than 1 cm². Severe aortic stenosis warrants surgical intervention with aortic valve replacement. In Heyde’s syndrome, a subgroup of patients with aortic stenosis are also found to have concomitant gastrointestinal bleeding. This is thought to be due to defective von Willebrand factors from disruptive passage across the narrow valve in the background of arteriovenous malformations. Aortic Valve Insufficiency Aortic valve insufficiency may occur from an abnormality of the aortic valve or a dilatation of the aortic root, causing diastolic regurgitant flow from the aorta back into the left ventricle. This backflow of blood causes increased left ventricular pressure, dilatation, and hypertrophy. Causes for this dilatation include bicuspid aortic valve, aortic aneurysms, and Marfan’s
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syndrome. Of importance, patients with aortic insufficiency who develop severe left ventricular dilatation are at increased risk of sudden cardiac death (SCD), and serial annual echocardiograms are warranted in order to monitor the progression of disease. Medical therapy with afterload reducers such as nifedipine or angiotensin-converting enzyme (ACE) inhibitors can delay the progression of aortic insufficiency. Surgical replacement of the aortic valve should be considered when the left ventricular end-systolic diameter reaches 55 mm or if the ejection fraction is less than 60 percent. Mitral Valve Stenosis Mitral stenosis is often associated with prior history of rheumatic heart disease, with more women affected than men in a 2:1 ratio. Of note, the sequelae of rheumatic fever presents at different age groups depending on the geographic area. For example, in Africa, the sequelae of rheumatic mitral stenosis occurs during their teenage years, as opposed to patients in Asia who often present in their 20s, and patients from the United States and Europe, who become symptomatic during their 50s. The initial presentation of severe mitral stenosis is dyspnea, often during exertion or exercise. Cough and occasionally hemoptysis are also findings consistent with this condition. Some female patients may also present with pulmonary congestion symptoms during their pregnancy due to increase blood flow and volume through a stenotic mitral valve. Severe mitral stenosis is suggested by a mitral valve area <1 cm², a transvalvular diastolic pressure gradient >10 mm Hg, or severe pulmonary hypertension >60 mm Hg. It is also important to note that severe increases in left atrial pressure due to the stenotic valve, predisposes left atrial enlargement, and subsequent development of atrial fibrillation. Management of mitral stenosis in asymptomatic patients involves avoidance of factors that may increase left atrial pressure such as vigorous exercise, fevers, or tachycardia. Anticoagulation is indicated for patients with mitral stenosis and atrial fibrillation due to the higher incidence of thromboembolism. Interventions for severe mitral stenosis include mitral valve repair by percutaneous valvotomy or mitral valve replacement. Percutaneous valvotomy is an appropriate alternative to surgery, but it requires a transesophageal echocardiogram in order to rule out the presence of
a left atrial appendage thrombus and also ensure that mitral regurgitation is less than moderate in severity. Most common complications of valvotomy include severe mitral regurgitation, systemic embolization of thrombus, and pericardial tamponade. Surgical commissurotomy or mitral valve replacement is indicated if percutaneous valvotomy cannot be performed safely. Comparison of percutaneous versus surgical approaches has yielded similar success rates. Mitral Valve Regurgitation Chronic mitral valve regurgitation is mostly caused by myxomatous disease such as Marfan’s or EhlersDanlos, mitral valve prolapse, infective endocarditis, or rheumatic heart disease. Mitral regurgitation should be followed by a cardiologist for serial echocardiograms and clinical evaluation in order to determine the timing of intervention. Mitral valve repair is the procedure of choice when appropriate, and it avoids the complications of open heart surgery as well as chronic anticoagulation. It is important to differentiate acute versus chronic mitral regurgitation because the former can be a medical emergency. Acute mitral regurgitation is often seen with rupture of the chordae tendineae due to endocarditis or myocardial infarction. This leads to severe dyspnea and pulmonary edema, and may require surgical intervention. See Also: Heart Attack; Heart Bypass Surgery; Heart Dis-
eases (General).
Bibliography. Bernard J. Gersh, The Ultimate Guide
to Heart Health: Mayo Clinic Heart Book (William Morrow, 2000); “Heart Disease,” www.cdc.gov (cited September 2006); “Heart Disease,” www.who.org (cited October 2006). Michael Yeung Independent Scholar
Heat Index Heat index is the ambient or environmental temperature as perceived by the human body. The heat index is based on both raw air temperature values and the
Heat Index
relative humidity or moisture that is present in the air. The heat index offers a value that expresses how the climate “feels” on the body in an objective and universal manner. Heat and heat-related injuries across the developing world are a significant cause of occupational injuries and hazards and are a preventable illness. Heat-related injuries affect millions in both mild and severe climates each year. The body is able to release heat by fluctuating the rate and depth of blood circulation in the periphery, by liberating water through the skin and sweat glands, and through respiration. These described compensatory mechanisms are very important for maintaining normal body temperature. More specifically, sweating cools the body with evaporating water off the skin and taking with it some of the heat the body holds. However, if the humidity in the air is high, it cannot easily release this water and therefore, cannot easily release heat. In very humid climates, such as regions along the equator, it is difficult for the body to compensate and to lose heat in an efficient manner. This leads to heat injury and illness. These compensatory mechanisms start acting when the environment is cooler or warmer than normal body temperature (37.0 degrees C or 98.6 degrees F). The ability to maintain body temperature within these limits is described as thermoregulation. Deviation too far from these normal limits can cause unconsciousness and death. A high heat index is indicative of high ambient air temperatures and high humidity. A low heat index are low ambient air temperatures and low relative humidity. A high heat index can also exacerbate other underlying disease such as respiratory illness as asthma and chronic obstructive pulmonary disease (COPD). Measurements have been taken based on subjective descriptions of how hot subjects feel for a given temperature and humidity, allowing an index to be made which corresponds a temperature and humidity combination to a higher temperature in dry air. Calculation for heat index in Celsius takes into account vapor pressure, relative humidity, and temperature: Heat index = T + 5/9 X (e – 10); where e = V X [(6.112 X 10 ^((7.5T / 237.7) + T)] X (R / 100); where V = vapor pressure; R = relative humidity, and T = temperature. A table exists that correlates heat and relative humidity in this heat index for easy observation of dangerous heat conditions.
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The heat index is based on both raw air temperature values and the relative humidity or moisture that is present in the air.
For example, if it is 27 degrees C ambient temperature with relative humidity of 95 percent it will “feel” like 31.3 degrees C. Maintaining normal body temperature requires much of the energy we get from food consumption. If the body does not have enough fat stores, calorie consumption, or clean drinkable water, thermoregulation becomes compromised and heat illness and injury may occur. Clean potable water sources and consequent consumption is a major threat to much of the developing world where the heat index remains high for much of the year and heat illness inflicts many. SEE ALSO: Drinking Water; Oral Rehydration Therapy;
Sun Exposure.
bibliography. Christopher C. Burt, Extreme Weather: A
Guide and Record Book (Norton, 2004); M. Khogali, “HeatRelated Illness” Middle East Journal of Anesthesiology (v.12/6, 1995); D. Tek, J.S. Olshaker, “Heat Illness.” Emergency Medicine Clinics of North America (v.10/2, 1992); Jack Williams, The Weather Book, (Vintage Books, 1997). John Michael Quinn V, MPH University of Illinois at Chicago
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Hematologist
Hematologist Disorders of the blood and their related body organs are vast and complex disease processes. Doctors who treat them require special medical training to ensure people with these diseases are able to receive proper treatment. However, not all blood diseases need to be treated by a hematologist. The term hematology is defined as the study of one particular branch of medicine concerned with blood, the blood-forming organs, and blood diseases. Hematology includes the study of etiology, diagnosis, treatment, prognosis, and prevention of blood diseases. A doctor who specializes in this diagnosing and treating is called a hematologist. Work for hematologists may range from the management of a hematology laboratory, work at a microscope viewing blood and bone marrow slides, to interpretation of various other blood test results. By viewing blood under the microscope, a doctor is able to visually see if the cells are of normal shape, size, and number. Variation in any of these from what is considered “normal” may indicate a blood disease is present. Sometimes, parasites can even be seen in blood cells and lead to the diagnosis of malaria, for example. Besides looking at blood, some other tests involve reacting blood with specific chemicals to see how the blood behaves. For example to check if a person has a bleeding disorder, a chemical is added to the blood which causes it to react and form a blood clot. The amount of time necessary for blood to clot is recorded. Normal times have been established through experiments, thus by comparing the test person’s time to the normal test value, a hematologist can determine if a bleeding disorder is present. This is just one example of hundreds of blood tests performed. Examples of common diseases treated by hematologists are anemia, disorders of blood clotting, and leukemia. Anemia is simply a decrease in the number of red blood cells, also known as the oxygen carying cells of the human body. Without these cells, we would not be able to get oxygen to the rest of our body. Causes of anemia are great, but most commonly, it is simply a decreased amount of iron in the body which is necessary for red blood cell function. Anemia can also be caused by destruction of blood cells by parasites like those that cause malaria (plasmodium falciparum, for example). One of the many other causes of anemia
worthy of mention is because of vitamin defficiency or failure of proper resorption of vitamins required in the steps of making red blood cells. A hematologist must explore all of these possibilities of causes of anemia including, but not mentioned above, leukemia or blood cancer in order to help resolve a patient’s underlying cause of anemia. Hemophilia is a disease that results from lack of certain blood-clotting factors. There are different types based on which factor is missing. A wellknown person with hemophilia in recent past was Ryan White. He may be better known from his fight for civil rights of those with HIV. Ryan White contracted HIV through a blood transfusion as part of his treatment for hemophilia. This is not very common anymore due to screening and a better understanding of the AIDS virus, but in the 1980s, there was a poor understanding of this virus. While hemophilia is a disease characterized by the decreased ability to form a blood clot, several other diseases result from decreased or total lack of clot formation. An example is von Willebrand’s disease, which results from a related but different blood clotting factor. A hematologist must carefully analyze several tests designed to determine the missing or decreased factors to determine the type of bleeding disorder. Only then can the proper treatment and precautions for the patient be determined. Blood cancers or leukemias and lymphomas are also a major part of the work of hematologists. These doctors are called hematologist/oncologists, where oncology means cancer. Many different types of leukemias exist. Examples of leukemias commonly seen are acute lymphoblastic leukemia and chronic lymphoblastic leukemia. Many of the leukemias and lymphomas are derived from white blood cells. White blood cells, like any other cell in the body, start out as immature cells and mature into their final form. As a mature cell, they are mostly responsible for fighting infections in one way or another. Disturbance in the maturation or development causes the formation of cells that do not function properly, which is then called a leukemic or lymphoma cell, depending on the origin of the cell. It is the job of a hematologist to examine these cells under a microscope and analyze cells with special equipment, such as flow cytometry, to determine exactly what type of cell is causing the leukemia or lymphoma. Only after the cell type and origin are determined can
Hematology
the proper treatment be rendered. This is because different chemotherapeutic agents are aimed at treating different types of leukemias. Hematologists are specialists of medicine who work in conjunction with other physicians to treat patients with blood diseases. It is only after a hematologist has determined the underlying cause of the blood disorder that the proper treatment can be determined. The decision to give a blood transusion, hormones, nutritional supplements, bone marrow transfusions, or even chemotherapy depends on the expertise of the hematologist and testing/analysis of blood and related organs. Hematologists serve to diagnose and treat many blood disorders that range from very common and not life threatening like iron deficiency anemia to rare but deadly forms of leukemia. See Also: Anemia; Hematology; Leukemia. Bibliography. Robert Hillman, and Kenneth A. Ault,
Hematology in Clinical Practice (McGraw Hill, 2002); Kumar Vinay, et al., Robbins and Cotran Pathologic Basis of Disease (Elsevier Saunders, 2005). Angela Garner, M.D. University of Missouri–Kansas City
the lymphatic system. Following the success of blood transfusions since the 17th century, hematology has become heavily concerned with ensuring that transfusions are done as safely as possible. This involves ensuring that the blood plasma from the donor is free of infection or disease, and that it has been stored properly and categorized into the correct group. This has become particularly important from the mid-1980s with the problems over HIV-infected blood, and later with blood which may be infected with bovine spongiform encephalopathy (“mad cow disease”) or other related complaints. In addition to mainstream hematology, there are also specialities such as dealing with bleeding disorders including hemophilia, treating hematological malignancies including leukemia and lymphoma, and also treating hemoglobinopathies. There are a number of different classes of hematologic diseases: hemoglobinopathies, anemias, problems involving a decreased number of blood cells, myeloproliferative disorders (with an increased number of cells), hematological malignancies, coagulopathies, and other miscellaneous issues. The study of hemoglobinopathies involves covering areas where there is a congenital abnormality of the hemoglobin molecule or in the rate of hemo-
Hematology Hematology is a branch of physiology and biology that is concerned with the study of human blood, the human organs concerned with blood, and also diseases of the blood. It also involves a study of the etiology, treatment, prognosis, and prevention of blood diseases, with work carried out by medical professionals known as hematologists. The word hema comes from the Greek word for “blood,” with logos from the Greek meaning “study.” As a basic medical science, hematology is concerned with dealing with blood, blood cells, and blood vessels. This involves working with blood tests, blood poisoning, venipunctures, and related issues. It also is concerned with other related aspects of medicine such as dealing with problems concerned with the reticuloendothelial system, including bone marrow, the spleen, liver complaints, and also problems with
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Hematology involves treatment, prognosis, and prevention of diseases by testing blood and blood cells.
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Hematology
globin synthesis. This includes sickle-cell diseases which come from genetic disorders of sickle hemoglobin. Other related diseases include thalassemia, an inherited disease affecting red blood cells; and methemoglobinemia which is characterized by a high level of methemoglobin in the blood. With anemias, there is a wide range of potential diseases ranging from some that result from an iron deficiency in the body—often preventable by taking iron supplements and/or eating more red meat, especially kidney. Megaloblastic anemia comes from a B12 deficiency of a folate deficiency, the latter being a particularly important issue for pregnant women. There are also a large number of diseases involving the destruction of red blood cells, collectively called Hemolytic anemias. A number of these are genetic, but others might be induced by drugs, especially a high dose of penicillin. Some are concerned with the membrane of red blood cells, while others are more concerned with their metabolism or direct physical damage to them. Mention should also be made of aplastic anemia whereby bone marrow does not produce enough cells to replenish blood cells in the body. Varieties of this disorder include Fanconi anemia, named after the Swiss pediatrician Guide Fanconi; Diamond-Blackfan anemia, a congenitcal erythroid aplasia; and the acquired pure red cell aplasia. A number of hematologic diseases also arise from a person having a decreased number of blood cells for a whole range of reasons from myelodysplastic syndrome, myelofibrosis, neutropenia, agranulocytosis, glanzmann’s thrombastehenia, and thrombocytopenia. Myeloproliferative disorders, which involve an increased number of cells, can come from polycythemia vera, whereby there is an increase in the number of cells in general; leukocytosis, which involves an increase in the number of white blood cells; thrombocytosis where there is an increase in the number of platelets and various myeloproliferative disorders. There are also a number of hematological malignancies which involve lymphomas, myelomas, plasmacytoma, and leukemias. The lymphomas include Hodgkin’s disease, the non-Hodgkin’s lymphoma, Burkitt’s lymphoma, anaplastic large cell lymphoma, and splenic marginal zone lymphoma. The first three of these are generally classified as cancers which affect lymphocytes and, occasionally, histiocytes. For myelomas, there is multiple myeloma and also Aldernström
macroglobulinemia. Plasmacytoma occurs where a malignant monoclonal plasma cell tumor can grow in the bone or in soft tissue. For leukemias, there is a range: acute lymphocytic leukemia (ALL), chronic lymphocytic leukemia (CLL), acute myelogenous leukemia (AML), chronic myelogenous leukemia (CML), T-cell prolymphocytic leukemia (T-PLL), chronic neutrophilic leukemia (CNL), hairy cell leukemia (HCL), T-cell large granular lymphocyte leukemia (T-LGL), and aggressive NK-cell leukemia. Disorders of bleeding and coagulation are known as coagulopathies, with the most widely known being those which involve the disorders in clotting proteins such as hemophilia (hemophilia A, hemophilia B, and hemophilia C). In addition there is von Willebrand disease, disseminated intravascular coagulation, protein S deficiency, and antiphosphlipid syndrome. The three main diseases connected with the disorders of platelets are thrombocytopenia, Glanzmann’s thrombasthenia, and Wiskott-Aldricj syndrome. Other disorders of bleeding and coagulation include thrombocytosis, recurrent thrombosis, and disseminated intravascular coagulation. The last category of hematological problems include some disorders such as hemochromatosis, asplenia, hypersplenism, monoclonal gammopathy, and also a number of hematological changes which are secondary to nonhematological disorders such as AIDS, malaris and leishmaniasis. See Also: AIDS; Anemia; Leukemia. Bibliography. Laurent Degos, David C. Linch, and Bob
Löwenberg, eds., Textbook of Malignant Haematology (Taylor & Francis, 2005); William G. Finn and LoAnn C. Peterson, Hematopathology in Oncology (Kluwer Academic Publishers, 2004); A.V. Hoffbrand, J.E. Pettit, and P.A.H. Moss, Essential Haematology (Blackwell Science, 2002); Martin R. Howard and Peter J. Hamilton, Haematology: An Illustrated Colour Text (Churchill Livingstone, 1997); Atul B. Mehta and A. Victor Hoffbrand, Haematology at a Glance (Blackwell, 2005); Reinhold Munker, Erhard Hiller, and Ronald Paquette, Modern Hematology: Biology and Clinical Management (Humana Press, 2000); Chris Pallister, Blood Physiology and Pathophysiology (ButterworthHeinemann, 1994). Justin Corfield Geelong Grammar School, Australia
Hemizygous A cell or organism is hemizygous at a locus (a fixed position on a chromosome, such as the position of a gene) if it possesses only one allele for a given trait. In humans, males are hemizygous for alleles expressed on the sex chromosomes as they have only one of each. Contrast this with females who have two copies of the X chromosome and are thus either homozygous or heterozygous at loci on the sex chromosomes. The classic example of hemizygous inheritance is hemophilia. Classic hemophilia (hemophilia A) is an X-linked, recessive disorder caused by mutations affecting the factor VIII gene, located on the long arm of the X chromosome but nowhere on the Y chromosome. Thus, men with only one mutant allele for the factor VIII gene show a diseased phenotype because the Y chromosome does not have an allele capable of expressing wildtype factor VIII. Women, on the other hand, are not hemizygous at the locus of the factor VIII gene. As only one wildtype allele is necessary to prevent a diseased state, women who are heterozygous at the factor VIII locus will usually not show signs of disease. Only women who are homozygous for the mutant genotype (or are heterozygous with two different, mutant phenotypes) will show signs of disease. The prevalence of hemophilia (and all X-linked recessive diseases) is thus much higher in men than in women. The hemizygous nature of men also has consequences for the inheritance of X-linked disease. In the case of X-linked recessive diseases, a man with the disease state will pass on the mutant allele to all of his daughters and none of his sons (because all sons receive the Y chromosome). The fate of both the sons and daughters of a man with the mutant allele thus depends on the status of the mother. On the other hand, consider a man with the wildtype allele at the locus in question. While the status of his sons still depends on the status of the mother, the man can be confident that virtually none of his daughters will be affected because they are guaranteed to inherit a wildtype allele from him. Not all hemizygous traits are X-linked recessive. Although much less common, certain traits are X-linked dominant and there also some Y-linked disease states. The general considerations for inheritance of X-linked dominant traits are similar to those for X-linked recessive traits. However, because
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dominant inheritance only requires one mutant allele to be present for disease to manifest itself, all of the daughters of an affected father will be affected, whereas affected mothers stand only a 50 percent chance of passing on an affected allele, regardless of the sex of the offspring. It should also be noted that many X-linked dominant disorders are much more prevalent among women than men, even more so than simple probability would suggest. The most common explanation for this is that hemizygosity for a dominant mutant allele is lethal during gestation. This does not seem to be the case with Y-linked alleles, the inheritance of which is always dominant. Males who carry mutations on Y-linked genes may suffer from infertility but seldom suffer a serious disease state that is incompatible with life. SEE ALSO: Allele; Heterozygote; Homozygote. Bibliography. S, Callejas, et al., “Hemizygous Subtelo-
meres of an African Trypanosome Chromosome May Account for over 75% of Chromosome Length,” Genome Research (v.16/9, 2006); R. L. Nussbaum, et al., Thompson & Thompson: Genetics in Medicine, 6th ed., revised reprint (Saunders, 2004). Bimal P. Chaudhari Boston University
Hemochromatosis Hemochromatosis is a disorder that interferes with iron metabolism, which results in the excessive accumulation of iron in the body. This abnormal buildup of iron is toxic to the body and can cause damage to the organs. Hereditary hemochromatosis is one of the most common genetic disorders in the United States. It is estimated that one out of 200 to 300 individuals are affected. Hemochromatosis is more common in Caucasians of European descent. Causes There are two main causes of hemochromatosis: primary (hereditary) or secondary. Primary hemochromatosis is inherited as a homozygous-recessive genetic disorder. An individual who inherits the defective
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Hemorrhagic Fever
gene from both parents may develop hemochromatosis. Not all individuals who inherit both defective genes will develop manifestations of hemochromatosis. The carrier state, individual with one copy of the defective gene, is estimated to be one out of every nine individuals. The gene affected is called HFE, which is located on chromosome 6. The HFE gene codes for a molecule that regulates the intestinal absorption of dietary iron. The body closely regulates and balances the amount of iron absorbed in the intestines with the amount of iron lost daily. When two copies of the defective HFE gene are inherited, the result is abnormal regulation of intestinal absorption of dietary iron. This leads to excess accumulation of iron in the body. Secondary hemochromatosis is usually due to an underlying disease or condition; it can also be due to blood transfusions. Hemolytic anemias such as thalassemia or sideroblastic anemia are the most common cause of secondary hemochromatosis. Blood transfusions to manage aplastic anemia and sickle cell disease can also lead to iron overload. Clinical Symptoms The symptoms of hemochromatosis usually appear between ages 30 and 50 and are more frequent in males. Males present symptoms at an earlier age than females because of the physiologic iron loss during menstruation and pregnancy. Principal clinical manifestations include abdominal pain, fatigue, darkening of the skin pigmentation, joint pain, testicular atrophy, and loss of sexual desire. Hemochromatosis causes a buildup of iron in the body, especially in the liver, heart, and pancreas. Hemochromatosis can lead to liver enlargement, cirrhosis (scarring of the liver causing dysfunction), liver failure, or cancer of the liver (hepatocellular carcinoma). Iron buildup in cardiac tissue can cause irregular heart rate or rhythm (arrhythmia) and lead to heart failure. Hemochromatosis can cause damage to the pancreas and lead to diabetes mellitus. Screening and Treatment Screening for hemochromatosis involves blood tests to evaluate serum iron levels and ferritin levels. Screening family members is important for primary hemochromatosis. Treatment is necessary to remove the excess iron in the body and to prevent organ damage from toxic levels of iron. Patients are treated by phlebotomy (removal of blood).
SEE ALSO: Anemia; Sickle Cell Disease. BIBILOGRAPHY: Centers for Disease Control and Preven-
tion, “Hemochromatosis,” www.cdc.gov (cited April 25, 2007); “Hemochromatosis,” ADAM Medical Encyclopedia, www.nlm.nih.gov/medlineplus (cited April 25, 2007); V. Kumar, A. K. Abbas, and N. Fausto, Robbins and Coltran Pathologic Basis of Disease, 7th ed. (Saunders, 2005); National Institutes of Health, National Heart, Lung, and Blood Institute, “Hemochromatosis,” www.nhlbi.nih.gov (cited April 2007). Angela J. Garner, MD Melissa Meiners University of Missouri-Kansas City
Hemorrhagic Fever Hemorrhagic fevers (HFs) are diseases characterized by raised body temperature (fever) and rapid blood loss (hemorrhage), which may be either internal or external. They are often referred to as viral hemorrhagic fevers (VHFs) because most are caused by a virus from one of four families: Filoviridae, Arenaviridae, Bunyaviridae, or Flaviviridae. Well-known HFs include Ebola HF, Marpurg HF, Lassa fever, and Rift Valley fever. VHFs are zoonotic and reside in an animal reservoir host or arthropod. Because VHFs are dependent on their animal or insect hosts, outbreaks are generally restricted to areas where the hosts live; this is why many VHFs include a geographic designation in their name. This risk of VHFs, therefore, varies by location: Carriers of some diseases exist in very limited geographic areas, and the risk of contracting those VHF is also limited to those areas. However, other carriers (such as the common rat) exist throughout the world, and thus some VHFs themselves are widely distributed. In addition, VHFs may be spread through transportation of infected animals (Marpurg virus was introduced to Germany and Yugoslavia by infected lab monkeys, for instance) and some, including Ebola, Marpurg, Lassa, and Crimean-Congo Fevers, can also be transmitted from an infected human to another human, or through contact with the blood or other body fluids of an infected person.
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Signs and symptoms common to VHFs include fever, fatigue, dizziness, muscle aches, and weakness and exhaustion. There may be signs of bleeding under the skin or from body orifices, and severe cases may show shock, coma, or seizures. Some VHFs cause only mild illness, while others can be life threatening. Renal failure is associated with some VHFs, and Ebola HF is believed to be fatal in 50 to 90 percent of clinically ill cases, for instance. There is no cure for most VHFs, and no treatment other than supportive care; exceptions include Ribavarin, which has been used to treat Lassa fever, and convalescent-phase plasma, which has been used to treat Argentine HF. SEE ALSO: Dengue; Fever; Sudan; Tropical Medicine. Bibliography. Centers for Disease Control and Preven-
tion, “Viral Hemorrhagic Fevers Fact Sheet,” www.cdc.gov (cited March 2007); World Health Organization, “Infection Control for Viral Haemorrhagic Fevers in the African Health Care Setting,” www.who.int (cited March 2007). Sarah Boslaugh BJC HealthCare
Hemorrhoids A hemorrhoid, also known collectively as emerods or piles, was first so described during the 16th century and the word is derived from the Greek for “the discharging of blood.” It is a swelling and inflammation of veins which can occur in the rectum or anal channel. Essentially, it can be formed by a distension of the vein network under the mucous membrane around the anal channel, or under the skin around the nearby external area. As such, it is a form of varicose vein which can develop from an infection or leads from an increase in the intraabdominal pressure which can occur when lifting very heavy objects, the channel suffering extra strain, or during pregnancy. At its worst, it may result from complications connected with chronic liver disease or the presence of tumors. The presence of hemorrhoids is actually extremely common with some surveys showing that as many as 50 percent of all Americans have had hemorrhoids at some stage during their life before they reach the age
Each year, about 500,000 people in the United States seek medical treatment for hemorrhoids.
of 50. Each year, about 500,000 people in the United States seek medical treatment for this condition, with about 15 percent of these—generally the ones with the worst cases—needing some kind of surgery. It can, therefore, be shown the vast majority of the people who suffer do not seek treatment either because it does not pose much of a medical problem or the condition quickly reverses. There has been a range of research into the causes of hemorrhoids, with a definite genetic link, and some families are often more predisposed to this condition. This can come from a weakness in the vessel wall which means that a condition which results in the higher risk of having hemorrhoids for some people may well be inherited. Additional factors come from obesity and also the increasing sedentary lifestyle, meaning that hemorrhoids are a greater factor in developed countries than in the third world. The British novelist Anthony Burgess, who suffered from hemorrhoids over many years, called the condition “Writer’s Evil,” presumably on the basis that one of the causes comes from the long periods of sedentary activity undertaken by most writers. Another person who also suffered from hemorrhoids was Emperor Napoleon I who, according to his physician, had a bad attack during the Battle of Waterloo in 1815, which made it
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Hepatitis
difficult for him to ride a horse during the battle, and even took him away from the battlefield, costing him the battle, his throne, and his empire. Some of the obvious causes come from postponing of bowel movement, constipation, chronic diarrhea, sustained low-fiber diets, poor bathroom habits, and also pregnancy. It has been suggested that people using the modern lavatory increases the risk of suffering from hemorrhoids, with squat toilets engendering a lower predisposition. However, there has only been limited research on this. A more obvious cause comes from dietary reasons. People who do not drink enough fluid or use too many diuretics (which includes consumption of coffee or colas) can result in harder bowel movements and hence harder stools, leading to irritation which can lead to hemorrhoids. As a result, a diet with increased fiber or hydration, the use of nonirritating laxatives, and baths can be used for treating some types of mild hemorrhoids, with more serious cases requiring medical examination. The most extreme cases are treated by hemorrhoidectomy which involves surgery to excise and remove the hemorrhoid. SEE ALSO: Gastroenterologist; Gastroenterology. Bibliography. Barbara Becker, Relief from Chronic Hem-
orrhoids (Dell, 1992); Steven Peikin, Gastrointestinal Health (HarperCollins, 1999); Sidney E. Wanderman and Betty Rothbart, Hemorrhoids (Consumer Reports Books, 1991). Justin Corfield Geelong Grammar School, Australia
Hepatitis The liver is an abdominal organ that is responsible for an array of vital functions. Hepatitis is a general term used to refer to inflammation of the liver, which can be acute or chronic with a wide variety of causes. Understanding the severity of hepatitis requires an appreciation for the normal synthetic and metabolic functions of the liver. The liver synthesizes proteins, carbohydrates, and fats. The major site for production of proteins for blood clotting is the liver. In addition, maintenance of sugar balance requires liver function. Liver
cells create glucose from pyruvate and lactate in the blood, and can use blood sugars to generate amino acids, fatty acids, or can store excess glucose in the form of glycogen. The liver also regulates production of fatty acids and cholesterol, and produces bile that is important in the metabolism of fats. Last, detoxification of a large number of drugs is accomplished by liver cells, as is the removal of ammonia from the blood. Acute viral hepatitis is a general term used to describe the liver inflammation caused by at least five different, unrelated viruses. The five known hepatitis viruses are hepatitis A, B, C, D (or delta), and E. Hepatitis A and E are spread through a fecal-oral route secondary to poor sanitary conditions. They are highly contagious and can occur in outbreaks but do not have long-term health consequences. Hepatitis B, C, and D are spread via infected blood and sexual contact. While hepatitis B, C, and D do not cause outbreaks, they can lead to chronic hepatitis, which causes cirrhosis and liver cancer (hepatocellular carcinoma). Symptoms of acute hepatitis are varied. There are prodromal symptoms that often precede acute hepatitis, such as a skin rash, painful swollen joints, and fever. Acute hepatitis produces symptoms such as anorexia and nausea. One of the most noticeable signs of hepatitis is jaundice, or yellowing of the skin. The normal liver eliminates a compound caused bilirubin, but hepatic dysfunction leads to a backup of bilirubin into the circulation, and accumulation of this yellow compound in the skin, conjunctiva and mucous membranes. In the cases of hepatitis A and C, these symptoms resolve; however, with hepatitis B, C, and D, there is often progression to chronic liver disease. Chronic hepatitis can be caused by viral illness and also by medications, alcohol, metabolic abnormalities, and autoimmune disorders. Medications that may potentially cause drug-induced liver disease include isoniazid, nonsteroidal antiinflammatory medications, methyldopa, nitrofurantoin, and many others. Indications of chronic hepatitis are vague, and include fatigue, sleep disorders, pain under the right rib cage, and enlarge liver and spleen, redness (erythema) of the palms and spider angiomata, or dilated blood vessels visible on the skin. Chronic hepatitis can eventually lead to cirrhosis of the liver, or a state of scarring
Hepatitis C
and fibrosis. Patients are often fatigued and susceptible to infection, and may lose weight and become malnourished due to malabsorption. Poor absorption of vitamin A and D lead to vision impairment and osteopenia (thinning of bones), respectively. In addition, liver cirrhosis can lead to gynecomastia (swelling of breast tissue) and atrophic testicles. If cirrhosis progresses to advanced cirrhosis or chronic liver failure, individuals may develop portal hypertension. This occurs when the liver becomes too fibrotic and scarred to adequately filter and transport blood, causing a backup of blood from the portal venous system into the systemic venous system. This can cause fluid retention and edema (swelling), acites (fluid retention in the abdomen), and a backup of blood into veins around the umbilicus, rectum, and lower esophagus. If the backup of blood becomes severe, patients can experience severe bleeding, exacerbated by the lack of clotting factors secondary to cirrhosis. Because portal hypertension prevents sufficient detoxification of ammonia and other metabolites, patients can experience encephalopathy leading to confusion and coma. The backup of blood into the spleen can cause splenomegaly, or spleen enlargement and splenic dysfunction, anemia (decreased red blood cells), leukopenia (decreased white blood cells), and thrombocytopenia (decreased platelets). Prevention of hepatitis is of utmost importance given the significant morbidity and mortality associated with acute and chronic hepatitis. Vaccines exist for both hepatitis A and B. In addition, avoidance of medicines known to cause liver inflammation as well as alcohol can prevent drug- and alcohol-induced hepatitis. Treatment of hepatitis is largely dependent on the cause of liver inflammation, and can range from supportive care in mild cases to liver transplantation when there is severe cirrhosis and liver failure. SEE ALSO: Hepatitis C. Bibliography. Elaine A. Moore, Hepatitis: Causes,
Treatments and Resources (McFarland, 2006); Jing-Hsiung James Ou, ed., Hepatitis Viruses (Kluwer Academic Publishers, 2001). Christine Curry Independent Scholar
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Hepatitis C Hepatitis C is inflammation of the liver caused by a bloodborne pathogen, the hepatitis C virus (HCV). Hepatitis C is only one of many viruses of the hepatitis family that causes viral liver disease; others include hepatitis A, B, D, and E. HCV causes both acute hepatitis, characterized by jaundice, fatigue, abdominal pain, and loss of appetite, as well as longterm liver diseases such as liver cancer and cirrhosis. Symptoms generally appear after an incubation period of 15 to 150 days, although the majority (70 percent) of those infected are asymptomatic. Chronic infection occurs in approximately 55 to 85 percent of infected persons, and about one to five percent of those chronically infected will eventually die from chronic liver diseases. In countries where liver transplants are available, cirrhotic HCV patients often represent the majority of recipients of donated livers. Patients infected with HCV are often also infected with HIV or hepatitis B, both of which can worsen HCV disease prognosis, as can high alcohol consumption. Transmission of HCV is via direct contact with infected blood, and transmission is often a result of contaminated blood transfusions, the use of contaminated syringes, or contaminated circumcision, tattooing, or piercing equipment. Sharing of syringes among intravenous drug injectors in prisons has led to outbreaks. Patients on kidney dialysis, transplant recipients, and hemophiliacs have also been infected in the past. Sexual transmission is possible, although rarer, and transmission rates are enhanced when individuals are coinfected with other sexually transmitted diseases or are sexually assaulted. Healthcare workers face a risk of infection from workplace injuries. The virus can also be transmitted from a mother to a baby during childbirth in approximately 4 percent of cases, although the transmission probability rises if a mother is coinfected with HIV. Hepatitis C is not spread via casual contact, sneezing, coughing, breastfeeding, food, or water, although it can be spread via sharing common items such as razors and toothbrushes if they contain contaminated blood. Globally, approximately 170 million people are infected with hepatitis C, and thus it statistically affects about four to five times as many people as
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those currently infected with HIV. Approximately three to 4 million new infections occur annually. Individuals are often coinfected with HIV or hepatitis B. Areas of the world with the highest prevalence rates include Africa, southeast and eastern Asia, and the eastern Mediterranean region. Countries that have a larger-than-average reservoir of chronically infected HCV patients, such as Italy, Pakistan, Egypt, and Japan, often have a history of widespread injection-based prophylaxis treatments against other infectious diseases, suggesting that sterilization of injection equipment is essential when implementing population-based vaccination and treatment programs. Public awareness of the disease is often not as high as of other infectious diseases, such as HIV, and as patients are often asymptomatic, even those infected are often not aware of their illness until they present with long-term liver complications. Medical awareness of HCV is also lower than for HIV, and many patients at high risk of HCV infection go undetected even by medical personnel. There is no vaccine against HCV, and developing vaccines and treatments has proved challenging because HCV is highly variable and mutates rapidly. Interferon, either alone or in combination with ribavirin, is used to treat HCV infection. The combination treatment proves effective in approximately half of infected persons, although this success rate varies widely depending on which genotype of the virus the patient is infected with. These drugs can also cause serious side effects: Ribavirin can cause severe anemia and interferon treatment can result in depression, seizures, or flu-like symptoms. Treatment is recommended for individuals whose infection does not resolve within two months (approximately 60 percent of all those infected). Women who are pregnant should not be treated with either drug. There is no postexposure prophylaxis for HCV. Preventing new infections is much more economically feasible than providing long-term treatment for chronically infected patients, because treatments such as liver transplants and the interferon/ribavirin regimes are quite costly. Preventative measures often include screening of blood donors, organ donors, and the blood supply; viral inactivation of plasma products; and implementing preventative measures in healthcare settings, including sterilizing injection equipment. As the
majority of new infections in the developing world occur among intravenous drug users, promoting safe injecting behaviors in high-risk populations is particularly important in reducing new infections. Also, in addition to maintaining safe injection practices in medical settings, noninjection-based methods of drug delivery, such as pills or liquids, should be promoted when possible. See Also: Hepatitis. Bibliography. M. Dolan, The Hepatitis C Handbook,
(North Atlantic Books, 1999); H. Worman, The Hepatitis C SourceBook (NTC Publishing, 2002). Annie Dude University of Chicago
Herbal Medicine For as long as humankind has suffered from illnesses, it has looked for substances to alleviate its symptoms. Since the early 20th century, those medicines have tended to be the standardized synthetic drugs found behind any pharmacist’s counter; before that, however, the nature and practice of prescription was different. The medicinal use of herbs dates back thousands of years and is common to all cultures, and in fact, many current prescription medications are derived from botanicals. There is a cultural element to the use of traditional remedies that may confound a nonintegrated approach; treatments are recommended by friends at least as often as by physicians, and users show a remarkable amount of resolve—one study indicated that 72 percent would continue use even after a scientific study with negative results. There is a push toward evidence-based medicine in the United States, and many herbal products are undergoing clinical trials to determine their efficacy with mixed results. Patients may seek out herbal products, feeling they are safer than prescription products, as they are natural. Many examples of adverse events exist in the medical literature, at times due to interactions with prescription medication. Through the education of the public as well as healthcare workers, some of these adverse events may be avoided.
The foreword to the Physician’s Desk Reference on Herbal Medicines (3rd ed.), defines herbal medicine as preparations derived from naturally occurring plants with medicinal or preventive properties. Natural remedies are popular throughout the planet, although their use is often manifested differently depending upon the prevailing healing traditions of the given culture. In America, the use of alternative or complementary avenues of healthcare—often including herbal medicines—is on the rise. The lack of a strong foundation of empirical data regarding their efficacy, and poor communication between conventional healthcare providers and their herb-taking patients produces a strained and potentially dangerous environment, but the potential benefits of this and other complementary and alternative medicine (CAM) modalities have prompted many modern physicians to seek a fruitful integration of botanicals and pharmaceuticals. Many patients will not tell their physician, even if asked about herbal use, as they feel the physician may be scornful, or may not know about herbal products. Many physicians fail to ask patients about the use of these products, possibly leading the patient to believe their use is unimportant. Medical schools traditionally do not educate students about CAM modalities, although this is beginning to change. Worldwide Use of Herbal Medicine Herbs continue to be used medicinally by people around the world. In some developing countries, the use of an herbal remedy is still inextricably tied to rituals of healing with supernatural/spiritual overtones. In others, the preponderant use of herbs is the result of economic factors—some natural remedies require neither a doctor to prescribe nor a pharmacist to prepare them. The traditional healers of China regularly use herbs along with other techniques considered CAM in the Western model of healthcare, such as acupuncture and therapeutic massage. Their use goes back at least 5,000 years and as far back as the Ming Dynasty (1386–1644 a.d.), Li Shizhen catalogued medicinally used botanical products in the still-popular text Compendium of Materia Medica. In India, over 80 percent of the population takes at least one of the 6,000 herbal combinations used in ayurvedic tradition. In the European Union (EU), herbal medicine (or phytotherapy) is often highly integrated into what is
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considered mainstream medical care, and the use is regulated in a similar manner to conventional drugs everywhere except the United Kingdom and the Netherlands. Two-thirds of the general public in Germany uses herbal remedies, which accounts for 50 percent of the $7 billion spent on herbal medicines by the EU in 1996. Accordingly, all German physicians are required to train and be tested over the proper use of herbs before they may be licensed. Roughly 80 percent of those doctors go on to prescribe herbal medicine to their patients. Domestic Use of Herbal Medicine In the United States, the use of natural remedies is on the upswing (nearly one in five people reported having used at least one such product in 2002) after a significant decline following the spread of synthetic pharmaceuticals, which provided larger effects and profits. This resurgence may be attributed to a variety of factors, such as a desire among some people to seek out unconventional and “natural” paths, the inability of conventional medicine to cure chronic conditions (such as arthritis, depression, and memory loss), a loss of faith in the pharmaceutical companies and/or the government, and misleading advertising on the part of some herbal supplement providers. While it is incorrect and unsafe to assume that all natural remedies are inherently beneficial and innocuous, some herbs have been proven to possess qualities that do promote health or treat illness when used properly. Similarly, while many believe that synthetic drug manufacturers strive to marginalize the use of herbal supplements (and therefore are suspicious of government-funded studies that seem to discredit alternative medicine), it is important to note that those supplements are largely deregulated and some suppliers will use this uncertainty to their own advantage (“10 Natural Cures They Don’t Want You to Know About”, etc.). Domestic Regulation of Herbal Medicine The increased public interest in natural healthcare that began in the 1960s prompted Congress to establish the National Institutes of Health Office of Alternative Medicine in 1992, which became the National Center for Complementary and Alternative Medicine (NCCAM) six years later. Thirty years after the Kefauver-Harris
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Drug Amendment of 1962 relegated herbal remedies to the laxly monitored classification of food supplements, the Food and Drug Administration (FDA) tried to develop a more stringent set of regulations but was opposed, resulting in the 1994 passage of the Dietary Supplement Health and Education Act (DSHEA) which failed to require supplement manufacturers to prove that a product was either safe or efficacious prior to release. Due to the FDA’s lack of premarket involvement, supplements must state on the label “This statement has not been evaluated by the FDA. This product is not intended to diagnose, treat, cure, or prevent any disease” although the labels may still claim that the herbs “improve memory” or “support digestive health”. National surveys show that 81 percent of Americans believe a supplement should not be sold without proven safety, but 70 percent believe the FDA currently tests and regulates all herbal products on the market. As recently as November 9, 2004, the FDA announced major initiatives to improve the transparency and standardization of dietary supplements (as herbal remedies must be called under DSHEA), but all Good Manufacturing Practices (GMPs) proposed thus far are purely voluntary on the part of the supplier. Beyond the legal red tape, herbal medicine has proven more difficult to regulate than its synthetic counterpart. The quality of an herbal product is dependent upon a host of interrelated factors, many of which are not easily isolated and studied. Some examples of these mitigating factors include the fact that plants are often mislabeled, the specific species used for the extraction vary, and the methods of harvesting and processing differ greatly. Numerous studies have shown wide discrepancies between the advertised amount of active ingredient in many commercially available nutraceutical and the actual content. Furthermore, prescription medications have been found in ostensibly natural products, and heavy metals with the potential to cause arsenic or lead poisoning are occasionally discovered in products imported from Asia. The inclusion of the metals is at times intentional, as they are believed to accelerate the healing process, and at times reflects the factory parts where the product is made. Due to the lack of regulatory structure for herbal medications, there tends to be dramatic variation in the quality of available products. This can have huge implications in the safety and efficacy of these prod-
ucts. Quality of herbal products is determined by many variables, all of which can affect their clinical use and safety. Plant species, parts used, harvesting, storage conditions, processing and accuracy of labeling all can have a huge impact on the consistency and standardization of herbs. The pharmacologic potency of herbs may be dependent on how and where it was harvested, storage length and condition and by processing techniques. This leads to variation of similar products even within manufacturing plants. There are also many reports of inaccurate labeling and lack of product standardization and content. One study found that close to 40 percent of products were insufficiently or inconsistently labeled and that there were huge variations in recommended dosing. While controlled trials have demonstrated the superiority of some natural remedies when compared to placebo, some have led to adverse effects. One of the most-documented examples of this is the herb ephedra, or Ma Huang. A compound with similar properties to amphetamine, ephedra is often combined with guarana (caffeine) to promote weight loss or to boost athletic ability. Ephedra was also the primary ingredient in herbal Fen-Phen, marketed as a natural alternative to the antiobesity drugs fenfluramine and phentermine. Between 1994 and 1997, the FDA investigated over 800 claims of adverse effects, including death, myocardial infarctions, and cerebrovascular accidents, and in 2004 the sale of ephedra-containing products was banned (this was later overturned in court by the manufacturer, who argued successfully that the FDA did not have jurisdiction in herbal products, and needed to prove ephedra was unsafe). Not all adverse effects are as easily documented, however. While research is ongoing, evidence of traditional and conventional medicines interacting has surfaced through case reports and in vitro studies. St. John’s wort, while proven efficacious as an antidepressant in treatment of mild to moderate depression, appears to interact with oral contraceptives, anticoagulants, digoxin, antiviral agents, and cyclosporine, as well as anesthetic agents used prior to surgery. The challenge faced by the modern physician lies in reconciling the growing use of herbal remedies by the public with the lack of a sufficient set of data regarding their efficacy and potential adverse effects and interactions.
Integrating Herbal and Conventional Medicine Combining traditional herbal remedies with modern scientific advances is not a new concept for American physicians. The first United States Pharmacopoeia, published in 1820, was comprised of over 65 percent natural substances. As those medicines became increasingly replaced by modern pharmaceuticals, however, a comprehensive knowledge of their effects and uses was no longer seen to be a necessary part of a medical education. Currently the divide between the two forms of healthcare is sufficiently wide that a recent survey found most primary care providers unaware of their patient’s herbal intake and most patients unlikely to discuss their use of alternative remedies with their doctor even in the event of an adverse experience. In an effort to close this gap, some medical schools have begun to offer courses in CAM modalities. The 2002 White House Commission on Complementary and Alternative Medicine Policy (WHCCAMP) recommended increased funding and incentives for CAM research and improved protections for participants in those studies; WHCCAMP also specifically noted the importance of an open and integrative dialogue between traditional and conventional medical practitioners. Popular Herbal Remedies According to the 2002 National Health Interview Survey (NHIS), the most frequently used herbal medicines were echinacea, ginseng, ginkgo biloba, garlic, St. John’s wort, peppermint, ginger root, and soy. The following section discusses purported (not all have been proven efficacious) uses of several products. This should not be taken as medical advice to treat a medical condition, and is for informational purposes only. Echinacea The 2002 NHIS rated echinacea as the most popular herbal remedy, and its domestic sales totaled $70 million in 1998. There are nine species of the plant, including Echinacea purpurea, E. pallida, and E. angustifolia, commonly utilized to treat or prevent the common cold. A large NCCAM study recently did not reveal echinacea to be of benefit to reduce symptoms of the common cold, but research continues. The roots are part of the pharmacologically active part of the plant, and their consumption is thought to
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stimulate the immune system through a higher macrophage production rate. Echinacea is also used as a local anesthetic and antiinflammatory agent when applied topically. Doctors should discourage the use of this plant by patients with allergies, asthma, atopy, autoimmune disorders, or transplants, as there is a theoretical risk worsening those conditions, or precipitating an attack on the newly transplanted organ. Ginseng The second most popular herbal remedy according the 2002 NIHS, ginseng stimulates the central nervous system and increases glycogen storage. The World Health Organization (WHO) has approved its use as an agent to combat fatigue and stress, and the results of small studies of its effectiveness have been promising but inconclusive. Studies continue for the use of ginseng in patients with diabetes. There are many reports of mislabeling of ginseng, and some products on the market labeled as ginseng do not contain any active product. Ginkgo biloba This medicine accounted for the highest sales figure in the 1998 study ($151 million). The leaf is the active part of the plant, and many distributors claim that its ingestion will increase blood fluidity and improve memory function. A recent test involving a 230-person trial group found no improvement in memory, learning, attention, or concentration compared to a placebo, but other studies have indicated that ginkgo helps reverse the effects of tinnitus. It may be of use in mild-moderate dementia, as it works by improving blood flow to the brain. This effect is also responsible for the side effect of bleeding. Garlic Garlic is often advertised as an immune enhancer and a check against high cholesterol levels. While the WHO, among other groups, has sanctioned its use in the treatment of hyperlipidemia, other studies have been mixed. Garlic supplements should not be taken in extremely large doses within the week prior to a surgery due to potential platelet inhibition. Usual dietary doses are unlikely to have an adverse bleeding effect. St. John’s wort St. John’s wort accounted for nearly $140 million in sales in 1998, and the history of its use stretches back
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at least as far as Hippocrates’ account from the 5th century b.c.e. Its active ingredients (hypericin and hyperforin) help to combat depression. Over a dozen clinical trials have shown it to be significantly more effective than a placebo and comparable in effect to imipramine. While the current body of evidence implies that its use is fairly safe, St. John’s wort should not be taken in conjunction with other antidepressants, and the usual precautions that are taken to assess the patient for bipolar disorder must be adhered to as well in order to avoid precipitating a manic state. Peppermint The use of peppermint oil (primarily composed of menthol and menthone) may aid in the treatment of shingles, gingivitis, and indigestion. When combined with caraway oils, multiple double-blind trials have indicated that it can reduce the negative effects of irritable bowel syndrome. Its use is generally safe, but patients with gallstones, liver damage, or chronic heartburn should be wary. Ginger The rhizome (stem) of the ginger plant has achieved widespread use as a spice and as a remedy for a variety of ills. Studies have found the ingestion of ginger to be helpful in the treatment of motion sickness and osteoarthritis, and when used in conjunction with other natural substances it may help fight epilepsy and various kinds of nausea, especially the nausea and vomiting associated with pregnancy. Soy Soy has gained popularity as a milk substitute, and it is commonly used in the prevention of osteoporosis and the treatment of high blood pressure or cholesterol, although results of studies for these purposes are mixed. In addition, patients would have to drink a lot (five to 10 glasses) of soymilk or eat a lot (two and a half cups) of tofu in order to obtain the same effects as a 0.3 mg pill of conjugated estrogen. Some research has indicated that soy may help prevent the onset of cancer, but results are inconclusive. Saw Palmetto Saw palmetto has been used to treat urinary disorders for over 17,000 years. In Germany, a patient with mildmoderate benign prostatic hyperplasia (BPH) would be
Twenty to 30 percent of the medicinal products in the United States are derived from botanicals.
more likely to be advised to take saw palmetto than a traditional prescription medication. Studies have shown it is efficacious for the short-term treatment of mild-moderate BPH, and often with fewer side effects than some prescription medications used for this purpose. As the push toward evidence based medicine drives further research into the use, efficacy, side effects, interactions and safety of herbal medications, physicians and consumers will be able to more confidently utilize these as another tool in the fight against disease. Problems remain, as herbal products cannot be patented, hence, corporations may be unwilling to spend millions of research dollars to prove the efficacy of these products and not see a return on investment. Also, the lack of standardization remains a problem , as patients may receive varying amounts of active ingredients from month to month. SEE ALSO: Herbal Remedy; National Center for Comple-
mentary and Alternative Medicine (NCCAM); Pharmacology. Bibliography. E. Ernst, ������� Harmless herbs? A review of re-
cent literature.American Journal of Medicine (v.104, 1998); C.A. Newall, L.A. Anderson, and J.D. Phillipson, Herbal Medicines. A Guide for Healthcare Professional (The Pharmaceutical Press, 1996); Robert Saper, “Overview of Herbal
Herbal Remedy
Medicine,” www.uptodate.com (cited October 17, 2006); U.M. Thatte, et al., The Flip Side of Ayurveda. ����������� Journal of Postgraduate Medicine (v.39, 1993). Gautam J. Desai, D.O. Ingrid Y. Madjar Kansas City University of Medicine and Biosciences College of Osteopathic Medicine Shamoli Khanderia, D.O., Pharm.D. Private Practice Physician
Herbal Remedy Many Americans turn to herbal remedies, either in conjunction with, or in place of, prescription medication, to treat various ailments. These products are advertised in the popular media, as well as in health food stores. The purity and efficacy of many remedies remain in question, as research is only now commencing in earnest on many herbal products in the United States. Over 80 percent of the medicinal products in the United States during the early 1800s were derived from botanicals; today, this number is only 20 to 30 percent. The use of plant extracts for medicinal purposes is termed phytotherapy, and there are various formulations of herbal remedies, including liquid, dry, powdered, distillations, and fresh parts of the herb. Herbal remedies may be ingested or applied topically. Various portions of the plant may be used, including the flowers, leaves, roots, and stems, depending on the species and intended use. Often, closely related species are included in common herbal products, which may cause problems in the intended use. There are nine species of the herb echinacea—commercial products often contain three or more species, each with distinct pharmacologic properties. Variation in active ingredient between bottles may cause a change in clinical effects based on the product used, even if from the same manufacturer. Different plant parts (roots, stems, leaves) from the same herb also may have variable properties and are rarely differentiated in herbal products. Special populations that must take care when using herbal remedies are geriatric patients, children, and pregnant/breastfeeding patients. The elderly may be on multiple medications, which can increase their chanc-
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es of an interaction. Children are more susceptible to toxins, as they are still developing. Few studies exist on pregnant or lactating patients regarding the use of herbal products and their effects on the fetus/newborn. Examples of herbal remedies and their purported uses (some of which have not been verified through research) include: 1. Saw Palmetto: benign prostatic hypertrophy 2. St. John’s wort: mild depression 3. Ginger root: nausea and vomiting of pregnancy 4. Echinacea: to enhance the immune system Examples of herbal remedies and possible side effects/interactions include: ginkgo biloba interacting with warfarin to cause easier bleeding, and St. John’s wort interacting with anesthetics prior to surgery. Unlike prescription medication, herbal medicines are not tested by the Food and Drug Administration (FDA) for purity, efficacy, or content. Often, testing of herbal products reveals less active ingredient than is advertised on the label. Even within samples produced by the same manufacturer, the amount of active ingredient may vary, which may have an effect on the purported use, so the public needs to be aware of the risk/benefit ratio prior to choosing a herbal remedy. This is especially true for those at higher risk for an adverse reaction/interaction—the young, elderly, and breastfeeding/pregnant patients. SEE ALSO: Herbal Medicine; National Center for Com-
plementary and Alternative Medicine (NCCAM); Pharmacology. BIBLIOGRAPHY. Ellen Hughes, Bradly Jacobs, and Bri-
an Berman, Current Medical Diagnosis and Treatment, Complementary and Alternative Medicine 2006, www.accessmedicine.com (cited October 2006); Robert Saper, “An Overview of Herbal Medicine,” www.uptodate.com (cited October 2006). Gautam J. Desai, D.O. Pinaki N. Patel, MS III Kansas City University of Medicine and Biosciences College of Osteopathic Medicine Shamoli Khanderia, D.O., Pharm.D. Private Practice Physician, Denver, Colorado Shelley L. Alexander, D.O. University of Missouri–Kansas City School of Medicine
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Herbalism Herbal medical practice in North America draws primarily on traditions from native healers of this continent and Europe, and secondarily from eastern Asia and the Indian subcontinent. Much less common in North America are those herbal traditions native to Africa, Australia, or the various island kingdoms. All herbal traditions use plants variously prepared to treat patient symptoms. European Tradition An archaeological find in present-day Iraq from a 60,000-year-old burial site shows drawings of Althea and Achillea, botanicals used today. Cuneiform tablets from Iraq dating to 4000 b.c.e. show such medicines as Glycyrrhiza, Papaver, Thymus, and Brassica. An Egyptian papyrus from the 16th century b.c.e contains some 800 recipes and over 700 plants, treatments for diabetes, and the use of mudpacks for open sores. Hippocrates, the Greek father of medicine, wrote in 400 b.c.e about the medical use of over 300 plants. Theophrastus (371–287 b.c.e) wrote Inquiry into Plants and Growth of Plants, describing over 550 plants and their uses. The Greek physician Dioscorides in the 1st century c.e. authored De Materia Medica, cataloging the medical use of over 600 plants, 35 animals, and 90 minerals. Naturalist and botanist Pietro Mattioli of Venice reprinted it in 1544. Between 400 and 1500 c.e., the Catholic Church controlled medical knowledge and herbal medicines were grown administered by the clergy and knowledgeable laypeople. This changed with Church decrees that forced the clergy to focus on saving souls, and medical and herbal education to become a part of the early universities. English herbal tradition was legalized under Henry VIII in 1541 under the Herbalist Charter. It preserved the use of herbs for the King and all of his subjects. The best lexicon of these plants was The Herbal (The English Physitian [Physician]) of 1652 produced by Nicholas Culpeper (1616–54) who began his herbal practice as a physician in 1640. It described various botanicals, their harvesting, preparation, and use with a view to the astrological chart. A modern update to Culpeper that borrowed heavily without credit from King’s American Dispensatory was Maud Grieve’s A Modern Herbal published in 1931. It provided information on the medicinal, culinary, cosmetic, cultiva-
tion, and economic uses of some 800 herbs. Between Culpeper and Grieves was Carl von Linne (1701–78) who set about to categorize every plant, animal, and mineral. He established botanical taxonomy and the use of a Latin binomial consisting of genus and species (e.g., Echinacea angustifolia, Taraxacum officinale) to describe every plant. This system has become a universal language for naming all plants (and animals) including those used in herbalism. Eclectic Tradition Constantine Rafinesque (1784–1841), a botanist and advocate of herbs as medicines, explored the Mississippi River Valley learning from the various American Indian communities what plants were used, how they were prepared, and for what conditions. He is credited as the first to use the term eclectic meaning “to adopt into practice what is beneficial.” Explorers, trappers, and early settlers traveling west along the Oregon Trail and other routes adopted from the various Indian tribes many more herbs (e.g., Artemisia, Arctostaphylos, Lomatium, Vaccinium, etc.) and used them daily. An estimated 90 percent of the North American medicinal herbs used here and in Europe came from east of the Mississippi River with 75 percent from the Appalachian forests. Botanical diversity in the Mississippi drainage and regions to the east is greater than that of the Rocky Mountains and lands to the west. Native American traditions were mainly oral, so few texts exist. The single best reference on Native American herbs and their use is by Moerman. This reference is organized alphabetically by species, indicating its use as a drug, food, fiber, dye, and other uses, and within these categories by tribe and how they specifically used the plant. This text includes over 4,000 plants, from 1,200 genera and their use by 291 different societies from the North American Arctic to Mexico. Wooster Beach (1794–1868) apprenticed with Jacob Tidd, a German herbal doctor, until Tidd’s death and then graduated from Barclay Street Medical University, New York. He wanted to reform the then-current heroic medical treatments of bleeding and mercury chloride (calomel) to the use of herbal medicines. His enthusiastic efforts led him to being ostracized by the New York State Medical Society and it was their political clout that helped deny him the necessary charter to establish a college and grant legitimate medical diplo-
mas in the state of New York. Worthington College, Worthington, Ohio, was a financially ailing chartered school that he transformed into the Reformed Medical College in 1831. In 1855, it moved and became the Eclectic Medical Institute of Cincinnati, Ohio. This institution graduated its last class in 1939 as World War II was beginning. The eclectic tradition with respect to use of botanical medicines was adopted by naturopathic medicine which now has four-year full-time colleges in Canada (two schools), United States (five schools), and England, and three-year full-time colleges in South Africa, Australia, India, and New Zealand. The World Health Organization is preparing a monograph on naturopathic medical education and how botanical medicine is incorporated into its training and clinical practice. The Eclectic School was responsible through the effort of John Uri Lloyd (1849–1936) in advancing pharmacognosy, the study of plant constituents and their use as medicines. Lloyd published over 5,000 papers mainly on plant constituents and held 16 patents, inventing devices for botanical extraction and preparation. King’s American Dispensatory, first published in 1855 by John King, was a detailed catalogue of constituents, actions, indications, doses, and more on the hundreds of plants used by eclectic physicians. The revised edition was edited by Harvey Wickes Felter and Lloyd and released as a two-volume reference in 1898 and reprinted in 1983. Today’s popular botanicals, Echinacea, Crataegus, Hypericum, Hydrastis, and so forth, and many lesser known herbs, Ampelopsis, Aspidosperma, Menispermum, Sterculias, and so forth, were described with detail in King’s. John Milton Scudder (1829–94) undertook an ambitious project to publish the specific patient signs and symptoms and clinical indications for these plants, leaving aside any effect not directly attributed to the action of the botanical medicine. Thomson and Physiomedical Tradition Samuel Thomson (1769–1843), a poor New Hampshire farmer, claimed to have learned herbal medicine from the local Indians. His theories were largely his own and led to the Thomsonian system with an underlying philosophy of self-treatment. Thomson published New Guide to Health in 1822 and sold it plus a kit of medicines for home or family use under
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patent protection for $20; he claimed 100,000 families purchased the kit. Alva Curtis, MD (1797–1881), worked as editor for the Thomson Recorder, another of his publications, but viewed the ill-effects of the large doses of powerful emetics (Lobelia inflata) and warming herbs (Capsicum frutescens) as too strong. She left and formed physiomedicalism. The tenets of physiomedicalism were 1.) cure of disease must conform to the laws of life and assist nature, 2.) no poisonous substance could be used in treatment, 3.) practitioners should be scientifically educated (unlike Thomson), and 4.) botanical medicines should be studied to determine their effect. The Physio-Medical Institute, Cincinnati, Ohio, was short lived, but its philosophy survived in England, becoming the basis of the National Institute of Medical Herbalist, now a four-year full-time course at the University of Wales. The physiomedical philosophy blended well with the strong British herbal tradition. The British use of herbs dates back to the Druids and before and is a blend with the herbal traditions brought by various invaders of the British Isles including the Vikings and the Romans. Asian Traditions Chinese medicine, arguably one of the oldest, most systematized medicines of the world, is based on a distinct philosophy of the human body and how it interacts or reacts to its environment with respect to its overall health. Important to the medicine are 1.) yin and yang (philosophical polar constructs representing cold, rest, darkness or passive, interior and hot, activity, light or vigor exterior, respectively); 2.) fundamental substances such as qi (matter on the verge of becoming energy), blood (a circulating yin fluid that nourishes, moistens, and maintains the body), jing (congenital essence inherited from parents and vitality from ingested food), and body fluids (nonblood fluids such as saliva, gastric juices, urine); 3.) organs, heart, spleen, triple warmer (similar but not always identical to our Western definition), and so forth; 4.) meridians (channels that carry blood, but not blood vessels, and chi through the body connecting the organs); and 5.) conditions that cause disharmony (disease) such as wind (a yang phenomenon that generates movement, change, and urgency), heat (a yang phenomenon in which the patient is hot), cold (a yin phenomenon in which the patient is cold), dampness (a yin phenomenon producing
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Herbalism
heaviness, discharges, or obstructions to the movement of qi), and so forth. Shan Ching from 250 b.c.e. and Hai Ching from 120 b.c.e are their oldest extant medical texts with 52 diseases and 283 prescriptions using 247 drugs, mostly plants; all are still used today. A copy of Shen Nung Pen Tsao Ching from 500 c.e. enumerated 365 herbs, Hsin Hsiu Pen Tsao from 659 c.e. contained 850 medicinal substances in 27 volumes, Kai Pao Pen Tsao of 973 c.e. listed 984 herbs, its 1057 c.e. edition 1,084 herbs, and the 1590 c.e. edition 1,518 medicines including 374 new herbs. Chung Yao Ta Tsu Tien, the People’s Republic of China’s dictionary of Chinese herb drugs, lists 5,767 different medicinal substances, mostly plants of which 235 species are used commonly and almost daily. Herbal combinations (including mineral and animal substances) are prescribed to counter the patient’s conditions or diagnosis as well as for building up the patient’s resistance to his or her diagnosis/condition. The kampo formulas and medical philosophy of Japan and other Asian medical systems (Tibet, Korea, Thailand, Vietnam) are similar but distinct from traditional Chinese medicine. Ayurvedic Tradition Ayurvedic medicine, the traditional medicine of the Indian subcontinent, is similar in age to Chinese medicine and provides healthcare to about 70 percent of the population. It was built on an oral tradition where medical students had to memorize over 45,000 verses until Atreya Samhita was written in Sanskrit circa 500 b.c.e. Ayurvedic medicine has eight major disciplines including internal medicine, surgery, gynecology and pediatrics, gerontology, psychiatry, sexology/fertility, toxicology of medicinal substances, and medicine and surgery of the head. The materia medica consists of over 1,000 plants plus minerals and animal substances. The principles of Vata (movement, breathing, animation, activity), Pitta (energy released from biochemical processes, digestion, vision), and Kapha (stability, form, cohesion, mental strength, disease resistance) aid in patient diagnosis and prescriptions to evacuate (parasites), stop elimination (hemostatics, diarrhea), modify the temperament, and effect the disease. Summary Each of these herbal traditions thrives within a multicultural North America. Occasionally, the plants
used will overlap traditional boundaries with slightly different indications (e.g., Allium, Zingiber, Glycyrrhiza, Arctium, etc.). Within each tradition, the herbalist writes a formula of one to 10 herbs specific to the patient’s diagnosis. The herbal practitioner may prepare the formula or give directions to the patient for its preparation and administration. Many herbalists still grow or wild-craft their herbs. These methods of herbal administration may include infusions, decoctions, tinctures, fluid extracts, salves, ointments, suppositories, vapors, essential oils, encapsulations, standardized extracts, or constituent extracts. Some herbal practitioners will also use traditional or “patent” formula with a long history of use that are described in older texts, while others will prepare a specific formula for a specific patient and his or her condition. Each herbal tradition was also very aware of poisonous plants and how to avoid them or prepare for use in a nontoxic manner (e.g., Aconitum napellus, Digitalis spp., Atropa belladonna, Datura stramonium). In addition, the herbalist must be aware of real or potential negative and positive interactions between the herbal prescription and any prescribed or over-the-counter medications the patient is taking. The rich tradition of herbalism has provided us with many currently used drugs (e.g., reserpine, digoxin, taxol, vincristine) and will no doubt lead to future discoveries that will benefit humankind. SEE ALSO: Alternative Medicine; Chinese Medicine, Tra-
ditional.
Bibliography. H.A. Baer, “The Potential Rejuvenation
of American Naturopathy as a Consequence of the Holistic Health Movement,” Medical Anthropology (v.13, 1992); D. Bensky and A. Gamble, Chinese Herbal Medicine Materia Medica, rev. ed. (Eastland Press, 1993); W. Boyle, Herb Doctors: Pioneers in Nineteenth Century Botanical Medicine (Buckeye Naturopathic Press, 1988); F. Brinker, Herb Contraindications and Drug Interactions (Eclectic Medical Publications, 2001); F. Brinker, Native Healing Gifts: Rediscovering Indigenous Plant Medicines of the Greater Southwest (Eclectic Medical Publications, 1995); F. Brinker, Pioneers, Plants and Medicines along the Oregon Trail (Eclectic Medical Publications, 1993); H.G.M. Chishti, The Traditional Healer (Healing Arts Press, 1988); G. Cody, “History of Naturopathic Medi-
Herbalist
cine,” in J. Pizzorno and M. Murray, eds., Textbook of Natural Medicine (Bastyr University Press, 1985); W. H. Cook, The Physiomedical Dispensatory (Eclectic Medical Publications, 1998); N. Culpeper, Culpeper’s Complete Herbal (Foulsham, 1640); I. N. Dobelis, Magic and Medicine of Plants (Reader’s Digest Association, 1986); F. W. Felter and J. U. Lloyd, King’s American Dispensatory, 18th ed. (Eclectic Medical Publications, 1983); J. Filliozat, The Classical Doctrine of Indian Medicine (B. Jain, 1964); M. Grieve, A Modern Herbal (Tiger Books, 1931); B. Griggs, Green Pharmacy (Jill, Norman and Hobhouse, 1981); B. Heyn, Ayurvedic Medicine (Thorson’s, 1987). Paul Richard Saunders, Ph.D., N.D., DHANP Canadian College of Naturopathic Medicine
Herbalist A herbalist is a person who prescribes primarily herbal remedies for various medical ailments. The practice is very old and may be dated to two millennia b.c.e in Egypt and China. It continues to be popular in China and east Asian countries, although from the time of the Industrial Revolution, the practice became increasingly discredited in Western countries as new scientific techniques seized the imagination of people in those countries. In modern times, herbalists have received something of an upturn in fortunes because many people have come to feel that Western medicine is too reliant on chemical sciences which cannot be trusted and which are mediated by pharmaceutical companies that have dubious intentions. Nevertheless, at the heart of herbalism is a belief in the restorative or curative powers of herbs which, in many cases, has no verifiable basis and, in other cases, obscures potentially dangerous side effects. Because a herbalist is required to be able to recognize a wide range of plants and to identify their specific uses, it as customary in preindustrial societies for the herbalist, possibly in addition to other religious or sacred duties, to spend years studying the art, perhaps as an apprentice to an older herbalist. In some societies, women were able to enter the profession, perhaps as part of duties which also included midwifery. At a basic level, the herbalist would have been required to
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identify safe and unsafe wild plants and to advise on pain relief and health-giving preparations. In countries where poppies grew, opium became known as a method of pain relief and other examples exist of herbal remedies actually performing the functions required of them, although they may have undesirable side effects and other issues. In other cases, societies became dependent on particular herbs and attributed great power to them even though no scientific evidence for their efficacy exists. An example of this is the use of ginseng in Korea, which is prescribed for a very wide range of ailments and generally believed to have numerous benefits, although these have yet to be substantiated in laboratories. In other cases still, herbalists used items that have subsequently come to be used in different but genuinely efficacious ways. The impact of quinine on preventing the spread of malaria, for example, has become well known. Irrespective of the demonstrated ability of herbalists to prescribe effective treatments, it is certainly true that the decoupling of many people from the land on which they live has led to a number of negative impacts, not least of which is loss of knowledge about local plants and flowers. Local wisdom may still be useful in the modern world and, as the pace of global climate change and environmental degradation intensifies, it would be unfortunate if knowledge of plants becomes extinct, as well as the plants themselves. Western medicine should be chosen over the prescriptions of herbalists because evidence exists of its effectiveness, which may be repeated in laboratory conditions and because of the study of side effects or interactions with other substances. Furthermore, medicine deriving from companies that adhere to strict government regulations is much more likely to have strict quality-control issues which ensure that it is of the same, advertised strength and quality on a consistent basis. SEE ALSO: Herbal Medicine; Herbal Remedy; Herbalism. Bibliography. W. Boyle, Herb Doctors: Pioneers in Nine-
teenth Century Botanical Medicine (Buckeye Naturopathic Press, 1988); Robert Saper, “An Overview of Herbal Medicine,” www.uptodate.com (cited June 2007).
John Walsh Shinawatra University
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Hernia
Hernia The term hernia is used to describe the protrusion of a body part or organ through an opening or defect in the fascia, muscle, or wall of a cavity. The fibrous lining of the abdominal cavity that supports, separates, and unites the muscles and tissues is known as fascia. In a hernia, the involved body part or organ is usually contained within the confines of the cavity, and upon herniation, is considered out of place. Hernias are generally found in the abdominal cavity, and can be asymptomatic or may produce a lump, ache, pain, or bulge at rest or with straining. A defect or opening in fascia can be congenital or acquired. Hernias can be lined or covered with tissue and this is known as a hernia sac. Activities and conditions that increase the intraabdominal pressure such as heavy lifting, pregnancy, and obesity can lead to or accentuate an abdominal wall weakness manifesting itself as a hernia. There are several descriptive terms used to further classify hernias. A reducible hernia is one that returns to the cavity where it belongs via an application of pressure to it, or from a positional change. An incarcerated hernia is one that becomes trapped and cannot be reduced or returned to the cavity. When an incarcerated hernia becomes squeezed in such a way that blood supply to the organ or body part is compromised, it is known as a strangulated hernia. This is a condition that requires immediate surgical intervention. Hernias are also described by their anatomic location. For example, a scrotal hernia describes a protrusion into the scrotum. Hernias of the lower abdominal wall can occur in the groin and are known as either inguinal or femoral hernias, depending on specific anatomical location. Femoral hernias are more common in women than men. Groin hernias are the most common type of hernia. Inguinal hernias are further classified as direct or indirect based again on specific anatomical considerations, and how and where the protrusion occurs. Congenital and acquired umbilical hernias occur at the umbilicus due to a defect in the ventral abdominal wall and are commonly seen in obese people and pregnant women. Umbilical hernias can resolve spontaneously in children without sequelae, but frequently incarcerate or strangulate in adults. A hernia that appears at the area of a previous surgical site is known as an incisional hernia. A phrenic hernia occurs when an organ protrudes through
the diaphragm. The hiatus (opening) of the diaphragm where the esophagus passes through can be the site of a hernia. The stomach may herniate or protrude through this opening resulting in a hiatal hernia. This type of hernia is considered a sliding hernia if it returns or slides back into the cavity where it belongs. Other types of abdominal hernias may also be sliding hernias. Hernias can contain part or all of an organ inside the abnormal protrusion. For example, a Richter’s hernia describes a hernia in the abdominal cavity where only part of the bowel circumference is involved. If the brain protrudes where it does not belong, it is called a cerebral hernia. Hernias are also named for the organ that is out of place. For example, an ovarian hernia contains an ovary as the misplaced and protruding organ. The only way to correct a hernia is with surgery, and this is known as herniorrhaphy. There are several different techniques used to repair abdominal wall and groin hernias such as various suture methods, surgical mesh placement, and laparoscopic repair. The best surgical technique for hernia repair remains controversial. Herniorrhaphy is one of the most frequently performed general surgery procedures. The diagnosis of hernia is frequently made clinically based on physical examination, but imaging modalities do exist to confirm, elaborate, and aid in diagnosis. Complications associated with hernia repair include recurrence, infection, bleeding, and pain. Complications associated with not repairing abdominal wall and groin hernias include a small risk of incarceration and strangulation and thus a surgical emergency. The surgical correction of an uncomplicated, asymptomatic hernia versus watchful waiting remains a decision between the surgeon and the informed patient. SEE ALSO: Gastroesophageal Reflux/Hiatal Hernia. Bibliography. David C. Brooks, “Abdominal Wall and
Groin Hernias,” www.utdol.com (cited January 19, 2006); Karen E. Deveney, “Chapter 32. Hernias and Other Lesions of the Abdominal Wall,” www.accessmedicine.com (cited 2006); Donald Venes, ed., Taber’s Cyclopedic Medical Dictionary, 20th ed. (F. A. Davis, 2005). W. Joshua Cox, D.O. Kansas City University of Medicine and Biosciences
Heroin Abuse
Heroin Abuse
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The illicit use of heroin is an important international health concern, especially in light of evidence showing that unsafe drug injection practices lead to transmission of the human immunodeficiency virus (HIV), the virus causing the acquired immunodeficiency syndrome (AIDS), as well as other deadly diseases. Heroin is a semisynthesized drug that is processed from morphine, a natural derivative of the poppy seed plant, and is readily produced and distributed in multiple countries worldwide. Globally, approximately 11 million people are estimated to abuse heroin. In the United States, heroin use is illegal and is classified as a Drug Enforcement Agency (DEA) Schedule I drug, meaning that heroin has a high potential for abuse, is available for research purposes only, and has no approved medical indication. The drug is sold on the street as a white or brown powder, or as a thick, black, tacky substance. Often, the drug is not pure but is mixed or “cut” with other substances such as sugar, starch, milk, quinine, or other drugs. Therefore, the actual potency of illegally acquired heroin varies widely, placing the user at risk of overdose and death. Heroin can be injected intravenously, snorted nasally, or smoked. Injection is usually the most common route of administration, although in some locations, inhalation occurs more frequently. In general, intravenous injection produces a more intense pleasurable feeling and exhibits quicker onset of drug effect than sniffing or smoking.
because poorly dissolved additives present in street heroin can travel through the blood stream, embolizing in the lungs, liver, kidneys, or brain, causing tissues in these organs to infarct, or die. The veins of repeated injectors can become collapsed, causing the user to seek out other veins, sometimes including those of the neck. There is a high risk of infection associated with injection because sterile needles are not often available, and endocarditis (infection of the heart lining and valves), pneumonia, bone and joint infections, and abscesses of the skin and other organs can occur. Users who share needles with others can acquire and transmit bloodborne viruses such as HIV and the hepatitis viruses B and C, which can cause long-standing liver disease, cirrhosis, and ultimately, liver failure requiring transplantation. Addiction to heroin is marked by tolerance and withdrawal. Tolerance is achieving less drug effect after taking a dose similar to previous administrations, or stated another way, requiring more drug to experience the same effect as before. Withdrawal is a syndrome of physiological effects that the user experiences after taking heroin for a long period of time, then stopping. It is marked by craving, restlessness, muscle and bone pain, insomnia, diarrhea, vomiting, kicking movements, cold flashes, and goose bumps. It is based on this constellation of effects that the terms “kicking the habit” and “going cold turkey” were coined. Although intensely unpleasurable for the addict, heroin withdrawal, unlike withdrawal from alcohol or barbiturate abuse, is generally not fatal.
Drug Effects After a single dose of heroin, the user experiences a surge of euphoria or a “rush,” as well as a warm flushing of the skin. Profound relief of pain, if any is present, takes place. The mouth becomes dry and the extremities begin to feel heavy. Pupils become very small, respiratory rate decreases, and gastrointestinal motility slows, causing constipation. Central nervous system effects include drowsiness and confusion, and in overdose, can progress to unconsciousness, coma, and ultimately, death. Alternating wakeful and drowsy states can also occur, a phenomenon known as being “on the nod.” Immediate and long-term risks are associated with heroin use. The most important of these is overdose. The practice of injection is also inherently dangerous,
Treatment Acutely intoxicated users at risk of overdose can be administered naloxone or naltrexone, compounds that block the effects of opiates in the body. These compounds do little to treat addiction, however. Heroin users represent close to 15 percent of admissions to publicly funded substance abuse treatment programs in the United States. It is important to realize that no single treatment is appropriate for all individuals, and drug users often relapse into their old habits, requiring multiple attempts at treatment. The process can take months to years, and must carefully address the multiple needs of the user, not just his or her addiction. The first step in treatment is often detoxification, a process in which the patient is safely weaned from his
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Heroin Abuse behaviors about drug use and to teach effective life skills. Family therapy in which abuse is confronted by the entire family of an adolescent heroin user, may also be employed.
It is estimated that approximately 11 million people abuse heroin, which can be injected intravenously, snorted nasally, or smoked.
or her addiction while minimizing or alleviating the symptoms of withdrawal. By itself, detoxification is not treatment. After, a combined therapy is generally employed in which medication, cognitive behavioral therapy, and social support are central components. The most common medications for heroin addiction include methadone and buprenorphine. These compounds partially block the receptors within the body on which heroin normally acts. The net effect, therefore, is to reduce withdrawal symptoms (especially craving) while also blocking the effects of continued heroin usage among those who do continue to abuse the drug. These compounds have some addiction potential, causing some to argue that they should not be used, but they can be safely tapered off over a period of time to avoid this effect. Methadone and buprenorphine can be safely used in pregnancy, although newborns exposed in utero to these compounds may require careful treatment for withdrawal from them. Effective cognitive behavioral therapy is also important to the recovering heroin user, and includes residential and outpatient approaches. Cognitive behavioral therapy helps patients appreciate the circumstances that often lead them to use heroin, and helps them safely avoid these situations or effectively cope with them. Counselors are also trained to help patients modify their attitudes and
Societal/Global Impact In the United States, more than half of drug-related costs to society are attributed to crime associated with drug use. The immediate costs of crime include the price of police, legal and correction services, and federal drug traffic control, as well as less immediate consequences, such as lost productivity of perpetrators and victims, and importantly, healthcare expenditures for intentional and unintentional injuries. The burden of injection drug use-related disease is high. As mentioned earlier, needle sharing can lead to transmission of HIV and hepatitis B and C, diseases with important public health consequences. For example, in the United States, 70 to 80 percent of new cases of hepatitis C, the most common reason for end-stage liver disease requiring transplantation, are attributable to unsafe injection drug use. Minority groups, including African Americans and Hispanics, are particularly vulnerable and show higher rates of disease than other members of the population. It is believed that worldwide, production of heroin has more than doubled or even tripled since 1985. Three major production and trafficking routes exist: (1) from Afghanistan to nearby countries in the Middle East and eastern Europe; (2) from Burma and Laos to China and Oceania (especially Australia); and (3) from Latin America, including Mexico, Colombia, and Peru, to North America. Of the nations in which heroin is illegally produced, Afghanistan is the leader worldwide, followed by Burma and Laos. Following years of variable growth, illicit opium poppy cultivation decreased in 2005. Globally, 16 million people abuse opiates, and 11 million abuse heroin. More than half of these users live in Asia, and the highest rates of abuse are found along trafficking routes originating in Afghanistan. Although Afghanistan and eastern and southeast Europe showed increases in the prevalence of heroin use, the global trend leveled off in the early 21st century. This was predominately due to falling levels of opiate abuse in east and southeast Asia and Oceania. Nonetheless, unsafe injection drug use represents an important and often neglected cause of HIV transmission, especially in Asia.
Herpes Simplex
Harm reduction is a philosophically different and practical approach that aims to mitigate the dangers of drug use. Proponents argue that often little can be done to decrease the actual prevalence of drug use, but much can be done to decrease the harms of usage. For example, making available sterile syringes for heroin injectors decreases the transmission of bloodborne disease by reducing the need for needle sharing. Opponents of harm reduction believe that such activities facilitate and promote drug use. North America’s first supervised injection site was opened in Vancouver, Canada, in September 2003, and offers a safe environment for users to inject drugs and connect with healthcare professionals and addiction services. Heroin abuse remains a public health crisis worldwide. When compared to age-matched controls, heroin users worldwide demonstrate 20 to 30 times higher all-cause mortality, a fact that highlights the need for effective and innovative interventions that address the complexities of addiction and human behavior. SEE ALSO: AIDS; Drug Abuse; Hepatitis; Pregnancy and
Substance Abuse.
Bibliography. “NIDA—Research Report Series—Heroin
Abuse and Addiction,” www.nida.nih.gov (cited September 2006); “World Drug Report 2006—Executive Summary,” www.unodc.org (cited September 2006). Scott E. Hadland, M.D., M.P.H. Washington University School of Medicine
Herpes Simplex Herpes simplex virus (HSV) is a common virus affecting humans. It is perhaps best known as the cause of cold sores, the facial blisters that sometimes occur following a cold or fever. There are two types of herpes simplex viruses. Type 1 primarily involves the face and eyes and type 2 primarily causes genital infections. Each year in the United States, approximately 25 million people have flare-ups of facial herpes, and 5 million develop genital herpes. There are about 500,000 people in the United States with a history of herpetic eye disease. Transmission is
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via contact of infected secretions (saliva or genital) with mucous membranes or with open skin. HSV-2 is spread primarily sexually, and its rates are variable among different adult populations, depending on sexual behavior. After exposure, the virus replicates locally in the epithelial cells, causing lysis of the infected cells and producing an inflammatory response. This response results in the characteristic rash, which consists of small, thin-walled vesicles on an erythematous base. Continued replication results in viremia in immunocompromised hosts but rarely in normal hosts. Following primary infection, the virus becomes latent in a sensory nerve ganglion. Gingivostomatitis and pharyngitis are the most frequent clinical manifestations of first-episode HSV-1 infection, while recurrent herpes labialis is the most frequent clinical manifestation of reactivation HSV infection. HSV pharyngitis and gingivostomatitis usually result from primary infection and clinical symptoms and signs include fever, malaise, myalgias, inability to eat, irritability, and cervical adenopathy. Recurrent oral lesions occur in 60 to 90 percent of infected individuals, are usually milder, and generally occur on the lower lip at the outer vermilion border. The recurrences often are triggered by local trauma, sunburn, or stress. First-episode primary genital herpes is characterized by fever, headache, malaise, and myalgias. Pain, itching, dysuria, vaginal and urethral discharge, and tender inguinal lymphadenopathy are the predominant local symptoms. Widely spaced bilateral lesions of the external genitalia are characteristic. Lesions may be present in varying stages, including vesicles, pustules, or painful erythematous ulcers. The clinical courses of acute first-episode genital herpes among patients with HSV-1 and HSV-2 infections are similar. However, the recurrence rates of genital disease differ with the viral subtype: the 12-month recurrence rates among patients with first-episode HSV-2 and HSV-1 infections are 90 percent and 55 percent, respectively. HSV infection of the eye is the most frequent cause of corneal blindness in the United States. HSV keratitis presents with an acute onset of pain, blurring of vision, chemosis, conjunctivitis, and characteristic dendritic lesions of the cornea. Debridement, topical antiviral treatment, and/or interferon therapy hastens healing. However, recurrences are common, and the deeper structures of the eye may sustain immunopathologic
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Heterosexual
injury. Chorioretinitis, usually a manifestation of disseminated HSV infection, may occur in neonates or in patients with human immunodeficiency virus (HIV) infection. Many aspects of mucocutaneous and visceral HSV infections are amenable to antiviral chemotherapy, such as acyclovir, valacyclovir, and famciclovir. SEE ALSO: Eye Diseases (General); Sexually Transmitted
Diseases.
Bibliography. A.G.M. Langenberg, et al., “A Prospective
Study of New Infections with Herpes Simplex Virus Type 1 and Herpes Simplex Virus Type 2,” New England Journal of Medicine (v.341, 1999). Nakul Gupta Ross University School of Medicine
Heterosexual Heterosexuality is applied to the phenomenon of physical, aesthetical, or platonic attraction between people of different genders (mainly women and men, but because gender and sex are not the same, the spectrum of variables became wider). It is also used
The term heterosexual is used to refer to sexual activity with another person of the opposite sex.
to refer to the sexual activity with another person of the opposite sex. Therefore, heterosexual is the person whose sexual preferences, orientation, practices, and feelings were developed in the framework of his or her heterosexuality. Terminology The term comes from the Greek heteros, which means different. It was explicitly used for the first time at the end of the 19th century in opposition to homosexuality, because, also for the first time, heterosexual behavior was no longer perceived as the main model of intimate human relationships but as a possible identity among many other identities. Heterosexuality in Old Cultures Heterosexuality originates a vision of the sexuality understood in hierarchical terms: It was not a mutual feeling between equals but rather a relationship between an individual (usually a man) and his object of desire (usually a woman but not exclusively). Nevertheless, in the later Hellenistic period and in Roman times, there was a higher degree of freedom for women and it was observed in the production of objects destined for the pleasure of both, male and female, and simultaneously, it also became obvious in the erotic representations of heterosexual couples as equals, enjoying the same comfort and the same intense emotions. However, the main feature in heterosexual relationships from old times onward is its institutionalization and, therefore, the existence of an institutionalized inequality consisting in role differences and power distribution. In old mythology, females are submitted to the will of men and gods, and they only exist to be a recipient of their seeds and give children to them. Aristotle believed that only male seed could procreate; women were just mere receptacles. Heterosexuality as the Main Accepted Sexual All current experts, with no exception, agree that heterosexual behavior used to be a compulsory rule of behavior (based on the assumption that men and women are innately attracted to each other) and, therefore, the common pattern of sexual normality. For that same reason, there is no reliable statistics on it and heterosexuality was only in recent times a
Heterozygote
real object of study. Its basis and main purpose was procreation. First of all, because there was an implicit analogy with the animal world where sexual reproduction and the continuity of the species were natural results of heterosexual coitus. And second, because heterosexual relationships have always been closely linked to religions, and for most of them, it was important to guarantee the fertility of human beings. On the other hand, all mythologies strengthen that idea by offering a large variety of metaphors about the polarization of sexes. In that sense, we can see here what some experts call ritualized behavior built on polar role definition. However, in our times, heterosexuality is no longer the only rule to be followed but an option among many others, which means that even the idea of normality has changed. A heterosexual relationship goes beyond the coitus—something excluded from the perspectives on the topic in the 19th century—and it also involves an emotional context where pleasure, desire, the consent in terms of giving and receiving emotions, and so forth, are expressed. Currently, sexuality and reproduction have been decoupled. In many ancient cultures, such as in Greece, heterosexuality was mandatory only to secure procreation, but the field of pleasure and emotions was reserved for homosexual intimacy. SEE ALSO: Bisexual; Homosexual; Lesbian. BIBLIOGRAPHY. Chrys Ingraham, ed., Thinking Straight:
The Power, the Promise and the Paradox of Heterosexuality (Taylor & Francis, 2004); Anita L. Nelson and Jo Ann Woodward, eds., Sexually Transmitted Diseases: A Practical Guide for Primary Care (Current Clinical Practice) (Humana Press, 2007). Natalia Fernandez Diaz Independent Scholar
Heterozygote An individual is heterozygous at a given locus if he has different alleles on both homologous chromosomes within the 22 autosomal chromosomes or the paired sex chromosomes of a female (males, with two differ-
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ent sex chromosomes, are classified as hemizygous at the sex chromosome). Heterozygosity is determined on a locus-by-locus basis and is not used to characterize a whole genome or individual. In terms of human disease, when the wildtype phenotype is determined by a dominant allele, heterozygotes show the wildtype phenotype and disease states are characterized by the loss of heterozygosity. When the wildtype allele is recessive, heterozygotes with one disease causing allele show the diseased phenotype. There are many physiological functions that do not require wildtype gene products to be expressed from both alleles for normal functioning. In such cases, heterozygosity at the given locus is correlated to wildtype phenotype. Disease states that alter these functions must therefore feature the loss of heterozygosity. Such inheritance is typically termed recessive inheritance. A classic example of autosomal recessive inheritance is cystic fibrosis. The wildtype allele codes for the CFTR protein that regulates ion transport and helps maintain body fluids. Although most people without cystic fibrosis have two wildtype alleles, only one is needed to prevent cystic fibrosis. Cystic fibrosis develops when both alleles are mutated. If each allele was subject to a different mutation, the subject is termed a compound heterozygote at the locus, otherwise the subject is deemed homozygous for a disease-causing allele. In practice, compound heterozygotes are often (erroneously) referred to as homozygous recessive so long as each of their mutations is associated with the same disease state. Certain physiological functions require two functional alleles of a given gene. In such cases, heterozygotes produce a decreased level of wildtype protein synthesis in addition to potentially producing some disease associated proteins. Such inheritance is typically termed dominant inheritance. A classic example of such a disease state is Huntington’s disease. Briefly, a mutation of the Huntington gene produces an extended form of the mutant Huntington protein which causes cell death in selective areas of the brain. In this disease state, acquisition of heterozygous genotype is the key: individuals homozygous for the mutant allele are no worse off than individuals heterozygous at the locus. SEE ALSO: Allele; Hemizygous; Homozygote.
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High Blood Pressure
Bibliography. R.L. Nussbaum, et al., Thompson &
Thompson: Genetics in Medicine, 6th ed., revised reprint (Saunders, 2004).
Bimal P. Chaudhari Boston University
High Blood Pressure High blood pressure or hypertension is an increase in the lateral pressure exerted on the walls of the arteries above normal level (ideally 120/80 mm Hg). There is no rigidly defined threshold level of blood pressure which defines risk from safety and the standards vary with age, sex, geographical distribution, height, weight, diet especially sodium intake, hormonal factors, and so forth. Regardless, the current international standards is set on a diastolic pressure greater than or equal to 90 mm Hg or a systolic pressure of greater than or equal to 140 mm Hg is considered to constitute high blood pressure or more aptly hypertension. Systolic blood pressure is the recording taken when the heart is in a state of contraction, while diastolic blood pressure is taken when the heart is relaxed. Screening programs reveal that 800 million individuals worldwide are affected by hypertension, constituting about 25 percent of general population. The prevalence and vulnerability to complications increases with age. For obscure reasons, the incidence is high in African Americans. It accounts for 20 to 50 percent of all deaths. Epidemiological data reveal that systolic blood pressure is more important than diastolic blood pressure as a risk factor for cardiovascular diseases, except for young patients. Hypertension is one of the chronic diseases that has shown the largest decline in mortality over the past four decades. Although the number of deaths in women exceeds those in men, the rate of fall is similar in both sexes. This fall is attributable to the introduction of effective drugs during the past 15 to 20 years. The cardiovascular system is a very dynamic system facing normal variations in blood pressure during course of the day, variations in emotions, excitement, stress, environment, and so forth because normal blood pressure is the outcome of interplay of many factors. For example, blood pressure is at
its peak early morning just before waking up due to a surge of adrenocorticoid hormone. However, such a variation during time of the day (diurnal variation) is considered essentially normal and not as part of any disease process. Similarly, an anxious examinee might show an exaggerated elevation in blood pressure—so-called “white coat” hypertension. Repeated measurements, made on separate occasions, in a stress-free environment are required for a definitive diagnosis of hypertension. High blood pressure is not only one of the major risk factors for most forms of cardiovascular disease, but it is also a condition with its own risk factors. The World Health Organization (WHO) has reviewed the risk factors for essential hypertension as nonmodifiable and modifiable risk factors. Age, gender, genetic factors, and ethnicity are those risk factors that are beyond human manipulation. However, those contributing entities that can be artfully tailored according to personal requirements are weight, salt intake, and low consumption of saturated fat, alcohol, and oral contraceptives, which are an important cause of increased arterial pressure in females. Use of unrefined foods including more fiber and bran, active lifestyle, avoidance of stress, and improvement of socioeconomic status in monetarily deprived countries are important preventive strategies unanimously devised by researchers and practitioners. Hypertension is a complex, multifactorial disease that has both genetic and environmental determinants. More than 95 percent of people have no known cause for high blood pressure, called essential hypertension. Essential, primary, or benign hypertension is a diag-
Screening programs reveal that 800 million individuals worldwide are affected by hypertension.
nosis of exclusion because it is often familial, and may be precipitated by alcohol abuse and obesity. This type of high pressure does not cause short-term problems, and for it, most course remains asymptomatic and thus undiagnosed. It is compatible with a long life, but later in life, it can cause complications such as myocardial infarction (MI), brain stroke, or others. A minority of people, 5 percent or so, develop accelerated or malignant hypertension having a rapidly rising blood pressure and, if untreated, leads to death in a couple of years. The secondary causes of elevated blood pressure are chronic kidney disease or a constriction of blood supply to the kidneys (renal artery stenosis) and tumors of the adrenal glands which secretes high levels of catecholamines (phaeochromocytoma). Other secondary causes include Cushing’s disease and Conn’s syndrome and coarctation of the aorta. Hypertension is a fairly common health problem and its prevalence increases with age. It often remains silent until late in its course. It has no specific symptoms. More than one-fourth of its victims remain unaware of their hypertension, and it remains poorly controlled in those who are diagnosed. Gentle as it seems at its onset, if untreated it can lead to death or morbidity from heart failure, cerebrovascular accident (brain stroke), or kidney failure. It is a major risk factor for coronary heart disease, involving constriction of the vessels of the heart, impinging on its oxygen and nutrient supply. Clinical assessment of a patient with high blood pressure has four aims: • To identify an underlying cause • To assess the severity of the condition and devise a suitable treatment • To identify end organ damage, that is, involvement of heart, brain, kidneys, and eyes • To assess risk of cardiovascular disease involving the heart and adjoining vessels, in context of other risk factors Because hypertension is correlated with increased morbidity and mortality, it is important to define its causes and to be able to initiate appropriate programs to prevent or manage it. Behavioral and dietary changes are the initial therapeutic strategies. Exercise and active lifestyle have a positive role in long-term prevention of hypertension. The choice of drug treatment is influenced by the presence or absence of complications. Beta-blockers
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and calcium channel blockers (CCBs) are useful in patients with angina (complaints of pain in left side of chest and left arm) because of the dual action of these drugs. Similarly, angiotensin converting enzyme (ACE) inhibitors are especially useful if there is any associated dysfunction of the left ventricle. Intensive research aiming at control of hypertension at individual and community level has already provided valuable results. However, much needs to be learned about the underlying mechanisms culminating in essential hypertension and its devastating complications. Many countries in the world still need to invest in this field and launch nationwide programs for awareness, prevention, management, and treatment of hypertension. SEE ALSO: Heart Attack; Stroke. Bibliography. Vinay Kumar, Abul K. Abbas, and Nelson
Fausto, Robbins and Cotran Pathologic Basis of Disease,, 7th ed., (Saunders, 2004); J.E. Park, Textbook of Preventive and Social Medicine (M/S Banarsidas Bhanot, 1986); Nicholas Boon, Davidson’s Textbook of Medicine (Churchill Livingstone, 2006).
Sidrah Farooq Independent Scholar
High-Risk Pregnancy High-risk pregnancy is defined as one in which there is a possibility that the mother, fetus, or newborn could be at risk of serious illness or even death prior to, during, or after delivery. There are many preexisting and coexisting factors that may contribute to this increased risk including those relating to the health of the mother, obstetric abnormalities, and fetal illness. These risk factors can be identified early during pregnancy and given appropriate consideration by a prenatal care provider. Some complex conditions may require the involvement of a specialist in maternal and child health, geneticist, or pediatrician, anesthesiologist, or other medical specialist in the medical evaluation, counseling, and care of the expecting mother. Leading causes of maternal mortality include thromboembolic disease, hypertensive disease, hemorrhage, infection,
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There are many preexisting and coexisting factors that may contribute to a high-risk pregnancy.
and ectopic pregnancy. Infant mortality is defined as death from birth to 1 year of age and includes as causes congenital malformations and conditions related to premature birth. Appropriate and timely prenatal care is essential in ensuring the best possible outcome for both mother and infant. Diagnostic Criteria and Assessment Women who are high risk can be identified as such during an early prenatal care evaluation to assess the health status of both mother and fetus, to estimate the latter’s gestational age, and to outline a plan for continued prenatal care. Prenatal care should include a thorough medical history to identify specific risk factors, a complete physical examination, routing laboratory screenings for common disorders, and followup maternal and fetal assessments over the course of the pregnancy to attempt to minimize risk. Epidemiology and Risk Factors Preterm labor is the leading cause of perinatal morbidity and infant (neonatal) mortality. Risk factors for preterm labor include younger or older maternal age (below 16 or over 35 years); low socioeconomic status; poor maternal nutrition; low
maternal weight (below 110 lb); uterine, placental, or cervical abnormalities; smoking; substance abuse; infection; anemia; multiple gestation (being pregnant with more than one baby); and previous complications in pregnancy. Other preexisting health conditions such as gestational diabetes, heart disease, cancer, sexually transmitted diseases, chronic hypertension, or human immunodeficiency virus (HIV) may cause a high-risk pregnancy. Gestational diabetes occurs exclusively in pregnant women and occurs in about five percent of all pregnancies in the United States. Although most women are able to control their diabetes through a careful regimen of diet, exercise, and monitored weight and blood sugar and give birth to healthy babies, untreated gestational diabetes can result in jaundice, hypoglycemia, mineral deficiencies, or respiratory distress in the infant. Preeclampsia is a condition that causes hypertension and proteinuria (large amounts of protein being secreted in the urine) and occurs in about seven percent of pregnant women in the United States. Preeclampsia typically occurs midway through pregnancy and may be accompanied by swelling in the face and hands, abdominal pain, headache, and blurred vision. If left untreated, preeclampsia progresses to eclampsia, a more severe condition characterized by seizures that can be fatal. Although there is no cure for preeclampsia, in severe cases, delivery of the fetus is the only resolution. In more mild cases of preeclampsia, home treatment of bedrest and frequent assessment by a care provider may be recommended. Prevention Strategies: Preconception and Prenatal Care There is increasing attention to care given in family planning and gynecology centers, as these settings provide an opportunity to address issues of importance to a potential pregnancy, such as existing medical problems, social habits (e.g., alcohol or substance abuse, diet, and exercise), or genetic issues. Additionally, preconception care includes a recommendation of folic acid to prevent against neural tube defects in the developing fetus and control of existing medical problems in the mother such as diabetes. The initial prenatal visit is ripe with opportunity to screen for many of the risk factors that can cause preterm labor or additional complications during
Hip Disorders and Injuries
pregnancy. It is recommended that the first prenatal visit take place in the first trimester or pregnancy and that information on maternal health, particularly past medical and obstetric history, is noted. Some diseases and disorders that could complicate pregnancy are chronic hypertension, heart disease, diabetes, cancer, genetic diseases such as sickle cell anemia, pulmonary disorders, cancer, substance abuse, epilepsy, anemia, pelvic injury, and psychiatric disorders, particularly eating disorders. Women who suffer from anorexia nervosa or bulimia nervosa are significantly more likely to suffer miscarriages and to have infants with lower birth weights than those in the general population. Screening for domestic violence during the prenatal visit is recommended. With the possible exception of preeclampsia, domestic violence is more prevalent than any other significant medical condition screened for during prenatal visits. SEE ALSO: Eating Disorders; Postpartum Depression; Pre-
eclampsia; Pregnancy; Pregnancy and Substance Abuse; Premature Babies; Prenatal Care.
Bibliography. American Academy of Pediatrics and
the American College of Obstetrics and Gynecologists, Guidelines to Perinatal Care, 5th ed. (American Academy of Pediatrics, 2002); N. Micali, E. Simonoff, and J. Treasure, “Risk of Major Adverse Perinatal Outcomes in Women with Eating Disorders,” British Journal of Psychiatry (v.190, 2007); S.H. Mehta, et al., eds., Current Diagnosis & Treatment Obstetrics & Gynecology, 10th ed. (McGrawHill, 2007); Medline Plus, National Institutes of Health and National Library of Medicine, “High Risk Pregnancy,” www.nlm.nih.gov/medlineplus/highriskpregnancy.html (cited April 2007). Lareina Nadine La Flair, M.P.H. Harvard Medical School
Hip Disorders and Injuries The hip is a complex joint formed by the articulation of several bones surrounded by muscular attachments and ligaments to form what is known as a ball and socket joint. The complexity provides for tremendous
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strength but lends to disease susceptibility especially in the event of mechanical stress that may result in debilitating injury. Given the musculoskeletal and supporting structural relations any assortment of disorders is possible. In general, the most common disorders plaguing the hip joint can be classified and further differentiated based on the age of onset, supporting tissue origin of the disorder, bony fracture involvement, and/ or the arthritic components of the ailment. Discussion of the basic principles, functional terminology and anatomical relations will provide the foundation for the overview to follow. The hip forms the essential connection between the lower limb and the bony structures of the pelvic girdle. The hip represents a ball and socket joint, providing a strong and stable foundation, which allows movement to occur in a number of axes. With the femoral head representing the ball and the acetabulum the socket, the round head of the femur articulates with the cup like acetabulum of the hipbone. Most of the head of the femur is covered with articlar cartilage, which is thickest over weight bearing areas. The acetabulum, a semicircular depression in the lateral portion of the hipbone is formed by the fusion of three bony contributions, the ileum, ischium and pubis. The hip is designed for stability over a wide range of movements essential for daily function and ambulation. Functional necessity is evidenced by the fact that during a standing position the entire weight of the upper body is transmitted through the hipbones down into the head and neck of the communicating femurs. Injury and disorders account for extreme impairment in functioning. Injuries and Disorders in Children Congenital dislocation of the hip, also referred to as developmental dysplasia, is an ancient term for a disorder of the hip that has been recognized for several hundred years. The disorder may manifest itself on the day of birth or may follow a more insidious course through the first few years of life. The exact cause is unknown but it is believed that some children may be born with a shallow acetabulum. This may provide a predisposed period in which unusual positioning or a short period of ligamentous laxity may result in a hip joint that will demonstrate insecurity. Diagnosis is often made by physical exam alone. The examination finding is revealed with the Ortolani maneuver. The examiner’s thumb is placed
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over the patient’s inner thigh, and the index finger is gently placed over the outer thigh. The hip is rotated externally, and gentle pressure is placed over the outer thigh. The examiner will feel a “clunk” when the femoral head is rotated in and out of the acetabulum. In the absence of physical exam findings an X ray will not suffice as an additional diagnostic tool based on the lack of bony calcification at this point in skeletal maturation, a sonogram may be required to confirm a suspected diagnosis.Permanent disability will result without treatment. Treatment is initiated with braced abduction with a harness or in a less sophisticated environment the wearing of “double diapers” can be worn for six months to keep the legs abducted. Should conservative measures fail, surgery may need to be considered as an option based on the patient’s age and prior treatment attempts. Children in the age range of approximately four to 12 years of age are susceptible to Legg-Calve-Perthes disease, the name which is given to the idiopathic osteonecrosis of the capital femoral epiphysial head, possibly resulting from an interruption in the blood supply to the developing bone. One in 1,200 children will be plagued by such a disorder with the first signs being that of hip or groin pain. The child is likely to walk with a limp and a decreased hip range of motion may be noted on physical examination. Knee pain on the same side as the effected hip is likely to be present as well. Knee pain in a child must be considered as a potential indicator of a hip injury/disorder, as pain from the hip is referred to the knee and communicated as pain in the region. Standard radiographic studies can be diagnostic in such a disorder. Physical examination findings may consist of the Roll Test: with patient lying in on their back, the examiner rolls the hip of the affected extremity into external and internal rotation. This test should invoke involuntary contraction, guarding or spasm, especially with internal rotation. Treatment is controversial, but generally the goal of treatment is to avoid severe degenerative arthritis. Slipped capital femoral epiphysis is the most common hip abnormality presenting in adolescence. In addition the disorder represents a principal cause of early osteoarthritis. Stress around the hip results in a force of a shearing nature to be applied at the maturing and actively growing region of the femur. Trauma plays a role in the appearance of the fracture, but an
inherent weakness of the immature cartilage also is present. Early treatment leads to better outcome. Unfortunately, slipped capital femoral epiphysis is frequently misdiagnosed, as this disorder has symptoms that can be confusing. Clinical presentation is often misleading, with only 50 percent of patients presenting with hip pain and 25 percent presenting with knee pain. The inconsistency of symptom presentation results in frequent delays in diagnosis. The incidence is one per 100,000 people. Slipped capital femoral epiphysis occurs most commonly in adolescents, with a slightly greater incidence in males than in females. The disorder typically manifests just after the onset of puberty, frequently in overweight children. Diagnosis is made using anteroposterior (AP) pelvis and lateral frog-leg radiographs. The treatment includes stabilization of the hip. Fixation of the joint may be completed with the use of pins, screws, or wires crossing the immature region of cartilage and stabilizing the joint, with the ultimate goal of avoiding further damage to the penetrating vessels by stabilizing the fracture. Osteoarthritis of the Hip A common articular complication is that of arthritis derived from either an osteopathic or rheumatologic origin. Osteoarthritis, commonly referred to as degenerative joint disease, is one of the most common causes of disability in the developed world. Individuals younger than 55 years of age have an equal distribution of effected joints regardless of gender; in older individuals, hip osteoarthritis is more common in men. Racial differences exist in the incidence of hip osteoarthritis as well with a greater incidence in whites as compared to the Chinese of Hong Kong, for example. The principal pathological feature of osteoarthritis is the progressive erosion articular cartilage. The cartilage will then become soft, frayed, and progressively thinned. Eventually the exposed bone (subchondral) will convert to a more dense substance with a smooth surface, a process known as eburnation. Simultaneously there will be bony protuberant outgrowths known as osteophytes from the bone margins ultimately leading to pain and loss of function as a result. Osteoarthritis mainly affects weight-bearing joints, and is more common in overweight and older persons. Whilst the most prominent of the changes take place in the load-bearing areas of the cartilage,
smaller joints may be affected that may not have served as predominant load absorbing joints. Despite the fact that these alterations take place at a macroscopic level, the disorder involves not only the cartilage, but involvement of the entire synovial joint is observed, in which all of the surrounding (synovium) and supporting tissues (ligaments) are affected. The joint pain of osteoarthritis of the hip is described as a deep aching sensation present in the involved joint. Generally, movement of the involved hip joint provokes the pain and rest will usually relieve the pain. With progression of the disease the pain may become persistent. Such advanced disease may be responsible for nocturnal pain and sleep interference, particularly in advanced osteoarthritis of the hip. Rheumatoid Arthritis of the Hip Rheumatoid arthritis is a systemic disease of unknown origin. The disease is more prevalent in women and predominantly affects connective tissue; arthritis is the dominant clinical manifestation. This form of arthritis frequently involves many joints. Arthritis of the hip is likely to be present with multiple joint involvements, especially those of the hands and feet. The pathology of rheumatoid arthritis varies from that of osteoarthritis with the former representing an inflammatory process and the latter representing a non-inflammatory condition. In addition, osteoarthritis created a thinning of connective articular membranes where rheumatoid arthritis will be accompanied by thickening of articular soft tissue, with extension of synovial tissue over articular cartilages, which become eroded; the course is variable but often is chronic and progressive, leading to deformities and disability. Bursitis The bursa, a closed sac or envelope lined with synovial membrane and containing fluid becomes irritated and inflamed. Bursae as functional units are usually found or formed in areas subject to friction. These fluid-filled sacs that functions as a gliding surface to reduce friction between tissues of the hip joint. There are two major bursa of the hip, both of which can be associated with stiffness and pain around the hip joint. Bursitis of the hip refers to the inflammation of the bursa. Pain will be present with movements at the hip joint usually subsiding while the leg is not placed in such a position so a to flex or extend the hip. Range
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of motion will be limited by pain and muscle strength testing will demonstrate mild weakness. Fracture A common form of nonarticular complication involving the hip joint is that of fracture or trauma to the region. Hip fracture and dislocation constitute a major problem due to the disabling nature of these injuries, largely due to the inability to ambulate without surgical intervention following such an injury. Hip fractures primarily occur in the elderly. While relatively few in number, requiring predisposing conditions and significant trauma to provide adequate stress, hip fractures account for millions of hospital days. In addition prompt intervention is required to avoid the frequent complication of death in the elderly following hip fracture (20 to 30 percent of elderly patients in the first year after fracture). Any component of the hip joint may suffer fracture when placed under adequate stress as a result of a trauma or accidental fall. Commonly the integrity of the bony structures may be compromised due to an underlying arthritic condition such as osteoarthritis that may predispose to fracture under normally sustainable forces. Of the bony structures that articulate to form the hip, the femoral neck may fracture most commonly in individuals older than fifty. While these fractures are usually treated surgically with no complications, the unique blood supply to the region leaves the individual at a high risk for avascular necrosis of the femoral head. Complication of Fracture, Avascular Necrosis Avascular necrosis may result following fracture of the femoral neck. The potential disruption of the circulation following fracture is high. If such a compromise should occur the femoral head would be forced to rely on a secondary and possibly compromised circulatory supply. Secondary avascular necrosis of all or a portion of the femoral head may result from the disrupted supply of nutrient and inadequate removal of metabolic waste. Avascular necrosis is not unique to fracture as a complication. Any disorder or injury of adequate severity to interrupt blood supply may result in such a complication. Dislocation The potential for dislocation of the hip joint is highest as a result of trauma and may occur with
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or without fracture. Unless there is preexisting disease in the joint region complete dislocation of the femoral head from the acetabulum (a cup-shaped depression on the external surface of the hip bone, with which the head of the femur articulates) is extremely difficult outside of a high-energy trauma situation. Complications include avascular necrosis with the disruption of arterial supply to the region as well as infection with the compromised supply of immune defenses. Confounding factors include the duration and severity of dislocation and the incidence of complication increases linearly with the interval of dislocation.
Clinical experience has lead to the realization that a group of medications known as diseasemodifying antirheumatic drugs (DMARD) have the capacity to alter the course of rheumatoid arthritis. These drugs are to be started as soon as a diagnosis of rheumatoid arthritis is established, especially in those with evidence suggestive of aggressive disease with a poor prognosis. Immunosuppressive therapy plays a role in pharmacologic therapy as well and in the management of severely damaged joints total joint replacements can be done with the highest success occurring in the replacement of hips, knees, and shoulders.
Treatment of Articular versus Non-articular Injuries and Disorders Articular complications such as osteoarthritis are aimed at maintaining mobility reducing pain and minimizing disability in the effected individual. The intensity of the therapy will be guided by the severity of the condition in the individual patient. For example an individual with mild disease may only require occasional analgesic. For advanced disease, particularly of the hip, the required treatment will consist of an assortment of nonpharmacologic measures to be supplemented by analgesic and or nonsteroidal antiinflammatory therapy. For example, the application of heat to an osteoarthritic joint may reduce pain and stiffness. Most importantly participation in conditioning and exercise programs can be done safely to improve fitness and health without increasing joint pain or the need for analgesic medications. Rheumatoid arthritis creates an incredibly complicated treatment challenge given that the pathophysiology is not completely delineated. Any treatment guidelines further than basic principles are beyond the scope of this selection. The basic goals of therapy include the reduction in inflammation, relief of pain, and the maintenance of function. Treatment is directed at suppressing the inflammatory and immunologic processes that underlie the pathology of the disorder. Improving symptoms and slowing the progressive damage to the surrounding articular structures hopefully follow a conservative approach. Basic pharmacologic therapy initially includes the use of nonsteroidal antiinflammatory medication, except aspirin.
Surgical Intervention Surgical treatment for joint disorders is a region where therapies overlap in the distinction of articular and nonarticular disorders. Surgery plays a role in the management of severely damaged joints, with the goal of pain relief and a reduction in disability. Hip arthroplasty may be indicated in the event of progressive disease leading to incapacitating arthritis (osteogenic or rheumatologic), limiting movement, hindering activities of daily living and requiring pain medication stronger than aspirin. Surgical intervention may be required in the nonarticular hip disorders based on individual circumstances and confounding factors. A femoral neck fracture in an individual in which avascular necrosis is highly likely, in an elderly patient for example, surgery may be warranted as a means of treatment. A hip joint that has suffered preexisting disease and then encounters dislocation may require total arthroplasty. SEE ALSO: Arthritis; Fractures; Surgery. Bibliography. Brent Adler, “Slipped Capital Femoral
Epiphysis,” www.emedicine.com (cited July 2004); D. L. Kasper, et al., Harrison’s Principles of Internal Medicine, 16th ed., (McGraw-Hill, 2005); Keith L. Moorse and Arthur F. Dailey, Clinically Oriented Anatomy, 5th ed. (Lippincott Williams and Wilkins, 2006); Robert A. Novelline, Squires Fundamentals of Radiology, 6th ed. (Harvard University Press, 2004). Donald W. Hohman Jr. St. George’s University
Hispanic American Health In the past two decades, epidemiological research has examined the so-called Hispanic paradox, wherein the Hispanic American population displays a level of population health above what would be expected, given its socioeconomically disadvantaged position. A Hispanic American advantage has been observed using mortality and morbidity data, and a number of plausible hypotheses are being tested in the epidemiological and medical sociological literatures. These hypotheses include the “healthy immigrant” hypothesis and the “salmon bias” hypothesis. While a consensus has not emerged about these hypotheses, research on Hispanic American health has the potential to contribute to the literature on health inequalities and the social determinants of health. More specifically, research on Hispanic American health may highlight the importance of contextual factors (e.g., the quality of community ties, including levels of social capital and social cohesion) and, importantly, may identify pathways through which the health effects of relative socioeconomic deprivation may be alleviated. Explaining the Hispanic Paradox The causes of the paradox are poorly understood, but a number of viable hypotheses have been developed in the literature. These include the “healthy immigrant” hypothesis wherein Hispanic Americans display a health advantage because of disproportionate migration by people with good health in comparison to those in poor health. In this scenario, the observed health advantage is a statistical artifact resulting from self-selection. Additionally, researchers have sought to test the “salmon bias” hypothesis, wherein the health advantage displayed at the population level by Hispanic Americans is a result of less healthy Hispanics returning to their original home countries, thereby lowering the mortality rate of those remaining. Another explanation of the Hispanic paradox suggests that the observed patterns of population health are the result of data artifacts, or data problems including issues with ethnic identification in social surveys and official records. Explanations of the health advantage enjoyed by Hispanic Americans have also incorporated insights from the study of the social determinants of health, including the concepts of social capital/social cohesion and acculturation. Indeed, the Hispanic paradox
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offers important research grounds on which to investigate social and cultural factors which may influence levels of population health, including the concept of social capital. This is a debated topic within social science, but in health research, it has typically been defined as the quality of social networks and/or community levels of reciprocity and trust. It is plausible that the Hispanic paradox is at least partly attributable to high levels of social capital in communities with a high percentage of Hispanic residents; such communities may generate higher levels of social support, encourage health-enhancing community interaction, and compensate for health risks associated with relative material deprivation. Studies examining acculturation have involved time-series or longitudinal analysis of how the Hispanic paradox may change over time in the United States. It is likely that myriad factors underlie the Hispanic paradox, and the healthy immigrant and salmon bias hypotheses are not necessarily contradictory; they may both be true, though perhaps stronger for some groups than others. Health Indicators Death rates for Hispanic Americans differ greatly from death rates for African Americans and non-Hispanic white Americans. According to recent analyses published by the National Center for Health Statistics, death rates (per 100,000) were lower for Hispanic Americans than non-Hispanic white Americans for sex and age group except females under age 5 and males aged 15 to 24. The age-adjusted death rate for Hispanic American males was 818.1, while for nonHispanic white American males, it was 1,035.4 and for African American males, it was 1,403.5. For Hispanic American females, the age-adjusted death rate was 546.0, while for non-Hispanic white American females it was 721.5 and for African American females, it was 927.6. Mortality differences in favor of Hispanic Americans have also been reported using data from the U.S. National Longitudinal Mortality Study and the U.S. National Health Interview Survey–Multiple Cause of Death data sets. In an analysis of the U.S. National Health Interview Survey–Multiple Cause of Death data set published by Alberto Palloni and Elizabeth Arias, the difference in mortality amounted to approximately five to eight years of additional life expectancy at age 45 (excluding Puerto Ricans and Cubans, who did not display the paradoxical advan-
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tage). The evidence base for the Hispanic paradox is dominated by mortality data. However, recent results indicate that the paradox may also be observable with measures of stroke, cancer, heart attack, hip fracture, hypertension, and diabetes mellitus. Social Inequalities in Health A large field in social epidemiology and medical sociology has investigated social inequalities in health within the framework of the social determinants of health. The basis of this framework is that health is produced not only by access to medical treatment, but also by the cumulative experience of social conditions over the life course. As such, social conditions may be seen as the fundamental causes of illness, or the “causes of the causes.” A fundamental building block of the social determinants of health model is the social gradient in health, or the patterning of morbidity and mortality by socioeconomic position. Importantly, this gradient does not typically display a threshold effect; that is, health differences run throughout the income spectrum, from the very bottom to the very top. Research on Hispanic American health is important to this tradition because it 1.) represents a paradox, because the health of Hispanic Americans is better than would be expected given the relatively socially disadvantaged position, and 2.) highlights the important role of social and cultural factors as determinants of health. Challenges and Opportunities Relatively few studies of Hispanic American health have been conducted at the national level, despite the growing size of the Hispanic population in the United States. However, over the past few years, a number of studies have been published and the Hispanic paradox has attracted more attention. These studies have highlighted important challenges, including problems of data quality in national health surveys and official records. Ethnic classification is particularly difficult to measure in social surveys and its measurement in official vital statistics is also problematic. Research has also been limited by an overemphasis on the Hispanic population as an aggregated whole, rather than its many diverse groups. Contemporary research on Hispanic American health is attempting to disaggregate the analysis by country of origin, and preliminary results indicate that the paradox may be most detectable among Mexican Americans and not at all pres-
ent for Puerto Ricans and Cubans. This underscores the heterogeneity present in the Hispanic American population and offers an important avenue for future empirical research. Overall, research on Hispanic American health holds the potential to significantly contribute to epidemiological and medical sociological knowledge on the social determinants of health. The apparent paradox wherein the Hispanic population enjoys a higher level of health status than would be predicted given its relatively socioeconomically deprived position lends credence to the importance of social and cultural determinants of health, while at the same time, warns researchers of the dangers associated with an overly reductionist approach to health inequalities that focuses solely on individual-level income. SEE ALSO: African American Health; Asian American
Health.
BIBLIOGRAPHY. Karl Eschobach, et al., “Neighborhood
Context and Mortality among Older Mexican Americans: Is There a Barrio Advantage?” American Journal of Public Health (v.94/10 2004); L. Franzini, J. Ribble, and A. M. Keddie, “Understanding the Hispanic Paradox,” Ethnicity and Disease (v.11, 2001); National Center for Health Statistics, National Vital Statistics Reports (v.51/5, 2003); Alberto Palloni and Elizabeth Arias, “Paradox Lost: Explaining the Hispanic Adult Mortality Advantage,” Demography (v.41/3, 2004). Fernando De Maio, Ph.D. Simon Fraser University
Histology Histology is the study of microscopic anatomy using slides of tissue sections. It is a crucial aspect of determining diagnosis and prognosis for many diseases, as well as an educational tool for understanding the structure of the human body and the mechanisms of disease. When histology is used to study diseased tissue, it is called histopathology. There are many techniques for getting the tissue specimen from the body to the microscope slide. The first step is fixation, whereby the tissue is soaked in a chemical that stops all metabolic processes. The most
commonly used fixative is formalin, which contains formaldehyde and phosphate-buffered saline. The sample is then washed, put in multiple solutions of progressively more concentrated alcohol to remove the water, and washed with an organic solvent to remove the alcohol. The second step is embedding, whereby the specimen is impregnated with melted paraffin wax and set to cool. The washing and embedding process takes at least 12 hours when using standard procedures. The tissue-containing paraffin block is then cut into very thin slices of two to eight micrometers and mounted on slides. In the final step, the slide is stained with a dye so the tissue can be visualized. There are several dyes that are used to highlight different features of the cells. The most commonly used one is hematoxylin and eosin (H&E). Hematoxylin stains the nuclei of cells blue while eosin stains the cytoplasm pink. Other dyes include crystal violet, which stains gram-positive bacteria dark blue, and periodic acid Schiff (PAS), which stains carbohydrates pink. Masson’s trichrome stains keratin red, collagen and bone blue-green, cytoplasm pink, and nuclei black. Silver staining is used to highlight DNA and proteins like type III collagen. To highlight fat, Sudan stain is used. To localize specific proteins or antigens, the tissue is exposed to antigen-specific antibodies conjugated to a fluorescent dye. Alternative techniques of fixation and embedding are sometimes when they are needed. For example, to retain membrane structures for electron microscopy, histologists use fixatives containing heavy metals that bind to phospholipids. Tissue can also be frozen and cut using a cryostat. This technique is called cryosection, and is used when the analysis of a specimen needs to be performed quickly. Cryosection is used during intraoperative consultation, which is when during a surgery, histology is used to look at tissue that has been removed to determine how to proceed. For example, if a cancer is suspected to have spread, a sample of the suspected metastasis (spreading cancer) is given to a pathologist to determine if it is cancer. If so, the surgry is usually not curative, and the surgeon will choose a less aggressive surgery. Another use of histology is to determine the nature of infectious agents, for example whether a bacterial infection is gram-positive or gram-negative will allow the more proper choice of antibiotic. Histological mechanisms are also used to screen for diseases, such
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as the analysis of cervical scrapings collected during a Pap smear to determine if the endothelium is progressing toward cervical cancer. SEE ALSO: Cervical Cancer; Diagnostic Tests. BIBLIOGRAPHY. Abraham Kierszenbaum, Histology and
Cell Biology: An Introduction to Pathology (Elsevier Health Sciences, 2006); Michael H. Ross, Histology: A Text and Atlas (Lippincott Williams & Wilkins, 2003). Laura Janneck Case Western Reserve University School of Medicine
Hodgkin’s Lymphoma Lymphoma is a cancer of the lymphatic system, which is composed of the lymph nodes and other immunological and blood-forming organs. Hodgkin’s lymphoma (HL) is a subtype of lymphoma with unique characteristics. Dr. Thomas Hodgkins, an English physician and pathologist first described this disease in 1832. The National Cancer Institute estimates that there are 78,00 new cases of Hodgkin’s lymphoma per year in the United States and 62,329 new cases in the world each year. It is more common in men than women and more common in whites than in Asians. New cases occur most frequently in young people and individuals older than 50. Patients with Hodgkin’s lymphoma may have a number of signs and symptoms, including enlarged lymph nodes, unexplained weight loss, fever, night sweats, itching, and intermittent fever. On examination, they may have an enlarged spleen or enlarged liver. Less common but also seen are chest pain, cough, shortness of breath, coughing of blood, and nervous system problems. While the cause of this cancer is unknown, the Epstein-Barr virus is thought to have some relationship with the lymphoma. Patients with HIV infection also have a higher incidence of Hodgkin’s lymphoma than the general population. A thorough history, physical examination, and laboratory studies of the blood and imaging techniques may direct a physician toward the diagnosis of Hodgkin’s lymphoma, but the definitive diagnosis must be made with examination of the
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cancer tissue. This may be obtained from a biopsy of a lymph node. All Hodgkin’s lymphoma tissue reveals characteristic Reed-Sternberg cells when the cancer tissue is examined under the microscope. The World Health Organization (WHO) classifies HL into five types based on tissue findings. Sixty to 80 percent of all cases are nodular sclerosing type, 15-30 percent are the mixed-cellularity type, less than one percent are lymphocyte depleted, five percent are lymphocyte rich, and five percent are nodular lymphocyte-predominant type. The nodular sclerosing type is frequently observed in adolescents and young adults. Staging of Hodgkins lymphoma is most commonly done clinically with the Ann Arbor classification. Stage 1 denotes cancer involving a single lymph node area or single extranodal site. Stage 2 is cancer involving two or more lymph node areas on the same side of the diaphragm. Stage 3 denotes lymph node areas on both sides of the diaphragm involved. Stage IV indicates disseminated or multiple involvement of extranodal organs. “A” or “B” designations indicate the absence or presence of B symptoms. B designation signifies the presence of either fever or unexplained loss of more than 10 percent of body weight in the last six months. A designation is the absence of any B symptoms. The stage of HL correlates indirectly with prognosis; in other words, the farther the spread of the disease, the poorer the prognosis. Treatment options for HL include radiation therapy, chemotherapy, and high-dose chemotherapy with transplantation. There are several possible combinations of chemotherapy, but the standard regimen now in use is ABVD (adriamycin, bleomycin, vinblastine, and dacarbazine). Prognosis of patients with HL is dependent on the staging of the cancer. The statistic “five-year survival” indicates the percentage of people who are alive five years after their diagnosis. The five-year survival rate for patients with stage I and II Hodgkins lymphoma is 90 percent, for stage III is 84 percent, and for stage IV is 65 percent. See Also: Cancer (General); Lymphoma; Non-Hodgkin’s
Lymphoma.
Bibliography. A. Jemal, et al., “Cancer Statistics,” CA: A
Cancer Journal for Clinicians (v. 56/2, 2006); T.A. Lister, et al., “Report of a Committee Convened to Discuss the Evaluation and Staging of Patients with Hodgkin’s Disease:
Cotswolds Meeting,” Journal of Clinical Oncology (v.8, 1990); SEER: “Surveillance Epidemiology and End Results Cancer Statistics Review, 1975–2002,” http://seer.cancer. gov/ (cited July 2007). Rachana Potru Michigan State University College of Human Medicine
Homeopathy Homeopathy is a system of therapeutic thought based on the concept that “like cures like.” It was developed at the end of the 18th century by the German physician Samuel Hahnemann. Using as evidence the effect of quinine on himself that it produced symptoms that resembled those of malaria, he developed the concept of the “law of similars.” This law supposes that diseases should be treated by drugs that produce in healthy people the types of symptoms of the disease which it is hoped to be remedied. Homeopathy was welcomed at the time as a positive and innovative manner of thinking and to be preferred to other methods such as bleeding and purging which were then still widespread. However, in the 20th century and beyond, homeopathy began to be treated with some disdain by scientists because it did not cohere with the methods then being developed and extended. Modern homeopaths are likely to concentrate on the correct identification of the disease to be treated on which considerable care is likely to be spent. For many symptoms or combinations of symptoms, many possible diseases or causes might be responsible. The homeopath is likely to rely on self-description by patients and personal experience to identify the correct cause and hence to select the appropriate cure. There is also the issue of identifying a suitable remedy for each disease or problem. Thousands of these exist, but most have become part of the homeopathic canon either through reliance on previous wisdom or on personal experience and experimentation. The large-scale resources available in many cases to develop new pharmaceuticals have not been available to homeopaths generally speaking and documentation of the efficacy of treatment and possibility of side effects is also lacking. In the absence of rigorous quality-control standards which are trans-
Homicide
parent and enforceable by state law agencies, there is also the potential problem of inconsistency of supply and variability in potency of drug used. Once the homeopath has determined the nature of the medical cause of symptoms and determined, therefore, an appropriate treatment, it is necessary to dilute the treatment in a much larger volume of water. One drug alone is used and the dilution may be more than one part of effective agent to one trillion parts of water. According to scientific theory, such a low level of active agent can have no possible impact upon any cure that might subsequently eventuate. Nevertheless, homeopathy continues to have many adherents and it strikes a chord with many people who believe that the nature of the modern developed world relies too much upon artificial or unnatural substances and that chemical pharmaceuticals are inherently undesirable. Medical research has not found compelling evidence for the efficacy of homeopathy but it has not dismissed it completely either. There are cases in which people suffering from hay fever or some kinds of asthma and flu have obtained relief from homeopathic remedies. However, distinguishing between positive results from homeopathy and those arising from placebo effects has also not yet been fully achieved. On a realistic note, homeopathic remedies are not likely to do any actual harm because the patient will almost certainly be drinking nothing other than plain water. A number of homeopathy clinics are supported by the National Health Service in the United Kingdom and have been since 1948, although this has been controversial in some cases. Homeopathic treatments are dispensed in these cases by qualified medical practitioners and they and their patients may choose to use homeopathy more or less at their discretion. Non-medically qualified homeopaths also exist and are obliged to be registered with the appropriate society before they can legally offer consultation. Homeopathy is particularly popular in India, where the ayurvedic tradition has a number of similarities with its approach, as well as in some European countries. It is much less popular in the United States and its popularity continues to decline. SEE ALSO: Alternative Medicine; Herbal Medicine. Bibliography. D. Edward, The American Institute of Ho-
meopathy Handbook for Parents: A Guide to Healthy Treat-
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ment for Everything from Colds and Allergies to ADHD, Obesity, and Depression (Jossey-Bass, 2005); Eliza O’Driscoll, “With Complements,” Occupational Health (v.56/11, 2004). John Walsh Shinawatra University
Homicide The term homicide refers to the act of killing another human being and comes from the Latin word homo for a human being, and –cide from the Latin caedere meaning “to kill.” The term homicide is used as a criminal offense in the United States, whereas in Britain, the criminal offense is usually referred to as murder, with manslaughter referring to the taking of human life in a manner, at law, less culpable than murder. There are several derivative terms that come from the word homicide, including parricide (killing of one’s parents), patricide (killing of one’s father), matricide (killing of one’s mother), mariticide (killing of one’s spouse), uxorcide (killing of one’s wife), filicide (killing of one’s children), fratricide (killing of one’s brother or a friend in battle), sororicide (killing of one’s sister), infanticide (killing of an infant), regicide (killing of a monarch), genocide (killing of a race), and suicide (killing of oneself ). Although nowadays the laws in most countries are the same regardless of the person killed, throughout history there have been laws governing these, often involving harsher punishments for some types of homicide. For example, in Rome, the offense of parricide resulted in one of the harshest punishments involving flogging and eventually drowning at sea with the culprit sewn, along with a dog and a rooster, into a leather sack symbolizing the womb. However, since medieval times, the punishments for most types of homicides have been the same, except for regicide, for which horrendous punishments were often prescribed. Following the restoration of King Charles II in 1660, the new royal government sought to arrest the “Regicides”—those who had been involved in the trial and execution of the king’s father, King Charles I, in 1649. This resulted in the tracking down of all the judges involved in the trial of Charles I, and their imprisonment or execution, or their murder. Those involved in the
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execution of King Louis XVI of France in 1793 were also known as Regicides although they did not gain the same notoriety as those in Britain. The criminal code generally divides homicidal crimes into three different fields: murder, manslaughter, and criminal homicide. The first includes felony murder and capital murder. Manslaughter includes voluntary manslaughter, involuntary manslaughter, intoxication manslaughter, death by dangerous driving, and reckless manslaughter. Criminal homicide includes culpable homicide in Scottish law, with negligent homicide in some criminal jurisdictions, and criminally negligent homicide. There has regularly been a difficult legal problem concerning suicide. For religious reasons, it is often regarded as a criminal offence, and during the Middle Ages and early modern Europe, attempted suicide was often regarded as attempted murder. There has also been a complicated legal area concerning assisting someone else committing suicide, with it being regarded as a criminal offense in most parts of the world. There have been many books on the topic of homicide, with a number concentrating on the forensic or medical aspects of the various cases, some providing psychological information on the people concerned, and others dealing with the cases from a legal angle. SEE ALSO: Suicide. Bibliography. Robert Asher, Lawrence B. Goodheart,
and Alan Rogers, eds., Murder on Trial: 1620–2002 (State University of New York Press, 2005); Bruce L. Danto, John Bruhns, and Austin H. Kutscher, eds., The Human Side of Homicide (Columbia University Press, 1982); Terance D. Miethe and Wendy C. Regoeczi, with Kriss A. Drass, Rethinking Homicide: Exploring the Structure and Process Underlying Deadly Situations (Cambridge University Press, 2004); Gini Graham Scott, Homicide by the Rich and Famous: A Century of Prominent Killers (Praeger, 2005). Justin Corfield Geelong Grammar School, Australia
Homosexuality The term homosexual was coined in the 19th century by combining the Greek prefix homo-, meaning
same, and the Latin root sex-, meaning sex or gender; it first appeared in print in a 1869 German pamphlet published anonymously by the journalist and social reformer Karl-Maria Kertbeny (1824–82). However, sexual relationships between members of the same sex have existed since ancient times in many different cultures and societies. It is difficult to make general statements about the prevalence of homosexual relationships or about people who engage in such relationships because of the differing ways intimate relationships are perceived and discussed in different cultures and historical periods, and because such behavior may remain covert because it is taboo within a particular society. Defining and measuring homosexuality The term homosexual is both a noun and an adjective: one may refer to an individual as a homosexual, or refer to homosexual behavior or homosexual activity. In practice the terms gay for men and lesbian for women are often used instead, along with other terms such as queer, while the term straight is often used interchangeably with heterosexual. Defining a sexual act as heterosexual or homosexual is fairly simple in most cases, because it depends on the biological sex of the individuals involved (although there are complicating factors such as how to classify transgender and hermaphroditic individuals). However, defining what constitutes a sexual act is less simple, particularly when one considers cases such as the “romantic friendships” common among women in 19th-century America. It is much more problematic to attempt to classify individuals into single categories of sexual behavior or preference, for instance, by asking respondents to a survey to check one box describing themselves from among “homosexual,” “heterosexual,” or “bisexual.” While some individuals live their entire lives having had sexual desire for, and sexual relations with, members of one sex, many others have a more varied experience, and behavior, desire, and identification may not coincide. For this reason, any discussion of homosexuality must include an acknowledgment of definition and measurement issues. The modern, scientific study of sexuality began in Germany in the mid-19th century, and two differing conceptions of homosexuality were presented from the beginning. Karl Heinrich Ulrichs (1825–95) believed in the discrete categorization of human sexuality, and
conceived of homosexuals as constituting a “third sex” alongside heterosexual males and heterosexual females. In contrast, Magnus Hirschfeld (1868–1935) developed a theory of “intermediate steps” which posited that every person was a unique combination of male and female characteristics. Alfred Kinsey (1824–1956), the pioneering American sex researcher, agreed with Hirschfeld that people could be a mix of homosexual and heterosexual proclivities, and classified them on a seven-point scale from 0 (exclusively heterosexual) to six (exclusively homosexual). There are four major approaches to measuring and classifying homosexuality are evident in contemporary surveys: 1. focusing on identity or sexual orientation, for instance, asking people if they consider themselves to be gay, straight, or bisexual; 2. focusing on sexual behavior, for instance, asking people if in the last 12 months they have had sexual contact with men, women, both, or neither; 3. focusing on sexual attraction, for instance, asking people if they are exclusively or primarily attracted to males, females, both, or neither; 4. focusing on how they are perceived by others, for instance, asking if people have been harassed or threatened because they were perceived to be lesbian, gay, or bisexual. Of course the approach used, and the period of time involved, will make a difference in the number of people classified as homosexual: for instance, more people have engaged in homosexual behavior over their lifetime than have had such experiences in the previous year. Smith presents a summary of a number of surveys of sexual behavior in the United States: he found that no contemporary survey has come close to Kinsey’s estimate that 10 percent of the adult United States population is homosexual, and that typically two to three percent of sexually active men and one to two percent of sexually active women are classified as currently homosexual. Homosexuality and Health Because of the measurement issues discussed above, and the fact that questions about sexual preference or sexual behavior have not consistently been included
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in major U.S. health surveys, it is difficult to make definitive statements about the health of homosexuals or their specific health needs. However, several general statements can be made. It is true that some health risks, including those related to sexual practices, differ for homosexuals: for instance, gay men are at higher risk for contracting many sexually transmitted diseases, including HIV/AIDS, than lesbians or most heterosexuals. In fact, AIDS was originally called Gay-Related Immune Deficiency or GRID, because the first U.S. cases were identified in gay men. Balancing this point is the fact that gay men and lesbians have most of the same health risks and needs as do straight men and women, a fact which may be obscured if discussion of gay and lesbian health focuses exclusively on sexually transmitted diseases. This is a particularly important consideration because, due to discrimination, alienation or lack of understanding of their health needs, gay men and women do not always receive the routine screening and preventive health services recommended for all men and women. For instance, the report issued by the Institute of Medicine’s Committee of Lesbian Health Research Priorities in 1999 found that lesbians were less likely to receive Pap smears than heterosexual women, although they have equal need for this screening procedure. A third consideration is that the lack of legal recognition of gay partnerships on an equal basis with marriage affects gay and lesbian access to healthcare, because while many married people receive their health insurance through their spouse’s employer, gay and lesbian partners do not have this option. A final point is that gay men and lesbians have been found to have higher rates of psychiatric disorders and of health risk behaviors such as alcohol and substance abuse and smoking, and the risk of suicide attempts among gay and lesbian youth has been found to be much higher than among heterosexual youth. These results are usually attributed to stress caused by antigay discrimination. SEE ALSO: Lesbian; Sexually Transmitted Diseases. Bibliography. L. Faderman, Surpassing the Love of
Men: Romantic Friendship and Love between Women from the Renaissance to the Present (Morrow, 1981); GayData, www.gaydata.org (cited October 25, 2006); J.E. Heck, R.L. Sell, S.S. Gorin, “Health Care Access among Individuals
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Involved in Same-Sex Relationships,” American Journal of Public Health (v.96/6, 2006); A.C. Kinsey, W. B. Pomeroy, and C.E. Martin, Sexual Behavior in the Human Male (Saunders, 1948); A.C. Kinsey, et al., Sexual Behavior in the Human Female, (Saunders, 1953); T.G.M. Sandfort, et al., “Same-Sex Sexual Behavior and Psychiatric Disorders: Findings from the Netherlands Mental Health Survey and Incidence Study (NEMESIS),” Archives of General Psychiatry (v.58, 2001); T. W. Smith, American Sexual Behavior: Trends, Socio-Demographic Differences, and Risk Behavior, GSS Topical Report No. 25 (National Opinion Research Center, 1998); A.L. Solarz, ed., Lesbian Health: Current Assessment and Directions for the Future (Academy Press, 1999). Sarah Boslaugh, Ph.D., M.P.H. BJC HealthCare
Homozygote A homozygote is an individual with two identical alleles at a given locus within the 22 autosomal chromosomes or the paired sex chromosomes of a female (males, with two different sex chromosomes, are classified as hemizygous at the sex chromosome). Homozygosity is determined on a locus-bylocus basis and is not used to characterize a whole genome. In terms of human disease, all diseases of genetic origin (as well as many diseases in which genetic predisposition is a key factor) require or are promoted by a loss of wildtype homozygosity. Further, some diseases and states require the gain of a mutant homozygosity. These two pathways to disease broadly correspond to the concepts of dominant and recessive inheritance of disease, although there are some caveats. Certain physiological functions require two functional alleles of a given gene. In such cases, the loss of homozygosity caused by mutation to either of the alleles leads to a decreased level of wildtype protein synthesis and/or expression of protein coded for by the mutant allele. Such inheritance is typically termed dominant inheritance. A classic example of such a disease state is Huntington’s disease. Briefly, a mutation of the Huntington gene produces an extended form of the mutant Huntington pro-
tein which causes cell death in selective areas of the brain. In this disease state, loss of homozygous wildtype is the key: Individuals homozygous for the mutant allele are no worse off than individuals who have one mutant allele and one wildtype allele. There are many physiological functions that do not require wildtype gene products to be expressed from both alleles for normal functioning. Disease states that alter these functions must, therefore, feature the total loss of wildtype allele expression. Furthermore, certain disease states require not only the loss of wildtype expression, but the expression of two mutant alleles coding for the same protein. In practice, such conditions are exceedingly rare and not currently of clinical significance. These so-called recessive gain of function mutations primarily have been found to affect channels and membrane proteins responsible for signaling pathways. SEE ALSO: Allele; Hemizygous; Heterozygote. Bibliography. H.A. Lester and A. Karschin, “Gain of
Function Mutants: Ion Channels and G Protein-Coupled Receptors,” Annual Review of Neuroscience (v.23, 2000); R. L. Nussbaum, et al., Thompson & Thompson: Genetics in Medicine, 6th ed., revised reprint (Saunders, 2004). Bimal P. Chaudhari Boston University
Honduras Honduras is located in the heart of central America, between Nicaragua, El Salvador, and Guatemala. The country won independence from Spain in 1821 and has managed to stay largely clear of the endless civil wars that have plagued its neighbors, but it has never prospered in its relative freedom, and most of its citizens struggle to stay afloat. The population is 7.3 million (2006 estimate) and is growing at 2.16 percent annually. The birth rate is 28.24 per 1,000 people, the death rate 5.28 per 1,000, and the migration rate is in the negative column, with minus 1.39 migrants per 1,000 people. Hundreds of thousands of Hondurans have left the country in recent years, most traveling north to find work in the
United States. It is simply more profitable. In 2002 alone, these economic immigrants wired home some $700 million in remittances. Honduras is largely covered by mountains, with just a few lowlands along the coast and the river valleys. Between 40 and 50 percent of the population lives in urban areas. Population density is 64 people per square kilometer. Only 9.53 percent of the land is arable, but for many decades, most of the country’s slim Gross Domestic Product has come from agricultural exports such as bananas and coffee and fully one-third of Hondurans work in agribusiness. The national economy was decimated in 1998 in the aftermath of Hurricane Mitch. That devastating storm took the lives of 5,600 Hondurans and caused several billions of dollars in damage. The government has recently opened the door to maquiladoras, foreign-owned factories taking advantage of free-trade arrangements. However, neither agribusiness, mining, nor maquiladoras have done much to improve the lot of most Hondurans. Per capita income is $1,030 a year, and 21 percent of the population gets by on less than $1 a day. The average diet is based on beans, rice, tortillas, plantains, meat, potatoes, and cheese. Rates of malnutrition are high, particularly among the poor. About 90 percent of the people have access to clean water and 68 percent have access to sanitary facilities, but access drops significantly outside the cities. Honduras has the highest rate of parasitic infection in the western hemisphere. Hookworm is common, as are malaria and hepatitis. Life expectancy at birth is 67.75 for men and 70.98 for women, but healthy life expectancy is much lower at 56.3 for men and 60.5 for women. Infant mortality is 25.82 per 1,000 live births. The mortality rate for children between the ages of 1 and 5 years is 41 per 1,000. The average woman has 3.59 children and the maternal mortality rate is 220 deaths per 100,000 live births. Only 56 percent of births are monitored by trained attendants. The HIV/AIDS rate is 1.8 percent, with an estimated 63,000 living with the virus in 2003 and at least 4,100 AIDS-related deaths. This, along with other factors, has contributed to a large population of orphans, with more than 180,000 children under the age of 17 having lost one or both parents. Violent crime is rampant in the cities, with murder, rape, assault, and kidnapping for profit now common. Gang violence has flourished almost unchecked.
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Honduras spends about $41 per capita annually on healthcare. Medical care outside the main cities of Tegucigalpa and San Pedro Sula are sketchy and hard to come by; ambulance service from the outlying regions is rare. The World Health Organization counted 3,676 doctors and 8,333 nurses serving a population of 7.3 million. SEE ALSO: Healthcare, South America. Bibliography. Central Intelligence Agency, “The World
Factbook—Honduras, www.cia.gov (cited June 2007); World Health Organization, Honduras, www.who.int (cited June 2007). Heather K. Michon Independent Scholar
Hormone Replacement Therapy Hormones are a set of chemical substances which exist inside the body and regulate a number of critical life functions. As a result of various changes in bodily condition, the responsible organs may fail to produce sufficient or any hormones and this can result in negative health outcomes. For example, menopause inhibits the production of estrogen and this can result in hot flushes and more serious symptoms. In certain cases, medical practitioners will recommend replacement of the hormone from an external source as a means of treating the undesirable symptoms. The production of hormones has generally resulted from synthesizing cognate hormones from animals and treating them appropriately before introducing them into the patient’s body. However, improvements in scientific and pharmaceutical technology make it possible for entirely artificially created hormones to be used in the future. Hormone replacement therapy (HRT) overall represents a large economic opportunity for pharmaceutical companies to exploit and, consequently, there has been some controversy concerning the motivations for some medical practitioners to prescribe HRT and the incentives they might be receiving to influence their decisions.
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HRT most commonly takes the form of a combination of estrogen and progestin. The purpose of the treatment is generally to reduce the symptoms of postmenopausal health, but the operations of hormones within the body are so complex and multivalent that the reintroduction of hormones can have many different and often unpredictable effects. These may be either positive or negative. Positive side effects can include strengthening of the bones and reduction of the risk of colon cancer. Negative side effects include elevated risks of cardiovascular disease and breast and other types of cancer, stroke, blood clots, and dementia. Some of the promised positive side effects of HRT, which include better self-esteem through enhanced beauty and sex life have not fully materialized. Some research has also shown that postmenopausal symptoms may have been overstated and that those women who do suffer from them may not obtain the level of relief that had been promised. As a result, many doctors now follow the policy that only HRT should only be prescribed when the woman concerned is suffering symptoms of vaginal dryness, hot flushes, or insomnia to such an extent that they significantly affect quality of life. An alternative prescription may also be offered if the risk of osteoporosis is deemed to be sufficient. However, there are many occasions on which the woman is left without a clear direction, because symptoms might be present but bearable, at least periodically, while the risks of the treatment may appear possibly worse. In these cases, the woman may have to bear the responsibility for the decision personally and this might be an onerous burden, especially if the woman feels intimidated by the medical experts and the other aspects of the environment. The revelations of the research findings which occurred over the past few years have proved to be rather disturbing to those who have been receiving HRT or had been considering doing so. Trust in the medical profession has been shaken to some extent and the reputation of the pharmaceutical industry has also been further affected. HRT has become a sociological as well as a medical issue. A number of authors have argued that the process of menopause, for example, is one that is natural and which women are in general terms quite capable of dealing with through their own resources. However, medical practitioners have, so it is argued,
changed the perception of this natural procedure so that it has become regarded as a medical process and an event which requires the intervention of experts and their scientific products. In other words, women are disempowered because their bodies betray them by becoming the scene of an inherent weakness which only outsiders and drugs can manage. Since women’s bodies are so often the battleground for controversy over political and religious debate, this argument has become not just impassioned but powerful as well. After all, it is clear that there are powerful incentives for medical practitioners to prescribe expensive regimes of drugs and medicines and to ensure that all citizens believe themselves to be necessarily patients for much of their lives. Consequently, it may be concluded by some that the treatment of menopause is part of a system aimed at trapping women and their carers in a world of commerce in which they must continually yield their money to maintain good health and subvert the problems their bodies continually cause them. See Also: Hormones; Menopause; Menstruation and
Premenstrual Syndrome.
Bibliography. Amy Allina, and Cynthia Pearson, “The
Great Hormone Hoax,” Multinational Monitor (July/ August, 2002); Elizabeth Barrett-Connor, and Deborah Grady, “Hormone Replacement Therapy, Heart Disease, and Other Considerations,” Annual Review of Public Health, (v.19, 1998); National Women’s Health Network, The Truth about Hormone Replacement Therapy: How to Break Free from the Medical Myths of Menopause (Prima Lifestyles, 2002). John Walsh, Shinawatra University
Hormones The word hormone is derived from a Greek word meaning “to arouse to activity.” Endocrinologists are physicians who specialize in the study of the endocrine system, which generates hormones. This system was first identified by French physician Claude Bernard (1813–78) in the mid-19th century. The
word endocrine is also Greek in origin and means “separated within,” which describes the actions by which hormonal activity is aroused in the cells of origin (autocrine) as well as in the surrounding cells (paracrine). Once hormones are secreted, they enter into the blood stream to perform specific functions, thereby keeping the body in working order as they interact with the brain, heart, liver, kidneys, digestive system, nervous system, immune system, and other parts and systems of the body. As they perform their assigned functions, hormones regulate the rate of chemical reactions in specific cells and influence the way in which substances in the body are transported through cell membranes. Once hormones perform their specific functions, they are eliminated through the kidneys. Hormones also play a major role in growth and development. Malfunctions of growth hormones may lead to either dwarfism or gigantism. During conception, hormones influence the formation of sex organs. After birth, hormone levels decline. During puberty, which generally begins in industrialized nations between the ages of 12 and 14 years, hormone levels rise rapidly. Puberty may be delayed in poorer countries as a result of poor nutrition. If malfunctions occur in the production of sex hormones, individuals may not develop the secondary sex characteristics that lead to male and female characteristics in adulthood. During puberty, females normally start to menstruate as their bodies begin producing eggs in preparation for motherhood. Subsequently, fluctuating hormonal levels may result in pre-menstrual syndrome (PMS), which is associated with a variety of symptoms such as pain, bloating, and wide mood swings. Delayed or absent menstruation or abnormal menstrual pain are indicative of possible problems. Male hormones released during puberty result in the appearance of facial and body hair, deepened voices, elongation of the long bones of limbs, and increased aggression and libido. Male and female hormones during puberty are also responsible for teenage acne and for the infamous moodiness of teenagers. Because hormones exercise some neural controls over emotions, they also determine how humans of all ages deal with stress and emotions such as aggression and fear. The major female hormone, estrogen, and the major male hormone, testosterone, activate the sex drive
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and control fertility, ensuring that the human race will survive through procreation. Once a female becomes pregnant, estrogen and progesterone prepare her body for motherhood. When she reaches the end of her childbearing years, levels of “female” hormones drop, and a woman enters menopause. In one percent of females, premature ovarian failure occurs when a woman under the age of 40 stops producing estrogen and enters menopause. The physical protections that estrogen provides have been well documented, and hormone replacement therapy (HRT) has been widely used to offset the loss of estrogen during and after menopause. However, a number of studies have linked HRT to cancer, particularly breast cancer, and many women have sought alternative methods of dealing with estrogen loss. In males, some studies have revealed a link between high testosterone levels, which may be associated with high dietary fat intake, and prostate cancer. However, the exact causes of such cancers are unknown. There are six major glands of the endocrine system—pituitary, thyroid, parathyroid, pancreas, adrenal, and gonads—as well as a number of minor glands. Each has its own particular function designed to ensure good health. The pituitary gland is considered the leader of the endocrine system. The hypothalamus conducts the hormones secreted by the pituitary gland to target areas. Together, they work with the brain to control other endocrine glands. Hormones are divided into two classes: amino acid and peptide hormones, which are not liquid soluble, and the steroid hormones, which are highly liquid soluble. A hormone imbalance occurs when hormone levels are either too aggressive or deficient, leading to a variety of medical conditions. For instance, insulin is a polypeptide hormone secreted by the pancreas. If the liver does not perform its task of producing insulin in appropriate amounts, a person may become diabetic. This condition is associated with a number of other disorders such as blindness, cataracts, cardiovascular disease, and even death. Women of childbearing age who have hormonal imbalances as a result of bouts with infectious diseases or as a result of cancer treatments may experience fertility problems. Many cancers are fed by naturally occurring hormones such as estrogen, which produces granulose cell tumors, and androgen progen, which is responsible for leydig cell tumors.
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A number of noted endocrinologists have enhanced the study of hormonal abnormalities. American neurologist and surgeon Harvey Cushing (1869–1939), for instance, studied the functions of the pituitary gland, leading to the identification of Cushing’s disease, which results from a malfunction in the secretion of the hormones affecting carbohydrate metabolism. The chief function of thyroid hormones is to increase basal metabolic rate and control growth and development. Hyperthyroidism was first identified by Irish physician Robert Graves (1797–1853). Grave’s disease affects one percent of the total population and is more often found in females (2 percent) than in males (0.2 percent). The condition known as Addison’s disease, an abnormality of the adrenal cortex glands, was identified by British physician Thomas Addison (1795–1860). In addition to naturally produced hormones, artificial hormones, such as birth control pills, may be voluntarily taken to mitigate or block the effects of hormones produced by the body. Environmentalists contend that many of the artificial hormones that are inherent in certain chemicals are associated with cancer, infertility, endometriosis, fibroids, and immunosystem and thyroid disorders. Chemical-based hormones have also been blamed for learning and behavioral disorders, hyperactivity, and lower than average intelligence. Consequently, the United States Environmental Protection Agency (EPA) has been charged with researching chemicals suspected of disrupting human hormones. See Also: Birth Defects; Cancer (General); Diabetes;
Endocrine Diseases (General); Environmental Protection Agency (EPA); Gastroenterology; Gynecology; Kidneys; Liver Diseases (General); Menopause; Pregnancy.
Bibliography. Lindsey Berkson, Hormone Deception:
How Everyday Foods and Products Are Disrupting Your Hormones (McGraw-Hill, 2000); Sue Ann Binkley, Endocrinology (Harper Collins, 1995); George Fried and George J. Hademenos, Schaum’s Outline of Theory and Problems of Biology (McGraw-Hill Professional, 1999); Paul Gard, Human Endocrinology (Taylor and Francis, 1998); M.E. Hadley, Gastrointestinal Hormones (Prentice-Hall, 1992); David McKay Hart, Jane Norman, Gynaecology Illustrated (Churchill Livingstone, 2000); Christopher K Herwill. and John D. Flack, Endocrine Toxicology
(Cambridge University Press, 1992); John F. Laycock, and Peter H. Wise, Essential Endocrinology (Oxford University Press, 1996). Elizabeth R. Purdy, Ph.D. Independent Scholar
Hounsfield, Godfrey (1919–2004) British electrical engineer who was awarded a share in the Nobel Prize in Physiology or Medicine in 1979 for his contributions to the creation of the computerized axial tomography (CAT or CT) scanner. Hounsfield’s invention combined X-ray images with the aid of a computer to generate cross-sectional views and three-dimensional images of the internal organs and structures of the body. CAT scanners can be used, for example, to examine the head to identify traumatic injuries (such as blood clots or skull fractures), tumors, and infections. CAT scan methods can also be used to calculate the density of bone in the evaluation of osteoporosis. Hounsfield’s name is inextricably linked to his creation as the Hounsfield scale defines a quantitative measure of radiodensity used in assessing CAT scans. Hounsfield was born in Nottinghamshire, England, on August 28, 1919, the youngest of five children. He was fascinated with electronics from an early age, and in school, he had excellent results in physics and maths, but by his own admission, lacked interest in the other subjects offered at the Newark Magnus Grammar School. During World War II, he volunteered to join the Royal Air Force (RAF) as a reservist, which gave him the chance to learn the basic principles of electronics. While in the RAF, Hounsfield quickly became a radio mechanic instructor. One of his superiors noticed Hounsfield’s electronic skills and recommended him to the Faraday House Electrical Engineering College in London, where he obtained his diploma. After the war, he started working at EMI in Middlesex on radar and guided weapons. His personal interests, however, soon led him to research computers, which in the 1950s, were still in their primitive stages. Together with his team, Hounsfield designed
Household Poisons
the first all-transistor computer to be constructed in Britain, the EMIDEC 1100. It was in the late 1960s that Hounsfield began working on the project that would eventually lead to the creation of the CAT scanner. The first prototype of Hounsfield’s CAT scanner was designed to examine the head and, as the Nobel Committee’s statement pointed out, before that, “ordinary X-ray examinations of the head had shown the skull bones, but the brain had remained a gray, undifferentiated fog. Now, suddenly, the fog had cleared.” Hounsfield continued his research to perfect the scanner after the Nobel and he also successfully designed a whole-body scanner. Because of his invention, Hounsfield received many awards. In 1975, he was elected to the Royal Society. The following year, he was appointed Commander of the British Empire and, in 1981, he was knighted. Hounsfield died on August 12, 2004. See Also: Diagnostic Imaging; Diagnostic Tests. Bibliography. Caroline Richmond, “Sir Godfrey Houns-
field,” British Medical Journal (v.329, ��������������������� 2004); Susan Zonnos, Godfrey Hounsfield and the Invention of Cat Scans (Lane Publishers, 2002). Luca Prono Independent Scholar
Household Poisons Poisonings are an unfortunate but common worldwide occurrence. A poison is defined as a substance that through its chemical action usually kills, injures, or impairs an organism. Poisoning from household substances is sometimes because of children’s curiosity, although adults are also frequently poisoned as well, either accidentally or intentionally. Poison exposure is largely by ingestion, but may be through dermal, inhalational, or ocular routes. Poisoning from household substances is avoidable, thus it is imperative to educate the public, especially parents, of the dangers of common items. If poisoning is suspected, rapid emergency treatment is mandated, and should be done utilizing a Poison Control Center.
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The National Capital Poison Center lists the most common substances responsible for poisoning children—cosmetics, cleaning substances, medications, antiseptics, plants, vitamins, pesticides, and foreign objects such as coins. Although other, more dangerous items exist, household substances are readily available to children, and special precautions should be taken to keep them out of reach. In adults, the most common substances include pain medicines, sedatives, cleaning substances, antidepressants, alcohol, and cardiovascular drugs. The most toxic substances to humans are iron pills, cleaning products, hydrocarbons (gas, oil, and lighter fluid), pesticides, alcohol, windshield wiper fluid, and antifreeze. Iron pills (which resemble candy) are a common and especially fatal threat to children. The recommended dose for children less than 6 years of age is 10 milligrams/day. Supplements range from 18 to 150 milligrams/pill and as little as 600 milligrams is harmful to a small child. Signs and symptoms of iron poisoning include nausea/vomiting, gastrointestinal bleeding, shock, and coma. Death can ensue within hours. The Food and Drug Administration has taken precautions in dosing and packaging requirements to try to reduce the number of iron poisonings in children. Medications, both prescription and over the counter, should always be kept in childproof containers. Cleaning products are dangerous to children and adults alike due to their strong acid or base content. These include drain openers, toilet bowl cleaners, rust remover, and oven cleaner. They cause chemical burns, both internally and externally, and may damage the lungs after a long exposure in a poorly ventilated area, usually in adults who are cleaning using these products. Antifreeze and windshield wiper fluid often cause accidental poisonings. Antifreeze is especially attractive to children due to the sweet smell and taste of ethylene glycol, the main ingredient. If ingested, antifreeze can damage the nervous system, cardiovascular system, and kidneys. The patient may have a rapid heart rate, confusion, dizziness, seizures, and coma. The main toxin in wiper fluid is methanol. Pure concentrated methanol is extremely toxic and two tablespoons is fatal to a child. Six to eight ounces is harmful to an adult. Ingestion of wiper fluid, which contains a diluted solution of methanol, can cause blindness and death, and is a medical emergency.
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Many household plants such as aloe, holly, mistletoe, and azaleas, are poisonous to humans. Plants usually do not pose a problem unless the household has a young child who puts everything in his or her mouth. Aloe, a succulent houseplant used topically to treat minor cuts and burns, causes abdominal pain, diarrhea, and possible kidney damage if ingested. Mistletoe is a popular holiday decoration that can cause inflammation of the gastrointestinal tract. Holly berries contain toxins called saponins. Ingestion of two or three berries will cause gastroenteritis; 20 to 30 berries can be fatal. Azaleas are potentially fatal. If ingested, symptoms include decreased heart rate, decreased blood pressure, and paralysis. Alcohol is very dangerous—in small children, minimal amounts of liquor, beer, or wine can quickly lead to intoxication, followed by seizures, coma, and death. Mouthwash, colognes, and other household products also pose a threat. Previously, parents were encouraged to keep syrup of ipecac in case of accidental poisoning. Syrup of ipecac works by inducing emesis (vomiting). The medical community now discourages this practice. There is no evidence for the use of syrup of ipecac; it was just assumed that inducing vomiting would rapidly remove the poison and be of benefit. Emergency rooms today may use activated charcoal, which binds to and prevents the absorption of substances into the bloodstream. Additionally, patients with eating disorders may utilize syrup of ipecac for weight loss. If a poisoning is suspected, rapid medical attention is necessary to prevent long-term damage or death. Poison Control Centers are excellent resources in suspected poisoning, and are available nationally through a toll-free number (currently 1-800-222-1222). They are staffed by toxicologists, pharmacists, and other professionals who can give guidance as to whether a hospital trip is necessary, and are a resource available free of charge to both healthcare workers as well as the general public. This number should only be used in the case of a poisoning emergency, but if the patient is not conscious, 911 should be called first. Prevention is a better option, and many poisonings can be avoided by simply knowing which substances are dangerous and storing them properly. SEE ALSO: Poisoning; Environmental Toxicology; Agency
for Toxic Substances and Disease Registry; Mercury
Bibliography. American Academy of Pediatrics, Q and A: Poison Treatment in the Home, www.aap.org (cited October 2006); A.D.A.M. Medical Encyclopedia, Windshield Washer Fluid, www.nlm.nih.gov/medlineplus (cited 10 2006); Audrey Hingley, FDA Consumer: Preventing Childhood Poisoning, www.cfsan.fda.gov (cited October 2006); Mark Hostetler and Sandra Schneider, Emergency Medicine: A Comprehensive Study Guide, 6th ed., Access Medicine, www.accessmedicine.com (cited October 2006).
Gautam J. Desai, D.O. Elly K. Hughes, MS II Kansas City University of Medicine and Biosciences College of Osteopathic Medicine
Hughlings Jackson, John (1835–1911) John Hughlings Jackson was a leading physician, thinker, and writer who became known for his studies of epilepsy, speech defects, and nervous system disorders arising from injury to the brain and spinal cord. He has been called the “father” of English neurology, and pioneered the development of neurology as a medical specialty. Born on March 4, 1835, in Providence, Green Hammerton, Yorkshire, in England, he was the son of Samuel Jackson, a British yeoman, and Sarah Hughlings, the daughter of a Welsh revenue collector. During his career as a physician, he worked at the London Hospital (1859–94) and later in the National Hospital for Paralysis and Epilepsy (1862–1906), which was located in Regent’s Park, and was later moved to Queen Square, and renamed to what is today known as the National Hospital for Neurology and Neurosurgery. He was one of the first people to make the association between structural brain damage and abnormal mental states. He was the first to describe in 1863 a type of epilepsy known today as Jacksonian epilepsy or Jacksonian seizures, after observing his wife’s epileptic seizures, which would always follow a similar pattern. They would start at one of her hands, progress to her wrist, then move to her shoulder, and finally to her face. Finally, they would
Human Genome Organization, The (HUGO)
affect the leg on the same side of her body, and ultimately stop. He thus went on in 1875 to attribute the seizures to the motor region of the cerebral cortex (the external layer of the brain). In 1881, he was also the first to describe a type of epilepsy now known as temporal lobe epilepsy. His work on epilepsy paved the way to the development of modern methods to find brain lesions and the investigation of localized brain functions. Besides his comprehensive studies on epilepsy, he was also one of the first to recognize the pattern of disease of the cerebellum (the part of the brain which coordinates, among other functions, balance and posture), and also developed research in the realm of aphasia (a speech disorder) and neuro-ophtalmology. In 1864, he confirmed the discovery by Paul Broca (a French surgeon) that the speech centre in right-handed persons was located in the left hemisphere and vice versa. He was elected a Fellow of the Royal Society of London for the Improvement of Natural Knowledge in 1878. He was also one of the founders of the renowned British specialist journal Brain, along with David Ferrier and James Crichton-Browne, two friends who were prominent neurologists at the time. The journal, which is still published today, covered the interaction between experimental and clinical neurology. He died in London on October 7, 1911. SEE ALSO: Epilepsy; Neurologist; Neurology; Neurologic
Diseases.
Bibliography. Macdonald and Eileen A. Critchley, John
Hughlings Jackson: Father of English Neurology (Oxford University Press, 1998). Tiago Villanueva Centro Hospitalar de Lisboa-zona central
Human Genome Organization, The (HUGO) The Human Genome Organization (HUGO) was established by a group of scientists in 1989 to promote and sustain international collaboration in the field of human genetics. The organization’s primary objec-
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tives are to investigate the nature, structure, function, and interaction of the genes, genomic elements, and genomes of humans and relevant pathogenic and model organisms; to characterize the nature, distribution, and evolution of genetic variation in humans and other relevant organisms; to study the relationship between genetic variation and the environment in the origins and characteristics of human populations and the causes, diagnoses, treatments, and prevention of disease; to foster the interaction, coordination, and dissemination of information and technology between investigators and the global society in genomics, proteomics, bioinformatics, systems biology, and the clinical sciences by promoting quality education, comprehensive communication, and accurate, comprehensive, and accessible knowledge resources for genes, genomes, and disease; and, to sponsor factually grounded dialogues on the social, legal, and ethical issues related to genetic and genomic information and championing the regionally appropriate, ethical utilization of this information for the good of the individual and the society. Membership is open to all persons concerned with the human genome or related scientific fields. HUGO is governed by a General Assembly of its membership that convenes once a year to set, steer, and evaluate policy. The Assembly elects officers and an 18-member Executive Council to serve the day-to-day operational needs of the organization. HUGO is incorporated in Geneva, Switzerland, and has three regional offices: the North American office in Bethesda, Maryland, the European office in London, and the Pacific office in Osaka, Japan. Funding for the organization comes from a number of nongovernmental foundations including the Howard Hughes Medical Institute, the Lucille P. Markey Charitable Trust, and the Wesley Foundation. Each year HUGO holds its annual Human Genome Meeting (HGM) designed to update and increase knowledge in the ever-evolving field of human genome research. The meetings center on a stimulating and interesting program of plenary lectures, symposia, workshops, and include poster presentations and social events which all help to make any HGM the ideal forum to share information and results with researchers in both science and industry. The organization also sponsors a number of other meetings and workshops throughout the year
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to disseminate information on specific topics, and publishes a newsletter, the Genome Digest. HUGO’s Travel Awards Program is intended to encourage and assist younger scientists involved in the analysis of the human genome. Specifically, the program is designed to enable young investigators to travel from their country of residence to a laboratory in another country for the purpose of learning a new method or technique which can then be brought back and introduced to their home laboratory; and to facilitate collaborative research among laboratories involved in the analysis of the human genome. See Also: Genetics; Genomic Library. Bibliography. Centre for Life, www.life.org.uk (cited
September 2006); Rodney Loeppky, Encoding Capital: The Political Economy of the Human Genome Project (Routledge, 2005); The Human Genome Organization, www. hugo-international.org/index.htm (cited September 2006); Human Genome Project Information, www.ornl.gov/ sci/techresources/Human_Genome/home.shtml; World Health Organization: Genetics Resource Center, www. who.int/genomics/en (cited September 2006). Ben Wynne, Ph.D Gainesville State College
Human Development Report ranks Hungary 35th in the world on overall quality-of-life issues. The Health Insurance Fund (HIF) is responsible for providing healthcare in Hungary, and local governments receive grants from the central government to administer the health program. Governments negotiate contracts with various providers to provide coverage for most of the population. The National Public Health Program has been implemented to improve general health, and the government has established goals that include increasing life expectancy by three years and slashing rates of major illnesses and injuries. Targeted areas include reducing the smoking rate, preventing and treating alcohol and drug abuse, promoting better diet and lifestyles, expanding sex education programs, improving the environment, and preventing epidemics. Social security is funded by employee and employer contributions supplemented by the government. The program covers workers, the self-employed, apprentices, entertainers, attorneys, civil servants, ministers, and the unemployed. Other Hungarians can buy into the pension plan. The government spends an average of six percent of the total budget on healthcare. In international dollars, $1,269 is allotted per capita, and the government earmarks 8.4 percent of the Gross Domestic Product
Hungary The central European nation of Hungary has one of the two strongest economies of all transition countries, and the per capita income of $16,300 is one-half that of the Big Four nations. Hungary is considered the 62nd richest nation in the world. Growth continues to be strong (4.1 percent). Despite a number of economic gains, the government has been beset by unsustainable budgets, current account deficits, inflation (14 percent) and unemployment (7.2 percent). Labor participation is low at only 57 percent. Hungary has a poverty rate of 8.6 percent of the population. The Gini coefficient is 24.4, and the richest 10 percent of Hungarians hold 20.5 percent of resources as compared to 4.1 percent for the poorest 10 percent. The overall standard of living is relatively high, and the United Nations Development Programme’s (UNDP)
In Hungary, $1,269 in international dollars and 8.4 percent of the Gross Domestic Product (GDP) are allocated for healthcare.
Huntington’s Disease
(GDP) for health. Government spending accounts for 72.4 percent of all government expenditures in Hungary, and 83.4 percent of that spending is directed toward social security programs. The private sector supplies 27.6 percent of all health funding, and 88.90 of private spending is generated by out-of-pocket expenses. There are 3.33 physicians, 8.85 nurses, 0.21 midwives, 0.54 dentists, and 0.52 pharmacists per 1,000 population in Hungary. The population of 9.981,334 Hungarians experiences a life expectancy of 72.77 years, with females outliving males an average of nine years. Literacy is widespread, and less than three percent of the population over the age of 15 are unable to read and write. All of the relevant population is enrolled in primary and secondary school. While all urban residents have sustained access to safe drinking water and improved sanitation, two percent of rural residents lack access to safe drinking water and 15 percent lack access to proper sanitation. Around 77 percent of Hungarian women use some method of birth control, and Hungarian women have the 14th lowest fertility rate in the world, giving birth at a rate of 1.32 children each. All births are attended by trained personnel, and the adjusted maternal mortality rate is 16 deaths per 100,000 live births. Between 1990 and 2004, both infant and underfive mortality were more than halved, dropping from 15 to seven and from 17 to eight deaths per 1,000 live births respectively. Currently, infant mortality is reported at 8.39 deaths per 1,000 live births. Nine percent of infants are underweight at birth. Two percent of under-5 are moderately underweight, and two percent suffer from wasting diseases. Three percent are moderately to severely stunted. Infant immunization rates are reported at 99 percent for diphtheria, pertussis, and tetanus (DPT1 and DPT3), tuberculosis, polio, and measles. Environmentally, Hungary has been left with many problems common to former Soviet bloc nations, and government resources have been strained as officials endeavor to reduce air, soil, and water pollution to meet European Union (EU) guidelines. Hungary has a 0.1 percent adult prevalence rate of HIV/AIDS. Around 2,800 people currently have the disease, but it has proved fatal to less than 100 people. Meningococcal disease was reported in Hungary in January 1999. Circulatory diseases, cancer, and accidents are the three leading causes of death.
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See Also: European Public Health Alliance (EPHA)
Healthcare, Europe.
Bibliography. William H. Berqquist, Freedom: Narra-
tives of Change in Hungary and Estonia (Jossey-Bass, 1994); Central Intelligence Agency, “Hungary,” World Factbook, www.cia.gov (cited July 2007); Commission on the Status of Women, “Hungary,” www.un.org (cited July 2007); Martin A. Levin and Martin Shapiro, eds., Transatlantic Policymaking in an Age of Austerity: Diversity and Drift (Georgetown University Press, 2004); UNICEF, “Hungary,” Social Security Administration, “Hungary,” www.ssa.gov (cited July 2007). Elizabeth R. Purdy, Ph.D. Independent Scholar
Huntington’s Disease The brain is a complex organ with numerous connections and interconnections that both aid in its study and confound it. Because of the intricate network of connections between brain cells, a disease that leads to degeneration of a specific population of brain cells can have a drastic effect on the brain as well as on the patient as a whole. There are many examples of neurological disorders; one prominent example is Huntington’s disease (HD). Within the brain, there are regions that control specific facets of brain function. For example, there is a region where all somatosensory information is ultimately processed, and another region where smells are processed. There is also a brain region that sends a signal to initiate body movement. Many brain functions integrate information from various brain regions. Movement is one such example. A major brain region that has important feedback on movement is the basal ganglia. The basal ganglia is itself made up of several distinct brain regions. The two most common disorders of the basal ganglia are Parkinson’s disease (PD) and Huntington’s disease. A person affected with PD will not be able to move as much as a healthy person, whereas someone with HD will exhibit excess, uncontrolled movements. A characteristic movement is a ballismus, or large forceful movement that usually occurs in the arms. The brain is composed of two main types of cells, neurons and glia. Neurons are cells that send electrical
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signals within the brain or down to the spinal cord. Glia are the support cells. Within the neurons, there are multiple subtypes. One such subtype is called the medium spiny neurons. They are medium in size, relative to other neurons, and have spiny-appearing projections from the cell body by which they send and receive electrical signals. Medium spiny neurons reside in the basal ganglia, and these cells degenerate in HD. Along with movement disorders, HD can cause intellectual degeneration as well as emotional disorders. There is currently no known treatment or cure for HD. The only medications used can alleviate some movement or emotional problems. Research is focused on the genetic cause of HD, which is a mutation in the huntingtin gene. This gene encodes the huntingtin protein, which as of yet has no known effect in brain cells. The type of mutation in the huntingtin gene is called a trinucleotide repeat expansion. When DNA encodes a protein, every three nucleotides of the coding DNA stand for one particular amino acid to be added to the protein. Certain rare arrangements of nucleotides make a gene prone to trinucleotide repeat expansion, or abnormal multiple repeats of the trinucleotide segment. In HD, the trinucleotide repeat occurs in the coding region of the huntingtin gene; therefore, the resulting protein has an excessive string of one amino acid within the central region of the protein, resulting in a mutant protein of altered shape and size which can no longer function as normal. In the case of huntingtin, the mutated protein takes on a new toxic function, unrelated to the normal protein’s function. The excess amino acid is glutamine. The mutated huntingtin protein leads to death of the medium spiny neurons and subsequently HD. The mutation is dominant; only one of the two copies of the gene need be mutated in order to get the disease. Thus a child of an HD parent has a 50-percent chance of inheriting HD. The disease usually manifests itself around the age of 40 or 50 years. Until then, a person may live a normal healthy lifestyle. In rare cases, an individual begins to exhibit HD symptoms before the age of 20. This early HD is called juvenile Huntington’s disease. Generally, a person with the mutated huntingtin gene will develop HD at the same age as the affected parent. Genetic testing can be carried out to determine if an individual will have HD even before symptoms occur; because
knowledge of the impending disease may cause severe anxiety and stress, and there is currently no treatment, such testing is not typically recommended unless in the case of family planning. In the vast majority of HD patients, the mutated gene is inherited from a parent. In about 2 percent of the cases, the disease results from a spontaneous mutation in the huntingtin gene. The name Huntington’s disease dates back to 1872, when Dr. George Huntington of Ohio first described it in a medical paper. The disease was initially called Huntington’s chorea or chorea major, due to the dance-like movements of HD patients. HD is rare, affecting approximately 8 people in 100,000 globally. It is more common in western Europeans, and nearly unseen in Asians and Africans. SEE ALSO: Brain Diseases; Diagnostic Tests; Genetic Brain
Disorders; Genetic Code; Genetic Disorders; Genetic Testing/Counseling; Genetics; Gerontology; National Institute of Mental Health (NIMH); National Institute of Neurological Disorders and Stroke (NINDS); National Institute on Aging (NIA); Neurological Diseases (General); Parkinson’s Disease; Tremor. Bibliography. Jean Barema, The Test: Living in the Shad-
ow of Huntington’s Disease (Franklin Square Press, 2005); ICON Health Publications, The Official Patient’s Sourcebook on Huntington’s Disease: A Revised and Updated Directory for the Internet Age (ICON Health Publications, 2002); Richard R. Karlen, Devil’s Dance (Ironbound Press, 1998); Oliver Quarrell, Huntington’s Disease: The Facts (Oxford University Press, 1999). Claudia Winograd University of Illinois at Urbana-Champaign
Hydrocephalus The word hydrocephalus is derived from the Greek words meaning “water” and “head,” and thus is defined as the accumulation of cerebrospinal fluid (CSF) in the ventricles of the brain, causing their enlargement and swelling. The estimated prevalence worldwide is 1 to 1.5 percent, or approximately 60 million individuals. It is one of the most common neurologic problems that affect humankind.
There are two major types of hydrocephalus: obstructive (noncommunicating) and nonobstructive (communicating). Obstructive hydrocephalus occurs when the normal circulation of CSF is blocked (obstructed), usually between the third and fourth ventricles at the aqueduct of Sylvius. Nonobstructive hydrocephalus is a result of poor absorption of CSF at the level of the arachnoid granulations; the flow of CSF in nonobstructive hydrocephalus is otherwise normal. Hydrocephalus can also be caused by excessive CSF production, such as with a choroid plexus papilloma. An example of nonobstructive hydrocephalus is normal pressure hydrocephalus (NPH), a common neurologic problem that afflicts the elderly. Patients are usually older than 60 years and males are affected slightly more often than women. The classic clinical triad is dementia, gait disturbance, and urinary incontinence. The hydrocephalus is termed normal pressure because the opening pressure on lumbar puncture is nonelevated. Other specific types of hydrocephalus include hydrocephalus ex vacuo (enlargement of the ventricles due to loss of cerebral tissue, that is, cortical atrophy, which can occur naturally with age), hydranencephaly (absence of a substantial amount of brain tissue), external hydrocephalus (enlarged subarachnoid spaces over the frontal lobes), arrested hydrocephalus (hydrocephalus without symptoms), and entrapped fourth ventricle (a fourth ventricle that does not communicate with the third ventricle). Etiologies of hydrocephalus can be divided into two broad categories: congenital and acquired. Congenital causes of hydrocephalus include neural tube defects, Chiari malformations, aqueductal stenosis, aqueductal gliosis, Dandy-Walker malformations, X-linked inherited disorders, and intrauterine infection. Acquired causes of hydrocephalus include infections (i.e., meningitis, cysticercosis), hemorrhage (i.e., subarachnoid hemorrhage, intraventricular hemorrhage), masses, postoperative changes, neurosarcoidosis, and spinal tumors. The signs and symptoms of active hydrocephalus in young children include an enlarging cranium, irritability, poor head control, nausea and vomiting, enlargement and engorgement of scalp veins, cranial nerve VI (abducens) palsy, upward gaze palsy, hyperactive reflexes, and irregular respirations. In older children and adults, other symptoms include papill-
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edema (swelling of the optic nerves on ophthalmologic examination), headaches, and gait changes. The treatment of hydrocephalus can be procedural, medical, or surgical. Procedural treatment of hydrocephalus is accomplished with spinal taps (lumbar puncture), which drains out CSF. Medical treatment is accomplished with diuretics, particularly acetazolamide; this, however, is only a temporary measure. The definitive treatment of hydrocephalus is surgical, of which there are four options. Choroid plexectomy is a procedure that targets the choroid plexus, which is present in the brain’s ventricles and produces CSF. Another option is to open a narrowed Sylvian aqueduct. Third ventriculostomy is a surgical procedure in which holes are made in the floor of the third ventricle, allowing CSF to drain into the basal cisterns of the brain. This procedure is typically done endoscopically and recent studies have shown it to be more beneficial in younger patients. Last, the most common surgical option is shunting. There are three main different kinds of shunts used in practice today: ventriculoperitoneal (VP), ventriculoatrial (VA), and lumboperitoneal (LP). VP shunts are the most common type of shunt used and divert CSF from the lateral ventricle to the abdominal peritoneum. VA shunts divert CSF from the ventricles to the right atrium of the heart, and are the treatment of choice when abdominal abnormalities are present in the patient. The prevalence of shunts in the United States is greater than 125,000. Although shunts are the most important intervention in the treatment of hydrocephalus, they are associated with complications. Some of the most common problems that occur with shunts include undershunting, overshunting, infection, seizures, and skin breakdown. Shunts can also become obstructed or disconnected, and cause peritonitis, hydrocele, ascites, volvulus, or intestinal strangulation. A rare but serious complication of shunt malfunction or hydrocephalus is blindness. This can occur via three mechanisms: occlusion of the posterior cerebral arteries caused by herniation of the brain, chronic papilledema, and/or dilatation of the third ventricle with compression of the optic chiasm. People will always suffer from hydrocephalus, and survival is poor if the condition is left untreated. Fortunately, different organizations from developed countries travel abroad to help those in
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third world countries with limited access to neurosurgeons. The most notable of these is Project Shunt, based out of the University of Michigan, which travels to Guatemala annually to operate on those in need. Hopefully, the options for treatment of this serious disorder will continue to improve, with minimal side effects or complications. SEE ALSO: Blindness; Brain Cancer; Meningitis; Sarcoid-
osis; Spinal Cord Diseases.
Bibliography. Mark S. Greenberg, Handbook of Neuro-
surgery, 5th ed. (Thieme, 2001); Chuck Toporek and Kellie Robinson, Hydrocephalus: A Guide for Patients, Families and Friends (Patient-Centered Guides, 1999).
Khoi D. Than, M.D. Johns Hopkins University School of Medicine
Hygiene The development of hygiene and hygienic practices has been fundamental in preventing infections through cleanliness, and has also been very important in helping patients recover from ailments. On a personal level, it involves washing hands and the body with clean water. Domestic hygiene demands having a clean house environment, with occupational hygiene meaning that workers have a clean workplace. The word itself is derived from Hygieia, the Greek goddess of health and sanitation, who was known as Salus in the Roman Empire. As a word, it first appeared in French as hygiaine in 1597, and Salmon in 1671 noted that there were three speculative parts in medicine: physiology, hygiene, and pathology. Knowledge about hygiene and cleanliness and the need for it was clearly evident in ancient times with references to it in a number of ancient Hindu texts such as the Hausmriti and the Vishnu Purana. Indeed bathing is one of the daily duties of Hindus, with the custom of washing in the Ganges River at Benares and elsewhere having great symbolic importance. Washing was also practiced by large numbers of ancient peoples with the Romans constructing large public bath houses, while wealthy Romans had their own private bath houses. These often involved a range of
pools, some with hot water, and some with cool water, while there were also facilities for massage with oil or scraping the skin with a metal “strigil.” The water was kept fresh by use of the aqueduct. The most impressive of the baths in the Roman Empire were the Baths of Caracalla, in Rome, built from 216 c.e., to accommodate 1,600 bathers. In the New Testament of the Bible, the concept of baptism involves total immersion in water to cleanse one of sins, with Jesus also being involved in the washing of the feet, a practice that has continued into modern times in the Christian Church on Maundy Thursday (the last Thursday before Easter), with the Pope washing the feet of the subdeacons. The Koran prescribes a number of customs surrounding good hygiene, and Muslims wash their faces under running water, and their feet and hands at mosques. As well as personal cleanliness, the cleaning of wounds has been found to be essential in helping them heal quickly. In Anglo-Saxon times in Britain and some parts of Europe, there was a custom of using honey to treat wounds, but by medieval times, it would found that the wound would heal much faster if washed in clean water. Although it is now regarded as a healthy and hygienic practice to wash regularly, with many people having a shower at least once a day, this has not always been the case, and was not possible in much of the world where people did not have ready access to fresh water. Although people living near the sea and rivers were able to bathe easily, with the increase in population around the world, and the growth of cities, increasingly more people had to rely on water which was often not fresh. This led to outbreaks of disease such as cholera. During Elizabethan times in England, Queen Elizabeth I (reigned 1558–1603) and some other wealthy people took up bathing in seawater which was regarded as more hygienic by many people. To do this, bathing boxes were constructed, with the box moved into the seawater, and the person able to bathe inside the box. However there were some people who claimed that washing would remove a protective layer of skin With increasing interest in personal hygiene, and the growth of cities with consequent overcrowding, and also problems with removal of human waste, the hygiene of buildings became important during Victorian England. In November 1871, Edward, the
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Nowadays, most primary schools around the world teach children to observe hygienic practices. This involves, at its most basic, washing one’s hands after going to the lavatory, or touching animals, washing the body and hair frequently, and washing of hands before eating. To this is added oral hygiene, with regular brushing of teeth, frequently washing hands, wrists and faces, and the regular washing of clothes and the wearing of clean clothes, as well as living in a clean environment. They are also taught to wash wounds, and not to share cutlery, as well as wash plates after meals and throw out uneaten food. See Also: Food Safety; Foodborne Diseases. Bibliography. A. Leslie Banks and J.A. Hislop, Health
Most primary schools teach children to observe hygienic practices including washing one’s hands after going to the lavatory.
Prince of Wales (later Edward VII) fell ill at Londesborough Lodge, Scarborough, after having contracted typhoid fever. After huge public concern about what had happened, a medical doctor, William Henry Corfield (1843–1903) attached to University College London, writing to The Times newspaper was able to narrow the problem down to poor house sanitation. This led to new design standards being introduced for public buildings, and the doctor concerned wrote 32 books and treatises on aspects of hygiene in buildings. In the late 19th century, and the early 20th century, there was an increasing emphasis on workplace hygiene. Hospitals and public buildings, especially schools, were regularly cleaned with disinfectant. However, many factories and mines continued to have people working in unhygienic conditions. The English writer D.H. Lawrence (1885–1930) wrote often of his father returning from the coal mine covered in coal dust. This led to regular demands for the provision of facilities at mines and in factories to allow workers to wash, and have ample and clean lavatories. These basic requirements were gradually introduced from the 1930s, although some mines and factories in less developed countries often have people working in unhygienic conditions, even now.
and Hygiene (University of Tutorial Press, 1965); L.B. Escritt and Sidney F. Rich, The Work of the Sanitary Engineer (Macdonald & Evans, 1949); Michael Hau, The Cult of Health and Beauty in Germany: A Social History 1890– 1930 (University of Chicago Press, 2003); Heikki Mikkeli, Hygiene in the Early Modern Medical Tradition (Academia Scientiarum Fennica, 1999); Henry E. Sigerust, Landmarks in the History of Hygiene (Oxford University Press, 1956); Leonie Mosel Williams, Health, Life and Living (Heinemann, 1998). Justin Corfield Geelong Grammar School, Australia
Hyperactivity Hyperactivity is a condition where people become abnormally excitable and exuberant. Although the condition must have existed for thousands of years, the word itself is relatively new, being first used in its present context in the 20th century. Some people show symptoms of hyperactivity naturally, with the condition varying considerably from one person to another. It is generally believed to be common for children who have a very short concentration span and want to constantly be involved in a form of activity. Often, it may involve strong emotional reactions, and may show itself in symptoms such as fidgeting, constant movement, and an inability to concentrate for long. At its worst, hyperactivity can become
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serious because it can inhibit learning in schools, the following of emergency instructions, or getting along with colleagues in the workplace, and can, on occasions, be harmful to themselves and/or others. Medical research in hyperactivity is generally connected with what has been called attention deficit hyperactivity disorder (ADHD), with experts disputing the level of its prevalence in society. Under normal circumstances, young children can be lively and have short attention spans. Similarly, teenage children can also, at times, have short attention spans through puberty. Boredom and suffering from mental conflict such as problems at home can also lead to hyperactivity. This often reflects itself on children being unsettled at school, or an inability to read for any substantial period, and with children being keen to involve themselves in activities including those that are antisocial. At home, it also reflects itself in not being able to concentrate on any specific task, watching television, and constantly changing between channels, or being unable to maintain a reasonable posture throughout a meal or other family occasion. There have been many views as to how hyperactivity can be caused. Popular beliefs involve the consumption of too much sugar, either through red-colored cordial, or more often, through largescale consumption of sugary soft drinks, especially those that contain caffeine, certain chocolate confections, and the like. Teachers and parents often claim that eating particular food or drinking specific drinks do result in children becoming far more rowdy, excitable, and energetic, and this has led to some schools trying to change the food children eat either by providing healthier food for school lunches or trying to influence their choices by not making certain items available. In recent years, there have been a number of books that have been published which seek to answer problems raised by parents and teachers. SEE ALSO: Attention Deficit Disorder with Hyperactivity. Bibliography. Robert V. Kail, Children and Their Devel-
opment (Pearson Prentice Hall, 2007); Gwnedd Lloyd, Joan Stead, and David Cohen, eds., Critical New Perspectives on ADHD (Routledge, 2006); Richard A. Lougy, Silvia L. DeRuvo, and David K. Rosenthal, Teaching Young Children
with ADHD: Successful Strategies and Practical Interventions for PreK–3 (Sage, 2007); Sami Timini, Naughty Boys: Anti-Social Behavior, ADHD and the Role of Culture (Palgrave Macmillan, 2005). Justin Corfield Geelong Grammar School, Australia
Hypoglycemia Hypoglycemia is a clinical syndrome characterized by episodes of low blood glucose (sugar). These episodes can be accompanied by marked autonomic manifestations. There are no specific symptoms of hypoglycemia, but they may include hunger, feelings of anxiety, sweating, nausea, trembling, dizziness, visual disturbances, drowsiness, difficulty speaking, fatigue, palpitations, confusion, and headache. Serum glucose is measured and classified as being low, normal, or elevated. Currently, 70 to 100 mg/dL is considered to be normal. Symptoms of hypoglycemia usually occur when blood glucose levels are less than 50 to 60 mg/ dL. Hypoglycemia is a syndrome with diverse etiologies; therefore, treatment should be aimed toward the specific etiology. Glucose is a form of sugar that the body uses as fuel. Carbohydrates are the main dietary sources of glucose. After a meal, glucose is absorbed into the bloodstream and distributed to the body’s cells where it is used for energy. Blood glucose homeostasis involves complex interactions between the central nervous system and the endocrine system. The primary glucoregulatory organs are the liver, pancreas, adrenal glands, and pituitary gland. These organs regulate glucose through the release of hormones including insulin, glucagon, epinephrine, norepinephrine, glucocorticoids, and growth hormone. Insulin is the primary regulator of glucose metabolism; it acts predominantly on the liver, skeletal muscle, and adipose (fat) tissue. Insulin is produced by the pancreas and acts to suppress endogenous glucose production, stimulates glucose use, and promotes conversion to glycogen for storage. Ultimately, it acts to lower the blood glucose levels. When hypoglycemia occurs, the body acts in defense by decreasing insulin secretion. Glucagon
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and epinephrine also protect the body from acute hypoglycemia by stimulating the release of glucose from the liver. They do this through two processes: glycogenolysis and gluconeogenesis. The former process is the breakdown of glycogen into glucose for immediate use. The latter is generation of new glucose. Other hormones such as growth hormone and cortisol protect from hypoglycemia over prolonged periods of time. Evaluating a patient with hypoglycemia can be quite complex. Koch’s postulates of hypoglycemia underlines the steps to evaluating patients with hypoglycemia. First, recognize the patient’s symptoms could be caused by hypoglycemia. Second, document that the patient’s serum glucose concentrations are low while the patient is symptomatic. Third, show that the symptoms can be relieved by the administration of glucose. The goal is to diagnose hypoglycemia and any other clinically relevant associated diseases. A patient with serum glucose less than 60 should be evaluated for a hypoglycemic disorder. A patient with low blood glucose in the absence of symptoms does not need further evaluation. However, repeated episodes of hypoglycemia necessitate evaluation. In healthy persons, isolated episodes of hypoglycemia may result from accidental or intentional drug ingestion such as alcohol, salicylates, sulfa medications, haloperidol, pentamidine, and quinine. It may also be factitious, caused by accidental or intentional ingestion of hypoglycemic agents such as insulin, or a side effect of certain medications. Insulinomas are rare tumors that produce excessive amounts of the hormone insulin, which leads to hypoglycemia. Hypoglycemic disorders can be categorized as fasting or postprandial/reactive, or insulin mediated or noninsulin mediated. However, it is more useful to classify the patient according to symptoms and differentiate the sick from not sick. The patient may have hypoglycemia alone or it may be part of a disorder. A detailed evaluation is key with a thorough review of the patient’s past medical history and medication history. The differential diagnosis is different for different age groups. For example, hypoglycemia is rare in the pediatric population. The most common cause of hypoglycemia in noninsulin-dependent children over the age of 1 year is idiopathic ketotic hypoglycemia. This is a syn-
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drome that occurs after periods of fasting or during times of illness; it resolves with glucose administration. In neonates, infants, and children, hypoglycemia may be caused by inborn errors of metabolism. Common etiologies among adults include diabetic medication, ethanol (alcohol) use, and sepsis. In diabetic patients, hypoglycemic medications, inadequate food intake, increased physical exertion, illness, and drug interactions can all lead to hypoglycemia. Treatment depends upon the etiology, but usually involves the administration of dextrose orally or intravenously. SEE ALSO: Diabetes; Endocrinology. Bibliography. W.J. Brady, and A.H. Richard, “Section
17—Endocrine Emergencies,” in Emergency Medicine: A Comprehensive Study Guide, http://statref.com (cited September 2006); F. J. Service, IX Hypoglycemia, ACP Medicine, http://statref.com (cited September 2006). Christina Murray Angela J. Garner, M.D. University of Missouri–Kansas City School of Medicine
Hypothermia Hypothermia refers to when the body’s temperature falls below a temperature necessary to maintain normal metabolic functions. The normal body temperature is 37 degrees C and hypothermia occurs when the body drops to below 35 degrees C. Nearly 700 people die each year from hypothermia in the United States. There are many causes of hypothermia such as decreased heat production. This can be because of endocrine abnormalities such as hypopituitarism or hypothyrodism. Decreased heat production can also be due to hypoglycemia or malnutrition. It is important to consider these causes of hypothermia when a person’s normal body temperature does not rise through treatment, such as blankets and warming. Another cause of hypothermia can be due to increased heat loss. There are many factors that can lead to this cause, such as immersion in a cold body of water, or being in cold weather without sufficient clothing. Another common cause of increased heat loss is due
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Hypothermia occurs when the body drops to below 35 degrees Celsius and kills nearly 700 people per year in the United States.
to alcoholic intoxication. Alcohol causes cutaneous vasodilation of arteries which warms the skin. Core body temperature decreases due to shunting of blood to the periphery and leads to hypothermia. Finally, another cause of hypothermia is impaired thermoregulation which is caused by failure of the hypothalamus to regulate body temperature. At-risk populations for hypothermia are elderly adults, children, and mentally impaired individuals. Different publications have different criteria to determine mild, moderate, and severe hypothermia. In general, mild hypothermia begins when the temperature of the body falls below 35 degrees C but is still above 32 degrees C. The person will show signs of shivering, pale blue skin, slurring speech, confusion, and respiratory rate may increase. Moderate hypothermia occurs when body temperature is between 28 to 32 degrees C. Patients present in a stupor, they usually are not shivering anymore, body becomes rigid, and breathing becomes shallower. Severe hypothermia occurs when the body temperature is below 28 degrees C. Symptoms of severe hypothermia include difficulty breathing, unconsciousness, no pulse, and extreme rigidity. Patients with severe hy-
pothermia also have an increased risk for ventricular arrhythmias, which can be life threatening. There are many tests and observations that can be done that will tell if a person is hypothermic. If the person can voluntarily stop his or her shivering then he or she most likely has mildly hypothermic. Another test is to ask the patient to count backward from 100 by a certain multiple, such as six. This requires higher reasoning by the brain and if the person is hypothermic they will not be able to accomplish this task. Another test is to check the radial pulses. If the person has a very faint or no radial pulse, then they are most likely severely hypothermic. Treatment for patients with hypothermia is to slowly warm the body back to normal body temperature. Remove the person from the external stimulus that may be causing the hypothermia, such as cold water. Also provide warm beverages for the person to drink and monitor his or her breathing. Do not apply direct heat to a person that is hypothermic, such as a heating pad or warm water. If a heating pad is placed on the arm or legs, then cold blood will get shunted to the core and can lead to complications. Also do not massage the body of the person who is hypothermic. Individuals who are hypothermic are at an increased risk for cardiac complications and so massaging the body can exacerbate this risk. In the hospital, doctors will treat hypothermia differently based on the severity and cause. In general, doctors will use blankets and external actions to warm the body. If the patient is severely hypothermic, the doctor may infuse warm fluids into the person or have the person placed on hemodialysis. Most people with hypothermia recover without any long-term complications. SEE ALSO: Alcoholism; Alcohol Consumption; Alzheim-
er’s Disease; Parkinson’s Disease; Hypopituitarism; Hypothyroidism. Bibliography. Rick Curtis, “Outdoor Action Guide to
Hypothermia and Cold Weather Injuries,” www.princeton. edu (cited November 2007); “Hypothermia,” www.mayoclinic.com (cited December 2006); “Hypothermia,” www. webmd.com (cited January 2007); Vinay Kumar, et al., Pathologic Basis of Disease (Elsevier Saunders, 2005). Pavan Bhatraju University of Louisville
I Iceland Located in northern Europe between the Greenland Sea and the North Atlantic, the island of Iceland has the second highest living standard in the world according to the United Nations Development Programme’s (UNDP) Human Development Report and is outranked only by Norway. With a per capita income of $35,700, Iceland ranks as the 12th richest nation. Although the fishing industry employs only four percent of the labor force, it generates 70 percent of export earnings. The standard of living is high, and Iceland scores particularly high on literacy, longevity, income, and social cohesion. Income is fairly evenly distributed, and unemployment is extremely low (2.1 percent). The government provides a broad safety net that includes universal access to healthcare and a generous housing subsidy. Government spending on healthcare is extremely high in Iceland, and the government allocates an average of 26 percent of the total budget to health. In international dollars, Iceland spends $3,110 per capita, with 10.5 percent of the Gross Domestic Product (GDP) earmarked for health programs. Due to the national plan, approximately 85 percent of healthcare spending is generated by the government, and 36.5 of that spending is used to finance social security, which
is mandatory. The only private funding of healthcare in Iceland is derived form the 15 percent service fee required of all Icelanders. There are 3.62 physicians, 13.63 nurses, 0.60 midwives, 1.00 dentists, and 1.30 pharmacists per 1,000 population in Iceland. In 1990, Parliament passed Health Services Act No. 97, which guarantees universal healthcare access to Icelanders to protect their mental, social, and physical health. The national health plan is financed through taxes (85 percent) and user fees (15 percent). Iceland is divided into healthcare regions, and primary health centers are located throughout each region. These centers provide routine healthcare, disease prevention, and home care. The centers also have responsibility for family planning, school health, and mother and child healthcare. Iceland’s population of 299,388 enjoys a life expectancy of 80.31 years, the 11th highest life expectancy rate in the world. Females outlive males an average of four years. Access to education at both the primary and secondary levels is universal, and 99 percent of the population over the age of 15 is literate. All Icelanders have access to safe drinking water and improved sanitation. Women give birth to an average of 1.92 children. Between 1990 and 2004, infant mortality was slashed by two-thirds in Iceland, falling from six to two
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deaths per 1,000 live births. The current infant mortality rate of 3.29 deaths per 1,000 live births is the fifth lowest in the world. During that same period, under-5 mortality fell from seven to three deaths per 1,000 live births. Icelandic children are remarkably healthy, but four percent of infants are underweight at birth. All infant immunization rates are in the 90s: 99 percent of infants are immunized against diphtheria, pertussis, and tetanus (DPT1 and DPT3), polio, and Haemophilus influenzae type B, and 93 percent are immunized against measles. Periodic earthquakes threaten the general wellbeing in Iceland. Environmental threats include water pollution caused by the runoff from fertilizer and the government’s inability to sufficiently treat wastewater. HIV/AIDS is not a major concern in Iceland. With a 0.2 percent adult relevancy rate, only 220 Icelanders are living with the disease. HIV/AIDS has proved fatal to around 100 people. When the Askja volcano erupted in 1873, it was a major economic and social catastrophe for Iceland. One in every five Icelanders died, and the country lost a fifth of its remaining population to Canada and the United States. Some scientists predict that Iceland will at some indefinite time be devastated by another volcanic eruption. Excavations of the graves of some of the 10,000 Icelanders who died in the 1873 eruption have provided scientists with new information on causes of death. Scores of Icelanders died from poisonous hydrofluoric acid that contaminated food and water sources or from illness brought on by extreme weather conditions that resulted from the eruption; the weather spread over parts of Europe. In an article published in the Journal of Geophysical Research in October 2004, two volcanologists predicted that a similar eruption is on its way and surmised that the aftermath would affect much of the Northern Hemisphere for months. Other volcanologists insist that the chance of a modern eruption that would threaten the health and well-being of Iceland and the surrounding area is low. SEE ALSO: Healthcare, Europe. Bibliography. Spencer Di Scala, Twentieth Century Eu-
rope: Politics, Society, Culture (McGraw-Hill, 2004); Sandra Halperin, War and Social Change in Modern Europe: The Great Transformation Revisited (Cambridge University
Press, 2004); Martin A. Levin and Martin Shapiro, eds., Transatlantic Policymaking in an Age of Austerity: Diversity and Drift (Georgetown University Press, 2004); Jeremy Rifkin, The European Dream: How Europe’s Vision of the Future Is Quietly Eclipsing the American Dream (Jeremy P. Tarcher/Penguin, 2004); Richard Stone, “Iceland’s Doomsday Scenario?” Science (v.306/5700, 2004); Peter TaylorGooby, New Risks, New Welfare: The Transformation of the European Welfare State (Oxford University Press, 2004). Elizabeth R. Purdy, Ph.D. Independent Scholar
Immune System and Disorders The immune system protects the body from invasion by nonself organisms with an array of tissues, cells and organs working together through primary and secondary mechanisms. The primary line of defense is physical and chemical barriers to keep out invaders. The skin forms a tough physical barrier and secretes oil and sweat as chemical defenses. Other chemical defenses are the acid secretions in the stomach and vagina, mucous secretions in the respiratory tract and lysozymes (antibacterial enzymes) in tears. Colonies of friendly bacteria live in the intestines to use up nutrients invaders could thrive on. The flushing action of urine removes invaders from the urinary tract. If an invader makes it past the first line of defense, a two-pronged secondary attack with nonspecific and specific responses is triggered into action. The nonspecific response is direct and immediate with chemical and cellular agents. The specific response is complex, specific to the invader and takes longer to prepare. The immune system recognizes the body’s cells because they carry specific markers for recognition under normal conditions as cells that belong. When the immune system agents encounter an unrecognized invader it triggers the immune response. To carry out the function of the immune system, organs throughout the body deploy lymphocytes (specialized white blood cells). The organs are often referred to as lymphoid organs and include the bone marrow, thymus, lymph nodes, spleen, tonsils, adenoids, appendix, lymphatic vessels to carry lymphocytes and Peyer’s patches clumps of lymphoid tissue in
the small intestine. Lymphocytes (B cells and T cells) and phagocytes, the cells which will become immune cells grow in the bone marrow. B cells mature in the bone marrow and T cells migrate to the thymus where they learn to distinguish self-cells from non-self invaders. Mature lymphocytes either collect in the immune tissue and organs or travel in lymphatic vessels throughout the body. Non-Specific Secondary Response Chemical nonspecific secondary response includes the release of histamine at the site of invasion to increase blood flow to the area and to increase the permeability of capillaries to allow other defense agents to enter. Kinins are released in the invaded area to increase inflammation and sensitivity and attract phagocytic white blood cells. Complement (plasma proteins) attacks the invader, penetrates the outer barrier and causes it to burst. Complement also may coat the surface of the invader to make it susceptible to phagocytic action. Interferon stimulates the inflammatory response and is antiviral by blocking synthesis of viral coat protein and halting viral cell growth. Cellular nonspecific secondary response includes the release of phagocytes (eosinophils, neutrophils, and monocytes which grow to macrophages at the site). The invader is trapped inside a vacuole and digested with powerful enzymes. Phagocytes are also destroyed and form pus at the site of infection. Natural killer cells are totally non-specific; they contain chemicals and kill invaders (tumor cells, pathogens, viruses and even the body’s own diseased cells) on contact by binding and then releasing the chemicals to make the cell membrane of the invader permeable causing it to burst. Specific Secondary Response Chemical specific secondary response includes the humoral response with the creation of specific antibodies. B-Lymphocytes (B-cells) make and secrete antibodies with a few acting as memory cells to ensure lasting immunity are produced in the bone marrow and in the fetal liver. Each lymphocyte is programmed to recognize only one specific antigen and yet B-lymphocytes can respond to millions of different antigens both naturally occurring and artificially created. T-lymphocytes are produced in the thymus and directly attack and destroy infected cells.
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When the body is exposed to an invading agent, helper T-cells (also known as CD4 cells) send a signal to the B-cells to initiate the humoral response and begin antibody production. The immune system utilizes B-cells to recognize and identify the invading agent. The B-cells produce and release antibodies through the humoral response and some B-cells commonly called memory-cells record and retain the information specific to the antigen to provide long-lasting protection against each specific invading agents. The Y-shaped antibodies have receptor binding sites that attach to the antigen or invading agent. Antibodies work in three similar though different ways; by binding to several antigens to form a clump to be devoured by phagocytes, by the complement system brings water into the cells causing the cells to burst and by opsonization coating the invading cells with antibodies with a constant region providing a receptor site matching a receptor on the phagocyte allowing the phagocyte to engulf and destroy the invading agent. Cellular specific secondary response is mediated by T-cells. Helper T-cells activate B cells, other T cells, natural killer cells and macrophages. Cytotoxic T-cells kill cells infected by viruses, cancer and are responsible for the rejection of tranplanted organs or tissues. Suppressor T-cells slow down and turn off the immune response. Memory T-cells record information to immediately recognize an invading agent if it shows up again in the body and trigger antibody production. Disorders of the Immune System When the body’s immune system fails to work properly, attacks the body’s own cells, is compromised by a chronic or acute disease state, the body is unable to keep up with the progression of the disease. Several disorders may result. Allergy is a hypersensitivity reaction to an invader with tissue inflammation and organ dysfunction. Because the allergen is foreign to the body, it often effects the organs with the first line of defense, the respiratory and digestive tracts. The allergic reaction may be atopic localized to a susceptible target, inherited development antigen-specific immunoglobulin to environmental or food allergens or it may be anaphylactic causing a general release of immune system mediators to certain allergens (drugs, foods, insect venoms)
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resulting in wide-spread immune response with vasodilation, itching, swelling, bronchospasm, and digestive tract or uterine muscle contractions. Cytotoxic reactions activate complement to destroy cells bound to antigens. Antigen-antibody complexes may deposit in tissues and are destroyed by the immune system causing tissue damage commonly affected organs are the skin, joints, and kidneys. Delayed hypersensitivity results from the deposit of antigen in tissues and when the immune system attacks the antigen, a later, localized inflammation occurs. Autoimmune disease occurs when the immune system attacks the body’s own tissues and create antibodies against its own cells. Common known or suspected diseases resulting from autoimmunity include arthritis, rheumatic fever, scleroderma, systemic lupus erythematosus, hormone disorders, and insulindependent diabetes mellitus. Nearly every tissue and organ in the body is susceptible to autoimmune attack. Autoimmunity may also occur after an infection with a disease organism with similar surface antigens to the body’s. The antigen may circulate in the body until the immune system recognizes the antigen as foreign. The specific antibodies then developed for these similar organisms may then in turn react with the body’s cells. Immunodeficiency diseases result from abnormalities in the immune system leading to increase susceptibility to infection, longer-lasting infection, or more severe infection. The immunodeficiency may be genentic or caused by external factors. Individuals with immunodeficiencies often succumb to infections. Genetically caused immunodeficiency diseases include X-linked agammaglobulinema (affects males where B-cells fail to mature into antibody producing cells), DiGeorge’s syndrome (thymus fails to develop resulting in suppressed T-cell response), and adenosine deaminase deficiency (absence of enzyme leads to death of B-cells and T-cells). A suppressed immune system caused by an external factor is AIDS. AIDS is caused by a retrovirus that attacks helper T-cells leading to a decrease in B-cell activity. The body is unable to form antibodies and becomes susceptible to attack from numerous rare diseases and opportunistic infections. Cancers of the immune system, as in other organs and cells of the body, result from the proliferation of cells in the organ. Cancers of the immune system
include leukemia (malignancy of the white blood cells replacing normal bone marrow elements), multiple myeloma (malignancy of plasma cells with replacement of the bone marrow leading to anemia and bone marrow and bone destruction) and nonHodgkin’s lymphomas (malignancy of T-cells and Bcells within the lymph nodes) and Hodgkin’s disease (Reed-Sternberg cells, arises in one lymph node and spreads to others). Special Immune System Considerations The recognition of self versus non-self invaders can cause difficulties with organ and tissue transplants (the immune system will recognize the transplant as foreign and attempt to reject it), bone marrow transplants (graft vs. host disease where the T-cells from the donor attack and destroy the tissues of the recipient) and Rhesus antigen (a red blood cell surface antigen may cause hemolytic disease the second positive Rh factor fetus for a negative Rh factor mother). Immunosuppressive drugs are used to prevent rejection of transplants. Corticosteroids result in reduced inflammation. Cytotoxic drugs can inhibit T-cell and B-cell immunity and inflammation. Antimetabolites inhibit the proliferation of T-cells and B-cells and some prevent T-cell activation. Cyclosporine and tacrolimus inhibit T-cell response. Bone marrow can be cleansed of mature T-cells to prevent graft versus host disease with chemicals or monoclonal antibodies. Passive immunity for protecting fetuses from hemolytic disease caused by Rhesus factor by adminstering Rh immune globulin to Rh-negative mothers within 72 hours of birth of the first Rh-positive child to destroy Rh positive cells so the mother will not produce antibodies to the Rh-positive cells. Current Research and Global Implications Stimulating or suppressing the immune response to treat disease either by increasing the body’s own defense mechanisms, injecting specific immunologic proteins, creating abundant T-lymphocytes to destroy infected cells or genetically altering T-lymphocytes to recognize and destroy cancer cells when reinjected into the body has the potential to improve quality of life.
Immunization/Vaccination
Continued research on the function, stimulation and suppression of the immune system could decrease the disease states caused by immune system disorders, the development of new vaccines. The potential may exist to treat immune system disorders with immunesystem components to fight diseases such as cancer, AIDS, allergies, and autoimmune diseases. See Also: Acquired Immunity; Active Immunity; AIDS;
Autoimmune Diseases (General); Chronic Fatigue Syndrome; Diabetes Type I (Juvenile Diabetes); Guillian-Barr Syndrome; Immunization/Vaccination; Infectious Diseases (General); Lupus; Lymphatic Diseases; Multiple Sclerosis; Myasthenia Gravis; Passive Immunity; Rheumatoid Arthritis; Scleroderma. Bibliography. Allan R. Cook, ed., Immune System Dis-
orders Sourcebook (Omnigraphics, 1997); Jeffrey L. Kishiyama, and Daniel C. Adelman, “Allergic and Immunologic Disorders,” in Basic and Clinical Pharmacology (Appleton & Lange, 1998); Maya Pines, Arousing the Fury of the Immune System: New Ways to Boost the Body’s Defenses (Howard Hughes Medical Institute, 1998). Lyn Michaud Independent Scholar
Immunization/Vaccination Human beings are frequently infected with a variety of pathogens, including bacteria, viruses, fungi, and parasites. A vaccine is a preparation that, when administered, can provide protection against a particular infectious agent. The idea for a vaccine was borne of observations that once an individual had suffered a particular infectious ailment, that person was unlikely to contract that disease again. There are reports dating to 200 b.c. of individuals in India and China inoculating themselves and others with infected matter from those suffering with mild cases of smallpox. Much later, Edward Jenner observed that milkmaids who had come into contact with cowpox did not develop smallpox when exposed. He subsequently tested this observation by directly exposing individuals to the fluid from cowpox lesions and then challenging them with a controlled infectious exposure, or inocu-
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lation, of smallpox. His test subjects did not become ill with smallpox, providing preliminary validation of the concept of vaccination. Ultimately, vaccination seeks to expose the immune system to a weakened, killed, or fragment of a pathogen in a way that generates an immune response so that upon exposure to that actual pathogen there is a rapid removal of the pathogen. This rapid response ultimately will prevent spread of the invading organism from the portal of entry and would also prevent subsequent replication and disease manifestations. THE IMMUNE SYSTEM A basic understanding of the immune system helps to clarify the importance and problems inherent in vaccinations. When the body is exposed to a pathogen the body responds in several ways. There are components of the innate immune system that react to whatever pathogen gains entry into the body. The innate immune system reaction is rapid, but is nonspecific and confers no “memory” meaning that if the body is exposed to the same pathogen again the response is not faster nor stronger the second time. There are several cell types that are involved in the innate immune response including mast cells, neutrophils, basophils, eosinophils, dendritic cells, and neutrophils. While these cells all have specific functions, they have the capacity to kill a broad range of infecting organisms. Innate immunity is a more primitive response, and there are similar defense mechanisms in not only humans, but all plant and animal life. In contrast, the adaptive immune system is composed of several different cell types, including B cells which are responsible for making antibodies. Antibodies recognize specific features of an infectious organism, and by binding, can promote the sequestration, removal or engulfment of that pathogen. Tcells can help direct the immune system and can also directly kill cells of the body that are infected with a pathogen. It takes longer for the adaptive immune system to respond to an infectious agent. However, upon exposure to a bacteria or virus there is concurrently the process of eliminating the offending agent and also the development of “memory” cells. These memory cells, both B and T-cells, have been exposed to a particular infectious agent so that upon a second exposure there is a more rapid and specific response that can clear the body of that particular infection
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Immunization/Vaccination late an immune response. Alternatively, vaccination can be accomplished by exposing an individual to a similar and related infectious organism that does not cause disease but can generate cross-immunity.
A vaccine is a preparation that, when administered, can provide protection against a particular infectious agent.
before it has a chance to cause disease. Oftentimes there is a cumulative response, in that a single exposure does provide some level of memory and protection, but multiple exposures are needed to develop a high level of immunity. The process of immunization takes advantage of the ability of the immune system to remember an infection and become more prepared to clear a subsequent infection. ACTIVE IMMUNIZATION Immunizations are frequently divided into two types: active and passive immunization. Active immunization takes into account the properties of the adaptive immune system described above. The goal of an active immunization is to stimulate a response in the immune system by exposing the body to a particular infectious agent. There are several different vaccine preparations that exist. For both bacteria and viruses, often the whole organism that has been killed will be used as the vaccine. Other times, an attenuated, or weakened, form of a bacteria or virus can be used. These attenuated vaccines are recognized by the immune system as foreign and the immune system generates a response against them, but the pathogens themselves are not capable of causing disease. Other times, the vaccine will contain only a fragment, subunit, or protein component of a particular bacteria or virus. Lastly, some pathogens do not cause damage to humans themselves, but rather they secrete toxins that can cause disease. Some vaccines use modified versions of those toxins to stimu-
PASSIVE IMMUNIZATION Passive immunization is used when there is a need to provide short-term and rapid protection against a particular infection and there is not time to administer an immunization and await the development of the stronger, memory immune response or in an individual that is immunocompromised and unable to mount a sufficient response on his or her own. Passive immunity involves administration of antibodies taken from human serum and transfusing it into the individual who has been exposed to the specific pathogen. This method of vaccination is not part of routine disease prevention. VACCINE AVAILABIliTY There are several factors that influence whether or not a vaccine is available for a particular bacteria or virus. For some organisms, the lifecycle and the components of a successful immune response are not known, precluding the successful development of a vaccine. In other cases, the pathogen has developed mechanisms to evade the immune system and may mutate rapidly, may change the surface proteins, or use other techniques such that each time the immune system encounters it, the appearance is different and memory cells are not able to respond appropriately. For example, while HIV is very well studied, it mutates rapidly making it difficult to develop a successful vaccine. There are other factors that influence whether a particular vaccine is available on a global market, including storage requirements, such as need for refrigeration or a need for sterile syringes. In addition, the cost of some vaccines makes wide distribution unrealistic. For example, a vaccine against human papillomavirus was recently developed; however, the price is sufficiently prohibitive, and it is not widely available. There are a number of infectious agents for which vaccines are available, including hepatitis A, hepatitis B, Poliovirus, yellow fever, influenza virus, diphtheria, haemophilus influenzae, measles, mumps, pertussis, rubella, tetanus, varicella, smallpox, tu-
Immunologist
berculosis, human papillomavirus, meningococcus, rotavirus and others. Many countries have mandated certain vaccines for entry into the school system or travel into the country. Mass vaccinations have led to the elimination of smallpox worldwide, and the near-eradication of polio. In addition, in areas with a large percentage of the population receiving vaccinations (herd immunity) there have been significant decreases in infections such as measles, mumps, rubella, haemophilus influenzae and others. Increased global access to vaccination and primary health services will further reduce the global burden of infectious disease. See also: Acquired Immunity; Active Immunity; Immu-
nology; Infectious Diseases (General); Innate Immunity.
Bibliography. Allan R. Cook, ed., Immune System Disor-
ders Sourcebook (Omnigraphics Inc, 1997); Catherine J.M. Diodati, Immunization: History, Ethics, Law and Health (Integral Aspects, 1999). Christine Curry Independent Scholar
Immunologist Immunologists are people working in the biomedical field of immunology studying the immune systems of biological organisms from a variety of perspectives including the investigation of molecular structure and function, and evolutionary, clinical, diagnostic, and therapeutic angles. They examine the relationships between pathogens, immune responses, and the environment in the field of host defense. Immunologists may be medical specialists trained in the field of immunology, physician-scientists, or research scientists. The work of immunologists intersects with professionals in many other fields such as rheumatology, infectious disease, hematology, and organ transplantation. At the nexus of the study and practice of immunology lies the study of epidemiology, which informs the transmission course of and adaptation to disease. The historical origins of immunology can be traced back to at least 430 b.c.e. when Thucydides recorded the plague in Athens. In many ways, he became a fore-
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runner for future immunologists. He described in his writings that many people who recovered from the illness could care for the sick without contracting the plague for a second time. The next pivotal moment in the history of immunologists occurred centuries later. In 1796, Edward Jenner, a doctor in England, introduced the concept of vaccination immunity using cowpox to provide cross-immunity for smallpox in humans. A scientific approach to the study of immunology developed later in the 19th and 20th centuries. Louis Pasteur furthered concepts used by Jenner and contributed to the fields of bacteriology and immunity through studies of cholera, rabies, and anthrax. The experimental work of Pasteur and Robert Koch in the 19th century cemented the foundation of germ theory (i.e., the notion that diseases are caused by pathogens) intricate to the understanding of immunology. Shibasaburo Kitasato and Emil von Behring provided the ground for understanding antibodies and immunity in the late 1890s through their studies of animals immune to tetanus and diphtheria, diseases caused by organisms that produce toxins harmful to their host. Many Nobel laureates and scientists of the 20th century have made seminal contributions to the evolution of field of immunology. For example, Jules Bordet provided evidence about the existence and role of the complement system in the immune response. Karl Landsteiner developed a classification system for blood groups intricate to the understanding of blood transfusion science. Gerald Edelman and Rodney Porter discovered the exact chemical structure of an antibody protein and were awarded a Nobel Prize in 1972 for their work. Edward Thomas and Joseph Murray received a Nobel Prize in 1990 for their important contributions to cell and organ transplantation in treating human disease, notably leukemia. Increasing scientific knowledge and rapid technological growth in the 21st century increasingly provides immunologists an opportunity for a deeper understanding of the function, adaptation, and behavior of the immune system. Advances in the characterization and treatment of autoimmune disorders and inflammatory processes, better donor–recipient matching and rejection prevention in allograft cell and organ transplantation, and new developments in genomic medicine for individualized patient treatment for a variety of autoimmune and pathogenic diseases are
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current areas of exciting growth in the field of immunology. Gene therapies remain in their infancy in the treatment of a variety of immune disorders, but they hold an amazing therapeutic potential. An increasing understanding of the complexities in immune signaling pathways is allowing immunologists to create a rapidly evolving landscape of options in the diagnosis and treatment of acquired infections, cancers, autoimmune diseases, and organ transplantations. SEE ALSO: Allergy; Bacteriology; Bone Marrow Diseases;
Immune System and Disorders; Immunization/Vaccination; Immunology; Immunosuppression; Immunotherapy; Organ Transplantation; Pasteur, Louis; Psychoimmunology; Psychoneuroimmunology; Virology. Bibliography. Charles Janeway, Immunobiology: The Im-
mune System in Health and Disease (Garland, 2005); Arthur Silverstein, A History of Immunology (Academic Press, 1989). Justin M. List, M.A.R. Stritch School of Medicine Loyola University Chicago
Immunology In the late 18th century Dr. Edward Jenner stumbled upon the notion of the immune system following his discovery that cowpox protected him against a human pathogen known as smallpox. This process of immunity by introduction of more mild strains of a disease became known as vaccination. Unfortunately, very little was understood about the etiology of infection and the subsequent induction of the host immune response. Dr. Robert Koch, over 100 years later, established the first relationship between cause and effect as it relates to infection. Out of his work came specific postulates used to understand which pathogens are fundamentally responsible for specific diseases and what components of those pathogens contribute to disease progression. The concept of immunology was born. Immunology is the study of the immune system, the primary defense mechanism of the body. In humans, the immune system is composed of specific immune cells and produces and utilizes numerous
unique, chemical signals. Each component of the immune system works collectively to prevent invasion by foreign substances, or pathogens. Examples of such pathogens include bacteria, viruses, fungi, and parasites. Each utilizes a specific method of transmission such as fecal-oral, airborne, direct inoculation, direct contact, and congenital. To elicit an immune response, these pathogens must not only be foreign to the body, but they must be large enough molecules, chemically complex, and degradable. Still heavily studied area, the human immune system consists of both innate and acquired responses to pathogenic invasion with both types of responses interacting on many complex, biological levels. Typical components of the innate immune system include normal physiologic and chemical barriers such as the skin, saliva, the pH of the stomach, tears, enzymes, and mucous. During the innate response, the human body utilizes immune cells such as neutrophils, monocytes, NK cells, and tissue macrophages. These cells respond to specific foreign patterns through preexisting pattern recognition receptors. Each type of cell has the ability to kill the invading organism through a nonspecific process known as phagocytosis, a mechanism first discovered by the Russian immunologist Dr. Elie Metchnikoff. This process includes engulfment of the pathogen and fusion with acidic enzymes within the host cell. Innate immune cells can also kill through the complement cascade as well as extracellular mechanisms involving soluble mediators. Complement activation includes first lysing the pathogens, and then coating them with a material targeting them for phagocytosis. Complement involves the following three pathways: classical, alternative, and lectin binding. All converge on a common pathway where a pore is created within the target cell membrane leading to lysis of that cell. In innate immunity, the characteristic immune response includes chemical messages in the form of cytokines, pyrogens (fever producers), interferon, and complement. While innate immunity is an effective means of fighting off foreign bodies, it is sometimes not enough. Thankfully, our bodies possess another type of immunity known as acquired immunity. Acquired, or adaptive immunity, can be divided into humoral and cell mediated immunity. The response time is much slower when compared with innate immunity. Both humoral and cell-mediated responses
Immunosuppression
depend on specific cells known as B and T cells which develop and mature in the primary lymphoid organs of the bone marrow and thymus gland, respectively. Following maturation, these cells leave the primary lymphoid organs and move to secondary lymphoid organs, which include the spleen, lymph nodes, and tonsils. B cells recognize intact pathogen, whereas T cells only recognize pathogen that has been broken down into protein components and presented on the cell surface of another immune cell. B cells communicate with other cells through a specific receptor, whereas T cells must bind using a receptor and an additional cell surface molecule known as the MHC. There are two important types of T cells, CD8 and CD4, and each binds to a specific set of cell surface molecules. Already armed with a set level of specificity for an invading pathogen, B and T cells are induced to proliferate once they encounter pathogen so that the population of immune cells with identical specificity for a pathogen increases. This increases the potential for specific destruction and containment of the foreign organism. This proliferation, or clonal expansion of cells, in response to the first encounter with pathogen is considered the primary response, and it is soon followed by a more rapid and larger secondary response when the immune system encounters the same pathogen again. This secondary response includes memory B and T cells which contribute to the faster nature of this response. It is during this secondary response that the different functional capacities of B and T cells are revealed. B cells will differentiate into plasma cells, which will secrete antibodies, or immunoglobulins. There are five different groups of immunoglobulins each with distinct functions and biologic properties: IgG, IgM, IgE, IgD, and IgA. These antibodies are specific for antigens found on the pathogens. Antigens, or any foreign substance recognized by a specific receptor, can include the following: proteins, carbohydrates, lipids, or nucleic acids considered foreign to the body. Once T cells encounter pathogen a second time they also possess the capacity to become memory cells. They function as either helper T cells or cytotoxic T cells both of which play integral roles in pathogenic destruction and induction of the host immune response. Immunology utilizes many tests to determine the presence or absence or antibodies or antigens. These
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include radioimmunoassay (RIA), enzyme-linked immunosorbent assay (ELISA), direct immunofluoresence, monoclonal antibody production, and Western blotting. Our understanding of the process of immunology is crucial, for it allows further exploration into disease prevention, leads to the discovery of vaccines, offers insight into effective and successful methods to fight infection, and uncovers the intricate mechanisms involved in the immune response to pathogenic invasion. Maybe the most important of all of the benefits to our understanding of immunology lies in the ability to improve quality of life and to evade death. SEE ALSO: Acquired Immunity; Immunologist; Innate
Immunity.
Bibliography. Charles Janeway, Paul Travers, and Mark
Walport, Immunobiology, the Immune System in Health and Disease (Elsevier Science Ltd./Garland Publishing 1999); Ian Todd, and Gavin Spickett, Immunology (Blackwell Publishing, 2005). Melissa K. Wolinski Michigan State University
Immunosuppression Immunosuppression is a natural act or medical treatment that reduces the activation or efficacy of the natural immune system in humans and animals. Generally, immunosuppression is a result of viral activity (such as human immunodeficiency virus [HIV]) or other natural causes. In some cases, immunosuppression is an unwanted side effect of treatment for particular diseases or conditions. In recent years, this process been very important in allowing people to accept transplants such as kidneys which might otherwise be rejected by the natural immunities of the patient. There have long been particular conditions that lower the response of the human immune system, with the most wellknown in recent years being HIV. In fact, suffering from many illnesses and medical conditions may weaken a person, and as a result, lower the activation of their immune system, making them
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more susceptible to other illnesses or diseases. This phenomenon has been observed since ancient times. Often, when someone is suffering from a particular condition, others with any type of potentially infectious disease—even the common cold—are prevented from visiting to help ensure that the patient avoids additional illnesses, an even made more possible due to the patient’s compromised immune system. Additionally, some diseases and conditions are best treated by methods that can further reduce or compromise the patient’s immune system. For this reason, people who are having or have recently had treatment by chemotherapy are often advised not to visit friends or relatives in hospitals; as their immune system has been suppressed by treatment, exposure to other conditions may result in infection or additional serious complications. The immune system often reacts to the transplantation of new organs by attempting to reject the organ as if it were an infection or disease. For this reason, the recipient is often treated with immunosuppressive drugs. The first of these to be identified was cortisone, but it had many side effects that limited its use. In 1959, azathiprine was produced and found to be far more specific in its treatment of organ donor recipients. The discovery of cyclosporine in 1970 as an effective immunosuppressive drug changed the nature of kidney transplantation, allowing it to become a far more common practice for using organs from donors who did not perfectly matched those of recipients. Since then, this drug has been used successfully for liver transplants, lung transplants, pancreas transplants, and heart transplants. Some of the pioneering research in the field of immunosuppression was conducted by Dr. Joseph E. Murray, professor of surgery at Harvard Medical School since 1970, who was the chief plastic surgeon at the Children’s Hospital, Boston, from 1972 until 1985. In 1990, he was awarded the Nobel Prize in Physiology or Medicine for his work; Dr. Murray and his team were credited with the first successful kidney transplant, which took place at Peter Bent Brigham Hospital in Boston on December 23, 1954. Eight years later, he conducted the first kidney transplant with a kidney from a donor unrelated to the patient; immunosuppressive drugs were key to the success of the operation. SEE ALSO: Organ Transplantation.
Bibliography. Steven A. Frank, Immunology and Evo-
lution of Infectious Disease (Princeton University Press, 2002); Janis Kuby, Immunology (W. H. Freeman, 2003). Justin Corfield Geelong Grammar School, Australia
Immunotherapy The immune system, through a variety of responses working together, protects the body from invading pathogens and eliminates disease. When the body’s immune system fails to work properly or is compromised by a chronic or acute disease, the body is unable to keep up with the progression of the disease and needs additional help to fight off debilitating effects. Providing passive immunity is one of the most widely recognized and used forms of immunotherapy. This process transfers immunity by direct injection of antibodies or antiserum to prevent infectious disease. This provides immediate—though temporary—protection from a specific disease-causing bacteria, virus, or toxin and can also protect persons unable to produce antibodies themselves. These injected antibodies have a short lifespan. No memory cells are created leaving the individual is left susceptible to infection by the same antigen. Any immunotherapy, whether classified as investigational or approved for use, relies on stimulating the immune response to treat a disease either by increasing the body’s own defense mechanisms, injecting specific immunologic proteins, creating abundant T-lymphocytes to destroy infected cells, or genetically altering T-lymphocytes to recognize and destroy cancer cells when reinjected into the body. According to the American Cancer Society, immunotherapy is used to enhance the primary treatment. Immunotherapy relies on activating a portion of the immune system through the use of proteins or medications to improve immune function. An approved use of BCG (an extract of weakened tuberculosis) has been effective in treating bladder cancer by increasing production of T-lymphocytes. Levamisole is approved as an adjunct to fluorouracil for colon cancer to increase macrophage activity.
Impetigo
The discovery of cytokines, a large diverse group of proteins functioning and released by various cells of the immune system has led to numerous uses of specific cytokines for treating infections, inflammations, autoimmune disorders, and neoplasms. The approved uses of cytokines include interferon–alpha for the treatment of two forms of leukemia, malignant melanoma, and Kaposi’s sarcoma; interferon–beta for treating relapsing multiple sclerosis; interferon–gamma for treating chronic granulomatous disease; and interleukin–2 for treating metastatic renal cell carcinoma. Research continues into numerous uses of cytokines for immunotherapy. Other forms of immunotherapy are still being investigated. Gene therapy is being tested as a way to remove melanoma tumors throughout the body. Researchers are experimenting with isolating white blood cells and inserting T-lymphocyte receptors to recognize and destroy cancer. When reinjected into the body, these altered cells seek out and destroy specific cancer cells throughout the body. Another possible use for immunotherapy is in HIV infection. The HIV virus destroys helper T-lymphocytes. These cells are important to modulating the immune response. When these cells are destroyed, the entire immune system becomes compromised. T-lymphocytes, the so-called natural killer cells exist in the blood; some have the specificity to seek out and destroy HIV. Theoretically, a patient could have blood drawn, and, in a laboratory environment, have the number of these HIV-specific T-lymphocytes created using a polymerase chain reaction (PCR). These could then be injected back into the patient to assist in fighting disease. In theory, the purpose of treating the immune system with immune-system components increases the body’s ability to fight diseases such as cancer, AIDS, allergies, and autoimmune diseases. In these conditions, the body fails to recognize its own cells and the immune system begins to automatically destroy those cells. With some success, immunotherapy has attracted attention from governments and academic researchers. While currently being used effectively for some forms of cancer and allergies, failures have occurred as well. There is hope that immunotherapy can be used for other diseases and to prevent rejection of transplanted organs.
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SEE ALSO: Acquired Immunity; Active Immunity; Allergy;
Cancer Alternative Therapy; Immune System and Disorders; Passive Immunity. Bibliography. Jose Alexandre M. Barbuto, Emmanuel T.
Akporiaye, and Evean M. Hersch, “Immunopharmacology,” in Basic and Clinical Pharmacology (Appleton & Lange, 1998); Merck Manual of Medical Information, 2nd home ed. (Merck Research Laboratories, 2003); New Ways to Boost the Body’s Defenses Arousing the Fury of the Immune System (Howard Hughes Medical Institute, 1998); “What Is Immunotherapy?” www.cancer.org (cited April 2005). Lyn Michaud Independent Scholar
Impetigo Impetigo is a superficial skin disease that is usually found in children between 2 and 6 years old as well as older people who play close contact sports such as American football, rugby, and wrestling. The name impetigo derives from the Latin impetere (“assail”) because it often results from these contact sports. It is sometimes commonly known as “school sores.” The most common form of impetigo starts as an inflamed region of skin about half an inch in diameter. The incubation period of the infection is between one and three days and is indicated by the appearance of pimple-like lesions with the skin around these lesions turning red. The lesions then fill with pus that breaks down over the next four to six days and forms a thick crust. The main cause of impetigo is from the streptoccocus strain known as Streptoccocus pyogenes, which also causes strep throat; impetigo can also be caused by Staphylococcus aureus. The infection is initially spread by lesions or with nasal carriers and cannot be carried by dead streptococci in the air. Impetigo often occurs alongside other injuries to the skin such as insect bites and cuts, which can make it difficult to diagnose correctly. Aside from examination, the most common method of discovery of impetigo is in the form of itchy skin. Patients with a history of cold sores are statistically more likely to have infections of impetigo.
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Treatment of impetigo depends on the type of skin lesion that appears and the age of the infected person. At its simplest, treatment can involve washing the affected areas with soap and water or using diluted tea tree oil with an inert carrier oil. Many general practitioners recommend the use of bactericidal ointment and, in more severe cases, the use of oral antibiotics. In all cases, it is important to dissolve the skin scabs with ointment, as the bacteria that causes impetigo lives underneath the scabs. The tea tree oil solution is an exception to this rule, as this solution is generally capable of penetrating the scab. Once treated, impetigo usually clears up in three to five days. SEE ALSO: Skin Diseases; Staphlococcal Infections; Strep-
tococcal Infections.
Bibliography. Wayne Biddle, Field Guide to Germs
(Henry Holt, 2002); Prisca Middlemiss, What’s that Rash? How to Identify and Treat Childhood Rashes (Hamlyn, 2002); Carol Turkington, Encyclopedia of Skin and Skin Disorders (Facts on File, 2002); David Weeden, Skin Pathology (Harcourt, 2002). Justin Corfield Geelong Grammar School, Australia
Impotence Impotence, often called erectile dysfunction (ED) when discussed in a biomedical context, is the inability to sustain a penile erection sufficient for satisfactory sexual intercourse. An estimated 15 to 30 million men worldwide suffer from some degree of this condition; more prevalent among older men, younger men are also vulnerable to ED. While biomedical treatments for ED, like Viagra , have become popular worldwide, the causes of this condition can be physical and psychological, and are often a mixture of both. Although the majority of cases of ED can be treated pharmacologically, the causes of each case are unique to the individual sufferer. Further, the practical understanding of what kind of sexual performance constitutes ED or impotence varies according to culture and location, since individual ideas about what constitutes “satisfactory” sex vary according to these factors. Ideas
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about the causes of ED or impotence vary similarly; depending on the particular healing systems to which individual men subscribe, elements as diverse as poor blood flow and witchcraft may be viewed as etiological factors. In the biomedical view, ED is caused by physical factors that impede blood flow to the penis; these include noncommunicable diseases (NCDs) like type 2 diabetes and heart disease, and nerve damage, often caused by spinal cord injury, prostate surgery, or degenerative nerve disease. ED is compounded, and in some cases caused, by emotional factors including stress, depression, and interpersonal disharmony. Impotence in Non-Western Cultures Less-than-ideal erections have long been seen as a concern worldwide, although different cultures hold different ideals of sexual performance and understand erectile difficulty to be caused and cured by different factors. In China, for instance, traditional medicine has dealt with impotence for over 2,000 years. Chinese traditional medicine understands impotence as a problem resulting from a bodily energy blockage located in the liver or kidney; this condition is treated with herbal medicine and acupuncture. In many cultures, such as that of the Azande of north central Africa, illness is believed to be caused by the intervention of malevolent spirits; the cause of impotence is thought to be witchcraft, and the condition is treated by counteracting the witch. The herbal treatment of impotence, as well as ideas of erectile difficulty caused by spirit intervention, coexist in many areas with the use of pharmaceutical treatments for ED. Recent History of Impotence in the West Ideas about the causes and nature of impotence have changed dramatically in western societies over the past century. At the turn of the 19th century, persistent impotence was understood as a medical problem, but one with behavioral roots. Too much sex, masturbation, or “perverse”(other than heterosexual, procreative) sex were thought to physically damage the penis and deplete what was thought to be a limited supply of energy-giving sperm. Impotence was treated with behavioral change, specifically warnings to reduce sexual activity and perform only heterosexual, traditional sexual acts. Behavioral treatment was often accompanied with medical treatment, such as surgical treatment for
Impotence
urethral strictures to address the physical damage that doctors thought was caused by excessive sex. As psychoanalysis, Sigmund Freud’s theory of the unconscious and the treatment of neuroses, became popular in the first half of the 20th century, impotence came to be seen as a symptom of underlying psychological problems. With the popularity of psychoanalysis, sexuality became to be commonly seen as a natural drive, albeit one that could be expressed incorrectly in individuals suffering from childhood trauma. Thus, the treatment for impotence was no longer behavioral change but participation in a psychoanalytic talking cure designed to uncover trauma and set sexual development on a healthy path. Psychoanalysis fell out of favor in the latter half of the 20th century, and biomedical explanations for physical conditions previously thought to be caused by psychological problems have since been adopted. Sexual response has come to be understood as a largely biological issue, although one that could be affected by emotions. From this, impotence came to be understood as a largely biological pathology. The development of biomedical treatments for impotence, beginning with sale of the penile implant in 1973, cemented this view. The penile vacuum pump, introduced in 1983, and the pharmacological remedies of injectible papaverine (1995) and similarly acting urethral suppositories (1997) followed. While these biomedical interventions never became widely popular due to the difficulty and discomfort of their use, their existence helped to support and spread the idea that nonnormative erections are a biomedically treatable problem. From Impotence to Erectile Dysfunction The current popularity of thinking about, and treating, less-than-ideal erections as a biomedical problem is largely due to two factors: the clear redefinition of impotence as a medical issue and the introduction of noninvasive pharmaceutical interventions for impotence. Because the concept of “impotence” connoted weak masculinity, in the early 1990s health professionals and pharmaceutical companies sought to destigmatize less-than-ideal erections by clearly redefining them as a disease condition; they accomplished this by terming impotence “erectile dysfunction.” This reconceptualization went hand-in-hand
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with a new and more appealing treatment option: Viagra. While earlier medical treatments were cumbersome and uncomfortable, Viagra (sildenafil) is a pill. The drug was introduced by Pfizer in 1998, and it revolutionized the medical treatment of ED. Viagra was introduced simultaneously in multiple countries, and was soon available (if sometimes via smuggling, internet pharmacy, or “Viagra tourism”) worldwide. Viagra, a vasodilator, works by enlarging penile blood vessels to increase blood flow, which in turn causes an erection. This drug was followed in 2003 by Eli Lilly Icos’ Cialis (tadalafil) and in 2005 by Bayer’s Levitra (vardenafil), which work in essentially the same way as Viagra. With the advent and global sale of these medications, the idea of nonnormative erections as a biomedical problem has spread worldwide. The popularization of the ED model for understanding nonnormative erections has helped to destigmatize and provide medical assistance for the condition, bringing relief to millions of men. However, the global spread of this sort of understanding has also been critiqued. Studies of couples in which men have begun to use Viagra have revealed that women are often unhappy with the new focus on penetrative sexuality that Viagra may induce, and sexologists have argued that the focus on restoring normative erectile function limits human sexuality and enforces traditional gender roles. Critics of medicalization have voiced the concern that the medicalization of aging, including age-related changes in erectile function, makes individuals unhappy with their natural bodies and dependent on costly and unnecessary drugs.
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Impotence and Chronic Disease Medical studies report that ED is increasing at epidemic rates across the globe. While this is due in part to growing understandings of nonnormative erections as cases of ED, problems with erectile function are also increasing as a symptom of the global epidemic of NCD. Developed nations have gone through an “epidemiologic transition” in which the leading causes of morbidity shift from infectious disease and injury to chronic NCDs like cancer, diabetes, and heart disease. As people in developing nations adopt processed-food, heavy Western diets, and sedentary lifestyles, NCDs have become a global epidemic and significant cause of global morbidity. ED is a symptom of many NCDs, like type 2 diabetes and heart
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disease, which impede blood flow. Thus, as NCDs have increased, so has the occurrence of ED. Public health campaigns, as well as pharmaceutical marketing, have begun to make use of the link between ED and NCDs to encourage men to seek medical help and make healthful lifestyle changes. Men who do not see their doctors for treatment of NCDs may be encouraged to do so by the fear or experience of ED. Thus, a growing number of public health interventions aimed at preventing or treating NCDs make use of ED treatment as a way to draw men to healthcare providers. SEE ALSO: American Urological Association (AUA); Diabe-
tes Type II; Heart Diseases (General); Male Genital Disorders; Prostate Cancer; Reproductive Health (General). Bibliography. Andrew S. Crimmel, Chad S. Conner, and
Manoj Monga, “Withered Yang: A Review of Traditional Chinese Medical Treatment of Male Infertility and Erectile Dysfunction,” Journal of Andrology (v.22/2, 2001); Ian Eardley and Sethia Krishna, Erectile Dysfunction: Current Investigation and Management (Mosby, 2003); Maud Kamatenesi-Mugisha and Hannington Oryem-Origa, “Traditional Herbal Remedies Used in the Management of Sexual Impotence and Erectile Dysfunction in Western Uganda,” African Health Sciences (v.5/1, 2005); Annie Potts, et al., “’Viagra Stories’: Challenging “Erectile Dysfunction,” Social Science & Medicine (v.59, 2003); Leonore Tiefer, “The Medicalization of Impotence: Normalizing Phallocentrism,” Gender & Society (v.8/3, 1994). Emily Wentzell University of Michigan
In Situ The term in situ comes from the Latin and means “in the/its place.” In biology, the term usually refers to the study of an organism where it naturally occurs, such as in arid and desert conditions or at the bottom of deep ocean troughs, rather than how the organism reacts in a laboratory. In medical research, in situ research means studying the way people interact with their normal work or home environment to discover the potential sources of the various problems or dis-
orders that may and do occur. This is particularly important when working out causes of problems based on occupational or residential factors, such as working in a place with regular exposure to radiation or living in a house that has major environmental problems such as dampness or pollution. The study of problems in workplace environments has led to medical researchers developing the concept of occupational cancer, first developed by the British surgeon Sir Percivall Pott who, in 1775, made the discovery of the link between scrotal cancer in chimney sweeps with their regular exposure to soot. The term in situ when used by oncologists usually refers to the study of malignant cancer cells in their location within a person rather than isolated on a petri dish or in a test tube. It can also be used to describe a carcinoma to refer to malignant cells that are present in the epithelium which have not been invaded beyond the basal lamina into deeper tissues. This is particularly important for developing techniques, including laser surgery. Bladder cancer at stage 0 is called a carcinoma in situ while it remains localized in the inner layer of the urinary bladder; however, as soon as it spreads, it is said to be no longer in situ. Similarly, while a stomach cancer carcinoma is only affecting the stomach, it is known as being in situ. Geneticists have used the term in situ meaning “in the chromosome.” An example of this is “fluorescent in situ hybridization,” abbreviated as “FISH,” which can happen to chromosomes in cells when a target sequence is being observed. SEE ALSO: Oncology. Bibliography. K. H. Choo, ed., In Situ Hybridization Pro-
tocols, Vol. 33 ( Springer-Verlag, 1994); Bruce E. Rittmann, et al., In Situ Bioremediation (Noyes Publications, 1994). Justin Corfield Geelong Grammar School, Australia
In Vitro The strict translation of in vitro from Latin is “in glass.” Historically, in vitro studies were carried out in glass containers (test tubes, beakers). Now, in vitro
research refers to research performed in an artificial environment and refers to experiments in culture media, petri dishes, or other controlled environments outside of living organisms. In vitro research is common to formal laboratory settings. Because of the controlled environment, there are typically fewer variables and results are easier to distinguish. An advantage of this type of research is the ability to focus on specific component parts of organisms and how they function. Often, in vitro research is centered on one modification and the subsequent reaction upon the specific cellular component being tested. For example, in vitro studies could be used to discern function of specific enzymes and receptors. In addition, in vitro research is typically less expensive to perform and yields results that can be extended into different fields of technology. Initial pharmaceutical research is typically done in vitro, as metabolic pathways are better defined and the mechanism of action delineated. This background is necessary prior to the creation of new medications. One current use of in vitro technology is in vitro fertilization (IVF). Infertility is typically defined as inability to conceive within 12 months of unprotected intercourse. Couples with certain types of infertility have achieved pregnancy using this technique. Specifically, a patient’s ovaries are stimulated with a particular hormone to cause ovulation and maturation of eggs. Then, the eggs are surgically retrieved and fertilized with sperm in an in vitro laboratory setting, typically in petri dishes. The fertilized eggs become zygotes and typically, when they develop into six- to eight-cell embryos (approximately two to three days later), they are then transferred to the patient’s uterus with the intent to progress to a successful pregnancy. Potential risks of IVF may include difficulties with the medication to initially stimulate the ovaries (resulting in either lack of ovulation or ovarian hyperstimulation syndrome), operative risks in obtaining the eggs or transferring the embryos, lack of adequate fertilization or progression to viable embryos, multiple gestations, other complications of pregnancy, and psychological stress. Additionally, the several-step procedure of IVF is expensive, and may be cost prohibitive to some couples, as insurance coverage for the management of infertility varies between different carriers and different states.
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In vitro fertilization (IVF) has enabled couples with certain types of infertility to achieve pregnancy through this method.
The controlled environment of in vitro studies is sometimes a disadvantage when drawing conclusions as to how living organisms will respond with the same modification. Because living organisms may have multiple other adaptations related to the experimental change, sometimes results of in vitro studies are not only inaccurate, but they can be completely unpredictable. In fact, over time, uses of pharmaceuticals tested in vitro can change dramatically over time. A recent prominent example of this is aspirin. Initially, the synthetic drug was used as an analgesic. For the 100 years following its discovery, its uses increased and in the last 30 years aspirin has been recognized to reduce the risk of all vascular events (myocardial infarction, stroke, and deep vein thromboses) by about one-third. Therefore, results from studies performed in vitro do not always show precisely how living organisms will respond; because of this it may be difficult to draw conclusions from in vitro studies directly to living organisms and to how they actually respond internally.
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SEE ALSO: Hormones; In Vivo; Infertility. Bibliography. Peter Elwood and Michael Stillings, “As-
pirin—The First Miracle Drug,” The Pharmaceutical Journal (v.266/7138, 2001); Emily C. Harrison and Julie Scott Taylor, “IVF Therapy for Unexplained Infertility,” American Family Physician (v.73/1, 2006); Illustrated Stedman’s Medical Dictionary, 24th ed. (Williams & Wilkins, 1982); Wikepedia, “In Vitro,” http://en.wikipedia.org/wiki/In_vitro (cited February 22, 2007); Wikepedia, “In Vitro Fertilisation,” http://en.wikipedia.org/wiki/In_vitro_fertilization (cited February 22, 2007). Ann M. Karty, M.D. Kansas City University of Medicine and Biosciences
In Vivo The literal translation of in vivo from Latin is “in the living being.” This phrase refers to those things occurring inside of a living entity. In vivo research refers to research performed within the tissue of a living being as opposed to research performed on dead materials or on specific metabolic components. In vivo research is commonly used to observe the overall effects on the living organism being studied rather than one specific outcome. Accordingly, there are more external variables with in vivo research. Although optimal studies attempt to limit outside factors potentially confounding the project, results of studies are sometimes difficult to determine because there may be factors (both predicted and not predicted) that alter results or factors that alter the specific interpretation of results. In vivo research, by definition, must be performed within the system in which it is meant to be used. New pharmaceuticals and compounds created in laboratories may prove worthless or even harmful to living tissue, and thus must be tested on live subjects. Live organisms used for these tests can vary from plants to mice to human subjects. The value of in vivo testing is revealed in cases where, for instance, a substance that has been found to be active and effective in laboratory, in vitro tests virtually disappear when tested in vivo;
this can happen because of the interaction of another in vivo factor that interacts negatively with the substance being tested. In vivo research is generally conducted by pharmaceutical companies when testing new drugs; often, these in vivo trials involve human subjects. Typically, background research on the potential pharmaceutical being tested has already been conducted on individual metabolic components, and an intervention has been created to treat a medical condition. In the United States and several other countries, clinical trials must be performed to evaluate new drugs/biologics, medical devices, and other interventions used on patients under scientifically controlled settings. Before the intervention can be released to the public, clinical research trials must be performed to determine safety and efficacy of the drug. The Food and Drug Administration (FDA) has published specific guidelines to be used during the in vivo clinical trials on human subjects. Pharmaceutical trials are commonly described in four phases that occur over several years. If the studies demonstrate continued safety and efficacy during this time period, the drug development process typically proceeds. The initial phase involves the first testing in human subjects to observe the in vivo results and delineate safety, tolerability, pharmacokinetics, and pharmacodynamics upon a small group of healthy individuals. The second phase is designed to assess the in vivo results on a larger group of human subjects assessing clinical efficacy. The third phase is typically designed to delineate assessment of the efficacy compared to current standard of care therapies; larger groups of subjects are used for this phase. The final phase of pharmaceutical trials involves the postlaunch safety surveillance. Sometimes long-term or unexpected and rare adverse effects are discovered once larger groups of patient populations are using the treatment and undergoing the in vivo human subject exposure. The use of human subjects raises ethical issues for in vivo research. Consequently, institutional review boards (IRBs), also commonly known as an ethical review boards, exist to formally review and monitor research involving human subjects. The mission of these boards is to protect the rights and welfare of research subjects. IRB approval is required to conduct research funded by both the FDA and the Department of Health and Human Services.
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SEE ALSO: Food and Drug Administration (FDA); In Vitro;
Institutional Review Board (IRB); Medical Jurisprudence.
Robert Amdur, Institutional Review Board Member Handbook (Jones and Bartlett, 2002); Illustrated Stedman’s Medical Dictionary, 24th ed. (Williams & Wilkins, 1982); Bruce R. Neibuhr, Handbook of Clinical Trial and Epidemiological Research Designs January 2000, http:// www.sahs.utmb.edu/Pellinore/intro_to_research/clinirls. htm (cited February 22, 2007); Wikepedia, “In Vivo,” http:// en.wikipedia.org/wiki/In_vivo (cited February 22, 2007); Bibliography.
Ann M. Karty, M.D. Kansas City University of Medicine and Biosciences
Inbreeding Inbreeding is the mating of closely related individuals, yielding offspring characterized as inbred. The principle biological consequence of inbreeding is decreased genetic variation in inbred individuals as compared to non-inbred individuals. This can manifest a higher incidence of diseases with a recessive genetic basis and other abnormal pregnancy outcomes (stillbirth, etc.). Because individuals in different societies (as well as different individuals within the same society) may have different definitions of “closely related,” some prefer the use of the term consanguinity, which refers to the existence of any common ancestor among a subject’s parents (although in practice, such analysis rarely looks at relationships more distant than the second or third cousin or equivalent). It is also worth noting that distinctions between “inbreeding” and “consanguinity” are not uniformly agreed upon and that sources often use the two interchangeably. Biological Significance The relative importance of inbreeding in contributing to the incidence of disease depends largely on the prevalence of the recessive allele in the population at large. If the recessive allele in question is relatively common, then the impact of inbreeding or consanguinity will not be significant unless the frequency of inbreeding is such that it is the rule rather than the exception. A good example of this is Tay-
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Sachs disease and a population of Ashkenazi Jews in the United States. Carrier frequency in this population is thought to be as high as one in 30. If this population mated randomly, the incidence of TaySachs would be sufficiently high that the increased incidence from sporadic inbreeding would be negligible. This incidence can be contrasted with that of the general public, which is one in 300. Because the background rate of Tay-Sachs in such a population is much lower, the influence of any inbreeding is necessarily greater. It should be cautioned, however, that the risks of inbreeding are not so great as is popularly imagined. While the risk for particular (rare) conditions may be markedly increased when inbreeding is present, it should be remembered that the average, non-inbred individual contains 8 to 10 mutations for autosomal recessive disorders. Thus, while it has been estimated that three to five percent of pregnancies arising from the mating of first cousins produces an abnormality (stillbirth, neonatal death, or congenital malformation), the overall rate of birth abnormalities for the general population stands at two to three percent. Inbreeding around the World The risk of inbreeding is only half the picture when considering the overall impact of inbreeding. Consideration must also be given to the prevalence of inbreeding. Unfortunately, there is a paucity of population-level data on inbreeding prior to the end of World War II. While anecdotal evidence and sporadic studies on the phenomenon exist from before this time, there was not much serious outside scholarship looking at the issue, a key when considering a social practice considered unremarkable by those who practice it. What is known is that currently, rates of inbreeding vary significantly between countries and that those countries with high rates of inbreeding are concentrated in a region stretching from Morocco to southern India or China and east Asia depending on the definitions and survey methods used. Furthermore, immigrants from these countries continue the marriage practices of their home countries even in countries where such practices are not the norm. Religion and Inbreeding There appears to be no consistent reason given by the world’s major religions for the various forms of
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marriage preference, and even within the major religions there are marked differences in attitude to varying forms of inbreeding. Within Christianity, the Orthodox churches prohibit consanguineous marriage; the Roman Catholic Church currently requires diocesan permission for marriages between first cousins (and discourages several other forms of inbreeding), and many Protestant denominations permit marriages up to and including first-cousin marriages. A similar degree of nonuniformity exists in Hinduism, both as a matter of theology and in practice. Hindus from the northern region of India typically frown upon marriage between biological kin for several generations (far in excess of the Western first-cousin taboo). By comparison, Hindus in south India strongly favor marriage between a son and the mother’s brother’s daughter; uncle–niece marriages also are seen. In general, Muslim regulations on marriage parallel the Judaic pattern detailed in Leviticus 18. However, uncle–niece marriages are permitted in Judaism. They are forbidden by the Koran, even though double firstcousin marriages, which have the same coefficient of inbreeding, are recognized within Islam. Buddhism sanctions marriage between first cousins, as does the Zoroastrian tradition. The Sikh religion forbids consanguineous marriage, although some minority Sikh groups appear to honor this commandment in the breach, particularly with more-distant relations. It has also been claimed that diaspora groups engage in higher rates of inbreeding than their nonmigratory companions because such groups tend to immigrate as families and because immigration law in the Western countries they immigrate to (Canada, the United Kingdom, and the United States) tend to favor the granting of visas to spouses over cousins and uncles. Research in this area is ongoing; it is not yet clear if other sociodemographic factors explain this differential rate of inbreeding. Legislation Just as different religions have different perspectives on what level of inbreeding is unacceptable, so do various legal jurisdictions. Whereas first-cousin marriages are legal in the United Kingdom and Australia, they are illegal in many U.S. states (although exceptions can be incorporated into state laws, particularly for the practices of particular religious and ethnic
groups). Legal analysis in this area should be considered carefully as not all legislation is enforced in practice. For example, in India, the 1955 Hindu Marriage Act bans uncle–niece marriage, but a study conducted between 1980 and 1989 in two large cities in southern India concluded that 21.3 percent of Hindu marriages there were uncle–niece marriages. Sociodemographic Forces and Inbreeding Just as there is variation in religious and legal guidance on an institutional level, there is also variation in social forces felt at a local level, influencing inbreeding practices in communities around the world. The reasons most commonly given for the popularity of inbred marriage can be summarized as tradition, social cohesion, maintenance of scarce resources (particularly in societies where dowries are common), domestic harmony, and greater stability of marriage. The degree of social similarity and the reduction in the number of in-laws may explain the greater stability that has been claimed for inbred unions (which do have lower divorce rates and a higher degree of female autonomy than non-inbred marriages from the same social group). Incidence of inbred marriage has been associated with low socioeconomic status, illiteracy, and rural residence, although counterexamples are rife. The most prominent example of this is the ruling aristocracy of Europe: the imperative to marry other members of the same ruling class and the use of marriage as a method to seal alliances created significantly inbred family trees with well-known consequences, the most commonly known being the hemophilia of the Romanov Dynasty in Russia. Despite the prominent counterexample of inbred royalty, the vast majority of inbred marriages occur in the region from Morocco to south India, one that has historically been relatively poor and rural. Although such practices in this region are centuries old, trends may soon change. Whereas as many abnormal pregnancies previously ended in stillbirth and infant mortality was high, modern advances in medical care are creating a growing population of offspring dependent on the state for expensive support services. This may eventually prompt efforts to lower the rate of inbred marriage in this region to levels seen in the West. While tradition cannot be readily overturned, it is likely that as the correlates for inbred marriage are
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eradicated by improving economic conditions, improved educational infrastructure and increasing urbanization, societies will be increasingly unwilling to tolerate traditions that impose such consequences. SEE ALSO: Birth Defects; Coefficient of Inbreeding. Bibliography. A.H. Bittles, A. Shami, and N. Appaji
Rao, “Consanguineous Marriage in Southern Asia: Incidence, Causes and Effects,” Minority Populations: Genetics, Demography and Health, eds. A.H. Bittles and D.F. Roberts (Macmillan, 1992); R.L. Nussbaum, et al., Thompson & Thompson: Genetics in Medicine, 6th ed., revised reprint (Saunders, 2004); S. Sailer, “Cousin Marriage Conundrum,” The American Conservative (January 13, 2003).
Bimal P. Chaudhari Boston University
Incidence Incidence is a measure of disease occurrence used in the field of epidemiology. Incidence describes the number of new cases of a disease or condition that occur in a population at risk. There are three primary components needed to calculate incidence: the population at risk, the length of time that the population is at risk, and the number of new cases that arise. Two types of measures are used to describe incidence: cumulative incidence (also called incidence proportion) and incidence rate (also called incidence density). Cumulative incidence describes the number of new cases among the population at risk observed over the observation period of interest. Conceptually, this describes the probability that an individual in the observed population at risk will contract the disease or condition. It is best used in studying a closed cohort, which includes an identifiable population at a given point of time, allowing only loss to follow-up. The formula used to determine cumulative incidence is: cumulative incidence = (# new cases)/ (n of population at risk during observation period) Incidence rate describes the number of new cases over person-time, or the sum of the time that individu-
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als in the population at risk are observed. Conceptually, this describes the change in the number of cases in relation to change in a unit of person-time. This is best used for an open cohort, where individuals join and leave, thus contributing varying amounts of observed time to the analysis. It is described by the following formula: incidence rate = (# new cases)/(person-time) Calculating appropriate incidence requires properly determining the population at risk, which is impacted by additions through birth, or loss through death, migration, and other similar events. Individuals also typically cease to be included in the population at risk once they have developed the disease or condition under study. Incidence is also affected by determination of new cases. If the condition of interest can occur within a given subject more than once, the determination to count each episode or only the first or last episode of the disease or condition changes the calculation. SEE ALSO: Cohort Study; Epidemiology; Prevalence. Bibliography. Donna Crowley, Handbook of Statistics in
Clinical Oncology (Marcel Dekker, 2005); Jose Granados, “On the Terminology and Dimensions of Incidence,” Journal of Clinical Epidemiology (v.50, 1997). Constance W. Liu, M.D. Case Western Reserve University
Incontinence Incontinence is defined as the inability to control excretory functions, generally the inability to control urine and fecal excretion. Incontinence is a common medical problem in both children and adults, generally affecting the earliest and latest years of life. Urinary incontinence alone, for example, affects an estimated five to 15 percent of community-dwelling older adults. Normal urination and defecation are controlled by the autonomic nervous system of the body, which is composed of the parasympathetic and sympathetic nervous system. In general, the sympathetic nervous system promotes retention of feces and urine, while
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the parasympathetic nervous system promotes elimination. The balance of these systems occurs in the levels of the organs involved, spinal cord, brainstem, and cerebral cortex. Voluntary control over elimination occurs in the cerebral cortex. Adults—Urinary Incontinence More than 50 percent of adult residents in long-term care facilities are estimated to have either urinary or fecal incontinence. Incontinence can dramatically influence quality-of-life issues, often leading to social isolation, depression, and institutionalization (in the case of older adults). Nevertheless, it is largely unrecognized and underaddressed in the healthcare setting. Neurologic impairment, immobility, and gender—females are more likely to suffer urinary incontinence than males—are major independent risk factors in adults. Urinary incontinence in adults can be originate from wide range of medical and psychological causes. In many cases, incontinence is only transient. Common causes of transient incontinence include medication side effects, delirium, fecal impaction (often from constipation), urinary tract infections or other infections, irritation of the vagina or urethra, psychological factors such as depression, or physical mobility limitations. There are several forms of more chronic incontinence commonly experienced by individuals. Urge Incontinence—This form of incontinence results from overactivity of the detrusor muscle, a muscle in the bladder wall that promotes elimination. Urge incontinence is generally believed to be the most common form of chronic incontinence. Individuals with this form of incontinence commonly describe a sudden feeling of needing to void before involuntary voiding. Treatments include behavioral management, such as timed voiding schedules and visualization techniques, as well as pharmacologic treatment through medications that decrease contractions of the detrusor muscle. Stress Incontinence—This form of incontinence results from impaired urethral closure. Individuals with this type of incontinence often describe involuntary loss of urine associated with sneezing, coughing, laughing, or lifting objects. Treatment options include pelvic muscle exercises, weight loss in obese patients, use of estrogen, pharmacologic treatments, and surgical procedures, which are generally used for those who fail medical management.
Overflow Incontinence—This form of incontinence results from incomplete emptying of the bladder and abnormally high bladder volumes. This often results from mechanical obstruction of outflow, such as by an enlarged prostate, or from decreased contraction of the detrusor muscle. Individuals generally complain of frequent dribbling of urine, which can be constant, and a feeling of incomplete emptying of the bladder. They often also complain of a decreased force of urinary stream. Treatment options include intermittent catheterization, pharmacologic therapy, and surgery. Functional Incontinence—This form of incontinence results from the inability of an individual to transport in a timely manner to a location to void. Examples include individuals with severe mobility limitations or with dementia. Mixed Incontinence—Many individuals with incontinence often have a combination of the various above types. Adults—Fecal Incontinence Fecal incontinence is common, affecting three to 21 percent of community-dwelling elderly individuals over age 65. Fecal incontinence is also referred to as encopresis, although this term is more commonly used in children. Like urinary incontinence, fecal incontinence can have enormous impact on the lifestyle of an individual. Fecal incontinence can occur transiently in healthy adults in cases such as diarrhea. Fecal incontinence, similar to urinary incontinence, can result from functional difficulties, such as arthritis or other gait difficulties, or poor access to toileting facilities. It can also result from neurological disease, such as spinal cord damage, or damage to the nerves in the intestinal tract or rectum. Other causes include dementia, severe depression, fecal impaction (constipation), neoplasm, and cerebral vascular disease. Children—Urinary Incontinence Girls typically gain bladder control before boys. Toilet training usually begins between ages 2–4. By the age of 5, 90 to 95 percent of children are nearly completely continent during the day, and 80 to 85 percent are continent at night. Diurnal (Daytime) Incontinence—The most common pediatric cause of this form of incontinence is unstable (overactive) bladder. This form is associated
India
with a smaller-than-normal bladder, which has strong, uninhibited contractions. Other causes can include urinary tract infections, neurological disease, infrequent voiding, giggle incontinence, sphincter abnormalities, anatomical abnormalities of the urinary tract, overflow incontinence, sexual abuse, and behavioral causes. Treatment of daytime incontinence varies depending on the etiology. Most children outgrow this problem; however, pelvic floor exercises, behavioral training, and pharmacologic therapy may be helpful. Nocturnal Enuresis—Children often deal with nocturnal enuresis, the occurrence of involuntary voiding at night at 5 years old and older. This problem is more common in boys and it seems to occur more often in children with a family history of the problem. Nocturnal enuresis without overt daytime symptoms affects up to 20 percent of children at the age of 5. Causes may include sleep disorders, psychological factors, urinary tract infections, urinary tract obstruction, sleep apnea, genetic factors, and delayed neurological development allowing voluntary control of voiding. In the majority of cases, the problem ceases spontaneously. Treatment depends on the cause but may include nighttime fluid restriction, motivational measures (reward systems), conditioning therapy (such as use of alarms), psychological therapy, and pharmacologic therapy. Children—Fecal Incontinence In children, more than 90 percent of fecal incontinence, or encopresis, is associated with constipation. Other problems include neurological disease, poor toilet training, psychosocial problems, and other digestive tract disease. Treatment generally involves treating the constipation. More than half of cases resolve spontaneously in two years. SEE ALSO: Constipation; Urinary Tract Infection. Bibliography. John Noble, Textbook of Primary Care
Medicine, 3rd ed. (Mosby, 2000); S. H. Tariq, “Geriatric Fecal Incontinence,” Clinics in Geriatric Medicine (v.20/3, 2004); Richard E. Behrman, “Voiding Dysfunction,” in Nelson Textbook of Pediatrics, 17th ed. (Saunders, 2004). Elizabeth Van Opstal Michigan State University
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India The Republic of India, commonly known as India, is a country in south Asia. With a total population of 1,103,371,000 people (67 percent living in rural areas and 33 percent in urban areas), India is the world’s second most populous country, and the most populous liberal democracy in the world. It is the seventh largest country by geographical area and has a coastline of over 7,000 kilometers. India is bounded by the Indian Ocean on the south, the Arabian Sea on the west, and the Bay of Bengal on the east. India borders Pakistan to the west; the People’s Republic of China, Nepal, and Bhutan to the northeast; and Bangladesh and Myanmar to the east. The country’s 26 states are bordered to the north by the world’s highest mountain chain, the Himalayas. To the south, India is in the vicinity of Sri Lanka, the Maldives, and Indonesia. With the world’s fourth largest economy in purchasing power and the second fastest growing large economy, India has made rapid progress in the last decade, especially in information technology. Today, India has a Gross Domestic Product (GDP) per capita of $1,830. Total health expenditure per capita is $82 (2003 international dollars). Total health expenditure as a percentage of GDP (2003) is 4.8 percent. Although India’s standard of living is projected to continue to rise sharply in the next half-century, the country currently battles high levels of poverty, persistent malnutrition, and environmental degradation. Literacy, defined as the population over age 15 that can read and write, is 59.5 percent. This percentage is highly segregated by gender, as 70.2 percent of males were literate, while only 48.3 percent of females were literate in 2003. The current life expectancy at birth is 61.0 years for males and 63.0 years for females. Child mortality per 1,000 is 81 for boys and 89 for girls. Adult mortality per 1,000 is 275 for males and 202 for females. In India, the risk for major infectious diseases is high. The food- and waterborne disease that are prevalent include bacterial diarrhea, hepatitis A and E, and typhoid fever. Vectorborne diseases that are prevalent and are at high risks in some locations include dengue fever, malaria, and Japanese encephalitis. Indigenous or traditional medical practitioners continue to practice throughout the country. The two main forms of traditional medicine practiced are the ayurvedic (“science of life”) system, which deals with
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India the number of licensed medical practitioners per 10,000 individuals had fallen by the late 1980s to 3 per 10,000 from the 1981 level of 4 per 10,000. In 1991, there were approximately 10 hospital beds per 10,000 individuals. In addition, the integration of health services with family planning programs often causes the local population to perceive the primary health centers as hostile to their traditional preference for large families. Therefore, primary health centers often play an adversarial role in local efforts to implement national health policies.
There are two main forms of traditional medicine practiced in India, the ayurvedic system, and the unani system.
causes, symptoms, diagnoses, and treatment based on all aspects of well-being (mental, physical, and spiritual), and the unani (so-called Galenic medicine) herbal medical practice. A vaidya is a practitioner of the ayurvedic tradition, and a hakim (Arabic for a Muslim physician) is a practitioner of the unani tradition. These professions are frequently hereditary. A variety of institutions offer training in indigenous medical practice. It was not until the late 1970s that health policy referred to any form of integration between Western-oriented medical personnel and indigenous medical practitioners. In the early 1990s, there were 98 ayurvedic colleges and 17 unani colleges operating in both the governmental and nongovernmental sectors. Despite the centuries of traditional medicine, primary health centers remain the cornerstone of the rural healthcare system. By 1991, India had approximately 22,400 primary health centers, 11,200 hospitals, and 27,400 dispensaries. These facilities are part of a tiered healthcare system that funnels more difficult cases into urban hospitals while attempting to provide routine medical care to the vast majority in the countryside. Primary health centers and subcenters rely on trained paramedics to meet most of their needs. The main problems affecting the success of primary health centers are the predominance of clinical and curative concerns over the intended emphasis on preventive work and the reluctance of staff to work in rural areas. Healthcare facilities and personnel increased substantially between the early 1950s and early 1980s, but because of fast population growth,
India and HIV/AIDS India is estimated to have the second largest population of people living with human immunodeficiency virus (HIV)/AIDS, next to South Africa. The National AIDS Control Organization (NACO) estimated that the number of people infected with HIV in India increased from 3.86 million in 2000 to 5.13 million in 2004. In areas that are more severely affected, the epidemic has started to challenge recent development achievements and to raise fundamental issues of human rights concerning people living with HIV/AIDS. The HIV/AIDS epidemic in India is heterogeneous; it seems to be following the type 4 pattern, where the epidemic shifts from the most vulnerable populations (such as sex workers, injecting drug users, and men who have sex with men) to bridge populations (clients of sex workers, people with sexually transmitted infection, and partners of drug users) and then to the general population. The shift usually occurs when the prevalence in the first group exceeds five percent, with a two- to three-year time lag between shifts from one group to another. As of 2004, about 39 percent of people living with HIV/AIDS were women and about 58 percent lived in rural areas where HIV/AIDS services are poor. By the end of November 2005, the total number of reported AIDS cases in India was 116,905, of which 34,177 were women. These data also indicate that about one-third of reported AIDS cases are among people younger than 30 years old. However, many more AIDS cases go unreported. Only 8,097 total AIDS deaths have been reported as of December 2005. This is because many deaths due to AIDS-related causes go unreported because of stigma, discrimination, and problems in claiming life insurance coverage. The spread of HIV is as diverse as the societal patterns between India’s different regions, states, and
metropolitan areas. A total of 111 districts in 18 states are currently considered high-prevalence districts. Another growing problem is that of orphans and vulnerable children and, although official figures are not available, the Joint United Nations Programme on HIV/AIDS (UNAIDS) estimates that more than 170,000 children under 15 years are living with HIV/AIDS. India and Tuberculosis India has more new tuberculosis (TB) cases annually than any other country. Following the sharp growth in spending on TB control and the rapid implementation of directly observed treatment, short course (DOTS), India reached 57 percent case detection countrywide in 2004, and 70 percent within DOTS areas. However, there is not yet sufficient evidence from surveillance and survey data to demonstrate that the TB epidemic is nationally in decline. India’s challenge is to sustain and improve the quality of DOTS, to expand services to manage multidrug-resistant TB and TB linked to HIV, to involve all care providers, and to demonstrate that DOTS is having an impact. Medical Tourism Medical tourism is on the rise worldwide; now multibillion-dollar industry, medical tourism involves patients traveling to different countries for either urgent or elective medical procedures. The reasons patients travel for treatment vary. Many medical tourists from the United States are seeking treatment at substantially reduced costs. Medical tourists from Canada are often people who are frustrated by long waiting times. Patients in Great Britain often feel they cannot wait for treatment by the National Health Service and are unable to afford to see a physician in private practice. For others, becoming a medical tourist is a chance to combine a tropical vacation with elective or plastic surgery. Now more than ever, patients are coming from poorer countries such as Bangladesh where treatment may not be available. India is considered the leading country promoting medical tourism, and now it is moving into a new area of “medical outsourcing,” where subcontractors provide services to the overburdened medical care systems in Western countries. India’s National Health Policy declares that treatment of foreign patients is legally an “export” and deemed “eligible for all fiscal incentives extended to export earnings.” Government
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and private sector studies in India estimate that medical tourism could bring between $1 billion and $2 billion into the country by 2012. The reports estimate that medical tourism to India is growing by 30 percent a year. In fact, India’s top-rated education system is not only churning out computer programmers and engineers, but also an estimated 20,000 to 30,000 doctors and nurses each year. SEE ALSO: HIV/AIDS; Healthcare, Asia and Oceania; Na-
tional Center for Infectious Diseases (NCID); Malaria; National Center for Injury Prevention and Control (NCIPC); Tuberculosis. Bibliography. J.G. Lipson, S.L. Dibble, & P.A. Minarik,
eds., Culture & Nursing Care: A Pocket Guide (University of California San Francisco Nursing Press, 1996); B.J. Paulanka and L.D. Purnell, eds., Transcultural Healthcare: A Culturally Competent Approach (CD-ROM) (F.A. Davis, 1998). Barkha Gurbani University of California, Los Angeles
Indian Health Service (IHS) The Indian Health Service (IHS), an agency within the Department of Health and Human Services, is responsible for providing federal health services to American Indians and Alaska Natives. The provision of health services to members of federally recognized tribes grew out of the special government-to-government relationship between the federal government and Indian tribes. This relationship, established in 1787, is based on Article I, Section 8 of the Constitution, and has been given form and substance by numerous treaties, laws, Supreme Court decisions, and Executive Orders. The IHS is the principal federal healthcare provider and health advocate for American Indians and Alaska Natives. Its goal is to raise the health status of these people to the highest possible level. The agency employs approximately 15,500 people, with examples from nearly every medical discipline providing healthcare, social, and environmental health services. The clinical staff consists of more than 5,000 nurses, physicians, pharmacists, dentists, sanitarians engineers, and various allied health professionals, such
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as nutritionists, health administrators, and medical records administrators. Individuals who have healthrelated degrees have the option of joining the IHS as civil servants or as commissioned officers in the Public Health Service (PHS). The IHS currently provides health services to approximately 1.5 million American Indians and Alaska Natives who belong to more than 557 federally recognized tribes in 35 states. The IHS provides a comprehensive health services delivery system for American Indians and Alaska Natives with opportunity for maximum Tribal involvement in developing and managing programs to meet their health needs. The IHS goal is to ensure that comprehensive, culturally acceptable personal and public health services are available and accessible to all American Indians and Alaska Natives. The IHS assists tribes in developing their health programs through activities such as health management training, technical assistance, and human resource development, coordinating health planning, obtaining and using health resources available through a number of government programs, operating comprehensive healthcare services and health programs, providing comprehensive healthcare services including both hospital and ambulatory medical care and preventive/rehabilitative services, and developing community sanitation facilities. The IHS also serves as the principal federal advocate in the health field for Indians to ensure comprehensive health services for Indian people. Many IHS programs center on preventive measures involving environmental, educational, and outreach activities are combined with therapeutic measures into a single national health system. Within these broad categories are special initiatives in traditional medicine, elder care, women’s health, children and adolescents, injury prevention, domestic violence and child abuse, healthcare financing, state healthcare, sanitation facilities, and oral health. Most IHS funds are appropriated for American Indians who live on or near reservations. Congress also has authorized programs that provide some access to care for Indians who live in urban areas. SEE ALSO: Department of Health and Human Services
(DHHS).
Bibliography. Indian Health Services, www.ihs.gov/
index.asp (cited September 2006); Everett R. Rhodes,
American Indian Health: Innovations in Health Care, Promotion, and Policy (Johns Hopkins University Press, 2002); United States Department of Health and Human Services, www.hhs.gov/ (cited September 2006). Ben Wynne, Ph.D Gainesville State College
Indonesia The Republic of Indonesia covers a large archipelago of islands in southeast Asia and was the Dutch colony known as the Netherlands East Indies until World War II. During the war, it was occupied by the Japanese, and after the war, there was another conflict which saw the Indonesian nationalists defeating the Dutch, achieving independence. Indonesia has a population of 238,453,000 (2004) and has 16 doctors and 50 nurses per 100,000 people. The provision of healthcare in Indonesia varies considerably with the capital, Jakarta, having the best facilities, and also good facilities in many other major cities, and on the island of Bali which is visited by many tourists. The Dutch did not invest much in healthcare, with hospitals catering for Europeans and the Indonesian elite. Indeed, the life expectancy was so low, with Europeans often only lasting one year in Batavia, the administrative capital (modern-day Jakarta), that when Willem Daendels was appointed governor of the Netherlands East Indies in 1807, he did try to improve the terrible levels of sanitation in Batavia. This involved moving the city’s cemetery, and clearing the canals to allow for sewage to flow out of the city into the sea. From 1910, the Dutch started to improve the provision of public healthcare, giving injections for smallpox to many people throughout the archipelago. During the 1930s as advances were made in tropical medicine, the provision of healthcare improved considerably in the country, and by 1936, there were 500 hospitals throughout the Netherlands East Indies, some of which were really clinics, 15 asylums for the insane, 42 leper colonies, and 970 dispensaries. Most of these were run by the Government Medical Service, but there was also a considerable private input. The Dutch also ran a model program
which was established at Purwokerto in Jawa Tengah province (West Java). With the Japanese invasion of the Netherlands East Indies, the health services collapsed with the Dutch medical personnel either being killed, fleeing, or being interned by the Japanese. After World War II, the Dutch-Indonesian War saw little new investment in hospitals, but the situation changed in the 1950s. The major health problems that faced Indonesia were to do with diet, and also malaria, dysentery, typhoid, and cholera. There has also been a problem with venereal disease, rabies, hepatitis, and, in more recent years HIV/AIDS, and also strains of influenza. In some places there has also been the need to treat people suffering from snake or jellyfish bites. To combat these problems, President Sukarno, who controlled the country until 1965, invested heavily in building up the healthcare system, with hospitals, clinics, and pharmacies opening throughout the country. President Suharto, who followed him, and ruled until 1998, presided over a period of great prosperity which saw more hospitals and medical care facilities being built. However, unlike most other countries in southeast Asia, the provision of healthcare has, since 1965, received little government subsidy, although it is overseen by the Ministry of Health and Social Welfare. The Ikatan Dokter Indonesia (Indonesian Medical Association) was founded in 1950 and has 45,000 members. It publishes BIDI each fortnight, and the Majalah Kedokteran Indonesia. There are also a number of research institutes in the country catering for particular disease, including the Lembaga Malaria (Malaria Institute), founded in 1920; the Clinical Institute for Leprosy Research, founded in 1935; and the Unit Diponegoro, catering for nutrition, founded in 1937. A Research Center for Cancer and Radiology was established in 1974, under the direction of the National Health Research Institute; and three years later, the Indonesian Cancer Society was founded in Jakarta. Mention should also be made of the Indonesian Index of Medical Specialties (IIMS) which provides a list of pharmaceutical preparations which can be prepared in the country. The hospitals in Jakarta include Pondok Indah in the southern part of the city, and St. Carolus Hospital, a Roman Catholic hospital which provides emergency care. For the island of Bali, with large numbers
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of tourists, the healthcare system has been much better than many other parts of the country. However, in spite of that, during the Bali bombings in 2002, many of the injured were evacuated to Darwin in Australia for treatment for burns. Elsewhere in Indonesia, most cities and towns have hospitals and clinics, with serious illnesses either being treated in regional capitals, and some foreigners in the country preferring treatment either in Jakarta or overseas in Singapore. SEE ALSO: Healthcare, Asia and Oceania; Malaysia. Bibliography. Indonesia: Health Planning and Budgeting
(The World Bank, 1991); Ann Pembrooke McCauley, The Cultural Construction of Illness in Bali, (Ph.D. thesis, University of California, Berkeley, 1984); David Mitchell, et al., eds., Indonesian Medical Tradition: Bringing Together the Old and the New (Australian Indonesian Association, 1982); Charles Robert Snyder, Indonesian Civil Service Physicians and Private Medical Practice: Incentives and Disincentives for Physician-Delivered Health Service in the Public Sector (PhD thesis, University of Michigan, Ann Arbor, 1990). Justin Corfield Geelong Grammar School, Australia
Indoor Air Pollution The presence of polluted air inside livable spaces is as old as civilization itself. In earlier societies, the primary causes of pollution came from burning wood, peat, and fossil fuels in conjunction with poor ventilation. However, present-day sources of indoor air pollution are more varied and have wide-ranging health consequences. Sources of indoor pollution include ambient air pollutants, bioaerosols, and physical pollutants such as radon, asbestos, heavy metals and particulates; volatile organic compounds such as formaldehyde, polynuclear aromatic compounds, polychlorinated biphenyls; pesticides; and noise. Many people assume the air inside their homes or offices are cleaner than the air outside. This, however, is not necessarily true. While indoor air does not have automobile or factory emissions to contend with, there are many other pollutants that are found indoors. In most cases, there are multiple pollutants
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that can be found in the home. While pollutant levels from individual sources may not pose a significant health risk by themselves, most homes have more than one source that contributes to indoor air pollution. Alone, these pollutants are not significant but their cumulative effect poses a serious health risk. Asbestos is a major source of indoor air pollution and can be found mostly in older homes within pipe and furnace insulation materials and floor tiles. Each of these presents a significant health risk indoors. Smoking is one of the largest sources of indoor air pollution and is a significant cause of lung cancer. Tobacco smoke contains many different chemicals that cannot be completely eliminated with ventilation and air filters. Carbon monoxide and nitrogen dioxide are emitted by combustion products like stoves, fireplaces, and heaters. These gases comprise a large health risk and at high concentrations can lead to death. Outside, the health risk presented by these pollutants is much smaller and not of much concern. Asbestos, a fibrous mineral, is most often too small to be seen by the naked eye and is found mostly in building material; when asbestos fibers become damaged, they can become airborne and are a serious health risk. Asbestos is common on surfaces in older buildings; the exposure of these materials to wear and damage makes the asbestos likely to fray. Because of the small size of asbestos fibers, once they are inhaled, they accumulate in the lungs. The symptoms of diseases caused by continual exposure may not be noticed until years later. Asbestos can cause lung cancer, mesothelioma (a cancer of the chest and abdominal linings), and asbestosis (irreversible lung scarring that can be fatal). In removing asbestos, it is possible that it could become airborne, so as long as it is in good condition, there is no health risk. Tobacco smoke contains many different compounds, some of which can lead to cancer and other respiratory diseases. Tobacco smoke contains approximately 4,700 different types of chemicals. There is an obvious health risk among people who smoke; however, because of secondhand smoke, there is a significant health risk among people who do not smoke. Indoors, tobacco smoke tends to become concentrated, even with ventilation and air filters, which cannot eliminate it completely, mainly because of the large number of pollutants such smoke contains. Tobacco smoke is the
leading cause of lung cancer; the best defense against it is to eliminate it from indoor settings. Carbon monoxide, another common indoor air pollutant, is an odorless gas that comes from many different sources including tobacco smoke, automobiles, and improperly adjusted gas appliances. Extreme exposure can result in death. Health effects, at low concentrations, include fatigue in healthy people and chest pain in people with heart disease. At higher concentrations, effects include impaired vision and coordination, headaches, dizziness, confusion, and nausea. Many of these symptoms are misdiagnosed as symptoms of the flu and are overlooked. Many people are asleep when overcome by carbon monoxide gas or fall asleep as a result of the poisoning and never wake up. When a series of symptoms and ailments that impact humans is connected with a building, the building becomes known as a sick building. The sick-building syndrome and building-related illnesses such as Pontiac fever, Legionella pneumophila fever, rhinitis, humidifier fever and hypersensitivity pneumonitis or lung infections, cancer, bronchide asthma, headache, dizziness, fatigue, and difficulty concentrating are caused by a variety of contaminants. Identifying and controlling these contaminants helps to eliminate sickness related to indoor air pollution. The best way to eliminate indoor air pollution is to eliminate its source. For pollutants such as tobacco smoke, elimination of its presence indoors is the only way to eliminate the pollution it creates. However, this strategy will not work for every type of indoor air pollution simply because some of the sources of pollution are within the building itself or emitted from important appliances. The next best solution would be to regulate the pollution with proper ventilation. Ventilation, coupled with air filters, helps regulate pollution; however, the only way to completely eliminate any type of indoor air pollution is to eliminate the source. SEE ALSO: Asbestos/Asbestosis; Asthma; Asthma in Chil-
dren; Legionnaire’s Disease.
Bibliography. H.E. Burroughs and Shirley J. Hansen,
Managing Indoor Air Quality, 3rd ed. (Fairmont Press, 2004); Consumer Product Safety Commission (CPSC) and Environmental Protection Agency (EPA), The Inside Story: A Guide to Indoor Air Quality, CPSC Document
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#450 (CPSC and EPA, 1993); E. Willard Miller and Ruby M. Miller, Indoor Pollution (ABC-CLIO, 1998). DeMond Shondell Miller Joel Yelin Rowan University
Infant and Newborn Care The goal of routine care for newborns and infants is to promote healthy development through proper nutrition, routine vaccinations, and early detection and prevention of disease. Neonatal Period Directly after delivery, neonates should be assessed using the APGAR score. The APGAR score is a method of assessment using five areas, scored on a scale of 0–2, to evaluate neonates after birth. The areas assessed include appearance (skin coloration), pulse (heart rate), grimace (reflex irritability), activity, and respirations (breathing rate and effort). Generally, an APGAR score above 7 is considered normal. The APGAR score determines the need for immediate medical care and is not a predictor of long-term development. Within the neonatal period, preventative measures should be taken to guard against commonly acquired infections and conditions. This includes the administration of an antimicrobial agent such as erythromycin to both eyes and vitamin K given intramuscularly to prevent conjunctivitis of the newborn and hemorrhagic disease of the newborn, respectively. Neonates should be monitored for jaundice (elevated bilirubin levels in the blood) and screened for specific disease states and inherited conditions. Screening recommendations vary from state to state; however, at minimum, all states must screen for phenylketonuria (PKU) and congenital hypothyroidism. Most states also screen for additional inherited diseases such as sickle cell disease and congenital adrenal hyperplasia (CAH). Certain states participate in an expanded newborn screening. Human immunodeficiency virus (HIV) testing, while not routinely done, should be conducted if the mother is HIV positive or engaging in high-risk behaviors. Blood typing is done if
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the mother has type O blood or is Rh (Rhesus factor) positive to monitor the neonate for erythroblastosis fetalis which consists of anemia, jaundice, respiratory difficulties, and enlargement of the liver and spleen. Many, but not all, states require a hearing screen before the baby is discharged. The umbilical cord should be exposed to air and swabbed daily with rubbing alcohol to prevent infection. The umbilical cord stump detaches spontaneously in approximately one to three weeks. Circumcision of male neonates should be offered and, if desired, should be done within the first few days of life. The American Academy of Pediatrics’ policy regarding circumcision is that while newborn male circumcision has potential medical benefits, it also has disadvantages and risks; thus, parents should determine what is in the best interest of their child. Healthy neonates are usually discharged at 48 hours of life and should be followed up in approximately three days by a healthcare professional. Nutrition Both the World Health Organization and the American Academy of Pediatrics endorse breastfeeding as the optimal form of nutrition for infants and recommend exclusive breastfeeding for a minimum of six months. In addition to nutritional completeness, breastfeeding provides psychosocial and immunological benefits. Human milk supplies all of the fluid and nutrition an infant needs. However, iron-fortified rice cereals should be encouraged at the age of 6 months. Infants should not be given additional water for drinking due to the risk of hyponatremia (low sodium in the blood). Infants less than 1 year should not be given cow’s milk. The only acceptable replacement for breast milk in the first year of life is commercially manufactured infant formula. Types of infant formulas include cow’s milk-based, soy protein-derived, and specialized infant formulas, such as those for premature infants. Both breast milk and the typical infant formula contain 20 kcal/oz. Depending on age, infants should gain between three to eight ounces per week. Breastfed infants should be fed on demand or approximately every two hours, with a decreasing frequency as the infant ages. Bottle-fed infants can go approximately three to four hours between feedings, as formula is digested more slowly than human milk. At 1 year of age, whole cow’s milk may be substituted for breast milk or formula.
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Infant and Toddler Development tion, “WHO Child Growth Standards,” www.who.int/ childgrowth/en/ (cited April 2007). Angela J. Garner, M.D. Danielle Webster University of Missouri–Kansas City School of Medicine
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Routine healthcare is important for newborns and infants to promote healthy development.
Vaccination Immunizations help to prevent communicable diseases. Childhood immunizations are responsible of the control of once prevalent infections such a polio, measles, mumps, and tetanus. The Centers for Disease Control and Prevention (CDC) publishes a recommended vaccination schedule for infants, children, and adults. Safety Infants should be placed on their back to sleep to reduce the risk of sudden infant death syndrome (SIDS). Infants should ride in rear-facing car seats until they reach nine kilograms (20 lb) and 1 year of age. To prevent falls, the use of baby walkers should be avoided and infants should never be left alone on changing tables or other elevated areas. SEE ALSO: Child Safety; Childhood Immunization; Infant
and Toddler Health; Neonatology; Nutrition; Pediatrics.
Bibliography. Mark Beers, et al., eds., “Approach to the
Care of Normal Infants and Children,” in Merck Manual of Diagnosis and Therapy, 18th ed. (Merck Research Laboratories, 2006); Abraham M. Rudolph, et al., eds., “Routine Postnatal Care and Observation,” in Rudolph’s Pediatrics, 21st ed. (McGraw-Hill, 2002); World Health Organiza-
In order to provide the optimum environment for healthy infant and toddler growth and development, it is essential to understand markers that characterize each stage of growth. If a number of these markers are absent or delayed, there may be an underlying physical or mental condition that needs to be addressed. Early identification of problems is vital to children’s health. Teachers and child care workers may spot problems that parents have not noticed or have been afraid to acknowledge. They may also be able to identify abused or neglected children who exhibit abnormal development. Child development may vary according to culture and environment. Socioeconomic status also plays a major role in development. A child growing up in poverty may develop more slowly in response to nutritional deficiencies and a lack of social stimuli. Limited access to safe food and water and proper healthcare may also delay development. Early in the 20th century, child development scholars in industrialized nations began to understand that children were not just “small adults” but were individuals with unique personalities and distinct needs. In 1933 during the Great Depression, the Society of Research in Child Development (SRCD) was established to apply this concept to improving the lives of America’s children. The focus was on understanding how poverty and social deprivation affected development and on using that knowledge to design policies and programs to alleviate negative effects of poverty. In 1965, President Lyndon Johnson (1908–73) launched his War on Poverty, and Congress established the Head Start Program, which teaches reading and math skills to qualifying children from birth to three years to promote school readiness. Working under the auspices of the Department of Health and
Human Services, the program also offers health, nutritional, and social support to children and families enrolled in the program. Infancy Within hours of a normal birth, most infants are alert and beginning to react to their surroundings. Although immature, all body systems are operating. Infants have the ability to swallow, suck, gag, cough, yawn, blink, and eliminate waste. Hearing is well developed, but it takes several years for vision to reach adult levels. Studies conducted on newborns demonstrate that newborns can already discriminate face-like shapes from straight lines. The startle reflex is also apparent, and newborns react to sudden, unexpected movements and load noises. The grasping reflex allows even the tiniest infants to hold onto someone’s finger. The sense of smell and taste are also evident, and infants will turn away from unpleasant smells and express preferences for sweet tastes over bitter. Physically, heads are large in proportion to the rest of the body. Average birth weight varies from 6.5 to 9 pounds (3 to 4.1 kg) and length varies from 18 to 21 inches (45.7 to 53.3 cm). After losing five to seven percent of birth weigh, infants begin to gain an average of five to six ounces a week. Over the next few days, infants develop their own patterns, alternating from sleep to crying to alertness and returning to sleep. Young infants sleep in the fetal position and should be placed on their backs to offset the chance of sudden infant death syndrome (SIDS). Many infants sleep from three to four hours between feedings, initially requiring from six to 10 feedings per day. Crying and fussing are the major forms of communication for infants. Research reveals that babies respond well to “baby talk,” which is considered essential to language development. Infants react to touch and will turn toward a voice, particularly that of the mother, and will seek out the breast or bottle. They like to be held close over the heart, and wrapping them firmly in blankets (swaddling) is often soothing. A distressed infant may also be quieted by shushing sounds, which remind them of noises heard in the womb. Between two and three months, newborn reflexes begin to disappear. If this does not occur, it may be an indication of neurological problems. At this stage, in-
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fants cry less and begin to engage in social smiling. They entertain themselves as they discover their own fingers and toes. Favorite toys are mobiles and rattles, and babies enjoy games such as bye-bye and pat-a-cake. Attachment to parents and primary caregivers is normal. Around 8 or 9 months, separation anxiety surfaces, and babies object to being away from parents or caregivers. By four months of age as vision improves, and infants pay attention to bright objects, preferring primary colors, particularly red. In one study, infants who were shown both symmetrical and asymmetrical faces expressed a preference for the symmetry of faces that had been identified as “attractive” by adults. Between the ages of five and eight months, however, infant preference was for asymmetry. Young infants who tended to prefer consonant musical tones reacted to variations in rhythm by eight months. Children learn by imitation, and how well infants and toddlers learn to mimic others is a vital key in tracking healthy development. One of the first signs of infant imitation is responding to a smile with a smile. Later, infants learn to mimic other facial expressions and sounds. As normal infants grow, the head and chest circumference become relatively equal. Infants learn to flip from one side to the other in a prone position. They progress to sitting alone and to crawling. Pulling up on someone’s hands or furniture is followed by standing alone. By the end of the first year, many babies have taken their first steps. Following the cooing of early infancy, older infants vocalize simple sounds and begin to say words such as “dada,” “mama,” and “bye-bye.” The infant can now pick up small pieces of food and manipulate a spoon and baby cup. Infants try to brush their own hair and turn the pages of books. They enjoy songs and rhymes and may try to dance and sing. Babies are highly social at this stage and like to be included in family life. They understand approval and will join in clapping. Some infants also exhibit independence by resisting, kicking, or screaming. In some cultures, this independence is strictly discouraged, while others see it as normal. Toddler years At the end of the first year of life, infants become toddlers. Between the ages of 1 and 3, physical growth slows as toddlers learn to master motor and communication skills. Imitation continues to be a major element in normal development, often taking the
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shape of playing house or school or pretending to be princesses or superheroes. Normal toddlers have seemingly unlimited energy, enthusiasm, and curiosity, and they develop more complex thinking and learning abilities. Emotional communication ranges from freely bestowed hugs and kisses to crying and tantrums. Older toddlers understand the concepts of guilt, pride, and shame and display them at appropriate times. Toddlers tend to believe they are the center of the universe. They understand the concept of ownership but may be unwilling to share or take turns. The circumference of the head, which indicates healthy brain development, continues to grow at a rate of one-half inch (1.3 cm) every six months. By the age of 3, most toddlers will have quadrupled their birthweight and doubled their birth height. The toddler body begins to develop an adult-like appearance, although the abdomen protrudes and the back appears swayed until age 3. Even toddlers who walk well may fall when hurrying. Push and pull toys and large balls are ideal for toddlers and help them to develop motor skills and coordination. The toddler can climb into a large chair or sit in a small chair unaided. At the age of one, a toddler draws using whole-arm movement. By the age of the 3, these skills have progressed to finger/thumb manipulation. By the end of the third year, most toddlers are potty trained, but may continue to have accidents when they are engrossed in an activity or while sleeping. By the age of 2, many toddlers learn to manipulate doorknobs. If no child-safety measures are in place, the toddler may leave a room or dwelling without adults being aware. This ability combined with an inherent curiosity makes toddlers prone to wander. Thus, they requires constant adult attention, particularly in public and unfamiliar places. Because the toddler now understands the concept of object permanence, he/she enjoys hiding objects and playing hide and seek. Although toddlers like to play with other children, they may not cooperate or follow established rules. The ability to hold toys or objects in both hands at one time is a key indicator in normal neural development. The toddler should be able to identify body parts and objects, place one object inside another, and make mechanical objects perform their intended functions. The toddler is able to follow simple directions. Language skills progress
Between the ages of 1 and 3, physical growth slows as toddlers learn to master motor and communication skills.
rapidly, and the toddler advances from simple words to whole sentences. By the age of 3, the toddler is able to carry on conversations with others, although some words may not be intelligible. Toddlers begin to understand the concept of cause and effect, but are not always able to identify situations that may pose danger. Appetite begins to decline, and toddlers frequently insist on eating only one or two preferred foods. They can undress themselves and assist in getting dressed, manipulating large buttons, zippers, and Velcro fastenings. The toddler is able to wash his/her hands and imperfectly brush his/her own teeth. Toddlers may sleep 10 to 12 hours a night, but they may try to put off bedtime. By age 3, most toddlers have progressed beyond the “terrible twos” to become friendlier and more cooperative. Females have reached 57 percent of their adult height, and males have reached 53 percent. The average 3-year-old weighs from 30 to 38 pounds (13.6 to 17.2 kg). The head now appears in proportion to the rest of the body, and the body is more erect. Most 3-year-olds have all of their baby teeth, and vision has improved to 20/40. Jumping and hopping are favorite means of locomotion. The child is able to manipulate the pedals of small riding toys, and hand dominance
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is apparent. Many toddlers are able to identify primary colors, identify common shapes, and count from one to 10 or 20. The 3-year-old vocabulary generally contains between 300 and 1,000 words, and the child may memorize favorite songs, stories, and nursery rhymes. In rare cases, 3-years-old have mastered the ability to read. In 2007, research into the development of toddlers took a new direction with the introduction of a Japanese humanoid known as Child-Robot with Biominetic Body (CB2). The focus of the Osaka University project is to amass knowledge of how toddlers learn language and develop object recognition and communication skills. The robot is designed to mirror the motions of a human child, responding to both touch and sound. The 4-foot tall robot weighs 56 pounds and has 56 actuators, 197 touch sensors, and one audio sensor. Cameras serve as eyes, and an artificial vocal cord allows the robot to mimic human speech. When in motion, the robot “toddles.” SEE ALSO: Birth Defects, Child Abuse, Child Develop-
ment, Child Safety, Infant and Newborn Care, Infant and Toddler Health, Neurology, Sudden Infant Death Syndrome (SIDS). Bibliography. J. Lawrence Aber, et al., Child Develop-
ment and Social Policy (American Psychological Association, 2007); Administration for Children and Families, “About Head Start” http://www.acf.hhs.gov/programs/ hsb/about/index.htm (cited June 2007); K. Eileen Allen and Lynn R. Marotz, Developmental Profiles: Pre-Birth through Twelve (Thomson, 2007); Leslie J. Carver and Brenda G. Vaccaro, “Twelve-Month-Old Infants Allocate Increased Neural Resources to Stimuli: Associated Negative Adult Emotion,” Developmental Psychology (v.43/1, 2007); Ann E. Ellis and Lisa M. Oakos, “Infants Flexibility Use Different Dimensions to Categorize Objects,” Developmental Psychology (v.42/6, 2006); “Humanoid Toddler Reacts to Touch, Sound: Robot Designed to Move Just Like A Real Child between One and Three Years Old,” http://www.msnbc.msn.com/id/19112210/ (cited June 2007); Jerome Kagan Norbert and Herschkowitz A. Young, A Young Mind in a Growing Brain (Lawrence Erlbaum, 2005); Alice Park, “Baby Faces,” Time, (v.169/24). Elizabeth R. Purdy, Ph.D. Independent Scholar
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Infant and Toddler Health Access to medical care and proper nutrition are essential to the normal growth and development of infants and toddlers. Infant mortality is one of the most significant indicators of the level of social development within each country. Consequently, mortality rates tend to be lowest in the most industrialized nations and highest in the poorest developing countries. The countries with the highest infant mortality rates are Angola (184.44 deaths per 1,000 live births), Sierra Leone (158.27), and Afghanistan (157.43). Singapore (2.30), Sweden (2.76), and Japan (2.80) have the lowest infant mortality rates. Since the 1950s, infant morality rates have declined in the United States. However, cuts to programs that fund immunization, nutrition, and health initiatives for infants and toddlers, particularly those of the Reagan administration of the 1980s, have meant that the United States trails most other industrialized nations in infant mortality (6.37 deaths per 1,000 live births). In response to improved medical knowledge and technology and the increased attention paid to the correlation between prenatal care and infant and toddler health, the perinatal (within the first month of life) mortality rate has also dropped, and fewer incidences of low birthweight newborns and short gestational births are occurring, thereby improving the overall health of surviving infants and toddlers One of the most important factors in promoting infant health is breastfeeding, which provides strong health protections for infants and has the advantage of being more convenient than bottle feeding. In developing countries, young children are often breastfed for extended periods because breast milk is their primary source of nutrition. Both the World Health Organization (WHO) and the United Nations Children’s Fund (UNICEF) encourage breast feeding for at least two years. In industrialized nations, most infants are weaned by the end of the first year of life, if not sooner. Breastfeeding rates are as high as 98 percent in countries such as Sweden and Norway where government policies encourage the practice. In the United States, 70.0 percent of women breastfeed newborns, but only 36.2 percent continue breastfeeding until the baby is 6 months old. Working mothers who choose to can use a breast pump to express breast milk to be fed to infants by other caregivers. Solid foods are introduced
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as instructed by pediatricians, beginning with cereals and progressing to vegetables, fruit, and meats. Only one new food should be introduced at a time to make it easier to identify allergies that may develop and to determine whether certain foods can be tolerated by individual infants. By 8 to 12 months, infants may eat soft or pureed table food. Nuts, popcorn, whole grapes, and hot dogs should never be fed to infants or toddlers because of the high risk of choking. Infants and toddlers need to visit medical care providers at designated intervals to chart growth and development, have hearing and vision checked, and identify potential problems. UNICEF estimates that of the 10.6 million children under the age of 5 who die each year, two-thirds die from vaccine-preventable diseases. Immunizations that protect children from a variety of preventable infectious diseases are available at physician’s offices and at health clinics around the world. Required vaccinations generally include diphtheria, pertussis (whooping cough), tetanus, polio, measles, mumps, rubella (German measles), Haemophilus influenza type B (Hib), hepatitis B, and chicken pox. Some of these vaccinations are controversial because of suspected links to conditions such as autism and seizures. However, schools may refuse to enroll any child who has not received required inoculations. In developing countries, international organizations such as UNICEF and WHO often work with local governments to promote immunization programs. Immunizations do not protect children from accidental injury, nor do they act as barriers to frequent ear, respiratory, and gastrointestinal infections. Normally, these infections respond well to treatment; however, ear infections have become so common that there is concern that they may become resistant to common antibiotics. When ailing infants and toddlers have diarrhea, they are susceptible to dehydration, which if left untreated, could lead to death. Rehydration formulas are widely available to restore fluid and electrolytes. Even in industrialized nations, poor and immigrant children tend to be in poorer health than those in the general population. Rates of lead and pesticide poisonings are also considerably higher among those segments of the population. Infants and toddlers in developing countries, where access to safe water and food and improved sanitation is limited, are highly susceptible to a host of water, and foodborne diseases
such as hepatitis A and typhoid and to vectorborne diseases such as malaria and dengue fever. Either at birth or shortly thereafter, infants may show the first sign of transmitted or inherited abnormalities. For instance, in developing countries of Africa and Asia, large numbers of infants are exposed to HIV/AIDS. In 1996, the United Nations and the World Health Organization (WHO) estimated that 2.6 million children had HIV/AIDS. Within four years, that number had risen to between five and 10 million. In the absence of intervention, the virus may be transmitted from mother to child. Within the first three or four months of life, recurrent infections and fluid in the ears of exposed infants may be the first indications of AIDS. Three-fourth of all infants with AIDS experience neurological damage. These infants may also experience lung damage, growth failure, craniofacial abnormalities, weakness and apathy, warts on hands, swollen lymph nodes, and thrush. If the new mother is a drug user, newborns may show signs of drug withdrawal and have a number of birth defects. Sudden infant death syndrome (SIDS) has been one of the most mystifying causes of death among infants. SIDS is diagnosed in cases where no other explanation is feasible following an investigation and autopsy. In the past, apparently healthy infant sometimes died while sleeping. The campaign to place sleeping infants on their backs has slashed the rate of SIDS. Today, the leading causes of SIDS deaths are congenital malformations and low birth weights. Atrisk infants often wear monitors to alert parents and caregivers to changes in breathing patterns and heart rates. Mortality rates from SIDS are still higher than normal in inner cities and in some southern states. Some researchers believe there are environmental factors involved in SIDS. In the United States, the Healthy People 2010 initiative has targeted infant and toddler health as part of the effort to improve overall health. Specific goals include reducing iron deficiency by five percent, slashing nonfatal poisonings to no more than 292 per 100,000, reducing growth retardation in under5, low-income children to less than five percent, decreasing infant deaths to no more than 4.5 per 1,000 live births, cutting SIDS rates to 0.30 per 1,000 (in part by increasing the number of infants sleeping on their backs to 70 percent), and improving accessibility to vaccinations and rehydration therapies. As infants
Infectious Diseases (General)
and toddlers become mobile, health risks increase. Therefore, Healthy People 2010 is also working to reduce the risk of drowning deaths among children under the age of 4 to no more than 0.9 per 100,000, increase the use of automobile child restraints for this age group to 100 percent, reduce antibiotic courses for ear infections to 88 courses per 100 children under the age of 5, and reduce lead blood levels in all children under the age of 5. SEE ALSO: AIDS; Autism; Birth Defects; Disease Preven-
tion; Gastroenterology; Infant and Toddler Development; Otology; Pregnancy; Preventive Care; Respiratory Diseases (General); Sudden Infant Death Syndrome (SIDS); United Nations Children’s Fund (UNICEF); World Health Organization (WHO). BIBLIOGRAPHY. Michael S. Clement, Children at Health
Risk (Blackwell, 2003); Andrew Curtis and Michael Leitner, Geographic Information Systems and Public Health: Eliminating Perinatal Disparity (IRM Press, 2006); Carole Lium Edelman and Carol Lynn Mandle, Health Promotion throughout the Life Span (Elsevier Mosby, 2006); Healthy People, http://www.healthypeople.gov/ (cited July 2007); Jenifer, Swanson, Infant and Toddler Health Source Book: Basic Consumer Health Information (Omnigraphics, 2000); H.,B. Valman and R.M. Thomas, ABC of the First Year (BMJ Books, 2002); UNICEF, “One in Four Infants Still at Risk from Vaccine Preventable Diseases” http://www.unicef. org/media/media_28400.html (cited cited July 2007); James Wynbrandt and Mark D. Ludman, The Encyclopedia of Genetic Disorders and Birth Defects (Facts on File, 2000). Elizabeth R. Purdy, Ph.D. Independent Scholar
Infectious Diseases (General) By definition, those diseases that are transmitted from one person to another or between animals and humans (animal to animal, animal to human, human to human, human to animal), implying the transfer of a microorganisms or/and an infectious pathogen agent, are infectious diseases. Infectious agents are living (or at least nucleic acid encoding or proteins) units that must invade the insect host in order to initiate an infection.
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Infectious diseases could be caused by bacteria, fungi, viruses, parasites (protozoan and helminthes) and prions. Ectoparasites produce infestation, a different term to express the presence of a pathogen agent on the external region of the body of the host. Pathogens can be spread by many routes other than direct contact, including through water, food, air, and bodily fluids—blood, semen, saliva, and so on. Many diseases may be transferred by vectors—animals (usually insects) that carry microorganisms (mostly viruses and parasites). Vectors may spread a disease either by mechanical or by biological means (the organisms require a vector to reach specific stages of its life cycle, particularly the infectious stage for the intermediary, accidental and definitive hosts). Mechanical transmission occurs, when flies transfer the germs for typhoid fever from the feces (stool) of infected people to food eaten by healthy people. Biological transmission takes place when an insect bites a person and takes infected blood into its own system. Once inside the insect’s gut, the disease-causing organisms may reproduce, increasing the number of microorganisms that can be transmitted to the next victim. This is how the Anopheles spp. or Aedes spp. mosquito vector, for instance, transfers malaria or dengue, respectively. Additionally, the advance in new areas of activity has let the emergence of new infectious diseases as well new pathogens behavior, and the modification of established methods of transmission. In the medical management of patients, particularly in hospitals, healthcare-associated infections are also a raising concern worldwide (nosocomial infections). Historically, the record of human suffering and death caused by smallpox, cholera, typhus, dysentery, malaria, and so forth establishes the eminence of the infectious diseases. Despite the outstanding successes in control afforded by improved sanitation, immunization, and antimicrobial therapy, the infectious diseases continue to be a common and significant problem of modern medicine. The most common disease of humankind, the common cold, is an infectious disease, as is the feared modern disease AIDS. Some chronic neurological diseases that were thought formerly to be degenerative diseases have proven to be infectious. Day by day, news scientific findings have revealed the role of the infectious agents in chronic diseases such as asthma, multiple sclerosis, some chronic cardiovascular diseases, Whipple disease, gastric diseases, diabetes, and many types of cancer, among others. There is little
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doubt that the future will continue to reveal the infectious diseases as major medical problems. The infectious agent is carried by healthy hosts called reservoirs (e.g., water birds for the flu virus). It is transmitted to the target organism either directly or through carrier organisms. For example, the protozoa responsible for malaria live in mosquitoes, carriers that transmit them through their bites to humans, who develop the disease. The worldwide emergence of diseases once restricted to a particular region is caused by changes in lifestyle and human modification of the environment due to high demographic growth (clearing and deforestation, contact with wild fauna, overcrowding in megalopolises, tourism, immigration, etc.). Since an epidemiological point of view, worldwide, bacterial and viral infectious diseases represent and call the major attention of healthcare systems, in part due to the economical burden for them, related to the medical management of such infections, such antibiotics for bacterial infections. Treating viral illnesses or noninfective causes of inflammation with antibiotics is ineffective, however, and contributes to the development of antibiotic resistance, toxicity and allergic reactions, leading to increasing medical costs. For these reasons in the field of infectious diseases different markers related to distinguish the general etiology of the disease have been aimed and developed. Markers such as the leukocyte and neutrophil counts, serum C-reactive protein (CRP) level and erythrocyte sedimentation rate (ESR), which have relatively poor sensitivity and specificity. But other news, such as procalcitonin, inflammatory mediators such as G-CSF, TNF-a, IL-1b, IL-6, and IL-8, the triggering receptors expressed on myeloid cells (TREM), the neutrophil FcgRI (CD64), the phagocyte complement receptors and the product of platelet and neutrophil counts (PN product), among others, which have been showing relatively good sensitivity and specificity. There are a shifting pattern in the profile of infectious diseases among the countries, developed and developing countries. The majority of developed countries have undergone a prototypical epidemiologic and demographic transition. Host–infectious agent relations have evolved over centuries, but these transitions are largely attributed to a decrease in the burden and mortality from infectious diseases. As a result, life expectancy has radically changed over the past century
with a significant increase in longevity. Although we welcome these improvements in health status, we never imagined that prolongation of life due to fewer infectious diseases would have disadvantages in future generations. It has become evident that inflammatory disorders, including both autoimmune and allergic diseases, are increasing in prevalence to epidemic proportions, particularly in more affluent, industrialized countries over the past 40 years. At the same time, the rate of allergic diseases in the developing world has not changed over the same period of time. There is current scientific evidence that a major player in explaining this tendency could be partially explained by decreased incidence of infectious diseases. In the case of developing countries the situation is different. The world is marked by extremes of economic inequality, across and within countries in which poverty is a common denominator. With incomes in resource-rich countries exceeding thousands of dollars, 20 percent of the world’s population nonetheless survives on less than $1 a day. Inevitably, the economic health of a country both affects and is affected by its people’s health and life expectancy. It has been argued that the health effects of inequalities with respect to income and assets impose a major burden on the poor, which reduces the competitiveness of societies and has an effect on the global marketplace. Therefore, it is in the world’s best interest to ensure the health of all its people, because human health is the foundation of economic growth and development. Many infectious diseases previously seen only in resource-constrained settings can be currently diagnosed anywhere in the globe due to increased travel, immunosuppression, HIV/AIDS; organ transplantation and blood transfusion. SEE ALSO: Environmental Health; Epidemiology; Immu-
nology; Medical Entomology.
BIBLIOGRAPHY. Gordon Cook and Alimuddin Zulma,
Manson’s Tropical Diseases (Saunders, 2003); Paulo Sergio Lucas Da Silva, et al., “The Product of Platelet and Neutrophil Counts (PN Product) at Presentation as a Predictor of Outcome in Children with Meningococcal Disease,” Annals of Tropical Paediatrics (v.27/1, 2007); Erick Folch, et al., “Infectious Diseases, Non-Zero-Sum Thinking, and the Developing World,” American Journal of Medical Sciences (v.326/2, 2003); Carlos Franco-Paredes, Ildefonso
Infertility
Tellez, and Carlos del Rio, “Inverse Relationship between Decreased Infectious Diseases and Increased Inflammatory Disorder Occurrence: the Price to Pay,” Archives of Medical Research (v.35/3, 2004); Carlos Franco-Paredes, et al., “Cardiac Manifestations of Parasitic Infections Part 3: Pericardial and Miscellaneous Cardiopulmonary Manifestations,” Clinical Cardiology (v.30/6, 2007); Jari Nuutila, and Esa-Matti Lilius, “Distinction between Bacterial and Viral Infections,” Current Opinion in Infectious Diseases (v.20/3, 2007). Alfonso J. Rodriguez-Morales, M.D., M.Sc. Universidad de Los Andes, Venezuela Carlos Franco-Paredes, M.D., M.P.H. Emory University
Infertility The clinical definition of infertility is one year of having normal sexual activity without pregnancy, without using contraceptive methods. According to the World Health Organization, infertility affects one out of 10 couples at some point in their lives, with 80 million people affected worldwide. Males contribute to between 40 to 50 percent of infertility cases. While normal male spermatogenesis means men are potentially fertile all the time and throughout their lives, women have a small window each month of approximately six days, ending with ovulation when they are fertile and a limited fertile time between the onset of menses and the cessation of menstruation at menopause. To maximize the chance of getting pregnant, both women and men should understand how the reproductive system works to ensure they are timing sexual activity during a fertile time. The causes of infertility can be on the part of either the man or the woman and vary from blockage in the sexual organs, to being secondary from other illnesses or biologic indicators, to having psychological characteristics, or being caused by environmental exposure to toxic substances. Similarities of infertility issues can be analogous between the genders in the case of hormonal considerations. Not producing or releasing enough sex hormones can lead to anovulation or lack of spermogenesis. The hypothalamus releases gonadotropin releasing hor-
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mone (GnRH), to signal the pituitary to release luteinizing hormone (LH) and follicle stimulating hormone (FSH), which in turn regulates the gonads. A feedback loop of steroid hormones in the circulating blood turns off or stimulates hypothalamic activity. Male contributing factors A reproductive health exam with a specialist will take into account common general factors affecting male fertility, including stress, obesity (estrogen production by adipose tissue blocks GnRH release), genetic disorders, cancer, and tobacco, drug, or anabolic steroid use. Specific factors affecting male fertility include undescended testicles, erectile dysfunction, premature ejaculation, excessive heat (increased temperature impede sperm production), blockage in spermatic cord, and viability of sperm. Average seminal fluid has a neutral pH (approximately 7.2) and contains nutrients for the sperm to use for energy. On average, 100 to 300 million sperm are produced each day. Fertile ejaculate contains adequate volume and concentration of sperm (100 to 400 million sperm) with enough sperm of normal morphology or shape, and the motility or ability to move from the vagina to the fallopian tubes. Problems with morphology or motility are apparent with the occurrence of sperm with pinpointed head, tapered heads, crooked heads, two heads, and coiled or kinked tails. Primary hypogonadism is defined as testicular failure, and secondary hypogonadism is defined as defective secretion of gonadotropins from the hypothalamus and/or pituitary. These hormones target three specialized cells for reproduction—the spermatogonia in the seminiferous tubules, the Leydig cells in the connecting tissue between the coiled seminiferous tubules, and the Sertoli cells forming the basement member of the seminiferous tubules. They provide the environment necessary for germ cell differentiation and maturation. Female contributing factors As with male reproductive health, general factors affect female fertility, including age (women in their late 30s are less fertile than those in their 20s), excessive exercise, stress, weight (either loss or gain), chronic diseases (lupus, polycystic ovary syndrome, arthritis, hypertension, asthma, cancer), and tobacco or drug use. Specific factors affecting female fertil-
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ity include sexually-transmitted disease resulting in tubal blockage, cervical narrowing from infection, cervical fluid inhibiting sperm motility, immune system antibodies attacking sperm, uterine fibroids, and production of viable eggs. Scientists have in the past stated that women are born with all of the eggs they will produce in their lifetime, but new research indicates stem cells may allow women to produce more eggs and extend reproductive ability. Cervical fluid must be conducive to assisting the sperm. During nonfertile times, the cervical fluid is either dry or sticky. During fertile times the cervical fluid assists the sperm into the cervix, and provides additional nourishment to keep the sperm alive. In this type of fluid, the sperm can survive up to five days. In nonconducive or “unfriendly” cervical fluid, the sperm may only live a couple hours, or up to a day or two. Precise timing in regards to sexual activity and ovulation are essential. Endometriosis is the growth of the endometrium outside the uterus, increasing the risk of infertility. Pelvic inflammatory disease (PID) increases risk of infertility with repeated episodes of salpingitis. In addition to physical barriers to fertility, a woman’s reproductive cycle, with involvement by the hypothalamus, pituitary, and ovaries, creates a variety of infertility causes, including timing sexual activity with the short fertile window each month and hormonal adequacy for control and regulation of ovulation and hormonal preparation of the uterus for implantation. The follicular phase is the growth and release of the oocyte. Under the stimulation of FSH, one follicle or more enlarges. The progesterone levels remain low, and estradiol begins a slow rise progressively to its maximum level, 24 hours before the LH/FSH peak and ovulation. The LH peak signals the end of the follicular phase and ovulation commences within 16 to 18 hours of this peak. High doses of estrogen suppress LH and FSH by inhibiting GnRH. Primary hypogonadism is defined as ovarian deficiency either by decreased ovulation or decreased hormone production, and secondary hypogonadism is defined as defective secretion of gonadotropins from the hypothalamus and/or pituitary. Ovarian hormones are necessary for maturing the primordial germ cells into oocytes, developing tissues for implantation of the fertilized oocyte (blastocyst), and for hormonal timing for ovulation. Estrogen
stimulates vaginal and uterine epithelium. Progestins decrease the action of estrogen and begin the secretory process. This decreases peripheral blood flow and heat loss, resulting in increased body temperature during the luteal phase, and indicates ovulation. Persistent anovulation, as in the case of polycystic ovary syndrome, medications can be given to stimulate the ovaries. Testing An initial consultation for fertility includes medical and psychosexual history, followed by physical and genital examinations, and blood testing. Sperm analysis is preformed after three days of sexual abstinence to check for appropriate volume, concentration of sperm, motility and morphology, to determine male contribution to infertility. Abnormal results will require further evaluation for cause (environmental or workplace toxins, drug or alcohol abuse and hypogonadism). Some controversy exists about the cervical factors affecting fertility, even so most gynecologists include a postcoital test. Timing the test just before ovulation and within six hours of sexual activity, and a small drop of cervical fluid is obtained from within the cervical os (the opening in the cervix) is examined under the microscope. The presence of five or more active sperm per field is a satisfactory reading. The presence of three or more white blood cells in the test indicates either female cervicitis or male prostatitis. After the next menstrual period, an X-ray can determine uterine abnormalities and tubal obstruction. Additional testing may include testing of LH and FSH levels, an ultrasound examination of the ovaries for maturing and unruptured follicles, and an endometrial biopsy during the luteal phase, to rule out luteal phase deficiency. Treatment options While maintaining a healthy lifestyle is necessary, physicians will provide options for treatment, including counseling to find fertile times, using ovulation predicting kits, and following basal body temperature changes. Surgery and medication to correct reproductive problems may be necessary. Agonists 17 α-ethinyl estradiol and mestranol are oral contraceptives used to regulate the reproductive cycle, in preparation for additional medication therapy, to promote fertility as soon as the contraceptive
Inflammatory Bowel Disease
is discontinued. Antagonists compete with estradiol for intracellular receptor. Clomiphene competes with estradiol for hypothalamic receptor sites. GnRH is not restrained, and increasing amounts of LH and FSH are released by the pituitary to make multiple follicles mature simultaneously with the potential for multiple pregnancies. For cases of inadequate transport of sperm, intrauterine insemination is an option, where sperm with seminal fluid, debris, mucus, and fat globules are removed is injected into the uterus with a catheter. Assistive reproductive technology includes three different technologies—invitro fertilization (eggs and sperm are collected, fertilized, and transferred into the uterus), zygote intrafallopian transfer, and gamete intrafallopian transfer. Of these, invitro fertilization is most common and more universally offered. Artificial insemination is available for those who are unable to have a biologically shared child. Sperm donation allows the woman to have a biological child with donated sperm; egg donation can combine the man’s sperm with a donated egg followed by invitro fertilization, or embryo donation with donated sperm and egg can be used for women healthy enough to give birth. The prognosis is positive for minor, including multiple, causes of infertility, with treatment. Severe infertility is untreatable and of prolonged duration. Regardless of the cause of infertility, couples may experience feelings of inadequacy and additional stress and strain on the relationship. As important as the physical treatment, counseling and therapy may be needed to deal with the psychological aspects of difficulty or absence of reproduction. If treatment does not work, couples additionally have the option of adoption, foster parenting, and birth by surrogate. See Also: Gynecology; Impotence; Menstruation and
Premenstrual Syndrome; Reproductive Health (General).
BIBLIOGRAPHY. H. Trent MacKay, “Gynecology,” in Cur-
rent Medical Diagnosis & Treatment 2004 (Lange, 2004); Daniel A. Potter, and Jennifer S. Hanin, What to Do When You Can’t Get Pregnant (Marlowe, 2005); World Health Organization, “Infertility,” www.who.int/reproductivehealth/infertility/ (cited April 2007). Lyn Michaud Independent Scholar
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Inflammatory Bowel Disease Inflammatory bowel disease consists of two disorders: Crohn’s disease and ulcerative colitis. Both conditions result from abnormal activation of the body’s immune system, resulting in an inflamed bowel and concurrent systemic symptoms. These are chronic, idiopathic, and relapsing and remitting disorders, more common in the developed world. Crohn’s disease is autoimmune and involves widespread inflammation throughout the gastrointestinal tract, while ulcerative colitis is limited to the colon. The luminal layer of the gastrointestinal tract (called the mucosa) is colonized normally with microflora. This flora is of functional significance. The human body does not consider the flora as an antigenic or pathogenic entity. In inflammatory bowel disease, the tables turn, and the host’s immune system gets activated against its own flora, causing an inflammation against the normal mucosa, resulting in defective function. Because the immune response is directed against the body’s own tissues, this is an autoimmune disorder, involving abnormal immune responses, genetic predisposition, and environmental triggers. The development of this disease strongly depends on genetic predisposition. Fifteen percent of inflammatory bowel disease patients have first-degree relatives who also have the disease, and the lifetime risk of either a parent or a sibling being affected is 9 percent. However, the disease is a multigenic trait. This means that several genes will control the eventual clinical presentation of the disease, thus resulting in variable symptoms. Animal studies have elucidated the importance of gut flora in the development of inflammatory bowel disease. It is thought that defects in the barrier of the gut wall could cause the lymph tissue to be exposed to the microflora resting on the mucosal surface. This causes an immediate immune response against the normal gut flora, causing the inflammation. Environmental triggers, such as irritants in the diet, can also trigger a relapse by acting as a microbe against which an immune response is launched by the body. The specific nature of the type of immune response is another aspect of inflammatory bowel disease research. T cells of the immune system are involved in autoimmune responses against self-antigenic in the
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body. These cells are cytotoxic and kill the cells of the body if they exhibit certain apoptotic (suicidal) proteins, or abnormal antigens (such as viral proteins exhibited on the surface of the cell that is infected with the virus). Such cells attack the normal cells in cases of autoimmune disease, and in inflammatory bowel disease, they target the intestinal mucosal cells. Crohn’s disease is a type of delayed hypersensitivity response that is chronic and induced by interferon gamma–producing T helper cells 1. Ulcerative colitis is cause by T helper cells 2. Diagnosis of inflammatory bowel disease is largely dependant on clinical history, radiographic examination, laboratory findings, and pathological examination of tissue. Microscopic histological assessment defines the diseases. Crohn’s disease is also called regional enteritis. The disease consists of patchy areas of affected mucosa alternated by areas of normal mucosa. The region of inflammation could be anywhere throughout the length of the gastrointestinal tract, that is, from the mouth, esophagus, stomach, small intestine, large intestine, rectum to the anus. As a consequence of repeated inflammation, the intestinal wall becomes rubbery and thick due to edema. The tissue undergoes fibrosis and scar formation and the muscular layer of the intestinal wall hypertrophies, causing the lumen itself to reduce. The narrow lumen causes the classic presentation of “stringy sign” in a barium meal’s X-ray. Despite the severity of the disease in some areas, other parts of the gastrointestinal tracts may be very much unaffected. Early features of the disease show point sores that progress to ulceration. Ulcerated areas coalesce causing serpentine ulcers along the long axis of the bowel. The normal smoothness of the mucosal surface is lost and fistulas and fissures commonly develop. Clinical symptoms of the patient include mild diarrhea, fever, and abdominal pain. The episode is followed by an asymptomatic period, which can vary in duration. Fecal blood loss can be present but is usually not as severe as that in ulcerative colitis. Acute flare-ups can also present themselves as an appendicitis episode, with pain in the lower right quadrant of the abdomen. Repeated bouts of diarrhea cause fluid loss and electrolyte imbalances. Furthermore, fibroses and fistulas can be common complications; because the normal functional capacity of the mucosa is lost, there can be substantial loss of protein and fat and considerable malabsorption.
Systemic symptoms include arthritis, sacroiliatis, ankylosing spondylitis, and migraines. Such patients have an increased risk to develop cancer over the years of their illness; however, the risk is not as high as that in ulcerative colitis. Ulcerative colitis is a type of inflammatory bowel disease that is limited to the colon. It involves mucosal and submucosal damage. Unlike Crohn’s disease, this disease spreads proximally from the anus and rectum toward the descending colon, transverse colon, and ascending colon. Aside from the normal symptoms of diarrhea, fever, and fecal blood loss, there are several systemic symptoms such as ankylosing spondylitis, migratory polyarthritis, hepatitis problems, and uveitis. The incidence of ulcerative colitis is higher than that for Crohn’s disease and is more widely distributed. It is thought that the inflammation of the colon is probably caused by regurgitation of iliac contents into the colon by the presence of an abnormal and incompetent ileocaecal valve. The vale links the cecum to the ileum. These conditions can also result in a clinical presentation of appendicitis, because the cecum is close to the appendix. The mucosal involvement is of such a nature that the mucosa bleeds easily, and overt fecal blood loss can lead to dire consequences. Inflammation progressively worsens the condition and the mucosa has a patchy appearance of ulcers alternating with segments of regenerating mucosa that looks like a polyp. Ulcers are rarely serpentine, but damage spreads to the underlying neural plexus of nerves that gets damaged cause a toxic megacolon. This condition could be lethal as loss of the nerves supplying the colon causes cessation of bowel functioning. It cannot be overemphasized that ulcerative colitis leads to epithelial damage that causes epithelial dysplasia and significantly increases the chance of colonic cancer. Clinical symptoms include mucoid bloody diarrhea that may persist invariably. Spasmodic pain generating from the lower left quadrant, spreading throughout the abdomen, is characteristic. The first attack may be the last in lucky patients. Attacks may be triggered by emotional or physical stress. The treatment of inflammatory bowel disease can involve immunosuppressive drugs such as azothiaprine and corticosteroids. Maintenance therapy is done by using antiinflammatory drugs. Such patients are very vulnerable to depression and, therefore, should be encouraged not to be stressed or exert themselves emotionally
Influenza
or physically. In case of a toxic megacolon, surgery is the only option, sealing the rectum and attaching a synthetic colostomy bag for collection of fecal matter. SEE ALSO: Diarrhea; Immunosuppressive Drugs; Inflam-
mation; Psychosomatic Disorders.
Bibliography. Fred Saibil, Crohn’s Disease and Ulcer-
ative Colitis: Everything You Need to Know (Firefly Books, 2003); Ramzi S. Cotran, et al., Robbins Pathological Basis of Disease, 6th ed. (Saunders, 1999). Quratulain Fatima Independent Scholar
Influenza Influenza, or “flu” for short, is a contagious viral disease that affects the respiratory system. The influenza virus is contracted through airborne exposure. It has also been called the grippe, the “sweating sickness” and in the great pandemic of 1918, Spanish fever. Laypeople sometimes confuse influenza with other respiratory infections that are have flu-like symptoms but different causes. Influenza can be contracted by anyone at any age. Influenza viruses are RNA viruses of the family Orthomyxoviridatge. The viruses affect birds and mammals including humans. The disease is usually spread by sneezes and coughs which create an aerosol containing the virus. It can also be spread through blood, feces, nasal secretions, and saliva. Birds infected with influenza virus spread the disease via their droppings. The ������������������������������������������������ disease can remain infectious for sometime. In the human body, it is infectious for about a week. However, birds that carry the disease to the Artic regions can leave infectious droppings that are contagious for a month or more at near-freezing temperatures. Common disinfectants and detergents can be used to kill influenza viruses. There are some few strains that resist this type of prophylactic activity. Influenza can cause illness that ranges from mild to very serious. Specific symptoms are often called “flulike” symptoms. They include fever, chills, headaches, runny or stuffy nose (rhinitis), dry cough (unproductive cough), sore throat, muscle aches (myalgia) that are nonspecific, and general weakness (malaise).
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Stomach symptoms are more common in children than in adults. Symptoms in children can include ear infection (otitis media), nausea, diarrhea, and vomiting. The stomach symptoms are not caused by “stomach flu” which does not exist. The stomach upset is caused by different viruses or by secondary reactions. Generally, people infected with a case of uncomplicated influenza recover in a few days to two weeks. However, the virus may weaken the immune system so that it creates opportunistic infections from bacteria. Pneumonia is a common secondary infection. It may be a secondary infection or caused by a primary influenza viral pneumonia. Other secondary infections are bronchitis and ear infections. Most deaths associated with influenza are due to secondary infections. Annually, between five to twenty percent of the American population catch the flu every year. This number is in the millions with most recovering soon. However, around 200,000 people have to be hospitalized every year and about 35,000 people die from influenza complications every year. The population groups most threatened by influenza are children, those over 65 years of age, and those with chronic health problems. The influenza virus exacerbates their underlying medical condition. Asthmatics and people with cardiac disease such as chronic heart failure are vulnerable because their condition is worsened by the disease. Treatment for the flu includes rest, drinking plenty of fluids, and avoiding the use of tobacco and alcohol. Medications may also be taken. Some such as aspirin seek to control fever. Other medications control aches and pains. Physicians may prescribe antibiotics to combat secondary infections. Antiviral medications may be prescribed to combat the influenza virus. Aspirin can be given to adults as part of the treatment for flu, but it should never be given to children or teenagers unless ordered by a licensed physician. Medicine for relieving symptoms are readily available for children or teens. For them to take aspirin when flu-like symptoms are present is to risk contracting Reye syndrome. This is a rare but very serious illness. Influenza can be spread by physical contact, but is usually contracted from breathing the virus. It spreads from person to person through respiratory droplets (“droplet spread”) beginning one day prior to the development of symptoms to five days after infection. Children can be contagious for seven days or longer.
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Influenza, or “flu” for short, is a contagious viral disease that affects the respiratory system. It can be contracted by people of all ages.
The influenza virus can also be spread if respiratory droplets touch the hands of uninfected people before they wash their hands. They may then transmit the disease to their respiratory system through contact. When the virus is inhaled, it comes into contact with the cells lining the upper air passages. The virus is able to penetrate the cells and to begin its replications. As it reproduces, it spreads to other cells and then to the whole respiratory tract. As breathing occurs, the virus penetrates deep into the lungs and is also expelled into the air where it awaits an opportunity to infect others. Symptoms usually begin from one to four days after infection. Most of the time, the human body develops enough antibodies to defeat the virus. It also develops an immunity against further influenza infections. The body develops cytotoxic T lymphocytes that have the genetic structure necessary to identify and to destroy the influenza virus. However, the influenza
virus undergoes constant changes in its genetic code so that its chemical composition constantly changes. As a consequence, the body may have developed an immunity to an old strain of the virus but not to its new versions. Because deaths from influenza are common especially in the very young, the elderly, and those with weakened immunes systems, vaccinations are promoted by health authorities. The influenza vaccine is made about six months in advance of the oncoming flu season. Vaccines against influenza have been made from either killed or live viruses. Vaccines made from killed influenza viruses have been the most common. However, this type of vaccine has only a limited effectiveness. Research in the 1970s led to the development of live influenza vaccines. These have been more effective in combating the disease. Annual vaccination against flu is the best preventative strategy; however, some antiviral drugs have also been developed. These drugs can also be used to fight the influenza virus because they have a chemoprophylaxis effect. Amantadine, oseltamivir, rimantadine, and zanamivir are the only antiviral agents licensed in the United States. Other antiviral drugs are used in other countries. Like most drugs, all of them carry the possibility of negative side effects. Antiviral drugs used to fight influenza viruses have encountered the development of resistance. Influenza A can quickly develop resistance; however, as the A strain mutates, it can redevelop susceptibility to antiviral drugs. During the 2006–07 flu season, American and Canadian studies indicated that Influenza A had developed resistance to amantadine and rimantadine during treatment. These two antiviral drugs were not recommended by the Centers for Disease Control and Prevention (CDC) until susceptibility was reestablished. Oseltamivir and zanamivir are effective in treating influenza. Oseltamivir can be prescribed to infants and zanamivir can be approved for people 7 years old and older. Oseltamivir is made by Roche Laboratories and marketed as Tamiflu (Oseltamivir Phosphate). In November 2006, the Food and Drug Administration approved a supplement to the possible side effects of the drug. Children taking the drug in Japan were reported as presenting psychiatric behaviors that caused self-injury. Administration of the drug in children now requires several minutes supervision to check for unusual behavioral signs.
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Influenza
Most cases of influenza occur in the winter months in both hemispheres. Beginning in November rising during December and January, the disease usually peaks in February and then begins to recede in March and ends in May. However, it may peak in any of the flu season months. The flu season is not caused by the onset of cold weather as a direct cause. Rather, as the cold weather pushes people to get out of the cold in warm places, they congregate more which allows more opportunities for influenza viruses to spread. The best preventative against influenza is vaccination in the fall prior to the onset of flu season. Vaccines are prepared influenza virus strains that are most likely to be the prevalent strain during the oncoming flu season. ����������������������������������������������� In addition to vaccination, good health habits are very useful in preventing flu. These include avoiding contact, good hygiene, and healthy physical activity. The influenza virus constantly mutates. As a result, its potency varies from year to year. Scientists have categorized influenza viruses into three main types. These are type A, type B, and type C. Types A and C affect many species including humans. Type B seems to affect only human beings. Type A influenza is the most virulent of the three strains. It has been subdivided into categories based upon its responses to different antibodies and it pandemic potential. Type A strain, H1N1 (Spanish flu), H2N2 (Asian flu), H3N2 (Hong Kong flu), H5N1 (potential pandemic in 2007), H7N7, H1N2 endemic in humans and pigs, and H9N2, H7N2 H7N3 and H10N7. The type A influenza viron is not a single genetic string of nucleic acid. It has eight segments that can perform different chemical reactions. Type B influenza affects only humans and possibly seals. Most people are exposed to the strain at an early age and develop a limited immunity. Type C influenza is less common than the other two types. However, it causes local epidemics. Swine and birds are carriers of influenza viruses. Birds may be the main reservoir of influenza stains. They can in some cases transmit the virus to each other where it undergoes genetic modification. In some cases, the genetic modifications allow the virus to infect human beings. Strains of flu are usually named for the location in which they are first identified. Or they may be named after the species in which a new strain was first found such as bird flu, swine flu, human flu, horse flu.
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Influenza is a global disease that travels rapidly. It may be carried by migrating birds that then communicate it to other species and then to humans. Outbreaks occur annually, spreading around the world through contact with travelers. Great number of people are sickened every year with a large annual death toll. Economic losses from lost wages and healthcare costs are very large. As influenza strains mutate, they can cause pandemic outbreaks in which there are great losses of life. The Spanish flu or the Great Influenza outbreak occurred in winter of 1918–19. Over 500,000 Americans died. Deaths globally were over 20 million people. Global deaths may have been much higher. There were two other influenza pandemics in the twentieth century. Each killed millions of people. In 1956–57, the Hong Kong flu caused a great many deaths. Pandemics are difficult to predict nor is it possible to predict how severe they may be. However, if one starts, the whole world is at risk. Countries that close their borders are simply delaying the inevitable. In a human pandemic, millions will die and the economic losses will be enormous. In the 1990s, a new strain of flu appeared in Asia, the deadly avian strain called H5N1. So far, very few humans have been infected, but the number is growing. Of those infected, half died. Exposure to infected poultry is the suspected as the source of contraction of the disease. The H5N1 strain has spread throughout Asia and Africa as birds migrate annually. Its appearance in the Americas is expected because of contact between birds around the Artic Circle between Asian and American bird flocks. The concern of health officials is that bird flu will interact with swine flu and then be genetically modified so that it become contagious to humans. Human-to-human contagion will then become a pandemic. See Also: Epidemic; Infectious Diseases (General); Respi-
ratory Diseases (General).
BIBLIOGRAPHY. John M. Barry, The Great Influenza:
The Epic Story of the Deadliest Plague in History (Viking Penguin, 2005); Alfred W. Crosby, America’s Forgotten Pandemic: The Influenza of 1918 (Cambridge University Press, 2003); Michael Greger, Bird Flu: A Virus of Our Own Hatching (Lantern Books, 2006); Influenza—
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a Medical Dictionary, Bibliography, and Annotated Research Guide to Internet References (ICON, 2004); Roy Jennings and Robert C. Read, Influenza (Royal Society of Medicine Press, 2000); Daniel Kalla, Pandemic (Tor Books, 2005); Y. Kawaoka, Influenza Virology: Current Topics (Caister Academic Press, 2006); Gina Bari Kolata, Flu: The Story of the Great Influenza Pandemic of 1918 and the Search for the Virus that Caused It (Simon & Schuster, 2001); Robert M. Krug, Influenza Viruses (Springer-Verlag, 1989). Andrew J. Waskey Dalton State College
Inhalants Inhalants are toxic substances found in common household products such as spray paint, glue, nail polish remover, and cleaning fluids. These substances produce breathable chemical vapors, which are inhaled to produce mind-altering effects. Inhalants are often used as a substitute for alcohol with effects that mimic acute alcohol intoxication. Most inhalant abusers are younger than 25 and are often unaware of the dangers associated with inhalant use, which include organ damage and possible death. Education, early identification, and intervention are necessary to stop inhalant abuse before it causes serious consequences. Inhalants are easily available, inexpensive, and difficult to detect, resulting in widespread potential for abuse among children and teenagers in both urban and rural areas. Inhalant abuse is most common in the south and southwestern United States and among Native American children. Poverty, a history of sexual or physical abuse, and poor grades have all been associated with an increased risk of inhalant abuse. Government surveys have shown that inhalant abuse typically peaks between the seventh and ninth grades and results from the 2006 Monitoring the Future study indicate that 29.2 percent of eighth graders report lifetime use of inhalants. Inhalants include large variety of substances such as solvents (e.g., gasoline, paint thinner, glue, felttip marker, correction fluid), aerosols (e.g., spray paint and hair spray), and gases (e.g., butane light-
ers, ether, halothane, nitrous oxide) that have varying pharmacological effects. Inhalants can be abused in many different ways including inhaling nitrous oxide from balloons, spraying aerosols directly into the mouth, “sniffing” which describes direct inhalation of fumes from containers, “bagging” which involves inhalation of solvents from a plastic or paper bag, and “huffing” which describes inhaling vapors from a cloth soaked in solvent that is held close to, or stuffed inside of, the mouth. Most inhalants produce rapid euphoria and central nervous system depression. This resembles acute alcohol intoxication, with drunken appearance, slurred speech, disorientation, nausea, and vomiting. Inhalant abusers are also likely to have chemical odors or paint stains on their face, hands, or clothing. Research from animals and humans show that inhalants are extremely toxic and hazardous to health. High concentrations of certain inhalants, such as butane, can induce rapid and irregular heart rhythms that may progress to heart failure and death within minutes, a syndrome described as “sudden sniffing death.” Inhalants can also lead to death through suffocation and asphyxiation. Chronic use of inhalants can cause organ damage to many structures including the brain, heart, liver, lungs, and kidneys. Although inhalants are not regulated under the Controlled Substances Act, they have a high potential for abuse and many state legislatures have passed laws restricting the sale of products such as spray paint and glue to minors. Adults should be aware of the temptations that inhalants pose to children and store household products carefully to avoid accidental ingestion or intentional abuse. SEE ALSO: Adolescent Health; National Institute on Drug
Abuse (NIDA).
Bibliography. Jerrold S. Meyer and Linda F. Quen-
zer, Psychopharmacology: Drugs, the Brain, and Behavior (Sinauer, 2004); National Institute on Drug Abuse, “Info Facts: Inhalants,” www.drugabuse.gov (cited January 2007); National Institute on Drug Abuse, “NIDA Community Drug Alert Bulletin: Inhalants,” www.drugabuse.gov (cited January 2007). Bernadette Mietus Stevenson, M.D., Ph.D. University of North Carolina
Inpatient
Innate Immunity An inflammatory response is the body’s reaction to tissue damage or infection by foreign substances. It is a complex phenomenon composed of two very distinct types of immunity: innate and acquired. In innate immunity, the body utilizes natural and physiologic barriers to initiate cellular repair, to protect itself from invasion, and to attempt to limit the spread of pathogen through activation of a complex inflammatory cascade. The natural barriers of innate immunity include the skin, mucous membranes, hair, and the acidic environments of the stomach and sweat. Examples of the physiologic responses include the coughing reflex, the release of antifungal and antibacterial secretions from skin glands, the beating of respiratory cilia, the production of hydrolytic enzymes in tears and saliva, the production of chemical signals known as cytokines, and the stimulation of specific innate cellular components which aid in the fight against infection. Effective innate immunity does not rely on previous interaction with the pathogen and is therefore a nonspecific cellular immunity. Phagocytosis, characterized by host cell migration, recognition, attachment, engulfment, and processing of pathogens, is the main mechanism of innate immunity. In this process, host cells are protected from invasion and attempt to control the spread of a pathogen. The primary cells involved are neutrophils and macrophages. Neutrophils are considered the first responders during inflammation and are often replaced by macrophages arriving at the exposure site within 48 hours. Activation of this process often follows exposure of the body to specific bacterial components, like lipopolysaccharide (LPS), a polysaccharide on certain bacterial cell membranes. The body also responds to bacterial peptides, membrane components like peptidoglycan and techoic acid, and foreign nucleic acids. Each of these substances contains unique sequences known as pathogen-associated molecular patterns, or PAMPs, that the body recognizes as foreign. The body possesses its own recognition machinery in the form of toll-like receptors, or TLRs, found on host innate immune cells, and these are used to recognize and bind these PAMPS. Initiation of downstream cellular responses then occurs and leads to the production of exudate and specific chemi-
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cal messages such as interferon, interleukins 1 and 6, and tumor necrosis factor. Another process by which host cells are protected from invasion and attempt to control the spread of a pathogen is via complement activation. A complement is an immune complex comprised of three activating pathways: the leptin pathway, the alternative pathway, and the classical pathway, all of which allow for the destruction of the invading pathogen. The typical signs and characteristics of the innate immune response include heat, redness, swelling, pain, and loss of function. The heat and redness accompany vascular dilatation while swelling is the result of the escape of fluid, plasma protein, and cellular accumulation within the area of exposure. Pain results from released chemical mediators and nerve compression. The severity of the pathogen, the immune status of the host, and the site of exposure determine the intensity of each symptom. Without such a complex response, the body would be unable to effectively fight off infection and disease. SEE ALSO: Acquired Immunity; Immunology. Bibliography. Stefan H.E. Kaufmann, Ruslan Medzhitov,
and Siamon Gordon, eds., The Innate Immune Response to Infection (ASM Press, 2004).
Melissa K. Wolinski Michigan State University
Inpatient An inpatient is someone staying at a hospital for one or more nights while undergoing medical treatment. The word comes from the term patient which is derived from the Latin word patiens, which refers to enduring or suffering. The adjective patient from the word patience comes from the same origin, but obviously, has a different meaning. A hospital is the medical facility where patients can be treated overnight, as opposed to a clinic or medical center, where this is generally not possible. As a result, an inpatient is officially defined as someone who goes to the hospital with a serious ailment or condition, and needs to stay overnight or until he or she recovers. This
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may be for several days or weeks; in extreme cases, such as with coma patients, stays can last decades. In emergencies, patients are admitted immediately. Visitors to emergency rooms are generally seen quickly, with an immediate report of the patient’s condition made. Staff in the emergency room determines the urgency of the patient’s need for medical treatment. Depending on these decisions and the number of patients waiting for emergency treatment, there can be a wait before a given patient is formally admitted. At this point, medical professionals determine whether or not the patient can be treated and released or will need a more prolonged stay for treatment, rest and recovery, or because of the patient’s home situation; in some cases, a patient may be admitted because of the inability to return home or the need to notify family members. If it is determined that the patient will be staying at the hospital for at least one night, the patient’s status becomes “inpatient.” Hospital staff must then find an available bed, either at their hospital or at another nearby facility. Patients awaiting an operation, those recovering from a fall or accident, and those recovering from medical procedures are classified as inpatient until they have recovered sufficiently to allow a return home. Patients who arrive at the hospital for a planned medical procedure are generally classified as inpatient as well. Upon discharge from a hospital, a person ceases to be an inpatient. SEE ALSO: Outpatient. Bibliography. Sanjay Saint, The Saint-Frances Guide
to Inpatient Medicine, 2nd ed. (Lippincott Williams & Wilkins, 2003).
Justin Corfield Geelong Grammar School, Australia
Institute for Children’s Environmental Health (ICEH) The Institute for Children’s Environmental Health (ICEH), founded in 1999, is a nonprofit educational organization working to ensure a healthy, just, and sustainable future for all children. ICEH’s primary goals center around coordinating effective, collab-
An inpatient is someone staying at a hospital for one or more nights while undergoing medical treatment.
orative strategies among the varied environmental health-focused organizations and institutions in order to mitigate duplicative efforts and diffuse tension over jurisdictional issues, and promoting a projectbased environmental health and justice program to be introduced into existing youth forums and schools in order to educate and activate the next generation on environmental health and justice concerns. To support its mission, the ICEH is committed to creating long-term partnerships with other organizations and institutions to build a more effective and collaborative environmental health movement. The Institute also works with health-affected constituencies, in particular learning and developmental disabilities organizations, to educate their members about possible environmental links to various health problems and to nurture their capacity to advocate for policies that protect children from neurotoxicants. Additionally, the ICEH supports policies and actions based on preventive, transparent, democratic, and precautionary practices to ensure that children’s unique susceptibilities to environmental exposures are being addressed. The ICEH has been involved with a number of national programs and initiatives, including the Learn-
ing and Developmental Disability Initiative (LDDI), a national network of organizations and individuals interested in collaborating on research, educational and policy initiatives that reduce exposures to pollutants that may undermine healthy brain development. The LDDI is a working group of the Collaborative on Health and the Environment (CHE) and members include researchers, health professionals, learning and developmental disabilities organizations, and environmental health and justice groups. The Partnership for Children’s Health and the Environment, a growing coalition of over 270 organizations and leaders in government, academic, and community-based sectors in North America, is committed to sharing information and incubating new collaborative initiatives on children’s environmental health issues. The Healthy Futures Project is a project-based program on environmental health and justice for youth in the Pacific Northwest. This program fosters both scientific thinking and creative expression to inspire youth to serve as change agents for a healthy future, and also focuses on educating students with learning disabilities about environmental health issues. The ICEH also regionally coordinates the Collaborative on Health and the Environment–Washington (CHE-WA), a regional project of national CHE. CHE-WA is a network of over 310 researchers, health-affected groups, healthcare practitioners, environmental health and justice advocates, and other concerned citizens committed to reducing environmental contaminants for a healthier future. The Institute sponsors an annual meeting as well as regional gatherings throughout the country. Its advisory board includes some of the country’s leading professionals in the various fields of children’s health. The principle funding for the ICEH comes from the Tides Center, a nonprofit foundation dedicated to positive social change, innovation, and environmental sustainability. SEE ALSO: Environmental Health; Pediatrics. Bibliography. American Academy of Pediatrics, www.
aap.org (cited September 2006); Ruth Eztel, ed., Pediatric Environmental Health (American Academy of Pediatrics, 2004); Natalie Freeman and Dona Schneider, Children’s Environmental Health: Reducing Risk in a Dangerous World (American Public Health Association, 2000); Institution
Institute of Medicine (IOM)
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for Children’s Environmental Health, www.iceh.org (cited September 2006); Tides Center, www.tidescenter.org/ index_tc.cfm (cited September 2006). Ben Wynne, Ph.D Gainesville State College
Institute of Medicine (IOM) Founded in 1970 as part of the National Academy of Sciences, the Institute of Medicine (IOM) is a nonprofit organization charged with working as an advisor on ways to improve health. In that capacity, the Institute provides unbiased, evidence-based, and authoritative information and advice concerning health and science policy to legislators, professionals, leaders in every sector of society, and the public at large. The Institute’s work centers principally on committee reports or studies on subjects ranging from the national smallpox vaccination program to protecting the nation’s food supply. The IOM’s principle concerns are organized into 17 topic areas: mental health, child health, food and nutrition, aging, women’s health, education, public policy, healthcare and quality, diseases, global health, workplace, military and veterans, health sciences, environment, treatment, public health and prevention, and minority health. The Institute also convenes roundtables, workshops, and symposia that provide an opportunity for public and private sector experts to discuss contentious issues in an open environment that facilitates evidence-based dialogue. The majority of the Institute’s studies and other activities are requested and funded by the federal government. Private industry, foundations, and state and local governments also initiate studies, as does the IOM itself. The objective in all of the Institute’s work is to improve decision making by identifying and synthesizing evidence relative to the deliberative process. The IOM is regularly recognized through its projects as a national resource of judgment and veracity in the analysis of issues relating to human health. Depending on the request, studies by the Institute may be designed to answer very specific and technical questions, or they may be broad-based examinations that
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span multiple academic disciplines, industries, and international borders. The IOM is organized into eight oversight boards: Board on African Science Academy Development (joint with the National Research Council [NRC]); Board on Children, Youth, and Families (joint with NRC); Food and Nutrition Board; Board on Global Health; Board on Health Care Services; Board on Population Health and Public Health Practice; Board on Health Sciences Policy; and Board on Military and Veterans Health. In developing a board’s membership, the IOM seeks to have expertise in the various relevant disciplines and in subject matter areas that are in the board’s portfolio of studies or other activities. In addition, the organization seeks diversity, academic distinction, and geographic balance. The Institute publishes the IOM News, a free, bimonthly e-mail newsletter for its members through which it announces new IOM publications, upcoming events, and general information related to the organization’s mission. The IOM headquarters is in New York City. SEE ALSO: National Institute of Health (NIH). Bibliography. Board on African Science Academy Devel-
opment, www7.nationalacademies.org/africa/index.html (cited October 2006); Board on Children, Youth, and Families, www7.nationalacademies.org/bocyf (cited October 2006); Board on Military and Veterans Health, www.iom. edu/CMS/26761.aspx (cited October 2006); Institute of Medicine (IOM), www.iom.edu (cited October 2006); The National Academies, www.nationalacademies.org/nrc (cited October 2006); National Institutes of Health (NIH), www.nih.gov (cited October 2006). Ben Wynne, Ph.D. Gainesville State College
Institutional Review Board (IRB) Under Food and Drug Administration (FDA) regulations, an institutional review board (IRB) is an appropriately constituted group that has been formally designated to review and monitor biomedical
research involving human subjects. In accordance with FDA regulations, an IRB has the authority to approve, require modifications in (to secure approval), or disapprove research. This type of review serves an important role in the protection of the rights and welfare of human research subjects. The purpose of IRB review is to assure, both in advance and by periodic review, that appropriate steps are taken to protect the rights and welfare of humans participating as subjects in various types of research. To accomplish this mission, IRBs use a group process to review research protocols and related materials such as informed consent documents and investigator brochures. While IRB is a generic term used by the FDA to refer to a group whose function is to review research to assure the protection of the rights and welfare of human subjects, institutions under review may use whatever name they choose. An IRB is subject to the FDA’s IRB regulations when studies of agency-regulated products are reviewed and approved. Although institutions engaged in research involving human subjects will usually have their own IRBs to oversee research conducted within that specific institution or by the staff of the institution, FDA regulations permit an institution without a board to arrange for initial and continuing review through the use of an “outside” IRB. Individuals conducting research in a noninstitutional setting often use established IRBs (either independent or institutional) rather than creating their own. While research that has been reviewed and approved by an IRB may be subject to further review or even disapproval by officials of the institution, those same officials may not approve research if it has been disapproved by the IRB. Federal policy dictates that IRBs must have at least five members with varying backgrounds to promote a complete review of research activities commonly conducted by an institution. The IRB members must be sufficiently qualified through experience, expertise, and diversity of background, including considerations of racial and cultural heritage and sensitivity to issues related to community attitudes. The United States Department of Health and Human Services, Office of Human Resource Protection (OHRP) sponsors a series of workshop on responsibilities of researchers, IRBs, and institutional officials for the protection of human subjects in research. These
Insurance
conferences are open to everyone with an interest in research involving human subjects. SEE ALSO: Department of Health and Human Services
(DHHS); Food and Drug Administration (FDA).
Bibliography. The Institutional Review Board—Discus-
sion and News Forum, www.irbforum.org (cited October 2006); Robert J. Levine, Ethics and Regulation of Clinical Research, 2d ed. (Urban and Schwarzenberg, 1986); Dennis M. Maloney, Protection of Human Research Subjects: A Practical Guide to Federal Laws and Regulations (Plenum, 1984); The Poynter Center for the Study of Ethics and American Institutions, http://poynter.indiana. edu (cited October 2006); United States Department of Health and Human Services, Office of Human Resource Protection, www.hhs.gov/ohrp/irb/irb_guidebook.htm (cited October 2006). Ben Wynne, Ph.D. Gainesville State College
Insurance Unpredictable illness creates an uncertain need for health services. The institutional response to this uncertainty is to create an insurance mechanism in which participating individuals contribute regularly to a riskpooling agency that provides reimbursement in the event of an illness. The insuring organization can be public or private, the contribution can be via premiums or taxes, and the reimbursement can be monetary or through direct provision of medical services. Risk-averse individuals are willing to pay a premium to an insuring agency to avoid taking on risk. This premium is typically far more than the average loss they are likely to confront since the sum of these collected premiums from the insured pool must at least cover the expected benefits the insurance agency expects to pay out, their administrative cost, along with their profit. Three basic challenges to this model have been studied extensively: consumer information issues, moral hazard, and adverse selection. Consumers in the healthcare market are confronted with the lack of easily available price, paucity of quality information, and the challenge of interpreting complex
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and technical medical information. These issues can limit the ability of the individual to make rational and informed decisions about medical insurance. Moral hazard is neither a moral dilemma nor is it necessarily hazardous. Instead, it is a rational consumer’s predictable response to a reduction in the price of health services, resulting from participation in an insurance plan. The insurance plan reduces the outof-pocket cost to the individual for medical services, inducing individuals to consume care that is of less value than the cost of providing that care. In the most extensive controlled experiment on health insurance, the RAND Corporation, a nonprofit research organization, and associated researchers found that being insured increased the likelihood of purchasing medical services and increased the spending amount in the event of an illness. Insurance companies have introduced deductibles and coinsurance to limit the extent of moral hazard by having the individual feel some level of financial burden. The insurance deductible is a set monetary amount that must be incurred by the insured before the insurance company pays any part of the claim. A policy with coinsurance requires the individual to pay a fixed percentage of every claim, and this cost sharing typically ends after total out-of-pocket spaending reaches some limit. Such solutions allow a balancing between the reduction in financial risk and the effects of increased demand for care. The third concern is that of adverse selection, whereby the purchasers of insurance have more information about their expected healthcare needs than the insuring organization. Individuals have the ability to conceal their true risk. If enough high-risk individuals conceal themselves as low-risk purchasers, the premiums set by the insurance agency based on actuarial projection will underestimate the expected benefits that will need to be paid out. This will lead to higher-than-average premiums for the pool of individuals and create an incentive for lowrisk individuals to drop out of the pool, driving up premiums even more. These even-higher premiums would drive out more low-risk individuals at the margin, driving premiums even higher. This so-called “death spiral” is prevented by insurance companies by only underwriting prospective risk, and thereby not insuring for preexisting conditions. In addition, they can risk rate
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prospective customers via having them complete a questionnaire or have a physical exam. In essence, if the insurance agency could identify low- and highrisk individuals, and charge premiums accordingly, then the problem of adverse selection could be averted. Pooling risk through a third-party mechanism such as an employer also serves to mitigate adverse selection. Alternatively, in a national health insurance program, there is no concern for adverse selection because everyone is covered. Systems of Health Insurance Worldwide Countries have taken many different approaches to providing health insurance, and many have been able to successfully provide universal health coverage, that is, insurance to all individuals within a geographic or political entity. This list includes Argentina, Australia, Austria, Belgium, Canada, Cuba, Denmark, Finland, France, Germany, Greece, Ireland, Israel, Italy, Japan, the Netherlands, New Zealand, Norway, Portugal, Russia, Saudi Arabia, South Korea, Spain, Sri Lanka, Sweden, Taiwan, and the United Kingdom. A notable exception from this list is the United States, where over 46 million individuals are uninsured. While each country is unique in its system, below is a brief description of a few countries to provide a flavor of the variety of different mechanisms that have been employed. The type of insurance coverage, the payers, and the nature of the providers are highlighted. Canada National health insurance in Canada, known as Medicare, is a public program administered by the provinces and overseen by the federal government. This singlepayer system run by the government is supported by general tax revenues. Federal contributions are linked to population and economic conditions of the provinces, with provinces left to pay the remaining amount. Medicare accounts for 72 percent of total healthcare expenditures, while a majority of Canadians have supplemental private insurance accounting for the remaining 28 percent. A majority of Canadian physicians are in private practice and accept fee-for-service rates set by the government through negotiations with provincial health ministries. More than 95 percent of hospitals are nonprofit, operating under a regional budget with limited fee-for-service payments.
Medicare is a program in the United States providing coverage to people over 65, and is funded by taxes and enrollee premiums.
Germany The national health insurance program of Germany is paid for by Sickness Insurance Funds (SIFs), quasigovernmental groups that serve as insurance companies in terms of collecting premiums, negotiating rates, and paying providers. SIFs are funded by compulsory payroll contributions, an average of 14 percent of wages, equally shared between employers and employees. SIFs cover 92 percent of the population and account for 81 percent of health expenditures. The remaining 8 percent are the affluent self-insured, the self-employed, and civil servants, who are all covered by private insurance based on voluntary, individual contributions. General practitioners do not serve as gatekeepers to specialists, and are paid on a fee-for-service basis. United Kingdom The medical system of the United Kingdom, known as the National Health Service (NHS), handles both
healthcare delivery and healthcare financing. In other words, the government is the purchaser and provider of healthcare. The NHS, funded through general taxation, accounts for 88 percent of health expenditures. Complementary private insurance, provided by both for-profit and not-for-profit insurers, covers 12 percent of the population and accounts for four percent of total expenditures. Physicians are paid directly by the government via salary, capitation, and fee-for-service mechanisms. They serve as gatekeepers to specialists. Hospitals are self-governing public trusts that contract with groups of purchasers on a long-term basis. United States The healthcare system of the United States is a combination of private insurance coverage based primarily on employment, and three major public insurance programs: Medicare, Medicaid, and Veterans Affairs. Medicare is a federal government program providing coverage to people age 65 or older, and is funded by payroll taxes, income taxes, trust fund interest, and enrollee premiums. Ninety percent of this funding comes directly or indirectly from individuals who are younger than 65 years old. Medicaid is a means-tested entitlement program administered by the states, jointly financed with the federal government. U.S. military veterans and current servicemen and servicewomen are provided care directly through a nationwide network of government hospitals organized by the Department of Veterans Affairs. Fifteen percent of the U.S. population is covered by public insurance, 5 percent by private nongroup, and 62 percent by employer-sponsored insurance. This leaves 18 percent uninsured, amounting to more than 46 million individuals without insurance in the United States. SEE ALSO: World Health Organization (WHO).
J.W. Henderson, Health Economics and Policy (South-Western, 1999); W.G. Manning, et al., “Health Insurance and the Demand for Medical Care: Evidence from a Randomized Experiment,” American Economic Review (v.77/3, 1987); M.V. Pauly, “The Economics of Moral Hazard,” American Economic Review (v.58/3, 1968); Thomas Rice, The Economics of Health Reconsidered (Health Administration Press, 1998); R.J. Zeckhauser, “Medical Insurance: A Case Study of the Trade-Off beBibliography.
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tween Risk Spreading and Appropriate Incentives,” Journal of Economic Theory (v.2/1, 1970). Ashwinkumar Patel Wharton School of the University of Pennsylvania
Internal Medicine Internal medicine is a special branch of conventional medicine that treats diseases of the internal organs of the body. Physicians who become doctors of internal medicine are physicians who train to be doctors for adults. Called internists, “general internists,” and “doctors of internal medicine,” they are not interns, nor family physician, family practitioners, or general practitioners. General practitioners may have medical training in surgery, obstetrics, pediatrics, or other specialties that are not focused exclusively on adult care. The practice of internal medicine developed in Germany in the late 1800s when physicians combined laboratory medical science with the care of patients. Americans studying medicine in Germany brought the specialty to the United States. In the United States at the beginning of the 21st century, primary care for adults is provided by either by physicians engaged in family practice or as general internal medicine physicians. There is some overlap between internists and family practice and pediatricians because all three give care to adolescents. Physicians who become internists are internal medicine specialists. As internists, they have a specialty in some aspect of medicine affecting the internal systems of the body. They specialize in medicine focused on the diseases experienced from young adult years into old age. Their specialized training is focused on the prevention and treatment of adult medicine. Internists have either an MD (medical doctor) degree or a DO (Doctor of Osteopathy) degree. Their training is certified by either the American Board of Internal Medicine or by the American Osteopathic Board of Internal Medicine for physicians practicing in the United States. In other countries, other certification agencies are used and the qualifications may differ.
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Internal Medicine
Qualifications needed to be satisfied to become a doctor of internal medicine include a basic medical degree, internist training, and three or more years of study and practice in a internal medicine specialty. Specialties in internal medicine include allergy, cardiology, endocrinology, gastroenterology, genetics, geriatrics, hematology, immunology, infectious diseases, metabolism, molecular medicine, nephrology, neurology, oncology, pulmonology, and rheumatology. The goal of internal medicine is to prevent adult disease or to cure them. Internists are sometimes called “doctors’ doctors” because they may serve as consultants to other physicians in solving diagnostic puzzles. The internist is a personal physician who establishes a long-term relationship with a patient to provide comprehensive care lasting over the lifetime of the patient. Whether in a routine examination or in a clinical setting that is focused on the management of a chronic disease such as diabetes, the internist provides care that will educate the patient as well as provide treatment for the immediate ailment of the patient. Internists are trained to deal with any medical problem that a patient brings. It may be that the problem is common or it may be rare. It may be simple or complex, but it is of concern of the internist to solve diagnostic problems that are acute or chronic. In addition they are equipped with the knowledge to also understand and to treat cases where a combination of different diseases strike simultaneously. Internal medicine is also sufficiently broad in scope to deal not only will illness but also with wellness. Part of their medical advice may be to educate patients in their own self-care that will prevent disease and promote health. In the modern medical environment, the focus of internists in on caring for patients throughout the adult life cycle. This includes examinations in their office or in a clinic. It also includes care in times of hospitalization, intensive care and in nursing homes in the last stages of life. Care for women, for those with mental health problems, and for those with substance abuse problems are within the realm of internists. Also they are equipped to deal effectively with other problems such as problems of the eyes, ears, skin, nervous system, and the reproductive organs.
If the patient needs the care of other medical specialists such as obstetricians or surgeon, then physicians practicing internal medicine will coordinate with others in dealing with the needs of the patient. They care for and manage all medical problems connected with the care of the patient during the illness, including the hospitalization. Knowledge of internal medicine is used by internists during physical examination to identify abnormalities that are indicators of disease. Picking up symptoms during the diagnostic process to add to the patient’s medical history is used to evaluate the patient’s health or diseased conditions. Specifically, internists review the different internal systems of the patient—pulmatory system, digestive system, and the other systems to identify symptoms that are indications of disease. A review of the patient’s internal systems that identifies symptoms of disease is more likely to be successful if it follows a structured pattern. Otherwise symptoms may be missed. For example, in men, prostatitis is a common occurring infection of the prostate gland. It is caused by a bacterial infection most often. It causes inflammation and will be indicated by an abnormal white blood cell count as well as pain in the prostate. In cases of chronic prostatitis, the symptoms will be more severe and require more radical remedies. Generally, a course of antibiotics will eliminate the infection, but the internist in a long-term relationship with the patient will be able to track the symptoms to that the patient’s problem is eventually solved. Urine tests, blood tests, medical imaging, and other tests can be used to rule other possible diseases or confirm their presence. These tests are sometimes called screening tests. They may include X-rays, white blood cell counts, red blood cell counts, electrolyte tests, renal function tests, enzyme test, or blood gas tests. Other tests can be used including biopsies for microbiological cultures. For example, Whipple’s disease, which is a malabsorption disease caused by a bacterial infection, can be definitively diagnosed by a biopsy of the jejunum area of the small intestines. Cancer can be identified by a biopsy taken by an internist who specializes in oncology. The biopsy can read by a pathologist and the specific type of cancer identified. This will allow specific treatment to be made. Globally, internal medicine is practiced as the primary form of medicine used to treat the majority of
International Agency for Research on Cancer (IARC)
diseases. Internists have joined together in a number of organizations to improve the quality of their education, and the quality of the care they deliver. For example, the International Society of Internal Medicine was founded in 1948. It has since become an international association composed of over 60 national societies of internal medicine. See Also: Allergy; Cardiology; Endocrinology; Gastroen-
terology; Genetics; Geriatrics; Hematology; Immunology; Infectious Diseases (General); Nephrology; Neurology; Oncology; Pulmonology. BIBLIOGRAPHY. Steven S. Agabegi, et al., Step-up to Inter-
nal Medicine (Lippincott Williams & Wilkins, 2004); Steven A. Haist, Leonard G. Gomella, and John B. Robbins, Internal Medicine on Call (McGraw-Hill, 2005); Dennis L. Kasper, et al, Harrison’s Principles of Internal Medicine (McGraw-Hill, 2004); Raminder Nirula, Internal Medicine (Lippincott Williams & Wilkins, 2006); Eugene C. Toy, et al., Case Files: Internal Medicine 2007 (McGrawHill, 2007); James S. Winshall, and Robert Lederman, Tarascon Internal Medicine & Critical Care Pocketbook (Tarascon, 2006). Andrew J. Waskey Dalton State College
International Agency for Research on Cancer (IARC) The International Agency for Research on Cancer (IARC) is part of the World Health Organization (WHO), the United Nation’s agency dedicated to global health. Located in Lyon, France, the IARC focuses on four goals: monitoring global cancer occurrences; identifying causes of cancer; determining how carcinogens interact with human DNA; and developing scientific strategies to control cancer through prevention and early detection. Although the IARC studies the connection between human cancers and the environment, the agency does not attempt to influence carcinogenrelated political legislation. The IRAC was founded on May 20, 1965, by the governments of Germany, France, Italy, the United Kingdom, and the United States at the Eighteenth World
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Health Assembly. The initial goal was to promote international collaboration in cancer research; working languages were established as English and French, with speeches in those languages also translated into Russian. Although logistic matters needed a vote, issues considered purely scientific were not subject to a vote and each scientist could express his or her opinion. Globally, in 2000, there were 10.1 million new cases of cancer diagnosed, 6.2 million deaths and 22.4 million people living with cancer. This represents a 19 percent increase in incidence and an 18 percent increase in mortality since 1990. The IARC works to identify the causes of cancer so that medical researchers can parlay IARC research into studies for cancer prevention, treatments and cures. They believe that 80 percent of all cancers are connected to environmental factors and are therefore preventable; many cancers appear in varying degrees in different geographies and/or populations, and the IARC often focuses its research efforts on uncovering environmental factors that contribute to these patterns and their accompanying mortality rates. The agency studies environmental risk factors, including exposure to chemicals and biological agents, providing this information to national health agencies attempting to reduce or prevent human exposure to carcinogens. Scientists from a number of disciplines analyze published IARC studies to determine how to rank a particular risk factor. Since 1971, they have reviewed more than 900 such factors, identifying approximately 400 as either carcinogenic or potentially so. The IARC divides substances under study as Category 1 (carcinogenic to human); Category 2A (probably carcinogenic to humans); Category 2B (possibly carcinogenic to humans); Category 3 (not classifiable as to carcinogenicity in humans); and Category 4 (probably not carcinogenic in humans). The agency has monitored the “cancer burden” caused by the nuclear leak in the Chernobyl power plant in the Ukraine. IARC scientists project 16,000 cases of thyroid cancer and 25,000 of other types of cancer by 2065 (the 80th anniversary of the nuclear fallout), with an estimated 16,000 deaths from these incidents of cancer. Three particular forms of cancer that garner IARC focus are breast cancer, cervical cancer, and oral cancer. In many countries, breast cancer is the most common form for women, with increasing incidences in
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International AIDS Vaccine Initiative (IAVI)
Africa and Asia. Although, in the United States and other developed countries, mammogram screenings are successfully used as early detection tools, this technology is too expensive and therefore not a feasible strategy in developing countries. The IARC is therefore attempting to institute more practical early detection strategies in these countries. Similar concerns exist over cervical cancer, a disease that kills more than 288,000 women annually, worldwide, with 80 �������������������������������������� percent������������������������������� or more of these deaths occurring in poor areas of South Asia, sub-Saharan, and Latin America. The IARC goal is to develop strategies that help women obtain the relatively simple cervical cancer screening tests in vulnerable parts of the world so that prognoses for these women are more favorable. Oral cancer, which is becoming more prominent in Europe, Japan, and Australia, is also a focus of the IRAC, with early screening a top goal. Agency scientists also study diet and other lifestyle factors in connection with increased cancer risks. Recent IARC studies have confirmed increased colorectal cancer risk with diets heavy in red meat, and reduced risk with diets of fish. Although increased consumption of fruits and vegetables seems to prevent many cancers and other diseases, no link was found to breast cancer prevention. One specific focus of IARC research is to identify how carcinogens work to mutate human genes that normally suppress tumors. Through this process, researchers learn more about the biology of cancer and they identify optimal points when intervention can prevent cancer development. The IARC created an online bookstore to disseminate information and they maintain a Cancer Epidemiology Database that lists occurrences of cancer, worldwide. Starting in 1997, the IARC began publishing a series (10 in all) of IARC Handbooks of Cancer Prevention, to evaluate the effectiveness of preventative strategies. Topics range from mammograms to the consumption of fruits and vegetables to weight control and physical activity. The agency has awarded more than 500 fellowships since 1966 to scientists learning cancer research techniques and strategies. They estimate that 85 percent of these scientists return to their home countries to continue their work; approximately 82 percent of the fellows remain active in cancer research efforts. Postdoctoral fellowships are available to scientists who reside in countries with low- or medium-resource levels.
Besides the founding members, the following nations have joined the IARC: Australia (1965), Belgium (1970), Canada (1982), Denmark (1990), Finland (1986), India (2006), Japan (1972), Korea (2006), Netherlands (1987), Norway (1987), Russian Federation (1965), Spain (2003), Sweden (1979), and Switzerland (1990). In 2006, Lars Erik Hanssen of Norway was elected chair of IARC. He lists two priorities: closer study of the hepatitis B vaccine’s preventative impact on liver cancer in Gambia and an examination of the links between alcohol consumption and cancer. SEE ALSO: American Cancer Society (ACS); Cancer
(General); National Cancer Institute (NCI); World Health Organization (WHO).
Bibliography. American Cancer Society (ACS), www.
cancer.org (cited December 2006); Vincent James Cogliano, et al., “The Science and Practice of Carcinogen Identification and Evaluation,” Environmental Health Perspectives (v. 113/12, 2004).
Kelly Boyer Sagert Independent Scholar
International AIDS Vaccine Initiative (IAVI) The International AIDS Vaccine Initiative (IAVI) is an international nonprofit organization founded in 1996 to promote HIV vaccine development. While other international coalition groups such as the Global Fund also work to treat and prevent infectious diseases, IAVI is the main international organization that specifically funds HIV vaccine research. The organization strongly believes that, while ongoing treatment for those infected with HIV and suffering from AIDS is vital, as are prevention campaigns aimed at behavior change, a vaccine is essential to stemming the tide of new infections. While HIV is a pressing international health problem, many pharmaceutical companies remain relatively disinterested in funding HIV vaccine research, and thus most funding comes from private donors, foundations, and national governments rather than shareholders. The IAVI serves as a centralized dis-
International Center for Equal Healthcare Access (ICEHA)
tributing body of funds for HIV vaccine research from a number of nonprofit and governmental organizations, which provide over 90 percent of all funds for HIV vaccine research. The IAVI also engages in public policy advocacy, encouraging governments to make HIV vaccine development and approval a priority, as well as asserting that any future vaccine should be universally available once it is proven effective. Scientists and research organizations funded by IAVI must pledge to make any future vaccine available in developing countries at cost and in sufficient quantities, regardless of home country intellectual property right laws. The IAVI has also promoted the idea of constructing a quasi-market for vaccines by encouraging G8 countries (United Kingdom, Canada, France, Germany, Italy, Japan, Russia, and United States), among others, to guarantee low-cost loans for developing countries heavily burdened by HIV to purchase vaccines when they become available, loans which can be paid back by future savings on healthcare expenditures. The IAVI functions by financially supporting the development of promising vaccines from initial stages to human clinical trials through partnerships with private companies, academic institutions, and government research facilities. The IAVI’s scientific advisory board selects the most promising vaccine candidates and funds swift acceleration of development and clinical testing. In addition to efficacious promise, one particular concern of the organization is promoting the development of vaccines most effective against the subtypes of HIV that are most prevalent in areas of the world where infection rates are the highest, such as in sub-Saharan Africa. Furthermore, the IAVI is not only concerned with providing an effective vaccine, but also one that is easy to store, administer, and manufacture, so it can be disseminated more quickly and easily in areas with less extensive health infrastructure. The organization also seeks to build basic scientific research capacity in Asian and African countries by building laboratories and training staff. Recognizing a legacy of mistrust regarding human clinical trials among many nations, regions, and peoples, IAVI also works closely with community and national leaders in areas where clinical vaccine trials are being conducted in an effort to alleviate harm, misunderstanding, and distrust. The IAVI also works
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to coordinate results of trials from different sites, ensuring that they are scientifically accurate and internationally comparable. As of mid-2006, the IAVI supported over 30 vaccine candidates in small-scale clinical trials worldwide. SEE ALSO: AIDS; AIDS—Living with AIDS. Bibliography. Susan Hunter, Black Death: AIDS in Afri-
ca (Palgrave Macmillan, 2004); International AIDS Vaccine Initiative, www.iavi.org (cited May 2007).
Annie Dude University of Chicago
International Center for Equal Healthcare Access (ICEHA) Founded by Dr. Marie Charles in 2001, the International Center for Equal Healthcare Access (ICEHA) is a nonprofit organization that engages experienced healthcare professionals to rapidly improve the clinical skills of colleagues in resource-poor countries through the use of innovative methods of mentoring. The Center is based in New York City and is governed by boards of directors in both the United States and the United Kingdom. These boards oversee all activities of the organization and provide strategic, programmatic, legal, and financial direction. The directors on the board comprise an international team of highly qualified and world-renowned experts with expertise in the field of HIV care, developing countries, program design, and legal and financial management. The ICEHA currently focuses on HIV and infectious diseases, leveraging the wealth of medical expertise in the West for maximum impact on national health systems in developing countries. A consistent, high level of quality of instruction is maintained by requiring volunteers to be trained and certified by ICEHA. After being certified, volunteers are seconded to a clinic in a developing country. In order to effectively increase access to HIV care and prevention, and to improve overall management of infectious diseases, ICEHA provides technical assistance at two levels: medical expertise and operational delivery systems. The ICEHA’s programs are based on
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International Classification of Diseases (ICD)
the integration of three methods: a locally relevant HIV teaching curriculum, which ensures that the material taught is pertinent to the resource level of each particular country; workshops consisting of formal training sessions using locally relevant teaching curriculum to provide medical expertise to participating physicians and nurses; and on-site coaching using teams of experienced HIV volunteer physicians and nurses to allow the participation of local healthcare providers to translate the theoretical knowledge obtained during the workshop sessions into practical expertise. Focused on the HIV pandemic and infectious diseases, the ICEHA’s volunteer clinical mentors equip local health professionals with the skills they need to provide the best care for their patients, enabling developing countries to fight epidemics from within. The Center’s programs have proven the immense impact that individuals can have in the improvement of access to HIV care and AIDS medication for patients in developing countries. The ICEHA provides a defined, structured opportunity through which each clinical mentor’s contribution can be maximized, thereby creating access to sustainable HIV/AIDS care throughout a country. Beyond the benefits for patients in the developing world, our volunteer clinical mentors have described their field assignment as “the most extraordinary experience of their professional lives.” In addition, by increasing HIV/AIDS knowledge and expertise amongst healthcare providers, the ICEHA helps to set up a system where HIV transmission caused by unsafe medical practices can be eliminated and HIV prevention messages are delivered and reinforced within the healthcare system. This enables healthcare providers to understand that HIV/AIDS can be addressed both in terms of prevention and care. SEE ALSO: AIDS; International AIDS Vaccine Initiative
(IAVI); Preventive Care.
Bibliography. International Center for Equal Healthcare
Access (ICEHA), www.iceha.org/uniquw (cited 2006); The National Centre for HIV/AIDS Dermatology and STDs (NCHADS), http://www.nchads.org/#Top (cited October 2006); United Nations Development Programme, www. undp.org (cited 2006).
Ben Wynne, Ph.D Gainesville State College
International Classification of Diseases (ICD) The International Classification of Diseases (ICD) is the standard diagnostic international classification system for mortality and morbidity data. The ICD is a structured classification system of disease and associated codes that has been designed to promote international compatibility in health data collecting and reporting. During the 1800s, several statisticians started to develop medical-based data reporting systems. The importance of creating a uniform system was realized and several medical statisticians commissioned the completion of this task. The International Statistical Institute adopted the first edition of the ICD in 1893. The first ICD edition was based on the Bertillon Classification of Causes of Death, developed by Jacques Bertillon (the chief of Statistical Services for the City of Paris). In 1898, the American Public Health Association recommended that several countries use this system and revisions be completed once every 10 years. The ICD is an extremely valuable system, allowing for international and national uniform data analysis for tasks such as disease surveillance and mortality analyses. The Design The ICD contains a description of all known diseases and injuries. Each disease is detailed with diagnostic characteristics and given a unique identifier that is used to code mortality data on death certificates and morbidity data from patient and clinical records. The core of the ICD uses one single list of three alphanumeric character codes starting from A00 to Z99. The first letter of the code designates a different chapter; there are 21 in total. Within each chapter, the three character codes are divided so that they specify different classification axes. The ICD has undergone many revisions as the needs of countries change. Current Use Every country subscribing to the ICD system uses it in varying degrees. Most countries subscribe to the entirety of the ICD system, while some countries use the ICD in hospitals only, some for morbidity only, and other countries have chosen to implement partial code use. The U.S. Department of Health and Human Services felt that the ICD needed to provide better clini-
International Clinical Epidemiology Network (INCLEN)
cal information and developed a system that is referred to as ICD 9th revision: Clinical Modification (ICD-9CM). These CM codes are much more precise and allows for stronger analyses. The ICD-9-CM is used by hospitals and other healthcare facilities. The ICD-10, developed in 1992, is the most current version and was adopted for use in 1999. The ICD-10 is currently used to report mortality data, while the ICD-9-CM is still used for reporting morbidity. The World Health Organization and International Statistics The World Health Organization (WHO) assumed the responsibility of publishing the ICD in 1948 and currently collects all ICD international data for all general epidemiological surveillance and health management purposes. WHO reports international health statistics for those countries that use the ICD system. The ICD is a core classification of the WHO Family of International Classifications (WHO-FIC). SEE ALSO: Department of Health and Human Services
(DHHS); International Epidemiological Association (IEA); World Health Organization (WHO). Bibliography. National Center for Health Statistics,
“Classifications of Disease and Functioning & Disability,” http://www.cdc.gov/nchs/default.htm (cited July 2007); World Health Organization, “History of the Development of the ICD,” http://www.who.int/classifications/icd/en/ HistoryOfICD.pdf (cited July 2007). Sudha R. Raminani, M.S. The Fenway Institute
International Clinical Epidemiology Network (INCLEN) Created in 1980 as a project of the Rockefeller Foundation, the International Clinical Epidemiology Network (INCLEN) has been an independent nonprofit organization since 1988. The organization is a unique global network of clinical epidemiologists, biostatisticians, health social scientists, health economists,
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and other health professionals dedicated to improving the health of disadvantaged populations, particularly those in poorer nations, by promoting equitable healthcare based on the best evidence of effectiveness and the efficient use of resources. To accomplish its goals, INCLEN uses the network to conduct collaborative, interdisciplinary research on high-priority health problems, and to train future generations of leaders in health-care research. INCLEN’s membership includes medical institutions in more than two dozen countries throughout the world. The multi-disciplinary faculty at member institutions includes clinical epidemiologists, health social scientists, biostatisticians, and clinical economists, each of whom believes that fighting disease in an age of limited financial resources depends on integrating the principles of clinical epidemiology into his or her practice. INCLEN provides a forum for researchers to discuss critical health issues through educational programs, global meetings, and an international communications network. It supports young researchers and provides network members opportunities to participate in collaborative clinical studies. As a partnership of clinicians and health scientists who are trained to use and produce the best possible evidence in their medical decision making, INCLEN has had a profound impact on healthcare practices globally. The Networks partners include the Child Health Research Project (CHR), COHRED—Collaboration with International Health Research Programmes, the Global Forum for Health Research, The Alliance for Health Policy and Systems Research, Training Programs in Epidemiology and Public Health Interventions Network, and the International Epidemiological Association. Usually held in a different locale annually, INCLEN’s Global Meeting is preceded by collaborative research planning meetings and includes continuing education workshops on such topics as Medical Ethics in Research, Pharmacoepidemiology, Reproductive Health, and Environmental Health Issues. The meeting attracts some 400 attendees annually and is an excellent forum for intellectual exchange and information dissemination. Regional Meetings are held in Latin America, India, China, Africa, and southeast Asia to allow researchers to meet and discuss health issues and present scientific papers. All INCLEN meetings are combined with an ongoing program in continuing education. Faculty members are selected from medical institutions in North America,
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International Committee of the Red Cross (ICRC)
Australia, Europe, Africa, Asia, and Latin America. Various educational workshops are held throughout the year by INCLEN faculty at various host member institutions. Published semiannually, the INCLEN newsletter highlights research interests and accomplishments of INCLEN members around the globe, including local, regional, and international collaborative research projects on a wide range of topics. The newsletter also relates news of the network, such as strategic planning at local, regional and global levels; meeting schedules, and funding possibilities. SEE ALSO: Epidemiologist; Epidemiology. Bibliography. Alliance for Health Policy and Systems
Research, www.alliance-hpsr.org/jahia/Jahia (cited October 2006); International Clinical Epidemiology Network (INCLEN), www.inclen.org (cited October 2006); David E. Lilienfeld and Paul D. Stolley, Foundations of Epidemiology (New York: Oxford University Press; 1994); The International Epidemiological Association (IEA), www.dundee. ac.uk/iea (cited October 2006). Ben Wynne, Ph.D Gainesville State College
International Committee of the Red Cross (ICRC) With origins dating back to the 1860s, the International Committee of the Red Cross (ICRC) is an impartial, neutral, and independent organization whose exclusively humanitarian mission is to protect the lives and dignity of victims of war and internal violence and to provide them with assistance in times of need. It directs and coordinates international relief activities wherever there is major conflict and endeavors to prevent suffering by promoting and strengthening humanitarian law and universal humanitarian principles. The Committee’s chief tasks revolve around monitoring the compliance of warring nations with regard to the Geneva Convention, organizing care for soldiers wounded on the battlefield, supervising the treatment of prisoners of war, helping with the search for missing person’s during time of war, organizing the protec-
tion and care of civilian populations, and arbitration between warring parties during an armed conflict. In February 1863 in Geneva, Switzerland, the Geneva Public Welfare Society set up a committee of five Swiss citizens to look into the ideas offered by Henri Dunant in his book Un Souvenir de Solferino which dealt with the protection of sick and wounded soldiers during combat. The committee had as its members Guillaume Henri Dufour (1787–1875), a general of the Swiss army and a military writer who became the committee’s president for its first year and its honorary president thereafter; Gustave Moynier (1826–1910), a lawyer and president of the sponsoring Public Welfare Society who devoted the rest of his life to Red Cross work; Louis Appia (1818–98) and Theodore Maunoir (1806–69), both well-respected medical doctors; and Henri Dunant (1828–1910) himself. The committee called an international conference that met later in the year which, with 16 nations represented, adopted various resolutions and principles, along with an international emblem, and appealed to all nations to form voluntary units to help the wartime sick and wounded. These units eventually became the National Red Cross Societies, and the Committee of Five eventually became the International Committee of the Red Cross. In 1864, an international diplomatic meeting was held at Geneva at the invitation of the Swiss government. The assembly formulated the Geneva Convention of 1864. This international “Convention for the Amelioration of the Condition of the Wounded and Sick in Armed Forces in the Field” advanced resolutions guaranteeing neutrality for medical personnel and equipment and officially adopting the red cross on a white field as the identifying emblem. A pact was signed on August 22, 1864, by 12 states, and was later accepted by the others. As a result, the work of the Red Cross began. Three other conventions were later added to the first, extending protection to victims of naval warfare, to prisoners of war, and to civilians. Although the Red Cross has always given major service during time of war, it has had an even greater long-term impact through its gradual development and operation of humanitarian programs that serve continuously in both peace and war. The organization of the ICRC is composed of several elements. The self-governing National Red Cross Soci-
International Council of AIDS Service Organizations (ICASO)
eties, including the Red Crescent in Muslim countries and the Red Lion and Sun in Iran, operate on the national level through their volunteer members and also participate in international work. The League of Red Cross Societies is a coordinating world federation that facilitates contact between the individual societies, acts as a clearinghouse for information, assists the societies in setting up new programs and in improving or expanding those already existing, and coordinates international disaster operations. It functions under an executive committee and a board of governors on which every national society has representation. In the modern era, the ICRC itself is private, independent group of Swiss citizens that functions during war or conflict whenever intervention by a neutral body is necessary. As guardian of the Geneva Conventions and of Red Cross principles, it promotes their acceptance by governments, suggests their revision, works for further development of international humanitarian law, and recognizes new Red Cross Societies. The International Red Cross Conference, which met for the first time in 1867, is the organization’s highest legislative body. It is composed of representatives of the National Societies, the International Committee, and those governments that have signed the Geneva Conventions. It meets every four to six years and reviews Red Cross policy and activities, suggests ways that the organization might improve itself, and discusses the adoption of new initiatives. SEE ALSO: International Federation of Red Cross and Red
Crescent Societies; International Red Cross and Red Crescent Movement (RCRC). Bibliography. Clyde E. Buckingham, For Humanity’s
Sake: The Story of the Early Development of the League of Red Cross Societies (Public Affairs Press, 1964); Max Huber, Principles and Foundations of the Work of the International Committee of the Red Cross, 1939–1946 (ICRC, 1947); International Committee of the Red Cross, www.icrc.org (cited October 2006); James Avery Joyce, Red Cross International and the Strategy of Peace (Hodder & Stoughton, 1959). Nobelprize.com: International Committee of the Red Cross, nobelprize.org/nobel_prizes/peace/laureates/ 1963/red-cross-history.html (cited October 2006). Ben Wynne, Ph.D Gainesville State College
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International Council of AIDS Service Organizations (ICASO) A Toronto, Canada-based organization, the International Council of AIDS Service Organizations (ICASO) is a global umbrella organizing body for community-based AIDS service organizations and nongovernmental groups. Founded in 1991, it has secretariats based in five different geographic areas (Africa, Asia/Pacific, Europe, Latin American and the Caribbean, and North America), as well as the main Canadian office. In addition to these official five secretariats, the ICASO is also aligned with several national networks of people living with HIV. Individuals cannot join ICASO directly, although some are appointed based on specific reasons such as past contributions and institutional linkages. A board of 10 advisers is elected annually. The Council’s central focus is promoting dignity, care, services, and human rights for people living with HIV and AIDS. It is a strong international advocate for ending discrimination against HIV-positive persons, harm reduction approaches that enable individuals to make their own choices regarding prevention, and providing universal access to antiretroviral therapy. It does so by lobbying national governments and international agencies directly and by encouraging its nation-level affiliates to do so in their own countries. The Council also lobbies national governments to scale up health systems infrastructure to meet the needs of those living with HIV and AIDS. The Council also functions by supporting alreadyexisting community-based service organizations, rather than directly providing services. The Council especially tries to channel funding toward communities that are struggling to provide services due to resource constraints, especially populations that shoulder much of the burden of caring for those infected with HIV. The ICASO plays an important role in the governance of the Global Fund, as well as encouraging national governments to implement their commitments under the UNGASS (United Nations General Assembly Special Session) HIV/AIDS resolution. Like the United States-based National Association of People with AIDS, the Council places a high premium on the participation of HIV-positive people in all
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International Epidemiological Association (IEA)
of its programs, as well as training people living with HIV/AIDS to become advocates for HIV prevention, research, treatment, and care in their own countries. The Council also encourages communities, however defined, to articulate their own HIV/AIDS prevention and treatment needs, and encourages national governments and international agencies to respect these priorities and values. Recent research initiatives have focused on how communities have been involved in vaccine development, how nations have implemented wide-scale anti-retroviral treatment in their countries, and how community-based groups have increased health literacy in response to HIV/AIDS. As does the International AIDS Vaccine Initiative, the ICASO strongly believes that the HIV pandemic will be stopped quickest by discovering and disseminating an effective HIV vaccine. Like the International Women’s Health Coalition, the ICASO strongly promotes the development of female-based HIV prevention methods, such as vaginal microbicides. The Council receives funding from, among others, the Ford Foundation, the Gates Foundation, the Danish and Canadian governments, UNAIDS, the International AIDS Vaccine Initiative, and several pharmaceutical companies. SEE ALSO: AIDS; International AIDS Vaccine Initiative
(IAVI).
Bibliography. Michael Pollak, The Second Plague of
Europe: AIDS Prevention and Sexual Transmission among Men in Western Europe (Haworth Press, 1994); U.S. Department of Health and Human Services, “AIDS info,” www.aidsinfo.nih.gov (cited February 2007).
Annie Dude University of Chicago
International Epidemiological Association (IEA) Originally founded in 1954 as the International Corresponding Club, the International Epidemiological Association (IEA) seeks to facilitate communication among those engaged in research and teaching in epidemiology throughout the world, and to engage in the development and use of epidemiological methods in
all fields of health including social, community and preventive medicine and health services administration. These aims are accomplished by holding scientific meetings and seminars, by the publication of journals, reports, monographs, transactions or books, by contact among members, and by other activities consistent with these aims. The founders of the Association were John Pemberton of Great Britain and Harold N. Willard of the United States. Recognizing the importance of the dissemination of current information to healthcare professionals, these men sought to establish an organization “to facilitate the communication between physicians working for the most part in university departments of preventive and social medicine, or in research institutes devoted to these aspects of medicine, throughout the world.” This goal was initially achieved by the publication of a bulletin twice a year and by members endeavoring to “ensure a friendly and hospitable welcome for visitors” from other countries. The first issue of the bulletin appeared in January 1955 and contained contributions from 26 correspondents from nine countries. Today, the Association includes more than 1,500 members from over 100 nations. Every three years, the IEA holds a global scientific meeting at different locations throughout the world, and regional meetings at regular intervals. The Association is governed by a council elected from the IEA’s active members and consisting of the president, president-elect, secretary and treasurer, and from seven to 10 other members. Published six times a year, the International Journal of Epidemiology is the official, peer-reviewed journal of the Association and an essential requirement for anyone who needs to keep up to date with epidemiological advances and new developments throughout the world. The Journal encourages communication among those engaged in the research, teaching, and application of epidemiology of both communicable and noncommunicable disease, including research into health services and medical care. Also covered in its pages are new methods, epidemiological and statistical, for the analysis of data used by those who practise social and preventive medicine. As a result of opportunities that the IEA has afforded epidemiologists to meet with colleagues from other countries, several international collaborative studies have been undertaken by Association members. The results of
International Federation of Red Cross and Red Crescent Societies (IFRC)
many of these have been published in the Journal. To promote epidemiology as a discipline the IEA works in cooperation with the International Clinical Epidemiology Network (INCLEN), the Field Epidemiology Training Program (FETP) of the United States Centers of Disease Control and Prevention (CDC) and other organizations with similar missions. SEE ALSO: Epidemiology; International Clinical Epidemi-
ology Network (INCLEN).
Bibliography. European Epidemiology Federation, www.
dundee.ac.uk/iea/euro_Contents.htm (cited October 2006); International Clinical Epidemiology Network (INCLEN), www.inclen.org (cited October 2006); International Epidemiological Association (IEA), www.dundee.ac.uk/iea (cited 2006); International Society for Environmental Epidemiology, www.iseepi.org (cited October 2006), World Health Organization, www.dundee.ac.uk/iea/euro_Contents.htm (cited October 2006). Ben Wynne, Ph.D Gainesville State College
International Federation of Red Cross and Red Crescent Societies (IFRC) Formed in 1919, the International Federation of Red Cross and Red Crescent Societies (IFRC) exist, to improve the lives of the world’s most vulnerable people through the mobilizing of human efforts. Serving as the umbrella organization of 185 Red Cross and Red Crescent societies, this humanitarian society pledges to provide assistance to all, regardless of nationality, race, religious beliefs, class, or political opinions. The Red Crescent replaces the symbol of the Red Cross in Islamic countries. The IFRC oversees relief operations in four main areas: promoting humanitarian values, disaster response, disaster preparedness, and health and community care. Promoting humanitarian values involves respecting and working with others to solve problems. Disaster response requires the majority of IFRC time and attention, as they provide assistance to approxi-
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mately 30 million people, worldwide, each year. IFRC responds to natural disasters as well as man-made ones such as war and accompanying refugee problems. Although much of their disaster response work involves emergency situations, the IFRC also works on longterm rehab projects. One longer-term project is the relief efforts following an Iranian earthquake on December 26, 2003, shattered the city of Bam, killing 26,000 people, injuring 30,000 and leaving 75,000 homeless. Eighty-five percent or more of the city’s buildings were destroyed, including 131 schools and 119 healthcare facilities. On the third year anniversary of the earthquake, nine schools, two health clinics, an orthopedic center, and a road rescue center, all funded by the IFRC, were dedicated. Because of the increase in significant natural disasters, the IFRC has increased the funding spent on disaster preparedness, educating people about risks and distributing information about how to respond in a disaster. In health and community care, the IFRC assists communities in providing basic health services and education. The IFRC relies upon volunteer efforts and so the organization spends some resources on volunteer training. The IFRC Secretariat is located in Geneva, Switzerland. His/her role is to coordinate international disaster relief and elicit cooperation between and among national societies; IFRC societies exist in more than 150 countries. The IFRC also provides training for its societies, including first aid training. It partners with other agencies with compatible goals, from a local level to a global one. In May 2006, the IFRC published an overview of its first 88 years of service. Out of 2,216 appeals for help, the majority (728) have been from Africa, with 577 coming from Asia and the Pacific region. Overall, 569 of the appeals have been for disaster relief because of floods, storms, and cyclones, with 438 appeals being requests for socioeconomic relief. The largest donors are Sweden, United Kingdom, European Commission’s Humanitarian Aid Office, Norway, Japan, the United States, the Netherlands, Finland, Ireland, Canada, Germany, Switzerland, France, the United Nations High Commissioner for Refugees and Denmark, in that order. From 1997 to 2006, the IFRC has been able to fulfill anywhere from 44 percent to 85 percent of its requests for funding and assistance.
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International Genetic Epidemiology Society (IGES)
SEE ALSO: American Red Cross (ARC); International Com-
mittee of the Red Cross (ICRC); International Red Cross and Red Crescent Movement (RCRC).
Bibliography. International Federation of Red Cross and
Red Crescent Societies, http://www.ifrc.org (cited June 2007).
Kelly Boyer Sagert Independent Scholar
International Genetic Epidemiology Society (IGES) The International Genetic Epidemiology Society (IGES) studies the basis for disease, giving significant weight to both genetic factors and the influence of the environment on genetic predispositions toward disease. Society members believe the recently successful mapping of the human genome—the complete set of human genes—will propel research forward in a way that blends together theories of disease as nature (genetics) and disease as nurture (environment) into a cohesive and useful whole. Members of IGES come from a wide variety of scientific disciplines, ranging from geneticists and biologists to statisticians and mathematicians. The unifying factor is the belief that disease is a complex interaction of predisposed risk factors and inherited conditions that respond in a particular way to environmental triggers and in varying environmental contexts. Committees include the ELSI committee, and the education, membership, scientific program, and publication committees. ELSI stands for ethical, legal, and social issues; this committee was formed by the National Institutes of Health (NIH) and the United States Department of Energy (DOE) when participating in an international human genome mapping project. Ethical concerns considered by IGES include the fairness of use of information; who, the researchers must ask, could have access to this private information and how would it be used? Privacy and confidentiality concerns must be addressed and the ownership of genetic information gathered during research must be fairly determined. Researchers must also consider the psychological impact and stigmatization felt by
individuals or minority groups whose genetic pattern differs from the norm. Other ethical issues include reproductive-related questions, such as those surrounding fetal genetic testing; clinical evaluation methods and their accuracy; uncertainties, such as whether minors should be tested for adult-onset diseases; conceptual and philosophical questions regarding genetic determination versus a person’s free will; health and environmental issues, especially with genetically modified foods; and commercialization of genetic material, and the accompanying copyright, trade secrets, and patent issues. IGES publishes Genetic Epidemiology, a peer-reviewed journal containing articles sharing research results that analyze the relative weight of genetic and environmental factors in human disease. Specific topics recommended for articles include a review of the natural selection process, dubbed the ultimate gene by environment interaction by the journal’s editor; and large-scale genetic research projects. IGES hosts annual scientific meetings featuring lecturers from around the world—often in conjunction with other associations such as the American Society of Human Genetics, the International Congress of Human Genetics, and the Society for Epidemiological Research (SER)—who present the results of their research. The society annually presents two $1,000 awards—the James V. Neel and Roger Williams awards—for the best presentations by a student and by a young scientist, respectively. It also provides continuing education in genetic epidemiology methods and subsidizes travel expenses for students in need. IGES’s ������������������������ Web site (http:// iges.biostat.wustl.edu/index.htm) is used to post announcements of general interest to those in the field, job openings, and, somewhat surprisingly, humorous audios of songs satirizing genome studies. SEE ALSO: Gene Mapping; Genetics; Genome; Human Ge-
nome Organisation (HUGO); National Human Genome Research Institute (NHGRI). Bibliography. International Genetic Epidemiology So-
ciety (IGES), http://iges.biostat.wustl.edu/iges.html (cited June 2007); International Society for Environmental Epidemiology, www.iseepi.org (cited June 2007). Kelly Boyer Sagert Independent Scholar
International Red Cross and Red Crescent Movement (RCRC)
International Health Ministries Office (IHMO) The International Health Ministries Office (IHMO) is a mission-based agency of the Presbyterian Church in the United States (PC USA) that focuses on worldwide health concerns of vulnerable populations. IMHO partners with churches and other collaborative agencies around the world to attempt to prevent, alleviate and treat health concerns in the most impoverished parts of the globe. IMHO serves health needs in over 30 countries, with prevention and treatment for malaria and HIV/AIDS in African nations currently serving as prime foci. IMHO has chosen “Building Healthy Communities” as a theme for its mission-based activities. Their strategic plan states a holistic health vision and an evolving focus that will place an increasing emphasis on programs that assist global associate churches as they formulate programs to prevent disease. These programs should be community based and should meet local and regional health needs. Some of the programs include immunization clinics in rural locations, HIV/AIDS education, dietary education, and projects that ensure clean drinking water. Besides providing support and resources to partner churches around the globe, the IMHO guides individual PC USA congregations and presbyteries (regional bodies of Presbyterian churches) in the United States as they develop and participate in overseas health missions. One significant program initiated by IHMO and led by Presbyterian women’s groups is The NetWorkers Malaria Prevention Program. This program was developed because of the devastating loss of health, life, and productivity from malaria in African countries; the disease causes more than 1 million deaths in Africa annually. NetWorkers promote the use of insecticide-treated mosquito nets that greatly reduce opportunities for malaria transmission. NetWorkers help purchase nets, insecticide, and educational materials and they also sew nets from kits. IMHO developed a 10-minute video, the “NetWorkers Safe Motherhood Projects,” that shares information about how Presbyterian women in the United States partner with women in Africa to diminish the loss of life and productivity because of malaria. On a broader scale, IMHO developed a plan wherein
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churches and other philanthropic agencies can effectively work together to combat malaria. The Presbyterian AIDS Network (PAN) is an international program that responds to the AIDS health crisis in countries hardest hit by the disease, most notable Cameroon, the Democratic Republic of Congo, Ethiopia, and Malawi. Members of PAN share information about the devastating effects of HIV/AIDS in Africa to Presbyterian congregations in the United States and they also raise funds to combat the disease. Educational components of the PAN program include teaching African women about mother-to-child transmission of HIV/AIDS and encouraging women to be tested for the disease; 90 percent of the children with AIDS in Africa contracted the disease from their mothers. PAN also teaches the A-B-C approach to AIDS prevention: abstinence for youth; be faithful for those with regular sexual partners; and condoms as a way to reduce contact with the AIDS virus for nonabstainers without a regular sexual partner. SEE ALSO: AIDS; AIDS and Infections; AIDS and Preg-
nancy; Malaria.
Bibliography. International Health Ministries Office,
www.pcusa.org/health/international/ (cited June 2007); 2005 Fiscal Report of Presbyterian Women/IHMO, www. interchurch.org/resources/uploads/files/77Presbyterian Women.MedicineBoxReport.2005.doc (cited June 2007). Kelly Boyer Sagert Independent Scholar
International Red Cross and Red Crescent Movement (RCRC) The International Red Cross and Red Crescent Movement (RCRC) is the umbrella association of two distinct but interconnected entities: the International Committee of the Red Cross (ICRC) and the International Federation of Red Cross and Red Crescent Societies (IFRC). The RCRC also oversees all of the national Red Cross and Red Crescent societies, located in 186 countries around the globe, as well as the 97
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International Red Cross and Red Crescent Movement (RCRC)
million people volunteering in service to the movement. The ICRC and the IFRC have central offices located in Geneva, Switzerland, while the national societies are located within the countries they represent. The movement was started by a Swiss businessman named Henry Dunant, who was attempting to meet with Napoleon in 1859 over commerce-related concerns. Heading to Solferino in Italy to meet with him, Dunant found the city to be the site of an intense battle between the French armies and the Austrian armies, with the source of the dispute being the status of Italy’s independence. More than 40,000 soldiers were wounded or killed during that battle, and Dunant was stunned at the lack of medical care given to the men and he was shocked by their unrelieved suffering. Dunant did not pursue his business meeting with Napoleon, instead focusing on finding relief for the wounded soldiers. Afterward, he wrote a book, A Memory of Solferino, publishing it with his own money and sending it to military and political leaders throughout Europe. He wanted to publicize his concerns over the suffering of soldiers and advocate for the creation of an international, volunteer-based relief society. By 1863, his efforts began bearing fruit, with the formation of the International Committee for Relief to the Wounded that had initial support from these countries: Baden, Bavaria, France, Britain, Hanover, Hesse, Italy, the Netherlands, Austria, Prussia, Russia, Saxony, Sweden, and Spain. This was one of the earliest organized attempts to establish methods for treating the wounded on the battlefield and to relieve suffering from combat; the name of this committee was later changed to the International Committee of the Red Cross (ICRC). In modern times, the ICRC brings aid to victims of war and armed conflict worldwide. The committee directs activities at the sites of international conflict to provide relief, and it works to promote humanitarian principles to prevent future suffering. The International Federation of the Red Cross (IFRC) was founded in 1919 and it oversees the national societies that carry out humanitarian aid to victims of disasters, whether man-made or natural, such as hurricanes and earthquakes. The IFRC also gives aid to refugees and people in the throes of health emergencies. The IFRC promotes cooperation among its national societies and it works to strengthen their abilities to prepare for disasters and their relief. Mem-
ber societies also provide health-related programs in their own countries and, during war time, the societies support the military’s medical units. This movement is based on seven principles: humanity, impartiality, neutrality, independence, voluntary service, unity, and universality. To fulfill the principle of humanity, people associated with the movement are committed to protected human health and life, and to promote respect, cooperation, and peace. Impartiality means no discrimination based on race, religious beliefs, political ideologies, nationality, or any other such category. To maintain neutrality, members of this movement do not participate in divisive debates, whether political, religious, or of any other ideological nature. The movement in each country, although often closely connected to other humanitarian efforts of government agencies, vows to stay independent of political dealings. The movement is voluntary in that participants cannot personally gain from their efforts and all must remain unified, with no more than one society in any country. Finally, each part of the overall movement is equal to every other part, and no one country or society can take precedence over another, except when deemed an initiative leader. Taken all together, these organizations form the International Red Cross and Red Crescent Movement (RCRC). The Standing Commission of the Red Cross and Red Crescent meets every four years, to determine the strategic direction of the movement, to coordinate efforts, and to assist in the implementation of the Red Cross and Red Crescent resolutions. The Standing Committee does make recommendations for or oversee operational matters. The symbol of the RCRC, a red cross on a white background, is in fact the Swiss flag in reverse; for countries wherein the Islamic religion is predominant, a red crescent replaces the cross in the flag. The RCRC movement publishes a quarterly magazine, Red Cross, Red Crescent, that shares humanitarian efforts of societies around the world. There is an International Red Cross and Red Crescent Movement Museum located in Geneva, Switzerland, with photos and documents from the past, and information about efforts taking place in the present. Historical figures honored in the museum include founder Henri Dunant; British nurse, Florence Nightingale, and Russian surgeon, Nikolai Pirogov, both of whom nursed the wounded from the Crimean War; and
International Society for Environmental Epidemiology (ISEE)
the American nurse, Clara Barton, who nursed the wounded during the U.S. Civil War. Current initiatives include the introduction of a third icon, the Red Crystal, as a symbol of unity; efforts are now being made to infuse this symbol with the same level of respect now given to the Red Cross and the Red Crescent. Furthermore, the Red Crystal does not have the controversial and potentially divisive connotations of a cross or crescent. Changes in statutes have allowed Israel to join the movement. Other initiatives include a renewed commitment to the protection of women and children during wars. SEE ALSO: International Committee of the Red Cross
(ICRC); International Federation of Red Cross and Red Crescent Societies (IFRC). BIBLIOGRAPHY. International Committee of the Red Cross
(ICRC); http://geneva.usmission.gov/rcrc/RCRCMovement.pdf (cited June 2007); International Red Cross and Red Crescent Movement web site, http://www.redcross. int/en/default.asp (cited June 2007). Kelly Boyer Sagert Independent Scholar
International Society for Environmental Epidemiology (ISEE) The International Society for Environmental Epidemiology (ISEE), founded in 1987, initially provided a U.S.based forum for epidemiological experts to discuss three topics: clean drinking water technology, air pollution concerns, and the increased risk of cancer in and around nuclear facilities. Since then, ISEE has expanded to an international organization that addresses environmental hazards and adverse health effects connected to exposure to those hazards, the interaction of genetics and environmental influences in causing these health conditions, and ethical questions surrounding these topics. Membership is open to environmental epidemiologists and other scientists worldwide, and there are now more than 800 members residing in 60 countries. Although approximately 50 percent of members reside in
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North America, ISEE is committed to continuing the international scope of its society; there are currently ISEE chapters located in Latin America, the Caribbean, the Mediterranean, central and eastern Europe, the Caucasus, south Asia, east Asia, and North America. To further its goal of international participation, ISEE has held annual conferences in the United States, Canada, Mexico, Europe, the Middle East, Asia, Australia, and Africa. The 2007 annual conference, held in Mexico, focused on the theme of “Translating Environmental Epidemiology into Action: Interventions for a Healthy Future.” From the early stages of development, ISEE has fostered an active collaboration with the International Society of Exposure Analysis (ISEA), a society formed in 1989 to further scientific exploration of environmental contaminants and how exposure to them affects humans and their environment. Members of ISEA come from a variety of scientific disciplines and they lobby to have exposure assessment techniques considered while establishing environmental policies. Collectively, ISEE and ISEA work together toward common goals. Members of ISEE are encouraged to participate in the organization’s committees. These include the Nominations Committee, Annual Conference Committee, and Awards Committee, which deal with the ongoing business of ISEE. The Membership Committee and Communications Committee are charged with providing educational and outreach materials to members and prospective members. The Ethics and Philosophy Committee created one of the first epidemiological codes of ethics, one that addresses obligations to subjects of research, to society, to sponsors, and to colleagues. An ethics-based ISEE award of interest is the ISEE Research Integrity Award, granted to researchers who have withstood significant pressure from special interest groups and continued to act with exceptional integrity to protect public health. Related to this is the ISEE Support for Victimized Colleagues that focuses on the pressures and threats perceived by researchers who identify hazards that adversely affect special interest groups. In these instances, ISEE may write a letter of support and/or otherwise engage ISEE in supporting these researchers, whether they are members of ISEE. The Capacity Building in Developing Countries Committee encourages collaborations between developed and developing countries and supports training of scientists and researchers in developing countries. ISEE
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International Society for Pharmacoepidemiology (ISPE)
publishes Epidemiology, a peer-reviewed journal that publishes original research. The journal welcomes scientific articles that challenge current assumptions. SEE ALSO: International Genetic Epidemiology Society
(IGES); Society for Healthcare Epidemiology of America (SHEA).
Bibliography. International Genetic Epidemiology Soci-
ety (IGES), http://iges.biostat.wustl.edu/iges.html; International Society for Environmental Epidemiology, www. iseepi.org/. Kelly Boyer Sagert Independent Scholar
International Society for Pharmacoepidemiology (ISPE) The International Society for Pharmacoepidemiology (ISPE) is a nonprofit organization that provides a global forum for scientific discussions about pharmacoepidemiology, with an ultimate goal of improving public health worldwide. To accomplish that goal, pharmacoepidemiologists study how drugs affect significant numbers of people, using techniques gleaned from pharmacology and epidemiology alike; the field of pharmacoepidemiology has, therefore, been called the bridge between these two scientific disciplines. Pharmacologists study drugs and those who specialize in clinical pharmacology monitor how drugs affect patients so as to determine the risks and benefits of pharmaceuticals. To determine the probabilities of positive benefits or adverse reactions of a particular pharmaceutical, pharmacoepidemiologists use methodologies typically used in epidemiological studies. Conversely, the field of epidemiology focuses on the risk factors of disease and the probabilities of diseases appearing in certain populations. There are two branches of epidemiology: descriptive and analytic. Descriptive epidemiology creates a description of diseases, along with the frequency of occurrences. This discipline does not use control groups and, therefore, does not test hypotheses. Analytic epide-
miologists, however, observe disease and record their observations, but they also conduct clinical trials to test their hypotheses. Pharmacoepidemiologists use these methods to study pharmaceuticals. ISPE has members from 53 countries, with national chapters located in Argentina, Belgium, Denmark, and the Netherlands. Members of ISPE use pharmacoepidemiology studies to develop health-related policies, to educate healthcare professionals about ISPE research results, and to advocate for their field of study and its specialties including the discipline of pharmacovigilance. Researchers conduct ongoing monitoring of adverse affects of pharmaceuticals of already-approved drugs. In practice, this involves healthcare professionals reporting negative reactions to drugs, with pharmacovigilance specialists correlating incoming data to create reports about the level of safety of a particular pharmaceutical, once being used by large numbers of people. This is a much more efficient method of research than basing recommendations on more random reporting of adverse affects. ISPE recommends increasing the number of patients involved in clinical testing of new pharmaceuticals before they are approved for general use. Moreover, they recommend that physicians fully understand potentially adverse effects of the drugs, and that they receive updated information of adverse affects, which may increase after released at large. ISPE officials also advocate for continuing drug safety testing after pharmaceuticals are approved, which necessitates increased funding for the epidemiological studies required. Officials of ISPE see a lack of coordination between the pharmaceutical industry and governmental regulatory agencies as another flaw in the drug monitoring process. To ease newly approved pharmaceuticals into use, ISPE recommends limited pharmaceutical to consumer marketing within the first few years of drug approval, thus limiting the potential of harm done by adverse drug affects not noted during its clinical trial stage. Other ��������������������������������������������� specialized areas of pharmacoepidemiology study include drug utilization research and therapeutic risk management. Subjects of recent ISPE study include the potential connection between beta-blockers and decreased hip and vertebral fractures; antidepressants and suicide potential in pediatric patients; pulmonary hypertension in newborns; antiepileptic drugs and fractures; and late pregnancy use of serotonin reuptake inhibitors.
International Society of Geographical and Epidemiological Ophthalmology (ISGEO)
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gust 19, 2005), www.highbeam.com/doc/1G1-135276040. html (cited June 2007); International Society for Pharmacoepidemiology, http://www.pharmacoepi.org/; “International Society for Pharmacoepidemiology Raises Concerns about Limitations of Pre-Marketing Drug Trials—Calls for Restrictions on Direct-to-Consumer Advertising,” PR Newswire (February 22, 2005), www.highbeam.com/doc/ 1G1-129011578.html (cited June 2007). Kelly Boyer Sagert Independent Scholar
Pharmacoepidemiologists study how drugs affect significant numbers of people.
Members of ISPE may be employed by pharmaceutical companies, government agencies, universities, or private/public nonprofit agencies. Researchers come from a wide variety of scientific disciplines, including epidemiology, biostatistics, medicine, nursing, pharmacology, pharmacy, law, and health economics, while other members have a journalistic background. ISPE holds conferences and workshops, and publishes a quarterly newsletter along with a journal, Pharmacoepidemiology and Drug Safety. Focus of written materials may be on pharmaceuticals still in developmental stages, or a drug’s delivery method, use, cost, and/or effects. Other topics include maintaining pharmaceutical databases; the importance of data confidentiality and the difficulties faced in maintaining privacy; and the increasing need for more quality-of-life studies. To ensure timely dissemination of knowledge, the journal contains a “Fast Track Publication” column that provides peer-reviewed overviews of studies as quickly as 15 weeks of receipt by the journal. SEE ALSO: Epidemiologist; Epidemiology; Pharmacology;
Pharmacopeia/Pharmacopoeia.
Bibliography. “Drug Safety and Risk Management—ISPE
Annual Meeting—Medical Media Alert,” PR Newswire (Au-
International Society of Geographical and Epidemiological Ophthalmology (ISGEO) The International Society of Geographical and Epidemiological Ophthalmology (ISGEO) promotes research of all aspects of ocular disease with a focus on blindness prevention, sight preservation, and visual therapy. Membership is open to all health professionals who have an interest in epidemiological ophthalmology; the group states a nonpolitical, nonracial, and nonreligious viewpoint. ISGEO supports epidemiologic research in less economically developed countries and often focuses on diseases affecting third world countries. ISGEO places a special interest in the public health facets of eye disease and the assessment of potentially viable treatments, and it provides partial funding for relevant research projects. Abiding by World Health Organization (WHO) regulations, ISGEO members introduce and debate internationally significant ophthalmologic research, again often focusing on issues relevant to less developed countries. ISGEO meets every two years to present academic research and members are encouraged to learn about the practices of ophthalmology in these countries and cultures. Meetings have been held in Canada, Israel, Spain, Scotland, Italy, Brazil, the United States, Finland, Tunisia, Kenya, Singapore, Belgium, the Netherlands, and Australia. ISGEO may collaborate with other organizations, such as the International Congress of Ophthalmology or the International Agency for the
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International Women’s Health Coalition (IWHC)
Prevention of Blindness, at these international meetings. Members also meet for regional conferences. Conference topics range from presentations on cataracts and glaucoma to macular degeneration, refractive errors, clinical trials in ophthalmology, environmental studies in eye disease, population-based studies of eye disease, and geographic mapping of eye disease. The 16th ISGEO Congress, held in 2000, focused on trachoma, the leading infectious cause of blindness and a disease that occurs two to four times more frequently in women than men. It frequently occurs in poorer populations in Africa, the Middle East, Asia, and Latin America. Trachoma is caused by Chlamydia trachomatis, and researchers continued to explore this topic, post-Congress, publishing their research results in a double issue of the ISGEO journal. ISGEO publishes Ophthalmic Epidemiology, its official journal. The journal contains editorials, articles, books reviews on the subject of ophthalmic epidemiology, public health, and the prevention of blindness. Researchers from around the world have submitted work to this journal, and the Ophthalmic Epidemiology has published cost–benefit analyses, results of risk factor studies, and the outcomes of therapies and healthcare treatments. SEE ALSO: Blindness; Eye Care; Eye Diseases (General);
Ophthalmology; Ophthalmologist.
Bibliography. International Society of Geographical and
Epidemiological Ophthalmology, www.interchg.ubc.ca/ bceio/isgeo/; Ophthalmic Epidemiology, www.tandf.co.uk/ journals/titles/09286586.asp; Sheila West, “Contribution of Sex-Linked Biology and Gender Roles to Disparities with Trachoma,” Emerging Infectious Diseases, www.highbeam. com/doc/1G1-125228849.html (cited June 2007). Kelly Boyer Sagert Independent Scholar
International Women’s Health Coalition (IWHC) The International Women’s Health Coalition (IWHC) is a New York City-based nongovernmental organization that advocates internationally for women’s sexual
and reproductive health. The Coalition was initially founded in 1984, partly in response to then-President Reagan’s “Mexico City policy” or global “gag rule” that prevented private organizations receiving U. S. government funds for advocating for safe abortion, even if this work was done with non-U.S. funds. Rather than focusing only on population control, the Coalition’s main goal is to ensure and enable female reproductive and sexual autonomy, particularly for the estimated 1.2 billion adolescents aged 10–19 throughout the world. The Coalition is particularly adept at shaping the language of international health and population conferences, such as those conducted in Cairo and Beijing in the 1990s, to reflect promoting women’s rights and autonomy as a key element of development policy. The Coalition works mainly by sending monetary support to local partner organizations in Latin America, Asia, and Africa. The Coalition has had particular success working with local researchers, activists, and citizen groups throughout the developing world in addressing reproductive and sexual health issues that were previously considered taboo, such as reproductive tract infections, abortion, and rape. Going beyond providing services, the Coalition has worked with local organizations to promote changes in customs and laws that favor equality for women in other ways as well, such as reforming divorce, child custody, and property inheritance laws. The organization also has a strong focus on lobbying national governments, international agencies, and international donors in order to direct resource flows toward policies and programs it feels will advance reproductive health and security for women. These programs include comprehensive sexuality education for adolescents and young adults, especially regarding sexually transmitted diseases, violence, unwanted pregnancy, and unsafe abortions. The International Women’s Health Coalition also supports full access to a range of contraceptive services, including safe abortions, and has not shied away from fierce political engagement with the United States government, the Vatican, and other governmental and religious authorities. The organization advocates for full sexual rights, including freedom from sexual coercion, violence, assault, and forced marriage. Although the Coalition initially focused solely on women, recently programs have also incorporated men as partners against sexual violence.
Internist
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Recently, the Coalition has expanded programmatic and policy focus to include promoting sexual equality as a means to help women protect themselves from sexually transmitted diseases, particularly HIV. The Coalition has been a prime supporter of microbicide development, which would allow women to protect themselves against HIV infection using vaginal suppositories that do not require male involvement, as condoms do. Additionally, the Coalition has encouraged programs that recognize and promote sexual responsibility among men, as well as advocating for the rights of women in sexual relationships. The Coalition receives financing from private foundations, United Nations agencies, European governments, and corporations, and donates $1.5 to $2 million to programs worldwide annually. Because the organization advocates for full access to contraception and safe abortions, it currently receives no funding from the U.S. government. SEE ALSO: Women’s Health.
An internist is a medical specialist who focuses his or her medical care on adult medicine.
Bibliography. Lesley Doyal, Women and Health Services
(Open University Press, 1998).
Annie Dude University of Chicago
Internist An internist, or a practitioner of internal medicine, is a medical specialist who focuses his or her medical care on adult medicine. After the completion of medical school, it takes three to seven years of internal medicine residency to be trained in the fields of preventing, diagnosing, and treating diseases that affect adults. An internist can take the option of specializing in different fields of general medicine, or can take more training to subspecialize (often referred to as a fellowship of one to three years) in one of 13 areas, generally organized by organ system. Specialties range from adolescent medicine to geriatric medicine. Other specialties include specific fields of medicine such as pulmonlogy, hematology/oncology, gastroenterology, and cardiology. For medical practitioners in the United States, there are two main organizations accredited to certify
internists within their respective fields: the American Board of Internal Medicine and the American Osteopathic Board of Internal Medicine. Internists are equipped with the education and knowledge to deal with whatever problem a particular patient suffers from, no matter how common or rare, or how simple or complex. They are specifically trained to solve complicated diagnostic issues and can deal with severe chronic illnesses and situations where several different illnesses may present at the same time. Internists also are trained to help their patients help themselves by maintaining health and wellness. Internists to ensure the best healthcare for their patients follow issues such as disease prevention and the promotion of health, women’s health, substance abuse, mental health, as well as regular maintenance treatment of common problems for the eyes, ears, skin, nervous system, and reproductive organs. In the principles of diagnosis, the essential tools of any physician are the medical history and the physical examination (this is especially true for the internist.) Descriptions of certain diseases or physical signs and symptoms are important in guiding the internist to a
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Intestinal Parasites
diagnostic conclusion. Included in the medical history is a review of systems, which helps to identify conditions experienced by the patient that might not have been mentioned previously but might help to diagnose. Next, the internist will conduct a physical examination, which includes focused exams to a pertaining problem mentioned by the patient as well as a complete checkup. At this point, the internist is most likely able to create a differential diagnosis list, a variety of possible diagnoses that fit the mesh of signs and symptoms. However, this list is often highly specific and exhausting, therefore the internist might narrow down the list by ordering various blood tests, cultures, and medical imaging tests. Often, these tests also serve as screening tests, especially in older patients, to help maintain health maintenance. After this process has been completed, the internist has arrived at a specific diagnosis and is ready to initiate a treatment plan. Most often these treatments include medications; however sometimes they require a more extensive plan, which is addressed and handled at that time. In today’s busy medical environment, most internists will take the time and pride in caring for their patients for life through continuity of care. Whether it is in the office or the clinics, during hospitalizations or intensive care, in nursing homes or assisted living facilities, internists will usually follow through and keep their patients as top priority. SEE ALSO: Internal Medicine. Bibliography. Thomas M. Habermann, Mayo Clinic In-
ternal Medicine Review, 7th ed. (Informa Healthcare, 2006); Stephen L. Hauser, Dan L. Longo, and J. Larry Jameson, Harrison’s Principles of Internal Medicine 15th ed., Eugene Braunwald, Anthony S. Fauci, and Dennis L. Kasper, eds., (McGraw-Hill Professional Publishing, 2001). Angela Garner University of Missouri
Intestinal Parasites Intestinal parasites are one of the most prevalent, yet overlooked, global health problems. Well over onethird of the population of the world are infected with
an intestinal parasite. Many of these 2 billion people are actually infected with more than one type of parasite. Intestinal parasites affect the health of individuals and of populations by contributing significantly to malnutrition, anemia, and other specific disease syndromes. Intestinal parasites can be divided into two broad groups: single-celled protozoan parasites and complex multicellular worms or helminths. The eggs or cysts of both of these groups are found very commonly in the environment or are associated with animals or foods. While they are found in many different environments, contexts, and across socioeconomic levels, they cause the greatest burden of illness in the developing world where hygiene practices, sanitary infrastructure, nutrition, medical care, and appropriate food preparation may be lacking. Only the most common species and diseases will be discussed here. Worms (Helminths) Intestinal worms range in size from only a few millimeters to several meters in length. The most important clinical and epidemiological differences between the species are related to the nature of their reproductive lifecycle and the way they interact or affect their human hosts. There are three types of helminthes: roundworms (nematodes), tapeworms (cestodes), and flukes (trematodes). Adult roundworms and tapeworms are found in the intestines, whereas adult flukes often live in other tissues such as the liver, blood vessels, or lungs depending on the species. The life cycles, diseases, and treatments associated with trematodes are somewhat more complex than for other helminths and will not be discussed here. Most intestinal worms (with a few important exceptions) cannot complete their life cycle inside a human host—that is, they cannot multiply and reproduce without exiting the human body and developing further in the soil or another host organism. For this reason, intestinal worms rarely rapidly overwhelm or kill their human hosts. Intestinal parasites are most often transmitted by the fecal-oral route; persons accidentally orally ingest worm eggs present in soil that has been contaminated by human or other feces. The life cycle of many species involves ingestion as a cyst or egg that hatches in the host stomach or intestines. The larvae then migrate through the body, to the lungs, and back to the intestines. The diseases these parasites cause are usually related to their migra-
Intestinal Parasites
tion through the lungs, or more often via their effects on the intestines, including preventing absorption of nutrients and obstruction. Most helminths only cause serious disease when they are present in large numbers. These effects may include anemia, retardation of growth and development, malnutrition, decreased work capacity, or increased susceptibility to other diseases. Because they are transmitted by contaminated soil or foods, they are usually more common in children who may be less careful with hygienic practices, may eat or play in contaminated dirt, or be more susceptible to the effects of helminth infections. Specific types of nematode intestinal worms include the following: • Ascaris roundworm—the largest worm, which may obstruct the bowels • Hookworm—a small worm that enters the body through the skin, attaches to the intestinal wall, and lives off of blood, causing anemia • Pinworm—a small worm common in North America and the rest of the world. It causes an itchy anus and is primarily found in children • Whipworm—has a whip-like tail and can rarely cause rectal prolapse (rectum falls out through the anus) • Trichinella—a relatively common worm in North America acquired by eating undercooked pig or game meat. Worm larvae spread throughout the muscles of the body and cause inflammation and illness which is usually treated with steroids Beef, pork, and fish tapeworms (cestodes) have a very different life cycle than nematodes. Cestodes are usually ingested in cyst form from infected undercooked animals such as beef, pork, and fish. The cysts develop into long worms composed of many reproductive units and a head, which anchors in the intestine. The worms then produce thousands of eggs, which are passed into the stool. Symptoms of tapeworm infections are usually nonspecific and are rarely severe. They include weight loss, malnutrition, nausea, itching, or allergic symptoms. Ingestion of pork tapeworm eggs can result in cysts, rather than adults, in the human tissue causing an entirely different and more dangerous clinical syndrome. There are several treatments available for intestinal worms. Some medications kill the worms, while
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others paralyze the worm allowing the body to expel it. Anti-helminth medications must often be taken over two cycles separated by a week to ensure that all worms are killed or expelled. Intestinal worms are so common among children in many parts of the world that deworming is often done in schools at regular intervals. Intestinal Protozoa Protozoa are single-celled eukaryotic (contain a true nucleus) parasites that may infect various human tissues and organs. Malaria, for example, is a protozoal infection of the blood and liver. Intestinal protozoa, as with helminths, are most common in areas with inadequate sanitation and food hygiene, but can be found almost anywhere in the world. There are many different species of protozoa which are often grouped according to their means of locomotion: ciliates—those with small hair-like appendages; flagellates—those with single or multiple whip-like tails; amoeboids— which move using foot-like pseudopods; and sporozoites, which have no means of locomotion but all contain a unique cellular organelle called an apical complex. Protozoa from all of these groups may infect the gastrointestinal tract of humans, as well as that of other mammals. Protozoa have various and complex life cycles which affect the epidemiology and pathological effects of the organisms. Most protozoa can form cysts that allow them to resist harsh environmental conditions until an appropriate host is found. It is the cyst form that is often found on food items or in the environment and accidentally ingested. Intestinal protozoa are not often transmitted directly from person to person; however, they can be transmitted by anal intercourse, with documented outbreaks having occurred among men who have sex with men. Cryptosporidium is a small organism present in most surface water in the United States. It can cause watery diarrhea for several weeks and is often accompanied by a mild fever, abdominal cramping, and fatigue. It can also lead to chronic diarrhea, but it is usually self-limited in immunocompetent individuals. In immunodeficient patients, particularly those with human immunodeficiency virus (HIV), it can be a severe infection for which few good treatments are available. In 1993, cryptosporidium entered the drinking water supply in Milwaukee and was responsible for making 400,000 people ill and for over 100 deaths.
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Cyclospora cayetenensis (cyclosporiasis) may be seasonal or outbreak related. Outbreaks are usually caused by contaminated food items because even thorough washing is not always able to remove all cysts from affected vegetables. Many people who are infected are asymptomatic, but others may have mild to moderate diarrhea. Antibiotic treatments are available if necessary. Amebiasis is caused by Entamoeba histolytica a pathogenic amoeba infecting over 10 percent of the world’s population and killing 100,000 people every year. E. histolytica is more commonly found in urban areas with up to 90 percent of cases being asymptomatic. Depending on host factors and the number of cysts ingested, its symptoms range from mild to severe diarrhea that may resolve spontaneously or result in severe dehydration or even colitis. Less commonly, E. histolytica can also move through the wall of the intestine causing amoebic abscesses in other parts of the body, often the liver. These can be fatal if not appropriately treated. Giardia lamblia is fairly common in all parts of the world and is seen in North America in returning travelers and in hikers who drink contaminated, unpurified water. About 50 percent of infected persons are asymptomatic with others suffering from watery diarrhea. Medical treatments exist, but the infection may resolve itself. Other common diarrhea-causing parasites include species from the isospora, microsporidia, and balantidium families. Both protozoal and helminthic parasitic infections of human intestines are responsible for a very significant burden of disease throughout the world. The majority of these diseases are both treatable and preventable with increased education, awareness, and basic hygiene measures. SEE ALSO: Parasitic Diseases. Bibliography. Stephen L. Hauser, Dan L. Longo, and J.
Larry Jameson, Harrison’s Principles of Internal Medicine 15th ed., Eugene Braunwald, Anthony S. Fauci, and Dennis L. Kasper, eds. (McGraw-Hill Professional Publishing, 2001).
Barry Pakes M.D., M.P.H. University of Toronto
Iran This country in central Asia, known until March 21, 1935 as Persia, remains one of the most powerful countries in its region. It was ruled by the Shah until 1979 when, after the Iranian Revolution, it has been the Islamic Republic of Iran. It has a population of 69,019,000 (2004) and has 85 doctors and 259 nurses per 100,000 people. There has been a long history of medical research in Persia, with references to medicine in the Stele of Hamurabi from the ancient world. As a great center of learning, many medical doctors worked in the region during the Achaemenian Empire, and in the period of Greek rule that followed. In medieval times, doctors were trained at the university at Ahvaz, and the great Arab medical writer Avicenna (980–1037 c.e.) practiced in Persia. The medical scholar and surgeon, Jorjani (1042–1136) spent much of his life in northeast Iran at what is now Gorgan. During the early modern period, medical specialists such as Hoseini Nourbakhsji, Mozafar Shafai and Hakim Momen made great advances in surgical procedures and medical techniques. European medical practices were first introduced into Iran with the establishment in 1850 of the Darol Fonoun Polytechnic, with doctors such as the Austrian Dr. Polack, and others such as the Dutchman Dr. Schlimmer and Dr. Albaux also working at the Darol Fonoun Polytechnic. The Treatise on Small-Pox Vaccination was one of the first books printed in the city of Tabriz. In the 20th century there were efforts to modernize medical procedures and medical facilities. This saw new hospitals being built throughout the country. The Sanatorium at Sakhtessar in the 1930s was hailed as an example of this modernization process, as was the Nemazi Hospital in Shiraz, opened in March 1956. The Iranian Society of Microbiology was founded in 1940, and an expansion of the university system in the 1960s saw many more doctors trained in the country. The medical congresses of the Iranian Medical Society were held annually from 1951 and the Near and Middle East Medical Congress was held in Iran in October 1962. The Iranian Revolution led to many doctors leaving Iran to work overseas, but the trend only exacerbated a problem that had faced the country for some years. In March 1976, there were 12,196 physicians in Iran,
Iraq
with about 10,000 others who were practicing overseas. Approximately some 7,000 more left Iran in the first decade after the Revolution, and only 750 new doctors graduated from Iran’s medical schools from 1980 until 1986. This has led to a massive shortage of trained doctors in the country, which has partially been addressed during the 1990s and early 2000s, with government and the private sector spending about $300 billion on healthcare in 2006. Nowadays, some 46 percent of doctors in Iran are women. There are now some 730 hospitals and clinics in the country, which have a capacity of 110,797 beds. The medical problems facing people in the country included typhoid, cholera, tuberculosis, and malaria. The government introduced major malaria eradication measures from 1960, resulting in a very marked decline in the disease. Improvements in sanitation and the provision of fresh water have seen marked declines in typhoid and cholera, with tuberculosis under control. New medical problems include a rising rate of HIV/AIDS, although it is still low compared to many other countries, and also a rise in diseases and conditions associated with greater affluence such as cancer, obesity, and diabetes. SEE ALSO: AIDS; Obesity; Smallpox; Typhoid. BIBLIOGRAPHY. Cyril Elgood, Medicine in Persia (P.B.
Hoeber, 1934); Cyril Elgood, A Medical History of Persian and the Eastern Caliphate: From the Earliest Times Until the Year AD 1932 (Cambridge University Press, 1951); Cyril Elgood, Safavid Medical Practice … Between 1500 AD and 1750 AD, (B. Luzac, 1970); “History of Medicine in Iran,” www.caroun.com/Medicine/IranHistory/After Islam-2.htm (cited August 2007). Justin Corfield Geelong Grammar School, Australia
Iraq This Middle Eastern country, located across the Tigris and Euphrates Rivers, was formed after World War I, and officially gained its independence from the Ottoman Empire on October 1, 1919, and from Britain on October 3, 1932. It has a population of
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25,375,000 (2004) and has 55 doctors and 236 nurses per 100,000 people. There are descriptions of medical procedures on cuneiform tablets from Babylon, dating from about 2000 b.c.e., and Babylon and later Assyria were centers of great learning. In medieval times, the great Arab surgeon Avicenna (980–1037 c.e.), author of Canon of Medicine, was born in Baghdad, which was the center of medical research in the region until 1258 when it was sacked by the Mongols. In 1401, it was again sacked by Tamurlane, and then ruled by the Ottoman Turks, with the city going into decline. In 1920, the Iraqi Medical Society was formed, but it was not until after World War II that the city boomed, with the wealth created from the sale of oil. Much of the teaching of medicine took place at the University of Baghdad which published the Journal of the Faculty of Medicine each quarter, and also the Journal of the College of Dentistry. The Mosul branch of the University of Baghdad was founded as a separate university in 1967, and it also has a College of Medicine. The University of Basrah, founded in 1964, has a Faculty of Medicine, and al-Nahrain University (formerly Saddam University), founded in 1993, has a College of Medicine. The rise to power of the Baath Party in Iraq in 1968 coincided with a period of great wealth for the country, and it was not long before the healthcare system became one of the best in the region. In 1976, the Iraq Cancer Registry was established, being one of the first to be formed in the region. However, the start of the Iran–Iraq War led to a decline in spending on medical care, and the continued rule of Saddam Hussein caused some highly-trained medical personnel to leave Iraq and settle in the West. By 1983, the area around Baghdad known as the Baghdad Governorate, which included about 29 percent of the population, had 37 percent of the hospital beds, 42 percent of the government clinics and 28 percent of the paramedical personnel. This demonstrated that although the focus of the healthcare system was on the capital, as it is in most other countries, the distant parts of the country were not totally neglected. The health problems faced in Iraq until the 1940s were largely to do with poor sanitation and lack of access to fresh water. With the pollution of irrigation canals by both humans and animals, cholera, typhoid, malaria, and tuberculosis were common, along with
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trachoma, influenza, measles, and whooping cough. The prevalence of all of these was massively reduced during the 1950s, 1960s, and 1970s. By the 1980s with the decrease in expenditure on medical care, there was a rise in many of these diseases, especially in rural areas. This was exacerbated by the international sanctions imposed on the country after the invasion of Kuwait in August 1990. There have also been problems concerning a large rise in cancer cases which many commentators have associated with the use, by the U.S. military in Desert Storm in 1991, of depleted uranium. The Iraqi government raised this issue, going as far as issuing a postage stamp in 2001 showing two badly scarred children with the caption “DU bombing crime against Iraqi people.” Since the invasion of Iraq in 2002, there has been a major change in the medical services of the country. Even though there has been money spent on the health services by the new government, the insurgency which followed the invasion, and daily bombings throughout the country, has resulted in many more medical personnel leaving Iraq for overseas, and those who remain being overworked dealing with emergency casualties of the fighting, and unable to deal with the health prevention programs, elective surgery, and other medical problems with which they would otherwise have been able to deal. SEE ALSO: Cancer (General); Typhoid. BIBLIOGRAPHY. al-Nakshabandi Usama Nasir, Medical
Manuscripts of the Iraq Museums Library (Dar al-Hurriya, 1981); Hashim al Witry, Health Services in Iraq (New Publishers Iraq, 1944); Moses K. der Hagopian, Public Health in Iraq: The First Half Century (Ministry of Culture and Information, Republic of Iraq, 1981). Justin Corfield Geelong Grammar School, Australia
Ireland With a per capita income of $41,100, Ireland is the eighth richest nation in the world. Among European countries, only Luxembourg ($65,900) and Norway ($42,800) report higher per capita incomes. The United
Nations Development Programme’s (UNDP )Human Development Report ranks Ireland’s standard of living as the fourth highest in the world, and healthcare is widely available. Historically, an agricultural economy, Ireland has transformed itself into a major export giant. Between 1995 and 2004, Ireland averaged a seven percent growth rate. Inflation (2.4 percent) and unemployment (4.3 percent) are under control; however, a tenth of the population lives in poverty. Income disparity also exists, and Ireland is rated 35.9 on the gini index of inequality. The poorest ten percent of the population is able to claim only two percent of the country’s wealth as opposed to 35.9 percent for the wealthiest 10 percent. The Irish health system operates through a combination of private insurance and public subsidies. Government spending on health is high, and the government directs an average of 16 percent of the total budget to health programs. Health expenditures comprise 7.3 percent of the Gross Domestic Product (GDP), and the government allots $2,496 per capita for health. Nearly 80 percent of all health spending originates with the government, but only 0.8 percent of that funding is used for social security. Ireland’s social insurance and social assistance system covers full-time employees and self-employed and part-time workers whose earnings exceed a base income. Recipients are the elderly, the disabled, and survivors. Cash benefits are paid to the seriously ill, parents on leave for the birth or adoption of a child, the unemployed, and injured workers. Irish residents whose family income is below a certain level are issued a medical card that allows them to receive medical care, medications, hospital services, out-patient care, dental care, medical devices, and maternity and infant care free of charge. Parents are awarded a cash grant upon the birth of each child. Private sources provide just over a fifth of total health expenditures, and 61.90 of that amount is derived from out-of-pocket expenses. There are 2.79 physicians, 15.20 nurses, 4.27 midwives, 0.56 dentists, and 0.07 pharmacists per 1,000 population in Ireland. The 4,062,235 people of Ireland have a life expectancy of 77.73 years, with females outliving males by an average of six years. Literacy is universal (99 percent), and all Irish in the relevant age groups are enrolled in primary and secondary school. Safe drinking water and improved sanitation are available throughout Ireland. Despite the fact that 88.4 percent of the population identify themselves as Roman Catholic,
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The Irish health system operates through a combination of private insurance and public subsidies. Government spending on health is high, and the government directs an average of 16 percent of the total budget to health programs.
birth control is widely practiced; and the government sponsors a number of family planning programs. On the average, Irish women give birth to 1.86 children each. All births occur in the presence of trained attendants. Natural births are widespread, and Ireland has one of the highest rates in the developed world. The Maternity and Infant Care Scheme has been initiated to provide care to pregnant women and new mothers free of charge. The adjusted maternal mortality rate is low at five deaths per 100,000 live births. Between 1990 and 2004, infant mortality fell from eight to five deaths per 1,000 live births, and underfive mortality dropped from 10 to six deaths per 1,000 live births. The current infant mortality rate is 5.31 deaths per 1,000 live births. Six percent of infants are underweight at birth. Ninety percent of infants are immunized against tuberculosis. The immunization rate for diphtheria, pertussis, and tetanus (DPT1) is even higher at 96 percent; however, only 89 percent of infants receive the DPT3 vaccination. Rates for other
inoculations range from the low to the high eighties: Polio and Haemophilus influenzae type B (89 percent each) and measles (81 percent). Agricultural runoff has polluted the water of the Emerald Isle, creating a health threat for residents of surrounding areas. HIV/AIDS has also threatened health in Ireland, and the country has a 0.1 percent adult prevalence rate. Some 2,800 people are living with the disease, but less than 100 have died from HIV/AIDS or its complications. Other communicable diseases also present periodic problems in Ireland. In August 2000, an outbreak of measles occurred. Ireland was one of several countries to identify cases of severe acute respiratory syndrome (SARS) in spring 2003. Heart disease is a leading cause of death in Ireland, and the government has made the promotion of healthy lifestyles a major priority, including prevention and early detection of cancer. SEE ALSO: Healthcare, Europe.
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Bibliography. Spencer Di Scala, Twentieth Century Eu-
rope: Politics, Society, Culture (McGraw-Hill, 2004); Sandra Halperin, War and Social Change in Modern Europe: The Great Transformation Revisited (Cambridge University Press, 2004); Martin A. Levin and Martin Shapiro, eds., Transatlantic Policymaking in an Age of Austerity: Diversity and Drift (Georgetown University Press, 2004); Jeremy Rifkin, The European Dream: How Europe’s Vision of the Future Is Quietly Eclipsing the American Dream (Jeremy P. Tarcher/Penguin, 2004); Peter Taylor-Gooby, New Risks, New Welfare: The Transformation of the European Welfare State (Oxford University Press, 2004). Elizabeth R. Purdy, Ph.D. Independent Scholar
Iridology Iridology, also sometimes known as iridodiagnosis, is a medical practice with which doctors and others study the eyes of a patient to try to determine major problems in other parts of the human body. As such, it is not a treatment but a form of diagnosis. The first time that iridological practices were used, although the name was not coined until much later, was in the Chiromatica Medica, written by Philippus Meyeus and first published in 1665. It was reprinted five years later, and again in 1691, and mentioned some doctors looking into people’s eyes to see whether there are any other problems with the patient. The idea was more formalized by the Hungarian physician Ignatz von Péczely who used the German word Augendiagnostik which translates as “eye diagnosis.” The idea apparently came to him after he was treating a person for a broken leg and noticed particular streaks in the eye which were similar to those he had noticed in an owl that had a broken leg many years earlier. However, August von Péczely, the nephew of Ignatz von Péczely, rejected the idea as a myth at the First International Congress of Iridology, held in Brussels, Belgium, in October 2000. Iridology continued in Germany where Pastor Felke, a homeopathist, established the Felke Institute in Gerlingen. However, many scientists dismissed the idea, although some researchers in recent times have suggested that there might be a number of nonvisual
functions of the eye with Dr. D. A. Waniek, as recently as 1987, postulating that this might well be the case. During the 1950s, there was increased popularity for iridology in the United States, with Bernard Jensen, an American chiropractor, giving many classes on his method of diagnosis. Jensen had been critical of the exposure of the body to toxins and urged for natural foods to be used as detoxifiers, and claiming to be able to diagnose some aspects of bad diet by observing the eyes of patients. Jensen wrote about his theories in Iridology Simplified (2nd ed., 1980). In 1979, the Journal of the American Medical Association allowed three iridologists to study photographs of irises to see whether they could identify kidney disease, and found their diagnoses were in disagreement with each other and inaccurate. This has not stopped the publication of a large number of books on iridology including the Canadian Journal of the Science and Practice of Iridology, and there is also the Israeli Center for Advances in Multidimensional Iridology. The 2nd International Congress of Iridology was held at Thessaloniki, Greece, in October 2001, the 4th International Congress of Applied Iridology was held on May 18–21, 2000, and the First Integrated Iridology Conference was held on March 9–11, 2001, in Sydney, Australia. SEE ALSO: Ophthalmologist; Ophthalmology; Optom-
etrist.
Bibliography. Stephen Gabriel Allen, Iris Diagnosis: A
Handbook of Iridology (Goulburn Naturopathic Centre, 2006); E. Ernest, “Iridology: Not Useful and Potentially Harmful,” Archives of Ophthalmology (v.118/1, 2000); A. Simon, D. M. Worthen, and J. A. Mitas, “An Evaluation of Iridology,” Journal of the American Medical Association (v.242/13, 1979); John Vriend, Eyes Talk: Through Iridology to Better Health (Lothian Books, 1989). Justin Corfield Geelong Grammar School, Australia
Irritable Bowel Syndrome Irritable bowel syndrome (IBS) is one of the most common gastrointestinal disorders encountered in
a clinic. It is a bowel disorder lacking any detectable structural abnormalities in which abdominal discomfort or pain is associated with defecation or a change in bowel habits. Other IBS symptoms include abnormal stool frequency (more than three per day or less than three per week), abnormal stool form (hard or watery), abnormal stool passage (urgency or feeling of incomplete evacuation), passage of mucus, and a heightened sensation of bloating or feeling of abdominal distention. Psychological stresses can influence the onset of IBS. Symptoms of IBS can be alleviated by dietary avoidance of certain food, pharmacological agents, and behavioral-cognitive therapy. Symptoms IBS is a disease of no obvious pathological abnormalities. It is a disorder that primarily affects the young. Until recently, IBS was thought to be somatic manifestations of psychological stress. Typically, patients with IBS are young and present symptoms before the age of 45. Symptoms of IBS include abdominal pain, altered bowel habits, gas and flatulence, and upper gastrointestinal symptoms. The most consistent clinical feature of IBS is the alteration in bowel habits. The most common pattern is the alternation of constipation and diarrhea and with one being the dominant symptom. Initially, constipation occurs on an occasional basis progressing to a steady phase in which laxative treatments are no longer effective. Due to the prolonged retention of the stool in the colon, the stool is dehydrated and is usually hard. The constipation phase of IBS may last for weeks or months interrupted by brief episodes of diarrhea. If diarrhea is the predominating symptom, small, loose stools of volume less than 200 mL is the norm and the patients may also pass large amounts of mucus. Emotional stress and eating can aggravate diarrhea. Blood in the stool is not a feature of IBS unless it comes from hemorrhoids. Even though IBS patients present with constipation and diarrhea, they generally do not present with weight loss as a consequence of malabsorption. IBS patients also frequently complain of increased passing of gas or belching and complain of distended abdomen. Although some IBS patients may actually have increased production of gas, studies have actually shown that most IBS patients generate normal amount of intestinal gas. Rather, IBS patients have
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impaired transit and tolerance of intestinal gas leading to indicated symptoms. Up to 50 percent of IBS patients also complain of symptoms in the upper gastrointestinal region. These include heartburn, nausea, dyspepsia, and vomiting. Abdominal pain in IBS patients is highly variable in location and quality. The pain is frequently described as crampy and/or a constant ache. Risks IBS accounts for up to 3.5 million physician visits a year in the United States. It is estimated that up to 50 percent of those with symptoms consistent with a diagnosis of IBS never seek a doctor’s care. Those who do seek medical advice often had a major life event prior to seeking help (e.g., death in the family). Although IBS is a global disease, social and cultural factors affect the presentation and the diagnosis of IBS. In the West, it is estimated that up to 20 percent of adults show symptoms consistent with diagnosis of IBS. In the Western hemispheres, women have a higher incidence of the condition and are more likely to consult a physician. In south Asia, men in India have a higher incidence of IBS. In South Africa, IBS symptoms are more prevalent in black, urban dwellers than black, rural dwellers. In the United States, prevalence is equal between blacks and whites. Diagnosis The diagnosis of IBS requires the patient to have two of the three following clinical features developed by the Rome Consensus Committee (Rome II Criteria). In order to meet the diagnosis, patients, in the preceding year, have to have at least 12 weeks of abdominal pain or discomfort that is relieved with defecation, experience onset associated with stool frequency, and have onset associated with change in stool appearance and form. The Bristol Stool Form Scale is also utilized to describe the seven types of stool morphology. The scale includes descriptions of stool that ranges from “separate hard lumps like nuts” to “smooth sausagelike” to “watery, no solid pieces.” Causes The pathogenesis for IBS is poorly understood and explanations are numerous. They include abnormal motor and sensory functions in the gut, central nervous dysfunction, psychological disturbances, and stress.
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Specifically, the pathology includes or leads to abnormal gut motility due to exaggerated sensory response, heightened and altered sensation to visceral and pain stimulation in the gut or in the central nervous system, and mucosal inflammation. Studies have shown that IBS patients have lower threshold of sensation to pain and gastrointestinal distention. Studies have also shown that infection may influence the pathogenesis of IBS as up to 30 percent of patients develop symptoms compatible with IBS after episodes of bacterial gastroenteritis. Studies have found that women and patients with increased life stressors at the onset of gastroenteritis are at increased risk for developing “postinfectious” IBS. Increased numbers of inflammatory cells have been found in the gastrointestinal linings and some investigators have suggested that chronic inflammation contributes to alterations in motility or visceral hypersensitivity. Treatment IBS treatments are broad and include several categories: dietary therapy, pharmacological therapy, and behavior therapy. IBS patients are encouraged to avoid fatty foods and caffeine as they are poorly tolerated. Foods that exacerbate bloating, diarrhea, and pain are to be avoided. These include alcohol, cabbage, cauliflower, raw onions, grapes, plums, and raisins. Studies have shown that a high-fiber diet has little value for IBS patients. Pharmacological interventions include agents that are used to relief the symptoms of spasmodic gut, diarrhea, and constipation. Additionally, agents used to treat intestinal infections have been found to be effective in some IBS patients. Low-dose tricyclic antidepressants and serotonin receptor agonists and antagonists are also found to be helpful in some subsets of IBS patients. Last, because IBS manifestations are aggravated by stress and emotional distress, cognitive-behavioral therapies and relaxation techniques appear to be beneficial in some patients. SEE ALSO: Constipation; Diarrhea; Digestive Diseases
(General); Stress.
Bibliography. Thomas E. Andreoli, et al., “Irritable Bow-
el Syndrome,” in Cecil Essentials of Medicine (Saunders, 2003); Brenda J. Horwitz and Robert S. Fisher, “The Irritable Bowel Syndrome,” New England Journal of Medicine (v.344/24, 2001); “Irritable Bowel Syndrome,” Mayo Clinic,
www.mayoclinic.com/health/irritable-bowel-syndrome/ DS00106 (cited February 2007). James S. Yeh Boston University School of Medicine
Israel This Middle Eastern country was founded in 1948 from what had been the British mandated territory of Palestine. As the only Jewish state in the world, it has had a policy of encouraging Jewish people from all over the world to settle in the country, resulting in one of the most culturally diverse populations in the world. Although there are many references to medicine and medical treatment in surviving ancient Jewish texts, the modern history of Israeli medicine effective starts on January 11, 1912, with the establishment of The Hebrew Medicinal Society for Jaffa and the Jaffa District. There were nine doctors present at the meeting, from 32 Jewish physicians living in what became Israel. In 1913, the Hebrew-Speaking Physicians’ Society was established and soon accepted membership from Hebrew-speaking doctors who lived outside the Holy Land. By 1914, there were 60 Jewish doctors in the Holy Land, and the two organizations started to cooperate, merging after World War I to become the Hebrew Medical Association in the Land of Israel (HMA). In 1920 the HMA started publishing its quarterly journal Harefuah. One of the major focuses of the medical services in what was then the British mandated territory of Palestine was the improvement of the sanitation in the region. With cholera, typhoid, malaria, and tuberculosis being prevalent, the provision of drinking water to all parts of the territory, as well as diagnosis of problems and money spent to help prevent the spread of these diseases all helped. By 1939, the HMA had grown significantly in membership and its importance, and with the formation of the State of Israel, the HMA became the Israel Medical Association (IMA). Its initial energies were devoted to protecting doctors working in private hospitals, but with Israel spending considerable funds on establishing a government health sector from 1948
Italy
to 1963, the IMA started to help support doctors in public hospitals, as well as help with the formulation of Israeli government policy. From 1965 until 1997 it published the Israel Journal of Medical Sciences, which was superseded from 1999 by the Israel Medical Association Journal. It was not long before a number of other medical societies were established in Israel. These included the Israel Society of Allergology, founded in 1949; the Israel Society of Clinical Pediatrics, founded in 1953; the Israel Gerentological Society was founded in 1956; the Israel Society of Internal Medicine, founded in 1958; the Israel Society of Geriatric Medicine, founded in 1963; and the Society for Medicine and Law in Israel, founded in 1972. There are also many medical research institutes in the country, the most well-known being the Rogoff-Wellcome Medical Research Institute, founded in 1955. Some 70 percent of people in Israel are covered by the Kupat Holim, the sick fund run by Histadrut (the General Federation of Labor in Israel). Another 20 percent covered by insurance from other organizations, with only 10 percent of the population not covered by health insurance. Many of the medical problems now faced by doctors in Israel are connected with a high life expectancy, and affluent lifestyle. These include cancer, obesity, diabetes, and heart disease. There have also been an increasing number of cases of hepatitis and HIV/AIDS The Republic of Israel has a population of 7,047,000 (2006), and has one of the highest doctor to population ratios in the world, with 385 doctors and 613 nurses per 100,000 people. SEE ALSO: AIDS; Cholera; Malaria. Bibliography. James H. Cassedy, “Medical History in
Israel,” Bulletin of the History of Medicine (v.43/4, 1969); A. Michael Davies, Health and Disease in the Holy Land: Studies in the History and Sociology of Medicine from Ancient Times to the Present (Edwin Mellen Press, 1996); “Israeli Medical Association: Historical Background,” www. ima.org.il/EN; Shifra Shvarts, “Health Reform in Israel: Some Aspects of Seventy Years of Struggle 1925–1995,” Social History of Medicine (v.11/1, 1988). Justin Corfield Geelong Grammar School, Australia
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Italy The Italian Republic has a per capita income of $28,700, the 28th highest in the world. Aggregate figures are somewhat misleading because the economies of the northern industrial area and the agricultural south are vastly different. Most poverty in Italy is found in the south, which has an unemployment rate of 20 percent as compared to an overall unemployment rate of 7.7 percent. Nearly 66 percent of southern Italians are poor, making them dependent on welfare for survival. Italy is ranked 36 on the Gini index of inequality, and the richest 10 percent of the population claims 26.6 percent of resources while the poorest ten percent hold only 2.1 percent. Evidence exists that as income disparities have expanded, the intensity of poverty has increased. Economic woes have led the Italian government to privatize social services and create a two-tiered welfare system in which the poorest Italians receive healthcare through government subsidies and more affluent Italians depend on private insurance. As a result of the privatization, funding for health and other social programs was seriously curtailed. No public kindergartens are available, and poor women find it difficult to work because of the paucity of child care. Consequently, these women remain dependent on welfare. Despite the lack of government for education at the lowest and highest levels, literacy rates are high. There is, however, some disparity between male (99 percent) and female (98.3 percent) literacy. All of the relevant population is enrolled in primary and secondary schools. Safe drinking water and improved sanitation are available throughout Italy. According to the United Nations Development Programme’s (UNDP) Human Development Report, Italy has the 17th highest standard of living in the world. An average of 11 percent of the total Italian budget is designated for health. With a spending rate of $2,266 (international dollars) per capita, the government directs 8.4 percent of the Gross Domestic Product (GDP) to healthcare programs. Just over three-fourths of health expenditures in Italy are government generated. Social security accounts for only 0.2 percent of government spending. The private sector is responsible for the remaining fourth of health expenditures, and 83.30 percent of private spending
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Italy has enjoyed a high pension allowance that is now considered excessive, and reform efforts are underway.
evolves from out-of-pocket expenses. There are 4.20 physicians, 5.44 nurses, 0.29 midwives, 0.58 dentists, and 1.15 pharmacists per 1,000 population in Italy. The social security program, which covers the elderly, the disabled, and survivors, is funded by employee (8.89 percent of earnings) and employer (23.81 percent of payroll) contributions and government supplements. The program is compulsory for all employed Italians, and special programs cover civil servants and the self-employed. Italy’s pension allowances have been considered excessive, and efforts are under way to reform the program. Illness and maternity coverage provides both cash benefits and medical care. New mothers receive 80 percent of their salaries from a month before the expected birth of a child to three to four months after birth. The parental leave policy provides additional leave for either parent at 30 percent salary at any time until a child turns 3 years of age. Special benefits are also provided for those suf-
fering from tuberculosis, with benefits payable for up to two years, plus a Christmas allowance. Italy’s population of 58.133,509 has a life expectancy of 79.81 years, the 14th highest in the world. Females outlive males an average of six years. Italy has the 15th lowest fertility rate among nations of the world, and women give birth to an average of 1.28 children each. Sixty percent of Italian women use some form of birth control even thought 90 percent of the population is Roman Catholic. The adjusted maternal mortality rate is low at five deaths per 100,000 live births. Between 1990 and 2004, infant mortality plunged from nine to four deaths per 1,000 live births. At the same time, under-5 mortality fell from nine to five deaths per 1,000 live births. Six percent of Italian infants are underweight at birth. Currently, the infant mortality rate is 5.83 deaths per 1,000 live births. Immunization rates are generally high in Italy. Ninetyeight percent of infants are immunized against diphtheria, pertussis, and tetanus (DPT1), 97 against polio, 96 against DPT3, 95 percent against Hepatitis B, 90 percent against Haemophilus influenzae type B, and 84 percent against measles. There are major environmental health concerns in Italy. Industrial emissions such as sulfur dioxide have polluted the air, and water sources have been tainted by industrial and agricultural effluents. The government needs to address the issue of inadequate waste treatment and disposal. Italy has a 0.5 percent adult prevalence rate of HIV/AIDS. Some 140,000 people are living with the disease, which has proved fatal to less than a thousand people. Italy was one of several nations that experienced outbreaks of severe acute respiratory syndrome (SARS) in spring 2003. That same winter, human influenza A/H3N2 surfaced. The leading causes of death are circulatory diseases, cancer, and transport accidents. Due to the immigration of around 40,000 females from the sub-Saharan area of Africa, the Italian government has been faced with the health problem of female genital mutilation (FGM). Health officials are forced to walk a tight line between protecting the health of young girls and respecting the cultures of immigrant families. Some hospitals have created special teams trained to deal with caring for girls who have undergone FGM. SEE ALSO: Healthcare, Europe.
Bibliography. Spencer Di Scala, Twentieth Century
Europe: Politics, Society, Culture (McGraw-Hill, 2004); Sandra Halperin, War and Social Change in Modern Europe: The Great Transformation Revisited (Cambridge University Press, 2004); Martin A. Levin and Martin Shapiro, eds., Transatlantic Policymaking in an Age of Austerity: Diversity and Drift (Georgetown University Press, 2004); Jeremy Rifkin, The European Dream: How
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Europe’s Vision of the Future Is Quietly Eclipsing the American Dream (Jeremy P. Tarcher/Penguin, 2004); Peter Taylor-Gooby, New Risks, New Welfare: The Transformation of the European Welfare State (Oxford University Press, 2004). Elizabeth R. Purdy, Ph.D. Independent Scholar
J Jamaica Jamaica is located in the Caribbean Sea, south of Cuba. It is the third largest island and the second largest country in the Caribbean, a tropical land of high, forested mountains that slope down to more than a thousand miles of sandy beaches. Although formally part of the British Commonwealth, Jamaicans are by and large the descendents of African slaves, and they have built a rich heritage and a relaxed culture. The island has a population of 2.76 million, growing at 0.8 percent annually. The birth rate is 20.82 per 1,000 people and the death rate 6.52 per 1,000 people. The migration rate is negative, with minus 6.27 migrants per 1,000 people. About 1 million Jamaicans have left the island over the past few decades, resettling in other parts of the British Commonwealth or in the United States; this movement is known as the Jamaican diaspora. The majority of Jamaicans live in the cities along the coast; the urbanization rate is 52 percent and the population density is high at 241 people per square kilometer. The national economy is increasingly based on tourism, but also relies on strong exports in bauxite and agricultural products. Per capita income is $2,900, and less than 2 percent of the population lives on less than $1 a day.
About 93 percent of Jamaicans have access to clean water and 80 percent can access sanitary facilities. Combined with a well-developed monitoring system, this has led to significant decreases in common infectious diseases. Life expectancy at birth is 71.54 for men and 75.03 for women, with a healthy life expectancy estimated at 64.2 for men and 65.9 for women. The infant mortality rate is fairly low at 15.98 per 1,000 people. Immunization rates for children are high. The fertility rate is 2.41 children per woman, and 66 percent of women use birth control. Maternal mortality is low, with 120 deaths per 100,000 live births. A trained attendant monitors 95 percent of births. The Ministry of Health oversees a network of 30 hospitals spread out across the island. There are 2,253 doctors working within the country, along with 4,374 nurses. The government allocates about $83 per capita on healthcare. Jamaicans have a fairly healthy indigenous diet based on root crops, fish, chicken, beans, and rice. Consumption of red meat is low. However, there is a high incidence of cardiovascular disease, leading to about one-third of all deaths. One in seven people smoke. Diabetes is another growing health issue, with 81,000 Jamaicans currently living with the disease. The World Health Organization estimates
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that that number will grow to 189,000 by 2030 at current rates. HIV/AIDS affects about 1.2 percent of the population, with an estimated 20,000 Jamaicans infected with the virus. This is low compared to the infection rate elsewhere in the Caribbean but could grow in coming years. In a 2000 survey of risk behavior by the Ministry of Health, one in two respondents said they did not use condoms regularly, one in two men and one in ten women had more than one partner within a year, one in four men and one in eight women had already contracted at least one sexually transmitted disease in their lifetime. One in nine reported regular use of marijuana. The government and other national organizations are working on improving AIDS education within the country. Young Jamaicans are more likely to die in car crashes or violent crime than any other cause. The country is an active transfer point for guns and drugs traveling between North and South America, and gang violence is common. There are more than 1,000 gang-related homicides per year.
With a life expectancy of 81.25 years among the population of 127,463,611, Japan is ranked sixth in the world in life expectancy.
SEE ALSO: AIDS; Diabetes; Marijuana Abuse. Bibliography. Arvilla Payne-Jackson and Mervyn C. Al-
leyne, Jamaica Folk Medicine: A Source of Healing (University of West Indies Press, 2004). Heather K. Michon Independent Scholar
Japan The Japanese people are among the healthiest in the world. As the world’s second most industrialized nation, Japan enjoys a per capita income of $31,600, ranking as the 20th richest nation. Japan reports no poverty level, and homelessness is virtually nonexistent in this eastern Asian nation. A rating of 37.0 percent on the Gini index of inequality is indicative of Japan’s status as the most equal nation in the world. Because the traditional Japanese guarantee of lifetime employment has begun to erode, the current unemployment rate stands at 4.4 percent. Only one percent of the population is considered illiterate, and
100 percent of all children are enrolled in school at the primary level and 99.5 percent at the secondary level. One hundred percent of all Japanese have access to safe drinking water and improved sanitation. The United Nations Development Programme (UNDP) ranks Japan seventh of 177 nations in overall qualityof-life issues. The first welfare programs in Japan appeared in the late 19th century. Since the end of World War II and the eradication of the huge military sector, the Japanese people have enjoyed expanded benefits of good health combined with substantial government resources. Since 1994, welfare rights have been protected by the Japanese constitution. Health expenditures have remained stable over the last decade. Currently, around two percent of the overall national budget is allocated to healthcare. Some 7.9 percent of the total Gross Domestic Product (GDP) is set aside for health expenditures, an increase from 5.8 percent in 1998. The government allots $2,244 (international dollars) per capita for health costs. Over 80 percent of total health expenditures are provided by govern-
ment at various levels. Around 90.10 percent of the 19 percent financed by the private sector involves outof-pocket expenditures. More than 80 percent of all government health expenditures are allocated to finance social security programs. Japan has 1.98 physicians, 7.79 nurses, 0.71 dentists, and 1.21 pharmacists per 1,000 population. Although Japan has lagged behind other heavily industrialized nations in subsidizing healthcare, a safety net for the neediest people is well established. Known as Nihongata shakai fukushi shakai, Japan’s welfare system is considered unique because it is based on the notion that family, community, and employers rather than the government share the bulk of responsibility for assisting the needy. The responsibility for public healthcare is shared among the national government, prefectures, and municipalities. With a life expectancy of 81.25 years among the population of 127,463,611, Japan is ranked sixth in the world in life expectancy. This is chiefly in response to widespread access to healthcare under a national health insurance plan that began in 1938 with a limited target population. In 1961, the public insurance policy was revised to mandate enrollment of all Japanese not otherwise ensured in a community-based healthcare plan. Since 1980, all employers require a 10 percent copayment for employees and 20 percent copayment for family members. Healthcare is also promoted through employer-provided stress-reducing facilities such as spas and leisure resorts. Like other industrialized nations, Japan has a rapidly increasing aging population. It is predicted that by 2015, one in four Japanese will be 65 or older. Modest copayments are required of individuals covered under Social Security insurance. In 1990, the government instituted the Gold Plan, which subsidizes home helps, day care, and short-term nursing home care for the elderly. In the late 1940s, concern over child and maternal health led to the passage of the Maternal and Child Health Care Law, the Child Welfare Law, and the Childbirth Assistance Program. Maternal mortality is extremely low in Japan with a rate of 8 deaths per 100,000 live births, and all births are attended by skilled personnel. Approximately 59 percent of Japanese women use some method of birth control. In 1994, the Angel Plan was introduced to address the government’s ongoing concern about the low fertility rate (1.4 children per woman). The Angel Plan en-
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courages women to become more fertile by making life easier for working mothers. Supportive measures include day nurseries, drop-in care for nonworking mothers, special centers for sick children, after-school programs, and counseling. However, the government has been criticized for not providing sufficient local support for the Angel Plan. Japan has experienced a growing divorce rate over the last several decades, leading to a rise in the incidence of single-parent families. Much criticism has been leveled against the Japanese government for creating welfare benefits designed to assist only those who live in traditional nuclear families. On the other hand, the government has been lauded for its commitment to mothers and children at risk. The Ministry of Health, Labor, and Welfare has been charged with overseeing a number of programs dedicated to maternal and child health that include education, counseling, and healthcare services. These programs support women from the onset of pregnancy and continue until children are enrolled in elementary school. Special care is taken for women experiencing highrisk pregnancies and for newborn infants. Awareness and prevention of breast cancer are also emphasized for all Japanese females. With an infant mortality rate of 3.24 deaths per 1,000 live births, Japan has the third lowest infant mortality rate in the world. The mortality rate of under-5s was reduced from 6 to 4 per 1,000 live births between 1990 and 2004. The government subsidizes all vaccinations in Japan, and 99 percent of all children under the age of 1 are immunized against measles, diphtheria, pertussis, and tetanus (DPT1 and DPT 3). Some 97 percent of under-1s are immunized against polio. Japan has only recently acknowledged the inherent problem of child abuse that has been a result of cultural acceptance of inviolable parental rights and which has threatened the health of Japanese children. Educators and the media have banded together to garner support for the children’s rights movement. Spousal abuse has also been addressed. In October 2001, the Law for the Prevention of Spousal Violence and the Protection of Victims went into effect, targeting education and prevention of domestic violence. Under the guidance of the Headquarters for the Promotion of Gender Equality, efforts have been made to provide counseling and support for victims, and the
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Joint FAO/WHO Expert Committee on Food Additives (JECFA)
police force has been reeducated in proper handling of domestic violence cases. Despite the escalating HIV/AIDS rate in much of Asia, the Japanese rate remains low at less than 0.1 percent. Attempts to eradicate communicable diseases have also been successful. Between 1990 and 2004, the incidence of tuberculosis in Japan was reduced from 71 cases per 100,000/population to 39. Efforts to prevent the spread of the common cold have led cold sufferers to wear face masks in public to prevent exposure to others. Japan has, however, experienced outbreaks of some preventable diseases. For instance, there was an outbreak of staphylococcal food intoxication in 2000, and in 2004, influenza and severe acute respiratory syndrome (SARS) surfaced in Japan. Concern for disease prevention led to the passage of the Law on Infectious Diseases in 1998, with special attention to the spread of sexually transmitted diseases (STDs). As a result, the Ministry of Education distributes age-appropriate material in Japanese schools to teach children how to avoid exposure to STDs. SEE ALSO: Healthcare, Asia and Oceania. Bibliography. Roger Goodman, Family and Social Pol-
icy in Japan (Cambridge University Press, 2002); Carlos Gerardo Molina and José Núñez del Arco, eds., Health Services in Latin America and Asia (Johns Hopkins University Press, 2001); Leonard J. Schoppa, Race for the Exits: The Unraveling of Japan’s System of Social Protection (Cornell University Press, 2006). Elizabeth Purdy, Ph.D. Independent Scholar
Joint FAO/WHO Expert Committee on Food Additives (JECFA) The Joint FAO/WHO Expert Committee on Food Additives (JECFA) is an international committee comprised of scientific experts who evaluate food additive safety as well as safety levels of contaminants, naturally occurring toxicants, and veterinary drug residues in foods. It formulates standards to deter-
mine acceptable food contamination levels and serves as a resource for governments wishing to formulate national food safety programs. Initially created in 1956 after a joint FAO/WHO Conference on Food Additives in 1955, the JECFA is managed jointly by the Food and Agriculture Organization (FAO) of the United Nations (UN) and the World Health Organization (WHO). The FAO is charged with helping developing countries modernize agriculture and improve nutrition, and generally lead the international initiative to overcome hunger. The WHO is the UN’s health agency charged with helping the world’s people reach the highest level of physical and mental health and social well-being. JECFA reports to both FAO and WHO, as well as to member countries of each agency and to the Codex Alimentarius Commission (CAC). The CAC is charged with developing and coordinating food standards and guidelines worldwide to protect consumer health. The JECFA sets food safety levels after conducting risk assessment of additives and contaminants; to make their determinations, they use information from the fields of microbiology, biotechnology, exposure assessment, and food chemistry, including analytical chemistry. To fulfill their responsibilities, the JECFA relies upon committees of experts. The FAO selects members with chemical expertise for specification development of food additive purity, for the analysis of veterinary drug residue levels in food, and for the assessment of data quality. The WHO selects members for the toxicological evaluation of substances being considered, the establishment of acceptable daily intakes (ADIs), and the providing of measurable health risk estimates. Both organizations select members who are responsible for exposure assessment. The JECFA establishes ADIs based upon available toxicological data. During this evaluation process, experts focus on standards that will allow for consistently appropriate quality during the manufacturing of commercial food products. For contaminants and naturally occurring toxicants, the JECFA determines provisional maximum tolerable daily intake (PMTDI) or the provisional tolerable weekly intake (PTWI) using a no-observed-effect level. In other words, when a certain consumption of contaminants and natural toxicants cannot be seen to cause an effect on humans, this becomes that substance’s PMTDI.
Joint United Nations Programme on HIV/AIDS
Most humans eat meat, and their food may contain residues of veterinary drugs given to the animal. The JECFA, therefore, determines maximum residue limits (MRLs) that can be found in specific animal tissues, milk, and eggs and still be considered safe for human consumption. These MRLs provide assurance that intake levels of animal product residue likely will not exceed the ADI with proper drug use. The JECFA regularly reviews evaluation processes to ensure upto-date risk assessments. As a result, the JECFA assumes a key role in worldwide standardization of food chemical hazard assessment. SEE ALSO: Food and Agriculture Organization of the Unit-
ed Nations (FAO); World Health Organization (WHO).
Bibliography. Food and Agriculture Organization of the
United Nations, http://www.fao.org; Joint FAO/WHO Expert Committee on Food Additives, http://www.who.int/ ipcs/food/jecfa/en/; World Health Organization, http:// www.who.int/en/. Kelly Boyer Sagert Independent Scholar
Joint United Nations Programme on HIV/AIDS UNAIDS, the Joint United Nations Programme on HIV/ AIDS, brings together the efforts and resources of 10 UN system organizations to the global AIDS response. Based in Geneva, the UNAIDS secretariat works on the ground in more than 75 countries worldwide. UNAIDS brings together in the AIDS response the efforts and resources of ten UN system organizations. The 10 UNAIDS cosponsoring organizations are: • Office of the United Nations High Commission-
er for Refugees (UNHCR)
• United Nations Children’s Fund (UNICEF) • World Food Programme (WFP) • United Nations Development Programme
(UNDP)
• United Nations Population Fund (UNFPA) • United Nations Office on Drugs and Crime
(UNODC)
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• International Labour Organization (ILO) • United Nations Educational, Scientific and Cul-
tural Organization (UNESCO)
• World Health Organization (WHO) • World Bank
The Cosponsors and the UNAIDS Secretariat comprise the Committee of Cosponsoring Organizations, which meets annually. UNAIDS has successfully worked with a number of outstanding personalities to strengthen awareness on AIDS. The UNAIDS Special Representatives are prominent individuals from the world of arts, science, literature, entertainment, sport, and other fields of public life who have expressed their desire to contribute to UNAIDS and to move the AIDS response forward. To mark its 10th anniversary, UNAIDS has appointed a number of new Special Representatives. The Unified Budget and Workplan The UNAIDS Unified Budget and Workplan (UBW) is a unique mechanism within the system. It is a two-year program budget and work plan that presents the response to HIV/AIDS of 10 different UN organizations (UNAIDS Cosponsors) and the UNAIDS Secretariat which together constitute UNAIDS. It specifies who does what, where, with how much money and where the resources come from. The UBW also includes a Performance Monitoring and Evaluation Framework so that progress can be measured, accountability ensured, and program adjustments be made. The UBW presents a comprehensive picture, both programmatically and financially, of the joint work on HIV/AIDS of eleven UN entities—ten UNAIDS Cosponsors and the UNAIDS Secretariat—at global and regional level. In addition, the UBW document provides summary information on the estimated country level resources of the Cosponsors and Secretariat. This revised version of the 2006–2007 Unified Budget and Workplan and its Annex contain the Programme Coordinating Board-approved changes made by the Cosponsors and the Secretariat in the Principal and Key Results in order to align the UBW with the recommendations of the Global Task Team on Improving AIDS Coordination among Multilateral Institutions and International Donors. This document also contains the revised achievement indicators of Principal and Key Results.
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This Framework, adopted by the 18th PCB in June 2006, is designed to support results-based management, to promote transparency, strengthen accountability, improve reporting, and reflect links between collective and individual levels of effort. It serves as a framework for monitoring and assessing outcomes of UNAIDS effort, promoting cohesiveness in tracking and reporting, and facilitating access to information on progress across UNAIDS. It is a mechanism for generating information for evidence-based decisionmaking in the Joint Programme. See Also: AIDS; AIDS—Living with AIDS. Bibliography. Joint United Nations Programme on
HIV/AIDS, AIDS Epidemic Update (World Health Organization, 2003); Joint United Nations Programme on HIV/ AIDS, Progress Report on the Global Response to the HIV/ Aids Epidemic, 2003: Follow-Up to the 2001 United Nations General Assembly Special Session on HIV/AIDS (World Health Organization, 2003). Jose S. Lozada Case Western Reserve University
Jordan Since 1999 when King Abdullah II ascended the throne of Jordan after the death of his father King Hussein, the government has been engaged in a series of political reforms designed to raise the standard of living in Jordan. Debt, poverty, and unemployment drain the government of much-needed resources. Some 30 percent of the population live below the poverty line, and around two percent live on less than $1 a day. Poverty eradication is a major element of reforms and is necessary to improve the health of the poorest segment of the population of 5,906,760. The official unemployment rate is 12.5 percent of the labor force, but the unofficial rate is 30 percent. With a per capita income of $4,700, Jordan ranks in the mid-range of world incomes. Income disparity is common, and Jordan ranks 36.4 on the Gini index of human inequality. The poorest 10 percent of the population claim only 3.3 percent of resources, while the richest 10 percent share 29.8 percent. The United Nations Development Programme’s (UNDP)
Human Development Report ranks Jordan 86th of 233 countries on general quality-of-life issues. Healthcare reforms have resulted in free care for those in need, and health insurance for children under the age of 5 is comprehensive. Free premarital exams are free at public health clinics. Throughout the kingdom, 200 health centers provide healthcare services, including perinatal care and family planning. Nongovernmental organizations (NGOs) and international agencies are integral to providing healthcare in Jordan. Commitment to healthcare has resulted in 10 percent of the total budget being earmarked for this purpose. The government spends 9.4 percent of the Gross Domestic Product (GDP) on healthcare, providing $440 (international dollars) per capita to meet healthcare needs. However, less than half (45.2 percent) of total health spending derives from government resources, and only 0.7 percent is targeted for Social Security. The private sector provides 54.8 percent of total healthcare spending, with 74 percent of that amount coming from out-of-pocket expenses. There are 2.03 physicians, 3.24 nurses, 1.29 dentists, and 3.12 pharmacists per 1,000 population in Jordan. Life expectancy in Jordan is 78.4 years, with women outliving men an average of five years. As is common in many Middle Eastern nations, male literacy (95.9 percent) is considerably higher than female literacy (86.3 percent). Primary school enrollment stands at 91 percent. Some 87 percent of females attend secondary school, as do 85 percent of males. Water supplies are threatened by drought and the lack of adequate natural fresh water resources, and Jordan is one of the 10 countries in the world most threatened by water shortages. Nevertheless, 91 percent of the population have access to safe drinking water. In urban areas, 94 percent of the population have access to improved sanitation, but only 85 percent of rural residents are able to meet this basic need. Jordan has been successful at reducing fertility rates, and 56 percent of women use birth control of some form. Between 1970 and 1990, the fertility rate dropped from 7.9 to 5.9 births per woman and is currently 2.63. The reduction in fertility is due in part to the work of the Supreme Population Council, which was established in 1973 as the National Population Council. The focus of reproductive health in Jordan is holistic, attempting to bring men and women together to foster reproductive health and to improve the
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Some 30 percent of the population live below the poverty line, and around two percent live on less than $1 a day. Poverty eradication is a major element of reforms and is necessary to improve the health of the poorest segment of the population of 5,906,760.
health of mothers and children. Skilled professionals attend all births, and 99 percent of women receive prenatal care. The current adjusted maternal mortality rate is 41 deaths per 100,000 live births. Jordanian infants die at a rate of 16.76 deaths per 1,000 live births, and male infants (20.04) are considerably more vulnerable than female infants (13.28). Between 1990 and 2004, infant mortality declined from 33 to 23 deaths per 1,000 live births, and under-5 mortality dropped from 40 to 27. One-tenth of all infants are underweight at birth, and 4 percent of under-5s fall into this category. Two percent of under-5s suffer from wasting diseases, and 9 percent experience growth stunting. The Jordanian government subsidizes all required infant immunizations; however, vaccination rates for tuberculosis are low (58 percent). Rates in other areas are more in line with what might be expected, and only 1 percent of infants fail to receive measles vaccinations. Some 96 percent receive diphtheria, pertussis, and tetanus (DPT1) immunizations, and 95 percent are vaccinated against
DPT3, polio, hepatitis B, and Haemophilus influenzae type B. Only 44 percent of under-5s receive oral rehydration therapy when needed. HIV/AIDS is under control in Jordan with a 0.1 percent adult prevalence rate. Some 600 people are living with this disease, which has proved fatal to approximately 500 people. The major causes of death in Jordan are cardiovascular diseases (42 percent), cancer (13 percent), and accidents (10.5 percent). The majority of visits to public clinics concern diarrheal diseases, respiratory infections, and hepatitis B and C. SEE ALSO: Healthcare, Asia and Oceania. Bibliography. Michael E. Bonine, ed., Population, Pov-
erty, and Politics in Middle East Cities (University Press of Florida, 1997); Helen Chapin Metz, ed., Jordan: A Country Study (Federal Research Division, 1991). Elizabeth R. Purdy, Ph.D. Independent Scholar
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Juvenile Rheumatoid Arthritis
Juvenile Rheumatoid Arthritis Juvenile rheumatoid arthritis (JRA) is the most common form of arthritis occurring in children. Juvenile rheumatoid arthritis does not represent a single disease but a constellation of disease processes which differ in their respective symptoms, treatments, and outcomes. Typically, JRA is clinically diagnosed if a child under the age of 16 has inflammation, limited motion, and swelling in at least one joint that lasts more than six weeks, provided that other diseases have been ruled out. However, in most cases, JRA is not a lifelong condition and symptoms may dissipate in weeks or months. JRA is not an early-onset form of adult rheumatoid arthritis but a distinctly separate disease. The key difference is that JRA causes chronic inflammation of the synovial membranes lining the joints, but this inflammation is not caused by an autoimmune attack as in adult rheumatoid arthritis. Patients with adult rheumatoid arthritis typically have elevated blood levels of an autoantibody called rheumatoid factor; this is unusual in JRA patients. There are three categories of JRA: pauciarticular, polyarticular, and systemic. The systemic form occurs nearly equally in both sexes, but the first two forms are much more prevalent in females. There is an overall bimodal age distribution, with diagnosis being commonly made between 1 to 3 years or between 8 to 12 years. Pauciarticular JRA affects approximately 50 percent of all JRA patients. It is defined as arthritis in one to four joints, most commonly involving the knee. A frequent and potentially serious complication of this form of JRA is iridocyclitis, an inflammation of the iris and ciliary body of the eye; all pauciarticular patients should receive regular ophthalmologist exams. Some patients, mostly females, have elevated blood levels of antinuclear antibodies and are at increased risk for iridocyclitis. Another subgroup, mostly males, have the HLA-B27 gene; these patients are at increased risk for developing ankylosing spondylitis, a severe form of arthritis that mainly affects the spine and sacroiliac joints. After several months of symptoms, pauciarticular arthritis patients often enter remission periods lasting years, and thus, this form of JRA carries a relatively good prognosis. Polyarticular JRA presents with a low-grade fever and at least five arthritic joints. Up to 30 percent of
JRA patients have this form of the disease. Typically, the arthritis is symmetrical and affects the same joints on both sides of the body. About 25 percent of these patients actually have elevated levels of rheumatoid factor in their blood, which is typically unusual in JRA. Polyarticular patients, especially those who are positive for rheumatoid factor, often have chronic disease courses. Systemic JRA, or Still’s disease, accounts for about 20 percent of JRA patients. The systemic form is characterized by high fever, rash, arthritic joints, swollen lymph nodes, enlarged liver and spleen, pericarditis, and pleuritis. Also, these patients have markedly elevated white blood cell counts. One in four patients with systemic JRA progresses to longterm severe arthritis. Early diagnosis and appropriate treatment provide the best chance for a favorable outcome. The goal is to reduce the inflammation, relieve pain, and control joint damage while maximizing function. Antiinflammatory drugs are the mainstays of treatment for all forms of JRA. The pauciarticular form of JRA often responds to nonsteroidal antiinflammatory drugs (NSAIDs) similar to aspirin, particularly naproxen. Injecting steroid drugs into affected joints is another common and effective treatment. For more severe cases, drugs such as methotrexate are used to suppress the proliferation of inflammatory white blood cells that attack the joints. The newer drugs etanercept and infliximab specifically bind to an inflammatory signal molecule, known as tumor necrosis fac-
Juvenile rheumatoid arthritis does not represent a single disease but a constellation of disease processes.
tor, preventing its role in sustaining the destructive arthritic process. Regardless of the therapy selected, a multispecialty healthcare team is usually required to provide coordinated care for the patient. SEE ALSO: Arthritis; National Institute of Arthritis and
Musculoskeletal and Skin Diseases (NIAMS); Orthopedics; Orthopedist; Rheumatoid Arthritis. Bibliography. Nicholas Athanasou, Pathological Basis of
Orthopaedic and Rheumatic Disease (Arnold, 2001); Ross Petty, Justine Smith, and James Rosenbaum, “Arthritis and Uveitis in Children: A Pediatric Rheumatology Perspective,”
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American Journal of Ophthalmology (v.135, 2003); Emanuel Rubin, et al., Rubin’s Pathology: Clinicopathologic Foundations of Medicine, 4th ed. (Lippincott Williams & Wilkins, 2005); Harry Skinner, Current Diagnosis and Treatment in Orthopedics, 3rd ed. (McGraw-Hill, 2003); Jennifer Weiss and Norman Ilowite, “Juvenile Idiopathic Arthritis,” Pediatric Clinics of North America (v.52, 2005). David B. Bumpass Francis H. Shen, M.D. University of Virginia Dino Samartzis, D.Sc., M.Sc., Dip. EBHC Harvard University and Erasmus University
K Kazakhstan Kazakhstan is located in Central Asia with a western border on the Caspian Sea. Formerly a part of the.Soviet Union, it is bordered on the north by Russia and on the south by Kyrgyzstan, Uzbekistan, and Turkmenistan. It shares an eastern border with China. At over 2.7 million square kilometers (over 1 million square miles), it is the largest state in Central Asia. More than two-thirds of the country is covered with desert and semi-arid steppes. Only 8 percent of the land is suitable for cultivation. Kazakhstan has abundant natural resources and ports on the Caspian Sea, but its economy has not yet found footing in the post-Soviet era. The population is 15,285,000 and growing at 0.352 percent annually. The birth rate is 16.23 per 1,000 and the death rate is 9.4 per 1,000. The country is losing 3.32 people per 1,000 to migration each year. Median age is 29.1 years. Life expectancy is 61.9 years for males and 72.84 years for females. Gross national income is $2,930 per person, with 19 percent living in poverty; there is low unemployment. Communicable diseases are responsible for 2 percent of mortality each year. After a long period of decline though the 1980s, rates of diseases such as tuberculosis, hepatitis, and diphtheria began to climb in the 1990s. The tuberculosis rate is 132 per 100,000, or
about 23,000 new cases a year. Vaccinations for TB were halted for a period in 2004 after more than 1,000 people reported bad side effects from an imported vaccine. Negative publicity surround the event has kept vaccination rates low for the last three years. There was also a measles outbreak in 2004 that sickened 1,200 people. The adult prevalence rate for AIDS is 0.1 percent, with about 12,000 believed to be infected with the virus. Noncommunicable diseases account for 85 percent of mortality in Kazakhstan, and of that number 57 percent are from cardiovascular disease. Risk factors for men include tobacco and alcohol use, high blood pressure, high cholesterol levels, and obesity. For women, the main risk factors are high blood pressure and cholesterol, obesity, tobacco use, and low intake of fruits and vegetables. There has been a sharp increase in cardiovascular diseases since 1990, and it seems to be happening to people at a younger age. With high alcohol use and widespread viral hepatitis, cirrhosis and chronic liver disease are also a frequent cause of illness and death. UNICEF places child mortality in Kazakhstan at 63 per 1,000 for infants and 73 per 1,000 for children under five. At least 75,000 Kazak children are in orphanages or other state-run institutions. This is a pattern seen around the former Soviet Union, as families have been put under increasing pressures as a result
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of independent and economic reorganization. The maternal mortality rate remains high at 210 deaths per 100,000 live births, despite 91 percent of women receiving prenatal care and 99 percent giving birth in hospital or with trained care. The government spends around $65 per capita on healthcare. Like all former Soviet states, Kazakhstan is trying to rebuild its medical system. During the Soviet period, the number of medical staff and hospital beds was emphasized over patient care. That has left a surplus of both: for example, there are 54,600 physicians in Kazakhstan, or 3.54 per 1,000 people. There are 93,800 nurses, or 6.01 per 1,000 people. The attempt to create a modern public-private system is going slowly, and many fear it will leave many people without care, as the average citizen will find it difficult to pay for care outof-pocket or afford monthly insurance premiums. See Also: Healthcare, Asia and Oceania. Bibliography. “Kazakhstan,” CIA World Factbook, https://
www.cia.gov/library/publications/the-world-factbook/geos/ kz.html(cited July 2007); “Kazakhstan: Fighting Tuberculosis Remains A Challenge,” IRIN: Humanitarian News & Analysis, http://www.irinnews.org/Report.aspx?ReportId=70772 (cited July 2007); UNAIDS: The Joint United Nations Programme on HIV/AIDS, “Kazakhstan,” http://www.unaids. org/en/Regions_Countries/Countries/kazakhstan.asp (cited July 2007); UNICEF, “Kazakhstan – Statistics,” http://www. unicef.org/infobycountry/kazakhstan_statistics.html (cited July 2007); World Health Organization, “A guide to statistical information,” http://www.who.int/whosis/en/index.html (cited July 2007); World Health Organization,”Health Care in Transition: Kazakhstan,” http://www.euro.who.int/document/e67903.pdf (cited July 2007); World Health Organization, “Highlights on Health: Kazakhstan,” http://www.euro. who.int/document/E88738.pdf (cited July 2007). Heather Michon Independent Scholar
Kelman, Charles D. (1930–2004) Charles D. Kelman was an American ophthalmologist who contributed to the development of cataract
surgery with the introduction of phacoemulsification (the Greek prefix “phakos” refers to the lentil shape of the lens) in 1967. This procedure, in which the lens clouded by a cataract is broken up by ultrasound, irrigated, and suctioned out, made cataract operations less invasive, allowing patients to recover faster. Rather than making a large incision in the eye and then removing the lens, the ophthalmologist inserts an ultrasonic tip into a small incision. The tip vibrates at thousands of times a second, breaking up the cataracts without damaging the surrounding tissue. Kelman was born in Brooklyn, New York, on May 23, 1930, and grew up in Queens where he studied at Forest Hills High School. He then enrolled at Tufts University in Boston, where he was awarded a Bachelor of Science. Kelman continued his medical studies at the University of Geneva. He completed his internship at Kings County Hospital and then worked as an ophthalmologist at the Manhattan Eye, Ear and Throat Hospital in New York. Kelman devoted the best part of his career to develop the technique of phacoemulsification, so that cataracts could be removed without having to take out the entire lens of the eye. After a series of false starts, he was apparently inspired by the ultrasonic probe technique with which dentists clean teeth. Phacoemulsification is now standard practice in cataract operations. Through the 1970s, Kelman perfected the postoperation recovery of patients, inventing artificial lenses which can be implanted in the patient’s eyes, rendering superfluous the thick glasses used until then. The technique developed by Kelman has been successfully developed by neurosurgeons and applied to operations to remove tumors from the brain and spinal cord. Although his research met with early suspicion and was initially considered dangerous, Kelman eventually received many prestigious awards for his phacoemulsification technique including the Albert Lasker Award for Clinical Medical Research (2004). He rose to international fame. President George H. W. Bush awarded Kelman the National Medal of Technology in 1992 and the ophthalmologist was inducted into the National Inventors Hall of Fame in Akron, Ohio, in 2004. Kelman died of lung cancer on June 1, 2004, in Boca Raton, Florida. SEE ALSO: Cataract; Ophthalmology.
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BIBLIOGRAPHY. Charles D. Kelman, Cataracts: What You
Must Know about Them (Crown Publishing Group, 1982); Charles D. Kelman, Through My Eyes: The Story of a Surgeon Who Dared to Take on the Medical World (Crown Press, 1985). Luca Prono Independent Scholar
Kenya Kenya is located in eastern Africa with a coastline on the Indian Ocean. Roughly the size of France, it is bordered by Ethiopia, Tanzania, Somalia, Uganda and Sudan. Kenya is home to many different ethnic groups, which contributes to the country’s rich culture—but also causes conflict that contributes to the political, economic and social problems that keep it from moving towards stability. Kenya’s population is currently estimated at 36,914,000 and is growing at 2.8 percent annually. The birth rate is 38.94 per 1,000 and the death rate is 10.95 per 1,000. Median age is 18.6 years. Life expectancy is 55.24 years for males, and 55.37 years for females. Gross national income is $530 a year, with 23 percent of the population subsisting on less than $1 a day. Three quarters of Kenyans work in agriculture. The unemployment rate is 40 percent within the service industry. Malaria is endemic along the coast and in the Western provinces. Respiratory illnesses follow as the second-leading cause of outpatient cases. Diarrhea is responsible for 4.7 percent of all outpatient services, with higher rates in Nairobi, the Rift Valley, and the Western provinces. Infection by intestinal worms is prevalent in the Eastern and Central districts, but low in the west. Although the AIDS rate has stabilized in recent years, the adult prevalence rate is still high at 6.1 percent, with an estimated 1.3 million cases. AIDSrelated deaths exceed 140,000 in recent years. Kenya has a robust strategic plan, and provides testing, counseling and drug therapy at all provincial and district hospitals. In the summer of 2006, the government announced that it would provide antiretroviral drug therapy free of charge. The number of
Girls in Kenya marry young and begin childbearing early, and the maternal mortality rate is 1,000 deaths per 100,000 live births.
patients receiving antiretroviral drugs has increased from 3,000 in 2002 to 54,000 in 2006. Child mortality rates have risen from 1990 levels, from 64 up to 79 deaths per 1,000 for infants younger than 1, and from 97 to 120 deaths per 1,000 for children aged 1-5. This translates to 163,000 deaths for children under five in 2005 alone. Immunization rates range from 70-85 percent. Twenty percent of children are underweight; 30 percent show signs of stunting. A quarter of Kenyan children marry in adolescence, and 27 percent go to work during their school years. The AIDS epidemic and low life expectancy among adults has created a huge population of orphans, totaling 2.3 million children under the age of 17. Female genital mutilation is practiced in Kenya, with about 32 percent of women having had some form of the procedure. These rates vary depending on the tribe. Girls marry young and begin childbearing early, with a total fertility rate of 4.82 children per woman. Abortion is illegal, but one interest group estimates that 300,000 abortions are performed within the country each year, and at least 2,600 women die from infection. Thirty-nine percent of women use contraceptives, 88 percent have at least some prenatal care, and 42 percent give birth with the help of a trained assistant. The maternal mortality rate is 1,000 deaths per 100,000 live births. Kenya has both public and a private medical facility, with about 3,000 government-run establishments and 872 private hospitals. Many institutions, especially those outside Nairobi and other large cities,
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are not always well-equipped. There are more than 4,000 physicians and 37,000 nurses working within the country. Patients often have to pay up front for medical services. See Also: AIDS; Healthcare, Africa. BIBLIOGRAPHY. “KENYA: ARVs Now Free in Pub-
lic Hospitals,” PlusNews, http://www.plusnews.org/report.aspx?reportid=39654 (cited June 2007); “Kenya,” UNAIDS, http://www.unaids.org/en/Regions_Countries/ Countries/kenya.asp (cited June 18, 2007); Joyce Mulama, “Enforcement of Abortion Law Problematic,” IPS Inter Press Service, http://ipsnews.net/interna.asp?idnews=24050 (cited June 2007); UNICEF, “Kenya,” UNICEF, http://www. unicef.org/infobycountry/kenya_statistics.html (cited June 2007); WHOSIS, “A Guide to Statistical Information at WHO,” http://www.who.int/whosis/en/index.html (cited June 2007). Heather Michon Independent Scholar
Kidney Cancer Kidney cancer accounts for about two percent of cancers in the United States, as of the year 2007. According to the Mayo Clinic, two-thirds of kidney cancer cases are in people over 60 years of age. Men are more likely than women to develop kidney cancer. Most people have two kidneys, located in their lower back. There are several types of kidney cancer. For example, adults are more likely to develop renal cell carcinoma (all known as renal adenocarcinoma), as compared to youths. Renal cell carcinoma is cancer of the cells that line the renal small tubules. Children are more likely than adults to develop a type of renal cancer called Wilms’ tumor, which affects primarily children under 8 years of age. Certain genes as well as birth defects can predispose a child to developing Wilms’ tumor—these high-risk children should be screened for the cancer every three months until they turn 8 years old, according to the United States National Institutes of Health. Most cases of Wilms’ tumor are curable, by surgery
alone or in conjunction with chemotherapy, immunotherapy, and/or radiation. Another rarer type of kidney cancer is transitional cell carcinoma. The transitional cells are the ones that line the tubes leading from the kidneys to the urinary bladder. They are thus in transition between renal and bladder-like properties. A transitional cell carcinoma may originate in the ureters or the bladder. Still rarer is a renal sarcoma, which is cancer of the connective tissue surrounding the kidney. Like many other cancer, early diagnosis and prompt treatment of kidney cancer yields a positive prognosis. Symptoms of kidney cancer include blood in the urine, unexplained and unyielding back pain, unintentional weight loss, fatigue, or even a lump in the abdominal area. Blood in the urine is called hematuria, and is always a cause for concern. Hematuria is sometimes not noticeable to the eye alone; in this case, the physician may find it during a screening or by a routine analysis of a urine sample, such as during an annual physical examination. In the case of Wilms’ tumor, there usually are not any symptoms present other than a lump in the child’s abdomen. Diagnosis of kidney cancer is much the same as other cancer diagnoses. A minimally to noninvasive method of detection is medical imaging. Options include a Computed Tomography (CT) scan, Magnetic Resonance Imaging (MRI), Ultrasound, or Itravenous Pyelogram (IVP). During an IVP, a dye visible by X-ray is injected into an arm vein. As this dye travels through the body, a series of X-ray images is taken. The images of interest capture the dye as it travels through the kidneys, ureters, and bladder. Any abnormal trajectories will be visualized on the X-ray films. This method works because tumors need new blood vessels to bring nutrition; IVP analysis can detect abnormal vasculature which may be feeding a tumor. If the IVP detects a potential transitional cell carcinoma, a cytoscopy is performed next. During a cytoscopy, a long, very narrow tube with a lens on one end is inserted into the bladder via the urethra, and used to inspect the cells lining these regions. A cytoscopy can also take a small tissue sample which can then be analyzed for the presence of cancer cells. A surgical biopsy may also be taken of the tissue area under suspicion. Noninvasively, urine can be tested for the
Children are more likely to develop a type of renal cancer called Wilms’ tumor, which affects primarily children under 8 years of age.
presence of cancerous cells which had been sloughed off into the urine. Once kidney cancer is diagnosed, treatment can begin. In the past, the most common treatment for renal cell carcinoma was surgical removal of the entire affected kidney; however, recently physicians have observed that removing only the tumor itself is just as effective, with a better recovery time. Even when removing the entire kidney, a surgeon will typically leave the surrounding lymph nodes and adrenal glands (hormone producing glands that rest above both kidneys) intact. Chemotherapy, Immunotherapy, and/or Radiation may also be used. One novel treatment method is called Arterial Embolization, whereby the blood vessels supplying the tumor are blocked intentionally, thus starving the tumor. Cryoablation is another novel technique to treat kidney cancer. This procedure involves using special needles inserted through the abdomen which can then repeatedly freeze and thaw the tumor. These freeze-thaw cycles are intended to kill the cells in the tumor. Transitional cell carcinoma is usually treated by surgical removal of the affected area, potential prophylactic removal of a portion of the bladder, and then chemotherapy. While there is no definite cause of kidney cancer, scientists and physicians have observed a set of risk factors that may predispose an individual to develop
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kidney cancer. For example, gender is a major factor in renal cell carcinoma. A male is greater than two times as likely to develop renal cell carcinoma as a female with the same characteristics. A general risk for renal cell carcinoma is smoking, particularly smoking pipes or cigars. (Cigarette smoking increases a person’s risk for developing transitional cell carcinoma.) Furthermore, obese people have an elevated risk of developing renal cell carcinoma. High blood pressure and exposure to radiation also increase a person’s risk; however, taking diuretics for high blood pressure may in fact also increase a person’s risk. Lowering an individual’s blood pressure through other means will decrease a person’s risk for developing kidney cancer. Finally, exposure to environmental toxins which may lodge in the kidneys and harm them is also a risk factor. A person who has or has had bladder cancer is at an increased risk for developing transitional cell carcinoma. SEE ALSO: American Association for Cancer Research
(AACR); American Cancer Society (ACS); Kidney Stones; Nephrology. Bibliography. Eric P. Cohen, Cancer and the Kidney
(Oxford University Press, 2005); Robert A. Figlin, Kidney Cancer (Cancer Treatment and Research) (Springer, 2003).
Claudia Winograd University of Illinois
Kidney Diseases (General) The bean-shaped kidneys, which are roughly the size of a human fist, lie on either side of the body in the middle of the back, just beneath the rib cage. Within each kidney, there are a million functioning units known as nephrons, which perform the vital functions of balancing concentrations of water, ions, salt, acids, potassium, and calcium in the body and removing contaminants from the blood stream. This balancing function also involves synthesizing, modifying, and secreting hormones and vitamins that influence other body functions. The kidney helps to regulate blood pressure and stimulates the formation of red blood cells. In a single day, around 200 quarts of fluid
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are filtered through the kidneys. Blood is received in the kidney from the renal artery, and filtered blood is returned to the body through the renal veins. Every day, around two quarts of waste fluids are channeled into the bladder where they are subsequently eliminated through the urethra as urine. Great progress in understanding kidney functions and diseases has taken place since the end of World War II. Increased research funding has been essential to this progress, and has precipitated advances in renal anatomy and physiology, biochemistry, pharmacology, bioenergetics, molecular, cell, and development biology, genetics and genomics. Physicians are now able to draw on new knowledge and technologies to deal with kidney diseases and injuries that would have proved fatal in the past. One of the most significant successes has been in the field of kidney transplants. The human genome project continues to provide researchers with great insight into the role of inheritance in the development of kidney diseases. Johns Hopkins University maintains an extensive online database of genetic aspects of kidney disease. When any aspect of essential kidney functions fails to operate properly, kidney diseases develop. The six warning signs of kidney disease are: burning or difficult urination, increased frequency of urination, bloody urine, puffiness around the eyes, swelling of the hands and feet, pain in the small of the back, and high blood pressure. Important factors in preventing kidney disease are controlling hypertension, maintaining a healthy weight, reducing salt intake, eating foods containing calcium and potassium, being physically active, and avoiding excess alcohol intake. The four major causes of kidney failure are diabetes, hypertension, glomerulonephritis, and polycystic disease. It is estimated that 20 million Americans suffer from kidney or urinary tract-related diseases. African-Americans are at higher risk than others for all incidences of kidney disease except polycystic disease. They are 20 times likelier than other Americans to develop kidney disease that results from hypertension. African-Americans also tend to develop kidney diseases at earlier ages than white Americans. The National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) is currently involved in a research initiative to develop a greater understanding of kidney disease in African-Americans.
While some disorders such as kidney stones may affect only one kidney, most kidney diseases are bilateral. Kidney diseases range from minor infections to progressive kidney failure. Approximately 100,000 Americans with kidney disease require dialysis or a kidney transplant. During dialysis, artificial kidneys take over the role of filtering the blood and returning cleansed blood to the body. While the process keeps kidney patients alive, it is not with side effects. Dialysis patients are prone to blood clots and infections. Patients new to dialysis may develop headaches, nausea, muscle cramps, anorexia, dizziness, and seizures. A 1998 study revealed that 86 percent of AfricanAmericans with kidney failure were on dialysis as opposed to 69 percent of Whites. A number of studies have shown that African-Americans tend to remain on dialysis, in part because they tend to have fewer complications and are likely to live longer than white dialysis patients. Advances in kidney transplants have been instrumental in removing hundreds of thousands of patients from dependence on dialysis and restoring quality of life despite the continued need for immunosuppressive drugs. Diagnosis Medical professionals are able to test for proper kidney function during routine office visits through urinalysis, the most frequently performed of all laboratory tests. Urinalysis provides physicians with information about unexplained renal insufficiency, urinary tract irregularities, high blood pressure, and potential renal dysfunction. Infections of the lower urinary tract are generally identified through urinalysis. Since most of these infections respond well to antibiotics, no further treatment is needed unless infections recur. Urinalysis may also be instrumental in diagnosing other diseases such as diabetes and high blood pressure. Glomerular Filtration Rate (GFR) is another widely used method of determining renal function, and abnormal GFR results may indicate the need for additional testing. Blood tests are important in determining kidney health because elevated levels of blood urea nitrogen (BUN), creatinine (a product of muscle metabolism), calcium, or phosphorus may suggest potential renal failure. Imaging tests may be performed to identify or rule out the possibility of kidney tumors. Such masses may be either cystic or solid. If a mass is cystic, no further action is needed.
When a mass is either solid or indeterminate, a biopsy may be performed to determine whether or not the growth is cancerous. Kidney disease may be diagnosed in response to warning signs that seem unrelated to kidney functions. Unexplained weight loss, for example, may indicate uremia or a possible malignancy. Rapid weight gain may be a sign of volume expansion. A skin rash may be a byproduct of allergic renal disease, connective tissue disease, vasculitis, or atheroembolic disease. Hearing loss may be a symptom of hereditary nephritis. Chronic sinusitis or nasal ulcers may be indicative of Wegener’s granulomatosis, and oral ulcers may suggest connective tissue disease. Retinopathy may result from either malignant hypertension or connective disease. Abnormal kidney function may also be evidence of systolic dysfunction, cardiac dysfunction, pulmonary hypertension, or liver disease. Treatment for nephritis may include special diets, antibiotics, surgery, dialysis, or organ transplant. Specific diseases Kidney diseases generally fall into three categories: hereditary, congenital, and acquired. Hereditary kidney diseases may be transmitted by both males and females, but clinical symptoms may not develop until adolescence or early adulthood. Throughout the world, the most common hereditary kidney condition disease is polycystic kidney disease in which cysts develop in the kidney. This largely asymptomatic disease occurs in all races. The progression of the disease is highly variable, but it often leads to advanced kidney failure. In half of all cases, more aggressive treatments are unnecessary until after the age of 70. The delay is more common in patients with normal blood pressure. Other inherited kidney disorders include hereditary nephritis, primary hyperoxaluria, and cystinuria. Genetics does not play a factor in congenital kidney diseases, which are caused by malformations of the genitourinary tract that occur during fetal development. Obstructions caused by malformations may result in kidney infections or chronic kidney failure. Most kidney diseases are acquired and can occur at any age. Nephritis, an inflammation of the kidney, is an umbrella term for kidney diseases. The most common type of nephritis is glomerulonephritis, which may be caused by a variety of factors. It is often diagnosed through urinalysis. The condition
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is frequently associated with low albumen levels, elevated blood cholesterol, and severe fluid retention. The disorder can be primary, or it can be the result of other illnesses, including chronic kidney disease. Prolonged use of large amounts of pain compounds have been linked to nephritis, as have a number of toxins, pesticide exposure, and heroin use. Consumption patterns around the world may be responsible for diverse patterns of compound-related nephritis. The southeastern section of the United States, Belgium, Australia, Scotland, and Switzerland all have higher than normal incidences. In childhood, nephritis may manifest as swelling around the eyes, stomach, and legs, infrequent urination, weight gain, fatigue, pain in the arms or legs, irritability, loss of appetite, and paleness. Generally appearing between the ages of 1-1/2 to 5, the cause of this disorder is not known. Medications are generally successful in treating the disease, and children tend to outgrow it by the late teens or early adulthood. It is estimated that one in ten individuals will develop kidney stones. They are more common in males than females and tend to occur between the ages of 20 and 40. Evidence of kidney stones has been traced back thousands of years. The tendency for stone formation may be inherited. Stones may also be a result of infection, malformations of the kidney, pregnancy, or metabolic disorders. They may also occur in isolation. In textbook cases, kidney stones lead to frequent urination, burning and difficult urination, and excruciating pain in the small of the back. Pain may also be present in the sides and abdomen, and the patient may experience nausea and vomiting. Fever and chills indicate the presence of infections. Pain medication may be used until stones have passed or until further treatment takes place. Immediate surgery is indicated when stones block the kidney. In the past, surgery to remove kidney stones was a major operation. The introduction of extracorporeal shock wave lithotripsy (ESWL), the nephroscope, and the ureteroscope permit physicians to shatter or remove stones without surgery. In around a third of kidney stone analyses, lab tests are able to pinpoint the cause of the stone formation. Most stones are made up of a variety of chemicals, with the most common being calcium with oxalate or phosphate. Uric acid and cystine stones are less common. Post-op treatment may entail changes in diet and increased water consumption.
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Kidney cancer may develop at any age. Wilms’ tumor, for instance, is a kind of children’s cancer in which cancer cells attack certain parts of the kidney. It is most common in individuals under the age of 15. Complete recovery is possible if the cancer has been caught early and if it has not spread to other parts of the body. When determining severity and treatment for all cancers of the kidney, physicians classify malignancies according to five stages. Surgeons are generally able to remove all of the cancer in Stage I, where cancer is concentrated in the kidney, and Stage II, where the malignancy has not spread beyond the kidney and surrounding areas. Cancer of the last three stages calls for more aggressive treatment because surgeons may not be able to remove cancers that have spread to other parts of the body (Stage III), the large organs (Stage IV), or to both kidneys (Stage V). Treatment for latter-state cancers includes chemotherapy and radiation in addition to surgery. Pregnancy Pregnant women are particularly vulnerable to kidney abnormalities because of increased demands on the kidneys. Before 1980, women with pre-existing renal disease were discouraged from becoming pregnancy. Highly related to kidney disease, hypertension affects 10 percent of all pregnant women. It is particularly prevalent in young women experiencing a first pregnancy and in older women who have undergone several pregnancies. Pregnancy-related high blood pressure may be indicative of preeclampsia (toxemia), a potentially fatal condition if left untreated; preeclampsia superimposed on chronic hypertension or renal disease; chronic essential hypertension, or gestational hypertension. The latter type generally disappears after giving birth. Pregnant women are no more susceptible to urinary tract infections than other women. If infections do occur, however, they may entail more serious consequences, especially in women who have either diabetes or sickle cell anemia or who come from lower socioeconomic backgrounds. Only about half of all urinary tract infections that occur during pregnancy are symptomatic. The possibility of potential complications is the reason that physicians monitor the health of pregnant women carefully, particularly during the final month. In highrisk pregnancies and in patients with a prior history of kidney infections and diseases, closer monitoring
is required. Left untreated, urinary tract infections may lead to pyelonephritis, a condition in which the kidneys are permanently scarred and damaged, or to the development of bacteremia, septic shock, and decreased renal function. The presence of bacteriuria in mothers is linked to an increased risk of mid-trimester spontaneous abortions (miscarriages). If infection occurs within two weeks of delivery, the risk of perinatal (within the first month of life) mortality doubles. Acute pyelonephritis during pregnancy has also been associated with higher than normal incidences of intrauterine growth retardation and mental retardation of the fetus. In some cases, urinary tract infections are not specifically related to pregnancy but may be indicative of kidney disease, acceleration of pre-existing renal disease, or systemic disorders. SEE ALSO: Abortion; Birth Defects; Cancer (General); Dia-
betes; Dialysis; Genetic Disorders; Glomerular Diseases; High Blood Pressure; Hormones; Liver Transplantation; National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK); Polycystic KidneyDisease; Pregnancy; Sickle Cell Anemia; Urinary Tract Infections. BIBLIOGRAPHY. Barry M. Brenner, ed., Brenner and Rector’s
The Kidney, v. I (W.B. Saunders, 2000); Barry M. Brenner, ed., Brenner and Rector’s The Kidney, v. II (W.B. Saunders, 2000); Frederick Dische, Renal Pathology (Oxford University Press, 1995); Scott Echols, ed., Renal Disease (Saunders, 2006); John Hopkins University, “Online Mendelian Inheritance of Man,” http://www.ncbi.nlm.nih.gov/sites/ entrez (cited July 2007); Anil K. Mandal and J. Charles Jennette, eds., Diagnosis and Management of Renal Disease and Hypertension (Carolina Academic Press, 1994); Shaul G.Massry and Richard J. Glassock, eds., Massry and Glassock’s Textbook of Nephrology (Lippincott, 2001); National Kidney Foundation, http://www.kidney.org/ (cited July 2007); Linda M. Ross, ed., Kidney and Urinary Tract Diseases and Disorders Sourcebook (Omnigraphics, 1997); Robert W. Schrier, ed., Diseases of the Kidney and Urinary Tract, v. I (Lippincott Williams and Wilkins, 2001); Robert W. Schrier, ed., Diseases of the Kidney and Urinary Tract, v. II (Lippincott Williams and Wilkins, 2001); Robert W. Schrier, ed., Diseases of the Kidney and Urinary Tract, v. III (Lippincott Williams and Wilkins, 2001). Elizabeth R. Purdy, Ph.D. Independent Scholar
Kidney Failure and Dialysis Kidney, or renal failure is the loss of the ability of the kidney to eliminate waste and excess material from the bloodstream and to recycle important nutrients back into the blood. Without correctly functioning kidneys, excess fluid and waste products like urea and excess potassium can accumulate to dangerous levels in the body. This process can be acute (suddenly occurring) or chronic (developing overtime). Both types cause damage to the kidneys but are associated with different medical conditions and also have very different disease courses and outcomes. A common treatment for kidney failure is dialysis during which the blood is filtered mechanically to compensate for the nonfunctioning kidneys. In order to fully grasp the concept of kidney failure it is important to understand what the kidneys do. The kidneys are two bean-shaped organs located in the back of the upper abdomen, one on each side of the spine. They are part of the urinary system. When we eat, our bodies digest proteins and separate them into different substances that are distributed into the bloodstream. The jobs of the kidney are to sort waste materials that cannot be used, or are harmful, out of the bloodstream in order to eliminate them from the body as urine and also to keep substances that are essential for bodily functions, such as vitamins, minerals and electrolytes, in the bloodstream. The kidneys are like a water filter because they both catch and remove pollutants. When a water filter doesn’t work, pollutants, or waste, can remain in the water and can cause sickness when consumed. In the same way, when the kidneys don’t work, waste material remains in the bloodstream and can harm the body while electrolytes and other useful products are lost in the urine. The kidneys are also responsible for making certain hormones that keep bones healthy and maintain blood counts. Acute and Chronic Renal Failure Acute renal failure describes the condition when kidney functions deteriorate rapidly—as quickly as several hours or days. The causes of acute renal failure can be categorized into pre-renal, renal and post-renal depending on where the problem in the system lies. Prerenal causes are the most common and are generally caused by problems that interfere with blood supply
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to the kidney, decreasing the amount of oxygen and nutrients needed to work properly. Some examples are low blood pressure from bleeding or dehydration and reduced heart function due to a heart attack or congestive heart failure. Renal causes are those that directly damage kidney structures such as infections of small blood vessels, blood clots, and sudden reactions to medications or toxins that disturb filtration. Post-renal causes are due to interference to parts of the urinary system that take the urine formed in the kidneys and actually eliminate it from the body like obstruction of the bladder from blood clots, stones, or tumors. Essentially, this is much like a clog in a sink drain. If the faucet is running and nothing can get past the clog, the pressure in the drain will build up behind it and eventually flood the sink. Similarly, when the urinary system gets backed up, the kidneys cannot compensate for the extra fluid and are damaged. Many cases of acute renal failure occur in people who are already hospitalized for other medical conditions. Because of this, it is very important to recognize symptoms such as sudden swelling in hands or feet, decreased urine production, confusion, and abdominal pain. Once acute renal failure is suspected, it is important to confirm the diagnosis with laboratory tests that measure concentrations of certain substances in the urine and blood to tell you whether the kidneys are working properly. Unlike acute renal failure, which is transient (lasts a short time) and causes reversible damage, chronic renal failure persists for a long time and causes irreversible changes to kidney structure and function. Chronic renal failure is the result of continuous insult to the kidney occurring slowly over many years. During this time, the kidney structure is damaged but because the change is gradual, symptoms of the early stages go unnoticed and the diagnosis of chronic kidney failure is not usually made until at least seventy-five percent of kidney function is lost. Chronic kidney failure can be caused by many diseases but the two most common causes are diabetes and hypertension, both of which are common in many world populations. Diabetes is a disease with elevated levels of sugar in the blood that forces the kidneys to work much harder during the filtering process. In a similar manner, hypertension is a disease where elevated blood pressure and subsequent damage to blood vessels overwork the kidneys. As the
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kidneys progressively weaken, the filtering process suffers and the kidneys begin leaking small useful proteins into the urine and keep large waste products circulating in the blood. As this process continues, the kidneys eventually lose the ability to produce a hormone called erythropoietin, which, under normal conditions, maintains the blood count. Decrease in the integrity of filtration in chronic renal failure also diminishes the blood calcium level leading to bone weakness and increase fracture risk. Treatment of Renal Failure There are many treatments available for renal failure. In people suffering from acute renal failure, the best therapy is to treat the underlying cause. In a majority of cases, once the etiologic cause is normalized, normal kidney function resumes. The most commonly used therapy is dialysis, which is a method of exogenous replacement of renal function. It is an indicated therapy for both transient and permanent loss of kidney function. It is important to understand that dialysis is simply a supportive measure and does not treat the actual kidney disease. There are two types of dialysis used for renal failure, hemodialysis and peritoneal dialysis. Hemodialysis works by adjusting the composition of fluid inside a machine to simulate a healthy kidney so that when blood passes through it, waste products such as urea, excess potassium and excess fluid are filtered out and only a normal volume of healthy blood is returned to the body. It usually takes two to four hours and the frequency of sessions depends on the severity of disease, it is usually done twice or three times a week. Peritoneal dialysis works by filling the abdomen with a cleansing solution that attracts wastes such as chemicals and excess fluid through the peritoneal cavity. After a set amount of time, the solution is drained from the abdomen and it carries back the waste products out as well. This cycle of filling and draining is done multiple times daily. If these therapies are unsuccessful, the last treatment option is a kidney transplant. SEE ALSO: Dialysis; Kidney Diseases (General); Nephrology. BIBLIOGRAPHY. Abul Abbas, Ramzi Cotran, Nelson Faus-
to, Vinay Kumar and Stanley Robbins, Robbins and Cotran: Pathologic Basis of Disease, 7th ed. (Elsevier Saunders, 1999); Malay Agrawal, M.D. and Richard Swartz, M.D.,
“Acute Renal Failure.” American Family Physician (v. 61/7, 2000); E. Balk, et al., “National Kidney Foundation Practice Guidelines of Chronic Kendye Disease: Evaluation, Classification, and Stratification.” Annals of Internal Medicine (v. 139/2, 2003); E. Needham, “Management of Acute Renal Failure.” American Family Physician (v. 72/9, 2005); Arthur Schneider and Phillip Szanto, Pathology BRS 2nd ed. (Lippincott, Williams & Wilkins, 2001). Angela Garner, M.D. University of Missouri–Kansas City
Kidney Stones Although kidney stones were a part of urinary tract problems even several thousand years ago, their prevalence in the United States has risen recently. Currently, there are no known definite causes of kidney stones. They are usually made up of products in our diets, but people who share the same diet do not always share kidney stone occurrence. Affliction with kidney stones may also run in families, although a genetic cause has not been identified. The pain and inconvenience due to kidney stones makes a significant impact on healthcare spending and doctor visits. People with kidney stones seek the attention of an urologist. Kidney stones may lodge in the urinary tract of a patient, outside of the kidney, but are named for having originated in the kidney. While the kidneys filter blood plasma and produce urine, crystals of solute sometimes separate from the urine. Normally, they are passed unrecognized in the urine stream and do not cause pain or discomfort. The urine chemistry also contains factors that inhibit larger crystal formation. In some people, the crystals, nonetheless, combine to form larger crystals that collect on the linings of the kidney ducts and tubes. Large crystals that cause pain and discomfort are called kidney stones. The stones are classified by their components. The most common type contains deposits including those of calcium and oxalate. Other stones are caused by urinary tract infections, uric acid buildup, or other factors. Often, the stones are passed from the kidney and become lodged in the urinary tract; thus, kidney stones can also be classified by their location in the urinary tract.
Kidney Transplantation
A person who has a kidney stone does not usually need surgery. Most kidney stones can be passed in the urinary system, aided with plenty of drinking water. Sometimes, the stone can be stored and brought in for examination by a doctor to determine the underlying cause. If a person has repetitive cases of the same type of kidney stones, his or her physician may be able to recommend some lifestyle changes such as diet modification and increased water intake. Stones that are larger than about three millimeters may be difficult to pass in the urine. If a kidney stone grows to larger than six millimeters, simply passing it in the urine is not usually an option. Some nonsurgical alternatives include disrupting the stones with ultrasonic or mechanical energy, administered through the skin of the abdomen. If these methods are unsuccessful, a patient may turn to a surgeon to remove a larger stone. Although people of all races, eating all diets develop kidney stones, in the United States, Caucasian Americans typically have more stone problems than African Americans. SEE ALSO: Kidney Diseases (General); Urinary Tract Infec-
tions; Urological Surgeon; Urologist.
BIBLIOGRAPHY. ICON Health Publications, The Official
Patient’s Sourcebook on Kidney Stones: A Revised and Updated Directory for the Internet Age (ICON Health Publications, 2005); John S. Rodman, et al., No More Kidney Stones: The Experts Tell You All You Need to Know about Prevention and Treatment (Wiley, 2007); Gail Savitz, The Kidney Stones Handbook: A Patient’s Guide to Hope, Cure, and Prevention (Four Geez Press, 1999).
Claudia Winograd University of Illinois
Kidney Transplantation Kidney transplantation is a surgical procedure that implants a healthy kidney into a patient with renal failure. An early symptom of kidney failure is a low glomerular filtration rate. Common causes for kidney failure are diabetes, uncontrollable hypertension, and glomerulonephritis. The first kidney transplantations were done on identical twins in Boston and Paris in 1954. A ma-
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jor barrier to transplantation is the process of rejection in which the recipient’s immune system recognizes the graft being foreign and attacks it. The antigens responsible for this reaction are the HLA system. The HLA genes are highly polymorphic and any two individuals (except identical twins) will express different HLA proteins. Three kidney rejection reactions are hyperacute, acute, and chronic. Hyperacute rejection occurs within minutes or hours of transplantation and can be recognized by the surgeon just after the graft vasculature is anastomosed to the recipient’s. This process occurs when preformed antidonor antibodies are present in the circulation of the recipient. An acute rejection occurs within days of transplantation in an untreated recipient or may occur months or years later when the immunosuppression has ended. Chronic rejection presents in patients with a sudden rise in serum creatine over a period of four to six months. Mechanisms for increasing graft survival are to match more of the HLA genes between the recipient and the donor. Also, patients are given immunosuppressive drugs to prevent attack of the transplanted organ by the transplant recipient’s immune system. Common drugs are cyclosporine, azathioprine, steroids, rapamycin, and mycophenolate mofetil. A common side effect of immunosuppressive treatment is for the recipient to be more susceptible to opportunistic infections most likely by fungal or viral organisms. Also these patients are at a higher risk for cancers that are caused by viruses. Current research to overcome this obstacle of immunosuppression is looking at inducing donor-specific tolerance in host T cells. The United Network for Organ Sharing (UNOS) is a private, nonprofit organization that matches available organ donors with waiting transplant recipients through the national Organ Procurement and Transplantation Network (OPTN). Organ procurement is dependent on recipient time on waiting list, severity of disease, ABO blood type, and body size. The common procedure for removal of a kidney from a living donor is a less invasive laparoscopic surgery. In the recipient, the diseased kidney is usually not removed. Instead, the donor kidney is placed inferior to the diseased kidney and the blood and urinary flows are redirected to meet the new kidney. The graft survival rate for kidneys from living donors is approximately 95 percent at one year and 76 percent at five years, whereas
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the graft survival rate for kidneys from cadaveric donors is 89 percent at one year and 61 percent at five years. SEE ALSO: Kidney Diseases (General); Kidney Failure and
Dialysis; Kidney Stones; Organ Transplantation.
BIBLIOGRAPHY. American Society of Transplantations,
“Getting a New Kidney: Facts about a Kidney Transplant,” www.a-s-t.org (cited January 2006); Vinay Kumar, et al., Pathologic Basis of Disease (Elsevier Saunders, 2005); Medline Plus, “Kidney Transplant,” www.nlm.nih.gov (cited January 2006); Richard Sinert, “Renal Transplants,” www. emedicine.com(cited January 2006). Pavan Bhatraju Independent Scholar
Kiribati The 33 atolls and reef islands of Kiribati stretch 4,000 kilometers from east to west and 2,000 kilometers from north to south. Kiribati is made up of three island groups, the Gilbert Islands, the Line Island, and the Phoenix Islands, but the total landmass is a mere 811 square kilometers, or about four times the size of Washington, D.C. The country straddles both the Equator and the International Date Line, although in 1995, the government unilaterally “moved” the line to assure that all the islands fell under the same day. It was a change that allowed Kiribati to tout itself as the first inhabited place on Earth to see the sun rise on the millennium in 2000. Because its written language lacks a letter “s,” the name is pronounced “Kiribas,” and residents are known as I-Kiribati. The population is 105,400 and is growing at 2.24 percent annually. Most I-Kiribati live in villages of 50 to 3,000 residents. The capital island of Tarawa is the most heavily populated, with more than 29,000, and many demographers believe this is an unsustainable population size. Kiribati’s economy is driven by tourism, fishing exports, and remittances from residents working abroad. The underemployment rate is 70 percent, with an official unemployment rate of two percent. Life expectancy is low for the Pacific region, probably driven down by high child mortality rates. Life span is now 59 years for males and 65 years for females. Infant
mortality (ages 0 to 1) and child mortality (ages 1 to 5) are each 65 death per 1,000 population. Most children die from respiratory infections or diarrheal illnesses. Maternal mortality is 103 deaths per 100,000 live births. Kiribati is largely free of communicable diseases such as measles, polio, and diphtheria. In 2004, there were 51 new cases of hepatitis and 64 cases of leprosy. Past years have seen sporadic outbreaks of dengue fever and cholera. The government is working to improve drinking water and sanitation, with 65 percent of the population currently able to access potable water and 40 percent using adequate sanitation. Acute respiratory diseases and gastrointestinal diseases are the greatest sources of morbidity on Kiribati. “Lifestyle” diseases such as diabetes and hypertension are becoming increasingly common. There were 4,000 diabetes patients in 2000, and the figure is expected to grow to 7,000 by 2030. Accidents and suicides are frequent sources of both morbidity and mortality among I-Kiribati, especially the young. HIV/AIDS has not emerged as a major issue in Kiribati, with only 46 cases reported by the end of 2004. However, the country has all the elements necessary for a serious outbreak: widespread poverty, high unemployment, drug use, and a growing sex industry. Attempts to institute education programs have been hampered by a generally held belief that AIDS is not a problem in the Pacific region. The geography of Kiribati presents challenges for both the healthcare and social service systems. The population is widely dispersed, and those living on outlying islands are not always able to access (or afford) an airlift or a boat to the nearest medical facilities. The central hospital is located on Tarawa, with an additional 94 district hospitals spread across the more populous islands. The government is working to increase access in remote locations. In 2004, there were 20 doctors, three dentists, 238 nurses, and 32 midwives working in Kiribati. SEE ALSO: Healthcare, Asia and Oceania. BIBLIOGRAPHY. “Kiribati,” World Health Organization,
http://www.who.int/countries/kir/en/ (cited July 2007); Tony Whincup, Kiribati (Kiribati Government, 1981).
Heather K. Michon Independent Scholar
Kirklin, John W. (1917–2004) John W. Kirklin was an American cardiovascular surgeon who refined the heart-lung machine first devised by John H. Gibbon and applied it to open-heart surgery. Kirklin not only used the improved heart-lung machine in operations but also in the study of congenital heart problems. Kirklin’s book, Cardiac Surgery, quickly became a standard textbook in the field. Kirklin was born on August 5, 1917, in Muncie, Indiana. When he was 8 years old, his family moved to Rochester, Minnesota, where his father had been offered the position of Director of Radiology at the Mayo Clinic. He obtained his undergraduate degree at the University of Minnesota in 1938 and went on to Harvard Medical School from where he graduated magna cum laude in 1942. Kirklin completed his internship at the University of Pennsylvania Hospital in Philadelphia and was then recruited by the Mayo Clinic as a fellow in surgery. From 1944 to 1946, he joined the Army where he served as a neurosurgeon. After the war, he returned to the Mayo Clinic to complete his surgical residency, which also included six months at the Boston Children’s Hospital. After his residency, Kirklin stayed on the faculty at Mayo and, during the 1950s, he brought a series of improvements to the Gibbon heart-lung machine. These modifications allowed the machine to be used in open-heart surgery. Kirklin became Professor of Surgery in 1960 and four years later he was appointed Chairman of the Department of Surgery at Mayo. In September 1966, Kirklin was hired by the University of Alabama at Birmingham (UAB) to chair the Department of Surgery. Kirklin launched UAB’s Surgeon Assistant (SA) Training Program in 1967. The program soon became one of the most prestigious and respected training schemes worldwide. Kirklin continued to act as chairman of the Department of Surgery until 1982. He practiced cardiovascular surgery until 1989. After his retirement from surgery, Kirklin continued to work as editor of The Journal of Thoracic and Cardiovascular Surgery. Throughout his career, Kirklin produced more than 700 articles and books, including the landmark volume Cardiac Surgery: Morphology, Diagnostic Criteria, Natural History, Techniques, Results, and Indications (1956). This volume has been constantly updated and remains an important textbook for students of cardiac surgery.
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For his pioneering contributions to the world of surgery, Kirklin received many awards, including the American Heart Association Research Achievement Award, the Rudolph Matas Award in vascular surgery, the Rene Leriche Prize of the International Society of Surgery, and the American Surgical Association medallion for scientific achievement. Kirklin died on April 21, 2004, from complications from a head injury. SEE ALSO: Cardiology; Heart Bypass Surgery. BIBLIOGRAPHY. “John Webster Kirklin” Web site of the
Physician Assistant History Center, http://www.pahx.org/ kriklinBio.htm (cited July 2007).
Luca Prono Independent Scholar
Klinefelter’s Syndrome Klinefelter’s syndrome (KS), named after Dr. Harry Klinefelter who first described the condition in 1942, is a disorder present in males who have at least two X chromosomes and one Y chromosome leading to 47 chromosomes as opposed to the normal XY constellation. It is found in approximately one out of every 500 to 1,000 newborn males. The incidence of KS in the general population is 0.1 to 0.2 percent, among infertile patients it is three percent, and in patients with aspermia (complete lack of semen), it is approximately 11 percent. Women over age 35 have a slightly increased chance of having a child with KS. There are no other known risk factors for this disorder. In most cases, the problem develops during fetal life and is not inherited from one or both parents. KS is the most frequent form of male hypogonadism, and thus patients present with decreased levels of androgens. Patients present with various other symptoms including gonadotropins (e.g., luteinizing hormone, follicle stimulating hormone), fibrosis and hyalinization of the seminiferous tubules, small testes, gynecomastia (breasts enlargement in males), sparse facial hair, diminished sexual activity, increased truncal fat, and decreased muscle mass. KS patients are recognized in the second decade of life by their tall stature.
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KS has several variants that may present with different symptoms in addition to the typical symptoms mentioned. Patients of the 48 XXYY variant may present with mental retardation and eunuchoid habitus (undeveloped sexual organs). Patients of the 49 XXXY variant may have severe mental retardation, distinct facial features such as protruding lips and epicanthal folds (skin fold on upper eyelid); clinodactyly (curvature of the little finger toward the ring finger), and radioulnar synostosis (osseous union of the radius and ulna). Patients with 49 XXXYY also have severe mental retardation and aggressive behavior. An extra X in the chromosome constellation appears to be associated with physical and cognitive development aberrations; some reports suggest that there is a decrease in intelligence quotient (IQ) test results, although other studies have stated that it is normal. Patients generally have problems with language and often have learning disabilities. Other complications of KS include increased risk of malignancy—breast cancer; cardiovascular system disorders such as mitral valve prolapse; osteoporosis and autoimmune disorders such as systemic lupus erythematosus and autoimmune hepatitis, and taurodontism (enlarged pulp and thinning of teeth). KS is also associated with an increased prevalence of diabetes mellitus and is reported to be associated with bipolar disorder and attention deficient hypersensitivity disorder (ADHD). Treatment options include testosterone replacement for correction of the androgen deficiency. Androgen replacement therapy generally begins at puberty, around age 12; as the patient gets older, the dosage is increased to maintain age-appropriate serum concentrations of testosterone, estradiol, FSH, and LH. Testosterone is needed to prevent osteoporosis and loss of muscle mass and strength. The hormones improve bone density making fractures less likely and stimulate development of a more masculine appearance. Boys with KS usually benefit from speech and language therapy and eventually can do well in school. The prognosis of the disorder is good, and most patients are able to live a normal life. SEE ALSO: Endocrinology; Male Genital Disorders. BIBLIOGRAPHY. P. J. Simm and M. R. Zacharin, “The Psy-
chosocial Impact of Klinefelter Syndrome—A 10 Year
Review,” Journal of Paediatric Endocrinology Metabolism (v.19/4, 2006). Farhana Akter King’s College, London
Knee Injuries and Disorders The knee is a major weight-bearing synovial-hinged– type joint located below the femur (thigh bone) and above the tibia (shin bone) and fibula in the leg. It is crucial to understand the anatomy of the knee including the major muscles, ligaments, cartilages, bones, nerves, and blood vessels that surround and encapsulate the knee joint. Basic knowledge of the anatomy of the knee helps in understanding why knee injuries occur. Basic Anatomy of the Knee The anterior aspect of the knee includes the kneecap, otherwise known as the patella. It is a sesamoid bone that is imbedded in an extensor tendon of the knee. The patella is triangular and is located in a groove formed by the femur; this protects the knee joint. In some instances, the patella may dislocate out of the groove from weakness of the muscles that form the extensor tendon of the knee. These muscles are located toward the interior aspect of the thigh, and are called the quadriceps. Nerve innervation is supplied to the quadriceps by the femoral nerve, which helps to straighten or extend the knee joint. The extensor tendon of the knee comes from the quadriceps and then attaches below the knee to the shin, or tibia. Attachment of the tendon occurs on the area of the tibia known as the tibialtuberosity. The posterior aspect of the knee joint is referred to as the popliteal fossa. It is a diamond-shaped area that contains the tibial nerve, common peroneal nerve, and the popliteal blood vessels. These nerves and blood vessels supply the knee as well as the lower leg and foot. The posterior muscles of the thigh, the hamstrings, which bends or flexes the knee joint, forms this fossa. The hamstrings also prevent the tibia from sliding too far forward when the knee joint is in motion. Innervation to the hamstrings is supplied by the sciatic nerve.
The knee joint itself consists of an articulation between the femur, tibia, and patella. Between the femur and tibia is cartilage called meniscus, which acts as a cushion. The menisci also produce an increase in surface area contact between the femur and tibia. There are two menisci in the knee joint: the medial and the lateral. The medial is on the inside of the knee joint, and the lateral is on the outside. Both the medial and lateral meniscus attach to the medial portion of the tibia. The medial meniscus does not move while the lateral meniscus does. Also, between the knee joint are two support ligaments called the anterior and posterior cruciate ligaments. These ligaments prevent excessive forward and backward motion of the knee joint. They are named for where they originate on the tibia. The anterior cruciate ligament starts on the anterior aspect of the tibia and attaches to the posterior aspect of the femur. The posterior cruciate ligament
Basic knowledge of the anatomy of the knee helps in understanding why knee injuries occur and how to prevent them.
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originates on the posterior portion of the tibia and attaches to the anterior portion of the femur. These important ligaments maintain stability in the knee joint, and come into play when the femur tries to override the tibia. There are two other ligaments in the knee: the medial collateral ligament and the lateral collateral ligament. These ligaments add to the stability and helps prevent tilting of the knee joint. The medial collateral ligament is a flat, ribbon-like tendon that connects the tibia to the femur. It also attaches to the medial meniscus and knee joint capsule, making it more susceptible to injury. If one of these structures becomes injured, the medial collateral ligament will most likely be as well. The lateral collateral ligament is a thin, cord-like ligament between the fibula and the femur. The fibula is the bone to the lateral side of the tibia and is not a weight-bearing bone. Unlike the medial collateral ligament, the lateral collateral ligament does not attach to the meniscus or knee joint capsule. However, this ligament is noteworthy due to the attachment to the fibula. Damage to the lateral aspect of the knee can also cause damage to the common peroneal nerve. The synovial sac is a fluid-filled sac that encapsulates the menisci but not the cruciate ligaments. The medial meniscus, however, does attach to the outside portion of the sac. Its purpose is to help lubricate the knee joint. Along with the synovial sac, there are other fluid-filled sacks called bursae. These act as a lubricant around the knee joint to decrease friction and improve mobility. There is one bursa above the patella called the prepatellar bursa, and three below the patella called pes anserinus. Bursae are susceptible to injury due to their role in the function of the knee joint. Knee Biomechanics The knee mainly has two movements: extension (straightening) and flexion (bending). When the knee is in full extension, the foot is firmly on the ground and the leg straight. While the knee joint is fully extended, the femur rotates slightly over the tibia. This causes tension in the collateral ligaments and produces a compact configuration of the knee, also referred to as locked knee. The compact configuration allows us to stand for long periods of time without falling. The extension movement is produced by the
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quadriceps receiving the command to contract from the femoral nerve. For flexion to occur, extension must be undone by discontinuing contraction of the quadriceps. This allows the femur to rotate back to normal position, thus taking tension off the collateral ligaments. Then the hamstrings innervated by the sciatic nerve contract, thus moving the knee joint through the flexion motion. Typically the normal range of motion in terms of flexion is up to 120 degrees. This basic knowledge of the functional anatomy and biomechanics of the knee joint can help in understanding trauma, overuse, and disease processes of the knee. It also helps in the ability to evaluate and manage any problems that may occur. Some common trauma injuries as well as overuse injuries follow. Meniscus Injury Injuries to the menisci are very common in athletes playing sports that require sharp turns or cuts, such as football or soccer. When a meniscus injury occurs, patients might have mild swelling, pain with flexion or extension, a sensation of the knee locking or catching, or pain with a physician moving the knee joint through its normal motion. Often, X-rays show nothing. Therefore, magnetic resonance imaging (MRI) is the best test because it shows what has occurred to the meniscus. Surgery is not needed 50 to 75 percent of the time; normal treatment is protection of the joint, rest, ice, compression wrapping, elevation of the joint, medications, and manipulation (PRICEMM). Crutches can be beneficial, allowing the patient to keep weight off the knee joint, helping to avoid the joint from twisting. In nonsurgical meniscus tears, it is advised to return gradually to normal activity after 6 to 12 weeks. If surgery is needed, the return can take between 6 to 12 months. Patellar Dislocation Patellar dislocation can occur from twisting or from a direct blow to the medial side of the patella. Usually the dislocation occurs to the lateral side of the knee. When the patella moves out of the groove which it tracts, pain, knee locking, swelling, bruising, and increased pain with 10 degrees of flexion can occur. Often, the patella can be reduced back into place as the knee is extended. It is advisable to see a doctor specializing in bones with a first dislocation. Other treat-
ments that may be used include PRICEMM, strengthening of quadriceps, and immobilization. Medial Collateral Ligament (MCL) Injury MCL injuries occur frequently when stress is applied to the lateral aspect of the knee, by either a direct blow or rotational stress. These are very common among athletes who must cut sharply, and occur frequently in female alpine skiers. These injuries are graded depending on the level of disruption that occurs to the ligament. Grade I involves stretching of the ligament, grade II is a partial tear, and grade III is a complete tear of the ligament. When MCL injuries occur, pain will be present with flexion and extension, swelling usually occurs after 24 hours, instability in the knee, and pain when the joint is moved through normal motion. MRI is the best test to demonstrate the ligament disruption, because X-rays will not show any disruption. Treatment consists of using crutches, resting the joint, ice, compression wraps, and elevation. Anti-inflammatory drugs may also be used to help with pain and inflammation. For a grade III injury, immobilization of the knee to 30 degrees from full extension is recommended for two weeks. Then, an MCL brace for protection is used for six weeks of rehabilitation. Surgery is a last resort. Often, one can gradually return back to normal activities in three to six weeks. Osgood-Schlatter Disease Osgood-Schlatter disease is the most common cause of knee pain in 8- to 15-year-olds. It is caused by inflammation of the growth center of the tibia where the patellar tendon attaches, also known as the apophysis. The inflammation and patellar tendon contraction cause microfractures to occur at the apophysis. These cause pain, especially with kneeling, jumping, and knee extension. An X-ray of the tibia may demonstrate the microfractures or irregular bone development. Treatment consists of icing the shin when pain is present for 20 minutes and rest from high-impact activities. Return to these activities can be resumed gradually as tolerated. Prepatellar Bursitis Prepatellar bursitis can be caused by trauma or kneeling on the ground. Sometimes, infection can occur in
the bursa. When infection is present, the skin around the bursa will turn red and warm. This causes inflammation of the area; fever may accompany these symptoms. When bursitis occurs, the area can become painful, causing stiffness, pain with motion, and swelling. If an infection is suspected, the bursa can be drained and antibiotics can be helpful. Activities should be continued as tolerated. Osteoarthritis Osteoarthritis is a common problem that occurs with an increase in age. It affects the knee and other weightbearing joints. The cartilage within a joint begins to break down, causing the space between bones to narrow. The bone then begins to grow, causing changes within the joint. These changes can cause pain, stiffness, and instability. X-rays show that the space between the femur and tibia continue to narrow over time. Anti-inflammatory medications can be used to help with pain and inflammation. If obesity is a factor, weight loss may help symptoms. Joint replacement should be postponed as long as possible, but may be helpful if the function of the knee is no longer present or the pain is intolerable with current treatment. SEE ALSO: Arthritis; Bursitis; Sports Injuries. BIBLIOGRAPHY. Dennis Kasper, et al., Harrison’s Manual
of Medicine, 16th ed. (McGraw-Hill, 2005); James Puffer, 20 Common Problems in Sports Medicine (McGraw-Hill, 2002); Robert Sallis and Ferdy Massimino, Essentials of Sports Medicine (Mosby, 1997).
Ahmed Samad Kansas City University of Medicine and Biosciences George Kolo Kansas City University of Medicine and Biosciences Brett D. Dunbar Independent Scholar
Knockout Gene knockouts are genetically engineered animals in which a specific gene is disrupted so that the gene product is no longer produced. The absence of the
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gene often leads to some observable effects in terms of animal physiology, behavior, or other characteristics. Any abnormalities that result from knocking out a gene serve as valuable clues regarding the gene’s actual function. Usually, knockout technology is applied to mice, because mice are genetically quite similar to humans—and therefore, serve as good models of human disorders—and are relatively convenient to study. Knockout technology has many medical applications. For instance, researchers can disrupt a gene that is involved in a particular disease in order to examine the physiology surrounding that disease. Similarly, knockout mice are useful in testing prospective drugs for safety and efficacy. Medical Applications of Gene Knockouts An example of the usefulness of gene knockouts is in the study of neurological disorders. A deficiency of the neurotransmitter dopamine is involved in a number of neurological/psychiatric illnesses, including Parkinson’s disease and schizophrenia. To study these diseases, scientists have knocked out dopamine transporters and dopamine receptors. These knockout mice have provided insight into the role of dopamine and possible therapies for diseases that involve this neurotransmitter. In a similar manner, knockout mice have been created to serve as models of a variety of human diseases, ranging from cancer to metabolic diseases to behavioral disorders. In addition to serving as disease models, knockout mice are utilized for testing potential drugs. In some cases, the safety of a drug is examined by knocking out the gene targeted by the drug and determining the extent of the negative effect. Conversely, drugs are sometimes given to knockout mice to determine whether the abnormalities of these mice can be alleviated. Some genes are essential for normal embryonic development, and knockout of one of these genes results in death during gestation. It is difficult to study the functions of the gene in this case, because the defects are so severe. To overcome this problem, techniques have been developed for knocking out a gene only in a particular cell type or at a particular stage in development. Moreover, even if a gene can be studied in mice, this does not necessarily mean that its functions in humans and mice are exactly the same. Mice are useful models,
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but they are not identical to humans. As a result, therapies that are developed based on a mouse model of a disease may not be effective against the disease in humans. Consequently, knockouts are an excellent starting point for biomedical research, but discoveries must be followed up in human clinical trials. SEE ALSO: Genetics; Genetic Disorders; Genes and Gene
Therapy.
BIBLIOGRAPHY. Ernesto Bockamp, et al., “Of Mice and
Models: Improved Animal Models for Biomedical Research,” Physiological Genomics (v.11/3, 2002); Helen V. Firth, Judith G. Hall and Jane A Hurst. eds. Oxford Desk Reference Clinical Genetics (Oxford University Press, 2005);
Kevin Shenderov New York University
Korea, North This country, located in north-east Asia, is officially known as the Democratic People’s Republic of Korea. The whole of the Korean peninsula was annexed by Japan in 1910, and then occupied by them until 1945. After Japan’s defeat in World War II, the Soviet Union’s army took control of the northern part of the peninsula, and the leader of the Korean Communist Party, Kim Il Sung, became head of state. Five years later, in 1950 the Korean War broke out, and although an armistice was agreed to in 1953, no peace treaty has ever been signed, resulting in tensions along the border. Prior to 1945, the health care in the whole of the Korean peninsula was minimal except for the Japanese migrants and Korean elite who were treated in Japanese-run hospitals. Many people relied on herbal cures and some had access to hot springs which provided spa baths. After World War II, there were some improvements from 1945 until 1950, but during the Korean War, all of the cities in North Korea were destroyed in U.S. aerial bombing. From January 1953, with all health care services in the country being declared to be free to all, major efforts were made to rebuild the medical services. By the 1970s health services in North Korea were fairly good, run by the Academy of Medical Sciences, and were extolled
heavily in government publications, although they declined owing to budgetary shortages in the early 1990’s, and have undergone significant advances since then. In addition mention must be made of the famine of the early 1990’s that caused the deaths of hundreds of thousands of people, and put an enormous strain on the health services of the country. In the public literature of the North Korean government, great emphasis is made on the public health service, with a range of methods of treatment, hospitals in Pyongyang, the capital, and other cities, with a large number of health complexes being built around the country, and heavy use still made of hot and cold mineral spas. Officially there were 2,700 hospitals in the country in 1996, although undoubtedly this figure includes small health centers and clinics. There are 16 medical research institutes located in the country, most being in Pyongyang, all affiliated with the Academy of Medical Sciences. Most doctors are trained at the Pyongyang University of Medicine which teaches western medical techniques as well as utilizing elements from Chinese medicine and acupuncture, and Korean medicine, utilizing herbal cures and also elixirs some derived from antlers of deer. The Red Cross General Hospital of Korea appears to be the largest hospital in the country. It has an Ophthalmic section where doctors such as Dr. Kim Jong Ok, have treated up to 1,200 people suffering from blindness due to glaucoma. The most publicized hospital in the country is the Pyongyang Maternity Hospital, a large impressive medical facility in the eastern part of the capital. As well as being a hospital, it is also an obstetric research center and venue for training midwives. The building has a total floor space of 60,000 square meters, with over 2,000 rooms and was completed in March 1980. It has 1,000 beds for adults and 500 cots for babies. The hospital treats locals and also caters for the children of diplomats and other foreigners resident in Pyongyang. According to official literature, the hospital has a library of 100,000 books, a scientific photographic studio and an extensive quarantine system as well as a centralized oxygen supply system. Throughout the country there are many sanatoriums including those at Kwangmyong, Kyongsong, and Sijungho. Many are located near spas. With budgetary problems in the country, there has been increased use of traditional medicinal herbs, with the
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Rinsan Herb Cultivation Farm, in North Hwanghae Province grows hundreds of hectares of herbs; and there are similar centers in Kusong, North Pyongan Province, and Taehung in South Hamgyong Province. To improve health care, children and workers take part in compulsory exercise programs, and the rate of smoking among Korean men is high, resulting in a high prevalence of cancer, with excessive eating of the traditional Korean kimchi (pickled cabbage), as well as red ginseng, known to cause stomach cancer, with North Korea having the third highest rate of stomach cancer in the world, after Japan and South Korea. SEE ALSO: Cancer (General); Herbal Medicine; Korea,
South; Stomach Cancer.
Bibliography. Kim Chang Gil, “Woman Eye Doctor,”
DPRK No 379 (October 1987); Li Jup Yop, “Cultivation of Medicinal Herbs,” DPRK No 427 (November 1991); Public Health (Pyongyang: Foreign Languages Publishing House, 1983); Pyongyang Review (Pyongyang: Foreign Languages Publishing House, 1995). Justin Corfield Geelong Grammar School, Australia
Korea, South The Republic of Korea, as South Korea is officially known, was founded following World War II, and is located in north-east Asia. From 1910 until 1945 the whole of the Korean peninsula was a part of the Empire of Japan, having been effectively occupied by Japan since 1895. Following World War II, a pro-American government was established in South Korea under the leadership of Syngman Rhee. He survived the Korean War and remained president until 1960. Prior to 1945, the health care system in Korea was fairly rudimentary for most of the people in the country. The Korean Medical Association was founded on November 15, 1908 as the ‘Medical Affairs Research Society,” with 66 members. At that time only the elite and the Japanese had access to hospitals. Many of them still used elaborate herbal cures as well as bathing in spa baths in hot springs which were thought
It was not until 1991 that medical insurance was available to everybody in South Korea.
to provide cures for a variety of conditions including cancer. In addition some people still used the herbal prescriptions made in the 85-volume work produced in 1433 and known as the Hyangyak chipsongbang (“Great Collection of Korean Prescriptions”), and the Uibang yuch’wi (Great Collection of Medicines and Prescriptions), which was published in 1445, and ran to 365 volumes. The end of the war saw the new Syngman Rhee government oversee the foundation of the Chosun Medical Association on May 10, 1947, with it publishing its Journal of the Chosun Medical Association exactly a year later. On September 21, 1948 it was renamed the Korean Medical Association, and in July 1949 joined the World Medical Association. The Korean War, from 1950 until 1953, resulted in the devastation of much of the country, and there was a large rebuilding program from 1955. On October 6, 1966, the Council of Medical Societies was
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established, and on March 21, 1967, the first issue of the Korean Medical Association News was published. On April 29, 1970, the Korean Society for Medical Politics was founded in Seoul, with subsequent groups for Korean Japanese and Korean Americans founded in 1972 and 1974 respectively. In 1977 the Free and Subsidized Medical Aid Program was introduced for poor people in the country, and two years later the program was increased to cover civil servants, teachers in private schools and also all companies which employed 300 of more people. In 1981 it was extended to all companies that employed 100 or more people, and by 1984 covered everybody in companies with 16 or more people. It was not until 1991 that medical insurance was available to everybody in the country. The major problems that faced South Korea were respiratory diseases such as pneumonia, bronchitis and tuberculosis, as well as gastrointestinal illnesses. Gradually as the country industrialized and prospered, there were more cases of kidney and liver problems, and also cancer. Indeed South Korea now has the second highest rate of stomach cancer in the world, after Japan. This is thought to come from the excessive eating of kimchi, the traditional Korean pickled cabbage, as well as the eating of products that include red ginseng. In recent years there has been an increase in the number of cases of people suffering from HIV/AIDS and also Koreans abusing illegal drugs. There are also occasional cases of malaria along the border with North Korea. It is also claimed by many health professionals in South Korea that the rapid urbanization has led to an increase in the prevalence of mental illness. SEE ALSO: Korea, North; Herbal Medicine; Stomach
Cancer.
BIBLIOGRAPHY. The Korean Medical Association(KMA)
www.kma.org (cited August 2007); Abinder Gobindpuri, The Forgotten War: Medicine in Korea (B.Sc. Thesis, University of London, 2005); Gil Soo Han, “The Rise of Western Mand Revival of Traditional Medicine in Korea: A Brief History,” Korean Studies (v.21, 1997); Annette H. Son, “Modernization of medical care in Korea,” Social Science and Medicine (v.49/4, 1999). Justin Corfield Geelong Grammar School, Australia
Kübler-Ross, Elisabeth (1926–2004) Elisabeth Kübler-Ross was a Swiss-born American psychiatrist who elaborated the Kübler-Ross model, identifying five stages of coming to terms with dying. In her landmark study, On Death and Dying (1969), she broke down the process of dying in five phases: denial, anger, bargaining, depression, and acceptance. Her bestseller challenged Western cultural resistance to death and suggested ways with which terminally ill patients could be comforted. Thanks to her focus on terminally ill patients, Kübler-Ross helped to launch the hospice movement. The international fame that she had gained with On Death and Dying, however, was later disputed as her views became more eccentric and she began to explore out-of-body and neardeath experiences. Kübler-Ross was born in Zurich on July 8, 1926. She was the third of triplets and weighed only two pounds. Her childhood was marked by the abuses of her father who fought against her determination to become a doctor; he wanted her to be his secretary. After World War II, Kübler-Ross visited a Nazi concentration camp in Poland, an experience that deeply marked her. Contrary to her father’s wishes, KüblerRoss enrolled at the University of Zurich for a medical degree, which she obtained in 1957. The following year, she moved to New York with her husband to pursue her studies. She completed her psychiatric training first as an intern at Community Hospital, Glen Cove, Long Island, then as a fellow at Manhattan State Hospital, and finally as a resident at Montefiore Hospital in New York. She then moved to the University of Colorado, where she worked as an instructor in psychiatry from 1962 to 1965. At these institutions, Kübler-Ross observed that terminally ill patients were isolated and that doctors and nurses dealt with them in an impersonal manner that failed to comfort them. When she transferred to the University of Chicago in 1965 as Assistant Professor of Psychiatry, KüblerRoss was determined to change this situation. Over the objections of several of her colleagues she brought terminally ill patients to her classes and held popular seminars where the patients would speak about their feelings on death and dying. In 1969, Kübler-Ross
Kuwait
was catapulted to international fame: Life magazine ran a story on her seminars and her bestselling book On Death and Dying was first published. Although its five-stage model of dying has been repeatedly criticized and challenged, at the time On Death and Dying elucidated a powerful and influential argument for better treating the dying. Thus, although KüblerRoss did not actually found the hospice movement, she gave a fundamental contribution to its formation. She established healing centers in Virginia and California, and thanks to the success of her book, forced the media to give visibility to dying patients. Hospices quickly spread throughout the United States. At the peak of her fame, Kübler-Ross became increasingly fascinated by mysticism and began to talk about near-death experiences as well as her travel through space in her lectures and seminars. She was also badly exploited by Jay Barham, a conman who claimed to be an expert in religious rituals but was eventually investigated for sexual abuses. KüblerRoss’s husband, Emanuel Ross, divorced her, and the scientific community challenged her credibility. Some ventured as far as doubting her sanity. Her later years were also plagued by a series of strokes. She died on August 24, 2004. SEE ALSO: Death and Dying; Psychiatry. BIBLIOGRAPHY. Elisabeth Kübler-Ross Official Web Site,
http://www.elisabethkublerross.com (cited July 2007); Christopher Reed, “Elisabeth Kübler-Ross,” The Guardian (August 31, 2004). Luca Prono Independent Scholar
Kuwait This country, located at the north of the Persian Gulf, with borders with Iraq and Saudi Arabia, has been controlled by the al-Sabah family, with Sheikh Mubarak al-Lahab ibn Sabah Al Sabah (reigned 18961915), trying to establish a modern health care system by inviting Dr. Arthur Bennett from the Arabian Mission of the U.S. Dutch Reformed Church, then based in Basra, to establish a clinic in Kuwait City. In 1911
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there was a small hospital for men, which was designed by two U.S. engineers who were in the region – it was the first reinforced concrete building in the country. The doctor in charge was Dr. Stanley Mylrea who was from Britain but had trained in the United States. He ran the hospital until his death in 1952, by which time he had also established a church and a school adjoining the hospital. In 1919, another hospital had been established for women. The first significant medical care facility in the Emirate was the Olcott Memorial Hospital which was opened in 1934, with 34 beds. After World War II, with the advent of oil revenues, there was an expansion of the health services with the building of the Amiri Hospital which opened in 1949. In addition, the Kuwait Oil Company (K.O.C.) started its own clinics. This led to the establishment of a comprehensive health care system with free services for all the citizens in the country. It was not long before the general mortality rate was reduced, and the infant mortality rate was dramatically cut. As there were few Kuwaiti doctors, most doctors were from Egypt, gradually with Kuwaiti doctors being trained in the United States and Britain. Gradually courses were introduced at the College of Medicine at Kuwait University, and it was not long before many doctors from the region came to train in Kuwait. In 1983 the Arab Centre for Medical Literature was established in Safat as part of the ambition for the Council of Arab Ministers of Health seeing to encourage the publication of medical literature in the Arab world. Administratively, Kuwait is divided into six health regions, each with a general hospital run by the government. Given the small size of the country, this has shown a considerable investment in the health care service, with 17 hospitals in the entire country, with a total of 6,000 beds, or one for about each 350 people. In addition to these hospitals, there are many polyclinics, and 160 dental clinics. In total there are about 12,000 people in Kuwait working in health care, a figure which includes 2,500 doctors and 7,000 nurses, most still being expatriates. Medications prescribed by doctors are given fee from hospitals or government pharmacies, and the government undertake that if any citizen has health care needs which cannot be met within Kuwait will be treated overseas at government expense. The Iraqi invasion of Kuwait in August 1990, and their occupation until February 1991, led to damage
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to some of the main hospitals, partially from looting, but also from the fighting, and the flight or evacuation of many foreign medical personnel. Since the war, the Kuwaiti government established a clinic to care for those who suffered during the Iraqi Occupation—this includes the provision of trained psychologists to deal with traumas from the Gulf War. There has become increasing tensions in the country from non-citizens, especially Arabs living in Kuwait who, not being citizens, do not have complete access to the health care system in the country. SEE ALSO: Biological and Chemical Weapons; Iraq. Bibliography. Kuwait Today: A Welfare State (Quality
Publications Ltd., 1963); M. Hawley, Against the Fires of Hell: The Ecological Consequences of the Persian Gulf War (Harcourt, 1992).
Justin Corfield Geelong Grammar School, Australia
Kwarshiorkor Primary malnutrition is caused by a lack of adequate caloric intake rather than strictly lack of access to food, and most commonly affects children and the elderly. Secondary malnutrition is when a disease process decreases appetite, alters absorption, or disrupts nutrient metabolism. Kwarshiorkor refers to a state of primary malnutrition wherein the overall caloric intake may be adequate, but there is a severe lack of protein intake. The term kwarshiorkor comes from West Africa and is translated as “displaced child,” referring to the malnutrition seen after a child has been weaned from breast milk, a reliable source of protein. Kwarshiorkor is rarely seen in developed countries but is common in poor areas, regions of famine, places with limited food supply, or places with low levels of education. Several physical features are found in children with protein malnutrition. Children often only weight 60 to 80 percent of the weight expected for their age, and the height ranges from normal to decreased. They have a round and protuberant abdomen because of weak abdominal wall muscles, distention of the intestines, and an enlarged liver. Emotionally, children with kwarshiorkor are apa-
thetic when left alone and quickly become irritable and agitated when picked up or held. There is decreased pigmentation of the hair, leading to a reddish-brown, gray, or blond discoloration. The hair on the scalp may thin and fall out easily. The skin may lose pigmentation, and there may be easy desquamation, or shedding of the skin. There is an overall loss of muscle mass and swelling (edema). In late stages, kwarshiorkor can worsen to shock and death. Treatment depends on the condition of the patient. It is an emergency if the patient has reached the shock stage; treatment involves restoring and maintaining blood pressure. Refeeding can be difficult, and care must be taken to avoid refeeding syndrome complications such as fluid overload, electrolyte imbalances, heart arrhythmias, and diarrhea. Oral feedings are often not successful initially, especially if the caloric density of the food is too high. Resumption of caloric intake begins with slow introduction of carbohydrates to supply energy and then the addition of proteins. Treatment of kwarshiorkor early in the course of illness usually results in recovery, with few long-term consequences. However, in the late states, there may be stunting of physical growth and decreased intellectual abilities. If left untreated, kwarshiorkor is fatal. SEE ALSO: Child Development; Marasmus; Nutrition. BIBLIOGRAPHY. Don Nardo, Malnutrition (Thomson Gale,
2007); George W. Ware, Reviews of Environmental Contamination and Toxicology, Vol. 175, Dr. George W. Ware, ed. (Springer, 2002). Christine Curry Independent Scholar
Kyrgyzstan Kyrgyzstan is a landlocked country in Central Asia, bordered by Kazakhstan on the north, on the west by Uzbekistan, and on the east and south by China and Tajikistan. Kyrgyzstan is almost entirely mountinous, with more than half the country at an elevation above 2,500 m (8,200 ft) and 3 percent of the land covered with glaciers or snowpack. Kyrgyzstan became part of Russia’s empire in the 1880s and a constituent republic in 1936.
Kyrgyzstan
It became independent in 1991 after the collapse of the Soviet Union and ratified its constitution in 1993. The population is 5,284,000 and growing at 1.354 percent annually. The birth rate is 23.08 per 1,000 and the death rate is 7.02 per 1,000. Like many Central Asian states, it is losing a small number of people to migration, with 2.52 Kygyzstanis per 1,000 leaving country. Median age is 23.9 years. Life expectancy is 64.8 years for males and 73.02 years for females. Gross national income is $440 per person, with 40 percent living in poverty. More than 50 percent of the population works in agriculture. With 77 percent of Kygyzstanis having access to clean water and 59 percent using sanitary latrines, infectious and parasitic illnesses are not uncommon in Kygyzstan. However, while causing a fair amount of misery, communicable disease is responsible for only three percent of all deaths. Like its neighbors, the AIDS rate is low, with 0.1 percent of the population—about 4,000 people—believed to be infected with the virus. It has not yet moved into the general population, with most of those infecting being IV drug users, prisoners, and sex workers. The tuberculosis rate is rising, but is low for the region. External causes of death account for seven percent of deaths, with 96 deaths per 100,000 (compared with 40 deaths per 100,000 for the European Union). Eighty-six percent of deaths in Kygyzstan are the result of noncommunicable diseases. The major killer is cardiovascular disease, which accounts for 54 percent of all mortality in the country. Kygyzstanis have several risk factors for the development of cardiovascular disease, with high consumption of tobacco and alcohol prevalent for men, and high cholesterol and obesity common for women. High alcohol consumption and a high rate of viral hepatitis makes digestive diseases like cirrhosis and chronic liver disease another common killer. Child mortality rates are average for the region, with infant deaths at 58 per 1,000 and deaths for children under 5 at 67 per 1,000. Many Kygyzstani children live in orphanages and state-run institutions even though their parents are still alive; this is a pattern seen around the former Soviet Union, as families have been put under increasing pressures as a result of independent and economic reorganization. Bridal kidnapping and forced marriages still exist in some parts of Kyrgyzstan, although it is difficult
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to say how widespread the practice is. Early marriage is common, with a fertility rate of 2.68 children per woman. Contraceptive use is 60 percent, and 97 percent of women receive prenatal care and have a trained attendant during childbirth. Maternal mortality rates remain high at 110 deaths per 100,000 live births. Kyrgyzstan has agreed to the Millennium Development Goal (MDG) of reducing maternal mortality by 75 percent from 1990 levels by the year 2015, but rates have actually been increasing since 2002. Kyrgystan is attempting to restructure its medical system. The Soviet model emphasized number of staff and number of beds over outcomes, saddling the newly-independent republic with too many facilities and no system of quality control. While the reorganization is far from compete, the number of hospital beds has been reduced from 52,600 in 1990 to 26,594 in 2003. There are still 12,900 doctors and 31,561 nurses in the country, who tend to be poorly and irregularly paid. Total government expenditures on health care are $9.70 per capita. Kyrgyzstanis pay about 50 percent of their medical expenses out-of-pocket, often in under-the-table deals with doctors working outside the state system. See Also: Healthcare, Asia and Oceania.
“Kyrgyzstan,” CIA World Factbook, https://www.cia.gov/library/publications/the-world-factbook/geos/kg.html (cited July 2007); UNAIDS: The Joint United Nations Programme on HIV/AIDS, “Kyrgyzstan,” http://www.unaids.org/en/Regions_Countries/Countries/Kyrgyzstan.asp (cited July 2007); UNICEF, “Kyrgyzstan—Statistics,” http://www.unicef.org/infobycountry/ kyrgyzstan_statistics.html#30 (cited July 2007); World Health Organization, “A Guide to Statistical Information,” http://www.who.int/whosis/en/index.html (cited July 6, 2007); World Health Organization, “Health Care in Transition: Kygyrzstan,” http://www.euro.who.int/Document/ E86633sum.pdf (accessed July 6, 2007); World Health Organization, “Highlights on Health: Kygyrzstan,” www. euro.who.int/document/e88739.pdf (cited July 2007). Bibliography.
Heather K. Michon Independent Scholar
L La Montagne, John (1945–2004) John La Montagne was a Mexican-born American infectious disease biologist and administrator who contributed to the development of several vaccines. Both as a researcher and as a director of national programs, he fought the emergence of infectious diseases, including acquired immunodeficiency syndrome (AIDS) and severe acute respiratory syndrome (SARS), and was committed to improving global health. La Montagne helped to devise the swine flu vaccine, the pertussis vaccine, and remedies against childhood diarrhea and pneumonia. He also had a key role in the organization of the Multilateral Initiative on Malaria, an action of international cooperation involving agencies in many countries. During the last phase of his career, La Montagne also worked in the field of biodefense strategy. La Montagne was born in Mexico City, Mexico, in 1945. His father worked for General Motors in Mexico City, but La Montagne attended ��������������������� Lamar High School in Houston where he lived with his grandmother. He then went on to the University of Texas at Austin, receiving his bachelor’s degree in 1965 and a master’s degree in 1967. Four years later, he was awarded a Ph.D. from ����� Tulane University. During the early 1970s, he taught
at the University of Pittsburgh, where he also carried out research on the polio and flu vaccines. In 1976, La Montagne joined the National Institute of Allergy and Infectious Diseases (NIAID) of the National Institutes of Health (NIH) as the Influenza Program officer. In the early 1980s, he served as officer for important schemes such as the ������ Viral Vaccines ����������������������������������� Program and the Influenza and Viral Respiratory Diseases Program. In the second half of the 1980s, he became Director of the AIDS Program and of the Microbiology and Infectious Diseases Program. In 1988, La Montagne was appointed Deputy Director of NIAID. In these roles, La Montagne devised strategic plans to counter national and international crises due to the emergence or reemergence of viruses. He received many prestigious awards throughout his career, including the Public Health Service Special Recognition Award for leadership in childhood vaccine research programs, the Surgeon General’s Certificate of Appreciation, the Presidential Meritorious Executive Rank Award, the Distinguished Executive Award for his work in the areas of infectious diseases research of global health relevance, and most recently, the Secretary’s Award for Distinguished Service for the creation of strategies to respond to terrorist biological attacks. La Montagne died in Mexico City on November 2, 2004, of pulmonary ��������������������������� infarction edema.
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SEE ALSO: AIDS; Infectious Diseases (General); Virology. Bibliography. Joe Holley, “NIH Administrator John La
Montagne Dies” Washington Post (November 8, 2004).
Luca Prono Independent Scholar
Laboratory Tests Laboratory services form an essential component of health services. They share the same goal with all other components of health services, which is to promote health and to prevent disease. An important function of the laboratory services is to provide accurate laboratory tests. Laboratory tests are specific procedures that are conducted on patients or specimens obtained from patients to reveal information concerning their health status. These tests constitute a tool that contributes to provision of accurate information leading to proper diagnosis and correct identification of diseases, monitoring the treatment of patients and their response to it, investigating epidemics and the spread of infectious diseases, establishing a disease prognosis, and deciding disease prevention priorities. Laboratory tests can assist in answering important questions regarding the health of the individual such as what is cause of the disease? How severe is it? Was it correctly diagnosed? The role of laboratory tests as a main contributor to the health of the population should never be underestimated. The laboratory team consisting of laboratory technicians, technologists, and specialists should work as a cohesive unit and apply their knowledge and skills to provide the best possible services to the public, namely accurate and timely laboratory test results. The laboratory team should be suitably qualified for conducting the requested tasks, provided with continuous motivation including continuing education and career development, and should adopt a professional code of conduct that stresses the importance of ethics in such a sensitive career. This raises issues such as confidentiality of laboratory test results and safety of patients. Another important aspect of laboratory practice is laboratory safety. Ensuring the well-being of the laboratory team and prevention of all types of injuries
Laboratory tests can assist in answering important questions regarding the health of the individual.
can be achieved by several measures. Following established safety rules, conducting annual safety reviews, and raising the awareness of the laboratory staff about maintaining and promoting a safe work environment are among the most important measures. Human immunodeficiency virus (HIV), hepatitis B virus, and hepatitis C virus constitute the main hazardous biological exposures. Exposure to toxic chemicals represents another threat to the well being of laboratory workers, and developing biological and chemical exposure plans is required of all laboratories. The laboratory tests are usually conducted in various types of laboratories, varying in size, types of tests performed, level of specialization, and affiliation to different healthcare providers. They start from simple, basic laboratories in physicians’ clinics, to community-based primary healthcare laboratories, to district-level multidepartmental laboratories, and finally to central comprehensive laboratories and national reference laboratories. Some laboratories conduct few essential tests such as a complete blood count (CBC), urinalysis, stool examination, and basic biochemistry (e.g., fasting blood sugar and cholesterol). Whereas others conduct much more specialized tests, which may require the use of advanced methodologies and technologies including advance molecular pathology techniques such as polymerase chain reaction (PCR), cytogenetics, and hybridization techniques. Examples of tests that are conducted using advanced methods are tests used for diagnosing infectious diseases and genetic disorders. These laboratories can
be privately owned, affiliated with large national or regional companies, affiliated with nongovernmental organizations, or constitute a part of governmental health services. Large-size laboratories are often organized into departments. These may include hematology and coagulation, clinical chemistry, and clinical microbiology. The clinical microbiology department, for example, can be subdivided into sections such as bacteriology, virology, parasitology, and mycology. This, of course, applies to all other departments. Laboratory tests can also be performed at the site of the patient. This can be used in different settings such as clinics, emergency rooms, surgery theatres, and so forth, and can be termed point-of-care testing (POC) or alternative-site testing. The use of automation has changed the face of clinical laboratory sciences. Recent technological advances have led to increasing productivity and consistency, reducing hazardous exposures and cost in terms of money and human resources. Two important steps that should precede conducting laboratory tests are patient preparation, which involves explaining the type of test, the type of specimen to be collected, the estimated time for reporting the results, and ensuring the proper information concerning various factors that may influence the tests or the patient are obtained. Such information may include the fasting status of the patient, types of drugs he or she is taking, and diet. The second step is proper sample collection, which can range from simply voiding a sample of urine, to phlebotomy, to more complicated biopsies. Quality assurance is an important component of good laboratory practice. It involves the whole testing cycle including ordering a test, preparation of patients, obtaining specimens, handling and preparing specimens for analysis, conducting the analysis, implementing internal and external quality control schemes, and interpreting tests results. In each step, close commitment to quality assurance process is important. Laboratory tests can be ordered as individual tests or in different combinations called profiles or panels. Among the reasons for combining these tests are being disease specific, organ specific, or just general health checkup. Examples of theses panels include hypertension, diabetes, HIV, lipid, pancreatic, and thyroid, among many other panels. These panels are
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composed of various tests such as hepatic function panel (albumin, total protein, prothrombin time, alkaline phosphatase, alanine amino transferase, etc.), renal function panel (urea nitrogen, creatinine, phosphorus, sodium, potassium, chloride, etc.), and general health panel (complete blood count, uric acid, lipid panel, cholesterol, triglycerides, creatinine, etc.). SEE ALSO: American Society of Clinical Pathologists
(ASCP); Diagnostic Tests.
Bibliography. Monica Cheesbrough, Medical Labora-
tory Manual for Tropical Countries, 2nd ed. (ButterworthHeinemann Ltd., 1991); John Bernard Henry, Clinical Diagnosis and Management by Laboratory Methods, 20th ed. (Saunders, 2001). Abdullatif Husseini Birzeit University-Palestine
Lactose Intolerance Lactose intolerance is the inability of a person to digest lactose, the predominant sugar in dairy products. It affects people by causing gastrointestinal discomfort, and can make dietary freedom difficult for those afflicted. Lactose intolerance can be seen at birth (congenital), to develop on its own over time (primarily), or due to secondary afflictions than injure the intestinal lining. The incidence varies according to race. For primary lactose intolerance, about 75 to 90 percent of Native Americans, Blacks, Latinos, Asians, Mediterraneans, and Jews can be affected. On the other end, only 5 percent of northern and central European descendants are affected. This is thought to be due to a genetic mutation leading to a dominant gene for lactase persistence. For secondary lactose intolerance, it can occur at any age, and about 50 percent of infants with diarrhea will have it. There are many causes of lactose intolerance. In primary lactose intolerance, the amount of lactase enzyme normally declines gradually after weaning from breastfeeding. This is common in most land mammals and the loss is permanent. The diseases causing secondary lactose intolerance include rota-
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virus, giardia and other parasitic infections, inflammatory bowel disease, celiac disease, cystic fibrosis, and AIDS. Other medical treatment induced causes include chemotherapy, radiation injury, and bowel surgery. The length of time of secondary lactose intolerance persists depends on the causative factor. Lactose is normally broken down in the small intestine by the enzyme lactase into glucose and galactose. When lactose remains undigested and unabsorbed in the colon, it attracts water which remains in the gut and causes a laxative-like effect. Signs and symptoms of lactose intolerance include bloating, cramping, abdominal pain, diarrhea, flatulence, vomiting, and malnutrition. The amount of lactose consumed is not necessarily related to the severity of the symptoms. People of different ages and races will have varying severities of illness when consuming the same amount of lactose. Diagnosis of lactose intolerance can be done through multiple routes. There are various laboratory tests, as well as evaluating symptomatic response to ingestion of lactose containing products. (1) Stool acidity test: Stools will have low pH because undigested lactose ferments into lactic acid. Stool specimens must be fresh and processed immediately. (2) Lactose breath hydrogen test: Undigested lactose leads to the production of hydrogen in the gut. This is usually positive in 90 percent of patients with the condition when large doses of lactose are consumed. False-negative results may occur when the gut lacks its normal bacterial flora. Enemas and recent antibiotic use can contribute to this. Other factors such as aspirin use, smoking, and exercise may increase the hydrogen secretion and lead to false-positive results. (3) Lactose tolerance test: Normally, blood glucose levels should rise after digestion of lactose, thus in a lactose-intolerant individual who cannot digest lactose, there would be no obvious rise in blood glucose. (4) There are no diagnostic imaging studies to diagnose the condition, but biopsy of the small bowel may show enzyme deficiency. However, this is invasive and difficult to do. (5) A patient may consume lactose-free dairy products to determine if the symptoms are truly lactose intolerance or a possibly allergy to dairy products. Treatment for lactose intolerance consists primarily of decreasing lactose consumption. Fermented dairy products are better tolerated as well as whole milk. Having milk with other foods may also reduce
symptoms. Substitute milk with lactose-free milk, soy milk, or rice milk. Lactase supplementation through pills or solution added to milk or taken before dairy consumption may reduce symptoms. Treatment of lactose intolerance should also include treatment of the underlying causes of secondary lactose intolerance. Additionally, supplementation with calcium is important whether through ingesting other calciumrich foods or tablets. Women may need about 1,500 mg per day and men will need at least 1,000mg per day. Dietary sources of calcium include tofu, sardines, oysters, collard greens, and many others. People with lactose intolerance can make dietary alterations that will allow them to live life with less gastrointestinal discomfort. SEE ALSO: Allergy; Diarrhea; Gastroenterology.
American Gastroenterological Association, Web-based patient center, Lactose Intolerance, http://www.gastro.org/wmspage.cfm?parm1=854 (cited July 2007); R. Alexander Rusynyk and Christopher D. Still, “Lactose Intolerance,” Journal of the American Osteopathic Association (v.101/4, Supplement, 2001); Daniel L. Swagerty, Anne D. Walling, and Robert M. Klein, “Lactose Intolerance,” American Family Physician (v.64/9, 2002). Bibliography.
Kelli Glaser, D.O. Independent Scholar
Laos This landlocked south-east Asian country, which borders Thailand, Vietnam, China, Cambodia and Myanmar (Burma), was traditionally dominated by Thailand during the late medieval and early modern period. It then became a French protectorate from its incorporation into French Indochina in 1893, until it achieved independence as the Kingdom of Laos on July 19, 1949. In 1975 the communist Pathet Lao movement came to power and the country was renamed the Lao People’s Democratic Republic. Laos has a population of 5,924,000 (2006) with 24 doctors and 108 nurses per 100,000 people. Prior to the establishment of French colonial rule, there was little formal health care with most people liv-
Latvia
ing in isolated villages and relying on herbal remedies for the treatment of most ailments. During the French period, the colonial service opened small hospitals in Vientiane, the administrative capital, and Luang Prabang, the royal capital. Located in the two major cities in the country, the two hospitals generally only catered to European patients and also members of the small Lao elite. At independence, there was not a single Laotian doctor; all the doctors in the country being either French or from Vietnam, trained at the medical school in Hanoi which specialized in tropical diseases. After independence, a few medical missionaries worked in Laos, with Operation Brotherhood, operating from the Philippine Jaycee movement, and Dr. Tom Dooley ran medical missions in Laos, close to the Chinese border. With malaria posing a major health problem in the country, from 1956 until 1960, D.D.T. was sprayed over much of the country in an attempt to eradicate the mosquitoes. It was partially successful but had to stop because of the situation in the country which was heading for civil war. The war led to a rise in medical problems throughout the country, with poor nutrition accounting for many problems. The lack of access to clean water, and also environmental hazards such as fungal infections, have all added to the medical problems in the country which also come from malaria, dengue fever, amoebic dysentery, giardiasis and schistosomiasis (bilharzia). Because of the extensive growing of poppy in Laos, there have been problems associated with drug addiction, which has led to a rise in HIV/ AIDS cases, which have also increased from more widespread prostitution. The Ministry of Public Health in Laos now maintains hospitals in 15 of the 16 provinces in the country, and also runs clinics in 110 districts and many sub-districts. The Faculty of Medical Sciences at the National University of Laos, Vientiane, helps train doctors, and there is also an Institute of Traditional Medicine, dealing with traditional cures. There have also been some studies relating to Laotian communities overseas, some of which have helped with the treatment of people in Laos. SEE ALSO: AIDS; Herbal Remedies; Malaria. BIBLIOGRAPHY. Miguel A. Bernad, Adventure in Viet-
Nam: the story of Operation Brotherhood 1954-1957 (O.B.I.,
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1974); Agnes W. Dooley, Promises to Keep: The Life of Doctor Thomas A. Dooley (Farrar, Straus & Cudahy, 1962); Steven Holland, Impact of Economic and Institutional Reforms on the Health Sector in Laos: Implications for Health System Management (Institute of Development Studies, Brighton, U.K., 1995); Mary Lou Robertson, “Traditional and Acculturative Medical Practices Among the Ethnic Lao: A Study in Rockford and Elgin, Illinois,” South East Asian Review (v.9/1–2, 1984). Justin Corfield Geelong Grammar School, Australia
Latvia Latvia is located in the northeastern Europe, between Estonia and Lithuania with a coastline on the Baltic Sea. After years of domination by the Great Powers of Europe, the three states enjoyed a period of independence from 1918-40, only to be absorbed into the Soviet Union during World War II. Latvia regained independence in 1991. Latvia had less trouble transitioning to representative democracy and a free-market economy than other former Soviet states, and was admitted to the European Union in 2004. The population is 2,260,000. With a death rate of 13.64 per 1,000 compared to a birth rate of 9.43 per 1,000, the population is declining at 0.648 percent annually. Out-migration is also taking a toll, with 2.27 people per 1,000 leaving for life abroad. Median age is 39.6 years. Life expectancy is 66.39 years for males and 77.1 years for females. Gross national income is $6,760 per person. Almost 95 percent of the population works in industry or services, and the country has a generally good economic outlook, with a rising gross domestic product for the past several years. Mortality in Latvia is driven by noncommunicable diseases arising largely from poor lifestyle choices. Forty percent of males and 42 percent of females are obese. Over 50 percent of men and 19 percent of women over the age of 18 smoke daily. Alcohol consumption is high, with a strong preference for hard liquor, especially vodka. Alcohol is implicated in 180 deaths per 100,000, triple the average in the European Union. Drug use has been on the increase in recent years, with rising rates of both IV drugs, marijuana, amphetamines and Ecstasy.
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In all, 78 percent of Latvians die of noncommunicable diseases and 12 percent die from external causes such as accidents or self-inflicted injuries. Unintentional accidents are the leading factor in hospitalizations, and is the third leading cause of mortality. The death rate from injuries, including accidental poisionings, are the cause of 152 deaths per 100,000, compared to 39.4 deaths per 100,000 in the rest of the EU. The rate of suicides are also higher, with 31 deaths per 100,000, compared to 10 per 100,000 in the EU. Cardiovascular disease is the second-leading cause of morbidity and the leading cause of mortality. Ischaemic heart disease causes 320 deaths per 100,000, with cerebrovascular diseases responsible for 209 deaths per 100,000. These are much higher than the rest of the EU, where ischaemic heart disease causes 97 deaths per 100,000 and cerebrovascular disease causes 61 deaths per 100,000. Cancer is the thirdleading cause of mortality, resulting in 192 deaths per 100,000. The death rate from cervical cancer is three times the EU average. Communicable diseases cause about 1 percent of deaths annually. Clean water and good sanitation is widely available. Latvia is showing some worrying trends in tuberculosis and HIV infections. At 83.5 new cases per 100,000, the tuberculosis rate is eight times the EU average. The adult prevalence rate for HIV/AIDS is 0.8 percent, and there are 23 new HIV cases diagnosed per 100,000. (The EU average is just four cases per 100,000.) The increase in IV drug use is likely to drive the rates higher in the coming years. Latvia has a fairly complex health care system. Primary care physicians register with the state but are independent contractors; clinics are often owned by the municipalities, but run by private entities. Most hospitals are non-profit or joint-stock entities owned by the state or municipal governments. Because there is little by way of a social services structure or facilities, hospitals have found themselves overwhelmed in recent years by people who are not clinically sick but who have no place to go. See also: AIDS; Healthcare, Europe. Bibliography. “Latvia,” CIA World Factbook, https://
www.cia.gov/library/publications/the-world-factbook/ geos/lg.html(accessed July 2007); UNAIDS: The Joint
United Nations Programme on HIV/AIDS, “Latvia,” http://www.unaids.org/en/Regions_Countries/Countries/latvia.asp (accessed July 2007); UNICEF, “Latvia– Statistics,” http://www.unicef.org/infobycountry/latvia_ statistics.html (accessed July 2007); World Health Organization, “Health Care Systems in Transition: Latvia,” http://www.euro.who.int/document/e72467.pdf (accessed July 2007); World Health Organization, “Latvia: 10 Health Questions About the New EU Neighbors,” http://www.euro. who.int/Document/E82865LV.pdf (accessed July 2007). Heather K. Michon Independent Scholar
Lauterbur, Paul C. (1929– ) Paul Lauterbur is an American chemist who won the Nobel Prize in Physiology or Medicine in 2003 with Peter Mansfield for his development of magnetic resonance imaging (MRI). Thanks to its computerized scanning technology, the MRI produces images of internal body structures, particularly those with soft tissues. The MRI is particularly useful in the examination of the brain and the spinal cord, it gives surgeons precise information before they perform an operation, and has proved a fundamental tool in the diagnosis, treatment, and follow-up of cancer. It has also replaced more invasive techniques of examination, thus reducing suffering for patients. He was born on May 6, 1929, in Sidney, Ohio, where he attended Sidney High School. He studied as an undergraduate at Case Western Reserve University in Cleveland, Ohio, and obtained his Ph.D. in chemistry in 1962 from the University of Pittsburgh, where he apparently first conceived the project of the MRI, scribbling its first model on a table napkin in a diner. From 1969 to 1985, Lauterbur was a professor at the State University of New York at Stony Brook. He was then hired as professor by the University of Illinois at Urbana-Champaign where he also directed the ����������� Biomedical Magnetic Resonance Laboratory. Since the 1970s, Lauterbur started to work to apply nuclear magnetic resonance (NMR), first discovered in the 1950s by Felix Bloch and Edward Purcell, to produce images of the human body. Until then, NMR had been exclusively used to study the chemical structure
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of substances. Thanks to Lauterbur’s introduction of gradients in the magnetic field, the origins of the radio waves emitted from the nuclei of the objects of study can be detected, thus producing two-dimensional pictures. MRI soon became a widely-used medical tool, favorably compared to X-ray and computer tomography examinations for its lack of harmful side effects. In addition to the 2003 Nobel Prize, Lauterbur’s revolutionary discovery for the medical profession has been recognized with many prestigious awards, including the Eduard Rhein Foundation Technology Award, the American Physical Society Prize in Biological Physics, the Albert Lasker Clinical Research Award, the National Medal of Science, and the National Academy of Sciences Award for Chemistry in Service to Society. Lauterbur is a member of the National Academy of Sciences. SEE ALSO: Diagnostic Imaging; Nuclear Medicine. BIBLIOGRAPHY. Cindy Gill, “Magnetic Personality,” Pitt
Magazine (�������������������������������������������� Fall 2004), http://www.umc.pitt.edu/pittmag/ fall2004/feature1.html (cited ); Paul C. Lauterbur, “Autobiography,” http://nobelprize.org/nobel_prizes/medicine/ laureates/2003/lauterbur-autobio.html (cited July 2007).
Luca Prono Independent Scholar
Lead Poisoning Although the sources of lead exposure vary around the world, the detrimental health and behavioral effects are consistent. Definitions of what is considered “lead poisoning” or elevated levels have changed over time as scientific knowledge regarding the negative influence on the human body has advanced. Severe lead exposure can lead to coma, convulsions, and death. At lower levels of exposure lead is still toxic, especially among young children who are still developing, causing immediate health concerns as well as future cognitive and behavioral problems. Lead exposure is not just an acute condition that can be immediately addressed and forgotten. The effects of lead poisoning can be irreversible resulting in behavioral problems as well as becoming stored in
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bones to be released later during key physiological events such as pregnancy. Children across the world remain the population at greatest risk of exposure to lead, especially poor children living in large metropolitan areas or areas with older housing containing lead-based paint. Sources of Lead Exposure Lead is a dangerous threat to global health due to the many possible sources of exposure that vary based on age and geographic location. One source of lead exposure is water, when pipes and/or soldering around pipes used for water transportation are made of lead. Efforts in the U.S. have been made to remove lead plumbing, but doing so is costly and therefore not an option for all. Another source of exposure is lead-based paint in homes. U.S legislation passed in 1978 banned the use of lead-based paint, but this continues to be an exposure source when paint begins to peel and chip. Paint chips are often found on windowsills, usually at a height accessible to children where the chips can be ingested. Renovations in homes with lead-based paint can release dust into the air placing inhabitants at risk of inhaling the toxin. In metropolitan areas, soil is also a common source of lead exposure among children, a result of exhaust from cars that used leaded gasoline. Other possible sources of lead exposure include occupations (i.e. lead smelting, lead manufacturing and recycling industries), hobbies (i.e. making pottery, stained glass, and refinishing), folk remedies, and plates, glasses, and cans glazed with lead. Rates and Changing Definition of “Lead Poisoning” Over the past four decades every segment of the U.S. population has seen drastic decreases in lead levels due to the removal of lead from gasoline, paint, food and drink cans, and plumbing systems. According to the Centers for Disease Control and Prevention (CDC), average lead levels among children 1 to 5 decreased from 15.0 mcg/deciliter in 1976–1980 to 2.7 in 1991–1994. Despite declines in lead levels, approximately 1 million children in the U.S have levels associated with adverse effects, with the risk falling disproportionately on children who are poor, non-Hispanic black,
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Mexican American, and living in large metropolitan areas and in older housing. As rates have been decreasing so has the CDC’s definition of what is an elevated lead level due to advancing knowledge of the effects of lead. Before 1960 intervention was thought unnecessary with levels <60 mcg/dl. In 1960 the definition of lead poisoning dropped to 25 mcg/dl. Not until 1991 did this change when the CDC recommended individualized intervention when 15 mcg/dl or higher, and community efforts initiated with levels of >10. Despite this benchmark, some studies have argued lead levels <10 mcg/ dl can be harmful. Effects of Lead Poisoning The major detrimental effects of lead result from continuous exposure, with some long-standing effects observed after removal of the source. Lead in the blood mainly affects the brain and central nervous system. According to the U.S. Department of Health and Human Services, lead in the body has been linked to delayed cognitive development and reduced IQ. Lead exposure can also cause impaired hearing, kidney toxicity, impaired regulation of vitamin D, and limited functioning of red blood cells. In pregnant woman, acute exposure has been linked to increased stillbirths, pre-term deliveries, and low birth weight, as well as reduced gestational age, physical malformations, and decreases in growth stature. Elevated bonelead levels have also been linked to violent, antisocial, and delinquent behavior. Lead stored in bones can also become a source of exposure to fetuses, when past exposure to high levels of lead can become mobilized and passed through the blood stream. Prevention Efforts Currently in the U.S. lead poisoning prevention focuses on primary prevention, especially for children involving first and foremost eliminating exposure. Prevention efforts also include educating parents about what they can do to limit their child’s exposure to lead; there are several ways to limit exposure: washing children’s toys and hands after outside, keeping alert for peeling paint, and cleaning floors and windowsills with a damp mop as opposed to vacuuming. Other governmental efforts to reduce lead poisoning taken by agencies such as HUD include taking action when a lead-poisoned child is identified
such as covering lead-based paint surfaces, providing financial assistance to remove the paint, or requiring landlord’s to take action to ensure a safe environment for their tenants. SEE ALSO: Environmental Toxicology; Toxicology. BIBLIOGRAPHY. Centers for Disease Control and Preven-
tion, Preventing Lead Poisoning in Young Children (CDC, 2005); U.S. Department of Health and Human Services, Public Health Service, Agency for Toxic Substances and Disease Registry, The Nature and Extent of Lead Poisoning in Children in the United States: a Report to Congress (DHHS publication no. 99-2966, 1988); World Health Organization, “Water-related Diseases: Lead Poisoning,” http://www.who.int/water_sanitation_health/diseases/ lead/en/(cited July 2007). Noah Webster, M.A. Case Western Reserve University
Lean Body Mass Lean body mass is defined as the weight of the human body minus the body fat. Essentially lean body mass is constituted by the weight of organs, muscles, and bone. The reason why lean body mass is often calculated is because it gives an insightful perspective of weight. Often when an individual states that they would like to lose weight, it means they would like to decrease body fat and increase their lean body mass. However, it is not feasible to have no body fat and only lean body mass, because fat is necessary to maintain bodily functions. Some examples of the functions of fat are to help regulate body temperature and provide a cushion for organs, tissues, and the main form of the body’s energy storage. There are several variables to why people who are the same height have differences in the lean body mass between humans. The most important variables are things such as physiologic and metabolic factors, as well as the individual lifestyle. Usually, people try to manage their weight by using a height versus weight scale, such as body mass index (BMI), to determine if they are at a healthy weight. Although this method is better than not comparing one’s
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The most important method to increase lean body mass is to have a healthy low-fat diet, as well as regular weight bearing exercise. Strength training and increasing intake of protein helps to build lean body mass. In addition, aerobic exercise will help to expend more calories than consumption, thus it helps to lower body fat. The strength training is what helps to build lean body mass. Physical fitness paired with a good diet has a positive effect of increasing total muscle mass, maintaining a lower blood pressure, reducing blood cholesterol and low density lipoproteins and increasing high density lipids The calculation to determine lean body mass is different for both men and women. Lean Body Mass (men) = (1.10 x Weight(kg)) - 128 ( Weight2/(100 x Height(m))2) Lean Body Mass (women) = (1.07 x Weight(kg)) - 148 (Weight2/(100 x Height(m))2) SEE ALSO: Body Mass Index; Obesity. Bibliography. Arthur C. Guyton and John E. Hall, Text-
Essentially lean body mass is constituted by the weight of organs, muscles, and bone.
weight to the norm, it does not take lean body mass into account. Thus, an especially muscular individual may be categorized as overweight while he or she actually as a low percentage of body fat. BMI is still, however, generally the fastest and easiest calculator of body fat, and is useful for monitoring weight. In many parts of the world, especially the United States of America, it is becoming increasingly important for people to understand the concept of lean body mass. Furthermore, the desire to have healthy lean body mass and lower total body fat and increased. People with a low lean body mass, and high fat mass are at a major risk for serious diseases such as cardiovascular disease, hypertension, stroke, type 2 diabetes, and some forms of cancers. About 85 percent of people who have diabetes have type 2 diabetes. Furthermore, 90 percent of the type 2 diabetes population is overweight.
book of Medical Physiology, (Saunders, 2005); T.H. Hallynck, et al., “Should Clearance be Normalized to Body Surface or to Lean Body Mass?” British Journal of Clinical Pharmacology (v.11, 1981); R. Hume, “Prediction of Lean Body Mass from Height and Weight,” Journal of Clinical Pathology (v.19/4, 1966); Jack Valentin, Basic Anatomical and Physiological Data for Use in Radiological Protection (Elsevier, 2003). Angela Garner, M.D. Svetha Chunduri University of Missouri–Kansas City
Learning Disorders Samuel Kirk coined the term learning disabilities in 1963. In the broadest sense, all problems in learning may be considered learning disorders, but the term learning disabilities is reserved for specific problems in learning as noted in the Individuals with Disabilities Education Improvement Act. Learning disabilities involve a wide range of problems with oral and written language, reading, and mathematics. This can include problems with speech, reading, writing, spelling, mathematical calculations, and comprehension,
1000 Learning Disorders thinking, and reasoning. The common characteristic of learning disabilities is that the individual displays academic underachievement in the affected domain. Not all children who underachieve have learning disabilities. Underachievement may be due to behavioral, emotional, motivational, intellectual, or other factors. Furthermore, learning disabilities may coexist with other developmental disorders, such as attention disorders. Learning disabilities affect some combination of getting information into the brain, making sense of the information, and retaining and retrieving the information. Thus, acquisition and organization of information can be affected as well as how the information is comprehended and remembered. Learning disabilities may be primarily verbal or they may be nonverbal. One or more of the processes related to perceiving, thinking, remembering, or learning is affected. Learning disabilities are considered to be neurobiological disorders in which how a person’s brain functions or is structured affects one or more of the basic processes involved with oral or written language or with mathematics. Current technological advances in neuropsychological research methods (i.e., positron emission tomography (PET), magnetic source imaging (MSI) and magnetic resonance spectroscopy (MRS) are beginning to yield insights into the biology behind the disabilities. For example, functional magnetic resonance imaging (MRI) studies have revealed that those with reading problems show less activity in left posterior brain regions and greater reliance on Broca’s area. As disorders of the central nervous system, many potential causal factors have been implicated including heredity and pre- and postnatal factors. While there are familial tendencies to learning disabilities, the disorder may manifest differently in different generations: for example, a parent may have a writing disorder while the child has a reading problem. This suggests a subtle brain dysfunction may be inherited as opposed to direct inheritance of a specific disorder. As the brain develops during pregnancy, disruptions caused by illness, alcohol, or smoking may cause errors that later manifest as learning disabilities. Head injuries or environmental toxins have been implicated as possible postnatal factors. It is estimated that 5 to 15 percent of North American children have a learning disability with higher
prevalence rates for boys than for girls; however, this may be due to differences in referral patterns. Learning disabilities are developmental in nature and are typically diagnosed during childhood; occasionally, they can first be identified in adults, although they would have been present earlier. Most children will have a documented history of learning problems in school. Children with significant delays in skill development are often first suspected as having possible learning problems. A child who suddenly develops learning problems that were not present earlier more likely has a behavioral or emotional disorder than a learning disorder. The diagnosis of a learning disability should be made by a licensed professional such as a psychologist. The diagnosis is arrived at after a thorough history including developmental, family, and school histories and the results of standardized tests of both intellectual ability and academic achievement. Children with learning disabilities typically also have problems with working memory (remembering verbal information while they are manipulating this information) and they may have a variety of deficits in executive functioning tasks such as planning and concentration. Learning disabilities must be distinguished from normal variations in academic ability. Children whose learning problems primarily stem from visual, hearing, or motor problems are excluded from the diagnosis. Furthermore, the diagnosis does not apply to those whose problems in learning stem from mental retardation or cultural, economic, or environmental disadvantages. For example, it does not apply to a child who is struggling to keep up in the classroom, but who is receiving academic instruction in English for the first time. Best practice requires evidence of a deficit in a logically related process linked to the area of academic achievement. For example, a weakness in phonological processing may be linked to the difficulty in learning to read through normal classroom instruction in an otherwise intellectually normal child. Other professionals may be consulted as needed; for example, a speech and language pathologist may be consulted for language-related disorders, or an audiologist for hearing problems. There are different classification systems in use for the diagnosis of learning disabilities. The Diagnostic and Statistical Manual of Mental Disorders, 4th edition, technical revision (DSM-IV-TR) recognizes
three broad categories of learning disabilities, known as Reading Disorder, Mathematics Disorder, and Disorder of Written Expression. The DSM uses the term disorders rather than disabilities and formerly referred to these as Academic Skills Disorders. The most common learning disability is a problem with reading. The essential feature of Reading Disorder (previously called Dyslexia) is reading achievement in terms of accuracy, speed, or comprehension in either silent or oral reading that is substantially below what is expected based on age, schooling, and intellectual ability. The reading difficulty significantly interferes with academic achievement. Due to the fact that the DSM requires a child to have a statistically significant deficit in academic achievement for a learning disability to be diagnosed, most reading disorders are not diagnosed until the child is in first grade or later and especially in the case of higher-functioning children, not until the fourth grade or later. Reversing letters, while commonly associated with dyslexia, is less predictive of reading difficulties than failure to associate common phonemes (sounds) with letters. In fact, there is now substantial evidence that the core deficit in reading disorders is a problem with phonological processing (the sound structure of language). Children with reading disorders may also have disorders in mathematics and writing. Mathematics Disorder and Disorder of Written Expression are less frequently diagnosed independent of Reading Disorder. Mathematics Disorder involves difficulties with counting, understanding mathematical terms or operations, and reading numbers, signs, or word problems. While the inability to count accurately or confusion about number concepts can appear early, this disorder is usually diagnosed later than Reading Disorder. Disorder of Written Expression involves poor written text (i.e., grammar and punctuation errors) along with poor spelling and handwriting. Normally, evidence of poor spelling or handwriting alone is not sufficient for the diagnosis. This disorder is more difficult to diagnose due to limitations in available standardized tests. While the DSM-IV-TR recognizes that there may be underlying cognitive processing difficulties (such as with attention or memory) associated with learning disorders, psychological processing difficulties are central to the diagnosis according to the Individuals with Disabilities Education Improvement Act (IDEIA)
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of 2004. As learning disabilities have come to be seen as educational rather than medical disorders, the diagnostic criteria provided by IDEIA have taken center stage. IDEIA focuses on achievement that is not commensurate with age and ability. It requires a problem in one or more of the psychological processes related to listening, thinking, speaking, reading, writing, spelling, or the performance of mathematical calculations. A discrepancy between ability and achievement is not required; underachievement in the domain affected, for example, reading is required. Learning disabilities are typically lifelong and they range from mild to severe. Severity of the learning disability and overall level of intelligence are major predictors of the impact of learning disabilities. In milder cases, academic achievement may be affected without slowing progress through the grades; in more severe cases, adolescents may leave school prior to graduation and employment may be affected. How well the child responds to educational interventions and both the child’s and the family’s coping skills are predictive. In fact, some would argue that the diagnosis be reserved for those who do not respond well to targeted intervention. If left untreated, adolescents tend to drop out of high school, are more likely to engage in drug and alcohol abuse and have difficulties sustaining successful employment; however, once the demands of the classroom are left behind, their learning disabilities have less impact. The majority of individuals with learning disabilities function well in society, but work, family, and relationships can be affected. As many as 75 percent of individuals with learning disabilities have associated deficits in social skills. The child may have difficulties reading social cues, such as facial expressions, body language, or tone of voice. The child may be unable to take the perspective of another due to problems with perception. Some individuals with learning disabilities may have problems with movement affecting balance and coordination so that they are considered clumsy. These children may then be rejected by their peers due to their odd behavior or poor school performance. Friendships and family relations may be affected and the individual may have low self-esteem and a lowered social status. In the United States and Canada, individuals with learning disabilities are protected under laws requiring accommodations so that qualified individuals have access to educational and employment opportu-
1002 Lebanon nities. With the proper diagnosis, public schools must provide an appropriate educational program for the affected child. Many colleges and universities have disability offices to assist learning-disabled students on their campuses. Learning disabilities are treatable and they can be overcome, but they are not curable. Treatment options in school settings range from tutors and resource help to resource classes and special schools. After assessing the child’s individual learning strengths and weaknesses, an individualized education plan (IEP) is developed for the individual. The IEP identifies what needs to be taught. Identified students are entitled to accommodations, that is, to tools and procedures designed to lessen the effects of the disability. Modifications to a curriculum may reduce the learning expectations and thus increase the discrepancy between achievement and grade-level expectations, but this is not the intent of accommodations. Individualized skills-based strategies have been shown to be very effective. Assistive technology can also be utilized. This can range from books on tape and calculators to computer-based reading and writing programs. The most effective intervention programs are multifaceted. A variety of instructional methods should be utilized. For example, both phonics and whole language approaches to reading can be tried. Teaching strategies such as checking completed assignments and making a plan can be effective. Students can be expressly taught to recognize when they do not know or understand the material, so that they can get help immediately. Using the individual’s strengths to overcome weaknesses can be used both to promote school learning and to improve social skills. Problem-solving skills, memory techniques, and study habits can all be taught directly. Many of these strategies involve metacognition or knowing what one knows. The field of learning disabilities remains controversial. Consensus has not been reached on the very definition of learning disabilities as there is considerable disagreement as to whether use of ability/achievement discrepancies as a criterion for diagnosis is valid. If a significant discrepancy is not required, a child who has reading difficulties due to weaknesses in phonological processing has a reading disability regardless of the child’s IQ. There is still no consensus on etiology, diagnosis, or treatment. Yet, more and more indi-
viduals are being identified with learning disabilities and this field will continue to evolve. SEE ALSO: Attention Deficit Disorder; Child Behavior Dis-
orders; Child Mental Health; Dyslexia; Hyperactivity.
Bibliography. C. Cortiella, No Child Left Behind: Deter-
mining Appropriate Assessment Accommodations for Students with Disabilities (Ldonline.org, 2005); Diagnostic and Statistical Manual of Mental Disorders, 4th ed. technical revision (American Psychiatric Association, 2000); IDEIA: Individuals with Disabilities Education Improvement Act of 2004, Pub L. no. 108-146; R. Kamphaus, M. Quirk, and A. Kroncke, “Learning Disabilities,” R. Kamphaus and J. Campbell, eds., Psychodiagnostic Assessment of Children (Wiley, 2006); J. Sattler, Assessment of Children: Behavioral and Clinical Applications, 4th ed. (Jerome M. Sattler, 2002); S. Shaywitz, Overcoming Dyslexia (Knopf, 2003); K. Stanovich, “The Future of a Mistake: Will Discrepancy Measurement Continue to Make the Learning Disabilities Field a Pseudoscience?” Learning Disability Quarterly (v.28/2, 2005); C. Turkington and J. Harris, The Encyclopedia of Learning Disabilities, 2nd ed. (Infobase Publishing, 2006). Elizabeth Levin, Ph.D., C.Psych. Laurentian University
Lebanon Lebanon is located in the Middle East, with a western coastline along the Mediterranean. It shares borders with Syria to the north and east and Israel to the south. Prior to the Lebanese Civil War (1975-90), Lebanon had a largely modern society and infrastructure. As center of international banking for the region, it was sometimes called the “Switzerland of the Middle East.” Recovery from the war was slow, and marked with political and economic hardships. In the summer of 2006, Lebanon was drawn into a brief war with Israel, leading to the fresh destruction of much of the country’s infrastructure. The population is 3,925,000 and growing at a rate of 1.198 percent annually. The birth rate is 18.08 per 1,000 population and the death rate is 6.1 per 1,000 population. Median age is 28.3 years, with more than half the population under the age of 25. Life expectan-
cy is currently 70.67 years for males and 75.77 years for females. Gross national income ins $6,180, with about 28 percent of Lebanese living below the poverty line. Political instability and the 2006 war with Israel has hampered economic growth. Lebanon carries a double burden of disease, with communicable and non-communicable diseases both impacting on the people’s health. Statistics on the communicable disease burden are incomplete,but it is known that infectious or parasitic disease cause 8.3 percent of deaths annually. In 2006, there were 644 cases of measles. There were also 57 cases of malaria, all of them imported from other countries. HIV/AIDS has an adult prevalence rate of 0.1 percent, and there are about 700 new cases of tuberculosis each year. Cardiovascular disease is the major cause of mortality, causing 46.3 percent of all deaths, or 305 out of every 100,000. Ischaemic heart disease is responsible for about half those fatalities. Care and management of heart disease is highly advanced in Lebanon, and the country has the one of the world’s highest rates of cardiac catherization. Undefined “chronic” disease accounts for 22 percent of mortality, external causes or injuries for 13 percent, and cancers for 10 percent. The 42-day war with Israel in the summer of 2006 displaced 1 million Lebanese. Close to 2 million were left with little or no clean water. Almost 1,200 were killed and 5,000 were wounded. Hospitals were pushed to the breaking point by the influx of casualties, and quickly ran low on supplies, power and equipment. There were also charges that the Israeli Army deliberately targeted ambulances and hospitals. Many facilties are still struggling to rebuild. Children also continue to suffer from the aftermath of war. About 50 schools were totally destroyed in the bombing, and 300 (about 10 percent of all schools) were damaged. A third of the wounded were children. Aid organizations have been running programs to give children a place where they can gather to play or share experiences, while at the same time allowing aid workers to monitor health and nutrition levels. Almost 90 percent of health care is provided by the private sector. They offer a high level of service, but it is focused primarily on curative, not preventative care. Coordination between the private sector and the state has improved in recent years, but there is still little coordination between entities particularly in the gathering of statistical data or epidemiological surveil-
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lance. The number of physicians working in Lebanon is growing at 8.3 percent annually, but there is a severe shortage of nurses and paramedical staff. The World Health Organization noted in 2003 that there were 23.1 physicians, 11.6 nurses, and 39.7 health workers per 10,000 people. SEE ALSO: AIDS; Heart Diseases, General; Malaria. Bibliography. “Can Lebanon conjure a public health
phoenix from the ashes?”, BMJ (British Medical Journal); www.bmj.com/cgi/content/full/333/7573/848?q=y (cited July 2007); “Global InfoBase”. World Health Organization, www.who.int/infobase/report.aspx (cited July 2007); “Health Action in Crisis: Lebanon,” World Health Organization, www.who.int/hac/crises/Lebanon_Aug06.pdf (cited July 2007); “ Humanitarian Action Report 2007 - Lebanon,” UNICEF, http://www.unicef.org/har07/index_37564.htm (cited July 2007); “Lebanon” CIA World Factbook, www.cia. gov/library/publications/the-world-factbook/geos/le.html (cited July 2007); “Lebanon—Statistics,” UNICEF, www. unicef.org/infobycountry/lebanon_statistics.html (cited July 2007); “Lebanon,” UNAIDS: The Joint United Nations Programme on HIV/AIDS, www.unaids.org/en/Regions_ Countries/Countries/lebanon.asp (cited July 2007). Heather Michon Independent Scholar
Lederberg, Joshua (1925– ) Joshua Lederberg is an American molecular biologist who obtained a share of the 1958 Nobel Prize in Physiology or Medicine with Edward Lawrie Tatum and George Wells Beadle for his research on the genetic structure and function of microorganisms. Together with genetics, Lederberg’s other main field of research is artificial intelligence. He worked for the National Aeronautics and Space Administration (NASA) experimental programs to detect life on Mars and contributed to the development of Dendral, a system designed to analyze mass spectra. Lederberg was born in Montclair, New Jersey, on May 23, 1925. He attended Stuyvesant High School in New York City from where he graduated at the age of 15. In 1941, he enrolled at Columbia College,
1004 Leg Injuries and Disorders obtaining his B.A. in Zoology three years later. From 1944 to 1946, he conducted further research in zoology under the supervision of Professor F. J. Ryan. Lederberg was then Research Fellow of the Jane Coffin Childs Fund for Medical Research in the Department of Microbiology and Botany at Yale University, and worked with Professor E. L. Tatum from 1946 to 1947. He was awarded his Ph.D. degree in 1948. Lederberg started his academic career as an assistant professor of genetics at the University of Wisconsin in 1947. He progressed quickly, becoming Associate Professor in 1950 and Professor in 1954. He was responsible for organizing the Department of Medical Genetics in 1957, also acting as its chair for a year. It was while at the University of Wisconsin that Lederberg developed his research on the process of transduction between bacteria that earned him the Nobel Prize. Lederberg demonstrated how bacteriophages could transfer genetic information among bacteria in salmonella. This phenomenon explained how different bacteria could quickly develop resistance to the same antibiotic. In 1959, Lederberg was hired by Stanford University Medical School, where he supervised the establishment of the Department of Genetics, becoming then its Executive Head. While at Stanford, he became interested in the biological impact of space explorations, warning that extraterrestrial viruses could spread on Earth. He advocated quarantine for astronauts and sterilization for the equipment. In 1978, Lederberg was appointed President of Rockefeller University and remained in that position until 1990. Throughout his career, Lederberg has received prestigious awards such as the National Medal of Science and has taken part in several important governmental committees, including Jimmy Carter’s Cancer Panel and the Task Force on Persian Gulf War Health Effects. SEE ALSO: Antibiotics; Genetics. Bibliography. Estelle Gilson, “An Ache to Learn: Joshua
Lederberg,” Columbia Magazine (October 1984), http:// profiles.nlm.nih.gov/BB/B/B/M/Q/_/bbbbmq.pdf (cited ); Joshua Lederberg, “Untitled Autobiography,” The Joshua Lederberg Papers http://profiles.nlm.nih.gov/BB/G/C/G/ I/_/bbgcgi.pdf (cited July 2007). Luca Prono Independent Scholar
Leg Injuries and Disorders Because the legs bear the entire weight of the body, their bones, blood vessels, muscles, and ligaments are often prone to injuries such as sprains, strains, tears, dislocations, and fractures and to a number of disorders that may be present at birth or which develop over time. Disorders, such as hemiplegia, diplegia, and quadriplegia, may be either congenital, or they may result from diseases or accidents. Conditions such as osteoarthritis and bursitis may attack the joints of the legs, particularly if there have been prior injuries in those locations. Blood vessel disorders of the legs include varicose veins (dark-colored enlarged veins) and deep vein thrombosis (blood clots that may potentially lead to heart attacks and strokes if left untreated). Leg injuries are often associated with particular occupations. Knee disorders, for instance are common among wrestlers, lacrosse players, football players, soccer players, coal miners, and carpet layers. Many farmers experience hip disorders. Both soccer players and ballet dancers are prone to disorders of the ankles and feet. Treatment for leg injuries is based on the location and extent of injuries. Common therapies include joint protection, lifestyle changes, nonsteroidal and anti-inflammatory drugs, analgesics, acetaminophen, exercise, rehabilitation, surgery, and joint replacement. Any part of the leg, which includes the knees, feet, ankles, and hips, may be affected by malformations and disorders. Malformations of the leg may be either unilateral (occurring only in one leg) or bilateral (occurring in both legs). In some cases malformations are the result of spurs or joint deterioration. Some leg disorders occur at any point in the lifespan, while others chiefly affect specific age groups. Club foot is present at birth, and congenital dislocations and coax vara (characterized by bowed legs and a waddling gait) tend to appear in infancy. Blount’s disease, a growth order that causes the legs to bow outward just below the knees, is usually evident by the age of 4. Toxic synovitis (acute hip pain) generally attacks between the ages of two and nine or appears at puberty. Legg-Calvé-Perthes (a temporary hip disorder) surfaces between 3 and 12 years. Slipped capital femoral epiphysis is generally limited to individuals between the ages of 10 and 15, and osteoid osteoma (a benign bone lesion) exhibits in individuals between the ages of five and 30. In most cases, degenerative arthritis and neuropathic joint disease do
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Leg injuries are often associated with particular occupations. Knee disorders, for instance are common among wrestlers, lacrosse players, football players, soccer players, coal miners, and carpet layers.
not create problems before the age of 40. Individuals of any age may experience infection, trauma, malignancy, rheumatoid arthritis, and aseptic necrosis. The foot The four parts of the foot include the rear foot, the ankle joint, the midfoot, and the forefoot. It is estimated that at least 80 percent of the general population has foot problems. Problems with the feet are particularly common in women because of the shape and height of the shoes that dictate women’s fashions. Pain in the hindfoot, including the heel, often results from faulty footwear that fails to distribute support throughout the foot. Common disorders of the hindfoot include spurs, tarsal tunnel syndrome, and tibialis tendon subluxation. Pain in the midfoot may result from plantar fasciitis, flexor hallicus longus tendonitis, plantar fibromatosis, tarsonavicular
osteochondritis, and midfoot degenerative joint disease. Diseases of the forefoot include metatarsalgia, Deutschländer’s disease, Freiberg’s Disease, Morton’s Neuroma, sesamoiditis, and psoriasis. The most common injuries in the foot are ankle sprains and strains, which are ranked according to severity: Grade I, mild, Grade II, moderate, and Grade III, severe. Athletes are particularly prone to injuries of the foot and ankle, and incidences of these injuries are on the rise. Shoes that provide absorption are extremely important for athletes because they help to prevent overuse attenuation injuries. Many foot injuries are specific to particular sports. Among runners, six percent of all injuries arise from stress and fatigue injuries. Aerobic and ballet dancers are likely to experience sesamoid fractures, tendonitis, and stress fractures. Basketball players often suffer from
1006 Legionnaire’s Disease fifth metatarsal base fractures, stress fractures, and tendonitis; and basketball players experience talonavicular joint injury, ankle sprains, and osteophytes. Football players are even more prone to leg injuries, suffering from sesamoid fractures, ankle fractures, sprains, turf toe, tasso metatarsal fractures, and dislocations. Likewise, hockey players are beset with puck injuries and fractures, contusions, ankle and hindfoot injuries, exostoses (formation of new bone onto existing bone), and bursitis. The knee The knee joint, which is located at the ends of the tibia and the femur, is highly susceptible to traumatic injury. The knee depends on the ligaments and muscles that surround it to provide strength and stability. For this reason, the knee is a common site of injury among athletes. Several diagnostic systems have been developed to determine the extent of knee damage. They all use some method of determining the intensity of pain, the amount of swelling, the affect of the injury on physical activity, and whether or not symptoms such stiffness, grinding, or locking are present. In addition to patient responses, medical professionals are also able to use such equipment as X-rays and ligament testing devices to determine displacement of knee joints and identify fractures and tears. Malformations of the knee, like those in the rest of the leg may be either unilateral or bilateral. The first signs of knee problems may occur when individuals discover they are experiencing pain and/or gait disorder or having difficulty descending stairs or rising from a sitting position. As early as 1906, physicians identified the condition known as chondromalacia patella, which affects 50 percent of individuals between the ages of 15 and 25 and the majority of the population over the age of 60, particularly females in these age groups. It is characterized by vague discomfort in the affected area, becoming worse with physical activity or after sitting with the knee bent for prolonged periods. Excessive malformations of the knee are sometimes referred to as “miserable malignant syndrome.” A condition known as prepatellar bursitis is common among people who spend a good deal of time on their knees in their occupations (plumbers and athletes, for example) or for pleasure (gardeners, for instance), those who have sustained injuries, and who
suffer from conditions such as rheumatoid arthritis and gout. Swelling on the top of the knee is evident, and the pain may be so severe that lifestyle and work practices must be adjusted. In milder cases, ice and elevation have been used successfully. The most common disease to attack the hip in adulthood is osteoarthritis, and it often affects sites where injuries occurred in childhood or early adulthood. In severe cases, adults, particularly females, may suffer from spontaneous hip dislocation. When musculoskeletal diseases attack the hip, patients may experience loss of joint movement, weakness in the muscles, gait abnormalities, and joint deformities. Pain is a major factor in most cases. The exception is when the disease is a congenital dislocation of the hip, coax vara, or charcot joint. Hip pain may be experienced directly in the hip of it may be referred to any part of leg, particularly in the knee. SEE ALSO: Birth Defects; Gerontology; Hip Injuries and
Disorders; Infant and Toddler Health; Knee Injuries and Disorders; Sports Injuries.
Bibliography. Hadler Nortin, Medical Management of
the Regional Musculoskeletal Diseases (Grune and Stratton, 1984); David J. Magee, Orthopedic Physical Assessment (W.B. Saunders, 1997); Mark D. Miller, et al, Review of Sports Medicine and Arthroscopy (W.B. Saunders, 2002); Chad Starkey and Glen Johnson, Athletic Training and Sports Medicine (Jones and Bartlett, 2006); Philip R. Reilly, Is It in Your Genes? The Influence of Genes on Common Disorders and Diseases That Affect You and Your Family (Cold Spring Harbor Laboratory Press, 2004). Elizabeth R. Purdy, Ph.D. Independent Scholar
Legionnaire’s Disease In the last few decades, Legionnaire’s disease has emerged as an important cause of human morbidity and mortality and has been implicated in a wide spectrum of human disease. Although it is not spread by human transmission, it is ubiquitous in the environment and aerosol exposure to contaminated water has been responsible for outbreaks both in the community and
hospitals. As the body relies on cell-mediated immunity to help fight the disease, the most susceptible people are the elderly, hospitalized patients, and the immune suppressed. If treated with appropriate antibiotics the mortality is low, but the clinical syndrome is vague and diagnosis relies on specialized laboratory tests. Control is possible through careful monitoring of water sources along with appropriate decontamination. Introduction In summer 1976, participants of an American Legions conference in Philadelphia began to fall ill with a mysterious pneumonia. The illness, dubbed Legionnaire’s disease, led to 34 deaths among the 221 people affected. Ultimately, Legionella pneumophilia, a novel gram-negative bacterium, was isolated from harvested lung tissue of the epidemic’s victims. Over the last three decades, over 40 species and 64 serotypes of Legionella have been identified. Most have been isolated from the environment and nearly half have been implicated with human disease. L. pneumophilia remains the most clinically significant species accounting for over 80 percent of Legionellosis cases in the United States and is being increasingly recognized as a fairly common cause of pneumonia in adults. Legionella infections may be sporadic or epidemic, community or hospital acquired. Epidemiology Epidemiologically, there are three main requirements for a Legionella infection to occur: a contaminated source, a means of dissemination, and host susceptibility. Water is the only documented source of Legionella species, particularly the surface waters of rivers, lakes, and reservoirs, and drinking water. Man-made sources include cooling towers and potable water distributions systems. Freshwater amoebas serve as a reservoir and have been found to facilitate the growth of the bacteria. Another factor that supports the survival of Legionella in natural or treated water is its relative resistance to heat and chlorination, which is why it can thrive in normally inhospitable environments such as hot-water tanks. Transmission occurs through inhalation of aerosols or aspiration of contaminated water. Documented sources of dissemination include cooling towers, humidifiers, respiratory therapy equipment, whirlpool spas, evaporative condensers, hot-water supplies, and potable wa-
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ter distributors (e.g., showers, faucets). Because numerous activities, including taking a shower and flushing a toilet, can produce aerosols in the environment, it is often difficult to identify the source of infection. Direct infection of wounds after contact with contaminated water has also been documented. No human-to-human transmission has ever been documented. Host susceptibility to Legionella depends on both specific and nonspecific defenses. Processes that compromise the mucociliary action of the upper respiratory tract, such as smoking, can leave a person more vulnerable to infection. Other significant risk factors include chronic lung disease, end-stage renal disease, diabetes mellitus, and advanced age. Immunosuppression (e.g., malignancy, corticosteroid therapy, human immunodeficiency virus) has been shown to be the most important factor in the development and severity of infection. Surgery (especially head/ neck, transplant procedures) has also been shown to predispose a patient to hospital-acquired infections. Infections are more common in the summer months, presumably because there is an increased use of aerosol-generating cooling systems and improved growth conditions for the organism. Pathophysiology Legionella infections begin in the lower respiratory tract. Once the bacteria reach the alveoli, they undergo phagocytosis by alveolar macrophages. Unfortunately, Legionella is a facultative intracellular parasite with the ability to block the normal killing action of the macrophage. Thus, instead of killing the microorganism, the macrophage becomes a reservoir for the bacteria to proliferate intracellularly until the cell ruptures releasing more bacteria to go on and infect other cells. The body’s primary immune response to Legionella infections rests on cell-mediated immunity. Immunologically activated monocytes and macrophages restrict intracellular bacterial growth through cytokines which regulate the body’s antimicrobial activity against the bacteria. Also lymphocytes have been shown to be extremely active during an infection. Clinical Syndromes There are two distinct clinical syndromes associated with Legionella. The first and most common is an acute pneumonia referred to as Legionnaire’s
1008 Legionnaire’s Disease diseases. The second, and much less common form, is a viral-like syndrome known as Pontiac fever named after the city in Michigan where the firstknown epidemic occurred. Legionnaire’s Disease Legionnaire’s disease can vary in severity from a mild illness (walking pneumonia) to a fatal multilobular pneumonia. The incubation period is two to ten days. Typical symptoms are nonspecific and include headache, confusion, weakness, muscle aches, malaise, fatigue, fever, and chills. Prominent gastrointestinal disturbances often occur and may include diarrhea (watery, nonbloody), nausea, vomiting, and abdominal pain. In neonates, Legionnaire’s disease can be manifest as fulminant sepsis and/or pneumonia which progresses rapidly to respiratory failure and death. The classic patient presentation is a chronically ill, middle-aged smoker with a high, unremitting fever, nonproductive cough, diarrhea, confusion, low sodium, and abnormal liver function tests. As the disease progresses, the cough can turn productive with purulent sputum. Chest pain is common and progressive shortness of breath is the rule. Legionella may also infect lymph tissue, brain, kidneys, liver, bone marrow, and heart, although extrapulmonary infection is rare. Pontiac Fever Pontiac fever is an acute flu-like illness that begins with an abrupt onset. The incubation period is 24 to 48 hours. Symptoms include fever, headache, weakness, and severe muscle aches. Neurological disturbances such as dizziness, ataxia, confusion, irritability, nightmares, and neck pain or stiffness are common. Patients may or may not have a cough and sore throat. The disease is self-limiting with symptoms lasting approximately one week with full recovery taking weeks. Pontiac fever tends to occur in outbreaks and has an infection rate greater than 90 percent. Diagnosis Legionella can be suspected clinically but can only be confirmed through laboratory testing. Some general nonspecific laboratory examinations may show low blood sodium and other chemical abnormalities. Protein and blood in the urine are often seen on urinalysis. The gold standard for diagnosis is culture from respiratory secretions or other specimens on special
media. A rapid urinary antigen test is available to help in diagnosis, although it only detects L. pneumophilia serotype 1, the most common cause of Legionnaire’s disease. Other tests such as direct fluorescent antibody testing, polymerase chain reaction, and serologic tests are available but are not as widely used. Treatment and Prognosis Response to antibiotic therapy is generally quick, although convalescence may last many weeks to months. Fluoroquinolones, macrolides, tetracycline, and rifampin have been shown to be effective in the treatment of Legionella infections. The antibiotic treatment of choice is azithromycin. Rifampin has been shown to be beneficial when added to treatment regimens in severe cases. With appropriate therapy, the mortality of Legionnaire’s disease varies from around 5 percent in healthy persons to 25 percent in immunocompromised patients. Pontiac fever should be treated symptomatically and does not require antibiotic therapy. Control Decontamination of environmental source is of primary importance for preventing infections. Water systems can be treated through superheating or shock chlorination. Facilities with high-risk populations such as transplant centers should regularly monitor and culture water supplies for Legionella. Potable water should be maintained at temperatures not suitable for growth of Legionella species. Cooling towers must receive regular routine maintenance and be filled with sterile water. Immunization has been effective in experimental animals but has not been attempted in humans. SEE ALSO: Gerontology; Infectious Diseases (General);
Pneumonia.
Bibliography. D. W. Fraser, “The Challenges Were Le-
gion,” Lancet Infectious Diseases (v.5/4, 2005); C. GarciaVidal and J. Carratala, “Current Clinical Management of Legionnaire’s Disease,” Expert Review of Anti-Infective Therapy (v.4/5, 2006); R. Marre et al., Legionella (ASM Press, 2002); L. Mulazimoglu and V. L. Yu, “Can Legionnaire’s Disease Be Diagnosed by Clinical Criteria? A Critical Review,” Chest (v.120/1049, 2001). Mary Foote University of Arizona
Leprosy
Leishmaniasis Leishmaniasis is one of the most important parasitic diseases of humans. The cutaneous (skin) and mucocutaneous (skin and membranes) types cause over 2 million new cases and the visceral (organ) types leads to over 500,000 new cases every year. Many tens of millions of individuals suffer from its effects and over 60,000 die every year. There are hundreds of millions of people who live in the poorest parts of the world who are at risk of infection. Leishmaniasis is caused by an intracellular protozoan parasite that is transmitted by the bite of infected sand flies of the phlebotomous (old world) and lutzomyia (new world) species. Reservoirs of these zoonotic parasites include dogs, rodents, and opossums, among others. There are more than a dozen species of leishmania that cause different clinical manifestations and are found in different parts of the world. Cutaneous leishmaniasis is known in different parts of the world as Allepo evil, Delhi boil, Espundia, and Uta. It is caused most commonly by organisms of the Leishmania brazilensis complex (group of related species) in South America, and L. major/L. tropica complexes in Africa and Asia. The disease occurs from days to months after a bite by an infected insect and usually begins with a small nodule at the site of infection. Depending on the species and the individual patient, these lesions may remain small nodules or may form dry or wet well—demarcated painless ulcers with raised borders on exposed body parts. The lesions may vary from small single nodules to multiple diffuse disfiguring ulcerations, and last for variable durations. The mucocutaneous type can be particularly destructive in the oral and nasal mucosa and cause a great deal of discomfort and dysfunction. Diagnosis of cutaneous leishmaniasis may be made by touch smears, scrapings, or culture of exudates of lesions. Serological and polymerase chain reaction (PCR) techniques also exist, but cost limits their use. Depending on the species, most cutaneous lesions heal spontaneously within three to 18 months and treatment may or may not be undertaken. Drugs that are effective for cutaneous and mucocutaneous leishmaniasis include a variety of antimony (Sb) compounds, amphotericin (particularly liposomal), and now miltefosine. There are also several novel topical regimens using paromomycin and imiquomod, among others.
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Visceral leishmaniasis, also known as Kala-Azar and DumDum fever, is most often caused by L. donovani complex (including L. chagasi in the New World, and L. donovani and infantum in the Old World). Classically, the pentad of fever, cachexia, splenomegally, pancytopenia, and hypergammaglobulinemia follows the bite of an infected sand fly and an inconspicuous cutaneous lesion. While there are asymptomatic variants, in untreated patients, emaciation and death occur in up to 90 percent of cases within one to two years. Diagnosis of visceral leishmaniasis is made by tissue smear of splenic, marrow, or node aspirate, or by a variety of tests including rapid commercial, direct agglutination, and urine antigen tests. PCR is the most sensitive and specific but is not always available. Treatment of visceral leishmaniasis, like its severity and resistance pattern, varies with species and geography. Antimony compounds and amphotericin B are first-line treatments with miltefosine, azoles, and others gaining in popularity. The key to prevention and control of both types of leishmaniasis is vector and reservoir control. In-house insecticide spraying, the use of bed nets, and the control of infected dogs are all effective methods. There is a great deal of research that needs to be done to better identify cost-effective means of diagnosing, treating leishmaniasis, and controlling the insect vector. New prospects for a leishmaniasis vaccine hold promise for reducing the impact of this disease in the next decades. SEE ALSO: Parasitic Diseases. Bibliography. C. R. Davies, et al., “Leishmaniasis: New
Approaches to Disease Control,” British Medical Journal (v.326, 2003); D. L. Heyman, ed., Control of Communicable Disease Manual, 18th ed. (American Public Health Association, 2004). Barry Pakes University of Toronto
Leprosy Leprosy, also known as Hansen’s Disease, is a chronic infection caused by the slow growing bacillus Mycobacterium leprae. Leprosy is a disfiguring disease
1010 Lesbian that commonly affects the skin, peripheral nerves, and mucous membranes, but may have a wide spectrum of clinical presentations. The mild end of the spectrum, tuberculoid leprosy, consists of a small number of well demarcated, hypopigmented skin lesions with potential associated damage to near by peripheral nerves. Lepromatous leprosy, at the severe end of the spectrum, is defined by multiple skin nodules and plaques that are full of M. leprae, dermal infiltration of the hands, feet, and face, and distal peripheral neuropathies. Borderline leprosy is considered in the middle of the severity spectrum and it may either revert to tuberculoid disease or worsen to become lepromatous. About half of all individuals with leprosy have a history of close contact with another infected person, generally a household contact with lepromatous or borderline disease. Tuberculoid leprosy is not considered to be contagious. It is thought that the bacterium is transmitted via nasal droplets. However, a significant number of patients do not have a history of exposure to a known or suspected case, suggesting other means of transmission. It has been suggested that the organism may be transmitted via contaminated soil or insect vectors. Leprosy has a long incubation period that averages three to seven years and can be longer than 40 years. Leprosy is generally diagnosed clinically and through biopsy of skin lesions and it may be successfully treated through multi-drug therapy. Dapson forms the foundation of any leprosy treatment. Other important components of the multi-drug therapy may include Rifampin, Clofazimine, Ethionamide, Minocycline, Clarithromycin, and Ofloxacin. Leprosy has been a recognized human disease for millennia and was known to civilizations in ancient Egypt, India, and China. Today, the major burden of disease falls in Africa, Asia, and Latin America. In 1991, the World Health Assembly passed a motion calling for the elimination of leprosy as a major public health problem, defined as achieving a prevalence rate of less than one in 10,000, by the year 2000. On a global level, this target was achieved, however, as of 2005, the prevalence rate continues to exceed he stated goal in the countries of Brazil, India, Madagascar, Mozambique, and Nepal. SEE ALSO: Skin Diseases
Bibliography. Centers for Disease Control, “Hanson’s
Disease (Leprosy)” http://www.cdc.gov/ncidod/dbmd/diseaseinfo/hansens_t.htm (cited May 2006); World Health Organization, “Leprosy Today”, http://www.who.int/lep/ en/ (cited May 2006). Shaun K. Morris Independent Scholar
Lesbian From an etymological point of view, lesbianism is a sexual orientation and, according to that, a lesbian is a woman sexually involved with other women. In other words, a lesbian is a female homosexual. Although the definition seems to be clear enough, it is also true that it causes serious difficulties to its theoreticians. For example, it is difficult to determine when a woman can be considered a lesbian. For some experts, it happens once she had a sexual intercourse with other women. For others, after a first experience and maybe, for a few, should be sufficient to feel attraction to other women or even to fall in love with them. And some sexologists are definitely uncertain about cases where there is no conviction or where a lesbian experience is just a challenge or a new way of exploring one’s own intimacy. Those are too many nuances, with no concluding answers so far. In the meantime, we can affirm that “to be a lesbian” is much more than just a sexual orientation, practice, or preference. In fact, in the widest sense of the word, a lesbian is a female who is emotionally, romantically, or sexually involved, somehow, only with other women. It can even be applied to women who feel some kind of aesthetic attraction to other women. Once lesbianism became more visible, it was described as an inversion—that is what Sigmund Freud affirms—a deviation, a worrying medical condition, a biological or psychological disorder. And certainly for some main religions, lesbianism is just a sexual perversion. In the last few years, some genetic studies attempted to look at female homosexuality from a scientific point of view, but the results have been far from being satisfactory. The term lesbian is not new. It derives from Lesbos, a Greek island in the eastern Aegean Sea, inhabited
by Amazons, the most famous female warrior group. Nevertheless, given the male dominance in Greek culture, it is not surprising that references to female homosexual behavior are rather rare. The original Greek word for female homosexual was tribas (that is why many sexologists use it as a synonym of lesbianism). At the beginning, the term was used to refer to female sexual freedom and licentiousness; however, it gradually became a simple term to designate women sexually or emotionally involved with other women. This semantic evolution of the term was possible thanks to the fame of a lyric poetess, Sappho, born in a local aristocratic family and responsible for a school only for girls called “House of the Muses” (a school of music and poetry), where she supposedly had sexual experiences with some of her pupils to whom she dedicated her passionate verses. Some sources claimed that her relationships were merely platonic. Sappho was a symbol of lesbianism to the extent that another term to refer to lesbianism is the eponym Sapphism. Most of Sappho’s pupils were young, and for that reason, there is a specific concept to define this kind of relationship: gynerasty, which is the female equivalent to male pederasty. At that time, gynerasty had to do with a way of understanding pedagogy and its dimensions. In other cultures, such as China and ancient Arabia, women were supposed to have relationships with other women, but those experiences are not reported in a reliable way. Among Athenians, it was openly known that Spartan women used to fall in love with young girls and Plutarch illustrates in a very convincing way the everyday life of Lacedaemonian women who used to choose young girls as objects of their erotic desires. There is another type of lesbianism in our current times, or at least a hidden dimension of it, which is not totally recorded. Even so, it is well known that among some African people, such as the Nuer, an infertile woman can marry another woman, usually younger than she and able to bear children. In that way, the infertile woman plays a male role—she will be the father of the child—and the other one will be the mother. The only role of a man in that relationship is to impregnate the wife. Behavioral Organization of Lesbians Concerning the role-play or behavioral organization of a lesbian relationship, it was commonly believed that it followed heterosexual models, but this is the
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heterosexual interpretation. Certainly, some roles of power are evident in lesbian relationships, but there is no previous distribution or attribution of a male or female role. There are some recorded cases of mythical lesbian couples where one of them plays the polygamous male, sometimes dressing in mannish clothes. Nevertheless, the sexual expression of lesbianism depends, as in the rest of human sexual relationships, on the context and personal implications. The spectrum of lesbian practices is extremely wide and we cannot generalize. According to their behavior or appearance, the classification offers a diversification of concepts: a dyke or a bulldyke is a woman who exhibits a traditionally male look or behavior. The opposite of butch is femme, who, traditionally, is the member of the couple who exhibits female attributes. A stone butch is a woman who demands absolute submission from her partners, but who never allows her partners to reciprocate the sexual relationship. History and Social Visibility Probably because the phenomenon of the lesbian practices is invisible and even nonexistent in social terms, it has never been illegal, in contrast to male homosexuality, which used to be punished and often condemned by the main religions of the world. However, that same religious discourse is not explicit about lesbian behavior. Plato, in his texts about sexual orientation, dedicates just one sentence to lesbianism. Sigmund Freud, in his work Three Essays on the Theory of Sexuality (1905) referred to lesbianism as if it were an inversion, where a lesbian was a woman having sexual male attributes. That vision has its origin in the ideas of Magnus Hirschfeld, who in the 19th century popularized the theory of a lesbian as a “third sex” within a framework of a sexual disorder. Although Freud’s or Hirschfeld’s beliefs were widely rejected, that figure of the third sex starts to crystallize because theories of identities’ constructions affirm that there are as many sexual identities as sexual preferences, practices, or orientations. Sexual identity becomes a subjective category, or even a cultural category, where personal and cultural implications are involved and that goes beyond the historical classification where only heterosexuality was the admitted norm and the rest of the options just a deviation of that norm.
1012 Lesotho Statistics In terms of percentage, and according to a study by the National Center for Health Research (2002), the data show that 4.4 percent of women between 15 and 44 admitted to having at least one sexual relationship with other woman in the previous 12 months, and 11 percent admitted to having had some sexual intercourse with other women at least once in their lives. The general estimations are that lesbians are between 10 to 12 percent of the total female population. SEE ALSO: Bisexual; Heterosexual; Homosexual. Bibliography. Ruth Allison, Lesbianism: Its Secrets
and Practices (Medco, 1967); Claude Kulkarni, Lesbians and Lesbianisms: A Post-Jungian Perspective (Routledge, 1997). Natalia Fernandez Diaz Independent Scholar
Lesotho Lesotho is a landlocked enclave of South Africa that until 1966 was the British colony of Basoutoland. It is the only independent country in the world that lays entirely about 1000 m (3300 ft), and about 80 percent lays above 1800 m (5900 ft). Lesotho’s main export is water, with the Lesotho Highlands Water Project designed to store water from the Orange River and deliver it to Johannesburg, South Africa. The country is deeply connected with South Africa, with much of its money coming in the form of remittances from Basotho working in South African mines. The population is 2,125,000 and growing almost imperceptibly at 0.144 percent annually. The birth rate and the death rate are almost equal, at 24.72 births per 1,000 and 22.49 deaths per 1,000. Median age is 21.1 years. Life expectancy, which was at about 60 years in the early 1990s, has dropped to 40.73 years for males and 39.18 years for females. Gross national income is $960, with 36 percent of the population living on less than $1 a day. Only 18 percent of the population lives in urban areas. Eighty-six percent of the working-age population works in agriculture; 35 percent of working-age males cross the border to work in nearby
South African mines. Remittances from these workers are critical to the national economy. In part due to the high terrain, Lesotho is largely free of malaria and other diseases. Some rural areas have a high rate of rabies, meningitis, and measles. AIDS and tuberculosis are Lesotho’s biggest health problems, blotting out almost all others. At 31 percent, the country has the second-highest adult prevalence rate of AIDS in the world, next to Swaziland. About 270,000 Basotho are estimated to be infected. The tuberculosis rate is also staggeringly high, with 11,454 new cases diagnoses in a single year. A large number of cases are multi- or extensively-drug resistant. Many more cases of go un- diagnosed, The leading causes of death in Lesotho are pulmonary tuberculosis (30.6 percent), pneumonia (28.7 percent), HIV/AIDS (8.9 percent) and pneumonconiosis with tuberculosis (6.4 percent). In all, the World Health Organization believes that HIV is implicated in 68 percent of all morbidity and mortality. While AIDS is the focus of the medical community, the kingdom’s Ministry of Health notes that non-communicable diseases like diabetes, cancers, hypertension, accidents and psychiatric illnesses also take a toll on Basotho. Child mortality rates are up from 1990 levels, now standing at 102 deaths per 1,000 for infants younger than one, and 132 deaths per 1,000 for children aged 1-5 years. Immunizations rates hover around 80 percent. There are 150,000 orphans in Lesotho, most of them from the AIDS epidemic. Although the Ministry of Health notes that there is little in the way of a social network to replace these children’s family, 95 percent of orphans are enrolled in school. One-fourth of Basotho marry before the age of 18. Rape and other sexual violence against girls is common. Females of all ages are at risk for contracting AIDS, with 150,000 women already infected. Only 37 percent use birth control, and the total fertility rate is 3.21 children per woman. Ninety percent of pregnant women receive some prenatal care, but only 55 percent have a trained attendant during childbirth. This contributes to a high maternal mortality rate, with 550 deaths per 100,000 live births. The Ministry of Health coordinates the kingdom’s medical facilities. Lesotho has a four-tier system, beginning with small health posts, to health centres, then filter clinics (which serve as mini-hospitals), and finally, a network of district hospitals. There is also a
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leprosy hospital, a specialized AIDS clinic, and a psychiatric hospital. In 2003, there were 89 physicians and just over 1,000 nurses. The government spends $41.60 per capita on health care each year. See also: AIDS; Healthcare, Africa. Bibliography. Ministry of Health and Social Welfare,
Kingdom of Lesotho, “National Health and Disease”. http:// www.health.gov.ls/info/epitomology.php (cited June 2007); World Health Organization, “A Guide to Statistical Information at WHO,” http://www.who.int/whosis/en/index. html (cited June 2007; UNAIDS: The Joint United Nations Programme on HIV/AIDS, “Lesotho,” http://www.unaids. org/en/Regions_Countries/Countries/lesotho.asp (cited June 2007); UNICEF, “UNICEF—Lesotho—Statistics,” http://www.unicef.org/infobycountry/lesotho_statistics. html (cited June 2007). Heather K. Michon Independent Scholar
Leukemia Leukemia is a cancer of the blood that causes the cell lines in bone marrow to grow abnormally. This term refers mostly to white blood cells (leukocytes) and is used rarely in reference to red blood cells and platelets. White blood cells are the cells in the blood and tissues that protect animals from infection. With each injury or infection, these cells create a response to help protect the body from invading pathogens. Without them, a person has difficulty surviving. Overall, leukemia is divided into four broad categories. First, it is divided into myelogenous and lymphocytic, which are the two major different types of white blood cells. Myelogenous cells differentiate into many other types of white blood cells including neutrophils, eosinophils, and macrophages. Lymphocytic cells differentiate into B lymphocytes and T lymphocytes. Each of these two groups is further subdivided into acute and chronic diseases. An acute leukemia is normally a rapidly progressing disease that is caused by the overproduction of immature cells. A chronic leukemia has a more gradual onset and is caused by the overproduction of mature cells. A chronic leukemia can be-
Human cells with acute myelocytic leukemia (AML) in the pericardial fluid, shown with an esterase stain at 400x.
come an acute leukemia, but the reverse will not happen. An acute leukemia is generally more ominous, especially when it is preceded by a chronic leukemia. Death can occur within months after the onset of an acute leukemia if treatment is not sought. Approximately 70 percent of leukemias occur in adults and are mostly chronic lymphocytic leukemia and acute mylogenous leukemia. The remaining 30 percent is mostly acute lymphoblastic leukemia in children. All three groups of blood products—white blood cells, red blood cells, and platelets—are produced in the bone marrow. When the white blood cells outgrow the red blood cells and platelets, the other two groups are not able to produce their respective blood products because of the lack of room in the bone marrow. Thus, the signs and symptoms of leukemia reflect the shift of cells in the bone marrow, which normally allows growth of red blood cells, platelets, and white
1014 Leukemia blood cells to the uncontrolled growth of one line of cells. Many people with leukemia will present with weakness, fatigue, bruising, infection, and abnormal bleeding such as nose bleeds or around the gums. The fatigue is from the decreased number of red blood cells, also known as anemia. The bleeding and bruising is from a decreased number of platelets, which help the blood to clot. The increased number of infections is due to the dysfunctional white blood cells. Although there are more white blood cells than normal in the blood in leukemias, they do not function like a normal protective cell. Other nonspecific symptoms include fever, night sweats, and loss of appetite. Diagnosis of leukemia is usually made from a complete blood count (CBC), a smear of the blood onto a microscope slide (peripheral smear), a bone marrow biopsy plated onto microscope slides, and genetic testing for cell markers (CD or cluster of differentiation) or translocation. Translocation is the joining of two halves of two different chromosomes that do not belong together and is usually determined by a process call fluorescent in situ hybridization (FISH). FISH is completed by looking at the 23 sets of human chromosomes and attaching a fluorescent marker to genes that are found on certain chromosomes. If the two markers end up on the same set of chromosomes, then there was no translocation. However, if the markers end up on different sets of chromosomes, then translocation is present. Examples of translocation would be the merging of a part of chromosome 9 with a part of chromosome 22 in acute lymphocytic leukemia and chronic mylogenous leukemia or the joining of part of chromosome 15 with part of chromosome 17 in acute myelocytic leukemia. Acute Lymphocytic Leukemia Acute lymphocytic leukemia (ALL) is considered a disease of childhood, although it can appear at any time in life and approximately one-third to one-fifth of people diagnosed with this disease are adults. The remission rate for children is approximately 80 percent, while the remission rate for adults is only 30 to 40 percent. Children and adolescents often have pain in their long bones, such as the humerus and femur secondary to outer bone involvement. This disease is also known as acute lymphoblastic leukemia because the disease is comprised of immature cells or blasts; therefore, lymphoblastic means immature white
blood cells. As stated above, lymphocytes are made up of two groups, B lymphocytes and T lymphocytes. Approximately 80 percent of ALL is caused by B lymphocytes and the rest by T lymphocytes. This disease is classified into three groups, with the first group, L1, accounting for 85 to 89 percent of ALL in children. L1 has small immature lymphocytes with a small amount of cytoplasm (the cell material outside of the nucleus), condensed nuclear material, and multiple nucleoli (small round areas within the nucleus). L2 has a moderate amount of cytoplasm, dispersed nuclear matter, and multiple nucleoli. L3 has basic staining granules in the cytoplasm and multiple cavities within the cytoplasm. L3 accounts for less than 1 percent of ALL in children. Multiple translocations can happen with ALL, and include chromosomes 9 and 22, 1 and 19, 4 and 11, 8 and 14, and 1 and 14. Treatment includes vincristine, prednisone, asparaginase, methotrexate, and doxorubicin or daunrubicin. Cylophosphamide is added for adults. Chronic Lymphocytic Leukemia Chronic lymphocytic leukemia (CLL) is a disease of older individuals, and most cases are found in people 50 years or older. Sometimes, this disease produces almost no symptoms and is found incidentally by an increase in lymphocytes >10,000/µL on routine blood counts or is found after the person notices nontender, enlarged lymph nodes. CLL is subdivided into two different categories: the slow form and the insidious form. There is also a staging scale for CLL most commonly used in the United States called the Rai system, which subdivides the disease into stages 0–IV. This system is based on the number of red blood cells and platelets, and then lymph node, spleen, liver, and bone marrow involvement. Stage 0 involves lymph nodes only and has a median survival time of 150 months. Stages I and II include lymph node infiltration and the enlargement of organs. Stage I has a median survival rate of 101 months and Stage II has a median survival rate of 71 months. Stages III and IV have lymph node involvement, organ enlargement, and the addition of low red blood cell counts and low platelet counts with a mean survival of nine months. Common chromosomal changes seen in CLL include deletion of portion of chromosome 11, 13, or 17, or three chromosomes (trisomy) of chromosomes 3, 12, or 16. Treatment for CLL depends on the degree of
Leukemia
the disease. Many people can live with CLL for years with just basic monitoring of routine blood counts and physician visits. If treatment is chosen, the most common form is chemotherapy, which includes chemotherapeutic agents such as fludarabine, chlorambucil, pentostatin, and cyclophosphamide. Three other options are left after chemotherapy and are not normally used unless chemotherapy by itself is failing. These options are immunotherapy, bone marrow transplant, and stem cell transplant. Immunotherapy includes the drugs rituximab and alemtuzumab, which are two drugs that help attack foreign cells in the body. Stem cell transplant, such as bone marrow transplant, is rarely used in this disease. Acute Myelocytic Leukemia Acute myelocytic leukemia (AML) is divided into eight categories based on the FAB classification scheme. FAB M0 is acute myeloid leukemia with minimal differentiation. FAB M1 is acute myeloid leukemia without maturation. FAB M2 is acute myeloid leukemia with maturation, and many of these cells have a chromosome 8 and 21 translocation. FAB M3 is acute promyelocytic leukemia (APL) and is associated with the translocation of chromosomes 15 and 17. FAB M4 is acute myelomonocytic leukemia. FAB M5 is acute monoblastic leukemia with differentiated and poorly differentiated variants. FAB M6 is acute erythroleukemia, which is classified due the fact that there are both immature red blood cells and immature myeloid blood cells being produced. FAB M7 is acute megakaryoblastic leukemia which includes the overproduction of immature platelet stem cells and immature myeloid cells, associated with the translocation of chromosome 1 and 22 when diagnosed in children. All of these subgroups can be divided into risk categories and their survival rates based upon this. The good risk category is composed of translocations of chromosome 8 with 21, 15 with 17, and other abnormalities of chromosome 16 including a deletion of the short arm of the chromosome. The poor risk factor category included only one chromosome 5 or 7, deletion of the short arm of chromosome 5, resistant disease after the initial course of chemotherapy, and no good risk factors. Intermediate risk factors were considered factors placed in neither the good risk factor category nor the poor risk factor category. The five-year survival rates and relapse rates for these three categories was 70 and 33 percent for the
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good category, 48 and 50 percent for the intermediate category, and 15 and 78 percent for the poor risk category, respectively. In general, remission rates are inversely related to age, and the expected remission rate is over 65 percent in those younger than 60 years old. Also, the FAB M3 subtype, or acute promyelocytic leukemia with the 15:17 translocation, is currently considered the most favorably subtype because of the response of the disease to the drug all-trans retinoic acid in combination with other chemotherapy. Other chemotherapeutic agents used in the above leukemias include cytarabine plus daunorubicin or idarubicin or mitoxantrone. Megakaryoblastic leukemia, FAB M7, is one of the rarer subtypes and it also has one of the worst overall outcome rates. Chronic Myelogenous Leukemia Chronic myelogenous leukemia (CML) is the uncontrolled reproduction of maturing mylocetes, most often neutrophils. CML is also commonly found on routine blood tests in approximately 20 to 50 percent of the time. Common presenting symptoms include fatigue, weight loss, excessive sweating, abdominal pain and discomfort, early satiety, and gouty arthritis. The abdominal pain, abdominal discomfort, and early satiety can be secondary to an enlarged spleen and the gouty arthritis is secondary to the overproduction of uric acid, which happens when cells turn over quickly. CML is associated with the “Philadelphia chromosome,” which is the translocation of chromosomes 9 and 22. This disease ranges from a chronically stable disease to an aggressive leukemia; it normally progresses to an acute leukemic state within two years of diagnosis. Treatment options include hematopoietic cell transplantation, chemotherapeutic therapies with tyrosine kinase inhibitors, which are directed specifically toward CML and include imatinib, dasatinib, nilotinib, or other treatments with hydroxyurea, interferon alpha, and busulfan. Imatinib is the treatment of choice in older patients, in those with an aggressive disease, and younger patients without a matching hematopoietic transplant donor. Imatinib has shown to be responsive in 100 percent of chronic phase CML patients, 83 percent of accelerated phase patients, and 43 percent of blastic phase patients. SEE ALSO: Cancer (General); Cancer Alternative Therapy;
Cancer Chemotherapy.
1016 Leukodystrophies Bibliography. Uma H. Athale, et al., “Biology and Out-
come of Childhood Acute Megadaryoblastic Leukemia: A Singe Institution’s Experience,” Blood (v.97/12, 2001); Mark Dambro, “Leukemia,” The 2-Minute Clinical Consult 2007, 15th ed. (STAT!Ref Electronic Medical Library, 2007); Terah Horton and C. Philip Steuber, “Overview of the Presentation and Classification of Acute Lymphoblastic Leukemia in Children,” Up ToDate Patient Information, http://patients.uptodate.com/topic.asp?file=ped_ onco/5958; The Leukemia and Lymphoma Society, “Acute Lymphocytic Leukemia,” http://www.leukemialymphoma.org/all_page?item_id=7049; MayoClinic.com, “Chronic Lymphocytic Leukemia,” http://www.mayoclinic.com/health/chronic-lymphocytic-leukemia/DS00565; Robert S. Negrin and Charles A. Schiffer, “Overview of the Treatment of Chronic Myelogenous Leukemia,” UpToDate Patient Information, http://patients.uptodate. com/topic.asp?file=leukemia/15171; Ching-Hon Pui and William E. Evans, “Acute Lymphoblastic Leukemia,” New England Journal of Medicine (v.339/9, 1998); Angela J. Garner, M.D. Jennifer Goldkamp, M.S. University of Missouri–Kansas City
Leukodystrophies Leukodystrophies are a family of diseases linked by the degeneration of the white matter of the brain. The diseases are mostly genetically transmitted from parent to child. They cause damage to the myelin sheath, which is supposed to protect the nerve cells of the brain, and the diseases are progressive, which means the effects intensify over time. The cells of the myelin sheath are the white matter referred to in the name of the disease and, in being damaged, severely inhibit the ability of brain cells to communicate effectively with each other. The effect of the disease is similar to multiple sclerosis (MS), but the cause is different in that MS results from the body attacking its own immune system. There are 34 different types of leukodystrophy that have so far been identified; these include Pelizaeus Merzbacher disease, Krabbe disease (globoid cell leukodystrophy), monochromatic leukodystro-
phy, and Canavan disease. The ways in which the disease may be detected include genetic testing, blood and urine analysis, computed tomography (CT), and magnetic resonance imaging (MRI) testing, depending on the nature of the disease. Awareness of medical history will indicate to medical staff the need for such testing, which is otherwise likely to be specialized and expensive. The range of symptoms also varies considerably, from bowel dysfunction to developmental delay, seizure, and extreme irritability. Psychosis may be common in various forms of the disease and testing may be indicated in the event of severe behavioral disturbances. Many, but not all, forms of leukodystrophy have no known cures and the only treatment is to ameliorate symptoms, which vary depending on the specific nature of the disease. The symptoms can be distressing both for the patients and for their parents. Those forms of disease that can be tested for genetically may be accompanied in countries with high levels of medical care by parental counseling. In other cases, pharmaceuticals can limit, slow, and even reverse damage caused to the brain. Timely and accurate medical advice is required to identify when such treatments might be available and effective. Some forms of the disease appear to be receptive to treatment involving stem cell transplants. For example, Krabbe disease patients may benefit from hematopoietic stem cell transplants in the event that the disease is diagnosed at or before the point of birth or else takes an adult-onset form. However, the procedures are complex and much more research into stem cell technology is required to be certain of the effect on patients with this and related types of disease. Such research is currently subject to political and religious debate in some countries. SEE ALSO: Brain Diseases; Genetics. Bibliography. T.M. Hyde, J.C. Ziegler, and D.R. Wein-
berger, “Psychiatric Disturbances in Metachromatic Leukodystrophia. Insights into the Neurobiology of Psychosis,” Archives of Neurology (v.49/4, 1992); The United Leukodystrophobia Foundation (ULF), http://www.ulf.org (cited July 2007). John Walsh Shinawatra University
Liberia
Lewis, Edward B. (1918-2004) Edward B. Lewis was an American geneticist who won the Nobel Prize in Physiology or Medicine in 1995 with his studies on the Drosophila fly which contributed to the foundation of the field of developmental genetics. He shared the Nobel Prize with Eric Wieschaus and Christiane Nüsslein-Volhard. Lewis discovered that a series of master control genes that devise the development of a fly embryo’s body parts. These genes, called bithorax complex, have the same chromosome order of the body parts that they control. Since Lewis’s discovery, the bithorax complex have been found in all other animals, including humans, pointing to a common and ancient genetic development. Lewis was born in Wilkes-Barre, Pennsylvania on May 20, 1918. The son of a watchmaker, Lewis developed a particular interest for nature and wildlife from a very early age. He received his B.A. degree from the University of Minnesota in 1939, where he began to study the Drosophila thanks to his genetics professor C. P. Oliver. Thanks to Oliver’s recommendation, Lewis was accepted as a graduate student at the California Institute of Technology from where he earned his Ph.D. in 1942. His thesis discussed how to detect if two recessive genes were part of the same gene or of two different ones. His conclusions developed the cis-trans test, an important technique for genetic analysis. During the war, Lewis served in the Army Air Force as a meteorologist and oceanographer in the Pacific Theater. Lewis returned to Caltech in 1946 where he lectured and continued his research on the Drosophila. He became professor of biology in 1956 and ten years later he was appointed the Morgan Professor of Biology. In spite of his choice of mainly working on his own, Lewis did not eschew public controversy when, during the 1950s, he publicly took a stand against above-ground nuclear-power tests, denouncing their risks for health. In 1957, he published in Science the results of his research about the risks of leukemia following exposure even to small amounts of radiation. His study caused such a stir that Lewis was summoned before a congressional joint committee on atomic energy. Lewis was active in his scientific researches until his death on July 21, 2004. SEE ALSO: Genetics; Leukemia.
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Bibliography. Howard D. Lipshitz, ed., Genes, Develop-
ment and Cancer: The Life and Work of Edward B. Lewis. (Kulver Academic, 2004). Luca Prono Independent Scholar
Liberia Liberia is located in western Africa, on the North Atlantic coast between Côte d’Ivoire and Sierra Leone. It is Africa’s oldest republic, having been settled by freed American slaves in the 1820s and declared an independent country in 1847. Today, Liberia is reeling from the aftermath of two civil wars, lasting from 1989 to 1996 and again from 1999 to 2003. The election of Ellen Johnson-Sirleaf in fall 2005 seems to mark the beginning of a more peaceful era for the country, but sporadic fighting continues, and the work of rebuilding is massive. The population is estimated at 3 million people, with an annual growth rate of 4.91 percent—driven largely by the return of refugees displaced by the wars. There are now 27.4 migrants per 1,000 residents, 44.8 births per 1,000, and 23.1 deaths per 1,000. Almost half the population lives in urban areas. Population density is 29 people per square kilometer. Poverty is nearly universal. The collapse of the economy has left 85 percent of the labor force out of work, the highest unemployment rate in the world. Per capita income is $140 annually. About 80 percent of the population live on less than $1 a day. One in six Liberians depends on humanitarian food aid to get by. ����������� Life expectancy at birth is 39 years for males and 44 years for females, with healthy life expectancy at 36 years for men and 37 years for women. Infant mortality is 156 deaths per 1,000 live births. For children between the ages of 1 and 5, the mortality rate is 230 deaths per 1,000. Maternal mortality is 760 deaths per 100,000 live births Warfare displaced 300,000 people in the 1990s, the majority of them women and children. Almost 40 percent of children under the age of 5 show stunted growth (a bellwether of malnutrition), another 26 percent are underweight, and 6 percent are acutely malnourished. There are an estimated 230,000 orphans under the age of 17. Children in some areas have been
1018 Libya dragooned into militias. Schools and immunization programs have virtually ceased to function. The fertility rate for Liberian women is high, with the average woman giving birth to six children during her reproductive life; only 10 percent use any form of birth control. About 50 percent of births are monitored by a trained attendant. One-half of women polled in a recent survey reported that they had been physically or sexually assaulted by a combatant during the war. Widespread sexual abuse has led to an increase in human immunodeficiency virus (HIV), sexually transmitted diseases, unwanted pregnancies, and induced abortions, especially among refugee women. There have been no reliable statistics on morbidity and mortality in Liberia for many years, but even before the decade of turmoil, the country ranked 43rd out of 46 sub-Saharan countries in mortality rates. Today, only about 25 percent of Liberians have access to clean drinking water or sanitary facilities. Common infectious diseases include bacterial and protozoal diarrhea, malaria, yellow fever, schistosomiasis, Lassa fever, hepatitis A, typhoid, acute respiratory infection, and cholera. The prevalence of HIV/AIDS in the adult population is estimated at 5.9 percent, but may be as high as 20 percent in some urban areas. At least 100,000 people are living with the virus and at least 7,200 have already died from the virus. Tuberculosis has also expanded, with an incidence rate of 310 cases per 100,000 people. The health system is in a state of chaos, with almost all hospitals, clinics, and health posts outside the capital city of Monrovia destroyed during the war. Humanitarian groups are at work in various parts of the country, but the United Nations Children’s Fund (UNICEF) estimates that upward of 70 percent of the population lacks access to healthcare. That situation is expected to improve as the country stabilizes, but it will take a great deal of time to reach all those in need. SEE ALSO: Disease and Poverty; Healthcare, Africa. Bibliography. David McBride, Missions for Science: U.S.
Technology and Medicine in America’s African World (Rutgers University Press, 2006). Heather K. Michon Independent Scholar
Libya This North African country was occupied by the Ottoman Turks from the sixteenth century until 1911, when it was captured by the Italians who called it Libya (or Libia) in 1934, and held it until World War II. It was then under British control (with the French holding Fezzan), and became independent on December 24, 1951, as the United Kingdom of Libya. After a revolution in 1969 it was renamed the Libyan People’s Socialist Arab Jamahiriya. It has a population of 5,673,000 (2006), with 128 doctors and 360 nurses per 100,000 people. Before Italian colonial rule, health care in much of the country was extremely limited, although Arab surgeons since medieval times were known to have used the works of the surgeon Avicenna (980-1037). During Italian rule, health care dramatically improved for the European population and the local elite, with the Italians equipping a number of European-style hospitals in the major cities: Tripoli, Cyrene and Benghazi, the municipal hospital in Benghazi located close to Benghazi Harbor. However outside these coastal cities, much of the country remained extremely poor with a number of traveling doctors such as the Italian aristocrat Alberto Denti di Pirajno, who became famous from his best-selling book, A Cure for Serpents (1955). The health care service was also devastated during World War II. After World War II, the country was controlled by the British until 1951 when the United Kingdom of Libya was established. It tried to improve the provision of health care, with the establishment of the Libyan Red Crescent in 1957. During the 1960s the discovery of oil brought much wealth to the country, and this in turn led to the government spending more on infrastructure, including new hospitals. On September 1, 1969, Colonel Muammar al Qadhafi took power, deposing King Idris. One of the major planks of the new government was to continue to improve the medical services throughout the country, with World Health Day being commemorated each year. In 1969 there were 733 doctors and 62 dentists. By 1978 there were 3,350 doctors and 277 dentists, with the number of nurses in the country having gone up from 1,680 to 4,705 in the same period, pharmacists from 68 to 538, and hospital beds from 5,646 to 13,347. By 1985 there were 5,450 doc-
Liechtenstein
tors and dentists in the country. Furthermore in 1975 only six percent of doctors in the country were Libyan citizens, whereas by 1985 this figure had risen to a third. In 1978 the government joined a world campaign to reduce hypertension. The Faculty of Medicine at Alfateh Medical University, in Tripoli, remains the main medical research center in the country; with some research work into cancer and other conditions being undertaken at Benghazi Hospital. The foreign embargo on trade with Libya from 1993 until 2004 led to a decline in the hospital care as the country was unable to buy new medical equipment and pharmaceutical products. However with the lifting of all sanctions, the health care system was considerably improved. Malaria still exits in south-west of the country, with the improvements in the provision of water from the 1960s eliminating many of the problems of cholera and dysentery which existed during the Italian period. Typhoid, paratyphoid, infectious hepatitis, rabies and meningitis cases are regularly seen at Libyan hospitals, with some cases of leprosy still reported. However trachoma has been largely eliminated during the 1970s. All foreigners in Libya are treated free in hospitals for accidents and emergencies. SEE ALSO: Healthcare, Africa; Meningitis; Typhoid. Bibliography. Aghil M. Barbar, Health care in Libya: an
Introductory Survey (Vance Bibliographies, 1978); Alberto Denti di Pirajno, A Cure for Serpents (Andre Deutsch, 1955). Justin Corfield Geelong Grammar School, Australia
Liechtenstein The German-speaking Principality of Liechtenstein is affluent and homogeneous. The per capita income of $25,000 makes Liechtenstein the 40th richest country in the world, Economic indicators demonstrate the health of the economy, which is growing at a rate of 11 percent. Both inflation (1 percent) and unemployment (1.3 percent) are well under control. This prosperity is due in large part to the low tax base
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that attracts companies from around the world. In fact, Liechtenstein is the only country in the world with more registered businesses than people. Nearly a third of income is generated by so-called letterbox companies that have only a nominal physical presence in the country. Of 29,500 individuals in the work force, 13,900 regularly commute from Austria, Switzerland, and Germany to work in Liechtenstein. No interest is charged on housing loans, making housing more affordable throughout the country. Many social indicators are unavailable for Liechtenstein, but the standard of living is equivalent of that in other European countries. Health insurance is mandatory in Liechtenstein, but residents have a wide choice of health care providers. The elderly, the disabled, and survivors are covered through social insurance and a mandatory occupational pension system. Workers and employers contribute to the social security fund, and those contributions are supplemented by government subsidies. The Old Age, Survivor, and Disability Institute is charged with administering the program. The government is responsible for one-fifth of the total budget on health. There are 64 physicians and 26 dentists who serve the population of 33,986 people. Only one hospital exists, and many Liechtensteiners seek medical attention in other European countries. The population enjoys a life expectancy of 79.68 years, and females generally outlive males by more than seven years. A hundred percent of Liechtensteiners over the age of ten are able to read and write. Nearly 90 percent of Liechtenstein children complete primary school, and 70.2 percent of young people are enrolled in school at the secondary level. The women’s movement in Liechtenstein has aroused great interest in the role of males in family life, and the government encourages employers to create more part-time positions for men to give them more time with their families. The Office of Gender Equality and the project group Images of Man focuses on the physical and psychological health of both sexes. Women give birth in Liechtenstein at a rate of 1.51 children each. More than threefourths of the population is Roman Catholic; however in 2005 voters vetoed a church-led referendum that would have made abortion and all methods of artificial birth control illegal. Liechtensteiners also upheld their right to sign living wills to prevent their being kept alive only through medical technology.
1020 Lithuania Between 2000 and 2004, infant mortality dropped from 5.3 to 4.4 deaths per 1,000 live births. Current infant mortality is reported at 4.74 deaths per 1,000 live births. Male infants (6.24 deaths per 1,000 live births) are almost twice as likely as female infants (3.04) to die. No HIV/AIDS prevalence rates are available for Liechtenstein, but incidences are low. Preventive health care is an important element of the health system in Liechtenstein, and a regular prevention schedule is published with recommendations for checkups at periodic intervals beginning at birth and continuing into old age. SEE ALSO: Healthcare, Europe. Bibliography. Spencer Di Scala, Twentieth Century
Europe: Politics, Society, Culture (McGraw-Hill, 2004); Martin A. Levin and Martin Shapiro, eds., Transatlantic Policymaking in an Age of Austerity: Diversity and Drift (Georgetown University Press, 2004); Jeremy Rifkin, The European Dream: How Europe’s Vision of the Future Is Quietly Eclipsing the American Dream (Jeremy P. Tarcher/Penguin, 2004); Manfred Schlapp, This Is Liechtenstein (Seewald, 1980); Peter Taylor-Gooby, New Risks, New Welfare: The Transformation of the European Welfare State (Oxford University Press, 2004). Elizabeth R. Purdy, Ph.D. Independent Scholar
Lithuania With a per capita income of $13,700, the eastern European nation of Lithuania ranks 70th in world incomes. The government has successfully privatized most state-owned utilities, and 80 percent of businesses are now privatized. The economy is growing (7.5 percent) and unemployment (4.8 percent) and inflation (2.7 percent) are under control. Although the Lithuanian economy is diversified, a fifth of the population is engaged in the agricultural sector. By 2004 estimates, 252.2 million Lithuanians survive on less than $1 a day. Income disparities continue to exist, and Lithuania’s Gini Coefficient is 31.9. More than a fourth (25.6 percent) of wealth is in the hands of the richest segment of the population, leaving the poorest
ten percent with 3.1 percent. Ties with the West have intensified, particularly since Lithuania joined the European Union and NATO in 2004. The UNDP Human Development Reports classify Lithuania’s standard of living as the 41st highest in the world. Health care is easily accessible for most Lithuanians. The government’s responsibility for direct health care derives from the social insurance program that covers the elderly, the disabled, survivors, and the economically disadvantaged. Since 2000, workers have been given the option of placing 2.5 percent of total incomes in individual retirement accounts. Social security is financed by contributions from employees (2.5 percent of wage), employers (23.4 percent of payroll), and government subsidies. Maternity benefits provide new mothers on leave with at least one-fourth of their salaries for up to 70 calendar days before birth and 56 calendar days after the expected birth of a child. Either parent is entitled to a year’s leave with compensation equaling at least 60 percent of wages. Low-income families are provided with family allowances and free medical care. The Lithuanian government spends 12 percent of the total budget on health. More than 6 percent of the Gross Domestic Product (GDP) is used to fund health programs, and approximately $754 (international dollars) per capita is earmarked for health. Government funding accounts for 76.0 percent of all health expenditures, and 74.6 percent of that amount is used to subsidize social security. The private sector provides 24 percent of health costs, and 96.60 percent of private funding is derived from out-of-pocket expenses. There are 3.96 physicians, 7.62 nurses, 0.33 midwives, 0.69 dentists, and 0.69 pharmacists per 1,000/ population in Lithuania. The population of 3,585,906 experiences a life expectancy of 74.2 years, and females generally outlive males by more than 10 years. Literacy is universal, and virtually all of the relevant population regularly attends primary and secondary school. Lithuania has the fifth lowest fertility rate in the world; and women give birth to 1.2 children each. Trained attendants are present at all births, and the adjusted maternal mortality rate is 13 deaths per 100,000 live births. Infant mortality is currently reported at 6.78 deaths per 1,000 live births. Between 1990 and 2004, infant mortality dropped from 10 to eight deaths per 1,000 live births, and mortality rates for children under the age of five decreased from 13 to eight deaths per 1,000
Lithuania
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The Lithuanian government’s responsibility for direct health care derives from the social insurance program that covers the elderly, the disabled, survivors, and the economically disadvantaged.
live births. Overall, Lithuanian children are healthy, but four percent of infants are underweight at birth. The government subsidizes all required infant immunizations, and rates are predictably high. Only one percent of infants fail to be immunized against tuberculosis and two percent against measles. Ninety-four percent of infants receive diphtheria, pertussis, and tetanus (DPT1 and DPT3) and Hepatitis B inoculations, and 90 percent are immunized against polio. However, only 34 percent are immunized against Haemophilus influenzae type B. The environment poses a threat to the health of some Lithuanians, and the government continues to deal with the aftermath of air, water, and soil polluted with petroleum and other chemicals by Soviet military troops. At times, air pollution is so extensive in Lithuania that it blankets a third of the country. Two reactors at the Ignalina nuclear power plant that are similar to the one used in Chernobyl in the Ukraine may pose a future health threat to Lithuanians. HIV/AIDS is under control. Some 1,300 people are currently living with the disease, and less than 200 have died. As in much
of the developed world, a rapidly aging population is straining government budgets, requiring care for dementia, depression, cancer, cardiovascular diseases, arthritis, and other conditions that disproportionately affect people as they age. Government officials are endeavoring to improve the health of this population through the Health for Everyone in the 21st Century initiative, which promotes healthy and active lifestyles. In general, preventive health is considered a major priority in Lithuania, and special programs target infants, children, pregnant women, and new mothers. SEE ALSO: Environmental Health; Healthcare, Europe. Bibliography. Kevin Hillstrom and Laurie Collier Hill-
strom, Europe: A Continental Overview of Environmental Issues (ABC-CLIO, 2003); Martin A. Levin and Martin Shapiro, eds., Transatlantic Policymaking in an Age of Austerity: Diversity and Drift (Georgetown University Press, 2004). Elizabeth R. Purdy, Ph.D. Independent Scholar
1022 Liver Cancer
Liver Cancer Primary cancers of the liver include hepatocellular carcinoma (HCC), cholangiocarcinoma, angiosarcoma, and hepatoblastoma. Of these cancers, HCC is the most common, representing the fifth most frequent cancer worldwide and the third most lethal, with a five-year survival rate of only 8 to 9 percent. The prognosis for patients is worsened by cancer-associated liver dysfunction: as many patients die from liver failure as from tumor progression. Although HCC is most prevalent in eastern Asia and sub-Saharan Africa, where the incidence of hepatitis B virus (HBV) infection is high, the number of HCC diagnoses in the United States and other Western countries has been rising steadily since the 1980s. While the most common cause of HCC is chronic HBV infection, any type of damage to the liver can create a precancerous condition. Liver damage leads to a condition called cirrhosis, defined by fibrotic scarring and nodular regeneration of the liver cells (hepatocytes). The molecular changes that mediate transition from cirrhosis to malignant tumor development have not been fully established; however, hyperactivation of known oncogenes such as Ras and loss of tumor suppressor genes such as p53 have been implicated. Examples of liver damage leading to cirrhosis include chronic viral infection (by hepatitis B or hepatitis C viruses), aflatoxin exposure, alcohol consumption, and less commonly, iron overload (hemochromatosis), steroid abuse, and smoking. Other risk factors for HCC include sex (men are more frequently affected than women), age (increased age means increased risk, except in areas where patients are infected with HBV from birth), and a family history of HCC. Viral infection of the liver is by far the greatest risk factor for liver cancer. Areas where HBV infection is endemic, such as eastern Asia and sub-Saharan Africa, can have HCC incidences as high as 120 cases per 100,000 people, in contrast to Western countries where the incidence may be as low as two cases per 100,000. The geographic distribution of HCV infection overlaps with HBV, increasing the population risk. The hepatitis B virus is a partially double-stranded DNA virus largely transmitted through exposure to infected bodily fluids. Acute infection with HBV can present with symptoms of vomiting, jaundice, and liver inflammation. This initial infection can be resolved, or it can go on to develop
a chronic infection. This leads to chronic inflammation of the liver, cirrhosis, and eventually liver cancer, usually decades after the initial infection. The hepatitis C virus is a different virus from HBV, carries an RNA genome and acute infection with HCV is asymptomatic. However, HCV develops into a chronic infection more frequently than HBV, and causes liver cancer either by creating a precancerous cirrhotic liver or through the infection itself. Currently, HCV infection is the most common cause of liver cancer in Japan and Europe, and is thought to be responsible for the recent increase in HCC incidence in the United States. Aflatoxins, another risk factor for HCC, are naturally occurring toxins produced by the Aspergillus fungus, which grows on crops such as peanuts, corn, soybeans, almonds, and pistachios. Aflatoxins are DNA-damaging agents that mutate genes such as p53 that regulate cell proliferation, and these genetic changes are thought to be responsible for aflatoxinmediated tumorigenesis. Long-term aflatoxin exposure increases the risk for HCC, although not as much as HBV infection, and the combination of aflatoxin exposure and HBV infection increases HCC risk synergistically. In the United States, foodstuffs are screened for Aspergillus contamination and aflatoxin exposure is maintained at a minimal level. On the other hand, alcohol consumption remains the most common risk factor in the United States for HCC. Prolonged alcohol abuse damages the liver and leads to cirrhosis. There are currently no good screening methods available to identify liver cancer in its early stages. High serum levels of alpha fetoprotein (AFP) are seen in patients with liver cancer, and also in patients with chronic liver disease. Liver cancer is diagnosed by imaging the liver for tumors, using techniques such as computed tomography (CT) scan or magnetic resonance imaging (MRI), but diagnosis is only possible when the tumor has already grown to a significant size. Alternatively, physicians can biopsy the liver by inserting a fine needle into the organ and removing a small amount of tissue. Pathologists can then examine the tissue for malignant growth. There are also very limited treatment options for patients with liver cancer. Surgical resection of the tumor is the only curative treatment, but surgery is only available during the early stages when the disease is difficult to detect, and only when the cancer presents as a defined mass. Other treatment options include radiation
Liver Diseases (General)
and chemotherapy, which have been shown to decrease tumor mass. Tumor ablation techniques, which use a fine needle to target the tumor and inject toxic chemicals or cold substances to freeze the tumor, have also been shown to reduce tumor burden. However, these options do not fully remove the tumor, and it is unclear whether these treatments can significantly prolong patient survival. The best way to avoid liver cancer-related mortality is therefore prevention of the cancer itself. Because there is such a high correlation between hepatitis B virus infection and HCC, current efforts to reduce the incidence of HCC worldwide focus on vaccination programs in areas where HBV is endemic to the population. In Taiwan, where hospitals began vaccinating children against HBV from birth or early childhood, studies have shown a 75 percent decrease in HCC incidence. To date, there are no vaccines for HCV. The liver is also a frequent site of metastases for other cancers. SEE ALSO: Cancer (General); Cirrhosis; Hemochromato-
sis; Hepatitis; Hepatitis C; Liver Diseases (General).
Bibliography. P. A. Farazi and R. A. DePinho, Hepato-
cellular Carcinoma Pathogenesis: From Genes to Environment. (Nature Reviews Cancer, 2006); Donald Kufe, et al., eds., Cancer Medicine, 6th ed. (Hamilton, 2003); Keith Stuart, “Hepatic Carcinoma, Primary,” www.emedicine. com (cited ); U.S. National Institutes of Health, “SEER Surveillance Epidemiology and End Results,” seer.cancer.gov (cited July 2007). Cindy Chang Cold Spring Harbor Laboratory SUNY Stony Brook
Liver Diseases (General) The liver is a vital organ in the body that plays a central role in human health including detoxification of ingested substances, lipid metabolism, and synthesis of blood clotting factors and important body proteins. The cells of the liver, hepatocytes, house thousands of chemical reactions every second in order to perform myriad functions that contribute to human health. As a central player in human physiology, the liver is involved
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in multiple interrelated body systems, and is subject to a variety of insults and mechanisms of disease. Evaluation of Liver Disease Liver disease is classified according to the duration of abnormalities as either acute (<six months) or chronic (>six months). Evaluation of subjects with liver disease starts with basic laboratory blood tests. Elevation of molecules contained within the liver cell, the serum aminotransferases (AST and ALT) indicate injury to hepatocytes. Secondary to some insult, there is injury to the hepatocyte and these specific molecules can leak from the hepatocytes into the blood. The level of elevation in AST and ALT as well as their ratio may give some indication as to the possible inciting cause. For example, the ratio of blood AST to ALT is typically greater than 2 in alcoholic liver disease. In viral hepatitis, this ratio is characteristically less than one. Besides serum AST and ALT, other molecules can be studied to gain insight into liver disease. These include the enzyme alkaline phosphatase which is present in the liver, bone, and placenta. Elevations in serum alkaline phosphatase generally indicate obstruction of bile outflow from the liver, and concurrent elevation of alkaline phosphatase with elevation of liver enzymes suggests liver disease. Besides the aforementioned tests of general injury to hepatic cells, other laboratory tests can help gain insight into the functional capacity of the liver. Bilirubin is a degradation product of hemoglobin that is carried in red blood cells. Breakdown and excretion of serum bilirubin involves processing in the liver, where broken-down bilirubin is processed (conjugated) and ultimately excreted. Elevated levels of unconjugated bilirubin can suggest a deficiency of the liver to take up and conjugate bilirubin, and elevated levels of conjugated bilirubin suggest deficiencies in excretion (possibly arising from mechanical obstruction). Tests are also available to evaluate the synthetic capabilities of the liver. Albumin, a blood protein that is critical for binding molecules in the blood and maintaining its oncotic pressure, is synthesized in the liver. A decrease in serum concentration of albumin, although not entirely specific for liver disease, may be seen in chronic liver disease. Proteins involved with blood coagulation and hemostasis are processed in the liver, and tests such as the prothrombin time (PT)
1024 Liver Diseases (General) and the corresponding international normalized ratio (INR) may be elevated in liver disease. Aside from blood tests, evaluation of the liver also includes multiple imaging modalities that offer evaluation of the anatomy of the liver as well as the opportunity to possibly intervene when disease is present. Ultrasound of the liver is generally used to evaluate the biliary tree (predominant bile outflow tract of the liver) and evaluate for stones. Ultrasound can also detect large liver tumors and cysts. Advances in doppler ultrasonography can assess portal (liver-related) blood flow. Computerized tomography and magnetic resonance imaging are now used to evaluate the substance of the liver (parenchyma) to delineate intra-liver anatomy. Endoscopic retrograde cholangiopancreatography (ERCP) can be done by a gastroenterologist or hepatologist with advanced training—in this procedure an endoscope is advanced through the digestive system to ultimately visualize the biliary tree. If gallstones or other material is present causing liver outflow blockage, stone extraction or stenting can be done to relieve obstruction. Magnetic resonance cholangiopancreatography provides for visualization of the biliary tree; however, therapeutic intervention as with ERCP is not possible. Approach to Patient with Liver Diseases Approaching patients with liver disease often involves a combination of the aforementioned labs and imaging modalities. When these are completed, more specific serum laboratory tests may be pursued to establish a diagnosis; this is often combined with a liver biopsy in which a sample of liver tissue is obtained via a needle, and the obtained specimen is studied by a pathologist using microscopy. The term hepatitis is a nonspecific term and generally means inflammation of the liver; this can be secondary to viruses, autoimmune phenomenon, drugs, and a variety of other causes. Once diagnosis is established, therapy can be directed at the specific causative agents. Regardless of etiology, consistent and unaddressed insult to the liver can lead to a final pathway of permanent fibrosis and scarring, referred to as cirrhosis. The treatment of liver diseases in the 21st century centers on managing liver disease to prevent onset of cirrhosis and the attendant risk of hepatic failure. Once liver
A cluster of cancer cells with brown-staining cytoplasm is pictured within a portal tract of the liver
disease has progressed to the point of cirrhosis and hepatic failure, management is more focused on addressing the common comorbid conditions seen in patients with advanced liver disease including infection, edema, bleeding, and encephalopathy (altered mental status). Viral Hepatitis At the present time, there are currently five identifiable forms of viral hepatitis: A, B, C, D, and E. These viruses are considered hepatotropic, meaning that the liver is the primary site of infection where viral replication and cellular damage occur. Other viruses such as Epstein-Barr virus (EBV) and cytomegalovirus (CMV) can also affect the liver. As Dr. Kenneth Sherman explains, “All hepatitis viruses can cause acute infection, which is defined as the presence of clinical, biochemical, and serologic abnormalities for up to six months. Hepatitis A and E are cleared from the body within six months and do not cause persistent infection for a longer period. In contrast, hepatitis B, C, and D can lead to chronic infection, which is more likely to be associated with the development of cirrhosis. An increased risk of primary hepatocellular carcinoma occurs in patients who are chronically infected with hepatitis B, C, and D.” Management for the acute phase of viral hepatitis is
generally supportive with a focus on symptom-related management, serum profiles are drawn to try and identify a specific virus, and liver enzymes are followed over time. Treatment strategies exist and are consistently being refined to treat chronic infection with hepatitis B and C. Alcoholic Liver Disease The consumption of alcohol exerts a direct toxic effect on the liver. The spectrum of damage to the liver is highly variable and the amount of alcohol necessary to create permanent damage to the liver is also variable. In general, with consumption of alcohol there is mild elevation in serum aminotransferases and deposition of fat into the liver. This condition, known as “fatty liver,” can be seen in people with moderate alcohol consumption and is largely reversible with alcohol cessation. As Abittan explains, “Daily consumption of alcohol amounting to >45gm/day is associated with progressive liver injury.” With large episodes of alcoholic consumption, an acute hepatitis picture can develop. Treatment of alcoholic liver disease is centered on maintenance of absolute abstinence from alcohol. Nonalcoholic Fatty Liver Disease (NAFLD) Nonalcoholic fatty liver disease (NAFLD) is the most common liver disease in the United States. As Dr. Lisker-Melman describes, “The spectrum of histologic forms include hepatic steatosis (fat deposition), steatosis with nonspecific inflammation, and nonalcoholic steatohepatitis (NASH). NASH is characterized by steatosis, inflammation, necrosis, and fibrosis. Approximately 25 percent of patients with NASH progress to cirrhosis over a 10- to 15-year period.” At present, no established treatment is available for NAFLD. Metabolic Liver Disease A variety of genetic metabolic disorders can lead to liver disease. These include Wilson’s disease, hereditary hemochromatosis, and alpha 1-antitrypsin deficiency. Wilson’s disease is an inherited disorder in which there are abnormalities in the body’s processing of the compound copper; this disorder leads to abnormal copper deposition in the liver with resultant damage. Treatment for this disorder includes treatment with copper-chelating agents. Liver transplantation is curative in progressive disease. Hereditary
Liver Diseases (General)
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hemochromatosis is an inherited disorder in which there is abnormal absorption of iron in the intestine. There is excessive iron absorption and deposition into various organs including the liver. Therapy consists of phlebotomy (blood drawing) to deplete serum iron. Alpha 1-antitrypsin deficiency is a disorder in which a specific enzyme necessary in the lung and liver is not produced at an adequate level. Patients develop liver disease as well lung disease, generally early-onset emphysema. Autoimmune As Dr. Albert Czaja explains, “Autoimmune hepatitis is an unresolving inflammation of the liver of unknown cause that is characterized by hepatitis, autoantibodies, and hypergammaglobulinemia (an increase in immunoglobulins—protective molecules in blood serum). Autoimmune hepatitis mainly affects women and is generally diagnosed during the fourth decade.” Specific antibody tests exist to evaluate for autoimmune hepatitis. Treatment options for autoimmune hepatitis are being refined but generally involve the use of steroids to decrease inflammation. Variants of autoimmune hepatitis include primary biliary cirrhosis (PBC) and primary sclerosing cholangitis (PSC). Both of these disorders are associated with the occurrence of inflammatory bowel disease. Vascular Disease The liver constitutes 5 percent of body weight in adults and receives 20 percent of cardiac output via the hepatic artery and portal vein. Abnormalities in blood inflow or outflow can cause severe liver dysfunction acutely. Budd-Chiari syndrome results from obstruction of the venous outflow tract (the hepatic veins) from any etiology, including mechanical obstruction or thrombosis (blood clot). Most patients require decompression of the hepatic veins to preserve liver function. Other vascular-related insults to the liver include ischemic hepatitis or “shock liver” in which blood flow to the liver is compromised transiently with resultant dysfunction. In patients with congestive heart failure, inability of the heart to pump blood forward results in backup of blood flow on the venous return side and congestion of the liver with blood (congestive hepatopathy). In these instances treatment of the underlying vascular or cardiac disorder leads to a return of normal liver function.
1026 Liver Transplantation Disease Treatment The treatment of liver disease depends upon the specific cause of dysfunction. Treatment can range from supportive and symptomatic relief in the instance of an acute viral hepatitis to emergent surgery or liver transplantation in the event of an acute vascular event. In general, consistent liver injury, regardless of etiology leads to permanent damage and cirrhosis. With cirrhosis and decreased hepatic function come a variety of comorbid conditions that must be discussed when dealing with generally advanced liver disease. As aforementioned, the liver plays a critical role in detoxifying the blood, forming important blood proteins, and synthesizing clotting factors. When the liver fails secondary to progressive disease these protective functions are lost and the result is improper clearance of toxins, lack of important blood proteins, and the propensity for bleeding secondary to diminished clotting factors. Patients with advanced liver disease often have mental status changes (encephalopathy) secondary to their inability to clear blood toxins. Serum levels of toxins such as ammonia may be elevated in patients with hepatic encephalopathy; however, altered mental status is likely multifactorial and does not correlate well with serum levels of ammonia. The lack of important blood proteins such as albumin results in decreased oncotic pressure of the blood, and as a result, fluid that would normally remain in blood vessels transposes into soft tissues. The result is body-wide swelling (anasarca). Of particularly concern is swelling in the abdomen (ascities); fluid in abdomen is a nidus for infection. This infection is named spontaneous bacterial peritonitis and carries a high mortality in patients with liver disease. Treatment includes diuretics (promoters of urination) to manage swelling and prompt antibiotic therapy when infections develop. The issue of bleeding is twofold in patients with liver disease: (1) there is a decrease in clotting factors that predispose to bleeding and (2) cirrhosis creates portal hypertension and, as a result, there is backflow of blood into vessels that are generally not designed to handle that volume. These vessels are called varices and can rupture in the esophagus or stomach. Management of liver disease in general attempts to manage the dangerous complications of infection and bleeding.
SEE ALSO: Alcoholism; Cirrhosis; Encephalopathy; Hepa-
titis; Liver Cancer.
Bibliography. C. S. Abittan, “Alcoholic Liver Disease,”
Clinical Perspectives in Gastroenterology (v.2/1, 1999); A. J. Czaja, “Frequency and Nature of the Variant Syndromes of Autoimmune Liver Disease,” Hepatology (v.28, 1998); M. Lisker-Melman, “Liver Diseases,” Washington Manual of Medical Therapeutics, 31st ed. (Lippincott, Williams, and Wilkins, 2004). Anil Seetharam, M.D. Washington University in St. Louis
Liver Transplantation Liver transplantation is a surgical procedure whereby a whole liver is removed from a cadaveric donor and implanted into a recipient in an effort to restore normal hepatic function. Used as a primary treatment for end-stage liver disease (ESLD) resulting from cirrhosis, autoimmune liver pathologies, some liver cancers, and hepatitis, the first cadaveric liver transplantation was performed in Pittsburgh, Pennsylvania, in 1967. Since the advent of the procedure, the demand for donor livers has grown. Experts have begun meeting this challenge in several ways. In the 1980s, fueled by the need to transplant pediatric donors with smaller livers, surgeons began transplanting reduced-size allografts for younger patients. This advance led to split-liver transplantation whereby one cadaveric donor liver is separated for implantation into two recipients. Although each section is smaller than a whole organ, the inherent ability of the liver to regenerate in response to injury or volume loss facilitates procedures of this nature. The surgical skills and knowledge gained from the aforementioned interventions later enabled surgeons to begin performing partial liver transplants from living donors. While these and other advances help ameliorate the disparity between supply and demand, persisting shortages still mandate the prudent allocation of available livers. In 2002, the United Network for Organ Sharing (UNOS) began using the model for endstage liver disease (MELD) to evaluate potential liver
Locus
recipients based on medical urgency. This new method of organ allocation bases recipient selection on parameters tied to patient mortality instead of absolute waiting time. In addition to patient evaluation by the UNOS MELD score, patients are also evaluated for potential contraindications to transplantation such as limited cardiovascular/respiratory function, advanced malignancy, or active infection such as HIV. Once a liver recipient has been identified, procurement is completed via one of several surgical methods depending on the type of donation and the specific donor’s anatomy. All cadaveric liver procurements involve a long midline incision necessary to expose both the thoracic and abdominal cavities and rule out malignant pathologies. The majority of hepatic surgical dissection is then performed before or after a systemic flush of the donor’s blood with cold preservation solution. To ensure the organ is perfused with preservation solution, the main blood vessels to and from the liver are the last to be transected. In contrast, living donor transplantation involves a less invasive donor incision which exposes only enough of the liver as is necessary for procurement. Additionally, extra care must be taken to ensure that dissection of the donated portion of the liver does not interfere with the normal perfusion and function of the remaining part. Since the inception of liver transplantation, advancements in organ preservation, better immunosuppressant therapies, and effective management of complications have led to a five-year allograft survival rate of 71 percent and a patient survival rate of 80 percent in the United States. Complications include infection, acute or chronic rejection, vascular occlusion, and renal dysfunction secondary to liver transplantation. In a study of 181 liver transplants performed between 1998 and 2000, researchers found one-week acute renal dysfunction rates of approximately 39 percent and chronic renal dysfunction was discovered in about 6 percent of patients during longterm follow-up. Renal dysfunction may indicate a necessary change in immunosuppressant therapy to include less nephrotoxic therapeutics. Of increasing interest is the longterm incidence of malignancy related to solid organ transplantation. Studies agree that the development of malignancy is multifactorial and related to the type
1027
of transplant, the preexistence of any diseased states, the serological status of the recipient, and immunosuppressant use. Vigilant identification of long-term liver transplantation risks aids in treatment and reduces transplant-related morbidity and mortality. SEE ALSO: Allograft; Immunosupression; Organ Donation;
Organ Transplantation; United Network for Organ Sharing (UNOS). Bibliography. K. A. Brown, “Liver Transplantation,” Cur-
rent Opinion in Gastroenterology (v.21, 2005); J. D. Crossin, D. Muradali, and S. R. Wilson, “US of Liver Transplants: Normal and Abnormal,” RadioGraphics (v.23, 2003); M. I. Prince and M. Hudson, “Liver Transplantation for Chronic Liver Disease: Advantages and Controversies in an Era of Organ Shortages,” Postgraduate Medical Journal (v.78, 2002); A. Said and M. R. Lucey, “Liver Transplantation: An Update,” Current Opinion in Gastroenterology (v.22, 2006); D. S. Seaman, “Adult Living Donor Liver Transplantation,” Journal of Clinical Gastroenterology (v.33/2, 2001); K. Washington, “Update on Post-Liver Transplantation Infections, Malignancies, and Surgical Complications,” Advances in Anatomic Pathology (v.12, 2005). Jason Palmatier Independent Scholar
Locus In genetics, a locus is the position of a gene on a chromosome. Genes are located on chromosomes in a linear fashion, and each gene, or one of its alleles, have precise locations or loci on chromosomes. The exact chromosomal address of a gene may look something like “1p34.2”, where “1” designates the chromosome number, “p” designates the long arm or the short arm, and “34.2” is the exact location of the gene on that chromosomal arm. These numerical positions can be seen using a microscopically viewable ideogram of chromosomes that have been stained using one of several staining techniques like Giemsa Banding (G banding). By G-Banding chromosomes in metaphase, individual areas of chromosome absorb chemicals differently, giving chromosomes their banded appearance; then numbers and letters are used to pinpoint
1028 Longitudinal Study exact locations of genes. If a higher-resolution banding is used, sub-bands and sub-sub-bands become visible. Sometimes, groups of genes occupy larger areas on chromosomes, and their location may be given as “11q14-q21” which is the OCA1 gene. This means that the genes extend from band q14 to band q21. The distance between two loci is a very important parameter in clinical genetics. It gives us critical information on linkage between two or more genes, where linkage is the probability for neighboring alleles on a common chromosome to be transmitted together, as an intact unit, through meiosis. Linkage is the only method that allows us to create gene maps and trace disease genes along family generations. The distance between loci is the only predictor of genetic linkage. Genetic distance is measured in units called centiMorgans (cM), which is defined as the genetic length over which, on average, one observes recombination 1 percent of the time. To measure distance between two loci, we need to know two variables: the recombination fraction between the two loci, and whether this recombination fraction deviates from 0.5. From these two variables, we can compute the lod score (Z) for “logarithmic of the odds.” Positive values of Z (odds>1) suggest the loci are linked, and negative values (odds<1) suggest loci are unlinked. Genes located on a chromosome are not necessarily linked. These are called syntenic loci regardless of how far apart they are from each other, or how close together they lie on the chromosome. If two syntenic loci are so far apart that there is going to be at least one crossover between them with every meiosis, recombinant and nonrecombinant genotypes will occur in the offspring in equal proportions and the two loci will appear to be unlinked just as if the loci were on separate chromosomes. Locus heterogeneity is a situation in which identical clinical symptoms are caused by abnormalities at two or more genetic loci. If locus heterogeneity is unrecognized, it can confound genetic linkage analysis and give the false impression that a marker is unlinked to a disease locus when in fact it may be linked, but only in a subgroup of all families analyzed. SEE ALSO: Chromosome, Cytogenetics, Genetic Disor-
ders, Genetic Testing/Counseling, Genetics.
Bibliography. Susan Elrod, Schaum’s Outline of Genet-
ics, 4th ed. (McGraw-Hill, 2001); Robert L. Nussbaum,
Roderick R. McInnes, Huntington F. Willard, Genetics in Medicine, 6th ed. (Thompson & Thompson, 2001). Rahul Gladwin, M.D. University of Health Sciences-Antigua
Longitudinal Study A longitudinal study involves the repeated collection of data over time. When the data are collected over time from the same cases, this can also be described as a panel study. Longitudinal studies can also be retrospective if they involve the tracing of archived records over time (e.g., medical records for a group of patients). In contrast, a cross-sectional study involves the collection of data at only one point in time. Longitudinal designs offer unique advantages; by being able to track changes to cases over time, researchers can develop a more nuanced view of dynamic effects and can begin to develop more powerful tests of causality. Longitudinal designs can also incorporate other methodological dimensions, such as a hierarchical (or multilevel) structure. This enables the differentiation of effects of compositional factors (i.e., characteristics of cases or individuals) and contextual factors (i.e., characteristics of groups or areas) over time. For example, the British Household Panel Survey has collected data on a representative sample of the United Kingdom since 1991. The study’s sample consists of more than 5,000 households, and includes over 10,000 individual interviews per year. The same individuals are interviewed year after year, and if a member of a household forms a new household, the new household is incorporated into the survey as well. It includes measures of physical and psychological well-being, as well as measurements of income, employment status, individual demographics, and household composition. The Longitudinal Survey of Immigrants to Canada offers an example of a longitudinal study of shorter duration. It consists of a sample of 20,000; participants are interviewed at three different times: at six months (wave 1), two years (wave 2), and four years after landing in Canada (wave 3). Data from this survey can be used to examine how new immigrants adjust to life in Canada over time; more specifically, this survey offers data on how the health of new immigrants changes
Lou Gehrig’s Disease
after arriving in Canada, enabling analysis of underlying social mechanisms affecting changes in health. Other examples of longitudinal studies include the U.S. Panel Study of Income Dynamics and the Canadian Longitudinal Study on Aging. However, while offering researchers powerful advantages (such as the ability to examine dynamic effects), longitudinal designs also have inherent limitations. These include the problems of mobility, population change, and repeated interviewing effects. The notion of mobility is problematic if respondents move during the life of the study; it can be very expensive to track mobile respondents, and unless care is taken to track and document such moves, the results of the panel may be biased. Population change is problematic if it results in the panel sample itself losing its representativeness as time goes on; this may be a considerable problem over lengthy follow-up periods. Repeated interviewing effects, or panel conditioning effects, suggest that respondents may be influenced by their participation in the survey and, over time, begin to give biased responses. Longitudinal studies are administratively complex, costly to implement, and require a degree of institutional stability if the study is to collect data for an extended period of time. However, these disadvantages are offset by the unique perspective that longitudinal studies offer on dynamic effects. As such, longitudinal studies have been particularly important in the study of the health effects of poverty and unemployment, wherein the length of time respondents live in poverty or are unemployed may be a critical factor in influencing their health. SEE ALSO: Cross-Sectional Study; Retrospective Study. Bibliography. Kenneth Rothman and Sander Green-
land, eds., Modern Epidemiology (Lippincott Williams & Wilkins, 1998); David De Vaus, Surveys in Social Research (Routledge, 2005). Fernando De Maio, Ph.D. Simon Fraser University
Lou Gehrig’s Disease Lou Gehrig’s disease (LGD) also known as amyotrophic lateral sclerosis is a chronic disease of the
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nerve cells in the brain and spinal cord that are responsible for voluntary muscle movement. It is the most frequent adult-onset motor neuron disease. The worldwide prevalence for the disease is four to six per 100,000; the worldwide annual incidence rate is 0.4 and 1.8 per 100,000 population. It affects more males than females. Mean age of onset for the disease is 56 years although for familial disease, it is 46 years. LGD is a late-onset disease similar to Alzheimer’s and Parkinson’s disease characterized by protein aggregates and neuronal loss. The patient suffers from progressive degeneration of upper motor neurons (UMNs) and lower motor neurons (LMNs) of the spinal cord. UMN degeneration is associated with degeneration of the lateral corticospinal tracts in the spinal cord leading to signs of hyperreflexia (exaggerated reflexes including an overactive gag reflex) and spastic weakness of limbs (primary lateral sclerosis), stiffness, slowness, clumsiness of movement, limb spasticity (a specific type of stiffness), abnormally brisk jaw jerk, Babinski’s sign (the large toe extends upward as the sole of the foot is stimulated) and diminished fine motor coordination. LMN degeneration is associated with muscle denervation which leads to spinal muscular atrophy (limb weakness) and fasciculations (involuntary muscle contraction), slurred speech (dysarthria), difficulties in swallowing (dysphagia), and difficulties in mastication. During diagnosis, most patients present with a mixture of UMN and LMN symptoms. Patients may have bulbar symptoms of choking during a meal and also have respiratory weakness and a small number of patients may present with dementia and Parkinsonism. Patients may also have cognitive impairment such as apathy and behavior abnormalities. Patients may have cardiac arrhythmias and hypoxia, which can lead to death. Around 15 to 45 percent of patients experience pseudobulbar effect, which consists of uncontrollable laughter or crying. The etiology of the LGD is complex. It is multifactorial involving both genetic and environmental factors, but for the vast majority of patients with ALS, the etiology of the disorder is unknown. Most cases of LGD appear sporadically; in approximately 10 percent of cases, LGD is transmitted in an autosomaldominant manner (familial LGD). The most commonly mutated gene encodes superoxide dismutase type 1 (SOD1); this functions as an antioxidant and is
1030 Low Blood Pressure responsible for 20 percent of familial cases. The protein encoded by this gene binds copper and zinc ions and is one of two isozymes responsible for destroying free superoxide radicals in the body. The encoded isozyme converts naturally occurring but harmful superoxide radicals to molecular oxygen and hydrogen peroxide. The other isozyme is a mitochondrial protein. More than 100 SOD1 mutations that cause LDG have been identified; most of these mutations are dominant mutations and replaces the amino acid arginine with the amino acid valine at position 4 in the enzyme (Arg4Val). One mutation that may be dominant or recessive is the substitution of alanine for aspartate at position 90 (D90A). The remaining 80 percent of familial cases are caused by mutations in other genes, such as one that encodes the regulator of axonal retrograde transport protein dynactin and mutations in the ALS2 (amyotrophic lateral sclerosis 2 [juvenile]) gene that provides instructions for making a protein called alsin produced in a wide range of tissues, with highest amounts in the brain. The SETX (senataxin) gene, which provides information for making the protein senataxin present in the central nervous system, and VAPB (vesicle-associated membrane protein) genes found throughout the body are also thought to cause LGD. Another possible cause of LGD is glutamate toxicity; LGD patients have higher levels of this neurotransmitter in their serum and spinal fluid; prolonged exposure to high levels of glutamate causes degeneration of neurons. One cause of excess glutamate could be due to the failure of astrocyte (glial cell in the brain) to sequester glutamate from the extracellular fluid surrounding the neurones. Other factors such as mitochondrial dysfunction, autoimmunity, viral infection, Prion disease, and exposure to heavy metals may be involved in pathogenesis of the disease. The diagnosis for the disease is based on physical examination, electrophysiology, and excluding other confounding conditions. Magnetic resonance imaging of the brain and spinal cord is performed to exclude conditions that might stimulate this condition such as multiple sclerosis, cervical spondylosis, syringomyelia, brainstem strokes, and tumors. Electromyography (special recording technique that detects electrical activity in muscles) may be employed which may
show fibrillation and fasciculations. Another common test measures nerve conduction velocity (NCV); abnormalities in NCV may suggest a diagnosis of, for exampl, peripheral neuropathy rather than LGD. LGD is not a curable disorder; however, certain treatments can improve survival and quality of life. Medical treatments for the disease include the drug riluzole, which may reduce damage to motor neurons by decreasing the release of glutamate; it is thought to prolong survival in patients by about two months. As free radical accumulation and oxidative stress contributes to the disease, a range of antioxidant medications such as vitamins C and E, selegiline, selenium, methionine, and acetylcysteine were thought to be useful for LGD; however, efficacy of antioxidants is poor. There are also drugs to help individuals with problems such as pain and sleep disturbances; the latter may also be relieved with the use of nocturnal ventilatory assistance if the patient also has breathing problems. Prognosis of LGD is very poor. It progresses very rapidly, and most patients die within five years of diagnosis, often from asphyxia. However, 30 percent of patients with LGD live five years after diagnosis. Long-term survival is associated with a younger age at onset and being male. SEE ALSO: Brain Diseases; Neurologic Diseases (General). Bibliography. E. Talbot et al., eds., Amyotrophic Lateral
Sclerosis, 2nd ed. (Informa Healthcare, 2006); Mary Dodson Wade, ALS: Lou Gehrig’s Disease (Enslow Publishers, 2001). Farhana Akter King’s College, London
Low Blood Pressure Low blood pressure, generally referred to by medical professionals as hypotension when it is abnormally low, is a physiologic state of ill-health rather than a disease. In fact, the occurrence of low blood pressure is often an indication of another disease. For instance, low blood pressure is a factor that can occur after poisoning with a depressive drug, such as
a barbiturate, and can occur with shock or the onset of poliomyelitis. The low blood pressure can happen either because of a reduction in blood volume or an increase in blood vessel capacity. The opposite is hypertension, high blood pressure. The blood pressure of all humans is regulated by the automatic nervous system, which utilizes a large network of nerves, receptors, and hormones to balance the effects of the sympathetic nervous system, which is often involved in the raising of blood pressure, and the parasympathetic nervous system, which lowers it. These two counteracting forces allow individuals to maintain an acceptable blood pressure over a wide range of physical and mental activities, and even when they have contracted diseases or are suffering from particular disorders. Low blood pressure is often accompanied by other medical problems that are usually the way in which people discover their low blood pressure. It may involve an irregular heartbeat, some chest pain, a headache, some shortness of breath, or a fever higher than 101 degrees Fahrenheit (38.3 degrees Celsius). Other problems may involve a severe upper back pain, a stiff neck, dizziness or light-headedness, profound fatigue, or even a loss of consciousness. Obvious signs may involve a burning sensation when urinating, foul-smelling urine, prolonged diarrhea or vomiting, coughing with phlegm, or even a loss of appetite and an inability to eat or drink. It may lead to allergic reactions and have an adverse effect on the taking of medications. Indeed, some food and medication that have been found to cause low blood pressure have been taken by athletes to help them in particular sports. As a result, many of these medications are now banned in world competitions. One of the main reasons for people suffering from low blood pressure is hypovolemia, or having a reduced blood volume. This can occur when there is a decreased sympathetic nervous system output, or increased parasympathetic activity. It often occurs as a result of serious injury where a person loses much blood, or from an injury to the brain or spinal cord, or can come from an intrinsic abnormality in the automatic system functioning. There can also be other factors in vasodilation, which can come from inappropriate medication, or people undergoing various anesthetic procedures especially spinal anesthesia.
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The occurrence of low blood pressure is often an indication of another disease.
There are three main syndromes connected with low blood pressure: orthostatic hypotension, neurocardiogenic syncope, and postprandial hypotension. Orthostatic hypotension comes from low blood pressure when someone stands up, especially standing up quickly. It seems to come from a failure in the automatic nervous system to cope with this change, and often, at its mildest, results in dizziness until the automatic nervous system alters itself to deal with the new situation. The low blood pressure occurs because when a person stands up, there is a reflex constriction in the small veins and arteries to offset the gravitational effects. Although dizziness is common, it may also lead to fainting. Neurocardiogenic syncope is a form of dysautonomia that is characterized by a quick and inappropriate fall in blood pressure while a person remains in the upright position. It is related to vasovagal syncope as both can occur when there is increased activity in the vagus nerve, which is the main part of the parasympathetic nervous system. Postprandial hypotension is rare and occurs from 30 to 75 minutes after a meal. It comes from the fact that digestion results in much blood going to the intestines, and the heart rate increases to allow for this. Vasoconstriction should then occur to compensate for the lower volumes of blood. However, when vasoconstriction does not happen, there can be a sudden loss in blood pressure. SEE ALSO: High Blood Pressure; Neurology.
1032 Low Vision Bibliography. W. R. MacRae and J. A. W. Wildsmith, In-
duced Hypotension (Elsevier Science, 1991); Moyses Szklo and F. Favier Nieto, Epidemiology: Beyond the Basics (Jones and Bartlett, 2004).
Justin Corfield Geelong Grammar School, Australia
Low Vision Low vision is a form of visual impairment that restricts daily activities and is not correctable with eye glasses, contact lenses, medicine, or surgery. There are approximately 161 million people with visual impairment in the world; it is believed that 124 million of these people have low vision. While low vision affects communities worldwide, the majority of those with untreated vision impairment live in developing countries. It is estimated that at least half of those with low vision could be assisted with devices such as magnifiers and telescopes, and specialized services such as mobility training. Unfortunately, low vision is not well understood as a public health concept, and as a result, has not been successfully integrated into many healthcare systems. Without access to low-vision devices and services, individuals suffer from social exclusion and reduced quality of life. Families, communities, and society as a whole are deprived of the economic and humanitarian contributions of these individuals. The personal, social, and economic losses caused by low vision are unnecessary and preventable. The International Statistical Classification of Diseases, Injuries, and Causes of Death describes visual impairment as an umbrella term encompassing blindness and low vision. The current medical definition of low vision is visual acuity of less than 6/18, but equal to or better than 3/60, or a corresponding visual field loss to less than 20 degrees in the better eye using best possible correction. In comparison, normal vision is defined as 20/20; blindness is defined as less than 3/60. Visual acuity is expressed as a fraction; the numerator is the number of feet between a person and a vision screening chart; the denominator is the distance at which a person with normal eyesight could clearly see the smallest characters on the chart. For example,
a person with low vision has visual acuity of less than 6/18; they clearly see at six feet away what a person with normal vision is able to see at 18 feet away. Low vision can be caused by macular degeneration, cataracts, corneal scarring, glaucoma, diabetic retinopathy, stroke, eye injury, or genetic conditions like albinism. There are three different types of low vision: loss of peripheral or side vision commonly caused by stroke or glaucoma, loss of central vision commonly caused by macular degeneration or macular/foveal hypoplasia in albinism, and general blurred vision commonly caused by cataracts, corneal scarring, or diabetic retinopathy. The National Eye Institute has identified some warning signs of low vision that may help people seek early treatment and diagnosis. With regular prescription eyeglasses, individuals with low vision may have difficulty recognizing familiar faces, doing things that require seeing clearly up close, such as reading, cooking, sewing, fixing things around the house, picking out colors, doing things at work or home because lights seem dimmer than they used to, or reading street and bus signs or the names of stores. Normal vision changes are natural; however, low vision is not a natural part of the aging process. It is recommended that adults have dilated eye exams at least every four years in their 20s, at least every four years in their 30s, every two years in their 40s, and annually starting at age 60. People with a family history of glaucoma, or those diagnosed with diabetes or HIV/AIDS should have dilated eye exams at least once a year. Low vision can affect people of all ages and backgrounds. The earlier it is recognized, the more likely specialists will be able to work with individuals to preserve the vision they have. Magnifiers, high-intensity lamps, pocket-sized telescopes, closed-circuit televisions that magnify and project material up to 60 times, talking alarm clocks, and large-print publications are some of the innovations that allow people to continue living independently. Low vision rehabilitation services teach effective methods to carry out daily tasks, and provide training in the use of low vision aids. Preserving vision through technology and rehabilitation allows people to live full lives despite having low vision. Approximately 124 million people have low vision. The majority of these people live in developing countries where access to eye care professionals, technological devices, and rehabilitative services is limited. Low vision is not well understood as a public health concept
Lung Cancer
distinct from blindness, and as a result, has not been successfully integrated into many healthcare systems. Without access to regular eye care, low-vision devices, and services, individuals suffer from social exclusion and reduced quality of life. Families, communities, and society as a whole are deprived of the economic and humanitarian contributions of these individuals. The personal, social, and economic losses caused by low vision are unnecessary and preventable. SEE ALSO: Blindness; Eye Care; Eye Disease (General); Na-
tional Eye Institute (NEI); Ophthalmology.
Bibliography. The International Society for Low-Vision
Research and Rehabilitation, Toward a Reduction of the Global Impact of Low Vision: The Oslo Workshop Report http://www.islrr.org/Oslo%20Workshop%20Report.pdf (cited July 2007); Serge Resnikoff, et al., “Global Data on Visual Impairment in the Year 2002,” Bulletin of the World Health Organization (v.82/11, 2004). Jennifer Hissett University of Colorado at Denver and Health Sciences Center
Lung Cancer Lung cancer is the uncontrolled growth of abnormal cells in one or both lungs. The abnormal cells reproduce rapidly and form lumps of cancer cells (tumors) that disrupt the lung, making it difficult to function properly. The results of different studies indicate that 85 to 95 percent of lung cancers are smoking related, including second hand smoking-related causes. Environmental factors also play a significant role in causing lung cancer. The most effective prevention of lung cancer is to quit smoking, although this habit is extremely hard to quit for heavy smokers or people who started to smoke at an early age. Furthermore, the risk for smokers remain elevated for several years after quitting, therefore life long abstinence from smoking is considered the best way of preventing lung cancers. The signs and symptoms of lung cancer, such as persistent cough and chest pain, may take several years to appear, and they are often confused with the symptoms of less serious conditions. Therefore, they may
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not be detected correctly until the disease reaches an advanced stage. The treatment consists of surgical removal of the tumor and surrounding tissue, chemotherapy, radiation therapy, or some combination of these methods. There are also new types of therapies that are still being investigated, such as monoclonal antibodies (engineered antibodies that target specific protein cells) and photodynamic therapy (combination treatment with chemicals and light). Despite the scientific developments in its diagnosis and treatment, lung cancer is the leading cause of cancer deaths worldwide. It is the most common cancer in men and fifth most frequent cancer in women. However, lung cancer has become more prevalent among women worldwide since the 1970s because more women have started smoking and work in environmentally hazardous conditions. Lung cancer is more common in the developed countries, such as the United States and Western European countries; however, the percentage of five-year survival rate is also significantly higher in those countries than the developing countries, such as India and China due to the better medical services available in those countries. Lung cancer is commonly defined as the uncontrolled growth of abnormal cells in one or both lungs. The lung cancer cells grow in an uncontrollable and unlimited way, and they “invade” the nearby normal tissue and destroy the organ structure. The abnormal cells reproduce rapidly in this process and form lumps of cancer cells (tumors) that disrupt the lung, making it difficult to function properly. These cells can also break down lung tissue structure and enter the bloodstream or lymphatic system, thus spread to distant organs in other parts of the body, a process that is called metastasis. Clinically, there are two types of lung cancer, which are differentiated according to their cell types under microscopy: non-small cell lung cancer and small cell lung cancer, which is also called oat cell cancer. Non-small cell lung cancer is the most common type of lung cancer in the world, and has three major categories: Adenocarcinoma, which is the most common type of lung cancer among women and people who have never smoked, squamous cell cancer, which is most common type of cancer among men, and large cell carcinoma. Small cell lung cancer develops in the central areas of the lung and it is the most aggressive type of lung cancer. It is found almost exclusively among smokers and it is
1034 Lung Cancer
Different studies have shown that 85 to 95 percent of lung cancers are smoking related, including those caused by second-hand smoke.
more likely to spread to other parts of the body than non-small cell lung cancer. Different studies have shown that 85 to 95 percent of lung cancers are smoking-related, including those caused by second-hand smoke. The tar in cigarette smoke contains numerous substances that cause cancer (carcinogens), as well as substances that accelerate the production of cancer cells (cocarcinogens). The risk is associated with the frequency and years of smoking. People who smoke more than one pack of cigarettes have a 20 times greater risk of developing lung cancer compared with those who have never smoked. Because some cigar and pipe smokers do not inhale smoke directly, they have a slightly lower risk of developing lung cancer than the cigarette smokers, but other smoking-related disease are common among them. They are also more likely to have lung cancer compared to the non-smokers. The association between smoking and lung cancer works differently in men and women: Men who smoke increase
their risk of death from lung cancer by more than 22 times, and women increase their risk of death from lung cancer by more than 12 times when compared with non-smokers. The non-smokers diagnosed with lung cancer are more likely to be women than men, which made the scientists explain that difference with second-hand smoking and women’s genetic susceptibility to environmental pollution. Since not all smokers develop lung cancer and not all patients diagnosed with lung cancer smoked, additional research focus on other risk factors such as the genetic and environmental ones. Accordingly, other risk factors for developing lung cancer include, occupational exposures to arsenic, asbestos, chromium and mustard gas; residential radon exposure, radiational exposures from medical sources and environment, and air pollution. Genetic susceptibility to the disease, nutritional factors and a history of tuberculosis, which weakens the lungs considerably are also thought to be possible risk factors in combination with smoking and environmental factors. Smoking cessation or lifelong abstinence from smoking are the primary ways to prevent lung cancer and deaths due to this disease. All over the world, health institutions launch massive campaigns in order to raise public awareness on the health risks of smoking. They use media, especially T.V., newspapers and movies, extensively in order to reach people from different demographic groups and socio-economic background. The campaigns often address children and adolescents in order for those people learn about the dangers of smoking for their health at an earlier age and have a life-long abstinence. However, despite those campaigns and increased social and institutional assistance for the people who want to quit smoking permanently, this habit is proven to be extremely hard to quit, especially for heavy smokers or people who started to smoke at an earlier age. Many people quit smoking when they must do so for medical reasons, as a part of their lung cancer or tuberculosis treatment. Moreover, the risk for former smokers to develop lung cancer remains elevated, compared to a non-smoker, but it continuously falls with the number of years of smoking cessation. After 10 years of abstinence, a person who has quit smoking reduces her risk to 30-50 percent. In order to reduce the environmental risk factors for lung cancer, countries should balance their economic and industrial development with en-
vironmental concerns and measurements for the occupational safety. For instance, as a result of rapid and unregulated urbanization and industrialization processes in developing countries and in the poorer parts of the developed countries, the people in those places are more likely to be exposed to such chemicals. The lung cancer’s signs and symptoms may take years to appear, and they are often confused with the symptoms of less serious conditions. The signs and symptoms of lung cancer often appear when the disease has already reached an advanced stage. The typical symptoms of lung cancer are persistent cough (coughing more than two weeks), persistent chest, shoulder or back pain unrelated to pain from coughing, change in color or increase in volume in sputum (the liquid coughed up from the throat or lungs), blood in sputum, wheezing and shortness of breath. There are also other common symptoms that may not be respiratory in nature, such as chronic fatigue, loss of appetite, headache, bone pain, aching joints, neck and facial swelling, and unexplained weight loss. Some lung cancers are detected through a routine chest X-ray or one taken for other disorders. However, chest X-rays are not recommended as screening tools for lung cancer, even for high-risk individuals, since they may not be accurate enough. A computerized tomography (CT) scan is recommended, since it may reveal even very small lesions and metastasis. For detecting lung cancer and its spread, magnetic resonance imaging (MRI), positron emission topography (PET) are also effective. In order to determine if cancer is present, and if so, what type of it is, the doctors obtain a specimen of tissue for microscopic examination (biopsy). For the individuals who demonstrate the greatest risk for lung cancer, such as heavy smokers and or people who were regularly exposed to lung cancer-inducing chemicals, a recent method of “chemoprevention” is also used. This method aims at reducing the risk of cancer and its recurrence, and it is a combination of chemotherapy, vitamins, diet, and hormone therapy. Other than this treatment, the standard treatment methods for different types of cancer are also valid for the lung cancer treatment. These methods are surgical removal of the tumor and surrounding tissue, chemotherapy, radiation therapy or some combination of these treatments. Laser surgery may be also used in order to improve breathing when tumors
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obstruct central air passageways or removal of tumor is not possible. Since surgery often involves the removal of an entire portion or lobe of the lung in which the cancer is located, the doctors have to consider the condition of the patients’ other lung before the operation, especially in the case of heavy smokers. In order to determine the function of the non-cancerous lung, they doctors often apply breathing tests to the patients before the operation. In chemotherapy, the patients take anticancer drugs either by mouth or intravenously. The drugs are designed to reach tissues throughout the entire body in order to destroy any cancer that may have spread beyond the lung. It is usually the preferred treatment for the people with small cell lung cancer. On the other hand, surgery is not applied in small cell lung cancers, since the chance of removing all of the cancer surgically is small. In the radiation therapy, a beam of high-energy radiation is aimed at the tumor to destroy the cancer cells. This method can also be used to relieve lung cancer signs and symptoms, such as pain, bleeding and difficulty in swallowing. Both chemotherapy and radiation therapy have several common side effects, such as nausea, loss of appetite and fatigue in chemotherapy; and inflammation of the lungs and decreased lung functions in radiation therapy. The success of these therapies depends on the person’s general health condition and how early the lung cancer is detected. There are also new types of therapies, which are still investigated, such as monoclonal antibodies (engineered antibodies that target specific protein cells) and photodynamic therapy (combination treatment with chemicals and light). There are also targeted therapies, which are the treatments designed to block or inhibit cellular function in lung cancer cells. These therapies are still under clinical investigations and they are rarely used for the lung cancer patients, except for experimental reasons. Medical researchers also work on the production of lung cancer vaccines in order to stimulate effective immune response against the disease. Despite the scientific developments in its diagnosis and treatment, lung cancer is the leading cause of cancer deaths worldwide. It is the most common cancer in men and fifth most frequent cancer in women. Lung cancer has become more prevalent among women worldwide since the 1970s, because more women start smoking and work in environmentally hazardous conditions. According to Parkin et al, the incidence of lung
1036 Lung Transplantation cancer is slowly declining since the late 1980s (2.6 percent decline between 1990–1996), as well as the death rate from lung cancer, among men in North America, as a result of the alterations of prevalence in smoking in the population. On the contrary, death rate from lung cancer among North American women increased and it even began to exceed the breast cancer death rates in certain years since the 1990s. As a result of Sir Richard Doll’ study, which showed that smoking is the cause of the most lung cancer in Britain in 1950, and the widespread smoking cessation after that study, Britain had the largest decrease in the world in premature deaths from lung cancer. Professor Doll’s new study showed that, although the UK had the worst lung cancer death rates in the world in 1950, the lung cancer deaths halved by smoking cessation between 1950-2000 in England. Nation-wide campaigns against smoking and its harmful effects also became influential in England and played a considerable role in the decrease of death rates from lung cancer. Other important reasons for the fall in mortality rates in England are the earlier diagnosis and better treatment. However, the other countries, especially the developing ones, are unlikely to experience such decline in the near future, because of the increase in the smoking habit. Cancer Research UK, a team of cancer researchers in England, have analyzed the global cancer information and indicated that the developing countries will have to cope with soaring rates of lung cancer, which is already most commonly diagnosed cancer in the world. Especially in the regions of eastern Africa, central America and Southeast Asia, where the prevalence of smoking has increased considerably, there will be big increases in the numbers of people diagnosed with lung cancer over the next twenty years. Professor John Toy, the medical director of Cancer Research UK, argues that the developing countries can learn from the past mistakes of the developed countries on lung cancer and tackle the smoking habit in order to minimize future lung cancer cases, which would also reduce the future cancer burden in those countries. The lack of adequate medical services for the diagnosis and treatment of lung cancer is also an important problem for many developing countries, and those problems are reflected in the five-year survival rates after the lung cancer treatment. Although lung cancer is more common in the developed countries, such as the United States and
countries in Western Europe, the percentage of fiveyear survival rate is also significantly higher in those countries than the developing countries, such as India and China. In order to decrease the rates of lung cancer and death rates from this disease, the developed countries should collaborate with the developing ones, in order to raise a global awareness on lung cancer and how to prevent it, especially in the issues of smoking cessation and life-long abstinence. The importance of early diagnosis in cancer, particularly in the case of lung cancer, should be also emphasized in the developing, as well as the developed, countries, especially in the ones where smoking habit has become more common. Finally, the developed countries should cooperate with the developing ones, in order to improve those countries’ medical services and technology with respect to the latest medical developments, so that those countries can have a more effective lung cancer treatment. SEE ALSO: Cancer (General); Cancer Chemotherapy; Can-
cer Radiation Therapy; Smoking; Smoking Cessation.
Bibliography. CancerCare, Lung Cancer 101:About
Lung Cancer, www.lungcancer.org (cited July 2007); Mayo Foundation for Medical Education and Research, “Lung Cancer,” Mayo Clinic Family Health Book, 3rd ed. (Collins, 2003). Aysecan Terzioglu Ph.D. City University of New York
Lung Transplantation Lung transplantation involves a major operative procedure and is considered treatment for end-stage lung diseases unresponsive to other therapies. Because of advancements in surgical technology and control of rejection, the one-year survival rate following lung transplantation is 82 percent and the three-year survival rate has increased from 55.7 percent (1988–1994) to 63.3 percent (2000–2003). The primary diseases for which lung transplantation is considered include chronic obstructive pulmonary disease (COPD), a term referring to both emphysema (including those cases due to inherited deficiency
Lupus
of alpha-1 antitrypsin) and chronic bronchitis; idiopathic pulmonary fibrosis; cystic fibrosis, an inherited disease typically manifesting itself in childhood which involves primarily the lung and gastrointestinal tract; end-stage sarcoidosis. Because of a shortage of donor organs, the total number of patients who underwent lung transplantation in 2003 numbered less than 1,800 and it has been estimated that upward of 20 percent of transplantation candidates die while waiting for donor lung(s). Prior to being placed on a transplantation list, patients are referred to a transplant center for evaluation. In addition to physiologic testing, extensive psychosocial evaluation and counseling is performed. Pre- and posttransplant psychological functioning has been found to be an important predictor of quality of life and adherence to life-sustaining medical treatment following transplantation. Contraindications to lung transplantation vary among centers but may include age over 65 years, current tobacco smoking, current alcohol or substance abuse, human immunodeficiency virus (HIV) infection, intractable infections, unstable mental illness, and generalized debility. Once placed on a lung transplantation list, patients undergo extensive tissue typing (done so that compatible organs can be sought) and categorized as to the urgency of their need for transplantation. Patients are thereafter “on call” for transplantation and must guarantee their ability to arrive at the transplantation center within a very short, fixed period of time following notification of the availability of suitable organs for transplantation. In addition, patients must maintain compliance with a complicated medication regimen and actively participate in a pulmonary rehabilitation program. Failure to do so typically results in removal from the transplantation list. Prior to undergoing lung transplantation, patients are placed on an aggressive immunosuppressive regimen for the purpose of preventing rejection of the transplanted organ(s), the primary cause of death following transplantation. Other complications of lung transplantation include primary graft dysfunction (typically due to reduced blood supply before/ during transplantation or poor blood circulation in the organ following transplantation); kidney failure which may require dialysis (dialysis is most typically required in patients who had preoperative idiopathic pulmonary fibrosis with pulmonary hypertension);
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malignancy (~10 percent); and bacterial, fungal and viral infections. Lung transplantation involves a major operative procedure and may consist of transplantation of a single lung lobe (more commonly utilized in children), or single- or double-lung transplantation, performed with or without heart transplantation. The underlying condition of the patient, along with his or her indication for transplantation, will determine which surgical transplant procedure is undertaken. Extensive medical monitoring posttransplantation is necessarily performed for the life of the patient. This monitoring includes repeated measurement of lung function, surveillance procedures for rejection, infection, and blood testing. Research is ongoing to determine better methods for soliciting organ donation among diverse population of the United States, prediction of risk for/recognition of and treatment of rejection, and best methods for long-term immunosuppression. SEE ALSO: Chronic Obstructive Pulmonary Disease
(COPD); Cystic Fibrosis; Pulmonary Fibrosis; Sarcoidosis.
Bibliography. M. L. Barr, et al., “Thoracic Organ Trans-
plantation in the United States, 1994–2003,” American Journal of Transplantation (v.5/4, 2005); M. Estenne and R. M. Kotloff “Update in Transplantation,” American Journal of Respiratory and Critical Care Medicine (v.173, 2006); D. S. Wilkes, T. M. Egan, and H. Y. Reynolds, “Lung Transplantation: Opportunities for Research and Clinical Advancement,” American Journal of Respiratory and Critical Care Medicine (v.172, 2005). Sandra K. Willsie, D.O. Kansas City University
Lupus Understanding lupus (also known as systemic lupus erythematosus or SLE) can be a very difficult task because it is such a complex disease. Lupus can affect different organ systems, such as the skin, joints, kidneys, heart, lungs, blood vessels, and brain. Lupus is an autoimmune disease in which the autoantibodies attack different tissues, which can lead to different manifestations. Lupus occurs 10 times more commonly in women than
1038 Lupus in men. It usually occurs in people in their 20s and 30s, and people with certain ethnic backgrounds, especially Asian and African American. The etiology of lupus is unknown, but researchers are still investigating the connection between the environment, genetics, and even hormonal factors as possible causes of the disease. Lupus is described as periods of disease activity, which are called relapses, and periods of alleviation, which is called remission. Flares can be triggered by the exposure to ultraviolet rays, which can cause a malar rash. The cause of the rash has to do with the autoantibodies depositing on self-antigen creating immune complexes deposited in the epidermis, triggering inflammation, which ultimately recruit other immunoregulatory cells. These immunoregulatory cells can release proinflammatory cytokines that can induce tissue damage or cause deposition of immune complexes. This can manifest as malar rash or rash anywhere on the body, severe arthralgias, persistent weakness, involuntary weight loss, involuntary hair loss, high fever, and blood in the urine, to name a few. The diagnosis of lupus is based on criteria developed by the American College of Rheumatology (ACR) to help distinguish the severity of SLE based on clinical symptoms. To be diagnosed with SLE, a patient must have four or more of the 11 criteria to qualify for the classification category of SLE: 1) Malar rash: Fixed rosy rash, usually flat or raised over the cheekbones, sparing the upper lip region. The malar rash is sometimes referred to as the “butterfly rash.” 2) Discoid rash: Reddish, rosy patches with keratotic scaling anywhere on the body. 3) Photosensitivity: Skin rash due to exposure to ultraviolet rays observed by the patient or physician. 4) Oral ulcers: Painless ulcers in the mouth, nose, or throat lasting more than two weeks observed by the physician and or patient. 5) Arthritis: Tenderness, swelling, or effusion affecting joints without causing joint erosion. To include this criterion, the patient has to have arthritis affecting two or more peripheral joints. 6) Serositis: Inflammation of the tissue sac surrounding the lungs (pleuritis) or the heart (pericarditis).
7) Renal disorder: Persistent loss of protein in the urine (proteinuria) greater than 0.5 g per day and as high as 3 g per day. The presence of proteinuria can be determined by the physician. The involvement of the kidneys can be further categorized by the World Health Organization stages. The stages range from one to four, stage one being mild involvement of immune complexes depositing in renal tissue. Stage four is categorized as being the most severe stage of renal involvement, which would be caused by severe damage to renal glomeruli. 8) Neurologic disorder: The presence of seizures, without the cause of seizures being drugs or any metabolic disorder (e.g., uremia, ketoacidosis, or electrolyte imbalances). 9) Hematologic disorder: Hemolytic anemia, any major loss of white blood cells or platelets. 10) Immunologic disorder: Presence of autoantibodies, especially anti-dsDNA, anti-Sm, or anti-phosholipid antibodies. 11) Antinuclear antibody: An abnormal titer of antinuclear antibody (ANA) by immunofluorescence. The diagnosis of lupus is not accomplished by one particular test but by a group of laboratory tests and a thorough medical history. A complete blood count (CBC), erythrocyte sedimentation rate (ESR), urinalysis (UA), blood chemistries, and complement levels are helpful tools in the diagnosis of lupus. The use of the ANA antibody test is sensitive for an autoimmune process but not specific for lupus. Other autoantibodies that are more specific for lupus are anti-dsDNA, anti-Sm, antiRNP, anti-Ro, and anti-La. Other diagnostic tools for lupus that are invasive include, but not limited to, biopsies of the skin and kidney. A primary care physician may be faced with treating a patient’s acute flares or exacerbations of lupus, but more effective management may occur with the help of a rheumatologist. A rheumatologist is a physician specializing in inflammatory disease and autoimmune disorders. The physician’s understanding of the disease and its severity is crucial. Treatments can range from nonsteroidal antiinflammatory drugs (NSAIDs), glucocorticoids, antimalarial drugs, or immunosuppressive drugs such as methotrexate or azathioprine. In lupus, select-
Luxembourg
ing the appropriate type of treatment in patients is imperative. When life or organ threatening, lupus requires an entirely aggressive treatment regimen. The mainstay of treatment for mild-to-severe lupus is high-dose glucocorticoids. If the high doses of glucocorticoids are not managing the lupus or the response is inadequate, the addition of cytotoxic/immunosuppressive drugs can help prevent any further organ involvement. In patients who have renal involvement, initial management with immunosuppressive drugs can be of help, but uncontrolled progression of the disease can lead the patient to dialysis or renal transplantation as the only treatment options. Currently, there are studies testing the capability of anticytokine medications to modulate and halt the immunological process. SEE ALSO: Arthritis; Autoimmune Diseases (General). Bibliography. “Systemic Lupus Erythematosus,” www.
rheumatology.org (cited ); Edward D. Harris, et al., eds., Kelley’s Textbook of Rheumatology, 7th ed. (Saunders, 2005); “Systemic Lupus Erythematosus,” U.S. Department of Health and Human Services, http://www.niams. nih.gov/hi/topics/lupus/slehandout/index.htm (cited August 2003). Ahmed S. Samad, M.D. Hoffmann-La Roche Inc.
Luxembourg The Grand Duchy of Luxembourg has a per capita income of $69,900 and shares with Bermuda the title of the richest nation in the world. The economy is extremely healthy, growing at a rate of 4 percent. Inflation (2.5 percent) and unemployment (2.4 percent) are well under control. The economy is diversified, and only 1 percent of the population is involved in agriculture, generally on family farms. Among the workforce of 316,500, 121,600 workers commute from their homelands of France, Belgium, and Germany to take advantage of Luxembourg’s high wages. According to the United Nations Development Programme (UNDP) Human Development Reports, Luxembourg has the 12th highest living standard in the world.
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The population has easy access to healthcare. Most workers enlist in employee-sponsored insurance programs, and many Luxembourgers have supplementary coverage. Social Security is financed by mandatory contributions from workers and employer and supplemented by the government. The program covers the elderly, the disabled, survivors, maternity benefits, those suffering from illnesses, injured workers, and the economically disadvantaged. On average, 13 percent of Luxembourg’s budget is targeted for health. Around seven percent (6.8 percent) of the Gross Domestic Product (GDP) is used to fund health programs, with an allotment of $3,680 (international dollars) per capita. As a percentage of total health spending, the government furnishes 90.8 percent, with 88.1 percent of that amount earmarked for Social Security. Of the 10 percent of private sector spending on healthcare, 77.30 percent is derived from out-of-pocket expenses. There are 2.66 physicians, 9.16 nurses, 0.24 midwives, 0.71 dentists, and 0.82 pharmacists per 1,000 population in Luxembourg. Among the population of 474,413 Luxembourgers, life expectancy is 78.89 years, the 31st highest life expectancy in the world. Females outlive males an average of six years. Literacy is universal, and all of the relevant population is enrolled in primary and secondary school. The entire population has access to safe drinking water and improved sanitation. Generally, women give birth to 1.78 children each, and all births are attended by trained personnel. The adjusted maternal mortality rate of 28 deaths per 100,000 live births is somewhat higher than might be expected in a country with such a high living standard. Infant mortality occurs at a rate of 4.74 deaths per 1,000 live births, the 26th lowest ranking in the world. Between 1990 and 2004, life expectancy in Luxembourg was reduced from seven births per 1,000 live births to five. During the same period, the under-5 mortality rate fell from 10 deaths per 1,000 live births to six. Despite general good health, 8 percent of infants are underweight at birth. Childhood immunization rates are predictably high in Luxembourg: 98 percent against diphtheria, pertussis, and tetanus (DPT1 and DPT3) and polio, 91 percent against measles, and 86 percent against Haemophilus influenzae type B. However, less than half of all infants are immunized against hepatitis B.
1040 Lyme Disease Environmentally, industrialization has affected general health through air and water pollution, and soil pollution presents difficulties in farming areas. HIV/AIDS does not present a major problem in Luxembourg, which has a 0.2 percent adult prevalence rate. Around 500 people are living with the disease, and less than 100 have died from HIV/AIDS or its complications. A number of programs have been implemented to improve the health of infants, children, women, and the elderly, and preventive health is emphasized. The leading causes of death are cardiovascular diseases and cancer. Luxembourg’s death rate from external causes is one of the highest among members of the European Union, but rates have been cut by around 35 percent over the past two decades. SEE ALSO: Healthcare, Europe. Bibliography. A. B. Atkinson, Incomes and the Welfare
State: Essays on Britain and Europe (Cambridge University Press, 1995); Central Intelligence Agency, “Luxembourg,” World Factbook, https://www.cia.gov/cia/publications/ factbook/geos/lu.html (cited July 2007); Commission on the Status of Women, “Luxembourg,” http://www.un.org/ womenwatch/daw/Review/responses/LUXEMBOURGEnglish.pdf (cited ); Spencer Di Scala, Twentieth Century Europe: Politics, Society, Culture (McGraw-Hill, 2004); Sandra Halperin, War and Social Change in Modern Europe: The Great Transformation Revisited (Cambridge University Press, 2004); Martin A. Levin and Martin Shapiro, eds., Transatlantic Policymaking in an Age of Austerity: Diversity and Drift (Georgetown University Press, 2004); Jeremy Rifkin, The European Dream: How Europe’s Vision of the Future Is Quietly Eclipsing the American Dream (Jeremy P. Tarcher/Penguin, 2004); Peter TaylorGooby, New Risks, New Welfare: The Transformation of the European Welfare State (Oxford University Press, 2004); United Nations Children’s Fund, “Luxembourg,” http://www.unicef.org/infobycountry/luxembourg_statistics.html (cited July 2007); World Bank, “Luxembourg Data Profile,” http://devdata.worldbank.org/external/CPProfile.asp?PTYPE=CP&CCODE=LUX (cited July 2007); World Health Organization, “Luxembourg,” http://www. who.int/countries/lux/en/ (cited July 2007). Elizabeth R. Purdy, Ph.D. Independent Scholar
Lyme Disease Lyme disease, as termed in the United States, or Lyme borreliosis as it is known in Europe and Asia, describes an infection of the Borrelia strain of bacteria. The primary symptoms, encompassing skin, heart, neurologic, and joint abnormalities, were first linked to the Ixodes tick in the early 1980s. The disease is successfully treated through oral and intravenous antibiotic therapy, although in some cases, symptoms do persist. With 15,000 reported cases annually in the United States alone, Lyme disease represents the most common tick-borne disease in the United States and Europe. The disease is most prevalent in the northern United States, and in heavily forested areas of Europe, such as Germany, Austria, Slovenia, and Sweden. Causes Lyme disease is caused by Borrelia burgdorferi, Borrelia afzelii, and Borrelia garinii, all belonging to the bacterial phylum of corkscrew-shaped spirochaete. In the United States, only cases of B. burgdorferi have been reported; in Asia, only B. afzelii and B. garinii; in Europe, all three types of the infection are present, although the latter two are more common. There are slight clinical differences between the symptoms of the United States version and the infection typical of Europe. In all regions, the bacterium is transmitted through Ixodes ticks. This type of tick is commonly known as a deer tick in the United States, where the increased incidence of Lyme disease in the last few decades has coincided with an increase in the deer population. Deer represent a medium to transport and maintain the tick population, as they are not infected by the disease. The Ixodes tick has three active feeding stages as a larvae, nymph, and adult. Typically, an uninfected larval Ixodes tick acquires the spirochaete along with its blood meal while feeding on an infected vertebrate, and then transmits it during its nymphal feeding stage to an uninfected human or other vertebrate. Thus, the majority of human cases occur between late spring and early summer, when nymphs are most active. Recent molecular and genetic analysis of the causative bacterium aims to reveal additional information behind the mechanisms of infection and transmission.
Symptoms The early stage of the infection by the spirochaete begins at the site of the tick bite as an expanding round or oval skin lesion, known as erythema migrans. Erythema migrans in the United States is characterized by more severe inflammation and dissemination than in Europe and Asia, where the lesions are milder but persist for a longer period of time. This first stage is usually accompanied by an array of flu-like symptoms including malaise, fatigue, headache, fever, chills, and swollen lymph nodes. The second stage of the illness involves the spread of the infection to the heart, nervous system, and joints. Most patients are treated before progressing to this stage and experiencing such symptoms. In 5 percent of those untreated patients, however, heart complications occur within several weeks of infection. The most common problem includes various degrees of atrioventricular block. Occasionally, patients also experience dysfunction in the left ventricle and inflammation of the heart wall. Additional cardiac symptoms in certain Asian and European cases include chronic, persistent problems with cardiac muscle. Signs of neurological infection appear in 15 percent of untreated patients in the United States. Earlier phases of the disease are associated with cranial neuropathy, while later phases involve peripheral neuropathy and encephalitis. Neurologic impacts common to American cases include meningitis, severe headache, mild neck stiffness, and inflammation of the spinal cord and brain. Cases of Europe and Asia are characterized by more severe inflammation and pain in the spinal cord, brain, and spinal nerves while headache and neck stiffness tend to be milder. Other general neurological symptoms of the disease include unsteadiness in movement, facial palsy, memory loss, and vision problems. In children, the brain inflammation and increased intercranial pressure can also put pressure on the optic nerve, and potentially lead to blindness. Joint abnormalities represent the most prevalent manifestations of Lyme disease. Over 60 percent of untreated patients in the United States experience swelling and pain in their joints, particularly in large joints as the knee. This can be attributed to the high concentration of the immune system’s borrelia-specific inflammatory response in joint fluid, which overwhelms the presence of antiinflammatory immune system cells (cytokines). Affected patients also display
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synovial hypertrophy and vascular proliferation in the joint fluid. Genetic factors, specifically differences in innate immune system responses, frequently influence the severity of the arthritis. In North America, such arthritic attacks are accompanied by more acute joint inflammation in comparison to European and Asian cases. The arthritis tends to be resistant to prolonged treatment in roughly 10 percent of American patients, whereas in Europe and Asia, persistent arthritis is rare. It is suspected that the treatment-resistant arthritis is cased by some autoimmune mechanism. Diagnosis Lyme disease is definitively diagnosed through a bacterial culture. In the North American infections of B. burgdorferi, successful cultures are typically obtained early from erythema migrans lesions. Less frequently, physicians can use plasma or cerebrospinal fluid to develop a culture if the disease has spread that far. In these later stages, testing utilizing polymerase chain reaction (PCR) is more effective than a culture. In the United States, most diagnoses are based on clinical findings, history of possible exposure, and antibody testing. Clinical findings are considered insufficient for a diagnosis of infection beyond the skin. With B. afzelii and B. garinii related infections, the antibody response is more localized, so the disease is more difficult to diagnose. Treatment Patients are usually treated within the first stage of the disease with a course of antibiotics. For early or localized infection, treatment with doxycycline for 14 to 21 days is recommended in patients older than 8 years of age, with the exception of pregnant women. For these two groups, amoxicillin represents the next alternative for treatment. The third-choice alternative is cefuroxime axetil. For patients with neurologic symptoms, a 14 to 28day course of intravenous ceftriaxone is the most common method of treatment. Acute symptoms of neurological infection resolve within weeks while chronic symptoms improve over the course of months. Relapse is rare after a four-week course of intravenous therapy. Both the oral doxycycline and intravenous ceftriaxone are effective treatments for patients with arthritic symptoms. However, even after such treatment, approximately 10 percent of American patients continue
1042 Lymphatic Diseases to experience joint inflammation for months or years after therapy. The number is much lower in European and Asian cases. After all types of treatment, a small percentage of patients still report a number of subjective symptoms including musculoskeletal pain, neurocognitive difficulties, and fatigue. This collection of symptoms is sometimes termed chronic Lyme disease or post-Lyme disease syndrome. The exact cause of these prolonged symptoms is not known, but some evidence suggests it stems from an autoimmune response that persists even after the infection has been cleared. Antibiotic therapy is not typically effective against this affliction, so physicians tend to treat patients symptomatically. A number of preventative measures can help reduce the incidence of Lyme disease. Such measures include wearing protective clothing and repellents in tick-infested areas, as well as avoiding tick-infested areas altogether. Thorough checks for tick bites after entering such areas can also help prevent infection, as the tick often must remain attached to its human host for 24 hours before the bacterium can be transmitted. A vaccine has also been developed, recommended for individuals between 15 and 70 years of age who live in high-risk areas. The vaccine is effective in preventing 49 percent of cases after two injections, and 76 percent after three injections. SEE ALSO: Arthritis; Infectious Disease (General); Men-
ingitis.
Bibliography. Centers for Disease Control and Preven-
tion, “Learn about Lyme Disease,” http://www.cdc.gov/ ncidod/dvbid/lyme/index.htm (cited December 2006); Patricia Rosa, Kit Tilly, and Philip Stewart, “The Burgeoning Molecular Genetics of the Lyme Disease Spirochaete,” Nature Reviews Microbiology (v.3, 2005); Allen Steere, “Lyme Disease,” New England Journal of Medicine (v.345, 2001); Allen Steere, et al., “The Spirochetal Etiology of Lyme Disease,” New England Journal of Medicine (v. 308/13, 1983); Gary Wormser, et al., “The Clinical Assessment, Treatment, and Prevention of Lyme Disease, Human Granulocytic Anaplasmosis, and Babesiosis: Clinical Practice Guidelines by the Infectious Diseases Society of America,” Clinical Infectious Diseases (v.43, 2006). Neha Sathe New York University
Lymphatic Diseases The lymphatic system is essential in maintaining the fluid balance in the body as well as being an important part of the body’s immune defense. Today, there are millions of people worldwide suffering from or developing diseases related to the lymphatic such as lymphedema, acute lymphangitis, and lymphadenitis. In addition, the lymphatic system is also involved in the pathogenesis of diseases such as cancer and various inflammatory conditions. Functions The role of the blood vessels is to deliver oxygen and nutrients to different tissues where the molecular exchange of these compounds take place in capillaries. As blood moves through the tissues, blood pressure causes plasma to leak out from the capillaries into the surrounding tissues. This excess fluid, which is rich in protein, is then collected by the lymph system and returned to the circulatory system through the two subclavian veins under the collarbones. Consisting of lymph, lymphatic nodes, and lymphatic vessels, the lymphatic system also plays important roles besides keeping the fluid balance in homeostasis. Located throughout the body, lymphatic vessels have valves like those in veins to keep lymph flowing in one direction. Before returning back to the blood circulation, damaged cells, cancer cells, and foreign particles that might be present in the lymph are filtered out through the lymph nodes and destroyed by blood cells specifically made to initiate immune responses. As a result, the lymphatic system is important in removing damaged cells from the body and in protecting against the spread of infection and cancer cells. Furthermore, the lymphatic vessels located in the small intestine absorb dietary fat from food. Abnormality in the lymphatic system in the intestine can lead to malnutrition or excessive obesity. Lymphedema The lymphatic system might not function properly when there is excessive quantity of fluid or if there is a blockage of the lymph vessels or nodes because of a tumor or inflammation. The most prevalent lymphatic disease is lymphedema, which occurs when there is a buildup of excessive lymph fluid and swelling resulting in obstruction and destruction of lymph vessels. Lymphedema is caused by an abnormality preventing
lymph from being reabsorbed into the capillaries and drained from the tissues. The severity of this disease varies from very mild to a painful and debilitating state, and it remains a lifelong functional problem requiring daily treatment. Lymphedema may be either primary (congenital) or secondary (acquired). Primary lymphedema is an inherited condition more frequently seen in women. It occurs when the lymphatic vessels are either absent or impaired, resulting in swelling observed more commonly in the legs. Primary lymphedema can be present from birth (congenital lymphedema), occur during puberty (lymphedema praecox), or develop later in adult life (lymphedema tarda) either with unknown causes or associated with other vascular or lymphatic anomalies. The first indication of lymphedema may be swelling of the foot resulting in tightness in the shoe. Secondary lymphedema is a common problem among adults and children, and it is acquired through infection or after major surgery or radiotherapy in which lymphatic tissues are removed. It is more common than primary lymphedema. One example of secondary lymphedema is lymphatic filariasis, a condition caused by microscopic parasites called filaria affecting hundred of millions of people worldwide. Patients with filariasis suffer from lymphedema in the arms, breast, and legs that might swell to several times their original size. Moreover, patients are more susceptible to further infections due to impaired lymph system. In rare situations, the swollen limb becomes extremely enlarged and the skin is so thickened and ridged that the infected area resembles elephant skin—this is a condition called elephantiasis that can be treated by an extensive operation to remove the swollen tissues under that skin or by antibiotics. �������������������������������������������� There is no cure for patients with lymphedema. For people with mild lymphedema, the swelling can be reduced applying compression bandages. People who have more severe condition may have to wear pneumatic compression to reduce and control the swelling. Lymphangiosarcoma Lymphangiosarcoma is a rare and malignant tumor occurring in patients with long-standing primary or secondary lymphedema. It is most common in the upper extremities. The sarcoma or the cancer of connective or supportive tissue initially appears as a bruised area and progresses to necrosis or death of the skin and underlying tissues. It can metastasize widely and quickly. There is presently no effective therapy.
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Acute Lymphangitis The usual cause of acute lymphangitis is usually through infection of Streptococci bacteria that results in acute inflammation of the lymphatic vessels. These bacteria commonly enter the lymphatic vessels via an abrasion or wound in an arm or a leg. Often, a streptococcal infection such as cellulitis in the skin and the tissues underneath spreads along the lymph vessels, which become inflamed. Occasionally, other bacteria such as Staphylococci and Pseudomonas are the cause. The diagnosis is based on symptoms where red and irregular streaks developing under the skin spreading from the affected area toward regional lymph nodes such as in the groin or armpit. There is usually throbbing pain along the affected area. If the infection is disseminated into the bloodstream, further infection can quickly spread through the whole body. A blood test usually shows an increased number of white blood cells to fight the infection. In most cases, this disease can be managed with antibiotics to kill Staphylococci and Streptococci. Lymphadenitis Lymphadenitis involves inflammation of the lymph nodes. It is caused mostly by an infection due to bacteria, virus, or fungi that develop within lymph nodes. Alternatively, it could be a result of cancer cells in circulation or other inflammatory conditions. Infected lymph nodes are usually enlarged and tender due to edema and white blood cell infiltration with occasional redness of skin overlying the affected nodes. Occasionally, the skin might be inflamed, reddened, and hot. Patients with enlarged lymph nodes who do not feel pain or redness might present with a serious disorder such as lymphoma, tuberculosis, or Hodgkin’s disease. Usually, lymphadenitis can be identified based on the symptoms and the nearby infection. However, when the cause cannot be confirmed, a biopsy that removes a tissue sample for examination under a microscope and culture may be needed to determine the organism causing the infection and to help with diagnosis and treatment with specific antibiotic given intravenously or orally. Lymphangioma Lymphangiomas are uncommon malformations of the lymphatic system involving the skin and underlying tissues. Lymphangiomas can occur anywhere in the skin and the mucous membranes usually on the
1044 Lymphatic Diseases head and the neck. Although no treatment is usually needed, lymphangioma can be removed surgically, but recurrence after surgery is common. Lymphangioleiomyomatosis Lymphangioleiomyomatosis (LAM) is a rare lung disease affecting mostly women usually during their childbearing years. Characterized by unusual muscle cells that invade and grow out of control into tissues of the lungs including the airways, and blood and lymph vessels causing obstruction. This blocks the flow of air, blood, and lymph vessels to and from the lungs hindering their functions of providing oxygen to the rest of the body. In early stages of the disease, patients with LAM experience shortness of breath with physical activity; however, as the disease advances, there may be shortness of breath even at rest. Other common symptoms include chest pain, cough, fatigue, and collapsed lung, which is common in LAM patients. There is currently no cure for LAM, but treatments such as estrogen reduction and oxygen therapy have been applied to patients with varying degrees of effectiveness. Lung transplantation is another option but offered as a last resort. Autoimmune Lymphoproliferative Syndrome Autoimmune lymphoproliferative syndrome (ALP) is a rare genetic disease affecting both children and adults. It is developed in early childhood and there is varying degree of severity among patients. Most ALP patients will develop autoimmune (self-immune) problems such as very low red blood cell, white blood cell, and platelet counts due to self-generated antibodies attaching to these cells to form complexes. The buildup of these immune complexes in tissues causes inflammation and injuries. The spleen is also required to work overtime to filter out these complexes. Although there is no cure for ALP, there are treatments, such as steroids, available for autoimmune problems. Lymphoma Lymphoma is a general term describing a group of cancers arising in the lymphatic system when lymphocytes, the infection-fighting white blood cells, become malignant and proliferative. It is divided into two major categories: Hodgkin’s disease and all other
lymphomas called non-Hodgkin’s lymphomas (NHL). The majority of patients have NHL. These two types of lymphoma can be distinguished by viewing cancer cells under the microscope. The cellular morphology of these two kinds of cancer cells is distinct: Hodgkin’s disease is characterized by the presence of ReedSternberg cells believed to be a type of malignant B lymphocytes that normally make antibodies that help fight infections. Hodgkin’s disease is one of the most curable forms of cancer using radiation, chemotherapy, or a combination of both. NHL is not a single disease but a group of many closely related cancers affecting the lymphatic system. There are over 29 types of NHL, each is distinct from one another because of the type of cancer cells. NHL is divided into two major groups: B-cell lymphomas (which develop from abnormal B lymphocytes) and T-cell lymphomas (which develop from abnormal T lymphocytes). Almost 90 percent of NHL is B-cell lymphomas. Treatment plans for patients take into consideration the types of NHL as well as other factors such as growth rate of the tumor cells and the stage of disease. Castleman Disease First described in 1956 by Dr. Benjamin Castleman in Boston, Castleman disease is a disease of lymph nodes and related tissues. It is not a cancer but a lymphoproliferative disorder that describes the overgrowth of the lymph nodes that is similar to lymphomas and treated like a cancer using radiotherapy and chemotherapy. There are two forms of Castleman disease: localized and multicentric. Localized Castleman disease affects only a single lymph node commonly found in the chest and abdomen. The affected node becomes enlarged and may put pressure on other organs. Patients with this type of Castleman disease can usually be cured with treatment. Multicentric Castleman disease is more serious and affects more than one group of lymph nodes and may also affect other lymphoidcontaining organs. This form sometimes occurs in people infected with human immunodeficiency virus (HIV). People with this type of disease often develop serious infection due to weakened immune system as well as malignant lymphomas. SEE ALSO: AIDS; Bacterial Infections; Cancer (General);
Cellulitis; Chemoradiotherapy; Chemotherapy; Digestive
Diseases (General); Filariasis/Elephantiasis; Head and Neck Cancer; Hematology; Hodgkin’s Lymphoma; Immune System and Disorders; Non-Hodgkins Lymphoma; Obesity; Oncology; Skin Cancer; Skin Diseases (General); Staphylococcal Infections; Streptococcal Infections; Viral Infections.
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Bibliography. Mark H. Beers, Robert S. Porter, and
Thomas V. Jones, eds., The Merck Manual of Diagnosis and Therapy, 18th ed. (Merck Research Laboratories, 2006). Stephen Chen University of Toronto
M Macedonia (FYROM) Macedonia is located on the Balkan Peninsula in southeastern Europe. It is a landlocked republic, surrounded by Greece, Albania, Serbia and Bulgaria. Macedonia is one of the new states to emerge from the dissolution of Yugoslavia in the 1990s, but unlike some of the other former states, its transition to independence was peaceful. Greece objected to the use of the name on historical and territorial grounds, so the United Nations provisionally calls it the “Former Yugoslav Republic of Macedonia,” often shortened to FYROM. The population is 2,056,000 and growing at 0.263 percent annually. The birth rate is 12.02 per 1,000 and the death rate is 8.78 per 1,000. Median age is 34.4 years. Life expectancy is currently 71.73 years for males and 76.88 years for females. Gross national income is $2,830. Macedonia is the poorest of the new Balkan states, with 30 percent overall poverty. The economy is growing at a slow pace. Mortality from parasitic or infectious diseases is very low, accounting for only eight deaths per 100,000. The tuberculosis rate, at 32 new cases per 100,000, has fallen by half since 2001, although it is still twice the European Union average. Macedonia’s adult prevalence rate for HIV/AIDS is barely measurable at un-
der 0.1 percent of the population. The country also has a extremely low rate of sexually transmitted diseases, with 0.1 cases per 100,000. Cardiovascular disease is the main cause of morbidity in Macedonia, accounting for 58 percent of all deaths. Cancer is next, at 16 percent of annual deaths. Surveys have found that 40 percent of males and 32 percent of females are regular smokers. About 25 percent of all adult women are obese, along with 6 percent of men. However, consumption of alcohol is very low, at just 2 litres per person per year, well under the EU average of 9.4 liters. Illegal drug use rare. Child mortality is low at 15 per 1,000 for infants and 17 per 1,000 for children under 5. Immunization rates are 92 percent or higher. Overall nutrition is good. School enrollment is around 95 percent. However, Roma (gypsy) Macedonians, who account for about 2.7 percent of the total population, have a much poorer health profile, beginning in childhood. Roma children have higher mortality rates, are less likely to be well-nourished or have access to immunization or regular healthcare, and are less likely to receive an education. About 10 percent of Roma children are never registered for school, and many girls drop out early to marry. Women in Macedonia are believed to suffer from high rates of domestic violence, although there is little
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1048 Madagascar statistical data on the subject. The maternal mortality rate is 23 deaths per 100,000 live births. Almost all births are attended, although Roma women do not get the same level of prenatal care and generally give birth at home, and mother and child mortality in Roma communities may be underreported. Primary healthcare is provided through a network of about 1,200 units dispersed around the country. Rural community clinics are supplemented by services at healthcare centres in larger towns. There are 16 general hospitals, six rehabilitation centers, six specialized hospitals and a university hospital providing inpatient or tertiary care, clustered in major cities. All technologically advanced procedures are done in the capital city of Skopje. See also: Healthcare, Europe, Women’s Health (General). Bibliography. “Macedonia (The Former Yugoslav Re-
public of )” CIA World Factbook, www.cia.gov (cited July 2007); UNAIDS: The Joint United Nations Programme on HIV/AIDS, “Macedonia (The former Yugoslav Republic of ),” www.unaids.org/en/ (cited July 2007); UNICEF, “The Former Yugoslav Republic of Macedonia—Country Website,” www.unicef.org (cited July 2007); UNICEF, “The Former Yugoslav Republic of Macedonia: Statistics,” www. unicef.org/infobycountry (cited July 2007); World Health Organization, “Health Care Systems in Transition: The Former Yugoslav Republic of Macedonia,” www.euro.who. int/ (cited July 2007); World Health Organization, “The Former Yugoslav Republic of Macedonia: 10 Health Questions About the New EU Neighbors,” www.euro.who.int/ Document/E88202_FYRMakedonia.pdf (cited July 2007). Heather K. Michon Independent Scholar
Madagascar Madagascar is a island nation located southeast of Africa, separated from the coast by the wide Mozambique Channel. It is the fourth largest island in the world. Its tropical forests are home to a dazzling amount of biodiversity, with an estimated 200,000 species of plants and animals found nowhere else on the planet. Today, this remarkable world is threat-
ened by the growing pressures of a large and povertystricken society. The population of Madagascar currently stands at 18.6 million, growing at 3 percent annually. This growth is the result of natural increase: the birth rate is 41.41 per 1,000 people, and the death rate 11.11 per 1,000 people. Only 26 percent of the people live in urban areas, and the population density is 32 people per square kilometers. Madagascar’s economy has long relied on agricultural exports, including coffee, vanilla, cloves, and prawns, employing 80 percent of the workforce. Per capita income is $300 a year, and 61 percent of all Malagasys live on $1 a day or less. Environmental problems have tremendous impact on the health of Malagasys. The island is subject to cyclones and has suffered from recurrent droughts and locust swarms in recent years. Ninety percent of the forests are gone, and each year 25 to 30 percent of the land burns as farmers clear their fields for the planting season. Only 5.03 percent percent of the land is arable; soil erosion has become a serious problem in many areas. In 2006, many of the country’s staple crops—including sweet potatoes, manioc, and rice—failed or returned poor yields, leading to food insecurity in the southern part of the island. At least 70 percent of the population is malnourished. Life expectancy at birth is 54.93 years for males and 59.82 years for females, with healthy life expectancy at 47.3 years for men and 49.9 years for women. Infant mortality is 75.21 deaths per 1,000 live births; 123 of every 1,000 children die before their fifth birthday. Maternal mortality is also high, with 550 deaths for every 100,000 live births. Only 80 percent of women receive prenatal care, and only 51 percent of deliveries are monitored by a trained attendant. Less than 30 percent of women use birth control, and the average woman will give birth to six children in her lifetime. The United Nations Children’s Fund (UNICEF) calculates that 160 Malagasy children die each day from preventable diseases including malaria and diarrhea. Immunization programs receive no government funding, and despite the efforts of nongovernmental organizations (NGOs), only about 60 percent of children are vaccinated against polio, measles, and hepatitis B; around 70 percent are protected from diph-
Maintenance Medication 1049
theria, pertussis, tetanus, or tuberculosis. A fifth of all Malagasy children work, often in dangerous industries such as mining or stonecutting. Rates of sexual and physical abuse are high. sanitation Sanitary conditions are minimal, with only 45 percent of the population having access to clean drinking water and only 33 percent with sanitary facilities. In this environment, water- and vector-borne diseases flourish, leading to high rates of bacterial and protozoal diarrhea, malaria, typhoid, hepatitis A, schistosomiasis, and regional outbreaks of plague. Recent years have brought outbreaks of cholera, influenza, and polio, but malaria remains the chief infectious killer, with 1.4 million cases and 30,000 deaths reported in 2000 alone. The government has launched an eradication program. The infection rate for HIV/AIDS is 1.7 percent, and well over 140,000 Malagasys are currently living with the virus. By 2003, an estimated 7,500 people had died of AIDS-related causes. UNICEF says that five children a day are born HIV-positive; over 30,000 children have already been orphaned. The Ministry of Health has developed an educational campaign aimed at stemming the tide of the virus, but it has not yet resulted in a noticeable drop in infections. The major hospitals are confined to the capital city of Antananarivo and the quality of service varies from facility to facility. Outside the cities, medical care of any kind is hard to come by. There are perhaps 1,000 small health posts scattered throughout the countryside, and NGOs do have a strong presence in the country. The World Health Organization estimates that there are 5,200 physicians and 5,661 nurses trying to meet the needs of more than 18 million people.
Maintenance Medication Maintenance medication is essentially medication which is used to stabilize an illness or symptoms of an illness. Although technically this definition can include stabilizing a patient with a fracture, the term maintenance medication is used to refer to medical professionals dealing with an illness such as clinical depression or schizophrenia, or withdrawal from drugs, where after initial treatment, rather than continuing the therapy at a high level, the stabilization of a patient for a significant period of time may, in itself, help with the final cure. The actual treatment is sometimes called maintenance therapy. In cases of clinical depression, maintenance medication was often used after electroconvulsive
SEE ALSO: AIDS; Healthcare, Africa. Bibliography. Ruth Evans, “Madagascar Biodiversity
Threatened,” BBC News, http://news.bbc.co.uk/1/hi/ world/africa/1761893.stm (cited April 2007); “Madagascar,” The World Factbook, www.cia.gov/cia/publications/ factbook/geos/ma.html (cited April 2007). Heather K. Michon Independent Scholar
Maintenance medication is medication which is used to stabilize an illness or symptoms of an illness.
1050 Malaria therapy in order to help lessen the after-effects of the initial treatment and yet increase the rate of recovery from the time which might have been taken by use of antidepressants. In a 1991 study of 101 schizophrenia patients by staff from the Department of Psychiatry, State University of New York, Buffalo, showed a relatively non-significant difference in relapse rates between those given maintenance medication and those only intermittently treated. This led to increased research on whether other forms of drugs could be used for more effective maintenance medication. By contrast, a 2006 study, concerning asthma, covered 3415 patients, and showed significant problems which occurred with maintenance medication. These largely hinged on patients selfmedicating—taking the drugs when they felt they needed to—and also occasionally a worsening of the problem during the period of maintenance therapy. It also highlighted problems in mis-diagnosis leading to maintenance therapy becoming ineffective. However with the increase in narcotics, a new important use of maintenance medication has been in treatment of people addicted to particular narcotics, whereby maintenance medication is used to reduce the withdrawal symptoms. This has proven to be effective, with detailed maintenance medication programs drawn up, and after the initial treatment, the patient is stabilised for as long a period of time as possible. This use of maintenance medication such as methadone, has been shown to be effective in many instances, and now much medical research is now being directed towards maintenance medication, with work on testing and trials of specific drugs which will help alleviate the relapse vulnerability of many patients. See also: Pharmaceutical Industry (Worldwide). BIBLIOGRAPHY. M.I. Herz, et al., “Intermittent vs Main-
tenance Medication in Schizophrenia: Two Year Results,” Archives of General Psychiatry (v.48/4, April 1991); D.A. Johnson, “Antipsychotic Medication: Clinical Guidelines for Maintenance Therapy,” Journal of Clinical Psychiatry (v.46/5, May 1985); R. Manchanda and S.R. Hirsch, “Low Dose Maintenance Medication for Schizophrenia,” British Medical Journal (v.293, no, 6546, August 30, 1986); Martyn R. Patridge, Thys van der Molen, Sven-Erik Myrseth and William W. Busse, “Attitudes and Actions of Asthma
Patients on Regular Maintenance Therapy: the INSPIRE Study,” BMC Pulmonary Medicine (v.6, 2006). Justin Corfield Geelong Grammar School, Australia
Malaria Malaria is a life-threatening parasitic disease transmitted by mosquitoes. The term malaria originates from Medieval Italian, mala aria (bad air) due to its association with swamps. In 1880, scientists discovered the real cause of malaria, a one-cell parasite called plasmodium. Later, they discovered that the parasite is transmitted from person to person through the bite of a female Anopheles mosquito, which requires blood to nurture her eggs. Today, approximately 40 percent of the world’s population—mostly those living in the world’s poorest countries—are at risk of malaria. The disease was once more widespread but it was successfully eliminated from many countries with temperate climates during the mid-20th century. Now, malaria is found throughout the tropical and subtropical regions of the world and causes more than 300 million acute illnesses and at least 1 million deaths annually. It is endemic in parts of Asia, Africa, Central and South America, Oceania, and certain Caribbean islands. Malaria, together with human immunodeficiency virus (HIV)/AIDS and tuberculosis, is one of the major public health challenges undermining development in the poorest countries in the world. Malaria is caused by protozoan parasites of the genus Plasmodium (phylum Apicomplexa). In humans, malaria is caused by P. falciparum, P. malariae, P. ovale, and P. vivax. However, P. falciparum is the most important cause of disease and responsible for about 80 percent of infections and 90 percent of deaths. P. falciparum malaria is most common in Africa, south of the Sahara, accounting in large part for the extremely high mortality in this region. The malaria parasite enters the human host when an infected Anopheles mosquito takes a blood meal. Inside the human host, the parasite undergoes a series of changes as part of its complex life cycle. Its various stages allow plasmodia to evade the immune system,
infect the liver and red blood cells, and finally develop into a form that is able to infect a mosquito again when it bites an infected person. Inside the mosquito, the parasite matures until it reaches the sexual stage where it can again infect a human host when the mosquito takes its next blood meal, 10 to 14 or more days later. Malaria symptoms appear about nine to 14 days after the infectious mosquito bite, although this varies with different plasmodium species. It is characterized by extreme exhaustion associated with paroxysms of high fever, sweating, shaking chills, and anemia. If drugs are not available for treatment or the parasites are resistant to them, the infection can progress rapidly to become life threatening. Malaria can kill by infecting and destroying red blood cells (anemia) and by clogging the capillaries that carry blood to the brain (cerebral malaria) or other vital organs. Malaria in Africa Around 90 percent of the over 1 million malaria-associated deaths occur in Africa, mostly in young children. Malaria is Africa’s leading cause of under5 mortality (20 percent) and constitutes 10 percent of the continent’s overall disease burden. Malaria has been estimated to cost Africa more than $12 billion every year in lost Gross Domestic Product (GDP), even though it could be controlled for a fraction of that sum. It accounts for 40 percent of public health expenditure, 30 to 50 percent of inpatient admissions, and up to 50 percent of outpatient visits in areas with high malaria transmission. Reasons why Africa bears an overwhelming proportion of the malaria burden include the fact that most malaria infections south of the Sahara are caused by P. falciparum, the most severe, efficient, and life-threatening form of the disease. Moreover, many countries in Africa lack the infrastructures and resources necessary to mount sustainable campaigns against malaria, and as a result, few benefit from efforts to eradicate malaria. In most endemic areas of the world, pregnant women are the main adult risk group for malaria. Every year, at least 30 million pregnancies occur among women in malarious areas of Africa, most of whom reside in areas of relatively stable malaria transmission. Intermittent preventive treatment (IPT) involves providing all pregnant women with at least two preventive treatment doses of an effective antimalarial drug
Malaria
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during routine prenatal clinic visits. This approach has been shown to be safe, inexpensive, and effective. Insecticide-Treated Mosquito Nets Most malaria-carrying mosquitoes bite at night. Mosquito nets, if properly used and maintained, can provide a physical barrier to hungry mosquitoes. If treated with insecticide, the effectiveness of nets is greatly improved, generating a chemical halo that extends beyond the mosquito net itself. This tends to repel or deter mosquitoes from biting or shorten the mosquito’s life span so that she cannot transmit malaria infection. Trials of insecticide-treated nets (ITNs) in the 1980s and 1990s showed that ITNs reduced deaths in young children by an average of 20 percent. Unfortunately, ITNs can be expensive for families at risk of malaria, who are among the poorest in the world. Moreover, people who are unfamiliar with ITNs or who are not in the habit of using them need to be convinced of their usefulness and persuaded to re-treat the nets with insecticide on a regular basis. In some areas where mosquito nets are already widely used, it has been estimated that less than 5 percent are re-treated to achieve their expected impact. The World Health Organization has worked with mosquito net and insecticide manufacturers to make re-treatment as simple as possible. However, the best hope lies with newly developed, long-lasting treated nets that may retain their insecticidal properties for four to five years, the life span of the net. Epidemic Prediction and Response Epidemics can occur when malaria attacks vulnerable populations with little or no immunity. In such situations, people of all age groups are at risk of death or severe disease. Epidemics of P. falciparum malaria, the most severe form of the disease, can be devastating if not controlled in a timely manner. The populations most at risk of epidemics are those living in highlands, arid and desert-fringe zones, as well as those living in areas where successful control measures have not been consolidated or maintained. Factors that may precipitate a malaria epidemic fall into two categories: natural (climatic variations, natural disasters), and manmade (conflict and war, agricultural projects, dams, mining, logging). Most of these factors modify the physical environment and
1052 Malariologist increase the capacity of mosquitoes to transmit malaria. Some factors also result in massive population movements that expose nonimmune populations to malaria infection. Drug Resistance and Patterns of Drug Use Key among the factors contributing to the increasing malaria mortality and morbidity is the widespread resistance of P. falciparum to conventional antimalarial drugs, such as chloroquine, sulfadoxine-pyrimethamine (SP), and amodiaquine. Multidrug-resistant falciparum malaria is widely prevalent in southeast Asia and South America. Now, Africa—the continent with the highest burden of malaria—is also affected. Over the past decade, a new group of antimalarials—the artemisinin compounds—have been deployed on an increasingly large scale. These compounds produce a very rapid therapeutic response (reduction of the parasite biomass and resolution of symptoms), are active against multidrug-resistant P. falciparum, are well tolerated by the patients and reduce gametocyte carriage (and thus have the potential to reduce transmission of malaria). To date, no resistance to artemisinin or artemisinin derivatives has been reported, although some decrease in sensitivity in vitro has been detected in China and Vietnam. If used alone, the artemisinins will cure falciparum malaria in seven days, but studies have shown that in combination with certain synthetic drugs, they produce high cure rates in three days with higher adherence to treatment. Furthermore, there is some evidence that use of such combinations in areas with low-to-moderate transmission can retard the development of resistance to the partner drug. Economic Costs of Malaria Finding the financial resources to pay for the greatly increased cost of combination therapy will provide a major challenge for all African countries. And drug costs are likely to feature prominently in future country applications to the Global Fund for HIV, TB, and Malaria. Malaria is not just a disease commonly associated with poverty, but it is also a cause of poverty and a major hindrance to economic development. The disease has been associated with major negative economic effects on regions where it is widespread. A comparison of average per capita GDP in 1995, adjusted to give parity of purchasing power, between
malarious and nonmalarious countries demonstrates a fivefold difference ($1,526 versus $8,268). Moreover, in countries where malaria is common, average per capita GDP has risen (between 1965 and 1990) only 0.4 percent per year, compared to 2.4 percent per year in other countries. See also: Healthcare, Africa; Mosquito Bites. Bibliography. P. A. Holding et al., “Cognitive Sequelae
of Severe Malaria with Impaired Consciousness,” Transactions of the Royal Society of Tropical Medicine and Hygiene (v.93/5, 1999); C. Lengeler, “Insecticide-Treated Bednets and Curtains for Preventing Malaria,” in The Cochrane Library (2002); S. C. Murphy and J. G. Breman, “Gaps in the Childhood Malaria Burden in Africa: Cerebral Malaria, Neurological Sequelae, Anemia, Respiratory Distress, Hypoglycemia, and Complications of Pregnancy,” American Journal of Tropical Medicine and Hygiene (v.64/1–2 Suppl, 2001); D. Schellenberg et al., “Intermittent Treatment for Malaria and Anaemia Control at Time of Routine Vaccinations in Tanzanian Infants: A Randomised, Placebo-Controlled Trial,” Lancet (v.357/9267, 2001); R. W. Snow et al., “Estimating Mortality, Morbidity and Disability Due to Malaria among Africa’s Non-Pregnant Population,” Bulletin of the World Health Organization (v.77/8, 1999); World Health Organization, Antimalarial Drug Combination Therapy: Report of WHO Technical Consultation (World Health Organization, 2001); World Health Organization, Assessment and Monitoring of Antimalarial Drug Efficacy for the Treatment of Uncomplicated Falciparum Malaria (World Health Organization, 2003); World Health Organization, Susceptibility of Plasmodium Falciparum to antimalarial drugs. Report on global monitoring, 1996–2004 (World Health Organization, 2005); World Health Organization, The Use of Antimalarial Drugs (World Health Organization, 2001); World Health Organization, The World Malaria Report (World Health Organization, 2005). Barkha Gurbani University of California, Los Angeles
Malariologist In its more exact definition, a malariologist is a health-science worker dedicated to the study and un-
Malariology
derstanding of malaria and its interacting factors in an integral form. These professionals could be physicians, biologists, pharmaceuticals, laboratorists, nurses, public health bachelors or technicians, sociologists, engineers, environmentalists, and geographers, among others, with significant training and experience, working against malaria, particularly in public health control programs. Charles Louis Alphonse Laveran could well be considered as the first world malariologist. In 1880, he observed moving bodies (gametocytes, sexual stage of the parasite) in fresh blood of a patient with malaria. Other pioneers in the field include a number of noted doctors: H. Meckel, Rudolf Virchow, Göre Frerichs, Robert Koch, Reid Gerhardt, Patrick Manson, Ronald Ross, Amico Bignami, Giovanni Batista Grassi, Julius Wagner-Jauregg, C. Garret-Jones, E.W. Davidson, Camillo Golgi, J. Hamon, Russell MacDonald, William Trager, Leonidas Deane, Arnoldo Gabaldón, Paul Müller, Manuel Patarroyo, B. Galvão, R.G. Damásceno, M.J. Pinto, and Oswaldo Forattini, among others. Four of them have received the Nobel Prize in Medicine for their significant contributions in the malariology science: Ross in 1902, Laveran in 1907, WagnerJauregg in 1927, and Müller in 1948. Today, malariologists still need to do further work, given the current burden of disease, and it is necessary to increase the number of people working against this disease that affects the more uncared for populations in the world. SEE ALSO: Malaria; Malariology; Mosquito Bites; Parasitic
Diseases; Travel Medicine.
Bibliography. Gordon Cook and Alimuddin Zulma,
Manson’s Tropical Diseases (Saunders, 2003); Arnoldo Gabaldón and Arturo Berti, “The First Large Area in the Tropical Zone to Report Malaria Eradication: North-Central Venezuela,” American Journal of Tropical Medicine & Hygiene (v.3/5, 1954); Tulio López, History of the Venezuela’s Malariology School (Venezuela’s Ministry of Health, 1987); Nobel Foundation, “Nobel Prize in Medicine,” nobelprize. org (cited September 2006). Alfonso J. Rodriguez-Morales, M.D. Universidad de Los Andes Carlos Franco-Paredes, M.D. Emory University
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Malariology Malariology is the subject of studying the issues relating to malaria as a major public health issue. It includes, therefore, the ways in which the disease may be transmitted and the inhibition of those transmission routes, the epidemiological issues of the spread of the disease and differing patterns of transmission, as well as the ways in which malaria-bearing mosquitoes may be suppressed. Malaria is a disease spread by parasites from the family of plasmodium, which is passed to humans by mosquito bite. The parasite lives a sexual life cycle inside the mosquito and a second, asexual life cycle within the human (or other bitten creature). The mosquitoes tend to live in swampy areas and, for many centuries, the connection between the disease and the “miasmal air” (bad air or mal-aria) was known. However, it was not until careful scientific experimentation in the 19th century that the role of mosquito and plasmodium parasite was identified. Malaria has spread around most of the world, probably assisted by human exploration as outbreaks were reported in the New World in and around 1493. As Western countries tended to drain and build over swampy regions as part of economic development, it has come to be thought of as a developing-world disease, although it should be noted that it was a significant cause of death in Italy until the 20th century. Annually, there are believed to be around 250 million cases of malaria globally and perhaps 2 million deaths as a result. Treatments based on quinine and other drugs are not effective on a long-term basis and there are many parts of sub-Saharan Africa in which the population is continually infected and reinfected. There are four main types of plasmodium that affect humans and, of these, the most virulent is that which gives rise to falciparun malaria, which requires higher temperatures to thrive and, thus, tends to be more prevalent in the very hot areas in which the poorest people tend to live. Of course, as global climate change continues to intensify, geographical regions in which this form of malaria will prove a threat to human life will spread to more affluent areas. Hence, the disease will be less easy for people in such countries to ignore in the future. Indeed, because people will have had less opportunity to develop any form of immunity or resistance, the fatality rate might increase.
1054 Malawi Malariology provides three main approaches to controlling the spread of the disease. The first is vector control, which entails suppressing the parasites and/or the mosquitoes in which they live. The second relates to chemotherapy and provides drugs both to prevent infection and to reduce the impact of infection once it should have struck. The third is through vaccination, which will be the optimal response to prevent infection, but no vaccine has yet been developed. Although research is being conducted to sequence the mosquito genome and this seems a positive avenue, the amount of money currently available to fund the research is limited. One estimate at the turn of the century is that approximately $84 million is spent annually, which equates to some $42 per fatality. This is only a fraction of the amount of money spent on diseases that cause significant numbers of fatalities in developed countries. The likely cost of an effective vaccine would be outweighed by the public health and human resource savings that the reduction in the death rate would provide. Estimates of the impact of malaria on economic development indicate a correlation between the disease and an economic growth rate 2 percent lower than comparator countries. The computer software multimillionaire Bill Gates has been supportive of this initiative. Malariology has become an important subject within tropical medicine and public health generally. Because the World Health Organization is reporting that the resistance to existing antimalarial drugs is increasing and spreading, the need for awareness of the spread and possible suppression of the disease is becoming more urgent. SEE ALSO: Malaria; Malariologist; Parasitic Diseases. Bibliography. Michael Kremner and Jeffrey Sachs, “A
Cure for Indifference,” Financial Times (May 5, 1999); J. Sachs and P. Malaney, “The Economic and Social Burden of Malaria,” Nature (v.415, 2002); Frank Snowden, The Conquest of Malaria: Italy, 1900–62 (Yale University Press, 2006); David Warrell and Herbert Gilles, eds., Essential Malariology, 4th ed. (Hodder Arnold, 2002); World Health Organization, “Drug Resistance: Malaria,” www.who.int/ drugresistance/malaria/en/ (cited May 2007).
John Walsh Shinawatra University, Thailand
Malawi Malawi is a landlocked country located in southeastern Africa. A long, narrow country within the Great Rift Valley, it is home to Lake Nyasa (also known as Lake Malawi), the third largest lake in Africa. Slightly smaller in size than the state of Pennsylvania, it is dwarfed by neighboring Tanzania, Mozambique, and Zambia. Beyond its physical beauty, Malawi is a country in crisis, with most of its people facing poverty, malnutrition, and above all, the horrifying repercussions of the AIDS epidemic. The population is approximately 13 million, with an annual growth rate of 2.38 percent. This comes from natural increase: the birth rate is 41.13 per 1,000 people, the death rate 19.33 per 1,000 people. Although only 15 percent of the people live in urban areas, Malawi is nevertheless one of the more crowded countries in southern Africa, with 109 people per square kilometer. Few countries have been as ravaged by AIDS as Malawi, and any discussion of the nation’s health has to begin there. Over 16 percent of Malawi’s population is now infected with human immunodeficiency virus (HIV)/AIDS—perhaps 1 million people in all, with upward of 100,000 already dead from the virus. AIDS is the primary cause in 70 percent of all hospital deaths. In the past two years, the number of patients receiving antiretroviral medications has expanded from 4,000 to 46,000, still just a fraction of those who need them. The impact on life expectancy is staggering: At birth, the average Malawian, male or female, can anticipate living only to the age of 42. Healthy life expectancy is just 35 years. Infant mortality is 113 deaths per 1,000 live births; 175 out of every 1,000 die between the ages of 1 and 5 years. At least 500,000 children have lost one or both parents to the virus. Between 1995 and 2005, maternal mortality jumped from 580 deaths per 100,000 live births to 1,800 deaths per 100,000 live births—a fatality rate second only to Sierra Leone. Malawi is an agricultural nation, with 90 percent of the workforce involved in farming an economy based on the export of tobacco, tea, coffee, and sugar. However, working-aged people are those most likely to suffer from AIDS, leaving a limited amount of young people to perform such manual labor. To-
Malaysia
day, Malawi has the lowest Gross Domestic Product in the world. Per capita income is $170 a year, and 42 percent of the population live on less than $1 a day. A weakened workforce and a prolonged period of drought has hurt Malawi’s ability to feed itself. Even before AIDS, the Malawian diet was nutrient poor. Staple crops are millet, maize, and sorghum, with two-thirds of the animal protein coming from fish. In 2005, Malawian president Bingu wa Mutharika declared a food emergency in all 28 districts of the country, and the United States Agency for International Development (USAID) estimated that 5.1 million people would require food rations to get them through until the 2006 harvest. Malnutrition alone reduces the body’s ability to fight off opportunistic infections by about 50 percent, but this is not the only problem facing Malawians. Sanitation is another critical factor in public health. About 67 percent of the people have access to clean drinking water, and only 46 percent have sanitary facilities. This increases the risk of water- and vectorborne illnesses such as diarrhea, typhoid, hepatitis A, and malaria. There are regional outbreaks of plague and sporadic outbreaks of schistosomiasis. The rate of acute respiratory illness is also high. Tuberculosis (TB) has risen along with the AIDS epidemic, with 501 people out of every 100,000 positive for TB. Most Malawians have limited access to healthcare. The Ministry of Health maintains a network of 4 central hospitals, 24 district hospitals, 328 health centers, 68 dispensaries, 16 maternity hospitals, 35 rural hospitals, and 2 mental hospitals. However, the World Health Organization tallied only 266 physicians and 7,264 nurses in Malawi in 2004. The national health system is augmented by any number of nongovernmental organizations (NGOs) hard at work within the country, but Malawi faces such a complex set of environmental and epidemiological problems that real progress is difficult to find.
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Malaysia Malaysia is a large nation on the southeastern edge of Asia. Actually a federation of 13 separate states, the country is split into West Malaysia on the mainland, and Malaysian Borneo (or East Malaysia) about 400 miles across the South China Sea. The majority of the population lives on the mainland. The majority of citizens are Muslim Malays, but it is a highly multiethnic society with large Indian, Thai, and Chinese communities. The Malaysian government has poured considerable money and resources into its health system in an effort to improve the lives of citizens. The population of Malaysia is 24,358,858 and growing at a rate of 1.78 percent annually. There are also an unknown number of illegal immigrants living and working within the country, numbering perhaps
SEE ALSO: Death Rate; Healthcare, Africa; Nutrition. Bibliography. The African Development Bank, Afri-
can Development Report 2006 (Oxford University Press, 2006). Heather K. Michon Independent Scholar
Particularly in urban areas, such as Kuala Lumpur above, Malaysians have options for medical care and access to dental care.
1056 Maldives 1 million or more. The urbanization rate is 69 percent. Unemployment is 3.5 percent, with 85 percent of the workforce in the industrial or service sectors. The poverty rate is 8 percent. Life expectancy has been rising steadily since the 1960s, and now stands at 69.8 years for males and 75.4 years for females. Childhood mortality is low, with 10 deaths per 1,000 for children younger than 1 and 16 deaths per 1,000 for children between the ages of 1 and 5. More than 95 percent of children receive immunizations for tuberculosis, polio, measles, hepatitis B, and diphtheria, pertussis, and tetanus. Maternal mortality is 41 deaths per 100,000 live births, and 97 percent of women have a trained attendant present during childbirth. While the entire country has safe drinking water and sanitary facilities, water-, food-, and vector-borne diseases still affect some Malaysians, particularly those in rural areas. Among the most common infectious diseases are giardia, hepatitis A, typhoid, and dengue fever. Filariasis cis present in some regions. The country’s medical system is well equipped to monitor and respond to outbreaks of these and common communicable diseases, greatly reducing mortality rates. In 1999, Malaysia suffered an outbreak of a new zoonotic virus called Nipah, after the area in which it was first detected. The Nipah virus seems to be carried by fruit bats, and can be transmitted to both people and pigs. The virus causes severe flu-like symptoms and develops into an inflammation of the brain. With no known treatment, Nipah virus has been fatal in about 50 percent of recorded cases. The largest known outbreak, in 1998–1999, infected 265 people and killed 105. Although most Malaysians have a diet rich in vegetables, fruits, seafood, rice, and noodles, there has been a rise in the modern “lifestyle” diseases common to higher-income nations in recent years. The World Health Organization estimated 942,000 Malaysians were living with diabetes in 2000; the number is projected to grow to 2.5 million by 2030. Leading causes of mortality are heart disease, cerebrovascular disorders, and cancer. Deaths and injuries in accidents are also increasingly common, both due to the country’s increased urbanization rates and a large youth population more likely to engage in risk taking. Forty-two percent of Malaysians are under the age of 20.
The prevalence rate of HIV/AIDS in Malaysians aged 15–49 is quite low at 0.5 percent. About 70,000 Malaysians are believed to be infected, with approximately 4,000 deaths attributed to the disease. It is most common in male intravenous drug users, but is seen increasingly in females engaging in unprotected sex. Government health officials have instituted programs to distribute condoms and clean needles to at-risk populations, but have run into some opposition from the country’s Muslim clerics. The country has a large medical sector, with 128 general hospitals, 3,148 district hospitals, and 222 private hospitals counted by the Ministry of Health in 2004–2005. Particularly in urban areas, Malaysians have a variety of options for care, including traditional practitioners, mobile clinics in rural areas, and access to dental care. The World Health Organization notes that the increasing prevalence of managed care and private insurance may be limiting access to care for some moderate- to low-income citizens. SEE ALSO: Healthcare, Asia and Oceania. BIBLIOGRAPHY. Carol Laderman, Wives and Midwives:
Childbirth and Nutrition in Rural Malaysia (University of California Press, 1987).
Heather K. Michon Independent Scholar
Maldives Maldives is an island nation in the Indian Ocean, off the southern tip of the India. It is a chain of 1190 small coral islands groups into atolls, with a total land area of 298 km2 (115 mi2). About 200 of these islands are inhabited; 80 of them are home to tourist resorts. The highest point in Maldives is just 2.4 meters above sea level, making them vulnerable to sea level rise. The capital city of Male is surrounded by a high seawall nicknamed “the Great Wall of Male,” but with global warming expected to cause a further rise in the water level, many of the islands may not be able to survive inundation. In December 2004, the Maldives were hit by the Indian Ocean tsunami that devastated Southeast Asia.
Male Genital Disorders
Although loss of life was minimal, only 9 of the islands escaped flooding and thousands were displaced. The widespread destruction of infrastructure has disrupted tourism, the backbone of island economy, and deepened the poverty of many Maldavians. Total population of the Maldives in 369,000, with annual population growth estimated at 2.73 percent. Population growth is putting pressure on the nation’s limited natural resources, and the government has been attempting to slow the rate of increase for more than a decade. In the early 1990s, the fertility rate was 5.4 children per woman; today it is 2.8 children. Child mortality has also dropped significantly since the 1990s, and is today at 33 deaths per 1000 live births for infants under age 1 and 42 deaths per 1000 for children under 5. Life expectancy is 63.4 for males and 66.2 for females. Poor nutrition is an ongoing problem for the Maldives. With little agricultural land avaliable on the islands, rice and fish are the the dietary staples, with most other food imported from abroad. These imports are usually laden with sugar or sodium, and little by way of fresh fruits, vegetables and other greens make it to the markets. With a poverty rate of around 20 percent, most Maldavians have a hard time meeting their nutritional needs. UNICEF says the Maldives has one of the worst nutritional profiles in South Asia, with 30 percent of children on the islands suffering from malnutrition and 25 percent showing signs of stunting. Among adults, poor diet is being seen in increasing rates of obesity, heart disease, diabetes, and other chronic diseases. Drug abuse has emerged as an issue within the Maldives, particularly among the large adolescent population. Heroin is most popular, along with marijuana and prescription drugs, but there are also dangerous local concoctions like “cola water,” mixing eau de cologne with soft drinks or coconut juice; or Dunlop, a type of glue, which is sometimes mixed with coconut and smoked. Impure heroin is sometimes mixed with sawdust or dried human bones to increase the quality. In 1997, the government instituted the Narcotic Control Board to deal with all aspects of substance abuse, from coordinating education programs to building cooperative strategies with international agencies to stop the flow of drugs into the islands.
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However, drug abuse seems to be on the increase since the the 2004 tsunami, which closed up many treatment and education programs. Widespread drug abuse has fueled an increase in sexually transmitted disease and HIV/AIDS. Although the number of AIDS cases identified on the islands is low—142 diagnoses between 1991 and 2004—the epidemic does have the potential to spread dramatically. See also: Disease and Poverty; Healthcare, Asia and
Oceania.
Bibliography. Robert P. Smith and .Stephen D. Sears,
Blackwell’s Primary Care Essentials: Travel Medicine (Blackwell Publishers, 2002); “Maldives,” CIA World Factbook, www.cia.gov (cited August 2007).
Heather K. Michon Independent Scholar
Male Genital Disorders Male genitals are a connected set of three areas. Inside of the scrotum are the testicles, the blood vessels that supply the testicles and the ducts that lead to the prostrate which is the second area of sexual function. The penis is the external shaft that is used for both urination and for sexual intercourse. All three areas can be disturbed by infections, injuries, dysfunctions, or by cancers. The scrotum is a sack that holds the testicles. Situated between the legs it is subject to skin infections because it is kept warm and moist by clothing. Inadequate washing can promote the growth of fungus infection commonly called jock itch (tinea cruris). It causes the skin to be come red, itchy and irritating. It usually spreads to the buttocks, inner thighs as well as to the genitals. Ringworm is a similar fungal infection. Treatment includes keeps the areas clean and dry with the application of a topical antifungal ointment, which is usually effective in eliminating these problems. Another scrotum dermatological ailment is scrotadynia, but it is more difficult to treat successfully. Yeast infections can also affect the area where the folds of
1058 Male Genital Disorders the scrotum touch the legs, or inside of the foreskin of the penis. The testicles are subject to several ailments due to impact, injury or to diseases. A “low blow” groin attack can fracture the pelvic bone. The ability to walk and death due to shock are also possible consequences. The most common disorders are due to infection and cancer. Infections of the testicles (orchitis or epididymitis) cause swelling and pain in the testicle(s). Mumps are a common cause of orchitis in children. Ischemic orchitis can be the result of damage to blood vessels of the spermatic cords. This may occur during hernia repair; or it may be due to a “twisted testicle” which is a twisting of the blood vessel. If not treated, the testicle can die. The veins of the testicle and scrotum can also become enlarged so that draining of the testicles does not occur properly possibly due to defective valves. The condition can cause sterility. A lack of testicles may be the result of castration for punishment or for cultural effects. Both testicles may be absent at birth (anorchia). In many males born premature one or both the testes may not have descended (cryptochidism). Orchidectomy is the medical removal of the testicles. Testis neoplasm (tumors) can develop in the testes. Broadly grouped the tumors are those of the germ cells (seminomatous or non-seminomatous) or they may develop in the non-germ cells. Most tumors are of the germ cells. Most of the others are of the sexcord stromal tumors, tumors in the paratesticular tissues or a mixture. These are tumors or growth may be benign or cancerous. Testicular cancer develops in the testicles and is fatal if not treated. With treatment almost all males recover. It occurs most frequently in males between the ages of fifteen and forty. Epididymal cysts, Hydatid of Morgagni are painful but non-cancerous lumps in the testicles. Prostate disorders include infections, enlargement and cancer. The enlargement of the prostate is very common in men. The prostate in middle aged or older men may grow large enough to stop urination. The condition can easily lead to death. Infections can be treated with antibiotics. Prostate cancer is also a frequently occurring disorder. In men only skin cancer occurs more commonly. The usual methods of treatment are surgery, radiation therapy and hormone therapy. The penis is subject to a number of in-
fections, conditions and to cancer. Balanoposthitis is an inflammation of the penis (balanitis) and prepuce (posthitis) is an inflammation of the foreskin of the penis. If the penis cannot be extruded from the prepuce the condition is called phimosis. It may caused by inflammation, neoplasia or by an inherited congenital condition. Erectile dysfunctions (impotency) include the inability to achieve an erection, or an incomplete erection. Males with diabetes or other problems commonly experience this condition. There are a number of drugs currently available to aid with this problem. Another erectile dysfunction is the failure of the erection to end (priapism). The cause is likely to be due to spinal cord lesions, genitourinary infection, constipation, or some other cause. Premature ejaculation, also called premature climax (ejaculation praecox) is another male dysfunction as is sterility. Penile cancer can affect any part of the head or shaft of the penis. Most penile cancers occur on the glans penis (head) of the penis. It has several forms which are curable in diagnosed in early stages. It rarely occurs in circumcised men. Many cases are brought on by the virus that causes venereal warts (condyloma acuminate). Precancerous penile lesions such as Erythroplasia of Queyrat (Bowen’s disease) can turn malignant if the lesion turns into squamous cell carcinoma. Treatment depends upon the stage of the cancer’s development. Radiation, chemotherapy, and surgery are common treatments. See Also: Antibiotics; Impotence; Penile Cancer; Pros-
tate Cancer; Prostate Diseases; Testicular Cancer; Urinary Tract Infections. BIBLIOGRAPHY. Rino Cerio. Genital Skin Disorders: A
Guide to Non-Sexually Transmitted Conditions (Edward Arnols, 1999); Benjamin K. Fisher and Lynette J. Margesson. Genital Skin Disorders (Elsevier Health Services, 1998); Fouad R. Kandeel. Male Sexual Dysfunction: Pathophysiology and Treatment (CRC Press, 2007); Hartmut Porst and Jacques Buyat. Standard Practice in Sexual Medicine (Blackwell Publishers Limited, 2006); Yosh Taguchi. Private Parts: A Doctor’s Guide to the Male Anatomy (Doubleday Publishing, 1989). Andrew J. Waskey Dalton State College
Mali Mali, in Western Africa, was once the center of African civilization and home to the legendary city of Timbuktu. Today, it is one of the world’s poorest nations, struggling with persistent droughts, troubled neighbors, and deepening food insecurity. The total population is 11.7 million, growing at 2.63 percent annually. Most Malians are subsistence farmers, surviving on millet, rice, wheat, corn, fish, and livestock production. Like much of western Africa, the country has suffered from drought and poor crop yields in recent years. The United Nations estimates that 2.2 million (20 percent of the population) were at risk for malnutrition in Mali in 2005. The Malian government has instituted a monitoring program to identify areas where food supplementation is most critical. Poverty is endemic, with an estimated 72 percent of the population living on less than $1 a day. Life expectancy is presently estimated at 47 years for males and 51 years for females. Child mortality is 120 deaths per 1,000 for children under age 1, and 218 deaths per 1,000 for children aged 1–5. Maternal mortality is high among Malian women, standing at 630 maternal deaths per 100,000 live births in 2000. The fertility rate is 7.5 birth per woman. Few births occur in hospitals, and only 40 percent are monitored by a trained attendant. Child marriage is common, with 74 percent of rural children and 46 percent of urban children marrying before age 16. Female genital mutilation (FMG) is widely practiced, with more than 90 percent of Malian women aged 15 to 49 having undergone some form of FGM or cutting. Only 6 percent of women have access to modern birth control. Only 38 percent of women are literate. Mali is squarely located in the African Meningitis Belt and suffers frequent, widespread outbreaks. The country has also suffered through several large outbreaks of yellow fever and cholera since 2005. Gastrointestinal diseases are common (because less than 50 percent of the population have access to clean water or sanitation), as are hepatitis A, typhoid fever, and schistosomiasis. Malaria is still the country’s leading cause of death, with insufficient supplies of antimalaria drugs to reach those most vulnerable. The adult prevalence rate for human immunodeficiency virus (HIV)/AIDS is 1.7 percent, low for the
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region. An estimated 140,000 Malians are currently infected, and 12,000 have died from the virus since record keeping began in the 1990s. Forty-seven percent of those infected are women, and 11 percent are children younger than 14. Medical facilities are difficult to find outside the capital city of Bamako. It is estimated that 85 percent of the rural population live more than 30 kilometers from the nearest hospital. Annual government expenditures on healthcare are $9 per capita. The assistance of nongovernmental organizations has been crucial in providing care for the 68 percent of Malians living outside the cities. Medicins Sans Frontières/Doctors Without Borders has been active within the country since at least 1992, with an international staff of 15 and a local staff of 87. SEE ALSO: Healthcare, Africa; Medicins Sans Frontières. Bibliography. Pascal James Imperato, A Wind in Africa:
A Story of Modern Medicine in Mali (W.H. Green, 1975): “Mali,” CIA World Factbook, www.cia.gov (cited August 2007). Heather K. Michon Independent Scholar
Malignant Mesothelioma Malignant mesothelioma is a rare and aggressive cancer that attacks the mesothelium, the membrane that lines body cavities and envelopes major organs. This membrane consists, in part, of the pleural membrane that lines the inside of the chest cavity and covers the outside of the lungs. Exposure to asbestos is virtually the exclusive cause of malignant mesothelioma. This cancer has a long latency period. Typically, symptoms do not appear until 20 to 50 years after initial exposure to asbestos. In the United States, about 2,500 people are diagnosed annually with malignant mesothelioma. The widespread past misuse of asbestos combined with the prolonged latency of this cancer forecasts an increase in the number of mesothelioma cases in the years ahead. Victims of mesothelioma have usually inhaled asbestos particles as a consequence of employment.
1060 Malignant Mesothelioma Because asbestos has many desirable properties, such as resistance to both heat and electrical transfer as well as to chemical degradation, it has been used widely in the construction trades, and many manufacturing and repair industries. Those at highest risk have been insulation installers, pipe fitters, power plant and shipyard workers, installers of linoleum, and automobile brake mechanics. Mesothelioma has also been related to the nonoccupational use of asbestos-containing home repair products. Additionally, mesothelioma can develop from bystander exposure to asbestos, for instance, as the result of handling a directly exposed person’s work cloths. Occasionally, inhaled asbestos fibers get trapped by mucus in the throat and swallowed. These fibers migrate across the intestinal wall into the peritoneal membrane that lines the inside of the abdominal cavity and covers the outside of the abdominal organs. Mesothelioma on this membrane accounts for only one-fifth of all mesothelioma cases. Unless specified otherwise, the term mesothelioma generally refers to pleural mesothelioma. Symptoms of Mesothelioma The symptoms of mesothelioma do not appear until several decades after exposure to asbestos. These symptoms include shortness of breath (dyspnea), chronic cough, fatigue, persistent pain in the chest or upper back, wheezing, painful breathing, weight loss, coughing up blood (hemoptysis), and frequent lung infections. Generally, by the time these symptoms appear, the disease has already developed to an advanced stage. Even then, the vague natures of these symptoms are often mistaken for a lingering cold and medical advice is not immediately sought. Like any cancer, mesothelioma results from atypical cell reproduction. Clumps of these abnormal cells form tumors. As a tumor develops, it causes thickening of the pleural membrane around the lungs and breathing becomes progressively more difficult. The tumor can cause an effusion of fluid to accumulate in the chest. This buildup of fluid or pleural effusion can further restrict the expansion of the lungs. At first, a person with mesothelioma might experience breathing difficulties only during exercise, but as lung function decreases, breathing becomes difficult even at rest. Growth of the tumor can invade nearby tissues of
the chest wall and ribs, and spread to distant tissues through the blood and lymph. Diagnosis Because mesothelioma is rare and its symptoms are not unique, this cancer is difficult to recognize. Typically, mesothelioma cannot be seen on an X-ray and, therefore, it is not unusual for this disease to go undetected during a routine physical examination. A person with respiratory symptoms and a history of exposure to asbestos should be evaluated with more advanced imaging techniques such as computed axial tomography (CAT) or magnetic resonance imaging (MRI). These techniques consist of a series of thin, cross-sectional X-rays that better detect thickening of the pleural membrane. Still more sophisticated in its ability to identify mesothelioma is the positron emission tomography (PET) imaging technique. If any of these imaging techniques indicate the suspicion of mesothelioma, a biopsy will be performed. This may be accomplished by the aspiration of a small amount of pleural tissue through a fine needle (needle biopsy) inserted through the chest wall, or by the removal of a small tissue sample with the help of a thin, lighted tube (thoracscope) inserted through a small incision in the chest and guided by a camera. The removed tissue is examined under a microscope to ascertain a firm diagnosis of mesothelioma. Promising work is being done on diagnostic markers. Markers are substances that occur at higher levels in patients with a disease than in people without that disease. One such mesothelioma marker, called soluble mesothelin–related protein (SMRP), assayed by a blood test, is now used in Europe and Australia to aid in early diagnosis of mesothelioma. Treatment Treatment options for malignant mesothelioma include surgical intervention in which a portion of the pleural membrane (pleurectomy) or a lung (pneumonectomy), is removed, radiation therapy in which radiation is used to kill cancer cells and shrink tumors, and chemotherapy in which drugs that enter the bloodstream and travel throughout the body are used to kill cancer cells. A treatment plan that utilized more than one of these options is known as multimodality therapy. An important influence on treatment choice is the determination of
Malta
the cancer’s developmental stage. Mesothelioma is at an early, localized stage if the cancer is confined to the pleura membrane. The disease is advanced if it has spread beyond the pleura membrane to other parts of the body such as the lungs, chest wall, or lymph nodes. Only patients with localized, earlystage mesothelioma have shown improved survival with surgical intervention. Because in the majority of cases mesothelioma has progressed to an advanced stage before it is detected, generally treatment is palliative (focused on pain management and quality of life) rather than curative. Although radiation therapy and/or chemotherapy might be used with advanced-stage patients, these treatments offer these patients only short-term symptoms control through temporarily slowed tumor growth. The drainage of any pleural effusion, a procedure called thoracentesis, is another measure that reduces the discomfort of this disease. Most victims of mesothelioma survive less than 12 months after the disease is diagnosed. SEE ALSO: Asbestos/Asbestosis; Environmental Health. Bibliography. Richard K. Albert, Stephen G. Spiro,
and James R. Jett, Clinical Respiratory Medicine (Mosby, 2004); Marin D. Abeloff, et al., Clinical Oncology (Elsevier Churchill Livingstone, 2004); The Mesothelioma Center, “Asbestos Cancer: Mesothelioma,” www.mesotheliomacenter.org/ (cited October 2006).
Paul J. Clerkin Sacramento City College
Malta The Republic of Malta in the Mediterranean, is located between Italy and Tunisia, and has historical ties to both places, having been occupied by the Carthaginians and then the Romans. Ruled by the Byzantines from 395 until 870, it was then occupied by the Arabs and held by the Normans from 1090 until 1530 when it was ceded to the Knights of St. John of Jerusalem —the Knights Hospitaller. Occupied briefly by the French from 1798 until 1800, it was taken by the Brit-
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ish and was formally a British colony from 1814 until independence in 1974. Traditionally many of the healthcare problems on Malta had to do with poor sanitation, with cases of cholera, and also the presence of mosquitoes which can lead to infections. Nowadays, heat exhaustion and heatstroke, conditions that continue to affect hundreds of tourists each year, cause many people to seek medical treatment. From Norman times, there were numbers of Jewish doctors employed in Malta, especially at the Hospital of the Holy Ghost, the first hospital on the island, built at Rabat in about 1300. St. Peter’s Hospital operated in Mdina, then the capital of the island until 1418 when Margaret of Aragon established another hospital on the island, with St. Julian’s Hospital founded on the nearby island of Gozo, in 1454. After the arrival of the Knights of St. John, healthcare on the island dramatically improved, and following the Knights defeating the Turks in 1565, the Holy Infirmary was built in Valletta which emerged as the new capital. Subsequently women’s hospitals were built, and also the Civil Hospital for Men at Valetta. There have long been records of people suffering from “fevers” on Malta, and in 1530 malaria first appeared, with a terrible malaria epidemic hitting Rabat and Mdina in 1707–1709. There had also been a number of plague epidemics, in 1592–1593, in 1623, in 1655, in 1675–1677, in 1813–1814, and the most recent one in 1917. There were also minor epidemics in 1936–1937 and 1945–1946. Cholera epidemics have also hit the island in 1767, 1770, 1783, 1837, 1850, 1854, 1856, 1865, 1867, 1887 and 1911. Tuberculosis remained a major problem until the twentieth century, with venereal diseases also being relatively common. Leprosy was a minor problem on Malta and Gozo, as was trachoma and poliomyelitis. Today, Malta maintains one of the better healthcare systems in the region, with St. Luke’s Hospital near Pietà, south-west of Valletta, dealing with most major casualties on the island of Malta, and Craig Hospital in Gozo covering that island. There is also a wide network of general practitioners, with Malta having 261 doctors and 1100 nurses per 100,000 people. There is a national health service which guarantees free treatment to all citizens. Traditionally doctors from Malta have been trained in France, Britain or Italy, but increasing numbers are
1062 Managed Care studying in Malta where a new teaching hospital has been built at the University of Malta at Msida. SEE ALSO: Healthcare, Europe; Italy; Tunisia. Bibliography. Paul Cassar, Medical History of Malta
(Wellcome Historical Medical Library, 1964). “Malta,” CIA World Factbook, www.cia.goc (cited August 2007). Justin Corfield Geelong Grammar School, Australia
Managed Care Managed care is a way to deliver healthcare services based on the goals of controlling costs and utilization of healthcare services, while simultaneously attempting to measure quality of the care provided. The idea of managed care was developed as an attempt to reduce rising costs experienced with previous indemnity insurance plans. The first health insurance companies supplied monetary reimbursement to hospitals and physicians for patient care on a fee-for-service basis, which meant payment for whatever services or procedures were provided to the patient. By the middle of the 20th century, problems evolved with this framework. Patients were consuming more care because they did not have to pay much, if anything for it, and some physicians were providing services beyond what was medically necessary for a variety of reasons—including to decrease their chances of being sued by ordering many tests, and also to receive more income. These two problems created increased costs and less efficient patient care. Therefore, managed care developed in an attempt to solve these problems. The initial Managed Care Organizations (MCOs) of the early 20th century were Health Maintenance Organizations (HMOs), which involved physicians contracting with employers to deliver medical care for employees. The physicians were prepaid a flat fee for each employee per month, and provided care whenever it was needed. This idea developed throughout the century, and some HMOs even built their own hospitals to care for patients.
MCOs today are structured so that patients have a limited number of healthcare providers whose services will be reimbursed by the MCO. The MCO and the providers negotiate to determine how much money will be paid for each procedure or service. Managed care plans are organized into four different structural formats, depending on the relationship of the physicians to the insurance company. In one group, the physicians work directly for the insurance company. In another format, the insurance company contracts with a large physician group to provide medical services. These first two formats usually involve a much stricter contract than the last two, and limit the hospitals to which each physician may admit patients. The third and fourth organizational structures are less concrete and largely exist as networks between insurers and physicians. The third structure involves a large group of physicians that acts as its own insurer, collecting payment from patients and in turn compensating the member physicians. The fourth and final organizational format for MCOs involves large insurers contracting with individual physicians or small physician groups. This format differs from the first two in that the physicians are allowed to contract with more than one insurer, and they have more freedom in how they run their private practice. Healthcare is continuously evolving, and the way care is provided to patients will forever be changing. Managed care has been a reality in the late 20th and early 21st centuries, but its future is unknown because of the political and economic issues that are always emerging. SEE ALSO: Conventional Medicine; Insurance; Health Main-
tenance Organizations.
Bibliography. David Dranove, The Economic Evolution
of American Health Care (Springer Publishing Company, Inc., 2000); Helen L. Smits, “Managed Care,” Health Care Deliver in the United States, Anthony Kovner and Steven Jonas, eds. (Springer Publishing Company, Inc., 2002); Kenneth E. Thorpe and James R. Knickman, “Financing for Health Care,” Health Care Deliver in the United States, Anthony Kovner and Steven Jonas, eds. (Springer, 2002) George Kolo, D.O. Sarah Sundet Independent Scholars
Manic-depressive illness is a chronic illness that must be managed in the long term with careful treatment.
Manic-Depressive Illness Manic-depressive illness, also known as bipolar disorder, is a mental illness primarily characterized by shifts in a person’s mood and accompanied by impaired social and somatic functioning. These impairments differ from the daily variations in mood experienced as “normal”; manic-depressive illness differs also from depression, although many patients with manic-depressive illness first present with depression. Individuals with manic-depressive illness have severe symptoms, which if left untreated, can result in significant damage to social and professional standing as well as an increased risk for suicide. Diagnostic Criteria The Diagnostic and Statistical Manual of Mental Disorders, 4th ed. (DSM-IV), published by the American Psychiatric Association (APA), establishes the diagnostic criteria used by clinicians in diagnosing bipolar disorder and defines both episodes of this illness: mania and depression. Mania is a clearly defined period of unusually elevated or irritable mood that is of at least one week in duration and is usually accompanied by at least three of the following symptoms: exaggerated self-esteem, decreased need for sleep, more talkative than normal, racing thoughts, high distractibility (cannot concentrate well), abuse of pleasurable activities such as spending money or sexual activity, drug abuse
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(particularly cocaine and alcohol), aggressive or intrusive behavior, or a denial that anything is out of the ordinary. In addition, these disturbances in mood cause significant diminishing in social or professional functioning and are not related directly to substance abuse or a medical illness. The criteria for an episode of major depression include any of the five following signs and symptoms: lasting sad mood or feeling of emptiness, significant loss of interest in activities once pleasurable, significant weight loss or gain, sleeping too much or too little, decreased energy, fatigue or feeling “slowed down,” feelings of guilt or worthlessness, inability to concentrate or make decisions easily, and persistent thoughts of death or of suicide. These symptoms should be present nearly every day for two weeks or longer and cause significant diminishing in social or professional functioning also not related directly to substance abuse or a medical condition and do not occur in the two months following the death of a loved one. Bipolar disorder is classified into two distinct subtypes. Bipolar I disorder is the “classic” form of the illness; patients have a history of at least one manic episode and may or may not have experienced previous depressive episodes. Patients with bipolar II disorder may not have symptoms of severe mania and instead suffer a mild to moderate mania called hypomania along with episodes of major depression. Four or more mood episodes in the last 12 months constitute the definition of rapid cycling bipolar disorder. Between 10 and 15 percent of individuals with bipolar disorder experience rapid cycling, and in general, rapid cycling is found to be more common in women than in men. Other disorders with similar features may coexist with manic-depressive illness: schizophrenia, posttraumatic stress disorder, substance abuse, and personality disorders. Also, preexisting conditions such as multiple sclerosis and medications, steroids, or substance abuse may contribute to or complicate the treatment process. A complete medical evaluation and psychiatric history are essential in establishing a diagnosis of manic-depressive illness. Epidemiology and Cause Approximately 5.7 million adults living in the United States suffer from manic-depressive illness. The lifetime prevalence of bipolar disorder is estimated at
1064 Manic-Depressive Illness 1 percent, although including the broader spectrum of bipolar disorders may incur a higher estimate. Bipolar disorder comprises approximately 25 percent of all mood disorders. Onset of bipolar disorder generally occurs between ages 15–30, although individuals with an early onset of the disorder may have more psychotic symptoms. Men and women are equally affected, although females tend to have more severe, rapid-cycling form of the illness. A genetic link has been established, resulting in an increased risk for first-degree relatives of those with the illness. Although no gene that “causes” bipolar disorder has been identified, research concludes that the cause of bipolar disorder is attributed to a combination of many genetic and environmental factors. There is no clear evidence to suggest a relationship between life events and the triggering of manic and depressive episodes, although being female, having a family history of bipolar disorder, as well as coming from an upper socioeconomic class have been identified as risk factors for the disorder. Outcomes and Treatment The course of bipolar disorder is heavily marked by alternating manic and depressive episodes. Many patients with manic-depressive illness can be symptom-free between episodes, but an estimated onethird still exhibit symptoms. Nearly all individuals who experience one manic episode will experience another within a period of five years. Hospitalization on a psychiatric ward is another common experience. Addictive disorders have a profound influence on the course of bipolar disorder, affecting nearly two-thirds of individuals with manic-depressive illness. Manic-depressive illness is a chronic illness that must be managed in the long term. With careful treatment, many individuals with bipolar disorder achieve significant stabilization of their manic and depressive symptoms and sustain a good quality of life, although a small number of patients experience unremitting symptoms in spite of treatment. However, without effective treatment, the course of bipolar disorder may worsen, and the individual may experience more frequent and more severe manic and depressive episodes. Successful treatment of bipolar disorder is continuous as interruptions in treatment may trigger change in mood. Treatment is usually divided into
three phases: acute phase, continuation phase, and maintenance phase. The acute phase is primarily focused on stabilizing the patient and ascertaining his or her safety, particularly if the patient is in imminent danger or is at risk of harming others. The goal of the continuation phase is to achieve a total remission of manic and depressive symptoms; this may last several weeks to months. Once remission is achieved, the maintenance phase is used to sustain remission for at least one year. In the maintenance phase, the goals of treatment are to prevent relapse and recurrence of manic or depressive episodes, to reduce the risk of suicide, and to improve overall functioning. Different psychopharmacological strategies are used to treat manic and depressive episodes. Medications called mood stabilizers are prescribed to control the manic symptoms of bipolar disorder. Although all the mood stabilizers appear to be equally effective, lithium and valproate (an anticonvulsant) remain among the most commonly used medications. Lithium is the first mood stabilizer to be approved by the United States Food and Drug Administration and research on its efficacy finds that approximately 70 percent of patients on lithium report a decrease in manic symptoms. Some common side effects with lithium treatment include tremors, diarrhea, some cognitive side effects, weight gain, and, in the longer term, thyroid disturbance. Although many patients experience some side effects, they are either minor or can be effectively managed with close patient monitoring throughout the course of treatment. Anticonvulsant medications such as valproate are also effective mood stabilizers and are often used for harder-to-treat episodes and in patients with mixed mania and depression. As valproate is associated with hormone abnormalities and ovarian problems in young women, this group is especially monitored closely while on valproate. Common side effects of valproate include nausea, vomiting, hair loss, weight gain, tremor, osteoporosis, and easy bruising. Anticonvulsant medications also may be combined with lithium for a heightened effect. The APA recommends lithium or valproate plus an antipsychotic medication for the treatment of acute manic or mixed-symptom episodes. For acute depression in patients with bipolar disorder, the APA does not recommend treating with antidepressants alone because this could trigger a manic episode instead. Research is
Mansfield, Peter
being conducted on the efficacy on newer anticonvulsant medications—lamotrigine, gabapentin, and topiramate. Electroconvulsive therapy is also considered an effective alternative strategy for treatment of acute or treatment-resistant mania and depression. Psychotherapeutic interventions are also helpful in the treatment of bipolar disorder, particularly in the continuation and maintenance phases. Psychosocial treatments have been shown to increase mood stability, decrease the number of hospitalizations and relapses, and improve functioning and adherence to medications. Integrated psychosocial interventions commonly employed for individuals with bipolar disorder include cognitive behavioral therapy, psychoeducation, family therapy, and substance abuse treatment. Manic-Depressive Illness and Pregnancy Women with bipolar disorder must be advised about possible risks they could incur during pregnancy. Use of lithium during pregnancy is associated with a heightened risk of malformations to the fetus or to other harmful effects to the nursing infant, as lithium is also secreted in the breast milk. Women desiring to conceive are recommended to discuss alternative treatment options (e.g., electroconvulsive therapy) with their clinician. Additionally, women with manicdepressive illness are at a higher risk for postpartum depression and even postpartum psychosis. Manic-Depressive Illness and Suicide Individuals with bipolar disorder experience a shortened life expectancy and have a mortality rate two to three times higher than individuals in the general population. Up to one-half of people with this illness attempt suicide, and 15 percent of individuals with bipolar disorder complete suicide, a rate much higher than among those people with other psychiatric diagnoses. The risk of committing suicide is found to be greater in the earlier stages of the illness. As the majority of suicide attempts are linked to depressive episodes, threats of suicide should always be taken seriously, and immediate help from a mental health professional should be sought for the individual. Symptoms of suicidal ideology may include talking about feeling suicidal, feeling hopeless as if nothing will ever change or that nothing one does will make a difference, abusing drugs and/or alcohol, feeling like
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a burden to loved ones, putting one’s affairs in order as if in preparation for one’s death, writing a suicide note, intentionally putting oneself in dangerous situations. Individuals with bipolar disorder should be closely monitored and assessed for family history of suicide and current risk. SEE ALSO: Depression; Postpartum Depression; Psychia-
try; Suicide.
Bibliography. D. M. Hilty, K. T. Brady, and R. E. Hales,
“A Review of Bipolar Disorder among Adults,” Psychiatric Services (v.50, 1999); R. C. Kessler, et al., “Prevalence, Severity, and Comorbidity of Twelve-Month DSM-IV Disorders in the National Comorbidity Survey Replication (NCS-R),” Archives of General Psychiatry (v.62, 2005); National Institute of Mental Health, “Bipolar Disorder,” http://www.nimh.nih.gov/publicat/bipolar.cfm (cited May 2007); J. Stovall, “Bipolar Disorder,” UpToDate, B. D. Rose, ed., (UpToDate, 2007). Lareina Nadine La Flair, M.P.H. Harvard University
Mansfield, Peter (1933– ) A British physicist who won the Nobel Prize in Physiology or Medicine in 2003 together with Paul Lauterbur, Peter Mansfield contributed to the development of magnetic resonance imaging (MRI), a computerized scanning technology that generates images of internal body structures, particularly those with soft tissues. The MRI is of particular use in the examination of the brain and the spinal cord and in preoperation examinations as it gives surgeons precise information of where a particular lesion is located. It has also proved a fundamental tool in the diagnosis, treatment, and follow-up of cancer. Since its development, the MRI has replaced more invasive techniques of examination and has considerably reduced suffering for patients. Mansfield was born into a working-class family in Lambeth, London, on October 9, 1933. After the war, Mansfield attended Peckham Central School for a year. At 15, Mansfield left school and went to work first as a printer assistant and then at the Ministry of Supply at
1066 Marasmus the Rocket Propulsion Department in Westcott, Buckinghamshire. After two years of National Service in the army, Mansfield returned to his job in Westcott, but also started to study for A-levels. In 1956, he was able to gain university entrance, enrolling at Queen Mary College, University of London, for a degree in physics. Since his undergraduate studies, Mansfield developed an interest in nuclear magnetic resonance (NMR), first discovered in the 1950s by Felix Bloch and Edward Purcell. NMR technology is at the base of MRI. Mansfield went on to postgraduate studies, always researching NMR technology, and graduated in 1962. As part of his postdoctoral program, Mansfield carried out research in the United States at the University of Illinois at Urbana. Upon his return to England, Mansfield was offered a Lectureship at the University of Nottingham. It was while at Nottingham that Mansfield developed his research that would contribute to the application of NMR technology to the human body and thus to the development of MRI. Mansfield succeeded in showing how the MRI radio signals can be mathematically analyzed and he created the MRI protocol called echo-planar imaging. For his contribution to the creation of MRI, Mansfield received many awards in addition to the Nobel Prize such as the 1983 Gold Medal of the Society of Magnetic Resonance in Medicine. He was also elected Fellow to the Royal Society, London, and was knighted in 1993. SEE ALSO: Diagnostic Imaging; Lauterbur, Paul C.; Radi-
ology.
Bibliography. Peter Mansfield, “Autobiography,” The
Nobel Prizes 2003, ed. Tore Frängsmyr (Nobel Foundation, 2004), http://nobelprize.org/nobel_prizes/medicine/ laureates/2003/mansfield-autobio.html (cited July 2007). Luca Prono Independent Scholar
Marasmus Malnutrition is an imbalance between the body’s supply and demand of nutrients that affects function or growth. Protein-energy malnutrition (PEM)
is a potentially fatal condition prevalent in developing countries. PEM disproportionately affects children and pregnant women and accounts, directly and indirectly, for approximately half of under 5-year-old mortality worldwide. The two forms of PEM are marasmus and kwashiorkor. Marasmus is a condition caused by chronic lack of calorie sources in the diet, whereas kwashiorkor is caused by a lack of dietary protein. Calories are the measurement units for how much energy is in food; the main sources of calories in the diet are carbohydrates, fat, and protein. A state of chronic caloric deficit is called marasmus and causes include the following: (1) decreased intake of calories, for example, due to socioeconomic status not able to afford adequate food, weaning child from breast milk with inadequate calories in new diet, famine or war leading to lack of available food to buy, lack of appetite, eating disorders, being on a restrictive diet; (2) increased caloric expenditure, for example, when a woman is pregnant, when children are growing, chronic illness such as AIDS or cancer, acute infection, major surgery; and (3) decreased absorption of food, for example, disease or infection of the intestines, dysfunction in the release of the digestive enzymes from the pancreas. Marasmus is sometimes considered to be a physiologically adaptive response to starvation. Faced with insufficient caloric intake to perform functions required for life, such as breathing, the body begins to break down first its fat and then muscle to generate energy. This results in a shrunken appearance with prominent bones and decreased muscle mass. Because of these accompanying physical changes, the diagnosis of marasmus can be confirmed using height, weight, and anthropometric measures (if kwashiorkor or another diagnosis is not suspected). The body also attempts to lower its own energy requirements by decreasing the base metabolic rate and the growth rate, resulting in stunted growth in affected children and low birth weight children for pregnant women. Marasmic women are at high risk for having low birth weight children, who themselves are more likely to have low birth weight children; this demonstrates the vicious cycle that can be seen with marasmus. Interestingly, because of the biochemical starvation state the body is in, attempting to give a marasmic
Marfan Syndrome
person a lot of high carbohydrate foods quickly can kill them, and so acute treatment involves frequent small meals. SEE ALSO: AIDS; AIDS; Cancer (General); Child Develop-
ment; Kwarshiorkor; Nutrition.
Bibliography. Monika Blössner and Mercedes de Onis,
Malnutrition: Quantifying the Health Impact at National and Local Levels (World Health Organization, 2005).
Mark F. Brady, M.D. Brown University
Marfan Syndrome In the 19th century, French pediatrician Antoine Marfan first described the unique physical findings in a 5-year old girl that latter became known as Marfan syndrome. This syndrome is a multi-system genetic disorder that results from a mutation in the gene that codes for fibrillin, a structural protein that is an integral part of the scaffolding that maintains connective tissue integrity throughout the human body. A fibrillin deficiency weakens the body’s structural components resulting in a variety of clinical complications. Marfan syndrome is a multi-system disease that can result in musculoskeletal, cardiovascular, ocular and neurological complications. With no predilection to sex, Marfan syndrome is relatively uncommon, having an estimated incidence of 2-3/10,000. Though life expectancy, when untreated, is 30-40 years, modern treatment has allowed patients to live nearly as long as the general population. Marfan syndrome is inherited in an autosomal dominant fashion with a high level of penetrance, meaning that anyone possessing the fibrillin mutation will develop symptoms. A small proportion of cases occur in children of unaffected parents as a result of new mutations in the DNA of a parent’s egg or sperm. Marfan syndrome affects long bones, ligaments, tendons, skin and connective tissue. As a result, these people tend to be tall and thin, with disproportionately long arms, legs and spider-like fingers. Stretch marks (striae atrophicae) are the most common dermatological finding. Inguinal hernias, due weakness in abdom-
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inal wall, are typically seen in the groin area. Often, the roof of the mouth is high, resulting in crowding of the teeth and a retreating lower jaw contributes to an overbite. Chest abnormalities such as a sunken-in (pectus excavatum) or protruding sternum (pectus carinatum) can occur concurrently or separately. Pectus excavatum poses a particular problem as it may result in compression of the heart and lungs. Spinal malalignment in the form of either lateral curvature of the spine (scoliosis) or a hunched back (kyphosis) can collectively result in lung compression and joint problems. Hypermobility and joint dislocations are common as tendons and ligaments tend to be weak. Unusually, deep hip sockets (protrusio acetabuli) can cause degenerative arthritis later in life. Cardiovascular complications account for over 90 percent of known causes of death in Marfan syndrome. Weakening in the elastic layer of large arteries can result in the separation of the wall of the aorta (aortic dissection) in addition to a gross dilation of the aorta (aortic aneurysm). These situations are particularly dangerous because the aorta can rupture, causing massive internal bleeding and sudden death. Dilation of the outflow tract of the heart can lead to aortic insufficiency, the incomplete closure of the aortic valve, allowing back-flow of blood into the heart from the aorta. Mitral valve prolapse, a condition present in 75 percent of people with Marfan syndrome, is due to a floppy, leaky valve. Significant aortic and mitral valve dysfunction will require the heart to work harder than it normally should, eventually causing the heart to effectively “burn out”, a condition called congestive heart failure. Atrial and ventricular rhythm disturbances, caused by an abnormal heart conduction system, are another set of factors that predispose Marfan patients to premature death. Cardiovascular complications are often treated with medication to reduce blood pressure, and thus stress on the arteries. Additionally, corrective surgery for aortic dilation and valvular defects may be indicated. People with Marfan syndrome often experience a multitude of visual disturbances. Lens subluxation, shifting of the lens away from its usual central location, occurs because the fibrillin-dependent fibers that normally stabilize the lens of the eye are stretched or absent in Marfan syndrome. Lens subluxation occurs in over 65 percent of patients, usually before the end of the second decade of life. Retinal detachment, the
1068 Marijuana Abuse most serious ocular complication, occurs in 8 to 25 percent of Marfan patients, usually during their early twenties. The incidence of premature cataract formation and glaucoma are disproportionately elevated in the Marfan population. Strabismus the failure of proper eye alignment, is relatively common, and if uncorrected during childhood, can lead to ambylopia (“lazy eye”). Myopia (“near sightedness”) is also common and can be corrected with the use of contact lenses. Shortness of breath and sleep apnea as a result of lung dysfunction frequently occur in Marfan patients. Both scoliosis and chest involution can restrict the ability of the lung to expand, decreasing the patient’s ability to fill their lungs with air. Furthermore reduction in lung elasticity, due to the fibrillin deficiency, can lead to emphysema, asthma, and recurring pneumothoracies (lung collapse). In order to prevent pneumothorax from occurring, patients are advised to avoid activities that involve rapid changes in ambient pressure, such as scuba diving and flying in unpressurized aircraft. Marfan syndrome may also affect the neurological system. The membrane of connective tissue surrounding the spinal cord and the brain is called the dura. In Marfan syndrome, the dura may become enlarged (dura ectasia), especially in the lower spinal column and has an estimated prevalence of 76 percent in the Marfan population. Though symptoms are infrequent, headaches, lower back pain, leg pain and abdominal pain may occur. Additionally, people with Marfan syndrome may be prone to developing aneurysms in the arteries that supply the brain. Because aneurysms weaken the arterial wall, rupture with subsequent intracranial bleeding and death can occur. SEE ALSO: Connective Tissue Disorders; Eye Diseases
(General); Genetics; Growth Disorders; Heart Diseases (General); Scoliosis; Spinal Cord Diseases
Bibliography. P.F. Giampietro, C. Raggio, and J.G. Da-
vis, “Marfan Syndrome: Orthopedic and Genetic Review,” Current Opinion in Pediatrics (v. 14, 2002); D.P. Judge and H.C. Dietz HC, “Marfan’s syndrome,” Lancet (v.366, 2005); L. Nallamshetty, et al., “Plain Radiography of the Lumbosacral Spine in Marfan Syndrome,” Spine J (v.2, 2002); The National Marfan Foundation, www.marfan.org (cited October 2006); R.E. Pyeritz, “The Marfan Syndrome,” Annual Review of Medicine (v.51, 2000); J.F. Remulla and F.I. To-
lentino, “Retinal Detachment in Marfan’s Syndrome,” International Ophthalmology Clinics (v.41, 2001); T.L. Young, “Ophthalmic Genetics/Inherited Eye Disease,” Current Opinion in Ophthalmology (v.14, 2003). Thomas Christian Keller University of Virginia Dino Samartzis Harvard University Francis H. Shen, M.D. University of Virginia
Marijuana Abuse Marijuana is the herbal form of cannabis, a product of the plant cannabis sativa; hashish is the resinous form of the same plant. The primary active compound in cannabis is THC (tetrahydrocannabinol), which has psychoactive and physical effects when smoked or ingested. According to the World Health Organization, cannabis is the most widely cultivated, trafficked and abused illicit drug in the world: cannabis seizures have occurred in almost every country in the world and constitute about half of all drug seizures worldwide, and about 147 million people, or 2.5 percent of the world’s population, are estimated to use cannabis annually. Acute effects of marijuana use include impairment of cognitive processes and psychomotor performance. Cognitive effects include decreased ability to learn and recall new material, while psychomotor effects include impaired motor coordination and divided attention. Operation of complex machinery such as automobiles can be impaired for 24 hours following consumption of 20 mg of THC. Chronic effects of cannabis use include impairment of cognitive functioning which may not recover with cessation of use, injury to the airway, trachea and bronchi, reduced ability to fight off pulmonary infections, and chronic bronchitis; cannabis use during pregnancy is a risk factor for low birth weight and impaired fetal development. Research into the use and abuse of marijuana is complicated by several facts. One is that in countries such as the United States where marijuana use is illegal, it is not possible to know the extent of usage
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or negative medical or social effects for the user. For instance, the Diagnostic and Statistical Manual of Mental Disorders, 4th edition (DSM-IV) published by the American Psychological Association defines marijuana dependence as compulsive use, increased tolerance, impaired control, and continuation of use despite negative physical or psychological consequences. Marijuana abuse is defined by DSM-IV requires repeated instances of use under hazardous conditions, legal problems related to marijuana use, or clinically meaning impairment in social, occupational or educational functioning. Compton and colleagues found no significant change in the increase of marijuana use in the United States in 1991–92 and 2001–02, either overall or among males, females, whites, Blacks or Hispanics; however significant increases were seen among 18to-29-year-old Black and Hispanic women. Using the DSM-IV definitions, they found that marijuana abuse was more prevalent than marijuana dependence: the rate of abuse was 0.9 percent in 1991–92 and 1.1 percent in 2001–02, while the rate of dependence for those years were 0.3 percent and 0.4 percent, respectively. The proportions of abuse versus dependence were relatively consistent across age, sex, and racial/ ethnic subgroups. Acute effects of marijuana use include impairment of cognitive processes and psychomotor performance.
by people who do not come into contact with health or legal authorities concerning their marijuana use, and people may be reluctant to report illegal behavior on surveys. On the other hand, in countries where marijuana use is not illegal, determining how many people use marijuana or how frequently it is used is not necessarily a high priority. In addition, tracking marijuana usage is not a high priority in many developing countries who have greater health concerns to deal with. A third problem is that definitions of “abuse” vary widely: some people believe that any use of marijuana constitutes abuse, and many large-scale surveys report only use/nonuse. However, some organizations have developed criteria for different levels of use or abuse, based on factors such as frequency of use and/
study results According to the National Survey on Drug Use and Health (NSDUH), over 25 million people (10.6 percent) in the U.S. age 12 or older reporting using marijuana in 2003, and 12.2 percent of them used marijuana on 300 or more days in the past year, which the NSDUH defines as daily use. Young adults (age 18-25) were most likely to report daily marijuana use (4.3 percent); daily users were three times as likely to be male, and more likely to be unemployed than non-users or less frequent users. Daily users were also more likely to report more frequent use of illegal drugs and alcohol abuse. Surprisingly, legal restrictions regarding the use of marijuana do not always result in lower usage. For instance, a 2001 study by the World Health Organization comparing the use of alcohol, cigarettes, and illicit drugs among 10thgrade students in the United States and 30 European countries, found that 41 percent of American 10thgraders reported having used marijuana, versus 17 percent of European 10th-graders.
1070 Marshall Islands Even in the Netherlands, which permits marijuana consumption with certain restrictions, only 28 percent of 10th graders reported having used it. See also: Drug Abuse; Drug Enforcement Administra-
tion (DEA); National Institute on Drug Abuse (NIDA); Netherlands.
BIBLIOGRAPHY. American Psychological Association,
Diagnostic and Statistical Manual of Mental Disorders, 4th ed. (American Psychological Association, 1994); Wilson M. Compton, et al., “Prevalence of Marijuana Use Disorders in the United States, 1991–92 and 2001–02,” Journal of the American Medical Association (v.291/17, 2004); Office of Applied Studies, Substance Abuse and Mental Health Services Administration, “Daily Marijuana Users,” The NSDUH Report www.oas.samhsa.gov/ (cited June 2007);World Health Organization, “Cannabis,” www. who.int/substance_abuse/facts/cannabis/en/ (cited June 2007); Kate Zernike, “Study Finds Teenage Drug Use Higher in U.S. than in Europe,” The New York Times (February 21, 2001). Sarah E. Boslaugh BJC HealthCare
Marshall Islands The Marshall Islands are located in the Pacific Ocean, north of Nauru and Kiribati. The republic is comprised of 29 atolls forming two parallel groups known as the Ratak and Ralik (or “Sunrise” and “Sunset”) Chains. Ten of the 29 atolls are uninhabited, and the total landmass of all the islands are 181.3 km2, or about the size of Washington DC. The Marshalls were colonized by Germany in the 1880s, and fell to Japan after World War I. In 1947, they became a United States Trusteeship, although they remained largely self-governing. The trusteeship finally ended in 1990, and the Republic of the Marshall Islands was admitted to the United Nations in 1991. It maintains close economic and diplomatic ties with the U.S.. The population is 61,800 and growing at 2.21 percent annually. The birth rate is 32.37 per 1,000, compared with a death rate of just 4.66 per 1,000. This more than compensates for the negative migration
rate of minus 5.65 per 1,000. Median age is 20.7 years. Life expectancy is 68.61 years for males and 72.71 years for females. Gross national income is $2,930 per capita. Island economy is dependent on U.S. aid and remittances from Marshallese living abroad, with most islanders relying on subsistence farming and fishing and a small tourism industry. Common, generally non-fatal communicable diseases are the main causes of hospital admissions in the Marshall Islands. The Ministry of Health lists influenza, gastroenteritis, scabies, diarrhea, fish poisoning, chicken pox, conjunctivitis, syphilis and amoebas as the leading causes of morbidity. Hepatitis A and B, along with typhoid, are also common. There were 62 cases of leprosy diagnosed in 2004. There were also 119 new cases of tuberculosis. Like many of the Pacific Islands, AIDS has not emerged as a problem. As Marshallese live a more “modern” life, they are quickly absorbing the negative health aspects of that modernity: obesity, increases rates of tobacco, drugs, and alcohol use, more traffic accident, increased suicide rates, and a higher rate of teen pregnancy rates have all been noted by medical authorities. The leading cause of mortality is sepsis, followed by cancers, heart disease, pneumonia, suicide, renal failure, drownding, and trauma. Between 1946 and 1962, the United States conducted a number of weapons tests on the isolated atolls outside the Marshall Islands, the most notable of which was the March 1954 detonation of a hydrogen bomb on Bikini Atoll. The fallout was supposed to blow harmlessly out to sea, but a shift in the winds dropped in directly onto the Tongelap and Utrik atolls of the Marshalls. Over the years, residents have complained of increased rates of stillbirths, malformed or “jelly babies,” strange cancers, goiters, and stunted growth among children, even decades after the fact. A Nuclear Claims Tribunal wrapped up hearings in 2004, but resulted in few provisions for longterm testing or monitoring of the health of these communities. The Ministry of Health had a $16 million budget in 2004. There is one general hospital, one primary-care hospital, and five health centers on the islands. Medical staff numbers 547, with 32 physicians, 193 nurses, and 6 dentists. Among the 32 doctors, 25 are non-Marshal-
Mauritania
lese; all the dentists are also expatriates. For nurses, 44 are expatriates, and 149 are Marshallese. See Also: Birth Defects; Radiation Exposure. Bibliography. “Marshall Islands,” CIA World Factbook,
www.cia.gov (cited June 2007); “Marshall Islands Women’s Health—Nuclear Fallout,” Women’s International League for Peace and Freedom, www.converge.org.nz/pma/RMIwomen04.doc (cited June 2007); “Ministry of Health Annual Report FY2004,” Republic of Marshall Islands, www. rmiembassyus.org (cited June 2007); UNAIDS: The Joint United Nations Programme on HIV/AIDS, “Marshall Islands,” www.unaids.org (cited June 2007). Heather K. Michon Independent Scholar
Marx, Gertie (1912–2004) Gertie Marx was a German-born American physician, known as the mother of obstetric anesthesia for her contribution to developing obstetric anesthesiology as a specialty. She pioneered the use of epidural injections to ease women’s pain during childbirth. She invented an epidural needle that was named after her, and she founded and edited the journal Obstetric Anesthesia Digest. In spite of fierce opposition from the most conservative social and religious quarters, Marx succeeded in transforming obstetric anesthesia. Marx was born in 1912 in Frankfurt, Germany, where she attended primary and secondary school. She enrolled at the Medical School of the University of Frankfurt in 1931. Alarmed at Hitler’s rise to power, she persuaded her whole family to leave Germany and move to Switzerland. After graduating form the University of Bern in 1937, Marx left for the United States where she began her postgraduate training at the Beth Israel Hospital in New York City. She would eventually become the Director of Obstetric Anesthesia of the hospital, a position she held until 1955. In that year, she transferred to the anesthesiology department at Albert Einstein College of Medicine. In both institutions, Marx focused on relieving the pain of childbirth. This commitment made her many enemies. Marx argued that epidural anesthesia con-
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siderably reduced the pain of women while giving birth. At the same time, it was a much safer form of anesthesia than general sedation. Contrary to the latter, epidural anesthesia did not cause respiratory depression and aspiration pneumonia that could lead to death. Some of the opponents of Marx’s argument claimed that epidural anesthesia slowed delivery and provoked an increase in Caesarean sections. Others went as far as citing the Bible to sustain their claims that childbirth should be painful. Many opposed Marx simply because she was a woman and women physicians were neither common nor welcomed in those days. Yet, all these arguments crumbled in the face of Marx’s evidence: although epidural anesthesia could cause a delay in delivery, it was safe for both the mother and the baby. For her contribution to �������������������������� obstetric anesthesiology,� Marx received numerous honors and awards, including the Distinguished Service Award from the American Society of Anesthesiology in 1988 and from the American Society of Regional Anesthesia in 1990. Queen Elizabeth II also presented her with the medal from the Royal College of Anaesthetists in 1993.������ Marx died in New York in 2004 at the age of 91. SEE ALSO: Obstetrics; Obstetrician/Gynecologist; Preg-
nancy.
Bibliography. Jeanne Lenzer, “Gertie Marx,” British
Medical Journal (v.328, 2004), www.bmj.bmjjournals.com/ cgi/content/full/328/7439/586 (cited August 2007). Luca Prono Independent Scholar
Mauritania The West African country of the Islamic Republic of Mauritania, and has borders with Morocco, Algeria, Mali and Senegal. The French established a protectorate over the country in 1903, with it becoming a colony seventeen years later, administered from Dakar. In 1937 there were only nine European medical officers in Mauritania, and there were no major hospitals, with ten subsidiary hospitals, seven maternity centers and eight medical posts, staffed by seven African
1072 Mauritius auxiliary doctors and 23 nurses. With a population of 324,000, there were in total 13 hospital beds in the whole of Mauritania, of which one was reserved for a European patient, and the remainder for Africans. In 1958 Mauritania became an autonomous state, and gained its independence on November 28, 1960. At independence, the healthcare system in Mauritania was still poor, with extreme poverty, and sparse medical facilities. The 8th Conference of the Organization to Fight Endemic Diseases was held in Nouakchott, the capital of Mauritania, from October 15 to 18, 1962. However, in the following year there was still not much of a medical service in the country, with telephone number “11” being for the chief doctor’s home. In 1965 there were less than three doctors per 100,000 people. Most of the medical problems in the country were because of extreme poverty, with waterbourne diseases and those transmitted by insects, such as malaria, being prevalent in all parts of the country except for Nouadhibou and Tiris in the north of the country. There have also been many problems over the drinking of contaminated water, leading to people suffering from cholera and dysentery. During the late 1960s and 1970s the civilian government of President Mokhtar Ould Daddah tried to improve health conditions in the country. This included establishing a National School of Nurses and Midwives in 1966, and a National Health Center in 1977. He also oversaw the establishment of the Mauritania Red Crescent Society. Subsequent military governments in the country have also tried to improve medical care. As a result there are now several hospitals in the country. The main hospital, in Nouakchott, is located to the west of the main part of the city. It has 500 beds and is staffed by expatriate and European doctors. There are also now sub-hospitals at Nouadhibou, Atar and Rosso, and also smaller clinics in 21 other places, as well as pharmacies in all the major towns in the country. In addition, the military operate their own hospitals, although all the hospitals and clinics in the country lack many basic requirements. In 1991 the government launched a campaign against blindness, and during the rest of the decade the average life expectancy remained at 45 for men and 51 for women, with the infant mortality rate, which was 102 per 1,000 live births in the late 1980s, rising to 125 deaths per 1,000 live births in 1993. The
main problems facing the country remain infectious diseases, with measles and tuberculosis still being responsible for many hospital admissions. Poliomyelitis, meningitis, and typhoid are also found around the country. There are also cases of Rift Valley fever, hepatitis and parasitical illnesses. The country still relies on French doctors, and there are 14 doctors and 62 nurses per 100,000 people. See Also: Algeria; Healthcare, Africa; Morocco. BIBLIOGRAPHY. Anthony G. Pazzanita, Historical Diction-
ary of Mauritania (Scarecrow Press, 1996) “Mauritania,” CIA World Factbook, www.cia.gov (cited August 2007).
Justin Corfield Geelong Grammar School, Australia
Mauritius The island republic of Mauritius, located east of Madagascar, in the Indian Ocean, was settled by Arab and Malay seafarers during the 10th century, with Portuguese arriving in 1505. In 1638 the Dutch established a permanent settlement on the island, and it was then occupied by the French who called it Ile de France. The French used the island to develop a sugar industry, reliant on slave labor, and the early healthcare facilities were extremely primitive, and entirely for the European population. The British occupied it starting in 1810, but allowed the French to continue to use their language and French laws. The British established a hospital at St. Louis, the administrative capital of the island, later renamed the National Hospital. In 1898 the Mauritian Medical and Health Department started publishing annual reports on the medical situation in the country. Early medical problems were dominated by malaria, tuberculosis and also cholera, but since World War II, with increased expenditure on healthcare, and on prevention of diseases, there was a massive cut in the number of cases of malaria, tuberculosis and cholera – the malaria eradication program running from 1948 until 1952 being highly successful. In 1968 Mauritius became independent, and three years later, in November 1971 the 3rd Common-
McClintock, Barbara
wealth Medical Conference was held at Mauritius. Visiting doctors commented favorably on the facilities at the National Hospital and the Princess Margaret Orthopedic Center. In 1972 there were 27 doctors on the island. By the early 1980s there were 30 clinics in villages which provided training to people in areas of nutrition and child care, and by 1987 there were 80 doctors covering the island, with a population just over 1 million—Mauritius now has a population of 1,219,220 (2006). However during the period from 1972 to 1987, the number of hospital beds per 100,000 people fell, from 328 to 285. Part of this was because better outpatient care was available, and also there were less people suffering from diseases which needed them to be isolated. By 1993 the entire population of Mauritius had easy access to drinkable water, and the daily calorie intake by 1987 was 124 percent of the United Nations Food and Agriculture Organization recommended requirement. This has risen in recent years leading to problems of people suffering from obesity, diabetes and heart disease. Because of its relative isolation, Mauritius has generally been free of the health problems that have affected many other countries. However, in 2006 and 2007 there have been studies of the prevalence of the Chikungunya virus among travelers to Mauritius. See Also: Madagascar; Malaysia. BIBLIOGRAPHY. T.D. Juwaheer and H. Kassean, “Explor-
ing quality perceptions of Health Care Operations: A Study of Public Hospitals of Mauritius,” Journal of Hospital Marketing & Public Relations (v.16,/1–2, 2006).
Justin Corfield Geelong Grammar School, Australia
McClintock, Barbara (1902–92) American geneticist who won the 1983 Nobel Prize in Physiology or Medicine for her discovery of genetic transposition, or the ability of genes to change position on the chromosome. Throughout her career, McClintock worked on maize cytogenetics, demon-
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strating many fundamental genetic concepts including genetic recombination during meiosis. Barbara McClintock was born on June 16, 1902, in Hartford, Connecticut. When she was six, her family moved to Brooklyn, New York. She graduated from Erasmus Hall High School in 1919 and obtained her B.S. and M.S. degrees in botany from Cornell University. She continued her postgraduate studies in the same subject at Cornell and graduated in 1927. Although as a woman she was not allowed to major in genetics at Cornell, she became the leading member of a small group that was involved in the genetic study of maize at the cellular level. During the 1930s, she held a series of postdoctoral fellowships that allowed her to carry on her research on maize at several prestigious institutions such as the University of Missouri and the California Institute of Technology. After several more years at Cornell, in 1936, she accepted the position of assistant professor at the University of Missouri at Columbia to work with the influential maize geneticist Lewis Stadler. She resigned from this position after only four years because she felt her career was not progressing. In 1941, she was started Carnegie’s Department of Genetics at Cold Spring Harbor in Long Island, New York, on a oneyear contract, which turned into a permanent position the following year. McClintock spent the rest of her career at the Carnegie Institution, where she remained an active researcher also after her retirement in 1967. McClintock died at Huntington Hospital, near Cold Spring Harbor, on September 2, 1992. McClintock devoted her career to the genetics of maize. Focusing on the relationship between plant reproduction and mutations, she discovered important genetic principles, including the physical correlate of genetic crossingover. McClintock demonstrated how genes moved during the breeding of maize plants and also how physical characteristics depended on certain genes. In spite of the skepticism she encountered from some colleagues, McClintock’s career was marked by important awards and by election in influential scientific institutions. In 1944, she was the third woman to be elected to the National Academy of Science. For her groundbreaking discoveries, McClintock was awarded the National Medal of Science in 1971 and the Albert and Mary Lasker Award 10 years later. She was the first woman to receive an unshared Nobel in the category of Physiology or Medicine and the first recipient of the McArthur Foundation grant
1074 Me-Too Drug in 1981. She was also the first woman to chair the prestigious Genetics Society of America. SEE ALSO: Chromosome; DSN; Genetics. Bibliography. Nathaniel C. Comfort, The Tangled Field:
Barbara McClintock’s Search for the Patterns of Genetic Control (Harvard University Press, 2001); Evelyn Fox Keller, A Feeling for the Organism (W. H. Freeman, 1983); Barbara McClintock, “Autobiography,” The Nobel Prizes 1983, ed. Wilhelm Odelberg (Nobel Foundation, 1984), http://nobelprize.org/nobel_prizes/medicine/laureates/1983/mcclintock-autobio.html (cited July 2007).
Luca Prono Independent Scholar
Me-Too Drug A me-too drug, also known as a copycat drug, is a new drug which is very similar to one or more already-existing drugs. The term is generally used in discussions of research and discovery expenditures at pharmaceutical manufacturers: while representatives of the pharmaceutical industry claim that they invest heavily in research which leads to the discovery of new drugs which benefit the public’s health, critics of the industry say that much of that research is devoted to the development of me-too drugs which are not significantly different from drugs already on the market, and thus do not improve human health. According to Marcia Angell, MD, a former editor of the New England Journal of Medicine, about 75 percent of the drugs approved by the Food and Drug Administration in a year are me-too drugs. The creation and approval of me-too drugs has been criticized on many grounds. One is that each new drug is required to be more effective than a placebo, but not more effective than existing drugs on the market, so a me-too drug could be approved for sale in the United States that is known to be less effective than similar, already-available drugs. Second, me-too drugs are sometimes used to extend patent protection by creating a new drug that is a minor variation on a drug whose patent is about to expire. Third, the high profitability of me-too drugs for common conditions such as high blood pressure discourages pharmaceutical manufacturers from
devoting research money to clinically important but less lucrative ventures such as developing orphan drugs (drugs to treat rare conditions). Representatives of the pharmaceutical industry counter that the development of competing drugs lowers costs and gives physicians and consumers more therapeutic choices. See also: Pharmaceutical Industry (Worldwide). BIBLIOGRAPHY. Angell, Marcia, The Truth About Drug
Companies: How They Deceive Us and What to Do About It (New York: Random House, 2004).
Sarah Boslaugh BJC HealthCare
Mead, Margaret (1901–78) Anthropologist Margaret Mead, author of 44 books and over 1000 articles, deeply influenced the field of public health. She was graduated from Barnard College in 1923 and received her Ph.D. from Columbia University in 1929. As an assistant curator and a curator, she worked at the American Museum of Natural History, New York City, from 1926 to 1969. Mead served as executive secretary of the National Research Council’s Committee on Food Habits during the World War II. Starting in 1954, she taught at Columbia University as an adjunct professor. Serving in health-related capacities such as a position on the National Advisory Mental Health Council, Mead called for and modeled interdisciplinary interventions into a diverse array of social problems. Driven by the devastation of the World Wars to tackle global health issues, Mead lead the search for interdisciplinary solutions that combined the insights of public health, biology, psychology, and other fields with what she called the “applied cultural insight” of anthropology. She argued that public health responses that did not account for the cultural context of the health issue were incomplete. In her work on malnutrition, for example, she studied cultural aspects of nutrition including the social meanings attached to specific foods and the influence of social structure on food production and use in order to more fully understand why groups were not eating scientifically recom-
Measles
mended diets. Mead was a founder of the “culture and personality school” of anthropology, which held that cultures are defined by unique patterns of meaning and behavior passed down as tradition. Members of this school looked closely at child rearing to examine the ways that these patterns were passed down to the youngest members of a society, and public health interventions involving childhood education as a means to change health behavior are based on this approach. Thus, Mead fundamentally shaped public health approaches that account for complex intersections of culture and biology. She argued that illness was inextricably connected to cultural as well as biological factors, encouraging the development of holistic public health interventions that attended to both the social and physical causes and effects of health issues. Such holism is exemplified by Mead’s work on mental health and gender, a topic Mead addressed in her first (1928) book Coming of Age in Samoa, and dealt with throughout her career. In Coming of Age in Samoa, Mead argued that the stress associated with adolescence in Western cultures was not biologically universal, but instead rooted in particular patterns of culture, since Samoan adolescents experienced a relatively peaceful transition from childhood to adulthood. Mead continually sought to demonstrate that traits commonly understood to be biological, such as gender roles, were in fact cultural elaborations of biological differences. Mead sought to improve mental health though better understandings of the interactions between biology and culture, speaking frankly about topics like sex and sexual difference in an era when such openness was rare. One of Mead’s greatest influences on the field of public health was the optimism and openness inherent in her work. Mead’s work promoted culturally sensitive and respectful public health interventions, since she argued that culturally patterns were different from, but not necessarily better than, one another. Since Mead believed that destructive human behaviors were culturally learned rather than innate, she also understood them to be changeable; this concept underlies much of the public health work of today. SEE ALSO: Child Development; Mental Health; Public
Health.
BIBLIOGRAPHY. Mary Bowman-Kruhm, Margaret Mead:
A Biography (Greenwood Press, 2003); Jane Howard, Mar-
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garet Mead: A Life (Simon and Schuster, 1984); Margaret Mead, Anthropology: A Human Science (D. Van Nostrand Company, Inc., 1964); Margaret Mead, Coming of Age in Samoa: a Psychological Study of Primitive Youth for Western Civilization (Morrow Quill Paperbacks, 1973). Emily Wentzell University of Michigan
Measles Measles is a highly contagious infectious disease characterized by fever, cough, conjunctivitis, and a distinctive spreading rash. It is caused by an RNA virus of the genus Morbillivirus and the family paramyxovirdae. Documented as early as the 7th Century, measles remains an important human pathogen today. Prior to widespread immunization, measles infected nearly 100 percent of North American children. In under or un-immunized populations in the developing world, measles continue to cause widespread morbidity and mortality. Humans are the only known host for the measles virus. Transmission occurs mainly through direct contact with infected droplets and less commonly through airborn spread. The primary site of infection is the epithelial cells of the nasopharynx. Immediately after infection, the virus replicates within the respiratory epithelial cells and local lymph nodes. The incubation period of measles is between 8 to 12 days from exposure to onset of clinical symptoms. During this period, the virus spreads from the primary site of infection, systemic viremia ensues, and the infected individual becomes symptomatic. The classic rash of measles begins several days after the fever, starts at the head and spreads to cover the body, and is described as red and patchy. Measles is generally self-limited and a full recovery is expected. However, high levels of morbidity and mortality may result. Measles infection may also be complicated by bacterial superinfection of the lower respiratory tract. In the developing world, the diagnosis of measles is generally made on a clinical basis. Diagnosis may also be made through the use of serum serology. There is
1076 Medicaid no percentage of cases may result in measles pneumonia or encephalitis. In both these cases, specific antiviral therapy that is routinely used against measles and treatment is generally supportive. The WHO and UNICEF recommend the use of Vitamin A for all children infected with measles in regions known to have Vitamin A deficiency or measles case fatality rate exceeding 1 percent. Measles immune globulin can be given to exposed individuals within six days of exposure to prevent or decrease severity of infection. Concurrent bacterial infection should be treated with appropriate antibiotics. The measles vaccine is the single most important public health tool for the prevention of measles infection. In North America, the measles vaccine is generally given as a trivalent combination formulation with mumps and rubella (MMR vaccine) at 12 to 15 months of age with a booster dose between 4 to 6 years of age. In the developing world, the WHO and UNICEF Expanded Program of Immunization (EPI) recommends a monovalent (measles only) vaccine at 9 months followed by the trivalent vaccine at 15 months of age. Important gains have been made in reducing the global burden of measles. The measles vaccine was first licensed in the United States in 1963, and since that time, the routine use of the vaccine has contributed to a greater than 99 percent decrease in the incidence of disease. Only a decade ago, measles was responsible for over a million childhood deaths in the developing world each year. The WHO estimates that worldwide, mass vaccination campaigns resulted in a near 40 percent decrease in measles related deaths between 1999 and 2003. The largest reduction was seen in Africa, where deaths due to measles decreased by over 45 percent. Despite these successes, there are still more than 500,000 children who die each year from measles and these deaths are overwhelmingly amongst the poorest and most vulnerable of the world’s children. Each year, there are more than 130 million children born around the globe who, without vaccination, are susceptible to measles infection. Continued vigilance and effort is required to reach the goal of immunizing each of these children and, in doing so, further reduce the burden of this vaccine preventable disease. SEE ALSO: Childhood Immunization; Viral Infections.
BIBLIOGRAPHY. Centers for Disease Control, “Measles,”
www.cdc.gov (cited September 2006); World Health Organization, “Measles,” www.who.int (cited September 2006). Shaun Morris, M.D. Independent Scholar
Medicaid Medicaid is the largest public health insurance program in the United States, providing healthcare to over 55 million people at a cost of $234 billion (according to 2004 data). The federally regulated, state-managed program finances healthcare services for low-income families, disabled individuals, and those seniors who have exhausted their financial assets. Medicaid is a hybrid of state and federal initiatives and jointly financed between the two. The federal government establishes overarching guidelines within which states customize individual programs. As such, each state’s Medicaid program is unique and collectively funded by federal and state governments. Background Medicaid, established as Title XIX of the 1965 Social Security Act, serves all categorically eligible beneficiaries. The program is part of President Lyndon B. Johnson’s “Great Society” social welfare policy initiative; its enactment following several decades of debate over how to meet the healthcare needs of the vulnerable and elderly in the United States. Prior to Medicaid, healthcare services for those unable to afford them were provided through a patchwork of state and local programs, charities, and community hospitals. Currently, Medicaid provides healthcare to 19 percent of the U.S. population and is an integral component of the nation’s rapidly changing healthcare system. The exponential growth in healthcare costs, decline in employer-sponsored health insurance and the changing demographics of American society have further solidified its necessity. Fundamentals of the Program Medicaid is monitored by the federal Centers for Medicaid and Medicare Services (CMS) which es-
tablishes the requirements for service delivery, quality assurance, funding, and eligibility standards. State participation is voluntary. Every state creates eligibility thresholds, benefits packages, and payment rates within the scope of broad federal guidelines. State Medicaid programs are distinct and often have their own program names (e.g., Medi-Cal in California, TennCare in Tennessee). States are reimbursed via block grants from the federal government, the rates of which vary by state ranging from 50 to 77 percent of states’ costs and are contingent on adherence to federal guidelines, including more than 60 federal statutory requirements. Section 1115 of the Social Security Act provides the secretary of Health and Human Services authority to approve experimental, pilot, or demonstration projects that promote the objectives of the Medicaid statute. States may apply for a federal waiver to utilize innovative service delivery systems, expand eligibility to individuals, and/or provide services not otherwise covered under the Medicaid program. Projects are generally approved to operate for a five-year period and states may submit renewal requests to continue the project. Medicaid Eligibility Medicaid is a means-tested entitlement program; to qualify, individuals must meet both categorical and financial eligibility requirements. The CMS sets mandatory guidelines on eligibility criteria, while states have the authority to broaden eligibility beyond these minimum standards, mandatory and optional eligibility groups, respectively. Federal law guarantees eligibility to Aid to Families with Dependent Children (AFDC)-eligible individuals as of July 16, 1996, poverty-related groups, children born after September 30, 1983, current and some former recipients of Supplemental Security Income (SSI), recipients of adoption and foster care assistance, special protected groups, and certain Medicare beneficiaries. Income eligibility requirements vary depending on which categorical criteria an individual meets. States can augment coverage for optional eligibility groups by including other “categorically needy” groups and by expanding the income requirements. Medicaid covers a variety of benefits addressing the needs of its diverse population. State programs
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are required to provide the following: inpatient and outpatient hospital services; prenatal care; child vaccines; physician services; nursing facility services for persons aged 21 or older; family planning services and supplies; rural health clinic services; home healthcare for persons eligible; laboratory and x-ray services; pediatric, family nurse practitioner, and nurse-midwife services; federally qualified health center services; and screening, diagnostic, and treatment services for children under age 21. States can receive federal funds to provide optional services such as diagnostic and clinic services, intermediate care facilities for the mentally retarded, prescribed drugs and prosthetic devices, optometrist services, nursing facility services for children under age 21, rehabilitation and physical therapy services, and home and community-based care to persons with chronic impairments. Impact of Medicaid Medicaid has amplified access to healthcare for lowincome individuals and become a critical tool for the delivery of healthcare to U.S. families. Medicaid, in 2004, provided coverage to 27 million children, 14 million adults, 6 million elderly, and 8 million adults with disabilities. Two-thirds of all program enrollees are in low-wage working families and more than one in every four children in the United States relies on Medicaid for health insurance coverage. The program is the largest purchaser of maternity services, financing roughly two out of every five births. Medicaid also plays a pivotal role in the U.S. healthcare system. The program currently comprises $1 out of every $6 spent on personal health, and finances one-fifth of the nation’s spending on hospital care. Medicaid represents the largest portion of federal spending for people living with HIV/AIDS, accounting for 51 percent of total government spending on HIV/AIDS. Medicaid is also the nation’s primary source of long-term care financing, providing care for 60 percent of nursing home residents and accounting for roughly 50 percent of total long-term care expenditures. SEE ALSO: Centers for Medicare and Medicaid Services
(CMS); Healthcare, U.S. and Canada; Medicare; United States Public Health Service.
1078 Medical College Admissions Test (MCAT) BIBLIOGRAPHY. Centers for Medicare and Medicaid Ser-
vices, Medicaid General Information: Technical Summary (Department of Health and Human Services, 2003); Centers for Medicare and Medicaid Services, Medicaid at-aGlance 2005: A Medicaid Information Source (Department of Health and Human Services, 2005); “Medicaid Resource Book,” www.kff.org/content (cited August 2007); “Medicaid-Medicare Chartbook,” www.kff.org/content (cited August 2007); “Medicare: The Basics,” www.medicare.gov/Basics/Overview.asp (cited August 2007). Duane R. Neff Rebekah M Zincavage Brandeis University
Medical College Admissions Test (MCAT) The Medical College Admissions Test (MCAT) is a standardized examination administered by the American Association of Medical Colleges. The test is required as part of the application for admission to almost all medical schools in the United States. It was traditionally a paper-and-pencil examination; however, the computerized MCAT was introduced internationally in 2001 and within the United States in 2004. Beginning in January 2007, only the computerized version has been used. The MCAT was developed in 1928 as part of an effort to measure aptitude for medical study with the goal of lowering the attrition rate in U.S. medical schools. It has undergone several revisions to accommodate changes in the perceived skills required to succeed in medical education. The first MCAT covered scientific terminology, reading, comprehension, and logic. In 1946, the MCAT underwent its first major revision: The topics included in the new version were verbal skills, quantitative skills, science, and general knowledge. In 1962, the MCAT underwent another major revision, which broadened the scope of general knowledge covered. The third major revision in 1977 expanded the sections covering science, reading, and quantitative skills and dropped the general knowledge question. The fourth major revision, in 1991, added a writing section and integrated quan-
titative skills within the science sections. The current MCAT is intended to assess three general areas: knowledge of biology, chemistry, and physics; facility with critical thinking and problem solving; and writing skills. Scores are reported in four major areas: Verbal Reasoning, Physical Sciences, Biological Sciences, and Writing Sample. The writing sample consists of two essays on specified topics, and the other sections are multiple choice. Because the primary purpose of the MCAT is to identify students who are likely to succeed in medical school, researchers have been interested in examining how well MCAT scores predict outcomes such as medical school grades and United States Medical Licensing Examination (USMLE) step scores. The MCAT has generally been supported as a valid predictor. For instance, Julian looked at students who entered 14 medical schools in 1992 or 1993 and found that MCAT scores were better predictors of both medical school grades and USMLE step scores than undergraduate grade point average (GPA). Additionally, a meta-analysis by Donnon and colleagues of 23 studies found a moderate correlation between MCAT scores and both medical school grades and USMLE step 1 examinations, and also found that the biological sciences subtest score was the best single predictor of medical school GPA. SEE ALSO: Healthcare, U.S. and Canada; United States
Medical Licensing Examination (USMLE).
Bibliography. T. Donnon, E. O. Paolucci, and C. Violato,
“The Predictive Validity of the MCAT for Medical School Performance and Medical Board Licensing Examinations: A Meta-Analysis of the Published Research,” Academic Medicine (v.82/1, 2007); E. R. Julian, “Validity of the Medical College Admission Test for Predicting Medical School Performance,” Academic Medicine (v.82/1, 2007). Sarah Boslaugh BJC HealthCare
Medical Entomology Entomology is the science that studies insects and arthropods. In the case of medical entomology, it spe-
cifically refers to those insects and arthropods that affect human beings and may produce human disease. This complex science comprises the biomedical study of insects and arthropods and their morphology, biology, and systematics. In addition, this field analyzes the epidemiology, prevention, and methods of control of the infections and infestations vectorized and caused by these organisms, but also the insect behavior and life history and those aspects related to relationships between vectors and hosts. Today, the medical entomology as a discipline is closely related to different biomedical sciences such as tropical medicine, medical parasitology, medical virology, public health, and epidemiology, among others. Insects and arthropods can cause direct physical affection to humans (e.g., biting, in this case this includes the so-called external parasites or ectoparasites) as well as being vector of infectious diseases agents (in mechanical and particularly biological vectorizing, e.g., malaria, dengue). New concepts of medical entomology have been recently proposed, according to which this discipline should comprehensively study the effects of insects and arthropods on human health and possible control of these effects. Then, the tasks of medical entomology are markedly widened to embrace cognitively and practically important problems, which have been neglected. The study of entomology comprises the phylum Arthropoda which comprises the following important classes: Pentastomida, Arachnida (scorpions, spiders), Crustacea (crabs, crayfish, copepods), Chilopoda, Diplopoda, and Insecta (insects). Most types of zoological (more than 90 percent of all known species) belongs to this phylum, distinguished by the presence of an exoskeleton. The most medically important of those classes is the Insecta. The class Insecta comprises various groups of arthropods, grouped in orders. The most important orders are Diptera (e.g., mosquitoes, such Anopheles, Aedes, Culex), Hemiptera (e.g., bugs, such as triatomines), Suctoria (fleas), and Anoplura (louse). Other orders included in this class are Coleoptera, Blattaria (cockroaches), Lepidoptera (butterflies), and Hymenoptera (ants, hornets). Genus and species belonging to this class are responsible of vectorize many diseases, such as ma-
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laria, dengue, yellow fever, trypanosomiasis, and viral encephalitis, among others. This represents that those diseases transmitted by these arthropods (socalled arthropod-borne diseases) has a high burden on morbidity and mortality worldwide, particularly in developing and tropical countries. Many epidemiological factors are involved in the figures that those diseases represent year after year, and recently the integration of those factors with ecological ones has emerged in a new science that should support the study of medical entomology, the ecoepidemiology. The tools and approaches offered from this discipline to medical entomology and tropical medicine, as well to public health in affected countries, is related to additional objectives such as prevention, prediction, and forecast of vector-borne diseases. A summary of the most important pathogens and diseases transmitted by insects is shown in Table 1 on page 1080. In the class Arachnida is located the Subclass Acari and its order Acarina (ticks and mites), whose genus and species members are responsible for diseases such as scabies, allergic processes, dermatoses, borreliosis, and ricketsiosis, among others. A summary of the most important pathogens and diseases transmitted by insects is shown in Table 2 on page 1081. Until today, most surveillance studies about insects and arthropod remain with the classical taxonomical identification as the first primary tool for the classification of collected samples, but the recent biotechnological revolution in molecular biology has also impacted the entomology leading to a new discipline, the molecular entomology. This discipline explores new promising tools for the control of vector-borne diseases through genetic manipulation of vectorial competence. The gene transfer technology is hoped to make the pathogens vectors incapable of supporting the development of the parasite or viruses which will ultimately lead to eradication of the etiological agents and the diseases. One particular area that is under study is the development of transgenic mosquitoes with the objective to avoid the transmission of diseases such as malaria. The first significant advance in this way is the current availability of the genome sequencing of Anopheles gambie. Other new discipline in relation to entomology has been the forensic science, which has taken advantage from the fact that necrophagous insects are
1080 Medical Entomology Table 1. Insects’ Vectors of Medical Importance Vectors
Pathogens
Diseases
Anoplura (lice)
Bacteria
Pediculus humanus
Borrelia recurrentis
epidemic relapsing fever
Pediculus humanus
Rickettsia prowazekii
louse-borne typhus
Pediculus humanus
Rochalimaea quintana
trench fever
Diptera (flies)
Viruses
Aedes spp. particularly A. aegypti
DEN virus
dengue
YF virus
yellow fever
A. triseriatus
LAC virus
LaCrosse encephalitis
Culex spp.
SLE virus
St. Louis encephalitis
Culex spp.
JBE virus
Japanese encephalitis
Culex and Culiseta spp.
WEE virus
western equine encephalitis
Various spp.
EEE virus
eastern equine encephalitis
Various spp.
VEE virus
Venezuelan equine encephalitis
Various spp.
RVF virus
Rift Valley fever
Phlebotomus papatasi (and other species)
sand fly fever virus
sand fly fever
Aedes spp. particularly A. aegypti Aedes spp. particularly
Protozoa Anopheles spp.
Plasmodium falciparum, P. malariae, P. ovale, P. vivax
malaria
Glossina spp.
Trypanosoma brucei
sleeping sickness
Phlebotomus spp. and Lutzomyia spp.
Leishmania spp.
Leishmaniasis, Kala-azar, dumdum fever
Nematodes Aedes, Anopheles, and Mansonia spp.
Brugia malayi
brugian filariasis
Culex pipiens, Aedes, and Anopheles spp.
Wuchereria brancrofti
Bancroftian filariasis
Various spp.
Dirofilaria immitis
dog heartworm
Simulium spp.
Onchocerca volvulus
onchocerciasis
Chrysops spp.
Loa loa
loiasis
Hemiptera
Protozoa
Triatominae spp.
Trypanosoma cruzi
Chagas’ disease
In the class Crustacea (e.g., crabs), some members could be involved as intermediary hosts in the transmission of some diseases, such as paragonimiasis, a disease caused by a trematode called Paragonimus.
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Table 2. Acari Vectors of Medical Importance Vectors
Pathogens
Diseases
Bacteria
Liponyssoides sanguineus
Rickettsia akari
rickettsial pox
Leptotrombidium spp.
Rickettsia tsutsugamushi
scrub typhus
Various, particularly Dermacentor spp.
Rickettsia rickettsii
Rocky Mountain spotted fever
Argas spp.
Borrelia anserina
avian spirochetosis
Ixodes scapularis, Ixodes pacificus
Borrelia burgdorferi
Lyme disease
Ornithodoros spp.
Borrelia recurrentis
relapsing fever
Various spp.
Francisella tularensis
tularemia
Virus
Dermacentor andersoni (and other species)
CTF virus
Colorado tick fever
Hyalomma marginatum
CCHF virus
Crimean-Congo hemorrhagic fever
Ixodes ricinus
LI virus
louping ill
Ixodes ricinus (and other species)
TBE virus
tick-borne encephalitis
important in the decomposition of cadavers. The close association between insects and corpses and the use of insects in medicocriminal investigations is the subject of this new discipline, called forensic entomology. Using medical techniques, time since death can only be accurately measured for the first two or three days after death. In contrast, by calculating the age of immature insect stages feeding on a corpse and analyzing the necrophagous species present, postmortem intervals from the first day to several weeks can be estimated. Other uses of entomological data include the toxicological examination of necrophagous larvae from a corpse to identify and estimate drugs and toxicants ingested by the person when alive and the proof of possible postmortem manipulations. SEE ALSO: Epidemiology; Mosquito Bites; Parasitic Dis-
eases; Tick Bites; Travel Medicine.
Bibliography. Paul Beaver, Rodney Jung, and Eddie
Cupp, Clinical Parasitology (Lea & Febiger, 1984); J. L. Benchimol, “Adolpho Lutz and the Origins of Medical Entomology in Brazil,” Parassitologia (v.47/3–4, 2005); Gor-
don Cook and Alimuddin Zulma, Manson’s Tropical Diseases (Saunders, 2003); Pablo Cova, General Principles of Entomology (FVSE, 1974); Becerri Flores and Romero Cabello, Medical Parasitology (McGraw-Hill, 2004) Alfonso J. Rodriguez-Morales, M.D., M.Sc. Universidad de Los Andes Carlos Franco-Paredes, M.D., M.P.H. Emory University
Medical Geography Medical geography is essentially a health research hybrid of geography and medicine. It is a method of study to deal with the geographical aspects of health, disease, and healthcare. Although largely drawing from the social components of human geography, it also often includes physical geographical issues such as the role of climate and locale on human health. Many practitioners have begun to use the term health geography rather than medical geography. This shift has occurred as more attention is being given to
1082 Medical Geography healthcare infrastructure issues, such as accessibility and availability of healthcare resources and how they affect population health status. Geography is an old science that studies the physical and human landscapes and the processes that affect them. The questions revolving around these processes seek to answer how and why they change over time as well as how and why they vary spatially. The discipline is divided into two main categories: human geography and physical geography. Advanced geographic practice and research often involve subcategories of each along with principles from other disciplines (e.g., sociology, urban planning). Physical geography focuses on earth formations and geosystems, whereas human geography explores patterns of populations. This encompasses human, political, cultural, social, and economic components of the social sciences leading to studies that might look at only one variable or they might involve complex multivariable
analysis. Examples of variables are religion, political systems (or geopolitical boundaries), culture, transit system networks, and demographics. A more complex example is urban spaces. The following demonstrates how different variables can be of concern to medical geographers. The metropolitan region of City X is comprised of two different municipalities. One is defined as urban, whereas the other is suburban. These municipalities are physically separated by a large river and each operates its own public transportation system but share coordinated meeting points but lack coordinated schedules. The population demographics of each municipality show substantial differences in age, race, income, and vehicle ownership. The larger suburban municipality, which boasts a younger population with higher incomes, also possesses the bulk of privately held healthcare service locations. These are often not accessible by bus. The urban municipality has a
Medical geography is essentially a health research hybrid of geography and medicine. It is a method of study to deal with the geographical aspects of health, disease, and healthcare around the world.
large publicly funded health system. The medical and health data show health variations between the urban and suburban populations as well as within each of these municipal populations. Medical researchers would probe the variables for a variety of reasons. Medical geographers would likely focus on patterns for better healthcare design. Issues under question might involve the correlation between private insurance and public transportation use. In other words, how many have access to private health services through insurance but cannot utilize these services due to inaccessibility via location? Another research question might consider the location and age of the populations with certain diseases to determine if age is the issue or if other causative factors exist (such as proximity to industrial sites with high air pollution rates). While medical geography is a relatively young discipline, the principles draw on ancient knowledge. The concept that place and location are factors in health extends back to the time of Hippocrates (circa 3rd century bc) when physicians began observing patterns of diseases as they affected certain populations in certain areas. Even before the etiology of disease was understood, there was an awareness of disease spreading across geographic regions such as during the Black Plague pandemic in the 4th century. The value of mapping disease was solidified in 1854 when Dr. John Snow discovered spatial correlations between London cholera deaths and particular water pumps. Snow’s study is foundational to many health research and health practice disciplines, including public health, epidemiology, and medical geography. In recent years, geographic information systems (GIS) software, a data mapping tool, has supported the advancement of the discipline and discovery. This dynamic software supports the visualization of data as it relates to geography and has allowed researchers to more readily observe correlations and discover new insights. There are a variety of qualitative and quantitative approaches to the research as well as different focuses. Some researchers engage a biomedical model where the focus is on disease and illness and often cross over into allied fields of medicine such as epidemiology and public health. Other researchers use social science models and might borrow from other disciplines such as sociology, anthropology, and health economics. Regardless of approach, all are
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concerned with examining the distribution of population health patterns and are complementary. Medical geographers facilitate decision making for healthcare through better understanding of the various factors that affect population health in space and time. SEE ALSO: Epidemiology; Public Health. Bibliography. Laura Lang, GIS for Health Organizations
(ESRI Press, 2000); Melinda S. Meade and Robert J. Earickson, Medical Geography, 2nd ed. (Guilford Press, 2005). Denese M. Neu, Ph.D. HHS Planning & Consulting, Inc.
Medical Helminthology Helminthology is the science whose objective is the study of worms or helminths. In the case of medical helminthology, it refers specifically to those helminths that affect or potentially affect human beings. This complex science comprises the biomedical study of helminths morphology, biology and systematics, and the epidemiology, diagnosis, treatment, prevention, and methods of controlling the infections caused by these organisms. Helminths have been known about and studied since the ancient world; the symptoms now attributed to some helminthic infections appear in papyrus papers of ancient Egypt (c.1600 b.c.e.), although perhaps the first person who reported observations of these organisms was Aristotle, but interpreting Hippocrates’s document; Aristotle spoke of the presence of these organisms in dogs. Most helminths are obligated parasites, living the whole or in part of the life cycle (adults and larvae) in an animal host. The study of helminths comprises two important former subphyla: the Nemathelminths and the Platyhelminths (now classified as phyla in the subkingdom Bilateria). In the Nemathelminths, with many classes, the Nematoda is medically the most important. Infections due to nematodes affect staggering numbers of people. About 2,000 million people harbor these pathogens worldwide, of whom 300 million suffer associated severe morbidity. In 1999, the World Health
1084 Medical Helminthology Organization estimated that these infections represented more than 40 percent of the burden due to all tropical diseases, excluding malaria. In the class Nematoda are included the families Ascaridae, Oxyuridae, Trichinellidae, Angiostrongylidae, Ancylostomidae, Rhabditidae, Filaridae, and Dracunculidae. The most medically important nematodes are summarized in the Table below. In the study of platyhelminths, two classes are medically important: Trematoda and Cestoda. Trematodes are platyhelminths nonsegmented with complex life cycles that involve one or more intermediary hosts (e.g., snails, crabs). In this class, the most important organisms are Schistosoma, Fasciola, Paragonimus, Opistorchis, and Clonorchis. The cestodes are platyhelminths plurisegmented without digestive tract. In this class, it is important to mention the following genuses: Taenia, Echinococcus, Hymenolepis, Dipylidum, and Diphyllobotrium. According to the epidemiological figures mentioned above, soil-transmitted helminths (geohelminths) have become the
most important field of study in medical helminthology. These are intestinal nematodes, part of the development that takes places outside the body (in the soil). Nevertheless, some trematodes, such as schistosomes in Africa, Asia, and Latin America, are responsible for hundred millions of people with hematuria and hepatomegaly, among other clinical features caused by these pathogens. Mother and child infections by soil-transmitted helminths contribute significantly to debilitation, malnutrition, and developmental abnormalities, among other mental and physical complications. Medical helminths are extremely challenging systems for researchers from basics to clinical and epidemiological sciences. To perform the study of these complex parasites, the more widely available and easier tool is the examination of stools. The parasitological evaluation of feces can determine the presence of helminths and protozoa in different forms. SEE ALSO: Epidemiology; Immunology; Medical Entomol-
ogy; Parasitic Diseases; Travel Medicine.
Table: Nematodes of Medical Importance Family
Organism (genus and species)
Ascaridae
Ascaris lumbricoides Toxocara canis Toxocara cati Lagochilascaris minor
Oxyuridae
Enterobius vermicularis
Trichinellidae
Trichuris trichiura Trichinella spiralis
Angiostrongylidae
Angiostrongylus costaricencis Angiostrongylus cantonensis
Ancylostomidae
Ancylostoma duodenale Ancylostoma caninum Ancylostoma braziliensis Necator americanus
Rhabditidae
Strongyloides stercoralis
Filaridae
Wuchereria bancrofti Onchocerca volvulus Mansonella sp. Gnathostoma sp. Brugia malayi Loa loa
Dracunculidae
Dracunculus medinensis
Medical Jurisprudence
Bibliography. Paul Beaver, Rodney Jung, and Eddie
Cupp, Clinical Parasitology (Lea & Febiger, 1984); Gordon Cook and Alimuddin Zulma, Manson’s Tropical Diseases (Saunders, 2003); Becerri Flores and Romero Cabello, Medical Parasitology (McGraw-Hill, 2004); David Heymann, Control of Communicable Diseases in Man (American Public Health Association/Pan American Health Organization/World Health Organization, 2004); Jorge Homez, Parasitology (Editorial de LUZ, 1990). Alfonso J. Rodriguez-Morales, M.D. Universidad de Los Andes Carlos Franco-Paredes, M.D. Emory University
Medical Jurisprudence Medical jurisprudence is the science of the interaction of law and medicine. It is sometimes referred to as legal medicine or as medico-legal medicine or as forensic medicine (criminal cases). Jurisprudence is the science or philosophy of law. Humans experience with rule by tyrants or a totalitarian political party has been universally found wanting. Law in the hands of tyrants or totalitarian political parties becomes an expression of the whim, passion, will and ultimately forced obedience. The rule of reason has been found to be the civilized solution to tyranny and totalitarianism. However, law as rational rules has to be defensible. Understanding the rationality of the rules of reason that are hailed as laws is what will ultimately give authority to law and justify its obedience. As a branch of law medical jurisprudence deals with the rule of reason where medicine and law intersect. It deals with those aspects of law that relate to medicine and the aspects of medicine that relate to law. There is a lengthy list of medical matters that can become the subject of legal interest. However, the establishment of these as legal facts in cases depends upon medical testimony founded upon medical science and the experience of medical practitioners. The application of law to medicine and the application of medicine to legal problems create a large number of cases to which law and medicine may overlap. Medico-legal issues related to the facts of genetics, of
1085
birth, of injury, of disease, of death and of much more. In paternity cases genetic testing can show who is the father or mother of an infant. In the notorious case of the paternity of Dannie Lynn Smith, infant daughter of the late actress and model, Anna Nicole Smith, her paternity was of great interest because of the large fortune the child would inherit. In other cases the establishment of paternity may well lead to child support payments. The discovery of DNA and its exploitation has enabled genetic relationship to be established in legal cases. Defendants have been acquitted or exonerated and released from prison because of genetic evidence. Forensic evidence such as blood, poisons, semen, perspiration, saliva, or other bodily fluids can be gathered. These can demonstrate that the accused could not have been the rapist or the assailant because the genetic evidence from the crime scene was not theirs. Or they can definitely prove to whom they do belong and to the guilty perpetrator of a crime. On the other hand cases involving in vitro fertilization, artificial insemination, surrogacy, or sterilization, or liability in pregnancy are cases in which a physician may have to testify. Some of these may be liability cases, while others may be divorce cases seeking control of frozen embryos. In cases involving disease or injury medical opinion delivered in the course of a trial will become part of the facts of the case. The testimony may also be about matters of the extent of injuries, or the loss of mobility of limbs or the loss of functions such as an eye due to injury, accident or criminal violence. Physicians, nurses and other members of the medical community can be called upon to give expert testimony on medical matters before courts, administrative tribunals, inquests, licensing agencies, boards of inquiry, or boards of certification. They can also be part of the coroner’s office that determines as exactly as possible the time and cause of death. Physicians can also in many cases certify the health of individuals in school sports, of those inducted into public services such as the Peace Corps, or the military. They may also examine persons applying for life or health insurance to determine if there are any pre-existing conditions that should exclude them from the insurance. Or testimony may be given in court to certify the extent of injury or the absence of such in insurance claims cases.
1086 Medical Physics Medical jurisprudence is also concerned with cases involving injuries due to civil liberties violations of prisoners or of civil rights violations of people attacked because of their race, religions, or other characteristics.Mental competency of alcoholics, drug addicts, mental patients, the senile, or others is a common assignment of medical workers. Cases may relate to wills, to brain death, to informed consent for surgical procedures. Physicians certify death whether from natural, accidental or by homicide. Issued of living wills, and other end of life decisions are a matter of medico-legal interest. Euthanasia has become an important issue in recent years. Certifying death is a physician’s routine task. This includes deaths at executions. Forensic medicine focuses on the criminal aspects of injury and death. Privacy is a privilege between physicians and patients. The law of privacy has greatly expanded in recent years. Medical jurisprudence also extends to nurses, pharmacists, and to others. Veterinarians testify on animal medico-legal issues. The administration of controlled substances as pharmaceutical drugs is subject to numerous laws. Physicians, pharmacists, nurses and others are governed by rules to protect patients and the public from drug abuse. A negative side of medico-legal disputes involves physician liability for malpractice. Suits for malpractice can also be sought against other medical or paramedical workers. Medicine is the treatment of the individual. However, public health is the concerned with the health of all individuals in society at large. Laws requiring vaccinations or the quarantining individuals with contagious diseases are part of medical jurisprudence. See also: Death and Dying; Genetic Testing/Counseling. Bibliography. Richard R. Abood and David B. Brush-
wood, Pharmacy Practice and the Law (Jones & Bartlett Publishers, Inc, 2004); ACLM, College of American. Medical Malpractice Survival Handbook (Elsevier Health Sciences, 2007); Bernard Knight and Margy Knight, Legal Aspects of Medical Practice (Churchill Livingstone, Inc, 1992); George D. Pozgar, Legal Aspects of Health Care Administration (Jones & Bartlett Publishers, Inc., 2007); Ben A. Rich, Strange Bedfellows: How Medical Jurisprudence Has Influenced Medical Ethics and Medical Practice
(Springer-Verlag, 2001); William Roach, Medical Records and the Law (Jones & Bartlett Publishers, Inc., 2006); Richard Saferstein, Criminalistics: An Introduction to Forensic Science (Prentice-Hall, 2003). Andrew J. Waskey Dalton State College
Medical Physics Medical physics is an interdisciplinary field that combines the health sciences with physics and engineering. It plays an integral role in modern healthcare, particularly in medical imaging and cancer therapy. Medical physics can be divided into four major categories: diagnostic, therapeutic, medical nuclear, and medical health physics. Diagnostic medical physics involves the use of imaging modalities such as X-rays, fluoroscopy, computed tomography (CT), mammography, magnetic resonance imaging (MRI), and ultrasound. Medical physicists ensure that clinical imaging equipment functions optimally. They also assist other medical professionals in designing proper imaging procedures to achieve the best possible images at the tolerated level of patient exposure to radiation. A fundamental principle of radiological imaging is the minimization of radiation damage. A more detailed image is associated with higher patient exposure to radiation. Therefore, medical physicists must find the best compromise between image quality and the radiation exposure sustained by the patient. Therapeutic medical physics deals with the accuracy of ionizing radiation delivery, which is utilized in cancer therapy. Therapeutic medical physicists work closely with radiation oncologists in designing treatment plans and performing quality assurance of equipment and procedures. They ensure that the radiation dose prescribed by the radiation oncologist is delivered to the desired location (the malignant tissue). Therapeutic radiation can be delivered either through external high-energy beams (usually electron or photon beams produced by a linear accelerator) or through internal radiation sources that are implanted into a patient. An ideal treatment irradiates the tumor while sparing the surrounding normal tissues and critical organs. This is difficult to accomplish in practice, but improved radia-
Medical Research Council
tion delivery techniques are gradually being developed to minimize the deleterious effects of radiation therapy on tissues adjacent to the tumor. Nuclear medicine, unlike diagnostic or therapeutic medical physics, utilizes nonsealed (liquid, powder, etc.) radionuclides. These are applied for diagnostic imaging, such as the use of radioactive tracers, or for therapeutic applications such as thyroid ablation with iodine-131 in thyroid cancer patients. Medical nuclear physicists have been instrumental in the development of novel instruments such as single photon emission computer tomography (SPECT) and positron emission tomography (PET), which are now standards of care. Medical health physics investigates the effects of radioactivity on the human body and is applied in the design of proper treatment procedures as well as in the shielding of radiation facilities in order to protect healthcare workers and the public from excessive exposure. No amount of shielding can completely remove radiation, but it can bring it to an acceptably low level. Medical health physicists are employed by industries dealing with radiation, such as hospitals, nuclear power plants, and factories using radiation for sterilization. Together, these subdisciplines of medical physics have significantly contributed to the diagnosis and/or treatment of many illnesses. Unfortunately, the imaging and therapy techniques that have been developed are quite expensive, and therefore, are not readily accessible even to the poor of the First World, let alone to the residents of the Third World. SEE ALSO: Cancer Radiation Therapy; Diagnostic Imag-
ing; Nuclear Medicine; Radiation Exposure; Radiology.
Bibliography. American Association of Physicists in
Medicine, www.aapm.org (cited January 2007); Laura Lang, GIS for Health Organizations (ESRI Press, 2000). Kevin Shenderov New York University
Medical Research Council The Medical Research Council (MRC), located in the United Kingdom, strives to support the highest qual-
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ity medical research; to develop the skills of researchers and scientists; and to communicate information to the public about research results, with the overall goal being to improve human health. The MRC is funded by Parliament through the Office of Science and Innovation. The agency fosters research in all aspects of medical science, on a broad spectrum of diseases, in hospitals, universities, and its own research facilities. The MRC officially began operations in 1918, when plans were made to form a Ministry of Health for England and Wales to assume responsibility for national health insurance. The scope of the MRC quickly became much broader and, although the agency is funded by the government, the MRC maintains autonomy from governmental control when selecting topics for and methods of research. The MRC works closely with U.K.-based health departments and other collaborative agencies to provide research grants to scientists and to fund university centers focused on improving human health. Twenty-seven scientists affiliated with or supported by the MRC have received Nobel Prizes in ���������������������� Physiology, Medicine, or Chemistry. MRC Technology, a company affiliated with the MRC, partners with researchers to transform data into concrete strategies for improving health. The MRC has five main divisions: Health Services and Public Health Research; Infections and Immunity; Molecular and Cellular Medicine; Neurosciences and Mental Health; and Physiological Systems and Clinical Sciences. The MRC Training and Career Development Board provides research training and then reviews the work of scientists to find ways to further support their efforts. The MRC College of Experts monitors research to ensure that results are top quality, not just when compared with other U.K.-based research but internationally speaking. The MRC Ethics Policy Advisory Committee advises researchers on ethical concerns, including those about using humans as research subjects and about ways to protect the integrity of health information gathered from individuals. Key accomplishments of MRC research include the discovery by Sir Edward Mellanby in 1916 that nutritional deficiencies cause rickets and that cod liver oil provides treatment for the disease; in 1933, that influenza is caused by a virus, not bacteria; in the 1940s, creating clinical trial standards as well as
1088 Medical Tourism transforming the discovery that penicillin is an antibacterial agent into workable pharmaceuticals; in the 1960s, that radiation treats many cancers, with dramatic results for children with leukemia in the 1970s; significant DNA work in the 1960s and beyond; and research breakthroughs in the treatment of heart disease, AIDS, Huntington’s disease, and more in the 1980s and beyond. In 1969, Parliament established an MRC in sub-Saharan Africa, with the goal to become one of Africa’s premier scientific councils. The South African MRC’s task is to improve health and well-being on the continent through exceptional scientific research. The two MRC units, located in Gambia and Uganda, concentrate their research on the enhancement of treatment and the intervention of major communicable diseases in developing countries. SEE ALSO: Healthcare, Africa; Healthcare, Europe. Bibliography. Medical Research Council, http://www.
mrc.ac.uk/index.htm (cited July 2007); South African Medical Research Council, http://www.mrc.ac.za (cited July 2007).
Kelly Boyer Sagert Independent Scholar
Medical Tourism The term medical tourism refers to two distinct, both fairly recent, phenomena: (1) physicians and medical trainees from developed countries who travel to less developed countries to provide medical care, and (2) patients, generally from more developed countries, who travel to less developed countries seeking less expensive medical care or medical procedures (including transplantations) that are unavailable or illegal in their countries of origin. The first type of medical tourism cynically refers to those medical practitioners from Western countries who travel to developing countries for short periods of time to provide medical services, usually for free. While there are no strict criteria that distinguish medical tourists from medical or humanitarian aid workers, medical tourists often have little experience in developing world settings and often combine
medical visits with recreational or cultural activities. Although medical tourists are often motivated by genuine altruism, they often overestimate the need for their assistance or the utility of their specific skill set to problems they encounter. Medical tourists may bring much needed medical supplies or expertise, but they may also inadvertently undermine local healthcare infrastructure or provide inappropriate, incorrect, or even harmful medical care. Medical trainees, both students and postgraduate residents are increasingly seeking formal or elective experiences internationally. Reasons for this include greater flexibility in medical programs, recognition of the value of international experiences, ease of travel, and résumé building. Many medical trainees are interested in developing their technical or improvisational skills in a more challenging setting, while others are interested in observing other medical systems, alternative and traditional therapies, or learning about cross-cultural issues in medicine. Most medical trainee tourists are primarily interested in helping underprivileged communities that may not otherwise have access to medical care. However, the increasing trend of international electives in medical training has be criticized because students are often subject to a lower standard of supervision and may be asked to perform or be looking for opportunities to perform medical activities beyond their level of training. In addition to medical electives from European and North American schools, there is an increasing number of medical schools catering to American or Western students located in developing countries, particularly in Latin America. Clearly, there are significant and challenging ethical issues associated with this phenomenon. The second and much more common meaning of medical tourism refers to individuals who travel to other countries to obtain medical, surgical, or dental care. Individuals with rare or difficult-to-treat diseases have long traveled across international borders seeking advice from the world expert in disease X or Y. Today’s medical tourists may travel for lifesaving surgery, but more often, they travel for cosmetic or elective procedures, seeking cheaper or faster treatment. Skyrocketing medical costs in industrialized countries mean that seeking private medical care may be prohibitively expensive. Alternately, long waiting lists in public healthcare systems can prolong suf-
Medical Tourism refers to patients who travel abroad for procedures that can cost much more in the United States.
fering for treatable conditions. Medical tourism has developed as a popular alternative owing to increased ease and affordability of international travel and recent improvements in medical standards in certain rapidly developing countries. The cost of essential or elective medical procedures in South American or South Asian countries can be one-third to one-tenth the price of similar procedures in the United States. For example, it has become particularly common for U.S. citizens to travel to Latin America and the Caribbean for plastic surgery—from rhinoplasty to liposuction—for $700 instead of $7,000. In Canada, where wait times for hip and knee surgeries can be one year or more, Canadi-
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ans, some of whom may be immigrants from India or China, may seek medical care in those counties while visiting friends and relatives. Others may combine joint replacement or heart valve surgery with a Safari in South Africa or a week of luxury physical therapy and sightseeing in Thailand. A perpetual severe shortage in donor organs for transplantation and international and national restrictions on purchasing organs has led to a situation in which many patients with critical organ failure may wait for years, or die waiting, for organ to become available for transplant surgery. Medical tourism for the purpose of transplantation is a growing industry with a myriad of very complex ethical implications. Dangerous and illegal organ retrieval from poor residents of developing countries continues to occur in order to supply the medical tourism industry with “parts.” The consequences of these activities, as they grow, have important legal and social ramifications. Residents of the Gulf States, for example, have been known to frequent Pakistan, India, Turkey, and Iran to receive organs not available in their countries. In response, Iran has recently enacted legislation to prohibit noncitizens from participating in the world’s only legal compensation for organ donation scheme. Medical tourism companies that facilitate these trips will often arrange pre- and postsurgical care. These organizations, as well as U.S. insurers, have an obvious financial interest in ensuring the continued growth of this phenomenon. As medical tourism is a multibillion-dollar-per-year industry, government ministries in countries such as Singapore, India, and Thailand also have an interest in actively encouraging this practice. Medical tourism is not without risk. One of the most costly aspects of medical care is the quality control infrastructure which assures that equipment, procedures, and personnel are maintained at the highest standard in order to maximize patient safety. The absence or laxity in certain elements of this infrastructure in some international settings has resulted in several recent high-profile outbreaks of infectious disease and is always a risk when one seeks cheaper medical care. Medical tourists also expose themselves to infectious disease by virtue of their travel to a foreign country with different endemic diseases. This is particularly important for immunocompromised or already-ill patients who must undertake longdistance travel under less than ideal circumstances.
1090 MedicAlert Medical tourists must also consider the impact of a poor treatment outcome when they are far from family and friends, and the possible lack insurance should complications develop. Whether for the excitement of medical practice in a developing country or to save $100,000 for coronary artery bypass surgery, medical tourism, in both senses of the term, is a rapidly growing phenomenon worth billions of dollars, involving millions of people. Its effects on global health, medical infrastructures, medical education, and system development cannot be overstated, but neither can the ethical, legal, and professional challenges it presents. SEE ALSO: Severe Acute Respiratory Syndrome (SARS);
Travel Medicine.
Bibliography. Milica Z. Bookman, Medical Tourism in
Developing Countries (Palgrave Macmillan, 2007); Josef Woodman, Patients Beyond Borders: Everybody’s Guide to Affordable, World-Class Medical Tourism (Healthy Travel Media, 2007). Edward T. Ryan, et al., “Illness after International Travel,” New England Journal of Medicine (v.347/7, 2002); S. Venkatesh and Z. A. Memish “SARS: The New Challenge to International Health and Travel Medicine,” Eastern Mediterranean Health Journal (v.10/4–5, 2004). Barry Pakes, M.D. University of Toronto
MedicAlert MedicAlert is a nonprofit company founded in 1956 by Dr. James Collins. Its headquarters is located in Turlock, California, with nine affiliates overseas. It maintains a database of medical information on its members, which is made available to the authorities in the United States and overseas when there is an emergency. Members of MedicAlert provide information to the organization which then provides them with a distinctive metal bracelet or tag that they wear at all times. It can then be used by emergency medical personnel to obtain access to the member’s medical history as well as any special medical needs. Essentially, the need for MedicAlert arose with people from one medical health authority being involved in
an accident in another area, or indeed another country, and crucial medical information is not readily available either because the patient is badly injured and not able to give consent for access to this information, or sometimes because the identity of the patient is not known. There might also be delays in getting hold of this information. When a patient needs immediate medical care, and often may need an operation quickly, the doctors treating the patient would need to know information that may not be obvious. This may include such matters as allergies to particular foods, to latex, to some metals, insects, and even some medicines such as penicillin, as well as any intolerance to particular medications. It is essential for doctors treating an emergency patient to know whether the person has suffered from, or suffers from, Alzheimer’s disease, asthma, autism, diabetes, epilepsy, hemophilia, heart disease, hypertension, or Parkinson’s disease, as well as knowing whether the person has any devices or implants such as a pacemaker, artificial heart valves, stents as a result of angioplasty, and so forth. It is also necessary to know whether the patient is taking any medication. The particular importance of MedicAlert in that field is when patients may be admitted to hospitals in such a state that they may not be able to give details of all the medication they are taking. Traditionally, MedicAlert has used engraved tags or personalized jewelry, depending on the taste of the person, with the use of bracelets and/or necklaces being common. There have also been many people who wear watches from the Citizen Watch Company, which has teamed up with MedicAlert to store information on its watches. The main problem has been in keeping such information up to date and there have been trials involving the use of electronic storage devices using a universal serial bus (USB) interface. To ensure the widest possible coverage, MedicAlert has established affiliates overseas. See also: Geriatrics; Healthcare, Africa; Healthcare, Eu-
rope; Healthcare, U.S. and Canada.
Bibliography. MedicAlert, www.medicalert.com (cited
March 2007).
Justin Corfield Geelong Grammar School
Medicare Medicare is a federal health insurance program administered by the United States government for the elderly and individuals living with a permanent disability. In 2005, Medicare was a source of health insurance coverage for 42.4 million Americans: 35.4 million elderly and 7 million nonelderly people with permanent disabilities. Medicare was originally established in 1965 as Title XVIII of the Social Security Act, designated “Health Insurance for the Aged and Disabled.” The program serves all eligible beneficiaries regardless of income or medical history. The Medicare program plays a vital role in ensuring the health of beneficiaries and the elderly population by covering critical healthcare services, including a newly implemented prescription drug benefit. The program is pivotal to the U.S. healthcare system and integral to the global healthcare market. Medicare accounts for 14 percent of the total U.S. federal budget and is the largest payer for health services in the world. Background As part of the Social Security Amendments of 1965, the Medicare legislation sought to establish a national health insurance program for the elderly to complement the already-existing retirement, survivors, and disability insurance benefits. The enactment of Medicare in the United States followed several decades of debate over how to best meet the healthcare needs of the elderly in the United States. Prior to the 1960s, the U.S. government played a minimal role in the allocation of medical insurance. Medicare, modeled after the existing private health insurance market, was developed during President Lyndon B. Johnson’s administration in the 1960s. Coinciding with the popular ideology of the Great Society and the war on poverty, Medicare was designed as a non-means–tested program serving those considered to be “worthy” (i.e., those unable to work through no fault of their own). As such, its configuration builds on the series of legislative efforts dealing with social insurance programs (e.g., Social Security) and entails sharing the costs across the population by raising funds through payroll withholdings contributed by both employers and employees.
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Medicare Eligibility Medicare, designed as a social insurance program, provides benefits to all eligible beneficiaries regardless of income or medical history. Eligibility is contingent upon age, U.S. citizenship, and contribution into the program through federal tax withholdings from employment. In general, individuals are eligible for Medicare if they (or their spouse) worked for at least 10 years and are U.S. citizens at least 65 years of age. Persons under the age of 65 receiving Social Security Disability Insurance (SSDI) are generally eligible for Medicare after a two-year waiting period. Medicare was originally instituted to aid the elderly, officially defined as persons over 65 years old and eligible for Social Security benefits. In 1973, the program was expanded to include younger beneficiaries living with permanent disabilities. The following groups also became eligible for Medicare benefits: persons entitled to Social Security or Railroad disability cash benefits for at least two years, most persons with end-stage renal disease, and certain otherwise noncovered aged persons who elect to pay a premium for Medicare coverage. The Medicare, Medicaid, and State Children’s Health Insurance Program (SCHIP) Benefits Improvement and Protection Act of 2000 allowed persons with amyotrophic lateral sclerosis (Lou Gehrig’s disease) to waive the two-year waiting period. Fundamentals of the Program Medicare has four distinct parts—A, B, C, and D—each of which is administered and financed differently. Parts A and B, the two primary components, were established with original passage of Medicare in 1965. Parts C and D were created by subsequent legislation, the Balance Budget Act of 1997 and the Medicare Modernization Act of 2003, respectively. Part A, commonly referred to as Hospital Insurance, is currently the largest category of benefit expenditures. Part A covers inpatient hospital services and postacute skilled nursing care. In 2006, approximately 41 percent of Medicare spending was for services in this category. Part A is primarily financed via the Medicare hospital insurance trust fund composed of contributions by current workers and their employers in the form of an uncapped, progressive payroll tax. These payroll tax contributions comprise 85 percent of the Medicare hospital insurance trust fund and the
1092 Medicare remaining 15 percent is financed from the federal government’s general revenue. Enrollment in Part A is automatic for individuals who meet the eligibility requirements for Social Security. Medicare beneficiaries are subject to a one-time deductible (currently just under $1,000) and copayments for services falling under Part A. Healthcare providers are reimbursed by Medicare on a fee-for-service basis for services provided under Part A. Part B, Supplemental Medical Insurance, covers outpatient services such as physician services, outpatient hospital care, home health services, mental health services, short-term care, preventive services, and laboratory and diagnostic procedures. In 2006, 35 percent of Medicare spending was for services covered by Part B. Part B is jointly financed with 75 percent of costs paid by a combination of general federal tax revenues and 25 percent contributed directly by beneficiaries. Beneficiaries’ portion is paid in the form of monthly premiums, roughly $90, annual deductibles, and copayments. Enrollment in Part B is voluntary and is open to those individuals who are entitled to Part A. Part C, the Medicare Advantage program (previously Medicare+Choice), entails the establishment of alternative service delivery options. This component of the program created Medicare HMO Plans that allow beneficiaries the choice of receiving their Part A and B Medicare benefits through HMOs and other private health plans. Part C is part of a broader program strategy to create more choices for beneficiaries. While Medicare HMOs have been an option since the 1970s, the majority of beneficiaries have remained in the traditional fee-for-service program. This was, in part, due to a lack of geographic access to HMO plans for many beneficiaries. The Medicare Modernization Act of 2003 included several provisions to encourage private plan participation and beneficiary enrollment; subsequently increasing the availability and access to Medicare HMO plans for many beneficiaries. In 2006, most beneficiaries have a choice of a range of Medicare Advantage plans. Currently 16 percent of the total Medicare population is enrolled in a Medicare Advantage plan. Part C is voluntary and open to beneficiaries who are eligible for Part A and enrolled in Part B. HMOs providing benefits for enrollees are reimbursed by Medicare on a capitation basis. Part C accounted for 14 percent of Medicare expenditures in 2006.
Part D, Medicare Prescription Drug Benefit, entails a voluntary outpatient prescription drug plan for people on Medicare. Prior to its enactment, outpatient prescription drugs was not a Medicare-covered service. The provisions of Part D are a result of the Medicare Prescription Drug, Involvement, and Modernization Act of 2003. Implemented in 2006, Part D entails that Medicare beneficiaries have the option of purchasing a prescription drug discount card through their Medicare plans. The Medicare drug benefit is twofold: a voluntary discount card and a coinsurance program. Prescription drug plans vary widely but are obligated to meet certain basic requirements instituted by the Medicare Program. Participation in Part D is voluntary for beneficiaries and imposes a penalty for late enrollment for those without drug coverage who sign up in subsequent years. Part D, which is funded by a combination of general revenues, beneficiary premiums, and state payments, accounts for 8 percent of benefit spending in 2006. For the first time since Medicare’s inception, benefits have expanded with the inclusion of an outpatient prescription drug benefit. Part D of Medicare differs from the program in a number of very important ways. All benefits are provided via private plans contracting with Medicare and have a complex coverage structure based on income and expenditures. Second, Part D includes substantial subsidies for individuals with low income and assets as such that it is the first time that Medicare has incorporated means testing into a Medicare benefit. As a result of this new component, Medicare has replaced Medicaid as the primary source of drug coverage for low-income and disabled people with both Medicare and Medicaid (also called dual eligibles). The composition of Medicare spending is projected to shift with the addition of the prescription drug coverage, as Part D is estimated to increase rapidly and account for 20 percent of Medicare spending by 2010. Scope of the Program Medicare is the single largest health insurer in the United States, yet its annual administrative costs consistently operate at less than 2 percent. Medicare finances a growing share of the U.S. health system. Currently comprising 17 percent of the U.S. health expenditure, the program’s impact on the structure of the U.S.
healthcare system is both substantial and manifold. For example, in 2004 Medicare paid for $1 out of every $5 spent on healthcare in the United States. Moreover, as part of its payment structure, Medicare provides supplementary payments to hospitals that function as teaching hospitals, serve a disproportionate amount of low-income individuals, and those located in isolated rural areas. Financing of Medicare The $374 billion (2006 annual budget) program is administered by the Center for Medicare and Medicaid Services (CMS) (formally the Health Care Financing Administration) as part of the United States Department of Health and Human Services. The Social Security Administration is responsible for determining Medicare eligibility and processing premium payments for the program. The financial components of Medicare are handled through two trust funds, one for the Hospital Insurance program and one for the Supplemental Medical Insurance program. These trust funds, which are special accounts in the U.S. Treasury, are credited with all receipts, charged with all expenditures for benefits and administrative costs and cannot be used for any other purpose. As a result of demographic shifts in the U.S. population as well as the rapid rate of increasing medical costs, program expenditures have risen dramatically since Medicare’s inception. In 1965, national health expenditures per person were $205 and by 2003, it grew steadily to reach $5,670. Persons enrolled in Medicare coverage increased from 19.1 million in 1966 to 42.4 million currently, representing a 120 percent increase. Moreover, this trend is expected to continue as the pending retirement of the baby boomer generation (those born between 1946 and 1964) is projected to more than double the number of elderly Medicare beneficiaries to 78 million by 2030. As the elderly population expands in size, so too does their life expectancy, utilization of healthcare services, and disability rates. This growth coupled with the decline in the ratio of tax payers to retirees and the fact that inflation of the healthcare sector continues to outpace general rise in prices threatens to strain the solvency of Medicare’s future financing. Medicare covers a population with diverse needs and substantial vulnerabilities. The elderly comprise 85 percent of all program enrollees, while 15 per-
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cent, nearly 7 million in 2006, are under age 65 and permanently disabled. Currently one in five Medicare beneficiaries is a member of a racial or ethnic minority. Thirty-five percent of beneficiaries have chronic conditions and 14 percent have limitations in three to six activities of daily living. Twelve percent are age 85 and older and nursing home residents make up 5 percent of Medicare enrollees. Many people on Medicare have modest incomes and resources: almost 40 percent have incomes below 150 percent of federal poverty level ($19,600/single and $26,400/couple in 2006). Medicare and Medicaid Because of their low incomes and high medical costs, more than 7 million low-income Medicare participants are enrolled in both the federal Medicare program and individual state Medicaid programs. These dual-eligible beneficiaries are Medicare-eligible individuals who also qualify for state Medicaid benefits on the basis of financial need. This includes those who become eligible for Medicaid by spending down their assets because of high medical costs and the need for long-term care which is not covered under Medicare. Dual-eligible members’ account for roughly 30 percent of Medicare’s annual spending. Impacts of Medicare Along with Social Security, Medicare is one of the most well-liked government programs, long maintaining popularity among the general public as well as its beneficiaries. During Medicare’s 40-year history, the program has considerably altered the lives of seniors and Americans living with disabilities. Because the program provides healthcare coverage, access to quality medical care and critical financial protections against the high costs of healthcare, Medicare has become crucial to the U.S. public and integral to the health of the American population. Access to Healthcare Medicare guarantees health insurance coverage to the elderly and enables access to healthcare; in so doing, it has substantially increased the number of seniors insured. In 1964, the elderly were among the least likely Americans to have health insurance as nearly half of all seniors were uninsured. Yet currently, over 97 percent of seniors are covered by Medicare, mak-
1094 Medicare ing the elderly the most likely U.S. population to have insurance. Through the provision of access to medical care and procedures, Medicare has helped to improve the quality of life for many seniors, allowing them to remain healthier and independent longer. There are, however, still significant gaps in healthcare coverage for beneficiaries, most notably dental, vision, and long-term care.
women, and beneficiaries over age 75. Compounding these income disparities, Medicare beneficiaries with lower incomes are generally in poorer health than their counterparts with higher incomes. Nearly 65 percent of Medicare beneficiaries have annual incomes below $25,000. Roughly 70 percent of Medicare expenditures are on behalf of these individuals.
Minority Health Medicare has played a pivotal role in the provision of healthcare for minority seniors. Prior to Medicare’s enactment, discrimination on the part of hospitals against racial and ethnic minorities was rampant. Many minority Americans were denied access to medical facilities and consequently were forced to rely on separate and often inferior hospitals and clinics to receive medical care. By requiring hospitals that received Medicare funds to be integrated for all patients, Medicare was critically instrumental in expanding access to quality care for minority seniors.
Medicare Beneficiaries with HIV/AIDS Medicare is the second largest source of federal spending on HIV/AIDS care in the United States after Medicaid. There are approximately 100,000 Medicare beneficiaries with AIDS, the most advanced stage of HIV disease. Two-thirds of whom, or an estimated 65,000, are also covered by Medicaid (dual eligible). Medicare spending for AIDS care has increased more than threefold over the past decade, rising from $1 billion in 1995 to $3.2 billion in 2006. As a share of total Medicare spending, however, Medicare spending on HIV/AIDS represents only 1 percent. Medicare will continue to be an important source of coverage for people with HIV/AIDS, and its role in doing so has been expanded by the implementation of the new prescription drug benefit.
Poverty and Economic Security In conjunction with Social Security, Medicare has significantly decreased the number of elderly living in poverty. In 1959, 35.2 percent of Americans over 65 were living below the poverty line and in 2004, roughly 10 percent of seniors were living in poverty. As a group, the elderly spend a higher proportion of their income on healthcare than the general population. This is due to the combination of their higher healthcare costs, on average four times that of the under age 65 population, and lower, fixed incomes. For 80 percent of beneficiaries, at least half of their income comes from Social Security benefits. As a result, they are especially vulnerable to the rising cost of healthcare services. While healthcare spending has risen dramatically since 1965 for all Americans, Medicare beneficiaries are shielded from a substantial portion of that increase and are in turn less likely to become impoverished as a result of illness or disability. Medicare currently pays for about half of beneficiaries’ total healthcare spending. The remainder is financed by beneficiaries themselves, Medicaid, and supplementary insurance. In 2003, four in 10 elderly persons had incomes below 200 percent of the federal poverty level, with higher rates among Hispanics, African Americans,
Medicare Spending and Outlook Although Medicare spending increases each year, the average per capita spending growth rate between 1970 and 2004 was lower for Medicare (8.9 percent) than for private health insurance (9.9 percent) for common benefits (excluding prescription drugs). With the aging of the U.S. population and the new drug benefit, net federal spending on Medicare is estimated to grow from $331 billion to $524 billion in 2011. Moreover, Medicare spending as a share of Gross Domestic Product (GDP) is expected to increase from 2.7 percent in 2005 to 4.7 percent in 2020. Annual growth in Medicare spending is influenced by factors that affect health spending generally, including increasing volume and utilization of services and higher prices for healthcare services. The Medicare program faces many challenges, most prominently the financing of care for an aging population with a declining ratio of workers to beneficiaries. Maintaining benefits for future beneficiaries will require more resources over time. The Part A Trust Fund reserves are projected to be exhausted in
Médicins Sans Frontières
2018. In addition to these fiscal obstacles, others include ensuring the successful implementation of the drug benefit; settling fair payments to providers and plans; improving care for those with multiple chronic conditions; and providing adequate financial protections for those with low incomes and health security for an aging U.S. population. SEE ALSO: Centers for Medicare and Medicaid Services
(CMS); Healthcare, U.S. and Canada; Medicaid; United States Public Health Service.
Bibliography. Centers for Medicare and Medicaid Ser-
vices, Program Information, www.cms.hhs.gov (cited ); The Century Foundation, A Century Foundation Guide to the Issues: Medicare Reform (Century Foundation Press, 2001); B.S. Cooper and S. How, Medicare’s Future: Current Picture, Trends, and Medicare Prescription Drug Improvement & Modernization Act of 2003 (The Commonwealth Fund, 2004); K. Davis, Medicare 40th Anniversary Report for the Commonwealth Fund (The Commonwealth Fund, 2005); M.E. Gluck and K.W. Hanson, Medicare Chart Book, 2nd ed. (The Henry J. Kaiser Family Foundation, 2001); M. Gold, “The Growth of Private Plans in Medicare, 2006,” The Medicare Rx Drug Law (March 2006); M. Gornick, et al., “Thirty Years of Medicare: Impact on the Covered Population,” Health Care Financing Review (v.18/2,1996); Health Care Financing Administration, “Medicare 2000: 35 Years of Improving Americans Health and Security,” Profiles of Medicare Beneficiaries (July 2000); Henry J. Kaiser Family Foundation, Medicare: Medicare at a Glance, www.kff.org (cited July 2006); The Henry J. Kaiser Family Foundation, Medicare: The Medicare Prescription Drug Benefit, www.kff.org (cited June 2006): Medicare: The Basics, www.medicare.gov/Basics/ Overview.asp (cited August 2007); Medicare Chartbook, www.kff.org/content/2001/1622/ (cited August 2007). Rebekah M. Zincavage Duane R. Neff Brandeis University
Médicins Sans Frontières Médicins Sans Frontières (MSF), also known as Doctors Without Borders, is a nongovernmental human-
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itarian aid organization providing care to populations in crisis. MSF was the brainchild of French doctors Bernard Kouchner and Raymond Borel. Kouchner was part of a group of doctors sent to help starving refugees in Biafra during the Nigerian Civil War in the late 1960s. Kouchner and some like-minded colleagues broke a gag order to speak out about the crisis in Biafra, thus bringing it to world attention. At around the same time, Raymond Borel had helped established the Groupe d’Intervention Médicale et Chirugicale en Urgence to provide care in the aftermath of the Bohala Cyclone, which killed 500,000 in East Pakistan in 1970. On December 20, 1971, Kouchner and Borel merged their groups into Médicins Sans Frontières. In 1972, MSF responded to its first natural disaster, an earthquake in Nicaragua which left up to 30,000 dead. In 1975, it dealt with its first refugee crisis, when thousands of Cambodians were forced to flee the Khmer Rouge. In 1976, Lebanon became its first mission to a war zone. Today, MSF has operations in 70 countries. Each year, it assigns around 3,800 medical and nonmedical professionals to sites around the globe, helped on their missions by local staffs totaling about 22,500 people. It runs long-term projects helping groups suffering from AIDS, tuberculosis, and other infectious diseases, but it is best known for its short-term emergency services. Arriving in the aftermath of a natural or man-made disaster, it runs hospitals and clinics, provides clean water and food, hands out shelter supplies, and provides all types of medical care from surgery to psychiatric support. MSF teams include not only doctors and nurses, but also water-treatment experts, logicians, and other types of specialists to provide critical services to people in need. MSF is often first on the scene in a disaster, and it has worked out the logistics of rapid response to uncertain situations. To move the average team of 40 into an area, MSF sends a forward team in to focus on establishing communications, arranging transportation, and assessing the emergency “kits” needed for the mission. To set up their aid stations, teams pull from a list of 50 different such kits, all prepackaged, pretested, and ready for delivery. Emergency health kits, for example, contain supplies capable of treating up to 10,000 people each; surgical kits contain a full mobile operating suite. Each kit is further broken down into “modules”
1096 Medigap Policy or groups of items, such as bandages, that can be resupplied as needed. This protocol has since been adopted by other aid groups. MSF is a signatory to the 1994 Code of Conduct for the International Red Cross and Red Crescent Movement and NGOs in Disaster Relief Programmes, stating that members should provide humanitarian aid without taking sides in any political or religious conflict. Its advocacy role has been a source of conflict within MSF since the beginning; founder Bernard Kouchner left the organization in 1979 largely because he believed publicizing the plight of the oppressed forced the world to get involved and bring about a resolution. MSF believes in témoignage, or “witnessing,” speaking out on behalf of those it serves, but usually tries to steer clear of choosing sides. In 1999, the group won the Nobel Peace Prize for its work. MSF is headquartered in Geneva, Switzerland, and has an administrative staff of 1,000 people. The group receives 80 percent of its funding from private donors, with the remainder coming from corporations and governments. Its annual operating budget is about $400 million. See also: International Federation of Red Cross and Red
Crescent Societies (IFRC).
Bibliography. Médicins Sans Frontières, World in Cri-
sis: The Politics of Survival at the end of the 20th Century (Routledge, 1996).
Heather K. Michon Independent Scholar
Medigap Policy In the United States, certain citizens receive healthcare benefits through the Medicare program. This federal program does not offer 100 percent coverage of all healthcare costs or needs. These gaps in coverage leave many enrollees with unmet insurance needs and/or out-of-pocket healthcare expenses. The Medicare program is designed to meet the healthcare coverage needs of persons 65 and older, persons with a disability, and those with end-stage renal disease (ESRD) who do not have access to private insurance
through an employer or spouse. Persons with these conditions often live on low, fixed incomes and have higher medical care needs. As a result, these uncovered portions of their healthcare can result in lack of access to the care they need and/or be financially devastating. Medigap policies were created to eliminate the excessive financial burden presented by the Medicare program rules. A Medigap policy is a type of private health insurance designed to provide additional healthcare coverage for those enrolled in the Medicare program. These policies, sold by private companies, cover some of costs that are not paid by the original Medicare plan. Medigap policies are generally only available to those enrollees in both Medicare part A and part B. There are several different types that are comparable to the variety of traditional healthcare coverage options. However, Medigap policies must follow federal and state laws in their design, distribution, and coverage. Private insurance companies are not mandated to offer this type of healthcare coverage. Those who sell Medigap policies are not required to offer this coverage to all persons enrolled in the Medicare program based on certain eligibility conditions. Federal law does not require insurance companies to sell Medigap policies to those under age 65. If a person under 65 is enrolled due to a disability or ESRD, they are not entitled to a Medigap policy unless their state law requires private insurance companies to provide this coverage. The rules governing eligibility and availability are complicated. Persons needing coverage should seek advice from the state office governing healthcare insurance or groups such as the American Association of Retired Persons (AARP) who can explain the rules on eligibility and allowed restrictions. Furthermore, insurance companies may voluntarily offer this coverage to any person enrolled in Medicare and are permitted by law to charge different premiums based on conditions. Like employer-offered healthcare coverage, some states have an open enrollment period during which persons seeking Medigap policies may receive best-price options. All Medigap policies are administered in the same way as other private health insurance products. Monthly premiums are charged to the enrollee, and these premium amounts will vary according to the type of policy and conditions. Insurance companies can only sell standardized Medigap policies, meaning
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that they must all have specific benefits for comparison of coverage and costs for purchasing decisions. While costs vary, this is generally the only difference between Medigap policies sold by different insurance companies. All policies must be identified as Medicare supplemental insurance and only cover the person. Coverage does not extend to the spouse and Medigap coverage does not eliminate the Medicare part B premium payment requirement. SEE ALSO: Centers for Medicare and Medicaid Services
(CMS); Geriatrics; Healthcare, U.S. and Canada; Insurance; Kidney Failure and Dialysis; Medicare. Bibliography. U.S. Department of Health and Human
Services, Medigap Policies and Protections: Supplemental Insurance for People with Medicare, publication no. 10139, www.medicare.gov/publications (cited June 2000). Denese M. Neu, Ph.D. HHS Planning & Consulting, Inc.
MEDLINE MEDLINE stands for the Medical Literature Analysis and Retrieval System Online, an international database of life sciences and biomedical information. It has been compiled by the U.S. National Library of Medicine and contains information in the fields of medicine, nursing, pharmacy, dentistry, veterinary medicine, healthcare, and preclinical sciences, and also covers biology and biochemistry fields including molecular evolution. The database is available free on the internet and is fully searchable, with articles taken from refereed and peer-reviewed journals from around the world. A listing on MEDLINE does not mean that the U.S. government or the National Library of Medicine endorses the article. The database contains over 15 million records from about 5,000 selected publications around the world. It covers articles going back to 1950, although about 15,000 citations are for works that were published earlier but cited in indices from 1950 or later. For recent articles, they are included from the moment they are published, although many journals supply MEDLINE
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with details electronically and, as a result, some articles are published cited several days before the journals in which they appear may actually be released. The articles in these publications all have to have been peer reviewed, whereby experts in a particular area study and criticize the articles before publication, rejecting those they deem unsuitable. This system is also known as having the articles refereed. This usually happens with two referees both reading the article— without their identity being known to the submitter or the other referee—and submitting their written reports often within a set time span. With this process, articles in refereed journals are deemed to be of a much higher quality, making MEDLINE of considerably more use to medical professionals and other researchers. All the articles to be included are on the basis of a recommendation by a panel known as the Literature Selection Technical Review Committee, based on scientific policy and quality. The articles listed on MEDLINE are added daily from Tuesday through Saturday. For those added between 1995 and 2003, about 48 percent were published in the United States, although the authors may well be drawn from different countries. Indeed, it is quite common for several authors from different countries to collaborate on a particular article. Altogether, the journals come from 81 countries. Of all the articles in the database, 88 percent were published in the English language, with 76 percent of them having English-language abstracts written by the authors of the articles. SEE ALSO: National Library of Medicine (NLM). Bibliography. Medline, www.nlm.nih.gov/pubs/factsheets/
jsel.html; or http://pubmed.gov (cited July 2007).
Justin Corfield Geelong Grammar School, Australia
Memory Memory is the mental capacity to store and retrieve stored experiences. It is a central part of the human capacity because it is vital to the self-identity of a person. All animals have some kind of memory, but in humans it is unique. Memory is part of the human
1098 Memory capacity to be transcendent in thought. Humans can think of the past, the immediate present and then project thoughts into future possibilities. Memory makes it possible for planning to take place. Without memory organisms can only react to present events in their immediate environment. Memory is not just storing information for retrieval. It is also an intimate part of the learning process. Learning occurs as learners remember ideas, experiences, or other lessons. These learning experiences are not just stored for retrieval; they also transform the learner into a different person than they would be without the learned experience. For example, learning a foreign language or leaning a skill enlarges the capacity of the person, yet it would be impossible to accomplish these tasks without memory. The brain is the center of memories. It however, receives information about experiences in a somewhat random manner. The data of life comes as a stream of information that is not very useful unless it is organized into memories. These are patters of information that are sorted by the brain into retrieval locations in the brain. Every person has his or her own way of sorting experiences into memories. The more organized the sorting is into patterns the more effectively the person will be able to recall the information upon demand. Physical learning is accomplished by the body. It can be trained to repeat an almost endless number of physical actions that can be put to use in play or work. Athletes, soldier, actors, and others engage in repetition of physical actions in order to train the body for the performance of certain tasks. Golfers call the time on the practice tee “grooving their swing.” The expression “practice makes perfect” really means that the brain remembers what the body has done repeatedly even if the physical actions has not been engaged in for some time. Mental memories are those connected with learning ideas or abstract concepts. Counting is a mental activity that is refined into a considerable skill. Concrete experiences of things such as a sheep can be counted when seen as a collection called a flock or a very large flock in Australia called a mob of sheep. The counting is of specific physical things; however, abstraction, which involves grouping things into physical categories (sheep) of abstract categories (flocks, sheep industry) used memories of ideas of perception
to create ideas of abstraction. The mind can draw up and reassemble memories in dramatic ways. It is possible to combine both mental and physical memories and then to employ them in some task. For example an orator may memorize a speech, a singer the lyrics of a song, or an actor memorize their lines. These may not only require physical expression, but emotional expression as well. Additionally, the brain can remember emotions. The brain also stores memories of emotional experiences. The basic emotions—love, joy, anger, fear, and grief—are very important parts of the memories of people. The emotions also have variation that can make the emotional life of people from very shallow to very rich. Those with a low emotional reaction level will miss much of the meaning of life. Emotional complexities such as the perversions of love or anger into envy or hatred can damage the capacity of the personality to remember positive emotions. Much of the work of psychiatrists involves sorting out the emotions of people who have manifested their disorganized emotions into disruptive behaviors. For example leaning to love is a part of developing a wholesome personality. However, those who greedily feed upon receiving love and lack the capacity to return in are likely to have emotional memories that are disorganized. Or a severe fright such as an assault or rape or a violent action occurring in the presence of someone may cause an emotional trauma. The trauma may be so severe that it inhibits them from acting in a normal manner. In effect the emotions of the event are retained but they are too painful to be remembered. The result may be any of a number of possible emotional conditions one of which is amnesia. Forgetting is also a part of memory. Without the capacity of the brain to abandon memories it would not be possible to undo mistakes easily. In addition the mind would be cluttered with a great deal of useless transitory material. However, forgetting is also often more than an inconvenience. It can be a major problem for the healthy or for the ill. It would not be easy to discard the emotional pain associated with many hurtful experiences. It is also useful to not remember severe traumas caused by an accident and the surgery that followed. Memory problems identified as amnesia are extremely important. The amnesia victim is unable to remember information that identifies him or her. Cases
of recovered memory after years of suffering from amnesia have brought the restored memory to life again but their only personal family situation may have radically changes. Damage to the brain can also cause memory loss. The damage may be due to an injury from a blow to the head or it may be due to an illness. Stroke and tumors cause injuries to the brain and interfere with memory. Diseases such as malaria have organisms that injury the brain and can significant damage to the memory even if the malaria victim survives. On a global basis the neurological damage done to millions is a huge public health problem. It is being addressed by many international actors, but it is a challenging problem because the malarial organism keeps developing resistance to malarial drugs. Diabetics with blood sugars out of control can be affected by memory losses. These are usually in the short term. Aging also affects the memory in a variety of ways. The weakening of the circulatory system and the reduced oxygen flow can affect memories. Alzheimer’s disease is a neurodegenerative disease that eventually leads to progressive cognitive deterioration of the brain and therefore of memories. Dementia is common until the advent of death. Forgetting can be measured by using recognition and recall tests. Recall is the reproduction of material learned earlier. Students taking a test over an historical era are engaged in recall. Recognition is tested by presenting a stimulus and then if it is one that was learned earlier. There are two major theories of forgetting—decay and interference. The trace-decay theory says that learned material leaves a trace on the brain which will ultimate fade away if not used repeatedly. The interference theory asserts that everything ever learned will state in the mind unless interfered with by something. One type of interference is called retroactive inhibition and a second type is called proactive inhibition. The latter type of interference can occur if a list of state capitals is learned and then a second list of national capitals is learned. The second list can degrade the memory of the first list. Historically the study of memory was a part of philosophy. At first it was a part of epistemology where it dealt with the questions of knowledge, such as “how do we know.” It was also a part of metaphysical where the question of the nature of the abstract
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Humans are capable of thinking of the past, the immediate present and are then able to project thoughts into future possibilities.
mind or soul was considered. Or it was considered as a part of the rational “mind” that ordered the universe. However, the study of the human personality in its cognitive and emotive capacities became the science of psychology in the 19th century. Like all sciences it then dropped out of philosophy and most psychologists then became experimentally focused. Today the study of memory is the focus of neuroscience and cognitive psychology.
1100 Ménière’s Disease Memory is closely associated with intelligence. There are a variety of definitions of intelligence. None has universal acceptance. But the capacity to learn quickly and to remember long after is a measure of how swiftly the brain works and now well it retains information. Those who learning is denoted as quickly with an excellent memory are assigned an intelligence quotient (IQ) that is high. Others who do not learn quickly or remember well are assigned a low IQ. Neither is a measure of moral worth, although many people make the mistake of believing or acting as if IQ is a measure of personal value. There are six factors that contribute to a good memory. These factors are association, visualization, concentration, repetitions, intensity of impressions, and priority of impressions. Association is the joining together of ideas. Two ideas may not be naturally connected, but if joined then combine to form a new idea. The combination of chocolate and peanuts or peanut butter is the combination of two different foods, which are agreeable together in the taste experiences of many people. Association is used as a mnemonic device when similar more easily remembered things serve as a stimulant to recall information. The association of a string tied around a finger as a memory device is a common memory trick. Visualization is the capacity of the mind to form a mental picture for something that a person wishes to remember. By creating a strong, intense picture the information can be recalled. In order to visualize concentration is also necessary. Concentration is simply attending to something with the intention to remember it. Leaning to concentrate forces the mind to pay attention to what it wants to remember. Repetition is the fourth factor in memory. Repetition is duplicating the words, sounds, smells, ideas or other objects that are being remembered. The duplication is done so frequently that the mind will be able to store the memories in an orderly fashion so that recall of the information is easily accomplished. The fifth factor in memory improvement is intensity of impression. The more exciting or the more dramatic or violent or thrilling is the matter to be remembered the easier it is to recall. The intensity adds to the capacity to remember. Closely associated with the intensity of the impression to be remembered is the last factor in memory
improvement, priority of impressions. The tendency of people is to remember the things that are seen first. Common folk sayings about first impressions being the most lasting ones point to this memory factor. Many mnemonic strategies used these memory factors to help individuals remember information accurately and efficiently. Widely used mnemonic devices include the Acronyms and First-letter Method, the Keyword Method, the Pegword Method, the Method of Loci and the Face-Name Mnemonic. Motivation is also an important factor in memory. The drive to learn in order to achieve some purpose can be a powerful stimulant to the concentration and thus an aid to the memory. According to Sigmund Freud it is a factor in forgetting as well. See also: Alzheimer’s Disease; Brain Cancer; Head and
Brain Injuries; Stroke.
BIBLIOGRAPHY. Michael Fidlow. How To Strengthen Your
Memory (Gramercy Publishing Co., 1961); F. Stephen Hamilton. Mastering Your Memory (Gramercy Publishing Co., 1947); Kenneth L. Higbee. Your Memory: How It Works and how to Improve It (Avalon Publishing Group, 2001); Lawrence C. Katz and Manning Rubin. Keep Your Brain Alive: 83 Neurobic Exercises to Help Prevent Memory Loss and Increase Mental Fitness (Workman Publishing Company, Inc.,1999); Jerry Lucas. Ready, Set, Remember (Memory Press, 1978); Cathryn Jakobson Ramin. Carved in Sand: When Attention Fails and Memory Fades in Midlife (HarperCollins Publishers, 2007); Kevin Trudeau. Mega Memory: How to Release Your Superpower Memory in 30 Minutes or Less a Day (William Morrow and Company, Inc., 1995); James D. Weinland. How To Improve Your Memory (Barnes & Noble, 1957); Philip G. Zimbardo and Ruch, Floyd L. Psychology and Life (Scott, Foresman and Company, 1979. Andrew J. Waskey Dalton State College
Ménière’s Disease Ménière’s disease is a disorder of the inner ear resulting from the distention of the compartment that contains endolymph. Chief symptoms of the disease
Meningitis
include episodic vertigo (lasting from one to eight hours), tinnitus, and sensorineural hearing loss. Ménière’s disease is one of the most common causes of dizziness originating in the inner ear affecting both men and women. In most cases, only one ear is involved, but both ears may be affected in about 15 percent of patients. Ménière’s disease is usually treated with medication, although surgical options are also available in extreme cases. Cause Ménière’s disease is also known as endolymphatic hydrops. It is a disorder resulting from the distention of an endolymph-filled compartment in the inner ear. It is thought that the symptoms of Ménière’s disease are due to the increase of endolymph volume. Although most cases of Ménière’s disease are sporadic, some genetic components related to mutation in the cochlin gene on chromosome 14q12–q13 have resulted in earlier onsets and familial occurrence. Typically, Ménière’s disease inflicts both men and women equally between the ages of 20 and 50. Symptoms and Risks Patients’ chief complaints consist of episodic vertigo (lasting from one to eight hours), tinnitus, and sensorineural hearing loss. These comprises the four symptoms of the “classic Ménière’s disease”: (1) abnormal sensation of movement and dizziness, (2) perception of ringing noise in the ears in the absence of a sound source, (3) fluctuating loss of hearing in the lower frequency range in one or both ears, and (4) the sensation of pressure or fullness in the ears. The symptoms of Ménière’s disease can be debilitating as they involve the sense of balance and orientation to the outside world. The disease can be accompanied by nausea and vomiting. Acute attacks occur in intervals of weeks to years. These attacks are characterized by vertigo, nausea, and vomiting. Hearing loss is progressive and with or without bilateral involvement. As hearing loss deteriorates, vertigo tends to become less severe. The actual pathogenesis of endolymph swelling is unknown; however, it is thought that certain medical conditions such as otitis media (middle ear infection) and injuries to the head can lead to Ménière’s disease. Additionally, environment factors such as the use of aspirin, alcohol, and cigarettes can influence the pathogenesis. It has been found that excessive
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consumption of caffeine and salt may exacerbate the condition in some patients. The first line of treatment for Ménière’s disease is with diuretics, such as hydrochlorothiazide and triamterene, to relieve fluid volume. Antivertigo medications, such as meclizine, and antinausea medication can also be prescribed to give temporary relief. Apart from medical treatments, a change of lifestyle habits such as maintaining a low-salt diet, getting regular sleep, and maintaining a physically active and stress-free lifestyle are also suggested. The patient should also take precautions when driving or climbing ladders if episodes of vertigo occur without warning. If Ménière’s disease is persistent, debilitating, and becomes drug resistant, surgical options are considered to relief fluid buildup in the ear and/or resect the eighth cranial nerve to alleviate symptoms. SEE ALSO: Dizziness and Vertigo; Ear Infections; Tinnitus. Bibliography. American Academy of Otolaryngology—Head and Neck Surgery, “Ménière’s Disease,” www.entnet.org/healthinfo/balance/meniere.cfm (cited February 2007); Mayo Clinic Family Health Book (Collins, 2003); National Institute on Deafness and Other Communication Disorders, “Ménière’s Disease,” www. nidcd.nih.gov (cited February 2007).
James S. Yeh Boston University
Meningitis Meningitis is inflammation of the meninges, the protective covering that surrounds the brain and spinal cord. This inflammation is usually caused by a bacterial or viral infection in the cerebrospinal fluid (CSF), which is contained within the meninges. Other infectious agents, such as fungi, may also cause the disease. The term meningitis represents a wide range of infections, and the bacterial and viral types are markedly different diseases. Furthermore, many different types of bacteria and viruses are capable of causing meningitis, and they may each be associated with distinct patterns of epidemiology, as well as differing signs, symptoms, prognoses, and treatment
1102 Menopause requirements. Therefore, determining the causative agent is a crucial first step in the management of this disease. Patients with meningitis often complain of a fever, headache, and stiff neck, although all three of these symptoms are not always present. Additionally, patients may report nausea, vomiting, decreased appetite, and increased sensitivity to light. To diagnose a specific type of meningitis, the patient’s CSF must be sampled by inserting a needle into the lower back, which is called a lumbar puncture. Examination of the CSF will indicate which infectious agent has caused the disease. Bacterial meningitis is less common than the viral type and is associated with a far worse prognosis. In addition to the above symptoms, patients with bacterial meningitis may also experience confusion and seizures. Meningitis can be caused by a wide range of bacterial species, and patient outcomes vary based on the specific bacterium implicated in the infection. Bacterial meningitis may progress quickly, so treatment with an antibiotic must be started immediately. The specific antibiotic used may differ based on the bacteria that have caused the infection, as specific bacteria are susceptible to different treatments. If untreated, bacterial meningitis can progress to severe seizures, coma, and death. Patients who begin treatment during a more advanced stage of the disease have an increased risk of death; therefore, early diagnosis is essential. Those who survive severe bacterial meningitis may suffer long-term neurological damage, such as intellectual impairment. Viral meningitis, also known as aseptic meningitis, is associated with much better patient outcomes. Initially, viral meningitis may be difficult to distinguish from a common influenza infection. Patients may complain of a fever, headache, and a stiff neck, but they rarely exhibit the more alarming signs and symptoms of bacterial meningitis, such as seizures and confusion. In most patients, viral meningitis will usually resolve without any treatment within one to two weeks. While waiting for the disease to resolve, patients may benefit from medication to alleviate the symptoms of the disease, such as treatment for the associated fever or headache. Additionally, some viruses that cause meningitis may be susceptible to antiviral therapy, and patients with severe symptoms or with compromised immune systems may benefit from an-
tiviral treatment. The prognosis of viral meningitis is excellent, and unlike bacterial meningitis it rarely progresses toward death. Meningitis may also be caused by fungal infections. Although this type is much rarer than bacterial or viral meningitis, it is of particular concern among HIV/AIDS patients. Cryptococcal meningitis, caused by the fungus Cryptococcus neoformans, is an opportunistic infection that is commonly associated with AIDS in the developing world. Because this organism does not normally invade a healthy immune system, cryptococcal meningitis is not often found in AIDSfree patients. The symptoms of cryptococcal meningitis appear similar to those of bacterial and viral varieties; therefore, diagnosis must also be made via CSF examination. Without this information, a diagnosis would be uncertain, because patients with AIDS may have an increased susceptibility to some types of bacterial meningitis, and HIV itself may cause viral meningitis. Treatment for cryptococcal meningitis often includes an initial administration of a potent antifungal agent, followed by regular use of a second antifungal drug to prevent future infections. Treatment should also include management of the underlying HIV infection. Because meningitis represents such wide range of diseases, an accurate diagnosis is essential for effectively treating these infections. In cases where a conclusive diagnosis is not possible, physicians and nurses may choose to err toward a diagnosis of bacterial meningitis and to administer antibiotic therapy, due to the relative severity of this disease. SEE ALSO: AIDS and Infections; Bacterial Infections. Bibliography. D. L. Kasper, et al., Harrison’s Principles
of Internal Medicine, 16th ed. (McGraw-Hill, 2005).
Timothy Sullivan Georgetown University
Menopause Typically occurring between the ages of 40 and 55, menopause is literally defined as “month stop.” It is
the time in a female’s life at which menstrual periods cease, signaling an end to fertility. The average age at which women enter menopause in Western countries is 51. The age at which women in developing countries enter menopause is currently rising in response to health and nutritional improvements. Contrary to popular belief, the age at which menopause begins is not determined by the age at which menstruation begins, the age at which women become pregnant, race, life style, or socioeconomic status. Some researchers believe that smoking, shorter than normal menstrual cycles, and tubal ligation may lead to early onset of menopause. Genetics, multigravidity (the number of pregnancies), and the use of oral contraceptives may be linked to latter onset of menopause. Premature ovarian failure is experienced by women who enter menopause before the age of 35 or who have experienced surgical menopause due to the removal of the uterus and one or both ovaries. Surgical menopause is abrupt rather than gradual, and there is some indication that women who undergo surgical menopause may experience more symptoms of menopause than those for whom the progression is natural. Women’s experiences of menopause may vary according to cultural norms, and reactions are often linked to individual and societal perceptions of women’s roles. In the United States, African American women are more likely than Caucasians to view menopause with equanimity. Women from traditional cultures are more likely than others to express negative attitudes. A 1980 study comparing Japanese and Canadian women, for instance, revealed that 78 of Canadians but only 55.8 percent of Japanese women felt that menopause did not change women’s lives significantly. The following year, a study of five Israeli subcultures examined attitudes on menopause among more than 1,200 women Israeli women who had mothered from two to eight children. The majority wholeheartedly welcomed menopause. Contrarily, those who came from Muslim Arab and Near Eastern Jewish backgrounds, which strictly defined women’s roles, perceived menopause as a negative experience. Stages and symptoms Naturally occurring menopause is composed of three separate stages: perimenopause, menopause, and postmenopause. The World Health Organization defines perimenopause as “the period immediately prior to
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menopause and the first year after menopause. It may begin 10 to 12 years before the onset of menopause and four to five years before menstrual periods cease. Perimenopause is generally characterized by erratic and dramatic shifts in hormone levels that vary from mild discomfort to conditions that threaten quality of life. As estrogen production begins to decline, the pituitary gland starts to release increasing amounts of follicle stimulating hormones (FSH) to jumpstart estrogen production. Consequently, the level of FSH in a woman’s body is the most accurate indicator or the perimenopausal stage. Approximately 10 percent of women suddenly stop menstruating without going through perimenopause. After six months without menstruating, a woman is considered menopausal. After a year, she is considered postmenopausal. Once women reach the postmenopausal state, most if not all of the symptoms related to menopause disappear, and many women enter a period of what anthropologist Margaret Mead (1901–78) called “postmenopausal zest.” Common symptoms associated with menopause include hot flashes, night sweats, anxiety, depression, irritability, insomnia, headaches, palpitations, weight gain, dizziness, decreased sexual interest, and irregular or extremely heavy menstrual periods. Some women experience all the traditional indicators of menopause, while others report only a few, or none at all. The first sign of perimenopause may be a sudden heavy flood of dark clotted blood during menstruation. This flooding may be so severe that normal sanitary products become inadequate. Heavy menstrual periods may also be a symptom of fibroids, noncancerous growths in and around the uterus, or they may be indicative of cancer. If a menstrual period lasts more than seven to ten days, occurs more than twice a month, or requires more than one sanitary pad an hour, immediate medical consultation is essential. More than 75 percent of perimenopausal women experience hot flashes. Caused by declining estrogen levels, hot flashes are characterized by intense body heat and reddened skin. They may last from three to six minutes and are frequently accompanied by head pressure, rapid heart rate, and intense perspiration. They may occur throughout the day. Because they can begin as early as age 40, hot flashes often occur while women are still menstruating. Thus, perimenopausal women can get pregnant. Eighty percent of women
1104 Menopause who experience hot flashes will continue to have them for at least one year. For others, they last from two to ten years. In a minority of women, hot flashes continue throughout their lives. Night sweats are similar to hot flashes, but they often involve drenching perspiration that requires a change of night clothes and sheets. Night sweats are a major cause of sleep deprivation and insomnia in perimenopausal women. They can also be responsible for fatigue, depression, poor motor performance, and decreased concentration. Both night sweats and hot flashes can be triggered by strong emotions, spicy foods, sugar, alcohol, and caffeine. Suggested treatments vary from stress reduction and exercise to peppermint soaks and herbal remedies. In the absence of other perimenopausal symptoms, women who experience night sweats should consult with medical providers to rule out cancer, AIDS, or medication side effects. Three-fourths of menopausal women experience atrophic genital changes that may lead to vaginal dryness, burning, itching, bleeding, and painful sexual intercourse. Treatments include moisturizers, lubricants, and oral or topical hormones. During menopause, both the vagina and uterus shrink, and the pelvic floor may be unable to adequately support the uterus, bladder, and rectum. As a result, menopausal women may experience incontinence when sneezing, bending, or coughing. After menopause, women also become more susceptible to urinary tract infections, cardiovascular disease, and certain cancers. Short-term memory loss is a common complaint of perimenopausal women. It may be a reaction to reduced flow of estrogen to the brain. However, it is difficult to determine how much of the memory loss is associated with menopause and how much is an effect of the aging process. In any case, women are encouraged to keep their brains active, practice good nutritional habits and engage in stress reduction. For some women, menopause is accompanied by depression. In 1986, the Massachusetts Women’s Health Study conducted by epidemiologists Sonja and John McKinley of Harvard Medical School, reported that depression in middle-aged women was not directly related to menopause. Sonja McKinley insisted that most women experienced no major problems with menopause. In a follow-up study published in
1992, McKinley admitted that temporary depression might be a factor during extended periods of perimenopause. The association between menopause and depression continues to be hotly debated within the medical profession. Attitudes In 1900, life expectancy in the United States was 47 years, and many women did not live long enough to experience menopause. For much of history, menopause was rarely spoken of by name. In private, it was referred to as “the change of life.” Although little was understand about menopause, it was perceived as a time of rapid decay; and it was commonly accepted menopausal women were likely to be mentally unstable. In reality, the medical profession lacked a true understanding of the ways in which menopause was experienced by most women and of how it affected overall health. Many physicians believed that the end of fertility marked the end of life as a “woman.” Large numbers of perimenopausal women took to their beds for weeks, months, or even years. Others were admitted to mental institutions, diagnosed with involutional melancholia.” Anthropologist Ruth Benedict (1887–1948) insisted that “involutional melancholia” was simply a result of the societal discontinuities of menopausal women’s lives because they were made to feel as if their lives were over once children left home. Like Margaret Mead, Benedict believed that postmenopausal women continued to grow, making greater societal contributions once they were relieved of the responsibility for raising children. Studies of the 1950s and 60s reported that as many as 85 percent of all women had no symptoms of menopause. Another ten percent were identified as being totally incapacitated. Some researchers suggested that beginning in her twenties, a woman’s mental health continued to decline throughout her life. It was not until the Second Wave of the Women’s movement in the early 1960s that researchers began to pay greater attention to women’s physical and mental health. By the mid-1970s, new studies had begun echoing Mead and Benedict, reporting that women’s mental health actually improved with age. The American Psychiatric Association rejected “in-
volutional melancholia” as a viable diagnosis of mental instability during menopause. Behavioral scientist Bernice Neugarten (1916– 2001) began studying menopause in the 1970s. She contended that contrary to earlier findings, threefourths of menopausal women experienced some degree of discomfort or disturbance but noted that few women sought medical help for menopausal symptoms. However, Neugarten found no basis for assuming that menopause was always accompanied by psychological problems or major life crises. Betty Friedan (1921–2006), the author of The Feminine Mystique (1963) and the founding mother of the Second Wave of the women’s movement, subsequently found that in response to the women’s movement, many women were so busy with jobs and children that they paid little attention to menopause. Baby Boomers By the 1990s, the first Baby Boomers (1946–64) had begun reaching the perimenopausal stage. Because of sheer numbers, women of this generation forced society to take note of menopause in a way that had never happened before. Unlike women of previous generations, Baby Boomers were not intimidated by the medical profession and were, thus, more likely to demand answers and to seek solutions to problems encountered during menopause. In 1991, Gail Sheehy (1937–), the widely acclaimed author of Passages (1976), turned her attention to menopause in The Silent Passage after discovering that so little information was available on the subject. Portions of the book appeared in Vanity Fair, and Sheehy was overwhelmed with letters from women asking for help. She learned that many women were floundering as they entered this poorly understood time of life. Through interviews with women who came from diverse socioeconomic, ethnic, and racial backgrounds, Sheehy discovered that many women were suffering both physically and psychologically as they entered perimenopause. Medical advice was frequently confusing, and family and friends were often unsympathetic. Through interviews with 75 experts, including gynecologists, endocrinologists, neuroscientists, psychologists, psychiatrists, gerontologists, anthropologists, and historians, Sheehy concluded that menopause was the “the last taboo.” Silent Passages
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was instrumental in breaking down that taboo and opening a national conversation on menopause. Treatment The publication of Robert A. Wilson’s Feminine Forever in 1966 initiated a demand for estrogen products to alleviate the symptoms of menopause and delay the signs of aging. The general medical response was to proscribe hormone replacement therapy (HRT) containing estrogen and progesterone for menopausal women. By the 1990s, hundreds of millions of dollars of estrogen products were being sold each year. Many women embraced HRT because in addition to mitigating the negative side effects of menopause, it was touted as reducing risks of cardiovascular disease in menopausal women. Despite the widespread use of estrogen therapy, no major studies were conducted in North America to explore possible carcinogenic affects of HRT. In the 1970s, four separate articles in the New England Journal of Medicine reported a potential link between HRT and uterine cancer. Subsequent studies documented links between HRT and endometrial and breast cancer. By the 1980s, large communitybased studies were providing essential information on both the physical and psychological aspects of menopause. Beginning in 2002, the acknowledgement that hormones were not actually being replaced by HRT led to a preference for the term “menopausal hormone therapy” (HT). The following year, the New England Journal of Medicine reported that incidences of breast cancer had begun declining in the United States in response to a decrease in the use of HT after the release of a National Institutes of Health study in documented the link between breast cancer and hormone therapy. Advocates of homeopathic medicine support the use of alternative products to mitigate symptoms associated with perimenopause. Progesterone transdermal cream, for instance, is touted as being 83 percent effective in reducing the incidence of hot flashes. Soy extracts are believed to reduce both hot flashes and night sweats. Other remedies that have demonstrated varying levels of effectiveness are isoflavones, black cohosh, and St. John’s Wort. Common herbal remedies that show no evidence of effectiveness include evening
1106 Menstruation and Premenstrual Syndrome to menopause as opposed to aging, and determining the health affects of menopause on women of all racial and ethnic backgrounds. See also: AIDS; Breast Cancer; Cancer (General); De-
pression; Gerontology; Gynecology; Incontinence; Pregnancy; Urinary Tract Infections; Women’s Health. Bibliography. N. Datan, et al, A Time to Keep: The Middle
Age of Women in Five Israeli Subcultures (Johns Hopkins University Press, 1981); Editors of Health Magazine, Women Doctors Guide to Health and Healing (Birmingham, Alabama: Oxmoorhouse, 2003); Betty Friedan, The Fountain of Age (Simon and Schuster, 1993); Karl E. Miller, “Depressed Mood Associated with Perimenopause,” American Family Physician (v.74/7, 2006); Gail Sheehy,, Passages: Predictable Crises of Adult Life (Dutton, 1976); Gail Sheehy, The Silent Passage (Random House, 1991); Jo Ann Rosenfeld, ed., Women’s Health in Mid-Life: A Primary Care Guide (Cambridge University Press, 2004); Maria A. Fiatarone Singh, ed., Exercise, Nutrition, and the Older Woman: Wellness for Women (CRC Press, 2000); Susan Krauss Whitbourne and Sherry L. Willis, The Baby Boomers Grow Up: Contemporary Perspectives on Midlife (Lawrence Erlbaum, 2006). Elizabeth R. Purdy, Ph.D. Independent Scholar Menopause typically occurrs between the ages of 40 and 55. It is the time in a female’s life at which menstrual periods cease.
primrose, valerian root, chasteberry, ginseng, and wild yam. The National Institutes of Health Center for Complementary and Alternative Health is in the process of conducting studies to determine the safety and effectiveness of herbal products. Much of the modern research on menopause has been derived from the ongoing Study of Women’s Health Across the Nation (SWAN), which is funded by the National Institute on Aging, the National Institute of Nursing Research, the Office of Research for Women’s Health, the Center for Complimentary Alternative Medicine, and the United States Department of Defense. The multidisciplinary SWAN study, which is taking place at several sites around the United States, focuses on identifying the biology and psychology of menopause, pinpointing changes related
Menstruation and Premenstrual Syndrome The menstrual cycle, also called the ovarian cycle, is the cyclical repeat preparation of the human female reproductive organs for conception. Menarche (the first menstrual period) generally occurs between the ages of 11 and 15. The menstrual/ovarian cycle continues until climacteric or menopause between the ages of 48 and 55. Each woman experiences variations in timing and duration of the cycle from 25 to 35 days, with an average of 28 days, with an average blood loss of 40 mL The severity of inconvenience and symptoms vary. The cycle is hormonally mediated with gonadotropic releasing hormone (GnRH), a hypothalamic hormone that in turn stimulates the pituitary to release follicle stimulating hormone (FSH). This binds to specific receptors on the follicular cells in the
ovaries. Luteinizing hormone (LH) binds to plasma membrane receptors and stimulates the production of progesterone by corpus luteum cells. A feedback loop controls the release of GnRH, based on circulating concentrations of FSH and LH. LH and FSH in turn activate the release of estrogen, testosterone, and progesterone. Prostaglandins are not produced by specialized tissues, but exist in most tissues, including the uterus, and act as a local hormone to trigger uterine contractions. The menstrual or ovarian cycle can be separated into three distinct phases: menstruation, the follicular phase, and the luteal phase. Menstruation begins when hormone secretion signals the end of an ovarian cycle and triggers the disintegration of the endometrium of the uterus. This lining is discharged through menstruation, lasting two to seven days, with an average of four days. Each woman is different and a healthy and natural menstrual flow may vary from watery to thick, pink to dark-red blood, and have color variations from reddish brown to black, which may contain strands of shredded tissue or blood clots. The follicular phase begins with the enlargement of a follicle on the ovary, and ends with the LH peak, 16 to 18 hours prior to ovulation. The ovaries are two almond-shaped organs on either side of the pelvis in the lower abdomen. Ligaments attach the ovaries to the uterus, an upside-down pear shaped organ. Approximately once every 28 days, one of the two ovaries releases an ovum in preparation for fertilization. After menstruation, progesterone levels return to a lower level and remain low. The production of FSH triggers a follicle in the ovary to enlarge forming the Graafian follicle, the maturing cells make estrogen, with a message from the pituitary, the Graafian follicle blisters on the surface of the ovary. At ovulation the Graafian follicle bursts and releases the ovum from the ovary. The ovum, also called an oocyte or egg, is drawn into the fallopian tube or oviduct, an approximately five-inchlong tube to the uterus. If the egg is fertilized, it results in mitotic division and implantation in the uterus for gestation, or pregnancy. The Luteal phase begins with the LH peak and ends with the beginning of menstruation or implanted fertilized ovum (pregnancy). At the time of ovulation, the body temperature increases by 0.5 degrees Celsius. A woman can use this event as a marker to
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predict when she might be able to become pregnant. The empty follicle in the ovary becomes a corpus luteum and secretes estrogen and progesterone. During the Luteal phase, the Progesterone level increases, changing uterine epithelial cells from proliferative to secretory, to provide early nutrition for an implanted fertilized ovum, called a blastocyst. The pituitary continues to supply LH for approximately 10 days. If pregnancy occurs, the hormone Human Chorionic Gonadotropin (hCG) prevents the disintegration of the corpus luteum of the ovary and maintains progesterone production critical for a pregnancy. If pregnancy doesn’t occur, the corpus luteum shrinks and menstruation begins. Recording the Menstrual Cycle Women can keep track of their gynecologic health by keeping a record or chart of dates and duration of menstruation and related health complaints, based on severity. Some women find a diary useful as well to record both physical and emotional well-being, any unusual occurrences, and amount of menstrual flow. Sanitary Products Around the world, women have a variety of options for sanitary products, including feminine pads or napkins (absorbent strips of material, often with sticky strips to attach to underwear and hold it in place), tampons (absorbent material formed into a tube to fit into the vagina), and cups (worn internally to collect the menstrual blood). Washable cloth pads were once the traditional method. Modern materials brought disposable absorbent pads and soft cups. Natural and organic products are available for those who choose them for personal or environmental reasons, as well as reusable menstrual cups made from soft silicone rubber. Toxic Shock Syndrome (TSS), caused by the Toxic Shock Syndrome Toxin-1, produced by certain Staphylococcus aureus bacteria, shows symptoms including sudden high fever, a sunburn-like rash, vomiting, diarrhea, dizziness, muscle aches, and fainting or near fainting when standing up. Early cases of TSS involved women using tampons during menstruation. Super absorbant tampons have been removed from the market because of the risk of TSS. Because of this, the incidence in women has
1108 Menstruation and Premenstrual Syndrome been greatly reduced, and currently almost as many cases involve children, men and non-menstruating women. Menstruation, using barrier contraceptives, and tampon use continue to be risk factors for TSS. If a woman feels any TSS symptoms, she should remove the tampon and get immediate medical attention. TSS can cause organ damage or be fatal if untreated. Studies have shown higher absorbency tampons are more likely to produce TSS syndrome because they dry the vaginal wall, creating small cracks in the skin that allow bacteria to grow. Treatment may include intravenous fluids and antibiotics for any infection. Menstrual Problems and Treatment Options At any point from the time of menarche (first period) to the cessation of menopause, a women may experience irregular symptoms or adverse reactions that may be hormonal in nature, the result of infection, or the result of abnormal cell growth. Unlike the old beliefs that woman’s issues were not discussed, much research has been done and is being continued for treatment. The physician will be able to make a diagnosis, using factors including a description of the duration and amount of flow of the last menstrual period, pain, blood clots, history of illness, medications taken, and performing a pelvic examination to check for pregnancy, masses, or infection. To assist with diagnosis, laboratory testing of cervical smears are done along with and blood work blood testing, Imaging with ultrasound or Magnetic Resonance Imagery (MRI), or hysteroscopy (visual examination) may also be a part of the diagnosis procedure. Irregular bleeding includes menorrhagia (excessive bleeding with possible clots on a regular menstrual cycle), metorrhagia (irregular menstrual cycles or bleeding in between periods), retrograde menstruation (back-up of blood into the peritoneal cavity), vicarious menses (bleeding from sites other than the uterus). Amenorrhea is the absence of menstruation. Primary amenorrhea is the absence of menarche, and secondary amenorrhea is the absence of menstruation for three months in a row. Hormone levels will be checked and appropriate treatment started. The most common causes of secondary amenorrhea are pregnancy and menopause, though hormonal imbalance, excessive dieting, or vigorous exercise may be the cause.
Anovulation is the absence of ovulation. It may be hormonal in nature with high estrogen and LH levels. Obesity may play a role. Women may have normal menstruation, amenorrhea or abnormal bleeding. Dysmenorrhea symptoms include low mid-line wave-like cramping, radiating to the back and upper thighs. Dysmenorrhea falls into one of two categories, primary where the pain is produced by uterine vasoconstriction, atoxia, sustained contractions of the uterus maintained by prostaglandins or secondary where the pain is caused by a clinical reason such as pelvic inflammatory disease (polymicrobial infection of upper genital tract), or endometriosis (growth of endometrium outside the uterus). A physical exam may determine the cause. A physician may suggest the use of analgesic drugs for the pain or oral contraceptives to suppress ovulation. For many of the problems associated with menstruation, oral contraceptives have been found useful. The hormones in oral, parenteral, and implanted contraceptives inhibit pituitary hormone function through the feedback loop to trick the body into stopping ovulating because the hormone levels are increased as they would be during pregnancy. Appropriate diagnosis and treatment options should be discussed between physician and patient. Premenstrual Syndrome Premenstrual Syndrome (PMS) is a hormonal syndrome manifested in an array of physical and psychological symptoms. PMS occurs in the seven to 14 days preceding menstruation and resolves with menstruation. The symptoms may overlap different medical specialties and often the most common diagnosis is Premenstrual Tension (PMT), which includes depression, fatigue, and irritability. Though the psychological issues can appear from mild irritation and confusion to the very serious symptoms of suicidal tendencies and self-mutilation, it would be a disservice to limit the diagnosis to being in a woman’s mind. Being hormonal in nature, PMS is similar to diabetes or thyroid insufficiency in that the psychological issues are symptoms of an underlying hormonal problem of either insufficient levels of progesterone or progesterone receptor activity. The woman may feel like she becomes easily-angered without reason. The effects of mood swings, anger, aggressiveness and violent behavior can have
Mental Health
devastating effects on relationships with partners, children and co-workers. In addition, girls and women may have problems concentrating. Understanding and sympathy from those around her will help her deal with the frustrating symptoms. Those in relationships may wish to seek counseling as well to provide support to the woman with PMS. Additional common symptoms that may be experienced in any combination include headaches (tension or migraine), lethargy, vertigo, skin and mucosal problems, edema, bloating, breast tenderness, and asthma. Depression may be treated with anti-depressants, and other symptoms may be treated with medication as appropriate. Complementary and alternative treatments using diet, stress reduction therapy, exercise, and herbal supplements of black cohosh, red clover, dong quai, ginseng, kava and soy may provide some benefit, though scientific studies have not been conclusive. The U.S. Food and Drug administration does not regulate herbs and supplements as they would pharmaceutical drugs, so caution is advised that strength, purity and safety are not guaranteed. Among the most common PMS treatments today are low doses of the group of anti-depressants that raise the brain hormone seratonin, such as Prozac® and Paxil®. Vitamins and calcium also appear to help the symptoms. Premenstrual Syndrome is a collection of symptoms and each woman is an individual. No one treatment option will treat every sufferer of PMS. Lifestyle changes including quitting smoking, getting enough sleep, exercise, and maintaining a healthy diet to stabilize blood sugar levels may provide relief of some symptoms. Counseling may alleviate the psychological symptoms and effects. Physicians who can provide reassurance, information and discuss options is the first line of finding relief. No longer should PMS be considered a women’s issue, but a health issue. See also: Abortion; Birth Control/Contraception; Cli-
macteric; Depression; Gynecology; Hormones; Nausea and Vomiting; Pregnancy; Psychiatry; Psychology; Reproductive Health (General); Uterine Diseases. Bibliography. “Black Cohosh,” www.nlm.nih.gov/medlin-
eplus/druginfo (cited July 2007); “Chasteberry,” www.nccam. nih.gov (cited July 2007); Katharina Dalton, Once a Month:
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Understanding and Treating PMS (Hunter House Publishers, 1999); Paul A. Fitzgerald, MD, “Endocrinology,” Current Medical Diagnosis and Treatment (Lange Medical Books, 2004); Alan Goldfien, MD, “The Gonadal Hormones and Inhibitors,” Basic and Clinical Pharmacology (Appleton & Lange, 1998); H. Trent MacKay, MD, MPH, “Gynecology,” Current Medical Diagnosis and Treatment (Lange Medical Books, 2004). Lyn Michaud Independent Scholar
Mental Health Mental health is a state of being with cognition, emotion or mood and behavior providing a sense of well-being. Illness and disorders are characterized by alternations in cognition, emotion, or mood and behavior (alone or in combination) causing distress or impaired function. The difference between mental health and mental illness is a fine line and must be understood in the context of each individual’s internal thoughts and external actions and appearance with performance of daily activities like work, school, sleep, self-care, care giving, and social relationships. Types of mental illness include anxiety disorders, mood disorders, psychotic disorders, personality disorders, cognitive disorders, dissociative disorders, somatoform disorders, factitious disorders, substance related disorders, impulse-control disorders, and eating disorders. According to a study by the World Health Organization mental illness accounts for over 15 percent of the burden of disease in market economies like the United States. Mental health complaint statistics provided by the National Center for Health Statistics for 2004 indicate 48 million visits to office-based physicians, 3.7 million emergency department visits, and 5.7 million outpatient hospital visits. According to a 1999 survey, patients with a primary diagnosis of mental disorder accounted for 2.3 million hospital in-patient discharges and 27.4 percent of nursing home residents. Mental health is viewed through three parameters, self perceptions, the observations of others, and societal defined norms. Self perceptions include feelings of well being or of something not being right. A person
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may feel physical distress through heart palpitations, rapid breathing, emotional distress, and feelings of loneliness, isolation, and paranoia, intense unhappiness, and motivation to engage in reckless behavior such as uncontrolled spending of money. In severe instances a person may experience hallucinations or hear harmful voices in their head. Others may notice differences in how a person once behaved, typical behaviors altering to newer and perhaps aberrant behaviors, before the one who is suffering does. A person who once had a normal cleanliness habit begins constant hand washing, uses antibacterial products when someone touches a counter, wears gloves in public, and is afraid of going out in public and becoming infected. Affected persons stay at home more often, care less about their appearance, or fail to perform daily activities. Societal defined norms are the constructed culture of the majority. Persons who adjust and fit in will appear mentally healthy; those who act outside of the norms will be assumed to have instabilities or mental illness. Behavior accepted in one culture may be aberrant in another. Altered states of conscious may be part of a spiritual practice in other cultures possibly indicative of mental illness. Globally recognized signs indicating mental illness are extreme social withdrawal, violence to self, hallucinations (false perception with no grounding in reality), or delusions (clinging to a belief that has been proved false). Historical Myths and Stigma Surround Mental Illness The term mental illness or insanity is surrounded by negative connotations and images of the Inquisition and witchcraft purges when people with mental illness were presumed to be possessed by demons or those practicing witchcraft were thought to be infecting innocents with madness. Mental and physical illnesses were considered punishment for sin. Throughout history the constructs of the time period defined mental health and those who were viewed as aberrant were subjected to tortuous healing methods (electric shock therapy), locked away (mental institutions) or killed (World War II Germany). Myths have perpetuated discrimination and the potential for abuse. While some people believe a person with mental illness is not really ill, others see a
diagnosis of mental illness as a release from responsibility for crimes or aberrant behavior. Treatment for chronic mental illness is suspect because medications don’t cure the illness; they only help manage symptoms (similar to insulin for diabetes) and those suffering from chronic mental illness improve (symptoms and quality of life) with therapy and medications instead of being “cured.” Changing perceptions is the key to removing barriers for those persons who will benefit from mental healthcare. Medical professionals can educate the public and lead by example by providing consistent and respectful care, ensuring privacy, limiting the use of diagnostic labels only as needed by third-party payers, and working with patients and families to create goals, encourage compliance, and provide support. Government officials can improve access to care, enhance funding, and create policy to protect patients and prevent abuse. History of Psychiatric Medicine In 1879, psychology emerged as a medical/scientific discipline and was followed with major breakthroughs and milestones in understanding and treating mental illness. Debate in psychiatry occurs between biology, viewing mental illness in terms of physical cause and response, and psychological perspectives with the perspective of experience and environment. Sigmund Freud began his career in medicine with emphasis on neurology. Between 1887 and 1897 his work with hysterical patients led to psychoanalysis—explaining behavior as a function of unconscious conflicts and motivations, then effecting change through catharsis. His work brought psychoanalysis to the forefront of treatment where it continued as the method of choice into the early 1950s. Behaviorism, identified in the 1930s, entered popular practice in the 1950 and is based on conditioned behavior. Classic conditioning, described by Ivan Pavlov, showed a neutral object paired with a stimulus elicits a response that previously only occurred to the unconditioned stimulus. Operant conditioning, described by B.F. Skinner, is learned behavior associated with consequences. Cognitive therapy started in the late 1950s and early 1960s. Though numerous methods exist under the umbrella of cognitive therapy, Aaron Beck stands out with his view that structuring the world is based on
understanding of the world, which is in turn based on assumptions from prior experience. Biological psychiatry began when nervous chemical control was discovered in 1940 and indicates psychopathology is a matter of biological malfunctions, with drugs being essential to treatment. With an accidental discovery in the late 1940s, lithium was found to affect mania; following this initial event, medication design has kept apace with biological discoveries and becomes more specific as knowledge of how the body works grows. Science behind Psychiatry Psychiatric orders can be caused biochemical disturbances or correlation with internal and external motivators (psychodynamic adaptation, learned behavior, and social or environmental conditions). Biochemical Biologic disorders are usually secondary to an illness or biochemical disturbances of the brain. Genetics plays a role; infants born with Trisomy-21 develop Down’s syndrome characterized by mental retardation. The brain as the central processing unit of the body can also be implicated with damage or destruction to cells. Cell types found in the brain include two broad classifications neurons (for instantaneous intracellular communication) and glial cells (for structure, stabilization, surveillance, and protection). Neurotransmitters are chemicals produced in the nervous system to send messages and are believed to play a role in regulating moods and emotions. Neurotransmitter functions have been correlated with major psychiatric disorders, dementia caused by a cholinergic deficiency, psychosis caused by adrenergic imbalance, and affective disorders and anxiety disorders caused by serotonergic imbalance. Correlation with internal and external motivators The nervous system is made up of the sensory mechanisms (internal representation of external world through somatosensory or touch, visual, auditory, olfactory, and taste), motor systems to manipulate the environment and influence others and association to coordinate the external and internal emotions to drive action. Psychodynamic adaptation disorders instead of having a healthy balance of intrapsychic motivations
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have occurring aberrations. Learned disorders have a pathogenetic mechanism. Somatization disorders are based on positive reinforcement, for example a patient learns being sick gets attention. Personality disorders develop through inherited traits and consequences of life experiences distortions exist when thought patterns, behavior, perception and feelings are inflexible and fail to adjust with changes or stress. Social, cultural and environmental causes create risks for mental illness associated with poverty, war, disaster, rapid social changes, and social isolation with refugee or displacement status. Locating Services In some parts of the world, the single resource is the medical physician or traditional healers, locating appropriate mental healthcare may be difficult. In other areas referrals for mental health services can be obtained from physicians, nurses, employee assistance programs and social workers. Assistance can be found in numerous community networks including religious organizations, support groups, specialized services for veterans, and family counselors. Because of the stigma attached to mental health issues, some people prefer to maintain a sense of privacy using the internet to locate local services by using government provided health sites and telephone directory information. Some key words to search under are mental health, crisis intervention, hospitals, physicians— psychiatry, social services, and suicide intervention. Qualifications and Specialties Whether care is provided in emergency rooms, general care hospitals, specialized hospitals, residential care facilities and nursing homes, the professional care providers for mental health have a variety of extensive experience and specialized training along with licensing to practice. Psychiatrists Psychiatrists are physicians (medical doctors or doctors of osteopathy) who must be licensed to practice medicine in the State of practice in the United States. Psychiatrists specialize in treating disorders associated with mental health. In addition to diagnosing organic causes of mental illness and practice psychotherapy, psychiatrists prescribe medication. People with severe mental illness or who have an
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illness treatable with medication benefit from professional expertise. Psychiatrists in the United States have extensive training including four years of medical school, one year of residency, and three years psychiatric residency. Following graduation from residency psychiatrists may complete written and oral examinations for board certification in psychiatry, although this is not a requirement for the clinical practice of psychiatry. Many professionals belong to the American Psychiatric Association. Clinical Psychologists Clinical psychologists have earned a doctorate in clinical psychology; all 50 of the States in the U.S. require passing licensing exams. Following several years of intensive coursework they have clinical training and supervised clinical practice. Clinical psychologists provide a wide range of psychotherapeutic and testing services in a private practice or provide psychological, personality testing, and therapy, working with a psychiatrist who will determine medical and medication needs. Social workers in the Untied States have a minimum of a master’s degree and have expertise in treating patients with emotional or psychiatric problems. Many choose to work with psychiatrists and in some areas a social worker is the single provider of mental health therapy. Procedures for licensing vary. Psychiatric Nurses Psychiatric nurses complete general nursing training followed by intensive mental health training. They have knowledge of medical causes of mental disorders and understand the action and side effects of medication; psychiatric nurses also educate patients and provide therapy. Nurses interact with patients, observe and document behavior, and collaborate with psychiatrists and other members of the medical team. With graduate training, nurses may choose to have a private practice of psychotherapy. Psychiatric nurses may choose certification by the American Nurses Association. Mental Health Counselors The term counselor doesn’t signify specialized training (school guidance counselors, wellness counselors, diet counselors, etc). Many individuals with profes-
sional degrees in psychotherapy choose to use the term counselor. When seeking a mental health counselor, checking credentials will ensure experience and skills meet the patient’s needs. Pastors provide counseling services and often have completed specialty courses during seminary and theological education to provide crisis intervention and individual, group or family therapy. Ancillary Mental Health Providers Support and assistance for a variety of mental disorders can benefit from community based services. Support groups for specialized medical conditions for patients and their families can provide coping mechanisms and positive reinforcement. The groups are diverse including alcohol and substance abuse, disaster survivors, for patients and survivors of a variety of medical conditions (cancer, diabetes, HIV, etc.), victims of violent crimes, eating disorders, and survivors of other traumatic events. Specialists prepare people to return to work after illness, to re-enter society after being in prison, to adjust to life after military service, and to educate immigrants to the culture they are entering. Host home providers and foster parents are caregivers who provide 24 hour care for person’s with developmental disabilities or children who are victims of neglect. Providers work in coordination with a professional team to provide a safe environment, education and enrichment opportunities, access to medical services and social interaction. Diagnosis Medical physicians are usually the first clinical intervention for psychological disorders. While no test definitively determines mental illness, biological tests exclude organic causes. Including the history and physical clues to the patient’s mental health and well being including appearance, appropriateness of response to questions, and level of consciousness to the surroundings. For symptoms complained about by the patient and for observations for the physician objective and projective tests can determine mental acuity and fantasies or individual modes of thought. MRI can delineate lesions and degenerative diseases, and EEG can detect seizure disorder and differentiate delirium from dementia or depression. Tomographic images show brain activity. The thera-
peutic and diagnostic value of these tests provides either positive evidence of organic cause or the need for more intense psychiatric treatment. Care should be directed toward an objective of cooperation by the patient, setting reasonable goals and allowing for changes along the way to achieve successes, positive behavior not symptomatic behaviors, method, and time frame. Another consideration is the financial burden to the patient. The physician must determine if a psychiatric consult is needed. In severe cases hospitalization may be necessary for self-neglect, violent or bizarre behavior, suicide risk, paranoid ideation or delusions, marked intellectual impairment, and poor judgment. Treatment Options The varieties of mental disorders with varying etiologies require different forms of treatment. When the mental disorder is caused by a medical illness, treating the illness and providing supportive therapy (coping skills) for the psychological symptoms is appropriate. Psychotherapy treats mental illness by talking or communication for symptom relief, behavior change and personal growth. Psychopharmacology treats mental disorders with medication. Psychotherapy Psychotherapy is treatment involving verbal and nonverbal communication between therapist and patient to achieve symptom relief, change problematic behavior and personal growth and self-improvement. The major approaches to treating mental illness by psychotherapy include the psychodynamic approach, the cognitive approach, and the interpersonal approach. In practice, a hybrid of these approaches is used depending on the illness, the individual, and the goals. The psychodynamic approach focuses on the individual to promote personality change through understanding past conflicts, identifying defensive mechanisms, and understanding motivations for problematic behavior as well as providing for release of aggression. This therapy excludes significant others for complete confidentiality. The cognitive approach focuses on the behaviors and provides techniques and skills for correction. The Interpersonal approach focuses on symptomatic relief through solving interpersonal problems and improving interpersonal skills including communication. Significant others
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are included to examine interpersonal roles in the illness and the effect of the illness on the interpersonal relationships. Pharmacologic treatment Drugs to control psychological symptoms include the broad categories of antimanic drugs, antipsychotics, antidepressants, and sedative-hypnotic drugs. With the discovery of lithium in 1949, psychopharmacology began. Lithium an antimanic or mood stabilizing drug controls the mood swings of bipolar disorder though the mechanism isn’t completely understood it affects electrolyte and ion transport, affects neurotransmitters and their release and acts on second messengers (inositol phosphate). Antipsychotics have been used for over 50 years mainly for treating schizophrenia with positive effects on some other psychoses and agitated states with a mechanism of action on the dopaminergic systems in the central nervous system to block dopamine. Antidepressants were developed following the discovery in the early 1950s that the antipsychotic drug Reserpine induced depression and depleted stores of amine neurotransmitters. Early antidepressants or first-generation antidepressants had wide-spread side effects. The second-generation antidepressants show minimal autonomic toxicity and include Selective Serotonin Reuptake Inhibitors and Monoamine Oxidase Inhibitors. A note of caution: using SSRIs and MAO in combination can lead to dangerous increases in serotonin and hyperthermia, muscle rigidity and rapid changes in mental status and vital signs. Sedative-hypnotic drugs are antianxiety drugs. Within this broad category are benzodiazepines, barbiturates, nonbarbiturate sedative-hypnotics, sedatives and hypnotics. Benzodiazepines act on gamma-aminobutyric acid (GABA) the major inhibitory neurotransmitter in the central nervous system. Newer sedatives do not act on GABA and binds to specific receptors. With the wide array of medications available and the common expectation of patients that there is a pill for everything, polypharmacy and abuse are potential. With that in mind, the primary physician (psychiatrist or medical doctor) must coordinate with other medical providers including pharmacists
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to ensure patients are receiving only the medication needed, not being on medications that may interact with each other and to prevent the patient from getting multiple prescriptions from different physicians to prevent dependence. Alternative or Complementary Treatment Options Traditional medicine is science based on experiments to validate hypotheses and develop theories. Traditional medicine is biologically and physiologically based with the presumption that illness can be cured through chemical, surgical or technological methods. Alternative medicine, sometimes called complementary or holistic factors in the environment, social interactions and lifestyle concepts already integrated into psychiatry. Hypnosis and biofeedback have become a part of mainstream psychiatry. However, without scientific evidence, including clinical trials and research showing the effectiveness of alternative therapies, medical professionals remain skeptical of alternative therapies even when the alternative therapy is a good fit with traditional therapeutic methods. Complementary and alternative medicine approaches vary. Those gaining acceptance include diet and nutrition, mind/body control, medical practices from other cultures, manual healing, pharmacological or biological treatments, bioelectromagnetic application and herbal medicine. Diet and nutrition provides the energy requirements, vitamins and minerals needed for metabolic and biochemical processes. Mind/body control induces relaxation through external sensory techniques of art, dance, sound and music, meditation, laughter and breathing. Medical practices from other cultures rely on centuries old healing techniques: acupuncture, ayurveda, homeopathy, Native American, naturopathy, Oriental medicine and shamanism. These techniques may be based on one or a combination of techniques: flow of energy, treatment of like with like, natural medicines and spiritual practices. Manual healing includes acupressure, chiropractic, massage therapy, osteopathy, posture and touch. These specialties restore the physical body to relieve secondary symptoms associated with illness by proper alignment of the musculo-skeletal system, the ma-
nipulation of soft tissue and body surfaces to improve circulation and tone and nerve stimulation to release the body’s own neurotransmitters and endorphins. Pharmacological or biological treatments as alternative therapies use traditional medicine techniques in non-traditional ways with antioxidants, chelation of metals to remove them from the bloodstream, and metabolic therapy. Bioelectromagnetic applications include light therapy, magnetic fields and electrostimulation. Herbal medicine uses plants known for their health-giving properties. Some countries include herbal medicine in pharmacopeias and pharmacists compound and dispense herbs in the same way they dispense medication and drugs. While herbal medicine is gaining support and research is being done to validate claims, herbal medicines are not regulated to ensure concentration and safety. Healing rituals, while not a part of mainstream Western medicine, in some religious communities and cultures around the world, driving out demons (exorcism) may be considered a form of mental healing. A witchdoctor or shaman may be called to perform a ritual or ceremony for healing. The inflicted person often takes part in the ritual and plays an active role in their healing. Personal beliefs play a role in the outward healing. In Western cultures, similar practices include prayer and the laying on of hands. Common Mental Illnesses Of the more than 300 specific mental illnesses detailed in the Diagnostic and Statistical Manual of Mental Disorders used to identify mental illness based on signs and symptoms, a few of the mental illnesses are common. Attention Deficit Hyperactivity Disorder (ADHD). Common in children and adolescents (in the United States affecting between 2 to 20 percent) ADHD is characterized by a short attention span, impulsive behavior, poor concentration and excessive motor behavior. Treatment with a combination of psychopharmalogic medication and psychotherapy may be necessary. Prognosis and outcome is similar to other hyperkinetic disorders and is influenced by other factors including aggression, delinquency and anti-social behaviors. Anxiety Disorders. A range of related illnesses where anxiety is the primary symptom, they affect as
many as 25 percent of the U.S. population, with greater prevalence in women. Anxiety disorders include panic, obsessive-compulsive disorder (OCD), General anxiety disorders, social phobias and specific phobias. Effective treatment requires clarifying the problem and helping the patient view it in proper context. Providing supportive care and prescribing sedatives for a limited time improves symptoms. Prognosis is a return to satisfactory function. Related to anxiety disorder, post-traumatic stress disorder (PTSD) is characterized by reexperiencing a traumatic event (common to military personnel who have witnessed atrocities or been exposed to combat, rape victims or victims of abuse), avoidance and emotional numbness, constant hyperarousal, panic attacks, aggression, depression and substance abuse. Symptoms may begin soon after the event or triggered after a latent period. Autism. Autism first appears in childhood and is characterized by complete self-absorption, inability to relate to others and removal from reality with a wide range of behaviors including being unable to communicate with others, and rocking. Though epidemiologic evidence suggests the incidence is low (less than 1 percent) the extent of care needed is high. The goals of treatment are to increase socially acceptable behavior, self-care skills and aid in the development of communication skills. While no psychopharmalogic medication is specific for autism, some medications can be used to modify and diminish some symptoms. Prognosis is long and difficult, with 25 percent of autistic adults remaining severely handicapped and requiring long-term care. Alzheimer’s Disease and Dementia. These appear in older people over age 65, and are characterized by multiple cognitive defects that impair memory. They affect an estimated 4 million Americans. While dementia appears to have a biological cause and symptoms can be lessened with medications and psychotherapy, a cure is not possible in all cases or without timely treatment. Alzheimer’s patients continue to have a marked decline until death. Depressive disorders. Major, dysthymic, and bipolar disorders occur in 2 to 25 percent of the population, with prevalence across age, gender, ethnic and class distinctions. Causes, though not definitive, are made up of a variety of biological and psychosocial factors. Depression occurs secondary to many medi-
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cal diagnoses. Treatment is directed toward multiple goals after safety is guaranteed. Hospitalization may be necessary if the patient shows tendencies toward selfharm. Further treatment focuses on a variety of psychopharmalogical and psychotherapeutic treatments showing effectiveness. Prognosis is good for improved quality of life, even with chronic symptoms. Suicide. Suicide is a mental health emergency resulting in the intentional taking of one’s life. The reported number of suicide deaths in the United States in 2004 was 31,647. With psychological, biological and social factors involved suicide may be precipitated by substance abuse, depressive disorders, schizophrenia and other mental disorders or to escape difficult situation or seemingly unbearable circumstances. Suicide is preventable with intervention and treatment. The most commonly recognized warning sign leading to help includes a verbalized suicidal ideation. Treatment includes preventing self-harm by removing means of suicide, identifying and treating the underlying cause, along with psychotherapy to change behavior. Schizophrenia. Schizophrenia is a serious chronic psychotic condition characterized by loss of contact with reality and disturbances in thought, mood and perceptions. Symptoms include delusions and hallucinations. Several subtypes of schizophrenia are based on frequent phenomenon. Treatment with medications is successful, though side-effects are common. Psychotherapy, depending on the patient’s status and history, and including family therapy, can alleviate patient stress and improve coping skills. Current medications are effective at alleviating hallucinations or delusions, but are not as effective in correcting abherrant behavior. Eating disorders. These disorders involve anorexia, bulimia, pica, and disturbances in eating. Reported in 4 percent of adolescent and young adults, the average age of onset is the mid-teens and early 20s. Causes are psychological and biological, with an additional factor being a societal emphasis on thinness. Starvation changes the body’s metabolism and has further medical consequences. People with eating disorders may have coexisting major depressive disorders. Treatment may be difficult because of a patient’s secretiveness and lack of cooperation, though some eating disorders resolve spontaneously. In extreme cases, hospitalization is necessary.
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Psychotherapy, with patient and family involvement for behavior changes, and medication to treat core symptoms are often used. Prognosis is variable with favorable outcomes stemming from a desire to change, and less favorable outcomes when there is a continued preoccupation with food and body weight. Global Implications for Mental Healthcare Continued research into causes of mental disorders and better understanding of how to appropriately treat each mental illness, and developing medications with fewer side-effects will allow more people to lead higher quality lives in community settings. While developed countries provide a range of mental health services that is not the case throughout the world. A limited numbers of psychiatrists, limited hospital beds for psychiatric patients, and lack of support networks mean many patients do not receive professional care for mental health. Reform and expansion of mental health resources will improve access to care. See Also: Alzheimer’s Disease; American Psychological
Association (APA); Anorexia Nervosa: Anxiety Disorders; Attention Deficit Disorder; Autism; Bipolar Disorder; Child Behavior Disorders; Dementia; Depression; Pharmacology; Psychotherapy; Schizophrenia; Stress; Suicide. Bibliography. John Clements, Mental Health Care Spe-
cial Report (Political Research Inc, 2002); Harold I. Kaplan, MD and Benjamin J. Sadock MD, Synopsis of Psychiatry Behavioral Sciences and Clinical Psychiatry, 8th ed. (Lippincott Williams & Wilkins, 1998); “Mental Health: What’s Normal, What’s Not,” www.mayoclinic.com/health/mental health (cited August 2007). Lyn Michaud Independent Scholar
Mercury Mercury is a toxic metal that can cause neurological damage, especially during early development. Mercury is transported globally in the atmosphere and seafood consumption is an important source of exposure.
The health effects of mercury depend on the dose, timing, and route of exposure, as well as the form of mercury involved. Mercury exists in three chemical forms: elemental or metallic mercury, inorganic mercury salts, and organic mercury. Inhalation of elemental mercury can harm the brain and kidneys, but inorganic mercury compounds have relatively limited ability to enter the brain, according to the U.S. Agency for Toxic Substances and Disease Registry (ATSDR). Unlike other forms of mercury, the most common type of organic mercury, methylmercury (HgCH3 or MeHg), is readily absorbed into the body through ingestion. Incidents resulting in high methylmercury exposures have shown that neurotoxicity is the most prominent outcome and prenatal and childhood exposure can be particularly hazardous. Neurological damage observed in adults and especially children in Japan in the 1950s was linked to consumption of fish contaminated by industrial dumping of mercury into Minamata Bay. Mercury-contaminated grain in Iraq in the early 1970s had similar effects. Epidemiologic studies in the Faroe Islands and the Seychelles have informed risk assessment. Exposure to methylmercury typically occurs through seafood, but the original mercury source can be far removed from the fish. ATSDR’s Toxicological Profile for Mercury says that between 33 and 66 percent of mercury releases are estimated to come from anthropogenic sources and “approximately 80 percent of the mercury released from human activities is elemental mercury released to the air, primarily from fossil fuel combustion, mining, and smelting, and from solid waste incineration.” This mercury can travel long distances globally and ultimately deposit in soil or bodies of water in a distant region. Aquatic microorganisms convert elemental mercury into methylmercury, which bioaccumulates in the tissues of fish and biomagnifies so higher levels of the food chain have higher concentrations of mercury. Thus, large predatory fish can have high methylmercury levels. Although reducing mercury emissions might have a greater impact, interventions often focus on consumer education. The U.S. Environmental Protection Agency (EPA) and Food and Drug Administration (FDA) issued a Joint Advisory in 2004 recommending that women who are or may become pregnant, nursing mothers, and young children avoid eating shark, swordfish, king
Meta-Analysis
mackerel, and tilefish—the species typically containing the most mercury—and eat up to 12 ounces per week of a variety of fish including no more than 6 ounces of albacore tuna. Advocacy groups have urged governments to take stronger action. The EPA, FDA, and the Joint Food and Agriculture (FAO)/World Health Organization (WHO) Expert Committee on Food Additives (JECFA) point out that the risks of consuming seafood contaminated by methylmercury or other toxins should be weighed against seafood’s nutritional benefits, particularly in the context of varying regional diets. Seafood contains nutrients including omega-3 fatty acids, which have been associated with cardiovascular benefits. Certain fish, such as wild salmon, typically have low mercury but high omega-3 fatty acid levels. In addition to diet, occupational exposure to mercury in gold mining and other industries is a hazard in certain regions. People can be exposed to high levels of elemental mercury from amalgam dental fillings, but the potential health effects of these fillings have been debated. SEE ALSO: Environmental Health; Environmental Toxicol-
ogy; Food Safety; Nutrition; Pollution.
Bibliography. Agency for Toxic Substances and Disease
Registry, “Toxicological Profile for Mercury,” CAS # 743997-6, March 1999, www.atsdr.cdc.gov/toxprofiles/tp46. html (cited August 2007); Environmental Protection Agency and Food and Drug Administration, “What You Need to Know about Mercury in Fish and Shellfish: 2004 EPA and FDA Advice For: Women Who Might Become Pregnant, Women Who Are Pregnant, Nursing Mothers, and Young Children,” March 2004, www.cfsan.fda.gov/~dms/ admehg3.html (cited August 2007); National Academy of Sciences, Toxicological Effects of Methylmercury (National Academy Press, 2000). Leora Vegosen Johns Hopkins University
Meta-Analysis Refers to the statistical integration, or synthesis, of data from more than one study for the purpose of analy-
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sis. The findings from any one study become the unit of analysis within the meta-analysis framework. The studies will usually have been conducted by different researchers at different points in time and in different locations, but will have enough methodological similarity to warrant integration. Meta-analysis has been used in a wide range of scholarly areas, including education research, and is gaining increasing importance in epidemiology and related clinical fields. By combining data from myriad investigations, a meta-analysis may result in increased precision of estimates and a greater confidence in hypothesis testing. This is particularly important when single studies have utilized relatively small sample sizes, and as such would be hindered by low statistical power and a high likelihood of type II errors. Meta-analysis usually involves the comparison of odds (and odds ratios) or risk (and relative risk ratios). In clinical research, meta-analysis has been a very powerful technique for addressing issues of interpretation when the results of studies contradict one another; by combining the data in one analysis, more robust and conclusive interpretations may be generated. The studies included in a meta-analysis need to have similar measures and methodologies. As such, meta-analysis has been particularly useful when analyzing the results of randomized clinical trials, rather than quasi-experimental or observational designs. Additionally, problems associated with Simpson’s paradox and publication bias may limit the usefulness of meta-analysis. Simpson’s paradox refers to a situation wherein a statistical association observed in separate analyses may be lost when the studies are combined. This concern is particularly relevant for meta-analyses that combine data from studies with very large differences in sample sizes. Publication bias may be a problem for meta-analysis because it represents a selection bias. That is, studies that find a statistically significant association are more likely to be published than studies that find no significant differences in outcome; as such, the source studies for a data analysis will be filtered through the publication bias. This may result in false-positive findings. However, the inclusion of nonpublished studies in a meta-analysis also brings to light potential problems, given that they have not passed a peer-review process. The Cochrane Database of Systematic Reviews is a well-known effort that prepares, disseminates, and periodically updates meta-analyses of randomized
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controlled trials on health interventions. Contemporary textbooks in biostatistics typically include discussion of techniques associated with meta-analysis, including discussion of techniques for standardizing outcome measures, conducting sensitivity analysis, and presenting results (e.g., box-plots). SEE ALSO: Evidence-Based Medicine; Randomized Clini-
cal Trial.
Bibliography. Matthias Egger and George Davey Smith,
“Meta-Analysis: Potential and Promise,” British Medical Journal (v.315/7119, 1997); Diana Petitti, Meta-Analysis, Decision Analysis, and Cost-Effectiveness Analysis (Oxford University Press, 2000). Fernando De Maio, Ph.D. Simon Fraser University
Metabolic Disorders Metabolic disorders are disorders that affect production of energy within cells due to abnormal chemical reactions in the body. Metabolism consists of anabolism (the build-up of substances) and catabolism (the breakdown of substances). Metabolism takes place via certain metabolic pathways catalysed by various enzymes. An alteration of enzyme function or a deficiency in enzyme levels result in metabolic disorders. The result is an inability to break down complex molecules from e.g. food and transform into energy, there may be a consequent build up of toxins. The largest classes of metabolic disorders include disorders of carbohydrate metabolism(e.g.s lactose intolerance, glycogen storage diseases); amino acid metbaolism (e.g.s phenylketonuria, ,maple syrup urine disease); fatty acid oxidation and mitochondrial metabolism disorders; porphyrin metabolism disorder; purine and pyrimidine metabolism disorder; steroid metabolism disorder; mitochondrial dysfunction; perizosmal dysfucntion and lysosoaml stroage disorders. Most metabolic disorders are genetic in origin; however, some are acquired. These can be caused by a variety of sources including toxins, infections and diet. Hereditary disorders of metabolism include the
condition phenylketonuria. This is an autosomal recessive disorder characterised by a deficiency of the enzyme phenylalanine hydroxylase; this enzyme metabolises phenylalanine to the amino acid tyrosine, enzyme deficiency hence leads to build up of phenylalanine which can be detected in urine. The disorder is characterised by the presence of mental retardation and seizures. Another hereditary genetic metabolic disorder is lipidoses, this group of disorders are characterized by defects of the digestive system that impair the way the body uses fat from the diet. The various types of lipidoses include Fabry’s disease, Tay Sachs disease, Gaucher’s disease, Krabbe’s disease, Niemann-pick disease, Refsum’s disease and Wolman’s disease. Fabry’s is an x-linked condition present in males. In this condition there is a defective gene which causes deficiency of the enzyme alpha-galactosidase A leading to accumulation of a glycolipid called globotriaosylceramide to accumulate within blood vessels and organs. The disease is characterised by pain and discomfort within the extremities. Patients may also have dark red-purple spots on the skin between the abdomen and knees. Tay-Sachs disease is an autosomal recessive metabolic disorder commonly associated with Ashkenazi Jews. It is a fatal condition caused by a deficiency of the enzyme β-hexosaminidase A. This enzyme found in lysosomes normally breaks down a naturally occurring lipid called GM2-ganglioside. The enzyme deficiency leads to a toxic accumulation of GM2-ganglioside in the cells of the nervous system leading to neurodegeneration. Gaucher’s disease is a lipid storage disease which occurs due to the deficiency of a lysosomal hydroxylase called glucerebrosidase resulting in deposition of glucocerebroside (glycosphingolipids important in muscle and cell membranes) in cells of the macrophage-monocyte system. The disease is characterized by various symptoms such as hepatomegaly (enlargement of the liver), splenomegaly (enlargement of the spleen), hypersplenism (increased activity of the spleen caused by e.g. anaemia), osteoporosis and yellow-brown skin pigmentation. Krabbe’s disease is a rare, fatal disease caused by deficient activity of the lysosomal hydrolase galactosylceramide beta-galactosidase. This enzyme normally degrades galactosylceramide (found in myelin which
Methamphetamine Abuse
insulates central nervous system), and beta-galactose– containing sphingolipids. The deficiency in enzyme causes build up of undigested fats leading to demyelination and degeneration of mental and motor skills. Niemann-Pick disease is lipid storage disease causing lipid accumulation in organs such as spleen, liver, lungs and brain. The disease has 4 related types. Type A is the most common type; it is characterized by jaundice, hepatomegaly, and brain damage. Type B is characterised of hepatomegaly and splenomegaly with a sparing affect on the brain. In types of A and B insufficient activity of the enzyme sphingomyelinase leads to a toxic accumulation of sphingomyelin, a fatty substance present in every cell of the body. Types C and D are characterized by a defect that disrupts the transport of cholesterol between brain cells. Refsum’s disease, a disease characterised by the accumulation of the fatty acid phytanic acid in plasma and tissues occurs due to a deficiency of phytanoylCoA hydroxylase (PhyH), a peroxisomal enzyme catalyzing the first step of phytanic acid alpha-oxidation. Phytanic acid is found in foods such as dairy products, white bread and rice. This condition affects the nervous system, eyes, bones, and skin. Symptoms include retinitis pigmentosa (group of genetic eye conditions characterised by night blindness and tunnel vision), nystagmus (involuntary movement of the eyes which is usually from side to side), anosmia (lack of sense of smell) and loss of muscle coordination. Wolman’s disease is a lipid storage disorder characterised by symptoms such as hepatomegaly, splenomegaly, steatorrhea (fecal matter is frothy, foul-smelling and floats due to a high fat content), abdominal distention and adrenal calcification that appears in the first weeks of life. It occurs due to the deficiency of lipase, an enzyme acid. This leads to the accumulation of lipids within the cells. Metabolic disorders are characterized by a number of symptoms including hypertension, resistance to insulin, cholesterol abnormalities, obesity, and the increased risk of blood clotting. Additionally, these illnesses are often thought of in the context of endocrine disorders such as diabetes mellitus. Genetic diseases known as metabolic myopathies affect muscles; patients frequently develop fatigue, muscle pain, and weaker than normal muscle tissue because of a lack of energy.
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There are many other metabolic disorders including Pompe’s disease, mucopolysaccharidoses, mitochondrial myopathies, Lesch-Nyhan syndrome, Farber’s disease, Barth syndrome and amyloidoses. SEE ALSO: Endocrine Diseases (General); Genetic Disor-
ders.
Bibliography. W.L. Nyhan, B.A. Barshop, and O.T.
Pinar, Atlas of Metabolic Diseases, 2nd ed. (Hodder Arnold, 2005).
Farhana Akter King’s College London
Methamphetamine Abuse The illicit use of methamphetamine has emerged in recent years as an important public health concern. The drug is a strongly addictive central nervous system stimulant that has shown widespread abuse globally. It is easy to synthesize from compounds that are readily available, inexpensive, over-the-counter ingredients. In the United States, methamphetamine is classified as a Drug Enforcement Agency (DEA) Schedule II drug, which means that it has high potential for abuse, but can be made available in some medically necessary circumstances. Prescriptions for methamphetamine are relatively rare, are nonrefillable, and require careful documentation. Special security is placed on storage of the drug, and quotas are placed on manufacturing. In many other nations, methamphetamine is not used medically at all and is only available for research purposes. Often, the maximum penalty for production and distribution is life imprisonment. The street form of methamphetamine that is of low purity is commonly known as “speed.” It is usually snorted nasally, pressed into a pill and ingested, or dissolved in water and injected intravenously. “Ice,” “crystal meth,” or “Tina” is purified methamphetamine and has a longer-lasting high. It is commonly smoked in a glass pipe or in aluminum foil heated by a flame underneath, a method known as “chasing the white dragon.” Like speed, it is also frequently injected intravenously.
1120 Methamphetamine Abuse Drug Effects The sensation acquired after using methamphetamine varies with the route of administration. Effects are felt most rapidly with injection, and more slowly with inhalation. Ingestion of pills provides the most delayed high. A “rush” of euphoria, an intensely pleasurable feeling attained soon after taking methamphetamine, is unique to injection and inhalation. Pharmacologically, methamphetamine acts by affecting the amount and effects of monoamine neurotransmitters, particularly norepinephrine, dopamine, and serotonin, in the central nervous system. The drug acts as a very potent stimulant, causing euphoria, enhancing alertness, improving attention, and increasing libido. It is also not uncommon for methamphetamine users to become violent while under the influence of the drug. “Coming down” off higher doses of the drug shows opposite effects, including fatigue, difficulty concentrating, and often, severe depression. A variety of physiological changes also occur. There are increases in heart rate, blood pressure, core temperature, and respiratory rate, and substantial constriction of blood vessels occurs. Side effects, often present at low doses but especially prominent at higher doses, include cardiac arrhythmia, hyperthermia, stomach cramping, trunk and limb muscle tremor, repetitive behavior, jaw clenching and teeth grinding, anxiety, aggression, paranoia, and insomnia. In rare cases, cardiac abnormalities and stroke can occur and are potentially fatal. Animal studies, most of which have involved rats, have shown that after recurrent methamphetamine usage, anatomic changes occur in the brain that compromise the integrity of dopamine and serotonin systems. These findings suggest that long-term use of the drug, or perhaps even single large administrations or binges, may produce lasting changes in central nervous system functioning. However, very few human studies have been performed, although those that do exist are consistent with the data obtained from animals. What is known is that although the single-dose effects of methamphetamine include enhanced concentration and memory and psychomotor performance, long-term use leads to global cognitive impairment in these same functions. Weight loss, erectile dysfunction, and rapid and severe tooth decay, a phenomenon
known as “meth mouth,” are other prominent side effects associated with chronic use. With time, psychological dependence can develop as a methamphetamine user experiences slow thinking and depression when not taking the drug, requiring him or her to use more methamphetamine to maintain previous levels of functioning. Research shows that after nine months or more of abstinence from the drug, modest recovery in cognitive functioning may occur. Production Methamphetamine is readily produced using common household products and over-the-counter medicines, most notably ephedrine or pseudoephedrine. These compounds, once easily obtained in large quantities by purchasing cough and cold remedies, have been the subject of new legislation that restricts their purchase in many jurisdictions. Although synthesizing methamphetamine is a relatively simple process, most methods of production involve flammable chemicals, such as phosphine gas. Significant morbidity and mortality has resulted from fires caused by inexperienced chemists working with such compounds in clandestine laboratories. Much of the methamphetamine supply in the United States originates from large-scale producers located in Mexico and California. However, there has been a surge of small-scale laboratories in recent years, particularly in the Midwest, that have become an important source of the drug. These operations have been found in such diverse locations as mobile homes and motel rooms, exposing the general public to the danger associated with methamphetamine production. In 2006, the United Nations Office on Drugs and Crime reported that global production of amphetamine-like stimulants, including methamphetamine, was estimated at 480 metric tons. This was higher value than calculated for the previous year, but was less than that for 2000, showing an overall decrease since the beginning of the 21st century. Nations in North America; Central America; western, central, and eastern Europe; and east and southeast Asia represent the most important contributors to the global methamphetamine market. In particular, the largest producers of methamphetamine worldwide are located in Burma, China, and the Philippines.
Societal and Global Impact Recent surveys have suggested that the rate of increase of methamphetamine use in North America is the fastest among illicit drugs. In 2002, 1.4 percent of people aged 15 to 64 used methamphetamine or another amphetamine-type stimulant. Whereas use of methamphetamine has stabilized in the west, it is an exploding epidemic in the Midwest and is just in its early stages in the east. The DEA reported that in 2001, 1,370 kg of methamphetamine were seized along the Mexico–U.S. border whereas this statistic was only 6.5 kg in 1992. Additionally, admissions to treatment centers for methamphetamine abuse in the United States increased more than fivefold from 1993 to 2003. Moreover, the number of hospitalizations resulting from burns and other complications of hazardous laboratory fires has increased substantially in recent years, leading to a substantial healthcare costs. The World Health Organization reported that more than 35 million people worldwide regularly abused methamphetamine in 1996, a prevalence second only to cannabis use. Approximately 60 percent of these users live in Asia. Among 15- to 64-year-olds, the highest prevalence of methamphetamine or amphetamine-type stimulant abuse is found in Thailand (5.6 percent in 2001). Australia, New Zealand, the Philippines, Honduras, Taiwan, and the Czech Republic show slightly lower but still alarming rates of abuse. Methamphetamine use is associated with a high risk of transmission of sexually transmitted diseases and blood-borne viruses. For many young users, the drug is used to party, because it provides a pleasurable feeling, promotes wakefulness, and enhances alertness. However, data show that these users are also more likely to simultaneously abuse other drug, engage in unprotected sexual intercourse, and have multiple sex partners. Sex while under the influence of methamphetamine has been described as compulsive and obsessive, and is marked by a lack of inhibition. These behaviors are often highlighted in the media as being common among homosexual men who use methamphetamine, but they also are exhibited frequently by heterosexual men and women who use the drug. Either way, these risky sexual activities place users and their partners at high risk of HIV transmission, a fact that remains an important concern for public health authorities.
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Also worrisome are the risks unique to intravenous injection of methamphetamine. Poorly dissolved additives present in street methamphetamine can travel through the blood stream, embolizing in the lungs, liver, kidneys, or brain, causing tissues in these organs to infarct or die. The veins of repeated injectors can become collapsed, causing the user to seek out other veins, sometimes including those of the neck. There is a high risk of infection associated with injection because sterile needles are not often available, and endocarditis (infection of the heart lining and valves), pneumonia, bone and joint infections, and abscesses of the skin and other organs can occur. Users who share needles with others can acquire and transmit blood-borne viruses such as HIV and the hepatitis viruses B and C, which can cause long-standing liver disease, cirrhosis, and ultimately, liver failure requiring transplantation. There are also other, less obvious implications for public health. Epidemiological data are emerging that show that methamphetamine users are more likely to have intentional self-inflicted injury, be involved in assault, and be victims of motor vehicle accidents while on the drug. When hospitalized, these patients have significantly longer hospital stays and higher healthcare charges. Victims of methamphetamine laboratory explosions often require greater fluid resuscitation than other burn victims, and when acutely intoxicated, can become violent and are therefore more difficult to treat. Methamphetamine exposure to the developing fetus during pregnancy is associated with decreased growth, an effect that is exacerbated by concurrent cigarette smoking and that may be associated with long-term effects on the child. Moreover, methamphetamine use among mothers of growing children is associated with poverty, chaotic lifestyles, childhood sexual abuse, and involvement in difficult or abusive relationships with male partners. Treatment Treatment for methamphetamine addiction remains an area of current study, and has involved mostly medical and cognitive behavioral approaches. Many of these have been based on models already in existence used for treatment cocaine abuse. Clinical trials continue to examine the utility of dextroamphetamine, an amphetamine class drug that can be used
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to substitute methamphetamine, antidepressants, and several second-generation atypical antipsychotic drugs as medical adjuncts in treating methamphetamine addiction. Pharmacological intervention, however, does not address the often complicated life circumstances that contribute to addiction. Cognitive behavioral therapy helps patients appreciate the circumstances that often lead them to use methamphetamine, and helps them safely avoid these situations or effectively cope with them. Counselors are also trained to help patients modify their attitudes and behaviors about drug use and to teach effective life skills. Family therapy, in which abuse is confronted by the entire family of an adolescent methamphetamine user, may also be employed. In the future, special psychosocial interventions will likely be geared toward the unique backgrounds of diverse methamphetamine users, such as mothers, gay and bisexual men, criminally institutionalized users, users living in rural areas, and minorities. The Center for Substance Abuse Treatment’s Tip #33: Treatment of Stimulant Abuse is an important handbook for clinicians working with recovering methamphetamine users. Other approaches include the “Twelve-Step” program, which has been successful for treating other forms of substance abuse, and the “Matrix Model,” a 16-week outpatient treatment approach for treating stimulant abuse. Studies examining these approaches and others are ongoing and have shown some positive short-term results, but have been inconclusive in the long term. In any case, epidemiologists and other public health officials in North America and worldwide are currently focusing on the methamphetamine epidemic in an attempt to better characterize patterns of addiction. Treatment of methamphetamine abuse and strategies aimed at mitigating the harms of drug use, such as the transmission of HIV and other blood-borne disease, will remain an important area of focus in the future. SEE ALSO: AIDS; Amphetamines; Club Drugs; Drug Abuse;
Hepatitis; Rehabilitation.
Bibliography. A.M. Barr, et al., “The Need for Speed:
An Update on Methamphetamine Addiction,” Journal of Psychiatry and Neuroscience (v.31/5, 2006); Center for Substance Abuse Treatment Tip #33 (Chair, CSAT Consensus Panel) (Department of Health and Human Services, 1998);
J. C. Maxwell, “Emerging Research on Methamphetamine,” Current Opinion in Psychiatry (v.18/3, 2005); R. Rawson, Treatment of Stimulant Abuse, NIDA Research Report— Methamphetamine Abuse and Addiction, http://www.drugabuse.gov/PDF/RRMetham.pdf (cited August 2006). Scott E. Hadland, M.D. Washington University School of Medicine
Methylation Methylation refers to the replacement of a molecule or atom by a methyl (-CH3) group. Various types of methylation are defined based upon the atom or molecule that is replaced. In genetics, methylation may refer to the silencing of one of the X chromosomes in females by adding a methyl groups to its cytosine bases by an enzyme called DNA methyltransferase. In biochemistry, methylation is the replacement of a hydrogen atom with a methyl group. Methylation reactions are usually catalyzed by enzymes. Methylation serves specific purpose in systems; for example, it may be used to modify the structure of heavy metals, regulate the expression of genes, regulate the function of proteins, and also regulate the metabolism of RNA. There are two basic types of methylation: chemical and biological methylation. Chemical methylation is studied in the area of organic chemistry, where the term alkylation is used to define the addition of a -CH3 group. Alkylation is done using electrophilic (electron loving) compounds such as dimethyl sulfate and iodomethane, which react in a nucleophilic substitution. For example, ethers may be produced by methylation of alkoxides, and ketones may be produced by methylation of ketone enolates. Biological methylation occurs in various ways. In epigenetic inheritance, methylation can occur as DNA methylation or protein methylation. In DNA methylation, there is an addition of a methyl group to a cytosine residue, causing cytosine to become 5-methylcytosine. DNA methylation occurs at CpG sites, that is, sites where a cytosine is immediately in front of a guanine. This type of methylation controls gene expression or activity. In protein methylation, a lysine amino acid or an arginine residue is methylat-
Mexico
ed in the reaction. Arginine may be methylated once or twice, and lysine may be methylated once, twice or three times. Histones can also be methylated by an enzyme called histone methyltransferase, which transfers methyl groups from S-adenosyl methionine to the histone. Protein methylation is also used to control gene expression by activating or deactivating a gene. Eukaryotic embryos also undergo methylation. Eukaryotic DNA is unmethylated from fertilization to 8-cell stage. It then undergoes de novo methylation from the 8-cell stage to morula, during which epigenetic information is modified and added to the genome. Methylation is complete by blastula stage. If embryonic methylation doesn’t occur, the embryo dies. Methylation continues to occur in the postnatal development and plays an important role in the interaction of gene expression and environmental factors. Methylation plays an important role in tumor formation. Tumors begin with abnormal localized hypermethylation, genome-wide hypomethylation, and increased expression of DNA methyltransferase. Research shows that genome-wide hypomethylation leads to increased mutation rates and instability of chromosomes. Furthermore, hypermethylation is one of the symptoms seen in prostate cancer. Bacteria also use methylation as a tool for self-defense. Bacteria protect its DNA by methylation of adenosine bases. Foreign DNA that enters the bacteria remains unmethylated, thus, prone to destruction by the bacteria’s restriction enzymes. ALSO SEE: Biochemistry; Chromosome; DNA; Genetics. Bibliography. Robert L. Nussbaum, Roderick R. Mc-
Innes, and Huntington F. Willard, Genetics in Medicine, 6th ed. (Thompson & Thompson, 2001). Rahul Gladwin, M.D. University of Health Sciences, Antigua
Mexico Prior to the arrival of the Spanish in 1519, the area of modern-day Mexico was occupied by the Aztecs and other peoples, who had established a highly de-
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veloped sense of healthcare. Although most of their medical works were lost, some medical tracts from the Aztec period survive, indicating great advances they had achieved. Indeed the Conquistadors were so interested in the medical treatments of the Aztecs that King Philip II of Spain in 1570 was encouraged to send his doctor Francisco Hernandex to Mexico for seven years to record much of the information that might otherwise have been lost. The arrival of the Spanish changed the whole healthcare system in the country. While most Indians continued to use herbal remedies, many succumbed to newly-introduced European diseases such as smallpox, cholera, typhoid, measles and influenza. The Spanish and other Europeans also suffered from new medical conditions such as venereal diseases and also from bites from poisonous snakes. The healthcare system established by the Spanish was solely aimed at the Europeans, with the majority of Mexicans unable to access it. It was also largely located in major cities such as Mexico City and Vera Cruz. This did not stop epidemics such as that of smallpox in 1797 or Asiatic cholera in 1833. Mexican independence was declared in 1810, and was recognized eleven years later, after which there was a series of wars which saw the United States take much territory from Mexico. Constant wars followed, with Emperor Maximilian ruling the country for three years, and then there were many presidents, some of whom had popular support. The Mexican Revolution of 1910 changed the political landscape, but instability still afflicted Mexico until the 1930s. After independence in 1810, there were attempts to improve the healthcare system of the country, with the Mexican National Academy of Medicine established in 1864. During the presidency of Benito Juarez (1867–1872), there were attempts to provide healthcare to more of the native Indian population of the country. Budgetary problems and fighting often prevented this, with great investment in the health services after the 1910 Mexican Revolution. Venustiano Carranza Garza, president of Mexico from 1914-1920, had been governor of Cohuila where he had improved many of the health facilities for the poor. He tried to do the same as president, but failed to introduce the muchneeded reforms. Some of his successors also tried, and failed, in the same endeavor.
1124 Micronesia, Federated States of The Mexican Association of Women Doctors was founded 1923, and the Franco-Mexican Medical Association, founded in 1928, with the Mexican Pediatrics Society, founded in 1930, the Mexican Society of Eugenics, founded in 1931, and the Mexican Academy of Surgery was established in 1933. In 1944, the Mexican Public Health Society was, founded, with many other associations founded over the next three decades: the Mexican National Cancer Institute (1946), the Mexican Association of Faculties and Schools of Medicine (1957), the Mexican Society of Nutrition and Endocrinology (1960), the Mexican Society of Parasitology (1960), the Mexican Federation of Gynecology and Obstetrics (1961), the Mexican Society of Cardiology (1964) and the Mexican Council of Dermatology (1974). The Republic of Mexico has a population of 107,784,000 (2006), with 186 doctors and 87 nurses per 100,000 people. Many diseases associated with lack of access to fresh drinking water and bad sanitation have been very common in Mexico. As a result, there have been many cases of cholera, dysentery, typhoid and also malaria, with many cases still existing in shanty towns and isolated rural areas. As these health problems have steadily become less important, during the twentieth century there has been a rise of other medical problems, especially cancer. An oncology hospital was established in Mexico City in the 1940s and the first cancer congress to be held in Mexico was at the School of Medicine of Guadalajara, Jalisco in October-November 1943. In 1964 the World Union Against Cancer held its conference in Mexico City. Another medical problem that has also become important in Mexico from the 1980s was obesity with Manuel Uribe (b. 1966), claimed, in 2006, to be the most obese human in the world, weighing 1235 lbs. The rise in the level of obesity in Mexico has also led to other problems such as higher rates of diabetes and cardio-vascular problems. SEE ALSO: Diabities; Disease and Poverty; Influenza; Obe-
sity; Smallpox; Typhoid.
BIBLIOGRAPHY. James B. Pick, Edgar W. Butler and Eliz-
abeth L, Lanzer, Atlas of Mexico (Westview Press, 1989); Gordon Schendel, Medicine in Mexico: from Aztec herbs to betatrons (University of Texas Press, 1968). Jake W. Spidle, Doctors of Medicine in New Mexico: A History of Health
and Medical Practice 1886–1986 (University of New Mexico, 1986). Justin Corfield Geelong Grammar School, Australia
Micronesia, Federated States of The Federated States of Micronesia are located in the Pacific Ocean, north of Papua New Guinea. This island nation is made up of four island groups, or states: Chuuk, Kosrae, Phonpei, and Yap. There are 607 islands in total, with a combined landmass of less than 700 kilometers. From end to end, the chain of island is spread across 1,800 miles of ocean. After World War II, these island groups became part of the U.S. Trust Territories. A constitution was adopted in 1979, and independence was formalized in 1986, although the Federated States maintain a close financial and administrative relationship with the United States. The population of the islands in 108,000. Micronesians are leaving the islands faster than they can be replaced by natural increase: the birth rate is 24.14 per 1,000, and the death rate just 4.66 per 1,000, but the migration rate is minus 21.02. Median age is 21.2 years. Life expectancy is 68.52 years for males and 72.28 years for females. Gross national income is $2,300 per capita, with 26 percent of residents living in poverty. Twothirds of islanders work in some form of government job, and most government money comes from U.S. aid. Remittances from Micronesians abroad are also a key part of the economy. There is little data on communicable disease in Micronesia. Sanitation is poor, with 61 percent of urban residents and 14 percent of rural residents using hygienic latrines. Waterborne and foodborne illnesses are the primary cause of hospital admissions; diarrhea and acute respiratory infections are very common. Leprosy and dengue fever are also present. Like many of the Pacific Islands, Micronesia has seen few HIV/ AIDS cases. Overall, Micronesians enjoy a good standard of health, at least as compared with other Pacific Islanders. Mortality stems primarily from heart disease, cancer and diabetes.
Microsurgery
Child mortality is low, with 34 death per 1,000 among infants and 42 deaths per 1,000 for children under five. Diarrhea and acute respiratory infections are the primary causes of death in the young. Immunization rates are high, and most children pass through their early life without incident. The islands have a small healthcare community, with a district hospital within each of the four states, 109 dispenseries, 6 primary care centers, 5 private clinics, and 1 private hospital. There are 62 physicians and 229 nurses throughout the islands, supplemented by a small group of allied health professionals. The government spends about $133 per capita on health each year. See also: Healthcare, Asia and Oceania. Bibliography. “Micronesia, Federated States of,” CIA
World Factbook, www.cia.gov (cited June 2007); UNAIDS: The Joint United Nations Programme on HIV/AIDS, “Micronesia (Federated States of ),” www.unaids.org (cited June 2007); UNICEF, “Micronesia (Federated States of )–Statistics,” www.unicef.org (cited June 2007); World Health Organization, “A Guide to Statistical Information at WHO,” www.who.int (cited June 2007); World Health Organization, “WHO Global InfoBase: InfoBase Home Page,” www. who.int/infobase (cited June 2007). Heather K. Michon Independent Scholar
Microsurgery Microsurgery can be defined as surgery on very small body structures, such as blood vessels and nerves, performed with the aid of a microscope and specialized instruments. The purpose of microsurgery is to allow the surgeon a clear and amplified visualization of the operating field. Since its inception into surgical practice in the mid-20th century, microsurgery has rapidly increased in practice and today is used in a wide variety of procedures. The first reported microsurgery occurred in 1960, when Jules Jacobson used a microscope in the process of repairing blood vessels. In 1964, Harry Bunke performed the first successful replantation, or reattach-
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ment, of an amputated body part, when he reattached a rabbit’s ear. Another important historical event in microsurgery occurred in 1968 when John Cobbett transplanted a human patient’s great toe to the patient’s hand where a thumb was missing, in effect transforming a toe into a finger. Since that time, microsurgery has pervaded many surgical specialties. Neurosurgeons use microsurgery to repair vascular defects such as aneurysms and arteriovenous malformations (AVMs), as well as to remove tumors from the brain and spinal cord. Plastic surgeons use microsurgery in many reconstructive techniques. Ophthalmologists remove cataracts, transplant corneas, and repair retinas with the aid of an operating microscope. General surgeons perform transanal endoscopic microsurgery in the treatment of rectal cancer. Other surgeons utilizing microsurgery include otolaryngologists, urologists, gynecologists, and orthopedists. The basic techniques in microsurgery include blood vessel repair, nerve repair, vein grafting, and nerve grafting. Blood vessel repair typically involves a procedure called anastomosis, or the connection of two separated blood vessels. Similarly, in nerve repair, two cut ends of a nerve are reconnected, also called nerve anastomosis or neurorrhaphy. Vein grafting is the process of transferring a segment of vein from another part of the body (typically the extremities, where there is an abundance of collateral circulation) to reconnect two ends of a severed vessel that would otherwise be under too much tension if they were reconnected to each other. Nerve grafting is performed for the same reason of tension reduction and often involves transfer of the sural nerve of the leg. These techniques allow for some of the more common procedures in microsurgery, namely replantation, transplantation, and free-tissue transfers. Free-tissue transfers, also known as flaps, are used to reconstruct tissues that are damaged beyond repair. Since microsurgery requires very specialized equipment, it is not as readily available in poorer nations compared to wealthier counterparts. Therefore, some international health groups are working toward increasing worldwide awareness of the possibilities of microsurgery. For example, one objective of the American International Health Alliance is to familiarize physicians at the global level with microsurgery and other techniques such as laparoscopy and echocardiography. There are also many national and international microsurgery organizations that encourage collaboration and
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sharing of knowledge. With continuing efforts such as these, hopefully more physicians and patients will be able to benefit from the advantages of microsurgery. SEE ALSO: Aneurysms; Cataract; Colorectal Cancer; Cor-
nea and Corneal Disease; Retinal Disorders.
Bibliography. Anthony J. Senagore, The Gale Encyclope-
dia of Surgery: A Guide for Patients and Caregivers (Thomson Gale, 2003); Robert A. Malt, The Practice of Surgery (Saunders, 1993); O.H. Wangensteen and S.D. Wangensteen, The Rise of Surgery. From Empiric Craft to Scientific Discipline (University of Minnesota Press, 1978). Khoi D. Than, M.D. Johns Hopkins University School of Medicine
Midwife A midwife is a person, generally a woman, who assisted a pregnant woman during and after the process of childbirth. The midwife has been an important part of society since prehistoric times, albeit with more or less efficacy according to place and time. In some societies in East Asia, for example, midwifery became associated with various shamanistic practices and the midwife therefore had additional duties related to celebration of the changing of the seasons and the placation of spirits. In general terms, as science and knowledge has progressed through time, midwives have become increasingly efficient in their ability to tend to women and children. However, death rates resulting from childbirth among poor and poorly educated societies can remain high and the medicine of developed countries can dramatically reduce these rates. In some cases, even in the twenty-first century, childbirth practices can have deleterious effects on the child or its mother and further expansion of education is required in such cases. State governments, non-governmental organizations including charities and the World Health Organization (WHO) of the United Nations work together to try to improve that level of education where required. This is not a problem confined to the developing world as there are many examples of abandonment or murder of babies imme-
A midwife is a person, generally a woman, who assists a pregnant woman during and after the process of childbirth.
diately after birth since the mothers involved are unable or unwilling to seek medical assistance, perhaps because of cultural or religious factors which should be set aside. From the beginning of the 20th century, most western European countries established official training schemes backed by legislation to ensure that qualified midwives were made available. The focus in developed countries moved from childbirth at home to childbirth in a hospital and, in the USA, this spurred the creation of qualified nurse-midwives, whose presence superseded traditional knowledge and practice in childbirth. Qualified midwives can also pass different types of qualification. Although the tendency towards professionalization has been followed in most parts of the world to some extent, many developing countries do not have the infrastructure to support large-scale hospitalization of pregnant women, even for a brief period and so midwives continue to assist in perhaps
Mine Safety and Health Administration (MSHA)
three quarters of all births around the world, whether they are qualified or not. Over the last couple of decades in some developed countries, a new trend has been to return childbirth to the home and downplay the high-technology aspects. Proponents of this approach believe that it not only reduces pressure on hospital resources but also provides a more natural and relaxing environment for mother and child, as well as any other family members in the house. Although medical advice is still required to determine whether complications are likely to arise and hence whether hospitalization is indicated, a woman and a single midwife giving birth is likely to be a continuing motif in family life in the future. The midwife might be assisted by other women close to the mother in some societies and, increasingly, by the father. Enormous improvements in hygiene and understanding resistance to disease make this a much safer prospect than in the past. The WHO now classifies as midwives all people who have successfully graduated from an officially designated training scheme within a particular country. Other people who follow customary practices are referred to as ‘traditional birthing assistants’ (TBAs) and, wherever possible, their role is restricted to non-clinical areas. For example, TBAs and other non-qualified people can be part of the social networking helpful in supporting an expectant mother and can take a role in ensuring that exclusive breastfeeding takes place within one hour of childbirth being completed, as well as ensuring the newborn baby is kept warm and dry to minimize risks of hypothermia. However, when it comes to the use of oxytocin or antibiotic prophylaxis for women undergoing caesarean section delivery, then only a qualified midwife or a doctor with midwifery training should be permitted to give the care. An intermediary position of health worker or nurse without specific midwifery skills also exists who is permitted to provide some types of health treatment under supervision which are prohibited from the TBAs entirely. The WHO explains the rationale behind this approach as follows: “The care providers designated for each intervention … are those who are best placed in terms of decision-making and who can provide the interventions most efficiently or cost-effectively, although it is acknowledged that other health providers may also be able to provide the interventions, or that others could do so if specifically trained and /or if supervised by a skilled attendant.” The
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range of competencies and skills required of a midwife will vary according to geography as different types and strains of disease or health risk wax and wane in importance. Awareness of the dangers posed by HIV/AIDS is of particular importance in many parts of the world. However, in those countries which are ethnically diverse, which are highly globalized and in which many people are entering and leaving, a broad range of skills and knowledge is more likely to be required together with access to a wide range of back up support in the case of the need for multiple forms of intervention. Since most of the developed world is moving towards this situation, it is clear that additional increases in the qualifications and abilities of medical staff will continuously be required. Of course, there are some occasions when people believe that cultural and traditional practices are preferable to modern medicine and so they withdraw or hide the mother from authorities so that the traditional practices take place. Such a practice may be viewed by those perpetrating it as an act of cultural resistance to a central state imposing unwanted policies; it is also common in some African countries where female genital mutilation is still practiced by some groups. See also: Obstetrics; Pregnancy; Prenatal Care. Bibliography. Constance Sinclair, A Midwife’s Handbook
(Saunders, 2003); World Health Organization, “Global Action for Skilled Attendants for Pregnant Women,” www.who. int/reproductive-health/publications/global_action_for_ skilled_attendants/mpr_global_action.pdf (cited July 2007). John Walsh Shinawatra University
Mine Safety and Health Administration (MSHA) The Mine Safety and Health Administration (MSHA) is the federal agency within the Department of Labor charged with regulating coal, metal, and nonmetal mining operations in the United States. Mining has always been one of the most hazardous occupations in the United States, and throughout the 19th and 20th centuries, it was not uncommon for more
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than 1,000 miners to die in any given year. In 1907, the most deadly year on record, more than 3,000 miners perished on the job. On March 9, 1978, Congress passed the Federal Mine Safety and Health Act of 1977. For the first time, coal, metal, and nonmetal mining operations were put under a single regulatory heading, and responsibility for that regulation moved from the Department of the Interior to the Department of Labor. The MSHA has two broad mandates: to regulate the mining industry and to protect worker health and safety on the job. The Mine Safety and Health Act of 1977 gave the agency broad authority to inspect mines and equipment and to levy fines for safety violations. In some cases, they can temporarily close down a mine until safety requirements are met. The MSHA can also recommend criminal charges be filed against mine owners and operators for flagrant safety violations. The MSHA has an active program to protect mine workers from both discrimination and dangerous working conditions; among other things, they operate a toll-free hot line for anonymous reports of safety violations or discriminatory behavior by mine owners. It works closely with state departments of mines to coordinate laws and regulations, and hold periodic training session and mock rescue drills to prepare for disasters. It also tries to educate the public on the dangers of entering abandoned mines through its “Stay Out-Stay Alive” program. The MSHA touts some impressive results in the vital statistics of mining during its tenure. Fatalities have dropped from a high of 242 in 1977 to 56 in 2003, and since 1995, the total number of fatalities have been below 100 a year. The number of mining disasters, defined by the MSHA as eight or more fatalities resulting from a single incident, have dropped from 12 during the 1970s to 9 in the 1980s, and down to 1 in the 1990s. On-the-job injuries resulting in lost hours have dropped 49 percent, from 5.81 lost-time injuries per 200,000 hours worked in 1977 to 2.95 lost-time injuries per 200,000 hours worked in 2005. And while the figures are incomplete, reported new cases of black lung (a serious respiratory disease caused by the inhalation of dust particles) have dropped 75 percent since the 1970s. Two incidents in the 2000s showed the best and the worst the MSHA had to offer. On July 24, 2002, nine miners became trapped in the Quecreek Mine in Somerset County, Pennsylvania, when they accidentally
breeched a wall and flooded the chamber. The MSHA and local rescue teams worked together and brought all nine safely to the surface after 77 hours below ground. However, the MSHA was criticized for its seemingly tepid response to the Sago Mine disaster in Sago, West Virginia, on January 2, 2006, where 12 of 13 miners died after an explosion. Critics maintain that the MSHA is chronically underfunded and behind the times on recommending technological improvements that could enhance mine safety. They charge that the agency has a myopic focus on individual accidents without looking at the big picture and question whether a single agency should be responsible for both regulation and inspection of an industry. Some favor the creation of a separate accident investigation division, citing the model of the National Transportation Safety Board, which is independent from the Federal Aviation Administration and other agencies that regulate the airline industry. See also: Occupational Health; Occupational Injuries;
Occupational Medicine.
Bibliography. “Mine Agency’s Dual Roles Draw Critics,”
USA Today (January 6, 2006); Alan R. Severson, ed., 25 Years of Success (U.S. Mine Safety and Health Administration, 2006). Heather K. Michon Independent Scholar
Mismatch Repair A mutational event that disrupts the superhelical structure of DNA has the potential to compromise the genetic stability of the entire cell. The DNA mismatch repair is a system whereby one can recognize and repair the erroneous insertion in the DNA sequence, correct the inappropriate deletion or the other problems that can arise during DNA replication and recombination. It can also help repair some types of DNA damage. The whole system is extremely complex which highlights the importance of evolution on DNA fidelity. There are two major ways of mismatch repairs: the long patch and the short patch. Long patch has the ability to repair all types of mismatches, although this
Moldova
is usually by replication, and it can also excise tracts, which are up to several kilobases long. By contrast, short patch covers only a specific mismatch, which can remove about 10 nucleotides repairing specific damage to the genome. However, the problems that can occur come from the fact that the mismatch repair is strand specific and that the newly synthesized strand may also include errors continued from parental strands, with researchers believing that further work might be able to make repairs easier and more effective. SEE ALSO: DNA; DNA Repair; Genetics. Bibliography. Errol C. Friedberg, et al., DNA Repair
and Mutagenesis, 2nd ed. (ASM Press, 1995); Anthony J. F. Griffiths, et al., Introduction to Genetic Analysis, 8th ed. (W. H. Freeman, 2000); R. Iyer, et al., “DNA Mismatch Repair: Functions and Mechanisms,” Chemical Review (v.106/2, 2006). Justin Corfield Geelong Grammar School
Missense Mutation A missense, or nonsynonymous, mutation is a type of point mutation affecting the coding region of a gene which alters a single base such that it codes for a different amino acid. The effects of such a change may be a profound change in phenotype, no perceptible change in phenotype, or some intermediate effect. When the effect of a missense mutation shows no significant phenotypic change, it is often termed neutral or quiet by analogy to so-called silent mutations where the point mutation does not alter the amino acid sequence of the encoded protein at all. Overall, missense mutations are reported to account for approximately half of the mutations causing genetic disorders in humans. Among diseases specifically affecting the metabolic activity of mitochondria, missense mutations are, by far, the most prevalent form of point mutation to mitochondrial DNA. The classic example of a missense mutation with profound effect is sickle cell disease where a change in a single base of the 17th codon of the beta-subunit chang-
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es one amino acid in the beta-subunit giving rise to the disease phenotype. However, a fuller understanding of the implications of missense mutations comes from the study of enzyme function. The X-linked hypoxanthine guanine phosphoribosyl transferase (HGPRT) gene is crucial for nucleic acid metabolism. Missense mutations to HGPRT create a variety of disease states depending on the exact location of the mutation and significance of the difference in amino acid caused by the mutation. The extent of residual enzyme activity in mutants correlates well with the clinical phenotype of affected males. Considerations in the interpretation of such mutations include whether the location of the mutation will alter a portion of the enzyme actively involved in chemical reactions and whether the new amino acid is sufficiently similar in both size and chemical properties to allow the resulting protein to conform to a functional shape. SEE ALSO: Genetic Disorders; Nonsense Mutation; Point
Mutation.
Bibliography. R.L. Nussbaum, et al., Thompson &
Thompson: Genetics in Medicine, 6th ed., revised reprint (Saunders, 2004). Riccardo Poli, A New Schema Theorem for Genetic Programming with One-Point Crossover and Point Mutation (School of Computer Science, University of Birmingham, 1997). Bimal P. Chaudhari Boston University
Moldova With a per capita income of only $1,900, Moldova is the poorest country in all of Europe and ranks 188th of 233 nations in world incomes. This lack of resources has placed the health of the population at great risk. Officials report unemployment at 8 percent, but a fourth of Moldova’s potential workforce is employed abroad. Around 40 percent of the workforce is engaged in the agricultural sector, which generates 21.3 percent of the Gross Domestic Product (GDP). Eighty percent of the population lives in poverty, and 22 percent subsists on less than $1 a day. Moldova ranks 36.2 on the
1130 Moldova Gini index of inequality. The richest 10 percent hold 30.7 percent of all wealth, and the bottom 10 percent survive on 2.2 percent. The Moldovan government is working with the World Bank and the International Monetary Fund to promote economic growth and reduce poverty. The United Nations Development Programme (UNDP) Human Development Reports rank Moldova 114th of 133 countries of quality-of-life issues. Moldova has suffered a healthcare crisis since achieving independence from the Soviet Union, and a lack of funding has resulted in loss of services and an increase in poor health. Current data on health in Moldova are not easily available, but 78 percent of the population admits to finding healthcare unaffordable. Six percent of Moldova’s total budget is allocated to health. Forty percent of healthcare funding originates from out-ofpocket expenses. Social security is financed through taxes on workers and employers. It covers the elderly, the disabled, and survivors. Maternity benefits are payable at 100 percent of average earnings from the 30th week of pregnancy, continuing for 126 days. Two additional weeks are covered for multiple births or for childbirth complications. Adoption benefits are available for 56 days after adoption takes place. Moldova’s population of 4,466,706 experiences a life expectancy of 65.65 years, with women outliving men an average of seven years. While literacy is widespread, there is a slight difference between the percentage of males (99.6 percent) and females (98.7 percent). Approximately 98 percent of children attend primary school, but school attendance drops to 75 percent at the secondary level. Some 28 percent of children between the ages of 5 and 14 are in the labor market. Only a third of the population regularly uses iodized salt. While 97 percent of urban residents have access to safe drinking water, only 88 percent of rural residents have such access. Improved sanitation is also less accessible to rural residents (52 percent) than to urban residents (86 percent). Women give birth at a rate of 1.85 children each. Of all women in the relevant age group, 62 percent use some method of birth control. Only 1 percent of all women gives birth outside the presence of skilled attendants, and 1 percent of women fails to receive prenatal care. The adjusted maternal mortality rate for Moldova is 36 deaths per 100,000 live births. Between 1990 and 2004, infant mortality fell from 30 deaths per 1,000 live births to 23 and under-5 mortality dropped from 40 deaths per 1,000 live births to 28.
Currently, infant mortality is recorded at 38.38 deaths per 1,000 live births, and Moldova has the 75th highest incidence of infant mortality in the world. Five percent of infants are underweight at birth, and 3 percent of children under the age of 5 are underweight. Ten percent of under-5s are moderately to severely stunted, and 3 percent experience wasting diseases. Over half of under-5s receive oral rehydration when necessary. In the poorest areas of Moldova, half the children are ill, and the children in orphanages are particularly vulnerable to disease. Large numbers of children are chronic carriers of hepatitis B. Therefore, 99 percent of all infants are immunized against the disease. From 1990 to 1993, Moldova’s immunization program came to a virtual standstill due to a serious lack of funding. The international community stepped in and now funds 85 percent of the program. Consequently, infant immunization rates are high: diphtheria, pertussis, and tetanus (DPT1), 99 percent; DPT3 and polio, 98 percent; and tuberculosis and measles, 96 percent. Pollution presents major hazards to health in Moldova. Ill-advised agricultural practices have contaminated soil and groundwater with agricultural chemicals such as DDT. Moldova has a 0.2 percent adult prevalence rate of HIV/AIDS. Some 5,500 people are living with the disease, which has proved fatal to less than 300. Incidences of polio and tuberculosis are rising. The major causes of death are circulatory system diseases, cancer, and digestive system diseases. Nearly half (46 percent) of males and nearly a fifth (18 percent) of female Moldovans smoke, and alcohol abuse is a national problem. SEE ALSO: Birth Rate; Healthcare, Europe. Bibliography. Dina Balabanova, et al., “Health Service
Utilization in the Former Soviet Union: Evidence from Eight Countries (Cross-Country Comparisons),” Health Services Research, (v.39/6p2, 2004); Central Intelligence Agency, “Moldova,” www.cia.gov (cited August 2007); Helen Fedor, Belarus and Moldova: Country Studies (Federal Research Division, Library of Congress, 1995); Martin A. Levin and Martin Shapiro, eds., Transatlantic Policymaking in an Age of Austerity: Diversity and Drift (Georgetown University Press, 2004); Laura MacLehoe, “Health Care Systems in Transition: Republic of Moldova,” www.euro.who.int/document/e81265.pdf (cited August 2007); Social Security Administration, “Moldova,”
Molds
www.ssa.gov/policy/docs/progdesc/ssptw/2006-2007/ europe/moldova.html (cited August 2007). Elizabeth R. Purdy, Ph.D. Independent Scholar
Molds Molds are a group of multicellular fungi, which like other fungi, survive by breaking down organic matter. They are composed of networks of filaments called hyphae and reproductive tissues called spores. Molds are a ubiquitous and necessary part of almost every environment and ecosystem and, therefore, exposure to molds or their spores is virtually unavoidable. Molds are known to cause a specific set of well-documented diseases in humans, which will be described below. Molds cause disease by way of three specific mechanisms: (1) by causing an allergic immune response; (2) by the toxic effects of certain mold by-products; and (3) by direct infection. This article will focus primarily on the noninfectious health effects of molds. Recently, molds have also been associated with a wide variety of diseases and disabilities resulting from allegedly contaminated indoor environments. While there is little objective evidence of these claims in the scientific or medical literature, this controversy remains a topic of heated discussion in the media and the courtroom. It has been estimated that 10 percent of the U.S. population has allergic (immunoglobulin E [IgE]) antibodies to common outdoor molds. This means that they have been exposed to and have reacted to mold antigens (allergy-causing particles). It is estimated that up to half of these individuals have experienced symptoms related to mold exposure during their lifetimes. The most common manifestations of mold allergy sensitivity are asthma and allergic rhinitis. The symptoms of asthma include shortness or breath and decreased exercise tolerance, whereas the symptoms of allergic rhinitis include sneezing, and stuffy, runny nose. The relationship between the severity of asthma, particularly in children, and outdoor mold is well established. Indoor molds have also been studied as a cause of worsening asthma symptoms, but here, the
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evidence is less convincing because damp and unclean indoor environments are likely to contain a variety of other allergens as well. Allergic rhinitis and dermatitis (a similar process of inflammation of the skin) have been shown to be related to mold allergens, but much less so than pollens, animal dander, and house dust mites. Severe immune reactions to molds can occur and may present as a syndrome called hypersensitivity pneumonitis. This condition is usually due to inhaling large quantities of mold or other foreign proteins as a result of occupational exposures. Two other syndromes, allergic bronchopulmonary aspergillosis (ABPA) and allergic fungal sinusitis (AFS) are very rare, and occur when individuals who are allergic to molds have fungi growing inside cavities in their lungs or sinuses. The role of molds in chronic sinusitis is controversial because molds are found in the nasal cavities of healthy individuals as well as those with chronic sinus problems. People with asthma or other allergic conditions should consider minimizing their exposure to indoor and outdoor irritants and allergens, including molds. Measurement of antibodies to molds is not routinely done and cannot establish a causative or temporal relationship with particular exposures. Mycotoxins Molds present in spoiled foods may elaborate toxins, which in high doses, can cause disease. Grains, peanut products, and wines are some of the more common foods that may be affected with molds producing aflatoxins and ocratoxins. True toxicity from these agents is rare outside of starvation settings where people may intentionally eat spoiled food. Certain molds can also harbor toxins in their spores and hyphae, which are produced when exposed to particular environmental conditions. These toxins must be inhaled to cause illness. They are usually very short acting and do not accumulate in tissues. Therefore, they are unlikely to cause adverse long-term health effects. In the occupational setting, mycotoxins may become aerosolized and cause toxic dust syndrome. The American College of Occupational and Environmental Medicine’s evidence-based statement on mycotoxin-mediated disease suggests that complaints of nonspecific illness related to home or office indoor air are unlikely to be associated with mycotoxins. The presence of certain molds known to elaborate toxins
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Molds
under specific conditions is not sufficient evidence of actual toxin production, aerosolization, nor grounds for attribution of vague symptoms. The specific symptoms and toxic dosages of mycotoxins are well known and the occurrence of nonspecific syndromes resulting from nonoccupational inhalation of mycotoxins is not supported by evidence. Mold-Related Irritation Certain compounds and particles produced by molds can produce irritation in human tissues. These chemicals cause transient inflammation at the site of tissue contact and their effects are related to the amount of irritant present, the length of exposure, and the sensitivity of the subject. Volatile organic compounds released from mold are responsible for their odor, but are usually present at such low levels, even in damp buildings, that they are not likely to cause airway irritation. Mold particles are not normally found in the air, but may be present if mold growth is violently disturbed. These particles, other than in high-risk occupational settings, are not likely to be present in sufficient quantities to cause disease. In the case of high-level exposure to volatile moldrelated compounds or particles, removing the source or removing the exposed patient from the source of the irritant should be sufficient to relieve symptoms. Other Potential Mold-Related Diseases It has been proposed that exposure to mold-related irritants or mycotoxins may cause immune dysfunction resulting in disease. However, several professional organizations have determined that there is no credible evidence of molds or mold products causing clinically significant immunodeficiency or autoimmunity. Infections Fungal infections range from mild skin infections to severe systemic disease. Molds of the malassezia genus are present as commensal organisms on most humans. Overgrowth of these organisms causes a condition called tinea versicolor, which presents as light-colored skin pigmentation. Other common molds found in the environment become a nuisance to healthy individuals when overgrowth occurs because of changes in the host mucosal barrier, normal bacterial flora, or other factors.
Several species of pathogenic molds infect humans when spores enter through the respiratory tract. Diseases such as histoplasmosis, blastomycosis, and coccidiomycosis may cause disease in healthy individuals who are exposed to high-risk environments. Other common molds, such as aspergillus, may infect immunocompromised hosts, but rarely cause disease in healthy people. Molds and Damp Indoor Environments There is little evidence that damp indoor environments increase the risk of infection from a mold species. Molds are much more common in the outdoor environment and this is where mold exposures that result in infection are more likely to occur. As mentioned above, numerous epidemiological studies of varying quality have suggested a relationship between damp indoor environments and worsening asthma, allergies, or other respiratory disease. Whether, or how much molds contribute to this finding is unclear. Given the current evidence, it is not possible to establish a cause-and-effect relationship or a mechanism of disease linking a particular syndrome with a specific etiological agent. Nonetheless, when typical clinical symptoms are present and molds are found, remediation should be carried out. This remediation should include removal of obvious mold and residue, and dehumidification of the environment according to the guidelines available from the Centers for Disease Control and Prevention or the U.S. Environmental Protection Agency among others. SEE ALSO: Allergy; Asthma; Environmental Health. Bibliography. R.K. Bush, et al., “The Medical Effects of
Mold Exposure,” Journal of Allergy and Clinical Immunology (v.117/2, 2006); R.K. Bush, et al., “The Medical Effects of Mold Exposure: Erratum,” Journal of Allergy and Clinical Immunology (v.117/6, 2006); B.D. Hardin, B.J. Kelman, and A. Saxon, “Adverse Human Health Effects Associated with Molds in the Indoor Environment,” Journal of Occupational and Environmental Medicine (v.45/5, 2003); L.J. Mazur, et al., “Spectrum of Noninfectious Health Effects from Molds,” Pediatrics (v.118/6, 2006). Barry Pakes, M.D. University of Toronto
Mongolia
Monaco Located on the Mediterranean Sea, Monaco attracts tourists from all over the world who come to visit the casinos. Other visitors are drawn to Monaco because it was the home of actress Grace Kelly who married into the ruling Grimaldi family in 1956 or to see the celebrities who regularly visit the area. The per capita income of $27,000 earns Monaco the title of the 35th richest nation in the world. Business taxes are low, and there is no income tax at all. Consequently, Monaco has become a tax haven for the wealthy. Around 17 percent of the population continue to labor in the agricultural sector, and 22 percent of the labor force is unemployed. While the United Nations Development Programme (UNDP) does not currently rank Monaco because of missing data, the standard of living is relatively high and is comparable to other French metropolitan areas. However, the quality of healthcare in Monaco varies according to the ability to pay for services. As a result, those who live in poverty are more likely to suffer from conditions that are affected by living conditions and lifestyle. The government spends 9.7 percent of the total budget on healthcare, allocating $4,487 per capita for health programs. Nearly 76 percent of all healthcare funding originates from the government, and 98.6 percent of those funds are directed toward Social Security. The private sector accounts for 24.1 percent of total health funding. Of that amount, 85.30 percent evolves from out-of-pocket expenses. There are 5.81 physicians, 14.19 nurses, 0.31 midwives, 1.06 dentists, and 1.91 pharmacists per 1,000 population in Monaco. The Social Security program insures most workers, and separate systems have been established to insure the self-employed, civil servants, and hospital and utility workers. Social security is financed through mandatory employee (6.15 percent of gross earnings) and employer (23.66 percent of gross payroll) contributions. Beneficiaries are the elderly, the disabled, and survivors. New mothers receive cash benefits if they meet eligibility requirements based on length of employment. Monaco is small, covering an area of only 1.95 km2. The population of 32,543 people enjoys a life expectancy of 79.69 years. Women outlive men an average of eight years. Literacy is virtually universal at 99 per-
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cent. Most children attend primary school regularly. At the secondary level, females (71 percent) attend at a considerably higher rate than males (59 percent). The entire population has access to safe drinking water and improved sanitation. Monegasque women give birth at a rate of 1.76 children each. Between 1990 and 2004, infant mortality dropped from 7 to 4 deaths per 1,000 live births, and under5 mortality decreased from 9 to 5 deaths per 1,000 live births. At present, the infant mortality rate is 5.35 deaths per 1,000 live births. Newborns are particularly susceptible to pneumonia, meningitis, sepsis/septicemia, and various infectious diseases. Only 1 percent of Monegasque children are not immunized against diphtheria, pertussis, and tetanus (DPT1 and DPT3), polio, hepatitis B, and measles. Ten percent are not immunized against tuberculosis. The leading causes of death in Monaco are ishemic heart disease; cerebrovascular disease; trachea, bronchus, and lung cancers; colon and rectum cancer; chronic obstructive pulmonary disease; endocrine disorders; falls; and diabetes. Information on the incidence of HIV/AIDS in Monaco is unavailable. SEE ALSO: Birth Rate; Healthcare, Europe. Bibliography. Central Intelligence Agency, “Monaco,” www.cia.gov/cia (cited Spencer Di Scala, Twentieth Century Europe: Politics, Society, Culture (McGraw-Hill, 2004); Sandra Halperin, War and Social Change in Modern Europe: The Great Transformation Revisited (Cambridge University Press, 2004); Martin A. Levin and Martin Shapiro, eds., Transatlantic Policymaking in an Age of Austerity: Diversity and Drift (Georgetown University Press, 2004). Elizabeth R. Purdy, Ph.D. Independent Scholar
Mongolia Mongolia is a landlocked country in eastern Asia, between China and Russia. It is the least densely populated country in the world, with 4.4 people per mile. The center of the powerful Mongol Empire in the 13th Century, for many centuries it passed between Russian
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Monozygotic Twins
and Chinese rule, emerging in the 20th century as a Communist country firmly allied with Russia. In 1992, the country ratified a new, democratic constitution. The population is 2,900,000 and growing at 1.49 percent annually. The birth rate is 21.07 per 1,000 and the death rate is 6.21 per 1,000. The median age is 24.6 years. Life expectancy is 64.61 years for males and 69.48 years for females. Gross national income is $690 per person, with 27 percent of the population living on less than $1 day. The economy has traditionally been based on nomadic herding and agriculture, and is only now beginning to develop some of its natural resource sector. A severe drought in 2000-2001 lead to a serious loss of livestock and crops. Clean water and sanitation is a problem throughout the country, with less than 40 percent of the rural population able to access safe water and hygienic latrines. Conditions are slightly better in the urban areas, where 87 percent have safe water and 75 percent have sanitation. Common communicable diseases included hepatitis A, B and C, typhoid fever, meningitis, diarrhea, and acute respiratory infections. There have been only a small number of HIV/AIDS cases reported in Mongolia over the past decade. However, the World Health Organization warns that the country is primed for a major outbreak: almost half the population is under the age of 23 and an increasing number of young people are moving to urban areas. STDs are already on the increases, and the tuberculosis rate is high. The TB prevalence rate is 209 per 100,000, with a cure rate of 87 percent. The disease burden is rapidly shifting to non-communicable diseases, and “lifestyle” issues. Rates of cardiovascular disease, cancers, accidents and poisoning have all climbed in recent years. Injuries and accidents, many of them fueled by alcohol consumption, is the third leading cause of death. Rates of obesity and diabetes is low, but tobacco use is high among men. Drug abuse and accidental overdoses, both accidental and intentional, has emerged as a serious problem in urban areas. Mongolia is, as UNICEF says, a country of children, with 32 percent of the population under the age of 14. Overall health has been improving for many years, with low mortality rates of 22 infant deaths and 28 under-five deaths per 1,000. Nutrition rates, once very poor, are now much better, with low rates of underweight and stunted children.
Children do still suffer from poor water quality and limited sanitation. Among older children, teenage pregnancy rates have declined, but sexually-transmitted diseases are climbing, and is now the leading communicable disease for between 36-42 percent of Mongolians under 25. Contraception use among women is close to 70 percent, and the fertility rate is relatively low at 2.25 children per woman. Ninety-four percent of women receive prenatal care, and 97 percent of births are attended by trained professionals. Despite this level of care, the country still has a fairly high maternal mortality rate of 110 deaths per 100,000 live births. With a population spread out across a huge geographical area, few urban centers, and difficult travel to the more isolated regions, the government has been challenged to provide healthcare services to all Mongolians. There are 34 general and 17 specialized hospitals in Mongolia, along with 577 private clinics and 230 heath centers. Care is concentrated in the cities, primarily the capital at Ulaanbaatar. There is a large pool of medical personnel, including 6,590 physicians, 5,166 of whom are female. See Also: Birth Rate; Healthcare, Asia. Bibliography. “Mongolia,” CIA World Factbook, www.
cia.gov (cited June 2007); UNAIDS: The Joint United Nations Programme on HIV/AIDS, “Mongolia,” www.unaids. org/en/Regions_Countries/Countries/mongolia.asp (cited June 27, 2007); UNICEF, “Mongolia—Statistics,” www. unicef.org (cited June 2007); UNICEF, “Multiple Indicator Cluster Survey, Mongolia, 2005–2006 Key Findings,” www. unicef.org (cited June 2007). Heather K. Michon Independent Scholar
Monozygotic Twins Monozygotic twins (MZ), often referred to as identical twins, are not simply twins who are similar in appearance. More specifically, the term relates to the biological relationship of the pair of siblings. MZ twinning occurs after the normal fertilization of one egg by a sperm that ultimately forms one zygote. Whereas during a typical
Monozygotic Twins
single childbirth the zygote continues to develop into one fetus, in this case, the zygote splits into two within the first 14 days of development, and continues to develop into two genetically identical twins. It is also possible for twins to remain partially conjoined, a result of improper separation, but this event is much more rare than that of separated twins (1 in every 200 twin pairs is conjoined). MZ twins may then share one placenta, referred to as monochorionic twins, or may have their own separate placentas, referred to as dichorionic twins. Timing of separation is the distinguishing factor in this case, as dichorionic twins separate within the first four days after fertilization. With the ever-improving healthcare systems, twin pregnancies often have positive health outcomes. However, the age-old concerns of preterm delivery and low birth weight, and complications associated with a greater risk of morbidity and mortality compared to those of singleton births still exist. Thus, healthcare providers are motivated to take proper precautions and care when supporting twin pregnancies so as to prevent adverse outcomes for the mother and/or the twins. Such precautions include the ability to perform emergency Caesarean section, and to provide fetal heart monitoring, ultrasound, and intensive care support. Above all, it is necessary to ensure that the mother is adequately advised of the possibility of adverse events or complications. Normal vaginal delivery, Caesarean, or mixed methods are possible methods of delivery. Caesarean section, however, is often necessary in the event of malpositioned twins, cord entanglement, or twin-to-twin transfusion syndrome in which the fetuses share one placenta and its associated blood vessels resulting in disproportionate allotment of necessary nutrients. Because the MZ twins share the same genes, the twins will always be the same sex and tend to develop similarly in appearance, as well as in other physical and mental features. This process is quite distinct from that which occurs with dizygotic twins (fraternal twins) where twins may or may not be of different sexes with or without similar physical appearances. Development after birth, however, also relies on environmental factors and thus MZ twins may grow to become individuals who do not appear to be exactly “identical” in appearance and personality. Thus, questions of the relationships between environment and
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genetics in health, psychology, and development have led many researchers to conduct “twin studies” for clarification. The sociological relationship of twins may also vary from being extremely close and dependent, to complete indifference. Often, parents and professionals note characteristic twin behaviors and some suggest the existence of idioglossia, twin language, although it is debated whether this language may actually be the result of delayed language development. Contrary to popular belief, families are not genetically susceptible to having MZ twins. Researchers assert that MZ twin pregnancies occur only by chance, despite the recent increase in incidence of twin pregnancies. Recent estimates from the United States suggest the chance of having a MZ twin pregnancy is 3 in every 100 pregnancies. The odds of twin pregnancy also increase as the age of the mother increases, and it is estimated that women over the age of 50 years have a one in nine chance of experiencing a twin pregnancy. Modern fertilization techniques have also been associated with recent increasing trends of twinning and multiple-birth pregnancies. However, patterns and trends in twin pregnancies, as well as those of multiple pregnancies, have been found to vary by country and race with little understanding of the etiology of these discrepancies. SEE ALSO: Dizygotic Twin; Pregnancy; Premature Babies;
Prenatal Care.
Bibliography. B. Dodd and S. McEvoy, “Twin Language
or Phonological Disorder,” Journal of Child Language (v.21/2, 1994); The Center for the Study of Multiple Births, http://www.multiplebirth.com (cited October 2006); Pamela Fierro, “Parenting of Twins,” http://multiples.about. com/od/pregnancy/ (cited October 2006); Louis G. Keith, et al., “Chapter 81: Multiple Gestation: Antenatal Care,” in Gynecology and Obstetrics (Lippincott-Raven, 1997); Louis G. Keith, José A. López-Zeno, and Timothy Johnson, “Chapter 82: Multiple Gestation: Labor and Delivery,” in Gynecology and Obstetrics (Lippincott-Raven, 1997); National Center for Health Statistics, “Final Natality Data,” www.marchofdimes.com/peristats (cited October 2006). Andrea L. Wirtz Johns Hopkins University School of Public Health
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Morocco
Morocco This kingdom in North Africa was ruled by the Moors in medieval times, with the Portuguese capturing and then holding some port cities along the coast during the fifteenth century. These were later placed under Spanish rule (when the kingdoms of Spain and Portugal had the same ruler). By the 1900s the Spanish and French had occupied different parts of Morocco—the Spanish holding the northeastern part around Tetuan, and the region later known as the Spanish Sahara. In addition the Spanish held the port cities of Ceuta and Melilla, which remain a part of Spain, and also the port of Ifni. The French occupied the remainder of the country, except for Tangier which became an international city. In 1956 the kingdom of Morocco gained its independence, taking over Ifni in 1969, and the Spanish Sahara when the Spanish left during the 1970s. Morocco has a population of 33,241,000 (2005), with 46 doctors and 105 nurses per 100,000 people. During medieval times, Arab surgeons made heavy use the works of Avicenna (980-1037), whose work influenced much medical teaching in North Africa and the Middle East. The arrival of the colonial powers, led to a European-style medical system with most hospitals transformed to treat Europeans and also wealthy locals, especially Jews and members of the local elite. The Pasteur Institute was established in Casablanca in 1912, and the National Institute of Hygiene was founded in 1930 with it now running the National Poison Control Center and the Toxicological Documentation Center. After independence, the new Kingdom of Morocco increased the revenue spent on healthcare, with many new hospitals being built and the existing ones being modernized and enlarged. Gradually the Social Welfare Fund was established with all Moroccans contributing to a national insurance program for sickness and accidents. To encourage people to move to the Western Sahara, the Moroccan government has built many hospitals and clinics, and made healthcare there free for all. Most of the health problems which Morocco faced when it became independent were from the poor sanitation and lack of access to clean drinking water. The result was that many people suffered from cholera, typhoid, tuberculosis and dysentery. Tap water is now
safe in Morocco north of Marrakech, but in some isolated areas, where fresh water is not available, there are still problems with worms causing Bilharzia still being found in some ponds near the Atlas Mountains. Traditional medicines were mainly herbal, and some of these have been found to be effective and are still prescribed in many parts of rural Morocco. As healthcare has improved, and more people are living longer, there has been a higher prevalence of cancer. The story of a woman suffering from breast cancer was told by author Leila Lahlous in her book Do Not Forget God (1987), with the VenezuelanAmerican immunologist Baruj Benacerraf (b. 1920), son of Sephardic Jews from Morocco, winning the 1980 Nobel Prize in Physiology or Medicine for his work on cancer. The Center for Epidemiology and the Fight against Illness was founded in 1990. SEE ALSO: Breast Cancer; Cholera; Healthcare, Africa. BIBLIOGRAPHY. J. Bakker, “The Rise of Female Healers in
the Middle Atlas, Morocco,” Social Science and Medicine (v.35/6, 1992); Jamal Bellakhdar, “A New Look at Traditional Medicine in Morocco,” World Health Forum (v.10/2, 1989). Justin Corfield Geelong Grammar School, Australia
Mortality From a public health perspective, mortality is the measure of death in a population. The most general of these measurements is the crude mortality rate, which measures the number of deaths in a population over a specified period regardless of age or cause. Results of this measure are usually reported per a multiple of 10. In order to correct for population fluctuations, a midyear estimate of population size is usually used for this measure. To better account for differences in populations, however, adjusted mortality rates are more commonly reported. Age-adjusted mortality rate, which takes into account the difference between two populations’ age distribution, is the more commonly reported figure if it is possible to obtain.
Cause-specific mortality, gender-specific mortality, and age-specific mortality are other common measures that as the names imply, measure the number of deaths that occur within a specific category. For most of human history and across all continents, life expectancy beyond the age of 40 was not very promising. If individuals survived a childhood where they were exposed to infectious diseases, possible food shortages, and incurable congenital birth defects, these same individuals would enter an adulthood filled with an equal amount of adversity. Pregnancy, war, pestilence, and lethal dangers in occupations posed constant risks to an individual’s survival. Main causes of mortality now differ across the globe. Although many different interventions have played a role in altering human mortality, such as advances in pharmacotherapeutic and surgical treatments, two public health interventions—vaccines and sanitation practices—have provided some of the greatest impact on this change. In countries with more developed economies and established social, health, and sanitation infrastructure, infectious diseases have lost the impact on mortality which persists in countries and regions where there is less sanitation and overall economic development. In 1900, the number of deaths attributed to infectious diseases was nearly equal to those attributed to noninfectious causes. Except for the sharp peak during the influenza pandemic of 1918, the first half of the century witnessed a steep decline in the rate of death due to infectious diseases, which coincided with the initiation of wide-spread vaccination and sanitation programs. After 1950, the crude all-cause mortality line and noninfectious disease mortality line nearly overlap, demonstrating that in the latter half of the 20th century, the majority of deaths were due to noninfectious causes and inversely, only a small fraction of the deaths could be attributed to infectious diseases. Such an observation is an example of the success of these two public health initiatives in eliminating the risk of death due to infectious diseases and a possible framework to be used in regions where death due to infectious diseases still persists. SEE ALSO: Death and Dying; Death Rate. Bibliography. G.L. Armstrong, L. A. Conn, and R.W.
Pinner, “Trends in Infectious Disease Mortality in the Unit-
Moscati, St. Joseph
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ed States during the 20th Century,” Journal of the American Medical Association (v.281, 1999); M. L. Lindegren, ed., “Morbidity and Mortality Weekly Report,” www.cdc.gov/ mmwr (cited August 2007); World Health Organization, www.who.int (cited August 2007). Jose Lozada Independent Scholar
Moscati, St. Joseph (1880–1927) Giuseppe (Joseph) Moscati was born in Benevento in southern Italy on July 25, 1880. He was the seventh of nine children born to Francesco Moscati and Rosa de Luca, the Marquise of Roseto, and his was a wealthy family. Moscati was the first physician in modern times to be canonized by the Catholic Church. He worked at the Hospital of the Incurables in Naples; served in the medical unit in the front lines during World War I; taught as a professor of medicine at Naples University; and treated the poor who were often unable to obtain quality medical care. After finishing high school, Moscati attended the Vittorio Emanuele Institute from 1889 until 1890 before starting to study medicine at the University of Naples in 1897. He received his medical degree in 1903. From 1903 until 1908, Moscati served as a temporary assistant at the Hospital of the Incurables, promoted to assistant at the Physiological Chemistry Institute in 1908. It is said that on April 8, 1906, Moscati was able to evacuate all the residents at a home for the aged, sick, and paralyzed before Mt. Vesuvius erupted. In 1911, he worked to control and potentially eradicate cholera, a disease that left many in Naples vulnerable when ill sailors came to port. Moscati also became well known as a forensic surgeon, working at the Pathological Anatomy Institute. During World War I, the Hospital of the Incurables became militarized. During those years, Moscati treated thousands of soldiers. Moscati began each day with Mass and prayer, believing this gave him the strength to carry on the day’s work. He also believed that faith was a combination of prayer and action.
1138 Mosquito Bites Moscati died of a stroke on April 12, 1927. He was canonized by Pope John Paul II on October 25, 1987, the only layperson chosen at this time. The two miracles attributed to Moscati include the healing of Costantino Narraro from Addison’s disease; Narraro was said to have seen Moscati in a dream after his family prayed to the doctor; when he awoke, Narraro was cured. The second miracle involved Raffaele Perrotta’s recovery from spinal meningitis. SEE ALSO: Addison’s Disease; Cholera; Meningitis. Bibliography. “Saint Joseph Moscati,” Jesuits of Naples,
Italy, www.gesuiti.it/moscati/English/En_Bio1.html (cited August 2007); “St. Joseph Moscati: The Fruit of Daily Commitment,” Word among Us, www.findarticles.com (cited August 2007).
Kelly Boyer Sagert Independent Scholar
Mosquito Bites Is the resulting injury from a mosquito sting, which could produces from a local inflammatory reaction to, after an incubation period, a vector-borne disease, such as malaria, dengue, leishmaniasis, and yellow fever, among others. The mosquito bites its victims (humans or animals) because it is a hemophagus insect (use blood for feed and for its reproductive cycle). Their ability to bite is given by the prosbocis (an extended mouth structure). In the female mosquitoes, the piercing mouthparts allow them to draw blood into their alimentary tract. Many substances that make them able to bite practically being few or none perceived by the victim (anesthetics) and substances that make efficient the extraction of blood (anticoagulants) are secreted from salivary glands of the mosquitoes. Mosquitoes that transmit disease-causing pathogens (parasites, viruses, or bacteria) belong taxonomically to the suborder Nematocera (order Diptera), and particularly to the family Culicidae. In this family are located the two most medically important mosquito subfamilies: Anophelinae and Culicinae. The species of Anopheles (Anopheles gambiae, darlingi, dirius, and funestus, among others) belong to
the first one, being the vector of the most worldwide important parasitic disease, malaria. The species of Aedes (mainly Aedes aegypti, africanus, simpsoni, and albopictus) and Culex (Culex pipiens, sitiens, quinquefasciatus, univittatus, and restuans, among others) belong to the second one, being the vectors of dengue and yellow fever, and of other viral and parasitic diseases such as viral encephalitis (such as Venezuelan and Western equine encephalitis, Japanese encephalitis, and St. Louis encephalitis), West Nile virus, and filariasis, among others, respectively. In the case of yellow fever, the mosquitoes Haemagogus and Sabethes (also subfamily Culicinae members) are the most important vectors in the sylvatic cycle of disease. The risk associated with mosquito bites could be assessed in different ways; but derived from the study of malaria transmission, the entomological inoculation rate describes the number of infecting bites that a person received per night (but can be calculated in other time scales). To properly perform and analyze this, medical entomologists conduct entomological surveillance studies, using different methods of catching anopheline mosquitoes, such as human landing catches, light traps, a double net, a calf-baited trap, and collection of resting mosquitoes on vegetation, among others. These studies allow to public health authorities to perform a guided-vectorial control to reduce transmission of malaria and other vectorborne diseases in the areas where these diseases are prevalent or endemic. Other families in which its members could lead to a disease as a result of mosquito bites include the sand flies (family Psychodidae, subfamily Phlebotominae), the family Simulidae, and the family Ceratopogonidae. Leishmaniasis, bartonellosis, and papatasi fever, among others, are diseases transmitted by sand fly bites (Phlebotomus, Sergentomyia, and Lutzomyia). River blindness is a parasitic disease (produced by a filarial called Onchocerca volvulus) that is transmitted by a mosquito bite by species of Simulium (family Simulidae). Similarly, other filarial parasites, species of Mansonella, are transmitted by mosquitoes of the family Ceratopogonidae: Culicoides, Forcipomyia, Austroconops, and Leptoconops. In any case, thinking of a local inflammatory reaction to an important mosquito-transmitted disease, the exposure to mosquito bites should be avoided.
Mouth Disorders
Personal protection against mosquito bites is based on the use of topical repellents, the use of long clothing to reduce exposed skin, and the use of insecticide sprays, vaporizers, and nets, among others. Up to now, insecticides have remained the main tool for both killing mosquitoes and controlling mosquitoborne diseases. Although other vector-control strategies today should be considered, such as use of biological vector control (using other insects or microorganisms), a combination of those strategies in a balanced way, in what is called integrated vectorial control, should be considered to prevent mosquito bites and mosquito-borne diseases. In the past 10 years, an important ecological approach has been introduced in this management, with the integration of the ecoepidemiology, which considers the environmental aspects in the dynamics of transmission and the impact on the epidemiology of disease.
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Mouth Disorders
tive measures include seeking proper prenatal care, for appropriate nutrition and health management. Prognosis is good with comprehensive therapy (surgical repair, orthodontics, prosthodontics, speech therapy), beginning in early childhood and through to adulthood. Tongue inflammation with a red-surfaced tongue (glossitis) is sometimes associated with burning and pain of the tongue (glossodynia). Both appear to be benign and often secondary to other illnesses, medications, and smoking. Symptoms may cease with medication and smoking cessation. Oral lichen planus is a chronic autoimmune disease causing inflammation, and has similar symptoms to other mouth disorders. Therapy is aimed at managing pain and discomfort using local or systemic steroids. Chronic inflammation of the salivary gland with enlargement of the parotid glands may be due to a variety of disorders—Sjogren’s and sarcoidosis, diabetes, alcoholism and vitamin deficiencies—or as a side effect of drugs stimulating salivary flow and more viscous saliva. Sialolithiasis is calculus formation occurring most often in Wharton’s duct (draining the submandibular), and occasionally in Stensen’s duct (draining parotid glands), causing pain after eating and local swelling. The obstruction may be removed, or in severe cases, excision of the gland may be necessary. Leukoplakia is a white lesion that cannot be removed by rubbing (most often it is benign), and is often caused by irritation. Erythroplakia is similar to leukoplakia but presents with redness. In many cases erythoplakia is dysplasia or carcinoma. Squamous cell carcinoma of the oral mucosa accounts for the majority of oral cancers. Early detection is essential; lesions at 2 mm depth or less have the best prognosis. Treatment is by surgical excision, larger tumors require both excision and irradiation. Major risk factors include alcohol and tobacco use. Salivary gland tumors occur most often in the parotid glands and tend to be benign; tumors in the submandibular gland are less likely to be benign. Surgical excision if needed is sufficient treatment for most salivary gland tumors; post-surgical irradiation is indicated for large or high-grade tumors.
Mouth disorders are illnesses, infections, obstructions, and chronic conditions, related to the oral cavity. A cleft palate is a congenital malformation causing an incomplete closure of the lip and palate. This results in functional (eating, speech) and cosmetic issues. Preven-
Infections Candidiasis, also called oral thrush, is caused by the fungus candida albicans. Symptoms include pain and easily-removed, creamy-white patches over reddened mucosa. Antifungal therapy is used to treat candidiasis.
SEE ALSO: Flea Bites; Medical Entomology; Parasitic Dis-
eases; Tick Bites; Travel Medicine; West Nile Virus.
Bibliography. Antonio Atias, Medical Parasitology
(Mediterraneo, 2005); Rocio Cardenas, “Impact of Climate Variability in the Occurrence of Leishmaniasis in Northeastern Colombia,” American Journal of Tropical Medicine & Hygiene (v.75/2, 2006); Gordon Cook and Alimuddin Zulma, Manson’s Tropical Diseases (Saunders, 2003); Peter Davies, The American Heritage Dictionary of the English Language (Dell, 1977); David Feliciano, Trauma (Appleton & Lange, 1996); Yasmin Rubio-Palis and Christopher Curtis, “Evaluation of Different Methods of Catching Anopheline Mosquitoes in Western Venezuela,” Journal of the American Mosquito Control Association (v.8/3, 1992). Alfonso J. Rodriguez-Morales, M.D. Universidad de Los Andes Carlos Franco-Paredes, M.D. Emory University
1140 Movement Disorders Necrotizing ulcerative gingivitis (trench mouth or Vincent’s infection) is caused by an infection of both spirochetes and fusiform bacilli, with symptoms including painful gingival inflammation accompanied by bleeding, halitosis, fever and swollen lymph glands. Treatments include warm peroxide rinses, antibiotics, and gingival curettage for severe cases. Aphthous Ulcer (canker sore, ulcerative stomatitis) consists of single or multiple painful ulcers with yellow-gray fibrinoid centers, surrounded by a red halo, with healing in one to three weeks. The cause is not determined and treatment for symptoms include topical steroids and mouthwashes. Herpetic stomatitis presents with symptoms of initial burning, small vesicle rupture and scab formation. These are common, mild and last a short time, except in immuno-compromised individuals. Treatment with acyclovir may shorten the duration and reduce pain. Sialdenitis is a bacterial infection affecting the parotid or submandibular salivary glands. Symptoms include swelling of the gland with increased pain after eating, and tenderness and redness of the duct opening. The common organism cause is S. aureus and the infection often occurs secondary to dehydration, infection or illness. Treatment is with IV antibiotics and measures to increase salivary flow (hydration, warm compresses, and massaging the gland. see also: Cancers (General); Oral Surgeon. Bibliography. Rebecca W. Smith and Faculty of the Co-
lumbia Universtiy School of Dental and Oral Surgery, Columbia University School of Dental and Oral Surgery Guide to Family Dental Care (W.W. Norton & Co, 1997); Robert K. Jackler, MD and Michael J. Kaplan MD, “Ear, Nose & Throat” Current Medical Diagnosis and Treatment (Lange Medical Books, 2004); Lyn Michaud Independent Scholar
Movement Disorders Movement disorders are neurological conditions that affect the speed, fluency, quality, and ease of movement. Movement disorders occur as a result of damage or dis-
ease in a region located at the base of the brain (basal ganglia). The basal ganglia is comprised of clusters of nerve cells (neurons) that send and receive electrical signals and are responsible for involuntary movement. Movement disorders can result from the following: agerelated changes, environmental toxins, genetic disorders (e.g., Huntington’s disease, Wilson disease), medications (e.g., antipsychotic drugs), metabolic disorders (e.g., hyperthyroidism), Parkinson’s disease, and stroke. Mental and neurological disorders are highly prevalent worldwide with 450 million people estimated to be suffering from them. The Global Burden of Disease report drew the attention of the international health community to the fact that the burden of mental and neurological disorders has been seriously underestimated by traditional epidemiological methods that took into account only mortality but not disability rates. This report specifically showed that while the mental and neurological disorders are responsible for about 1 percent of deaths, they account for almost 11 percent of disease burden the world over. The study has demonstrated that magnitude and burden of neurological disorders are huge and that they are priority health problems globally. The extension of life expectancy and the aging of the general populations in both developed and developing countries are likely to increase the prevalence of many chronic and progressive physical and mental conditions including neurological disorders. There is emerging awareness that movement disorders rank among the most common neurological diseases. However, the overall burden of these disorders in the general community is not well defined. Disorders of movement due to basal ganglia dysfunction are generally classified into two categories: those with too little movement (hypokinesias) and those with excess movement (hyperkinesias). Hypokinetic movement disorders include Parkinson’s disease and atypical parkinsonian syndromes. Hyperkinesias include involuntary movements such as tremor, chorea, dystonia, tics, and myoclonus. Movement disorders are usually diagnosed by “pattern recognition.” The complex diagnostic process is essentially one of phenomenology first, neurologic examination second, and any supportive laboratory testing last. Hypokinetic Disorders Slowness of normal movement (bradykinesia), lack of movement (akinesia), and difficulty initiating movement are the hallmarks of hypokinetic disorders.
While most physicians recognize classic Parkinson’s disease (PD), the many other forms of parkinsonism can be difficult to diagnose and treat. The most helpful finding on examination of a parkinsonian patient is the presence or absence of resting tremor in one limb. If such a tremor is present, idiopathic PD is the likely diagnosis.At the present time, a cure for PD is not yet available, although progress is occurring at a rapid pace. Until a cure is proven, the treatment of PD symptoms is not mandatory unless the symptoms are disabling. The patient’s age, occupation, location of symptoms, and so forth, must be considered before beginning treatment. It is also important to note that the treatment strategy differs for different age groups. Patients with atypical parkinsonism or secondary parkinsonism (i.e., due to stroke or toxin exposure) do not typically respond well to standard anti-Parkinson’s medications. The most common of those disorders seen by clinicians include multi-infarct parkinsonism, progressive supranuclear palsy, and diffuse Lewy Body disease. The last appears as concomitant dementia, affective disturbance, and parkinsonism. Such patients may have REM behavior disorder. When exposed to neuroleptic medications, they may become profoundly rigid and bradykinetic. When patients begin to have complications from advancing PD, referral to a PD specialist is generally warranted. There are an increasing number of pharmacological and surgical strategies available even for complex patients. Hyperkinetic Conditions Tics are fragments of normal movements or sounds that occur inappropriately and out of context. They are often suppressible for brief periods. There is usually an urge, which precedes the tic, and relief after it occurs. In the most fully developed form,Tourette syndrome (TS) is defined as the presence of movement and noise tics for greater than one year beginning before the age of 21. Transient or less complex tic disorders are common. Generally not considered an illness, tic disorders appear to have a genetic basis but may have some basis in the immune system response to streptococcal infection. Some conditions associated with tic disorders include motor and phonic tics, Tourette syndrome, attention deficit hyperactivity disorder, obsessivecompulsive disorder, learning disabilities, affective
Movement Disorders
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disturbance, and tardive tic disorder. Treatment is not mandatory unless symptoms are disabling. Pharmacological and nonpharmacological interventions must be tailored to the specific problems requiring treatment. Chorea is defined as brief, irregular, nonsustained movements that flow between muscle groups and can be partially suppressible. Other similar types of irregular, flowing movements include athetosis and ballism. Athetosis is slower than chorea and more typically affects distal extremities. Ballism describes large amplitude choreic movements. The etiology of chorea encompasses primary causes such as inherited disorders (e.g., Huntington’s disease, neuroacanthocytosis, Wilson’s disease, and ataxia-telangiectasia), secondary causes (e.g., infections, structural lesions, and metabolic abnormalities), and physiological chorea (seen in infancy). Treatment of chorea is challenging, but symptoms may be controlled with amantadine, neuroleptics, and dopamine depleting agents such as tetrabenazine and reserpine. Myoclonus is the fastest involuntary movement. Typically less than 100 ms in duration, myoclonus arises from loss of inhibitory neuronal control at cortical, subcortical, or spinal cord levels. Differential diagnosis is quite broad and specialized diagnostic evaluation is recommended. The most common cause is cerebral anoxia following cardiac arrest. Treatment may be successful with suppressing medications such as clonazepam or valproate. Involuntary contraction of agonist and antagonist muscles may result in postural deformity. Dystonia results from uncontrolled cocontraction of agonist and antagonist muscles causing abnormal postures of the affected body part. It can be classified by location (focal or generalized) or by etiology. Examples of focal dystonia include cervical dystonia (torticollis), blepharospasm, task-specific dystonia (writer’s cramp, embouchure dystonia), and spasmodic dysphonia. Generalized dystonia can result from inherited disorders including DYT-1 dystonia (Oppenheim dystonia) and dopa-responsive dystonia, from perinatal injury or from heredodegenerative diseases (Wilson’s disease, Huntington’s disease, among others). Tremor Tremor results from involuntary, alternating, rhythmic contractions of agonist and antagonist muscles and is typically classified by the position of the limb
1142
Movement Disorders
in which it is manifest: rest, postural, or action (kinetic). Rate, amplitude, and rhythmicity are also useful descriptors for tremor when considering its potential causes. There are more than 20 kinds of tremor. While there is overlap in the clinical manifestation of tremor among the various etiologies, it is useful to consider four major categories: parkinsonian, cerebellar, essential tremor, and enhanced physiological tremor. Parkinsonian tremor is characteristically a 3 to 6 Hz rest tremor described as “pill rolling.” Associated hypokinetic features of rigidity, bradykinesia, and gait and postural instability are seen in idiopathic Parkinson’s disease. Parkinsonian tremor is less commonly seen in atypical parkinsonian syndromes (aka, Parkinson-plus syndromes) such as multiple system atrophy and progressive supranuclear palsy. Cerebellar dysfunction resulting from lesions to the cerebellum or its pathways (by infarcts, mass lesions, demyelination, or degenerative diseases) can result in a large amplitude, coarse tremor of the limbs (formerly known as rubral tremor) or trunk (known as titubation) that occurs primarily with action or maintenance of a posture. Essential tremor is a very common movement disorder that is manifested by an 8 to 12 Hz postural and/or action tremor typically in the upper extremities that is most often familial and alcohol responsive. Enhanced physiologic tremor is typically a postural tremor of 8 to 12 Hz similar to that of essential tremor. It may result from metabolic disorders (hyperthyroidism, hypoglycemia), drugs (caffeine, lithium, amphetamines), or stress (fatigue, anxiety). Disorders of Gait Ataxia refers to the wide-based unsteady gait and coordination difficulty usually associated with cerebellar dysfunction. It is important to recognize that some ataxic gaits are due to proprioceptive sensory deficits. These may occur with cervical stenosis and compression of the posterior columns of the spinal cord, vitamin B12 deficiency, neurosyphillis, malabsorption syndromes, and inherited conditions. Modern neuroimaging with magnetic resonance imaging (MRI) and genetic testing have revolutionized our ability to diagnose ataxia. Treatment of reversible conditions, such as B12 deficiency, is obviously the primary goal.
Symptom management with physical therapy and oral medications may be beneficial. Genetic counseling is recommended for appropriate cases. Psychogenic Movement Disorders These are the most challenging of all movement disorders. Rigorous criteria have been proposed for the diagnosis of a psychogenic disorder. It is not simply a diagnosis of exclusion. The most striking feature of psychogenic movements is that they are inconsistent or incongruent with classical disorders. Often, other findings support the diagnosis, such as false weakness or false sensory findings. Multiple somatizations or other psychiatric disturbances may be present. The psychogenic movement disorder may disappear with distraction. When unsure, referral to a movement disorder specialist is strongly encouraged. Although treatment is difficult, a good outcome may be possible when a team approach includes psychiatry or psychology expertise. Movement Disorders in HIV Patients Clinically relevant movement disorders are identified in 3 percent of patients with HIV infection seen at tertiary referral centers. In the same setting, follow-up shows that 50 percent of patients with AIDS develop tremor, parkinsonism, or other extrapyramidal features. Hemiballism-hemichorea and tremor are the most common hyperkinesias seen in patients who are HIV positive, but other movement disorders diagnosed in these patients include dystonia, chorea, myoclonus, tics, paroxysmal dyskinesias, and parkinsonism. Patients with movement disorders usually present with other clinical features such as peripheral neuropathy, seizures, myelopathy, and dementia. In the vast majority of patients, hyperkinesias result from lesions caused by opportunistic infections, particularly toxoplasmosis, which damage the basal ganglia connections. On the other hand, parkinsonism and tremor can result from dopaminergic dysfunction resulting from HIV itself or the use of antidopaminergic drugs. The management of patients who are HIV positive who present with movement disorders involves recognition and treatment of opportunistic infections, symptomatic treatment of the movement disorder, and the use of highly active antiretroviral therapy (HAART).
Mozambique
International Advances in Movement Disorder Awareness Over the years, World Health Organization (WHO) program, projects, and activities in the areas of mental and neurological disorders have been closely linked. To address the large and increasing burden, many activities are being undertaken by the Program on Neurological Disorders and Neuroscience. These are focused on prevention, diagnosis, and treatment of neurological disorders, which are of public health importance as they occur frequently, cause substantial disability, and create a burden on individuals, families, communities, and societies all over the world. These comprise epilepsy, headache, dementias (including Alzheimer’s disease), multiple sclerosis, Parkinson’s disease and other hyperkinetic disorders, stroke, pain syndromes, and brain injury. The program’s main goal is to ensure that an appropriate range of care is made available to all people with neurological disorders in every country of the world. To achieve this, the program emphasizes that neurological services should be provided at all levels of healthcare systems and especially in primary care settings where most patients with neurological disorders receive their treatment and care. The strategies adopted to decrease the public health impact of neurological disorders include collection of epidemiological data; assessment of neurological resources including deficiencies and impediments to adequate healthcare delivery; estimation of human resources; evaluation of costs and health needs; organization of services; research on risk and other public health factors relevant to the prevention and treatment of neurological disorders; education and training of healthcare workers dealing with patients with neurological disorders; planning of programs and policies for the control of neurological disorders; and formulation and implementation of specific strategies for prevention of neurological disorders. In carrying out these activities, WHO has been closely collaborating with the national and international, professional, and nongovernmental organizations concerned with prevention and treatment of specific neurological disorders or in general. SEE ALSO: AIDS and Infections; Chemotherapy; Hun-
tington’s Disease; Immune System and Disorders; Infectious Diseases (General); Neurologic Diseases (General); Parkinson’s Disease; Tremor.
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Bibliography. P. Agarwal and S. J. Frucht, “Myoclonus,”
Current Opinion in Neurology (v.16, 2003); R. Bhidayasiri and D. D. Truong, “Chorea and Related Disorders,” Postgraduate Medical Journal (v.80, 2004); S. B. Bressman, “Dystonia Genotypes, Phenotypes and Classification,” Advances in Neurology (v.94, 2004); E. D. Louis, “Essential Tremor,” Lancet Neurology (v.4, 2005); T. A. Zesiewicz, et al., “Practice Parameter: Therapies for Essential Tremor: Report of the Quality Standards Subcommittee of the American Academy of Neurology,” Neurology (v.64, 2005). Barkha N. Gurbani University of California, Los Angeles
Mozambique Mozambique is located on the southeast coast of Africa, between South Africa and Tanzania. The country was under Portuguese rule for nearly five centuries before winning independence in 1975. A brutal civil war broke out that same year and lasted until 1992; 1 million people died and 5 million were displaced as a result of the fighting. The population is 19.6 million, growing at an annual rate of 1.38 percent. The birth rate is 35.18 per 1,000 and the death rate 21.35 per 1,000. Mozambique remains primarily rural, with 37 percent of the population living in urban areas. Urbanization is growing at a rate of 6.6 percent annually, spurred mostly by the return of war refugees. Most Mozambicans live in poverty. Per capita income in around $250 a year, with 38 percent of the population living on less than $1 a day and 69 percent living below the national poverty line. The economy had been showing signs of rebounding when the country was devastated by flooding in February 2000. Days of heavy rain were followed by a powerful cyclone: 1 million people were affected by the flooding, at least 700 died, and a half-million were left homeless. By 2005, flooding had given way to drought. Humanitarian workers estimated that 800,000 would need supplemental food aid through at least 2006. Life expectancy at birth is 39.53 years for males and 40.13 years for females, with healthy life expectancy averaging 36 years for men and 37 years for women.
1144 Multiple Chemical Sensitivity Infant mortality is 129 deaths per 1,000 births; 159 of 1,000 children die between their first and fifth birthday. Maternal mortality is 1,000 deaths per 100,000 live births. Only 48 percent have a trained attendant present during childbirth. Sanitation is limited, with 24 percent of the rural population having access to clean water and 14 percent using sanitary facilities. Diarrhea is common, as is hepatitis. Malaria is responsible for 15 to 30 percent of the deaths of children under 5. AIDS is a major problem for Mozambique, with a prevalence rate of 12.2 percent. Conservative estimates put the total number of infection at 1.3 million in 2003. In 2005, 16,200 patients were receiving antiretroviral medications out of an estimated 199,000 who needed it. Understanding of the transmission of the virus remains low: in one survey, 20 percent of females and 33 percent of males aged 15–24 had correct knowledge of HIV prevention techniques. Access to medical care in Mozambique is uneven at best. There are 43 hospitals and 1,141 health posts scattered around the country. An estimated 72 percent of people living in rural areas have no nearby care; 53 percent are more than 1 1/2-hours drive from the nearest hospital. Traditional healers are the only option for 60 percent of the people. Half of the country’s 712 doctors work in the city of Maputo. Medical professionals have few opportunities for advanced training. International donors provided close to 70 percent of the country’s total health expenditures in 2000. SEE ALSO: Disease and Poverty; Healthcare, Africa. BIBLIOGRAPHY. Jonathan Kaplan, The Dressing Station:
A Surgeon’s Chronicle of War and Medicine (Grove Press, 2003); Pam Zinkin and Helen McConachie, eds., Disabled Children and Developing Countries (MacKeith Press, 1995). Heather K. Michon Independent Scholar
Multiple Chemical Sensitivity Multiple Chemical Sensitivity (MCS) is a syndrome where multiple symptoms occur with low-level chemical exposure. Since 1989, many definitions of MCS
have existed, which made diagnosis difficult. Since 1999, there is one consensus definition accepted by the American Medical Association, the American Lung Association, the U.S. Environmental Protection Agency, and the U.S. Consumer Product Safety Commission. Using this agreed-upon definition, a diagnosis of MCS can be made, if all six consensus criteria are met: (1) the patient’s symptoms are reproducible with repeated chemical exposure; (2) the condition is chronic; (3) low levels of chemical exposure result in manifestations of the syndrome; (4) symptoms improve when the offending substance is removed; (5) responses occur to many different chemicals that are unrelated; (6) symptoms include multiple organ systems. Patients with MCS syndrome have various symptoms that significantly interfere with their everyday life and work. The typical symptoms occur in three categories: gastrointestinal, respiratory, and the nervous system. Because MCS cannot be totally eliminated, the goal of the physician is to manage the syndrome, which includes utilizing all the physical and psychological treatments available. Defining MCS have been problematic since the Gulf War era when many veterans were coming back from the war with medical symptoms from multiple chemical exposures. Various labels were given to their symptoms. Research studies were conducted by the U.S. Department of Veteran Affairs concerning medical symptoms as a result of chemical exposure during the war. At the same time, in California, civilians with similar symptoms were being diagnosed as having environmental illness. Officials recognized a need to arrive at a common way to describe these civilians and veterans with similar symptoms. Thus, in 1989, multiple chemical sensitivity was defined as a medical syndrome. The more specific symptoms of the patient with MCS is as follows: fatigue, difficulty concentrating, depression, dizziness, weakness, memory loss and headaches, heat intolerance, and athralgias. They report having no symptoms until after they had a significantly large exposure. Some of the large exposures these patients had were to aerosol deodorant, aerosol air freshener, marking pens, cigarette smoke, asphalt pavement, cigar smoke, diesel fuel, diesel exhaust, dry-cleaning fluid, floor cleaner, furniture polish, gasoline exhaust, hair spray, insect repellant, laundry detergent, nail polish, and formaldehyde. Afterward,
Multiple Myeloma
the patient reports having symptoms even in low-level exposure. In addition, they feel certain their symptoms are caused by chemical exposure. The goal of the physician treating patients with MCS, according to specialists in the field today, should focus on management of the syndrome. Many forms of treatment have been proposed. MCS syndrome includes both physical and somatic/psychological. Therefore, rehabilitation needs to address the physical symptoms as well as psychological support. The Occupational Safety and Health Administration (OSHA) established policies that employers must abide by when providing a safe and healthy workplace environment. Some of these are as follows: a smokefree workplace; air monitoring units, which force employers to monitor the air quality; no asbestos in the working areas; carpeting/or paneling that has not been treated with formaldehyde; proper ventilation; limitations on the type and use of air conditioning. SEE ALSO: Air Pollution; Environmental Health; Occupa-
tional Safety and Health Administration (OSHA); Toxicology. Bibliography. American College of Occupational and
Environmental Medicine, “Position Statement. Multiple Chemical Sensitivities,” www.aceom.org (cited November 2006); “Clinical Ecology,” Annals of Internal Medicine (v.111, 1989); M.R. Cullen, “The Worker with Multiple Chemical Sensitivities: An Overview,” Occupational Medicine (v.2, 1987); Michael K. Magill and Anthony Suruda, “Multiple Chemical Sensitivity Syndrome,” American Family Physician (v.58, 1998); C.S. Miller, “White Paper. Chemical Sensitivity: History and Phenomenology,” Toxicology and Industrial Health (v.10, 1994); “Multiple Chemical Sensitivity: A 1999 Consensus,” Archives of Environmental Health (v.54, 1999). Kimberly Fujioka University of California, Berkeley
Multiple Myeloma Multiple myeloma is a devastating malignancy of plasma cells that was first described in 1848. It has diverse presentations but is characterized by
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anemia (a deficiency in the oxygen-carrying component of the blood), bone destruction, elevated blood calcium levels, and renal failure. It currently has no definitive cure, but a number of medications benefit patients. Plasma cells are an integral part of the human immune system and are responsible for secreting antibodies. In multiple myeloma, normal plasma cells are replaced by cancerous plasma cells which function in a disregulated manner. They secrete non-functional antibodies collectively known as the M protein. These antibodies provide no aid in immune function, greatly increasing susceptibility to infections, especially from encapsulated (enclosed by a protective coating or membrane) organisms including Streptococcus pneumoniae and Neisseria menigitidis. The neoplastic cells begin replacing the bone marrow thereby preventing the formation of cells derived from the marrow. This results in impaired red cell production causing anemia. Decreased white blood cell production further leads to infections and reduced platelet formation causes bleeding. Bone pain and destruction is due to the cancerous plasma cells secreting substances which stimulate osteoclasts (the cells responsible for breaking down the bone.) This is a devastating complication burdening patients with fractures of the spine leading to spinal chord compression, severe bone pain and broken long bones. Because calcium is a major component of bones, the increased osteoclastic activity causes increased calcium in the blood. This excess calcium and direct injury to the renal tubules overload the kidneys and subsequently cause them to fail. Myeloma often results in a soft tissue masses (plasmacytomas) and occasionally they overwhelm the kidney as well. Multiple myeloma is preceded by a condition named Monoclonal Gammopathy of Undetermined Significance (MGUS), in which a M protein can be detected, but the end-organ dysfunction characteristic of multiple myeloma is absent. The mechanisms that precipitate the transformation from MGUS to multiple myeloma are unclear. Multiple myeloma accounts for approximately 10 percent of hematological malignancies and the annual incidence age-adjusted to the year 2000 population is 4.3 per 100,000 individuals with 15,000 new cases
1146 Multiple Sclerosis each year. African American are affected around twice as much as whites and it is slightly more common in women. The median age of onset is 66 and the mean survival is approximately three years. Treatment focuses on cancer suppression and on managing symptoms. Medication like bisphosphonates, which inhibit osteoclast function and prevent bone pain and destruction, along with erythropoietin, which stimulates red blood cell production, should be administered as needed. With infections, antibiotics should be used. Chemotherapy usually begins with an induction therapy aimed at lowering the tumor burden. Subsequently, Autologous Stem Cell Transplant, where an individuals own stem cells are harvested, stored and later returned to them intravenously, is used and has been shown to be efficacious. The medication thalidomide with or without steroids, and the chemotherapeutic agent melphan are often used. Novel agents which have shown to be effective include Bortezomib, a drug called a proteosome inhibitor, and Lenalidomide, a drug similar to thalidomide and an immunomodulatory drug. See also: Cancer (General); Cancer Chemotherapy; In-
fectious Diseases (General); Kidney Failure and Dialysis; Spinal Cord Injuries. Bibliography. Sara Grethlien, Multiple Myeloma, Emedicine, www.emedicine.com/med/topic1521.htm. 2006 (cited July 2007); S.V. Rajkumar and R.A. Kyle, “Multiple Myeloma: Diagnosis and Treatment,” Mayo Clinic Proceedings (v.80/10, 2005). Rishi Subbarayan Northeastern Ohio Universities College of Medicine
Multiple Sclerosis Multiple sclerosis (MS), occasionally called disseminated sclerosis or encephalomyelitis disseminate, is a chronic, inflammatory disease that affects a person’s central nervous system and can cause a variety of symptoms including visual problems, muscle weakness, depression, and difficulties with coordination
and speech, sometimes with severe fatigue and generally resulting in problems with balance and pain. The people most affected by MS are adults, with it being more common in women than men. They tend to be aged 20 to 40, and the condition may last for many years. In terms of epidemiology, about 1 in every 1,000 people in northern Europe, continental North America, Australia, and New Zealand suffer from MS, with the frequency much lower in the Arabian peninsula, Asia, and continental South America. It is also rare in sub-Saharan Africa, with overall statistics showing that it is five times more common in temperate regions than in the tropics, and also that it occurs more often in Caucasians. In fact, in Canada, the Inuit have a 20-times lower likelihood of suffering from MS than other Canadians living in the same area; MS is also extremely rare in Native Americans in North America, Australian Aboriginals, and Maoris from New Zealand. The onset of MS tends to be gradual, with alternating periods of exacerbation when the condition becomes worse, and remission. The initial symptoms often include occasional numbness and/or the feeling of tingling on the side of the face. As it progresses, there tends to be muscle weakness, dizziness, unsteadiness, and gradually either blurred or double vision, or partial blindness. The intensity of all these symptoms increases and declines over many years, but gradually, the periods in remission become shorter and the old symptoms become far more severe. This later leads to bad coordination, an inability to control movement, and bladder dysfunction. By this time, there is usually a heavy degree of depression, often accompanied by memory loss and some emotional instability. As the ability of the person to move becomes worse, he or she often has to use a wheelchair, and many people develop partial or complete paralysis. There are about 30 percent of cases where the disease progresses without any remission, but many people suffering from MS have a normal life expectancy. There has been much medical research undertaken into the causes of MS with evidence tending to suggest that it comes from an autoimmune reaction during which the body’s malfunctioning immune system produces far too many white blood cells called T lymphocytes. These then react with, and subsequently damage, the body’s own cells, in particular the myelin sheath around the nerve fibers in the body. How
Multiple Sclerosis
or why the autoimmune reaction is triggered is not known, but many researchers believe that it may be caused by exposure to a virus. Until the virus—if this is the case—is isolated and methods of dealing with it are discovered, there remains no cure for MS, although there are many medications, such as corticosteroids, that can be used to alleviate the symptoms. To gain more time in remission, immunotherapy with different forms of beta interferon are used. Beta interferon is a protein the body normally produces to modulate the immune response, and use of it has been shown to significantly reduce the severity and frequency of the exacerbation periods of the disease and increase the periods in remission. It was not until 1868 that the French neurologist Jean-Martin Charcot was able to recognize that MS was a distinct and separate disease. He found that patients suffering from it tended to all have dysarthria (problems with speech), ataxia (problems with coordination), and their body experienced tremors. Before Charcot, there had been a number of doctors who had worked with patients suffering from MS but had not been able to recognize it as different from other disorders and conditions. These included the British pathologist and physician Robert Hooper, British professor of pathology Robert Carswell, and French professor of pathologic anatomy Jean Cruveilhier. Charcot’s work was later developed on by other medical professionals; however, some of the diseases they studied were similar to MS but may not have been be MS and are known as multiple sclerosis borderline. These medical professionals include Eugène Devic, Otto Marburg, Paul Ferdinand Schilder, and Joszef Balo. There has also been research by Venezuelan-born U.S. pathologist Baruj Benacerraf who shared the 1980 Nobel Prize for Physiology or Medicine with U.S. immunogeneticist George Snell and French hematologist and immunologist Jean Dausset for their work on the role of genes in the autoimmune diseases such as MS. There have been attempts by medical doctors interested in history to diagnose, by written accounts, people who suffered from MS before 1868 and most agree that Saint Lidwina of Schiedam, a Dutch nun, did seem to be afflicted with MS. From the age of 16 until her death, she had intermittent pain, weakness in her legs, and increasingly impaired vision. Another person who almost certainly also suffered from MS
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was Augustus Frederick d’Este, an illegitimate son of Prince Augustus Frederick, who was a son of King George III of Great Britain. He left a detailed diary in which he first felt symptoms similar to MS when he was 28 attending the funeral of a friend. He then continued to suffer for the rest of his life—his diary, stopping shortly before his death, details 22 years with the disease that led to increasing weakness, clumsiness, dizziness, bladder problems, and erectile dysfunction, symptoms that match MS. In 1844, he was confined to a wheelchair and his condition prevented him from making entries in the period immediately before his death. Another diarist who also described his suffering from MS was W. N. P. Barbellion (pseudonym for Bruce Frederick Cummings), whose diary, The Journal of a Disappointed Man, was published in 1919. Many well-known people have suffered from MS in recent years, and there has been a raised public awareness of the disease. U.S. writer Stanley Elkin set his novel The Franchiser (1976) around Ben Flesh, an orphaned bachelor who suffers from MS, as did Elkin himself. Actress Julie Andrews performed on the stage in Duet for One (1986) showing the life of someone with MS. Actor David Niven suffered from lateral sclerosis, and British actress Margaret Leighton, British cellist Jacqueline du Pré, and U.S. actress Tamara Dobson have all died after long battles with MS. Many media personalities have also suffered from MS, with U.S. television talk show host Montel Williams being diagnosed in 1999; and Neil Cavuto, financial commentator on FOX News, also having been diagnosed with MS 10 years after he had been notified that he had cancer. As with cancer, there are many charities and charitable foundations established to help people with MS and their families. SEE ALSO: Immune System and Disorders; Spinal Muscu-
lar Atrophy.
Bibliography. Peter Behan and Abhijit Chaudhuri, “The
Pathogenesis of Multiple Sclerosis Revisited,” Journal of the Royal College of Physicians of Edinburgh (v.32, 2002); Abhijit Chaudhuri and Peter Behan, “Multiple Sclerosis Is Not an Autoimmune Disease,” Archives of Neurology (v.61, 2004); Stuart D. Cook, Handbook of Multiple Sclerosis (Taylor & Francis, 2006); M. Fillipi, et al., “Evidence for Widespread Axonal Damage at the Earliest Clinical Stage of Multiple
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Mumps
Sclerosis,” Brain (v.126, 2003); Elizabeth Forsythe, Living with Multiple Sclerosis (Faber, 1979); M. Langgartner, I. Langgartner, and M. Drlicek, “The Patient’s Journey: Multiple Sclerosis,” British Medical Journal (v.330/7496, 2005); Claudia Lucchinetti, et al., “A Quantitative Analysis of Oligodendrocytes in Multiple Sclerosis Lesions—A Study of 113 Cases,” Brain (v.122, 1999); David Luterman, In the Shadows: Living and Coping with a Loved One’s Chronic Illness (Jade Press, 1995); R.A. Marrie, “Environmental Risk Factors in Multiple Sclerosis Aetiology,” Lancet Neurology (v.3/12, 2004); T.J. Murray, Multiple Sclerosis: The History of a Disease (Demos Medical Publishers, 2005); Donald W. Paty and George C. Ebers, eds., Multiple Sclerosis (F.A. Davis, 1998); A.D. Sadpvnick, et al., “Evidence for Genetic Basis of Multiple Sclerosis: The Canadian Collaborative Study Group,” Lancet (v.347, 1996). Justin Corfield Geelong Grammar School
Mumps Mumps is an acutely contagious disease caused by a virus that most typically affects young people under the age of 15. In children, mumps can be uncomfortable but is not generally medically dangerous, although its incidence in adults, which is also possible, may be more serious. In many countries, children receive a combination of vaccines combating mumps, measles, and rubella (MMR) that has proved very successful in reducing deaths caused by these diseases. Unfortunately, poorly reviewed research in recent years has needlessly caused concern over the safety of this vaccine. Mumps is also known as infectious parotitis (inflammation of the salivary glands) and it is spread by airborne droplets caused when infected patients sneeze or cough, because the responsible paramyxovirus is contained within the saliva. A paramyxovirus is a single-stranded RNA virus that has a substantially sized family of related viruses that cause a variety of diseases. The rapidity with which the disease spreads can give rise to epidemics, especially among children at school. Symptoms may not be visibly evident but might alternatively involve swelling of the salivary glands, which are located on either side of the neck. Other symptoms can include discomfort when chew-
ing or swallowing, tenderness, and fever. This may last for four or five days, but is not severe. In older boys and men, orchitis may develop, which is an inflammatory condition leading to swelling in one or both testicles. In severe cases, this can lead to sterility. Female patients may experience swelling of the breasts arising from the same cause. Rarely, mumps sufferers contract encephalitis, hearing loss, or meningitis. Although vaccines against mumps are easily available and inexpensive, there is no known treatment for a patient who has caught the virus. Having had the disease once is considered to be sufficient protection against ever contracting it again in the future. Medical practitioners advise that all children be vaccinated with the MMR vaccine. There are very minor risks that the mumps portion of the MMR vaccine can lead to aseptic meningitis or parotitis in some children, although they will then recover from this without subsequent effects. The MMR is not linked with autism according to any properly conducted research. The risks of not taking the MMR vaccine are significant both to the individual and to others who might subsequently be infected. The mumps vaccine was discovered by Dr. Maurice Hilleman, who created more than 40 vaccines in the years following World War II, including those for measles, hepatitis A and B, and chicken pox. It has been estimated that his vaccines save some 8 million lives per year. SEE ALSO: Childhood Immunization; Measles; Rubella. Bibliography. Alan Dove, “Maurice Hilleman,” Nature
Medicine (v.11/4S, 2005); A.M. Galazka, S.E. Robertson, and A. Kraigher, “Mumps and Mumps Vaccine: A Global Review,” Bulletin of the World Health Organization (v.77/1, 1999); World Health Organization, “Mumps,” www.who.int (cited May 2007). John Walsh Shinawatra University
Muscle Disorders Muscle tissue has four key characteristics that result in the vital roles muscle tissue plays in the body. These four characteristics are; irritability, contrac-
tility, extensibility and elasticity. Irritability means that a muscle cell has the properties and components to recognized chemical/electrical signals that enable them to play out there specific role in the body. Contractility is the ability of muscle tissue to respond to a particular or appropriate signal, i.e. shorten or contract. In fact, muscle tissue is one of the most specialized contractile tissues found in the body. When muscle tissue is instructed to shorten, that shortening results in; movement at joints in the body, generating heat for temperature regulation, maintaining posture and tone, closing off blood vessels or propelling food through the intestines to name a few. Extensibility is the characteristic that allows muscle tissue to be stretched, like when you flex at the elbow, the extensors of the elbow must be able to stretch to allow flex to occur. Finally, elasticity is the ability of muscle tissue to return to its innate physiologic and functional shape (after being shorten or stretched). Muscle injuries Strains/Sprains. A strain is most severe at the muscle tendon junction and result from stretching a muscle. Strains are graded from I to III depending on the severity. Grade I micro-tears are tender at the muscle tendon junction. Grade II partial tears in the muscle that can be physically felt. A grade III strain is a complete dissociation of the muscle from its tendon. A sprain is an injury involving damage to the ligaments and are also graded I to III. Grade I is stretching of the ligament, grade II is a partially torn ligament and grade III is a completely torn ligament. The pain associated with a sprain is due to edema and bleeding. Epicondylitis are strains of the muscles anchored to the lateral and medial epicondyles (the ridges just above the elbow) that translated into spur formation and inflammation of the bone ridges themselves. Medial epicondylitis is strain of the flexor carpi radialis tendon and is commonly know as golfer’s elbow. Lateral epicondylitis is strain of the extensor carpi radialis longus and brevis and is commonly know as tennis elbow. Both are caused by too tight of a grip and repetitive motions and can become a chronic injury of not treated.
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Autoimmune Myopathies Myasthenia gravis. The most common autoimmune neuromuscular disorder is characterized by degrees of weakness seen in eye and eyelid muscles, muscles of chewing, muscles of the limb and respiratory muscle (respiratory being the most potentially fatal form). Myasthenia is caused by an immune cell mediated attack on receptors and receptor proteins at the neuromuscular junction that is seen in both men and women, with the most common age of onset from the 20s to 30s (most common with women) and 60s to 80s (most common in men). Muscle weakness fluctuates, but appears to get worse as the day goes on or after exercise. Eaton-Lambert Syndrome. This auto immune disease affects skeletal muscle, similar to Myasthenia, however the degree of weakness, distribution, the target receptor, and association is different. Fifty percent of Eaton Lambert syndrome is associated with small cell cancer of the lungs. Inflammatory Myopathies Polymyositis. A rapidly progressive immune mediated inflammatory disease of skeletal muscle, of which the cause is unknown. Polymyositis is more common in women than men and usually shows up in their 50s. Bohan and Peters has established five criteria based off clinical characteristics to identify Polymyositis and are as followed: muscle weakness that is associated at the shoulder and hip joints (w/muscle pain and tenderness), elevates level of muscle enzymes in the serum (due to muscle breakdown), pathologic changes seen with electromyography (muscle conduction), evidence of inflammation seen with biopsy, skin rash (with is the final criteria that distinguishes dermatomyositis from polymyositis) Associated signs and symptoms may include morning stiffness, weight loss, fever, anorexia and fatigue as well as Raynaud’s phenomena (a reactive decrease/ change in blood flow seen in the hands that has a progressive color distribution as you move from the wrist to the fingers; red to white to blue, indicating areas of blood backing up to areas of decreased blood flow. Dermatomyositis. Dermatomyositis is very similar to polymyositis and follows Bohan and Peters criteria, but includes the fifth criteria—a skin rash. The rash is usually the presenting problem and may precede the muscle problem years in advance. The rashes
1150 Muscle Disorders seen with Dermatomyositis can be the conclusive feature to identify this immune mediated condition, also called Gottron’s sign. The skin rash is described as symmetric pink to purple raised rashes found typically on the backs of the fingers, the elbows, the knees and the ankles. Juvenile Dermatomyositis. An immune related disease that affects kids under 16 years of age with a peak onset between 5 to 10 years of age. Girls are affected more than boys, and typical juvenile dermatomyositis presents with warning signs and symptoms that mimic a viral infection, such as generalized weakness, fever, irritability, and muscle aches. A change in their gait and a skin rash may also develop later. Inclusion Body Myositis. An immune mediated myositis similar and associated to polymyositis and dermatomyositis that affects men more than women with a peak onset at the age of 60 years. The diagnosis requires a six year history of symmetric muscle weakness with associated muscle pain that usually begins in the legs and associated muscle wasting that complements the duration of muscle pain and weakness. A biopsy of the muscle would reveal the obvious differences between inclusion body myositis and the other immune mediated myositis diseases. Myositic ossificans. A phenomena that occurs with joint surgery and joint replacement in which, primitive muscle cell precursors transform into bone cells resulting in boney deposition where soft tissue should have been. Myositis ossificans occurs with elderly who have had joint replacement surgery like a hip replacement and may occur in up to 90 percent of all high risk cases. Typically, people will complain of joint stiffness and may be mistaken for an infected prosthesis because the joint may appear, swollen, red, warm and tender.
ly have had a recent upper respiratory infection or gastrointestinal complications prior to this condition and will tend to finally seek medical attention due to swelling, the debilitating muscle aches and pains all over their body or the change in the color of their urine. Interestingly, similar results may occur in which muscle weakness, aches, pains, inflammation and overall muscle break down due to bacterial, fungal and parasitic infections, but are less common than their viral counterparts. Drug or Toxin induced Myopathies. They are among the most common causes of disease in the muscle. It is difficult to compile an accurate list of all the drugs that may cause myopathies. The disease-causing mechanism may be any single route or a various combination of the following: direct/indirect muscle damage, immune system mediated inflammation The problems presented range from mild muscle pain and weakness, to severe muscle pain and weakness, to muscle wasting and potential renal failure. Metabolic Myopathies. Dynamic symptoms related to the underlying deficiency or disease that usually results in muscle pain, exercise intolerance and muscle cramps verses general weakness and may mimic other myopathies and dystrophies. These disorders include; glycogen storages/metabolism diseases, disorders in lipid metabolism, and myoglobinuria. The way someone may present with these problems depends on the underlying disorder, their age, their family history, and overall clinical presentation. Mitochondrial Myopathies. This is generally a progressive disorder with defects in various aspects in the function of the mitochondria, which may lead to associated myopathic signs and symptoms like exercise intolerance, fixed muscle weakness, and myoglobinuria.
Infectious Myopathies Myositis associated with viral infections can range from benign conditions that only cause muscles aches and pains to full blown infections that lead to rhabdomyolysis (destruction of skeletal muscle) which can ultimately lead to renal failure due to the myoglobin clogging up the kidneys. The benign version is usually seen with kids, is very short lived, is almost exclusively limited to the legs, and is usually caused by influenza A and B. People who develop this type of myositis usual-
See also: Muscular Dystrophy; Sports Injuries; Strains
and Sprains.
Bibliography. Charles Brunicardi, et al., Schwartz’s Prin-
ciples of Surgery: A Modern Approach, 8th ed. (McGraw Hill, 2004); Dennis L. Kasper, et al., Harrison’s Principle of Internal Medicine, 16th ed. (McGraw Hill, 2004); Gary A. Thibodeau and Kevin T. Patton, The Human Body in Health and Disease, 2nd ed. (Mosby Inc., 1997); Judith E. Tininalli, et al., Emergency Medicine (McGraw Hill, 2003); Robert L. Wortmann, “Inflammatory Diseases of Muscle and Other
Muscular Dystrophy
Myopathies,” Disease of Skeletal Muscle. (Lippincott Williams & Wilkins, 1996). Ahmed S. Samad, MD Hoffman—La Roche Inc
Muscular Dystrophy Muscular dystrophy encompasses a group of congenital disorders that are commonly characterized by progressive symmetrical degeneration of skeletal or voluntary muscles devoid of neural or sensory deficiency. Conversely, in some forms of muscular dystrophy involuntary muscles such as the heart and additional organs are affected. Connective tissue and fat deposits envelop the deteriorated muscles leading to an artificial perception of muscle strength. Muscular dystrophies are an assemblage of approximately 9 inherited genetic disorders. In addition to the nine classifications there are several variant forms subdivided by method of inheritance and age of onset. The patterns of inheritance are autosomal recessive, autosomal dominate, X-linked recessive and X-linked dominate. A diminutive percentage of cases are caused by spontaneous mutations. Recessive inheritance through multiple generations can also manifest as a spontaneous mutation. There are approximately 43 neuromuscular disorders that are often categorized under the umbrella of muscular dystrophy. There are four major global occurrences of muscular dystrophies. Duchenne’s Muscular Dystrophy First described by the French neurologist Guillaume Benjamin Amand Duchenne in the 1860s Duchenne muscular dystrophy (DMD) is by far the most common form of muscular dystrophy. DMD Accounts for an estimated 50 percent of all cases affecting 1in 3000 to 1 in 4000 births. Current estimates of the total current cases in the United States alone are 15,000 at any given time. The cause of DMD is the complete lack of dystrophin, the protein responsible for keeping muscle cells intact. DMD usually manifests between the ages of 3 and 5. Symptoms include pelvic and leg muscle weakness accompanied by a waddling gait, toe walking, difficulty climbing stairs and scapu-
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lae flare. Some individuals with DMD, approximately one third, may have a slight learning disability. A minute percentage of those affected may be mentally retarded as well. Pattern of inheritance, X-link recessive and principally affects males that inherit the gene from the mother. Females may carry the gene but expression is extremely rare. Progression occurs rapidly and affects all voluntary muscles and eventually involuntary muscles. Those affected usually require a wheelchair between the ages of 9 and 12. Progressive weakness of the cardiac muscles and pulmonary complications result in a life expectancy of twenty years. Becker’s Muscular Dystrophy Similar to DMD a less severe variant Becker muscular dystrophy (BMD) was described by the German doctor Peter Emil Becker in the 1950s. BMD progression is placid in comparison to DMD. The occurrence of BMD is estimated at one tenth that of Duchenne muscular dystrophy although estimates are as high as 1 in 20,000. The cause of BMD results from an insufficient production of dystrophin which results from a mutation on the same gene as DMD. The onset of BMD usually occurs in adolescence or early adulthood. Symptoms of BMD are markedly similar to DMD although less severe and more unpredictable. The legs and pelvic area are affected usually less severely. Shoulder muscles are weakened and results in scapulae flare. Affected individuals are usually able to walk well into their thirties and forties. Pattern of inheritance, X-linked recessive and principally affects males that inherit the gene from the mother. Females may carry the gene but expression is extremely rare. Progression occurs slowly and is highly variable among individuals but can affect all voluntary muscles. Cardiac complications are also common in those affected with BMD. Pulmonary complications can also result from affected involuntary muscles. The life expectancy of those with BMD is middle to late adulthood. Facioscapulohumeral Muscular Dystrophy Debated as the second or third most prevalent form of muscular dystrophy, facioscapulohumeral (FSHD) affects an estimated 1 in 20,000 individuals. FSHD also
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Muscular Dystrophy
known as Landouzy-Dejerine Syndrome is named for the French doctors who described the disease in 1884. An estimated 20 to 30 percent of cases are contributed to spontaneous mutation. The cause of FSHD results from a missing piece of DNA on chromosome 4 causing an asymmetrical distribution of the protein dystrophin. Onset of FSHD occurs between the ages of ten and twenty but can onset at infancy and well into adulthood. Symptoms include weakness of the facial muscles (facio), shoulder muscles (scapulo) and upper arms (humeral). As a result of facial weakness individuals have a pendulous lower lip and an absence of the nasolabial fold on the upper lip. Shoulder and arm weakness leads to scapulae winging and the inability to raise the arms above the head. Males and females are affected equally. Progression occurs slowly with periods of rapid deterioration. All voluntary muscles can be affected requiring about 20 percent of those affected to require a wheelchair. Involuntary complications are usually limited to hearing loss and retinal complications in some cases. Cardiac complications are very rare and life expectancy is not diminished. Limb-Girdle Muscular Dystrophy Analogous to Duchenne muscular dystrophy symptoms, Limb-Girdle muscular dystrophy (LGMD) also known as Erb’s Disease was described by the German neurologist Wilhelm Heinrich Erb in 1884. The frequency of cases is an estimated 1 in 20,000 births. Statistical estimations are debated since there are 15 or more variants of LGMD. The cause of LGMD is decidedly variable and can transpire from a mutation on any of 15 genes. Causation also relates to protein function although more complex compared to the other muscular dystrophies. Six different proteins found in muscle cells can be affected as a result of LGMD. Onset occurs from infancy to adulthood and less frequently during adolescence. Symptoms include weakness of the pelvic and limb girdles, winging scapulae, lordosis, abdominal protrusion, difficulty getting up from a sitting position, climbing stairs and a waddling gait. Patterns of inheritance are variable from autosomal dominant to autosomal recessive. Inheritance can come from one or both parents. Females are affected more than males.
Progression occurs slowly with polar exceptions. Variant versions of LGMD impede the predictability of severity among those affected. Most individuals require the use of a wheelchair to help reduce fatigue. Cardiac complications and pulmonary function may be weakened. Life expectancy is slightly diminished. Additional Classifications In retrospect to the above mentioned muscular dystrophies there are five other rare occurrences of muscular dystrophies. Emery-Dreifuss muscular dystrophy (EDMD) which is caused by a mutation in the genes that produce emerin, lamin A, and lamin B all of which are proteins found in muscle cells. Onset of EDMD occurs around age 10. Symptoms include weakness of the limb girdle, calf muscles and cardiac complications. Progression occurs slowly and inheritance is X-linked recessive primarily affecting males. Additional variants of EDMD are inherited either by autosomal recessive genes or by autosomal dominate genes. Myotonic muscular dystrophy (MMD) also known as Steinert’s Disease results from a repeated section of chromosome 19. Onset ranges from late adolescence to adulthood. Symptoms include weakness of the face, forearms, hands, neck and delayed relaxation after muscle contraction. Complications of the pulmonary, cardiac, gastrointestinal system and vision may occur. Progression proceeds at a very slow rate and the pattern of inheritance is autosomal dominate. The variant form of MMD referred to as Type 2 or (MMD2) is a less common form that occurs from a repeated section of chromosome 3. Type 2 is less severe with similar symptoms. Congenital muscular Dystrophy (CMD) is a group of dystrophies categorized by onset. CMD manifests at birth and usually no later than the age of two. Several variants of CMD exist and causation varies from a host of chromosomal and genetic abnormalities. Symptoms may include muscle weakness, joint stiffness or looseness, mental retardation, pulmonary deficiency, vision problems and seizures. Progression can be highly variable and can result in a shortened life span. Inheritance is autosomal recessive in all forms of CMD. Oculopharyngeal muscular dystrophy (OPMD) results from a gene abnormality that causes an extra binding protein to clump in the muscles. Onset occurs primarily between the ages of 40 to 50. Initial symptoms include weakness of the eyelid muscles, throat
muscles and later limb muscles. Progression occurs slowly and OPMD is inherited by autosomal dominate or autosomal recessive genes. Distal Muscular Dystrophy (DD) is caused by a mutation on any of seven genes that impede protein production essential for muscle function. Onset usually occurs between the ages of 20 to 50. Symptoms of DD are limited to muscle weakness of the hands, forearms and lower legs. Progression occurs slowly and the disease does not shorten life span. Patterns of inheritance occur by either autosomal dominate or autosomal recessive genes. Several other neuromuscular conditions are prevalent and categorized with muscular dystrophy. Motor neuron diseases such as amyotrophic lateral sclerosis (ALS) commonly referred to as Lou Gehrig’s disease and a host of others. Metabolic diseases of the muscles like phosphorylase deficiency and acid maltase deficiency. Diseases of the peripheral nerve like CharcotMarie-Tooth disease. Diseases of the neuromuscular junction such as Myasthenia Gravis and a plethora of other myopathic disorders. Diagnosis Prior to the mid 1980s, diagnosing individuals with muscular dystrophy was decidedly complex. Doctors relied on family history from a parent or other immediate family members as well as their initial clinical findings. Since the mid 1980s there have been several leaps in immunological and molecular biology technology. DNA tests are now available at select medical facilities to confirm the genetic nature of the disease. DNA testing is important since there are several variant forms of muscular dystrophy. Other advantages of DNA testing are identifying inheritance patterns, understanding the rate of progression and categorizing patients for future clinical trials. Muscle biopsies can be taken and examined for muscle fibers and fatty connective tissue deposits. Biopsies are also beneficial in furthering research since a portion of the biopsy can be frozen for future analysis. Also used in diagnosing muscular dystrophy a blood serum assay may be taken to measure for elevations in enzymatic activity. Certain enzymes such as CK (creatine kinase) are only found in certain areas such as the skeletal muscles, heart, and brain. Elevations of CK can mean that the muscles are in essence leaking. Electromyography can also be used to check for electrical activity in the muscle and help
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to differentiate between actual muscle weakness and a neural disorder. Prognosis/Treatment Dissimilarity of progression and the type of the disorder makes formulating a prognosis for any given individual notably unattainable. Approximations can be made based on the particular disease and more specifically on the particular variant of the disease. Often a loose interpretation of progression can be made for an individual based on the clinical history of the disease. In muscular dystrophy irregularity of symptoms can range from death at infancy to a normal life span. Expression of the disease may cause one individual to be completely incapacitated while another individual may express little to no signs of being affected with the same condition. The phenotype of the parents of someone with muscular dystrophy can not be used as a medical model since often the parents are only carriers of a mutated gene or their expression may be less or greater than that of a child. At present there are no known treatments to halt or cure muscular dystrophy. Several therapies are available to help those affected with muscular dystrophy ease through progression and improve their quality of life. Respiratory therapy can be used in an effort to assist patients with breathing techniques if pulmonary function has been compromised. Physical therapy can be useful as a means of helping an individual compensate for muscle weakness. Orthopedic devises may be used to assist with support and mobility. Orthopedic appliances include ankle braces to correct foot drop, back braces to improve posture and leg braces to assist with balance. Affected individuals may also benefit from mobility devices such as electric wheelchairs to reduce fatigue and improve mobility. Corrective orthopedic surgery can be helpful in spinal curvatures such as sclerosis and lordosis. Scapular fusion surgery can help patients increase upward arm mobility and correct scapulae winging in individuals with facioscapulohumeral muscular dystrophy. Certain cardiac abnormalities can be reduced with the use of a pacemaker. Some individuals with Becker’s muscular dystrophy have also benefited from a heart transplant. Several drug therapies are available including corticosteroids to improve strength, immunosuppressants to help suspend cell death, and antibiotics to combat respiratory infections. Assistive technology is also useful in
1154 Myanmar (Burma) improving the quality of life for those affected with a muscular dystrophy. Research Several global efforts are underway to find a suitable cure and treatment for muscular dystrophy. Scientists have successfully isolated the genes that cause most of the fore mentioned diseases. The combined efforts of the world community in understanding the molecular genetics of muscular dystrophy have led to great strides in identifying the individual causation of each unique disease. Efforts to develop suitable gene therapies are currently in progress and pharmaceutical companies have initiated several drug studies. Particular focus has been placed on recombinant human antibodies and other drugs that interfere with myostatin a protein that prevents voluntary muscle formation. Studies on the use of prednisone (a corticosteroid) has had limited results and shows some signs of improving muscle strength although the side affects and long term uses of prednisone as a therapy are still being researched. Scientists are also encouraged by stem cell research however progress in the United States has been impeded as a result of the political and moral indifferences on the subject of stem cells, on the other hand many European and Asian countries are actively pursuing research in stem cells in a combined effort to develop a suitable therapy. Researchers from North America, the United Kingdom, Netherlands, Israel and several additional countries have worked collectively for the past three decades to find a necessary cure. Combined efforts and funding are essential in accomplishing the goal of formulating the correct treatment or cure for muscular dystrophy. Prevalence Currently in the United States the prevalence of the nine muscular dystrophies affects approximately 250,000 people nationwide and over 1 million are affected with a neuromuscular disease included under the umbrella of muscular dystrophy. An estimated 5 to 7 percent of all cases of muscular dystrophy in the United States are unreported. Global estimations of the prevalence of muscular dystrophy are difficult to formulate since medical standards and documentation around the globe are variable. Extrapolated statistics are available for Duchenne’s muscular dystrophy for
several countries. China has the largest number of cases with as estimated 216,000 cases followed closely by India with 177,000 cases. Although cases of muscular dystrophy are usually commensurate with the number of individuals in a population it is important to note that every region of the globe has a significant number of cases. Muscular dystrophy has a momentous impact on Europe, Africa, South America, and Asia. Many countries have implemented programs to specifically help individuals with muscular dystrophy such as the Muscular Dystrophy Association in the United States but in underdeveloped countries throughout the world there is a lack of medical services and social programs to aid individuals with muscular dystrophy leaving the responsibility of care left to an individual’s family. SEE ALSO: Genetic Disorders; Lou Gehrig’s Disease; Mus-
cle Disorders; Myasthenia Gravis; National Institute of Neurological Disorders and Stroke (NINDS); Neuromuscular Disorders. BIBLIOGRAPHY. Stephen J. McPhee, Vishwanash R. Lin-
gappa, Willim F. Ganong, Jack D. Lang, Pathophysiology of Disease (Prentice Hall, 1995); Muscular Dystrophy Association, www.mda.org (cited October 2006). Jeremy John Stansbeary Oklahoma State University
Myanmar (Burma) Burma, now officially known as the Union of Myanmar, is located on the Andaman Sea in Southeast Asia. It is bordered by China, Laos, Thailand, Bangladesh and India. Once a British colony, Burma has suffered repeated bouts of political upheaval and coup d’etats since winning independence in 1948. The country has been under the control of a military junta since 1988. The population is 47,400,000 and growing at 0.815 percent annually. The birth rate is 17.48 per 1,000 and the death rate is 9.33 per 1,000. Median age is 27.4 years. Life expectancy is 60.29 years for males and 64.83 years for females. Gross national income is $220 per person, with about a quarter of the population living in poverty. While Myanmar is rich in natural re-
sources, inefficient governmental policies and political unrest has inhibited growth. Endemic disease comprises a substantial part of the health burden carried by the Burmese people. Poor water and sanitation and overcrowded living conditions throughout the country leads to frequent outbreaks of cholera, plague, dengue hemorrhagic fever, diarrhea, dysentery, typhoid, viral hepatitis, meningitis, and malaria. The tuberculosis rate is 170 cases per 100,000. While the rate of new AIDS infections may be in decline, at 1.3 percent prevalence, it remains among the most serious AIDS epidemics in Southeast Asia, with an estimated 360,000 Burmese infected. While there have been some positive trends in improving the health of the people, the progress is fragile. As Myanmar modernizes, the disease burden is shifting to non-communicable disorders stemming from lifestyle changes, including increased tobacco, drug, and alcohol use. Increased urbanization alone is leading to a more traffic accidents, industrial mishaps, and violence. Health education is poor, particularly in rural areas, where people tend to rely on local cures and miracle injections from unlicensed sources. Child mortality has declined slightly since 1990, with 75 deaths per 1,000 for infants and 105 deaths per 1,000 for children aged 1-5. Acute respiratory infections and diarrhea are the leading causes of under-5 deaths. About 32 percent of children are underweight and stunted. While school enrollment is up, less than 50 percent of children finish primary school. Children go to work in factories or teashops, where they are easily abused or underpaid. An unknown number are trafficked into sex slavery in the region’s many redlight districts. Women in Myanmar have stood at the forefront of the pro-democracy movement, and many have paid the price with imprisonment, torture, rape, forced labor, and relocation. As with children, women are easily exploited as workers or forced into prostitution. The fertility rate is low at 1.95 children per woman, despite a 34 percent contraception prevalence. Three quarters of pregnant women receive prenatal care, and 57 percent have a trained attendant at birth. The maternal mortality rate is 360 deaths per 100,000 live births. The military government has worked to improve healthcare, increasing medical personnel and the number of hospitals and rural clinics. It has also im-
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proved epidemiological surveillance and emergency response to natural disasters. There are 17,800 physicians, 9,900 nurses and 39,400 midwives working in Myanmar today. Government expenditures on healthcare is $0.60 per capita, with most healthcare costs borne by the patients themselves. See Also: Healthcare, Asia; Women’s Health (General). Bibliography. Amnesty International, “Myanmar: Un-
sung Heroines, the Women of Myanmar—Amnesty International,” http://web.amnesty.org/library/Index/engASA160042000 (cited June 2007); “Burma,” CIA World Factbook, www.cia.gov (cited June 2007); International Committee of the Red Cross, “Myanmar’s Health Emergency,” www.redcross.int (cited July 2007). Heather K. Michon Independent Scholar
Myasthenia Gravis Myasthenia gravis is a serious, chronic, debilitating, immunologically-mediated neurologic disease. The disease involves neuromuscular junction and is immunologically mediated. It is an important public health problem because it usually affects those between 20 and 30 years old; however, it may develop at any age. The disease is slightly more common in women. It was first described in the 17th century as a situation of fluctuating weakness. It is seen in one per 17,000 people, in all races. It was a very mortal disease before 1950s; about 70 percent of these patients died because of the pulmonary complications. Since then, mortality was reduced to less than 5 percent by the application of modern ventillation techniques and immunosuppresant and immunomodulatory therapies. Signs and Symptoms Transient or permanent weakness in some or all of the skeletal muscles and abnormal fatigue are the cardinal signs. In more than half of the patients, initial symptoms are related to the involvement of the eye muscles. The most frequent of these is
1156 Myasthenia Gravis the ptosis, which is drooping of the eyelids. Gaze parezies and diplopia may also be observed. Ptosis or weakness in other muscles may be symmetrical or asymmetrical and characteristically shows fluctuation during the day or from day to day. Symptoms are typically heavier toward evening and after physical activity and tend to improve in morning hours and after rest. If the disease is restricted only to the eyes, it is called ocular myasthenia; this is a more benign form of the disease, but unfortunately, only 14 percent of all the myasthenic patients are in this group. In most of the patients, the disease becomes “generalized.” This means that extremity muscles and/or “bulber muscles,” in other words, muscles related to the respiration and swallowing functions, are also involved. Extremity muscles are affected later typically, muscles in the face, chin, tongue, and muscles related to swallowing may be heavily affected when there is no or very slight involvement of the extremity muscles. A patient with generalized myasthenia typically has ptosis, and facial weakness causes a special “myasthenic” facial appearance. Difficulty in swallowing and in talking is seen, which is called “nasal talking.” When the disease becomes worse, trunk, abdominal, and respiration muscles are involved. As a result, difficulty in respiration and coughing occurs, and this results in the accumulation of the secretions and development of pulmonary complications such as bronchitis, atelectasia, and pneumonia. Most of the myasthenic patients show intermittent worsening periods; these are mostly related to the upper respiratory tract infections. If the exacerbation is severe and there is a requirement for endotracheal entubation and respiratory support, this situation may be called a “myasthenic crisis.” Neonatal myasthenia may be present in 12 percent of infants born to myasthenic mothers due to antibodies passively crossing the placenta. Symptoms resolve after a few weeks. Diagnosis Natural history and the presence of the above signs and symptoms suggest the diagnosis. For confirmation, some tests are used. One of them is edrophonium test, an anticholinesterase drug with short duration is applied intravenously; improvement of the muscle function suddenly and briefly confirms the diagnosis. Electrophysiological tests and serological
abnormalities in the blood support the diagnosis. Repetitive stimulation test has a sensitivity of 60 percent and a technique called single fiber electromyography yields up to 95 percent. Acetylcholine receptor antibodies are found in the serum of 90 percent of patients with generalized disease, but only in 50 percet with the ocular form. Computed tomography (CT) of the mediastinum is also employed for a possible abnormality in the thymus gland. Etiology An autoimmune attack destroys the function of the neuromuscular junction, the normal functioning of which is responsible for the normal muscle activity and muscle stregth. İnitiating event leading to this immunological dysfuntion is unknown. In this disease, a gland called thymus is found to be abnormal. Thymic hyperplasia or thymoma, which is the tumoral formation of the gland, may be detected. Very rarely is the disease familial. In these cases, some specific chromosomal expressions may be increased. This shows that genetic tendency is important in myasthenia gravis. Related Disorders Other autoimmune diseases may also present in myasthenic patients. The most frequently found comorbidity is thyroid diseases. Therefor, thyroid functions must be evaluated in myasthenic patients. Treatment Because myasthenia gravis is a chronic disease and sometimes may be difficult to manage, every patient, even ones with mild forms of the disease, must be followed by a specialist. Drugs in the group of acetylcholinesterase inhibitors are used in the symptomatic treatment. Pyridostigmine is the most commonly used anticholinesterase. Dosage must be carefully adjusted to individual requirements. These drugs can cause abdominal cramps and diarrhea. Atropine may be used for gastrointestinal side effects. Anticholinesterases may not relieve all smyptoms especially extraocular muscle paralysis. Corticosteroids and immunesuppresant drugs may be used in the generalized disease and in patients who do not respond to anticholinesterase therapy. Long-term usage of these drugs may cause serious side effects. Thymectomy is applied in cases with thymoma. Benefits of thymectomy in patients without thymo-
Myositis
ma is controversial. In severe exacerbations and in myasthenic crisis, plasmapheresis and intravenous immunoglobulins may be useful. Patients with respiratory paralysis require respiratory support. Prognosis Twenty percent of patients may experience complete or near-complete remission periods which can last at least six months. Mild ocular symptoms may persist in this period. Remission period may last even more than 20 years. The course of the disease shows great variability. Usually, the severity of the disease attains a maximum between 1 to 3 years. Only 7 percent of patients with the generalized disease can perform their daily activities without any prolem. Anticholinesterase medication may not be enough in about one-third of patients with generalized myasthenia. They may become severely weak and develop dysphagia and respiratory problems. Immunosuppressant therapy is given to this group. Worsening may sometimes be related to some factors, the most frequent being infections. Today, mortality of myasthenia gravis is less than 5 percent. Deaths may be seen in all ages, but mostly seen in those between 40 to 50 years. See Also: Dysphagia; Immunosuppression; Immuno-
therapy; Neurological Diseases (General).
Bibliography. D. Grob, “Natural History of Myasthe-
nia Gravis,” Myasthenia Gravis and Myasthenic Disorders, A.G. Engel, ed. (Oxford University Press, 1999); D. Grob, “Course and Management of Myasthenia Gravis,” Journal of the American Medical Association (v.153, 1953); H.J.G. H. Oosterhius, “The Natural Course of Myasthenia Gravis: A Long Term Study,” Journal of Neurology, Neurosurgery, and Psychiatry (v.52; 1989); D.B. Sanders and J.F. Howard, “Disorders of Neuromuscular Transmission,” Neurology in Clinical Practice, W.G. Bradley, et al., eds. (ButterworthHeinemann, 1996); A.S. Penn and L.P. Rowland, “Myasthenia Gravis,” Merrit’s Neurology, 10th ed., L.P. Rowland, ed. (Lippincott Williams Wilkins, 2000). Hakan Yaman, M.D. Akdeniz University Aylin Yaman, M.D. Antalya State Hospital
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Myositis Myositis is a disease with many different outcomes, ranging from mild to debilitating. It is characterized by a chronic inflammation of the body’s immune system that attacks one’s own muscles. The two major types of myositis are polymyositis and dermatomyositis. They are rare disorders affecting approximately 100,000 in the general population. There is a female predominance of 2:1 and a predilection for those in their fifth decade of life. While the two entities share a common immunologic defect, dermatomyositis is also associated with skin as well as muscle. It also carries a much higher malignancy rate. Two additional types of myositis, not as common as DM and PM, include Inclusion Body Myositis (IBM) and Juvenile Myositis. IBM is marked by progressive weakness of the muscles of the body typically occurring after the age of 50. Juvenile Myositis occurs in children with a triad of muscle weakness, skin rash and difficulty swallowing. The diagnostic criteria for both dermatomyositis and polymyositis include five characteristics created by Bohan and Peter in 1973. They include: 1. symmetric proximal muscle weakness, 2. rash, 3. elevated serum muscle enzymes, 4. myopathic changes on an electromyography (EMG: nerve conduction study to determine the strength nerves), and 5. muscle biopsy abnormalities in the absence of histopathologic signs of other myopathies, such as those attributed to bacterial or viral infections. Muscle weakness is the most common presenting symptom, shared by both DM and PM. The onset of the weakness may be acute or chronic progressing in several months. In the elderly population, the esophageal muscles are more likely to be affected, causing difficulty in swallowing (dysphagia) or regurgitation. Muscle tenderness occurs in 25 to 50 percent of cases. The rash manifested in DM has a variety of presentations, but the most common rash, termed Gottron’s sign, is a symmetric, scaly, red/purple hued rash occurring over the knuckles of the fingers. Other distinct rashes seen include those that cover the neck and shoulders, or eyelids, or cracking of the nails and surrounding skin. Muscle enzyme elevation is also a distinct characteristic of DM and PM. Creatine kinase (CK), lactate dehydrogenase (LDH), aldolase, aspartate amino-
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transferase (AST), and alanine aminotransferase (ALT) are the enzymes most commonly elevated. Most patients will experience an elevation of all of the enzymes. An Electromyography (EMG) is a test that measures the severity of any nerve disorders, measures the degree of nerve entrapment, and evaluates muscular and nerve disorders, such as myasthenia gravis. In the presence of DM or PM, an EMG will reveal high frequency discharges, increased activity and spontaneous fibrillations, and abnormal short-duration, low amplitude motor potentials. These findings are not diagnostic, but rather support the diagnosis of DM or PM. It is a useful test to rule out muscle disease due to a neuropathic (nerve) etiology. Muscle biopsies can accurately diagnosis DM or PM. It is recommended that it be obtained from a weak, but not completely atrophic, muscle specimen. An EMG, MRI can aid in the detection of weak muscles. While DM and PM may both exhibit structural changes in the tissue, there are distinct characteristics that identify the two. DM has a predilection for blood vessels within the muscle. There is an immunologic complex called the C5b-9 membrane attack complex. This is a form of immunologic defense set up in a ring like structure on the plasma membranes of cells. PM, on the other hand, does not manifest within blood vessels but rather within the muscle fibers. There are also no signs of any vessel infiltration or any immune complexes. There is increased number of cytotoxic CD-8 T-cells. The most common complication of DM and PM is pulmonary involvement. The four major types of lung disease include interstitial lung disease, infection, respiratory muscle weakness, and drug-induced disease. Interstitial lung disease is characterized by abnormal changes on chest x-ray. Infection is the most common form of pulmonary disease. Decreased esophageal motility, respiratory muscle weakness, drug therapy predisposing to infections, and a depressed immune system are
all risk factors to developing pulmonary disease in myositis. Respiratory muscle weakness presents with a wide range of severity from mild dysphagia to complete respiratory failure. Drug-induced disease has been associated with methotrexate and cyclophasphamide. Treatment for DM and PM consists of glucocorticoid therapy. Glucocorticoid therapy, Prednisone, works by improving the strength of the muscle. To monitor its effectiveness, individuals should have their muscle strength measured as opposed measuring muscle enzyme decline. For those who do not improve after glucocorticoid treatment, azathioprine and methotrexate may be also be used as an alternative or as an adjunct to glucocorticoids. These agents may also reduce the need for a long-term glucocorticoid use, which can exacerbate other medical diseases such as diabetes. Myositis is a disease with no definitive cure, but with proper treatment it can be brought under control. See also: Immune System and Disorders; Rheumatoid
Arthritis.
Bibliography. A. Bohan and J.B. Peter, “Polymyositis
and Dermatomyositis,” New England Journal of Medicine (v.292/7, 1975); M.C. Dalakas and R. Hohlfeld, “Polymyositis and Dermatomyositis,” Lancet Journal (v.362/9397, 2003); Mark Miller, “Clinical Manifestations and Diagnosis of Dermatomyositis and Polymyositis,” UpToDate, www. utdol.org/myositis/index.html (cited September 2006); Stacy Rudnicki, “Treatment of Dermatomyositis and Polymyositis,” UpToDate www.utdol.org/143/myositis/index. html. (cited September 2006); K.E. Tymms and J. Webb, “Dermatopolymyositis and Other Connective Tissue Diseases: A Review of 105 Cases,” Journal of Rheumatology (v.12/66, 1985). Angela J. Garner, M.D. University of Missouri–Kansas City
N Namibia Namibia is located on the Atlantic coast of southern Africa, surrounded by Angola, Zambia, Botswana, and South Africa. It won independence from South Africa in 1990 and has been struggling to find its economic footing as a nation. Despite the fact that it is one of Africa’s biggest environmental polluters, it has also become a prime destination for ecotourism. The population is 2,044,174 and growing at 0.59 percent annually. The birth rate is 24.32 per 1,000 people and the death rate is 18.86 per 1,000 people. A third of Namibians live in urban areas. Population density is 1.5 people per square kilometers, making it the second least densely populated country in the world, beat only by Mongolia. The economy is based on mining (primarily diamonds, uranium, zinc, tin, and silver), augmented by a growing tourism industry. Unemployment is high, with 35 percent of the population living on $1 a day and 56 percent living on $2 a day. Food security has become an issue over the past several growing seasons. Namibia is mostly desert, with infrequent rains and periodic droughts. Up to 30 percent of the population has relied on humanitarian food aid in recent years. Stunting, a sign of malnutrition, is seen is in a quarter of Namibian children.
Life expectancy at birth is 44.5 years for males and 42.3 years for females. Infant mortality is 47 deaths per 1,000 births. Mortality for children between 1 to 5 years is 62 deaths per 1,000. Maternal mortality is 300 deaths per 100,000 live births. Eighty percent of Namibians have access to clean water, but only 30 percent of urban residents and 14 percent of rural residents have access to sanitary facilities. Diarrhea, hepatitis A, and typhoid are common, as is malaria. In 1999, 11 percent of the population was found to suffer from schistosomiasis. There was an also outbreak of polio in 2006. The AIDS rate is high at 21.3 percent, growing primarily through heterosexual contact and motherto-child transmission. At least 210,000 people are infected, and as early as 1996, it became the leading cause of death within the country. Aid agencies are working with Namibia to come up with a prevention and treatment plan for the population. In 2004, the United States gave Namibia $24.3 million to support its programs. According to the Namibian Ministry of Health, a study of 41,548 deaths between 1995 and 1999 found that 19 percent of deaths were the result of AIDS, 10 percent resulted from tuberculosis, 9 percent resulted from acute respiratory disease, 8 percent resulted from cerebrovascular accidents, 7 percent resulted
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National Asian Women’s Health Organization (NAWHO)
from gastroenteritis, 6 percent resulted from malaria, 6 percent from cancer, 4 percent from prematurity, 3 percent from malnutrition, and 3 percent from septicemia. The Ministry of Health believes that 80 percent of the population is within 10 kilometers of a health facility. There were 33 district hospitals, 12 private hospitals, 37 health centers, 244 public clinics, and five private clinics in the country in 2000. Nurses are trained within Namibia, usually as part of four-year degree program. All doctors are foreign trained. In 2000, there was 1 doctor for every 7,545 people and one nurse for 947 people. SEE ALSO: Healthcare, Africa. Bibliography. Tara Waters Lumpkin, Traditional Heal-
ers and Community Use of Traditional Medicine in Namibia (UNICEF, 1994). “Namibia,” CIA Wold Factbook, www. cia.gov (cited July 2007). Heather K. Michon Independent Scholar
National Asian Women’s Health Organization (NAWHO) The National Asian Women’s Health Organization (NAWHO), created in 1993, promotes health equality for Asian-American women and their families through overall education about their health needs and through specifically targeted initiatives. NAWHO empowers Asian Americans by providing leadership training and by collaborating with other agencies, such as the Centers for Disease Control and Prevention (CDC), to make health-related goals a reality. It is sometimes assumed that Asian Americans do not suffer from health problems to the degree that other minority populations do. This has been dubbed the “healthy model minority myth” and NAWHO has focused much of its efforts toward dispelling this myth and providing concrete health information on diseases that afflict Asian-American women, such as breast and cervical cancer, and diabetes; on culturally based vulnerabilities such as
sexual violence and mental illness, wherein traditional cultural behavior and upbringings may prevent Asian-American women from responding in an empowering manner; and on issues that affect the entire Asian-American family, such as broader immunization coverage. More specifically, NAWHO is currently sponsoring “Transforming Information into Action: The National Asian-American Diabetes Project” through a collaboration with the CDC and the National Diabetes Education Program (NDEP). Through this program, NAWHO strives to raise diabetes awareness among Asian Americans and Pacific Islanders (AAPIs) and to diminish its occurrence, morbidity, and mortality rate. Another initiative, “Breaking the Silence: Preventing Violence against Asian-American Women,” is a joint venture with the National Center for Injury Prevention and Control and has a target audience of Asian-American college students. This initiative aims to dispense information about intimate partner violence. A related program, “The National AsianAmerican Reproductive Health and Rights Project,” focuses more generally on reproductive and sexual health rights of Asian-American women. Through a series of health assessments, NAWHO has gathered information for healthcare professionals and government policy makers, with the end goal being advocacy of comprehensive healthcare for AsianAmerican women. NAWHO focuses more specifically on mental health concerns with “Empowering Avenues for Community Action in Mental Health: The National Collaborative for Asian-American Women’s Health.” This initiative focuses on lowering depression and suicide rates among Asian-American women aged 18–34. It hopes to accomplish this by eliminating the stigma of seeking help for mental health issues, by increasing the opportunities for Asian-American women to receive relevant healthcare referrals, and to assist Asian-American women in a quest to serve in mental health leadership positions. The final current initiative, “Promoting Prevention for Healthy Communities: The National AsianAmerican Immunization Project,” focuses both on Asian-American women and their families. To achieve this goal, NAWHO is conducting a national education campaign to share the importance of
National Association of Health Data Organizations (NAHDO)
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National Association of Health Data Organizations (NAHDO)
The National Asian Women’s Health Organization promotes health equality for Asian-American women and their families.
timely immunizations. NAWHO also funds collaborative partners, providing more than $1.4 million to over 50 organizations that focus on the health of Asian-American families. SEE ALSO: Asian-American Health; Centers for Disease
Control and Prevention (CDC); Diabetes; National Center for Injury Prevention and Control (NCIPC). Bibliography. National Asian Women’s Health Organi-
zation, www.nawho.org (cited July 2007); Lorri A. Zipperer, ed., The Health Care Almanac: A Resource Guide to the Medical Field (American Medical Association, 1995). Kelly Boyer Sagert Independent Scholar
The National Association of Health Data Organizations (NAHDO) is an educational and charitable organization that collects, analyzes, and makes available health data to improve healthcare. NAHDO merges health-related data from public/government entities with private institutions and healthcare organizations; NAHDO then provides the amalgamated data to healthcare policy makers to assist them in making quality strategic decisions. NAHDO was founded by the Washington Business Group on Health (WBGH) and the Intergovernmental Health Policy Project (IHPP) in 1986. The initial conference included those two organizations plus state data organization (SDO) representatives from Arizona, Colorado, Iowa, Maryland, New Hampshire, New Jersey, and Tennessee. Initially, NAHDO’s sole function was to support the SDOs responsible for collecting, reviewing, and distributing data listed in hospital discharge forms. In 1989, NAHDO’s Board of Directors opened up membership opportunities to incorporate private forprofit and not-for-profit entities. Currently, the scope of NAHDO’s membership includes SDOs, governmental agencies, peer-review organizations, members of the media, computer software and hardware agencies, consultation groups, and university experts, as well as state and regional hospital association representatives and health service research organizations. The objectives of NAHDO have been expanded to support public domain health data organizations in the development and use of their data to address issues on national, state, local, and individual patient levels; ensure the consistency and standardization of health data collection and distribution methods in public and private sectors; encourage collaboration between public and private organizations that gather, assess, and distribute health data; foster the development of consistent privacy directives and stringent penalization for misappropriation of personal health data; and serve as a centralized resource center for current healthcare information developments, trends, and expertise. NAHDO has created standards for the collection, analysis, and distribution of data/information to support
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healthcare reform; the organization supports a health information system that is publicly controlled and constructed on the foundation of public and private health systems currently in operation. The organization maintains a Technical Assistance for Health Data Organizations Web site for its members with a primary goal of improving the quality of healthcare data. Their Quality Reporting Workgroup (QRW) coordinates the exchange of quality reporting initiatives; helping state organizations implement these initiatives; and listening to and responding to needs for new programs. The Web Data Dissemination Toolkit (WDDT) is charged with improving state and local health information systems and with facilitating the sharing of information between state agencies and other healthcare organizations, and to push for national standardization of health data use. NAHDO maintains a clearinghouse wherein SDOs share information about their methodologies, medical term definitions, data collection protocol, and reporting criteria, so that health agencies do not need to contact other health organizations individually in their effort to standardize procedures, policies, and linguistics in data collection, analysis, and distribution. This clearinghouse also reduces the information-sharing burden on states and organizations with more advanced data use systems. SEE ALSO: National Center for Health Statistics (NCHS);
The National Center for Public Health Informatics (NCPHI). Bibliography. National Association of Health Data
Organizations, www.nahdo.org/default.aspx (cited June 2007); Lorri A. Zipperer, ed., The Health Care Almanac: A Resource Guide to the Medical Field (American Medical Association, 1995). Kelly Boyer Sagert Independent Scholar
National Association of People with AIDS The National Association of People with AIDS (NAPWA) is the oldest organization lobbying for the rights
of people living with AIDS. In 1983, mostly gay and lesbian AIDS patients advising the Second National AIDS forum founded NAPWA as a means of transmitting their concerns as patients to governmental bodies making decisions on their behalf. Then, as now, the group focused strongly on ensuring that they did not become ‘victims’ of AIDS, and places much importance on training HIV positive people to become advocates in their own treatment, care, and policies. The majority of board members and staff are themselves living with HIV or AIDS. The Association has come to recognize the increasing transmission rates among heterosexuals in the United States, particularly among minority populations, and now includes members from all sexual orientations and social groups. One particular aspect of the NAPWA is its emphasis on integrated community care for AIDS patients, including access to meals, housing, and social services, in addition to medical care. Often, the organization funds local community efforts by persons living with HIV and AIDS to provide their own services. The NAPWA also strongly encourages the acceptance of the right of HIV-positive individuals to sexual intimacy, and advocates for prevention programs aimed at people who are already HIV positive as a means of reducing new infections, a population frequently ignored by government and other public health HIV prevention campaigns. The group has been instrumental in successfully lobbying for the establishment and maintained funding for federal programs that fiscally support HIV treatment and care, such as the Ryan White Care Act. Other activities include an annual nationwide day aimed at encouraging atrisk individuals to undergo voluntary HIV counseling and testing, and raising public awareness of HIV and AIDS in the United States. Although initially founded as a United States-centric organization, NAPWA has expanded its focus to incorporate promoting the agenda of AIDS victims worldwide, often by cooperating with local organizations of persons living with HIV or AIDS, such as the Network of African People Living with HIV/AIDS. As an extension of its work in the United States, the NAPWA trains HIV positive leaders abroad how to become advocates for their own treatment, and also works to dispel HIV-related stigma and discrimination at home and abroad. The NAPWA also now lob-
National Breast Cancer Coalition (NBCC)
bies the United States government regarding policies that affect people living with HIV and AIDS elsewhere, such as trade and patent laws, funding for care and treatment, and especially on the discriminatory ban that bars HIV positive people from traveling to the United States. SEE ALSO: AIDS; AIDS—Living with AIDS; National Cen-
ter for HIV, STD, and TB Prevention (NCHSTP).
Bibliography. The American Association of Colleges
for Teacher Education, Humanizing Pedagogy Through HIV and AIDS Prevention: Transforming Teacher Knowledge (Paradigm Publishers, 2006); National Association of People with AIDS web site, http://www.napwa.org/ (cited July 2007). Annie Dude University of Chicago
National Breast Cancer Coalition (NBCC) Approximately 200,000 cases of breast cancer are diagnosed each year. Breast cancer is the second leading cause of cancer deaths among women (outranked only by lung cancer), and around 40,000 women die each year from this disease. No method has yet been devised to prevent breast cancer. While research, new treatments, and early detection through mammograms and self-examination have all played a crucial role in cutting death rates, many facts about breast cancer remain elusive. Researchers have been unable to explain why progression rates vary or why some cancers return and others do not. In light of the importance of breast cancer research, the National Breast Cancer Coalition (NBCC) was founded in 1991 as an umbrella organization for groups involved in the battle to eradicate breast cancer. NBCC membership includes 70,000 advocates and 600 organizations such as cancer support, information, and service groups and healthcare and provider organizations. Through these organizations, several million patients, healthcare professionals, women, and families and friends of breast cancer patients are represented. In 2003, NBCC was named to a list of
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the 20 most influential health policy groups in the United States. The organization is headquartered at 1101 17th Street, NW, Suite 1300, Washington, D.C. 20036. Information on the coalition is available by telephone (1-800-622-2838) or on the internet (http:// www.natlbcc.org/). NBCC lobbies all levels of government to seek increased funding for breast cancer research, diagnosis, and treatment. NBCC advocates work with the academic and scientific communities to generate new research, improve healthcare and breast cancer clinical trials, and expand the scope and influence of advocacy activities. As a sister organization, the National Breast Cancer Coalition Fund trains NBCC advocates to make them more effective and provides the public with an extensive body of information on this disease. Breast cancer education and leadership skills are promoted through Project LEAD (Leadership, Education, and Advocacy Development), a four-day course taught by researchers, scientists, and physicians. The coalition also sponsors an annual advocacy training conference. The first international conference on breast cancer advocacy was held in Brussels, Belgium, in 1997. NBCC advocacy efforts have been successful in influencing the decision to create a new breast cancer research program under the Department of Defense and in the implementation of the National Action Plan on Breast Cancer, for which NBCC provides oversight. Other accomplishments include passage of the Breast and Cervical Cancer Treatment Act, the Access to Cancer Therapies Act, and the NativeAmerican Breast and Cervical Cancer Treatment Technical Amendment Act. NBCC pressure was also responsible for the extension of Medicare coverage for basic care during clinical trials and a 50 percent increase in breast cancer funding through the National Cancer Institute. Although no cure for breast cancer yet exists, the mammogram has proved to be a successful tool in identifying cancers, even in early stages. However, despite strong evidence that mammograms are successful at diagnosing most cancers and despite irrefutable proof that early detection is essential in mitigating the effects of breast cancer, many American women do not undergo the procedure at recommended intervals. Reasons for failing to do so include limited availability, inadequate insurance coverage,
1164 National Cancer Institute (NCI) misunderstandings of the process, fear, and pain. The fact that mammograms are not always effective with dense breast tissue discourages some women. In three-fourth of all breast biopsies, growths are found to be benign. One in six mammograms fails to identify cancer, and one in ten results in false positives. Treatments for breast cancer patients generally include radiation, chemotherapy, and surgery. In consultations with healthcare workers and support groups, patients may opt for lumpectomies, which remove only cancerous sections and surrounding tissues, or total mastectomies in which either or both breasts are removed. Some physicians have been criticized for recommending radical treatments when less invasive solutions would suffice. SEE ALSO: Breast Cancer; National Cancer Institute (NCI);
Women’s Health (General).
Bibliography. David S. Alberts and Lisa M. Hess, eds.,
Fundamentals of Cancer Prevention (Springer, 2005); Ismail Jatoi and S. Eva Singletary, eds., Breast Cancer: New Concepts in Management (Saunders, 2003); Janet E. Joy, et al., eds., Saving Women’s Lives: Strategies for Improving Breast Cancer Detection and Diagnosis (National Academics Press, 2005); Shahla Masood, ed., Contemporary Issues in Breast Cytopathology (Saunders and National Breast Cancer Coalition, 2005); Musa Mayer, After Breast Cancer: Answers to the Questions You’re Afraid to Ask (O’Reilly, 2003); Measuring the Quality of Breast Cancer Care in Women (Agency for Healthcare Research and Quality, 2004). Elizabeth R. Purdy, Ph.D. Independent Scholar
National Cancer Institute (NCI) The National Cancer Institute (NCI) was established in 1937 under the National Cancer Institute Act. The agency was charged with the overall goal of reducing the burden of cancer worldwide. The National Cancer Act of 1971 greatly broadened the scope of NCI and this institute is now 1 of the 27 National Institutes of Health (NIH) established by Congress. Starting in 1971, NCI was charged with conducting
and facilitating cancer-related research, training and educating researchers, and reviewing and selecting projects to fund with grant research money; these projects must focus on discovering causes of cancer, or diagnosing, preventing, and/or treating the disease. NCI was also given the responsibility of disseminating cancer-related information to healthcare professionals, governmental agencies, and the general public. NCI is also one of the eight agencies of the Public Health Service (PHS) sector of the U. S. Department of Health and Human Services (HHS). Because of research conducted by NCI and other collaborative agencies, cancer deaths declined in 2003 when compared to 2002; although the decline was only by 369 people, this was the first drop in cancer-related deaths since 1930. NCI-connected research has resulted in at least 20 people receiving the Nobel Prize, with NCI funding about half of these award-winning projects and supplementing knowledge from NCI research in others. Projects include the discovery of the segmental nature of eukaryotic genes, RNA splicing, oncogenes, and reverse transcriptase, as well as clinical applications such as magnetic resonance imaging, allogeneic bone marrow transplantation, and hormonal treatments for cancer. Moreover, this research has furthered scientists’ understanding of many disciplines, including genetics and physiology. In 1982, NCI released the Physician Data Query (PDQ) system to provide timely electronic information to healthcare professionals; the cancer Biomedical Informatics Grid (caBIG) is furthering this initiative. In 1998, NCI began overseeing the Office of Cancer Complementary and Alternative Medicine (OCCAM). This division studies the effects of alternative treatments; this includes acupuncture, a treatment used in Asian countries for thousands of years and in the United States for about 200. Acupuncture is used to reduce pain associated with cancer and to reduce vomiting caused by chemotherapy. It is thought that acupuncture works by creating responses in nerve cells, the pituitary gland, and sections of the brain, and it is theorized that it may assist the immune system in operating more effectively. Mistletoe is also used in cancer experiments; its extract has destroyed cancer cells in laboratory set-
National Center for Chronic Disease Prevention and Health Promotion (NCCDPHP)
tings; as with acupuncture, mistletoe is believed to support the immune system and reduce side effects from traditional cancer treatments. Mistletoe-based clinical experiments on human subjects have shown mixed results. Yet another OCCAM research topic is the use of cow and shark cartilage as a cancer treatment. In laboratory settings, this form of cartilage has destroyed cancer cells, boosted the immune system, and prevented the growth of new blood cells necessary for new tumor growth. In 2004, NCI announced a major commitment to exploring nanotechnology—the engineering of devices so small as to be measured by molecules—as a significant tool in the fight against cancer. NCI has earmarked over $144 million for this five-year initiative, believing that this technology will further knowledge of the molecular nature of cancer. To carry out this collaboration, NCI formed the NCI Alliance for Nanotechnology in Cancer, partnering with physicists, biologists, clinicians, and engineers. Collaborations between cancer treatment experts and nanotechnology experts has already led to the discovery of liposomes, drugs delivered directly to tumors to fight cancer and/or to combat infections common with aggressive cancer treatments. Clinicians also hope to use nanotechnology to identify cancer at its earliest stages, which expands viable treatment options, increases the success rate of these treatments, and allows researchers to learn more about the earliest formation of types of cancer, knowledge that will be used to further combat cancer growth. On the NCI Web site, information is provided on a wide range of topics, with broad topics often written two different ways: one for the patient and the other for the health professional. Topics include fatigue; pain control; complications and side effects of treatments; nutritional concerns; emotional issues such as anxiety, depression, post-traumatic stress disorder, substance abuse issues, and spirituality; treatment issues; clinical trials; caregiver information; survivorship; and end-of-life issues. NCI is required to present an annual report to the president of the United States; the most recent report is titled, The Nation’s Investment in Cancer Research: A Plan and Budget Proposal for Fiscal Year 2008.
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SEE ALSO: Alternative Medicine; American Cancer Soci-
ety (ACS); Cancer (General); Cancer Alternative Therapy; National Institutes of Health (NIH).
Bibliography. National Cancer Institute, http://www.
cancer.gov (cited July 2007); “National Cancer Institute Announces Major Commitment to Nanotechnology for Cancer Research,” PR Newswire (September 13, 2004), http://www.highbeam.com/doc/1G1-122095486.html (cited July 2007). Kelly Boyer Sagert Independent Scholar
National Center for Chronic Disease Prevention and Health Promotion (NCCDPHP) The National Center for Chronic Disease Prevention and Health Promotion (NCCDPHP) is the division of the Centers for Disease Control and Prevention (CDC) that oversees programs that combat chronic diseases in the United States. NCCDPHP collaborates with health and education agencies and private sector and voluntary associations to prevent death and disability arising from chronic diseases through the promotion of healthy behaviors. It particularly focuses on the health of infants, teens, and pregnant women, and on health conditions that occur more frequently in women and minorities. Many Americans, as many as 1.7 million people, die annually from chronic diseases such as cancer, diabetes, and cardiovascular disease (primarily heart disease and stroke). The cost for treatment of people with chronic diseases accounts for 75 percent of the nation’s $1.4 trillion spent on medical care. Chronic diseases are among the most common health problems in America and are also frequently the most avoidable; to reduce chronic disease, NCCDPHP, therefore, advocates for positive behaviors such as eating healthy and nutritious diets, engaging in regular physical activity, and avoiding tobacco. To combat the high cost of chronic disease medical care and to improve the overall health of the nation, NCCDPHP supports a wide range of programs that
1166 National Center for Complementary and Alternative Medicine (NCCAM) denote chronic disease risk factors and promote the prevention of chronic diseases. NCCDPHP provides information on topics such as arthritis, cancer, diabetes, genomics, global health, healthy aging, healthy youth, heart disease and stroke, nutrition and physical activity, oral health, prevention research facilities, and tobacco. It offers information about health-related programs such as the congressionally mandated Preventative Health and Health Services Block Grant, a source of funding for public health initiatives to prevent diseases; Racial and Ethnic Approaches to Community Health (REACH), CDC’s attempt to eliminate racial and ethnic disparities in health; Safe Motherhood, a program that advocates for women’s health before, during, and after pregnancy; Steps to a Healthier U.S. Cooperative Agreement, the U.S. Department of Health and Human Services’ (HHS) initiative to improve health nationwide; and WISEWOMAN, a CDC-funded program that helps women without insurance obtain health screenings and reliable information on how to reduce risks for chronic diseases. To find ways to prevent chronic diseases, the NCCDPHP monitors health data to calculate the prevalence of risk factors among populations; to determine the success of prevention efforts; and to help both public health officials and legislators make quality decisions. Specific chronic disease surveillance systems include the Behavioral Risk Factor Surveillance System, a telephone health survey program that tracks health conditions and risk factors in the United States; the Youth Risk Behavior Surveillance System, which more specifically targets risk behaviors among youth and young adults, as behavior patterns are established during those years; the Cancer Registries; Pregnancy Risk Assessment Monitoring System; and the Pediatric and Pregnancy Nutrition Surveillance System, which provides information and training on reading data tables, their interpretation, value in program evaluations, and effective dissemination through reports. SEE ALSO: Centers for Disease Control and Prevention
(CDC).
Bibliography. National Center for Chronic Disease
Prevention and Health Promotion http://www.cdc.gov/
nccdphp/ (cited July 2007); Lorri A. Zipperer, ed., The Health Care Almanac: A Resource Guide to the Medical Field (American Medical Association, 1995). Kelly Boyer Sagert Independent Scholar
National Center for Complementary and Alternative Medicine (NCCAM) Established by Congress in October 1998, the National Center for Complementary and Alternative Medicine (NCCAM) is the leading scientific research agency in the United States that explores complementary and alternative medicine (CAM) methodologies and therapies, which are not considered part of mainstream medical practices. NCCAM is a division of the National Institutes of Health (NIH), a branch of the U.S. Department of Health and Human Services (HHS). NCCAM studies complementary and alternative healing therapies using strict and rigorous scientific methods and it attempts to validate or disprove CAM disciplines; to that end, it funds more than 1,200 research projects worldwide. It trains new CAM researchers and support CAM professionals, providing funding and awards to them; distributes research results to scientific professionals and the public through its web site, fact sheets, lecture series, and publication database; and encourages the integration of CAM practices found to be safe and effective into standard medical practices, while practicing careful stewardship of NCCAM resources. NCCAM conducts and supports basic and clinical research and large clinical trials in CAM’s four domains. The first domain involves manipulative and body-based therapies such as chiropractic and osteopathic manipulation, massage therapy, and reflexology. Between 3 and 16 percent of American adults visit a chiropractor each year, and between 2 and 14 percent receive massage therapy. Collectively, these
National Center for Environmental Health (NCEH)
two types of treatments account for 50 percent of all CAM therapies provided in the United States annually. This type of treatment focuses on bones, joints, soft tissues of the body, and circulatory and lymphatic systems. The second research domain covers biologically based practices such as botanicals, animal-derived extracts, vitamins, whole diets, and functional foods. The Food and Drug Administration (FDA) regulates dietary supplements, albeit less strictly than prescription and over-the-counter drugs. In 2002 alone, Americans purchased $18.7 billion worth of dietary supplements, with herbal and botanical supplements serving as nearly one-fourth of these purchases. The third NCCAM research domain includes mind–body medicine, which focuses on the relationship between the brain and the body, and the ways in which emotional, mental, and behavioral factors influence physical health. These include relaxation and visual imagery techniques, hypnosis, meditation, yoga, biofeedback, tai chi, and many cognitive and behaviorally based therapies. The fourth domain involves energy medicine, divided into veritable energies and putative energies. Veritable energies utilize vibrations such as sound, and electromagnetic forces such as light, magnetism, and radiation to treat patients. Putative energy therapies are the most controversial form of CAM, based upon the idea that human bodies contain energy and that therapists can positively affect this energy through therapies such as Reiki, Johrei, Qigong, healing touch, and intercessory prayer. NCCAM also reviews CAM systems not considered part of mainstream medicine in the United States but practiced as such elsewhere. These include traditional Chinese medicine that focuses on bodily disharmony and uses acupuncture, moxibustion, massage, and manipulation to achieve harmony and health. NCCAM performs these studies independently and also partners with governmental agencies and global scientific organizations. SEE ALSO: Alternative Medicine; National Institutes of
Health (NIH).
Bibliography. National Center for Complementary and
Alternative Medicine, http://nccam.nih.gov (cited July
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2007); Lorri A. Zipperer, ed., The Health Care Almanac: A Resource Guide to the Medical Field (American Medical Association, 1995). Kelly Boyer Sagert Independent Scholar
National Center for Environmental Health (NCEH) The National Center for Environmental Health (NCEH), which operates under the auspices of the Centers for Disease Control and Prevention (CDC), is committed to preventing illness, disability, and death caused by harmful interactions between humans and the environment, with special emphasis on vulnerable populations such as children, the elderly, and the disabled. This mission is accomplished by responding to emergencies as they occur, engaging in public education and training, and developing new environmental standards, guidelines, and policies. NCEH takes a life-span approach, beginning with the promotion of optimal fetal and child development and continuing throughout life. NCEH is located in the CDC compound at 1600 Clifton Road, Atlanta, Georgia 30333. General information on the organization is available by telephone (1-800-311-3435) or via the World Wide Web (http://www.cdc.gov/nceh/default.htm). NCEH was created at CDC in 1980 by combining the Environmental Health Services Division, the Bureau of State Services, the Chronic Disease Division, the Bureau of Epidemiology, the Clinical Chemistry Division, and the Bureau of Laboratory. Seven years later, the scope of the Center’s responsibility expanded to include nonoccupational injury control programs, and the name was changed to the Center for Environmental Health and Injury Control (CEHIC). In 1991, the name was again changed to mirror an expansion of activities, and the Center became the National Center for Environmental Health and Injury Control. The following year, the decision was made to divide the responsibilities for environmental health and injury prevention and control into two separate organizations, and the center resumed its identity as the NCEH.
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National Center for Health Marketing (NCHM) ing and technical assistance to state and local health agencies, and responds to public health challenges. From the beginning of its history, NCEH has been engaged in preventing environmental-related deaths. This mission has involved NCEH in a plethora of activities that began with leading the public health response to the eruption of Mount St. Helen’s in Washington state in 1980. Subsequently, NCEH investigated incidences of metabolic alkalosis among infants, which was traced to chloride-deficient infant formula. This finding led to the passage of the Infant Formula Act. Other activities included involvement in the campaign to remove lead from gasoline and collaboration with the National Weather Service to develop improved reporting methods for weatherrelated death and injuries. NCEH considers its major successes to be improving the lives of children through a campaign to focus national attention on lead poisoning and in developing guidelines to prevent spina bifida. SEE ALSO: Environmental Health; Environmental Medi-
cine; Environmental Protection Agency (EPA). NCEH led the public health response to the eruption of Mount St. Helen’s in Washington state in 1980.
To carry out its mission, NCEH partners with state and local health departments; federal, state, and local health and environment agencies; philanthropic foundations; industry and labor groups; professional, voluntary, and community organizations; and managed care organizations to protect the American public from environmental contaminants. Through the Global Health Office, NCEH cooperates with key individuals in other countries to promote the good health of all people. Other NCEH divisions include Emergency and Environmental Health Services, Environmental Hazards and Health Effects, and Laboratory Sciences. In practice, NCEH activities include conducting public health surveillance, applied research, epidemiologic studies, laboratory analyses, statistical analyses, behavioral interventions, and operations and systems research. NCEH also promotes communication and education, establishes standards and guidelines, makes recommendations, provides train-
Bibliography. Mark Allen Eisner, Governing the Envi-
ronment: The Transformation of Environmental Regulation (Lynne Rienner, 2007); Brent M. Haglund and Thomas Still, Hands-On Environmentalism (Encounter, 2005); Kenneth J. Meier and Laurence J. O’Toole Jr., Bureaucracy in a Democratic State: A Government Perspective (Johns Hopkins University Press, 2006); National Center for Environmental Health, http://www.cdc.gov/nceh/default. htm (cited July 2007); Robert Repetto, ed., Punctuated Equilibrium and the Dynamics of U.S. Environmental Policy (Yale University Press, 2006); Dennis D. Riley, et al., Bureaucracy and the Policy Process: Keeping the Promises (Rowman & Littlefield, 2006). Elizabeth R. Purdy, Ph.D. Independent Scholar
National Center for Health Marketing (NCHM) The National Center for Health Marketing (NCHM) was formed in 2004 to promote the health goals of the
National Center for Health Statistics (NCHS)
Centers for Disease Control and Prevention (CDC). To achieve that objective, the NCHM employs innovative, high-impact, and science-based marketing programs that focus on educating the American public on issues that impact their health. NCHM also partners with agencies and organizations within CDC and with other relevant agencies to further the influence of its marketing efforts. Health marketing combines practices from many disciplines, including traditional marketing, which creates and communicates information, and that uses the four fundamental elements of product (items or services provided), price (costs associated with the product), place (where the product can be found), and promotion (advertising and publicity campaigns). Health marketing also incorporates elements of social marketing, a discipline that aims to create social change through the use of commercial marketing techniques, and health promotion techniques gleaned from public health research and practice. The NCHM Web site provides this example of health marketing. Assume that the CDC has developed a new HIV/AIDS testing kit (product). This product is announced in both traditional media and medical journals (promotion), and free samples are sent to state health departments for distribution to public health and clinical health facilities through their state (place). Because CDC’s goal is to encourage the widespread use of this product, all of the samples distributed during this trial period are free (price). In health marketing, marketers must also consider the “price” paid by people using the new products, which might include their time to travel to the public health center. NCHM is currently marketing a number of CDC campaigns, including the Get Smart campaign: Know When Antibiotics Work; Brush Up on Healthy Teeth: Simple Steps for Kids Smiles; Choose Respect, an initiative to help teens learn healthy dating habits, to choose partners on the basis of mutual respect, and to avoid becoming involved in dating abuse situations; and Choose Your Cover, a skin cancer preventative program that teaches youth about sun protection techniques. Still other NCHM campaigns focus on its SNAP (School Network for Absenteeism Prevention) initiation, which shares information with middle school students about clean hands preventing illnesses; and
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the National Bone Health campaign, with its motto of “Powerful Bones, Powerful Girls,” and its educational message focusing on optimal bone health programs for girls aged 9 through 12. Although NCHM uses traditional media to spread its message, new media is an important component in its marketing plan, as the interactive nature of internet-based communication provides an effective way of disseminating information. New media used include online press releases and announcements, carefully targeted blogs and eGames, podcasts and videocasts, and RSS feeds. The NCHM is spreading information about seasonal influenza vaccinations, among other health-related topics, through these types of new media outlets. NCHM also partners with the writers and producers of movies and television shows, as well as music producers, to find venues to share health-related messages. SEE ALSO: Centers for Disease Control and Prevention
(CDC).
Bibliography. National Center for Health Marketing,
http://www.cdc.gov/healthmarketing/ (cited July 2007); Lorri A. Zipperer, ed., The Health Care Almanac: A Resource Guide to the Medical Field (American Medical Association, 1995).
Kelly Boyer Sagert Independent Scholar
National Center for Health Statistics (NCHS) The National Center for Health Statistics (NCHS) serves as the primary health statistical agency in the United States. This agency collects health-related information from multiple sources, including other government agencies; analyzes collective data; and then distributes research results to government officials, health care professionals and the general public. NCHS provides this health-related statistical information largely to assist in the planning, administering and modifying of national policies and programs that affect the health of people living in America.
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National Center for HIV, STD, and TB Prevention (NCHSTP)
The NCHS gathers information from sources such as governmental and health agencies; birth and death records; medical records; national surveys; personal interviews; physical exams and laboratory test results. NCHS must document the reliability of data sources and use the most accurate collection and measurement methods. The agency must maintain the highest level of confidentiality as possible. After compiling national health statistics, NCHS uses research results to monitor the health of Americans, overall, as well as in targeted demographics. They examine differences in health condition and health care use by race/ethnicity, socio-economic status, geographic factors and other group statistics. NCHS studies the interaction between the population and the national health care system to monitor health trends and report upon the effectiveness of health care delivery. statistics NCHS provides public access to broad statistical information including statistics on births and deaths; the condition of health and use of health care services by those living in America; plus information about data collection and research methodologies. NCHS also distributes information on specific health related topics. These include, among others, asthma, births/natality, child and infant health, deaths/mortality, diabetes, disabilities/impairments, divorces, health insurance, heart disease, home health/hospice care, hospital utilization, hypertension, immunizations, influenza, leading causes of death, life expectancy, mammography/breast cancer, men’s health, nursing home care, occupational health, overweight prevalence, prenatal care, sexually transmitted diseases, smoking, teen pregnancy and women’s health issues. They provide publications such as the “Healthy People 2010” series, as well as reports, brochures and pamphlets. They provide a significant amount of information on their web site, http://www.cdc.gov, including news releases, relevant listservs and email contacts. Other methods of distributing information include CD ROMS, automated voice and fax systems, hotlines and clearinghouses. Agency representatives give speeches, offer commentary for broadcast use, and for audiotapes, videotapes and video casting. Significant initiatives of the NCHS include Healthy People 2010. This initiative contains 467 ob-
jectives with the overall goal of improving the health of all people in the United States, both in quantity of years and quality of life. Moreover, the goal is to reduce and eventually eliminate health disparities among populations. The NCHS, located in Hyattsville, Maryland, is a division of the Center for Disease Control and Prevention (CDC), under the umbrella of the United States Department of Health and Human Services and as part of the Interagency Council on Statistical Policy (ICSP). SEE ALSO: Centers for Disease Control and Prevention
(CDC).
Bibliography. National Center for Health Statistics web
site, http://www.cdc.gov (cited July 2007); “Guidelines for Ensuring the Quality of Information Disseminated to the Public Centers for Disease Control: National Center for Health Statistics,” United States Department of Health and Human Services web site (http://aspe.hhs.gov/infoquality/ Guidelines/nchs.shtml (cited July 2007). Kelly Boyer Sagert Independent Scholar
National Center for HIV, STD, and TB Prevention (NCHSTP) The National Center for HIV, STD, and TB Prevention (NCHSTP) is based at the Centers for Disease Control and Prevention in Atlanta, Georgia, a branch of the United States government’s Department of Health and Human Services. Its budget comes from the Congressional Annual Budget Allocations. The Center works in conjunction with local, state, and national governmental and non-governmental organizations, including state and local public health departments that actually collect and report disease surveillance data. The Center’s stated mission is to provide surveillance data and research on HIV, other sexually transmitted infections, and tuberculosis for the United States, as well as providing technical assistance in the development of prevention programs. Other sexually-transmitted infections, or infections with a potential link to a sexually transmitted
National Center for Infectious Diseases (NCID)
infection, include chlamydia, syphilis, gonorrhea, viral hepatitis, bacterial vaginosis, genital herpes, human papilloma virus, pelvic inflammatory disease, and trichomoniasis. The Center provides extensive fact sheets for use by local public health educators, and coordinates national responses to infectious disease epidemics, particularly among high risk populations such as men who have sex with men, substance abusers, perinatal transmission among HIV positive women, correctional facility inmates, and immigrant populations, among others. A new concern is the increasing role in methamphetamine use in promoting HIV and other sexually transmitted infections. resource for professionals The Center also provides resources for health professionals treating those affected by HIV, TB, and other sexually transmitted diseases, such as treatment guidelines, research that can assist clinicians in identifying high-risk patients, and scientific information on emerging diseases. In particular, the Center is attempting to stem the recent increase of drug-resistant tuberculosis cases in the United States by encouraging proper and complete treatment regimes. The NCHSTP strongly advocates widespread HIV counseling and testing, implementing in 2006 its recommendation for a switch from ‘opt-in’ testing, whereby individuals are tested for HIV only after specifically requesting a test, to ‘opt-out’ testing, whereby all individuals aged 13 to 64 are tested for HIV in any healthcare setting unless they specifically request not to be tested. Furthermore, a special consent form would no longer be necessary, a move applauded by some HIV testing advocates. SEE ALSO: AIDS; AIDS—Living with AIDS; Sexually
Transmitted Diseases; Tuberculosis.
Bibliography. National Center for HIV, STD, and TB
Prevention web site, http://www.cdc.gov/nchhstp/ (cited July 2007); Gary Wormser, AIDS and Other Manifestations of HIV Infection (Academic Press, 2004); Lorri A. Zipperer, ed., The Health Care Almanac: A Resource Guide to the Medical Field (American Medical Association, 1995). Annie Dude University of Chicago
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National Center for Infectious Diseases (NCID) The National Center for Infectious Diseases is headquartered in Atlanta, Georgia. The NCID is one of 12 centers within the Centers for Disease Control and Prevention (CDC) whose parent organization is the Department of Health and Human Services. The NCID focuses on national and global prevention of illness, disability, and death from infectious diseases. A priority focus area for public health protection and prevention includes the identification of new, reemerging, and drug-resistant infectious diseases because of the widespread use of antibiotics around the world. Some circumstances provide additional susceptibility or risk for persons to contract an infectious disease or come in contact with an infectious disease. Special persons of interest include hospitalized patients (preventing nosocomial infections), pregnant women, infants and children, travelers and refugees, and those with immunocompromised status and chronic disease. Public safety from infectious disease is not limited to medical supports and research. The NCID also focuses on infectious disease spread by animal or arthropod vectors and food-borne, water-borne, and tropical and Arctic environments. With a goal of prevention, the NCID investigates epidemics, monitors reportable diseases, and performs research and surveillance to identify new or reemerging infectious diseases. These tasks are accomplished by forming working relationships with various professional and public entities including medical, regulatory, and academic professionals in public health, professional associations, clinical practice, and service organizations at the local, state, federal, and international levels. In addition to the offices under the Office of the Director, divisions and programs within the NCID specialize in different aspects of infectious disease. The list of specialties includes Arctic investigations, Bioterrorism preparedness and response, global migration and quarantine, healthcare quality promotion, parasitic diseases, scientific resources, vector-borne infectious diseases, viral hepatitis, and viral and rickettsial diseases.
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National Center for Injury Prevention and Control (NCIPC)
With the substantial scope of activities to protect the public from infectious diseases, a board of scientific counselors provides expertise in an advisory capacity. The board includes 21 voting members from the United States and encourages nonvoting membership representatives from Canada and Mexico. According to the NCID, the board meets in public session twice a year. Their contributions have improved emergency response capabilities, strengthened cooperation among the various professional and public entities, and continued research and implementation of procedures to detect and control infectious diseases. To disseminate information to both professionals and the public, the NCID publishes the bimonthly Emerging Infectious Diseases Journal and maintains a Web site with a searchable database. This site includes a special section for teachers and a resource section for students. The NCID sponsors, supports, and provides grant funding for diverse research including development of vaccines, antibiotics, and antivirals; studying bacterial resistance; epidemiology; and how to prevent the spread of infectious disease. SEE ALSO: Centers for Disease Control and Preven-
tion (CDC); Department of Health and Human Services (DHHS); Infectious Diseases (General).
“NCID Organization,” www.cdc.gov/ ncidod/about.htm (cited July 2007); “Priority Prevention Areas,” www.cdc.gov/ncidod/about.htm (cited July 2007); “Board,” www.cdc.gov/ncidod/about.htm (cited July 2007). Bibliography.
Lyn Michaud Independent Scholar
National Center for Injury Prevention and Control (NCIPC) The mission of the National Center for Injury Prevention and Control (NCIPC) is to remove injuries as the leading cause of death among Americans under the age of 30 and as one of the top 10 killers for Americans of all ages. NCIPC operates under the auspices of the Centers for Disease Control and Pre-
vention (CDC) and is located at 1600 Clifton Road, Atlanta, Georgia 30333. General information on the organization is available by telephone (1-800-3113435) or via the World Wide Web (http://www.cdc. gov/ncipc/). NCIPC is headed by a director, who is supported by a deputy director and five associate directors: Science, Extramural Research, Communication Science, Program Management and Operations, and Policy, Planning, and Evaluation. Other programs integral to NCIPC’s mission are the Office of Statistics and Programming, the Division of Unintentional Injury Prevention, the Division of Injury Response, and the Division of Violence Prevention. Home and recreational injuries became an area of concern to CDC in the early 1970s. By 1983, CDC was also involved in the study and prevention of violent deaths. In 1987, nonoccupational injury prevention and control became the responsibility of the Center for Environmental Health, and the agency’s name was changed to the Center for Environmental Health and Injury Control (CHIC). Five years later, responsibilities again shifted, and NCIPC was created as a separate agency. NCIPC’s major successes have included helping to reduce motor vehicle–related deaths and reducing fire-related deaths through the promotion of smoke alarms and fire safety education. NCIPC has also sought to reduce death and injuries among young people through studies on youth violence and by training local communities on measures that can be instituted to prevent these unnecessary deaths. Despite significant gains, the Center reports that between 1900 and 2000, accidental deaths in the United States rose from the seventh leading cause of death to the fifth leading cause of death. Among all individuals between the ages of 15 and 24, homicide continues to be the second leading cause of death. For AfricanAmerican males in that age group, homicide is the leading cause of death. Suicides are occurring in the United States at roughly the same rate as at the turn of the 20th century. In 2000, 148,000 people died from injuries in the United States. Most of those deaths occurred in motor vehicle crashes (43,354). The remainder were caused by suicides (29,350), homicides (16,765), unintentional falls (13,322), unintentional poisonings (12,757), unintentional drowning (3,482), and fires (3,377). Because injuries pose a substantial threat
National Center for Public Health Informatics (NCPHI)
to American lives and health, the overall focus of NCIPC activities is on alcohol-related injuries, bicycle-related injuries, child abuse and neglect, child passenger safety, dog bite injuries, falls among older adults, intimate partner violence, motor vehicle accidents, older adult drivers, pedestrian injuries, playground safety, poison control, residential fires, school violence, sexual violence, spinal cord injury, suicide, teen drivers, trauma care systems, traumatic brain injury, water-related injuries, and youth violence. Injuries not only cause unnecessary deaths and threaten the quality of life, but they also exact a heavy financial burden. Controlling for inflation, studies of injuries in 1988 suggest that injuries cost nearly $260 billion. While private sources accounted for 72 percent of injury-related medical expenses, the government covered the remaining 28 percent through Medicare and Medicaid benefits. According to 1985 estimates, the government spent $14.2 billion on injury-related disability and survivor benefits through the Social Security Disability Insurance, Supplemental Security Income, and the Veterans Administration programs. By 2000, the cost of injury-related medical treatment had risen to $406 billion, including $326 billion in productivity loss. Seventy percent of those costs were attributed to males. SEE ALSO: Centers for Disease Control and Prevention
(CDC).
Bibliography. Andrea Carlson, et al., Injury and Violence
Prevention: Behavioral Science Theories, Methods, and Applications (Jossey-Bass, 2006); Centers for Disease Control and Prevention, Injury Fact Book 2001–2002 (Centers for Disease Control and Prevention, 2001); CDC Injury Research Agenda (Department of Health and Human Services, et al., 2002); Kenneth J. Meier and Laurence J. O’Toole Jr., Bureaucracy in a Democratic State: A Government Perspective (Johns Hopkins University Press, 2006); National Center for Injury Prevention and Control, http://www.cdc. gov/ncipc/; Robert Repetto, ed., Punctuated Equilibrium and the Dynamics of U.S. Environmental Policy (Yale University Press, 2006); Dennis D. Riley, et al., Bureaucracy and the Policy Process: Keeping the Promises (Rowman & Littlefield, 2006). Elizabeth R. Purdy, Ph.D. Independent Scholar
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National Center for Public Health Informatics (NCPHI) The National Center for Public Health Informatics (NCPHI) is the division of the Center for Disease Control and Prevention (CDC) agency that helps public health agencies to create integrated data systems for a national exchange of public health information. The NCPHI mission is to advance computer and information technology in the health field so that public health organizations on local, state and federal levels can use innovative cutting-edge technology to turn large volumes of data from multiple sources into information that can help formulate timely public health care solutions. The CDC formed the NCPHI in 2005, combining all public health-related informatics divisions within this new organization; the impetus for its creation was a need to deal with bioterrorism threats and world-wide epidemics. Although clinical health care informatics is a fairly well developed discipline, the CDC noted that informatics with a distinct public health care focus was lagging. NCPHI was therefore charged with raising awareness of the need for public health informatics and linking the research and efforts of clinical health care and public health endeavors. Future goals include the creation of national standards for data integration; providing in-house consultations, trainings and strategic guidance for public health agencies; and assisting in public health informatics fundraising. NCPHI is located in Atlanta, Georgia within the Coordinating Center for Health Information and Service (CoCHIS). The agency consists of five divisions: The Division of Alliance Management and Consultation, The Division of Emergency Preparedness and Response, The Division of Shared Services, The Division of Integrated Surveillance Systems and Services, and The Division of Knowledge Management. The Division of Alliance Management and Consultation focuses on creating relevant alliances within the CDC and among other health care entities to further the goals and benefits of public health informatics. The Division of Emergency Preparedness and Response studies the emergency preparedness levels of public health systems. They monitor and advise agencies on their abilities to continue efforts during outbreaks of disease and other public health crises and
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National Center on Birth Defects and Developmental Disabilities (NCBDDD)
work with them to upgrade their access to pertinent national information. The Division of Shared Services searches for collaborative possibilities within CDC and among public health agencies in the United States. They are charged with identifying opportunities and the technical requirements that must be fulfilled for a collaboration to occur. The Division of Integrated Surveillance Systems and Services identifies informatics-based solutions for integrated public health surveillance, lab reporting and public health inventory management. The Division of Knowledge Management focuses on creating efficient methods to develop and share public health information. To further foster the development of public health information systems, NCPHI offers a grants program that provides funding for groundbreaking public health informatics research at major universities. NCPHI also provides public health informatics training on the innovative and future-driven technologies currently in development. SEE ALSO: Centers for Disease Control and Prevention
(CDC); Public Health.
Bibliography. National Center for Public Health Infor-
matics website http://www.cdc.gov/ncphi/ (cited July 2007); “Public Health Smartens Up” by Heather B. Hayes, Government Health IT, October 9, 2006 http://www.govhealthit. com/article96350-10-09-06-Print (cited July 2007). Kelly Boyer Sagert Independent Scholar
National Center on Birth Defects and Developmental Disabilities (NCBDDD) The National Center on Birth Defects and Developmental Disabilities (NCBDDD) is a division of the Center for Disease Control and Prevention (CDC) agency that works toward identifying causes of and preventing birth defects and developmental disabilities. They assist children born with birth defects and
disabilities to attain full potential and advocate for the health and physical well-being of all 54 million Americans with disabilities, regardless of age. According to the NCBDDD, birth defects serve as the leading cause of infant deaths, the impetus for more than 20 percent of all infant mortality. One in every 33 babies born in the United States is affected by birth defects; those that survive tend to become ill more often than the norm and they more frequently suffer from long term disabilities. Since 1967, CDC has closely monitored birth defects, watching for frequency variations. After Congress passed the Birth Defects Prevention Act of 1998, CDC was charged with gathering, evaluating, and distributing birth defect data. They began managing regional centers focusing on birth defect prevention research and disseminating information to the general public. On October 17, 2000, the Children’s Health Act of 2000 was signed into law; in response to the act’s requirements, the CDC established the NCBDDD on April 12, 2001 to promote optimal fetal, infant and child development. The agency partners with other United States agencies and globally to collaborate on birth defect prevention strategies. Through a collaborative effort between the United States and China, researchers discovered that increased folic acid before pregnancy and in early stages of pregnancy lowers the risk of neural tube defects such as spina bifida and anencephaly. Developmental disabilities are significant, persistent health conditions resulting from mental and/or physical impairments. Developmentally disabled individuals are challenged by crucial life activities involving language, mobility, learning, self-help and independent living. Developmental disabilities can begin anywhere from birth to 22 years of age and usually persist through a person’s lifespan. NCBDDD studies common developmental disability factors and determines likely candidates; pinpoints causes and factors that increase the likelihood that an individual will have developmental disabilities; and, finds ways for people with developmental disabilities to improve quality of life. NCBDDD/ CDC’s developmental disability activities focus on autism spectrum disorders, cerebral palsy, hearing loss, mental retardation and vision impairment. Their hereditary blood disorders team partners with health care providers, educators, community
National Cholesterol Education Program (NCEP)
organizations and national and international health prevention agencies to implement prevention programs for blood disorders. The team has four goals: preventing infectious disease transmission to persons receiving blood products; identification of risk factors and the reduction of blood disorder complications; prevention and reduction of bleeding and clotting disorder complications affecting women’s health; and the development and dissemination of prevention education to enable affected persons to make informed health care decisions. SEE ALSO: Birth Defects; Center for Disease Control and
Prevention (CDC).
Bibliography. National Center on Birth Defects and De-
velopmental Disabilities (NCBDDD) web site, http://www. cdc.gov/ncbddd/ (cited July 2007); Rosemarie Sweeney and Matthew Neff, “CDC Establishes New Center on Birth Defects and Disabilities: National Center on Birth Defects and Developmental Disabilities,” American Family Physician (v.63/11, 2001).
Kelly Boyer Sagert Independent Scholar
National Cholesterol Education Program (NCEP) The National Cholesterol Education Program (NCEP) was founded by the National Heart, Lung, and Blood Institute (NHLBI) in November 1985 for a very specific purpose. This agency focuses on increasing the awareness of the dangers of high blood cholesterol and the benefits of lowering blood cholesterol in an effort to reduce the incidences of illness and death caused by coronary disease in the United States. NCEP cites national survey results to validate their progress toward increasing knowledge in the medical community and in the general public about the dangers of high blood cholesterol; and toward reducing the prevalence of high blood cholesterol in people living in the United States. They list surveys of physicians and the public that show the percentage of people checking their blood cholesterol rising from 35 percent to 75 percent between 1983 and 1995, an increase
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of 70 to 80 million Americans; meanwhile, cholesterol levels of 240 or above declined from 26 percent to 19 percent. NCEP also points to a corresponding decline in coronary disease fatalities that they correlate with their educational campaign. NCEP’s current strategy promotes the detection and treatment of elevated blood cholesterol levels. It also includes a call to Americans to reduce saturated fat and cholesterol intake while increasing exercise and managing body weight. Since its inception, the NCEP has collaborated with relevant organizations to promote national implementation of its strategies and guidelines. The NCEP Coordinating Committee, which consists of representatives from health professional associations, volunteer groups, community programs and governmental agencies, helps disseminate cholesterol data to the population. The coordinating committee also sponsors expert panels to create guidelines for health professionals. They include the Expert Panel on Detection, Evaluation and Treatment of High Blood Cholesterol in Adults; the Laboratory Standardization Panel; the Expert Panel on Population Strategies for Blood Cholesterol Reduction; the Expert Panel on Blood Cholesterol Levels in Children and Adolescents; and the Working Group on Lipoprotein Management. To reduce coronary diseases by reducing the prevalence of elevated blood cholesterol, NCEP focuses on three main educational methods. The first method involves educating health professionals on the cause of coronary disease, and to increase their awareness of the importance of weight control, diet and exercise in lowering blood cholesterol. The second method involves educating the public to increase awareness that elevated blood cholesterol is a significant cause of coronary disease. This process involves encouraging the reduction of cholesterol and saturated fat intake, increasing the number of Americans who regularly monitor their blood cholesterol levels, and spreading the knowledge that diet and exercise also contribute to the management of high blood cholesterol. The third method focuses on encouraging the community to increase blood cholesterol control activities, educating children on blood cholesterol and cardiovascular risk factors, creating program activities specifically geared toward minorities and other target demographics and promoting increased
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National Coalition for Cancer Survivorship (NCCS)
dissemination of scientifically accurate cholesterolrelated information. SEE ALSO: Cholesterol; Coronary Disease, National Heart,
Lung, and Blood Institute (NHLBI).
Bibliography. National Cholesterol Education Program
(NCEP) website, http://www.nhlbi.nih.gov/about/ncep/ index.htm (cited July 2007); Rosemary Sweeney and Matthew Neff, “New Cholesterol Guidelines (National Cholesterol Education Program),” American Family Physician (v.64/1, 2001). Kelly Boyer Sagert Independent Scholar
National Coalition for Cancer Survivorship (NCCS) In 1986, the National Coalition for Cancer Survivorship (NCCS) was founded by twenty-three nationally recognized leaders in cancer care, research, support and advocacy to demand quality cancer care for all. Although other cancer research groups were founded before NCCS, this organization is the first one to focus on the need for fully informed cancer patients and that strives to empower cancer survivors. NCCS transformed language used to refer to people with cancer. The NCCS charter states that “from the moment of diagnosis and for the balance of life, an individual diagnosed with cancer is a survivor.” This concept of “cancer survivor” is now nearly universally recognized and accepted. In 1993, NCCS founded the Cancer Leadership Council (CLC), a national council of advocacy organizations focusing on cancer-related issues of public policy. The NCCS initially assembled eight established cancer advocacy groups; by 2005, there were 31 advocacy groups under NCCS. In 1995, NCCS hosted the First National Congress on Cancer Survivorship. The delegation was comprised of over 300 cancer experts including survivors, caregivers, medical professionals, scientists, community leaders, policy experts, legislators, government officials, clergymen and members of the media. In 1996, NCCS published the Imperatives for Quality
Cancer Care and Access, Advocacy, Action & Accountability, which is the first report on quality cancer care as seen through the eyes of the patient. On an episode of Larry King Live (CNN) in 1998, NCCS launched a new public awareness campaign with a plea for increased cancer research funding. In response, on September 25-26, 1998, The National Mall in Washington, DC was flooded with 250,000 people who were participating in the Coming Together to Conquer Cancer march. Simultaneously, in each of the 50 states, 1 million more people participated in 200 events across the nation with appeals for increased cancer funding. In 2004, NCCS launched Cancer Advocacy Now!, a network focused on public cancer policies. In 2005, distribution of the Cancer Survival Toolbox to cancer survivors and cancer centers in all 50 states, the District of Columbia and Puerto Rico surpassed 500,000. This audio program focuses on six topics: communication, discovering information, decision making, problem solving, negotiating, and standing up for one’s rights. Some information focuses specifically on older people, while other sections discuss ways to pay for cancer care, caring for the caregiver, and life beyond cancer. Also in 2005, it was reported that more than 10 million people were living with cancer up from the estimated 3 million in 1971. People with cancer, the report concluded, were clearly living longer, but were not receiving enough quality follow up care. The 2005 NCCS annual report states their organization has made such an enormous impact on the language surrounding cancer and on the idea that people with cancer are survivors that an Office of Cancer Survivorship (OCS) has been established. SEE ALSO: American Cancer Society (ACS); Cancer—
Coping with Cancer; National Cancer Institute (NCI).
Bibliography. National Coalition for Cancer Survivor-
ship (NCCS) website, www.canceradvocacy.org/ (cited July 2007); “Cancer Survivors Urged to Take Action for Better Health Care,” PR Newswire, November 7, 2005, www.ovarian-news.org/nccs_urge.html (cited July 2007). Kelly Boyer Sagert Independent Scholar
National Eye Institute (NEI)
National Environmental Health Association (NEHA) The National Environmental Health Association (NEHA) was created in 1937 in California to establish standards for environmental health professionals. The environmental health field was still in its infancy stages and founders of the NEHA believed that these standards were needed to legitimize the profession. Obtaining these credentials indicated that a person had gained the skills and knowledge necessary to perform environmental health duties. Today, NEHA continues to advocate for the education of environmental health professionals, believing that the educated and motivated professional will work harder to provide a healthful environment for all. NEHA currently offers eight credential programs, expanded from the original one, with a ninth program in development stages. Each of the programs offers an educational component and a motivational one. The Registered Environmental Health Specialist / Registered Sanitarian (REHS / RS) program teaches professionals how to train personnel to respond to either routine or emergency environmental situations. People with REHS / RS certifications can also educate the community on environmental issues. The Certified Food Safety Professional (CFSP) focuses on the safety of food. The Certified Environmental Health Technician (CEHT) can provide environmental testing and sampling services and works to eliminate environmental health hazards. The Registered Environmental Technician (RET) is certified in baseline hazardous materials handling, while the Registered Hazardous Substances Professional (RHSP) and the Registered Hazardous Substances Specialist (RHSS) obtain more extensive training in hazardous materials handling. NEHA currently offers two different National Radon Proficiency Programs (NRPP) and will soon begin a credentials program for onsite wastewater system installers. NEHA also produces an Annual Educational Conference (AEC) & Exhibition, and provides numerous yearly technical workshops. Additionally, NEHA publishes the Journal of Environmental Health, which has subscribers in more than forty countries and that addresses issues such as air quality, drinking water, food safety and protection, hazardous materials/toxic
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substances management, institutional environmental health, occupational safety and health, terrorism and all-hazards preparedness, vector control, wastewater management, and water pollution control/water quality. While the majority of NEHA’s 4,500 members are employed by state and county health departments, many members are employed in the public and private sectors as well as in academia. NEHA staff and members collaborate with one another, as well as with other health organizations and relevant governmental entities. Members have the opportunity to serve on the following committees: Air/Land; Children’s Environmental Health; Drinking Water Quality/Water Pollution; Emerging Pathogens/Vector Control and Zoonotic Diseases; Environmental Health Leadership Development; Environmental Health Research; Food Safety and Protection; General Environmental Health; Hazardous Materials and Toxic Substances; Injury Prevention/Occupational Health; Institutions and Schools Environmental Health; Onsite Wastewater Systems; and Terrorism and All-Hazards Preparedness. Although NEHA emphasis is frequently on the technical aspects of environmental health, NEHA also provides guidance to members as they work with the legal, political and economic situations in the United States, and as they attempt to balance environmental concerns with realities that surround them. SEE ALSO: Environmental Health; Environmental Medi-
cine.
Bibliography. Journal of Environmental Health, http://
www.neha.org/JEH (cited July 2007); The National Environmental Health Association (NEHA) web site, http:// www.neha.org (cited July 2007); “Credentialing through NEHA: What It Is and Why You Should See It,” Journal of Environmental Health (v.68/7, 2006). Kelly Boyer Sagert Independent Scholar
National Eye Institute (NEI) The National Eye Institute (NEI) is one of twentyseven United States National Institutes of Health
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National Eye Institute (NEI)
(NIH) established by Congress; the NEI was created by Public Law 90-489 in 1968. It was formed to protect and prolong the vision of people living in the United States by preventing, diagnosing and treating eye diseases and conditions, NEI’s April 1975 report, Vision Research Program Planning, was perhaps the country’s first comprehensive vision assessment. NEI has continued to oversee innovative research on visual disorders and diseases, with the overriding goal being the reduction in vision impairment. NEI also provides relevant training and dissemination of research results and, in 1991, the institute collaborated with more than 60 professional organizations and governmental agencies to create the National Eye Health Education Program (NEHEP). NEI vision research is supported through approximately 1600 research grants and training awards bestowed upon scientists at more than 250 medical centers, hospitals, universities, and other institutions worldwide. Research is focused on six key areas: retinal diseases; corneal diseases; lens and cataract; glaucoma and optic neuropathies; strabismus, amblyopia, and visual processing; and low vision and blindness rehabilitation. At its facilities located on the Bethesda, Maryland NIH campus, NEI also conducts research. Results have created significant strides in the treatment of multiple potentially blinding diseases, including
diabetic retinopathy, amblyopia, age-related macular degeneration (AMD), glaucoma, retinopathy of prematurity, corneal stromal keratitis, cytomegalovirus (CMV) retinitis, uveitis, retinitis pigmentosa, Leber’s congenital amaurosis, lasers for treatment of AMD, glaucoma, and myopia (nearsightedness). Current areas of NEI cutting edge research include the transplantation of healthy cells into diseased retinas, exploring gene-based treatments to slow some forms of retinal degeneration and the development of “neuroprotection” strategies to prevent or slow glaucoma cell damage. NEI has continually updated its original strategic plan, to factor in the latest scientific advancements, and its most recent overhaul contains two major strategic components. The first phase of the process involves assessments of progress made towards NEI goals. Upon completion of this assessment, the experts will select verify essential research areas and develop goals to concentrate on them. The second phase includes a round of workshops and conferences focused on emerging areas of science to determine how they might be applied to eye diseases and vision disorders. For the first time, Healthy People 2010, a United States Department of Health and Human Services initiative, includes a visual component and NEI is serving as the agency to assist in achieving healthy vi-
The National Eye Institute (NEI) is one of 27 United States National Institutes of Health (NIH) established by Congress. It was created in 1968 to protect and prolong the vision of people living in the United States
National Heart, Lung and Blood Institute (NHLBI)
sion. Key goals include the establishment of regular eye exams for all Americans; vision screening starting as early as preschool age; visual impairment correction and the prevention of eye injuries. Approximately 6 percent of Americans, or 14 million people, have vision impairments; 11 million of them have not received assistance in correcting these issues. NEI therefore recommends an increase in educational effort by health care professionals to encourage regular check ups and to increase screening opportunities for the general public. SEE ALSO: Eye Care; National Institutes of Health (NIH). Bibliography. National Eye Institute web site, http://
www.nei.nih.gov (cited July 2007); “National Eye Institute” by Erin E. Dooley, Environmental Health Perspectives, (v.113/12, 2005). Kelly Boyer Sagert Independent Scholar
National Heart, Lung and Blood Institute (NHLBI) The National Heart, Lung and Blood Institute (NHLBI) is one of twenty-seven National Institutes of Health (NIH) established by Congress. This organization was initially created in June 1948 through efforts of the scientific councils of the American Heart Association and originally named the National Heart Institute (NHI). In 1969, the NHI became the National Heart and Lung Institute and, in 1976, the NHLBI. The goals of NHLBI are to prevent, diagnose, treat and cure heart, blood vessel, lung and blood diseases, and sleep disorders, while also providing a safe, ample national blood supply. Since 1997, NHLBI has administered the NIH Women’s Initiative, as well. NHLBI funnels significant resources toward research in a quest to prevent, detect, treat and cure diseases of the heart, blood vessels, lungs and blood, as well as sleep disorders. This research occurs in the NHLBI laboratories; the organization also offers grants to individuals and organizations conducting relevant research. NHLBI also focuses research ef-
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forts toward quality blood resource management. Since establishing the Inclusion of Minorities and Women in Research initiative in 1991, NHLBI has strengthened its focus on eliminating health disparities in minority populations. They have committed research funds to address diseases more prevalent in minority populations, including high blood pressure, coronary disease, obesity, physical inactivity, diabetes, asthma, sarcoidosis, tuberculosis, sickle cell anemia and Cooley’s anemia. NHLBI provides educational materials on their focus topics for medical professionals, researchers and the general public. They also offer training and career development for new and established researchers. One of the newest areas of research is cell-based therapies for heart, lung and blood diseases; in September 2006, NHLBI awarded its first three grants in that area of medical research. Other NHLBI-supported activities and collaborations include: National Cholesterol Education Program, National Heart Attack Alert Program, National High Blood Pressure Education Program, The Heart Truth Campaign for Women’s Heart Health, Action to Control Cardiovascular Risk in Diabetes (ACCORD), Bypass Angioplasty Revascularization Investigation in Type 2 Diabetics (BARI 2D), Family Blood Pressure Program, Framingham Heart Study, Girls Health Enrichment Multisite Studies (GEMS), Jackson Heart Study, Multi-Ethnic Study of Atherosclerosis (MESA), Sleep Heart Health Study, Trial of Activity for Adolescent Girls (TAAG), Pediatric Cardiovascular Clinical Research Network, Pediatric Circulatory Support Initiative, and the Home Automatic External Defibrillator Trial. Their website (http://www.nhlbi.nih.gov/health/ dci/index.html) contains a comprehensive list of medical conditions with significant information about the diseases, their risk factors, signs and symptoms, diagnoses and treatment options, and links to cutting edge research and therapies. The NHLBI Health Information Center accepts phone calls during regular business hours, providing medical information health conditions such as high blood pressure, high cholesterol, asthma and blood disorders. They provide medical professionals, researchers and the general public with print publications, online educational tutorials, news releases and links to more quality medical resources.
1180 National Human Genome Research Institute (NHGRI) SEE ALSO: National Institutes of Health (NIH); American
Heart Association (AHA); National Cholesterol Education Program (NCEP).
Bibliography. American Heart Association web page
(http://www.americanheart.org/presenter.jhtml?identifier =4762) (cited July 2007); National Heart, Lung and Blood Institute web site (http://www.nhlbi.nih.gov/) (cited July 2007); “NHLBI awards First Grants in New Cell-based Research Program for Heart, Lung and Blood Diseases,” Transplant News, http://www.highbeam.com/doc/1G1140973048.html (cited July 2007). Kelly Boyer Sagert Independent Scholar
National Human Genome Research Institute (NHGRI) In 1989, the National Human Genome Research Institute (NHGRI) began spearheading the National Institutes of Health (NIH) contribution to the Human Genome Project (HGP). The HGP was an international research effort to establish the chromosomal location of all human genes or, in other words, to map out the human genome. Once scientists and researchers completed this monumental task, their focus would switch to developing DNA-based strategies to determine the origins and genetic makeup of health and of disease and then use this knowledge to prevent, treat and cure disease. Countries participating in this global research initiative included the United States, coordinated by the NHGRI and the U.S. Department of Energy (DOE); the United Kingdom; France; Germany; Japan and China. To accomplish their goals, NHGRI provided funding to scientists at universities and private laboratories and, in 1993, NHGRI created the Division of Intramural Research to further their HGP pursuit. Through these international collaborations, researchers successfully sequenced all three billion human genome pairs, thus mapping out the entire human genome sequence by April 2003. This part of the project was completed ahead of schedule and under budget; NGHRI published the results and they are available to everyone. As part of this full disclosure,
NHGRI developed the ENCODE Project (ENCyclopedia Of DNA Elements), a public research association that can assess and evaluate DNA information. The ultimate goal of ENCODE is to identify functional parts of human genome and anyone meeting NHGRI criteria can participate. After the human genome mapping was essentially completed, NHGRI began concentrating efforts on determining the genomic role in health and disease. Experts anticipate that this information will greatly assist in the development of medical diagnostic tools and in the creation of more effective treatments for disease. Moreover, geneticists can use this information to more accurately predict risk factors for individuals. According to the Biotechnology Industry Organization, more than 350 biotech products are in developmental stages because of this genomic breakthrough. This information is also being used in the International HapMap Project to study human genetic variations and their ramifications on health and wellness. NHGRI is also involved in DNA sequence comparisons between humans and various other organisms. Pinpointing these differences will allow scientists to determine which genetic properties are uniquely human. NHGRI has also created a data analysis center, The Centers of Excellence in Genomic Science (CEGS), so that researchers can use cutting edge technologies to analyze results of global biomedical research. To address ethical, legal and social repercussions of the data, in 1990 NHGRI established the Ethical, Legal and Social Implications (ELSI) Research Program at NHGRI. Knowledge gained from the HGP and subsequent research, according to ELSI guidelines, will benefit society only if measures are taken to avoid misuse in the form of genetic-based discrimination, and privacy invasion by government agencies, employers or insurers. SEE ALSO: Gene Mapping; Genetics; Human Genome Or-
ganization (HUGO); National Institutes of Health (NIH).
Bibliography. Robin Buton and Alan Petersen, The New
Genetics and the Public’s Health (Routledge, 2002); Human Genome Project (HGP) web site, http://www.ornl.gov/sci/ techresources/Human_Genome (cited July 2007).
Kelly Boyer Sagert Independent Scholar
National Institute of Allergy and Infectious Diseases (NIAID)
National Immunization Program (NIP) The National Immunization Program (NIP) is a division of the Centers for Disease Control and Prevention (CDC) agency, located in Atlanta, Georgia. NIP takes the lead in planning, coordinating and conducting national immunization-related activities with the ultimate goal of eradiating vaccination-preventable diseases, disabilities and deaths for children and adults. NIP is divided into three divisions, with the first being the Epidemiology and Surveillance Division (ESD). This department provides the scientific information necessary to create safe and effective immunization programs. This division is broken down into two more specialized areas: the Bacterial Vaccine-Preventable Diseases Branch and the Viral Vaccine-Preventable Diseases Branch. The Immunization Services Division (ISD) is the support system for state and local public health departments and other locales with immunization programs. The division’s Assessment Branch monitors immunization programs, while the Education, Information and Partnership Branch provides training, develops collaborations, shares new technologies, formulates policies and procedures and creates educational materials. The Health Services Research and Evaluation Branch is the core research department, while the Program Operations Branch provides technical assistance to those giving immunizations. The Program Support Branch reviews vaccine contracts and negotiates for the purchase of vaccines. Finally, the Immunization Registry Support Branch assists health departments in creating and maintaining records and registries. By the time that an American child is two years old, there is more than a 20 percent chance that he or she has received healthcare services from more than one provider. The establishment of Immunization Information Systems will consolidate immunization records, helping to ensure that children receive the correct set of vaccinations The third division of NIP, the Global Immunization Division (GID), focuses on the eradication of polio, worldwide, and the reduction of measles. They also advocate for and support global immunization programs. One of the most well-known and frequently used NIP’s products is the childhood immunization sched-
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ule. This schedule gives a synopsis of childhood vaccine recommendations in table format. The schedule of routine childhood vaccinations is approved by the Advisory Committee on Immunization Practices (ACIP), the American Academy of Pediatrics (AAP), and the American Academy of Family Physicians (AAFP). To ensure the utmost effectiveness and safety in childhood immunizations, the schedule is under constant evaluation and NIP issues regularly updated bulletins. NIP also provides answers to frequently asked questions about vaccinations, defining terms such as “immunity” and “vaccine,” and explaining how antibodies form in response to immunizations to fight disease. Their Web site (www.cdc.gov/nip/webutil/terms/glossary.htm) also contains a comprehensive glossary of immunization-related terms. Another important role of NIP is to measure how many children and adults are vaccinated. Using this data, NIP can predict vaccination rates by income level, race, education of mother and other group factors. They use this data to determine who is at risk of preventable diseases and then focus educational programs towards those demographics. SEE ALSO: Centers for Disease Control and Prevention
(CDC); Immunization/Vaccination.
Bibliography. “A Blueprint for Sustained Success: Na-
tional Immunization Program Strategic Plan, 2000-2005,” National Immunization Program, http://www.cdc.gov/nip/ webutil/about/strategic-plan.pdf (cited July 2007); National Immunization Program website http://www.cdc.gov/nip/ default.htm (cited July 2007). Kelly Boyer Sagert Independent Scholar
National Institute of Allergy and Infectious Diseases (NIAID) Founded in 1948 and currently one of the twenty-seven National Institutes of Health (NIH) agencies established by Congress, the National Institute of Allergy and Infectious Diseases (NIAID) conducts research to
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National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS)
learn how to prevent and treat infectious diseases, as well as immunity-based disorders and allergies. More recent key foci include HIV/AIDS research and biodefense research. NIAID is divided into six divisions, each with its own scope of responsibilities. The Division of Acquired Immunodeficiency Syndrome (DAIDS), formed in 1986, concentrates on conducting HIV/AIDS research; shares information about the transmission of the virus; advises on prevention strategies and focuses on moving forward treatment options, include a vaccination. The Division of Allergy, Immunology and Transplantation (DAIT) focuses on immunity-based diseases, ranging from transplant rejections to allergies and autoimmune diseases, overseeing international research programs in this arena. The Division of Clinical Research (DCR) integrates NIAID research results from around the world, ensuring that all research meets compliance standards and uses appropriate methodologies. The Division of Extramural Activities (DEA) oversees grant and contract management, training and peer review programs. This division is also responsible for staff training and intranet communications. The Division of Intramural Research (DIR) focuses on laboratory and clinical research, largely in the area of infectious diseases and the operations of the immune system. The Division of Microbiology and Infectious Diseases (DMID) serves as the support division for all disease research except that involving AIDS/HIV. The Dale and Betty Bumpers Vaccine Research Center (VRC) works on formulating new vaccination strategies, particularly for AIDS. Since 2001, because of increased threats from terrorism and biological weapons, NIAID has broadened its scope, greatly accelerating its research in the field of biodefense. The agency focuses on diagnostic tests of potential threats, vaccines to protect Americans from these threats and therapies for those affected by a biological agent. In 2004, NIAID announced $232 million in contracts in vaccine developments for smallpox, plague and tularemia, three likely bioterrorism agents. To counteract potential biological weapons, NIAID uses a six-pronged approach. First, scientists determine how a particular organism causes disease and how the human immune system attempts to protect the body from the organism. Armed with this knowledge, they
work on potential vaccines and drugs that may protect people from the biological material. They also work on diagnostic techniques so that diseases caused by bioweapons can be quickly diagnosed and then treated. Finally, they are creating dedicated laboratories wherein scientists can focus on effective biodefense research. Another NIAID project of significance is the Influenza Genome Sequencing Project, wherein researchers attempt to determine the genomic (human genetic) basis of influenza. As scientists learn how flu viruses spread and cause disease, they will become significantly closer to finding effective ways to prevent and / or treat the disease. NIAID benefits from their multi-disciplined approach to health-related research. As just one example, in 2006, researchers investigating treatments for AIDS/ HIV unexpectedly discovered a potentially successful strategy for treating the deadliest form of skin cancer. SEE ALSO: AIDS; Allergy; Biodefense; Immunizations/
Vaccinations; National Institutes of Health (NIH).
Bibliography. National Institute of Allergy and In-
fectious Diseases, http://www3.niaid.nih.gov (cited July 2007).
Kelly Boyer Sagert Independent Scholar
National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS) For 20 years, the National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS) has been part of the National Institutes of Health (NIH). NIAMS’s mission is to mitigate the effects of diseases of the bones, joints, muscles, and skin and address the gender, racial, and ethnic disparities through treatment, strategies, policies, education, and research. NIAMS is located in NIH facilities at 1 AMS Circle, Bethesda, Maryland 20891. Information on the agency is available by telephone (1-800-877-22-NIAMS) or via the internet (http://www.niams.nih.gov/).
National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS)
Arthritis, musculoskeletal, or skin diseases affect virtually every household in the United States, regardless of age, race, ethnicity, and socioeconomic status. In addition to being disproportionately affected, women and minorities may experience these diseases to a greater degree than the rest of the population. Arthritis, musculoskeletal, or skin diseases are often chronic, leading to lives filled with pain, disability, and/or disfigurement. Billions of dollars are spent each year on treating them, and billions more are lost to reduced productivity. Lupus, an autoimmune disease that may attack the joints, skin, kidneys, heart, lungs, blood vessels, and brain of sufferers, is a major focus of NIAMS activity. Lupus tends to occur among women of childbearing age, and African-American women are three times more likely than white women to contract lupus and to die from lupus-related conditions. Research efforts are geared toward identifying the biological reasons that cause some ethnic groups to be more susceptible to lupus and explaining why they experience the disease with greater severity. Scleroderma, an autoimmune disease that leads to widespread hardening of the skin, is also a focus of NIAMS activity. Like lupus, scleroderma is more likely to attack women than men. Scleroderma may spread to the lungs, heart, kidneys, intestinal tract, muscles, and joints. In a minority of cases, it may be fatal. Research suggest that genetics and environment are the major causes of the disease, which is more prevalent among segments of the Native-American population than among the population as a whole. Working with groups such as the Scleroderma Foundation/United Scleroderma Foundation, NIAMS is attempting to identify all biological causes of scleroderma. Osteoarthritis, which is a degenerative joint disease that ranges from mild discomfort upon rising in the morning to progressive disability, is of great concern to NIAMS because it affects almost 21,000,000 Americans. Osteoarthritis may attack any joint, but it tends to concentrate in the knees, hips, spine, small joints of the fingers, the base of the thumb, and the big toe. Previous injuries and stress may be responsible for osteoarthritis in other joints. African Americans are more likely than other groups to experience osteoarthritis of the knees and hips. Some researchers have suggested a link between African-American prevalence and obesity, which is a major factor in os-
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teoarthritis. Despite a higher prevalence rate, even when controlling for age, sex, and insurance coverage, blacks are less likely than whites to have total knee replacement. Institute goals center on identifying biomarkers related to osteoarthritis and addressing treatment disparities among blacks and whites. A major focus of skin disease activity at NIAMS is on vitiligo, a condition that leads to a loss of pigment, creating social and psychological backlash for people of color. Among whites, vitiligo is associated with albinism. Because of the strong heredity link to vitiligo, studies concentrate on identifying genes that cause the disease and understanding how genes and proteins determine the course of the disease. NIAMS is also interested in the study of keloids in which excessive connective tissue growth occurs at wound sites. Research is centered on identifying genetic links to keloids and on developing methods of control. NIAMS is headed by a director, and research responsibilities are divided among the Extramural and Intramural Research Programs. Outreach programs include the Health Partnership Program, NIAMS Coalition Members, and the Pediatric Rheumatology Clinic. NIAMS has developed “Looking Good, Feeling Good” to teach sixth to eighth graders about bones, muscles, and skin physiology and health. The Institute has also adopted Wheaton High School in Maryland where NIAMS participates in the Bioscience and Medicine Academy. SEE ALSO: Arthritis; Lupus; National Institutes of Health
(NIH); Osteoarthritis; Scleroderma; Vitiligo.
Bibliography. Irwin M. Freedberg, et al., Fitzpatrick’s
Dermatology in General Medicine (McGraw-Hill, 2003); Nortin M. Hadler, Occupational Musculoskeletal Disorders (Raven, 1993); Gene G. Hunder, ed., Mayo Clinic on Arthritis (Mayo Clinic, 1999); Lisa Iannucci, The Unofficial Guide to Overcoming Arthritis (Macmillan, 1999); Donald Y. M. Leung and Malcolm W. Greaves, eds., Allergic Skin Disease: A Multidisciplinary Approach (Marcel Dekker, 2000); National Institute of Arthritis and Musculoskeletal and Skin Diseases, http://www.niams.nih.gov (cited July 2007); National Institutes of Health, Questions and Answers about Arthritis and Rheumatic Diseases (National Institute of Arthritis and Musculoskeletal and Skin Diseases, 2002); Allan Praemer, et al., Musculoskeletal Conditions in the United States (American Academy of Orthopedic Surgeons,
1184 National Institute of Biomedical Imaging and Bioengineering (NIBIB) 1992); Shaun Ruddy, et al., Kelly’s Textbook of Rheumatology (Saunders, 2001). Elizabeth R. Purdy, Ph.D. Independent Scholar
National Institute of Biomedical Imaging and Bioengineering (NIBIB) The National Institute of Biomedical Imaging and Bioengineering (NIBIB) became one of the 27 National Institutes of Health (NIH) in the United States when President Bill Clinton signed its creation into law in 2000. The NIBIB is dedicated to developing and accelerating biomedical solutions to prevent or treat a broad spectrum of injury and disease. Physicians, scientists, researchers, and engineers from multiple disciplines work to merge attributes of physical and biological sciences to create new technological tools to overcome health-related challenges. The three research-based divisions of NIBIB are Discovery Science and Technology (DDST), Applied Science and Technology (DAST), and Inter-Disciplinary Training, wherein career training is provided through high-level collaborations. DDST oversees bioengineering and biomedical imaging research programs, conducting work in a number of disciplines: drug and gene delivery, medical devices and implant sciences, tissue engineering, and so forth. DAST works to advance minimally invasive methods to improve human health, including imaging technology development, ultrasound, biosensors, and so forth. The NIBIB Intramural Research Program, named the Positron Emission Tomography (PET) Radiochemistry Group, is located on the NIH campus in Bethesda, Maryland. The main focus of this group is radiopharmaceutical development to conduct human imaging; the ultimate goal of this research is a better understanding of biochemical processes and the development of drugs to alleviate disease when these biochemical processes do not function optimally. Disease foci for these developments include neurological disorders and cancer. NIBIB research has also been used by the National Institute of Mental
Health in its work combating depression and Alzheimer’s disease. Training young researchers and scientists to tackle complex multidisciplinary work is another important part of the NIBIB mission. The agency develops educational programs in the biomedical and bioengineering fields, ensuring opportunities for minority populations to participate in the programs. Beginning in 2001, NIBIB collaborated with the Howard Hughes Medical Institute (HHMI) to provide start-up funds for graduate-level training programs that combine biomedical education with training in the physical sciences and engineering field. Biomedical imaging is valuable because physicians can now diagnose increasing numbers of diseases without using invasive procedures to do so. As this technology develops, physicians can spend less time diagnosing diseases, theoretically freeing up more time to focus on disease prevention. According to a NIBIB official, imaging allows scientists to see how the structure of the body and the function of the body interact. One recent breakthrough in research funded by NIBIB is a technology called multi-isotope imaging mass spectrometry (MIMS) which allows scientists to analyze and quantify individual molecules within mammal or bacteria cells. This technology allows researchers to capture images of subcellular processes that undergird human disease and may be particularly useful when studying autoimmune or metabolic diseases. The NIBIB Web site (http://www.nibib.nih.gov/ HealthEdu/ResourceLibrary) contains a resource library with an extensive amount of links suitable for researchers and the general public. SEE ALSO: National Institutes of Health (NIH). Bibliography. Mike May, “Biomedical Imaging Put to
Work: Imaging Is the Interface to View the Human Machine,” Advanced Imaging (September 1, 2005), “Biomedical Imaging Put to Work,” HighBeam Research, http:// www.highbeam.com/doc/1G1-137624270.html (cited July 2007); National Institute of Biomedical Imaging and Bioengineering, http://www.nibib.nih.gov. Kelly Boyer Sagert Independent Scholar
National Institute of Child Health and Human Development (NICHD)
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National Institute of Child Health and Human Development (NICHD) In 1962, as part of the “New Frontier,” President John F. Kennedy created the National Institute of Child Health and Human Development (NICHD) as a vehicle to explore the impact of human development on the formation of developmental disabilities, including mental retardation. A task force chaired by Dr. Robert E. Cook, the Kennedy pediatrician and an adviser to the president, recommended that research into the area of mental retardation be pursued by establishing facilities for the mentally handicapped in conjunction with academic institutions, building 12 mental retardation research centers on various university campuses, and establishing the institute that became NICHD under the auspices of the National Institutes of Health (NIH). NICHD is located in Building 31 at 31 Center Drive, Bethesda, Maryland 20892. Information is available by telephone (1-800-370-2943) or on the internet (http:// www.nichd.nih.gov/). The overall mission of NICHD is to guarantee that all infants will be born healthy and wanted, that the reproductive process is safe for all women, and that all children reach their full potential, whatever that might be. To this end, NICHD has pursued its goal of gaining a broader understanding of child and adult health through research that traces development from the preconception stage into adulthood. The validity of NICHD research in conjunction with other research groups has been documented by a number of significant advances in infant and child health. Infant mortality has dropped by more than 70 percent since 1963. In the 1960s, only 5 percent of infants who experienced respiratory distress survived. Today, the survival rate is 95 percent because of the use of replacement lung surfactant. In 1994, NICHD introduced the Back to Sleep education campaign, which taught new parents to place infants on their backs rather than on their stomachs. This campaign helped to reduce the incidence of sudden infant death syndrome (SIDS) by 50 percent. Partially through HIV research, motherto-child transmission of HIV/AIDS has been slashed from 25 percent to less than 2 percent. NICHD sci-
The overall mission of NICHD is to guarantee that all children will be born healthy and wanted.
entists developed the Hib vaccine that cut the incidence of Haemophilus influenzae B (Hib), a known cause of acquired mental retardation, by 99 percent. Screening tests for congenital hypothyroidism and phenylketonuria, both causes of mental retardation among infants, allow immediate diagnosis and treatment/therapy. When NICHD was created, the Center for Research in Child Health and the Center for Research in Aging were transferred to the new agency. In 1968, the Center for Population Research was added. Two years later, the Epidemiology and Biometry Branch of NICHD became the Epidemiology and Biometry Research Program, paving the way for new research into reproductive, maternal, and child health. In 1975, the Center for Research for Mothers and Children was established and charged with expanding existing knowledge of pregnancy, infancy, childhood, adolescence, and adulthood. Ten years later, NICHD set up Neonatal Intensive Care Units and Maternal-Fetal Medicine Units as research networks with the ability to more effectively evaluate care and treatment during clinical trials. Congress funded Child Health Research Centers programs in 1989, giving NICHD the ability to immediately apply research findings to the treatment of ill children. The addition of the National Center for Medical Rehabilitation Research in 1990 provided NICHD with new avenues for physical rehabilitation. Research capabilities on child development were further expanded in 2003 with the addition of the Center for Development Biology and Perinatal
1186 National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) Medicine. The following year, the Obstetric and Pediatric Pharmacology Branch was added to NICHD and assigned the mission of conducting research on drugs used to treat children. SEE ALSO: Child Abuse; Child Behavior Disorders; Child
Mental Health; Child Safety; Childhood Immunization.
Bibliography. Committee on Evaluation of Children’s
Health, et al., Children’s Health, The Nation’s Wealth (National Academic Press, 2004); Daniel Clay, Helping Schoolchildren with Chronic Health Conditions: A Practical Guide (Guilford, 2004); Janet Golden, et al., Children and Youth in Sickness and in Health: A Handbook and Guide (Greenwood, 2004); Kristine Krapp and Jeffrey Wilson, eds., The Gale Encyclopedia of Children’s Health: Infancy through Adolescence (Thomas Gale, 2005); National Institute of Child Health and Human Development, http://www.nichd.nih. gov (cited July 2007); National Survey of Children’s Health: The Health and Well-Being of Children in Rural Areas, http://www.mchb.hrsa.gov/ruralhealth/printit.htm (cited July 2007); Sharna Olfman, Childhood Lost: How American Culture Is Failing Our Kids (Praeger, 2005). Elizabeth R. Purdy, Ph.D. Independent Scholar
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) The National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) is part of the National Institutes of Health (NIH). According to its mission, NIDDK research focuses on diabetes and other endocrine and metabolic diseases, liver and other digestive diseases, nutritional disorders, obesity, kidney and urologic diseases, and hematologic diseases. These diseases are studied through basic and innovative research, clinical trials, and training and career development. Since early intervention is the key to treating diabetes and digestive and kidney diseases, it is imperative that the public be kept abreast of research findings. NIDDK disperses information chiefly through the National Diabetes Education
Program, the National Kidney Disease Education Program, the Weight-Control Information Network, and newly instituted programs geared toward promoting celiac disease awareness and women’s urological health. The NIDDK is organized into a number of divisions under the Office of the Director, which encompasses the Executive Office, the Office of Communications and Public Liaison, the Office of Scientific Program and Policy Analysis, the Office of Minority Health Research Coordination, the Office of Obesity Research, and the National Diabetes and Digestive and Kidney Diseases Advisory Council. Separate NIDDK divisions include Diabetes, Endocrinology, and Metabolic Diseases; Digestive Diseases and Nutrition; Kidney, Urologic, and Hematologic Diseases; Nutrition Research Coordination; Extramural Activities; and Intramural Research. Eleven separate laboratories and 13 distinct branches are housed within the Division of Intramural Research. NIDDK is located at 31 Center Drive, Bethesda, Maryland 20892. Additional information is available by telephone (1-800-891-5390) and on the NIDDK Web site (http://www2.niddk.nih.gov/). Diabetes and digestive and kidney diseases affect Americans of all ages, ethnicities, and socioeconomic backgrounds. For instance, around 21 million Americans have been diagnosed with diabetes, and another 6.2 million have diabetes without knowing it. Some 20 million individuals suffer from some form of kidney disease. All of these diseases may become debilitating, and in the most severe cases, they lead to death. Patients who have experienced kidney failure, for instance, generally undergo dialysis three times a week. Few of these patients survive more than five years after dialysis begins. In addition to diabetes and kidney disease, specific diseases included in the NIDDK mission categories are obesity, hepatitis, inflammatory bowel disease, anemia, and prostate enlargement. Costs associated with these diseases are enormous. Diabetes-related medical costs, for instance, were estimated at $132 billion in 2002. Research on all these diseases tends to be incremental, but over time, NIDDK research has been successful in expanding understanding of the diseases and in developing new treatments. Through cutting-edge tools such as bioinformatics and microar-
National Institute of Environmental Health Sciences (NIEHS)
ray technology, NIDDK researchers are now able to study the human genome sequence. This research may ultimately lead to the prevention of the diseases that are the focus of NIDDK activity. Two new NIDDK initiatives hold great promise for the future health of Americans. The Advances and Emerging Opportunities in Type 1 Diabetes Research strategy is geared toward identifying genetic and environmental causes of type 1 diabetes, preventing or reversing the disease, developing cell replacement therapy, preventing or reducing hypoglycemia (a condition in which insulin causes blood glucose to plummet) in type 1 diabetes, preventing or reducing the complications of the disease, and recruiting new researchers and applying new research technologies in the study of diabetes. The second NIDDK initiative is focused on reducing kidney disease among African Americans by promoting family discussions concerning diseases such as diabetes and high blood pressure that can lead to kidney disease. See also: Diabetes; Digestive Diseases; Kidney Diseases
(General).
Bibliography. Ashley M. Ford, ed., Focus on Diabe-
tes Mellitus Research (Nova Biomedical, 2006); Shaul G. Massry and Richard J. Glassock, Massry and Glassock’s Textbook of Nephrology (Lippincott, Williams, and Wilkins, 2001); National Digestive Diseases Information (NDDIC) Clearinghouse, Facts and Fallacies about Digestive Diseases (NDDIC, et al., 1986); National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), http://www2.niddk.nih.gov/ (cited July 2007); NIDDK, Diagnosis of Diabetes (NIDDK, et al, 2004). Elizabeth R. Purdy, Ph.D. Independent Scholar
National Institute of Environmental Health Sciences (NIEHS) The National Institute of Environmental Health Sciences (NIEHS) focuses on reducing illness by under-
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standing the impact of the environment on human disease. Researchers employ multiple scientific disciplines to accomplish this goal. NIEHS is one of the 27 National Institutes of Health (NIH) established by Congress. The NIEHS funds research at universities across the United States, and this agency is credited with documenting the negative effects of asbestos exposure, developmental disabilities in children because of exposure to lead, and illnesses based on pollutants. In 1994, Dr. Martin Rodbell, a researcher using NIEHS laboratories, received the Nobel Prize in Medicine and NIEHS scientists identified the first breast cancer gene. In 1995, NIEHS researchers identified a gene that suppresses the development of prostate cancer. Current projects include health disparities research, wherein researchers delve into how poverty and environmental pollution in tandem affect health. Poorer Americans tend to live in homes with lead paint, may live nearer to hazardous sites, and/or may live near more polluted water and air. This information is given to health policy makers to reduce the disparity in health status among populations in the United States. NIEHS has also provided grants to assist communities in dealing with environmental health issues specific to their region. Other researchers study birth defects, developmental disabilities, causes and incidences of sterility, and breast and testicular cancers. Research parameters include determining how environmental chemicals contribute to the development of these diseases. NIEHS also dedicates resources to women’s health issues such as osteoporosis, Alzheimer’s disease, Parkinson’s disease, Lou Gehrig’s disease (amyotrophic lateral sclerosis), and other neurological, immunological, and endocrine-based diseases. Still other projects are based on lead hazards and their effects on fertility and pregnancy, and in the depletion of vital vitamins in the human body; agricultural pollution and its affects on bronchitis and other lung diseases; and signal errors in the human body, wherein environmental pollutants trigger hormonal reactions that may lead to cancer or reproductive disabilities. Other NIEHS initiatives include the reduction of animals used in research, providing information about pesticides and other pollutants to the American
1188 National Institute of Mental Health (NIMH) public, and the development of markers that identify the level of exposure of toxins in humans. The NIEHS has developed a strategic plan for future research with seven major goals. These include the expansion of clinical research in environmental health science when attempting to understand complex human diseases; a more fully developed understanding of how environmental pollutants affect the human body and genomics; the building of environmental health research programs that are interdisciplinary and integrative in nature and that provide information access to researchers of all relevant disciplines; the expansion of community-based research, especially in areas with high incidences of environmental agents believed to cause disease; the development of environmental exposure markers; recruiting and training of new environmental health scientists; and the fostering of collaborations, both within the NIH structure and without. SEE ALSO: Environmental Health; Environmental Toxi-
cology; International Genetic Epidemiology Society (IGES); International Society for Environmental Epidemiology (ISEE); National Environmental Health Association (NEHA); National Institutes of Health (NIH). Bibliography. National Institute of Environmental
Health Sciences, http://www.niehs.nih.gov (cited July 2007); Lorri A. Zipperer, ed., The Health Care Almanac: A Resource Guide to the Medical Field (American Medical Association, 1995). Kelly Boyer Sagert Independent Scholar
National Institute of Mental Health (NIMH) The National Institute of Mental Health (NIMH), which operates under the auspices of the National Institutes of Health (NIH), is the premier federal government agency responsible for conducting research on mental and behavioral disorders and for communicating with the public, the media, and the medical community about these conditions. The mission of NIMH is to mitigate the consequences of mental illness and
behavioral disorders through research involving the mind, brain, and behavior. Both policy and research are viewed as collaborative efforts at NIMH, and the National Advisory Mental Health Council has a voice in all major decisions. As mandated by Congress, this council is composed of members of the public as well as scientists. The NIMH Outreach Partnership Program operates on a nationwide basis to bring mental health advocates together, and the Board of Scientific Counselors is responsible for scientific and peer reviews and evaluation of NIMH laboratories. NIMH is located at 6001 Executive Boulevard in Bethesda, Maryland 20892. Information on the agency is available tollfree by telephone (1-866-615-6464) or on the internet (http://www.nimh.nih.gov/). NIMH was established in 1949 and housed within NIH, which had been founded three years before in accordance with the National Mental Health Act. In 1955, NIMH partnered with 35 other organizations to produce Action for Mental Health, which provided the first comprehensive assessment of the state of mental health in the United States. The report provided much of the foundation for President John F. Kennedy’s campaign to make the study and treatment of mental health a national priority, which in turn led to the enactment of the Mental Retardation Facilities and Community Health Centers Construction Act. NIMH was charged with monitoring the new facilities. In the mid-1960s, through President Lyndon B. Johnson’s War on Poverty, NIMH was able to establish research centers devoted to schizophrenia, child and family mental health, suicide, crime and delinquency, minority group mental health problems, and urban problem. Subsequently, new centers were established to deal with with rape, aging, and disaster response. Children’s mental health issues were moved to the front burner with the passage of the Social Security Amendments of 1965, and substance abuse was addressed with the establishment of the National Center for Prevention and Control of Alcoholism and a drug abuse research program under the NIMH umbrella. President Jimmy Carter returned mental health to the forefront, in large part because of the advocacy of the First Lady, Rosalyn Carter, who served as honorary chair of the President’s Commission on Mental Health. In 1980, Congress passed the Mental Health System Act in response to the Commission’s recom-
National Institute of Neurological Disorders and Stroke (NINDS)
mendations, and NIMH received increased funding for significant research programs. However, the Act was repealed the following year under the Reagan administration and replaced with block grants to states. Consequently, NIMH’s role was reduced to serving as technical adviser for state programs. In June 1999, President Bill Clinton held the first White House Conference on Mental Health, and NIMH played a major role in bringing national leaders, scientists, clinicians, and consumers together to discuss mental health issues and priorities. Research at NIMH consists of basic research and clinical trials conducted in conjunction with more than 1,000 scientists who are affiliated with hospitals and universities around the United States. Grants are awarded according to relevance to the NIMH mission; traction, which deals with cutting-edge research that is capable of shedding light on outstanding issues; and innovation, which promises to expand the scope of current mental health research. Specific areas of NIMH research include anxiety disorders, attention deficit hyperactivity disorder (ADHD and ADD), autism spectrum disorders, bipolar disorder, borderline personality disorder, depression, eating disorders, obsessive compulsive disorder, panic disorder, post-traumatic stress disorder (PTSD), schizophrenia, and social anxiety disorder. Without proper medical treatment and care, these conditions may be life threatening. Data from the World Health Organization indicate that on a global basis, mental disorders account for four of the top five leading causes of death and disability in individuals between the ages of 15 and 44. Institute leadership is provided through the Office of the NIMH Director who oversees seven divisions: Neuroscience and Basic Behavioral Science, Adult Translational Research and Treatment Development, Pediatric Translational Research and Treatment, AIDS and Health and Behavior Research, Services and Intervention Research, Extramural Activities, and Intramural Research Programs. With an operating budget of $1.4 billion, NIMH is able to fund research in significant areas of mental health that expand the scope of the research conducted at the Institute by 500 NIMH scientists within the Intramural Research Programs. Through the Extramural Activities program, more than 2,000 NIMH grants support research within the United States and abroad. Approximately 10 percent of NIMH’s budget is allocated to research training.
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SEE ALSO: Anxiety Disorders; Attention Deficit Disorder;
Attention Deficit Disorder with Hyperactivity; Autism; Bipolar Disorder; Brain Diseases; Depression; Eating Disorders; Mental Health; National Institutes of Health (NIH); Obsessive-Compulsive Disorder; Schizophrenia. Bibliography. Jon G. Allen, Coping with Depression: From Catch-22 to Hope (American Psychiatric Publishers, 2006); Kenneth J. Meier and Laurence J. O’Toole Jr., Bureaucracy in a Democratic State: A Government Perspective (Johns Hopkins University Press, 2006); Robert G. Meyer and Christopher M. Weaver, Law and Mental Health: A Case-Based Approach (Guilford, 2006); National Institute of Mental Health, http://www.nimh.nih.gov (cited July 2007); R. Paul Olson, ed., Mental Health Systems Compared: Great Britain, Norway, Canada, and the United States (Charles C. Thomas, 2006); Marc N. Potenza, ed., Textbook of Men’s Mental Health (American Psychiatric Publishers, 2007); Dennis D. Riley, et al., Bureaucracy and the Policy Process: Keeping the Promises (Rowman & Littlefield, 2006); Sarah Romans and Mary V. Seeman, eds., Women’s Mental Health: A Life-Cycle Approach (Lippincott, Williams, and Wilkins, 2006).
Elizabeth R. Purdy, Ph.D. Independent Scholar
National Institute of Neurological Disorders and Stroke (NINDS) The National Institute of Neurological Disorders and Stroke (NINDS) conducts research on the causes, diagnoses, prevention, and treatment of neurological (brain and spinal cord) disorders and strokes; provides grants for public and private institutions to conduct relevant research; trains new researchers; and shares information about neurological disorders with collaborators, governmental agencies, and the general public. NINDS, formed in 1950, is one of 27 National Institutes of Health (NIH) established by Congress. Nearly 50 percent of human genetic material is located in the brain and nearly one-third of genetic disorders—totaling more than 600 diseases—affect the nervous system. These range from strokes, epi-
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National Institute of Nursing Research (NINR)
lepsy, Parkinson’s disease, and autism to lesser known disorders. Approximately 50 million Americans deal with neurological disabilities each year, which adds billions of dollars to annual medical expenditures in the United States. NINDS operates one of the largest neurological research centers in the world; more than 500 scientists conduct research in over 200 NINDS labs. Specific foci include biophysics, molecular and cellular neurobiology, synapses and circuits, neuronal development, integrative neuroscience, brain imaging, and both neurological and psychiatric disorders. Researchers conduct baseline research to determine how the nervous system operates under optimal or normal situations; this provides useful contrasts when researching abnormalities and disorders. Current subjects of NINDS research include cell biology of the nervous system; neurological development; brain genetics; cognition and behavior; the plasticity of the brain and its ability to repair itself; neural signaling; and learning, memory, motor control and sensory function. A prime focus of NINDS is neurodegeneration, wherein brain cells die after strokes, traumas, and as part of certain diseases. Typically, mature brains do not regenerate cells, so neurogenetics researchers are attempting to determine how brain cells die and to search for ways to minimize cell death. These scientists also study the interplay of environment and genetics to discover ways to prevent and/or treat neurological diseases. NINDS researchers study the role of proteins in electric brain activity; genetic substances that help form the hard wiring of the brain; chemicals that transport substances to cells; and receptors that receive signals from molecules. It seems likely that although some neurological disorders are due to a single gene defect, most diseases are caused by a complex interplay of genetic factors. Diagnostic tools such as brain imagery and experimental therapies such as stem cell implants are studied at NINDS, for treatments of diseases such as AIDS, Alzheimer’s disease, brain tumors, development disorders, epilepsy, muscular dystrophy, multiple sclerosis, and Parkinson’s disease, as well as for strokes, spinal cord injuries, and brain trauma. To accomplish these multilayered goals, NINDS is promoting interdisciplinary study and training, and research that spans the gap from basic research to
clinical research. NINDS is actively attempting to increase the number of scientists and researchers from underrepresented populations who are involved in neurological research. . SEE ALSO: National Institutes of Health (NIH); Neurologi-
cal Diseases (General); Neurology; Neuroscience; Stroke.
Bibliography. National Institute of Neurological Dis-
orders and Stroke, http://www.ninds.nih.gov (cited July 2007); Lorri A. Zipperer, ed., The Health Care Almanac: A Resource Guide to the Medical Field (American Medical Association, 1995).
Kelly Boyer Sagert Independent Scholar
National Institute of Nursing Research (NINR) The National Institute of Nursing Research (NINR) works to establish a scientific basis for the care of patients during illness and recovery, to discover ways to reduce risks for disease, and to promote an overall healthy lifestyle. NINR researchers study the onset of symptoms of disease and research methods of reducing the pain of those experiencing symptoms of disease. NINR researchers study ways to delay the onset of diseases and/or to slow down the progression, and they seek to improve the clinical healthcare settings where nurses provide care. NINR is one of the 27 National Institutes of Health (NIH) established by Congress; it was formed in 1985 after Congress overrode a presidential veto. NINR researches problems encountered by patients, their families, and their caregivers, and search for solutions. It pays particular attention to underserved populations, based on race, gender, socioeconomic factors, ethnic origins, and culture. Special research foci include long-term care for mature adults, women’s health through the life span, bioethical concerns connected with genetic testing and counseling, infectious diseases, and the environmental influences on chronic diseases. A significant portion of NINR studies focuses on health promotion and disease prevention, and the
National Institute of Occupational Safety and Health (NIOSH)
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of HIV/AIDS in a multicultural society, parenting capacity studies, biobehavioral methods, and improving quality of life. NINR sponsors research awards for individuals and institutions. It also offers the “Mentored Research Scientist Development Award: Nursing,” which provides a mentored research experience for doctorally prepared students. NINR also funds minority research mentoring awards; through this program, researchers have addressed developmental issues in Mexican migrant babies, prostate cancer screening awareness for African-American men, and triggers seen in sudden deaths of Asian patients who died of heart failure. The NINR has collaborated with the National Center on Minority Health and Health Disparities, jointly creating the Nursing Partnership Centers on Reducing Health Disparities. This Center has a dual goal: to increase health disparities research and to broaden the diversity of researchers. Each summer, the NINR offers the Summer Genetics Institute, a two-month program that offers nurses an understanding of molecular genetics and clinical genetics issues. SEE ALSO: National Institutes of Health (NIH); Nurses
Health Study. NINR researches problems encountered by patients, their families, and their caregivers, and search for solutions.
ways in which human behavior and lifestyle choices affect disease and disease prevention. Another focus of research is managing symptoms in both acute and chronic illness. Researchers have a two-pronged strategy: to find ways to relieve symptoms and to provide information to health officials that uses symptom severity as a diagnostic tool and perhaps also as a benchmark of the success of treatments attempted. NINR studies self-management techniques of pain symptoms to assist those with chronic diseases and it serves as the leading NIH agency in the study of end-of-life palliative care. Important aspects of this research include pain management, assisting families in decision making and care giving, and care of the elderly and the critically ill. Research initiatives established as priorities in 2006 include the prevention
Bibliography. “The First 15 Years at the Nation-
al Institute of Nursing Research,” Research Channel, http://www.researchchannel.org/prog/displayevent. aspx?rID=2711&fID=567 (cited July 2007); National Institute of Nursing Research, http://www.nih.gov/about/almanac/organization/NINR.htm (cited July 2007).
Kelly Boyer Sagert Independent Scholar
National Institute of Occupational Safety and Health (NIOSH) The National Institute of Occupational Safety and Health (NIOSH) conducts research on workplace injuries and illness, and then the agency makes recommendations on preventative measures. The
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National Institute on Aging (NIA)
overall goal of the agency is to create a safe and healthful work environment for all Americans. NIOSH also provides education and training in occupational safety and health. Created in 1970 along with the Occupational Safety and Health Administration (OSHA), NIOSH is part of the Centers for Disease Control and Prevention (CDC) and the Department of Health and Human Services (HSS). It should be noted that NIOSH and OSHA are separate entities created through the same legislation. On average, 9,000 workers receive significant workplace injuries on a daily basis; 16 workers die and 137 die from a workplace-related cause. NIOSH is charged with determining safe levels of toxic material exposure in workplaces; conducting inspections to discover toxicity levels existing in current workplaces; researching newly noted health and safety issues; and funding relevant research. NIOSH collaborates with international organizations as well to promote global workplace health and safety. In 1977, the government, through the passage of the Federal Mine Safety and Health Amendment Act, added a new responsibility to NIOSH: coal miner health and safety. The agency needed to develop health standards, create medical programs for coal miners that included chest X-rays, and conduct on-site investigations. In 1988, NIOSH collaborated with the National Institute of Environmental Health Sciences (NIEHS) to create hazardous substance training programs targeted toward agencies that clean up hazardous materials and/or enforces regulations. In 1996, NIOSH helped found the National Occupational Research Agency (NORA) which conducts research on traumatic injuries, hearing loss, and other areas deemed high priorities. Recent foci of NIOSH include a virtual reality program wherein researchers can study risk factors of falls, the main cause of construction industry deaths. NIOSH also studies methods of preventing the spread of tuberculosis in healthcare settings along with ways to prevent back injuries among healthcare personnel. Through the NIOSH Health Hazard Evaluation (HHE) program, employers and employees alike can request an evaluation of their workplace. NIOSH representatives identify hazards and make recommendations to prevent injury, illness, and fatalities.
Other NIOSH initiatives include the Fire Fighter Fatality Investigation and Prevention Program, with the International Association of Firefighters (IAFF), for all first responders, including paramedics; the National Personal Protective Technology Laboratory for industries relying upon body protection such as hard hats; and the NIOSH Agricultural Centers Program. NIOSH works with state health departments through the Sentinel Event Notification System for Occupational Risks (SENSOR) and the Adult Blood Lead Epidemiology and Surveillance Program (ABLES) in two-thirds of the states. Other NIOSH resources include 16 regional training centers and 35 training grants to encourage those who wish to pursue occupational health careers. The NIOSH Web site contains a significant amount of educational resources as well. SEE ALSO: Centers for Disease Control and Prevention
(CDC); National Institute of Environmental Health Sciences (NIEHS); Occupational Health; Occupational Injuries; Occupational Safety and Health Administration (OSHA). Bibliography. National Institute of Occupational Safety
and Health, http://www.cdc.gov/niosh/ (cited July 2007). Lorri A. Zipperer, ed., The Health Care Almanac: A Resource Guide to the Medical Field (American Medical Association, 1995). Kelly Boyer Sagert Independent Researcher
National Institute on Aging (NIA) Operating under the auspices of the National Institutes of Health since 1974, the National Institute on Aging (NIA) is committed to developing a researchbased understanding of aging and improving the quality of life for American seniors. NIA also serves as the major federal agency devoted to research in Alzheimer’s disease. Other specific NIA research areas include the aging process, age-related diseases, and special problems and needs of the elderly. The NIA’s mission is carried out through training and development of researchers, the development and maintenance of
state-of-the-art resources, and the dissemination of information to the public in a timely manner. The extramural work of the NIA is divided among four programs: Biology of Aging, Behavioral and Social Research, Geriatrics and Clinical Gerontology, and Neuroscience and Neuropsychology of Aging. The NIA Intramural Research Program consists of 11 scientific laboratories, a clinical research branch, a research resources support branch, and two sections that deal with biochemistry, cell and molecular biology, genetics, physiology, immunology, neuroscience, neurogenetics, behavioral sciences, epidemiology, statistics, and clinical research and medical disciplines that include neurobiology, immunology, endocrinology, cardiology, rheumatology, hematology, oncology, and gerontology. NIA is located in the Gateway Building at 7201 Wisconsin Avenue in Bethesda, Maryland 20892. Information is available by telephone (1-800-222-2225) or over the internet (http://www.nia.nih.gov/). In addition to the main facilities, NIA maintains laboratories at the Gerontology Research Center and the Triad Building at the Johns Hopkins Bayview Campus in Baltimore, Maryland. The Clinical Research Branch’s Advanced Studies in Translational Research on Aging is housed at Harbor Hospital in Baltimore. Laboratories headquartered at the Bethesda location include Brain Physiology and Metabolism, the Laboratory of Neurogenetics, and the Laboratory of Epidemiology, Demography, and Biometry. Partially in response to the work of NIA and other groups devoted to geriatric research, Americans are living longer lives and are healthier during the aging process. Between 1900 and 2000, life expectancy increased from less than 50 years to 77.85 years (80.82 years for American females and 75.02 years for males). From 1960 to 2000, the number of Americans aged 65 and older doubled, and that population is expected to double again by 2030. The percentage of Americans reaching the age of 85 is likewise expected to rise dramatically, swelling from 4.3 million in 2000 to 19.4 million by 2050. NIA is committed to make life healthier among this rising population by enhancing treatments for age-related conditions and preventing and delaying the onset of diseases and disabilities. To this end, NIA continues to award research grants and contracts, training grants, and individual fellowships to scientists affiliated with universities
National Institute on Aging (NIA)
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The National Institute on Aging is committed to developing an understanding of aging and improving the quality of life for seniors.
and research institutions. As a leader in age-related research, NIA chairs the NIH Inter-Institute Alzheimer’s Disease Working Group, the Interagency Ad Hoc Committee on Research on Aging, and the Interagency Forum on Aging Related Statistics. Specific collaborative research efforts involve cardiovascular disease, cancer, neurologic disease, osteoporosis, osteoarthritis, diabetes, AIDS, behavioral health, and alternative medicine. Aware that race, ethnicity, gender, socioeconomic status, age, education, and occupation have distinct impacts on health, NIA is determined to address the issue of health disparities. Increased knowledge of the affect of genetics, the environment, and lifestyle on longevity is helping NIA researchers to develop methods of mitigating those differences. Research has revealed that African Americans are more sus-
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National Institute on Alcohol Abuse and Alcoholism (NIAAA)
ceptible than other Americans to a myriad of diseases and conditions, including Alzheimer’s, cardiovascular disease, cancer, and kidney disease. NIA is currently involved in 31 separate initiatives that are expected to increase understanding of how diseases and disabilities develop among aging racial and ethnic minorities. These initiatives include Epidemiology of Alzheimer’s Disease; Normal Cognitive Aging; Menopause; Physical Function and Disability; Cancer, Aging, Race, and Ethnicity; and Racial and Ethnic Differences in Health in Late Life in the United States. SEE ALSO: AIDS; Alternative Medicine; Arthritis; Cancer
(General); Diabetes; Heart Diseases (General); National Institutes of Health (NIH); Neurological Diseases (General); Osteoporosis. Patricia M. Burbank, ed., Vulnerable Older Adults: Health Care Needs and Interventions (Springer, 2006); Julie K. Gammack and John E. Morley, eds., Geriatric Medicine (Saunders, 2006); Malcolm Johnson, ed., The Cambridge Handbook of Age and Ageing (Cambridge University Press, 2005); Stephen Katz, ed., Cultural Aging: Life Course, Lifestyle, and Senior Worlds (Broadview, 2005); Robert Katzman and Katherine Beck, Alzheimer Disease: The Changing View (Academic Press, 2000); Losing a Million Minds: Confronting the Tragedy of Alzheimer’s Disease and Other Dementias (U.S. Government Printing Office, 1987); Assaf Razin and Efraim Sadka, The Decline of the Welfare State: Demography and Globalization (MIT Press, 2005); Harold C. Relyea and Thomas P. Carr, The Executive Branch: Creation and Organization (Novinka, 2003). Bibliography.
Elizabeth R. Purdy, Ph.D. Independent Scholar
National Institute on Alcohol Abuse and Alcoholism (NIAAA) The National Institute on Alcohol Abuse and Alcoholism (NIAAA) conducts research to determine the heath risks and benefits of alcohol consumption,
Alcohol-use disorders (AUDs) are defined by a dependence upon alcohol arising from drinking too much, too fast, and/or too often.
and to create prevention and treatment programs for alcohol-use disorders. NIAAA collaborates with governmental agencies and research institutes in the United States and globally to conduct research and to present information to policy makers, healthcare professionals, researchers, and the general public. NIAAA is now one of the 27 National Institutes of Health (NIH) established by Congress. Federal-level testimony to create an alcohol-use– focused agency began in 1969, as scientists, clergy, healthcare providers, and people who had experienced alcohol-use disorders testified about a need for an agency; this included Bill Wilson, founder of Alcoholics Anonymous. Although a presidential veto was feared, in 1970, President Richard Nixon signed into law the Comprehensive Alcohol Abuse and Alcoholism Prevention, Treatment, and Rehabilitation Act. Initially, NIAAA reported to the National Institute of Mental Health (NIMH) and was charged with providing alcoholism programs to federal civilian employees and assisting states in developing and maintaining prevention, treatment, and rehabilitation programs. The 1970 Act prohibited employment-based discrimination of “recovered alcoholics in nonsecurity jobs,” and discrimination in healthcare facilities that
National Institute on Deafness and Other Communication Disorders (NIDCD)
received federal funds. This Act also established the National Advisory Council on Alcohol Abuse and Alcoholism. It was not until 1976 that NIAAA received the authorization to conduct independent research. Alcohol-use disorders (AUDs) are defined by a dependence upon alcohol arising from drinking too much, too fast, and/or too often. Alcohol abuse is defined as high-risk drinking that causes problems for the drinkers and others. Alcohol dependence or alcoholism is a complex disease wherein the person loses control over drinking, is preoccupied with alcohol, and develops a tolerance. Excess alcohol consumption is the third most prevalent cause of preventable deaths in the United States; 18 million Americans—8.5 percent of the population aged 18 or older—suffer from AUD. Current initiatives of NIAAA include research on medications to treat alcohol-use disorders; risks of alcohol-use vulnerability based on genetics and behavior; organ damage and organ protection; community-based alcohol prevention programs focused on the under-aged and the elderly; fetal alcohol syndrome; and women, HIV/AIDS, and alcohol. Programs of the NIAAA include the Health Disparities Initiatives 2005, wherein the agency provides resources and knowledge to the alcohol research community serving minority populations. Another program, Leadership to Keep Children Alcohol Free, focuses on preventing alcohol use in children aged 9 through 15; College Drinking Prevention focuses on the elimination of excessive drinking on college campuses, which would also reduce the number of injuries, assaults, academic issues, vandalism, and arrests and other social, health, and behavioral problems; the Initiative on Underage Drinking, which targets alcohol consumption of those under age 21; and the Interagency Coordination Committee on Fetal Alcohol Syndrome (FAS), which focuses on the causes of and preventative measures for FAS. SEE ALSO: Alcohol and Youth; Alcohol Consumption;
Alcoholism; Fetal Alcohol Syndrome; National Institutes of Health (NIH); National Institute of Mental Health (NIHM). Bibliography. National Institute on Alcohol Abuse and
Alcoholism, http://www.niaaa.nih.gov (cited July 2007);
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Lorri A. Zipperer, ed., The Health Care Almanac: A Resource Guide to the Medical Field (American Medical Association, 1995). Kelly Boyer Sagert Independent Scholar
National Institute on Deafness and Other Communication Disorders (NIDCD) The National Institute on Deafness and Other Communication Disorders (NIDCD) is the federal agency charged with conducting biomedical research to prevent, detect, diagnose, and treat communication disorders in the areas of hearing, balance, smell, taste, voice, speech, and language. NIDCD is one of the 27 National Institutes of Health (NIH) agencies established by Congress. Formed in 1988, NIDCD also conducts research in more general disease prevention and health promotion areas; addresses behavioral issues of those with communications disorders; and assists in the creation of devices that improve sensory loss in the more than 46 million Americans afflicted with such a disorder. The agency uses a multidisciplinary approach: sciences include molecular genetics, biomedical imagining, nanotechnology, linguistics, psychoacoustics, and structural biology. NIDCD supports approximately 600 research projects, including those conducted in the NIH labs and those conducted at universities and research facilities around the country through the financial support of NIDCD. Grants have been recently awarded to develop an otitis media vaccination; to identify patterns responsible for genetic hearing loss and human communication difficulties; and the treatment of voice disorders. The NIDCD Information Clearinghouse, formed in 1991, provides an information service, coordinates the publications of the agency and maintains an extensive reference library on communication disorders. Through the clearinghouse, the public can re-
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National Institute on Drug Abuse (NIDA)
ceive answers to questions, either through the mail or by telephone, and obtain directories, fact sheets, brochures, and much more on a broad spectrum of sensory disorders. The agency provides teachers with multiple types of classroom activities, including printed material, games, videos, and more. NIDCD also conducts the WISE EARS campaign, wherein they educate the public on ways to avoid noise-induced hearing loss; Healthy Hearing 2010, under which the agency provides communication and sensory types of health information for the national program, Healthy People 2010; and Health Literacy, which assists Americans in understanding the health information being presented to them. NIDCD also provides information on a wide variety of topics for the general public. Subjects include ear infections and their connection to deafness; American Sign Language; hearing aids; noise-induced hearing loss; individual hearing disorders; Meniere’s disease and other balance disorders; auditory processing disorders in children; speech and language milestones; and statistical information about human communication, both normal and disordered. Recently published research shares information about cochlear implants that uses laser treatments to stimulate the auditory nerve; current cochlear implants, which use electrodes rather than light for stimulation, provide the profoundly deaf with an ability to hear some sounds. Laser-induced implants, however, could pinpoint nerve cells much more accurately than electrodes and there is hope that cochlear implants in the future could provide significantly more hearing ability to those who need the treatment. SEE ALSO: Hearing Problems in Children; National Insti-
tutes of Health (NIH); Speech & Communication Disorders. Bibliography. National Institute on Deafness and other
Communication Disorders, http://www.nidcd.nih.gov/index.asp (cited July 2007); Lorri A. Zipperer, ed., The Health Care Almanac: A Resource Guide to the Medical Field (American Medical Association, 1995). Kelly Boyer Sagert Independent Scholar
National Institute on Drug Abuse (NIDA) The National Institute on Drug Abuse (NIDA), established in 1974, is the federal agency charged with conducting research to understand the causes of drug abuse and addictions, and to use this research to develop preventative measures and effective treatments. Research ranges from spearheading molecular science initiatives and genetics studies to creating community-based outreach programs. NIDA forwards research results to policy makers, healthcare professionals, other researchers, and the general public. In 1992, NIDA became one of the country’s 27 National Institutes of Health (NIH) agencies established by Congress. Accomplishments of NIDA have been significant. Through NIDA support, researchers have identified the specific brain sites wherein every abused drug of significance, which includes opiates, cocaine, phencyclidine (PCP), and marijuana’s active ingredient, has its initial effect. Armed with this knowledge, NIDA is developing medicinal drugs that may break through these addictions. To date, NIDA has developed three Food and Drug Administration (FDA)–approved medications to treat opiate addiction; has served as a leading force in proving the addictive nature of nicotine; and is supporting the development of patches and gums that help smokers stop that behavior. Vaccinations for both nicotine and cocaine addiction are in development stages. Other research endeavors are more behavioral in nature; NIDA has developed models to study the neurobehavioral patterns of drug users to refine rehabilitation methods. Other research has demonstrated the long-lasting effects of well-developed behavior therapy. In 1986, HIV/AIDS became prime foci for NIDA. That year, Congress quadrupled NIDA funding for drug abuse and HIV/AIDS research. Since then, the agency has conducted community-based prevention research to stop drug abuse, and has had proven success with methadone to decrease high-risk behaviors. In 1998, NIDA formed the Center on AIDS and Other Medical Consequences of Drug Abuse and, in 2002, the agency released Principles of HIV Prevention in Drug-Using Populations: A Research-Based Guide.
National Institutes of Health (NIH)
In 1988, Congress appropriated increased funding for NIDA to research the effects of drugs on mothers and fetuses. Using those funds, the organization helped develop medicines that assist newborns in withdrawing from in utero exposure to drugs. NIDA also documented long-term cognitive difficulties in children exposed to nicotine and marijuana in utero. In 1997, NIDA presented Preventing Drug Use among Children and Adolescents: A Research-Based Guide. Called the first research-based preventative guide for youth, NIDA research has shown how peer influence of high-risk youth can influence drug use of others. The following year, NIDA released, NIDA Goes to School, educational materials targeted at fifth through ninth graders that focus on the dangers of drug abuse. In 2002, NIDA increased its school-based resources, collaborating with Scholastic to provide written materials about drug abuse to children across the nation, and releasing an antidrug program for second and third graders called “Brain Power! The NIDA Junior Scientist Program.” The following year, NIDA activated an antidrug Web site for teens: NIDA for Teens: The Science Behind Drug Abuse. SEE ALSO: AIDS; Drug Abuse; Food and Drug Adminis-
tration (FDA); National Institutes of Health (NIH).
Bibliography. National Institute on Drug Abuse, http://
www.nida.nih.gov (cited July 2007); Lorri A. Zipperer, ed., The Health Care Almanac: A Resource Guide to the Medical Field (American Medical Association, 1995).
Kelly Boyer Sagert Independent Scholar
National Institutes of Health (NIH) The National Institutes of Health (NIH) is the premier research medical organization in the United States. Operating under the auspices of the Department of Health and Human Services (HHS), NIH is composed of 27 separate health agencies that cover a broad range of health and safety concerns through research, clinical
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trials, education and training, federal programs, monitoring, and public service. A complete list of the 20 institutes and 7 centers located within NIH is available online, along with contact information on each agency (http://www.nih.gov/icd/instituteaddresses.htm). The overall mission of NIH is to advance human understanding of the nature and behavior of living systems and apply that knowledge to increasing life spans and mitigating the effects of illness and disability. In practice, NIH is engaged in the study of the causes, diagnosis, prevention, and cure of human diseases; the processes involved in human growth and development; the effects of environmental contaminants on human biology; development of a broader understanding of mental, addictive, and physical disorders; and the collection, dissemination, and exchange of medical and health knowledge. Research areas pursued with NIH funding include child and teen health, men’s health, minority health, elder health, women’s health, and wellness and lifestyle. What is now NIH began in 1887 when the Laboratory of Hygiene was established at the Marine Hospital on Staten Island in New York. This lab ultimately led to the creation of the Commissioned Corps of the Public Health Service (PHS), which is currently housed within NIH. The position of Supervising Surgeon was created in 1870 and placed in charge of the Commissioned Corps. Over time, this position evolved into the Surgeon General of the United States. In 1879, the National Board of Health was created as the first comprehensive federal research-oriented health organization. Eight years later, the Laboratory of Hygiene was established at the Marine Hospital to conduct research into cholera and other infectious diseases. In 1902, the Pan American Sanitary Bureau was established, initiating international health cooperation. Two decades later, PHS established the Special Cancer Investigations Laboratory at Harvard University. On May 26, 1930, under the Ransdell Act, the Hygienic Laboratory was transformed into the National Institutes of Health, with an authorization of $750,000. By 1937, NIH had been divided into eight divisions, and the following year, the institutes relocated to Bethesda, Maryland. Through a series of land donations, Mrs. Luke I. Wilson gifted 92 acres of the current 306.4 acre compound that makes up NIH’s Bethesda headquarters.
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National Institutes of Health (NIH)
The passage of the National Mental Health Act in 1946 provided increased funds for NIH research, allowing NIH to expand its scope of activities. Two years later, the National Heart Act created the National Heart Institute within NIH, and the word Institute in NIH was changed to the plural form. director of nih The director of NIH is responsible for planning, managing, and coordinating the programs of all NIH organizations. The total workforce is composed of 8,627 employees. NIH is headquartered at 900 Rockville Pike in Bethesda, Maryland 20892. Information is available by telephone (301-496-400) or via the internet (http://www.nih.gov/). NIH operates with a budget of $27,887,512,000, and 80 percent of that amount is dispersed in research grants among the 50 states, United States territories, and in selected countries abroad, funding more than 212,000 researchers at more than 2,800 universities, medical, schools, and research institutions. Due to the scope of the NIH grants program, it is essential to garner information from a variety of sources before allocating funds. Consequently, NIH’s advisory process involves scientists, organizations, institute and advisory councils, Congress, the executive branch, the Advisory Committee to the NIH director, the NIH director’s Council of Public Representatives, and NIH staff. Peer review groups that operate under the auspices of the Office of Extramural Research are responsible for evaluating all instigator-initiated grant applications. Ten percent of the NIH budget goes to support the 6,000 scientists, and coordinating research, training, and technology transfer within NIH is the responsibility of the Office of Intramural Research. Grants to multiple institutes and centers are handled through Trans-NIH Scientific Initiatives. The Office of Science Policy serves as an adviser on issues that affect the greater medical research community. The Office of Legislative Policy and Analysis acts as a congressional liaison and furnishes legislative analysis and policy development. Laws, regulations, and policies that deal with federal advisory committees are the responsibility of the Office of Federal Advisory Committee Policy. Each year, scientists funded through NIH grants are involved in breakthrough discoveries that save lives
and improve the quality of lives for millions of people. For instance, researchers conducting a study of 33,357 patients with hypertension recently discovered that diuretics are more effective than new medications in reducing blood pressure and avoiding strokes. Other researchers involved in a longitudinal study discovered that controlling glucose levels in patients with type 1 diabetes may cut risks of heart disease and strokes in half. Computer models led NIH-funded researchers to the discovery that a combination of public health measures instituted at the proper time could circumvent outbreaks of avian flu. research studies Mental health researchers engaged in a study funded by NIH and the Centers for Disease Control and Prevention (CDC) identified a link between cognitive therapy and declines in repeated suicide attempts. The use of vitamin E supplements as heart attack, stroke, and cancer deterrents was proved to be unfounded. The discovery of a link between obesity and dementia may prove to have major consequences for America’s aging population. Other recent advances were made in the areas of cancer, asthma, eye treatment for children, and pregnancy-related conditions. NIH funding has also played a major role in improving health on a global basis. In December 2006, for instance, the NIH Data Safety and Monitoring Board halted clinical trials in Uganda and Kenya when scientists validated a previous South African study, which found that circumcision may cut HIV/AIDS transference in heterosexual sex by half. NIH explained that refusing to perform circumcisions on all men involved in the study would be unethical. SEE ALSO: Department of Health and Human Services
(DHHS); National Cancer Institute (NCI); National Center for Complementary and Alternative Medicine (NCCAM); National Eye Institute (NEI); National Heart, Lung, and Blood Institute (NHLBI); National Human Genome Research Institute (NHGRI); National Institute of Allergy and Infectious Diseases (NIAID); National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMSD); National Institute of Biomedical Imaging and Bioengineering (NIBIB); National Institute of Children’s Health (NICHD); National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK); National Institute on Aging (NIA); National Institute of Environmental Health Sciences (NIEHS);
National Library of Medicine (NLM)
National Institute of Mental Health (NIMH); National Institute of Neurological Disorders and Stroke (NINDS); National Institute of Nursing Research (NINR); National Institute on Alcohol Abuse and Alcoholism (NIAAA); National Institute on Deafness and other Communication Disorders (NIDCD); National Institute on Drug Abuse (NIDA); National Library of Medicine (NLM). Bibliography. Edward H. Ahrens Jr., The Crisis in Clini-
cal Research: Overcoming Institutional Obstacles (Oxford University Press, 1992); Donald G. McNeil Jr., “Circumcision Halves HIV Risky, U.S. Agency Finds,” New York Times Online (December 14, 2006); Kenneth J. Meier and Laurence J. O’Toole Jr., Bureaucracy in a Democratic State: A Government Perspective (Johns Hopkins University Press, 2006); National Institutes of Health (NIH), http://www.nih. gov (cited July 2007); NIH, Windows into NIH History: A Centennial Retrospective (NIH, 1988); Dennis D. Riley, et al., Bureaucracy and the Policy Process: Keeping the Promises (Rowman & Littlefield, 2006); NIH, Improving Health through Discovery (Department of Health and Human Services and NIH, 2004); Gerald E. Thomson, et al., eds., Examining the Health Disparities Research Plan of the National Institutes of Health: Unfinished Business (National Academy Press, 2006). Elizabeth R. Purdy, Ph.D. Independent Scholar
National Library of Medicine (NLM) The National Library of Medicine (NLM) is the library of the United States National Institutes of Health (NIH) and is located on the NIH campus in Bethesda, Maryland. It is the largest medical library in the world. The first Surgeon General of the Army, Dr. Joseph Lovell, set up a shelf of medical books in his office when he took his post in 1818. However, the NLM traces its roots to 1836, with the formal creation of the Library of the Office of the Surgeon General of the Army. The collection grew haphazardly until 1867, when the Army assigned a young doctor named John Shaw Billings to oversee the creation of a comprehensive medical library. Dr. Billings was a bibliophile, and
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by the time he left to head the New York Public Library in 1895, he had grown the collection from a paltry 2,300 volumes to over 124,000 volumes. He was the first to create a catalog of the library’s holdings, and in 1879, he launched the Index Medicus®, a bibliographical bulletin of medical journals that would be published for the next 125 years. The library was renamed over the decades, becoming the Army Medical Library in 1922, the Armed Forced Medical Library in 1952, and finally, the NLM in 1956. In 1962, under the watchful eyes of a group of armed security guards, the collection was moved into its own building on the NIH grounds. Built at the height of the Cold War, it was constructed with extrathick concrete walls, a collapsible roof, and an underground storage facility for the more precious books and documents. Today, NLM maintains a library of over 8.5 million items, most of them focusing on medicine, healthcare, and the biomedical aspects of the humanities, social sciences, and other disciplines. It has a staff of 640 and its 2005 budget was $331.4 million. To fulfill its goal of giving medical professionals access to the latest information available, it has designed the National Network of Libraries of Medicine (NNLM), a consortium with eight regional libraries and nearly 5,000 smaller resource and primary access libraries in medical schools and hospitals nationwide. The NLM has invested heavily in computer database technology since the 1960s. In 1997, it unveiled MEDLINE, giving researchers access to more than 16.5 million bibliographic records and abstracts dating back to the 1950s. The site receives 750 million searches annually. A year later, it launched MedlinePlus, a consumer-oriented Web site providing basic medical information and links to reputable information sources that now receives over 1 billion hits a year. Altogether, NLM maintains 86 separate databases, including ClinicalTrials.gov, TOXNET, AIDSInfo, and the Visible Human Project, an online, three-dimensional look at the human body. While striving to be the most up-to-date collection possible, its archival holdings are considered among the finest repositories of rare medical texts in the world. It contains more that 500,000 printed pieces, ranging from single sheets to bound books. An estimated 70,000 items date to the 16th, 17th, and 18th centuries; the small Islamic collection has items as old as
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The National Library of Medicine (NLM) is the library of the United States National Institutes of Health (NIH) and is located on the NIH campus in Bethesda, Maryland. It is the largest medical library in the world.
the 11th century. The Manuscripts Collections contain 1 million primary source items, and the Prints and Photographs Collection more than 100,000 items. This collection is maintained by the History of Medicine Division.
http://www.nlm.nih.gov/hmd/about/collectionhistory. html (cited July 2007). Heather K. Michon Independent Scholar
SEE ALSO: National Institutes of Health (NIH). Bibliography. “Milestones in NLM History Factsheet,”
Office of Communications and Public Liaison, National Library of Medicine, 2006, http://www.nlm.nih.gov/ about/nlmhist.html (cited July 2007); “The National Library of Medicine Factsheet,” Office of Communications and Public Liaison, National Library of Medicine, http:// www.nlm.nih.gov/pubs/factsheets/nlm.html (cited July 2007); “The NN/LM Factsheet,” Office of Communications and Public Liaison, National Library of Medicine, http://www.nlm.nih.gov/pubs/factsheets/nnlm.html (cited July 2007); “The Story of NLM Historical Collections,”
National Mental Health Association (NMHA) The National Mental Health Association (NMHA), recently renamed Mental Health America (MHA), is the leading nonprofit agency in the United States dedicated to helping people live mentally healthy lives. NMHA has a four-pronged objective: to educate the public about ways to maintain and strengthen mental health; to increase access for effective mental healthcare and to fight against discrimination for those with
National Network for Immunization Information (NNii)
mental and/or addictive disorders; to spearhead research; and to provide support to Americans with mental health and/or substance abuse issues. NMHA also aims to provide schools, businesses, and healthcare settings with the information they need to protect those whom they serve. The NMHA was founded in 1909 when Clifford W. Beers formed a national citizens group to improve the lives of people with mental health; Beers himself had experienced mental illness. The group recently decided to change its name to Mental Health America to portray the organization’s goal of quality mental health for all in the country. The new bell-shaped logo reflects the actual 300-pound MHA bell, which was created from melted-down iron chains and shackles used in mental institutions; this bell was crafted more than 50 years ago and serves as a symbol of progress. The NMHA Web site provides information to the public based on three categories. The first is “By Audience” (African Americans; first responders; en Español; friends and loved ones; older adults; troops and military families; women; workplace; youth and family). Another option is to search for information by “Issue” (AD/HD; anxiety disorders; bipolar disorders; bullying; depression; eating disorders; grief and bereavement; healthy living; military-related; schizophrenia; stigma; stress; substance abuse; suicide; trauma and disaster; treatment and recovery; workplace wellness). Finally, a person can search for information by “Disorders and Treatments,” which include AD/HD; substance abuse and addiction; Alzheimer’s disease; anxiety disorders; autism; bipolar disorders; borderline personality disorder; codependency; conduct disorders; co-occurrence of depression; dementia; depression; disassociation; dysthymic disorders; eating disorders; learning disabilities; mood disorders; obsessive-compulsive disorders; panic disorders; paranoia; postpartum disorders; post-traumatic stress disorders; seasonal affective disorder; self-injury; suicide; and more. NMHA partners with 320 affiliate groups, each of which develops mental health programs suitable for their particular community. Affiliates provide education, support, and rehabilitation programs and services to those in need. Some affiliates offer family advocate services; mentors for adults in recovery; and education for those working in the mental health professions.
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More than 54 million Americans are afflicted by some sort of mental illness each year, defined as an illness that causes disturbances in thinking, perception and behavior, and that typically harms a person’s ability to cope with ordinary routine. NMHA is committed to changing stigmas associated with mental illness and treatment for the disorders. NMHA also combats the following misconceptions: that younger people do not suffer from mental illness; people so afflicted should be locked up and/or are dangerous; that a person who deals with mental illness will never be completely healthy again; and that those afflicted cannot handle occupations with significant responsibility. SEE ALSO: Anxiety Disorders; Depression; Mental Health. Bibliography. National Mental Health Association,
http://www.nmha.org (cited July 2007); Lorri A. Zipperer, ed., The Health Care Almanac: A Resource Guide to the Medical Field (American Medical Association, 1995).
Kelly Boyer Sagert Independent Scholar
National Network for Immunization Information (NNii) The National Network for Immunization Information (NNii), a service provided by Immunizations for Public Health, provides policy makers, healthcare professionals, the media, and the public with immunization-related material backed up by scientific verification. The goal is to help all populations make quality decisions about immunizations. NNii collaborates with agencies worldwide to effect improved global health through the use of vaccinations, and the organization also focuses on developing, producing, distributing, and using vaccines. NNii does not accept any funding from the government or from the pharmaceutical industry. NNii is an affiliate of a number of medical associations, including the Infectious Diseases Society of America, the Pediatric Infectious Diseases Society,
1202 National Program of Cancer Registries (NPCR) the American Academy of Pediatrics, the American Nurses Association, the American Academy of Family Physicians, the National Association of Pediatric Nurse Practitioners, the American College of Obstetricians and Gynecologists, and the University of Texas Medical Branch. The first vaccination (smallpox) was developed in 1796; currently, there are 11 childhood vaccinations in the United States, plus ones for people traveling to foreign countries (yellow fever) or for people at unique risk (anthrax immunization for professionals who work with animals). Vaccinations currently in development include those combating West Nile virus, severe acute respiratory syndrome (SARS), herpes, human immunodeficiency virus (HIV), Ebola, and respiratory syncytial virus, which can cause bronchitis, plus pneumonia among babies. Although vaccinations are typically associated with childhood in the United States, as many as 60,000 adults die annually in this country from diseases that can be prevented by an immunization. These include tetanus, influenza, and pneumococcal disease; combined, the last two serve as the seventh leading cause of death in the United States. Moreover, diseases such as mumps or chicken pox, if contracted by an adult, are far more likely to present complications. If an adult woman contracts rubella while pregnant, the fetus is at significantly increased risk of being miscarried or stillborn, or if carried to term, to suffer from birth defects. Reasons for unprotected adults include some were not vaccinated as children; new immunizations continually develop; some immunity from vaccinations is reduced over time; and certain diseases impact adults more severely than they do children. More than 90 percent of American children receive immunizations, but fewer than 70 percent of adults are fully protected. In large part, the Vaccines for Children Act, which provides vaccines for children without insurance or underinsured, and state regulations that require vaccinations for schoolaged children cause most children to receive necessary vaccines. To offer similar safeguards for adults, organizations such as the National Coalition for Adult Immunization and the Centers for Disease Control and Prevention (CDC) are increasing educational levels about vaccines and reducing costs.
NNii offers a kit to help healthcare professional provide immunization information to their patients. This kit was created after consulting with immunization and risk experts, along with physicians, nurses, and parents. This agency also provides parents with information to filter out misinformation about vaccines found on the internet, providing quality informational sites as well. SEE ALSO: Adult Immunization; Immunization/Vaccina-
tion; National Immunization Program (NIP); World Health Organization (WHO). Bibliography. National Network for Immunization In-
formation, www.immunizationinfo.org/index.cfm (cited July 2007); Lorri A. Zipperer, ed., The Health Care Almanac: A Resource Guide to the Medical Field (American Medical Association, 1995). Kelly Boyer Sagert Independent Scholar
National Program of Cancer Registries (NPCR) The National Program of Cancer Registries (NPCR), established by Congress through the Cancer Registries Amendment Act of 1992, collects data on cancer, along with its frequency, type, location, severity, and its treatment. Before the establishment of NPCR, 10 states had no cancer registry, and most states with one did not have complete data because of lack of resources. The NPCR, charged with assisting states with data collection efforts, now oversees cancer registries in 45 states, plus the District of Columbia, Puerto Rico, the Republic of Palau, and the Virgin Islands. In turn, the NPCR is overseen by the Centers for Disease Control and Prevention (CDC). NPCR, in conjunction with the National Cancer Institute’s Surveillance, Epidemiology, and the End Results (SEER) Program, collects data throughout the United States, with NPCR supporting data collecting and reporting for 96 percent of the country. The process starts with medical facilities reporting data to a central cancer registry in their state; these data are then forwarded to NPCR or SEER. State
National Women’s Health Organization (NWHO)
data are monitored for cancer frequencies in differing populations; these statistics are used to evaluate the effectiveness of screening, prevention, and treatment programs for a particular cancer in a specific geographical area. This provides states and the federal government direction in allocating funding dollars and directing foci of future research. NPCR provides an example of this process. In two areas of northeastern New Jersey, more than 90 percent of the women diagnosed with breast cancer lived within two miles of a mammography screening center, and the diagnoses were frequently late-stage cancer. By analyzing demographics, NPCR determined that a significant number of people living in this area spoke a language other than English at home; to respond to this discovery, they begin providing information about breast cancer screenings in Arabic, Polish, and Spanish, taking into account cultural sensitivities when producing material. NPCR also provided diversity training to workers at this screening site. Current initiatives of the NPCR include linking registry data with the Indian Health Service’s database; presently, data from Native Americans/Alaska natives is underreported. Another initiative involves developing standardized methods for data transfer from medical centers to state cancer registries and comparing costs of high-quality state registry systems with those that are still substandard to determine the optimal cost-effectiveness registry model. In 2006, CDC and NPCR collaborated to debut WONDER, an online reporting system that provides access to significantly more information to bolster cancer prevention efforts. The organization also released The Breast, Colon, and Prostate Cancer Data Quality and Patterns of Care study, which compared treatment data in 10 central registries. NPCR provides a significant number of publications that can be downloaded from its Web site, and the organization also offers a number of printed informational publications. The agency also collaborates with other relevant organizations, in the areas of the following cancers: breast, cervical, colorectal, hematological, ovarian, prostate and skin, as well as cancer registries, cancer survivorship, and health disparities. SEE ALSO: American Cancer Society (ACS); Cancer (Gen-
eral); National Coalition for Cancer Survivorship (NCCS).
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Bibliography. National Program of Cancer Registries,
http://www.cdc.gov/cancer/npcr/ (cited July 2007); Lorri A. Zipperer, ed., The Health Care Almanac: A Resource Guide to the Medical Field (American Medical Association, 1995). Kelly Boyer Sagert Independent Scholar
National Women’s Health Organization (NWHO) Since 1976, the National Women’s Health Organization (NWHO) has provided American women with medical services that have become increasingly more difficult to obtain in light of the controversy over Roe v. Wade (410 U.S. 113, 1973). NWHO offers a 24-hour emergency call system and prides itself on offering affordable services in a safe and comfortable environment through licensed physicians who specialize in abortion medicine. Licensed anesthesiologists offer patients a choice between general anesthesia and intravenous sedation. In compliance with federal law, NWHO performs first- and second-trimester surgical abortions in clinics and at outpatient ambulatory surgical centers. Early abortions are generally performed by vacuum aspiration, which is considered to be significantly safer than giving birth. Second-trimester abortions are somewhat more complicated and may involve two clinic visits to make the procedure safer and more comfortable. In Raleigh, North, Carolina; Wilmington, Delaware; and Milwaukee, Wisconsin, state laws permit the use of RU486/mifepristone, the so-called French abortion drug that received approval by the Federal Drug Administration (FDA) in 2000. The highly controversial drug, which provides women with nonsurgical abortions, is currently in use in 29 countries around the globe. The Raleigh office also performs tubal ligation, a permanent form of female sterilization which is performed on 650,000 to 700,000 women each year. The procedure, which is performed with a laparoscope, lasts approximately half an hour, and women are dismissed from the clinic a few hours later.
1204 Native-American Health All NWHO patients undergo a battery of lab tests that include hemoglobin, blood typing, sickle cell anemia when applicable, syphilis detection, urinalysis, pregnancy tests when applicable, and Rh factor typing. On some occasions, gonorrhea cultures, Pap smears, and tissue pathologies may be performed. Both pre- and postoperative counseling is provided for all patients, generally in groups of three to four women. Individual counseling is available for patients who need particular attention. During the preoperative sessions, women are informed about procedures and other options are discussed. NWHO national headquarters is located at 3613 Haworth Drive, Raleigh, North Carolina 27609. Information on the organization is available by telephone (1-800-532-5383) or over the internet (www. nwho.org). Clinics are located in Columbus, Georgia; Wilmington, Delaware; Fort Wayne, Indiana; Jackson, Mississippi; Orlando, Florida; Raleigh, North Carolina; Milwaukee, Wisconsin; and Fargo, North Dakota. Because of the high volatility of the abortion issue, NWHO clinics have been faced with more than 30 lawsuits, 18 arsons, and repeated attacks of vandalism. More than 3,000 protestors have been arrested at NWHO clinics. Despite this, 120,000 women have received affordable services through NWHO. The National Women’s Health Foundation has served NWHO as a supporting institution since 1998, funding healthcare for women in underserved areas. Through the Foundation, women who qualify can obtain birth control bills for a small fee and to receive abortions at a reduced price. The emergency response team provides protection at clinics, and the legal team provides legal support for NWHO. ALSO: Abortion; Birth Control/Contraception; Women’s Health (General). SEE
Bibliography. Wendy Chavkin and Ellen Chesler, eds.,
Where Human Rights Begin: Health, Sexuality, and Women in the New Millennium (Rutgers University Press, 2005); Catherine Fisher Collins, ed., African American Women’s Health and Social Issues (Praeger, 2006); National Abortion and Reproductive Rights Action League (NARAL), “RU486,” http://www.prochoiceamerica.org/issues/abortion/medical-abortion/ (cited July 2007); National Women’s Health Organization, http://www.nwho.org; Mary V.
Seeman, ed., National Council of Women’s Organizations, 50 Ways to Improve Women’s Lives: The Essential Women’s Guide for Achieving Equality, Health, and Success (Inner Ocean, 2005); Judith Worrell and Carol D. Goodheart, eds., Handbook of Girls’ and Women’s Psychological Health (Oxford University Press, 2006). Elizabeth R. Purdy, Ph.D. Independent Scholar
Native-American Health Between 2.5 and 4 million Americans are classified as American Indians/Native Alaskans. The lower figure encompasses those who not only report this as their sole race and ethnicity on census forms, but who also maintain an attachment to a tribe or community, and who live on or near a reservation. The larger figure includes those who do not have a formal attachment to a reservation but who claim American-Indian/Native-Alaskan ancestry. The Native-American population, as a whole, is diagnosed with more diseases and disorders than many other racial/ethnic populations in the United States. These health disparities are due to a complex set of factors, including genetic, behavioral, and cultural ones, and are often also attributed to a lack of economic resources to obtain healthcare services and/or to a lack of access to quality healthcare. Native Americans frequently rely upon both westernized medicine and traditional Native-American healing techniques for healthcare; when this type of integrated care is not available, it can prevent some of the population from seeking timely healthcare services. To define the population more specifically, the 2.5 million individuals—or the 0.9 percent of the United States population—who list a wholly American-Indian/Native-Alaskan ancestry are descended from the original people residing in north, south, or central America, and they have kept an affiliation with one of the 569 federally recognized tribes. The majority of these people live in the western, southwestern, or midwestern states, with the greatest numbers living in Alaska, Arizona, Montana, New Mexico, Oklahoma, or South Dakota. The federal government projects that the American-Indian/Native-Alaskan population will
reach over 5 million by 2065, which is estimated to be 1.1 percent of the projected population. Fourteen percent of Native Americans are categorized as being in fair or poor health, with 15 percent having limitations in at least one activity because of a chronic health condition. Thirty-five percent of Native Americans under the age of 65 are without health insurance coverage, and 19 percent of Native Americans over the age of 18 do not report a steady source of healthcare. The 10 leading causes of death for this population, using 2002 figures, are in this order: heart disease; cancer; unintentional injuries; diabetes; stroke; chronic liver disease and cirrhosis; chronic lower respiratory disease, such as emphysema and chronic bronchitis; suicide; influenza and pneumonia; and homicide. Native Americans are 2.6 times more likely to have diabetes mellitus than non-Hispanic whites of similar age, and they have a greater-than-average risk of mental health issues, becoming obese, abusing substances, or having a child die from sudden infant death syndrome (SIDS). To provide for the healthcare of Native Americans and to advocate for their healthcare needs, the United States federal government established an agency, the Indian Health Service (IHS). Through this agency, efforts are made to prevent disease, with initiatives focused on traditional medicine, elder care, women’s health, children and adolescents, injury prevention, domestic violence and child abuse, healthcare financing, state healthcare, sanitation facilities, and oral health. Although this agency was officially granted public health service status in 1988, the federal government had been involved in healthcare legislation for Native Americans for a significantly longer period of time, with mixed results; throughout the early half of the 20th century, healthbased legislation was sometimes used as a tool to attempt to terminate any special racial or ethnic designation for Native Americans. Currently, IHS operates under the auspices of the U. S. Department of Health and Human Services (HSS), providing healthcare services to approximately 1.5 million people. The majority of Native Americans receiving IHS healthcare services live on or near reservations, although some funding has been earmarked to provide healthcare to Native Americans living in cities.
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Approximately 2,700 nurses, 900 physicians, 400 engineers, 500 pharmacists, 300 dentists, and 150 sanitarians work for the IHS, as do nutritionists, health administrators, and medical records personnel. IHS facilities include approximately 150 hospitals, health centers, and healthcare outreach programs. Because of the diversity of the American-Indian/Native-American population and the lack of a strongly coordinated data collection system, it is difficult to provide definitive information about the healthcare needs and status of this population. However, it has been shown that this population is more susceptible to certain health disorders and, ultimately, to certain causes of death. Because of the relatively small NativeAmerican population, which is scattered throughout the country, it has also been difficult to create an effective healthcare system for them. Yet another factor contributes to the difficulties. Traditionally, Native Americans have relied upon a type of healing that differs significantly from the westernized, clinical medicine practiced and used by most other populations in the United States. Some Native Americans do not trust westernized medicine, while others prefer a more integrated form of healthcare that incorporates features of both types of healing methodologies. Traditional Native-American healing takes into account the mind, body, and spirit of an individual, echoing the interconnectedness that he or she perceives in nature and throughout all other aspects of the world. Traditional healers focus more on healing a person and on making him or her whole again than on treating a specific disease. Native-American philosophy teaches that what is good for the group is good for the person, and traditional healing efforts, therefore, also include communal ceremonies led by the healer. Specific health-related ceremonies include the sweat lodge ceremony, talking circles, and spirit camps, and each has been practiced for centuries. As a broad overview of this philosophy, community ties are central to the individuals belonging to the community, traditions are honored, and the preservation of culture is a core group value. Medicine men and women, therefore, want to heal the afflicted, who suffer from physical or psychological/spiritual disorders, but they also want to create preventative measures for the rest of the community, so that they are not also harmed by the illness or disorder. Concepts
1206 Native-American Health such as self-actualization or of an individual awareness can be seen as jarring to Native Americans accustomed to this type of communal healing. Those who provide healthcare services to the Native-American population must keep these cultural values and beliefs in the forefront and respect them to effectively communicate health-related information to them. People accustomed to traditional Native-American healing techniques sometimes struggle to understand westernized medicine, and the reverse can be equally true. To compare the effectiveness of each type of healing, Lewis Mehl-Madrona conducted a longterm study wherein 116 patients received traditional Native-American healing care; researchers then followed up on the health status of the participants and also documented how they perceived the benefits of the traditional form of healing. The results were significant, as Mehl-Madrona reports that more than 80 percent of participants showed long-lasting benefits of significance. Components of traditional medicine that differ from typical westernized medical healthcare include the philosophy that healing takes time and that time itself is healing; that healing takes place with the context of the relationship between the patient and the healer; that positive active energy is needed for healing to occur; that modern devices such as the television, telephone, computer, and so forth interfere with—or inactivate—the catalysts needed for change and for healing; that modern society places a low value on emotions and, in fact, encourages the suppression of them; that physical changes usually need to take place when daily routine have been altered; and that ceremony plays an important role in healing as a way to involve the spiritual dimension. Besides traditional healing techniques and the IHS, other agencies and centers have formed to combat health issues specific to the Native-American population. For the older adult demographic, there is the Native Elder Health Care Resource Center (NEHCRC), created by the Administration on Aging in 1994. The focus of this center is to develop and provide culturally suitable, quality healthcare to the targeted age demographic in the American-Indian, Alaska Native, and Native Hawaiian populations. The four core goals of NEHCRC have been to determine the health status of the targeted populations, to improve the standards for their healthcare, to increase their ac-
cess to care, and to activate relevant community resources. Another relevant agency is the Committee on Native American Child Health (CONACH), which focuses on improving the health status of their targeted population and to increase awareness of the health risks that they face. This agency watches pending legislation that could potentially affect Native-American children; consults with the IHS and other relevant healthcare facilities to advocate for quality healthcare for them; and collaborates with other agencies to effect change. The American Association of Pediatrics (AAP) selects the members to serve on CONACH. At the Center for American Indian and Alaskan Native Health at the Johns Hopkins University School of Public Health, scientists and healthcare experts focus on four key health issues: alcohol and substance abuse; nutrition, diabetes, and obesity; suicide and depression; and injuries. Alcohol abuse is the key focus of another research center located at the University of Colorado at Denver. Researchers there state that 5 of the top 10 causes of death in the Native-American population are directly or indirectly related to alcohol abuse. Using data gleaned from tribes in the Southwest and Northern Plains, deaths from accidents, suicides, homicides, and cirrhosis were shown to occur at least three to four times the typical amount when compared to other populations in the United States. The higher incidence of other health problems, such as kidney and bladder problems, pneumonia, and pancreatitis, were also connected to alcohol dependence in this study. According to the American Psychiatric Association (APA), behavioral health issues and substance abuse also cause significant problems for the NativeAmerican population, and the association specifically noted the increasingly widespread use of methamphetamines. APA experts also state that Native Americans have the highest rates of suicide of any racial or ethnic group in the country. As with doctors treating physical diseases, the APA recommends that psychologists place value on traditional medicine beliefs and philosophies and that they integrate them appropriately to provide quality treatment to the American-Indian/Native-Alaskan population. The APA also states a need for more mental health professionals who are themselves Native Americans.
In part, Native Americans suffer from higher rates of mental illness because of reluctance to seek help; a limited access to quality healthcare; and a general mistrust of this type of treatment. Agencies that provide culturally sensitive assistance for those dealing with mental health issues and substance abuse include the National Center for American Indian and Alaska Native Mental Health Research at the University of Colorado and the One Sky Center, a national resource solely dedicated to substance abuse issues of American Indians/Native Alaskans. A final issue of significance is the health disparity gap. Three decades ago, the National Institutes of Health (NIH) began researching the health disparities of Native Americans and other minorities, citing scientific research that pointed to a complex mesh of contributing factors, including biological, environmental, and behavioral ones, as well as inequities in receiving quality care because of income. In 2000, Congress formed the National Center on Minority Health and Health Disparities to further study these health disparities and then to establish programs to correct these disparities. These disparities are still substantial. As one example, diabetes is significantly more prevalent in the Native-American population than the general one in the United States. According to the American Journal of Public Health, 7.4 percent of American adults have diabetes; when isolating the Native-American population, incidences range anywhere from 22 to 72 percent. Statistics showed that the incidence of diabetes appears to be growing at a rate of 14 percent in the general population, but by 46 percent in some Native-Americans tribes. Furthermore, Native Americans suffer from more complications of the disease, up to and including more frequent amputations. Even more substantial, members of the Pima Indians have the highest incidences of diabetes in the world. The NIH conducted a long-term study with the Pima population living near Phoenix; through this study, scientists have learned a significant amount about the contributing factors of this disease. Asthma statistics point to another significant health disparity. In California, Native Americans have the highest rate of this diagnosis of any racial or ethnic group. Nearly 22 percent of Native-American children and 18 percent of adults have been di-
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agnosed with this disease. Native Americans have the second highest rates of cystic fibrosis of any U.S. population, with Pueblo and Zuni Indians having the highest rates. American Indians and Native Alaskans have high incidences of respiratory syncytial virus (RSV) infection, generally three times higher in their children than typical; SIDS rates are equally as high, with a mortality rate of 123.3 per 100,000. Lung cancer is the most common form of cancer fatalities in the American-Indian/Native-Alaskan population; ironically, most Native-American languages still spoken today do not have a word for this disease. Lung cancer is more common in northern tribes, with 28.5 deaths per 100,000 in reservations located in Montana and Wyoming. More Native Americans smoke than any other ethnic group, with 32 percent currently smoking, which may contribute to the lung cancer prevalence. However, people who participate in a ceremonial use of tobacco are listed as smokers in these data, even if they do not smoke under any other circumstances; therefore, this statistic is most likely skewed. In Alaska, 45.1 percent of the American-Indian/Alaska-Native population is reported to smoke; 44.2 percent are listed as smokers in the Northern Plains; and only 17 percent are reported to smoke in the southwest. In at least two instances, healthcare statistics are more favorable for the Native-American population than the more general one in the United States. First, this group has an exceptionally low incidence of human immunodeficiency virus (HIV)/AIDS, accounting for less than 1 percent of the diagnosed cases in the United States. Second, between 2003 and 2005, the rate of tuberculosis dropped more in the AmericanIndian/Native-Alaskan population than any other, at a 14-percent decrease. SEE ALSO: Alcohol and Youth; Alcohol Consumption;
Alcoholism; Health Care, U.S. and Canada; National Institutes of Health (NIH).
Bibliography. “Many Native American Deaths Linked
to Alcohol,” Alcoholism: Clinical & Experimental Research, http://www.jointogether.org/news/research/summaries/2006/many-native-american-deaths.html (cited July 2007); Lewis Mehl-Madrona, “Traditional (Native American) Indian Medicine Treatment of Chronic Illness: Development of an Integrated Program with Conventional
1208 Naturopathic Medicine/Naturopathy Medicine and Evaluation of Effectiveness,” http://www. healing-arts.org/mehl-madrona/mmtraditionalpaper.htm (cited July 2007); National Library of Medicine, “American Indian Health,” http://americanindianhealth.nlm.nih.gov/ intro.html (cited July 2007); Office on Minority Health, Centers for Disease Control and Prevention, “American Indian & Alaska Native (AI/AN) Populations,” http://www.cdc. gov/omh/Populations/AIAN/AIAN.htm (cited July 2007); U.S. Department of Health and Human Services, “Indian Health Service,” http://www.ihs.gov/PublicInfo/PublicAffairs/Welcome_Info/IHSintro.asp (cited July 2007). Kelly Boyer Sagert Independent Scholar
Naturopathic Medicine/ Naturopathy Naturopathic medicine is a distinctly licensed medical profession in the United States. Practitioners are known as Naturopathic Physicians, Naturopathic Doctors, or Doctors of Naturopathic Medicine, abbreviated as ND or NMD It is a “vitalistic” profession, meaning its core organizing principle is a strong belief in the healing power of nature. History Naturopathic medicine traces its philosophical and therapeutic origins primarily to the hydrotherapy and nature cure traditions of Germany in the 19th century and secondarily to healing traditions from throughout the world. Naturopathic medicine as a profession in North America was established by Benedict Lust in 1896, growing in stature and popularity and peaked in the 1920s-1930s. With the successes of conventional medicine in the mid-20th century and the discovery of antibiotics, coupled with active political suppression, the profession declined and nearly died out in the 1960s (Cody). The environmental movement, vegetarianism, disenchantment with conventional medicine, and leadership from a few key individuals resulted in reemergence in the late 1970s. John Bastyr, ND, DC (1912-1995) was instrumental in the resurgence of naturopathic medicine and is considered the forefather of modern naturopathic
medicine. Responding to the growth in student interest, three naturopathic colleges were established in Arizona, Oregon, and California between 1977 and 1980; none survived. In 1978 the John Bastyr College of Naturopathic Medicine (later renamed Bastyr University) was formed in Seattle, Washington. Founding president Joseph E. Pizzorno, Jr., N.D. promoted “science-based natural medicine” to provide a philosophical foundation for the reemergence of naturopathic medicine. Principles Philosophically, Naturopathy is not identified with any particular therapy but rather by its approach to the patient and support of the body’s natural healing systems. These concepts provide the foundation of naturopathic medicine and guide naturopathic understanding of health and disease. Belief in the ability of the body to heal itself—the vis medicatrix naturae (the healing power of nature)—if given the proper opportunity is fundamental to naturopathic practice and philosophy. In 1989 the American Association of Naturopathic Physicians unanimously approved an updated definition of naturopathic medicine and principles (Snider). The core principles of naturopathic medicine are: 1. The healing power of nature (vis medicatrix naturae) 2. First do no harm (primum non nocere) 3. Find the cause (tolle causam) 4. Treat the whole person (holism) 5. Preventive medicine 6. Wellness (proposed) 7. Doctor as teacher (docere) To help practitioners to more deeply understand and most effectively treat their patients in a curative manner, the “Therapeutic Order” (Zeff ) was developed to conceptualize a hierarchy of treatment, derived from Hippocrates’ writings and ensuing medical scholars. 1. Re-establish the basis for health 2. Stimulate the vis medicatrix naturae. 3. Tonify and nourish weakened systems 4. Correct structural integrity
Naturopathic Medicine/Naturopathy
5. Prescribe specific substances and/or modalities for specific conditions and biochemical pathways, e.g. botanicals, nutrients, acupuncture, homeopathy, hydrotherapy, counseling 6. Prescribe pharmaceutical substances 7. Use radiation, chemotherapy, surgery Modern Naturopathic Practice Primary care, generalist physicians that are trained in natural family medicine utilizing the principles of Naturopathic Medicine. Depending on the state of licensure, primary care physician designation and scope of practice varies (Dunne). Most naturopathic physicians practice primary family care, while others specialize in specific therapies or populations. Less often, naturopathic physicians specialize in clinical areas such as cardiology, gastroenterology, immunology, or environmental medicine. Standard diagnostic tools such as physical examinations, radiology, and serology are used. Some utilize nonstandard diagnostic approaches such as nutritional status evaluation, physiological function measurement, detoxification competency, intra and extra-cellular toxin load, and others. Preference is given to natural therapeutics, though modern naturopathic education calls for appropriate use, referral and consultation with conventional medicine approaches and providers when need arises. The most commonly used treatment modalities include diet and therapeutic nutrition, herbal medicine, homeopathic medicine, hydrotherapy, physical therapy, detoxification, and counseling. Naturopathic medicine is currently licensed in 16 states in the United States and five provinces in Canada (Albert). Licensure efforts are underway in other states, often opposed by self-proclaimed ‘naturopaths’ without requisite education (Baer). The American Association of Naturopathic Physicians is the national professional organization. The Council on Naturopathic Medical Education (CNME) is recognized by the U.S. Department of Education for the accreditation of naturopathic medical schools. The Naturopathic Physicians Licensing Examination (NPLEx) maintains a nationally recognized standardized test for licensing and is recognized by all states licensing naturopathic medicine. Several states now have mandated insurance coverage for licensed naturopathic physicians.
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Education Naturopathic doctorate programs require a bachelors-level premedical education. The four-year graduate program resembles conventional medical education in its education in basic sciences and diagnosis, largely in the first two years of graduate education. Clinical education is focused on pharmacognosy (pharmacology of herbal medicines), botanical medicine, diet therapy, therapeutic nutrition, botanical medicines, homeopathy, environmental health, acupuncture, natural childbirth, hydrotherapy, fasting, physical therapy, exercise therapy, pharmacology, counseling, and lifestyle modification. Postgraduate residencies are currently optional; two states require residency training for licensure. Research All naturopathic institutions engage in some level of laboratory or clinical research. Some institutions have large departments with many ongoing studies as well as NIH-funded clinical trials, basic science research, and training programs. While naturopathic institutions are now regularly publishing study results, the medical research establishment as a whole has substantially increased research in natural therapies. A clinically relevant compilation of this research can be found in the Textbook of Natural Medicine, considered authoritative in the field (Pizzorno). SEE ALSO: Alternative Medicine; Homeopathy. Bibliography. D.P. Albert and D. Martinez, “The Supply
of Naturopathic Physicians in the United States and Canada Continues to Increase,” Complementary Health Practice Review (v.11/2, 2006); H.A. Baer, “The Sociopolitical Status of U.S. Naturopathy at the Dawn of the 21st Century,” Medical Anthropology Quarterly (v.15/3, 2001); G. Cody, “History of Naturopathic Medicine: History of Natural Medicine,” A Textbook of Natural Medicine, J.E. Pizzorno and M.T. Murphy, eds. (John Bastyr College Publications, 1985); N. Dunne, et al., “Naturopathic Medicine: What can Patients Expect?” The Journal of Family Practice (v.54/12, 2005); H. Hough, C. Dower, and E. O’Neil, Profile of a Profession: Naturopathic Practice, ( Center for the Health Professions, 2001); J.E. Pizzorno and M.T. Murray. A Textbook of Natural Medicine, 3rd edition, (Churchill Livingstone, 2005); P. Snider and J. Zeff, Report of the Select Committee on the
1210 Nauru Definition of Naturopathic Medicine. (American Association of Naturopathic Physicians, 1988); J.L. Zeff, P. Snider, and S. Myers, “A Hierarchy of Healing: The Therapeutic Order The Unifying Theory of Naturopathic Medicine,” A Textbook of Natural Medicine, 3rd ed., J.E. Pizzorno, and M. Murray, eds. (Churchill Livingstone, 2005). Joseph E. Pizzorno, ND SaluGenecists, Inc. President Emeritus, Bastyr University Ather Ali, ND, MPH Yale Prevention Research Center Yale School of Medicine
Nauru Located in the southern Pacific Ocean south of the Marshall Islands, Nauru is the world’s smallest independent republic with a total land area of 13 square miles. Nauru’s importance has long been its rich phosphate deposits, and the export of phosphates has been the linchpin of the economy. That resource is expected to fail by the 2020s, and the government has diverted portions of the current export profits into a trust to cushion the blow of the loss. Borrowing from that trust has brought the government to the brink of bankruptcy, leading to a freeze on most expenditures, including hospitals, state employee wages, and crumbling infrastructure. The current population is 13,300 with population growth at 1.81 percent annually. This may drop in coming years as the phosphate mines are fully played out; unemployment now stands at 90 percent. Over a century of mining has left a huge environmental mess in its wake, and less than 600 acres of the island are available for cultivation. As a result, everything on the island—including most of the drinking water—has to be shipped in from Australia and other Pacific countries. Life expectancy is currently 60 years for males and 67 years for females. Infant mortality is 12.7 deaths per 1,000 live births; under-5 mortality is 19.1. Maternal mortality is low, with 100 percent of women receiving prenatal care and giving birth under the supervision of a trained attendant. Common infectious diseases have been mostly eradicated on Nauru. There were three new cases of
leprosy diagnosed in 2002 and three cases of tuberculosis in 2003. There were no reported cases of HIV or AIDS. All Nauruans have access to clean water and adequate sanitation. Noncommunicable diseases such as diabetes and hypertension are the leading health problems for Nauruans. Obesity rates are high. The island has the highest diabetes rate in the world, with 30.2 percent of the population suffering from the disease. Dealing with the crisis has become a major focus of the Ministry of Health, which has plans for an island-wide campaign focusing on healthy eating and lifestyle choices. It is also trying to finance more medical services for those suffering from these types of chronic health conditions. The population is served by a general hospital and a primary care center. The Ministry of Health reports five doctors, 48 nurses, two midwives, and 180 other medical support staff working on the island. Fifty percent of medical personnel are expatriates. Healthcare is free to all Nauruans. SEE ALSO: Diabetes; Healthcare, Asia and Oceania;
Obesity.
Bibliography. The Burton Goldberg Group and Burton
Goldberg, Alternative Medicine: The Definitive Guide (Future Medicine Publishing, 1998); “Nauru,” CIA World Factbook, www.cia.gov (cited July 2007).
Heather K. Michon Independent Scholar
Nausea and Vomiting Nausea and vomiting are symptoms rather than diseases. They can result from many different conditions, such as infection, food poisoning, motion sickness, overeating, intestinal obstruction, brain injuries, appendicitis, and migraine headaches. They can also be symptoms associated with more serious medical conditions such as heart attacks, central nervous system disorders, kidney and liver diseases, and cancer. Nausea is the subjective feeling of the need to vomit; however, it does not always lead to vomiting. Vomiting, or emesis, is the forcible voluntary or involun-
tary oral expulsion of upper gastrointestinal contents due to contraction of the gut and thoracoabdominal wall musculature. There are many activators of emesis and these stimuli can act at several anatomic sites. Emesis provoked by noxious stimuli, such as thoughts or smells, originates in the cerebral cortex. Cranial nerves are responsible for the gag reflex that results in emesis. Motion sickness and inner ear disorders act on the labyrinthine apparatus and vestibular system. Gastric irritants and anticancer medications that induce emesis stimulate the gastroduodenal vagal afferent nerves. Bowel obstruction or ischemia causes emesis through the stimulation of nongastric visceral afferent nerves. The chemoreceptor trigger zone in the medulla responds to blood-borne emetic stimuli. Neurotransmitters that induce emesis are selective for these anatomic sites. Labyrinthine disorders stimulate vestibular cholinergic muscarinic and histaminergic receptors. Gastroduodenal vagal afferent stimuli activate serotonin receptors. The chemoreceptor trigger zone has several receptor types, including serotonergic, cholinergic, histaminergic, and dopaminergic. The differential diagnosis for nausea and vomiting is quite diverse. Conditions within and outside the gut as well as drugs and toxins can be responsible. Intraperitoneal disorders such as visceral obstruction and inflammation may produce vomiting. Gastric obstruction results from ulcer disease or cancer, whereas intestinal obstructions are typically due to adhesions, tumors, volvulus, intussusception, or inflammatory bowel disease such as Crohn’s disease. The most common cause is duodenal ulcer disease, followed by functional dyspepsia and irritable bowel syndrome. Pregnancy is another common cause of temporary nausea and vomiting. Infectious and inflammatory diseases such as appendicitis, pancreatitis, and hepatitis can also cause nausea and vomiting. Rare metabolic diseases such as diabetic ketoacidosis, renal tubular acidosis, hypercalcemia, and adrenocortical insufficiency may also present with these symptoms. Drug-induced nausea should always be considered. Common offensive agents include nonsteroidal antiinflammatory drugs (NSAIDs), opiates, antibiotics, hormone preparations, and chemotherapeutic agents. Obviously, different diseases can present with different symptoms, so diagnosis based upon gastroin-
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testinal symptoms alone can be difficult. Other symptoms such as anorexia, weight loss, and abdominal pain must be taken into account. Temporal relations are also important clues to the underlying etiology. A detailed history and physical exam is key to finding the cause of nausea and vomiting. Symptoms must be identified as acute or chronic. Hematemesis, or vomiting blood, raises suspicion of ulcer disease, MalloryWeiss tears, or malignancy. Feculent material in the vomit is present with more distal obstruction. Fevers suggest the presence of an infectious source. Headaches and visual changes may occur with an intracranial source. Malignant disease is rare under the age of 45 years. It is reasonable to manage younger patients at initial presentation with trial medications and advice regarding lifestyle modification such as diet, weight reduction, smoking, and alcohol cessation. If symptoms persist, however, they should be evaluated further. Testing for H. pylori infection should be one of the first tests done to exclude infected duodenal ulcers. Patients over the age of 45 are likely to have organic pathology. Testing for H. pylori is less useful in this age group because it is very common, therefore, not specific. All patients aged over 45 with symptoms persisting more than four weeks should be referred for investigation. Diagnostic testing aids in the clinical management of the patient with gastrointestinal symptoms. Finding electrolyte abnormalities such as hypokalemia or metabolic alkalosis warrants electrolyte replacement. Detecting iron-deficiency anemia should prompt a search for mucosal injury or gastrointestinal bleeding. Abnormal pancreatic or liver enzymes may suggest pancreaticobiliary or hepatic disease. Specific hormone and serotologic testing can be done when looking for endocrinologic, rheumatologic, or paraneoplastic disorders. Abdominal radiographs are appropriate in the setting of suspected obstruction or ileus. Upper endoscopy is useful for the detection of ulcers and malignancy whereas small-bowel barium radiography is more useful for detecting smallbowel obstruction. Colonoscopy or contrast barium enemas are useful for detecting colonic obstruction or malignancy. Abdominal ultrasound or computed tomography (CT) is useful for detecting intraperitoneal inflammatory diseases. If intracranial sources are suspected, CT or magnetic resonance imaging (MRI)
1212 Neck Disorders and Injuries of the head is warranted. If mesenteric ischemia is suspected, mesenteric angiography or MRI should be performed. If anatomic abnormalities are not found, gastric motility studies may be helpful. Treatment of nausea and vomiting should ideally involve identifying and treating the underlying cause. Hospitalization may be required in cases of severe dehydration, especially if the patient cannot tolerate oral fluid replenishment. An understanding of the pathophysiologic pathways involved in nausea and vomiting is necessary to direct medical treatment. The most commonly used antiemetic agents act centrally on the nervous system. Antihistamines block the actions of histamine at the receptor and anticholinergic agents block the actions of acetylcholine at the muscarinic receptor. Both drug classes act to limit the stimulation of the vomiting center from the vestibular system. Dopamine antagonists block the effects of dopamine at the receptors in the chemoreceptor trigger zone, which limits stimulation at the medullary vomiting center. Selective serotonin antagonists block the actions of serotonin on the receptors in the small intestine, vagus nerve, and chemoreceptor trigger zone. This also decreases stimulation at the medullary vomiting center. SEE ALSO: Cancer (General); Gastroenterology. Bibliography. William L. Hasler, “Nausea, Vomiting,
and Indigestion,” Harrison’s Principles of Internal Medicine, http://online.statref.com (cited September 2006); R.C. Spiller, ABC of the Upper Gastrointestinal Tract: Anorexia, Nausea and Vomiting, BMJ.com (cited September 2006). Christina Murray, MSVI Angela Garner, M.D. University of Missouri-Kansas City
Neck Disorders and Injuries The human neck is a very mobile and complex structure, and as such is prone to injury. Disorders of the neck are generally due to trauma or disease processes that lead to compression or other compromise of vital structures, especially the nerves and spinal cord.
Neck trauma with resulting damage to the spinal cord is not the most common neck injury, but it is one of the most serious because of the potentially devastating consequences. The flexibility of the cervical spine places it at an increased risk for potential injury. Dislocated or fractured vertebra may compress or sever the spinal cord and in extreme cases the resulting damage may cause quadriplegia (paralysis of all 4 limbs), with even an inability to breath without a respirator, or death. In the United States, about 10,000 spinal cord injuries occur every year. About 80 percent occur in men under 35 years of age. Motor vehicle accidents cause 45 percent of theses injuries, 20 percent are from falls, 15 percent from sports injuries, and 15 percent from violence. The fact that young men suffer the majority of spinal cord injuries and that risky behavior is often involved (unsafe driving, diving into shallow water, playing contact sports) emphasizes the importance of prevention in the management of spinal cord injury. Such preventive measures include safety belts, airbags and protective athletic equipment, but education is perhaps the simplest and most important. In fact, the first recommendation from a commission aimed at reducing football spinal cord injuries was teaching safe contact techniques. Once a spinal cord injury has occurred, recognition is crucial. Prompt immobilization of the neck reduces the risk of further injury. Frequently, surgical intervention is necessary. In these cases the goal is to decompress the spinal cord, realign the cervical spine, and restore spinal stability. Depending on the location of the compression either an anterior procedure (i.e. discectomy) or a posterior procedure (i.e. laminectomy) may be necessary. Stabilization typically requires bone graft to achieve a fusion. Plates and screws may be necessary to provide initial stability. Fortunately, traumatic spine injuries resulting in paralysis are uncommon, and injuries that result in pain, loss of range of motion, and varying neurologic symptoms are more typical. At any given time, 15 percent of adults suffer from neck pain. Whiplash injuries are typically the result of a strong extension and strong flexion of the cervical spine, as is the case when hit from behind in a car. Such a violent episode can result in a variety of soft-tissue injuries that may cause symptoms, such as neck, shoulder, or back pain, stiffness, headache, dizziness, and abnormal sensations such
as burning or prickling (paresthesias). Early mobilization is associated with better outcome, but persistent symptoms and resistance to treatment are common. Herniated discs are rarely due to a single traumatic event but typically due to repetitive use injury, postural problems, and degenerative disease. The inner part of the disc (nucleus pulposus) bulges through the surrounding outer part of the disc (annulus fibrosus) and can compress a nerve root (“pinched nerve”) as it exits the spinal column. The most common location for this nerve compression to occur is between cervical vertebra 6 and 7. Such an occurrence compresses the 7th nerve, resulting in potential pain in the neck and shoulder as well as tingling into the index and middle finger. An associated physical finding is worsening of the pain when bearing down (such as when coughing or sneezing) because this increases the pressure in the spinal column. First line treatment includes anti-inflammatory medications and physical therapy; however, decompressive surgery is often indicated in those that don’t respond. Several disease processes are grouped under the term “cervical spondylosis” or degenerative arthritis. Although in selected individuals it can cause neck pain and dysfunction, its general significance as a cause of pathology is still unknown. This is because radiographic evidence of degenerative arthritis can be present in up to 90 percent of men older than 50 years and women older than 60 years; however, symptoms are not always present. Rheumatoid arthritis is one specific cause of arthritis. It is a chronic systemic inflammatory disease that targets the lining membranes of multiple joints. It is an autoimmune process that affects women more than men and is marked by diffuse warmth and pain that is worse in the morning. There is diffuse joint erosion and when rheumatoid arthritis affects the neck it can lead to chronic instability of the atlantoaxial joint. This joint, which lies between the first and second cervical vertebral bodies, is responsible for rotation of the head. Its deterioration and dislocation can lead to spinal cord injury and may require surgical stabilization. Ankylosing spondylitis is a progressive, systemic, inflammatory arthritic condition that mainly affects the spinal column and sacrum. It is a spondyloarthropathy, mainly occurring in males and highly as-
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sociated with the HLA-B27 antigen. The extent of the disease varies between individuals. Oftentimes, ankylosing spondylitis affects the cervical spine, noted with mass inflammation of the joints and ligamentous structures with extensive ossification (bone formation) of the vertebral motion segments. Extensive and long-standing ankylosing spondylitis creates a rigid deformity of the spine, affects posture and forward vision, and renders the bony spine “brittle” in composition; thereby, increasing the spine’s susceptibility to injury. As such, cervical spine fracture following even a minor traumatic event has been noted to occur in individuals with ankylosing spondylitis. Such an injury can lead to severe spinal cord injury and/or death. Osteoarthritis is another degenerative process, marked by thinning of cartilage and narrowing of the disk space, which can be seen on x-ray. It is not an inflammatory process and there are no systemic symptoms as there are in rheumatoid arthritis or ankylosing spondylitis. However, proliferations of bone at the margin of the vertebral body called osteophytes can impinge on nerves, leading to numbness, clumsiness, or pain in areas supplied by the affected nerve. There are other conditions that compromise the function of structures in the neck. Thoracic outlet syndrome occurs when nerves and arteries and veins are compressed as they exit the neck. The carotid arteries, which supply blood to the head, are often compromised by atherosclerotic disease. Lymphadenopathy, or swelling of the lymph nodes, whether due to infection as in infectious mononucleosis (EpsteinBarr virus) or leukemias or lymphomas may lead to difficulty swallowing. Other cancers (myeloma or metastatic tumor) may degenerate bone and lead to cervical fractures and their associated complications. Infection can also lead to bone degeneration (osteomyelitis) or neck stiffness and pain in the case of meningitis, which is an infection of the lining of the brain and spinal cord. Various congenital conditions exist that may alter the normal structure and function of the cervical spine, increasing the risk of neurologic injury. For example, such conditions may entail Klippel-Feil syndrome, fibrodysplasia ossificans progressiva, osteogenesis imperfecta, and Down’s syndrome. The risk of potential neck injury regarding these conditions varies, but nonetheless necessitates awareness.
1214 Neonatologist SEE ALSO: Arthritis; Cervical Spine; Down Syndrome;
Immune System and Disorders; Immunology; National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS); Orthopedics; Orthopedist; Osteoarthritis; Osteogenesis Imperfecta; Rheumatoid Arthritis; Spinal Cord Injuries. Bibliography. Howard S. An, “Cervical Spine Trauma,”
Spine (v.23, 1998); John D. Heckman, Animesh Agarwal, and Robert C. Schenck, Current Orthopedic Diagnosis & Treatment (McGraw-Hill, New York, 2006); Francis H. Shen and Dino Samartzis, “Surgical Management of Lower Cervical Spine Fracture in Ankylosing Spondylitis,” Journal of Trauma: Injury, Infection, and Critical Care (v.61, 2006); Francis H. Shen, Dino Samartzis, Louis G. Jenis, and Howard S. An, “Rheumatoid Arthritis: Evaluation and Surgical Management of the Cervical Spine,” The Spine Journal (v.4, 2004). Elliot P. Robinson University of Virginia Dino Samartzis, DSc, MSc, Dip. EBHC Harvard University and Erasmus University Francis H. Shen, MD University of Virginia
Neonatologist A neonatologist is a specialized physician that treats premature and full-term infants who may have lifethreatening disease or complications. ��������������� Neonatologists have the special training required to evaluate and treat newborns’ disorders or possible problems. For ���� example, if a newborn is premature or has a serious illness, injury, or birth defect, a neonatologist may assist at the time of delivery and in subsequent care. If a problem is identified before the child is born, a neonatologist may become involved to consult with the obstetrician and patient during pregnancy. The training for a neonatologist is intense with medical university and postgraduate training that can last up to 12 to 15 years. Many developing nations do not have adequate postgraduate training programs to offer the specialization of neonatology. The outcome is a lack of proper diagnosis and treatment of common premature and newborn pathologies.
Neonatologists stabilize and treat newborns with life-threatening medical problems. They can provide medical care with the diagnosis and treatment of newborns with conditions ranging from breathing disorders and infections to congenital birth defects. They will make sure that critically ill newborns receive proper nutrition for healing and growth. Neonatologists work mainly in special care nurseries or newborn intensive care units of hospitals. In some cases, after a newborn has been discharged from hospital, a neonatologist may provide short-term follow-up care. This follow-up care may not be available in many regions of the world with a lack specialized and primary care access. SEE ALSO: American College of Physicians (ACP); Infant
and Newborn Care; Infant and Toddler Health; Pediatrics.
Bibliography. John P. Cloherty and Ann R. Stark, eds.,
Manual of Neonatal Care, 5th ed. (Harvard Medical School, Beth Israel Hospital, Brigham and Women’s Hospital, and Children’s Hospital, 2003). John M. Quinn V, M.P.H. University of Illinois at Chicago
Neonatology Neonatology is a subspecialty of pediatrics, dealing with the medical care of newborn infants, especially ill or premature infants. A newborn is a recentlyborn infant, usually considered a newborn for the first few hours of life. An infant is considered neonate in the first 28 days of life, and this period is considered critical to a healthy start in life. It is during this time that fundamental health and feeding practices are established. It is also during this time that the child is at highest risk for death. Neonatology is a hospital-based specialty, and is usually practiced in neonatal intensive care units (NICUs). The principal patients of neonatologists are newborn infants who are ill or requiring special medical care, due to prematurity, low birth weight, intrauterine growth retardation, congenital malformations (birth defects), sepsis, or birth asphyxia. Abroad, health facilities are expected to provide care to two groups of
newborn infants; those who are delivered there and are mostly healthy, and those who are brought to the health facility from the community because of illness. Using simple but scientifically sound principles of care, as well as equipment and supplies, it is possible to treat most neonates at first-level facilities. Of the 7.1 million infants who die each year, approximately two-thirds die in the first 28 days after birth—the neonatal period. Of these deaths, two-thirds take place in the first week after birth. Ninety-eight percent of all neonatal deaths occur in developing countries. Little is known about the actual impact and costs of maternal and newborn ill-health and death at the individual, familial, and societal level and their effect on poverty. The global status of maternal and newborn health provides one of the most striking examples of disparity between rich and poor countries.Improving newborn survival will dramatically reduce infant mortality worldwide. Although there were some efforts to care for sick infants in the early 1900s, there was a rapid escalation in the services in the 1960s with the advent of mechanical ventilation of the newborn. This allowed for survival of smaller and smaller newborns. Today newborns as small as 450 g (1 lb) and as early as 22 weeks gestation have a small chance of survival. Infants weighing 1,000 g and at 27 weeks gestation have an approximately 90 percent chance of survival and the majority have normal neurological development. One of the aims of the Infant and Neonatal Health (HNI) team within the World Health Organization (WHO) Department of Child and Adolescent Health and Development (CAH) is to reduce infant mortality and to ensure that newborns and infants have the opportunity for a healthy start in life. Studies clearly indicate that countries with high maternal, perinatal, and neonatal mortality have inadequate and poorquality health services and this can be associated with reduced utilization of healthcare services. As such, increased emphasis is being placed on the need for standards of care, as well as mechanisms that address the barriers to provision and use of quality care. Evidence also suggests that explicit, evidencebased guidelines improve the process and outcomes of healthcare when appropriately implemented.Success in reducing neonatal mortality requires many components: caring families, availability of adequate
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healthcare, ability to recognize when a sick child needs professional care, good nutrition, and support from communities. It is also important that every pregnant woman has adequate prenatal care. This includes having at least four prenatal visits with an appropriate healthcare provider, and receiving the recommended doses of the tetanus toxoid vaccination. The mother also needs support from her family and community in seeking care at the time of delivery and during the postpartum and lactation period. In general, neonates who are born at facilities have a much better chance for survival than those born at homes. Access to skilled providers and services during labor, at birth, and in the postnatal period ensures that complications are prevented and readily treated should they occur. Therefore, it is recommended that when possible, deliveries take place at health facilities and not at homes. This becomes absolutely essential if the pregnancy is high risk. In this situation, the lives of both the mother and the newborn depend on the expert care that can only be provided in a well-equipped facility.Most infants born at the facility are healthy. Their needs include warmth, early and exclusive breast feeding, hygiene, and cord, skin, and eye care. They should be nursed with the mother. The role of the health worker is to support the mother and the family and to observe the baby for complications. The most common illness for which neonates are admitted to facilities is sepsis, manifesting as septicemia, pneumonia, or meningitis. Other conditions requiring care at facilities include birth asphyxia, birth trauma, seizures, and hyperbilirubinemia. A crucial role of the facilities is to provide care to sick and low birth weight (LBW) neonates. Low birth weight has been defined by WHO as weight at birth of less than 2,500 g (5.5 lb). This is based on epidemiological observations that infants weighing less than 2,500 g are approximately 20 times more likely to die than heavier babies. More common in developing than developed countries, a birth weight below 2,500 g contributes to a range of poor health outcomes. More than 20 million infants worldwide, representing 15.5 percent of all births, are born with low birth weight, 95.6 percent of them in developing countries. The level of low birth weight in developing countries (16.5 percent) is more than double the level in
1216 Nepal developed regions (7 percent). LBW neonates often need special facility care because of their inability to feed from the breast or cup/spoon, inability to maintain temperature, or added complications such as apnea and respiratory distress. Optimal care of neonates requires the presence of two specific treatment areas in a facility, namely, a resuscitation area in the delivery room to provide care at birth and a newborn care area in the inpatient ward where sick and LBW infants are nursed. The Standards for Maternal and Neonatal Care consists of a set of user-friendly leaflets that present WHO key recommendations on the delivery of maternal and neonatal care in health facilities, starting from the first level of care.Facilities at higher levels of care should also have these standards in place as a minimum (essential) care for all mothers and babies; in addition, they should have standards for the care of women and newborns in need of obstetric and special care. The Standards for Maternal and Neonatal Care are part of the WHO Integrated Management of Pregnancy and Childbirth Care (IMPAC) package, which provides guidance for assisting countries to improve the health and survival of women and their newborn babies during pregnancy, childbirth, and the postnatal period. SEE ALSO: Infant and Newborn Care; Infant and Toddler
Development; Infant and Toddler Health; Neonatologist; Pediatrics; Pregnancy; Pregnancy and Substance Abuse; Pregnancy Loss; Premature Babies; Prenatal Care. Bibliography. M. Finster, “The Apgar Score Has Survived
the Test of Time,” Anesthesiology (v.102/4, 2005); Steven G. Gabbe, Obstetrics—Normal and Problem Pregnancies, 4th ed., (Churchill Livingstone, 2002); Robert E. Rakel, Textbook of Family Practice, 6th ed. (Saunders, 2002); Abraham M. Rudolph and Colin D. Rudolph, Rudolph’s Pediatrics, 21st ed. (McGraw-Hill, 2003). Barkha Gurbani University of California, Los Angeles
Nepal Nepal is a landlocked country in the Himalayan mountains, straddling East and South Asia. Roughly
the size of Arkansas, Nepal is home to seven of the planet’s fourteen highest peaks, including Mount Everest, which lies on the border with China. The monarchy was destabilized in 2001 after the heir apparent to the throne went on a shooting rampage in the royal palace and killed his parents and several other members of the family before killing himself. Maoist insurgents used the resulting chaos to stir up unrest among the people, and in 2006 the new king, Gyanendra, announced he was ceding absolute power and called for the formation of a new government. The population is 28,900,000 and growing at a rate of 2.132 percent annually. The birth rate is 30.46 per 1,000 and the death rate is 9.14 per 1,000. Median age is 20.5 years. Life expectancy is 61.87 years for males and 65.54 years for females. Gross national income is $270 per person, with 24 percent of the population living on less than $1 a day. Nepal has one of the world’s most underdeveloped economies, and lacks a skilled, literate workforce. Almost 80 percent of Nepalese get by on subsistence agriculture. Health statistics are incomplete and record-keeping is poor. About 90 percent of people have access to potable water, although 15 percent of wells are polluted by arsenic. Only 35 percent have hygienic latrines. Malaria and tuberculosis are common, along with leishmaniasis, a chronic and often fatal parasitic disease transmitted by sand fleas that causes inflammation of the internal organs. There are also believed to be high rates of Japanese enchephalitis and filariasis. The adult prevalence rate for HIV/AIDS is 0.5 percent, with about 75,000 cases country-wide. However, there is no national coordinating body for AIDS treatment or prevention. Morbidity is driven by skin diseases, diarrhea, acute respiratory infections, intestinal worms, fevers of unknown origins, ear infections, chronic bronchitis, anemia and abdominal pain. Leading causes of death are pneumonia, cardiovascular disorders, encephalitis and meningitis, septicemia, and diarrhea. Illness and death from non-communicable disease is rising, largely from preventable causes such as drug and alcohol abuse and tobacco use. In rural areas, a 2001 study found that 85.4 percent of males over 15 and 62.4 percent of females over 15 used tobacco. Child mortality is almost half of what it was in 1990, with 56 deaths per 1,000 in infants and 74 per 1,000 in children under 5. Malnutrition is believed to be the
Nephrologist
underlying cause in up to 60 percent of deaths in childhood, with 50 percent of under-5s classified as underweight and 51 percent showing signs of stunting. Thirty percent of children between the ages of 5-14 are in the labor force. The Maoist insurgency and teacher strikes have closed many schools throughout Nepal, and those that remain open sometimes turn into indoctrination centers, where children are absorbed into militias. Quality of life for Nepalese women is generally poor. The literacy rate for females older than 15 is 35 percent. At least 200,000 women (including an estimated 7,000 young girls a year) are trafficked into sexual slavery in India. About 60 percent of rural girls and 34 percent of urban girls are married in childhood, sometimes as young as 8. The total fertility rate is 4 children per woman. Three-quarters of pregnant women are anemic, and 21 percent of infants are born with low birthweight. Prenatal care is rare, and 11 percent of women give birth with the help of trained assistants. This contributes to a maternal mortality rate of 740 deaths per 100,000 live births. Nepal spends $18.60 per capita on health care each year. The Ministry of Health cites a wide variety of health facilities, including 5 central hospitals and 15,500 “outreach clinics.” There are also specialized and teaching hospitals, and 288 traditional Ayurvedic facilities. Medical personnel is limited, with 0.21 physicians and 0.22 nurses per 1,000. The Ministry notes that there are also 6,000 midwives and 15,000 traditional, trained birth attendents, along with 54,000 “female community health volunteers.” SEE ALSO: Death Rate; Healthcare, Asia and Oceania. Bibliography. “A Guide to Statistical Information at
WHO,” World Health Organization www.who.int/whosis/ en/index.html (cited June 2007); “Child Trafficking/Exploitation—Save the Children Nepal,” International Save the Children Alliance www.savethechildren.net/nepal/key_issues/ trafficking.html (cited June 2007); “Country Health Profile: Nepal,” WHO/Western Pacific Regional Office. www.searo. who.int/LinkFiles/Nepal_nepal.pdf (cited June 2007); “Fact Sheets.” Ministry of Health and Population, Government of Nepal www.moh.gov.np/Home/FACT.ASP (cited June 2007); “Nepal,” CIA World Factbook. www.cia.gov/library/ publications/the-world-factbook/geos/np.html (cited June 2007); “Nepal - Statistics”. UNICEF. www.unicef.org/infoby country/nepal_nepal_statistics.html (cited June 2007); “Ne-
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pal,” UNAIDS: The Joint United Nations Programme on HIV/ AIDS. www.unaids.org/en/Regions_Countries/Countries/ nepal.asp (cited June 2007); “WHO Global InfoBase: InfoBase Home Page,” World Health Organization. www.who. int/infobase/report.aspx (cited June 2007). Heather K. Michon Independent Scholar
Nephrologist A nephrologist is a physician who specializes in the diagnosis and treatment of kidney diseases. Nephrology is a sub-specialty of internal medicine. A doctor of internal medicine, commonly referred to as an internist, diagnoses and treats diseases of the entire adult body. This includes everything from treating ordinary illnesses such as a sinus infection, to dealing with more serious concerns such as diabetes. While a specialist, such as a nephrologist, treats specific illnesses, an internist concerns himself with the prevention of all disease. When the internist is faced with a patient with organ-specific concerns, such as a diabetic with protein in his urine, he refers him to a specialist. In this case the internist refers the patient to a nephrologist. A nephrologist is a physician who after successfully completing the internal medicine residency completes a two-year fellowship program focused around the diagnosis and treatment of kidney diseases. During this fellowship a nephrologist learns how to prevent and treat kidney disorders via controlling a patient’s blood sugar, regulating blood pressure, monitoring body electrolytes, and balancing fluid levels. It is common for a patient to find himself in a nephrologist’s office via a referral from an internist. Common “red flags” that initiate such referrals include blood or protein in the urine, kidney stones, frequent urinary tract infections, etc. A nephrologist will examine such a patient and determine the correct regimen of treatment. For many patients treatment of the underlying condition, such as uncontrolled blood sugars, will rectify the problems. For others, medication might be needed. In extreme cases dialysis or a kidney transplant might be necessary. In summary, a nephrologist is a trained internist who specializes in diseases of the kidneys.
1218 Nephrology SEE ALSO: Dialysis; Nephrology. Bibliography. American College of Physicians, “Inter-
nal Medicine Subspecialties: Nephrology,” www.doctorsforadults.com (cited October 2006); American College of Physicians, “About Internal Medicine,” www.doctorsforadults.com (cited October 2006). Angela J. Garner, M.D. University of Missouri–Kansas City
Nephrology The word nephrology is Greek for “the study of the kidney.” The word kidney is synonymous with “renal” as well as “nephro” and the three terms are commonly interchanged. Nephrology is the branch of internal medicine that focuses on the structure and function of the kidneys—both healthy and sick. A nephrologist is a physician who diagnoses and treats kidney diseases. The Function of the Kidneys Normally, a person is born with two kidneys. Each kidney is bean-shaped and about the size of an adult’s fist—about 4 inches long and 2.5 inches wide. The kidneys are located directly below the rib cage, on either side of the vertebral column. The tasks of the kidneys are numerous. Foremost, these organs are responsible for regulating the composition of the body’s blood. This includes keeping the fluid level in the body constant, regulating the acidity level, balancing the electrolyte concentrations, and removing waste products from the blood. The kidneys receive the body’s blood from the renal artery. The renal artery delivers the blood to specific parts of the kidney called nephrons. The nephron is made of the glomerulus and convoluted tubule. The glomerulus is composed of the capillaries, which are tiny blood vessels involved in the filtration of blood. The convoluted tubule is a tiny tube that collects the waste products from the filtered blood. The filtered blood, which includes sodium, phosphorous, and potassium, exits the kidney via the renal vein and is returned into circulation. The waste products, consisting of urea, toxins, and surplus drugs, exit the kidney and travel to the bladder via the ureter. These waste products are turned into
urine, which is then stored in the bladder until it is released through the urethra. This process is continuous. Without the filtering action of the kidneys a person would die within eight days. In addition, the kidneys are responsible for producing three important hormones: erythropoietin, renin, and calcitriol. The kidneys produce erythropoietin if low oxygen levels are detected in the blood. Erythropoetin then stimulates the production of red blood cells in the bone marrow. Red blood cells are responsible for carrying oxygen in the blood and, therefore, an increase in erythropoietin will ultimately result in an increase in oxygen. Renin is the hormone produced when the kidneys detect low blood pressure, low volume of blood, or decreased salt levels in the body. Production of renin results in the constriction of blood vessels—which increases blood pressure. Renin also stimulates the adrenal gland to make aldosterone—which increases salt concentration in the body. An increase in salt concentration causes more water to be absorbed as well as stimulates the brain to make a person feel thirsty. The final hormone produced by the kidneys is calcitriol. Calcitriol is the active form of vitamin D—which is responsible for calcium reabsorption in the intestinal tract and the bone. What medical tests detect kidney disease? If kidney disease is suspected, a patient’s doctor will perform a blood pressure measurement, check the urine for protein, and take a sample of blood to measure the serum creatinine and blood urea nitrogen (BUN). A blood pressure check is necessary because high blood pressure can cause kidney disease—as well as heart disease and stroke. Proteinuria, protein in the urine, may represent kidney dysfunction because a normal kidney separates protein from waste products. Checking the serum creatinine is an essential part of the exam because it allows for the further calculation of the glomerular filtration rate (GFR). GFR is a calculation in which the result can be used to evaluate kidney function. Lastly, a BUN may be performed. The blood in the body contains protein, which is delivered to cells throughout the body. These cells use the protein as energy and in the process create the byproduct, urea. Urea is then carried to the kidneys where it is filtered out into urine. If a BUN level is high it indicates that the kidneys may not be
Netherlands
efficiently filtering out the urea—another sign of kidney disease. types of kidney disease There are many different types of kidney disease. The following discusses the most common types. • Cystic Disease, known as polycystic kidney disease, is a genetically inherited disorder that results in enlarged kidneys, which contain multiple air-filled cysts. There are two types of inheritance—autosomal recessive and autosomal dominant. The autosome recessive type is more severe and the patient commonly develops renal failure in childhood or infancy. The autosomal dominant type is less severe and the patients are usually asymptomatic until middle adulthood. At the time of diagnosis they present with high blood pressure, blood in the urine, and renal function abnormalities. • Glomerular Diseases are divided into two categories, nephritic and nephrotic, based on the amount of protein present in the patient’s urine. Both types of disorders have a wide range of causes, including: infection, autoimmune diseases, malignancies, and those that are idiopathic, where the cause is unknown. The signs/symptoms of nephritic disease include proteinuria of less than 3.5g/day, blood in the urine, high blood pressure, and decreased urine output. The signs/ symptoms of nephrotic disease include proteinuria greater than 3.5g/day, generalized edema, swelling; hyperlipidemia, such as high cholesterol; and low levels of albumin, or protein, in the blood. • Tubules and Interstitium Diseases: This category includes acute tubular necrosis and acute pyelonephritis. Acute tubular necrosis is the most common cause of acute renal failure in the United States. It is most commonly caused by decreased blood flow to the kidneys resulting from hemorrhage, hypotension, shock, dehydration, or vasoconstriction. Symptoms include lack of urination, an elevated BUN and creatinine, metabolic acidosis, and high levels of potassium in the blood. The damage to the kidney is reversible if the underlying cause is treated. Acute pyelonephritis is a bacterial infection involving the re-
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nal pelvis and tubules. It most commonly occurs from an untreated lower urinary tract infection. Symptoms include fever, chills, frequent urination, painful urination, urination urgency, costovertebral angle tenderness, and overall fatigue. • Urolithiasis (Kidney Stones): Formed by chemicals in the urine that stick together. • Tumors of the Kidney: This includes both benign and malignant tumors. The most commonly known kidney tumor is renal cell carcinoma. • Trauma treatment options Many kidney disorders can be corrected with medication. When kidney function is no longer adequate dialysis may be required. In extreme cases a kidney transplant may be performed. SEE ALSO: Dialysis; Nephrologist.
Georgetown—Department of Medicine—Division of Nephrology and Hypertension, “Patient Education.” http://www.georgetown.edu/departments/ medicine/nephrology/pi_overview.htm (cited October 2006); National Kidney Foundation, “How Your Kidneys Work.” http://www.kidney.org/kidneydisease/howkidneyswrk.cfm (cited October 2006); National Kidney and Urologic Diseases Information Clearinghouse, “Your Kidneys and How They Work.” http://kidney.niddk.nih.gov/kudiseases/pubs/yourkidneys/ (cited October 2006); The Merck Manuals Online Medical Library, “Nephritic Syndrome.” http://www.merck.com/mmhe/sec11/ch144/ch144b.html (cited October 2006); The Merck Manuals Online Medical Library, “Nephrotic Syndrome.” http://www.merck.com/ mmhe/sec11/ch144/ch144c.html (cited October 2006). Bibliography.
Angela Garner, M.D. University of Missouri–Kansas City
Netherlands The Netherlands is the 23rd richest nation in the world, with a per capita income of $30,300. The United Nations Development Programme (UNDP) Human Development Reports rank the Dutch standard of living 10th among nations of the world. The
1220 Netherlands
Virtually all of the Dutch population is covered by Social Security, which provides benefits for retirees, the disabled and children.
Dutch economy tends to be stable, growing at a rate of 1.5 percent; and unemployment (6.6 percent) and inflation (1.7 percent) are well under control. Engaging only 2.1 percent of the workforce, the Dutch agricultural sector is so technologically advanced that it provides products for exports as well as for domestic consumption. Income disparities do exist, and the Gini Coefficient for the Netherlands is 30.9. The top 10 percent of the population control 22.9 percent of all wealth, but the bottom 10 percent hold only 2.5 percent of Dutch resources. Despite the high standard of living and general good health, just over one-tenth of the population lives in poverty. There is ample evidence that the overall health of the poor is below that of more affluent Dutch.
Before January 2006, health insurance in the Netherlands was compulsory for most workers and for the self-employed whose earnings were lower than a designated income level. Higher-earning residents were allowed to choose between private carriers or remaining uninsured. Reforms instituted under the Health Insurance Act, which became effective January 1, 2006, mandated basic medical coverage for the entire population. Residents retained the right to choose carriers and to take out supplementary insurance. Coverage is provided by private companies that are obligated to cover all residents in designated areas. Nominal copayments are required. At the end of a year, those who have filed no insurance claims other than those associated with general medical consultations, maternity care, and children’s healthcare, are entitled to cash rebates. Virtually all of the Dutch population is covered by Social Security, which provides benefits for retirees, the disabled, children, and the unemployed. Employers are required to pay 70 percent of lost wages when employees experience major illnesses. Those whose incomes are below a certain level receive government assistance with normal medical expenses. The Dutch government has a strong commitment to promoting the good health of the citizenry, and health spending comprises 10 percent of the total budget. Allotting $2,987 (international dollars) per capita, 9.8 percent of the Gross Domestic Product (GDP) is used to fund health programs. Government spending comprises 62.4 percent of total health spending, with 20.80 percent earmarked for Social Security. The private sector supplies 37.6 percent of expenditures, and 20.80 percent of that amount is derived from outof-pocket expenses. There are 3.15 physicians, 13.73 nurses, 0.48 dentists, and 0.19 pharmacists per 1,000 population in the Netherlands. The Netherlands ranks 30th in the world in life expectancy, and the population (16,491,461) enjoys a life expectancy of 78.96 years. Women outlive men an average by six years. All of the relevant population is enrolled in school at the primary and secondary levels, and literacy is virtually universal (99 percent). All urban residents have access to safe drinking water and improved sanitation. While 100 percent of the Dutch rural population also has sustained access to improved sanitation, 1 percent of rural residents lacks
access to safe drinking water. Some 79 percent of all females use some method of birth control, and Dutch women give birth at a rate of 1.66 children each. All births are attended by trained professionals, and the adjusted maternal mortality rate is 16 deaths per 100,000 live births. Between 1990 and 2004, infant mortality fell from seven to five deaths per 1,000 live births, and the mortality rate of children under the age of 5 dropped from nine to six deaths per 1,000 live births. Currently, the infant mortality rate is 4.96 deaths per 1,000 live births. Childhood immunization rates are predictably high in the Netherlands, and only 2 percent of infants have not been immunized against diphtheria, pertussis, and tetanus (DPT1 and DPT3) and polio. Three percent have not been immunized against Haemophilus influenzae type B, and 4 percent have failed to receive measles vaccinations. The Netherlands is highly susceptible to flooding that may threaten the health and lives of the people. Industrialization also poses a serious danger. Water sources have been polluted by heavy metals and organic compounds, and the air has been tainted by vehicle emissions and refining activities. HIV/AIDS continues to cause some concern in the Netherlands, which has an adult prevalence rate of 0.2 percent. Around 19,000 people are living with HIV/AIDS, but the disease has proved fatal to fewer than 100 due to advances in treatment options. Other communicable diseases have also generated concern. Legionellosis was identified in the Netherlands in March 1999. The following year, the Netherlands was one of several countries that experienced an outbreak of meningococcal disease, and yellow fever and lassa fever were imported into the country. In 2003, Avian influenza also surfaced among the Dutch. Violence is a serious threat in the Netherlands, and the government has acknowledged that honor crimes are still occurring. New policies have been instituted to deal with this problem and with curtailing incidences of domestic violence. Unhealthy lifestyles are viewed as the major threat to good health. Consequently, the leading causes of death are cardiovascular disease (34 percent), cancer (29 percent), and intentional and unintentional injuries (4 percent). The Netherlands experiences higher rates of both lung and breast cancer than is common among European nations.
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SEE ALSO: Healthcare, Europe; Insurance. Bibliography. Central Intelligence Agency, “Nether-
lands,” World Factbook https://www.cia.gov/cia/publications/factbook/geos/nl.html (cited July 2007); Commission on the Status of Women, “Netherlands,” http://www. un.org/womenwatch/daw/Review/responses/NETHERLANDS-English.pdf (cited July 2007); Spencer Di Scala, Twentieth Century Europe: Politics, Society, Culture (McGraw-Hill, 2004); Robert E. Goodin, et al., The Real Worlds of Welfare Capitalism (Cambridge University Press, 1999); Sandra Halperin, War and Social Change in Modern Europe: The Great Transformation Revisited (Cambridge University Press, 2004); Martin A. Levin and Martin Shapiro, eds., Transatlantic Policymaking in an Age of Austerity: Diversity and Drift (Georgetown University Press, 2004); Jeremy Rifkin, The European Dream: How Europe’s Vision of the Future Is Quietly Eclipsing the American Dream (Jeremy P. Tarcher/Penguin, 2004); Social Watch, “Netherlands,” http://www.socialwatch. org/en/fichasPais/155.html (cited July 2007); Peter Taylor-Gooby, New Risks, New Welfare: The Transformation of the European Welfare State (Oxford University Press, 2004); United Nations Children’s Fund, “Netherlands,” http://www.unicef.org/infobycountry/netherlands_statistics.html (cited July 2007); World Bank, “Netherlands Data Profile,” http://devdata.worldbank.org/external/CPProfile.asp?PTYPE=CP&CCODE=NLD (cited July 2007); World Health Organization, “Highlights on Health in the Netherlands,” http://www.euro.who.int/document/CHH/ NET_highlights.pdf (cited July 2007); World Health Organization, “Netherlands,” www.who.int/countries/nld/ en/ (cited July 2007). Elizabeth R. Purdy, Ph.D. Independent Scholar
Neural Tube Defects Neural tube defects (NTDs) are a collection of congenital disorders related to the failure of neurulation or the process by which the neural tube is formed, closed, and subsequently encapsulated. Although they can occur as single anomalies, neural tube defects are usually one component of multifaceted genetic disorders. Environmental factors, such as a deficiency in
1222 Neuroblastoma folic acid or the presence of teratogen valproic acid, are also associated with NTDs. The neural tube is an ectoderm-derived tissue that develops into the central nervous system (CNS) including the brain and spinal cord. Specified by the notochord (the predecessor of the vertebral body), neural tube formation begins at the fourth week of development through a process called neurulation. Neurulation involves the evagination of two neural folds in the neural plate, which grow to fuse at the midline. Fusion or closure of the neural tube proceeds in a rostral to caudal direction, producing a hollow tube with a central lumen called the neural canal. While the neural tube gives rise to the brain and spinal cord, the neural canal forms the ventricular network through which cerebral spinal fluid (CSF) flows. Neurulation is followed by the encapsulation of the CNS within the skull and spinal column. Proper neurulation is necessary for proper function of the CNS as well as proper protection. NTDs are classified according to which combination of tissues are involved, whether it be the neural tube, meninges (three layers of connective tissue which encapsulate the CNS), and overlying bone or soft tissue. Although there is a whole array of types of NTDs, the cause of NTD is unknown and likely to be a combination of genetics and environmental factors. Anencephaly is a malformation disorder resulting in the absence of the brain and calavarium. Anencephaly is a result of interrupted forebrain development. Microcephaly, or small head, results from inefficient cortical expansion. Holoprosencephaly is defined by the failure of the forebrain to be divided into two separate hemispheres, giving rise to a single continuous cerebral cortex. This is a consequence of defective dorsal midline induction by the roofplate for which bone morphogenetic proteins (BMPs), a group of signaling molecules, are known to be responsible. Schizencephaly is a fullthickness defect or cleft in the cerebral wall. Mutations in the Emx2 gene, a transcription factor responsible for cortical patterning with other proteins, has been found responsible. Defects in the calavarium allow for parts of the brain to herniate through the skull, resulting in a condition termed encephalocele. This most often occurs in the occipital region of the skull. Spina bifida
describes a group of disorders related to incomplete fusion of the vertebral arches. The vertebral arches are part of the spinal column and serve to protect the spinal cord from pinching while providing flexibility for movement. Spina bifida occulta, the most common spinal bifida, occurs in vertebral segments L1 to S1. Spina bifida may often be asymptomatic, presenting as a small tuft of hair on the overlying skin. Spina bifida cystica are severe forms of this malformation, involving protrusions of the spinal cord through the vertebral arches and skin. A meningocele is spina bifida cystica involving only the meninges. Alternatively, meningomyelocele is spina bifida cystica involving the meninges as well as part of the neural tube. Spina bifida cystica is suspected if elevated levels of alpha-fetoprotein are found in amniotic fluid. SEE ALSO: Folic Acid; Spina Bifida; Spinal Cord Diseases. Bibliography. V. Kumar, A. K. Abbas, and N. Fausto,
Robbins and Cotran Pathologic Basis of Disease, 7th ed. (Elsevier Saunders, 2005); E. S. Monuki and C. A. Walsh, “Mechanisms of Cerebral Cortical Patterning in Mice and Humans,” Nature Neuroscience (v.4/Suppl., 2001); K. L. Moore, Before We Are Born: Essentials of Embryology and Birth Defects (Saunders, 2003). Kimberly Gokoffski University of California, Irvine
Neuroblastoma Neuroblastomas are neuroblastic tumors that arise from primitive sympathetic ganglion cells of the sympathetic nervous system. Epidemiology Neuroblastoma affects children and is the third most common cancer afflicting this population, after leukemia and brain tumors. In infants less than 1 year of age, it is the most common cancer. More than 600 cases are diagnosed in the United States each year. The average age at diagnosis is 17 months old, and there is a higher predilection among Caucasian children than in those of African descent.
Established risk factors for the development of neuroblastoma include insufficient maternal consumption of folate and maternal use of opiates. There is also an association between neuroblastoma and Turner syndrome, Hirschsprung’s disease, and neurofibromatosis type 1 (NF1). Although most cases are sporadic, in 1 to 2 percent of patients, there is a family history of autosomal dominant inheritance. Clinical Presentation Because neuroblastomas arise anywhere in the sympathetic nervous system, they have a variety of ways of presenting to clinical attention. The most common primary sites are the adrenal gland, abdomen, and thorax; these three sites account for 80 percent of tumor locations. Neuroblastomas can also metastasize to various locations in the body via the circulatory and lymphatic systems. As such, presenting symptoms reflect the location of the neuroblastoma. Tumors that arise in the abdomen typically cause sensations of pain or fullness, constipation, decreased bladder capacity, and even swelling of the legs due to obstructed venous or lymphatic drainage. Thoracic tumors can cause tracheal deviation with resultant breathing difficulties, and neuroblastomas that form along the spine can cause pain, neurologic deficits, and loss of bowel and/or bladder control. Neuroblastomas are made up of neuroectodermal cells, which originate from the fetal neural crest and are targeted for the sympathetic nervous system (including the adrenal medulla). They develop from nodules of these residual neuroectodermal cells that are thought to incompletely respond to normal signals that stimulate morphologic differentiation. As with most health problems, there is a genetic basis to the development of neuroblastoma. In half of cases, chromosomal deletions are present from chromosomes 1p, 11q, and/or 14q. There can also be gains of chromosomes, such as with 17q. Deletions of 1p are associated with an increased amplification and expression of the oncogene MYCN, which is a DNA-binding transcription factor that can cause malignant transformation. Diagnosis As with all medical disorders, a history, physical examination, and laboratory evaluation are helpful in the diagnosis of neuroblastoma. A definitive
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diagnosis, however, requires histology from either tumor primary tissue or bone marrow metastases. Imaging studies can be useful in diagnosing neuroblastoma. Ultrasound is often the initial study used to evaluate an abdominal mass, and can also be used in the prenatal diagnosis of neuroblastoma. Computed tomography (CT) and magnetic resonance imaging (MRI) can give a clearer picture. Other imaging modalities include radionuclide bone scans to evaluate metastatic spread to bone, and scintigraphy which can detect specific chemicals (such as metaiodobenzylguanidine, or MIBG) that are concentrated in neuroblastoma and other nervous tissue. Staging Neuroblastomas are staged according to the International Neuroblastoma Staging System (INSS). According to this system, there are six different tumor stages: 1, 2A, 2B, 3, 4, and 4S. Stage 1 is localized tumor with complete gross excision. Stage 2A is localized tumor with incomplete gross excision. Stage 2B is localized tumor plus tumor present in ipsilateral nonadherent lymph nodes. Stage 3 is unresectable unilateral tumor. Stage 4 is tumor disseminated to lymph nodes, bone, bone marrow, and/or skin. Stage 4S is tumor dissemination in infants less than 1 year of age only to skin, liver, and/or bone marrow; a high rate of spontaneous regression is seen with tumors of this type. Treatment The particular treatment of neuroblastoma depends on the risk of the disease. For low-risk disease, surgery alone is the primary treatment. For tumors that cannot be completely resected, chemotherapy and radiotherapy can be added. For intermediate-risk neuroblastoma, the optimal treatment is surgery plus chemotherapy; radiation can be added if the tumor is unresectable. Treatment is most aggressive for high-risk disease and includes chemotherapy, surgery, high-dose chemotherapy with hematopoietic stem-cell rescue, and radiation therapy. New treatment modalities that are being employed include immunotherapy, vaccinations, and bone marrow transplants. For patients with neuroblastoma, prognostic factors include tumor stage, age at diagnosis, pathology,
1224 Neuroendocrinology and genetic factors. Tumor stage is the most important factor. In terms of age, the younger the patient, the better the prognosis. Five-year survival rates for overall disease are 83 percent for patients younger than 1 year; 55 percent when age 1 to 4; and 40 percent when age 5 to 9. These days, patients with lowrisk disease have long-term survival of almost 100 percent, intermediate-risk disease of 90 percent, and high-risk disease of 30 percent. SEE ALSO: Brain Cancer; Cancer (General); Leukemia; Pe-
diatrics; Turner’s Syndrome.
Bibliography. Max J. Coppes, David G. Tubergen, and
Robert J. Arceci, Pediatric Oncology in the 21st Century (Saunders, 2001); Audrey E. Evans, Advances in Neuroblastoma Research (Raven Press, 1980). Khoi D. Than, M.D. Johns Hopkins University
Neuroendocrinology Neuroendocrinology is the study of the interaction between the nervous system and the endocrine glands and their secretions. The study of neuroendocrinology spans across the globe as evidenced by neuroendocrine societies such as the International Neuroendocrine Federation and the American Neuroendocrine Society. Research is presented in journals such as Neuroendocrinology, Journal of Neuroendocrinology, and Hormones and Behavior. On June 14, 1917, the Association for the Study of Internal Secretions (currently the Endocrine Society) was founded to further investigate the field of endocrinology. Research in this field has led to a greater understanding of the human body, as evidenced by the 1977 Nobel Prize in Physiology and Medicine being awarded to Roger Guillemin and Andrew Schally for their work on the hypothalamus. This field of study primarily encompasses the hypothalamus and pituitary glands and the corresponding organs that they regulate. The hypothalamus is located just below the thalamus and is a derivative of the diencephalons. This part of the brain is involved with many functions including maintaining an individual’s
circadian rhythm and regulating homeostasis. It receives multiple inputs from various parts of the brain including the brainstem and the limbic forebrain. It also receives feedback inputs such as gonadal steroids and glucocorticoids. The hypothalamus is responsible for releasing the following hormones: corticotrophinreleasing hormone (CRH), gonadotropin-releasing hormone (GnRH), growth hormone releasing hormone (GHRH), somatostatin, thyrotropin-releasing hormone (TRH), hypocretin, antidiuretic hormone (ADH), and dopamine. In addition to releasing hormones, the hypothalamus sends projections to many areas of the brain via the medial forebrain bundle, the mammillotegmental tract, the dorsal longitudinal fasciculus, the mammillothalamic tract, the stria terminalis, and the fornix. The pituitary gland resides in the pituitary fossa and is functionally connected to the hypothalamus via the median eminence. It is also responsible for maintaining homeostasis and regulating other endocrine glands via hormone secretions. Anatomically and functionally, it is divided into two lobes. The anterior lobe or adenohypophysis is derived from ectoderm and is responsible for regulating other endocrine glands via the release of hormones. It is regulated largely by the hypothalamus via the hypothalamic-hypophyseal portal system and by feedback mechanisms. The finding of this relationship was attributed to Geoffrey Harris in the early 20th century, who is now considered by most to be the father of neuroendocrinology. The anterior pituitary gland releases growth hormone, prolactin, follicle-stimulating hormone, luteinizing hormone, thyroid stimulating hormone, adrenocorticotropic hormone, and endorphins. The posterior pituitary lobe or neurohypophysis is connected to the hypothalamus via the infundibulum or tuberoinfundibular pathway. Oxytocin and antidiuretic hormone (vasopressin) are produced in the paraventricular nucleus and supraoptic nucleus of the hypothalamus, respectively. These hormones then travel down the infundibulum and are secreted from by the posterior pituitary gland. Dysfunction or disease of the hypothalamus or pituitary gland can lead to pathologies affecting their target organs. These pathologies may either be due to an overproduction or underproduction of hormones. For instance, individuals with excessive growth hormone may suffer from acromegaly, a condition associated
Neurofibromatosis
with macrocephaly and coarse facial features. Conversely, an underproduction of growth hormone leads to growth hormone deficiency and shorter stature as well as other signs and symptoms. There may also be overproduction or underproduction of posterior pituitary hormones. For example, an overproduction of vasopressin may lead to the syndrome of inappropriate antidiuretic hormone (SIADH), while underproduction of vasopressin will cause diabetes insipidus. The field of neuroendocrinology relies on many laboratory studies for evaluation of possible disease states. For example, levels of particular hormones can be assessed as well as other corresponding laboratory tests such as electrolytes and complete blood counts. In some instances, like growth hormone deficiency, karyotyping the individual or determining bone age may help to narrow or confirm a diagnosis. Imaging may also be helpful to determine if there are any structural problems with the organs themselves. Specifically, magnetic resonance imaging has been used to evaluate hypothalamic or pituitary abnormalities. Neuroendocrine pathology may be due to infectious disease processes, neoplasms, hyperplasia, and trauma. Treatment often revolves around treating the individual pathologies, ranging from medications to surgical techniques. Research is currently aimed at maintaining the hormonal balance in patients with disease. SEE ALSO: Endocrine Diseases (General); Endocrinology;
Neurologic Diseases (General); Neurologist.
Bibliography. E. Duncan and J. A. Wass, “Investigation
Protocol: Acromegaly and Its Investigation,” Clinical Endocrinology (v.50/3, 1999); S. F. Kemp, “Growth Hormone Therapeutic Practice: Dosing Issues,” The Endocrinologist (v.6, 1996). Darrin J. Lee University of California, Irvine
Neurofibromatosis Neurofibromatoses are disorders that affect the skin, nervous system, and bone in children and young adults. The three most common forms are neurofi-
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bromatosis type-1 (NF-1), neurofibromatosis type-2 (NF-2), and schwannomatosis. NF-1, also known as von Recklinghausen disease, commonly manifests with skin lesions known as “café-au-lait” spots, benign tumors known as neurofibromas that grow around peripheral nerves, scoliosis, and other soft tissue tumors. NF-2 usually presents with bilateral slow-growing tumors known as vestibular schwannomas, which may cause hearing loss or tinnitus (ringing in ears). The third variant, schwannomatosis, results in multiple painful schwannomas throughout the body. NF-1 and NF-2 are genetic disorders resulting from mutations in tumor suppressor genes, and they are inherited in an autosomal dominant fashion. The severity of symptoms varies widely among individuals. Tumors are treated by surgical excision, with chemotherapy, and radiation reserved for rare malignancies. Pathophysiology The development of tumors in neurofibromatosis is related to high levels of nerve growth stimulating activity. NF-1 occurs in 1 in 3,000 individuals worldwide, regardless of race and sex. The NF-1 gene is found on chromosome 17 and encodes the protein neurofibromin, which acts as a tumor suppressor. Mutations in this protein cause abnormal regulation of the cell cycle and tumor formation. Approximately 40 percent of NF-1 cases are caused by spontaneous mutations, and 60 percent are inherited. NF-1 symptoms are unpredictable even within families; they range from mild cutaneous manifestations to severe debilitating tumors affecting several tissues. Although NF-2 is less common, arising in one in 40,000 people, the pathogenesis is similar. The NF-2 gene on chromosome 22 also encodes a tumor suppressor protein Merlin, which, when mutated, results in vestibular schwannomas, meningiomas, and other tumors. NF2 symptoms are more predictable, as family members present similarly. Symptoms and Diagnosis Various manifestations are associated with NF-1; however, the diagnostic criteria are broad. Characteristic findings include café-au-lait macules, neurofibromas, and Lisch nodules. The skin macules arise in the first three years of life as irregular brown spots. In prepubertal individuals, six or more macules of diameter greater than 5 mm (15 mm in postpubertal
1226 Neurological Diseases (General) individuals) may suggest NF-1. Neurofibromas are benign heterogeneous tumors containing a mixture of nerve-supporting schwann cells and other structural cells. These tumors arise in late adolescence and can be found cutaneously or on deeper nerve plexuses. Lisch nodules are benign dome-shaped tumors found superficially in the iris of the eyes of younger patients. Skeletal abnormalities in NF-1 patients include scoliosis, bowing of the tibia in the lower leg, fractures, and facial bony overgrowth known as sphenoid dysplasia. These patients may also present with freckling in the groin or armpit areas during puberty. Neurological symptoms, such as deafness, blindness from optic gliomas, and pain, may result from impingement of nerves by tumors. Patients may also have endocrine abnormalities, such as growth hormone deficiency, causing short stature. Of children with NF-1, 25 to 40 percent have learning disabilities and visuospatial deficits, whereas 5 to 10 percent have mental retardation. NF-2 commonly presents around age 20 with tinnitus, poor balance, or hearing loss caused by bilateral vestibular schwannomas of the auditory nerve. Meningiomas in the brain and other tumors also affect NF-2 patients. Patients with schwannomatosis have excruciating pain caused by nerve impingement by multiple schwannomas throughout the body, everywhere except the auditory nerve. Proper diagnosis is best accomplished with magnetic resonance imaging (MRI) of the brain, orbits, and cervical spine for NF-1, as well as the internal auditory canals for NF-2. Slit-lamp examination of the eyes can reveal Lisch nodules, and chest computed tomography (CT) is used for detecting thoracic tumors. Prognosis The life expectancy for a patient with neurofibromatosis is slightly lower than that of an unaffected individual, mainly because neurofibromas occasionally become malignant (3 to 15 percent additional risk). Other complications, such as hydrocephalus and heart defects, are rare. The prognosis of neurofibromatosis varies, but most patients have mild symptoms and enjoy productive lives. The approach to treating neurofibromatosis is primarily surgical; however, multiple disciplines are
involved in caring for the patient. If neurofibromas enlarge or begin to cause pain, the surgeon should suspect malignant transformation and perform surgical excision. Oncologists should follow up with radiation and chemotherapy. Plastic surgeons can correct facial and skin deformities, just as orthopedic surgeons can treat tibial bowing and scoliosis. Patients should be monitored annually with visual, audiologic, and speech testing for learning disabilities. In addition, families should be offered genetic counseling, prenatal testing, and support group information to address patient psychological issues. SEE ALSO: National Institute of Neurological Disorders
and Stroke (NINDS); Neurologic Diseases (General); Scoliosis; Tinnitus. Bibliography. National Institute of Neurological Dis-
orders and Stroke, “Neurofibromatosis Information Page,” www.ninds.nih.gov (cited October 16, 2006); James Tonsgard, “Clinical Manifestations and Management of Neurofibromatosis Type 1,” Seminars in Pediatric Neurology (v.13, 2006). Anjan P. Kaushik University of Virginia Dino Samartzis, D.Sc., M.Sc., Dip. EBHC Harvard University and Erasmus University Francis H. Shen, M.D. University of Virginia
Neurological Diseases (General) Neurological diseases present in a variety of ways and can involve the central nervous system ([CNS] the brain and spinal cord), the peripheral nervous system ([PNS] cranial and peripheral nerves), and the autonomic nervous system ([ANS] part of both the CNS and PNS). Problems with the brain and nervous system can affect one’s movement, speech, memory, senses, swallowing, breathing, learning, and so forth. In addition, emotional and psychological effects can result. The most common neurological diseases include stroke, sleep disorders, Alzheimer’s disease, headache, multiple sclerosis, epilepsy, amyotrophic
lateral sclerosis (Lou Gehrig’s disease), pain, Parkinson’s disease, brain tumors, learning and attention problems, and brain and spinal cord trauma. A few of these will be addressed below. Each disorder has its own causes or triggers; some are inherited or are due to biochemical or physical changes in the brain. Trauma, unfortunately, remains one of the leading causes of neurological impairment. Many diseases are also currently considered idiopathic (cause is unknown). Nevertheless, scientists are continuously unraveling the mysteries of the human brain, and as our understanding increases, our prevention methods and management regimens will improve. Stroke A stroke is in many ways analogous to a heart attack of the brain. When the brain does not receive a sufficient amount of blood, neurons are deprived of the nutrients and oxygen they need to survive. Two major types of stroke exist: the ischemic stroke and the hemorrhagic stroke. In an ischemic stroke, blood is blocked from getting to the brain. This usually happens because of fatty deposits in arteries (atherosclerosis) or a blood clot (emboli). A hemorrhagic stroke occurs when a blood vessel in the brain bursts and bleeds. It is often caused by an aneurysm—a thin and/or weak area of an artery. A milder form of stroke, a transient ischemic attack (TIA), occurs when less blood than normal gets to the brain but there is never complete occlusion. The duration of a TIA is usually short and the symptoms can range from nonexistent to remarkably similar to a complete stroke. The signs of stroke are usually sudden in onset and include numbness or weakness of the face, arm, or leg (mainly on one side of the body); trouble seeing in one or both eyes; trouble walking, dizziness, or loss of balance; confusion or trouble talking or understanding speech; or a bad headache with no known cause. A stroke is usually diagnosed by a physician who conducts a complete neurological exam and, when available, employs multiple imagines modalities. Computed tomography (CT) and magnetic resonance imaging (MRI) scans are the most common techniques used for suspected stroke victims. A CT scan is helpful in distinguishing between an ischemic and hemorrhagic stroke. A Doppler ultrasound can detect blood flow problems and is the least invasive imaging modality.
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The effects of a stroke vary depending on what part of the brain is involved. A stroke in the right hemisphere can cause problems judging distances, behavior changes, and short-term memory loss. A stroke in the left hemisphere can cause speech and language problems, and memory impairment. A stroke in the cerebellum will affect balance and coordination. Strokes in the brain stem can be particularly devastating, causing paralysis, loss of various sensations (i.e., pain, temperature, vibration), and even death. Several risk factors have been identified for stroke. They include age, family history, African-American race, hypertension, atrial fibrillation, heart disease, atherosclerosis, high cholesterol, diabetes, smoking, stress, obesity, pregnancy, childbirth, birth control pills, and menopause. Prevention is focused on education, regular appointments with one’s physician, promotion of healthy habits, and cessation of unhealthy habits. Prophylactic aspirin use and blood pressure control is usually only advised when some predetermined propensity for a stroke has been established (i.e., preexisting heart condition). Thrombolytics, such as tissue plasminogen activator (TPA), are the current gold-standard treatment for stroke. These drugs are the most potent “clot-dissolving” agents available; however, their usage is controlled by strict guidelines and is not without risk. TPA, for example, must be given within three hours of the start of a stroke to work—hence, the importance for a person having a stroke to get to a hospital quickly. Thrombolytics are contraindicated in recent stroke victims, renal insufficiency, diabetic retinopathy, coagulopathies, and recent surgical patients. Other medicines that are used to treat and prevent stroke include anticoagulants and antiplatelet agents, all of which vary in their risk-to-benefit ratios. Surgery is another treatment modality in the prevention and treatment of stroke. Carotid endarterectomy (CEA) is a type of surgery designed to remove the fatty deposits clogging the carotid arteries (that provide blood to the brain). If the stroke is of the hemorrhagic type, a neurosurgeon will usually place a metal clip at the site of an aneurysm or bleeding vessel. Alzheimer’s Disease Alzheimer’s disease (AD) is named after Dr. Alois Alzheimer, a German physician, who first noticed changes in brain tissue of woman who died
1228 Neurological Diseases (General) of enigmatic mental illness. His observations led to the classic signs now referred to as amyloid plaques and neurofibrillary tangles. AD is the most common form of dementia (loosely defined as a progressive decline cognitive function beyond what is expected from normal aging) among the elderly. The parts of the brain that are most commonly affected control thought, memory, and language. AD affects approximately 1 percent of the world’s population, but the etiology of AD is unknown and there is no cure. Several risk factors have been identified, however. The disease is more common in individuals older than 60. Family history is thought to be important in a subtype of the disease called early-onset familial AD; this form usually occurs between the ages of 30–60. The more common type of AD is known as late-onset AD, occurring later in life with no obvious inheritance pattern. A gene responsible for making a protein called apolipoprotein E (ApoE) has also been identified as mutated in people with AD. The normal protein is responsible for carrying cholesterol in our blood. Research has begun to suggest that high blood pressure, high cholesterol, and low levels of the vitamin folate may also increase the risk of AD. Evidence for physical, mental, and social activities as protective factors against AD is also increasing. The only definitive way to diagnose AD is to actually visualize the plaques and tangles in the brain (i.e., a brain biopsy). This is rarely done in clinical practice unless the patient is deceased. As a result, the diagnosis of AD is often considered possible or presumptive. Specialized tests to measure memory, problem solving, and counting have been developed to aid in the diagnosis. Imaging modalities and other medical tests, such as blood, urine, or spinal fluid tests, are often only helpful to rule out other causes for a person’s symptoms. AD is often insidious in onset and has a naturally slow course. Memory problems are often the first sign. On average, AD patients live 8 to 10 years after their initial diagnosis. Although medical intervention cannot cure the disease, several drugs are being used to prevent the worsening of symptoms, such as donepezil (Aricept®), rivastigmine (Exelon®), galantamine (Razadyne®), or memantine (Namenda®). Parkinson’s Disease Parkinson’s disease (PD) belongs to a group of conditions called neurodegenerative disorders. It is named
after James Parkinson, an English physician who first described a typical “shaking” in 1817. Cardinal features of PD include resting tremor, rigidity, bradykinesia (slow movement), and postural instability. Pathological findings reveal a loss of dopamine-producing neurons and Lewy bodies in an area of the brain called the substantia nigra. Researchers estimate that 60 to 80 percent of dopaminergic neurons need to be lost before any of the motor signs of PD begin to appear. Lewy bodies are concentric, eosinophilic, cytoplasmic inclusion bodies found in the neurons of several neurological pathologies.PD progresses gradually but can severely interfere with patients’ activities of daily living (ADL). Other symptoms may include depression and emotional changes; difficulty in swallowing, chewing, and speaking; urinary problems or constipation; skin problems; and sleep disruptions. The disease manifestations and progression differ slightly in each patient; some have only minor motor impairments while others become severely disabled. There are currently no medical tests available for detecting PD. A diagnosis is made from a patient’s medical history and the results of a neurological exam.At present, there is no cure for PD. However, medications have been developed that provide dramatic relief from the symptoms of the disease. Levodopa combined with carbidopa is usually the first-line therapy given to patients. Levodopa replenishes the brain’s supply of dopamine and carbidopa delays the conversion Levodopa into dopamine until it reaches the brain. If levodopa is converted into dopamine in the body, it will be unable to enter the brain and pass through the blood brain barrier. This combination helps almost 75 percent of patients with PD, but some symptoms respond better than others. Bradykinesia and rigidity respond best, while tremor and balance problems may be only marginally reduced. Anticholinergics are thought to help control tremor and rigidity. Other drugs, such as bromocriptine, pergolide, pramipexole, and ropinirole, all mimic endogenous dopamine in the brain. An antiviral drug, amantadine, also appears to reduce symptoms. Unlike with AD, surgical therapy is available for PD. Deep brain stimulation (DBS) is approved by the U.S. Food and Drug Administration. In DBS, electrodes are implanted into the brain and connected to a small electrical device called a pulse generator that can be externally programmed. DBS can reduce the need for levodopa and related
drugs, which in turn decreases the involuntary movements called dyskinesias that are a common side effect of levodopa. Epilepsy Epilepsy occurs because of abnormal electrical activity in the brain. There are many types of epilepsy, often broadly classified as being either generalized or partial. In some instances, a seizure is preceded by feelings of dizziness, nausea, flashing lights, or other strange unspecified sensations. This is called an aura. An aura can be used to a person’s advantage, warning them of an impending epileptic attack. A generalized seizure is a broad category of seizure types that represent the most common form of epilepsy. They occur when both sides of the brain are involved—usually starting on one side and spreading to the other. These seizures produce muscle twitches, convulsions, and loss of consciousness. People suffering from generalized seizure disorder do not remember having an epileptic attack. Included under the rubric of generalized seizures are tonic-clonic (grand mal), absence (petit mal), myoclonic, atonic, and status epilepticus. In tonic-clonic seizures, the body becomes rigid and jerks repetitively. An absence seizure is nonconvulsive and short lived. It usually lasts only 5 to 30 seconds and is often confused with daydreaming. Myoclonic seizures involve the area of the brain responsible for movement, the motor cortex. Twitching or jerks are often observed in specific parts of the body. Atonic seizures are characterized by a loss of muscle tone, with the patient usually suddenly falling to the ground. Status epilepticus is the most feared complication of epilepsy. It manifests as frequent, long-lasting seizure attacks without regaining consciousness. It is a medical emergency. Partial seizures are seizures affecting only one side of the brain. They do not cause a loss of consciousness. Two subtypes exist: simple partial and complex partial. A simple partial seizure is localized and focal in nature and is often called a “Jacksonian” seizure. They are short in duration and are often associated with strange sounds, smells, or vision. Complex partial seizures are similar in onset but progress to a change (not loss) in consciousness and feelings of déjà-vu. In most (50 to 70 percent) cases of epilepsy, the cause is unknown. In some instances, however, head
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injuries, such as a car accident or a fall; brain tumor; stroke; arteriosclerosis (fatty plaque buildup in arteries); and infection, such as meningitis or encephalitis, can predispose someone to epilepsy. In these cases, imaging modalities, such as MRI or CT scans can be helpful in identifying inflammation or damaged brain tissue. Otherwise, an electroencephalogram (EEG) is regularly used to assist in the diagnosis of epilepsy. The EEG of people with epilepsy will display large characteristic spikes; however, the test has a very low sensitivity and specificity. This is because approximately 5 percent of people without epilepsy have abnormal EEGs and around 20 percent of people with epilepsy have completely normal EEG activity. The mainstay of epilepsy treatment is pharmacotherapy. Numerous antiepileptic drugs are now available and are designed to control the symptoms and seizures associated with epilepsy. Some of the most common drugs include carbamazepine, phenytoin, valproic acid, gabapentin, and lamotrigine. They all work by reducing the abnormal firing and electrical discharge of cortical neurons. It is important to remember that different drugs work with different seizures and that they are all associated with their own group of side effects. Surgery can be used to treat epilepsy but is reserved for severe cases and only after medical therapy fails. In addition, the area of the brain where the seizure occurs must be known and accessible to the neurosurgeon. SEE ALSO: Alzheimer’s Disease; Brain Diseases; Epilepsy;
Neurological Diseases (General); Neurology; Parkinson’s Disease; Stroke. Bibliography. American Academy of Neurology, www.
aan.com (cited April 27, 2007); B. Bates, “Nervous System,” A Guide to Physical Examination and History Taking, 8th ed. (Lippincott, Williams & Wilkins, 2004); B. Bates, L. S. Bickley, and R. A. Hoekelman, “Chapter 18: Mental Status,” A Guide to Physical Examination and History Taking, 6th ed. (Lippincott, Williams & Wilkins, 1995); M. B. Carpenter and J. Sutin, Human Neuroanatomy, 8th ed. (Lippincott, Williams & Wilkins, 1983); E. Corrado, M. Rizzo, and R. Tantillo, “Markers of Inflammation and Infection Influence the Outcome of Patients with Baseline Asymptomatic Carotid Lesions: A 5-Year Follow-Up Study,” Stroke (v.37/2, 2006); W. E. DeMyer, Technique of the
1230 Neurologist Neurological Examination, 5th ed. (McGraw-Hill Professional, 2003); R. C. Hamdy, “Alzheimer’s Disease: An Overview,” Southern Medical Journal (v.94/7, 2001); R. Hauser and T. Zesiewicz, Parkinson’s Disease: Questions and Answers (Merit Publishing International, 1997); I. L. Katzan et al., “Use of Tissue-Type Plasminogen Activator for Acute Ischemic Stroke: The Cleveland Area Experience,” Journal of the American Medical Association (v. 283/9, 2000); R. Katzman, “Alzheimer’s Disease,” New England Journal of Medicine (v.314/15, 1986); J. W. McAuley et al., “Newer Therapies in the Drug Treatment of Epilepsy,” The Annals of Pharmacotherapy (v.31/1, 2002); National Institute of Neurological Disorders and Stroke, “NINDS Parkinson’s Disease Information Page,” www.ninds.nih.gov/disorders/parkinsons_disease/parkinsons_disease.htm (cited April 27, 2007); NINDS rt-PA Stroke Study Group, “Tissue Plasminogen Activator for Acute Ischemic Stroke. The National Institute of Neurological Disorders and Stroke rt-PA Stroke Study Group,” New England Journal of Medicine (v.333/24, 1995); M. R. Sperling, H. Feldman, and J. Kinman, “Seizure Control and Mortality in Epilepsy,” Annals of Neurology (v.46/1, 1999); R. L. Watts, “The Role of Dopamine Agonists in Early Parkinson’s Disease,” Neurology (v.49, 1997); R. M. Zweifler, “Management of Acute Stroke,” Southern Medicine Journal (v.96/4, 2003). Jared Ament Independent Scholar
ate training. It is common for many neurologists to have studied psychiatry or have training in psychiatric disorders. There has also been an emerging field with neurologists who deal with patients who suffer from hereditary problems. The American Neurological Association, with its headquarters in Minneapolis, Minnesota, was founded in 1875, and in the United Kingdom, the Association of British Neurologists was founded in 1933. Famous neurologists include Guillaume-Benjamin-Amand Duchenne from France who was the first to describe many nervous and muscular disorders; Pierre Marie whose work led to a greater understanding not only of neurology but also of endocrinology; the French Jean-Martin Charcot who pioneered many techniques; Pierre Janet, another French neurologist, whose work received much publicity in the United States; the American Walter Bradford Cannon who combined neurology with physiology; Austrian Sigmund Freud who was the founder of psychoanalysis; and Sir Roger Bannister, the British athlete who was the first man to run the distance of one mile in less than four minutes. Mention should also be made of Axel M. F. Munthe, the author of The Story of San Michele (1929), who trained as a neurologist under Charcot. SEE ALSO: Neurological Diseases (General); Neurology. Bibliography. Floyd E. Bloom, et al., eds., The Dana
Neurologist A neurologist is a physician involved in neurology, the treatment of disorders of the nervous system. Neurologists’ task is to provide diagnosis, treatment, and management for patients who suffer from neurological disorders. The requirement in the United States for a neurologist is to have a medical degree and then complete four years of medical school, a one-year internship, and then three years of specialized training. In addition, many neurologists have also undertaken courses in specific neurological areas such as stroke, epilepsy, headaches, and movement disorders such as multiple sclerosis or neuromuscular disease. In other countries, neurologists tend to have a medical degree and between three to five years of postgradu-
Guide to Brain Health (Simon & Schuster, 2003); Jasper R. Daube, ed., Clinical Neurophysiology (Oxford University Press, 2002).
Justin Corfield Geelong Grammar School
Neurology Neurology is the branch of medicine responsible for studying, diagnosing, and treating patients with disorders of the nervous system. This involves the central nervous system (CNS—the brain and spinal cord), the peripheral nervous system (PNS—cranial and peripheral nerves), and the autonomic nervous system (ANS—part of both the CNS and PNS). The range
of disorders is exceedingly broad, from headaches to epilepsy, Alzheimer’s disease, Parkinson’s disease, strokes (cerebral vascular accidents), infections, neoplasms, immune-mediated diseases, and more. History Modern neurology had its beginnings in the 16th century with Vesalius. He described the anatomy of the brain but offered little insight into its function. Thomas Willis was the first to remove the brain from the skull intact and later went on to publish his Anatomy of the Brain in 1664. Willis was the first to describe the circle of Willis, the vascular structure at the base of the brain that ensures blood flow and perfusion bilaterally. He introduced the idea of localization and vaguely described epilepsy, apoplexy, and paralysis. Training A neurologist’s training varies from country to country, but generally, it involves obtaining a medical degree followed by three to five years of postgraduate specialty training. Opportunities exist to subspecialize even further in areas such as stroke and epilepsy. Sine qua non to neurology and irreplaceable to the neurologist’s skills is the neurological physical exam. Typically, it begins with assessing the cranial nerves I–XII. Strength of each limb is then measured on a scale from 0 to 5—5 representing full strength and 0 being paralysis. It is important to compare both sides of the body during an examination because a substantial amount of information about a neurological disorder and its specific location can be derived from its pattern of effects: unilateral, bilateral, or contralateral involvement. Sensations to pain, temperature, or vibration in addition to proprioception (the unconscious perception of movement and spatial orientation) are examined next. This is followed by eliciting deep tendon reflexes to distinguish between upper and lower motor neuron diseases (CNS versus PNS, respectively). The neurological exam normally concludes by testing coordination and gait in order to assess cerebellar function. Imaging Imaging has become commonplace in neurology, particularly in the developed world. Computerized tomography (CT) scans, magnetic resonance imaging
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(MRI), and magnetic resonance angiography/venography (MRA/MRV) have revolutionized the way neurologists diagnose and manage patients. Etiologies that once remained allusive or inconclusive can now be more readily confirmed or rebuked than in the past. In addition, pathologies are being localized and followed in a relatively noninvasive way, increasing patient compliance and overall management efficacy. Imaging is also being used in academia as a tool to train medical students, residents, and subspecialists. Management Discussing each therapeutic strategy separately is difficult because of the diversity of etiologies. In many instances, the initial insult is irreversible, and so, the primary goal is to limit secondary injury. In the case of suspected head or neck trauma, immobilization and spinal stabilization has become the mainstay of initial management, often occurring concomitantly with hemodynamic stabilization. Generally, neurological diseases are managed in a multidisciplinary fashion. This can involve medications, radiation therapy, and possibly referral to a neurosurgeon. Medical therapy varies with etiology, but it most commonly includes antiepileptics, fibrinolytic therapy for stroke patients, behavioral modifiers, steroids, analgesics, and neuromuscular agents. Fibrinolytic therapy, such as tissue plasminogen activator (t-PA), has had significant media coverage in recent years. This has been in part due to their exorbitant cost and to the potentially fatal consequences associated with their usage in some patients. Their ability to “dissolve” clots and prevent progressive damage in stroke patients cannot be disputed, however. As a result, the American Stroke Association has published strict guidelines outlining absolute and relative contraindications regarding the usage of fibrinolytics. A dreaded complication of several neurological disorders is increased intracerebral pressure (ICP). An increased ICP can cause herniation of the brain into the brainstem, usually resulting in death. Imaging is an enormous asset in ruling out space-occupying lesions that are often the cause of the increased ICP. This is especially important prior to performing a lumbar puncture (LP). LPs are common practice in neurology and are used to analyze cerebrospinal fluid, most often in cases of suspected meningitis. However, performing an LP with an increased ICP can pro-
1232 Neuromuscular Disorders mote herniation, and so, where available, it is often preceded by some imaging modality. Patient position, hyperventilation, hyperosmolar therapy, and rarely, barbiturates are used in the management of an increased ICP, irrespective of the initial cause. SEE ALSO: Neurologist; Neuroradiologist; Neuroradiol-
ogy; Neuroscience; Neuroscientist.
Bibliography. B. Bates, “Nervous System,” A Guide to
Physical Examination and History Taking, 8th ed. (Lippincott, Williams & Wilkins, 2004); B. Bates, L. S. Bickley, and R. A. Hoekelman, “Mental Status,” A Guide to Physical Examination and History Taking, 6th ed. (Lippincott, Williams & Wilkins, 1995); M. B. Carpenter and J. Sutin, Human Neuroanatomy, 8th ed. (Lippincott, Williams & Wilkins, 1983); E. Corrado, M. Rizzo, and R. Tantillo, “Markers of Inflammation and Infection Influence the Outcome of Patients with Baseline Asymptomatic Carotid Lesions: A 5-Year Follow-Up Study,” Stroke (v.37/2, 2006); W. E. DeMyer, Technique of the Neurological Examination, 5th ed. (McGraw-Hill Professional, 2003); F. Dirnberger and K. Becker, “Surgical Treatment of Migraine Headaches by Corrugator Muscle Resection,” Plastic and Reconstructive Surgery (v.114/3, 2004); C. M. Fisher, “Late-Life Migraine Accompaniments—Further Experience,” Stroke (v.1119/5, 1986); P. A. Forsyth and J. B. Posner, “Headaches in Patients with Brain Tumors: A Study of 111 Patients,” Neurology (v.43/9, 1993); J. W. McAuley, et al., “Newer Therapies in the Drug Treatment of Epilepsy,” Annals of Pharmacotherapy (v.36/1, 2002); R.M. Zweifler, “Management of Acute Stroke,” Southern Medical Journal (v.9/4, 2003). Jared Ament Independent Scholar
Neuromuscular Disorders Disorders that affect the central and peripheral nervous system which ultimately lead to muscle dysfunction are termed neuromuscular diseases. There are more than 40 different types of neuromuscular diseases that have been identified. They can affect any part of the body by wasting away muscles. Muscular dystrophies, myasthenia gravis, neuropathies,
amyotrophic lateral sclerosis (ALS), and spina bifida are few examples of neuromuscular conditions. All ages are equally susceptible to contrive a neuromuscular disorder. These diseases are difficult to diagnose. Moreover, they limit the patient’s physical movement. As a result, the patient usually becomes dependent on mobility equipment, medical assistance such as home health, or on support of relatives. Yet, some patients may become socially reserved which indirectly affects their psychological health as well. Myasthenia Gravis Myasthenia gravis is a rare autoimmune disorder that causes muscle weakness due to a problem at the neuromuscular junction. It is a chronic illness in which the body’s immune system produces antibodies against the chemicals (neurotransmitters such as acetylcholine) which initiate nerve impulses. Normally, they would trigger muscle contraction; however, in myasthenia gravis patients, it leads to skeletal muscle weakness and fatigue, which is worsened with physical exertion. Although myasthenia gravis can affect any muscle, the most affected group of muscles remains those innervated by cranial nerves (nerves that emerge from brain and innervate parts of face, lips, tongue, neck, and throat). Other symptoms include weakness and difficulty in controlling muscles of eyes, mouth, arms, hands, legs, and fingers. These early symptoms of muscle weakness may get better with proper rest; nevertheless, if they continue to occur, it may give rise to serious paralysis due to loss of muscle function. Weakness in respiratory muscles can lead to life-threatening breathing problems. Stress, changes in temperature, and infections can add on to pain in some cases. Currently, there is no cure for myasthenia gravis, but providing care with appropriate treatment can help alleviate the painful symptoms. Doctors usually treat myasthenia gravis by prescribing anticholinestrase drugs, corticosteroids, or immune-suppressing drugs that reduce inflammation and inhibit the immune response. Alternatively, a physician may offer surgery to remove the thymus gland, as the thymus gland is part of an immune system that is thought to be linked with the sickness caused by myasthenia gravis. Women younger than 40 years are most susceptible to develop this disorder, but in general, myasthenia gravis can occur
at any age, particularly when derived from a tumor. About 20 percent of mothers suffering from myasthenia gravis are at risk of transmitting the disease to their newborns. Amyotrophic Lateral Sclerosis. Amyotrophic lateral sclerosis (ALS), also known as Lou Gehrig’s disease, is a motor neuron (nerve cells innervating muscle cells) disease that leads to muscle atrophy. This muscle wasting may also lead to paralysis. ALS usually does not show its symptoms in a young age and is more often seen after age 40. Main symptoms include increasing weakness, twitching, and cramping of muscles. Difficulty in breathing, speaking, swallowing, and walking may also be experienced. However, a patient usually will suffer from these symptoms during the last stage of ALS. Because ALS is a chronic illness, it can either be fatal in a year’s time or can prolong for years. However, all motor functions of the body ultimately deteriorate without impairing the patient’s intellectual ability. ALS is idiopathic in nature and affects about one in 100,000 people. The only risk factor suggested to lead to ALS is a genetic linkage with autosomal dominant trait. It is seen to be affecting both male and female patients equally. Spina Bifida (Myelodysplasia). Spina bifida is a condition in which an injury to the brain or spinal cord occurs. It arises either due to improper closure or rupture of neural tube during development. This illness may leave an individual with an open spine, muscle imbalance, spasticity, and hip and knee fractures. Spinal nerves may be damaged, leading to paralysis of the lower part of the body. Myelomeningocele (most severe), meningocele (mild form), and occluta (least severe) are the three most common forms of spina bifida. Surgery could be an option for relieving these symptoms. SEE ALSO: Muscular Dystrophy; Myasthenia Gravis. Bibliography. American Medical Association, American
Medical Association Family Medical Guide, 4th ed. (John Wiley, 2004); Continuum Health Partners, “Continuum Neurosciences: Neuromuscular Disorders,” http://www. wehealny.org/services/CHP_neuromusculardisorders/index.html (cited January 2007); European Neuromuscular Center, “Neuromuscular Disorders,” www.enmc.org (cited January 14, 2007); Maxine A. Papadakis and Stephen J.
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McPhee, 2007 Current Consult Medicine (McGraw Hill, 2007); The University of Chicago Hospitals: Department of Neurology, “Neuromuscular Disorders,” www.uneurology.uchicago.edu (cited January 2007); The University of Iowa Health Care, “Care for Neuromuscular Disorders,” http://www.uihealthcare.com/news/currents/vol2issue3/ 2neuropathies.html (cited January 2007); Worldortho, “Neuromuscular Disorders,” 7www.worldortho.com/database/etext/neuromuscular.html (cited January 2007). Jinal Mehta University of Missouri
Neuropsychologist Many disorders of behavior and cognition have come to be recognized as manifestations of physiological aberrations in the brain. This recognition has led to the psychological specialty of neuropsychology. A neuropsychologist is someone who uses the methods of psychology to evaluate, and sometimes treat, brain and spinal cord disorders. Neuropsychologists are psychologists who have had additional specialized training and have professional board recognition. Neuropsychologists evaluate cases where a physiological brain-based process is suspected to be the root of a cognitive or behavioral impairment. For example, knowing that different parts of the brain can serve specific functions, an otherwise normal person who suddenly cannot speak might be evaluated for a stroke (interruption of the blood supply) to one of the language centers of the brain. It is important to know that the cause of not speaking is a stroke versus another diagnosis, such as depression, because the treatments and prognoses are very different. Another example would be an elderly person whose family notices he or she is having memory problems and seems to be behaving strangely; the neuropsychologist would determine if changes in behavior and memory are due to normal aging or if the person has Alzheimer’s disease. Other common cases besides stroke and Alzheimer’s disease that a neuropsychologist might evaluate include traumatic brain injury, other dementing diseases, seizure disorders, toxic chemical exposure, substance abuse, developmental learning disabilities, attention deficit disorder, and autism.
1234 Neuroradiologist Neuropsychological evaluation is based in performing standardized tests that usually involve talking with the patient and having the patient perform simple tasks. These tests are designed to evaluate specific cognitive processes and help give a prognosis or treatment plan for the condition. Other tools that are useful to the neuropsychologist include brain imaging to detect structural or functional abnormalities and electroencephalograms (EEG) to detect changes in the electrical patterns or brain waves. SEE ALSO: Alzheimer’s Disease; Attention Deficit Disor-
der; Brain Diseases; Brain Injuries; Brain Malformations; Genetic Brain Disorders; Learning Disorders; Psychology; Psychologist; Psychoneuroimmunology.
Bibliography. Oscar A. Parsons, et al., eds., Neuropsy-
chology for Clinical Practice: Etiology, Assessment, and Treatment of Common Neurologic Disorders (American Psychological Association, 1996). Mark F. Brady, M.D., M.P.H., M.M.S. Brown University
Neuroradiologist As defined by the United States’ National Cancer Institute, a neuroradiologist is “a doctor trained in radiology who specializes in creating and interpreting pictures of the nervous system. The pictures are produced using forms of radiation, such as x-rays, sound waves, or other types of energy.” To become a neuroradiologist, an individual must graduate from medical school, complete a residency in radiology, and then pursue a fellowship in neuroradiology. Once done with this 10-year–long training process, a neuroradiologist can practice in hospitals, academic institutions, or private practice. Arthur Schüller (1874–1957) of Austria is considered the first neuroradiologist and, hence, the father of neuroradiology. His contributions include the first studies of x-ray findings in intracranial disease and more than 300 publications. Neuroradiologists are important in global health because they often provide the definitive diagnosis on some of the world’s most common neurologic prob-
lems, from hydrocephalus to multiple sclerosis to brain and spinal cord tumors. To make these diagnoses, neuroradiologists use a wide repertoire of tools including X-ray, computed tomography (CT), magnetic resonance imaging (MRI), angiography (imaging of blood vessels), and myelography (imaging of the spinal cord). Neuroradiologists also can perform interventional procedures, such as coil embolization of brain aneurysms or thrombolysis (dissolving) of blood clots causing stroke. Although not as typical as internal or emergency medicine physicians, there are plenty of neuroradiologists actively involved in public and international health. For instance, some neuroradiologists conduct research on the effects of neuroimaging on common neurologic diagnoses while others travel to impoverished countries and perform the different interventional procedures mentioned above. Given the growing demand of neuroradiologists and radiologists in general, these individuals will continue to play an important role in global health. SEE ALSO: Aneurysms; Brain Cancer; Hydrocephalus;
Multiple Sclerosis; Neuroradiology.
Bibliography. National Cancer Institute, www.cancer.
gov (cited July 2007); Erwin Schindler, “Arthur Schüller: Pioneer of Neuroradiology,” American Journal of Neuroradiology (v.18, 1997). Khoi D. Than, M.D. Johns Hopkins University School of Medicine
Neuroradiology Neuroradiology is a medical subspecialty within radiology that is involved with imaging the brain, spinal cord, head, and neck for use in diagnosis and treatment of diseases. The origins of this field date back to the early 20th century. Three prominent figures are associated with the development of this field. The Viennese neuropsychiatrist Arthur Schüller has been commonly deemed the “father of neuroradiology” for his seminal work using X-rays to evaluate intracranial disease. Walter Dandy, an American neurosurgeon, put forth the ventriculography and
Neuroradiology
pneumoencephalography techniques, while Egas Moniz, a Portuguese neuropsychiatrist developed cerebral angiography. Moniz later won the Nobel Prize in Physiology and Medicine for his work on prefrontal lobotomies. The field of neuroradiology has since expanded tremendously. As in the general field of radiology, this subspecialty uses X-rays, magnetic fields, radio waves, and ultrasound techniques to evaluate neurological disease processes. Computed tomography (CT) has been used in neuroradiology to help diagnose particular pathologies. In fact, it is commonly used in the emergency room to quickly evaluate patients with traumatic brain injury. This technique utilizes multiple X-rays from different angles to render a two-dimensional image. The imaging technique can be performed with or without a contrast agent, usually iodine. Contrast agents enable one to view structures and organs more easily. With advances in CT technology, the images have become more accurate and more precise. In addition, analysis of blood flow in arterial and venous vessels has been made possible by the use of CT angiography. It can be used to identify stenotic vessels and aneurysms. Magnetic fields have also been utilized to visualize the head and neck. Magnetic resonance imaging (MRI) uses magnetic fields to create images and forms the images based upon the relaxation of excited hydrogen nuclei in water and lipids. MRI has the advantage of providing a better contrast resolution than CT scans, and it does not expose the patient to ionizing radiation. MRI images can be either T1 or T2. The differences between these two types of images are based upon the realignment of nuclear spins. T2 images are generally better for visualizing pathologic tissue. Even within MRI, there are specialized imaging techniques. Diffusion weighted imaging (DWI) measures the diffusion of water molecules throughout tissues. This is a valuable tool for evaluating patients with ischemic stroke. Another technique that relies on diffusion of water is diffusion tensor imaging (DTI). This imaging technique is valuable for imaging cortical tracts. Like in CT, MRI techniques have also been developed to perform angiography. Magnetic resonance angiography (MRA) images arteries, while magnetic resonance venography (MRV) uses a similar process
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to evaluate veins. Using this modality, the patient is either given a paramagnetic contrast agent such as gadolinium or the procedure is done using a flow-related enhancement technique. CT and MR techniques have also been developed to determine cerebral perfusion, known as CT or MR perfusion imaging. MRIs can also be used to evaluate neural activity. Functional MRI (fMRI) is valuable in determining which areas of the brain are active during particular activities. The field of neuroradiology encompasses both diagnostic and invasive procedures. Interventional neuroradiology is a field in which the neuroradiologist is able to perform minimally invasive procedures under the guidance of an imaging modality. A common procedure done by interventional neuroradiologists is angiography to evaluate the intracranial blood vessels. Embolization of vessels can also be done to prevent rupture of blood vessel lesions, such as aneurysms or arteriovenous malformations. Before becoming certified in neuroradiology, one must first be trained in radiology, neurology, or neurological surgery. There are many professional societies for neuroradiologists, including the American Society of Neuroradiology, the American Society of Interventional and Therapeutic Neuroradiology, the European Society of Neuroradiology, and the Australian New Zealand Society of Neuroradiology. In addition, groups such as the Neuroradiology Education and Research Foundation (NREF) have formed to further strengthen the field and help to provide support for future research. In addition, there are a number of journals that focus on research on current advancements in the field, such as the American Journal of Neuroradiology and Neuroradiology. SEE ALSO: Neurology; Neuroradiologist; Radiologist; Ra-
diology.
Bibliography. M.G. Alper “Three Pioneers in the Early
History of Neuroradiology: The Snyder Lecture,” Documenta Ophthalmologica (v.98/1, 1999); A. J. Barkovich, “Strategy and Economics: An Overview of the Neuroradiology Education and Research Foundation and Its Activities,” American Journal of Neuroradiology (v.27, 2006). Darrin J. Lee University of California, Irvine
1236 Neuroscience
Neuroscience Most basically speaking, neuroscience is the study of the brain and nervous systems. The central nervous system consists of the brain and spinal cord. The peripheral nervous system is made up of the neurons that connect the spinal cord to muscles, as well as the neurons that transmit sensory information such as touch from our body to our spinal cord, which will then process that information or send it to the brain for further processing. The peripheral nervous system can be further broken down into the somatic and the autonomic nervous systems. The somatic nervous system is that which we can voluntarily control, such as movement. The autonomic, or ‘automatic’ nervous system, contains the sympathetic and parasympathetic nervous systems, as well as an additional nervous system, the enteric nervous system. This latter nervous system chiefly governs all things digestive in the body. Neuroscience is concerned with all aspects of the nervous system, including its development, maintenance, pathology and degeneration, aging, learning, and memory. Therefore, neuroscientists are members of a large number of other fields such as neurobiology, neurochemistry, neuro-physics, neuronal modeling via computers or electrical engineering, psychology, neuro-immunology, neuro-oncology, and more. It is much more than simply studying the brain; neuroscience incorporates the brain’s interactions with the rest of the body, as well as with its environment. The study of the function and pathology of the five senses is part of neuroscience. Additionally, a growing field in the early twenty-first century is the study of the inter-relations between the brain, nutrition, and our state of health, including our immune system. Much study can be carried out using humans in research; however, many fascinating discoveries were and are made using model organisms, each one particularly suited to a facet of neuroscience. A great amount of neuroscience research is done using model organisms. Some model organisms in use include cell culture, planarians, mice, rats, cats, bats, frogs, nonhuman primates, and songbirds. Much of what neuroscientists take as fact now came from meticulous investigations on the squid giant axon. The axon is the part of the neuron that sends an electrical signal from the neuron’s cell body, down to its target cell.
In humans, axons are typically on the order of tens of micrometers in diameter; in contrast, the squid giant axon can measure greater than one millimeter in diameter. Thus, to study the electrical properties of a human axon, extremely small electrodes are needed; these electrodes need not be so small for the squid. The squid therefore was a crucial model organism for early neuroscientists who investigated the electrical properties of an axon. It hasn’t always been known that the brain is the center of our thoughts. Ancient Egyptians and Greeks believed the heart to be the seat of our intelligence; then Hippocrates mused that the brain was involved, as it was central to the eyes, ears, and tongue. Finally the Roman physician Galen noted that Gladiators who had suffered brain trauma subsequently suffered from impaired mental function, and scientists accepted the brain as the seat of human intelligence. The father of modern neuroscience is considered to be Santiago Ramón y Cajal (1852-1934) of Spain. Ramón y Cajal used a silver-stain technique pioneered by Camillo Golgi to visualize single neurons and their connections. This work was the foundation for the Neuron Doctrine, which hypothesized that the functional unit of the brain was the neuron. Today we take this doctrine as fact, but it was much disputed at the turn of the twentieth century. For their contributions to the emerging field of neurobiology, which would become neuroscience further in the twentieth century, Ramón y Cajal and Golgi shared the Nobel Prize for Physiology or Medicine in the year 1906. Many diseases of modern society involve the brain and are therefore studied by researchers in neuroscience. These diseases include Alzheimer’s disease, Parkinson’s disease, Huntington’s disease, fragile X mental retardation, autism, and more. Other diseases affect the nervous system in some component, even though they are not initially obvious as neurological. These diseases include Diabetes and Shingles or Herpes zoster. Still other disorders have neurological components; these diseases include anorexia nervosa, bulimia nervosa, anxiety disorders, depression, social disorders, speech pathologies, and more. In the United States, the main professional society for neuroscientists is the Society for Neuroscience (SfN). The SfN publishes a monthly scientific journal of high merit—the Journal of Neuroscience. Additionally, the Society hosts an annual meeting for
Neuroscientist
neuroscientists to convene and share novel discoveries, thoughts, troubleshooting advice, as well as learn about new technologies and products to aid in their research. The Society is so large and attendance at the annual convention so high that only a few cities in the United States can host the convention. Globally, neuroscientists belong to the SfN as well as to multiple international societies for specific fields within neuroscience. One large-scale event that the SfN manages annually is Brain Awareness Week (BAW). BAW is geared towards non-scientist members of the public who are interested in learning more about the brain. It is for all ages, and is celebrated in all areas where local chapters of the SfN can be found. SEE ALSO: Alzheimer’s Disease; American Society on Ag-
ing (ASA); Anxiety Disorders; Brain Cancer; Brain Diseases; Brain Injuries; Brain Malformations; Diabetic Nerve Problems; Head and Brain Injuries; Head and Brain Malformations; Hearing Problems in Children; Mental Health; Movement Disorders; Multiple Sclerosis; Myasthenia Gravis; National Institute of Mental Health (NIMH); National Institute of Neurological Disorders and Stroke (NINDS); National Institute on Aging (NIA); Neural Tube Defects; Neuroblastoma; Neuroendocrinology; Neurofibromatosis; Neurologic Diseases (General); Neurologist; Neurology; Neuromuscular Disorders; Neuropsychologist; Neuroradiologist; Neuroradiology; Neuroscientist; Obsessive-Compulsive Disorder; Parkinson’s Disease; Psychiatrist; Psychiatry; Psychoimmunology; Psychologist; Psychology; Psychoneuroimmunology; Psychooncology; Psychotherapy; Shingles (Herpes Zoster); Tremor. Bibliography. Jack Antel, Gary Birnbaum, Hans-Peter
Hartung, and Angela Vincent, Clinical Neuroimmunology (Oxford University Press, 2005); Peter Dayan and L. F. Abbott, Theoretical Neuroscience: Computational and Mathematical Modeling of Neural Systems (The MIT Press, 2005); Galen and Ian Johnston, Galen: On Diseases and Symptoms (Cambridge University Press, 2006); Eric R. Kandel, J. H. Schwartz, and Thomas M. Jessell, Principles of Neural Science (McGraw-Hill Publishing Company, 2000); Paolo Mazzarello, Henry A. Buchtel, and Aldo Baldiani, The Hidden Structure: A Scientific Biography of Camillo Golgi (Oxford University Press, 1999); Dale Pruves, Neuroscience, 4th Ed. (Sinauer Associates, Inc., 2007); Santiago Ramón y Cajal, Javier DeFelipe, Edward G. Jones, and R. M.
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May, Cajal’s Degeneration and Regeneration of the Nervous System (History of Neuroscience, No. 5) (Oxford University Press, 1991). Claudia Winograd University of Illinois
Neuroscientist A neuroscientist is an individual who studies the nervous system. The nervous system consists of the brain, spinal cord, and networks of neurons that are distributed throughout the body. Neuroscientists investigate a wide variety of subtopics concerning the nervous system, such as: Stem cells and neurogenesis, development and aging of the brain, channels, receptors and neurotransmitters, neural plasticity and regeneration, functional imaging, as well as genetics of neurologic and psychiatric diseases. Neuroscientists typically research questions about the nervous system and develop methods of exploration ranging from imaging of a live person to culturing cells on a Petri dish. From such studies, neuroscientists discover how the nervous system develops and functions normally, in order to learn possible mechanisms that may go awry in neurological disorders. Neuroscientists are often educated in a wide variety of subjects including biology, chemistry, physics, computer science, and psychology. With this extensive background, neuroscientists aim to investigate brain function at many different levels, and see how they integrate and affect human performance and behavior. At the genetic level, recent research has been focused on identifying susceptibility genes of neurological conditions with the hope of detecting risks earlier in order to positively affect prognosis. With the recent development of the International HapMap Project, genetic similarities and differences in human beings have been catalogued from many ethnic backgrounds. Using this information, neuroscientists are able to pinpoint genes that affect health, disease, and individual responses to medications and environmental factors. In addition, with the completion of the Human Genome Project in 2003, the sequences of the 3 million base pairs that comprise human DNA can be studied. With such
1238 New Zealand valuable resources available, neuroscientists have been able to take on more complex diseases. At the molecular level, neuroscientists focus on studying genes, proteins, and chemicals that may affect brain function. Using such tools as microarray analysis, antibodies, and genetic probes, neuroscientists can isolate the genes that produce proteins thought to be involved in human disease. Neuroscientists interested in anatomy, neuroanatomists, investigate the structure and organization of the nervous system. Using dyes and microscopes, they can detect specific neurotransmitters, synapses, and receptors within specific regions of the brain. Developmental neuroscientists, on the other hand, study how the brain grows and changes over time. Such researchers study neuronal connections and resilience and how they may be affected by the environment. Behavioral neuroscientists study the processes of behavior in both humans and animals. They use such tools as microelectrodes, which measure neuronal electricity, and brain scans, which illustrate regions of the brain active while performing particular tasks. Finally, clinical neuroscientists, such as psychiatrists and neurologists, apply basic research findings to develop ways to treat debilitating neurological disorders. SEE ALSO: Brain Diseases; Brain Injuries; Psychiatry. Bibliography. Human Genome Project Information,
http://www.ornl.gov/sci/techresources/Human_Genome/ project/about.shtml (cited July 2007); International HapMap Project, www.hapmap.org (cited July 2007); The Society for Neuroscience, “What is Neuroscience, “http://web. sfn.org/index.cfm?pagename=whatIsNeuroscience§io n=aboutNeuroscience (cited July 2007). Misty C. Richards Albany Medical College
New Zealand With a per capita income of $25,300, New Zealand ranks as the 37th richest nation in the world. Consequently, New Zealanders enjoy a high living standard with easy access to health care. The UNDP Human Development Reports rank New Zealand 20th of all
nations of the world in general quality of life issues. To honor a strong commitment to health care, the government spends 17 percent of the total budget on health. Just over eight percent of the Gross Domestic Product (GDP) is earmarked for healthcare, and the government designates $1,893 (international dollars) per capita on health expenditures. The government provides 78.3 percent of total healthcare expenditures. The private sector furnishes another 21.7 percent, and 72.10 percent of that amount is out-ofpocket expense. There are 2.37 physicians, 8.16 nurses, 0.56 midwives, 0.68 dentists, and 0.92 per 1,000 population in New Zealand. New Zealand has a long history of providing social support for her people. In 1898, the Parliament became the first legislature in the world to pass a pension program for all elderly people below a certain income level. In 1920, the General Health Act established guiding principles for health care, which is administered under the auspices of the Health Department. The Social Security Act was enacted in 1938. Today, New Zealand is known as the “social laboratory of the world” due to innovativeness in social programs. One such innovation is the implementation of the Child Hygiene Program in which all pre-school children are examined twice and primary school children three times to identify potential health problems. Costs for the program, including medical, dental, and hospital benefits, are covered by social security. In December 2000, the government announced a new health strategy with a commitment to providing a trustworthy health system, subsidizing those who cannot pay for health services, and addressing inequities in the health status of Maori and Pacific people with other segments of the population. New Zealanders are highly urbanized, and around 80 percent of the population of 4,076,140 lives in cities. Life expectancy is high at 78.81 years. Women generally live six years longer than males. Literacy is virtually universal, and only one percent of the population over the age of 15 cannot read and write. More than 100 percent of the relevant population attends primary and secondary schools. Unemployment is under control at 3.7 percent of the labor force, and New Zealand has no identifiable poverty level. Income inequity does exist, and New Zealand ranks 36.2 on the Gini Index of Inequality. All people have access to safe drinking water and improved sanitation.
Nicaragua
On the average, women give birth to 1.79 children. Three-fourths of the female population uses some method of birth control. All births are attended by skilled professionals, and 95 percent of women receive antenatal care. The adjusted maternal mortality rate is seven deaths per 100,000 live births. Infant mortality is relatively low in New Zealand at 5.76 deaths per 1,000 live births. Between 1990 and 2004, infant mortality dropped from eight to five deaths per 1,000 live births, and under-five mortality declined from 11 to six deaths per 1,000 live births. While six percent of infants are underweight at birth, most New Zealand infants and children are healthy. The government subsidizes all required vaccinations, and immunization rates are relatively high. Some 96 percent of infants are immunized against diphtheria, pertussis, and tetanus (DPT1), 90 percent against DPT3, Hepatitis B, Haemophilus influenzae type B, 85 percent against measles, and 82 percent against polio. While HIV/AIDS (0.1 percent) is present in New Zealand, it has been controlled to a large extent. Around 1,400 are living with the disease, and approximately 200 have died from the disease and its complications. The New Zealand Health Strategy and Primary Health Strategy are important elements in ensuring good health in New Zealand. Under these initiatives, major resources have been directed at reducing child mortality, expanding well-child services, improving maternal health, and combating HIV/AIDS, malaria, and other infectious diseases. Great concern has also been expressed over rising alcohol abuse among young people and the Maori population, which has begun to spread to the general population. SEE ALSO: Birth Rate; Healthcare, Asia and Oceania. Bibliography. Commission on the Status of Women,
“New Zealand” http://www.un.org/womenwatch/daw/ Review/responses/NEW-ZEALAND-English.pdf (cited July 2007); John Bell Condliffe, The Welfare State in New Zealand (Westport, Connecticut: Greenwood, 1975); Alexander Davidson, Two Models of Welfare: The Origins and Development of the Welfare State in Sweden and New Zealand, 1888-1998 (Uppsala, Sweden: Almqvist and Wiksell International, 1989); “New Zealand,” CIA World Factbook https://www.cia.gov/cia/publications/factbook/geos/
1239
nz.html (cited July 2007); UNICEF, “New Zealand” http:// www.unicef.org/infobycountry/newzealand_statistics. html (cited July 2007); World Bank, “New Zealand Data Profile” http://devdata.worldbank.org/external/CPProfile. asp?PTYPE=CP&CCODE=NZL (cited July 2007); World Health Organization, “New Zealand” http://www.who.int/ countries/nzl/en/ (cited July 2007). Elizabeth R. Purdy, Ph.D. Independent Scholar
Nicaragua Nicaragua is located in Central America, stretching 490 kilometers (300 miles) from the Caribbean to the Pacific Ocean. A chain of active volcanoes line the western borders, and rivers form most of the northern and southern borders. It is bounded by Costa Rica and Honduras. Since winning independence from the Spanish in 1821, Nicaragua has struggled to find its political and economic footing. It is the second poorest country in the Americas and has the most unequal distribution of wealth in the hemisphere. Almost 50 percent of the population lives below the poverty line. The population is estimated at 5,675,000 and growing at a rate of 1.86 percent annually. The birth rate is 24.12 per 1,000 population, the death rate is 4.42 per 1,000 population, and the migration rate is in deficit at minus 1.15 per 1,000 population. The median age is 21.3 years. Life expectancy at birth is 68.82 years for males and 73.13 years for females. About 58 percent of the population lives in urban areas. Gross national income is estimated at $910 a year, with 45 percent of the population subsisting on $1 a day or less. Poor sanitation and ample amounts of standing water create a hospitable climate for vector-borne and water-borne diseases. Malaria is common throughout the country, with little money or resources available to combat it. Dengue fever has been endemic since 1985. Cholera control programs have helped reduced the rate of infections dramatically since the 1990s. Acute respiratory infections impact 1 million people annually, leading to about 1,200 deaths. The prevalence rate for HIV/AIDS is 0.2 percent, with more than half of the estimated 7,300 cases diagnosed within the last three years. While this seems like
1240 Niger a low-level epidemic, there are fears that it could become much more widespread. While the government has developed a strategic plan, there is little money to fund a comprehensive program of education and prevention, and it in a country where 88 percent of the population is either Roman Catholic or Evangelical, there are strong taboos regarding sex education and condom distribution. Women and children are vulnerable populations with Nicaragua. UNICEF estimates that 1 in 3 children are chronically malnourished. Sexual activity begins early among Nicaraguan youths, with 25 percent of all pregnancies occurring in adolescents. Forty-three percent of marry before the age of 17. About 69 percent of women use birth control, and 86 percent receive some form of prenatal care. Only 67 percent of births are assisted by a trained attendant. The maternal mortality rate is 150 deaths per 100,000 live births. Domestic violence is common, and women are the sole head of 1 in 4 Nicaraguan households. An estimated 8.2 percent of the gross domestic product is devoted to health care. The government spends about $32 per capita on health services. There are around 2,000 doctors and 5,900 nurses at work in the country. Distribution of care is somewhat uneven outside the urban areas; 33 percent of the rural population is more than two hours walk from the nearest hospital. There is, however, a good system of health clinics to serve isolated communities. A private care system is emerging within the country, but most rely on public services. SEE ALSO: Birth Rate; Healthcare, South America. Bibliography. “Nicaragua,” CIA World Factbook, https://
www.cia.gov/library/publications/the-world-factbook/ geos/nu.html (Cited June 2007); “Nicaragua: Heath in the Americas, 1998,” Pan American Health Organization, http://www.paho.org/english/HIA1998/Nicaragua.pdf (cited June 2007); UNAIDS: The Joint United Nations Programme on HIV/AIDS, “Nicaragua,” http://www.unaids. org/en/Regions_Countries/Countries/nicaragua.asp (cited June 2007); UNICEF, “At a glance: Nicaragua—Statistics,” http://www.unicef.org/infobycountry/nicaragua_statistics. html (cited June 2007); UNICEF, “At a glance: Nicaragua— The big picture,” http://www.unicef.org/infobycountry/ nicaragua_2086.html (cited June 2007); World Health Organization, “Core Health Indicators/WHO 2007,” Core
Health Indicators/WHO 2007, http://www.who.int/ whosis/database/core/core_select.cfm (cited June 2007). Heather K. Michon Independent Scholar
Niger Niger is a landlocked country located in west Africa, surrounded by Nigeria, Chad, Libya, Algeria, Mali, Burkina Faso, and Benin. Once a crossroads of the African economy, Niger today sits at the absolute bottom of the United Nations Development Programme Human Poverty Index Scale. The total population is 12.53 million, growing at 2.92 percent annually. The birth rate is 50.73 per 1,000 and the death rate is 20.91 per 1,000. Only 23 percent of the population is urbanized, although the annual rate of urban growth is currently 5.8 percent. Poverty is almost total. The economy is based largely on uranium exports, but world demand for uranium is low. Most Nigerois are subsistence farmers, getting by on a per capita income of $260 a year. More than 60 percent of the population live on less than $1 a day. Niger is chiefly desert, and suffers from recurrent droughts, overgrazing, soil erosion, deforestation, desertification, and loss of biodiversity from wildlife poaching. Recent droughts have led to food shortages for 2.5 million Nigerois. In 2006, humanitarian groups noted a deepening food crisis within the country, with 62,000 cases of moderate malnutrition and over 7,000 cases of severe malnutrition identified before the middle of the year. Life expectancy at birth is 43.8 years for males and 43.73 years for females. Healthy life expectancy is 35.8 years for men and 35.2 years for women. Infant mortality is 154 deaths per 1,000 births. Mortality for children aged 1–5 is 259 deaths per 1,000. Maternal mortality is among the world’s highest, with 1,600 deaths per 100,000. The average Nigerois woman has 7.46 children in her lifetime, and the lifetime chance of dying in childbirth is one in seven. Only 16 percent have a trained attendant present at birth. A high incidence of obstetric fistula is a by-product of early and frequent childbirth. Obstetric fistula is a tear in the birth canal, which, left unrepaired, can
Nigeria
lead to urinary or fecal incontinence, often leading to abandonment or shunning by the community. More than 200,000 Nigerois women are believed to suffer from this injury, but there are only six doctors in the country qualified to perform corrective surgery. Young children in Niger have a high mortality rate, mostly from acute respiratory infection, malaria, diarrhea, and accidents such as burns (95 percent of the country relies on wood- or coal-burning stoves for cooking). However, an active immunization has brought at least one disease—measles—under control, dropping from 50,000 cases a year to just over 2,000 cases in 2005. If they survive childhood, few children have the opportunity for schooling; literacy rates are 20 percent among males and 9 percent among females. About 66 percent of Nigerois children between the ages of 5 to 14 work. In rural areas, 86 percent of girls marry before the age of 18. Low life expectancy leaves many children without parents early in life, and there are currently about 680,000 orphans under the age of 17. Sanitation is limited, with 46 percent having access to clean water and 12 percent with sanitary facilities. Prevalence of diarrhea, hepatitis A, typhoid, and meningitis is high. There are about 850,000 cases of malaria each year. Cholera is common in the south, particularly in winter, with about 83 percent of the population at risk. AIDS affects 1.2 percent of the population, with 70,000 people living with the virus and 4,800 deaths from the virus since the disease emerged. This is low compared to neighboring countries, but the World Health Organization notes that there is a “significant risk of rapid expansion” unless a prevention and education program can be put into place. Tuberculosis is also on the rise, with 1.5 cases per 1,000 people. While there is both a public and a private healthcare system, the Niger’s medical system is largely funded by international humanitarian groups. Facilities are poorly distributed around the country; about 50 percent of the population has no access to medical care. There is an average of one clinic for every 25,000 people. Patients have to pay high fees for service, but facilities, equipment, and quality of care is poor. Hospitals are also inadequately staffed. There are currently 377 physicians, 2,716 nurses, 21 midwives, and 15 dentists working in the country. SEE ALSO: Disease and Poverty; Healthcare, Africa.
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Bibliography. World Bank. Public Expenditure Management and Financial Accountability in Niger (World Bank Publications, 2005); “Niger,” CIA World Factbook, www. cia.gov (cited July 2007).
Heather K. Michon Independent Scholar
Nigeria Nigeria is located in west Africa on the Gulf of Guinea, bordered by Cameroon, Chad, Niger, and Benin. It is the most populous nation on the continent and home to one in four Africans. It is a beautiful land with tremendous biodiversity, not to mention a rich heritage and culture, but its promise is undermined by corruption, inequality, poverty, and disease. The current population is around 131.9 million, growing at 2.38 percent. Most of this is through natural increase, with 40.43 births per 1,000 people, 16.94 deaths per 1,000 people, and 0.27 migrants per 1,000 people. Almost half of the population lives in urban areas, and population density is high at 132 people per square kilometer. Nigeria is an important producer and exporter of petroleum and natural gas. However, crumbling infrastructure, mismanagement, corruption, and internal violence have kept the country and its people from enjoying the financial benefits from the industry. Per capita income in Nigeria is $390 annually, with 70 percent of the population living on less than $1 a day. Life expectancy at birth is 47.5 year for males and 47.7 years for females, with healthy life expectancy at 41.3 years for men and 41.8 years for women. Infant mortality is 120 deaths per 1,000 births. Child mortality (ages 1 to 5) is 197 deaths per 1,000 children. Maternal mortality is 800 deaths per 100,000 live births. Many children who survive those early years still face difficult lives. About 15 million children are believed to be in the workforce. Seven million children have lost one or both parents to disease or violence. Nigeria is deeply involved in child trafficking, moving young people both in and out of the country. Infectious disease is the main killer of Nigerians. Lassa fever is endemic in many areas, as is diarrhea, hepatitis A, malaria, meningitis, onchocerciasis (river
1242 Nirenberg, Marshall W. blindness), typhoid, schistosomiasis, and elephantiasis (lymphatic filariasis). Tuberculosis rates have risen as the AIDS epidemic has deepened. Recent years have also seen outbreaks of cholera, meningitis, and yellow fever. Few Nigerians have reliable access to clean water and only 38 percent have access to sanitary facilities. Nigeria does not have the highest AIDS rate in the world, but its sheer size gives it one of the largest human immunodeficiency virus (HIV)-positive populations. Exactly how large that population is unclear; estimates of prevalence range from 5.4 to 8 percent of the total population, with 3.6 to 5.4 million infections. In 2000, the government established the National Action Committee on AIDS to coordinate education and prevention programs. In 2005, the World Health Organization estimated that 636,000 Nigerians needed antiretroviral drugs; only 31,694 were receiving them. At an annual cost of $368 per person, the cost of drug therapy is prohibitive for many patients. The government has announced that the country will start producing cheaper generic antiretroviral drugs for AIDS patients. The medical establishment in Nigeria is large and diverse, but it does not begin to meet the needs of the population. The government allocates less than $20 per person on healthcare each year. The wealthy simply leave the country for specialized treatment; everyone else is forced to make do with what is available. Equipment is outdated and poorly distributed outside the cities. The market is flooded with counterfeit drugs. SEE ALSO: Disease and Poverty; Healthcare, Africa. Bibliography. Mary Adekson, The Yoruba Traditional
Healers of Nigeria (Routledge, 2004); “Niger,ia” CIA World Factbook, www.cia.gov (cited July 2007).. Heather K. Michon Independent Scholar
Nirenberg, Marshall W. (1927– ) Born on April 10, 1927 in New York City to Harry and Minerva (née Bykowsky) Nirenberg, Marshall War-
ren Nirenberg proved a core relationship among deoxyribonucleic acid (DNA), ribonucleic acid (RNA), amino acids, and cell protein. He, along with Robert William Holley and Har Gobind Khoraha, received the 1968 Nobel Prize for their discoveries. Nirenberg earned a Bachelor of Science degree in zoology and chemistry from the University of Florida in 1948 and a Master of Science degree in zoology from the same university in 1952. He earned his Ph.D. from the Department of Biological Chemistry at the University of Michigan in 1957. For the next two years, Nirenberg worked at the National Institutes of Health (NIH) for the National Institute of Arthritis, Metabolism and Digestive Diseases (NIAMDD). During this time, he also began delving into the correlations among DNA, RNA, and protein. Scientists were already aware that DNA contained a person’s genetic makeup; how DNA reproduced itself or oversaw protein in the human body, though, were yet unknown. Through his research, Nirenberg discovered the messenger role of RNA, demonstrating how RNA transmits information from DNA to instruct amino acids how to combine and form proteins. Nirenberg shared results of his findings at the International Congress of Biochemistry in Moscow in August 1961. In 1960, Nirenberg began serving as a research biochemist at the NIH Section of Metabolic Enzymes, and in 1962, he was chosen to lead the NIH Section of Biochemical Genetics at the National Heart Institute (NHI). In 1961, he married Perola Zaltzman, a chemist from the University of Brazil. Nirenberg received honorary degrees from numerous universities, including Yale and Harvard; he was given a significant number of awards as well, including the Molecular Biology Award from the National Academy of Sciences in 1962; the National Medal of Science in 1965; the Joseph Priestly Award in 1968; the National Medal of Honor by President Lyndon B. Johnson in 1968; and the Lasker Award, along with Khorana, in 1968. During the last 30 years of his career, Nirenberg researched neurobiology. During the 1970s and 1980s, he provided leadership and direction in this scientific discipline. SEE ALSO: Genetic Code; Genetics; Genetic Transforma-
tion; National Heart, Lung, and Blood Institute (NHLBI).
Noise
Bibliography. “The Marshall W. Nirenberg Papers,” Pro-
files in Science, National Library of Medicine, http://profiles.nlm.nih.gov/JJ/Views/Exhibit/narrative/biographical. html (cited July 2007); Wilhelm Odelberg, ed., Les Prix Nobel en 1968 (Nobel Foundation, 1969), http://nobelprize. org/nobel_prizes/medicine/laureates/1968/nirenberg-bio. html (cited July 2007). Kelly Boyer Sagert Independent Scholar
Noise Noise is any generally undesired sound produced largely as a by-product of another physical activity. Although low levels of noise seem unavoidable and have little effect, sufficiently loud and/or persistent levels of noise can have serious negative impacts on human health and well-being. These impacts include behavioral change, sleeplessness, loss of hearing, work performance, communication ability, and cardiovascular effects. Causes of excessive noise include traffic and proximity to airports, occupational noise, construction, and loud music. The level of noise is measured in terms of decibels (dB). This logarithmic scale refers to the work of Alexander Graham Bell, the inventor of the telephone. A level of 80 dB causes annoyance and can lead to stress; a level of 90 dB or above can lead to permanent hearing loss. Proximity to heavy traffic, operating some heavy machinery (especially in factory or construction environments), or being a stage performer can all lead to suffering a level of noise in excess of this level. World Health Organization (WHO) guidelines require a maximum of 35 dB within classrooms to promote a good learning environment and 30 dB for the ability to sleep peacefully. The greatest component of noise pollution is provided by road traffic. Rules restricting the type and level of traffic permitted to travel in urban areas during the hours of night have existed since the time of ancient Rome. Yet, despite improvements in road technology and noise reduction in vehicles, the sheer weight of traffic causes problems for many millions of people around the world every day. On a typical weekday in Bangkok, for example, official figures show noise lev-
1243
els in different parts of the city ranging from 65.9 to 74.6 dB (daily average). Within the European Union, it is estimated that 40 percent of the total population is exposed to traffic noise of 55 dB or more daily and 20 percent to noise measuring 65 dB or more. Economic development is no protection from this form of pollution. However, there is evidence to suggest that some traffic and zoning decisions are made in such a way that less well-advantaged communities suffer disproportionately. This partly results from differential levels of policing of existing laws as well as opaque planning decisions. Within urban environments, state- and national-level regulations might apply, although monitoring such issues might represent a low policing priority. In some cases, organization of local people to monitor and measure noise might be
The impacts of noise pollution can include behavioral change, sleeplessness, loss of hearing, and cardiovascular effects.
1244 Non-Hodgkin Lymphoma helpful in bringing nuisances caused by noise to the attention of the authorities. It is a significant part of life in many urban and suburban communities to become often acutely aware of noise pollution from car theft sirens, night clubs, illegal car racing, and other activities that are tackled by police only after extensive exposure to the nuisance. In 1977, the International Labor Organization (ILO) of the United Nations adopted Convention C148, which concerns the working environment (air pollution, noise, and vibration). The Convention defines noise as “all sound which can result in hearing impairment or be harmful to health or otherwise dangerous.” It lays out the responsibilities of governments and of employers to be aware of the issues of noise pollution and to take such measures as may be required to limit the exposure of workers to the problem. It also lays out the responsibility of workers to comply with measures put in place to protect them from noise and other types of pollution. However, it is clear that many millions of people within the developing world do not receive this protection properly or do not protect themselves accordingly. Within a domestic situation, people should be aware of excessive noise levels received by individuals and watch for behavioral change such as irritability, loss of concentration, or loss of communication skills. Medical advice might be sought in such circumstances. SEE ALSO: Hearing Problems in Children. Bibliography. Birgitta Berglund, Thomas Lindvall, and
Dietrich H. Schwela, eds., Guidelines for Community Noise (WHO, 1999); International Labor Organization, “C148 Working Environment (Air Pollution, Noise and Vibration) Convention, 1977,” http://www.ilo.org/ilolex/cgi-lex/convde.pl?C148 (cited May 2007); Pollution Control Development, Ministry of Natural Resources and Environment, “Bangkok Noise Level,’ http://gendb.pcd.go.th/NOISE/en_ noiselevel.asp (cited May 2007); S. P. Singal, Noise Pollution and Control Strategy (Alpha Science International, 2005); Robin R. Sobotta, Heather E. Campbell, and Beverly J. Owens, “Aviation Noise and Environmental Justice: The Barrio Barrier,” Journal of Regional Science (v.47/1, 2007). John Walsh Shinawatra University
Non-Hodgkin Lymphoma Lymphomas are cancers of the lymphoid tissues. Lymphomas may develop in any organ associated with the lymphatic system, such as lymph nodes and extranodal tissue. Thus, there are lymphomas of the spleen, stomach, intestine, skin, central nervous system, and so forth. There are two major types of lymphomas: Hodgkin lymphoma (or Hodgkin disease) and non-Hodgkin lymphoma (NHL). While they both arise from the lymphatic system, Hodgkin lymphoma and non-Hodgkin lymphoma are two very different diseases with respect to the epidemiology, etiology, treatment, and prognosis. NHL includes all the lymphomas excluding Hodgkin lymphoma. By definition, NHL is not a single disease, but a heterogeneous group of lymphocytic disorders ranging in aggressiveness from very indolent cellular proliferation to highly aggressive and rapidly proliferative processes. The diseases arise from the lymphocytes, and based on cell type, NHLs can be divided into B-cell NHL and T-cell and NK-cell NHLs. The most frequent lymphomas are B-cell lymphomas. Among B-cell lymphomas, the diffuse large B-cell lymphomas are the most frequent. The second most frequent B-cell lymphomas are follicular lymphomas. There are various less frequent types of B-cell neoplasms including marginal zone B-cell lymphomas, mantle cell lymphomas, and chronic lymphocytic leukemias/B-cell lymphocytic lymphomas. T-cell and NK-cell lymphomas are less frequent and usually have a worse prognosis. There are numerous clinical and pathological classification schemes for NHL over the past decades, from categorization predominantly by morphology (Rappaport classification), or by morphology and clinical prognosis (Working Formulation), or by cell lineage and differentiation (Lukes and Collins or Kiel classifications), or by incorporating morphologic, immunophenotypic, genotypic, and clinical features into disease subtype definitions (the Revised European-American Lymphoma classification, World Health Organization classification). Epidemiology More than 288,000 persons will be diagnosed with NHL each year worldwide. NHL has the fifth highest cancer incidence in the United States. It is estimat-
ed that over 63,190 persons will be diagnosed with NHL and 18,680 will die from the disease in 2007 in the United States. Men have about 30 percent higher age-adjusted incidence rate of NHL than women. The incidence rate of NHL is low before 30 years of age, and after that, the rate increases continuously and rapidly with age, and peaks at the oldest ages. The disease is most common in the developed countries. In the United States, white men and women have about 1.5 times the age-adjusted incidence rate of black men and women, while Asians have lower rates than whites and blacks. Over the past several decades, incidence rates of NHL have been reported to be increasing dramatically throughout the world among both men and women. In fact, the reports in the 1990s showed that the increase in the incidence rate for NHL exceeded the increased incidence for all other types of cancer except melanoma and lung cancer in the United States. More recent reports from both the United States and Europe, however, indicate that the epidemic increase of NHL appears to have subsided. The changes in NHL time patterns, however, appear to vary by NHL subtype and by age. For example, the European study showed that the NHL incidence increased in both genders and all age categories by about 4 percent every year up until the early 1990s. Thereafter, the incidence increased at a slower rate (ages 60 to 79 years), stabilized (ages 50 to 59 and > or =80 years), and decreased (ages 0 to 49 years), respectively. Etiology Despite the increase in NHL incidence and an intensification of epidemiologic investigations into the etiology of NHL, few concrete risk factors for NHL have been identified. Primary or acquired immunosuppression. NHL risk has been strongly and consistently associated with various inherited or acquired immunosuppressions. A more than 100-fold increased risk of NHL was observed among people with immune deficiency associated with immune suppressive therapy after transplantation, human immunodeficiency virus (HIV)/AIDS, and congenital conditions. Autoimmune diseases (such as rheumatoid arthritis, Sjogren’s syndrome, systemic lupus erythematosus, psoriasis, and coeliac disease) have also been associated with NHL risk. However, these severe deficiencies
Non-Hodgkin Lymphoma 1245 and autoimmune diseases are relatively rare and cannot explain the increase in NHL incidence observed in the population. Ultraviolet Radiation (UVR). Increasing exposure to UVR from sun exposure was hypothesized to be responsible for at least part of the observed increase in NHL based on the following observations: sun exposure causes immune suppression and immunosuppression for other reasons is the established risk factor for NHL; the increase in incidence of NHL parallels with that of malignant melanoma; and risk of NHL was found to be associated with skin cancer and vice versa. This hypothesis is not supported by all epidemiological studies. Recent studies, in fact, found that UVR may be associated with a reduced risk of NHL. An increased production of vitamin D has been suggested to be the underlying mechanism for the observed protection because vitamin D is important in regulating cell proliferation and differentiation, apoptosis, tumor progression, and angiogenesis. Virus and Infections. A recent review by Engels has concluded that among exposures presently viewed as possible etiologic factors in NHL, infections are close to being regarded as established causes. Engels classified infectious agents causing NHL into three broad groups according to mechanism. First, some viruses that can directly transform lymphocytes. These include Epstein-Barr virus (linked to Burkitt’s lymphoma, NHLs in immunosuppressed individuals, and extranodal natural killer/Tcell NHL), human herpesvirus 8 (primary effusion lymphoma), and human T lymphotropic virus type I (adult T-cell leukemia/lymphoma). Second, HIV which causes profound depletion of CD4(+) T lymphocytes, leading to aggressive B-cell lymphoma. Third, some infections (such as hepatitis C virus, HBV infection, and Helicobacter pylori infection) which increase NHL risk through chronic immune stimulation. These infections appear to increase risk for localized mucosa-associated lymphoid tissue NHLs. Hair Coloring Product Use. Personal use of hair coloring products has been suggested to be the risk factor for NHL based on the facts that carcinogenic aromatic, nitroso, and amino compounds have been found in hair coloring products and experimental studies support an association. Epidemiological
1246 Non-Hodgkin Lymphoma studies of hair coloring product use and NHL risk, however, have yielded inconsistent results. Recent epidemiological studies, which have detailed information on hair dye use, showed that permanent black hair dye use may be associated with a moderate increase in NHL risk, particularly among women who used dyes before 1980. It is currently unclear whether the observed association reflects the change in hair dye formula contents during the past two decades or indicates that recent users are still in their induction and latent periods. Chemicals and Metals. Epidemiological studies have suggested an increased risk of NHL associated with chemical exposures, such as pesticides (particularly phenoxyherbicides and carbamates), PCBs, formaldehyde, plastic/rubber chemicals, organic solvents, lead/lead arsenate, wood preservatives, and welding metal fumes. None of these factors, however, have been adequately studied and no conclusion can be drawn at this time for the alleged association. Diet and Nutrients. Epidemiological studies have suggested that dietary factors may influence NHL risk. Particularly, higher consumption of animal protein and fats may increase the risk of NHL. Food represents an important antigenic challenge to the immune system. Diets high in animal protein may lead to chronic antigenic stimulation which could induce a state of immune unresponsiveness or oral tolerance and possibly an elevated lymphoma risk. Protein and other macromolecules that are not fully degraded can be absorbed into the blood stream and induce an antigenic response. Fat in the diet could also influence immune function either through actions on the cyclooxygenase, lipoxygenase, or cytochrome p450 pathways or directly on cell function through effects on cell membrane structure and function. Experimental studies have shown that rats fed diets high in protein are at increased risk of developing lymphoma. On the other hand, one carbon nutrients (such as folate, methionine, B2, B6, and B12) have been suggested to be associated with a reduced risk of NHL. Deficiencies in folate and other one-carbon nutrients can impair DNA methylation and cause disruption of DNA integrity and DNA repair which can lead to carcinogenesis. In addition, deficiencies in folate, vitamin B12, and methionine can lead to impaired immune responses,
Tobacco Smoking and Alcohol Drinking. Unlike many human cancers, tobacco smoking is not considered to be associated with the risk of NHL overall. Some studies, however, suggest that smoking may be weakly positively associated with risk of follicular NHL. The Majority of the epidemiological studies suggest that alcohol consumption may reduce the risk of non-Hodgkin lymphoma. A recent pooled analysis involving 15,175 individuals (6,492 cases and 8,683 controls) using data from the International Lymphoma Epidemiology Consortium (InterLymph) showed that people who drank alcohol had a significantly 17 percent lower risk of NHL than did non-drinkers. While the protective effect of alcohol did not vary by beverage type, but did change with NHL subtype. The suggested mechanism for a reduced risk of NHL associated with alcohol drinking is that light to moderate alcohol drinking (ie, up to one drink a day for women and two drinks a day for men) might improve cellular and humoral immune responses. Alcohol might also reduce the risk of NHL indirectly by increasing insulin sensitivity in healthy individuals. Gene Polymorphisms. Studies have reported that polymorphisms in immune and inflammatory response genes, particularly polymorphisms in TNF and IL10, are associated with an increased risk of NHL. Cytokine polymorphisms in the Th1/Th2 pathway have also been linked to the NHL risk. Studies of oxidative stress genes show that genetic variations that result in an increased generation of reactive oxygen species appear to increase risk for NHL and its major subtypes, particularly DLBCL. Genetic polymorphisms in DNA repair genes, particularly ERCC5 and WRN, may play a role in the pathogenesis of NHL. Genes responsible for circadian rhythm, particularly neuronal PAS domain protein 2 (NPAS2), appear to be involved in NHL risk. Studies also show that genetic polymorphisms in one-carbon genes, and BCL6 gene may have also contributed to the etiology of NHL. Few studies have so far investigated the issue of gene-environment interaction, which will eventually help to answer the question how genetic polymorphisms are involved in the observed rapid increase in NHL incidence. In summary, in spite of the considerable public health significance of NHL, little is known about its etiology and the factors responsible for its rapid in-
crease in incidence. While great efforts and progress have been made in epidemiological study of the etiology of NHL, the established risk factors can only explain a small proportion of the disease. Clinical Symptoms may vary from patient to patient. Treatment of the disease and the subsequent survival can be affected by many factors. Symptoms. Clinical presentation varies with the aggressiveness of the disease and the localizations involved. The main symptoms are enlarged lymph nodes anywhere in the body that can be responsible for compression and enlarged liver or spleen. Patients can present with general symptoms (such as fever, weight loss, night sweats, fatigue), chest pain, shortness of breath. Stages The staging system is based on the Ann Arbor classification, similar to the one used for Hodgkin’s disease. Full clinical examination, CT-scans, PET-scans, bone marrow biopsies, lumbar punctures are useful to assess the extent of the disease. Treatment. A number of factors may affect the treatment options for patients with NHL. The most important factors affecting treatment options are histological subtype ,the stage of the disease and the patient’s past medical history. The treatment can be based on chemotherapy and immunotherapy with monoclonal antibodies. Radiotherapy can be used in some cases. For example, diffuse B-cell lymphomas are treated with doxorubicin based chemotherapy, such as CHOP (cyclophosphamide, doxorubicin, vincristine and prednisone). The adjunction of rituximab (a chimeric monoclonal anti-CD20 antibody) has improved the survival of these patients. Autologous peripheral-blood stem cell transplantations can be used as salvage therapy for relapsing DBCL. It is also being assessed as a first line treatment for high-risk patients. Dose dense and dose intense regimens are being developed to improve survival. Adapted treatment for elderly patients is also under evaluation. Follicular lymphomas are usually treated with chemotherapy and rituximab. Radiotherapy can be used to treat localized stages. Watch and wait can be an option if patients have little or no symptoms or organ dysfunction. Rituximab can be used as a maintenance therapy to try and improve relapse free survival. Some patients
Non-Hodgkin Lymphoma 1247 are treated with autologous peripheral-blood stem cell transplantation, mainly at relapse. Radiolabelled antibodies are also being developed for treating follicular lymphoma in association with chemotherapy or alone. Mantle cell lymphomas can be treated with R-CHOP type chemotherapy. More intensive regimens such as R-hyperCVAD (Rituximab+cyclophosphamide, vincristine doxorubicin, dexamethasone, alternating with rituximab- cytarabine and methotrexate) and /or autologous peripheral-stem cell transplantation are being studied in this setting. T-cell lymphomas represent 10 to 15 percent of all lymphomas. Primary cutaneous T-cell lymphomas are a group of lymphoproliferative disease that involve the skin and can extend to other organs. The most frequent sub-types are mycosis fungoides and Sezary syndrome. Mycosis fungoides is a low-grade disorder that evolves slowly to lymph node and organ involvement. A wide range of treatments can be used: local topics to allogeneic bone marrow transplantation, passing by standard dose chemotherapy. Peripheral T-cell lymphomas are aggressive tumors with poor response to conventional chemotherapy. The impact of more intense chemotherapy and of autologous or allogeneic transplantation on survival is being studied. Survival Prognosis depends on the histology, the extent of the disease, the patient’s performance status, his past medical history, the presence of B symptoms (weight loss> 10 percent, night sweats, fever) and biological markers. The International NHL Prognostic Factors Project developed in 1993 a predictive model for aggressive lymphomas. It is based on patient’s age, performance status (PS), stage of disease, serum LDH (lactate dehydrogenase) levels and number of extranodal sites involved. Adverse risk factors are age over 60, PS ≥2, stage III or IV, increased levels of LDH, more than one extranodal site involved. Four risk groups were thus identified: low, intermediate-low, intermediate-high and high risk. A simplified model for younger patients (the age-adjusted international index) was also developed. It is based on tumour stage, LDH level, and performance status. Similar prognostic models have been developed for other histological subtypes (eg FLIPI for follicular lymphomas) Indolent lymphomas usually respond to treatment but relapse. Nevertheless overall survival tends to be long. Diffuse B-cell lymphomas have a more aggressive presenta-
1248 Nonsense Mutation tion but respond very well to chemotherapy with possibility for cure. Mantle-cell lymphomas have good response rates to therapy but rapid relapse with a poor overall survival (median: 3 years). SEE ALSO: Cancer (General); Lymphatic Diseases. Bibliography. F. Bertoni and E. Zucca, “State-of-the-
Art Therapeutics: Marginal-Zone Lymphoma,” Journal of Clinical Oncology (v.23/26, 2005); B. Coiffier, “State-ofthe-Art Therapeutics: Diffuse Large B-cell Lymphoma,” Journal of Clinical Oncology (v.23/26, 2005); S. de Sanjose, et al., “Association Between Personal Use of Hair Dyes and Lymphoid Neoplasms in Europe,” American Journal of Epidemiology (v. 164/1, 2006); E.A. Engels, “Infectious Agents as Causes of Non-Hodgkin Lymphoma,” Cancer Epidemiology Biomarkers & Prevention (v.16/3, 2007); L.S. Evans LS and B.W. Hancock, “Non-Hodgkin Lymphoma,” Lancet (v.362/9378, 2003); B.T. Hennessy, E.O. Hanrahan, and P.A. Daly, “Non-Hodgkin Lymphoma: an Update,” Lancet Oncology (v.5/6, 2004); W. Hiddemann, et al., “Treatment Strategies in Follicular Lymphomas: Current Status and Future Perspectives,” Journal of Clinical Oncology (v.23/26, 2005); E.S. Jaffe, et al., “Pathology and Genetics: Neoplasms of the Haematopoietic and Lymphoid Tissues,” World Health Organization Classification of Tumors, P. Kleihaus and L. Sobin, eds. ( IARC Press, 2001); A. Jemal, et al., “Cancer Statistics, 2007,” CA: A Cancer Journal for Clinicians (v.57, 2007); Q. Lan, et al., “Cytokine Polymorphisms in the Th1/Th2 Pathway and Susceptibility to Non-Hodgkin Lymphoma,” Blood (v.107/10, 2006); L.M. Morton, et al., “Cigarette Smoking and Risk of Non-Hodgkin Lymphoma: a Pooled Analysis from the International Lymphoma Epidemiology Consortium (interlymph),” Cancer Epidemiology Biomarkers & Prevention (v.14/4, 2005); L.M. Morton, et al., “Alcohol Consumption and Risk of Non-Hodgkin Lymphoma: a Pooled Analysis,” Lancet Oncology (v.6/7, 2005); L.M. Morton, et al., “Hepatitis C Virus and Risk of Non-Hodgkin Lymphoma: A Population-Based Case-Control Study among Connecticut Women,” Cancer Epidemiology Biomarkers & Prevention (v.13, 2004); M. Shen, et al., “Polymorphisms in DNA Repair Genes and Risk of Non-Hodgkin Lymphoma among Women in Connecticut,” The American Journal of Human Genetics (v.119/6, 2006); B.W. Steward and P. Kleihues, eds., World Cancer Report (IARC Press, 2003); T.E. Witzig, “Current Treatment Approaches for MantleCell Lymphoma, Journal of Clinical Oncology (v.23/26,
2005); Y. Zhang, et al., “Hair-Coloring Product Use and Risk of Non-Hodgkin’s Lymphoma: a Population-Based Case-Control Study in Connecticut,” American Journal of Epidemiology (v.159/2, 2004); Y. Zhang, et al., “A Putative Exonic Splicing Polymorphism in the BCL6 Gene and the Risk of Non-Hodgkin Lymphoma,” Journal of the National Cancer Institute (v.91/21, 2005); T. Zheng, et al., “Diet and Nutrient Intakes and Risk of Non-Hodgkin’s Lymphoma in Connecticut Women,” American Journal of Epidemiology (v.159/5, 2004); T. Zheng, et al., “Risk of Non-Hodgkin’s Lymphoma and Chronic Lymphocytic Leukemia,” Journal of Occupational and Environmental Medicine (v.44, 2002); T. Zheng, et al., “Agricultural Exposure to Carbamate Pesticides and Risk of Non-Hodgkin’s Lymphoma,” Journal of Occupational and Environmental Medicine (v.43, 2001). Tongzhang Zheng Yale University Helen Boyle Independent Scholar Yawei Zhang General Editor Peter Boyle International Agency for Research on Cancer
Nonsense Mutation Normally, messenger ribonucleic acid (mRNA) translation to protein is terminated by one of three stop codons. A point mutation that converts a codon for a normal amino acid into a stop codon is called a nonsense mutation. The new, premature, stop codon is often termed a nonsense codon to highlight the true effect of such mutations: the creation of nonsensical mRNA transcripts which translate into proteins that are typically nonfunctional. Contrast this with a normally located stop codon which properly regulates the length of proteins created from an mRNA transcript. In general, such mutations do not alter the activity of transcription (which is terminated by mechanisms distinct from the stop codon). However, mRNA transcripts containing nonsense mutations are usually highly unstable and decay before translation can occur. This evolutionarily advantageous mechanism helps cells conserve resources by not expending energy on the production of proteins with limited, nonexistent,
North American Association for the Study of Obesity (NAASO)
or malignant functionality. If mRNA with a nonsense mutation happens to be translated into a protein sequence, the protein itself is often so unstable that it is targeted by the cell for destruction. While the complete abolition of protein function caused by such mutations would seem to make them good candidates for disease causation, they make up only 12 percent of all disease causing mutants. The most likely explanation for this is that the complete loss of protein function is often incompatible with life, meaning very few children are born with such mutations. Furthermore, many of those who develop such mutations spontaneously in adulthood likely never develop disease because the complete abolition of certain protein functions so radically alters homeostasis on a cellular level that programmed cell death is initiated, limiting the potential for such a mutation to cause disease. SEE ALSO: Missense Mutation; Point Mutation; Pro-
grammed Cell Death.
BIBLIOGRAPHY. R. L. Nussbaum, et al., Thompson &
Thompson: Genetics in Medicine, revised reprint (Saunders, 2004); Lorri A. Zipperer, ed., The Health Care Almanac: A Resource Guide to the Medical Field (American Medical Association, 1995). Bimal P. Chaudhari Boston University
North American Association for the Study of Obesity (NAASO) Since 1982, the North American Association for the Study of Obesity (NAASO) has been pursuing the study of obesity, which is defined as being overweight to the point that health is impaired. Weight-related conditions include diabetes, heart disease, hypertension, stroke, some cancers, sleep apnea, osteoarthritis, and gallbladder disease. Studies suggest that roughly a third of the population is obese, and 64 percent of Americans are overweight. Those numbers are increasing in response to unhealthy diets and less active
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lifestyles. NAASO battles obesity through research into causes and treatments and by communicating with healthcare professionals and the public about the results of that research. In order to pursue its vision of preventing and treating obesity and improving the quality of life among the obese population, NAASO is also involved in educating Americans about obesity. Advocacy efforts are also essential in achieving society goals, and NASSO lobbies for increased funding for obesity research and promotes enhanced understanding of the disease and how it affects the lives of those who experience it. The society has around 2,000 members, including both basic and clinical researchers and healthcare providers who specialize in obesity treatment and prevention. NAASO is located at 8630 Fenton Street, Suite 918, Silver Spring, Maryland 20910. Information is available by telephone (301-563-6526) or on the World Wide Web (http://www.naaso.org/). NAASO’s governing body includes the president, president-elect, vice president, immediate past-president, the secretary/treasurer, and several councilors. NAASO regularly publishes Obesity, a scholarly journal that presents research findings and offers reviews, commentaries, and public health and medical news. The most widely read articles that have appeared in Obesity deal with the subjects of childhood obesity, discrimination against the obese, behavioral methods for promoting weight loss, obesity treatments, and obesity on a global scale. An e-mailed newsletter keeps members up to date on relevant news. NAASO recently launched Obesity Online, a virtual meeting that is available free of charge to primary care physicians, obesity and diabetes specialists, and others in the health profession who deal with the obese. The services use the results of case studies to examine behavior modification techniques, very low calorie diets, and weight gain in patients who have had bariatric surgery. A good deal of NAASO attention is focused on the social stigma that often accompanies obesity. Those who are obese may experience discrimination in employment, education, medical facilities, the media, and interpersonal relationships. Negative behaviors directed at individuals, particularly at children, who are overweight include ridicule, teasing, insults, stereo types, and name calling. People who are obese often find that chairs in public places may be too small or
1250 Norway discover that medical equipment is not suited for larger bodies. Clothing for the obese is more difficult to find and generally carries a higher price tag than those designed for other individuals. Employers may be reluctant to hire obese people because they are often viewed as lazy, sloppy, less competent, and more disagreeable. Their wages may be lower and they are less likely to be promoted. Weight stigma may lead to depression, anxiety, social isolation, and poorer psychological adjustment and self-esteem than is common in the general population. Numerous studies have shown that people who are obese are less likely to have regular checkups and are more likely to cancel medical appointments. SEE ALSO: Obesity. BIBLIOGRAPHY. Per Bjorntorp, ed., International Text-
book of Obesity (Wiley, 2001); Linda A. Ferrera, ed., Focus on Body Mass Index and Health Research (Nova Science, 2006); Igor Harsch, ed., The Various Types and Treatments for Obesity (Nova Science, 2006); Evelyn B. Kelly, Obesity (Greenwood, 2006); Peter R. Ling, ed., Trends in Obesity Research (Nova Biomedical Books, 2005); North American Association for the Study of Obesity, http://www.naaso.org/ (cited July 2007); Thomas A. Wadden and Albert J. Stunkard, eds., Handbook of Obesity Treatment (Guilford, 2002).
Elizabeth R. Purdy, Ph.D. Independent Scholar
Norway According to the United Nations Development Programme (UNDP) Human Development Reports, Norway has the highest standard of living in the world. The government provides an extensive social welfare system that claims 35 percent of the total budget. With a per capita income of $42,800, Norway is the sixth richest nation. Much of that income is derived from the oil and gas resources that were discovered in the area in the late 1960s. The Norwegian government has implemented measures to protect the country from depletion of wealth as resources are exhausted by investing abroad, and the Government Petroleum Fund is now
valued at more than $250 billion. The economy of Norway is growing at a rate of 4 percent annually, and unemployment (4.0 percent) and inflation (1.6 percent) are under control. The government has developed policies designed to eradicate poverty and limit social exclusion. The extensive welfare program has produced a relatively equal distribution of income, and Norway ranks 25.8 on the Gini Index of Inequality. The richest 10 percent hold 21.8 percent of wealth, and the poorest 10 percent share 4.1 percent of wealth. Although the National Insurance Scheme provides some funding for healthcare, programs are chiefly funded by state, county, and municipal taxes and through mandatory worker and employer contributions. Governments at all three levels are joined together to provide healthcare to Norwegians. The major responsibility for overseeing and financing healthcare lies with each state. Involvement at the county level is generally concentrated on providing hospitals and special services; and municipalities are concerned with oversight of medical activities, preventive services, rehabilitation, nursing homes, and home care. Copayments are required for primary healthcare and emergency treatment, but hospital inpatient treatment is provided free of charge. Norwegians are highly committed to promoting health, and 16 percent of the total budget is expended on healthcare. Of the total Gross Domestic Product (GDP), 10.3 percent is used for health-related programs, and the government allots $3,809 (international dollars) per capita to fund health initiatives. Government spending as a percentage of total expenses amounts to 83.7 percent, with 17.9 percent expended on social security, which covers the elderly, the seriously ill, and the unemployed. The private sector produces 16.3 percent of total health spending, and 95.4 percent of that amount is derived from out-of-pocket expenses. There are 3.13 physicians, 14.84 nurses, 0.49 midwives, 0.82 dentists, and 0.37 pharmacists per 1,000 population in Norway. Norway’s population of 4,610,820 experiences a life expectancy of 79.54 years, which is the 20th highest ranking among nations of the world. On average, females outlive males by five years. All Norwegians over the age of 15 can read and write, and 100 percent of the relevant population is enrolled in primary and secondary school. The entire population has access to safe drinking water and improved sanitation. Nearly three-fourths of Norwegian women
use birth control, giving birth at a rate of 1.78 children per female. All births are attended by trained personnel. The adjusted maternal mortality rate is 16 deaths per 100,000 live births. Norway has the seventh lowest infant mortality rate in the world, and the government reports a current infant mortality rate of 3.68 deaths per 1,000 live births. Between 1990 and 2004, infant mortality fell from 7 to 4 deaths per 1,000 live births. During that same period, under-5 mortality dropped from 9 to 4 deaths per 1,000 live births. Despite the general good health of the population, 5 percent of all infants are underweight at birth. Ninety-seven percent of all infants are immunized against Haemophilus influenzae type B, and 93 percent receive diphtheria, pertussis, and tetanus (DPT1 and DPT3) and polio vaccinations. Among infants immunized against measles, the percentage of inoculations falls to 88 percent. Environmentally, Norwegians are adversely affected by water and air pollution that is produced by various industries. Some 2,100 people in Norway are living with HIV/AIDS, and the government reports an adult prevalence rate of 0.1 percent. Because of advancing medical technology and effective treatment, less than 100 people have died from this potentially fatal disease. Other communicable diseases continue to pose varying levels of threat to Norwegians. Meningococcal disease surfaced in Norway in 2000 and 2001, and human influenza created health dilemmas in 2003 and 2004. Norway is also committed to improving global health. Under the auspices of the Geneva-based UNITAID, in September 2006, Norway joined France, Britain, Brazil, and Chile in earmarking tax revenues raised from increased airfares for programs designed to improve the health of children around the world. Program goals are to provide treatment for 200,000 people affected with AIDS, 150,000 children diagnosed with tuberculosis, and 28,000,000 infected with malaria. SEE ALSO: Healthcare, Europe. BIBLIOGRAPHY. Central Intelligence Agency, “Norway,”
World Factbook https://www.cia.gov/cia/publications/factbook/geos/no.html (cited June 2007); Commission on the Status of Women, “Norway,” http://www.un.org/women watch/daw/Review/responses/NORWAY-English.pdf (cit-
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ed June 2007); Spencer Di Scala, Twentieth Century Europe: Politics, Society, Culture (McGraw-Hill, 2004); Celia W. Dugger, “Five Nations to Tax Airfare to Raise Funds for AIDS Drugs,” New York Times Online (September 19, 2006); Sandra Halperin, War and Social Change in Modern Europe: The Great Transformation Revisited (Cambridge University Press, 2004); Martin A. Levin and Martin Shapiro, eds., Transatlantic Policymaking in an Age of Austerity: Diversity and Drift (Georgetown University Press, 2004); Jeremy Rifkin, The European Dream: How Europe’s Vision of the Future Is Quietly Eclipsing the American Dream (Jeremy P. Tarcher/Penguin, 2004); Social Watch, “Norway,” http://www.socialwatch.org/en/fichasPais/156.html (cited July 2007); Peter Taylor-Gooby, New Risks, New Welfare: The Transformation of the European Welfare State (Oxford University Press, 2004); United Nations Children’s Fund, “Norway,” http://www.unicef.org/infobycountry/norway_ statistics.html (cited July 2007); World Bank, “Norway Data Profile,” http://devdata.worldbank.org/external/CPProfile. asp?PTYPE=CP&CCODE=NOR (cited June 2007); World Health Organization, “Highlights on Health in Norway,” http://www.euro.who.int/document/e72501.pdf (cited July 2007); World Health Organization, “Norway,” http://www. who.int/countries/nor/en (cited July 2007). Elizabeth R. Purdy, Ph.D. Independent Scholar
Nose Disorders The nose serves several important functions. Not only is it one of the most prominent facial features, impacting voice tone, but it also filters air entering the lungs, aids in our sense of smell, and protects against infection. Therefore, disorders of the nose can significantly impact an individual’s quality of life. Common nasal disorders include rhinitis, sinusitis, nasal polyps, snoring, nosebleeds, cancer, and deviated septum. Most nasal disorders are treatable with proper diagnosis and medical care. Rhinitis occurs when mucous membranes in the nose become inflamed, often in response to the body’s release of histamine secondary to airborne irritants such as allergens. The increased inflammation and fluid production in the nasal passages may cause breathing difficulties. Rhinitis has two basic causes:
1252 Nose Disorders (1) viral infection or (2) allergies, both with similar symptoms. The most common symptom is a runny nose, but others include congestion, postnasal drip, cough, sneezing, or itchiness in the nasal passages. Sinusitis may be acute or chronic and occurs when the sinus passages are blocked for an extended time, which causes swelling in the sinus lining and nasal congestion. Sinusitis often occurs with rhinitis, and may be either bacterial or viral. Chronic sinusitis may increase risk of nasal polyps (small growths in the nasal passages). A rhinoscope (flexible fiber optic camera for looking in the nose) may be used for diagnosis, especially if there is suspicion of nasal polyps. Nasal polyps are growths occurring in the nares created by chronic swelling/inflammation. Smaller polyps can be a minor bother, but larger ones can impede breathing and sense of smell. Polyps can also increase frequency of headaches or initiate snoring problems. Nasal polyps are more frequently seen in individuals with chronic sinus infections, asthma, cystic fibrosis, and hay fever, and can be successfully removed through surgery. Snoring is a sign of obstructed breathing occurring during sleep. Air flow is obstructed where the tongue and upper throat meet the soft palate and uvula. The audible noise of snoring results from vibration of these structures, and can disturb sleep patterns and cause sleep deprivation. Many factors are associated with snoring, including poor muscle tone, congested nasal passages, or nasal deformities. Mild snoring may be prevented by changes in lifestyle such as proper diet and exercise, establishing regular sleep habits, and avoiding heavy meals and alcohol before bed. However, chronic snorers may require further medical evaluation to rule out a more serious condition. Nosebleeds commonly occur in the front of the nose and are usually not serious, stopping quickly. Most severe nosebleeds are due to trauma, and some result from damage to large vessels in the back of the nose. Larger vessel nosebleeds can also result from high blood pressure, atherosclerosis, daily aspirin use or bleeding disorders and are more common among the elderly. Other factors that affect nosebleeds are acute or chronic infections, polyps, nose picking, or the inhalation of irritating substances. Medical treatment for
nosebleeds may include application of epinephrine to the nose, gauze packing, or a nasal balloon catheter. Antibiotics may be appropriate if packing is required for greater than a 24-hour period. Frequent nosebleeds may be the symptom of a more serious problem and should receive medical evaluation. Cancer of the paranasal sinus and nasal cavity is a rare disease. The paranasal sinuses are small hollow cavities located around the nose, including the frontal sinuses above the nose, the maxillary sinuses on both sides of the upper jawbone, the ethmoid sinuses located behind both sides of the upper nose, and the sphenoid sinus located behind the ethmoid sinus in the center of the skull. Air passes through the nasal cavities when inhaling or exhaling through the nose. Common symptoms of this type of cancer may include chronic sinus blockage, frequent headache, nosebleeds, lump or sores inside the nose, swelling around the eyes, or pain in the upper teeth. This cancer is usually identified through magnetic resonance imaging (MRI) or computerized tomography (CT) scan and treatment may include surgery, chemotherapy, or radiation. Deviated septum occurs when the septum is clearly shifted away from the midline, usually resulting from trauma to the nasal area, but can also be due to birth defects. The nasal septum is the wall dividing the nasal cavity at midline. It is composed of central supporting cartilage covered on both sides by mucous membrane. A deviated septum can cause difficulties in nasal breathing, often more severe on one side. Other symptoms may include nosebleeds, chronic sinusitis, headaches, postnasal drip, or noisy breathing. Corrective surgery is the treatment of choice for a deviated septum. SEE ALSO: Allergy; Cancer (General); Common Cold;
Headache and Migraine; National Institute of Allergy and Infectious Disease (NIAID); Respiratory Diseases (General); Sinusitis; Sleep Disorders; Taste and Smell Disorders; Viral Infections; Voice Disorders. BIBLIOGRAPHY. The American College of Allergy, Asthma
and Immunology Public Education on Sinusitis and Rhinitis, www.acaai.org/Public/about.htm (cited October 2006); Aina J. Gulya, Julianna A. Gulya, and William R. Wilson,
Nuclear Medicine
An Atlas of Ear, Nose and Throat Disorders (Taylor & Francis, 1999); Gregory W. Randolph, William R Wilson, and Joseph, B. Nadol, The Clinical Handbook of Ear, Nose and Throat Disorders (Parthenon, 2004). Gautam J. Desai, D.O. Elizabeth K. McClain, Ed.S. Kansas City University of Medicine and Biosciences, College of Osteopathic Medicine
Nuclear Medicine Nuclear medicine is one of the important medical aspects that employs the radiation and emission of the radioisotopes to extract functional and morphological information about the specific organs for diagnosing or treating their possible diseases. The heart, thyroid, kidney, bones, brain, liver, and many other organs can be easily imaged by different imaging techniques in nuclear medicine, and also disorders in their functionality can be easily revealed by imaging techniques in nuclear medicine. Also, in some cases, the radioisotopes can be used to treat malfunctioned and diseased organs. Diagnosis and therapy are two major applications of nuclear medicine in the medical field. Radioactive tracers and radiolabeled molecules are being widely used in diagnostic procedure in the field of nuclear medicine. Most of the radioactive tracers emit a few of the well-known particles such as gamma, beta, or alpha. Since the alpha and beta particles have a short range to pass the tissue and body organs, they can be easily absorbed inside the body and they also cannot be detected by most of the nuclear detectors which operate from outside of the body. On the contrary, gamma rays have a longer range and less chance of nuclear interaction with tissue. Therefore, gamma rays are good candidates for imaging techniques in nuclear medicine. A radioisotope should be bounded to a pharmaceutical carrier and this combination is called radiopharmaceutical. Each radiopharmaceutical has an effective half-life with respect to its biological and radioactive half-lives. Radiopharmaceutical effective half-life is one of the important parameters for choosing an appropriate radioisotope for both imaging and therapeutic applications. Diagnostic techniques in nuclear
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medicine employ different imaging modalities and provide reliable and unique information compared to the other techniques. Absorption of radiotracer in an organ with malfunction (hot spots) and regular absorption of radiotracer in normal organs (cold spots) enable physicians to distinguish and diagnose the level of abnormality in an organ. Nowadays, brain and heart imaging with single photon emission computed topography (SPECT) technique routinely are being used and is a part of American Cardiac Association protocol in coronary artery disease diagnosis procedure. Radioisotope and pharmaceutical technologies have been playing an important role in both diagnostic and therapeutic fields of nuclear medicine. These technologies have tied together and worked hand to hand to produce a variety set of radiopharmacies for different application of advanced imaging and therapeutic techniques. One of the most important and promising radioisotopes is beta+ (positron) particle. The positron’s mass is the same as an electron and carries the same charge of an electron but positive. This particle has recently opened a new door to medical physicists and researchers in this field. This particle produces two identifiable gamma rays with specific energy of 0.512 (MeV) after annihilation event. Therefore, this radioisotope can be directed and be absorbed inside the target organ for producing a couple of gamma with the same energy, which can easily pass through the body and be detected by nuclear detectors. The outcome of this is the positron emission tomography (PET) technique, which is one of the state-of-the-art imaging technologies in nuclear medicine, and helps to provide both functional and morphological information from the target organ in diagnosis procedure using positron annihilation mechanism. In a new combined imaging technique, PET and a computed X-ray tomography (CT) scan the patient and, after co-registration of the two images (PET-CT), provide with almost 30 percent better diagnosis than with traditional gamma camera alone. Therefore, the PET-CT imaging system is a very powerful and significant tool, which provides unique information on a wide variety of diseases including dementia to cardiovascular disease, brain diseases such as Parkinson’s and Alzheimer’s, and cancer. A distinct advantage of nuclear medicine imaging techniques compare to traditional imaging techniques (X-ray) is that both bone and soft tissue
1254 Nurses Health Study can be successfully imaged at the same time with a reasonable image contrast. Nuclear particles can interact and damage the body cells and tissue based on their type and energy. The type and strength of the interactions highly depends on the particle’s energy, particle’s structure, and type of the tissue. In therapeutic field, any substances or medication that emit a nuclear particle is called as source and the specific organ for treatment is called a target. The radioactive tracers are generally short-lived isotopes linked to the chemical compounds to permit specific physiological processes and distribution for further scrutinizing. Radioactive sources with therapeutic applications should be administered and directed to the target by injection, inhalation, or oral methods. Effective half-life directly affects the amount of the delivered dose to the target organ. Iodine-131 has been recognized as one of the useful and important radioisotopes with respect to its effective half-life and energy in the therapeutic field of nuclear medicine. This radiotracer (I-131) is being widely used for treating and imaging of the thyroid and other organs and is one of the most successful methods of thyroid cancer treatment. Also, Iodine-125 is another version or radioisotope of Iodine with application in imaging. Short-range particles are good candidates for therapeutic applications in nuclear medicine. Alpha and beta sources (short-range particles) are being widely used in therapeutic fields and are implemented by surgery methods as the internal sources for treatment. This kind of application is called as brachytherapy. The brachytherapy (short-range) procedure delivers less overall radiation to the adjacent organs of the target and more to the target. Also, this technique is more localized to the target organ and is cost effective. Dose uniformity and high dose-rate delivery is one of the distinct advantages of this method. As an example, treating leukemia might need to involve a bone marrow transplant, in which case, the defective bone marrow will first need to be killed off with a lethal dose of radiation before being replaced by healthy bone marrow from a donor. The amount of the radiopharmaceutical given to a patient is just sufficient to obtain the required information or delivering a required dose before its decay. In imaging technique, the radiation dose received is medically insignificant but in treatment, the lethal dose must be delivered to the target organ.
In both imaging and treatment branches of nuclear medicine, the patient experiences no pain and discomfort during the test, and after a short period of time, with respect to the effective half-life of the given radiopharmaceutical, there is no trace that the test was ever done. The noninvasive nature of nuclear medicine’s techniques and the ability to observe an organ functioning from outside of the body during treatment and imaging, together make this technique a powerful, reliable, and robust diagnostic and therapeutic tool in the field of medicine. SEE ALSO: Radiologist; Radiology. BIBLIOGRAPHY. Frederick L. Datz, Gamuts in Nuclear
Medicine (Mosby-Year Book, 1987); Leonard M. Freeman, Nuclear Medicine Annual (Lippincott, Williams & Wilkins, 1999); Leonard M. Freeman, Nuclear Medicine Annual (Lippincott, Williams & Wilkins, 2003); Leonard M. Freeman, Nuclear Medicine Annual (Lippincott, Williams & Wilkins, 2004); Anisah el Helou, H. Kriegel, and T.C. Telger, Atlas of Diagnostic Nuclear Medicine (Springer, 2001); Paul B. Hoffer, Year Book of Nuclear Medicine 1990 (Mosby-Year Book, 1990); Paul B. Hoffer, Year Book of Nuclear Medicine 1991 (Mosby-Year Book, 1991); Edward B. Silberstein and John G. McAfee, Differential Diagnosis in Nuclear Medicine (McGraw-Hill, 1984); John Merryfield Walker and Donald Margouleff, Clinical Manual of Nuclear Medicine (Appleton clinical manuals) (Appleton and Lange, 1983). Hassan Bagher-Ebadian Ali Mohammadi Rad Mohammad Gharipour
Nurses Health Study The Nurses Health Study (NHS) and its successor, the NHS II, are two of the largest prospective (forward-looking) studies ever conducted. The primary purpose of the studies is to investigate the risk factors for major chronic diseases among women. The original NHS study began in 1976 and was motivated by an interest in assessing the safety profile of oral contraceptive, which millions of women had recently begun taking. Approximately 122,000 married registered nurses between the ages of 30–55 were enrolled
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in the study and were asked to fill out questionnaires every two years. Topics initially included smoking, hormone use, and other chronic disease parameters. Eventually, other components were added including diet and nutrition assessments, quality-of-life measures, and blood and toenail samples. In the NHS II study, launched in 1989, investigators were interested in looking for contraceptive–cancer links in a younger cohort of women who may have begun oral contraceptives in adolescence. Approximately 116,000 registered nurses between the ages of 25 and 42 were included in this study, which measured a similar series of parameters as the NHS I. The NHS studies were based at Boston-area hospitals and funded by the U.S. National Institutes of Health. Over the past 30 years, the NHS has produced a wealth of epidemiological data on a wide range of topics. Some of the major findings from the first 20 years of the NHS are as follows: 1. Cigarette smoking is a major cause of heart disease and stroke, with the risk dropping significantly in those who quit smoking. Smoking is also associated with lung cancer, suicide, cataracts, diabetes, hip fractures, and colon cancer, but not breast cancer. Those who quit tend to gain about 6 pounds, on average, and their risk of death from any cause returns to that of a nonsmoker 10 to 14 years after quitting. 2. Current oral contraceptive use is associated with a small increase in breast cancer and cardiovascular disease risk, but not colon cancer, hip fractures, or diabetes. Hormone replacement therapy for more than five years was associated with a small increase in breast cancer risk, but a decrease in cardiovascular disease risk (this finding has since been challenged) and decreased risk of hip fractures. 3. Obesity was found to be strongly associated with increased risk of cardiovascular disease, diabetes, and gallstones; a weak association with colon cancer and breast cancer (now controversial); and a protective effect on risk for hip fractures. 4. Moderate alcohol use was found to be related weakly to breast cancer, colon polyps, and hip fractures, but it had a protective effect for diabetes, it decreased total mortality among older
women, and it decreased cardiovascular disease risk. 5. Certain dietary habits were found to be protective for or to increase risk for certain conditions including red meat increases colon cancer risk, trans fats increase cardiovascular risk, increased caffeine intake increases hip fracture risk, and vitamin E was found to be protective for cardiovascular disease but not for breast cancer. 6. Other disease associations were documented, including shift work and cardiovascular disease, vigorous activity decreases diabetes risk, blistering sunburns increase melanoma risk, family history of breast or colon cancer increases the risk of those diseases. The NHS continues today with more recent topics of investigation including dietary antioxidants, other nutritional factors, physical activity, regional fat distribution, postmenopausal estrogen and progestin replacement therapy, and biochemical markers including plasma lipids and apolipoproteins. Researchers are also interested in comparing the predictive capability of several biochemical and genetic markers of inflammation and endothelial activation for heart disease versus stroke in women. New molecular and genetic analysis techniques have added to the complexity and the utility of the more recent and future studies. Important results in the past few years (2002–2005) include the following: 1. Cognitive function was preserved better in women who took vitamin E supplements, but not in those who took other vitamins. Ibuprofen was also found to preserve cognitive function. Walking, already shown to decrease cardiovascular disease, osteoporosis, and certain types of cancer, was also shown to have a beneficial effect on memory. 2. Obesity, overweight, and, even high-normal weight were shown to be related to development of diabetes mellitus. Sixty percent of diabetes cases could be attributed to obesity and overweight. Losing weight decreases this risk. Obesity also increases the need for hip replacements, especially obesity at a young age, as well as the risk for endometrial, kidney, and certain types
1256 Nutrition of esophageal cancer. Other studies showed that physical activity lengthened lifespan regardless of weight, and that maintaining a steady weight was protective for breast cancer. 3. Extensive studies on postmenopausal hormones challenged previous studies by showing slight increases in blood clots in the legs and stroke, decreased risk of hip fractures, osteoporosis, and no effect on colon cancer, heart disease, lung blood clots, and death. 4. Other results include the finding that three servings of fruit and vegetables are protective against heart disease, a reaffirmation of the role of calcium and vitamin D in the prevention of osteoporosis and hip fractures, and the relationship between alcohol consumption and a slight increase in colon cancer risk. The NHS was the first of several studies to address the health research disparity between men and women. The Women’s Health Initiative (WHI), launched in 1991, was one of the largest studies to follow the NHS. The WHI used several different study designs including a randomized control trial, a large observational study, and a community prevention study. The purpose of the WHI was to investigate the common causes of death, disability, and impaired quality of life in postmenopausal women. The WHI focused on cardiovascular disease, cancer, and osteoporosis as well as other conditions. The NHS continues today with thousands of participants in almost every U.S. state. Its investigators produce dozens of peer-reviewed articles annually and contribute significantly to understanding risk factors for chronic diseases for women. By focusing specifically on women, the NHS set a precedent followed now by dozens of other studies, which have led to a better understanding of women’s health. SEE ALSO: Women’s Health (General). BIBLIOGRAPHY. The Nurses Health Study, http://www.
channing.harvard.edu/nhs (cited July 2007); Lorri A. Zipperer, ed., The Health Care Almanac: A Resource Guide to the Medical Field (American Medical Association, 1995). Barry Pakes, M.D., M.P.H. University of Toronto
Nutrition Securing adequate food supplies and necessary nutrition is a global concern. The production, distribution, and consumption of food are matters that concern governments, corporations, and individuals everywhere. The enormous growth in the population of the world, from about 3 billion people to over 6 billion between the end of World War II and the end of the century has captured the attention of many scientists. The projection that by 2050 there may be twelve billion people in the world raises the need for nutrition to high levels of concern. To feed adequately the billions of people currently living and soon to be born means that whole resources are needed to supply the food people need. Today, there are many issues dealing with food facing the world. In vast areas of the world, large numbers of people are malnourished. This is especially the case in the southern hemisphere. However, in contrast, in an increasing number of countries, mainly in the northern hemisphere, the larger issue is obesity. The problem of malnourishment is not a problem of an inadequate supply of food on a global basis, it is a distribution problem. The poor, especially in the third world, could have food directly supplied to them by wealthier nations. However, this would destroy the local markets and local farmers. More commonly the misdistribution of food is due to exploitation of the population by local elites, unscrupulous merchants, or by local warlords. Malnourishment occurs due to other factors as well, including poverty. Population growth has outstripped food supplies from traditional resources, and inefficient agricultural practices, political turmoil, and poor distribution of the world’s food supply contribute to malnourishment as well. In addition, environmental and weather conditions can affect food supply. Malnourishment adds to the fragility of the health of people. Without an adequate diet, they become vulnerable to diseases. Some of these are preventable nutrition deficiency diseases. In contrast, people who are overweight or obese, as are millions in the United States, are prone to diet related diseases. These include heart attacks caused by clogged arteries that developed blockages from fatty diets. Cancer, diabe-
tes, and many other illnesses are also thought to be caused by a poor diet. Nutrition comes from the Latin word (nutr) which means to nurture or to nourish. Nourishment is what sustains life. In the heathcare field, heath professionals having the central responsibility for applying nutritional science to individuals and to groups of people are those who practice dietetics. The nutritional care of patients, clients, and others is the responsibility of the registered dietitian (RD). In a clinical setting it is the clinical nutritional specialist. In the area of public health it is the public health nutritionist who is responsible for high-risk individuals and others. This responsibility includes the job of assessing the nutritional needs and community programs designed and implemented to meet those needs. Food is eaten to supply energy and nutrients for building and maintaining the body. It is not the case that any particular foods such as milk are needed to maintain health. Millions have lived long lives on what was available to eat, including foods designated as culturally accesible or desirable. to live well However, people eat for reasons other than survival. Prisoners in a concentration camp were able to subsist on rats if that was all that was available. However, eating can also involve dining in a social setting of family and friends during the vast number of meals consumed by people throughout their lives. This means that the 40-known nutrients (including vitamins and minerals) currently known are consumed not just to live, but to live well in the company of others. Sound nutrition is demonstrable by means of a well developed body, ideal weight for height ratio, good muscle development, good muscle tone, good posture, clear eyes, alert facial expressions, and having a good appetite and normal bodily functions. In the Book of Daniel (Chapter 1) in the Old Testament there is a story of a nutrition test that demonstrated that Daniel and his Jewish companions were healthier eating a vegetable diet than the youths who ate the Babylonian king’s rich food, including meat, from his table. The story was told for religious purposes but it illustrates the importance of good nutrition to good health.
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People who are well nourished are alert, active, and more productive than people who are lacking nourishment. They have more energy reserves and resist disease better. Some people consume diets that give them borderline nourishment. They are able to meet their minimum needs, but they do not have energy reserves to meet physiologic, metabolic, fetal or infant development needs adequately. People who have poor eating habits may have borderline nourishment. Or people living with stress or low incomes may suffer from borderline nourishment. A significant number of people in the United States have a borderline diet. Malnutrition occurs when the nutritional needs are not met. People who are malnourished do not have the nutritional reserves and energy to meet the stresses of life. These are often people living in poverty or who are homeless on the streets. It has been estimated that globally 50,000 people die every day from being malnourished. In the United States an estimated twenty million people suffer from hunger on a regular basis. Around the world a billion people do not get enough to eat. In the United States many of the malnourished suffer from chronic diseases or are the elderly. The lack of sufficient nutrition in these cases is due more to the lack of adequate self-care or to the absence of adequate care giving. Human health needs are such that human nutrition as a part of general nutrition science can be defined as meeting human health needs as part of the total life activity of human beings. Since everyone is different and has different nutritional needs for health at different times nutrition scientists have place those needs into four categories. The categories are age group needs, health status, stress factors, and basic human needs. Each age group has its own needs as they move through the lifecycle from birth, growth, maturity, and old age. Developing standards for the food requirements of people in different countries, especially in developed countries, began in about 1900. The guides for food and nutrition requirements were conditioned by the social, political and economic events of the times. They were also influenced by the rapid advances made in nutrition science, health science and the life sciences.
1258 Nutrition Among the factors inspiring advances in nutritional sciences and food guides were the great social events of the 20th century, wars, famines, economic depressions, and emergencies. In the past much of the focus in developed countries was on inadequate diets, today the focus has shifted to meeting the needs of the chronically ill and the dangers of excessive eating. Today there are three general types of nutritional guides in use. They are those that set nutritional standards, food guides, and dietary guidelines. The Recommended Dietary Allowance (RDA) is one form of nutrition guide. They have been developed in most of the developed countries of the world as standards for every age and sex category. Usually they serve as guidelines for maintaining the health of population groups. They are group nutritional guides and not tailored for specific individuals. They are therefore highly variable and general in nature. They do not address the individual health needs of eaters nor do they set clinical needs. Instead they often serve as a reference base for nutritional science research to meet the needs of changing population groups. In the United States nutrition and energy standards are called the Recommended Dietary Allowances (RDAs). Other countries have similar standards which have different names; however, there is only a little difference between them and the nutritional purposes. RDAs were first developed during World War II in the United States. In 1941, prior to American entry into the war a national nutritional conference began work on standards. In 1943 a report was issued that gave nutrition workers a guide for planning and obtaining food needs for military operations and for the relief needs of liberated civilians. Following World War II, research on the RDAs continued with the publication of updated guides through today. The word has since been assigned to the Food and Nutrition Board of the National Research Council. The Board is a part of the Institute of Medicine of the National Institutes of Health. Most of its funding comes from the United States government. British, Canadian, and New Zealand standards are similar to those in the United States. In less developed countries are affected by the lower quality of food stocks. The standards followed are those of
Food supplies energy and nutrients for building and maintaining the body, but it is also eaten as a source of pleasure.
the Food and Agriculture Organization (FAO) of the World Health Organization (WHO). Food guides are used to interpret and apply sound nutrient standards in practical food guides that can help with the planning of individuals and families. The Basic Four Food Groups Guides and the Food Exchange Lists Guide are used to aid population groups that need simplified instructions. The Basic Four Food Groups has been used for decades and it was issued by the U. S. Department of Agriculture (USDA). The guide reflects the USDA’s concern for disposal of surplus commodities. Until 1958 the three groups of fruits and vegetables were combined into a single group. The Exchange Lists Food Guide
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was introduced in 1950 by the American Diabetes Association and the American Dietetic Association. In order to manage meal planning diets for people with diabetes. It was based on the unique concepts of food exchange groups. The ability to exchange between food groups and basic planned meals gives a person greater freedom over their diet. In 1986 the food exchange lists underwent significant revisions in order to reflect the advances in nutrition and health sciences. The six basic food groups were completely reorganized and three exchange lists were added. These included free foods and seasonings, combination foods, and foods such as a slice of birthday cake which are eaten only occasionally. The new guide was a powerful educational tool for diabetics and for others managing chronic health issues and nutrition needs. Since the end of the 20th century more health promotion guides have been published. These guides represent the growing concern of health professionals, consumer groups, and the government. Three health promotion guides that have been issued are the U. S. Dietary Guidelines, the Dietary Guidelines for Heart Disease Prevention, and the Dietary Guidelines for Cancer Prevention. Clinical applications include guidelines that include eating a variety of foods, maintaining ideal weight, avoiding fats (especially saturated fats), eating enough fiber, avoiding sugar and salt, consuming alcohol in moderation. The Guidelines for Cancer Prevention first published in 1985 set guideline for the consumption of fats, fiber, Vitamins A and C, vegetables, preserved foods, and alcohol. The guides are used for diet education. SEE ALSO: Dieting; Nutritionist Bibliography. Katharine R. Curry and Amy Jaffe, Nu-
trition Counseling and Communication Skills (Elsevier Health Sciences, 1997); Sareen S. Gropper, Jack L. Smith, and James L. Groff, Advanced Nutrition and Human Metabolism (Cole, 2004); Joseph Lawrence Gardner and Robert Bahr, Eat Better, Live Better: A Commonsense Guide to Nutrition and Good Health (Reader’s Digest, 1982); Marion Nestle, What to Eat (North Point Press, 2006); Isadore Rosenfeld, Doctor, What Should I Eat? : Nutrition Prescriptions for Ailments in which Diet can Really Make a Difference (Random House, 1995); W H Sebrell and James
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J Haggerty, Food and Nutrition (Time Inc., 1967); Lori A. Smolin and Mary B. Grosvenor, Nutrition: Science and Applications (John Wiley & Sons, Incorporated, 2007); Sue Rodwell Williams, Essentials of Nutrition and Diet Therapy (Times Mirror/Mosby College Publishing, 2000); Bonnie S. Worthington-Roberts and Sue Rodwell Williams, Nutrition throughout the Life Cycle (McGraw-Hill, 1997). Andrew J. Waskey Dalton State College
Nutritionist A nutritionist is a person who advises other people on dietary matters relating to their health and well-being. While dieticians have formal accredited tertiary qualifications, nutritionists require no formal training, and as a result, Dieticians tend to use that term in their professional life, with the term nutritionist often being used by unqualified practitioners who can range from healthcare professionals to people who advise on nutrition at a health food store. There are a large number of nutritionists who write for newspapers and magazines, advising on diets, with others writing nutritional books which vary in content from those that offer detailed and scientifically tested diets to those that have been found to be unhelpful at best. To try to go some way in regulating nutritionists, the Nutrition Society operates in the United Kingdom, although registration is voluntary as the occupational term nutritionist is not protected. The Society was established in 1941 with the task “to advance the scientific study of nutrition and its application to the maintenance of human and animal health.” It also produces four scientific journals (British Journal of Nutrition, Nutrition Research Reviews, Proceedings of the Nutrition Society, and Public Health Nutrition), which are published by Cambridge University Press. In the United States, the American Society for Nutrition has more than 3,500 members. It publishes The Journal of Nutrition and also the American Journal of Clinical Nutrition from its headquarters in Bethesda, Maryland. Important nutritionists in recent years include Dr. Robert Coleman Atkins who was a cardiologist and
1260 Nutritionist wrote seven books starting with the Dr. Atkins’ Diet Revolution (1972) in which he advocated that people wishing to lose weight should eat large amounts of fat and protein to lessen their intake of carbohydrates. Others have appeared on television, in newspapers, and magazines, and have published books, some of which have valuable information, with others being marginal in terms of their usefulness.
SEE ALSO: Nutrition. BIBLIOGRAPHY. Mary Barasi, Human Nutrition: A Health
Perspective (Oxford University Press, 2003); Eleanor Noss Whitney and Sharon Rady Rolfes, Understanding Nutrition (West, 2001); Royal College of Nutrition, www.nutsog. org.uk (cited July 2007). Justin Corfield Geelong Grammar School, Australia
O Obesity Obesity is a medical condition characterized by excess adipose, or fat, tissue sufficient to cause several adverse health effects. With modernization have come increased access to food supplies and decreased necessity for physical activity in daily life. The resulting imbalance in caloric intake and expenditure has caused a dramatic increase in the rates of obesity, in both developed and developing countries. This new global epidemic brings with it an increased risk of many serious adverse health consequences, including heart disease and type 2 diabetes mellitus (T2DM). Definition Obesity is most commonly defined in terms of the body mass index (BMI), calculated by dividing an individual’s body weight in kilograms by the square of his or her height in meters. Obesity is generally defined by a BMI of 30 kg/m2 or greater. The American Gastroenterological Association uses the following BMI values to categorize a person’s adiposity: overweight (BMI 25.0–29.9 kg/m2), class I obesity (BMI 30.0–34.9 kg/m2), class II obesity (BMI 35.0–39.9 kg/m2), and extreme or class III obesity (BMI >40 kg/m2). A normal BMI falls in the range
of 18.5–24.9 kg/m2, while a BMI less than 18.5 kg/ m2 is considered to be underweight. Absolute BMI cutoffs are not used in children aged 2 to 19. Rather, a child is considered to be overweight if his or her BMI is greater than the 95th percentile of BMI for age and gender. Similarly, he or she is considered to be obese if over the 99th percentile. It is now recognized that the percentage of body weight that is adipose tissue and the distribution of this adipose tissue are more important for increased disease risk than the absolute value of BMI. A central (“apple-shaped”) distribution of adipose tissue inside the abdominal cavity is associated with a higher risk of diabetes than superficial (“pear-shaped”) adiposity around the hips and thighs. For this reason, a simple waist circumference or waist-to-hip ratio is used in some assessments of risk instead of BMI. Moreover, BMI can be misleading in some circumstances. For example, a lean person with increased muscle mass and little adiposity might appear to have a BMI in the obese range, despite having a low body fat percentage. Additionally, a certain BMI value may imply different risks in different ethnic groups. In some East Asian populations, a BMI of about 27 kg/m2 corresponds to the same degree of adiposity as a BMI of 30 kg/ m2 in European populations. Nonetheless, BMI has been shown to have good correlation with body fat
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1262 Obesity percentage in most cases and is still useful for epidemiologic studies. Bioelectrical impedance, in which body fat percentage is determined by passing a small electric current through the body, is also commonly used. More expensive methods of determining adiposity include computed tomography (CT) and magnetic resonance imaging (MRI). Epidemiology The recent trends in obesity are appropriately described as a global epidemic centered predominantly but not exclusively in more developed countries. More than 300 million people were obese in the year 2000. The most recent study from the U.S. Centers for Disease Control and Prevention (CDC) found that 17.1 percent of U.S. children and adolescents aged 2 to 19 were overweight and 32.2 percent of U.S. adults were obese. About two-thirds of the American adult population is obese or overweight; that is, the minority of the population has a healthy weight. The prevalence of obesity remained relatively stable in the United States from 1960 to 1980 and then experienced a sharp increase of 100 percent from 1976 to 1980 and 1999 to 2002 in all ages and ethnic groups—a rise of 15 percent of the population in the first survey to nearly 33 percent in the following one. Europe has similarly experienced an increase in prevalence over the last 10 years, most pronounced in Eastern Europe, certain Scandinavian countries, and the United Kingdom, where the rate of obesity was as high as 24 percent in women in 2005. In developed countries, BMI tends to vary inversely with socioeconomic status, but this relationship reverses in the developing countries of Africa, where the prevalence of obesity is highest in urban women with higher educational attainment. In general, women have higher rates of obesity than men, and the countrywide prevalence of obesity among women in almost all countries in Central and South America, North Africa, and the Middle East exceeds 30 percent. Although rates of overweight and obesity are increasing in East Asia, they remain remarkably low, being about 2.5 percent in Chinese women in 2005. Urban Indian women, on the other hand, have attained a prevalence of greater than 16 percent. Polynesia has the highest prevalence of obesity worldwide, reaching 80 percent among women in countries such as Nauru and Tonga.
Etiology The above epidemiology of obesity gives evidence for the etiologic factors contributing to this epidemic. Much of the ethnic variation in obesity is due to genetic differences. It may come as a surprise that genetics may account for between 50 and 90 percent of a person’s BMI, as shown by family, twin, and adoption studies. Researchers have identified a few single-gene mutations that result in obesity, especially of childhood onset, but these account for a small minority of obesity cases. It is more likely that the genetic foundation of obesity results from a combination of mutations in several genes, each of which contributes a small amount to an individual’s overall risk of obesity. Some of these susceptibility genes have been identified, including mutations of the β3-adrenergic receptor and peroxisome proliferators-activated receptor γ (PPARγ). This genetic predisposition does not, however, explain the recent rapid increase in the prevalence of obesity. Neither does it explain the observation that immigrant Japanese and Mexican populations acquire American rates of obesity not long after arrival to their new country. Moreover, within relatively genetically homogenous populations, there remain significant differences in BMI by environmental influences such as diet, physical activity, education, and urban or rural residence. Thus, like many multifactorial diseases, obesity is believed to result from a complex interaction of environmental factors and genetic predisposition. In evolutionary terms, the genetic predisposition to readily accumulate adipose tissue for energy storage conferred a survival advantage when food became scarce. This ability para-
Obesity is a medical condition characterized by excess adipose, or fat, tissue sufficient to cause several adverse health effects.
doxically poses a health threat now that calorie-dense food is overabundant in many parts of the world. The environmental determinants of obesity center around energy balance, the difference between the numbers of kilocalories consumed and expended. The current obesity epidemic shows that the world population is increasingly maintaining a positive energy balance, in which the energy consumed in food exceeds that expended by the body. Energy expenditure consists of the energy required to maintain a basal rate of metabolism (typically 50–80 percent), the energy required to digest food (10 percent), and the energy required for physical activity, the only modifiable component of energy expenditure. People normally gain weight as they age. Epidemiologic studies have shown that increased physical activity is associated with a lower prevalence of obesity but does not prevent general weight gain over the life span. Still, the age-associated weight gains are less than those in sedentary individuals. Energy expenditure from physical activity has decreased over recent decades, and food consumption has not similarly decreased to match the resulting lower energy needs. On the other side of the energy balance equation, dietary consumption of energy significantly determines the risk of obesity. Increased daily caloric consumption increases one’s risk for obesity. The density of foods may be an important determinant of caloric consumption, since people tend to consume more total kilocalories when eating more energy-dense foods, like those high in fat. Low-fat diets, such as the consumption of only 20 percent of calories come from fat, results in better weight maintenance than higher-fat diets. Certainly, the absolute amount of calories consumed also determines one’s risk of obesity. Although not a demonstration of causality, the rise in obesity has paralleled the increase in the portion sizes of foods served both in the United States and now increasingly in other countries. Behavioral studies have shown that people tend to overeat when presented with larger food portions. Moreover, a greater percentage of meals are consumed outside of the home, where eaters have less precise control over the energy content of their meals. An individual’s dietary and physical activity habits are in large part products of his or her sociocultural environment, and adherence to lifestyle habits necessary for weight maintenance requires cognitive control in the face of an environment that promotes overconsump-
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tion and physical inactivity. The sociocultural milieu that may influence an individual’s risk of obesity includes role modeling from parents and other influential people and the availability of nutritional foods and opportunities for safe physical activity. Economic circumstances dictate food affordability, and often highfat energy-dense food is more affordable than healthier options. In short, while energy balance is most proximally determined by a person’s energy consumption and expenditure, these processes interact with complex sociocultural determinants of the lifestyle choices available for the person to make. Adverse Health Effects Many adverse health consequences are associated with obesity, including cardiovascular disease and certain cancers. Obesity and probably overweight both increase the risk of all-cause mortality, although underweight does, too. Obesity is expensive for the American healthcare system, its adverse health effects costing around $100 billion or 9 percent of the nation’s health expenditure. Diabetes, with its serious complications including heart and kidney disease, is perhaps the most serious obesity-related condition. Concurrent with the global obesity epidemic is an increase in the prevalence of type 2 diabetes mellitus (T2DM), an endocrine disease characterized by high blood sugar levels (hyperglycemia) that can damage many organs. The risk of diabetes and impaired glucose intolerance, a pre-diabetic state, increases with greater body weight, specifically fat deposit in the central abdomen. While the risk of diabetes increases with body fat in all populations, the risk of diabetes increases at lower values of BMI for certain ethnic groups, including Indians and East Asians. Some experts have proposed using lower BMI cutoffs to define overweight and obesity in these populations to better reflect this increased risk. By pathways that are not fully understood, increased body fat is associated with resistance to insulin, a hormone important for the body’s utilization of energy in the form of the simple sugar glucose. Prolonged hyperglycemia over years results in the adverse health consequences of diabetes, which are categorized as microvascular or macrovascular, according to the size of the blood vessels affected. The microvascular complications of diabetes include eye disease (retinopathy), kidney
1264 Obesity disease (nephropathy), and nerve disease (neuropathy). Diabetes is the top cause of blindness in adults in developed countries and of end-stage renal disease worldwide. The macrovascular complications of diabetes include coronary artery disease and strokes, leading causes of mortality worldwide. Indeed, diabetes is considered to be a “risk equivalent” for coronary artery disease; that is, a diabetic is as likely to have a heart attack within 10 years as someone who has already had a heart attack. The nerve and vascular damage of diabetes also make it the leading cause of leg amputations in the United States. Given the close relationship between obesity and type 2 diabetes, some use the informal term diabesity to describe these often coexisting conditions. Even before an obese person meets the specific diagnostic criteria of diabetes, his or her obesity confers an increased risk of cardiovascular disease. Increased body weight tends to be associated with other known risk factors for cardiovascular disease, including changes in blood pressure and cholesterol levels. Obesity and insulin resistance are associated with higher serum triglycerides and lower high-density lipoprotein (HDL or “good”) cholesterol levels. Blood pressure also tends to increase with greater body weight. This clustering of risk factors has come to be known as the metabolic syndrome, although the definition of this condition varies. In 2005, the International Diabetes Foundation (IDF) generated a consensus definition of the metabolic syndrome that requires the presence of central obesity (with different cutoffs by ethnic group) plus two of the following four conditions: triglyceride level ≥150 mg/ dL, HDL cholesterol <40 mg/dL in men or <50 mg/dL in women, blood pressure ≥130/85, and fasting plasma glucose ≥100 mg/dL. People meeting the definition of the metabolic syndrome have twice the risk of heart attack, stroke, and death from all causes. Given that heart disease is the top cause of mortality in most countries, reducing the prevalence of the metabolic syndrome through prevention or treatment of its components would bring significant public health improvement. Cancer is the second leading cause of death in the United States, and certain cancers have been associated with obesity. The incidence of cancer overall in developed countries increases by about 30 percent in obese individuals, and cancer mortality is higher in the obese compared to normal-weight individuals with
cancer. Calle estimated in 2003 that 14 percent and 20 percent of the cancer cases in American men and women, respectively, could be prevented with weight maintenance between a BMI of 18.5 and 24.9 kg/m2. The risk of breast and uterine cancers increases with BMI, likely due to the higher estrogen levels associated with excess fat tissue. Perhaps due to increasing levels of insulin-like growth factor 1 (IGF-1), the risk of colorectal cancer increases with BMI in men, and the mortality due to colon cancer increases with BMI in both men and women. Obesity also increases the risk of kidney and esophagus cancers, leukemia, nonHodgkin lymphoma, and multiple myeloma. Obesity is associated with a number of other health consequences. Because of excess neck thickness, obesity also causes obstructive sleep apnea (OSA), a condition in which a person stops breathing for short periods while sleeping. OSA increases daytime fatigue and the risk of cardiopulmonary disease. OSA can be treated with weight loss and by using a continuous positive airway pressure (CPAP) machine, which keeps the airway open during sleep. Carrying excess body weight puts a lot of stress on the hips and knees, causing osteoarthritis in these joints. Obese individuals are generally more likely to be depressed than normal-weight individuals, although the relationship between these two conditions is complex and not fully understood. It is clear that obese individuals suffer discrimination and ridicule, despite their rising numbers. Other adverse consequences of obesity include blood clots, gall stones, gout, gastroesophageal reflux or heartburn, and infertility in women due to polycystic ovary syndrome. Public Health Interventions Most of the public health interventions for the prevention of obesity have appropriately targeted children, most often through school-based initiatives. These studies have included nutrition or physical activity interventions or a combination of both, and some have incorporated education for the entire family. To date, the results of such school-based interventions have been disappointing, showing no change in the BMI of the schoolchildren despite improvement in nutrition and physical activity habits. These negative results underline the difficulty of overcoming what is called the “obesogenic environment,” where calorie-rich foods are readily accessible and physical inactivity is facilitated. Environmen-
tal interventions may, therefore, prove useful in the fight against obesity. The built environment, with its suburban sprawl that is scaled more for automobiles than for pedestrian traffic, discourages the incorporation of physical activity into daily living. City planners and architects are increasingly being asked to design neighborhoods or buildings that encourage physical activity. Such features may include aesthetically pleasing staircases more prominently located than elevators and mixed-use city blocks in which people live within walking distance from where they work and shop. For adults, worksite-based employer-sponsored nutrition education and physical activity training has had some success in achieving modest weight loss. Public health law, which has been used to improve vehicle safety and vaccination and smoking rates, is a potential frontier for obesity intervention. In the United States, legislation at the state and federal levels has sought to limit the advertising of unhealthy foods to children and improve the quality of school lunches. Some states tax unhealthy foods such as candy and soft drinks. However, there is little evidence that such legislation results in a lower mean BMI in children. Screening and Treatment The U.S. Preventative Services Task Force recommends that physicians screen all patients for obesity by measuring their height and weight. Assessment of other risk factors such as high blood pressure, high LDL (“bad”) cholesterol, smoking, and diabetes also determine how aggressively a physician should encourage weight loss. In general, weight loss should be encouraged if a person’s BMI is ≥30 kg/m2 or ≥25 kg/m2 in association with at least two risk factors. Weight loss is a $50 billion industry in the United States, but in its simplest form need only consist of lower caloric intake and increased physical activity. For improved health, a 5 to 10 percent weight loss is a realistic goal and significantly lowers blood pressure, cholesterol, and blood glucose levels. Such weight loss can most safely be accomplished one to two pounds per week. More drastic weight loss may require medical monitoring and, being less sustainable than gradual weight loss, often has the same long-term results. Decreased caloric intake in general is more effective for weight loss, while increased physical activity works best in weight maintenance. One
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pound of fat equals about 3,500 kilocalories (simply called “calories” on nutrition labels), and thus one to two pounds per week can be lost by decreasing intake by 500 to 1,000 kilocalories a day. When consuming fewer kilocalories, one should be careful to maintain an adequate intake of low-fat dairy products and fiber-rich fruits, vegetables, and whole grains. Some diets reduce caloric intake by limiting the amount of carbohydrates a person consumes. Weight loss can be achieved with such diets, but they are difficult to maintain and may encourage higher consumption of saturated fats and cholesterol. Meal replacement diets, in which liquid supplements replace one or two meals per day, have proven helpful in reducing daily caloric intake and maintaining weight loss. Regarding the expenditure side of the energy balance equation, the National Academies Institute of Medicine recommends that adults and children engage in a total of 60 minutes of moderately intense physical activity each day, including brisk walking and taking the stairs. Acute increases in physical activity can produce significant weight loss but have poor long-term maintenance of these losses. All dietary and physical activity changes should be moderate and realistic to ensure sustainability and long-term weight maintenance. People trying to lose weight should weigh themselves a couple times a week to assess progress. Lifestyle changes are difficult to maintain, but the use of behavioral modification techniques can improve the success of such attempts. Behavioral modification seeks to reinforce the desired behaviors and eliminate undesired ones. Although their efficacy remains largely unstudied, numerous programs exist that encourage participants to set goals and to meet them by identifying their triggers for overeating and physical activity and replacing them with reminders to practice better habits. Behavioral modification also analyzes and addresses the beliefs and emotional responses underlying eating and activity behaviors. Such programs also provide emotional support to people struggling with obesity. The decision to begin weight loss medication or undergo bariatric surgery requires extensive discussion with a physician and depends on the severity of a person’s obesity, associated risk factors, and complications of obesity. Weight loss drugs include orlistat (Xenical®) and sibutramine (Meridia®) and can achieve modest weight loss comparable to that achievable with dietary
1266 Obsessive-Compulsive Disorder changes. While they do not create greater weight loss beyond six months of use, they are effective at maintaining weight loss for at least two years. These drugs are not without side effects: orlistat may cause soft stools and fecal leakage, while sibutramine increases heart rate and blood pressure. Bariatric surgery is performed in people with a BMI ≥40 kg/m2 or a BMI ≥35 kg/m2 in the presence of other health conditions. Although several types of surgery exist, all modify the gastrointestinal tract in some way to decrease caloric intake. Some procedures make the stomach smaller and less able to accommodate large food intake, while others reroute the digestive tract to bypass a certain length of intestine, such that more food passes through unabsorbed. Weight loss can range from 10 to 30 percent, is maintained, and accompanies a decrease in risk factors like high blood pressure and cholesterol. Still, the overall risk of death is 1 percent after bariatric surgery, and up to 20 percent of patients experience complications such as infections or additional surgeries.
Obsessive-Compulsive Disorder
SEE ALSO: Diabetes; Diabetes Type II; Diabetic Eye Prob-
Diagnostic Criteria The Diagnostic and Statistical Manual of Mental Disorders, 4th edition (DSM-IV), published by the American Psychiatric Association, establishes five diagnostic criteria used by clinicians in diagnosing obsessive-compulsive disorder. First, the individual must have either obsessions or compulsions described as follows: obsessions are recurrent, persistent thoughts that are intrusive and cause marked anxiety. These thoughts and images are not merely excessive worrying about “real” problems and originate from the individual. The individual makes an attempt to suppress the thoughts and images with another action. Compulsions are defined as repetitive behaviors or mental acts that an individual feels compelled to perform in response to an obsession even though the acts are not connected in a clear way to the obsession. Second, the person comes to the realization at some point in the course of the disorder that his or her behaviors are excessive. Third, the obsessions and compulsions become time consuming and significantly disrupt routine activities. Finally, the obsessive-compulsive behavior is not limited to another Axis I diagnosis if present nor is the behavior directly linked to the effects of another substance (e.g., drugs or medication).
lems; Diabetic Foot; Diabetic Kidney Problems; Diabetic Nerve Problems. BIBLIOGRAPHY. A. H. Barnett and S. Kumar, eds., Obesity
and Diabetes (Wiley, 2004); E. E. Calle, et al., “Overweight, Obesity, and Mortality from Cancer in a Prospectively Studied Cohort of U.S. Adults,” New England Journal of Medicine (v. 348, 2003); S. Klein, T. Wadden, and H. J. Sugerman, “AGA Technical Review on Obesity,” Gastroenterology (v.123/3, 2002); Z. Li, et al., “Meta-Analysis: Pharmacologic Treatment of Obesity,” Annals of Internal Medicine (v.142/7, 2005); M. A. Maggard, et al., “Meta-Analysis: Surgical Treatment of Obesity,” Annals of Internal Medicine (v.142/7, 2005); C. S. Mantzoros, ed., Obesity and Diabetes (Humana Press, 2006); M. M. Mello, D. M. Studdert, and T. A. Brennan, “Obesity—The New Frontier of Public Health Law,” New England Journal of Medicine (v.354/24, 2006); C. L. Ogden, et al., “Prevalence of Overweight and Obesity in the United States, 1999–2004,” Journal of the American Medical Association (v.295/13, 2006); C. D. Summerbell, et al., “Interventions for Preventing Obesity in Children,” Cochrane Database of Systematic Reviews (v.3, 2005). Jason Vassy Washington University in St. Louis
Obsessive-compulsive disorder is a chronic, disabling anxiety disorder characterized by intrusive, persistent thoughts and repetitive behaviors. Obsessions may include recurrent thoughts, images, or impulses that cause distress or anxiety such as aggressive thoughts, fears of germs or dirt, fears of social embarrassment, or fears that others may be in danger. Although healthy people exhibit compulsive behavior (e.g., checking to make sure the iron is turned off ), individuals with obsessive-compulsive disorder have compulsive rituals that are performed to neutralize or combat these fears; these compulsions are not pleasurable, often end up controlling the individual, and may interfere with his or her daily life. Notwithstanding the emotional burden to the individual and his or her family, total lifetime indirect costs of obsessive-compulsive disorder are estimated at $40 billion.
Epidemiology, Cause, and Clinical Features Obsessive-compulsive disorder affects over 2 million adult Americans and has a lifetime prevalence of 2 to 3 percent in the United States. These rates are consistent with those in Europe, Africa, Canada, and the Middle East, while estimated rates in Asian countries are slightly lower. Although obsessive-compulsive disorder is a lifetime illness, its prevalence in young adults is twice that seen in older adults. Obsessive-compulsive disorder often appears in childhood, adolescence, or young adulthood and may be accompanied by other anxiety disorders such as eating disorders. In fact, disorders whose features are shared with obsessivecompulsive disorder (e.g., somatoform disorders, neurologic disorders, eating disorders, and impulse control disorders) have been categorized as “obsessive-compulsive spectrum disorders.” Obsessive-compulsive disorder affects men and women in different proportions, depending on the age of onset. Of those individuals whose onset is in childhood or early adolescence, males are disproportionately affected. Women have a slightly higher prevalence of obsessive-compulsive disorder in the adult population. Specific obsessions that occur commonly in obsessive-compulsive disorder include contamination fears and pathological doubt (irrational fears that something is wrong). The need for symmetry, fears of endangerment to self or to others, and sexual concerns occur less often. Individuals with obsessive-compulsive disorder experience a significant drop in the quality of their lives attributed to the acute shame, distress, and the amount of time devoted to acting out their compulsive behaviors. Social, familial, and professional relationships are impaired as individuals with obsessive-compulsive disorder may miss appointments, meetings, and scheduled gatherings due to their rituals. Diagnosing obsessive-compulsive disorder may be difficult due to a reluctance to seek treatment and thereby disclose their symptoms out of fear that they will be considered “crazy,” thus putting the onus on physicians to screen actively for obsessive-compulsive disorder in their patients. Examples of screening questions may include “Are there certain thoughts that go through your mind over and over that you
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cannot get rid of?” or “Are there behaviors or habits that you feel compelled to repeat?” Over the years, major etiologic theories of obsessive-compulsive disorder have included those that are described as psychoanalytic, cognitive, traumatic, and genetic. It is no longer thought that obsessive-compulsive disorder arises from psychic trauma or from psychoanalytic origin. The observation that obsessive-compulsive disorder occurs with higher frequency in first-degree family members as compared to the general population has sparked interest in research in genetic models for this disorder. Obsessive-compulsive disorder has been linked to a gene responsible for the tics and obsessive-compulsive disorder behavior found in Tourette’s syndrome. Although causality has yet to be established, imaging studies also have implicated the prefrontal cortex, cingulate gyrus, and basal ganglia in this disorder, and the neurotransmitter serotonin is thought to play a role in the pathogenesis as well. Outcomes and Treatment In one long-term study of individuals with obsessive-compulsive disorder, only one-fifth of the study participants experienced a full remittance of their disorder. However, two-thirds described some improvement 10 years postdiagnosis. Treatment of individuals with obsessive-compulsive disorder can be challenging due to the frequent relapse rate, but both psychotherapy (behavioral therapy) and drug therapy may be useful forms of treatment. Behavioral therapy for obsessive-compulsive disorder includes both exposure and response prevention, and cognitive therapy. This is built around the premise that anxiety will dissipate with increased contact with the triggering stimulus. However, chronic exposure is not enough; the compulsions will remain if not specifically addressed. Therefore, the clinician guides the individual through experiencing the aversive condition while refraining from performing the compulsion. Pharmacological treatment is recommended for most individuals with obsessive-compulsive disorder, and among the preferential serotonergic reuptake inhibitors which include fluoxetine (also known as Prozac®), clomipramine has been the primary therapy for years. However, its side effects have been severe: weight gain, drowsiness, anticholinergic effects. Later
1268 Obstetric Fistula research describes other selective serotonin reuptake inhibitors (SSRIs) as superiorly effective to clomipramine, although treated individuals frequently complain of unwanted sexual side effects a few weeks into pharmacotherapy. There is no cure for obsessivecompulsive disorder. Current Research Pregnant and postpartum women appear to be at particular risk of developing obsessive-compulsive disorder. Limited research reveals that the obsessive thoughts these women have pertain to harming the baby, fears of sexually abusing the baby, and again, contamination fears. With exception to the last, acting on these obsessions has been rare; nevertheless, this finding warrants attention. In response to fears about contamination, postpartum women may avoid changing the baby, allowing it to crawl on floors, or compulsively washing the baby’s bottles. If left untreated, obsessive-compulsive disorder in pregnant women may worsen after she gives birth. SEE ALSO: Mental Health; Postpartum Depression;
Psychiatry.
BIBLIOGRAPHY. Paul Ciechanowski and Wayne Katon,
“Overview of Obsessive-Compulsive Disorder,” UpToDate (UpToDate, 2007); E. Hollander et al., “Obsessive-Compulsive and Spectrum Disorders: Overview and Quality of Life Issues,” Journal of Clinical Psychiatry (v.57, 1996); National Institute of Mental Health, “Obsessive-Compulsive Disorder,” http://www.nimh.nih.gov/healthinformation/ ocdmenu.cfm (cited July 2007); G. Skoog and I. Skoog, “A 40-Year Follow-Up of Patients with Obsessive-Compulsive Disorder,” Archives of General Psychiatry (v.56, 1999). Lareina Nadine La Flair, MPH Harvard University
Obstetric Fistula Obstetric fistula refers to an abnormal opening between adjacent structures in the pelvis, resulting from the compression of soft tissues by the baby’s head during arrested labor, particularly during the second or “pushing” stage. Obstetric fistula is almost unheard of
in the developed world, because arrested descent of the fetal head is commonly relieved by performing a widely available surgery, Caesarean section. Some experts have estimated that over 3 million women suffer from obstetric fistula. Obstetric fistula is a complicated global health problem in terms of its consequences, risk factors, treatment, and prevention. Types of obstetric fistula include vesicovaginal fistula (between the bladder and the vagina) and rectovaginal fistula (between the rectum and the vagina) among others. It is also possible for a woman to develop a combination of several types of fistula and to experience related injury to muscles, nerves, and/or skin. However, it is injury to social relationships that may carry the greatest risk of harm to women globally. Women with severe urinary and/or fecal incontinence and the related odor resulting from fistulae commonly struggle with problems such as rejection by family members, homelessness, social isolation, depression, divorce, poverty, malnutrition, and even early death. Some cultures believe that a difficult labor and delivery is a divine punishment for immoral behavior, making it difficult for women with fistulae to ask for and receive help. Several different factors may put women at risk for the development of fistulae. Cultural practices supporting the early marriage of girl children contribute to higher rates of fistulae, as do malnutrition and low socioeconomic status of women in the developing world. Areas where skilled labor attendants are lacking and obstetric services may be limited or remote tend to have higher rates as well. Surgical repair may be costly and difficult, depending on the extent of damage to body tissues. Even after fistula repair, many women still have some incontinence. The Addis Ababa Fistula Hospital is a large specialty center in Africa devoted to care for fistula patients, and is considered a model for this type of institution. Experts believe that prevention of obstetric fistulae will require the attention of public and private partners to this complex problem rooted in gender inequality, economic disadvantage, and inadequate healthcare infrastructure in the developing world. SEE ALSO: Incontinence; Obstetrics; Pregnancy. BIBLIOGRAPHY. L. Lewis Wall, “Obstetric Vesicovaginal
Fistula as an International Public Health Problem,” Lancet
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(v.368, 2006); Steven G. Gable, Jennifer R. Niebyl, and Joe Leigh Simpson, eds., Obstetrics: Normal and Problem Pregnancies (Churchill Livingstone, 2002). Lisa Noguchi Pittsburgh Medical Center
Obstetrician/Gynecologist An obstetrician is a medical doctor who is involved in the care of a woman and her offspring during pregnancy, childbirth, and the period just after birth. Historically, most people practicing obstetrics were female midwives, with European male physicians tending to become involved from the 17th century onward. Most obstetricians are also gynecologists, who specialize in medical problems affecting women, usually related to reproductive health and genital problems. There are a number of medical bodies representing obstetricians and gynecologists, the most famous being the Royal College of Obstetricians and Gynaecologists, founded in 1929, in Britain. The college publishes the British Journal of Obstetrics and Gynaecology each month, and The Obstetrician and the Gynaecologist each quarter. There have been gynecologists since ancient times, with descriptions of them in classical texts. However, the main modern interest comes from the publication of an encyclopedia of gynecology written by Caspar Wolf of Zurich, Switzerland, in 1566. The American surgeon James Marion Sims was also important in the development of research into operative gynecology. Famous obstetricians include Scotsman William Smellie who taught midwifery on a scientific basis; William Hunter who removed obstetrics from the hands of midwives to establish it as an accepted branch of mainstream medicine; Sir James Young, 1st Baronet Simpson, the Scottish obstetrician who pioneered the use of chloroform in obstetrics; Hungarian Ignaz Philipp Semmelweis, who discovered the cause of puerperal fever; the American Vincent Freda, who shared the Albert Lasker Award for clinical research for his work in developing Rhogam, a vaccine that has helped many Rh-positive infants; and Patrick Steptoe and Robert Edwards who pioneered in vitro fertilization.
Most obstetricians are also gynecologists, who specialize in medical problems affecting women, usually related to reproductive health.
SEE ALSO: Gynecology; Midwife; Obstetrics; Pregnancy;
Women’s Health (General).
BIBLIOGRAPHY. Steven G. Gable, Jennifer R. Niebyl, and
Joe Leigh Simpson, eds., Obstetrics: Normal and Problem Pregnancies (Churchill Livingstone, 2002); William F. Mengert, History of the American College of Obstetricians and Gynecologists 1950–1970 (American College of Obstetricians and Gynecologists, 1971); The Royal College of Obstetricians and Gynaecologists, London, http://rcog. org.uk (cited July 2007). Justin Corfield Geelong Grammar School
Obstetrics Each year, over half a million women die as a result of complications of pregnancy, childbirth and abortion. The vast majority of these deaths are preventable and occur in developing countries in contexts where women lack access to good quality, skilled and timely health care. Obstetrics is the surgical specialty involved with the care of women during pregnancy, childbirth, and the puerperium (the period shortly after birth). Most
1270 Obstetrics obstetricians are also gynecologists and look after women’s other health issues such as fertility problems, reproductive organ cancers, and termination of unwanted pregnancy in some settings. Obstetrics differs from other branches of medicine in that it deals with patients who are generally in good health. After all, pregnancy is not a pathological condition, but rather a natural process that most women will go through at some point in their lives. The majority of pregnancies proceed without complications and result in the safe delivery of a healthy infant. However, every woman has the potential to develop a life-threatening complication during pregnancy or childbirth that may require skilled care and, occasionally, surgical intervention. The role of the health professional during pregnancy and labor is therefore to prevent, recognize, and manage complications that might otherwise result in catastrophic outcomes for the woman and her baby. In many countries, both in the developed and developing world, the care of women during pregnancy and childbirth is shared among different health professionals and is not exclusively the domain of medically trained doctors. Midwives and specialist nurses are key providers of care to pregnant women in developed countries, while in many parts of the developing world, women deliver with the assistance of traditional birth attendants and family members. Maternal health reflects the overall quality of healthcare systems within a community: the facilities available, women’s ability to access these facilities, the status and role of women in society, and the background incidence of chronic disease and malnutrition. Maternal mortality is, however, difficult to measure and quantify, particularly where health infrastructures are weak and causes of deaths are poorly registered. Thus, global estimates of maternal mortality are often subject to wide margins of error and are broadly considered to underestimate the magnitude of the problem in developing countries. Maternal Mortality A maternal death is defined as the death of a woman while she is pregnant or within 42 days of termination of pregnancy from any cause related to or aggravated by the pregnancy or its management. Global data on maternal mortality show the greatest discrepancy between developed and developing countries than any
other demographic indicator: 99 percent of global maternal deaths occur in developing countries, and complications of pregnancy and childbirth are the leading causes of death, disease, and disability among women of childbearing age in poor countries. The most commonly used comparative measure of maternal mortality is the Maternal Mortality Ratio (MMR), which expresses the risk of death once a woman has become pregnant. Worldwide, this figure is estimated at 400 deaths per 100,000 live births, but it varies greatly by region: the average MMR in Africa is 830 deaths per 100,000, compared with 20 per 100,000 in developed countries. Nineteen out of the 20 countries with the highest MMRs are in sub-Saharan Africa. Measures of lifetime risk of maternal death, which take into account the total number of children women bear, show similar trends. The average woman in sub-Saharan Africa faces up to a 1-in16 lifetime risk of maternal death, compared with a global average of 1-in-74, a 1-in-92 risk in Asia and a 1-in-2,800 risk of maternal death for women in developed countries. The majority (between 50 and 70 percent) of maternal deaths occur in the period shortly after birth, a quarter occur during pregnancy, and between 11 and 17 percent of deaths occur during childbirth itself. The biggest direct cause of maternal death is hemorrhage before and after delivery. Other major causes include brain and kidney damage due to eclampsia (high blood pressure and convulsions during or after pregnancy), obstructed labor, and sepsis (blood poisoning due to infection). In addition, over 70,000 women die each year from complications of unsafe abortion. Thousands more die of indirect causes: preexisting conditions that are exacerbated by pregnancy and delivery, such as human immunodeficiency virus (HIV)/AIDS, malaria, viral hepatitis, diarrhea, tetanus, heart disease, and sickle cell disease. Obstetric Fistula For each woman who loses her life as a result of complications in childbirth or pregnancy, approximately 30 others sustain severe and permanent injuries. However, because women in developing countries often do not seek medical treatment for obstetric and gynecological illnesses, global indicators of maternal trauma and ill-health are even sparser and more approximate than mortality data.
Obstetric fistula is one of the most devastating of the avoidable injuries that occur to women and girls during childbirth. A fistula is an abnormal opening between two body cavities, which can occur throughout the body, for a variety of reasons. The majority of obstetric fistulas in developing countries develop as a result of prolonged obstructed labor. Obstructed labor may be due to cephalo-pelvic disproportion (where the baby’s head is too large to pass through the mother’s pelvis), or to malpresentation (when the baby descends through the pelvis in an awkward position, with its face, arm, buttocks, or feet first). Whatever the cause, obstructed labor constitutes an obstetric emergency. The baby is unable to pass out of the mother’s body unaided, and treatment is almost always by Caesarean section. Lack of timely, skilled emergency obstetric care for women in obstructed labor inevitably leads to fetal death, and often to the death of the mother from hemorrhage, sepsis, or shock. Women who do survive are at risk of developing a fistula between the bladder and the vagina due to the prolonged pressure of the baby’s head against the soft tissues in the mother’s pelvis. They are left incontinent of urine and sometimes also of feces, unable to bear any more children, socially stigmatized, and emotionally traumatized. Fistulas do not heal naturally; they require expensive specialized surgery to repair the hole and restore continence. As a result, it is estimated that there are over 2 million women worldwide with obstetric fistula. All of these women live in developing countries, particularly in sub-Saharan Africa and southeast Asia. The persistence of obstetric fistula in these countries represents yet another example of the inequalities in access to skilled obstetric care for the world’s poorest and most disadvantaged women. Infant Health Lack of adequate obstetric care also has tragic consequences for the health and well-being of millions of babies born to poor women each year. Each year, over 3 million babies are stillborn, 4 million die within the first 28 days of life, and another 6 million infants do not live to see their fifth birthday. Neonatal and child mortality figures show similar geographical trends to maternal mortality data: 98 percent of neonatal deaths take place in developing countries, mainly in Africa and southeast Asia, whereas a neonatal death
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is a relatively rare occurrence in most of the developed world. An African woman has a 1 in 5 lifetime chance of losing a newborn baby, compared with a 1 in 125 risk in developed countries. For every baby who dies in the first four weeks of life, another 20 infants suffer birth injuries, asphyxia, infection, and complications associated with premature birth. These conditions can result in serious long-term consequences such as cerebral palsy, learning difficulties, cardiac damage, and other disabilities. New studies suggest that ensuring that women have access to skilled attendance at birth also results in improved neonatal and infant health. The Global Safe Motherhood Agenda Maternal health has been a long-neglected issue in the public health and policy arena. The International Safe Motherhood Conference, held in Nairobi, Kenya, in 1987, marked the beginning of the first global effort to curb the alarming rates of maternal death and illness in the developing world. A global collaborative partnership, the Safe Motherhood Initiative, made up of major donors, United Nations organizations, the World Health Organization, and various nongovernmental organizations, was born out of the Nairobi conference and has remained at the forefront of global maternal health campaigns. In the 1990s, safe motherhood programs became incorporated within a broader rights-based approach which advocated valuing women’s health and well-being as ends in and of themselves rather than means toward the ends of fertility reduction or child health. This new reproductive health paradigm was formally adopted in 1994 at the United Nations International Conference on Population and Development (ICPD) held in Cairo, Egypt. For the first time, governments from 179 countries publicly endorsed a Programme of Action that put reproductive and sexual health at the center of a human rights-based agenda for women’s health. The 1987 Safe Motherhood Conference set the goal of reducing global maternal mortality by half in a decade. Yet two decades and countless conferences, symposia, and workshops later, this primary objective is still far from being realized. Targets for reducing maternal mortality have repeatedly been set (and duly missed) as part of several major international development agendas. Most recently, Goal 5 of the Millennium Development Goals (MDGs) set at the
1272 Occupational Health United Nations’ Millennium Summit in 2000, states as its objective “to reduce by three-quarters, between 1990 and 2015, the maternal mortality ratio.” However, while some countries have made great progress toward meeting this goal, a recent World Bank study reveals that for the majority of countries in sub-Saharan Africa, conditions have worsened or stagnated since 1990. Most African nations are very unlikely to meet the MDG target. The countries that have succeeded in improving the health and well-being of mothers have largely been those that started off with relatively low levels of maternal mortality and morbidity. Countries that began with the highest burdens of maternal ill-health, such as in most of sub-Saharan Africa and southeast Asia, have made least progress toward meeting the MDGs. Thus, the disparities between rich and poor countries in crucial women’s health indicators have persisted and even increased despite unprecedented global efforts to improve maternal health for the world’s most disadvantaged women. Countries that have struggled to improve health indicators for mothers and newborns have often been unable to invest sufficiently into creating and maintaining the health infrastructures necessary to provide quality care, particularly in rural areas. Maternal and fetal deaths occur in settings where women are socially undervalued, health infrastructures are weak, access to skilled, timely obstetric care is lacking, and where women and communities lack financial resources to access what medical care is available. Humanitarian crises, widespread poverty, human immunodeficiency virus (HIV)/AIDS, civil conflict, and healthcare worker shortages have all contributed to worsening health outcomes across a broad spectrum of measures, not just maternal health. Most safe motherhood programs focus on the provision of timely emergency obstetric care and skilled attendance at delivery as central components of efforts to improve maternal health. For example, a number of programs supported by the United Nations Population Fund (UNFPA), which is one of the world’s largest sources of funding for reproductive health and population programs in developing countries, involve building and equipping clinics and referral centers, training physicians and midwives, and devising health sector reforms. The World Health Organization also focuses on the need to provide a “continuum of care”
for women, beginning at the time they become pregnant and extending to the early postpartum period. The goal of these programs is to ensure that every woman gives birth with professional, skilled care that is culturally acceptable and within close proximity to a health center capable of providing specialized emergency obstetric care. It is only by strengthening healthcare infrastructures and empowering women to recognize and advocate for their rights to reproductive and sexual health that we can begin to address the unacceptable frequency with which poor women suffer needlessly in the process of giving birth. SEE ALSO: Abortion; Adolescent Health; AIDS and Preg-
nancy; Neonatology; Pregnancy; Women’s Health (General). BIBLIOGRAPHY. Oona Campbell and Wendy Graham,
“Strategies for Reducing Maternal Mortality: Getting On with What Works,” Lancet (v.368, 2006); World Bank, World Development Report 1993: Investing in Health (World Bank, 1993); World Health Organization, Maternal Mortality in 2000: Estimates Developed by WHO, UNICEF and UNFPA (World Health Organization, 2000); World Health Organization, World Health Report 2005: Make Every Mother and Child Count (World Health Organization, 2005). Toyin Ajayi King’s College London
Occupational Health Occupational health was defined in 1950 by a working group of the International Labor Organization (ILO) and the World Health Organization as “the promotion and maintenance of the highest degree of physical, mental and social well-being of workers in all occupations; the prevention among workers of departures from health caused by their working conditions; the protection of workers in their employment from risks resulting from factors adverse to health; the placing and maintenance of the worker in an occupational environment adapted to his physiological equipment and, to summarize, the adaptation of work to man and of each man to his job.” This formulation supersedes earlier understanding of occu-
pational disease and of safety, to take account of the wider range of circumstances in which work takes place. However, long-standing problems remain important in many parts of the world. For example, hundreds of Chinese mine workers continue to be killed annually while working, largely in comparatively small operations in the private sector which may or may not be properly registered and regulated. In most parts of the developing world, workers in industries such as fishing and construction face daily threats to their safety and rarely, if at all, receive the training that they should have or access to the safety equipment designed to protect them. In some cases, this results from the desire to minimize costs by cutting corners, but in other cases, it might result from the need to work in difficult or unpleasant conditions in which the use of safety equipment is refused by workers because of the heat, humidity, or some other environmental factor. Without the possibility of legal intervention, there is insufficient motivation for all employers to protect their employees, which has been shown on numerous occasions throughout history. Because employers exist in both the private and public sectors in nearly all countries, national law alone is rarely sufficient to provide enough guidance and power for all organizations in society. Consequently, while states will enact their own regulations to protect employees, they must also adhere to supranational regulations such as those provided by, for example, the European Union or through the ILO. These supranational organizations generally provide a level of protection which may be below that provided by individual developed states but above that effectively provided by developing nations. Hence, in the latter cases, the regulations act as aspirations for governments and certain amounts of technical advice and assistance to developing state governments to achieve the necessary level. Appealing to employers on the moral level to provide better protection to employees is rarely effective. Appealing in addition to the economic imperative and the impact on efficiency of accidents is more successful—if a skilled worker is killed or seriously injured at work, for example, it can be expensive to find and train a replacement, especially in the case of those workplaces in which a great deal of specialized knowledge is obtained on the job.
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The dimensions of occupational health that are considered important have expanded in number and depth as understanding of health has improved over the years. It is clear that working in close conjunction with machines that might saw logs or crush metal ores represents a real physical danger to the machine operators. Consequently, operators need proper training and supervision and in some cases protective clothing. The workers themselves have the responsibility of behaving in an appropriate manner when at work and should not arrive at work intoxicated or otherwise recklessly endangering themselves or others. Workplace contracts should reflect the mutual responsibilities that both parties have. In addition to this kind of physical danger, there are also possible problems with excessive noise, pollution, or contaminants in the air; with exposure to dangerous substances; and such newly emerging issues as repetitive stress injury (RSI), which have only become important as new forms of workplace behavior have become standard. In the 20th century, many buildings were fitted with asbestos for purposes of insulation. When the dangers now known to be associated with asbestos became more established, it became necessary to design ways of safely removing it, protecting people who might live or work in the affected buildings and to consider reparations for those workers who had used the substance previously and subsequently been badly affected. The possibility of litigation to establish culpability for occupational health issues has also become an important part of the overall subject. Social factors have also come to be recognized as part of the concern of occupational health. Stress, for example, when it has been caused by some kind of workplace-related health issue. might leave the employer liable for blame. For example, discrimination against employees on the basis of race, religion, or other personal factor has come to be understood as unacceptable; consequently, if the employer has allowed this to happen through negligence, then this is a situation in which the occupational health laws might be used. Of course, proving causality in this case can be problematic. Because stress and related conditions increasingly lead to absence from work, in addition to newly emerging conditions such as RSI, it is sensible for an employer to be aware of the relevant ergonomic issues and be
1274 Occupational Injuries proactive in providing advice and assistance to employees to reduce that level of absence and, hence, increase productivity. SEE ALSO: Occupational Injuries; Occupational Medicine;
Occupational Safety and Health Administration (OSHA).
BIBLIOGRAPHY. Barry S. Levy, et al., Occupational and
Environmental Health: Recognizing and Preventing Disease and Injury, 5th ed. (Lippincott, Williams and Wilkins, 2005); Occupational Safety and Health Administration, www.osha.gov (cited July 2007); Ann Wilcock, An Occupational Perspective of Health, 2nd ed. (Slack, 2006); John Walsh Shinawatra University
Occupational Injuries Occupational injuries are any health problem resulting directly from activities which take place when the patient was at the workplace or in some other way which result from working in a specific job. The occupations which most clearly and often startlingly suffer from high incidence of occupational injuries include the military services, as recent conflicts have made clear. Other occupations at particular risk include those related to mining, sports and, recently, journalism. In the past, such an injury would be regarded as an Act of God and, consequently, the afflicted would have no call on resources or compensation to make up for loss of good health and livelihood. According to custom and discretion, a small pension might be made available to some employees, as for example in the case of the Chelsea Pensioners in Britain, who were former service personnel supported at the crown’s expense. In more recent times, the organization of labour around the world has led to the creation of compensation schemes for workers suffering permanent loss and social welfare schemes to assist workers with temporary illness and inability to work. Many developed countries also offer schemes partly or wholly funded by the state to deal with these issues. In addition, legislation may have been
passed making it possible either for the state to prosecute employers whose negligence had led to the injury for recovery of damages or else makes provision for the affected to sue such people on a civil basis. In addition, as certain employees in highlyskilled or otherwise valuable areas may face certain risks, then insurance schemes may be taken out to ensure that such injuries do not cause financial loss to employers, as well as the employees themselves. Such schemes are increasingly common among very highly-paid and vulnerable workers such as elite athletes, who may also wish to take out insurance on their own behalf. A survey in the USA in 2005 revealed that occupational injuries occurred at the rate of 4.6 cases per 100 full time working equivalents in the private sector. The proportion was higher for goods-producing industries (6.2 cases per 100) than for service-producing industries (4.1 cases per 100), although in both cases small but measurable decreases were noted from the previous survey. These figures are much lower than in other countries with lower occupational health standards or which work with equipment or machinery which would be considered obsolete in the developed world. Just as in the United States, those workers operating heavy machinery, transportation vehicles and in dangerous environments (e.g. underground, at sea or in an environment with hazardous materials present) face higher risks than those in clerical or managerial positions. Not only is the incidence of occupational injury or disease higher in those cases but also the severity of the health problems may be heightened. In the international context, countries which are members of the International Labour Organization (ILO) of the United Nations are obliged to follow the provisions of the Convention No.121, which is entitled ‘Employment Injury Benefits Convention, 1964.’ This convention specifies the obligations of member governments in aiming to minimize the occurrence of occupational injuries and their requirements in compensating those who may suffer from them. Attempts are made to identify those cases in which particular risks may be tolerated and when the state concerned might be excused from abiding by the requirements. However, the expectation is that states will realize the benefits in society as a whole in both monitoring
Occupational Medicine
possible risks to occupational health and to encourage the highest possible standards of safety. The nature of occupational injury has of course changed in history. Previously, workers were expected to handle materials such as lead and asbestos which would now be considered unacceptable without proper protective gear and procedures. Improvements in technology in industries such as fishing have also led to a reduction in the number of injuries and deaths in those sectors, although these continue to be risky areas, especially when employers have powerful cost-based incentives to reduce safety and training standards without any effective or likely sanction. Societal change also has an impact, as it is no longer common for workers to expect to smoke cigarettes or be under the influence of alcohol or intoxicants in the workplace as it once was and no longer considered acceptable. Employees also have an obligation to ensure that they participate in appropriate training schemes and to wear safety equipment and follow procedures which promote injury avoidance. In developing countries, ignorance or cost issues might mitigate against employees following the best standards to protect themselves and their fellows. As work place activities tend to change, new forms of injury and disease emerge as important. For example, the many hundreds of thousands of people whose jobs involve them working intensively with a keyboard and computer may suffer from repetitive strain injury (RSI) or else from back problems related to working posture. The science of ergonomics has continued to gain in importance in identifying situations in which problems might occur and suggesting solutions to them. SEE ALSO: Occupational Health; Occupational Medicine;
Occupational Safety and Health Administration (OSHA).
BIBLIOGRAPHY. Bureau of Labor Statistics, U.S. Depart-
ment of Labor, “Workplace Injury and Illness Summary,” http://www.bls.gov/news.release/osh.nr0.htm (cited July 2007); International Labour Organization, “C121: Employment Injuries Benefit Convention, 1964,” http://www.itcilo. it/actrav/osh_es/m%F3dulos/legis/c121 (cited July 2007). John Walsh Shinawatra University
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Occupational Medicine In the early 1930s, America’s worst workplace injuries began to unfold in a town in West Virginia called Gauley Bridge. Workers there were mining a mountain, and most did not wear protective equipment such as masks. During this time, respiratory illnesses such as silicosis, where the lungs get infiltrated with silica and get fibrotic, increased in incidence. Workers were getting fatally sick, and according to many reports, fatality rates approached sixty five percent. This was the first event in American history where workers became ill on a large scale, and death was attributed to environmental condition rather than misfortune. This incident raised public concern over the health of workers at the worksite, and in the years that followed, there was more attention placed on policies to increase the health of employees. In 1970, both the National Institute for Occupational Safety and Health (NIOSH) and the Occupational Safety and Health Administration (OSHA) were created, paving the way for better national oversight and regulation of worksite conditions and the health of the American workplace. Board Certification in Occupational Medicine Occupational medicine is now a medical subspecialty governed by the American Board of Preventive Medicine. Physicians trained in Occupational Medicine generally undergo four years of medical school training, followed by at least one year of clinical internship training in the United States. Physicians then usually complete an accredited residency, for the most part in primary care, and attain a valid state medical license. Physicians desiring board certification in Occupational Medicine then complete a residency in Occupational Medicine, which is usually a two-year program. Sectors of Occupational Medicine In addition to determining the health status of employees, a large component of the physician’s role in Occupational Medicine is to inform policy changes at the business, local, state, and national levels as well as to assist with claims relating to workplace injury or illness. Examples of the different sectors of Occupational Medicine are included here:
1276 Occupational Safety and Health Administration (OSHA) a. Business: Exxon-Mobil employs a 500-member team that includes physicians and nurses to improve health and safety. ExxonMobil Biomedical Sciences, Inc. (EMBSI) is a 150-member organization dedicated to helping the Corporation achieve safety. Health, and environmental objectives, and assists employees through its company-wide programs such as StopAIDS, malaria control program, and health reporting system. b. Local: several hospitals and local agencies employ physicians trained in Occupational Medicine to assist in employee screenings, vaccinations, wellness programming, and to assist in filing Workman’s Compensation claims. c. State: state governments operate clinics throughout the state, each usually directed by a physician who is board certified in Occupational Medicine. The clinics usually offer several services from diagnoses of work-related illness to generating reports that include recommendations for limiting workplace hazards. d. National: NIOSH and other national agencies employ physicians trained in Occupational Medicine to assist with research projects and informing nationwide policy. Occupational Medicine and the Future As more people garner employment and spend more time at the workplace, healthcare at the workplace will continue to be an important component of the American medical system. The future looks very bright for the field of Occupational Medicine. It will probably be the case that medicine will expand its offerings to the worksite, as more physicians and healthcare teams will be located within worksites. Employers may soon recognize the cost-effectiveness of increasing employee health, decreasing sick days, and increasing employee satisfaction and productivity. During lunch hour, employees of the future may be able to exercise at an on-site facility funded by the employer’s insurance provider, obtain mental health services, or even obtain vaccinations and blood pressure screenings. In short, medicine at the worksite may be more accessible, with the hope of making worksites not only a safe place to be, but also an enjoyable one as well.
SEE ALSO: Occupational Health; Occupational Injuries;
Occupational Safety and Health Administration (OSHA).
BIBLIOGRAPHY. Ware G. Kuschner and Paul Stark, “Oc-
cupational Lung Disease,” Postgraduate Medicine Journal (v.113/4, 2003); National Institute for Occupational Safety and Health (NIOSH) website, www.cdc.gov/niosh/homepage.html (cited January 2007); American Board of Preventive Medicine (ABPM) website, www.abpm.org (cited January 2007); ExxonMobil website, “Workforce Health,” www. exxonmobil.com/corporate/citizenship/ccr5/workforce_ health.asp (cited January 2007); Occupational Medicine Journal, occmed.oxfordjournals.org (cited January 2007). Bradley E. Goldstein, MS, MPH Lake Erie College of Osteopathic Medicine
Occupational Safety and Health Administration (OSHA) As part of the Department of Labor, the Occupational Safety and Health Administration (OSHA) is charged with promoting the safety and health of America’s workers. OSHA carries out this task by endeavoring to convince all employers that it is in their best interests to promote worker health and safety. OSHA’s immediate focus is to reduce workplace fatalities by at least 15 percent and slash work-related injuries and illnesses by 20 percent. Specific targets focus on eliminating amputations caused by manufacturing and construction accidents, ergonomics, blood-lead levels, and silica-related disease. Officials have identified three strategies for fulfilling OSHA’s mission: direct intervention, including identification of situations that lead to problems, eliminating hazards when possible, and reducing workday injuries by 5 percent each year; providing compliance assistance, cooperative programs, and strong leadership through communication with employers, data assessment, collaborations, training, and emergency preparedness; and maximizing effectiveness and efficiency of OSHA’s capabilities and infrastructure through improved data collection and evaluation tools, vigilant monitoring and intelligence, enhanced knowledge, and better management of hu-
Occupational Safety and Health Administration (OSHA)
man capital. Since the creation of OSHA, workplace fatalities have been reduced by more than 60 percent and job-related injuries and illness by 40 percent. OSHA was established by the Occupational Safety and Health Act of 1970, also known as the WilliamsSteiger Act, in response to concerns about the affect of work-related injuries and illnesses on the productivity and profitability of the business sector, which in turn affected interstate commerce. The number of work-related disabilities had increased by 20 percent over the previous decade, and 14,000 job-related deaths occurred each year. The Act also authorized the Secretary of Labor to establish mandatory occupational health and safety standards and created the Occupational Safety and Heath Review Commission to fulfill an adjudicatory function. Congress required all employers to provide workplaces that were “free from recognized hazards that are causing or are likely to cause death or serious physical harm.” Employees were notified that they were expected to comply with all federal standards and take reasonable care for their own health and safety. OHSA initially depended on voluntary compliance, but when this proved ineffective, the focus switched to targeting specific hot spot areas through monitoring and enforcement. In cooperation with OSHA, states began establishing their own OSHA programs, forcing businesses to comply with both state and federal regulations. In the 1980s as part of the deregulation of the Reagan administration, regulations were minimized, and OSHA turned to computers to track compliance and violations. Public and advocacy pressure subsequently forced the introduction of new health standards that allowed employees access to their own medical and exposure records, and a number of class action lawsuits led to greater employer accountability and enhanced public awareness of workplace hazards. OSHA became heavily involved in enforcing standards to protect employees who were being exposed to asbestos, ethylene oxide, formaldehyde, and benzenes. OSHA’s focus of attention was also on high-risk areas that involved fire protection, electrical safety, agricultural field safety, grain handling, hazardous waste and energy sites, and biological hazards. In 1990, maximum penalties for violating OHSA standards were increased from $1,000 to $7,000 for serious violations. Businesses that repeatedly violated OSHA standards were subject to fines of $10,000 to $70,000. The Site-Specific Target
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Program of 1999 provided OSHA with the ability to directly focus attention on workplaces with high rates of injuries and illnesses and on those with the worst health and safety records. In the 21st century, the focal point of OHSA activities continues to be on enforcement, outreach, education, and compliance assistance. Operating within a budget of $468.1 million, OSHA employs more than 2,200 employees, including 1,100 field inspectors. OSHA is located at 200 Constitution Avenue, NW, Washington, D.C. 20210. The OSHA Web site (http:// www.osha.gov/) was designed to provide resources for employees, employers, and government officials and to offer advice on dealing with specific health and safety hazards. Publications are available for download on the site. Both the 24/7 hotline (1-800-321-OSHA) and the Web site provide information in Spanish, and a variety of training materials have been translated into this language. Regional offices offer information and assistance in many languages, including Spanish, Japanese, Korean, and Polish. Through cooperative programs, OSHA brings employers, labor unions, trade and professional groups, government agencies, and educational institutions together to address the issue of workplace health and safety. OSHA’s incentive program, the Safety and Health Achievement Recognition Program, offers employers support for implementing on-site health and safety programs and recognizes outstanding achievements in the field. Participants in the Voluntary Protection Programs experience injuries and illnesses at a rate of 50 percent below industry averages. SEE ALSO: Occupational Health; Occupational Injuries;
Occupational Medicine.
BIBLIOGRAPHY. “All about OSHA,” http://www.osha.
gov/Publications/all_about_OSHA.pdf; Stephen Bonner and John Harrison, Dangerous Trades: History of Health and Safety at Work (Thoemmes Continuum, 2004); Kristine Gebbie, et al., eds., Who Will Keep the Public Healthy? Educating Public Health Professionals for the 21st Century (National Academy Press, 2003); David Koh, et al., eds., Textbook of Occupational Medicine Practice (World Scientific Publishing Company, Inc., 2001); Occupational Safety and Health Administration, http://www.osha.gov (cited July 2007); Earl Wysong, High Risks and High Stakes: Health Professionals, Politics, and Policy (Greenwood,
1278 Oman 1992); Lorri A. Zipperer, ed., The Health Care Almanac: A Resource Guide to the Medical Field (American Medical Association, 1995). Elizabeth R. Purdy, Ph.D. Independent Scholar
Oman Oman is a small sultanate on the eastern edge of the Arabian Peninsula. It is bounded by the United Arab Emirates to the north, Yemen to the south, and Saudi Arabia to the west; its eastern shoreline stretches from the Gulf of Oman to the open waters of the Arabian Sea. Beyond the narrow Al-Batinah coastal plain and the Al-Hajar mountains is a wide interior desert covering a wealth of oil and natural gas. Since 1970, oil has been the key factor in Omani life, and has dramatically improved the health and welfare of its people. At 212,960 square kilometers, Oman is roughly the size of Kansas. The population is 3,102,229 and growing at 3.28 percent a year. The birth rate is 36.24 per 1,000 people, and the fertility rate is 5.77 children per woman. Life expectancy at birth is 71.14 years for men and 75.72 year for women. Most Omanis live in urban areas, with only 27 percent of the population classified as rural. Population density is low at eight people per square kilometer. Native Omanis are ethnically Arab, and 75 percent are Ibadhi Muslim. Like many Gulf states, Oman has a large immigrant population, with 577,293 nonnationals living there in 2006. Most of these immigrants are from south Asia, and they fill the majority of the country’s low-paying, service-industry jobs. The World Bank classifies Oman as an upper-middle income nation, with an average per capita income of $7,830 a year. Sultan Qaboos bin Said al-Said has been the ruling monarch since 1970, and has poured untold amounts of money into Oman’s medical infrastructure. Healthcare is free and universal. Under his rule, life expectancy has risen from around 50 years to 73 years. The Ministry of Health is the country’s main health services provider. It maintains a network of hospitals and clinics across the country and oversees hospitals run by Sultan Qaboos University Hospital, the Minis-
try of Defense, the Royal Oman Police and Petroleum Development of Oman, as well as a growing number of private hospitals and clinics. The Ministry of Health also runs the Central Blood Bank and pharmaceutical distribution through the Directorate General of Pharmaceutical Affairs. The sultanate has long been dependent on expatriate healthcare professionals. In 2005, only 27 percent of doctors and 59 percent of nurses were Omani. Under the Sultan’s urging, the Ministry of Health has launched a program of “Omanization,” increasing training programs for nurses and technicians and promoting medical school programs. It is expected to take several years for these efforts to take off. Oman has virtually eliminated several major communicable diseases. The immunization rate for children is 99 percent. Malaria cases have dropped from 30,000 a year in 1990 to 547 in 2005. The HIV/AIDS rate is 0.1 percent, and there is an active control program for all sexually transmitted diseases. Most deaths in Oman come from noncommunicable causes, primarily vascular diseases. In urban areas, up to 50 percent of the population are overweight, increasing the rates of diabetes and heart disease. As quality of life increases, Oman will have to find a way to educate citizens in the dangers these lifestyle-related risks. Challenges also remain in healthcare for women and children. A 2002 study found that 38 percent of Omani women marry a first cousin and 52 percent marry a second cousin. SEE ALSO: Healthcare, Africa. BIBLIOGRAPHY. American College of Physicians—Ameri-
can Society of Internal Medicine, Cross-Cultural Medicine, Judyann Bigby, ed. (American College of Physicians, 2001). Heather K. Michon Independent Scholar
Onchocerciasis The world’s second leading infectious cause of blindness, onchocerciasis affects 17.7 million people, 99
Oncologist
percent of whom live in Africa. A parasitic disease caused by the filiarial worm, Onchocerca volvulus, onchocerciasis is transmitted from human to human through the bite of infected Simulium black flies. The disease is most intensely transmitted among impoverished populations, primarily in rural African villages located near rapidly flowing streams, giving onchocerciasis its common name of “river blindness.” Biological Impact Onchocerciasis is caused when the body reacts to the presence of microscopic forms of O. volvulus. These worms can live under the skin and in other tissues for up to 14 years. As the worms grow, they mate and reproduce, spreading millions of new microfiliariae to other parts of the body. Itching, rashes, as well as skin depigmentation and nodules can develop as microfiliariae find loci in which to settle and grow. The most destructive consequence, however, is blindness, which is caused by long-term growth of O. volvulus in parts of the eye. Social Impact As a chronic infection, onchocerciasis inflicts severe social problems upon its victims. People with the disease often suffer severe disability, especially blindness, and frequently are unable to work. Fearful of this most extreme manifestation, communities have often abandoned highly fertile areas of soil based near rivers. This trend has impeded social and economic development in badly hit rural areas of Africa. Prevention, Treatment, and Control Prevention and control measures against onchocerciasis include insecticide spraying to control blackflies. For instance, in West Africa, a World Health Organization-sponsored control program was able to widely reduce onchocerciasis by applying insecticides via aerial spraying over breeding sites of Simulium blackflies near fast-flowing rivers. However, given the long life cycle of the O. volvulus worms, these control efforts have failed at eradicating the disease in other parts of Africa. Thus, in 1995, the World Health Organization launched an Africa program to eliminate onchocerciasis by creating sustainable distribution systems, within communities, that would deliver ivermectin, a highly effective treatment, to at-risk
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and infected individuals. These efforts will eventually cover 59 million people throughout Africa. The goals of this campaign are to eliminate onchocerciasis as a serious public health problem and alleviate the social and economic hardships in individuals suffering from onchocerciasis-induced disability. SEE ALSO: Eye Diseases (General); Healthcare, Africa;
Healthcare, Asia and Oceania; Parasitic Diseases.
BIBLIOGRAPHY. Division of Parasitic Diseases at the Cen-
ters for Disease Control and Prevention, “Onchocerciasis,” www.cdc.gov/Ncidod/dpd/ (cited October 2006); J. K. Lazdins-Helds, J. H. F. Remme, and B. Boakye, “Onchocerciasis,” Nature Reviews Microbiology (v.1, 2003); The World Health Organization Special Programme for Research and Training in Tropical Diseases, “Onchocerciasis Disease Information,” www.who.int/tdr (cited October 2006). Rajesh Panjabi, MPH University of North Carolina–Chapel Hill
Oncologist An oncologist is someone who works on cancer research or cancer treatment, coming from the word oncology which in turn derives from the Greek work onkos (ογκος), meaning a mass or tumor, with –ology meaning a study of a particular topic. An oncologist may work privately, for a hospital, for a pharmaceutical company, or for a medical research institute, and may be involved in not only the diagnosis of cancer and therapy such as surgery, chemotherapy, and radiotherapy, but also other procedures connected with the treatment of cancer patients. These may involve general and specific ethical questions surrounding cancer care; counseling of cancer patients and their families before, during, and after cancer treatment; palliative care of patients suffering from terminal cancer; and in screening of members of the general public (such as mass screening for breast cancer) and also relatives of cancer victims when cancers are thought to be hereditary. There are many oncologists throughout the world, with much new research not only carried out in the large and well-funded medical research institutes
1280 Oncology in the United States and western Europe, but also throughout the world with cancer registries maintained in most countries. These collect data relating to cancer deaths in the particular country, which are then tabulated to allow statisticians to work out possible causes to aid oncologists to work on the development of cancer treatment. The annual Charles F. Kettering Prize of the General Motors Cancer Foundation is awarded for cancer treatment with most of its awards being made to oncologists. There are many journals for oncologists such as the American Journal of Clinical Oncology; Journal of Clinical Hematology and Oncology; European Journal of Gynaecological Oncology; International Journal of Radiation Oncology, Biology, Physics; Radiation Oncology Investigations; Hematological Oncology; Endocurietherapy/ Hypothermia Oncology; Oncology News; and Radiation Oncology Investigations. SEE ALSO: Cancer (General); Oncology. BIBLIOGRAPHY. J. Geoffrey Golson and Graham A. Cold-
itz, eds., The Encyclopedia of Cancer and Society (Sage, 2007); James S. Olson, Bathsheba’s Breast: Women, Cancer and History (Johns Hopkins University Press, 2002); Ronald W. Raven, The Theory and Practice of Oncology (Parthenon, 1990). Justin Corfield Geelong Grammar School
Oncology Oncology is the term used to define the branch of medicine that studies tumors—cancer—and is involved in the diagnosis, treatment, and prevention of cancer. The word comes from the Greek onkos meaning “tumor,” with –ology meaning “the study of.” The major roles in the discipline of oncology are to work out the best and most accurate forms of the diagnosis of cancer, and develop plans and then carry out methods of therapy. Traditionally, this has been through surgery, with early oncologists known as cancer surgeons. Now, there are many other ways of treating tumors, including chemotherapy and radiotherapy. If there is successful treatment of a patient,
then oncology is concerned with follow-up care to ensure that the patient makes a full recovery and does not develop any more cancers (if these can be prevented); but there is also the need for palliative care for patients with terminal malignancies. Oncology has now also moved to cover the prevention of cancer, mainly through raising the awareness of activities that make people develop a higher prevalence of cancer. Combined with this, it has found to be also important to screen many people, especially relatives of those who have cancers that are believed to be hereditary, to ensure that early diagnosis might lead to faster treatment, which then has a much higher level of success. One of the major methods of diagnosis of cancer has always been a physical examination of a patient. Many people are taught to involve themselves in selfexamination on a regular basis and seek medical advice for any lumps or cancer-like tumors they come across. For many others, a biopsy (incisional or excisional) is performed, and the tissue is then studied to form a more accurate diagnosis. There has also been the use of blood tests, including the use of tumor markers which can increase the chances of finding out whether someone has a certain type of tumor. However, for tumors that may be located in parts of the body that cannot be physically examined, endoscopy has been used for many years. There is now also much greater use of X-rays, computed tomography (CT) scanning, magnetic resonance imaging (MRI) scanning, ultrasound, and other radiological techniques, with radiologists being important in both the diagnosis of cancer, and also its treatment. Scintigraphy, positron emission tomography, and other methods of nuclear medicine are also used when appropriate. The traditional form of therapy has always been surgery, which involves a medical attempt to remove the entire tumor. This is only possible when there is some certainty that a tumor could be removed in its entirety, and it is not able to be done when the tumor is attached to a tissue of which the removal might risk the life of the person, such as the brain; or where it is clear that the cancer has spread extensively within the person and surgery alone will not solve the problem. The concept of surgery to cure people suffering from tumors has been known since ancient times. Certainly, the ancient Greek doctor, Hippocrates from the is-
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It was the development of X-rays, and then radiology, that made a major change in cancer treatment. Today the focus is on chemotherapy and radiotherapy as being new and effective ways of treating cancer, sometimes used in conjunction with traditional surgery.
land of Cos in the Mediterranean, was able to identify some medical problems to do with hard swellings and ulcers which tended to become fatal. His theory was that these cancers came from an imbalance in fluids, especially an eruption of black bile. The theory had much superficial logic, and the ancient Greeks did resort to excision of tumors, very quickly discovering that it did not always work, and to achieve any chance of success, a large excision would have to be done to ensure that all the tumor was removed. The Greeks realized that the cancer spread and held on to the body like a crab, with Hippocrates giving it the name karkinos, the word for crab, which still remains the symbol for cancer, and is from where the word carcinoma is derived. The famous Roman medical writer Galen was to later build on this theory for his own views on
cancer, and the Romans also used excision. Even the Scythians in eastern Europe from the seventh to the third centuries bce used excision, with many peoples in the ancient world also augmenting surgery with use of herbal treatments and pastes which often did much to calm patients, which sometimes, in itself, helped the treatment of the cancer. In the Middle Ages, excision, often by barber surgeons, tended to be the way that cancers were treated. It was also a period of great advances in medical knowledge in the Arab world, with Avicenna, from Baghdad, writing his Canon of Medicine in which he described how a cancer grows and gradually takes over the human body. He is also said to be the first person to describe cancer of the esophagus. The Moorish doctor Averzoar operated from Cordoba
1282 Oncology in Spain. Elsewhere in Europe, John of Arderne and Guy de Chauliac were prominent cancer surgeons in England and France, respectively. With surgery still the major form of treatment, the causes of cancer remained largely unknown. The next major development in the field of oncology was the discovery of the lymphatic system by Gaspare Aselli and the thoracic duct by Jean Pecquet. With the development of the printing press, a number of medical works were published during this period and this allowed a much wider availability of research work of men such as German surgeon William Fabry and Marco Aurelio Severini, who studied breast cancer. Indeed, Severini was the first person to use illustrations in a book to show the various different types of lesions. Although surgery remained the method of treating cancer until the end of the 19th century, some doctors were coming close to working out some of the causes. Sir Percivall Pott in Britain managed to come to some important conclusions about the cancer carcinogens. He noticed the large prevalence of scrotal cancer in chimney sweeps and was able to develop a theory about occupational cancer which was later proven to be accurate. It was the development of X-rays, and then radiology, by Wilhelm Conrad Röntgen, that made a major change in cancer treatment, earning Röntgen the first Nobel Prize for Physics in 1901. Röntgen refused to patent his invention, and its use spread rapidly. Marie and Pierre Curie in Paris both decided to develop his ideas with Marie Curie being able to isolate radium, and in 1911 being awarded the Nobel Prize for Chemistry for her work. This meant that there was a new method of treating cancer, especially tumors that had spread too much for surgery or were located in body tissue that could not be excised, either because of the importance of an organ, or because of its inaccessibility. This led to a focus on chemotherapy and radiotherapy as being new and effective ways of treating cancer, sometimes used in conjunction with traditional surgery. Even when surgery was used, there has always been some risk that a part of the tumor, however small, might have remained. Radiotherapy or chemotherapy can then be used to destroy what remains of the cancer. In this way, doctors were able not only to prolong life, but also the quality of life for patients. During the 1930s, it was found that hormone manipulation could also be effective, especially for
treating breast and prostate cancers. Nuclear medicine developed forms of treatment even further, and now it has been estimated that in the Western world, some 50 percent of cancer cases could be cured with radical treatment. However, for those who cannot be treated, there are many methods of palliative care that have also been developed. During the second half of the 20th century, there were a number of major causes of cancer that were identified, making the work of oncologists easier, by working to reduce some of the most obvious causes. Rachel Carson highlighted the possibility of cancer from overuse of pesticides in her book Silent Spring (1962), although she held back from alleging a definite link in the book. The British medical researcher Sir Richard Doll of the University of Oxford managed to prove a conclusive relationship between smoking tobacco and lung cancer, leading to large campaigns against smoking, which has led to a very significant downturn in smoking in developed countries, and health warnings needing to be included on each packet of cigarette sold. There has also been much greater awareness of breast cancer with women around the world encouraged to be tested, leading to much earlier diagnosis for many of them. In the late 1980s, there became increasing awareness of skin cancer, with campaigns to stop children developing skin cancers in many countries since the 1990s. Not only have medical services around the world and private pharmaceutical companies invested vast sums of money into trying to find ways of treating cancer, but there have also been a number of major initiatives, with the “War on Cancer” proclaimed by Richard Nixon in his State of the Union address in January 1971. The promotion of cancer research, the large funds available to fund research into large numbers of areas, and also support from charities and charitable foundations have ensured that oncology continues to draw some of the best medical minds. The Charles F. Kettering Prize of the General Motors Cancer Foundation is awarded annually for work in cancer treatment, and this has been given to many prominent people working in various fields of oncology such as Malcolm Bagshaw, Sir David Cox, Brian J. Druker, Lawrence H. Einhorn, Mortimer M. Elkind, Emil Frei III, Emil J. Freireich, Basil I. Hirschowitz, Elwood V. Jensen, Henry S. Kaplan, David E. Kuhl, Paul C. Lauterbur (who also shared the 2003 Nobel Prize
Ophthalmologist
for Physiology or Medicine), Ronald Levy, Victor Ling, Nicholas B. Lydon, Michael E. Phelps, Donald P. Pinkel, Barnett Rosenberg, Sam Shapiro, Howard Skipper, Philip Strax, Herman D. Suit, E. Donnall Thomas, Monroe E. Wall, Patrick C. Walsh, Mansukhal Wani, and H. Rodney Withers. Other important people in the field of oncology in the latter half of the 20th century include the Australians Professor Bruce Armstrong and Adele C. Green, and also John Christian Bailar III, Gianni Bonadonna, Norbert Brock, Laurent Degos, Roy S. Herbst, Deimitrios Trichopoulos, James Dewey Watson, Robert A. Weinberg, and Ernst Ludwig Wynder. SEE ALSO: Cancer (General); Cancer Alternative Therapy;
Cancer Chemotherapy; Cancer Radiation Therapy; Oncologist; Oncology. BIBLIOGRAPHY. Nathaniel I. Berlin, “The Conquest of
Cancer,” Perspectives in Biology and Medicine (v.22, 1979); Lester Breslow, A History of Cancer Control in the United States 1946–1971 (National Institutes of Health, National Cancer Institute, 1977); Barrie R. Cassileth, “The Evolution of Oncology,” Perspectives in Biology and Medicine (v.26, 1988); Graham A. Colditz, ed., The Encyclopedia of Cancer and Society (Sage, 2007); Bernard Glemser, Man against Cancer: Research & Progress (Bodley Head, 1969); Richard Kluger, Ashes to Ashes (Knopf, 1997); James S. Olson, The History of Cancer: An Annotated Bibliography (Greenwood, 1989); James S. Olson, Bathsheba’s Breast: Women, Cancer and History (Johns Hopkins University Press, 2002); L. J. Rather, The Genesis of Cancer: A Study in the History of Ideas (Johns Hopkins University Press, 1978); Ronald W. Raven, The Theory and Practice of Oncology (Parthenon, 1990); R. A. Rettig, Cancer Crusade: The Story of the National Cancer Act of 1971 (Princeton University Press, 1971. Justin Corfield Geelong Grammar School
Ophthalmologist An ophthalmologist is a medical doctor who specializes in diseases and treatments of the visual system. Ophthalmologists often work closely with optom-
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etrists and usually provide diagnosis and treatment for more serious eye diseases and disorders such as glaucoma, diabetic retinopathy, and cataract. Many ophthalmologists specialize in providing laser surgery to correct refractive error; while this procedure used to be prevalent only in the United States and other wealthy nations, it is now starting to become more widely marketed and used around the world. Ophthalmologists are generally considered to be surgeons because they perform operations on the eye. In order to become an ophthalmologist, a person must complete medical school and go on to additional training in surgery and ophthalmology. In the United States, this training may include an internship or general transitional year along with a residency in ophthalmology which generally lasts four years. Afterward, some ophthalmologists choose to obtain further specialized training through a fellowship dealing with a specific category of ophthalmology classified by disease, anatomical location, or type of surgery. Fellowship subspecialties include but are not limited to the cornea, anterior chamber, retina, glaucoma, and pediatric ophthalmology. While residency programs dealing with ophthalmology remain very attractive and competitive options for medical school graduates in the United States, there is a severe shortage of ophthalmologists in many underserved areas of the developing world today. For example, in Africa, there is an average of 1 ophthalmologist serving every 1 million people, and an even worse ratio may be expected in rural areas. Increased training of ophthalmologists, especially in the field of cataract surgery, is required in order to best reduce the global burden of eye disease. Overall, much more equitable distribution of qualified ophthalmologists is needed worldwide in order to provide important eye care to those who need it. SEE ALSO: Amblyopia; Cataract; Diabetic Eye Problems;
Eye Care; Eye Diseases (General); Glaucoma; Optometrist.
BIBLIOGRAPHY. Sheila West and Alfred Sommer, “Prevention of Blindness and Priorities for the Future,” Bulletin of the World Health Organization (v.73/3, 2001).
Nakul Shekhawat Vanderbilt University
1284 Ophthalmology
Ophthalmology Ophthalmology is the branch of medical science dealing with the anatomy, function, pathology, and treatment of the eye. It encompasses many subspecialties including: cornea and external disease, glaucoma, vitreoretinal diseases, oculoplastic surgery, pediatric ophthalmology, neuro-ophthalmology, and ophthalmic pathology. Ophthalmology has a long history and continues to evolve as new technologies become available. Despite incredible advances, prevention of eye disease and blindness around the world is still a major challenge. Regular eye exams, diagnosis and treatment by qualified ophthalmic specialists remain unaffordable and inaccessible for millions of people. More than 90 percent of the visually impaired people in the world live in developing countries. Throughout these countries, there is approximately one ophthalmologist per 1 million inhabitants. Ophthalmologists are often concentrated in large cities while the majority of the population lives in impoverished, rural areas. Social and economic deprivation experienced by the visually impaired extends throughout a community and results in a socioeconomic downward spiral. This can be reversed through widely available, appropriate, cost-effective preventive and curative interventions. In 1999, the international community initiated Vision 2020: The Right to Sight to eliminate preventable blindness by the year 2020 through integrated, sustainable eye care systems worldwide. One of the many objectives identified by Vision 2020 is the training of ophthalmologists and ancillary eye health care workers in even the most remote communities Ophthalmology is a branch of medical science dealing with the anatomy, function, pathology, and treatment of the eye. Ophthalmologists are medical doctors with several years of specialized training in medical and surgical care of the eye. Ophthalmologists perform eye exams, prescribe glasses and contact lenses, and treat all conditions directly affecting the eye and surrounding muscle, bone, and skin. As conditions that affect various parts of the body can become evident in the eye, ophthalmology is closely associated with other medical fields. Ophthalmologists are able to diagnose conditions with ocular manifestations and refer patients to an appropriate physician for treatment. Following medical school and internship, ophthalmologists often complete fel-
lowships in one of the subspecialties encompassed by ophthalmology: cornea and external disease, glaucoma, vitreoretinal diseases, oculoplastic surgery, pediatric ophthalmology, neuro-ophthalmology, and ophthalmic pathology. Ophthalmic Subspecialties The subspecialty of cornea and external disease involves diagnosis and treatment of diseases affecting the cornea, sclera, conjunctiva and eyelids. This includes corneal dystrophies, microbial infections, conjunctival and corneal tumors, inflammatory processes and anterior ocular manifestations of systemic diseases. Corneal and external disease specialists are trained in corneal transplant surgery and corneal refractive surgery to correct refractive errors. The subspecialty of glaucoma involves management of chronic, acute, congenital, and secondary glaucoma or any condition associated with increased intraocular pressure and optic nerve changes. Glaucoma specialists treat adult and pediatric patients with medication as well as laser iridotomy or trabeculoplasty. The subspecialty of vitreoretinal disease involves both the medical and surgical treatment of diseases of the retina and vitreous body. This includes manifestations of local, systemic and genetic diseases as they affect the retina and vitreous. Diagnosis employs ultrasound, fluorescein angiography and electrophysiology; treatment includes laser therapy, cryotherapy, retinal detachment surgery and vitrectomy. Oculoplastic surgery focuses on orbital surgery, lid and upper facial reconstructive procedures following trauma and tumors, and cosmetic lid surgery. Oculoplastic surgeons are trained in the use of ophthalmic surgery, plastic surgery, radiotherapy, chemotherapy and chemosurgery to treat both ocular and orbital disease. Pediatric ophthalmology deals with the medical and surgical treatment of strabismus, amblyopia, genetic abnormalities, and a wide range of inflammatory, traumatic, developmental, and neoplastic conditions occurring in the first two decades of life. This subspecialty also deals with the ocular manifestations of certain systemic disorders as well as adult ocular motility disorders. Neuro-ophthalmology can be a nonsurgical subspecialty, though it is often combined with surgical treatment of the eye and orbit. Neuroophthalmology deals with local pathology affecting the optic nerve and visual pathways, including intra-
cranial lesions that affect the oculomotor pathways. Ophthalmic Pathology requires training in both pathology and ophthalmology and involves examination of tissue samples obtained from the eye and surrounding area. Throughout human history, there has been a fascination with the eye. Egyptian papyrus dated to approximately 1600 b.c.e. depicts ophthalmology as one of the most advanced medical specialties. Today, ophthalmology continues to evolve as new technologies become available. The dynamic use of computers, microscopes, ultrasound, and light has led to Ophthalmic Computed Tomography (CT), fluorescein and indocyanine green angiography, and wavefront analysis for high-resolution imaging, as well as improved microsurgical instruments and techniques like the microkeratome and microincisional phacoemulsification. The development of instrumentation utilizing the nanosecond Yttrium-aluminum-garnet (YAG) laser, the picosecond Yttrium-lithium-fluoride (YLF) laser, and more recently, the infrared femtosecond laser, has given rise to surgical procedures such as Laser-Assisted In-Situ Keratomileusis (LASIK) and Laser Subepithelial Keratectomy (LASEK) for correction of refractive error, as well as imaging procedures like Confocal Scanning Laser Tomography. Corneal and epithelial transplants, visual prosthetics, and intraocular lenses restore sight as genetically engineered products like human epidermal growth factor, fibernectin, and corneal mortar accelerate wound healing after surgery. Interventions such as gene therapy, photodynamic therapy, anti-vascular endothelial growth factor, antiinfectives, and anti-inflammatories provide treatment for conditions that would otherwise be blinding and/or lethal. Predictive gene testing allows for early diagnosis and treatment while telemedicine allows for diagnosis and treatment when patients and doctors are thousands of miles apart. Global Challenges in Ophthalmology Despite these incredible advances in ophthalmology, prevention of eye disease and blindness around the world is still a major challenge. According to research by the World Health Organization (WHO), in 2002 more than 161 million people were visually impaired, of whom 124 million people had low vision and 37 million were blind. Global statistics on
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refractive error as a cause of visual impairment were not included, implying that the actual magnitude of visual impairment is greater. The International Center for Eyecare Education places the number of blind or visually impaired due solely to refractive error close to 250 million people worldwide. Though individual percentages vary by region, approximately 75 percent of blindness in adults is caused by cataract, glaucoma, corneal opacity, diabetic retinopathy, onchocerciasis, childhood blindness (including Vitamin A deficiency), and trachoma. All of these conditions are potentially preventable and/or treatable. The WHO has unambiguously contended that the perpetuation of these conditions and all ill health is poverty. Vision impairment is both a result of, and barrier to socioeconomic development. Regular eye exams, diagnosis and treatment by qualified ophthalmic specialists, are unaffordable and inaccessible for millions of people. A nationwide study conducted by Lafuma and colleagues suggests that, at the population level there is an inverse correlation between the number of ophthalmologists and the prevalence of visual impairment. Specifically, “the supply of vision-related services may be a determinant of eye morbidity at a national level.” This could partially explain the fact that more than 90 percent of the visually impaired people in the world live in developing countries. Throughout Africa, there is approximately one ophthalmologist per 1 million inhabitants. In countries like India and Vietnam where the number of ophthalmologists per 1 million inhabitants is 12 and 17 respectively, the ophthalmologists are concentrated in large cities while the majority of inhabitants live in impoverished, rural areas. The field of ophthalmology is lacking neither in medical knowledge nor technological advancement, yet it is estimated that the number of individuals with blindness could reach 76 million in the year 2020. In 1999, the WHO, representing national governments, and the International Agency for the Prevention of Blindness (IAPB), representing an international coalition of non-governmental organizations, professional bodies, research and training institutes and other eye care organizations initiated Vision 2020: The Right to Sight. Their goal is to eliminate preventable blindness by the year 2020. This initiative faces many serious obstacles; however, it is a necessary global health investment. The 59th World Health
1286 Optometrist Assembly continued support of Vision 2020, based on recent findings that, without access to medical care, social and economic deprivation experienced by the visually impaired extends throughout a community and results in a socioeconomic downward spiral. This can be reversed through widely available, appropriate, cost-effective preventive and curative interventions. Vision 2020 has identified several objectives for integrated, sustainable eye care and rehabilitation systems worldwide: training ophthalmologists and ancillary eye health care workers in even the most remote communities (including combating “brain drain” or loss of intellectual and technical personnel in developing countries); increasing awareness of visual impairment as a major public health issue; strengthening existing health care infrastructure; controlling cataract, trachoma, onchocerciasis, and childhood blindness; creating affordable pricing and availability of high-quality assistive services, low vision devices and spectacles, surgical supplies, medicine, and technology. SEE ALSO: American Academy of Ophthalmology (AAO);
Eye Care; Eye Diseases (General); National Eye Institute (NEI); Ophthalmologist; Optometrist.
BIBLIOGRAPHY. American Academy of Ophthalmology,
“Envision Ophthalmology: A Practical Guide to Ophthalmology as a Career Choice,” www.aao.org/careers/envision/index.cfm (cited August 2006); International Center for Eyecare Education, www.icee.org/index.asp (cited August 2006); Louis Pizzarello, et al., “VISION 2020: The Right to Sight: A Global Initiative to Eliminate Avoidable Blindness,” Archives of Ophthalmology (v.122, 2004); Serge Resnikoff, et al., “Global Data on Visual Impairment in the Year 2002,” Bulletin of the World Health Organization (v.82, 2004); Vision 2020: The Right to Sight, “A Global Joint Initiative to Eliminate Unnecessary Blindness from the International Agency for the Prevention of Blindness and the World Health Organization,” www.vision-2020.org (cited August 2006); World Health Organization, “Magnitude and causes of visual impairment,” who.int/mediacentre/ factsheets/fs282/en (cited August 2006). Jennifer Hissett University of Colorado at Denver and Health Sciences Center
Optometrist An optometrist, also referred to as a doctor of optometry (OD), is a professional who provides primary eye care to the community. Optometrists examine patients’ eyes to ensure proper eye health. By checking for and diagnosing eye diseases and vision problems such as refractive error, improper color and depth perception, and improper ocular movement or function, optometrists provide the important first line of defense against visual impairment and blindness. While optometrists do not perform surgery or provide more advanced eye care to patients, they are often responsible for providing pre- and postoperative care to eye surgery patients. Most commonly, optometrists prescribe eyeglasses or contact lenses and provide eye-related therapy or rehabilitation. While such services and facilities are considered common in the developed world, they are, nevertheless, vital to the productivity and well-being of much of the world’s population. There has always been a substantial need for optometrists in rural or poverty-stricken regions. However, many optometrists are drawn to more lucrative locations of practice, leaving certain regions of the world sorely lacking in access to primary eye care. While there is usually one optometrist for every 10,000 people in developed countries, the number of people per single optometrist can range from 600,000 to 1 million in developing countries. The implications of this disparity are obvious. For example, in rural India an estimated 86 percent of refractive error remained uncorrected in 2002. Data from other poor regions in Nepal, Chile, and rural China corroborate this and reveal the glaring inequity in access to optometric care. For international eye health efforts such as Vision 2020 to succeed, several educational, economic, and logistical issues must be addressed in order to promote optometry globally and provide important primary eye care to those who need it. SEE ALSO: Eye Care; Ophthalmologist; Ophthalmology;
Snellen’s Chart.
BIBLIOGRAPHY. Brien Holden and Serge Resnikoff, “The
Role of Optometry in Vision 2020,” Community Eye Health
Oral Cancer
Journal (v.15/43, 2002); U.S. Department of Labor, “Optometrists,” www.bls.gov (cited October 2006). Nakul Shekhawat Vanderbilt University
Oral Cancer Squamous cell carcinoma is an epithelium-derived tumor with an incidence of around 36,000 cases per year. Six thousand to 7,000 cases (usually intraoral) lead to painful death due to constriction of airway. Tobacco use has proven to be the leading factor and carcinogen in oral cancer; however, alcohol use, human papillomavirus (HPV) 16, 18, 31, and 33, sunlight (a co-carcinogen), Candida, and oral sepsis are all promoters. In 90 percent of oral cancer patients, there are three factors prevalent: heavy tobacco use (all forms), ingested/topical alcohol, and oral sepsis. Age group, gender, and lifestyle are also considered coexisting components to the etiology of oral cancer but are not necessarily promoters. Furthermore, there are several conditions that may predispose a person to oral cancer: lupus erythematous, atrophic lichen planus/lichenoid dysplasia, avitaminosis A, Plummer-Vinson syndrome (mucosal atrophy—predisposes to esophageal squamous cell carcinoma), tertiary syphilis (used to be treated with arsenic which caused interstitial glossitis and atrophic mucositis; however, this is not seen much anymore), oral submucous fibrosis found in Third World/developing nations where much spicy foods or chemically burning chilies are ingested. Buccal mucosal atrophy, burning and scarringdysplasia.—Squamous Cell Carcinoma is seen in these instances. Tissue is generally thin but hard. Most common sites for oral cancer are not the most common sites for oral irritation; therefore, broken teeth, broken appliances, and galvanism are not leading causes of oral cancer nor is oral cancer as common at these sites. Ninety-five percent of oral cancer occurs in males and 35 percent occur on the lower lip. In Southeast Asia, a slurry of betel quid (mixed betel chew/nut with slag lime and tobacco, combined with a little peyote or hallucinogen) is commonly
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used. Lime is considered the promoter and tobacco the carcinogen in the oral cancer cases seen in this part of the world. Reverse smoking, where the lit end of a cigar or cigarette is held inside the mouth, seen predominantly in Asian cultures and among females (to hide smoking) is also a common etiology of oral cancer in this region. Clinically, oral cancer presents in early or late stages, hence the need for oral cancer screenings in order to identify early lesions. Generally, the lesions are considered to have a worse prognosis as redder, exophytic, or ulcerative nature appears, implying a late-stage cancer. Oral cancer can present as a white lesion (white mucosal patch), white and red mixed lesion (speckled red/white—speckled erythroplakia/leukoplakia), or red lesion (velvety red patch). Biopsy of red areas is always indicated as there is a 95-percent chance of squamous cell carcinoma or carcinoma in situ. Common/high-risk locations are lateral/ventral tongue, oropharynx including soft palate/anterior pillars and posterior pharyngeal wall, floor of mouth, and retromolar area. Few cases are seen on the gingival (spit tobacco) and buccal mucosa (pipe) and there are rarely any cases on the hard palate, dorsal tongue, and labial mucosa due to thick layers of keratin. Lip lesions (usually lower) are generally sunassociated or smoking-associated and are seen in about one-third of all oral cancers. The lesions are smaller, slow growing, and usually detected early. Histologically, they are well differentiated, white, and keratinized. Best treatment is to remove them surgically; the prognosis is good (95 to 98 percent cure) if removed. Tongue lesions (lateral/ventral) are usually associated with smoking, alcohol, and oral sepsis. Histologically, this lesion can be seen from well differentiated to poorly differentiated. Treatment is surgery, radiation, or both, while the prognosis includes metastasis to anterior cervical nodes. If this occurs, neck dissection and radiation are needed. If lesions approach or are into the floor of the mouth, it may be necessary to remove all of the lateral tongue, floor of mouth, and section mandible/neck. Floor of mouth lesions usually affect older men and the anterior areas. As with tongue lesions, they are associated with smoking, oral sepsis, and
1288 Oral Cancer alcohol. Treatment and prognosis are like those seen in the tongue. Gingiva, alveolar ridge, and mucosal lesions are rare; however, they present most often as redder lesions than seen in floor of mouth or tongue. These lesions can be confused with gingivitis, reactive gingival lesions. If gingival therapy is not responding, a biopsy may be performed. Radiographically, this can mimic periodontitis; however, it can create mothy lesions instead of intact lamina dura as seen in periodontal disease. Maxillary sinus has been noted to have squamous cell carcinoma, although it is lined with respiratory epithelium. There is no association with smoking, chronic sinusitis, polyps, or pseudocysts of sinus, but are most often seen in older males. In this location, it often presents as a low-grade sinus infection but is noted to erode bone. Patients are unfortunately treated for sinusitis, thus diagnosed at a late stage (surgical stage 3/4). Destruction of the maxillary sinus is common and patients present with dental problems: toothache/sinus ache—frequently confused with chronic sinusitis. Radiographically (panoramic), these lesions frequently present as an opacity of the sinus (after T2/3 stage). Treatment is based on stage and sometimes involves whole antrums and orbit removal. General signs and symptoms of oral epidermoid cancer (squamous cell carcinoma) are as follows: color—red, white, or both; ulceration or erosion— common in larger T3/4, later-stage lesions; exophytic growth—outward from surface and verrucous/warty growth; induration—firm, much firmer than mucosa to which it is fixed; chronicity—if it has been there a while and not growing/large, then it is probably not oral cancer. If it is a new lesion, it is more likely to be oral cancer; fixation—grown into muscle and connective tissue surrounding it; lymphadenopathy—oral epidermoid cancer invades lymph nodes; most cases elicit an immune response which slows invasion and metastasis. The lesions can present as large, small, flat, raised red, white, or speckled. Proliferate verrucous leukoplakia (PVL) be seen in a generalized area(s) of hyperkeratosis and wart-like thickening of mucous membrane. Over a five-year period, 50 percent of lesions will remain as dysplasia, 25 percent are normal, and 25 percent become cancer. With regards to carcinoma
in situ (CIS), most do eventually become cancer; however, there are cases where the lesion remains in CIS stage. With all cases, behavior is unpredictable; therefore, close monitoring is needed. Diagnosing lesions requires more than a clinical evaluation. White lesions usually do not need biopsy; however, red lesions (or mixed) will require further examination. Biopsy is the only way to establish a diagnosis, although biopsy itself is not definitive. Cytology (scraping cells from surface) is used in red, ulcerative lesions and not keratinized lesions (white). Generally, grade 4 cytology implies cancer, but again, it is not diagnostic. Toluidine blue (T. Blue) is not an invasive procedure. An area of the lesion is painted with T. Blue and stains the nucleic acids. Increased nucleic acids indicates cancer. Normal/dysplastic tissue will not stain with T. Blue and squamous cell carcinoma and carcinoma in situ will stain. Unfortunately, there are problems with using T. Blue. Dorsal tongue, ulcers, carcinoma in situ and squamous cell carcinoma (both positive in 10 percent of the time) can stain positive, while dysplasia is negative (–95 percent of the time). Indications for T. Blue are patient with widespread dysplasia, previous history of squamous cell carcinoma (likely to have two or three lesions), and large suspicious lesions for determination of biopsy site. Factors and prognosis of oral cancer are based on several factors: grade—Broder’s classifications (based on histologic differentiation); stage (TNM— tumor size, nodal involvement, and metastasis system) which has an impact on treatment; location; and growth pattern. Surgical stage is the most valid predictor for treatment and prognosis. The course of oral epidermoid cancer is generally invading and metastasize to cervical lymph nodes, where it usually arrests. It is unusual to go beyond the clavicles. Unfortunately, the invaded tissue is destroyed causing “frozen neck,” choking and bleeding. Patients die a terrible death. Treatment usually requires surgery, if possible, and can be curative; however, 10 to 20 percent can recur as premalignant lesions. Radiation is a possible curative treatment because oral cancers tend to be radiation sensitive. Radiation can be used to shrink large cancers to a surgical size or used postsurgery to eliminate any suspicious borders remain-
Oral Surgeon
ing. Chemotherapy is only palliative in nature. This treatment is often used for any metastasis that is not found. Ninety-nine percent are destroyed the first time leaving only the most resistant to survive. Fewer lesions are killed with each round of chemotherapy, leaving only the most aggressive lesions which increases mortality/morbidity by invasion. Combination therapy is used with the rationale being to shrink large ones to a smaller, manageable surgical size. The process is generally to remove the tumor and radiate the remaining tissue. Lesions/tumors that are associated with p53 mutations are possibly more aggressive. SEE ALSO: Cancer (General); Cancer Alternative Therapy;
Cancer Chemotherapy; Cancer Radiation Therapy; Cancer—Coping with Cancer. BIBLIOGRAPHY. B. W. Neville, et al., Oral and Maxillofa-
cial Pathology, 2nd ed. (Saunders, 2002).
Justina Kennedy University of Louisville
Oral Rehydration Therapy Oral rehydration therapy (ORT), also called oral rehydration salts/solution (ORS), is a salt and sugar-based solution taken orally to treat dehydration from diarrhea. The salts can be prepackaged and typically include a combination of sodium, glucose, potassium, and citrate to be mixed with clean water; a homemade solution can be prepared in a ratio of eight level-teaspoons of sugar and one level-teaspoon of salt mixed in one liter of clean water. Use of ORT is cheap, effective, and easy to prepare. It can reverse dehydration in more than 90 percent of patients with severe diarrhea. Since the World Health Organization began using ORT in 1978 as its primary means of fighting diarrhea, the annual death rate among children under 5 suffering from acute diarrhea has fallen from 5 million to 1.9 million. Diarrhea is a leading cause of death among children under 5 in developing countries. Research that led to the development of ORT began in 1960 in Dhaka, Bangladesh, when the International Centre for Diarrhoeal Disease Research
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(ICDDR) established a Cholera Research Laboratory to evaluate treatments for cholera. In 1971, an outbreak of cholera among refugees that occurred during the India–Pakistan war rapidly depleted supplies of intravenous saline. This provided an opportunity to use the oral rehydration solution that was being tested at the Johns Hopkins Center for Medical Research and Training in Calcutta. The fatality rate from cholera among refugees fell from 30 percent to 3 percent. Since then, ORT has successfully reduced mortality related to diarrhea throughout the developing world. Drs. Norbert Hirschhorn, Dilip Mahalanabis, David R. Nalin, and Nathaniel F. Pierce were awarded the Pollin Prize for Pediatric Research in recognition of the work in developing ORT in 2002. When a person has diarrhea, not only is fluid lost, but also electrolytes the body needs, including sodium (salt) and potassium, are also lost. ORT works to replenish the body in two ways: Even though the person may still be experiencing diarrhea, sugar or glucose makes the absorption of salt into the intestine more efficient, and salt promotes water’s absorption into the intestinal walls. SEE ALSO: Cholera; Diarrhea. BIBLIOGRAPHY. Rehydration Project, “The Rehydra-
tion Project,” www.rehydrate.org (cited January 27, 2007); World Health Organization, “New Formula for Oral Rehydration Salts Will Save Millions of Lives,” http://www.who. int/mediacentre/news/releases/release35/en/index.html (cited May 2002). Connie Currier, Dr.P.H., M.P.H. Michigan State University
Oral Surgeon An oral and maxillofacial surgeon diagnoses and treats diseases, injuries and abnormalities of the hard and soft tissues of neck, face, head and jaws. Surgical procedures include implants, tissue and bone grafts, complicated extractions, repair and restoration of oral tissues and supporting structures and facial cosmetic surgery. Oral surgeons will also treat injuries to
1290 Organ Donation the teeth and face, including tooth damage, and facial bone fractures. Education includes four years of dental school, followed by an additional four years or more of in-hospital surgical training with residency rotations in internal medicine, general surgery, anesthesiology, otolaryngology, plastic surgery, emergency medicine, and other subspecialties. Oral surgeons are also required to take written national and state boards. Oral surgeons may practice within an office or in a hospital setting. Those in private practice may expand to encompass a wide range of dental, skeletal and facial problems, including the surgical placement of implants and surgeries for temperomandibular joint disorders and cleft palate repair. Oral surgeons may also treat sinus disorders. The use of imaging (X-ray, CT scan and MRI) will allow for examination of bone and supporting structures. The most common procedure performed by an oral surgeon are extractions, including removal of impacted molars that will cause damage to other teeth. Extraction of other teeth may be necessary to prevent damage to underlying bone or gums. An impacted tooth is removed by incision of the overlying tissue and pulling the tooth out with a forceps, or by cutting the bone for easier removal. Managing infections in the teeth and surrounding structures might require excision of the cause and damaged area, surgical drainage and administration of antibiotics. The oral surgeon will make recommendations for post-surgical care and pain management. See ALso: Dental Health; Mouth Disorders, Bibliography. Rebecca W. Smith and Faculty of the Co-
lumbia University School of Dental and Oral Surgery, Columbia University School of Dental and Oral Surgery Guide to Family Dental Care (W.W. Norton & Co, 1997);
Lyn Michaud Independent Scholar
Organ Donation According to current statistics, there are over 91,000 patients in the United States waiting for organ transplants with nearly 4,000 new patients being added to
the wait list each month. Each day, an average of 18 people die while awaiting transplants for a heart, liver, kidney, pancreas, lung, or bone marrow. Although an estimated 12,000 people who die each year meet the criteria for organ donation, fewer than half actually become donors. Organ donation is a safe, carefully coordinated process that is highly successful in saving lives. Unfortunately, individuals’ concerns frequently prevent them from consenting to organ donation at the time of death. As a way to help meet the increasing need for transplanted organs, new techniques have been developed that allow living persons to donate, but even with living organ donation, a great shortage still remains. The failure of a vital organ used to mean certain death for a patient. This all changed in 1954 when the first successful living-related kidney transplant was performed. Less than a decade later, the first successful cadaveric kidney transplant was performed. Since then, the field of transplant surgery has continued to make tremendous advancements. The current survival rate for most vital organ transplants is greater than 80 percent one year after surgery. The success rate for transplanted tissues is even higher at greater than 90 percent. High survival rates following organ transplantation is not only a consequence of improved immunosuppressants and surgical technique, but also of improved organ selection. Donor eligibility depends on age, medical conditions, and circumstances at the time of death. Although donors are typically between the ages of 5 and 60, people both younger and older are able to donate as long as they are in good health. Individuals may express their wishes to be a donor at any time, but prior to actual donation, eligible donors undergo an extensive screening process that involves examining the body, testing for disease, interviewing the donor’s family and close contacts, and reviewing the donor’s medical records and lab results. Conditions that limit organ or tissue donation include active cancer, human immunodeficiency virus (HIV), hepatitis, syphilis, West Nile virus, severe acute respiratory syndrome (SARS), and Creutzfeldt-Jakob disease (commonly known as mad cow disease). One exception to these exclusion criteria involves individuals infected with hepatitis B or C. These individuals may sometimes donate their organs to others who are already infected with hepatitis B or C.
Organ Donation
Individuals wishing to be an organ donor can sign a Uniform Donor Card, which they keep in their wallet, or indicate on their drivers licenses that they wish to donate. However, at the time of brain death, the person’s relatives will still be asked to consent and may choose against donation. It is estimated that about 35 percent of would-be organ and tissue donors never actually donate because family members refuse to give consent. Even if individuals have not indicated that they wish to donate, their family members are still likely to be approached regarding the subject. This is because all hospitals are required by law to notify the local Organ Procurement Organization (OPO) of all patient deaths (including brain death). If the OPO determines that the individual’s organs or tissues are appropriate for donation, it will have a representative contact the patient’s family to offer them the option of donating their loved one’s organs or tissues. Organs that can be donated include the heart, lungs, kidneys, pancreas, and small intestine. Tissues include corneas, skin, bone, heart valves, and connective tissue. Individuals may also choose to donate their bone marrow, which is used primarily in treating patients with leukemia. There are currently a number of issues, including medical care, funeral arrangements, and religious views, that make some individuals hesitant to become organ donors. Some patients fear that their medical care might be affected by the fact that they are an organ donor. However, there are strict legal guidelines that are carefully followed before brain death is declared. The doctors who treat patients while they are ill are not the same physicians who are responsible for organ removal. Organ donation is only considered after every attempt has been made to save a patient’s life. Family members may also be concerned about how organ donation might affect their loved one’s funeral arrangements. These individuals should know that organ donation does not disfigure the body or delay the funeral. Organs are carefully removed in an operating room under sterile conditions, and patients are closed after the procedure as they would be with any surgery. There are no outward signs of organ donation. Finally, individuals may be concerned about their religion’s views toward organ and tissue donation. While Gypsies and Shintoists do indeed oppose organ donation on religious grounds, it is important to point out that
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most major religions and religious denominations have released statements that either support or are indifferent to organ donation. When organs become available, recipients are carefully chosen from a nationwide computer registry called the National Organ Procurement and Transplantation Network (OPTN), operated by United Network for Organ Sharing (UNOS). Criteria used to match recipients with organs include severity of illness, time spent on wait list, blood type, tissue type, body size, and geographical location. Social or financial status are not factors that influence who receives a transplant. Privacy of both donor and recipient are closely guarded. The only information that the recipient may know is the donor’s sex, approximate age, and state in which the individual lived. Unfortunately, there are not enough individuals who choose to donate their organs at the end of life. For this reason, new techniques have recently been developed which enable living individuals to donate a kidney or a portion of their liver, lung, or pancreas. One of the most significant benefits of living organ donation is that it eliminates the need for placement on the national waiting list. Because surgeries can be planned in advanced, the recipient can begin taking immunosuppressants a few days before the operation to decrease the risk of organ rejection. This is not possible for someone who receives a transplant from the waiting list because they must undergo surgery whenever an organ is available. There are also a number of risks that the living donor and recipient must be aware of. All patients experience some pain and discomfort after an operation. As with any major surgery, there are the risks of bleeding, infection, and anesthesia complications. SEE ALSO: Kidney Transplantation; Liver Transplantation;
Lung Transplantation; Pancreas Transplantation; United Network for Organ Sharing (UNOS).
Linda Bren, “Keeping Human Tissue Transplants Safe,” FDA Consumer Magazine (v.39/3, 2005); Mayo Clinic, “Organ Donation: Don’t Let Myths Stand in Your Way,” www.mayoclinic.com (cited May 2006). BIBLIOGRAPHY.
Celina Martinez, M.D. Johns Hopkins University
1292 Organ Transplantation
Organ Transplantation Organ transplantation involves the surgical removal of an organ from one location to another. This may involve moving organs or part of an organ from one part of a patient to another part, as in the case of a skin graft to repair burn damage. An alternative is to move an organ from one person to another person. Since the organs involved are important to human life, it is quite common for the organ donor to have died prior to the surgery. It is generally desirable for young and healthy organs to be used for transplant and so the use of donor cards granting permission to doctors to harvest organs in the event of sudden death has become widespread. In developed countries, improvements in road safety have significantly decreased the supply of young deceased donors, which had been a principal source of organs, thereby requiring alternative arrangements to be put in place. A third type of transplant involves two genetically similar individuals, such as may exist among close family members. Transplant operations in this case reduce the chance of rejection of the transplanted organ, since it has a similar genetic profile to that being replaced. Rejection has been one of the most common causes of failure in organ transplantation since the first operations were successfully completed. Family membership might also prove an incentive to give up the organ in the case where this could be painful or deleterious to long-term health. It is also possible that some transplants might take place across species, whether humans are involved or not. This provokes moral as well as technical debate. Although the concept of organ transplantation is not a new one, it is only since the second half of the twentieth century that it could be effected successfully. Complex technical issues relating to the sheer number and size of connectors between organs and neighbouring tissue defeated non-sophisticated forms of surgery, while the difficulties of keeping the patient alive while an organ is removed and replaced should also not be minimized. Even when these issues were successfully achieved, the issue of rejection and inflammations also needed to be addressed. Bodies naturally wish to reject tissue, which is perceived not to be innate to it, and particles are formed in the blood stream to attempt to counter its intrusion. Consequently, the patient will require considerable additional medication to try to en-
sure that this does not occur. The breakthrough event in organ transplantation was the work of Dr Christiaan Barnard in heart transplantation in 1967. This was the technical consummation of work begun in 1905 in suturing by a team led by Alexis Carrel and Charles Guthrie in Chicago. Since then, heart transplants have been accompanied by lung transplants, kidney and liver transplants and, in recent years, by complete face transplants. Kidney transplants, facilitated by dialysis involving an artificial external kidney, has become almost a routine procedure, given access to a suitable donor organ. As surgical and medical techniques continue to develop, the scope for organ transplantation will also increase. Attention within some areas of research has started to focus on the possibility of growing or creating organs from stem cells or the use of full of partial clones as potential organ donors. Many people believe that ethical considerations should also be taken into account in these cases in addition to the technical issues. Consequently, it is necessary for society to engage in an informed and coherent debate about the type and nature of such medical advances that it is desirable to permit. Debate should also concern the potential and actual commercial market for organ sale. Numerous anecdotes and a smaller amount of hard evidence surrounds the possibility of mostly poor people selling organs to mostly richer people for financial gain. The nature of informed consent will need to be re-examined in these cases. SEE ALSO: Organ Donation; Surgery. BIBLIOGRAPHY. Ronald Munson, Raising the Dead: Organ
Transplants, Ethics, and Society (Oxford University Press, 2004); Linda Bren, “Keeping Human Tissue Transplants Safe,” FDA Consumer Magazine (v.39/3, 2005).
John Walsh Shinawatra University
Orthomolecular Medicine Orthomolecular medicine, a distinct branch of complementary and alternative medicine, is defined as the treatment of disease by the provision of the optimum
Orthomolecular Medicine
molecular environment, especially the optimum concentrations of substances normally present in the human body or as the preservation of good health and the treatment of disease by varying the concentrations in the human body of substances that are normally present in the body and are required for health. Proponents of orthomolecular medicine argue that typical diets are inadequate or insufficient for optimal health. Thus, patients are often given supplemental doses of agents found in food. Practitioners of orthomolecular medicine most frequently prescribe oral regimens of vitamins, minerals, amino acids, fatty acids, and other naturally occurring substances to treat and prevent disease. Other therapies used include essential fatty acids, fiber supplements, enzymes, antibodies, antigens, cell therapy, chelation therapy, dialysis, plasmapharesis, as well as other conventional and nonconventional physical and psychotherapies. Most commonly, nutrients are supplemented in oral form, generally well in excess of recommended daily allowances. Besides compensation for a deficient diet, orthomolecular practitioners base their use on increased nutritional requirements due to disease, medication use, stress, environmental factors, biochemical individuality, as well as direct pharmacological effects of nutritional supplementation. Various standard and nonstandard laboratory analyses are often used to guide treatment, including those for amino acids, organic acids, vitamins and minerals, functional vitamin status, hormones, immunology, microbiology, and gastrointestinal function. The word orthomolecular was first used by Linus Pauling, quantum chemist and biochemist, in 1968 to express the idea of the right molecules in the right amounts within the context of psychiatry. Since then, the orthomolecular field has diversified, but the term is still often closely associated with Pauling’s advocacy of multigram doses of vitamin C for optimal health. Partly for this reason, detractors of orthomolecular ideas have described them entirely in terms of megadose nutrient therapy. Practice Among the cardinal rules of orthomolecular medicine are the following: • Nutrition comes first in medical diagnosis and treatment.
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• Drug treatment is used only for specific indications and always with an eye to the potential dangers and adverse effects. • Environmental pollution and food adulteration are an inescapable fact of modern life and are a medical priority. • Biochemical individuality is the norm in medical practice; therefore, stereotyped recommended daily allowance (RDA) values are unreliable nutrient guides. • Blood tests do not necessarily reflect tissue levels of nutrients. • Nutrient diagnosis is always defensible because nutrient-related disorders are usually treatment responsive or curable. These cardinal rules are based on principles that posit, among other things, that orthomolecules have a low risk of toxicity, biochemical needs change, nutrient-related disorders are generally treatable and deficiencies are usually curable. Nonconventional treatment is prescribed on the notion that when a treatment is known to be safe and possibly effective, as is the case in much orthomolecular therapy, a therapeutic trial is mandated. Consistent with the World Health Organization (WHO), orthomolecular practitioners acknowledge that health is not merely the absence of disease, but the positive attainment of optimal function and well-being. Popularity A 2004 survey by the U. S. National Institutes of Health (NIH) found that 2.8 percent of the U.S. population used megavitamin therapy, ranking it 12th among complementary and alternative medicine practices. Among the most popular orthomolecular treatments are the use of supplemental vitamins—B vitamins, vitamin C, vitamin E, minerals such as chromium, selenium, calcium, and magnesium, and others such as omega-3 fatty acids, glucosamine, and digestive enzymes. Controversy Detractors argue that limited scientific evidence supports the use of nutritional supplements to treat disease which results in futile treatments that may be toxic or harmful when used in place of proven treatments.
1294 Orthopedics J. Goodwin and M. Tangum argue that throughout the 20th century, American academic medicine has resisted the concept that supplementation with micronutrients might have health benefits. This resistance is demonstrated by the uncritical acceptance of news of toxicity, by the angry and scornful tone used in discussions of micronutrient supplementation in the leading textbooks of medicine, and by ignoring evidence of possible efficacy. SEE ALSO: Alternative Medicine; Homeopathy; Pauling,
Linus; Vitamin and Mineral Supplements.
BIBLIOGRAPHY. P. Barnes, et al., CDC Advance Data Report
#343. Complementary and Alternative Medicine Use Among Adults: United States, 2002 (Centers for Disease Control and Prevention, 2004); S. Barrett, “Orthomolecular Therapy,” http://www.quackwatch.org/01QuackeryRelatedTopics/ ortho.html (cited July 2007); J. S. Goodwin and M. R. Tangum, Battling Quackery: Attitudes about Micronutrient Supplements in American Academic Medicine,” Archives of Internal Medicine (v.158, 1998); S. Lawson, “What Is Orthomolecular Medicine?” The Linus Pauling Institute at Oregon State University, http://lpi.oregonstate.edu/f-w99/ orthomolecular.html (cited July 2007); R. A. Kunin, “Principles that Identify Orthomolecular Medicine: A Unique Medical Specialty,” http://orthomed.org/kunin.html (cited July 2007); L. Pauling, “Orthomolecular Psychiatry. Varying the Concentrations of Substances Normally Present in the Human Body May Control Mental Disease,” Science (v.160/825, 1968); World Health Organization, “Constitution of the World Health Organization, Geneva, 1946,” http://www.yale.edu/lawweb/avalon/decade/decad051. htm (cited July 2007). Ather Ali, ND, MPH Yale Prevention Research Center Yale School of Medicine
Orthopedics Orthopedics is the branch of medicine concerned with disorders of the musculoskeletal system. It is a broad field dealing not only with the vast array of congenital, traumatic, cancerous, or degenerative processes afflicting bones and joints, but also those
of muscles, tendons, nerves and vessels. Orthopedics is also varied in the treatment modalities it employs. While it is generally a surgically oriented specialty, medical management, external stabilization, and rehabilitation therapy are all invaluable non-operative tools in achieving the goal of preserving and restoring function of the trunk and limbs. It would be hard to overstate the impact that musculoskeletal conditions have on the lives of people affected by them. Orthopedic complaints are the most common reason for seeking medical care, accounting for 131 million office visits per year. Arthritis is the leading cause of disability, while osteoporosis is responsible for 1.3 million fractures every year. Approximately 80 percent of all people will experience some form of back pain in their lifetime. In addition to the loss of function so many individuals suffer at home, work or at play due to loss of mobility or pain, there is an economic toll: musculoskeletal conditions cost the United States economy more than $215 billion a year, and their impact will only grow as the population increases and ages. Related to the importance of orthopedics is its antiquity. It is arguably the oldest medical field, with evidence of treated fractures from pre-history. However, it was first described as a specialized branch of medicine by Nicholas Andre in 1741. He coined the term “orthopaedia” by combining the Greek terms “orthos” (straight, free of deformity) and “paidios” (child). He proposed that preventing deformity and disability in adults could be accomplished by correcting those of children. As a surgical field, however, orthopedics could only blossom with the advent of modern technologies, such as anesthesia and aseptic technique for operating, and x-ray for diagnosis. Orthopedics was once constrained to emergent (and often fatal) surgery, reducing fractures, reducing dislocations with traction, and treating childhood deformities with bracing, but now includes joint reconstruction, sports medicine, hand surgery, foot and ankle, disorders of the spine, pediatric orthopedics, musculoskeletal trauma, and orthopedic oncology. Even in this day of sophisticated surgical technique, pediatric orthopedics still to a large degree uses splinting and bracing techniques Nicholas Andre might recognize in an effort to develop “straight children.” For example, congenitally inwardly-bent feet, or club-foot (talipes equinoarus), is corrected by
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gradual straightening via a series of casts. This is done before the child can walk, which avoids progressive and debilitating deformity and ulceration that result if club-foot is left uncorrected. Motor vehicle, sports, and occupational accidents keep emergency rooms busy, and muskuloskeletal trauma is the realm of the orthopedists. There is an astounding variety of fractures, dislocations and tears, and an equal variety in treatment strategy. Fractures must be immobilized to allow bones to mend and the simple yet effective cast is a familiar treatment. However, not all fractures are alike. Surgery is necessary if blood vessels or nerves have been damaged, or if the skin has been breeched by the fractured bone. Orthopedists must also be able to mange and reduce the complications of immobilization such as blood clots and pressure sores. Plates, screws and other fixation devices can reduce stiffness and atrophy associated with casting by allowing early mobility. In the case of femur fractures, a rod is often placed through the center of the bone to provide stabilization during the healing process. Plates and screws are also indicated in repairing flat bones, such as those in the skull, or to address various spinal pathologies. Arthritis causes significant discomfort and disability. Osteoarthritis is very common and is due to the wearing down of articular cartilage, allowing bones to rub against each other, resulting in pain and stiffness. Rheumatoid arthritis, Lupus and ankylosing spondylitis are all chronic and systemic diseases that cause
inflammatory destruction of joints. Medical management is often sufficient (and necessary), but total joint replacement surgery offers excellent symptomatic and functional improvement in seriously affected joints. Hip arthroplasty involves the removal of the degenerated joint and implantation of a prosthetic made of either plastic, metal, ceramics of a combination thereof. Total hip replacement, as it is often called, was first performed in 1960 and 193,000 procedures are now performed every year. Such surgery restores mobility, reduces pain, and studies have shown that dollar for dollar, it improves quality of life as much as coronary artery bypass graft surgery. Similar replacement surgeries are also performed on knees, shoulders and elbows. Caring for sports-related injuries is an important part of the Orthopedic field. Athletic endeavors, be they at the level of the school-aged child, elite athlete or recreational adult level, place the musculoskeletal system at increased risk. Orthopedists must treat a wide variety of injuries, recognizing that there is variation according to the demands of individual sports as well as with the physical characteristics of age and gender groups. For example, runners experience more than their fair share of over-use injuries like stress fractures in the foot, while baseball pitchers suffer from damage to the rotator cuff in the shoulder. Both men and women tear their anterior cruciate ligament in their knee, but women suffer up to 10 times as many as men. Athletes also differ from the general population in their expectations of performance and recovery time. Improved surgical technique and specialized rehabilitation can now often restore levels of function to elite athletes. Arthroscopy is the technique of inserting surgical instruments and cameras into a joint space in order to operate without large incisions. It is less invasive than open procedures and minimizes trauma to adjacent structures. Arthroscopy has revolutionized the treatment of the athlete, satisfying the desire for faster recovery with less pain and often better ultimate performance. Of course, non-athletes appreciate these benefits as well. In addition, minimally-invasive endoscopic and image-guided techniques are also utilized by the Orthopedic surgeon in the surgical treatment of various spine conditions. Orthopedic surgery is a crucial component in the treatment of tumors of the bone. Benign tumors do
Orthopedics is the branch of medicine concerned with disorders of the musculoskeletal system.
1296 Orthopedist not spread to other parts of the body, but can compromise function, be painful or unsightly, and are excised depending on circumstances. Surgical resection is often combined with radiation and chemotherapy to treat tumors like Ewing’s sarcoma or osteosarcoma, which are malignant tumors that grow rapidly and metastasize. The multidisciplinary approach to treatment means the orthopedic surgeon works in conjunction with oncologists. Orthopedics is a very broad field because of how complex the musculoskeletal system is and how many processes can impair its function. The field is also a rapidly growing and evolving field as new technology continues to provide revolutionary new treatment options. Robotics may provide the next leap in surgical technique, while material sciences improve joint prostheses and stem cells may one day allow regeneration instead of mechanical replacement. Orthopedics will continue to provide new ways of protecting and restoring function. SEE ALSO: American Academy of Orthopedic Surgeons
(AAOS); Arthritis; Cancer (General); Carpal Tunnel Syndrome; Cervical Spine; Down Syndrome; National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS); Orthopedist; Osteoarthritis; Osteogenesis Imperfecta; Osteoporosis; Rheumatoid Arthritis; Scoliosis; Spinal Cord Injuries; Spinal Stenosis; Sports Injuries; Surgery. BIBLIOGRAPHY. American Academy of Orthopedic Sur-
geons, www.aaos.org (cited October 2006); John D. Heckman, Animesh Agarwal, and Robert C. Schenck, Current Orthopedic Diagnosis & Treatment (McGraw-Hill, 2006) Elliot P. Robinson University of Virginia Dino Samartzis, DSc, MSc, Dip. EBHC Harvard University and Erasmus University, Francis H. Shen, MD University of Virginia,
Orthopedist An orthopedist is a physician who practices in the field of orthopedics, which is the branch of medicine
concerned with disorders of the musculoskeletal system. The word “Orthopedics” comes from the Greek words “orthos”, meaning “straight”, and “paedia” meaning “child,” which describes one of the orthopedist’s earliest specialties: straightening the curved spines of children with scoliosis. Bracing, reduction of fractures and dislocations, and casting was and is the bread-and butter of the orthopedist. However, orthopedists are now often referred to as orthopedic surgeons, which is a role attributed to the advancement of surgical techniques and instrumentation that have facilitated the treatment of a wider variety of congenital, traumatic, cancerous, or degenerative processes afflicting bones and joints as well as those of muscles, tendons, nerves, and blood vessels. An orthopedic surgeon is a medical doctor who has completed five or more years of a residency training program in orthopedic surgery and has obtained state and national licensure. One to two-year fellowships offer advanced training in specialty areas, such as hand, spine, pediatric, total joint reconstruction, musculoskeletal oncology, and foot and ankle surgery. According to the Unites States Department of Labor, approximately three to four percent of all physicians are specialized in orthopedic surgery. Over 50 percent of orthopedic surgeons practice general orthopedics, while 11 percent practice spinal surgery, 10 percent practice sports medicine, and the remaining specialize in other sub-specialties. The field of orthopedic surgery requires dexterity as well as some degree of physical strength and stamina. However, in addition to technical ability, the orthopedist must be able to inform and guide patients in making decisions about their care that have lasting impact on their mobility, function, and ultimately their quality of life. SEE ALSO: American Academy of Orthopedic Surgeons
(AAOS); Arthritis; Cervical Spine; Down Syndrome; National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS); Orthopedics; Osteoarthritis; Osteogenesis Imperfecta; Osteoporosis; Rheumatoid Arthritis; Scoliosis; Spinal Cord Injuries. BIBLIOGRAPHY. American Academy of Orthopedic Sur-
geons, www.aaos.org (cited October 2006); John D. Heckman, Animesh Agarwal, and Robert C. Schenck, Current
Osteoarthritis
Orthopedic Diagnosis & Treatment (McGraw-Hill, New York, 2006) Elliot P. Robinson University of Virginia Dino Samartzis, DSc, MSc, Dip. EBHC Harvard University and Erasmus University Francis H. Shen, MD University of Virginia
Osler, Sir William (1849–1919) Born on July 12, 1849, in what is now Ontario, Canada, Sir William Osler revolutionized the instruction of medical students in the United States, and he served as the first physician-in-chief of the Johns Hopkins Hospital. An expert in heart, lung, and blood diseases, he strongly influenced the direction of modern medicine. Initially intending to enter the ministry, Osler studied for one year at Trinity College in Ontario in 1867; intrigued by medicine, he transferred to the Toronto Medical College and then to McGill University in Montreal, where he received his M.D. in 1872. He then studied in England, Germany, and Italy for two years, returning to begin teaching at McGill University. In 1883, Osler was accepted into the British Royal College of Physicians, one of only two Canadians elected. The following year, he moved to the United States, where he served as professor of clinical medicine at the University of Pennsylvania. In 1888, Osler was selected as the chief physician of the Johns Hopkins Hospital and as a professor for the complementary medical school. As the second professor officially selected for the medical school, Osler combined the best of what he learned in the countries where he had studied, instructing students by the beds of patients. He placed strong emphasis on the bacteriological laboratory and encouraged significant mandatory postgraduate training. Osler published The Principles and Practice of Medicine in 1892, a text that was considered the premier medical instruction for the next four decades. This book was translated into French, Ger-
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man, Spanish, and Chinese, and focused on both physiological and psychological causes and treatments of disease. John D. Rockefeller so appreciated this book that it increased his interest in medical research; the Rockefeller family later created the Rockefeller Institute of Medical Research. In 1905, Osler accepted the Regius Professorship of Medicine at Oxford University, serving in this capacity for the rest of his life. In 1911, he was dubbed a baronet. He died on December 29, 1919, in Oxford, England. SEE ALSO: Disease Prevention; Primary Care. BIBLIOGRAPHY. Nancy McCall, ed., The Portrait Collec-
tion of Johns Hopkins Medicine: A Catalog of Paintings and Photographs at the Johns Hopkins University School of Medicine and the Johns Hopkins Hospital, http://www.medicalarchives.jhmi.edu/osler/biography.htm (cited July 2007); “William Osler,” in McGill Medical Luminaries, ed. Edward H. Bensley, http://www.mcgill.ca/osler-library/collections/ special/osler/ (cited July 2007). Kelly Boyer Sagert Independent Scholar
Osteoarthritis Osteoarthritis, also known as degenerative joint disease, is the most common form of arthritis and a leading cause of disability worldwide. The incidence of osteoarthritis increases with age, and disproportionately affects women. Individuals younger than 55 years of age have an equal distribution of affected joints regardless of gender; in older individuals, hip osteoarthritis is more common in men. Racial differences exist in the incidence of hip osteoarthritis as well with a greater incidence in whites as compared to the Hong Kong Chinese, for example. The risk for disability as a result of osteoarthritis is as great as that attributable to cardiovascular disease. The primary physical effects of osteoarthritis are the symptoms of pain. The joint pain of osteoarthritis is described as a deep aching sensation present in the involved joint. Generally, movement of the involved
1298 Osteoarthritis joint provokes the pain which will be relieved by rest. With progression of the disease, the pain may become persistent. Such advanced disease may be responsible for nocturnal pain and sleep interference, particularly in advanced osteoarthritis of the hip. The cause of the pain is generally due to an inflammatory response secondary to damaged tissue. The foremost feature of osteoarthritis is the progressive erosion of articular cartilage. The cartilage will become soft, frayed, and progressively thinned. Eventually, the exposed bone (subchondral) will convert to a more dense substance with a smooth surface, a process known as eburnation. Simultaneously, there will be bony protuberant outgrowths, known as osteophytes, from the bone margins, ultimately leading to pain and loss of function as a result. The joint destruction may become significant enough to lead to joint incongruity. Osteoarthritis mainly affects weight-bearing joints, and is more common in overweight and older persons. While the most prominent of the changes take place in the load-bearing areas of the cartilage, smaller joints may be affected that may not have served as predominant load-absorbing joints. It was previously believed that osteoarthritis involved only the joint. Research has shown that the disorder is one of the whole joint organ. Gross alterations do take place at a macroscopic level, while the underlying pathology is now known to involve the synovium, capsule, and the bone beneath the cartilage as much as the cartilage itself. The progression of scientific understanding has changed the view of osteoarthritis as solely representing a wear and tear of damaged and overused joints. Changes in understanding have led to a shift in the paradigm of osteoarthritis which was once seen only as a passive, degenerative disorder for which little can be done. The realization that osteoarthritis is driven by an active disease process of the joint that can be modified by both mechanical and biochemical manipulations will undoubtedly improve the quality of life of patients suffering from the disease. The metabolically active role of the disease process is now recognized. Research suggests that it may be possible to arrest the progress of and, potentially, even reverse the disease. The reasons for differing subjective measures of pain levels by individual patients with similar conditions are still unknown. In addition, there are often no parallels between symptoms and clinical signs of osteoarthritis
and the presence of radiographic signs of osteoarthritis. At present, there is no specific or universally applicable criterion by which to measure the impact of osteoarthritis. Numerous sources give estimates of the prevalence of arthritis, prevalence estimates of arthritis range from as low as 6 percent of the adult population in the United States to as high as 90 percent of the population over age 40. Etiology Osteoarthritis usually occurs in a weight-bearing joint, which has previously experienced trauma, infection, or injury, and results from deterioration or loss of the articular cartilage, a smooth fibrous connective tissue that acts as a shock-absorbing cushion between bones. Osteoarthritis was previously considered to be primarily a degenerative disorder and an ordinary occurrence of wear and tear on joints as a result of aging. Recent discoveries about the role played by specific proteins and enzymes have improved understanding of the mechanisms by which cartilage undergoes changes in arthritis. These developments may potentially lead to diagnostic procedures and treatment modalities that prevent disease progression or even reverse the damage. Osteoarthritis is characterized by tissue repair as well as the typical destruction that results in pain and disability. However, the process of this repair is still unknown. Many of the radiographic and clinical features of the disease that are observed are secondary to attempted repair by the damaged joint. As a result, the belief that osteoarthritis is an inevitable result of a lifetime of joint use is becoming less accepted. In addition, several distinguishing and noteworthy differences between aging joints and those found in osteoarthritis support these theories. For example, the organic changes in the cells that occur with osteoarthritis result in marked physical, chemical, and synthetic changes, while examination of the aging joint at a microscopic level does not reveal these changes. The water content in cartilage of the aging joint does not undergo appreciable change, while the water content of cartilage in joints affected by osteoarthritis is noted to increase early in the disease process. As was noted earlier, the subchondral bone changes associated with osteoarthritis are not seen in the aging joint. Current evidence continues to demonstrate that regular to moderate use of normal joints does not in-
crease the risk for osteoarthritis. An appropriate level of activity is important to maintain overall health and preserve muscle strength and range of motion. Diagnosis Patients with osteoarthritis generally complain of subtle throbbing arthralgias (pain in the joint, not of an inflammatory nature) with activity. Initially, resting relieves the pain. Eventually, the pain occurs even at rest. Morning stiffness, which usually lasts less than 30 minutes, may also be experienced in the joint. Alternating joint swelling may be noted as well. Early in the disease process, physical examination findings may include any number of symptoms. The joints may appear normal on gross examination. If the affected joint involved is weight bearing, the pain may lead to a gait that is commonly referred to as antalgic (a limping walk used to avoid pain). Later in the disease process, physical examination findings will include several signs of disease progression. Visible osteophytes may be noted. The joints may become warm to touch. The joint will eventually demonstrate some form of range-of-motion limitation secondary to the bony restrictions and/or soft tissue contractures are characteristic. Crepitus (noise or vibration produced by rubbing bone or irregular cartilage surfaces together) while testing range of motion is common. Standard radiographs remain the model for the imaging diagnosis of osteoarthritis. The diagnosis can be made with a high degree of assurance when joint narrowing and osteophyte formation are seen. Several radiographic grading systems have been recommended by various authors, but no single system is satisfactory in the evaluation of osteoarthritis at all joints. SEE ALSO: Hip Injuries and Disorders; Shoulder Injury
and Disorders; Wrist/Arm Injuries and Disorders.
BIBLIOGRAPHY. D. Hamerman, “The Biology of Osteoar-
thritis,” New England Journal of Medicine (v.320/20, 1989); Dennis L. Kasper, et al., Harrison’s Principles of Internal Medicine, 16th ed. (McGraw-Hill, 2005); Robert A. Novelline, Squires Fundamentals of Radiology, 6th ed. (Harvard University Press, 2004); Gregory Scott Stacy, “Primary Osteoarthritis,” www.emedicine.com/radio/topic492.htm (cited January 2007); Ego Seeman and Pierre D. Delmas, “Bone Quality—The Material and Structural Basis of Bone
Osteogenesis Imperfecta
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Strength and Fragility,” New England Journal of Medicine (v.354/21, 2006). Donald W. Hohman, Jr. St. George’s University
Osteogenesis Imperfecta Patients with osteogenesis imperfecta (OI), a genetic disorder characterized by bone fragility, suffer from multiple fractures and other skeletal defects. There are four major forms of OI and two rare variants. The mutations causing OI occur in genes coding for type I collagen, the primary protein of bone and other connective tissues. Weak bones and lax joints can result either from a lower quantity of collagen or poor quality collagen. The severity of OI varies greatly among patients even in the same family. Pathophysiology Type I collagen is the most common form of collagen and is located in numerous regions, such as in bone, cartilage, tendons, ligaments, sclera of the eyes, and dermis of the skin. Osteoblasts, bone-forming cells, produce type I collagen extensively. Osteogenesis imperfecta is a disorder of osteoblast function and results in either a quantitative decrease in collagen in mild OI, or abnormal collagen in severe OI. Poor collagen quality yields brittle bone. In the majority of cases, OI results from genetic mutations in the COLIA genes used to encode collagen. Most cases of OI are acquired by autosomal dominant inheritance in which each child of an affected parent has a 50 percent chance of developing OI. The remaining cases arise from spontaneous mutations. Osteogenesis imperfecta occurs worldwide in 1 out of 20,000 births and affects both sexes and all races equally. Fractures tend to occur early in life, but the age when symptoms begin varies widely. Types and Clinical Features Type I OI, the mildest and most common form, presents with an average of 40 fractures before puberty, blue sclerae or whites of the eyes, loose joints, muscle weakness, easy bruising and thin skin, scoliosis, brittle teeth, and a triangular face. Collagen quantity is
1300 Osteogenesis Imperfecta decreased, but structure is normal, so long as bone deformities are absent and patients have normal stature. Furthermore, 50 percent of patients also experience deafness by age 40. Type II OI is the most severe form and is lethal shortly after birth. Newborns have bone deformities and fractures, and their underdeveloped lungs lead to respiratory failure. Collagen is abnormal in structure and insufficient in quantity. In type III OI, collagen is sufficient but abnormal, leading to severe bone deformities. In addition to all of the type I symptoms, patients exhibit on average 100 fractures before puberty, short stature, barrelshaped rib cages, chronic pain, hernias, and respiratory problems. Type IV OI patients have an intermediate phenotype between types I and III in severity. Collagen, like in type III, is sufficient but abnormal. Patients have moderate bone deformities and short stature, but sclerae are normal in color. Types V and VI are rare forms of OI that can be distinguished from type IV under the microscope. Several other disorders, such as Cole-Carpenter syndrome, Bruck syndrome, and idiopathic juvenile osteoporosis, resemble OI but do not have mutations in type I collagen genes. Complications and Prognosis Potential life-threatening complications include brain hemorrhage and basilar skull compression of the brainstem, which can cause severe neurological damage. During surgery, patients with OI are at higher risk of anesthesia complications. Patients also have recurrent respiratory infections and bone infections known as osteomyelitis. The prognosis varies based on the type of OI, but most children live productive lives despite the pain from fractures. Excluding the lethal type II form of OI, the life expectancy for patients is similar to that of healthy individuals. Diagnosis Osteogenesis imperfecta is often diagnosed on physical examination, with family history providing essential information. When suspected, a full-body X-ray scan (skeletal survey) is performed to look for fractures. Bone mineral density scans also show low density. A skin biopsy is taken and analyzed biochemically for collagen content. DNA from blood is analyzed for
mutations in type I collagen genes. Prenatal diagnosis using ultrasound and chorionic villus sampling can also help detect OI. Audiologic examination should also be performed to detect hearing loss. Although child abuse should not be ruled out immediately, OI has a distinctive pattern of fractures on X-rays from abuse. Treatment This genetic disorder has no cure, but treatments encourage functional ability by maximizing mobility and increasing bone mass. Orthopedic surgical procedures are used to correct fractures and scoliosis. One technique used to prevent bone deformities is known as rodding and involves the placement of metal rods along long bones to reinforce them. In addition, dental procedures can correct tooth abnormalities. Physical therapy involves immobilizing fractures with casts, braces, or splints, and this is complemented with pain management. Electrical nerve stimulation, nerve block, and analgesic medications can all relieve pain and improve quality of life. Swimming and water therapy improve muscle strength and flexibility, while wheelchairs offer patients mobility. Proper intake of calcium and vitamin D, coupled with exercise and avoidance of alcohol and tobacco, improves bone strength. Bisphosphonates, a group of drugs promoting bone mineral density, can be given to reduce fracture rates. Education, genetic counseling, and information about support groups are essential. Lifelong care involves a multidisciplinary approach involving surgeons and therapists. SEE ALSO: Bone Health; Bone Mineral Density; Fractures;
National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS); Orthopedics; Orthopedist; Osteoporosis; Scoliosis. BIBLIOGRAPHY. Osteogenesis Imperfecta Foundation,
www.oif.org (cited November 2006); Frank Rauch and Francis Glorieux, “Review: Osteogenesis Imperfecta,” Lancet (v.363, 2004). Anjan P. Kaushik Francis H. Shen, M.D. University of Virginia Dino Samartzis, D.Sc., M.Sc., Dip. EBHC Harvard University and Erasmus University
Osteonecrosis
Osteology Osteology is the scientific study of bones, especially human bones. The word osteology derives from the Greek for bones, and the term was first used in 1670. Although connected with medicine, osteology is also connected with the fields of archaeology and anthropology, whereby scientists who study osteology help with the identification of human remains by forensic pathology for criminal investigations, and also older bones to provide information for archaeologists and anthropologists in paleodemography. The use of osteology involves an analysis which generally starts with the location of a skeleton or bones. Then, scientists list an inventory of the skeletal elements present. The next part of the analysis involves tabulating a dental inventory, and then working on aging data based on epiphyseal fusion, dental eruption, and tooth wear. The bone morphology then helps determine the sex of the body and also, if possible, the stature of the person, his or her race, and other traits, and then trying to establish the cause of death. Osteology has been used over many years to identify bones from many historical crime scenes. One of the most well-known cases in Britain involved the identification of bones found in a casket hidden at the remains of Shaftesbury Abbey in 1931—the abbey having been destroyed during the Dissolution of the Monasteries in the 1540s. It was immediately suggested that these bones belonged to King Edward the Martyr who was murdered in 978 and whose bones were originally interred behind the high altar at the abbey. In 1962, the owner of the site, Wilson Claridge went to see Thomas E. A. Stowell, a prominent consulting surgeon who specialized in sports injuries. Stowell examined the bones and reached a conclusion about their age and then the age of the person who died. Examining the damage to the bones, he was also able to conjecture as to the injuries that might have caused the death, and concluded that they were consistent with a teenager who could have been stabbed and then dragged from a horse as had happened to King Edward the Martyr. However, the evidence was not enough to convince some historians who still query whether the bones are those of the only English king to be canonized, with the result that they were
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interred at the Russian Orthodox Church in Brookwood Cemetery, near London. A more recent example of the work of osteology was when bones were found near Yekaterinberg (Sverdlovsk) in Siberia, where Czar Nicholas II and his family were murdered in 1918. The bones were originally found in 1976, but their discovery remained a secret until the collapse of the Soviet Union. Using osteology, it was possible to work out that the bones were probably those of Nicholas II, his wife Alexandra, and three of their daughters (probably Olga, Tatiana, and Anastasia), but even with the great advances made in osteology, it was not until DNA genetic tests were made that they could be confirmed as being from the Russian imperial family, and they were given a state funeral on July 17, 1998, and reburied in the crypt of the Cathedral of St. Peter and St. Paul in St. Petersburg. Examples of osteology to solve recent criminal cases has also been important with the forensic techniques used by Keith Simpson being described in his book Forty Years of Murder (1981) in which he outlines a number of important successes over his four decades in the field. Another autobiographical account is Jeff Benedict’s No Bone Unturned (2003) about his career as a forensic scientist for the Smithsonian Institute. SEE ALSO: Death and Dying; Forensic Medicine. BIBLIOGRAPHY. W. M. Bass, Human Osteology: A Labo-
ratory and Field Manual, 5th ed. (Missouri Archaeological Society, 2005); Jeff Benedict, No Bone Unturned: The Adventures of a Top Smithsonian Forensic Scientist and the Legal Battle for America’s Oldest Skeletons (HarperCollins, 2003); M. Cox and S. Mays, eds., Human Osteology in Archaeology and Forensic Science (Greenwich Medical Media, 2000). Justin Corfield Geelong Grammar School
Osteonecrosis Osteonecrosis (ON), also called Aseptic Necrosis, Avascular Necrosis (AVN), or Ischemic Necrosis, is a result of inadequate or completely absent blood supply to the bone. The term ‘necrosis’ refers to death
1302 Osteopathy of the tissue; ‘osteo’ classifies the death as that of the bone tissue. The name Aseptic refers to the absence of bacteria; in other words, the bone death is not due to a bacterial infection. Avascular means without blood supply; Ischemic refers to a lack of oxygen, which is supplied to the bone by the blood. To cause ON, an injury or trauma may have cut off the blood supply; the result is a starved bone that may die. Arthritis typically follows. The end of a long bone is the most common site for ON. ON can be debilitating—if the bone at a joint dies or crumbles, the joint itself may cease to function properly; the person may experience mobility issues or severe pain. There are two major classifications of ON. These types are post-traumatic or non-traumatic. Post-traumatic ON may occur after a break or other bone trauma. Non-traumatic ON has other, idiopathic causes. People of all ages are susceptible to ON; however, most often the disorder occurs in a person’s thirties to fifties. There is a juvenile form of ON known as Legg-Calvé-Perthes Disease (LCPD or Perthes). This disease is named after the three physicians who first described its symptoms. Perthes affects about one in twelve hundred children, as young as two years old through teenagers. It affects males most of the time, and is usually seen in one hip rather than both. Also known as avascular necrosis of the femoral head, coxa plana, ischemic necrosis of the hip, and osteochondritis, Perthes is the specific death of the ball joint in the juvenile hip. The underlying cause for non-traumatic Perthes is unknown, but certain populations may have a higher risk of developing it. These populations include Whites, Eskimos, and Asians. Men and women alike are at risk for ON. The cause of ON is idiopathic, meaning it is unknown. Some risk factors may include alcohol use, arthritis, cancer, or bone injury. People in general good health are at only a low risk of developing ON. Generally, the disorder affects people who have some other health problem involving circulation or blood vessels. For example, someone with impaired blood supply to a region of the body is more likely to develop ON in that region than someone who has proper circulation. The most common sites on the body for developing ON are the hips, knees, shoulders, and ankles, in descending order. All types of ON are treated by orthopaedic surgeons except for ON of the Jaw; this type of ON is treated by craniofacial surgeons. It is usually
associated with tooth extractions or use of bisphosphonate-containing drugs. Drugs with bisphosphonate are used in the treatment of osteoporosis. Each year, approximately twenty thousand people are diagnosed with a new case of osteonecrosis in the United States, according to the National Osteonecrosis Foundation and the Center for Osteonecrosis Research and Education. In the United States, the primary federal funding for research in ON comes from the National Institute of Arthritis and Musculoskeletal and Skin Diseases, part of the National Institutes of Health. SEE ALSO: Bone Diseases; Connective Tissue Disorders;
Hand Injuries and Disorders; Head and Brain Injuries; Hip Injuries and Disorders; Leg Injuries and Disorders; Oral Surgeon; Osteology; Osteopathy; Osteoporosis. BIBLIOGRAPHY. John Anthony Herring, M.D., Legg CalvePerthes Disease (American Academy of Orthopaedic Surgeons Monograph Series) (Amer Acad of Orthopaedic Surgeons, 1996); ICON Health Publications, Osteonecrosis: A Medical Dictionary, Bibliography, and Annotated Research Guide to Internet References (Icon Health Publications, 2004); ICON Health Publications, Perthes Disease—A Medical Dictionary, Bibliography, and Annotated Research Guide to Internet References (Icon Health Publications, 2004); Robert E. Marx, Oral & Intravenous BisphosphonateInduced Osteonecrosis of the Jaws: History, Etiology, Prevention, and Treatment (Quinessence Publishing, 2006); Gregory R. Mundy, Bone Remodeling and its Disorders (Taylos & Francis, 1999); James R. Urbaniak and John Paul Jones, Jr., eds., Osteonecrosis: Etiology, Diagnosis, and Treatment (American Academy of Orthopaedic Surgeons, 1997).
Claudia Winograd University of Illinois
Osteopathy Osteopathy is a system of medicine that is distinct in a philosophical approach to patient care in health and in sickness. Doctors of osteopathic medicine (DOs) are fully-recognized physicians licensed to practice medicine in any of the recognized specialties in the United States and in Canada, as well as some other
countries of the world. Osteopathic practitioners in other parts of the world may or may not be physicians, but they also adhere to a patient-centered approach that utilizes osteopathic manipulation. Osteopathy began in the middle of the United States in the State of Missouri by an itinerant physician, Andrew Taylor Still. Dr. Still was trained under the then-common system of apprenticeship and was licensed to practice medicine. He became increasingly discouraged with the ways in which typical allopathic medicine was practiced in the mid-19th century: lack of antisepsis; amputations; bloodletting; alcohol, opiate, heavy metal, and other dangerous medications; disease-focused treatments; and other unproven interventions. Dr. Still first expressed his frustrations and made a break from traditional medical practice on June 22, 1874, after having experienced personal losses with the deaths of several of his children and his first wife to disease. He reasoned that physicians should focus on the patient and facilitate the inherent adaptive, self-healing, and defensive mechanisms of the individual. Eschewing the typical approaches, his chief tool to accomplish his medical interventions was the use of manipulative techniques. By 1892, he had such success that he established a medical school, the American School of Osteopathy, in Kirksville, Missouri. Among his first students were former patients, family members, and allopathic physicians who were also frustrated with the typical heroic medical practices of the day. Dr. Still was permitted to grant an MD degree under the school’s original charter that was granted by the State of Missouri, but he wanted to break with traditional practices, and so he chose to name his new approach “osteopathy” or osteopathic medicine. Because manipulation was to be the primary tool, practitioners would have a “feeling for the bone.” Five women were among the inaugural class of students at his two-room building. The number of students and the physical size of the school rapidly grew as well as the number of schools developed by his followers. The initial satellites were established primarily throughout the Midwest of the United States and included colleges established in major cities such as Los Angeles, Des Moines, Kansas City, Philadelphia, and Chicago. An early graduate, J. Martin Littlejohn, returned to his native United Kingdom and established osteopathy in England. From there, it spread to the
Osteopathy
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European continent, although it was primarily practiced by nonphysicians there. The philosophical principles of osteopathy, although clarified over the last 100 years, have remained mostly unchanged: I. Structure and Function are interrelated A. Normal 1. Structure governs Function 2. Function modifies Structure B. Abnormal 1. Abnormal Structure results in Abnormal Function 2. Abnormal Function results in Abnormal Structure II. The Person (Body) is a Unit and is composed of an A. Interaction of different systems 1. Neurological 2. Dermatological 3. Musculoskeletal 4. Hematological 5. Cardiovascular 6. Pulmonary 7. Gastrointestinal 8. Genitourinary 9. Endocrine 10. Immunological 11. Behavioral/Psychological B. Mind, Body, Spirit connections 1. All of the components interact and influence each other 2. There is sometimes difficulty separating what is cause or effect III. The body has an inherent ability to A. Regulate itself 1. Normal a. Maintain systems 2. Abnormal a.Altered regulation B. Adapt to changes that occur 1. Normal a. React to small alterations in environments • External • Internal 2. Abnormal a. Poor adaptation
1304 Osteopathy b. Inappropriate reaction C. Compensate when regulation and adaptation cannot occur or inadequately occur: 1. To inherent or developed inadequacies a.Normal • Congenital malformations • Genetic • Functional inadequacies b.Abnormal • Overcompensation • Undercompensation • Maintenance of adaptation past usefulness D. Repair itself when damaged 1. Normal a. Tissue repair 2. Abnormal a. Scar formations b. Adhesions E. Defend against dangers from within and without 1. Normal a. Internal derangements • Abnormal cell formation (i.e., cancerous cells) a. External invasions 2. Abnormal a. Inappropriate reaction to irritants • Recognition of host elements as “enemy” (i.e., autoimmune disease) IV. Disease/Dysfunction of the body A. Is the interaction of the 1. Host (person) 2. Activating event a. Endogenous b. Exogenous B. Disease occurs when the body is 1. Overwhelmed 2. Underprepared V. Rational treatment is based on the above principles A. Treatment decision is based on proper 1. History 2. Examination 3. Experience 4. Knowledge B. The function of the physician is to 1. Facilitate the body’s inherent capacities
2. Minimize effects of disease a. Endogenous alterations b. Exogenous threats Osteopathy was not immediately accepted within the United States and was often referred to as a cult and its practitioners as “quacks.” Although several American presidents, politicians, writers, artists, and others were supporters, legislation permitting the practice as physicians was slow in evolving. Early reviews supported by the American Medical Association (AMA) and other entities, such as the Flexner report, indicated that the osteopathic medical schools were deficient because of the relative dearth of pharmacology, or material medica as it was called in the late 19th and early 20th centuries, that was taught. Although the curriculum initially included surgery and obstetrics, Dr. Still limited the amount of pharmacology that was taught. He exhorted his followers to “keep it pure.” However, shortly after his death in 1917, the curriculum at the surviving osteopathic medical schools developed ways to meet the requirements that were perceived as deficient. Gradually, the requirements and duration of the curriculum matched that of the typical MD medical schools. The road to acceptance of the “parallel and distinctive” osteopathic medical profession was often rocky. In early times, some osteopathic physicians were prosecuted for illegally practicing medicine, sometimes successfully. Regulations initiated to secure recognition in the armed services occurred in the early part of the 20th century, but it was not until the mid-1960s that DOs were commissioned as officer physicians. Lack of hospital privileges and exclusionary directives from the AMA barring MDs from cooperating with osteopaths in any manner further limited training and practice opportunities. However, by the late 1950s, DOs had established their own hospitals and the AMA had dropped its objections to the recognition of DOs as physicians, if they rejected adherence to their historical and philosophical roots. The California Medical Association and the California Osteopathic Association entered into secret negotiations. Legislation was introduced in that state to allow the licensed osteopathic physicians to attend a weekend seminar, pay a $65 fee, and exchange their DO degrees for state-granted MD diplomas. Over 2,000 DOs took this option. Simultaneously, the two
Osteoporosis
medical societies merged and the College of Osteopathic Physicians and Surgeons converted to a state college of allopathic medicine. Students who entered anticipating graduating with a DO degree would become MDs. The legislation also restricted licensing any new osteopathic physicians within the state and would eliminate the osteopathic medical board once the absolute number of licensed DOs fell below a specified number. Rather than being the beginning of a nationwide series of assimilations, this event became the rallying nexus for maintaining a separate medical profession. Many of the remaining DOs within California who objected to the transition formed a core group which fought for restoration. The legislation was determined to be unconstitutional in 1974 and a new college of osteopathic medicine was established by the end of that decade. Gradually, the number of osteopathic medical schools and graduates increased from the initial few to 25 in 2007 and nearly 60,000 osteopathic physicians in practice in the United States. Many practice alongside MDs as well as obtain their pre- and postgraduate training in the same hospital settings. It is sometimes difficult to see the distinction between the two types of physician practitioners. Some do not look upon themselves as different. The curricular difference in the schools continues: all osteopathic students are instructed in osteopathic principles, philosophy, and practices. MD physicians of the current era apparently have no stated objection to the philosophy although some concerns may persist as to the practice of manipulation. Some of the reluctance may be with a relative lack of evidence as to the benefit and some may still have concerns as to the safety. Primarily, as a therapeutic intervention, manipulation is known to be safe. SEE ALSO: Allopathy; Homeopathy; Naturopathy. BILIOGRAPHY. T. S. Carey, et al., “Do Osteopathic Physi-
cians Differ in Patient Interaction from Allopathic Physicians? An Empirically Derived Approach,” Journal of the American Osteopathic Association (v.103, 2003); E. L. DiGiovanna, An Encyclopedia of Osteopathy (American Academy of Osteopathy, 2001); D. J. Dowling, “The 2005 T. L. Northup Lecture: What If,” American Association of Osteopathy Journal (v.16/1, 2006); D. J. Dowling and D. J. Martinke, “The Philosophy of Osteopathic Medicine,” in
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E. DiGiovanna, S. Schiowitz, and D. J. Dowling, eds., An Osteopathic Approach to Diagnosis and Treatment, 3rd ed. (Lippincott Williams, & Wilkins, 2004); N. Gevitz, The DOs: Osteopathic Medicine in America, 2nd ed. (Johns Hopkins University Press, 2004); N. Gevitz, Other Healers: Unorthodox Medicine in America (Johns Hopkins University Press, 1988); G. D. Hulet, A Text Book of the Principles of Osteopathy, 5th ed. (A.T. Still Research Institute, 1922); E. L. Hurwitz, et al., “Manipulation and Mobilization of the Cervical Spine: A Systematic Review of the Literature,” Spine (v.21/15, 1996); S. M. Johnson and D. Bordinat, “Professional Identity: Key to the Future of the Osteopathic Medical Profession in the United States,” Journal of the American Osteopathic Association (v.98, 1998); J. M. Littlejohn, “The Principle of Osteopathy,” Journal of the American Osteopathic Association (v.100, 2000); B. Peterson, “A Compilation of the Thoughts of George W. Northrup, DO, on the Philosophy of Osteopathic Medicine,” Journal of the American Osteopathic Association (v.98, 1998); M. A. Seffinger, et al., “Osteopathic Philosophy,” in R. C. Ward, ed., Foundations for Osteopathic Medicine, 2nd ed. (Lippincott, Williams & Wilkins, 2003); A. T. Still, “Autobiography of A. T. Still,” in R. E. Truhlar, ed., Doctor A. T. Still in the Living (Privately published by the author, 1950); A. T. Still, The Philosophy and Mechanical Principles of Osteopathy (Hudson-Kimberly, 1902). Dennis J. Dowling, D.O., F.A.A.O. Independent Scholar
Osteoporosis Osteoporosis is bone disease with symptoms including low bone mass and deterioration of bone structure. This can lead to increased risk for bone fractures. Although osteoporosis occurs in both men and women, it occurs more frequently in women. The prevalence is higher in white and Asian women, but it also occurs in African American, Hispanic, American Indian, and Alaskan Native women. Approximately 10 million Americans, 8 million of whom are women, are affected by the disease and these numbers are expected to increase. It contributes to 1.5 million fractures per year, occurring most commonly in the wrist, spine, and hip. Twenty percent of victims of hip fractures die within a year. Another 20 percent will end up in a nursing home
1306 Osteoporosis within a year. The National Osteoporosis Foundation estimated that $18 billion was spent on fractures related to osteoporosis in 2002. Osteoporosis often goes undetected until a fracture occurs, but a diagnosis can be made with a bone mineral density test (BMD). It is recommended that all women over the age of 65 have a yearly BMD test. In addition any postmenopausal woman with two or more risk factors should also have the test. Risk factors include such things as smoking, lack of exercise, and low body mass index. There is no cure, but treatment for osteoporosis involves taking medications which either restore bone formation or help with resorption. Osteoporosis can be prevented through exercise and ensuring proper calcium and vitamin D intake. The recommendations for intake of calcium and vitamin D increase with age. Risk Factors Risk factors include being female, Asian or Caucasian, smoking, a diet low in calcium, excessive alcohol consumption, lack of exercise, estrogen deficiencies in the form of early menopause, amenorrhea for one year, low body mass index, having a small frame, advanced age, vitamin D deficiency, low lifetime calcium intake, anorexia nervosa, use of certain medications, a personal history of fractures after age 50, and a maternal family history of hip fractures. Diagnosis It often goes undetected until a fracture occurs. A bone mass density test (BMD) is recommended for all women over the age of sixty-five and any postmenopausal woman who has one or more other risk factors. The most common way to administer the BMD test is dual energy x-ray absorptiometry. Other methods include quantitative computed tomography and quantitative ultrasound. These tests take five to ten minutes to administer and are safe and painless. Treatment Treatment involves medications which are either antiresorptives, meaning they help with the rate of bone resorption, or anabolic which help with bone formation. Antiresorptives include bisphosphonates such as ibandronate and risedronate. Other medications include calcitonin and estrogen therapy. Anabolic medications include parathyroid hormone treatment. Although these medications do not cure osteoporo-
sis, they do function to help with bone resorption or bone formation. Neil Binkley and Diane Krueger note that medications should be used in conjunction with a comprehensive plan involving such things as proper nutrition (especially vitamin D and calcium), pain and depression management, a physical therapy program, exercise, and minimizing risk of falls. Prevention Osteoporosis can be prevented by exercise and increased calcium intake. In an editorial in the Southern Medical Journal, Ronald Handy describes how this is a health crisis which is being neglected and steps must be taken to prevent and treat it. Maintaining adequate intake of calcium and vitamin D is essential. Adults aged 18–50 years need 1,000 mg/day of calcium and 200 IU/day of vitamin D. Those numbers increase to 1,200 mg/day of calcium and 400 IU/day of vitamin D for individuals aged 51–70. For those over 70 years old, 1,200 mg/day of calcium are needed and 600 IU/ day of vitamin D are needed. In addition, exercise is recommended to aid in prevention of osteoporosis. A recent publication called “Invest in Your Bones: Move It or Lose It,” published by the International Osteoporosis Foundation, stresses the importance of exercise in the prevention of osteoporosis. Specifically, weight bearing exercises such as walking, jogging, or tennis should be done. Not only will exercise help to build and maintain bones, but it will also help prevent falls. Exercise is recommended for everyone from children to the elderly. Because of the fact that most people reach peak bone mass in their 20s, it is vital to start an exercise program at an early age and continue exercising throughout the lifespan. SEE ALSO: Bone Diseases; Bone Health; Calcium; Frac-
tures; Women’s Health (General).
BIBLIOGRAPHY. Neil Binkley and Diane Kreuger, “Cur-
rent Osteoporosis Prevention and Management,” Topics in Geriatric Rehabilitation (v.21/1, 2005); Ronald Hamdy, “Osteoporosis: We Are Neglecting Our Own,” Southern Medical Journal (v.99/5, 2006); International Osteoporosis Foundation, “Invest in Your Bones: Move It or Lose It: How Exercise Helps to Build and Maintain Strong Bones, Prevent Falls and Fractures, and Speed Rehabilitation,” http://www.iofbonehealth.org/download/osteofound/filemanager/publications/pdf (cited October 2006); Interna-
Otolaryngology
tional Osteoporosis Foundation, “Diagnosing Osteoporosis,” http://www.osteofound.org/osteoporosis/diagnosis. html (cited October 2006); Edward Leib, “Bone Mass Measurement Is Emphasized in the Diagnosis—Osteoporosis Diagnosis Redefined: A New Focus on Prevention,” The Journal of Musculoskeletal Medicine (v.22, 2005); National Osteoporosis Foundation, “Medications to Prevent and Treat Osteoporosis,” http://www.nof.org/osteoporosis/faq. htm#MEDICATIONS (cited October, 2006); National Osteoporosis Foundation, “Osteoporosis-Frequently Asked Questions,” http://www.nof.org/osteoporosis/faq.htm (cited October 2006); National Osteoporosis Foundation, “American’s Bone Health: The State of Osteoporosis and Low Bone Mass in the U.S.,” http://www.nof.org/advocacy/ prevalence/ (cited October 2006); National Osteoporosis Foundation, “Fast Facts on Osteoporosis,” http://www.nof. org/osteoporosis/diseasefacts.htm (cited October 2006); United States Department of Health and Human Services, “Bone Health and Osteoporosis: A Surgeon General’s Report,” http://www.surgeongeneral.gov/library/bonehealth/ factsheet1.html (cited September 2006). Amy L. Rowland John Jay College of Criminal Justice
Otolaryngologist A physician who specializes in diagnosing and treating, including surgery, of a variety of disorders of the ear, nose, and throat (ENT). Otolaryngologists’ skills include diagnosing and managing diseases of the sinuses, larynx, oral cavity, and upper pharynx, as well as structures of the neck and face. Otolaryngologists diagnose, treat, and manage specific disorders along with many primary care problems in children and adults. Otolaryngologists offer a very special skill set that is not readily available in the developing world. Most otolaryngologists’ education can last up to 15 years with basic medical education and postgraduate studies. In addition, there is an option for otolaryngologists to pursue a fellowship for more extensive training in one of many subspecialty areas such as in pediatrics or facial reconstructive surgery. This advanced and highly specialized education is not available in many developing nations. Many doctors must leave their home country to pursue such education.
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Otolaryngologists can treat hearing loss, infections, balance disorders, nerve pain in the face, ear, and head, and various other disorders. Otolaryngologists can also treat and manage congenital birth disorders that involve the ear, nose, and throat. In the nose, otolaryngologists treat nasal allergies, sinus infections, and disorders associated with sense of smell. Breathing and appearance of the nose are a major area of management for the otolaryngologist. These disorders may be significant in areas with high air pollution such as crowded urban neighborhoods in the developing world. In the throat, an otolaryngologist is responsible for management and treatment of disorders that would affect speech, eating, and singing. These also include the management of the larynx and the esophagus such as breathing and swallowing disorders that can be life threatening. In the head and neck area, otolaryngologists are able to treat infectious diseases, cancerous tumors, facial trauma, and deformities. This can be in the form of both cosmetic, plastic, and reconstructive surgery. SEE ALSO: American College of Physicians (ACP); Nose
Disorders; Oral Surgeon; Otolaryngology.
BIBLIOGRAPHY. American Academy of Otolaryngology—
Head and Neck Surgery, http://www.entnet.org/ (cited July 2007); Lorri A. Zipperer, ed., The Health Care Almanac: A Resource Guide to the Medical Field (American Medical Association, 1995).. John M. Quinn V, M.P.H. University of Illinois at Chicago
Otolaryngology An otolaryngologist, more commonly known as ENT (Ear, Nose, and Throat) surgeon, is a physician that specializes in the diagnosis and treatment of diseases of the head and neck of both children and adults. More specifically, their special skill includes diagnosing and managing diseases of the sinuses, larynx (voice box), oral cavity, and upper pharynx (mouth and throat) as well as structures of the neck and face. Some ENTs will do further training to spe-
1308 Otolaryngology cialize in a variety of fields, including facial trauma and facial plastic surgery. What do Otolaryngologist Treat? The Ears. The ear is made up of three different sections: the outer ear, the middle ear, and the inner ear. These all work together to hear and process sounds as well as help to keep balance. The outer ear is called the pinna or auricle. This is the part of the ear that is visible externally. The pinna collects sound as well as produces earwax. Cerumen (ear wax) helps fight off infections by helping prevent bacteria from entering the ear canal, and it also traps dirt. Sound waves funnel down the pinna, which opens into the ear canal, where the waves travel to the middle ear. The tympanic membrane (eardrum) separates the ear canal from the middle ear. The job of the middle ear is to take these waves and convert them into vibrations (the malleus, incus, and stapes, which are small middle ear bones, are responsible for this transition) that are delivered to the inner ear. Nerve signals are created here and travel to the brain, which processes these signals as sound. Also, in the inner ear, there are three small loops called semicircular canals, which are responsible for balance. At times, a patient may have inflammation of the inner ear, which can cause severe problems with balance and a sensation of the room spinning (vertigo). The incidence of hearing loss in 2030 is estimated to be 78 Americans million, up from 28 million currently. One possible explanation is the popularity of objects that place speakers close to the ears, such as portable music listening devices and cell phone earpieces. Otolaryngologists excel in prevention, diagnosis, and treatment of such disorders. Their training ranges from medical and surgical treatment of hearing problems, ear infections, balance disorders, ringing ears (tinnitus), nerve pain, facial and cranial nerve disorders as well as congenital (birth) disorders of the outer and inner ear. The Nose. A consultation with an otolaryngologist may be sought in cases of chronic sinusitis (inflammation of the sinus lining membrane), which affects nearly 35 million Americans yearly. If the clinical scenario is severe enough, they may perform sinus surgery if medical intervention has been unsuccessful. They also manage and treat other conditions ranging from allergic rhinitis (inflammation of
the nasal mucous membrane) to breathing defects or even nasal cosmetic concerns, depending on their subspecialty. The Throat. Some historians argue that if George Washington had been treated by an experienced ENT back in December of 1799, he would have survived what turned out to be fatal “inflammatory quinsy.” President Washington was bled approximately four separate times, equaling a total loss of five pints of blood (as was the accepted treatment of the time). Today’s otolaryngologist would be well trained in diagnosing and managing what was most likely a Streptococcus infection leading to tonsillitis. Other diseases of the throat involve communicating (talking, singing, etc.), swallowing, esophageal and upper airway disorders. The Head and Neck. Head trauma is a common cause of hospitalization, especially with children; however it is usually secondary to motor vehicle accidents, sports injuries, or recreation. Otolaryngologists are trained to treat all of the important cranial nerves involved in the control of vision, hearing, smell, and muscles of mastication (chewing) as well as muscles of facial expression. Cancers of the head and neck area are also common and treated by ENTs. Their expertise also extends to treating infectious diseases, facial deformities, and cosmetic and reconstructive surgery. Training of an Otolaryngologist Training consists of about fifteen years of college and postgraduate training. After completion of college, four years of medical school, one or two years of General Surgery followed by three or four years of ENT training, the physician must then pass the American Board of Otolaryngology examination. About 25 percent of all residency graduates take additional fellowship training for more extensive education in one of seven subspecialties. These subspecialty areas are pediatric otolaryngology (children), otology/neurotology (ears, balance, and tinnitus), allergy, facial plastic and reconstructive surgery, head and neck, laryngology (throat), and rhinology (nose). Some otolaryngologists limit their practices to one of these subspecialties. SEE ALSO: Breathing Problems; Common Cold; Head and
Neck Cancer; Noise; Nose Disorders; Respiratory Diseases
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(General); Taste and Smell Disorders; Throat Disorders; Voice Disorders. BIBLIOGRAPHY. American Academy of Allergy, Asthma,
and Immunology, “Allergy Statistics,” http://www.aaaai. org/media/resources/media_kit/allergy_statistics.stm (cited October 2006); American Academy of Otolaryngology—Head and Neck Surgery, “What is An Otolaryngologist?” www.entnet.org (cited October 2006); Kenneth V. Iserson, Iserson’s Getting into a Residency: a Guide for Medical Students (Galen Press, 2003); Robert C. O’Reilly, MD, “Let’s Hear it for the Ear,” http://www.kidshealth. org/kid/body/ear_noSW.html (cited October 2006). Gautam J. Desai, D.O. Nicholas J. Draeger Kansas City University of Medicine and Biosciences College of Osteopathic Medicine
Otology Otology is the field of medicine dedicated to the study and treatment of the ear. In most cases, the original diagnosis of ear problems is performed by primary care physicians such as pediatricians, internists, and family practitioners. In the United States, the infection of the middle ear known as otitis media accounts for half of all visits to pediatricians. With simple infections that respond to antibiotics and with minor injuries, no further care is needed. Referrals are made when conditions are more serious. Otologists work closely with physicians in related fields. Audiologists and asotometrists, for instance, deal with the functional assessment of the auditory system. Oticians serve as hearing aid providers and offer aural rehabilitation. Originally, eye institutions were the only resource for patients that required additional ear care. Once ophthalmologists took on this additional responsibility, they formed hospitals dedicated to treating conditions of the eyes and ears, later adding disorders of the nose and throat. Eventually, otorhinolaryngology became a separate field dedicated to the study and treatment of eyes, and the combination of ear, nose, and throat became a common specialty.
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Although ear disorders have been identified since ancient times, little was understood about the anatomy of the ear or the causes of particular disorders. The Annamites of East India, for example, believed that a tiny animal lived in the ear, generating earwax and serving as a channel for sound. If the animal died, deafness occurred. Even physicians who did not depend on superstition were often in the dark about the causes of ear disorders because the ear is complex and not easily accessible. Treatment was often limited to removing wax and draining fluid that built up around the mastoid bone. Diagnoses were made on a trial-and-error basis. It was not until the rise of experimental science that physicians began to devise treatments based on realities of particular disorders of the ear. The discovery of antibiotics, electronics, and microsurgery transformed the treatment of ear disorders. The existence of a wide range of antibiotics now generally prevents otitis media, the most common ear infection, from developing into acute mastoiditis, as was common in the past. However, many otologists believe that there is a tendency for primary care physicians to over-prescribe antibiotics for ear infections, making them resistant to particular antibiotics. Consequently, persistent infections may require the use of several antibiotics before the most effective one is identified. In the United States, the Healthy People 2010 initiative has identified reducing antibiotic courses for ear infections to 88 courses per 100 children under the age of five as a major goal. Hearing aids in some form or another have been around since the late 16th century. William F. House, the father of neurotology, pioneered surgery techniques that made it possible to safely perform otological surgery. The surgical microscope has been used to develop techniques that allow surgeons to reconstruct the middle ear. One of the most significant medical advances of the 20th century was the discovery that cochlear implants could restore full or partial hearing to large numbers of deaf individuals. This advance has not been without controversy, however, and many within the deaf community have opposed the technology. Advanced research in ontology is now being conducted in the fields of immunology, biochemistry, artificial organs, and microvascular surgery. In the future, otologists hope to solve many of the common disorders of the ear, and one of
1310 Otology the most anticipated advances is the development of a vaccine to prevent otitis media. Disorders of the ear While many people equate earaches and ear infections, they are not synonymous. Common causes of earache not associated with ear infections include Battle’s sign, a condition characterized by bleeding from the ear in response to skull fractures; acute mastoiditis with abscess, accompanied by fever, soft tissue swelling, and tenderness in the ear; scar tissue from previous ear surgeries; temporomandibular joint (TMJ) syndrome, which occurs in the jawbone and radiates to the ear; acute hematoma in which blood collects in the ear; and cauliflower ear, an acquired deformity that is often found in athletes such as wrestlers who suffer frequent severe traumas to the ear. While disorders such as vertigo and tinnitus seem to originate in the ear, they actually have a neurological basis and are generally referred to neurologists. Patients who have otalgia may be referred to dentists. In otological clinical practice, the most common ear-related problems are lacerations, contusions, hematomas, cysts, pierced-ear infections, seborrhea and aural pruritus (a dermatological condition), contact dermatitis, swimmer’s ear, impacted wax, injection of foreign bodies into the ear, fungal infections, exostoses (new bone growing on existing bone), and occasional neoplasms (growths that may be either benign or malignant). Virtually everyone is affected by one or more of these problems at some point in their lives. Nevertheless, many individuals fail to seek help until conditions have failed to respond to home treatment. Some disorders of the ear occur in particular parts of the ear. Problems associated with the outer ear may result from trauma or contact with foreign substances. Injuries may be caused by bludgeons, fists, broken glass, needles, rusty nails, and tooth picks. Infections may be a result of contact with bacteria, allergens, water, fungi, and carcinogens. Although cotton swabs remain popular, common wisdom suggests that no one should ever put anything smaller than an elbow into their ears. The middle ear is much better protected than the outer ear. As a result, traumas and eustachian tube malfunctions are the most common problems in that area. Tympanic perforations are sometimes due to
waves slapping against the head. Skull fractures may also extend to the temporal bone. Problems of the eustachian tube may be as mild as that experienced during aircraft landings or as serious as otitis media. The inner ear is the most protected part of the ear, but it is also the most difficult to examine. Toxic substances that enter the blood and bone may be absorbed into the inner ear and precipitate hearing loss. The auricle of the ear is the projecting structure of the ear that includes the hole through which sound is conducted. Disorders and infections that affect the auricle include acute perichondritis, herpes, Ramsay Hunt syndrome (a virus that attacks the neurological system), relapsing polychondritis, tophaceous gout, and ulcers. Coined by J.E. Veldman, the word otoimmunology refers to the immunology of the ear and its related structures. Systemic diseases that affect the ear are rheumatoid arthritis, lupus, polymyositis, vasuulitis, and relapsing polychodritis. Some otoimmunologic disorders also affect particular parts of the ear. The external ear is affected by relapsing polychondritis, dermatologic conditions, and necrotizing external otitis. The tympanic membranes and the middle ear are more susceptible to myringoplasty, homograft lympano plasty, otos clerosis, acute otitis media, and chronic suppurative otitiis media with cholesteatoma. Autoimmune diseases of the inner ear may be either isolated or syndromal. The latter disorder is known as Cogan’s syndrome, which attacks the inner ear and eye for unknown reasons. Deafness in newborns may be the result of heredity, prematurity, prenatal exposure to harmful substances, infections, trauma, or perinatal events. Low birthweight infants are particularly susceptible to hearing loss, even if they are full-term. Congenital hearing loss may be a result of ossicular fiaxation, ossicular malformation, otresia or stenosis of the external auditory canal. These conditions may exist along with craniofacial abnormalities. Infections, diseases, and trauma are linked with hearing loss at later stages of life. Infectious conditions that may lead to hearing loss include severe ear infections, tuberculosis, syphilis, lyme disease, brucellosis, cytomegalo virus, herpes, AIDS, bacterial meningitis. Immune mediated diseases that are associated with hearing loss include Cogan’s syndrome, relapsing polychondritis, Wegener’s granulomatosis,
Ovarian Cancer
lupus, Takayasu’s disease, and giant cell arteritis. Tumors such as those that occur with acoustic neuroma, squamous cell carcinoma, and paragangliomas are also common causes of hearing loss. A number of metabolic disorders, including diabetes, hyperthyroidism, hyperlipoprotinemia, hypertension, and vascular and hematologic problems may also result in hearing loss. When diagnosing deafness, otologists determine whether hearing loss is sensorineural or conductive. In the first case, hearing loss may be caused by a lesion of the cochlea or the auditory nerve. In conductive hearing loss, a lesion may be affecting the transmission of sound energy from outside the ear into the cochlea. SEE ALSO: AIDS; Birth Defects; Deafness; Diabetes; Im-
munology; Infant and Toddler Health; Infectious Diseases (General); Ophthalmology; Sports Injuries; Sudden Infant Death Syndrome (SIDS); Tuberculosis. BIBLIOGRAPHY. Beyond Discovery, “Sound from Silence:
The Development of Cochlear Implants” www.beyonddiscovery.org/content/view.article (cited July 2007); Bloyce Hill Britton, ed., Common Problems in Otology (Mosby, 1991); Gordon B. Hughes, ed., Textbook of Clinical Otology (Theime-Strannon, 1985); Gordon B. Hughes and Myles L. Pensak, eds., Clinical Otology (Stuttgart, 1997); Bruce W. Jafek and Anne K. Stark, eds., ENT Secrets (Hanley and Belfus, 1996); Frank E. Musiek, ed., Contemporary Issues in Clinical Audiology (B.C. Decker, 1989); Rachel Nowak, “Ear Implant Success Sparks Culture War.” New Scientist, 25 November 2006, pp. 16-17; Daniel J. Pender, Practical Otology (J.B. Lippincott, 1992). Elizabeth R. Purdy, Ph.D. Independent Scholar
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and the desire of many people to remain at home or with their families, has resulted in a system of outpatients in which people can visit a hospital for regular treatment, further diagnosis, or for the renewal of prescriptions and the like. Sometimes, outpatients have been referred to a hospital by another medical professional. On other occasions, the patient has already visited a hospital in the past and is returning for continued treatment or further diagnosis. To cater to this, there are inpatient areas at many hospitals to differentiate between inpatients who stay overnight and outpatients who do not. It is also worth observing that many inpatients, on their discharge from a hospital, become outpatients if they require continued hospital care. While the level of treatment or diagnosis for an outpatient at a hospital does not, on occasion, differ significantly from their treatment in a medical center or clinic, the term outpatient is only used at hospitals because medical centers and clinics generally do not have the capacity to keep patients overnight; hence, there is no need for the differentiation. There also exists hospital outpatient care, where ongoing treatment is administered to the patient in his or her own home by hospital staff. This lessens the demand on beds in a hospital, and provides the treatment required, as well as regular supervision. SEE ALSO: Inpatient; Primary Care. BIBLIOGRAPHY. Paul D. Chan, et al., Outpatient and Pri-
mary Care Medicine, 2005 Edition (Current Clinical Strategies Publishing, 2004); Lorri A. Zipperer, ed., The Health Care Almanac: A Resource Guide to the Medical Field (American Medical Association, 1995). Justin Corfield Geelong Grammar School, Australia
Outpatient A person who is getting medical attention, care, or treatment is known as a patient, the term deriving from the Latin word patiens. Many people come to a hospital to seek treatment for illnesses or conditions that are ongoing. If they stay overnight at a hospital, they become inpatients. However, the cost of keeping a person in a hospital,
Ovarian Cancer Ovarian cancer is cancer of the ovaries. Ovaries are round, golf ball shaped reproductive organs located below the abdomen in females. Normal females have two ovaries. Each ovary stores eggs, releasing one per menstrual cycle. Ovaries also produce and secrete
1312 Ovarian Cancer reproductive hormones. Ovarian cancer is the most lethal of all women’s reproductive cancers (breast, vaginal, cervical, endometrial / uterine, vulvar, etc.). Men do not have ovaries and therefore do not develop ovarian cancer. Scientists and physicians have identified several risk factors for developing ovarian cancer. These risk factors include obesity as a young adult, and having a family history of ovarian cancer. People who are extremely overweight have elevated circulating estrogen levels, which may predispose them to reproductive cancers such as ovarian cancer. Some women who undergo hormone replacement therapy after menopause may be at higher risk for developing ovarian cancer, due to the elevated estrogen levels. Additionally, ovarian cancer occurrences are usually in women over 50 years of age. There is no one gene associated with ovarian cancer, but there are several genes known to be associated sometimes with reproductive cancers. For instance, some genes for predisposition overlap between breast and ovarian cancers. Factors which lower a woman’s risk for ovarian cancer include use of oral contraceptives that combine estrogen with progesterone, bearing at least one child, breast-feeding a child, hysterectomy, and tubal ligation. Some of the symptoms of ovarian cancer include a heavy feeling in the abdomen, aches in the lower abdominal area, vaginal bleeding not associated with menses, abnormal menstruation, unexplained progressive back pain, and unexplained changes in weight. Furthermore, a woman with ovarian cancer may feel bloated and may experience premature fullness when eating. She may also be constipated and/or experience pain during intercourse. As with other cancers, the earlier the diagnosis of ovarian cancer, the better the prognosis. Nevertheless, ovarian cancer is difficult to detect, often until it is well advanced. One reason for difficult detection is that symptoms of ovarian cancer are the same as for benign diseases, whether in the ovary, reproductive system, or other tissues. For diagnosis of ovarian cancer, a patient needs to be examined by a reproductive cancer specialist, such as a physician in gynecologic oncology. The first sign is usually an abnormal pelvic exam, after which the referral is made to the specialist. Next, there are options for medical imaging techniques to identify sus-
picious tissue areas. These techniques include barium enema X-ray, colonoscopy, a Computed Tomography (CT) scan, Magnetic Resonance Imaging (MRI), and Ultrasound. A biopsy and blood sample may also be taken. A biopsy is the removal of a small sample of the tissue in question, which is then analyzed under a microscope. The blood sample can be examined for levels of free hormones and other factors. Because ovarian cancers may involve hormone-producing cells, the excessive cellular growth may result in elevated circulating hormone levels in the woman. These levels can be analyzed in a blood sample, and may aid the physician to diagnose the particular type of cancer. The current treatment for ovarian cancer is surgical removal of the tumor cells, followed by chemotherapy. Surgical removal of one ovary is called a unilateral oophorectomy; a bilateral oophorectomy is the surgical removal of both ovaries. If the whole tumor cannot be removed, the surgeon may remove only a part of the tumor. This process is called debulking. There is evidence that even debulking can lead to a better prognosis. Chemotherapy often follows surgery. The medications can be delivered by oral means or intravenous (IV) injection. In the United States, radiation therapy is rarely used to treat ovarian cancer. The type of ovarian cancer determines how much tissue is removed surgically. The types of ovarian tumors are epithelial, germ cell, low malignant potential (LMP) or stromal tumors. An epithelial tumor is one that involves the epithelial tissue surrounding the ovary, and typically calls for bilateral oophorectomy. Tumors that are not as malignant may require unilateral oophorectomy along with the adjoining fallopian tube (unilateral salpingectomy). Germ cell tumors call for the same treatment, most often including chemotherapy. Germ cells are the actual eggs inside the ovary. When these eggs because cancerous, it is called germ cell ovarian cancer. Surgical removal of the affected ovary, but not the fallopian tube, is typically performed for a stromal tumor, which is a tumor of the connective tissue of the ovary. Another cause for concern would be an ovarian low malignant potential tumor, a state which involves precancerous cells in the tissue surrounding the ovary. It may or may not become cancerous, but often physicians recommend removing the entire ovary as a precautionary measure. When one ovary is found
with an ovarian low malignant potential tumor, the other ovary should be examined carefully as well. A major side effect of treatment for ovarian cancer may be infertility. Women who may want to have children in the future are recommended to store their eggs before treatment commences, as a precaution. Additionally, as with any cancer treatment in the pelvic area, there may be sexual side effects such as painful or difficult intercourse. Furthermore, physical and emotional stress in the patient may lead to depressed sexual desires as well as anxiety about intercourse and intimacy. These latter side effects are commonly found following any cancer treatment. While there is no guaranteed lifestyle to prevent recurrence of ovarian cancer, there are recommendations for diet and exercise, as given by the National Cancer Institute. These recommendations include eating plenty of fruits and vegetables, and mostly whole grains instead of processed or bleached grains. These food items contain a high amount of phytochemicals, which are beneficial in their antioxidant, antiestrogen properties. These foods may also have chemoprotective properties. Specifically, cruciferous vegetables such as broccoli and kale, and other vegetables such as green leafy vegetables and gourds are recommended. Additionally, a healthy fat intake of providing less than one-third of a person’s daily caloric intake is helpful. Other calories can come from proteins and carbohydrates. A corollary to the latter recommendation is maintaining a healthy weight. Finally, limiting intake of cured, pickled, or smoked foods, as well as alcoholic beverages is highly recommended. SEE ALSO: American Fertility Association (AFA); Ameri-
can Society of Clinical Oncology; Breast Cancer; Cancer (General); Cancer Alternative Therapy; Cancer Chemotherapy; Cancer Radiation Therapy; Cancer—Coping with Cancer; Cervical Cancer; Chemoradiotherapy; Chemotherapy; National Cancer Institute (NCI); National Coalition for Cancer Survivorship (NCCS); National Program of Cancer Registries (NCCS); Oncologist; Oncology; Uterine Cancer; Vaginal Cancer. BIBLIOGRAPHY. American Cancer Society, “How is
Ovarian Cancer Diagnosed?”, www.cancer.org (cited August 2007); Kristine Conner and Lauren Langford, Ovarian Cancer (Patient-Centered Guides) (Patient Centered Guides, 2003); Don S. Dizon, 100 Questions & Answers
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about Ovarian Cancer, 2nd ed. (Jones and Bartlett Publishers, Inc., 2006); National Cancer Institute, A Snapshot of Ovarian Cancer (National Cancer Institute, 2006). Claudia Winograd University of Illinois at Urbana-Champaign
Over-the-Counter (OTC) Drug Over-the-counter (OTC) drugs are medicines that may be purchased without a prescription from a medical provider with prescribing authority, such as a physician. In the U.S., there are more than 80 therapeutic categories of OTC drugs, ranging from acne drug products to weight control drug products. The potential for misuse and abuse of OTC drugs is generally low and their benefits usually outweigh their risks. These medications are intended for conditions that consumers can self-diagnose, such as headache and heartburn, and in general, do not require close monitoring by health practitioners to ensure their safe and effective use. OTC drugs play an important role in global health by providing easy access to certain drugs that can be used safely without the help of a health care practitioner. This enables consumers to take control of their own health care in many situations and provides quick access to effective medications without the burden and expense of a medical visitation. There are more than 100,000 OTC drug products marketed in the U.S., encompassing about 800 active ingredients. OTC drugs usually have little or no abuse potential, although in some areas, drugs such as codeine are available OTC, though usually in strictly limited formulations or requiring paperwork or identification prior to purchase. Common OTC drug classes include acne drug products, antacids, antiemetics, antiflatulents, topical antifungals, cough and cold preparations, oral antihistamines, non-narcotic analgesics, nonsteroidal antiinflammatory drugs, and weight control products. Some of the most commonly purchased OTC drugs include aspirin, ibuprofen, acetaminophen, pseudoephedrine, and dextromethorphan. In the United States, the Food and Drug Administration (FDA) regulates the manufacture and sale of OTC drugs. As with prescription drugs, the FDA
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works to ensure that OTC drugs are properly labeled and that their intended benefits outweigh their risks. However, the approval and regulatory process for OTC drugs is much different compared to that for prescription medications. Whereas development of prescription drugs must be pursuant to a New Drug Application (NDA), manufacture of OTC drugs can be pursuant to a NDA or pursuant to an FDA monograph. Because an NDA is extremely expensive to obtain, due primarily to clinical testing requirements, most OTC drugs developed in the U.S. are manufactured pursuant to a monograph, if applicable. Amendments to the Federal Food, Drug, and Cosmetic (FD&C) Act created monographs for OTC drugs in 1962. Monographs can be thought of as “recipe books” covering acceptable active ingredients, doses or concentrations, formulations, required labeling, and in some cases, packaging and testing requirements. OTC drug monographs are continually updated to add additional ingredients and labeling as needed. Products conforming to a monograph may be marketed without FDA pre-approval, while prescription only drugs and OTC drugs that do not conform to monographs must undergo separate review and approval through the NDA process. Many currently available OTC medications, which were previously available only by prescription, were first approved through the NDA review process. Typical OTC products manufactured pursuant to an FDA monograph, rather than pursuant to a NDA and then switched to OTC status, include sunscreens, topical antifungals, oral and topical analgesics such as aspirin and lidocaine, psoriasis and eczema topical treatments, and antidandruff shampoos. All OTC drugs are required to be accompanied by labels, which include information such as uses, warnings, directions, and healthcare provider instructions. In many countries, medical devices may also be considered OTC. The term “medical device” covers a broad range of entities typically including instruments, apparatuses, machines, implants, and contrivances intended for the use in diagnosing, treating, or preventing disease. For example, most diabetic management supplies, including electronic blood glucose monitors, monitor test strips, and lancets, are available OTC, as are blood pressure monitors. In some areas, insulin syringes may also be available OTC because some jurisdictions have
classified syringes as limited OTC products as a measure of drug addiction harm reduction. The status of a substance (i.e. herbal remedy, dietary supplement, OTC drug, or prescription only drug) can vary from country to country. Substances that are classified as herbal remedies in one country may be defined and regulated as drugs in another. Certain medications may be available OTC in one country but may require a prescription in another. For example, in 2004 the United Kingdom became the first nation to approve HMG-CoA reductase inhibitors (also called “statins”) for OTC use. As of 2006, no statins were available OTC in the U.S. OTC Drugs versus Other Non-prescription Products Often, there may be confusion, particularly in the U.S., around what is considered a drug versus a cosmetic or a drug versus a dietary supplement. In the U.S., the difference between these agents, in legal terms, is determined by a product’s intended use. In the U.S., the FD&C Act defines drugs, both prescription only and OTC, as, “(A) articles intended for use in the diagnosis, cure, mitigation, treatment, or prevention of disease … and (B) articles (other than food) intended to affect the structure or any function of the body of man or other animals” [FD&C Act, sec. 201(g)(1)]. The FD&C Act defines cosmetics, as, “articles intended to be rubbed, poured, sprinkled, or sprayed on, introduced into, or otherwise applied to the human body … for cleansing, beautifying, promoting attractiveness, or altering the appearance” [FD&C Act, sec. 201(i)]. Commonly used cosmetics include skin moisturizers, perfumes, lipsticks, fingernail polishes, eye and facial makeup preparations, shampoos, permanent waves, hair colors, toothpastes, and deodorants. Dietary supplements, including herbal remedies, are different than OTC drugs and are regulated in the U.S. by the FDA under a different set of regulations than those covering foods and prescription and OTC drug products. A dietary supplement is a product that contains an ingredient intended to supplement the diet, such as vitamins, herbs or other botanicals, amino acids, and enzymes. According to the Dietary Supplement Health and Education Act of 1994 (DSHEA) manufacturers of dietary supplements cannot make claims that these products treat, prevent, or
cure a specific disease or condition. Under DSHEA, the dietary supplement manufacturer is responsible for ensuring that a dietary supplement is safe before it is marketed. The FDA is responsible for taking action against any unsafe dietary supplement product after it reaches the market. Generally, manufacturers do not need to register their products with FDA nor get FDA approval before producing or selling dietary supplements. Manufacturers must make sure that product label information is truthful and not misleading. Prescription to OTC Switch Prescription to OTC switch refers to over-the-counter marketing of a product that was once a prescription drug product for the same indication, strength, dose, duration of use, dosage form, population, and route of administration. Over time, drugs that prove to be safe and appropriate for self-medication may be switched from prescription only status to OTC. An example of a prescription to OTC switch is diphenhydramine, which once required a prescription but is now available OTC nearly everywhere. More recent examples are loratadine for allergy treatment and omeprazole for heartburn in the U.S., and simvastatin for high cholesterol in the United Kingdom. There are several mechanisms by which a manufacturer accomplishes prescription to OTC switch depending on the objective of the switch. For example, to switch the drug product covered under the NDA to OTC marketing status in its entirety without a change in the previously approved dosage form or route of administration, a manufacturer should submit an efficacy supplement to the FDA. To convert some, but not all, of the approved prescription indications to OTC marketing status, a manufacturer must submit an NDA 505(b)(1). Certain drugs are available OTC at small doses and are also available as prescription only drugs in larger doses. For example, in the U.S. ibuprofen is available OTC in doses of 200 milligrams (mg) whereas ibuprofen 400mg and ibuprofen 800mg are available by prescription only. Also, in the U.S., regular insulin formulations may be purchased without a prescription, even though the vials are kept in the pharmacy since they must be stored in the refrigerator. Other insulin formulations, such as rapid acting and long acting varieties, are only available with a prescription.
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OTC Safety Issues It is somewhat unusual for an OTC drug to be withdrawn from the market as a result of safety concerns. Adverse events associated with the use of OTC drugs can be reported to the FDA via the MedWatch safety reporting system and occasionally OTC drugs are removed from the market, as was the case with phenylpropanolamine. Unlike with prescription medications, not all OTC drug manufacturers need to report consumer reported adverse drug reactions to the FDA. The MedWatch program allows health care professionals and consumers to report adverse events, as well as suspected product quality problems and product use problems. Misuse of OTC Drugs While OTC drugs are usually required to have little or no abuse potential, some individuals have discovered methods of chemically modifying OTC drugs to create drugs with significant abuse potential. For example, many U.S. pharmacies have recently started relocating products containing pseudoephedrine to behind the pharmacy counter where customers must ask a pharmacist for them. Using basic chemistry techniques, psuedoephedrine can be changed into methamphetamine, a highly addictive and illegal drug. Since the passage of the Methamphetamine Precursor Control Act, the purchase of pseudoephedrine in the U.S. is restricted and the identity of the purchaser is required to be obtained and recorded. While a prescription is not required, acquiring psuedoephedrine must be done by visiting the pharmacy counter and requesting the medication. This policy is intended to limit access to large quantities of psuedoephedrine, thereby reducing methamphetamine production. SEE ALSO: Food and Drug Administration (FDA); Herbal
Remedy; Pharmaceutical Industry (Worldwide).
BIBLIOGRAPHY. Food and Drug Administration, “Office
of Nonprescription Products,” www.fda.gov/cder/offices/ otc/ (cited October 2006); Food and Drug Administration, “Dietary Supplements,” www.cfsan.fda.gov/~dms/supplmnt.html (cited October 2006); Food and Drug Administration, “Cosmetics,” www.cfsan.fda.gov/~dms/cos-toc. html (cited October 2006); Richard P. Donjon and Bryon J. Goeckner, Mosby’s OTC Drugs: An Over-The-Counter Drug Resource for Health Professionals (Mosby 1999); PDR
1316 Ozone for Nonprescription Drugs, Dietary Supplements, and Herbs, The Definitive Guide to OTC Medications (Thompson PDR, 2006). Joshua J. Gagne, PharmD Jefferson Medical College
Ozone Ozone is a triatomic molecule that consists of three oxygen atoms and its molecular formula is O3. This is much less stable than the normal oxygen (O2) and is found in low concentrations throughout the Earth’s atmosphere. It also has industrial and consumer applications, and for medical care, it is used to destroy foreign bodies and also in ozone therapy. While its use within human (and animal) bodies remains controversial, its use as a cleansing or sterilizing agent has become more common. Some of the properties of ozone were first described by Christian Friedrich Schönbein in 1840 who named it from the Greek word ozein meaning “smell” after the odd odor that occurred during lightning storms. The smell had been described in scientific literature from 1785, but it was not until 1872 that the chemical composition of ozone was established. Artificial ozone is manufactured by passing an electric discharge through a current of oxygen or dry air, with the resulting mixtures of ozone and original gases being suitable for most industrial purposes. However, for medical purposes, ozone is created by liquefaction with the oxygen–ozone mixture separating into two layers, the denser one being 75 percent ozone. Ozone itself is an irritating, pale blue colored gas that is both toxic and explosive, even at relatively low concentrations. It is present in large amounts in the atmosphere, where it absorbs solar ultraviolet radiation, and as a result, prevents these rays from causing severe damage to living organisms on the Earth’s surface. However, there has been much concern about the declining levels of it—the ozone hole—associated with greenhouse gas emissions, which have been a major part of the debate about the Earth’s ecology in the late 20th and early 21st centuries. This, in turn, has been blamed on the higher prevalence of skin cancer in
some countries especially in Australia, South Africa, southern Argentina, Chile, and other areas affected by the “ozone hole.” In late Victorian Britain, there was a common view that the smell of the sea was caused by ozone, and as a result, the belief in the health benefits of breathing in sea air became associated with ozone. However, ozone in medical treatment has a vastly different method of application and use. Some reactive forms of oxygen such as ozone, but also including superoxide and singlet oxygen, are naturally produced within the human body by white blood cells and also in some other biological systems, such as in the roots of marigolds, to destroy foreign bodies. This is because the ozone reacts directly with organic double bonds. In 2003, Dr. Paul Wentworth Jr. and a team of doctors and researchers at the Department of Chemistry at the Scripps Research Institute in La Jolla, California, conducted a series of experiments that have indicated evidence linking the antibody-catalyzed-oxidation pathway of the human immune response to the production of ozone. However, its use is problematic as it is known to convert cholesterol in the human blood stream into plaque, which serves to narrow the arteries and lead to higher incidences of heart attacks and other serious problems. Ozone therapy has been used as alternative medicine in a number of countries, but its application is controversial. Ongoing research continues on its helpful and harmful effects. The use of ozone generally has become common because of its properties involved in killing bacteria, and ozone has gradually come to be used more than chlorine. At water treatment plants, ozone has been shown to eradicate parasites such as Giardia and Crytosporidium, the process becoming known as ozonation. In industry, ozone or ozonated water is often used to disinfect water before it is bottled as well as kill bacteria on food or on food or kitchen preparation surfaces. Some food suppliers also use it to clean fresh fruits and vegetables where it kills yeast, mold, and other bacteria. In hospitals, it is also used to make operating rooms sterile, serving as a very effective decontaminant between surgeries, with rooms being sealed airtight and then filled with ozone, which kills or neutralizes all bacteria. It has also been used to sterilize some hospital equipment. SEE ALSO: Environmental Health; Immune System and
Disorders; Parasitic Diseases.
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The growth of the ozone hole over Antarctica from 1979 to 1990. There has been much concern about the declining levels of ozone associated with greenhouse gas emissions, which have been a major part of the debate about the Earth’s ecology.
BIBLIOGRAPHY. Fernando J. Beltran, Ozone Reaction Ki-
netics for Water and Wastewater Systems (Lewis, 2004); Marquita K. Hill, Understanding Environmental Pollution (Cambridge University Press, 2004); August Greeley, Burning Up: Losing our Ozone Layer (Rosen Publishing Group, 2003); Jelte Rozema, Rien Aerts, and Hans Cornelissen,
Plants and Climate Change (Springer, 2006); Christopher Spence, Global Warning: Personal Solutions for a Healthy Planet (Palgrave Macmillan, 2005). Justin Corfield Geelong Grammar School, Australia
P Paget’s Disease of Bone Paget’s disease, also known as osteitis deformans, is a condition caused by an initial increase in the breakdown of bone followed by chaotic, atypical creation of replacement bone. Paget’s disease is the second most common bone disease following osteoporosis. In the United States, Paget’s disease is prevalent in 3 to 4 percent of the general population older than 40 years of age. Globally, Paget’s disease is present in approximately 10 percent of the population older than 80 years of age. Overall, Paget’s disease is present in males and females with a ratio of 1.8:1. This disease bears resemblance only in name to other diseases named after the 19th century British pathologist Dr. James Paget, such as Paget’s disease of the breast. In a healthy adult, breakdown of bone is balanced with formation of new bone, so that no net increase in bone mass occurs. Paget’s disease begins when osteoclasts (the cells that break down bone) become hyperactive, breaking down too much bone, and creating what are called lytic lesions. These lesions are most often found in the axial skeleton, particularly the skull and spine. Generally, the lytic lesions are at specific points in the skeleton and do not become widespread. After the lytic lesions have formed, the number of osteoblasts (the cells that create new bone) increase in
the surrounding bone as a response to the osteoclastic destruction. These osteoblasts secrete new bone matrix, but the replacement bone lacks the organized structure of normal bone. This results in enlargement and significant weakening of the affected bones. Most patients with Paget’s disease are actually asymptomatic. When symptoms do occur, localized skeletal pain is the most common symptom. An affected skull can compress cranial nerves, causing nerve deafness, blindness, or facial pain. If the skull base becomes flattened (known as platybasia), the brainstem is often compressed as it exits the skull. Enlarged facial bones result in disfigurement. Affected vertebrae can compress spinal nerve roots, causing both motor and sensory deficits. Fractures in affected weight-bearing bones are very common as well. Because the increased bone mass requires additional blood supply, some patients also develop high-output cardiac failure. In addition, patients with Paget’s disease have an increased risk for malignant bone tumors, most common being osteosarcomas occurring in 5 percent of individuals with the disease. Recent studies and epidemiological data provide strong evidence that a viral infection may trigger Paget’s disease. Osteoclasts are not only more numerous but also larger and abnormal in appearance. Paget osteoclasts can have as many as 100 nuclei, more than
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1320 Pain five times the normal number; also, the nuclei have inclusions that are typical of infection by viruses in the family Paramyxoviridae, which includes the measles virus and the respiratory syncytial virus. Both proteins and genetic markers unique to the measles virus have been discovered in osteoclasts from Paget patients by multiple investigators. Furthermore, the measles virus is known to cause severe encephalitis years after childhood infection, so a similar latent phenomenon may be at work in Paget’s disease. However, despite these intriguing discoveries, definitive isolation of a causative virus for this bone disorder remains elusive. Research is ongoing into how viral infection of osteoclasts might lead to Paget’s disease. Some studies have found that abnormal osteoclasts are hyperresponsive to signaling molecules that increase their activity, such as vitamin D (calcitriol) and the RANK ligand. Also, increased levels of certain chemical signals, particularly interleukin-6, have been found in cultures of Paget osteoclasts, suggesting there is an imbalance in signaling within the diseased bone. Strong evidence also exists for a genetic cause of Paget’s disease. Between 15 to 40 percent of patients have a parent or sibling with the disease. Pedigree analyses of families with Paget’s disease suggest an autosomal dominant inheritance pattern. The disease is prevalent in populations of British lineage and appears to follow migrations of these people (e.g., to the United States, Canada, Australia, and New Zealand). However, immigrants moving to Great Britain do not eventually develop an increased risk of Paget’s disease, suggesting that an infectious or environmental cause is not sufficient to cause disease. Using modern molecular biology techniques, several gene mutations have been discovered in Paget patients. Research is ongoing into how these mutations affect the activity of osteoclasts, but studies suggest that disruption of the cellular signaling pathways that regulate osteoclasts may be at fault. Thus, there is solid evidence for both a viral and a genetic cause for Paget’s disease of the bone. In fact, both factors may be necessary for someone to develop the disease; a person with genetic susceptibility might develop Paget’s disease only after infection with the proposed causative virus. Diagnosis of Paget’s disease is made using several tests, including the blood level of alkaline phos-
phatase enzyme, which is dramatically elevated. Blood levels of calcium and phosphate, the two major mineral components of bone, are actually normal. Radiographs of the affected bones are also very useful. Treatment for Paget’s disease is aimed at reducing the destructive activity of the abnormal osteoclasts. Drugs known as biphosphonates are the first-line treatment, as they directly inhibit osteoclasts. Patients can enter remission if they are taking biphosphonates, sometimes remaining symptom-free for many years. Furthermore, the hormone calcitonin, normally produced by the thyroid gland to reduce bone resorption by osteoclasts, has also been given as a drug, but is less effective than the biphosphonates. In addition, new therapies might be aimed at shutting down the hyperactive signaling pathways that drive the osteoclasts, such as blocking the RANK ligand or vitamin D from binding to osteoclasts. SEE ALSO: Bone Diseases; Bone Health; Multiple My-
eloma; National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS); Orthopedics; Orthopedist; Osteoporosis.
Bibliography. Nicholas Athanasou, Pathological Basis
of Orthopaedic and Rheumatic Disease (Arnold, 2001); G. David Roodman and Jolene Windle, “Paget Disease of the Bone,” Journal of Clinical Investigation (v.115, 2005); Emanuel Rubin, et al., Rubin’s Pathology: Clinicopathologic Foundations of Medicine, 4th ed. (Lippincott Williams & Wilkins, 2005). David B. Bumpass Francis H. Shen, M.D. University of Virginia Dino Samartzis, D.Sc., M.Sc., Dip. EBHC Harvard University and Erasmus University
Pain Pain is an unpleasant, subjective experience that typically accompanies physical or psychological distress. Pain is usually described as being either nociceptive (in response to actual or potential tissue
Numerous treatments for both acute and chronic pain are available. In more severe cases, surgery may be required.
damage) or neuropathic (caused by dysregulated nervous system activity). Nociceptive pain begins with nociceptors: specialized transducing elements in the tissue that convert heat, cold, and mechanical energy to electrical signals. These signals are sent to the central nervous system via two main types of nerve fibers. Thin, A-Delta fibers transmit a fast, sharp pain that causes an organism to quickly withdraw from the dangerous stimulus. A second deep and throbbing pain, mediated by C fibers, causes the organism to protect the damaged area while it heals. These nociceptive signals ascend the spinal cord and terminate in the brain where the experience of pain is generated. The pain experience itself further involves numerous brain regions associated with the sensory (thalamus and somatosensory cortex), affective (hypothalamus, medial thalamus, and limbic system), and cognitive (dorsolateral prefrontal cortex, dorsal anterior cingulate cortex) components of pain. Other brain regions, such as the periaqueductal gray and rostral ventromedial medulla, can increase or decrease the experience of pain. These structures modify nociceptive signaling in the spinal cord via descending dopaminergic, serotonergic, and norepinephrinergic pathways. Pain may also have neuropathic origins. Neuropathic pain is caused by damage or dysregulation in the peripheral or central nervous system. The altered pain response causes a state of hyperexcitability in the
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neurons that relay nociceptive information. This state of hyperexcitability can result in a continuous output of pain signals, even in the absence of any observable tissue damage. Neuropathic pain is characterized by burning, shooting, and electric shock sensations. While the control of acute pain is a major clinical concern (particularly in neonatal and perioperative pain), chronic pain is receiving increasing attention from researchers. This type of pain can last indefinitely, and has a devastating impact on social, cognitive, physical, and emotional well-being. Chronic pain may be associated with sleep difficulties, secondary fatigue, cognitive problems, depression, and anxiety. Individuals with these conditions often reduce their activities due to their fear of causing additional pain, and they risk being alienated from important social networks. Chronic pain may be nociceptive, neuropathic, or idiopathic (of unknown origin). Chronic nociceptive pain is secondary to actual tissue damage. Examples are rheumatoid arthritis and osteoarthritis. Chronic neuropathic pain can be caused by physical trauma (phantom limb pain), viral infection (postherpetic neuralgia), and other medical conditions (diabetic neuropathy and trigeminal neuralgia). Idiopathic pain syndromes generally share characteristics of diffuse musculoskeletal pain, hypersensitivity to pain stimuli, and comorbid psychological complaints. In these disorders, no evidence for tissue damage or nervous system lesion can be found. Examples include fibromyalgia, irritable bowel syndrome, and some instances of chronic lower back pain. Numerous treatments for both acute and chronic pain are available. Nociceptive pain may be attenuated by treating the underlying injury. For example, migraine headaches can be treated by administering vasoconstrictors. Drug therapy for acute pain includes the use of nonsteroidal antiinflammatory agents (NSAIDs) for minor pain and opioid analgesics for moderate to severe pain. These medications, however, are less effective in reducing chronic neuropathic and idiopathic pain. Many medications are prescribed off-label for the treatment of chronic pain, and can be effective for patient subgroups. Examples include antidepressants, anticonvulsants, anxiolytics, and neurotoxins. In more severe cases of persistent and disabling pain, surgery may be required. Some procedures include spinal cord stimulators, implanted drug delivery systems, and deep brain stimulation.
1322 Pakistan Individuals vary considerably in the amount of disability they experience as a result of pain. Some of these differences have been associated with genetic influences, gender, hypertensive status, and other biological/physiological factors. Psychosocial factors, such as social support and coping strategies, can also modulate the degree of suffering. Some psychological states attenuate pain by activating the brain sites that block spinal pain. Activity in these regions may be modulated by noninvasive interventions such as mindfulness meditation and real-time functional magnetic resonance imaging feedback training. Great progress is being made in understanding the peripheral and central mechanisms of chronic pain so that better treatments can be found for this devastating condition. SEE ALSO: Arthritis; Neurology; Primary Care. Bibliography. A. I. Basbaum and D. Julius, “Toward Bet-
ter Pain Control,” Scientific American (June 2006); S. McMahon and M. Koltzenburg, eds., Wall and Melzack’s Textbook of Pain, 5th ed. (Churchill Livingstone, 2006). Jarred Younger, Ph.D. Daena Watcha Sean Mackey, M.D., Ph.D. Stanford University
Pakistan This country in South Asia was formed with the partition of India in 1947. Prior to that, Pakistan had been two parts of British India, West Pakistan being on the western border of India, and East Pakistan, in the east, almost entirely surrounded on land by India—East Pakistan becoming Bangladesh in 1971. The population of Pakistan is 165,804,000 (2004) and there are 57 doctors and 34 nurses per 100,000 people. During the period of British colonial period, healthcare in hospitals for the European population and the wealthy local elite was good, with medical facilities being located in all the cities and most of the towns. The major hospitals were the Mayo Hospital, and the King Edward Medical College, both in Lahore. After independence, there was government pressure to increase the provision of healthcare for all the people
in the country, and medical care in the main city in Karachi, the country, as well as in Rawalpindi, and in the new capital Islamabad, has been relatively good, although it still is extremely problematic in remote parts of the country. The Pakistan Medical Research Council was founded in 1953 to promote research in the fields of medicine and public health in Pakistan, and was reconstituted in 1962. It publishes the quarterly Pakistan Journal of Medical Research. Many large hospitals have now been built throughout Pakistan, staffed by doctors trained overseas and locally, with many universities in Pakistan offering medical courses. The major university in the country is the University of Karachi which has faculties of Pharmacy and Medicine. The Aga Khan University in Karachi, run by the Aga Khan Foundation, has a large Faculty of Health; and the Gomal University at Dera Ismail Khan, in North West Frontier Province, there is a Faculty of Pharmacy. The Pakistan Council for Science and Technology (P.C.S.T.), Islamabad, advises the Pakistan government on science and technology policy, and it works with the National Institute of Health, also based in Islamabad. Plans to overhaul the national health service of Pakistan started with the Second Five-Year Plan from 1960 until 1965. This continued through to the Eight Five-Year Plan from 1993 until 1998. Many of the medical problems faced by people in Pakistan were concerned with bad hygiene and lack of access to clean drinking water. These included typhoid, cholera, tuberculosis and dysentery. However with improved sanitation, and the provision of clean water to remote villages, these problems have been significantly reduced. However there has been a rise in illicit drug taking and HIV/AIDS. There was also an outbreak of dengue fever in Pakistan in October 2006. There has been an increasing problem of cancer in Pakistan, partly because of the increase in the age at which people are living. Mohammed Ali Jinnah, the founder of Pakistan, himself died from cancer, but it was not until 1954 that the Cancer Research Institute of Pakistan was established, followed by the founding of the Karachi Cancer Registry. For men, the most common cancers remain lung cancer and oral cancer, with women most susceptible to breast cancer and cervical cancer. Of the many new hospitals which have opened in Pakistan and which treat cancer patients, mention should be made of the Shaukat Kha-
Palau
num Memorial Cancer Hospital and Research Center established in Lahore by the cricketer Imran Khan who founded it in 1989 in memory of his mother who had died from cancer. It treated its first patients in December 1994. SEE ALSO: Cholera; Influenza; Typhoid. BIBLIOGRAPHY. S. Akbar Zaidi, The Political Economy of
Healthcare in Pakistan (Vanguard Books, 1988); F.U. Baqai, “Traditional Medicine in Pakistan,” in History of Traditional Medicine: Proceedings of the 1st and 2nd International Symposia on the Comparative History of Medicine—East and West (1976–1977); R.M. D’Souza and J.H. Bryant, “Determinants of Child Mortality in Slums of Karachi, Pakistan,” Journal of Health and Population in Developed Countries (v.2/1, 1999). Justin Corfield Geelong Grammar School, Australia
Palau Palau is the westernmost cluster of the Caroline Islands in the central Pacific Ocean. When the U.S. Trust Territory formed at the end of World War II was coming to an end, Palau elected not to become part of the new Federated States of Micronesia, declaring its independence in 1978 and emerging from trusteeship in the early 1990s. Palau, sometimes called Belau, is comprised of more than 300 islands in 6 island groups, but has a total land area of just 458 square kilometers. The average temperature is 82 degrees Fahrenheit, the average humidity is 82 percent, and rainfall is about 150 inches a year. The population is 25,600 and growing at a rate of 1.31 percent annually. Unusual for a small island nation, it is actually gaining more residents than losing, with a net migration rate of 1.85 per 1,000. With a stable government and an economy based on tourism, subsistence agriculture and fishing, Palauans enjoy one of the highest standards of living in the Pacific Island region. Life expectancy is 67 years for males and 73 years for females, with healthy life expectancy at 59 years for men and 61 years for women. Child mortality is 10
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deaths per 1,000 for infants under 1 years old and 11 deaths per 1,000 for children aged 1 to 5. Childhood immunization is almost universal. There were no reported maternal deaths in childbirth between 1990 and 2005, and 100 percent of births are monitored by trained attendants. The fertility rate is 2.46 births per woman, despite the fact that only 17 percent of women report using modern birth control methods. The leading causes of morbidity in Palau in the 2004 reporting year were injuries (including motor vehicle accidents, suicides, and homicides), upper respiratory viruses, ear infections, gastroenteritis and digestive disorders, and tonsillitis. Major causes of mortality were cardiovascular disease, circulatory disorders, injury, and cancer. About 85 percent of Palauans have access to clean drinking water, and 80 percent have sanitary facilities. Solid waste disposal is a problem on some islands. There are relatively few infectious diseases affecting island residents: for example, in 2004, there were 57 cases of dengue fever, six cases of leprosy, and five cases of hepatitis. Although gonorrhea and tuberculosis are present in the population, there are no knownHIV/AIDS cases. Per capita government expenditures are $607. As with most island nations, delivering healthcare to a population spread across hundreds of square miles of open ocean can be a challenge. Palau relies on U.S. government funding in the development of new services and facilities. There is one general hospital in Koror, which was recently expanded to accommodate more patients. Medical personnel within the country includes 25 doctors, 111 nurses, 87 nursing aids, and 13 technicians. Most trained professionals are imported from other countries and therefore expensive; there are no medical schools on the islands, although a nursing program is being established at Palau Community College. SEE ALSO: Healthcare, Asia and Oceania. Bibliography. Jill Feasley and Robert Lawrence, eds., Pacific Partnerships for Health: Charting a Course for the 21st Century (1998); World Health Organisation, The World Health Report 2000 - Health Systems: Improving Performance (World Health Organisation, 2000).
Heather K. Michon Independent Scholar
1324 Palestine
Palestine Palestine, sometimes called the Occupied Palestinian Territory (OPT), is located in the Middle East but has no officially recognized borders at this time. The former British mandate of Palestine originally extended across the current State of Israel and into part of modern Syria. This mandate ended in 1947, and the United Nations passed a resolution creating the separate Jewish state of Israel and Arab state of Palestine. The resolution was rejected by the Arab world, leading to more than 50 years of conflict and Palestinian marginalization. Palestinians are today a stateless people with limited self-government under the Palestinian Authority, confined to two noncontiguous regions within Israel: the West Bank along the Jordanian border, and the narrow Gaza Strip, stretching along the Mediterranean coast the Egyptian boarder. The population of the OPT is estimated by the World Health Organization at 3.9 million, with 1.5 million living in Gaza and 2.5 million in the West Bank. Low infant mortality rates and the absence of major communicable diseases give Palestinians a life expectancy of 72.3 years. The fertility rate remains high, at 4.6 births per woman. Ongoing violence between Israel and the Palestinians makes life difficult for most of those in the occupied territories. Border closures and security crackdowns restrict movement. Palestinians fire crude bombs and rockets over the border, causing Israeli defense forces to retaliate with their own artillery bombardments and air strikes. Firing into densely populated areas often leads to civilian casualties. The United Nations noted that in July 2006, as world attention was focused on the conflict between Israel and Lebanon, 175 Palestinians were killed (including at least 40 children) in Israeli incursions in Gaza. The economy of the occupied territories has stagnated over the past several years. Unemployment is around 25 percent. Poverty levels are extremely high, at 56 percent in the West Bank and up to 80 percent in Gaza. Limited access to food has led to widespread malnutrition in Palestinian areas. A survey in spring 2007 found that 10 percent of Palestinian children suffer from chronic malnutrition, with 13.2 percent of children in Gaza and 7.9 percent of those in the West Bank showing signs of stunting. Anemia is also common, affecting 44 percent of children under 5, as well as 53
percent of women in Gaza and 44 percent of women in the West Bank. Eighty percent of Palestinian women of childbearing age are deficient in vitamins A and E. The Ministry of Health noted in 2005 that visits to mental health clinics rose by over 20 percent in a single year. Researchers have found that 33 percent of children in Gaza suffer from severe post-traumatic stress disorder (PSTD), with another 49 percent showing moderate signs of the illness. Fifty percent of children polled said they had lost at least one close family member to violence in their lifetimes. Parents also report a high level of aggression in their children. Noncommunicable diseases are the chief cause of morbidity and mortality in Palestine. However, the Ministry of Health notes that the region lacks a good monitoring system by which to track diseases such as diabetes and cardiovascular disorders. The Ministry of Health controls 60 to 70 percent of the 77 hospitals within the Palestinian Authority (22 in Gaza and 55 in the West Bank). Aside from general hospitals, there are 20 maternity hospitals, 10 specialized facilities, and four rehabilitation clinics. Medical staff is around 19,500, which includes those working for the Ministry of Health, nongovernmental organizations, the United Nations, and other international groups. SEE ALSO: Healthcare, Asia and Oceania; Israel; Jordan. Bibliography. Tamara Barnea and Rafiq Husseini, eds.,
Separate and Cooperate, Cooperate and Separate: The Disengagement of the Palestine Health Care System from Israel and Its Emergence as an Independent System (Greenwood Publishing Group, 2002); Samuel S. Kottek and Manfred Waserman, eds., Health and Disease in the Holy Land: Studies in the History and Sociology of Medicine from Ancient Times to the Present (Edwin Mellen, 1996). Heather K. Michon Independent Scholar
Panama Panama is located on a narrow strip of land that forms the geopolitical boundary between North and South America. The Panama Canal, bisecting the isthmus for 64 kilometers (40 miles)brought little prosperity to
Panamanians as the canal was built on land that had been leased to the United States. Panama regained control of the canal zone at the end of 1999. The population is approximately 3,242,000, growing at 1.564 percent annually. The birth rate is 21.45 per 1,000, the death rate is 5.44 per 1,000, and the migration rate is slightly in deficit at minus 0.37 per 1,000. Median age is 26.4. Life expectancy at birth is now 72.69 years for males and 77.8 years for females. Gross national income is estimated at $4,630, with about 7 percent of the population living on less than $1 a day. With a tropical climate and poor sanitation in large parts of the country, Panama is a perfect breeding ground for a variety of water-borne and vector-borne diseases and malaria is prevalent. While the last case of cholera was documented in 1993, diarrhea and other gastrointestinal complaints remain common. Acute respiratory infections are a leading killer among children, although immunization rates for vaccine-preventable diseases are good, and the country has been free from polio since 1972 and diptheria-free since 1981. HIV/AIDS first emerged in 1984 and now affects 0.9 percent of the adult population. There are an estimated 17,000 people living with the disease today. The Ministry of Health runs a national AIDS program but lacks the resources to fully exploit its strategic plan. Because Panama is somewhat erroneously designated as a upper-middle income nation, it has difficulty finding international donors to support their programs. Among the non-communicable diseases, cardiovascular disorders and cancers are the leading killers. Malnutrition is a continuing problem for children, particular in rural areas, where almost one-half of all children are underweight. About 18 percent of children under 5 show signs of stunting, the hallmark of chronic undernourishment. The country has made gains in infant and child mortality, with 19 deaths per 1,000 in those under 1 year and 24 deaths per 1,000 for those between the ages of 1 to 5. About 72 percent of pregnant women receive prenatal care, and 93 percent are assisted in childbirth by trained attendants. The maternal mortality rate is 160 deaths per 100,000 live births. The country devotes 7.7 percent of its gross domestic product to health care, and spends about $229 per capita. It has 4,400 doctors, 8,200 nurses, and around 5,000 healthcare workers. Panama boasts 19 major hospitals and a very high quality of in Panama City. Outside the city, medical centers are more widespread and limited.
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SEE ALSO: Healthcare, South America. Bibliography. Central Intelligence Agency, “Panama,” CIA World Factbook. https://www.cia.gov/library/publications/the-world-factbook/geos/pm.html (cited June 2007); The Pan American Health Organization, “Panama, Health in the Americas,” 1998. http://www.paho.org/english/HIA1998/Panama.pdf (cited June 2007).
Heather K. Michon Independent Scholar
Pan American Health Organization (PAHO) The Pan American Health Organization (PAHO) is an international public health agency that strives to improve health conditions throughout the Americas. In existence for more than 100 years, PAHO is the health organization of the Inter-American system and the regional site for the Americas of the World Health Organization (WHO), which bestows United Nation status on PAHO. Headquartered in Washington, D.C., there are offices in Argentina, the Bahamas, Belize, Bolivia, Brazil, Canada, Chile, Costa Rica, Barbados, Cuba, the Dominican Republic, Ecuador, El Salvador, Guatemala, Guyana, Haiti, Honduras, Jamaica, Mexico, Nicaragua, Panama, Paraguay, Peru, Puerto Rico, Suriname, Trinidad and Tobago, Uruguay, and Venezuela, plus a second mainland U.S. site in El Paso, Texas. A key focus of PAHO is emergency preparedness and disaster relief (PED). Through this initiative, PAHO helps countries prepare for disasters and to mitigate damage caused by them; coordinates humanitarian efforts, postdisaster; and helps countries manage disaster information and distribute it effectively. Through the information and knowledge management (IKM) initiative, PAHO supports the collection of public health information and encourages fair and equal access of information. This PAHO division also fosters collaborative efforts within PAHO and externally. Within that division is the Latin American and Caribbean Center on Health Sciences Information (BIREME), which maintains the Latin American and
1326 Pancreas Transplantation Caribbean Literature on Health Sciences (LILACS) and the Virtual Health Library (VHL). Another division of IKM is the bioethics unit (IKM/BI), which supports ethical assessments of biomedical research; the Research Promotion and Development Unit (IKM/ RC), which coordinates research projects, including the grant program. Finally, the Information and Knowledge Operations (IKM/KO) focuses on providing quality information online that it is accessible and relevant to the broad audiences who use PAHO services. A separate division creates and distributes written publications. The Health Analysis and Information Systems (AIS) division helps members and their governments to analyze and use health-related information to create public health policies. PAHO’s Family and Community Health (FCH) division emphasizes the central role of the family in fostering habits and lifestyles that promote good health. This division focuses on key stages of human development (infancy, childhood, and adolescence) and promotes healthy sexual behavior patterns. Under the FCH umbrella, PAHO focuses on women’s health throughout all life stages, but especially during reproductive years. The Latin American Center for Perinatology and Human Development (CLAP) focuses on maternal and infant health programs, while the Nutrition Unit (FCH/NU) focuses more specifically on optimal breast-feeding and quality foods for infants and children. The immunization unit works to deliver vaccinations throughout the Americas. PAHO helps to strengthen national initiatives to prevent and treat HIV/AIDS and provides decision makers with relevant data; the agency also fights against HIV/AIDS discrimination. The agency also focuses on the prevention, control, and treatment of communicable ad noncommunicable diseases; maintains veterinary public health units; and manages the division of Sustainable Development and Environmental Health (SDE), which addresses relationships between environment and health. SEE ALSO: AIDS; Immunization/Vaccination; World
Health Organization (WHO).
Bibliography. Joseph J. Fins, “PAHO’s progress. (Pan Amer-
ican Health Organization to establish the Pan American Insti-
tute of Bioethics),” The Hastings Center Report (v.23/2, 1993); Pan American Health Organization, www.paho.org. Kelly Boyer Sagert Independent Scholar
Pancreas Transplantation Pancreas transplantation is a surgical procedure whereby a pancreas is removed from a cadaveric donor and implanted into a recipient. Often, comorbidities require simultaneous pancreas/kidney transplantation; this procedure comprises 78 percent of all reported pancreas transplants performed in the United States between 1987 and 2002. While sometimes indicated for patients suffering type 2 diabetes mellitus (DM), pancreas transplantation is primarily used to treat patients with type 1 DM, with or without end-stage renal disease (ESRD). The pancreas transplant was pioneered in 1966 by physicians at the University of Minnesota during a combined pancreas/kidney transplant procedure. Since then, improvements in allograft survival are attributed to better immunosuppressant therapies and advanced technical knowledge. Potential pancreas recipients are identified by a team of specialists including endocrinologists, transplant surgeons, and nurses. After ruling out contraindications of active infection, history of malignancy, or HIV, patients are subject to a detailed medical assessment. Immunologic status, blood type, basic blood chemistry, and serologies are each evaluated for transplant suitability. Because patients requiring a pancreas transplant may wait for months or years before receiving their organ, these tests are repeated periodically to ensure that no significant changes have occurred since the initial evaluation. When a donor pancreas becomes available, procurement can be completed via one of several surgical methods depending on the specific donor’s anatomy and whether other organs are being harvested simultaneously. All cadaveric pancreas procurements involve a long midline incision necessary to expose both the thoracic and abdominal cavities and rule out malignancy. The majority of pancreatic surgical dissection is then performed before or after a systemic flush of the donor’s
blood with cold preservation solution. To ensure the organ is perfused with preservation solution, the main blood vessels to and from the pancreas are the last to be transected. Additionally, a small section of the duodenum (part of the small intestine) attached to the pancreatic duct is dissected prior to removal of the pancreas. Once recovered, the pancreas is immersed in a container of preservation solution before being packaged on ice for transport to the recipient. Like procurement, implantation may be accomplished in several ways. While arterial blood flow is typically restored via the iliac artery, venous drainage may either occur through the iliac vein or the hepatic portal system. Because hyperinsulinemia (high levels of insulin in the blood) may result when venous drainage bypasses the liver, the portal drainage option has a theoretical advantage. The pancreatic duct and duodenal segment are sewn into either the bladder or a portion of the small intestine. Drainage into the bladder allows for assessment of pancreatic function through simple urine tests but may cause pancreatitis. Risks of small bowel drainage include obstruction and infection. The successful transplant leads to the normalization of blood glucose levels through endogenous insulin secretion. Following the successful procedure, recipients begin lifelong regimens of immunosuppressive therapy. Patient follow-up with the transplant team is vital to prevent and address complications of thrombosis, graft rejection, metabolism issues, and infection. Despite these risks, pancreas transplantation remains the best available treatment option for type 1 DM and has seen vast improvements since its inception four decades ago. SEE ALSO: Allograft; Immunosupression; Organ Dona-
tion; Organ Transplantation; United Network for Organ Sharing (UNOS).
Bibliography. G. W. Burke, G. Ciancio, and H. W. Sollinger, “Advances in Pancreas Transplantation,” Transplantation (v.77/9 Suppl, 2004); C. E. Freise, et al., “Simultaneous Pancreas-Kidney Transplantation: An Overview of Indications, Complications and Outcomes,” Western Journal of Medicine (v.170, 1999); J. L. Larsen, “Pancreas Transplantation: Indications and Consequences,” Endocrine Reviews (v.25, 2004); R. P. Robertson, et al., “Pancreas
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and Islet Transplantation for Patients with Diabetes,” Diabetes Care (v.23/1, 2000). Jason Palmatier Independent Scholar
Pancreatic Cancer Pancreatic cancer is a tumor that occurs within the pancreas. It is the fourth leading cause of cancer in the United States and affects over 33,000 individuals each year. The pancreas is a large gland located behind the stomach. It is anatomically divided into three sections: the head, the body, and the tail. Functionally, the pancreas is composed of two parts: the exocrine pancreas and the endocrine pancreas. The cells that make up the exocrine portion of the pancreas have different functions. Some of these cells produce pancreatic fluid that contains complex structures, or enzymes, which digest fats and proteins. A smaller number of cells make up the endocrine gland, which produce hormones, such as insulin, glucagon, and somatostatin. These hormones maintain and regulate blood sugar levels. It is from these two glands that either malignant (cancers that can spread) or benign (cancers that cannot spread) tumors arise. The majority of malignant pancreatic cancers arise from the exocrine gland. Approximately 95 percent of the cancers develop from the glandular lining, and are known as adenocarcinomas. Most adenocarcinomas are found in the head and neck of the pancreas. The tumors of the endocrine pancreas are usually benign and much less common. Early clinical diagnosis of pancreatic cancer is difficult because the initial symptoms can be nonspecific. Frequent symptoms include abdominal pain, loss of appetite, weight loss, and jaundice. Furthermore, the expression of these symptoms may differ depending on the location of the primary tumor. Typically, the pain associated with pancreatic cancer is located in the upper abdomen and radiates to the back. This pain is more commonly associated with tumors arising from the tail of the pancreas and signifies spread of cancer to the nerves around the gland. Loss of appetite may contribute to extreme weight loss, especially when the tumor is located in the head of the
1328 Pancreatic Cancer pancreas. Weight loss may also occur when there is obstruction of the pancreatic duct, or the tube connecting the pancreas to the small intestine. This may cause pancreatic insufficiency, which can lead to fat malabsorption, diarrhea, and fatty stools. Persons with jaundice present with yellowing of the skin and of their eyes. Jaundice occurs when the pancreatic tumor obstructs the common bile duct, which is a tube that carries secretions from the pancreas. The obstruction prevents bile, a fluid that emulsifies fat, from reaching the small intestines. This subsequently leads to elevated levels of bilirubin, the main constituent of bile, in the blood. Obstructive jaundice can also lead to other signs, such as dark urine, light-colored stools, and localized itching. Additional signs and symptoms of pancreatic cancer include depression, palpable gallbladder, and an enlarged liver. There are several factors that are associated with an increased risk of acquiring pancreatic cancer. These include demographic variables such as increasing age, male gender, and the African-American race. Furthermore, smoking, obesity, a diet high in red meat and pork, diabetes, pancreatitis, occupational exposure to pesticides, and family history also play a role in the development of pancreatic cancer. Diagnosis of pancreatic cancer is usually made from information obtained through a history and physical as well as diagnostic tests. If the clinical suspicion based on various signs and symptoms are high, then several studies may be ordered. Laboratory tests in persons with pancreatic cancer may reveal elevated liver function tests and bilirubin. A tumor marker, CA 19-9, is usually elevated in individuals with pancreatic cancer. However, this test is not routinely used in the diagnosis of pancreatic cancer; rather, it is used to monitor the progression of the disease. Several imaging studies can be performed to identify as well as stage pancreatic tumors. Patients who present with jaundice frequently obtain an ultrasound of the abdomen. This technique uses sound waves to acquire images of internal organs, such as the pancreas, and can identify an obstruction or blockage of the bile duct system if one should exist. A computed tomography (CT) scan of the abdomen may be the initial test performed if one presents with signs of abdominal pain or weight loss without jaundice. A CT scan produces widespread
cross-sectional images of different areas of the body. This test can illustrate the size, location, and the site of spread to other organs, or metastasis, of the primary tumor. Moreover, an unknown mass in the pancreas may be biopsied under the guidance of a CT scan. A biopsy is performed when a small portion of a mass is excised and then examined under a microscope. This process determines if the mass is malignant or benign. There are many other imaging tests that can be performed, along with an abdominal ultrasound and CT scan, which can help reveal treatment options. The extent of treatment and prognosis depend on the staging of pancreatic cancer, which is based on the “tumor, nodes, and metastasis” (TNM) staging system. This classification is based on the extent of infiltration, spread of cancer to adjacent lymph nodes and the spread of cancer to distant organs. The final staging is usually assessed during surgery, and a formal stage between I to IV is assigned. Stage I pancreatic cancer is the least advanced and stage IV pancreatic cancer is the most advanced. Once the stage has been designated, then treatment options can be discussed. For cancers that have not spread significantly or for those who can tolerate the stress of an operation, removal of the tumor by surgical means is the best option. This can be done by laparoscopic methods, where a camera is inserted into the abdomen to facilitate removal of the tumor, or by open surgeries that remove the head, body, or tail of the pancreas, depending on where the tumor lies. Removal of the whole pancreas, or total pancreatectomy, is rarely done today. Additional treatment options include radiation and chemotherapy. Radiation therapy uses highpower rays to reduce and eradicate cancer cells in and around the tumor bed. Radiation therapy can be administered before or after surgery. In addition, it can be used in those where surgery is not an option due to poor health status or advanced stage of the disease. Chemotherapy utilizes various drugs to reduce or kill the cancer cells. These drugs can reach the bloodstream and thereby generate a systemic effect to the cells that have spread to other areas of the body. The most common drugs used are gemcitabine or a combination of 5-fluorouracil and leucovorin. The prognosis for pancreatic cancer is very poor because the lack of specific signs and symptoms contribute
Pancreatic Diseases
to a delay in diagnosis. Thus, the initial diagnosis may present as metastatic disease. The five-year survival rate for pancreatic cancer is less than 5 percent. Although pancreatic cancer is associated with a very poor prognosis, preventative measures can be taken to avoid development of this disease process. The most recommended method of prevention is to avoid the multiple risk factors associated with pancreatic cancer. This includes cessation of cigarette smoking, maintaining a healthy diet and weight, and by decreasing the consumption of red meat and pork. SEE ALSO: Cancer (General); Cancer Alternative Therapy;
Cancer Chemotherapy; Cancer Radiation Therapy; Gastroenterology; Oncology; Pancreatic Diseases.
Bibliography. American Cancer Society, “Cancer Facts
& Figures Sheets: Pancreatic Cancer,” www.cancer.org (cited April 2007); American Cancer Society, “Overview: Pancreatic Cancer,” www.cancer.org (cited April 2007); Lawrence R. Coia and David J. Moylan, Introduction to Clinical Radiation Oncology, 3rd ed. (Williams and Wilkins, 1998); Richard A. Erickson, “Pancreatic Cancer,” www.emedicine. com (cited December 2005); Vinay K. Kumar, Abdul K. Abbas, and Nelson Fausto, Pathologic Basis of Disease, 7th ed. (Elsevier Saunders, 2005); Pancreatica, “Confronting Pancreatic Cancer,” www.pancreatica.org (cited April 2007); David P. Ryan and Micheal L. Steer, “Patient Information: Pancreatic Cancer,” www.utdol.com (cited May 2006); Michael L. Steer, “Clinical Manifestations, Diagnosis, and Surgical Staging of Exocrine Pancreatic Cancer,” www.utdol.com (cited December 2006). Angela Garner, M.D. Manpreet Bedi University of Missouri–Kansas City
Pancreatic Diseases There are a number of pancreatic disorders that may be detected by using ultra sound scanning machines to examine the abdomen. Tests to measure the levels of pancreatic enzymes in the blood or in the duodenum give results that can be used for accurate diagno-
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sis of a pancreatic disorder. The pancreas can also be examined with endoscopic procedures. The most common pancreatic disorder is diabetes mellitus. Other pancreatic disorders can be genetics disorders or autoimmune disorders, or disorders caused by infection, poisons, drugs, alcohol abuse, tumors, trauma, cancer or they may be idiopathic. Diabetes is classified as either Type 1 Diabetes or as Type 2 Diabetes. Type 1 Diabetes occurs when the pancreas suddenly stops or dramatically slows the manufacture of insulin. It is commonly called juvenile diabetes because it often begins in childhood. Type 1 Diabetes is usually caused by a virus or some immune system dysfunction that in effect “kills” the islets. Young adults may also develop this form of diabetes. It can be managed with insulin, diet and exercise. Type 2 Diabetes is commonly associated with middle age onset in families with a history of diabetes. In many cases keeping body weight in normal limits, regular exercise and an appropriate diet can keep blood sugar levels under control. Diabetics should eat a diet that contain limited carbohydrates in complex forms; eliminate as much sugar as practical; avoid alcohol; have plenty of vegetables and appropriate levels of lean meats. The American Diabetic Association has created cook books for diabetics and other useful literature. There is a wide array of medicines available for diabetics that can either stimulate the pancreas’ islets to produce more insulin or that promote the red blood cells to utilize insulin more effectively. Sulfonylureas, D-phenylalanine deratives and meglitinides stimulate the pancreas to make more insulin. Biguanides reduce the glucose made by the liver. The alpha-glucosidase inhibitory slows the absorption of starches. Thiazolidinediones increases sensitivity to insulin. Diabetes and pancreatitis are considered risk factors for the development of pancreatic cancer. It is however, rarely the cause of pancreatitis. Chemotherapeutic agents L-asparaginase and azathioprine can contribute to the development of pancreatitis in cancer patients. Diabetes is a growing health problem in the United States. The consumption of fat-laden fast foods, excessive quantities, poor nutritional habits, excessive consumption of food, and a general lack of exercise are contributing to an enormous increase in obesity in all ages and across most ethnic groups. Frequently the results are an increase in the onset of diabetes. Children
1330 Pancreatic Diseases that are grossly overweight are prone to developing juvenile diabetes. The long term health effects are greatly increased health risks, health costs, and shortened life spans. The problem is spreading globally and rivals the number of people who lack enough to eat. Pancreatitis is an inflammation of the pancreas. It is very painful and can be fatal if not treated properly. It normally takes weeks to recover from an attack. Normally the pancreas secretes digestive enzymes into the small intestine through the pancreatic duct. It also releases the hormones insulin and glucagons into the bloodstream. Normally the digestive enzymes are not activated until they reach the small intestines. However, this process is disrupted when pancreatitis occurs. The digestive enzymes become active inside the pancreas and begin to digest it. Pancreatitis can occur in either acute or chronic forms. Acute pancreatitis usually has a sudden onset and lasts only a short period of time. It usually resolves to normal functioning. In contrast chronic pancreatitis does not resolve itself which results in the pancreas slowly destroying itself. Both acute pancreatitis and chronic pancreatitis are serious conditions. Cases of either can have serious complications, which can include tissue damage, infection, bleeding and the formation of pseudocysts. Tissue destroyed by the enzymes may become debris available for infection and fluids may accumulate. In some cases the digestive enzymes and toxins may enter the blood stream where they eventually reach the heart, lungs, kidneys and other organs. Acute pancreatitis is usually caused by gallstones blocking the bile duct. Or it is caused by the excessive consumption of alcohol. Or the cause may ultimately be idiopathic. More men experience acute pancreatitis than women. Symptoms of acute pancreatitis normally begin with pain in the upper abdomen which may come and go. At times it may be intense. The person may also look ill and feel sick. The pain in the stomach may make the abdomen tender. Other symptoms include low blood pressure, rapid pulse, nausea, vomiting and fever. Dehydration is likely to be present in severe cases. Bleeding may occur in the pancreas leading to shock and death. Pancreatitis can be diagnosed with blood tests that show elevated levels of amylase and lipase, the digestive enzymes. There may also be changes in the normal levels of blood glucose, calcium, magnesium, sodium,
potassium and bicarbonate. If the pancreas resolves to its normal functioning these all return to their normal levels. Abdominal ultrasound examinations or CAT scans can be used to diagnose inflammation or enzyme damage to the pancreas. CAT scans can also identify pseudocysts or gall stones. If acute pancreatitis is not properly treated it can become chronic pancreatitis with extensive damage to the pancreas and surrounding tissues. Most cases of chronic pancreatitis are caused by alcohol abuse. However, some cases are triggered by an acute attack, especially if the pancreatic ducts are damaged. The attack causes scaring, inflammation that is difficult to treat, and destroyed tissue. Congenital or hereditary pancreatitis normally starts in childhood if a child has inherited neurovisceral porphyrias and related metabolic disorders. Hereditary pancreatic problems may take years to diagnose because the symptoms are episodic. Family medical histories in which there have been cases of pancreatitis in two or more family members over two or more generations are indicators of a genetic problem. Treatment is usually the same as in cases of acute pancreatitis. Surgery may also be an aid to pain relief and to the prevention of complications. Hereditary pancreatitis can be due to problems in the porphyrim pathway. If the problems keep reoccurring they can indicate that there is a genetic disorder. Hepatic prophyrias results from the overproduction of porphyrins which are chemicals that are eventually used to make enzymes. Symptoms can include skin problems or neurological complications. Children usually do not have chronic pancreatitis unless they have hereditary pancreatitis. However, cystic fibrosis may also ultimately affect their pancreas and cause pancreatitis. Trauma to the pancreas can cause pancreatitis in both children and adults. The most common cause of trauma is penetrating trauma cause by gunshot or stab wounds. High mortality rates occur when the trauma is in the proximity of the head of the pancreas. Shock, massive hemorrhage, damage to the ducts and a lack of surgical treatment can lead to death. Vehicular accidents are a common form of pancreatic trauma. It is most likely to occur if the driver is not wearing a seat belt and is thrown against the steering wheel. Accidents among children who are struck in the stomach with bicycle handlebars are also a cause.
Papua New Guinea
In cases of pancreatic trauma a common complication is the development of pancreatic fistulas. Serious duct injury may also be present as are pseudocysts. Surgery is usually necessary. Some medicines have been reported as the cause of pancreatitis. Some of the commonly reported medicines are AIDS drugs such as pentamidine, diuretics such as furosemide and hydrochlorothiazide (HTZ). Estrogen has also been implicated. Gut dysmotility may be caused by medicines that predispose the patient to attacks of pancreatitis. The pancreas can develop tumors for every type of tissue that is in the organ. Some are non-cancerous but others are. Pancreatic cancer is the fifth highest cause of cancer death around the world. Adenocarcinoma of the pancreas is the most common type of tumor. It is a very aggressive type of tumor that develops in the cells of the pancreatic duct. Life spans for patients rarely exceed five years. In the United States 30,000 new cases occur every year. See Also: Pancreatic Cancer; Pancreas Transplantation. Bibliography. Leslie H. Blumgart, Surgery of the Liver,
Biliary Tract and Pancreas (Saunders W. B Company, 2006); Markus W. Buchler, ed., Chronic Pancreatitis: Novel Concepts in Biology and Therapy (Blackwell Science, 2002); Chris E. Forsmark, ed., Pancreatitis and Its Complications (Springer-Verlag, 2004); Gregory G. Ginsberg, Clinician’s Guide to Pancreaticobiliary Disorders (SLAC, Inc., 2005); John M. Howard and Walter Hess, History of the Pancreas: Mysteries of a Hidden Organ (Springer-Verlag, 2002); Colin D. D. Johnson, Pancreatic Disease (Springer-Verlag, 2004); Bettina Rau, et al., Pancreas: A Clinical and Surgical Text (Blackwell Publishers, 2007); Gary Scheiner, Think Like a Pancreas: A User’s Guide to Managing Diabetes with Insulin (Avalon Publishing Group, 2004). Andrew J. Waskey Dalton State College
Papua New Guinea Papua New Guinea is an independent nation in the Pacific, sharing the large island of New Guinea with the Indonesian states of Papua and West Irian Jaya. Papua
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New Guinea is comprised of the eastern half of the island and many small off-shore islands. It is the most linguistically-diverse country in the world, with more than 850 different languages (one-tenth of the world's total) and about as many different indigenous groups. Most of the country is covered by rainforest and volcanic mountains, including 4,500-meter Mt Wilhelm. The population is 5,800,000 and growing at 2.163 percent. The birth rate is 28.76 births per 1,000 and the death rate is 7.14 per 1,000. Median age is 21.4 years. Life expectancy is 63.41 years for males and 67.95 years for females. Gross national income is $580 per person, with 37 percent living in poverty. Although the country has ample natural resources, the difficult terrain makes it hard to access, and 85 percent of population sticks to agriculture. Unemployment ranges from 2 to 80 percent depending on the region. Only 13 percent of Papua New Guineans live in urban areas. Papua New Guinea was making great strides in reducing its communicable disease burden until the 1990s, at which point progress stalled. Today, communicable diseases are responsible for half of all mortality in the country. Malaria is endemic, and along with pneumonia, is the cause the majority of hospital admissions and of a third of recorded deaths. Most of the country lacks potable water and sanitation. This leads to a high risk for diarrhea and other intestinal disorders, typhoid fever, and other illnesses. There were 400,000 cases of Hepatitis B diagnosed in 2002 alone. The country is one of four nations in the region dealing with a generalized AIDS epidemic (along with Thailand, Cambodia, and Myanmar). The adult prevalence rate is 1.8 percent, with 60,000 believed to be infected. Most AIDS patients are heterosexuals between the ages of 20 and 40, and more than half are women. Early introduction to sexual activity and multiple partners are culturally acceptable, and combined with a high level of violence and coercion against women, creates a perfect environment for the virus to spread. The tuberculosis rate is also high, with 448 cases per 100,000 and a 58 percent cure rate. Non-communicable diseases are taking a toll on the health of residents, with climbing rates of hypertension, diabetes, and cancers. Many of these stem from preventable causes, including widespread use of tobacco, alcohol, and poor diet. Lack of health knowledge among the people is an important factor in the
1332 Paraguay spread of both communicable and non-communicable disease. Efforts by officials to educate the people on things they can do to better their health tend to fall down at the local level. An average of 35 children under the age of 5 and 20 infants under the age of 1 die each day in Papua New Guinea, generally from malaria, diarrhea, pneumonia, or measles. Weakening as a result of malnutrition is believed to be a contributory cause in many of these deaths, with an estimated 30 percent of children under age 5 lacking vital nutrients in their diets. Half of school-age children do not attend classes, and of those that do, 60 percent do not finish primary school. Only 51 percent of women are literate. Contraceptive use is low, at 9 percent, and the total fertility rate is 3.79 children per woman. About 39 percent of births take place in a hospital; most children are born at home, with complications leading to a maternal mortality rate of 330 deaths per 100,000 live births. Papua New Guinea has a public and private health system, with much of the private system in the hands of various religious groups (66 percent of Papua New Guineas belong to Catholic or Protestant denominations). Church-run rural clinics are often better staffed and maintained than state-run clinics. SEE ALSO: Birth Rate; Healthcare, Asia and Oceania. Bibliography. "A guide to statistical information at
WHO," World Health Organization. www.who.int/whosis/ en/index.html (cited June 2007); "Country Health Profile: Papua New Guinea," WHO/Western Pacific Regional Office. www.wpro.who.int/countries/png/ (cited June 2007); "Papua New Guinea," CIA World Factbook. www.cia.gov/library/publications/the-world-factbook/geos/pp.html (cited June 2007); “Papua New Guinea (04/07),” US Department of State. www.state.gov/r/pa/ei/bgn/2797.htm (cited June 2007); “Papua New Guinea,” UNAIDS: The Joint United Nations Programme on HIV/AIDS. www.unaids.org/en/Regions_Countries/Countries/papua_new_guinea.asp (cited June 2007); “UNICEF Papua New Guinea,” UNICEF. www. unicef.org/png/index.html (cited June 2007); “WHO Global InfoBase: InfoBase Home Page,” World Health Organization. www.who.int/infobase/report.aspx (cited June 2007); Heather K. Michon Independent Scholar
Paraguay Paraguay is a landlocked republic located in South America, bordered by Brazil, Argentina and Bolivia. Its name means “from a great river,” meaning the Rio Paraná, which forms the border with Brazil. All of the country’s power comes from the hydroelectric plants along the Paraná, and it is also the world’s largest exporter of hydroelectric power. Paraguay became a Spanish colony in 1537 and declared independence in 1811. The country has a long history of political instability and fractious relations with neighbors and has struggled to find a firm economic foundation for its citizens. Paraguay has a current population of approximately 6,669,000 and is growing at a rate of 2.416 percent annually. The birth rate is 28.77 per 1,000 population and the death rate is 4.54 per 1,000 population. It is a young society, with the median age at 21.6 years. Life expectancy at birth is 72.78 years for males and 78.02 years for females. Infant mortality is 26.45 deaths per 1,000 births. The total fertility rate is 3.84 births per woman. Paraguay is highly urbanized, with 58 percent of the population living in the cities. Gross national income is $1280 per capita, and 16 percent of the population is estimated to live on $1 a day. Paraguay has to contend with a few serious communicable diseases. Chagas’ disease is among the most widespread problems, although control programs and careful survaillence seems to be reducing the number of infections. Cutaneous leishmaniasis is prevalent in agricultural areas. Cholera is not as much of a problem in Paraguay as in other parts of Latin America, but there are at least 40,000 cases of diarrhea each year, mostly in children under 5. Hantavirus emerged in the 1990s. There have also been considerable gains in disease control. Malaria has not been eradicated, but it is no longer epidemic. After a serious outbreak of dengue fever in 1988-89, it has been seen infrequently, although the vector is still present throughout the country. Measles, which once reached epidemic status once every three years or so, has been brought under control. The country has been polio free since 1985. The prevalence rate for HIV/AIDS is 0.4 percent, with an estimated 13,000 cases and slightly over 500 deaths so far. Good epidemiological information is scarce, so it is difficult to assess the spread of the virus. Most cases seem to involve heterosexual contact
Paralysis
in people between the ages of 15-24, and is concentrated in the capital city of Asunción and the border regions. Aside from cardiovascular disease and cancers, accidents and violence are leading causes hospitalization and death in Paraguay. One survey in the 1990s found that accidents and violence were most common in the young, with 58 percent of victims between the ages of 15-24 and 80 percent of them male. In Alto Paraná, the region along the Brazilian border, accidents and homicides were the second and third-leading cause of death in the late 1990s. One in every five homicides occurred in this district. Paraguay has both a public and private healthcare sector, and there has been significant growth in private healthcare since the mid1990s. Coordination of health policy is the responsibility of the Ministry of Public Health and Social Welfare. Government expenditures on healthcare constitute 7.7 percent of the annual gross domestic product. Paraguay spends $88 per capita. SEE ALSO: Child Safety; Healthcare, South America.
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Bibliography. “Paraguay”. Health in the Americas, 1998. http://www.paho.org/english/HIA1998/Paraguay. pdf (accessed June 2007); “Paraguay”. UNAIDS: The Joint United Nations Programme on HIV/AIDS. http://www. unaids.org/en/Regions_Countries/Countries/paraguay. asp (accessed June 13, 2007); “United Nations Children’s Fund, “At a glance: Paraguay—Statistics,” http://www. unicef.org/infobycountry/paraguay_statistics.html#28 (cited June 2007).
Heather K. Michon Independent Scholar
Paralysis Paralysis is an illness in which a person loses the ability to sense or move. When a nerve fails to send its impulses to a muscle, the muscular activity begins to atrophy. As a result of this miscommunication at the neuromuscular junction in a patient’s body, he or
Paralysis can occur suddenly or over time as it spreads. Stroke or trauma is the most frequent cause of a sudden paralysis. Accidents that lead to spinal cord injuries give rise to a serious and an irreversible form of paralysis.
1334 Paralysis she ultimately may loose his or her movement and sensation functions. Paralysis can be characterized in different types. For example, it can be temporary or permanent, partial or complete, widespread or localized. Moreover, paralysis can occur suddenly or over time as it spreads. Stroke or trauma is the most frequent cause of a sudden paralysis. Accidents that lead to spinal cord injuries give rise to serious and an irreversible form of paralysis. Paraplegia, hemiplegia, hemiparesis, quadriplegia, and stroke are some examples of different categories of paralysis. Paraplegia Paraplegia is known as the paralysis of the legs as it affects the patient’s lower extremities. It usually originates from the lower spinal cord injury. A person typically becomes paraplegic due to a broken back from an accident or by having congenital diseases that is passed on. Spina bifida and polyneuropathy are examples of commonly seen congenital disorders that are associated with a paraplegic condition. A tumor might also result in this type of paralysis. The good news is that there is a possibility for the nerves to be back in action if the spinal cord is not severely affected. However, chances become low as more time passes with no sensation felt in the lower part of a patient’s body. Other symptoms in addition to paralysis include problems with bladder and bowel control, limp arm and leg muscles, sexual dysfunction, difficulty breathing, numbness, tingling, and pain. A paraplegic patient may also experience difficulty in conducting central nervous system activities such as speech, vision, or balance. Physicians diagnose paraplegia through a physical examination. Additional procedures such as a blood test, magnetic resonance imaging (MRI), computed tomography (CT) scan, or an X-ray may also be ordered to confirm the diagnosis. Also, each paraplegia case is different depending on where on the spinal cord the injury has occurred. Hence, each case will also have a different strategy for diagnosis and treatment. The physician dealing with a paraplegic patient would usually aim to stabilize the injured spine by restoring proper alignment and expanding the affected nerves.
To do so, a patient is often assigned to a rehabilitation program that provides occupational and physical therapy. Additional specialty treatment may also be assigned depending on the severity of the case. A physician may offer to consult a speech therapist, a respiratory therapist, or a psychiatrist to provide a treatment plan for better recovery. Stroke A stroke strikes when blood flow in the brain either leaks out or is interrupted. This results in diminished nutrient and oxygen supply reaching the brain tissue, which in turn lowers the physical or mental functional activity of the brain. Additionally, strokes can be hemorrhagic, arising from a ruptured blood vessel or a leaking artery. Ischemic strokes are those that occur due to a blocked artery. It is a life-threatening condition that needs emergency medical attention. Strokes can often lead to weakness and paralysis on the opposite side of the damaged brain. Other symptoms include numbness or weakness in the face or legs, headache, difficulty speaking or understanding speech, confusion, tingling, memory loss, personality changes, depression, decreased sensation, loss of balance and orientation, and vision problems. Currently, there is no cure for stroke. A physician’s focus would remain on controlling the symptoms and increase the physical and mental functional ability of the patient. Other forms of paralysis include: • Quadriplegia is paralysis caused by spinal cord injury that affects both the upper and lower parts of the body. • Hemiplegia is paralysis of one side of the body, often caused after serious brain damage such as a stroke. • Weakness on one side of body with incomplete paralysis is known as hemiparesis. This also happens as an after effect of a stroke. • Partial paralysis of a body part occasionally associated with involuntary tremors gives rise to a condition known as palsy. SEE ALSO: Bladder Diseases; Spinal Cord Injuries; Stroke. Bibliography. American Medical Association Family Medical Guide, 4th ed. (Wiley, 2004); Martins S. Lipsky,
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ed., American Medical Association: Concise Medical Encyclopedia (Random House Reference, 2007). Jinal Mehta Independent Scholar
Parasitic Diseases The organism that harbors the parasite and suffers a loss caused by the parasite is a host. The host in which the parasite lives its adult and sexual stage is the definitive host, whereas the host in which a parasite lives as the larval and asexual stage is the intermediate host. Other hosts that harbor the parasite and thus ensure continuity of the parasite’s life cycle and act as additional sources of human infection are known as reservoir hosts. An organism (usually an insect) that is responsible for transmitting the parasitic infection is known as the vector. The parasite derives all benefits from association and the host may either not be harmed or may suffer the consequences of this association, a parasite disease. The parasite is termed obligate when it can live only in association with a host or it is classified as facultative when it can live in or on a host as well as in a free form. Parasites that live inside the body are termed endoparasites, whereas those that exist on the body surface are called ectoparasites. Parasites that cause harm to the host are pathogenic parasites, while those that benefit from the host without causing it any harm are known as commensals. Parasitology is the study of parasites, their hosts, and the relationship between them. As a biological discipline, the scope of parasitology is not determined by the organism or environment in question, but by their way of life. This means it forms a synthesis of other disciplines, and draws on techniques from fields such as cell biology, bioinformatics, molecular biology, immunology, genetics, and ecology. Medical Parasitology One of the largest fields in parasitology, medical parasitology is the study of those parasites that infect humans. These include organisms such as:
The eggs of the human parasite Enterobius vermicularis, or ‘’human pinworm,” captured on cellulose tape.
• Plasmodium spp., the unicellular organism that causes malaria • Leishmania donovani, the unicellular organism that causes leishmaniasis • multicellular organisms such as Schistosoma spp The study of medical parasitology is commonly conceived as limited to parasitic worms (helminths) and the protozoa. But others organisms, such as vectors (insects) and/or ectoparasites are usually included. In the protozoan are located the most important parasitic pathogens, such as those that cause malaria, but also many associated with a high morbidity in the intestinal tract. Of the many protozoa that can reside in the human gut, only the invasive strain of Entamoeba histolytica causes serious disease. This parasite, ingested in water contaminated with human feces containing viable cysts of E. histolytica, can cause the disease amebiasis, which in its most severe form is known as amebic dysentery. Another common waterborne intestinal protozoon is the flagellate Giardia lamblia/duodenalis/intestinalis, which causes giardiasis, a mild to occasionally serious or long-lasting diarrhea. Other flagellate parasites infect the human skin, bloodstream, brain, and viscera. The tsetse fly of Africa carries to humans the blood-infecting agents of trypanosomiasis, or African sleeping sickness, Trypanosoma brucei gambiense and T. brucei rhodesiense. The infection can be fatal if the parasites cross the bloodbrain barrier. In Latin America, the flagellate T. cruzi
1336 Parathyroid Disorders is the agent of Chagas’ disease, a major cause of debilitation and premature heart disease among those who are poorly housed. The infection is transmitted in the liquid feces of a conenose bug (genus Triatoma) and related insects. The infective material is thought to be scratched into the skin or rubbed in the eye, especially by sleeping children. Another group of parasitic flagellates includes the macrophage-infecting members of the genus Leishmania, which are transmitted by blood-sucking midges or sand flies. Cutaneous leishmaniasis is characterized by masses of infected macrophages in the skin, which induce long-lasting dermal lesions of varying form and severity. The broad spectrum of host–parasite interactions is well exemplified by leishmaniases. The various manifestations of the disease are the result of the particular species of agent and vector, the immunological status of the host, the presence or absence of reservoir hosts, and the pattern of exposure. It is also important to mention the ciliates and the sporozoans as protozoan pathogens. The former group is largely free living, with only a single species, Balantidium coli, parasitic in humans (and pigs). This large protozoon is found in the large intestine, where it can cause balantidiasis, an ulcerative disease. The sporozoans, on the other hand, are all parasitic and include many parasites of humans. The most important are the agents of malaria. Other disease agents are included in the genera Isospora, Sarcocystis, Cryptosporidium, and Toxoplasma. Pneumocystis, a major cause of death among persons with acquired immunodeficiency syndrome (AIDS), was formerly considered a protozoon of uncertain relationship, but now it is thought to be a member of the Fungi. SEE ALSO: Immunology; Giardia Infections; Medical Hel-
minthology; Travel Medicine.
Bibliography. Paul Beaver, Rodney Jung, and Eddie
Cupp, Clinical Parasitology (Lea & Febiger, 1984); Gordon Cook and Alimuddin Zulma, Manson’s Tropical Diseases (Saunders, 2003); Becerri Flores and Romero Cabello, Medical Parasitology (McGraw-Hill, 2004); David Heymann, Control of Communicable Diseases in Man (APHA/ PAHO/WHO, 2004); Jorge Homez, Parasitology (Editorial de LUZ, 1990); R. A. Lambert, Parasitology: Identification
of Helminthes (Butterworths, 1969); World Health Organization, Bench Aids for the Diagnosis of Intestinal Parasites (World Health Organization, 1994). Alfonso J. Rodriguez-Morales, M.D., M.Sc. Universidad de Los Andes Carlos Franco-Paredes, M.D., M.P.H. Emory University
Parathyroid Disorders Humans generally have four small parathyroid glands embedded behind their thyroid gland in the neck. Although this is the most common anatomic location, the parathyroid glands can be found in variable places in the neck. The primary function of the parathyroid glands are to secrete parathyroid hormone (PTH) which is synthesized and secreted by the chief cells of the gland. Parathyroid hormone is the body’s principle player in the balance of calcium; specifically, PTH functions to increase serum calcium and decrease serum phosphate. This effect is exerted through interactions of PTH with bone and the kidney. Unlike other glands in the endocrine system, the parathryoid is not under control from the pituitary gland but rather is responsive to the plasma concentration of ionized calcum: a decrease in serum calcium stimulates PTH production. Disorders of the parathyroid gland can be categorized as conditions that cause hyperparathyroidsm (increased PTH and serum calcium) and hypoparathyroidsm (decreased PTH and serum calcium). Hyperparathyroidism Primary (originating from the parathyroid gland) hyperparathyroidism is most often caused by a parathyroid adenoma (generally benign). Carcinoma of parathyroid gland is quite rare. Parathyroid adenomas can be seen in isolation or as a component of the multiple endocrine neoplasia syndromes (MEN) I or IIa. Clinically, primary hyperparathyroidism can lead to metastatic calcification in soft tissues and calcium stone formation in the kidneys. Further, increased levels of PTH and the resultant hypercalcemia can predispose to peptic ulcers. Secondary hyperparathyroidism is usually caused by advanced kidney disease. Inability of the failing kidney to excrete phosphorus leads to
increased levels of phosphorus in the serum and decreased levels of calcium both of which are a signal for PTH production and release. The parathyroids, under constant stimulation from these electrolyte abnormalities, undergo hyperplasia (growth in the number of cells). Tertiary hyperparathyroidism is persistent parathyroid hyperfunction in spite of correction of hypocalcemia in preexisting secondary hyperparathyroidism. It is often caused by the development of an adenoma in a previously hyperplastic gland. Hyperparathyroidism may also arise from enzyme deficiencies that are involved in the processing of vitamin D. A discussion of hyperparathyroidism is not complete without a discussion of hypercalcemia, given the direct relationship between PTH levels and serum calcium levels. Increased levels of serum calcium can be associated with bone pain, kidney stone formation, stomach pain, and psychiatric disturbances. Although rare in cases of parathyroid dysfunction, acutely high levels of calcium necessitate immediate hydration. After hydration and volume restoration is performed, calcium excretion can be achieved with the use of loop diuretics such as furosemide. Parathyroid adenomas can be removed by endocrine surgeons; however, it is prudent to watch serum calcium levels in the postoperative period. Hypoparathryroidism Hypoparathryroidism is most commonly caused by accidental surgical excision during removal of the thyroid gland. Care must be taken intraoperatively to identify the parathyroid glands at the time of surgery. Absence of the parathyroid glands may be seen with the congenital disorder DiGeorge syndrome, which is associated with thymic hypoplasia and deletion of chromosome 22q11. Hypoparathyroidism manifests as hypocalcemia. Hypocalcemia can lead to increased neuromuscular excitability and tetany (prolonged, sustained contraction of muscle). This can be tested for in a person with suspected hypocalcemia with the use of Chvostek’s sign and Trousseau’s sign. The Chvostek maneuver includes tapping the cheek to check for spasm of the muscles of mastication (chewing). Trousseau’s maneuver involves inflating a blood pressure cuff over an upper extremity and checking for spasms of muscle movement (referred to as carpo-
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pedal spasms). Treatment of hypocalcemia includes prompt and careful replacement of serum calcium usually intravenously. Diagnosis and Treatment Parathyroid disorders are generally diagnosed with simple blood tests. Usually the clue to parathyroid disorder is an elevation in serum calcium. This usually leads to checking the amount of intact-PTH (iPTH) in the serum. Intact-PTH is not to be confused with PTH-like hormone (PTH-rp), a substance that is commonly produced by nonparathyroid tumors such as squamous cell carcinoma of the lung or renal cell carcinoma. Further information may be pursued through the use of X-rays to determine the status of the bones. As aforementioned, surgical removal remains an option for hyperfunctioning parathyroid glands, but treatment plans are often individualized according to the patient’s age, medical condition, and the causation for parathyroid disorder. Treatment for hypoparathyroidism usually involves either vitamin D (calciferol) or a medicine known as alfacalcidol, which is converted to a form of vitamin D in vivo. Parathyroid hormone cannot be used in treatment. With either medicine, the blood calcium level must be checked regularly in the early months of treatment as their effects may not take place for a number of weeks. It is also important to record and observe any coexisting medicines that the treated patient is taking as they may affect the efficacy of vitamin D therapy. SEE ALSO: Calcium; Thyroid. Bibliography. A. K. Ryan, et al., “Spectrum of Clinical
Features Associated with Interstitial Chromosome 22q11 Deletions: A European Collaborative Study,” Journal of Medical Genetics (v.34/10, 1997); F. Urbano, “Clinical Signs: Hypocalcemia,” in Hospital Physician (v.43/5 , 2000); R. W. Downs, “Hypocalcemia and Hypoparathyroidism,” in Current Therapy in Endocrinology and Metabolism, 4th ed. (1991); C. L. Janson and J. A. Marx, “Fluid and Electrolyte Balance,” in Concepts and Clinical Practice, 3rd ed. (1992); P. M. Reber and H. Heath, “Hypocalcemic Emergencies,” Medical Clinics of North America (v.79/1, 1995). Anil Seetharam, M.D. Washington University in St. Louis
1338 Parkinson, James
Parkinson, James (1755–1824) Born on April 11, 1755, in London, England, to surgeon John Parkinson and his wife, James Parkinson is best known for his 1817 “Essay on the Shaking Palsy” that shared information about the medical condition now called Parkinson’s disease. He is less known for his contributions to paleontology and his role in establishing it as a scientific endeavor. Parkinson studied medicine at the London Hospital Medical College for six months, receiving instruction in Greek, Latin, shorthand, and philosophy. He then served as an apprentice to his father for six years. During that time, he married Mary Dale (1781) with whom he had six children. In 1784, he became a physician, working from his home. His first acclaim occurred when he and his father worked to resuscitate a man who had hanged himself and Parkinson is perhaps the first to record details of a death occurring from a perforated appendix. Parkinson also became known for his work with the mentally ill and impoverished. In 1799, Parkinson began publishing Medical Admonitions, containing health-related information. He published material on numerous subjects that interested him, including lightning, memory problems versus insanity, government reform for the mentally ill, gout, and medical education. Parkinson also advocated for controversial social reform and political causes in a time when the king ruled absolutely. Using a pen name (Old Hubert), Parkinson criticized the government and championed the notion of the representation of the people in the House of Commons. Through Old Hubert’s pamphlets, he drew attention to the issues of poverty, prison conditions, unfair taxation, and neglect of the older population. Parkinson served as a witness for the defense when several men were accused of attempting to assassinate King George III. He took great personal risk when defending the accused, as they were charged with high treason in an era when punishment was severe. In his “Essay of the Shaking Palsy,” Parkinson described the symptoms of people afflicted with a common ailment. He hoped that his writing would focus attention on the disease; about six decades later, Dr. Jean Martin Charcot officially named it after James Parkinson. In 1822, Parkinson received the first Honorary
Gold Medal of the Royal College of Surgeons. He died on December 21, 1824. SEE ALSO: Movement Disorders; Parkinson’s Disease. Bibliography. “Dr. James Parkinson,” European Parkin-
son’s Disease Association, www.epda.eu.com/worldPDDay/ worldPDDay-JP.shtm (cited May 2007); “Dr. James Parkinson,” Parkinson’s Disease Society, www.parkinsons.org.uk/ Templates/Internal.asp?NodeID=98698 (cited May 2007). Kelly Boyer Sagert Independent Scholar
Parkinson’s Disease Parkinson’s disease (PD) is considered a hypokinetic movement disorder, as it results in a fundamental slowing of movement. It is most often idiopathic and the result of a degenerative process which leads to depletion of dopaminergic neurons. Both medical and surgical treatments work by relieving the symptoms caused by this loss of dopamine. Future therapies of PD will be geared at halting disease progression. The hallmark symptoms of PD include resting tremor, rigidity, and bradykinesia, as well as postural and gait disturbances. The tremor is often described as “pill-rolling” and gait as shuffling. Other symptoms include: • Poverty and slowness of movement (including face, i.e. masked facies) • Stooped posture • Reduced blink rate, impaired upgaze • Difficulty with alternating movements, micro graphia • Hypophonia, speech hurried and monotonous • Drooling, dysphagia, constipation • Dementia in 10 percent, depression Dyskinesias (i.e. hyperkinetic involuntary movements) are often present in PD; however, these movements are a result of medications and not of PD itself. Parkinson’s disease is generally idiopathic, though other etiologies including familial, post-encephalitic, drug-induced, and Parkinson’s Plus syndromes have been described. The onset generally occurs between 30-80 years of age with a peak between 50-70 years. The diagnosis is based on history and neurological
exam. PD is a degenerative process marked by a decrease in dopaminergic neurons in the basal ganglia. The basal ganglia (BG) are located in the telencephalon and consist of four interconnected nuclei: the striatum, globus pallidus (GP), substantia nigra (SN) and subthalamic nucleus (STN). The striatum is the main input of the BG; the internal segment of the GP (Gpi) and the pars reticulata of the SN (SNr) are the output nuclei. Output occurs either via a direct or an indirect pathway. In the direct pathway, the striatum projects to the GPi and SNr. In the indirect pathway, the striatum projects to the external segment of the globus pallidus, then to the STN, and ultimately to the GPi and SNr. The neurons involved in the direct pathway express the D1 subtype of the dopamine receptor (primarily excitatory), and in the indirect pathway express the D2 subtype of the dopamine receptor (primarily inhibitory). Both the direct and indirect pathways inhibit the thalamus, the relay station for sensory information en route to the cerebral cortex. In PD, the disruption of the motor circuit of this basal ganglia-thalamo-cortical network results in changes in neuronal rates of firing and activity patterns. The pathologic hallmark of PD is the loss of dopaminergic neurons in the SN with deposition of eosinophilic cytoplasmic inclusions called Lewy bodies. In normal aging, there are 425,000 of these dopaminergic neurons at age 20 and 200,000 at age 80. In PD, cell counts decrease to 100,000 and the SN appears pale and gliotic. The clinical symptomatology of PD results when dopamine loss exceeds approximately 60 percent. Dopamine denervation also results in a series of events within the basal ganglia that impairs its ability to appropriately interact with the rest of the nervous system. Medical treatment of PD is geared at replenishing dopamine. Medications often significantly relieve the majority of PD symptoms. Most commonly, treatment is with levodopa, a dopamine precursor, which is effective in 75 percent of PD patients. Levodopa is most beneficial in the treatment of bradykinesia and rigidity, and is given with carbidopa, a peripheral decarboxylase inhibitor, which limits its peripheral breakdown and thus increases the amount of drug which reaches the BG. However, over time the efficacy of levodopa may wane, requiring increased doses which often lead to the development of dyskinesias and motor fluctuations.
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Other medications, such as anticholinergics, dopamine agonists, catechol-O-methyltransferase (COMT) inhibitors, the antiviral amantadine, and the monoamine oxidase B (MAO-B) inhibitor rasagiline, may be employed with varying success. A subset of patients who have had PD for greater than 5 years and have responded to levodopa, but developed motor fluctuations are candidates for surgical treatment. Like medications, surgical treatments relieve symptoms and do not halt disease progression. Surgical interventions for movement disorders have been practiced for decades, beginning with lesions in the thalamus and basal ganglia. Thalamotomies and pallidotomies were most commonly performed. Thalamotomy was effective in reducing PD-associated tremor, while pallidotomy was effective in reducing the rigidity, hypokinesia, and tremor associated with PD. Because of an increased rate of complications when lesioning was performed on both sides, these procedures were generally performed unilaterally on the most symptomatic side. In the 1990s, the idea of deep brain stimulation (DBS) of targets in the BG was introduced. Early results of DBS revealed success in alleviating symptoms and improving the quality of life in patients with Parkinson’s disease. Bilateral DBS procedures were performed without the high incidence of side-effects associated with lesioning. Furthermore, DBS does not destroy tissue, thus allowing patients the opportunity to benefit from emerging therapies, and can also be customized to the individual patient over time by using different stimulation parameters and electrode contacts. Currently, DBS of the STN and GP are the most common procedures performed. Magnetic resonance imaging and neurophysiologically-guided localization of the appropriate target is employed and the surgeries are most often performed with patients awake to assess clinical response intra-operatively. Targets such as the STN arose through research in animal models. The gold standard of animal models for PD is considered to be the 1-methyl-4-phenyl1,2,3,6-tetrahydropyridine (MPTP) monkey model. Work in the MPTP-treated monkey led to the recognition that experimental lesions of the STN resulted in the reversal of contralateral akinesia, rigidity, and postural tremor. Animal studies in PD are on-going to further our understanding of the pathophysiology of the disease.
1340 Passive Immunity This research is augmented by information obtained from PD patients via functional imaging, such as PET and electrophysiological recordings during DBS surgeries. The ultimate goal of this research is to not only better understand/utilize neuroaugmentation, but also to develop modalities of treatment geared at halting disease progression. SEE ALSO: Brain Diseases; James Parkinson; Movement
Disorders; National Institute of Neurological Disorders and Stroke (NINDS); Neurologic Diseases (General); Tremor.
Bibliography. Lonneke M.L. de Lau and Monique M.B.
Breteler, “Epidemiology of Parkinson’s disease,” Lancet Neurol (v.5, 2006); Joseph Jankovic, “An Update on the Treatment of Parkinson’s Disease,” Mt Sinai J Med (v.73, 2006); John C. Morgan and Kapil D. Sethi, “Emerging Drugs for Parkinson’s Disease,” Expert Opin Emerg Drugs (v. 11, 2006); National Institute of Neurological Disorders and Stroke (NINDS), “NINDS Parkinson’s Disease Information,” www.ninds.nih.gov/disorders/parkinsons_disease/parkinsons_disease.htm (cited October 2006); William S Anderson and Frederick A Lenz, “Surgery Insight: Deep Brain Stimulation for MovementD,” Nat Clin Pract Neurol (v.2, 2006) David J. Brooks, “The Early Diagnosis of Parkinson’s Disease,” Ann Neurol (v.44, 1998); Yoland Smith, Mark D. Bevan, Eric Shink, and J. Paul Bolam, “Microcircuitry of the Direct and Indirect Pathways of the Basal Ganglia,” Neuroscience (v. 86, 1998); Hagai Bergman, ��������� Thomas Wichmann, and Mahlon R. DeLong, “Reversal of Experimental Parkinsonism by Lesions of the Subthalamic Nucleus,” Science (v.249, 1990). Julie Pilitsis, MD, PhD Rush University Medical Center, Chicago, Illinois Dino Samartzis, DSc, MSc, Dip. EBHC Harvard University, Erasmus University
Passive Immunity Passive immunity is achieved by the direct injection of antibodies or antiserum to defend against infection. This provides immediate, though temporary, protection from a specific disease-causing bacteria, virus or toxin to persons unable to produce antibodies. New-
born infants receive a natural passive immunity across the placenta; for the first few months of life, infants will have the same antibody protection as their mothers. Passive immunity is often provided by the administration of immune globulin with specific antibodies after exposure when there isn’t time for immunization and the development active immunity. In the case of Hepatitis B, the vaccination schedule takes place in three injections over a six-month period. If a person were exposed to Hepatitis B, the immune globulin would provide immediate protection. Immune globulin with specific antibodies can be administered to treat diseases normally prevented by immunization. As in the case of tetanus, Clostridium tetani, the bacterium causing the disease is ubiquitous in soil and in the event of a puncture wound may infect the wound and cause the disease in persons who haven’t been immunized. Passive immunity can be provided when active immunization isn’t practical or available. A situation when this would occur is after snakebite. Animal toxins are composed of proteins and because of this can produce an antibody response. The antiserum is made by immunizing animals with the venom to produce a variety of antibodies. When injected into a human after for example snakebite, the antibodies in the antivenin (or anti-venom) combine with the venom from the bite to render it ineffective. Different snakes produce different venoms, some are neurotoxic causing respiratory paralysis, or cytolitic, causing tissue and cell destruction. Serum from one person with specific antibodies can be given to another person who doesn’t have the antibodies, and the recipient will gain immunity for a short period of time, until the antibodies degrade. Intravenous Immune Globulin (IVIG) contains a wide variety of antibodies to provide a broad range of protection against illness. IVIG is produced with purification and viral inactivation from donated serum from a large pool of donors to contain millions of antibody specificities. Serum is the fluid in the blood containing the proteins with antibodies in three different globulins alpha, beta and gamma. Gamma globulin contains the most antibodies. Complications may arise from the administration of these injections. The administration of anti-venins or globulins produced in animals may cause anaphylaxis, anaphylactoid reactions or serum sickness (the deposit
Pasteur Institute
of antigen-antibody complexes most commonly in skin, joints, or the kidneys). Hypersensitive reactions are rare after administration of human immunoglobulins. See Also: Acquired Immunity; Rabies; Tetanus; Viral In-
fections.
Bibliography. New Ways to Boost the Body’s Defenses.
Arousing the Fury of the Immune System (Howard Hughes Medical Institute, 1998); Findlay E. Russell, “Toxic Effects of Animal Toxins,” Casarett & Doull’s Toxicology, 5th ed. (McGraw-Hill, 1996); Jeffrey L. Kishiyama, MD and Daniel C. Adelman, MD, “Allergic & Immunologic Disorders,” Current Medical Diagnosis and Treatment (Lange Medical Books, 2004). Lyn Michaud Independent Scholar
Pasteur Institute The Pasteur Institute, also known as the Institut Pasteur, is a nonprofit medical research organization dedicated to the study, treatment, and prevention of infectious diseases. Established by Dr. Louis Pasteur in June 1887, the Institute opened in November 1888 in a single building in a southwest suburb of Paris. Pasteur had become famous in the 1860s for his revolutionary work on germ theory and pasteurization, the process of heating foods to kill harmful bacteria and contaminants. Later, he moved into a long-term study of immunology and had developed several important vaccination protocols for animals and humans. In the 1880s, he was working on a vaccine for rabies when he decided to open an institute where scientists could come together to learn and teach. Pasteur gathered five prominent researchers to work with him at his Institute: Emile Duclaux, Charles Chamberland, Ilya Illyich Mechnikov, Joseph Grancher, and Emile Roux. All specialized in various aspects of microbes, and in 1889, Emile Roux taught his Cours de Microbie Technique, the first-ever academic course in the new field of microbiology. It was just the first in a staggering array of innovations and discoveries that came out of the Pasteur
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Institute in the coming decades. They solved many long-standing mysteries about the human immune system and how it interacted with the microbial world. Researchers isolated and studied the structure of diseases that were long the scourge of humankind and created vaccines to treat such killers as tuberculosis, diphtheria, tetanus, yellow fever, and hepatitis B. “Pasteurians,” as they were called, carried new research methods and techniques around the world. Today, the Pasteur Institute is one of the largest medical research organizations in the world and is almost unparalleled in its work on immunology, microbiology, and molecular biology. It maintains a global network of 29 affiliated institutes on five continents. The Paris campus, with 2,700 scientists and employees, is divided into 10 major research departments: Cell Biology and Infection, Developmental Biology, Genomes and Genetics, Immunology, Infection and Epidemiology, Microbiology, Neuroscience, Parasitology and Mycology, Structural Biology and Chemistry, and Virology. Every year, about 250 medical students and postgraduates from around the world come to the Pasteur Institute for advanced training in immunology and microbiology, and another 800 trainees come to perfect their laboratory skills. In 2005, the operating budget for the Institute was €205.5 million. To maintain its autonomy and objectivity, it derives its funding from several sources, including government subsidies, licensing fees, investments, and private donations. It also produces and distributes diagnostic tests through a branch of the French pharmaceutical firm Sanofi. Over the past several years, it has also provided start-up funding for 14 biotechnology companies whose work might complement that of the Institute. SEE ALSO: Genetics; Immunology; Infectious Diseases (General); Neuroscience; Parasitic Diseases; Virology. Bibliography. Jane Ackerman, Louis Pasteur: And the
Founding of Microbiology (Morgan Reynolds, 2004); Dorothy Porter, The History of Public Health and the Modern State (Editions Rodopi, 1994); Moira Reynolds, How Pasteur Changed History: The Story of Louis Pasteur and the Pasteur Institute (McGuinn & McGuire, 1994). Heather K. Michon Independent Scholar
1342 Pasteur, Louis
Pasteur, Louis (1822–95) Born on December 27, 1822, at Dole, Jura, France, Louis Pasteur founded microbiology as a science; disproved the theory of spontaneous generation, replacing it with germ theory of disease; discovered how to pasteurize liquids to prevent disease; and developed vaccines for anthrax and rabies. Pasteur attended the Collège Communal of Arbois, receiving his degree at Besançon. He then studied in Paris, researching properties of crystals. Through this research, he discovered the phenomenon of molecular dissymmetry. He married Marie Laurent, with whom he had five children. Three children died from typhoid fever. Named professor of physics at the Lycée de Dijon in 1848, just three months later, he became deputy professor of chemistry at the University of Strasbourg; he was named full professor in 1852. In 1854, he began serving as dean and professor of chemistry at the University of Lille. In 1857, he was chosen as director of scientific studies at the École Normale in Paris; six
years later, he became professor of geology and chemistry at the Ecole des Beaux Arts. From 1867 until 1889, he served as professor of chemistry at the Sorbonne and, finally, the director of the Pasteur Institute. Continuing his research, he discovered that germs caused fermentation, which disproved the concept of spontaneous generation and served as the impetus for the germ theory of infection. His studies of wine, beer, and vinegar allowed him to form his understanding of pasteurization in which liquids are partially sterilized to destroy organisms that can cause disease. Pasteur discovered the cause of silkworm disease and announced that the spread of the disease could be stopped if healthy worms were kept separate from diseased ones. Although he was mocked, he proved his theory and then moved on to study animal diseases. Discovering causes of anthrax and fowl cholera and finding methods to vaccinate against these diseases, Pasteur began studying childbed fever—now known to be caused by streptococcus—in humans in hospitals. He also researched rabies, discovering how to create a vaccinating virus for afflicted humans; because of this discovery, Germany founded the Pasteur Institute. In 1887, Pasteur was named Perpetual Secretary of the Academy of Science. He died on September 28, 1895. SEE ALSO: Pasteur Institute; Pasteurization. Bibliography. “Louis Pasteur,” New Advent Catholic En-
cyclopedia, www.newadvent.org/cathen/11536a.htm (cited March 2007); “Louis Pasteur,” Columbia Encyclopedia, 6th ed., www.bartleby.com/65/pa/Pasteur.html (cited April 2007). Kelly Boyer Sagert Independent Scholar
Pasteurization
Louis Pasteur founded microbiology as a science and discovered how to pasteurize liquids to prevent disease.
Pasteurization is a process in which liquids are heated to a specified temperature for a specified length of time to kill or retard the growth of bacteria and other disease-causing microorganisms. It is named for the French scientist Louis Pasteur, who along with Claude Bernard performed the first test of pasteurization in 1862. Although pasteurization is most familiar in its
Pathologist
application to milk today, Pasteur’s original work was concerned with the process of fermentation used in the wine industry. Pasteur established first that fermentation required the presence of yeast, and second that to prevent wine from souring, it should be heated after forming to about 122 degrees Fahrenheit (50 degrees Centigrade) to kill the yeast and allow the wine to age without spoiling. Pasteurized liquids are not sterilized, that is, they are not completely free of microbes; this is why, for instance, even pasteurized milk should be kept refrigerated to retard bacterial growth. Today, pasteurization is most often applied to milk, although it is also used for wine, fruit juice, and other liquids. The pasteurization process for milk is considered sufficiently important that it is mandated and regulated by national governmental agencies such as the Food and Drug Administration (FDA) in the United States and the Food Standards Agency in the United Kingdom. In the United States, all milk packaged for human consumption must be pasteurized if sold through interstate commerce, a regulation that has been in effect since 1987. However, private consumption of raw milk is not prohibited and some people believe it is more nutritious than pasteurized milk. The FDA does not recommend the consumption of raw milk because it may contain a variety of harmful bacteria (which would be killed by pasteurization), including Salmonella, E. coli O157:H7, Listeria, Campylobacter, and Brucella, which may cause serious illness or death. In addition, the FDA states that there are no known nutritional benefits to consuming raw, rather than pasteurized, milk. From 1998 to May 2005, the Centers for Disease Control and Prevention in the United States identified 45 outbreaks of foodborne illness traceable to unpasteurized milk or cheese made from unpasteurized milk, which produced over 1,000 illnesses, 104 hospitalizations, and 2 deaths; the actual count may be higher because many cases of foodborne illness are not reported. Two types of pasteurization are in common use for milk. High temperature/short-time (HTST) pasteurization is more common in the United States: this involves heating milk for 30 minutes to 145 degrees Fahrenheit (63 degrees Centigrade). Ultra-high temperature (UHT) pasteurization, which is common in Europe, requires heating milk to 280 degrees Fahrenheit (138 degrees Centigrade) for two seconds. UHT milk has a shelf life of six to nine months (unlike
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HTST milk, which requires refrigeration) but spoils more rapidly once the container is opened. SEE ALSO: Food and Drug Administration (FDA); Food
Contamination/Poisoning; Foodborne Diseases; Salmonella Infections. Bibliography. Patrice Debre, Louis Pasteur (Johns Hop-
kins University Press, 1998); U.S. Food and Drug Administration, “FDA and CDC Remind Consumers of the Dangers of Drinking Raw Milk,” press release P07-34, March 1, 2007, www.fda.gov/bbs/topics/NEWS/2007/NEW01576. html (cited March 2007). Sarah Boslaugh BJC HealthCare
Pathologist A pathologist is a medical doctor who is involved in pathology, the study and diagnosis of disease through the examination of molecules, cells, tissues, and organs. Although this covers a wide field, much of it is involved in the study of blood and other body fluids, and tissues. To train as a pathologist, doctors need to have completed a four-year medical degree, four years of medical school training, and between three to four years of postgraduate training. This may involve the study of anatomic pathology or clinical pathology, each of which requires certification by the American Board of Pathology. Many also tend to be osteopaths. In Britain, pathologists must have completed the undergraduate degree and then train in courses that have been approved by the Royal College of Pathologists, founded in 1962, involving training attachment, and also a series of examinations. Famous pathologists include the Scotsman Matthew Baillie who wrote Morbid Anatomy of Some of the Most Important Parts of the Human Body (1763); the French surgeon Guillaume, Baron Dupuytren who developed the surgical procedures for alleviating what became Dupuytren’s contracture; the German pathologist and politician Rudolf Virchow who was involved in pioneering work on cancer; the Briton, Sir Jonathan Hutchinson who was a pioneer in the
1344 Pathology study of congenital syphilis; the German pathologist Friedrich Daniel von Recklinghausen who worked on the degeneration of the skeleton; the Dane, Johannes Fibiger who received the Nobel Prize for Physiology or Medicine in 1926; and the Americans George Frederick Dick who devised the means of preventing scarlet fever and E. W. Goodpasture who spent most of his career in Tennessee. Mention should also be made of the fictional pathologist detective John Thorndyke who appears in the novels of the British physician and writer Richard Austin Freeman. SEE ALSO: Pathology. Bibliography. Royal College of Pathologists, www.rc-
path.org.uk (cited May 2007); Myer H. Salaman, Experiment and Interpretation: A Pathologist Reflects on Thirty Years of Cancer Research (Athlone, 1995). Justin Corfield Geelong Grammar School
Pathology Pathology is a both a science and the branch of conventional medicine that seeks to correctly understand and diagnose diseases. The term pathology describes the study of the effects of disease on bodily tissues, cells, organs, functions, and the causes of death. The term pathology is a compound of the Greek word for suffering (pathos) and the Anglicized form (-ology) of the Greek word logos meaning the knowledge, reason, or study of something. All of the ways that a disease affects the structure and function of the body are part of the subject matter of the science of pathology. It focuses on the nature of the functions of pathogens, and on the way that abnormal functions develop in the human body (or in animal bodies in the study of veterinary pathology). Another concern of pathology is the study of fetal tissue in fetal cells. The tissue is examined to understand how distortion in the genetic material that composes the DNA of the fetal tissue can be involved in the inheritance of genetic abnormalities. Genetic abnormalities are often involved in birth defects. Paternity testing is used by pathologists to identify the
Pathology is the study of the effects of disease on bodily tissues, cells, organs, functions, and the causes of death.
father or mother of an individual. In the case of infant paternity testing a small blood sample from the infant is used for comparison. Forensic pathology is the work of forensic pathologists who work in the area of forensic medicine. Forensic pathology can study DNA testing to aid the legal system with legal problems. DNA testing can be used by pathologists to establish paternity. It can also be used to identify criminal suspects. Or it can be used to exonerate persons suspected or accused of a crime. With DNA materials, such as hair, skin, saliva, semen, of other bodily fluids left at a crime scene forensic pathologists can establish the DNA identity of the likely perpetrator of the crime. If a person dies without a physician present an autopsy will reveal the cause. This is especially important it if reveal an accidental cause or that the death was caused by misadventure, even if caused by an animal. In such cases a forensic pathologists will act as the case coordinator. The medical history of the deceased, the medical condition of the deceased at death, will be medically and scientifically examined. Clinical pathology is often practiced in hospitals. which usually have a pathology department to identify
the causes of disease. With the advent of modern terrorism, clinical pathology has expanded its traditional study of industrial accidents or chemical emergency responses to include rapid ways to identify chemical weapons. Solving medical problems from chemical poisoning or from other causes means that pathologists often act as medical detectives. Anatomical pathology is a subspecialty of pathology. It is concern with the examination of tissues removed from a patient that will then be subjected to a biopsy. Anatomical pathologists are also called surgical pathologists because they examine surgically removed bodily material. They also engage in autopsies to determine the cause of death. Medically trained medical examiners are anatomical pathologists. Electron microscopes are used by pathologists to see viruses, or the remains of cells. The examination of these very tiny microscopic particles is used to identify or classify diseases, tumors, or disorders. The results of the examination are sent to a physician as a written report. Usually the report will include a diagnosis as to the cause of the disease or death of the patient which will then guide treatment or subsequent legal action if any. Pathologists study changes in the way diseases affect body functions (pathophysiology). For example cells and tissues may be subjected to stress or to injury from a blow. The body at the cellular level responds to these injuries in a variety of ways. Short term responses may include the triggering of genetic codes that are programmed by nature to protect vital proteins or other organs. If the injury is due to a burn, hypoxia, or shock the genetic program may trigger DNA repair. Common sunburn can trigger genetic responses that will activate DNA repair to fix the damaged chromosomes of the skin. If the sun exposure is repeated, the body will produce tanning to protect the skin from burn and from skin damage that could produce cancer. Long term responses include the growth of new blood vessels. Inflammation is a very important part of pathology. It is a complex reaction that shows tissue is fighting infection. Inflammation is acute if it is a non-specific response of the injured cells. Chronic inflammation occurs when the inflammation is long term and persistent. This may occur when the antibiotic fails to eliminate the bacterial agent causing the infection.
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The infection may then spread to other parts of the body. For example a chronic infection in the testicles can spread to the prostate, causing infection there as well. Pathologists identifying the agent will properly report the infectious hazard and its potential for further disease damage, including the potential for the development of cancer. Most cancers are diagnosed by a pathologist. Surgical pathology is also part of anatomical pathology. It involves the microscopic examination of surgical specimens, as well as biopsies performed by non-surgeons. The goal is the specific identification of a disease. Pathologists also engage in cytopathology which is the examination of individual cells. These can be stained or otherwise examined in order to identify the effects of disease or disease agents. Molecular pathology is a growing field in which the organic chemicals in the body are examined for pathological disturbances. Anthropologists use paleopathology to reconstruct the appearance of a long deceased human being from recovered bones. They also seek to study the causes of death using various forms of necropsy. The development of pathology can be traced to Greek physicians like Galen and Hippocrates. Their science was transmitted to the Arabs following the Islamic conquest. During the Medieval Age, physicianphilosophers of the Islamic world engaged in clinical observations that identified the source of diseases such a small pox. Some also made initial attempts at describing the pathology of diseases. Their medical knowledge was transmitted to Europe during the time of the Crusades and by students and physicians coming from Moorish Spain. During the Renaissance medical students and clinical physicians were highly interested in disease. One of the methods for developing pathology was through clinical observation of patients. Another was through autopsies to determine the cause of death. At times pathologists were opposed by people who held ideas that respect for the deceased precluded engaging in autopsies. Eager for knowledge, physicians engaged in the illegal practice of grave robbing at night in order to obtain cadavers. The body was often that of a criminal executed earlier that day. Their crime was justified as a warranted scientific necessity. By the 1800s pathologists had gathered a body of knowledge about gross pathology, which are the cause,
1346 Pathophysiology nature and effects of diseases that can be observed with the unaided eye. Publications were produced depicting different parts of the human anatomy realized through autopsies. Skilled artists aided the work with detailed paintings of organs in both a healthy and diseased state. The invention of the microscope enabled Rudolf Virchow (1821–1902), a German physician, to develop microscope pathology. Microscopes helped pathologists to study diseases and their effects at the microscopic level and to begin experimental pathology. Using techniques to freeze tissue samples, the microscope could reveal different characteristics of the effects of disease on a patient’s organs or other anatomy. The development in the 20th century of the electron microscope, MRI technology, ultrasound technology, microbiology, and other tools enabled rapid advances in pathology. Experimental pathology now involves the study of disease in all forms of life. It has been extended to also include immunohistochemistry which is the study of the immune system and other biochemical reactions. See Also: Genetics; Pathologist; Pathophysiology. Bibliography. Ivan Damjanov, High-Yield Pathology
(Lippincott Williams & Watkins, 2005); Catherine Cavallaro Goodman, et al., Pathology: Implications for the Physical Therapist (Elsevier Science, 2002); Edward C. Klatt and Vinar Kumar, Robbins and Cotran Review of Pathology (Elsevier Science, 2005); Stanley L. Kumar, et al., Basic Pathology (Elsevier Science, 2005); Gerhard Krueger and R. F. Buja, Netter’s Illustrated Pathology (Elsevier Science, 2004); Peter Parham, The Immune System (Taylor & Francis, 2004); Arthur S. Schneider and Philip A. Szanto, BRS Pathology (Lippincott Williams & Wilkins, 2005); Eugene C. Toy, et al., Pathology (McGraw-Hill, 2005). Andrew J. Waskey Dalton State College
Pathophysiology Pathophysiology is the study of the detailed malfunctioning that comes from or causes disease. Physiology
is ���������������������������������������������������� the study of the mechanical, physical, and biochemical functions of living organisms. Pathology means the study of “suffering�� ”� —pathos. In order to study medicine and understand and treat disease, an appreciation for pathophysiology must be extensive. In studying pathophysiology, some topics often looked at are the fundamentals of the cell mechanism and abnormalities, cell division, cell death, tumor growth, and aging. Pathophysiology is essential for all medical staff in varying degrees and can be deficient in the developing world due to lack of funds and access to technology. Pathology is the study of essential nature of disease. It is the study of disease processes and structural and functional changes in organs and tissues that cause or are caused by disease. Pathology is the branch of medicine that analyzes the causes, mechanisms of development, and morphologic manifestations of disease. Most diseases are associated with organ, cell, or organelle dysfunction and this allows the study of pathology to identify the damage that the disease affects. A pathologist must detect and classify the disorder in the tissue or cells of a living patient, as well as determine the disease complex that has led to a patient’s death. This is accomplished by examining tissue specimens obtained from living patients, or a biopsy, or from dead patients, autopsy. Pathology is a mandatory course of study in medicine and offers a detailed look at the many disease processes that attack the human organism. Physiology is the study of how the human body and its systems work. Physiology is broken down into physis or nature and logos or study. The study of physiology includes the complete interaction of organ systems, cells, and organelles that work in synchronization to maintain homeostasis. Physiology is a mandatory course of study in medicine and offers the foundations of how the body works and what can potentially go wrong with its systems. Mechanisms and function of the human body and its systems are inextricably linked with biochemical processes. Biochemistry is the study of the chemical constituents of living matter and of their functions and transformations during life processes. The field of pathobiochemistry deals with the disease states of biochemical processes. Biochemistry is seen as the backbone of most of what the study of medicine comprises. The study of biochemistry is the sum of all chemical pathways and actions in the body, both in the presence and absence
Pauling, Linus
of disease. The study of pathophysiology is closely tied with all of these scientific fields. Every physician must have a sound understanding of these disciplines in order to study and apply pathophysiology to disease. Pathophysiology describes the mechanisms that lead from the primary cause via individual malfunctions to a clinical picture and its possible complications. Knowledge of these mechanisms serves patients to develop a suitable therapy, alleviate symptoms, and avert imminent damage caused by the disease. The reason physicians and healthcare workers study pathophysiology is to be able to better understand how disease negatively affects the human body and then to be able to treat disease. SEE ALSO:� American Society of Clinical Pathologists
(ASCP); Biochemistry; Electrophysiology; Pathology; Physiology.
Bibliography. Stephen J. McPhee and William F. Ga-
nong, Pathophysiology of Disease: An Introduction to Clinical Medicine, 5th ed. (McGraw-Hill, 2006).
John M. Quinn V, M.P.H. University of Illinois at Chicago
Pauling, Linus (1901–94) Born on February 28, 1901, in Portland, Oregon, to Herman Henry William Pauling and Lucy Isabelle Darling, Linus Carl Pauling is the only person to ever win two unshared Nobel Prizes (Nobel Prize in Chemistry in 1954 and the Nobel Peace Prize in 1962). He was also the youngest member elected to the National Academy of Sciences in 1933. Rather than simply making discoveries in a particular field of science, Pauling is credited for revolutionizing chemistry and providing impetus for the formation of molecular biology. After his father died when Pauling was 9, Pauling found solace in books and his homemade laboratory. When 16, Pauling left high school to enroll in the Oregon Agricultural College (Oregon State University). As an undergraduate, he began helping out with class instruction; while teaching a class, he met Ava Helen Miller, marrying her on June 17, 1923. The couple had four children together.
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Graduating in 1922 with a B.S. degree in chemical engineering, he began researching how atoms formed molecules. Attending the California Institute of Technology (CalTech), he earned his Ph.D. in chemistry in 1925, with minors in mathematics and physics. He then studied in Europe for 15 months through Guggenheim Fellowship funding. Mentored overseas in the emerging field of quantum mechanics, Pauling returned to CalTech in 1927 and applied what he learned to his research in chemical structure. Publishing his work in 1939, in The Nature of the Chemical Bond, Pauling began heading the CalTech chemistry division the same year as full professor. During World War II, Pauling created explosives, an oxygen meter for submarines, and other military devices; he rejected the opportunity to head the atomic bomb Manhattan Project because it would separate him from his family. Influenced by his wife’s pacifist beliefs, during the early days of the Cold War, Pauling joined other scientists in requesting limits on nuclear testing. In 1958, he presented a petition to halt atomic bomb testing, signed by thousands of scientists, to the United Nations. In 1960, the United States Senate Subcommittee on Internal Security subpoenaed him to testify about the petition; when he refused, he was threatened with contempt. In 1963, Pauling received the Nobel Peace Prize for 1962. Responses were mixed to this award, and when CalTech did not enthusiastically support Pauling, he resigned, working at numerous other universities. From 1973 until 1994, he researched how to optimize health through ensuring the proper molecules in the body; he considered vitamin C especially important. Over his career, Pauling published more than 500 papers and 11 books. He received a long list of awards, including the first American Chemical Society Award in Pure Chemistry (1931), the Presidential Medal for Merit (1948), and the National Medal of Science (1975). He died of cancer on August 19, 1994. SEE ALSO: Nutrition; Vitamin and Mineral Supplements. Bibliography. From Nobel Lectures, Chemistry 1942–1962
(Elsevier, 1964); “Linus Pauling: The Nobel Prize in Chemistry 1954,” http://nobelprize.org/nobel_prizes/chemistry/ laureates/1954/pauling-bio.html (cited April 2007); “The Linus Pauling Papers,” Profiles in Science, National Library
1348 Pediatrics of Medicine, http://profiles.nlm.nih.gov/MM/Views/Exhibit/narrative/biographical.html (cited April 2007). Kelly Boyer Sagert Independent Scholar
Pediatrics Pediatrics is the medical specialty concerned with the health of infants, children, and adolescents; their growth and development; and their opportunity to achieve full potential as adults. This includes the age group from newborn to age 16–21, depending on the country. The word pediatrics is derived from two Greek words, paidi which means “child” and iatros which means “doctor.” Pediatricians are physicians who assume a responsibility for children’s physical, mental, and emotional progress from conception to maturity. Hence, pediatricians must be concerned with social and environmental influences, which have a major impact on the health and well-being of children and their families, as well as with particular organ systems and biologic processes. The young are often among the most vulnerable or disadvantaged in society, and thus their needs require special attention. In the United States, pediatricians are considered to be primary care doctors, along with family practice, internal medicine, and obstetrics. Much of the rest of the world considers them specialists, and parents are only referred to pediatricians for special care not handled by the generalists. Most pediatricians are members of a national body, such as the American Academy of Pediatrics, the Canadian Paediatric Society, and the British Association of Paediatric Surgeons. Pediatrics emerged as a medical specialty over a century ago in response to increasing awareness that the health problems of children differ from those of adults and that a child’s response to illness and stress varies with age. The obvious body size differences are paralleled by maturational changes. The smaller body of an infant or neonate is substantially different physiologically from that of an adult. Congenital defects, genetic variance, immunology, oncology, and a host of other issues are unique to the realm of pediatrics. Increasingly effective healthcare also means that diseases such as sickle cell anemia and cystic fibrosis are
more often treated by pediatricians, although many or most patients grow into adulthood. Issues revolving around infectious diseases and immunizations are also dealt with primarily by pediatricians. Another major difference between pediatrics and adult medicine is that children are minors and, in most jurisdictions, cannot make decisions for themselves. The issue of guardianship, legal responsibility, and informed consent must always be considered in every pediatric procedure. In a sense, pediatricians often have to treat the parents and, sometimes, the family, rather than just the child. Adolescents are in their own legal class, having rights to their own healthcare decisions in only certain circumstances, although this is in legal flux and varies by region. Moreover, today it is widely recognized that the health problems of children and youth vary widely among the nations of the world depending on a number of factors, which are often interrelated. These factors include the prevalence and ecology of infectious agents and their hosts; climate and geography; agricultural resources and practices; educational, economic, social, and cultural considerations; stage of industrialization and urbanization; and, in many instances, the gene frequencies for some disorders. Assessment of the state of health of any community must begin with a description of the incidence of illness and must continue with studies that show the changes that occur with time and in response to programs of prevention, case finding, therapy, and adequate surveillance. According to current United Nations Children’s Fund (UNICEF) data, there are 71 million children younger than 18 years in the United States and 2.1 billion children younger than 18 years in the rest of the world. Ninety percent of children in the early 21st century are born into the developing or Third World. The mortality rate of children younger than 5 years is eight per 1,000 in the United States and 86 per 1,000 for the overall child population of the world. One thousand infants die each hour; 970 of these deaths occur in developing countries. Causes of death were attributed to malnutrition (54 percent), perinatal conditions (20 percent), pneumonia (19 percent), diarrhea (15 percent), measles (8 percent), malaria (7 percent), HIV/ AIDS (3 percent), and other (28 percent). One-third of births in the developing world are not registered. Population projections to 2025 show
continuing rapid growth in Africa, Western Asia, south central Asia, southeast Asia, west Asia, South America, and Latin America, with modest or slowing growth rates in east Asia, North America, and Europe. Hundreds of thousands of children born in developing countries move into Europe and into North America as refugees, immigrants, or international adoptees. Between 1980 and 2000, there were dramatic increases in the percentage of children immunized in developing countries and, as a result, diseases such as poliomyelitis and measles are much less common. However, immunizations for diseases such as hepatitis, haemophilus influenza b, and varicella are rarely available in the developing world. The number of children infected with HIV has increased dramatically, as has the number of children suffering from malnutrition associated with disasters. Malaria and tuberculosis also affect greater numbers of children than they did a decade ago. Malaria is the leading cause of hospitalization, mortality, and morbidity in children younger than 5 years who live in sub-Saharan Africa. Malnutrition, including both calorie and micronutrient deprivation, causes acute and chronic morbidity, contributes to reduced immunity, and increases the likelihood of mortality and morbidity in association with infectious diseases. Physicians caring for children have been increasingly called on to advise in the management of disturbed behavior of children and youth or problematic relationships between child and parent, child and school, or child and community. They are increasingly concerned with problems of mental, social, and societal health. There is also an increasing concern about disparities in how the benefits of what we know about child health reach various groups of children. Just as in many developing countries, so in the United States does the health of children lag far behind what it could be if the means and will to apply current knowledge were focused on the health of children. The medical problems of children are often intimately related to problems of mental and social health. The children most at risk are disproportionately represented among ethnic minority groups. Pediatricians have a responsibility to aggressively address problems such as these.
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Impaired Learning Approximately one-third of children younger than 15 years in developing countries either have or are at risk for impaired learning. Major hazards to early brain development include malnutrition, infectious diseases (e.g., meningitis), prematurity and newborn asphyxia, in utero exposure to alcohol and drugs, lead poisoning, genetic disorders, head injuries, and institutionalization. Malnutrition experienced during the critical periods of brain development from the second trimester of pregnancy until 2 years of age is most likely to be associated with subsequent cognitive impairment. Iron deficiency, very common among infants in the developing world, is associated with continuing learning problems a decade later. Iodine deficiency is also common, especially in large areas of China, central Africa, and South America, and is associated with mental impairment in children. Institutionalization The number of children institutionalized in developing countries is unknown, but the number of institutions for orphan children has increased in countries of the former Soviet Union, eastern Europe, sub-Saharan Africa, India, and China in the past decade. Reasons include death of parents from AIDS, poverty in families who might ordinarily adopt child relatives, political upheavals, and community chaos. A small percentage of institutionalized children are adopted by North American or European families. Eighteen thousand children from abroad are adopted into American families each year. About half of children adopted from orphanages abroad are malnourished. Rickets is common, as are intestinal parasites. Many children have been infected with tuberculosis, hepatitis B, hepatitis C, or syphilis. Of great concern are the frequent developmental delays and attachment problems, which increase after the first year of life of these orphan children. Approach to Child Health in the Developing World Traditionally, efforts to improve child health in the developing world have focused on primary healthcare. This approach concentrates on improving public health and basic healthcare at the community level, usually by training village health workers to recognize and manage childhood illnesses such as diarrhea and pneumonia. The primary healthcare approach is essential in developing countries where access to basic
1350 Penile Cancer medical facilities and trained healthcare professionals is often lacking and where the majority of childhood diseases are preventable. However, the primary healthcare approach includes teaching village health workers to recognize and refer sick patients to acute healthcare facilities. Currently, there are inadequate resources devoted to training health professionals and establishing such referral centers in most developing countries; they often do not exist and, therefore, sicker children suffer or die. However, as the public health infrastructure improves in a developing country, it becomes increasingly important to train local child health specialists. These child health specialists provide referral care to individual children and serve as the backbone for long-term improvements in child health by providing local expertise and knowledge for the formulation of child health policy in their own countries. In most settings, it is difficult to separate the health of the child from that of the family and the broader social context in which the child lives. This is particularly true in the developing world. Maternal health practices strongly impact child health, particularly in the perinatal period. Prenatal care, neonatal resuscitation, maternal nutrition, breast-feeding and weaning practices, and maternal depression all may have profound effects on a child’s well-being. Economic conditions and family resources drive healthcare decision making. Environmental conditions limit the effective treatment of preventable illnesses such as diarrhea and malaria. Much of the childhood disease burden in developing countries may rightfully be seen as the medical manifestations of social illnesses, such as lack of education, poverty, and other forms of injustice. Pediatric Research in the Developing World Pediatric research in developing countries has lagged behind that in Western countries. As a result, there is a lack of knowledge in many areas, including, for example, the long-term effects of medications used to treat many parasitic infections, the interactions between traditional herbal therapies and antibiotics, the extent of genetic diseases, the prevalence of iron deficiency, and the neurodevelopmental effects of cerebral malaria. It is appropriate for child health specialists and institutions from wealthier nations to
assist colleagues in developing countries to develop research skills, design appropriate projects, find financial support, and implement the research project. Future of Pediatrics It is important that child health professionals do their best for individual child patients and also participate in the broader public health and community planning on behalf of children. The 1990 United Nations World Summit for Children recommended a 10-year program to achieve basic health and social goals for children. With the exception of the immunization goals, they were not met. Probably the highest priority for the world should be the prevention of childhood learning problems. Health and human service professionals around the world must foster a global awareness about the impact of early events on the developing brain of a child, on his or her life, on the community, and on the world. SEE ALSO: Adolescent Development; Adolescent Health; American Academy of Pediatrics (AAP); Association of Women’s Health, Obstetric, and Neonatal Nurses (AWHONN); Breast Feeding; Cerebral Palsy; Child Abuse; Child Behavior Disorders; Child Dental Health; Child Development; Child Mental Health; Child Safety; Childhood Cancers; Childhood Immunization; Infant and Newborn Care; Neonatology; Neonatologist; Prenatal Care. Bibliography. March of Dimes, The Growing Problem
of Prematurity (March of Dimes, 2006); J.A. Martin et al., “Births: Final Data for 2004,” National Vital Statistics Reports (v.55/1); T.J. Mathew and M.F. MacDorman, “Infant Mortality Statistics from the 2003 Period Linked Birth/ Infant Death Data Set,” National Vital Statistics Reports (v.54/16, 2006); Mayo Clinic, Premature Birth (Mayo Clinic, 2006). Barkha N. Gurbani University of California, Los Angeles
Penile Cancer Penile cancer is a cancer of the penis, which is an external part of the male reproductive organ. It is a rare form of cancer that causes around three hun-
dred deaths per year in the United States. Around twelve hundred new cases are diagnosed each year. It is much more common in other parts of the world where unprotected sexual activity and poor hygiene is more prevalent. Cancer of the penis is a slow growing type of cancer that is curable if diagnosed early. It can occur anywhere along the shaft of the penis. Most penile cancer events occur on the foreskin or on the glans penis, which is the head or tip of the penis. In the United States penile cancer is rare in both uncircumcised and circumcised males. It almost never occurs in men circumcised as infants. This fact is often used to bolster the argument for male circumcision as a method for hygiene. However, it occurs in higher rates in males circumcised at puberty and at the same rates for males circumcised as adults as it does for those not circumcised. Penile cancer is associated with a failure to wash after sexual activity. In the uncircumcised male the foreskin (smegma) if not washed carefully can become a source or irritation. Poor hygiene leaves dead skin cells to produce irritations that can lead to cancer. In uncircumcised males the foreskin can be a hiding place for yeasts, viruses or bacteria that can expose sexual partners to disease. Sexually transmitted disease is associated with penile cancer. Venereal warts (condyloma acuminate) often play a role in the development of penile cancer. Studies have shown a relationship between human papilloma virus (HPV) types 16 and 18 that cause penile warts and the development of penile cancer. Precancerous penile lesions can become cancerous. Erythroplasia of Queyrat (Bowen’s disease) is a precancerous lesion in which cytological features seem to be malignant, but are not. The lesion is limited to the epithelium. Usually lesions on the shaft of the penis are referred to as Bowen’s disease while those on the glans penis are called erythoplasia of Queyrat. Both types may turn into squamous cell carcinoma. The lesions occurs almost exclusively in uncircumcised males. Bowenoid papulosis lesions are rare and are probably caused by the sexually transmitted human papillomavirus type 16. The lesions can be found in both males and females. The lesions will appear reddish brown or violent in color. They will be small, solid and sometimes have a velvety character. Bowenoid papulosis does not appear to turn cancerous.
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Penile cancer has several forms. The most common form is cause by squamous cells that turn into carcinomas. The squamous cells are flat cells that line the penis. Other cancers are melanomas. These are visible as blue-brown growths on the penis, usually the glans penis. Sometimes sarcomas form within the deep tissues of the penis. If not treated penile cancer will spread to deeper tissues and eventually to lymph nodes in the groin or inguinal area. As long as the cancer has not spread to the pelvic lymph nodes it is usually curable. Symptoms of penile cancer usually present themselves as a raised lump or lesion on the penis. Often it begins as an area that is an unexplained change in penile skin color. Diagnosis is made with a biopsy. Diagnosis of penile cancer will be followed by tests to determine into which of four stages it has developed. In the first stage cancer cells have formed only on the glans or the foreskin. In the second stage cancer cells will have penetrated into deeper tissues and will have spread to the shaft. In the third stage many parts of the penis may be affected with cells having spread into the lymph nodes of the groin area. In fourth stage penile cancer, the cancer cells will be found throughout the penis, lymph nodes of the goin, and in other parts of the body. There are a variety of therapies used to treat penile cancer. These include surgery, chemotherapy and radiation. The treatment(s) selected will depend upon the stage of the cancer. Small localized tumors can be surgically removed. Or they might be treated chemically, with radiation or with a laser. The penis does not suffer significant damage in either appearance or in its function from these operations. The larger the tumor, the more surgery will be necessary. Radiation is less successful and is a second choice because the results have usually not be as successful as they are with surgery. Chemotherapy has not been found to be useful in advanced stages. In late stages, surgical removal of lymph nodes as well as radiation of tumors produce the best results but the prognosis is more guarded. See Also: Cancer (General); Cancer Alternative Therapy;
Cancer Chemotherapy; Cancer Radiation Therapy.
Bibliography. Karen Bellenir, ed., Prostate and Urological Disorders SourceBook: Basic Consumer Heath
1352 Peptic Ulcer Information about Urogenital and Sexual Disorders in Men, Including Prostate and Other Andrological Cancers, Prostatitis, Benign Prostatic Hyperplasia, Testicular and Penile (Omnigraphics Incorporated, 2006); Marc S. Ernstoff, et al., Testicular and Penile Cancer (Blackwell Publishers, 1998); Penile Cancer—a Medical Dictionary, Bibliography, and Annotated Research Guide to Internet Resources (Icon Health Publications, 2004); The Official Patient’s Sourcebook on Penile Cancer: A Revised and Updated Directory for the Internet Age (Icon Health Publications, 2004). Andrew J. Waskey Dalton State College
Peptic Ulcer Peptic ulcer, also known as peptic ulcer disease (PUD), is caused by stomach acid and gastric juices eroding the gastrointestinal mucosa. The ulcer usually originates in the duodenum (first part of the small intestine), esophagus (muscular tube from throat to stomach), or stomach regions. Duodenal ulcers and gastric ulcers are two main types of peptic ulcers. Among them, duodenal ulcers are most common. They principally arise on duodenal bulb (first part of duodenum). Gastric ulcers that occur anywhere in stomach are usually benign and are more contrived by female patients than seen in male patients. Recent research studies reveal the spiral-shaped bacterium Helicobacter pylori as the most important cause of peptic ulcers. However, not everyone with this bacterium suffer from peptic ulcers. Other factors such as gastric tumor, overdose of aspirin, tobacco smoking, Zollinger-Ellison syndrome, and stress also contribute in the setting of for PUD. Typically, a peptic ulcer begins as a sore or erosion in the wall of the gastrointestinal tract. This, however, leads to an ultimate breakdown of tissue which causes severe burning pain in the abdomen. One in 10 people in the United States suffer from an ulcer and approximately 500,000 new ulcer cases occur every year. Among them, patients between ages 30 and 55 are most susceptible to duodenal ulcers, while patients between ages 55 and 70 are at risk of developing gastric ulcers. Double the number of men is affected by duodenal ulcer than women. Most pep-
tic ulcers are idiopathic in nature and about 10 percent of patients suffer from upper gastrointestinal tract bleeding. More often, bleeding will stop spontaneously; however, in some patients, it could be severe. Although ulcers can occur at any age, they are rare in young patients and mortality rate is higher in elderly patients. A key symptom indicating peptic ulcer disease in these patients is a bright red, coffee groundlike blood in the vomitus. This condition is known as hematemesis. Blood passed into the patient’s feces gives rise to a condition known as melaena (black stool with foul smell). One might have an ulcer and may still not experience any kind of symptoms. However, abdominal pain associated with indigestion in upper middle part or lower chest region is often observed. Usual symptoms for PUD includes abdominal pain with bloating and abdominal fullness, nausea, vomiting, loss of weight and appetite, and feces with foul smell. Occasionally, an ulcer might create a duodenal or gastric puncture that leads to bleeding. Surgery will be an option under this rare situation. Although clinically capricious, in general, symptoms with epigastric (upper middle part of abdomen) pain during mealtimes play a significant role in distinguishing duodenal ulcers from gastric ulcers. A warning sign for duodenal ulcer is visible before meal when the patient experiences a hunger attack due to acid production. This pain is alleviated by ingestion of food. Contrary to the duodenal ulcers, an ulcer indicating a gastric region is worsened after a meal, due to intake of food that leads to gastric acid secretion and reflux of alkaline duodenal contents into the stomach. While H. pylori infection is a major cause of PUD, stress also has been associated and is now gaining recognition by researchers as a possible cause. This possibility takes a strong position as most people with H. pylori infection do not necessarily suffer from an ulcer. At present, researchers believe that ulcers result from a combined effect of both psychological stress and bacterial infection. While it is unknown at present to what extend stress actually creates risk for contriving an ulcer, researchers propose that unraveling the mystery will be a notable breakthrough for both clinical psychology and pathology of PUD. After a physician has diagnosed PUD, a patient may have to undergo a barium meal X-ray or a gastrointestinal endoscopy (where a fiber-optic tube
Perinatology
is passed down the patient’s esophagus). Most physicians prefer to use endoscopy as it helps in taking biopsies which can confirm or reject the presence of bacterial infection. It also helps in ruling out the possibilities for other disease conditions. A simple blood test that measures the chemicals present in a patient’s breath may be ordered by a doctor to completely nullify the possibility for H. pylori infection. Physicians frequently prescribe medications that will reduce the acid production (antacids like histamine blockers and proton pump inhibitors) in stomach to cure an ulcer. If a patient has a bacterial infection, then a regimen called triple or double therapy might be used by a physician. In the double therapy, an antibiotic and a proton pump inhibitor are used to treat a patient. On the other hand, triple therapy uses two antibiotics and a proton pump inhibitor as a form of treatment. This type of treatment plan is aimed to fight bacterial infection while curing the ulcer simultaneously and lessening the frequency for either to reoccur. Additional treatment and prevention plan should include giving up smoking and drinking, eating regularly in small meals, and avoiding food that induce pain. If all treatment plans fail, then surgery might be an option for patients suffering from PUD.
time birth takes place, after which the mother and baby are treated by a neonatologist. Expectant mothers are urged to contact perinatologists as soon as they feel that there may be problems with the birth, and perinatologists are then involved in checking scans of the fetus for abnormalities in the neck and also in the development of the spine, chest, abdominal wall, diaphragm, and body organs such as the heart, stomach, kidneys, and bladder, as well as the umbilical cord, placenta, and the volume of amniotic fluid. Major hospitals around the world often have a perinatology department or have access to perinatologists whom they call upon for help with difficult pregnancies and births. Some are known as perinatal centers, with others having different names such as the Fetal Treatment Center at the University of California, San Francisco. SEE ALSO: Perinatology. Bibliography. Peter M. Dunn, “Dr John Ballantyne
1861–1923: Perinatologist Extraordinary of Edinburgh,” Archives of Disease in Childhood (v.68/1, 1993); Edith L. Potter, “Reminiscences of a Perinatologist,” Journal of the American Medical Association (v.262, 1989). Justin Corfield Geelong Grammar School
SEE ALSO: Gastrointestinal Bleeding; Ulcers. Bibliography. eMedicineHealth, “Peptic Ulcers,” www.
emedicinehealth.com (cited January 22, 2007); Martin S. Lipsky, ed., AMA: Concise Medical Encyclopedia (Random House Reference, 2007); Maxine A. Papadakis and Stephen J. McPhee, 2007 Current Consult Medicine (McGraw Hill, 2007). Jinal Mehta University of Missouri
Perinatologist A perinatologist is an obstetrician who has specialist training to treat a pregnant mother and an unborn fetus where, for whatever reason, there is a greater concern about more complications than with a normal birth. Usually, this is concerned with the period from the 20th until the 28th week of gestation, at which
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Perinatology Perinatology is subsection of obstetrics, with the comparable area of pediatrics called neonatology. It is concerned with the care that has to be provided for the pregnant mother and the fetus which may be at a greater-than-normal threat of developing complications. This covers what is known as the perinatal period which includes the last eight weeks before birth, being from the 20th to the 28th week of gestation, and continued until between one and four weeks after birth. Generally, perinatology is the care of the fetus before birth, with neonatology taking over after birth. The word perinatology comes from the Greek word peri, which means “about” or “around,” combined with the Latin natus which means “born” and the Greek logos which refers to a study of a particular specialty. This
1354 Peripheral Nerve Disorders developed in time to a profession on its own, although there remains the overlap with obstetricians. There are also a number of journals for the profession including the American Journal of Perinatology published by Thieme-Stratton since 1983; the Journal of Perinatal Medicine, the official journal of the World Association of Perinatal Medicine, published since 1973; the Journal of Perinatology, the official journal of the National Perinatal Association, and published since 1981; and Seminars in Perinatology, published by Grune & Stratton since 1979. There are regular workshops in many countries for people involved in perinatology, and also congresses held around the world. SEE ALSO: Obstetrician/Gynecologist; Obstetrics; Perina-
tologist.
Bibliography. Helen Farrer, Maternity Care (Churchill
Livingstone, 1990); S. G. Matthews and M. J. Meaney, “Behavioral Perinatology,” in A. Riecher-Rössler and M. Steiner, eds., Perinatal Stress, Mood and Anxiety Disorders (Karger, 2005); Perinatology.com, http://www.perinatology.com; Carson Strong, Ethics in Reproductive and Perinatal Medicine: A New Framework (Yale University Press, 1997); Frederick P. Zuspan, ed., Current Developments in Perinatology: The Fetus, Placenta and Newborn, a Collection of Articles from the Current Developments Section of the American Journal of Obstetrics and Gynecology (Mosby, 1977). Justin Corfield Geelong Grammar School
Peripheral Nerve Disorders Peripheral neuropathy is a general term referring to disorders of peripheral nerves. The peripheral nervous system is made up of the nerves that branch out of the spinal cord to all parts of the body. Neuro means nerves. Pathy means abnormal. Peripheral neuropathy is very common. Because there are numerous types and causes of neuropathy and scientists do not always agree on the same definition of neuropathy, the exact incidence cannot be precisely determined. Peripheral neuropathy can be associated with poor nutrition, a number of diseases, and pressure or
trauma. Many people suffer from the disorder without ever identifying the cause. Peripheral neuropathy affects at least 20 million people in the United States. Nearly 60 percent of all people with diabetes suffer from peripheral neuropathy. Peripheral neuropathy may involve damage to a single nerve or nerve group (mononeuropathy) or may affect multiple nerves (polyneuropathy). Mononeuropathies may be due to entrapment, compression, stretch injury, ischemia, infection, or inflammation of a nerve. Polyneuropathies are relatively symmetric, often affecting sensory, motor, and vasomotor fibers simultaneously. More than 100 types of peripheral neuropathy have been identified, each with its own characteristic set of symptoms, pattern of development, and prognosis. Impaired function and symptoms depend on the type of nerves—motor, sensory, or autonomic—that are damaged. Motor nerves control movements of all muscles under conscious control, such as those used for walking, grasping things, or talking. Sensory nerves transmit information about sensory experiences, such as the feeling of a light touch or the pain resulting from a cut. Autonomic nerves regulate biological activities that people do not control consciously, such as breathing, digesting food, and heart and gland functions. Although some neuropathies may affect all three types of nerves, others primarily affect one or two types. Peripheral neuropathy may be either inherited or acquired. Causes of acquired peripheral neuropathy include physical injury (trauma) to a nerve, tumors, toxins, autoimmune responses, nutritional deficiencies, alcoholism, and vascular and metabolic disorders. Acquired peripheral neuropathies are grouped into three broad categories: those caused by systemic disease, those caused by trauma from external agents, and those caused by infections or autoimmune disorders affecting nerve tissue. In some cases, the cause is an earlier viral infection, pressure on the nerve from a tumor or swollen blood vessel, or infrequently, multiple sclerosis. In many cases, however, a specific cause cannot be identified. Doctors usually refer to neuropathies with no known cause as idiopathic neuropathies. Physical injury (trauma) is the most common cause of injury to a nerve. Injury or sudden trauma, such as from automobile accidents, falls, and sports-related activities, can cause nerves to be partially or completely severed, crushed, compressed, or stretched,
sometimes so forcefully that they are partially or completely detached from the spinal cord. Systemic diseases, disorders that affect the entire body, often cause peripheral neuropathy. These disorders may include metabolic and endocrine disorders. Nerve tissues are highly vulnerable to damage from diseases that impair the body’s ability to transform nutrients into energy, process waste products, or manufacture the substances that make up living tissue. Diabetes mellitus, characterized by chronically high blood glucose levels, is a leading cause of peripheral neuropathy in the United States. About 60 to 70 percent of people with diabetes have mild to severe forms of nervous system damage. Kidney disorders can lead to abnormally high amounts of toxic substances in the blood that can severely damage nerve tissue. A majority of patients who require dialysis because of kidney failure develop polyneuropathy. Some liver diseases also lead to neuropathies as a result of chemical imbalances. Hormonal imbalances can disturb normal metabolic processes and cause neuropathies. For example, an underproduction of thyroid hormones slows metabolism, leading to fluid retention and swollen tissues that can exert pressure on peripheral nerves. Overproduction of growth hormone can lead to acromegaly, a condition characterized by the abnormal enlargement of many parts of the skeleton, including the joints. Nerves running through these affected joints often become entrapped. Vitamin deficiencies and alcoholism can cause widespread damage to nerve tissue. Vitamins E, B1, B6, B12, and niacin are essential to healthy nerve function. Thiamine deficiency, in particular, is common among people with alcoholism because they often also have poor dietary habits. Thiamine deficiency can cause a painful neuropathy of the extremities. Vascular damage and blood diseases can decrease oxygen supply to the peripheral nerves and quickly lead to serious damage to or death of nerve tissues, much as a sudden lack of oxygen to the brain can cause a stroke. Diabetes frequently leads to blood vessel constriction. Various forms of vasculitis (blood vessel inflammation) frequently cause vessel walls to harden, thicken, and develop scar tissue, decreasing their diameter and impeding blood flow. Connective tissue disorders and chronic inflammation can cause direct and indirect nerve damage.
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When the multiple layers of protective tissue surrounding nerves become inflamed, the inflammation can spread directly into nerve fibers. Chronic inflammation also leads to the progressive destruction of connective tissue, making nerve fibers more vulnerable to compression injuries and infections. Cancers and benign tumors can infiltrate or exert damaging pressure on nerve fibers. Tumors also can arise directly from nerve tissue cells. Widespread polyneuropathy is often associated with the neurofibromatoses, genetic diseases in which multiple benign tumors grow on nerve tissue. Neuromas, benign masses of overgrown nerve tissue that can develop after any penetrating injury that severs nerve fibers, generate very intense pain signals and sometimes engulf neighboring nerves, leading to further damage and even greater pain. Repetitive stress frequently leads to entrapment neuropathies, a special category of compression injury. Cumulative damage can result from repetitive, forceful, awkward activities that require flexing of any group of joints for prolonged periods. The resulting irritation may cause ligaments, tendons, and muscles to become inflamed and swollen, constricting the narrow passageways through which some nerves pass. Toxins can also cause peripheral nerve damage. People who are exposed to heavy metals (arsenic, lead, mercury, thallium), industrial drugs, or environmental toxins frequently develop neuropathy. Certain anticancer drugs, anticonvulsants, antiviral agents, and antibiotics have side effects that can include peripheral nerve damage, thus limiting their long-term use. Infections and autoimmune disorders can cause peripheral neuropathy. Viruses and bacteria that can attack nerve tissues include herpes varicella-zoster (shingles), Epstein-Barr virus, cytomegalovirus, and herpes simplex—members of the large family of human herpes viruses. These viruses severely damage sensory nerves, causing attacks of sharp, lightning-like pain. Postherpetic neuralgia often occurs after an attack of shingles and can be particularly painful. The human immunodeficiency virus (HIV), which causes AIDS, also causes extensive damage to the central and peripheral nervous systems. A rapidly progressive, painful polyneuropathy affecting the feet and hands is often the first clinically apparent sign of HIV infection. Lyme disease, diphtheria, and leprosy are bacterial diseases characterized by extensive peripheral nerve
1356 Peru damage. Diphtheria and leprosy are now rare in the United States, but Lyme disease is on the rise. It can cause a wide range of neuropathic disorders, including a rapidly developing, painful polyneuropathy, often within a few weeks after initial infection by a tick bite. Acute inflammatory demyelinating neuropathy, better known as Guillain-Barré syndrome, can damage motor, sensory, and autonomic nerve fibers. Most people recover from this syndrome, although severe cases can be life threatening. Chronic inflammatory demyelinating polyneuropathy (CIDP), generally less dangerous, usually damages sensory and motor nerves, leaving autonomic nerves intact. Multifocal motor neuropathy is a form of inflammatory neuropathy that affects motor nerves exclusively; it may be chronic or acute. Inherited forms of peripheral neuropathy are caused by inborn mistakes in the genetic code or by new genetic mutations. Some genetic errors lead to mild neuropathies with symptoms that begin in early adulthood and result in little, if any, significant impairment. More severe hereditary neuropathies often appear in infancy or childhood. The most common inherited neuropathies are a group of disorders collectively referred to as Charcot-Marie-Tooth disease. These neuropathies result from flaws in genes responsible for manufacturing neurons or the myelin sheath. Hallmarks of typical Charcot-Marie-Tooth disease include extreme weakening and wasting of muscles in the lower legs and feet, gait abnormalities, loss of tendon reflexes, and numbness in the lower limbs. The National Institute of Neurological Disorders and Stroke (NINDS), a component of the federal government’s National Institutes of Health (NIH) within the U.S. Department of Health and Human Services, has primary responsibility for research on peripheral neuropathy. Current research projects funded by the NINDS involve investigations of genetic factors associated with hereditary neuropathies, studies of biological mechanisms involved in diabetes-associated neuropathies, efforts to gain greater understanding of how the immune system contributes to peripheral nerve damage, and efforts to develop new therapies for neuropathic symptoms. Because specific genetic defects have been identified for only a fraction of the known hereditary neuropathies, the Institute sponsors studies to identify other genetic defects that may cause these conditions.
Presymptomatic diagnosis may lead to therapies for preventing nerve damage before it occurs, and gene replacement therapies could be developed to prevent or reduce cumulative nerve damage. SEE ALSO: Autoimmune Diseases (General); Brain Dis-
eases; Degenerative Nerve Diseases; Dementia; Headache and Migraine; Movement Disorders; National Institute of Neurological Disorders and Stroke (NINDS); Spinal Cord Diseases; Spinal Cord Injuries. Bibliography. S. Delalande, et al., “���������������� Neurologic Mani-
festations in Primary Sjogren Syndrome: A Study of 82 Patients,” Medicine (v.83/5, 2004); S. E. Guillett, “Using a Rehabilitation Approach to Wound Care in the Home Setting: A Case Study,” Home Healthcare Nurse (v.24/7, 2006); K. Mori, M. Iijima, and M. Sugiura, “Sjogren’s Syndrome Associated Painful Sensory Neuropathy without Sensory Ataxia,” Journal of Neurology, Neurosurgery, and Psychiatry (v.74/9, 2003); “Sciatic Nerve Injury Following Intramuscular Injection: A Case Report and Review of the Literature,” Journal of Neuroscience Nursing (v.38/4, 2006); G. R. Spollett, “Diabetic Neuropathies: Diagnosis and Treatment,” Nursing Clinics of North America (v.41/4, 2006). Barkha Gurban University of California, Los Angeles
Peru Peru is a republic on the western coast of South America, bordered by Ecuador and Colombia to the north, Brazil to the East, Chile to the south, and the Pacific to the west. Once the center of Inca civilization, the region was conquered by the Spanish in 1532 and became the administrative center of their colonial holdings. Peru won independence in 1821. It is the world’s 20th largest country, with an area about twice the size of Texas. Peru is developing country which has been slowly modernizing over the past decade, but economic and political change is slow for the half of the population currently living in poverty. Peru is home to an estimates 28,675,000 people, growing at a rate of 1.29 percent annually. Birth rates and death rates have both dropped in recent years, now standing at 20.09 births per 1,000 population
Pesticides
and 6.21 deaths per 1,000 population. The total fertility rate has also dropped, with 2.46 children born per woman. The median age is 25.5 years. Life expectancy is 68.33 years for males and 72.04 years for females. Peru has a diverse economy, but gross national income is relatively low at $2,610 per capita, and 13 percent of the population lives on $1 a day. Communicable diseases have declined sharply from the 1980s. While 2.5 million live in malaria zones, 3.4 million live in dengue fever zones, and 600,000 are at risk for Chagas’ disease, annual rates of infection have been reduced. Cholera rates have also declined. Yellow fever and hepatitis B are still common in some areas. There are less than two dozen cases of plague a year, a decrease attributed to the replacement of old silos with newer, metal structure that keep rodents at bay. HIV/AIDS is has a prevalence rate of 0.6 percent, with an estimated 93,000 cases and about 5,600 AIDSrelated deaths. The virus is concentrated primarily among the poor in the coastal regions of the country. Peru has established a Country Coordinating Mechanism comprised of a loose affiliation of government agencies, international and national non-governmental organizations to develop a nationwide AIDS policy and educational programs, although most agree that the country needs a national coordinating body. Peru’s geography and climate make it suseptible to natural disasters, and the government counted 1,478 such events in the period between 1993-97 alone. These disasters killed 1,600 and impacted close to 1 million others. Accidents and violence have decreased since the 1990s, although the number of traffic accidents have climbed as the country has become more urbanized. Peru has both a public and a private health care system. In 1997, there were 7,304 hospitals and health care centers operating within the county, with 81 percent administered by the national Ministry of Health. The number of beds varies, with 1 bed per 666 people in the city of Lima, and 1 bed per 1,250 for the rest of the country. The government spends around $49 per capita on health care. Medical personnel in 1999 included 30,000 physicians, 2,800 dentists, and 17,000 nurses.
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Pan American Health Organization, “Peru: Country Health Profile”. Health in the Americas,” 1998. http://www.paho. org/english/HIA1998/Peru.pdf (cited August 2007). Heather K. Michon Independent Scholar
Pesticides Pesticides are materials used to eliminate or reduce pests. Pests can be defined as insects, weeds, mammals, and pathogens or microorganisms. Insects and weeds cause damage in agricultural products all over the world, causing losses in food production. Currently, there are between 6 to 7 billion people in the world and 79 percent of those people are undernourished. Food production is the most critical industry in the world. Pest control is necessary in our overpopulated world. Insects also transmit human diseases. Through the spread of disease, public heath can be threatened. Malaria is an example of a deadly virus spread through infected mosquitoes. In this case, a powerful pesticide, dichloro-diphenyl-trichloroethane (DDT), is used to kill the mosquitoes that carry the virus. DDT has been banned in the United States; however, it continues to be used in developing countries, which has led to a controversy over its use. DDT is toxic to human heath; however, the World Health Organization (WHO) recently sanctioned South Africa’s use of DDT to combat their malaria epidemic. Pesticides are categorized according to the type of pests they control: herbicides are used to eliminate weeds so that
SEE ALSO: Healthcare, South America. Bibliography. Central Intelligence Agency, “Peru,” CIA
World Factbook. https://www.cia.gov/library/publications/ the-world-factbook/geos/pe.html (cited August 2007); The
While pest control is necessary, the health effects of pesticides are a concern of everyone on the planet.
1358 Pesticides agricultural products can grow; fungicides are used on plants to prevent diseases in agriculture and wood is treated with fungicides for building; insecticides are used by farmers, public health officials, and individuals to prevent insects from damaging or destroying plants and hurting people; fumigants are used to rid public spaces of disease or insects; rodenticides are used to control rats and other small animals that carry diseases. It is obvious that using pesticides has the immediate, positive effect of killing or reducing pests so that agricultural products can thrive and so that humans can live without the threat of disease. However, pesticides can have a detrimental and unwanted effect on human health. The negative health effects of using some pesticides have been shown through research, which has led to legislation on the use and handling of these chemicals. Due to the toxic effect of chemical pesticide use and the short-term effectiveness of these chemicals on pests, new pest control methods are being introduced that integrate chemicals and more natural methods. Pesticides are ubiquitous and will continue to be used; therefore, it is important to know how to handle food products that have pesticide residual on them to eliminate the potential negative health effects. Pesticide Categories Organophosphate pesticides affect the nervous system, for example, chlorpyritos, diazinon, malathion, trichlorfon, and fenitrothion. Carbamate pesticides affect the nervous system, for example, carbaryl, aldicarb, methomyl, carbofuran, and oxamyl. Organochlorine insectocides were used heavily in the past but have recently been banned in some countries. DDT and chlordane are two of these; DDT is still used in some countries. Other pesticides used today are HCH (BHC), aldrin, and deldrin. Pyrethroid pesticides were developed as a version of a natural pesticide found in chrysanthemums; some of the synthetic pyrethroids are permethrin, allethrin, cypermethrin, and deltamethrin. Effects of Pesticides Chemicals used to kill pests are quite potent, but their effectiveness is only good in the short term because, over time, all insects and weeds develop a
resistance to the chemical used to control them. As a result, the descendents of the offending insects and weeds will be stronger and will no longer be inhibited by the chemicals used to kill the parent plant or insect. New, stronger chemical pesticides will then be needed to kill these pests. This cycle of attempting to outsmart the natural survival of plants and insects is not effective. Since the 1990s, it was found that over 600 species of plants and insect pests were resistant to at least one category of pesticide. The plant and animal world is genetically preselected to survive; therefore, synthetic, toxic chemicals will always lag behind the natural enemy (plants or insects) they seek to control. The worst aspect of this proliferation of pesticides is the unintended, negative health effects on humans. Pesticides used in agriculture are carried away in the runoff water, entering the public water supply through underground water. Plants sprayed with chemicals blow onto the yards of nearby families. Food we buy at the produce stand and grocery store has pesticides on them. Nowadays, most people have trace amounts of pesticides in their fat tissue. The health effects are a concern of everyone on the planet. Health Effects of Pesticides There are many ways people come into contact with pesticides: through the air we breathe and the food we eat, as well as the water we drink. Pesticides are insidious. Unfortunately, pesticides are harmful to humans. In fact, many pesticides that are currently being used were developed for chemical warfare during World War II. However, the use of pesticides continue to grow dramatically. Since the 1940s, the use of pesticides has increased 10-fold. Pesticides have been found in the groundwater in 26 states. In California, farmers who are exposed to pesticides have a high risk of cancer. In 1987, the National Cancer Institute showed that children living in homes where garden and household pesticides were used were seven times more likely to develop childhood leukemia. Specific Ways Pesticides Impact Health There are three main pathways through which pesticides can negatively effect human health. (1) Some pesticides are known carcinogens, that is, exposure to them can cause cancer. Some known carcinogens
are chromated copper arsenate (CCA), methylbromide, DDT, acetochlor, thiacloprid. (2) Other pesticides—referred to as endocrine disruptors—contain chemicals that mimic naturally occurring hormones in the body. Exposure to these chemicals causes a disruption in the endocrine (hormonal) system. This is especially problematic for children because they are still developing and their development may be altered in some way due to exposure to the pesticide. Some of these pesticides are atrazine, DDT, and metabolite DDE, endimethalin, aldicarb, fenitrothion. (3) The third pathway by which we can be harmed by pesticides is through the neurological system (nerves). Pesticides of this category affect the nervous system and, ultimately, the brain. Some of these pesticides are organochloride insecticides, organophosphorous insecticides, prethroids, and nicotinoids. Safe Levels The use of pesticides are limited in that the concentration that is applied in the environment is limited by law as well as by the number of applications and the methods of application. Government agencies have arrived at a standard for use on farmland and on edible plants and produce. (See “Legislation on Pesticides.”) However, this safe level has been arrived at through a limited number of research studies. The total health effects of pesticides is yet unknown because not all of the research has been used to arrive at the acceptable standards. A number of research studies have been done on animals that has shown the toxic and fatal effects of pesticides on small animals (mammals); however, there is controversy over how directly the health of small animals such as mice can be applied to humans. Research studies of pesticides (toxic chemicals) on humans are not permitted, so it is nearly impossible to know with any certainty the toxic load that is fatal to humans. This is due to, in part, how research is done. How research is acquired on humans is that individuals who have had toxic exposure to pesticides go to clinical doctors for treatment, and these patients are used in clinical trials used for research studies. These studies are carried out, but there is much controversy over the size of the study or the validity of the results because of how the data were collected, as a result of an accident, not in a controlled laboratory setting. Therefore, it is difficult to arrive at a true and
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accurate measure of pesticide exposure that humans can safely tolerate. Cumulative Exposure In addition to this is the fact that most people are exposed to a number of the same pesticides over and over again. Recently, pesticide research has focused on the cumulative exposure. It was found in 1984 when the National Resources Defense Council (NRDC) analyzed pesticide residue in fresh produce in San Francisco grocery stores, that two or more pesticide residues were found in 42 percent of the samples. In addition, in 1985 and 1986, the Federal Dept. of Agriculture (FDA) found 7,000 residues on food of only 23 pesticides. What this means is people are being exposed to the same pesticides, over and over again, on different food products. This is what is known as “cumulative exposure”. However, at the present time, there is no method for measuring cumulative exposure to pesticides. Legislation on Pesticides Federal law requires all pesticides be evaluated to protect human heath, according to the 1996 law developed by Congress under the Food Quality Protection Act (FQPA). Stricter guidelines have been placed on pesticides that affect children. In addition, the cumulative risks of pesticides are now recognized. The Environmental Protection Agency (EPA) is working on a method for determining the cumulative risk of pesticides. The EPA requires test data from producers of pesticides so that researchers at the EPA can review the data and decide whether a pesticide can be registered for use. Researchers are careful to assess the health risks of these pesticides before they are approved. The EPA uses a four-step, human health-risk assessment developed by the National Research Council for pesticides to determine (1) if a pesticide is a hazard, (2) to determine the appropriate dose response, (3) to assess the type of exposure, such as through human consumption, touching, or inhaling (4) by arriving at an overall risk factor for each pesticide. The most recent EPA guidelines for carcinogenicity (potential to cause cancer) were presented in July 1999 in the Review Draft of the Guidelines for Carcinogenic Risk Assessment.
1360 Pharmaceutical Industry (Worldwide) Integrated Pest Control and Biopesticides Biopesticides are pesticides developed from natural methods. Biopesticides are made from natural materials. There are four types: microbial pesticides are where microorganisms (e.g., bacteria, fungus, or viruses) are used as the active ingredient. They are used to kill insect eggs of the offending insect, thereby eliminating them; plant-incorporated protectants (PIPs) are substances produced by the plants themselves that are genetically engineered to destroy them; biochemical pesticides are made from natural products found in the insect’s natural world. For example, insect sex pheromones (scent) are manipulated artificially so as to interfere with the natural mating cycle, thus preventing insects from multiplying. Integrated pest management (IPM) is used more recently, which combines using chemical pesticides with more natural methods such as rotating crops and using biopesticide methods. Protecting Ourselves from Pesticide Residue on Food Buy certified organic produce that is domestically grown. Wash all of the produce well before consuming it. Peeling fruits and vegetables can be even safer to get rid of pesticide residue. The pesticides that are on the foods we eat are too many to list here, but an excellent source for finding out is by reading For Our Kids’ Sake: How to Protect Your Child against Pesticides in Food by Mothers and Others for Pesticide Limits, a Project of the Natural Resources Defense Council. Common vegetable and fruits are listed with the pesticide used on it, the body organs it effects, and instructions on how to wash off the pesticides. SEE ALSO: Cancer (General); Drinking Water; Environ-
mental Protection Agency (EPA); Food Safety; Institute for Children’s Environmental Health (ICEH); Toxicology.
Bibliography. L. G. Copping, ed., The Biopesticide Man-
ual, 2nd ed. (British Crop Protection Council, 2001); Environmental Protection Agency, Pesticides, www.epa.gov/ pesticides/health/cancerfs.html (cited November 2006); Environmental Protection Agency, Pesticides Factsheet, www.epa.gov/pesticides/factsheets.html (cited November 2006); Brenda Eskenazi, et al., “In Utero Exposure to DDT and DDE and Neurodevelopment among Young Mexican
American Children,” Pediatrics (v.118, 2006); Mary L. Flint and Driestadt, Natural Enemies Handbook: The Illustrated Guide to Biological Pest Control (University of California Press, 1998); R. Krieger, ed., Handbook of Pesticide Toxicology (Academic Press, 2001); Natural Resources Defense Council, For Our Kids’ Sake: How to Protect Your Child against Pesticides in Food (Natural Resources Defense Council, 1998); Pesticides: EPA’s Formidable Task to Assess and Regulate Their Risks (Government Accounting Office, 1986); C. D. S. Tomlin, ed., The Pesticide Manual, 13th ed. (British Crop Protection Council, 2003); G. W. Ware and D. M. Whitacre, The Pesticide Book, 6th ed. (MeisterPro Information Resources, 2004). Kimberly Fujioka University of California–Berkeley
Pharmaceutical Industry (Worldwide) The pharmaceutical industry is one of the most important and powerful industries in the world, with global sales of pharmaceuticals expected to reach some $700 billion in 2007. In affluent societies, pharmaceutical treatment is now the main form of medical intervention for the majority of illnesses and most people take many prescribed medicines over the course of their lives, with pill use typically increasing markedly by the time individuals are aged 60 or over. The industry is dominated by a small number of large multinational companies located in the United States and Europe, with the top 10 companies now accounting for over half of pharmaceutical sales worldwide. The dominance of the leading companies has resulted from a period of consolidation with numerous mergers and acquisitions taking place, particularly over the last two decades. This has increased the companies’ power and their market impact. At the same time, however, there has also been considerable change and diversification in the industry. On the one hand, an emergent group of biotechnology companies has become of increasing importance to the generation of new product ideas and innovations, and the relations between biotechnology and pharmaceutical companies have developed and strengthened. On the other hand, there is growing
competition from drug companies in middle-income countries, especially China and India, with some of them starting to challenge the market dominance of Western companies. In 2005, half of the top 10 leading pharmaceutical companies were located in the United States, which has by far the largest market for pharmaceuticals accounting for over half of worldwide sales by expenditure. The largest of the U.S.-based companies was Pfizer, which secured this position by taking over Warner-Lambert in 2000 and Pharmacia in 2003. Other U.S. companies in the top 10 in 2005 were Johnson & Johnson, Abbott Laboratories, Merck & Co, and Bristol-Myers Squibb. The remainder of the top 10 have European headquarters. The largest of these in 2005 was GlaxoSmithKline, the outcome of a merger between the British companies Glaxo and Burroughs Wellcome in 1995, followed by the merger of GlaxoWellcome with the Anglo-American SmithKline Beecham in 2000. The next largest was Sanofi-Aventis, the product of a merger between the German company Hoechst and the French Rhone-Poulenc in 1999, which created Aventis, and then a further merger of Aventis and the French company Sanofi-Sythelabo in 2004. The remaining three in the top 10 in 2005 were the Swiss companies Roche and Novartis—the latter the product of a merger between two Swiss companies, Ciba and Sandoz in 1996—and AstraZeneca, which resulted from a merger between the British Zeneca, and the Swedish Astra in 1999. Leading companies are highly commercial and highly profitable, amongst the most profitable companies in the world, currently only topped by the oil industry and banking. Most of their profits come from patented drugs—that is, drugs based on an idea or innovation whose ownership by the company has been successfully registered—although some of the companies have significant portfolios of over-thecounter (OTC) drugs and medicines that do not require a prescription as well as other health-related products. Patents are typically granted for 20 years (although they can be extended under certain restricted circumstances), and during that time, no other company can produce a drug using the patented chemical composition or process. This monopoly position enables the company to charge a relatively high price for the product.
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A brand name is also obtained for the drug, a name that can be retained and cannot be used by others as long as it is registered, which can help the company to retain some market advantage even when a patent expires. Hence, getting a drug known by its brand rather than its chemical name is important, as in the case of drugs such as Prozac® and Viagra®. However, once a patent ends, other companies are free to produce a generic version under another name, and the competitive market does help to drive prices down. Given the far greater profits from patented than generic drugs, leading companies need to have other new drugs in their pipeline to replace profitable drugs that are about to lose their patents, although one or two of the leading companies, notably Novartis, are beginning to give more weight to generic drugs in their product portfolios. Patents extend only to the jurisdictions in which they are obtained, an issue that in an era of global trade has led to difficulties for leading companies seeking worldwide protection for their patents. However, Western companies have used the organizations regulating global trade, in particular the World Trade Organization (WTO), to try to secure patent protection across the world via the mechanism of trade-related aspects of intellectual property rights (TRIPs) agreements, acceptance of which is made a condition of WTO membership. This is having a significant impact on expanding pharmaceutical companies in Asia, particularly in China and India. These companies have tended to concentrate much of their pharmaceutical production on drugs that are out of patent, but have also produced their own versions of patented products. With the growing need of middle- and low-income countries to become WTO members, the freedom of these companies to produce copies of patented drugs is being restricted, an issue that has come into particular prominence given the spread of human immunodeficiency virus (HIV)/AIDS in low-income countries and the high price of Western antiretroviral drugs. Nonetheless, the larger companies in China and India are starting to invest in research and development (R&D) and produce their own patentable medicines as well as low-cost generic drugs that are beginning to enter Western markets. For instance, the largest Indian pharmaceuticals company, Cipla, had global sales of a little over $3 billion in 2005 and by
1362 Pharmaceutical Industry (Worldwide) 2002/03 had sales to the United States of just over a quarter of a billion dollars. The commercial orientation of leading Western companies is also manifest in other ways. One is the character of product development. R&D is a major expenditure in leading companies accounting for around 13 to 19 percent of costs. R&D costs are frequently used to justify patent protection and the high prices charged for particular drugs, with companies arguing that they need to recoup R&D costs to be able to invest in new drugs, although there is evidence that the average cost of bringing new drugs onto the market has been overstated. However, product development in the leading companies is not solely or exclusively determined by medical need measured by the severity of the illness and the extent of suffering. Instead much R&D tends to focus on potentially the most profitable products: those that can be patented and will be used by large numbers of individuals for long periods of time—for illnesses or conditions that are held to need longterm treatment. Such products may be designed to treat conditions considered to be indicative of potential illness rather than preexisting illness, and drugs are now widely used for prevention as well as for the relief of symptoms and efforts at cure. The importance of products that are used long term to market success can be seen very clearly in the list of patented products that generate the highest profits for leading companies. Statins—treatments designed to lower cholesterol levels—which are prescribed to prevent heart disease, are a highly profitable group of drugs, and data for 2005 show Lipitor®, produced by Pfizer, generated the highest revenues of any drug. Another statin, Zocor®, produced by GlaxoSmithKline, was also in the top 10 in 2005. This is a reflection of market competition within the industry and the tendency for companies to put considerable effort into creating products that are similar to those produced by other companies, yet sufficiently different, so that they do not infringe patent protection— so called “me-toos”—to get a share of the market. The next highest sales after Lipitor were generated by Plavix®, a drug for the treatment of heart disease, produced by Bristol Myers Squibb. In the 1990s, the most profitable drugs were the antidepressant selective serotonin reuptake inhibitors (SSRIs), but the patents from these drugs are now expiring.
Given the high revenues that can be derived from drugs that are taken long term, pharmaceutical companies have an interest in broadening the boundaries of disease, not only through the identification of new health problems but also by changing the boundaries of how severe a problem needs to be for it to be deemed to merit pharmaceutical intervention. The example of the identification of high cholesterol levels as a condition needing treatment is illuminating. A range of studies show that high cholesterol levels, as well as a number of other factors, are associated with possible heart problems and strokes, although there is now also widespread recognition that a differentiation needs to be made between two types of cholesterol—“good cholesterol” and “bad cholesterol.” In 1987, the first statin, Mevacor®, produced by Merck and directed at lowering cholesterol, was licensed. Since then, sales of statins have increased almost exponentially. A major factor contributing to this expansion has been changing definitions supported by the industry as to what constitutes “high” cholesterol levels that merit intervention. This has put large numbers of healthy people onto daily drug regimes, which may continue for the rest of the lives even though no sickness is evident or experienced. Some commentators have argued that any individual over 55 would benefit from taking statins; others contend that the benefits of statins for those without heart problems are limited and the risks higher than usually stated, and that alternative interventions such as changes in diet and exercise would be far preferable. The strong commercial orientation of pharmaceutical companies and the potential profitability of a drug that can be recommended for large numbers of people for long periods of time also means that the companies tend not to invest in R&D for conditions that offer potentially fewer profits because they are short term, or very rare, or are uncommon in affluent societies. Cancer has an interesting status in this context. Long an illness with high mortality rates, the improvements in medical treatments including surgery, radiotherapy, and chemotherapy in recent decades have meant higher survival rates and the need for longer-term drugs that help to keep cancer, once treated, at bay. In addition, the increase in life expectancy has meant more individuals experience can-
cer at some point in their lives. Consequently, the market for cancer drugs has expanded considerably, investment has increased, and they now offer potentially more in terms of profits and are beginning to feature among the group of products generating considerable revenues. Because of the bias of leading pharmaceutical companies, certain uncommon illnesses have had to be defined as “neglected diseases” for which governments and charities have had to provide additional funds in order to encourage the companies to carry out research and develop new products for their treatment. This also applies to a range of common, often fatal, illnesses that are relatively rare in Western countries but very common in poorer ones, where companies have made little investment in new products. An example is malaria where it has required intervention by charitable bodies such as the Gates Foundation to secure investment into new forms of vaccination and treatment. The commercial orientation of the industry is most visibly reflected in its intensive marketing, with estimates of spending by leading companies on marketing varying around 15 percent—almost as much, or more depending on the estimates, as their spending on R&D. Countries vary as to whether they permit drugs that require a medical prescription to be directly advertised to patients. Direct-to-consumer (DTC) advertising is permitted in the United States but not in many European countries. However, there are many alternatives to this form of marketing. Press releases about new drugs can be widely circulated by companies and create considerable public knowledge of them—as in the case of Viagra—and such tactics can help to generate demand. Moreover, advertising to doctors is permitted even where DTC advertising is not. The blandishments of the industry are well known. Pharmaceutical representatives visit doctors and their surgeries providing information about their products and leaving behind pens, paper pads, and mugs, as well as free samples to remind them of their products. The industry also pays for seminars and conferences, sometimes covering or contributing to travel and hotel costs for scientific meetings in attractive locations. Equally important, the industry funds medical research, some of it postapproval testing of its own products, and it is now widely accepted that because
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of the potential biases that can result, the source of funding should be indicated when results are published, although not all adhere to this practice. Pharmaceutical companies are also known to ghost-write papers for medical researchers, which are then published in prestigious journals. An important marketing technique directed at doctors, and at the public through press releases, is to use data on the distribution of illness to emphasize how much of it is undetected and in need of treatment. In this, the industry and the medical profession may have shared interests. Doctors are usually very aware of the tactics used by the industry to support their products and increase their markets, but as professionals, they tend to think that they can resist the blandishments of the industry. Yet, the evidence does not support this view and one of the reasons for this, apart from the general difficulty of resisting the power of advertising, is that the profession, like the industry, has a clear interest in pharmaceutical prescribing. The fact that certain products need to be medically prescribed, by giving medical professionals a clear monopoly over access to certain pharmaceutical products, at the same time gives them an interest in the success of the industry, because its products help to maintain and strengthen their professional power. More recently, nurses are being allowed to prescribe a limited set of drugs, but their powers are highly restricted compared with those of doctors. Since the beginning of the 20th century, there have been efforts by governments to regulate the pharmaceutical industry in order to protect the interests of patients and consumers. Determining which products have to be medically prescribed constituted one of the earliest features of this regulation. Such efforts were considerably strengthened in advanced industrial countries following the scandal surrounding the drug thalidomide in the early 1960s by the establishment of bodies to approve the licensing of new drugs and the specification of clear testing regimes that needed to be followed if a drug is to be approved for the market. However, there is considerable variation worldwide in the degree to which the industry is regulated and also in the degree of independence of agencies from the industry and government over time. It is not always easy to find individuals who do not have strong links with the industry to serve as members and some
1364 Pharmaceutical Industry (Worldwide) would argue that their expertise is necessary. Moreover, governments often have an interest in supporting the industry, which may be a source of jobs and wealth in the national economy, as well in trying to secure good access to drugs at reasonable prices, and companies often use lobbyists to put pressure on governments to support particular policies. Worldwide, the most important drug approval agency is the U.S. Food and Drug Administration (FDA) because of the importance of the U.S. market to pharmaceutical sales. However, as with other drug agencies, its degree of independence fluctuates. Testing to secure a license for a drug typically involves initial testing on animals, then on healthy adults, and then randomized control trials involving patients with the relevant illness and control samples. Much of it, although frequently funded by the industry, is now carried out by specialist companies rather than in-house. Testing focuses on safety and effectiveness with the aim being to establish that a drug is sufficiently safe and effective to be released onto the market and constitutes a form of risk–benefits analysis. It is common to distinguish two aspects of safety: the severe “adverse drug reactions” that may involve death, and drug side effects. Side effects are the consequences of taking a drug that may be unpleasant or disagreeable but are such that they tend to be considered acceptable for the benefits, as the term itself indicates. An example would be the drowsiness associated with antihistamines. However, although it may be enough to provide a preliminary assessment of the safety and value of a drug, the testing of drugs before they are licensed is in fact quite limited. Preapproval testing does not require drugs to be taken by patients for very long periods, although once approved, they may, as in the cases of statins, antidepressants, and anti-ulcer drugs, be taken for many years and some problems may only emerge with long-term use. In addition, for good reasons, drugs are usually tested on adult men rather than children, women, or the elderly, yet the metabolisms of these groups differ considerably from those of adult men. The lack of testing on the elderly is especially a problem, because in affluent societies, those aged 60 and over account for close on half of all pharmaceutical use. There is also little systematic testing of the interaction effects
between drugs, yet among the elderly, multipharmacy is particularly common. Equally importantly, there is no real attempt to assess the boundaries of the drug’s value—whether it is useful for the treatment of more marginal, less severe cases or to identify the point where the risk–benefit equation changes. Yet, once approved, a drug is likely to be deemed effective without much in the way of qualification and is often used more widely in situations where it may have little value and may even have a detrimental effect, as proved to be with the use of the antidepressant Seroxat to treat depression in children. The value of particular drugs if used more widely only emerges with time and frequently is not properly assessed through randomized trials. Moreover, as noted, much of the drug testing is funded and controlled by the pharmaceutical industry and there is clear evidence that testing carried out by independent bodies produces results less favorable to the drugs than those carried out under the auspices of the industry itself. Many potential products fail in the early or later stages of preapproval testing and this can be a matter of great disappointment to the companies. Indeed, notwithstanding the contribution of biotechnology companies to product innovation, the number of innovative products being approved has been declining. On the other hand, some drugs do secure a license, but problems then emerge and the drug is either withdrawn or the license revoked. Such products include Opren/Oraflex a treatment for arthritis; Halcion, a tranquilizer which had its licensed revoked in some European countries; and the statin Baycol. Some regulation and control of the industry can also be affected through negotiations over the prices of drugs either by governments or medical insurers. In the United States, the introduction of managed care has led to considerable efforts to reduce the charges made by drug companies for their products and to encourage a shift from the use of patented to generic alternatives, and a similar change has occurred in other countries, although governments and insurers have not always managed to secure very good prices for drugs. There can be little doubt of the positive impact of many 20th-century pharmaceuticals on the health of populations, although there is also clear evidence that improvements in nutrition and sanitation have also
Pharmacist
had a very important role to play in increasing life expectancies. Moreover, the commercial orientation of the industry means that the reduction of suffering and illness are by no means always at the forefront of the industry’s activities. In addition, some would argue that the increasing reliance of pharmaceutical products to deal with a range of problems directs attention away from alternative forms of intervention, including alternative preventive strategies that can promote health and prevent illness. SEE ALSO: Pharmacist; Pharmacologist; Pharmacology. Bibliography. J. Abraham, Science, Politics and the Phar-
maceutical Industry (UCL Press, 1995); J. Abraham and G. Lewis, Regulating Medicines in Europe (Routledge, 2000); J. Abraham and J. Sheppard, The Therapeutic Nightmare: The Battle over the World’s Most Controversial Sleeping Pill (Earthscan, 1999); J. Busfield, “Pills, Power, People: Sociological Understandings of the Pharmaceutical Industry,” Sociology (v.40/2, 2006); A. Harrison, Getting the Right Medicine? (King’s Fund, 2003); IMS Health, “Changing Market Dynamics in 2007,” http://open.imshealth.com/ webshop2/IMSinclude/I_article_20061204a.asp (cited March 13, 2007); IMS Health, “Countries and Regions,” http://open.imshealth.com/dept.asp?deptpercent5Fid=3 (cited March 13, 2007); L. L. Kjaegard and B. Als-Nielson, “Association between Competing Interests and Authors’ Conclusions: Epidemiological Study of Randomised Clinical Trials Published in the BMJ,” British Medical Journal (v.325, 2002); J. Lexchin et al., “Pharmaceutical Industry Sponsorship and Research Outcome and Quality: Systematic Review,” British Medical Journal (v.326, 2003); P. Malhotra and H. Lofgren, “India’s Pharmaceutical Industry: Hype of High Tech Take Off,” Australian Health Review (v.28, 2004); R. Moynihan and A. Cassels, Selling Sickness: How Drug Companies Are Turning Us All into Patient (Allen & Unwin, 2005); National Institute for Health Care Management, Changing Patterns of Pharmaceutical Innovation (National Institute for Health Care Management Foundation, 2002); Pirmohamed et al., “Adverse Drug Reactions as a Cause of Admission to Hospital: As Prospective Analysis of 18,820 Patients,” British Medical Journal (v.329, 2004). Joan Busfield University of Essex
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Pharmacist A pharmacist is a health professional who practices the art and science of pharmacy, a chemical science and profession concerned with the preparation and dispensing of medications. The traditional function of a pharmacist is to receive requests for medicines from a medical professional, usually a physician, in the form of medical prescriptions and dispense the medications to patients and counsel them on the proper use and side effects of the drugs. Pharmacists have increasing areas of expertise and are a critical source of medical knowledge in a variety of settings throughout the world. Pharmacist Licensure To practice pharmacy, a pharmacist must be licensed by the relevant statutory body, which governs the registration and practice of pharmacy within the territory of its jurisdiction. A basic requisite for pharmacist licensure is a degree in pharmacy (Bachelor of Pharmacy or Doctor of Pharmacy; PharmD) from an accredited university. Individuals seeking pharmacist licensure are often required to complete a certain number of experiential hours in a pharmacy, under the supervision of a registered pharmacist.
Pharmacists have increasing areas of expertise and are a critical source of medical knowledge in a many settings throughout the world.
1366 Pharmacoepidemiology Training and Practice Pharmacists are usually trained in the fields of anatomy, physiology, biochemistry, pharmacology, medicinal chemistry, pharmacy practice, pharmaceutics, pharmacy law, pharmacokinetics, and medication compounding. The contemporary role of the pharmacist has expanded, in some settings, from a purely compounding and dispensing role to include functions such as reviewing and monitoring medication regimens, provision of non-prescription medicines, drug dosing in renal and hepatic failure, pharmacokinetic evaluations, and medication therapy management. Many universities are even reforming curricula to increase emphasis in fields such as pharmacotherapeutics, clinical pharmacy, nuclear pharmacy, disease state management, pharmacoeconomics, pharmacoepidemiology, and pharmacogenomics. SEE ALSO: American Pharmaceutical Association (APhA);
Pharmacy.
BIBLIOGRAPHY. Judith E. Thompson and Lawrence Davi-
dow, A Practical Guide to Contemporary Pharmacy Practice (Lippincott Williams & Wilkins, 2003); Fred B. Gable, Opportunities in Pharmacy Careers (McGraw-Hill, 2003); APhA, “American Pharmacists Association Homepage,” www.aphanet.org (cited October 2006). Joshua J. Gagne, Pharm.D. Jefferson Medical College
Pharmacoepidemiology Pharmacoepidemiology is the study of the utilization and effects of drugs in large numbers of people, and is usually considered in the context of drug safety. As the name implies, it may also be thought of as the application of epidemiology to the field of clinical pharmacology. Bridging Pharmacology and Epidemiology Clinical pharmacology, which is the study of how drugs interact with humans to produce beneficial or deleterious effects, seeks to provide a risk benefit assessment for individual patients. Epidemiology,
which is the main science behind the field of public health, is the study of the distribution of disease and the factors affecting the health and illness of populations. Applying epidemiological methods to clinical pharmacology allows one to provide an estimate of the probability of beneficial effects in populations, or conversely, the probability of adverse effects in populations. Pharmacoepidemiology benefits from the methods developed in general epidemiology, which has its origins in the study of infectious diseases in large populations. Researchers usually perform pharmacoepidemiological studies on drugs once they are marketed. Pharmacoepidemiology is a rigorous science, but has limitations. For example, although one can use pharmacoepidemiological methods to determine whether an association between a drug exposure and an outcome exists, one cannot ascertain a causal relationship, nor can one use this science to explain the nature or mechanism of adverse drug reactions or beneficial effects. Importance and Application Pre-marketing clinical studies usually test an investigational new drug in several hundred to several thousand people. Once a drug is approved and marketed, tens of thousands to millions of people may be exposed to the medication. Even though one of the primary objectives of the drug development and approval process is to ensure that drugs are safe before marketing commences, conventional randomized clinical trials are often inadequate to detect and assess rare adverse events associated with exposure to the drug. For example, if a drug causes kidney failure in one out of 1,000 patients, clinical trials conducted in relatively few patients may not detect this serious adverse effect. If 100,000 patients consume the drug annually once it is marketed, kidney failure will occur in a considerable number of patients and this information is essential to protecting the public’s health. Post-marketing drug surveillance, which is often used interchangeably with pharmacovigilance, is the most common application of pharmacoepidemiology. Pharmacovigilance is a process of continual monitoring for adverse effects of drugs that are already on the
Pharmacogenetics
market and refers almost exclusively to spontaneous reporting systems, which allow regulators and healthcare providers to report adverse drug reaction to a central agency. The central agency can then combine reports from many sources to produce a more informative safety profile for the drug product than could be done otherwise. One example is the MedWatch system maintained by the FDA in the U.S. Training and Practice The study of pharmacoepidemiology typically involves substantial didactic work in general epidemiology, biostatistics, and health services research, and usually succeeds more clinically oriented training in medicine, pharmacy, pharmacology, or related disciplines. Pharmacoepidemiologists usually work as researchers in regulatory agencies, in the pharmaceutical industry, in contract research organizations, or in consulting firms; or as researchers and professors in academia. SEE ALSO: Drug and Medical Device Safety; Epidemiol-
ogy; Food and Drug Administration (FDA); International Society for Pharmacoepidemiology (ISPE); Pharmacology.
Bibliography. Brian L. Strom, Pharmacoepidemiology
(John Wiley & Sons, 2005); Committee on the Assessment of the US Drug Safety System, Alina Baciu, Kathleen Stratton, Sheila P. Burke, The Future of Drug Safety: Promoting and Protecting the Health of the Public (The National Academies Press, 2006); FDA, “U.S. Food and Drug Administration Homepage,” www.fda.gov (cited October 2006); “WHO Programme for International Drug Monitoring,” www.who-umc.org (cited October 2006). Joshua J. Gagne, Pharm.D. Jefferson Medical College
Pharmacogenetics The term pharmacogenetics is generally held to be a study of the genetic variation that results in people responding differently to taking the same drug, with the term pharamagenomics, often used interchangeably with pharmacogenetics, being the far broader appli-
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cation of genomic technology to new drug discoveries with the study of the entire genome. Since ancient times, it has been recognized that people with the same ailment may take the identical medicine and have different responses. However, it was research in the 1950s that led to a scientific understanding of the reasons for these differences, and this, in turn, led to the development of the field of pharmacogenetics. It came from a greater understanding of the concept of the human genes, and this has been enhanced by the recent studies of the genomes. Doctors have generally felt that a particular medicine should be prescribed for a specific ailment, allowing for factors such as cost, accessibility, allergies, and the like. With scientific testing of drugs on large numbers of people before they can be prescribed by doctors in most countries, it has been possible for pharmaceutical companies to collect information on the possible side effects and these have to be listed when the drug is patented, and are then detailed in the pharmacopeia. Although some drugs cannot, of course, be used for children, pregnant women, and the elderly owing to the drugs’ toxicity or their side effects, it has been realized that some people might have a genetic predisposition against the effects of a particular drug or one specific medicine may lead to a much more heavily toxic effect in one person than another. The field of pharmacogenetics has involved testing very large numbers of people on certain prescription medicine, while at the same time collecting information on their genes. Some earlier experiments have shown that the people who reacted best to particular drugs had similar genes, with work continuing to try to find general conclusions to avoid having to retest all prescription drugs again to work out their success or lack thereof with people with a particular gene makeup. SEE ALSO: Pharmacogenomics; Pharmacopeia/Pharma-
copoeia.
Bibliography. A. Abott, “With Your Genes? Take One of
These, Three Times a Day,” Nature (v.425, 2003); W. E. Evans and H. L. McLeod, “Pharmacogenomics—Drug Disposition, Drug Targets and Side Effects,” New England Journal of Medicine (v.348, 2003); R. Weinshilboum, “Inheritance
1368 Pharmacogenomics and Drug Response,” New England Journal of Medicine (v.348, 2003).
Pharmacology: Therapeutic Principles in Practice (Lippincott Williams & Wilkins, 2005).
Justin Corfield Geelong Grammar School, Australia
Justin Corfield Geelong Grammar School, Australia
Pharmacogenomics
Pharmacologist
Pharmacogenomics is a branch of pharmaceutics which covers the influence of how genetic variation can affect drug responses in humans by correlating the drug’s efficacy and toxicity with gene expression or single-nucleotide polymorphisms. The aim of this is to help researchers develop a comprehensive way of optimizing the use of drug therapy to ensure that it is prescribed in the most effective manner, to maximize its effects and also minimize any adverse reactions. To achieve the best possible drug therapy—some have referred to it as personalized medicine—researchers have had to tabulate the effect of each drug against the genotype of each person being prescribed that drug. With genes from people differing slightly in their nucleotide (DNA base) content, this process is obviously extremely time-consuming, and expensive in terms of resources. As a result it is initially used to deal with drugs which generally have highly toxic effects and/or are also very expensive. With a study published in the Journal of the American Medical Association in 1998 that four years earlier that there were some 2.2 million serious adverse drug reactions in the United States, accounting for up to 100,000 deaths. This undoubtedly means that pharmacogenomics will be important in the years to come at reducing this toll, and ensuring medication is more appropriate to the individual patients.
A pharmacologist is a medical doctor who is involved in pharmacology—the study of how substances interact with living organisms and how this then leads of a change in function. There are many associations around the world involved in training and accrediting pharmacologists, the best known being perhaps the American Society for Pharmacology and Experimental Therapeutics Inc., founded in 1908, which publishes the Journal of Pharmacology and Experimental Therapeutics each month; and the British Pharmacological Society, founded in 1931, which publishes the British Journal of Clinical Pharmacology each month and the British Journal of Pharmacology twice monthly. The earliest known pharmacologist is undoubtedly Crateuas who was a physician to King Mithradates VI of Pontus, his surviving drawings being the earliest known botanical pictures. Other prominent pharmacologists include Joseph Freiherr von Mering who also worked as an experimental pathologist; the American pharmacologist and physiological chemist John Jacob Abel; the Briton Sir Henry Dale who shared the Nobel Prize for Physiology or Medicine in 1936 with the German pharmacologist Otto Lowei for their work on the chemical transmission of nerve impulses; American biochemist and pharmacologist Julius Axelrod who shared the Nobel Prize for Physiology or Medicine in 1970 with British biophysicist Sir Bernard Katz and Swedish physiologist Ulf von Euler for the identification of an enzyme that degrades chemical neurotransmitters within the nervous system; Earl W. Sutherland Jr. who was awarded the Nobel Prize for Physiology or Medicine in 1971 for the isolation of cyclic adenosine monophosphate; the Scotsman Sir James Black; George H. Hitchings and Gertrude B. Elion who won the Nobel Prize for Physiology or Medicine in 1988 for their development of propranolol and cimetidine; pharmacologist Alfred G. Gilman
See Also: Pharmacogenetics; Pharmacopeia/Pharmaco-
poeia.
Bibliography. “One size Does Not Fit All: The Prom-
ise of Pharmacogenomics,” http://www.ncbi.nlm.nih.gov/ About/primer/pharm.html; Mohan K. Raizada et al, Cardiovascular genomics (Humana Press, 2005); Sumner J. Yaffe and Jacob V. Aranda (eds.), Neonatal and Pediatric
Pharmacology
who shared the Nobel Prize for Physiology or Medicine in 1994 with biochemist Martin Rodbell for their work in discovering G proteins; and the Swede Arvid Carlsson who, along with Paul Greengard and Eric Kandel won the Nobel Prize for Physiology or Medicine in 2000 for research that established dopamine as one of the main neurotransmitters in the brain. SEE ALSO: Axelrod, Julius; Pharmacology. Bibliography. The American Society for Pharmacology
and Experimental Therapeutics Inc., www.aspet.org (cited July 2007); The British Pharmacological Society, www.bps. ac.uk (cited July 2007). Justin Corfield Geelong Grammar School, Australia
Pharmacology Pharmacology is the science and practice of developing and administering chemicals as agents in the treatment of diseases. Pharmaceuticals are drugs used as to treat disease, yet they are also abused for “recreational” purposes or used for criminal purposes. The discipline of pharmacology comprises more than just the chemistry of drugs. It also includes the study of how living organisms react to exposure to drugs. The interactions may be anti-pathogenic, therapeutic, or toxic. The later area of study is toxicology, or the study of poisonous effects. Diseases afflict plants, animals and humans. The use of chemical agents to treat disease is ancient. Folklore among tribal peoples such as the American Indians and traditional medical systems such as those of China and India developed a wide range of pharmaceuticals. The ancient Greeks, led by Galen, Hippocrates and others, developed medicine in a systematic philosophical manner. Greek medical science was inherited by the Arabs and their converts following the Arabian conquests. Within roughly a century the entire corpus of Greek medical science was translated into Arabic with the aid of Christian and Jewish physicians. To it was added the medical knowledge of the Persians and the physicians of India.
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The medical knowledge of the Islamic world was transmitted to the West during and after the Crusades from sources in the Levant and in Spain. Some new medical knowledge began to filter back to Europe during the voyages of sailors in the age of exploration. They also brought back new disease. The herbal remedies and new diseases were a stimulus to research into biology, diseases, and medicinal remedies. Probably the most important advance was the development of vaccines following Edward Jenner’s (1749-1823) discovery that inoculation with cow pox protected against small pox. Virology, the study of viruses, developed in the early 1900s from work done on viruses by Frederick William Twort and Felix d’Herelle. The growing understanding of viruses enabled vaccines to be developed to combat them. With the deadly global influenza pandemic at the end or World War I the need became acute. The advances in chemistry of the 19th century bore dramatic fruit for the pharmaceutical industry after 1900. The textile industry was the first to undergo industrialization and adoption of the factory system during the Industrial Revolution. Its products had been dyed with natural dyes until modern chemists began the development of modern sulfur dyes. The chemists, many of whom were Germans working with coal, were able to develop new dyes for coloring fabrics. However, it was also noticed that some microbes took the dyes into their systems, often with fatal effects. The modern pharmaceutical industry has since grown into a global multi-billion dollar giant. Today the competition to develop new drugs is intense and there are strong economic and political motivations to advance new medicines. There have also arisen in the United States, and to a similar degree in other countries, government agencies that regulate the production and distribution of medicines. One obvious reason is drug abuse. Another is to protect the public for charlatans. Quackery abounded in the United States in the 19th century. Numerous “snake oil salesmen” traveled the country selling remedies that were often simple mixtures of alcohol and opium. Today the Food and Drug Administration regulates pharmaceuticals and enforces standards set by the United States pharmacopoeia. In Europe, the European Union’s agency for regulating the development and application of pharmaceuticals is the European
1370 Pharmacology Medicines Agency (EMEA). It also evaluates drugs developed in Africa and the Middle East. Medicinal drugs are usually put into a dozen categories. Those used to treat humans are classified according to the way that they affect the human body. They can also be classified by their chemical makeup, the disease they fight, by the affect they have on the heart or blood vessels, or by their affect on the nervous system. Manufactured drugs have three names: a scientific chemical name, a manufacturer approved generic name, and the brand name of its manufacturer. Penicillin, an antibiotic, is probably the most famous of the infection fighting drugs. Others antibiotics include the sulfa drugs (sulfonamides). Vaccines, antiserums, and immunoglobulins are infectious disease preventing drugs. These drugs work by stimulating the body to create antibodies to fight potential diseases such as measles, small pox, polio and others. When the antibodies combine with the antigens of the bacteria or virus they render them harmless. Antiserums and immunoglobulins also neutralize the antigens of the infectious disease. They provide protection against the antigens of microbes that cause diseases such as diphtheria, tetanus, hepatitis or rabies. The cardiovascular drugs affect the heart or blood vessels by normalizing irregular heartbeats, stimulating the heart’s beat so that more blood is pumped, enlarge small blood vessels, or in the case of hypertensive drugs treat high blood pressure. The nervous system is affected by drugs such as analgesics, anesthetics, hallucinogens, stimulants, and depressants. The analgesic drugs relieve pain, but because some contain a narcotic they are subject to abuse. Narcotics (analgesia plus a sedative) include codeine, heroin, and morphine. Aspirin is a non-narcotic analgesic. The general anesthetics are drugs that produce a state of sedation that blocks sensations. Ether halothane and thiopental have been used in surgery. Hallucinogens or psychedelic drugs such as LSD (lysergic acid diethylmide), marijuana, and mescaline produce hallucinations. Mushrooms and other plants are often grown illegally and are known to cause drug addiction. Stimulant drugs affect the nervous system. They can reduce fatigue, stimulate the kidneys, or produce other affects. Caffeine, cocaine, and amphetamines are drugs in this category. The last two have been subject to abuse.
Depressants cause the nervous system to become relaxed so that tension and worry are diminished. Tranquilizers (anti-anxiety agents), alcohol, and sedative-hypnotics are depressants. Other depressants include benzodiazepines and barbiturates. Non-barbiturate sedatives include chloral hydrate and paraldehyde. Their recreational drug abuse is widespread. Other drug types include the diuretics, hormone therapy drugs, vitamins and immunosuppressive drugs. Drugs used in chemotherapy involve anti-tumor (antineoplastic) chemicals. Drug abuse has two major forms: recreational and medicinal. The recreational abuse of drugs has created criminal empires. In areas such as Burma or Afghanistan where opium is produced, or South America where the coca leaf grows, crops have been subjected to efforts at eradication that involve the use of defoliants. The impact on the natural environment has been negative. The medicinal abuse of drugs is probably even more widespread. Failure to handle medicines properly has contributed to drug resistance to bacteria strains. It has also led to a race to continually produce new drugs against “stronger bugs.” Another form of medicinal drug abuse is its use to prevent disease of to stimulate animal growth, thereby increasing meat production. The side effects have been negative in a number of cases. Today the pharmaceutical industry is searching the globe for any plant or lifeform that may have medicinal benefits. The early 20th century distain for folk remedies has been replaced by a thorough search of the earth for anything with medicinal promise. The industry stands to gain billions of dollars from new cures. The notion of throughput is now being using in the pharmaceutical industry. Advances in several sciences have lead to the development of many new drugs. The human genome project has increased knowledge of human genes immensely. Because there are thousands of units of proteins in human DNA, the knowledge is now available to seek new receptors for possible medicines. The development of robot chemistry at the end of the 20th century has made it possible to assemble vast numbers of chemicals that can then be tested on the thousands of receptor sites in proteins. Where previously a skilled chemist would have done well to develop one or two chemicals a week, these new tech-
niques allow a single chemist to develop thousands of new compounds in the same time. The screening of such an enormous number of chemical compounds against a vast number of receptor sites would have needed armies of researchers just a few decades ago. Now using high throughput screening technology, thousands of chemicals can be tested against thousands of receptor sites. Many new companies have arisen that synthesize computerized chemical libraries containing millions of different chemicals. Pharmaceutical companies will often buy high throughput technology systems in order to test for some target receptor that is of interest. Using the computer’s database of chemical formulas, it is possible for a company to screen up to a million different chemicals against a chosen receptor site in only a month. However, out of every five thousand possible drugs only about one makes it to the market. Even then recalls due to unexpected side effects are not uncommon. To develop a new medicine typically takes three or more years and is very expensive. Once the medicine is produced it has to undergo clinical trials that can take and additional three to six years. Sometimes there are accidental discoveries from side effects. Most side effects will eliminate a drug from use, but in the case of Viagra, it stimulated a whole new range of erectile dysfunction medications. See Also: Pharmacologist; Prescription Drug Abuse. Bibliography. George M. Brenner and Craig W. Stevens,
Pharmacology (Elsevier Health Sciences, 2006); Howard Brody, Hooked: How Medicine’s Dependence on the Pharmaceutical Industry Undermines Professional Ethics (Rowman & Littlefield Publishers, Inc., 2007); Richard A. Epstein, Overdose: How Excessive Government Regulation Stifles Pharmaceutical Innovation (Yale University Press, 2006); Sved Imtiaz Haider, Pharmaceutical Master Validation Plan: The Ultimate Guide to FDA, GMP, and GLP Compliance (CRC Press, 2001); Leslie Iversen, Drugs: A Very Short Introduction (Oxford University Press, 2001); Bertram G. Katzung, Basic & Clinical Pharmacology (McGraw-Hill, 2006); Howard L. McLeod, ed., Handbook of Anticancer PharmacoKinetics and Pharmacodynamics (Springer-Verlag, 2004); Michael A. Santoro and Thomas M. Gorrie, eds., Ethics and the Pharmaceutical Industry (Cambridge University Press, 2005); Sonia Shah, Body Hunters: Testing New Drugs on the World’s Poorest Patients
Pharmacopeia/Pharmacopoeia
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(The New Press, 2006); Walter Sneader, Drug Discovery: A History (John Wiley & Sons, 2004); Linda Waide and Berta Roland, Pharmacology Made Easy for NCLEX-RN: Review and Study Guide (Chicago Review Press, 2001). Andrew J. Waskey Dalton State College
Pharmacopeia/Pharmacopoeia The pharmacopoeia is a book that contains details on directions for the making of medicines, thus showing the ingredients and their strengths in the formula and allowing doctors to choose the most suitable medication for their patient. The pharmacopeias are published by a government or a major medical or pharmaceutical association. The first pharmacopoeia seems to have been the Antidotarium Florentinum which was published by the College of Medicine in Florence, Italy, in 1567. However, a far more detailed work was published in Nuremberg, Germany, in 1542 with Valerius Cordus, a medical student, deciding to include details on the preparation of medicines and printing it for sale to apothecaries in Germany. The work by Valerius Cordus meant that apothecaries no longer needed to rely on early treatises by the Arab writer Avicenna or the Jewish writer Bulchasim Ben Aberazerim, and the work of Cordus was quickly copied for sale in other European countries. In 1618, in an attempt to try to help apothecaries in England, the College of Physicians in London drew up a book which became known as the London Pharmacopoeia, which contained the details on the exact methods of preparations of medicines. A new edition was published in 1621, with subsequent editions in 1639 and 1677. However, it was not until 1721 that Sir Hans Sloane managed to make important alterations, publishing a heavily revised edition in 1788. This excluded medical practices, which experience had proven to be useless. In spite of the Napoleonic Wars, in 1809 the new edition of the pharmacopoeia adopted French chemical nomenclature, and in 1815, following the end of the wars, a revised edition was published. New editions were issued in 1824, 1836, and 1851. By this time, many people were beginning to go to Scotland for medical
1372 Pharmacy training and the Edinburgh Pharmacopoeia, published between 1699 and 1841, was also popular, as was the Dublin Pharmacopoeia, published from 1807 until 1850, for those training in Ireland. All these works— from London, Edinburgh, and Dublin—were all translated into Latin, ensuring that all doctors needed a very good working knowledge of Latin. The Medical Act of 1858, passed by the British Parliament, led to the publication of the British Pharmacopoeia. The aim was to encompass the scholarship previously included in the London Pharmacopoeia, the Edinburgh Pharmacopoeia, and the Dublin Pharmacopoeia, as well as translating all the work into English for the first time. The British Pharmacopoeia was first published in 1864 and became so popular that a new edition, with some important revisions, was published three years later. Since the fourth edition in 1898, a committee of the Royal Pharmaceutical Society of Great Britain has been appointed at the request of the General Medical Council to advise on items to be included and the manner of their inclusion. The Pharmacopoeia has been revised regularly since then, becoming well recognized throughout the English-speaking world. In the United States, there is a United States Pharmacopoeia, which is sanctioned by the U.S. government. Some other countries such as Japan have their own pharmacopoeia, and there is now a European Union Pharmacopoeia. Many countries that are unable to produce their own, have adopted one used by another country. In 1951, the World Health Organization tried to establish the Pharmacopoea Internationalis which would serve as an “International Pharmacopoeia,” aimed at eliminating or minimizing differences between other national pharmacopoeias. However, these plans were abandoned, although new ones have recently emerged to try to achieve some of the objectives planned for in 1951. SEE ALSO: Pharmacist; Pharmacologist; Pharmacology;
Pharmacy.
Bibliography. Lee Anderson and Gregory J. Higby, The
Spirit of Voluntarism: A Legacy of Commitment and Contribution: The United States Pharmacopeia 1820–1995 (United States Pharmacopeial Convention, 1995).
Justin Corfield Geelong Grammar School, Australia
Pharmacy As a field of study, pharmacy is a chemical science concerned with the preparation and dispensing of medications; and a pharmacy, sometimes referred to as a drugstore or apothecary in the community setting, is the physical structure in which most pharmacists practice the profession of pharmacy. Pharmacy as a Science and Profession The study of pharmacy, symbolically represented with a mortar and pestle or with the letters “Rx”, includes training in several key disciplines, such as anatomy, physiology, biochemistry, pharmacology, medicinal chemistry, pharmacy practice, pharmaceutics, pharmacy law, pharmacokinetics, and medication compounding. Within the practice of pharmacy, numerous specialties exist, which vary depending on the practice setting. Individuals with training in pharmacy may work as community pharmacists in retail or neighborhood pharmacies, as clinical pharmacists or hospital pharmacists in hospitals or in hospital pharmacies, as consultants, as drug information specialists, as professors and researchers in academia, or as specialists in the pharmaceutical industry. Other specializations based on clinical roles may include nuclear, oncology, cardiovascular, infections disease, diabetes, nutrition, geriatric, and psychiatric pharmacy. In addition, many pharmacy schools are reforming curricula to increase emphasis in fields such as pharmacotherapeutics, clinical pharmacy, nuclear pharmacy, disease state management, pharmacoeconomics, pharmacoepidemiology, and pharmacogenomics, thereby expanding the scope of traditional pharmacy training and practice. Pharmacy as a Practice Setting A community pharmacy, sometimes called a drugstore or an apothecary, often consists of a retail storefront with a separate area in which medications are stored and dispensed. The dispensary is subject to regulation with requirements specified in legislation for things such as storage conditions, compulsory texts, and equipment. Community pharmacies often employ licensed pharmacists as well as trained pharmacy technicians. In recent years, different types of retailers have begun establishing pharmacies in developed countries, including grocery stores and mass merchandisers.
Phenotype
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BIBLIOGRAPHY. Judith E. Thompson and Lawrence Davi-
dow, A Practical Guide to Contemporary Pharmacy Practice (Lippincott Williams & Wilkins, 2003); University of the Sciences in Philadelphia, Remington: The Science and Practice of Pharmacy (Lippincott Williams & Wilkins, 2005); Fred B. Gable, Opportunities in Pharmacy Careers (McGraw-Hill, 2003). Joshua J. Gagne, PharmD Jefferson Medical College
Phenotype Within the practice of pharmacy, numerous specialties exist, which vary depending on the practice setting.
Hospital pharmacies are usually found within the premises of the hospital. Hospital pharmacies usually stock a larger range of medications, including more specialized medications, than community pharmacies. Hospital pharmacists and trained pharmacy technicians compound sterile products for inpatients including total parenteral nutrition, and other medications given intravenously. This is a complex process that requires adequate training of personnel, quality assurance of products, and adequate facilities. In addition to community and hospital pharmacies, the beginning of the twenty-first century has witnessed the spawning of new types of pharmacies, namely mail-order pharmacies and internet pharmacies. Mail-order pharmacies typically consist of a central dispensary equipped to handle large volumes of prescription orders, which accepts prescriptions from health providers and the dispensed medications to patients without any face-to-face interaction. Internet pharmacies operate in a similar fashion but have come under considerable scrutiny from various regulatory agencies. Concerns over international importation, counterfeiting, and proper licensing have made internet pharmacies a contentious issue. SEE ALSO: American Pharmaceutical Association (APhA);
Pharmacist; Pharmacology.
The term phenotype was coined by the Danish botanist and geneticist Wilhelm Ludvig Johannsen and is used to describe an individual organism either through its total physical appearance and/or constitution, or a specific manifestation of a particular trait such as the size, eye color, or variations in behavior. The concept developed by Johannsen, now accepted by medical researchers around the world, was that individual organisms had a “genotype” made up from their DNA which is inherited from their parents. Although Johannsen worked initially on plants, much research has been conducted on animals, and most of the work has been on human beings. Obviously, phenotypes are determined, to a large extent, by the genotype of the person, but environmental and behavioral factors can also be important and these can result in phenotypes whereby people look, act, or feel different to their parents. There may also be random variations, and this has meant that the relationship can essentially be summarized as a person’s phenotype is made up from his or her genotype (inherited characteristics), his or her environment and behavior, and some element of random variations. As a result, people who suffer from cancer may do so as a result of a genetic predisposition, from their environment (such as exposure to radiation), their behavior (such as smoking), and also random factors. SEE ALSO: Genetics; Genotype. Bibliography. J. Cummings, Genotype-ProteotypePhenotype Relationships in Neurodegenerative Diseases (Springer, 2005); Richard Dawkins, The Extended Phenotype: The Long Reach of the Gene (Oxford University Press,
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Phenylketonuria
1989); Steve E. Humphris and Sue Malcolm, From Genotype to Phenotype (Bios Scientific Publishers, 1994). Justin Corfield Geelong Grammar School, Australia
Phenylketonuria Phenylketonuria (PKU) is an inherited genetic disorder that increases blood levels of the essential amino acid phenylalanine (a building block of protein). It is normally obtained through the diet in regulated levels. If PKU is not treated, excess phenylalanine can build up to harmful levels in the body a few months or even weeks after birth, causing mental retardation and eventual death. Genetic Disorder PKU is considered the most severe manifestation of hyperphenylalaninemia (too much phenylalanine in the body) and is inherited as an autosomal recessive trait due to phenylalanine 4-monooxygenase deficiency. Autosomal recessive traits refer to genetic conditions that occur only when mutations are present in both copies of a given gene. Commonly, the parents of an individual with an autosomal recessive disorder are carriers of one copy of the altered gene but do not show signs and symptoms of the disorder. PKU allows the accumulation of excess phenylalanine and related components and disables the excretion of phenylalanine, phenylpyruvic acid, and other related compounds. In the developing world and regions where access to medical care, diagnosis, and adequate treatment are nonexistent, PKU can be deadly. However, if diagnosed early in the disease and early restriction of dietary phenylalanine is initiated, symptoms of the disease can be significantly reduced and prognosis is favorable. Types of PKU The signs and symptoms of PKU vary from mild to severe. The most common sign is a musty or mouse-like odor to the skin, hair, and urine from excess phenylalanine. Most common characteristics of severe form PKU are mental retardation, hypopigmentation of hair and skin, tumors, seizures, and eczema. Less severe forms of PKU (sometimes called moderate or mild
PKU) have a smaller risk of brain damage. People with very mild cases may not require a therapeutic diet. Also, women with PKU and uncontrolled phenylalanine levels have an increased risk of pregnancy loss altogether. This is significant in poorer countries where mothers may have mild forms of PKU or are currently under poor and intermittent treatment for PKU and do not have adequate access to prenatal care. The most severe form of this disorder is known as classic PKU. Infants with classic PKU appear normal until they are a few months old and quickly develop symptoms. Without treatment of a special low-phenylalanine diet, these children develop permanent mental retardation and behavioral problems and can die. Other symptoms in more severe cases of PKU can involve seizures, extreme mental and physical development, vomiting and diarrhea with weight loss, photosensitivity, and abnormal movement disorders. Epidemiology Newborn screening and prompt treatment ensure the best outcome. As a result, the severe signs and symptoms of classic PKU are rarely seen where there is adequate resource and access to medical care, as in much of North America. In poorer parts of the world, most born with PKU may not make it past adolescence. The occurrence of PKU varies among ethnic groups and geographic regions worldwide. In the United States, PKU is detected in 1 in 10,000 to 15,000 newborns. Throughout the world, Turkey reportedly has the highest incidence with approximately 1 in 2,600 births. High incidence is also reported in the Yemenite Jewish population, as well as in regions of northern and eastern Europe, Italy, and China. There is no sex determination for PKU. Genes Related to PKU More specifically, mutations in the PAH gene cause phenylketonuria. The PAH gene produces an enzyme called phenylalanine hydroxylase. This converts the amino acid phenylalanine to other essential compounds in the body. Normal levels of this amino acid are important for brain function. In PKU, gene mutations reduce the activity of phenylalanine hydroxylase. Phenylalanine from the diet accumulate to toxic levels. This buildup of phenylalanine then causes the signs and symptoms discussed thus far.
Pheochromocytoma
Prognosis Prognosis for normal intelligence is excellent with dietary treatment and prompt diagnosis and adequate resources. In regions of the world where infant testing and early diagnosis are nonexistent, prognosis is quite poor. The decreased health resources and inadequate access to medical personnel help in making PKU treacherous in the developing world. SEE ALSO: Ecogenetics; Genetic Disorders; Metabolic
Disorders.
Bibliography. Jean Koch, Robert Guthrie—The PKU
Story: Crusade against Mental Retardation (Hope House, 1997); PM Medical Health News, 21st Century Complete Medical Guide to Phenylketonuria (PKU), Authoritative Government Documents, Clinical References, and Practical Information for Patients and Physicians (CD-ROM) (Progressive Management, 2004). John Michael Quinn V, M.P.H. University of Illinois at Chicago
Pheochromocytoma Pheochromocytoma is a catecholamine-secreting tumor derived from the chromaffin cells of the adrenal medulla. The term pheochromocytoma refers to the appearance of the tumor cells on histological section after staining with chromium salts (phios means darkcolored, chromo means color, cytoma means tumor). Approximately 90 percent of pheochromocytomas reside entirely within the adrenal glands. The remainder may develop external to the gland in the paraganglion chromaffin tissue of the sympathetic nervous system. In such instances the tumors are referred to as an extra-adrenal pheochromocytoma or, paraganglioma. Pheochromocytomas secrete the catecholamines epinephrine (adrenaline) and norepinephrine (noradrenaline) and elevated plasma dopamine levels have been reported in some cases. Despite the fact that healthy adrenal chromaffin cells predominately secrete epinephrine, pheochromocytomas secrete norepinephrine in greater abundance. One exception is in the case of familial pheochromocytomas which tend to secrete more epinephrine. Nonetheless, ex-
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cessive unregulated catecholamine secretion results in hyperstimulation of both α and β adrenergic receptors. This leads to sporadic episodes of life-threatening hypertension, increases in cardiac contractility, cardiac arrhythmias, glycogenolysis, gluconeogenesis, and intestinal relaxation. Pheochromocytoma is considered a rare disease. The prevalence of pheochromocytoma is estimated at 1 in 100,000 persons per year, and about 0.1 percent in patients with hypertension and 4 percent in patients with adrenal mass. Approximately 25 percent of these masses are discovered incidentally before symptoms arise. Incidence of pheochromocytoma is found equally in males and females, and is not specific to any ethnicity. It may occur in individuals of any age, although the peak incidence is between the third and fifth decade. Patients with pheochromocytoma present with a history of episodic headaches, palpitations, and perfuse sweating, all associated with severe high blood pressure. Other symptoms may include feelings of anxiety or terror, tremor, nausea, and constipation is common. Pheochromocytoma is associated with several familial endocrine disorders characterized by multiple and varied tumors throughout a variety of endocrine, and neuroendocrine tissues. For example, pheochromocytoma is a constituent of the multiple endocrine neoplasia type IIa (MEN IIa), and type IIb (MEN IIb) syndromes. These conditions are almost invariably (95 percent) associated with genetic mutations in a gene—more specifically a proto-oncogene—named ret. The ret proto-oncogene encodes for a cell-surface protein called a tyrosine kinase. Abnormal tyrosine kinase activity may cause dysfunctional regulation of the cell life-cycle, and is known to contribute to a variety of cancerous conditions. In addition, there is evidence that pheochromocytoma is associated with the syndromes neurofibromatosis (von Recklinghausen disease), and von Hippel-Lindau (VHL) disease. The physical findings of patients with pheochromocytoma are consistent with the known actions of catecholamines. These include, but are not limited to hypertension, hypertensive retinopathy, orthostatic hypotension, pallor, tremor, and abnormal cardiac rhythms. Other physical findings may include café au lait spots and neurofibromas. The symptoms are associated with surges of catecholamine secretion from the tumor that occur in spells of inconsistent timing and duration. It is not clear-
1376 Philippines ly understood what mediates episodic catecholamine secretion, but some triggers include mechanical stimulation arising from intra-abdominal pressure during urination or defecation, childbirth, emotional distress, administration of anesthesia, and several classes of drugs that affect the autonomic nervous system. Circulating catecholamines are metabolized to the inactive compounds metanephrine and normetanephrine. High concentrations of these metabolites in blood or urine indicate the presence of a catecholamine-secreting tumor. Once pheochromocytoma is diagnosed via laboratory studies, imaging studies may be carried out. Early diagnosis of pheochromocytoma is crucial to the prognosis of the patient. If the tumor is diagnosed early, surgical excision and resection can cure the symptoms. For a description of the pre-and postoperative patient management of the surgical resection of the tumor see Florence Grant’s article entitled: “Anesthetic considerations in the multiple endocrine neoplasia syndromes” (2006). See Also: Endocrine Diseases (General); Endocrinology. Bibliography. Kudva YC, Sawka AM, Young WF Jr.,
“Clinical review 164: The Laboratory Diagnosis of Adrenal Pheochromocytoma: the Mayo Clinic experience,” Journal of Clinical Endocrinology and Metabolism (October 2003); Mantero et al., “A Survey on Adrenal Incidentaloma in Italy. Study Group on Adrenal Tumors of the Italian Society of Endocrinology,” The Journal of Clinical Endocrinology and Metabolism (2000); Neumann HP, Berger DP, Sigmund G, et al., “Pheochromocytomas, Multiple Endocrine Neoplasia Type 2, and von Hippel-Lindau disease.” The New England Journal of Medicine (November 18, 1993); Plouin and GimenezRoqueplo, “Pheochromocytomas and Secreting Paragangliomas,” www.orpha.net. (cited March 2005). Phillip C. Usera The Medical School for International Health Ben Gurion University, Israel
Philippines The Republic of the Philippines covers 7,107 islands and is located off the east coast of southeast Asia. It was occupied by the Spanish from 1565 who gradually
expanded their rule over the whole archipelago. However they lost the Philippines in a war with the United States in 1898. During World War II, the Japanese occupied the Philippines, with the country gaining its independence in 1944. The Republic of the Philippines now has a population of 85,237,000 (2005), with 123 doctors and 418 nurses per 100,000 people. During the Spanish colonial period, hospital services were largely restricted to the treatment of Europeans, wealthy Chinese and members of the local elites, with a combination of European and Chinese practices used. In the 1890s when the Philippines was trying to achieve independence from the Spanish, the great hero of the nationalist movement was José Rizal (1861-1896) who was, by training, a physician. On September 29, 1898, the new U.S. administration in the country established a Board of Health with Dr. Frank S. Bourns as its first president. Its initial aim was to treat the U.S. soldiers who had been injured in the fighting, but at the end of the war, in was changed into a civilian organization, with Dr. L.M. Maus appointed as the first health commissioner. Soon after the start of U.S. rule, the country was devastated by an epidemic and as a result the Americans established a large medical infrastructure, with the Manila Medical Society founded in 1902, the Philippine Medical Association being established in 1903, and the University of the Philippines College of Medicine and Surgery opening in 1905. Four years later formal classes for nurses were held at the Philippine Normal School, with the Bureau of Health reorganized in 1915 and renamed the Philippine Health Service. With limited self-rule introduced in 1916, on January 1, 1919 the first Filipino to be in charge of the Philippines health service was Dr. Vicente de Jesus; and in the following year the Philippine Pharmaceutical Association was founded and incorporated. In 1923 some 76 percent of all deaths in the country were still being caused by communicable diseases. In 1933 the health service was reorganized and became the Bureau of Health, and started publishing its official journal, The Health Messenger. The first chief of the Bureau, after the inauguration of the Commonwealth of the Philippines in 1935, was Dr. Jose Fabella. By this time there were 38 hospitals and 1,535 dispensaries in the Philippines, focusing on the treatment of malnutrition, malaria, tuberculosis, leprosy, and gastrointestinal disease. During World War II, the coun-
Phrenology
try was occupied by the Japanese, and the provision of healthcare declined considerably. Claro M. Recto was appointed Commissioner working in the newly-created Department of Education, Health and Public Welfare. After the war, there were attempts to rebuild the health services in the country, with the Department of Health created in 1947 by President Manuel Roxas, along with the Philippine Paediatric Society being founded in the same year. In the following year the Institute of Nutrition was established, and in 1958, President Elpidio Quirino instituted a wholesale reorganization of the Department of Health. Services were increased in the first years of the Ferdinand Marcos presidency, in the late 1960s – Marcos’s brother, Pacifico Edralin Marcos being the president of the Philippine Medical Association and becoming nicknamed “Mr. Medicare” for his work at trying to get universal free healthcare, although he later distanced himself from his brother’s policies. In 1978 the Department of Health became the Ministry of Health with Dr. Clemente S. Gatmaitan becoming the first Minister of Health. By 1980 only 26 percent of deaths in the country came from communicable diseases. However dissatisfaction with the Marcos presidency during the 1970s, and by the introduction of martial law, did see large numbers of professionals, including many Filipino doctors, migrate to the United States. However training programs increased and by 1989 the ratio of doctors to the population was similar to many other SouthEast Asian countries The medical problems facing the country still include malaria and tuberculosis, to which was added H.I.V./A.I.D.S., which has affected many people since the 1990s. Malaria remains particularly prevalent in some parts of the country, notably Palawan and Mindanao, with dysentery and cholera also affecting significant numbers of people. SEE ALSO: Healthcare, Asia and Oceania. Bibliography. Eduardo R. de la Cruz, History of Philip-
pine Medicine and the PMA (Philippine Medical Association, 1984); Robert B. Stauffer, The development of an interest group: the Philippine Medical Association (University of the Philippines Press, 1966); Justin Corfield Geelong Grammar School, Australia
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Phrenology Phrenology, coming from the Greek terms for “mind” and “knowledge,” is a study that claimed it was possible to determine character, personality traits, and criminality based on the shape of a person’s head. The concept of being able to read somebody’s head started with the Greek philosopher Aristotle. However, the idea was first developed as a scientific idea by the German anatomist Franz Joseph Gall who originally developed a concept of “canioscopy,” which involves a study of the skull, or cranium, as it was called in Latin. Gall became “the founding father of phrenology” and his works became criticized by the Roman Catholic Church who argued that Gall’s concepts were contrary to religious teachings. When Gall’s work was rejected by the Austrian court, he moved to Germany where he met with Joseph Caspar Spurzheim and collaborated with him before moving to France in 1807. There, he started writing on phrenology, his ideas becoming popular in the United States and Britain, with Spurzheim disseminating the idea in the latter country. Phrenology in Britain was developed by two Scottish brothers, George Combe and Andrew Combe— the former being the author The Constitution of Man, or Elements of Phrenology (1838). Soon afterward, two American brothers, Lorenzo Niles Fowler and Orson Squire Fowler, started to run a phrenological firm, designing the “phrenology head”—a china head with different sections of the brain marked. Although Franz Joseph Gall used phrenology to draw some conclusions about race in Victorian Britain, there was great interest in the possibility of using the shape of the head to study the likelihood of criminality. As a result, it was common for the heads of executed criminals to be examined to see whether there were “bumps” or other signs common to the heads of other criminals. For instance, in the Australian state of Victoria, after criminals were hanged, their heads were cut off and the hair shaved from them, with plaster casts being made of their heads which were then used by phrenologists. Although this was an accepted practice at the time, there was consternation when this happened to the executed bushranger Ned Kelly in 1880, mainly because he had a large public following. Interest in phrenology remained high during the Victorian and Edwardian periods, with the British psychiatrist Bernard Hollander writing a number of
1378 Phylogenetics bestselling books including The Mental Function of the Brain (1901) and Scientific Phrenology (1902). Even the prominent politician, who later became prime minister, David Lloyd George, openly expressed his interest in phrenology, wanting to meet with C. P. Snow so that he could study the shape of the author’s head. However, phrenology as a discipline was excluded by the British Association for the Advancement of Science and other groups and is now discredited as a pseudoscience. The Belgian Roman Catholic priest Paul Bouts tried to restart interest in phrenology, which had become popular during the Nazi period in German as a way of finding a “scientific” basis for racial superiority. The whole concept of phrenology has now been largely debunked. SEE ALSO: Mental Health; Neurology. Bibliography. Charles A. Blöde, Phrenology Examined, vol. 2 of The Emergence of Neuroscience in the Nineteenth Century (Routledge/Thoemmes Press, 2000); Roger Cooter, Phrenology in the British Isles: An Annotated Historical Bibliography and Index (Scarecrow, 1989); John van Wyhe, Phrenology and the Origins of Victorian Scientific Naturalism (Ashgate, 2004).
Justin Corfield Geelong Grammar School, Australia
Phylogenetics Phylogenetics is the study of the ancestral relatedness of groups of organisms, whether alive or extinct. History Classification of the natural world into meaningful and useful categories has been a basic human impulse, and is systematically evident at least since time of ancient Greece. Dominant for close to 2,000 years in the West was the notion of a “great chain of being” or scala natura, which emphasized a static notion of reality and depicted a hierarchy or ascending ladder starting from matter and nature (such as rocks) and moving upward to humans, angels, and eventually and highest of all, God. Since Linnaeus, and especially since Darwin, classificatory schemes have not only quickly
put aside such notions as the scala natura, but have also slowly moved away from postulating relationships between species based on either presumed essential traits or based on overall similarity. The field of phylogenetics takes a functional and more scientific turn in its attempts to construct an ever-more objective depiction of ancestral and evolutionary relationships between organisms based on derived similarities found via the integration of genetic, molecular, archaeological and historical studies and with the specific purpose of explaining, predicting, and testing similarities and differences between organisms, and specifically between groups of organisms or species. The Tree of Life Ancestral relationships among species are commonly represented as phylogenetic trees (also called cladograms or dendrograms). A cladogram is most significantly a physical representation of a hypothesis of inferred relationship between species. The evolutionary relatedness between species is reflected by branching pattern of the tree, and specifically, the represented distance between species on the tree. Any two species will have a common ancestor at the point where their respective branches are traced back to intersect. The more recent a common ancestor to humans, the more likely it is more related to humans. For example, the common ancestor of modern humans and (now extinct) Neanderthals would be traced back to approximately 500,000 years ago. Similarly, the common ancestor of humans/Neanderthals and chimpanzees existed approximately 6.5 million years ago. Thus, since humans and Neanderthals share a common ancestor not shared by chimpanzees, we have reason to believe that humans are more closely related to Neanderthals than to chimpanzees. Similar retracing can be done farther and farther back on the branches of the tree of life to connect the common ancestry humans have with unicellular species some billions of years ago. Estimating Relatedness Cladograms can be constructed with the aid of technologies that estimate molecular divergences in key sequences of DNA or protein amino acids. Similar to the progress seen in estimating the age of organic substances with the use of radioactive decay technologies and carbon dating, the advent of
Physical Therapy
molecular biological technologies in the later half of the 20th century have increasingly allowed scientists to accurately estimate the degree of evolutionary relatedness at the genetic level. Taking two homologous DNA sequences in different species, one can estimate evolutionary distance by measuring the number of nucleotide substitutions that have occurred over time. Alternatively, using protein products of DNA expression, one can measure the number of amino acid substitutions that have occurred between homologous protein sequences. A number of statistical and computational methods have been developed to account for biases in point mutation substitution rates in target DNA or protein sequences, for example, that transitions (nucleotide substitutions between purines [A/G] or between pyrimidines [C/T]) occur at greater rates than transversions (substitutions between purines and pyrimidines). Due to their use of such statistical and organizational methods as parsimony, Bayesian inference, and maximum likelihood estimation (MLE), the principles used in phylogenetic classificatory schemes are able to be applied to other fields of knowledge (e.g., linguistics) where one desires to organize information with common descent and subsequent modification over time. SEE ALSO: Darwin, Charles; DNA; Gene Pool. Bibliography. Willi Hennig, Phylogenetic Systematics
(University of Illinois Press, 1966); M. Kimura, “A Simple Method for Estimating Evolutionary Rates of Base Substitutions through Comparative Studies of Nucleotide Sequences,” Journal of Molecular Evolution (v.16, 1980). Omar Sultan Haque Harvard University
Physiatry The term physiatry, from the words physikos (physical) and iatreias (healing), is a medical specialty more commonly known as physical medicine and rehabilitation. The focus of physiatric practice is to restore individuals to a state of optimal physical, psychological, and social functioning from limitations that may
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have resulted from congenital or acquired disorders. Physical medicine and rehabilitation specialists may deal with any organ system, but most often treat musculoskeletal and neurological dysfunction. They may also focus on pain management and cardiopulmonary issues, and may specialize in geriatric or pediatric populations. The physiatric assessment involves evaluation of functional status and mobility, as well as determination of the patient’s ability to perform activities of daily living (ADLs) and independent activities of daily living (IADLs). Electromyography, a method of measuring electrical currents in resting and contracting muscles, is an important diagnostic method in the practice of physiatry. The practice of physiatry necessarily involves an interdisciplinary team including physical and occupational therapists, in practice settings that include acute inpatient rehabilitation, extended care, and home rehabilitation. Physiatrists usually discourage inactive convalescence and encourage early ambulation, aggressive physical therapy, and progressive increased intensity of activity. Physiatrists also recognize that psychological, emotional, and social support are critical to complete recovery and optimal functioning. The field of physical medicine grew out of medical and rehabilitation needs recognized after World War I and gradually developed until physiatry was recognized as a specialty in 1947. Physiatrists are certified by the American Board of Physical and Rehabilitation Medicine. There are approximately 5,000 board-certified physiatrists in the United States. SEE ALSO: Physical Therapist; Physical Therapy. Bibliography. R. L. Braddom and R. M. Buschbacher, Physi-
cal Medicine and Rehabilitation, 3rd ed. (Saunders, 2005).
Barry Pakes, M.D., M.P.H. University of Toronto
Physical Therapy Physical Therapy (PT) is a field that helps patients recover from, and adapt to, disease and injury. Patients seen by physical therapists suffer from not only
1380 Physiology to Physical Therapy (Mosby, 2006); R. Sheon and A. Duncombe, “Rehabilitation Program for the Low Back,” www. uptodate.com (cited October 2006). Gautam J. Desai, D.O. Megan C. Urquhart, MSII Kansas City University of Medicine and Biosciences College of Osteopathic Medicine
Physiology
A physical therapist can be certified as a specialist if they obtain 2000 hours of clinical practice within the area of interest.
musculoskeletal conditions such as low-back pain, but also neurological conditions such as cerebral palsy. Therapists may use a variety of techniques, including range of motion exercises, ultrasound, heat and cold applications, TENS (transcutaneous electrical nerve stimulation) units, and traction. PT may be performed in a hospital, clinic, or patient’s home. Therapists make objective measurements of progress, and send reports to the referring provider. For example, at the beginning of therapy, a patient may have rated his pain at a 6 on a 1 – 10 scale, and at the end of a 4-week session, may report his pain is now a 2/10. Most physical therapists have either a Masters or Doctoral in physical therapy. Masters programs usually require two years of post-graduate training. A physical therapist can be certified as a specialist if they obtain 2000 hours of clinical practice within the area of interest. Many areas of expertise exist, including aquatic therapy, cardiovascular/pulmonary, pediatrics, sports, and geriatrics. SEE ALSO: Activities of Daily Living (ADLs); Back Injuries;
Occupational Injuries; Rehabilitation.
Bibliography. Terry Boles, et al., The American Physical
Therapy Association Book of Body Maintenance and Repair (Tandem Library 1999); Michael Pagliarulo, Introduction
Physiology literally means the study of nature. This broad topic spans the study of plants, animals, and humans. More specifically, physiology is concerned with how things function. This study of function can be on a molecular level or a gross level. Even though there are obvious differences between plant, animal, and human physiology, at a microscopic level, there are similarities. Often, one type of physiology can be used to better understand another. Plant physiology has a number of unique aspects and important characteristics to apply in the field of agriculture. Some features unique to plants help us understand our environment. For example, we know the process of photosynthesis is how plants convert energy from sunlight, water, and carbon dioxide (the part of air we breathe out) into food. This process then produces oxygen, which is the air we breathe. By understanding this link, we can better appreciate the importance of our environment to our own health. Moreover, understanding the function of plants is applicable to agriculture. In understanding how plants function, we can look for ways to alter the growth of plants in beneficial ways. Scientists have developed ways to increase crop resistance to disease and insects in order to increase crop yields. Another area of physiology is animal physiology. This classification can include microorganisms as well as animals. The basic study of the function of microorganisms is termed microbial physiology. Microorganism physiology has additional subdivisions. For instance, some people study how microorganisms function as a group. Usually, this categorization of microorganisms is referred to as a community or biofilm. Therefore, this specialty is referred to as biofilm physiology.
The specific study of the microorganisms called bacteria is bacterial physiology. Other areas focus on how microorganisms function while interacting with other organisms. An example of this is microbe–host interactions and bacteria–host interactions. Each of these areas study how microorganisms interact with higher organisms such as humans. The term animal physiology often refers to the study of how an animal’s body functions. This research has several aspects. First, some people study how an animal’s body operates, simply to gain a better understanding. In contrast, others study animal physiology to better grasp how everything is interconnected within our environment. In many instances, studies of how an animal’s body functions are carried out for other reasons. Sometimes, we are using it to better understand our own physiology. Sometimes, researchers desire to determine how something can be improved as a food source. It is essential when animals are utilized as a food source that their immune system functioning be understood. In the event an animal becomes ill, a determination can be made as to what the results of the infection or disease will be. With this, effective treatments can be established. This is crucial to prevent contamination of the food supply. Many research studies are conducted utilizing animals. Various animal physiology studies have helped medical progress. These inquiries have resulted in effective treatments for various diseases, such as rabies, anthrax, small pox, tetanus, and measles. Furthermore, animal physiology research has helped improve medical techniques. In the 1920s the use of animals helped in discovering the hormone insulin and its function in the body, particularly, as it relates to diabetes mellitus. This discovery has helped save countless people. Other medical research advances in the 20th century have been based upon the similarities animal physiology and human physiology. These outcomes have helped to develop the technique of cardiac catheterization, open heart surgery (i.e., heart transplantation, coronary artery bypass grafts), and cardiac pacemaker implantation. Appreciating and understanding the similarities between the physiology of animals and ourselves has led to numerous lifesaving advances in medicine. The aforementioned specialties have an appreciation for the similarities between human and animal
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physiology, but another looks at differences. The area of comparative physiology does just as the name implies; it compares and contrasts the functional systems of all animals and humans and notes the similarities and differences. Like other segments of physiology, human physiology can be further subdivided into various specialties. Some specialties within human physiology focus on microscopic components. Cell physiology, for instance, looks at how cells function and interact within the human body. A more focused specialty is endocrinology, which looks at the chemical messengers called hormones. Researchers examine how these messengers work throughout the body. The study to understand how molecules are exchanged and transported across cell membranes is termed membrane physiology. Other areas within human physiology focus on entire body systems. The general study of the functions of the heart and the blood vessels is called cardiovascular physiology. A similar, yet distinct, area of study called cardiology examines how the heart functions normally and in disease states. Immunology pertains to the study of immune cells’ normal function and how they respond to foreign or “non-self ” material. To analyze how muscles operate is to study myophysiology. Research that is concerned with the brain’s specialized cells called neurons, the spinal cord, and the nerves is called neurophysiology. The specialty of neuroendocrinology is concerned with the complex interactions between neurophysiology and endocrinology. To understand how the kidney’s function to control the excretion of ions and metabolites is to look at renal physiology. The study of reproductive behaviors and various aspects of the reproductive cycle (puberty, menstrual cycle, pregnancy, and menopause) are studied in the field of reproductive physiology. The aspect of physiology that unwraps the mysteries of gas exchange at the microscopic and macroscopic levels is the field of respiratory physiology. There are many subdivisions within human physiology and further division of these into explicit areas of specialty. Besides these various areas of specialty in human physiology, there are still numerous topics that examine how the human body adapts to various stimuli. First of all, exercise physiology is a wide area of study analyzing how human physiology adapts to the stress of exercise or physical activity. Depending on where
1382 Pituitary Disorders you perform your physical activity, a related field of study is environmental physiology. This subspecialty focuses on how the body functions within various climactic conditions. Our bodies for instance, adapt differently to desert conditions than to the artic cold or to high-altitude atmospheres. The field that observes how our body’s functioning may change over time is termed evolutionary physiology. Due to the complex nature of our body’s functions, there are so many areas of specialized study within the broad area of human physiology. Human physiology is composed of all of the body systems as specialties as well as other areas of specialty including exercise and environmental physiology. To understand human physiology, we often observe the physiology of animals. Additionally, we study animal physiology for its own unique characteristics as well. Finally, plant physiology is an important study that helps us to understand our food supply. Discovering how these various systems work helps us to better understand nature. SEE ALSO: Biochemistry; Endocrinology; Neuroendocri-
nology.
Bibliography. Bryan H. Derrickson and Gerard J. Tor-
tora. Principles of Anatomy and Physiology, 11th ed. (Wiley, 2005); Stuart Ira Fox, Human Physiology, 9th ed. (McGrawHill, 2006); William F. Ganong, Review of Medical Physiology, 22nd ed. (McGraw-Hill Medical, 2005); Dee Unglaub Silverthorn, Human Physiology: An Integrated Approach, 4th ed. (Benjamin Cummings, 2006). Linda E. May Kansas City University
Pituitary Disorders The pituitary is an essential gland in the body, and diseases affecting it are generally defined by the effect they have on the hormones that the pituitary produces. The pituitary hormones control many of the important functions of the body. Many different pituitary disorders can occur and they interfere with the basic events of life, such as normal growth and reproduction, which necessitates treatment and sup-
port for those affected with these diseases by specialists across many health and social service fields. The pituitary gland is a small, pea-sized gland located underneath the brain and behind the eyes. It is surrounded by a number of important structures, including the optic nerves, the hypothalamic region of the brain, and the internal carotid arteries. It lies in a bony area at the base of the skull (called the sella turcia, or Turkish saddle, due to its appearance). The pituitary gland has two main parts, the anterior part (called the adenohypophysis) and the posterior part (called the neurohypophysis). The adenohypophysis is thought to develop in humans by an outpouching of Rathke’s pouch, which grows up from the mouth of the developing embryo. The neurohypophysis grows down from the developing brain. Both sections of the pituitary interact closely with the brain, and each produces different hormones. The pituitary gland’s function is to secrete hormones that control the other glands of the body. Most of the hormones are produced in the anterior portion. These hormones are important in growth, ovulation, breast milk production, and control of the thyroid and adrenal glands. Most of the disorders of the pituitary result in either too much or not enough of these hormones being produced. Growth hormone is important throughout the body. It controls growth before and during puberty, and aids in controlling metabolism by influencing glucose levels in the blood. Occasionally, growth hormone can be produced in excess, such as in a pituitary tumor. This causes gigantism (large, tall individuals) if it occurs before puberty and acromegaly (enlargement of the limbs, facial features, and internal organs) if it occurs after puberty. It is essential that this condition be treated due to risk of other serious health problems such as diabetes and heart failure. Either medication or surgery may be used. Conversely, too little growth hormone can be produced, or the body can be resistant to it. This condition causes very short stature and delayed puberty, and is treated by giving extra growth hormone. The growth hormone is given as an injection. Previous growth hormone shortages have been rectified by a recombinant growth hormone that can be produced in a laboratory in large amounts. Prolactin is a hormone essential for breast development and production of milk after pregnancy. When too much prolactin is produced, such as in a pituitary tumor
called a prolacinoma or certain medications, women can experience missed periods, inability to get pregnant, and nipple discharge. This can be treated by surgery or medication. If the pituitary is damaged during surgery, it may produce insufficient amounts of prolactin, and a woman may not be able to produce breast milk. Antidiuretic hormone (ADH) comes from the posterior part of the pituitary and controls the body’s ability to regulate the amount of body water. Too much ADH causes a lack of urination, an accumulation of water within the body, and subsequent dilution of contents of the blood, most importantly, sodium. This is known as the syndrome of inappropriate secretion of ADH (SIADH) and can be caused by head trauma, infections, or certain medications. Conversely, too little ADH causes an increase in urination, dehydration, and concentration of the blood contents. This condition is known as diabetes insipidus and is also caused by trauma, surgery, or infections involving the pituitary. Sheehan’s syndrome is a disorder seen after childbirth. While pregnant, a woman’s pituitary increases in size to produce extra prolactin for milk production. If excessive blood is lost during childbirth, the blood supply to the newly enlarged pituitary can be insufficient and cause some of the gland to die. This is generally discovered when the mother cannot breastfeed, but is very rare with modern medical care. Pituitary apoplexy is a disorder cause by either a hemorrhage of blood into the pituitary or a blockage of its blood supply. This causes headache and inability to move the eyes. It is often treated with steroid drugs or surgery. A variety of other diseases that affect the entire body can similarly affect the pituitary. In general, these are treated by treating the underlying disease. Some examples include tuberculosis, syphilis, amyloidosis, and hemochromatosis. Anything that damages the pituitary, including the disorders above, trauma, or other conditions, can cause failure of the pituitary to produce its other hormones. Two of these hormones are responsible for controlling other glands in the body: thyroid-stimulating hormone and adrenocorticotropic hormone. Both of these hormones are essential for normal body function and their lack can be life threatening. Two additional hormones are important in sexual development, menstruation, and ovulation: follicle-stimulat-
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ing hormone and lutenizing hormone. Lack of these can result in failure to go through puberty or inability to have children. SEE ALSO: Endocrine Diseases (General); Growth Disor-
ders; Neuroendocrinology; Pituitary Disorders.
Bibliography. S. S. Nussey and S. A. Whitehead, Endo-
crinology: An Integrated Approach (Taylor & Francis, 2001); Marschall S. Runge and M. Andrew Greganti, Netter’s Internal Medicine (Icon Learning Systems, 2003).
Cara Sedney West Virginia University
Pituitary Tumor The pituitary gland is a small, pea-sized gland located underneath the brain and behind the eyes. It is surrounded by a number of important structures, including the optic nerves, the hypothalamic region of the brain, and the internal carotid arteries. It lies in a bony area at the base of the skull (called the sella turcia, or Turkish saddle, due to its appearance). The pituitary gland has two main parts: the anterior part (called the adenohypophysis) and the posterior part (called the neurohypophysis). The adenohypophysis is thought to develop in humans by an outpouching of Rathke’s pouch, which grows up from the mouth of the developing embryo. The neurohypophysis grows down from the developing brain. Each part makes different hormones. Both sections of the pituitary interact closely with the brain. The pituitary gland’s function is to secrete hormones, which in turn, control the other glands of the body. These hormones are important in growth, ovulation, breast milk production, and control of the thyroid and adrenal glands. A number of different tumors, or cancers, can develop from the pituitary. Some tumors, called adenomas, can cause hormonal imbalances due to producing too much of a particular hormone. They can also cause hormone deficiencies when the tumor invades or compresses the normal pituitary gland tissue. Other types of tumors can cause symptoms from compression of surrounding structures, such as progres-
1384 Placebo sive blindness from compressing the optic nerves. Headache is also a symptom in some cases. Pituitary adenomas are tumors made up of hormoneproducing cells in the pituitary. Some do still produce hormones, while others do not. If less than 1 cm in size, they are called microadenomas; the name macroadenoma is given to those larger than 1 cm. The most common type of hormone-producing adenoma is called a prolactinoma, which secretes the hormone prolactin. Symptoms of this kind of tumor include nipple discharge, missed menstrual cycles, and infertility in women and sexual problems in men. Adenomas can also secrete excess growth hormone, which produces extremely tall individuals (gigantism) if they occur before puberty, and enlargement of the limbs, facial features, and organs (acromegaly) after puberty. Rarely, pituitary tumors can also produce the other hormones. Generally, only one hormone is produced by an adenoma. Some tumors which are non-hormone–producing may be present throughout one’s life and never be found. Many adenomas can be treated by medicines which counteract the excess hormones and stop the symptoms. Prolactinomas can be treated by bromocriptine, while bromocriptine is used for growth hormone-producing adenomas. However, if medicine does not work or if the tumor is causing symptoms due to its size, surgery is considered the best method of treatment. Generally, these tumors are removed by an incision through the nose or under the lip, which leaves minimal or no visible scarring. In certain circumstances, such as very large tumors, surgery has to be done by an incision above the forehead and through the skull. Craniopharyngioma is a type of tumor thought to grow from remaining cells of Rathke’s pouch. These tumors are seen in either adults or children, and are generally considered to be nonmalignant and slow growing. However, they can become quite large and affect nearby parts of the brain. They can cause blindness or hormone deficiencies from compressing the normal pituitary, and may also cause headaches, personality changes, memory loss, or blockage of fluid around the brain (hydrocephalus). They are made up of calcified material and cysts, which usually contain a dark, thick fluid. Craniopharyngiomas are usually treated with surgery. The techniques for surgery are similar to those for adenomas, but these can be combined with radiation therapy or drainage of the cysts to reduce the size
of the tumor. They can be very difficult to remove and can recur after surgery. Other kinds of tumors occasionally occur within the pituitary. Granular cell tumors can be found in the pituitary or other areas of the body, which generally produce no symptoms and are discovered by accident. Some cancers that have spread, or metastasized, throughout the body may also affect the pituitary. When required, these tumors can be treated similarly to other pituitary tumors. Pituitary tumors can have a profound effect on the lives of patients. Growth-hormone–producing adenomas cause very visible symptoms and some affected people have achieved notoriety, or suffered embarrassment and ridicule, from the effects on their appearance. Andre Roussimoff (“Andre the Giant”) is one well-known example of the effects of a growthhormone–producing adenoma. Prolactin-producing adenomas can keep a woman from achieving a much-desired pregnancy. Craniopharyngiomas can cause long-term difficulty in the lives of patients because of their propensity to recur. Medical researchers have made strides in the medical and surgical treatment of pituitary tumors, although more progress must be made. Recently, “interdisciplinary clinics” have become popular, allowing patients to see many different specialists, such as endocrinologists, neurosurgeons, social workers, and psychologists with a single appointment. SEE ALSO: Cancer (General); Endocrine Diseases (Gen-
eral); Growth Disorders; Neuroendocrinology; Pituitary Disorders. Bibliography. S. S. Nussey and S. A. Whitehead, Endo-
crinology: An Integrated Approach (Taylor & Francis, 2001); Youman’s Neurological Surgery, 4th ed. (Saunders, 1996).
Cara Sedney West Virginia University
Placebo The term placebo appears in a 1785 New Medical Dictionary (2nd edition). Derived from Latin meaning “I will please” or “satisfy,” placebos and the placebo ef-
Pneumonia
fect are evolving concepts. A placebo has alternatively been defined as an empathetic intervention, a treatment, and an ostensibly inert substance. In ancient Babylonia, Assyria, India, Greece, China and Rome, treatments like drugs, magic, religious rituals, prayer and physical therapy are now understood by some researchers as placebos. Some Western medical historians even attribute the efficaciousness of all earlier medical treatments to the placebo effect. Different definitions of placebo and the placebo effect reflect competing philosophies of science and medicine. By the 1930s, placebo controls evolved from interventions in single-blind studies to double-blind clinical trials. In these studies, a placebo is said to depend on the receptivity or suggestibility of the ill person and on the interpersonal skills of the healer. If causal explanations are valued, the placebo effect has been described as an unexpected outcome. If the placebo effect is a direct or indirect therapeutic outcome of a biomedical procedure, some exclude it from further consideration on the grounds that it is an impurity. Other authorities contend that studies of the placebo effect before the mid-1990s were unsystematic and, therefore, that generalizations from them need be regarded with caution. In an emerging trend, some researchers contend that no substance is truly inert. Accordingly, clarity about the context for the placebo effect enhances understanding of the effectiveness of holistic medicine, mind-body self-healing, and cognate traditions like acupuncture and qigong that unblock and redirect a patient’s energy. If medical investigators believe that an experimental treatment is beneficial, then the use of placebos in double-blind studies may not always contribute to the well-being of patients in the control group. Yet eliciting informed consent from human subjects in clinical probably exposes them to favorable influences. In this respect, evidence-based medicine remains at a quandary. See Also: Acupuncture; Doubled-Blinded Study. BIBLIOGRAPHY. Howard Brody, Placebos and the Philoso-
phy of Medicine: Clinical, Conceptual, and Ethical Issues (University of Chicago Press, 1980); Arthur K. Shapiro and Elaine Shapiro, The Powerful Placebo: From Ancient Priest to Modern Physician (Johns Hopkins University Press, 1997); W. Grant Thomson, The Placebo Effect and Health:
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Combining Science and Compassionate Care (Prometheus Books, 2005). Vincent Kelly Pollard University of Hawaii at Manoa
Pneumonia The lungs are primarily responsible for gas exchange, removing carbon dioxide in exchange for oxygen. The lungs have significant surface area and risk coming into contact with a large number of pathogens that can cause infection. To appreciate the consequences of a lung infection, or pneumonia, it is important to understand the normal function of the lungs, the different organisms that can cause infections, and mechanisms that the body uses to prevent infections, the symptoms of pneumonia, the diagnosis, and treatment. Respiratory Physiology The respiratory system is composed of the lungs (each lung has several lobes), which exchange gas, the chest wall, and the respiratory muscles that ventilate or pump air in and out of the lungs. Air initially enters the respiratory system from the nasal passages and pharynx where it can be warmed and humidified. From there, it travels through the windpipe (trachea) into a network of continuously branching hollow passages consisting of bronchi, bronchioles, and ultimately ending in small pouches called alveoli. These alveoli are surrounded by tiny blood vessels (capillaries) that allow for exchange of gases in the blood. The anatomy of the respiratory system contains several mechanisms to decrease the chance of infection. The upper airway consists of a sharp turn from the nose to the pharynx, forcing inhaled particles to become impacted on the mucosa and preventing transport to the trachea. The trachea, bronchi, and terminal brochioles are lined with cells that have small cilia which can move a thin mucous layer which traps pathogens away from the lungs and into the back of the throat to be swallowed or coughed out. In addition, there are antibodies and other antimicrobial proteins secreted by the epithelial cell layer that lines the lower respiratory tract.
1386 Pneumonia Definition Pneumonia results from the infection of the airways of the lung. Pneumonia can be caused by bacteria, viral infections, or fungi. For this to occur, a pathogen must breech the defenses of the airway and establish infection. This can occur after aspiration (inhaling particles of food, liquid, and so forth into the lungs), microaspiration of pathogens found in the mouth and throat, aerosolization of pathogens, or spread through the blood to the lungs. These open areas for air exchange are replaced by growing bacteria, fluid, white blood cells, red blood cells, and debris. This accumulation of materials leads to a decrease in the ability of the lung to expand and contract, decrease in total lung capacity and poor oxygenation leading to hypoxemia. The location of the infection in the lung can be described in several ways. Lobar pneumonia involves an entire lobe of a lung. Bronchopneumonia involves several lobes in a patchwork fashion, with poorly defined borders between infected and noninfected lung tissue. Interstitial pneumonia involves the actual tissue of the lungs and does not significantly affect the hollow airways. Last, military pneumonia consists of diffusely distributed discreet pockets of infection. Pneumonia is more likely to occur in individuals who have an impaired immune system or have underlying disease. Anatomical defects in the airway that prevent removal of pathogens, dysfunction of cilia in the respiratory tract, and deficiencies in components of the immune system all predispose people to pneumonia. Vaccination with the influenza and pneumococcal vaccines can help prevent the development of certain types of pneumonia. Microbiology Pneumonia is often categorized as community-acquired pneumonia or as hospital-acquired (nosocomial) pneumonia, meaning the person caught the infection while in the hospital or long-term care center. This separation is important because the most likely causative organisms for pneumonia are different for the two categories. Community-acquired pneumonia is often caused by Streptococcus pneumoniae, Mycoplasma pneumoniae, and Chlamydia pneumoniae viruses and Haemophilus influenzae, although a wide variety of pathogens can cause pneumonia.
Hospital-acquired pneumonia occurs when a patient develops pneumonia more than 48 hours after admission to a hospital. The risk of development of hospital-acquired pneumonia is increased by admission to medical intensive care units or experiencing mechanical ventilation. This type of pneumonia is often caused by Staphylococcus aureus, Streptococcus pneumoniae, Haemophilus influenzae, Pseudomonas aeruginosa, Acinetobacter species, Enterobacteriaceae species, and Klebsiella pneumoniae, although a wide variety of pathogens can be involved. One of the greatest risks in developing a hospital-acquired pneumonia is the high prevalence of organisms that are resistant to antibiotics. Symptoms There is a wide range of symptoms associated with pneumonia, and these symptoms may begin slowly or come on rapidly. Often, individuals experience fever and chills, a cough, as well as chest pain with deep inspiration and shortness of breath. Other symptoms can include headache, nausea, vomiting, diarrhea, muscle and joint pain, and fatigue. A doctor may find that the patient has a rapid heart rate and be breathing rapidly. In addition, examination of the lungs with a stethoscope may reveal decreased air movement over the location of the infection and the sound of crackles. A chest X-ray is frequently used to confirm the diagnosis of pneumonia as well as to further localize the site of infection. For both community-acquired and hospital-acquired pneumonia, there are a number of laboratory tests that can be used to confirm the diagnosis and investigate the causative organism. Blood can be drawn from a symptomatic individual and cultured to see if bacteria are present in the bloodstream. Samples of a person’s sputum can also be cultured in search of the infectious organism. In some instances, blood tests can be used to detect the presence of high levels of antibodies to suspected pathogens because the titers of these antibodies may be increased during infection. Treatment Because the causative organism for pneumonia is often not known at the time a patient presents to the hospital, and because it may take days for the results of blood or sputum culture, patients are often treated empirically with antibiotics. The selection of antibiotics depends on the pathogens frequently seen in a
Point Mutation
particular community or hospital as well as the patterns of antibiotic resistance observed in organisms infecting the patient population at hand. Treatment may be given at the hospital through intravenous administration or by taking pills at home. The method of administration and duration of treatment will depend on the severity of the pneumonia, underlying illnesses, and other factors. Recovery from infection depends largely on the particular organism causing infection, the age and general health of the patient, and the access to healthcare facilities and medicines. SEE ALSO: American Lung Association; Immunization/
Vaccination; Influenza; Infectious Diseases (General).
Bibliography. Alan Fein and Ronald Grossman, Diag-
nosis and Management of Pneumonia and Other Respiratory Infections (Professional Communications, 2006); Michael S. Niederman, ed., Severe Pneumonia: Lung Biology in Health and Disease (Informa Healthcare, 2005); Scott H. Podolsky, Pneumonia Before Antibiotics: Therapeutic Evolution and Evaluation in Twentieth-Century America (The Johns Hopkins University Press, 2006). Christine Curry Independent Scholar
Podiatrist A podiatrist is a healthcare professional involved in the treatment of disorders of the foot, ankle, and sometimes even the knee, leg, and hip—a branch of healthcare known as podiatry. The first-known podiatrists existed in ancient Egypt as can be seen by relief carvings at the entrance to the tomb of Ankhmahor from the sixth dynasty, which show people working on hands and feet of patients. The Greek physician Hippocrates certainly refers to the need to treat corns and calluses on feet, as does Celsus, a Roman scientist and philosopher. However, it was not until the 19th century that Lewis Durlacher tried to get recognition for podiatrists as a separate professional group. In 1854, he tried to form the first association, but it was not until about 40 years later that podiatrists started to practice in some parts of the Western world.
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The Society of Chiropodists was established in New York in 1895, with the first school opening in 1911. The London Foot Hospital opened in 1911, with a school being added in 1919; in Australia, professional associations began in 1924. The first scholarly journal for podiatrists was published in the United States in 1907, with one in England started five years later. Now, the profession is regulated with the Doctor of Podiatric Medicine degree being accepted as the standard qualification in the United States. In Britain, the Society of Chiropodists and Podiatrists, with 8,000 members, regulate the profession. Important early podiatrists included Dr. William Mathias Scholl of Chicago and Dr. M. J. Lewi of New York City—now commemorated by the M. J. Lewi School of Podiatric Medicine (now the New York College of Podiatric Medicine). SEE ALSO: Foot Health; Foot Injuries and Disorders. Bibliography. Alathea V. M. Foster, Podiatric Assess-
ment and Management of the Diabetic Foot (Churchill Livingstone Elsevier, 2006); Walter Schnock, Annotations to the History of Chiropody-Podiatry in Victoria 1929–1979 (W. Schnock, 1990). Justin Corfield Geelong Grammar School, Australial
Point Mutation A point mutation or substitution in DNA research involves a mutation where the replacement of a single base nucleotide is made with another nucleotide—nucleotides being the chemical compound that is found in the structural units of DNA. Essentially, the mutation involves the insertion or deletion of a single base pair, which can have, or may lead to, a more-than-adverse effect on any synthesized protein owing to the nucleotides being read in triple sequences. Three levels of mutation are involved. The first, nonsense mutations, are a code for a stop, which can truncate the protein. A silent mutation involves the use of the code for the same amino acid, and a
1388 Point of Service (POS) missense mutation involves a code for a different amino acid. These mutations occur spontaneously in DNA replication with the rate being increased by mutagens. These mutagens vary from physical ones and can include exposure to extreme heat, X rays of ultraviolet rays, or chemical ones with molecules that misplace base pairs or disrupt the helical shape of the DNA. Mutagens associated with cancers have been the subject of much work with many researchers feeling that it might provide them with an opportunity to discover how cancer spreads, and hence, how it can be prevented. Other disorders involving point mutation include the spread of sickle cell disease where a beta hemoglobin gene converts a GAG codon into a GTG which can then encode the amino acid valine rather than the glutamic acid. SEE ALSO: DNA; Genetic Disorders; Genetics. Bibliography. J. Page and W. B. Langdon, Smooth Uni-
form Crossover with Smooth Point Mutation in Genetic Programming: A Preliminary Study (Cognitive Science Research Centre, University of Birmingham, 1998); Riccardo Poli, A New Schema Theorem for Genetic Programming with One-Point Crossover and Point Mutation (School of Computer Science, University of Birmingham, 1997). Justin Corfield Geelong Grammar School, Australia
Point of Service (POS) Point of service (POS), or point of sale, is a general term commonly used to mean that payment is rendered at the time of service. In healthcare, point-ofservice plans are more flexible and allow consumers to choose healthcare services from either a participating provider or a nonparticipating provider in the plan. POS plans have recently declined in number after a steady incline. There are many advantages and disadvantages to this type of plan, entailing factors such as freedom of choice and deductible rates.
Types of Managed Care Plans POS plans enable the consumer more freedom when it comes to selecting a provider for healthcare. There are, in general, three types of managed care plans: health maintenance organizations (HMOs), preferred provider organizations (PPOs), and point-of-service plans (POS plans). HMOs provide care at a monthly fee (which is prepaid) and, in general, provide a wide variety of services, but consumers are limited to providers within the network. PPOs offer the consumer a choice of providers within the network and payment is rendered at the time of service rather than beforehand. The PPO sponsor, generally the employer, negotiates fees for each type of service provided by the providers. POS plans incur no deductible and minimal copayments when the consumer selects a provider within the network. However, there is still an option to select a provider outside of the network, although incurring a deductible and a generally hefty copayment. With POS plans, payment is rendered at the time of service rather than beforehand. Advantages to POS Plans The major advantage of POS plans are that they offer low deductibles and copayments when the consumer selects an in-network provider, but the option is still there (in the case of extenuating circumstances) to select an out-of-network provider. With HMOs, there is limited choice of providers. With PPOs, certain services may entail high rates. With POS plans, there is a moderate degree of choice of in-network providers as well as low deductibles and copayments for many services. POS plans are also advantageous for consumers who do not consume a high amount of healthcare, because payment is rendered only at the time of service rather than prepayment. Disadvantages to POS Plans Disadvantages to POS plans are hefty copayments and deductibles when selecting an out-of-network provider. Consumers with rare diseases or who have a high likelihood of requiring an out-of-network provider may find this plan to be very costly. Conclusion Healthcare payment plans offer varying levels of choice of provider and ranges of services, with POS
Poisoning
plans generally falling somewhere in middle ground on both fronts. Employers often use these healthcare plans to lure highly qualified employees. So, it is important, as employers, to offer a plan that appeases employees. As healthcare is becoming more costly, it is important to consider what types of plans employers offer, and which plan is best for you. SEE ALSO: Health Maintenance Organization (HMO); In-
surance; Managed Care.
Bibliography. American Association of Retired Persons,
“Managed Care,” www.aarp.org/health/insurance/managed_care (cited January 2007); Jan Davison and Maxine Lewis, Working with Insurance and Managed Care Plans (McGraw-Hill, 1999); Managed Care Magazine, “Archives,” www.managedcaremag.com (cited January 2007). Bradley E. Goldstein, M.S., M.P.H. Lake Erie College of Osteopathic Medicine
Poisoning Poisons are, biologically, substances that can cause damage, illness, or death to organisms, usually by a chemical reaction or other activity on the molecular scale, after a sufficient quantity of the substance is absorbed by an organism. As a result, poisoning is the act of an organism in absorbing the poison. In medicine, there are toxins that are produced through a biological function in nature, and there are also venoms that are usually injected by a bite or a sting to cause their effect. Poison, medically, is generally regarded as a substance that damages, causes illness, or causes death to someone after it is absorbed through the epithelial lining such as the skin or the gut. As a result, people are usually said to have become ill after, or died from a snake bite, rather than from snake poison. The main exception, in general parlance, is the use of poison on weapons such as arrows, knives, or darts—especially curare used on blow darts by some South American Indian tribes, and the Dayaks in Borneo. The Swiss alchemist Paracelsus is said to have stated that everything is poison, and there is poison in everything; however, the dose many make something not a poison. There is some truth in this as many common
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“poisons” when taken in low doses have medical benefits. The warfarin tablets taken by heart patients to thin their blood is essentially similar in some manner to rat poison. Many inoculations involve the injection or ingestion of a small portion of diseased bacteria to help the body build up resistance. However, there is a legal definition of poison, and items deemed to be poisonous have to be marked with a skull and crossbones, the internationally accepted sign of poison. Many children are accidentally poisoned, often when they eat something they are not supposed to. Indeed, poisoning remains the fourth most common cause of accidental death in children in the United States and many other developed countries. The taking of poisons by accident is most common in children under the age of 5, with older children occasionally taking tablets prescribed for other people, poisonous items in the house such as anti-insect powders, or medications in the wrong doses. Some 90 percent of these poisonings take place in the home, with the most common areas being the kitchen and the bathroom. In the former, children have been known to consume soap powders, cleaning fluids, anti-insect powders, and the like, with the consumption of cleaning fluids or medication intended for somebody else or for them in limited doses being common in
Poisoning remains the fourth most common cause of accidental death in children in the United States and many other developed countries.
1390 Poisoning the bathroom. To try to reduce this, many bottles of medically prescribed tablets are equipped with child safety caps, as are bottles of liquids that are poisonous such as paraffin, turpentine, and kerosene. Not only are small children often involved in consuming things they should not, but their body system is such that their reactions to poisons are more severe than those in adults. Parents and other people minding children are always advised to keep all medication properly labeled, out of reach of small children, and if possible, to lock medicine in a cabinet. There is always a hazard in accidental poisoning whereby somebody consumes something that they do not realize is poisonous, or consumes it in a far larger amount than is healthy for them. The latter may involve taking a far-too-high dose of a particular medication, especially when a patient is unsure whether they have missed a previous dose. This can often be the case with medicines such as steroids which have to be taken in a strict regimen, without missing any dosage. When people forget to take them, some try to take more on the next occasion to compensate for the dosage missed, often causing more problems and placing themselves at serious risk of being poisoned. Another area of accidental poisoning is when people unknowingly consume something poisonous that they thought was safe. This may be owing to faulty packaging or the wrong product being put in the container, but this is relatively rare. More often, it happens when a food container is reused for the storage of something poisonous, and the person forgets or is unaware that this has happened, and hence accidentally consumes poison. For this reason, a part of the health and safety training for children (and others) involves ensuring that they keep harmful products away from edible ones, and that people, before they eat, always wash their hands after dealing with hazardous items. Food poisoning is another hazard when foods are either not prepared properly, or have passed their “use by” date, after which they should no longer be consumed. This has become more common with many products no longer being eaten fresh. With many foods kept in refrigerated conditions, in refrigerators or deep freezers, if the goods accidentally thaw out early, often through an electrical fault or the power to the freezer being disconnected for another reason, the food may still appear to be all right, but food poi-
soning may result if it is consumed. Likewise, when food is brought out of the deep freezer and not properly thawed while it is being cooked—i.e., not cooked through—the consumption of this may also lead to food poisoning, often through salmonella. This is particularly the case with chicken, fish, and pork. Environmental poisoning takes place when an area becomes accidentally or deliberately polluted. The former may have come from an accident, such as that at the nuclear power plant at Chernobyl on April 26, 1985, or the oil slicks from the Exxon Valdez and other oil tankers, or it may be from something as small as a fracture in a pipe carrying something toxic. Deliberate poisoning can take place when someone deliberately uses herbicides or pesticides to destroy flora. It the chemicals are used carelessly and nearby crops or fruit trees are affected, this may result in food being poisoned. The use of lead pipes in the Roman Empire is said to have resulted in many deaths through accidental poisoning. Another example concerns the nonaccidental but nondeliberate poisoning which may occur when, for instance, one field is being sprayed and other nearby fields are affected. The worries concerning the indiscriminate use of DDT in the 1950s led Rachel Carson to write her book Silent Spring (1962) in which she described the link between environmental pollution and the poisonous effects it had on many animals, especially on birds, which eventually led to the ban of DDT in the United States in 1972. Lead poisoning from car fumes has also become serious. Poisoning has long been a method to committing suicide. This has varied from the taking of large numbers of prescription medicines, such as painkillers, to using traditional poisons such as arsenic, strychnine, or cyanide. Often, it is regarded as a sure and relatively painless way of committing suicide, with many people using suicide tablets to prevent themselves being captured alive or being executed. In the ancient world, many leaders had vials of poison to prevent their capture and torture. Adolf Hitler took his own life with cyanide, also shooting himself at the same time to make sure that he died. Other Nazi leaders also committed suicide using poison. The propaganda minister Josef Goebbels also took poison to prevent capture; the head of the SS, Heinrich Himmler, took poison after he was captured; and the head of the Luftwaffe, Hermann
Poland
Goering, took poison just before he was to be executed at Nuremberg. Nedeljko Cabrinovic tried to kill himself by taking poison after his failed attempt to kill Archduke Franz Ferdinand in Sarajevo in 1914—the Archduke was killed later the same day by another conspirator; and the leader of the Vichy French government, Pierre Laval, took poison to try to stop himself being executed by firing squad. A doctor saved him from dying by poison, and Laval was then shot. Other people have committed suicide by poisoning themselves with car fumes. Similar poisons—arsenic, strychnine, or cyanide— have also been used for the deliberate poisoning of people. There are numerous examples of poisoning in the Greek and Roman worlds. There are a number of theories as to whether Alexander the Great was poisoned, with the Roman emperor Claudius certainly being poisoned, the poison concealed in a plate of mushrooms. In Renaissance Europe, poisoning was so common that before meals it became common to pour wine from glass to glass, a habit that partially remains with the “chinking” of glasses before meals. The Borgia family in Renaissance Rome, particularly Cesare Borgia, became well known as poisoners. So fearful were people during that period of being poisoned that the penalties for poisoners were far worse than those for murderers. In England during the reign of King Henry VIII, poisoners were boiled alive, being lowered slowly into a cauldron of boiling water. Many detective stories involve poisonings with some of those in Umberto Eco’s The Name of the Rose (1983) being perhaps the most inventive. In Imperial Rome, Imperial China, and in many other places, there were always official food tasters who had the responsibility to try to ensure that people were not poisoned. In Imperial China and, more particularly, in Imperial Vietnam, errant court officials would be sentenced to be ordered to take poison or be executed—the taking of poison was regarded as more honorable as well as less humiliating and painful. Socrates in ancient Greece also faced the same fate, having to take hemlock. Mention should also be made of using poisonous gas to kill people, sometimes in specially constructed gas chambers such as in the Holocaust during World War II, or as a method of execution in some parts of the world. SEE ALSO: Homicide; Pesticides; Suicide.
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Bibliography. John Emsley, Elements of Murder (Oxford University Press, 2005); Jerome O. Nriagu, Lead and Lead Poisoning in Antiquity (Wiley, 1983); Jean Plaidy, A Triptych of Poisoners (Robert Hale, 1958); J. A. Vale and T. J. Meredith, Poisoning: Diagnosis and Treatment (Update, 1981); Christian Warren, Brush with Death: A Social History of Lead Poisoning (Johns Hopkins University Press, 2000).
Justin Corfield Geelong Grammar School, Australia
Poland The Republic of Poland is one of the most successful of the transition economies. In the 1990s, as Poland began its transformation into a market economy, a so-called “shock therapy” program reformed the entire system. With a per capita income of $13,000, Poland now ranks as the 73rd richest nation in the world. Unemployment has, however, continued to rise, increasing from 6.3 percent to 16.4 percent between 1990 and 1993. At present, Poland’s unemployment rate (18.2 percent) is the highest among members of the European Union (EU). Inflation initially soared during the early transition from a social to a market economy, climbing to 71 percent in 1991. Within three years, the inflation rate had dropped to 10 percent. In 2005, it had declined still further (2.2 percent). Poland continues to be adversely affected by a dilapidated infrastructure. Although the Polish economy is diversified, 16.1 percent of the labor force is engaged in the agricultural sector. The fall of socialism in Poland increased income disparities. By 1999, 14.4 percent of the population was living below the poverty line; today, that number has increased to 17 percent. Most of those who live in abject poverty are concentrated in rural areas. Poland ranks 34.1 on the Gini Index of Inequality. The richest 10 percent of Poles claim 26.7 percent of the country’s income, leaving 3.1 percent for the poorest 10 percent. Nevertheless, the standard of living is among the highest in the former socialist republics, and the United Nations Development Programme (UNDP) Human Development Reports rank Poland 37 of 177 countries on overall qualityof-life issues.
1392 Poland The history of health insurance in Poland can be traced to the period between the two world wars when a limited insurance plan was instituted, covering only 7 percent of the population. In the post–World War II era, healthcare became a public responsibility, and the central government assumed responsibility for the healthcare system. Unlike most Soviet republics, Poland refused to abolish private practice for physicians. In the 1950s, further healthcare reforms led the government to provide coverage for state employees, and occupational health clinics became a standard fixture of the workplace. In the 1980s, the government began decentralizing the healthcare system, transferring responsibility to local governments (viuvidsguos). In 1997, the Universal Health Insurance Act was enacted to provide for mandatory universal medical coverage, with the state guaranteeing insurance security. At that time, healthcare taxes were phased out, and 17 “sickness funds” were established to finance healthcare. The National Health Program of 1996–2005 established 18 target goals, which included promoting healthier lifestyles and preventive health and improving the quality of health services. Because of the decentralization of healthcare services, only 2 percent of the government’s total budget is allocated to health. The government spends 6.5 percent of the Gross Domestic Product (GDP) on healthcare, allotting $745 (international dollars) per capita. Health spending accounts for 69.9 percent of all health expenditures, and 86 percent of this amount is directed toward providing social security. The private sector accounts for 30.1 percent of health expenditures. Around 88 percent of all private expenses are generated from out-of-pocket expenses. There are 2.47 physicians, 4.90 nurses, 0.57 midwives, 0.30 dentists, and 0.77 pharmacists per 1,000 population in Poland. Among Polish males, urban men have a higher life expectancy than do rural males. However, this trend is reversed among females, with rural women outliving urban women. Overall, the population of 38,536,869 experiences a life expectancy of 74.97 years, and women outlive men an average of five years. Life expectancy has increased in Poland since the advent of democracy, but Poles continue to lag behind most other nations of the EU. The literacy rate is 99.8 percent, and primary enrollment is 98 percent. Secondary enrollment is among the highest of the former Soviet republics. All Polish residents have access to
safe drinking water. Almost half of all Polish women use some method of birth control, and Poland has the 10th lowest fertility rate (1.25 children per female) in the world. All births in Poland occur in the presence of trained personnel, and the adjusted maternal mortality ratio is 13 deaths per 100,000 live births. Between 1990 and 2004, infant and under-5 mortality dramatically plunged from 19 to seven deaths per 1,000 live births and from 18 to eight deaths per 1,000 live births, respectively. The current infant mortality rate is 7.22 deaths per 1,000 live births. Six percent of all Polish children are underweight at birth. Among the infant population, 99 percent are immunized against diphtheria, pertussis, and polio (DPT1 and DPT3); 98 percent against polio; 97 percent against measles; and 94 percent against tuberculosis. Since the breakup of the Soviet Union, Poland has been faced with the aftermath of heavy industrialization and years of disregarding the environment. Sulfur dioxide emitted by coal-burning power plants continues to threaten general health. Water supplies are also at risk from irresponsible disposal of wastes, and environmentalists are deeply concerned about the issue of hazardous waste disposal. Some 14,000 people are living with HIV/AIDS in Poland, which has an adult prevalence rate of 0.1 percent. However, due to advanced drug therapy and treatment options, fewer than 100 people have died from the disease. Poland was one of several countries that identified incidences of severe acute respiratory syndrome (SARS) in spring 2003. The major causes of death in Poland include cardiovascular diseases, cancer, and accidents, and all are to some degree influenced by lifestyles and behavior. Compared to other European countries, mortality from lung and cervical cancer rates are high; however, breast cancer rates are significantly lower than those in other Eastern European nations. Ischemic heart disease has also been treated effectively, but success rates on treatment of cerebrovascular heart disease have been limited. Mortality rates for lung cancer are largely due to the fact that Poland’s smoking population is one of the largest in Europe. Among the male population between the ages of 15 and 34, most deaths result from external causes. While Polish males are more likely than males in other EU nations to die from external causes, Polish females have one of the lowest external mortality rates among EU members.
Pollution
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SEE ALSO: Environmental Health; Healthcare, Europe. Bibliography. Central Intelligence Agency, “Poland,”
World Factbook www.cia.gov/cia/publications/factbook/ geos/pl.html (cited May 2007); Commission on the Status of Women, “Poland,” www.un.org/womenwatch/daw/Review/ responses/POLAND-English.pdf (cited May 2007); Martin A. Levin and Martin Shapiro, eds., Transatlantic Policymaking in an Age of Austerity: Diversity and Drift (Georgetown University Press, 2004); Social Security Administration, “Poland,” www.ssa.gov/policy/docs/progdesc/ssptw/20022003/europe/poland.html (cited May 2007); United Nations Children’s Fund, “Poland,” www.unicef.org/infobycountry/ poland_statistics.html (cited May 2007); World Bank, “Poland Data Profile,” http://devdata.worldbank.org/external/CPProfile.asp?PTYPE=CP&CCODE=POL (cited May 2007); World Health Organization, “Highlights on Health in Poland,” http:// ec.europa.eu/health/ph_projects/1999/monitoring/poland_ en.pdf (cited April 2007); World Health Organization, “Poland,” www.who.int/countries/pol/en/ (cited April 2007). Elizabeth R. Purdy, Ph.D. Independent Scholar
Pollution The concept of pollution consists of the inappropriate or undesirable mixing of items or elements that may in themselves be quite appropriate or desirable. An item of food on a plate is an item that is desirable, clean, and in its right place; if the food item falls off the plate onto the floor, then it suddenly becomes dirty and undesirable—it has been polluted by contact with the floor. In traditional Indian society, people are divided into castes and a person from the highest, Brahmin caste, will fear pollution from proximity to a person from the lowest Untouchable (Dalit) caste or something touched or manufactured by such a person. Although the two people in themselves may be quite virtuous and valuable in their own right, their coming together results in contamination or pollution. In the early part of 2007, a boat carrying cargo of many tonnes of sugar capsized in the Chao Phraya River, north of Bangkok. The sugar entered the water, lowered the level of oxygen in the water, and led to
The processes of industrialization have greatly increased the production of new types of pollution and the intensification of existing forms.
the deaths of many thousands of fish being raised by people along the length of the affected water. Characteristically, then, the act of pollution is caused by a pollutant which is generally a very desirable and valuable item. Nevertheless, the interaction that it has had with the surrounding environment has led to disastrous results. Environmental pollution involves the addition of a new substance into the environment and this has a negative impact on some or all of the living creatures in that part of the environment. The substance may be tangible or intangible in nature: carbon particles in the air can lead to respiratory diseases, but noise can also provoke sleeplessness, stress, and cardiovascular problems. Although pollution is thought of as being produced exclusively by human activities, there are also forms of naturally occurring pollution (i.e., without human involvement) when, for example, rotting vegetation reduces water quality in a river or well. Even so, the processes of industrialization have greatly increased the production of new types of pollution and the intensification of the severity of existing forms. People living in urbanized areas tend to suffer disproportionately from the impact of pollution; as the numbers of people living in cities continues to increase, especially in the developing world, the impact of pollution on humanity will also increase
1394 Pollution and the need for more efficiency in production and supervision to prevent breaches of legislation on pollution will be magnified. The principal forms of pollution include air pollution, water pollution, and land pollution. Air pollution includes the release of a wide range of particles and gases into the atmosphere. Much air pollution arises from the burning of hydrocarbon fuels, either as part of power plant operation or through operating personal automobiles. Because air moves, the impact of pollution may be felt quite a long way away from the place where it was caused. Acid rain, for example, created by industrial activity in Britain fell on the forests of Scandinavia, while the intense industrialization of China has given rise to air pollution which has begun to cause disease in the United States as well as closer to home. Despite the impact of human involvement in air pollution, this can be dwarfed by the effect of volcanic explosions which can release millions of tonnes of pulverized rock and dust into the atmosphere. The effect of the explosion of Tambora in Indonesia in 1815 killed perhaps 10,000 people outright from the blast and the tsunami waves and the resulting air pollution led to deposit of ash and waste on agricultural land subsequently caused famines killing about 80,000 people. Water pollution involves the release of any type of material into waterways and subsequent impacts on people and other living creatures which draw upon the resources of that waterway. In some cases, the pollution can have some apparent beneficial effects: for example, power plants or other industrial facilities release thermal energy into the water and this can lead to a blooming of life-forms in the vicinity. However, most types of water pollution are much less positive and involve the killing of maritime creatures or of plants living in or next to the water. In some cases, water pollution leads to a chain of events that can lead to concentrated effects after some years. Mercury released into the sea can reside inside fish and build in its actual level until, when the fish is caught and processed for human food, it then represents a serious threat to health. Many millions of people rely on rivers and the resources they provide. Some 50 million people rely upon the Mekong River, for example, and the livelihoods of many of these people will be threatened if cargo boats
now carrying oil to southern China run aground or lose their cargo. Land pollution involves the introduction of nonbiodegradable waste matter into the land, either in designated waste storage facilities or, perhaps illegally, in nondesignated areas. Biodegradable items can still cause problems if they are present in nonmanageable concentrations. Nonbiodegradable items are more problematic: there are now significant problems with the amount of waste materials being gathered in urban areas, including for example disposable diapers, mobile telephone batteries, personal computer equipment, and automobile tires. Large dumps of these products are difficult to dispose of effectively— the most likely option is to burn them, but this leads to air pollution and may not be possible in any case. An international trade is being created in the export of this waste, generally moving it from developed countries to developing countries, which have fewer resources for effectively dealing with it. Dumps close to large, developing country cities can act as a magnet for poor people as a place for scavenging for salable items or even as a home. Clearly, many health issues derive from such a situation. In recent years, citizens and governments have started to realize the importance of pollution as a contributor to global warming and because of the health issues resulting from it. Of course, some people have been drawing attention to the impact of pollution for centuries and attempting to bring about societal and legal change to end it. However, the modern world has produced hugely more human-created pollution that ever before and awareness of what is happening around the world is so much more accessible than before that people are much more attuned to the issues. Consequently, there is a great deal of political will (although not always able to constitute an effective majority in a democratic country) for pollution guidelines which are properly enforced and with sanctions which have a genuinely deterrent effect. A general realization is also occurring that this may be better managed through international consensus rather than on the level of individual states. SEE ALSO: Environmental Health; Environmental Protec-
tion Agency (EPA)
Bibliography. C. David Cooper and F. C. Alley, Air Pollution Control (Waveland Press, 2002); Marquita K. Hill, Un-
Polio and Post-Polio Syndrome
derstanding Environmental Pollution: A Primer (Cambridge University Press, 2004); Ian L. Pepper, Environmental and Pollution Science (Academic Press, 2006). John Walsh Shinawatra University
Polio and Post-Polio Syndrome In 1895, Gould’s Medical Dictionary defined poliomyelitis as follows: Acute inflammation of the anterior horns of the gray matter of the spinal cord, leading to a destruction of the large multipolar cells of these horns. It is most common in children, coming on during the period of the first dentition and producing a paralysis of certain muscle groups or of an entire limb. This definition has barely changed over the last century. In 1916, New York City experienced the first large epidemic of polio, with over 9,000 cases and 2,343 deaths. The 1916 toll nationwide was 27,000 cases and 6,000 deaths. Epidemics worsened during the century: In 1952, a record 57,628 cases of polio were reported in the United States. Polio (also called infantile paralysis) is most often associated with children, but at its peak, it affected teens and grown-ups as well (although far fewer in number). Between 1949 and 1954, 35 percent of those who contracted polio were adults. The first known polio outbreak in the United States was reported from the State of Vermont, in 1894, and is documented by Dr. C. S. Caverly, secretary of the State Board of Health in that year: “Early in the summer just passed, physicians in certain parts of Rutland County, Vermont, noticed that an acute nervous disease which was almost invariably attended with some paralysis, was epidemic … and a general feeling of uneasiness … was perceptible among the people in regard to the ‘new disease’ that was affecting the children.” The last cases of wild (naturally occurring) polio in the United States were in 1979 in four states, among Amish residents who had refused vaccination. Throughout most of the 20th century, hospitals operated under strict and orderly patient regimens. Epidemic conditions, combined with the lack of a
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cure for polio, heightened everyone’s anxiety. During a 1934 epidemic in Los Angeles, 5 percent of doctors and 11 percent of nurses who treated polio patients contracted the disease. Some historical highlights in the history of polio are as follows: • 1789—Dr. Michael Underwood, a British physician, provides first clinical description of the disease • 1894—First outbreak of epidemic polio in the United States occurs in Vermont, with 132 cases • 1921—Franklin D. Roosevelt (FDR) contracts polio. He is 39 years old. He is elected as president of the United States in 1933 • 1938—FDR founds the National Foundation for Infantile Paralysis, currently known as the March of Dimes • 1940s—A nurse from Australia, Sister Kenny, starts to promote her polio treatment/rehab in the United States • 1953—Dr. Jonas Salk and his associates at the University of Pittsburgh develop an inactivated injected polio vaccine • 1962—The Salk vaccine is replaced by the Sabin vaccine, an orally administered live vaccine • 1979—The last case of wild-type polio in the United States • 1980s—Post-polio syndrome (PPS) identified • 1988—Rotary International, Pan American Health Organization (PAHO), World Health Organization (WHO), U.S. Centers for Disease Control and Prevention (CDC), and United Nations Children’s Fund (UNICEF) start the Global Polio Eradication Initiative (GPEI) • 1999—The United States returns to Salk’s inactivated polio vaccine Epidemiology and Transmission The predominant age of polio susceptibility is 3 months to 16 years; rarely do adults now contract the disease. Polio is an extremely rare infection in the United States since the introduction of effective vaccines. Worldwide, there were 1,593 cases in 2006, and 1,486 cases in 2005. Endemic countries at the end of 2006 remain Afghanistan, India, Nigeria, and Pakistan, although outbreaks or imported cases may periodically be found elsewhere. Risk factors include poor sanitation and hygiene; poverty and other social
1396 Polio and Post-Polio Syndrome determinants of the above; and unimmunized status, especially if under 5 years of age. Poliovirus initially infects the gastrointestinal tract. It may spread to regional lymph nodes and, in some cases, to the central nervous system. Pharyngeal spread is less common but is the prevalent mode of transmission in areas of good hygiene. Person-to-person spread is the most common means of transmission; contaminated water and sewage less so. Vectorborne transmission has not been demonstrated. There are three serotypes of poliovirus (genus Enterovirus): type 1 is most frequently associated with epidemics; and types 2 and 3 usually associated with vaccine-associated paralytic polio (VAPP). While the majority of polio infection is asymptomatic, about 10 percent will show signs and symptoms of a minor gastrointestinal illness, including fever, malaise, nausea, and vomiting. A minority of the above will progress to the “major illness,” which includes asymmetric paralysis of extremities (usually lower). There can be significant motor loss on affected side or limb. Meningeal signs may be present in minor illness or early phases of paralytic polio. The majority of patients contracting the poliovirus are asymptomatic; approximately 5 percent develop symptoms, and 0.1 percent develop the paralytic form of poliomyelitis. Diagnosis, Prevention, and Treatment Paralytic polio has no definitive curative treatment. The approach to managing polio involves prevention and management of sequelae. Diagnosis is made via analysis of spinal fluid virus isolation from throat (early in disease) and/or feces (early and late in the disease). Magnet resonance imaging (MRI) may be helpful to evaluate involvement of the spinal cord or other findings. There are two ways to get immunity: infection or immunization. Prevention is accomplished mainly through the latter. Developed settings utilize the inactivated polio vaccine (IPV), administered via injection. The live, attenuated oral polio vaccine (OPV) is used in the developing setting or where wild-type poliovirus remains endemic. OPV induces circulating antibodies in the recipient, and because it is excreted via the gut, it can immunize susceptible contacts in the community through waterborne spread. The World Health Organization (WHO) recommends OPV for
exclusive use in developing countries because of its low cost, ease of administration, and potential for population-based immunization. IPV provides effective protection to the individual recipient but lacks the community immunization effect of OPV. However, OPV administration carries a small risk of vaccineassociated paralytic polio (VAPP), which IPV does not. The latter is thus considered safer for developed settings where wild-type polio has been eradicated. The U.S. vaccination schedule calls for IPV to be administered four times: at ages 2 months, 4 months, 6 to 18 months, and 4 to 6 years of age. The live attenuated oral polio vaccine (OPV) was developed by Dr. Albert Sabin in 1961. The inactivated (killed) polio vaccine (IPV), was developed in 1955 by Dr. Jonas Salk and is an injected vaccine. OPV (Sabin) provides immunity to all three strains of polio and induces humoral immunity systemically as well as local gastrointestinal mucosal immunity (which limits transmission during outbreaks). IPV (Salk) also induces humoral immunity via antibodies. However, it induces very low levels of immunity to poliovirus locally, inside the gut. As a result, it provides individual protection against polio paralysis, but unlike OPV, it cannot prevent the community spread of wild poliovirus. IPV cannot cause vaccine-associated paralytic polio (VAPP). OPV can but does so at a rate of just 1/2.5 million doses. The United States started using OPV in 1961, and switched to IPV in 1999. The benefits of using OPV for global public health programs are (1) easy to administer (oral drops); (2) relatively inexpensive (8 cents a dose) versus the cost of IPV (almost $1 a dose with syringe, not including cost of health worker); (3) short-term shedding of live virus from immunized children will likely immunize others via contact; (4) it interrupts transmission during outbreaks due to mucosal GI immunity. Once contracted, the main treatment for polio is supportive, including pain control, hydration, and monitoring for bulbar or respiratory paralysis. This particularly devastating complication can paralyze the respiratory muscles and necessitate the use of a ventilator. Paralytic poliomyelitis cases exhibit the flaccid paralysis, which is a hallmark of the disease. Early mobilization of the affected limb(s) is essential: a focused physiotherapy and rehabilitation regimen can minimize the level of disability resulting from polio. Counseling for the patient, caregivers, and family is useful as the disease has lifetime sequelae.
Post-Polio Syndrome Post-polio syndrome (PPS) affects those previously infected with poliovirus and usually manifests years or even decades after the initial infection and recovery. It involves muscle wasting and atrophy unrelated to the muscle groups affected by the initial infection. Experimental treatments for PPS include intravenous immunoglobulin (IVIG), presently under investigation. A number of other agents, including amantadine, pyridostigmine, and modafinil, have been studied but have failed to demonstrate efficacy. As with paralytic poliomyelitis, early physiotherapy and nonfatiguing exercises are the main feature of PPS treatment. The main symptoms are new, progressive muscle weakness, severe fatigue, and pain in muscles and joints. Less common symptoms include muscle atrophy, breathing and swallowing difficulties, sleep disorders, and cold intolerance. The exact mechanism by which PPS causes fatigue, pain, and new weakness is not completely understood. It may possibly be related to the gradual loss of individual nerve cells, and subsequent loss of nerve transmission to these fibers. After the original polio infection, surviving nerve cells sprout extra branches that reattach to muscle fibers. Although the muscle fibers occasionally work as well as before, some suggest that PPS develops because these extra axonal sprouts cannot “hold” forever, but instead get weaker over time due to overexertion. The Global Polio Eradication Initiative (GPEI) Poliomyelitis, also known as infantile paralysis, is currently targeted for eradication. In 1988, at the World Health Assembly (WHA) annual meeting, the ministers of health of all member states of the WHO voted to launch a global goal to eradicate polio. As a result, the largest public health effort to date was put together: the Global Polio Eradication Initiative (GPEI). When GPEI was launched, wild poliovirus was endemic in more than 125 countries on five continents, paralyzing more than 1,000 children every day. Since 1988, some 2 billion children around the world have been immunized against polio. Funding has exceeded $3 billion to date. The major participants in the GPEI are the WHO, Rotary International, the CDC, and UNICEF. In 1987, Rotary International launched a $120 million campaign for polio. The campaign raised $247 mil-
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lion in one year. The main organizations have distinct and sometimes complementary roles. WHO’s polio group, under Dr. David Heymann’s direction, has been responsible for the overall coordination of National Immunization Days (NIDs), as well as technical assistance and strategy. Rotary International promotes advocacy and funding at the global and local country levels. The CDC provides technical expertise, polio surveillance, laboratory support, and epidemiologic investigations. UNICEF assists with field-based support for polio vaccination as part of its own expanded programme on immunizations (EPI) initiative. By the end of 2003, as a result of GPEI efforts, the number of countries with endemic polio had shrunk to six: Afghanistan, Egypt, India, Pakistan, Niger, and Nigeria. The early leader in eradication of polio was Latin America: the Pan American Health Organization (PAHO) committed in 1985 to eradicate polio from the Americas. The last case in the Americas was in 1991: a 3-year-old boy (Luis Tenorio) in Peru. In 1995, a Global Commission for Polio Eradication was formed, and it prepared regional plans which gave rise to GPEI’s current structure. Some particular and interesting achievements have been realized. In 1995, Afghanistan allowed a third national one-day war ceasefire for immunizations to happen. Also in 1995, India conducted its first National Immunization Day (NID), vaccinating a historic 87 million children. The last case in China was in 1996; the last case in the western Pacific region (the second to be polio-free) was in 1997 (Cambodia). If the eradication program goes according to plan, cessation of OPV is planned by 2008. Polio outbreaks caused by vaccine-derived polioviruses (VDPVs) have shown that continuing the use of oral polio vaccine (OPV) for routine immunization could compromise the goal of eradicating all paralytic disease due to circulating polioviruses. To minimize the risks associated with the use of OPV, it is generally agreed that routine global use of OPV should stop as soon as possible after global certification of eradication. The future of GPEI post–2009 is to work on “mainstreaming.” This would minimize the perception of this being a “vertical program,” and allow the continued support of delivery of other health services, such as the distribution of vitamin A supplementation, integrated disease surveillance, routine immunization services,
1398 Polycystic Kidney Disease and the implementation of activities of the Global Alliance for Vaccines and Immunization (GAVI). Some particular challenges have plagued polio eradication, and most of these have to do with conflict zones that do not allow for uniform and wide distribution of polio vaccines. There have also been some region-specific setbacks which have underscored the value of sustained public health efforts. In Nigeria, some states suspended polio immunization in August 2003, following concerns regarding the safety of the polio vaccine. A new outbreak occurred, originating in one of those states, reinfecting previously polio-free areas within Nigeria. In addition, eight previously polio-free countries across Africa were reinfected as well. There are some predictable issues as well, such as increasing resources being spent on smaller number of cases: an epidemiological reality, where the effort to reach the final few cases will be the greatest. This, in turn, can result in donor fatigue, as well as health worker fatigue and frustration, with repeated rounds of immunizations to reduce the shrinking number of cases. SEE ALSO: Afghanistan; Immunization/Vaccination. Bibliography. R. B. Aylward, “Poliomyelitis,” in D. L. Heymann, ed., Control of Communicable Diseases Manual, 18th ed. (American Public Health Association Press, 2004); T. Brookes and O. A. Khan, The End of Polio? (American Public Health Association Press, 2007); E. Farbu, et al., EFNS Guideline on Diagnosis and Management of PostPolio Syndrome,” European Journal of Neurology (v.13, 2006); National Institute of Neurological Disorders and Stroke (NINDS), National Institutes of Health, “Brain Resources and Information Network (BRAIN),” www.ninds. nih.gov (cited October 9, 2006); D. M. Oshinsky, Polio: An American Story (Oxford University Press, 2006)
Omar A. Khan, M.D., M.H.S. University of Vermont
Polycystic Kidney Disease The term “polycystic kidney disease” is usually used to refer to autosomal dominant polycystic kidney disease and autosomal recessive polycystic kidney disease. In these disorders, genetic mutations result
the formation of multiple cysts, which are fluid-filled spaces lined with a layer of cells. The cysts cause physical symptoms and kidney dysfunction, and can be seen on ultrasound. There is currently no cure for polycystic kidney disease, and most patients eventually develop kidney failure. Autosomal dominant (adult) polycystic kidney disease Autosomal dominant polycystic kidney disease (ADPKD) is a common inherited condition, affecting one in 400 to one in 1000 births. It has a gradual course, and kidney failure usually develops after decades. As a result, it is also called “adult polycystic kidney disease”. “Autosomal dominant” refers to how the disease is passed on to later generations: only one gene from one parent is necessary for a child to have the disease, and there is a 50 percent chance that a child of an individual with no ADPKD genes and an individual with one normal and one ADPKD gene will be affected. The genes responsible for this disorder are on chromosome 4 and 16, named PKD2 and PKD1 respectively. Individuals with mutations of the PKD1 gene tend to develop kidney failure earlier than those with mutations of the PKD2 gene. The exact pathway by which these mutations and resulting dysfunctional proteins lead to cyst formation has yet to be decided conclusively. The numerous cysts grow and subsequently damage normal kidney tissue, causing physical symptoms and problems with the kidney. Apart from in the kidney, cysts can also form in the liver, pancreas, lungs, or spleen. Dull or stabbing pain in the back and the sides is the most common symptom of ADPKD. Headaches may occur. Other associated conditions include bloody urine, high blood pressure, urinary tract infections, abnormal heart valves, kidney stones, and diverticulosis, or small pouches of the colon. Sometimes, the amount of protein in the urine may be increased. Infections and kidney stones may result in persistent pain. ADPKD is associated with brain aneurysms, where there are bulges in the walls of blood vessel in the brain. Autosomal recessive (childhood) polycystic kidney disease Autosomal recessive polycystic kidney disease (ARPKD) is a rare inherited disorder. It affects one in 6000 to 55,000 births. Like ADPKD, ARPKD involves
cysts that damage the kidneys and other organs, but it causes symptoms in the newborn period or early childhood, leading to the alternate name of “childhood polycystic kidney disease”. The gene involved in ARPKD is PKHD1, on chromosome 6. “Autosomal recessive” means that both parents must have a defective copy of this gene, and there is a 25 percent chance that the child of those two individuals will have ARPKD. How a mutation in this gene and resulting dysfunctional protein leads to cyst formation and disease is still not completely clear. As in ADPKD, the cysts cause physical symptoms and problems with kidney function. There are varying degrees of severity in ARPKD. Subcategories of ARPKD are based on when symptoms appear. Half die quickly after birth due to complications. Those who survive the newborn period may live into their twenties. Problems associated with ARPKD include pain, high blood pressure, urinary tract infections, and kidney failure. Other organs such as the liver, pancreas, and spleen are affected as well. In the fetus, kidney dysfunction also leads to lung problems. Complications of high blood pressure, such as congestive heart failure, may develop later. The degree to which the liver is affected is inversely related to the degree of kidney involvement. In particular, ARPKD tends to cause scarring of the liver as the individuals with milder kidney disease grow older. Such an individual can develop symptoms of liver cirrhosis, such as hemorrhoids and varicose veins. Diagnosis Ultrasound is the test of choice to diagnose polycystic kidney disease. This involves using sound waves to create images. Ultrasound can detect kidney cysts in a fetus. While ultrasound cannot distinguish between cysts of ADPKD and ARPKD, it can detect liver scarring if present in older children, which would indicate ARPKD. In addition, performing ultrasounds on family members will aid diagnosis, as parents are unaffected in ARPKD but are affected in ADPKD. When ultrasound results are unclear, computed tomography, which uses x-rays, is used. Treatment There is currently no cure for polycystic kidney disease, and eventually the patient develops kid-
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ney failure. Once this happens, affected individuals will need kidney transplantation or dialysis in order to survive. Before kidney failure occurs, treatment is directed towards pain control and treating various complications. Pain medications and surgery are options for relieving pain, although neither of these will prevent kidney failure. Antibiotics are used to treat urinary tract infections. Controlling high blood pressure may slow progression to kidney failure. SEE ALSO: Genetic Disorders; High Blood Pressure; Kid-
ney Diseases (General); Kidney Failure and Dialysis; Kidney Transplantation. BIBLIOGRAPHY. Barry M Brenner and Samuel A Levin,
Brenner and Rector’s The Kidney, 7th edition (Saunders, 2004); Vinay Kumar, et al., Robbins & Cotran Pathologic Basis of Disease, 7th ed. (Saunders, 2004). Ikue Shimizu Brown Medical School
Polymerase Chain Reaction (PCR) Polymerase chain reaction (PCR) is a rapid and powerful procedure that is used to produce millions of copies of a specific DNA sequence from a single DNA fragment. For inventing the procedure, Kary B. Mullis was awarded the Nobel Prize in Chemistry in 1993. The original double-stranded DNA fragment is denatured (separated into two single strands by raising the temperature) and each strand acts as a template from which a complementary DNA copy is produced. The complementary copies then act as additional templates in subsequent cycles. Thus, one cycle of amplification would result in four DNA strands and two cycles of amplification would result in eight DNA strands. After 20 to 30 cycles of exponential amplification, millions of copies of the original strand are produced. PCR is performed using a heat-stable DNA polymerase (Taq polymerase). This enzyme amplifies specific regions of DNA by adding nucleotides to synthetic single-stranded oligonucleotide sequences
1400 Polymorphism called primers. The primers are short sequences of approximately 20 nucleotides which are identical to either the 20 nucleotides preceding the target sequence on the template strand (called the forward primer) or the 20 nucleotides preceding the complement of the target sequence on the complementary strand (called the reverse primer). The primers are necessary because DNA polymerase cannot initiate synthesis of a new DNA strand; it can only add nucleotides to a preexisting strand of nucleotides. As a result of complementary base pairing, the primer that resembles the template strand (the forward primer) will bind (anneal) to the complementary strand, while the primer that resembles the complementary strand (the reverse primer) will bind (anneal) to the template strand. Thus, following denaturation, the forward primer anneals to the complementary strand and with elongation by DNA polymerase according to the rules of complementary base pairing, results in a nucleotide sequence identical to the template strand. The reverse primer anneals to the template strand and with elongation, results in a nucleotide sequence identical to the complementary strand. Following renaturation (re-annealing of the two single strands), a double-stranded copy of the original DNA fragment containing the target sequence is produced. The materials needed to carry out PCR include template DNA, DNA polymerase (Taq polymerase), 2 primers- forward and reverse, a mixture of the four deoxyribonucleotides- dATP, dCTP, dGTP and dTTP, MgCl2 (to control the specificity of the amplification), buffer, and H20. This cocktail of ingredients is typically prepared in a microcentrifuge tube and placed in an automated thermal cycler. The thermal cycler brings the temperature to approximately 95 degrees Celsius for 90 seconds for denaturation, 50 to 60 degrees Celsius for two minutes for annealing, and approximately 70 degrees Celsius for three minutes for elongation. This cycle is repeated 20 to 30 times. SEE ALSO: Base Pair; Base Sequence; DNA. Bibliography. Frederick M. Ausubel, et al., eds., Short
Protocols in Molecular Biology, 2nd ed. (Greene Publishing and John Wiley, 1992); Daniel L. Hartl and Elizabeth W.
Jones, eds., Genetics, an Analysis of Genes and Genomes, 5th ed. (Jones and Bartlett, 2001). Noëlle A. Benzekri University of California, Los Angeles
Polymorphism DNA is coded in triplets of bases called codons. A duplication or multiple repeat of nucleotide sequences results in polymorphism, the existence of two or more alleles in a population resulting in frequency of greater than 0.01 frequency of a specific phenotype. Polymorphisms occur in approximately one in 500 nucleotides and must have at least two phenotypes, of which neither is rare. The most common form of polymorphism is ABO blood grouping. Both A type and B type are dominant, and only need to have the alleles from one parent for the type to be expresse. O is recessive, and needs to inherit the O type from both parents. Polymorphisms have been noted in people with sickle-cell anemia and their lowered susceptibility to malaria. Genetic typing can be done with the products of polymerase chain reactions (PCR). A heat stable DNA polymerase replicates a specific portion of the DNA at or around the site known to contain the polymorphism. The closer the nucleotides are to the mutation, the more accurate the test. When the quantity is large enough the sample can be run through gel electrophoresis to determine migration and distinguish markers along the DNA. The association of a specific polymorphism with a specific gene is seen in affected members of a population or family, and a lack of association of these specific sequencing is noted in those who are unaffected. Polymorphism may result in diseases, as with trinucleotide sequences that increase in number, as in the case of the repeat of CGG on the X chromosome. This can cause a form of mental disability called Fragile X, and an unstable trinucleotide CAG repeat on chromosome 4, the dominant inherited gene, causes Huntington’s Chorea. These genetic diseases have no cure, treatment can only treat the manifested symptoms. Other polymorphisms affect the plasma proteins a1-antitrypsin, haptoglobin, transferrin, ceruloplasmin and immunglobulins. These phenotypic varia-
Polymyalgia Rheumatica
tions due to multiple forms of alleles in the genome, are dependant on the location of the base pairs and can affect how the body metabolizes medications and fights infection. Xenobiotics (compounds foreign to the body) are converted to create polar compounds, increasing their water solubility and making them easier for the body to excrete. Approximately 50 percent of drugs ingested are metabolized by a class of enzymes called Cytochrome P450s (CP450s), in a wide range of reactions first through hydroxylation, and then by conjugation or methylation. With polymorphisms, less of the enzyme needed may be available, resulting in an accumulation of the medication in the blood and a variation in drug response. From a global health perspective, research continues on genetic disorders, including polymorphisms and their impact on health disorders and the potential for correction. SEE ALSO: Blood/Blood Transfusion; Gel Electrophore-
sis; Genetic Disorders; Huntington’s Disease; Sickle Cell Anemia.
Bibliography. Maria Almira Correia, Ph.D., “Drug Bio-
transformation”, Basic and Clinical Pharmacology, (Appleton & Lange, 1998); Colin Tudge, The Impact of the Gene From Mendel’s Peas to Designer Babies, (Hill and Wang, 2000); M.A.F. El-Hazmi, “Potential of Molecular Diagnosis for Early Detection of Disability,” www.emro.who.int (cited May 2007). Lyn Michaud Independent Scholar
Polymyalgia Rheumatica Polymyalgia rheumatica is a syndrome that is fairly common in people over the age of 50, with the average age of onset of 70. Out of 100,000 people over the age of 50, approximately 700 will have polymyalgia rheumatica. This syndrome is characterized by morning stiffness or aching in the neck, shoulders, torso, or hips. Along with morning stiffness and aching, an inflammatory process will be detected through a laboratory test called erythrocyte sedimentation rate. This is the same test used to detect the inflammatory
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process in giant cell arteritis, which is often associated with polymyalgia rheumatica. Fifteen percent of patients with polymyalgia rheumatica will develop giant cell arteritis and 50 percent of patients that have giant cell arteritis will develop polymyalgia rheumatica. This association is noteworthy due to the changes that can occur in giant cell arteritis. Giant cell arteritis is a disease that affects the arteries that branch from the carotid artery, which is a major artery supplying blood to the head region. These branches have an inflammatory process that affects the lining of the vessels. One of the primary concerns for giant cell arteritis is the occurrence of irreversible visual loss. Other symptoms include headache, weight loss, fever, fatigue, and double vision. Epidemiology Polymyalgia rheumatica is a syndrome that affects primarily adults over the age of 50. The average age of onset is 70 years old, and tends to affect women twice as often as men. There are differences in the number of new cases each year (annual incidence rates) of polymyalgia rheumatica depending on the geographical region. For example, in the northern regions of Europe, annual incidence rates are 113 per 100,000 per year. In the southern regions of Europe, the annual incidence rates are 13 per 100,000 per year. Pathology/Clinical Findings Before the onset of polymyalgia rheumatica, patients tend to be healthy. When the symptoms begin, it can be a process that develops over weeks to months causing muscle and joint aches of the shoulder girdles, torso, neck, and pelvic girdles. The joint aches are believed to be caused by inflammation of bursa, which functions as cushions around a joint, or the synovium, which is the lining of a joint. Constitutional symptoms may also be present, which consist of feelings of discomfort, anorexia, weight loss, fatigue, and low-grade fever may also accompany the aches. The muscle and joint aches usually affect both sides of the body; however, occasionally they will present on only one side. The aches, if associated with the shoulders or hips, can cause patients to experience trouble with performing activities of daily living. These include tasks such as fixing one’s hair, putting on clothes, cooking, and so forth.
1402 Porphyria The exact cause of polymyalgia rheumatica in unclear at this time. It is believed that there is an immune response in the blood vessels throughout the body. The response then causes specialized cells to produce cytokines (proinflammatory products), which then cause inflammation. However, the production of cytokine cannot be directly linked to the vessel inflammation. Diagnosis The three most agreed-upon diagnostic criteria are as follows: • Patient must be 50 years or older at the onset of disease. • Both sides of the body are aching and have morning stiffness for at least one month in at least two of the following areas: neck or torso, shoulders or upper arms, and hips or thighs. • Erythrocyte sedimentation rate of 40 mm/hour or more. Other criteria for diagnosing include the following: • A rapid response to low-dose corticosteroids (steroids). • An elevated CRP, which is a test that indicates inflammation. • There must be no other disease processes that could cause symptoms, excluding giant cell arteritis. Diagnosis is complex due to the overlap of symptoms and signs with other diseases, such as rheumatoid arthritis. It is associated with an increase in erythrocyte sedimentation rate and usually affects the joints of the hands and feet. They are usually affected on both sides of the body. It does not respond completely to corticosteroid treatment. Hypothyroidism (decreased thyroid hormone production) is another disease that manifests as muscle aches, pain, stiffness, and weakness. Fibromyalgia is a syndrome that should also be considered, usually if the patient is younger than 50, without constitutional symptoms, and has diffuse pain along with focal tender points. Polymyositis is one of the major diseases that can overlap with polymyalgia rheumatica. It is characterized by inflammatory and degenerative changes in muscles of the limb girdle, presenting with weakness, muscle ache, difficulty swallowing, head drop, elevated erythrocyte sedimentation rate, and elevated muscle enzymes. The disease responds well to steroids.
Treatment When patients are thought to have polymyalgia rheumatica, they should be started on low dose of 5 to 20mg of corticosteroids. If polymyalgia rheumatica is the correct diagnosis, the aches and muscle pain will resolve almost immediately. The erythrocyte sedimentation rate and CRP will begin to gradually drop to normal values. Normally, treatment with corticosteroids will take two to three weeks. Once lab values are normalized, the corticosteroid dosage should be tapered. If patients are not responding, an immunosuppressant medication (i.e., methotrexate) may need to be added to the regimen. Prognosis Polymyalgia rheumatica is usually self-limited, lasting months to years, but has not been found to increase the chance of death. SEE ALSO: Arthritis ; Geriatrics; Rheumatoid Arthritis. Bibliography. David B. Hellman and Gene G. Hunder,
“Giant Cell Arteritis and Polymyalgia Rheumatica,”; Gene G. Hunder, “Polymyalgia Rheumatica,” www.uptodate.com (cited May 2007); D. L. Kasper, et al., eds., Harrison’s Manual of Medicine, 16th ed. (McGraw-Hill, 2005). Ahmed S. Samad, M.D. Hoffmann-La Roche Inc.
Porphyria Porphyrias are a group of diseases associated with enzyme deficiencies associated with the production of heme. These diseases may be due to inborn errors of metabolism, environmental toxins of infectious agents. Historically, the porphyrias have been described by distinguishing between hepatic or erythroid forms. Porphyrias can also be divided into acute or cutaneous categories. The acute porphyrias usually cause abdominal pain, neuropathy, autonomic instability, and psychosis. These include aminolevulinic acid dehydratase (ALAD) deficiency and acute intermittent porphyria (AIP). The cutaneous porphyrias are associated with photosensitive lesions of the skin, which include congenital erythropoietic porphyria (CEP),
porphyria cutanea tarda (PCT), and erythropoietic protoporphyria (EPP). A third group of porphyrias have both acute and cutaneous characteristics. These porphyrias are hereditary coproporphyria (HCP) and variegate porphyria (VP). The porphyrias are either autosomal dominant or autosomal recessive. The porphyrias have a storied past throughout history. It is believed that the myths about Dracula stem from individuals with porphyria. Furthermore, one of the most famous cases of suspected porphyria was King George III of England. It is believed that he was a victim of variegate porphyria, from which he suffered abdominal pain, constipation, rashes, confusion, and limb weakness. It has been suggested that his mental and physical impairments may have played a role in Britain losing the American Revolution. Later in history, an epidemic of porphyria cutanea tarda occurred in southeastern Turkey between 1956 and 1961. It is believed that the Turkish government distributed fungicide-containing wheat. This was the first time that acquired porphyrias were associated with environmental toxins in humans. Heme plays a critical role in many physiologic processes. It is essential for binding and transporting oxygen and is involved in the cytochrome P-450 pathway. Furthermore, it is necessary for the production of cyclic guanine monophosphate (cGMP) and regulating hydrogen peroxide. It also is involved in oxidation of tryptophan and prostaglandins. The heme biosynthesis pathway is a process that spans the mitochondria and cytosol of the blood cell. There are eight enzymes in the pathway. Delta-aminolevulinic acid (ALA) synthase is the rate-limiting enzyme. A defect at any point in the cycle may lead to a buildup of neurotoxic metabolites, including aminolevulinic acid (ALA) or porphobilinogen (PBG). These metabolites are thought to cause damage via oxidative stress or chronic renal failure. Nervous system damage may manifest itself as seizures that worsen with typical anticonvulsant medication. The patient may also note abdominal pain and absent peritoneal signs. Other neurologic sequelae include a Guillain-Barré– like syndrome, paresthesias, or weakness. Psychiatric symptoms, such as anxiety, confusion, insomnia, hallucinations, or paranoia, may also occur. The patient may also suffer from bladder dysfunction, tremors, or excessive sweating. Secondary cardiovascular disease or hepatocellular carcinoma is possible as well.
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While the frequency of this set of diseases is currently unknown, there do seem to be certain ethnic groups that have a higher prevalence of particular porphyrias. For example, AIP has been found in individuals of Swedish and Finnish descent at a higher rate. South Africans of Danish descent are known to have a higher rate of VP. In terms of gender frequency, women are more likely to be afflicted with any type of porphyria. Most types of screening tests for porphyrias, except for ALAD deficiency, are aimed at evaluating the levels of PBG using either a Hoesch test or a WatsonSchwartz test. Quantitative urine and stool porphyrin tests may further help to describe a type of porphyria. ALA deficiency may be screened for using an iodinetungsten lamp. Imaging techniques also can play a role in diagnosis. Magnetic resonance imaging (MRI) has been used to study the white matter tracts in patients with porphyria; however, electromyography and nerve conduction studies are less helpful. When treating this disease, the first step is to remove any medications potentially associated with heme biosynthesis dysfunction. The patient is also given carbohydrate-supplemented intravenous fluid. Pain is generally controlled using opiates, while nausea and vomiting can be treated with phenothiazines. If conservative treatment is ineffective after three days, an intravenous heme infusion can be given. In severe cases, a liver transplantation may be necessary if the individual is suffering from AIP. In order to maintain seizure control, magnesium sulfate and diazepam have been used. Correction of electrolyte abnormalities will also help to prevent seizures. In general, the patient should eat foods high in carbohydrates and consistently remain adequately hydrated. SEE ALSO: Epilepsy; Hematology; Liver Transplantation. Bibliography. I. Bylesjo, et al., “Epidemiology and Clini-
cal Characteristics of Seizures in Patients with Acute Intermittent Porphyria,” Epilepsia (v.37/3, 1996); A. Kappas, et al., “The Porphyrias,” in C. R. Scriver, et al., eds., The Metabolic and Molecular Bases of Inherited Disease, 7th ed. (McGraw-Hill, 1995); U. A. Meyer, M. M. Schuurmans, and R. L. Lindberg, “Acute Porphyrias: Pathogenesis of Neurological Manifestations,” Seminars in Liver Disease (v.18/1, 1998); R. A. Norman, “Past and Future: Porphyria and Porphyrins,” Dermatology for the Clinician (v.4/5,
1404 Portugal 2005); S. Sassa, “Diagnosis and Therapy of Acute Intermittent Porphyria,” Blood Reviews (v.10, 1996). Darrin Lee University of California, Irvine
Portugal The Portuguese Republic is the 37th richest nation in the world. Its per capita income of $19,000 is one-third of that of the Big Four Nations. The Portuguese economy is heavily concentrated on services (67.3 percent), and only 10 percent of the workforce is engaged in agriculture. Growth has declined in recent years, and is currently reported at 0.4 percent. Unemployment (7.7 percent) is causing some concern, but inflation (2.3 percent) is well under control. There are great income disparities in Portugal, and the country ranks 38.5 on the Gini Index of Inequality. The richest 10 percent of the population hold 28.4 percent of wealth, but the poorest 10 percent claim only 3.1 percent. According to unofficial estimates, one out of every five Portuguese lives below the poverty line, and 15 percent of the population lives in abject poverty. The health of this group is particularly precarious. The United Nations Development Programme (UNDP) Human Development Reports rank Portugal 37th out of 177 countries on overall qualityof-life issues. The Portuguese government spends 9 percent of the total budget on health. Just under 10 percent of the Gross Domestic Product (GDP) is allocated for health programs, and the government allots $1,791 (international dollars) per capita for health. Almost 70 percent (69.7 percent) of healthcare expenditures are covered by the government, but only 6.5 percent of health funding is used for social security programs. The private sector accounts for 30.3 percent of health expenditures, and 95.70 percent of this spending is derived from out-ofpocket expenses. There are 3.42 physicians, 4.36 nurses, 0.08 midwives, 0.55 dentists, and 0.95 pharmacists per 1,000 population in Portugal. Healthcare in Portugal is provided by three distinct entities. The National Health Service (NHS) offers universal coverage. Many Portuguese are insured by professional health subsystems, which cater to partic-
Portuguese cities are polluted by industrial and vehicle emissions, and coastal areas, such as above, are experiencing water pollution.
ular occupations. Private insurers meet the needs of those not covered by either the NHS or professional health groups. Around a fourth of the population is covered by professional health subsystems, and 10 percent is covered by private insurance companies. All others are insured under the NHS. Implementation of national health policy is the responsibility of five regional health administrations. Taxes from workers and employers provide the basis for NHS funding, while premiums support the other healthcare systems. In Portugal, social insurance is mandatory for workers and the self-employed. Special systems cover miners, longshoremen, railway workers, and merchant seamen. Other people are covered on a voluntary basis. Workers contribute 11 percent of earnings, and self-employed individuals contribute 25.4 percent for mandatory coverage or 32 percent for voluntary coverage. Employers are required to contribute 23.75 percent of payrolls. Social Security provides benefits to the elderly, the disabled, and survivors. Cash benefits are issued for illness and maternity leave. New mothers are guaranteed full salary for six months before and two months after the birth of a child. Fathers may also receive cash
benefits for childbirth and adoption. Either parent may receive cash benefits while on leave to care for an ill child. Grandparents may receive full salary for leave taken during the month after the birth of a child who lives in the same home. Portugal ranks 52nd in life expectancy among nations of the world, and the population of 10,605,870 Portuguese has a life expectancy of 77.7 years. On average, females outlive males by seven years. There is a gap between male (95.5 percent) and female (91.3 percent) literacy. Although all Portuguese of the relevant age groups are enrolled in the primary and secondary school systems, the education system is considered inadequate. This lack of preparation for the workplace has presented major obstacles to Portugal’s economic success. Around 66 percent of Portuguese women use some form of birth control, and Portuguese women give birth at a rate of 1.47 children each. All births are attended by trained professionals, and the adjusted maternal mortality ratio is 5 deaths per 100,000 live births. Portugal has the 26th lowest infant mortality rate in the world. Between 1990 and 2004, infant and under5 mortality were cut drastically, dropping from 11 to 4 deaths per 1,000 live births and from 14 to 5 deaths per 1,000 live births, respectively. Currently, infant mortality occurs at a rate of 4.98 deaths per 1,000 live births. Eight percent of all infants are underweight at birth. Although infant immunization rates for tuberculosis are relatively low (83 percent), other rates are relatively high: diphtheria, pertussis, and tetanus (DPT1), 98 percent; DPT3, polio, measles, and Haemophilus influenzae type B, 95 percent; and hepatitis B, 94 percent. Urban areas are polluted by industrial and vehicle emissions, and coastal areas are experiencing major water pollution. Portugal has a 0.4 percent adult prevalence rate of HIV/AIDS. Some 22,000 people are living with the disease, which has proved fatal to around 1,000 individuals. Health officials are particularly concerned that the number of women diagnosed with HIV/AIDS is on the rise. Human influenza posed major health threats in Portugal in winter 2003 and 2004. The leading cause of death among Portuguese women is cardiovascular disease (44.1 percent compared to 33.3 percent for men). Women are also more likely to be diagnosed with diabetes (58.2 percent compared
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to 41.8 percent) and high blood pressure (63.2 percent to 36.8 percent). Conversely, men are more likely to die from external causes such as car accidents than from disease. SEE ALSO: Healthcare, Europe; Insurance. Bibliography. Central Intelligence Agency, “Portugal,”
World Factbook www.cia.gov/cia/publications/factbook/ geos/po.html (cited April 2007); Commission on the Status of Women, “Portugal,” www.un.org/womenwatch/ daw/Review/responses/PORTUGAL-English.pdf (cited May 2007); Spencer Di Scala, Twentieth Century Europe: Politics, Society, Culture (McGraw-Hill, 2004); Sandra Halperin, War and Social Change in Modern Europe: The Great Transformation Revisited (Cambridge University Press, 2004); Martin A. Levin and Martin Shapiro, eds., Transatlantic Policymaking in an Age of Austerity: Diversity and Drift (Georgetown University Press, 2004); Jeremy Rifkin, The European Dream: How Europe’s Vision of the Future Is Quietly Eclipsing the American Dream (Jeremy P. Tarcher/ Penguin, 2004); Social Security Administration, “Portugal,” www.ssa.gov/policy/docs/progdesc/ssptw/2002-2003/europe/portugal.html (cited May 2007); Social Watch, “Portugal,” www.socialwatch.org/en/fichasPais/171.html (cited May 2007); Peter Taylor-Gooby, New Risks, New Welfare: The Transformation of the European Welfare State (Oxford University Press, 2004); United Nations Children’s Fund, “Portugal,” www.unicef.org/infobycountry/portugal_statistics.html (cited April 2007); World Bank, “Portugal Data Profile,” http://devdata.worldbank.org/external/CPProfile. asp?PTYPE=CP&CCODE=PRT (cited April 2007); World Health Organization, “Highlights on Health in Portugal,” www.who.dk/document/chh/por_highlights.pdf (cited May 2007); World Health Organization, “Portugal,” www. who.int/countries/prt/en/ (cited May 2007). Elizabeth R. Purdy, Ph.D. Independent Scholar
Postpartum Depression In the period immediately following birth, postpartum depression can transform a joyous occasion into one marked by disturbance and despair. The new mother may experience symptoms very similar to the symp-
1406 Postpartum Depression toms of depression: fatigue, trouble sleeping, sadness, anxiety, and/or feelings of guilt or worthlessness. Postpartum depression may go unrecognized because of its similarity to the normal, expected bodily changes after giving birth (e.g., low libido, trouble sleeping). Difference between Postpartum Depression, Blues, and Psychosis Onset and duration distinguish postpartum depression from postpartum blues and postpartum psychosis. Postpartum blues are a temporary condition characterized by mild mood swings, irritability, anxiety, crying spells, loss of appetite, and decreased concentration; these symptoms typically begin within several days after delivery and resolve within two weeks. Postpartum depression can occur any time within one year after giving birth and is severe enough to warrant psychiatric treatment. Postpartum psychosis, the most severe of postpartum disorders, is rare and usually appears within two weeks of childbirth. Its symptoms include thoughts of harming herself or her baby and thereby warrant close medical monitoring. Diagnostic Criteria While the Diagnostic and Statistical Manual of Mental Disorders, 4th edition (DSM-IV), published by the American Psychiatric Association, establishes the diagnostic criteria used by clinicians in diagnosing major depression, postpartum depression is not considered as a separate diagnosis. Attention is paid, however, to the clinical manifestations of postpartum depression that arise within four weeks after childbirth. Epidemiology, Cause, and Clinical Features Postpartum depression is estimated to develop in 10 to 15 percent of women following birth, a rate similar to that of depression reported by women in the general population. However, research has shown that the onset of new cases of depression is higher in the weeks following childbirth than in women who had not just experienced pregnancy. Postpartum depression presents itself clinically by way of changes in sleep, appetite, energy level, digestive function, and sex drive. These indicators should be evaluated within the context of normal expectations and bodily changes during the period following pregnancy. Disturbances in sleep and eat patterns be-
yond what would be expected could be indicative of postpartum depression. In addition, intense anxiety, irritability, guilt, or feelings of inadequacy or failure as a mother are also warning signs of postpartum depression. A perceived inability to bond with the baby may induce great shame and lead the woman to conceal her suffering from family, friends, and her healthcare provider. The combination of genetic predisposition, pregnancy, and the hormonal changes the woman experiences during it may account for the variability in symptoms from woman to woman, though no single hormonal factor (e.g., estrogen, progesterone, testosterone) has been labeled as causative. Prevention and Screening for Postpartum Depression Given the propensity for women who suffer from postpartum depression to conceal feeling of shame or worthlessness associated with the disorder, screening in a clinical care setting becomes an important tool for detection and treatment of postpartum depression. The Edinburgh Postnatal Depression Scale (EPDS) is a self-report questionnaire used by healthcare providers to survey maternal depression that consists of 10 items and has been translated into at least 12 languages. Surveillance of women for postpartum depression is appropriate before discharge and also during pediatric visits in the first 12 months after birth. Screening tools like EPDS are more useful in determining the probability that a woman does not have postpartum depression than predicting that she does. Regardless, healthcare providers are encouraged, at a minimum, to inquire about the mother’s mood and emotional state at both the first and again at the six-month follow-up visits. The “best” form of prevention has yet to be defined, but given that the risk of developing postpartum depression significantly increases in women with a prior history of depression, screening by a provider at an early postpartum visit is particularly useful in detecting signs of postpartum depression. Risk Factors in Postpartum Depression A prior history of depression, including previous postpartum depression, has emerged as a major risk factor for postpartum depression; approximately
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half of all women diagnosed with postpartum depression have an onset of their symptoms before or while pregnant. Other associated risk factors for postpartum depression include young maternal age, unplanned pregnancy, unmarried status, marital conflict (if married), lack of perceived support for pregnancy from family and friends, stressful life events in the year prior to pregnancy, tobacco or illegal drug use during pregnancy, previous miscarriage, high utilization of prenatal care and sick leave during pregnancy, family psychiatric history, personality factors such as neuroticism and introversion, and a personal history of affective disorder. Postpartum depression is the highest in the first six months following the loss of a pregnancy through miscarriage, abortion, or stillbirth, and the risk is higher still for women with a previous history of depression. Outcomes and Treatment Postpartum depression can have a profoundly detrimental effect on the mother–child relationship, both preventing attachment and promoting later behavioral problems. The longer the depression, the more severe and frequent the consequences. A few examples of adverse outcomes of postpartum depression include paternal depression, interference with mother–child bonding, marital relationship stress, and, in extreme cases, suicide and infanticide. Paternal depression further exacerbates the mother’s depression postpartum as well aAlmost 70 percent (69.7 percent) of healthcare expenditures are covered by the governments negatively impacts the marriage and belabors child development. Moreover, research indicates that strain on the mother–child relationship during the critical bonding period after birth negatively affects later development regardless of recovery from postpartum depression. Although suicide and infanticide are more likely to occur in cases of postpartum psychosis than with postpartum depression, severe cases of the latter may incur a risk of suicide just the same. If left untreated, postpartum depression may either improve on its own or may progress into a more severe depressive disorder. Addressing both the biological and social factors contributing to the development of postpartum depression is a common approach to treatment. Phar-
A perceived inability to bond with her baby may induce great shame and lead a woman to conceal her suffering.
macotherapy is a way to address some of the biological factors in postpartum depression; most clinicians recommend treatment of postpartum depression with an antidepressant. Careful attention should be given to the choice of medication. Whether a woman is breast-feeding is an important component of selection criteria as some psychotropic medications may pass into the breast milk. Psychosocial therapy, including interpersonal and cognitive behavioral therapy, addresses many of the social and psychological factors associated with depression such as marital conflict and stress. Additionally, alternative therapies such as light therapy are emerging as effective methods of treating depression. Electroconvulsive therapy is a safe, effective treatment option for women with postpartum depression and is especially recommended for women with severe symptoms of depression, who are suicidal, who are in danger of harming her child, or who are concurrently experiencing psychotic symptoms. Another advantage to this form of therapy is that breast-feeding women are shielded from any adverse effects to or contamination of breast milk.
1408 Prader-Willi Syndrome Research on the effects of hormonal therapy is limited, but improvement of symptoms of postpartum depression has been shown with estrogen therapy. Research on maternal preferences for treatment of postpartum depression has yielded insights into their attitudes toward pharmacological treatment, psychotherapy, and other means of support. In general, women with postpartum depression are reluctant to utilize pharmacological interventions (e.g., antidepressants) out of both fear of addiction and the stigma associated with taking medication. Instead, women preferred to talk about their feelings and symptoms, “talk therapies,” with a sympathetic listener. A common barrier to care is an inability to disclose symptoms of postpartum depression to healthcare professionals due to both reluctance and lack of knowledge about the disorder. SEE ALSO: Breast Feeding; Depression Mental Health;
Psychiatry; Psychotherapy; Suicide.
Bibliography. Cindy-Lee Dennis and Leinic Chung-
Lee, “Postpartum Depression Help—Seeking Barriers and Maternal Treatment Preferences: A Qualitative Systematic Review,” Birth (v.33, 2006); Department of Health and Human Services, “Depression during and after Pregnancy,” http://www.4woman.gov/faq/postpartum.htm (cited February 2007); Shari Lusskin and Shalia Miri, “Postpartum Blues and Depression,” in UpToDate (UpToDate, 2007); M. Steiner, “Postpartum Psychiatric Disorders,” Canadian Journal of Psychiatry (v.35, 1990).
Lareina Nadine La Flair, M.P.H. Harvard University
Prader-Willi Syndrome Prader-Willi syndrome (PWS) is a rare, inherited chromosomal disorder arising from deletion or disruption of genes in the proximal arm of chromosome 15. It was first described in 1956 by Andrea Prader, Heinrich Willi, Alexis Labhart, Andrew Ziegler, and Guido Fanconi of Switzerland. It occurs in 1 of 10,000–16,000 live births. Mothers with prior experience of normal pregnancies report distinctly delayed onset of labor and reduced fetal activity during the pregnancies involving
Prader-Willi children. PWS is characterized at birth by the lack of spontaneous movements, excessive daytime sleepiness perhaps arising from a primary hypothalamic dysfunction, and protective reflexes. Babies display little interest in feeding and their ability to suck is weak or absent. They will take longer to attain the ability to walk, talk, sit, and stand. Children will go on to develop symptoms of muscular hypotonia (weak muscle tone) and asphyxia. Distinctive facial features also identify a child with the syndrome; these include a narrow face, almond-shaped eyes, small-appearing mouth, a thin upper lip with down-turned corners of the mouth, and full cheeks. The child’s eyes may cross (strabismus). A frequent feature generally overlooked is thick saliva at the edges of the mouth. Patients also tend to be relatively insensitive to pain. Between ages 1–6, the child with PWS suddenly develops a tremendous interest in food, and starts overeating (hyperphagia). The brain regions associated with satiety response in those with PWS is delayed and insensitive to food intake. This leads to severe disturbances of appetite regulation, including delayed meal termination and early return of hunger after a meal, leading to abnormal body mass composition and obesity; this in turns leads to increased cardiovascular morbidity and mortality. Unlike individuals with common obesity who have low fasting-plasma ghrelin concentrations, those with PWS have high fasting-ghrelin concentrations that might contribute to their hyperphagia. Ghrelin is an endogenous 28-amino acid ligand in the stomach for the growth hormone (GH) secretagogue receptor; it stimulates appetite and causes obesity in animal models and in humans when given in pharmacological doses. PWS is the most common genetic cause of obesity. Patients also have reduced lean body mass and increased fat mass and GH deficiency. PWS children are generally well behaved; however, they have been known to display spontaneous outbursts of aggressive behavior, and this disorder has also been associated with obsessive-compulsive disorder. Patients may develop symptoms of mental retardation, cognitive deficits, learning problems, and behavioral difficulties. It has been suggested that a contributing factor to the reduced neurocognitive and psychosocial performance is due to the high prevalence of obstructive sleep apnea syndrome in these patients; this is where
Preeclampsia
repetitive upper airways collapse during sleep, resulting in hypoxia and sleep fragmentation. Patients have endocrine problems including reduced or absent secretion of sex hormones (hypogonadism); they have combined hypothalamic (low leutinizing hormone) and peripheral (low inhibin B and high follicle stimulating hormone) hypogonadism, possibly due to a primary defect in sertoli or germ cell maturation or an early germ cell loss. During adolescence, males may have a smaller penis and may have undescended testis. Secondary sexual characteristics such as pubic hair and breast development in females may not develop as well. Growth spurt in patients is also delayed and thus patients tend to have a shorter stature. The majority of chromosomal defects in PWS involve deletion of paternal alleles of imprinted genes from chromosomal region 15q11-13 on the paternal chromosome (a deletion in the maternal chromosome leads to Angelman syndrome). Other defects are due to uniparental disomy (UPD) for maternal chromosome 15 (inheritance of two copies of a chromosome from the mother and no copies from the father, as opposed to the normal one copy from each parent). The genetic alteration leads to dysfunction of several hypothalamic centres and GH deficiency. Other chromosomal aberrations take place which include defects in the SNRPN (small nuclear ribonucleoprotein-associated polypeptide N) gene. PWS is incurable; however, several methods of treatments are available to alleviate the symptoms. GH therapy for short stature improves body composition, linear growth, physical strength, and agility although there have been reports of side effects of scoliosis. Appropriate genetic counseling is given to the parents and dietary management may also be helpful for PWS patients. Treatment with octreotide, a somatostatin agonist, decreases ghrelin concentrations and induces weight loss in children with hypothalamic obesity. Human chorionic gonadotrophin therapy stimulates testosterone production and virilization in patients with hypogonadism. Physical therapy and exercise helps improve strength and coordination. Speech therapy is often beneficial for patients with language problems. As the child grows, eating and weight problems can by controlled through a balanced, low-calorie diet, weight monitoring, external food restriction, and daily exercise. The prognosis for PSW patients is poor; patients are known to have a high mortality rate. Complica-
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tions arising from the disease, such as obesity, may lead to further complications, for example, slipped capital femoral epiphyses and sleep apnea which contributes to morbidity and mortality of PWS. SEE ALSO: Chromosome; Genetic Disorders; Obesity. Bibliography. A. Scheiemann, “Prader-Willi syndrome,”
www.emedicine.com (cited March 2007).
Sarah Boslaugh BJC HealthCare
Preeclampsia Preeclampsia is a serious complication of pregnancy in which the woman develops elevated blood pressure and protein in the urine after the twentieth week of pregnancy. Other signs of preeclampsia include swelling of the hands and face, weight gain of more than two pounds per week, headache, vision problems and stomach pain. The cause of preeclampsia is not known, but genetic, dietary, vascular and autoimmune factors are among those currently being investigated. Higher risk for preeclampsia is associated with African-American race, first pregnancies, multiple pregnancies, older maternal age, and past history of high blood pressure, kidney disease or diabetes. Preeclampsia may develop into eclampsia, also known as toxemia with seizures, which occurs in one out of every 2000 to 3000 pregnancies. The only cure for preeclampsia is to deliver the baby; if the fetus is less than 36 weeks old medical personnel may try to manage the condition until that gestational age is reached to improve the chances of delivering a healthy baby. Women with preeclampsia are usually hospitalized, although cases may also be managed on an outpatient basis. Management of preeclampsia usually includes bed rest and monitoring of blood pressure, protein in the urine and weight. If the mother has severe p;reeclampsia, labor may be induced to deliver the baby earlier than 36 weeks, although the probability of fetal survival is reduced
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Preferred Provider Organization (PPO)
with a shorter gestational period, particularly if the fetus is less than 24 weeks. According to data from the National Hospital Discharge Survey, the average annual incidence of preeclampsia in the United States in the years 19791986 was 26.1 per 1000 deliveries; there was little variation over those years, with the exception that the preeclampsia rate for African American and other minority women was higher in 1979 but decreased from by 1986 until it was approximately that of White women. Women in the age group 30-34 years had the lowest rate (19.8 per 1000 deliveries), while women aged 15-17 years had the highest rate, 50.9 per 1000 deliveries. Unmarried women also had higher rates of preeclampsia, but there were no significant differences by geographic location or type of insurance. The World Health Organization estimates that preeclampsia occurs in in 3.2 percent of live births annually, meaning that there are over 4 million cases worldwide every year. The case fatality rate is estimated at 1.7 percent, resulting in over 63,000 maternal deaths in 2000. As with most maternal risk factors, risk is not evenly distributed but is much more common in developing countries than in industrialized countries. In fact, due to high standards of prenatal care and the availability of medical treatment, in the United States preeclampsia rarely results in maternal death, although fetal and or perinatal death are more common. However, preeclampsia remains the second leading cause of pregnancy-related death in the nited States (in part because pregnancy-related death is rare in the United States) and is the leading cause in many developing countries. The World Health Organization estimates that worldwide, preeclampsia and eclampsia cause 12 percent of all maternal deaths. See Also: Diabetes and Pregnancy; High Blood Pressure;
High Risk Pregnancy; Pregnancy; Premature Babies.
Bibliography. National Library of Medicine, Medical
Encyclopedia: Preeclampsia, www.nlm.nih.gov/medlineplus/ency/article/000898.htm (cited June 2007); Audrey S. Saftlas, et al., From Data to Action: CDC Public Health Surveillance for Women, Infants and Children, (Centers for Disease Control and Prevention, 1995); World Health Or-
ganization, The World Health Report: Make Every Mother and Child Count (WHO, 2005). Sarah Boslaugh BJC HealthCare
Preferred Provider Organization (PPO) Preferred provider organization is a term reserved for one specific model of health insurance run as a managed care organization. Under this model, physicians, hospitals, and other healthcare providers (i.e., dentists, nurses, physical therapists, occupational therapists) have partnered with an insurer or third-party administrator to provide care at low rates to clients who are part of the insurance or administrators network. PPO is one of the main modes of how health insurance can be delivered. The others include health maintenance organizations (HMOs), indemnity insurance, and fee-for-service systems. In the ideal practice, PPOs operate to mutually benefit all parties involved in the health system including the provider, insured patient, and the insurance company or PPO itself. The insurer benefits by being billed at a reduced rate when using providers within the network. The “preferred” or in-network health provider will benefit from an increase in business. The PPO can financially benefit from charging fees to access the use of their network. Mainly, the PPOs are able to deliver reduced rates to their insured patients by negotiating with providers a set fee schedule. In addition, PPOs often can be found contracting with other PPOs to maintain their business position in a specific geographic location. PPOs are unique in their operation when compared to other forms of health insurance delivery. PPOs are different than HMOs in that insured individuals under the PPO plan can be reimbursed, although it is likely to be less, for the use of nonpreferred providers outside of the network. In the case of an HMO, insured individuals receive little to no benefit from their health plan for using healthcare providers who do not participate in the HMO’s plan. Emergency cases tend to be the exception in both cases, however.
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PPOs bring to healthcare several mechanisms to ensure that costs are kept at bay. Utilization review is one feature that allows the insurance company the ability to review medical records of treatments to ensure their providers are providing an appropriate level of care for the insured patients without any excess treatment. While the utilization review often consists of administrators of the insurance company, providers and insured patients often find this additional layer of administration to be troublesome. Another mechanism PPOs employ to reduce costs is the precertification requirement. Under the precertification requirement, all nonemergency hospital admissions or similar care such as outpatient surgery must be approved by the insurer in advance. While PPOs provide one method for delivering care, it also contributes to the complex and highly variable environment of healthcare delivery in the United States. Whether PPOs provide a cost-effective mode of delivering care or add additional layers of paperwork to the process of accessing care remains to be seen. SEE ALSO: Fee for Service; Health Care, U.S. and Canada;
Health Maintenance Organization (HMO); Insurance.
Bibliography. Thomas S. Bodenheimer and Kevin Grum-
bach, Understanding Health Policy (McGraw-Hill, 2002); Cassandra Crawford, Charlene Harrington, and Carroll L. Estes, Health Policy: Crisis and Reform in the U.S. Health Care Delivery System (Jones & Bartlett, 2004); Anthony R. Kovner and Steven Jonas, Jonas & Kovner’s Health Care Delivery in the United States (Springer, 2002). Jonathan Tan, M.P.H. SUNY Stony Brook School of Medicine
Pregnancy Pregnancy is the period of gestation before birth occurs. In human women, that period normally lasts for approximately 40 weeks (280 days). Women of childbearing age are encouraged to have pap smears, vaccinations, basic lab work, and pelvic examinations before becoming pregnant to identify potential problems or preexisting conditions. It is recommended
As a woman’s body prepares for pregnancy, multiple changes occur and hormone levels fluctuate wildly.
that women who are trying to get pregnant begin taking vitamins containing folic acid to reduce risks of birth defects. The first sign of pregnancy is usually a missed menstrual period, and at-home pregnancy testing kits are now available that can detect pregnancies even earlier. Early prenatal care is essential. Toward the end of the pregnancy, examinations may be weekly, or even more frequently in the case of at-risk pregnancies. During the 1920s following the food shortages of World War I, dieting became a common practice in industrialized countries. From then until the 1970s, most physicians limited weight gain during pregnan-
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cy to 15 to 20 pounds. Smoking was touted as a way of gaining weight, and manuals for mothers-to-be insisted that smoking no more than a pack a day of cigarettes was perfectly safe. In 1971, the chairman of the board of Phillip Morris appeared on national television to advise women that smoking would result in smaller babies and make birthing easier. By the 1980s, weight restrictions were relaxed for women who were not overweight at the onset of pregnancy. Normal pregnancy-related weight gains now vary from 25 to 35 pounds. Pregnant women are instructed to eat balanced diets, take vitamins, folic acid, and avoid tobacco and caffeine. Drinking alcohol or taking drugs or herbs not approved by medical providers may result in damage to the fetus. Physical responses As a woman’s body prepares for pregnancy, multiple changes occur and hormone levels fluctuate wildly. As a result, two-thirds of all women experience what is known as “morning sickness,” although it may occur at any time. Morning sickness may involve both nausea and vomiting. In many women, the condition is worse at night when they are tired. In severe cases, a woman may need to be hospitalized. For most women, morning sickness disappears by the 13th or 14th week. Other mothers never experience it at all. Many physicians believe that morning sickness is nature’s way of protecting both mother and child from foodborne illnesses. Several studies have suggested that women who experience morning sickness are significantly less likely than others to miscarry. Healthcare professionals may proscribe medication to alleviate morning sickness. The most common form of self-treatment is eating dry crackers before getting out of bed in the morning and eating small amounts frequently during the day. Other suggested remedies include taking 50 mgs of Vitamin B6 twice a day, using sea sickness bands, pouring cold water over the face and neck, drinking between rather than during meals, and applying light pressure to the accupunctive points located 1-1/2 inches above the inside of the wrist. Japanese women often use umeboshi, a paste used in sushi, which can be eaten on crackers or bread, to ward off morning sickness. Herbal remedies, which should be approved by medical professionals before use, include cardamom seeds and various teas.
Pregnant women experience a good deal of physical discomfort, which accelerates as pregnancy advances. Lower back pain resulting from pressure on the sciatic nerve is common. Mild stretching and exercise, including swimming, may bring some relief. Indigestion and heartburn are also common and may be relieved by antacids, digestive enzymes, and medications. Avoiding caffeine, greasy and spicy foods, citrus fruits, and onions, and never eating late at night may also help. Drinking lots of water may prevent constipation, hemorrhoids, and urinary tract infections that are common during pregnancy. Sleep disturbances and insomnia are frequent complaints because of hormone fluctuations, and they tend to worsen in the final weeks of pregnancy as the infant reaches birthweight and drops into the birthing position. Frequent naps and warm milk may help. Women in the latter stages of pregnancy are advised not to lie on their backs for more than 15 minutes at a time to avoid interfering with blood flow to the uterus. Beyond the normal pains and discomforts of pregnancy, there are warning signs that should not be ignored. Bleeding that is heavier than spotting, a lack of fetal movement for extended periods or at times when the fetus is normally active, severe headaches that may indicate toxemia (pregnancy-related hypertension), severe pain in the abdominal area, and numbness or pain that radiates down the leg require immediate medical attention. By the last quarter of the 20th century, birth control methods had grown more sophisticated and were more widely available than at any time in history. Consequently, birth rates steadily declined. Countries such as Japan, which has a fertility rate of 1.23 children per woman, are now encouraging women to reproduce because of a negative growth rate (-0.088 percent). On the other hand, in Malawi with a per capita income of only $600 a year and a fertility rate of 5.75 children per woman, family planning is encouraged. The world record for the most pregnancies is held by an 18th-century Russian woman who gave birth to 69 babies in the course of 27 pregnancies, producing 16 sets of twins, seven sets of triplets, and four sets of quadruplets. Infections and concerns In industrialized nations, births rarely take place outside the presence of trained medical professional,
and maternal rates are generally low. Medical, nutritional, and sanitation advances have worked together since the early 20th century to slash infant mortality rates. In the poorest developing countries, however, women still experience high fertility rates that contribute to high maternal death rates. Pregnant women in developing countries are also susceptible to a host of infectious diseases as well as to conditions associated with a lack of sustained access to safe drinking water and food and proper sanitation. Access to prenatal and postnatal care may be limited, particularly in rural areas. In Africa, where many of the world’s poorest people reside and where many infectious diseases are endemic, a woman has a one in 20 chance of dying from pregnancy-related causes. By contrast, the risk for women of Northern Europe is one in 10,000. Before the mid-19th century, physicians were responsible for large numbers of deaths that occurred during delivery. In 1847, Ignaz Semmelweis (18181865), a Viennese physician, documented the link between poor medical hygiene and puerperal fever. Since the 1940s, antibiotics and improved sanitary conditions have solved many of the medical conditions historically associated with pregnancy and childbirth. Certain medical conditions occur only during pregnancy, and others are associated with delivery and the post-natal period. Even women who are not diabetic may develop gestational diabetes, which occurs annually in around four percent of all pregnancies in the United States. The exact cause of the condition is unknown, but researchers posit that it develops when hormones required for a healthy pregnancy block the production of insulin in the mother’s body. Blood tests are needed to diagnose the condition, and women who have gestational diabetes are closely monitored and placed on special diets. Pregnant women are highly susceptible to infections such as malaria and puerperal sepsis. Pathogens that may be passed from mother-to-child include primary infections in the blood stream and the placenta such as HIV/AIDS, bacterial infections contracted during delivery, and infections such as hepatitis and E-coli that may be transmitted as the infant passes through the birth canal. Maternal infections may result in deformed fetuses, premature delivery, exacerbation of existing conditions, and the death of the child or mother.
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In cases such as the German measles outbreak of the 1960s when large numbers of fetuses were born with multiple deformities, many mothers elect to have abortions. By the 21st century, 98 percent of the adult population had developed antibodies against the rubella virus, and vaccinations against common childhood diseases such as mumps have virtually eliminated their occurrence during pregnancy. Hepatitis A, a mild form of the Hepatitis virus, is a more common infection, affecting from 10 to 20 percent of the population in North America and Western and Northern Europe. In developing countries of Africa, Asia, and South America, however, 90 percent of the population contracts Hepatitis A, Some countries, including Germany, regularly screen pregnant women for Hepatitis B, which may be transmitted sexually. Studies reveal that 35 percent of infections affecting the fetus develop during the last weeks of pregnancy. The other 65 percent occur during delivery. In countries where access to pre-natal healthcare is widespread, conditions that do exist are diagnosed early and appropriate measures are taken to protect the health of both mother and child. Childbirth Experiences of pregnancy and childbirth have varied across both time and culture. Before the 20th century, women of North America and Europe delivered babies in birthing rooms in their own homes surrounded by females of the community. Among the Micronesian women of the Kapingamarangi atoll, women delivered at the edge of the ocean. In ancient Egypt, separate birthing buildings were erected and decorated with Isis and Pacht, the goddess and god of childbirth. In the antebellum south, slave women delivered in horse stalls, where newborns sometimes developed tetanus from contact with manure. Other women around the world also delivered in stables, where after-birth cleaning was easier. Japanese and Maori women in labor were banned from houses because of the fear of evil spirits, and Chinese women delivered in huts that were burned following birth. By the end of the 20th century, healthier women and improved nutrition resulted in bigger babies than in the past. The average birth weight in industrialized nations is 6.5 to 9 pounds (3 to 4.1 kg), and length varies from 18 to 21” (45.7 to 53.3 cm). Larger babies are not uncommon. According to the Guinness World
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Record, the largest baby on record was born to an Italian mother in 1955 and weighed 22 pounds and eight ounces. In Australia, since 1993, there has been a 12 percent increase in the number of newborns weighing more than 9.9 pounds. In Britain, the number of newborns weighing more than 9 pounds 15 ounces has climbed by 20 percent during the last two decades. Switzerland reports an increase in the number of newborns weighing more than 13 pounds. Increased fetal size means that passage through the birth canal is sometimes difficult. Consequently, the number of cesarean (“C”) sections in which the child is surgically removed from the mother’s womb have become more common. In the 18th and 19th centuries, physicians used a pelvinator that was shaped like giant tweezers to measure the birth canal. By the early 20th century, X-rays were being used with greater accuracy. This practice was discontinued in 1928 when researchers began documenting the adverse effects of X-rays but resumed was the process was improved. In the early 1960s, researchers had linked prenatal Xrays to rising incidences of leukemia. By the end of the 60s, ultrasounds had become standard in large hospitals. Today, they are used around the world, allowing physicians to measure the birth canal, locate the position of a fetus, predict birthweight, observe deformities, and with great accuracy predict the sex of the baby. As a result, physicians are able to determine whether or not a baby will fit through a birth canal. If not, a C-section may be scheduled. C-sections may also be performed to decrease traumas of at-risk pregnancies or prevent the transmission of infections and diseases. The practice of using C-sections for other than medical reasons has come under fire in the 21st century. Throughout most of the world, women of the 21st century deliver their babies in the presence of others. Exceptions to the practice are found only among isolated tribes who adhere to ancient traditions. In Nigeria, for instance, all births after the first occur in solitude. Women of the nomadic Pitjandjara tribe of Australia and the !Kung san tribe of the Kalahari Desert also deliver their own babies. In general, babies are born in hospitals or birthing facilities or in the presence of trained midwives. Night deliveries are common among all animals, and researchers posit that the practice evolved as part of the survival instinct. Human women also tend to go into labor at night, ar-
riving at hospitals at a time when nursing staffs are reduced and the least experienced physicians on duty. According to a 2005 study, at-risk babies born at night have a 16 percent higher chance of dying than babies born between 7 A.M. and 7 P.M. In the 1930s, a number of female physicians and scholars began promoting the practice of natural childbirths as a replacement for births in which mothers were whisked away to be surrounded by “white coats” while fathers cooled their heels in waiting rooms. The first birthing center was established by Ruth Lubic in 1975 in New York City. Within five years, more than 1,000 clinics had been established in the United State. Large numbers of babies are now born in birthing centers, which may stand alone or be associated with large hospitals. Many are located near neonatal units that can transfer at-risk infants immediately so that they receive optimal care from highlytrained medical personnel who have access to stateof-the-art medical technologies. Delivery usually takes place in a friendly and welcoming atmosphere, and fathers are encouraged to participate. Instead of being kept away from parents during the early days in which bonding takes place, most healthy newborns remain in the room with their mothers. Despite early resistance by physicians, birthing centers not associated with hospitals have proved to be quite safe. Participation of fathers in birthing and greater involvement in caring for newborns has given rise to a number of studies on fatherhood. The increase in hormone levels that occur during pregnancy are play essential to preparing the female body for sustaining life and for motherhood. Studies have suggested that levels of prolactin, a hormone associated with lactation, also rises in fathers as birth approaches. Canadian researchers recently found that new and expectant fathers reacted to newborn smells with a rise in both prolactin and cortisol (a stress hormone that appears in mothers) and a drop in testosterone. In a number of experiments, men with the highest levels of these hormones demonstrated the greatest urge to comfort newborns in distress. See Also: AIDS; AIDS and Infection; AIDS and Pregnancy; Alcohol Consumption, Birth Control/Conception; Birth Defects; Birth Rate; Diabetes in Pregnancy; Gastroenterology, Hepatitis; High Blood Pressure in Pregnancy;
Pregnancy and Substance Abuse
Midwife; Smoking in Pregnancy; Vitamin and Mineral Supplements; Women’s Health (General). Bibliography. Tina Cassidy, “Birth: The Surprising His-
tory of How We Are Born,” Atlantic Monthly (2006); George Creatsas, et al., “Women’s Health and Disease: Gynecologic, Endocrine, and Reproductive Issues,” Annals of New York Academy of Sciences (v. 1092, 2006); Editors of Health Magazine, Women Doctors Guide to Health and Healing (Oxmoorhouse, 2003); Jacques Gélis, History of Childbirth, Pregnancy, and Birth in Early Modern Europe (Northeastern University Press, 1991); Clare Hanson, A Cultural History of Pregnancy: Pregnancy, Medicine, And Culture, 1752-2000 (Palgrave, 2004); Sarah Blaffer Hardy and Mary Batten, “The Psychology of Fatherhood,” Time, (18 June 2007); Eiko E. Petersen, Infections in Obstetrics and Gynecology: Textbook and Atlas (Theime, 2006); Roger Segeiken, “Morning Sickness Protects Both Unborn and Mothers-to-Be” www. news.cornell.edu/Chronicle/00/6.8.00/morning_sickness. html (cited June 2007); Edward Shorter, A History of Women’s Bodies (Basic Books, 1982); Meredith F. Small, “Why Do Pregnant Women Get Nauseated Just When Their Bodies Need Most Food? Discover, (September 2000); Helen M. Sterk, et al., Who’s Having This Baby? Perspectives on Birthing (Michigan State University Press, 2002). Elizabeth R. Purdy, Ph.D. Independent Scholar
Pregnancy and Substance Abuse Substance abuse and addiction are illnesses, just like any other, and need to be managed appropriately. This is especially true during pregnancy. During pregnancy, a woman’s body must meet not only her own physiological and metabolic needs, but also those of the fetus developing inside her uterus. They are one system during those 40 weeks of gestation and anything ingested by the mother will be ingested by the developing fetus. This is not only true of the food and nutrients the mother shares with her unborn baby, but also any toxic substances she may come into contact with or choose to use. The effects of substance abuse on the fetus are determined by the components of the substance, the dosage delivered to
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the fetus, and the stage of development of the fetus at the time of exposure. One of the most prevalent types of substance abuse is cigarette smoking during pregnancy. Some research shows as many as 22 percent of expectant mothers are smoking. Besides the obvious health risks to the mother, there are clear links between maternal cigarette smoking and premature births, babies born with low birth weight, and sudden infant death syndrome (SIDS). Nicotine contained in the cigarettes has been show to reduce the maternal blood flow to the uterus and placenta. This is the main mechanism by which damage is done to the fetus, resulting in infants with low birth weight and at increased risk of dying of SIDS before 1 year of age. Research suggests that up to one-sixth of low birth weight births and one-fifth of SIDS deaths could be prevented by maternal smoking cessation. Babies born to mothers who smoke are 2.6 times more likely to die of SIDS before 1 year of age than babies born to mothers who do not smoke, even after holding other variables constant such as socioeconomic status, alcohol use, education level, and household income. Maternal smoking remains the number one modifiable risk factor for SIDS. Alcohol is another substance widely available and abused by pregnant women. The number of women using and/or abusing alcohol during pregnancy is unknown, but in one study of pregnant methamphetamine users, 43 percent of them were also using alcohol. The effects of alcohol on the unborn child have been well studied and have been grouped into the condition named fetal alcohol syndrome. Briefly, this syndrome includes characteristic craniofacial changes and impaired cognitive development. While some in the healthcare field may debate the level of alcohol consumption required to harm the fetus and allow pregnant women to carefully indulge, officially there is no safe level of alcohol use during pregnancy. The use of opioids by pregnant women is associated with increased risk of growth restriction during fetal development, intrauterine fetal demise, and neonates suffering from withdrawal symptoms. The long-term effects on children born to opioid-abusing mothers are unknown or as yet unproven. Marijuana, while a popular recreational drug, is not associated with any known birth defects or specific developmental consequences.
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Cocaine abuse in pregnant women has been linked to several severe problems. Placental abruption, a premature separation of the placenta from the uterine wall can lead to bleeding that can threaten the life of both the mother and the fetus. Preterm premature rupture of membranes is a condition in which the amniotic sac ruptures too soon, exposing the mother and baby to infection and possible premature delivery. Cocaine use in pregnancy has been linked to both of these conditions as well as low birth weight babies, various congenital abnormalities, and neurobehavioral problems. More studies are needed before the long-term effects of cocaine use during pregnancy are well understood. Last, and of increasing prevalence in the United States, is the use of methamphetamines in pregnancy. Pregnant women using methamphetamines are at increased risk of cardiovascular collapse and seizure activity. In a large prospective study of the effects of methamphetamine use during pregnancy, researchers found mothers using methamphetamine were 3.5 times more likely to have small-for-gestational-age (SGA) babies than women who avoided methamphetamine or women who smoked who were two times more likely to have SGA babies than the control group. Methamphetamine use has also been linked to increased risk of premature delivery, placental abruption, fetal distress, cardiac defects, cleft lips, biliary atresia, low birth weight, and decreased head circumference. Even controlling for other variables, methamphetamine-exposed babies have lower birth weights and are more likely to be SGA than their peers. In addition, they can suffer from significant neurodevelopmental delays. Low birth weight infants have a higher childhood morbidity and mortality and are at increased risk for developing noninsulin-dependent diabetes and metabolic syndrome as adults due to stress on underdeveloped pancreatic tissue. Babies with smaller head circumferences have more developmental problems with reading and problem solving. Although more studies are needed to clarify the long-term health consequences for babies born to methamphetamine-using women, current research suggests the early effects are already quite significant. SEE ALSO: Fetal Alcohol Syndrome; Methamphetamine
Abuse; Obstetrics; Obstetrician/Gynecologist; Smoking; Sex-
ual Health; Sexually Transmitted Diseases; Substance Abuse and Mental Health Services Administration (SAMHSA). Bibliography. T. Shah, K. Sullivan, and J. Carter, “Sud-
den Infant Death Syndrome and Reported Maternal Smoking during Pregnancy,” American Journal of Public Health (v.96/10, 2006); L. M. Smith, et al., “The Infant Development, Environment, and Lifestyle Study: Effects of Prenatal Methamphetamine Exposure, Polydrug Exposure, and Poverty on Intrauterine Growth,” Pediatrics (v.118/3, 2006); J. Yankowitz, “Drugs in Pregnancy,” in J. R. Scott, et al., eds., Danforth’s Obstetrics and Gynecology, 9th ed. (Lippincott, Williams, & Wilkins, 2003). Megan K. Guffey, M.D., M.P.H. Independent Scholar
Pregnancy Loss Spontaneous abortion is the involuntary loss of a first trimester pregnancy and typically involves cramping and vaginal bleeding. The cramping is a symptom of cervical dilatation that allows for expulsion of the products of conception through the cervix and out through the vagina. Loss is very common with 15 to 20 percent of all known pregnancies ending in spontaneous abortion. Some sources estimate that the burden of unknown pregnancy loss (meaning women who do not yet know they are pregnant) is actually between two and three times higher. It is important for women experiencing cramping and vaginal bleeding during pregnancy to be seen by a physician right away. She may be experiencing a missed or incomplete abortion where the fetus has died but not all of the uterine contents have been expelled. If this is the case, the woman will need to undergo a procedure known as dilation and curettage to empty the uterus safely. In some situations, it may also be possible to use a medication to dilate the cervix and allow the products of conception to pass without surgical intervention. Over the course of a pregnancy, the risk of fetal loss decreases but never reaches zero. It is possible to lose a pregnancy in the second and third trimesters, but it is much less common. When the fetus is larger, removal from the uterus is more complicated
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of childbearing. After one loss, the chance of another is less than 30 percent with between 80 to 90 percent of women going on to have a successful next pregnancy. Even for women with recurrent pregnancy loss, the chances of a future live birth are 55 to 60 percent. SEE ALSO: Obstetrician/Gynecologist; Obstetrics. Bibliography. D. W. Branch and J. R. Scott, “Early Preg-
nancy Loss,” in J. R. Scott, et al., eds., Danforth’s Obstetrics and Gynecology, 9th ed. (Lippincott, Williams, & Wilkins, 2003); D. C. Boykin and N. Vlahos, “Repeated Pregnancy Loss,” in B. J. Bankowski, et al., eds. The Johns Hopkins Manual of Gynecology and Obstetrics, 2nd ed. (Lippincott, Williams, & Wilkins, 2002). Pregnancy loss, even repeated pregnancy loss, while devastating for some couples, does not signal the end of childbearing ability.
and women may either have to be stimulated to dilate their cervix enough to deliver the dead fetus or undergo a dilation and evacuation where the fetus is removed from the uterus manually by a physician. Many women prefer the second option to avoid the psychological trauma of delivering a dead fetus; however, in many resource-deprived settings, this may not be an option. The most common reason for early term loss is chromosomal anomalies in the developing embryo. In early stages of development, there are numerous rapid cycles of DNA replication and cell division, creating opportunity for error. Or the conceptus may suffer from some intrinsic defect, making it incompatible with life. In other cases, fertilization and cell division may proceed without error, but the embryo is unable to implant successfully into the uterus for continued growth and development. Recurrent pregnancy loss is defined as three or more consecutive losses before 20 weeks gestation. Reasons include structural defects of the uterus, insufficient pregnancy-supporting hormones, parental genetic anomalies, autoimmune disorders, thrombophilias, and premature cervical dilation. In about 50 percent of cases, no cause can be identified. Many of these causes can be treated, so it is important for women to seek counseling and treatment from a physician. Pregnancy loss, even repeated pregnancy loss, while devastating for some couples, does not signal the end
Megan K. Guffey, M.D., M.P.H. Independent Scholar
Premature Babies Preterm birth is defined medically as birth of an infant after viability has been achieved with gestation of at least 20 weeks or birth weight of at least 500 g but before 37 weeks. Most pregnancies last about 40 weeks. About 12 percent of babies in the United States, or one in eight are born prematurely each year. In 2003, more than 490,000 babies in the United States were born prematurely. Worldwide rates of prematurity are more difficult to obtain as the lack of widespread professional obstetric care in developing regions makes determination of gestational age less reliable. The World Health Organization instead tracks rates of low birth weight, which occurred in 16.5 percent of births in less developed regions in 2000. It is estimated that one-third of these low birth-weight deliveries is due to prematurity. Infants born prematurely have an increased risk of death in the first year of life (infant mortality), with most of that occurring in the first month of life (neonatal mortality). Worldwide, prematurity accounts for 10 percent of neonatal mortality, or around 500,000 deaths per year. In the United States, where many of the infectious and other causes of neonatal death have
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been markedly reduced, prematurity is the leading cause of neonatal mortality at 25 percent. The shorter the term of pregnancy, the greater the risks of complications. Prematurely born infants are also at greater risk for developing serious health problems such as cerebral palsy, chronic lung disease, gastrointestinal problems, mental retardation, and vision and hearing loss. Although there are several known risk factors for prematurity, nearly half of all premature births have no known cause. When conditions permit, doctors may attempt to stop premature labor, so that the pregnancy can have a chance to continue to full term, thereby increasing the baby’s chances of health and survival. However, none of these methods have been proven to be too reliable, as in fact, the rate of preterm births in the United States has actually increased 30 percent in the past two decades. Some newer research has identified possible methods to prevent preterm birth, pre-eclampsia/eclampsia, premature rupture of membranes, and preterm labor. This research includes self-care methods to reduce infections, nutritional and psychological interventions, and the control of preterm birth risk factors (e.g., working long hours standing on feet, carbon monoxide exposure, domestic abuse, and other factors). This research is quite new; however, doctors using these newer strategies have obtained preterm birth rates as low as 1 to 2 percent, compared to the 11 to 16 percent currently in the United States. In developed countries, premature infants are usually cared for in a special section of the hospital known as the neonatal intensive care units (NICUs). The physicians who specialize in the care of very sick or premature babies are known as neonatologists. In the NICU, babies are kept in incubators (also called isolettes), which are bassinets enclosed in plastic with climate-control equipment designed to keep babies warm and limit their exposure to germs. Modern neonatal intensive care involves sophisticated measurement of temperature, respiration, cardiac function, oxygenation, and even brain activity. Treatments may include fluids and nutrition through intravenous catheters, oxygen supplementation, mechanical ventilation support, and medications. In developing countries where advanced equipment and even electricity may not be available or reli-
able, simple measures such as kangaroo care (skin-toskin warming), encouraging breast-feeding, and basic infection control measures can significantly reduce preterm morbidity and mortality. SEE ALSO: Association of Women’s Health, Obstetric and
Neonatal Nurses (AWHONN); Breast Feeding; Cerebral Palsy; Infant and Newborn Care; Prenatal Care; Mental Retardation; Neonatology; Neonatologist. Bibliography. March of Dimes, The Growing Problem of
Prematurity (March of Dimes, 2006); J. A. Martin et al., “Births: Final Data for 2004,” National Vital Statistics Reports (v.55/1, 2006); T. J. Mathew and M. F. MacDorman, “Infant Mortality Statistics from the 2003 Period Linked Birth/Infant Death Data Set,” National Vital Statistics Reports (v.54/16, 2006); Mayo Clinic, Premature Birth (Mayo Clinic, 2006). Barkha Gurbani UCLA School Of Medicine
Prenatal Care Prenatal care is the medical care provided for women during pregnancy. Healthcare professionals such as doctors, nurse practitioners or midwifes may offer this care. Prenatal care also educates expectant mothers about healthy self-care practices and provides them with healthcare advice. The purpose of prenatal care is to monitor the progress of the pregnancy and to diagnose potential problems as early as possible. Women who receive prenatal care have healthier babies, and are less likely to have premature deliveries or miscarriages. Prenatal care also decreases the likelihood of other serious complications such as birth defects or maternal death. Newborns that have not received prenatal care are three times more likely to suffer low birth weight and five times more likely to die. It is important that all expectant mothers seek prenatal care because some habits of diet or behavior that are harmless to the mother can be harmful to the development of the fetus. Women should know how to reduce these risks though appropriate prenatal care.
A woman who is planning to get pregnant should make a preconception care appointment to get advice on preparing for pregnancy. Such advice might include taking vitamin supplements or getting any necessary immunizations. As soon as a woman believes she is pregnant, regular prenatal visits should be scheduled. The first prenatal visit usually consists of taking a medical history, running blood and urine tests, and doing a complete physical examination, which normally includes checking blood pressure, performing a pelvic exam and pap test, and recording height and weight. This initial prenatal visit is also a time to answer questions, calculate the baby’s due date, and discuss health and dietary habits. After the first visit, a typical appointment schedule is once a month for the first 6 months, then every two weeks, then weekly during the last month. The later visits to the doctor’s office are often briefer and usually consist of taking measurements such as blood pressure and the fetal heart rate, performing any necessary tests (blood, urine, etc) and making a general assessment.
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Prenatal ultrasound examinations are often performed several times throughout the pregnancy. Ultrasound is a noninvasive technique that provides images of the developing fetus within the mother’s uterus. Ultrasound determines the number of fetuses, monitors fetal growth and placental position, and discovers abnormal conditions or complications. Ultrasound can also detect the sex of the baby. Aside from doctor visits, pregnant women need to pay special attention to their diet and health habits. Expectant mothers should take prenatal vitamins to ensure that they are getting the nutrients they need. However, all medications, including herbs and vitamins, should first be approved by a healthcare professional, because some of these can be harmful to the baby. In general, women should increase their caloric intake by about 300 calories when they become pregnant. Since this is a relatively small amount, it is important that pregnant women consume foods high in nutrients and low in sodium, fat, sugar, caffeine and calories. In particular women should make sure
Aside from doctor visits, pregnant women need to pay special attention to their diet and health habits. Expectant mothers should take prenatal vitamins to ensure that they are getting the nutrients they need.
1420 Prescription Drug Abuse to get enough folic acid, iron, protein, and calcium. Pregnant woman should also remain active for about 30 minutes each day—unless advised otherwise by a healthcare professional. Women should not smoke, drink, or use drugs during pregnancy. Doing so could lead to serious complications and birth defects including sudden infant death syndrome (SIDS) and fetal alcohol syndrome (FAS). Pregnant women should also avoid xrays, hot tubs, and saunas, and chemicals such as solvents, insecticides, mercury and lead because these too can be dangerous for the fetus. In addition to normal prenatal care, doctors may recommend that women take birthing classes and parenting classes to prepare themselves for delivery and their future role as mothers. SEE ALSO: Due Date; Fetal Alcohol Syndrome; Midwife;
Pregnancy; Pregnancy and Substance Abuse; Smoking in Pregnancy; Sudden Infant Death Syndrome (SIDS). BIBLIOGRAPHY. Office on Women’s Health in the De-
partment of Health and Human Services, “Prenatal Care”, www.4woman.gov (cited October 2006); Maternal and Child Health Bureau, “A Healthy Start: Begin Before Baby’s Born”, mchb.hrsa.gov (cited October 2006) Cathleen Clerkin University of California, Berkeley
Prescription Drug Abuse In the United States certain drugs are only available by prescription from a licensed medical doctor. When used in ways other than they are intended, prescribed medications have the potential for abuse. Prescription drug abuse is conceptualized as the non-medical consumption of a prescription drug by an individual for whom it was not prescribed, in order to achieve the feeling or experiences it causes. Misuse and abuse of controlled substances is illegal and poses manifold health problems both for individuals and the collective society. Consumption and abuse of prescription drugs alters brain activity and can lead to such health consequences as drug dependence, overdose, and heart damage and in some cases death.
A Public Health Issue The potential misuse of prescription drugs has long been recognized, with no sectors of society immune from its influence. For example, Opioids and its derivatives have a long history of abuse, dating back to antiquity. Though abuse is not a novel phenomenon, new are the scale, range and growth of the problem. Current estimates indicate that 48 million people, ages 12 and older, (representing 20 percent of United States population) have used prescription drugs for non-medical reasons in their lifetimes. The misuse of prescription drugs, constituting a public health dilemma, is second only to marijuana as the most prevalent drug problem in the United States. Commonly Abused Prescription Drugs While any drug has the potential for abuse, there are certain classes of drugs for which abuse is more prevalent. Opioids, also known as narcotic analgesics such as Oxycodone (OxyCotin), Hydrocodone (Vicodin), Morphine, Codeine, Methadone; Central Nervous System Depressants and barbiturates including Mephobartital, Pentobarbital, Diazepam (Valium), Alprazolam (Xanax), Clonazepam, Lorazepam; and stimulants such as Dextroamphetamine and Methylphenidate (Ritalin) are among the most frequently abused prescription drugs. Current Prevalence of Prescription Drugs Abuse Prescription drug abuse affects numerous people and trends vary substantially within different demographic groups. Notably, non-medical use(s) of prescription drugs are complex and covert disorders thereby complicating the certainly of exact prevalence rates. In the United States, the DEA and the Office of National Drug Control Policy are among those charged with monitoring, assessing the pervasiveness, and tracking the trends regarding the abuse of prescription drugs. According to the 2004 National Survey on Drug Use and Health, an estimated 6.2 million people (2.5 percent of the United States population) 12 years or older had abused prescription medications in the month prior to being surveyed. Several indicators reveal that prescription drug abuse, particularly of opioid pain killers, has increased dramatically over the last decade, with the largest increases occurring among adults 18 to 25 years old. The 2004 National Institute on Drug Abuse’s (NIDA)
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According to the 2004 National Survey on Drug Use and Health, an estimated 6.2 million people (2.5 percent of the United States population) 12 years or older had abused prescription medications in the month prior to being surveyed.
national survey of 8th, 10th, and 12th-graders found that 9.3 percent of 12th-graders reported using Vicodin without a prescription in the past year, and 5 percent reported using OxyContin; making these medications among the most commonly abused prescription drugs by adolescents, as well as adults in the United States. Recent findings indicate that specific age groups, 18-25 year olds, have the highest rates of usage followed by youths 12-17 year olds. In addition, of youth between the ages of 12 and 17 years old, 13.7 percent report having abused prescription drugs at least once in their lifetimes. Federal Regulations All prescription drugs are categorized based on their medical use, abuse and addiction potential, and harmfulness per requirements of the Controlled Substances
Act. Legitimate handlers of these controlled substances, such as hospitals and pharmacies, must register with the Drug Enforcement Administration (DEA) and use their registration numbers to purchase drugs. Drugs with higher abuse potential are subject to tighter restrictions. Those convicted of unlawful manufacturing, distributing, and dispensing of controlled substances face fines, prison sentences, or both. Context International and US federal drug laws embody a dual imperative to ensure the availability of controlled substances for medical purposes, while at the same time, prevent their diversion and abuse. Current trends indicate that the “traditional” opiates, such as opium and heroin, are increasingly sharing the scene with synthetic opioids, diverted from medical sources.
1422 Prevalence There are several factors which contribute to this development. The overuse of psychotropic substances is increasingly becoming a socially acceptable habit, as controlled substances are more readily used and prescribed to treat suffering from either psychological or social problems; loose regulations; unreliable estimates and information; aggressive marketing techniques; and improper or even unethical prescription practices, each augment and enable prescription drug abuse. Amplified accessibility is also a key component. Addiction to prescription drugs is a brain disease that, similar to other chronic diseases that can be treated effectively. Detoxification is a precursor to long-term treatment of addiction but is not itself a treatment. Rather, its principal objective is to relieve withdrawal symptoms while the patient adjusts to being drug free. Prescription drug abuse is primarily treated one of two ways; behaviorally or pharmacologically. Behavioral treatments focus on teaching individuals how to function without relying on drugs whereas pharmacological treatments counter the effects of the drug on the brain and behavior, and can be used to relieve withdrawal symptoms, treat an overdose, or help overcome drug cravings. SEE ALSO: Drug Abuse; Drug Enforcement Administration
(DEA); Drug Industry; Marijuana Abuse; Substance Abuse Mental Health Services Administration (SAMHSA). Bibliography. ONDCP, The President’s National Drug
Control Strategy (The White House, 2004); SAMHSA, Federal Report Shows New Nonmedical Users of Prescription Pain Relievers Outnumbered New Marijuana Users between 2002 and 2004 (USDHHS, 2006). Duane R. Neff Rebekah M Zincavage Brandies University
ber of persons with the diseases or event at a specific point in time, while period prevalence represents the total number of persons who had the diseases during a certain period. Point prevalence answers the questions: how many people currently have the disease? While period prevalence answers: what was the disease burden in a given population at a certain period? You can think of prevalence as a pool or a container where new cases (incidence) are introduced and stays there until death or recovery. Measuring the frequency of diseases or events in a certain population can be conducted using different measurements. Prevalence rate is an important measurement and is calculated by dividing the total number of cases or persons who have the event by the population at risk of having this event. Prevalence rate is obviously a proportion. The formula for calculating prevalence rate is, were K can be 100, 1000, etc”. Sometimes the term prevalence is used instead of prevalence rate. Usually it means point prevalence. An example of determining prevalence: a village of 50 households was selected with a population of 150 people; every household was visited and an interview accompanied with blood tests was conducted; the number of persons with diabetes was 30. The prevalence rate was calculated to be P= (30/150) * 100= 20 percent. SEE ALSO: Epidemiology; Incidence. Bibliography. D. Coggon, et al., Epidemiology for the Un-
initiated (BMJ Publishing Group, 2003); Leon Gordis, Epidemiology (W.B. Saunders Company, 2004); John Last, A Dictionary of Epidemiology (Oxford University Press, 2000). Abdullatif Husseini Birzeit University-Palestine
Preventive Care Prevalence Prevalence represents the total number of existing persons with a disease or event in a defined population at a specific time. Existing cases includes both old and new cases. Point prevalence refers to the total num-
While it is impossible to avoid all illnesses, there are many forms of preventive care that reduce health risks by improving individual health or by checking the spread of germs and infectious diseases. Even simple preventive measures such as frequent hand washing can save lives. The Centers for Disease Con-
trol and Prevention (CDC) in Atlanta suggests that hands should be washed with soap and water for a minimum of 20 seconds before and after preparing food, after going to the bathroom, after changing diapers or cleaning up after children and animals, before and after caring for someone who is sick or who has a cut or wound, after handling uncooked foods, after nose blowing, coughing, and sneezing, and after handling garbage. Alcohol-based sanitizers may be used to kill germs when soap and water are unavailable. Preventive care of children starts even before a woman becomes pregnant. Women who are trying to get pregnant should eat a well-balanced diet, take vitamins that contain folic acid, reduce or eliminate alcohol intake, avoid smoking and nonprescription drugs, drink eight glasses of chemical-free water each day, and avoid all chemicals in food. Infants and children are particularly vulnerable to infectious diseases and accidents. Preventive care for this age group involves proper nutrition and healthcare and never leaving small children unattended (even in high chairs and walkers) removing toxic substances and small and sharp objects from their reach, fitting children with helmets when they ride bicycles and go-carts, and using automobile child restraints that have been properly installed. Children can be protected from drowning deaths by teaching them to swim and never allowing them to be around water unattended. A small child can drown even in a partially filled bathtub or bucket. Other preventive measures involve teaching children to obey established rules such as never talking to strangers, fire prevention, playground safety, and easy-to-understand emergency measures. Exposure to iron and lead-based products may be fatal to children. All firearms should remain under lock and key whenever children are present. In an effort to produce healthier adults, much of the focus of the early 21st century has been on childhood obesity. Children’s advocates and the medical community have long abhorred the practice of encouraging unhealthy eating habits in children through the use of television commercials. In response, companies such as Disney, Kraft, and Kellogg have established new nutritional guidelines to reduce the amount of fat, salt, and sugar in their products and have pledged to pull advertisements for food containing these substances from children’s programs.
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In industrialized nations, the three major causes of death are ischaemic heart disease, which involves reduced blood flow to the heart, cerebrovascular diseases such as stroke, and chronic obstructive pulmonary diseases, including chronic bronchitis and emphysema. All of these result in large part due from lifestyle choices that include poor nutrition, ingestion of harmful substances, and sedentary lifestyles. Although cancers may not always be preventable, early detection is highly correlated to survival rates. For women, preventive healthcare includes regular PAP smears and breast exams, and for men it involves prostate examinations. Controlling hypertension, diabetes, cholesterol levels, and managing stress also significantly cuts the risk of developing other potentially fatal conditions. Cutting out tobacco products is a major factor in preventive healthcare. The CDC reports that cigarette smoking is the leading cause of preventable death in the United States. Smoking kills an estimated 1,200 Americans each day and is responsible for one in every five deaths. Despite this knowledge and a well organized campaign to alert the public to the dangers of smoking, over a fifth of adult Americans continue to smoke. Rates are higher for males (23.9 percent) than for females (18.1 percent). Smoking rates for Whites (21.9 percent) and African-Americans (21.5) are similar, but rates for Hispanics (16.2 percent) and Asians, Native Hawaiians, and Pacific Islanders (13.3) are lower. Smoking is highly related to socioeconomic status, with 32.6 percent of those in the lowest educational groups and 29.9 percent of those below the poverty level smoking. The rate of college-educated Americans who smoke is less than a third of those in lower educational groups. Preventive care also includes avoidance of illegal substances that may lead to diseases such as hepatitis and excessive consumption of alcohol, which is particularly related to diseases of the liver. Individuals who drink and drive are much more likely to be involved in automobile accidents than other drivers. In order to circumvent accidents, some countries have established severe penalties for driving while under the influence. In Britain, for instance, in addition to losing drivers’ licenses for a year, offenders face unlimited fines and possible prison terms. Insurers may raise premiums or refuse to insure repeat offenders. In order to regain a driver’s license, Brits
1424 Preventive Care convicted of driving under the influence may be required to undergo medical exams. Widespread use of alcohol among teenagers is often related to sexual activity. A 2007 study conducted in Britain revealed that young people were three times more likely to have unprotected sex when they were drunk than when they were sober. Among all European nations, Britain reports the highest rate of sexually transmitted diseases (STDs). Consequently, the government has launched a public awareness campaign to encourage teenagers to engage in preventive care by refraining from unprotected sex. In the United States, safe sex campaigns have faced rigorous opposition from the Religious Right and other Conservatives. In developing countries as a whole, HIV/AIDS is the leading cause of death, and illiteracy and low educational levels make public awareness campaigns that encourage safe sex difficult. While other sexually transmitted diseases may not be as lethal as HIV/AIDS, they may cause a range of health problems that range from physical pain and discomfort to infertility to transmission of infections to sexual partners and to offspring during pregnancy and the birthing process. Failure to use birth control is also responsible for high rates of teen pregnancies around the world, and such pregnancies often place both mothers and children at risk. While preventive care in developing countries may be similar in many cases to that practiced in developed nations, residents in these countries are susceptible to many diseases and toxins that are under control or absent in industrialized nations. The leading causes of death in developing countries are HIV/AIDS, lower respiratory infections, ischaemic heart disease, diarrhoeal diseases, cerebrovascular disease, childhood disease, malaria, tuberculosis, chronic pulmonary disease, and measles. In the poorest countries, in rural areas of more affluent developing nations, and in areas where wars and civil strife are common, access to safe drinking water and food and to improved sanitation may be lacking. As a result, these populations suffer from a number of water and foodborne and vectorborne diseases. In war-torn Sudan, for instance, where human rights abuses are receiving worldwide attention, the population has a very high risk of developing food and waterborne diseases such as bacterial and protozoal diarrhea, hepatitis A, typhoid fever, and schistosomiasis. In some areas of the country, the population is at high risk for contracting vectorborne diseases such
as malaria, dengue fever, and African trypanosomiasis (sleeping sickness). Respiratory diseases such as meningococcal meningitis are also common. Adequate access to healthcare is also a major factor in preventive care. However, a large percentage of the world’s population lacks this basic requirement for good health. In the United States, for instance, approximately 14.8 percent of the population, including 9.3 percent of those under the age of 18, has no medical insurance. Access to healthcare varies from state to state, with Michigan having the lowest rate (7.7 percent) and Texas having the highest rate (23.8 percent) of uninsured. Individuals who are uninsured often fail to practice preventive care and may seek medical help only after illnesses have developed. Americans who do have insurance are dependent on administrative decisions from Medicare, Medicaid, and private insurers about what forms of treatment will be covered; and major illnesses may impoverish families when insurance funds are exhausted. Even when healthcare is free, as it is in many developing countries through international and national initiatives, access to medical care may be limited by geography, culture, religion, and ignorance. SEE ALSO: Alcohol Consumption; Birth Defects; Centers for Disease Control and Prevention (CDC); Diabetes; High Blood Pressure; Infant and Toddler Health; Liver Diseases; Medicaid; Medicare; Pregnancy; Obesity; Sexually Transmitted Diseases; Stress; Sudan; United Kingdom. Bibliography. “Adult-Only Froot Loops,” New York Times Online, 16 June 2007; Adrianne Bendich Adrianne and Richard J. Deckelbaum, eds., Preventive Nutrition: The Comprehensive Guide for Health Care Professionals, (Totowa, New Jersey: Humana Press: Humana Press, 2005); CDC, “Smoking and Tobacco Use Fact Sheet” www.cdc. gov/tobacco/data_statistics/Factsheets/adult_cig_smoking.htm (cited August 2007); CIA, “Sudan, World Factbook,” www.cia.gov/library/publications/the-world-factbook/geos/su.html (cited August 2007); Tom Farley and Deborah A. Cohen, Prescription for a Healthy Nation: A New Approach to Improving Our Lives by Fixing our Everyday World, (Boston: Beacon, 2005); Philip J. Hilts, Rx for Survival: Why We Must Rise to the Global Health Challenge, (New York: Penguin, 2005); Alan D. Lopez, Global Burden of Disease and Risk Factors, (New York: Oxford University Press, 2006); Anilk Mandal and N. Stanley Nahman, Jr., eds., Kidney Disease in Primary Care, (Baltimore:
Primary Care
Williams and Wilkins, 1998); John H. Mattox, ed., Obstetrics and Gynecology, (St. Louis: Mosby, 1998); MSNBC, “Substance Abuse Hiking STD Rate in British Kids,” www. msnbc.msn.com/id/19236005 (cited August 2007); The Planned Parenthood Women’s Health Encyclopedia, (New York: Crown, 1996); Jenifer Swanson, Infant and Toddler Health Source Book: Basic Consumer Health Information, (Detroit: Omnigraphics, 2000). Elizabeth R. Purdy, Ph.D. Independent Scholar
Primary Care The definition of “primary care”, as defined by the Institute of Medicine, is “the provision of integrated, accessible healthcare services by clinicians who are accountable for addressing a large majority of personal healthcare needs, developing a sustained partnership with patients, and practicing in the context of family and community.” However, the definition varies slightly by organization. The medical disciplines of family medicine, general pediatrics, and general internal medicine are considered primary care specialties. The discipline of obstetrics and gynecology is also often considered a primary care specialty. Nurse practitioners are also considered primary care providers. The concept of “primary care” was introduced in the 1920s, but gained increasing global popularity in the 1960s and 1970s. During the last decade, the primary care specialties in the United States have seen a decrease in procedural reimbursements, income, and practitioners. However, globally, the availability of primary care has been associated with improved population health outcomes and equity, more appropriate utilization of services, patient satisfaction, and lower costs within health systems. History of Primary Care The term “primary care” was first introduced by Lord Dawson, the chief of the British Army’s medical services, during World War I. The term, describing “primary healthcare centres” within an English National Health Service, was coined in the Dawson Report in 1920. During the 1960s, the concept of primary care became popular in the United States. In 1966,
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three influential groups, the National Commission on Community Health Service, the Citizen’s Commission on Graduate Medical Education, and the Ad Hoc Committee on Education for Family Practice, commissioned reports to examine the role of the generalist physician resulting in white papers by Folsom, Millis and Willard. The specialty of family medicine was also established during this period. In 1978, the specialty of primary care was also recognized in reports from the World Health Organization and from the Institute of Medicine. Declaration of Alma-Ata In 1978, the World Health Organization held an International Conference on Primary Care at AlmaAta. The Declaration of Alma-Ata, resulting from the conference, states, “Primary healthcare is essential healthcare based on practical, scientifically sound and socially acceptable methods and technology made universally accessible to individuals and families in the community through their full participation and at a cost that the community and country can afford to maintain at every stage of their development in the spirit of self-reliance and self-determination. It forms an integral part both of the country’s health system, of which it is the central function and main focus, and of the overall social and economic development of the community. It is the first level of contact of individuals, the family and community with the national health system bringing healthcare as close as possible to where people live and work, and constitutes the first element of a continuing healthcare process.” The key elements of the primary healthcare are, as described by the declaration include global cooperation and peace, a system adapted to the particular circumstances of a country and the communities within it, social and economic development, health promotion and disease prevention strategies, equity in health status, and involvement of all sectors in the promotion of health. The conference participants recognized that primary healthcare must address all causes of poor health including access, cultural, economic, political and social determinants. Institute of Medicine Definition In 1978, the Institute of Medicine defined primary care as “accessible, comprehensive, coordinated and
1426 Proctology continual care delivered by accountable providers of personal health services” in a report entitled “A Manpower Policy for Primary Health Care: Report of a Study”. The terms primary care may be differentiated from the primary healthcare in that primary healthcare includes broader public health measures while primary care focuses on the delivery of personal health services. In 1984, the Institute of Medicine defined community-oriented primary care as, “the provision of primary care services to a defined community, coupled with systematic efforts to identify and address the major health problems of that community through effective modifications in both the primary care services and other appropriate community health programs”. The current definition of primary care, as previously describe, recognizes three attributes of primary care not previously included in the 1978 definition, namely (1) the patient and family, (2) the community, and (3) the integrated delivery system. Availability of Primary Care During the past two decades, reimbursement rates for procedures by primary care clinicians have declined in the United States, resulting in a similar decline in clinician income and availability. Recently, primary medicine specialties, such as family medicine, are having difficulty filling available residency spaces in the United States. Many primary care specialists will not accept patients with Medicare benefits due to low reimbursement rates. Benefits of Primary Care Studies assessing the impact of access to primary carebased health systems found associations with health and economic benefits. Evidence of effectiveness primary care-based health systems includes reduced allcause mortality, less use of emergency departments and hospitals, and better preventive care. Citizens of counties with primary-care based health systems also report fewer use of tests, higher patient satisfaction, less medication use, lower care-related costs and reduced health disparities. SEE ALSO: Institute of Medicine (IOM); World Health Or-
ganization (WHO).
Bibliography. Alma-Ata Declaration 1978, (Interna-
tional Conference on Primary Health Care 1978), Molla S.
Donaldson, Karl D. Yordy, Kathleen, N. Lohr, and Neal A. Vanselow, eds., Primary Care: America’s Health in a New Era (National Academy Press, 1996), Robert L. Phillips and Barbara Starfield, “Why Does a U.S. Primary Care Physician Workforce Crisis Matter?,” American Family Physician (v.70, n. 3, August 1, 2004). Rebecca A. Malouin, Ph.D., M.P.H. Michigan State University
Proctology Proctology is a field of medicine that deals with disorders and diseases that affect the colon, the pelvic floor, the rectum, and the anus. The word derives from the Greek terms proktos, which refers to the anus, and logos for study. Proctologists deal with hemorrhoids and other swellings and inflammation of the veins in the rectum and anus (known as proctitis), unnatural cracks or tears in the anus, fistulas—abnormal connections between the rectum and other anorectal areas to the skin surface, any protrusion of the walls of the rectum into the anus (usually known as rectal prolapse), prolonged constipation, colorectal cancer, anal cancer, or birth defects such as an imperforate anus. Traditionally, the proctoscope was used, but now X-rays and other machinery can also be used. The term proctology is still occasionally used, although proctologists are generally being referred to as colorectal surgeons. Indeed, proctologists are a specialized field of surgeons, and they often work closely with urologists. The American Osteopathic Board of Proctology still certifies osteopathic physicians in the United States, with allopathic physicians being certified by the American Board of Colon and Rectal Surgery. In 1968, the 3rd International Congress of Hedrologicum Conlegium brought together proctologists from all over the world in Nuremberg, Germany. There are two journals devoted to proctology: American Journal of Proctology, Gastroenterology and Colon & Rectal Surgery and American Journal of Proctology, which is the official publication of the International Academy of Proctology, and has been published since 1950.
Prospective Study
SEE ALSO: Colon Polyps; Colonic Diseases (General);
Colorectal Cancer.
Bibliography. American Board of Colon and Rectal Sur-
gery, www.abcrs.org/default.htm; American Osteopathic Board of Proctology, www.aocpr.org/HomePage.html; Giulio Aniello Santoro, Benign Anorectal Diseases: Diagnosis with Endoanal and Endorectal Ultrasound and New Treatment Options (Springer, 2006); Robert Turell, ed., Diseases of the Colon and Anorectum (Saunders, 1969). Justin Corfield Geelong Grammar School, Australia
Programmed Cell Death Programmed cell death, sometimes known as apoptosis, is when an unwanted cell deliberately commits suicide in a multicellular organism. This often comes from the advantages to be obtained from an organism’s life cycle, not as a result of acute tissue injury. In evolutionary terms, it has long been thought that bacteria had been originally incorporated as endosymbionts, living inside larger eukaryotic cells. The theory was championed by Lynn Margulis in 1967 and much of the evidence is based on the fact that mitochondria have their own DNA. There had also been studies of programmed cell deaths in plant tissue, with Jannecke Balk and Christopher J. Leaver of the Department of Plant Sciences at the University of Oxford undertaking research into the mitochondrial genome of the cells of sunflowers; and other work on the programmed cell death in slime mold. It was not long before researchers came to see elements of the work conducted into programmed cell death as being potentially important in medical research into diseases facing humans. From the early 20th century, embryologists had become familiar with the process of programmed cell death with embryos sacrificing some of their cells in order to create what is to be the final form of the organism. In 1972, research by John F. R. Kerr, Andrew H. Wyllie, and Alastair Currie recognized this broader significance in healthcare, and used the term apoptosis, derived from the Greek for “falling off,” in a similar manner to trees shedding their leaves in the fall.
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Their research showed that programmed cell death in humans is a normal physiological process that is used to offset cell proliferation. It can result from both internal and external stimuli, with a cell shriveling and then pulling away from other cells. A formation like a bubble then appears on the surface of the cell, and the chromosomal DNA and protein in the nucleus of the cell condenses. Soon afterward, the cell either breaks into small pieces, is consumed by other cells, or is entirely engulfed by “scavenger cells.” This happens regularly for women during the menstrual cycle with cells lining the uterine wall undergoing “programmed death.” Some of the major work in the field of programmed cell death is in the use of genes to regulate tissue or organ development, and thus, the possible ability of human bodies, after suitable treatment, to program the death of cells that are not healthy, especially those that form cancerous tumors. Furthermore, it is believed that the concept of programmed cell death is how the human immunodeficiency virus (HIV) virus is involved in programming the “deaths” of the healthy white blood cells known as T lymphocytes. The research in the field of gene regulation resulted in the South African-born biologist Sydney Brenner, the British biologist John E. Sulston, and the American biologist H. Robert Horvitz sharing the Nobel Prize for Physiology or Medicine in 2002. SEE ALSO: Chromosome; DNA. Bibliography. W. Bursch, et al., “Programmed Cell Death
(PCD): Apoptosis, Autophagic PCD or Others?” Annals of the New York Academy of Sciences (v.926, 2000); Christian de Duve, “The Birth of Complex Cells,” Scientific American (v.274, 1996); Céline Roisin-Bouffay, et al., “Developmental Cell Death in Dictyostelium Does Not Require Paracaspase,” The Journal of Biological Chemistry (v.279, 2004). Justin Corfield Geelong Grammar School, Australia
Prospective Study Various types of study designs have been described, such as cohort studies, case-control studies, cross-
1428 Prostate Cancer sectional surveys, and randomized clinical trials. A central feature of such designs is whether a study was conducted in a retrospective or prospective manner. For example, case-control studies are generally considered retrospective in nature and cohort studies are typically prospective; however, this may not always be the case. In determining the appropriate study design, many factors are considered and include availability of resources, exposure, outcome/event of interest, sample size, potential confounders and biases, cost, time, and other variables. The general view is that if the phenomena (outcome/event) of interest has already occurred prior to the initiation of the study and various potential confounds may exist that present a challenge to control, the study is regarded retrospective in nature. Conversely, a study is deemed prospective if the study’s subjects or sample group are followed through in time, either randomly or nonrandomly allocated, to assess the development of the outcome/ event. Therefore, prospective studies may account for the temporal sequencing of outcomes/events, and control or minimize confounding variables and biases. However, a prospective study design may be more costly and time consuming in comparison to a retrospective study. In addition, obtaining an adequate sample size is often more challenging in prospective than retrospective studies. Thus, retrospective study designs rely on more historical events and prospective study designs represent outcomes/events that manifest concurrency with the timing of the study. In addition, prospective studies are regarded as being “stronger” or more reliable in design and with a higher level of evidence than are retrospective studies. In lieu of the general views of prospective and retrospective study designs as noted above, classification of studies into such categorizations is, unfortunately, more complex. Various nuances of such study designs may exist. Furthermore, such study designs may often coexist, thereby, studies may utilize both prospective and retrospective components. Overall, the prospective study decreases the risk of bias or recall in respect to the order of the exposure. A retrospective study can influence the analyses and interpretation of the data parameters and affect the study’s validity if one had to rely on infor-
mation already collected and noted, such in the case of clinical chart reviews. In addition, assessment of whether an outcome/event does not influence the exposure may assist in determining if a study design is prospective. SEE ALSO: Double-Blinded Study; Randomized Clinical
Trial; Retrospective Study.
Bibliography. Centre for Evidence Based Medicine, “Lev-
els of Evidence and Grades of Recommendations,” www. cebm.net/levels_of_evidence.asp (cited October 2006); Kenneth J. Rothman and Sander Greenland, Modern Epidemiology, 2nd ed. (Lippincott Williams & Wilkins, 1998).
Dino Samartzis, D.Sc., M.Sc., Dip. EBHC Harvard University and Erasmus University Francis H. Shen, M.D. University of Virginia
Prostate Cancer Prostate cancer is one of the most common cancers of older men, with a median age of onset of 72 years. It is the sixth most common cancer in the world and represents the third most common cause of cancer death in American men. However, because its age of onset is usually so late in life and because a variety of treatment options exist for both localized and advanced disease, many men with prostate cancer ultimately end up dying of other causes. In fact, many believe that if all men lived long enough, they would ultimately develop prostate cancer. The prostate is a male reproductive gland located below the bladder that secretes the liquid components of semen. The prostate is composed mostly of glandular tissue and smooth muscle that contracts to help expel secretions. Prostate cancer is thought to exist along a spectrum of prostate diseases, which begins as a noncancerous enlargement of the prostate gland with age known as benign prostatic hypertrophy (BPH). In fact, age is the strongest risk factor for prostate cancer and prostate cancer onset is more closely correlated with age than any other cancer. Other risk factors for prostate cancer include race and ethnicity. African-American men have both a higher incidence
of prostate cancer and a younger age of onset overall. Genetics seem to play a role in the prostate cancer as well. Men with a first degree relative affected with prostate cancer are at higher risk of getting prostate cancer and this risk increases with the number of affected first-degree relatives. Other risk factors include diet. Research suggests that a diet high in animal fat and low in vegetables, vitamin E, and the metal selenium may predispose men to prostate cancer. There is also evidence to suggest that zinc supplements may increase risk, while the anticholesterol drugs known as statins may decrease risk. Finally, because the prostate gland is a reproductive gland whose growth is dependent on certain male hormones, it has been suggested that men with higher levels of testosterone and insulin-like growth factor are more likely to develop prostate cancer. The presentation of patients with prostate cancer varies widely. Because of the prostate’s proximity to the bladder, some prostate cancers can cause enlargement of the prostate gland and impingement on the portion of the urethra that penetrates the prostate. These patients typically experience difficulty initiating urination, urinary tract infections and/or hematuria, or blood with urination. Because prostate cancer can develop in parts of the gland that do not affect the urethra, many patients can be asymptomatic. However, even silent presentations of prostate cancer can be detected through annual digital rectal exams and prostate-specific antigen (PSA) screening. PSA is a protein that the prostate secretes during periods of inflammation, but it is also elevated in the setting of BPH or prostate cancer. Although elevations in PSA can be very useful in screening for prostate cancer or in suggesting a recurrence, the test is not entirely sensitive or specific. This means that a minority of patients with cancer will not have elevated PSA and that elevations in PSA may not necessarily indicate that a patient has cancer. Some patients may present in advanced stages of prostate cancer where the cancer has spread to distant sites. Because frequent sites of metastasis include the bone and brain, these patients may present with back pain and difficulties walking from metastasis to the vertebrae. Diagnosis of prostate cancer involves pathological examination of a tissue biopsy or specimen. Prognosis is based on the Gleason score, which provides a measure of how aggressive the tumor is. The Glea-
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son score is a score between 1 and 5 which correlates with the degree of differentiation and architecture of the tumor, with a score of 1 correlating with a less aggressive and more differentiated tumor and a score of 5 indicating the tumor is very aggressive and poorly differentiated. Generally, primary tumors that are limited to the prostate have a much better prognosis than lesions that have spread locally or metastasized. Management involves imaging studies, such as bone scans and computed tomography (CT) scans, to determine how advanced the cancer is and obtaining a baseline PSA level to serve as an indicator of future recurrences. Treatment of prostate cancer depends on the degree of spread, Gleason score, and age of the patient at presentation. When the cancer is confined to the prostate gland, median survival is five years, while spread to distant organs usually portends a survival of less than three years. Patients with a very high Gleason score have a worse prognosis as do patients who present at a later age because they are more likely to have other medical conditions which may limit possible treatment options. Another predictor of prognosis is the DNA ploidy, which measures the degree of abnormality of the tumor’s genetic content. Determining DNA ploidy of the tumor involves the use of a particular lab technique known as flow cytometry, which can be difficult to standardize across labs and institutions. This variability can also make interpretation of PSA levels difficult. Treatment of prostate cancer is based primarily on prognosis and age. Because younger men are less likely to have other comorbid illnesses and are also more likely to tolerate aggressive treatment, they are more likely to undergo more aggressive definitive treatment. Definitive treatment for early stage or localized disease usually involves either radical prostatectomy, radiation therapy administered as external beam radiation therapy or brachytherapy, and active surveillance. Radical prostatectomy is usually followed by close observation of the patient’s PSA levels, an increase of which may indicate a recurrence or metastatic disease. However, some patients with early-stage disease may opt to undergo radiation therapy administered as either external beam radiation therapy or brachytherapy, where small radioactive beads are implanted in the prostate to deliver continuous localized radiation. Active surveillance, also known
1430 Prostate Diseases as “watchful waiting,” is a strategy where no clinical interventions are undertaken until the patient’s condition worsens. The patient’s condition is followed closely for a rise in PSA, a change in the digital rectal exam, or detection of a change in the Gleason score of the tumor as measured on biopsies. In patients with more advanced stage and in some older patients who cannot tolerate surgery, androgen deprivation therapy may be considered. Because the prostate is a male reproductive organ, it is highly sensitive to levels of androgens, or male sex hormones, such as testosterone. Because most prostate cancers are also dependent on androgens for continued growth, drugs that counteract the effect of androgens in the body may be helpful. SEE ALSO: American Cancer Society (ACS); Cancer (Gen-
eral); Cancer Alternative Therapy; Cancer Chemotherapy; Cancer—Coping with Cancer.
Bibliography. Marc B. Garnick, “Prostate Cancer: Screen-
ing, Diagnosis, and Management,” Annals of Internal Medicine (v.118/10, 1993); R.F. Gittes, “Carcinoma of the Prostate,” New England Journal of Medicine (v.324/4, 1991).
Jennifer L. Hellawell Cornell University
Prostate Diseases The prostate gland is a solid, walnut-size organ in the male urinogenital system that plays an important part in male sexual function. It is located at the junction of the urinary and reproductive systems. It is also in close proximity to the bowels. Its rear surface can be examined by a physician during a digital rectal exam (DRE). The prostate gland surrounds the first part of the urethra tube and is located under the bladder, in front of the rectum. Its close proximity to the rectal wall poses problems during radiation treatments for prostate cancer. The ancient Egyptians and Greeks were familiar with urinary problems such as bladder and kidney stones. However, the prostate was first described by Niccolo Massa during the Italian Renaissance. The word prostate was coined from a Greek word for “to set before” which was used to describe the prostate’s
location in front of the bladder. The prostate gland is a part of the exocrine system. It secretes fluid from ducts that mixes with sperm immediately before the seminal fluid enters the urethra and is ejaculated during sexual intercourse. As the sperm leave the testicles, the semen passes through ducts in the seminal vesicles. Secretions of the prostate to maintain the vitality of the sperm are then added. The secretions are produced by the epithelial cells that line the microscopic glands and ducts. The prostate adds about ten to thirty percent to the volume of the seminal fluid. The secretions are slightly alkaline. which increases the motility of the sperm. The prostate adds prostate-specific antigen (PSA) to the semen. which liquefies coagulated semen. This reaction frees the sperm to swim on their journey to fertilize the egg. High levels of PSA are normal in semen. However in a blood test, high PSA levels can be used as an indicator of the possibility of prostate cancer. The prostate is small in young boys, weighing only a few grams. It grows with the onset of puberty in response to androgen hormones. It stops enlarging around the age of 20 years. At this time it weighs about 20 grams. The exact reasons for the enlargement of the prostate are not understood. The safest strategy for men is regular examinations to detect any unsual enlargment as early as possible. An infection in the prostate gland can occur in boys or men of any age. The inflammation (prostatitis) may be caused by venereal disease; by the spread of infection from the intestines; or by some non-specific urethritis. Occasionally the infection is due to injury from an examination of the inside of the bladder (cystoscopy). The symptoms of prostatitis are similar to those of an enlarged prostate or to prostate cancer. Difficulty in urinating, painful urination or frequent urination (dysuria) are commonly experienced symptoms in acute cases. Treatment with antibiotics over a long period of time is generally required. Abstinence from sexual activity may be advisable until the infection is cured. Clinically, the fact that the doughnut shaped prostate gland surrounds the small urethra tube is very significant. The prostate in most men begins to enlarge at about the age of fifty. Called prostatic hypertrophy or prostatomegaly, the enlargement is normal. However, it may continue until minor symptoms of prostate enlargement occur (prostatic hypertrophy). This condition does not
need treatment, unless the symptoms become severe or there is prostate cancer. If the enlargement continues it eventually causes painful symptoms, most commonly difficulty in urination. This occurs because as the gland enlarges it squeezes part of the urethra that carries urine from the bladder to the head of the penis during urination. Enlargement of the prostate can contribute to sexual dysfunction, including impotency. The PSA test measures the ratio of PSA in the blood stream to the size of the prostate. For most males the prostate weighs between 20 gram and 100 grams. Therefore a ratio between 2 to 10 on a PSA test is within normal limits. However, the PSA test in not definitive; there are other things that can cause PSA levels to rise besides prostate cancer. PSA can also be deceptive because as prostate cancer spreads the level of PSA production can drop. As the malignant cells mutate and become greater than a 7 on the Gleason grade, they no longer function like normal prostate cells and no longer make PSA. There may be an increasing frequency in the urge to urinate with a feeling that the bladder had not been fully drained. On the other hand there may be an extreme urgency to urinate with some accompanying pain. Blood (hematuria) may also appear in the urine. This is a complication due to bleeding from a dilated vein. Other complications can include the formation of bladder stones (calculi). Additional conditions produced by the enlargement of the prostate include nocturia, which is the need to urinate several times during the night. An enlarged prostate (prostatic hypertrophy) can also block the flow of urine so that urination becomes difficult or impossible. As the condition continues for several weeks (chronic retention) the urine backs up to the kidneys and eventually causes kidney failure (uremia). Retention of urine due to prostate enlargement may occur suddenly or slowly. Sudden, acute retention is usually painful and requires immediate medical attention. Treatment of prostate enlargement is usually by surgical removal (prostatectomy) of the prostate if less radical measures are not effective. It may be necessary to catheterize the patient for several days so that the bladder can drain the urine retained by the blockage. In severe cases treatment for kidney failure may be necessary. It may also be necessary to delay surgery until the general health of the patient improves.
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Cancer of the prostate occurs in older men far more frequently than in younger men. It presents symptoms that are similar to prostate infections or to prostate enlargement. Most prostate cancers arise in the peripheral zone, just below the capsule. If prostatic hypertrophy is caused by cancer the usual treatment is to remove the prostate gland. If the cancer has been caught early enough, the removal of the prostate usually cures the symptoms of enlargement. However, if the cancer has been detected in an elderly man at an advanced stage, treatments with female hormones (estrogen) can usually be effective in reducing the size of the prostate and the development of the cancer. A prostatectomy for cancer may remove the internal urinary sphincter. However, it is important to preserve the external urinary sphincter in order to maintain urinary continence. If prostate cancer has spread, additional tests will be warranted. Unfortuately scans of the prostate, which is a soft tissue organ, are not fully reliable. Bone scans and CT scans are not very helpful in determining if the cancer has spread to the pelvic bone, nor is removal of the pelvic lymph nodes. Usually the age of a man and his remaining life expectancy are factors in deciding between a prostatectomy and other treatments. Benign neglect may be the best strategy in men of advanced age. See Also: Cancer (General); Prostate Cancer; Urologist. Bibliography. Ralph J. Alterowitz, Intimacy with Impo-
tence: The Couple’s Guide to Better Sex after Prostate Disease (Da Capo Press, 2004); Charles B. Inlander and Janet Worsley Norwood, Understanding Prostate Disease (John Wiley & Sons, 1999); Muta M. Issa and Fray F. Marshall, Contemporary Diagnosis and Management of Diseases of the Prostate (Associates in Medical Marketing Company, 2005); Herbert Lepor, ed., Prostate Diseases (Elsevier Health Sciences, 1999); Peter T. Scardion and Judith Kelman, Dr. Peter Scardino’s Prostate Book: The Complete Guide to Overcoming Prostate Cancer, Porstatitis and BPH (Penguin Group, 2006); E. Fuller Torrey, Surviving Prostate Cancer: What You Need to Know to Make Informed Decisions (Yale University Press, 2006); Patrick C. Walsh, Prostate: A Guide for Men and the Women Who Love Them (Grand Central Publishing, 1997). Andrew J. Waskey Dalton State College
1432 Psoriasis
Psoriasis Psoriasis is a very common skin disorder characterized by red lesions that may have silvery scales. Psoriasis is, in many cases, a disorder with a strong genetic predisposition with a severity that is heavily influenced by the environment. There are many types of psoriasis, each with a different physical appearance. It is also associated with human immunodeficiency virus (HIV) and with arthritis, as these diseases sometimes coexist with psoriasis. Treatment options include topical emollients and corticosteroids, ultraviolet light, methotrexate, and drugs that modulate the immune system (immunosuppressive drugs). Epidemiology Rates of psoriasis in the United States tend to be higher in Caucasians than other ethnicities. Furthermore, about 40 percent of psoriatics have a first-degree relative with the disease. In studies of twins, a common method for testing genetic predisposition to diseases, psoriasis is also more prominent among identical twins than fraternal ones. Environmentally, psoriasis tends to be more common among those who smoke tobacco or drink alcohol. Increased levels of stress have also been implicated in severity of the disease. Types of Psoriasis There are four general types of psoriasis: • Plaque psoriasis: Lesions are usually raised from the skin, red, and have distinct borders. Lesions also typically involve extensor surfaces (elbows and shins) as well as the scalp. • Pustular psoriasis: This is the most severe form and is associated with scaling and pustules (bumps on the skin filled with pus). Typically, patients with pustular psoriasis also have abnormalities in liver function. • Inverse psoriasis: Lesions are typically located within intertriginous areas (areas within folds of the skin). This type is not usually associated with scaling. • Nail psoriasis: Typically associated with another form of psoriasis. This type is associated with pitting of the nails, a helpful diagnostic tool for healthcare providers. Nails may also have an
area of tan-brown pigmentation that resembles the color of unused motor oil. Psoriasis and the Connection with HIV and Psoriasis Psoriasis is a disease that in general, tends to be more common in those who have an autoimmune disorder, or a disease in which the body mounts an immune response against itself. Psoriasis is also more common in those who have other diseases that suppress the immune system. Psoriasis in patients afflicted with HIV is particularly severe. There is also a genetic connection, as both diseases are apparently localized to a similar area on a locus of genetic material. Psoriasis is also intimately related to arthritis, as many psoriatics also suffer from arthritis. In short, psoriasis is a disease that is heavily influenced by the integrity of the immune system’s ability to mount an appropriate attack. Treatments Treatment for psoriasis generally depends on the severity of the condition, ranging from topical emollients and creams to systemic agents that alter the immune response. Topical emollients and skin lotions are indicated for mild cases to limit scaling and redness. Topical corticosteroids are effective for plaque psoriasis, with the mode of administration (solution, cream, gel, foam) depending on the affected area. Calcipotriene (Dovonex®) is an agent that limits proliferation of keratinocytes, cells that shed off and contribute to scaling. Methotrexate, a drug that limits cell division in targeted cells, is an old drug that has been used for years, and is useful for cases of psoriatics who also have arthritis. Other immunomodulating drugs, drugs that alter the immune system, are currently being tested, including antineoplastic (anticancer) agents. Discussion Psoriasis is a very common skin disorder, but many patients with psoriasis often suffer from lifestyle impairment. The detrimental effects of the disease, in short, do not seem to be direct effects of the disease but rather of society’s response to the disease. Because psoriatics sometimes have large areas of unsightly lesions on the skin, many patients are reluctant to expose their skin. Patients with psoriasis, in general, also suffer from an increased rate of psychiatric illness and have report
Psychiatry
having a lower rate of social acceptance. It is important that patients with psoriasis lead a balanced and healthy lifestyle, including eating a proper diet, limiting stress, and maintaining an exercise program, as each of these has been shown to modulate the severity of psoriasis. SEE ALSO: Skin Diseases (General). Bibliography. Elliott Douglas Derzaph, Psoriasis: The
Struggle and the Triumph. A Healthy Transformation for Everyone Living with Psoriasis (First Books, 2003); National Psoriasis Foundation, www.psoriasis.org (cited May 2007). Bradley E. Goldstein, M.S., M.P.H. Lake Erie College
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aspects of mental health disorders. A psychiatrist may sub-specialize in a number of areas including adult, child and adolescent, geriatric, addiction, forensic, and emergency psychiatry. Psychiatrists work in a number of settings including hospitals, universities, community health centers, and public and private clinics. SEE ALSO: Mental Health; Psychiatry; Psychologist. Bibliography. Rhoda K. Hahn, M.D., et al., Psychiatry,
(Current Clinical Strategies Pub, 2005); Peter Manu, ed., et al., Handbook of Medicine in Psychiatry (American Psychiatric Publishing, 2006). Claire Nguyen Johns Hopkins Bloomberg School of Public Health
Psychiatrist A psychiatrist is a medical physician that specializes in the prevention, assessment, diagnosis and treatment of mental health disorders. Psychiatrists use the biomedical approach, which emphasizes diagnosis and assessment as the initial phases of the doctor-patient relationship. In this phase, a psychiatrist may employ a number of medical laboratory as well as psychological tests. A psychiatrist will attend to the mental as well as physical aspects of mental health disorders. Psychiatric assessment of a patient involves a diagnostic classification of the disorder and suitable treatment. In North America, the American Psychiatric Association publishes the Diagnostic and Statistical Manual of Mental Disorders (DSM) that provides the standard classification system of mental health disorders. The fourth edition of the DSM is the manual currently in use. The World Health Organization publishes the International Classification of Diseases (ICD-10), which is used throughout much of the rest of the world. Treatment provided by a psychiatrist for mental health disorders may involve physical and psychological interventions, including the provision of medications. At times, in order to provide treatment, a patient may require admission to hospital. The training of a psychiatrist involves successful completion of four years of medical school, followed by a four or five year specialist residency. Residency emphasizes the medical, psychological, as well as social
Psychiatry Psychiatry is the branch of medicine that refers to the prevention, diagnosis, assessment and treatment of mental disorders in people. It comes from the two Greek words which refer to “mind healing,” from the Greek psyche (“soul”) and iatros (“doctor”). It differs from psychology which studies the everyday mental processes in both humans and animals. In the ancient world there were clearly many people who suffered from mental disorders and there are records of physicians in Ancient Egypt and Ancient Greece who tried to explain mental disturbances. Some of their ideas were that people suffering from mental problems had been possessed by demons or other supernatural spirits. The Greeks had stories involving Ajax, when unwell, slaughtering a flock of sheep, and Oestes hallucinating. By contrast Plato (427–347 b.c.e.) felt that mental disorders could be of divine origin. However he gradually came to see that part of the treatment could involve a dialogue with a physician. Building on Plato’s work, Aristotle (384–322 b.c.e.) felt that psychological problems must result from physical ones. Aristotle also claimed that great thinkers had a “melancholic temperament.” Early thinking of people being taken over by spirits, especially evil spirits, led to the proscription
1434 Psychiatry of harsh punishments, with a reference appearing in the Bible: “a man also or a woman that hath familiar spirits, or that is a wizard, shall surely be put to death” (Leviticus xix 31). These ideas were also prevalent in parts of Asia, especially South-east Asia where many folk dances involved trying to hold back the will of spirits which took over humans. The concept of the “shaman” (medicine man) or his equivalent, who can expel these spirits still exists in many parts of the world. However the ideas of the Egyptians and the Greeks were considerably refined in Roman times by Galen of Pergamum (in modern-day Turkey)—Galen was actually Greek, who lived during the height of the Roman Empire. Galen viewed the body as consisting of four main bodily humors: blood, yellow bile, black bile, and phlegm. As a result, Galen saw many problems, including mental ones, as resulting from an imbalance between these as a scientific way of explaining what had previously been seen as supernatural. Throughout the medieval period in Europe, the development of some of the ways of dealing with mental disorders varied from an attempt to explain them scientifically, to spiritual and supernatural explanations which continued to see an interplay of the spirit world with that of the humans. The earliest known hospital wards for people with mental disorders appear to have been in Baghdad (in modern-day Iraq) where the Persian physician Rhazes (865-925) set aside rooms for sufferers to rest and be rehabilitated. A number of purpose-built asylums started appearing in medieval times, with England leading the way. The Bethlehem Royal Hospital (known colloquially as Bedlam) was founded just outside the walls of the City of London in 1247. There were certainly permanent patients at Bedlam in 1403, at which time some asylums were known to exist in Egypt and Spain, a trend gradually spreading to the rest of Europe. To demonstrate the contrary view, mention should also be made of the alchemist and physician Paracelsus (Phillipus Aureolus Theiophratus Bombastus von Hohenheim, 1493–1541) who felt that mental disorders had natural causes, but then urged that insane people should be burned at the stake. During the sixteenth century, the Dutch physician and occultist Johann Weyer (1515/16–1588) put forward the idea that some of the cases which
had resulted in people being convicted of witchcraft were actually connected with mental disorders. He became a critic of the constant accusations of witchcraft made against many people, particularly lonely, elderly women. While Weyer’s ideas became highly influential, they did not stop many more women being executed after being found guilty of witchcraft. Some of the concepts and ideas raised by Weyer led to some physicians and philosophers in the seventeenth century having a greater understanding of neurological problems, with the English physician Thomas Willis (1621–1675) being involved in the study of cranial nerves, and coining the term “neurology.” He wrote Two Discourses Concerning the Soul of Brutus. The next major advance in establishing the discipline of psychiatry was when William Battie (1704–1776) started a detailed study of mental disturbances. His book, A Treatise on Madness, published in 1758 was the first work devoted solely to the treatment of mental illnesses. While earlier asylums had largely been places of confinement, from the late eighteenth century, there was a move in Britain, France, and other countries to provide a more humane and caring approach to patients. This was in contrast to the brutal treatment meted out in Bedlam and other places where fee-paying spectators often visited the asylum. Visits to Bedlam became so common, and the place was so badly run, that the noun “bedlam” is now used to define a chaotic situation. The development of psychiatry as a true scientific discipline can be traced to the work of the French physician Philippe Pinel (1745–1826). A trained doctor, he became, in 1792, the chief physician at Bicêtre, the Paris asylum for men. There his first move was to unchain many of the patients, some of whom had been in chains for up to 40 years. Two years later when he became director of Saltpétrière, the asylum for female inmates, he also unchained the patients urging that the custodial approach to dealing with the problem was unsatisfactory. In addition, the work of J. Connolly in England was also important at this time. Together with Pinel, psychiatrists set about categorizing mental health conditions, viewing disorders as a sickness that required treatment, and therefore the sufferers could be cured. The dedication of the two men led to work in the early nineteenth century in which problems were classified with set methods of treatment. This
in turn led to a move towards treatment of the disorders with a philosophical approach, and interest in psychotherapy which had evolved from new ideas about spiritual healing. At the same time there were a number of ingenious theories with the Austrian physician Franz Anton Mesmer (1734–1815) curing patients with the laying on of hands—Mesmerism, with an English surgeon, James Braid (1795–1860) reworking his method and calling it hypnotism. The German anatomist Franz Josef Gall (1758–1828) developed ideas about craniology, and his ideas became known as phrenology which he felt might have revelations about mental disorders. His ideas were denounced at the time forcing him to move from Austria to France, and have since been dismissed as pseudo-science. With many of the ideas about psychiatry coming from research by Germans, in 1808 the actual term psychiatry was coined in 1808 by Johann Christian Reil. Three years later official teaching of psychiatry began in Leipzig in Saxony, two years before the massive Napoleonic battle was fought outside the city. In the period just before then, in the United States, Benjamin Rush (1746–1813), a physician and a politician, as well as a signatory to the U.S. Declaration of Independence, had published his own ideas about psychiatry. He had worked for many years with inmates at the Pennsylvania Hospital where he had tried to heal mental problems in the same scientific manner that was being applied to physical injuries. Rush also espoused the concept that some insanity came from physical injury or impairment, and his book, Medical Inquiries and Observations upon the Diseases of the Mind, was published in 1812. It was the first American treatise on early psychiatry, and was influential throughout the United States and in many other countries. The next major development was in Germany with another physician, Wilhelm Griesinger (1817– 1868) writing Mental Pathology and Therapeutics in which he noted that the brain was at the center of mental illness, for which he felt that there were many causes. The French psychiatrist Esquirol (1782–1840), who introduced the term “hallucinations,” had long advocated some form of formal training in psychiatry, but it was not until the 1840s that associations were formed. In 1844, the superintendents of asylums
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throughout the United States gathered and agreed to form the Association of Medical Superintendents of American Institutions for the Insane (now known as the American Psychiatric Association). In the following year, in Britain, two acts of Parliament were passed to oversee the management of asylums, and in 1865 the first hospital psychiatric department was established in Berlin. By the late 19th century and the early 20th century, the theories of Sigmund Freud (1856–1939) on psychoanalysis resulted in Freud and his disciples dominating much of the field of research until the mid-twentieth century when behavior therapy and humanistic psychology started to become important. These disciplines seek to pursue the internal conflicts within the minds of patients, as a way of solving some of their outstanding problems. The system of classifying psychiatry patients was formalized by German psychiatrist Emil Kraepelin (1856–1926) who worked on developing a formal method of diagnosis of mental health problems. He observed the condition of thousands of patients which allowed him to draw some overall conclusions in the classification of mental disorders. The Swiss psychiatrist Adolf Meyer (18661950) proved influential during this time, combining biological and psychological approaches to mental disorders. His work was dynamic, viewing that patients became ill as a result of internal factors as well as environmental ones, and thus any attempt to cure people had to be holistic in its approach. Other work during this period was done by Swiss psychiatrist Eugen Bleuler (1857–1940), and German (later East German) doctor Karl Leonhard (1904– 1988). German philosopher and psychiatrist Karl Jaspers (1883–1969), and German psychiatrist Kurt Schneider (1887–1967) both developed a system of diagnosis in psychiatry, with special focus into the form rather than the content as a sign of symptom. Schneider also wrote a diagnosis for schizophrenia. During the twentieth century, asylums were built in many countries where inmates could be held for treatment, and also to prevent them from harming themselves. Most of these catered for civilians, but after World War I with many men suffering from shellshock and other traumas from the war, there were asylums specifically for returned soldiers in many European countries, and also the United States, Canada, Australia and New Zealand.
1436 Psychiatry For the most part the asylums from the early twentieth century would have large grounds where patients could wander, or go for peace and quiet, although histories of some of these institutions indicate clear signs of abuse in many of them, mainly because of the relatively low level of scrutiny to which they were subjected. Although visiting was possible, many of the inmates rarely received visitors. Some of these places experimented extensively with shock therapy, sometimes known as electroshock, or electroconvulsive, therapy, which continues to be used for some cases of severe depression, and also certain forms of psychosis, but is no longer used in the relatively cavalier manner that took place during the 1920s. Most of the asylums had “secure units,” and it was not long before some political regimes abused the system, interfering with psychiatric diagnosis for political control. In Nazi Germany and in the Soviet Union, political opponents could be detained with state doctors claiming that they were suffering from mental disorders. Many people opposed to the Nazi or Soviet regimes would thus be isolated in asylums where they were often held with genuinely psychiatrically disturbed people. A similar system was used, on a lesser level, in the apartheid government in South Africa, when some government leaders have accused their opponents of mental impairment. Certainly in many otherwise relatively benevolent regimes politicians have accused others of suffering from various disorders. As recently as 1992, Crown Prince Tupouto’a of the Pacific island Kingdom of Tonga, the country’s minister of foreign affairs, claimed that some of the democracy activists in the Tongan parliament suffered from a personality disorder, and cited a recent report from the health department. A number of new practices came to be used in psychiatry for the first time in the 1930s. These included the use of ECT, insulin or other drugs, serving as chemical agents, which were able to induce seizures and therefore cut connections between parts of the brain. This developed after World War II, with use, in the 1950s and the 1960s, of chlorpromazine, lithium carbonate, and certain other typical antipsychotic medication. There was also a development in the number of antidepressants and anxiolytic medications which came to be used as forms of psychiatric medication.
During the 1950s and more particularly in the 1960s, stemming from the abuse of psychiatry in Nazi Germany and at that time in the Soviet Union, there was a rise in a movement which attacked psychiatry. During the famous court cases in 1949 surrounding Alger Hiss, a State Department official accused of perjury, psychiatric evidence was permitted in a U.S. court for the first time during the second trial. When a psychiatrist claimed that he had detected that Hiss was paranoid, Claude Cross, representing Hiss highlighted discrepancies in the psychiatrist’s evidence and claimed that psychiatry was an “inexact science.” These attacks mounted, and a number of psychiatrists such as R.D. Laing and Thomas Szasz were involved in offering a detailed critique of mainstream psychiatry. Technology available from the latter part of the twentieth century allowed the use of neuroimaging, with psychiatry moving away from the Freudian and neo-Freudian system of psychoanalysis to a focus on physical medicine, and also neurology. This in turn led to research into whether the causes of mental health problems could be found in the genome, and also whether there could be any indication of problems in the neurochemistry of the brain. This new area of work was known as biopsychiatry, which was contrasted with social psychiatry. The work of Emil Kraepelin was once more used to try to codify problems used in diagnosis. These became known as the “Neo-Kraepelinian” categories, with the International Classification of Diseases and The Diagnostic and Statistical Manual, becoming widely adopted after considerable research undertaken by Robert Spitzer, professor of psychiatry at Columbia University, New York. There were also a number of newly prescribed medicines such as selective serotonin reuptake inhibitor (S.S.R.I.) antidepressants and also a number of atypical antipsychotics. This led to a widening in the field of clinical psychology. During the 1950s there was also a development of psychotropic, or mind-altering, drugs which revolutionized treatment of the mental patient. Some of these led to other unforeseen problems, and it became clear during the 1960s that, as with some other medical techniques, the new drug therapy could be abused by psychiatrists using it for patient “management,” rather than allowing a patient to enhance their outlook and return to the community. The late 20th century saw many people wanting to seek treatment but not keen on taking powerful chem-
ical agents, and once again there was a resurgence in neo-Freudian ideas. It was during this time that American psychiatrist Aaron T. Beck (b. 1921), professor emeritus at the University of Pennsylvania, was involved in developing ideas of cognitive therapy, becoming the president of the Beck Institute for Cognitive Therapy and Research, and the Honorary President of the Academy of Cognitive Therapy. There was also a movement away from the institutional confinement of people in “secure units” and asylums, with many of the asylums in developed countries being closed down, partially for financial reasons – providing a high level of healthcare became far too expensive, and it was no longer possible to run the often impressive (in terms of the buildings) asylums on the small budgets that had previously been allocated to them. The need for fully trained staff to implement the new style of treatment was another problem. Many countries then embarked on a project of locating psychiatric patients with their families, or in small community houses, often “selling” such projects as “returning the patients to the community.” The deinstitutionalization of psychiatric patients has certainly had good results —not just in the lower costs. For many of the patients, it resulted in a far more humane caring environment, and also greater social inclusion. It has certainly helped many to adapt back into society, and has allowed many that suffer from marginal cases of mental disorder to live happy and fulfilling lives. There has also been the introduction of new aspects to psychiatric treatment including psychiatric rehabilitation and Assertive Community Treatment, both seeing the treatment given to a patient as being to help their recovery, rather than using an asylum for, essentially, custodial purposes. The move away from asylums has also had the perhaps unforeseen aim of raising the profile of former patients in society. However it has also led to some social problems with some of the people unable to reintegrate into society and having a greater opportunity to self-harm or harm others. Gradually many of the negative effects have been overcome by advances in psychopharmacology, and a realization that the change in the system from large asylums to small hostels may in fact incur extra costs if it is to be successfully implemented. In order to achieve the much better healthcare for psychiatric patients, there has long been a need to regulate the profession, and this had been the case since
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the nineteenth century in the United States, the United Kingdom, Germany and some other developed countries. The need for regulation is now accepted throughout the world with many psychiatrists combining their psychiatric training with areas such as neurology. In most places, a psychiatrist has also to have obtained a full medical degree before that person embarks on a psychiatric course. In the United States it is compulsory for all psychiatrists to be qualified doctors of medicine or osteopathy, and be certified to treat mental illnesses using the biomedical approach to mental disorders, including the use of medication. Many also undertake extensive training to conduct psychotherapy, such as psychoanalysis or cognitive behavioral therapy. This level of medical training continues to differentiate all psychiatrists from most psychologists and many other mental health professionals. In terms of psychiatry itself, the field is now divided into a number of different specialties. The main divisions are because of the age of the patient, with child and adolescent psychiatry, adult psychiatry and psychogeriatrics (psychiatry of elderly people) being three obvious subspecialties. The people who work in the latter category are known as geriatric psychiatrists in the United States, and as psychogeriatricians in Australia. Other categories include treating people who suffer from a learning disability, the use of behavioral medicine, addiction psychiatry, forensic psychiatry and also emergency psychiatry. There have also been four relatively new fields: Combined Internal Medicine and Psychiatry (Med-Psych); Combined Family Medicine and Psychiatry; Combined Neurology and Psychiatry; and Combined Pediatrics, Psychiatry and Child Psychiatry. There are also fields such as pschyopharmacology, neuropsychiatry, early psychosis and work with eating disorders. With continuing research into psychiatry, there remain four theoretical approaches to psychiatric problems. The first, known as biopsychiatry or neuropsychiatry, heavily focuses on genetics, the neurochemistry of the patient and also the medication they are taking or need to take. The second, social psychiatry, or community psychiatry, is about examining patients in the interpersonal or public health context and involves elements of psychiatric rehabilitation. Freudian and neo-Freudian psychoanalytic psychiatry (sometimes now called dynamic psychiatry) is concerned with applying
1438 Psychiatry concepts and methods from psychoanalysis. The newest field to be delineated, but possibly the oldest in terms of the history of dealing with mental disorders is cross-cultural psychiatry where there is a focus on the relevance of a person’s cultural identity, such as their ethnicity, religious beliefs and also the social environment in which they began to, or continued to suffer from a psychiatric disorder. These branches led to the two main classification systems for mental health conditions. The first, known as the ICD-10 (International Classification of Diseases), was drawn up and published by the World Health Organization (WHO). Although it covers all forms of disease, it does have a detailed section on mental disorders and is consulted around the world. However a more detailed classification, the Diagnostic and Statistical Manual of Mental Disorders (D.S.M.) was produced and issued by the American Psychiatric Association and is used as the main method of classification in the United States. The current edition, published in 2000, is the fourth edition, abbreviated as the DSM-IV-TR. Some other countries have also produced their own diagnostic manuals such as the Chinese Classification of Mental Disorders, published by the Chinese Society of Psychiatry. These manuals serve to standardize diagnosis of problems and symptoms which can be associated with particular disorders. It helps categorize the problems and also ensures that all psychiatrists use the same nomenclature. Essentially the D.S.M. relies on five areas: psychiatric disorders; personality disorders and mental retardation; general medical conditions; social functioning and the impact of symptoms; and global assessment of functioning, which uses a scale from 1 to 1000. The major change in the treatment of psychiatric patients is that nowadays many people are dealt with as outpatients, and hospitalization, if required, is generally for a few weeks, with only a very small number having long-term hospitalization. This is in contrast to most patients staying for long terms in asylums as in the past. Indeed many psychiatric patients come to seek relatively brief counseling as clients, and in the United States many psychiatrists having consulting rooms where people come and explain their problems, and often use psychiatrists as a method for helping unentangle elements of their life and also short periods of depression. This has seen
a proliferation of advertisements in telephone directories in the United States and the like, usually offering psychotherapy services in the section on “psychologists.” The colloquial term for psychiatrist in the United States is a “shrink” from “head shrinker” and can be regarded by psychiatrists as offensive, although it entered common parlance during the 1980s in the United States. The term “alienist” is now no longer used. The use of psychiatrists in this manner has also become more common in other countries, particularly the middle class in Argentina. In many cases the psychiatrist is able to listen, suggest remedies and prescribe some drugs, or suggest that the patient changes their existing medication. Physical examination, running intensive medical tests, the prescription of major drugs, or the use of electroconvulsive therapy are used in more extreme cases. Reference to other health practitioners, law enforcement officials or emergency medical personnel are used as a last resort. See Also: American Academy of Addiction Psychiatry
(AAAP); Child Mental Health; National Institute of Mental Health (NIMH); National Mental Health Association (NMHA); Psychiatrist. Bibliography. Erwin Heinz Ackerknecht. A Short History
of Psychiatry (Hafner Publishing Co., 1968); Sidney Bloch and Bruce S. Singh (eds.), Foundations of Clinical Psychiatry (Melbourne University Press, 2007); Charles Brenner, An Elementary Textbook of Psychoanalysis (Anchor Press, 1974); Peter R. Breggin, Toxic Psychiatry (St. Martin’s Press, 1991); David Brizer, Psychiatry for Beginners (Writers and Readers Publishing Inc., 1993); Nick Crossley, Contesting Psychiatry: Social Movements in Mental Health (Routledge, 2006); Jerome Frank, Persuasion and Healing: A Comparative Study of Psychotherapy (The Johns Hopkins University Press, 1973); Sigmund Freud, The Interpretation of Dreams (Modern Library Press, 1950); Stephen Green and Sidney Bloch, An Anthology of Psychiatric Ethics (Oxford University Press, 2006); C.G. Jung, Modern Man in Search of a Soul (Harcourt, Brace and World, 1934); Thomas S. Szasz, The Myth of Mental Illness: Foundations of a Theory of Personal Conduct (Hoeber-Hoeber, 1961); Sidney Tarachow, An Introduction to Psychotherapy (International Universities Press, 1963); Irvin D. Yalom, The Theory and Practice of Group Psychotherapy (Basic Books, 1975); Gregory Zil-
Psychologist
boorg and George Henry, A History of Medical Psychology (W.W. Norton & Co, 1941). Justin Corfield Geelong Grammar School, Australia
Psychoimmunology The concept of psychoimmunology is based on the connections between the mind and the immune system. At its most basic, it involves the view that the mind and the body are inseparable, and that increased stress affects the body’s ability to resist disease. By contrast, less stress can be seen to make patients stronger. With psychoimmunology, researchers have shown that the brain can influence all types of physiological processes which were once believed not to be centrally regulated. Studies have shown that psychological factors have been able to help with the treatment of many diseases and disorders including diabetes, heart disease, hypertension, inflammatory bowel disease, and rheumatoid arthritis. Essentially, the belief hinges on the fact that if one remains strong in spirit, it will help one deal with medical disorders more effectively. Two of the major pioneers of psychoimmunology are Dr. George L. Engel of the University of Rochester School of Medicine and Dentistry and Dr. George F. Solomon of the Harvard Medical School. Dr. Engel worked heavily on building up what he called the biopsychosocial approach in which he analyzed how physicians approached patients and the various conceptual models that formed. Dr. Solomon, a leading academic psychiatrist, was clinical professor at the Medical School of the University of California, Los Angeles, becoming professor of the Medical School at the University of California, San Francisco, before returning to Los Angeles as professor of psychiatry and behavioral science. He has written over 170 articles on developments in the field of psychoimmunology. SEE ALSO: Psychology; Psychoneuroimmunology. Bibliography. A. Scott Dowling, “Images in Psychiatry:
George Engel, MD (1913–1999),” American Journal of Psychiatry (v.162, 2005); George L. Engel, “The Clinical Ap-
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plication of the Biopsychosocial Model,” American Journal of Psychiatry (v.137, 1980); Jon Alan Kangas and George F. Solomon, The Psychology of Strength (Prentice-Hall, 1975). Justin Corfield Geelong Grammar School, Australia
Psychologist A psychologist is a scientist or clinician who practices in, or studies, the human mind and behavior. Broadly speaking, psychologists are mental health professionals. Psychologists employ their expertise in fields such as health and human services, management, education, law and sports. Clinical psychologists make up the largest proportion of psychologists. These practitioners assist persons with mental or emotional health difficulties, such as persons with a medical or surgical illness or injury, or those experiencing a personal crisis such as divorce or death. Psychologists typically interview patients and administer and interpret diagnostic tests. Based on the assessment, a psychologist will develop and implement a treatment or intervention program. Often, psychologists will work in concert with a healthcare team. Training typically involves the acquisition of a graduate degree. For certain types of practice settings, such as industrial-organizational sites, a Master’s degree is sufficient. However, a doctoral degree is the usual requirement. In North America, the title of psychologist is a protected title. In order to be a psychologist, one must hold a doctoral degree and meet licensing requirements. Only these persons are entitled to perform psychotherapy, a collection of techniques based on communication and dialogue designed to improve the mental health of an individual. Generally, psychologists are not permitted to prescribe medications. Psychologists may specialize in a particular area of interest. Common specialties include health psychology, neuropsychology, and geropsychology. Work settings for psychologists are varied. Some work primarily as researchers or faculty at universities or other research-intensive institutions. Other settings include hospitals, clinics, schools, correctional facilities, and public or private offices.
1440 Psychology SEE ALSO: Mental Health; Psychology. Bibliography. Richard Blonna and Daniel Watter, Health
Counseling: A Microskills Approach (Jones & Bartlett, 2005); Edward P. Sarafino, Health Psychology: Biopsychosocial Interactions (Wiley, 2005).
Claire Nguyen Johns Hopkins Bloomberg School of Public Health
Psychology Soul is regarded as the life-giving entity of living beings and in people. It is viewed as the immortal and spiritual aspects of a person, having no physical or material existence, but accounting for the psychological processes of thinking and willing. In fact, soul is the oldest subject matter of psychology with the very name of the discipline derived from the Greek psyche (also meaning breath and mind) and logos meaning science, study. From the initial search for some essential common basis to all life, Greek scholars eventually postulated the concept of soul, which was systematized in Western thought by Aristotle (384 b.c.e.–322 b.c.e.). This concept was eventually Christianized and emerged intact through Scholasticism to post-Renaissance Europe, at which time, Descartes suggested the mind-body dualism, with psychology as the study of the former and physiology the study of the latter aspects of human experience. The concept of the soul in psychology was not seriously challenged until the 19th and 20th centuries with the rise of materialism in empirical sciences. The Dawn of Scientific Psychology Although were asked in antiquity (e.g., Aristotle’s De Memoria et Reminiscentia, i.e., On Memory and Recollection) and the first person who used this word as a branch of science was Philipp Melanchthon (1497–1560) in his work Commentarius de Anima, i.e., A Commentary on Aristotle’s De Anima, the first person who used to call himself a psychologist was the German philosopher and physiologist Wilhelm Wundt (1832–1920), who founded the first psychological laboratory in Leipzig, Germany, in 1879. That
year is commonly seen as the start of psychology as an independent field of study, because the laboratory conducted exclusively psychological research. Psychology as Science, Arts, and Ideology Today, psychology is defined as the science of behavior and mental processes. As a branch of science, psychology is an academic and applied field involving the study of behavior and its relationship to the mind and brain. Psychologists study an array of problems greater than that of any other scientific discipline. The scope of psychology is an extremely broad field: It encompasses many different approaches to the study of behavior and mind. Important early contributors to the field include German scientist Hermann Ebbinghaus (1850–1909), a pioneer in studies on memory, and Russian physiologist Ivan Pavlov (1849–1936), who discovered the learning process of classical conditioning. Although psychology has been largely concerned with humans, the behavior and mental processes of animals have also been part of psychological research, either as a subject in its own right (e.g., animal cognition) or as a way of gaining an insight into human psychology by means of comparison (Comparative Psychology). As an art, psychology refers to the application of human knowledge to various spheres of human activity, including problems of people’s daily lives (folk psychology) and the treatment of mental illnesses (clinical psychology, psychotherapy, psychiatry). The Austrian neurologist Sigmund Freud’s (1856– 1939) influence on psychology has been enormous, although more as cultural icon than a force in scientific psychology. Freudian psychoanalysis is more arts than science. Freud’s basic theories postulated the existence in humans of various unconscious and instinctive drives, and that the self existed as a perpetual battle between the desires and demands of the internal ego, superego, and id. The 20th century saw a rejection of Freud’s theories among many psychologists as being too unscientific, as well as a reaction against Edward Titchener’s (1867–1927) abstract approach to the mind. This led to the formulation of behaviorism by John B. Watson (1878–1958), which was popularized by B. F. Skinner (1904–1990). Behaviorism proposed epistemologically limiting psychological study to overt behavior because
that could be quantified and easily measured. Scientific knowledge of the mind was considered too metaphysical, hence impossible to achieve. The final decades of the 20th century have seen the rise of a new interdisciplinary approach to studying human psychology, known as cognitive science. Cognitive science again considers the mind as a subject for investigation, using the tools of evolutionary psychology, linguistics, computer science, philosophy, and neurobiology. This new form of investigation has proposed that a wide understanding of the human mind is possible, and that such an understanding may be applied to other research domains, such as artificial intelligence. Psychology can also viewed as an ideology and a part of the history of Western civilization. Psychology represents schools of thought in a certain location during a certain historical period. Various schools of thought have argued for a particular model to be used as a guiding theory by which all, or the majority, of human behavior can be explained. The popularity of these has waxed and waned over time. Some psychologists may think of themselves as adherents to a particular school of thought and reject the others, although most consider each as an approach to understanding the mind, and not necessarily as mutually exclusive theories. Health Perspective, Clinical Psychology, Health Psychology, Psychosomatic Medicine Clinical psychology is the application of psychology to the understanding, treatment, and assessment of psychopathology, behavioral, or mental health issues. It has traditionally been associated with counseling and psychotherapy, although modern clinical psychology may take an eclectic approach, including a number of therapeutic approaches. Typically, although working with many of the same clients as psychiatrists, clinical psychologists do not prescribe psychiatric drugs. Some clinical psychologists may focus on the clinical management of patients with brain injury. This area is known as clinical neurological psychology. In recent years and particularly in the United States, a major split has been developing between academic research psychologists in universities and some branches of clinical psychology. Many academic psychologists believe that these clinicians use therapies based on discredited theories and unsupported
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by empirical evidence of their effectiveness. From the other side, these clinicians believe that the academics are ignoring their experience in dealing with actual patients. The disagreement has resulted in the formation of the American Psychological Society by the research psychologists as a new body distinct from the American Psychological Association. Whereas clinical psychology focuses on mental health and neurological illness, health psychology is concerned with the psychology of a much wider range of health-related behavior including healthy eating, the doctor–patient relationship, a patient’s understanding of health information, and beliefs about illness. Health psychologists may be involved in public health campaigns, examining the impact of illness or health policy on quality of life or in research into the psychological impact of health and social care. Biophysiological Perspective: Brain, Mind, and Behavior Psychology does not necessarily refer to the brain or nervous system and can be framed purely in terms of phenomenological or information processing theories of mind. Increasingly, though, an understanding of brain function is being included in psychological theory and practice, particularly in areas such as artificial intelligence, neurological psychology, and cognitive neuroscience. Since all behavior is rooted in the brain, it is sensible to study how the brain functions in order to understand behavior. This is the approach taken in behavioral neuroscience, cognitive neuroscience, and neurological psychology. Neurological psychology is the branch of psychology that aims to understand how the structure and function of the brain relate to specific psychological processes. Often, psychologists in neuroscience are employed as scientists to advance scientific or medical knowledge. Neurological psychology is particularly concerned with the understanding of brain injury in an attempt to work out normal psychological function. The approach of cognitive neuroscience to studying the link between brain and behavior is to use brain imaging tools. Cognitive Perspective: Information Processing and the Mind The nature of thought is another core interest in psychology. Cognitive psychology is primarily concerned with the process by which perception results in behav-
1442 Psychology ior. Cognitive psychology uses information processing as a framework for understanding the mind. Perception, learning, problem solving, thinking, memory, attention, language, and emotion are all well-researched areas. Cognitive psychology is based on a school of thought known as cognitivism, whose adherents argue for an information processing model of mental function, informed by positivism and experimental psychology. Techniques and models from cognitive psychology are widely applied and form the mainstay of psychological theories in many areas of both research and applied psychology. Cognitive science is very closely related to cognitive psychology but differs in some of the research methods used, and has a slightly greater emphasis on explaining mental phenomena in terms of both behavior and neural processing. Both areas used computational models to simulate phenomena of interest. Because mental events cannot directly be observed, computational models provide a tool for studying the functional organization of the brain and behavior. Such models allow cognitive psychologists to better understand the information processing requirements of behavior and explain hypotheses obtained from behavioral experiments. Developmental Perspective: Change over Time Largely focusing on the development of the human mind through the life span, developmental psychology seeks to understand how people come to perceive, understand, and act within the world and how these perceptions change as we age. This may focus on intellectual, cognitive, neural, social, or moral development. Researchers who study children use a number of unique research methods to engage them in experimental tasks. These tasks often resemble specially designed games and activities that are both enjoyable for the child and scientifically useful. In addition to studying children, developmental psychologists also study other times of rapid change (such as adolescence and old age). Educational Perspective Educational psychology largely seeks to apply much of this knowledge and understand how learning can best take place in educational situations. Because of this, the work of child psychologists such as Lev Vygotsky (1896–1934), Jean Piaget (1896–1980), Lawrence Kohlberg (1927–1987), and Jerome Bruner (1915– )
has been influential in creating teaching methods and educational practices. Interactionist Perspective: Social Psychology, Personality Psychology Social psychology is the study of the nature and causes of human social behavior, with an emphasis on how people think toward each other and how they relate to each other. Social psychology aims to understand how we make sense of social situations. For example, this could involve the influence of others on an individual’s behavior (e.g., conformity or persuasion), the perception and understanding of social cues, or the formation of attitudes and/or stereotypes about other people. Social cognition is a common approach and involves a mostly cognitive and scientific approach to understanding social behavior. Applied Psychology: Industrial and Organizational Psychology, Forensic Psychology The basic premise of applied psychology is the use of psychological principles and theories to overcome practical problems in other fields, such as business management, product design, ergonomics, nutrition, and clinical medicine. Applied psychology includes the areas of industrial/organizational psychology, human factors, forensic psychology as well as many other areas. Industrial and organizational psychology focuses to varying degrees on the psychology of the workforce, customer, and consumer, including issues such as the psychology of recruitment, selecting employees from an applicant pool which overall includes training, performance appraisal, job satisfaction, work behavior, stress at work, and management. Forensic psychology is the area concerned with the application of psychological methods and principles to legal questions and issues. Most typically, this involves a clinical analysis of a particular individual and an assessment of some specific psycholegal question. Forensic psychology refers to any application of psychological principles, methods, or understanding to legal questions or issues. In addition to the applied practices, it also includes academic or empirical research on topics involving law and human behavior. The field of human factors is the study of how cognitive and psychological processes affect our interac-
tion with tools and objects in the environment. The goal of research in human factors is to better design objects by taking into account the limitations and biases of human behavior. Research Methods in Psychology Psychology is conducted both scientifically and nonscientifically but is to a large extent wholly rigorous. Mainstream psychology is based largely on positivism, using quantitative psychological research studies and the scientific method to test and disprove hypotheses, often in an experimental context. Psychology tends to be eclectic, drawing on scientific knowledge from other fields to help explain and understand behavior. However, not all psychological research methods strictly follow the empirical positivism philosophy. Qualitative psychological research utilizes interpretive techniques and is descriptive in nature, enabling the gathering of rich clinical information unattainable by classical experimentation. Some psychologists, particularly adherents to humanistic psychology, may go as far as completely rejecting a scientific approach, viewing psychology more as an art rather than a rigid science. However, mainstream psychology has a bias toward the scientific method, which is reflected in the dominance of cognitivism as the guiding theoretical framework used by most psychologists to understand thought and behavior. The testing of different aspects of psychological function is a significant area of contemporary psychology. Psychometric and statistical methods predominate, including various well-known standardized tests as well as those created ad hoc as the situation or experiment requires. Academic psychologists may focus purely on research and psychological theory, aiming to further psychological understanding in a particular area, while other psychologists may work in applied psychology to deploy such knowledge for immediate and practical benefit. However, these approaches are not mutually exclusive and most psychologists will be involved in both researching and applying psychology at some point during their work. Clinical psychology, among many of the various discipline of psychology, aims at developing in practicing psychologists knowledge of and experience with research and experimental methods which they will continue to build up as well as employ
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as they treat individual with psychological issues or use psychology to help others. Where an area of interest is considered to need specific training and specialist knowledge (especially in applied areas), psychological associations will typically set up a governing body to manage training requirements. Similarly, requirements may be laid down for university degrees in psychology, so that students acquire an adequate knowledge in a number of areas. Additionally, areas of practical psychology, where psychologists offer treatment to others, may require that psychologists be licensed by government regulatory bodies, as well. Controlled Experiment in Experimental Psychology The majority of psychological research is conducted in the laboratory under controlled conditions. This method of research relies completely on the scientific method to determine the basis of behavior. Common measurements of behavior include reaction time and various psychometric measurements. Experiments are conducted to test a particular hypothesis. As an example of a psychological experiment, one may want to test people’s perception of different tones. Specifically, one could ask the following question: Is it easier for people to discriminate one pair of tones from another depending upon their frequency? To answer this, one would want to disprove the hypothesis that all tones are equally discriminable, regardless of their frequency. A task to test this hypothesis would have a participant seated in a room listening to a series of tones. If the participant would make one indication (by pressing a button, for example) if he or she thought the tones were two different sounds, and another indication if he or she thought they were the same sound. The proportion of correct responses would be the measurement used to describe whether all the tones were equally discriminable. The result of this particular experiment would probably indicate better discrimination of certain tones based on the human. Co-relational Studies Co-relational studies use statistics to determine if one variable is likely to co-occur with another variable. For example, one might be interested in whether an individual smokes is correlated with his or her chance of
1444 Psychoneuroimmunology getting lung cancer. One way to answer this would be to simply take a group of people who smoke and measure the proportion of those that get lung cancer within a certain time. In this particular case, one would probably find a high correlation (because tobacco has a deleterious effect on the lungs). However, we cannot know for certain that smoking is the “cause” of lung cancer. It could be that those more prone to cancer are also more likely to take up smoking. A third alternative is that some other variable caused both conditions. This is a major limitation of co-relational studies, and it is exemplified by the fact that co-relation implies causation (logical fallacy). Co-relation does not imply causation. Longitudinal Studies A longitudinal study is a research method that observes a particular population over time. For example, one might wish to study specific language impairment by observing a group of individuals with the condition over a period of time. This method has the advantage of seeing how a condition can affect individuals over long timescales. However, because individual differences between members of the group are not controlled, it may be difficult to draw conclusions about the populations. Compound Research Methods Social psychologists typically use several research methods simultaneously (e.g., lab experiment and interview). In the 1960s, Stanley Milgram (1933– 1984) studied obedience in laboratory. The experimenter told the participants to give increasingly stronger shocks to another person as part of a study on learning. In reality, the experiment had nothing to do with learning; the real issue under consideration was the degree to which participants would comply with the experimenter’s requests and demands. In fact, the “learner” supposedly receiving the shocks was a confederate who never really received any punishment. The results were shocking. Some 65 percent of participants eventually used the highest setting on the shock generator—450 volts— to shock the learner. The participants, who were extensively interviewed after the experiment, said that they obeyed primarily because they believed that the experimenter would be responsible for any potential ill effects that befell the learner.
Neuropsychological Methods and Computational Modeling Computational modeling is a tool often used in cognitive psychology to simulate a particular behavior using a computer. This method has several advantages. Because modern computers are extremely fast, many simulations can be run in a short time, allowing for a great deal of statistical power. Modeling also allows psychologists to visualize hypotheses about the functional organization of mental events that could not be directly observed in a human. Several different types of modeling are used to study behavior. Connectionism uses neural nets to simulate the brain. Another method is symbolic modeling, which represents different mental objects using variables and rules. Other types of modeling include dynamic systems and stochastic modeling. SEE ALSO: American Psychological Association (APA); Psychologist; Psychotherapy. Bibliography. A. L. Blumental, Language and Psychol-
ogy: Historical Aspects of Psychlinguistics (Wiley, 1970); E. G. Boring, A History of Experimental Psychology, 2nd ed. (Prentice Hal, 1950); J. F. Brennan, History and Systems of Psychology (Prentice-Hall, 1982); T. H. Leahey, A History of Modern Psychology (Prentice Hall, 1991). Samvel Jeshmaridian, Ph.D. American Psychological Association
Psychoneuroimmunology Psychoneuroimmunology (PNEI) is a term coined by Robert Ader and Nicholas Cohen at the University of Rochester in 1975 and is a field of research that studies interactions between social psychology, behavior, and the brain with the endocrine and immune systems of the body. This “mind–body” research is expected to play a major role in the fields of cardiology, gastroenterology, gynecology and obstetrics, internal medicine, orthopedics, pediatrics, and psychiatry. The original research by Robert Ader was based on the experiment of the Russian physiologist Ivan Petrovich Pavlov who stimulated dogs to drool by feeding them when he rung a bell, and subsequently
Psychooncology
only ringing the bell. Ader took this experiment further with testing the immune response systems in rats which he found could be conditioned by external stimuli after supplying them with water laced with saccharine and also the drug cytoxan, which induces both nausea and the suppression of the immune system, and then after they became conditions, he used saccharine-laced water alone to get the same immune system response. This led to his major two-volume work, Psychoneuroimmunology, cowritten with David L. Felten and Nicholas Cohen. Felten continued his work at Indiana University School of Medicine, Indianapolis, where he discovered that there was a network of nerves that lead to both the blood vessels and the immune system. Initially, the work on PNEI has resulted in some advances in the treatment of the care-givers for patients suffering from Alzheimer’s disease (who were more likely to develop severe colds, often with an immune system compromised for anything up to two years). It has also helped with the development of medication for treating a range of people who have high stress levels, which has lowered their immune system and, in turn, has made themselves more susceptible to diseases such as the flu. This may affect people who are injured, bereaved, undergoing divorce or unemployment, facing examinations, or generally depressed. SEE ALSO: Psychoimmunology; Psychology. Bibliography. Robert Ader, David L. Felten, and Nicho-
las Cohen, Psychoneuroimmunology, 3rd ed. (Academic Press, 2003); Karl Goodkin and Adriaan P. Visser, eds., Psychoneuroimmunology: Stress, Mental Disorders and Health (American Psychiatric Press, 2000). Justin Corfield Geelong Grammar School, Australia
Psychooncology Psychooncology a subspecialty of oncology that deals with the psychological, social, behavioral, and ethical aspects of cancer. The subject focuses on the emotional dynamics of cancer. It deals with how a patient and
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his or her family respond to cancer and how psychosocial attitudes may influence the disease process. Cancer is a vicious disease. The history of psychooncology goes back to times when cancer was first diagnosed. It was considered heartless to tell the patient of his or her disease diagnosis, while the family was told. Furthermore, investigating the feelings of a patient with cancer was an impossible task due to prevailing conservative attitudes. After World War II, peoples’ attitudes changed and there was a widespread upheaval of human rights, including those of patients’. The legal importance of informed consent from patients could not be overemphasized. However, ever since treatment options improved for patients, better prognosis due to better drugs helped patients share their experiences. Furthermore, groups of treated patients talked to those being treated. This promoted an encouraging environment for counseling of cancer patients. Finally, in 1960s the ice broke, and the idea of “do not tell the patient” was challenged. The patient had a right to know what was wrong with him or her if he or she had cancer. Surveys took place, and after a long debate of oncologists in opposition of the idea, the psychiatrists won. It was unanimously decided that the patient must be told his or her diagnosis. Psychooncology is an area of multidisciplinary interest and has boundaries with the major specialties in oncology. A cancer diagnosis results in a major psychological impact on the patient and his or her family. Reinforcement of a social support system is necessary to help these patients cope with stresses and optimize treatment. The patients often are reported to develop psychiatric disorders, causing suicidal behavior, depression, and anxiety. Furthermore, chemotherapy itself has considerable side effects of nausea, diarrhea, indigestion, idiosyncratic reactions, hair loss, and sterility. Patients must be cooperative during therapy for a better prognosis. The psychiatry department at most hospitals plays a substantial role in dealing with the psychological handling of chronic diseases. Cancer treatment has an integrative approach using an oncologist and a psychiatrist. Counseling, medication management, pain management, and palliative care all are provided by professionals specializing in these areas. Several recent research articles highlight that behavioral abnormalities in cancer patients have more than an emotional reason to them. Significant
1446 Psychotherapy amount of current literature focuses on how cancer progression is associated with neurochemical disorders in the brain. Stress and depression have been associated with increasing tumor frequency. Advanced cancer patients have also been shown to have diminished pineal function. Whether the neurochemical alterations are psychosomatic or vice versa, the psychiatric aspects of this disease are intriguing and pivotal in improving the quality of life of any patient with cancer. SEE ALSO: Cancer; Chemotherapy; Psychiatry. Bibliography. Helen & Harry Gray Cancer Center,
Hartford Hospital, “Psycho-Oncology,” www.harthosp.org/ cancer/psychonc.html (cited February 2007); J. C. Holland, History of Psychooncology: Overcoming Attitudinal and Conceptual Barrier; Pallo Lisuni, “Psychooncology and Cancer Progression Related Alterations of Pleasure Associated Neurochemical System: Abnormal Neuroendocrine Response to Apomorphine in Advanced Cancer Patients,” www.nel.edu (cited June 2007). Quratulain Masood Rizwan Asif Malik Independent Scholar
Psychotherapy Psychotherapy is a general term that describes psychological treatments designed to help people resolve problems and improve the quality of their lives. Psychotherapy involves a person talking to a therapist—psychological professional—about the person’s behavioral, emotional, and interpersonal problems. Psychotherapists employ 400 kinds of therapy for psychological disorders. The primary means of achieving these goals is for a therapist to engage a client in discussions and interactions. The term therapist encompasses a diverse group of people with different backgrounds. Among the most common types of licensed psychotherapists are clinical psychologists, counseling psychologists (or counselors), psychoanalysts, psychiatrists, psychiatric nurses, marriage and family therapists (or family counselors), and social workers. They are also called mental health profes-
sionals. In some countries, there are indigenous therapists and therapies that are being investigated by the Western psychologists. In Western understanding, the treatment of psychological disorders can be divided into two broad categories: biomedical therapies (that uses biological methods of treatment) and psychological therapies (the kind of therapy that involves talking out things with a professional). Biomedical therapies try to bring symptoms under control by using psychotropic drugs, electroconvulsive therapy, and psychosurgery, which alter the central nervous system’s functioning and reduce symptoms. Antidepressant drugs are used in the treatment of depression and include monamine oxidase inhibitors (MAOIs), tricyclic antidepressants, and selective serotonin reuptake inhibitors (SSRIs). Antipsychotic drugs are used to control delusions, hallucinations, and bizarre behavior and include the typical neuroleptics, atypical neuroleptics, and partial dopamine agonists. Antimanic drugs are used to treat bipolar disorder and include lithium and certain anticonvulsant drugs. Antianxiety drugs are used to treat anxiety disorders and include the benzodiazepines and certain antidepressant drugs. Electroconvulsive therapy (ECT) is used to treat severe depression, bipolar disorder, and schizophrenia and involves the use of muscle relaxant, a short-term anesthetic, and relatively mild muscular contractions. The types of psychosurgery are prefrontal lobotomy and cingulotomy. Psychologically based therapies are the kind of therapy or treatment in which a trained professional—a therapist—uses psychological techniques to help someone overcome psychological difficulties and disorders, resolve problems in living, or bring about personal growth. According to the psychotherapeutic treatment, they are divided into four major categories: psychodynamic (or psychoanalytic), humanistic, behavioral, and cognitive. The first two types are insight therapies in which the main goal is helping people to gain insight into their behavior, thoughts, and feelings. The last two are action therapies in which the main goal is to change disordered or inappropriate behavior directly. These approaches are based on the models of personality and psychological disorders developed by European or American psychologists in different countries, in different decades of the 20th century.
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Psychologically based therapies are the kind of therapy or treatment in which a trained professional—a therapist—uses psychological techniques to help someone overcome psychological difficulties and disorders, resolve problems in living, or bring about personal growth.
Psychodynamic therapy is based on the premise, first suggested by Sigmund Freud (1856–1939) in his psychoanalytic approach to personality, that the primary sources of abnormal behavior are unresolved past conflicts and the possibility that unacceptable unconscious impulses will enter a person’s consciousness. To guard against this anxiety-provoking possibility, individuals employ defense mechanisms, psychological strategies to protect themselves from those unconscious impulses. Classic Freudian psychodynamic therapy, called psychoanalysis, tends to be a lengthy and expensive affair. Patients typically meet with the therapist an hour a day, four to six days a week, for several years. When using the method of free associations, psycho-
analysts tell the patients to say aloud whatever comes to mind, regardless of its apparent irrelevance or senselessness, and the analyst attempts to recognize and label the connections between what a patient says and the patient’s unconscious. Therapists also use dream interpretation, examining dreams to find clues to unconscious conflicts and problems. Because of the close, almost intimate interaction between patient and psychoanalyst, the relationship between the two often becomes emotionally charged. Patients may eventually think of the analyst as a symbol of a significant other in their past. This phenomenon is known as transference. Although modern psychodynamic therapists have modified Freud’s techniques so that it takes less time
1448 Psychotherapy and is much more direct, they use interpretation of dreams, free association, positive and negative transference, and resistance to help patients reveal their unconscious concerns. Psychodynamic therapists face the challenge of finding a way to assist patients’ attempts to explore and understand the unconscious. The technique basically consists of guiding patients to consider and discuss their past experiences, in explicit detail, from the time of their first memories. This process assumes that patients will eventually stumble upon long-hidden crises, traumas, and conflicts that are producing anxiety in their adult lives. They will then be able to “work through”—understand and rectify—those difficulties. Humanistic therapies focus on the conscious mind and subjective experience to help clients gain insights. They emphasize the subjective interpretation of experience and the human capacity for self-determination. They seek to reduce blocks to growth that can create a poor self-concept. Humanistic therapists believe that clients who are more accepting will be better able to solve their own problems. The two most common therapy styles based on humanistic theory are Carl Rogers’s person-centered therapy and Fritz Perls’s gestalt therapy. The main elements of person-centered therapy are reflection of the client’s statements by the therapist; unconditioned positive regard given to the client by the therapist; the empathy of the therapist for the client; the authenticity of the therapists to the client’s perception. Person-centered therapy is very nondirective, allowing the client to talk through problems and concerns while the therapist provides a supportive background. Gestalt therapy is directive. It helps clients become aware of their feelings and to take responsibility for their choices in life. Gestalt therapies try to help clients deal with things in their past that they have denied. Gestalt therapists use clients’ body language and other nonverbal cues to understand what clients are really saying. In general, humanistic therapies work best with intelligent, highly verbal persons. Behavior therapies are based on the principle of classical conditioning, operant conditioning, and modeling. Unlike the psychodynamic and humanistic therapies, behavior therapies are action based rather than insight based. Their aim is to change the behavior through the use of the same kinds of learning tech-
niques that people use to learn any new responses. The abnormal and undesirable behavior is not seen as a symptom of anything else but is rather the problem itself. Learning created the problem, and new learning can correct it. Behavior therapies are action therapies that do not look at thought processes, but instead, focus on changing the abnormal or disordered behavior itself through classical or operant conditioning. Classical conditioning techniques for changing behavior include systematic desensitization, aversion therapy, and flooding. Therapies based on operant conditioning include modeling, reinforcement and the use of token economies, and extinction. Behavioral therapies can be effective in treating specific problems, such as bed-wetting, drug addictions, and phobias, and can help improve some of the more troubling behavioral symptoms associated with more severe disorders. Cognitive therapies are action therapies that work at changing a person’s illogical and distorted thinking. Rather than focusing on the behavior itself, the cognitive therapist focuses on the distorted thinking and unrealistic beliefs that lead to maladaptive behavior, especially those distortions relating to depression. The goal is to help clients test, in a more objective, scientific way, the truth of their beliefs and assumptions. Beck’s theory on and approach to treatment of depression is an example of cognitive therapy. Rational emotive behavioral therapy (REBT) and eye-movement desensitizing and reprocessing (EMDR) are examples of eclectic therapy. REBT is a directive therapy in which the therapist challenges clients’ irrational beliefs, often arguing with clients and even assigning them homework. Although REBT has seemed successful in treating depression, stress disorders, and anxiety, it has been criticized for focusing on the symptoms and not on the causes of disordered behavior. EMDR involves moving the eyes back and forth rapidly while concentrating on disturbing thoughts. The disturbing thoughts are supposed to be controlled or eliminated by this process. Although studies seem to show that it is effective in treating stress and anxiety disorders, other research has found that it is not always effective and criticized the way in which the recovery is measured in the supportive studies. More controlled studies are needed. The main goals of eclectic cognitive behavioral therapy is to relieve the symptoms and solve the problems,
Public Health
to develop strategies for solving future problems, and to help change irrational, distorted thinking. Therapeutic alliance (the relationship between therapist and client that develops as a warm, caring, accepting relationship characterized by empathy, mutual respect, and understanding) is considered to be the main characteristic of effective therapy. Evidence suggests that particular therapies are effective in alleviating certain problem behaviors. An alternative to individual therapy is group therapy. Group therapy can be a primary form of treatment or an adjunct to individual sessions; its different forms depend on the individuals who compose the groups, the problems or disorders they are confronting, the role the group leader takes, and the therapeutic goals that have been established. In group therapy, clients discuss problems in groups that may include individuals with similar problems. A variation of group therapy is self-help or support groups. Group therapy can be accomplished using many styles of psychotherapy and may involve treating people who are all part of the same family, as in family counseling. Group therapy has the advantage of low cost, exposure to other people with similar problems, social interaction with others, and social and emotional support from people with similar disorders or problems. Group therapy is most useful to persons who cannot afford individual therapy and who may obtain a greater deal of social and emotional support from other members. In computer age, we can also use cybertherapy, which refers to psychotherapy that is offered in the internet or at Web sites. People who practice it are called cybertherapists. They may or may not be trained in psychotherapy. Cybertherapy offers advantages of anonymity and therapy for people who cannot otherwise get to a therapist. SEE ALSO: Depression; Mental Health; Psychiatrist; Psy-
chiatry; Psychologist; Psychology.
Bibliography. A. T. Beck, Cognitive Theory and the
Emotional Disorders (Penguin Books, 1979); A. Ellis, The Practice of Rational Emotive Behavior Therapy (Springer, 1997); H. J. Eysenck, “The Effects of Psychotherapy: An Evaluation,” Journal of Consulting Psychology (v.16, 1957); A. Freud, The Ego and the Mechanisms of Defense (Indiana University Press, 1946); S. Freud, “The Ego and the Id,” S.E. (v.7, 1923); S. Freud, “Freud’s Psychoanalytic Pro-
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cedure,” S.E. (v.7, 1904); S. Freud, The Interpretation of Dreams, A. A. Brill, trans. (Macmillan, 1913); S. Freud, “The Psychopathology of Everyday Life,” S.E. (v.6, 1901); F. Perls, Gestalt Therapy (Julian Press, 1951); C. Rogers, On Becoming a Person: A Therapist’s View of Psychology (Houghton/Mifflin, 1961); B. F. Skinner, About Behaviorism (Knopf, 1974). Samvel Jeshmaridian, Ph.D. American Psychological Association
Public Health The participants at the 1978 Primary Health Care conference at Alma Ata effectively redefined health as “a state of complete physical, mental and social wellbeing, not merely the absence of disease or infirmity.” The Ottawa Charter on Health Promotion expanded this definition by stating that the prerequisites for good health are peace, shelter, education, food, income, a stable ecosystem, sustainable resources, social justice, and equity. Further, the preamble to the Constitution of the World Health Organization (WHO) casts health as “one of the fundamental rights of every human being.” Public health is the science of protecting and improving the broadly defined health of communities through education, promotion of healthy and productive lifestyles, and fulfillment of society’s interest in assuring conditions in which people can be healthy. It is for this reason that former U.S. surgeon general C. Everett Koop stated that “healthcare matters to all of us some of the time, [but] public health matters to all of us all the time.” Often defined in contrast to clinical medicine, public health focuses on the well-being of populations while clinical medicine focuses on individuals; public health focuses on proactively preventing problems while clinical medicine focuses on individual cures. Public health encompasses both micro- and macrolevel determinants of disease and wellness. Public health seeks out and examines factors that lead to illness, to care seeking and to postclinical outcomes. The populations of interest to public health can be as small as a household or local neighborhood or as big a country or region. Populations of interest may
1450 Public Health be defined by stage in the life course, environmental context, ethnicity, socioeconomic position, or by risk factors for disease. Public health professionals try to prevent problems from happening or reoccurring through implementing educational programs, developing policies, administering services, and conducting research. Public health considers many layers of influence: individual/population health, pathophysiologic pathways, genetic/constitutional factors, individual risk, social relationships, living conditions, neighborhoods and communities, institutions, and social and economic policies. Some people refer to public health as having an “upstream” focus, as detailed in the McKinlay model. This model suggests that a downstream focus is on the individual’s lifestyle or behavior. The midstream focus is on community and institutions within communities. Clinical practice is more akin to a downstream focus, while public health looks farther and farther upstream for root causes. Public health is inherently a multidisciplinary study. Schools of public health encompass a wide array of fields, including biostatistics, environmental health, toxicology, epidemiology, genetics, infectious diseases, chronic diseases, health policy development and analysis, health services management, health education, health behavior, health communications, immunology, nutrition, global health, and human development. The broad goals and tasks of public health necessitate this wide span of curriculum. The main goals of public health are assessment and monitoring of the health of communities and populations at risk to identify health problems and priorities; formulation of public policies, in collaboration with community and government leaders, designed to solve identified health problems and priorities; assurance that all populations can access appropriate and costeffective care, including health promotion and disease prevention services; and evaluation of the effectiveness of that care. Ten major tasks have been deemed necessary to reach these goals: • Monitoring health status to identify health problems • Diagnosing and investigating community health problems and hazards • Informing, educating, empowering, and mobilizing people around health issues
• Developing policies and plans that support individual and community health efforts • Enforcing laws and regulations that protect health and ensure safety • Linking people to needed health services and assuring its provision everywhere • Assuring a competent health workforce • Evaluating the effectiveness, accessibility, and quality of health services • Research for new insights and innovative solutions to health problems History Early movements in public health centered on sanitation and hygiene, arguably since the growth of ancient cities and certainly since the Industrial Revolution. Although the etiologic understandings were often wrong, 19th-century doctors correctly recognized that hygiene plays a critical role in the maintenance of good health. In the 19th century, doctors widely believed that disease spread through miasmas, or noxious gases, thought to arise from sites of organic decay. Proponents of the miasma theory stressed cleansing and scouring as methods of prevention. Although Anton von Leeuwenhoek had viewed microorganisms in the 17th century, germ theory did not gain credibility until the 1835 work of Agostino Bassi and did not gain dominance until the work of Louis Pasteur in the 1860s. During this period of changing views of health at home, European and American countries also became interested in tropical medicine, an outgrowth of projects of colonialism. Colonial powers wanted to protect their military personnel, administrators, merchants, and settlers who met with new disease as they settled new regions of the globe. Later, this concern expanded to keeping local populations, and especially the work force, healthy. Western medical practitioners largely guided the implementation of medical systems and helped influence how diseases were studied and controlled. Schools of hygiene and tropical medicine began cropping up at the end of the 19th century; the names of many schools of public health still bear witness to the legacy of colonial health. Although public health aims to “do good,” its colonial history and other incidents have denigrated its reputation in the minds of some people and populations. The Tuskegee syphilis trials provide a salient
example. Launched in 1932 by the U.S. Public Health Service, the study was to be a natural experiment in the progression of syphilis. Four hundred black, syphilitic men from Macon Country, Georgia, joined the study under the premise that they were being treated for their condition when, in fact, they remained actively untreated for 40 years. This time span included the advent of penicillin, which could treat syphilis. President Bill Clinton formally apologized in 1996. Public Health Delivery Most countries have a Ministry of Health or its equivalent. Basic services, such as childhood immunizations or free health clinics, may be free to the entire population. Governments often run or oversee public facilities, such as clinics and hospitals, and in countries with nonsocialized healthcare, the private sector may be very involved in providing services and products to patients. There are many funding mechanisms for health, but it is not uncommon to have an insurance or risk-pooling system, given the nature of unexpected health-related catastrophic events. Key Figures in Public Health In the 1790s, Edward Jenner developed the technique and practice for smallpox vaccinations. Prior to this time, people relied on variolation, intentional infection with smallpox, to develop immunity. Although Benjamin Jesty had successfully induced immunity in his family during a 1774 epidemic, Jenner’s work was likely independent and was pivotal in the widespread understanding of the procedure. Jenner observed that milkmaids did not generally get smallpox and theorized that the pus in the blisters that milkmaids received from cowpox protected the milkmaids. Vaccinations developed from cowpox were much less dangerous than direct variolation with smallpox. British physician John Snow is one of the fathers of public health and epidemiology. He first publicized his water-based germ theory of cholera in 1849 and investigated the 1854 London cholera epidemic. By drawing a spot map of infected households and interviewing residents about their water procurement patterns, he identified the cause of the outbreak as water pumps supplied by certain companies, specifically the public water pump on Broad Street (now Broadwick). As both a physician and a politician, Rudolf Ludwig Karl Virchow worked to improve the healthcare
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conditions for citizens of Berlin. Virchow is credited with founding “social medicine,” focusing on the fact that disease is never purely biological but also socially derived. Hungarian physician Ignaz Philipp Semmelweis posited, in 1847, that washing hands and medical instruments could reduce puerperal fever incidents in obstetrical clinics. He noticed that doctor wards had higher mortality rates than midwife wards and concluded that doctors carried infecting particles from autopsies to their maternal patients. However, the medical community derided Semmelweis’s proposal; he only earned widespread acceptance as a pioneer of antiseptic policy and prevention years after his death. Carrying over from Louis Pasteur, Edward Jenner and an interest in tropical medicine, public health institutions have sought to eradicate infectious disease from the globe. The first focus was on smallpox, which the WHO declared eradicated in 1980. In 1955, Thomas Francis Jr, lead investigator on the human trials of J. E. Salk’s polio vaccine, announced that the vaccine as “safe, effective, and potent.” In 1963, an oral vaccine became available thanks to the work of A. B. Sabin. The 1988 World Health Assembly attendees voted to launch a global goal to eradicate polio. At the end of 2003, indigenous polio had been eliminated from all but six countries of the world. The public health literature frequently cites two theories about mortality patterning. In the 1970s, Thomas McKeown proposed that the declines in mortality in Europe beginning in the 18th century resulted more from changing nutritional standards than from medical or public health interventions. Although debate continues about his methods and findings, McKeown highlighted that many of our current medical problems will not be solved through clinical intervention alone. Second, in 1971, A. R. Omran coined the term epidemiologic transition to explain the shift in the main drivers of mortality and disease patterns from pandemics of infection to degenerative, “man-made” chronic diseases. Health education has become an important component of public health. Early proponents of public health education and studying behavior to inform public health include Mayhew Derryberry and Dorothy Bird Nyswander. Derryberry was the first chief of the U.S. Division of Health Education in the Public Health Service, where he assembled a team of behavioral
1452 Public Health scientists to study the nexus of behavior, social factors, and catalyzed the nation’s earliest efforts in heath promotion and disease prevention. Nyswander also promoted health education and applied behavioral sciences in public health. She urged public health workers and researchers to “go where the people are.” Paulo Freire’s work emphasized the empowering effects of education. In 1969, Friere wrote his most famous book, Pedagogy of the Oppressed. His work helped spur the model of community-based participatory research and participatory action research in public health. Several authors and journalists have contributed to the field of public health. A pioneer in this field, Rachel Carson penned Silent Spring, an exposition on the dangers of dichlor-diphenyl-trichlor (DDT) to the environment. Citing Silent Spring as her inspiration, science journalist and writer Laurie Garrett authored The Coming Plague, which discussed the vulnerability of the world to disease due to the lack of attention and funding given to health. She won the Pulitzer Prize for Explanatory Journalism in 1996. Paul Ehrlich, author of The Population Bomb spurred much debate over resources and demographic change in the 1970s. The WHO is the branch of the United Nations charged with deciding international health policy based on the principal that all people are entitled to the highest possible attainment of health status. Former Director-General Gro Harlem-Brundtland established the Brundtland Commission, which made recommendations regarding environmental sustainability, and the Commission on Macroeconomics and Health, which linked a country’s ability for economic growth to its health status. Recent Director-General Lee Jong-Wook focused on action, as exemplified in his ambitious plans to treat global HIV/AIDS by delivering antiretroviral therapy to 3 million more people by 2005 through the 3 x 5 Initiative. Paul Farmer and Jim Kim cofounded the nonprofit organization Partners in Health and have authored many books on health and social justice. They advocate for the highest level of medical and technological intervention for every person, including a “preferential option for the poor.” Farmer and Kim champion health and healthy social conditions free of “structural violence” as a human right. In 2003, New York City mayor Michael Bloomberg extended the city’s smoking ban to all commercial es-
tablishments. Bloomberg’s smoking ban is considered trend setting. The Johns Hopkins School of Public Health became the Bloomberg School in 2001. Recently, new waves of funding from large foundations have supported global health research program implementation. The Bill and Melinda Gates Foundation awards many grants, including ones for neglected tropical diseases and for innovative, successful civil society organizations. Their work and partnership with U2 bandmember Bono earned the trio the title of Time’s People of the Year in 2005. The Buffet Foundation supports family planning initiatives as well as giving through the Gates Foundation. Former U.S. president Jimmy Carter’s Carter Center focuses on eliminating less-common diseases, such as river blindness (onchocerciasis) and advocates for health and humanitarian rights. Former U.S. president Bill Clinton’s Clinton Global Initiative has successfully negotiated lowered prices on antiretroviral drugs for HIV for governments of countries with low income. Philanthropist George Soros has supported many smaller global initiatives such as Partners in Health and the Earth Institute. His Open Society Institute works to allow more civil society input into the administration of global health. Measuring Public Health Measuring overall health status of a population is an almost impossible task. Certain indicators have become standard for evaluating health systems and overall health. Commonly used measures are life expectancy at birth and infant mortality rates. In 1996, Murray and Lopez at WHO created a measurement called disability-adjusted life-years (DALYs) to change life expectancy when a large part of the population is living with serious morbidities. Quality-adjusted lifeyears (QUALYs) is another way to measure years lived in less-than-full health. Countries are often ranked by their economic growth, either the Gross National or Gross Domestics Products (GNP/GDP) and these are sometimes good measures of overall wealth and health in a country. Yet, some countries, such as Cuba, have low GDP but high health indicators, due to socialized healthcare, while a country such as Qatar has a high GDP but lower health indicators. However, other measures look at health more directly, such as mortality rates, life expectancies, and disease prevalence. The Human
Public Health
Development Index (HDI) combines national wealth, life expectancy, and average literacy rates to form a ranking used by the United Nations. In 2000, the WHO published a controversial report on the ranking of health systems worldwide. Public Health Achievements/Movements Over the years, there have been many efforts at galvanizing for universal improvement of health and healthcare. Health for All by 2000 was a strategy developed at the aforementioned 1978 Primary Health Care conference in Alma Ata, considered a defining moment in making primary healthcare an international priority. This strategy is a precedent for many current initiatives. The Alma Ata declaration clearly stated that every person has entitlement to primary healthcare and that its provision to everyone should be a national and international priority. Many countries have similar analogs, such as the United States’ Healthy People 2010, which aims to improve all health by the year 2010. Many United Nations initiatives are disease specific, such as the 3 x 5 program to treat people infected with HIV/AIDS. The Roll Back Malaria (RBM) program was started to reduce incidence of malarial disease through insecticide-treated bed nets and artemesinin combination therapy. Directly Observed Therapy Short-Course (DOTS) is a strategy used for treatment of tuberculosis, a very contagious airborne disease. The DOTS method involves patients taking medications under watch of a clinician to ensure compliance with the drug regimen. In 2000, the United Nations set forth a set of quantifiable, timebound goals to reduce poverty and ill-health around the world by 2015. The goals are as follows: • Eradicate extreme poverty and hunger • Achieve universal primary education • Promote gender equality and empower women • Reduce child mortality • Improve maternal health • Combat HIV/AIDS and other diseases • Ensure environmental sustainability • Develop a global partnership for development The Millennium Development Goals (MDGs) call for increased donor funding to developing countries and strengthened national health systems around the world. Although the MDGs have been criticized for excluding explicit goals on sexual health, human
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rights, and intracountry equity, they have gained the attention of the public and have shaped many current health and development programs. The Centers for Disease Control and Prevention (CDC) has identified 10 major achievements in public health. Vaccination programs have helped control diseases such as smallpox and polio. Motor vehicle safety has improved engineering of vehicles, roads, and safety gear as well as improved driving habits. Workplaces have become safer by reducing disease and injury from manufacturing and construction. Some infectious diseases, such as typhoid and cholera, have been controlled through cleaner water and better sanitation, as well as antimicrobial therapy. Behavior change, earlier detection, and better treatment have all led to decline in coronary heart diseases and strokes. Food choices have become healthier and safer and many foods have been fortified with vitamins and micronutrients. Improvements in hygiene and nutrition, and access to healthcare, antibiotics, and technological innovations have improved maternal and neonatal health and survival. Family planning programs have provided benefits to family size and birth spacing, and the availability of contraceptive devices have reduced infection by sexually transmitted diseases. Fluoridated drinking water has greatly improved dental health and oral hygiene. The recognition of tobacco as a health hazard has influenced the decrease in cigarette smoking and the number of smoking-related deaths. See Also: AIDS; Disease Prevention; Malaria; Nutrition;
Tuberculosis.
Bibliography. Warwick Anderson, “Immunities of Em-
pire: Race, Disease, and the New Tropical Medicine, 19001920,” Bulletin of the History of Medicine (v.70/1, 1996); Alison Bashford, Imperial Hygiene: A Critical History of Colonialism, Nationalism and Public Health (Macmillan, 2004); Centers for Disease Control and Prevention, “150th Anniversary of John Snow and the Pump Handle,” MMWR, Morbidity and Mortality Weekly Report (v.53/34, 2004); Centers for Disease Control and Prevention, “Ten Great Public Health Achievements—United States, 19001999,” MMWR, Morbidity and Mortality Weekly Report (v.48/12, 1999); G. Condran, “Commentary: History in the Search of Policy,” International Journal of Epidemiology
1454 Pulmonary Embolism (v.34, 2005); Deirdre Cunningham, “Tackling Global Inequalities—Lessons From History,” Journal of Public Health (v.26/4, 2004); Elizabeth T. Hurren, “Poor Law versus Public Health: Diphtheria, Sanitary Reform, and the ‘Crusade’ against Outdoor Relief, 1870-1900,” Social History of Medicine (v.18/3, 2005); Institute of Medicine, The Future of the Public’s Health in the 21st Century (National Academy Press, 2003); G. Kaplan, “What’s Wrong with Social Epidemiology, and How Can We Make It Better?” Epidemiologic Reviews (v.26, 2004); C.E. Koop, Koop: The Memoirs of America’s Family Doctor (Random House, 1991); Paul Lombardo, et al., “Eugenics, Medical Education, and the Public Health Service: Another Perspective on the Tuskegee Syphilis Experiment,” Bulletin of the History of Medicine (v.80/2, 2006); J. B. McKinlay, “The New Public Health Approach to Improving Physical Activity and Autonomy in Older Populations,” Preparation for Aging (Plenum Press, 1995); T. McKeown, The Modern Rise of Population (Academic Press, 1976); G. Rosen, History of Public Health, 1st ed. (The Johns Hopkins University Press, 1993); B. J. Turnock, Public Health: What it is and How it Works, 3rd ed. (Jones and Bartlett Publishers, 2004); M. Wirth, et al., “Setting the Stage for Equity-Sensitive Monitoring of the Maternal and Child Health MDGs.” Bulletin of the World Health Organization (cited July 2006). Emma Sacks Columbia University
Pulmonary Embolism Pulmonary embolism (PE) is a common and potentially life-threatening disease that affects 0.5 to 1 per 1,000 people yearly. PE usually results from a blood clot that originates in the deep veins of the legs or pelvis and travels to the pulmonary vessels, where it becomes lodged and prevents proper blood flow to the lung tissue. This serious disease is among the more difficult to detect because of its vague and nonspecific symptoms. Individuals with PE most commonly present with difficulty breathing (dyspnea) and/or chest pain, symptoms that can be caused by many different medical problems. Risk factor assessment may help physicians determine the likelihood of PE, but even patients without identifiable risk factors have been found
with pulmonary emboli. Fortunately, anticoagulation treatment is highly effective at preventing death and disease recurrence when PE is detected early. Pulmonary emboli result from venous thrombi (blood clots) that travel through the blood stream as emboli and lodge in the pulmonary vessels of the lungs. Thrombi that cause PE usually form in the deep veins of the legs or pelvis, and approximately half of people with documented deep vein thrombosis (DVT) are found to have a PE. Very large emboli may lodge at the bifurcation of the pulmonary arteries, forming what is known as a saddle embolus and leading to rapid circulatory failure or sudden death. Most emboli, however, lodge in smaller vessels and may lead to acute changes in respiratory and cardiovascular function. Obstruction of the pulmonary arteries compromises respiratory function by elevating vascular resistance in the lungs and impairing gas exchange. Cardiac ischemia reduces right ventricular function which can then lead to decreased cardiac output. Although DVT and, subsequently, PE can occur in anyone, there are factors that increase the likelihood of an event. Those that are most strongly associated with PE include major surgery, trauma, advanced age, history of prior PE or DVT, immobility, smoking, obesity, medical illness, cancer, and pregnancy. PE is among the most difficult medical conditions to accurately diagnose because its symptoms are often vague and nonspecific. Sudden dyspnea at rest is the most frequent symptom, along with tachypnea (rapid breathing). Other symptoms include increased heart rate, sharp chest pain, lowgrade fever, acute onset of cough, unexplained loss of consciousness, and hemoptysis (coughing up blood). Physicians must, therefore, have a high index of suspicion in patients that present with any of these vague symptoms. A number of studies are available to aide in the diagnosis of a PE. In individuals who have a low probability of PE based on their risk factors, measurement of the plasma D-dimer concentration can be performed through a simple blood test. If the concentration is normal in these low-risk individuals, PE may be ruled out. If the concentration is elevated, or if the individual has risk factors that make having a PE more likely, further testing must be performed. Although chest X-rays and electro-
Pulmonary Fibrosis
cardiograms are frequently taken, these tests rarely provide evidence to support the diagnosis of PE. Instead, they are helpful in identifying and ruling out other causes of chest pain. The so-called gold standard test for detection of PE is contrast pulmonary angiography, a procedure in which a catheter is inserted into a central vein and passed through the heart to inject dye into the pulmonary arteries. The test is highly sensitive, but it is also expensive and carries significant risks. Because of these limitations, pulmonary angiography is not typically a first-line diagnostic tool. Ventilation-perfusion (V/Q) lung scanning using nuclear isotopes is less invasive and expensive than pulmonary angiography. V/Q scans detect areas of the lungs that are ventilated but not receiving blood and can be read as normal, low probability, indeterminate, and high probability. For low probability and indeterminate scans, the patient must undergo pulmonary angiography or high-resolution computed tomographic angiography (CTA) for a more definitive answer. CTA is also highly accurate, but patients receive significant doses of radiation during the scan. Treatment for PE is immediate anticoagulation with subcutaneous low molecular weight heparins or intravenous unfractionated heparin. For individuals with signs of a serious PE, such as those with hypotension or cyanosis, thrombolytic therapy is often used. However, there are serious risks associated with the use of thrombolytics, including the risks of bleeding and intracranial hemorrhage. Before leaving the hospital patients are then transitioned to warfarin, an oral blood thinner. It is suggested that patients with identifiable risk factors be anticoagulated for a minimum of three months, and that those without know risk factors be on anticoagulants for at least six months. SEE ALSO: Angina; Fainting; Fever; Pulmonology. Bibliography. David Garcia, Walter Ageno, and Ed-
ward Libby, “Update on the Diagnosis and Management of Pulmonary Embolism,” British Journal of Haematology (v.131/3, 2005); J. Willis Hurst and Douglas C. Morris, Chest Pain (Futura, 2001). Celina Martinez, M.D. Johns Hopkins University
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Pulmonary Fibrosis Also known as interstitial lung disease, pulmonary fibrosis is a devastating condition resulting in the permanent loss of lung tissue’s ability to exchange and transport vital gases. The condition predominantly affects males, individuals over 50, and does not demonstrate any geographical or ethnic preference. Although the exact etiology is elusive in many cases, reported causes of the disease include environmental exposure to metal dusts, connective tissue diseases, drugs, radiation, viral infection, acid reflux disease, and genetic predisposition. Pathophysiology Despite the etiology or variance in the course of disease among patients, the process leading to lung fibrosis remains constant. Mechanical, chemical, or physical injury to lung tissue all have potential to initiate an inflammatory process that inflicts damage to virtually all components of lungs including the airways, air sacs, and vasculature. Inflammation may either progress and become chronic leading to permanent scarring (i.e., pulmonary fibrosis) or resolve, resulting in healing. In cases of the former, subsequent fibrosis results in permanent loss of normal lung function and manifests through severe respiratory symptoms. Such symptoms are a result of physiologic consequences attributed to the lungs inability to carry sufficient amounts of oxygen and deterred ability to exchange vital gasses. However, the severity of the disease is dependent on the extent of inflammatory damage. Clinical Manifestations The condition is demanding of a thorough history inclusive of environmental factors, hobbies, drug use, and autoimmune conditions. Symptoms of exertional dyspnea (shortness of breath), chest pain, cough, fatigue, fever, and diminished exercise tolerance are most common. Physical examination may be unremarkable with the exception of auscultated inspiratory crackles. However, in advanced conditions, symptoms of heart failure accompanied with lower extremity swelling are often noted. Diagnostic tests include blood tests, pulmonary function tests, imaging studies, and if necessary, a lung biopsy. Although laboratory studies seldom provide
1456 Pulmonology diagnostic aid leading to a diagnosis, they often help to exclude secondary causes of fibrosis. Inflammatory markers such as elevated erythrocyte sedimentation rate (ESR) and immune complexes are commonly documented findings among disease carriers. Other autoimmune markers such as rheumatoid factor (RF) and antinuclear antibodies (ANA) are often unusually positive in patients even in the absence of an organic autoimmune condition. Pulmonary function studies are most distinguishing indicating an abnormal restrictive pattern and arterial blood gas studies often disclose hypoxia (decreased blood oxygen level). Diagnostically, chest X-ray (CXR) and high-resolution computerized axial tomography (HRCT) scan frequently demonstrate a trademark “honeycombing” lesion specific to fibrosis. However, HRCT is the preferred imaging study as CXR has been reported to exhibit normal results in as many as 10 percent of patients. In the event that imaging studies show no changes, a video-assisted thoracoscopic (VAST) lung biopsy is indicated to make the diagnosis for pulmonary fibrosis. During this procedure, a sample of the cellular tissue is extracted and analyzed by a pathologist to make the diagnosis. However, a lung biopsy is not routinely necessary when imaging studies are strongly remarkable for the aforementioned fibrotic changes. Treatment and Prognosis As yet, no cure for pulmonary fibrosis exists. However, current treatment guidelines are designed to deter the progression of disease and reduce symptoms. Unfortunately, prognosis is typically poor among the majority of patients. Patients with better prognosis include disease carriers of younger age, female gender, milder respiratory symptoms, and good response to treatment. Treatment approaches entail the administration of corticosteroid therapy to reduce the production of inflammatory mediators and immunosuppressive medications such as cyclophosphomide or azathioprine to prevent disease succession. Severe cases require the prescription of oxygen therapy in addition to use of corticosteroids. Lung transplantation may be considered for patients with a deteriorating condition exhibited by severe functional impairment, oxygen dependency, and other respiratory related comorbidities.
Prevention of disease exacerbation entails the maintenance of a healthy lifestyle inclusive of smoking cessation, adequate rest, and respiratory physical therapy. SEE ALSO: Autoimmune Diseases; Chemotherapy; Laboratory Tests; Respiratory Diseases; Sarcoidosis. Bibliography. M. A. Hospenthal, “Diagnosis and Man-
agement of Idiopathic Pulmonary Fibrosis: Implications for Respiratory Care,” Respiratory Care (v.51/4, 2006); M. P. Keane, R. M. Strieter, and J. A. Belperio, ; K. Kuwano, N. Hagimoto, and N. Hara, “Molecular Mechanisms of Pulmonary Fibrosis and Current Treatment,” Current Molecular Medicine (v.1/5, 2001); The Merck Manual, “Idiopathic Pulmonary Diseases,” www.merck.com/mrkshared/mmanual/section6/chapter78/78b.jsp (cited June 2007). Utkarsh Acharya Ohio University College of Medicine
Pulmonology Pulmonology refers to the study of diseases of the lung and chest. Specialists in pulmonology hold advanced expertise and skills in the diagnosis and management of chest/lung diseases and are variably referred to by such terms as pulmonologist, chest physician, or respirologist. Pulmonologists hold one of the following requisite medical degrees: M.D. (medical doctor), D.O. (doctor of osteopathic medicine), or M.B.B.S. (bachelor of medicine and surgery). The M.D. and D.O. degrees are offered in the United States to physicians following successful completion of (typically) four years of medical school. The M.B.B.S. degree is obtained outside of the United States from medical schools on the continents of Europe, Asia, and Australia. Following receipt of one of the above medical degrees, a pulmonologist will complete residency training in the specialty of internal medicine (knowledge and management of diseases of the heart, lungs, liver, kidneys, brain and nervous system, pancreas, thyroid, cancer, and diseases of the aged) which traditionally involves three years of training following receipt of the medical degree); in addition, a pulmonologist will have completed a fellowship in pulmonary diseases (two to three years
of specialized training following completion of the internal medicine residency). Board certification for both internal medicine and pulmonary diseases is obtained from one of several specialty boards, including the American Board of Internal Medicine (ABIM) and/or the American Osteopathic Board of Internal Medicine (AOBIM) for physicians training in the United States, or another country-specific certifying agency. Many pulmonologists have also completed specialized training and board certification in critical care medicine (care of intensive care unit patients). Scope of Practice While those who practice pulmonology may serve as specialty consultants for physicians in primary care, many pulmonologists also practice primary care medicine. The expertise of pulmonologists includes the disciplines of internal medicine with additional specialized expertise in the diagnosis and management of lung diseases. Lung diseases diagnosed and treated by pulmonologists include but are not limited to asthma, chronic cough, coughing up blood, tobacco addiction, chronic obstructive pulmonary disease (COPD, a term which includes emphysema and chronic bronchitis), bronchitis, pneumonia, sleep apnea, cystic fibrosis, lung cancer, chest infections (tuberculosis; fungal diseases including histoplasmosis; coccidiodomycosis, also known as valley fever; blastomycosis); pulmonary embolism (blood clots in the lung); pulmonary fibrosis; occupational lung diseases (including asbestosis; silicosis, also known as sand-blasters disease); lung trauma; and sarcoidosis. Procedures for which pulmonologists receive specialized training and hold specialty expertise include performance of and interpretation of the following: • Lung function studies (used to diagnose and follow response to therapy of asthma, COPD, occupational lung diseases, pulmonary fibrosis) • Interpretation of chest imaging studies including chest X-rays, computed tomography (CT) scans, angiograms, and so forth • Application of mechanical ventilation (artificial means of breathing for a patient who is unable to breath for him- or herself ) • Bronchoscopy—bronchoscopy is a procedure performed by a pulmonologist which may be
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done as an outpatient. The pulmonologist monitors the administration of intravenous sedation to the patient while ensuring the patient’s ability to breathe for him- or herself. Following topical sedation with lidocaine (similar to what a dentist uses), a flexible bronchoscope (a tube the approximate diameter of a pencil eraser with a light and camera on the tip) is then passed through the nose or mouth to the voice box, down between the vocal cords into the main breathing tube. Biopsies of irregular areas and washings of the breathing tubes are obtained with very rare complication. These biopsies (up to 2–3 mm in size) are sent to the laboratory • Biopsy of the pleura and lung—the pleura is the membrane that covers the lung and is frequently a site of infection or tumor invasion. Pleural biopsies are performed by anesthetizing the chest wall and passing a biopsy needle through the chest wall to the pleural surface. Similarly, lung biopsies are performed by passing a needle through the chest wall and pleura to the lung. CT scans are frequently used to guide the placement of the needle being used for lung biopsy • Placement of chest tubes (these are placed to treat lung collapse or to drain blood or fluid which has collected around the lung) • Tracheostomy (placement of a tube in the windpipe) • Placement of central venous catheters (these are large intravenous lines placed in the large, central veins, such as the subclavian, femoral, or internal jugular vein), particularly in intensive care unit patients, for the purpose of giving blood transfusions, intravenous fluids or medications, and nutritional support • Placement of arterial lines (these are central monitoring lines placed in the arteries to monitor blood pressure and oxygenation status of critically ill patients) • Placement of Swan-Ganz catheters (used to monitor heart function of critically ill patients) • Placement of pacemakers (for disorders of heart rhythm) Team-Based Medical Care Pulmonologists, by virtue of their training and expertise, are frequently tapped to serve as team leaders in
1458 Pulmonology respiratory care units and intensive care units, working closely with nurses, pharmacists, respiratory therapists, anesthesiologists, chest surgeons, and other consultants to deliver the highest-quality patient care possible.
Candidates for fellowship in the ACCP also include thoracic surgeons, cardiologists, and other physicians who hold specialty certification in diseases related to the chest.
Special Recognition of Expertise Added qualifications are held by some pulmonologists. Membership and particularly the award of a fellowship in chest medicine, offered by the American College of Chest Physicians (ACCP), connotes both board certification and recognition by peers of the pulmonologist as an expert in chest medicine. In addition, following the pulmonologist’s signature and medical degree, of the notation FCCP, denotes that the pulmonologist has been awarded fellowship status by the American College of Chest Physicians.
SEE ALSO: Asthma; Chronic Obstructive Pulmonary Disease
(COPD); Lung Transplantation; Sarcoidosis; Tuberculosis.
Bibliography. American College of Chest Physicians,
www.chestnet.org (cited July 2007); Lorri A. Zipperer, ed., The Health Care Almanac: A Resource Guide to the Medical Field (American Medical Association, 1995). Sandra K. Willsie, D.O. Kansas City University of Medicine and Biosciences
Q Qatar Located on the Persian Gulf, this Arab country was relatively poor until the discovery of oil. Most medical care used traditional herbal remedies or pastes, with a hospital opening at Doha, the country’s capital, in 1945, staffed by one doctor. Six years later, it had a British doctor and a small staff. The government opened the Rumailah Hospital, the first state hospital, in 1959. With added wealth, a 165-bed maternity hospital was opened in 1965. People with serious illnesses were sent overseas. During the 1970s, the provision of health care was dramatically improved with new oil wealth, with better medical care being at the forefront of the development of the country under Sheikh Khalifa, who acceded to the throne in 1972. The Rumailah Hospital, sometimes referred to as “Doha Hospital,” ceased to be a general hospital and is now a center for geriatric patients, psychiatric cases, and rehabilitative care. A Women’s Hospital was opened with 314 beds, and the Hamad General Hospital was opened in March 1982, with 1,100 beds. It has been equipped with facilities for emergency care, nuclear medicine, plastic surgery, cardiovascular treatment and tomography, as well as having departments concerned with dentistry, dermatology, and a small burns unit. There are also clinics
throughout the country which provide primary healthcare to many people. Many of the doctors working in Qatar were expatriates, includin Dr. Alwyn Gotting, who served in Qatar for 36 years and was appointed, in 1972, as the first Director of the Ministry of Public Health. He later become the medical attaché at the Qatar Embassy in London. His widow, Fay Gotting, wrote the authoritative history of medicine in Qatar. From the 1980’s more than 90 percent of births are attended by medical health professionals, and in 1993 there were 752 government physicians, with others working in private clinics in Doha. All hospital care in Qatar is free, even for visitors and tourists, and there are 126 doctors and 289 nurses per 100,000 people. SEE ALSO: Healthcare, Asia and Oceania; Herbal Medicine. BIBLIOGRAPHY. Fay Jacqueline Gotting, “History of Medi-
cine in Qatar,” PhD Thesis, University of Glasgow, 1995; Fay Jacqueline Gotting, Healing Hands of Qatar (Dar Al Sharq Press, 1996); Qatar into the Seventies (Qatar National Printing Press, 1970); Qatar Today (Ministry of Information, n.d.). Justin Corfield Geelong Grammar School, Australia
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R Rabies Rabies is an infectious viral disease that is generally known as hydrophobia (fear of water). In its early stages, the disease provokes irritability and rage in the affected creatures and this inspires them to bite other creatures, hence, passing the virus on through the animal’s saliva. The furious form of the disease is followed by a paralytic form characterized by inability to stand still, drooling, paralysis, and then death. The virus is transferred to the central nervous system where it becomes established after an incubation period of up to eight months. All mammals are susceptible to the virus, which is nearly always fatal among humans. The virus leads to flu-like symptoms which then develop into brain damage often accompanied by the symptoms that have brought about the description of hydrophobia, which include the apparent unwillingness to drink liquids caused by the inability to swallow. The only survivors from rabies suffer from often severe brain damage. Victims tend to become very distressed by the process of the disease. Only one person has ever been known to survive rabies without brain damage and it appears she was able to do so only because she entered an induced coma.
As a consequence of the lethality of the disease, severe steps are usually taken to eradicate the disease when outbreaks are reported. A successful vaccine was established by Louis Pasteur through his work on the central nervous system of dogs and it was successfully administered to a 9-year-old boy, Joseph Meister, in 1885. No serum exists presently, but the often lengthy incubation period offers some hope of respite; previously, the postexposure prophylaxis was administered through a painful series of intraabdominal injections with immunoglobulin. This process is assisted by the use of hygienic conditions and washing of bitten areas with soap and water, which can help in controlling the initial infection. Some research into the use of recombinant DNA technology has suggested that it will be possible to create a vaccine that will lead wild animals to become immune to the disease. Of course, there will still be a problem with locating the wild animals, especially in remote and difficult terrain, and causing them to take the medicine in whatever form it is constituted. Rabies is generally transmitted through the bites of domestic dogs or wild animals, which has led to extensive culling of animals in cases where the presence of rabies is suspected. In southern China, for example, an outbreak of rabies in 2006 led to the reported slaughter of some 50,000 dogs, many of which were
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1462 Radiation Exposure
Radiation Exposure Through many years of research and scientific studies, researchers have found that radiation is a carcinogen. The three most common forms of radiation that are seen in clinical settings include alpha radiation, beta radiation, and gamma radiation. Although some types of radiation such as X-ray are important in diagnosing possible cancer sites, too much of it can cause cancer. The primary damage caused by radiation is to the deoxyribonucleic acid (DNA)—the genetic materials of living cells. Thus, to lower the risk of radiation-induced cancer, people need to be more aware of the kinds of radiation that they can become exposed to. Rabies is generally transmitted through the bites of domestic dogs or wild animals, leading to extensive culling when rabies is suspected.
domestic pets. In most countries, China included, lack of sentimentality toward animals make the largescale culling an obvious precaution in times of need. In some Western countries, a more positive attitude toward animals both represents a potential threat among people unwilling to yield their animals to the authorities when necessary and also a powerful force in policy formation. In the United States, many domestic animals are required to be vaccinated against rabies and programs of vaccination are spreading around the world through the offices of such international organizations as the Food and Agricultural Organization of the United Nations. These programs have resulted in a decrease in the incidence of the disease and of infection of human beings. SEE ALSO: Paralysis; Viral Infections; Virology. BIBLIOGRAPHY. George M. Baer, The Natural History of
Rabies, 2nd ed. (CRC Press, 1991); Alan C. Jackson and William H. Wunner, eds., Rabies (Academic Press, 2002); Nicholas Zamiska, “Outbreak of Rabies Mars the Comeback of Canines in China; Killing of 50,000 Rural Dogs Angers Pet Lovers,” Wall Street Journal (August 8, 2006). John Walsh Shinawatra University
Incidents Showing the Link between Cancer and Radiation There have been many past incidents that indicate that radiation can cause cancer. Most of the data come from people who have inadvertently been exposed to various types of radiation in the past. As part of his discussion on radiation carcinogenesis, Steven B. Oppenheimer explained that the incidence of thyroid cancer is higher in people who have been treated with radioactive iodine. Radioactive iodine gathers in the thyroid once it is injected into the body. In another case, individuals who were once treated by x-ray irradiation of the head to get rid of scalp ringworms often developed head and neck cancers 10 to 20 years later. Also, people who have had jobs that exposed them to X-ray and radioactive chemicals (atomic bomb or the nuclear industry) often developed some kind of cancer in the future. Oppenheimer also mentioned that while anyone can get skin cancer, fair-skinned people and those who often work outdoor under the sun for long periods are most susceptible to getting skin cancer. Particulate Radiations and Electromagnetic Radiation Experimental studies in the Online Neurological Encyclopedia have found that both particulate radiations (neutrons, electrons, and alpha particles) and electromagnetic radiation (ultraviolet lights and X-rays) can cause cancer. Despite being a carcinogen, radiation is an important and necessary part of clinical diagnosing. Radiation has been commonly used as medication and
trace markers to allow physicians and clinical researchers to image the internal structures of the human body and detect possible cancerous sites. Higher doses of radiation are often necessary to kill cancerous cells. Three Kinds of Radiation: Alpha, Beta, and Gamma The U. S. Environmental Protection Agency (EPA) states that the three kinds of radiation that are used in the clinical setting include alpha, beta, and gamma radiation. Alpha radiation is the flow of alpha particles while the beta radiation is the flow of electrons. Gamma radiation is very high-energy ionizing radiation containing gamma photons. While gamma photons have no mass and no electrical charge, they are pure electromagnetic energy that has much more energy than the photons of the visible range of the electromagnetic spectrum. Because of their high energy, gamma photons can travel at the speed of light and pass through many different kinds of materials, including human tissue. Most also have enough energy to go through the body’s internal organs which can cause many health problems and diseases. According to Wolfram Research, alpha radiation is a type of radioactive decay consisting of alpha particles. These alpha particles are relatively large and, thus, do not move fast enough to penetrate through human tissue. Light shielding often blocks alpha radiation. According to the EPA, beta radiation is the flow of electrons. Because this type of radiation consists of electrons, beta particles have an electrical charge of minus 1. The speed of beta particles is not constant; the speed depends on how much energy they have. They can also travel over a wide range. When beta particles have high excess energy, they travel fast and can cause potential damages to the human body. Researchers have found that beta radiation can cause both acute and chronic health problems in people. Acute exposures and effects are uncommon. People can get this kind of exposure by being exposed to a very strong beta source coming from an abandoned industrial tool or instrument. The chronic exposures and effects are more common. People get chronic health problems when they are exposed to low levels of beta radiation over a long period. These kinds of effects develop at a slow rate and can take between five to 30 years to manifest. Cancer is the main chronic health effect that comes from
Radiation Exposure
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beta radiation. The risk of cancer increases as the dose increases. Carbon-14 is a type of beta emitter that travels throughout the entire human body. However, iodine-131 concentrates mainly in the thyroid gland and increases the risk factor of getting thyroid cancer and other disorders. Strontium-90 is another beta emitter that collects in the bone and teeth. Too much of this beta emitter can cause health problems in those specific areas of the body. Techniques to Minimize the Dosage of Radiation in Cancer Diagnosis and Treatment The fact that ionizing radiation causes cancer has caused many researchers and healthcare professionals to question the safety in the use of X-rays in diagnosis. Although the use of diagnostic X-rays has saved many lives, people are taking precautionary measures to lower the risk of possible cancer from Xrays. Oppenheimer explains that new tools have been developed that uses ultrasensitive x-ray films. This enables much smaller doses of radiation to be used. Another precautionary measure that has been used recently is that routine and massive x-ray screening is only used when scientists and diagnosticians deem it necessary. In one specific example, women are no longer given routine mammography and xeroradiography unless they are in a specific high-risk group, such as if a woman has a history of female relatives with breast cancer. Thus, the use of X-rays to detect breast lumps has decreased for younger age groups. Although X-rays are still widely used in clinical settings, new techniques are being made to use only the minimal amount of radiation to the patient. According to the Neurological Encyclopedia, two new radiation techniques that use minimal amounts of radiation have been developed to treat brain tumors. One of the techniques is called three-dimensional conformal radiation therapy. In this process, multiple beams are arranged so that they match the shape of the tumor. The second technique is called stereotactic radiosurgery. This technique uses gamma knives and cyberknives to specifically irradiate specific portions of the brain tumors. Gamma knives use focused beams, while cyberknives use many specific pinpoint beams that come from one source of irradiation. New radiation techniques are continuing to
1464 Radiologist be made to diagnose and treat human cancers while minimizing the dosage of irradiation. Radiation Causes Damage to DNA The major damage produced by radiation is to the DNA. Research and studies have shown that when DNA is exposed to radiation, the mutation frequency of DNA substantially increases. In his book, Cancer: A Biological and Clinical Introduction with Cancer Prevention Guide, Oppenheimer explains that there are basically three kinds of damage that occur: breaks in single strands of DNA, doublestrand breaks of the DNA, and the alteration of bases in the DNA. When the double-stranded DNA breaks, the entire DNA molecule becomes fragmented. Single-strand breaks cause the least problems because they can be efficiently repaired. Double-strand breaks can also be repaired; however, the repair of doublestrand breaks often results in translocation (different chromosomes exchange different fragments). If a particular translocation leads to the activation of oncogenes, cancer can arise. Oncogenes are genes that induce cancer. The alteration of bases is the major cause of radiation-induced cancer. Radiation causes cancer. Whether it is excessive medical X-rays or excessive exposure to the sun, precautions must be taken to lower the risk of getting too much radiation. Any kind or form of radiation can cause damage to the DNA by changing its informational content and activating the oncogene. This alteration, as a result, can cause the local uncontrolled growth of cells (benign tumor) and lead to a more dangerous form that spreads out to other parts of the body. The spreading out of cancer cells to distant sites in the body is called malignant tumor (cancer). SEE ALSO: Base Excision Repair; Brain Diseases; Breast
Diseases; Cancer (General); Cancer Radiation Therapy; Chromosome; DNA Repair; Genetic Disorders; Mismatch Repair; Point Mutation; Radiology. BIBLIOGRAPHY. Steven B. Oppenheimer, Cancer: A
Biological and Clinical Introduction with Cancer Prevention Guide (Pearson Education, 2004); “Radiation Definition,” Neurological Encyclopedia, www.answers. com (cited January 2007); U. S. Environmental Protection Agency, “Understanding Radiation Beta Particles,”
www.epa.gov (cited January 2007); U. S. Environmental Protection Agency, “Understanding Radiation Gamma Rays,” www.epa.gov (cited January 2007); Wolfram Research, “Alpha Radiation,” http://scienceworld.wolfram. com (cited January 2007). Joanne H. Lim University of Southern California
Radiologist A radiologist is a qualified healthcare professional who works in radiography. With radiography first being developed in 1895 by the German professor of physics, Wilhelm Conrad Röntgen, because of the technical problems involved in the use of radiation, it became necessary to have special training for people who use the equipment. This training has become even more important with the development of computerized axial tomography (CAT scan), ultrasound, magnetic resonance imaging (MRI), and nuclear medicine. With the need for trained radiologists in World War I, numbers of Allied doctors were quickly trained in the technique with the Society of Radiographers being established in 1920. The publication of Elementary Physics by Gilbert Stead in 1924 helped provide many medical students with information on radiology and persuade many of them to see radiology as a new field of medical endeavor. In the United States it is necessary for diagnostic radiologists to complete five years of postgraduate training after their four years of medical school. The first of these postgraduate years involves a preliminary internship in medicine and/or surgery, after which there is a four-year diagnostic radiology residency. During these last four years, trainees have to pass oral and written national examinations, with two separate written examinations required for the trainee to receive an accreditation certificate from the American Board of Radiology. In the United Kingdom, the training required to become a diagnostic radiologist include a medical degree followed by accreditation by the Royal College of Radiologists in London. It was founded in 1939 and its membership includes oncologists as well as radi-
Radiology
ologists. It publishes the Clinical Radiology Journal monthly and Clinical Oncology every two months. Research is also coordinated at the British Institute of Radiology, which was founded in 1897 and has one of the most extensive research libraries for radiologists in the world. It publishes The British Journal of Radiology monthly and Imaging quarterly. Radiology training in Australia and New Zealand involves the completion of a six-year medical degree, followed by at least two years of hospital residency as an intern and then as a junior house medical officer, followed by five years of which one of these can be a fellowship. There is then a series of two written examinations covering anatomy and physics in regard to radiology (after one year) and then clinical and diagnostic radiology and pathology in the fourth year. The trainee can then apply for accreditation by the Royal Australian and New Zealand College of Radiology. In other countries, there are similar systems of accreditation. SEE ALSO: Radiology; Roentgen, Wilhelm. BIBLIOGRAPHY. The British Institute of Radiology, www.
bir.org.uk; Eric J. Hall, Radiology for the Radiologist, 3rd ed. (Lippincott, 1988); William S. C. Hare, Clinical Radiology for Medical Students and Health Practitioners (Blackwell Science Asia, 1999); Royal College of Radiologists, www. rcr.ac.uk.
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through, there were attempts to produce film of moving objects in hope that radiology might be able to depict function. However, this led to technical difficulties because of the very much higher doses of radiation required for moving film, preventing this technique from being developed. However, the X-rays provided such a breakthrough in medical technology that within 10 years, radiology was being used in many parts of the Western world. As a result, Röntgen received the first Nobel Prize in Physics in 1901, with the first English-language book on chest radiography being published in 1905. Essentially, the X-ray machine provides an image whereby doctors can evaluate bony structures and soft tissues, as well as spotting foreign bodies in tissue. This led to the radiodiagnosis becoming common with the ability of X-rays to penetrate tissue, managing to show up some substances to fluoresce, as well as preserving the situation with a photograph. With the X-rays being able to penetrate tissue, the radiation is absorbed differentially, dependant on the densities of the tissues concerned. As a result, the photograph taken can show a notable contrast between the images of structures and organs, even though these X-rays do not differentiate on their images between adjacent areas of soft tissues. The development of X-ray techniques and technologies by radiographers has meant that contrast
Justin Corfield Geelong Grammar School, Australia
Radiology Radiology is a branch of medicine whereby radiologists use medical imaging technologies to diagnose and sometimes treat particular diseases. Originally, it was largely connected with the use of X-ray machines and similar devices to photograph parts of people to assist doctors in diagnosis, but is not the radiology involving a wider range of machines and imaging devices. Radiology began after a German professor of physics, Wilhelm Conrad Röntgen, discovered X-rays in his laboratory in the University of Würzburg on November 8, 1895. Within several months of this medical break-
The work of radiographers has also changed from simply photographing a patient to providing a more detailed diagnosis.
1466 Radiology media can be injected into blood vessels and the effect of them will be seen in X-rays showing the media in arteries, veins, kidneys, and urinary tracts. In the first 20 years following the discovery of Xrays, the role of radiologists changed dramatically with the X-ray machines being used to treat fractures of bones and also for the localization of foreign bodies in tissue, especially bullets lodged in people’s tissue during World War I. The work on locating and extracting bullets led Maria Curie to push for the mobile radiography units to be established to treat soldiers, with her personally providing radon tubes for the French Army. In 1920, the Society of Radiographers was formed, and radiology continued to develop in many ways. In 1937, a patient suffering from leukemia was treated at the University of California, Berkeley, using radioactivity to treat cancer for the first time. In the same year, Joseph Gilbert Hamilton started to use radioactive iodine for the diagnosis and treatment of thyroid disease. By the 1950s, the work of radiographers had changed to include work on the electronic method which was devised to intensify the image with an image intensifier, overcoming earlier technical difficulties to make cineradiography become more common. Photographic techniques also improved with the single-coated photographic plates being replaced by double-coated photographic film, with sufficiently good definition, allowing the photographs to be taken at a higher speed, reducing harmful radiation techniques. The developing of photographs has also been sped up with automatic processors able to develop dry film in less than 90 seconds. This, in turn, has meant that if radiographers spot anything serious, they are able to take another photograph or set of photographs almost straightaway without the cost of bringing the patient back at a later time, as previously happened. A new X-ray device was introduced during the 1970s which revolutionized the work of radiographers. The computerized axial tomography (CAT scan) was devised by the British electrical engineer Godfrey N. Hounsfield and South African-born U.S. physicist Allan Cormack. This measures the attenuation of X-rays entering the body from different angles. Collating these measurements, a computer then reconstructs the organ in three dimensions which allows soft tissue such as liver and kidneys to be easily differentiated in the images that are provided. This led to Hounsfield and Cormack winning the Nobel
Prize for Physiology or Medicine in 1979. These CAT scanners are now used in large hospitals and medical centers around the world. At the same time as the CAT scanners, there was a development in ultrasound to visualize soft tissue structures. An advantage of the use of ultrasound is that unlike normal X-ray radiography, CAT scans, and the recent developments in nuclear medicine imaging techniques, the ultrasound does not use ionizing radiation and therefore is far safer to use. Ultrasound is generally used where other methods may cause problems, such as diagnosing any potential problems in unborn children. However, the major change has come in the added use of the radiation generated for the treatment of cancer and also other conditions. The next development in work in radiography is with the emergence of magnetic resonance imaging (MRI), sometimes called nuclear magnetic resonance (NMR), with radio waves being beamed into an individual who is being subjected to a powerful magnetic field. As different atoms in the body absorb the radio waves at varying frequencies, a computer can collate the data and then construct images of internal parts of the patient. This has been developed further in nuclear medicine with the patient swallowing particular radioactive tracers such as Technetium-99m, Iodine123, Iodine-131, and Xenon-133. There is also positron-emission tomography (PET) scanning whereby particles of antimatter are injected into a body which is then scanned. While the work of radiographers has changed considerably with the development of new machines, the same aim of the original X-ray machine developed by Röntgen remains, with the branch of medicine including radiography becoming hugely important, with the developments making it not only faster and more accurate, but also with the ability to cope with moving images and three-dimensional images. SEE ALSO: Radiologist; Roentgen, Wilhelm. BIBLIOGRAPHY. Eric J. Hall, Radiology for the Radiolo-
gist, 3rd ed. (Lippincott, 1988); William S. C. Hare, Clinical Radiology for Medical Students and Health Practitioners (Blackwell Science Asia, 1999). Justin Corfield Geelong Grammar School, Australia
Radon Radon is a colorless, odorless gas (one of the “noble gases”) in its natural form, and is a chemical element in the periodic table which uses the symbol “Rn” and has an atomic number 86. Being 7.5 times heavier than air and 100 times heavier than oxygen, it liquefies at minus 61.8 degrees C (minus 80 degrees F) and freezes at minus 71 degrees C (minus 96 degrees F). Radon is generated by the radioactive decay of radium, from which it gets its name. It is very rare in nature because of the short life of its isotopes, and because radium itself is rare. It occurs naturally in the Earth’s atmosphere but at extremely low levels, and occurs near the ground as a result of seepage from rocks and soils. It can often be found in radon-rich water, and some health spas such as those at Misasa, Tottori, Japan, where the water is rich in radium, exuding radon and believed to have special powers. Overall, radon atoms have an extremely stable electronic configuration which consists of eight electrons in their outer shell. These account for the characteristic chemical inactivity of the element, making the radon gas regarded as one of the “noble gases.” However, chemically, radon is not completely inert. In 1962, scientists found the existence of a compound, radon difluoride, which is, apparently, far more stable chemically than compounds formed from krypton and xenon, the other reactive “noble gases.” However, the short life of radon and the energy of its radioactivity have combined to make it difficult to investigate the properties of these radon compounds. Natural radon consists of three isotopes, with each one coming from the three natural radioactive-disintegration series: the uranium, thorium, and actinium series. The longest-lived isotope, radon-222 (which has a half-life of 3.823 days), was discovered in 1900 by the German chemist Friedrich Ernst Dorn, arises in the uranium series. He called it “radium emanation,” and some scientists reserve the name radon for this isotope to differentiate it from the two natural isotopes, which they call thoron and actinon as they originate in the thorium and the actinium series, respectively. Eight years later, William Ramsay and Robert Whytlaw-Gray named it “niton” from the Latin nitens (“shining”), and determined that it was the heaviest known gas. It has also been called “radon” since 1923, taking the name from “radium.”
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The radon-220 (thoron; with a half-life of 51.5 seconds) was first observed in 1899 by the British scientists R. B. Owens and Ernest Rutherford (later Lord Rutherford), who, during experiments, both noticed that some of the radioactivity of thorium compounds could actually be blown away. In 1904, the radon-219 (actinon; with a half life of 3.92 seconds) was found independently by the scientists Friedrich O. Giesel and André-Louis Debierne to be associated with actinium. Since then, more than a dozen artificial radioactive isotopes of radon have been isolated. It was not until the 1980s that the naturally occurring radon gas was recognized as being a potentially serious health hazard. Prolonged use of radon-rich spas are now regarded as unhealthy, and it is also dangerous to live in buildings in areas where radon occurs naturally, especially over geological formations where there are significant deposits of uranium minerals. Because of its weight, radon gas generally tends to collect in the foundations of buildings or basements and sometimes makes its way into the piping of building which can affect places that are poorly ventilated. Medical problems resulting from exposure to radon gas over a number of years can lead to a massively increased risk of lung cancer. This has led medical researchers to believe that radon is now the single major cause of lung cancer among nonsmokers in the United States. In addition to its effects as a health hazard, there are also beneficial medical uses of radon which is prepared synthetically for medical and research purposes. It is usually generated from radium which is kept as a liquid in a glass vessel from which radon can be easily pumped off when required, and then stored in small tubes. These can then be used as a source of the penetrating gamma radiation which comes from a decay product of radon, bismuth-214. These tubes are used by researchers in radiotherapy. SEE ALSO: Environmental Health; Radiation Exposure. BIBLIOGRAPHY. Sigurdur Helgason, The Radon Transform
(Birkhauser, 1999); Steven B. Oppenheimer, Cancer: A Biological and Clinical Introduction with Cancer Prevention Guide (Pearson Education, 2004).
Justin Corfield Geelong Grammar School, Australia
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Ramsay Hunt, James (1872/74–1937) James Ramsay Hunt (birth years reported to be both 1872 and 1874) was born in Philadelphia, Pennsylvania. He is known for his significant work in neurology. Because of his research in the field, a number of neurological disorders contain his name; consequently, Hunt has frequently been labeled as the preeminent neurologist of the 20th century. Hunt obtained his M.D. from the University of Pennsylvania School of Medicine in 1893. He then studied in notable universities around the world, including those in Paris, Vienna, and Berlin. From 1900 to 1910, he was employed by Cornell University Medical School, where he researched corpus striatum and the extrapyramidal system disorders. During World War I, Hunt served as a lieutenant colonel in the Army Medical Corp. He married Alice St. John Nolan of Springfield, Illinois, with whom he had two children: Alice and John Ramsay Hunt, Jr. His son became involved with Central Intelligence Agency (CIA) intelligence operations and his daughter became an accomplished and noted musician and author. In 1924, Hunt was named a full professor of neurology at Columbia University College of Physicians and Surgeons. He documented three discrete neurological syndromes: herpes zoster oticus with peripheral facial palsy, a disease that affects the facial and hearing nerves and is also known as Ramsay Hunt’s syndrome; carotid artery occlusion, which is considered the second Ramsay Hunt syndrome; and dyssynergia cerebellaris progressive, which is considered the third Ramsay Hunt syndrome. Hunt added significantly to medical understanding of Parkinson’s disease with his research illuminating the structure and function of the basal ganglia. Hunt also served as the consulting neurologist and senior attending neurologist at the Neurological Institute of New York from 1914 until 1937. Hunt published 30 volumes of The James Ramsay Hunt Case Books (Columbia University Press), detailing his medical experiences with over 5,000 private patients from 1903 through 1937. Patients most frequently experienced neurasthenia, psychiatric diagnoses, neuropathies, manifestations of neurosyphilis, migraine, and epilepsy. The volumes also contained
letters, photographs, and poetry from the patients, as well as Hunt’s drawings. From a contemporary perspective, these volumes allow modern-day medical personnel to understand how neurology was understood and practiced in Hunt’s era. Hunt died on July 22, 1937, in Katonah, New York. SEE ALSO: Neurological Diseases (General); Neurologist;
Neurology.
BIBLIOGRAPHY. “Alice Hunt Sokoloff,” New York Times,
http://query.nytimes.com/gst/fullpage.html?res=990DE 2DB103AF932A05756C0A9609C8B63 (cited May 2007); “James Ramsay Hunt,” WhoNamedIt?, www.whonamedit. com/doctor.cfm/2009.html (cited May 2007); “The James Ramsay Hunt Case Books,” IngentaConnect, http://www. ingentaconnect.com/content/tandf/jhin/2003/00000012/0 0000001/art00004 (cited May 2007). Kelly Boyer Sagert Independent Scholar
Randomized Clinical Trial A randomized clinical trial is a research design regarded as the highest level of evidence in assessing the outcome and effect of therapeutic interventions. Such trials are prospective studies that evaluate the short-term or longitudinal outcomes of two groups. Both groups are selected randomly and properly allocated to treatment groups; thereby, distributing equally any preexisting confounds that can affect the outcome of interest. Theoretically, characteristics of the allocated groups at baseline are considered the same before the trial commences and differences observed between the two groups following treatment intervention at the end of the trial are likely to be attributed to the type of treatment administered. Design issues are many, but proper blinding techniques, randomization, exclusion/inclusion criteria, and measures to minimize attrition are paramount. Two main types of randomized clinical trials are performed and are known as the crossover design and the parallel design. The latter entails two independent groups, a control group and an intervention group, who receive two different treatments and are observed through a specified time interval and their outcomes
Rare Diseases
Randomized clinical trials are prospective studies that evaluate the short-term or longitudinal outcomes of two groups.
are noted. Conversely, a crossover design represents two paired groups that receive the same treatment at one point or another, but at alternating times. In the crossover design, the main interest is to measure the treatment effect and determine the existence of a sequential or period effect. Also, concern rests with any residual or carry-over effect the previous treatment may have on the participant. If such a factor is an issue, a washout or adaptation period may be incorporated to minimize the effects of the previous treatment. However, a proper design is constructed so that each treatment is administered in a similar fashion. Furthermore, in a crossover design, comparisons are made within-subjects, whereas in a parallel design they are conducted between-groups. Also, proper power analysis in randomized clinical trials can be conducted beforehand to determine the size of the sample groups, but an ideal sample size may not always be feasible due to the ethical implications and the placebo exposure that may dismay potential participants in enrolling in the trial. In addition, due to the theoretical comparability of the two groups in randomized clinical trials, such designs possess strong internal validity but the ability to generalize or the strength of external validity in such designs is severely limited if the trial was based on a very homogenous group. If proper randomization is not properly conducted in a randomized clinical trial, such a trial is considered
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quasi-randomized. In such a trial, the generation of allocating the subjects could entail bias. For example, quasi-randomization may be present if the subjects are assigned based on their patient record, social security number, or odd or even days of the week. In the event that randomization is not performed but control groups are present, the trial is regarded as a controlled clinical trial; however, such a study design lacks the strength of a properly conducted randomized clinical trial by possessing potential confounds that may affect the true effect size of the interventions being observed. Strong internal validity is essential in a properly conducted randomized clinical trial in order to properly measure the effect size of the intervention. To avoid or minimize the occurrence of potential confounds or biases due to inappropriate study design, implementation, and analyses, the CONSORT statement developed by numerous international healthcare specialists provides certain guidelines to properly conduct and assess randomized clinical trials. SEE ALSO: Clinical Trial; Crossover Study; Double-Blind-
ed Study; Prospective Study.
BIBLIOGRAPHY. Centre for Evidence Based Medicine,
“Levels of Evidence and Grades of Recommendations,” www. cebm.net/levels_of_evidence.asp (cited October 2006); David Moher, et al., “The CONSORT Statement: Revised Recommendations for Improving the Quality of Reports of Parallel-Group Randomized Trials,” JAMA (v.285: 2001);�� Kenneth F. Schulz, et al., “Empiral Evidence of Bias: Dimensions of Mquality Associated with Estimates of Treatment Effects in Controlled Trials,” JAMA (v.273, 1995). Dino Samartzis, DSc, MSc, Dip. EBHC Harvard University and Erasmus University
Rare Diseases Rare diseases, also known as orphan diseases, generally have a very low occurrence. In the United States, fewer than 200,000 cases of such illnesses take place. In Europe, about 5 in 10,000 individuals are affected by a rare disorder in a year’s time. This type of disease is so uncommon that a practicing physician will hardly
1470 Rare Diseases see about one or two such cases a year. Rare diseases, however, may be prevalent differently in various populations. For instance, they may be more common in one community compared to another depending on that culture’s activities or lifestyle. Religious beliefs also play a role if the group is affected as a whole. At present, there are about 5,000 to 8,000 known types of rare diseases. Many different reasons can give rise to this type of a condition. Toxicity to poisonous agent such as arsenic or ingestion of an unknown substance may give rise to such a condition. Rare disease that is originated from infections and genetic linkages may be life threatening, and affected individuals have a potential risk of passing on the disease to the next generation. Toxic shock syndrome, toxoplasmosis, congenital adrenal hyperplasia, and Tay-Sachs disease are rare diseases that are discussed here. Because these conditions are so rare, the population as a whole is usually not affected. On the other hand, the low prevalence of rare diseases has resulted in ignorance of research and lack of enough information for a long time. Toxic Shock Syndrome Toxic shock syndrome is a rare illness due to a bacterial infection. The bacteria staphylococcal or streptococcal cause an infection by releasing toxins in the patient’s bloodstream. Bacterial infection can be due to various reasons. Superabsorbent tampons were linked to staphylococcal infections in the 1980s and their sale was ceased. Streptococcus lives on human skin and may find entry into the blood stream through a lesion. Infection from this bacterium is usually observed after a skin cut, wound, or a surgical incision. Toxic shock syndrome is a life-threatening condition because it possesses a threat for a severe drop in the patient’s blood pressure. It can prove to be a fatal condition if left untreated. Toxoplasmosis Toxoplasmosis is a type of infection caused by the parasite Toxoplasma gondii. This parasite has a potential of infecting all types of warm-blooded animals—humans, birds, and mammals. However, cats serve as the main host source of infection. Pregnant women and immunocompromised (those with weakened immune system) individuals are most susceptible. Toxoplasma gondii is found in cat litter, hence, pregnant women are advised not to be around cats. If they have a pet, it is recommended that they do not change cat litter un-
der any circumstances. If proper precautions are not taken, then toxoplasmosis has a 40 percent chance of being passed on to the fetus. If placental transmission of infection to the fetus occurs, then it will give rise to a severe condition known as congenital toxoplasmosis. Approximately 1 percent of pregnant women and about 1,000 babies in the United States suffer from this condition every year. Immunocompetent patients suffering from toxoplasmosis experience difficulty in the central nervous system. In the United States alone, about one in five individuals are affected by this type of infection. Most people do not experience any initial symptoms until the immune system reacts. Occasionally, a person may get toxoplasmosis by ingesting undercooked or raw meat. Eating contaminated vegetables or soil can also provide a way for parasites to enter the patient’s body. If symptoms are not to be seen, then the parasite is probably residing in a dormant stage in the brain or muscle tissue without causing other health problems. However, the infection may spread, giving rise to a systemic (throughout the body) infection. A physician will send out for blood test that can confirm presence of antibodies for toxoplasma. Diagnosis may also be made by ordering lab tests for infected tissue, bone marrow, or sputum. Treatment for patients with weakened immune system should start a few weeks after the symptoms disappear. However, treatment for pregnant women who are infected should begin as soon as possible. Congenital Adrenal Hyperplasia Congenital adrenal hyperplasia is an autosomal recessive disorder. It affects the cortisol synthesis that is controlled by adrenal glands by lowering its activity. An affected person has an absent enzyme that will otherwise play an important role in the cortisol production pathway. It is a rare genetic condition present at birth. Because many enzymes participate in cortisol synthesis, deficiency of a single enzyme will lead to reduced production of aldosterone (hormone that regulates osmolarity, i.e., salt and water balance). Moreover, it also gives rise to an overproduction of androgens or male sex hormones. Tay-Sachs Disease A rare inborn disease, Tay-Sachs is due to the deficiency of the enzyme hexosaminidase A. The enzyme
Raynaud’s Disease
is responsible for fat breakdown in brain and nerve cells. Because Tay-Sachs patients lack this enzyme, they suffer from a fat buildup in their central nervous system and because it is an inborn condition, most children die by age 4 or 5. Those who survive may be ill with severe paralysis and are at risk of an early death. However, it is a recessive disorder and so a child will only be at risk if both parents are carriers of the recessive trait. Even then, the child has to inherit both the recessive copies to be actually affected by Tay-Sachs. SEE ALSO: Genetic Disorders; Parasitic Diseases; Staphylo-
coccal Infections; Streptococcal Infections; Tay-Sachs Disease; Turner’s Syndrome; Viral Infections; Women’s Health. BIBLIOGRAPHY. American Medical Association Fam-
ily Medical Guide, 4th ed. (Wiley, 2004); Europa–Public Health, “Rare Diseases: What Are Rare Diseases? Why Do Rare Diseases Need Specific EU Support? What Are the Objectives and Issues According to DG SANCO [The Health & Consumer Protection Directorate General]?” http://ec.europa.eu/health/ph_threats/non_com/rare_ diseases_en.htm (cited January 2007); Eurordis (European Organisation of Rare Diseases), “Rare Diseases: Understanding This Public Health Priority,” www.eurordis. org/IMG/pdf/princeps_document-EN.pdf (cited January 2007); Martins S. Lipsky, American Medical Association: Concise Medical Encyclopedia (Random House Reference, 2007); National Institute of Health Office of Rare Diseases, “Rare Diseases Terms,” http://rarediseases.info. nih.gov/asp/diseases/diseases.asp (cited January 2007); USA Today: Health Scout, “Health Encyclopedia: Diseases and Conditions: Toxoplasmosis,” www.healthscout.com/ ency/68/708/main.html (cited January 2007); Wikipedia: The Free Encyclopedia, “Rare Disease,” http://en.wikipedia. org/wiki/Rare_disease (cited January 2007). Jinal Mehta University of Missouri
Raynaud’s Disease Raynaud’s disease is a reversible ischemic event that takes place in the extremities of the body in response to various stimuli such as exposure to cold and stress. It is named after the French physician Maurice Raynaud.
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Raynaud’s disease is most often a benign condition and may disappear in a substantial proportion of subjects. The prevalence of the disease is approxamately 5 to 6 percent; however, the prevalence varies in populations. The disease is more common in females than males. The exact etiology of Raynaud’s disease is undetermined; however, many of the risk factors have been established. In addition to being a triggering factor for the disease, cold temperatures also appear to be an etiological factor in the pathogenesis of the disease. The exposure to cold temperatures trigger the loss of heat from the body; the small arteries in the extremities are narrowed and thus have a restricted blood supply; this leads to preservation of the body’s temperature for other vital organs. In Raynaud’s disease, this normal process is exaggerated, further leading to excessive constriction of arteries and thus vasospasm, leading to interruption of blood flow to the extremities and hence a pallor of the skin, cyanosis (due to desaturation of hemoglobin), and numbness. As the arteries return to their normal dilated state, an increased blood flow occurs (hyperema), and hence, redness of skin (erythema), followed by pain in the extremeties. Although most typically noted in the fingers, the circulation of the toes, ears, nose, and tongue are also frequently affected. Emotional stress alone can cause an episode of Raynaud’s. If the cause of the disease is attributed to another disorder (most commonly an autoimmune disorder), the name of the condition is referred as Raynaud’s phenomenon or secondary Raynaud. Autoimmune diseases include rheumatoid arthritis, systemic lupus erythematosis, Sjögren’s syndrome, and scleroderma. Other diseases include hepatitis B and C; neoplasm’s such as lymphoma and myeloma; and metabolic syndromes such as acromegaly. Other potential causal or triggering factors can be found in the workplace such as the use of vibrating tools; this is commonly seen in the food processing industry. Neurovascular syndromes such as carpal tunnel syndrome may exacerbate symptoms and should be considered particularly in patients with asymmetrical digital lesions. In some, the disease may be the first sign of a connective tissue disease (CTD) such as scleroderma. Risk factors for developing CTDs include the severity of the disease at onset, a positive test for antinuclear antibodies, and age at onset. An abnormal nailfold capillary
1472 Reflex Sympathetic Dystrophy pattern is strongly associated with the subsequent development of a CTD. Some studies have suggested that risk factors for Raynaud’s phenomenon differ between men and women, for example, age and smoking are associated with the disease in men only, while the associations of marital status and alcohol use with the disease are observed in women. Diagnosis of the disease and classification into primary and secondary is made using a criteria system. The criteria for primary disease include symmetric attacks, the absence of tissue necrosis, ulceration or gangrene, the absence of a secondary cause, negative antinuclear antibodies, normal nailfold capillaroscopy, and a normal erythrocyte sedimentation rate. Secondary disease is characterized by an age of onset of more than 30 years, painful and asymmetric attacks, ischemic skin lesions, positive antinuclear antibodies, capillaroscopic abnormalities, and clinical features which suggest CTDs. Diagnosis is made using history and examination, chest radiograph and barium esophagram, pulmonary function tests, antinuclear and anticentromere antibodies test, cryoglobulins test, and nailfold capillary microscopy (technique used in childhood and adults for morphofunctional study of peripheral microcirculation). Treatment for Raynaud’s disease includes peripheral sympathectomy which improves perfusion to ischemic digits and enables amputation to be avoided. The ingestion of omega-3 fatty acids could benefit patients with Raynaud’s phenomenon as fatty acids induce a favorable vascular response to ischemia. Ingestion of fish oil improves tolerance to cold exposure and delays the onset of vasospasm in patients with primary Raynaud’s disease. Management of the disease includes physical therapy, avoidance of triggers, and a variety of medications, depending on the disease severity. For primary and uncomplicated secondary disease, calcium channel blockers (e.g., nifedipine), particularly ones that cause vasodilatation, are used; angiotensin converting enzyme inhibitors such as losartan and prostaglandins analogues may also have benefit. Other agents including alpha receptor blockers, for example, prazosin; sympatholytic agents, for example, reserpine; and selective serotonin-reuptake inhibitors, for example, fluoxetine may be useful. Secondary Raynaud’s is treated according to the underlying disorder. Prognosis for primary Raynaud’s syndrome is good; however, patients with secondary
symptoms require greater care and treatment strategies to avoid further complications. SEE ALSO: Connective Tissue Disorders. BIBLIOGRAPHY. Peter Beighton, ed., McKusick’s Heritable
Disorders of Connective Tissue (C.V. Mosby, 1993); J.A. Bloc and A. Sequeira, “Raynaud’s Phenomenon,” Lancet (v.357/9273, 2001).
Farhana Akter Independent Scholar
Reflex Sympathetic Dystrophy Reflex sympathetic dystrophy (RSD), also known as complex regional pain syndrome (CRPS), is a disease that affects regions of the upper and lower extremities. It involves pain, decreased motion, swelling, skin changes, increased sweating, abnormal hair growth, and weakening of the bones of the affected area. This disease tends to develop after there has been a physical insult to the body. People of any age or gender can develop RSD, but it is most common in females who are between the ages of 30 to 60. Most often, the inciting events of injury to soft tissue and bone are the cause of developing RSD, but there may also be a genetic predisposition. This genetic component may indicate a connection to the immune system, and knowing a patient’s genetic tendency could help determine how well he or she will respond to treatment. The sympathetic nervous system is involved in the fight or flight response, and its stimulation can result in physiologic changes such as increased heart rate, sweating, and increased blood flow to muscles and skin. The exact physiologic development of RSD remains unclear, but it appears to develop when the nerves damaged by a physical insult attempt to regenerate, and do so along the course of the sympathetic nervous system. This forms a sort of reflex arc, and results in the renewed nerves being affected by the sympathetic nerves with increased sensitivity to the chemicals they release. This is thought to cause the pain patients experience. There are three stages of symptoms with this illness. Stage I usually develops within hours or days
of an acute injury. The symptoms of this stage can involve pain, burning sensations, an increased sensitivity to touch or temperature, swelling, slight bone weakening, and changes in skin color. Stage II usually occurs three to six months following the injury that caused the disease to develop. This stage can consist of further swelling, muscle wasting and spasms, increased pain, burning sensation, increased sweating, and skin thickening. About six months after the initial injury, the disease advances to stage III. This period involves severe shortening of muscles causing lack of joint movement, deformities, severe bone weakening, brittle nails, breakdown of skin, and intolerance to temperature extremes. Diagnosis and treatment The diagnosis of RSD is complex and includes the use of many different tests. In early stages of the disease, assessment of the physiologic response of the nervous system can be very useful. The tests involved in this analysis include evaluating the amount of sweat produced at rest as well as after electrical stimulation of the skin, and the temperature of the skin at rest. As the disease progresses to later stages, tests such as X-rays and other bone scans can help determine the health and strength of the bones. The diagnosis of RSD is very probable if injection of a nerve with an anesthetic causes a rapid decrease in pain and sensation problems. This test identifies the particular nerve causing the symptoms. There are a variety of modalities that can be used to treat RSD. They include drug therapy, physical and occupational therapies, stress management and other lifestyle changes such as exercise and smoking cessation, and invasive nerve blocks or stimulation. Whatever modality is used, the key is to first use whatever works quickly in an attempt to prevent progression of the disease. If treatment can be started in stage I of RSD, outcome is often better than when the disease is left untreated until later stages. Drug therapies that are used include antiinflammatory agents, antidepressants, topical pain relievers, and other drugs that help reduce neuropathic pain. Daily physical and occupational therapy are useful for preventing the muscle wasting and shortening that occurs with progression of RSD. It is important to start these modalities early while there is still healthy muscle tissue. These therapies are also useful in later stages to regain the use of muscles that are damaged.
Refractive Errors
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In this same fashion, stress reduction and exercise are important in treating RSD because they help promote healthy living, and are also useful in preventing progression of the disease. Surgical interventions such as injections and nerve blocks are useful treatments, but should not be instituted unless the previous conservative therapies have failed. Prognosis The best outcome in patients with RSD occurs when they have been treated with a combination of drug and physical therapies. The disease is not life threatening and will not progress any further after a certain point. However, recurrences can occur, and some patients experience episodes similar to the RSD when they have been exposed to an offending agent such as an extreme cold or hot temperature. There is no way to prevent RSD from occurring, but it is possible to try to avoid the causative offending agents and conditions. Secondary prevention is also realistic when complying with the treatment regimen to relieve pain and restore muscle strength to avoid a recurrence or progression of the symptoms. SEE ALSO: Muscular Dystrophy; Pain. BIBLIOGRAPHY. Goetz, “Anatomy of the Autonomic Ner-
vous System,” in Textbook of Clinical Neurology Online, 2nd ed. (Saunders, 2003); Rolland P. Gyulai, et al. “Reflex Sympathetic Dystrophy,” First Consult Online (cited August 2005); Robert P. Sheon, “Reflex Sympathetic Dystrophy (Complex Regional Pain Syndrome) in Adults,” Up to Date Online 14.2. Ahmed S. Samad, M.D. Hoffmann-La Roche Inc.
Refractive Errors Refractive error is a term used to describe an inability of images to focus properly on the retina of the eye. It is the most common cause of blurred vision, and may be a treatable component of poor vision in many patients. These errors are inherited in a complex manner involving many variables. Emmetropia is absence of refractive error and ametropia is the presence of refractive error. Some of the most com-
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mon refractive errors include presbyopia, myopia, and hyperopia. The loss of accommodation that comes with aging is called presbyopia. A person with emmetropic eyes will begin to notice inability to read small print or discriminate fine, close objects at about age 44 to 46. These symptoms increase until about age 55, when they stabilize but persist. When the image of distant objects focuses in front of the retina in the unaccommodated eye, the eye is myopic, or nearsighted. If the eye is longer than average, the error is called axial myopia. As the object is brought closer, the image moves closer to the retina and comes into sharper focus. The point reached where the image is most sharply focused on the retina is called the far point. The myopic person has the advantage of being able to read at the far point without glasses even at the age of presbyopia. A high degree of myopia results in greater susceptibility to degenerative retinal changes, including retinal detachment. Concave spherical (minus) lenses are used to correct the image in myopia. These lenses move the image back to the retina. Hyperopia (farsightedness) is the state in which the unaccommodated eye would focus the image behind the retina. If hyperopia is not too great, a young person may obtain a sharp distant image by accommodating. The young hyperopic person may also make a sharp near image by accommodating more— or much more than one without hyperopia. This extra effort may result in eye fatigue that is more severe for near work. The degree of hyperopia a person may have without symptoms is variable. However, the amount decreases with age as presbyopia increases. If the hyperopia is too high, the eye may be unable to correct the image by accommodation. The hyperopia that cannot be corrected by accommodation is termed manifest hyperopia. The degree of hyperopia overcome by accommodation is known as latent hyperopia. A moderately farsighted person may see well for near or far when young. However, as presbyopia comes on, the hyperope first has trouble with close work—and at an earlier age than the nonhyperope. Finally, the hyperope has blurred vision for near and far and requires glasses for both. Spectacles continue to be the safest method of refractive correction. Alternatives include contact lenses, intraocular lenses, and keratorefractive surgery.
SEE ALSO: Eye Care; Ophthalmologist; Ophthalmology;
Optometrist.
BIBLIOGRAPHY. D. M. Albert and F. A. Jakobiec, eds.,
Principles and Practice of Ophthalmology, 2nd ed. (Saunders, 2000); D. Vaughn et al., General Ophthalmology, 15th ed. (Appleton & Lange, 1999). Nakul Gupta Ross University
Refugee Health The health of refugees and internally displaced people depends on the availability of basic health services, immunization programs, health education, and adequate living conditions defined by shelter, food and nutrition, water and sanitation, education, and environment. Health and nutrition services for refugee populations are divided into five categories: immunization, nutritional support, control of communicable diseases, reproductive health services, chronic illness, mental health, and public health surveillance. Immunizations in stable situations include BCG (Bacillus Calmette-Guérin for tuberculosis [TB]), polio, DPT (diphtheria, pertussis, tetanus), and measles. In states of emergency, the priority is measles vaccination for children aged 6 months to 14 years. Nutritional support includes treatment of micronutrient deficiency, therapeutic feeding of those who are severely malnourished, and supplemental feeding of those who are moderately malnourished or at increased risk, including children under 5 and women who are pregnant or lactating. Selective feeding programs are instated when prevalence of acute malnutrition is greater than 10 percent among children aged 6 months to 5 years. Control of communicable diseases includes malaria prevention by use of insecticidal bed nets and TB programs. In states of emergency, there is additionally outbreak response planning and increased control of diarrhea, acute respiratory infections, and measles. Reproductive health services include family planning services, sexually transmitted infections (STIs) and human immunodeficiency virus (HIV) services, prenatal and postnatal care, trained healthcare providers attend-
Rehabilitation
ing all deliveries, a referral system and emergency obstetric care, prevention and response to sexual violence, and youth-specific services. The minimum initial services package for reproductive health in states of emergency requires nomination of a coordinator and includes condom distribution, universal precautions against HIV, midwife kits, a referral system for obstetrical emergencies, and prevention and response to sexual violence. In stable situations, the final category of health services includes treatment for chronic illnesses, mental health, and public health surveillance. In emergencies, this category is limited to public health surveillance. The primary causes of death among refugee populations are malnutrition, communicable diseases, and poor reproductive health services. It is of note that under international law, healthcare is a human right. Refugees have the right to the highest standard of physical and mental health and should have access to health services equivalent to that of the host population (Article 23, Refugee Convention of 1951; Article 12, International Covenant on Economic Social and Cultural Rights, 1966). SEE ALSO: AIDS; Disease and Poverty; Immunization/
Vaccination; Infectious Diseases; Malaria; Measles; Public Health; Reproductive Health; Tuberculosis. BIBLIOGRAPHY. United Nations High Commissioner for
Refugees, “Health,” www.unhcr.org (cited April 18, 2007); Lawrence Lader, The Margaret Sanger Story: And the Fight for Birth Control (Greenwood Press, 1975). Noëlle A. Benzekri University of California, Los Angeles
Rehabilitation Rehabilitation concerns the psychophysical restoration of people who have sustained severe injuries and/or have acute, chronic, or progressive disorders and diseases, and promotes the maintenance/extension of their functional abilities. Rehabilitation professionals treat and manage patients’ disabilities and also address the social limitations that may result from their pathophysiology, with
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the aim of enabling them to return to the activities of a normal life. Indeed, rehabilitation professionals take into account physical, psychosocial, cultural, and environmental factors, choosing and utilizing appropriate intervention strategies within a holistic approach. To start a formal rehabilitation program, a medical doctor writes a referral to a rehabilitation professional/ team, describing the type of illness/injury and its date of onset, and sets therapy’s long-term overall goals. Then, the rehabilitation professional/team settles, for each of the patient’s problems, specific short-term goals, helps the patient to achieve them and carefully monitors the patient’s progress. The goals of rehabilitation can differ, depending on factors such as type of impairment and age of the patient: people with chronic impairments, often older people, may need a less intensive but probably longer rehabilitation program than younger people, and require different kinds of therapy than younger people do. For instance, the goal of an older patient who has had a stroke may be to renew his or her ability to accomplish as many self-care activities as possible: eating, controlling bladder and bowel, using the toilet, moving from bed to a chair, dressing, and bathing. The goal of a younger patient who has been involved in a car accident is often to restore his or her full functionality. Treatable Conditions As rehabilitation concerns the holistic concept of global health and is based on the fundamental unity of mind– body system, rehabilitation techniques, which are focused on the body, also have effects on the rehabilitation of the mind. Vice versa, all the injuries/diseases/disabilities/syndromes that affect the body (e.g., musculoskeletal disorders), also have an influence on mind and mood. Therefore, many rehabilitation techniques, whose target is to improve physical health, can also enhance the psychosocial and cognitive status; in turn, many rehabilitation techniques that are aimed to improve the psychosocial and cognitive status can also enhance physical health. Indeed, rehabilitation centers/professionals usually do not use a single rehabilitation technique in an exclusive way, but carry out (with the patient’s agreement) a rehabilitation program that includes a group of techniques, which can be used at the same time or
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By means of various types of therapeutic exercises (which are intended to enhance a range of motion, muscle tone and strength, coordination, balance, and ambulation), physical therapy prevents muscle atrophy and improves functional independence as well as physical performance.
in a sequence; in this way, results, achieved using a certain technique, encourage the acquisition of specific capabilities, which in turn, foster the acquisition of other capabilities, setting up the prerequisites for the use of other techniques. The various rehabilitation techniques can be applied to people affected by blindness, hearing loss, diseases/disorders/injuries of the musculoskeletal apparatus (among them hip, shoulder, and wrist injuries/disorders, limb fractures, arm and leg amputations, muscular dystrophy, etc.), diseases/disorders of the cardiovascular and pulmonary apparatus, neurologic diseases/injuries (such as brain and spinal injuries, which can cause problems in muscular control), neuropsychological, and psychiatric disorders/diseases (such as anxiety, depression, schizophrenia, Alzheimer’s disease, etc.). Specific Rehabilitation Techniques Rehabilitation encompasses several disciplines, each of them using one or more specific techniques; each
of these techniques can be chosen as main or complementary in the treatment, depending on the patient’s particular disease, status and inclinations, and on the services provided by the rehabilitation center. Some of the various rehabilitation techniques are physical therapy (with or without technology-based applications), occupational therapy, recreational therapy, expressive therapies, animal-assisted therapies, aquatic therapy, light therapy, relaxation and distress reduction techniques, and diet/nutrition. Physical therapy includes exercising and manipulating the body and mobilizing contracted muscles/ligaments/tendons, with the aim to relieve pain, decrease joint stiffness, and muscle spasms. By means of various types of therapeutic exercises (which are intended to enhance a range of motion, muscle tone and strength, coordination, balance, and ambulation), physical therapy prevents muscle atrophy and improves functional independence as well as physical performance.
Massage involves rubbing, kneading, brushing, and tapping the patient’s muscles with the aim to help him or her to release tensions and emotions. Some technology-based applications are heat therapy (which utilizes infrared waves, ultrasounds, etc.), cold therapy, and electrical stimulation (this occurs, for instance, in diathermy and transcutaneous electrical nerve stimulation). Occupational therapy aims are to enhance the patient’s ability to perform basic self-care activities (eating, dressing, tying shoes, bathing, etc.) and useful work, through activities that develop sensorimotor, cognitive, and psychological abilities. The level of difficulty depends on the type of impairment: for instance, inserting pegs on a peg board is a simple activity intended to develop fine motor skills, whereas memory games are more difficult activities whose goal is to improve recognition and recall. Recreational therapy utilizes community outings, cooking, crafts, organized games and sports, and so forth, in order to enhance emotional, social, and leisure development, taking into account patients’ interests and lifestyle. Expressive therapies, which include art therapy, dance/movement therapy, music therapy, and theater/ drama therapy, can be especially effective in helping patients to integrate the emotional, physical, and cognitive facets of the self and foster self-awareness and personal growth. Drawing, painting, sculpting, dancing, practicing martial arts such as aikido and tai chi, singing, making instrumental improvisations or performances, playing a role, and so forth, can reconcile inner conflicts, release deeply repressed emotions, enhance fine motor control skills, and improve interpersonal skills. Music therapy is also used in teaching deaf people to modulate volume, rhythm, and melody of their speaking, and in teaching blind people to recognize room spaces and location of sound sources. In animal-assisted therapies, patients with mental illness take care of their own pets or work with animals such as horses, dolphins, and so forth, under the guidance of healthcare professionals; the aims of this kind of therapy are to encourage patients’ communication, increase their empathy, and enhance their socialization. Aquatic therapy is performed using specifically designed water activities (such as swimming, playing water games, etc.), which can also be modified to accommodate individual abilities, in order to help pa-
Reproductive Health (General)
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tients to improve mood, attain a sense of well-being, and ease with their own bodies and restore their quality of function. Because some forms of depression appear to be related to reductions in the exposure to natural light, people who are affected by this kind of disorder can reduce/eliminate their symptoms if they are exposed to a sunshine-like light called light box. Relaxation techniques include meditation, guided visualization, and specific exercises which are aimed at improving posture and breathing in order to equilibrate the body’s energy centers and reduce distress.� People with physical and/or mental illness (such as schizophrenia, autism, drug-induced psychoses, etc.) can manage their symptoms and promote recovery by eliminating milk and wheat products, and/or adding vitamins and other substances, for instance, through herbal treatments. SEE ALSO: Anal/Rectal Diseases; Autism: Bladder Diseas-
es; Breathing Problems; Dieting; Elbow Injuries and Disorders; Exercise/Physical Fitness; Heart Attack; Hip Injuries and Disorders; Leg Injuries and Disorders; Muscular Dystrophy; Myasthenia Gravis; Neurologic Diseases (General); Nutrition; Pathophysiology; Physiatrist; Physical Therapist; Respiratory Diseases (General); Shoulder Injuries and Disorders; Speech and Communication Disorders; Voice Disorders; Wrist/Arm Injuries and Disorders. BIBLIOGRAPHY. Susan O’Sullivan and Thomas J. Schmitz,
Physical Rehabilitation (F. A. Davis, 2006); Carlos W. Pratt, et al., Psychiatric Rehabilitation (Academic Press, 2002); William E. Prentice, Therapeutic Modalities in Rehabilitation (McGraw-Hill, 2005); Mary C. Singleton and Eleanor F. Branch, The Geriatric Patient: Common Problems and Approaches to Rehabilitation Management (Haworth Press, 1989). Alessandra Padula Università degli Studi—L’Aquila
Reproductive Health (General) Reproductive health is of critical importance to men’s and women’s overall health, and contributes to child health. It has physical and psychological components, with social, cultural, moral, legal, ethical,
1478 Reproductive Health (General) economic, and political implications. Gender-power relationships are complex, particularly in developing countries, and affect women’s ability to negotiate reproductive matters such as safer sex, contraceptive use, and family size. Reproductive illnesses strike at a time in men’s and women’s lives when they are most productive, with devastating effects on the family and a country’s economy. These factors make reproductive health an important and controversial topic on many levels. Reproductive health is defined by the World Health Organization (WHO) as: A state of complete physical, mental and social well-being and not merely the absence of disease or infirmity, in all matters relating to the reproductive system and to its functions and processes. Reproductive health therefore implies that people are able to have a satisfying and safe sex life and that they have the capability to reproduce and the freedom to decide if, when and how often to do so. Implicit in this last condition are the right of men and women to be informed and to have access to safe, effective, affordable and acceptable methods of family planning of their choice, as well as other methods of their choice for regulation of fertility which are not against the law, and the right of access to appropriate health-care services that will enable women to safely go through pregnancy and childbirth and provide couples with the best chance of having a healthy infant. Whereas reproductive healthcare is defined as: The constellation of methods, techniques and services that contribute to reproductive health and well-being by preventing and solving reproductive health problems. It also includes sexual health, the purpose of which is the enhancement of life and personal relations, and not merely counseling and care related to reproduction and sexually transmitted diseases. Global Commitment to Reproductive Health In September 1994, world leaders from 179 countries, nongovernmental organizations, and representatives from United Nations (UN) agencies came together in Cairo, Egypt, at the third Interna-
tional Conference on Population and Development (ICPD) to agree on a 20-year Programme of Action (PoA). This conference was unique in many ways. Unlike previous population conferences, the ICPD focused on meeting the individual needs and rights of men and women rather than on reducing population growth. The PoA set 20-year goals in the following areas: • universal education • reduction of infant and child mortality • reduction of maternal mortality • access to reproductive and sexual health services including family planning The conference represented a major shift in thinking from a focus on family planning and treatment of sexually transmitted infections (STIs) to reproductive health, which includes gender relationships, diseases and conditions related to reproduction, and sexual health. This definition of reproductive health and the view of sexuality now included not only the family, but also individuals, both married and unmarried. In 2000, world leaders met again at the 55th General Assembly of the UN and adopted the Millennium Declaration and the eight Millennium Development Goals (MDGs), which included commitments to improve, by 2015, global situations related to poverty, universal education, gender equity, child health, maternal health, HIV/AIDS, the environment, and global partnerships. Sexual and reproductive health were not a specific focus of the 2000 Millennium Declaration or the MDGs. This was considered a critical omission because sexual and reproductive health are essential to achieving the MDGs, particularly related to maternal and child health. However, in May 2004, the WHO endorsed the first global strategy to accelerate progress toward attainment of international development goals and targets related to reproductive and sexual health. Sexual and Reproductive Health Sexual and reproductive health has five components: • pregnancy, childbirth and newborns • family planning services, including infertility services • unsafe abortion • STIs, including HIV, and other reproductivetract infections • healthy sexuality
In developed countries, the majority of women receive prenatal care, or care provided while a woman is pregnant, and most give birth under the care of a skilled healthcare provider with access to emergency care if needed. However, this is not the case in many developing countries, particularly in Africa and Asia. Every year, over 500,000 women die from maternal mortality—complications related to pregnancy and childbearing. Ninety-nine percent of these women come from developing countries, and only 1 percent are from developed countries. Another 15 million women worldwide suffer long-term disabilities, injuries, infections, or infertility as a result of pregnancy and childbirth. These problems include severe anemia, ruptured uterus, kidney damage, chronic high blood pressure, chronic pelvic pain, pelvic inflammatory disease or organ damage from infections, and obstetric fistula. Obstetric fistula is a hole in the vagina or rectum caused by prolonged labor. When labor goes on, sometimes for days without treatment, often the baby dies and a fistula develops. The fistula leaves women leaking urine or feces, or both. This condition is highly stigmatized and usually results in social isolation and depression. When a woman dies during childbirth in the developing world, the child she is carrying almost always dies. When a woman dies in the postpartum period, or within six weeks after the birth of a child, the child very often dies. In 1987, the Safe Motherhood Initiative, a worldwide effort to reduce the number deaths and illnesses related to pregnancy and childbirth, was launched at a conference in Nairobi, Kenya, to draw attention to the seriousness of the problem. Since then, Safe Motherhood has become synonymous with efforts to reduce maternal mortality around the world. Maternal mortality is largely preventable, and the fifth MDG aims to reduce maternal mortality by three-fourths by 2015. Causes of maternal mortality are both direct and indirect. The major direct causes worldwide include hemorrhage, or severe bleeding (24 percent), infection (15 percent), eclampsia or high blood pressure (12 percent), unsafe abortion (13 percent), obstructed labor (8 percent), and other direct causes (8 percent). Indirect causes (20 percent) include those that result from previously existing disease, or disease that develops during pregnancy, labor or after the baby is
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born, including anemia, malnutrition, malaria, pneumonia, and tetanus. Obstacles to safe motherhood are associated with the “three delays”: a delay in the decision to seek care, delays in reaching care, and delays in receiving appropriate care. What, then, should be done to reduce maternal mortality? The latest evidence seems to suggest that a skilled attendant (a midwife, nurse, or doctor trained to manage a normal birth) at childbirth with proper training and a range of skills to be able to assess risk factors and recognize complications, who can perform essential basic interventions and refer to a higher level of emergency obstetric care if complications arise, is the most effective intervention. Prenatal care is important to detect problems early and prepare for birth, and training traditional birth attendants is also a critical part of the strategy. Women must also have access to the full range of modern contraceptive methods to be able to avoid unintended pregnancies. Newborn Care Newborns who die during the first 28 days of life account for two-thirds of deaths in infancy. Ninetyeight percent of all neonatal deaths occur in developing countries and deaths are due primarily to infection, asphyxia (suffocation), and consequences of low birth weight (LBW) and prematurity. Efforts to improve the health and survival of women and their newborn babies during pregnancy, childbirth, and the postnatal period include providing effective prenatal care, immunizing mothers against tetanus, prevention and management of STIs and reproductive-tract infections, and promoting early and successful initiation of breastfeeding, among others. Family Planning Services, Including Infertility Services Family planning (also called birth control or contraception) is used to prevent unintended pregnancies and unsafe abortions, control the timing of pregnancy and spacing of children, and prevent transmission of STIs. Use of family planning can reduce maternal mortality, improve child survival, and can potentially raise women’s status by increasing opportunities for education and employment. There are many different methods of family planning. Modern methods include barrier methods (diaphragm, condom, female condom, contracep-
1480 Reproductive Health (General) tive sponge, cervical sponge); spermicides; hormonal methods (the pill, patch, contraceptive vaginal ring, injectable contraceptives, implants); intrauterine methods; emergency contraception; and sterilization, both male and female. Other methods are behavioral or natural methods. These include fertility awareness methods, which involve tracking signs of the body’s fertility and abstaining from sex during those periods that are determined to be fertile; coitus interruptus (interrupted sex) or the withdrawal method, the practice of “pulling out” of the vagina before the man ejaculates; and the Lactational Amenorrhea Method (LAM), which describes the time that a woman remains infertile while she is intensively breastfeeding. Infertility is a problem that affects couples globally; on average 8 to 12 percent of couples are unable to conceive. In developing countries, the woman often shoulders the blame for the couple’s inability to conceive, and she can be divorced in favor of another woman who can bring a child into the marriage. Factors causing high rates of infertility in parts of the developing world include STIs, postpartum and postabortion infections, female genital mutilation, diet and environmental factors, and patterns of sexual behavior, among others. Male infertility contributes to more than half of all cases of infertility, a little known fact. While some developing countries can offer more expensive advanced technologies such as in vitro fertilization, low-technology interventions such as artificial insemination, antibiotic treatment of STIs, and counseling on timing of intercourse to improve the changes of conception are cost-effective methods in low-resource settings. Family Planning Programs The birth control movement began in the United States in 1916 when Margaret Sanger opened the first birth control clinic in Brooklyn, New York. Sanger helped organize the National Birth Control League, which became the American Birth Control League in 1921 and the Planned Parenthood Federation of America in 1942. High rates of population growth led to the initiation of the first birth control programs in India and Pakistan in the 1950s. The UN began offering funding for international population assistance in the 1960s, and by the 1970s, private foundations, international agencies, the U.S. government, and other developed nations were pro-
viding funding to support what was no longer called “birth control” but rather “family planning.” It was argued that high rates of population growth were inhibiting social and economic development. Opponents of family planning programs believed larger populations could contribute to production and improvement of a country’s standard of living. Between 1960 and 2000, the proportion of married women using contraception in developing countries increased from less than 10 percent to around 60 percent. In the 1960s, the average number of children per woman in the developing world was six; today, it is three. It should be recognized, however, that there is wide variation across regions and there are still countries where the average number of children per woman is over six (most in Africa). In 1979, China introduced a policy limiting parents to one child. The one-child policy has been criticized as coercive, and the U.S. government withdrew funding from the UN agency responsible for population activities, the United Nations Population Fund (UNFPA) in 2002 based on claims it was supporting coercive abortion in China. Some would argue the global fertility decline has been due to the success of national family planning programs; however, others would say it reflects the desired number of children, influenced by socioeconomic circumstances. One hundred twenty million couples have “unmet need” for family planning, which means they would like to prevent a pregnancy but are not using a modern method of contraception. Many of these women have unintended pregnancies, and some resort to unsafe abortion. There are a number of reasons why women have unmet needs for family planning, including lack of accurate information, poor quality health services, lack of access to the full range of contraceptive choices, as well as legal, cultural, and economic barriers. Unsafe Abortion An abortion is the removal of the products of conception—the fetus, the fetal membranes, and the placenta—from a woman’s uterus. If it occurs spontaneously and naturally, it is called a miscarriage. If termination of the pregnancy is induced artificially and the products of conception are removed from the uterus, it is called an abortion. While abortion has been in existence for hundreds of years throughout the world,
its practice has remained contentious even today for both legal and moral reasons. Unsafe abortion is a major reproductive health problem in the world today. It is estimated that 45 million unintended pregnancies are terminated each year; of those, 19 million are considered to be unsafe. Ninety-seven percent of unsafe abortions are in developing countries. It is estimated that 68,000 women die as a result of unsafe abortions and millions more have complications. Availability of modern contraception can reduce but not eliminate the need for abortion. The WHO defines unsafe abortion as a procedure for terminating an unintended pregnancy either by individuals without the necessary skills or in an environment that does not conform to minimum medical standards, or both. Postabortion treatment, counseling, and care are particularly important following an abortion to break the cycle of unwanted pregnancies and improve women’s health. Abortion has been subject to considerable debate in the international arena, particularly with regard to international funding. While it was legalized in the United States following the Roe v. Wade Supreme Court decision in 1973, at the second UN International Conference on Population in Mexico City in 1984, the Reagan administration announced what became known as the Mexico City Policy, or “the global gag rule”: no foreign nongovernmental organization that performs abortions in cases other than a threat to the woman’s life, rape, or incest; provides counseling and referral for abortion; or lobbies to make abortion legal or more available in their country, could receive U.S. family planning assistance. The ban was lifted by President Clinton in 1993 and reinstated by President Bush in 2001. This policy has seriously hindered the ability of developing countries to provide family planning and reproductive health services to their populations, because U.S. family planning assistance makes up a large part of their budgets. STIs, Including HIV, and Other Reproductive-Tract Infections The WHO estimates there are over 340 million new cases of curable STIs every year, and millions of incurable viral cases, including an estimated 5 million HIV cases annually. STIs and other reproductive tract infections are a significant cause of death and disabil-
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ity, particularly in the developing world. Human papillomavirus (HPV) causes almost all cervical cancers; syphilis can be fatal and causes babies to be stillborn; and chlamydia and gonorrhea can cause infertility. Candida and bacterial vaginosis, while not sexually transmitted, are the most common reproductivetract infections, and are costly both financially and in terms of the disability they cause. While STIs are an important global health issue, they have fallen in priority on the international health agenda in light of the human immunodeficiency virus (HIV)/AIDS pandemic. MDG six aims to halt and begin to reverse the spread of HIV/AIDS, but the MDGs neglect to mention other STIs. What is considered important is the biological link between STIs and HIV: STIs that cause genital ulcers or open sores like genital herpes and syphilis increase the risk of HIV infection, and treatment of STIs reduces the amount of HIV virus in genital secretions and blood. STI prevention and control efforts have had limited success, particularly in developing countries. Latex condoms, used correctly and consistently, are the most effective way to prevent acquisition of new STIs and to prevent transmission of infection. Female condoms are not used as often as male condoms because they are more expensive and more inconvenient to use. The ABC approach to reducing STIs is being promoted throughout the world: Abstinence from, or delay of sexual activity, particularly for youth; Be faithful for couples in committed relationships; use Condoms if you engage in risky behavior. New microbicides are being studied for effectiveness in preventing STIs, including HIV. A new vaccine is now available to prevent HPV, although it is not likely to be affordable in developing countries. There are a number of different approaches to the diagnosis and treatment of STIs. People who seek treatment for STIs face many difficulties, particularly in developing countries that do not have access to drugs, medical equipment, supplies, and adequately trained staff. While there is no standard model for STI service delivery, and it is debatable as to whether STI services should be integrated into family planning and other healthcare services or whether they should be offered as “stand-alone” services, targeted interventions—those that target people who are at high risk of contracting STIs, such as sex workers, men who have
1482 Reproductive Health (General) sex with men, and adolescents—are becoming more common due to their success. HIV/AIDS HIV/AIDS was first recognized in 1981 and since then, it has killed more than 25 million people around the world. Today, it is estimated that there are almost 40 million people infected with the virus, the majority of whom (almost two-thirds) live in sub-Saharan Africa. By the end of 2005, there were 11 million AIDS orphans in sub-Saharan Africa alone—children who had lost one or both parents to AIDS. In parts of Africa, adult infection rates are higher than 30 percent. The virus is transmitted in the blood, semen, vaginal fluids, and breastmilk usually through anal, vaginal, or oral sex, blood transfusions, or contaminated hypodermic needles, or during pregnancy, childbirth, or breastfeeding. As with other STIs, the male latex condom is the most effective way of reducing transmission of HIV. The female condom is also effective where available. Recent studies have shown that male circumcision reduces the risk of men becoming infected with HIV by at least 50 percent. The dominant mode of HIV transmission in Africa and Asia is heterosexual. Homosexual transmission is more common in Europe and the United States. Seven hundred thousand children become infected with HIV every year through mother-to-child transmission as a result of breastfeeding or childbirth.If an HIV-positive woman becomes pregnant, there is a 35-percent chance that she will transmit the virus to her child if no preventative action is taken. Approximately 15 to 20 percent of children are infected during pregnancy, 50 percent during delivery, and 33 percent through breastfeeding. Women are at greater risk of being infected than men for a number of reasons including ease of transmission, inability to negotiate safer sex, and lack of female-controlled HIV prevention methods. Strategies to address the HIV/AIDS pandemic include prevention and health promotion, and treatment strategies. Prevention and health promotion strategies include the following: (1) voluntary counseling and testing, including testing and counseling for Prevention of Mother-to-Child Transmission of HIV (PMTCT) in prenatal and labor and delivery settings; (2) interventions for most-at-risk popu-
lations, including commercial sex workers, men who have sex with men, intravenous drug users, and others; (3) wide-ranging public information campaigns that educate about HIV/AIDS, promote safe and responsible sexual behavior, delay sexual activity, encourage abstinence, limit the number of sexual partners, and encourage condom use; (4) promotion of harm reduction among intravenous drug users; (5) increasing availability of condoms; (6) need for laws and policies to counteract stigma and discrimination against HIV/AIDS. Treatment strategies include the following: (1) diagnosis and treatment of STIs; (2) improving services for diagnosis and treatment of HIV/AIDS and opportunistic infections such as tuberculosis; (3) effective use of antiretrovirals. In his State of the Union Address in 2003, President George W. Bush announced the President’s Emergency Plan for AIDS Relief, often known as PEPFAR, a U.S. five-year $15-billion global initiative to combat the HIV/AIDS epidemic. Goals include supporting treatment for 2 million HIV-infected people, preventing 7 million new HIV infections, and supporting care for 10 million people infected and affected by HIV/AIDS, including orphans and vulnerable populations in 15 focus countries, 14 in Africa and the Caribbean, and Vietnam. Healthy Sexuality Sexual health has many aspects such as an individual’s ability to enjoy and control sexual and reproductive behavior; freedom from shame, fear, and guilt; and freedom from diseases that interfere with sexual and reproductive function. It includes freedom from discrimination based on gender and sexual orientation, freedom from sexual violence, and freedom from bodily mutilation. In the context of global health, an issue of considerable importance is female genital mutilation (FGM), also called female circumcision or female genital cutting. This is a procedure that is conducted in various parts of the world, usually for cultural or religious reasons, in which part or all of the external female genitalia (clitoris and inner and outer labia) are removed. The age at which it is performed varies: It can be performed not long after birth, on young adolescent girls, and occasionally on mature women. It is usually performed by an untrained, traditional practitioner with crude instruments and without anesthetic. The
consequences can be both physical and psychological and include pain, shock, hemorrhage, difficulty urinating, sexual dysfunction, and difficulties with childbirth. The WHO estimates that 2 million girls are at risk of undergoing FGM every year. Sexual violence against women is a global problem. In a multicountry study of over 24,000 women, the WHO reported that between 6 and 59 percent of women who had ever been in a relationship with a man had suffered sexual violence by her male partner. SEE ALSO: Abortion; Birth Control/Contraception; Preg-
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Organization, Department of Reproductive Health and Research, “Reproductive Health Strategy to Accelerate Progress towards the Attainment of International Development Goals and Targets,” www.who.int/repro ductive-health/publications/strategy.pdf (cited March 2007); World Health Organization, “Female Genital Mutilation,” www.who.int/mediacentre/factsheets/fs241/en (cited March 2007). Connie Currier, Dr.P.H., M.P.H. Michigan State University
nancy; Sexually Transmitted Diseases.
BIBLIOGRAPHY. C.H. Claudia García-Moreno, et al.,
“WHO, Multi-Country Study on Women’s Health and Domestic Violence against Women,” www.who.int/gender/ violence/who_multicountry_study/en/index.html (cited March 2007); Duff Gillespie, “Whatever Happened to Family Planning, and for That Matter, Reproductive Health?” International Family Planning Perspectives (v.30/1, 2004); Marcia Inhorn, “Global Infertility and the Globalization of New Reproductive Technologies: Illustrations from Egypt,” Social Science & Medicine (v.56/9, 2003); Lawrence Lader, The Margaret Sanger Story: And the Fight for Birth Control (Greenwood Press, 1975); David March, et al., “Advancing Newborn Health and Survival in Developing Countries: A Conceptual Framework,” Journal of Perinatology (v.22/97, 2002); PATH, “Reproductive Health Outlook,” www.rho. org (cited March 2007); Safe Motherhood Inter-Agency Group, “Safe Motherhood,” www.safemotherhood.org (cited March 2007); United Nations, Report of the International Conference on Population and Development (United Nations, 1994); United Nations, “UN Millennium Development Goals,” www.un.org/millenniumgoals (cited March 2007); United Nations Children’s Fund, “HIV/AIDS and Children,” www.unicef.org/aids/index_ preventionMTCT.html (cited March 2007); USA.gov, “The United States President’s Emergency Plan for AIDS Relief,” www.pepfar.gov/ (cited March 2007); USAID, “Maternal & Child Health,” www.usaid.gov/our_work/global_ health/mch/mh/techareas/maternal_mortality.html (cited March 2007); World Health Organization, Department of HIV/AIDS, “Global Health Sector Strategy for HIV/AIDS, 2003–2007, Providing a Framework for Partnership and Action,” www.who.int/hiv/pub/advocacy/ hiv2002_25en.pdf (cited March 2007); World Health
Respiratory Diseases Respiratory illnesses are common clinical manifestations encompassing numerous conditions ranging from the benign common cold to chronically debilitating conditions inclusive of lung cancers and Chronic Obstructive Pulmonary Disease (COPD). With a prevalence rate affecting over 78 percent of the U.S. population, respiratory conditions warrant significant attention in today’s health care system. The World Health Organization attributed over 226,000 deaths in the Americas and almost 4 million deaths worldwide to respiratory conditions. The high prevalence rate not only implicates a potential for an economic burden due to a decrease in a labor work force but also drives up health care costs for admissions as a result of such conditions. Although many respiratory diseases may entail predisposing factors inclusive of age, genetics, locations, and behavior patterns, certain pulmonary conditions have the potential to inflict disease in virtually any age group. Of the numerous respiratory conditions that exist, the most commonly occurring conditions include: Common Cold, Influenza, Pneumonia, Chronic Obstructive Pulmonary Disease (COPD), Cystic Fibrosis, Tuberculosis and Lung Cancer. Common Cold Of all respiratory conditions, the most common includes the common cold with an incidence rate of 22 percent percent in the United States. It is often more prevalent in the winter months however, may present at any time of the year. In most cases, the most common causative agent is a rhinovirus although other
1484 Respiratory Diseases etiological agents include: coronavirus, echovirus, paramyxovirus and coxsackievirus. Symptoms entail cough, nasal congestion, headache, fatigue, and generalized malaise. The condition is self-limiting and as a result, treatment is often supportive. Symptoms routinely resolve within 3 to 5 days with the exception of patients with compromised immunity, which may develop into more serious and progressive illnesses such as pneumonia. Usually this progression occurs as a result of bacterial co infection either from within the body or from an external source. As the mode of transmission is highly facilitated through respiratory droplets, preventative measures should include frequent hand washing and avoiding affected disease carriers. Influenza Another common illness in the winter months includes influenza, also known as the flu. In year 2000, the incidence of the flu was approximately one in three people and affecting 97.9 million individuals in the United States. The most common causes of influenza are influenza A and influenza B. Symptoms of the infection are somewhat more severe than those for the common cold. Flu-like symptoms include cough, runny nose, fevers, chills, headaches, mus-
Respiratory illnesses range from the common cold to lung cancer to Chronic Obstructive Pulmonary Disease (COPD).
cle weakness and the general feeling of being drained of energy. The infectious agent mainly attacks the upper respiratory tract. In neonates, the elderly, and immunocompromised patients, the agent may also cause pneumonia and even death. However, a full recovery is almost always expected among infected healthy individuals. Treatments for the flu many consist of fluid replacement and rest. However, in extreme cases, anti-viral medications such as amantadine may be indicated. With the increased availability of the influenza vaccine, the incidence of cases is decreasing. Among the elderly, vaccination is thought to reduce influenza-related morbidity by 60 percent and influenza-related mortality by 70 to 80 percent. Among healthy adults the vaccine is very effective in terms of reducing influenza morbidity, and vaccination has been shown to have substantial health-related and economic benefits in this age group. Recently, a new strain of the Influenza A, or avian flu virus, present in birds has become a public concern. Due to its high infectivity and the increased amounts of birds infected, many precautions are being taken to prevent a full-blown outbreak of the illness. Its transmission pattern is facilitated through the secretion of infected organisms and further perpetuated through respiratory droplets from human to human contact. The symptoms of avian influenza vary greatly. They can be as mild as a sore throat, to normal flu-like symptoms, to severe conditions such as pneumonia, and other severe and life-threatening complications. The symptoms of avian influenza may depend on which virus caused the infection. There is currently no treatment available, but research has been ongoing in hopes of developing possible vaccines since 2005. Pneumonia Pneumonia is a leading cause of death in the elderly and immunocompromised individuals. Pneumonia is an infection of the lungs that can be due to bacterial or viral organisms, foreign bodies or even chemicals. The manifestation of such an infection is fluid build up in the alveoli, the small air sacs of the lungs, and causing symptoms. Typically, patients present with cough, chest congestion, fever, chills, chest pain and difficulty breathing. However, some patients may have atypical pneumonia or walking pneumonia, that is patients don’t usually have any symptoms and the pneumonia is often an incidental
finding. A vaccine is available which is usually taken every five years and is composed of 23 strains of the common pneumonia organisms. Diagnosis is often made based on clinical signs and symptoms however, sputum culture and chest radiographs are routinely ordered to confirm a diagnosis of pneumonia. Depending on the cause of the pneumonia, the sputum may be different colors. Often times yellowish/brown sputum indicated bacterial infection usually by Streptococcus pneumoniae, a greenish sputum denotes a pseudomonal infection and a whitish/ clear could be present in viral illness. On X-ray, the pneumonia gives a “washed-out” appearance in one area of the lung and obliterates the diaphragmatic angles due to fluid buildup. Treatment of pneumonia is specific to the etiological agent responsible for the infection and often includes antibiotics, symptom management, and prevention of future complications. Chronic Obstructive Pulmonary Disorder Chronic Obstructive Pulmonary Disease (COPD) is a generalized term that covers many different obstructive pulmonary conditions and affects over 13.5 million Americans. These include chronic bronchitis, asthma, emphysema, and bronchiectasis. They all, however, work through an obstructive process by restricting expelled airflow out of the lungs, resulting in excessive trapped air within the lungs. Typically COPD patients clinically present with respiratory difficulty, expiratory wheezing, abnormal pulmonary function studies resulting in an increased FEV1/FVC and high residual lung volumes, and a flattened diaphragmatic affect on chest radiography. Chronic bronchitis is a form of COPD affecting over 12 million Americans. The condition is clinically characterized by productive cough for more than three consecutive months for at least two years. It is most often seen in smokers, but may also be a result of exposure to various environmental toxins such as solvents or coal dusts. The pathophysiology is most adequately demonstrated by a hypertrophy, or increased size, of the mucus-secreting goblet cells in the bronchioles. Usually patients present with a productive morning cough and experience remarkable respiratory distress. Patients who are smokers are encouraged to quit smok-
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ing and mucolytic agents may be prescribed to dissolve excess mucous. Asthma is another form of COPD and is characterized as bronchial hyper reactivity to certain allergens or triggers that is reversible. It is characterized by bronchoconstriction and wheezing that is often audible. It is one of the most common childhood diseases, however, many times it resolves by adulthood. Approximately 6.4 percent of the people in USA have asthma. Treatment is symptom-based and for patients with a mild form of the disease, a bronchodilator such as albuterol is often prescribed. However, in patients with more persistent symptoms, daily treatment with various medications is tried. These include beta 2 agonists such as salmeterol, mast cell (inflammatory cells responsible for the release of histamine) desensitizing agents such cromolyn sodium, anti-inflammatory agents such as corticosteroids, or antileukotirenes such as zileuton and zafirlukast. These drugs are used to dilate the airways, prevent bronchospasm and decrease the inflammatory response of the body. In patients refractory to those treatments, hospital management with IV steroids, ipratropium and nebulizaer treatments may be indicated. Emphysema is a COPD condition that is defined by the loss of lung elasticity as a result of the destruction of the alveolar walls. It results in enlargement of the air spaces and collapse of the small airways resulting in the entrapment of air. There are four main types of emphysema. Only the panacinar type is of restrictive pattern, the rest maintain an obstructive patterns. Panacinar emphysemia is a genetic disorder resulting in a deficiency of alpha-1-antitrypsin. Alpha-1-antitypsin is used to produce a molecule known as surfactant, which lines the alveoli and allows the recoil function of the lungs. The other types of emphysema are distal acinar, which is a result of aging; centoacinar, a result of smoking; and bullous, which is due to infection by Staphylococcus aureus or Pseudomonas aerginosa. The prevalence of emphysema is approximately 2 million Americans. Emphysema is an irreversible degenerative process for which no treatment is currently available. However, patients are encouraged to stop smoking and given symptomatic treatment based on acute exacerbations, similar to the treatments for the other COPD conditions.
1486 Respiratory Diseases Bronchiectasis is a chronic infection of the bronchi, which is most often seen in patients with cystic fibrosis. It is also seen in patients with bronchial obstruction, such as aspiration patients, immunodeficient patients, and patients with poor ciliary motility. Diagnosis may be made on clinical presentation, patient history, and laboratory studies inclusive of white blood cell count and chest radiography. Cystic Fibrosis Cystic fibrosis is a systemic manifesting genetic illness affecting virtually every organ. Patients with the disease produce very thick mucous secretions that block the airways resulting in infections and difficulty breathing. Patients generally have a poor prognosis with an average life expectancy of 20 to 30 years. Currently there is no curative treatment available for the disease. However, various daily percussion techniques are used to help clear the secretions from the lungs. Humidifiers and bronchodilators are used to improve airflow and often times prophylactic antibiotics are used to prevent infections. The most common infections seen in these patients are due to Pseudomonas aergenosa. Cystic fibrosis is most common in people of European descent, with a special predisposition to the Ashkenazi Jew population. Approximately 2,500 children are born every year with the disease, with 1 in every 3,300 Caucasian children having the disease. Tuberculosis Tuberculosis (TB) is a chronic infection caused by the bacteria Mycobacterium tuberculosis and has been noted to cause more deaths than any other infectious disease in the world. Although, the disease is much more common and deadly in developing countries when compared to cases in the developed world. Approximately one-third of the world’s population is infected with the bacteria. However, it affects less than 200,000 Americans. In 2004, the prevalance of active TB disease was 14.6 million people with an incidence of 8.9 million people and mortality of 1.7 million people, mostly in developing countries. The bacteria invades the hilar nodes of the lungs and also forms a Ghon focus, which is usually located in the lower lobes. The combination of the two is called the ghon complex. The body heals and develops immunity and hypersensitivity, which then results in a positive TB test, a commonly used diagnostic criteria for TB.
The tuberculin test, also known as the Mantoux test, is performed by injecting PPD tuberculin on the forearm directly under the skin. The result is read 48 hours later by measuring the amount of induration present. If it is a healthy patient with no known risk factors, the test is considered positive if it measure >15mm across. In patients who are recent arrivals from countries where TB is prevalent, IV drug users, children <4 years old, residents and employees of health care facilities and lab personnel, and people with chronic medical condition, a flare of 10 mm or more is positive. Finally, if it is a patient who is immunocomprosmised, has a previous history of TB exposure, or with a positive chest x-ray consistent with previous TB, an induration of 5 mm or more is positive. Secondary TB is seen in partially hypersensitized hosts. On chest x-ray, a fibrocaseous cavitary lesion is noted at the apices of the lungs. It may be due to reactivation of previously infected hosts, in which case the previous ghon complex may be seen on x-ray as well. TB may also spread from the lungs and manifest itself extrapulmonarily in the spine, brain and spinal cord, renal or gastrointestinal systems. All TB patents must go on medical treatment with multi-drug therapy due to increased cases of antibiotic resistance. Such treatment includes combination therapy of Rifampin, Isoniazid, Pyrazinamide, Ethambutol, and Streptomycin. Furthermore, due to TB’s extremely infective transmission pattern, all close contacts must be treated prophylactically. Treatment guidelines for exposed patients include 6 months of isoniazid and vitamin B6 therapy for effective prophylaxis. Lung Cancer Lung cancer is one of the leading causes of death worldwide, accounting for up to 3 million deaths annually. The affliction has a poor prognosis with less than five year life expectency subsequent to a new diagnosis. Although mostly affecting both genders equally, more women die of lung cancer than any other cancer including breast, ovarian, and uterine cancers combined. Risk factors with the greatest accountability leading to lung cancer include long term exposure to inhaled carcinogens such as tobacco smoke, radon gas, and asbestos. Genetic predisposition, viral agents, and the presence of primary tumor elsewhere in the body are also other commonly known risk factors.
Retinal Disorders
Symptomatic findings leading to a diagnosis of lung cancer may include respiratory distress, coughing up blood, chest pain, abnormal weight loss, fatigue, loss of appetite, difficulty swallowing, fevers, and hoarse voice. Clinical diagnosis of lung cancer is routinely made subsequent to a thorough medical history with particular focus to social habits, family history of cancers, and a past medical history. Patients are routinelly chest radiographed and a lung biopsy is taken to ensure a malignant pathology before treatment options are evaluted. Patients may also undergo pulmonary function studies to evalute respiratory status to ensure that they are eligible for elective surgery. With the several types of lung cancer that exist, treatment for the condition depends on the specific cell type, extent of spread, and the patient’s health status. Typical treatment options for the condition include chemotherapy, radiation therapy, and surgery. Although, they have been known to be used in combination, treatment options are always customized for individual cases. SEE ALSO: Asthma; Bronchitis; Chronic Obstructive Pul-
monary Diseases; Emphysema; Pulmonary Fibrosis.
BIBLIOGRAPHY. AJ Alberg and JM Samet, “Epidemiology
of lung cancer,” Chest (January 2003); CDC, “Key Facts About Avian Influenza and Avian Influenza Virus,” www. cdc.gov/flu/avian/gen-info/facts.htm (cited June 2007); NA Hanania, et al., “Treatments for COPD,” Respiratory Medicine (v. 99 Suppl B, 2005); WHO, “Influenza,” www.who.int/mediacentre/factsheets/fs211/en/ (cited June 2007); Wikepedia, “Lung Cancer,” www.wikepedia. com (cited June 2007); Wikepedia, “Pneumonia,” http:// en.wikipedia.org/wiki/Pneumonia (cited June 2007). Utkarsh Acharya, BS Ohio University College of Osteopathic Medicine Amee Mehta, MD Independent Scholar
Retinal Disorders Retinal disease is a major cause of blindness and morbidity worldwide, accounting for at least 15 percent of blindness. Precipitating factors include vascular dis-
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ease, infection, malnutrition, and genetic mutations. Many retinal diseases can be treated without residual visual defects, yet treatment delay, poor access to eye care, lack of prevention education, and poverty lead to preventable vision loss. Age-related macular degeneration (AMD) accounts for 8.7 percent of blindness worldwide, making it the leading cause of vision loss from posterior segment disease. AMD, manifesting most often in the sixth decade and progressing with age, results from the photoreceptor dysfunction in the macula. The dry subtype is more common, caused by accumulation of yellow deposits known as drusen that interfere with processing fine visual acuity. The pathophysiology involves vascular disease and cellular defects of the retinal pigment epithelium. Surgical therapies can stabilize disease progression, but no cure currently exists. As the global population ages, morbidity due to AMD will warrant increased attention. Diabetic retinopathy, a chronic complication of diabetes mellitus (DM), is the second leading cause of blindness of retinal origin, contributing to 4.8 percent of cases globally. In nonproliferative retinopathy, the retinal microvasculature develops aneurysms and obstruction to blood flow. As the retina becomes starved of nutrients, neovascularization occurs, which characterizes proliferative retinopathy. These naive vessels tend to leak and produce macular edema, which can produce irreversible vision loss, even in the absence of symptoms. Yearly screening is recommended to detect early disease. In contrast to the above chronic diseases, central retinal artery occlusion (CRAO), a rare vascular cause of retinal blindness, often presents as a medical emergency. Risk factors include hypertension, DM, and carotid artery disease. The most common etiology is carotid thrombus embolization. Complete vision loss in the respective eye is inevitable if a patient fails to seek medical attention within one hour. Retinal detachment is another medical emergency that occurs secondary to trauma, infection, anatomical defects, and intraocular fibrosis. Central retinal vein occlusion (CRVO) is less emergent but can become complicated by neovascular glaucoma, ischemia, and blindness. The most significant cause of preventable blindness due to retinal infection is Onchocerca volvulus, a parasite transmitted by black flies indigenous to sub-Saharan Africa, Yemen, and Latin America.
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Treatment delay, poor access to eye care, lack of prevention education, and poverty can lead to preventable vision loss.
Commonly known as river blindness, onchocerciasis afflicts populations that inhabit regions near streams or rivers. The microfilariae nonselectively destroy eye structures, including the retina. Ivermectin effectively eradicates onchocerciasis, thereby averting devastating complications. Patients with advanced human immunodeficiency virus (HIV), especially those with a CD4 count of 100 cells/mL, are prone to developing CMV retinitis. Occurring in 25 percent of AIDS cases, CMV retinitis leads to visual acuity defects, loss of peripheral vision, and ultimately blindness. Maintaining adequate CD4 counts can prevent CMV retinitis, and antiviral agents such as Valganciclovir and Foscarnet are proven effective therapies. Vitamin A deficiency is the most common dietary source of retinal disease. The prevalence is most alarming in sub-Saharan Africa, India, and South America. By impairing rhodopsin production, low vitamin A yields night blindness clinically. A number of landmark studies have further demonstrated that vitamin A supplementation remarkably reduced child mortality. Hence, the World Health Organization, United Nations Children’s Fund, and the Vision 2020 initiative have embarked on a global campaign to distribute vitamin A supplements. Retinoblastoma is a rare eye cancer that occurs in about 1 in every 15,000 live births. The autosomal dominant mutation of the RB1 gene on chromosome 13q14 manifests clinically as leukocoria, or a white pupil apparent on inspection. It may present at
birth or later in life. The best available treatment is enucleation of the eye, which cures the cancer. Retinitis pigmentosa encompasses a family of dozens of rare genetic disorders that ultimately cause pan-dysfunction of retinal photoreceptors. The damage commonly begins peripherally with rod cells, manifesting as worsening night blindness and loss of peripheral vision, and progress inward to affect the cone cells, producing macular symptoms. . Tay-Sachs is a highly fatal neurological disease transmitted by autosomal recessive inheritance that causes blindness and can appear on fundoscopy as a “cherry-red spot.” The retinal disease is caused by decreased production of hexosaminidase A, which leads to pathologic excess of GM2 gangliosides in retinal ganglion cells. Tay-Sachs predominates among the Ashkenazi Jewish population in whom the carrier rate approaches 1 in 40 Jews. The cherry-red spot also appears in Neimann-Pick disease, a lipidosis characterized by sphingomyelinase deficiency. As with TaySachs, Neimann-Pick disproportionately afflicts Ashkenazi Jews, and is also prevalent in certain North African and French-Canadian populations. Retinopathy of prematurity (ROP) causes blindness in thousands of children annually worldwide, and several times more suffer from myopia, amblyopia, strabismus, glaucoma, and retinal detachment. The pathogenesis is attributed to the arrested development of retinal vascularization in premature babies, especially those born prior to 32 weeks of gestation. Zone 1 disease interrupts vasculogenesis and portends the most serious complications, whereas Zone 3 disease has minimal to no sequelae. Surgical advances in laser and cryotherapy have mitigated poor outcomes. SEE ALSO: Age-Related Macular Degeneration; Diabetic
Eye Problems; Eye Diseases(General); Onchocerciasis; Retinal Disorders; Tay-Sachs Disease; Vitamin A Deficiency. BIBLIOGRAPHY. Joe G. Hollyfield, ed., et al., Retinal De-
generative Diseases and Experimental Therapy (Springer, 1999); Jack J. Kanski, Retinal Disorders (ButterworthHeinemann Medical, 1997); Keith M. Zinn, Clinical Atlas of Peripheral Retinal Disorders (Springer, 1988). Sachin Jain, M.P.H. Rush University Medical Center
Rett Syndrome
Retrospective Study Retrospective studies are epidemiologic studies characterized by an exposure or outcome of interest that has occurred in the past. A retrospective study design enables an investigator or epidemiologist to identify possible associations between exposures and outcomes, but generally not causal relationships. The temporal relationship between exposure and outcome is an essential criterion for judging a causal relationship. Because the events of interest have occurred prior to beginning a retrospective study, biases may affect assessment of both the occurrence and timing of such events. However, retrospective studies are generally less costly and less time consuming than prospective studies. The two most common types of retrospective studies are retrospective case-control studies and retrospective cohort studies. Retrospective case-control studies are characterized by the identification of cases prior to the beginning of the study. Within the retrospective case-control study design, people with the disease of interest (cases) are compared by exposure status to people without the disease of interest (controls). Advantages of retrospective case-control studies include a relatively short time period required for study, a relatively inexpensive study design, and use of a small population. Disadvantages of retrospective case-control studies include occasional difficulty in establishment of a temporal relationship, potential bias in assessment of exposure, occasional difficulty in selection of appropriate controls, incomplete information on exposure, limitation in human recall, and potential recall bias A retrospective cohort study is also called a historical cohort or a nonconcurrent prospective study. The study designs of both the concurrent cohort study and the retrospective cohort study are identical, focusing on a comparison of incidence of disease in an exposed and a nonexposed population. However, in a retrospective cohort study design, historical data are used from the past to reduce the time frame of the study to obtain results sooner. Within the retrospective cohort study design, exposure is usually ascertained from historical records or interviews. Advantages of retrospective cohort studies include less expense than a concurrent cohort study and less time required for study. Disadvantages of retrospective cohort studies include occasional difficulty in establishment of a temporal relationship, susceptibil-
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ity to bias both in assessment of exposure and outcome, information bias in quality and extent of information obtained from exposed and nonexposed people, biases from nonresponse and loss to follow-up, difficulty in selection of nonexposed comparison group, and changes over time in criteria and methods. SEE ALSO: Case-Control Study; Cohort Study; Epidemi-
ologist; Epidemiology.
BIBLIOGRAPHY. Leon Gordis, Epidemiology (Saunders,
2004); Kenneth J. Rothman, Epidemiology: An Introduction (Oxford University Press, 2002).
Rebecca Malouin, Ph.D., M.P.H. Michigan State University
Rett Syndrome Rett syndrome (RS) is primarily a neurological disorder that affects many organ systems. RS was reported first in 1966 by the Austrian pediatric neurologist Dr. Andreas Rett. Most persons with RS are female but it may also inflict males. Before the discovery of RS patients were misdiagnosed. In the developing world RS is under diagnosed and facilities poorly treat this ongoing ailment. RS generally becomes clinically evident by the time the patient is 8 months to 5 years of age. The first symptoms are gross motor development delay, loss of eye contact, deceleration in head growth, lack of weight gain, poor average height, low muscle tone, and hand wringing. Some infants with RS appear placid and calm when compared to healthy infants. These major neurological developmental issues can start in many children at different ages which make diagnosis in underserved areas elusive. Causes Mutations that cause RS are sporadic and the gene for RS was only recently identified as (methyl-CpG binding protein-2 [MECP2]). In a family with one child who has RS, the increased risk of having a second child with RS is reportedly less than 0.4 percent. However, recurrence of RS can occur through such mechanisms as germline mosaicism. This is when the
1490 Reye Syndrome presence of a gene mutation for a disease trait in some yet not all of the parents sexual reproductive cells. Epidemiology In the U.S. a large study found the incidence to be approximately one per 20,000 people. Internationally, incidence varies widely with some reports as high as one per 10,000 live female births to that of Japan with one per 45,000 girls aged 6 to 14 years with RS. These variations in incidence may be from reporting of all variations of RS. These atypical forms include congenital RS, milder forms with later onset of regression, and preserved speech variants. Most patients with RS survive into the fifth or sixth decade of life, often with severe disabilities. After the age of 10 survival rates decline. For example, a 35year survival rate is 70 percent. However, death may be sudden and secondary to pneumonia or other long term illness with such risk factors as seizures, loss of mobility, and difficulties with swallowing. Life expectancy worldwide is favorable in those with RS than in other individuals with profound mental handicap. However, there is an obvious sex relation to RS with that of females as it is X-linked. This means that disease is tied to the X chromosome, which is one of the sex chromosomes that determine gender. Males have one X and one Y chromosome, while females have two X chromosomes. As with many X-linked disease, most males are thought to die while in the womb. However, some cases do exist of males with mutations similar to those found with MECP2 and exhibit RS symptoms. Males with this disorder also show a wide range of symptoms from severe congenital encephalopathy, muscle spasm, involuntary muscle movements and mild mental retardation. Signs and Symptoms Patients with RS initially have what looks like healthy development. In retrospect upon investigation, girls are reported by parents to have been placid as infants, with low muscle tone and subtle slowing of normal development. One clinical feature is slow head growth between 2 to 4 months of age can be common. A period of developmental stagnation is followed by a period of regression. Disease development progresses through 4 stages with physical findings that vary by stage and individual. Stage I is considered developmental arrest and
typically occurs in children aged 6-18 months. Stage II is rapid deterioration or regression and typically happens in children ages 1 to 4 years old. Stage III is pseudostationary and typically in children ages 2-10 years. Stage IV is late motor deterioration and can occur anytime after 10 years of age. Diagnosis Currently, diagnosis of RS is made if the patient meets defined clinical criteria. The diagnosis is supported by a positive mutational analysis of the discussed MECP2 gene. However, as many as one fifth of females meeting the full clinical criteria for RS may have no identified mutation after analysis. Prognosis Because no cure exists for RS, treatment is palliative and supportive. A multidisciplinary approach to care for persons with RS is recommended. This includes treating physiological symptoms as well as social and physical therapy to help with daily events such as working and interacting with their environment. Globally, these needs are not easily met and patients with Rett Syndrome are under treated and suffer accordingly. SEE ALSO: Autism; Child Development; Degenerative
Nerve Diseases; Developmental Disabilities; Ecogenetics; Genetic Disorders; Growth Disorders; Metabolic Disorders; Methylation; Movement Disorders. BIBLIOGRAPHY. D Armstrong, “Review of Rett Syndrome,”
Journal of Neuropathology and Experimental Neurology (v.56/8, 1997); CA Kozinetz, et al., “Epidemiology of Rett Syndrome: A Population-Based Registry,” Pediatrics (v.91/2 1993); Barbro Lindberg, Understanding Rett Syndrome: A Practical Guide for Parents, Teachers, And Therapists (Hogrefe & Huber Publishing, 2006). John Michael Quinn V, MPH University of Illinois at Chicago
Reye Syndrome Reye syndrome is a neurological (brain) and hepatic (liver) dysfunction disorder most often seen in children treated with aspirin just after recovery from a
viral infection. First recognized in the early 1960s, the cause of Reye syndrome has yet to be identified; however, it is believed that the use of aspirin and preceding viral illness are precipitating factors. Although a firm correlation has not been determined between the use of aspirin after viral illness and Reye syndrome, since the Centers for Disease Control and Prevention warned parents not to use aspirin in children (without physician notification and approval), cases of Reye syndrome have drastically declined. Now, cases have been limited to approximately two cases per year since the mid-1990s. Reye syndrome occurs most frequently in children 4 to 12 years of age. It occurs equally in males and females and is strongly associated with the use of aspirin during a viral illness, most specifically the flu (caused by influenza A or B) and the chicken pox (caused by the Varicella Zoster) viruses. Typically, a child has just recovered from a viral illness four to seven days previously and then has a sudden onset of vomiting. Twenty-four to thirty-six hours after the onset of vomiting, children have mental status changes including confusion, lethargy, irritability, restlessness, increased combativeness, or disorientation. As the illness progresses, coma, seizures, respiratory arrest, and death can occur. Children with Reye syndrome have elevation of liver enzymes (alanine aminotransferase and aspartate aminotransferase) typically without jaundice (yellowing of the skin) and fatty degeneration of their liver, which causes metabolic disturbances. Patients also develop noninflammatory cerebral edema (swelling), which elevates the intracranial pressure and puts pressure on the brain causing neurological symptoms. The usual cause of death from Reye syndrome is herniation of the brain from increased intracranial pressure from cerebral edema. The pathophysiology and criteria for diagnosis of Reye syndrome have not been determined. Pathology theories for Reye syndrome involving mitochondrial (a part of each cell that makes energy) damage and hepatic metabolic disturbances have been explored, although evidence is weak. Reye syndrome is a diagnosis of exclusion, meaning many other illnesses should be ruled out as a cause of the symptoms before the diagnosis of Reye syndrome can be made. The patient history of viral illness and aspirin use is helpful information. A thorough physical exam, several labo-
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ratory tests, head imaging, and liver biopsy are also done at the physician’s discretion. Symptoms of Reye syndrome were staged in 1981 by the National Institutes of Health. Stage 1 describes the patient as lethargic, following verbal commands with normal posture, response to pain, and pupillary responses. Stage 2 describes combative behavior with inappropriate verbalizations, normal posture, normal or abnormal response to pain, and sluggish pupillary reactions. Stage 3 describes the patient as being in a coma with abnormal posturing, response to pain, and pupillary reaction. Stage 4 describes stage 3 with increased pupillary and ocular response abnormalities. Stage 5 indicates the patient is nonreactive in all ways including pupillary/ocular responses. All patients with Reye syndrome should be admitted to the hospital for evaluation and categorized into one of the five stages listed above. Treatment in stages 1 and 2 include constant observation and evaluation of neurological status, as well as supportive treatment of electrolyte abnormalities and fluid replacement. Patients in stages 3 to 5 are placed under constant monitoring of breathing and tissue perfusion, metabolic disturbances are identified and corrected, and great care is taken to decrease cerebral edema. Reduction of the increased intracranial pressure is a high priority because its decline can directly influence the patient’s survival. Recommendations include placing a device (catheter) in the patient’s brain to monitor pressure. Treatments for elevated intracranial pressure include medications such as steroids, mannitol, and furosemide, or use of the inserted catheter to release small amounts of fluid from around the brain. The prognosis of patients with Reye syndrome relates most directly to cerebral edema. Mortality has decreased to approximately 20 percent with past mortality being 31 percent during the 1980s to 1990s. Patients with metabolic disturbances, rapid progression of symptoms, involvement of liver and muscle tissues, and those with low protein levels have the poorest prognosis. Complications of Reye syndrome include coma and neurological deficits. Neurological deficits are present in approximately 10 percent of survivors with the least deficits being in those classified as stage 1. Most long-lasting neurological complications occur in patients having Reye syndrome under the age of 2 or patients who experienced high ammonia levels during the illness.
1492 Rheumatic Heart Disease SEE ALSO: Cirrhosis; Hepatitis; Influenza; Neurologic
Diseases (General); Pathology; Physiology.
BIBLIOGRAPHY. Centers for Disease Control and Preven-
tion, “CDC Study Shows Sharp Decline in Reye’s Syndrome among U.S. Children,” www.cdc.gov (cited April 2007); Lisa Danzig and Keiji Fukuda, “Influenza,” in Current Diagnosis & Treatment in Infectious Diseases (McGraw-Hill, 2001); Susan Fuchs, “Altered Mental Status and Coma,” in Pediatric Emergency Medicine a Comprehensive Study Guide, 2nd ed. (McGraw-Hill, 2002); James P. Keating, “Reye Syndrome,” in Textbook of Pediatric Infectious Diseases, 4th ed. (W.B. Saunders, 1998); Vinay Kumar, et. al., “Drug and Toxin Induced Liver Disease,” Robbins and Cotran Pathologic Basis of Disease, 7th ed. (Elsevier, 2005); Rebecca Matsakas “Reye’s Syndrome,” in Primary Pediatric Care, 4th ed. (Mosby, 2001); National Institutes of Health Consensus Development Conference, “Diagnosis and Treatment of Reye’s Syndrome,” Journal of the American Medical Association (v.246/2441, 1981); National Institute of Neurological Disorders and Stroke, “Reye’s Syndrome Information Page,” www.ninds.nih.gov (cited April 2007); National Reye’s Syndrome Foundation, “What Is Reye’s Syndrome?” www.reyessyndrome.org (cited April 2007); Benjamin W. Van Voorhees, “Reye Syndrome,” www.nlm.nih.gov (cited April 2007); Debra L. Weiner, “Pediatrics, Reye Syndrome,” www.emedecine.com (cited April 2007). Angela Garner, M.D. Megan Garcia University of Missouri–Kansas City
Rheumatic Heart Disease Rheumatic heart disease is a condition in which the heart valves are damaged by rheumatic fever (RF). It is an inflammatory disease caused by a bacterial infection. It can affect most connective tissues, especially those of the heart, joints, brain, and skin. Acute RF is common; however, it commonly occurs in children between 5 to 15 years old. Although the incidence of RF has declined sharply in many developed countries, the disease remains a major public health problem in many developing countries. An untreated group A streptococcal pharyngitis infection is the antecedent event that precipitates
RF. Proper antimicrobial treatment of streptococcal pharyngitis with eradication of the organism virtually eliminates the risk of RF. Rheumatic heart disease can involve any part of the heart. Rheumatic carditis is an infection affecting the endocardium, myocardium, and pericardium to various degrees. RF causes valvular heart disease by an autoimmune phenomenon whereby antibodies against streptococcal antigens cross-react with valvular tissue. The mitral and aortic valves are the most common valves involved. Clinically, rheumatic carditis is almost always associated with a murmur of valvulitis (an extra sound, which can be caused by the passage of blood through a damaged valve). Healing of the rheumatic valvulitis may cause fibrous thickening and adhesion, resulting in the most serious complications of RF: valvular stenosis and regurgitation. A stenotic valve cannot open completely, so blood is pumped through a smaller-thannormal opening. A valve also may not be able to close completely; this leads to regurgitation (blood leaking back through the valve when it should be closed). Eventually, damaged heart valves can lead to serious cardiac problems. Their severity depends on the extent of the damage and the location of heart valves affected. The most serious condition is congestive heart failure in which the heart muscle is weakened and is not able to fully pump blood out of the heart to the rest of the organs. The best strategy against rheumatic heart disease is to prevent RF from occurring. This can be achieved by treating streptococcal pharyngitis with penicillin or other appropriate antibiotics. People who already have RF are more susceptible to recurrent infectious episodes and consequent heart damage. Therefore, these patients are given continuous monthly or daily antibiotic treatment. Patients with myocardial damage caused by RF are given prophylactic antibiotics for dental and surgical procedures. These measures help prevent bacterial endocarditis, a dangerous infection involving the lining of the heart and valves. SEE ALSO: Bacterial Infections; Cardiologist; Cardiology;
Heart Diseases (General); Heart Diseases (Prevention).
BIBLIOGRAPHY. American Heart Association, “Rheumatic
Heart Disease/Rheumatic Fever,” Heart and Stroke Encyclopedia, www.americanheartassociation.com (cited January 2007); E. Braunwald et al., “Rheumatic Fever,” Braunwald’s
Rheumatoid Arthritis
Heart Disease, 7th ed. (Saunders, 2004); D. C. Dale, “Rheumatic Heart Disease,” ACP Medicine 2006 (WebMD Professional Publishing, 2005); D. L. Kasper et al., “Rheumatic Fever,” Harrison Principles of Internal Medicine, 16th ed. (McGraw-Hill Professional, 2004). Hamid Ghanbari Saba Darda Independent Scholars
Rheumatoid Arthritis Rheumatoid arthritis is a chronic disease that is characterized by stiffness, swelling, pain, and loss of motion in the joints. It is primarily characterized by inflammation of the synovium (or lining) of the joints and can lead to long-term joint damage, resulting in chronic pain, loss of function, and significant disability. Although it most commonly affects the joints, it can affect other parts of the body as well. Approximately 0.8 percent of the adult population worldwide is affected with rheumatoid arthritis. Rheumatoid arthritis can affect children, but onset usually occurs between 30 and 50 years of age. It is approximately three times more common in women than men. Over 250,000 hospitalizations and 9 million physician visits per year are attributed to rheumatoid arthritis. Development In a joint, the ends of the two bones that meet are covered by cartilage to allow for easy movement of the two bones. The joint is surrounded by a capsule that protects and supports it. The joint capsule is lined with synovium, which is a type of tissue that produces synovial fluid. Synovial fluid is a clear fluid that lubricates and nourishes the cartilage and bones inside the joint capsule. Rheumatoid arthritis is an autoimmune disease, meaning the body’s own immune system starts attacking itself. In rheumatoid arthritis, the body’s immune system, which normally helps fight off infection, begins attacking the joint tissues. As a result, the synovium becomes inflamed causing warmth, redness, swelling, and pain. As the disease progresses, the inflamed synovium invades and damages the cartilage and bone of the joint which results in a weakening of the mus-
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cles, ligaments, and tendons surrounding the joint. The joint becomes weak and unable to perform normally. The disease can also affect the bones and lead to the development of osteoporosis (a disease in which bones become fragile and are more likely to break). Joints that are normally affected include the smaller joints of the fingers, hands, and wrists. Joint involvement is typically symmetrical, meaning that if a joint hurts on the left hand it is likely that the same joint will also hurt on the right hand. Other parts of the body such as skin, blood vessels, heart, lungs, and muscles can also be affected. People with rheumatoid arthritis experience fatigue, weakness, periodic fevers, and stiffness in the morning or after long periods of inactivity. Other symptoms are anemia (decreased production of red blood cells), neck pain, dry mouth, and dry eyes. Rheumatoid nodules, or lumps of tissue under the skin, appear in about one-fifth of people with rheumatoid arthritis. The extent that rheumatoid arthritis affects people varies from person to person. For some people, rheumatoid arthritis lasts for a relatively short time (a few months up to two years) without causing any detectable damage. Other people will have mild-to-moderate disease throughout their life, with periods in which the symptoms worsen (called flares) and periods in which the symptoms seem to disappear (called remissions). Another subset of people will experience a longer-lasting (many years or a lifetime) and more severe form of the disease which leads to serious joint damage and disability. Causes The cause of this disease is currently unknown. There are many factors that are thought to play a role in rheumatoid arthritis. There does appear to be a genetic (or inherited) component to the disease. Researchers have discovered that certain genes are associated with the development of rheumatoid arthritis. However, the presence of these genes is not predictive of who will have the disease. Some people with rheumatoid arthritis do have not these genes and some people who have the genes do not ever develop rheumatoid arthritis. There are other factors that are theorized to increase risk for rheumatoid arthritis. Some researchers believe that something like a viral or bacterial infection can act as a trigger to initiate the disease process. Other researchers believe
1494 Rheumatoid Arthritis that there are certain hormonal factors that may be involved. As mentioned above, women are approximately three times more likely to get rheumatoid arthritis than men. Typically, the disease will go into remission during pregnancy, but have an increase in symptoms after the baby is born. In addition, women develop rheumatoid arthritis more often in the first year after pregnancy than would be expected in the general population. This has led some researchers to postulate that sex may be one determinant of the development of rheumatoid arthritis. Currently, there are few answers to these questions. Diagnosis In the early stages of the disease, rheumatoid arthritis can be difficult to diagnose for several reasons. First, often only a few symptoms may be present at the early stages of the disease. It may take time for the full range of symptoms to develop. Also, symptoms at the onset of the disease can vary widely from person to person. Some people have more severe symptoms than others. In addition, some symptoms are very similar to those experienced by persons with other types of joint conditions or arthritis. It may take some time to rule out the other causes of the symptoms. Further com-
In rheumatoid arthritis, the body’s immune system, which normally helps fight off infection, begins attacking the joint tissues.
plicating the diagnosis is that there is no one specific test that will determine if a person has rheumatoid arthritis. Because of these factors, a variety of tools are used to diagnose rheumatoid arthritis and to rule out other conditions. Initial assessment of the patient will begin with a thorough medical history. In this interview, the physician will depend heavily on the patient’s description of the symptoms; what the symptoms are and when and how they began. The second step is the physical exam, which will include examination of the joints to identify and characterize joint swelling, tenderness, and loss of motion and muscle strength. In addition, the physician will be looking for signs of rheumatoid arthritis in other organs such as skin, lungs, and eyes. Laboratory tests that may be utilized include a test for rheumatoid factor (a specific antibody that is present in most people with rheumatoid arthritis). Rheumatoid factor, however, does not specifically indicate that someone has rheumatoid arthritis. Some people test positive for rheumatoid factor but never develop the disease. Other people who do have rheumatoid arthritis will not test positive for rheumatoid factor, especially early in the disease process. Therefore, other tests are often used as well. These tests include white blood cell count (to test for infection), anemia, erythrocyte sedimentation rate (often referred to as sed rate), which measures inflammation in the body, and C-reactive protein (also a general measure of inflammation). Finally, the progression of the disease is often monitored by visualizing the degree of joint destruction via X-rays. Treatment The goals of therapy in the treatment of rheumatoid arthritis are to reduce pain and inflammation, slow progression of disease, improve the sense of well-being, and improve ability to function. It is important to note that currently there is no treatment that will cure rheumatoid arthritis. Therapies are directed at decreasing the inflammatory process or at decreasing the body’s immunologic response. There are several classes of drugs as well as nondrug therapy/lifestyle approaches that can be used in the management of the disease. Rest and exercise. People with rheumatoid arthritis need a good balance between rest and exercise. Of-
ten, they need more rest during flares of the disease. Rest helps to reduce joint inflammation and pain and is important in fighting fatigue. Exercise is also important to help maintain strength and joint mobility. It is important for a patient with rheumatoid arthritis to engage in an exercise program that takes into account his or her current abilities and limitations. Joint care. Several devices are available to support and align deformed joints to reduce pain and improve function. Some people find that using a splint to provide support and rest for a painful joint helps to reduce the pain and swelling. Splints are most often used on wrists and hands but can also be used on ankles and feet. Other ways to reduce stress on joints is by using self-help devices (zipper pullers, long-handle shoe horns) and devices to help with getting on and off chairs, toilet seats, and the bed. Stress reduction. People living with rheumatoid arthritis face both emotional and physical challenges. In addition to pain, patients often feel anger, frustration, and fear regarding their physical limitations. Although there is no evidence that stress causes rheumatoid arthritis, stress can adversely affect the way a patient copes with the disease. In addition, stress can affect the amount of pain a person feels. There are several ways in which a person can help to manage his or her stress. Rest and relaxation, participation in support groups, and good communication with the healthcare providers can all help to reduce stress. Drug Therapy Drug therapy options include nonsteroidal antiinflammatory drugs (NSAIDs) and other analgesic drugs, disease-modifying antirheumatic drugs (DMARDs), and biologic response modifiers. NSAIDs are drugs that are used to the reduce pain and inflammation associated with rheumatoid arthritis. Aspirin, ibuprofen, and naproxen are commonly used over-the-counter (OTC) NSAIDs. Other NSAIDs are available by prescription such as indomethacin and celecoxib (Celebrex®). NSAIDs are effective in reducing pain and inflammation but have little to no effect on disease progression. These agents are associated with a wide spectrum of adverse effects. Some problems associated with NSAIDs include stomach problems (stomach ulcers and bleeding), kidney problems, and worsening of asthma.
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There is also another class of drugs that are used to relieve pain without affecting inflammation or progression of the disease process. These drugs are known as analgesics and include acetaminophen, propoxyphene, hydrocodone, and morphine. Steroid drugs such as prednisone are antiinflammatory drugs and can be used to slow joint damage caused by inflammation. Caution must be used when taking these drugs because they can cause weight gain, insomnia, redistribution of fat on the body resulting in an accumulation of fat on the upper back at the base of the neck (called a buffalo hump) and rounding of the face (referred to as moon faces). Also, high doses for long periods can cause severely suppress the immune system, increasing susceptibility to infection and can decrease bone density, resulting in osteoporosis. DMARDs are often used to help slow joint damage. Examples of DMARDs are methotrexate, penicillamine, azathioprine, chloroquine, hydroychloroquine, and sulfasalazine. There are no chemical or pharmacologic similarities between these agents, but clinically, they do share some characteristics. Use of these agents is associated with clinical improvement. They have been shown to facilitate the healing of bone erosions and to slow the development of new bone erosions. Benefit from these agents is delayed as it typically takes weeks to months to notice changes. DMARDs are often used in combination with NSAIDs because NSAIDs are more effective at decreasing pain and inflammation. Biologic response modifiers inhibit proteins called cytokines which contribute to inflammation. By inhibiting these proteins, biologic response modifiers directly modify the immune system. Examples of these drugs include etanercept (Enbrel), infliximab (Remicade), and adalimumab (Humira). Studies have indicated that these drugs are very good at controlling the signs and symptoms of rheumatoid arthritis and slowing the progression of joint damage. The major side effect of these drugs is that they can increase the risk for serious infections. Another type of biologic response modifier is the drug anakinra (Kineret) which blocks a protein called interleukin-1 that is commonly elevated in patients with rheumatoid arthritis. Anakinra has been shown to improve the signs and symptoms of rheumatoid arthritis, to slow progression, and decrease disability.
1496 Rickets The major side of effect of this agent is pain and inflammation around the site of injection of the drug. Surgery Surgery can also play a role in the management of patients with severely damaged joints. Joint replacements can be performed on many joints. The most successful procedures are those done on the hips, knees, and shoulders. Joint replacement often provides pain relief and reduction of disability. Summary Although rheumatoid arthritis can still be a debilitating disease, scientists are making rapid progress in learning about rheumatoid arthritis. They are constantly learning more information about how and why the disease develops, who is most susceptible to getting it, why the disease is mild in some patients but severe in others, and about best treatment strategies for combating the disease. Results from active, ongoing research has led to significantly improved functioning as compared to two decades ago. There is also hope for the future as new technologies such as stem cell transplantation (stem cells have the capacity to develop into specific cell types, which give them the potential to repair damaged tissues upon transplantation) and novel imaging techniques are being developed and applied to the setting of rheumatoid arthritis. All of these advances will bring an improved quality of life for those living with rheumatoid arthritis. SEE ALSO: Arthritis; Juvenile Rheumatoid Arthritis; Pain. BIBLIOGRAPHY. American College of Rheumatology Sub-
committee on Rheumatoid Arthritis Guidelines, “Guidelines for the Management of Rheumatoid Arthritis: 2002 Update,” Arthritis and Rheumatism (v.46, 2002); Rindfleisch and Muller, “Diagnosis and Management of Rheumatoid Arthritis,” American Family Physician (v.72/6, 2005); U.S. Department of Health and Human Services, National Institute of Arthritis and Musculoskeletal and Skin Diseases, “Rheumatoid Arthritis,” www.niams.nih.gov/hi/topics/ arthritis/rahandout.htm (cited May 2004). Mary Peace McRae, Pharm.D., Ph.D. Kansas City University of Medicine and Biosciences
Rickets Rickets develops in children when growing bones do not mineralize. The bones soften and may cause a variety of deformities including growth retardation, dental abnormalities, and bowed legs, or may result in bone pain and fractures. Because vitamin D assists in calcium absorption through specific hormone production, any disturbances with the intake of vitamin D, production of its by-products, absorption, or subsequent metabolism may contribute to the development of rickets. Additionally, ultraviolet light assists in the production of vitamin D through exposure to the skin and conversion therein of specific enzymes. Because melanin filters and absorbs solar radiation, darker skinned individuals may actually require more sunlight exposure to produce the same amount of vitamin D. The most common cause of rickets outside of the United States is a consequence of malnutrition. If there is overall insufficient oral intake, then inadequate nutrition may result, as sometimes seen in countries suffering from famine. However, specific inadequate intake of vitamin D, as sometimes seen in children exclusively breast fed, may also contribute to this lack of nutrition causing rickets. Other etiologies of nutritional rickets include inadequate intake of dietary calcium or phosphorus. It is important to note that other medical conditions can contribute to rickets. Because further enzyme conversions occur within the liver and the kidney, specific renal diseases or biliary tract diseases can cause disturbances in the regulation of calcium and phosphorus. Other malabsorptive diseases involving the absorption of nutrients in the gastrointestinal tract can also contribute to the development of rickets. Additionally, rickets may occur as a result of malignancy when tumors secrete factors affect the kidney causing phosphate wasting and disregulation of hormones necessary for calcium. Side effects of specific medications may also be a factor in the development of rickets. Certain aluminum-containing antacids lead to hypophosphatemia, while loop diuretics and corticosteroids can lead to calcium and phosphorus deficiency. One anticonvulsant, phenytoin/Dilantin, has been found to react with the lack of target organ ability to absorb a hormone necessary for calcium regulation. Patterns of inheritance also exist in the development of rickets. Genetic defects have been found that
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do not allow vitamin D to be absorbed (receptor abnormalities), as well as mutations causing renal wasting of phosphorus resulting in hypophosphatemia. Treatment is based upon the etiology. Although physical examination and laboratory evaluation are necessary for diagnosis, management is based upon correction of the nutritional abnormalities. The bony abnormalities may require surgical intervention, but the underlying cause must be discerned so that optimal bone healing may occur. SEE ALSO: Bone Diseases; Breast Feeding; Celiac Disease;
Cystic Fibrosis; Failure to Thrive; Lactose Intolerance.
BIBLIOGRAPHY. Linda S. Nield, et al., “Rickets: Not a Disease
of the Past,” American Family Physician (v.74, 2006); “Rickets: What It Is and How It’s Treated,” http://familydoctor.org/902. xml?printxml (cited July 2007); Wikepedia, “Rickets,” http:// en.wikepedia.org/wiki/Rickets (cited July 2007). Ann M. Karty, M.D., FAAFP Kansas City University
Rodbell, Martin (1925–98) Born on December 1, 1925, in Baltimore, Maryland, Martin Rodbell shared the Nobel Prize in Physiology or Medicine in 1994 for his 1970s research in the function of G-proteins. Rodbell attended Baltimore City College, a public high school, and then he began studying biology and French literature at the Johns Hopkins University in 1943. Leaving Johns Hopkins to serve as a Navy radio operator during World War II in 1944, Rodbell returned to his studies in 1946, earning his B.S. in biology in 1949. He pursued studies in chemistry for a year after earning his B.S. Marrying Dutch-born dancer and photographer Barbara Ledermann in 1950, the couple moved to Washington where Rodbell began pursuing his Ph.D. in biochemistry at the University of Washington. The couple had four children together. Completing his Ph.D. in 1954, Rodbell began working as a biochemical research assistant at the University of Illinois at Urbana-Champaign. Two years later, he accepted a job as a research biochemist at the Christian
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Anfinsen at the National Heart Institute; this organization is now known as the National Heart, Lung, and Blood Institute (NHLBI), one of the National Institutes of Health (NIH). In 1961, Rodbell began working for the National Institute of Arthritis and Metabolic Diseases, an organization now part of the National Institute of Diabetes and Digestive and Kidney Diseases. Through his research, Rodbell in 1969 could describe components of cell-based communication, calling this process “signal transduction.” Furthermore, he uncovered the function of G-proteins early in the 1970s, which earned him his 1994 Nobel Prize along with Alfred G. Gilman. From 1975 to 1985, Rodbell served as Chief of the Laboratory of Nutrition and Endocrinology. In 1985, he began working at the NIH National Institute of Environmental Health Sciences, promoted to Chief of Section on Signal Transduction in 1989. During his career, Rodbell often worked at overseas laboratories, including the University of Brussels, Belgium, and Leiden University, the Netherlands (1960– 61) and the Institute of Clinical Biochemistry, University of Geneva, Switzerland (1967–68 and 1981–83). Rodbell died on December 7, 1998, from multiple organ failure. SEE ALSO: National Heart, Lung, and Blood Institute
(NHLBI); National Institutes of Health (NIH).
BIBLIOGRAPHY. Tore Frängsmyr, ed., Les Prix Nobel, The
Nobel Prizes 1994 (Nobel Foundation, 1995, http://nobelprize.org/nobel_prizes/medicine/laureates/1994/rodbell-autobio.html (cited June 2007); “The Martin Rodbell Papers,” Profiles in Science, National Library of Medicine, http://profiles.nlm.nih.gov/GG/Views/Exhibit/narrative/ biographical.html (cited June 2007).
Kelly Boyer Sagert Independent Scholar
Roentgen, Wilhelm (1845–1923) Born on March 27, 1845, at Lennep in the Lower Rhine Province of Germany, Wilhelm Conrad Roentgen is best known for discovering the types of rays now called X-rays. His discovery revolutionized medical
1498 Roentgenology practices because doctors could now view the inside of a patient’s body without employing unnecessarily invasive procedures. Roentgen’s family moved to the Netherlands when he was 3 years old; there, he entered the University of Utrecht in 1865, studying physics. Switching to the University of Zurich to study mechanical engineering, he received his engineering degree in 1868 and a Ph.D. in physics in 1869. He married Anna Bertha Ludwig in 1872. The couple had no children of their own, but in 1887, they adopted 6-year-old Josephine Bertha Ludwig, the daughter of Anna’s brother. Roentgen worked as a physics professor at Strasbourg University in 1874 and 1876, the Academy of Agriculture in Wurtemberg in 1875, and at the University of Giessen, starting in 1879. In 1888, he began teaching at the University of Wurzburg, and in 1900, he accepted a job offer from the University of Munich, where he taught through 1920, which was the remainder of his teaching career. He began publishing results of his research projects in 1870. Topics included heats of gases, thermal properties of crystals, electrical qualities of quartz, and other related subjects. In 1895, Roentgen was studying how electrical currents reacted through extremely low-pressure gas; although this was not a new form of scientific endeavor, Roentgen’s research led to the November 8, 1895, discovery that under certain circumstances, the rays created recorded the image of the bones of his wife’s hand. We would now say he had created an X-ray of her hand. Roentgen noted several features of these rays, including the fact that the cathode rays needed to make contact with a material object for their effect to take place and that these rays could travel through paper, wood, and aluminum. The phenomenon of Xradiation has also been called Roentgen radiation. He published three papers on the properties of these rays. Roentgen received a significant number of medals, awards, and honorary doctorates for his discovery, including the first Nobel Prize for Physics, granted in 1901. He died on February 10, 1923, in Munich from intestinal cancer. SEE ALSO: Radiation Exposure; Radiology. BIBLIOGRAPHY. Nobel Lectures, Physics 1901–1921 (Elsevi-
er, 1967); “Wilhelm Conrad Roentgen,” Microsoft® Encar-
ta® Online Encyclopedia 2006, www.encarta.msn.com/ encyclopedia_761555545/Roentgen_Wilhelm_Conrad. html (cited April 2007); “Wilhelm Conrad Roentgen: The Nobel Prize in Physics 1901,” www.nobelprize.org/nobel_ prizes/physics/laureates/1901/rontgen-bio.html (cited April 2007). Kelly Boyer Sagert Independent Scholar
Roentgenology The term roentgenology takes its name from Wilhelm Conrad Röntgen, and refers to study of the rays that developed, now known as X-rays, providing physicians with a new treatment modality, initially for diagnostics and then developing its use for therapy. Röntgen was born in 1845 in Lennep, Germany, and when he was young, his family moved to the Netherlands. He obtained his doctorate from the University of Zurich. He then became a lecturer at Strasbourg University before moving to the University of Giessen, then to the University of Würzburg where he was chair of the physics department, and then to the University of Munich where he remained throughout World War I, even though he apparently planned to migrate to the United States. In 1895, Röntgen, at Würzburg, began testing equipment which was to lead to his discovery of X-rays, the term “x” being used because of the unknown element in it. Indeed, Röntgen, who was awarded the first Nobel Prize for Physics in 1901, stated that he did not want the rays to be named after him. In pathology, the term roentgenology was originally applied to the study and diagnosis using these rays (now called radiology), with the term roentgenologist being defined “in medicine as a physician who specializes in the use of X-rays in the diagnosis and treatment of disease.” However, it was not long before the term roentgenology came to be used to describe the medical problems people suffered as a result of exposure or overexposure to X-rays. Indeed, the term roentgenologist’s cancer came to be applied to a form of cancer which affected the hands of the people who worked with X-rays. This led to a limit placed on the number of X-rays taken of an individual person in
Romania
order to limit his or her exposure. However, it also resulted in medical professionals working with Xrays to take major measures to reduce their exposure. This is affected by use of protective structures, lead shields, and the like, making radiology much safer for the patients and also for the radiologists and their assistants. In the United States, the American Roentgen Ray Society was founded in 1900 and operates from Slatestone Court, Leesburg, Virginia. It serves as the international organization of physicians and scientists working in radiology and related fields. The Society publishes the American Journal of Roentgenology each month. SEE ALSO: Radiation Exposure; Roentgen, Wilhelm. BIBLIOGRAPHY. The American Roentgen Ray Society,
http://www.ascls.org; Otto Glasser, Dr. W. C. Roentgen (Thomas, 1945); Paul N. Goodwin, Edith H. Quimby, and Russell H. Morgan, Physical Foundation of Radiology (Harper & Row, 1970). Justin Corfield Geelong Grammar School, Australia
Romania Romania is located on the Balkan Peninsula in southeastern Europe. It landlocked except for a narrow coastline on the Black Sea. The Danube River forms its southern border. A third of the country is covered by the Carpathian Mountains, a steep and densely-forested region that gives the country its most scenic vistas. Romania became a Communist state in 1947. In 1965 the country was transformed into a police state under the control of the dictator Nicolae Ceausescu; he was overthrown and executed in 1989. Communists were swept from power in 1996, and the country is now a modernizing free-market economy. They were admitted to the European Union in 2007. The population is 22,276,000. With the death rate at 11.81 per 1,000 and the birth rate of 10.67 per 1,000, the population is declining at a rate of 0.127 percent annually. Median age is 36.9 years. Life expectancy is 68.41 years for males and 75.62 years for females.
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Gross national income is $3,830. One-quarter of the population lives below the poverty line. Mortality from infectious or parasitic diseases is low at 1.3 percent, or 15 deaths per 100,000. The adult prevalence rate for HIV/AIDS is under 0.1 percent, but there are signs that there could eventually be a more generalized epidemic. Romania has the secondhighest tuberculosis rate in the European Union, with its 130 cases per 100,000 comparing to a rate of 13 per 100,000 in the rest of Europe. Sexually-transmitted disease is also much higher than EU averages, with 45 new cases of syphilis per 100,000 compared to 3 new cases per 100,000 in the EU. Cardiovascular disease is the leading cause of mortality in Romania, accounting for 61 percent of deaths annually. Cancer affects 1.3 percent of the population and accounts for 15.5 percent of deaths. Overall, Romania seems to have a much lower cancer prevalence than the rest of the European Union, although cervical cancer rates, at 32 cases per 100,000, are ten times higher than the EU average. Respiratory diseases cause another 6 percent of deaths. Two percent of the population has diabetes. Romanians have several risk factors for the development of disease. Over 32 percent of males and 10 percent of females are regular smokers. Twelve percent of men and 5.5 percent of women are obese. While alcohol consumption is lower than the EU average, at 6.2 litres per person per years, it is not insignificant. Drug use is a growing problem, with as much as 1.3 percent of the population of Bucharest believed to be using IV drugs. Use of opiates and marijuana is also common. Child mortality rates have improved dramatically in the last decade, with 16 deaths per 1,000 in infants and 19 per 1,000 for children under 5. Immunization rates are 97 percent or higher. Child abuse and child abandonment are serious problems in Romania. A 2001 survey found that 47 percent of parents admitted to beating their children as punishment. There were believed to be 76,000 abandoned children in 2006, with 27,000 in state-run institutions awaiting placement. Many other children live on the streets. Rural children, especially Roma (gypsy) children, have inadequate access to health care and education. Over 90 percent of the 70,000 child laborers in the country live in rural areas. Trafficking of women and children into sexual slavery is another major problem in Romania, although
1500 Rosacea exact figures on how many fall victim to traffickers is sketchy. The fertility rate for Romanian women is 1.38 children. About 70 percent use contraception. The maternal mortality rate is 17 deaths per 100,000 live births. Almost all births are attended. Domestic violence is seen as a cultural norm. Only 1 in 5 women ever report violence to the police, and there are only 3 shelters in Bucharest, a city of 3 million, to protect women if they choose to flee. In 2005, the state passed a law stating that all bridegrooms must attend a three-day course for anti-violence counseling. Those that take the course received approximately $300; those that refuse cannot obtain a wedding license. Primary care is provided through family practitioners contracted with the National Health Insurance Fund, and who receive their reimbursements as a mix of state-funded insurance and out-of-pocket payments. The referral of a primary care physician is necessary to access secondary or tertiary care within the country’s network of hospitals. The health system is still mostly public, with private practice legal only since 1990. Hampered by political problems and lack of funding, badly-needed reforms have not yet been implemented. Health care for all is garunteed by the constitution, but is not yet the reality for millions who end up paying for much of their care without state assistance. SEE ALSO: Death Rate; Healthcare, Europe. Bibliography. United Nations Children’s Fund, “Ro-
mania—Statistics,” http://www.unicef.org/infobycountry/ romania_statistics.html (cited July 2007); “Romania.” CIA World Factbook. https://www.cia.gov/library/publications/ the-world-factbook/geos/ro.html (cited July 2007); “Romania”. UNAIDS: The Joint United Nations Programme on HIV/AIDS. http://www.unaids.org/en/Regions_Countries/Countries/romania.asp (cited July 2007); “Romania: 10 Health Questions About the New EU Neighbors”. World Health Organization. http://www.euro.who.int/Document/ E88202_Romania.pdf (cited July 2007); The Telegraph (London). April 23, 2005. “Romanian Bridegrooms Forced to Take Anti-Violence Course,” from www.telegraph. co.uk/news/main.jhtml?xml=/news/2005/04/24/wrom24. xml&sSheet=/news/2005/04/24/ixworld.html (cited July 2007); United Nations Children’s Fund “UNICEF Roma-
nia—Country Web site,” http://www.unicef.org/romania/ index.html (cited July 2007). Heather Michon Independent Scholar
Rosacea Rosacea is a disorder that involves the blood vessels, leads to formation of acne-like lesions, and growth of certain glands. The vessels of the central face, including the nose, cheek, eyelids, and forehead, dilate, causing redness. Initially, patients with rosacea have a tendency to flush easily and this can progress to persistent redness. Certain foods, beverages, and changes in mood or temperature may exacerbate the redness. Later, small blood vessels (telangiectasias) and tiny pimples begin to appear on and around the reddened area. Rosacea can sometimes be confused with acne vulgaris; however, in rosacea, there are no blackheads present as in acne. A rhinophyma may form in advanced cases of rosacea due to enlargement of the glands, causing a bulbous, enlarged red nose and puffy cheeks. Rosacea may also involve the eyes 50 percent of the time. Patients may experience conjunctivitis, which is a burning and grittiness of the eyes. Rosacea is a chronic disorder that is best prevented by avoiding irritants and triggers. To avoid further breakouts and progression, the patient must adhere to a pharmacologic regimen for maintenance therapy. Those most likely at risk for rosacea are between the ages of 30 and 60 who have fair skin, light hair, and light eye color. Females experience this disorder more frequently than males. Males are more likely to have advanced cases that will lead to rhinophyma. The etiology of the vessel dilation in rosacea has not yet been ascertained, but some studies have theorized that hair follicle mites—Demodex folliculorum and Demodex brevis—may cause the inflammatory lesions. Some studies show that people with rosacea have more mites in their skin versus the skin of patients who do not have rosacea. Patients with rosacea have increased susceptibility to facial flushing, often provoked by hot drinks, spicy foods, caffeine, and alcoholic beverages. Other aggravating events include extreme temperatures, emo-
Rubella
tional reactions, rubbing the face, and using irritating cosmetics/facial products. The flushing may cause some embarrassment in social settings, and patients may often be told that they have “rosy cheeks.” The first stage of rosacea is characterized by facial erythema and telangectasias. The patient can progress to the second stage, characterized by sebaceous gland growth that leads to papules, pustules, cysts, and nodules. These inflammatory lesions are similar to the ones seen in acne vulgaris, with the exception of a lack of comedones (blackheads). Also, patients with acne usually lack telangiectasias. The patient may also experience burning and stinging sensations of the face. In the advanced stages, there is involvement of the eyes and rhinophyma. Classification of rosacea can aid in treatment. The erythematotelangiectatic subtype is characterized by facial reddening, and also associated with stinging and burning symptoms. The papulopustular subtype is the classic presentation, and is characterized by small papules and pustules, with redness of the middle part of the face. The area around the eyes and mouth are usually not affected. The glandular subtype presents with enlargement of the sebaceous glands. The papulopustular and the glandular can progress to a phymatous subtype, which causes the skin to form nodules and become thick. The final subtype is ocular rosacea, and is characterized by irritation and inflammation of the eyelids (blepharitis) as well as conjunctivitis. This may be confused for a bacterial infection or chemical irritation of the eyes. There is no treatment for rosacea; hence, patients must be educated on the need to control this chronic disorder. Facial erythema is more difficult to treat than inflammatory and ocular lesions. Telangiectasias are treatable with surgery or pulsed laser therapy. Patients with rhinophyma may need surgical correction for a satisfactory result. Patients may be unfairly mistaken for alcoholics, due to their red facial features. Initial therapy includes patient education, avoidance of irritants, and the use of sunscreens. Topical antibiotics and benzoyl peroxide help relieve the inflammatory lesions. For inflammatory lesions of rosacea, topical metronidazole with or without a short course of antibiotics is used. Tetracycline should be used when metronidazole does not help. For rosacea not improving with the above measures, isotretinoin
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may be of benefit. Steroids should not be used, as they may increase erythema with long-term use. There is no specific therapy for the flushing in rosacea patients, but it may help patients to avoid things that trigger the redness. Rosacea is chronic, and patients may have lifelong disease, but the symptoms should be able to be controlled properly. SEE ALSO: Dermatitis; Skin Diseases (General). BIBLIOGRAPHY. McGraw-Hill’s Access Medicine. Rosacea.
Goldstein, B, Goldstein, A. Rosacea. Up to Date 2006; National Rosacea Society, www.rosacea.org (cited July 2007).
Gautam J. Desai, D.O. Amber Sturzenegger Kansas City University Aisha Ahmad, D.O. St. Joseph Mercy of Macomb
Rubella The rubella virus is a Togavirus and also an RNA virus. It causes the infectious disease known by the common names German measles or three-day measles. The virus passes from person to person through droplet transmission. Rubella has an incubation period of 14 to 21 days with an average of 16 days between exposure and illness. Rubella is a mild disease with signs and symptoms of low-grade fever, swollen lymph nodes in the neck and a pink rash of many tiny raised bumps on the face, trunk and extremities. The rash usually lasts no longer than three days; hence the common name threeday measles. The symptoms of rubella are similar to other virus infections like infectious mononucleosis and the pink rash might be mistaken for scarlet fever. The diagnosis of rubella can be confirmed with laboratory tests for rubella virus including fluorescent antibody test a reaction where fluorescing dyes attached to rubella antibodies glow when attached to the rubella antigen from the infected person’s blood and hemagglutination reaction where antigens and antibodies combine to form a clump. The greatest health concern with rubella is to women in the first trimester of pregnancy and may
1502 Russia result in spontaneous abortion of the fetus or Congenital Rubella Syndrome in infants. Infants born to mothers having the infection before the fetus’s organs have developed may result in birth defects including blindness, deafness, congenital heart defects and learning disorders. From 1962-1965 a worldwide epidemic of rubella resulted in 20,000 infants being born with birth defects. Even though the greatest health risk from rubella is in pregnant women, the first attenuated live virus vaccines for rubella were recommended for administration to children. From the first availability of a rubella vaccine in 1969 to 1977, the United States recorded a decrease in rubella cases and in the number of children born with Congenital Rubella Syndrome. By 1978, the changing epidemiology of rubella brought about new recommendations for vaccination to include females of childbearing age, college students, military personnel and healthcare workers and people in other institutional settings. Acquired immunity to rubella is achieved in one of two ways, having the disease or being immunized. Rubella vaccination provides active immunity by stimulating the formation of antibodies. If the virus invades again, the body’s defenses will include an artificially induced memory of having the disease and being able to combat it, rubella antibodies remain in the immune system and will fight off future disease if the person is exposed to rubella. The rubella vaccine is a live/attenuated virus vaccine grown in cell cultures with human diploid cells. The rubella virus is altered enough allow the immunized person’s immune system remain ahead of the infection. Because the rubella vaccine is a live virus, it should not be administered to pregnant women or persons who are immunocompromised. Current U.S. guidelines recommend the administration of rubella virus vaccine, in a combination with measles and mumps, to children aged 12 to 15 months with a second dose at 4-6 years of age or at 11-12 years of age. Proof of immunization for rubella may be required for college matriculation, to work in a healthcare facility and other settings. To prevent birth defects from rubella, physicians remain vigilant in making sure women of childbearing age are immunized, including women coming to the United States from other countries. If record of immunization is unavailable, blood tests can confirm high enough levels of the antibody
to ensure immunity. As a global health issue, to decrease the incidence of rubella worldwide will require the support and participation of countries to include vaccination for rubella. According to a 2003 World Health Organization survey, 57 percent of member countries included rubella vaccination in their vaccination programs. Travel to countries not requiring rubella vaccination persons who have not been immunized risk contracting the disease. See Also: Acquired Immunity; Adult Immunization;
Childhood Immunization; Congenital Heart Disease.
BIBLIOGRAPHY. “Achievements in Public Health: Elimina-
tion of Rubella and Congenital Rubella Syndrome – United States, 1969-2004,” MMWR (March 25, 2005); Dorothy H. Crawford, The Invisible Enemy A Natural History of Viruses (Oxford University Press, 2000); Samuel Shelburne III, MD and Wayne X. Shandera, MD “Infectious Diseases: Viral and Rickettsial”, Current Medical Diagnosis and Treatment (Lange Medical Books, 2004). Lyn Michaud Independent Scholar
Russia The Russian Federation is largest country in the world, and has a population of 142,400,000 (2006), with 421 doctors and 821 nurses per 100,000 people. It has its origins, historically, in the Russian Empire which lasted until 1917 when it was replaced by a series of republics which joined to form the Union of Soviet Socialist Republics—the Russian Soviet Federated Socialist Republic being the largest constituent member. In 1991 the members of the Soviet Union split to form fifteen different countries, with Russia being the largest country to emerge. Traditionally, herbal cures were used by the Russians to treat many ailments. For many problems often drastic surgery was used to cut away infected areas. However health care was fairly primitive until the eighteenth century when German surgical procedures had a large impact on Russian health care. There were also large numbers of British and French doctors who moved to Russia where they treated wealthy Rus-
sians. It was not long before lucrative private practices were being operated by Russian and foreign doctors in most cities in Russia, although the main Russian medical facilities of the Russian School of Therapeutics in Moscow were destroyed in 1812. They were rebuilt soon afterwards but with the focus moving to St. Petersburg, the Imperial family and others at court quickly attracted more foreign medical professionals, with local medical schools resulting in many thousands of doctors being trained. The Botkin family became court physicians, with Sergei Botkin being appointed as court physician to Tsars Alexander II and Alexander III. His son, Dr. Eugene Botkin, was physician to Tsar Nicholas II and was killed with the imperial family in 1918. By the time of the Russian Revolution, most of the doctors in Russia were Russians, with Boris Pasternak’s novel Dr. Zhivago (1957) encapsulating some of the problems that doctors faced during the Revolution and the subsequent Civil War. During that period many medical professionals fled the country, and during the late 1920s there were major problems trying to get the health services together again. The Russian Pharmacological Association was established in 1928. The purges of the 1930s led to many doctors being deported or killed, and the hospitals were grossly understaffed at the start of World War II. Under the rule of Josef Stalin there was a quantitative expansion of the health services with the aim of providing free, qualified medical practitioners to care for all the people in the country, even though the service lagged a little in the countryside. In 1948 Stalin mentioned the “Doctors’ Plot” by which several Jewish doctors were alleged to have plotted to poison the Soviet leadership—this was later found to have been untrue. The restructuring of the Soviet medical services started in 1944 with the formation of the Russian Academy of Medical Sciences. This was followed by the creation of many medical societies. These included the Federation of Anaesthesiologists and Reanimatologists (founded in 1991 from the All-Union Society of Anaesthesiologists, founded in 1959); the National Immunological Society (founded in 1983); the National Opthamological Society; the National Pharmaceutical Society; the National Scientific Medical Society of Endocrinologists; the National Scientific Medical Society of Forensic Medical Officers; the National Scientific Medical Society of Hy-
Russia
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The Kremlin (above) in Mosow has been the tradiational center of power in Russia, and the source of public health policy.
gienists; the National Scientific Medical Society of Infectionists; the National Scientific Medical Society of Nephrologists (founded in 1969); the National Scientific Medical Society of Obstetricians and Gynecologists; the National Scientific Medical Society of Pediatricians; the National Scientific Medical Society of Physicians-Analysts; the National Scientific Medical Society of Roentgenologists and Radiologists; the National Scientific Medical Society of Surgeons; the National Scientific Medical Society of Toxicologists; the Russian Gastroenterological Association (founded in 1995); the Russian Neurosurgical Association; the Russian Oncological Society (founded in 1954); the Russian Society of Medical Genetics (founded in 1993); and the Society of Cardiology (founded in 1958). The Russian Medical Association currently has 262,000 members. The hospital service was considerably enlarged during the 1960s and 1970s, and Soviet government
1504 Rwanda literature made regular mention of the free health services operating in the Soviet Union and many doctors and medical students from the Third World trained in the Soviet Union, especially in Moscow and Leningrad (St. Petersburg). As well as 23,500 hospitals (with 3.6 million beds) in the mid-1980s, there was a considerable medical infrastructure with clinics, midwives and pharmacies throughout the country. At the height of the Soviet health service in the early 1980s there were as many as 40,000 polyclinics, which were the primary method of providing health care to up to 90 percent of the population. There were also 15,800 sanatoriums and rest homes which provided care for 50.3 million people. Even though the health services lagged those in the west, their level of coverage, and that they were all free, was impressive. The Soviet government also established sanitariums in some parts of the country, especially in southern Russia, and near the Black Sea in what is now the Ukraine. There was also a network of psychiatric hospitals, and human rights groups in the West often alleged that psychiatry was abused for political purposes with the psychiatric hospitals used for the incarceration of political opponents. There were also allegations of the use of psychiatric drugs for treating dissenters. Estimates of the number of people held in psychiatric facilities for political reasons varied from one to several thousand. One of the problems of the Russian health system during the period of the Soviet Union was that with a budget of 18 billion roubles, a vast bureaucracy was created. Many large enterprises ran their own hospitals with factories, universities and research facilities all running their clinics, rest homes and sanatoriums. Health problems in Russia have varied considerably. The cold weather has caused many cases of frostbite and exposure. Poor hygiene, especially in the south, has led to cholera, typhoid and tuberculosis, although most of these problems have been overcome during the period of the Soviet Union. There were many cases of venereal disease, and there was a large increase in drug addiction from the late 1980s. In addition there was a rise in the number of HIV/AIDS cases. The collapse of the Soviet Union saw the closure of many government hospitals and clinics. In addition, many large companies and enterprises were taken over by private owners who closed down hospitals and clinics, providing extra strain on the government
medical services. Initially there was a period when many people went without adequate health care. However gradually during the presidency of Vladimir Putin, the health care system was improved and patients started receiving better treatment. Russia now has one of the highest doctor to population ratios in the world. See Also: China; Healthcare, Asia and Oceania; Health-
care, Europe; United States; United Kingdom.
BIBLIOGRAPHY. W.J. Bishop, “English Physicians in Russia
in the Sixteenth and Seventeenth centuries,” Proceedings of the Royal Society of Medicine Section of the History of Medicine (v.23, 1929-1930); John F. Hutchinson, Politics and Public Health in Revolutionary Russia 1890–1918 (Johns Hopkins University Press, 1990); Gordon Hyde, The Soviet Health Service: A Historical and Comparative Study (Lawrence & Wishart, 1974); Jaroslav Nemec, “Legal Medicine in the Soviet Union: Brief History of its Origins, Organization and Teaching,” International Symposium on Society, Medicine and Law (Jerusalem, March 1972); D.M. Rossiski, “The Study of the History of Medicine in Russia: An Historical Outline,” Bulletin of the History of Medicine (v.21, November-December 1947); Norah H. Schuster, “English Doctors in Russia in the Early Nineteenth Century,” Proceedings of the Royal Society of Medicine Section of the History of Medicine (v.61, February 1968); Henry Ernest Sigerist, Medicine and health in the Soviet Union (Citadel Press, 1947). Justin Corfield Geelong Grammar School, Australia
Rwanda Rwanda is located in the east-central region of Africa, surrounded by Uganda, Burundi, the Democratic Republic of the Congo, and Tanzania. Once a colony of Belgium, it became an independent nation in 1962. Rwanda is today in recovery from a horrifying episode of genocide in the spring and summer of 1994, which killed 800,000 and displaced another 2 million. Among it’s other impacts, the genocide decimated the already-fragile economy, and continues to suffer high poverty rates, particularly among women and children.
The current population of Rwanda is 9.9 million, and is growing at 2.77 percent annually. Rwanda has a high birth rate, with 40.06 births per 1,000 population, with a fertility rate of 5.37 children born per woman. Median age is 18.6, with 42 percent of the population under 15. Life expectancy is just 47.87 years for males and 50.16 years for females. Malaria, gastrointestinal diseases, and tuberculosis are the leading killers in Rwanda today. Only 42 percent of the population has access to sanitary waste facilities, and 74 percent have safe drinking water. Dysentery, hepatitis, typhoid, and schistosomiasis are endemic in many areas. HIV/AIDS and tuberculosis have also emerged as a major problem within Rwanda. With an adult prevalence rate of 3.1 percent, the country is not the hardest-hit nation in the region. However, 190,000 Rwandans are living with the disease, and at least 21,000 have already died from it. The government has launched aggressive educational campaigns to try to stem the spread of the virus. Malnutrition afflicts a large portion of the population. A long-standing drought across East Africa has reduced crop yields across large parts of Rwanda. UNICEF estimates that 23 percent of Rwandan children under the age of five are underweight, and 45 percent show moderate to severe stunting. Kwashiorkor, an often fatal form of malnutrition stemming from a lack of protein-based calories, is common among children today. Lack of food is not the only problem faced by Rwandan children. The 1994 genocide, the AIDS epidemic, and the general chaos of life in post-war Rwanda have left and estimate 820,000 orphans. Thirty-five percent of children between the ages of 5 and 14 are in the labor force. Twenty percent marry before the age of 18. More than a decade after the genocide, hundreds of primary schools remain
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closed, and those that are open are often poorly staffed. Women also continue to suffer in post-war Rwanda. Only 17 percent have access to birth control. About 94 percent receive some prenatal care, but only 39 percent have a trained assistance during childbirth. The maternal mortality rate is 1,400 deaths per 100,000 live births. Rwandan women face a one in 10 chance of dying in childbirth. The healthcare sector has not yet recovered from the 1994 war. Many facilities destroyed in the fighting have yet to reopen, and a large number of medical personnel who left during the genocide have not returned. Staffing remains low and key drugs and equipment is lacking. It is estimated that more than 50 percent of the population no access to health care facilities. Many have to rely on local witch doctors, called umufumu, for treatment. Other go to the many nongovernmental agencies working within the country, including UNICEF, the International Red Cross, Doctors Without Borders, and other groups. See Also: AIDS; Healthcare, Africa; Nutrition. BIBLIOGRAPHY. “Rwanda—A Cultural Profile Project,”
Health Care in Rwanda, www.cp-pc.ca/english/rwanda/index.html (cited June 2007); “Rwanda: UNAIDS Country Profile”. UNAIDS: The Joint United Nations Programme on HIV/ AIDS, www.unaids.org/en/Regions_Countries/Countries/ rwanda.asp (cited June 2007); “Situation Reports: East Africa Drought, FEWS Rwanda Food Security Outlook—March to July 2007,” ReliefWeb Famine Early Warning System, www.reliefweb.int (cited June 2007); “UNICEF—Rwanda—Statistics,” UNICEF, www.unicef.org/infobycountry/ rwanda_statistics.html#29 (cited June 2007). Heather K. Michon Independent Scholar
S Sabin, Albert (1906–93) Born on August 26, 1906, in Bialystok, Poland, to Jacob and Tillie Sabin, Albert B. Sabin is known for his discovery of the live polio vaccine now used in the United States and around the world. It has been estimated that in the first two years of global use of Sabin’s vaccine, half a million lives were saved and 5 million people avoided contracting polio. Sabin and his family immigrated to the United States in 1921 where he began attending medical school in 1926; in 1931, Sabin earned his medical degree from New York University. His early research on the polio virus was forwarded to the National Foundation of Infantile Paralysis and he worked at the Rockefeller Institute for Medical Research until he moved to Cincinnati in 1939 to teach at the University of Cincinnati. During World War II, Sabin—serving in the U. S. Army Medical Corp—helped develop a vaccine against dengue fever (Japanese encephalitis) used on 65,000 military personnel. After the war, Sabin developed a polio vaccine using a live virus, in contrast to the dead polio virus used in the Jonas E. Salk vaccine. With Salk’s virus, doctors needed to give booster injections to keep the immunity current; Sabin, meanwhile, experimented during the 1950s with a live oral polio virus pill. He
tested the pill first on himself and then on a test group from 1955 to 1957. From 1957 to 1959, the Soviet Union and other Eastern bloc nations used Sabin’s oral vaccine, while the United States still used Salk’s injection. In 1960, Sabin’s vaccination was used on 100 million European children; from 1962 to 1964, approximately 100 million people in the United States received Sabin’s vaccine. In the 1970s, Sabin focused on cancer research in Israel and in the United States. In 1974, he was appointed Distinguished Research Professor of Biomedicine at the Medical University of South Carolina; and from 1984 to 1986, he served as the Senior Expert Consultant at the Fogarty International Center for Advanced Studies in the Health Sciences of the National Institutes of Health. Sabin was awarded 46 honorary degrees worldwide, and he received the Presidential Medal of Honor in 1986. He died on March 3, 1993. SEE ALSO: National Institutes of Health (NIH); Polio and
Post-Polio Syndrome.
BIBLIOGRAPHY. Seymour “Sy” Brody, “Albert Sabin,” Jew-
ish Virtual Library, www.jewishvirtuallibrary.org/jsource/ biography/Sabin.html (cited March 2007); “The Legacy of
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1508 Sabin, Florence R. Albert B. Sabin,” Sabine Vaccine Institute, www.sabin.org/ about/sabin_legacy.html (cited March 2007). Kelly Boyer Sagert Independent Scholar
Sabin, Florence R. (1871–1953) Born on November 9, 1871, in Central City, Colorado, to George K. and Serena Miner Sabin, Florence Rena Sabin became the first female faculty member in 1902—and the first female full professor in 1917—at the Johns Hopkins School of Medicine. There, she taught embryology and histology (the study of tissues). Through her research, she was able to provide an understanding of lymphatic system processes; perfect supravital staining techniques to allow the study of living cells; and contribute significantly to knowledge about the tuberculosis bacteria. Sabin’s mother died when she was 7, so she was raised by her uncle, Albert, and her grandparents. Sabin attended the Vermont Academy, excelling in math and science. At Smith College, she earned a B.A. in zoology in 1893 and was encouraged to study medicine at Johns Hopkins, a newly coeducation facility. Entering Johns Hopkins in 1896, she was 1 of 14 female students in a class of 45 students overall. Mentored by anatomist Franklin P. Mall, Sabin created a three-dimensional model of a newborn baby’s brainstem and she investigated the development of the lymphatic system. After Sabin won a research fellowship from the Baltimore Association for the Promotion of University Education for Women, she began publishing her research results. While at Johns Hopkins, Sabin also investigated the origins of blood vessels and cells and connective tissue. Chosen as the first female president of the American Association of Anatomists in 1924, she was chosen as the first female member of the National Academy of Sciences in 1925, the same year that she was appointed as a member of the Rockefeller Institute. There, she headed the cellular immunology section; in that capacity, she and her research team worked with the Medical Research Committee of the National Tuberculosis Association. During her 13 years at Rockefeller, Sabin made major contributions to the understanding of tuberculosis.
Retiring in 1938, Sabin continued to serve on advisory committees and, in 1944, she began chairing the Health Committee of Colorado’s Post-War Planning Committee; the health bills resulting from this committee became known as the Sabin Program. Postwar, she chaired the Interim Board of Health and Hospitals of Denver. Sabin died on October 3, 1953, in Denver. SEE ALSO: Immunology; Tuberculosis. BIBLIOGRAPHY. “Dr. Florence Rena Sabin,” Changing the
Face of Medicine, www.nlm.nih.gov/changingthefaceofmedicine/physicians/biography_283.html (cited June 2007); “The Florence R. Sabin Papers,” Profiles in Science: National Library of Medicine, http://profiles.nlm.nih.gov/RR/Views/ Exhibit/narrative/biographical.html (cited June 2007). Kelly Boyer Sagert Independent Scholar
Sachs, Jeffrey (1954– ) Jeffrey Sachs is a luminary of the economic development world, particularly following his publication of The End of Poverty—Economic Possibilities for our Time. No dry technical tome, through this book Sachs argues that, with the correct economic and development policies, extreme poverty can be eliminated within the next few decades. He emphasizes his belief that, contrary to much developmental economic orthodoxy, Africa is not a ‘failure’ economically due to poor leadership, but rather due to geographic isolation, a high infectious disease burden, and its tropical climate—a phenomenon he dubs ‘economic geography’. Although Sachs is certainly not anti-free-market, he maintains that in some countries, the level of economic development is so low that market-based development will never succeed in lifting citizens out of poverty—in essence, these nations are caught in a “poverty trap”. In these areas, rather than hoping that private market economic development and foreign investment will cure poverty, Sachs advocates aidbased solutions that focus on preventing infectious diseases and promoting health as a means to promote development; canceling foreign debt and encourag-
Safety (General)
ing sound macroeconomic policy on a national level; and concentrating on investments in education, environmental protection, and infrastructure as a way of promoting sustainable development. In particular, he states that developed-world governments should raise their annual foreign aid budgets to 0.7 percent of GNP, and that aid should be spent only on countries that promote good governance. While applauded by many, Sachs is not without detractors, especially those that protest his argument that Africa and other developing nations can only escape poverty via a massive increase in foreign aid. Sachs first came to attention in the 1980s as a macroeconomic advisor to the Bolivian government, which was facing massive inflation. He also advised newly democratic governments in Eastern Europe, especially in Poland and Russia, as they moved toward a market economy. Born in 1954, Sachs earned B.A., M.A., and Ph.D. degrees in economics from Harvard University. He taught at Harvard for over twenty years before moving to Columbia University in 2002 to become director of the Earth Institute, a think tank focusing on global sustainable development. He is also currently the director of the U.N. Millennium Project, which focuses on meeting the U.N. Millennium development goals of reducing extreme poverty, disease, and hunger by 2015. See Also: Disease and Poverty; Third World. BIBLIOGRAPHY. William Easterly, The White Man’s Bur-
den (Penguin Press, 2006); Jeffrey Sachs, The End of Poverty (Penguin Press, 2005).
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Decisions about risk involve the individual ‘s gender, age, and health status and the task considred.
freedom from danger, injury, or damage; security. …” Effective safety and health management is the knowledge of how to identify and control hazards and the making of key decisions to promote safety. Risks and Hazard Safety is generally understood as inhibiting a significant impact on risk of injury or damage to property. A hazard is anything that has the potential to cause harm. Hazards can affect people, property, and processes. For example, occupational risk refers to the likelihood of an injury or an illness due to the exposure to a hazard.
Safety (General)
Risk Management A systematic application of policies, procedures and practices to establish risk approach. It is the process of measuring and assessing the risk and the development of strategies to manage it. Strategies are transferring the risk, avoiding the risk, reducing the effect of the risk, and accepting some consequences of a risk.
Safety is the condition of being protected against physical, social, spiritual, financial, political, emotional, occupational, psychological, educational, or other types or consequences of failure. The term safety is very often used, and according to the Webster’s New World Dictionary, the definition can be given as follows: “ … the quality or condition of being safe;
Risk Assessment The main aim of risk assessment is to protect people’s health and safety. Risk assessment helps to minimize the possibility of individuals being harmed due to any activities. For example, in business and industry, all employers need to carry out regular risk assessments. Risk assessment can be performed as follows:
Annie Dude University of Chicago
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Safety (General)
• Collecting information: location of workplace, properties of workers, work equipment, materials used, tasks performed by employees, hazards already identified, risks of already-existing hazards, prevalance accidents, legal conditions, technical data of the equipment, work manuals, measurements of hazardous and strenuous factors at the workplace, records of work accidents and occupational diseases, observation of the environment, tasks performed at the workplace, tasks performed outside the workplace, and interviewing employees. • Identifying hazards • Assessing risk caused by hazards (estimating the probability and severity of results and deciding whether risk is acceptable): each identifed should be classified according to small-, medium-, or high-risks categories. To make a decision, probabilities like highly improbable (should not occur during the entire exposure period of a person), probable (may occur only a few times during the exposure period of a person), moderately harmful (accidents and illnesses not causing prolonged distress), medium harmful (accidents and illnesses causing moderate but prolonged or periodically recurring distress), extremely harmful (accidents and illnesses causing heavy and permanent distress and/or death). Further steps at this stage is to decide if the risk arising from a hazard would be acceptable. It should be remembered that the risk assessment should be performed together with the person under risk actively. Decision on risk should be done with the involvement of the person under risk and this persons’ gender, age, and health status should be considered. • The planning of actions to reduce risk: After reviewing the assessment, a high-risk and unacceptable situation should be eliminated or reduced as soon as possible. If the risk is at medium level and assessed as acceptable, actions to reduce its level should be planned. And if the risk is small and assessed as acceptable, it is necessary to ensure that it will remain at the same level. Preventive and protective measures should be implemented in the following order of priority: • Eliminate hazard/risk • Minimize hazard/risk through organizational measures
• Minimize hazard/risk through collective protective measures • Reduce risk through appropriate personal protective equipment • The documentation of risk assessment: Basic information should be recorded appropriately (name and address, name of the assessed place, name[s] of person[s] at the assessed place, date of the assessment, and the name[s] of person[s] conducting the assessment). • Recording identified hazards. For each identified hazard: preventive/protective measures, results of risk assessment, and actions planned to reduce risk should be recorded. Safety Measures Activities and precautions to improve safety or reduce risk. Safety measures may include examination for risk situations, examination for flaws, X-ray analysis, analysis of samples, crisis situations, determining safety limits, implementation of standards and procedures, education and training of human resources and consumers, user manuals, visual aids and tools, laws and regulations, ethical statements, physical examination of person, periodic examinations, using protective equipment, and so forth. Standards Organizations Standards organizations prepare safety standards. These may be voluntary organizations or government agencies which are sometimes called standards body, standards development organization (SDO). These are developing, coordinating, promulgating, revising, amending, reissuing, interpreting, or otherwise maintaining standards. Standards organizations such as the American National Standards Institute (ANSI), U.S. Consumer Product Safety Commission (CPSC), U.S. Department of Labor Occupational Safety and Health Administration (OSHA), International Atomic Energy Agency Safety Standards are formed by industry and governmental bodies to establish a committee to study safety issues and propose standards. Those standards are then reviewed and adopted by the SDO. Many government regulations require that safety products sold or used must comply with a particular SDO standard. Safety standards are also developed by governmental bodies such as the Food and Drug Administration (USA), Health and Safety Executive
(UK), National Public Safety Commission (Japan), National Transportation Safety Board (USA), and Royal Society for the Prevention of Accidents (UK). Basic Safety and Health Management Principles This approach starts with the commitment from the managerial and administrative level. Management commitment can be identified by the availability of a written safety and health policy, the identification of resources to achieve safety, the descriptions of jobs and tasks that define safety and health responsibility, and understanding that fulfilling those responsibilities is a condition of employment. Furthermore, procedures to evaluate workers’ safety performance and methods to correct unsafe work practices are needed. Employees need to be supervised by a competent person. Supervisors have to be accountable and responsible for applying safety and safe environment practices. To ensure safe environment and working conditions, employees or people at risk should have an opportunity for safety and health policy training. People should receive training before exposure to the risky environment. The training process should consider their level of skills and language. All trained persons should be competent after training and be able to perform assigned jobs safely and control hazards, be knowledgeable on specific procedures and safety requirements, be able to maintain equipment required for their tasks, and be aware of safety and health rules of their tasks. Accountability must be strenghtened by developing a written disciplinary policy that has safety expectations, by holding supervisors responsible for enforcing attitudes for safety and health. People under risk should be actively involved on a daily basis to keep the site safe. Inviting and having them attend safety meetings is an effective way. Rules of risk assessment may apply here as well. At least once a year, safety and health effort of the environment and people at risk should be evaluated for safety and health effort. Patterns in injuries, illnesses, and near misses should be investigated. Programs affecting people at risk should be reviewed and they should be current and effective. SEE ALSO: Occupational Health; Occupational Injuries;
Occupational Medicine; Occupational Safety and Health Administration (OSHA).
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BIBLIOGRAPHY. European Agency for Safety and Health at Work, http://hwi.osha.europa.eu (cited May 2007); “Safety,” http://en.wikipedia.org/wiki/Safety (cited May 2007); U.S. Department of Labor. Occupational Safety and Health Administration, “Safety & Health Management Systes eTool,” www.osha.gov/SLTC/etools/safetyhealth/userguide.html (cited May 2007).
Hakan Yaman, M.D., M.S. Akdeniz University
Saint Kitts and Nevis Saint Kitts and Nevis, also known as the Federation of Saint Christopher and Nevis, is a country comprised of two small islands in the Leeward chain of the Carribean Sea. The islands were settled by the British between 1624-28. The federation won independence in 1983, although it remains a member of the Commonwealth Realm with Queen Elizabeth II as its head of state. In 1998, Nevis made a bid to secede from the union, but failed to win the needed two-thirds majority. The population of the islands are slightly over 39,000, growing at just 0.62 percent annually. This slow growth is driven by a population outflow, as more and more Kittitians and Nevisians leave the islands in search of better opportunities abroad. For those that stay, life expectancy is high, with the average male reaching 70 and the average female reaching 76. Infant mortality and child mortality are fairly low, at 18 deaths per 1000 for infants and 20 per 1000 for children under 5. Maternal mortality is almost non-existent. The economy of Saint Kitts and Nevis was dependent on the cultivation of sugar cane through most of their history, but after years of financial loss the industry shut down in 2005. The islands now rely mainly on tourism. While agriculture is still practiced on the islands, most food has to be imported, which combined with the 9 percent inflation rate leads to high prices for some, and may be spurring poor nutrition among some islanders. Health officials note that between 1991–1995, an average of 6.6 percent of island children were considered moderately underweight, an average of 6.7 percent were moderately overweight. Saint Kitts and Nevis suffer from a few remaining communicable endemic diseases, including gastro-
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Saint Lucia
enteritis, dengue, and tuberculosis. Most have been brought under control through an integrated system of inspection, environmental control, education and information-sharing. Virtually all islanders have access to safe drinking water and sanitary facilities, further reducing the risk. Immunization programs for children are fairly robust, and outbreaks of common childhood diseases are rare. Lifestyle issues play a role in the health of Kittitians and Nevisians. Violence and crime increased 49 percent between 1990 and 1994. Teenage pregnancy is common, and there is a high percentage of drug use by the young. Smoking and tobacco use is also prevalent. There have been some cases of HIV/AIDS on the islands, but it is relatively rare. Adult morbidity and mortality is driven by noncommunicable diseases such as cardiovascular disorders and diabetes. Cancers, heart disease and strokes accounts for almost 50 percent of deaths on the islands. There are 4 general hospitals and 17 health centers positioned throughout the islands. There is also a home for the infirm and elderly and a psychiatric facility on Nevis. The islands lay in the Carribean hurricane belt, and several hospital facilities have been damaged by repeated strikes, leading to the rebuilding of the J N France Hospital in the capital city of Basseterre. Saint Kitts and Nevis are part of the regional drug service and is well-supplied with medicines on its national drug formulary. See Also: Healthcare, South America; Pregnancy. BIBLIOGRAPHY. Pan American Health Organization,
Health in the Americas, 2002 (Pan American Health Organization, 2002); World Health Organization, The World Health Report 2006: Working Together for Health (World Health Report) (World Health Organization, 2006).
Heather K. Michon Independent Scholar
Saint Lucia Saint Lucia is an island nation in the Windward chain of the Carribean Sea, north of Saint Vincent and the
Saint Lucia, a tropical paradise, is relatively free of communicable diseases, with few cases of malaria, yellow fever, and dengue.
Grenadines. Colonized by the British around 1663, the small volcanic island changed hands between the British and the French 14 times between the 1660s and 1814. Independent since 1979, Saint Lucia remains a Commonwealth Realm with Queen Elizabeth II as the official head of state. The economy has long been dominated by banana exports, but the government has been trying to expand into new sectors over the past decade, particularly in the areas of tourism and offshore banking. The population of Saint Lucia is 170,650 and growing at 1.3 percent annually. This growth is the result of a robust birth rate and low death rate; many Saint Lucians are leaving the island for better opportunities elsewhere. Life expectancy at birth is currently 70 years for males and 78 years for females. Infant mortality is low at 12 deaths per 1000 live births; among children aged 1 to 5 years, the rate is 14 deaths per 1000 live births. Saint Lucia is relatively free of communicable diseases, with few if any reported cases of malaria, yellow fever and dengue fever in recent years. There is a mild outbreak of diarrhea infections every couple of years, but with 98 percent of the country using safe water sources and 89 percent using sanitary facilities, these are fairly limited in scope. The country’s immunization rate has risen to about 95 percent for common childhood diseases. The island has been poliofree since 1970.
Saint Vincent and the Grenadines
The major causes of morbidity and mortality on Saint Lucia are accidents, cardiovascular diseases, cancers and diabetes. In a 1990-95 survey, researchers found the 85 percent of all births take place outside of marriage and 40 percent of island households are headed by single women. Contraceptive use among women is estimated at 47 percent. UNICEF put antenatal care coverage at 48 percent, but 99 percent of all births take place with the help of skilled attendants. Maternal mortality is rare. Saint Lucia has both public and private healthcare providers, managed under the island’s Ministry of Health. Both offer a mix of both curative and preventative medical services. See Also: Healthcare, South America; Pregnancy. BIBLIOGRAPHY. Pan American Health Organization, Health in the Americas, 2002 (Pan American Health Organization, 2002); World Health Organization, The World Health Report 2006: Working Together for Health (World Health Report) (World Health Organization, 2006).
Heather K. Michon Independent Scholar
Saint Vincent and the Grenadines Saint Vincent and the Grenadines is an island nation in the Windward chain of the Caribbean Sea, between Grenada and Saint Lucia. Total land area of the islands is 389 kms with Saint Vincent accounting for 344 kms; the other 45 kms is spread over 31 tiny islands and cays. Native Caribs resisted colonization on the island chain until 1719. The British won control by 1769 and held the island as a colony until 1979. It continues as a member of the Commonwealth Realm. Similar to nearby Saint Lucia, Saint Vincent’s economy has been dominated by banana exports for decades, and is now attempting to diversify into tourism and offshore banking. The population of the islands is estimated at just over 118,000, growing at a rate of 0.25 percent annually. Many Saint Vincentians choose to leave the is-
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lands in search of opportunities elsewhere, giving the nation a net migration rate of minus 7.58 per 1000. The birth rate is 16.02 births per 1,000 population, and the death rate 5.97 per 1,000 population. The median age is 27.4. Life expectancy at birth is 72.21 years for males and 76.04 years for females. About 60 percent of the population lives in urban areas. The burden of communicable disease on the islands has shown a marked decrease over the past decade. Dengue fever and leptospirosis made a comeback in the mid-1990s, due in part to an increase in rodent infestation and improper disposal of human waste in some regions. Health officials have made significant inroads in controlling both these problems in recent years. Most Saint Vincentians now have access to safe drinking water and sanitary waste facilities. Non-communicable diseases are the main cause of morbidity and mortality on the islands. There are no good figures on the prevalence of diabetes, hypertension and other common ailments, but records from 1995 show that in a sample group of about 5,800 people registered with local health officials, 61.2 percent had hypertension, 21.8 percent had diabetes, and 17 percent had both. Cancer is another leading cause of death, primarily cancers of the digestive tract or peritoneum. Health officials launched a serious effort to improve healthcare among children in the mid-1990s, including more and improved local clinics, educational programs for parents and caregivers, and immunization drives. Immunization rates are now near 100 percent. Rates of malnutrition have dropped. Infant mortality is 17 deaths per 1,000 live births, with under-five mortality at 20 deaths per 1,000 population. Women’s health has also improved in recent years. Cervical cancer screenings are available to all. At least 60 percent of women have access to birth control. Pregnant women are prompted to have six prenatal and three post-natal checkups, and over 80 percent attend all nine examinations. All women have trained attendants monitoring childbirth, and the maternal mortality rate is very low. The country reports 101 physicians and 276 nurses working on the islands in 2007. Per capita expenditures by the government on healthcare is estimated at $210 per person. See Also: Cancer (General); Women’s Health (General).
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Salivary Gland Disorders
BIBLIOGRAPHY. Central Intelligence Agency, “Saint Vin-
cent and the Grenedines,” CIA World FactBook, www. cia.gov/library/publications/the-world-factbook/geos/ vc.html (cited June 2007); Pan American Health Organization, “Saint Vincent and the Grenadines,” Health in the Americas (v.2, 1998); United Nations Children’s Fund, “UNICEF At a glance: Saint Vincent and the Grenadines Statistics,” www.unicef.org/infobycountry/stvincentgrenadines_statistics.html (accessed June 2007); World Health Organization, “WHO: A guide to statistical information at WHO,” www.who.int/ (cited June 2007). Heather K. Michon Independent Scholar
Salivary Gland Disorders Salivary gland disorders encompass a broad range of conditions that can affect these supportive glands of the digestive tract. The salivary glands function is to manufacture and release saliva, which moistens and starts the digestive breakdown of ingested food. Saliva is a complex mixture of water and many different types of chemicals, which have diverse functions in addition to initiating digestion. Some of the functions of saliva are: anti-bacterial; anti-viral; anti-fungal; tissue protective; lubricating; re-mineralizing; digestion;
Sjögren’s syndrome causes inflammation of the salivary glands and a deterioration of mucous membranes of the mouth and gum lining.
and buffering. With this many needed biologic effects of saliva, it is not hard to imagine why disorders of the salivary glands can cause a multiplicity of problems. Disorders of the salivary glands will discussed in reference to four general areas: salivary stones (sialolithiasis); tumors (cancer and non-cancerous); autoimmune (the immune system attacking and destroying the salivary glands); and infections. There are three major salivary glands and many unnamed minor salivary glands. One of the major glands, the parotid gland, lies superficial to the angles of the jaws (mandibles) and drains saliva into the mouth through the Stensen’s duct which opens in the mouth on each side at the level of the second upper molar. The submandibular glands are located under the jaw and drain saliva into the mouth through Wharton’s duct to an opening near the frenulum of the tongue (tissue attachment on the undersurface of the tongue). The sublingual glands are also under the tongue and drain either into Wharton’s duct or directly into the mouth. The flow of saliva is controlled by many factors including food (stimulates a watery copious flow), emotions (fear stimulates a very thick saliva), and overall hydration status of the individual. One autoimmune condition, called Sjögren’s syndrome, causes inflammation of the salivary glands which results in decreased flow of saliva (and tears) and can cause a deterioration of the mucous membranes of the mouth and gum lining. Excessive dryness of the tissues makes them more susceptible to injury, delayed healing, infection, and in the case of the mouth tooth loss due to decay and gum disease. Treatment of Sjögren’s syndrome is directed at preventing tissue damage (use of intra-oral artificial saliva and artificial tears) and systemic medications (anti-malarials, cortisone derivatives, and anti-cancer drugs) similar to the treatment for other autoimmune connective tissue diseases (lupus, systemic sclerosis, etc.). Persons suffering from Sjögren’s syndrome have a much higher incidence of developing cancer of the lymph glands (lymphoma). Salivary gland stones (sialolithiasis) can form in the glands, with 90 percent arising in the submandibular gland, as many as 20 percent in the parotid gland and only 1-2 percent in the sublingual glands. Men develop salivary stones more often than women and the peak incidence of occurrence is between the ages of 30 and 60 years. There are several contributing factors to the development of salivary stones, such as dehy-
Salmonella Infections
dration, trauma, inflammation, and anti-cholinergic drugs (medications which slow the flow of saliva and cause a thickened consistency). Calcium is the major component of these stones. A person with salivary stones usually presents with an intermittent swelling of the respective gland, which becomes worse with eating because stimulation of saliva and a blocked duct causes retrograde accumulation of the saliva and a swollen gland, which slowly drains or is reabsorbed. This stagnation of flow can cause an infection. A special x-ray (sialogram) can be taken after injecting radiographic dye into the suspected duct and can show the obstruction. Treatment of salivary stones sometimes requires surgery to remove the stone and a recommendation to increase the intake of water to prevent recurrence. Salivary gland tumors can be either non-cancerous or cancerous. Typically, the smaller the salivary gland, the more likely the tumor is to be cancer. For instance, the smaller, unnamed salivary glands give rise to 80 percent of the cancerous tumors of the salivary glands while the parotid glands offer up 70 percent to 85 percent of the non-cancerous tumors. Diagnosis of the palpable lump is made by obtaining a piece of the tumor surgically or through a fine needle biopsy. Unlike other head and neck tumors, smoking and excessive alcohol intake have not been associated with cancerous tumors of the salivary glands but these habits are clearly not considered to be healthy choices overall. The treatment of salivary tumors, benign or cancerous, includes primarily surgical removal of the entire tumor if possible. In the case of the parotid gland, this involves careful dissection around the facial nerve so that there will not be facial paralysis. Sometimes this is unavoidable if the tumor involves the facial nerve. In the case of malignant tumors, both radiation therapy and chemotherapy might be used for treatment. Infections of the salivary glands include both bacterial and viral. The most well known viral infection of the parotid is mumps, caused by Paramyxovirus (single-stranded RNA). Wide scale immunization of children with a series of 2 MMR (measles, mumps, rubella) injections has decreased the incidence significantly, with only rare outbreaks occurring instead of the expected endemic outbreak every spring. In the United States in 1968 there were 152,209 cases and in 1993 there were 1,692, indicating the validity of the decision to immunize against this disease, which can
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attack the testicles and cause severe atrophy (wasting away) of the male gonads (testicles). Bacterial infections of the salivary glands can occur and most likely occur due to the Staphylococcus aureus bacteria (in community acquired) and sometimes Streptococcus and Haemophilus bacteria. Swelling of the glands and pus draining from the duct openings makes the diagnosis. Surgical drainage and intravenous antibiotics (amoxicillin-clavulanate or clindamycin) are required. While we do not often think about the function and importance of salivary glands, their vitally important functions are quickly noticed if salivary disorders occur. See Also: Digestive Diseases (General); Mumps; Sjogren’s
Syndrome.
BIBLIOGRAPHY. Mary A. Albrecht, “Epidemiology, Clinical Manifestations, and Diagnosis of Mumps,” www.uptodate.com (cited August 2006); Jose Dutra, et al., “Salivary Tumors,” www.uptodate.com (cited August 2006); Sara B. Fazio, and Daniel G. Deschler, FACS, “Salivary Gland Stones,” www.uptodate.com (cited August 2006); Robert Fox, M.D., et al., “Clinical manifestations of Sjögren’s syndrome,” www.uptodate.com (cited August 2006); Arnold S. Freedman, and Nancy Lee Harris, M.D., “Clinical and pathologic features of diffuse large B cell lymphoma,” www. uptodate.com (cited August 2006); Arnold S. Freedman, and Nancy Lee Harris, “Clinical and pathologic features of the marginal zone Lymphomas,” www.uptodate.com (cited August 2006); Dennis E. Lopatin, Ph.D., “Chemical Composition and Functions of Saliva,” www.umich.edu (cited August 2006).
Richard K. Ogden, D.O., FACOFP, FAAFP Kansas City University of Medicine and Biosciences
Salmonella Infections Salmonella infection or salmonellosis is one of the most common bacterial infections worldwide. The salmonella germ is actually a group of bacteria that can cause diarrheal illness in humans, with more than 95 percent of cases of salmonella infection being
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Samoa
foodborne. It is responsible for a variety of clinical syndromes, including enterocolitis, bacteremia, enteric fever (usually caused by typhoid or paratyphoid species), and severe local infections. Animal feces are usually the source of contamination, and humans consuming contaminated foods are the targets of the disease. Contaminated foods are often animal in origin, such as beef, poultry, milk, or eggs. However, all foods, including vegetables, can become contaminated.� Most persons infected with salmonella develop diarrhea, fever, and abdominal cramps 12 to 72 hours after infection. The illness usually lasts four to seven days, and the disease is self-limited. However, in some, complication may arise, as severe diarrhea may be the cause of hospitalization to remove dehydration. Dissemination of the disease to the blood stream results in bacteremia and is eventually lethal unless the person is treated promptly with antibiotics. The elderly, infants, and those with impaired immune systems are more likely to have a severe illness and should, therefore, receive particular attention. Salmonella infection is responsible for 600 deaths in the United States each year. Specific lab tests are necessary to identify salmonella in the stools of an infected person. Clinical diagnosis is fairly accurate, so lab test are not frequently requested. However, further testing can determine its specific type and which antibiotics could be used to treat it. Contaminated foods usually look and smell normal. Many raw foods of animal origin are frequently contaminated, but fortunately, thorough cooking kills salmonella. Food may also become contaminated by the unwashed hands of an infected food handler, who neglected hand hygiene after using the bathroom. People who have salmonellosis should not prepare food or pour water for others until they have been shown to no longer be carrying the salmonella bacterium. Salmonella may also be found in the feces of some pets, especially those with diarrhea, and people can become infected if they do not wash their hands after contact with these animals’ feces. Because foods of animal origin may be contaminated with salmonella, consumption of raw or undercooked foods poses a serious risk of illness. Crosscontamination of foods can be avoided by keeping uncooked meats separate from produce, cooked foods, and ready-to-eat foods. A thorough wash of hands, cutting boards, counters, knives, and other utensils is
a good technique to be implemented while handling uncooked foods. On a broader scale, governments and organizations have been developing and implementing solutions that provide good protection against salmonella: pasteurization of milk and treating municipal water supplies are highly effective prevention measures that have been in place for many years. On the other hand, regulations demanding improvements in farm animal hygiene, in slaughter plant practices, and in vegetable and fruit harvesting and packing operations may help prevent salmonellosis caused by contaminated foods. Better education of food industry workers in basic food safety and restaurant inspection procedures have also prevented cross-contamination and other food handling errors that can lead to outbreaks. Wider use of pasteurized egg in restaurants, hospitals, and nursing homes is an important prevention measure. In the future, irradiation or other treatments may greatly reduce contamination of raw meat. SEE ALSO: Food and Agriculture Organization of the United Nations (FAO); Food Contamination/Poisoning; Food Safety; Foodborne Diseases. BIBLIOGRAPHY. E. Braunwald, et al., eds., Harrison’s Principles of Internal Medicine, 15th ed. (McGraw-Hill, 2001); “������������������������������������������������������� Salmonellosis,” Centers for Disease Control and Prevention, www.cdc.gov/ncidod/dbmd/diseaseinfo/salmonellosis_ g.htm (cited April 2007);������������������������������������� “Salmonella ������������������������������������ Infection,” E-Medicine, www.emedicine.com/emerg/topic515.htm (cited April 2007).
Ricardo Mexia Independent Scholar
Samoa Samoa is a tropical island nation in the southern Pacific Ocean, about halfway between Hawaii and New Zealand. Two large islands, Upola and Savai’I, comprise 96 percent of the total landmass, with eight small islets providing the remaining 4 percent. The total area of 2,944 square kilometers is comparable in size to the state of Rhode Island. All the islands are volcanic in origin, although there have been few eruptions over the past three centuries. Total population on the islands is 176,900. The growth rate is minus 0.2 percent annually, with a
San Marino
migration rate of minus 11.76 per 1,000 people. Only 22 percent live in urban areas. The economy depends on agriculture (particularly coconuts), fishing, tourism, manufacturing, and remittances, as more and more working-age Samoans look for a better life beyond the islands. The population has become more heavily weighted toward the young, with 39 percent under the age of 14. Life expectancy at birth is now 68 years for males and 74 years for females. Mortality rates for children are low, with 24 deaths per 1,000 for infants younger than 1, and 29 deaths per 1,000 for those between the ages of 1 and 5. There have been significant improvements in the prevention and treatment of infectious diseases. All Samoans have access to sanitation, and 88 percent use clean water sources. Immunization programs have virtually eradicated polio, tetanus, and diphtheria. The government is now trying to end lymphatic filariasis. Typhoid and dengue fever remain endemic in some areas, and there are an average of 33 new tuberculosis cases diagnosed each year. Like most of the Pacific region, human immunodeficiency virus (HIV)/AIDS is almost nonexistent, with only 12 cases verified since 1990. However, a survey in one region found that 38 percent of women who visited prenatal clinics had at least one sexually transmitted disease. Combined with the modest tuberculosis rate, Samoa has a potential for a major HIV outbreak. Health officials are working to improve surveillance and education programs. “Lifestyle” diseases are a major problem on Samoa. Obesity affects 57 percent of the population, with 67 percent of women and 48 percent of men falling into the obese range. The diabetes rate is 23 percent, double what it was in 1990. More than 21 percent of the population suffers from high blood pressure. The actual number of cases is unknown because it is generally believed that for every one confirmed diagnosis of diabetes, there are three more that are undiagnosed, and most people on the islands do not seek screening for either diabetes or high blood pressure. These problems are being seen in younger and younger people, and are beginning to strain the resources of the Samoan medical community. Surveys clearly illustrate the source of these problems. Forty percent of the population smoke tobacco. Twenty-one percent say they have little or no daily physical activity. Thirty-eight percent say they rare-
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ly eat fresh fruit. Thirty-eight percent drink excessive amounts of alcohol. The Ministry of Health has launched a variety of programs to try to improve the general health of the population. The Samoan medical system is small, with 50 physicians, 136 nurses, 37 midwives, and around 200 working as auxiliary and support staff. There are two general hospitals, 6 district hospitals, 19 primary care centers, and one private hospital on the islands. SEE ALSO: Healthcare, Asia and Oceania; Sexually Transmitted Diseases; Smoking. BIBLIOGRAPHY. Douglass Drozdow-St. Christian, Elusive
Fragments: Making Power, Propriety & Health in Samoa (Carolina Academic Press, 2002); Pan American Health Organization, Health in the Americas, 2002 (Pan American Health Organization, 2002); World Health Organization, The World Health Report 2006: Working Together for Health (World Health Report) (World Health Organization, 2006). Heather K. Michon Independent Scholar
San Marino San Marino is a small independent nation located in the Apennine Mountains of southern Europe. Only 60.5 kms (23.4 kms) in size, it is the smallest nation in Europe after Vatican City and Monaco, and completely surrounded by Italy. Once among the poorest regions in Europe, San Marino is now a popular tourist area, playing host to millions of visitors each year. Per capita income is over $34,000 annually. The population is estimated at 29,600 and growing at 1.22 percent annually. The birth rate and the death rate are almost equal, with 9.89 births per 1,000 population and 8.27 deaths per 1,000 population, and the total fertility rate is 1.39 children born per woman. Population increases are driven primarily by migration, with 10.57 migrants per 1,000 citizens. Sixty-six percent of Sammarinese are between the ages of 15 and 64; the median age is 40.9 years. San Marino has some of the highest life expectancies in Europe, at around 77 years for males and 86 years for females.
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Sao Tome and Principe
San Marino is largely free of major communicable disease. There were no deaths from infectious disease reported between 1995-2000. Clean water and sanitation is on par with other European nations. Most of the population lives well above the poverty line, and there is little, if any, food insecurity. HIV/AIDS has not emerged as a problem within the country. Noncommunicable diseases accounted for 85 percent of all reported deaths in the period between 1995-2000, with accidents or other external causes accounting for another five percent. Forty-eight percent of deaths were caused by circulatory disorders, and 31 percent from cancers. Major risk factors for disease are based on lifestyle. High tobacco use and high blood pressure among men increases their risk for disease; while for women, high blood pressure and high body mass index are the primary underlying cause of poor health. The healthcare system in San Marino is well funded. The country spends an estimated $3356 per capita, or about 7.4 percent of its gross domestic product, on health. All citizens are entitled to free, comprehensive medical care. The healthcare establishment is expected to undergo some pressure in coming years, as the population continues to age and develop the chronic problems of the elderly. See Also: Birth Rate; Healthcare, Europe. BIBLIOGRAPHY. United Nations Children’s Fund, “UNI-
CEF—At a glance: San Marino—Statistics,” www.unicef. org/infobycountry/sanmarino_statistics.html (cited June 2007); World Health Organization, “Highlights On Health In San Marino,” Highlights On Health In San Marino, www. euro.who.int/document/e88392.pdf (cited June 2007); World Health Organization, “A guide to statistical information at WHO,” WHO: A guide to statistical information at WHO, www.who.int/whosis/en/ (cited June 2007). Heather K. Michon Independent Scholar
Sao Tome and Principe Sao Tome and Principe is an island nation in the Gulf of Guinea, about 225 km (140 mi) off the western coast of Africa. With the two islands contributing a
total area of 1001 kilometers (622 miles) the former Portuguese colony is the smallest independent nation in Africa. Agriculture has always been the backbone of the island economy, first sugar and now in cocoa production. Most of the population gets by on subsistence agriculture and fishing, with 54 percent of Sao Tomeans living below the poverty line. The discovery of offshore oil fields between the islands and Guinea has brought the promise of increased revenue in coming years. The population of the islands is estimated at 199,560, growing at 3.13 percent annually. Growth is driven primarily by a high birth rate of 39.72 births per 1,000 population, as compared with a death rate of 6.28 deaths per 1,000 population and a net migration rate of minus 2.14 migrants per 1,000. The total fertility rate is 5.53 children per Sao Tomean woman. Median age on the islands is 16.2 years. Current life expectancy at birth is 66.03 years for males and 69.30 years for females. The risk of communicable diseases, particularly water-borne illnesses, is high throughout Sao Tome and Principe. About 80 percent of islanders have access to safe drinking water, but only 25 percent have access to sanitary waste facilities. In some areas, less than 10 percent of the population has toilet facilities of any kind. Cases of bacterial diarrhea, typhoid fever, and hepatitis A are common. In 2005, international aid workers rushed to contain a cholera outbreak that threatened 80 percent of the population. Malaria is also an ongoing problem for islanders. HIV/AIDS has not emerged as a major epidemic, although there have been a few diagnosed cases. The government currently offers universal access to antiretroviral drugs (ARVs) to those Sao Tomeans afflicted with the virus. Noncommunicable diseases play a significant role in the morbidity and mortality of Sao Tomeans. Cancer, heart disease, and diabetes are among the leading causes of hospital admissions, and this is expected to increase as the population ages. Children’s health suffers from poor sanitation and malnutrition. Infant mortality rates are estimated by UNICEF at 75 death per 1,000 for babies under the age of one, and 118 deaths per 1,000 for children between the ages of one and five. About 20 percent of infants show low birth weight. For children under 5, 13 percent are underweight, 29 percent show signs of stunted growth, and 4 percent suffer from wasting. Malaria and diarrhea are the main culprits in childhood illness and death.
Sarcoidosis
Sao Tome and Principe invests an estimated 11.5 percent of their gross domestic product in health care. This works out to about $48 per capita. There are about 80 doctors, 260 nurses, 50 midwives and 10 dentists working on the islands, with a medical staff of 760 laboratory technicians, pharmacists, and community health workers. There are 32 hospital beds per 10,000 people. See Also: Healthcare, Africa, Infectious Diseases (Gen-
eral).
Bibliography. Central Intelligence Agency, CIA World
Factbook. www.cia.gov/library/publications/the-worldfactbook/geos/tp.html (cited June 2007); United Nation’s Children’s Fund, “Containing a Cholera Outbreak,” www. unicef.org/infobycountry/stp_26773.html (cited June 2007); World Health Organization, “County Health System Fact Sheet: Sao Tome and Principe,” www.afro.who.int/ home/countries/fact_sheets/saotomeprincipe.pdf (cited June 2007). Heather K. Michon Independent Scholar
Sarcoidosis Sarcoidosis is a multisystem disease of unknown etiology which has a worldwide occurrence, with certain groups at higher risk. In the United States, African Americans are at increased risk compared to Caucasians, while northern Europeans are at higher risk to develop sarcoidosis than are Mediterranean Europeans. Clustering within families has been observed, suggesting that relatives of patients with sarcoidosis are at increased risk of developing sarcoidosis. Despite the fact that the cause of sarcoidosis is unknown, a number of hypotheses have been formulated including (1) infection, (2) overexaggerated immune response following exposure to an environmental agent, and (3) autoimmune reaction (where the host’s tissues attack themselves). Presentation The typical presentation of sarcoidosis is variable and many patients are diagnosed following performance
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of a chest X-ray for an unrelated purpose (e.g., when undergoing a routine physical examination). Thirty to 60 percent of those diagnosed incidentally will remain asymptomatic and undergo spontaneous recovery without any treatment. The most common clinical presentation of sarcoidosis involves cough and shortness of breath with or without chest pain. Many patients complain of nonspecific symptoms such as fatigue, muscle weakness, joint aches, weight loss, inability to exercise due to breathing problems, or localized symptoms such as painful nodules on the shins or skin lesions. Eye involvement, Bell’s palsy, or parotid gland swelling has also been described in sarcoidosis. Diagnosis When sarcoidosis is suspected, a chest X-ray should be performed because approximately 90 percent will have lung involvement. Because of the large number of other diseases that can be confused with sarcoidosis, including infections and malignancy, a biopsy of affected tissue is routinely performed before the diagnosis of sarcoidosis is secured. A biopsy is obtained by removing an enlarged lymph node, obtaining a skin biopsy (abnormal areas), or via a technique called bronchoscopy. When isolated organ involvement involves the liver or heart, biopsies of those organs must be considered. Bronchoscopy is particularly useful because the lungs are frequently involved by sarcoidosis. This procedure is performed by a pulmonologist and can be done as an outpatient. The patient is typically given “conscious sedation,” which refers to administration of intravenous sedation to a patient while maintaining the patient’s ability to breathe for him- or herself. Following topical sedation with lidocaine (similar to what a dentist uses), a flexible bronchoscope (a tube the approximate diameter of a pencil eraser with a light and camera on the tip) is passed through the nose or mouth to the voice box, down between the vocal cords into the main breathing tube. Biopsies of irregular areas and washings of the breathing tubes are obtained with very rare complication. These biopsies (up to 2–3 mm in size) are sent to the laboratory. The tissue is examined under the microscope for noncaseating granulomas (the classic feature of sarcoidosis) and stains and
1520 Satellite DNA cultures for tuberculosis and fungi are performed. Because sarcoidosis can be confused with other conditions, the diagnosis is only rendered after cultures for tuberculosis and fungi are determined to be negative and when there is no evidence of another diagnosis. Treatment Because asymptomatic patients will frequently undergo spontaneous remission, no therapy may be required. Specific indications for systemic corticosteroid therapy (oral or intravenous prednisone with continued therapy for 6 to 12 months) include the following: moderate or severe lung involvement, involvement of the central nervous system (brain or spinal cord), heart, eye (vision threatening), severely elevated levels of blood calcium, markedly elevated liver function tests, or pulmonary hypertension. These patients should receive systemic (oral) corticosteroids and consideration should be given to the addition of other therapies. Examples of therapies additive to corticosteroids include cyclophosphamide or azathioprine (chemotherapy drugs), antimalarial drugs, and thalidomide; the use of such agents should be monitored by specialists familiar with their usage. Those with severe incapacitating fatigue may respond to prednisone at low doses for short periods (two to three months) and those who have either stable disease or only mild symptoms should be considered for topical steroid therapy (e.g., for skin lesions) or treatment with nonsteroidal antiinflammatory therapies (e.g., ibuprofen, naproxen). Patients who receive high-dose, long-term corticosteroids should be evaluated for the prevention of osteoporosis. While treatment is in progress, careful evaluation of the patient is routine, including repeated measurements of lung function, performance of chest X-rays, evaluation of abnormalities noted during the diagnostic workup, and monitoring for adverse effects of therapy. Patients with end-stage sarcoidosis unresponsive to all forms of therapy should be referred to a lung transplant center for consultation regarding the appropriateness of the patient for lung transplantation. Prognosis The majority of patients who are diagnosed incidentally with sarcoidosis will undergo spontaneous re-
mission without therapy. Patients with only skin or lymph node involvement and those who lack involvement of major organs have the best prognosis. Although death may occur in up to 5 percent of patients with sarcoidosis, the majority of patients with indications for systemic therapy with steroids will respond to treatment. SEE ALSO: Bell’s Palsy; Infectious Diseases (General). BIBLIOGRAPHY. J. A. Wiegand and M. H. Brutsche, “Sar-
coidosis Is a Multisystem Disorder with Variable Prognosis—Information for Treating Physicians,” Swiss Medical Weekly (v.136, 2006). Sandra K. Willsie, D.O. Kansas City University
Satellite DNA The study of satellite DNA consists of research into highly repetitive DNA—sequences that tend to reoccur at high frequencies with the nucleotides adenine and thymine. This means that they generally have lower densities and can form a second “satellite” band when the demonic DNA is separated along a density gradient. Altogether, satellite DNA, together with minisatellite and microsatellite DNA, constitute the tandem repeats—the latter usually found in transcription units, and these are thought to originate from a slippage of the replicated chromosome against its template. Often, the base pair repetition will stop proper protein synthesis and this can lead to problems such as myotonic dystrophy. Although this usually appears in adults, it can also occur in children, with a weakening of the muscles in the face, neck, forearms, hands, and lower legs, sometimes with the formation of cataracts in eyes and mental retardation, although many people can survive beyond middle age with the disorder. The initial research on satellite DNA was at the University of Edinburgh, Scotland, with biochemist Dr. Chris Tyler-Smith’s work at the University of Oxford in the late 1980s adding much to our knowledge. Dr. Tyler-Smith became fascinated by the ability to use DNA to show relationships of people and
Saturated Fats
later became famous for using his work in his work The Genetic Legacy of the Mongols in which he traced the DNA of an individual who was living during the 1000s ce, in the Mongol empire in the DNA of about 16 million people, when the average person alive then would have about 20 descendants sharing that person’s DNA today. SEE ALSO: Base Pair; DNA. BIBLIOGRAPHY. James Allan, “Comparative Studies on
the Satellite DNA of Related Rodent Species,” PhD thesis (University of Edinburgh, 1974); Thengiz Beridze, Satellite DNA (Springer, 1986); Paul Andrew Biro, “Sequence Analysis of Mouse Satellite DNA,” PhD thesis (University of Edinburgh, 1976); Graham George Pearson, “Distribution and Properties of Nuclear Satellite DNA,” PhD thesis (University of Edinburgh, 1975). Justin Corfield Geelong Grammar School, Australia
Saturated Fats The words oils, fats, and lipids are all terms used to refer to foods that should be considered fats. Fatty compounds can be chemically saturated or unsaturated. All fats consist of fatty acids (chains of carbon and hydrogen atoms, with an oxygen atom at one end and occasionally other molecules) bonded to a backbone structure, often glycerol (a “backbone” of carbon, hydrogen, and oxygen). Fats as a class of food are the source for essential fatty acids (nutrients that our body needs but cannot produce and are taken in by eating). Fats bind to lipid soluble vitamins (A, D, E, and K), making them accessible for our bodies’ needs through fat cells that store and release energy. Fat is the most concentrated source of energy in foods, and when kept at reasonable levels in our diet, are not unhealthy. Fats become unhealthy for us when they are excessively eaten, leading to an increase in lipid levels in our body and the consequent deposition of these lipids in our vasculature. Saturated fats and trans fats are considered the unhealthy fats. Saturated fats are fully hydrogenated,
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meaning that there is a hydrogen on every carbon and the molecule is very stable (are usually solid at room temperature) and hard to break up. This allows them to store and ultimately provide more energy than carbohydrates or proteins—9kcal for every gram of fat—and makes them more likely to stick to the body as cholesterol. Foods that contain a high proportion of saturated fat are butter, tallow, lard, coconut oil, cottonseed oil and palm kernel oil; dairy products (especially cream and cheese); meat; as well as foods meant to be stored for long periods of time. Many Third World countries depend on these staples as daily meals. Trans fats are a type of unsaturated fats, where double bonds between carbons in the backbone “kink” the chain. They are usually made from saturated fats. The kinking of the fat molecule makes it easier for them to stick together, leading to cardiovascular problems when eaten in excess. Trans fats allow the foods containing them to last longer, so are used in products that have longer shelf lives (i.e., fast foods, snack foods). They are also found in meat. Excess consumed fats are an important cause of dyslipidemia and cardiovascular disease such as atherosclerosis. There is clear evidence from randomized controlled trials that significant improvements in blood lipid parameters can be achieved by modifying dietary fat intake, and for some time, there has been a consensus that reduced consumption of saturated fat should be a goal for the populations of many higher-income countries. For lower-income countries, the goal should be to limit the amount of fats in the diet—whether indigenous or other—to no more than 30 percent of daily calories. SEE ALSO: Cholesterol; Heart Diseases (General); Heart
Diseases—Prevention.
BIBLIOGRAPHY. N. Bilenko, et al., “Mediterranean Diet and Cardiovascular Diseases in an Israeli Population,” Preventive Medicine (v.40, 2005); J. B. German and C. J. Dillard, “Saturated Fats: What Dietary Intake?” American Journal of Clinical Nutrition (v. 80, 2004).
Caroline Sebley, OMS2 Kansas City University of Medicine Tyler Cymet, D.O. Johns Hopkins School of Medicine
1522 Saudi Arabia
Saudi Arabia The Kingdom of Saudi Arabia was formed after the defeat of the Ottoman Empire in World War I. Initially the region which became Saudi Arabia was formed into the Kingdoms of Nejd and Hejaz, and the Kingdom of Saudi Arabia proclaimed on January 8, 1926. Twelve years later the discovery of oil resulted in the country becoming extremely wealthy. Saudi Arabia has a population of 27,020,000 (2006), including 5,576,000 foreigners (2006), and has 166 doctors and 330 nurses per 100,000 people. Currently about 11 percent of the public expenditure in the country is spent on health care. Little is known about medical care during medieval times, although it is known that the Iraqi-born surgeon, Avicenna (980–1037), did work in Arabia, writing his Canon of Medicine. Healthcare remained extremely limited with the Health Department being established in 1926 by King Abdulaziz al-Saud. In 1946 there were only 300 hospital beds in the entire country, which had a population of 5 million. However, in 1950, the government massively enlarged the healthcare services in the country, building hospitals at Riyadh, the capital, and also Mecca, Jeddah and three other cities. By this time there were 111 doctors and 1,000 hospital beds in the country. To run this enlarged medical service, in 1951 the National Ministry of Health was established, and in 1966 the Saudi Red Crescent Society was founded. The oil wealth only started to make the country wealthy from the 1960s, and in 1970, the Saudi government established its first Five Year Plan. This led to an increase in the numbers of primary health centers in the country, more public sector hospitals, and encouragement for private sector hospitals. This gradually led to Saudi Arabia having one of the best healthcare systems in the world, with free medical care for all its citizens, and also any foreign Muslims who visit Saudi Arabia for the hajj. In 1975 the King Faisal Specialist Hospital and Medical center in Riyadh was opened. Until the 1970s, Saudi doctors were trained overseas, especially in Egypt, the United States and Britain, and there was clearly need for locally-trained doctors, and in 1976 the first class of physicians graduated from King Saud University which had been founded
as Riyadh University, changing its name in 1982. At the same time a Residency program was established at King Abdulaziz University Hospital in Jeddah. Three years later the first renal transplant in Saudi Arabia took place, and in 1992, the home healthcare agency at the King Faisal Specialist Hospital in Riyadh was established. The Saudi Medical Bibliography has been published from 1983, covering publications from 1887 until the present day. The College of Medicine at King Saud University in Riyadh, remains the center for much of the medical research carried out in the country, and there are now many specialist hospitals in Riyadh, Mecca, Jeddah and other cities. The King Fahd Medical City outside Riyadh was built in the 1990s at the cost of $534 million, and there are also medical facilities around the country run by various government agencies including the National Guard, the Ministry of the Interior, and the Ministry of Defense and Aviation. Mention should also be made of the Jeddah Health Institute and other similar institutes in Riyadh and Hofouf which provide basic medical training for healthcare professionals. The medical problems being treated in Saudi Arabia are many, but with increasing hygiene throughout the 20th century, and better diet, there are more problems associated with western countries, such as cancer and obesity. However there have also been important studies into other medical conditions. While malaria is found in western parts of Saudi Arabia on occasions, there have been no cases in the middle region of the country, and it remains scarce in the northern region. SEE ALSO: Healthcare, Asia and Oceania. BIBLIOGRAPHY. El Sayed El-Bushra, “The distribution of population and medical facilities in Saudi Arabia,” Erkunde (v.34/3, 1980); E.B. Gallagher and C.M. Searle, “Health Services and Political Culture of Saudi Arabia,” Social Science and Medicine (v.21, no.3, 1985); G.B.S. Mujahid, “Development of Saudi Arabia’s Health Sector 1384-1394,” Journal of College of Administrative Sciences (University of Riyadh, no. 6, 1978); Andrew C. Twaddle, Health Care Reform around the World (Auburn House, 2002).
Justin Corfield Geelong Grammar School, Australia
Schizophrenia
Schistosomiasis Schistosomiasis, also known as Bilharzia, is a parasitic disease caused by flatworms and is widely found throughout the tropics. Following malaria, it is the most common parasitic disease in the world. The world health organization estimates that over 200 million people world wide are infected with the parasite and that of these, 120 million have clinical disease and approximately 20 million have severe disease. Schistosomiasis is caused by five species of flatworms in the genus Schistosoma. The natural life cycle of the schistomoma parasite consist of a sexual stage in the human host and an asexual stage in a fresh water snail host. Schistosomes in contaminated water can penetrate the skin of individuals who are using the water to wade, bathe, swim, or clean. Once inside the human host, the schistosomes reach the blood vessels and travel to the portal veins where they mature and begin to produce eggs. Clinical symptoms of schistosomiasis are caused by the immune response to the parasite’s eggs rather than to the worms themselves. While approximately half of all eggs migrate through the bowel or bladder wall and are excreted in the feces or urine, half remain in the body and generate a granulomatous immune response. Early symptoms, within one to two months of infection, are non-specific and may include fatigue, muscle soreness, rash, itchy skin, fever, and chills. Eggs that are not shed return to the portal circulation and can ultimately reach the lungs, heart, central nervous system eyes, and muscle. Severe schistosomiasis is clinically variable depending on the location of egg deposition and may include pulmonary fibrosis, splenomegaly, central nervous system disease, and increased risk of bladder and liver cancer. While most schistosomiasis infections cause chronic disease, acute severe disease can have high levels of morbidity. Schistosomiasis may be diagnosed through the identification of eggs in the feces or urine. Blood serology tests and tissue biopsy of bowel, bladder, liver, or muscle may also aid in diagnosis. Various imaging modalities including ultrasound and CT scan may be useful in identifying chronic disease. Treatment of schistosomiasis aims to cure disease, decrease morbidity, and reduce transmission in endemic areas. Praziquantel is the drug of choice for all species of schistosomiasis. Treatment for a single day
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will cure approximately 85 percent of infected individuals and significantly decrease the number of eggs in those who are not completely cured. Future public health interventions aimed at decreasing the overall burden of disease in endemic areas include the development of an effective vaccine and control of the fresh water snail host. SEE ALSO: Parasitic Diseases; Public Health. BIBLIOGRAPHY. Centers for Disease Control, “Schistosomiasis”, www.cdc.gov/NCIDOD/DPD/parasites/schistosomiasis/default.htm (cited September 2006); World Health Organization, “Schistosomiasis”, www.who.int/topics/ schistosomiasis/en/ (cited September 2006).
Shaun K. Morris, M.D., M.P.H. Independent Scholar
Schizophrenia Schizophrenia is a brain disorder affecting approximately 1 percent of the world’s population. Schizophrenia has a number of behavioral manifestations, but among the most common are hallucinations, delusions, and deficits in cognitive and social function. These experiences are often frightening and may accompany withdrawal, paranoia, or extreme frustration observed in someone who suffers from schizophrenia. In addition, people with schizophrenia may have disorganized speech and behavior, such that they may not make sense when they speak or may speak in fragments. The illness affects men and women in equal ratios and occurs at a similar rate in all ethnic groups. Psychotic symptoms (such as hallucinations and delusions) usually emerge in men during their late teens and early 20s and in women during their mid-20s to early 30s. Schizophrenia seldom occurs after age 50 and only rarely before puberty, although cases of schizophrenia in children as young as 5 have been reported. During the adolescent years, the first signs of schizophrenia can include social withdrawal, a drop in grades, sleep disturbances, and irritability. Many people who develop schizophrenia have difficulty caring for themselves;
1524 Schizophrenia therefore, the reliance and subsequent stress on immediate family members is significant. The symptoms of schizophrenia have been classified into three categories: positive, negative, and cognitive symptoms. Positive symptoms involve unusual thoughts, hallucinations, delusions, and disorders of thought, behavior, and movement. Hallucinations are most commonly auditory, with patients often hearing voices telling them what to think, how to behave, or how to react. Another positive symptom, delusions, are defined as false and irrational personal beliefs, such as believing that people in outer space are sending special messages to them. They may also have delusions of grandeur where they believe they are famous historical or religious figures. The second category, negative symptoms, manifest as a loss or decreased ability to express emotion, initiate plans, speak, or find pleasure in day-to-day activities. These traits are often challenging to isolate from symptoms of depression, serving to delay proper diagnosis at times. People experiencing these symptoms may neglect basic hygiene and need help with everyday activities that once were second nature.
For adolescents, the first signs of schizophrenia can include social withdrawal, a drop in grades, sleep disturbances, and irritability.
The final category, cognitive symptoms, includes problems with attention, memory, and the executive functions driving advanced planning and organization. Cognitive impairments often interfere with the patient’s ability to lead a normal life: maintaining a job, home, friends, and significant other. This deficit can indeed cause a great deal of emotional distress. Overall, positive symptoms are the easiest to diagnose and respond well to medication, whereas negative and cognitive symptoms are often much more insidious. The underlying etiology of schizophrenia is unclear, although researchers understand that both genetics and environmental influence play a significant role. Schizophrenia is thought to have a strong hereditary component, as first-degree relatives (i.e., parent or sibling) of a patient have a 10 percent chance of developing schizophrenia themselves. The rates of schizophrenia in people with second-degree relatives (i.e., aunts, uncles, grandparents, or cousins) are also higher than that of the general population. Twin studies have contributed to the study of inheritance as well, finding that the identical twin of a person with schizophrenia has a 40 to 65 percent chance of developing the disorder. Ongoing linkage and association studies have now identified a number of polymorphisms that confer risk. All in all, available evidence suggests a major contribution of genetics to schizophrenia susceptibility, although there are clearly environmental influences as well. Many environmental factors have been suggested as risk factors, such as exposure to viruses, malnutrition during fetal development, complications during birth, and stressful environmental conditions. Schizophrenia is now widely conceptualized as a disorder of brain development in which both genetic predisposition and environmental insult play a critical role. Thus far, considering the etiology of the disease is unclear, treatment is largely symptomatic. The most utilized treatment regimen involves use of antipsychotic medications. Antipsychotic medications have been marketed since the mid-1950s and are most effective at alleviating the positive symptoms of schizophrenia through their actions on the dopaminergic neurotransmitter system. Individuals respond differently to antipsychotic medication, which means that a variety of drugs and dosages must often be tried before the most effective regimen is found. The over-
School Nutrition Association (SNA)
all goal is to find medication that offers the greatest symptom relief with the fewest side effects. The first generation of antipsychotics, also known as “typical antipsychotics, includes chlorpromazine (Thorazine®), haloperidol (Haldol®), perphenazine (Etrafon®, Trilafon®), and fluphenzine (Prolixin®). These medications have a tendency to cause extrapyramidal side effects such as rigidity, muscle spasms, and tremor, which may persist even after the medication is withdrawn. To combat such severe side effects, new drugs have been developed in the last two decades. These medications are referred to as atypical antipsychotics, and may have fewer side effects than the older medications, although the overall efficacy remains equivalent. The most prescribed drugs of this class are clozapine (Clozaril®), risperidone (Risperdal®), olanzapine (Zyprexa®), and quetiapine (Seroquel®). While schizophrenia cannot be cured at this point in time, the combination of proper medication, a strong social network, and a dedicated psychiatrist may permit a patient to live a full and rewarding life. SEE ALSO: Neurologic Diseases (General); Psychiatry. BIBLIOGRAPHY. Lynn E. DeLisi, 100 Questions and Answers
about Schizophrenia: Painful Minds (Jones and Bartlett, 2006); Human Genome Project, www.ornl.gov/sci/techresources/ Human_Genome/project/about.shtml; International HapMap Project, www.hapmap.org; National Institute of Mental Health, “What Is Schizophrenia?” www.nimh.nih.gov/ publicat/schizoph.cfm#definition (cited April 2007). Misty C. Richards Albany Medical College
School Nutrition Association (SNA) The School Nutrition Association (SNA), formerly called the American School Food Service Association, is a national nonprofit organization that provides students with nutritional meals. The agency sets standards for school-based meals; provides legislators with nutritional information upon which the government can set regulations; and serves as the spokesperson for children’s nutritional needs.
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SNA was formed in 1946 after President Harry Truman signed the National School Lunch Program (NSLP) into law, with the federal government paying states 9 cents per meal for reimbursement. Legislation for this law was written in response to the high numbers of men rejected for military service in World War II because of diet-related health issues and was called a “measure of national security.” Within one year, half a billion meals had been fed to 7.1 million children; in 1958, reimbursement dropped to 4 cents per meal because of increasing numbers of participants. SNA founded the Child Nutrition Foundation in 1964; this organization raises funds to fulfill SNA initiatives and to provide educational funding for people wishing to obtain professional certifications in nutrition. In 1966, President Lyndon B. Johnson signed the Child Nutrition Act, which established the School Breakfast Program (SBP). This Act mandates free or low-cost breakfasts in schools, both public and private, and in child care agencies. The philosophy behind this Act was that quality nutrition is necessary for learning. That year, 3 billion meals were fed to 19 million children. That Act also mandated the Special Milk Program (SMP), which provides affordable or free milk to children in schools and child care programs that do not participate in other federally funded nutrition programs. SNA created a three-year pilot program called the Summer Food Service Program (SFSP) to feed children healthy meals when school was out of session. Grants were provided to states and a prime target audience was the child care facility. In 1975, two programs were created from the SFSP: the Child Care Food Program and the SFSP. Entities eligible to run one of these programs include public or private schools; governmental units; nonprofit agencies or camps; and public or private universities. In 1968, the Child Care Food Program expanded to become the Child and Adult Care Food Program (CACFP) wherein homeless shelters and adult day care centers may apply to participate in the program. In 1969, President Richard Nixon added free and reduced-in-price lunches as another component of the hunger programs; the legislation aimed to prevent discrimination in qualifying and to provide privacy to program participants. In 1971, 3.8 billion meals were given to 24.5 million children; in the neediest areas, the federal government began paying 100 percent of the breakfast
1526 Schweitzer, Albert program costs. Numbers of meals served exceeded 4 billion in 1976, serving 26 million children. In 1993, it was determined that the majority of school lunches contained too much fat; the following year, the U.S. Department of Agriculture (USDA) began the Healthy School Meals Initiative. In 1996, the 50th anniversary of the program, nearly 4.3 billion meals were served to just fewer than 40 million students. SEE ALSO: Nutrition; Nutritionist. BIBLIOGRAPHY. School Nutrition Association, www.
schoolnutrition.org (cited April 2007); Lorri A. Zipperer, ed., The Health Care Almanac: A Resource Guide to the Medical Field (American Medical Association, 1995). Kelly Boyer Sagert Independent Scholar
Schweitzer, Albert (1875–1965) Albert Schweitzer was an Alsatian born physician, theologian, musician, and philosopher. Winner of the 1952 Nobel Peace Prize, his contributions to global health stemmed largely from his time in Lambaréné in French Equitorial Africa, now Gabon, where he started a hospital to serve the local African population. Schweitzer received his doctorate in philosophy in 1899 from the University of Strasbourg and received his licentiate in theology in 1900. He completed his medical studies in 1913, also at the University of Strasbourg. Schweitzer in part funded his education, and later his hospital, with proceeds earned as an internationally known organist. Schweitzer first arrived in Africa in 1913 and set up his hospital in the village of Lambaréné. In 1917, during the First World War, as Germans in a French colony, Schweitzer and his wife were sent to an internment camp in France. Released in 1918, Schweitzer spent the next six years traveling throughout Europe giving lectures, concerts, and writing. In 1924, Schweitzer returned to Lambaréné and spent the majority of the rest of his life there. By the 1960’s, the hospital Lambaréné had grown to the point that is could provide medical and surgi-
cal care for up to 500 patients at a time. Schweitzer wrote important books related to all of his fields of work. His most well known published works regarding his medical practice and experiences in Africa include On the Edge of the Primeval Forrest and More from the Primeval Forrest, his account of his work in Lambaréné, and his autobiography Out of My Life and Thought. In his later life, Schweitzer worked tirelessly along side Albert Einstein and others in the effort to limit the expansion and use of nuclear weapons. He received many awards and honors including the Goethe Prize of Frankfurt, numerous honorary university doctorates, and culminating in the 1952 Nobel Peace Prize. Schweitzer used the prize money from the Nobel Prize to build a leprosarium at Lambaréné. After retiring as a practicing physician, Schweitzer continued to oversee his hospital until his death on September 4, 1965 at the age of 90. He was buried along side his wife in Lambaréné. SEE ALSO: Gabon; Healthcare, Africa. BIBLIOGRAPHY. Albert Schweitzer, On the Edge of the
Primeval Forest (The MacMillan Company, 1922). Albert Schweitzer. More from the Edge of the Primeval Forest (The MacMillan Company, 1931). Albert Schweitzer, Out of My Life and Thought (Henry Holt, 1949). Shaun K. Morris, MD, MPH Independent Scholar
Scleroderma Scleroderma, which is literally defined as “hard skin,” is an uncommon, chronic condition that produces thickening of the skin through an atypical growth of connective tissue. In more extensive and progressive cases, blood vessels and internal organs such as the lungs, esophagus, or intestines, may also be affected. Affected skin may appear erythematous (red) and firm to the touch. In addition, painful ulcers on the fingers or toes, joint pain/stiffness, and hair loss in affected areas may be seen. Important factors that help determine the severity of scleroderma include the total area affected by the disease, as well as the degree of involvement of the blood vessels and inter-
nal organs. While scleroderma can affect any age, race, or gender, occurrence within demographics may be seen. For example, localized scleroderma is more often found in people of European descent, whereas generalized scleroderma is more common in people of AfricanAmerican descent. Generalized scleroderma is more likely to affect female adults (usually between the ages of 30–50). In the United States, approximately 300,000 individuals are affected by scleroderma. Localized Scleroderma Localized scleroderma is designated, when only the skin is affected. The two types of localized scleroderma are called morphea and linear. The morphea-type scleroderma is characterized by thick, oval-shaped plaques with a bluish-purple rim. Ablation or reduction of the hair follicle with resultant reduced hair growth and diminished sweating is characteristic. This type of localized scleroderma has been found more commonly in people aged 20–40. Linear scleroderma, on the other hand, may be seen as bands of hardened skin. In the case that it occurs on the head, it is termed en coup de sabre. Notably, this subtype is more prevalent in children and teenagers. Generalized Scleroderma Generalized scleroderma is another subtype of scleroderma in which multiple parts of the body are affected. Generalized scleroderma also has two different types: diffuse (DcSSc) and limited (LcSSc). Both forms of systemic sclerosis are known to affect internal organs and blood vessels as well as the skin. Almost 90 percent of these patients have gastrointestinal (GI) involvement, even though half of them might not even realize it. Common GI symptoms include difficulty swallowing, cough after swallowing, feelings of choking, heartburn, constipation or diarrhea, and these mainly stem from chronic gastroesophageal reflux. DcSSc is known to be the most severe type and thus the most life threatening, because of its rapid onset and extensive influence on the skin and internal organs. LcSSc, however, has a better prognosis, as the affects on the skin and internal organs are less severe in extent and character. The onset tends to be slower onset. Causes Scleroderma occurs primarily from the overproduction of a connective tissue protein called collagen. While the exact reason has yet to be determined,
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it is known that the immune system plays a role in the excess production of the collagen by activated fibroblasts (cells responsible for collagen production). The increase in collagen leads to thick bands forming (fibrosis) in the skin and around internal organs. Because these fibrotic bands are nonpliable, they may restrict the function of the involved tissue. Some researchers theorize that hormones such as estrogen play a significant role because this condition is much more common in women between 30 and 55 years of age. Diagnosis There are two important factors in discerning the diagnosis of scleroderma: clinical presentation and laboratory analysis. In addition to the hardening of the skin, clinical signs may be apparent. For example, a nonspecific sign that may be observed is Raynaud’s phenomenon (RP). RP is described as a change in skin color in the digits (fingers and toes) upon exposure to cold temperature, due to the contraction of blood vessels (ischemia). The fingertips often turn pale or white in cold temperature, and blue when lacking oxygen, a condition called cyanosis. If this condition persists, the lack of oxygen to these areas can elicit pain and ulcer formation. Additional signs of scleroderma may be calcinosis cutis (painful calcium deposition under the skin) or digestive impairment. Laboratory analysis is a vital component in the diagnosis which includes a biopsy of the involved skin and serologies for relevant antibodies, such as anticentromere or antitopoisomerase-1. Therapy There is no known cure for any of the forms of scleroderma. However, depending on the severity of the disease in each individual case, treatments are available to manage the symptoms of the disease, such as antiinflammatory agents (such as celecoxib, prednisone, and the antibiotic minocycline) for joint pain or inflammation. Steroid-sparing immunosuppressants (such as cyclosporine or azathioprine) have also been used effectively to moderate the disease. Physicians may also recommend certain lifestyle changes, such as smoking cessation and changes in eating habits. In addition, physical therapy may be needed to maintain functionality, especially when the limbs are involved. SEE ALSO: Immunosuppresion; Skin Diseases (General).
1528 Scoliosis BIBLIOGRAPHY. Mayo Clinic, “Scleroderma,” Mayo Clinic,
www.mayoclinic.com/health/scleroderma/DS00362 (cited July 2006); National Institute of Arthritis and Musculoskeletal and Skin Diseases, “Handout on Health: Scleroderma,” www.niams.nih.gov/hi/topics/scleroderma/scleroderma. htm (cited July 2006); Scleroderma Research Foundation, “Awareness and Outreach,” www.srfcure.org/srf/awareness. htm (cited July, 2006); John Varga, “Overview of the Clinical Manifestations of Systemic Sclerosis (Scleroderma) in Adults,” www.uptodate.com (cited July 2006). Shalu S. Patel Rajiv I. Nijhawan University of Michigan
Scoliosis Scoliosis is a skeletal defect characterized by abnormal curvature of the spinal column away from the midline. Neuromuscular disease and congenital malformations can cause scoliosis, but most cases are idiopathic, or without a known cause. Cases often present in adolescence and are more common in females. Congenital scoliosis is a birth defect related to problems in formation of the vertebrae during development. Cases progress rapidly and may be associated with malformations in other organs, such as the heart and kidneys. Neuromuscular scoliosis arises from muscle weakness or paralysis from underlying diseases, such as cerebral palsy and muscular dystrophy. Scoliosis in adults may also be caused by degenerative joint conditions, such as spine arthritis. These causes are rare, however; 80 percent of scoliosis cases are idiopathic. The condition runs in families, but researchers are still searching for the genes responsible for idiopathic scoliosis. The primary risk factor for a worsening scoliotic curvature is growth, so adolescents are most commonly affected. A larger angle of spinal curvature, especially in the upper spine, also portends a higher risk of progression. Symptoms and Diagnosis Physical examination reveals apparent anatomical asymmetries in scoliosis. Patients may lean to one side and may have uneven shoulders or hips. Ribs may project farther on one side, and one shoulder blade
may be more prominent than the other. Patients can experience back pain and fatigue after prolonged sitting, and some have breathing difficulties. Given that scoliosis develops gradually and is often painless, early detection is essential. Many schools now offer scoliosis screening, and physicians identify scoliotic children using physical examination and family history information. X-rays can help assess severity using the angle, shape, and location of curvature. Nerve impingement pain can be evaluated using magnetic resonance imaging (MRI). Most scoliosis cases do not progress, but patients should be monitored with clinical examination and X-rays every three to six months for worsening of the spinal curvature. Complications Long-term complications of scoliosis include spinal cord or nerve damage, chronic back pain, and arthritis. In severe cases, injury to the heart and lungs can cause breathing difficulty, respiratory infections, and heart compromise. The physical deformity often affects children psychologically, so physicians should look for signs of depression. Treatment Treatment of scoliosis is based on the angle of spinal curvature, age, and other risk factors. Most children with scoliosis have curvatures less than 20 degrees and require no treatment. Children with 25 to 40 degrees of spinal curvature typically receive braces to prevent further scoliotic progression. Several types of braces are available, from low-profile underarm devices that fit around the ribs to the full-torso Milwaukee brace for upper spine scoliosis. These devices are useful for idiopathic cases and are typically not used for congenital or neuromuscular scoliosis. A surgery known as spinal fusion is recommended if the spinal curvature reaches greater than 40 degrees. Vertebrae are permanently connected together with pieces of bone graft and supported with metal rods, screws, and wires. Such procedures can correct up to 50 percent of the deformity; however, they can be associated with several surgical complications, such as infection and arthritis. It is also important to help adolescents cope with the psychosocial obstacles associated with physical deformity. Children should be involved in supportive peer groups and confidence building activities.
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SEE ALSO: National Institute of Arthritis and Musculosk-
eletal and Skin Diseases (NIAMS); Neuromuscular Disorders; Orthopedist; Osteogenesis Imperfecta; Pediatrics. BIBLIOGRAPHY. John Lonstein, “Scoliosis: Surgical versus
Nonsurgical Treatment,” Clinical Orthopaedic Related Research (v.443, 2006); Scoliosis World, www.scoliosis-world. com (cited November 2006). Anjan P. Kaushik, B.S. Francis H. Shen, M.D. University of Virginia Dino Samartzis, D.Sc., M.Sc., Dip. EBHC Harvard University and Erasmus University Caused by excess electrical discharge in the brain (scan above), seizures are most prevalent in the very old and very young.
Seizures A seizure is a sudden, involuntary attack in which body function, movement, sensation, awareness, behavior, or movement is altered. It is caused by excess electrical discharge in the brain. Epilepsy is a related condition in which patients are susceptible to seizures. Ten percent of Americans experience at least one seizure, and 3 percent will have epilepsy diagnosed by age 80. The prevalence of epilepsy in the United States is 2.7 million. Seizures impact all age groups, but are most prevalent in the very old and very young. They also exert a burden on society in the form of medical expenses, forgone wages, and productivity. This burden due to epilepsy alone amounts to $15.5 billion annually. Signs and Symptoms A typical seizure lasts between 30 seconds and 2 minutes. They are classified into two major categories: partial and generalized onset. Generalized onset seizures begin with an electrical disturbance in a large region of the brain, whereas partial onset seizures begin in a smaller area. Although partial seizures begin in one small area, they can spread into a larger region of the brain. This is called secondary generalization. A grand mal, or tonic clonic, seizure is one example of a generalized seizure. The person becomes rigid, has muscle jerks, and may have a number of other symptoms. Some generalized seizures, on the other hand, are not even noticeable to onlookers. A petit
mal, or absence seizure, for example, often presents as rapid blinking or staring into space. This is often just written off as daydreaming. Someone with a simple partial seizure has symptoms depending on the location of the excess electrical discharge, the focus. These people can have a change in muscle activity, alterations in taste or smell, feelings of intense anxiety or fear, or a number of other symptoms. Following the seizure, people experience headache, amnesia for the event, fatigue, and muscle aches. In epilepsy, an aura may precede the seizure. An aura is a set of symptoms that warn of an upcoming seizure. Common examples include the feeling of déjà-vu, numbness in one side of the body, and hallucinations such as imagining strange sights, smells or sounds. An aura is not present in all epileptic seizures. Status epilepticus is continuous seizure activity for 30 minutes, or two or more sequential seizures without full recovery of consciousness between the two. This is a true medical emergency. Diagnosis When someone first presents with a seizure, a physician will take a history and perform a physical exam. It can be difficult for a physician to differentiate a seizure from syncope, a loss of consciousness due to lack of oxygen to the brain. Therefore, a good history from the patient and a witness is the most
1530 Senegal important part of determining the etiology of a loss of consciousness. The physician may order an electrocardiogram (EKG), electroencephalogram (EEG), magnetic resonance imaging (MRI), or a computed tomography (CT) scan to further help determine the cause of the episode. The EKG and EEG test the electrical activity in the heart and brain, respectively. The MRI and CT scans are both tests that take pictures of the brain. Other medical conditions that can mimic seizures include stroke, cardiac arrhythmia, or panic attacks. Common causes of seizure in the United States include trauma, alcohol withdrawal, some medications, brain tumors, epilepsy, infections, and stroke. In many cases, the physical exam and tests are normal, leaving the etiology of the episode undetermined. Treatment The treatment of seizures depends on their cause. If the seizure was drug induced, the doctor may discontinue that medication. Psychiatric medications, Benadryl, and certain antibiotics have been associated with seizures. For seizures caused by infections in the nervous system, meningitis, the underlying infection should be treated. If the patient has had a seizure before, the doctor may consider epilepsy as a diagnosis. In this case, the patient would be advised to take epileptic precautions such as refraining from using heavy machinery. Once epilepsy is diagnosed, the doctor may also recommend drug therapy. Commonly used antiepileptic medications include Lamictal®, Trileptal®, and Dilantin®. Emergency Management If someone is having a seizure in front of you, • Protect the person’s head from injury. • Loosen tie, shirt, collar, or anything tight around the neck. • Turn the person to one side to keep the airway clear and prevent choking. • Do not try to restrain the person, unless he or she is in danger of causing personal harm (e.g., banging his or her head). • Call for emergency care if • Convulsive movements last longer than five minutes. • Breathing does not appear normal. • Another seizure starts..
SEE ALSO: Brain Diseases; Jackson, John Hughlins; National Institute for Neurologic Disorders and Stroke (NINDS); Neurologic Diseases Neurologist; Neurology. BIBLIOGRAPHY. Centers for Disease Control and Prevention, Epilepsy Home Page, www.cdc.gov/Epilepsy (cited July 2006); www.epilepsy.com.
Ross E. Breitbart Philadelphia College of Osteopathic Medicine
Senegal Senegal is located in western Africa, on the Atlantic coast south of the Senegal River. It is bordered by Mauritania to the north with Guinea and GuineaBissau to the south. The Gambia, a small independent nation, follows the track of the Gambia River from its outlet on the Atlantic for about 300 kilometers (186 miles) inland, surrounded by Senegal on all three sides. An attempt to unite with The Gambia failed in the late 1980s. Although Senegal has had troubles with both economic and political stability over the years, it remains one of the more peaceful countries in Africa. The population is 12,522,000 and growing at 2.65 percent annually. The birth rate is 37.4 per 1,000 and the death rate is 10.96 per 1,000. Median age is 18.7. Life expectancy is 55.34 years for males and 58.09 years for females. Gross national income is $710 per capita, with 22 percent living on less than $1 a day. The economy is marked by high rates of unemployment, with 48 percent of the overall population and 40 percent of urban youths out of work. Malaria is the chief cause of morbidity and mortality in Senegal, with 500,000 cases and 5,000 deaths annually. Other communicable diseases include dengue fever, yellow fever, Crimean-Congo hemorrhagic fever, schistosomiasis, meningococcal meningitis, and cholera. Overall, 76 percent of Senegalese have access to safe water and 57 percent have sanitary waste disposal, although these figures drop sharply in rural areas. Some observers consider Senegal a rare AIDS success story for Africa. The adult prevalence rate is 0.9 percent, with about 61,000 Senegalese infected. The tuberculosis rate is similarly low, at 79 cases per
100,000. The population is 94 percent Muslim and carries conservative sexual ideals. Senegal has put in place stringent tests of the blood supply and monitors sex workers for AIDS and other sexually-tranmitted diseases. They also have strong educational campaigns that involve considerable community involvement. Senegal has high child mortality rates, stemming largely from the prevalence of malaria, diarrhea, and acute respiratory disease. The current mortality rate among infants younger than one is 77 deaths per 1,000; for children aged 1-5, the rate almost doubles, to 136 deaths per 1,000. Immunization rates range from 7585 percent. Despite widespread poverty, there are low rates of malnutrition and stunting. Women face significant health risks during their childbearing years. Fifty-three percent of Senegalese marry before the age of 18; the total fertility rate is five children per woman. Only 11 percent of women use contraception. The maternal mortality rate is among the highest in the world, at 1,200 deaths per 100,000 live births. Twenty percent of women undergo some form of female genital mutilation in adolescence. Education of girls is not a high priority, and only 28 percent of women are literate. There has been a troubling rise in HIV cases among women, as they are more vulnerable to infections by their husbands and have little voice to demand condom use or abstinence. Hospital facilities have improved in recent years, but remain concentrated in the capital city of Dakar, which is home to 22 percent of the population. The country has some of the lowest ratios of medical professionals to population, with seven physicians and 35 nurses per 100,000 people. Additionally, 75 percent of doctors and 43 percent of nurses work in Dakar. Consequently, many Senegalese rely on traditional healers. SEE ALSO: Healthcare, Africa; Malaria. Bibliography. “HEALTH-SENEGAL: The Number of
Women Living with HIV/AIDS On the Rise”. IPS Inter Press Service, http://ipsnews.net/interna.asp?idnews=14557 (cited June 2007); Senegal. CIA World Factbook, www.cia. gov/library/publications/the-world-factbook/geos/sg.html (cited June 2007); “Senegal - Statistics”. United Nations Children’s Fund, www.unicef.org/infobycountry/senegal_ statistics.html (cited June 2007); The Joint United Nations Programme on HIV/AIDS, “Senegal,” http://www.unaids.
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org/en/Regions_Countries/Countries/senegal.asp (cited June 2007); Research Africa, “Sub-Saharan Africa—Senegal,” researchafrica.rti.org/index.cfm?fuseaction=home. country_view&country_id=7 (cited June 2007). Heather K. Michon Independent Scholar
Serbia and Montenegro Serbia is a landlocked country on the Balkan Peninsula in southeastern Europe. It is one of the states to emerge from the disintegration of the former Yugoslavia in the 1990s. In 1992, the area proclaimed its independence as the Federal Republic of Yugoslavia (FRY), and was renamed Serbia and Montenegro when the war ended in 1995. In 2006, the union between Serbia and Montenegro was dissolved, and the two regions went forward as separate nations. Most recent medical data, however, looks at them as a single country. There is little current demographic data on the newly separated countries. The population of Serbia is 10,150,000 and the population of Montenegro is 685,000. Life expectancy is 72.49 years for males and 77.86 years for females. Infectious and parasitic disease was responsible for only 0.5 percent of deaths annually, or about six deaths per 100,000. The adult prevalence rate for HIV/AIDS is 0.2 percent, with an estimated 10,000 people infected with the virus. Sexually transmitted disease are low, with just 0.7 cases of syphilis per 100,000. The tuberculosis rate is twice that of the European Union, with 27 new cases per 100,000 people. The noncommunicable disease profile is common to the region: a high rate of cardiovascular disease and other maladies, driven by poor lifestyle habits. Fiftytwo percent of adult males smoke, as do 42 percent of females. Sixteen percent of children also smoke. Tobacco use is implicated in 360 of every 100,000 deaths. Obesity affects 21 percent of males and 18 percent of females. In Serbia, 42 percent of men and 54 percent of women are physically inactive. Alcohol consumption, while lower than Europe overall, is still significant at 6.8 litres per person per year. Cardiovascular disease causes 54 percent of all deaths and cancer 17 percent. About 1.3 percent of the population has diabetes.
1532 Severe Acute Respiratory Syndrome (SARS) Mental health problems are responsible for 20 percent of the total disease burden and 1 percent of mortality. This high rate of mental disorders reflects a society that endured years of wartime traumas. The suicide rate, 17 per 100,000 deaths, is similar to other Balkan states. Unintentional injuries and accidents is in line with European Union averages, causing 46 out of every 100,000 deaths. Road traffic injuries are very high at 739 per 100,000, compared to 297 per 100,000 in the rest of the EU. Even before the split, the health systems of Serbia and Montenegro were essentially separate. Serbia has 45 hospitals and 57 specialized inpatient facilities, while Montenegro has seven general hospitals and three specialized hospitals. A private health system is developing, but has not yet been integrated into the state structure and is largely unregulated. Insurance is compulsory, financed by payroll taxes and international aid, and managed by state-run insurance bureaus. There is currently a gap between funding levels and reimbursements, leaving patients to cover the difference with out-of-pocket payments. SEE ALSO: Healthcare, Europe; Mental Health. Bibliography. United Nations Children’s Fund, “Serbia
and Montenegro—Statistics,” www.unicef.org/infobycountry/serbia.html (cited July 2007); “Serbia and Montenegro.” Central Intelligence Agency, World Factbook, www.cia.gov/ library/publications/the-world-factbook/geos/rb.html(cited July 2007); “Serbia and Montenegro”. The Joint United Nations Programme on HIV/AIDS, www.unaids.org/en/Regions_Countries/Countries/serbia_and_montenegro.asp (cited July 2007); “Serbia and Montenegro: 10 Health Questions About the New EU Neighbors,” World Health Organization, www.euro.who.int/Document/E88202_Serbia.pdf (cited July 2007). Heather Michon Independent Scholar
Severe Acute Respiratory Syndrome (SARS) Severe Acute Respiratory Syndrome (SARS) is one example of what is referred to as a new and emerg-
ing disease—that is, a disease whose incidence has increased in the last two decades; one that is newly appearing; or a disease that is spreading to new geographic areas. Other examples include HIV/AIDS, West Nile virus, Huntavirus, Ebola, monkey pox, and E. coli O157:H7. SARS was the first global epidemic of an emerging infectious disease of the new century. Over 8,000 SARS cases were identified at various locations throughout the world from January to May 2003 with nearly 10 percent succumbing to this disease. Although this fatality rate was high in comparison to most common infectious diseases (e.g., the case fatality rate for normal stains of influenza is around 1 percent), it was lower than other more lethal and virulent diseases such as Ebola which has a fatality rate between 70 and 90 percent. The causative agent of SARS was discovered to be a member of the coronavirus family whose other members cause a substantial fraction of the common colds experienced by humans. The SARS coronavirus damages the aveoli causing the lungs to be filled with a mixture of blood and dead cells and prohibiting the exchange of respiratory gases. SARS originally involved a zoonotic transmission in which the novel coronavirus crossed over from an animal species to humans, then adapting itself so that it could be transmitted between human hosts themselves. The palm civet cat is suspected to be the animal host reservoir for SARS. Because this animal is captured and sold for human consumption in southern China, it is thought that the initial viral crossover to humans occurred in the live animal wet markets of this area. The first human cases of SARS were identified in November 2002, as workers and food handlers in the animal markets of Guangdong province became ill with a mysterious disease then classified as “atypical pneumonia.” In early February, outbreaks occurred in various boom towns in areas of southern China, but these were small and localized and did not garnish much attention. In February 2003, a larger number of cases of the mysterious respiratory illness surfaced in local hospitals in the larger city of Guangzhou, spreading conspicuously amongst hospital staff and close contacts of infected patients. One of those infected was an elderly physician who subsequently traveled to Hong Kong where he stayed at the Metropole Hotel. This index case was later classified as a “superspreader”— an individual who, unexplainably, exhibits enhanced
infectivity. From this index case, 11 other hotel guests became infected. Among these guests were those who continued their travels within Hong Kong and to other major cities such as Toronto, Singapore, and Hanoi. All of Vietnam’s 63 SARS cases, 238 cases in Singapore, and 136 cases in Toronto could be traced to this superspreading event. With the development of a formal case definition by the World Health Organization (WHO), local containment efforts proved to be successful. Such efforts involved traditional measures of contact tracing and quarantine where those infected were asked to list all of the people he or she had been in contact with in the previous three weeks. Through followup, it would then be determined if the contacts were infected. Those infected would be quarantined to break the chain of transmission. The international response to SARS was coordinated by the WHO’s global influenza surveillance network. The WHO also mobilized the Global Outbreak Alert and Response Network, a partner organization comprised of 115 national health services, academic institutions, technical institutions, and individuals, to pursue internationally driven collaborative work on SARS. Telecommunication networks facilitated collaborative research among 11 laboratories dispersed throughout the world. The establishment of a “virtual network” connected to a secure Web site and complemented by daily teleconferences, ultimately led to the landmark achievement of identifying the causative agent of SARS within just one month and delineating its genetic code soon thereafter (processes which usually take months or years under normal circumstances). The rapid spread of SARS across the globe—spreading to five countries within 24 hours and more than 30 countries on six continents within six months—has been attributed to the ease and speed of international air travel in today’s world. In this context, it should be noted that the incubation period of many infectious diseases (i.e., the period between exposure and symptom onset) is now less than the travel time between any two major urban centers of the world. Consequently, many infected travelers may inadvertently carry the disease to far off locations. The globalized nature of infectious disease spread (and response) has many implications and reverberations for the economic, social, and political domains.
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For example, the WHO travel advisories issued in April 2003 recommended the postponement of travel to SARS affected regions and this had significant economic repercussions for many sectors, but primarily the travel, hospitality, and retail industries. It has been estimated that the costs to the world economy due to SARS was close to $54 billion. At the macro level, new developments in international relations could also be identified, as the political world adjusts to conditions of globalized infectious disease spread. For example, the WHO, as a supranational organization, by issuing a travel advisory, broke with the tradition of noninterference with the ability of sovereign nations to conduct trade. Finally, SARS spread among the network of many of the largest and most influential cities of the world, cities that often host large diaspora communities. As was evident in Toronto, one of the most multicultural cities in the world, infectious disease may lead to social problems related to the stigmatization of certain ethnic and other marginalized groups. (The research for this contribution was supported by a standard research grant from the Social Sciences and Humanities Research Council of Canada.) SEE ALSO: Epidemic; Institute of Medicine (IOM); MED-
LINE; Public Health; Travel Medicine; Traveler’s Health; Viral Infections; Virology; World Health Organization (WHO).
BIBLIOGRAPHY. Thomas Abraham, Twenty-First Century
Plague (Johns Hopkins University Press, 2004); S. Harris Ali and Roger Keil, Networked Disease: Emerging Infections in the Global City (Blackwell, 2007); Institute of Medicine, Learning from SARS (National Academies Press, 2004). S. Harris Ali, Ph.D. York University
Sexually Transmitted Diseases Sexually transmitted diseases, often also referred to as sexually transmitted infections or venereal diseases, are infectious diseases that are primarily transmitted via vaginal, anal, or oral sex, or via other sexual contact. Pathogens infect via the mucous membranes of the penis, vagina, or mouth, which are generally more
1534 Sexually Transmitted Diseases porous than skin. Genital fluids and blood generally have greater pathogen content than saliva. Sexually transmitted diseases include genital herpes, the human papilloma virus (HPV), gonorrhea, chlamydia, syphilis, and the human immunodeficiency virus (HIV). While other pathogens, such as meningitis and hepatitis B, can be transmitted via sexual contact, these infections are not classified as sexually transmitted infections as sexual contact is not the primary route of transmission. Similarly, sexually transmitted pathogens can also often be transmitted via other routes that permit contact with infectious material, such as sharing needles that have contacted contaminated blood. Herpes and HPV can also be transmitted via skin-to-skin contact. Many sexually transmitted infections, including syphilis, gonorrhea, genital herpes, and HIV, can also be transmitted from mothers to infants during childbirth and breast-feeding. bacteria and viruses Sexually transmitted diseases are caused by a variety of bacterial and viral pathogens, and those infected can present with a range of symptoms. One of the most common sexually transmitted infections, chlamydia, is caused by the Chlamydia trachomatis bacteria and can cause painful urination, fever, unusual discharge or bleeding from the genitals, and abdominal pain. Chlamydia is often referred to as a “silent infection,” however, as up to half of males and threequarters of females who are infected do not exhibit symptoms and do not know they are infected. Among women who are asymptomatic, approximately half who are not treated will developed pelvic inflammatory disorder (PID), which can cause scarring in the fallopian tubes, uterus, and ovaries, and can cause serious complications including chronic pelvic pain and complications in pregnancy. Gonorrhea, another bacterial sexually transmitted infection, is caused by the Neisseria gonorrhoeae bacteria and can also result in pelvic inflammatory disorder, as well as infections of the urethra, cervix, uterus, epididymis, and testicles. Symptoms include painful urination and intercourse, discharge or bleeding from the genitals, cramps, vomiting, fever, and scrotal swelling. As with chlamydia, up to two-thirds of those infected with gonorrhea may be asymptomatic. These asymptomatic infections, which can lead
to other reproductive health problems, are an important reason why sexually active people should be routinely screened for sexually transmitted pathogens, even when they exhibit no symptoms. Syphilis is also a bacterial sexually transmitted disease, caused by the Treponema pallidum bacteria. Primary syphilis occurs 10 to 90 days following infection, and patients experience a single sore near the site of infection. Secondary syphilis occurs one to six months following infection, and is characterized by a skin rash on the trunk and extremities (including the palms of hands and soles of feet), fever, sore throat, headache, weight loss, and enlarged lymph nodes. Tertiary syphilis occurs 1 to 50 years following secondary syphilis, and is characterized by tumor-like growths on the skin, mucous membranes, skeleton, and elsewhere. If left untreated, tertiary syphilis can cause damage to the heart, brain, and nervous system, and can be fatal. Syphilis gained notoriety in the United States in the course of one of the most unethical medical experiments involving human subjects, the Tuskegee Syphilis Study, during which infected African-American men were left untreated in order to study the natural course of the disease, even though effective antibiotics had long been available. Viral sexually transmitted diseases include genital herpes, HPV, and HIV. There are more than 100 different strains of HPV, approximately 30 of which are commonly transmitted sexually, and which infect mucous membranes and skin, and can cause lesions also known as genital warts, although many of those infected exhibit no visible lesions. Certain strains of HPV, especially HPV 16 and 18, can cause cancer of the cervix, although a vaccine against these high-risk strains is now available. A screening test, known as the Pap smear, is also highly effective at identifying cancerous lesions, although mortality from cervical cancer is still high worldwide among women without access to Pap smears and treatment. herpes simplex virus Genital herpes is caused by the herpes simplex virus, which causes painful sores on skin and mucous membranes. The herpes simplex virus is also responsible for cold sores on or near the lips. Outbreaks of sores are generally preceded by itching, tingling, or irritation. Following infection, the virus lies dormant in the cell bodies of neurons, growing toward the skin
with the axon, and then falling back into the cell body following an outbreak. This disease cannot be cured, although antiviral medications can reduce the severity and length of active outbreaks. Herpes simplex infections acquired during childbirth in infants can cause brain damage, and thus pregnant women are often actively screened and treated in order to prevent transmission. hiv/aids Perhaps the most deadly of sexually transmitted infections, HIV is the pathogen ultimately responsible for causing the acquired immunodeficiency syndrome (AIDS), which causes the immune system to fail and usually results in death from secondary infections. While antiretroviral medications can reduce viral load and the clinical progression to AIDS, there is no cure or vaccine against HIV. Most infected individuals exhibit primary flu-like symptoms and a rash approximately one to six weeks following infection. Following a latency period of between one and 20 years, most infected individuals ultimately go on to exhibit symptoms of AIDS, including lowered T-cell counts, weight loss, and vulnerability to secondary infections such as pneumonia, oral infections, Kaposi’s sarcoma, and toxoplasmosis. Some individuals have been infected with HIV for several years but have not yet developed symptoms of AIDS. While HIV is not solely transmitted via sexual intercourse, sexual transmission of HIV is the primary means of viral transmission, especially in countries with high prevalence of infection, including most of sub-Saharan Africa. Sexually transmitted diseases are also caused by protozoa and parasites. Pubic lice Phthiris pubis, colloquially known as crabs, are parasitic lice that live on human hair, especially pubic hair, and are primarily transmitted via sexual contact. They can cause intense itching or rash. These parasites can also be transmitted via sharing infected clothing or bedding. Adult pubic lice can be killed using medicated topical shampoos, although pubic hair must also be removed or combed to remove eggs (nits) that can cause further outbreaks after hatching. Sheets or clothes worn by infected persons must also be sterilized or destroyed. The scabies mite Sarcoptes scabei can also be transmitted sexually, which can also cause intense itching and an allergic response.
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The single-celled protozoan Trichomonas vaginalis is also spread via sexual contact, usually infecting the urethra in men and the vagina in women. Symptoms generally occur five to 28 days following infection and can include vaginal discharge, painful urination, inflammation of the genital region, and abdominal pain. However, most infections in men and approximately 20 percent of those in women are asymptomatic. Antiprotozoal drugs can be used to cure the disease. Although not caused by the transmission of a specific pathogen, bacterial vaginosis (BV), a common reproductive tract infection among women of reproductive age, is also associated with sexual behavior. When the normal bacterial balance of the vagina is disrupted, often by sexual intercourse or through use of certain contraceptive methods (especially the in intrauterine device [IUD]), vaginosis can occur, leading to itching, pain, odor, or vaginal discharge. While BV often causes no harmful long-term symptoms, these infections can increase the transmission rates of sexually transmitted infections, including HIV, chlamydia, and gonorrhea, and is also associated with pelvic inflammatory disease and pregnancy complications, including delivering babies of lowered birth weight. Although symptoms often clear up spontaneously, women with BV can be treated effectively with common antibiotics. determining factors There are several epidemiological factors that help determine the prevalence of sexually transmitted diseases in a population. Bacterial infections, including chlamydia and gonorrhea, can be cured using antibiotics, but those infected do not always have access to antibiotics and physicians, nor do asymptomatic patients always realize that they are infected. Antibiotic-resistant strains of bacteria are also becoming more prevalent, especially when antibiotics are incorrectly prescribed or ingested. Transmission rates of most sexually transmitted infections are enhanced when individuals are coinfected with another sexually transmitted disease, especially when these individuals have open sores in the vaginal canal, on the penis, or on the mucous membranes of the mouth. Individuals are often more infectious at certain points in the course of disease than at others: for instance, those infected with genital herpes are only infectious when experiencing an active outbreak
1536 Sexually Transmitted Diseases characterized by genital ulcers, while those infected with HIV are generally most infectious shortly following initial infection, as well as when the disease has progressed to AIDS. For some diseases, including HIV, receptive vaginal or anal sex is associated with higher rates of disease transmission as the receptive partner is more likely to suffer a tear in a mucous membrane than the penetrative partner, allowing a pathogen to pass through the mucous membrane more easily. Male-to-female transmission is thus often much more physiologically efficient than femaleto-male transmission. Social factors also determine the prevalence and incidence levels of sexually transmitted infections in a population. Sexually transmitted infections are concentrated in young people, with up to 60 percent of all new infections occurring in those under the age of 25. Properties of sexual networks, defined as the patterns of sexual mixing between individuals, often influence transmission routes. Sex workers and other highly sexually active persons are often instrumental in passing pathogens between otherwise disparate segments of populations, and thus are often the targets of public health campaigns. Long-distance travel has helped spread infections far beyond local areas, and infection outbreaks often spread along migration and transportation routes. Gender inequality, marriages between adolescent women and older men, and sexual violence has been associated with increased transmission of HIV and other sexually transmitted infections in many population-based studies. Prevention of sexually transmitted diseases is often accomplished via public health campaigns that encourage “safer sex” practices, such as using male or female condoms, reducing overall numbers of sexual partners, remaining faithful in a mutually monogamous relationship, delaying sexual debut, and remaining abstinent. Other campaigns encourage individuals to get tested frequently for disease status, especially when beginning a new sexual relationship. Some controversy surrounds testing for incurable sexually transmitted diseases, such as HIV, where the only benefit to those getting tested is their ability to avoid passing on the disease to others. This controversy has lessened in recent years as new pharmaceuticals for treating genital herpes outbreaks and HIV, among others, have become available, giving individuals a greater incentive to get tested. Contact tracing,
whereby infected individuals inform all sexual contacts of their disease status, can also be effective in preventing localized disease outbreaks. In many countries, including the United States, accurate scientific information regarding the various risks of specific sexual practices and preventative measures is often difficult to access, particularly in schools, based on politics and customs surrounding sexual mores and practices, particularly for women, unmarried adolescents, homosexuality, and samegender sex acts. Unlike many medical illnesses, those infected are often blamed for their disease or for transmitting disease, due to the politics of sexuality, sexual behavior, and personal sexual freedom. Despite associating infections with a few often vilified groups such as sex workers, highly sexually active individuals and homosexuals, sexually transmitted diseases are among the most common infections in a population and affect people of all sexual orientations, ages, races, and ethnic backgrounds. The social stigma surrounding sexually transmitted infections discourages open discussion and accurate information, thus individuals are often unaware of their risk of disease or are uninformed regarding the need for or means of protection and testing. Ignorance of disease risk is only enhanced by the fact that many sexually transmitted infections are asymptomatic, and thus individuals who only examine themselves or their sexual partners for visible signs or symptoms of disease, rather than getting tested and discussing the results with their partners, will underestimate their risk of infection. Clinically, sexual health is often lumped together with reproductive health, with Pap smears for HPV detection in particular often being considered routine care for reproductive-age women. Detection and treatment of sexually transmitted diseases are, however, often hampered by unwillingness on the part of either patients or clinicians (or both) to discuss sexual behavior. For this and other reasons, many countries have initiated a system of sexually transmitted disease clinics apart from other primary healthcare facilities, where individuals can be tested and treated anonymously. SEE ALSO: AIDS; Herpes Simplex; Pregnancy. BIBLIOGRAPHY. H. Hunter Handsfield, Color Atlas and
Synopsis of Sexually Transmitted Diseases (McGraw-Hill Professional, 2000); Anita L. Nelson and Jo Ann Woodward,
Seychelles
eds., Sexually Transmitted Diseases: A Practical Guide for Primary Care (Current Clinical Practice) (Humana Press, 2007); Lawrence R. Stanberry and David I. Bernstein, eds., Sexually Transmitted Diseases: Vaccines, Prevention and Control (Academic Press, 2000); U.S. Department of Health And Human Serv, Sexually Transmitted Diseases Updated 2006 (International Medical Publishing, 2007). Annie Dude University of Chicago
Seychelles Seychelles is an archipelago in the Indian Ocean, north of Madagascar and about 1600 kilometers (994 miles) off the eastern coast of Africa. The republic consists of 158 islands with a total land area of 455 kilometers (283 miles). Long a disputed territory between the French and the British, Seychelles became an independent country in 1976 and had made significant strides in raising its small population above subsistence levels. The economy, based on tuna fishing and tourism, is subject to wide fluctuations, making sustained growth difficult. The Ministry of Health touts Seychelles as the safest African country, with no malaria, yellow fever, or other tropical diseases. All residents have clean water and sanitation. All but 1 percent of children are fully immunized. There is almost no measurable population of HIV/AIDS or tuberculosis. Epidemiological threats are monitored and dealt with. The biggest communicable health risk in recent years has been the arrival of chikungunya, a mosquito-borne disease that causes fever, flu-like aches and pains, nausea and vomiting, but is not fatal. About 2,000 cases were reported in 2005–06. Like most middle-income nations, the biggest threat to the health of Seychellois are lifestyle diseases. Heart disease, diabetes and strokes are responsible for 35 percent of island deaths. Another 18 percent die of cancer. About 30.8 percent of Seychellois men use tobacco daily and about 35.2 percent of women are overweight or obese. Child mortality is low. A quarter of deaths in children aged 5-15 are the result of traffic accident, and 50 percent are due to accidents within the home,
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including choking and accidental poisionings. For adolescents and young adults, aged 15-24, traffic accidents account for almost 21 percent of deaths, 11 percent from drowning, and 16 percent from suicide. Obesity and drug use is increasing in the adolescent population, and is the cause of great concern to health professionals. Seychelles has six hospitals, with a total of 413 beds. There are also 17 health centers, seven private clinics, and five dental clinics. There are 1.51 physicians and 7.93 nurses per 1,000 Seychellois. Per capita government expenditure on healthcare is $402.50. See Also: Healthcare, Asia and Oceania; Heart Disease;
Lung Cancer; Obesity.
BIBLIOGRAPHY. Central Intelligence Agency, CIA World
Fact Book, www.cia.gov/library/publications/the-worldfactbook/geos/se.html (cited June 2007); Republic of Seychelles, “Ministry of Health,” www.moh.gov.sc/index.html (cited June 2007); United Nations Children’s Fund, “Seychelles,” “Seychelles—Statistics”. www.unicef.org/infobycountry/seychelles_statistics.html#24 (cited June 2007); World Health Organization, “A guide to statistical information at WHO,” www.who.int/whosis/en/index.html (cited June 2007).
Heather K. Michon Independent Scholar
Some 18 percent of Seychelles citizens die of cancer. About 30.8 percent of Seychellois men use tobacco daily.
1538 Shingles (Herpes Zoster)
Shingles (Herpes Zoster) Shingles is another name for herpes zoster, an acute infection caused by reactivation of the varicella zoster virus (VZV). It is characterized by a painful skin rash with blister-like lesions which is usually localized to one side of the body, often the face or trunk. Shingles may also produce fever, headache, chills, swollen lymph nodes, joint or abdominal pain and impaired vision and hearing; very rarely serious complications may occur including pneumonia , blindness, hearing problems, paralysis, encephalitis and death. Shingles usually clears up without treatment in two to three weeks and usually does not recur. Medical treatments available include antivirals such as Acyclovir, corticosteroids such as prednisone to reduce inflammation, and pain and anti-itching medications for symptom relief. Shingles is caused by the same virus which causes chicken pox; because VZV remains in the nerve cells of the body after the chicken pox episode is over, anyone who has had chicken pox in the past may develop shingles. It is not known why the virus is reactivated in some people, it is more common in people who are immunosuppressed due to medical conditions such as AIDS or who are receiving immunosuppressive drugs, and in people age 50 and older. Consequences may also be more serious in older person: for instance half of shingles patients over age 60 have lingering neuralgia (nerve pain). There are about 300,000 to 600,000 cases of shingles annually in the United States, and about 12 percent of the cases have sequelae, the most common of which is postherpetic neuralgia. Incidence in the United States is 2.2 cases per 1000 person-years, with persons over age 75 age highest risk with 14.2 cases per 1000 person-years. Shingles occurs worldwide because its root cause, infection with VZV, also occurs worldwide. Shingles rates in developed countries may fall in the future: the introduction of varicella vaccines which offer protection against chicken pox are commonly administered in childhood in most industrialized countries, so that the rate of childhood chicken pox is much lower than previously. However, the effectiveness of this vaccine in preventing shingles is not known, because widespread use has occurred too recently to allow studies of older adults vaccinated as children. Studies with immunocompromised individuals indicate that childhood varicella vaccination seems to lessen the risk of
shingles, but further studies are needed to determine if this also holds true for the general public. A shingles vaccine, Zostavax, was licensed in 2006 by the Food and Drug Association for shingles prevention in persons age 60 and older; it does not treat the disease once it has developed. In clinical trials, it prevented shingles in about half of test subjects and prevented post-herpetic neuralgia in twothirds of the subjects, and was most effective for people 60-69 years of age, although it also conferred some protection on older individuals. The Advisory Committee on Immunization Practices recommends vaccination with a single dose of Zostavax for Americans aged 60 and over, with the exception of persons with active tuberculosis, a compromised immune system, or who are allergic to gelatin or the antibiotic neomycin. See Also: Chicken Pox; Childhood Immunization; Immunization/Vaccination; Skin Diseases. BIBLIOGRAPHY. J. Hormberger and K. Robertus, “Cost-
Effectiveness of a Vaccine to Prevent Herpes Zoster and Postherpetic Neuralgia in Older Adults,” Annals of Internal Medicine (v.145, 2006); National Library of Medicine, “Herpes Zoster,” in Medical Encyclopedia, www.nlm.nih. gov/medlineplus/ency/article/000858.htm (cited June 2007); M.N. Oxman, et al., “A Vaccine to Prevent Herpes Zoster and Postherpetic Neuralgia in Older Adults,” New England Journal of Medicine (v.352/22, 2005). Sarah Boslaugh BJC HealthCare, Saint Louis
Shoulder Injuries and Disorders The shoulder is a complex joint formed by the articulation of several bones surrounded by muscular attachments and ligaments to form what is the most versatile joint in the human skeleton. The complexity provides for outstanding range of motion but predisposes to injury. Mechanical stresses pose a risk for dislocation or fracture that may result in debilitating injury. Given the musculoskeletal and supporting structural relations a broad range of disorders
are possible. In general, the most common disorders plaguing the shoulder joint can be classified and further differentiated based on the rotator cuff origin of the disorder, bony fracture involvement, and/ or the arthritic components of the ailment. The shoulder joint is frequently injured in a wide variety of activities ranging from sport related to repetitive overuse in the work environment. The shoulder offers tremendous range of motion and functions as the most mobile joint in the human body partly as a result of the unique bony articulation and supporting soft tissue architecture unique to the shoulder joint. The drawback to this increased mobility is the lack of structural restriction on undesirable and potentially hazardous movements. The bony portion of the shoulder joint consists primarily of three structures, the collar bone (clavicle), the shoulder blade (scapula), and the upper arm (humerus). The term shoulder actually encompasses several less prominent articulations. The clavicle meets with the acromion process of the scapula to form the acromioclavicular joint (AC joint). A ball and socket joint is formed when the glenoid labrum (soft tissue lip around the periphery of the glenoid fossa of the scapula) contacts the head of the humerus (glenohumeral joint). The labrum is a key structural component that widens and deepens the articulation between the head of the humerus and the scapular head to create a unique dynamic between of stability and range of motion. The muscular support of the shoulder is equally complex with three major groups of muscles providing support to the bony structures. Four muscles comprise the rotator cuff that aid in mobility as well as stability. The largest muscles of the chest and back also contribute to shoulder stability and both heads of the biceps originate from the scapula. Dislocation The shoulder joint is the most frequently dislocated major joint in the body. Dislocation results when the shoulder is forced beyond the limit of its normal range and the communication between the humerus (ball) and glenoid of scapula (socket) are displaced. Major complications of dislocation include nerve damage that may result in motor and sensory impairment. Following a shoulder dislocation, an athlete for example, will try to hold the injured ex-
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tremity to the side, gripping the injured arm at the forearm with the opposite hand. Should the injury be significant enough to damage the major nerve supply to the region, denervation of the deltoid muscle will result as well as loss of sensation of the proximal lateral aspect of the arm. Rotator Cuff The rotator cuff represents the upper half of the joint capsule of the shoulder joint reinforced by the tendons of insertion of the supraspinatus, infraspinatus, teres minor, and subscapularis muscles. Injury to the rotator cuff, a frequent cause of shoulder pain and disability, has a high incidence during athletic activities. Injury to the rotator cuff may result in a diminished range of motion at the shoulder joint, pain, weakness, and limitation of normal movements. The pain of a rotator cuff injury is often exacerbated by activities that will necessitate overhead positioning of the arm. Pain occurring at night is also common in such injuries as those affected will often roll onto the injured shoulder and are awoken as a result of the discomfort experienced. Weakness and a decreased range of motion are often a result of rotator cuff injury
The complexity of the shoulder joint provides for outstanding range of motion but also predisposes to injury.
1540 Shoulder Injuries and Disorders but pain alone results from bursitis and rotator cuff tendonitis. Each of these entities can be the result of what is known as the impingement syndrome. Impingement Syndrome Any activities whether work or sport related that result in repetitive overhead activities such as tennis or golf may result in impingement between the head of the humerus and its articulation with the scapula and surrounding supporting structures (i.e. the rotator cuff ). Impingement causes micro trauma to the rotator cuff, which results in a local inflammatory response causing pain and edema followed by poor functioning. The response to the injury is likely to perpetuate the condition and lead to further impingement. Bursitis of the shoulder refers to the inflammation of the bursa. The bursa is a closed sac containing fluid found in the shoulder joint surrounding the rotator cuff designed to lessen the friction of movement. Those suffering from bursitis will have the mildest of the impingement syndrome symptoms; with pain present with overhead activities usually subsiding while the arm is to the side. Range of motion will be limited by pain and muscle strength testing will demonstrate mild weakness. Treatment for impingement syndrome consists of conservative measures such as activity modification, possibly physical therapy, and unless contraindicated the administration of oral non-steroidal anti-inflammatory medications (NSAIDs). Modifying activities to minimize overhead activities is essential to eliminate the perpetuating inflammation of the rotator cuff impingement. Therapies such as heat and cold may also be of use following activities. If conservative treatment fails more aggressive pharmacologic treatment can be pursued with the administration of corticosteroid injection. But few injections should be given if used at all as the likelihood of a rotator cuff tear is greatly increased as the musculature is further weakened with each subsequent injection. Surgical intervention is indicated only after failure of prolonged conservative management. Fracture The bony structures of the shoulder are not without potential for injury. The clavicle is one of the most
frequently fractured bones. Clavicular fractures are especially common in children and usually result from the transmission of force through the outstretched bones of the forearm and arm during a fall. A fracture may also result from a fall in which force is encountered directly on the shoulder. Following fracture the muscular attachments may elevate the medial portion of the bone forming a readily palpable fragment. Fracture of the scapula is usually the result of severe trauma as may occur in pedestrian- vehicular accidents. These fractures will usually be accompanied by surrounding bony structure injuries as well. Such fractures of the scapula will require very little treatment based on the anatomical distribution of muscle tissue surrounding the bone on both sides. The humerus forms a critical portion of the shoulder joint and when fracture occurs the surgical neck of the humerus usually suffers the injury. Fracture of the humerus is especially common in the elderly following the presence of osteoporosis, whose demineralized bone has become brittle. These injuries often result from a minor fall on the hand with the force transmitted up the bones of the forearm and arm. Arthritis The complex interactions of the shoulder joint are not immune to the degenerative effects of arthritis. Two major designations exist with regard to the arthritic classifications, which are those of arthritis derived from either an osteopathic or rheumatologic origin. Osteoarthritis, commonly referred to as degenerative joint disease, is one of the most common causes of disability in the developed world. Individuals younger than 55 years of have an equal distribution of effected joints regardless of gender. The complex interactions of the shoulder joint are not immune to the degenerative effects of arthritis. Two major designations exist with regard to the arthritic classifications, which are those of arthritis derived from either an osteopathic or rheumatologic origin. Osteoarthritis, commonly referred to as degenerative joint disease, is one of the most common causes of disability in the developed world. Individuals younger than 55 years of have an equal distribution of effected joints regardless of
Sickle Cell Anemia
gender. Osteoarthritis mainly affects weight-bearing joints, and is more common in overweight and older persons. The joint pain of osteoarthritis is described as a deep aching sensation present in the involved joint. Generally movement of the involved joint provokes the pain and rest usually relieves the discomfort. With progression of the disease the pain may become persistent. Such advanced disease may be responsible for nocturnal pain and sleep interference, particularly in advanced osteoarthritis. Rheumatoid arthritis is a systemic disease of unknown origin. The disease is more prevalent in women and predominantly affects connective tissue; arthritis is the dominant clinical manifestation. This form of arthritis frequently involves many joints. Arthritis of the shoulder is likely to be present with multiple joint involvements, especially those of the hands and feet. The pathology of rheumatoid arthritis varies from that of osteoarthritis with the former representing an inflammatory process and the latter representing a non- inflammatory condition. In addition, osteoarthritis created a thinning of connective articular membranes where rheumatoid arthritis will be accompanied by thickening of articular soft tissue, with extension of synovial tissue over articular cartilages, which become eroded; the course is variable but often is chronic and progressive, SEE ALSO: Arthritis; Disabilities; Fractures; Surgery. BIBLIOGRAPHY. Dennis L. Kasper, Harrison’s Principles
of Internal Medicine, 16th ed. (McGraw-Hill, 2005); Keith L. Moorse and Arthur F. Dailey, Clinically Oriented Anatomy, 5th ed. (Lippincott Williams and Wilkins, 2006); Randall King, Rheumatoid Arthritis, www.emedicine. com/EMERG/topic48.htm (July 2006); Robert A. Novelline, Sqiures Fundamentals of Radiology, 6th ed. (Harvard University Press, 2004); Ego Seeman and Pierre D. Delmas, “Bone Quality—The Material and Structural Basis of Bone, Strength and Fragility,” New England Journal of Medicine (v.354, 2006); Scott Welsch and Mark Veenstra, Shoulder Dislocation, www.emedicine.com/orthoped/ topic440.htm (July 2004). Donald Hohman, Jr. Kern Medical Center
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Sickle Cell Anemia Sickle cell disease (SCD) is an incurable genetic disorder affecting the capability to produce healthy red blood cells, found in hemoglobin, which carry oxygen produced by the lungs to other cells of the body. In patients with SCD, hemoglobin cells cluster together to form sickle-shaped structures that block the circulation of oxygen-rich blood. Symptoms associated with SCD include anemia, fever, fatigue, breathlessness, rapid heart beat, susceptibility to infections, intensive bouts with pain, delayed growth, leg ulcers, and jaundice. The most life-threatening aspects of SCD involve stroke, chronic infections, tissue damage, and cardiovascular disease. The likelihood of seizures may increase with age. In the United States, sickle cell diseases are found primarily among African-Americans. According to current estimates, approximately one in 12 black children is born with sickle cell trait. One in 600 black children is born with sickle cell anemia. Other Americans who test positive for SCD generally come from families with African-American ancestors. Parents who have sickle cell trait (SCT) are not ill, but they may pass SCD to their offspring. If both parents have sickle cell trait, there is a 25 percent likelihood of producing a child with SCD. In addition to sickle cell anemia, which is the most severe form of SCD, researchers have identified three other milder forms of the disease. Sickle cell hemoglobin C disease occurs in patients that inherited the sickle cell gene from only one parent. Roughly half of the cells in the hemoglobin of these individuals may be sickle-shaped. Patients who are diagnosed with sickle cell Beta2 and Beta3 thalassemia disease have inherited the gene that produces sickle hemoglobin from one parent and the gene that produces thalassemia (a hereditary form of anemia mainly found in Mediterranean countries) from the other. Many people use the term “sickle cell anemia” (SCA) to refer to all sickle cell diseases. Research Sickle cell anemia was first identified by American physician James B. Herrick (1861–1954) in 1904. In the course of treating the illness of a black student from Grenada who became ill while attending the Chicago College of Dental Surgery, Herrick discov-
1542 Sickle Cell Anemia ered that some of the student’s red blood cells were sickle-like in shape. Subsequent research revealed that most or all hemoglobin cells are sickle shaped in SCA patients. Sickled cells tend to be both rigid and fragile. The rigid shape prevents blood from flowing normally and inhibits the production of healthy hemoglobin. A normal blood cell lives for approximately 120 days. In a sickle cell patient, however, that life span is reduced to between six and 30 days. Consequently, the patient’s bone marrow is unable to replace deteriorating cells, resulting in persistent anemia. There is strong evidence that SCA had been present in some cultures for centuries where it was known by a variety of names that tended to mirror the effects of the disease. Among the Ga of Ghana, for instance, the disease was known as chwechweechwe, which represented the recurrent gnawing pain of SCA. Herrick’s identification of SCA launched the first stage of modern sickle cell research, which focused on understanding the effects of the disease. By mid-20th century, biochemists and geneticists had identified the difference between sickle cell trait and sickle cell disease. In 1949, Noble laureate Linus Pauling (1901-1994) determined that SCS was molecular in origin, noting that hemoglobin molecules of individuals with sickle cell conditions were chemically different from others in the general population. Researchers also documented the genetic benefits of sickle cell trait and thalassemia in countries in where malaria was endemic because of the inherent resistance it provided. However, no effort was made to test at-risk individuals before they gave birth to children with sickle cell disease. The birth of the civil rights movements in the late 1950s focused public attention of SCA, leading to significant advances. In 1972, Congress passed the Sickle Cell Anemia Control Act and began funding sickle cell research and programs. Researchers also began examining the lifelong psychological factors associated with SCA. In 1974 Charles F. Whitten and J. Fischhoff discovered that many parents did not understand the difference between sickle cell trait and sickle cell disease. They also found that mothers, who tended to be the major caregivers, were unable to provide support because they did not understand the effects of SCA on their children’s bodies and minds. More recent studies have examined SCD in adults who are often unable to hold jobs because of repeated hospitalization.
The National Institutes of Health (NIH) are heavily involved in promoting understanding, diagnosis, and treatment of SCD. Sickle cell centers have also been established in many parts of the world, and the base of knowledge has continued to expand. Current research efforts focus on preventing SCD, working toward a cure, and improving health management for sickle cell patients. Tests conducted on children whose parents have sickle cell trait have allowed researchers to identify at-risk children and begin treatment before serious problems occur. New drugs and technologies have greatly improved quality of life as well as life expectancy for most SCD patients. Effects and treatment Recurrent and unpredictable bouts with pain are a way of life for many SCA patients. Most repeated hospitalizations occur in response to these attacks that tend to center in the extremities, abdomen, and chest. Sickle cell patients have a low tolerance for physical exercise; and joint deterioration, tissue damage, and gallstones are common. Some males experience nonsexual prolonged, painful erections. Infants who have been diagnosed with sickle cell anemia may experience swelling of the hands and feet. If sickled cells pool suddenly in the spleen, sudden infant death syndrome (SIDS) may occur. Infants with sickle cell also die from infections that occur rapidly before parents are aware of the problem. Children who survive infancy may not grow at normal rates, and they may experience delayed onset of puberty. Sickle cell patients of all ages have a higher than normal susceptibility to infections and strokes. There is no cure for SCA; and despite decades of research, scientists have not discovered a reliable way to keep affected cells from sickling or to convert sickle cells to normal blood cells. Because of this, there is no way to prevent blocked cells from occurring or to remove blockage once it has occurred. Treatment includes bed rest when necessary, drinking lots of fluids, taking medications according to instructions, and active pain management. Blood transfusions that infuse patients’ blood cells with non-sickled cells are used in cases of severe anemia and when sudden and severe pooling of the blood occurs in vital organs. Infections are treated with antibiotics. Children under the age of five may receive antibiotics daily. Vaccination therapy for children in-
Sierra Leone
cludes a pneumococcal conjugate vaccine, a polysaccharide pneumococcal vaccine, an annual influenza shot after six months of age, and meningococcal vaccinations after two years of age. Surgery may be necessary to remove gallstones or to replace deteriorated hip joints. Bone marrow transplants have also been used with some patients to replace marrow destroyed by sickled cells Children who experience SCA-related strokes are in great danger from subsequent attacks, and they may become paralyzed or mentally impaired. Blood transfusions are a regular element of treatment for children who have suffered strokes. Since patients who have received repeated transfusions have high levels of iron that cannot be eliminated through normal body processes, stroke patients are given chelators to promote the elimination of iron. Experiments with stem cell research in stroke patients have been successful. However, stem cell research continues to be a controversial political issue, and this option may be limited by the state of residence, general health factors, and finances. Since 1983, a simple blood test has been used to identify sickle cell trait. Individuals who have the trait may decide not to marry, and many at-risk couples are tested before they decide to have children. If they decide to do so, a fetus can be tested for SCD through DNA tests at four months, through placenta analysis at nine weeks, and through amniotic fluid examination at 15 weeks. If tests are positive, a decision must be made on whether or not to terminate the pregnancy. Most states now require mandatory testing of all newborns for SCD. In the long run, gene therapy is likely to prove the most effective weapon against SCA. Drugs such as hydroxyurea that are used to battle leukemia are considered effective in circumventing SCA by generating a “switch” that regulates the production of nonsickling cells. Use of the drug has also reduced incidences of strokes, infections, and other common SCA symptoms. However, the drug is contraindicated for a number of patients. In the area of fertility, there has been some success with removing eggs from ovaries to test for sickle cell. Reducing random production of fetuses with SCD has resulted in fewer incidences of infants being born with SCA. However, these procedures are expensive and may not be available to all parents with SCT.
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See Also: Epilepsy; Genes and Gene Therapy; Genetic
Counseling; Genetic Disorders; Leukemia; Malaria; Pain; Stroke.
BIBLIOGRAPHY. Ronald L. Braithwaite and Sandra E. Tay-
lor, eds., Health Issues in the Black Community (JosseyBass, 2001); J. Fischhoff and Charles F. Whitten, “Psychosocial effects of Sickle Cell Disease,” Archives of Internal Medicine (v.133, 1974); Melanie Apel Gordon, Let’s Talk about Sickle Cell Anemia (PowerKids Press, 2000); Eleanor Mayfield, New Hope for People with Sickle Cell Anemia (United States Department of Agriculture, 1999); Satyen R. Mehta, et al., “Opportunities to Improve Outcomes in Sickle Cell Disease,” American Family Physician (July 2006); Keith Wailoo, Dying in the City of the Blues: Sickle Cell Anemia and the Politics of Race and Health (University of North Carolina Press, 2001); Keith Wailoo and Stephen Pemberton, The Troubled Dream of Genetic Medicine: Ethnicity and Innovation in Tay-Sachs, Cystic Fibrosis, and Sickle Cell Disease (Johns Hopkins University Press, 2006); Charles F. Whitten and John F. Bertles, eds., Sickle Cell Disease (Academy of Sciences, 1989). Elizabeth R. Purdy, Ph.D. Independent Scholar
Sierra Leone Sierra Leone is located in western Africa, between Guinea and Liberia on the Atlantic Coast. Once a colony for the Portuguese and the British, it became an independent republic in 1961. Civil war between 1991 and 2002 killed around 50,000 people and displaced 2 million more. While it has taken steps to regain political and economic standing in the world community, quality of life remains low and almost 70 percent of Sierre Leoneans live in poverty. The population is 6,144,600, growing at 2.3 percent annually. The birth rate is 45.41 per 1,000 and the death rate is 22.64 per 1,000. Thousands of refugees still live in neighboring countries, and continue to trickle back. Median age is 17.5 years. Life expectancy is 38.36 years for males and 42.87 years for females. Gross national income is $220, with 57 percent of the population living on less than $1 a
1544 Singapore day. Fifty percent of the total population may be undernourished. Communicable diseases flourish in Sierra Leone. A 2004 survey by the Ministry of Health found that in four districts, the most common causes of morbidity and mortality were malaria, diarrhea, pneumonia, intestinal worms, scabies, anemia, acute respiratory infections, sexually transmitted diseases, tuberculosis, yellow fever, measles, leprosy, polio, meningitis, and AIDS. Malaria alone is responsible for 35 percent of outpatient cases and kills about 312 per 100,000, with a much higher rate in young children. Much of the country’s water and sewerage infrastructure was damaged or neglected during the war, exposing people to typhoid, hepatitis A, schistosomiasis and cholera. There was an outbreak of Lassa fever in 2007. AIDS and tuberculosis are believed to have spread rapidly during the war, and the adult prevalence rate for HIV may be as high as 7 percent. Tuberculosis prevalence is 847 diagnosed cases per 100,000, with 58 deaths per 100,000. Women and children receive free healthcare from the government, but it has done little to diminish Sierra Leone’s staggeringly high rates of child and maternal mortality. Only 4 percent of women have access to contraception, and the total fertility rate of 6 children per woman reflects this. Less than 70 percent receive prenatal care, and 42 percent have trained support during childbirth. The maternal mortality rate is estimated at 2,000 deaths per 100,000 live births, easily among the highest in the planet. Child mortality is also among the world’s highest, with 282 out of 1,000 children dying before their fifth birthday. Immunization rates are about 60 percent. Despite the fact that 1,500 per 100,000 children die of malaria, only 2 percent of them sleep under insecticide-treated nets. In 2003, UNICEF stated that 46 percent of deaths in children under 5 are in part attributable to poor nutrition. There are more than 340,000 orphans under the age of 17 within the country. A large percentage of medical facilities were damaged during the war, and now need rebuiling, resupply, and upgraded equipment; 80 percent of rural health centers were completely destroyed. Overall, 90 percent of primary health centers are open but barely functioning. Fifty percent of the health system is run by the government, with the remainder in the hands
of non-governmental organizations, for-profit institutions, and faith-based groups. Healthcare absorbs 3.3 percent of the gross domestic product, and Sierra Leone works with international donors on major initiatives. All agree that rebuilding will take time. See Also: Healthcare, Africa; Bibliography. Central Intelligence Agency, “Sierra Leone,”
CIA World Factbook. www.cia.gov/library/publications/theworld-factbook/geos/sl.html (cited June 2007); The Joint United Nations Programme on HIV/AIDS, “Sierra Leone,” UNAIDS: www.unaids.org/en/Regions_Countries/Countries/sierraleone.asp (cited June 2007); Republic of Sierra Leone, “Ministry of Health and Sanitation Official Web site,” http://www.health.sl/drwebsite/publish/index.shtml (cited June 2007); Research Africa, “Sierra Leone,” Researchafrica.rti. org. www.researchafrica.rti.org/index.cfm?fuseaction=home. country_view&country_id=37 (cited June 2007); United Nations Children’s Fund, “Sierra Leone—Statistics,” www.unicef. org/infobycountry/sierraleone_statistics.html#28 (cited June 2007); World Health Organization, “Health Action in Crisis: Sierra Leone,” www.who.int/hac/crises/sle/background/2004/ SierraLeone_Jun06.pdf (cited June 2007). Heather K. Michon Independent Scholar
Singapore Ranking as the 29th richest naton in the world with a per capita income of $28,600, the heavily industrialized nation of Singapore enjoys overall good health. Singapore’s prosperous economy is based in large part on strong international trading ties, particularly in electronics and manufacturing, making Singapore one of the busiest ports in the entire world. Singaporeans are generally literate, although there is a gap between male (96.6 percent) and female (88.6 percent) literacy. With virtually no poverty, an unemployment rate of only 3.1 percent, and a Gini Index of 42.5, most Singaporeans are relatively comfortable. Access to healthcare, safe drinking water, and improved sanitation is universal. The United Nations Development Programme (UNDP) Human Development Reports
rank Singapore 25th of 177 countries in overall quality-of-life issues. Under British rule, Singapore enjoyed health benefits common to all British colonies. Following independence in 1965, the country experienced a rapid drop in the proportion of government spending allotted to healthcare. Over the following decades, however, as the government committed more resources to healthcare, the overall quality of health improved. By 1985, the government had quadrupled 1960 healthcare expenditures. In 1960, Singapore could claim only one physician for every 2,573 patients. By 1985, that ratio had dropped to one for 972 patients. By 2006, the number of physicians had narrowed to 1.40 per 1,000 population. Likewise, 4.24 nurses, 0.26 dentists, and 0.28 pharmacists are now available per 1,000 population. Currently, Singapore spends 4.5 percent of its Gross Domestic Product (GDP) on healthcare and allots $1,157 (international dollars) for health expenditures per capita. The government is responsible for 36.1 percent of all healthcare costs, leaving 63.0 percent to be financed by the private sector. Just over 97 percent of private sector spending involves out-of-pocket expenditures. Social Security funding comprises 21.5 percent of all government healthcare expenses. In 2001, the government announced the establishment of the Health Sciences Authority to oversee health issues. Singapore has been steadily increasing life expectancy since the 1960s when the average Singaporean lived to only 63 years. Today, the population of 4,292,150 has a life expectancy of 81.71 years, the fourth highest in the world. Singaporean females outlive males an average of five years. This increase in life expectancy is indicative of Singapore’s subsidized healthcare and of well-developed public and private pension plans. This safety net is extremely valuable to the elderly population, one-fourth of whom are over the age of 75. However, the economy suffers as the rapidly increasing elderly population draws heavily on the resources of a smaller, younger, working population. Singapore has the third lowest fertility rate in the world at 1.06 children per woman. Government family planning programs have served as the model for many developing nations. Smaller families have led to an increase in the number of women in the work-
Singapore
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force, with female representation more than doubling between 1957 and 1985. All births are attended by skilled personnel. Maternal mortality is low at 13.3 per 100,000 live births. In 1960, 34.9 infant deaths occurred for every 1,000 live births. Today, Singapore has the lowest infant mortality rate in the world at 2.29 deaths per 1,000 live births and an under-5 mortality rate of 3 deaths per 1,000 live births. Only 1 percent of Singaporean children fail to receive tuberculosis vaccinations, and only 6 percent have not been immunized against diphtheria pertussis, and tetanus (DPT) and measles. In the 1950s and 1960s, tuberculosis was the leading cause of death among Singaporeans, but the disease has virtually disappeared in the 21st century. Escaping the HIV/AIDS epidemic that is ravaging much of Asia, Singapore’s rate is only 0.2 percent. While 4,100 Singaporeans have HIV/AIDS, the disease has claimed fewer than 200 lives. In 2003, Singapore experienced an outbreak of sudden acute respiratory syndrome (SARS) that dampened tourism and negatively affected both the economy and the health of the population. The leading causes of death in Singapore mirror those in other industrialized nations: heart disease, cancer, and pneumonia (in ranked order). SEE ALSO: Birth Rate; Healthcare, Asia and Oceania. BIBLIOGRAPHY. Central Intelligence Agency, “Singapore,”
World Factbook www.cia.gov/cia/publications/factbook/ geos/sn.html (cited April 2007); Commission on the Status of Women, “Singapore,” www.un.org/womenwatch/daw/ Review/responses/SINGAPORE-English.pdf (cited April 2007); Katherine McFate, et al., Poverty, Inequality, and the Future of Social Policy: Western States in the New World Order (Russell Sage, 1995); Carlos Gerardo Molina and Jose Nunez del Arco, eds., Health Services in Latin America and Asia (Johns Hopkins University Press, 2001); Kernial Singh Sandhu and Paul Wheatley, Management of Success: The Moulding of Modern Singapore (Westview, 1990); World Bank, “Singapore Data Profile,” http://devdata.worldbank. org/external/CPProfile.asp?PTYPE=CP&CCODE=SGP (cited April 2007); World Health Organization, “Singapore,” www.who.int/countries/sgp/en/ (cited April 2007). Elizabeth R. Purdy, Ph.D. Independent Scholar
1546 Sinusitis
Sinusitis Sinusitis is a disease causing an inflammation of the mucosal cells lining the sinus and nasal cavities. After ongoing speculation, the term sinusitis has been replaced by the more specific term rhinosinusitis. Rhinosinusitis can occur in children or adults and is frequently seen in the offices of primary care physicians. Rhinosinusitis most commonly develops within the paranasal sinuses following a viral upper respiratory infection. As fluid collects and stagnates within the sinus cavities, greater inflammation develops and obstructs outward fluid passage, encouraging normal microbial flora to overgrow. Given the predisposition to occur post viral illness, it is not uncommon for a patient with rhinosinusitis to report having cold symptoms that initially resolved but later returned. Rhinosinusitis can cohabitate with other conditions such as allergic rhinitis or asthma, thus clinical distinction is important for proper treatment. Patients often complain of a wide array of symptoms ranging from headache, foul-smelling nasal discharge, halitosis, ear fullness, or cough. Most recent guidelines govern treatment based upon symptom severity and duration. Symptoms are categorized as major or minor while duration is classified as acute, subacute, or chronic. The more prominent major factors include facial pain/pressure, nasal congestion/obstruction, and thick, yellow nasal
Acute symptoms of sinusitis last for less than four weeks, while chronic symptoms last for more than three months.
discharge. Minor criteria include dental pain, halitosis, headache, or a cough not due to any other cause. Moreover, symptom durations are independent of the prior viral respiratory infection. Acute symptoms last for less than four weeks, while chronic symptoms last for more than three months. Subacute illness lasts between four weeks and three months. Risk factors for rhinosinusitis include anatomical abnormalities (i.e., deviated septum, polyps) or the presence of another chronic respiratory disease (i.e., cystic fibrosis). Although most causes of rhinosinusitis are viral, there exists an opportunity for normal bacterial flora to take advantage of an already overstressed, occupied immune system and cause rhinosinusitis directly after a viral respiratory illness. Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis are the most common bacteria in such cases. In diabetics or immunocompromised individuals, fungal causes should also be considered. Diagnosing rhinosinusitis begins with a thorough account of the disease course from the patient. Subsequently, a physical exam with close attention to the head and neck regions are performed. The diagnosis of rhinosinusitis is usually evident following the history and physical exam; however, in complicated or immunosuppressed cases, the physician may seek an imaging modality. General radiographs of the sinuses offer a poor yield for results and are nonspecific toward determining a bacterial etiology. A computed tomography (CT) scan of the sinuses is more accurate for visualizing fluid but is also nonspecific to diagnose a microbial etiology. The only gold standard, and rarely performed, diagnostic test to distinguish a microbial presence is sinus puncture. Sinus puncture entails a fluid sample being directly drawn from the sinus cavity and sent to the laboratory for analysis. Current treatment guidelines favor use of antibiotics only when symptoms are severe, last beyond seven days, or include prominent yellow nasal discharge. The optimal antibiotic regimen should be narrow spectrum and targeted toward the most likely bacterial agents previously mentioned. Three most common first-line medications include amoxicillin, doxycycline, and trimethoprim/sulfamethoxazole. Although many studies are unclear in the duration of antibiotic use, most agree employing medication beyond three to five days does not impact overall effectiveness or shorten the remaining illness course. Intra-
Sjogren’s Syndrome
nasal steroids offer mild relief in symptoms, but also have not been proven to effectively alter the course of the disease. Similarly, oral or intranasal decongestants containing pseudoephedrine or oxymetazoline, respectively, tend to shrink inflamed nasal passages and encourage fluid drainage. However, prolonged use beyond five days is discouraged as a rebound effect involving increased nasal congestion is likely to ensue. The most promising intranasal remedy is to utilize a hypertonic nasal saline irrigation daily to improve symptoms, and decrease the need for other intranasal medications. Infrequently, the complications of rhinosinusitis include bone infections in the surrounding head regions, or abscess development within the sinus cavities. In these cases, or in cases refractory to treatment, the patient may need to seek treatment from an otolaryngologist or from an allergist for further evaluation. Surgery is reserved for complicated cases and may be performed with an endoscope, a less invasive technique utilizing a camera to perform surgical procedures. The prognosis for rhinosinusitis is excellent in cases uncomplicated by any other comorbidities, regardless of antibiotic use. SEE ALSO: Asthma; Bacterial Infections; Common Cold;
Otolaryngology; Respiratory Diseases (General).
BIBLIOGRAPHY. Dynamed, “Acute Sinusitis,” www.ebsco-
host.com/dynamed (cited April 2007); Donald C. Lanza and David W. Kennedy, “Adult Rhinosinusitis Defined,” Otolaryngology: Head and Neck Surgery (v.117/3, 1997); Vincenza Snow, et al., “Principles of Appropriate Antibiotic Use for Acute Sinusitis in Adults,” Annals of Internal Medicine (v.134/6, 2001). Stephanie F. Ingram University of South Florida
Sjogren’s Syndrome Sjogren’s syndrome is a chronic inflammatory disease characterized by decreased lacrimal and salivary gland secretion. This causes dry eyes (keratoconjunctivitis sicca) and dry mouth (xerostomia), which are hallmarks of this condition. Secretions are also di-
1547
minished in other exocrine glands of the body including those in the respiratory, gastrointestinal, and vaginal tracts. This results in dryness of the nose, trachea, bronchi, vagina, as well as the skin. The disease is primary, meaning that it occurs independently of other conditions, in roughly 50 percent of patients with Sjogren’s syndrome. In the other half of patients, Sjogren’s occurs concurrently with other conditions such as rheumatoid arthritis, systemic lupus erythematosus, and scleroderma. It is mainly a disease of middleaged women; the mean age of onset is 50 years of age with a female-to-male ratio of 9:1. Sjogren’s syndrome can, however, occur in the pediatric population. The prevalence in the general population is approximately 0.5 to 1 percent. Pathology Although the exact cause of Sjogren’s syndrome is unknown, there is growing scientific support for a genetic (inherited) etiology. Research has shown that cell-mediated immune mechanisms are likely to be involved in Sjogren’s syndrome. Lymphocytes, primarily CD4 T cells, invade the exocrine glands throughout the body. The disruption in normal function and composition causes the glands to produce smaller amounts of secretions. There is also evidence of B cell abnormalities; the B cells are believed to be hyperreactive. They act as autoantibodies which attack the patient’s own body by infiltrating the exocrine glands. It is common for patients with Sjogren’s syndrome to have hypergammaglobulinemia (high levels of IgG type B cells), high levels of rheumatoid factor, and autoantibodies to nuclear and cytoplasmic proteins Ro and La (anti-Ro and anti-La, also known as SS-A and SS-B autoantibodies, respectively). Antibodies to alpha-fodrin, a protein specific to the salivary glands, have been found in the blood of Sjogren’s syndrome patients. In addition to these alterations of the immune system, there are also changes in the gland structure of patients with Sjogren’s syndrome. The epithelial cells of the glands undergo apoptotic changes. In other words, the cells incur modifications which ultimately result in their death. Ductal and acinar epithelial cells inappropriately produce proteins that induce inflammation and perpetuate autoimmune injury to the gland. These proteins serve to attract more T and B cells to each gland.
1548 Sjogren’s Syndrome Symptoms and Signs The most common complaint is dryness of the mouth. This is often associated with a burning discomfort and difficulty with chewing and swallowing dry foods. The inability to swallow dry food without liquid, or the need to wake up during the night to sip some water has been described as the “cream cracker” sign. On the other hand, patients will also often complain of having to get up at night to urinate, and this is due to the large volume of water they consume during the day to relieve dry mouth. Referral to a physician is often initiated by a patient’s dentist, because accelerated development of dental caries is associated with decreased oral secretions. Dry mucous membranes will appear erythematous (red), and the tongue frequently becomes fissured and ulcerated. Stones can develop in the salivary gland ducts. The major ocular finding is keratoconjunctivitis sicca. Patients develop inflammation of the lacrimal gland, the gland responsible for producing tears. The inflammation prevents the tear gland from releasing fluid, and so the eyes consequently become dry and irritated. Decreased tear production can lead to a “gritty” sensation in the eye. This is sometimes described as feeling like sand in the eye. Other symptoms include burning, itching, accumulation of thick mucoid material during the night, sensitivity to light (photophobia), and eye pain. Dryness can eventually result in serious abrasions or ulcerations of the cornea. Extraglandular problems in Sjogren’s syndrome include joint pain or inflammation (arthritis), lung inflammation, lymph node enlargement, kidney, nerve, and muscle disease. Dryness of the nose, posterior oropharynx, larynx, and respiratory tract can lead to bloody noses (epistaxis), voice disorders (dysphonia), recurrent otitis media, tracheobronchitis, and pneumonia. Dryness of the reproductive tract can cause pain during intercourse. Gastrointestinal consequences other than dry mouth include gastroesophageal reflux and primary biliary cirrhosis, an autoimmune disease of the liver that leads to scarring of the liver tissue. Patients who have comorbid rheumatoid arthritis are at increased risk for developing synovitis (inflammation of the synovial membrane at a joint). Vasculitis (inflammation of the blood vessels) is a rare but serious complica-
tion of Sjogren’s syndrome. Inflammation can impede blood flow and ultimately damage the body tissues supplied by the vessels. Diagnosis The diagnosis of Sjogren’s syndrome is currently based on clinical and laboratory findings. Common laboratory findings include anemia, leucopenia (low white blood cell count), and an elevated erythrocyte sedimentation rate (marker of inflammation). The American-European Consensus Group Classification for Sjogren’s syndrome includes six criteria: Ocular symptoms • Daily persistent troublesome dry eyes for more than three months • Recurrent sensation of sand or gravel in the eyes • Use of a tear substitute more than three times a day Oral symptoms • Daily feeling of dry mouth for more than three months • Recurrent or persistent swollen salivary glands as an adult • Need to frequently drink liquids to aid in swallowing dry foods Positive Schrimer’s test or Rose Bengal score • Schrimer’s test can be done in a doctor’s office. It determines ocular dryness by testing the eye’s ability to wet a small testing paper strip placed under the eyelid. • Rose Bengal testing reveals punctuate staining of the conjunctiva and cornea. • More sophisticated eye testing can be done by an eye specialist (ophthalmologist). Abnormal lower lip biopsy • Glands of the oral mucosa, similar to those of the ocular mucosa, will be positive for lymphocytic infiltration. • The biopsy is done under local anesthesia by a surgeon. • Demonstration of lymphocytic infiltration in a biopsy from the minor labial salivary glands is the most specific and sensitive single test for Sjogren’s syndrome. Positive result for unstimulated whole salivary flow • Less than or equal to 1.5 mL in 15 minutes. Antibodies to Ro (SS-A) or La (SS-B), or both.
Skin Cancer
Treatment Currently, there is no cure for Sjogren’s syndrome. However, proper treatment helps to relieve symptoms and lessen the effects of the dryness. Due to the varied presentation of Sjogren’s syndrome, the specific symptoms of each patient must be taken into consideration when designing a treatment plan. Patients with dry mouth are encouraged to drink plenty of fluids and to use a humidifier to add moisture to the air they breathe. It is crucial to tell patients to maintain good oral hygiene; this includes regular use of fluoride toothpaste and mouthwash as well as regular dental examinations. Some toothpastes have artificial saliva components. Dryness may be avoided by sipping fluids throughout the day, using sugarless gum or candy, and using a saliva substitute containing carboxymethylcellulose as a mouthwash (Biotene). If conservative measures are ineffective, prescription medications such as pilocarpine (Salagen®) and cevimeline (Evoxac®) can be used to stimulate saliva production. The discomfort of dry eyes can be alleviated by artificial tears and nightly application of eye lubricants. In order to protect the eyes from the drying effects of wind, shielded glasses can be worn. Similarly, patients should minimize the use of hair dryers. If the dryness does not improve with these measures, the tear duct can be plugged by an ophthalmologist in order to keep the eye lubricated by blocking the tears from draining off the eye. Prescription medications include cyclosporine eyedrops (Restasis®) which decrease tear gland inflammation to prevent blockage of the duct. Soft contact lenses have also been used with success in patients with Sjogren’s syndrome. Other symptomatic therapies include the use of moisturizing skin creams and saline nasal sprays. Vaginal lubricant is a consideration for relief of dyspareunia during sexual intercourse. Nonsteroidal antiinflammatory drugs have helped to ease symptoms of arthritis and other connective tissue diseases. Immunosuppressive medications, such as cortisone (PredniSONE®), azathioprine (Imuran®), and cyclophosphamide (Cytoxan®), have been effective in treating serious complications of Sjogren’s syndrome such as vasculitis. SEE ALSO: Autoimmune Diseases; Connective Tissue Dis-
orders; Rheumatoid Arthritis; Scleroderma.
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BIBLIOGRAPHY. Mark H. Beers and Robert Berkow, eds., “Sjogren’s Syndrome,” The Merck Manual (Merck, 1999); Haralampos M. Moutsopoulos, “Sjogren’s Syndrome,” Primer of Rheumatic Diseases (Arthritis Foundation, 1993); Patrick J. W. Venables, “Sjogren’s Syndrome,” Best Practice & Research Clinical Rheumatology (Elsevier, 2004).
Stacy A. Frye Michigan State University
Skin Cancer Every year, nearly 60,000 people worldwide die from skin cancer caused by exposure to too much sun, according to the World Health Organization (WHO). The first-ever estimate of the global health burden caused by the sun’s ultraviolet (UV) radiation shows about 48,000 deaths each year are caused by malignant melanoma, while another 12,000 deaths are caused by other types of skin cancer. Melanoma is most common among whites, but it is also a threat to people of other races. Whites make up the vast majority of the cases (almost 70 percent). Hispanics account for nearly 29 percent and blacks represent almost 2 percent. However, blacks and Hispanics are more likely than whites to be diagnosed with melanoma that has spread beyond the skin. Most scientific studies and public health efforts about melanoma have focused on whites. Boosting melanoma awareness in nonwhite racial and ethnic groups is encouraged to initiate early melanoma detection. Like many other cancers and diseases, the odds of survival are best when melanoma is detected in its early stages. Melanoma survival rose from 68 percent in the early 1970s to 92 percent in recent years for whites. Such advances, however, have not occurred in other segments of the population. Researchers note that access to medical care may have been an issue. Skin color can vary widely within races. In general, lighter complexion skin that burns easily harbors less melanocytes and is at highest risk of both melanoma and nonmelanoma skin cancer. While everyone should check their skin for suspicious changes such as irregularly shaped moles, it can be difficult to spot such changes, especially on darker skin. Doctors can do skin exams as part of a routine checkup.
1550 Skin Cancer The skin is the largest human organ. More specifically, the stratum corneum of the epidermis is the outermost human tissue. The skin’s visibility to the naked eye makes symptoms easily recognizable to the average patient, increasing the probability of detecting new or changing lesions. On the other hand, while visceral pathology can present with varying systemic symptoms, the skin provides an easily accessible area for biopsy. The overt visibility of the skin can account for the fact that dermatology-related issues comprise 20 percent of primary care doctor visits. Furthermore, because of the size and vulnerability of the skin, the Centers for Disease Control and Prevention reports that skin neoplasia (cancer) is the leading form of cancer in the United States. Similar to other medical specialties, one must first understand the vernacular of dermatology before delving further into skin cancer. Primary skin lesions are the macule, patch, papule, plaque, nodule, vesicle, bulla, and pustule. A macule is a primary lesion that is characterized by change in color without any elevation and measuring less than 1 centimeter; a patch is a larger flat area of color change. Unlike a macule or patch, a papule is palpable; a plaque is a larger palpable coalition of papules. A nodule is an elevated skin lesion larger than 1 centimeter. A vesicle is a small blister and a bulla is a larger blister. A pustule is a collection of white blood cells, mostly neutrophils, greatly exemplified in acne vulgaris, androgenically stimulated pimples arising from sebhorreic glands. Other examples of important dermatologic vocabulary important in the differential diagnosis of skin cancer are scaling and include nevi and nonmalignant birthmarks. Skin neoplasia (cancer) can arise in the epidermis or dermis and is separated into two categories: benign and premalignant lesions, and malignant lesions. Carcinoma refers to cancer arising from epithelial tissue and sarcoma is neoplasia arising from connective tissue. Benign dermal cancer can arise from dermal structures such as connective tissue, vasculature, fat, muscle, and nerves. Dermatofibroma and keloids are the most commonly seen benign connective tissue tumors. Dermatofibroma presents as compressible papules that are dark in color. Keloids present with an upper chest and back distribution and with higher incidence in African Americans. Neurofibromas, lipomas, and hemiangiomas are benign dermal tumors that arise in the nerves, fat,
and blood vessels, respectively. Each type of benign dermal neoplasm has the potential to progress to their respective malignant form. Benign epidermal cancer can stem from epidermal structures such as the keratinocyte, basal cell, or melanocyte. Uncontrollable keratinocyte growth presents in its benign form as sebhorreic keratosis, which can be mistaken for melanomas because of their similar color. In its malignant form, keratinocytes present as actinic (sun-related) keratosis. Uncontrollable melanocyte growth presents in its benign form as a nevus during childhood and continues into adulthood. There are three major forms of malignant epidermal tumors, all of which have great correlation with sun exposure and appear to occur twice as likely in men as in women. Therefore, greater incidence is evident in higher temperate states such as California and Arizona where individuals spend more time outdoors for business, travel, and leisure. Because of the abundance of their catalyst, namely sun exposure, malignant epidermal tumors are found in much higher numbers than malignant dermal tumors. Basal cell carcinoma (BCC) is the most common (it is estimated that nearly 1 million incidences occur annually) while being the least invasive form of malignant epidermal cancer and having the lowest potential for metastasis. Clinically, the presentation of BCC is best known as a pearly papule. The basal cell is the stem cell of the epidermis and is the origin of BCC. Upon further examination of a BCC on a patient’s skin, one will notice that these basal cells that usually reside in the outer layer of the skin, the epidermis, are found in much greater numbers invading into the dermis. Squamous cell carcinoma (SCC) is intermediate in incidence and also in neoplastic potential. There is an estimated 200,000 to 300,000 cases of SCC per year in the United States. Similar to BCC, SCC is also dependent on sun exposure; however, unlike BCC, SCC does have the potential to metastasize. In addition, SCC can present in immunosuppressed patients infected with the human papillomavirus (HPV). The most pathologically invasive form of skin cancer is the melanoma. As mentioned before, melanoma represents the malignant overgrowth of melanocytes in comparison to a melanocyte nevus, the benign form. Like both SCC and BCC, melanoma is highly dependent upon sun exposure. Clinicians refer
Skin Diseases (General)
to its early form as a malignant freckle; however, it progresses into a black lesion on the skin. Melanoma, which has the highest incidence to metastasize, presents itself in other organs in a similar fashion as in the skin—as black lesions, and represents a less favorable outcome. Nevertheless, death from nonmetastatic cancer is very unlikely and is seen most in the elderly and immunosuppressed. Treatment for skin tumors vary depending on the invasiveness of the neoplasm. The earlier the patient recognizes the neoplasm, the less invasive and the easier the cancer will likely be to remove. Simple melanoma, BCC, and SCC excision can be conducted in an outpatient setting under local anesthesia delivered by the physician. Mohs micrographic surgery is a more innovative method for BCC and SCC removal where the epidermis is sequentially cut into horizontal slices layer by layer until the cancer is totally removed. This procedure requires finer attention and care because each horizontally cut layer must be read under the microscope by the dermatologist until the cancer is fully eliminated. Mohs micrographic surgery provides much better results with lower recurrence rates of BCC and SCC. This procedure is typically reserved for skin cancers that present in more cosmetic areas such as the face due to the fact that Mohs microsurgery produces less scarring. SEE ALSO: Psoriasis; Skin Diseases (General). BIBLIOGRAPHY. Tracie Egan, Skin Cancer: Current And
Emerging Trends in Detection And Treatment (Cancer and Modern Science) (Rosen Central, 2005); Catherine M. Poole and IV DuPont Guerry, Melanoma: Prevention, Detection, and Treatment, 2nd. ed. (Yale University Press, 2005); Darrell Rigel, et al., Cancer of the Skin (Saunders, 2004); Danielle M. White, Only Skin Deep?: An Essential Guide to Effective Skin Cancer Programs and Resources (iUniverse, 2007). Robert Joshua Basseri Navid Ezra David Geffen School of Medicine at UCLA
Skin Diseases (General) With the advancement of technology and research, a large number of medications and treatments are
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available for individuals who turn to healthcare professionals because of what they believe are a minor abnormality of their skin. It is therefore no surprise that some individuals perceive many skin diseases not as maladies, but as curable disorders that pose little threat to good health and well being. Yet, such diseases are often more than an abnormality of the skin. Those affected may experience emotional distress, a type of discomfort that cannot simply be cured by the application of a topical cream or ointment. What is often unrealized is that skin diseases, also referred to as dermatological diseases, can leave a mark far deeper than that in which can be perceived. Understanding the effects, both physical and emotional, and epidemiology of skin diseases will further provide individuals with a great assessment tool in determining the intensity and prevalence of these diseases. Leukodermia, commonly referred to as vitiligo, is a type of skin condition that causes a loss of pigment in various areas of the skin. In addition to causing pale patches to form across the skin, it has been reported to have caused depression in a number of individuals. Vitiligo appears to especially have a psychological impact on darker skinned patients, since the contrast of pigment is more apparent on their skin. Corticosteroid cream is generally provided for patients as a treatment option. However, alternative treatments are available as well as various support organizations to help patients find the treatment option they feel is most suitable for their condition. Psoriasis is another disorder that has caused psychological distress in individuals. In contrast from vitiligo, psoriasis causes the formation of plaques across the skin that appear red and scaly. The red patches may be localized in a particular area or they may cover the body completely. In an article about psoriasis, Dr. Jarvis noted that the stigmatization experienced by individuals with psoriasis is greater than that experienced by those affected by other skin diseases. As a result, Dr. Jarvis further wrote of the importance for health professionals to consider the social and psychological impact of psoriasis, in addition to the physical symptoms, when caring for patients. It is essential to recognize that diseases of the skin can affect individuals on a level that may be far more personal than otherwise expected. Hence, skin
1552 Skin Diseases (General)
There are certain skin diseases that are actual manifestations of internal disease as opposed to being isolated conditions.
diseases are an issue that should be approached with great care and expertise. Consequences of Unprotected Skin Exposure As the largest organ of the human body, the skin is something that should not be taken for granted. The skin is composed of the epidermis, dermis, and the hypodermis, which is also referred to as the basement membrane. Overall, the skin provides us with protection and takes part in the regulation of our body temperature. Since the skin is the key contributor of the outer covering of our bodies, it is prone to damage through exposure of radiation, bacteria, and sunlight. The severity of impact of the exposure of ultraviolet radiation, whether natural or artificial, is partly dependent on the degree of melanin pigmentation. Melanin is responsible for absorbing some of the ultraviolet radiation that humans come in contact with, through sunlight, on a daily basis. Those individuals with higher concentrations of melanin are able to inhibit light absorption to a greater extent and thus protect themselves more than those individuals with lower concentrations of melanin. However, regardless of melanin concentration, all individuals are vulnerable to the exposure of ultraviolet radiation to
some degree. Tans and sunburns are the most common effects of ultraviolet radiation from sunlight. By monitoring these effects, individuals can learn to limit unnecessary sunlight exposure to their skin so as to prevent themselves from becoming victims of more serious effects such as skin cancer. By following simple measures such as wearing protective clothing and using sunscreen, individuals can in fact avoid great skin damage. Nonetheless, sunlight is not the only source that can potentially cause skin disease. According to Dr. Peate, skin diseases account for approximately 50 percent of occupational injuries. He further proposed that the most common type of occupational skin disorder is contact dermatitis. Contact dermatitis is essentially a skin reaction that occurs as a result of exposure to some type of an irritant. In his article, Dr. Peate points out that some of the industries that are responsible for placing workers at high risk for occupational skin disease are forestry, food production, manufacturing, and construction. Thus, it is necessary for those workers at highest risk to be most precautious. Any and all outbreaks of skin disease amongst workers, whether acute or chronic, should be questioned and reported. In order to keep a safe working environment, it is essential that individuals seek immediate medical attention if any unusual skin conditions develop. Recognizing the prevalence of skin diseases associated with certain working environments is the first step toward decreasing the number of occupational injuries that occur annually. Genetic Skin Disease While skin diseases associated with various occupations are preventable, there are a number of other skin diseases that are not. This is the case for those skin diseases that are genetic. It is for this reason that the field of genetics is becoming a critical area of study in skin research. Albinism is an example of a genetic disease that can cause a form of skin disorder. A disease such as albinism is characterized by the lack of melanin pigmentation in skin as well as in eyes and hair. About one in 17,000 individuals have some type of albinism. This particular disorder is classified as being autosomal recessive and is therefore passed on by individuals who are carriers of the recessive trait. As previously mentioned, albinism is genetic and so it is not infectious and thus cannot be transmit-
ted through any means of contact. In view of the fact that there is no treatment that can replace the lack of melanin in the skin of individuals with albinism, those diagnosed with the disease should protect themselves from excess sunlight exposure so as to prevent additional risk of skin cancer. Other Causes of Skin Disease There have also been studies that have revealed the onset of certain skin diseases to be a result of contaminated food. Various journal articles written by researchers from Taiwan have reported that the first incident of an unusual skin disease caused by contamination of rice oil by polychlorinated biphenyls (PCB) occurred in Japan in 1968. A second incident was found to have occurred in Taiwan over a decade later. After conducting years of studies, researchers today have become better educated on the effects of PCB poisoning and have further gained additional insight on how certain skin diseases can develop. However, the developments of some skin diseases are more complex than others. There are certain skin diseases that are actual manifestations of internal disease as opposed to being isolated conditions. Pyoderma gangrenosum, a gastrointestinal disease found in patients with inflammatory bowel disease, is one example of a disease in which causes a skin condition to develop. Another example is dermatomyositis. As stated in the Merck Manual for healthcare professionals, dermatomyositis is associated with ovarian, gastrointestinal, breast and lung cancers in a large number of individuals diagnosed with the disease. It is therefore believed that the pink patches found on the knuckles of individuals inflicted with this disease may in fact be due to manifestations of cancer. Contagious Fungal Infections It is evident that skin diseases cover a range of conditions which may be benign or fatal. Yet, a surprising and frightening aspect of some infectious skin diseases is that they can be spread by individuals who are asymptomatic. Ringworm is one type of fungal infection of the skin that can be contracted through skin contact by infected individuals even before their symptoms become apparent. A more generic term for a fungal infection that is associated with the skin, such as ringworm, is dermatophytosis. This type of an infection may come from the soil or be spread from
Skin Diseases (General)
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contact with other individuals and even animals. Regardless of what the name implies, ringworm is not associated with an actual worm. It does however appear to look like a ring through the formation of a brown or red raised patch of skin. The infection is generally treated through use of topical antifungal drugs. Athlete’s foot is another example of a skin fungal infection. It can be spread to other individuals and even to other areas of the body. Conventional treatments for this type of infection similarly include the use of topical agents. Appropriate hygiene measures are also a necessary step for prevention and treatment of this infection. Global Skin Diseases and Public Awareness While it is true that some skin diseases may be more prevalent in one population or region over another, there are a number of those that are widespread. According to Dr. Binder and Dr. Sciammarella, one type of skin disease that is common to the global community is scabies. They reported that there are roughly 300 million cases of individuals infected by scabies worldwide each year. Thus, scabies is not a disease to be taken lightly. Scabies is caused by a mite and it produces uncomfortable rashes on the skin. Its global effect is due to the ease of its method of infection. It can be spread through skin-to-skin contact with an infected person as well as by contact with infected clothing or bedding. The difficulty of prevention of such a disease is also attributed to the delayed diagnosis of individuals who are infected. It can take up to six weeks for an individual to be symptomatic. Thus, an individual can be contagious prior to knowing that he or she is infected. Leishmania is yet another global skin disease. It causes atypical skin scarring and may have a high mortality rate if untreated. This worldwide disease is transmitted to the human population through the bite of a particular sandfly. As a part of his theory, Jamal Al-Najjar stated that the only form of elimination of the disease is by means of medication, which is only effective for individuals who have already been infected, as well as by means of public awareness of the transmission cycle of the parasite. Leishmania combat projects continue to conduct eradication campaigns today so as to reduce if not completely eliminate this endemic disease.
1554 Skin Pigmentation Disorders In order to minimize the growing problem of skin diseases, individuals need to work together as a community. Public awareness is the key to better health. As a result of understanding the ambiguous nature of skin diseases, new and effective treatments can be provided for all populations of individuals. However, effective treatments can only be provided if both clinical measurements as well as psychological analyses are considered during diagnoses. Through extensive research and epidemiological studies, the solutions to many of the questions regarding the causes and disparities of various skin diseases can be provided. Yet, it is important to note that even a general understanding and awareness of the risks of skin diseases is a step that can help in the improvement of the health of individuals as well as the quality of their lives on a global scale. SEE ALSO: Psoriasis; Skin Cancer; Skin Pigmentation Dis-
orders; Vitiligo.
BIBLIOGRAPHY. Jamal Al-Najjar, “Efforts Needed to Erad-
icate Leishmania in Yemen,” Yemen Times (April 2007); William Binder and Joseph Sciammarella, “Scabies,” www. emedicine.com (cited June 2006); Sarah Jarvis, Psoriasis: More than Skin Deep (Red Door Communications, 2004); Merck Manual, “Skin Manifestations of Internal Disease,” www.merck.com (cited November 2005); W.F. Peate, “Occupational Skin Disease,” American Family Physician (September 2002); SHARP, “Occupational Skin Disorders,” www.wa.gov/lni/sharp (cited June 1998). Tiffany Tatevossian Navid Ezra David Geffen School of Medicine at UCLA
Skin Pigmentation Disorders Skin pigmentation disorders, while rarely life-threatening, can be alarming and discomfiting for patients given their visible nature. They are generally divided into two categories: disorders of hypopigmentation, where affected skin is lighter than surrounding skin, and disorders of hyperpigmentation, where affected skin is darker. The causes of skin pigmentation changes range from inherited to external factors. As a result, treatment options also vary.
Skin shade is mainly determined by the amount of melanin, a brown pigment. Melanocytes are special skin cells that produce melanin and transfer it to keratinocytes, the main skin cells. Anything affecting the number of melanocytes or melanin production by melanocytes will cause changes in skin pigmentation. The skin becomes lighter when there is less melanin overall, and the skin becomes darker there is more melanin overall. Disorders of hypopigmentation Vitiligo is a common disorder of hypopigmentation where melanocytes are destroyed. It affects approximately 1 percent of the population. There are different theories about the exact mechanism of this destruction; for example, autoimmune attacks against melanocytes may be involved. Genetics may also play a role. Treatment involves stimulating any remaining melanocytes to proliferate, and various strategies such as corticosteroids and ultraviolet light therapy are available. Commercial cosmetics may be used to dye the skin. Alternatively, individuals with extensive hypopigmentation may opt to bleach the remaining dark areas of the skin. Sun protection is important in this case to minimize the risk of future skin cancers. Albinism is a genetic disorder involving the tyrosine kinase gene. Tyrosine kinase is an enzyme involved in the production of melanin. A defect in this enzyme means that there is no melanin production. There are several types of albinism; overall, individuals with albinism have lighter skin, hair, and eyes than is expected and are more susceptible to skin cancer. There is currently no cure for albinism, but using sun protection can help prevent skin cancer. Hypopigmentation can also occur in systemic disorders such as tuberous sclerosis; with tinea versicolor, a superficial fungal infection; or after the skin becomes inflamed, which is called post-inflammatory hypopigmentation. In the latter two cases, the hypopigmentation usually resolves with time once the underlying infection or inflammation has been cleared. Disorders of hyperpigmentation Melasma is an acquired, benign hyperpigmentation of the face and neck. It commonly occurs with pregnancy or with the use of hormonal contraceptives. The cause is unknown, but there appears to be a ge-
Sleep Disorders
netic predisposition in affected individuals. It may resolve spontaneously, but there are chemical creams that can help lighten the affected skin. As sunlight can worsen discoloration, sun protection is also recommended. Concealing agents, lasers, and chemical peels are other options. A nevus, or a mole, is a common example of hyperpigmentation. Nevi are benign growths made of collections of melanocytes. Uncommonly, the melanocytes in nevi do not develop normally, but instead become atypical. Having many nevi with atypical melanocytes is a risk factor for malignant melanoma, the cancer of melanocytes. Nevi should be monitored for irregularities or changes and biopsied if needed. Freckles, or ephelides, are harmless dark spots commonly seen in young, fairer individuals. They darken with sun exposure and fade without it. Sun protection will decrease exposure to the ultraviolet light that leads to increased melanin in the skin and darker freckles. Solar lentigines, or liver spots, occur after long-term sun exposure in older individuals. They do not fade or darken cyclically the way freckles do. Lasers and chemical compounds, such as hydroquinone and tretinoin, can improve the cosmetic appearance of these lesions. Inflammation of the skin can lead to hyperpigmentation, especially in individuals with darker skin. This is called post-inflammatory hyperpigmentation, and can happen after acne, eczema, or trauma. The dark lesions will eventually disappear; chemicals can again be used to hasten this process. SEE ALSO: Eczema; Fungal Infections; Melanoma; Skin
Cancer; Tuberous Sclerosis; Vitiligo.
BIBLIOGRAPHY. Thomas P. Habif, Clinical Dermatology:
A Color Guide to Diagnosis and Therapy (Mosby, 2003); Vinay Kumar, et al., Robbins & Cotran Pathologic Basis of Disease, 7th ed. (Saunders, 2004). Ikue Shimizu Brown Medical School
Sleep Disorders In the United States alone, approximately 40 million people suffer from sleep disorders and do not receive
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the minimum eight hours sleep every night. Many reasons can give rise to improper sleep such as stress, light or television noise, jet lag, temperature fluctuations, traffic noise, alcohol consumption, a sick child, or late-night work. If such instances occur once in a while, then sleeping problems are not harmful and might be temporary and will last only for a short period of time. However, if such cases continue to occur for a prolonged period of time, they might give rise to sleep problems. Insomnia, sleepiness during day, narcolepsy, sleep apnea, sleep walking, snoring, restless leg syndrome, and parasomnia are only few examples of many sleep syndromes. Suffering from such sleep disorders may lead to a potential threat for developing associated health problems in the long run. It can also worsen alreadypresent medical problems such diabetes and hypertension in addition to lowering a person’s energy level. Insomnia Insomnia is the third most common health problem reported and is easily characterized by observing few symptoms. In general, a person can be diagnosed for insomnia when he or she experiences difficulty falling asleep, getting up early or waking up, and then going back to bed. However, many other reasons such as stress, working late hours, back pain, or medicines can result into similar symptoms. It is therefore unwise to make any conclusions prior to consulting a physician. Observe the symptoms at first rather than worrying and be concerned only if they continue upsetting your daily activities. Nonetheless, if these symptoms last for a longer time, they can give rise to chronic insomnia. When you have difficulty falling asleep for most nights, weeks, or over a month, a physician should be contacted. Depending on the individual case, doctors usually advice their patients to change routine habits in addition of taking prescribed medications. Medicines that are used to cure insomnia are drugs that promote sleep function by working with the brain. Studies also suggest that it is most advisable to follow a routine for going to bed and getting up at the same time every day. This is the most effective method of healing from sleep problems because the human brain can recognize a pattern known as the circadian rhythm or a sleep–wake cycle. Hence, the majority of patients are cured or they benefit by following this
1556 Sleep Disorders patients also suffer from some type of mood disorder. Depression, anxiety, and schizophrenia are examples of psychiatric conditions that may lead to insomnia. Even then, one should not link insomnia with psychiatric disorders before ruling out other possibilities.
Suffering from sleep disorders may lead to a potential threat for developing associated health problems over time.
treatment schedule which involves both psychological and pharmacological approach simultaneously. Moreover, to get a better night’s sleep, one should avoid or discontinue the consumption of products containing caffeine, alcohol, or nicotine few hours before bedtime. It is also recommended to keep away from engaging in exercise or related physical activities two hours before bedtime because it creates hindrance for good sleep. On the other hand, stress-relieving exercises such as meditation or yoga might prove to be helpful. In general, insomnia is seen to be more common in older women suffering from depression. The 60-and-over age group is most susceptible to developing insomnia compared to other age groups. Chronic insomnia patients may have faster heartbeat at night and are at higher risk of mortality. Also, they might be functioning at a higher level of cognitive behavior due to faster brain waves at night. Although not completely verified, many support the idea that insomnia is a psychiatric illness. This correlation has formed a foundation on the basis that most insomnia
Sleep Apnea In sleep apnea syndrome, a person usually feels sleepiness during the day and suffers from loud snoring with intermittent breaks between breathing. It is a common, yet dangerous, type of disorder because a person stops breathing while asleep. Such an event may last for 10 seconds or longer and reduce the oxygen supply to blood and the brain. It may occur for anywhere between 100 to 300 times every night, diminishing oxygen levels with rising carbon dioxide in the blood. Occasionally, patients might wake up to breathe. However, there is a risk of death if the person fails to wake up. Sleep apnea is often due to temporary obstruction in the upper respiratory tract. It can also occur due to improper functioning of the brain control centers that regulate breathing (medulla oblongata). Common symptoms for sleep apnea include loud snoring with intermittent gasping, choking, or stress awakening a person to breathe. People suffering from this disorder are usually overweight. Men are more at risk to suffer from this illness than women. A person might experience headaches, lower level of mental activity, and sleepiness during day. It may also jeopardize the patient’s health through diseases that can compromise cardiovascular (heart) and pulmonary (lung) system of a patient’s body. It is highly recommended that the patient loses weight if needed, should not engage in alcohol or nicotine consumption, and should not intake sedatives (sleeping medicines). Changes in such everyday activities have turned out to be the most feasible form of treatment for patients with upper airway blockage. On the other hand, error at the level of the brain in sleep apnea syndrome can be corrected by using an artificial breathing device. This device helps in reducing snoring and should be worn by the patient while asleep. Another kind of device, known as CPAP (continuous positive airway pressure), is used for severe cases of sleep apnea. It basically delivers underpressured air via the nose and keeps the airway open, thereby regulating a stable breathing rate. To control
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snoring, one can try using nasal strips that are available over the counter. If this does not help, one can also try sleeping on one’s side instead of sleeping on one’s back. Sleepwalking Although considered very common and often not taken seriously, sleepwalking is a very risky disorder. Despite being asleep, people who sleepwalk can sit, talk, dress, eat, or even engage in violent activities. This kind of activity at an unconscious level could be dangerous because one is always at risk of getting hurt from serious accidents. Moreover, they also threaten the safety of other people whom the patient might hurt unknowingly. Contrary to the widely accepted idea, waking up a person during sleepwalk is actually safe. Narcolepsy Narcolepsy is a chronic condition due to an irregular sleep—wake pattern (circadian rhythm) functioned by the brain. About one in 2,000 people suffers from narcolepsy. It has no age- or sex-based dimension and, hence, affects everyone equally. It is a neurological disorder in which the patient experiences excessive sleepiness during the day. Falling asleep inappropriately is commonly seen in narcolepsy patients. What specifically causes narcolepsy is unknown; additional symptoms include hallucinations, sleep paralytic effect causing brief periods of immobility, and loss of voluntary muscle tone. A complete loss of muscle tone results in collapsing of the body and gives rise to a condition known as cataplexy. Some people may continue their everyday activities while asleep or without complete consciousness. The symptoms indicate the involvement of neurological dysfunction leading to disturbances in the order and length of the usual sleep–wake cycle. It is also a disease related to family history, depression, and other psychological disorders. Moreover, it usually takes a longer period before the disease is diagnosed from the time of initial onset of symptoms. Getting Better Sleep In general, getting better sleep is the first step to avoid any form of sleeping disorder. Following a set routine with some changes in everyday habits and activities is most helpful. For instance, do not consume substanc-
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es such as caffeine and alcohol a few hours before bedtime. Also, try to avoid engaging in physical activity, watching television, or listening to music right before bedtime. Limit napping during the day to get a proper night’s sleep. If you are still having trouble, then participate in relaxing activities such as meditation and yoga. SEE ALSO: Back Pain; Headache and Migraine; Psychiatrist; Restless Legs; Stress. BIBLIOGRAPHY. American Medical Association Family
Medical Guide, 4th ed. (Wiley, 2004); “About: Sleep Disorders,” www.sleepdisorders.about.com (cited January 2007); Max Hirshkowitz and Patricia B. Smith, Sleep Disorders for Dummies (Wiley, 2007); Martin S. Lipsky, ed., American Medical Association: Concise Medical Encyclopedia (Random House Reference, 2007); National Institute of Neurological Disorders and Stroke, “NINDS Narcolepsy Information Page,” www.ninds.nih.gov/disorders/narcolepsy/narcolepsy.htm (cited January 2007); National Jewish Medical and Research Center, “About Sleep Disorders,” www.nationaljewish.org/disease-info/diseases/sleep/ about/index.aspx (cited January 2007); Maxine A. Papadakis and Stephen J. McPhee, Current Consult Medicine (McGraw-Hill, 2007); U.S. Food and Drug Administration: Office of Women’s Health, “Take Time to Care: Sleep Disorders,” www.fda.gov/womens/getthefacts/sleep.html (cited January 2007). Jinal Mehta University of Missouri
Slovakia In January 1993, the Slovaks and Czechs agreed to peacefully separate into the sovereign nations of the Slovak and Czech Republics. The Slovak Republic subsequently became one of the success stories among the nations that had formed the Soviet bloc. With a current growth rate of six percent, the Slovak economy is strong. Privatization is almost complete, and foreign investors are deeply involved in the country, particularly in the banking sector. While inflation (2.7 percent) is under control, unemployment (16.4) continues to be a major concern. With a per capita income of $16,300,
1558 Slovakia Slovakia ranks 63rd in world incomes. Some income disparity does exist, and the richest ten percent of the population controls 20.9 percent of wealth as opposed to 3.1 percent for the poorest ten percent. After social transfers, over a fifth of the population is still at risk for living below the poverty line. The UNDP Human Development Reports rank Slovakia 42nd in overall quality of life issues. The Slovak government spends a fifth of the total budget on health. Approximately ten percent of the Gross Domestic Product (GDP) is used to fund health programs, with $777 (international dollars) allotted per capita. The government bears the responsibility for 88.3 percent of all health spending, and 93.5 percent of government funds are earmarked for social security. Through out-of-pocket expenses, the private sector provides 11.7 percent of total health funding. There are 3.18 physicians, 6.77 nurses, 0.27 midwives, 0.44 dentists, and 0.52 pharmacists per 1,000 population in Slovakia. In Slovakia, health workers are paid considerably less than in the Czech Republic. Consequently, many Slovak medical professionals are filling gaps left by the flight of Czech doctors to more lucrative positions elsewhere in Europe. At least 700 Slovak physicians have already made the move to the Czech Republic, and others are leaving at the rate of 30 per month. There is great concern that in the future both countries may face a shortage of doctors if Slovaks follow Czechs into better paying positions. Some hospitals have begun to offer various enticements in an attempt to circumvent the potential shortage. After a period of stagnation in healthcare between the late 1960s and the late 1980s, major reforms were instituted to improve health and to generate financing for health-related programs. Since 1991, residents have been able to choose private healthcare over that offered by the government. Despite the reforms, problems still exist; and policies are not always clearly defined, resulting in confusion and lack of coverage. In 2005, a new social insurance system was instituted, financed by mandatory contributions from workers and the self-employed. Set percentages of those contributions are earmarked for old age and disability pensions and for individual accounts that are used to fund social programs. Workers contribute seven percent of earnings,
and another 26 percent is generated from voluntary contributors. Self-employed individuals contribute 26 percent of earnings, and employers are required to submit 19 percent of payroll. Government funding provides 26 percent of the social insurance fund. Cash benefits are paid to ill workers and new mothers. All families also receive cash allowances, regardless of income. The population of 5,439,448 experiences a life expectancy of 74.73 years, with females outliving males by an average of eight years. Literacy (99.6) is virtually universal in the Slovak Republic. Primary school enrollment stands at 86 percent, and 88 percent of the relevant population regularly attends secondary school. All Slovaks have access to safe drinking water and improved sanitation. Nearly a quarter of Slovak women use birth control, and Slovakia has the 14th lowest fertility in the world, with women giving birth at a rate of 1.33 children each. Only one percent of births take place outside the presence of trained attendants, and the adjusted maternal mortality ratio is one of the lowest in the world (three deaths per 100,000 live births). Between 1990 and 2004, infant mortality was halved, dropping from 12 to six deaths per 1,000 live births. At the same time, the mortality rate of children under the age of five fell from 14 to nine deaths per 1,000 live births. Infant mortality is currently reported at 7.26 deaths per 1,000 live births. Seven percent of all Slovak children are underweight at birth. The government finances 80 percent of required infant vaccinations, and rates are consequently high. Only one percent of infants fail to be immunized against diphtheria, pertussis, and tetanus (DPT1 and DPT3), polio, Hepatitis B, and Haemophilus influenzae type B; and only 2 percent do not receive vaccinations against tuberculosis and measles. The Slovak Republic has an HIV/AIDS adult prevalence rate of less than 0.1 percent. The Slovaks have the 11th lowest rate of people living with this disease worldwide (less than 200), and less than a hundred have died from HIV/AIDS-related illnesses. The people who live in areas surrounding metallurgical plants are facing health risks from polluted air. The leading causes of death in Slovakia are cardiovascular disease, cancer, and accidents. See Also: Birth Rate; Healthcare, Europe.
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BIBLIOGRAPHY. Central Intelligence Agency, “Slovakia,”
World Factbook, www.cia.gov/cia/publications/factbook/ geos/lo.html (cited May 2007); Commission on the Status of Women, “Slovakia,” www.un.org/womenwatch/daw/ Review/responses/SLOVAKIA-English.pdf (cited May 2007); Martin A. Levin and Martin Shapiro, eds., Transatlantic Policymaking in an Age of Austerity: Diversity and Drift (Georgetown University Press, 2004); Martina Mareckova, “Exodus of Czech Doctors Leaves Gaps in Health Care,” The Lancet (May 1, 2004); Social Security Administration, “Slovak Republic,” www.ssa.gov/policy/docs/progdesc/ ssptw/2004-2005/europe/slovakrepublic.html (cited May 2007); UNICEF, “Slovakia” www.unicef.org/infobycountry/ slovakia_statistics.html (cited May 2007); World Bank, “Slovakia Republic Data Profile,” http://devdata.worldbank.org/ external/CPProfile.asp?PTYPE=CP&CCODE=SVK (cited May 2007); World Health Organization, “Highlights on Health in Slovakia” http://ec.europa.eu/health/ph_projects/1999/monitoring/slovakia_en.pdf (cited May 2007); World Health Organization, “Slovakia” www.who.int/countries/svk/en/ (cited May 2007). Elizabeth R. Purdy, Ph.D. Independent Scholar
Slovenia This central European country was a part of the Austro-Hungarian Empire until World War I, after which it became a part of what became the Kingdom of Yugoslavia. In 1991 it gained its independence as the Republic of Slovenia, with its capital and largest city being Ljubljana. The health services during the period of the AustroHungarian Empire were relatively good in Ljubljana, but undeveloped in the nearby countryside. The effects of World War I led to the Kingdom of Yugoslavia having little money to spend on improving the medical services during the 1920s. The result was that Yugoslavia had the highest death rates from tuberculosis, with diphtheria, dysentery, malaria, syphilis, typhus and whooping cough relatively common. In 1934 King Peter II of Yugoslavia drew up plans to improve the healthcare system within the whole of Yugoslavia, with the Regional Institute for Research and Treatment of Neoplasms was established by Royal Decree in 1937.
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On August 1, 1938 the Regional Institute admitted its first cancer patients in what had been the Sempeter Barracks in Ljubljana. At that time it had 28 beds, dealing with 818 outpatients. In 1946, the Regional Institute was renamed the Institute of Oncology. The establishment of the Tito government in Yugoslavia in 1944 led to many changes in the provision of health care, with the Yugoslav Red Cross, which covered Slovenia, being established in 1944, and the Cancer Registry of Slovenia established soon afterwards. The health services for the entire country were nationalized, and from the 1950s the administration of these were decentralized, leading to most of the Slovenian healthcare system being run from Ljubljana. There were some budgetary problems in the 1970s and early 1980s, leading to the emergence of a private sector with doctors and dentists being able to treat patients for payment. Although this was illegal, the government tolerated it as it reduced the stress on the government medical system. The Institute of Medical Sciences at ZRC SAZU was established in 1987, and there were medical faculties at the University of Ljubljana and the University of Maribor. After independence in 1991, there were only 70 doctors and 180 other specialists (including dentists) for every 100,000 people. However it did have a very good healthcare infrastructure with 27 hospitals which had 12,000 beds in total, and forty regional health centers. There are now health centers in every city in the country, with clinics open from 7 a.m. until 7 p.m. each day, with many pharmacies around Slovenia. Tap water is safe throughout the country, with some coastal regions being over-chlorinated. There are increasing cases of hepatitis and HIV/AIDS, In 1983 there were 230 doctors for every 100,000 people in the country, and one bed for every 128 people in Slovenia. In 2006, with a population of 2,004,000, Slovenia had 228 doctors and 681 nurses per 100,000 people. In 1990, some 99.7 percent of all births in the country were attended by a medical health professional. Slovenia also provides free healthcare to foreign citizens from many countries including Germany, Italy and the United Kingdom. SEE ALSO: AIDS; Cancer (General); Healthcare, Europe. BIBLIOGRAPHY. R.G. Dyck, “Health Care Planning in
Slovenia,” Papers in Slovene Studies (1977); Institute of
1560 Small Intestine Cancer Oncology, Ljubljana, www.onko-i.si/en (cited November 2006); “Onkoloski Institut,” Cancer Bulletin (v. 11, November-December 1959); Leopoldina Plut-Pregelj and Carole Rogel, Historical Dictionary of Slovenia (The Scarecrow Press Inc., 1996). Justin Corfield Geelong Grammar School, Australia
Small Intestine Cancer Small bowel cancers represent a relatively small portion of the 1,399,790 estimated new occurrences of cancer in 2006. Of this estimate, 6,170 will be attributable to the disease. Of course, not all neoplasias (tumors) of the small intestine are cancerous. It is interesting to note that the small intestine (six meters or six and one-half yards in length) is 75 percent of the length of the gastrointestinal tract and yet small intestine (also called small bowel) malignancies represent only 2 percent of the cancers of the gastrointestinal tract. The reason for the difference in the occurrence of cancers in the small intestine may rest in the characteristics of the digestive contents. The small intestine contents are liquid causing less irritation as compared to the more solid contents of the large intestine. The small intestine also moves the contents through at a much quicker pace (again as compared to the large intestine) and because of this there is less time for carcinogens which may be ingested or manufactured by intestinal bacteria to be in contact with the mucosal lining. The bacterial load of the small intestine is much lower than that of the large intestine thus minimizing the above noted intra-luminal production of cancer causing agents. Also, there is a great deal of lymphoid tissue in the small intestine as compared to the large intestine and the defensive nature of lymph tissue may offer protection against cancers of the small intestine. The etiology of small bowel cancer is not clear. Again, comparing the small and large bowel, the transformation from adenomas (polyps with glandlike structure) to cancer is similar. Part of the problem with making an early diagnosis is that because the
small intestine contents are liquid, polyps can grow, degenerate into malignant tumors, and spread to other areas of the body before any type of obstruction occurs, the liquid simply squirting past the growing tumor. In contrast, the large bowel, especially the descending bowel, processes solid stool and a growing polyp/tumor causes early obstruction. Risk factors for developing small bowel carcinoma include smoking, excessive alcohol intake, dietary habits (consuming chemicals called heterocyclic amines from fried bacon, ham, and smoked meat and fish). The patient with small bowel carcinoma presents with vague symptoms that can be attributable to many other benign causes, such as dumping syndrome (improperly digested foods reaching the end of the small intestine); irritable bowel syndrome (characterized by hypermotility); lactose intolerance (inability to digest natural sugar found in milk); and acid peptic disease of the upper GI tract. Patients with small bowel neoplasias, malignant or non-malignant, complain of diarrhea, dark colored (“digested blood”) stools, bloody stools, cramping abdominal pain, weight loss, anemia or jaundice (yellow color of the skin) if the tumor is near the bile duct openings in the duodenum and causes a blockage to flow of the bile. Frequently, the diagnosis of small bowel neoplasias is delayed for many months due to the patient not realizing that the symptoms are due to a tumor. Without a high level of suspicion on the part of the physician, more extensive tests may not be ordered early in the work up of the patient since symptoms are vague, overlap with other treatable conditions, and tend to lessen periodically without intervention. It is stated that because of the above manifestation of small bowel cancer, 50 percent of the patients who do present have metastasis (spread outside the small bowel) at the time of their first visit to the doctor. There are three large regions of the small intestine. These are the duodenum (upper-most and the shortest section); the jejunum (just past the duodenum and approximately 40 inches or 100 centimeters in length); and the ileum (the final portion and approximately 240 inches or 600 centimeters in length). There are four (4) main types of small bowel cancer and these are: adenocarcinoma, more likely to involve the duodenum; sarcoma and carcinoid, more likely to affect the ileum; and lymphoma, generally commencing in the jejunum. The preceding sites of original tumor are
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generalizations, again making the definitive diagnosis before surgery extremely challenging. The clinical diagnosis of small intestine neoplasias requires a complete history and physical examination. The stools are checked for occult blood and a complete blood count and chemistry are performed. X-ray studies of the abdomen including plain x-rays and CT scans and upper GI with small bowel follow through are accomplished. Upper GI with small bowel follow through x-rays are performed by having the patient swallow barium and continuing to take x-rays as the barium courses through the small intestine and this can demonstrate a tumor. An upper GI endoscopy is performed by inserting a long fiberoptic tube down the esophagus, through the stomach and into the duodenum where biopsies (pieces of the abnormal tissue) can be obtained. A longer endoscope can be inserted into 70 percent of the length of the small intestine and can visualize and take biopsies of tissue. A newer technology called wireless capsule endoscopy involves the patient swallowing a small video camera, which sends images wirelessly to a monitor, and then the lining of the small intestine can be visualized. Ultimately, an open abdominal surgical exploration (exploratory laparotomy) and tissue biopsy is required to make the pathological diagnosis of small bowel neoplasia (cancer or non-cancerous) for most patients. Surgery with complete removal of the entire tumor with wide margins of disease-free tissue offers the best chance for survival for most patients. Sometimes this requires that a bag be placed on the abdominal wall and the open end of the ileum is sewn to the inside of the abdominal wall and stool is collected in the external bag (ileostomy). As previously stated, small intestine neoplasias are generally slow to show symptoms and patients usually have metastasis (spread to other locations) at the time of definitive diagnosis. Other treatment includes chemotherapy and radiation therapy either pre-operatively (neoadjuvant) or post-operatively (adjuvant). Unfortunately, neither therapy offers much because of the usual finding of widely metastasized cancer at the time of diagnosis. Research is underway to identify the best combination and use of the three treatments. Early diagnosis remains the best care.
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See Also: Cancer (General; Chemotherapy; Surgery. BIBLIOGRAPHY. American Cancer Society, Cancer Facts and Figures 2006, www.cancer.org, (cited August 2006); James C. Cusack, Jr., M.D., “Diagnosis and Management of Small Bowel Neoplasms,” www.uptodate.com, (cited August 2006); James C. Cusack, Jr., M.D., “Epidemiology, Clinical Features, and Types of Small Bowel Neoplasms,” www. uptodate.com, (cited August 2006); George D. Demetri, M.D. and Jeffrey Morgan, M.D., “Gastrointestinal Stromal Tumors, Leimyomas, and Leiomyosarcomas of the Gastrointestinal Tract,” www.uptodate.com (cited August 2006); P. Drastich, “Capsule Endoscopy—Past, Presence (sic), and Future,” Cas Lek Cesk (2006); O. Ersoy, et al., “How Much Helpful (sic) is the Capsule Endoscopy for the Diagnosis of Small BowelN,” World J. Gastroenterology (June 28, 2006); M.K. Liu, et. al, “Application of Capsule Endoscopy in Small Intestine Diseases: Analysis of 28 Cases in Kaohsiung Medical University Hospital,” (sic) Kaohsiung J. Med. Sci. (September 22, 2006); Paul C. Schroy, III, M.D. and Arnold S. Freedman, M.D., “Classification and pathology of gastrointestinal lymphomas,” www.uptodate.com (cited August 2006); Paul C. Schroy, III, M.D. and Arnold S. Freedman, M.D., “Clinical Presentation and Diagnosis of GastrointestinalL,” www.uptodate.com, (cited August 2006); Neha Vapiwala, M.D., “Cancer of the Small Bowel,” www.oncolink. com (cited October 2006).
Richard K. Ogden, D.O., FACOFP, FAAFP Kansas City University of Medicine and Biosciences
Smallpox The virus Variola major is a poxviridae virus causing pox or pus-filled lesions of the infectious disease smallpox, a lethal and disfiguring disease prevalent throughout history. Smallpox is characterized by an initial high fever and pus-filled blisters leaving deep pitting scars on most of the body. Although not immediately contagious, Variola virus passes from person to person through droplet transmission or by direct contact, skin-to-skin contact with an infected person, and by having the airborne droplets combine with dust and become attached to bedding or clothing after the incubation period. Smallpox
1562 Smallpox has an incubation period of seven to 17 days with an average of 12 days between exposure and illness. The virus embeds in cells close to the surface of the skin and then sheds the protective shell and begins to multiply. The genetic material from the virus begins replication and inserts the genetic information into the host cell. Proteins and enzymes help the virus mature and develop. Smallpox, considered eradicated by the World Health Organization in the late 1970s and therefore unnecessary as standard vaccination any longer, means the disease is unlikely to be contracted from a natural source. However, after the attacks with anthrax, the possibility of using this as a weapon is highly likely. Normally, a person is exposed to the virus Variola major about 12 days before the first symptoms of severe fever, headache, and malaise appear. At this point, even before the development of a rash and pustules, the person is infectious and can pass the virus on to others through droplet transmission just by being in the same room with an infected person. It is highly contagious and hardy enough to remain stable and infectious in a variety of environments. The best treatment results rely on early detection, isolation of infected persons, and focused selective vaccination. Origin and History of Smallpox Virus One of the oldest recorded diseases, smallpox epidemics and the symptoms have been described in written and oral history. Records indicate an epidemic in Africa between 1200–1100 b.c.e. and one the earliest epidemics occurred in China about 1120 b.c.e. with various smaller epidemics occurring later and records purport the spread of smallpox from Indo-China into other parts of China, with Japan and Korea experiencing epidemics later. Smallpox spread rapidly throughout the populated world including Egypt, Arabia, and Greece, and in the 2nd century c.e., it had spread into central Europe. Various skin conditions and epidemics of illness similar to smallpox have been recorded throughout history and in various parts of the world. Roman physicians described an epidemic similar to smallpox in the 2nd century. The spread of the disease into the Near East is a topic of controversy as far as timing, although a perhaps later account is recorded in the 10th century. From the 2nd century onward, smallpox spread throughout Europe. As travel and trade increased and
ships traveled greater distances across the oceans, the islands in the Atlantic including Iceland, Greenland, and the Faroe Islands were infected. After the arrival of the Europeans, North, Central, and South American indigenous people succumbed to smallpox, with many epidemics among the North American Indians. Whole tribes were destroyed, even those individuals who had been considered strong and healthy. Europeans may have found the New World easier to conquer as more of the indigenous people died from infection. In the later expansion of the Europeans westward in North America, some historians contend smallpox may have been spread intentionally with contaminated blankets. The last case of smallpox in the United States occurred in 1949. In 1977, the last case worldwide was reported in Somalia. By the mid-1980s, vaccination for smallpox ceased and the success of vaccination touted for eradicating the disease. Diagnosis, Signs, Symptoms and Treatment Smallpox is a serious disease that might be initially confused with chickenpox. The severe symptoms occur early in the disease state; during the prodromal phase of smallpox, the infected person will experience a high fever along with severe headache and backache. The infectious phase includes enanthem, followed by skin eruptions. The lesions may appear on the face, neck, trunk, and extremities. The lesions begin as macules, continue to papules, and then to pustules before crusting over within 14 to 18 days. Unlike chickenpox where the lesions are in various stages of development throughout the rash phase, smallpox lesions develop at the same time and have a single shape in the various anatomic. The chance of transmission is most common from the beginning formation of the rash until the pustules crust over. With the full-blown disease, deep and disfiguring pox scars remain. Because the disease can be confused with other pox viruses such as chickenpox or shingles, a specific test must be performed to diagnose smallpox. The definitive diagnostic test is the Direct Fluorescent-Antibody reaction. Variola antibodies labeled with fluorescent dye are combined with the antigen (suspected Variola virus) from a patient’s blood on a slide and incubated. The slide is washed to remove excess antibodies and then viewed under an ultraviolet light/fluorescence
microscope; if the result is positive, the slide fluoresces. The test must be performed in a specialized lab with protective gear and procedures in place. No current antivirals are effective against smallpox. Having the smallpox infection provides lifelong immunity, whereas the Vaccinia virus vaccination for smallpox provides a shorter-term immunity with a somewhat lasting protection from experiencing severe illness or having a milder form of smallpox. Protective Inoculation anD Vaccine Development The first vaccination for smallpox may have first been performed in China as early as 1022 bce. The process was called variolation; blisters from a person infected with smallpox were scraped off and the pus was injected into the vein of the person seeking protection from the virus to inoculate those who had not yet had the disease. Variolation relies on having a milder form of the illness and is similar in theory to exposing a child to chickenpox to provide long-term immunity. This practice was used widely throughout the world. Throughout the years and up until the late 17th century, this method was one of the preferred means of protection from death due to smallpox. The information must have been passed down anecdotally as a folk remedy in Europe and taught to practicing physicians. Not until the late 17th century did English physician Edward Jenner notice patients who had smallpox never had smallpox again and that milkmaids who contracted cowpox, a less virulent strain of poxvirus, did not develop the smallpox disease when exposed to the virus. He experimented by taking a scraping from a milkmaid’s cowpox pustule and scratching it into the skin of an 8-year-old boy named James Phipps. The child became mildly ill and when he was later exposed to smallpox, he did not contract the disease. The first immunization was created. In the early 20th century, vaccination with Vaccinia virus grown on bovine calves’ skin became a standard method for preventing the spread of smallpox. As more people in many countries were immunized, the epidemic rates decreased in those areas with the most widespread use of vaccine and slower decrease in epidemics was seen in areas where immunization was not as well carried out. Vaccination programs continued until 1972 in the United States and into the 1980s in other parts of the world. At that time, smallpox was
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considered extinct as a natural disease, no longer capable of causing epidemics. The virus existed only in laboratories and only by accidental release of the virus would any person develop smallpox. After the anthrax attack on government offices and exposure of postal employees in 2001, other viruses and bacteria have been looked at as possible weapons including smallpox. A three-phase immunization program for smallpox was instituted. The first phase included immunization of military personnel and hospital employees. The second phase included allied health professionals and other healthcare workers, and first responders; police, firefighters, and emergency medical technicians were recommended to receive the vaccine. The third phase includes the general public on a voluntary basis. Due to possible adverse reactions of fever, rash, encephalitis, and a low risk of death, the vaccine is not recommended for widespread administration, except in the event of a biological attack. The smallpox vaccine currently in use is made from live Vaccinia virus, the related poxvirus otherwise known as cowpox. The virus is grown in bovine calf lymph tissue. The antigen is then freeze-dried for added stability until just before administration. The vaccine may also contain antibiotics—polymixin B, streptomycin, chlorotetracycline, and neomycin—to prevent contamination. When reconstituted, the vaccine must be used immediately to avoid becoming unstable and changing the structure of the vaccine. 21st Century Vaccination Recommendations The smallpox vaccine is administered intracutaneously with 15 perpendicular strokes in a 5 mm diameter area. The inoculation is similar to a scratch just deep enough to bring blood to the surface of the skin. After inoculation, a bandage is applied to absorb seepage and then a second covering prevents the spread of the virus. Within six to 11 days, the injection site forms a pustule and then scabs over. Normal reactions to the vaccine include lesions in the area of inoculation, arm soreness, and inflammation. Systemic reactions might include fever, muscle aches, headaches, nausea, and fatigue. The live Vaccinia virus is present at the inoculation site and in the lesion until it scabs over with possible transmission to other people.
1564 Smallpox Severe Adverse Effects: Historically, there is about one death per million people vaccinated. Local reactions might include a toxic or allergic rash and bacterial infection at the site of inoculation. Systemic infections are rare and might include generalized development of cowpox or encephalitis. Contraindications: In nonemergency situations, smallpox vaccine is not recommended for administration to children under the age of 18, infants, pregnant or lactating women, or people with immunosupressed conditions (organ transplant recipients, cancer, autoimmune disease, immunodeficiency, those with allergies to the vaccine or ingredients, those with active skin conditions such as burns, varicella, severe acne, and psoriasis) or anyone who lives with a person with any of these conditions.
prevent or lessen the severity of symptoms of smallpox. If administration of smallpox vaccine occurs within four to seven days of exposure, a lesser degree of protection will be seen with some degree of lessening in the severity of symptoms. Public health departments in the United States have stockpiles of smallpox vaccine ready to be shipped to any part of the country where a bioterrorist attack with smallpox virus might take place. For postexposure vaccination to be effective, the stockpile must be large enough to handle a large-scale vaccination program, the distribution must be rapid enough to vaccinate affected individuals within the time frame for the best prognosis, and enough trained personnel must be available to administer the vaccine in a timely manner.
Potential as a Biological Weapon As a global health issue, smallpox may be a twofold threat: first, as proliferation of weapons of mass destruction and second, as a possible agent for use by terrorists for widespread infection as we no longer routinely vaccinate against smallpox and the potential to create an epidemic. With no availability of specific antiviral treatment against smallpox clinically, the effect would be debilitating and with the added psychological symptom of mass panic, the results could be catastrophic. In 1999, the CDC evaluated many biological agents to determine which were the most critical in terms of preparation and availability of educational information to be ready in the event of a biological attack. Smallpox was placed in the greatest threat category for numerous potential victims and need for additional stockpile of vaccine. Smallpox as a weapon is an attractive choice because even with the risk involved, growing the virus is cost-effective, it is small and easily spread, and most important, the results will have a continuous effect over time with person-to-person transmission. While the threat of use of smallpox exists, the probability of use is limited by the difficulty in obtaining and producing the smallpox virus. Those persons who had the smallpox vaccine prior to 1972 have some immunity conferred, enough to make the disease less serious and prevent fatal illness. In the event of exposure to smallpox, the administration of vaccine within three days after exposure will
Global Implications Scientists are concerned that earlier vaccinations did not provide long-term immunity from smallpox with waning immunity after five years and anyone could be at risk for developing smallpox if the virus were to be used as a biological weapon. When the United States discontinued routine smallpox vaccination, health experts considered that they would only have to vaccinate others if they were exposed to someone who had smallpox. The vaccine went into the stockpile of medications and the smallpox virus itself was to be stored legally in two places: the CDC in Atlanta, Georgia, and at the Vektor Institute in Siberia, Soviet Union. With the fall of the Soviet Union, Soviet scientists working in microbiology/virology spread throughout the globe. All of the smallpox virus may not be accounted for and some countries may have laboratory smallpox illegally. The potential threat worldwide for the release of smallpox in a terrorist attack means continued vigilance and preparation in case of a threat. Medical professionals at the local level will be relied upon to detect and report the release of any biological weapons. Since smallpox testing must be done at an approved CDC laboratory, medical professionals must have the knowledge of when to send out the samples for testing and how to prevent the potential spread of the disease Therefore, local healthcare workers and public health departments must have a surveillance program in place and be trained to appropriately handle an emergency small-
Smokeless Tobacco
pox epidemic. In addition, they will need to establish a procedure to notify and educate the public quickly and causing the least panic while coordinating the public health diagnosis, vaccination, and if necessary, isolation and quarantine. The world health community believes that because smallpox has been eradicated, the stocks of smallpox virus remaining in laboratories should be destroyed. With the advent of terrorist attacks around the world, scientists and government entities must consider the importance to public health in retaining the stocks of smallpox virus in storage for use by researchers in developing new vaccines or for testing the effectiveness of antiviral medications. SEE ALSO: Adult Immunization; Biological and Chemical
Weapons; Bioterrorism; Centers for Disease Control and Prevention (CDC); Chickenpox. BIBLIOGRAPHY. Ken Alibeck and Stephen Hundelman,
Biohazard: The Chilling True Story of the Largest Covert Biological Weapons Program in the World—Told from inside by the Man Who Ran It (Random House, 1999); Timothy G. Berger, “Skin, Hair & Nails,” Current Medical Diagnosis and Treatment (Lange Medical Books, 2004); Bill Frist, When Every Moment Counts (Rowman & Littlefield, 2002); Folke Henshen, The History and Geography of Diseases (Delacorte Press, 1962); “Quick Facts about Smallpox Vaccination,” American College of Physicians, www.acponline. org/bioterror (cited June 2007). Lyn Michaud Independent Scholar
Smokeless Tobacco Although most tobacco found in cigarettes, pipes, cigars, or cigarillos involves using fire, there are some tobacco products that are known as “smokeless tobacco,” “dipping tobacco,” “American moist stuff,” and “spit tobacco.” These tobaccos are placed in the mouth and either put under the lip or on the gums, or chewed. Originally, these were often confused with snuff. Smokeless tobacco is commonly used in the United States, and has been particularly popular in workplaces where the worker uses both hands regu-
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larly, and hence cannot use a cigarette safely, or where “smoking” in the workplace is either not allowed on health grounds (as is common in workplaces in many parts of the Western world), or cannot be used on safety grounds, such as in mines where there is a danger from gas pockets or from use of explosives. The main U.S. brands for smokeless tobacco are Copenhagen, Skoal fine cut, and Kodiak, with the tobacco generally sold in round metal tins similar in size to those used for boot polish. There are some smokeless and spitless tobacco products that were marketed by Altria Group Inc. (formerly Phillip Morris Companies) and R. J. Reynolds Tobacco Company, both large-scale producers of cigarettes. It has long been thought that use of smokeless tobacco is far less hazardous than cigarettes. Certainly because there is no smoke, the risk of suffering from lung cancer—the main health factor with smoking cigarettes and similar products—is massively reduced. Some individual products also have the tobacco mixed into a herbal-based composition, with mint leaves, corn silk, and pueraria also used. As a result, it has been highlighted as a safe alternative to smoking cigarettes, but this is not the case. Smokeless tobacco still contains nicotine; use of it remains highly addictive—nicotine being the primary addictive agent. As a result of worries about oral cancer, three warning labels must be used in rotation on all packages of smokeless tobacco sold in the United States: “Warning: This product may cause mouth cancer,” “Warning: This product may cause gum disease and tooth loss,” and “Warning: This product is not a safe alternative to smoking.” Many other countries use these and/or similar warnings, and although individual regulations vary throughout the world, the sale of tobacco—including smokeless tobacco—is generally restricted to adults. SEE ALSO: Smoking; Smoking and Youth; Smoking Cessa-
tion; Smoking and Pregnancy.
BIBLIOGRAPHY. M. Kunze, “Smokeless Tobacco—A Less
Harmful Alternative?” The Tobacco Epidemic (Karger, 1997); Jan Rogozinski, Smokeless Tobacco in the Western World 1550–1950 (Praeger, 1990). Justin Corfield Geelong Grammar School, Australia
1566 Smoking
Smoking Smoking, the most prevalent form of tobacco consumption in the world, is a major preventable cause of premature death and chronic disease. The World Health Organization (WHO) estimates that smoking kills nearly 5 million people every year, accounting for 12 percent of global adult mortality. Both smokers and nonsmokers are at risk—smokers from the direct adverse impact of smoking, and nonsmokers from involuntary exposure to secondhand tobacco smoke. Thus, reducing smoking by helping smokers quit and supporting nonsmokers to remain tobacco-free is a key global health priority. Global Smoking Prevalence While there are various ways to consume tobacco, cigarette smoking is the most widespread. Cigarettes constitute about 96 percent of total tobacco sales worldwide. Half of all cigarettes produced annually are smoked in five countries: China, the United States, the Russian Federation, Japan, and Indonesia. China accounts for about one-third of all cigarettes smoked in the world. Globally, about one in three adults and one in ten youth smoke. Among adults, smoking is significantly higher among men—almost 1 billion men smoke compared to about 250,000 women. Male smoking is higher in the developing world, with prevalence averaging about 50 percent as compared to 35 percent in developed countries. Female smoking is higher in developed countries, although smoking rates among women are increasing in several developing countries. The Global Youth Tobacco Survey (GYTS) reveals that among youth aged 13 to 15, gender differences in smoking are minimal. Over half of the countries surveyed showed no difference between boys and girls smoking. This finding foreshadows increases in adverse reproductive outcomes and tobacco-related deaths among women in the future. Consequently, gendersensitive approaches to reducing smoking, especially among youth, are crucial. The GYTS also confirms that use of other tobacco products is as prevalent as smoking among young people, highlighting the need to address alternate forms of tobacco consumption. Scientific evidence confirms that smoking harms nearly every organ in the body, causing multiple diseases and impairing the health of smokers. The ad-
verse health effects can begin before birth and continue across the life span. The 2004 U.S. Surgeon General’s Report concluded that evidence is sufficient to infer a causal relationship between smoking and the following: • Cancer of the bladder, cervix, esophagus, kidney, larynx, lung, oral cavity, pancreas, stomach, and leukemia • Cardiovascular diseases—abdominal aortic aneurysms, hardening of the arteries, stroke, and coronary heart disease • Respiratory diseases, both acute (pneumonia, acute bronchitis) and chronic (emphysema and chronic bronchitis), and impaired lung function • Other diseases and conditions—peptic ulcer, cataracts, hip fractures, low bone density, and poor wound healing after surgery • Adverse reproductive outcomes for women who smoke during pregnancy, including infertility, premature labor, complicated labor, stillbirth, low birth weight babies, and sudden infant death syndrome (SIDS) • Decreased overall health, manifested as increased absenteeism from work and increased use of medical services Evidence indicates that smoking harms nonsmokers too. According to the 2006 Surgeon General’s Report, infants and children exposed to secondhand smoke are at an increased risk of SIDS, acute lung infections, ear problems, worsening asthma, and impaired lung growth. Adults exposed to secondhand smoke are at higher risk for lung cancer and heart disease. Workplace exposure to secondhand smoke is widespread. The World Bank reports that in 1996, in China, over 130 million adult nonsmokers experienced occupational tobacco smoke exposure. Almost half of youth surveyed by the GYTS reported exposure to secondhand smoke at home, and over 60 percent reported exposure in public places. Recent studies demonstrate the efficacy of smoke-free laws in reducing exposure to secondhand smoke. These findings reinforce the importance of legislative strategies to protect nonsmokers from exposure to cigarette smoke. Smokers initiate and continue cigarette smoking for multiple reasons. Young people start smoking because of curiosity, rebellion, risk taking, role modeling from parents and older siblings who smoke, peer
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Aggressive marketing by the tobacco industry and permissive environments that make cigarettes available, accessible, and affordable induce smoking. Female smoking is higher in developed countries, and smoking rates among women are increasing in developing countries.
pressure, the desire to lose weight, the aspiration to appear grown-up, and the wish to look “cool” and to “fit in.” Aggressive marketing by the tobacco industry and permissive environments that make cigarettes available, accessible, and affordable induce people to take up smoking. However, while smoking initiation is prompted by diverse factors, smoking maintenance is often driven by nicotine addiction. Human and animal studies identify nicotine as the substance in cigarettes that leads to addiction. Nicotine in cigarette smoke is easily absorbed through the lungs, rapidly enters the bloodstream, and quickly reaches the brain. Nicotine reacts with specific brain receptors that cause the release of chemicals, among them dopamine and norepinephrine. Activating some of these receptors causes the pleasurable “rush” that smokers experience with smoking. Other receptors are activated when nicotine levels drop, evoking symptoms that characterize the “withdrawal syndrome.” People addicted to nicotine smoke regularly to sustain their nicotine levels, maintaining the pleasure, and avoiding the discomfort of withdrawal. Other key factors that reinforce
smoking dependence include psychological and social pressures and difficulty in quitting. Smoking and Mental Health The relationship of smoking with mental health is an area of increasing scientific interest. People with mental health problems are generally more likely to smoke, with smoking prevalence as high as 75 percent of people with severe mental health problems. Smoking is related to a wide range of psychiatric diagnoses (e.g., anxiety, agoraphobia, panic disorder, depression, schizophrenia) and can act as a trigger for mental illness. However, the evidence is inconclusive on whether smoking is the cause or effect of mental illness. Patients with schizophrenia have an extremely high prevalence of smoking (about 90 percent). This may be related to smoking-induced dopamine release, which alleviates certain schizophrenic symptoms. Although nicotine may reduce symptoms in schizophrenia, the dangers of smoking far outweigh any benefits. Likewise, smoking was once thought to be protective against Parkinson’s disease (PD)
1568 Smoking because nicotine may restore dopamine to normal levels in the brain. However, the hazards associated with smoking far outweigh any conceivable protection against PD. Clinical depression and smoking are associated. This may result from genetics, social environment, personality, and coping styles. Long-term nicotine exposure on the brain may have a causal influence on major depression. A history of daily smoking may increase significantly symptoms and attacks of major depression. Although it was thought that nicotine could delay the onset of familial Alzheimer’s disease (AD), recent evidence indicates that smoking heightens the risk of AD and vascular dementia by increasing free radicals, which impair cell function and undermine immunity. Indeed, smoking may accelerate cognitive decline in nondemented elderly. Smoking may increase the mortality of people with mental disorders. For instance, smoking-related fatal disease is more prominent in patients with schizophrenia than in the general population. Persons with mental disorders should quit smoking. The health risks of smoking far outweigh any possible ameliorative effects. Helping patients to stop smoking should be a priority for mental health service providers and planners. Patients need support and assistance in quitting smoking, dealing with the root causes of their mental health problems, and finding alternative coping strategies. In several countries, policies to make mental health institutions completely smoke-free are resulting in positive health outcomes for both patients and staff. Socioeconomic Consequences Smoking kills about 5 million people annually; more deaths occur in the developing world. Half of these deaths occur during the productive years of life, causing a significant economic impact on families, communities, and societies. Moreover, smoking is strongly associated with poverty and other markers of social disadvantage. Numerous studies demonstrate higher smoking rates among the poor and less educated. In some countries, as much as 10 percent of a family’s income is diverted away from food and medical care to purchase cigarettes. The economic consequences of smoking are significant, and are borne by smokers and nonsmok-
ers alike. A 1994 report estimated that tobacco use resulted in an annual global net loss of $200 trillion, a third of this loss occurring in developing countries. These costs extend beyond direct healthcare expenditures for tobacco-related illness, encompassing lost productivity from absenteeism and premature death, social and welfare costs, and environmental costs. For example, in 1987, cigarettes sparked off one of China’s worst fires in modern history, causing 300 deaths, destroying 1.3 million hectares of land and making 5,000 people homeless. The costs due to the health and economic consequences of smoking make a compelling rationale for a concerted effort to reduce smoking. A Global Response to Reduce Smoking Interventions that effectively reduce smoking and other forms of tobacco consumption can be divided into two categories: those that reduce the demand and those that reduce the supply of tobacco. Supporting strategies include tobacco control research, establishment of surveillance and monitoring systems, consideration of litigation to recover costs of tobaccorelated healthcare, counteracting the tobacco industry and creation of funding mechanisms to support tobacco control in developing countries. Research shows that increasing the price of cigarettes and other tobacco products, primarily through tax increases, is the single most effective measure to quickly reduce short-term tobacco consumption. Equally important, raising cigarette prices has been shown to play a significant role in determining how many young people will start smoking, thus influencing long-term consumption trends. The World Bank estimates that overall, for every 10 percent increase in cigarette taxes, smoking is reduced by 4 percent. Young people, minorities and the poor are two to three times more likely to quit or smoke less in response to price increases. Hence, raising cigarette prices protects these vulnerable groups from smoking risks. Other demand reduction strategies include the following: • Comprehensive advertising bans—Evidence from 102 countries demonstrates that comprehensive advertising bans can reduce smoking by 6 percent.
• Smoke-free policies in public places and workplaces—Data from the United States indicate that these policies can reduce smoking by 4 to 10 percent. • Prominent health warnings—Half of smokers intending to quit were motivated to do so by large, graphic warnings on cigarette packets in Canada. • Information and advocacy campaigns • Cessation programs—Increasing the use of nicotine replacement therapy is estimated to potentially persuade an additional 6 million smokers in the world to quit, averting 1 million tobacco-related deaths. Measures to reduce supply include preventing cigarette smuggling, restricting youth access to cigarettes, and promoting alternatives to tobacco agriculture through crop diversification and similar strategies. Recognizing the need for a coordinated global response to the tobacco epidemic, the WHO in 1999 initiated the development of an international Framework Convention on Tobacco Control (WHO-FCTC). The WHO-FCTC is the first public health treaty with a comprehensive evidence-based mix of policy and strategic directions for reducing smoking and other forms of tobacco consumption. The WHO-FCTC was adopted on May 21, 2003, and entered into force on February 27, 2005. It currently has 140 WHO member states as parties to the convention. The global pervasiveness of smoking, its considerable adverse impact on health and survival, and the significant resources it drains from individuals, families, and societies make controlling smoking relevant to the health community, academia, the private sector, and governments. The WHO-FCTC contains the template for the policy and program mix to effectively prevent and/or reduce smoking and other forms of tobacco use. Ensuring the successful implementation of the convention worldwide is needed to avert smoking-related preventable death, disability, and chronic disease in the future. SEE ALSO: Cancer; Mental Health; Tobacco; World Health
Organization (WHO).
BIBLIOGRAPHY. Annette David and Vera Luiza da Costa
e Silva, eds., Building Blocks for Tobacco Control: A Handbook (World Health Organization, 2004); Prabhat Jha and Frank Chaloupka, eds., Tobacco Control in Developing
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Countries (Oxford University Press, 2000); Judith Mackay, Michael Eriksen, and Omar Shafey, The Tobacco Atlas, 2nd ed. (American Cancer Society, 2006); U.S. Department of Health and Human Services, The Health Consequences of Involuntary Exposure to Tobacco Smoke: A Report of the Surgeon General (U.S. Department of Health and Human Services, 2006); U.S. Department of Health and Human Services, The Health Consequences of Smoking: A Report of the Surgeon General (U.S. Department of Health and Human Services, 2004). Annette M. David, M.D., M.P.H. Health Partners, L.L.C. Mao-Sheng Ran, M.D., Ph.D. University of Guam
Smoking and Pregnancy Maternal smoking during pregnancy is one of the biggest causes of preventable disease in newborns worldwide. In 2002, 11.4 percent of pregnant woman in the United States smoked, contributing to healthcare costs reported at $366 million. Health professionals are extensively searching for ways to educate women about the many dangers that tobacco products impose on them and their infant. It is important to discuss the healthcare costs associated with maternal smoking as well as the benefits of implementing smoking cessation programs and making them available to all women worldwide. Maternal smoking causes a variety of problems to both the mother and the unborn child. Cigarettes have been associated with many complications, including but not limited to an increased risk of premature rupture of maternal membranes (PROM), stillbirths, and sudden infant death syndrome (SIDS). Studies show tobacco products can slow down the growth of the fetus contributing to both premature and low birth-weight infants. These two conditions greatly contribute to the mortality and morbidity of a newborn. New research suggests that babies born to mothers who smoke go through a withdrawal period that is comparable to the withdrawal associated with other drugs, such as cocaine. There is even an indication that up to one-third of attention deficit and hyperactivity
1570 Smoking and Pregnancy disorder (ADHD) maybe due to maternal exposure to cigarette smoke. Smoking can even cause female reproductive problems before conception occurs such as infertility, and is associated with an increased risk of ectopic pregnancies. These same risks also apply to women who do not smoke but are around high levels of secondhand smoke. Healthcare Cost Although maternal smoking is a problem worldwide, it is the highest in the United States where approximately 20 percent of women smoke. Smoking among pregnant mothers has dropped from 18.4 percent in 1990 to 11.4 percent in 2002, but is still a significant public health issue and continues to increases healthcare expenses. Public health researchers at Emory University discovered that although it costs an average $748 healthy child to stay in a normal nursery, it costs $2,496 for a child to stay in the neonatal intensive care unit (NICU). The same study found that maternal smoking increased the risk of a newborn being admitted to the NICU by 20 percent and increased their stay in the hospital by 1.1 percent. It is estimated that healthcare costs associated with tobacco exposure in utero are $738 per maternal smoker. This results in a direct cost of $227 million in 1996 dollars to Medicaid. Benefits of Cessation The longer that a woman smokes during her pregnancy, the longer harmful chemicals are exposed to her growing child, which is why it is important that health professionals focus on educating pregnant women about smoking cessation as soon as possible. By 2010, healthcare providers have aimed to reduce the amount of women who smoke while pregnant to 30 percent by the first trimester. Even if only 1 percent of smokers quit smoking before pregnancy, it would reduce healthcare costs by approximately $25 million. One concern for experts, however, is if there is enough money available to implement cessation programs for mothers, and if these programs are effective. The Centers for Disease Control and Prevention (CDC) reports that even if only one-fourth of pregnant smokers received cessation assistance that had only an 18 percent rate of complete cessation from smoking, this program could save Medicaid $25 million.
Controversy In July 2006, Lynn Paltrow, executive director of the National Advocates for Pregnant Woman, published an article that communicated her disappointment in the way the world and the United States handles smoking cessation aimed toward pregnant women. Some legislators have proposed that there be laws legally banning pregnant women from smoking which Paltrow says distracts legislators from the real issue of maternal smoking. In her opinion, lack of resources is really what prevents women from attaining the help they need when attempting to break the habit, and all that laws will do is criminalize pregnant women and compromise the health of both mother and child. She reports that the March of Dimes, American Medical Association, and American Pediatric Association also oppose public policy that criminalize pregnant women for their addiction while failing to provide the adequate education that is needed for them to quit. Overall, helping mothers to quit smoking is a public health issue that is both financially feasible and responsible. It is also what is best for mothers and child. With added support through lobbying, legislators will hopefully be convinced that advocating for insurance coverage to include smoking cessation programs for pregnant women is best for the health of all mothers and children worldwide. SEE ALSO: Centers for Disease Control and Prevention
(CDC); Perinatology; Pregnancy; Smoking; Smoking and Youth; Smoking Cessation.
BIBLIOGRAPHY. E. K. Adams, et al., “Neonatal Health Costs
Related to Smoking During Pregnancy,” Health Economics (v. , 2002); “Health Economics and Impact: Smoking Cessation in Pregnant Women,” National Center for Chronic Disease Prevention and Health Promotion (July 2002); C. L. Melvin, “State Estimates of Neonatal Health-Care Costs Associated with Maternal Smoking—United States, 1996,” Morbidity and Mortality Weekly (October 8, 2004); Lynn Paltrow, “Blaming Pregnant Women,” www.tompaine.com (cited August 2006); “Smoking During Pregnancy,” www. marchofdimes.com (cited November 2006); “Smoking During Pregnancy—United States, 1990–2002,” Morbidity and Mortality Weekly (October 8, 2004). Melody Burns University of Missouri–Kansas City
Smoking and Youth Smoking in teens is a continuing problem despite an overall decline in smoking rates among adults. Teen smokers become adult smokers with chronic health problems that utilize billions of healthcare dollars a year. If nations around the world took a stronger stance against youth smoking, these costs would plummet dramatically. Smoking Rates There are cultural differences across the world that impact smoking rates, but in general, it has persisted as a socially acceptable practice until now, when that is being called into question on many fronts. On average, the worldwide rates of teen smoking are about 20 percent, with the highest rates in Eastern Europe (33 percent) and Greenland where a staggering 55 percent of teens smoke. Whites and Hispanics are more likely to smoke than blacks and Asians. Other racial differences exist such as black smokers take longer to rid their bodies of nicotine compared to white smokers, which may explain why they generally seem to smoke fewer cigarettes. Youth Smoking Facts Nearly all smokers had their first exposure before they graduated from high school, and in the United States, 54 percent of high school students have tried cigarette smoking. Twelve percent of middle school students admitted to using tobacco once a month compared to 28 percent of high school students and 21 percent of adults. It is rare that someone starts smoking after high school, and the younger a person is when he or she starts smoking, the more likely he or she will continue into adulthood. Ninety percent of adult smokers began before the age of 18. Half of these smokers will eventually die from smoking-related diseases. Tobacco use is also thought to be the gateway for teens choosing to use other drugs and alcohol, as well as becoming involved in other risky behaviors. Teens who smoke are three times more likely than nonsmokers to use alcohol, eight times more likely to use marijuana, and 22 times more likely to use cocaine. They are also more likely to be sexually active at a younger age, drive recklessly, and participate in other illegal activities. Perhaps this is true because the barriers of what is socially acceptable in their per-
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sonal life are different than those of teens and families that do not smoke. Other Forms of Tobacco Teens are always looking for ways to justify their tobacco use, and one way is by believing that other forms of tobacco are less harmful. Other forms of tobacco include kreteks (clove cigarettes), bidis (flavored cigarettes), hookahs (water pipes), hand-rolled cigarettes or “all-natural” cigarettes, menthol cigarettes, and chewing tobacco. Some of these versions of tobacco are glamorized as special and unique, which can be very appealing to teens. It is important that we educate them that none of these forms are safer than traditional cigarettes. Tobacco-Related Illness There are several means by which tobacco causes illness. Cigarette smoke contains more than 4,000 chemicals, 60 of which cause cancer. Some of these chemicals are cyanide, benzene, formaldehyde, methanol, acetylene, nitrosamines, and ammonia. Carbon monoxide starves the body for oxygen needed to run cellular processes by binding to red blood cells in place of oxygen. Nicotine narrows blood vessels which also limits the body’s ability to deliver oxygen and other nutrients to tissues and remove wastes. Several chemicals in tobacco cause damage to blood vessel walls, making them more prone to scar and collect cholesterol deposits. These situations result in heart disease, strokes, and peripheral artery disease. Tobacco smoke also causes destruction of elastic tissues in the lungs leading to emphysema. Most of the cancer-causing chemicals do so by altering the DNA of cells leading to uncontrolled cell replication and, thus, tumor growth. Types of cancer linked to smoking include lung, breast, bladder, mouth, laryngeal, esophageal, stomach, pancreas, liver, cervix, and leukemia. Other children who do not smoke but have friends who smoke need to be aware that the risks of secondhand smoke are little different than directly choosing to smoke. Their clothes will still smell, they will still have trouble with breathing and athletic performance, it can disturb their sense of smell and taste, and it causes red and itchy eyes. Secondhand smoke causes around 3,000 nonsmokers’ lung cancer deaths each year.
1572 Smoking and Youth Addiction Much of the health information is well known by the general population, so why is it that people continue to smoke? Nicotine is the compound in tobacco that causes smoking to be addictive. It binds to receptors in the brain that cause pleasant feelings, and when it is withdrawn, it causes unpleasant side effects such as nervousness and headaches. These sensations alone are often enough to encourage people to continue smoking. There has also been a link established between people who possess a certain dopamine receptor in the brain, DRD2, and increased rates of smoking. Those who have this gene are more likely to smoke, possibly due to an increase pleasure sensation from nicotine’s dopamine-stimulating effects than someone without the gene. Depressed teens are also more likely to smoke than those who are not depressed because it elevates their mood. It is also likely that the practice of inhaling deeply while smoking is partially responsible for the feeling of relaxation that smokers experience. This can also be a useful technique for someone to use for stress relief. Smoking Behavior Development Why do teens begin to smoke? Primarily, this is thought to be due to various influences from society and our relationships including peer pressure, curiosity, advertising, availability, and exposure to other close friends and family who smoke. Youth become smokers by going through a series of stages that are influenced by different factors. Stage 1 is precontemplation, where the child is not thinking about smoking, but receives messages about it. He or she is subconsciously influenced by advertising, films, television, and role models such as parents and siblings smoking. Stage 2 is contemplation where curiosity comes about. This stage is strongly influenced by his or her friends’ behavior. Stage 3 is initiation where most young people try smoking, without becoming regular smokers. At this stage, friends are usually the strongest influence. Stage 4 is experimentation, involving repeated attempts to smoke. Nicotine’s addictive potential appears to be much stronger in young people, which makes them more likely to become regular smokers. At this stage, peer bonding is still the strongest influence.
Stage 5 is regular smoking and may involve a new set of influences including addiction, habituation, personal beliefs about the benefits of smoking, selfperception, coping ability, and various societal factors including school policy, price, and availability. Stage 6 is maintenance, which is perpetuated by addiction. Stage 7 is quitting, which occurs when the relative importance of prior and current influences changes. For example, a new nonsmoking partner or friend, increases in the price of cigarettes, or a decrease in available spending money, among others. Smoking and the Law Many people assume that because there are laws against selling cigarettes to anyone under age 18 in the United States that children must be stealing them. Fortunately, less than 1 percent of teens obtain cigarettes by theft. Most teens are purchasing them from the store or have friends or others purchase them. Research has shown that making cigarettes more difficult and expensive to obtain reduces the number of kids who smoke and the amount of cigarettes consumed. In many parts of Europe, Asia, and Africa, there is no age limit on smoking, and several countries have age limit of 15 or 16 years old. Kuwait, on the other hand, has the highest age limit at 21. Changing Youth Behavior How do we keep our children from using tobacco? This is primarily the responsibility of parents, who need to talk to them from an early age to educate them about the negative effects of smoking. Additionally, parents need to quit using tobacco in order to set a good example. Starting to talk to children in early childhood and showing them pictures about the negative impacts of smoking can have a large and lasting impact. Being creative by using analogies or examples to show them these impacts is even more effective. For example, having a child try to breath through a straw with their nose plugged can demonstrate what breathing with emphysema is like. Showing pictures of healthy lungs and lungs filled with tar from smoking is also helpful. You could remind your child how unappealing someone who smokes smells by using a personal example. When it comes to teenagers, it is important to focus on the factors that would attract them to smok-
ing. Teenage girls would respond more negatively to pictures of wrinkled skin than boys. And because teenagers are more self-conscious about their appearance, a picture of tar-stained teeth could be helpful. It is important to find out what teens think about smoking to appropriately address their misconceptions or understand their underlying reasons for smoking that may be clues to deeper problems such as depression. These discussions need to take place in a safe environment for the child, so that he or she is not fearing punishment if he or she admits to tobacco use. It is important to talk about peer pressure and encourage your child’s self-confidence, so that he or she is more able to say no to friends, while reminding him or her that a true friend will support his or her decision. Make sure you set strict house rules about tobacco in your own house before your children experiment with smoking and they are less likely to bring it home. Encourage your child to get involved in activities that prohibit smoking. Talk with teens about how smoking limits their athletic performance by decreasing the oxygen available to their muscles, thus, they are weaker and slower than other athletes. Last, talk about cost. The average smoker spends over $1,200 a year and $65,000 in their lifetime on cigarettes. Ask your teenagers what they would do with that kind of money instead of spending it on cigarettes. As a society, we should be implementing further restrictions on smoking to prevent our youth from picking up such a deadly habit at an early age when it is more likely to become a lifelong habit. Once your child is a smoker, it is important to know how to help him or her quit. It is important to avoid threats and display understanding about why they have chosen to take up the habit. You can teach them to deal with the nicotine cravings by using such techniques as deep breathing, drinking water, keeping themselves busy or substituting replacement habits such as chewing gum or sunflower seeds. Teach them to reach out to supportive friends. Encourage them to hang out at locations where they cannot smoke such as going to the movies. Encourage them to use exercise as a means of relieving stress. Help them to remember why they want to quit. A large majority of smokers begin doing so in their teenage years, so in order to address the long-term
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health impact, it is important that we address youth smoking and strive to reduce the number of children picking up the habit. In the long run, this will lead to a reduction in healthcare costs and likely economic benefit for all nations. SEE ALSO: Adolescent Health; Smoking; Smoking Cessation; Smokeless Tobacco. BIBLIOGRAPHY. American Cancer Society, “Child and Teen
Tobacco Use,” www.cancer.org/docroot/PED/content/PED_ 10_2X_Child_and_Teen_Tobacco_Use.asp?sitearea=PED (cited March 2007); American Cancer Society, “Questions about Smoking, Tobacco, and Health,” www.cancer.org/ docroot/PED/content/PED_10_2x_Questions_About_ Smoking_Tobacco_and_Health.asp (cited March 2007); J. Audrain-McGovern, et al., “Interacting Effects of Genetic Predisposition and Depression on Adolescent Smoking Progression,” American Journal of Psychiatry (v.161/7, 2004); “Minimum Legal Ages for Smoking and Purchase of Tobacco around the World,” www.geocities.jp/m_kato_ clinic/mini-age-tobacco-eng-1.html (cited March 2007); National Institute on Drug Abuse, “Black, White Teens Show Differences in Nicotine Metabolism,” www.nida.nih. gov/newsroom/06/NR1-20.html (cited March 2007); “Teen Smoking Rates around the World,” http://no-smoking. org/feb00/02-15-00-4.html (cited March 2007); Tobacco Free Kids, http://tobaccofreekids.org/research/factsheets/ pdf/0073.pdf (cited March 2007); Tobacco Information and Prevention Source (TIPS), “Facts on Youth Smoking, Health, and Performance,” www.cdc.gov/tobacco/research_ data/youth/ythsprt.htm (cited March 2007); “Youth and Cigarette Smoking. Tobacco Control Factsheets,” http:// factsheets.globalink.org/en/youth.shtml (cited March 2007); “Youth Smoking Rates Worldwide,” www.quit.org. au/article.asp?ContentID=7243 (cited March 2007). Kelli Glaser, D.O. Independent Scholar
Smoking Cessation Smoking cessation (also known as quitting or kicking the habit) is the attempt to stop smoking tobacco products such as cigarettes, cigars, and pipes. Tobacco is the single greatest cause of preventable death
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and disease in the United States today. Almost 25 percent of American adults currently smoke, and every day, an estimated 3,000 children and adolescents become regular smokers. Not only are there several health effects to the smoker and those around him or her, but there are also significant societal impacts. Each year, $100 billion are spent in the United States on tobacco-related deaths and disease. Fortunately, the number of smokers in the United States is decreasing. In 2005, an estimated 50.8 percent of American adults who had ever smoked were no longer smoking. Unfortunately, smoking cessation is not easy. Over 70 percent of current smokers have stated a desire to quit smoking, but only 2.5 percent per year are successful in permanently stopping. Smoking cessation is a difficult process, typically requiring multiple attempts. Nicotine, the active ingredient of tobacco products, is one of the most addictive drugs. Studies have shown that nicotine is just as addictive as other drugs, including heroin, cocaine, and alcohol. Addiction to nicotine leads to withdrawal when the smoker strives to quit, making it even more difficult. Immediately after smoking cessation, smokers exhibit nicotine withdrawal symptoms, including irritability, anxiety, difficulty in concentrating, insomnia, restlessness, and an increased appetite—many of the symptoms that lead to the smoker’s desire to continue to smoke. Benefits Tobacco products have been linked to an extensive list of diseases, including several types of cancer, chronic lung disease, cardiovascular disease, reproductive health effects, and sudden infant death syndrome (SIDS). The good news is that smoking cessation has considerable immediate and long-term health benefits for smokers of all ages. Former smokers decrease their risk of death from smoking shortly after cessation and this risk continues to drop for at least 10 to 15 years. By quitting at a younger age, former smokers cut their risk of death in half compared to those who continue smoking past the age of 50. Within 20 minutes of inhaling the last puff of tobacco, the heart rate, blood pressure, and body temperature of the smoker begin to decrease to normal. Within two weeks to three months, the risk of sus-
By quitting at a younger age, smokers cut their risk of death in half compared to those who continue smoking past the age of 50.
taining a heart attack decreases and lung function improves. After just one year of ceasing smoking, a former smoker’s risk of coronary heart disease is half that of a continuing smoker. This risk completely reduces to that of a nonsmoker’s risk after 15 years of not smoking. Similarly, the risk of having a stroke reduces to the levels of a nonsmoker within five to 15 years of quitting. The risk of developing lung cancer and other cancers connected to smoking decreases to half that of a current smoker after 10 years of cessation. Individual Methods of Cessation There are various approaches for smokers to reduce and stop their use of tobacco products. The single most important step in facilitating smoking cessation is screening for tobacco use. According to guidelines produced by the U. S. Department of Health and Human Services, it is essential that every healthcare professional consistently asks about the use of tobacco and assess the willingness to quit at each patient encounter. Clinicians are encouraged to use the “five A’s” for every patient who smokes: ask about smoking, advise quitting, assess current willingness to quit, assist in the quit attempt, and arrange timely follow-up. Unfortunately, this is not currently being done. According to current research, each year, almost 70 percent of
American smokers visit their primary care physician, but only between 40 and 52 percent of these smokers receive smoking cessation advice during their visits. Even brief interventions, such as physicians advising their patients to quit smoking, have been shown to be effective with cessation rates of 5 to 10 percent per year. Combining counseling and pharmacologic treatment into more intensive intervention increases the cessation rate to 20 to 25 percent per year. Self-help interventions, such as manuals, pamphlets, videos or audiotapes, and computer programs, had only modest and inconsistent success in promoting smoking cessation. Pharmacotherapy is a vital component of successful smoking cessation. According to the approved guidelines, except for a few contradictions, all smokers should be offered medication to help them quit smoking. There are five first-line medicines shown to reliably and effectively promote smoking cessation, including both nicotine replacement therapy (such as nicotine gum, nicotine inhaler, nicotine nasal spray, and the nicotine patch) and bupropion (an antidepressant prescription medicine). Each of these medications has been shown to be equally effective in promoting the smoker to quit by decreasing the symptoms of nicotine withdrawal. Additionally, it is essential for the smoker to receive counseling and behavioral therapy, either from their healthcare professional or local smoking cessation services. Evidence has shown that the most successful smokers quit by receiving counseling and pharmacotherapy together. Counseling alone doubles the smoker’s chances of successfully quitting. There is a strong dose-response relationship between the strength of tobacco-dependence counseling and its effectiveness. Counseling providing person-to-person contact (individually, in a group, or via a telephone quit line) has been shown to be the most effective. The effectiveness of this interaction is even stronger as the length of the intervention increases. The Centers for Disease Control and Prevention (CDC) suggests that smokers who are willing to quit be given practical problem-solving skills, such as encouraging the smoker to set a quit date, changing his or her environments to remove the exposure to all tobacco products from his or her life, reviewing past attempts at quitting, and developing a plan to prevent relapse. Once the smoker quits, it is essential that he or she does not ever smoke again—not even a single
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puff. Interventions should be culturally, educationally, and age appropriate, adjusting to one’s specialized population such as hospitalized smokers, members of racial and ethnic minorities, older smokers, pregnant smokers, and adolescents. Former smokers should be encouraged to continue their abstinence of tobacco and to receive interventions for preventing relapse. In general, relapse rates are the highest during the first weeks and months of cessation with a significant decrease in relapse after three months. There are multiple common impediments to successful cessation, including withdrawal symptoms, the fear of failure, weight gain, and depression. Smokers who have identified a plan to avoid or deal with these roadblocks are more likely to successfully prevent relapses. Societal Methods Not only is smoking cessation accomplished through individual smoker cessation programs, but it is also accomplished through effective population-based prevention interventions aimed at reducing access to tobacco. A report by the U. S. surgeon general recommends an increase in the regulation of tobacco products, through the advertisement, promotion, and sales of the products and protection of nonsmokers through comprehensive smoking bans. Effective regulation has been shown to not only decrease the use of tobacco, but it has also been shown to minimize the onset of smoking, particularly among young people, and decrease its acceptance as a social norm. There is evidence showing that the greatest reduction in the use of cigarettes has been achieved by increasing the cost of cigarettes. In addition, Healthy People 2010, a U.S.-based health promotion and disease prevention plan, calls for universal insurance coverage of all evidence-based treatment of tobacco dependency for every smoker, including reimbursement for both counseling and pharmacotherapy. SEE ALSO: Depression; Environmental Tobacco Smoke
(ETS); Smokeless Tobacco; Smoking and Youth.
BIBLIOGRAPHY. Centers for Disease Control and Preven-
tion Tobacco Information and Prevention Source, “You Can Quit,” www.cdc.gov/tobacco (cited February 2007); U.S. Department of Health and Human Services, “Treating Tobacco Use and Dependence—Quick Reference Guide
1576 Snellen’s Chart for Clinicians,” www.surgeongeneral.gov/tobacco (cited February 2007). Shannon Gearhart, M.D. Indiana University
Snellen’s Chart Snellen’s chart is used to measure visual acuity by determining the level of visual detail that a person can discriminate. It was developed by the Dutch ophthalmologist Herman Snellen in 1854 and was adopted by medical professionals in many countries who have used it for over 100 years. Snellen’s chart has several advantages, including sensitivity to common sources of visual impairment, but it has also come under criticism and several new types of eye chart have been proposed. Snellen’s chart is a familiar sight in physician and optometrist offices. It consists of eleven lines of block letters, also known as “optotypes,” which are constructed according to strict geometric rules and whose size decreases on each lower line of the chart. In the traditional chart, the first line traditionally consists of the single letter E, and only nine letters are used: C, D, E, F, L, O, P, T, and Z. The person whose vision is being tested stands at a specified distance from the chart (20 feet in the United States, 6 meters in countries that use the metric system) and reads each line, using only one eye, until he or she cannot decipher the letter shapes. Each row of letters is assigned a ratio which indicates the visual acuity required to read it, and the ratio for the lowest line a person can read is his or her visual acuity for that eye. In the United States, normal vision is defined as 20/20; in countries that use the metric system, it is 6/6. A ratio less than 1 (for instance, 6/10) indicates worse-than-normal vision; a ratio greater than 1 (for instance, 6/5) indicates better than normal vision. Several criticisms have been made of Snellen’s chart. One is that the number of letters presented on each line differs, so the difficulty of differentiating the letters due to size is confounded with difficulties due to visual crowding caused by the nearness of other letters: it has been established that letters are more easily read when presented on their own. In addition, the spacing between rows as well as spacing between let-
Repeatability of measurements taken with Snellen’s chart are poor, complicating any effort to measure changes in vision over time.
ters varies on Snellen’s chart, introducing a third factor which further confounds the measurements. Another criticism is that the progression of ratios among the lines of letters is irregular and somewhat arbitrary, with particularly large gaps at the lower end of the acuity scale. Finally, repeatability of measurements taken with Snellen’s chart are poor, complicating any effort to measure changes in vision over time. Alternatives to Snellen’s chart have been developed by Edmund Landolt (the Landolt C), Sergei Solovin (using Cyrillic letters), Louise Sloan, Ian Bailey and Jan Lovie, Lea Hyvärinen (the Lea chart, for preschool children), and Hugh Taylor (the Tumbling E chart, for illiterates). SEE ALSO: Diagnostic Tests; Eye Care; Eye Diseases (Gen-
eral); Low Vision; Ophthalmology; Optometrist.
BIBLIOGRAPHY. Paul McGraw, Barry Winn, and David Whitaker, “The Reliability of the Snellen Chart,” British Medical Journal (v.310, 1995).
Sarah Boslaugh BJC HealthCare, Saint Louis
Society for Healthcare Epidemiology of America (SHEA) The Society for Healthcare Epidemiology of America (SHEA) was created in 1980 to further the development of healthcare epidemiology through research and education. Goals of the society are to prevent and manage infections in patients and healthcare workers; enhance the quality of healthcare; and transform research data into policies that further healthcare initiatives. SHEA educates and trains upcoming researchers, collaborates with organizations with similar goals and missions, and promotes ethical standards in all epidemiology research. Membership to SHEA is open to all qualified individuals, with growing numbers of clinicians, pediatric scientists, surgeons, and microbiology experts joining the society. The organization shares research results with healthcare regulators, encouraging cost-effective solutions that benefit large groups of people. SHEA is comprised of many committees, including the Patient Safety/Quality Improvement Committee, which focuses on improved patient safety in hospitals; and monitors surgical infections and other healthcare infections. Members of SHEA also form special interest task forces, such as ones focusing on pediatric infectious diseases, and on the challenges of long-term care. The organization also focuses on disaster preparedness, and ways to control the spread of infection in healthcare facilities when disasters strike. More specifically, foci include pandemic influenza and avian influenza, natural disasters such as hurricanes and tsunamis, and bioterrorism incidences. SHEA collaborated with the Centers for Disease Control and Prevention (CDC) and the Division of Healthcare Quality Promotion (DHQP) in a joint initiative called “Building Healthcare Capacity in the U.S. and Internationally.” Through this initiative, the agencies formed a communications network to rapidly transmit two-way communications to prevent the spread of infection. Through this network, scientists can receive real-time health information and use what is learned in emergency situations to also prevent and control infection during nonemergency ones. The agency concentrates on the well-being of healthcare workers, sharing information about risks. As one
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example, there are significantly higher levels of tuberculosis infection in healthcare professionals in the Third World, when compared to the general population. This study highlights the relatively high risk of tuberculosis being transmitted from patients to their caregivers. In countries with limited resources, preventative measures are seldom affordable, adding to this healthcare crisis. Suggested solutions include earlier diagnosis of the disease, more effective quarantine of the patients, and increased training for healthcare workers so that they can protect themselves against infections. SHEA also posts National Institutes of Health (NIH) research results on its Web site, including the potential for a bird-flu vaccine that can be created three times as fast as traditional immunizations. SHEA publishes Infection Control and Hospital Epidemiology, a peer-reviewed monthly journal published by the University of Chicago Press. Recent articles include “Caring for Healthcare Workers: A Global Perspective,” “Duration of Time on Shift before Accidental Blood or Body Fluid Exposure for Housestaff, Nurses, and Technicians,” and “Fatigue Increases the Risk of Injury from Sharp Devices in Medical Trainees: Results from a Case-Crossover Study.” SEE ALSO: Centers for Disease Control and Prevention
(CDC); Epidemiology; Epidemiologist.
BIBLIOGRAPHY. Society for Healthcare Epidemiology of America, www.shea-online.org.(cited July 2007); Lorri A. Zipperer, ed., The Health Care Almanac: A Resource Guide to the Medical Field (American Medical Association, 1995).
Kelly Boyer Sagert Independent Scholar
Society for Nutrition Education (SNE) The Society for Nutrition Education (SNE) promotes healthy food choices and eating behaviors worldwide, representing the interests and viewpoints of nutrition educators. Through the SNE, nutrition professionals discuss research findings and teaching strategies, and share resources as they educate policy makers and the
1578 Society for Public Health Education (SOPHE) public about food and health. Two broad goals of SNE are to bolster the nutrition education profession and to grow a dynamic society that serves its members and community well. There are numerous SNE divisions, including the Communications Division, which shares information from SNE nutritionists from various disciplines for a more integrated body of knowledge. This division publicizes SNE, solicits new members, and creates publications to effectively disseminate nutrition information. The Food and Nutrition Extension Education Division allows educators to share ideas and resources, holding workshops in the United States and Canada. This division also facilitates mentoring programs for newer members. In the Healthy Aging Division, SNE members discuss nutritional ways to help the aging population remain healthy, encourage the publication of articles on quality of life for older adults, and collaborates with relevant agencies to further mutual goals. Through the Higher Education Division, research awards are granted to those who teach nutrition in postsecondary institutions. The International Nutrition Education Division is charged with implementing a more international focus in SNE, through expanded international membership and the publication of articles that share a more global perspective. Members of this committee frequently work in ethnically diverse populations. The Nutrition Education for Children Division promotes active exchanges of information among those who develop and present nutritional programs for children. In the Nutrition Education with Industry Division, members present nutrition information in academic, governmental, and business settings, among others. The Public Health Nutrition Division creates forums for discussions of public health issues, with participants ranging from healthcare workers to academic and governmental representatives. In the Social Marketing Division, members encourage people to make better food choices, to become more physically active, and to otherwise take advantage of ways to improve their health. Providing information to people with limited finances is a special focus of this division. The Sustainable Food Systems Division advocates for quality food grown under environmentally, socially, and economically
sound methodologies. The Weight Realities Division provides scientific information about weight–health connections, advocating for quality of life for people of all sizes. The division provides information about childhood obesity in a publication, “Guidelines for Childhood Obesity Prevention Programs: Promoting Healthy Weight in Children.” SNE publishes the Journal of Nutrition Education and Behavior, with articles such as “Use of a WeightLoss Index for Evaluating Weight Management in Adults” and “Development and Evaluation of the Nutrition Component of the Rapid Eating and Activity Assessment for Patients (REAP): A New Tool for Primary Care Providers.” SNE lobbies the government as well to make nutritionally sound decisions, praising them for including more fruits, vegetables, and grains as food choices in the Women, Infants, and Children (WIC) program, while advocating for greater proportions of each, along with the addition of yogurts for calcium-rich options. SEE ALSO: Nutrition; Nutritionist. BIBLIOGRAPHY. Society for Nutrition Education, www.
sne.org.(cited July 2007); Lorri A. Zipperer, ed., The Health Care Almanac: A Resource Guide to the Medical Field (American Medical Association, 1995). Kelly Boyer Sagert Independent Scholar
Society for Public Health Education (SOPHE) The Society for Public Health Education (SOPHE) is an international professional association; its 4,000 members are health education professionals and students. SOPHE’s mission is to provide leadership to health education professionals, so as to improve health through the advances in health theory, research, education, practice, and promotion. Founded in 1950, SOPHE supports research on health education and promotion, advocates for high standards for health professionals, and lobbies for health-conscious legislative policies. SOPHE serves as the sole professional organization that focuses
Soft Tissue Sarcoma
entirely on public health education and promotion. Strategic goals include advocating for health, marketing the health education profession, actively addressing health disparity issues, and taking a major role in shaping public health policy and health education. Ethically, health educators, according to SOPHE, must consider all sides of health issues and give priority to that which promotes quality of living for individuals. Topics of special interest for SOPHE members include children, adolescent, and school health; health communications and social marketing; international and cross-cultural health; community health; anthropology and public health; medical care/patient education; and worksite health. Current advocacy priorities include environmental health issues, eliminating health disparities, and school health. Initiatives include Unintentional Injury and Violence Prevention, which takes the stand that injuries are not random incidents; as with diseases, there are risk factors that can be identified in the quest to prevent them from happening. SOPHE includes car crashes, falls, suicides, drownings, and youth violence in this category. It is also its philosophy that individual injuries have a negative impact on overall society because of medical expenses, police and fire services, property damage, and so forth. To predict and prevent/reduce injuries and violence, SOPHE is coordinating a comprehensive program, using the expertise of health professionals, governmental policy makers, engineers, and other professionals. SOPHE works to create strong bonds among members, some of whom are researchers and others are practitioners. A regular newsletter feature in News & Views is “Tools of the Trade.” In this column, cuttingedge research is described in a way that helps its findings translate into practical applications. SOPHE encourages strong collaborations with other relevant organizations, naming representatives to serve on committees in the Public Health Functions Steering Committee, the National Cholesterol Education Program, and the National Coalition for Promoting Physical Activity. Members of the agency receive subscriptions to Health Education and Behavior (HEB), SOPHE’s leading journal that studies social and behavioral patterns, analyzing how changes in either affect health and quality of life. The journal provides information on health education programs and intervention strategies to im-
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prove social and behavioral health. Regular columns include “Perspectives,” which analyzes a complex subject, and “Practice Notes,” which describes innovative and successful health education programs. Through its Web site, SOPHE provides long-distance learning on topics such as “On the Road to Eliminating Racial and Ethnic Health Disparities,” “Healthy Kids: Innovative Programs for Safe Schools and Communities,” and “Health as a Human Right: Health Education, Equality, and Social Justice for All.” SEE ALSO: National Cholesterol Education Program
(NCEP); Public Health.
BIBLIOGRAPHY. Society for Public Health Education,
www.sophe.org. (cited July 2007); Lorri A. Zipperer, ed., The Health Care Almanac: A Resource Guide to the Medical Field (American Medical Association, 1995). Kelly Boyer Sagert Independent Scholar
Soft Tissue Sarcoma Soft tissue sarcomas are rare tumors that develop from the mesenchymal tissue layer, one of the three embryologic tissue types. The mesenchymal layer gives rise to deep skin tissues, blood vessels, fibrous tissues surrounding joints, cartilage, bone, smooth and striated muscles, and fat. Malignant tumors involving the peripheral nerves (ectoderm in origin) develop similarly and the treatment and outcomes are similar as well. The occurrence of soft tissue sarcoma in the United States is approximately 9,530 cases annually, which is only 0.7 percent of all malignant tumors. Of all the sarcomas 70 percent develop from soft tissue and 30 percent originate in bone. Soft tissue sarcomas can be locally aggressive with direct extension to the surrounding tissues or can rarely metastasize (spread) to distant sites. The development of these sarcomas is thought to be malignant from the outset, that is, not developing from a benign lesion, which has undergone malignant transformation. Because these tumors are relatively rare and manifest in a multiplicity of histological subtypes and idiosyncratic biologic behavior, the natural his-
1580 Soft Tissue Sarcoma tory and response to treatment is less than clear. As an example, according to the American Cancer Society 234,460 new cases of prostate cancer and 212,920 new cases of female breast cancer in America are estimated for 2006. In comparison, it is estimated that 500 cases of liposarcoma of the thigh will occur in 2006. The incidence of new prostate cancers is 468 times greater and new female breast cancers is 425 times greater than that of new thigh soft tissue sarcomas. These statistics indicate the limited numbers of patients who undergo various combinations of treatment so that it is difficult to determine which of the treatments is best. Generally, there is no definite cause for soft tissue sarcomas but some factors do predispose for the condition, such as chronic irritation, lymphedema, genetic predisposition, radiation and/or chemotherapy exposure and chemical carcinogens. The occurrence of one specific type of sarcoma (Kaposi’s sarcoma) is associated with the HIV and human herpes virus 8. Soft tissue sarcoma is classified as to the type of tissue from which the tumor developed. For example, sarcomas, which developed from fatty tissue, blood vessels, and striated muscle, would be termed liposarcoma, angiosarcoma, and rhabdomyosarcoma, respectively. Oftentimes it is not possible to determine the origin of the sarcoma and the sarcoma is named according to the structure seen on microscopy. Grading the sarcoma based on examination under the microscope is useful in determining the aggressiveness of the tumor and the likelihood that the sarcoma may metastasize (spread to non-contiguous tissues). The lower grades of sarcomas are more likely to stay aggressive locally and less likely to metastasize. Sarcomas are found throughout the body, including the extremities, retroperitoneum, head and neck, alimentary canal, genitourinary system, and uterus. The initial presentation of a soft tissue sarcoma is a palpable mass. The diagnosis of the type of soft tissue sarcoma can be made only with an adequate biopsy and special histological and immunohistological stains of the tissue. The initial biopsy should be adequate for diagnosis and should be performed by a surgeon who is skilled in oncologic diseases. If the initial biopsy is not adequately performed, the later definitive surgery may have to involve the removal of larger areas than would have been initially required.
Metastasis is generally considered to occur through hematogenous or lymphatic routes. Despite the original site of the soft tissue sarcoma, the lung is nearly always a site of metastasis and is usually the ultimate cause of death. The diagnosis of soft tissue sarcoma includes a thorough history and physical examination of the patient. Lymphatic areas which drain the affected body part should be scrupulously examined since the spread of sarcomas are generally first to regional lymph nodes and then systemically. Presence of edema of an extremity where a sarcoma has been found indicates that an obstruction to lymph drainage has occurred, presumptively from regionally metastatic sarcoma. Radiographic studies should include plain x-ray and computerized axial tomography (CT) and magnetic resonance imagining (MRI). Because of the superiority of both CT and MRI in differing tissue areas and in exposing characteristics of the tumefaction both studies generally are performed. The CT is much superior in identifying destruction of bone and for imaging regional lymph nodes. A CT of the chest of a newly diagnosed sarcoma patient is standard because of the probability of metastasis to the lungs in those sarcomas, which do metastasize. The MRI has excellent soft tissue contrast and can minimize the bone artifact and thus MRI is preferred for soft tissue sarcomas of the head and neck, pelvis, extremity, and in parameningeal areas. Furthermore, MRI is superior to CT in relating the tumor to fascia, bones, nerves, and blood vessels. Surgery is the only definitive potential cure for soft tissue sarcoma. Radiation therapy to the area after surgery (adjuvant therapy) helps to control locally recurrent disease but does not alter long-term survival rates. Pre-operative radiation therapy (neoadjuvant) can be delivered to smaller areas and in lower doses. Experience has shown that there is an increased risk of post-operative wound infections with this technique. Chemotherapy, except in childhood rhabdomyosarcoma and extraskeletal Ewing’s sarcoma has not shown consistent promise in long term survival and there have been no randomized clinical trials to support the use of chemotherapy in all soft tissue sarcomas. If the patient presents initially with wide spread soft tissue sarcoma and complications (edema, etc.) then radiotherapy as a stand-alone treatment can be
Solomon Islands
undertaken. Paradoxically, radiation itself can cause certain types of soft tissue sarcoma. For instance, in one study there was a definite increase in angiosarcoma in women who underwent radiation therapy due to breast cancer. A secondary soft tissue sarcoma developed in children who were treated with radiation therapy and chemotherapy. If the child underwent initial radiotherapy/chemotherapy for a solid tumor, then osteosarcoma was the most frequently occurring second primary cancer during the next 20 years. It is often said that an acute injury has been associated with the development of a soft tissue sarcoma. Generally, the trauma is thought to have caused attention to the area where a here-to-fore undiagnosed soft tissue sarcoma is developing. More randomized clinical trials are needed to identify protocols combining surgery, radiation and chemotherapy in order to offer soft tissue sarcoma patients best practice care. See Also: American Cancer Society (ACS); Cancer (Gen-
eral); Chemotherapy.
BIBLIOGRAPHY. American Cancer Society, Cancer Statis-
tics 2006, www.cancer.org (cited September 21, 2006); Steven Charous, M.D. and Bruce E. Brockstein, M.D., “Head and Neck sarcomas,” www.uptodate.com (cited August 2006); Thomas F. DeLaney, M.D. and Diane MF Savarese, M.D., “Overview of Soft Tissue Sarcoma,” www.uptodate.com (cited August 2006); Thomas F. DeLaney, M.D., “Pathogenetic Factors in Soft Tissue and Bone Sarcomas,” www.uptodate.com (cited August 2006); Thomas F. DeLaney, M.D. and David C. Harmon, M.D., “Treatment of Soft Tissue Sarcoma of the Extremities,” www.uptodate.com (cited August 2006); Suzanne George, M.D. and George D. Demetri, M.D., “Treatment of Metastatic Soft Tissue Sarcoma,” www.uptodate.com (cited August 2006). Richard K. Ogden, D.O., FACOFP, FAAFP Kansas City University of Medicine and Biosciences
Solomon Islands The Solomon Islands is an island nation in the Pacific Ocean, east of Papua New Guinea. The island chain
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stretches for 930 miles from east to west and encompasses nearly 1,000 islands. Once a British colony, the Solomon Islands has been self-governing since 1976 and became an independent nation in 1978. It remains part of the Commonwealth Realm, and Queen Elizabeth II is the official head of state. Tensions between the government and insurgent groups has been a serious concern in recent years, leading to the Regional Assistance Mission to the Solomon Islands (RAMSI), a multinational police force of about 2,000 peacekeepers, to patrol the islands. The population is 566,800 and growing at 2.54 percent annually. The birth rate is 29.27 per 1,000 and the death rate is 3.87 per 1,000. Median age is 19.1 years. Life expectancy is 70.64 years for males and 75.81 years for females. Gross national income is $580 per person, with most people engaged in subsistence farming and fishing. The health of Solomon Islanders is in a transition phase. Communicable diseases still comprise an important part of the disease burden, stemming in large part from limited clean water and sanitation. Morbidity is driven by acute respiratory infections, fevers, malaria, skin diseases, ear infections, yaws (a chronic, bacterial skin infection that can lead to destruction of the bones and joints), diarrhea, and conjunctivitis. Despite mosquito-eradication programs stretching back to the 1970s, malaria remains widespread, with 90,000 cases in 2004 alone. Mortality is driven by cardiovascular disease, cancers, malaria, and pneumonia. Child mortality is 24 deaths per 1,000 for infants and 29 deaths per 1,000 for children under 5. About 13 percent of children are born with low birthweight. Immunization rates are 75 percent for polio, 72 percent for measles, and 82 percent for DPT, but these diseases are rarely seen given the isolation of the population. The total fertility rate for women is 3.78 children. Only 11 percent of women use contraception. Maternal mortality is high at 130 deaths per 100,000 live births. There are 12 general hospitals, 29 district hospitals, 3 private hospitals, and 116 health centers spread throughout the islands. Medical personnel consists of 89 physicians, 620 nurses, 74 midwives, and 493 health workers. The islands have a school of nursing, and is currently attempting to restart its midwifery program. It is also trying to strengthen its continuing education programs for medical staff through coop-
1582 Somalia erative programs with institutions across the Pacific. The Ministry of Health cites financial constraints, lack of up-to-date epidemiological information, lack of supplies and equipment, lack of transport and communication between islands, and lack of management within the health workforce as the major problems in providing islanders with quality care. See Also: Healthcare, Asia and Oceania. Bibliography. Central Intelligence Agency, “Solomon
Islands,” CIA World Factbook. www.cia.gov/library/publications/the-world-factbook/geos/bp.html (cited July 2007); Ministry of Health, Solomon Islands, “Health Plan, 2004,” www.commerce.gov.sb/MOH/2004 percent20health percent20plan-MOH.pdf (cited July 2007); United Nations Children’s Fund “Solomon Islands—Statistics,” www. unicef.org/infobycountry/solomonislands_statistics.html (cited July 2007); World Health Organization, “Solomon Islands: Country Profile,” www.wpro.who.int/NR/rdonlyres/ 3B9C9A4A-D7A9-482D-B495-828BCA1523D2/0/35_Solomon_Islands.pdf (cited July 2007). Heather K. Michon Independent Scholar
Somalia Somalia is located on the Horn of Africa, with a coastline along the Gulf of Aden and the Indian Ocean on the continent’s eastern edge. Its neighbors are Ethiopia, Djibouti, and Kenya. The territory was granted independence by Italy and the Britain in 1960. The national government collapsed in 1991, leaving warring factions control different regions. Low-intensity civil war has been a constant factor in Somali life, destroying the country’s already fragile economy and public infrastructure and bring much hardship to the population. Population estimates are hard to come by, as the most complete census was taken in 1975 and many Somalis are nomads and thus difficult to count. Extrapolating from the 1975 data, demographers put the current population at around 9 million, with an estimated 2.83 percent annual growth rate. The birth rate is 44.6 per 1,000 and the death rate is 16.28 per 1,000.
Median age is 17.6 years. Life expectancy is 47.56 years for males and 50.69 years for females. Gross national income is $130 per capita, with more than 71 percent of the people relying on subsistence agriculture. Food security has diminished in Somalia in recent years. By the end of 2005, almost a million Somalis required food assistance from aid organizations, and almost 200,000 were considered critically malnourished. Morbidity and mortality are driven by communicable disease. Diarrhea, including cholera, is the leading cause of hospital admissions and deaths. Only 29 percent have safe drinking water. Sanitation ranges from 48 percent in the urban areas to 14 percent or less in rural areas. Typhoid, dengue fever, schistosomiasis, hepatitis A and hepatitis E are prevalent. As in many majority-Muslim nations, Somalia has a low adult prevalence rate for HIV/AIDS, at just 0.9 percent. Tuberculosis rates are high for the region, with 673 cases per 100,000 and 117 deaths per 100,000. The spread of TB relates primarily to the crowded conditions in which many Somalis live. Child mortality rates are high. In infants younger than one, there are 133 deaths per 1,000. For those between the ages of one and five, the rate is almost double, at 225 deaths per 1,000. As with adults, diarrhea is a major contributing factor in mortality. In a 2000 survey by UNICEF, 25 percent of children under five were found to have suffered from diarrhea within two weeks of the survey period. Female genital mutilation is universal among Somali women. Education is not encouraged, and only 25 percent of women are literate. Girls are often married as young as 14 or 15 years of age. The total fertility rate is one of the world’s highest, at 6.68 children per women. Thirty-two percent receive prenatal care, and 25 percent have a trained attendant during childbirth. This contributes to a maternal mortality rate of 1,100 deaths per 100,000, or a one in 10 lifetime risk of dying in childbirth. Hospitals, where they exist, are understaffed. The World Health Organization states the Somalia has lost an entire generation of medical professional due to war and poverty. There are 84 hospitals, 199 mother/child wellness clinics, 525 heath posts, 91 private clinics and 51 school clinics within Somalia, but many of these facilities have been decimated by fighting or neglect, and most Somalis lack the funds to pay for treatment. The
Somatic Mutation
World Health Organization and other non-governmental groups have had to take over some of the functions of the Ministry of Health due to political disarray. See Also: Healthcare, Africa; Refugee Health. Bibliography. BBC News, “Tsunami: Somalia’s Slow Re-
covery,” newswww.bbc.net.uk/1/hi/world/africa/4560246 .stm (cited June 2007); “Somalia—Statistics”. Research Africa, “Somalia,” www.researchafrica.rti.org/ indexcfm?fuseaction=home.country_view&country_id=38 (cited June 2007); The Joint United Nations Programme on HIV/AIDS, “Somalia,” www.unaids.org/en/Regions_ Countries/Countries/somalia.asp (cited June 2007); United Nations Children’s Fund, www.unicef.org/info bycountry/somalia_statistics.html#28 (cited June 2007); Health Action in Crisis: Somalia”. World Health Organization. www.who.int/hac/crises/som/background/Somalia_ Dec05.pdf (cited June 2007). Heather K. Michon Independent Scholar
Somatic Mutation Also known as acquired mutation, somatic mutation is an alteration of genetic matter which occurs after the time of conception and affects somatic cells (as opposed to germline mutation which affects germ cells). A principal consequence of affecting only somatic cells is that such mutations cannot be passed to offspring. However, somatic mutations are normally transmitted to all cells descended from the original mutant cell, giving rise of a clone (colony) of cells bearing the somatic mutation. Mutations of this sort are critical in the development of various cancers as well as in the explanation of parents with certain disease states who fail to predictably pass on certain alleles to their offspring. Cancer-Related Genes Subject to Somatic Mutation The Weinberg Progression Model identifies six somatic characteristics shared by all tumors, but the relative role inheritance and somatic mutation play in each characteristic is a complex function of the dis-
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ease in question, the family history of the subject, and other factors such as environmental exposure. Of greatest importance in the study of modern medical practices are self-sufficiency in growth factors and the loss of inhibition to growth factors. Proto-oncogenes are normal genes that encode proteins responsible for normal cellular growth. When subject to somatic mutation, proto-oncogenes may become oncogenes, leading to unregulated cell growth and proliferation through self-sufficiency in growth signals. Typically, oncogenes act in a dominant manner, needing only one mutated copy (out of two) to have a physiological impact. In contrast, tumor suppressor genes, which encode proteins responsible for antigrowth signals, typically function in a recessive manner and require mutations to both copies before physiological consequences manifest themselves in insensitivity to antigrowth signals. Individuals who are born heterozygous for a tumor suppressor gene (via inherited mutation) require only one somatic mutation event to alter the antigrowth signaling pathway, whereas individuals born without such a hereditary mutation require two somatic mutation events to yield the same outcome, a phenomenon known as the loss of heterozygosity. Somatic Mutation in Atypical Inheritance In the absence of molecular genetic techniques, many disease states with simple Mendelian inheritance can still be accurately studied. A clinical diagnosis of such a disease can often allow a physician or genetic counselor to provide information on the expected likelihood that such a disease state will be passed on to offspring or that offspring will be carriers for the disease state. Somatic mutation may, however, lead to incorrect conclusions in the absence of confirmation via molecular genetic techniques. Suppose a father suffers from an autosomal dominant disorder. He expects half of his offspring to be affected and may, for this reason, choose not to reproduce. However, good genetic counseling may reveal that neither of the man’s parents were afflicted with the disease. This leads to the conclusion that the autosomal dominant allele was not inherited, it was acquired via a somatic mutation. Genetic testing can confirm this determination and
1584 Soper, Fred L. allow counselors to reassess the risk of transmission for the potential father. SEE ALSO: Cancer; Germline Mutation; Programmed Cell
Death.
BIBLIOGRAPHY. R.L. Nussbaum, et al., Thompson &
Thompson: Genetics in Medicine, 6th ed., revised reprint (Saunders, 2004); W. Bursch, et al., “Programmed Cell Death (PCD): Apoptosis, Autophagic PCD or Others?” Annals of the New York Academy of Sciences (v.926, 2000). Bimal P. Chaudhari Boston University
Soper, Fred L. (1893–1977) Born on December 13, 1893, in Hutchinson, Kansas, to Socrates and Mary Ann Soper, Fred Lowe Soper’s work on infectious disease control—focusing on yellow fever, malaria, and typhus—earned him his reputation as one of the 20th century’s most effective public health professionals. Soper earned a B.A. (1914) and M.S. in Embryology (1916) from the University of Kansas, and an M.D. from the University of Chicago (1918). After interning at the Cook County Hospital, Soper married Juliet Snider (December 27, 1919) and began working for the Rockefeller Foundation’s International Health Board in January 1920. For two years, Soper conducted hookworm campaigns in northeastern Brazil. In 1922, he returned to the United States to earn an M.A. at the Johns Hopkins School of Hygiene and Public Health. From 1923 to 1927, he administered hookworm programs in Paraguay. While there, he completed his Ph.D. Soper focused significant efforts toward campaigns against yellow fever and malaria, determining methods to diagnose yellow fever, post mortem, through liver tissue. In 1942, he became an infectious disease consultant to the U.S. secretary of war, coordinating delousing campaigns in Egypt, Algeria, and Italy. Named the Rockefeller director for Africa and the Middle East in 1946, the follow-
ing year he was voted as director of the Pan American Sanitary Bureau (PASB); he kept this position until 1959, during which time he persuaded the World Health Organization (WHO) to name PASB the Regional Office for the Americas of WHO. In this capacity, Soper worked to eradicate South and Central America of yaws, urban yellow fever, malaria, and smallpox. In 1946, he received the Lasker Award for his eradication efforts. Other awards received include the Theobald Smith Gold Medal (1949), Pan American Health Organization Gold Medal (1959), American Public Health Association Sedgwick Medal (1966), World Health Organization Leon Bernard Foundation Prize (1967), and the American Society of Tropical Medicine and Hygiene Walter Reed Medal (1972). Soper continued to serve as an international health consultant after retirement and he published more than 100 articles and books, including Building the Health Bridge (1970). His memoirs, Ventures in World Health, were published in 1977, shortly after his death on February 9. SEE ALSO: Infectious Diseases; World Health Organization (WHO). BIBLIOGRAPHY. “Fred L. Soper, MD, DrPH (1893–
1977),” Pan American Health and Education Foundation, www.pahef.org/awards/health/biography (cited May 2007); “The Fred L. Soper Papers,” Profiles in Science: National Library of Medicine, http://profiles.nlm. nih.gov/VV/Views/Exhibit/narrative/biographical.html (cited May 2007). Kelly Boyer Sagert Independent Scholar
South Africa South Africa is located on the southern tip of the continent of Africa and borders Namibia, Botswana, Zimbabwe, Mozambique, Swaziland and Lesotho. With a population of nearly 47 million, South Africa has problems with hunger, poverty and one of the highest rates of HIV/Aids in the world. The constitution
Spain
signed on December 10, 1996 includes a bill of rights to guarantee in addition to other common rights, the right to healthy environment, housing, healthcare, food and water and education. The Ministry of health oversees the national system to ensure all South Africans have access to affordable and quality health care. To meet this goal the Ministry is working on preventive medicine and improving access. In South Africa 5 million people are infected with HIV/AIDS (most are married men and women). Pregnant women can pass the disease on to their baby. Medications are available for treatment though the cost of medication is prohibitive to treatment as is the political nature of the disease. Until recently, the president refused to allow physicians to treat with medication to control the disease because of concerns over the safety of the medication and a belief that poverty was the cause of the disease instead of the HIV virus. AIDS is the main cause of death for females ages 15 to 39. For travelers to South Africa, care should be exercised to prevent certain infectious diseases. Malaria from the bite of an infected mosquito causes symptoms of fever, chills, sweats, headache, body aches, nausea and vomiting, fatigue occurring at least 7 to 9 days after being bitten. Malaria infections with Plasmodium falciparum, if not promptly treated, may cause kidney failure, coma, and death. Malaria may cause anemia and jaundice. Medications are available to prevent infection, though the most commonly used chloroquine is not an effective antimalarial drug in South Africa. Areas with malaria risk in South Africa include low-altitude areas of the Mpumalanga Province, Northern Province (Limpopo), northeastern KwaZulu-Natal as far south as the Tugela River and Kruger National Park. In addition to malaria, disease risks in rural areas include Dengue, River Blindness, African tick bite fever, rickettsial infection and African trypanosomiasis (African Sleeping Sickness) transmitted by the bite of the tsetse fly, diseases carried by insects. Protecting against insect bites will help to prevent these diseases. Schistosomiasis is a parasitic infection found in fresh water in Southern African countries and other tropical and sub-tropical areas. To avoid infection, travelers should not wade, swim or bathe in fresh or
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untreated water (streams, lakes, ponds). Recent reported cases include swimming in a pond at a resort in Tanzania and by whitewater rafters on the Nile River in Uganda. Travelers who wade, swim, or bathe in contaminated freshwater are at greatest risk. Even water that looks clean may be contaminated with the microscopic organisms that carry schistosomiasis and other diseases. Many South Africans rely on traditional healers (sangomas) for spiritual and physical well being. Over 200,000 traditional healers (both men and women) practice in South Africa. These healers have a wide knowledge of natural medicines including tree roots and herbs. In many cases, traditional healers are the only medical help available. SEE ALSO: Dengue; Malaria: World Health Organization,
(WHO).
BIBLIOGRAPHY. “Department of Health”, www.doh.gov.za
(cited August 2007); Centers for Disease Control and Prevention, “Preparing for Your Trip to South Africa,” www. cdc.gov/travel/destinationSouthAfrica.aspx. (cited August 2007). Lyn Michaud Independent Scholar
Spain The Kingdom of Spain has one of the most dynamic economies in Europe today. The economy is growing at a rate of 3.5 percent and inflation (3.4 percent) is under control. However, relatively high unemployment (9.2 percent) continues to be of concern. The per capita income ($25,600) is 80 percent of that of the four leading European economies, and Spain ranks 36th in world incomes. Spain’s wealth is unevenly distributed among the rich and poor, and the top 10 percent of the population hold 25.2 percent of resources, while the bottom 10 percent share 2.8 percent. Spain has a Gini Inequality Coefficient of 32.5. The country is in the process of ongoing major economic and social reforms that have resulted in greater access to healthcare. A survey conducted by the government
1586 Spain in 1997 revealed that 99.8 percent of the population was covered by health insurance. According to the United Nations Development Programme (UNDP) Human Development Reports, Spain has the 19th highest standard of living among nations of the world. Fifteen percent of the total budget is allocated to health. The government expends 7.7 percent of the Gross Domestic Product (GDP) on health-related programs, allocating $1,853 (international dollars) per capita. The government is responsible for 71.3 percent of total health spending, and 7 percent of government funds are directed toward social security. The private sector provides 28.7 percent of total health expenditures, and out-of-pocket expenses account for 82 percent of private spending. There are 3.30 physicians, 7.67 nurses, 0.15 midwives, 0.49 dentists, and 0.87 pharmacists per 1,000 population in Spain. Spain’s basic health plan is financed by taxes, and many Spaniards supplement this coverage with private insurance. Physicians are considered public employees in Spain, and their salaries are established by the government. The passage of Act 16/2003 on Cohesion and Quality in the National Health System instituted major health reforms that were designed to reduce inequities in healthcare among the Spanish population. As a result, most of the responsibility for healthcare was transferred to local communities. At the central government level, the Health Institute is charged with the responsibility for managing healthcare. In practice, this role consists of coordinating healthcare among the various communities that are directly involved in delivering healthcare. Social security covers the elderly, the disabled, and survivors. The system is classified according to occupation, and workers pay 4.7 percent of their wages into the program. Employers contribute an additional 23.6 percent of earnings, and government subsidies account for the remaining funds. Cash benefits are paid to workers who are seriously ill and to new mothers. Women on maternity leave and mothers of adoptive and foster children receive full salary for 16 weeks. Fathers may receive full salary for 10 weeks. If both parents are employed, they may share leave time. With the 19th highest life expectancy in the world, the population of 40,397,842 has a life expectancy of 79.65 years, with females outliving males an average of seven years. The population is highly literate (97.9
percent), but there is a slight difference between male (98.7 percent) and female (97.2 percent) literacy. All of the relevant age groups are enrolled in elementary and secondary schools. Spain has the 14th lowest fertility rate in the world. Despite the fact that nearly threefourths of the population are Roman Catholic, 81 percent of Spanish women use some method of birth control. Women give birth at a rate of 1.28 children each. The adjusted maternal mortality rate of four deaths per 100,000 live births is among the lowest in the world. Spain has the 15th lowest infant mortality rate among the nations of the world (4.37 deaths per 1,000 live births). Between 1990 and 2004, infant and under-5 mortality were significantly reduced, declining from 8 to 3 deaths per 1,000 live births and from 9 to 5 deaths per 1,000 live births, respectively. Six percent of infants are underweight at birth. Infant immunization rates are high as might be expected. Ninety-eight percent are immunized against diphtheria, pertussis, and tetanus (DPT1); 97 percent against polio, measles, and hepatitis B; and 96 against DPT3 and Haemophilus influenzae type B. Spain is vulnerable to periodic droughts that endanger health. Heavy industrialization has resulted in air pollution and has threatened water quality and quantity. The Mediterranean Sea is heavily polluted from raw sewage and from the effluents that have accompanied offshore production of oil and gas. The HIV/AIDS adult prevalence rate in Spain is 0.7 percent. Around 140,000 people are living with this disease, and it has proved fatal to around 1,000. This is the highest death toll from HIV/AIDS-related conditions in Europe, and death rates among men aged 30 to 44 years and among children who are infected with the disease by mother-to-child transmission are of grave concern to health and government officials. Other communicable diseases also generate concern in Spain. In 2000, meningococcal disease was identified, and legionellosis surfaced the following year. Spain was one of several countries that experienced an outbreak of severe acute respiratory syndrome (SARS) in spring 2003, and incidences of human influenza were widespread the following winter. The leading causes of death among Spanish women are circulatory system diseases, occurring generally in women over the age of 70. Among the general population, cardiovascular disease causes one in every
Speech and Communication Disorders
three deaths; however, incidences have been steadily decreasing. Cancer, particularly breast cancer, is the second most frequent cause of death among Spanish women. The third and fourth leading causes of death are respiratory diseases and digestive illnesses. External deaths are also a leading cause of death among male Spaniards. SEE ALSO: Environmental Health; Healthcare, Europe. BIBLIOGRAPHY. Central Intelligence Agency, “Spain,”
World Factbook www.cia.gov/cia/publications/factbook/ geos/sp.html (cited June 2007); Commission on the Status of Women, “Spain,” www.un.org/womenwatch/daw/ Review/responses/SPAIN-English.pdf (cited June 2007); Spencer Di Scala, Twentieth Century Europe: Politics, Society, Culture (McGraw-Hill, 2004); Sandra Halperin, War and Social Change in Modern Europe: The Great Transformation Revisited (Cambridge University Press, 2004); Martin A. Levin and Martin Shapiro, eds., Transatlantic Policymaking in an Age of Austerity: Diversity and Drift (Georgetown University Press, 2004); Jeremy Rifkin, The European Dream: How Europe’s Vision of the Future Is Quietly Eclipsing the American Dream (Jeremy P. Tarcher/Penguin, 2004); Social Security Administration, “Spain,” www.ssa.gov/policy/docs/progdesc/ssptw/20022003/europe/spain.html (cited June 2007); United Nations Children’s Fund, “Spain,” www.unicef.org/infobycountry/spain_statistics.html (cited June 2007); World Bank, “Spain Data Profile,” http://devdata.worldbank. org/external/CPProfile.asp?PTYPE=CP&CCODE=ESP (cited June 2007); World Health Organization, “Highlights on Health in Spain,” www.euro.who.int/document/ chh/spa_highlights.pdf (cited June 2007); World Health Organization, “Spain,” www.who.int/countries/esp/en/ (cited June 2007). Elizabeth R. Purdy, Ph.D. Independent Scholar
Speech and Communication Disorders Speech and communication disorders are impairments that affect the ability to communicate, comprehend, and use verbal spoken and written languag-
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es, and also other symbol systems, called nonverbal languages (e.g., visual language, body language, etc.). Their severity can range from a few errors, for instance, in uttering speech sounds or words, to a total loss of the ability to effectively communicate. This can affect even subjects’ developing of thoughts, which is a prerequisite for the enacting of behaviours and social interaction. In communication, the functions and skills of voice, speech, and language are deeply related. In fact, those subjects who are affected by a congenital deafness, and experience therefore a delay in acquiring and mastering verbal language, may have trouble not only in the discrimination of similar sounds (in decoding as well as in producing oral messages), but also in the distinction of related concepts. Voice is the sound produced by the airflow coming from the chest: during exhalation, the air held in the lungs is gradually released and travels to the trachea and the larynx, where the vocal cords (two bands of muscular tissue) are located. When a subject talks, laughs, sings, or cries (as well as when an infant babbles or coos), his or her vocal cords are brought closer together (so that the air from the lungs is forced between them) and vibrate, giving origin to a sound; this process is called phonation. Therefore, voice production involves respiration and phonation and requires the precise coordination of many specific muscles. Speech is originated through a complex process, coordinated and controlled by the brain, through the nervous system. The sound originated by the vocal cords can be accurately modulated as regards pitch, volume, timbre, rhythm, and so forth, by means of well-defined muscle movements, which involve the throat, palate, tongue, lips, and teeth. Therefore, speech disorders can be related to voice impairments (for instance, if the voice has an unpleasant timbre) and resonance problems (for example, if there are abnormalities in the air cavities of throat, mouth, or nose), and can concern articulation (if one or more sounds are incorrectly produced), prosody (if pitch and volume organization are inappropriate), fluency, and rhythm of speech. Human beings communicate through languages. Verbal and nonverbal languages are communication systems that permit communication partners to define, express, and explain their thoughts, feelings, and behaviors, making their sharing and development
1588 Speech and Communication Disorders possible. Verbal language disorders can concern morphology (the structure of words and the rules of word construction), syntax (the combination of words in meaningful sentences), semantics (the meaning of words and sentences), and pragmatics (the use of words and sentences in appropriate social ways). The written form of verbal languages can be impaired by literacy disorders, which affect the ability to read and write texts. Speech and communication disorders can be caused by congenital or acquired hearing impairments, craniofacial anomalies (such as cleft lip and palate), neurologic diseases, or injuries that provoke weakness or scarce coordination of oral muscles (e.g., head and neck cancer, muscular dystrophy, stroke, Tourette’s syndrome, traumatic brain injury, etc.); they can also be related to developmental learning factors (this occurs, for instance, in articulation disorders, stuttering, dyslexia, etc.) or psychiatric-behavioral disorders which impair auditory attention, discrimination and memory, or information processing (e.g., Asperger’s syndrome, attention deficit disorder, autism, schizophrenia, dementia, etc.). Specific Disorders Aphasia is a communication disorder in which patients may have deficits in producing or comprehending verbal spoken or written messages. There are two main types of aphasia: Broca’s aphasia (usually caused by damage toward the front of the brain), where patients can comprehend and say short sentences, and Wernicke’s aphasia (usually caused by damage to the middle left side of the brain), where patients do not comprehend spoken language well and speak in long, complex sentences which include many incorrect or unnecessary words or are wholly senseless. In the United States, about 1 million people currently have aphasia. Apraxia of speech is a speech disorder in which patients have difficulty saying what they want to say coherently and correctly. There are two main forms of speech apraxia: the acquired form (caused by brain damage, which may result from head injuries, brain� tumors��������������������������������������������� , etc.) and the developmental form (which occurs in children and is probably linked with genetic factors). Apraxia of speech affects about 1–10 in 10,000 children. Articulation disorders are speech disorders in which patients place their tongue, lips, and so forth,
Disorders can range from a few errors, such as in uttering speech sounds, to a total loss of the ability to effectively communicate.
in wrong ways: this causes substitutions of one or more sounds with others, additions and omissions (for instance, affected people may say “thing” instead of “sing,” “sink” instead of “sick,” and “cool” instead of “school”). These errors affect the clarity of the speech, and in severe cases, they can render the speech almost unintelligible. The prevalence is estimated in about 2 percent of 8-year-old children. Developmental expressive language disorder provokes lack of vocabulary in affected subjects, and scarce ability in the production of complex sentences and recall of words. Causes may be cerebral damage and malnutrition as well as genetic factors. About 3 to 10 percent of all school-age children have this disorder. Disfluent speech includes stuttering and cluttering. Stuttering is a speech disorder in which the flow of speech is interrupted by hesitations, stops, repetition, or prolongation of sounds, syllables, words, or phrases. Stuttering occurs most frequently in children and teenagers, while it is estimated that less than 1 percent of adults stutter; the male-to-female ratio is about 3:1. Cluttering is a language disorder which alters the rhythm of speech, making it strange and jerky; affected subjects, who are often unaware of their problems, speak in bursts, pausing in unexpected ways. Causes of disfluent speech may be neurogenic (the disorder can be provoked by signal problems between the brain and oral muscles), psychogenic (the disorder can be a result of severe mental stress), developmental, or genetic.
Spider Bites
Language-based learning disabilities (one of which is dyslexia) cause difficulties in reading, spelling, and/ or writing. These disabilities, which seem hereditary, are linked with abnormalities in the brain structure. The prevalence is estimated in about 9 percent of 10year-old children. Spasmodic dysphonia (also called “laryngeal dystonia”) is a voice disorder characterized by involuntary spasms or movements of the vocal cords, which stiffen and slam together, giving origin to strained or strangled sounds, or remain open, producing weak and whispery sounds. Spasmodic dysphonia most often affects women between 30 and 50 years. Researchers estimate that 10,000 to 30,000 individuals are affected in the United States. In many of these disorders, effective treatments are provided by speech-language pathologists who work closely with the patients’ families, teachers, psychologists, audiologists, and physicians of various specialities (e.g.,����������������������������������������� pediatricians��������������������������� , neurologists, otoryngologists, physiatrists, etc.). These professionals can use different, individually tailored approaches, such as breathing techniques, relaxation strategies, oral-motor drills, and exercises. In severe cases, patients can communicate with their environment using formal or informal sign language, picture boards, and/or electronic communication devices. SEE ALSO: Autism; Head and Neck Cancer; Muscular
Dystrophy; Myasthenia Gravis; Neurologic Diseases; Voice Disorders.
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humans. A few species are capable of causing necrotic wounds and, occasionally, death. The only spiders of real medical importance to humans in the United States and in other countries are the Loxosceles and Latrodectus species, primarily the brown recluse and the black widow, respectively. These spiders bite humans only when trapped or crushed against the skin. Bite marks from most spiders are usually too small to be easily seen. Frequently, the patient will not recall being bitten. Spiders rarely bite more than once, so multiple bites are usually caused by insects such as fleas, bedbugs, ticks, mites, and biting flies. Spider bites often cause minor swelling, redness, pain, and itching. These mild reactions are common and may last from a few hours to a few days. Unfortunately, sometimes more severe reactions to bites or stings can be produced by spider bites. Babies and children may be more affected by bites or stings than adults. Taxonomically, spiders belong to class Arachnida which is composed by the orders Scorpionida, Acarina, Opiliones, Pseudoscorpiones, and Araneida. These arthropods belong specifically to the last order which is constituted for a large number of families. SEE ALSO: Immunology; Toxicology. BIBLIOGRAPHY. Harold Brown, Clinical Parasitology (Appleton-Century-Crofts, 1983); Gordon Cook and Alimuddin Zulma, Manson’s Tropical Diseases (Saunders, 2003);
BIBLIOGRAPHY. Dorothy V. M. Bishop and Lawrence
Leonard, eds., Speech and Language Impairments in Children (Psychology Press, 2000); Skye McDonald, et al., Communication Disorders Following Traumatic Brain Injury (Psychology Press, 1999).
Alessandra Padula, Ph.D. L’Aquila University
Spider Bites Spiders are dangerous to humans when the former accidentally bite the latter. About 20 species of spiders are known to cause dangerous envenoming of
Spider bites are usually too small to be easily seen, and often cause minor swelling, redness, pain, and itching.
1590 Spina Bifida James H. Diaz, “The Global Epidemiology, Syndromic Classification, Management, and Prevention of Spider Bites,” American Journal of Tropical Medicine and Hygiene (v.71/2, 2005); David Feliciano, Trauma (Appleton & Lange, 1996); Geoffrey K. Isbister, et al., “Spider Bites: Addressing Mythology and Poor Evidence,” American Journal of Tropical Medicine and Hygiene (v.72/4, 2005); NAEMT, Pre-Hospital Trauma Life Support (Mosby, 1999); Alcides Zambrano, et al., “Severe Loxoscelism with Lethal Outcome,” Revista Medica de Chile (v.133/2, 2005). Alfonso J. Rodriguez-Morales, M.D., M.Sc. Universidad de Los Andes Carlos Franco-Paredes, M.D., M.P.H. Emory University
Spina Bifida Spina bifida (SB) refers to protrusion of the spinal contents through a bony defect in the spine. The abnormality probably results from maldevelopment at the fourth week of gestation: the bony sheath surrounding the spinal cord does not form properly due to failure of the posterior vertebral arches to close. Although the spinal opening can be surgically repaired shortly after birth, the nerve damage is permanent, resulting in varying degrees of paralysis of the lower limbs. Even when there is no lesion present, there may be improperly formed or missing vertebrae and accompanying nerve damage. In addition to physical and mobility difficulties (such as congenital scoliosis, kyphosis, and hip deformities), most individuals have some form of learning disability. SB may also cause bowel and bladder complications, and many children with SB have hydrocephalus (excessive accumulation of cerebrospinal fluid in the brain). SB is one of the most common birth defects, with an average worldwide incidence of one to two cases per 1,000 births, but certain populations have a significantly greater risk. In the United States, the average incidence of SB is 0.7 per 1,000 live births. The incidence is higher on the East Coast than on the West Coast, and higher in Caucasians (one case per 1,000 live births) than in African Americans (0.1–0.4 case per 1,000 live births). Immigrants from Ireland have
a higher incidence of spina bifida than do nonimmigrants. This corresponds to the fact that the highest incidence rates worldwide are found in parts of the British Isles, mainly Ireland and Wales, where three to four cases of myelomeningocele per 1,000 population have been reported, along with more than six cases of anencephaly (both live births and stillbirths) per 1,000 population. The reported overall incidence of myelomeningocele in the British Isles is 2 to 3.5 cases per 1,000 births. The three most common types of SB are myelomeningocele, the severest form, in which the spinal cord and its protective covering (the meninges) protrude from an opening in the spine; meningocele in which the spinal cord develops normally but the meninges protrude from a spinal opening; and occulta, the mildest form, in which one or more vertebrae are malformed and covered by a layer of skin. Ten to 15 percent of spinal defects are closed by normal skin covering the bony defect. The remainder are open and most are detectable by maternal serum alphafetoprotein screening. Approximately 80 percent of lesions occur in the lumbar, thoracolumbar, or lumbosacral areas of the spine, with the remainder in the cervical and sacral areas. Prenatal Detection The diagnostic sensitivity of prenatal sonography for early detection of the site and extent of the spinal lesion is important because these features correlate with neurologic outcome; more severe neurologic dysfunction is associated with higher and larger lesions. Spina bifida can be detected before the 12th postmenstrual week by noting irregularities of the bony spine or a bulging within the posterior contour of the fetal back. After the 12th postmenstrual week, well-established additional sonographic findings (e.g., lemon sign, banana sign, and hydrocephaly) facilitate detection. A detailed scan of the spine in the sagittal and transverse planes is indicated if these cranial findings have been observed. Treatment There is no cure for SB because the nerve tissue cannot be replaced or repaired. Treatment for the variety of effects of SB may include surgery, medication, and physiotherapy. Many individuals with SB will need assistive devices such as braces, crutches, or
wheelchairs. Ongoing therapy, medical care, and/or surgical treatments may be necessary to prevent and manage complications throughout the individual’s life. Surgery to close the newborn’s spinal opening is generally performed within 24 hours after birth to minimize the risk of infection and to preserve existing function in the spinal cord. Prevention Normally, the closure of the neural tube occurs around the 30th day after fertilization. However, if something interferes and the tube fails to close properly, a neural tube defect will occur. Teratogens such as vitamin A can interfere with closure of the neural tube, as can hyperthermia. Research has shown that lack of folic acid (folate) is a contributing factor in the pathogenesis of neural tube defects, including spina bifida. Supplementation of the mother’s diet with folate can reduce the incidence of neural tube defects by about 70 percent, and can also decrease the severity of these defects when they occur. At this time, however, it is unknown how or why folic acid has this effect. Conversely, if the mother takes valproic acid, a common antiseizure drug which is also a folate antagonist, there is an increased risk of spina bifida in the child. Women with insulin-dependent diabetes have a higher chance of having a child with a neural tube defect. Spina bifida does not follow direct patterns of heredity like muscular dystrophy or hemophilia. Studies show that a woman who has had one child with a neural tube defect such as spina bifida have about a 3 percent risk to have another child with a neural tube defect. Because there is a high prevalence of karyotypic abnormalities among fetuses with neural tube defects, karyotyping should be offered as a means of prevention. SEE ALSO: Developmental Disabilities; Folic Acid; Hip In-
juries and Disorders; Hydrocephalus; Learning Disorders; Neural Tube Defects; Paralysis; Scoliosis.
BIBLIOGRAPHY. P. Cotton, “Finding Neural Tube ‘Zip-
pers’ May Let Geneticists Tailor Prevention of Defects,” Journal of the American Medical Association (v.270/14, 1993); R. J. Lemire, ������������������������������� “Neural Tube Defects,” Journal of the American Medical Association (v.259/4, 1988); R. J. Morrow, et al., “Ultrasound Detection of Neural Tube
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Defects in Patients with Elevated Maternal Serum AlphaFetoprotein,” Obstetrics and Gynecology (v.78, 1991); K. H. Nicolaides et al., “Ultrasound Screening for Spina Bifida: Cranial and Cerebellar Signs,” Lancet (v.2, 1986); C. Penso, et al., “���������������������������������������� A Sonographic Sign which Predicts which Fetuses with Hydrocephalus Have an Associated Neural Tube Defect,” Journal of Ultrasound in Medicine (v.6, 1987); N. J. Sebire, et al., “Presence of the ‘Lemon’ Sign in Fetuses with Spina Bifida at the 10–14-Week Scan,” Ultrasound in Obstetrics & Gynecology (v.10, 1997); S. Thiagarajah, et al., “Early Diagnosis of Spina Bifida: The Value of Cranial Ultrasound Markers,” Obstetrics and Gynecology (v.76, 1990); J. Volpe, “Neuronal Proliferation, Migration, Organization and Myelination,” Neurology of the Newborn (Saunders, 1995). Barkha N. Gurbani UCLA School Of Medicine
Spinal Cord Diseases The spinal cord is the connection between the brain and all muscles of the body, with the exception of the cranial nerves to the head and neck. The spinal cord can be damaged in many ways, producing various symptom patterns. These patterns enable a doctor to determine the location, or level, of spinal cord damage. The spinal cord can be cut in an accident, compressed, destroyed by infection, damaged when its blood supply is cut off, or affected by diseases (such as spinal cord cysts, cervical spondylosis, or multiple sclerosis) that alter its nerve function. Considerable differences exist in terms of clinical complications after traumatic and nontraumatic spinal cord injury (SCI). Spinal cord disease, especially compression of the long tracts, may lead to an unpleasant sensation in the extremities that also is enhanced by increased intraspinal pressure or movements that stretch the cord (e.g., neck flexion, straight leg raising). Neck or back pain may also be conspicuous. The associated signs vary with the extent of the lesion and speed of its development. Acute cord compression, as from an epidural hemorrhage, is associated with pain and the rapid onset of a paraparesis or quadriparesis that may not be reversed by decompressive surgery. In contrast, a gradually evolving compressive lesion may be
1592 Spinal Cord Diseases painless and leads to a slowly progressive deficit that often recovers after decompression. Laterally placed lesions lead to a Brown-Séquard syndrome, posterior lesions to bilateral posterior column dysfunction with impaired position and vibration appreciation, anterior lesions to weakness, and intramedullary lesions to a dissociated sensory loss, with impairment of pain and temperature appreciation and preservation of posterior column sensation. herniation With advancing years, the nucleus pulposus of the intervertebral discs becomes harder, less resilient, and more susceptible to trauma. Tears tend consequently to develop in the annulus, through which a portion of the nucleus pulposus may herniate. Herniation is generally in a lateral direction and may lead to compression of the nerve roots as they enter the intervertebral foramina, but sometimes occurs centrally, so that the spinal cord or cauda equina is compressed. In some instances, the protruded disc material loses its continuity with the nucleus pulposus and becomes a free fragment within the spinal canal. Disc herniations occur most commonly in the lumbosacral or cervical region. The early recognition of thoracic disc herniations is important, however, because there is only limited space in the thoracic portion of the spinal canal and delay in diagnosis may lead to an irreversible myelopathy. Protrusion of an intervertebral disc may lead to a radiculopathy. Approximately two-thirds or more of all compressive root lesions involve the lumbosacral roots. The L5 and S1 roots are involved most commonly. Multiple lumbosacral radiculopathies may occur with protrusion of a single intervertebral disc that compresses the roots as they descend in the cauda equina. Lumbosacral polyradiculopathies may also result from spinal stenosis, and in rare instances, from lateral disc protrusion, but bilateral involvement is then often asymmetrical. Lumbar spinal stenosis is an important cause of disability in middle-aged or elderly patients. Superimposed minor disc disease then leads to symptoms that may be disabling. The disorder can be congenital or acquired. The congenital disorder is caused by a reduction in the normal dimensions of the spinal canal and occurs in achondroplastic dwarfs. Acquired lumbar stenosis usually is caused by degener-
ative disease of the spine and is typically associated with hyperplasia, fibrosis, and cartilaginous changes in the annulus, posterior longitudinal ligament, and ligamentum flavum. Spondylolisthesis (i.e., anterior or posterior displacement of one vertebral body on the next) or spondylolysis, a defect in the pars interarticularis, may contribute to spinal stenosis, as may other anatomic abnormalities. Acquired stenosis may also be related to injury, bony overgrowth such as occurs in Paget’s disease, ankylosing spondylitis, rheumatoid arthritis, and diffuse idiopathic skeletal hyperostosis. Patients present with pain that is brought on by activity and released by rest or leaning forward. The pain involves the lower back and one or both legs, typically in a radicular distribution, and may be accompanied by numbness or weakness. An acute cauda equina syndrome occurs after spinal trauma or central lumbosacral disc protrusions. Patients may present with bilateral sciatica and saddle anesthesia; disturbances of bladder or bowel function are common and are characterized by frequency, retention, or incontinence. The normal sensation associated with the passage of urine or feces may be lost; impotence is common. Examination reveals bilateral root dysfunction and, often, perianal anesthesia and a lax anal sphincter. Investigations involve urgent imaging to define any surgically remedial lesion. The cervical nerve roots occupy about 30 percent of the space in the intervertebral foramina that they traverse, accompanied by radicular vessels. Roots may be compressed by a protruded intervertebral disc or by pathology involving the facet joint or joints of Luschka. Disc herniation is the most common cause and occurs especially at the C5-6 and C6-7 levels, affecting the C6 and C7 roots, respectively. Cervical spondylosis is a common cause of dysfunction in patients older than 55. Typically, there is bulging or herniation of intervertebral discs, with osteophytes and ligamentous hypertrophy that is sometimes accompanied by subluxation. The underlying primary pathology is usually degenerative disease of the intervertebral discs. This is followed by reactive hyperostosis, with osteophyte formation related to the disc and adjacent vertebral bodies, as well as the facet joints and joints of Luschka. Other associated pathologic factors include thickening of
the ligamentum flavum, disc herniation, and a congenitally narrow spinal canal. Ischemia of the cord or roots from compression or distortion of small blood vessels may contribute to the neurologic deficit. Compression of the spinal cord or nerve roots may occur in consequence of inflammatory diseases. Cord or root involvement may occur in spinal osteomyelitis or tuberculosis, acute or chronic meningitis, inflammatory diseases such as sarcoidosis, and the connective tissue diseases. When the inflammatory process involves the subarachnoid space, root involvement is often multifocal and difficult to explain on the basis of a lesion at one site or level. Multiple sclerosis Multiple sclerosis is a disorder characterized by involvement of different regions of the central white matter at different times by an inflammatory process. The disorder commonly begins in young adult life and may follow a chronic, progressive, or a relapsing and remitting course. Clinical onset is usually with the acute development of a focal neurologic deficit that worsens progressively over several days and then shows partial or complete remission over several weeks or longer. After a variable interval of a few days to many years, another attack occurs. With succeeding attacks, remission is often incomplete, so that patients are left with a neurologic deficit that becomes increasingly severe as further attacks occur. In most patients, signs of a progressive myelopathy become increasingly conspicuous with advancing disease. Eventually, the spinal cord may become atrophic. Progressive necrotizing myelopathy may occur at any age, but is seen especially in young adults, usually after an infectious illness, or in patients with a known malignancy, usually small-cell cancer of the lung or lymphomas such as Hodgkin’s disease. Typically, patients present with pain in the back or legs, sometimes accompanied by paresthesias. The legs then become weak and eventually paralyzed. The tendon reflexes are often lost initially, but after a variable interval, spasticity and hyperreflexia develop. Sensory deficits may be conspicuous, and sphincter disturbances are usual. The disorder follows a progressive course leading eventually to respiratory disturbances and bulbar signs. Ischemia may contribute to the neurologic deficit that occurs in patients with space-occupying le-
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sions, and those with posttraumatic or postirradiation myelopathies. Wasting of the intrinsic muscles of the hands may result from compression of the anterior spinal artery in patients with lesions of the foramen magnum. Disease of the abdominal aorta may cause an ischemic myelopathy. Aortic occlusion, dissecting or nondissecting aortic aneurysms, inflammatory aortitis, and emboli involving the aorta may all lead to cord dysfunction, as may surgery involving the aorta, especially in the region of origin of the artery of Adamkiewicz. Severe hypotension from any cause has been associated with an ischemic myelopathy. The cord is involved particularly in the watershed regions where the anterior spinal artery is most remote from segmental feeding vessels. Some physicians regard the mid-thoracic region as being especially vulnerable to such ischemia. Venous infarction of the cord occurs most commonly in association with an arteriovenous malformation, but occasionally in association with sepsis, malignant disease, or vertebral disorders. Sudden back pain heralds the onset of weakness and sensory loss in the legs, with accompanying retention of urine and feces. The deficit may progress over the next few days to that of an acute transverse myelopathy, and a fatal outcome is common. Embolism of nucleus pulposus material has been reported, particularly in women, who present with acute neck or back pain followed, within a few minutes, by rapidly progressive limb weakness and sensory loss to all modalities. The cervical region is affected most commonly. Hematomyelia (i.e., hemorrhage into the spinal cord) or spinal subarachnoid hemorrhage may occur from trauma, spinal vascular malformations, intradural spinal neoplasms, coarctation of the aorta, or ruptured spinal aneurysms. It may be associated with connective tissue diseases, blood dyscrasias, or anticoagulant therapy. In some instances, no cause can be identified. Spinal subarachnoid hemorrhage is heralded by the onset of sudden severe pain that begins at the site of bleeding but spreads rapidly to the rest of the back and, with cervical lesions, to the head. Spinal subdural hemorrhage may occur spontaneously or after trauma or lumbar puncture, especially in patients with blood dyscrasias or those receiving anticoagulant drugs. Sudden severe back pain is fol-
1594 Spinal Cord Injuries lowed by a compressive myelopathy or cauda equina syndrome. Spinal epidural hemorrhage results most commonly from trauma but also occurs in patients with epidural vascular malformations or tumors or with hemorrhagic disorders. SEE ALSO: Diagnostic Imaging; Spinal Cord Injuries. BIBLIOGRAPHY. S. J. Atlas and R. A. Nardin, “Evaluation
and Treatment of Low Back Pain: An Evidence-Based Approach to Clinical Care,” Muscle Nerve (v.27, 2003); R. A. Deyo and J. N. Weinstein, “Low Back Pain,” New England Journal of Medicine (v.344, 2001); D. Ellison, et al., Neuropathology. A Reference Text of CNS Pathology, 2nd ed. (Mosby, 2004); J. G. Jarvic and R. A. Deyo, “Diagnostic Evaluation of Low Back Pain with Emphasis on Imaging,” Annals of Internal Medicine (v.137, 2002); “Review of the yield of various diagnostic tests.” Goldman: Cecil Textbook of Medicine, 22nd ed. (Saunders, 2004); P. C. Vroomen, et al., “Lack of Effectiveness of Bedrest for Sciatica,” New England Journal of Medicine (v.340, 1999). Barkha N. Gurbani UCLA School Of Medicine
Spinal Cord Injuries Spinal cord injury (SCI) is most commonly caused by traumatic forces that compress or fracture vertebrae, which can release fragments that tear into spinal cord tissues. Nontraumatic injuries can also occur from diseases, such as cancer and arthritis. SCI affects nerves and muscles below the site of injury, and severity can range from mild sensory loss to complete paralysis The majority of traumatic spinal cord injuries occurs during motor vehicle accidents, but may also result from falls in the elderly, recreational injuries, and gunshot or knife wounds. Posttraumatic inflammation and swelling can further damage the nerve fibers of the cord. Causes of nontraumatic SCI include arthritis, infections, cancer, blood vessel abnormalities, and vertebral disc degeneration. SCI can either be incomplete, when sensory-motor functions are not fully lost, or complete, in which there is an absence of sensation and movement below the
level of injury. Paralysis can affect all four extremities (quadriplegia) or just the lower limbs (paraplegia). Approximately 80 percent of SCI patients are male, and injuries are most common in young adults because of vehicle accidents and the elderly from traumatic falls. People engaged in high-impact sports and people with predisposing conditions, such as osteoporosis, are also at a higher risk of SCI injury. Symptoms and Diagnosis Symptoms in patients with SCI depend on severity and location of the injury. Complete injuries cause more paralysis, as do injuries higher in the spinal cord. Symptoms include intense pain in the back or neck, loss of movement, tingling or loss of sensation, balance problems, amplified reflexes and muscle spasms, bladder and bowel control problems, and changes in sexual function. Loss of consciousness and breathing difficulties may also indicate severe spinal damage. Emergency cases are diagnosed using X-rays and computerized tomography (CT) to check for bone and disc degenerative changes. Magnetic resonance imaging (MRI) and myelography also illustrate spinal nerves, blood clots, and masses more accurately. Patients should be followed each month with repeated neurological examinations and spine imaging to forestall further complications. Complications SCI can lead to chronic pain, urinary and fecal incontinence, sexual dysfunction, infertility, kidney infections, and muscle spasticity. Lying for long periods in bed can cause painful pressure sores and puts the patient at risk for deep vein thrombosis or lethal blood clots that can travel to the lungs. Weak respiratory muscles cause breathing difficulties and recurrent pneumonia. Another phenomenon known as autonomic dysreflexia can result in seizures or strokes. SCI patients undergo muscle atrophy and later gain weight because of lifestyle changes. The psychological stress caused by SCI can also lead to depression and alcohol abuse. Treatment SCI can be prevented by driving safely, avoiding falls, and wearing proper protection during athletic activities. The goals of treating SCI are to allow patients to enjoy an active, fruitful life and to prevent com-
plications from further injury. Emergency medical personnel first respond to acute injuries by immobilizing the spine with a rigid board and neck collar. A steroid drug that reduces tissue inflammation, methylprednisolone, can prevent further nerve damage in some patients if given within eight hours of injury. Although emergency surgery is controversial, some surgeons may remove bone fragments and herniated discs endangering the spinal cord. Ongoing care includes medications to treat chronic pain, sexual dysfunction, and bowel/bladder incontinence. Additionally, physical therapy allows patients to redevelop muscle strength, and psychological counseling can help patients cope with and adapt to their disabilities. Modern wheelchairs and computer-assisted technologies allow patients greater independence. Prognosis and Research Many patients with partial spinal cord injuries improve significantly during the first 12 to 24 months, but any remaining symptoms after two years are considered permanent. The National Institute of Neurological Disorders and Stroke (NINDS) is currently researching new, innovative therapies, prostheses, and medications that may enhance nerve regeneration. Advances in physical rehabilitation techniques and stem cell research offer tremendous hope for patients with SCI.
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SEE ALSO: Arthritis; National Institute of Neurological
Disorders and Stroke (NINDS); Neck Disorders and Injuries; Neurologic Diseases (General); Spinal Stenosis. BIBLIOGRAPHY. National Institute of Neurological Disorders, “Spinal Cord Injury Information Page,” www.ninds. nih.gov (cited November 2006); Sandrine Thuret, et al., “Therapeutic Interventions after Spinal Cord Injury,” Nature Reviews Neuroscience (v.7, 2006).
Anjan P. Kaushik Francis H. Shen, M.D. University of Virginia Dino Samartzis, D.Sc., M.Sc., Dip. EBHC Harvard University and Erasmus University
Spinal Muscular Atrophy Spinal muscular atrophy (SMA) is a collective term that encompasses a range of genetic neuromuscular disorders that involve the motor neurons in the brain stem and spinal cord. It represents one of the most common autosomal recessive disorders, appearing with an incidence of one in 6,000 to 10,000 and a carrier frequency of one in 40 to 60. The rate incidence is similar in various populations. Causes The majority of these disorders are caused by mutations in the survival motor neuron (SMN) gene mapped to chromosome 5q13. Humans possess two nearly identical copies of the gene, labeled SMN1 and SMN2. Approximately 95 percent of individuals with spinal muscular atrophy possess a deletion in SMN1. The SMN gene is linked to the production of a protein crucial to the function of motor neurons. Because the disorder is autosomal recessive, both parents must be carriers of the mutated gene in order to pass it to their children.
Advances in physical rehabilitation techniques and stem cell research offer tremendous hope for patients with SCI.
Symptoms SMA is characterized by the loss of lower motor neurons in the anterior horn cells of the spinal cord, inducing the atrophy of proximal muscles in the limbs and trunk. The impact to muscles closest to the trunk of one’s body, which includes the shoulders, hips, and
1596 Spinal Stenosis back, is most severe. Patients usually experience more weakness in the legs than in the arms. This weakness makes it difficult to perform such daily activities as sitting, standing, and walking. The disorder has also been implicated in a variety of lung problems, as certain respiratory muscles can also be affected. As the disease is degenerative, patients lose function progressively, ultimately leading to paralysis. However, muscle power often remains stabilized while only functional abilities decline. The patient’s deteriorating condition is often explained by the fact that muscles experience greater demand from the body as the patient grows in size and/or weight. With differing clinical and genetic factors, the disorders are classified into four main types based on the age of onset and severity. The four types of spinal muscular atrophy are acute, intermediate, mild, and adult—also recognized as types I, II, III, and IV, respectively. Types I to III occur during childhood, while type IV is adult onset. Type I SMA, also known as Werdnig-Hoffman disease, is described as onset within the first six months of a child’s life. Some cases even indicate decreased movement during the final months of pregnancy. Children with this disorder experience abnormal muscle weakness, leading to the incapability for head control, walking, and sitting without assistance. Many children also have difficulty feeding and swallowing. Respiratory problems are also prevalent because the lung muscles never develop, and the child typically engages in diaphragmatic breathing. The average life span for a child with the disorder is eight months. Type II SMA is less severe, with children able to sit unaided. However, patients still suffer respiratory problems, floppiness of the limbs, and very rarely gain the ability to stand. These children are almost always diagnosed within reaching 2 years of age. Life expectancy is variable. Patients with type III SMA, also known as Kugelberg-Welander disease and juvenile spinal muscular atrophy, varies in age of onset between age 3 to adolescence. These children can stand and walk alone, although in an abnormal manner. Many lose the ability to walk later on, typically linked to growth spurts or illness. These patients also possess an increased risk of scoliosis and obesity. Some clinicians also designate a type IV SMA, referring to adult onset SMA. It is the least common
form. Muscle atrophy typically begins between the ages of 18 and 30, while patients do not experience symptoms until the age of 30. Respiratory muscles are rarely affected in type IV SMA. Diagnosis and treatment SMA is diagnosed through a blood test that examines the SMN1 gene in addition to clinical findings. Older methods such as muscle biopsies and electrophysiologic techniques are rarely used today, although they are occasionally utilized in cases where the blood test is negative. Because there is no cure for spinal muscular atrophy, patients receive symptomatic and supportive treatment. Physical and occupational therapy, orthotic supports, and rehabilitation are normally used to expand the patient’s physical abilities. Children with trouble swallowing are sometimes given feeding tubes. Those with trouble breathing can be put on respirators or ventilators, although this sort of treatment is rare in the United States because of the high burden of care and low quality of life. Both the quality and duration of life are factored into treatment for children with type I and type II SMA. SEE ALSO: Genetic Disorders; Muscle Disorders.
Thomas Crawford, “Spinal Muscular Atrophies,” in H. R. Jones, et al., eds., Neuromuscular Disorders of Infancy, Childhood, and Adolescence (Butterworth-Heinmann, 2002); FSMA’s Medical Advisory Board “Understanding Spinal Muscular Atrophy,” Families of Spinal Muscular Atrophy (Families of SMA, 2005); M. K. M. Hardart and R. D. Truog, “Spinal Muscular Atrophy—Type 1,” Archives of Disease in Childhood (v.88, 2003); Sophie Nicole, et al., “Spinal Muscular Atrophy: Recent Advances and Future Prospects,” Muscle & Nerve (v.26, 2002). BIBLIOGRAPHY.
Neha Sathe New York University
Spinal Stenosis Spinal stenosis is one of the most common conditions that affect the aging population, with an increased prevalence with the progression of age. The
word “stenosis” is derived from the Greek word stenos, which means “a narrowing.” Therefore, spinal stenosis can occur throughout the spinal column, mainly noted in the lower lumbar region, and is regarded as a narrowing of the spine’s spinal canal, lateral recess, or intervertebral neural foramen. Such a narrowing of these anatomical structures can lead to compression of the spinal cord and/or exiting nerve roots, and subsequently the manifestation of symptoms. The development of spinal stenosis is attributed to a variety of factors that alter the natural structure and function of the spinal column, leading to morphological alterations contributing to spinal stenosis. Spinal stenosis is categorized as being acquired or congenital. In acquired spinal stenosis, the condition is due to changes attributed to intervertebral disc (“shock absorbing” tissue between vertebrae) and/or facet (articulating processes between vertebrae) degeneration, metabolic alterations, post-traumatic event, spondylolytic spondylolisthesis, or iatrogenic causes. Conversely, in congenital spinal stenosis, the condition is considered idiopathic or present in achondroplastic dwarfs. However, the most common impetus leading to spinal stenosis is attributed largely to intervertebral disc and/or facet degeneration. Clinically, there is no universal consensus as to what is deemed anatomically as spinal stenosis. The reason being is that individuals can undergo a variety of stenotic alterations and present with varying degrees of clinical manifestations. Symptoms can vary and as such demand thorough assessment of the patient’s history, physical examination, differential diagnosis, and advanced imaging to determine the location and extent of spinal stenosis and in turn to devise the proper course of management. In individuals with acquired spinal stenosis, symptoms occur later in life, whereas individuals with congenital spinal stenosis present with symptoms much earlier in life (3rd or 4th decades). In central canal stenosis of the lumbar spine (occurring mainly at the level of the intervertebral disc), neurogenic claudication is predominantly noted, whereas radicular symptoms with or without back pain is largely associated with lateral recess or foraminal stenosis. Symptoms may entail pain, numbness, motor weakness, burning, cramping, tingling, and dysreflexias of the lower extremities.
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In lumbar stenosis, symptoms are exacerbated while standing and walking, but improve, in less severe cases, when laying down, sitting, or when the spine is in the flexed position. In contrast, symptoms are aggravated when sitting or in spinal flexion in individuals with degenerative disc disease or a herniated disc of the lumbar spine. In the early stages of spinal stenosis and dependent on the etiology of the condition, conservative treatment (i.e. activity modification, aerobic exercises, physical therapy, epidural steroid injections, selective nerve blocks, medication) can help alleviate the symptoms. Surgical options to resolve symptoms associated with spinal stenosis are available; however, the choice to pursue such intervention is dependent on the location and extent of pathology, the degree and type of symptoms, the affects upon the patient’s quality of life, response to conservative treatment, co-morbidities, and the ability to undergo surgery. Nonetheless, due at times to the severity of spinal stenosis, surgical management of this disease process may not yield desirable neurologic recovery. SEE ALSO: Neck Disorders and Injuries; Orthopedist. BIBLIOGRAPHY. Howard S. An and Jerry P. Butler, “Lum-
bar spinal stenosis: historical perspective, classification, and pathoanatomy,” Semin Spine Surg (v.11, 1999); William Kirkaldy-Willis and George W.D. McIvor, “Spinal stenosis,” Clin Orthop (v.115, 1976); Kern Singh, et al., “Congenital lumbar spinal stenosis: a prospective, control-matched, cohort radiographic analysis,” Spine J (v.5, 2005). Dino Samartzis, DSc, MSc, Dip. EBHC Harvard University and Erasmus University, Francis H. Shen, MD University of Virginia
Spleen Diseases The spleen is an organ located in the upper left side of the abdomen, just behind the stomach and below the diaphragm. Until recently, scientists weren’t quite sure the exact function of this organ. We now know it serves to help in the removal of old or damaged red blood cells as well as assist the immune system
1598 Spleen Diseases in protecting our body from infections, both viral and bacterial. The spleen does this by filtering blood through a series of complicated sinuses and capillaries, removing old and damaged red blood cells from circulation. Foreign compounds like bacteria come in contact with lymphoid (immune system) tissue inside the spleen and activate the rest of the immune system as well as being removed from the body. The spleen may be predisposed to a certain set of diseases because of its function, mainly a problem called splenomegaly, or enlargement of the spleen. Splenomegaly can be caused by quite a few problems, ranging from insignificant to extremely serious and life threatening. Some of the causes of splenomegaly are infection, hematologic disorders, congestive splenomegaly, storage diseases, and others. Infection is the most common cause of splenomegaly, and can be acute or chronic depending on the etiology of the infection. Acute splenomegaly can be caused by a bacterial abscess, brucellosis, infectious mononucleosis, cytomegalovirus, or typhoid fever. Basic medical work-up of acute splenomegaly should include a complete blood count with differential, platelet count, reticulocyte and atypical lymphocyte counts. It is important to rule out more serious causes of acute splenomegaly such as hemolytic anemias and leukemia. Chronic splenomegaly can be caused by echinococcosis, histoplasmosis, malaria, syphilis, or tuberculosis. The hematologic disorders that can cause splenomegaly are hemolytic anemias, thalassemias, sickle cell disease, leukemias, lymphomas, multiple myeloma, myelofibrosis, polycythemia vera, structural hemoglobinopathies, or thrombocytopenic purpuras. Congestive splenomegaly can be caused by cirrhosis of the liver, stenosis of the splenic vein, portal vein, or hepatic vein, and heart failure. The spleen is enlarged because blood cannot be removed efficiently because of increased pressure in the venous draining system. Storage diseases that cause enlargement of the spleen are Gaucher’s disease, Niemann-Pick disease, and mucopolysaccharidoses. These storage diseases manifest by an excess amount of fat or carbohydrates being deposited in the spleen, reducing its ability to function properly. Some other common causes of splenomegaly are amyloidosis, berylliosis, Felty’s syndrome, Graves’ disease, histiocytosis X, sarcoidosis, or systemic lupus erythematosus.
There are a few treatments of splenomegaly. The first stage in treatment is trying to reduce the symptoms associated with the diseases that cause the spleen to be enlarged in the first place. This may include the administration of antibiotics, antimalarials (hydroxychloroquine), corticosteroids, immunosuppressant, blood transfusion, chemotherapy, enzyme replacement therapy, or even surgical intervention may be necessary. If these don’t help resolve the splenomegaly it may be necessary to completely remove the spleen, this procedure is called splenectomy. Once the spleen is removed, the patient is considered immunocompromised and should be put on prophylactic oral antibiotics for life. Cysts and tumors may also cause diseases of the spleen. Cysts are infrequent and they usually don’t cause much of a problem except for diminished function due to lack of normal tissue. Tumors of the spleen are not very common either, but if they do occur, they may cause serious problems. The most common tumors that are associated with the spleen are neoplasms of the hematopoietic system that involve the spleen like leukemias or lymphomas. Metastatic carcinomas from other areas in the body may spread to the spleen and form tumors there. Neoplasms that originate in the spleen are uncommon. These may be mesenchymal tumors, hemangiomas, hemangiosarcomas, hamartomas, or hemangioendotheliomas. Most of these tumors are vascular in origin and may be either benign or malignant. Treatment of these tumors includes surgical resection of the tumor along with the spleen, radiotherapy, or chemotherapy. Hemangiosarcomas are the most malignant of these tumors and are typically lethal despite treatment with both chemotherapy and splenectomy. Trauma and rupture is also a common problem associated with the spleen. If the spleen obtains trauma such as a sudden blow from a blunt object, a stab wound through the abdomen, or damage from the seat belt of a car during an automobile accident, the spleen is prone to rupture. There will be a tear through the capsule of the spleen and through the tissue of the spleen. This damage leads to intra-abdominal hemorrhage due to the high amount of blood flow in this organ. Usually the only treatment of this damage is to remove the spleen and prophylactically treat the patient with antibiotics because of subsequent higher risk of infections.
Sports Injuries
The spleen may be a relatively small and inconspicuous organ in the abdomen, but diseases of the spleen may be potentially life threatening. It is important to identify the disease causing due to possible medical interventions to prevent further complications. SEE ALSO: Hematology; Immune System and Disorders. BIBLIOGRAPHY. Galal M. Amer, “Portal Vein Haemody-
namics in Patients with Splenomegaly of Different Etiologies,” Menoufia Medical Journal (v.9, 1997); R.E. Brown, et al, “Health Survey of Primary Schoolchildren in Uganda: Incidence of Anemia, Splenomegaly, Hook-worm and Malaria,” East African Medical Journal (v.47, 1970); “The Rational Clinical Examination. Does this Patient Have Splenomegaly?” JAMA (v.270/18, 1993). Angela Garner, M.D. Ryan Strain University of Missouri–Kansas City
Sports Injuries Sports-related injuries cause over 2.5 million emergency room visits yearly. Overuse injuries are the most common type of these injuries; however, there are many other causes. By being aware of the potential causes, one may be able to prevent some of these injuries. Overtraining In a quest for excellence, athletes may push themselves beyond healthy limits. Signs of overtraining include, but are not limited to, the following: • Extreme muscle soreness the day after training • Gradual increase in muscle soreness • Inability to finish a regular training session • Increase in resting heart rate (pulse) in response to regular training • Increase in illnesses such as colds and flu In addition to the above, poor training techniques and lack of warming up and cooling down will contribute to an increase in sports injuries. Concussions Concussions are caused by sudden forces on the brain, due to head trauma. This is common in contact sports,
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such as football and soccer, and is characterized by sudden neurologic symptoms including changes in consciousness level or mental status, dizziness, and visual disturbances. Concussions are graded based on length of time, severity of symptoms, and the status of neurologic functioning. Based on recommendation of the Colorado Medical Society, Grade I includes some or all the symptoms lasting less than 15 minutes, Grade II when the symptoms last longer than 15 minutes, and Grade III when any loss of consciousness occurs for any length of time. A computed tomography (CT) scan is recommended for severe Grade II or any Grade III concussions. A very detailed evaluation should be performed on the athlete to ensure complete resolution of all symptoms before clearing the athlete to return to play; any return to play without complete resolution of symptoms will most likely result in second-impact syndrome. This is a second head trauma during the game, which may lead to brain swelling. The athlete will look stunned but conscious initially, then the pupils may dilate and respiratory failure ensues, leading to collapse and possibly death. Clavicular Fractures Clavicular fractures usually occur from trauma due to a fall where the arm is unable to protect the clavicle or from a direct blow. The most common area to fracture is the middle of the clavicle. If a fracture is suspected, loss of motion in the shoulder may be noted as well as a deformity of the clavicle or pain with arm/ shoulder motion. An X-ray may reveal clavicle fractures, which are classified based on region fractured. Fractures located other than the middle third of the clavicle should be referred to a specialist. Treatment usually includes placing a “figure 8” brace on the back for four weeks as well as gently progressive shoulder range of motion exercises. Return to full activity is achieved in about six weeks when shoulder strength and shoulder range of motion are mostly regained. Shoulder Dislocations Shoulder dislocations usually occur from falling onto an outstretched arm or trauma to the shoulder in a specific location. Ninety-five percent of the time, dislocations are anterior and usually result in a tear or stretch shoulder ligaments or the anterior joint capsule.
1600 Sports Injuries After the dislocation, the patient may have feelings of apprehension when moving the shoulder and arm, and there may be an obvious cleft in the upper shoulder. If a dislocation is suspected, checking the circulation and doing a neurological examination may reveal a lack of sensation of the back of the shoulder. Specialized X-rays may be necessary to evaluate the dislocation and rule out fractures of neighboring bones. Treatment includes reducing the dislocation by slow, steady, and strong traction pulling the affected arm forward and upward. Sedation, injections, and pain medications are sometimes necessary. Afterward, an X-ray should be performed to confirm the shoulder is back in the joint, and ice and a brief (one to two weeks) shoulder immobilization with a sling may help. Gentle range of motion exercises of the shoulder should begin as soon as possible to avoid a frozen shoulder. If the dislocation is not reduced, a specialist should be called immediately. Return to full function when strength and painless movement of the shoulder becomes possible. Rotator Cuff Tears Rotator cuff tears are best diagnosed by being aware of the anatomy—the rotator cuff consists of four muscles, the supraspinatus, infraspinatus, teres minor, and subscapularis, which hold the shoulder in place. Each of these muscles contributes to shoulder motion based on its attachment. The supraspinatus elevates the shoulder, the teres minor and infraspinatus create external rotation, and the subscapularis creates medial rotation. Symptoms indicative of a tear include weakness or pain when raising the shoulder, and tenderness to palpation over the anterior rotator shoulder area. Other symptoms include limited motion from weakness or pain, weak abduction (raising the arm), and external and internal rotation of the arm. Goals of shoulder rehabilitation include decreasing pain and improving strength and range of motion. Initially, placing ice every two hours for 15 minutes at a time for the first one to two days after the injury will help reduce swelling and pain. Use of transcutaneous electric nerve stimulation (TENS) modality, nonsteroidal antiinflammatory medication (NSAIDs) and pain medications will help with analgesia. Regaining range of motion can be achieved initially by pendulum or wall-climbing exercises. Isometric (muscle contraction without motion) exercises should be gently performed
before performing isometric resistance exercises (free weights). Successful treatment is heralded by return to painless full shoulder range of motion and return to most of preinjury strength. If these goals are not met, a referral to a specialist may be necessary. Subacromial Bursitis Subacromial bursitis is commonly due to shoulder overuse or weakness of the rotator cuff muscles. A bursa is a fluid-filled sac that is commonly located around joints. Inflammation and swelling (bursitis) is caused by irritation due to impingement and friction. This results in sharp shoulder pain with overhead activity. There may be nocturnal shoulder pain, limited range of motion, as well as uncomfortable sensations in the shoulder region and upper extremity weakness. An X-ray will rule out arthritis and calcification of the subacromial region. Reducing overhead work is necessary for healing. NSAID usage will help control swelling, but a steroid subacromial injection may be necessary. Rotator cuff muscle strengthening and rehabilitation will help keep the humeral head in proper position and function. A return of pain-free range of shoulder motion and near-full strength will signify completed healing, but prolonged activity restrictions may be needed if the bursitis recurs. Rotator Cuff Tendinosis Rotator cuff tendinosis is caused by overuse of the rotator cuff leading to tendon degeneration and dysfunction. Symptoms resemble those present with rotator cuff tears and include shoulder pain with overhead motion, restricted motion due to pain/weakness, tenderness over the anterior shoulder area, weak supraspinatus musculature, and weak external rotators. Impingement test may be positive. Biceps Tendonitis Biceps tendonitis is caused by inflammation of the biceps tendon due to overuse. Pain with overhead motion or resisted shoulder elevation, and anterior shoulder pain with extension are common. With arm movement, the long head of the biceps tendon is palpable and can be very tender. X-rays are typically normal. Treatment includes rest, decreasing overhead activity, pain medication, and physical therapy for biceps and rotator cuff muscles strengthening.
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pain with activity, occasional swelling and weakness of wrist forearm muscles, tenderness of the medial epicondyle, and pain with resisted wrist flexion and pronation. X-rays may reveal calcification on medial epicondyle in severe cases. Treatment includes rest, ice, compression, and elevation (RICE). Prevention from injury is key in healing, including education on proper technique. A steroid injection to the region will be helpful, but forearm straps do not provide as much relief as with tennis elbow.
Shoulder dislocations usually occur from falling onto an outstretched arm or trauma to the shoulder in a specific location.
Lateral Epicondylitis Lateral epicondylitis (tennis elbow) of the elbow is due overuse of the forearm extensor muscles. This is classically from an overexertion while performing a backhand stroke in tennis. Also, this may be from repetitive forearm muscle contractions. Patients may note lateral elbow pain with activity and tenderness to palpation. There may be occasional swelling and weakness of wrist extensors. X-rays may reveal calcification at the lateral epicondyle in severe cases. The best treatment would be prevention, via use of proper backhand techniques in tennis, or avoiding overexertion. After initial injury, application of ice, rest, compression, and elevation calms inflammation. Use of a forearm strap placed over the bulk of the extensor forearm musculature helps the efficiency of the muscle, thereby decreasing strain. A steroid injection can also be used as an effective treatment. Medial Epicondylitis Medial epicondylitis (golfer’s elbow) is caused by twisting the wrist a certain way to obtain a stronger golf swing. Symptoms present as medial elbow
Olecranon Bursitis Olecranon bursitis is caused by a direct blow or constant pressure over the elbow (olecranon) region. It is one of the most frequently inflamed bursa, which may also involve a bacterial infection. A patient may have pain and swelling of the olecranon region as well as tenderness and swelling of the surrounding bursal sac. Infection should be suspected if the area is warm and red. An aspiration of the elbow or bursal sac may show crystals, inflammation, and infection. X-rays rule out fractures and calcification in chronic conditions. Aspiration of the joint helps diagnose as well as treat the region. Infection must be treated immediately with antibiotics. Application of compression, ice packs initially help, and heat packs may be applied after 72 hours to hasten fluid absorption. Steroid injections to the region are questionable as this may worsen an infection. Mallet Finger Mallet finger is a common sports injury, occasionally leading to fracture caused by partial tearing of the bone by a tendon due to a bent finger during sports. Symptoms include pain at the distal end of the finger, inability to extend the finger, and tenderness over the area. X-rays may reveal the fracture in a severe case, or they may be normal. Treatment includes a finger brace, compression, rest, ice, and possible elevation. Analgesics or antiinflammatories may also help. If there is no fracture, a finger splint in a straight position for six to eight weeks may be helpful. If untreated, the hand may result in permanent inability to extend. Jersey Finger Jersey finger (football finger) is due to forced extension of the distal phalanx while actively flexing the
1602 Sports Injuries finger. This is classically from athletes grabbing onto a jersey. This action may result in Grade II tear or a bony avulsion fracture of the flexor digitorum profundus tendon. Symptoms include pain and swelling at DIP and inability to flex the DIP with localized tenderness at the level of the avulsed segment. X-rays will show the avulsed fragment and may help to localize level of retraction. The use of analgesics and RICE initially will keep down initial inflammation. Surgical intervention within three weeks is necessary with retraction of the tendon to the PIP or within one week with retraction to palm. A healing time of six to 12 weeks may be necessary. Boxer’s Knuckle Boxer’s knuckle (dislocation of extensor hood) is caused by trauma to the fist with the fingers making a fist, which causes a disruption of the extensor tendon. This deformity is seen on physical examination, and there is usually no treatment for this other than protection and RICE. Skier’s/Gamekeeper’s Thumb Skier’s/gamekeeper’s thumb is caused by backward bending of the thumb, causing ligamentous microtears. There is usually pain over the ulnar collateral ligament, weak and painful pinching action, and tenderness over the thumb. An X-ray should be performed prior to any stress testing. Most of the time, orthopedic referral is required to prevent complications, but until then, protection of the joint, rest, ice packs, compression, elevation, analgesics, and placement of a thumb spica with the thumb in full extension can be done. Scaphoid Fracture Scaphoid fracture occurs when one falls onto an outstretched hand causing hyperextension of the wrist; trauma to this bone disrupts its fragile circulation. Initial X-rays may miss the fracture and necrosis even though this is the most common carpal fracture. Symptoms include pain and tenderness on palpation over anatomic snuff box (area of the hand that makes a depression when the thumb is hyperextended), pain with wrist motion, swelling, and bruising of the wrist. Repeating the X-ray in two weeks may reveal signs of necrosis.
Treatment includes a wrist splint, hand rest, ice, and pain medications. For severe cases, surgical pinning is necessary, followed by casting. Greater Trochanter Bursitis Greater trochanter bursitis is caused by direct trauma of the hip or overuse may lead to inflammation of the lateral hip bursa. This is common in runners and bicyclists and is usually due to tightness of iliotibial band. Symptoms include deep aching over the lateral hip down to the lateral knee, which is worsened with activity. Palpation over the greater trochanter will elicit tenderness, but X-rays are generally normal. Treatment includes ultrasound followed by stretching as well as rest, application of ice, medications, and education. If symptoms persist, a local steroid injection with an anesthetic does well to treat this condition. Return to activities as symptoms allow. Piriformis Syndrome Piriformis syndrome is due to muscle spasm of the piriformis muscle irritating the sciatic nerve as it passes through the muscle. Activities requiring refined or aggressive hip motion often strain the piriformis, which in turn irritates the sciatic nerve. It is common in cyclists and females. It may present as an aching pain in the buttocks with radiation down the leg, and pain with raising or twisting the hip. Prolonged sitting and bicycle riding worsens symptoms. X-rays are normal. Treatment includes protection of the hip, rest, application of ice, progressive hip stretching, and analgesic and antiinflammatory medications. Deep tissue massage may help, as may a padded seat for cyclists. Osteopathic manipulative therapy (OMT) may be beneficial as well. This is a manual medicine modality performed by osteopathic physicians (DOs), who are full physicians with an added tool of manual medicine. Anterior Cruciate Ligament Anterior cruciate ligament (ACL) injury may be caused by a blow to lateral side of the knee, which causes stress to the medial part of the knee. Patients have knee pain, a possible audible pop with trauma, a bloody knee effusion, and positive findings on special tests. If an ACL injury is suspected, a medial meniscal and medial collateral ligament injury is also commonly associated (the “terrible triad”) and should be
investigated as well. MRI is diagnostic, showing inflammation or tear of the ACL. Healing time can be four to six weeks, but up to eight weeks in the presence of an effusion. Treatment includes a knee immobilizer and crutches as well as RICE and medications for pain and swelling. Physical therapy will expedite healing. If the injury is not severe and nonsurgical, return to function can occur within 6 to 12 weeks. However, surgery may be necessary if instability persists 2 to 4 weeks after injury, and it may take 6 to 12 months of healing time after surgery. Medial Tibial Stress Syndrome Medial tibial stress syndrome (MTSS, shin splints) is generally caused by overuse, especially running. A sudden increase in intensity of training can also cause stress along the medial fascial insertion of the soleus muscle causing myositis, fasciitis, periostitis, and posterior tibialis inflammation. Patients feel pain in the shins that is worse with activity and better with rest. Standing on the toes may increase the pain. With palpation, there is tenderness along the posterior shin. Treatment includes rest in the first week, then gently progressive calf stretching, NSAIDs, ice, crutches, and analgesics. Achilles Tendinitis Achilles tendinitis is due to overuse, often from jogging uphill. Symptoms are typically activity-related pain, localized to the Achilles tendon, above the heel. Recent changes in shoes or training may exacerbate the condition, but there may be tenderness, swelling, or crepitus over the Achilles tendon, and repeat injury may cause it to become thickened and nodular. Rest, modifying activities, avoiding hill running, and gently progressive calf stretching are effective treatments. Achilles Tendon Rupture Achilles tendon rupture may be caused by sudden foot movement changes while running, such as an abrupt change in direction while playing basketball. A patient may feel or hear a sudden pop in the heel with difficulty in walking. There may be a feeling of being kicked in the heel. Initially, a nonweight-bearing status should be created by the use of crutches. Placing ice onto the tendon
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decreases swelling and pain, and mild elevation of the extremity should be maintained. Nonoperative repair involves casting the ankle, but in severe cases, surgical repair with postoperative casting may be necessary. Fifth Metatarsal Fracture Fifth metatarsal (bone of little toe) fracture is common in gymnasts and dancers, because of the repeated direct trauma to the mildly inverted (bent inward) foot. Initially, the patient may have localized tenderness, swelling, and bruising on the side of the foot. X-rays usually detect the fracture. Treatment includes a short walking cast for four to six weeks, but an orthopedic consultation may be necessary if the fracture is displaced. Using RICE and analgesic medications will aid in the healing process. Plantar Fasciitis Plantar fasciitis is inflammation of the connective tissue of the sole of the foot, which may cause heel pain as well as inflammation and tenderness. The pain is present with the first step in the morning or after a long rest or after prolonged activity. There may also be point tenderness at the heel upon palpation. Treatment begins with stretching and NSAIDs as well as ice to the area. If these conservative measures do not help, a steroid injection may relieve discomfort for several months. The patient may have gained weight prior to the onset of symptoms; hence, weight loss may help as well. SEE ALSO: American Academy of Orthopedic Surgeons
(AAOS); Exercise/Physical Fitness; Orthopedic Surgeon.
BIBLIOGRAPHY. B. Anderson, “Concussion and Mild Traumatic Brain Injury,” www.uptodate.com (cited October 2006); L. Callahan and R. Sheon, Overview of Running Injuries of the Lower Extremity,” www.uptodate.com (cited October 2006); S. Karageanes, Principles of Manual Sports Medicine (Lippincott Williams & Wilkins, 2005); Maughan, “Ankle Sprain,” www.uptodate.com (cited October 2006); J. Puffer, 20 Common Problems in Sports Medicine (McGraw-Hill, 2002); R. Sheon, “Plantar Fasciitis and Other Causes of Heel and Sole Pain,” www.uptodate.com (cited October 2006).
George P. Kolo, D.O. Kansas City University
1604 Sprains and Strains
Sprains and Strains Sprains and strains are two similar but distinct musculoskeletal injuries that occur from trauma to the body. They are distinguished based on their unique symptoms, injured structures, and mechanism of injury. The treatment varies greatly, depending on the severity of the injury, as well as the patient’s preinjury health status. The prognosis varies as well, based on individual patient characteristics and type of injury. Sprains Ligaments are strong bands of tissue connecting bones with each other. These ligaments are encountered all over the body, in areas such as the shoulder, knee, spine, hand, and ankle. They provide stability and protection for the joint. When one or more of these ligaments is suddenly overstretched or torn, a sprain occurs. Along with the injury to the ligament itself, sprains often involve pain, swelling, and discoloration of the adjacent soft tissue due to bleeding and inflammation of structures around the area. Sprains are divided into three grades depending on the severity of the physical injury: • Grade 1: Small stretching of the ligament with minimal swelling and tenderness. The patient is able to move the joint and bear weight on it with minimal pain. • Grade 2: Partial tear of the ligament with moderate swelling, tenderness, and discoloration. The patient has some difficulty moving the joint with definite pain on weight bearing. • Grade 3: Complete tear of the ligament with severe swelling, tenderness, and discoloration. The joint has lost its stability and the patient is unable to move it or bear weight on the joint. The physical examination is helpful in diagnosing a sprain, but often, radiographic imaging such as Xray or magnetic resonance imaging (MRI) is needed to determine the extent of injury. Some examples of easily sprained joints include the ankle, wrist, and knee. A sprain of the outside, or lateral, part of the ankle is the most common sports injury. This occurs when the ankle rolls outward with the foot falling inward. It is referred to as an inversion sprain and damages the ligaments and tissues on the lateral part of the ankle.
A scapholunate dissociation is common sprain occurring in the wrist. This involves damage to the ligament that connects the scaphoid and lunate bones in the wrist and usually occurs when people try to catch themselves while falling, landing on their outstretched palm. On an X-ray, if there is more than 3 mm of distance between the scaphoid and lunate, a ligamentous injury is likely. X-rays can also help determine if there is a fracture. A third common sprain occurs at the medial collateral ligament (MCL) of the knee. This occurs when a force contacts the lateral knee, causing it to bend sideways, resulting in a widening of the joint on the inside portion. This excess stretch of the MCL often causes a tear and may lead to pain, swelling, and decreased stability of the knee. Treatment of an acute sprain is easily remembered utilizing the acronym PRICEM: • Protection, stabilizing the injured area with a brace or splint to help prevent further injury. • Rest, taking stress off the injured body part. This can involve using crutches or a sling. • Ice, should be placed on the site of injury to help reduce swelling and pain. • Compression, used soon after the injury to help prevent further swelling from developing. • Elevation, the injured body part should be placed above the level of the heart to decrease the amount of fluid settling in the injured area. • Medications and manipulation. Anti-inflammatory and pain medications as well as manual treatment can help decrease swelling and pain, and aid the healing process. After the acute phase of a sprain injury, physical therapy and rehabilitation may be useful to rebuild the strength and stability of the injured joint. Strains Strains are similar to sprains but differ as they involve muscles and tendons (attach muscles to bones) versus ligaments. Strains are usually overuse injuries occurring when muscles or tendons are partially or completely torn. The most common site for a strain to occur is at the point where it joins the tough, fibrous tendon. Symptoms common to strains include pain at the injury site, reduced flexibility and motion of the injured muscle, and visible bruising when blood vessels are torn. Muscle weakness and spasm, as well
Sri Lanka
as swelling are other frequent findings with a muscle strain. Conditions that might predispose a person to suffer a muscle strain include tight or weak muscles, lack of conditioning, and improper warm-up before beginning a physical activity. Common areas of the body that can suffer strains include the lower back, and the hamstring muscles of the back of the thigh and fingers. Strains of the lower back occur when the spinal muscles undergo a twisting or pulling motion and are overstretched or torn. This happens from activities such as improper lifting, direct blows to the lower back, or injuries sustained in athletic competition. Hamstring strains occur commonly from running, jumping, or the action of kicking something such as a soccer ball. An inequality in strength between the hamstring muscles on the back of the thigh and the quadriceps muscles on the front of the thigh is the culprit in causing susceptibility to a hamstring strain. Gamekeepers’ or skiers’ thumb is a strain of the ulnar collateral ligament (UCL) in the webbed area between the index finger and the thumb. This injury can occur when falling onto an outstretched thumb. The thumb is pulled away from the rest of the hand, damaging the UCL. Swelling and pain at the joint between the thumb and the rest of the hand are common with gamekeepers’ thumb. Cervical strain is another common strain injury involving the muscles and tendons of the neck. When this strain happens acutely due to a motor vehicle accident, it is called whiplash. Cervical strain can also occur over a longer period of time in a more chronic manner. People who work at desk jobs or in physical labor can develop damage to their neck muscles through repetitive stress related to work conditions. Treatment of an acute strain is similar to that of a sprain, and the PRICEM method is useful in the first few hours of injury. Physical therapy and rehabilitation are also helpful in speeding up the healing process after an acute injury. It is not possible to completely prevent sprains and strains, but good flexibility and strength can help protect the body from injury. Proper stretching reduces the chance of straining a tight muscle, and good strength of muscles and ligaments help stabilize joints and keep them from succumbing to traumatic injury. SEE ALSO: American Academy of Orthopedic Surgeons
(AAOS); Exercise/Physical Fitness; Sports Injuries.
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BIBLIOGRAPHY. Bruce C. Anderson, “Evaluation of the Patient with Wrist Pain,” www.uptodate.com (cited October 2006); allahan, Lisa R. and Robert P. Sheon, “Overview of Running Injuries of the Lower Extremity,” www.uptodate. com (cited October 2006); Steven J. Karageanes, Principles of Manual Sports Medicine (Lippincott Williams & Wilkins, 2005); Karen L. Maughan, “Ankle Sprain,” www.uptodate. com (cited October 2006); “Muscle Strains in the Thigh,” http://orthoinfo.aaos.org/fact/thr_report.cfm?Thread_ ID=296&topcategory=Hip (cited October 2006); James C. Puffer, 20 Common Problems in Sports Medicine (McGrawHill, 2002); “Sprains and Strains: What’s the Difference?” http://orthoinfo.aaos.org/fact/thr_report.cfm?thread_id =45&topcategory=General percent20Information (cited October 2006); “Worsening Thigh Pain after Blunt Trauma,” Medicine On-Line: Images in Radiology (April 2006).
George P. Kolo, D.O. Sarah K. Sundet, MS IV Kansas City University
Sri Lanka The island country of Sri Lanka is located off the south coast of India. Known as Ceylon, it was occupied by the Dutch from the seventeenth century, and then by the British who held it until independence on February 4, 1948, In 1972 the country changed its name to Sri Lanka. It has a population of 20,743,000 (2005), and a effective healthcare system in much of the country, with 37 doctors and 103 nurses per 100,000 people. The remains of the oldest known hospital in the world is located at Mihintale, near the city of Anuradhapura, in Sri Lanka. It was developed by King Pandukabhaya in the 4th century b.c.e., and archaeologists believe that it was the first purpose-built medical facility where people suffering from different ailments were treated in separate areas with other people with similar illnesses. The Dutch established some small hospitals for Europeans, and the British built the General Civil Hospital, the Lady Havelock Hospital and the Eye Hospital in Colombo, the capital, and other treatment centers in other cities. There were also dentists and doctors who operated at the Bristol and the Grand Oriental Hotels. At the same time, many Sri Lankans continued to use ayurveda (“traditional medicine”) using the theory
1606 Staphylococcal Infections of the “three humors” which has the human body made up or air, fire (bile) and water (phlegm). This assumed that problems were related to an imbalance between these humors. In 1870 the Colombo Medical School was established, making it the second oldest medical school in South Asia. It was later amalgamated with University College in Colombo to form the Faculty of Medicine at the University of Ceylon, now the University of Colombo. The Medical Research Institute in Colombo was established in 1900, and one of the major problems on the island was malaria, which still presents a problem in isolated parts of Sri Lanka. There were also medical problems with tuberculosis, typhoid and cholera. There has also been a long problem of oral cancer through the high incidence of chewing betel nut by men in the country. After independence, the healthcare in the country considerably improved. The crude death rate which had been 19 per 1,000 in 1871 fell to 13 per 1,000 at independence, and was 6 per 1,000 by the early 1980s. There was also free state medical care provided for all people in the country, and the government operated health clinics in villages offering both European medical treatment and also traditional medicine. The main hospital in Colombo was renamed the National Hospital of Sri Lanka, and the nearby hospitals, the De Zoysa Maternity Hospital and the Lady Ridgeway Hospital for Children were both enlarged and connected to the University of Colombo. There are also Faculties of Medicine at the University of Jaffna, the University of Peradeniya, and the University of Ruhuna, at Matara. The war in Sri Lanka during the 1980s and 1990s resulted in large numbers of deaths, in a breakdown in the infrastructure in parts of the country, especially the Tamil-dominated north. The result was a blockade on trading with the north, which developed a severe shortage of medical supplies. The gradual lessening of the fighting has allowed medical care to be provided to many more people, and the money which had been devoted to the fighting to be used to improve sanitation and hygiene. SEE ALSO: Cholera; Oral Cancer; Typhoid. BIBLIOGRAPHY. Soma Hewa, Colonialism, Tropical Dis-
ease and Imperial Medicine: Rockefeller Philanthropy in Sri Lanka (University Press of America, 1995); K.L.S.
Kusumaratne, Indigenous Medicine in Sri Lanka: A Sociological Analysis (Sarasavi Publishers, 2005); C.G. Uragoda, A History of Medicine in Sri Lanka—From the Earliest Time to 1948 (Sri Lanka Medical Association, 1987). Justin Corfield Geelong Grammar School, Australia
Staphylococcal Infections Staphylococci are ubiquitous, catalase-positive, gram positive cocci that form grape-like clusters. They are normal colonizers of the skin and mucous membranes. There are over 30 species of Staphylococci, however, only several members of the genus cause disease in humans. Staphylococcus species are divided into coagulase positive and coagulase negative groups. S. aureus, the most important human pathogen within the genus, is the only coagulase positive species. S. auerus has many virulence factors that contribute to its abiltity to produce very severe disease. Coagulase negative species that may cause human infection include S. epidermidis, S. haemolyticus, S. saprophyticus, S. schleiferi, and S. lugdunensis. Coagulase negative staphylococci are generally less pathogenic unless a foreign body such as a central line is in place. Between 20 and 50 percent of children are colonized by S. aureus with the skin and mucous membranes as the most common location. While the vast majority of those colonized never develop clinical disease, S aureus can cause a variety of pyogenic and toxin mediated syndromes. The bacterium is generally transmitted by direct contact and is only very rarely spread through airborne droplets. Diseases caused by S. aureus include infections of the skin, bone, lungs, joints, central nervous system and heart. Toxin mediated diseases caused by this organism include food poisoning, scarlet fever, toxic shock syndrome, and scalded skin syndrome. Medical risk factors for S. aureus infection include diabetes, chronic liver disease, nutritional deficiencies, burns, and congenital and acquired immune deficiencies. S.aureus is a frequent cause of hospital acquired infection and risk factors for nosocomial infection include admission to an intensive care ward or burn unit, prolonged hospital stay, long term intravenous
or central lines, and foreign bodies such as artificial joints and heart valves. In the absence of established risk factors, positive coagulase negative staphylococcal blood cultures generally represent a contaminant rather than true infection. However, in a high risk patient, such as an infant in a neonatal intensive care unit with clinical signs of infection, a culture positive for coagulase negative staphylococci should be considered a true infection and treatment initiated. There are no currently licensed vaccines providing protection against Staphylococcal infections and judicious hand washing and sterile procedures in healthcare settings and antibiotics remain the mainstays of prevention and therapy. While minor staphylococcal infections may be treated with oral antibiotics, more severe infections necessitate use of intravenous medications. Most strains of S aureus produce β-lactamase enzymes and are thus resistant to β-lactam class antibiotics such as penicillin and ampicillin. First line therapy is therefore oxacillin or a first or second generation cephalosporin antibiotic until sensitivities are known. A rapidly worsening problem is the spread of methicillin resistant S. aureus (MRSA). In many hospitals in the United States, half or more of all S. aureus isolates are resistant to methicillin. Traditional risk factors for hospital-acquired MRSA infection have included long admissions, recent antibiotic use, and multiple surgical procedures. However, recently an increasing number of community-acquired MRSA in previously healthy adults and children without traditional risk factors is being seen. MRSA infection is treated with intravenous vancomycin. Alarmingly, a small number of vancomycin resistant staphylococcal isolates have now been identified in the United States, raising fears of a pathogenic bacterium resistant to all antibiotics. Shrewd use of antibiotics, compliance with infection control practices, and ongoing surveillance is required to stem the spread of this and other human disease causing antibiotic resistant bacteria. SEE ALSO: Bacterial Infections; Bacteriology. BIBLIOGRAPHY. C. S. F. Easmon, Staphylococci and Staph-
ylococcal Infections: Clinical and Epidemiological Aspects (Academic Press, 1984); PM Medical Health News, 21st Century Complete Medical Guide to Staphylococcal Infec-
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tions (Staph): Authoritative Government Documents, Clinical References, and Practical Information for Patients and Physicians (Progressive Management, 2004); John N. Sheagren, Staphylococcal Infections (Current Concepts) (The Upjohn Company, 1992); Staphylococci and Staphylococcal Infections (Academic Press, 1984). Shaun K. Morris, MD, MPH Independent Scholar
Stem Cells/Stem Cell Transplantation The human body is composed of a vast number of cells, on the order of 1013 to 1014. These are grouped, based on functional and morphological characteristics into various types of tissue composed of similar cells. Yet, for all humans, there was a time when there was but one cell. This cell was the product of syngamy (fertilization): the union of egg and sperm. This one cell divided and, in response to internal and environmental cues, various cells arising from these divisions became what we call stem cells. Stem cells are distinguished by their ability to proliferate indefinitely and their ability to give rise to numerous more specialized cell types. In contrast, differentiated cells have a limited ability to renew themselves and are limited in the types of cells they may differentiate into. The above description characterizes a progression from one cell to many which is accompanied by increasing specialization and diminishing potential. The potential available to a cell’s successors is known as its plasticity. The most specialized cells in the human body perform a particular task very well and divide very few times, if at all, before dying. These cells are said to have no plasticity: they are committed to a certain fate. Contrast this with the original cell of the zygote (the product of syngamy). This one cell can give rise to all the cells of the human body as well as all the cells needed for development of the maternal environment (placenta, etc.). It is said to be totipotent in its plasticity: Its successors may be any cell type. At some point early in embryonic development, cells have differentiated into those committed to maintaining the developmental environment and those destined to be a part of the developing human
1608 Stem Cells/Stem Cell Transplantation being. These cells are said to have pluripotent plasticity as they can give rise to many, but not all, of the cell types needed to bring a human being into the world. These pluripotent cells are known as stem cells. More specifically, they are embryonic stem cells. Embryonic stem cells are sometimes referred to as totipotent because although they cannot differentiate into all tissue types, they can differentiate into any tissue type seen in humans after the time of birth. Interest in stem cells is driven by their potential use in stem cell transplantation as part of regenerative medicine. This branch of science seeks to remedy those diseases and dysfunctions caused by the absence of, or defects in, certain specialized cells or groups of such cells organized as tissue or organs. Examples of such diseases are diabetes (pancreatic dysfunction) and Parkinson’s diseases (neurological degeneration). The goal is to take stem cells and induce them, through chemical and physical means, to specialize (differentiate) into the sorts of cells, tissues, or organs needed to remedy the disease or dysfunction. The ideal stem cell will be easily acquired and amenable to efforts at directed differentiation. The Origin of Stem Cells While stem cells may be classified according to their level of plasticity, a more functional method of classification is by source. Generally speaking, when classified by source, all stem cells within a classification will have comparable plasticities. Two classes of stem cells are already apparent. Those destined to form the cells of the maternal environment are termed human placental stem cells (hPSCs). Most of the remaining cells are human embryonic stem cells (hESCs). As development progresses, cell specialization occurs and stem cells of diminished plasticity (typically termed multipotent) become the norm. At various stages of development these are termed human fetal stem cells (hFSCs) and human adult stem cells (hASCs). At later stages of differentiation (diminished plasticity), it is common to refer to the stem cells by the limited types of specialized cells they can give rise to. Hence, hematopoietic stem cells from bone marrow and umbilical cord blood give rise to the various blood cells and neural stem cells give rise to various cells of the nervous system. hASCs are acquired from willing adult donors, particularly marrow donors. Also, cord blood can be collected at the time of birth and stored for future use or
research. Human fetal stem cells are collected from abortuses. A more complicated picture arises when hESCs are considered. Such cells are clearly taken from embryos (specifically the inner cell mass), but unlike with hASCs, it is not currently possible to obtain hESCs in significant quantities and maintain the viability of the embryo. Also, unlike adults who exist independent of any research need, embryos can arise in a number of ways. A large number of embryos remain frozen as so-called supernumeracy embryos created as part of in vitro fertilization (IVF). In some jurisdictions, it is legal to use IVF to create an embryo with the explicit intent of acquiring stem cells from its inner cell mass; in many jurisdictions, such acts are illicit. Finally, it is now, at least theoretically, possible to use a cloning technique known as somatic cell nuclear transfer (SCNT) to create an embryo and acquire hESCs from it. Fertilization and Somatic Cell Nuclear Transfer Because many considerations of the ethical, legal, and social impact of stem cells arise from the use of cloning to obtain hESCs, a basic understanding of cloning and its differences from fertilization is crucial to evaluating the competing arguments. Normal human development begins with fertilization: the fusion of egg and sperm to form a zygote. After four to five days of growth and differentiation, the zygote reaches the blastocyst stage (100–200 cells). If this development has taken place in utero, the blastocyst may implant on the uterine wall and, with the right conditions, develop into a newborn in due course. If fertilization is done via IVF, there is no reason the blastocyst must ever be implanted. Blastocysts have been maintained in media for up to 14 days. During this period, it is possible to extract embryonic stem cells from the blastocyst. Blastocysts have also been maintained indefinitely in cold storage where they might be later used as a source of embryonic stem cells or as part of an IVF procedure leading to pregnancy and, later, birth. Cloning of mammalian species via SCNT is a complex, multistep process. First, an egg cell is obtained from a female (not unlike IVF). This cell is then enucleated (the nucleus is removed). Concurrently, a nucleus is removed from a somatic cell of the organism being cloned. This nucleus is placed into the newly enucleated egg cell. This cell is then stimulated to launch a
cascade of biochemical events leading to cell division resembling that of a zygote arising from fertilization. The most significant difference between fertilization and SCNT is obvious: The former leads to a zygote with two genetic progenitors, whereas the latter has only one. This naturally gives rise to a functional difference in the use of hESCs from each of these sources in regenerative medicine. hESCs from IVF-created embryos (or, indeed, stem cells of any type from a product of sexual reproduction) will have, at most half of all nuclear DNA in common with a potential recipient of regenerative medicine. Tissue typing of the sort currently used in transplants will be needed to limit rejection, necessarily limiting the potential of such therapies. On the other hand, if the donor nucleus for the SCNT procedure comes from the future stem cell recipient, the stem cells created will be an exact match, ensuring the usefulness of the stem cells. Controversial Aspects of hESCs Given that hESCs are pluripotent, many researchers see them as the ultimate tool of regenerative medicine. Other types of stem cells, by virtue of their more limited plasticities, have limited potential to treat dysfunction. This is particularly true in cases where the partially differentiated hASCs are difficult or impossible to obtain. On the other hand, precisely because hESCs hold such potential, they are exceedingly difficult to control and direct. A leading technical argument in favor of non-hESC lines of research is a simple cost–benefit argument that hASC-based therapies are simply much closer to market (the only mainstream stem cell transplantation in use in humans—bone marrow transplant—is a hASC-based procedure). There are also major ethical concerns about the ways in which hESCs are acquired. All currently practiced methods of obtaining hESCs require the destruction of an embryo. For those who argue that the blastocyst is a full member of the moral community, destroying a blastocyst to acquire hESCs is tantamount to murder and treating individuals as means not ends. While some hold that embryos at the blastocyst stage have no status beyond that of a clump of cells, many observers have assigned the blastocyst an intermediate status characterized by “respect” but without the near absolute protection from destruction generally granted full members of the moral community. These
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conflicting views of what is destroyed when hESCs are acquired from a blastocyst give rise to many of the arguments on which activities in this sphere are ethically permissible. Legal Perspectives on hESC Research Given the number of ways in which hESCs can be procured and the number of policy mechanisms at the disposal of legislative bodies, it is not surprising that there is little, if any, consensus among nations on how to regulate research on hESCs. It is, however, possible to break various legislative schemes down along a number of regulatory axes: I) The use of supernumeracy embryos for derivation of hESC lines II) The creation of embryos via IVF for derivation of hESC lines III) The creation of embryos via SCNT for derivation of hESC lines Within Europe, axes II and III were together addressed within the Convention of the Council of Europe on Human Rights and Biomedicine at Oviedo, Spain, in 1997. This treaty obliges signatories to incorporate statutory bans on the creation of human embryos for research purposes and the procurement of hESC lines into national law. Research on supernumeracy embryos is not addressed in this convention and is a major point of difference in EU member nation hESC regulatory regimes. Starting at the extremes, Belgium and the United Kingdom explicitly allow activity on all three axes and seven nations prohibit the procurement of hESC lines from any embryos, including supernumeracy embryos (axes I, II, and III; Germany, Austria, Italy, Ireland, Lithuania, Poland, and the Slovak Republic). The remaining countries either explicitly allow the derivation of hESC lines form supernumeracy embryos or have laws that allow experimentation on embryos and do not prohibit the derivation of hESC lines from such embryos (axis I), but otherwise restrict activity along axes II and III. The quest for regenerative medicine is not a purely European one. It is not even restricted to just the richest nations. Unlike Europe, though, a number of nations in the rest of the world are not Christian (officially or by simple numerical presence). Whereas Christendom has been part of the fabric of Europe for well over a millennia, the non-European nations
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can largely be divided between those that have had a strong Christian influence since they became nation-states (primarily the Latin American nations) and those with either non-Christian or late-coming Christian traditions. South Africa, Singapore, Japan, China, Thailand, and Taiwan all have dominant non-Christian faiths or significant minorities of competing belief systems. These are also countries with broadly permissive regulatory regimes, generally allowing activity along all three axes. Contrast this with Ecuador, Argentina, Brazil, Mexico, and Peru which have had strong Catholic traditions since their colonial periods. All of these nations have strong restrictions on obtaining hESC lines from any source. The regulation of hESCs in the United States is presently muddled by the absence of federal regulation. Regulation at the federal level exists only in the form of funding restrictions. True regulation comes from the states. State-level intervention exists in 15 states in combinations of criminal and administrative law as well as funding mandates and restrictions and statutory guarantees that certain avenues of research relating to hESCs will not result in prosecution. Ethical Considerations There has been no significant objection to the use of stem cells in regenerative medicine or research on stem cells, including hESCs. Instead, objections to date tend to address the source of stem cells. That is, neither stem cells in and of themselves nor the ends to which researchers and clinicians wish to put them are objectionable. The objection is to creating and/or destroying embryos in order to obtain hESCs. Secular arguments about the ethics of hESC research and transplantation mirror the concerns addressed by the three axes of regulation. However, there is scant secular ethical support for the distinction proposed by axes II and III. Whether an embryo arises from SCNT or IVF is largely irrelevant to the question of whether it is ethical to obtain stem cells from the embryo and destroy it. Thus, the arguments may be divided first by the level of respect granted to the product of SCNT/IVF and second by whether there is a distinction between the use of so-called supernumeracy embryos “left over” when IVF therapy is successful but unimplanted embryos still exist, and the creation, through IVF/SCNT, of blastocysts explicitly for research purposes.
In general, one may ascribe to the blastocyst status approximately equal to that of a person, status equal to any other aggregation of cells (e.g., a cheek swab) or as intermediate-status supporters have termed special respect. The first generally precludes obtaining hESCs as an ethical activity; the second permits it. The intermediate position does not preclude research on the blastocyst, even research that destroys the blastocyst, but it does preclude egregious research which is not readily justifiable on grounds that it may improve the lot of the very ill. This intermediate position allows for a diversity of opinion as to whether there is a difference between research on supernumeracy embryos and embryos created explicitly for research with some arguing that creating embryos explicitly with the intention of their destruction is the antithesis of respect and others arguing that whatever harm or injury such research might inflict on the blastocyst, the social benefits are simply too great to be ignored. Religious commentary on hESCs largely falls into the same set of positions as secular argumentation with the exception that many religious traditions emphasize the union of man and woman (sperm and egg) as a crucial moral distinction between IVF and SCNT or between natural reproduction and IVF/SCNT. This emphasis makes the distinction between axes II and III meaningful in the context of religion. That is not to say that there is uniformity of opinion between religions or even within religions, particularly between the various sects of Christianity, which have widely divergent views on the nature embryos. Within Christianity, the Roman Catholic Church and many Protestant denominations are prominent opponents of all hESC research on the grounds that it leads to the intentional killing of persons who come into being at the moment of conception. Other Protestant denominations take markedly different views. In particular, Anglicanism, which has long held that personhood is acquired sometime between conception and birth, does not object to the destruction of blastocysts per se. Indeed, the Church of England has embraced hESC research when conducted using embryos that fertility clinics would otherwise have stored indefinitely or destroyed. The Anglican Communion, however, does object to the creation of life for the purpose of its destruction, a clear condemnation of SCNT as well as the use of IVF for hESC research instead of reproduction.
Islamic and Jewish ethics, adhering to variations on ensoulment theory both draw distinctions between blastocysts and later developmental stages. However, these faiths also have strong opinions on the use of IVF and have approved them (with some contention between specific sects) only for reproductive purposes. As such, most authorities from these faiths object to the use of SCNT or IVF as part of hESC research and therapy; a minority support research on axes I and II. Buddhism speaks without a clear voice on this point. Instead, two principles at odds with each other are presented and believers are left to contemplate them. Given the emphasis Buddhists place on knowledge and compassion, advances that might come from cloning research are to be praised. However, Buddhists also place emphasis on ahimsa (nonharming). The destruction of blastocysts is potentially prohibited by the First Precept of Buddhism, which prohibits causing death or injury to living creatures. Scientific Approaches to Ethical Objections There are many efforts under way by researchers to develop methods of obtaining hESCs that satisfy current ethical critiques. They generally fall into three groups: avoiding embryo destruction, creating nonembryonic sources of hESCs, and increasing the functionality of hASCs. There are two main lines of argumentation and action which seek to avoid the destruction of embryos in hESC research and therapy. The argumentative approach is purely theoretical. It has been suggested that instead of tying the ethical discourse of hESCs to embryonic status and, by extension, the abortion debate, a better model is that of organ and tissue donation. Many groups, with varying views of hESC research accept heart and lung donation as ethical activities. If this practice is accepted as ethical, then perhaps embryos stored in IVF clinics could be viewed similarly and have their “life support” removed and then see their hESCs harvested for research and/or transplantation. The active approach seeks to use technologies related to preimplantation genetic diagnosis to harvest one or two cells which can serve as a source of stem cells without destroying the rest of the embryo. A key objection to this plan is that it fails to address the actual fate of the embryos as, at the end of the
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day, the embryo in question is still here at the IVF clinic. Also, because studies consistently show little interest by couples in donating their supernumeracy embryos for research purposes, such a plan would still require IVF or SCNT to create the initial embryo, something that will not satisfy opponents of research on axes II and III. The creation of nonembryonic sources of stem cells is, in many ways, even more speculative than attempts to avoid the destruction of embryos. Two methods have been proposed: parthenogenesis and embryo splitting. Parthenogenesis is the development of a diploid organism from a haploid precursor, the egg cell. While there are scientists who genuinely believe that parthenotes (the diploid organisms arising by parthenogenesis) are not embryos, opponents of research on axes II and III counter that parthenotes are diploid organisms whose stem cells are nearly indistinguishable from that or an embryo derived by IVF or SCNT. Even if acceptable, because parthenogenesis begins with an egg cell, it would not be of help to men or to women without any viable egg cells. Although parthenogenesis in primates is well established as a laboratory technique, human experiments have proven much more difficult to execute. Similarly, embryo splitting, which works in primates, is much more difficult to execute in humans. Essentially the process is forced twinning. While this process makes it possible to use an embryo as a source of stem cells without having to destroy it, our current understanding of identical twins argues against the viability of this approach: When twinning occurs, the same people who argue against hESC on all three axes argue that both twins have the same status. Thus, if it is wrong to obtain stem cells from one embryo, creating a twin and performing research on the twin is equally wrong. Finally, methods to increase the plasticity of hASCs have been suggested by opponents of most hESC research as a viable alternative in both research and theory. While critics of hESC research are mollified by plans by various groups to de-differentiate hASCs into more plastic forms, the consensus among researchers who practice hESC research has been to advocate for support for both methods simultaneously. It seems unlikely that this compromise, or any other, will leave parties on both sides of the debate satisfied.
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SEE ALSO: Abortion; Bone Marrow Transplantation;
Clone.
BIBLIOGRAPHY. S. J. Abbondanzo, et al., “Derivation of
Embryonic Stem Cell Lines,” Guide to Techniques in Mouse Development (Academic Press, 1993); C. B. Cohen, “Stem Cell Research in the U.S. after the President’s Speech of August 2001,” Kennedy Institute of Ethics Journal (v.14.1, 2004); D. S. Davis, “Stem Cells, Cloning and Abortion: Making Careful Distinctions,” American Journal of Bioethics (v.2/1, 2002); L. Matthiessen-Guyder, ed., Survey on Opinions from National Ethics Committees or Similar Bodies, Public Debate and National Legislation in Relation to Human Embryonic Stem Cell Research and Use (EU Directorate E: Biotechnology, Agriculture and Food, 2004); National Bioethics Advisory Commission, Ethical Issues in Human Stem Cell Research, Volume I: Report and Recommendations (National Bioethics Advisory Commission, 1999); Parliamentary Office of Science and Technology, “Regulating Stem Cell Therapies,” www.parliament. uk/post/ (cited October 2006). Bimal P. Chaudhari Boston University
Stewart, Alice (1906–2002) Born on October 4, 1906, to two British physicians, Ernest and Lucy Naish, Alice Mary Stewart became well known for her tireless scientific research into the carcinogenic risks of X-rays and nuclear radiation. Although her work caused significant controversy during her lifetime, the results of her research are now an accepted facet of modern medical beliefs. As one of only four female students at Girton College, Cambridge, Stewart endured harassment by 300 male medical students who stomped their feet in protest at her inclusion. After attending Cambridge University, Stewart trained at the Royal Free Hospital. In 1933, she married Ludovick Stewart, a French teacher with whom she had two children; they divorced in the 1950s. Separated by war assignments, Stewart began working at the Nuffield Department of Clinical Medicine in Oxford, where her interest in social medicine flourished. Elected a Fellow of the Royal College of Physicians and receiving a Fellowship at
Lady Margaret Hall, Stewart also became the first female member of the Association of Physicians. In 1956, Stewart first noted connections between cancers, particularly childhood leukemia, and diagnostic X-rays. Although some concern over the effects of obstetric X-rays had already been expressed, Stewart’s conclusions were met with disbelief; some suggested that Stewart’s results, culled from interviews of mothers whose children died from leukemia, were biased. When other studies did not produce the same results as Stewart’s interviews, skepticism increased. Overall, U. S. physicians, whose studies of Japanese children after the atomic bombs did not indicate high numbers of tumors, did not accept Stewart’s findings. Over time, however, other studies—including one conducted by Brian MacMahon in the United States in 1962—confirmed her results. Stewart retired from Oxford in 1974. Afterward, she continued her research at the Department of Social Medicine in Birmingham, also investigating the effects of nuclear energy on workers in the United States. In 1986, she received the Right Livelihood Award, and in 1991, the Ramazzini Award. Stewart died on June 23, 2002, at the age of 95, survived by her daughter, Dr. Anne Marshall (her son died in 1977). SEE ALSO: Leukemia; Radiation Exposure. BIBLIOGRAPHY. John F. Bithell, “Professor Alice Stewart,”
Journal of Radiological Protection, www.iop.org/EJ/abstract/0952-4746/22/4/601 (cited May 2007); Gayle Green, The Woman Who Knew Too Much (University of Michigan Press, 1999); Anthony Tucker, “Alice Stewart,” The Guardian (June 28, 2002).
Kelly Boyer Sagert Independent Scholar
Stickler, Gunnar B. (1925– ) German physician Gunnar B. Stickler, after immigrating to the United States and beginning work at the Mayo Clinic, identified a genetic pattern behind a series of symptoms. This genetic disorder affects the body’s collagen and connective tissue, most often at the bone end
of joints, and in the sclera, cornea, and vitreous humor of the eye. It is now called Stickler syndrome. Stickler attended the Wilhelmsgymnasium, located in Munich, as well as universities in Erlangen and Munich; he graduated with a degree in medicine from Munich in 1949. Immigrating to the United States in 1951, Stickler worked in the Mayo Clinic and at the University of Minnesota, specializing in pediatrics. In 1960, Stickler examined a 12-year-old boy with enlarged joints and shortsightedness; his mother was completely blind and others in the family had similar symptoms. Studying this family’s history, first recorded by Charles Mayo in 1887, Stickler and his colleagues identified a genetic-based disease they called arthroophthalmopathy; it has since been renamed Stickler syndrome. Stickler syndrome affects males and females alike, and it is generally passed from parent to child. In rare instances, a child will have the syndrome even though a parent does not. Children with the syndrome often have somewhat flattened facial features, but this tends to diminish with age. Hearing loss, though, tends to increase. Some children also have mitral valve prolapse, wherein one of their heart valves does not close properly. As yet, there is no cure for the syndrome, although certain symptoms can be treated. In 1973, Stickler was named chairman of pediatrics of the Mayo Medical School. In 1990, Stickler was quoted as blaming the media for the oversensationalizing of diseases to the degree that parents worry too much about rare problems. For example, 50 percent of parents surveyed worried about their children getting cancer while, in fact, only three children under the age of 15 out of every 100,000 actually die from the disease. Seventy-two percent of parents fear kidnapping from a nonfamily member, a crime that occurs to 1.5 children out of every 1 million. Other diseases that receive significantly more attention that reality warrants, according to Stickler’s research, include Lyme disease and Reyes syndrome. SEE ALSO: Genetic Disorders; Pediatrics. BIBLIOGRAPHY. Pediatrics for Parents, “Parental Fears,”
www.highbeam.com/doc/1G1-9365888.html (cited June 2007); Stickler Syndrome Support Group, “About Stickler Syndrome,” www.stickler.org.uk/info.htm (cited June
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2007); Who Named It?, “Gunnar B. Sticker,” www.whonamedit.com/doctor.cfm/1673.html (cited June 2007). Kelly Boyer Sagert Independent Scholar
Stomach Cancer Stomach cancer, also known as gastric cancer, is cancer of the stomach, a muscular organ in the digestive tract. The stomach rests in the center of the upper abdomen, immediately below the ribs. People most susceptible to stomach cancer include those over 55 years of age, men, and African-Americans. Men are twice as likely to develop stomach cancer as comparable women. Another population at an increased risk for stomach cancer is those people who have had stomach surgery. For example, stomach surgery may cause bile to enter the stomach as a side effect (such as removal of the pyloric valve as a treatment for peptic ulcers). This caustic fluid in the stomach could irritate the stomach lining, making it more prone to cancer. Obese people may be at an elevated risk for stomach cancer. Other not well understood risk factors include having Type A blood and suffering from pernicious anemia. The incidence of stomach cancer is lower in the USA than in other nations such as Japan and those of Latin America. One hypothesis for this discrepancy is that people in these other countries eat more preserved foods that have been salted or pickled, which may predispose their stomach cells to cancer. Along with this preserved-food hypothesis is the one that eating fresh fruits and vegetables may be protective for the stomach. Therefore, diets high in salt and low in fruits and vegetables may increase an individual’s risk for developing stomach cancer. Another hypothesis as to the global discrepancy in stomach cancer occurrence is the incidence of infection with Heliobacter pylori (H. pylori), the bacteria that causes most stomach ulcers. According to the World Health Organization, stomach cancer is responsible for nearly one million deaths globally per year. A major reason contributing to its lethality is that often symptoms appear only when the cancer has already spread to other organs. Some symptoms a person may notice if he or she has stomach cancer are
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indigestion or an acidic feeling in the stomach and a loss of appetite for meat. Once the cancer has progressed, the symptoms are still not very specific to stomach cancer; they include nausea, blood in the stools, bloody vomit, fatigue, anemia, weight loss, and pain after meals. Blood in the stools is not always visible to the naked eye; in that case, it can be found microscopically by examining a stool sample. If a lot of blood is lost, anemia and subsequent fatigue may result. The stomach has several types of cells; cancer of any of these cells is classified as stomach cancer. It can spread to nearby organs. Usually the first organs affected are the esophagus, small intestine, and lymph nodes that drain the stomach. Adenocarcinoma of the stomach involves the glandular cells in the stomach lining; it is the most common form of gastric cancer. A carcinoid tumor is not nearly as common as an adenocarcinoma. Carcinoid tumors originate in the stomach’s hormone-producing cells. These cancers are slow-advancing and do not typically metastasize. The stomach also has immune tissue in its muscular wall. This tissue can become cancerous, causing a gastric lymphoma. Mucosa-associated lymphoid tissue (MALT) lymphomas are slow-growing and typically develop after H. pylori infection. When caught and treated early, MALT lymphomas have a good prognosis. Other lymphomas are much more aggressive than MALT lymphomas. There is a fourth type of stomach cancer which is believed to initiate in cells of the Autonomic Nervous System that control digestive function. These cells are the interstitial cells of Cajal. The type of cancer is called a Gastrointestinal Stromal Tumor (GIST). While a GIST can occur anywhere in the digestive tract, it usually develops in the stomach. Because of its unique nature, a GIST requires different treatment than other stomach cancers, and may be a possible target for specific therapies. A minimally invasive procedure to investigate a potential stomach cancer is a gastroscopic exam. The full name of this procedure is an esophagogastroduodenoscopy, which refers to a long slender tube with a lens on one end, which is inserted into the stomach (gastric region) via the esophagus, and may be used to image as far as the first part of the small intestine, the duodenum. Most patients do not need to be sedated for this procedure, and often the only side effect is a sore throat once the procedure has finished. Often,
during the gastroscopic procedure, the physician can take a biopsy. A biopsy is a small sample of suspicious tissue that can then be examined under a microscope by a pathologist. Another procedure to visualize the stomach lining is a Barium X-ray. The patient will swallow a bariumcontaining liquid which then coats the stomach lining. An X-ray is then taken, and the film shows the stomach lining as coated by barium. Any disturbances in the lining due to a tumor should be seen in the X-ray image. Before swallowing the barium, the patient might also swallow a liquid which will form a gas upon mixing with the chemical contents of the stomach. This gas is not harmful; it bloats the stomach, stretching out the various folds of its lining. In this way, the Barium X-ray will be more informative. Once gastric cancer is diagnosed, treatment most often includes surgical removal of part or all of the stomach. Usually, surgical removal involves removal of the surrounding lymph nodes as well. Following surgery, a patient typically undergoes chemotherapy and/or radiation therapy. Because cancer is a disease in which cells cannot control their division, and instead divide and replicate without limit, it can target cells which normally divide and replicate on a daily basis. These normally dividing cells are susceptible to cancer because their DNA is constantly being read by the cell’s replication machinery, leaving it more vulnerable to spontaneous mutation which can cause cancer. Stomach cells are constantly sloughed away by the digestive process and new ones take their place. Cells that are under further stress such as due to an infection by Heliobacter pylori are even more vulnerable. Nitrates and nitrites found in pickled and cured foods can make toxic byproducts in the stomach which can lead to genetic mutation. Tobacco also irritates the cells that line and protect the stomach; tobacco users have a higher risk for stomach cancer than non-tobacco users. Additionally, alcohol use and stomach cancer incidence are related, but the scientific explanation hasn’t yet been deduced. SEE ALSO: Cancer (General); Pancreatic Cancer; Stomach
Disorders.
BIBLIOGRAPHY. ICON Health Publications, Stomach Cancer—A Medical Dictionary, Bibliography, and Anno-
Stomach Disorders
tated Research Guide to Internet References (Icon Health Publications, 2004); Mayo Clinic, “Stomach Cancer,” www. mayoclinic.com (cited August 2007); A. Rocco and G. Nardone, “Diet, H. Pylori Infection and Gastric Cancer: Evidence and Controversies,” World Journal of Gastroenterology (June 7, 2007). Claudia Winograd University of Illinois at Urbana-Champaign
Stomach Disorders Stomach disorders describe a multiplicity of maladies either restricted to the stomach or emanating from the stomach, affecting contiguous portions of the gastrointestinal tract or other organ systems. The many disorders of the stomach can be categorized into several broad classifications, including conditions due to acid peptic disease with or without reflux; conditions of a neoplastic nature (tumor); conditions due to dysmotility; and conditions relating to gastric hemorrhage. Acid peptic disease encompasses gastric disorders from the most mild (dyspepsia) to severely erosive gastritis with frank ulceration (with or without perforation) and/or erosive esophagitis with ulcerations and premalignant mucosal changes. Dyspepsia is defined as a heartburn type of pain and patients may report upper abdominal bloating in the epigastrium (upper central abdomen) that is recurrent. If dyspepsia occurs more than once weekly the patient is said to be presenting with gastroesophageal reflux disease (GERD) unless proven otherwise. Obviously the diagnostic features of the two conditions overlap, thus making the clinical diagnosis difficult to document. The overall medical management of dyspepsia includes life-style modification (alcohol, nicotine, and caffeine cessation). This may significantly decrease dyspepsia symptoms and this requires patient adherence to the program. The prescribing of H2 antagonists will suppress the production of stomach acid, thus increasing the pH of the stomach (making the pH more alkaline). While proton pump inhibitors (PPI) are more potent, will suppress the acid much more completely and are considered the drugs of choice by most gastroenterologists, the cost of these drugs makes them unaffordable
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to many patients. This is due to some insurance companies refusal to pay for the PPI’s until the patient has failed to obtain relief from over-the-counter omeprazole (PPI) and highest doses of generic H2 antagonist, generally over the course of four to six weeks. A test for H. pylori (helicobacter pylori) bacteria is performed by a breath ammonia test, serologic H.pylori testing, or possibly a stool antigen test. This bacteria can cause ulcers to develop and if the test is positive, treatment with one of several regimens (PPI and Amoxicillin [or clarithromycin if penicillin-allergic], and bismuth, for example) will generally eradicate the bacteria and increase the likelihood that treatment for the dyspepsia will be effective and prevent ulcers. If the patient fails to obtain relief from the dyspepsia over the course of two weeks, many authorities recommend an upper gastrointestinal endoscopy although there is debate over the yield of endoscopy in young patients (younger than 55) due the rarity of adenocarcinoma in the younger population. Upper GI endoscopy is a direct visualization of the esophagus, stomach, and upper portion of the duodenum through a fiberoptic tube with the patient under conscious sedation. Abnormal tissue (tumors, ulcers, etc.) can be identified and,
An X-ray of the gastrointestinal tract, where a multiplicity of maladies can occur from stomach disorders.
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with the aid of flexible biopsy forceps, tissue samples can be obtained for pathological analysis. If generalized erythema (redness) of the gastric mucosal lining is observed, then gastritis is the reason for the dyspepsia and the H2 antagonists or PPI’s are continued. Gastroesophageal reflux disease is diagnosed when the patient reports persistent heartburn, especially after eating a spicy or greasy meal and complains of substernal chest pain and a bitter regurgitation of acidic fluid from the lower esophageal segment into the throat (water brash). This is frequently the reason for halitosis, a globus feeling (a sore fullness in the back of the throat), and hoarseness. If the GERD continues, the mucous membrane of the lower esophageal segment (which has no thick mucous protective secretions) begins to change due to the constant acid contact and the tissue becomes more like the gastric mucosa. This transition to abnormal tissue (Barrett’s esophagus) is actually a precursor to carcinoma of the esophagus. Deep erosive esophageal ulcerations may develop in severe and untreated cases. Modification of lifestyle is essential including discontinuation of alcohol ingestion, tobacco use, caffeine consumption and avoidance of ulcerogenic medications, such as the non-steroidal anti-inflammatory drugs. Elevation of the head of the bed to 45 percent at night will mechanically help the gastric contents to remain below the lower esophageal segment. Potent acid suppressors (PPI or H2 antagonist) are the mainstay of medical management of dyspepsia or GERD. Patients who fail to respond to the medical approach may undergo the Nissen fundoplication (via open laparotomy or laparoscopy), a surgical procedure to wrap the stomach up around the lower esophageal segment to create a physiologic valve to decrease the gastric acid reflux. Fifty percent of patients will generally present with complaints of midepigastric pain, somewhat relieved by food ingestion. The pain of peptic ulcers is vague and has been described as gnawing, cramping, burning and hunger-like. Peptic ulcer disease (gastric ulcer or duodenal ulcer) is now largely a medically managed disease. In the pre-PPI and H2 antagonist era, bland diets, the milk diet, and cryotherapy of the stomach lining were all attempted and are listed here for historical interest as they all are antiquated therapies. Gastric surgery including pyloroplasty (to open the narrowed pylorus caused by the excessive acid and
scarring) and segmental vagotomy was performed to decrease the amount of acid stimulated by the vagus nerve (Cranial Nerve X). At the present time, surgery is now reserved for those patients who have not responded to aggressive medical therapy, have not adhered to the therapy, or have had no treatment and present with a perforated peptic ulcer. Surgery at that point is generally directed at patching the perforation with the omentum, a sheet of fat covered by peritoneum (inner abdominal membrane) that hangs from the stomach. Vagotomy and pyloroplasty may still be considered in patients in whom recurrence or non-adherence to therapy is considered likely. In a ten year longitudinal study following 159 patients (who had undergone vagotomy and pyloroplasty for a perforated duodenal ulcer) 5.5 percent died perioperatively, 8.8 percent had recurrence of the ulcer, and 16 percent had diarrhea and dumping syndrome, and 90 percent had overall good to excellent results. Currently, medical treatment includes documentation of an ulcer by upper gastrointestinal (UGI) endoscopy, a biopsy, and the H. pylori test. In one metaanalysis review, duodenal ulcers recurred less than 10 percent of the time if treatment for H. pylori was instituted as compared to 65 percent–95 percent of the time in the absence of H. pylori treatment. Without treatment for H. pylori, recurrence is expected. Much like treatment for GERD and other acid peptic disease, treatment for H. pylori is essential and life style changes are mandated for best recovery and therapy is initiated using H2-antagonists or proton pump inhibitors. After approximately eight weeks of therapy, the patient should undergo a repeat UGI endoscopy to document healing. Intermittent administration of acid suppressers on an indefinite basis is commonly utilized to maintain the patient symptom-free. In dumping syndrome, food travels too quickly from the stomach to the distal small intestine without the proper chemical and mechanical preparation and the patient will experience feelings of nausea, bowel urgency, and sweatiness. This can occur after removal of the gall bladder or after bariatric or weight loss surgery, especially if the patient does not follow the prescribed diet very closely. Prolonged gastric emptying (gastroparesis) can occur due to neurologic abnormalities secondary to diabetes (in some studies present in 40 percent of dia-
betics, Type I or Type II), or in scleroderma (systemic sclerosis). Certain medications, such as tricyclic anti-depressants, anti-psychotics, and other sympathomimetic drugs such as certain alpha-agonist antihypertensive medications can also cause this condition. Treatment of delayed gastric emptying should be tailored toward the cause such as regaining tight diabetic control, review of the patient’s medication regimen, and sometimes the addition of pro-kinetic agents such as metoclopramide to encourage the coordinated movement of the stomach and relaxation of the pyloric sphincter to encourage the forward passage of stomach contents. Worldwide, gastric cancer is estimated to be newly diagnosed in 870,000 people and will cause an estimated 650,000 deaths in 2006. In the United States in 2006, approximately 21,860 patients will be newly diagnosed and 11,430 will die from the disease. Worldwide there has been a decline in the rate of new cases, although the actual numbers of new cases continues to climb, probably because of increasing longevity. The highest incidence (60 percent) of gastric cancers occurs in developing countries. The highest incidence of gastric cancers occur in eastern Europe, eastern Asia, South America and the lower incidences are documented in North America, southeast Asia, northern Europe, and Africa. Hypotheses about the cause of the regional differences and the recent declines in occurrence include eradication of the recognized gastric carcinogen H. pylori, culturally differing dietary intake, better nutritional knowledge, and better sanitation and storage of food (refrigeration vs. salt-curing of meats). Diagnosis of gastric cancer is made by early screening high risk individuals through UGI endoscopy and surgical intervention. See Also: Peptic Ulcer; Stomach Cancer. BIBLIOGRAPHY. American Gastroenterological Association, “AGA guideline: “Dyspepsia,” Gastroenterology (v.129, 2005); Michael Camilleri, “Etiology and Diagnosis of Delayed Gastric Emptying,” www.uptodate.com, (cited August 2006); Annie On On Chan, and Benjamin Chun Yu Wong, Risk Gactors for Gastric Cancer,” www.uptodate.com, (cited August 2006); Annie On On Chan, and Benjamin Chun Yu Wong, “Epidemiology of gastric cancer,” www.uptodate. com (cited August 2006); Annie On On Chan, and Benjamin Chun Yu Wong, “Screening for Gastric Cancer,” www.
Streptococcal Infections
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uptodate.com, (cited August 2006); Stephen J. Ferzoco, and Stanley W. Ashley, “Surgical Management of Complications of Peptic Ulcer Disease,” www.uptodate.com, (cited September 29, 2006); Rome Jutabha, and Dennis M. Jensen, “Major Causes of Upper Gastrointestinal Bleeding in Aadults,” www.uptodate.com (cited September 29, 2006); Peter J. Kahrilas, “Medical Management of Gastroesophageal Reflux Disease in Adults,” www.uptodate.com (cited September 21, 2006); John E. Pandolfino, and Peter J. Kahrilas, “Helicobacter Pylori and Gastroesophageal Reflux Disease”, www.uptodate.com (cited September 15, 2006); Paul C. Schroy, III, “Clinical Features and Diagnosis of Gastric Cancer,” www.uptodate.com (cited August 2006); Andrew H. Soll, “Overview of the Natural History and Treatment of Peptic Ulcer Disease,” www.uptodate.com (cited September 29, 2006); Steven D. Schwaitzberg, “Surgical Management of Gastroesophageal Reflux in Adults,” www. uptodate.com (cited September 21, 2006). Richard K. Ogden, D.O., FACOFP, FAAFP Kansas City University of Medicine and Biosciences
Streptococcal Infections Streptococcus species are spherical gram positive bacteria that grow in chains or pairs. Streptococcus species are a major cause of human disease and are the etiologic organisms for many cases of meningitis, pneumonia, sepsis, endocarditis, strep throat, and necrotizing fasciitis. Streptococcus may cause disease in both immune competent and immune compromised hosts. Streptococcus species are classified into alpha-hemolytic or beta-hemolytic groups based on how they break down red blood cells in vitro. Beta-hemolytic species are further classified according to Lansfield Groups A through O. Important human disease causing Alpha-hemolytic species include S. pneumoniae and S. viridans. Common human disease causing Beta-hemolytic species include Groups A and B. S. pneumoniae is responsible for the majority of Streptococcal disease world wide and is a major cause of childhood and adult morbidity and mortality. Clinical manifestations of S. pneumoniae infections in neonates and young infants are serious and include pneumonia, meningitis, sepsis, bacteremia,
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otitis media, abscesses, and bone and joint infections. Worldwide, it is the most common cause of bacterial pneumonia mortality and the most severe cause of bacterial meningitis. Pneumococcal disease kills up to 1 percent of all children born in high mortality areas, and pneumococcal meningitis leaves approximately 50 percent of surviving children with life-long neurologic disabilities including deafness and seizures. According to the Centers for Disease Control, underlying co-morbidities such as HIV infection, malnutrition, and sickle cell anemia significantly increase risk of invasive pneumococcal disease by up to 50 percent. The World Health Organization estimates that more than 1.6 million people die of pneumococcal disease annually and that half of these deaths are of children under 5 years of age. The vast majority of these deaths occur in the developing world where there is currently limited access to potentially lifesaving pneumococcal vaccines. Although common and often serious, pneumococcal disease is largely preventable by vaccination. The first pneumococcal conjugate vaccine was licensed in the United States in 2000. It includes purified capsular polysaccharide of the seven serotypes of S. pneumoniae most common in the United States. Studies have shown the conjugate vaccine to be safe and effective in highly effective; the vaccine’s introduction has significantly decreased both infant and childhood pneumococcal disease due to vaccine serotypes. Perhaps equally important, the vaccination of infants has resulted in ‘herd immunity’ and thus reduced transmission of the bacterium to adults thereby decreasing pneumococcal morbidity and mortality in the elderly. Trials in The Gambia and South African have demonstrated the vaccine to also be effective in developing world settings. While the pneumococcal conjugate vaccine is routinely given in most developed countries, its use remains poor in the developing world. Other human disease causing Streptococcal species include S. viridans and Beta-hemolytic groups A, and B. S. viridans is a cause of endocarditis and dental abscesses. Group A Beta-hemolytic streptococcus, also known as S. pyogenes, is the cause of strep throat and scarlet fever. Group A streptococcus is frequently the cause of necrotizing faciitis (also known as flesh eating disease) which has high levels of morbidity and mortality even with prompt and appropriate treatment.
Rheumatic fever is an immune mediated inflammatory disease triggered by Group A streptococcus. While no longer common in the developed world, it remains a leading cause of acquired heart disease worldwide. Group B streptococcus is a normal colonizer of the female reproductive tract and may cause neonatal sepsis and meningitis. Current recommendations by the CDC are for pregnant women to be tested for Group B streptococcus and given antibiotics during labor to reduce the risk of transmission to the infant. There are no vaccines available for non-pneumococcal streptococcal species and antibiotics remain the cornerstone of therapy. However, antibiotic resistance, particularly among pneumococcal species, to first line agents is becoming increasingly common necessitating the use of newer and more expensive drugs. Antibiotic resistance is of particular concern in the developing world where second and third line agents may not be readily available. SEE ALSO: Bacterial Infections; Bacteriology; Pneumonia;
Menigitis.
BIBLIOGRAPHY. Centers for Disease Control, “Streptococ-
cal Infections”, www.cdc.gov/ncidod/diseases/submenus/ sub_streptococcus.htm (cited September 2006).
Shaun K. Morris, MD, MPH Independent Scholar
Stress In medical and psychological sciences, stress is a term used to describe a person’s physiological, behavioral, cognitive, and emotional responses to events that are evaluated and appraised as threatening and challenging. Physiologically, stress is the nonspecific response of the body to any demand made on it. Stress causes a psychophysiological response called the general adaptation syndrome (GAS)—first described in 1936 by Hans Selye in the journal Nature. Stress mainly refers to the mental or emotional response of upset occurring in an individual in response to these adverse external stimuli. Through his research, Selye was able to separate the physical effects of stress from other physical symptoms suffered by
patients. He observed that patients suffered physical effects not caused directly by their disease or by their medical condition. There are two basic types of stress: eustress (positive stress) and distress (negative stress), roughly meaning challenge and overload. In some cases, stress in and of itself is neither positive or negative. It is more the way that a person responds to the event that determines whether it has a positive or negative impact. Sometimes, the same stressful event will be positive for one person and negative for another. For example, two skiers who suddenly find themselves on a steep slope may respond very differently. One may enjoy the excitement of the unanticipated challenge, whereas the other may be in fear and terror that they will be unable to negotiate the terrain. When the word stress is used alone, typically it is referring to distress. Medical, Psychological, and Everyday Understanding of Stress Physiological stimuli or conditions such as a sudden loud noise, lack of air, or the presence of disease can be considered stress. Likewise, psychological conditions such as concern about one’s job, one’s future, a loved one, or a particular interpersonal relationship can be considered stress. In this later sense, stress is viewed as roughly the opposite of relaxation or serenity. Serenity is defined as a state in which an individual is disposition-free or largely free from the negative effects of stress. In some cultures, it is considered a state that can be cultivated by various practices, such as meditation, relaxation, physical disciplines such as tai chi chuan and hatha yoga, and other forms of training. Stress can directly and indirectly contribute to general or specific disorders of body and mind. Stress can have a major impact on the physical functioning of the human body. Such stress raises the level of adrenaline and corticosterone in the body, which in turn increases the heart rate, respiration, and blood pressure and puts more physical stress on bodily organs. Long-term stress can be a contributing factor in heart disease, high blood pressure, stroke, muscle tension, cancer, mental disorders, and other illnesses. Stress can be very useful in certain situations. For example, fear can be an enormous source of power when someone needs to flee from a dangerous situation or use greater-than-average physical abilities. Stress can
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also be the catalyst for someone to change his or her way of thinking, thus changing old patterns that do not work in his or her life to new more healthy ones. About the time of Selye’s work, the gradual realization dawned that such concepts as anxiety, feeling of antagonism, tiredness, frustration, overwork, premenstrual tension, overfocusing, confusion, mourning, and fear could all come together in a general broadening of the meaning of the term stress. The popular use of the term in modern folklore expanded rapidly, spawning an industry of pop psychology, selfhelp, personal counseling, and sometimes quackery. The use of the term stress in recognized cases such as those of post-traumatic stress disorder (PTSD) and psychosomatic illness has scarcely helped clear analysis of the generalized “stress” phenomenon. Nonetheless, some varieties of stress from negative life events, or distress, and from positive life events, or eustress, can clearly have a serious physical impact distinct from the troubles of what psychotherapists call the worried well. Stress responses can activate the sympathetic nervous system and release of stress hormones, including adrenaline/epinephrine and cortisol. Sympathetic nervous output tends to divert blood flow to the large muscle—the body “thinks” it has to run away from something or fight something: the so-called flight/ fright syndrome of ancient evolutionary heritage— and blood flow is correspondingly less to the bowel and other nonmuscle organs. The effects are easily recognized: dry mouth, motor agitation, sweating, pallor, enlarged pupils, and insomnia. Our modern lifestyle tends to cause continual sympathetic nervous system activation with very little opportunity for the parasympathetic nervous system to activate. When this system is active, the bowel and other nonmuscle organs get good blood flow, the pupils constrict, and the glands all function well and secrete their various compounds. Absence of parasympathetic activation leads to poor digestion and probably also to poor healing and organ function. It is vital to take time out from our modern lifestyles to allow for rest and proper parasympathetic action in our bodies. Medical Perspective As a medical term, stress refers to a wide range of strong external stimuli or conditions, both physiolog-
1620 Stress ical and psychological, impinging on an individual. GAS is a typical series of responses to stressful situations that includes alarm, resistance, and exhaustion. Selye described GAS as having three stages: • Alarm reaction, where the body detects the external stimuli. In this stage, humans exhibit what is called the “fight of flight” response, which puts a person in a highly alert state. This response can also decrease the body’s immune system, making it more susceptible to disease, emotional or mental difficulties, etc. • Adaptation, where the body engages defensive countermeasures against the stressor. In this stage, humans adapt to the stress that they are exposed to. For example, if a person is deprived of food, he or she may adapt by a corresponding desire for less activity. Persons may also attempt to adapt in more negative ways, such as alcohol or drugs, or in positive ways such as more exercise or relaxation to adapt to the stress. • Exhaustion, where the body begins to run out of defenses. In this stage, humans tend to experience movement to some type of pathology or combination of pathologies. The four main responses could be cardiovascular (such as heart attack or stroke), musculoskeletal (such as joint problems, stiffness, etc.), neurological (which could include drug addiction, alcoholism, or mental disorders), or internal organ diseases. Physiology and Biochemistry A response to stress includes the endocrine system and nervous system preparing the body for action. The hypothalamic-pituitary-adrenal axis is a major part of the neuroendocrine system, involving the interactions of the hypothalamus, the pituitary gland, and the adrenal glands. The hypothalamic-pituitary-adrenal axis plays a primary role in the body’s stress reactions by balancing hormone releases from the adrenaline-producing adrenal medulla and from the corticosteroidproducing adrenal cortex. The body reacts to external and/or internal stressors by releasing catecholamine hormones, epinephrine, norepinephrine, glucocorticoid hormones, cortisol, and cortisone. Psychosomatic Diseases Stress can directly and indirectly contribute to general or specific disorders of body and mind. Stress can
have a major impact on the physical functioning of the human body. Such stress raises the level of adrenaline and corticosterone in the body, which in turn increases the heart rate, respiration, and blood pressure and puts more physical stress on bodily organs. Long-term stress can be a contributing factor in heart disease, high blood pressure, stroke, muscle tension, cancer, mental disorders, and other illnesses. Post-traumatic stress disorder (PTSD) is the type of experience in which victims of major catastrophes or strong personal stressors feel long-lasting effects that may include reexperiencing the event in vivid flashbacks and/or dreams. PTSD is a disorder that results from exposure to a major stressor, with symptoms of anxiety, guilt, nightmares, sleep disturbances, reliving the event, concentration difficulties, and other psychological problems, lasting for more than one month. Psychological Perspective Any factor that causes stress is called a stressor. Stressors are the antecedants for and sources of stress. Pressure, uncontrollable events, frustration, conflict, poverty, job problems, catastrophes (earthquakes, hurricanes, tornados), major life events, acculturation process, everyday hassles (background stressors) can be a source of stress. In general, there are two kinds of stressors: processive stressors and systemic stressors. Processive stressors are elements in the environment (for example, elevated sound levels or intense light) perceived by the organism as potential dangers. These do not cause damage directly but are processed in the cerebral cortex. The processed information is then sent via the limbic system in the hypothalamus, where they activate the supreme centers of the autonomic nervous system. This results in the fightor-flight (or sympathetico-adrenal) response. Occupational and financial stressors in humans are an example of a processive stressor. Systemic stressors are those that pose an immediate and serious threat to the organism’s homeostasis, such as extreme temperature, water deprivation, immune system threats, as well as tissue necrosis, hypotension, or hypoxia. These require less cognitive processing than processive stressors. Often, both types of stressors occur simultaneously. They are usually accompanied by intense emotions.
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Primary and Secondary Appraisal of a Stressor The first step in appraising a stressor is called primary appraisal, which involves estimating the severity of the stressor and classifying it as a threat, challenge, harm, or loss. In secondary appraisal, people have identified a threat or harmful effect and must estimate the resources that they have available for coping with the stressor. Resources may include social support, money, time, energy, ability, or any number of potential resources, depending on the threat. If resources are perceived as adequate or abundant, the degree of stress will be considerably less than if resources are missing or lacking. Health Psychology: Stress and Illness Health psychology is a new scientific discipline. It is the subfield of psychology devoted to understanding how psychological and social variables affect health and how humans respond when they become ill.hp focus on how emotions, social factors, and behavior influence health and illness. They develop programs to reduce the levels of risk factors related to diseases. Stress and Adjustment A normal part of life, stress can lead to a positive response by a person, leading to increased knowledge and personal growth, or it can result in psychological or physiological problems. Prolonged stress, not managed well, can be particularly damaging. Individuals who deal with stress in inappropriate ways—drugs, alcohol, eating, smoking, promiscuity, lashing out at others, depression, and so forth—can harm their body and actually make the stress or its reoccurrence worse. More appropriate preventive and coping measures include regular exercise, meditation, prayer, relaxation techniques, and lifestyle chages. Individuals can respond very differently to the same stressor. Any given situation can cause eustress in one person and distress in another. Contributing factors for the diverse responses include differences in physiology and life circumstances, different outlooks on life, as well as different methods of stress management. Methods of coping that work well in childhood situations often become ingrained and habitual, and often follow the child into adulthood. In the adult world, these skills can be quite inappropriate, and stress heightens as the person clings to ob-
Individuals who deal with stress in inappropriate ways such as drugs or alcohol, can harm their body and actually make the stress worse.
solete behaviors. However, new skills can be learned, and poor coping methods replaced. Treating or managing stress usually falls into three approaches: A person can (1) reduce or eliminate the stressor, (2) respond to the stress in a different way, or (3) relieve the stress through a variety of techniques. Most stressors can be responded to in a different way. Whether it is choosing to not react with anger to certain situations, learning to overcome fears, learning to not be so emotionally upset, or setting new priorities, persons usually have some choice in how they respond to stressors. When it is impossible to avoid a stressor and/or new ways or responding to a stressor are not enough, a person can always schedule time to relieve his or her stress. A person may schedule activities to relieve stress such as tai chi chuan, yoga, aerobic exercise, massage, listening to music, aromatherapy, biofeedback, and meditation. For example, when Selye reviewed the physiological changes measured in practitioners of transcendental meditation (TM), he concluded that such changes were the opposite of the body’s reaction to stress. The therapeutic effect of TM was most distinct in people whose coping skills were poorly adapted to the stress of daily life. Persons who manage stress well are often risk takers who do not react negatively to uncertainty, people
1622 Stress who are internally motivated as opposed to being motivated by external factors, and people who take responsibility for creating outcomes they want in life as opposed to hoping that they might occur. A number of psychological and sociological factors have been consistently demonstrated to act as a moderator against stress in the development of chronic psychological or physical disease (such as depression or hypertension). Among these many factors are optimism or hope, social support, socioeconomic status, and sense of community.
When experiencing stress, a person uses psychological defense mechanisms—unconscious distortions of reality perception—in order to reduce stress, internal conflict, anxiety, and the feeling of frustration. Up to now, four dozen psychological defense mechanisms have been described. Denial, repression, rationalization, regression, compensation, sublimation, projection, reaction formation, displacement, and identification are the most universal ones. These defense mechanisms have their unique expression in most cultures.
Coping with Stress: Adjustment Strategies and Defense Mechanisms Various cognitive and behavioral efforts to control stress are called coping. Some coping strategies (e.g., avoidance) are considered negative coping; some are considered positive (such as relaxation and meditation techniques or physical activity). Coping strategies are actions that people can take to master, tolerate, reduce, or minimize the effects of stressors, and they can include both behavioral strategies and psychological strategies. Psychologists differentiate problem-focused coping and emotion-focused coping. When using problem-focused strategies, the person works on eliminating or changing the stressor itself through his or her own actions, or tries to eliminate the source of stress or reduce its impact through direct actions. In emotion-focused coping, the person tries to change the impact of stressor by changing his or her emotional reaction to the stressor. Most people use both types of coping, depending on the situation. Emotional-focused coping is more useful when the person has more or less control over the stressful event. Personality type is also a major determinant in stressful events and situations. In clinical psychology, type A, type B, type C, and type H (or hardy personally) are differentiated. Type A is the person who is ambitious, time conscious, extremely hardworking, and tends to have high levels of hostility and anger as well as being easily annoyed. Type B is the person who is relaxed and laid back, less driven, and competitive than type A, and slow to anger. Type C is the pleasant but repressed person who tends to internalize his or her anger and anxiety and who finds expressing emotions difficult. Hardy persons (type H) seem to thrive on stress but lack the anger and hostility of the type A persons.
See Also: Acupuncture; Anxiety Disorders; Alcohol-
ism; Depression; Drug Abuse; Exercise/Physical Fitness; Smoking.
BIBLIOGRAPHY. F. Alexander, Psychosomatic Medicine (Norton, 1950); A. Antonovsky, Health, Stress, and Coping (Jossey-Bass Publishers, 1979); M. K. Chatuverdi, Human Stress and Stressors (Cosmo Publications, 1983); R. R. Grinker and J. P. Spiegel, Man under Stress (Blakiston, 1945); M. J. Horowitz, Stress Response Syndromes (Aronson, 1976); J. S. House, Work, Stress and Social Support (Addison-Wesley, 1981); J. M. Ivancevich and M. T. Matteson, Stress and Work: A Managerial Perspective (Blenview, 1980); I. L. Janis, ed., Personality Dynamics, Development and Assessment (Harcourt, 1969); S. Jeshmaridian, “PostSoviet Therapists’ Attitudes in Interpreting Public Mental Health,” European Journal of Public Health (v.12/4, 2002); A. Kalayjian, Disaster and Mass Trauma: Global Perspectives on Post Disaster Mental Health Management (Vista Publishing, 1995); W. E. Kelly, Post-Traumatic Stress Disorders and War Veteran Patient (Brunner-Routledge, 1985); H. W. Krohne and L. Laux, eds., Achievement, Stress and Anxiety (Hemisphere, 1982); R. S. Lazarus, Psychological Stress and the Coping Process (Prentice, 1979); D. Mechanic, Students under Stress: A Study in the Social Psychology of Adaptation (University of Wisconsin Press, 1978); C. J. L. Murray and A. D. Lopes, The Global Burden of Disease (Harvard University Press, 1996); B. Raphael, When Disaster Strikes (Hutchinson, 1986); H. Selye, The Stress of Life (McGraw, 1956); H. Selye, The Stress of My Life. A Scientist’s Memoirs (Reinhold, 1979); C. Spielberger, “Stress, Emotions and Health,” Proceedings from the 8th European Congress of Psychology, 2003; S. H. Sukiasyan, et al., Stress and Post-Stress Disorders: Personality and Society (Yerevan, 2003); R. Totman, Social Causes of Illness (Pantheon Books, 1979); G. Van der Veer,
Substance Abuse and Mental Health Services Administration (SAMHSA)
Psychotherapy with Refugees (SCS, 1993); H. Wolff, Stress and Disease (Charles C. Thomas, 1968). Samvel Jeshmaridian, Ph.D. American Psychological Association
Stroke Strokes, also called cerebrovascular accidents (CVAs), are an important cause of death and disability around the world, being in the top three causes of death and one of the leading causes of disability in the United States. Strokes can be of two types— ischemic or hemorrhagic—but both cause a sudden neurologic change, such as weakness, blindness, confusion, or numbness due to injury to brain cells. Historically, no cure for stroke could be given, but in recent years, several methods of treating acute stroke have been developed. A CVA is caused when brain cells are injured, either by cutting off the blood supply to those cells or by bleeding into the brain. The first type is called an ischemic stroke and is the most common, accounting for 85 to 90 percent of strokes. It is caused by occlusion of a blood vessel supplying the brain. Several medical conditions can cause these clots, for instance, certain heart problems (such as atrial fibrillation, heart valve problems, or even heart attacks) may cause tiny blood clots to be made in the heart and travel to the brain, or cholesterol deposits in blood vessels within the brain may occlude the vessel. Diseases in which the blood is more prone to clot, such as certain cancers or hereditary blood clotting disorders, may also cause ischemic strokes. Hemorrhagic strokes are caused by bleeding into the brain, usually caused by damage to a blood vessel. These types of strokes are less common, comprising only 10 to 15 percent of strokes, but are more dangerous. They are most often caused by high blood pressure. The continual high pressure in the blood vessels leads to vessel weakening and possibly hemorrhage. These two types of strokes have similar symptoms but very different treatments, so a computed tomography (CT) scan of the head is needed to determine which type has occurred. Symptoms of both types of stroke include sudden weakness, inability to speak or read, numbness,
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or blindness. Usually, these symptoms occur on only one side of the body at a time. Symptoms can wax and wane, leading many patients to deny their severity and delay getting treatment. Treatment for ischemic stroke is a relatively new development and includes giving special medicine called thrombolytics or clot busters to destroy the clot. These medicines can be dangerous to use, so they can only be given by specially trained doctors and nurses to patients who meet certain criteria. In addition, these medicines only work if they are used within three hours after the first stroke symptoms have appeared. Many new treatments are currently being developed for ischemic stroke, involving direct removal of the clot by a mechanical device or by targeted administration of clot-busting drugs. Hemorrhagic strokes are mainly treated by controlling blood pressure and correcting any bleeding abnormalities. Occasionally, surgery is done to take out the blood accumulation. Clot buster drugs are extremely dangerous in this form of stroke and so cannot be used. After a stroke has occurred, two other important aspects of treatment include physical therapy to maximize recovery of any lost abilities, and also prevention of future strokes. SEE ALSO: Brain Injuries; National Institute of Neurologi-
cal Disorders and Stroke (NINDS).
BIBLIOGRAPHY. Christopher Goetz and Eric Pappert, Textbook of Clinical Neurology, 2nd ed. (Saunders, 1999); Lee Goldman and Dennis Ausiello, Cecil Textbook of Medicine, 22nd ed. (Saunders, 2003).
Cara Sedney West Virginia University
Substance Abuse and Mental Health Services Administration (SAMHSA) The Substance Abuse and Mental Health Services Administration (SAMHSA) helps people at risk for mental or substance abuse to formulate strategies to
1624 Sudan prevent succumbing to disorders and/or to facilitate recovery for those who already struggle with them. To that end, SAMHSA creates programs, formulates policies, and provides grants to facilitate life in the community for everyone. Established by Congress in 1992, SAMHSA reports to the U.S. Department of Health and Human Services (HHS). The agency takes measurable actions to help people at risk to find and keep employment, live in stable homes, and develop and/or maintain relationships with friends and family. According to SAMHSA’s National Survey on Drug Use and Health, nearly 20 million Americans, aged 18 and older, could benefit from mental health services and substance abuse treatments, but are instead, living with significant mental health issues. SAMHSA states that costs of untreated mental health and substance abuse disorders are staggering, when including lost employment opportunities and shattered relationships. The agency takes the position that these disorders are treatable, chronic conditions and that these frequencies and severities can be greatly reduced through prevention and intervention programs based upon results of scientific research. SAMHSA, therefore, shares the results of its research to provide information and hope for recovery. Operating from three centers and supporting office facilities, SAMHSA has an annual budget of over $3 billion. With these funds, SAMHSA provides grants to relevant research projects and funds state-level programs that create, expand, or enhance treatment programs; and/or increase the quality of local, community-based programs. Recipients of these funds must prove positive outcomes through stated, measurable program success parameters. SAMHSA’s Center for Mental Health Services (CMHS) works on expanding community-based treatment programs for adults with significant mental illnesses and children showing signs of serious emotional disturbances. Funds are provided to quality treatment programs through the Mental Health Services Block Grant, and other programs. CMHS collects data on mental health issues in the United States and provides analyses. Another SAMHSA center, the Center for Substance Abuse Prevention (CSAP), promotes and improves substance abuse prevention programs. CSAP gives funding to states and communities to strengthen
preventative efforts. The Center for Substance Abuse Treatment (CSAT) works with state and local governments to expand existing treatment facilities and services through their Substance Abuse Prevention and Treatment Block Grant Program. SAMHSA provides written materials to educate policy makers, healthcare professionals, and the general public. In “A Life in the Community for Everyone—Reducing Substance Abuse in America: Building the Nation’s Demand Reduction Infrastructure—A Framework for Discussion,” SAMHSA discusses founding principles of its treatment philosophies with substance abuse. In “From Exclusion to Belonging: Transforming Mental Healthcare in America,” SAMHSA shares its perspective on mental health issues in the United States. The agency has also created a program and accompanying materials for parents to educate their children about the dangers of substance abuse: A Family Guide: Keeping Youth Mentally Healthy and Drug Free. SEE ALSO: Drug Abuse; Mental Health. BIBLIOGRAPHY. Substance Abuse and Mental Health
Services Administration (SAMHSA), www.samhsa.gov. (cited July 2007); Lorri A. Zipperer, ed., The Health Care Almanac: A Resource Guide to the Medical Field (American Medical Association, 1995). Kelly Boyer Sagert Independent Scholar
Sudan Sudan is located in northeastern Africa with a coastline on the Red Sea. It is the largest state in Africa by territory, sharing borders with nine other countries, and it is the tenth largest country in the world. The region has suffered through two long periods of civil war since the 1970s. There has been an ongoing humanitarian crisis in the western region of Darfur, with the United Nations estimating that 400,000 Darfuri may have already died in raids by local militia since 2003. Millions have been displaced to nearby Chad. The population of Sudan is 39,379,000 and growing at 2.08 percent annually. The birth rate is 34.86 per
1,000 and the death rate is 14.39 per 1,000. Median age is 18.7 years. Life expectancy is 48.24 years for males and 50.03 years for females. Gross national income is $640, with about 40 percent of the population living below $1 day. Eighty percent of the population engages in agriculture. Malaria is the leading cause of morbidity and mortality in Sudan, with around 40 percent of outpatient medical visits and 30 percent of inpatient hospital admission stemming from the virus. There were around 3 million known cases in 2004 alone. Regionally, there is a risk of dengue fever and African trypanosomaisis (or sleeping sickness), as well as schistosomiasis and meningococcal meningitis. Diarrhea is also prevalent, with less than 40 percent of the population of southern Sudan with clean water and waste disposal. Displacement and drought has led to food insecurity across the region. In 2006, 2.5 million in Darfur and 3 million in the South needed supplemental food. The World Health Organization currently estimates that 22 percent of Sudanese children suffer from acute malnutrition. AIDS surveillance within Sudan is poor, and estimates of the HIV+ population vary. UNAIDS puts the prevalence rate at 1.9 percent of adults, but it may be significantly higher. The country does suffer from a high rate of tuberculosis, with an estimate of 379 infections per 100,000 and 63 deaths per 100,000. Sudan reports an 81 percent cure rate for TB. This poor health profile, limited sanitation, and violence against groups like the Darfuri has had a serious impact on the health of women and children. Almost 90 percent of Sudanese women have undergone female genital mutilation. For refugee women, especially those in Darfur, the risk of rape and violence is omnipresent. Only 10 percent of women use contraception, 60 percent have prenatal care, and 87 percent have a trained birth attendant during delivery. The maternal mortality rate is 1,500 deaths per 100,000 live births. Child mortality is high, with 62 deaths per 1,000 in those younger than 1, and 90 deaths per 1,000 in those aged 1-5 years. Approximately 1.8 million children in Darfur have been displaced by violence; there are 1.7 million orphans spread across the country. Medical care in Sudan is sharply divided between regions. In the North, there is a functioning medical system that most people can access when they are in need. In the South, only about 25 percent of the
Sudden Infant Death Syndrome (SIDS)
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population can find care. International agencies have entered the Darfur region to give aid and care to refugees, but continuing violence by militia has made it difficult for these groups to operate. SEE ALSO: Healthcare, Africa; Malaria; Bibliography. Central Intelligence Agency, “Sudan,” CIA
World Factbook. www.cia.gov/library/publications/theworld-factbook/geos/su.html (cited June 2007); EngenderHealth.com, “Country by Country: Sudan,” www.engenderhealth.org/ia/cbc/sudan.html (cited June 2007); The Joint United Nations Programme on HIV/AIDS, “Sudan,” UNAIDS: www.unaids.org/en/Regions_Countries/Countries/ sudan.asp (cited June 2007); Research Africa, “Sudan,” www.researchafrica.rti.org/index.cfm?fuseaction=home. country_view&country_id=35 (cited June 2007); United Nations Children’s Fund, “Sudan—Statistics,” www.unicef.org/infobycountry/sudan_statistics.html#28 (accessed June 19, 2007); World Health Organization, “Health Action in Crisis: Sudan,” www.who.int/hac/crises/sdn/background/Sudan_Dec05.pdf (cited June 2007). Heather K. Michon Independent Scholar
Sudden Infant Death Syndrome (SIDS) Sudden infant death syndrome (SIDS), also called crib death, is the sudden death of an infant less than 1 year old that cannot be explained by evidence collected during a investigation. SIDS is the leading cause of infant mortality between 1 month and 1 year of age (28 to 364 days as defined by the Centers for Disease Control and Prevention [CDC]). A thorough case investigation is needed and must include a complete autopsy, examination of the scene of death, and a review of the infant’s clinical history. However, an autopsy only reveals a diagnosis of SIDS in only 15 percent of suspected cases, leaving this phenomenon largely unexplained. Since the 1990s, research into the pathology and epidemiology of SIDS continues to contribute to its understanding. According to the CDC, SIDS accounts for approximately half of the 4,500 unexplained infant deaths in
1626 Sudden Infant Death Syndrome (SIDS) the United States each year and carries a risk of less than 1 per 1,000 live births. Slightly elevated rates of SIDS occur in African-American and Native-American infants, and in boys. Since the mid-1990s, the overall rate of SIDS in the United States has declined by more than 50 percent, with the greatest reduction occurring since the American Academy of Pediatrics (AAP) put forth the recommendation to place infants in the supine (on their back) position to sleep. Clinical Features and risk factors When an autopsy is performed on a suspected SIDS case, the findings usually include a well-developed and nourished child with blood-tinged nostrils, pulmonary congestion and swelling, and an inflamed upper respiratory tract. Occasionally, brain abnormalities are reported as well. Little is known about the precise mechanism of death, although bradycardia (slowed heart rate), decreased arousal, overheating, and the type of bedding all have been associated with SIDS deaths. A number of risk factors have been associated with SIDS. Among the most consistently identified factors are young maternal age, maternal smoking dur-
ing pregnancy, late or an absence of prenatal care, preterm birth and low birth weight, being placed in a prone (on their stomach) sleeping position, sleeping on a soft surface, and overheating. Additionally, two important maternal factors previously mentioned have been found to increase the risk of SIDS independently of birth weight: maternal smoking and a maternal age of less than 20 years. The connection between maternal alcohol and drug use and SIDS is currently under investigation. Infants born prematurely and who are consequently at a lower birth weight than those carried to term are three to four times more likely to die from SIDS. The sleeping position of premature infants is crucial; research demonstrated that preterm infants placed on their stomachs were found to be 24 times more likely to die of SIDS than normal-weight infants placed on their backs. In general, the prone (stomach) sleeping position has been found to be associated with the greatest risk of SIDS. The physical sleeping environment itself can also be a likely source of risks for SIDS. Soft sleeping surfaces such as a waterbed, sofa, or pillows and loose bedding items such as comforters and quilts may endanger the
Since the mid-1990s, the overall rate of SIDS in the United States has declined by more than 50 percent, with the greatest reduction occurring since the American Academy of Pediatrics (AAP) put forth the recommendation to place infants on their back to sleep.
Suicide
infant. Overheating due to an excess of blankets or swaddling is another potential threat to the infant. Parent–infant bed sharing also carries great risk for the child; sharing a room, however, appears to reduce the risk of SIDS so long as the infant remains in his or her own crib or separate sleep surface. Research on pacifier use has yielded results that suggest that it might be a protective factor against SIDS although the precise mechanism is unclear. Theories of Causation SIDS usually occurs between the second and fourth month of an infant’s life, a period marked by great change in cardiac and respiratory systems. A “triple-risk” model suggests that SIDS occurs only in infants who are already susceptible to SIDS via genetics or other abnormalities and who experience a suboptimal event (e.g., maternal smoking) at this fragile juncture of central nervous system and immune system development. The CDC has issued the following recommendations for reducing the risk of SIDS: infants should be placed to sleep on their backs and never on their stomachs; infants should be put to sleep exclusively in cribs or another safe, firm sleep surface such as a bassinet or cradle; soft objects such as pillows, stuffed animals, and loose blankets should be removed from the crib; smoking in the same room as the infant should be avoided; overheating should be avoided by dressing the infant appropriately for the temperature; only parents or caregivers should be allowed to co-sleep (sleep in the same bed as the infant) and should not be under the influence of alcohol or drugs.The AAP recommends putting the infant to sleep with a pacifier. Research using home monitors has not been able to prove their efficacy in preventing SIDS. SEE ALSO: American Academy of Pediatrics (AAP); Failure
to Thrive; Infant and Newborn Care; Premature Babies.
BIBLIOGRAPHY. Centers for Disease Control and Preven-
tion, “Sudden Infant Death Syndrome (SIDS),” www.cdc. gov/SIDS/index.htm (cited February 2007); Michael J. Corwin, “Sudden Infant Death Syndrome,” www.uptodate.com (cited February 2007). Lareina Nadine La Flair, M.P.H. Harvard University
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Suicide The term suicide comes from the Latin sui caedere (“to kill oneself ”), which is the act of willfully ending one’s own life. Originally, the word was used in the context of someone committing suicide, but now has come to be the verb with someone “suiciding,” and “a suicide” being not only the act but also, sometimes, describing the person. The reasons for someone committing suicide can be many. These may include people who are either suffering from great pain, or expect to be; people suffering from stress, especially grief or guilt after a death, gambling debts, and so forth; people trying to escape judicial punishment; people suffering from mental illness; or for extreme military, political, or terrorist purposes. The first of these reasons involves people in great physical or emotional pain, or expecting to suffer from pain, including those who have been diagnosed with incurable diseases such as cancer, multiple sclerosis, or other debilitating diseases, including paralysis, disfigurement, and/or loss of a limb. With many of these people wanting to commit suicide, this has been an extremely contentious area with arguments by ethicists over whether it should be a crime to help such people to end their lives, that is, to commit suicide. Stress resulting from grief, especially after a death, a major disaster, or guilt over something has also been a major cause of suicide. This can also have resulted from financial losses, especially from people suffering from gambling addictions, loss of job, or loss of assets (especially the family house) through business failure, or having lost money through a fall in stock market prices, such as on Wall Street in 1929. Often a person committing suicide for this reason does so in grief or shame, and may do so because of their inability to face their family or friends, and because of fear of the future without someone or assets. Most medical professionals feel that these people would not commit suicide if they had access to appropriate counselors, either professionals or members of their family, or friends. Suicide has occasionally been seen as a method of avoiding judicial punishment such as felons killing themselves by shooting, crashing their car, jumping over an abyss, and so forth, when they do not see a way of escaping from the police or other law enforcement of-
1628 Suicide ficials. Although this can be committed by people trying to avoid capital punishment, it might also be a person who would otherwise face a long term in prison. Large numbers of prisoners also commit suicide in prison because of the treatment they have received or to end the boredom of incarceration. Other prisoners have been known to commit suicide just prior to being executed: German politician Herman Goering killed himself by poison in 1946 to avoid being hanged and French collaborationist leader Pierre Laval tried to commit suicide to prevent his execution. There have also been many leaders since ancient times who have committed suicide to escape capture: Mark Anthony and Queen Boadicea being two from the ancient world; Adolf Hitler and Yukio Mishima being two from the 20th century. Many people suffering from mental problems and/ or depression have also been involved in committing suicide. Some with mental difficulties such as those with bipolar disorder and schizophrenia, have been known to have higher rates of suicide. There have also been people who have become depressed through adverse environmental conditions such as sexual abuse, homelessness, and bullying, or unresolved sexual issues such as after the breakup of a love affair, unrequited love, or rejection of people by their family over sexual orientation. The last major category of people committing suicide is people who kill themselves for military, extreme nationalist, political, or terrorist reasons. Although the number of these people is small, the publicity given to them in the media is very significant and, in fact, many argue that this helps contribute to the number of suicide bombers coming forward. It had always been seen as honorable for soldiers to die in battle rather than being captured. Examples include the men following the Roman reformer Catliline that refused to surrender at the battle of Pistoria in 62 b.c.e., the French Imperial Guard continuing to fight to the death at the Battle of Waterloo in 1815, and the French Foreign Legion at the Battle of Dien Bien Phu in 1954. The Japanese used Kamikaze bombers during World War II to devastating effect, striking terror into their opponents; the Imperial Japanese Army and Navy followed the chivalric code of Bushido whereby it was regarded as honorable to die and dishonorable to be captured. Indeed, many Japanese civilians on
Saipan and other islands also committed suicide rather than live under foreign rule. In recent years, some terrorist groups have used suicide bombers in conflicts in Sri Lanka, the Middle East, and on September 11, 2001, in the United States, which have resulted in large numbers of casualties and with no people who can be captured and punished afterward. According to official statistics, more men commit suicide than women, while more women attempt to commit suicide than men. This is largely because men often choose a more violent method of killing themselves, such as using guns, knives, hanging, and the like, whereas many women overdose on medication and can often be revived if medical care comes quickly enough. Many countries such as Australia have been keen to try to reduce the increasing rates of youth suicide which are statistically at a much higher rate of suicides in recent years than 80 or so years ago. This may be because there have been queries over old statistics of people having committed suicide because suicide is regarded by many religions as a mortal sin, with suicide victims not allowed to be buried in consecrated land in Christian countries. This has often led to judges and coroners to conclude that people died in an accident while cleaning their gun and so forth, rather than their having committed suicide. The main medical ethical concern over suicide has been whether doctors should be allowed to assist people wishing to commit suicide. Some doctors do feel that there should be procedures to allow people to take their own lives (using the term euthanasia) when they are suffering from or have been diagnosed with fatal diseases. A number of doctors have admitted prescribing extra sleeping tablets which have allowed these people to commit suicide, but in most countries, it is illegal to assist someone to commit suicide in spite of a major campaign to change the law by Jack Kevorkian in the United States and Philip Nitschke in Australia. It is possible for people to commit suicide with assistance in the Netherlands since 2002, and it was briefly possible in the Northern Territory, Australia, in 1996. SEE ALSO: Depression; Homicide. BIBLIOGRAPHY. B. Bongar, The Suicidal Patient: Clinical and Legal Standards of Care (APA, 2002); Kay Redfield
Sun Exposure
Jamison, Night Falls Fast: Understanding Suicide (Vintage Books, 2000); George Stone, Suicide and Attempted Suicide: Methods and Consequences (Carroll & Graf, 2001). Justin Corfield Geelong Grammar School, Australia
Sun Exposure The sun gives off visible light as well as ultraviolet light (UVA, UVB, and UVC), which gives energy to all living things on earth. The energy it provides our body is used to convert inactivated 7-dehydrocholesterol into activated Vitamin D by absorbing UVB on our skin. Vitamin D contributes to the maintenance of normal levels of calcium and phosphorus in the blood. Though the sun is a necessary component of life on earth and it helps in the production of Vitamin D in humans, sun exposure can be a negative aspect as well. Excessive exposure to the sun and its ultraviolet radiation can cause many different health problems. Some of these health problems are sunburns, damage to collagen fibers (contributing to premature aging of the skin), damage to eyes and surrounding tissue, damage to DNA, and even possibly causing skin cancer. With sunburn there is an acute period of excessive exposure to the sun, which is followed by redness, pain, and the exposed skin dying and peeling off. Sunburns can range from simple redness and tenderness to extreme sunburns, which can cause extreme pain that, requires hospitalization. The suns rays can cause damage to collagen fibers in human skin by breaking apart the connecting collagen fibers and causing premature aging of the skin leading to wrinkles (often called skin photodamage). Too much sun exposure to the eyes has been linked to certain diseases like pterygium (benign growth of the conjunctiva) and cataract development (opacity of the crystalline lens of the eye). Excess exposure of the retina to the suns rays can also cause vision damage and even blindness. Too much sun exposure can cause even worse damage to the human body at the molecular level. UVB light has been shown to have a direct cause on skin cancer in the human body. This type of radiation penetrates deep into skin cells causing DNA
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molecules to become excited and to form covalent bonds between adjacent tyamine bases, producing tymidine dimers. These changes in the normal DNA lead to mutations that can progress to cancerous growths. Skin cancer is one of the most common forms of cancer in America. There are about 1 million new cases of skin cancer diagnosed each year. The majority of these skin cancers are basal and squamous type, which are less dangerous than melanoma, which has about 53 thousand new cases per year. Men are more prone than women in America to develop skin cancer, where men are 14 percent more likely to develop skin cancer. The highest rate of skin cancer incidence in the world is in Australia. It is projected that one in three men and one in four women who live in Australia will be affected by skin cancer in their life. Skin cancer is the cause for 25 percent of the population’s deaths in Australia each year. With sun exposure being such a major cause of skin cancer in the world, it is important to use the resources we have to try and prevent new cases of skin cancer from ever happening. There are many different ways to protect yourself from the sun’s damaging radiation. Possibly the simplest way to protect yourself is by avoiding direct sunlight whenever possible. This is especially important during summer months when the sun’s rays are more powerful and can cause more damage. Avoid the sun by staying inside or in shaded areas. You can also protect yourself by wearing clothing that covers skin when outside. The darker the clothing, the more protection it will provide by absorbing the sun’s rays. It is often not practical to wear long pants and shirts outside during hot summer months, so it is also important to wear sunscreen lotion with an adequate Sun Protection Factor (SPF) rating. Sun exposure is an important part of life on earth, but with any good thing, too much of it can be bad. It is important to stay protected from too much of the sun’s radiation while maintaining the necessary amount of it to stay healthy. SEE ALSO: Skin Cancer; Skin Pigmentation Disorders. BIBLIOGRAPHY. Australian Institute of Health and Wel-
fare AIHW: for health and welfare statistics and information (Australian Institute of Health and Welfare, 2004);
1630 Sun Protection Factor (SPF) Cancer Facts and Figures (American Cancer Society, 2004); Y. Matsumura and H. N. Ananthaswamy, “Toxic Effects of Ultraviolet Radiation on the Skin,” Toxicology and Applied Pharmacology (v.195/33, 2004). Angela Garner, M.D. Ryan Strain University of Missouri–Kansas City
Sun Protection Factor (SPF) Sun protection factor (SPF) is a measure of how effectively a sunscreen prevents sun damage to human skin. The term, first coined in 1928, recognizes that SPF products are numerically graded according to the amount of irritation produced from ultraviolet radiation (UVR). SPF is a calculated ratio of the minimum amount of erythema produced with sunscreen versus the minimum amount produced with bare skin when exposed to UVR. The U.S. Food and Drug Administration recommends an SPF of 15 to reduce the chance of developing precancerous skin lesions. The greater the SPF number, the higher the UVR absorption; however, when comparing SPF values above 15, there is a less dramatic increase in UVR absorption. For instance, SPF 15 absorbs 93 percent of ultraviolet B (UVB) light while an SPF of 30 absorbs 97 percent, yet an SPF of 50 absorbs 98 percent. Most SPF values are specific for the measurement of UVB. Historically, sunscreens were labeled according to their ability to absorb or reflect UVB. Even so, these labels characterizing a sunscreen as a chemical or physical agent are becoming increasingly less used and out of date. The wide array of chemical agents used in the United States primarily absorb UVB; however, avobenzone (Parsol 1789) has strict UVA absorption. Paraaminobenzoic acid (PABA), a well-known chemical sunscreen, has been known to cause contact and photocontact dermatitis in 4 percent of users. Physical sunscreens are those agents previously characterized as sunblocks, which work to reflect and scatter UVB. These opaque emollients have fallen out of favor as they are typically heavy and produce an unattractive appearance. Innovative design to physical sunscreens containing zinc and ti-
tanium oxide has led to a micronized, small particle formula with an increased absorptive capability, thus dulling the parameters defining chemical and physical sunscreens. Ultraviolet A (UVA) light and UVB are most responsible for disease development. UVA is responsible for penetrating deep into skin layers, creating a suntan while UVB’s shorter wavelength penetrates less deeply, causing a sunburn. The damage from sunburn and suntan are irreversible and repeat exposure builds over a lifetime—skin changes seen in older individuals are a result of total lifelong sun exposure. A decreased incidence of squamous and basal cell skin lesions with regular sunscreen use is well documented, yet the incidence of melanoma with sunscreens is less understood. A liberal amount of a high SPF product should be applied daily prior to sun exposure. Sunscreen should be reapplied every two hours or sooner if activities include excessive sweating or swimming. Loose, dry garments containing a tight weave, dark color, and either denim or lycra af-
High SPF sunscreen should be reapplied every two hours or sooner if activities include excessive sweating or swimming.
Surgery
ford the greatest SPF protection. To obtain the quoted SPF, the quantity and how frequently the product is applied must be performed as recommended, but the best method of avoiding sun damage is to refrain from exposure between 10 a.m. and 3 p.m. SEE ALSO: Skin Cancer; Skin Pigmentation Disorders; Sun
Exposure; Ultraviolet Radiation.
BIBLIOGRAPHY. K. Wade Foster and Craig A. Elmets,
“Sunburn,” Conn’s Current Therapy (Saunders, 2006); Thomas P. Habif, “Light-Related Diseases and Disorders of Pigmentation,” Clinical Dermatology (Elsevier, 2004); Lee A. Kaplan, Exposure to Radiation from the Sun (Wilderness Medicine, 2001). Stephanie F. Ingram University of South Florida
Surgery Surgery is concerned with the diagnosis, treatment, and prevention of pathological conditions through operative procedures, while its counterpart, medicine, uses medications, behavioral modification, and a host of other nonsurgical means. The history of surgery entails the transition from primitive rituals based in spirituality to a highly innovative and specialized field driven by breakthroughs in science and technology, and the inventiveness of those who practice it. Modern surgery is performed by physicians known as surgeons, who undergo rigorous training, and usually specialize in the surgical management of a specific organ system or systems. A surgery is a complicated endeavor requiring pre-, intra-, and postoperative regimens, and a cohesive team of medical professionals with a wide array of skills. Surgery is currently at a pinnacle of technological innovation, and its future is limitless. The earliest archaeological evidence of surgery dates to the Neolithic era (around 10000 to 6000 bce) with a procedure known as trepanation. Trepanation was originally conducted to release spirits or evils from individuals suffering from headache, seizures, and other ailments by using a primitive instrument to cut a small hole in an afflicted person’s
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skull. Later civilizations used it for its benefits in relieving intracranial pressure. The Edwin Smith surgical papyrus, named after the American trader who bought the papyrus, is an ancient Egyptian trauma surgery textbook and the world’s oldest medical document. Written over 4,000 years ago, it gave a detailed account of the examination, diagnosis, and treatment of various injuries, and some of the first descriptions of neuroanatomy. Carvings also depicted procedures such as circumcision (the removal of the foreskin of the penis or the female clitoris), amputations (the removal of limbs), fracture repair, and lithotomy (the removal of bladder stones). Around 3,000 years ago on the banks of the river Ganges, the ancient Indian surgeon Sushruta authored the Sushruta Samhita describing over 300 procedures and 121 surgical instruments, some of which are strikingly similar to what is used today. He created the field of plastic surgery while healing those who had their noses cut off as punishment. The procedure involved carving a flap from the patient’s forehead and securing it over the missing portion of the nose. Ancient Greeks and Romans (1000 b.c.e. to 100 c.e.), including Hippocrates and Galen, furthered surgical knowledge through advances in anatomy and physiology, and with the development of novel instrumentation. During the Middle Ages (500 to 1400 c.e.), surgery suffered a regression. It was considered inferior to medicine and relegated to traveling surgeon-barbers. These men were identified by the striped white and red pole representing blood and bandages still in use today. They traveled from city to city cutting hair along with pulling teeth, amputating limbs, and tending wounds with high rates of infection and mortality. They were also purveyors of bloodletting, the act of draining blood, which was at the time thought to cure disease. In modern England, New Zealand, Australia, and South Africa, surgeons are distinguished from medical doctors by the title and badge of honor “Mr., Miss, or Mrs.” as opposed to “Dr.” as a vestige of the time of the barber-surgeon. With the publishing of Chirurgia Magna (“Great Surgery”) in 1316, the French surgeon Guy de Chauliac helped restore the integrity and scientific basis of surgery. In it, he detailed the repair of hernias (bulging of an organ through the tissue which contains it) and the treatment of fractures with slings and weights,
1632 Surgery among other procedures. In the 17th century, Ambroise Paré, often called the Father of Modern Surgery, greatly advanced the field with important breakthroughs. Notably, he developing ligatures to restrict blood flow as opposed to using cauterization (the use of heat to remove or close a body part). With the 18th century Age of Enlightenment and a wealth of scientific achievement in all fields, surgery was propelled into a new era. The use of ether, chloroform, and nitrous oxide as anesthesia in the mid-1800s allowed for complex procedures involving deeper organs in the abdomen, chest, and skull. The discovery of bacteria as the cause of fermentation, decay, and infection by Louis Pasteur along with Joseph Lister’s application of antiseptic technique using carbolic acid, greatly reduced postoperative infections. The advent of the X-ray in 1895 by Wilhelm Roentgen gave surgeons a powerful new tool and the discovery of blood groups allowed for transfusions. The prevalence of antibiotics and the use of analgesics further allowed surgeons to be more effective. Technological breakthroughs and great innovators have allowed surgery to evolve into its current phase where every organ is accessible and treatable. Conditions that were once irreparable are now routine. A surgeon usually masters the surgical management of a specific organ system or systems. Surgery is crudely broken down into fields of general surgery, pediatric surgery, cardiothoracic surgery, neurosurgery, gynecologic surgery, urologic surgery, ophthalmic surgery, orthopedic surgery, otolaryngology, plastic surgery, and vascular surgery. Training to become a surgeon begins with an undergraduate degree, followed by the achievement of a medical degree. Those who choose surgery enter a surgical residency program in a hospital setting. Over the next five to seven years, the skills and knowledge required to achieve proficiency in the surgical discipline are imparted from experienced surgeons and through other academic pursuits. The gamut of surgical specialties require varying levels of training and time commitments, with diverse knowledge and skill sets. Surgeons choose their specialty based on individual goals, personality characteristics, and personal preferences. Once they finish training and begin to practice, they have choice as to the kind of procedures they perform, the setting in which they desire to practice, and the surgical
techniques and technology they wish to employ. Surgical procedures are prioritized based on the scope and severity of a patient’s medical illness. Imminent life-threatening conditions including severe trauma by gunshot or car accident, ruptured blood vessel, or infected appendix are considered emergency procedures to be performed immediately. Urgent procedures, such as the excision of a malignant cancer, should be performed as soon as possible, but are not necessary for the immediate survival of the patient. Required procedures are necessary to rectify a pressing medical issue, for example, the removal of an overactive gland, but can be safely scheduled for a later date. Elective and optional procedures, such as a vasectomy or breast augmentation, are those that the patient wishes to be done for a medical or cosmetic benefit, but are not used to heal a medical ailment. stringent protocols An effective surgical procedure requires stringent pre-, intra-, and postoperative protocols to ensure the best outcomes. Prior to surgery, in order to protect the patients autonomy, the surgeon must obtain consent to perform the procedure, and discuss the desired outcomes and possible complications. Disease, medication, the surgery itself, and a gamut of other factors disrupt the biochemical homeostasis which allows the body to perform optimally. In order to promote good healing and recovery and to minimize complications, the patient should be as close to optimal as possible. Thus, the patient’s vital signs including temperature, pulse, blood pressure, and respiratory rate are routinely monitored. The essential constituents that help make up the human body, known as electrolytes, such as sodium and potassium, are checked and balanced, along with other components of the blood and urine. At the designated time of surgery, the surgical team gathers at the operating room. The room must be clean and contain the equipment for the procedure. A perimeter around the patient’s incision and all the surgical instruments must be kept germ free. This area is known as the operating, or sterile, field. During the operation, the surgical team is divided into two groups. The first group consists of the surgeon; assistants who could be more surgeons, residents, or medical students; and scrub nurses. The members of this team will be operating within the sterile field and must not bring
any germs into the field. Thus, they scrub their hands and arms with hot water, soap, and antiseptic solution, don sterile gloves and gowns, wear caps to cover their hair, and cover their mouths and noses with masks. The second team consists of the anesthesiologist or nurse anesthetist, other physicians, medical students or residents watching the procedure, any medical technicians, and circulating nurses. These individuals support the operating team by bringing medication, gathering equipment, and fulfilling any other tasks outside the sterile field. They also maintain the proper functioning of equipment such as operating microscopes, intraoperative imaging, or the heartlung bypass machine which artificially maintains the function of the heart and lungs in cardiac surgery. The surgery begins with the anesthesiologist administering medications that put the patient to sleep and render him or her insensitive to pain. The anesthesiologist is responsible for maintaining the individual in the anesthetized state by monitoring the patient’s vital signs and correcting any potential problems. The surgeon shaves the incision site, smothers it with antiseptic solution and isolates it by draping the rest of the body with sterile sheets. The incision is made and the surgery is performed. Surgical trauma inflicted is carefully monitored and corrected via transfusions, intravenous antibiotics, warming blankets, and so forth. If intraoperative complications arise or if mistakes are made, the surgeon must call upon experience, intuition, skill, and often luck to rectify the problem. As the surgery finishes, the circulating nurses make sure that all cloths and sponges used during the procedure are accounted for and were not left in the patient. Finally, the surgeon closes the wound using sutures, staples, or a number of other techniques. Postoperatively, the patient is taken to the surgical intensive care unit or postanesthetic recovery room where the patient is under constant surveillance to monitor vital signs and assess the success of the operation. Common complications, including lung complications, infection, or slowing of the blood from prolonged bed rest, are carefully monitored. Modern-day surgery is a testament to human ingenuity. A current paradigm involves minimizing surgical trauma by making incision sites smaller, and decreasing the amount of blood lost. This has led to laparoscopic procedures where a camera is placed through a small surgical incision to visualize a desired
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area, and instruments are placed through other small incisions to conduct the procedure. With this technique, surgeons can take a tissue biopsy for further evaluation, remove gallbladders and portions of lungs, and many other procedures. Robots, guided by a physician, perform operations with incredible precision, minimizing blood loss and trauma, and have the ability to move with dexterity not possessed by humans. With the aid of complex imaging including magnetic resonance imaging (MRI), computerized tomography (CT), and positron emission topography (PET), the interior of the body can be viewed as never before, allowing cancers, blood vessel disease, congenital defects, and other conditions to be detected without invasive procedures. Operating microscopes allow small spaces to be visualized and tiny blood vessels to be repaired. Using catheters, or tubes that can be inserted within the body, doctors and surgeons can monitor the body’s internal environment from the outside, introduce medications, place angioplasty balloons and stents to open blocked vessels, and even grab tiny clots in the brain with snares. Transplantation has become a reality with surgeons replacing diseased organs with healthy organs from a donor, including the eye lens, bones, bone marrow, heart, liver, lung, pancreas, kidney, skin, and even the face. As technology and the inventive human spirit progresses, surgery will continue to concurrently heal and amaze us. SEE ALSO: American College of Surgeons (ACS); Cryosurgery; Heart Bypass Surgery; Kidney Transplantation; Liver Transplantation; Oral Surgeon; Otolaryngology; Pancreas Transplantation; Urological Surgeon. BIBLIOGRAPHY. P. S. Chari, “Susruta and Our Heritage,” In-
dian Journal of Plastic Surgery (v.36, 2003); Robert A. Malt, The Practice of Surgery (Saunders, 1993); O. H. Wangensteen and S. D. Wangensteen, The Rise of Surgery. From Empiric Craft to Scientific Discipline (University of Minnesota Press, 1978); C. Wanjek, Bad Medicine: Misconceptions and Misuses Revealed, from Distance Healing to Vitamin O (Wiley, 2002); Robert Youngstown, Surgery Book: An Illustrated Guide to 73 of the Most Common Operations (St. Martin’s Press, 1993). Rishi Subbarayan Northeastern Ohio Universities College of Medicine
1634 Suriname
Suriname Suriname is the smallest independent nation in South America, a tiny green wedge of land surrounded by French Guyana, Guyana, and Brazil on the western coastline of the continent. A long-time colonial colony, the official language of Suriname is Dutch, and the majority religion is Hindu. Almost 40 percent of the population is of Hindustani or East Indian descent, with 31 percent Creole, and 15 percent Javanese. Most of the country is covered by dense rainforest, confining more than 70 percent of the population to a mere 0.4 percent of the total area. Population density is 526.5 people per square kilometer. The population is 439,000, growing at 0.2 percent annually. The economy is based on mining, primarily bauxite and gold. About 70 percent of Surinamers live in poverty. The net migration rate is minus 8.76, as people leave the country in search of better conditions. Life expectancy is 67 years for males and 71 years for females. Child mortality is 23 deaths per 1,000 for those under age 1, and 39 deaths per 1,000 for those aged 1 to 5. Maternal mortality is 110 deaths per 100,000 live births, and 85 percent of births are monitored by trained attendants. The fertility rate is 2.32 births per woman, with 42 percent using modern birth control methods. Sanitation varies throughout the country. For the majority living in the cities, 92 percent have improved water and 93 percent use improved sanitary facilities. For those living in the small indigenous communities in the interior rainforest, only 20 percent have clean water and only 30 percent have sanitation. Malaria is endemic in some regions, with 60 percent of all cases involving children under age 14. Salmonella cases have been on the increase in recent years, and shigella continues to be a problem in areas. Sexually-transmitted diseases have grown dramatically, with gonorrhea almost doubling and syphilis almost tripling in the 1990s. Accidents and violence are the leading causes of death for both children and adults under age 45. For those over 45, cardiovascular disease, cancer, and diabetes are the main causes of mortality. The human immunodeficiency virus (HIV)/AIDS prevalence rate among adults is quite low at 1.9 percent. About 5,100 Surinamers are believed to be infected. However small that figure seems, it is still the second leading cause of death for men and the third
leading cause of death for women. Monitoring of the epidemic is poor, with limited government resources available to develop surveillance programs. Tuberculosis (TB) rates have also risen, and those with HIV are now routinely tested for TB. The Ministry of Health monitors three public hospitals, 41 clinics, and 1 psychiatric hospital, with a combined staff of 191 doctors and 688 nurses. The Ministry also runs an epidemiological surveillance program for emerging health threats. More than 40 percent of the population receive free healthcare due to poverty. State-run programs receive assistance from various nongovernmental organizations. SEE ALSO: Healthcare, South America; Hygiene. BIBLIOGRAPHY. Pan American Health Organization, Health in the Americas, 2002 (Pan American Health Organization, 2002); World Health Organization, Mental Health Atlas 2005 (World Health Organization, 2006); World Health Organization, The World Health Report 2006: Working Together for Health (World Health Report) (World Health Organization, 2006); World Health Organization, The World Health Report 2000 - Health Systems: Improving Performance (World Health Organization, 2006).
Heather K. Michon Independent Scholar
Surveillance, Epidemiology and End Results Program (SEER) SEER, or Surveillance, Epidemiology, and End Results Program, is run by the National Cancer Institute (NCI) of the U.S. Department of Health and Human Services, to collect and study cancer incidence and survival data in the United States. SEER conducts their work based on population-based cancer registries including Atlanta, Connecticut, Detroit, Hawaii, Iowa, New Mexico, San Francisco-Oakland, SeattlePuget Sound, Utah, Los Angeles, San Jose-Monterey, Rural Geogia, Greater California, Kentucky, Louisiana, New Jersey, and the Alaska Native Tumor Registry. The selected population of states was specifi-
Swaziland
cally designed to be representative of the general U.S. population. The SEER program is an essential cornerstone, helping scientists, public health and medical professionals, legislators, advocates and policymakers understand the scope of cancer in this country. Currently, SEER is the only comprehensive source of population-wide data in the United States collecting information on patient demographics, stage of cancer at the time of diagnosis, course of treatment, and follow-up for patient survival data. Much about the longterm impact of cancer and treatment today has been learned from the SEER program since its inception in 1973. The key findings of SEER have been to describe the prevalence and incidence of cancer according to type, patient demographics, and treatment modalities. The SEER database is available to the public and contains survival data for one-quarter of the U.S. population. The breadth of cancer cases is impressive as well. More than 6 million in situ and invasive cancer cases are represented with over 350,000 cases added each year. SEER also builds upon its information by also reporting data from other sources related to cancer. SEER and the National Center for Health Statistics work together to provide mortality data. Furthermore, SEER partners with the U.S. Census Bureau to obtain population data used to calculate cancer statistics and rates each year. Other collaborations include the American Cancer Society, the Centers for Disease Control and Prevention, the International Association for Research on Cancer, the National Cancer Registrars Association, the North American Association of Central Cancer Registries, and the World Health Organization. SEER is also known as a model for cancer registry programs to strive for on the national and international level. SEER holds the key qualities registries aim for including comprehensive data collection across the country, rigorous analysis for data quality, public-use data files with analytic tools, information for cancer registrars at the local level, and numerous publications of statistics and implications. In order to uphold SEER’s commitment as the standard for data quality, the NCI has a standard delay of 22 months from end of a diagnosis year to the time the cancer reports are published. First reports of data are available in November and data are then made available the following spring. SEE ALSO: American Cancer Society (ACS); Cancer (Gen-
eral); Centers for Disease Control and Prevention (CDC);
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Department of Health and Human Services (DHHS); Prevalence; United States. BIBLIOGRAPHY. Leon Gordis, Epidemiology (Saunders,
2004); National Cancer Institute, Surveillance Epidemiology and End Results, http://seer.cancer.gov/ (cited October 2006); David Schottenfeld and Joseph F. Fraumeni, Cancer Epidemiology and Prevention (Oxford University Press, 2006). Jonathan Tan, M.P.H. SUNY Stony Brook School of Medicine
Swaziland Swaziland is a landlocked country in southeastern Africa, between South Africa and Mozambique. The kingdom won independence from Britain in 1968. There is some wealth in Swaziland, but it is usually held by foreigners and does not do much to benefit the people. Most of the population gets by on subsistence agriculture, with 70 percent of Swazis living below the poverty line. Swaziland now has the world’s highest rate of HIV/AIDS infections, with an average life expectancy of less than 33 years. The population is estimated at 1,133,000 and it’s growth rate is actually in deficit at -0.337 percent annually. The birth rate is 26.98 per 1,000 but the death rate is higher, at 30.35 deaths per 1,000. Median age is 18.6. Life expectancy is just 31.84 years for males and 32.62 years for females. Gross national income is $2,280 per capita, with 8 percent living on less than $1 a day and 69 percent living in poverty. Persistent drought has reduced crop yields in recent years, and a quarter of the population required food aid in 2004–05. AIDS and tuberculosis have spread throughout the population of Swaziland since the first AIDS cases was diagnosed in 1986. In 1999, King Mswati III declared it a national disaster. The adult prevalence rate for HIV/AIDS is 39 percent, or over 220,000 people. There have been some 17,000 AIDS-related deaths. The tuberculosis prevalence rate is even worse, at 1,089 cases per 100,000 and 289 deaths per 100,000. Pulmonary TB is the leading cause of death in Swaziland, with AIDS the
1636 Sweden third leading cause. The government is trying to provide both preventative and palliative services to the people, but with so many sick and dying, it is difficult to mount effective campaigns. Swazis do have other heath problems, including a high rate of acute respiratory infections, diarrhea, malaria and schistosomiasis. Non-communicable diseases like hypertension and diabetes are a growing problem. The Ministry of Health has noted an increased rate of depression, schizophrenia, and epilepsy in recent years. With an urban population growing at 7.5 percent annually, traffic accidents and other injuries are becoming common. Women and children’s health is threatened from any number of directions. More than half of AIDS cases are women, with an estimated 120,000 infected. In 1992, about 4 percent of pregnant women were infected. Today, 39 percent of pregnant women have the virus. About 63,000 children have already been orphaned by AIDS. Child mortality is high, with 160 deaths per 1,000 in those aged 1 to 5 years. Malaria is a leading cause. Maternal mortality is also high, at 340 deaths per 100,000 live births. Swaziland’s medical system includes 153 clinics, nine health centers and six hospitals, with up to 90 percent of hospital beds located within the cities. There are 171 physicians and 4,590 nurses working in the country. Due to the lack of services, many Swazis rely on traditional healers. Annual expenditures on health absorb 7-9 percent of the government’s revenues, and the kingdom is trying to find ways to make heath care more affordable for all. SEE ALSO: Healthcare, Africa; Women’s Health. Bibliography. Central Intelligence Agency, “Swazi-
land,” CIA World Factbook. www.cia.gov/library/publications/the-world-factbook/geos/wz.html (cited June 2007); The Joint United Nations Programme on HIV/ AIDS, “Swaziland,” www.unaids.org/en/Regions_Countries/Countries/swaziland.asp (cited June 2007); Kingdom of Swaziland, “Ministry of Health and Welfare,” www.gov. sz/home.asp?pid=182 (cited June 2007); ; “Swaziland”. Researchafrica.rti.org. www.researchafrica.rti.org/index. cfm?fuseaction=home.country_view&country_id=25 (cited June 2007); United Nations Children’s Fund, “UNICEF—Swaziland—Statistics”. UNICEF. www.unicef.org/ infobycountry/swaziland_statistics.html#28 (cited June
2007); World Health Organization, “A Guide to Statistical Information at WHO,” www.who.int/whosis/en/index. html (cited June 2007). Heather K. Michon Independent Scholar
Sweden With a per capita income of $29,800, Sweden is the 27th richest nation in the world. After rebounding from a global downturn in 2000–2002, the economy is growing at a rate of 2.7 percent. Inflation is well under control at 0.5 percent, and unemployment currently stands at 5.8 percent. Income is fairly well distributed in Sweden, and the country ranks 25 on the Gini Index of Inequality. The richest 10 percent of the people hold 20.1 percent of resources, and the poorest 10 percent claim 3.7 percent. Sweden has an extensive welfare system that provides healthcare services to the entire population. The United Nations Development Programme (UNDP) Human Development Reports rank Sweden fifth in the world n overall quality-of-life issues. The Swedish government spends 3 percent of the total budget on health. Of the total Gross Domestic Product (GDP), 9.4 percent is earmarked for healthrelated programs, and the government allots $2,704 (international dollars) per capita to health. More than 85 percent of total health spending is covered by the government. The private sector supplies 14.8 percent of health funding, and 92.10 percent of that amount is derived from out-of-pocket expenses. There are 3.28 physicians, 10.24 nurses, 0.70 midwives, 0.82 dentists, and 0.66 pharmacists per 1,000 population in Sweden. In 1999, Sweden instituted a new social insurance program that mandates private retirement accounts to furnish coverage for the elderly, the disabled, and survivors. Workers pay 7 percent of assessable income into these accounts, and the self-employed contribute 10.21 percent of assessable earnings. Employers contribute 10.21 percent of payroll, and the government subsidizes those who are not covered through other programs. All residents receive medical benefits, and cash benefits are paid to the seriously ill and new par-
ents. All residents with one or more children are eligible for family allowances. The National Health System, financed by taxes, is compulsory, and the number of Swedes opting for voluntary insurance is minimal. Direct healthcare services are provided at the regional level through healthcare districts composed of a hospital and several primary healthcare units. Swedish cities have been given the responsibility for providing social welfare services that include school health services, nursing home care, and in-home care. Sweden has the seventh highest life expectancy in the world (80.51 years), and women generally outlive men by around five years. Literacy is virtually universal at 99 percent, and all of the relevant populations attend primary and secondary schools. The entire population has sustained access to safe drinking water and improved sanitation. Around 78 percent of women in the relevant age group use some method of birth control, and Swedish women give birth at a rate of 1.66 children each. All births are attended by trained personnel, and the adjusted maternal mortality ratio of two deaths per 100,000 live births is one of the lowest in the world. Between 1990 and 2004, infant mortality was halved, dropping from six to three deaths per 1,000 live births. During that same period, the mortality rate of children under the age of 6 fell from seven to four deaths per 1,000 live births. Currently, Sweden’s infant mortality rate is the second lowest in the world (2.76 deaths per 1,000 live births). Despite the overall good health of the Swedish population, 4 percent of infants are underweight at birth. In general, infant immunization rates are high: 99 percent of infants receive diphtheria, pertussis, and tetanus (DPT1 and DPT3) and polio vaccinations; 98 percent receive Haemophilus influenzae type B; and 94 percent receive measles vaccinations. Immunization rates for other diseases are significantly lower. Only 16 percent of Swedish infants are immunized against tuberculosis, and 1 percent is immunized against hepatitis B. The HIV/AIDS adult prevalence rate in Sweden is 0.1 percent. Although 3,600 people are living with the disease, fewer than 100 have died because of advanced treatment options and new drug therapies. In spring 2003, Sweden experienced an outbreak of severe acute respiratory syndrome (SARS), and human influenza A/H 3N2 generated concern in winter 2004. The government has also expressed concern about
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increased incidences of sleep disorders and a rise in mental health problems. An increase in the number of females experiencing alcohol-related conditions is also claiming the attention of health and government officials. While numbers of Swedes claiming sick leave has doubled since 1997, the increase is partially attributable to a generous sick-leave policy. In Sweden, 83 percent of all deaths are a result of noncommunicable diseases. The leading causes of death are cardiovascular disease (41 percent), cancer (26 percent), and external causes (7 percent). In 2000, the Swedish government published the National Plan of Action for Developing Healthcare, emphasizing preventive care. The following year, the Swedish National Agency for Education was given the responsibility for educating the nation’s children about the benefits of good health. SEE ALSO: Healthcare, Europe; Insurance. BIBLIOGRAPHY. Central Intelligence Agency, “Sweden,”
World Factbook, www.cia.gov/cia/publications/factbook/ geos/sw.html (cited April 2007); Commission on the Status of Women, “Sweden,” www.un.org/womenwatch/daw/Review/responses/SWEDEN-English.pdf (cited April 2007); Spencer Di Scala, Twentieth Century Europe: Politics, Society, Culture (McGraw-Hill, 2004); Sandra Halperin, War and Social Change in Modern Europe: The Great Transformation Revisited (Cambridge University Press, 2004); Martin A. Levin and Martin Shapiro, eds., Transatlantic Policymaking in an Age of Austerity: Diversity and Drift (Georgetown University Press, 2004); Jeremy Rifkin, The European Dream: How Europe’s Vision of the Future Is Quietly Eclipsing the American Dream (Jeremy P. Tarcher/ Penguin, 2004); Social Security Administration, “Sweden,” www.ssa.gov/policy/docs/progdesc/ssptw/2002-2003/ europe/sweden.html (cited April 2007); United Nations Children’s Fund, “Sweden,” www.unicef.org/infobycountry/sweden_statistics.html (cited April 2007); World Bank, “Sweden Data Profile,” http://devdata.worldbank.org/external/CPProfile.asp?PTYPE=CP&CCODE=SWE (cited April 2007); World Health Organization, “Highlights on Health in Sweden,” www.who.dk/document/chh/swe_highlights. pdf (cited April 2007); World Health Organization, “Sweden,” www.who.int/countries/swe/en/ (cited April 2007). Elizabeth R. Purdy, Ph.D. Independent Scholar
1638 Switzerland
Switzerland The Swiss Confederation is one of the most prosperous and stable economies in Europe. The per capita income of $32,200 makes Switzerland the 18th richest nation in the world. Much of that wealth is generated by investors who are attracted by the secrecy of Switzerland’s banking laws. The economy is currently growing at a rate of 1.9 percent, and inflation is low (1.2 percent). The unemployment rate (3.8 percent) is less than half the average for Europe. Some income disparity does exist, and Switzerland ranks 33.1 on the Gini Index of Inequality. The richest 10 percent claim 25.2 percent of the country’s wealth, while the poorest 10 percent claim 2.6 of resources. The United Nations Development Programme (UNDP) Human Development Reports rank Switzerland ninth in the world in overall quality-of-life issues. The Swiss government expends 11.5 percent of the Gross Domestic Product (GDP) on health, allocating $3,776 (international dollars) per capita for health-related programs. The government bears the responsibility for 58.5 percent of total health spending, and 69.3 percent is earmarked for Social Security. Private sector spending accounts for 41.5 percent of health spending in Switzerland, and more than three-fourths of that amount are generated from out-of-pocket expenses. There are 3.61 physicians, 10.75 nurses, 0.28 midwives, 0.50 dentists, and 0.60 pharmacists per 1,000 population in Switzerland. While the central government bears the brunt of providing health insurance to protect the population from illnesses, accidents, and disability, each canton has its own health laws. These local governmental bodies also provide oversight of health services. Switzerland provides a solidarity-based minimum retirement benefit and guarantees equal access to healthcare. Social programs designed to promote the interests of children and adolescents include free education and training opportunities. Compulsory social insurance protects individuals who are ill or who experience work-related accidents or who go through extended periods of unemployment. The elderly are covered by a generous pension plan. All employed residents of Switzerland are eligible for the basic pension plan, and many residents choose to take out voluntary insurance coverage. In order to protect the elderly and the disabled, workers pay 4.2
percent of their salaries into the fund. Seven percent of earnings are earmarked for disability pensions. The self-employed contribute 7.8 percent of income to the fund for the elderly and survivors and 1.4 percent for disability coverage. Employers are required to contribute 4.2 percent of the payroll to retirement and survivor fund and 0.7 percent to the disability fund. Government funds from varying levels account for one-fifth of retirement allotments and half of disability costs. Maternity benefits are provided for 16 weeks. Switzerland has the eighth highest life expectancy in the world, with the population of 7,523,934 enjoying a life expectancy of 80.51 years. On average, females outlive males by six years. At 99 percent, literacy is virtually universal, and nearly all of the relevant population attends primary and secondary school. All of the people have sustained access to safe drinking water and improved sanitation. Some 82 percent of Swiss women use birth control, and females give birth at a rate of 1.43 children each. The adjusted maternal mortality ratio is seven deaths per 100,000 live births. With the 13th lowest infant mortality rate among nations in the world, infant mortality in Switzerland occurs at a rate of 4.34 deaths per 1,000 live births. Between 1990 and 2004, infant mortality fell from seven to five 5 deaths per 1,000 live births, and under5 mortality dropped from nine to five deaths per 1,000 live births. Six percent of all children are underweight at birth despite general good health. In general, immunization rates are high: 98 percent of infants are immunized against diphtheria, pertussis, and tetanus (DPT1); 95 percent against DPT3 and polio; 91 percent against Haemophilus influenzae type B (Hib3); and 82 percent against measles. The health of the Swiss population is threatened by air pollution caused by vehicle emissions and openair burning, and water sources have been polluted by the runoff from agricultural activities. The current HIV/AIDS adult prevalence rate is 0.4 percent. Some 13,000 people are living with this disease, but new drugs and increased treatment options have limited the number of HIV/AIDS-related deaths to less than 100. Switzerland was one of several countries to experience outbreaks of severe acute respiratory syndrome (SARS) in spring 2003, and human influenza surfaced in winter 2003 and 2004. The leading causes of death are cardiovascular disease, cancer, and death from external causes. The rise in lung cancer among
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rope/switzerland.html (cited June 2007); Social Watch, “Switzerland,” www.socialwatch.org/en/fichasPais/38.html (cited June 2007); United Nations Children’s Fund, “Switzerland,” www.unicef.org/infobycountry/switzerland_statistics.html (cited June 2007); World Bank, “Switzerland Data Profile,” http://devdata.worldbank.org/external/CPProfile. asp?PTYPE=CP&CCODE=CHE (cited June 2007); World Health Organization, “Highlights on Health in Switzerland,” www.euro.who.int/document/e73485.pdf (cited June 2007); World Health Organization, “Switzerland,” www.who.int/ countries/che/en/ (cited June 2007). Elizabeth R. Purdy, Ph.D. Independent Scholar
Syria
Switzerland has the eighth highest life expectancy in the world, with the population of 7,523,934 enjoying a life expectancy of 80.51 years.
Swiss women is causing great concern. Violence is a problem among both men and women, and Switzerland has one of the highest suicide rates in Europe. SEE ALSO: Healthcare, Europe. BIBLIOGRAPHY. Central Intelligence Agency, “Switzerland,”
World Factbook, www.cia.gov/cia/publications/factbook/ geos/sz.html (cited June 2007); Commission on the Status of Women, “Switzerland,” www.un.org/womenwatch/daw/Review/responses/SWITZERLAND-English.pdf (cited June 2007); Spencer Di Scala, Twentieth Century Europe: Politics, Society, Culture (McGraw-Hill, 2004); Sandra Halperin, War and Social Change in Modern Europe: The Great Transformation Revisited (Cambridge University Press, 2004); Martin A. Levin and Martin Shapiro, eds., Transatlantic Policymaking in an Age of Austerity: Diversity and Drift (Georgetown University Press, 2004); Jeremy Rifkin, The European Dream: How Europe’s Vision of the Future Is Quietly Eclipsing the American Dream (Jeremy P. Tarcher/Penguin, 2004); Social Security Administration, “Switzerland,” www.ssa.gov/policy/docs/progdesc/ssptw/2004-2005/eu-
Syria is located on the eastern Mediterranean and borders Turkey, Iraq, Lebanon, Jordan, and Israel. The population of the country is nearly 19 million. Healthcare in Syria falls under the direction of the Ministry of Health. While many health indicators show evidence of excellent healthcare including life expectancy and infant and maternal mortality, certain areas could use improvement including system factors including health insurance, quality assurance and credentialing of healthcare providers. Improvements in health can be attributed to vaccination, improved living standards, increasing literacy and access to information and improvements made to assure water quality and access to improved sanitation systems. Hospitals in the larger cities provide good medical care to both Syrian citizens and foreign travelers, while care outside of the cities may not be as readily accessible. Other important factors are the widespread coverage of primary healthcare services, therapeutic services and availability of emergency and relief system, plus the increased number of health workers. By cooperation and support from a variety of international experts on healthcare, including the European Commission and the World Health Organization (WHO), Syria has developed a national strategy document for healthcare reform. The President of the Republic approved the plan and issued a law in 2006 to make the plan binding on all executive branches
1640 Syria of government. The plan includes building additional hospitals, improve data management including resources and information availability. For travelers to Syria, care should be exercised to prevent certain infectious diseases. Malaria from the bite of an infected mosquito causes symptoms of fever, chills, sweats, headache, body aches, nausea and vomiting, fatigue occurring at least seven to nine days after being bitten. Malaria infections with Plasmodium falciparum, if not promptly treated, may cause kidney failure, coma, and death. Malaria may cause anemia and jaundice. Medications are available to prevent infection. In addition to malaria, disease risks in rural areas include leishmaniasis (caused by protozoa transmitted by sand fly bites—symptoms include skin sores and swollen glands near site of bite) and West Nile Virus (from mosquito bites). Protecting against insect bites will help to prevent these diseases. Measles continues to be reported and in Yemen in 2005 Polio was reported.
Schistosomiasis is a parasitic infection found in fresh water in Syria, Saudi Arabia and Yemen. To avoid infection, travelers should not wade, swim or bathe in fresh or untreated water. Bird flu (the pathogenic H5N1) has been found in poultry populations in the Middle East. To protect against infection, travelers should avoid contact with wild and domestic birds. see also: Malaria, World Health Organization BIBLIOGRAPHY. World Health Organization, “Arab Re-
public of Syria Briefing Note,” http://www.who.int/healthmetrics/library/countries/syr/en/index.html (cited August 2007); “Health Information for Travelers to Syria”, www. cdc.gov; “Preparing for Your Trip to Syria” at wwwn.cdc. gov/travel/destinationSyria.aspx (cited August 2007). Lyn Michaud Independent Scholar
T Taiwan With a per capita income of $27,500, Taiwan (formerly Formosa) is ranked as the 34th richest nation in the world, far outreaching the much larger and more diverse China ($6,000, ranking 118th). Nine percent of the Taiwanese population live in poverty, and 4.1 percent are unemployed. The constitution guarantees health protection, and the government has established a comprehensive national healthcare system (NHI) that took root from the Chinese social programs of the 17th century in which the government provided aid to the poor, women, and children. When the Japanese annexed Formosa in 1895 at the end of the first Sino-Japanese War, social programs were considerably expanded and poverty was abolished. At the end of World War II, the island was returned to China, and most existing social programs were dismantled. Taiwan was established in response to a Communist victory on mainland China in 1949. Since that time, Taiwan’s status as has remained uncertain because China has not dropped its claim to the island, and future reconciliation with the mother country is considered possible. Taiwan’s international status has been particularly unsettled since it was forced to concede its seat in the United Nations (UN) to the People’s Republic of China in 1971, and efforts to gain a
UN seat in its own right have been unsuccessful. China reaffirmed its ownership of Taiwan in 2005, passing an antisecession law. As a result of Taiwan’s ambiguous status on the international scene, statistics on common health indicators are not always available. By the 1960s, with help from the United States and the UN, Taiwan had launched a new welfare program, and government spending on health programs increased dramatically. Two decades later, new and more comprehensive social welfare policies were introduced. At that time, the government passed the Aged Welfare Law, the Handicapped Welfare Law, and the Social Assistance Law. A national health insurance (NHI) program was announced in 1987. Taking effect in 1995, an additional 7.5 million Taiwanese, chiefly the uninsured, the elderly, children, students, and full-time homemakers, were covered under the new policy. NHI subsidies are based on occupation rather than on income. Efforts to improve healthcare in Taiwan led to an increase in the number of healthcare professionals per 10,000/population from 11.37 in 1961 to 57.53 in 1996. Within a year, the government was spending 5.48 of the Gross Domestic Product (GDP) on healthcare. After taking effect, NHI ran into immediate controversy because of its exorbitant costs. A compromise was reached that required employers to finance
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1642 Tajikistan 60 percent of the cost. Employees contributed an additional 30 percent, while the government was responsible for only 10 percent. All individuals over the age of 70 were exempted from paying premiums. National insurance subsidizes 70 to 95 percent of all hospital costs for those covered by the program. Almost 92 percent of Taiwanese are literate. The population of 23,036,087 experiences a life expectancy of 77.43 years, with females outliving males an average of five years. Infant mortality is relatively low at 6.29 deaths per 1,000 live births, and Taiwan has the 42nd lowest ranking in the world. The fertility rate is also relatively low at 1.57 children per female. The health of the Taiwanese is vulnerable to the environment, and Taiwan experiences both earthquakes and typhoons. Industrial emissions have led to extensive air and water pollution, and raw sewage has contaminated drinking and fishing waters. Low-level radiation waste disposal also poses health threats. SEE ALSO: Healthcare, Asia and Oceania. BIBLIOGRAPHY. Central Intelligence Agency, “Singapore,”
World Factbook, www.cia.gov/cia/publications/factbook/ geos/tw.html (cited June 2007); Peter C.Y. Chow, “Social Expenditures in Taiwan (China),” http://siteresources.worldbank.org/WBI/Resources/wbi37167.pdf (cited June 2007); John F. Copper, Taiwan: Nation, State or Province? (Westview, 2003); Katherine McFate, et al., Poverty, Inequality, and the Future of Social Policy: Western States in the New World Order (Russell Sage, 1995); Carlos Gerardo Molina and Jose Nunez del Arco, eds., Health Services in Latin America and Asia (Johns Hopkins University Press, 2001). Elizabeth R. Purdy, Ph.D. Independent Scholar
Tajikistan Tajikistan is a landlocked country in Central Asia, bounded on the south by Afghanistan, on the north and northwest by Kyrgyzstan and Uzbekistan, and on the east by China. It is the smallest Central Asian country, at 143,100 kilometers (55,250 miles) and one of the most mountainous, with almost 50 percent of the country laying about 3,000 m (over 9,800 feet).
Tajikistan joined the Soviet Union in 1929 and gained independence in 1991. Civil war broke out soon after. Peace was not declared until 1997. Tajikistan is home to 7 million people and is growing at 1.895 percent annually. The birth rate is 27.33 per 1,000 population and the death rate is 7.05 per 1,000. Like most of the former Soviet states, it is losing citizens to migration, with 1.33 people leaving per 1,000. Median age is 21.3, with 50 percent of the population under 18 years of age. Life expectancy is 61.6 years for males and 67.78 years for females. Gross national income is the lowest in Europe, at $330 per person. Seven percent live on less than $1 a day, and 64 percent live in poverty. The average rate of inflation is 121 percent. Three-fourths of the population lives outside the cities, making it Europe’s least urbanized country, and 67 percent of the population works in agriculture. There is little epidemiological surveillance of communicable disease. Only half the population has clean water or sanitary waste disposal. This leads to a high burden of diseases such as viral hepatitis, typhoid, cholera, malaria, and other gastrointestinal ailments. These illnesses cause a fair amount of misery, but account for only 4 percent of mortality. Tuberculosis is on the rise, climbing from 55 cases per 100,000 in 2001 to 67 cases per 100,000 in 2003; there is little money for widespread vaccination. Like its Central Asian neighbors, the AIDS rate is low at 0.1 percent, or around 4,900 cases. It has not moved into the general population, and seems to be confined to IV drug users, prisoners, and sex workers. The government has made a good start at containing and preventing the spread of the virus, including the opening of testing and counseling centers among at-risk areas. Drug use has increased as Afghanistan’s poppy production has returned to pre-war levels; Tajikistan is on the main smuggling routes out of Afghanistan. Non-communicable disease accounts for at least 85 percent of mortality in Tajikistan. (Inaccurate medical coding of diseases skew the figures to some degree.) Cardiovascular disease (CVD) is the main killer, accounting for 57 percent of all deaths within the country. Tajikistanis main risk factors for the development of CDV are alcohol abuse, high blood pressure, and obesity for males. For females, high blood pressure, obesity, and exposure to indoor smoke from cooking with solid fuels are the main risks. Tajikistan seems to
Tanner Stages
have a low rate of cancer, but like its neighbors, heavy alcohol use and viral hepatitis increases the mortality from cirrhosis and chronic liver disease. Despite attempts to improve care for children, Tajikistan has infant and child mortality rates more in line with Africa than Europe. Ninety-one of every 1,000 infants die before the age of one, and 118 of every 1,000 dying before the age of five. UNICEF believes that this generation of children will be less educated than their parents, as the universal education of the Soviet period has collapsed. About 18 percent of children work to help support their families. Eighty percent of the 11,000 children in Tajikistani orphanages are not orphans at all, but have been put into care by parents who cannot afford to keep them or who have migrated in a search for work. Tajikistani society has become more “traditional” since the fall of the Soviet Union, leaving women with less access to education and fewer rights. Girls marry early, and the fertility rate is 3.09 children per women. Only 34 percent use contraception. Many women suffer from anemia and goiter, putting their health at risk during their childbearing years. The statistics are unclear, as many women give birth at home and 25 percent of births go unregistered, but the maternal mortality is 100 deaths per 100,000 live births. Like other former Soviet states, Tajikistan is attempting to reorganize its medical system to make it more efficient. The Soviet system emphasized the number of staff and beds over quality of care, leaving newly independent states a surplus of both. By 2000, 30 percent of hospitals had been closed. The number of student accepted into medical programs had been reduced as well. Unfortunately, medical reform has not been a high priority for the government, which is still trying to recover from years of civil war. SEE ALSO: Healthcare, Asia and Oceania; Hygiene. Bibliography. Central Intelligence Agency, “Tajikistan,”
CIA World Factbook. www.cia.gov/library/publications/ the-world-factbook/geos/ti.html (cited July 2007); IRIN: Humanitarian News and Analysis, “TAJIKISTAN: Urgent Need for TB Campaign—Health Ministry.” www.irinnews. org/report.aspx?reportid=26006 (cited July 2007); The Joint United Nations Programme on HIV/AIDS, “Tajikistan,” www. unaids.org/en/Regions_Countries/Countries/tajikistan.
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asp (cited July 2007); United Nations Children’s Fund, “Tajikistan—Statistics”. www.unicef.org/infobycountry/ Tajikistan_statistics.html#29 (cited July 2007); United Nations Children’s Fund, “UNICEF Tajikistan,” www.unicef. org/tajikistan/index.html (cited July 2007) World Health Organization, “A guide to statistical information”.ww.who. int/whosis/en/index.html (cited July 2007); World Health Organization, “Health Care in Transition: Tajikistan,” www.euro.who.int/document/e69820.pdf (cited July 2007); World Health Organization, “Highlights on Health: Tajikistan,” www.euro.who.int/document/e88393.pdf (cited July 2007). Heather K. Michon Independent Scholar
Tanner Stages The Tanner Stages, also known as the Tanner Scale, are a method of describing the physical development of human beings from their time as children through adolescence and to adulthood. This is based on an examination of external primary and secondary sex characteristics, and is important to measure puberty and other developments, as well as work out what form of medication to prescribe for some treatments such as for human immunodeficiency virus (HIV), as puberty may occur at different ages in different people. The concept of the Tanner Stages was developed by James Mourilyan Tanner who was born near London, United Kingdom, and studied at Queen Mary’s Hospital, University of London, the Medical School at the University of Pennsylvania, and at the Medical School at Johns Hopkins University, becoming a Reader in Growth and Development at the Institute of Child Health at the University of London, a position he held from 1956, and was the author of a large number of scholarly papers, and also two books, on the field. There are five stages in the Tanner Scale, with the first having both males and females having no pubic hair, males having a small testicular volume, and females having no glandular tissue, with the areola following the skin contours of the chest. In Stage II, males and females have a small amount of long downy hair, with males having a testicular volume between 1.6 milliliter and 6 milliliter, and females having breast
1644 Tanzania buds forming with a small area of surrounding glandular tissue and the areola starting to widen. In Stage III, the pubic hair becomes coarse and curly, and begins to extend laterally, with males having a testicular volume of between 6 and 12 milliliter and a larger scrotum than before, and females having more elevated breasts that extend beyond the borders of the areola. Stage IV has significant pubic hair for males and females, testicular volume between 12 and 20 milliliter, with a larger and darker scrotum, and enlarged penile dimensions, and females having much larger and more elevated breasts, and the areola and papilla forming a secondary mound which projects out from the contour of the breasts. Stage V is full adulthood with pubic hair spreading across the thighs, males having a testicular volume greater than 20 milliliter, and females having full adult-size breasts. SEE ALSO: Adolescent Development; American Academy
of Pediatrics (AAP); Child Development; Infant and Toddler Development. BIBLIOGRAPHY. James M. Tanner, Education and Physi-
cal Growth (University of London Press, 1961); James M. Tanner, Growth at Adolescence (Blackwell Science Publications, 1962). Justin Corfield Geelong Grammar School, Australia
Tanzania This East African country was occupied by the Germans from 1886, becoming German East Africa, or Tanganyika, with the British occupying the offshore island of Zanzibar from 1890. During World War I, the Allies fought the Germans and at the end of the war, Tanganyika was administered by the British. It gained its independence in December 9, 1961 as the Republic of Tanganyika. In 1964 it merged with Zanzibar to form the Republic of Tanzania. The country has a population of 38,329,000 (2005), with 4.1 doctors and 85 nurses per 100,000 people. The medical services in Tanganyika trace their origins to 1888 when Adrien Atiman, a West African, visited the area. A former slave, he had studied medi-
cine in Malta, and started practicing in Tanganyika. However during the period of colonial rule by the Germans, the health services in Tanganyika remained extremely limited, with most hospital patients being either Europeans, wealthy Asians or the local elite. In Zanzibar, Arab physicians still used the works of the Arab surgeon Avicenna (980-1037), although the British did build a hospital there. During British colonial rule in Tanganyika, several hospitals were established in Dar es Salaam, but these did not cater for most of the local peoples. Indeed the European Hospital in Dar es Salaam had 22 beds for a European population of 158, while the Sewa Haji Hospital had 75 beds for a population of 18,300. In 1949 the National Institute for Medical Research was established in Tanganyika. It still operates from Dar es Salaam and is the official medical research center for the country. After independence, many hospitals were opened. By the late 1960s there were district hospitals throughout the country. By the 1980s there were also many private hospitals and well-equipped mission hospitals. Even in spite of this improved healthcare, many Tanzanians use faith healers and herbal cures. Many of the health problems in Tanganyika and Zanzibar during the colonial period were similar to those in many other parts of the world where poor hygiene and sanitation led to an increased prevalence of cholera, typhoid and tuberculosis. Hansen’s disease, often known in Africa as leprosy, was also common with as many as 150,000 people suffering from it as late as the 1970s. There have also been problems with rabies, and a large increase in recent years of people suffering from HIV/AIDS. There has also been a rise in cancer rates, especially liver cancer for men, and also Kaposi’s sarcoma, which has been associated with a rise in the number of HIV cases in the country. During the 1990s there have also been droughts, leading to malnutrition, especially of children, in many parts of the country. SEE ALSO: AIDS; Cholera; Liver Cancer; Typhoid; Tuber-
culosis.
BIBLIOGRAPHY. Knud Balslev, A History of Leprosy in Tan-
zania (African Medical and Research Foundation, 1989); Ann Beck, A History of the British Medical Administration of East Africa 1900-1950 (Harvard University Press, 1970);
Taste and Smell Disorders
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Ann Beck, Medicine, Tradition and Development in Kenya and Tanzania 1920-1970 (Crossroads Press, 1981); David F. Clyde, History of the Medical Services of Tanganyika (Government Press, Dar es Salaam, 1962); D.E. Ferguson, “The Political Economy of Health and Medicine in Colonial Tanganyika,” in M.H.Y. Kaniki (ed.), Tanzania Under Colonial Rule (Longman Group Limited, 1980). Justin Corfield Geelong Grammar School, Australia
Taste and Smell Disorders The pathophysiology of the special senses of taste and smell are not as well understood as those of the more basic senses of sight and hearing. Nevertheless, recent research into the topic has delivered an important insight: the sense of taste (gustatory sense) is strongly related to sense of smell (olfactory sense). Smell and taste disorders are a recognized clinical entity and it is estimated that 200,000 patients visit a physician annually for treatment of smell and/or taste dysfunction. Mechanics of Taste and Smell Taste cells (buds) located on the tongue and soft palate release chemosensory molecules that transmit messages to higher neural centers where specific taste identification is conducted. It is thought that humans can generally discern taste sensations of sweet, salty, sour, and bitter. As Anholt explains, “the sense of smell depends on olfactory chemoreceptors high in the nasal cavity along the upper septum and cribiform plate which underlies the anterior cranial fossa.” Odorant molecules that pass into the nose dissolve into the nasal mucosa and activate these olfactory chemoreceptors to trigger a sense of smell. Barker identifies, “There is also a chemosensory sense mediated by the trigeminal nerve (fifth cranial nerve), which is triggered by pungent and irritant compounds, such as hot peppers, horseradish, and so on, and perceived as burning or irritating. This pathway is independent from the other modalities of taste and smell.” Disorders A reduced ability to taste or discriminate between various tastes is called hypoguesia. In people who
Issues regarding quality of life may develop as patients may be unable to enjoy the taste or smell of their once-favorite foods.
can detect no tastes, the condition is called aguesia. People who have a decreased ability to detect odor are said to have hyposmia. Those who cannot detect odor at all have anosmia. According to the National Institutes of Health, “true taste loss is rare; perceived loss usually reflects a smell loss, which is often confused with a taste loss. In other disorders of the chemical senses, the system may misread and or distort an odor, a taste, or a flavor. Or a person may detect a foul taste from a substance that is normally pleasant tasting. People who experience smell disorders experience either a loss in their ability to smell or changes in the way they perceive odors.” Causes Like other human senses, our sense of smell and taste can be greatly affected simply by aging. In fact, scientists have found that the sense of smell begins to decline after age 60. Aside from age, anatomic blockage is one of the most common causes of smell dysfunction. Blockage can occur secondary to the existence of disorders of the nasal septum, polyps, or nasopharyngeal tumors. As Tierney explains, “Transient olfactory dysfunction often accompanies the common cold, nasal allergies, and perennial rhinitis. About 20 percent of olfactory dysfunction is idiopathic, although it often follows a viral illness.” Ackerman has
1646 Taste and Smell Disorders identified a number of commonly used prescribed medications that can impair the sense of smell including beta-blockers, the antibiotic Ciprofloxacin, and the antimetabolite Methotrexate. Disorders of smell and taste may also arise secondary to head trauma and resulting sheer stress on the olfactory nerve. A variation of olfactory disorders is the phenomenon of phantosmia in which olfactory hallucinations are experienced. Phantosmia has been associated with temporal lobe seizure activity as well as schizophrenia, and Alzheimer’s disease. Disorders of taste are commonly mentioned as side effects from the administration of various chemotherapeutic agents as well as the administration of radiation of the head and neck to treat cancer. A rare cause of anosmia or hyposmia is the genetic condition Kallmann syndrome, which results from a defect of forebrain development and is characterized by deficient gonadotropin hormone in humans. Diagnosis The proper identification of symptoms for taste and smell disorders begins with a thorough examination of the head and neck. Often, formal inspection of the nasal cavities is necessary and can be done with the help of an otolaryngologist who specializes in disorders of the ear, nose, and throat. Often, anatomical blockage can be corrected via surgery on the nasal septum or through the removal of nasal polyps. Because disorders of taste and smell are related to infection and resultant inflammation, some physicians may opt to treat the condition with a short course of oral steroids. Oral steroids decrease inflammation, and if this is the causation for the disorder, symptoms may temporarily abate. If symptoms are irreversible or progressive, imaging studies may be warranted to further characterize anatomy. Imaging used in the evaluation may include a computed tomography (CT) scan of the sinuses. CT of the head and or dedicated magnetic resonance imaging (MRI) may be useful to rule out other causes such as head trauma or tumor. Specific tests have been developed to better characterize disorders of smell and taste. According to Barker, “Odor identification is often tested using the University of Pennsylvania Smell Identification Test. In this test, a patient releases 40 microencapsulated odorants by rubbing designated areas on a card and answers corresponding ques-
tions about the identities of the orders. The answers are graded using normative data based on gender and age.” Scientists have developed taste testing in which the patient responds to different chemical concentrations. This may involve a simple “sip, spit, and rinse” test, or chemicals may be applied directly to specific areas of the tongue. Management The management and prognosis of disorders of taste and smell is primarily based upon the cause of the disorder. In instances where anatomic blockage is the cause, prognosis and recovery of function is good in cases that are amenable to surgical correction. As aforementioned, a number of cases may be idiopathic and/or secondary to antecedent infection with resultant inflammation of the oropharyngeal and nasal mucosa. In these instances taste and smell function can generally return to baseline levels when the inflammation has subsided. It is important to note that patients with taste and smell disorders should be counseled as to the nature of their disorders. Issues regarding quality of life may develop as patients may be unable to enjoy the taste of their once-favorite foods or appreciate the scent of their favorite flower. Just as sight and sound serve as protective mechanisms for humans, so too does taste and smell. Patients with disorders of smell should consider home appliance safety as they may be rendered unable to smell potential natural gas leaks in the household. So, too, should patients with taste disorders be counseled to examine the expiration dates of foods in the household. Patients with disorders of taste may not be able to identified potentially dangerous ingested substances such as sour milk. SEE ALSO: Alzheimer’s Disease; Otolaryngologist; Schizo-
phrenia.
BIBLIOGRAPHY. B.H. Ackerman, “Disturbances of Taste
and Smell Induced by Drugs,” Pharmacotherapy (v.17, 1997); R. Anholt, “Molecular Physiology of Olfaction,” American Journal of Physiology (v.247, 1989); L. R. Barker, “Anosmia,” Principles of Ambulatory Medicine (Lippincott, Williams & Wilkins, 2003); www.nlm.nih.gov/medlineplus/tasteandsmelldisorders.html (cited 2006); P. Moberg, “Scent of a Disorder,” Current Psychiatry Reports (v.4, 2003); C. Mur-
Tay-Sachs Disease
phy, “Prevalence of Olfactory Impairment in Older Adults,” Journal of the American Medical Association (v.288, 2002); Lawrence Tierney, et al., “Olfactory Dysfunction,” Current Medical Diagnoses and Treatment (Lange, 2006). Anil Seetharam, M.D. Washington University in St. Louis
Tay-Sachs Disease Tay-Sachs disease (TSD), or GM2 gangliosidosis, is a fatal genetic lipid storage disorder where harmful quantities of the fatty substance ganglioside GM2 build up in tissues and nerve cells in the brain. This is from insufficient activity of the enzyme betahexosaminidase A which catalyzes (speeds up) the breakdown of acidic fatty materials or gangliosides. This is especially important in the growing infant as gangliosides are produced and broken down rapidly as the brain develops. Globally, Tay-Sachs disease is underdiagnosed and undertreated. In the developing world, most healthcare facilities do not have the ability to properly diagnose this genetic disorder and lack the resource to ease suffering as TSD cannot be cured. Infants with TSD seem to develop normally for the first few months of life. However, as development continues, nerve cells grow and wrap in the fatty material that enables transmission. In TSD, an unhealthy accumulation occurs and stops this growth process. Blindness, deafness, and other simple actions such as swallowing become impossible. The British ophthalmologist Dr. Warren Tay first observed a red spot on the retina in the late 19th century and American neurologist Dr. Bernard Sachs was able to describe the cellular changes that occur in TSD. He was also able to identify an increase in TSD for those of eastern European Jewish (Ashkenazi) decent. Genetic Disorder More specifically, TSD is an autosomal recessive (not sex-linked and both parents must be carriers to have a child with TSD) disease that occurs when harmful quantities of the fatty acid derivative ganglioside accumulate in nerve cells in the brain. Ganglioside GM2 in Tay-Sachs disease is especially common in the ner-
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vous tissue of the brain. Mutations on chromosome 15 and specific to the hexosaminidase A (alpha polypeptide) or HEXA gene are what cause TSD. Many of these mutations have been discovered and more than 90 mutations have been identified in the HEXA gene. New mutations are still being reported and research is still under way. These mutations include base pair insertions and deletions, splice site mutations, point mutations, and other more complex patterns. Each of these mutations alter the protein product and inhibit the function of the enzyme in some manner causing TSD. Some populations have higher mutation frequencies than others. For example, French Canadians of southeastern Quebec and Cajuns from southern Louisiana have mutation frequencies similar to those mentioned for Ashkenazi Jews of eastern Europe. TSD can occur from inheritance of two unrelated mutations involving the HEXA gene with one being from each parent. Types The juvenile-onset form presents with loss of coordination and dementia. Death ensues by age 10 to 15 years. The adult-onset form is characterized by clumsiness in childhood with progressive motor weakness in adolescence and multiple and neurological disorders with balance, speech, and overall movement. Intelligence declines slowly, and psychosis can occur. Diagnosis A simple blood test looking for hexosaminidase A activity can diagnose TSD. Even though this disease is autosomal recessive and both parents have to carry the gene, it is only a 25 percent chance that the child will be born with TSD. Furthermore, prenatal monitoring in the fetus by chorionic villus sampling or amniocentesis is an option. Screening for Tay-Sachs disease carriers is recommended in the Ashkenazi Jewish population. Proactive testing has been quite effective in eliminating Tay-Sachs occurrence among Ashkenazi Jews. Of the 10 babies born with Tay-Sachs in North America in 2003, none were born to Jewish families. In Israel, only one child was born with Tay-Sachs in 2003, and preliminary results from early 2005 indicated that none were born with the disease in 2004. If both parents are identified as carriers, prenatal genetic testing can determine whether the fetus has inherited a defective copy of the gene from both parents.
1648 Teenage Pregnancy Treatment There is currently no cure or treatment for TSD. Even with the best care, children with infantile TSD die at an early age, and the progress of late-onset TSD can only be slowed, not reversed. However, several methods of treatment can be deployed to ease suffering and to assist with breathing and eating and physical therapy. Most of these are not available in the developing world. Last, much research is being done to try to treat TSD through enzyme replacement therapy, gene therapy, and metabolic therapy. Sadly, these treatment measures are still in their infancy and cannot offer help to those suffering from TSD. As mentioned earlier, eastern European Ashkenazi Jews have a high incidence of TSD. Documentation of this incidence is recorded as early as the 15th century. Furthermore, Irish Americans exhibit a one in 50 chance of being a carrier of the disease. TSD is a debilitating and irreversible neurological disease and affects many throughout the world with no available cure. SEE ALSO: Child Development; Developmental Disabilities;
Ecogenetics; Genetic Disorders; Israel; Metabolic Disorders.
BIBLIOGRAPHY. Julie Walker, Genetic Diseases and Disor-
ders: Tay-Sachs Disease (Rosen, 2006); Lorri A. Zipperer, ed., The Health Care Almanac: A Resource Guide to the Medical Field (American Medical Association, 1995)..
John Michael Quinn V, M.P.H. University of Illinois at Chicago
Teenage Pregnancy The age at which it is appropriate for women to have children can vary within a culture, between cultures, and certainly, over time. One hundred years ago, it was not uncommon for 15- and 17-year-old girls to be married and having their first children. Today, the majority of American society would look down upon this practice. In Western cultures where women’s education and independence is highly valued, the average age of marriage for women is 25.3 years. In many developing countries, women marry much younger and begin having children during their teenage years. Despite
this fact, inside a Western context, teenage pregnancy is perceived as a public health problem that needs to be addressed. It is associated with delayed initiation of prenatal care, poor prenatal health behaviors, and low birth weight infants. Even healthy infants born to young mothers have an increased risk of post-neonatal death. In addition, teenage pregnancy is associated with increased rates of sexually transmitted infections, substance abuse, rapid repeat pregnancy, and sexual violence. Vital Statistics While pregnancy rates among teenagers have been declining in the United States over the past 15 years, approximately 800,000 to 900,000 young women under 20 years of age become pregnant each year and more than half choose to give birth. One-fifth of these women will have another child within two years. Studies indicate that three-quarters of all teenage pregnancies are unplanned and only one-third end in voluntary termination. Young adults who are exploring their sexuality may believe they are unlikely to conceive and fail to consider the consequences of their actions. However, nearly one in five girls becomes pregnant during her first sexual relationship and half of all teenage pregnancies occur less than six months after sexual debut. A sexually active teenage girl who is not using birth control stands an 85-percent chance of becoming pregnant within one year. It is important to remember that teenagers who become pregnant are not a homogenous group. Not only do they vary in ethnicity, culture, religion, and age, but they also vary in terms of intentional conception. Some have postulated that there are three subgroups of teenage girls who become pregnant: (1) those who willingly engage in a variety of risky behaviors including unprotected sex; (2) those using sexual intercourse to fulfill unmet emotional needs or create familial bonds; and (3) relatively normal girls who choose a different life path including starting a family at a young age. Intentional versus Unintentional Teenage Pregnancy It is important to acknowledge that some young women intend to conceive. Understanding their motivation is essential to reaching this population with
effective sexual health, contraception, and antenatal care messages. In a study of the attitudes of pregnant teenage girls, researchers found that reasons for planning a pregnancy included love of infants, having someone to love and be loved by, being closer in age to the child, and having more family/partner support as a young mother than an older mother who would have to accept more responsibility. Pregnant teenagers with negative attitudes about their pregnancy are more likely to have had mother– daughter discussions about the negative consequences of teenage pregnancy, strong maternal disapproval of teenage pregnancy, and greater satisfaction with their own mother–daughter relationship. Pregnancy results from unprotected sexual intercourse, and teenage girls engaging in unprotected sexual intercourse are also putting themselves at risk
Raising a baby is difficult at any age, but especially so for young mothers who may not be emotionally or psychologically equipped.
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for sexually transmitted infections (STIs) including human immunodeficiency virus (HIV)/AIDS. U.S.based research indicates that teens represent 25 percent of the 15 million new cases of STI diagnosed each year. Within the population of sexually active teens, pregnant girls were almost twice as likely to have an STI as their never-pregnant peers. Raising a baby is difficult at any age, but especially so for young mothers who may not be emotionally or psychologically equipped for this burden. Some teen parents turn to drugs and/or alcohol for stress relief to compensate for a lack of social support and some had a substance abuse problem prior to pregnancy. Although some substance users manage to quit during pregnancy, research shows that they typically begin to reuse or continue to use after delivery. Young, unmarried pregnant women with less than a high school education have the highest rates of drug use. This is not without consequences as drug abusing teenage mothers have poorer relationships with their babies and their babies show evidence of greater stress than their nondrug-using counterparts. This, coupled with the fact that substance abuse and mental health disorders coexist in many teenagers (and in teenage parents), is an area of concern. Some researchers suggest that all pregnant teenagers should be screened for both mental heath disorders and substance abuse problems. Teenagers who have given birth to a baby are at risk for rapid repeat pregnancy, defined as a subsequent pregnancy within two years. It is recommended that children be spaced more than two years apart because the arrival of a child within 24 months of a previous child is associated with worse medical, financial, educational, and psychological outcomes for young mothers. In 1996, 22 percent of all births to girls 15 to 19 years of age were repeat births. By 2002, this number trended down to 20.5 percent, but this illustrates that one in five deliveries of teenage girls are repeat births. Young girls who were exposed to sexual coercion or rape have a greater likelihood of becoming pregnant as teenagers. They are also at increased risk of subsequent unintended pregnancy within two years. In resource-deprived settings, there are a host of other factors to consider. Young girls may not have fully developed pelvises capable of delivering a baby, especially when combined with nutritional deficiencies and stunted growth so often present in the developing
1650 Telepathology world. Teenage pregnancy in this context can be quite dangerous for both the mother and the baby. Prolonged or obstructed labor for a woman without access to emergency obstetric care can be devastating. She is at risk for obstetric fistula, a condition in which a connection is formed between the bladder and the vagina or the bladder and the rectum creating a continuous leakage of fluid and/or feces from the vagina. These women become social outcasts, unable to work or live with their families. In addition, the baby is unlikely to survive a prolonged, obstructed labor. Education and Prevention Accurate information about sexuality and contraception are essential to the prevention of unwanted teenage pregnancy. Until the last 10 years, the majority of America’s youth were exposed to sex education in secondary schools. However, changes in the political climate have led to an increase in abstinence-only education programs in U.S. schools. In a position paper published in 2006, the Society for Adolescent Medicine resolutely condemned the practice of abstinence-only education policies and programs in the United States. In summary, it argues that there is no scientific data that these programs effectively promote abstinence or prevent pregnancy or STI, and the inherently unethical nature of withholding valuable health information from a segment of the population. There is a real human right to sexual health information and censoring it is tantamount to a human rights violation against adolescents. They believe abstinence is an important message within a comprehensive educational program, it just should not be the only message. SEE ALSO: Abortion; Cervical Cancer; Obstetrics; Ob-
stetrician/Gynecologist; Pregnancy; Sexually Transmitted Diseases; Substance Abuse and Mental Health Services Administration (SAMHSA).
BIBLIOGRAPHY. L. A. Boardman, et al., “Risk Factors for
Unintended versus Intended Rapid Repeat Pregnancies among Adolescents,” Journal of Adolescent Health (v.39, 2006); C. B. Boyer, et al., “Acquisition of Sexually Transmitted Infections in Adolescents Attending an Urban, General HMO Teen Clinic,” Journal of Adolescent Health (v.39, 2006); M. R. Gillmore, et al., “Women Who Gave Birth as Unmarried Adolescents: Trends in Substance Use from Adolescence to Adulthood,” Journal of Adolescent Health
(v.39, 2006); C. Rosengard, et al., “Concepts of the Advantages and Disadvantages of Teenage Childbearing among Pregnant Adolescents: A Qualitative Analysis,” Pediatrics (v.118/2, 2006); H. M. Truong, et al., “Abstinence-Only Education Policies and Programs: A Position Paper of the Society for Adolescent Medicine,” Journal of Adolescent Health (v.39, 2006). Megan K. Guffey, M.D., M.P.H. Independent Scholar
Telepathology Telepathology is defined as the use of communication technology to facilitate the transfer of histological, cytological, and macroscopic images between remote locations for the purposes of diagnosis, consultation, education, and research. With the growing workforce shortage of certified pathologists evident in the United States, telepathology offers a very good solution. Yet, questions remain regarding how best to use the available technology and overcome the current adoption challenges, thus allowing telepathology to become an integral element of mainstream care delivery. Although the different applications for telepathology are numerous, the bulk of research has concentrated on its use as a diagnostic tool. Some of the applications include providing urgent services at sites where pathologists are in short supply or in cases were a second opinion is required. This is extremely useful in rural areas where the closest pathologist is several hours away and a primary care physician needs to diagnose a disease. Telepathology has also been used for research applications, distance education, quizzes, and online atlases with great success. The three main approaches used currently for telepathology are store-and-forward (static), dynamic (real-time), and hybrid (virtual slides). The first is time and place independent, while the second and third operate in real time but bypass geographical boundaries. All three forms share the limitation of image quality, which often make it difficult for pathologists to make a diagnosis. In store-and-forward telepathology, pathologists select images, store them on a com-
Telesurgery
puter, and forward the image to other pathologists at remote sites. The advantage of this method is that it is inexpensive, and has been shown to have concordance rates as high as 95 to 100 percent between traditional glass slide and telepathology diagnosis. However, limitations include diagnostic errors attributed to the inappropriate field selection by the submitting pathologist. In addition, only a small number of images can be transmitted at one time. Real-time telepathology involves using a microscope along with a personal computer to send images. This system is very costly, but has revolutionized the field, demonstrating concordance rates of 99 to 100 percent between telepathology and light microscopy diagnosis. Hybrid systems utilize an automated scanner that takes visual images of the entire slide at a very high resolution, which is forwarded to another location for diagnosis. The biggest advantage of this method is that it can be viewed by multiple pathologists without any loss of resolution. It allows one to see the slide in different magnifications, just like a microscope, without the need of having multiple images. Because the effectiveness and accuracy of telepathology depends critically on the skill and judgment of the pathologist, both referring and consulting pathologists practicing telepathology should be trained in telepathology. This training includes general telepathology, imaging principles, and its limitations. Technological advances over the last decade have transformed the internet, digital cameras, and digital imaging applications. These factors present a real opportunity to develop telepathology into an integral part of the healthcare system. SEE ALSO: Pathologist; Pathology.
American Telemedicine Association, “Clinical Guidelines for Telepathology,” http://telepathology.upmc.edu/ata/guideline.htm (cited January 2007); M. K. Baruah, “The Practice of Telepathology in India,” Journal of Postgraduate Medicine (v.51, 2005). BIBLIOGRAPHY.
Jared D. Ament, M.D. MPH Harvard Medical School Harvard School of Public Health Hagit Bergman University of Louisville
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Telesurgery Telesurgery is a medical technology that allows a surgeon to operate from long distance; hence it is also known as remote surgery. This is clearly relevant to global health, as a surgeon from one country could feasibly operate on a patient many thousands of miles away in a different country. A large country with relatively few surgeons, such as Canada, will greatly benefit from this technology as well. Since the first telesurgery case did not occur until 2001, the 21st century and beyond will witness remarkable advancements in the field. The technologies that built up to the possibility of telesurgery were laparoscopy and computer-assisted surgery. In laparoscopy, available since the 1980s, a long, small-diameter cylindrical apparatus is inserted into the anatomical area of interest, usually the abdomen. Through that thin tube, a surgeon can insert a small camera that transmits the image of the surgical field onto a television screen. A surgeon can also perform a surprising number of procedures through that small opening, including cholecystectomies, Fallopian tubal ligation, and even hysterectomies. In computer-assisted surgery, developed in the 1990s, robotic arms that actually perform the procedure are controlled by a surgeon who sits several feet away from the surgical field. The advantages of computerassisted surgery include the elimination of normal tremor of a surgeon’s hands, excellent three-dimensional visualization and magnification, and reduction of a surgeon’s fatigability. The first true telesurgical case, known as Operation Lindbergh, was successfully completed on September 7, 2001. The patient was located in Strasbourg, France while the surgeon operated 4,300 miles away in New York City, United States. A laparoscopic cholecystectomy (gallbladder removal) was performed without complications. The most remarkable aspect of Operation Lindbergh was the minimal trans-Atlantic time delay of just 0.135 second. Telesurgery has opened unlimited possibilities in the treatment of surgical patients and the training of surgical specialists. Training of new surgeons by any world expert is now more feasible. Other potential applications of telesurgery include assisting surgeons and treating patients in rural areas, developing countries, war zones, and even outer space. The implications of helping soldiers on the battlefield are particularly intriguing and being worked
1652 Temporomandibular Joint Dysfunction on by the United States’ Defense Advanced Research Projects Agency (DARPA), while aerospace surgery is a project of the National Aeronautics and Space Administration (NASA). Both projects hope to be in use by the year 2010. Some disadvantages to telesurgery requiring improvement include the issues of time delay and reducing the size of the equipment needed. Developments in telesurgery continue at a rapid pace in several different medical fields, including otorhinolaryngology, urology, gynecology, and gastroenterology. Urologists can perform prostatectomies (removal of the prostate gland for conditions such as prostate cancer) via telesurgery, and gynecologists can remove uterine fibroids. Gastroenterologists are performing telesurgical procedures to correct gastroesophageal reflux disease (GERD). Research is progressing toward integrating telesurgery into other surgical fields, too. One day, telesurgery may be a very viable option to any patient requiring any surgical intervention. SEE ALSO: Acid Reflux; Gall Bladder and Bile Duct Dis-
eases; Gastroesophageal Reflux/Hiatal Hernia; Prostate Cancer; Prostate Diseases. BIBLIOGRAPHY. Anthony J. Senagore, The Gale Encyclope-
dia of Surgery: A Guide for Patients and Caregivers (Thomson Gale, 2003) Khoi D. Than, M.D. Johns Hopkins University School of Medicine
Temporomandibular Joint Dysfunction Temporomandibular disorders (TMDs) are a heterogeneous collection of disorders characterized by orofacial pain and/or masticatory dysfunction. TMDs are more commonly reported by women, typically in their 30s, than by men. A dual-axis diagnostic system utilizes both physical examination procedures and assessment of a patient’s psychological state. The National Institutes of Health strongly recommends conservative, reversible treatments for TMDs. The pain reported by TMD patients is typically located in the muscles of mastication, in the preauricu-
lar area, or in the temporomandibular joint (TMJ). TMD patients may also report headache, other facial pains, earache, dizziness, ringing in the ears, and neck, shoulder, and back pain. TMD patients may report a variety of TMJ problems other than pain, including locking in the open or closed position, and TMJ clicking, popping, and grating sounds. Patients may report difficulty opening their jaws wide as well as a sense that their occlusion feels “off.” The spectrum of symptoms leads patients to seek care from dentists, physicians, and other health professionals. The prevalence of TMD varies by age and gender. Unlike many joint-related conditions, TMD is more prevalent in those under age 45. The prevalence ratio for females versus males is approximately 2:1 when nonclinic populations are assessed. However, the ratio can be as high as 8:1 in patient samples. Prevalence rates of TMD vary dramatically, depending on the definition of the condition. Estimates suggest that 4.5 percent of the adult population report pain and dysfunction sufficiently severe to prompt help seeking. Most cases of TMD involve either muscle pain, problems with the articular disc of the TMJ, degenerative changes in the TMJ, or a combination of these. The most widely researched and best validated system for assessing TMD is based on the Research Diagnostic Criteria (RDC) for TMD. This is a dual-axis system assessing physical disorders on Axis I and self-reported pain, disability, and psychological symptoms on Axis II. For Axis I, patients may receive a diagnosis of myofascial pain, one of several forms of disc displacement, and/or a diagnosis referring to joint problems. Axis II evaluation provides information on current pain levels, disability, depression, and somatization and may be helpful with treatment planning. The National Institute of Dental and Craniofacial Research strongly recommends conservative, reversible treatments for patients with TMD. Among these treatments are interocclusal appliances, medications, self-care strategies, physical therapy, and behavioral interventions. Interocclusal appliances are also known as mouth guards or “splints.” The most commonly used interocclusal appliances are fabricated from hard acrylic, placed on either the mandibular or maxillary teeth, and cover the occlusal surfaces of all the teeth. The occlusal side of the
Testicular Cancer
appliance typically presents a relatively flat surface to the opposing teeth. Interocclusal appliances can also be fabricated from softer materials, cover only a portion of the teeth, and maintain the jaw in a fixed position. There is general consensus that splints reduce TMD pain, although the mechanism of action is unknown. Clinicians frequently use nonsteroidal antiinflammatories to reduce pain in TMD patients; low-dose regimens or tricyclic antidepressants may also reduce pain in select patients. Self-care regimens involve the use of hot/cold packs for controlling pain, identifying and avoiding triggers for pain (e.g., hard, chewy foods), and avoiding unnecessary behaviors involving the jaw (e.g., biting fingernails). Physical therapy exercises emphasize gentle stretching exercises performed at home. The psychological interventions show considerable promise in the treatment of TMD pain. Many of these programs use cognitive-behavioral techniques, often combined with biofeedback, to manage pain, and they show good long-term results. SEE ALSO: Dental Health; Headache and Migraine; Pain. BIBLIOGRAPHY. Alan Glaros and Ernest G. Glass, “Tem-
poromandibular Disorders,” in Robert J. Gatchel and Edward B. Blanchard, eds., Psychophysiological Disorders (American Psychological Association, 1993); Mark Drangsholt and Linda Le Resche, “Temporomandibular Disorder Pain,” in Iain K. Crombie, et al., eds., Epidemiology of Pain: A Report of the Task Force on Epidemiology of the International Association for the Study of Pain (IASP Press, 1999); Sam Dworkin and Linda LeResche, “Research Diagnostic Criteria for Temporomandibular Disorders: Review, Criteria, Examinations and Specifications Critique,” Journal of Craniomandibular Disorders (v.4, 1992). Alan Glaros Kansas City University
Testicular Cancer Testicular cancer is cancer of the testicles, which are small ovular organs flanking the base of the penis and
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producing testosterone and sperm. The cancer typically affects only one of the two testicles. Women do not have testicles and therefore do not develop testicular cancer. Testicular cancer has one of best cure rates of all cancers, male or female. If the cancer has not metastasized into other tissues, the cure rate is greater than 95 percent. If the cancer has spread, then the cure rate drops only slightly, reaching about eighty-five to ninety percent. While scientists have been unable to find a cause of testicular cancer, several risk factors have been identified. These risk factors for developing testicular cancer include having had abnormal testicular development, a testicle that never naturally descended (including one that was surgically relocated to the descended position), or a family history of testicular cancer. Overall, the incidence rate of testicular cancer is about one in 250 men; it is far more common in Caucasians than in men of other races. Testicular cancer is quite rare in African Americans, as well as on the continents of Asia and Africa. Globally, the occurrence of testicular cancer is most common in New Zealand, the Scandinavian countries, and Germany. An additional risk may be an infected status with HIV, or living with AIDS. While testicular cancer is the most common cancer in the United States in males aged fifteen to thirty-four years, the stigma and embarrassment regarding the testicles have left this cancer under-discussed and sometimes have prolonged the seeking of an examination by a physician, and therefore diagnosis and therapy. It is therefore important for males to inspect their testicles routinely for any changes in size, shape, or texture, and to report these changes to a physician immediately. Lumps in the testicles don’t always cause pain, even if they are cancerous. Some of the most common signs and symptoms of testicular cancer include pain in the testicular region or groin, lumps in this area, or swelling. Additional symptoms can include accumulation of fluid in the scrotum (which is the sack that contains the testicles), a heavy feeling in the scrotum, aches in the scrotal area, tenderness or enlarged size of the male breasts, or a general feeling of malaise. The symptoms of affected breasts are rare, and occur when the testicular tumor is the type that secretes high amounts of human chorionic gonadotropin (HCG), a hormone that
1654 Tetanus stimulates breast development, among other physiological reactions. If the tumor is in a cell that produces estrogen or androgens, the male may experience symptoms that can aid the physician to reach a diagnosis. High levels of estrogens in males may result in breast growth and loss of sexual desire. High levels of androgens in men may not cause any noticeable symptoms; however, in younger boys they may cause precocious puberty in terms of facial and/or body hair. Some tumors do not produce any symptoms, and are found during a routine examination or an examination into the cause of a man’s infertility. There are several examination options for diagnosis of testicular cancer. The physician may perform an exam to identify any concerning lumps in the testicles as well as the surrounding lymph nodes. Additionally, an ultrasound may be used to visualize the internal testicular environment and highlight any suspicious growths. Some types of testicular cancer may cause elevated levels of hormones or proteins in the blood; blood tests can therefore be helpful in diagnosing testicular cancer. Particular proteins involved may be alpha-fetoprotein (AFP), HCG, and lactate dehydrogenase (LDG). Other medical imaging options are a Computed Tomography (CT) scan, Lymphangiogram (rarely used today as it has been replaced by the CT scan), Magnetic Resonance Imaging (MRI), a Positron Emission Tomography (PET) scan, and X-ray. Because the testicles contain several types of cells, there are several types of testicular cancer that can develop from these cells. These types are germ cell (seminomas), non-germ cell (nonseminomas), and secondary tumors. Secondary tumors are typically leukemia or lymphoma related, or from metastasis from other tissues. Seminomas typically develop in men between the ages of thirty-five and fifty-five years. These tumors, when caught early, are nearly always treatable. Nonseminomas are those tumors which can be classified as choriocarcinoma, embryonal carcinoma, teratoma, and yolk sac tumors. A teratoma is a tumor with parts that stem from all three germ layers. These tumors are the ones which may include hair, teeth, and skin. A diagnosed testicular cancer must next be staged using a standard accepted classifying system. Testicular cancer can be classified into three stages, I-III, with the lowest stage being the least advanced. Stage I
testicular cancer has not spread to any tissue beyond the testicle. Once the testicular cancer has spread to surrounding lymph nodes, which drain tissues, it is classified as Stage II. If the cancer metastasizes and invades distant tissue such as the bone, is it classified as Stage III. Once testicular cancer has been diagnosed and staged, the most common treatment is surgery. The surgery most commonly removes the tumor along with the affected testicle, and often the spermatic cord, which is made of vasculature and lymph vessels. Chemotherapy and radiation therapy may also be used, independently or in conjunction with each other, and in increasing doses as the stage of the tumor advances per patient. A choriocarcinoma is the type of tumor that is most sensitive to chemotherapy. A major side effect of testicular cancer treatment is often infertility; men who may wish to have children in the future are therefore recommended to store their sperm as a precaution. SEE ALSO: American Fertility Association; American
Society of Clinical Oncology (ASCO); Cancer (General); Cancer Alternative Therapy; Cancer Chemotherapy; Cancer Radiation Therapy; Cancer – Coping with Cancer; Chemoradiotherapy; Chemotherapy; Colorectal Cancer; Male Genital Disorders; National Cancer Institute (NCI); National Coalition for Cancer Survivorship (NCCS); National Program of Cancer Registries (NPCR); Oncologist; Oncology; Penile Cancer; Prostate Cancer. BIBLIOGRAPHY. American Cancer Society, “How is Tes-
ticular Cancer Diagnosed?”, www.cancer.org (cited August 2007); Lance Armstrong and Sally Jenkins, It’s Not About the Bike: My Journey Back to Life (Berkley Trade 2001); ICON Health Publications, Testicular Cancer – A Medical Dictionary, Bibliography, and Annotated Research Guide to Internet References (ICON Health Publications, 2004). Claudia Winograd University of Illinois at Urbana-Champaign
Tetanus Tetanus is a bacterial infection that affects the nervous system. It is estimated that there are one million cases
Tetanus
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of tetanus per year worldwide, the majority occurring in developing countries. Neonatal tetanus is particularly dangerous, often caused by non-sterile delivery methods and incomplete vaccination. According to the WHO, over 200,000 cases/year of neonatal deaths from tetanus occurred in the year 2000. In the U.S. however, with widespread vaccination, only 50 cases of the disease occur per year. The Bacterium Clostridium tetani, the organism that causes a tetanus infection, is an anaerobic, sport forming, gram-positive bacterium. Its spores are ubiquitous in soil, and are also found in dust and animal feces. Infection can occur through any open wound: cuts, scrapes, needle injection sites, the umbilical cord, insect bites. The infection rate is higher if the wound is contaminated with soil or caused by wood splinters or dirty, rusty metal. Neonatal tetanus is most often caused by the use of dirty instruments (scissors, clamps, etc.) to cut the umbilical cord. After the organism enters an open wound, bacterial spores germinate in an anaerobic (low oxygen) environment and release the neurotoxin tetanospasmin. This toxin acts on the myoneuronal (muscle-nerve) junction to inhibit the ability of muscles to relax. Symptoms Symptoms of a tetanus infection usually arise one to two weeks after exposure. The tetanus toxin prevents muscles from relaxing, causing a condition known as “spastic paralysis.” In other words, the muscles are locked in the contracted position, leading to a stiff jaw, stiff neck, and the contraction of facial muscles resulting in a sneering expression known as risus caninus. In newborn children, if tetanus is acquired during delivery, symptoms arise by the end of the first month of life. Symptoms include stiff muscles, fever, and poor feeding. Muscle spasms, also known as “tetany” are associated with a more advanced stage of the disease and a poor prognosis. Complications and Prognosis These muscle spasms can be violent enough to cause spinal fractures. Tetanus has also been associated with abnormal heart rhythms. In adults, with proper
A history of past tetanus infection does not make a patient immune to another infection, so these patients must also be vaccinated.
treatment, the overall prognosis is good. For children however, prognosis is poor and often results in death. The overall mortality rate of tetanus is 10 percent. Treatment & Prevention Tetanus infections are treated with antibiotics (penicillin or metronidazole) and tetanus antitoxin. The antitoxin is an immunoglobulin that neutralizes tetanospasmin. In severe cases, patients may be unable to breathe independently and they must be place on mechanical ventilation. The disease can be prevented using a vaccine and by hygienic and sterile wound care and childbirth. In the US, the vaccine is given as the combination vaccine DTaP at 2, 4, 6, and 15 months, and 5 years of age. A booster is then given every 10 years, or after an injury if the last booster was more than 5 years prior. Unvaccinated adults get a three injection series over seven months. A history of past tetanus infection does not make a patient immune to another infection, so these patients must also be vaccinated. Pregnant women should be vaccinated to pass on some immunity to the newborn child, this can be done while the woman is pregnant. Other countries use different vaccine combinations, including formulations with the hepatitis A and Haemophilus influenzae B (HiB) vaccines. Practically speaking, tetanus is prevented by thoroughly cleaning wounds, giving a booster vaccine to
1656 Thailand individuals with an unknown vaccination history, and the use of sterile instruments during childbirth. The WHO, UNICEF, and the UNFPA are following these guidelines to reduce neonatal tetanus in developing countries. Their strategies include increased vaccination of pregnant women, vaccinating all women of child-bearing age in endemic areas, and promoting clean delivery methods. SEE ALSO: Botulism; World Health Organization (WHO). BIBLIOGRAPHY. Center for Disease Control and Preven-
tion, www.cdc.gov/nip/diseases/tetanus/; Daniel J. Dire, “Tetanus,” www.emedicine.com/emerg/topic574.htm (cited December 2005); Elias Abrutyn, “Tetanus,” in Harrison’s Principles of Internal Medicine, 15th ed. (McGraw-Hill, 2001); World Health Organization, “Tetanus,” www.who. int/topics/tetanus/en (cited May 2006). Amit Chandra, MD, M.Sc. NY Hospital Queens
Thailand Thailand is located in southeast Asia. It is bounded to the east by Laos and Cambodia, to the west by Myanmar, and to the south by Malaysia, and has long coastlines on the Andaman Sea and the Gulf of Thailand. Once the powerful Kingdom of Siam, it is the only nation in the region that was never colonized by outside powers. Thailand is trying to find a balance between its rich cultural heritage and its rapidly industrializing economy. In 2006, the government was overthrown by a military junta, and there are ongoing reports of political repression and human rights violations against the people. The population of Thailand is around 65,000,000 and is growing a rate of 0.663 percent annually. The birth rate is 13.73 per 1,000 and the death rate is 7.1 per 1,000. Median age is 32.4 years. Life expectancy is currently 70.24 years for males and 74.98 years for females. Gross national income is $2,750 per person, with 10 percent defined as living in poverty. Thailand has a well-developed and diversified economy. Unemployment is just 2.1 percent. The Thai people can suffer from a wide variety of communicable disease, despite good ac-
cess to clean water and sanitary facilities. There is a risk of bacterial diarrhea, viral hepatitis, dengue fever, malaria, Japanese encephalitis, plague, leptospirosis, and rabies. The prevalence rate for tuberculosis is 204 cases per 100,000. The country has a well-developed TB control program, and has a 85 percent cure rate for TB cases. With a thriving drug and sex trade, the HIV/AIDS prevalence rate is 1.4 percent, with an estimated 580,000 cases, 220,000 of them women. Non-communicable diseases are increasing as a major health threat for the Thai people, as the country is rapidly adopting a more “modern,” urban lifestyle. A 2000 survey found that 42 percent of people ate fast food regularly, and only 25 percent said they got regular exercise. In 1993, 23 percent of those over the age of 15 were daily smokers. Thailand was one of the countries devastated by the Boxing Day tsunami in December 2004. In all, 1,940 Thai nationals were killed, 6,065 were injured, and 2,023 were declared missing. For several months after the tsunami, there were heightened rates of acute diarrhea, wound infections, food poisonings, pneumonia, malaria, and dengue fever in the region. Researchers found that the prevalence of post-traumatic stress disorder (PTSD) was twice as high in children living in the six affected provinces than those who lived elsewhere in the country, and that the level of trauma had not gone down when the children were re-tested nine months later. Rates of anxiety and depression were elevated in the adult population as well. Overall, child mortality rates in Thailand are low, with 18 deaths per 1,000 in infants, and 21 deaths per 1,000 in children under 5. Thai children have enjoyed much better health over the past decade. However, UNICEF estimates that more than 1 million children are in need of protection, either because they have been orphaned or abandoned, or are disabled. The Thai government estimates that 60,000 children have been sold into prostitution in recent years. Tens of thousands of women, both Thai and imported foreign nationals, have also been trafficked into the country’s flourishing sex trade. Violence against women is widespread in Thailand, with rape and domestic battering the most common violent crimes in the country. There are 92 regional hospitals, 707 community hospitals, 9,559 health centers at the district or village level, 61,432 rural clinics and 808 urban clinics. In 2000, there were 22,435 physicians, or 0.37 per 1,000.
Third World
There were also 171,605 nurses, or 2.82 per 1,000. The Thai government currently spends around $57 per capita on healthcare. SEE ALSO: Healthcare, Asia and Oceania; Mental
Health.
Bibliography. Centers for Disease Control and Preven-
tion, “Important CDC Findings Published on the Mental Health of People in Tsunami-Affected Areas in Southern Thailand,” www.bt.cdc.gov/disasters/tsunamis/jama02aug2006.asp (cited July 2007); Central Intelligence Agency, “Thailand,” CIA World Factbook. www.cia.gov/library/publications/the-world-factbook/geos/th.html (accessed July 15, 2007); The Joint United Nations Programme on HIV/AIDS, “Thailand,” www.unaids.org/en/Regions_ Countries/Countries/thailand.asp (cited July 2007); United Nations Children’s Fund, “Thailand—Statistics,” www. unicef.org/infobycountry/Thailand_statistics.html#30 (cited July 2007); World Health Organization, “Thailand: Country Profile,” WHO/Western Pacific Regional Office. www.searo.who.int/LinkFiles/Thailand_thailand.pdf (cited July 2007). Heather K. Michon Independent Scholar
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In contrast to the modernization theories of the 1950s (which, based on the notion of progress, posited that countries would undergo a stage-like process of economic development), dependency and world-system analyses argue that “Third World” countries are poor not because they have not integrated into the world economy or because they have not had enough time to develop, but because their position in the world economy is one of dependency. As such, countries in the “periphery” play a secondary role in the global economy; they provide raw natural resources, cheap labor, and a market for excess goods from the “core” countries. These notions have been discussed primarily by Andre Gunder Frank (who developed a Marxist version of dependency theory) and Immanuel Wallerstein (founder of the world-system theory in sociology). A more contemporary framework developed by the UNDP uses a distinction based on the notion of human development. Every year, the UNDP publishes a Human Development Report which presents the rank ordering of countries on the human development index (HDI). The index reflects a country’s level of population health (operationalized as life expectancy at birth), education (operationalized with two
Third World An anachronistic term used to differentiate “developing” countries from the industrialized countries of the West (the “first world”), and the communist countries of the Soviet bloc (the “second world”). It is also often used synonymously with the phrase “less developed country,” and as such is applied to countries with relatively low levels of Gross Domestic Product (GDP) per capita. An alternative framework, based on the notion of human development, has been developed by the United Nations Development Programme (UNDP). The term Third World is still in use today by social researchers, although its usefulness has diminished since the end of the Cold War. The term has also been criticized by dependency and world-systems analysts for not acknowledging the interdependent nature of the global economic system.
The term Third World is still in use today by social researchers, although its usefulness has diminished since the end of the Cold War.
1658 Thomas, Lewis measures: adult literacy rate and gross enrollment ratio), as well as standard of living (operationalized as GDP per capita). The resulting index has a theoretical range of close to 0 (extremely low human development) to 1 (extremely high human development). Based on HDI values, the UNDP classifies countries as having high human development (reflecting HDI values of 0.800 or more), medium human development (HDI of 0.500–0.799), and low human development (HDI of less than 0.500). There is considerable overlap between a classification of a country as being considered part of the “Third World” and it having a medium or low HDI classification. SEE ALSO: Disease and Poverty; Farmer, Paul; Refugee
Health; Sachs, Jeffrey; World Health Organization (WHO).
BIBLIOGRAPHY. Paul Farmer, Pathologies of Power: Health,
Human Rights, and the New War on the Poor (University of California Press, 2003); Immanuel Wallerstein, The Capitalist World-Economy (Cambridge University Press, 1979); Laurie Wermuth, Global Inequality and Human Needs: Health and Illness in an Increasingly Unequal World (Allyn & Bacon, 2003). Fernando De Maio, Ph.D. Simon Fraser University
Thomas, Lewis (1913–93) Born in 1913 in New York, Lewis Thomas’s father was a physician and his mother was a nurse. Thomas became well known for his research on immunology and receives credit for turning it into a scientific discipline. He is perhaps better known for his engaging style of writing in his essays and books that made scientific learning accessible to the masses. Intrigued by the medical profession at a young age, Thomas was accepted into Princeton at the age of 15, where he enjoyed writing poetry. Accepted into Harvard’s Medical School in 1933, he graduated in 1937 and interned at Boston City Hospital, selling blood for cash and poems to the Atlantic Monthly, Harper’s Bazaar, and the Saturday Evening Post. After completing a neurology residency at Columbia Presbyterian Medical Center, he married Beryl
Dawson in 1941. The following year, he was called up by the Navy Reserve and began working as a medical researcher in the Pacific. After the war ended, he practiced pediatrics at Johns Hopkins, where he began researching rheumatic fever. In 1948, Thomas worked as a researcher at Tulane University. Two years later, he moved to the University of Minnesota to continue his work on rheumatic fever. In 1954, he was named head of pathology at the New York University Medical School; this was where his immunology work came to the forefront. He stayed there until 1969, when he moved to Yale University. In 1973, he was named president of the Sloan-Kettering Institute in New York, focusing on cancer research. In 1971, Thomas began writing a monthly essay called “Notes of a Biology Watcher” for the New England Journal of Medicine. From the 1970s until the 1990s, Thomas published a number of books, starting with The Lives of a Cell: Notes of a Biology Watcher in 1974, which sold 1.5 million copies and won the National Book Award. His topics were generally scientific in nature, focusing on microbiology and immunology, but they also contained meditations on nature. In 1986, Princeton opened its Lewis Thomas Laboratory. Thomas died in December 1993 of a rare blood disorder called Waldenstrom’s disease. SEE ALSO: Immunology; Rheumatic Heart Disease. BIBLIOGRAPHY. National Public Radio, “Science Writer
Dr. Lewis Thomas Dies at 80,” All Things Considered, December 3, 1993, www.highbeam.com/doc/1P1-28002644. html (cited March 2007); Ann Woodlief, Dictionary of Literary Biography, Volume 275: Twentieth-Century American Nature Writers, Virginia Commonwealth University, www. vcu.edu/engweb/LewisThomas.htm (cited March 2007). Kelly Boyer Sagert Independent Scholar
Thoracic Outlet Syndrome Thoracic outlet syndrome (TOS) is the name given for a spectrum of symptoms caused by compression of the brachial nerve plexus, which innervates the arm, and the subclavian artery and vein that provide blood cir-
culation to the arm. TOS is thought to be caused primarily by anatomical variations by the way the upper portion of the rib cage is constructed. This syndrome is typically diagnosed in people between 20 and 40 years of age, and is much more common in women. Normally, the first rib attaches to the first thoracic vertebra. The brachial plexus is derived from spinal nerves in the neck and cascades between the clavicle and first rib before entering the upper arm. Similarly, the subclavian artery and vein exit the chest cavity by looping over the first rib and following the plexus. Muscles, especially the anterior and middle scalenes and the trapezius, normally protect these structures without compressing them. However, incidences occur when individuals are born with an extra rib originating from the seventh cervical vertebra, which compresses the nerves or the vessels running over the first thoracic rib. Similarly, a fibrous band can originate from a cervical rib or vertebra and connect to the rib cage, causing compression. TOS can also be an acquired condition. Risk factors include occupations that require large amounts of overhead work and athletic activities that involve repetitive shoulder movement (especially swimming, weight lifting, and rowing). Musicians such as violinists and flutists may also be more susceptible. Poor posture can worsen symptoms as well. TOS is further classified into two main categories: neurogenic and vascular. Neurogenic TOS is more common and results when the brachial nerve plexus is compressed. Pain in the arm, especially while doing work with the arms or shoulders, is often the presenting symptom. Pain can also occur if patients turn their head or breathe deeply (both of which narrow the passage for the nerves and vessels). Muscle weakness in the shoulder, arm, and hand also result from plexus compression; atrophy of the hand muscles can be quite pronounced. In addition, patients may experience tingling or impaired sensation. In vascular TOS, symptoms are caused by compression of the subclavian artery or vein. Arterial compression starves the arm for oxygen, resulting in it becoming pale and cold. Venous compression causes accumulation of fluid and decreased flow into the arm as blood backs up. Occlusion can cause blood clots to form at the compressed locations; these clots can worsen the blockage or embolize downstream
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and lodge in smaller vessels. Arterial compression can also lead to aneurysm formation. Diagnosis of TOS is often very difficult due to the spectrum of symptoms and the lack of a definitive and accurate test. Physical examination is crucial; motor and sensory function of the arm and hand are carefully checked, and there are several positional tests that can reduce pulses at the wrist or cause a murmur over the neck if TOS is present. Radiographs are useful to identify cervical ribs, but they do not detect fibrous bands. Doppler ultrasound and magnetic resonance imaging (MRI) angiography are used to evaluate blood flow in suspected vascular TOS. Conduction tests of nerves in the arm and electromyography of the hand muscles can detect many cases of neurogenic TOS, although these tests have high rates of false-negative results and should not be used to rule out TOS. Complicating diagnosis is the fact that TOS closely mimics the symptoms of several other conditions, notably cervical vertebral disc disease and carpal tunnel syndrome. TOS can sometimes be relieved by avoiding activities that trigger symptoms, by losing excess upper body weight, and by physical therapy and exercise that strengthen the shoulder muscles and improve posture. However, surgery is often necessary to relieve the symptoms, either by correcting the abnormal anatomy (such as removal of a cervical rib) or by relieving pressure on the nerves and vessels (such as by dividing the anterior scalene muscle). Two surgical approaches to the thoracic outlet are commonly used. One is the supraclavicular approach in which the incision is made just superior to the clavicle to expose the anterior scalene muscle; this approach is useful in patients with compression of the upper brachial plexus, especially if a cervical rib is present. The other is the transaxillary approach, which is made by an incision in the armpit. Transaxillary operations are ideal for operating near the lower brachial plexus. Even after surgical correction, TOS can recur; ribs can regenerate to a degree and divided scalene muscles can reattach. SEE ALSO: Carpal Tunnel Syndrome; Cervical Spine; Or-
thopedist; Surgery.
BIBLIOGRAPHY. David Dawson, Mark Hallett, and Lew-
is Millender, Entrapment Neuropathies, 2nd ed. (Little, Brown, 1990); Jason Huang and Eric Zager, “Thoracic
1660 Thorn, George W. Outlet Syndrome,” Neurosurgery (v.55, 2004); Ghazi Rayan, “Thoracic Outlet Syndrome,” Journal of Shoulder and Elbow Surgery (v.7, 1998). David B. Bumpass Francis H. Shen, M.D. University of Virginia Dino Samartzis, D.Sc., M.Sc., Dip. EBHC Harvard University and Erasmus University
Thorn, George W. (1906–2004) Born on January 15, 1906, in Buffalo, New York, George W. Thorn is the endocrinologist who discovered cortisone as a treatment for Addison’s disease; bringing the first kidney dialysis machine to the United States; participating in the first successful kidney transplant in the 1950s; and serving as editor in chief of Harrison’s Principles of Internal Medicine, a well-respected medical resource. He persuaded Howard Hughes to fund medical research, which led to the founding of the Howard Hughes Medical Institute (HHMI). Thorn attended the College of Wooster in Ohio and then earned his M.D. at the University of Buffalo in 1929. For three decades, Thorn was the Chief of Medicine at the Peter Bent Brigham Hospital in Boston. He was selected as the Hersey Professor of Theory and Practice of Physick, the oldest medical chair in the country, at Harvard Medical School. He was granted 13 honorary degrees and has published more than 400 times. In the 1940s, Thorn became Howard Hughes’s medical adviser; after the founding of the HHMI, Thorn fulfilled positions at the Institute for more than 40 years, the last of which was Chairman Emeritus. In 1986, Thorn confided to the Washington Post that if he did not get an answer on something from Hughes within two weeks, he simply proceeded as he thought best. In 1993, The Whitaker Foundation, for which Thorn served as the chairman of the Scientific Advisory Committee, created the George W. Thorn Award to honor the most outstanding Whitaker researcher. The Whitaker Foundation also donates $10,000 to the recipient’s university’s research center. Thorn died of respiratory failure on June 26, 2004, in Beverly,
Massachusetts, at the age of 98. Predeceased by two wives, Doris Weston Thorn (d. 1984) and Claire Hyman Steinert Thorn (d. 1990), he was survived by his son, Weston, from his first marriage, and his two stepchildren, Susan and Alan, from his second marriage. He had two grandchildren, Nicholas and Tyler. Personal interests listed in his obituary included music (he played tenor banjo in a band to fund his education), horticulture, and travel, including traveling into active volcano interiors. SEE ALSO: Addison’s Disease; Kidney Failure and Dialysis;
Kidney Transplantation; Organ Transplantation.
BIBLIOGRAPHY. Howard Hughes Medical Institute, “In
Memoriam: George W. Thorn, 1906–2004,” www.hhmi. org/news/thorn_obit.html (cited June 2007); The Whitaker Foundation, “George Thorn, World-Renowned Physician and Close Advisor to the Foundation, Dies at 98,” http:// bluestream.wustl.edu/WhitakerArchives/news/thornobit. html (cited June 2007). Kelly Boyer Sagert Independent Scholar
Throat Disorders The human throat comprises a series of anatomic structures including the oropharynx, larynx, and upper portion of the esophagus. As the primary conduit for aerodigestive materials from the mouth to the stomach, the throat is a prime player in many human functions including breathing, swallowing, phonation, and digestion. The throat is a common site for infections of various etiologies. Furthermore, because proper throat function and mechanics are based upon the coordinated movement of a number of muscles, disorders of nerves leading to the throat and higher centers of the brain can and often do affect normal throat function. Infections of the Throat One of the more common infections of the throat is pharyngitis—inflammation of the pharynx often referred to as “strep throat.” This disorder is so named because one of the most likely causative agents is the
Streptococcus species of bacteria. The classic streptococcal infection includes the well-known symptom complex of fever and painful swallowing (odynophagia). Although the condition is usually self-limiting, the possibility exists for potential complications including peritonsillar abscesses, scarlet fever, and or kidney problems if the condition is not adequately treated. Sore throat or pharyngitis is also seen as a complication of infection with viruses including infectious mononucleosis caused by Epstein-Barr virus. Children are especially susceptible to viral infections of the throat including croup caused by parainfluenza virus and epiglotitis (inflammation of the epiglottis) caused by Haemophilus influenza. Although the incidence of epiglotitis is decreasing thanks to the widespread immunization against influenza, sporadic case reports are still mentioned in the literature and represent a pediatric airway emergency when they occur. Laryngitis is an irritation and swelling of the vocal folds (voice box apparatus) and the area around it. Other common infections of the throat include infections with fungi including Candida albicans in a condition known as thrush. Oral thrush can be seen in patients who take inhaled steroid medication for asthma or who have diabetes. Candidal infection can also involve the esophagus leading to inflammation (esopahagitis). Candida yeast, along with cytomegalovirus, and herpes simplex virus are common causes of esopahagitis in people who are immunocompromised such as people with HIV. Disorders of Phonation The throat houses the larynx or voice box and thus disorders of the throat may lead to difficulties with voice. A voice may be termed disordered or dysphonic when the vocal quality of an individual is altered/changed in such a way that it is thought to be abnormal to the listener. Degenerative neurologic disease, vocal abuse and misuse, growths of vocal folds, gastroesophageal reflux disease, and asthma may all contribute to abnormalities in vocal cord function in the throat. Disorders of phonation may be the result of abnormal growths of tissue on the vocal cords, for example, vocal polyps. Vocal polyps are soft fluid filled growths that arise on the front portion of the vocal fold often brought on by vocal abuse (excessive shouting or singing) and manifest as hoarseness of voice. Persistent and progressive hoarseness coupled with other constitutional symp-
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toms such as fatigue, fevers, and or weight loss may signal serious disease involving the throat and evaluation by an otolaryngologist is warranted. Disorders of Swallowing The act of swallowing occurs in several phases. During the oral phase, a prepared bolus of food is propelled from the oral cavity into the pharynx while the airway inlet is protected. This coordinated movement requires sophisticated neural input, using special sensory cells throughout the throat as well as higher brain centers. Abnormalities with signaling can lead to difficulty swallowing (dysphagia). This sensation should be differentiated from a feeling of a “lump in the throat” (globus sensation). Globus sensation can be caused goiters (growth of adjacent thyroid gland tissue), anxiety or panic attacks, and/or gastroesophageal reflux. Dysphagia is commonly categorized as either esophageal or oropharyngeal. Esophageal dysphagia is often associated with chest pain and regurgitation of food and often arises from esophageal-specific diseases such as esophageal cancer or achalasia (inability
Throat X-ray: Disorders of nerves leading to the throat and higher centers of the brain can affect normal throat function.
1662 Thymus Cancer of the lower esophagus to relax and allow passage of ingested food). Oropharyngeal dysphagia more typically involves the structures of the throat, and along with difficulty swallowing, weakness and cough may be present. Oropharyngeal dysphagia is most commonly caused by neuromuscular disorders (the most common of which is stroke); another cause is Parkinson’s disease. Oropharyngeal dysphagia can also be caused by structural causes of which cancer is the most worrisome. Advances are being made in the field of swallow evaluation and many hospitals around the country have a dedicated swallow evaluation team. A newer advancement in evaluation of swallowing and throat disorders is the development of flexible endoscopes to allow direct visualization of the hypopharynx and larynx. Such tests are able to assess a person’s ability to protect their airway on food ingestion, as passage of food into the larynx (aspiration) rather than esophagus can lead to serious lung problems. A number of imaging modalities are available to evaluate the anatomy of the throat and surrounding tissues. Computed tomography of the neck can delineate abnormalities in the pharynx and also identify surrounding soft tissue masses that may be compressing the throat or affecting its function. Esophogastrogduodenoscopy (EGD) is a procedure performed by a trained gastroenterologist; it allows for visual identification of mucosal lining of the esophagus. SEE ALSO: Dysphagia; Larynx; Pharyngitis; Pharynx. BIBLIOGRAPHY. D.E. Bank and S.E. Krug, “New Ap-
proaches to Upper Airway Disease,” Emergency Medicine Clinics of North America (v.13/2, 1995); A.L. Bisno, “Acute Pharyngitis: Etiology and Diagnosis,” Pediatrics (v.97/6, 1996); A.L. Bisno, et al., “Diagnosis and Management of Group A Streptococcal Pharyngitis: A Practice Guideline,” Clinical Infectious Diseases (v.25/3, 1997); J.L. Blumer and J. Goldfarb, “Meta-Analysis in the Evaluation of Treatment for Streptococcal Pharyngitis: A Review,” Clinical Therapeutics (v.16/4, 1994); J.A. Logemann, Evaluation and Treatment of Swallowing Disorders, 2nd ed. (Pro-Ed, 1998); G. Mann, et al., “Swallowing Function after Stroke: Prognosis and Prognostic Factors at 6 months,” Stroke (v.30/4, 1999); L.L. Mann and K. Wong, “Development of an Objective Method for Assessing Viscosity of Formulated Foods and Beverages for the Dys-
phagic Diet,” Journal of the American Dietetic Association (v.96/6, 1996); S.F. Noll, et al., “Rehabilitation of Patients with Swallowing Disorders,” Physical Medicine and Rehabilitation (Saunders, 1996); I.R. Odderson, et al., “Swallow Management in Patients on an Acute Stroke Pathway: Quality Is Cost Effective,” Archives of Physical Medicine and Rehabilitation (v.76/12, 1995). Anil Seetharam, M.D. Washington University in St. Louis
Thymus Cancer The thymus is a gland located in the upper part of the chest. It plays a significant role in the immune system of the body. The thymus plays an important role in the development of the immune system from prenatal to puberty. From about the twelfth week of gestation it grows until puberty. However, with the onset of public hormonal changes it begins to shrink. Situated the upper anterior portion of the chest cavity the thymus is situated behind the breastbone (sternum) next to the lungs. the thymus has two lobes that join in front of the trachea. The two lobes are composed of lymphatic tissues which are tightly packed together. The tissues are fat, epithelium and lymphocytes. The thymus releases hormones that stimulate the production of infection fighting T-cells. The lymphocytes become T cells when the body is infected with a virus. The T cells are an important part of the body’s immune defenses against viruses. If the thymus does not develop normally in children it can contribute to immodeficiency disorders. In earlier medical history the thymus was dismissed as an evolutionary relict like the appendix. It was viewed as merely a graveyard for lymphocyte cells. However, experiments conducted by Jacques Miller demonstrated the importance of the cells. He removed the thymus from three day old mice. These were later observed to be deficient in T cell production. Lymphocytes from bone-marrow become thymocytes in the two thymic lobes. They eventually mature into T cells. After becoming T cells they leave the thymus can become the peripheral T cell reservoir. They are then able to direct many aspects of
Thymus Cancer
the adaptive immune system. If the thymus is lost at an early age from injury, illness or genetic mal-mutation creates an immune deficiency condition that renders the body very susceptible to infections. The T cell receptor enables it to recognize antigens as foreign to the body. During the T cell maturation process T cell receptor sites under go genetic organization that enables each to become specialized as unique receptors. This makes sets of T cells able to be able to have peptide (MHC) receptor site combinations. It also has the ability to recognize other T cells and to avoid treating them as antigens. The thymic epithelial cells develop differently from the lymphoid thymocytes. They begin in the form of endodermal diverticula which are two flask-shaped pouches. As they eventually meet to grow together as connective tissue. About ninety percent of thymic cancers are thymomas. The remaining types are thymic carcinomas, lymphomas, or carcinoid tumors. Occurrences of thymomas are rare. There are only about five hundred to seven hundred cases diagnosed in the United States each year. It is much more common is middle aged and the elderly regardless of gender. Thymomas cancer is cancer of the thymic epithelial cells. Patients with myasthenia gravis have this from of cancer in from twenty-five to fifty percent of cases. Symptoms of thymomas cancer usually appear to be bronchitis because the tumor(s) presses against the cough nerve. Thymomas tumors may grow in a range from slowly to rapidly. In some cases the thymomas is benign but these have the strong possibility of become cancerous. Those that grow rapidly may spread to surrounding tissue. Treatment of thymomas usually requires the removal of the thymus gland. Tumors that originate in the thymocytes form thymic lymphomas. Besides coughs the cancer may also present symptoms such as shortness of breath, blood flow problems with the heart, fatigue, poor appetite, hives, night sweats and fever, or weight loss. Hodgkin’s Disease affects the lymphatic system. It may originate in the thymus even in childhood. NonHodgkin’s Disease (NHD) lymphoma of the thymus the lymphocytes become cancerous. Lymphocytes, which are white blood cells that collect in the lymph nodes, may also present themselves as a form of leu-
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kemia. The development of thymic lymphomas may be associated with the Epstein-Barr virus. Thymic cancer is described and treated according to its stage of development. In Stage I thymomas the cancer is removed surgically. Survival usually occurs in most cases. Unless complete removal is not possible then radiation is not used in this stage. In stages II, III, IV thymomas the thymus is surgically removed as is any other tissue to which the cancer has spread. In the III and IV stages the tumor may have wrapped around the aorta or major veins. These tumors are usually treated with radiation therapy after all possible surgical removal of the cancer has been accomplished. If the thymomas can not be completely removed the thymomas can be treated with chemotherapy or chemotherapy and radiation. In some cases chemotherapy is used to shrink the tumor to increase the amount that can be removed with surgery. Octreotied has been successfully used to treat thymomas. It replaces somatostatin at binding sites which causes the thymomas to stop growing or to die. The use of prednisone in combination with octreotide may increase the effectiveness of the treatment. In cases of reoccurring thymomas the treatment will usually be some further surgical removal, chemotherapy or possible some radiation in combination with chemotherapy. In the treatment of cancers thymosin alpha 1, a chemical produced naturally by the thymus has been used to improve the immune system. The SciClone Company is the patent holder that has licensed a number of countries to produce it. Another chemical produced by the thymus gland is thymosine beta 4 (thmostimuline) is also being tested. See Also: Cancer (General); Chemotherapy; Hodgkin’s
Lymphoma.
BIBLIOGRAPHY. Kyriakos Anastansiadis and Chandi Rath-
natunga. eds. Thymus Gland and Its Surgery (SpringerVerlag, 2007); Marion D. Kendall and Mary A. Ritter. Thymus in Immunotoxicology, Vol. 4 (Taylor & Francis, 1991); Michael J. Kornstein and Georgean G. DeBlois. Pathology of the Thymus and Mediastrinum, Vol. 33 (Elsevier Health Sciences, 1995); Alexander Mars. Epithelial Tumors of the Thymus: Pathology, Biology and Treatment (Springer-Verlag, 1997); William D. Travis, ed., et al., Pathology
1664 Thyroid Cancer and Genetics of Tumours of the Lung, Pleura, Thymus and Heart (World Health Organization, 2004). Andrew J. Waskey Dalton State College
Thyroid Cancer The thyroid is a large bow-tie shaped endocrine gland that is found in the human body just below the Adam’s apple. The thyroid acts as a cybernetic agent in the human body by steering the rate at which calories are burned. It controls the making of proteins by the body and the sensitivity of the body to hormones. It does not operate independently but is controlled by the pituitary gland and the hypothalamus gland. To carry out its functions the thyroid manufactures a number of thyroid hormones including thyroxine, triiodothyronine (T3), calcitonin. The hormone thyroxine (T4) regulates the metabolic rate in the body. It also affects the growth and the function of other systems in the body. Triiodothyronine works with thyroxine to affect metabolic rates as well as growth rates in the body. The thyroid uses iodine to manufacture both thyroxine and triiodothyronine. Without sufficient quantities of iodine the body will develop goiter and have other serious health consequences. Sea salt is a vital source of iodine. It is also found in fish. People living in area remote from the sea have often had goiter. However iodine is easily added to table salt. The Kiwanis Club International has underway a service project to eliminate goiter by building iodinated salt factories around the world whereever they are needed. Thyroid disorders include hyperthyroidism, hypothyroidism, Graves disease (called Basedow’s disease or Graves-Basedow disease in parts of Europe), and other disorders. Hyperthyroidism is a condition popularly called an overactive thyroid. It is caused by the over production of thyroid hormones. The overproduction causes excessive metabolism which increases the temperature and the speed of the biochemistry of the body. The underproduction of thyroid hormones by the thyroid gland is called hypothyroidism. It is relative-
ly common in people over sixty years of age in the Northern Hemisphere. Its symptoms are varied but usually are presented as a variety of impaired psychological or physiological functions. Cancer is another of the diseases of the thyroid gland. There are four major types of thyroid cancer. The follicular, medullary and anaplastic forms of thyroid cancers are histological types. The most common type is papillary carcinoma. It seems to be associated strongly with radiation. It usually arises as an irregular solid or cystic mass inside of normal thyroid tissue. It is usually curable with a ten year survival rate in over eighty percent of cases. If it metastasizes it spreads to the lymph nodes in the neck as cervical metastasis. This expansion of the area of the disease is treatable but often reoccurs and has to be treated again. The reoccurrence of the cervical metastasis does not increase the mortality rate. Papillary carcinoma does not usually spread; however, in cases where it does spread the prognosis is guarded. The most common site for the spread of papillary carcinoma beyond the thyroid and the cervical lymph nodes is to the lung or to bone. Follicular carcinoma is much more malignant than papillary carcinoma. It often metastasizes with serious consequences if the invasion is vascular with resulting spread to the lungs, bone, brain, liver bladder and skin. It usually occurs in people between 40 and 60 years of age. The prognosis is directly related to the tumor size. The disease has been associated with radiation exposure only rarely. Women are much more likely to get it than are men. It can be cured with radiation therapy. The younger the patient the better is the general results for the patient with a cure rate of 95 percent. Medullary cancer of the thyroid gland develops in the thyroid hormone producing cells. The parafollicular cells are called C cells. They make different hormones including calcitonin which is the source of the name for C cells. This type of cancer is less well defined but it also has high cure rates although it is usually confined to the thyroid gland. Tumors are produce by medullary cancer. Metastasis occurs late but the metastasis can be to the liver, brain, bone or to the andrenal medulla. There does not seem to be any connection with this type of cancer and radiation exposure. The fourth form of thyroid cancer is also the rarest. Anaplastic thyroid cancer is rare but an aggres-
sive and deadly form of cancer. This form of cancer makes up between 1 to 5 percent of the thyroid cancers diagnoses in the United States each year. On average there will be about 23,000 new cases each year with about 1500 deaths with slightly more women dying of the disease than men. It is one of the few cancers that are increasing. The symptoms of anaplastic cancer include a rapidly growing mass in the neck, hoarseness with voice changes, coughing, coughing blood, and difficulty swallowing. Treatment is usually with surgery to remove the tumor. Therapeutic radiation usually follows. Unfortunate the anaplastic tumor usually attaches itself to vital parts of the neck or it infiltrates the trachea which makes it inoperable. Anaplastic tumors do not usually respond to chemotherapy. Most patients do not survive beyond six months. The late Chief Justice of the United States Supreme Court, William Rehnquist was a victim of anaplastic thyroid cancer. Since 1973 thyroid cancer has increased in the United States by over 200 percent. However the increases have been almost exclusive in the papillary thyroid cancer type and not in the less common histological types of follicular, medullary and anaplastic cancers. Morality has been stable because of improve treatments. It is also believed that the increases is due to better and earlier detection rather than to an increase in the incidence of the disease There are about 20,000 new cases of thyroid cancer each year in the United States. Females are more likely to have thyroid cancer at a ratio of three to one. Thyroid cancer can occur in any age group, although it is most common after age 30 and its aggressiveness increases significantly in older patients. Symptoms begin with the presence of a nodule on the thyroid discovered by examination by a physician. Symptoms of thyroid cancer include hoarseness, neck pain, and enlarged lymph nodes. Most people as they advance in age develop one or more nodules on their thyroid gland. However, only about 1 percent of these turn cancerous. Globally thyroid cancer rates are high in developed countries such as Australia, Japan, Norway, New Zealand and Canada. However, rates are also high in Central America, but only among women. Of all cancer deaths thyroid cancer accounts for only a small percentage of cancer deaths.
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See Also: Cancer (General); Endocrine Disease (Gener-
al); Hormones; Radiation Exposure.
BIBLIOGRAPHY. Kenneth Ain, and M. Sara Rosenthal,
The Complete Thyroid Book (McGraw-Hill, 2005); Robert J. Amdur, Essentials of Thyroid Cancer Management (Springer-Verlag, 2005); H. J. Biersack, and F. Grunwald, eds., Thyroid Cancer (Springer-Verlag, 2005); Theodore Friedman and Winnie Yu. The Everything Health Guide to Thyroid Disease: Professional Advice on Getting the Right Diagnosis, Managing Your Symptoms, and Feeling Great (Adams Media Corporation, 2006); Douglas Van Nostrand, ed., et al., Thyroid Cancer: A Patient’s Guide (Keystone Press, 2004); Leonard Wartofsky. Thyroid Cancer (Springer-Verlag, 2005). Andrew J. Waskey Dalton State College
Thyroid Diseases Thyroid diseases are a class of diseases resulting from dysfunction of the thyroid, an important endocrine gland. The principal function of the thyroid, a double-lobed structure located in the neck, is to produce the hormones thyroxine (T4) and triiodothyronine (T3), which regulate growth and metabolism in the body. Calcitonin is an additional hormone produced by the thyroid that helps regulate calcium levels in the blood. Diseases of the thyroid affect approximately 200 million people throughout the world, with the majority of those affected being women. The most common problems of the thyroid gland are hyperthyroidism, resulting from an overactive thyroid, and hypothyroidism, due to an underactive or nonfunctional thyroid. It is estimated that women are five to eight times more likely than men to suffer from hypothyroidism. In addition, incidence of hypothyroidism increases with age, such that about 17 percent of women and nine percent of men by age 60 have an underactive thyroid. Hypothyroidism is characterized by fatigue, coarse skin and hair, weight gain, depression and mood swings. At the other extreme, common symptoms of hyperthyroidism include heat intolerance, weight loss, sleep disturbances, thyroid enlargement
1666 Thyroid Diseases and tremors. If left untreated, thyroid disease is associated with elevated cholesterol levels and subsequent heart disease, infertility, muscle weakness, osteoporosis and even coma or death. Thyroid regulation The pituitary gland is the master regulator of thyroid function, producing thyroid-stimulating hormone (TSH), which stimulates the thyroid to produce T4 and T3. The hypothalamus, in turn, controls pituitary function by secreting thyroid-releasing hormone (TRH), which initiates TSH production and subsequent thyroid hormone formation. Normal thyroid function is governed by a tightly regulated feedback mechanism, whereby low levels of T3 and T4 signal to the pituitary to produce more TSH and to the thyroid to make more thyroid hormones. Conversely, excess levels of these hormones normally signal the pituitary and thyroid glands to decrease their production, so that levels of thyroid hormones remain adequate and not in excess. Most thyroid diseases are the result of dysfunction within this elaborate regulatory mechanism, such that inappropriate levels of thyroid hormones are produced, thereby disrupting normal growth, metabolism and function in the body. In addition, thyroid hormone production requires adequate dietary intake of iodine. As a result, iodine deficiency is the most common underlying cause of thyroid disorders globally, with an estimated two billion individuals including 285.4 million children classified as iodine deficient by a WHO 2004 report. Hypothyroidism Hypothyroidism arises when there are inadequate levels of thyroid hormone available to ensure normal growth, metabolism and tissue function. It is the most common of thyroid diseases, preferentially affecting women, the elderly, and those with a family history of thyroid disease. Characterized largely by nonspecific clinical symptoms—including fatigue, mental depression, intolerance to cold, slight weight gain, dry skin and hair, and constipation—the diagnosis of hypothyroidism can be easily confirmed by thyroid function tests. These tests examine blood levels of TSH, T3 and T4, where low levels of T3 and T4 are diagnostic of hypothyroidism. The most common cause of hypothyroidism is Hashimoto’s disease, an autoimmune condition where the immune system attacks the thyroid gland, impair-
ing its function. Other causes of hypothyroidism include iodine deficiency, treatment with radioactive iodine, or surgical removal of the thyroid gland (the latter two often done in the treatment of other thyroid disorders) as well as adverse consequences of certain medications, such as amiodarone. Hypothyroidism can also result from disruption at various stages of the hypothalamic-pituitary-thyroid axis that governs thyroid hormone production. Different patterns of thyroid function test results will reveal whether a patient is suffering from primary hypothyroidism that is the result of dysfunction at the thyroid gland level, secondary hypothyroidism that is indicative of dysfunction within the pituitary, or tertiary hypothyroidism which suggests dysfunction at or above the level of the hypothalamus. Secondary and tertiary hypothyroidism are relatively rare causes of hypothyroidism. The treatment of hypothyroidism consists of thyroid hormone supplementation. Synthetic forms of T4, which function identically to natural T4 in the body, are prescribed, and this replacement hormone is usually needed indefinitely. Periodic thyroid function tests are performed to ensure that there are appropriate levels of thyroid hormones in the body, and dose adjustments are made accordingly. Hyperthyroidism Hyperthyroidism, characterized by an overactive thyroid gland leading to excessive T4 production, can result from multiple causes, of which the most common is Graves’ disease. Graves’, a chronic disease that typically runs in families with a history of thyroid disease, occurs when the body’s immune system attacks the thyroid gland, causing the gland to enlarge and become hyper-functional. Other causes of hyperthyroidism include thyroid nodules, thyroiditis (painful inflammation of the thyroid, typically of viral etiology), and thyroiditis associated with pregnancy. Diagnosis is made by physical examination and measurement of thyroid hormone levels in blood. Common symptoms indicative of hyperthyroidism are insomnia, increased bowel movements, fatigue, palpitations, tremors, weight loss, nervousness and heat intolerance. There are several treatment options, including anti-thyroid medications which lower the amount of hormone produced by the gland, radioactive iodine, which results in permanent destruction of the thyroid and necessitates subsequent thyroid
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hormone supplementation, surgical removal of the thyroid, or beta-blockers, which relieve some of the associated clinical symptoms.
nearby structures such as the esophagus or trachea. Occasionally, excess thyroid tissue can also contribute to hyperthyroidism.
Iodine deficiency disorders Iodine is a critical component of thyroid hormones T3 and T4, and as such, its deficiency imposes severe consequences on individuals and populations globally. It is obtained only through the diet. Inadequate dietary intake leads to inadequate thyroid hormone production, spawning a range of consequences as a result of this associated hypothyroidism, including goiter formation, cretinism and increased neonatal and infant mortality. A goiter, or enlargement of the thyroid gland, is a classic manifestation of iodine deficiency. Goiter formation results from excess stimulation of thyroid growth by increased levels of TSH secreted in an attempt to restore T4 and T3 levels to normal. Iodinedeficiency goiters can become large enough to cause compression of trachea or esophagus, or delay discovery of coexisting thyroid cancer. Adults with iodine deficiency have usual symptoms of hypothyroidism and a goiter. However, for a developing fetus or infant, iodine deficiency and associated hypothyroidism can be devastating. Thyroid hormone is essential for normal development of the central nervous system, and inadequate hormone levels can lead to varying degrees of mental retardation. Mental retardation, accompanied by other neurologic and somatic defects, including gait disturbances and short stature, is a relatively rare form of congenital hypothyroidism—that is, hypothyroidism present at birth—known as cretinism. Iodine deficiency is also associated with increased neonatal and infant mortality, and correction of this deficiency early in life can reverse all of these effects.
Thyroid Cancer Thyroid cancer is classified into roughly four main types on the basis of the histological appearance of the cancer: papillary, follicular, medullary, and anaplastic. Symptoms associated with thyroid cancer include a new thyroid nodule with or without associated symptoms, an enlarged lymph node, or throat pain. Ultrasound is usually employed in screening these nodules: hypoechoic nodules (dark-appearing structures on ultrasound), irregular borders and microcalcifications (tiny calcium deposits in the nodule) are suspicious of cancer. Blood tests are employed to screen for elevated TSH (indicating an active thyroid nodule, which is less likely to be malignant) or anti-thyroid antibodies (which may indicate a nodular goiter due to Hashimoto’s thyroiditis). If these tests are negative, fine needle aspiration (FNA), involving the removal of a small piece of tissue, of the nodule is usually performed, and diagnosis is made based on the appearance of the recovered cells. In some cases, radioactive iodine uptake scans are performed—a nodule with increased iodine uptake in a patient with clinically low TSH is highly indicative of cancer. The most common form of thyroid cancer is papillary (75 percent), followed by follicular (16 percent), medullary (5 to 7 percent), and anaplastic (3 percent). Papillary and follicular are known to be slow-growing cancers that have a moderate chance of recurrence post-treatment, but patients under age 45 are usually at low risk of death due to the slow growth. Medullary cancers that have not metastasized also have a good prognosis although once metastasis has occurred (most commonly to the liver) prognosis can be significantly worsened. Treatment for papillary, follicular and medullary cancer is almost always surgical resection of the cancer, followed by radioiodine therapy for follicular and papillary cancer. Anaplastic cancer has the worst prognosis due to its high rate of metastasis; surgical resection is not curative and is usually followed by external beam radiation therapy, with median survival of three to seven months from diagnosis.
Thyroid nodules Excess growth of normal thyroid tissue or the development of a fluid cyst can lead to the formation of thyroid nodules, a fairly common condition present in roughly six percent of all women and two percent of all men. It is unknown why normal thyroid tissue sometimes grows into nodules. The great majority of these nodules are noncanceorus, but approximately five percent of nodules are indeed malignant growths that can spread and metastasize. Even benign thyroid nodules can sometimes cause symptoms by growing large enough to impinge upon
SEE ALSO: Endocrine Disease (General); Head and Neck
Cancer; Parathyroid Diseases.
1668 Tick Bites BIBLIOGRAPHY. Jan Liska, et al., “Thyroid carcinoma,”
Curr Opinions in Oncology (v.18/1, 2006). B.S. Hetzel, “Iodine deficiency disorders (IDD) and their eradication,” Lancet (v.12/2, 1983); World Health Organization, “Iodine status worldwide,” WHO Global Database on Iodine Deficiency, (World Health Organization, 2004).
Charitha Gowda Deipanjan Nandi Duke University School of Medicine
Tick Bites A tick bite is the resulting injury from a tick sting, which could produce a local inflammatory reaction, a systemic toxemia, or after an incubation period, a tick-borne disease such as those caused by virus, rickettsias, bacteria, and protozoans. Ticks are hematophagic arthropods and bite humans and/or animals to obtain blood. From an epidemiological point of view, it is important to mention that in some countries (particularly in northern and developed countries) more vectorborne diseases are transmitted by ticks than by any other agent. During the past 30 years, tick-borne diseases have taken on increased importance as humans (in many cases with their pets) have moved into rural areas and increased their recreational outdoor activity, thus being more frequently exposed to tick bites. Taxonomically, medically important ticks belong to the class Arachnida, order Acarina and suborder Ixodes with two families: Argasidae (with the genuses Argas, Otobius, and Ornithodoros) and Ixodidae (with the genuses Amblyomma, Dermacentor, Boophilus, Ixodes, Rhipicephalus, and Haemophysalis). Most important ticks belong to the last family, being responsible of transmission of diseases such as Rocky Mountain spotted fever, Q fever, boutonneuse fever, ehrlichiosis, tularemia, Colorado tick fever, Queensland tick typhus, Siberian tick typhus, tularemia, Central European tick-borne encephalitis, Congo-Crimean fever, tick-borne relapsing fever, babesiosis, and Lyme disease, among others. As blood feeders, ticks can be a nuisance; their bites can cause irritation and, in the case of some ticks, paralysis. The prevention of tick bites and the prompt detection and removal of attached ticks can reduce the
It is important for physicians to consider the illnesses associated with tick bites when patients present with influenza-like symptoms.
chances of infection. To limit the chance of getting a tick bite, it is recommended to avoid tick-infested areas when possible and avoid shortcuts through heavily wooded, tick-infested areas. Use caution when entering tick-infected areas by staying in the center of paths, avoiding sitting on the ground, and conducting frequent tick checks. Additionally, it is also advisable to dress properly by wearing light-colored clothing. The use of repellents is also important in preventing tick bites. The primary active ingredient in most repellents today is DEET (N,N-diethyl-3-methylbenzamide or N,N-diethyl-m-toluamide), which repels ticks and decreases the chance of bites (depending upon the concentration). Other repellent commonly used to prevent bites is permethrin (used frequently for the application on clothing or nets). It is important for physicians to consider the illnesses associated with tick bites when patients present with influenza-like symptoms. A petechial rash initially affecting the palms and soles of the feet is associated with Rocky Mountain spotted fever, whereas erythema migrans is associated with Lyme disease.
Tinnitus
Moreover, ticks can cause important dermatologic disease directly by their bite, which also require specialized medical attention. SEE ALSO: Flea Bites; Hemorrhagic Fever; Lyme Disease;
Medical Entomology; Parasitic Diseases.
BIBLIOGRAPHY. Paul Beaver, et al., Clinical Parasitology
(Lea & Febiger, 1984); Robert Bratton and Ralph Corey, “Tick-Borne Disease,” American Family Physician (v.71/12, 2005); Gordon Cook and Alimuddin Zulma, Manson’s Tropical Diseases (Saunders, 2003); Pablo Cova, General Principles of Entomology (FVSE, 1974); Becerri Flores and Romero Cabello, Medical Parasitology (McGraw-Hill, 2004); David Heymann, Control of Communicable Diseases in Man (APHA/PAHO/WHO, 2004); Daniel McGinleySmith and Sandy Tsao, “Dermatoses from Ticks,” Journal of the American Academy of Dermatology (v.49/3, 2003). Alfonso J. Rodriguez-Morales, M.D., M.Sc. Universidad de Los Andes Carlos Franco-Paredes, M.D., M.P.H. Emory University
Tinnitus Tinnitus is the perception of an abnormal sensation of sound in the ear or head in the absence of acoustic stimulation from external environment, from within body, due to hallucinations or due to mental illness. Spontaneous tinnitus is a significant interdisciplinary therapeutic problem; it is a common condition affecting around one in 10 of the population at any given time. For the majority of people, it is an annoyance rather than a major health issue; however, for approximately 0.5 percent of the population, tinnitus interferes with their ability to pursue a normal life. The effects of tinnitus are vast; some degree of hearing loss is found in the vast majority of tinnitus patients. In elderly patients, it most frequently coexists with sensorineural hearing loss. Tinnitus is also likely to disrupt cognitive functioning. Tinnitus is divided into two parts: objective and subjective. Objective tinnitus is caused by sounds generated in the body, while subjective tinnitus is caused by abnormal neural activity that is not evoked by sound. Tinnitus
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may present with symptoms of hyperacusis (condition characterized by oversensitivity to certain frequency ranges of sound). Tinnitus is a common symptom in otosclerosis patients; affective disorders, such as phonophobia (morbid fear of sound including ones own voice), and depression which may accompany severe tinnitus. Tinnitus is thought to be caused by abnormal neural activity, with possible involvement of the nonclassical ascending (extralemniscal, diffuse, or polysensory) auditory pathway that bypass the primary auditory cerebral cortex and provide subcortical connections to limbic structures (e.g., amygdala) among others. Pathogenesis of tinnitus is related to the ear, functional changes in the central auditory system, and perhaps the peripheral auditory system. The most probable place generating tinnitus in the auditory pathway is outer hair cells (OHC) inside the cochlea. There appears to be a loss of OHC although inner hair cells are intact. The changes in the central nervous system are induced through expression of neural plasticity, some of which may have been caused initially by abnormalities in the ear or the auditory nerve. The diagnostic approach in children and adolescents includes hearing tests such as pure-tone audiometry which determines hearing sensitivity and speech audiometry which is a functional test of earspecific speech discrimination performance. There is currently no cure for tinnitus; however, there are several treatment strategies that can alleviate the symptoms in some patients. Tinnitus of predominantly central origin has been treated successfully with benzodiazepines (although long-term use is not recommended) and GABAergic drugs such as gabapentin. Many studies advocate the use of hyperbaric oxygen (HBO2) therapy for the treatment for tinnitus. Other studies suggest that the therapeutic effects of HBO2 on tinnitus might be merely due to psychological mechanisms triggered by the attitude of the patient toward HBO2 therapy prior to the treatment. Fitting with hearing aids is an effective way of treatment in the majority of elderly patients with chronic tinnitus. Suppression of tinnitus by electrical stimulation via a cochlear implant has been studied in recent years. Some individuals who undergo cochlear implant surgery report total or partial relief of the symptoms even in the contralateral ear. Tinnitus patients may seek treatment with acupuncture, although this has not been demonstrated to be
1670 Togo efficacious as a treatment for tinnitus. Proposed mechanisms by which antidepressants might be helpful for tinnitus, including treatment of comorbid depression and anxiety have been studied. In cases with severe annoyance, tinnitus counseling is sufficient therapy. Although the overall prognosis of tinnitus is good, it does have an insidious onset, may continue for decades, cause disruption of sleep patterns, and lead to depression. SEE ALSO: Ear Disorders; Otology. BIBLIOGRAPHY. B.C.J. Moore, J. Ashmore, and M. Hagard,
New Developments in Hearing and Balance (Oxford University Press, 2002).
Farhana Akter King’s College, London
Togo This West African country was ruled by the Germans as a protectorate from 1884 until 1914, as the German colony of Togoland. In 1914, at the start of World War I, it was taken by a joint Anglo-French force and the territory was split with the western part becoming part of the Gold Coast (now Ghana), and the remainder becoming the French colony of Togo. It gained its independence on April 27, 1960 as the Republic of Togo, and has a population of 6,100,000 (2005), and has 7.6 doctors and 30 nurses per 100,000 people. During the period of German colonial rule, healthcare services in Togo were extremely rudimentary, even for the European population. The doctors in the health service all reported directly to the governor, working independently of each other. As the Germans wanted Togo to be a “showcase” example of colonialism, they had built four hospitals, at Anecho, Misahohe, Palime and Lomé – the latter having been only just completed when World War I broke out. In addition there was a mobile dispensary run by a doctor who worked from Sokode. The Germans had also made a large impact on reducing the prevalence of sleeping sickness. In 1938 the hospital at Lomé was the main one for the whole of Togo, with nine minor hospitals, 32 medical posts and six maternity clinics. The medical staff included 16 Europeans, of whom 13 were quali-
fied doctors; and also 13 African doctors who had been trained at Dakar, Senegal, and 310 subordinate personnel, which included nurses and midwives. Statistics for 1938 showed that they had treated 54 European and 6,004 African inpatients, and 989 European and 685,071 African outpatients. Although the Germans had done much to try to eliminate sleeping sickness, the French had to continue the program, using mobile teams. By 1939 leprosy was still a major problem with about 14,000 lepers in the country, sufferers being limited, by an order of 25 January 1939, to live in particular areas. After independence, there was an increase in money spent on the entire health system in the country, with attempts to train more local doctors. Of the many medical complaints treated by doctors in Togo, malaria, liver cancer and skin cancer for male patients, are all relatively common. Goiter is also common in some parts of the country. To try to reduce the cost of medicines, pharmacies in the country were nationalized. However the national pharmaceutical company went bankrupt, putting pharmacies back into the private sector. There are now doctors trained in Togo, mainly at the Faculty of Medical and Biological Sciences at the Université du Benin. The Institut National de Recherche Scientifique (I.N.R.S.: National Institute for Scientific Research), Lomé, is affiliated with the Ministry of Education and is the official medical research center in the country. SEE ALSO: Diabities; Goiter; Liver Cancer; Malaria. BIBLIOGRAPHY. Ezekiel Kalipeni & Philip Thiuri, Issues
and Perspectives on Health Care in Contemporary Sub-Saharan Africa (Edwin Mellen Press, 1997).
Justin Corfield Geelong Grammar School, Australia
Tonga Named “The Friendly Islands” by Captain James Cook when he landed in the 1700s, Tonga is the Pacific Islands’ only monarchy and the only nation that never fully lost its indigenous control of the government.
The 500-mile long archipelago is located due west of Samoa and consists of 169 islands, 96 of which are inhabited. The total landmass is around 465 square miles, about four times the size of Washington, D.C. The total population is about 115,000 with a growth rate of 2 percent annually. This is due mainly to a high birth rate, with 25.37 births per 1,000 people and a fertility rate of 3.8 children per woman. The death rate is 5.28 per 1,000 people. Population density is high at 157 people per square kilometers, with 70 percent of the population living on the largest island, Tongatapu. Thirty-three percent of Tongans live in urban areas. Tonga has made great strides in combating poverty since the 1950s. Four percent of Tongans live in extreme poverty with under 7 percent unable to meet basic food needs. Tourism and agricultural exports are the nation’s main sources of income; however, the economy is not robust, with an estimated 55 percent of the Gross Domestic Product coming in the form remittances from those working outside the islands. The health profile of Tonga has improved greatly in the last 50 years. Life expectancy at birth is currently 70 years for males and 72 years for females. Tonga has the lowest rates of infant and child mortality in the Pacific region; maternal mortality is also very rare. Childhood immunization rates better in some areas than in industrialized countries. Common infectious diseases have been largely eradicated. Dengue fever reemerged in 2003 but is believed to have little chance of becoming endemic. The government completed a program to eliminate lymphatic filariasis in 2005. The last indigenous case of leprosy was diagnosed in 1998. There were 12 cases of tuberculosis diagnosed in 2004. As on other Pacific Islands, the AIDS rate is low, with just 14 confirmed cases of HIV since 1990. The rate of other sexually transmitted diseases is not really known because of poor reporting. Poor sanitation contributes to endemic levels of hepatitis B, and there are about 20 cases of typhoid fever diagnosed each year. In 2005, there was a widespread outbreak of watery diarrhea which killed six children. The main health problem facing Tongans today is obesity. A 2004 study found that in the last 30 years, the average weight of a Tongan male has climbed from 172.1 pounds to 210.5 pounds, and the average female’s weight grew from 162.8 pounds to 209 pounds. Sixty percent of the population is obese, and
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weight gain is now starting in adolescence. The causes are due primarily to the quantity and quality of food within the context of Tongan society. One study shows that the average Tongan male eats twice the amount of food as the average Australian man; feasting holds an important place in island culture. However, traditional foods have been supplanted by a westernized diet high in fat, sugar, and salt. Rate of diabetes and heart disease are climbing as a result. Tongans seem to have a genetic predisposition toward glucose intolerance, making them more susceptible toward developing diabetes. The rate of type 2 diabetes among adults is 18 percent, more than double what it was in the 1970s. One survey cited by the World Health Organization shows that about 80 percent of people with diabetes are untested and, therefore, untreated. The Ministry of Health is one of the country’s biggest employers, with 925 staff posts in 2005. Most doctors work for the government on at least a parttime basis. Government expenditures on healthcare are $50 per capita, and patients have minimal outof-pocket expense for either preventative or ongoing care. There is one general hospital and one district hospital on the islands; specialists visit on a rotating basis, and in some serious cases, patients are air-lifted to New Zealand for treatment. SEE ALSO: Healthcare, Asia and Oceania; Hygiene. BIBLIOGRAPHY. C. Everett Koop, et al., eds., Critical Is-
sues in Global Health (Jossey-Bass, 2002); Emerging Issues of Health and Mortality in the Asian and Pacific Region (United Nations Publications, 2005); World Health Organization, The World Health Report 2006: Working Together for Health (World Health Organization, 2006). Heather K. Michon Independent Scholar
Tourette Syndrome Tourette syndrome is a complex debilitating neurological disorder that arises during childhood or adolescence mostly affecting people under the age of 21. The syndrome, first described by Georges Gilles de la
1672 Tourette Syndrome Tourette in 1885, is estimated to affect approximately 1 to 2 percent of the population. The disorder affects males more than females with an approximate ratio of five to one. This chronic idiopathic syndrome is characterized by repeated involuntary movements of the body and face known as tics. Tics are believed to result from dysfunction in the cortical and subcortical regions, the thalamus, frontal cortex, and basal ganglia. Tics are relatively common, affecting 12 to 24 percent of school-age children. Tics are defined as either simple or complex. The former presents with shoulder shrugging, frequent eye blinking, tongue clicking, and sniffing. Complex tics present with frequent jumping, vocal outbursts such as inappropriate swearing, and echolalia (repetition of phrase or sound just heard). As the disease progresses, symptoms of coprolalia also arise, where the patient presents with unprovoked obscene outbursts. Patients may present with various other disorders, for example, psychological disorders such as obsessive-compulsive disorder and attention deficit hyperactivity disorder. Patients may also present with symptoms of anxiety, depression, learning disability, and sleep disturbance. Although the disease has no known etiology, it is suggested that the condition may be inherited. There is a prominent familial occurrence of Tourette syndrome. About 10 percent of patients have a family history of the same condition. In some cases, tics may not be inherited; these cases are identified as “sporadic” Tourette syndrome. Pathophysiology of the disease may involve structural and functional disturbances of the basal ganglia. Reduced caudate nucleus volumes may be a good candidate marker for abnormality in the basal ganglia in persons with the syndrome. Pathophysiology may also include a dysfunction in the processing of dopamine, a neurotransmitter in the brain. It is suggested that the spectrum of behavior can be explained on the basis of a gene causing an imbalance of the mesencephalic-mesolimbic dopamine pathways, resulting in disinhibition of the limbic system. Involvement of dopaminergic systems in the basal ganglia have been suspected to be of etiological importance because of the efficacy of dopamine D2 receptor antagonists in ameliorating some symptoms and the exacerbation of symptoms by dopamimetic agents.
Smaller lenticular nucleus volumes may be an additional marker for the presence of comorbid obsessive-compulsive disorder and for the persistence of tic symptoms into adulthood. The syndrome may also be caused by frameshift mutations in the SLITRK1 (SLIT and NTRK-like family, member 1) gene on chromosome 13. Genetic factors are also implicated in twin studies, which show that the ratio of concordance in monozygotic versus dizygotic twin pairs is approximately five to one. There are no specific medical or screening tests that can be used in diagnosing this disease. Diagnosis includes presence of multiple vocal tics many times a day with an onset before 18 years of age. Tourette syndrome cannot be treated; however, there are treatments available for alleviating symptoms. Various types of therapy have been employed including psychotherapy and cognitive behavioral therapy. The support of family and friends has also been known to help many patients. The only consistent useful medication is the dopamine D2 receptor antagonists, haloperidol (antipsychotic drug), but its use is associated with side effects in approximately 50 percent of the patients treated. Other proven treatments for tics include clonidine and noradrenalin reuptake inhibitors. Relaxation techniques such as yoga have also been suggested as a method for alleviating symptoms. Many people with tics lead a fairly normal life; however, even mild tics can be distressing. The most common disability is social in nature, for example, prejudice. Tics also interrupt the individual’s behavior and thought. Self-injurious behavior is not uncommon caused by inadvertent injuries such as an impulsive behavior to do something dangerous. Although the symptoms may be lifelong and chronic for some, the condition is not associated with an increased rate of morbidity or mortality, and thus patients are able to live a normal life. SEE ALSO: Attention Deficit Disorder with Hyperactivity. BIBLIOGRAPHY. J. T. Walkup, J. W. Mink, and P. J. Hollenback, Tourette Syndrome (Lippincott Williams & Wilkins, 2006).
Farhana Akter King’s College London
Toxicology Toxicology is both the scientific study and direct application of principles regarding xenobiotics (foreign chemicals). Earth is a chemical environment exposing humans to various harmful substances through ingestion, inhalation, and contact. Toxins are naturally occurring substances, whereas toxicants are human-produced substances. Both have the potential to cause death or disease. Chemicals may be classified according to target organ (central nervous system, liver, etc), use (solvent, herbicide, etc.), source (animal, metal, etc), or effects (cancer, birth defects, etc). Chemicals might be classified by their physical state (gas, particulate, etc), their chemical makeup, labeling requirements, potential for poisoning, or the biochemistry within life-forms. In addition to defining and identifying possible poisons or the exposure point of drugs, pesticides, chemical weapons, synthetic fibers, and industrial chemicals, toxicologists study toxic effects at the cellular, biochemical, and molecular levels and determine the probability of the toxic effect as well as safe versus toxic levels in animals, plants, and the environment. Exposure to Harmful Substances The potential for toxicity and adverse effects from chemicals introduced into a human or living organism depends on the route and site of exposure, the duration and frequency of exposure, and other chemical interactions (intentional or unintentional) introduced by other chemicals or the breakdown of the chemical into metabolites. Considerations of exposure include: • Route and Site—chemicals enter the body by ingestion, inhalation, and direct contact. Direct injection into the bloodstream causes the highest and most immediate toxic effect. Localized or systemic effects depend on the chemical and biochemical transformation to more toxic products or reaching target organs. • Duration and Frequency—the chemical stays in a poisonous state or is transformed to a toxin within a living system. Acute exposure is a single occurrence, exposure, or multiple exposures within 24 to 48 hours often occur within a work setting. Chronic exposures occur over a longer period of time and are often environmental. De-
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layed toxicity might not be noticed at the time of exposure and the effects occur in the future. • Chemical interactions—a single chemical may not cause a toxic reaction, but when combined with other chemicals, it produces toxicity. When two or more chemicals combine, the additive effect means individual toxicities create a sum of all effects and the synergistic effect means the chemicals create a greater effect than either one individually or added together. Antagonistic effects or chemical inactivation are the basis for antidotes. The antagonist effect means one chemical is used to counterbalance another by interfering with the other’s chemical action. A functional antagonist effect means one chemical produces opposite effects on the same physiologic function. A chemical antagonist inactivates the first chemical through biotransformation distribution and excretion to alter the concentration or duration of time in the system. Three potential paths of toxicity post exposure to a chemical, include causing immediate damage at the site of exposure, cellular dysfunction and injury once the chemical interacts with target the response or exceeding the system’s ability to fight off or repair damage caused by the chemical. Areas of Specialty Within the science of toxicology are many distinct specialties and disciplines that utilize detection, identification, scientific inquiry, assessment, and
Toxicologists determine acceptable exposure levels and therapeutic application of potentially poisonous substances.
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measurement of the presence and adverse effects of xenobiotics or foreign substances on living organisms—humans, animals, plants, and the environment. Toxicologists determine acceptable exposure levels and therapeutic application of potentially poisonous substances and study the effects of pollution and contamination of air, water, and soil. Analytical toxicology detects, identifies, and measures chemicals through testing for safety, clinical manifestations of deleterious effects from chemicals, and a chemical’s toxicity to fish, birds, plants, and the effect on an ecosystem. From the social standpoint, the work of analytical toxicologists is used to test for alcohol and drugs to determine driving under influence and to analyze urine samples for drugs and their metabolites for legal liability issues. Mechanistic toxicology involves chemical action within living organisms from exposure to a foreign substance through biotransformation, elimination, and the effects and health outcomes. Observation in laboratory animals can be extrapolated to human potential toxicity. The difference between efficacy and the point where toxicity and adverse reaction occurs is evaluated to determine relative safety of a chemical. Clinical toxicology applies analytical and mechanistic principles to determine cause of disease in living subjects with focus on emergency, palliative care, and treatment of poisoned patients. Within this biomedical arena is a subspecialty of pharmaceutical development and testing to determine safe and therapeutic levels of medication. Forensic toxicology uses analytical and standard toxicology principles to determine cause of death or the harmful effects of exposure to hazardous substances. Tests run from sample tissues check for a standard array of possible toxins to determine cause of death or possible poison as cause of disease. Environmental toxicology focuses on xenobiotic effect on the environment and ecosystems from impact from chemical pollution and the disposal of chemical and hazardous waste. Regulatory toxicology as a science uses data collected from other fields of toxicology and outside sources to determine policy on approval or restriction of chemicals, pharmaceuticals, pesticides, and the cleanup of contaminated sites. They are responsible for determining appropriate action to protect the public from hazardous substances and to inform the public of health threats.
Poison Control Programs and Dissemination of Information In the United States, Poison Control Centers respond to questions regarding poisons 24 hours a day, provide information in the event of accidental poisoning, and refer persons for emergency care or proper medical treatment as needed. The National Toxicology Program was established in 1978 and is under the auspices of the Department of Health and Human Services. The impetus for the creation of the program was the belief that many human diseases were caused by direct or indirect chemical exposure. Made up of the National Institute for Environmental Health of the National Institutes of Health, the National Institute for Occupational Safety and Health of the Centers for Disease Control and Prevention, and the National Center for Toxicological Research of the Food and Drug Administration, the program coordinates federal toxicology programs and provide information to the public, regulatory agencies, and the scientific and medical communities. The Agency for Toxic Substances and Disease Registry serves as an information resource and participates in policy development relating to toxic substances in the environment. The International Programme of Chemical Safety of the World Health Organization, publishes Toxicology and Poisoning information, including basic analytical techniques to identify the most common poisoning substances. As a global issue, developing countries need improved access to toxicology education, poison control centers equipped to provide information and care with respect to regional variations in types of poisoning. SEE ALSO: Agency for Toxic Substances and Disease Reg-
istry (ATSDR); Asbestos/Asbestosis; Drug Industry; Environmental Protection Agency (EPA); Environmental Toxicology; Pesticides; Pharmacology; Poisoning. BIBLIOGRAPHY. Agency for Toxic Substance and Disease
Registry Division of Toxicology, www.atsdr.cdc.gov; “Analytical Toxicology,” www.who.int/ipcs (cited May 2007); “History of the NTP,” www.ntp-server.niehs.nih.gov (cited May 2007); M. Gulumian, et al., “Africa’s Present and Future Needs in Toxicology Education: Southern African Perspective,” www.toxnet.nlh.nih.org (cited May 2007); Curtis D. Klaassen, ed., Casarett & Doull’s Toxicology: The Basic Science of Poisons, 5th ed. (McGraw-Hill, 1996); Gabriel L.
Trans Fat
Plas, “Introduction to Toxicology: Occupational and Environmental,” Basic and Clinical Pharmacology (Appleton & Lange, 1998). Lyn Michaud Independent Scholar
Trachoma Trachoma is a bacterial infection that is the leading cause of preventable blindness in the world today. An estimated 8 million people suffer from visual impairment or blindness today, and another 84 million may be infected. Without massive investment in treatment programs, trachoma could blind up to 10 percent of the world’s population in the coming decades. Trachoma is caused by the bacterium Chlamydia trachomatis. It is easily transmitted by human-to-human contact or by a type of fly that feed on the eye discharge of those already infected, which then carries it on to others. Infection usually starts during childhood, but blindness does not come until adulthood. Over the years, repeated periods of inflammation cause scar tissue to form on the inside of the eyelid. Eventually, the eyelashes turn inward—an exquisitely painful phase of the disease known as trichiasis. The sharp eyelashes scratch the cornea, causing severe visual impairment and blindness. The disease was once prevalent throughout the world, but due to improvements in sanitation and standard of living, it has virtually disappeared from Europe and the United States. Today, it exists in Africa, Asia, Latin America, and parts of Australasia. It is endemic in at least 55 countries. Infections tend to come in clusters, striking whole families or communities at the same time. Because blindness strikes in the prime of life, it is estimated that the disease costs US $29 billion in lost productivity each year. Women are three times more likely to contract trachoma than men, making it difficult for them to function in tribal societies, where a woman’s worth can often be based on her ability to cook, to maintain a fire, or collect water from distant wells. Many are abandoned by their husbands, putting a burden on children or other family members to care for them.
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The World Health Organization has developed a treatment protocol known as SAFE, an acronym drawn from four different community-based approaches to combating the disease: (1) surgery for trichiasis; (2) antibiotics for chlamydia trachomatis infections; (3) facial cleanliness; and (4) environmental improvement. Treatment is inexpensive, with surgery for trichiasis costing around $15 per person and antibiotics for early-stage infections around $10 per person. Implementation of SAFE is part of an initiative launched in 1997 called the Global Elimination of Blinding Trachoma by the Year 2020 (GET2020). It has shown tremendous progress in preventing the spread of the disease in pilot programs in Morocco and other countries. SEE ALSO: Eye Care; Eye Diseases (General); Ophthalmol-
ogist; Ophthalmology; Optometrist.
BIBLIOGRAPHY. Julia R. Barrett, “Dilemma for trachoma
treatment?” Environmental Health Perspectives (v.115/1, 2007); Chandler R Dawson, Guide To Trachoma Control In Programmes For The Prevention Of Blindness (WHO Publications Centre USA, 1981); A.W. Solomon, Trachoma Control: A Guide for Programme Managers (World Health Organization, 2006). Heather K. Michon Independent Scholar
Trans Fat Trans fats are a type of unsaturated fat that can be produced commercially by the process of hydrogenation of plant oils and animal fats. Trans fats are also produced naturally in meat and dairy products, but most trans fatty acids in the typical American diet come from hydrogenated foods. A hydrogenation reaction occurs when oxygen or other elements are withdrawn from, or hydrogen is added to, a molecule. The ultimate result is the addition of hydrogen and, therefore, conversion of a polyunsaturated fat (the fats present in vegetables that lower your cholesterol) to a saturated fat. Vegetable oils are hydrogenated in order to make them capable of deep frying foods such as french fries and onion rings.
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Transient Ischemic Attack
Trans fats are typically in processed foods such as margarines, baked goods, cookies, chips, salad dressings, fried foods, as well as cereals. Although they were developed with the intent of replacing the known blood vessel-blocking saturated fats (animal fats found in butter, creams, and meats), it is now known that the trans fats are likely even more damaging to the blood vessels than saturated fats because they live longer in the body. Scientists continue to debate the extent to which trans fats contribute to the amount of bad cholesterol (low-density lipoprotein [LDL]) in the bloodstream. The bad cholesterol can build up on the walls of blood vessels and cause blockage. The blockage could lead to vessel ischemia (decreased oxygen supply) or even infarction (death) of the tissue to which the blood vessel supplies. In 2006, the Food and Drug Administration (FDA) voted to incorporate the reporting of trans fats on nutrition labels present on the packaging of marketed food products. Consumers are now able to make more informed food choices based on the known content of saturated, trans, monounsaturated, and polyunsaturated fats. Trans fats are not an essential (meaning that they must be obtained from a source outside of the body) component of the diet. SEE ALSO: Diet; Dieting; Disease Prevention; Food and
Drug Administration (FDA); Heart Attack (General); Heart Diseases—Prevention; Lean Body Mass; Nutrition; Obesity; Unsaturated Fat. BIBLIOGRAPHY. Denise Mann, “Trans Fats: The Science
and the Risks,” www.webmd.com (cited January 2007); Medicine Net, “Medterms,” www.medicinenet.com (cited January 2007). Lisa Aenlle, M.P.H. Michigan State University
Transient Ischemic Attack Transient ischemic attacks (TIAs) are “mini-strokes” in which stroke symptoms such as weakness, numbness, blindness, or confusion occur for a limited amount of time and then resolve. These incidents are significant because they may herald an impend-
ing stroke. Although there is no treatment for a TIA, there is benefit to a medical workup looking for modifiable risk factors for stroke, such as high blood pressure and smoking, which can be treated and reduce the risk of future stroke. TIAs are incidents where a blood vessel supplying the brain is temporarily occluded, leading to dysfunction of the brain cells which are deprived of the blood’s oxygen. These cells are damaged, leading to symptoms, but can recover and lead to resolution of the symptoms. This most often occurs when a clot or other occlusion occurs inside one of the blood vessels. Several medical conditions can cause these clots; for instance, certain heart problems (such as atrial fibrillation, heart valve problems, or even heart attacks) may cause tiny blood clots to be made in the heart and travel to the brain, or cholesterol deposits in blood vessels within the brain may occlude the vessel. Diseases in which the blood is more prone to clot, such as certain cancers or hereditary blood clotting disorders, may also cause TIAs. TIAs can lead to symptoms such as weakness, numbness or tingling, blindness, confusion, or dizziness. The symptoms are usually on only one side of the body. These symptoms may last only seconds or hours, but all TIA symptoms will resolve soon after they begin. To be considered a TIA, the symptoms must resolve within 24 hours of onset; if they persist and become permanent, a stroke has occurred. People who are experiencing stroke or TIA symptoms should go to the emergency room, and will likely be treated as stroke patients if their symptoms are still present, because there is no way to determine whether the symptoms will go away on their own. They receive the same testing as stroke patients, which includes a computed tomography (CT) scan of the brain. Because TIAs always resolve on their own, no treatment is needed. However, it is important that people who experience a TIA see a doctor and receive testing which may give clues as to why the TIA occurred, because there is a strong chance that a stroke will occur in the future. This testing may include studies of the heart, blood clotting, blood vessels, and brain. Education on ways to prevent strokes is also important, and includes smoking cessation and control of blood pressure, high cholesterol, and diabetes. Some patients may be put on aspirin to reduce the chance of having a stroke. People who have experienced a TIA should
Travel Medicine
not be reassured that the symptoms have resolved, because this “mini-stroke” may be a sign that a larger, permanent stroke is about to take place. SEE ALSO: Geriatrics; Stroke. BIBLIOGRAPHY. Christopher Goetz and Eric Pappert,
Textbook of Clinical Neurology, 2nd ed. (Saunders, 1999); Lee Goldman and Dennis Ausiello, Cecil Textbook of Medicine, 22nd ed. (Saunders, 2003). Cara Sedney West Virginia University
Travel Medicine Travel medicine, aimed at the prevention and treatment of medical complications in travelers and other geographically displaced individuals, embraces specialized areas of tropical medicine, occupation medicine, pharmacology, epidemiology, public health, preventive medicine, and infectious diseases. The primary goal of travel medicine is to keep travelers alive and healthy. This principle applies to tourist travel, students living abroad, corporate travelers, refugees and asylum seekers, and immigrants. The likelihood of a medical illness developing relates to the person’s specific travel destination, duration of travel, level of accommodation, underlying medical condition, immunization history, adherence to indicated chemoprophylactic regimens, and especially his or her history of exposure to potential infectious agents during travel. Eliciting a detailed history of the specific locales visited, the timing of travel relative to the onset of symptoms, and specific risk behavior is essential in determining potential exposure to infectious pathogens and likely incubation period. Particular groups of travelers are considered at higher risk of develop illness after returning to their place of residence. Adventure travelers and those persons visiting friends and relatives overseas are at greater risk for becoming ill, in part because of increased exposure to pathogens. Those visiting friends and relatives are also less likely to seek pretravel advice and to take antimalarial prophylaxis or pretravel vaccinations.
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However, this discipline also deals with the posttravel care of patient who becomes ill during, immediately after, or defined periods after their return. Advising international travelers on vaccine-preventable diseases and malaria prevention strategies are the major services provided by travel medicine practitioners. Many illnesses secondary to a particular exposure during travel may manifest clinically after travelers have returned to their sites of residence. Some of these diseases may manifest immediately after returning, while others may become evident weeks, months, or even years later. This last fact constitutes the rational basis to routinely assess a travel history through the standard medical history taken for every patient. Some of the illnesses that occur in returned travelers may have started to manifest or to be associated with prodromic symptoms during the travel period. In other cases, travelers may be harboring an infectious pathogen in its incubation phase that subsequently becomes clinically present in the immediate posttravel period. Patients going abroad for periods of months to years, presenting for a pretravel medical consultation confront the healthcare worker with a daunting number of complex medical issues. Specialized travel medicine clinics have significantly grown up in the last decade and there is an International Society of Travel Medicine (http://www. istm.org). It is considered relevant that every midsize and large city should count as part of its healthcare services a specialized travel clinic. This is particularly relevant with the significant increase in global travel and the recognition of the specialty of travel medicine have resulted in a growing body of knowledge in the field, and an accompanying increase in research and evidence-based guidelines. Travel medicine has come a long way since it began more than 20 years ago. Currently, with the advances in electronic communications and efficient international travel, the demand for up-to-date information on international health situation is more urgent than before. Disease outbreaks or epidemics can be updated and be available immediately across to the whole world in a matter of hours via the internet. Advances in vaccine development and the work of international agencies such as the World Health Organization (http://www.who.int/) and the Centers for Disease Control and Prevention (http://www.cdc.gov/) have helped further the strategies and the knowledge we
1678 Traveler’s Health have in travel health risks. For travelers, this means that they should no longer be traveling to a destination without knowing the health hazards and without taking the appropriate prophylaxis and precautions. In this way, travel medicine has become an important discipline given the current globalization. International movement of individuals, populations, and products is one of the major factors associated with the emergence and reemergence of infectious diseases as the pace of global travel and commerce rapidly increases. Travel can be associated with disease emergence because (1) the disease arises in an area of heavy tourism, (2) tourists may be at heightened risk because of their activities, or (3) because they can act as vectors to transport the agent to new areas. Examples of recently recognized diseases with relationship to travel include severe acute respiratory syndrome (SARS), avian influenza, HIV, Legionnaire’s disease, cyclosporiasis, Vibrio cholerae O139 Bengal, hantavirus, and variant Creutzfeldt-Jacob disease. Reemerging diseases include dengue fever, malaria, cholera, schistosomiasis, leptospirosis, and viral hemorrhagic fevers. In addition, tuberculosis, drug-resistant shigellosis, and cholera have been major concerns in refugee and migrant populations. Because of the unique role of travel in emerging infections, efforts are under way to address this factor by agencies such as the Centers for Disease Control and Prevention, the World Health Organization, the International Society of Travel Medicine, and the travel industry. SEE ALSO: Epidemiology; Mosquito Bites; Parasitic Dis-
eases.
BIBLIOGRAPHY. David O. Freedman, et al, “Spectrum
of Disease and Relation to Place of Exposure among Ill Returned Travelers,” New England Journal of Medicine (v.354/2, January 2006); M.S. Lam and S.Y. Wong, “Travel Medicine: A Perspective on the Emerging Problem of Travel-Related Infections,” Annals of the Academy of Medicine, Singapore (v.26/5, 1997); P.A. Leggat, “Risk Assessment in Travel Medicine,” Travel Medicine and Infectious Disease (v.473–4, 2006); S.M. Ostroff and P. Kozarsky, “Emerging Infectious Diseases and Travel Medicine,” Infectious Disease Clinics of North America (v.12/1, 1998); A.J. Rodriguez-Morales, et al., “Impact of Imported Malaria on the Burden of Disease in Northeastern Venezuela,” Journal of Travel Medicine (v.13/1, 2006); M. Rossi and H. Furrer,
“Travel Medicine for HIV-Infected Patients,” Therapeutische Umschau (v.58/6, 2002); Edward T. Ryan, et al., “Illness after International Travel,” New England Journal of Medicine (v.347/7, 2002); S. Venkatesh and Z. A. Memish “SARS: The New Challenge to International Health and Travel Medicine,” Eastern Mediterranean Health Journal (v.10/4–5, 2004). Alfonso J. Rodriguez-Morales, M.D., M.Sc. Universidad de Los Andes Carlos Franco-Paredes, M.D., M.P.H. Emory University
Traveler’s Health Over the past two decades, economic and cultural globalization and the increasing affordability of air travel have led to an exponential rise in international travel. Businesspeople, backpackers, students, and families have all participated in this phenomenon. While much of this travel has occurred between highly industrialized countries, this era has also seen a significant rise in travel to less developed countries, exposing travelers to a variety of health risks to which they are usually unaccustomed. Preparing these travelers prior to departure and treating their ailments upon their return has generally been the responsibility of general medical practitioners. In recent years, however, a new interdisciplinary specialty known as travel medicine has begun to emerge to provide specialized knowledge and experience. Ensuring the health and safety of travelers is a three-part process: prevention, safe practices, and treatment. Preventative measures include region-specific vaccination and malaria prophylaxis. Safe practices refer principally to food and water safety. When these preventative measures fail, travelers should be prepared to treat common ailments and seek local medical expertise. Preparation for Travel Before traveling to any destination, it is important to research the need for any vaccines or prophylaxis against illnesses endemic to that area. Resources include the Centers for Disease Control and Prevention (CDC) and the World Health Organization (WHO).
Traveler’s Health
Researching the availability of potable water is also important, as water purification tablets are an easy and affordable option to prevent water-borne illnesses. Given the prevalence of certain maladies in different regions of the world, it comes as no surprise that vaccination is often required to obtain a visa. Visitors should access country-specific vaccination requirements via the CDC’s or WHO’s Web sites. Travelers should always check with their hotels, hostels, or contacts at their destinations regarding the availability of primary care as well as emergency medical services. These resources are often at the beginning of a guidebook or on the WHO’s Web site. When preparing to travel to a destination where resources are known to be scarce, it is not unreasonable to prepare a basic traveler’s first aid kit, which should include the following: • Adhesive bandages • Antibiotic ointment • Lip balm • Sunscreen • Gauze • Disposable latex gloves • ACE wrap bandage • Diphenhydramine
• • • •
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Moist towelettes Ibuprofen/acetaminophen Aspirin Thermometer
Malaria Malaria is caused by several parasites in the Plasmodium genus, most commonly P. falciparum, causing 80 percent of infections and 90 percent of the deaths attributed to malaria. The parasite is transmitted by the saliva of the Anopheles mosquito and undergoes a complex life cycle in the blood of humans, ultimately resulting in a constellation of signs and symptoms that are cumulatively called malaria. Symptoms include fevers, joint pains, nausea, and a low blood count caused by destruction of red blood cells. Prevention of malaria centers on avoiding contact with mosquitoes in endemic areas via use of DEET-containing sprays and mosquito nets at night. Medical options classically include chloroquine, but given the evolution of chloroquine-resistant organisms, mefloquine is often recommended as an alternative. For travelers who are intolerant to their numerous side effects, doxycycline is another option. Other formulations exist and should be discussed with the prescribing physician.
Conditions such as HIV, malaria, tuberculosis, and water-borne illnesses do not recognize national boundaries and will not be left behind at customs, and travelers should approach their health by focusing on prevention.
1680 Traveler’s Health Safe Food and Water Following safe food and water practices while traveling in developing countries takes discipline and vigilance, and adherence to all of the following guidelines is often impossible. Careful dietary control can, nevertheless, prevent or at least reduce the severity of the gastrointestinal infections that plague travelers. Freshly cooked food is the best option for travelers. Salads and raw vegetables and fruits (unless peeled) should not be eaten, as they are often rinsed in untreated water. Raw or undercooked meat and seafood should be avoided at all times, as should cooked foods that have been allowed to cool to room temperature. Water may be more difficult to control, and travelers often drink only bottled water from trusted regional or international manufacturers. Boiling water (longer than one minute of vigorous boiling) is a safe alternative to bottled water. Commercially available chemical treatment options, usually involving iodine or chlorine, are lessthan-ideal alternatives and often leave a residual chemical taste to the water. Filtration devices are the least effective means of water purification, though depending on the specific device may provide a certain level of protection. Travelers should take care to avoid ice in restaurants, as they have no way of knowing the safety of the water source. Unfortunately, strict adherence to all of these guidelines does not ensure complete protection against gastrointestinal infections, that is, diarrhea.
per day, though their effectiveness in treating the diarrhea itself is unclear. In cases where the diarrhea is bloody or streaked with mucus, or when the traveler also has a fever, antibiotics may be necessary and the traveler should consult a physician. When travelers are unable to stay well hydrated due to nausea and vomiting, they may need hospitalization for intravenous fluids.
Diarrhea Over 1 billion people suffer from an episode of diarrhea every year, caused by viruses, bacteria, and parasites acquired via poor hygiene and insufficient food and water safety measures. Defined broadly as an increase in the number stools or a loosening of their consistency, diarrhea is the most common medical complaint of travelers. Treatment of diarrhea is generally aimed at maintaining hydration and nutrition while the disease itself runs its course. Travelers should eat foods such as bananas and rice. They should drink plenty of water and consider mixing in oral rehydration salts, which are available in sachets in pharmacies around the world. Antidiarrhea agents such as bismuth salts (Pepto Bismol®) and loperamide (Immodium®) are often used by travelers to decrease the number of bathroom visits
Conclusion As borders continue to fall and travel becomes accessible to more citizens of the world, the health of travelers continues to become an increasingly important issue in 21st century medicine. Conditions such as HIV, malaria, tuberculosis, and water-borne illnesses do not recognize national boundaries and will not be left behind at customs. Travelers should approach their health by focusing on prevention. For that reason, it is essential for travelers to familiarize themselves with local cuisine, to receive the necessary vaccinations, and to understand the health risks of traveling to specific areas of the world. Sometimes health risks or emergency situations are unavoidable, which is why traveler’s insurance may be of use (with or without coverage of medical evacuation). Ultimately, this era of global travel will allow citizens of different nations
HIV Prior to departure, any traveler should be aware of the health and political situation of their destination. In countries with a high prevalence of HIV infection, for example, South Africa, India, Russia, and China, additional precautions may need to be taken. Travelers to any country, whether it is an industrialized or developing nation, should avoid sexual contact with commercial sex workers. If a traveler requires a blood transfusion for any reason, they should insist that each unit of blood product is screened for HIV and other blood-borne pathogens. When visiting dental or medical clinics, they should also ensure that all instruments are properly sterilized and stored when not in use. This may also be an issue for travelers visiting tattoo or body piercing parlors. Travelers with chronic medical conditions should travel with an adequate supply of whatever common medical instruments they may require. Diabetics, for example, should travel with their own supply of disposable syringes rather than relying on local availability.
Tremor
to experience and share cultural differences and commonalities—for that reason, both patients and physicians should be aware of the regional health risks of traveling and prepare accordingly. SEE ALSO: Adult Immunization; Centers for Disease Con-
trol and Prevention (CDC); Diarrhea; Drinking Water; Giardia Infections; HIV; Malaria; Travel Medicine.
BIBLIOGRAPHY. Centers for Disease Control and Preven-
tion, www.cdc.gov/travel; Harrison’s Textbook of Medicine, 14th ed. (McGraw-Hill, 1998); Bret A. Nicks, “Wilderness and Travel Medicine,” www.emedicine.com/emerg/ topic838.htm (cited July 14, 2005); Nicholas J. White and Joel Bremen, “Malaria and Other Diseases Caused by Red Blood Cell Parasites,” Harrison’s Textbook of Medicine, 14th ed. (McGraw-Hill, 1998). Amit Chandra, M.D., M.Sc. New York Hospital Queens Matthew Dacso, M.D., M.Sc. Brown University
Tremor Tremor is an uncontrolled movement of part of the body, which often occurs in a regular or rhythmic pattern. Tremor is generally caused by some malfunction of the brain or nervous system which leads to the transmission of the signal to the part of the body, often the face or hands, to move in a way that does not provide any benefit to the body. Some forms of tremor are caused by genetic disorders, while others are symptoms of diseases of various kinds. One of the more common types of tremor is the inherited condition known as essential tremor. This can strike at any age and is not often serious unless the patient is pursuing some occupation or craft that demands total control of the hands or other affected body part. The tremor has often been countered historically through alcohol use, which is effective but may lead to other problems. Beta-blocker drugs have become popular as more long-term and sustainable options. Essential tremor can also affect the voice and the legs and may be intensified during periods of emotional or physical stress. This can become severe
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and lead to considerable levels of stress for those experiencing the condition and those close to them. A well-known cause of tremor is Parkinson’s disease, which leads to involuntary movements in many parts of the body and is associated with difficulties in moving and in performing numerous daily tasks. The cause of this disease is not fully established and cannot be prevented from running its course, although modern drugs have proved reasonably effective in prolonging life and maintaining quality of life. An area of research investigating the ability of cannabinoids to reduce or eliminate tremor has proved controversial. The substances investigated are present in the drug cannabis, which is illegal in most countries and which is considered by many to be a “gateway” drug leading to experimentation with more destructive substances. The research is also controversial because of the limited amount of substantiation for claims of the use of the substance and the very high subjective regard that some people have of it. There are, in addition, many other possible causes of tremor. These include neurodegenerative diseases which attack the brain, liver failure, multiple sclerosis, brain injury or stroke, and the effect (or withdrawal from) of alcohol, caffeine, or other substances which have a drug-like effect on the body. These latter causes are likely to have a temporary effect on the body and the former a more permanent one. The various factors may also act in combination and, in the case of drugs, the cause of the tremor may also be the means of remedying it, albeit only for a limited period of time. Repeated trauma such as being struck on the head can also lead to tremor in all parts of the body on an unpredictable basis. Boxers and others suffering these kinds of blows on a regular basis are particularly vulnerable. A brain disorder such as cerebral palsy can lead to extensive involuntary movement or spasticity. These forms of movement may be so extreme as to prevent the patient being able to complete regular daily activities and may themselves lead to additional, physical stress-related symptoms. However, there is no automatic link between conditions such as this and mental retardation and, with palliative treatments such as muscle relaxant drugs, adult sufferers can enjoy good quality of life and productive careers. In general, there are no cures for most forms of tremor. Many forms can be treated with various
1682 Trinidad and Tobago approaches toward relaxation which will reduce the severity of the tremor. SEE ALSO: Geriatrics; Parkinson’s Disease. BIBLIOGRAPHY. David Baker, et al., “Cannabinoids Con-
trol Spasticity and Tremor in a Multiple Sclerosis Model,” Nature (v.404, 2000); Mark Plumb and Peter Bain, Essential Tremor: The Facts (Oxford University Press, 2006). John Walsh Shinawatra University
Trinidad and Tobago Trinidad and Tobago are located in the Caribbean Ocean, just off the coast of Venezuela. The entire state is comprised of 23 islands; Trinidad, the largest, is 4,828 square kilometers, while Tobago, the second largest is just 300 square kilometers. Like many countries in the Caribbean, it is a multiethnic, multicultural society comprised of the descendents of groups brought there over the centuries. The combined population of the islands is 1,065,000. The birth rate is 12.9 per 1,000, the death rate is 10.57 per 1,000, and the migration rate is minus 11.07 migrants per 1,000, leading to a population decline of minus 0.87 percent annually—the lowest population growth of any country in the world. Economics seem to be the driving force behind the falling population. Trinidad and Tobago are liberal democracies, highly industrialized societies with strong exports in agricultural goods, petroleum, and petrochemicals; there is strong foreign investment and a growing tourist sector. Still, the per capita income for Trinidadians and Tobagonians is $8,580 a year, and 22 percent of the population live under the poverty level—4 percent on less than $1 a day. Unemployment stands at 8 percent. Key health demographics are solid. Life expectancy at birth is 65.71 years for males and 67.86 years for females. Infant mortality is 25 deaths per 1,000 live births; another 20 per 1,000 die between the ages of 1 and 5. Maternal mortality is 160 per 100,000 live births. Ninety-two percent of women receive prenatal care and 96 percent give birth with the help of a trained attendant.
Major infectious diseases are under control. Ninety-five percent of all children receive immunizations for polio, hepatitis B, diphtheria, pertussis, tetanus, and other risks. Ninety-one percent of the population have access to safe drinking water and 100 percent use sanitary facilities. The country was declared malaria-free in 1965. Leptospirosis rates have been dropping for years. Meningococcal infections are sporadic, as are cases of dengue fever. Food-borne illnesses such as salmonella and shigella increased between 2002 and 2004, as did influenza and hepatitis B. The human immunodeficiency virus (HIV)/AIDS rate stands at 3.2 percent, with about 29,000 islanders living with the virus and an estimated 1,900 deaths from the virus through 2003. Tuberculosis rates have also risen. The Ministry of Health has recently expanded its AIDS education campaign. Deaths related to violent crime have increased in recent years, fueled in part by a growing drug trade and increased gang activity. Deaths due to domestic violence have also risen. Traffic-related fatalities climbed from 5.8 deaths per 1,000 accidents in 1998 to 11.2 deaths per 1,000 accidents in 2003. In 2004, Parliament passed the Occupational Safety and Health Act, creating the framework for worker protection on the job. Among its provisions, it codified the right of employees to refuse work “where safety or health is in danger.” Subsequent amendments will increase the authority of state officials to monitor safety and levy fines and other remedies. The government spends about $120 per capita on healthcare each year. The Ministry of Health runs the state hospital system and the insect-vector control and surveillance programs, and monitors food safety and water quality. There are eight large hospitals and 107 clinics scattered throughout the islands, augmented by a private-care sector. In 1997, the World Health Organization counted 1,004 physicians and 3,653 nurses working within the country. SEE ALSO: Healthcare, South America. BIBLIOGRAPHY. Scott B. MacDonald, Trinidad and Toba-
go: Democracy and Development in the Caribbean (Praeger, 1986); Karl Theodore, Analysis of the Investment Process in the Environment and Health in Trinidad and Tobago (World Health Organization, 1994); Karl Theodore, Poverty
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Reduction Strategies: The Role of Health and Education: A Trinidad and Tobago Perspective (PAHO/WHO, 1995). Heather K. Michon Independent Scholar
Tropical Medicine Tropical medicine is a branch of medicine that, as its name implies, is primarily concerned with health problems occurring in tropical or subtropical regions of the world. The discipline of tropical medicine developed primarily as a response to diseases encountered by European colonists and entrepreneurs during their travels to the tropics and upon their return. Illnesses such as yellow fever, malaria, filariasis, and many others threatened the citizens and the financial interests of the European powers and created a considerable incentive to better understand, prevent, and treat these diseases. Because tropical diseases are often encountered during travel, the subspecialty of travel medicine, including pre-travel, travel, and posttravel clinical medicine, is often subsumed within the specialty of tropical medicine. It was once thought that tropical diseases differed from diseases found in temperate regions due to the climate, flora, and fauna of tropical regions which are more conducive to the spread of certain types of infectious disease. This is only partially true. The warm, moist climates of some tropical areas are home to more diverse and more dense animal and insect populations which may harbor and transmit disease to humans. However, it is now clear that public health interventions such as improved personal hygiene, sanitation, adequate diet, and housing are more important determinants of infectious disease prevalence and transmission than climate. In fact, many “tropical” diseases such as malaria and cholera were once endemic in temperate or cold areas such as the United Kingdom, Canada, and the United States, but were controlled and eliminated early in the 20th century. The reasons that most industrially developed countries are located in temperate areas, while most developing and poor countries are located in tropical or subtropical zones, are very complex and controversial but are closely related to factors that
Warm, moist tropical climates are home to more animal and insect populations, which may transmit disease to humans.
influence the determinants of health. These sociopolitico-economic factors significantly affect public health infrastructure, availability of medical care, and education—the main determinants of diseases which fall into the realm of tropical medicine. As a result, the discipline of tropical medicine relies on methods from public health fields, including epidemiology, biostatistics, health promotion, and disease prevention, to combat these diseases. Infectious diseases such as viruses, bacteria, fungi, and parasites are still the mainstays of tropical medicine. Other areas, such as nutritional diseases and disaster response, are now receiving more attention in tropical medicine curricula as they interact with infectious diseases to cause human suffering, illness, and death. Parasitic diseases, including worms that infect the intestinal system, the skin, and the blood, are most often the exclusive realm of tropical medicine because they are now fairly rare in developed countries but very common in developing countries. Intestinal parasites are most often transmitted when infected persons contaminate food or water with worm eggs by defecating in soil or water. These eggs are then ingested and complete their lifecycle in a new host causing disease or asymptomatic carriage. While some eggs cannot survive in cold environments, a tropical climate is far less important than food hygiene and sanitation in the transmission of intestinal parasites. In
1684 Tuberculosis addition, these diseases can be easily diagnosed and treated if adequate primary care is available. Malaria, a blood parasite now also considered a tropical disease, is transmitted by mosquitoes which were once common in the United States, Canada, and parts of northern Europe. The disease was controlled by eliminating mosquito breeding areas, treating cases of disease, and ensuring adequate housing which excluded mosquitoes from homes at night when they are most active. In many developing countries, inadequate housing and poor education regarding mosquito bite prevention, combined with longer breeding seasons and poor access medical care, lead to millions of death per year from malaria and its complications. Dealing with new and emerging diseases such as severe acute respiratory syndrome (SARS) and pandemic influenza require the participation and skills of tropical medicine specialists who understand the principles of epidemiology and infectious disease transmission in areas of the world where these diseases may originate or amplify. The warming global climate and increasing human settlement have led to the changes in the patterns of diseases such as mosquito-borne malaria and dengue fever which are now found at higher altitudes and in urban areas where they were never found before. Increasing resistance to antibiotics due to their overuse also presents new challenges to tropical medicine specialists. The World Health Organization has identified 10 “tropical” diseases that disproportionately affect poor and marginalized populations. These diseases are African trypanomyasis (African sleeping sickness), dengue fever (break-bone fever), leishmaniasis, malaria, schistosomiasis, tuberculosis, Chagas disease (American trypanomyasis), leprosy (Hansen’s disease), lymphatic filariasis, and onchocerciasis (river blindness). The control of these diseases requires a multidisciplinary approach which addresses the three cardinal aspects of disease—the host, the disease agent, and the environment. As opposed to the traditional focus on treating clinical disease, in combating these diseases the focus must be on preventing disease by reducing the disease vectors, reducing exposure to the disease, and reducing the host susceptibility to disease. The spread of human immunodeficiency virus (HIV) has complicated the prevention and treatment of many tropical diseases which were recently under control, and has taxed health systems to their
breaking point. The emergence of multidrug-resistant (MDR) and extensively drug-resistant (XDR) tuberculosis are also public health concerns related to tropical medicine. The title tropical medicine has remained for historical reasons in most academic departments, although some may refer to it as international medicine or geographic medicine. Specialists from a number of disciplines, including family medicine, infectious diseases, and public health, may pursue further studies to become tropical medicine specialists. These studies most often include a diploma course in tropical medicine offered at several sites worldwide. Those who have completed one of these courses may write an examination offered by the American Society of Tropical Medicine and Hygiene and obtain a Certificate of Knowledge in Clinical Tropical Medicine and Travelers Health. SEE ALSO: Travel Medicine; Traveler’s Health. BIBLIOGRAPHY. Michael Eddleston, et al., Oxford Hand-
book of Tropical Medicine, 2nd ed. (Oxford University Press, 2004); George W. Hunter, et al., eds., Hunter’s Tropical Medicine and Emerging Infectious Diseases, 8th ed. (W.B. Saunders Company, 2000); Elaine C. Jong and William Russell McMullen, The Travel and Tropical Medicine Handbook, 3rd ed. (Saunders, 2002). Barry Pakes, M.D., M.P.H. University of Toronto
Tuberculosis Tuberculosis (TB) is a curable disease that affects the respiratory system. It kills approximately 1.6 million people per year and is returning, partly due to increased travel and migration opportunities, to those Western countries where it had been thought to be eradicated. The main means of spreading the disease is through coughing and sneezing. Tubercles form as lesions which consist of some dead tissue and are ringed by scavenger cells (phagocytes); the lesions form as part of the body’s natural reaction against the presence of infection. Tubercles themselves are too small to see with the naked eye, but they can agglom-
erate to form large tuberculous masses which cause particular damage. The most common form of tuberculosis is pulmonary tuberculosis and children and young people are more vulnerable to this form, although infections can occur at any age. Primary pulmonary infection may pass without major incident but might leave infection in the bloodstream or a tear on the lung. Subsequent increases in infection will occur in general terms over a lengthy period, with the patient suffering from weakening of strength, coughing, and loss of color and vigor. X-ray examination can reveal the presence of damage to the lung and medical advice should be sought if persistent symptoms are observed, particularly if contact with another infected person is possible or suspected. Other areas of concern include tuberculous meningitis and bone and joint tuberculosis, although the pasteurization of milk has been an effective counter to the latter problem. The principal cause of death is the spreading of lesions across the lungs, which leads to a reduction in the ability of the patient to breathe which intensifies and is accompanied by the characteristic coughing up of blood. In 1882, Robert Koch, a German physician, identified the tubercle bacillus as being responsible for the disease. These include several species of mycobacterium, most notable of which is M. tuberculosis, which is responsible for infection of humans. Cows and some domestic animals are also susceptible to the disease. It has been known to be a lethal disease throughout history and has been particularly deadly in urban areas and places where hygiene conditions are poor. Clearly, therefore, the poor have been more vulnerable to the disease than the rich. Affected people suffered from breathing problems and some achieved limited relief by exposure to cool weather in a lofty climate, such as were to be found in mountainous terrain. European sufferers who could afford to do so, therefore, might be sent to Switzerland to seek a cure. American sufferers also were sent to mountainous areas in that country. By 1990, some 3.8 million cases of tuberculosis were reported globally and 49 percent of these were in southeast Asia. The disease was largely active in that region and in sub-Saharan Africa. The number of cases had started to increase because of the spread of human immunodeficiency virus (HIV), the presence of which causes an increase in the like-
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lihood that a person infected with TB will go on to develop a full case of it. A second problem increasing the prevalence of TB is resistance to existing drugs, which has become a serious issue, especially in the United States. Even so, it appears that the total number of incidences of TB cases may have peaked globally, although the shift toward outbreaks in Asia and sub-Saharan Africa continues. Another area of concern is the eastern Mediterranean, where total numbers of new cases continue to rise. In 2005, 7.4 million out of an 8.8 million total of new cases of tuberculosis were found in Asia and sub-Saharan Africa. Of the 1.6 million deaths due to the disease, some 195,000 people were also suffering from HIV. The World Health Organization (WHO) is the leading organization in managing the epidemiology of disease globally and the encouragement of good public health practice around the world. To combat TB, the WHO created the directly observed therapy strategy (DOTS), which has been put into practice in 187 countries as of 2005, which account for approximately 89 percent of the world’s population. DOTS has five main elements: (1) political commitment with increased and sustained financing; (2) case detection through qualityassured bacteriology; (3) standardized treatment, with supervision and patient support; (4) an effective drug supply and management system; and (5) a monitoring and evaluation system, with impact measurement. DOTS has been successfully implemented to some extent and it is to be supplemented and improved by a new Stop TB Strategy, together with a global fund to support operations. This continues to be necessary because of the number of multidrug-resistant tuberculosis sufferers (MDR-TB) and extensively drug-resistant tuberculosis patients (XDR-TB). It is estimated that an additional $1.1 billion in addition to the $2 billion already available in 2007. A substantial portion of this additional funding is required because of the envisaged greater role for advocacy and community organization in the countries most badly affected. This and increased case-finding strategies in countries with poor infrastructure and inadequate technical capacity will be required if one of the key Millennium Development goals is to be achieved. However, better information is required before it can be determined exactly what the status of the goal is. SEE ALSO: Pulmonology; Respiratory Diseases (General).
1686 Tuberous Sclerosis BIBLIOGRAPHY. Matthew Gandy and Alimuddin Zumla,
The Return of the White Plague: Global Poverty and the “New” Tuberculosis (Verso, 2003); M. C. Raviglione, et al., “Global Epidemiology of Tuberculosis: Morbidity and Mortality of a Worldwide Epidemic,” The Journal of the American Medical Association (v.273/3, 1995); World Health Organization, Global Tuberculosis Control—Surveillance, Planning, Financing (World Health Organization, 2007). John Walsh Shinawatra University
Tuberous Sclerosis Tuberous sclerosis, also called tuberous sclerosis complex (TSC), is a disease marked by the formation of widespread benign tumors throughout the body. This disease has a well-established molecular link, which stems from defects or mutations in either of two genes TSC1 and TSC2. Widespread consequences of these mutations lead to a triad of multiple organ system disorders. Eighty percent of patients present with benign tumors in the brain that cause disabling neurological abnormalities including epilepsy, mental retardation, and autism. TSC is also associated with multiple benign tumors of other vital organs, which include the heart, kidneys, skin, lungs, and eyes. Individuals with TSC may experience none or all of the symptoms with varying degrees of severity. The name tuberous sclerosis comes from the characteristic tuber or root-like growths in the brain. TSC affects as many as 25,000 to 40,000 individuals in the United States and about 1 to 2 million individuals worldwide, with an estimated prevalence of one in 5,000 to 10,000 newborns. TSC occurs in all races, ethnic groups, and in both genders. There is no cure for TSC, although treatment is available for a number of the symptoms. TSC is an autosomal-dominant disorder, with full penetrance, which means that the disease is carried by a dominant gene, and if a parent has a mutation in the TSC1 or TSC2 gene, each offspring has a 50 percent chance of developing the disorder. The TSC1 gene, on chromosome 9, and the TSC2 gene, on chromosome 16, produces two proteins, hamartin and tuberin, in a normal individual. These proteins help orchestrate a signaling cascade within
the cell that controls growth and proliferation. Defects or mutations in TSC1 or TSC2 causes disruption of the signaling cascade, causing the affected cell to grow uncontrolled. Scientists are currently studying this signaling cascade and are developing drugs to prevent the growth of established tumors. Rapamycin, also known as sirolimus, has been shown in preliminary clinical studies to induce tumor regression in patients with TSC. The major clinical features of TSC are the cortical tubers and neurologic abnormalities. Cognitive deficits, including learning disabilities, and seizures begin in infants before 2 years of age in over 70 percent of cases. Antiepileptic drugs may be used to control seizures, and medications may be prescribed for behavior problems. Intervention programs including special schooling and occupational therapy may benefit individuals with special needs and developmental issues. Individuals with TSC may gain further information from a TSC clinic that specializes in diagnosis, primary care, and treatment of the disorder. Physicians and patients are referred to the Tuberous Sclerosis Alliance Web site (www.tsalliance.org) to gain any further useful information, which includes current research, therapeutic developments, clinical trials, counseling, and general support, and TSC clinic locations. SEE ALSO: Cancer; Mental Retardation; National Institute
of Neurological Disorders and Stroke (NINDS).
BIBLIOGRAPHY. P. B. Crino, K. L. Nathanson, and E. P.
Henske, “The Tuberous Sclerosis Complex,” New England Journal of Medicine (v.355/13, 2006); National Institute of Neurological Disorders and Stroke (NINDS), “The Tuberous Sclerosis Fact Sheet,” www.ninds.nih. gov/disorders/tuberous_sclerosis/tuberous_sclerosis. htm (cited October 2006). Matthew R. Janes University of California, Irvine
Tumor Registry With cancer being one of the most common causes of death around the world, many cities established tumor registries (often called cancer registries) which
collected, collated, and then studied cancer statistics to show the relative rates of prevalence of people suffering from cancer in a particular place. Although these were often run by individual towns—some very early ones were run by particular large hospitals—it was not long before more and more national cancer registries were established, covering all deaths in a particular country. At its most basic level, the tumor registry collects the details of the number of people in a particular area who died from cancer. This was later expanded to cover information on the sex of the person, age, residence, and a measure of various high-risk factors such as whether the person smoked tobacco or had given up smoking earlier on. It has also been possible to collect information on whether other family members had died from cancer. Some tumor registries used information from death certificates, cemetery records, medical registers, and also hospital records to “backdate” their records and include information on people who have already died. This was particularly useful when tumor registries were being established because it allowed cancer researchers to make some attempt at a comparative survey of who has been suffering from cancer in a particular area and over what time span. Tumor registries now often include the collection of information on cancer in living people, not solely death records, and this has not only massively increased the data collected, but it has also considerably augmented the potential use of these statistics. As a result of the vast amount of data collected by cancer registries all over the world, and for some of them, over a long period, it has been possible for cancer researchers to spot the greater prevalence of particular types of cancers in some parts of the world, and indeed, in some parts of specific countries. This can then be compared to some similar types of cancers in other parts of the world and over different periods. It has helped researchers follow hypotheses to follow causes of cancer, and as a result, it has helped medical professionals work out techniques of diagnosis and improve therapy. Furthermore, tumor registries have also been used to monitor and measure the effects of preventive measures when they were introduced. It has also been possible to show the different levels of cancer which could continue from a comparison of specific
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treatment by different hospitals. It has even managed to work out which physicians have managed to treat more patients successfully. In the United States, the National Program of Cancer Registries brings together the state-based systems and covers 45 states, the District of Columbia, Puerto Rico, the Virgin Islands, and the Republic of Palau— about 96 percent of the U.S. population. In Canada, the Canadian Cancer Registry operates from Ottawa. The other tumor registry dating to before World War II is the Central Cancer Registry in Melbourne, Australia, established by Robert Fowler in 1939. In Central America, many countries have their own tumor registries, the best-known being the Registro Nacional de Tumores (Costa Rica National Tumor Registry) run by the Ministry of Health in San José. In South America, there are a range of tumor registries throughout Argentina and Brazil, with the results only being collected together in recent years; now both countries are covered in their entirety. Other countries that had a number of registries include Ecuador, Peru, and Colombia, the last having the Cali Cancer Registry from as early as 1962. There is a small tumor registry in La Paz, covering Bolivia, and another in neighboring Paraguay, based in Asunción. In Europe, various hospitals in Britain started the practice of collecting tumor statistics, with it gradually being collated by local authorities, and now there are 12 cancer registries in the United Kingdom which together cover the entire nation, the largest being the Thames Cancer Registry which covers London, Surrey, Sussex, and Kent, with data dating back to 1960. In Ireland, it was not until 1975 that the Southern Tumour Registry was established, located in Cork, with its work later subsumed by the Irish National Cancer Registry which was established in November 1991 by the Department of Health. The Danish Cancer Registry was established in May 1942, when Denmark was run by a pro-German government. It maintained itself as a separate identity until 1997 when cancer registration was made a part of the responsibilities of the National Board of Health. The Cancer Registry of Norway was established in 1951, collecting statistics from 1953. The Finnish Cancer Registry was set up in 1952, with registration across the country by the following year. In eastern Europe, the first tumor registry to be established seems to have been the Cancer Registry of
1688 Tumor Registry Slovenia which was founded in the 1940s. The registry in East Germany was set up in 1949. Exactly 10 years later, the Croatia Cancer Registry was formed, working out of the Croatian National Institute of Public Health, with a tumor registry in Serbia not being established until 1975. In Romania, a number of registries were set up throughout the country. The Soviet Union did not establish a complete tumor registry until after the 1950s with the precursor to the Kyrgyzstan Cancer Registry collecting data from 1958. The Belarussian State Cancer Registry was established in 1965. This was the registry used to show that thyroid cancer cases were far more prevalent in Belarus than in either the Ukraine or the Russian Federation following the nuclear disaster at Chernobyl in the Ukraine on April 26, 1985. As elsewhere, a number of north African countries, such as Algeria and Egypt, operate a number of different cancer registries which cover separate parts of the country—the first in Algeria being established as late as 1989. In Libya, its first tumor registry, the Benghazi Cancer Registry, did not start operations until 2003. Throughout sub-Saharan Africa, the work of tumor registries has been difficult because of budgetary problems and wars. The Kampala Cancer Registry was established 1951 in Uganda’s capital, but effectively closed from 1972 until 1987 owing to the political situation. Similarly, the Bulawayo Cancer Registry established in Rhodesia (modern-day Zimbabwe) in 1963, was forced to close in 1978. However, after independence for Zimbabwe, in 1985 the National Cancer Registry was established at Parirenyatwa Hospital, Harare, Zimbabwe’s capital. In larger countries such as South Africa and Nigeria, there are a number of tumor registries covering different cities—the first to be established in Nigeria being that in Ibadan set up by the University College Hospital in 1960. To improve the state of cancer registries in the rest of Africa, a number of foreign researchers have been heavily involved, including Dr. D. M. Parkin who helped with the tumor registry in Butare in southern Rwanda and in many other countries. The Cancer Registry of Mali was set up in January 1986 as a part of the pathology service of the National Institute of Public Health Research (INSRP). A registry in Conakry, the capital of Guinea, has been operating from 1992, and one in Abidjan, the capital of the Côte d’Ivoire, has been collecting data since 1995.
In the Middle East, there are a number of tumor registries in Turkey, but the earliest national tumor registry is the Israel National Cancer Registry, established in the early 1950s. The tumor registry in Iran was established in 1968, in Iraq in 1976, and Jordan in 1996. Yemen still has no tumor registry. India has a large number of cancer registries covering cities and provinces. The Karachi Cancer Registry was the first to be established in Pakistan in the 1960s. China and Japan have many regional tumor registries; in both countries the registries originally covered cities, but now, there are many authorities, which altogether, cover the entire country. South Korea also has a national tumor registry. In southeast Asia, the oldest cancer registry appears to be that in Singapore which started in January 1968 with doctors and other medical professions encouraged to report details on cancer deaths. The National Cancer Registry of Malaysia, supported by the Ministry of Health, collects cancer data for the entire country, whereas Thailand and Indonesia have a range of regional registries. In Vietnam, a tumor registry was set up in Hanoi in 1987, and in Ho Chi Minh City three years later. In Myanmar, the Yangon Cancer Registry operated from 1988. There are now tumor registries in much of the Pacific, with the Tumour Registry of Papua New Guinea, founded in 1958, being the oldest. SEE ALSO: Cancer—Coping with Cancer; Cancer (Gen-
eral).
BIBLIOGRAPHY. Luis Gabriel Cuervo, et al., “Evaluation
of Institutional Cancer Registries in Colombia,” Revista Panamericana de Salud Pública (v.6/3, 1999); J. Geoffrey Golson and Graham A. Colditz, eds., The Encyclopedia of Cancer and Society (SAGE, 2007); E. Lynge, “Danish Cancer Registry as a Resource for Occupational Research,” Journal of Occupational Medicine (v.36/11, 1994); A. E. Okeanov, E. Y. Sosnovskaya, and O. P. Priatkina, “A National Cancer Registry to Assess Trends after the Chernobyl Accident,” Swiss Medical Weekly (v.43/44, 2004); D. M. Parkin, et al., eds., Cancer Incidence in Five Continents, vol. VII (International Agency for Research on Cancer and International Association of Cancer Registries, 1997). Justin Corfield Geelong Grammar School, Australia
Turkey
Tunisia This north African country, which borders Algeria to the west, and Libya to the east, was a part of the Ottoman Empire administered by the Bey of Tunis. In 1883 it became a French protectorate, being occupied by the Axis powers from 1940 until 1943. It then returned to French rule and became independent on March 20, 1956. It has a population of 9,925,000 (2003), and has 70 doctors and 286 nurses per 100,000 people. During the period of Ottoman rule, Tunis was a wealthy city, and a center of great learning. Some doctors did use the work of the Arab surgeon Avicenna (980-1037), but these facilities were only available to the elite. During French colonial rule, healthcare service for the European population, and the local elite was relatively good, although many of the Arabs were unable to get treatment in hospitals. The Institut Pasteur de Tunis (“Pasteur Institute of Tunis”) was founded in 1893. With independence, the new Tunisian government significantly increased the expenditure on healthcare services, and gradually introduced the National Social Security Fund which helps provide benefits when people were sick, women required maternity leave, or in case of death or retirement. Healthcare was generally provided at a local level, but there are still shortages in some prescription medicines, although pharmacies are well-stocked with basic products. Although doctors in the country were traditionally trained in France, the University of Science, Technology and Medicine of Tunis (University of Tunis II) was refounded in 1988 from existing faculties of medicine and science. Most of the healthcare concerns have been connected with illnesses and conditions that arose from poor hygiene and sanitation, such as cholera, typhoid and tuberculosis. However major hygiene campaigns have resulted in the prevalence of cholera, typhoid and tuberculosis being massively reduced. Foreigners and tourists visiting the country tend to suffer most from sunburn and diarrhea. In recent years there has been an increase in the number of people suffering from cancer, with the Association de Lutte Contre le Cancer (“Association for the Fight against Cancer”) was created by the Ministry of the Interior in 1987. It has since been renamed the Association Tunisienne Contre le Cancer (A.T.C.C.: “Tunisian Anti-Cancer Association”).
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SEE ALSO: Cholera; Healthcare, Africa; Tuberculosis; Ty-
phoid.
BIBLIOGRAPHY. Nancy E. Gallagher, “The Arab Medical Or-
ganization in Nineteenth Century Tunisia,” Revue d’Histoire Maghrebine (no.4, July 1975); Nancy E. Gallagher, Medicine and Power in Tunisia (Cambridge University Press, 1983).
Justin Corfield Geelong Grammar School, Australia
Turkey This Middle Eastern country, in what was formerly known as the “Near East,” has traditionally been centered on the city of Byzantium or Constantinople (now Istanbul). This city served as the capital of the Byzantine Empire which controlled the eastern half of the Roman Empire. Although Constantinople was never captured by them, much of Asia Minor became part of the dominions of the Seljuk Turks, and in 1453 the Ottoman Turks took the city, making it the capital of their empire which controlled much of the Middle East and the Balkans. Their power declined in the 19th century, and ended in World War I, with the founding, in 1923, of the Republic of Turkey which covered Asia Minor (Anatolia) and a small portion of the European mainland. A number of medical doctors of the Roman Empire came from Asia Minor, with Aresteaus born in Cappadocia, and Galen born at Pergamon. The latter was to have a very important influence in European medicine and medical thinking throughout the Middle Ages. The Byzantines had a relatively advanced system of treating patients, as did the Ottoman Turks. However the system had fallen far behind the medical progress of western Europe by the 19th century. The Crimean War (1853-1856) proved to be the impetus for both an improvement in Western nursing, with the work of Florence Nightingale at the hospital at Scutari in Turkey, as in Turkey itself with the Military Medical School staring course from 1857 with Dr. Charles Edwards remaining in Turkey at the end of the war to treat the Imperial family and lecture. The Turk Tib Cemiyeti (Turkish Medical Society) was founded in 1856 and publishes the Turkish Medical Journal.
1690 Turkmenistan The next great advance in the healthcare services in Turkey was during the 1920s with the founding of the Republic of Turkey. The Turkish Constitution made the government responsible for the improving of public health, and many hospitals and clinics were built in the cities and large towns. The Turkish Neuropsychiatric Society had been founded in 1914; with most of the other medical associations founded after the proclamation of the Republic. The Turkish Electro-Radiographical Society was established in 1924; the Turkish Surgical Society and the Turkish Microbiological Society were both established in 1931; the Turkish Urological Society was established in 1933; the Turkish Tuberculosis Society was established in 1937; and the Turkish Association of Orthopedics and Traumatology was established in 1939. By the 1950s there were programs to improve the medical care in the countryside. The result was a major fall in the prevalence of many diseases during the 1960s and 1970s. A major medical problem in Turkey had been malaria, with up to half the population said to have been suffering from the disease in 1925 when control measures were introduced. These significantly reduced malaria, and in 1942 the Exceptional Malaria Law was enacted which introduced greater measures to prevent the mosquitoes from breeding. By 1971 there were officially only 2,000 people suffering from malaria, although the number grew to 8,600 in 1990. Most of these cases were located in Cukurova and Sanliurfa where the increased use of irrigation channels led to about 100,000 cases of malaria in 1995 resulting in another major government campaign. Malaria is now officially only present in parts of south-eastern Anatolia and also the region from Mersin on the Mediterranean, to the Iraqi border. The many other health problems in the country have included smallpox, cholera and the plague, which have all been eradicated), tuberculosis, cholera (now relatively rare), and leprosy (effectively stamped out but important in late medieval times), as well as infections from bits by snakes, scorpions, bedbugs and ticks. Diphtheria, influenza, pneumonia and whooping cough have also been major problems. Nowadays, there are numerous hospitals in Turkey, some privately run, and others run by the government. In Ankara, the most well-known hospital is the American Hospital, with Istanbul having the French Hospital, the German Hospital, the Italian Hospital,
the International Hospital, the Admiral Bristol Hospital and the Sen Jerj Hospital. There is also an American Hospital in Gaziantep. The country has a population of 73,193,000 (2005), and has 121 doctors and 109 nurses per 100,000 people. Medical services are free for the poor. SEE ALSO: Influenza; Pneumonia; Smallpox. BIBLIOGRAPHY. Feza Gunergun, Medical History in Turkey,
www.ihp.sinica.edu.tw/~medicine/ashm/lectures/Feza. htm (cited August 2007); Richard F. Nyrop et al,. Area Handbook for the Republic of Turkey (The American University, 1973); Nil Sari, “Turkey and Its International Relations in the History of Medicine,” Vesalius: Acta Internationalia Historiae Medicinae (v.7/2, December 2001); Turkey Yearbook (Directorate General of Press and Information). Justin Corfield Geelong Grammar School, Australia
Turkmenistan Turkmenistan is a central Asian country with a coastline on the eastern side of the Caspian Sea. Home of the Turkmens since perhaps 2000 BCE, the region has been conquered by everyone from Alexander the Great to the Russians; in the early 20th Century, it became a Soviet republic. Turkmenistan was one of the last Soviet states to secede in 1991 and has had a somewhat rocky transition to independence. Turkmenistan’s hope for a stable economic future rests in it’s natural gas and hydrocarbon fields, with many believing that the construction of a pipeline stretching from China to the Caspian could break the current export monopoly held by the Russians. The population of Turkmenistan is 5,100,000 and growing at 1.617 percent annually. The birth rate is 25.36 per 1,000 population and the death rate is 6.17 per 1,000. Like most Central Asian states, there is a outflow of citizens looking for better lives abroad, with about three people per 1,000 leaving the country. Median age is 22.3 years, with 40 percent of the population under the age of 15. life expectancy is 65.23 years for males and 71.54 years for females. Gross national income is $1,340, with 12 percent living on under $1 per day, and
58 percent living in poverty. Unemployment is 60 percent, and the average rate of inflation is 329 percent. Statistics on healthcare within Turkmenistan are extremely suspect, according to the European Centre on Health of Societies in Transition (ECOHOST), a London-based research group. According to a detailed 2005 report, healthcare deteriorated dramatically in recent years, as the rule of president-for-life Saparmurat Niyazov has become “increasingly authoritarian.” Figures from the late 1990s indicate mortality rates from communicable diseases in Turkmenistan are six times those of the European Union, accounting for about 4 percent of all deaths. Viral hepatitis rates in 1997 were 22.4 per 100,000 people for hepatitis B and 325 cases per 100,000 for hepatitis A. UNAIDS puts the current adult prevalence rate for HIV/AIDS at 0.1 percent, with between 500-1,000 infections. ECOHOST believes it has evidence that the Turkmen Ministry of Health and Medical Industry has been ordered not to mention tuberculosis, cholera, dysentery, and a number of other communicable diseases. It also believes a 2004 outbreak of plague was concealed by the government. Non-communicable diseases accounts for around 88 percent of deaths in Turkmenistan, with cardiovascular disease as the main cause. In 1994. ischaemic heart disease was the cause of 587 out of every 100,000 deaths, compared with 418 per 100,000 in nearby states and 118 per 100,000 in the European Union. Digestive disease are also a major cause of mortality. Two-thirds of these deaths come from cirrhosis or chronic liver disease, stemming from the high level of viral hepatitis and alcohol abuse. Cancer deaths are low, but this may be as a result of under-reporting. There are few reliable statistics on the current state of women’s and children’s health or mortality in Turkmenistan. The Niyazov government has reduced funding for medical care and increased user fees, pricing most of the poverty-stricken population out of care. On one day in March 2003, Niyazov dismissed 15,000 healthcare workers and replaced them with untrained military conscripts. SEE ALSO: Healthcare, Asia and Oceania; Poverty and
Disease.
Bibliography. Central Intelligence Agency, “Turkmeni-
stan,” CIA World Factbook. www.cia.gov/library/publica-
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tions/the-world-factbook/geos/tx.html (cited July 2007); European Centre on Health of Societies in Transition (ECOHOST), www.lshtm.ac.uk/ecohost/projects/turkmenistan percent20files/Turkmen percent20Policy percent20Brief. pdf (cited July 2007); The Joint United Nations Programme on HIV/AIDS, “Turkmenistan,” www.unaids.org/en/ Regions_Countries/Countries/turkmenistan.asp (cited July 2007); United Nations Children’s Fund, “Turkmenistan—Statistics,” www.unicef.org/infobycountry/Turkmenistan_statistics.html#29 (cited July 2007); World Health Organization, “A Guide to Statistical Information,” www.who. int/whosis/en/index.html (cited July 2007); World Health Organization, “Health Care in Transition: Turkmenistan,” www.euro.who.int/document/e70316.pdf (cited July 2007); World Health Organization, “Highlights on Health: Turkmenistan,” www.euro.who.int/document/E88284.pdf (cited July 2007). Heather K. Michon Independent Scholar
Turner’s Syndrome Turner’s syndrome (TS) is a genetic disorder that is characterized by physical features and absent or incomplete second sex chromosome. Sex is determined by the sex chromosomes of XX for females and XY for males. In TS, the females’ second X chromosome is damaged, incomplete, or absent. This absent X chromosome causes reduced growth and development, infertility, and a risk for many other growth abnormalities. This genetic disorder exclusively affects females. TS inflicts many worldwide with unknown risk factors or causes. In the developing world, the stigma and poor physiological outcomes from this disease cause suffering and loss of quality of life. TS is named after Dr. Henry Turner, who was among the first to describe it in the late 1930s. Dr. Turner practiced internal medicine and first identified a set of common physical features in seven of his patients. He published the data in an article in 1938 effectively being the first to categorize TS. However, TS was not fully defined and discovered until 1959 with the advent of karyotype technology. A karyotype is a detailed picture of chromosomes arranged in a standard format showing the number, size, and shape
1692 Turner’s Syndrome of each for a patient. This method makes TS diagnosis standardized and easier in developing regions with less access to healthcare and advanced technology. Causes TS is not an inherited disorder; with high rates of infertility, the syndrome is rarely passed to offspring. At present, no known racial, ethnic, socioeconomic, regional, or other components are thought to contribute or predispose females to TS. It is not associated with any environmental or genetic disorders or disease. TS appears to occur at random and can affect anyone. Epidemiology TS occurs in approximately one in 2,000 to 2,500 live female births. Approximately 60,000 girls and women are affected in the United States, with approximately 800 new cases being diagnosed annually. Globally, least developed nations are at risk for underdiagnosing or misdiagnosing TS due to poor emphasis and focus on the disease along with inadequate access to healthcare. Some common misdiagnoses of TS can be autoimmune thyroiditis, XY gonadal agenesis syndrome, and others. Presentation The most common signs and symptoms of adult women with TS are short stature and infertility due to ovarian development pathology. Other common physical features can be a shortened or webbed neck, arms that turn out slightly at the elbow, a low hairline in the back of the head, and finger and fingernail abnormalities. A high arched palate and dental issues may also be present to varying degrees and severity. Other major problems with TS patients include cardiovascular, kidney, thyroid, and skeletal bone and joint disorders. Also, ear and hearing disorders can arise with excessive otitis media infections that lead to hearing loss. Inadequate eye alignment, poor vision, cataracts, and red-green color blindness can also be common in girls with TS. In least developed countries, these symptoms are often overlooked and misdiagnosed as mental or physical retardation. This insufficient access to proper healthcare can lead to psychological distress, inadequate coping, maladaptation, and social isolation. Many patients and families can benefit from support groups and ongoing care plans.
Diagnosis TS can be diagnosed prenatally by amniocentesis or chorionic villous sampling. If an ultrasound of the fetus shows a nuchal cystic hygroma, horseshoe kidney, left-sided cardiac anomalies, or nonimmune fetal hydrops, these can be indicative of TS. If the human chorionic gonadotropin (HCG), estradiol or alphafetoprotein (AFP) is elevated during pregnancy, further tests are recommended for the quick diagnosis of TS. Last, neonatal pedal edema suggests a diagnostic evaluation for Turner’s syndrome. Treatment There is no cure for TS; it is a lifelong condition that can affect females with varying degrees and severity. Most women can live long and healthy lives, yet some of the chronic diseases associated with TS can lead to major health disorders. Follow-up medical care lacks significantly for those with TS in the developing world. Treatment includes thorough screening for commonly associated chronic diseases associated with TS. Early preventive care for the major conditions such as cardiovascular, lymphatic, and renal treatment are essential. Furthermore, in childhood, growth hormone therapy is the standard to try to prevent short stature and bone abnormalities. Estrogen replacement therapy can offer varying results. Diet considerations should be made for growing children with TS as they have risk factors for osteoporosis and must ensure adequate daily intake of calcium and vitamin D. As always, patients should avoid obesity as it increases risks for hypertension and diabetes. Many diets in the developing world may be deficient in essential nutrients for those with TS and further aid in the morbidity of the disease. Prognosis Overall prognosis is favorable. Growth hormone therapy can help considerably, but many individuals will not reach average height in development. Turner’s syndrome is not a cause of mental retardation. Life expectancy is slightly shorter than average, but may be improved by treatment of associated chronic illnesses such as obesity and hypertension. Almost all individuals are infertile, but pregnancy with donor embryos is possible. The lack of access to proper diagnosis and care in the developing world can lead to
Typhoid
a low quality of life and an uneducated populous can lead to social isolation. SEE ALSO:� Adolescent Development; Birth Defects; Child
Development; Diabetes; Genetic Disorders; Growth Disorders; Hormone Replacement Therapy. BIBLIOGRAPHY. K. ���������������������������������� Albertsson and W. B. Ranke, eds.,
“Turner Syndrome in a Life Span Perspective: Research and Clinical Aspects,” Proceedings of the 4th International Symposium, Goteborg, Sweden, May 18–21, 1995. John M. Quinn V, M.P.H. University of Illinois at Chicago
Tuvalu Tuvalu is a island nation in the Pacific Ocean, midway between Hawaii and Australia. It is comprised of five atolls and four reef islands, with a total land mass of 26 kilometers (10 miles). Home to less than 12,000 people, Tuvalu is the second-least populated country in the world, next to Vatican City. With its highest point just 5 meters (16 feet) above sea level, Tuvalu is also at risk from rising sea levels. The islands have little clean drinking water, poor soil for agriculture, no natural resources to exploit, and no base for tourism. Most of the paying jobs are in the government sector and the government is heavily reliant on foreign aid. However, Tuvaluans have learned to make use of a thoroughly modern resource: in 1998, the country began selling access to its area code for popular “900” numbers and in 2000 leased its internet domain name “.tv” for $50 million in royalties. The population is 12,000 and growing at 1.543 percent annually. The birth rate is 22.43 per 1,000 and the death rate is seven per 1,000. Median age is 24.9 years. Life expectancy is 66.38 years for males and 70.99 years for females. This is a subsistence economy, based primarily on fishing and farming. Most money that flows into the country comes from Tuvaluans living abroad. With a favorable climate, good sanitation and relatively clean water, not to mention geographical isolation, Tuvalu is free of many of the communicable diseases that affect other developing nations. The World Health Organization notes that the islands do have an “alarmingly high” rate of skin infections, acute respira-
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tory illnesses, and eye infections. There is some malaria and filariasis. Like many of the Pacific Islands, AIDS has not emerged as a health problem, although tuberculosis cases are on the rise. Septic wounds or sores are the leading cause of morbidity, followed by influenza, acute respiratory infections, headaches and coughs. The Ministry of Health lists heart disease as the leading cause of mortality, followed by “senility,” undiagnosed causes, diabetes, and hypoglycemia. The average diet is quite poor. Diabetes affects about 9 percent of the total population. Child mortality is low, with 31 infants and 38 children between the ages of 1 to 5 dying per 1,000. The total fertility rate for women is 2.96 children each, with 32 percent of women using contraception. All births on the islands take place in hospital, and Tuvalu has had no reported maternal deaths in recent years. The Ministry of Health oversees a small medical community of four doctors, two dentists, 30 nurses, 10 midwives, and 42 auxiliary staff. There is one main hospital in Funafuti, with smaller outposts in other communities. Complex cases are usually taken off the islands to Australia or New Zealand. SEE ALSO: Healthcare, Asia and Oceania. Bibliography. Central Intelligence Agency, “Tuvalu,”
www.cia.gov/library/publications/the-world-factbook/ geos/tv.html (cited June 2007); United Nations Children’s Fund, “Tuvalu—Statistics,” www.unicef.org/infobycountry/Tuvalu_statistics.html#28 (cited June 2007); The Joint United Nations Programme on HIV/AIDS, “Tuvalu,” www. unaids.org/en/Regions_Countries/Countries/tuvalu.asp (cited June 2007); World Health Organization, “A Guide to Statistical Information at WHO,” www.who.int/whosis/en/ index.html (cited June 2007); World Health Organization, “WHO Global InfoBase: InfoBase Home Page,” www.who. int/infobase/report.aspx (cited June 2007). Heather K. Michon Independent Scholar
Typhoid Typhoid fever is an infectious disease caused by the bacterium salmonella typhi, which multiplies in the
1694 Typhoid
Dr. Schreiber of San Augustine giving a typhoid innoculation at a rural school, San Augustine County, Texas, in 1943. Although a vaccine is recommended for international travelers from developed countries, it does not provide 100 percent protection against the bacterium.
bloodstream and gets excreted out via the digestive tract. After an incubation period of 10 to 20 days, patients present with persistent high fever, chills, sweating, coughing, lack of appetite, severe headache, low heart rate, constipation, and other symptoms. Sometimes patients also present with small red rash spots on the abdomen and chest. After this first phase, which lasts about a week, a secondary phase begins, symptoms of which can include diarrhea, prolonged fever, and intestinal bleeding in severe cases. Symptoms typically persist for one to three months if the disease is left untreated, and approximately 10 to 30 percent of untreated patients die. Symptoms are similar to those of cholera, dysentery, and malaria, and typhoid can only be positively identified by stool culture. Typhoid is transmitted by ingestion of food or water contaminated with
the feces of an already-infected person, and thus can be avoided by instituting precautions such as careful food preparation standards, hand washing before eating, and sterile water supplies. Refrigeration alone does not kill the salmonella typhi bacterium. Although a vaccine exists and is recommended for international travelers from developed countries, it does not provide 100 percent protection against the bacterium. Patients can remain carriers of the bacterium even after they no longer exhibit symptoms, which poses a significant challenge to disease prevention. Typhoid can be treated with common antibiotics such as ciprofloxin and ampicillin, although drug resistant strains are becoming increasingly common, especially in Southeast Asia. Infected individuals also often have to be intravenously rehydrated. Prompt
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antibiotic treatment can reduce fatalities to approximately 1 percent of all incident cases. Because of improved hygiene standards and water treatment, typhoid, once common in the United States and Europe, is almost absent from industrialized nations, with most incident cases being among travelers who have contracted the disease abroad. Worldwide, approximately 16 to 22 million cases and 220,000 deaths occur annually, and incidence is highest in children and adolescents aged 5 to 19. While the disease is endemic in many developing countries, it is particularly prevalent in Southeast Asia, Latin America, and Asian nations of the former Soviet Union, as well as anywhere where the main water supply is contaminated with raw sewage. Especially given the emergence of multidrug resistant
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strains, the World Health Organization (WHO) recently recommended widespread vaccination among high risk populations in endemic areas. See Also: Disease and Poverty; Infectious Diseases (Gen-
eral); Third World.
BIBLIOGRAPHY. Donald Emmeluth, Typhoid Fever (Dead-
ly Diseases and Epidemics) (Chelsea House Publications, 2004); James N. Parker, The Official Patient’s Sourcebook on Typhoid Fever (Icon Health Publications, 2002); George Rosen, A History of Public Health (Johns Hopkins University Press, 1993). Annie Dude University of Chicago
U Uganda Uganda is located in the heart of East Africa, bounded by Kenya, Sudan, the Democratic Republic of the Congo, Rwanda, and Tanzania. Although landlocked, Uganda does not lack for water. Within its borders are Lake Albert, Lake Edward, Lake George, Lake Kyoga, and the largest, Lake Victoria, which covers most of the southeast corner of the country. It was at Lake Victoria that many epidemiologists believe the AIDS virus first jumped to humans. Villagers along the lakeside suffered from a “wasting disease” beginning in the 1970s, and the first documented case of AIDS was diagnosed there in 1982, only a year after the virus was seen in the United States. AIDS is the leading cause of mortality in Uganda, followed by tuberculosis and malaria. The adult prevalence rate is 6.7 percent, with an estimated 1 million Ugandans currently infected. Since its emergence in the 1980s, more than 2 million Ugandans have been infected, and almost 1 million have already died from the virus. The country has received a great deal of international funding to help combat AIDS, but conflict in the north, poor infrastructure and understaffing has made implementation of education and treatment programs difficult. However, new infections have leveled off somewhat in recent years. The tuberculosis
rate continues to increase, with a prevalence rate of 559 cases per 100,000 people. Malaria, dysentery, cholera, viral hepatitis, and typhoid fever are among the most common diseases to strike Ugandans. Nine million are believed to be at high risk for contracting African sleeping sickness (trypanosomiasis), an often fatal parasitic disease transmitted by the Tsetse fly. In 2001, there was an outbreak of Ebola virus, with around 425 diagnosed cases and 169 deaths. Uganda is in the African meningitis belt, and had a major outbreak in 2006. An ongoing campaign to eradicate Guinea worm infections has been going well. The fertility rate is 6.84 children per woman. Over half of all rural women marry in adolescence and begin childbearing early, and only 20 percent have access to contraceptives. More than half of Uganda’s AIDS cases are women. While 92 percent of women receive some prenatal care, 39 percent give birth without trained attendants, contributing to a high maternal mortality rate of 880 deaths per 100,000 live births. Nationwide, the child mortality rate for children in Uganda is 79 deaths per 1,000 in infants and 136 death per 1,000 in those under 5 years, although these rates are higher in some regions. Acute respiratory disease and malaria is the leading cause. A quarter of children are malnourished. At least 100,000 children under 15 have HIV/AIDS, and there are more than
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1698 Ukraine 2 million orphans living in the country, a figure that is expected to grow to 3.5 million by 2010. Over 1.1 million women and children have been displaced by conflict, most forced to live in some of the 200 refugee camps spread across the country. The Lord’s Resistance Army, a rebel militia operating in the north, has abducted at least 25,000 children since 1986 and forced them to become soldiers. This has led to the phenomena of the “night commuters,” a daily procession of more than 40,000 children from their homes to nearby towns to seek shelter from raiding parties. Government expenditures on health are $6.80 per capita. There is heavy reliance on non-governmental organizations for health services, with 465 of the country’s 1,700 healthcare facilities run by NGOs. These groups have seen their efforts in rural areas hampered by the ongoing violence. Fifty-one percent of rural households have no access to healthcare. SEE ALSO: AIDS; Cholera; Hepatitis; Typhoid. Bibliography. Central Intelligence Agency, “Uganda,” CIA
World Factbook. www.cia.gov/library/publications/theworld-factbook/geos/ug.html (cited July 2007); The Joint United Nations Programme on HIV/AIDS, “Uganda,” www. unaids.org/en/Regions_Countries/Countries/Uganda.asp (cited July 2007); Ministry of Health, Republic of Uganda, “Uganda Ministry of Health Online—Health Infrastructure,” www.health.go.ug/health_units.htm (cited July 2007); United Nations Children’s Fund, “Uganda—Statistics,” www. unicef.org/infobycountry/uganda_statistics.html#28 (cited July 2007); World Health Organization“A guide to statistical information,” www.who.int/whosis/en/index.html (cited July 2007); World Health Organization, “Health Action in Crisis: Uganda,” www.who.int/hac/crises/uga/background/ Uganda_Jan06 percent20_2_.pdf (cited July 2007). Heather K. Michon Independent Scholar
Ukraine Ukraine is located in Eastern Europe, with a shoreline on the northern edge of the Black Sea. In the 10th and 11th centuries the region was the home of the Kievan Rus, a powerful society that created the first
eastern Slavic state. Ukraine enjoyed long periods of sovereignty over the centuries, but in 1920, the region was taken over by the Soviets. Between the 1920s and the 1940s Ukraine lost nearly 16 million people to artificially-created famines and the horrors of World War II. With the collapse of the Soviet Union in 1991, Ukraine re-emerged as an independent nation with a diverse economy, a army of 1 million, and the world’s third largest nuclear arsenal. The transition to representative democracy has been slow. In 2002, the peaceful “Orange Revolution” led to the creation of a reformist government later that year. The population is 46,300,000, but with a birth rate of 9.45 per 1,000 and a death rate of 16.07 per 1,000, the population is declining by 0.675 percent annually. Median age is 39.2 years. Life expectancy is 62.16 years for males and 73.96 years for females. Gross national income is $1,520 per person, with 32 percent defined as living in poverty. The cost of consumer goods rose 117 percent between 1990-2005. Communicable diseases do not play much of a role in the lives of Ukrainians, at least in terms of mortality. Only 2 percent of deaths stem from communicable diseases. The exception is sexually-transmitted diseases. Ukraine has the fastest-growing AIDS epidemic in Europe, spurred in part by rising rates of drug use. The adult prevalence rate is 1.4 percent and climbing, with over 400,000 already infected. Cardiovascular disease is the leading killer in the Ukraine, accounting for 60 percent of all deaths each year. Of that number 40 percent are ischaemic in nature, more than double the European average. Risk factors include widespread use of tobacco and alcohol, high blood pressure, high body mass index, physical inactivity, high cholesterol, and low intake of fruits and vegetables. Diabetes prevalence is low, at 2 percent of the population. The average Ukrainian consumes 4.8 liters of alcohol each year, and alcohol is estimated to play a role in 12 percent of the country’s disease burden. Alcohol is also implicated in the 11 percent mortality rate from external causes such as traffic accidents, accidental poisonings, and violence. The suicide rate in Ukraine is 24 deaths per 100,000. Child mortality in Ukraine is low, with 17 deaths per 1,000 in children under 5. Immunization rates are around 98 percent. Like adults, Ukrainian children are suffering more from “lifestyle” diseases. In one study of
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13-year olds, 5 percent of boys and 3 percent of girls were obese. In a survey of 15-year olds, 19 percent of girls and 29 percent of boys admitted to consuming alcohol at least once a week, and 8 percent of girls and 21 percent of boys said they had smoked pot within the past year. AIDS is spreading quickly among adolescents. The fertility rate is 1.24 children per woman, with 68 percent of women using contraception. All births take place in hospital, and the maternal mortality rate is 35 deaths per 100,000 live births. The Ukrainian healthcare system is large and unwieldy, with too many hospital beds and too much specialization. The lack of organization leads to a duplication of services in some areas and shortfalls in others. Although healthcare is theoretically free, in reality, Ukrainians end up using private healthcare more than public services, paying 96 percent of their expenses out-of-pocket. SEE ALSO: AIDS; Alcohol Consumption; Arteriosclerosis. Bibliography. Central Intelligence Agency, “Ukraine,”
CIA World Factbook. www.cia.gov/library/publications/ the-world-factbook/geos/up.html (cited July 2007); The Joint United Nations Programme on HIV/AIDS, “Ukraine,” www.unaids.org/en/Regions_Countries/Countries/ ukraine.asp (cited July 2007); United Nations Children’s Fund, “Ukraine—Statistics,” www.unicef.org/infobycountry/ ukraine_statistics.html#29 (cited July 2007); World Health Organization, “A Guide to Statistical Information,”www. who.int/whosis/en/index.html (cited July 2007); World Health Organization, “Highlights on Heath in Ukraine, 2005,” www.euro.who.int/document/e88285.pdf (cited July 2007); World Health Organization, “Ukraine: 10 Health Questions about the New EU Neighbors,” www.euro.who. int/Document/E88202_Ukraine.pdf (cited July 2007). Heather K. Michon Independent Scholar
Ulcers Ulcers are open sores of the skin or other parts of the body which range widely in cause and seriousness. Generally, the ulcer is caused by an erosion of the epithelium—the skin is rubbed away by a lesion or
Excessive production of acid by the stomach might be the initial cause of an ulcer or there might have been an infection by a virus.
wound of some sort—and is then perpetuated by an infection or inflammation of some sort and can then become dangerous. Ulcers that remain for a lengthy period (more than one month) or that are present in elderly people may become cancerous and advice from a medical practitioner should be sought. Given the large range of ways in which the human body can interact with the environment and the large number of viral and bacterial agents in the world, it is not surprising that the range and nature of ulcers is likewise very diverse. For example, ulcers that form on the lips, known as cold sores, are generally trivial and result from the presence of a virus. Ulcers that form on the genitalia are often the result of a sexually transmitted disease and are rather more serious. Ulcers that form within the body may have done so at least in part in response to dietary
1700 Ultraviolet Radiation and lifestyle factors and, as a peptic ulcer, may cause considerable discomfort. Bed sores are a type of ulcer which can affect patients who are obliged to lie in bed for lengthy periods. Patients who are physically weak or vulnerable are more likely to suffer from bed sores, which are caused by pressure on the skin. Also, patients who are thin are more likely to suffer from bed sores, which are more properly known as decubitus ulcers. If untreated, bed sores can be painful and can lead to the development of further problems. However, they can be successfully treated through the use of special lubricants or films which protect the affected area and may help to remove small areas of dead tissue. Depending on the degree of development of the ulcers, they may take several months to heal or longer, although this is quite normal. The best form of cure, of course, is prevention and patients can be protected by ensuring that the skin is not subject to excessive stress and is kept cool and dry, without chafing. Exercise on a daily basis is also advisable, although that will depend on the state of health in the person concerned. Peptic ulcers of various types can form in different parts of the digestive tract. Common locations for such ulcers include the duodenum, the stomach, and the esophagus. Excessive production of acid by the stomach might be the initial cause of the ulcer or there might have been infection by a virus such as Helicobacter pylari (or pylori). The latter cause is susceptible to treatment by pharmaceuticals and the former may be reduced in importance by dealing with lifestyle factors such as type and regularity of diet, eliminating smoking, reducing stress, and so forth. Symptoms indicating the presence of such an ulcer includes sudden vomiting, unexpected weight loss, feelings of bloatedness, or rapid appetite loss. Medical practitioners can generally diagnose the presence of an ulcer from these symptoms and confirmation might be sought by use of an esophagogastroduodenoscopy (EDG) test, which introduces a camera into the digestive tract to identify the exact location. Because long-standing ulcers can lead to cancer, it is important to seek medical advice if symptoms are present, especially if they extend over several weeks. Mouth ulcers result from either a minor trauma (accidentally biting the skin or scratching it with solid food) or some chemical or viral agent, such as herpes simplex. Most mouth ulcers may be treated quite sim-
ply, but regular outbreaks might indicate the presence of an immune deficiency or a problem such as Celiac’s disease. Prevention may be sought through a balanced and careful diet and avoiding smoking, alcohol, and other substances that might provoke an ulcer. SEE ALSO: Peptic Ulcer; Skin Diseases (General); Stress. BIBLIOGRAPHY. A. Shai and H. I. Maibach, Wound Healing and Ulcers of the Skin: Diagnosis and Therapy—The Practical Approach (Springer, 2004); Marjorie Walker, Mark Thursz, and Julian Teare, ed., Upper Gastrointestinal Tract: Ulcers and Inflammation (Blackwell Science Inc. 2001).
John Walsh Shinawatra University
Ultraviolet Radiation Research has linked ultraviolet (UV) radiation to both beneficial and harmful effects for cancer. The beneficial effects are related largely to production of vitamin D; the harmful effects are related largely to both freeradical production and immunosuppression. The balance between beneficial and harmful effects depends on many factors, including skin pigmentation, age, genetics, geography, diet, smoking history, and antioxidant status. UVB UVB has two primary effects: stimulating vitamin D production and inducing melanogenesis (tanning). Observational studies of UVB dose and geography have linked solar UVB to reduced risk for about 20 types of cancer. Although some researchers have criticized the observational studies using UVB doses related to geography, such studies have been supported by those in which nonmelanoma skin cancer (NMSC) incidence or mortality rates were used as the index of individual or population UVB irradiance. In an ecological study of cancer mortality rates in Spain, NMSC mortality rates for 1978–93 were inversely correlated with 17 types of cancer, including cutaneous malignant melanoma (CMM). A meta-analysis of diagnosis of a second cancer after diagnosis of NMSC found that there was a reduced risk for half a dozen
types of cancer as long as smoking was included in the analysis. UVB and vitamin D are also beneficial in increasing survival once cancer reaches a detectable stage. Studies in Norway, Massachusetts, and England found that patients diagnosed with several types of common cancers in summer or fall had higher intermediate-term survival rates than those diagnosed in winter or spring. The mechanisms whereby vitamin D reduces cancer risk are well known. They include increased apoptosis (programmed cell death) of defective cells and increased cellular differentiation, attenuation of growth-inducing signals, absorption and metabolism of calcium, and reduction of angiogenesis and metastasis. Vitamin D improves immune system response to viral infections that are commonly associated with diseases in winter, and because viruses are implicated in several cancers, this effect appears to be another mechanism for cancer risk reduction. Dose–response relations for serum 25-hydroxyvitamin D3 (calcidiol) level have been developed for breast and colorectal cancer through meta-analyses of observational studies, with the finding that it takes about 1,500 international units (IU) of vitamin D3 per day to reduce the risk of colorectal cancer by 50 percent, but 4,000 IU per day for breast cancer. A study of male health professionals at Harvard University estimated a 29 percent reduction in male cancer deaths for 1,500 IU of vitamin D3 per day. Studies have also suggested that blacks have lower cancer survival rates than whites, all things being equal for cancer stage at discovery and treatment level, because blacks have lower calcidiol levels due to darker skin and lower oral intake of vitamin D3. There are, however, several problems with the UVB/vitamin D/cancer theory. For example, prediagnostic calcidiol levels have little correlation with later diagnosis of prostate cancer, yet the geographic variations of prostate cancer mortality rates are consistent with a beneficial role of solar UVB, and frequent sunburning in youth is strongly correlated with reduced risk. Vitamin D has been found to enhance the immune system response to both bacterial and viral infections, and infectious diseases are most common in winter. Because the geographic variation of prostate cancer mortality rates in the United States appears to be related more to winter-
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time than to summertime solar UVB, it may be that prostate cancer is related largely to infectious diseases in youth. Other cancers with both some risk from viruses and a pronounced latitudinal gradient in mortality rate in the United States are bladder, gastric, ovarian, testicular, and thyroid cancer, as well as Hodgkin’s lymphoma. Another discrepancy involves non-Hodgkin’s lymphoma (NHL). Solar UV doses at low latitudes are correlated with reduced risk, whereas those at higher latitudes are correlated with increased risk. UVB and vitamin D may reduce the risk but UVA increases the risk through systemic immunosuppression. The ratio of solar UVB to UVA varies inversely with latitude. The crossover point appears to be around 35 N. More work is required to confirm this hypothesis. Systemic immunosuppression may also be involved in virallinked cancers that are more common in the South, such as cervical and nasopharyngeal cancer. Skin Cancers The primary concern regarding UV is risk for skin cancers: basal cell carcinoma (BCC), squamous cell carcinoma (SCC), and CMM. A literature review finds that SCC is linked to integrated lifetime UVB irradiance, whereas BCC seems to be related to both UVA and UVB and sunburning, and CMM is linked to sunburning and UVA with some contribution from UVB. The evidence regarding UVA as a risk factor for CMM includes observational studies with respect to latitude for northern Europeans living at different latitudes and trends in skin cancer rates in the United States. Sunscreens sold in the United States before 2007 blocked UVB well but not UVA. The formulation used seems to explain why NMSC mortality rates declined by 30 to 50 percent between 1950 and 1969 and 1970 and 1994 for whites, but CMM mortality rates increased by 50 to 90 percent. The U.S. Food and Drug Administration approved chemicals with stronger UVA blockage in 2006, so the newer sunscreens should provide better UVA blockage. Scots developed a gene that increased risk for CMM about 1,600 years ago, and those with red hair and freckles do not tan well and burn easily and are at increased risk for CMM with UV irradiance. For those who can tan, chronic UV irradiance seems to reduce the risk of CMM if the UV irradiance is not experienced to excess. Melanin protects against CMM
1702 United Arab Emirates by blocking the penetration of UVA and by repairing the damage done by free radicals. Summary Humans evolved in conjunction with solar UV doses, with darker skin leading to longer life in equatorial plains regions, brown skin appropriate for forested tropical regions, and pale skin appropriate for higher latitudes. Constitutive skin pigmentation is a trade-off between protection against free-radical production and folate destruction and vitamin D production. Because many people no longer live where their skin is appropriate for the usual UV doses or do not spend as much time in the sun as our ancestors did, health problems have resulted. Those with pale skin living equatorward of their ancestral homelands are more prone to developing skin cancer but can more easily produce vitamin D3; those living poleward of their ancestral homelands are less prone to skin cancer but more prone to internal cancers and other health problems due to reduced vitamin D production. Publichealth policies and individual strategies for both solar UV irradiance and vitamin D supplementation should be revised to reflect recent research findings. More research is, however, indicated to confirm the observational studies and fine-tune the recommendations. SEE ALSO: Cancer (General); Skin Cancer. BILIOGRAPHY: J.J. Cannell, et al., “Epidemic Influenza and
Vitamin D,” Epidemiology and Infection (v.134, 2006); C.F. Garland, et al., “Rising Trends in Melanoma. An Hypothesis Concerning Sunscreen Effectiveness,” Annals of Epidemiology (v.3, 1993); C.F. Garland, et al., “The Role of Vitamin D in Cancer Prevention,” American Journal of Public Health (v.96, 2006); E. Giovannucci, et al., “Prospective Study of Predictors of Vitamin D Status and Cancer Incidence and Mortality in Men,” Journal of the National Cancer Institute (v.98, 2006); E.D. Gorham, et al., “Optimal Vitamin D Status for Colorectal Cancer Prevention: A Quantitative MetaAnalysis,” American Journal of Preventive Medicine (v.32, 2007); W. B. Grant, “An Ecologic Study of Cancer Mortality Rates in Spain with Respect to Indices of Solar UVB Irradiance and Smoking,” International Journal of Cancer (v.120, 2007); W.B. Grant, “Lower Vitamin-D Production from Solar Ultraviolet-B Irradiance May Explain Some Differences in Cancer Survival Rates,” Journal of the National Medical Association (v.98, 2006); W.B. Grant and C.F. Gar-
land, “The Association of Solar Ultraviolet B (UVB) with Reducing Risk of Cancer: Multifactorial Ecologic Analysis of Geographic Variation in Age-Adjusted Cancer Mortality Rates,” Anticancer Research (v.26, 2006); T.E. Robsahm, et al., Vitamin D3 from Sunlight May Improve the Prognosis of Breast-, Colon- and Prostate Cancer (Norway),” Cancer Causes & Control (v.15, 2004). William B. Grant, Ph.D. Sunlight, Nutrition, and Health Research Center (SUNARC)
United Arab Emirates United Arab Emirates (UAE) is located on the southeast side of the Arabian Peninsula, with its coastline along the Persian Gulf and the Gulf of Oman, and land borders against Saudi Arabia and Oman. It is comprised on seven emirates – Abu Dhabi, Ajman, Dubai, Fujairah, Ras al-Khaimah, Sharjah, and Umm al-Quwain – led by a Supreme Council made up of the hereditary emir of each region. The area was known as the Trucial States or Trucial Oman and governed by the British until 1971, when several of the emirates came together to form the UAE. More than 90 percent of the country is nothing but rolling desert sands, yet the UAE is the richest country in the Arab world, thanks to a seemingly boundless supply of oil and its strategic location on the narrow Straight of Hormuz, separating the Persian Gulf from the Arabian Sea. The population is 4,444,000 and growing at 3.997 percent annually. The birth rate is 16.09 per 1,000 and the death rate is 2.16 per 1,000. However, the migration rate is 26.04 migrants per 1,000. The United Arab Emirates relies on foreigners to do most of the work within the country; almost 74 percent percent of the population age 15–64 are expatriates from South Asia. Only 20 percent of the population are nativeborn Emiratis. Median age is 30.1 years. Life expectancy is 73.16 years for males and 78.35 years for females. Gross national income is $18,060 per person. Unemployment is just 2.4 percent. Eighty-five percent of the population lives in an urban area. UAE suffers a low burden of communicable disease. In 2005, there were just 24 cases of measles,
one case of tetanus, and 87 cases of tuberculosis. All 1,544 diagnosed cases of malaria were “imported” by sick expatriates coming into the country from abroad. Safe water and sanitation is available to all. Immunization rates for children are 98 percent. The rate of HIV/AIDS is under 0.2 percent. Mortality generally follows the pattern of a modern industrial nation: 20.2 percent of all deaths stem from cardiovascular disease, 16 percent from accidents, 19 percent defined as “unknown,” and 6.3 percent from cancers. Main risk factors are smoking and obesity. Cases of hypertension and diabetes are both on the rise. While expatriate workers receive healthcare, it is not on the same level as resident Emiratis, and many illnesses and deaths arise from problems not detected until they are beyond treatment. Expatriate workers are also more likely to suffer from industrial accidents. UAE has invested heavily in improving the lives of mothers and children in the last three decades. Child mortality is extremely low, with nine deaths per 1,000 in children under 5. Immunization is universal, and children are generally well-nourished. There is universal education for both boys and girls. Maternal mortality is also low, at 54 deaths per 100,000 live births. The total fertility rate for Emirati women is 2.43 children, despite the fact that only 28 percent use contraception. Almost all women receive prenatal care and give birth in hospital. Health services in UAE have improved greatly in the past 35 years. When the union of states began in 1971, there were just 7 hospitals. Today there are 30. The number of hospital beds has risen from 700 in 1970 to 4,473 in 2000. In 1970, there were 200 physicians; today, there are 2,350. The government spends $497 per capita on healthcare. Many hospitals are set up from the complex treatments and surgeries, including transplants and other highly specialized treatments. SEE ALSO: Healthcare, Asia and Oceania; Immunization/
Vaccination; Malaria.
Bibliography. Central Intelligence Agency, “United Arab
Emirates,” CIA World Factbook, www.cia.gov/library/publications/the-world-factbook/geos/ae.html (cited June 2007); “Health for all in the United Arab Emirates,” Eastern Mediterranean Health Journal (2000) www.emro.who. int/Publications/EMHJ/0604/28.htm (cited July 2007); The
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Joint United Nations Programme on HIV/AIDS, “United Arab Emirates,” www.unaids.org/en/Regions_Countries/ Countries/united_arab_emirates.asp (cited June 2007); Ministry of Health, United Arab Emirates, www.moh.gov. ae/moh_site/others/health_services.htm (cited July 2007); United Nations Children’s Fund, “United Arab Emirates —Statistics,” www.unicef.org/infobycountry/uae_statistics. html#29 (cited June 2007); World Health Organization, Regional Office for the Eastern Mediterranean, “Country Profiles: United Arab Emirates,” www.emro.who.int/emrinfo/index.asp?Ctry=uae (cited July 2007); World Health Organization, “A Guide to Statistical Information,” www. who.int/whosis/en/index.html (cited July 2007). Heather K. Michon Independent Scholar
United Kingdom The United Kingdom of Great Britain and Northern Ireland is made up of four countries: England, Scotland, Wales, and Northern Ireland. There are also 14 overseas territories under the jurisdiction of the United Kingdom. For the purposes of reviewing healthcare systems, the terms United Kingdom and England are used interchangeably in this article, unless otherwise stated. Before World War II, some British political leaders had already expressed significant concerns about the lack of quality affordable healthcare for the poorer segment of the population. Not long after the war ended, on July 5, 1948, the Minister of Health, Aneurin (aka Nye) Bevan of the Labour Party, established the National Heath System (NHS), one of the first comprehensive healthcare systems created worldwide; advocates believed that not only would this help solve the healthcare problem, but that it was also an important step in rebuilding Britain after World War II. From its inception, the NHS was to be—and has been—funded almost entirely from a taxation system, wherein the rate paid was based upon a person’s income. Moreover, anyone living in England, even if temporarily, was able to receive its benefits, even if the person had not paid into the healthcare system; visitors would also be eligible.
1704 United Kingdom The NHS is still the core of the healthcare system in the United Kingdom, although it has undergone two major reforms. Scotland and Wales also use the term National Health System for their healthcare systems, while Northern Ireland uses the term Health and Care, North Ireland. In England, the NHS is controlled by the Department of Health. Reporting directly to the Department of Health are 10 Strategic Health Authorities, organized by region. The Strategic Health Authorities, in turn, supervise the Primary Care Trusts, which oversee most of the NHS’s budget and are responsible for the healthcare services provided to people living in the country. Although, in 1948, members of both political parties—Labour and Conservative—most likely would have agreed that the current healthcare system did not equitably serve all of their constituents, and although millions of citizens of the era struggled to receive healthcare services, the NHS was not universally well received. Both the Conservative Party and the British Medical Association (BMA) strongly spoke out against the system. Political criticisms often stated that Nye was leading Britain into a socialist system, similar to one that had existed under Adolph Hitler, who had been a main catalyst of the horrific war just fought. Members of the BMA worried that they would lose their independence as physicians, along with their ability to buy and sell practices, and they expressed concern that their incomes would severely drop. When the NHS initially became the official healthcare system of the United Kingdom, members of the BMA refused to cooperate or negotiate details with the government. For two years, debate was significant; a partial breakthrough was achieved when Bevan allowed members of the BMA to treat patients within the NHS and still treat private patients. On the two-year anniversary of the NHS, 90 percent of the BMA physicians were operating within the system. Ultimately, though, the members did lose their ability to buy and sell medical practices. The creation of the NHS coincided with rapid innovations in health technology and pharmaceutical development; antibiotics, improved anesthetics, cortisone, drugs for mental illness, and antihistamines were approved, and radiology technology continued to advance. Significant medical advances were occurring in the fight against tuberculosis and other infectious diseases as well. Although this boded well
for improved healthcare, it also escalated the operating costs of the NHS from its inception. To add to this financial burden, the cost of new and improved medical treatments for heart and lung diseases and hip replacements—many of which were never even considered as possible during the decades leading up to the founding of the NHS—caused the NHS operational costs to skyrocket. Within three years, minor fees began to be charged for patients for some services to offset the costs of the NHS. For example, people needing prescription medicines were charged 1s (shilling), starting in 1952, while dental visits began costing patients £1. Initially, the NHS was divided into three sections: one for hospital services; another for family doctors, dentists, opticians, and pharmacists, all of whom were still self-employed but under contract with the NHS; and the third for local health services, which included maternity care, infant wellness, communitybased nursing, immunizations, and infectious disease prevention, control, and treatment. District hospitals were established in geographic centers to provide more routine healthcare services, while university hospitals handled more complex matters. Physicians were the first to see patients, and they referred patients to hospitals, as necessary. During the first four decades of this healthcare program, the NHS system was refined and modified as problems occurred, but the system was not subjected to a major overhaul during this period. During the late 1980s, however, because of growing financial constraints, longer waiting lists ,and massive managerial responsibilities and bureaucracies, the British government under the Conservative Party commissioned the “1989 White Paper, Working for Patients,” which was translated into law in 1990 with the NHS and Community Care Act. Under this law, health authorities stopped directly managing hospitals and coordinating healthcare services; instead, they gave operational funding to the independently run NHS trusts, which created an atmosphere wherein competition could provide more choice to patients and, it was hoped, inequities would be corrected. By 1995, the NHS trust system was entirely in place. Some physicians were also given budgets along with the authority to purchase healthcare services from the NHS structure and private healthcare entities; this was called GP (general practitioner) fund
holding. It was found that physicians who participated in this system could access healthcare services for their patients more quickly than those who elected not to do so, bringing about criticism that the healthcare system was once again inequitable and two-tiered, divided between the have and the have-not populations. Another criticism of this reform was that it brought about duplication in services. After the Labour Party came back into power in 1997, it attempted to correct the perceived flaws; therefore, a third method of running the NHS came into effect. Based on recommendations from another commissioned white paper, “The New NSH: Modern, Dependable,” new reforms emphasized the importance of partnership in healthcare services, with collaboration rather than competition seen as the key to success. Research also seemed to point out to an underfunding of the entire healthcare system and this new round of reforms attempted to address that deficiency. Because of this latest reform, the collection rates and disbursement methods of NHS funds has been changing and evolving during the first several years of the 21st century; in 2000, NHS was earmarked to receive 6.8 percent of the government’s budget, compared to an average of 8 percent in comparable healthcare systems funded across Europe. Since then, the funding has been increasing at a rate of 7.4 percent a year; at this accelerated rate, the amount of funds going to the NHS will have tripled by 2008, bringing the healthcare funding in England on par with Germany and France, two of the European countries spending the most on healthcare services. With this increase in funding, physicians in England are becoming among the best paid in Europe, with nurses and consultants also negotiating more favorable contracts. The budget for 2006–2007 is approximately £96 million. Since 2000, the number of people employed by the NHS has increased from 1 million to 1.4 million, making it the fifth largest organization in the world (first is the Chinese People’s Liberation Army at 2.3 million; the U. S. Department of Defense comes in second at 2 million; the Indian Railways and Wal-Mart, each at 1.5 million, tie for third (and fourth); and then the NHS at fifth). Some critics say that the system is still understaffed and that 10,000 more physicians will be needed to fulfill the upcoming needs, but the head of the NHS calls the service the largest army in the world doing good. He also ironically noted that if all the McDon-
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alds in the world were considered a single organization, their 12 million employees would easily make the fast food establishment the world’s largest organization. In October 2006, the number of Primary Care Trusts was slashed approximately in half to 152, and these organizations have been charged with overseeing the physicians, dentists, and hospitals in their newly defined regions; recently, a greater part of funding control has been passed on to the physicians as part of an initiative to move even more healthcare services outside of the hospitals. It is also expected that hospital consultants will spend increasing amounts of time working in outreach programs to further reduce hospital stays. Just as there was opposition to the NHS program when it began, there is now opposition to the shift away from hospital care in the 21st century. Concerns currently exist over what some see as a move away from a publicly funded/governmentally funded healthcare system. Advocates for a return to the pre– 2000 system state that jobs are being cut in hospitals
The National Health System in the United Kingdom is shifting away from hospital care in the 21st century.
1706 United Kingdom and services are being farmed out to private, for-profit companies that have shareholders outside of the United Kingdom. Those who oppose the latest evolution of the NHS state that this reform is fragmenting the healthcare system, and as a consequence, reducing the accountability of healthcare providers. Numbered among the critics are members of the Conservative Party who in 2004 stated that although the party supports the ideals of the NHS, it believes that the current incarnation does not provide comprehensive healthcare or healthcare services that are available to all. It points out that some life-saving drugs are available in parts of England but not in others, and that some patients must wait months for surgery, while approximately 1 million people are waiting for medical treatment. This, the Conservative Party stated, means that only those able to pay for private care above and beyond the taxes they pay into the NHS can receive appropriate medical treatment. In England, the Department of Health sets the national standards for the NHS and for the social care services that are provided through the NHS, and through other public and private organizations. The Department of Health currently has over 2,000 employees, mostly based in London and Leeds. There are six key objectives for this agency, including one to improve and protect the health of all, including those with financial needs and chronic health conditions. Methods to do so include a review of smoking in public places; continued research in coronary heart disease and cancer, so as to reduce early deaths; working to reduce infectious disease and environmental factors that cause or contribute to disease; and continuing to secure methods to mitigate health pandemics such as the flu. Another objective is to enhance the quality of healthcare services. This will be accomplished, according to Department of Health documents, by providing a choice of healthcare providers; improving speedy access to care; modernizing the ambulance services; developing stronger safeguards and reducing infections in healthcare settings; ensuring cleaner hospitals; and effectively managing pharmaceutical dispensation. A third goal is to provide a better experience for patients, by providing more personal care; by establishing a Health Insight Unit to better understand the needs of the public; and to support the Mental Health Bill being considered by Parliament.
The fourth goal is to improve the capacity of healthcare and social care by simplifying current systems, promoting continued research, using the emerging genetic knowledge and ensuing technology, and improving the funding allocation system. The fifth objective is to continue to support the government and to build up the NHS. The last goal is to cement a positive reputation for the Department of Health, as well as improving the efficiency of the Department. Healthcare accomplishment in England include that breast cancer deaths for British women are dropping faster than anywhere else in the world; the same applies for lung cancer deaths for British men. Although a wait of six months for some hospital treatments may still be criticized as lengthy, this is a significant drop from an 18-month wait experienced during the 1990s. After the most recent NHS reform, the healthcare system contains more elements of independent healthcare services than previous incarnations of the system. The Secretary of State of Health in Britain advocates for the continuing blend of independent healthcare and government funded care and describes this as the rationale behind the independent healthcare sector supplementing the NHS: to increase the capacity for care. Through the use of Independent Sector Treatment Centres (ISTCs), more than 100,000 patients have received care more quickly than was possible through previous strategies. According to the Secretary of State of Health, cataract operations are now performed within three months, a goal reached four years more quickly than anticipated. The ultimate goal is that through a blending of NHS and ISTCs, no one will wait more than 18 weeks from a doctor referral to hospital treatment. Waiting time for magnetic resonance imaging (MRI) has dropped from 20 weeks to 5, according to the Secretary of Health, since the ISTCs have been operating the NHS mobile units. In 2005, ISTCs were treating 3 percent of NHS patients needing routine elective surgery; by 2008, it is anticipated that this figure will reach 10 percent. In Northern Ireland, the Department of Health, Social Services, and Public Safety (DHSSPS) was created in 1999 to administer health and social service legislation for hospitals, physicians, and community health services. The objective is to promote quality health for those living in Northern Ireland. This organization is
also responsible for public safety, which includes fire services, food safety legislation, and emergency/disaster planning. This Department also provides programs to promote healthful activities and lifestyles. This Department is under the jurisdiction of the Permanent Secretary, broken down into several groups: the Planning and Resources Group, Strategic Planning and Modernisation Group, and the Primary, Secondary, and Community Care Group. The Planning and Resources Group handles the financial resources of the Department of Health, Social Services, and Public Safety, as well as the coordination of staffing and information systems. This group oversees ambulance, fire, and emergency services, and it publishes the strategic plan for the overall health service department. The Strategic Planning and Modernisation group (SPMG) is charged with reforming the Health and Personal Social Services (HPSS) structure and programs. Professional groups in the department include Medical and Allied Services, Social Services Inspectorate, Nursing and Midwifery Advisory Group, Dental Services, and Pharmaceutical Advice and Services. The budget for the entire DHSSPS was £3.5 billion during 2005/2006, with 91.9 percent of the funds going to HPSS programming, 1.8 percent to the fire authority, 1.2 percent for administrative expenses, and the remaining 5 percent going to capital expenditures. Northern Ireland has created a Safeguarding Board to centralize social services for children. This agency aims to strengthen community child protection teams and improve social worker training and education. The Scottish Executive Health Department (SEHD) is responsible for the NHS Scotland, which oversees the management of the NHS in the country, as well as the overall development of health policy. The chief executive officer of NHS Scotland is responsible for the efficiency and effectiveness of the healthcare services, which include the Scottish ambulance service; the state hospital for those who need care under special security; NHS Health Scotland, a program that promotes positive attitudes toward healthy lifestyles; and NHS Quality Improvement Scotland, an initiative to set clinical healthcare standards. In 2002, the Scottish NHS employed 143,000 people, which included more than 63,000 nurses, midwives, and health visitors, and more than 3,300 health consultants. More than 13,000 doctors, dentists, op-
United Nations Children’s Fund (UNICEF)
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ticians, and community pharmacists are also allied with the NHS, serving as independent contractors. In Wales, approximately 3 million people use NHS services. The NHS in this country faces significant challenges as some of the residents of Wales are among the poorest in Europe, with a corresponding low health status. Cancer and heart disease rates are high; a significant portion of the country is elderly, with a larger percentage of health conditions; and the combination of urban and rural locales causes challenges for a successful comprehensive healthcare system. The Minister for Health and Social Services is responsible for health and social care in Wales; the Health and Social Services Committee, composed of members of all political parties, helps develop healthcare and social services legislation. SEE ALSO: Healthcare, Europe; Ireland. BIBLIOGRAPHY. Department of Health, www.dh.gov.uk/
Home/fs/en; Patricia Hewitt, “Even Nye Bevan’s NHS Saw a Role for the Private Sector,” The Guardian (July 2, 2005); “Keep Our NHS Public,” www.keepournhspublic.com/index.php (cited March 2007); “Making Britain Better,” BBC News (July 1, 1998); “Short NHS History,” http://www. nhshistory.net/short_history.htm (cited March 2007); “State of the NHS,” BBC News, http://news.bbc.co.uk/2/ shared/spl/hi/guides/456900/456959/html/default.stm (cited March 2007); “UK Conservative Party Health Policy,” Public Health News (June 24, 2004). Kelly Boyer Sagert Independent Scholar
United Nations Children’s Fund (UNICEF) Since the mid-1950s, the United Nations Children’s Fund (UNICEF) has served as the world’s strongest advocate for advancing the health of children around the globe and for protecting children from elements that threaten their lives and well-being. UNICEF reaches children and families in 191 countries and territories, but focuses on 126 developing countries. While UNICEF responds to the needs of all children, most resources are channeled to those who have been victimized by
1708 United Nations Children’s Fund (UNICEF)
UNICEF reaches children and families in 191 countries and territories, but focuses on 126 developing countries.
wars and disasters, those who live in extreme poverty, those who experience violence and/or exploitation, and those who are disabled in some way. Under a mandate from the United Nations (UN) General Assembly and guided by the Convention on the Rights of the Child, UNICEF pursues its mission of protecting children’s rights, helping to meet their basic needs, and expanding opportunities that allow all children to reach their full potential. On a daily basis, UNICEF supports child health and nutrition, safe drinking water and improved sanitation, basic education for both boys and girl, and protecting children from violence, exploitation, and HIV/AIDS. Funding for UNICEF is derived from contributions from individuals, businesses, foundations, and governments. National headquarters, which serves as administrator and policy developer, is located at 3 United Nations Plaza, New York, New York 10017. Information is available by telephone (1-212-326-7000) or on the internet (http://www.unicef.org/). The European regional office is located in Geneva, Switzerland, and the Supply Division is situated in Copenhagen, Denmark. The Innocenti Research Centre is housed in Florence, Italy, and UNICEF maintains offices in Brussels, Belgium, and Tokyo, Japan. Most UNICEF work takes place in individual countries in cooperation with host governments. UNICEF is governed by
a 36-member Executive Board made up of representatives from various countries. The Board is elected by the UN Economic and Social Council. In industrial nations, UNICEF is most visible through the work of 37 National Committees that advocate for children’s rights, conduct fund-raising activities, sell UNICEF greeting cards and products, pursue collaborative partnerships, and support the mission of UNICEF. These committees generate a third of UNICEF’s resources through activities such as Check Out for Children, which allows hotel guests to donate to UNICEF when paying their bills, Change for Good®, which collects leftover foreign money for UNICEF among airline passengers, and Trick or Treat for UNICEF, which allows children in the United States, Canada, Mexico, and Ireland to raise money for UNICEF on Halloween. Each year, approximately 10 million of the world’s children die of preventable conditions such as pneumonia, diarrhea, and malaria. Many other children die in conflict situations or from the HIV/AIDS epidemic that has ravaged populations in countries such as South Africa, India, Nigeria, Zimbabwe, and Tanzania. Currently, some 2.3 million children are living with HIV/AIDS, which has proved fatal to 380,000 children. Some 15 million children have lost one or both parents to the disease. Approximately 300 million children around the globe are regularly subjected to violence, exploitation, and abuse that ranges from beatings and neglect to child labor and forced military service. Female children in many countries are forced to undergo genital mutilation or child marriage. More than 5 million children die each year from malnutrition, poor hygiene, and lack of access to safe water and improved sanitation. Education is considered a basic right of children, and it is the key to improving children’s health in developing countries. UNICEF works to improve access to education for girls as well as boys and teaches individuals and families how to improve their chances of survival. UNICEF’s strategy for saving children’s lives involves vaccinations, antibiotics, micronutrient supplementation, insecticide-treated bed nets, improved breast-feeding practices, and the promotion of good hygiene. SEE ALSO: AIDS; Child Abuse; Child Mental Health; Child
Safety; Childhood Immunization; Refugee Health.
United Network for Organ Sharing (UNOS)
BIBLIOGRAPHY. Maggie Black, Children First: The Story of
UNICEF, Past and Present (Oxford University Press, 1996); Robert L. Heilbroner, Mankind’s Children: The Story of UNICEF (Public Affairs Committee, 1959); Cynthia Needham and Richard Canning, Global Disease Eradication: The Race for the Last Child (ASM Press, 2003); Joyce Brennfleck Shannon, ed., Worldwide Health Sourcebook (Omnigraphics, 2001); Nick Spencer, Poverty and Child Health (Radcliffe Medical, 2000); Judith M. Spiegelman and UNICEF, We Are the Children: A Celebration of UNICEF’s First 40 Years (Atlantic Monthly, 1986); United Nations Children’s Fund, www.unicef.org (cited July 2007). Elizabeth R. Purdy, Ph.D. Independent Scholar
United Network for Organ Sharing (UNOS) The United Network for Organ Sharing (UNOS) focuses on furthering organ availability and transplantation technologies in the United States through education, and technology and policy development. Although UNOS was formed in 1984, the roots of this organization go back to 1968 when the Southeast Organ Procurement Foundation (SEOPF) formed as an organization for transplant professionals and then created the first organ matching system in the United States. In 1984, the National Organ Transplant Act (NOTA) was passed; in response, UNOS branched off from SEOPF, forming its own nonprofit agency dedicated to organ placement. By 1984, successful kidney, kidney/pancreas, liver, pancreas, heart, heart/lung, and lung transplants had already taken place and the need for a central data collection and coordination center became clear. In 1986, the federal government through the U.S. Department of Health and Human Services (HHS) contracted out the Organ Procurement and Transplantation Network (OPTN) to UNOS. To date, UNOS has received all contracts to operate OPTN. Through the OPTN, UNOS collects data about every transplant occurring in the United States, coordinates organ matching and placement, and facilitates discussions with healthcare professionals, donors, and organ recipients to formulate equitable organ transplant policies. Through the OPTN, UNOS has
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created a much more efficient distribution system of deceased organs that allows for fair and timely allocation, formulated a patient waiting list, and set up a system to publicize the need for organ donations. Over the next four years, transplants were successfully completed with intestines and split livers; moreover, the first two successful living donor transplants were completed, one for liver and the other for a lung transplant. In 1992, UNOS created the first comprehensive transplant survival rate report in the United States. The agency also assisted in the formation of Donate Life America to raise public awareness and support of organ donations. Starting in 1995, UNOS has used a Web presence to provide timely information for people interested in transplantation. In 1999, UNOS began using UNet, an internet-based organ matching system; and in 2001, for the first time, living organ donors (6,528) exceeded the number of deceased organ donors (6,081). As of January 2007, 921 organ transplant centers exist in the United States, with kidney transplant centers the most common (249), followed by pancreas (146), heart (135), liver (125), living liver (68), lung (67), heart/ lung (58), intestine (45), and pancreas islet cell (28). UNOS is able to accomplish its work through Organ Procurement Organizations (OPOs) that are located around the country. OPO representatives meet with the families of recently deceased individuals to discuss the possibility of organ donation. They assist in the evaluation of organs, their likelihood of medical use, and if organs are usable, in organ recovery, preservation, and transportation. OPOs also provide educational material about organ donations in their region. When organs are recovered, OPOs first look for suitable local matches; if none are located, then the organs are offered to a broader geographical audience through the UNOS database. SEE ALSO: Organ Donation; Organ Transplantation. BIBLIOGRAPHY. United Network for Organ Sharing, www.
unos.org. (cited July 2007): Pamela A. Mazzeo, Niloo M. Edwards , and Jonathan M. Chen, eds., Cardiac Transplantation: The Columbia University Medical Center/New YorkPresbyterian Hospital Manual (Springer-Verlag, 2004).
Kelly Boyer Sagert Independent Scholar
1710 United States Medical Licensing Examination (USMLE)
United States Medical Licensing Examination (USMLE) The United States Medical Licensing Examination (USMLE) is a test that provides state medical boards across the country with a tool to determine whether to grant an individual a license to practice medicine in a particular state. Throughout the United States and its territories, individual state medical licensing boards have the authority to create their own requirements for medical licensure. Nevertheless, the USMLE provides the boards with an important assessment tool. The test is designed to reflect a potential physician’s knowledge and skills, as well as his or her ability to work well with patients. The USMLE is sponsored by the Federation of State Medical Boards (FSMB) of the United States, Inc., and by the National Board of Medical Examiners (NBME). The FSMB represents the 70 medical boards of the United States and its territories, which includes 14 state boards of osteopathic medicine. The goal of FSMB is to improve the quality, safety, and integrity of healthcare through the development of physician licensing standards. The NBME creates examinations and assessment tools for health professionals based upon results of their research on quality ways to evaluate and measure physician standards. The USMLE consists of three steps. Step 1 tests a candidate on his or her understanding of the sciences involved in practicing medicine. This section of the test also evaluates a person’s ability to continue to comprehend scientific principles as he or she evolves so that a physician can continue to learn new methodologies and technologies. Step 2 assesses a person’s ability to apply medical concepts to promote health and prevent disease, and Step 3 tests patient management skills. USMLE officials stress that test results must be considered in combination and that all three parts should be factored into state medical board licensing decisions. The USMLE converts the percentage of test questions answered correctly into a two-digit and a threedigit score, each of which can be used by state medical boards as a tool to determine licensure. The USMLE recommends three-digit passing scores of 185 in Step 1, 182 in Step 2, and 184 in Step 3 (comparable to
scores of 75 on the two-digit scale); this ensures accurate answers in 60 to 70 percent of the questions. In fact, average scores for first-time test takers range from 200 to 220. Students attending medical schools outside of Canada and the United States who wish to practice in these countries must first obtain Educational Commission for Foreign Medical Graduates (ECFMG) certifications. The USMLE has established a Committee on Irregular Behavior that rules on consequences for certain infractions, including bringing cell phones or pagers into the testing facility, falsifying information on USMLE documents, making notes while in the testing facility, or not following the instructions given by test givers. These actions are noted on transcripts and could affect state medical licensing board decisions for those involved. Punishment may also include being banned from taking the USMLE for a stated period of time. SEE ALSO: American Medical Association (AMA); Ameri-
can Medical Women’s Association (AMWA); Medical College Admissions Test (MCAT) BIBLIOGRAPHY. United States Medical Licensing Ex-
amination, www.usmle.org (cited July 2007). Conrad Fischer Kaplan, USMLE Diagnostic Test Flashcards: 200 Diagnoses Every Doctor Should Know (Kaplan Publishing 2007). Kelly Boyer Sagert Independent Scholar
United States Pharmacopeia and National Formulary (USP-NF) The United States Pharmacopeia and National Formulary (USP-NF) is a guidebook that lists current pharmaceutical standards, including those for medicines and dosages, drugs, and dietary supplements; the volume is a combination of the United States Pharmacopeia (USP) and the National Formulary (NF). The United States Federal Food, Drug, and Cosmetics Act lists the
USP-NF as the official manual for all drugs used in the United States and this volume is also used as a quality check for drugs sold worldwide. The USP-NF is written in English, and has been translated into three other languages: Spanish, French, and German. The USP-NF is available in print, online, and on CD. In the future, the print version will be divided into three volumes in both the English and Spanish editions to allow for expanded content. Each volume will have its own table of contents and index for easier usage, as well as a section indicating what changes have been made from previous editions. In all of its formats, the USP-NF contains monographs of each pharmaceutical substance, which include the active ingredients; packing, storing, and labeling requirements; melting range; residue upon ignition; chloride, sulfide, and sulfate content; heavy metal content; and more. USP-NF standards frequently change, in large part because of a continuous review process that occurs among the pharmaceutical industry, USP staff, and the United States government and volunteer scientists. Anyone who wishes to provide input can do so through the Pharmacopeia Forum, the USP journal wherein all public comments are published, along with USP responses to those comments. The USP provides other resources for pharmacists as well, such as the USP Pharmacists’ Pharmacopeia. In this volume, first published in 2005, pharmacists can read reviews of new products, learn about educational opportunities, and read peer-reviewed articles. Other initiatives include the USP Medicare Model Guidelines and the USP Drug Quality and Information Program, a continuing effort to improve drug quality and professional training for pharmacists in developing countries worldwide. Noting that medication errors can cause potentially serious harm to patients, the USP has created two reporting systems wherein such errors can be reported and used to prevent future mistakes. The MEDMARX® allows for anonymous internet-based reporting of medication errors; hospitals can subscribe to this system, learn from errors, and share solutions. The Medication Errors Reporting System is operated in conjunction with the Institute for Safe Medication Practices. With this system, healthcare professionals report errors directly to USP, again anonymously. The USP uses these data to develop professional education programs that aim to prevent similar errors in the
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future. This organization also publishes patient safety newsletters and works with the government to improve drug safety standards. The USP belongs to the National Coordinating Council for Medication Error Reporting and Prevention (NCC MERP), an organization that they helped found. Twenty-three national healthcare organizations belong to NCC MERP, using an interdisciplinary approach to promoting safe use of medications. SEE ALSO: Drug and Medical Device Safety; Pharmacist;
Pharmacopeia/Pharmacopoeia; Pharmacy.
BIBLIOGRAPHY. National Coordinating Council for Medi-
cation Error Reporting and Prevention (NCC MERP), www.nccmerp.org; United States Pharmacopeia and National Formulary (USP-NF), www.usp.org/USPNF (cited July 2007)..
Kelly Boyer Sagert Independent Scholar
United States Public Health Service Congress created the first public health service organization in the United States in 1798 to care for merchant seamen who were ill or who had been injured. In order to accomplish this task, public hospitals were first built along the East Coast. Others followed in the Great Lakes region, on the Gulf and Pacific Coasts, and along some inland waterways. In 1870, those hospitals were consolidated into the Marine Hospital Service, headquartered in Washington, D.C. The following year, the position of Supervising Surgeon, which evolved into the Surgeon General, assumed administrative authority over the service. Operations were organized along military lines, and the Commissioned Corps was validated in 1889, ultimately serving as the uniformed branch of Health and Human Services and as one of the seven uniformed branches of the United States. Currently, the Public Health Service Commissioned Corps employs physicians, dentists, therapists, veterinarians, dieticians, engineers, pharmacists, nurses, sanitarians, scientists, and a host of professionals who specialize in areas such as environmental health and health services.
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United States Statistics
The Public Health Service, which is part of the Department of Health and Human Services (DHHS), is composed of the Office of Public Health and Science, headed by the Assistant Secretary for Health. The Surgeon General, who is head of the Commissioned Corps, is also housed in this office, located at 5600 Fishers Lane, Rockville, Maryland 20857. Information on the Public Health Service is available by telephone (1-877696-6885) or on the internet (www.usphs.gov/). Ten regional Health Administrators and eight operating divisions complete the Public Health Service team. The research arm of the Public Health Service is the Cooperative Research and Development Agency (CRADA), which works with other federal laboratories, state and local governments, universities, and the private sector to expand knowledge of public health through the sharing and dissemination of information. By the late 19th century, Public Health Service had been charged with inspecting immigrants upon arrival in the United States and with supervising quarantines during outbreaks of infectious diseases. In 1902, responsibilities were expanded, and the name of the service was changed to Public Health and Marine Hospital Service. Ten years later, the service assumed its current identity as Public Health Service. The Commissioned Corps continued to play a major role in containing infectious diseases such as smallpox and yellow fever and began conducting biomedical research, regulating food and drugs, providing health services to underserved groups, and supplying medical assistance in the wake of disasters. Under the leadership of the Surgeon General, the 6,000 officers in the Commissioned Corps pursue their mission of protecting, promoting, and advancing the health and the safety of all people in the United States. This mission is carried out by immediately responding to public health needs, providing leadership in the public health field, and enhancing public health as a science. Specific Corps programs are geared toward providing public health services to underserved populations such as Native Americans and Alaskans and to populations with special needs. Public Health Service activities include disease control and prevention, identifying and correcting health hazards, and promoting healthy lifestyles and good mental health for all Americans. The Commissioned Corps also has a role in protecting consumers from
unsafe foods, drugs, medical devices, cosmetics, and products that contain radiation. At the international level, Public Health Service cooperates with foreign governments and international agencies to promote optimal global health. SEE ALSO: Department of Health and Human Services
(DHHS); Public Health.
BIBLIOGRAPHY. James T. Bennett and Thomas J.
DiLorenzo, From Pathology to Politics: Public Health in America (Transaction, 2000); Sarah Curtis and Ann Taket, Health and Societies: Changing Perspectives (Edward Arnold, 1996); James A. Harrell, et al., Healthy People 2000: Public Health Service Action (U.S. Department of Health and Human Services, 1992); Judith Walzer Leavitt and Ronald L. Numbers, eds., Sickness and Health in America: Readings in the History of Medicine and Public Health (University of Wisconsin Press, 1997); Neil Schneiderman, Integrating Behavioral and Social Sciences with Public Health (American Psychological Association, 2001); United States Public Health Service, www.usphs.gov (cited July 2007). Elizabeth R. Purdy, Ph.D. Independent Scholar
United States Statistics The following is a a state by state anaylsis of health conditions in the United States: Alabama (2005: ranked 45th for quality of health; ranked 43rd in 2004) Almost 80 percent of women in Alabama have received adequate prenatal care and 82.3 percent of children (aged 19 to 35 months) have received complete immunizations. Almost 14 percent of Alabama residents do not have health insurance, down from 16.9 percent in 1990. Top challenges include obesity (28.8 percent of the population), high poverty rates of children (24.2 percent, an increase from 22.3 in 2004), and a high premature death rate. Infant mortality rates range from 6.8 deaths per 1,000 live births for non-Hispanic whites to 14.7 deaths per 1,000 for non-Hispanic blacks.
Alaska (2005: ranked 30th for quality of health; ranked 24th in 2004) Only 12.0 percent of children live in poverty; there is a low total mortality rate at 795.4 deaths per 100,000 people; and cardiovascular-related deaths number only 275.1 per 100,000. The percentage of uninsured residents dropped from 18.9 percent in 2004 to 17 percent in 2005. Access to quality prenatal care is somewhat limited, with 66.5 percent of women receiving adequate care. Only 75.3 percent of children (aged 19 to 35 months) have received a complete set of immunizations, down from 79.7 percent in 2004. Only 60.7 percent of ninth graders have been graduating from high school. More than 24 percent of the population smoke. Arizona (2005: ranked 31st for quality of health; ranked 23rd in 2004) Only 18.5 percent of the population smoke, down from 29.5 percent in 1990 and 20.8 percent in 2004. There is a low rate of cancer deaths (184.5 deaths per 100,000), cardiovascular deaths (287.1 per 100,000), and low work-related fatalities (4.1 deaths per 100,000 workers). Only 68.5 percent of women have received adequate prenatal care and the rate of children living in poverty has increased from 19.1 percent in 2004 to 21.1 percent in 2005. Arkansas (2005: ranked 47th for quality of health; ranked 46th in 2004) More than 82 percent of children (aged 19 to 35 months) have received complete immunizations, up from 76.5 percent in 2004, and 74.2 percent of ninth graders go on to graduate within four years. Children living in poverty declined from 26.8 percent in 2004 to 21.8 percent in 2005. Infectious disease is low at 17.8 cases per 100,000 people, down from 37 cases per 100,000 in 1990. Significant percentages (25.5 percent) of residents smoke and are obese (26 percent), up from 13.2 percent in 1990. California (2005: ranked 22nd for quality of health, ranked same in 2004) A low percentage of residents smoke (14.7), down from 16.8 percent in 2004 and 25.6 percent in 1990. The percentage of children (aged 19 to 35 months) with complete immunizations is 81.3 percent, up from 77.4 percent in 2004. Cancer deaths are low at
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191.9 per 100,000 people. Infant mortality is at 4.9 deaths per 1,000 live births, down from 9.0 in 1990. Over 18 percent of residents do not have health insurance and infectious diseases affect 26.7 out of every 100,000 people. Violent crime affects 552 out of 100,000 people. Colorado (2005: ranked 17th for quality of health; ranked 13th in 2004) Obesity rates are low (16.7 percent) as are cardiovascular deaths (274.7 per 100,000 people) and deaths from cancer (180.1 per 100,000). Children living in poverty declined from 21.8 percent in 1990 to 11.7 percent in 2005, while complete immunizations increased from 67.5 percent in 2004 to 77.1 percent in 2005. Smoking decreased from 28.6 percent of the population in 1990 to 20 percent in 2005. The percentage of uninsured residents increased from 12.8 percent in 1990 to 17 percent in 2005. Only 68.2 percent of women received adequate prenatal care. Connecticut (2005: ranked 7th for quality of health; ranked 8th in 2004) Complete immunization for children aged 19 to 35 months is high (87.8 percent). Smoking is low at 18 percent, obesity is low at 19.5 percent, and 84.1 percent of pregnant women receive adequate prenatal care. Infectious disease rates are high at 25.5 cases per 100,000 of the population. Children living in poverty increased from 10.1 percent in 2004 to 12.2 percent in 2005 and increasing percentages of residents are uninsured (6.4 percent in 1990 to 11.6 percent in 2005). Infant mortality ranges from 4.9 deaths per 1,000 live births for non-Hispanic whites to 14.3 deaths per 1,000 live births for nonHispanic blacks. Delaware (2005: ranked 33rd for quality of health; ranked 32nd in 2004) There is high immunization coverage for children aged 19 to 35 months (86 percent) and a low obesity rate (21 percent, down from 24 percent from 2004). Infectious disease rates are high at 30.8 cases per 100,000 of population. Infant mortality rates are high (8.1 deaths per 1,000 live births), but a decrease from 11.6 deaths per 1,000 live births in 1990 is noted. During the same time frame, the rate of uninsured rose from 9.1 percent to 14.5 percent. Children living
1714
United States Statistics
in poverty rose from 11 percent in 2004 to 13 percent in 2005. Florida (2005: ranked 40th for quality of health; ranked 42nd in 2004) High complete immunization rates are noted at 88.5 percent, up from 81 percent in 2004. Cancer death rates are low at 193.1 per 100,000 of the population and an overall mortality rate is also low at 808.8 deaths per 100,000 people. Smoking decreased from 23.9 percent in 2004 to 20.2 percent in 2005 and children living in poverty decreased from 25.4 percent in 1990 to 17 percent in 2005. The rate of uninsured residents is high (19.9 percent) as is infectious diseases (43 cases per 100,000 of the population). Georgia (2005: ranked 43rd for quality of health; ranked 45th in 2004) Strengths include low smoking rates at 19.9 percent, down from 22.8 percent in 2004 and 31.8 percent in 1990; and high complete immunizations at 84.7 percent, up from 76.6 percent in 2004. The percentage of children living in poverty increased from 17.7 percent in 2004 to 19.9 percent in 2005. Infectious disease rates are high (37.7 cases per 100,000 of the population), as is the percentage of uninsured residents (17.4 percent) and infant mortality rates (8.5 deaths per 1,000 live births). Hawaii (2005: ranked 5th for quality of health; ranked 4th in 2004) Strengths include a low percentage of smokers (17.2 percent); a low percentage of uninsured residents (9.6 percent) and children living in poverty (9.6 percent in 2005, down from 12 percent in 2004 and 20.7 percent in 1990); low rate of cardiovascular deaths (250.8 per 100,000 of the population) and cancer deaths (166.5 deaths per 100,000); and an overall low mortality rate (680.2 deaths per 100,000). Only 67.7 percent of women received adequate prenatal care and obesity increased from 16.4 percent in 2004 to 20.9 percent in 2005. Idaho (2005: ranked 16th for quality of health; ranked 18th in 2004) Smoking rates are low (17.4 percent) and infectious disease rates are low at 4.9 cases per 100,000 of the population, down from 38.8 cases per 100,000 in 1990. Obesity rates are lower than most states (20.8 percent) and cancer deaths are low (186.4 deaths per 100,000
of the population). The rate of uninsured residents decreased from 18.6 percent in 2004 to 15.4 percent in 2005. The complete immunization rate is moderate (80.6 percent of children aged 19 to 35 months). Illinois (2005: ranked 28th for quality of health; ranked 29th in 2004) There is a high rate of complete immunization coverage (82.7 percent); smoking decreased from 24.3 percent in 2004 to 22.2 percent in 2005; and the infant mortality rate decreased from 11.9 to 7.2 deaths per 1,000 live births from 1990 to 2005. Although violent crime decreased from 621 to 543 offenses per 100,000 of the population from 2004 to 2005, the rate is still high. Cancer deaths are high at 212.8 per 100,000 of the population. The uninsured population has increased from 10.1 percent to 14 percent from 1990 to 2005. Indiana (2005: ranked 32nd for quality of health; ranked 29th in 2004) Strengths include a low rate of infectious diseases (11.8 cases per 100,000 of the population). Although the smoking rate is high at 24.8 percent, this indicates a decrease from 26.1 percent in 2004. Obesity rates are high at 25.5 percent of the population. Cancer mortality rates are high at 220 deaths per 100,000 of the population and infant mortality is high at 8 deaths per 1,000 live births. Children living in poverty increased from 13.7 percent in 2004 to 18.5 percent in 2005 and the uninsured population increased from 10.9 percent in 1990 to 14.2 percent in 2005. Iowa (2005: ranked 10th for quality of health; ranked 11th in 2004) The uninsured rate is low at 9.5 percent, down from 11.3 percent in 2004. Infectious diseases are also low at 6.4 cases per 100,000 of the population. More than 83 percent of women received adequate prenatal care and complete immunization coverage for children aged 19 to 35 months is high (86.1 percent), up from 81.1 percent in 2004. The obesity rate is high at 23.5 percent, up significantly from 12.8 percent in 1990. Kansas (2005: ranked 23rd for quality of health; ranked 16th in 2004) Strengths include a low rate of uninsured (11.1 percent) and a low rate of smoking at 19.8 percent, down from 30.2 percent in 1990. Infectious diseases are low
with 8.5 cases per 100,000 of the population, down from 10.4 percent in 2004, and 79.1 percent of women received adequate prenatal care. High school graduation rates are high at 75.2 percent. Challenges include low immunization coverage of 77.5 percent and an increase in the children living in poverty (14.5 percent in 2004 to 15.6 percent in 2005). Kentucky (2005: ranked 42nd for quality of health; ranked 39th in 2004) Infectious disease rates are low at 12.7 cases per 100,000 of the population, down from 27.4 percent in 1990. Infant mortality rates are also low (6.2 deaths per 1,000 live births) and 78.4 percent of women received adequate prenatal care. Although smoking rates are high at 27.5 percent, this indicates a decrease from 30.8 percent in 2004. The rate of children living in poverty increased from 18.1 percent in 2004 to 23.8 percent in 2005 and obesity has increased from 12.2 percent to 25.8 percent since 1990. Cancer rates are high at 236.5 deaths per 100,000 of the population. Louisiana (2005: ranked 49th for quality of health; ranked 50th in 2004) More than 80 percent of women received adequate prenatal care. The rate of children living in poverty dropped from 38.5 percent in 1990 to 25.5 percent in 2004 and then 20.6 percent in 2005. From 2004 to 2005, smoking decreased from 26.5 percent to 23.5 percent. Obesity rates are high at 26.9 percent, up from 12.3 percent in 1990. Cancer rates are high at 223.5 deaths per 100,000 of the population. Infant mortality rates are also high at 9.6 deaths per 1,000 live births. Infectious disease rates are high as well, with 32.3 cases per 100,000 of the population. Maine (2005: ranked 8th for quality of health; ranked 10th in 2004) Strengths include a low rate of uninsured (10 percent); access to adequate prenatal care (84.7 percent); low rate of infectious diseases (6.2 cases per 100,000 of the population); low rate of cardiovascular deaths (282.1 deaths per 100,000); and a low infant mortality rate at 5.2 deaths per 1,000 live births, down from 8.5 percent in 1990. Cancer rates are high at 218.8 deaths per 100,000 of the population. Smoking decreased from 23.7 percent in 2004 to 20.0 percent of the population in 2005; obesity increased from 19.9 to 23.3 percent during that
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time frame; and children living in poverty decreased from 21.6 percent in 1990 to 14 percent in 2005. Maryland (2005: ranked 34th for quality of health; ranked same in 2004) Only 19.5 percent of the population smoke, down from 29.7 percent in 1990, and only 11 percent of children live in poverty. The rate of infectious disease, although high at 40.3 cases per 100,000 of the population, is down from 43.9 cases per 100,000 in 2004. Challenges include a high infant mortality rate at 8.7 deaths per 1,000 live births; an increase in obesity from 21.9 percent in 2004 to 23.9 percent in 2005; and an increase in the uninsured population from 8.9 percent in 1990 to 14.6 percent in 2005. Massachusetts (2005: ranked 9th for quality of health; ranked 6th in 2004) Massachusetts ranks in the top 10 states on 10 of the 18 measures used for health rankings. Strengths include an 89.1 percent immunization rate; low infant mortality rate at 4.8 deaths per 1,000 live births; low obesity rate at 18.3 percent; low smoking rate at 18.4 percent, down from 28.2 percent in 1990; and a low percentage of children living in poverty at 10.1 percent, down from 12 percent in 2004 and 18.8 percent in 1990. Challenges include high rates of infectious disease (24.3 cases per 100,000) and cancer deaths (207.8 per 100,000). Michigan (2005: ranked 29th for quality of heath; ranked same in 2004) Michigan has a low rate of uninsured residents (11.6 percent); 80.6 percent of pregnant women received adequate prenatal care; and smoking prevalence dropped from 26.1 percent in 2004 to 23.2 percent in 2005. Challenges include a high rate of obesity (25.4 percent); a high rate of cardiovascular deaths at 359.2 deaths per 100,000 of the population; and a high infant mortality rate (8.2 deaths per 1,000 live births). Children living in poverty increased from 14.6 percent in 2004 to 19.3 percent in 2005. Minnesota (2005: ranked 1st for quality of health; ranked same in 2004) Minnesota ranks as one of the top 10 states in 10 of the 18 measures. Strengths include a low rate of uninsured (8.9 percent); low rate of cardiovascular deaths (248.2 per 100,000 of the population); low infant mortality rate
1716
United States Statistics
at 4.8 deaths per 1,000 live births, down from 8.9 per 1,000 in 1990; and a low premature death rate. Children living in poverty decreased from 21.2 percent in 1990 to 9.7 percent in 2004 to 9 percent in 2005. Challenges include a high rate of smoking (20.7 percent in 2005, down from 28.7 in 1990) and the fact that only 75.8 percent of women received adequate prenatal care. Mississippi (2005: ranked 50th for quality of health; ranked 49th in 2004) Strengths include 81.8 percent of women receiving adequate prenatal care and high immunization coverage (84 percent). Infant mortality rates have decreased from 13 deaths per 1,000 live births in 1990 to 10.2 in 2004 and 9.6 in 2005. Mississippi ranks in the bottom five states on 9 of 18 measures. Challenges include 26.6 percent of children living poverty; a high obesity rate (29.4 percent); high rate of cardiovascular deaths (409.8 deaths per 100,000 of the population); and a high infant mortality rate (9.6 deaths per 1,000 live births). Missouri (2005: ranked 35th for quality of health; ranked 36th in 2004) Almost 82 percent of women received adequate prenatal care and the uninsured populate is low at 12.6 percent. Infectious disease dropped from 25.5 cases per 100,000 in 2004 to 18.4 cases per 100,000 in 2005. Challenges include a high rate of cardiovascular deaths (364.2 per 100,000 of the population); high prevalence of smoking (24 percent); and a high rate of obesity (24.9 percent), up from 11.9 percent in 1990. Montana (2005: ranked 21st for quality of health; ranked 26th in 2004) Strengths include a low rate of infectious diseases at 4.6 cases per 100,000 of the population and a low obesity rate (19.7 percent). Infant mortality has dropped from 9.8 deaths per 1,000 live births in 1990 to 7 deaths in 2004 to 5.6 deaths in 2005; and the percentage of children living in poverty dropped from 20.2 percent in 2004 to 16.5 percent in 2005. Challenges include a low immunization rate (78.2 percent) and a high rate of uninsured population at 19.1 percent. Nebraska (2005: ranked 11th for quality of health; ranked 12th in 2005) Highlights include a low rate of children living in poverty (10.2 percent) and a low rate of uninsured population
(11.4 percent). Since 1990, the rate of infectious disease fell from 11.6 cases per 100,000 of the population to 8.5 in 2005 and, during that time, the infant mortality rate fell from 9.3 deaths per 1,000 live births to 6.2 deaths. Challenges include limited access to prenatal care with only 73.2 percent of women receiving adequate care. Nevada (2005: ranked 37th for quality of health; ranked same in 2004) Strengths include low obesity at 21 percent; a low infant mortality rate (6.2 deaths per 1,000 live births), down from 9.4 per 1,000 in 1990; and a low percentage of children living in poverty (13.8 percent). Infectious disease has dropped from 49.8 cases per 100,000 of the population in 1990 to 23 in 2005. A significant challenge is the low rate of complete immunization coverage with 68.4 percent of children receiving them in 2005, down from 75.7 percent in 2004. The rate of uninsured population is high (18.5 percent). New Hampshire (2005: ranked 3rd for quality of health; ranked 2nd in 2004) Strengths include a low percentage of children living in poverty (7.4 percent); a low infant mortality rate (4.8 deaths per 1,000 live births); and a high rate of women receiving adequate prenatal care (86.7 percent). Challenges include a high rate of smoking (21.6 percent) moderate rate of cancer deaths (202.6 deaths per 100,000 of the population), and an increase of uninsured from 10.3 percent in 2004 to 11.7 percent in 2005. Since 1990, cardiovascular deaths have dropped from 401.6 per 100,000 to 298.1 in 2005. Incidences of infectious disease dropped from 18.3 per 100,000 in 1990 to 8.3 per 100,000 in 2005. New Jersey (2005: ranked 15th for quality of health; ranked 17th in 2004) Strengths include a low percentage of children living in poverty (8.4 percent), down from 11.2 percent in 2004; low rate of smoking (18.8 percent); and a low infant mortality rate (5.3 deaths per 1,000 live births), down from 9.6 deaths per 1,000 live births in 1990. Challenges include limited access to prenatal care, with only 63.4 percent of women receiving adequate care, and a high rate of infectious disease (29.1 cases per 100,000 of the population). Complete immunizations increased from 75 percent in 2004 to 82.7 percent in 2005.
New Mexico (2005: ranked 38th for quality of health; ranked same in 2004) Strengths include a low rate of cardiovascular deaths (272.1 deaths per 100,000 of the population) and of cancer (178.6 deaths per 100,000); a high rate of complete immunizations (83.5 percent), up from 75.2 percent in 2004; and a low obesity rate (21.4 percent). Only 58.4 percent of women received adequate prenatal care, and a high number of children (23.4 percent) live in poverty. Since 1990, the infant mortality rate dropped from 8.8 deaths per 1,000 live births to 5.8, and infectious disease dropped from 64.2 cases per 100,000 of the population to 14.2 cases. New York (2005: ranked 26th for quality of health; ranked 31st in 2004) Strengths include a low rate of cancer deaths (193.2 deaths per 100,000 of the population) and the decreasing rate of smoking (21.6 percent in 2004 to 19.9 percent in 2005). Challenges include a high rate of infectious diseases (46.5 cases per 100,000 of the population), limited access to adequate prenatal care (63.8 percent), and a high percentage of children living in poverty (21.3 percent). Since 1990, the rate of uninsured increased from 10.7 percent to 14.2 percent. North Carolina (2005: ranked 36th for quality of health; ranked 41st in 2004) Strengths include access to adequate prenatal care for 80.8 percent of women and a low rate of cancer deaths at 204.3 deaths per 100,000 of the population. The past year, the percentage of children living in poverty decreased from 23.1 to 19.2 percent, and since 1990, smoking declined from 31.6 to 23.1 percent of the population. Challenges include a high infant mortality rate (8.2 deaths per 1,000 live births) and a drop in complete immunization coverage from 86.7 percent in 2004 to 81.6 percent in 2005. North Dakota (2005: ranked 6th for quality of health; ranked 7th in 2004) Highlights include a low rate of infectious disease at 3.2 cases per 100,000 of the population, down from 11.1 cases per 100,000 in 1990; an infant mortality rate that decreased from 6.9 deaths per 1,000 live births in 2004 to 6 per 1,000 in 2005. Since 1990, children living in poverty declined from 17.3 to 12.1 percent. Challenges include a high obesity rate (24.5
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percent) and limited access to adequate prenatal care (70.5 percent receiving the care). Ohio (2005: ranked 27th for quality of health; ranked 26th in 2004) Strengths include a low rate of uninsured (11.4 percent), down from 12.1 percent in 2004; 80.5 percent of pregnant women receiving quality prenatal care; and low rates of infectious disease (11 cases per 100,000 of the population). Challenges include a high rate of smoking (25.8 percent of the population); high obesity (25.2 percent), up from 11.3 percent in 1990; and a high rate of cardiovascular deaths (354.1 deaths per 100,000). Oklahoma (2005: ranked 44th for quality of health; ranked 40th in 2004) Strengths include a low rate of infectious disease (14.1 cases per 100,000 of the population), down from 34.9 cases per 100,000 in 1990; and the low percentage of children living in poverty (14.1 percent), down from 17 percent in 2004. Challenges include a high rate of cardiovascular deaths (411.1 per 100,000), high prevalence of smoking (26 percent), high rate of an uninsured population (19.9 percent), and low immunization coverage (72.1 percent). Obesity has increased from 11.6 percent in 1990 to 24.8 percent in 2005. Oregon (2005: ranked 18th for quality of health; ranked 21st in 2004) Strengths include a low rate of cardiovascular deaths (296.1 deaths per 100,000 of the population); low obesity rate (21.2 percent); low prevalence of smoking (20 percent); and a decreasing percentage of children living in poverty (20.1 percent in 2004 to 15.6 percent in 2005). Since 1990, the infant mortality rate has dropped from 9.9 deaths per 1,000 live births to 5.7, and the incidences of infectious diseases dropped from 92.8 cases per 100,000 to 16. Challenges include low complete immunization coverage (78.9 percent) and a high rate of an uninsured population (16.5 percent). Pennsylvania (2005: ranked 25th for quality of health; ranked same in 2004) Strengths include a high rate of complete immunization coverage (85.7 percent) and a low rate of an uninsured population at 11.9 percent. The prevalence of smoking decreased from 25.4 percent in 2004 to 22.7 percent in 2005, and the infant mortality rate dropped
1718
United States Statistics
from 10.3 deaths per 1,000 live births in 1990 to 6.8 per 1,000 in 2005. Challenges include a high rate of cancer deaths (211.5 deaths per 100,000 of the population) and of infectious disease (23.9 cases per 100,000). The percentage of children living in poverty increased from 15.5 percent in 2004 to 17.2 percent in 2005. Rhode Island (2005: ranked 12th for quality of health; ranked 14th in 2004) Highlights include 86.4 percent of pregnant women receiving adequate prenatal care; a high immunization rate (86.7 percent); low obesity rate (18.9 percent); a low infant mortality rate at 5.2 deaths per 1,000 live births, down from 5.9 per 1,000 in 2004; and a low rate of an uninsured population (11.4 percent). Since 1990, the smoking prevalence dropped from 34.4 percent to 21.3 percent. Challenges include a high percentage of children living in poverty (18.3 percent), up from 11.7 percent in 1990; and a high rate of cancer deaths (206.5 deaths per 100,000 of the population). South Carolina (2005: ranked 46th for quality of health; ranked 47th in 2004) Strengths include a moderate rate of an uninsured population (14.7 percent); a moderate rate of cancer deaths (206 per 100,000 of the population); moderate access to adequate prenatal care at 74.2 percent; and a declining infant mortality rate, down from 13 deaths per 1,000 live births in 1990 to 8.8 deaths per 100,000 in 2004 and 8.2 per 100,000 in 2005. Children living in poverty increased from 17.4 percent in 2004 to 21 percent in 2005. South Dakota (2005: ranked 20th for quality of health; ranked 19th in 2004) Strengths include a low rate of infectious disease (4 cases per 100,000 of the population) and a high rate of complete immunization coverage at 86.1 percent. The percentage of children living in poverty has increased from 14 percent in 2004 to 18.6 percent in 2005, and the obesity has increased from 10.7 percent in 1990 to 23.8 percent in 2005. Tennessee (2005: ranked 48th for quality of health; ranked same in 2004) Strengths include a high immunization rate in 2005 (82.4 percent), up from 78.8 percent in 2004; access
to adequate prenatal care for 77.9 percent of pregnant women; a low rate of an uninsured population (14.1 percent); and a decrease in infant mortality rates from 9.2 deaths per 1,000 live births in 2004 to 8.8 per 1,000 in 2005. Since 1990, the percentage of children living in poverty decreased from 29.6 to 20.4 percent. Challenges include a high rate of smoking (26.1 percent) and a high rate of cardiovascular deaths (385.4 per 100,000 of the population). Texas (2005: ranked 39th for quality of health; ranked 35th in 2004) Strengths include a low rate of cancer deaths (200.8 per 100,000 of the population); a low infant mortality rate at 6.2 deaths per 1,000 live births, down from 9.3 per 1,000 in 1990; and a decrease of smoking prevalence from 30.6 percent in 1990 to 22.1 percent in 2004 to 20.4 percent in 2005. Challenges include a high rate of an uninsured population (25 percent); a high percentage of children living in poverty (23.3 percent); high rate of obesity (25.7 percent); and a low immunization coverage rate (72.5 percent). Utah (2005: ranked 4th for quality of health; ranked 5th in 2004) Utah ranks among the top 10 states in 11 of 18 measures. Strengths include a low prevalence of smoking (10.4 percent); low rate of cancer deaths (153 per 100,000 of the population); low infant mortality rate (5.1 deaths per 1,000 live births), down from 8.7 per 1,000 in 1990; and low cardiovascular deaths (275.2 deaths per 100,000). Challenges include low immunization coverage (71.3 percent) and the rate of uninsured going from 12.7 percent of the population in 2004 to 14.1 percent in 2005. Vermont (2005: ranked 2nd for quality of health; ranked 3rd in 2004) Vermont ranks among the top 10 states for 11 of the 18 measures. Strengths include 87.4 percent of women receiving quality prenatal care; a low infant mortality rate of 4.7 deaths per 1,000 live births; and the prevalence of smoking decreasing from 30.7 percent in 1990 to 19.9 percent in 2005. Challenges include a modest rate of cancer deaths (203.5 deaths per 100,000 of the population) and an increase in the uninsured population from 9.5 percent in 2004 to 11.2 percent in 2005.
Virginia (2005: ranked 24th for quality of health; ranked 20th in 2004) Strengths include a low percentage of children living in poverty, from 13.5 percent in 2004 to 11.7 percent in 2005. The prevalence of smoking declined from 32.7 percent in 1990 to 20.8 percent in 2005. Challenges include a low complete immunization rate of 81 percent; a high infant mortality rate of 7.3 deaths per 1,000 live births; an increase of the uninsured population from 13 percent in 2004 to 14.4 percent in 2005; and an increase in obesity from 9.9 percent in 1990 to 23 percent in 2005. Washington (2005: ranked 14th for quality of health; ranked 15th in 2004) Strengths include a low prevalence of smoking (19.2 percent); a low infant mortality rate at 5.3 deaths per 1,000 live births, down from 9.7 per 1,000 in 1990; and a decrease in the uninsured population from 15.5 percent in 2004 to 13 percent in 2005. The percentage of children living in poverty declined from 19.1 percent in 2004 to 15.8 percent in 2005, and the rate of infectious disease declined from 84.1 per 100,000 of the population in 1990 to 14.6 per 100,000 in 2005. A challenge is the low complete immunization rate (77.7 percent). West Virginia (2005: ranked 41st for quality of health; ranked 43rd in 2004) Strengths include a high complete immunization rate at 86.6 percent, up from 74.6 percent in 2004; adequate prenatal care for 80.1 percent of pregnant women; and the decrease of children living in poverty from 26.7 percent in 2004 to 18 percent in 2005. Challenges include a high prevalence of smoking (26.8 percent) and high obesity rates (27.6 percent). Wisconsin (2005: ranked 13th for quality of health; ranked 9th in 2004) Strengths include low rates of infectious diseases (7.3 cases per 100,000 of the population); a low rate of uninsured population (10.4 percent, down from 10.9 percent in 2004); a decline in infant mortality from 8.9 deaths per 1,000 live births in 1990 to 6.2 per 1,000 in 2005. Challenges include a high rate of smoking (21.9 percent); the percentage of children living in poverty increasing from 15.4 percent in 2004 to 18 percent in 2005; and the increase of obesity, from 11.3 percent in 1990 to 23.2 percent in 2005.
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Wyoming (2005: ranked 19th for quality in health; ranked 28th in 2004) Strengths include a low rate of obesity (20.7 percent); a low incidence of infectious disease (8.2 case per 100,000 of the population); a decrease in the uninsured population from 15.9 percent in 2004 to 14 percent in 2005; and a decrease in smoking from 31.7 percent in 1990 to 21.7 percent in 2005. Challenges include only 67.5 percent of women receiving adequate prenatal care (67.5 percent) and a high infant mortality rate (8 deaths per 1,000 live births). SEE ALSO: Healthcare, U.S. and Canada; Insurance. BIBLIOGRAPHY. United Health Foundation, America’s Health Rankings, 2005 Edition, www.unitedhealthfoundation.org/shr2005/states/AllStates.html (cited April 2007).
Kelly Boyer Sagert Independent Scholar
Universal Donor A common term given to individuals with blood type O-negative and plasma type AB, these individuals can donate red blood cells or plasma, respectively, to any individual without the risk of a transfusion reaction. However, this term tends to be an exaggeration, as adverse reactions can still occur. The term generally describes the absence of a negative reaction among the recipient. However, the transfused material can incur a negative reaction with the recipient. To complicate the matter, compatibility between donors and recipients of transfused packed red blood cells (PRBCs) is opposite that of fresh frozen plasma (FFP). Universal Donors of PRBCs Individuals with O-negative type blood can theoretically donate blood to a recipient with any blood type. Despite this, there has been evidence that a negative reaction can still occur among the donor’s antibodies and the recipient’s antigens. Thus, the term universal donor generally describes the lack of a reaction between the donor’s antigens and the recipient’s antibodies, although the vice versa is still possible. Exact blood-type matches are preferable
1720 Unsaturated Fat in the hospital setting to limit these types of negative reactions. Universal Donors of FFP The situation when transfusing FFP is opposite that of PRBCs. Recipients with O-type blood can receive FFP only from donors with O-type blood. In this case, the “universal donors” of FFP are those with AB-type blood, not O-type as in the case with PRBCs. The term universal donor has generally been used to describe donors whose blood is compatible with any recipient. Despite the fact that the term is not wholly accurate or inclusive, the term helps the public understand the process behind donating blood and who the donated blood is best suited for. SEE ALSO: Blood/Blood Transfusion; Hematology. BIBLIOGRAPHY. American Red Cross, www.givelife.org (cited July 2007); Lorri A. Zipperer, ed., The Health Care Almanac: A Resource Guide to the Medical Field (American Medical Association, 1995).
Bradley E. Goldstein, M.S., M.P.H. Lake Erie College of Osteopathic Medicine
Unsaturated Fat Unsaturated fats are hydrocarbon molecules that have two carbons which share double or triple bond(s) and are therefore not completely saturated with hydrogen atoms. Due to the decreased saturation with hydrogen bonds, the structures are weaker and are, therefore, typically liquids (oil) at room temperature. Unsaturated fats are more likely found in vegetables as well as in fish. The aforementioned is in contrast to saturated fats which are typically found more often in meat products and are solid at room temperature. Eating more unsaturated fats and less saturated fat (such as butter) can help lower cholesterol and heartrelated health risks by lowering the bad cholesterol (low-density lipoprotein [LDL]) even though the average person makes about 75 percent of cholesterol in his or her liver and only about 25 percent is obtained from the diet. The most important influence on the blood cholesterol level is the actual mix of different types of
Unsaturated fats are an important supply of calories and, therefore, an important source of energy for the human body.
cholesterol in the diet. A diet with more unsaturated versus saturated fats is important because unsaturated fats are necessary for the body and they also protect against illness. The American Heart Association recommends a moderate intake of all types of fats. There are two main types of the unsaturated fats: monounsaturated and polyunsaturated. Monounsaturated fats (such as olive, peanut, and canola oils) have one double bond present per molecule. Oils high in monounsaturated fats are better oils for cooking. Olive oil, in particular, has been deemed the best oil for cooking because it remains stable at higher temperatures and does not easily become hydrogenated or saturated. Monounsaturated fats are considered the healthiest types of fats because they lower total cholesterol, lower bad cholesterol, and lower triglycerides (the amount of fat circulating in the blood). Polyunsaturated fats have more than one double bond and are more likely to be found in fish, especially salmon, soy beans, mayonnaise, soft margarine, and fish oil. They provide essential fatty acids for healthy skin and the development of body cells. Unsaturated fats are an important supply of calories and, therefore, energy to the human body. In general, fats are made of carbon, hydrogen, and oxygen and are the most concentrated source of energy in
Urinary Tract Infections
food. Fats along with protein and carbohydrates are the three main nutrients present in food. Fats are categorized according to their percentage of hydrogen bonds as saturated (all hydrogen bonds) or unsaturated fats (not all hydrogen bonds). SEE ALSO: Dieting; Heart Attack; Heart Diseases—Pre-
vention; Lean Body Mass; Obesity.
BIBLIOGRAPHY. American Heart Association, www.amer-
icanheart.org (cited July 2007); “Dietary Guidelines for Healthy American Adults: A Statement for Health Professionals by the Nutrition Committee, American Heart Association,” Circulation (v.94,1996); P. M. Kris-Etherton, et al., “High-Monounsaturated Fatty Acid Diets Lower Both Plasma Cholesterol and Triacylglycerol Concentrations,” AJCN (v.70, 1999). Lisa Aenlle, M.P.H. Michigan State University
Urinary Tract Infections Infections of the urinary tract are the most common of all bacterial infections, and cause significant morbidity worldwide. The urinary system consists of the kidneys, ureters, prostate (in men), bladder, and urethra. On a daily basis, there is large variability in the amount and type of food and fluids that are consumed. The kidneys play a large role in maintaining fluid and electrolyte balance. Urine is produced by the kidneys as a result of filtration of the blood that passes through the kidneys. This urine travels through the ureter to the bladder, and together, the kidneys and bladder are considered the upper urinary tract. Infection of the kidneys and prostate are termed pyelonephritis and prostatitis, respectively. The lower urinary tract consists of the bladder as well as the urethra, which is the organ that allows for excretion of urine from the bladder to outside of the body. Infection of the bladder and urethra are termed cystitis and urethritis, respectively. Both the upper and the lower urinary tracts can be infected with a variety of organisms, producing different symp-
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toms and consequences, and requiring different treatments. Urinary tract infections (UTIs) are frequently defined by detection of pathogenic microorganisms in the urine, urethra, bladder, kidney, or prostate. When a sample of urine is appropriately collected and cultured, the growth of more than 105 organisms from 1 milliliter of urine is considered an infection. However, if a patient is experiencing symptoms of an UTI, then there is often a lower threshold to the number of bacteria that need to be present to diagnose and infection. Bacteria can enter the urinary system from direct entry through the urethra, or they can be introduced as a consequence of catheter insertion or a surgical procedure. Epidemiology Infections of the urinary tract are more common in women than in men, except when individuals are very young or old. Up to 80 percent of women will experience a UTI, most often cystitis, at some point in their lives. This high number is thought to be due to the shorter urethra (4 centimeters) in women as compared to men. Approximately onequarter of women who have had one UTI will have a recurrent infection. Women are also at increased risk of pyelonephritis. Factors associated with pyelonephritis in women include frequency of sexual intercourse, a new sexual partner, UTI in the past year, history of UTI in the patient’s mother, diabetes, and incontinence. Women with diabetes also have an increased risk of UTIs. The incidence of UTIs in women is further increased during pregnancy. Up to 10 percent of pregnant women are found to have bacteria in their urine although they are asymptomatic. If not treated, up to 40 percent of these women will develop pyelonephritis, which increases the rate of premature deliveries and perinatal death. During infancy, males have a higher prevalence of congenital anomalies that predispose them to UTIs, and thus have a higher incidence of UTIs than females. In addition, after 50 years of age, the incidence of UTIs is similar between men and women, largely because older men often have enlarging prostates, potentially causing urinary obstruction and increased risk for infection. There does not seem to be an increase in UTIs in men with diabetes as there
1722 Urinary Tract Infections is in women. During the intervening years, infections of the urinary tract in males are rare, and often acquired via sexual contact. Pathogenesis There are a large number of bacteria that can potentially cause infection of different parts of the urinary tract. For young women with cystitis, the majority of infections are caused by Escherichia coli, followed by Staphylococcus saprophyticus, Klebsiella species, Proteus species, and enterococcus species. It is most often the case that bacteria enter the urinary tract via ascent through the urethra into the bladder, and then retrograde through the ureters to the kidney. The normal bacterial flora around the urethra consists of diphtheroids, streptococcal species, lactobacilli, and staphylococcal species that are not associated with UTIs. The bacteria that cause UTIs colonize the area around the urethra and the opening of the vagina and are thought to come from the bowel. The entry of bacteria into the bladder does not always cause infection, and the body has a number of ways to eliminate invading bacteria. Normal urination often flushes the organisms from the bladder and urethra. In addition, the mucosal surface of the bladder has antibacterial properties, and the urine creates an environment that is inhospitable to bacteria with a low pH, a high concentration of urea and organic acids, and a high concentration of solutes. However, there are predisposing factors that can override these defenses and lead to infection, including alterations in the normal vaginal flora by antibiotic treatment, genital infections, the use of contraceptives such as spermicides, and increased rate of entry secondary to urethral massage during vaginal intercourse. Symptoms UTIs can be classified as symptomatic or asymptomatic. Asymptomatic bacteruria is when bacteria can be detected in the urine but the person experiences no symptoms. When a patient experiences symptoms of cystitis, they often report pain or burning with urination, the sensation of needing to urinate frequently, an urge to urinate, and pain the lower abdomen. Often, the urine itself looks cloudy or contains blood
and can be malodorous. These symptoms are not life threatening but cause significant discomfort and, if untreated, can lead to infections of the upper urinary tract. If the patient has a fever, nausea and vomiting, diarrhea, as well as tenderness in the flanks (overlying the kidneys), these are often symptoms of an upper UTI, such as pyelonephritis. Treatment The location of the UTI has a large influence on the type, length and success of treatment. If the infection is restricted to the bladder, often a single antimicrobial agent to which the bacteria is susceptible can be used to rapidly treat the infection. It is recommended that after treatment, a test of cure is performed to ensure that bacteria are no longer found in the urine. This is becoming especially important as an increasing number of bacteria are becoming resistant to common antibiotics. If it is a case of complicated cystitis, secondary to catheterization, an anatomic abnormality, or obstruction, the infecting bacteria is often resistant to antibiotics and drug therapy must have wide coverage. Pregnant women should be routinely screened during the first trimester for asymptomatic UTIs and treated. When the infection includes the upper urinary tract, treatment courses of several weeks may be necessary, and may be initiated using intravenous antibiotics during a hospital stay. Most cases of UTIs, including cystitis and pyelonephritis, resolve without further complications. SEE ALSO: Antibiotics; Bacterial Infections; E. Coli Infections; Pregnancy; Prenatal Care; Women’s Health Care (General). BIBLIOGRAPHY. Paul B. Iannin, Contemporary Diagnosis
and Management of Urinary Tract Infections (Handbooks in Health Care Company, 2003); Icon Health Publications, The Official Patient’s Sourcebook on Urinary Tract Infection: A Revised and Updated Directory for the Internet Age (Icon Health Publications, 2002); Harry Mobley and John W. Warren, M.D., eds., Urinary Tract Infections: Molecular Pathogenesis and Clinical Management (ASM Press, 1996). Christine Curry Independent Scholar
Urological Surgeon A urological surgeon is a surgeon who works in the field of urology which is concerned with the urinary tracts of both males and females, and also the reproductive system of males. This involves work on the kidneys, the bladder, and the urethra, and also the male reproductive organs. Traditionally, many urological problems went untreated with people anxious to avoid invasive surgery. However, many of the problems and disorders could, historically, only be treated by surgery. Much of it was concerned with the removal of bladder stones, which was done with surgery. However, many urological procedures were developed during the 19th century, and the nature of urological surgery changed when an early urological surgeon, the German doctor Gustav Simon, in 1869, was able to demonstrate that human patients could survive after the removal of one of their kidneys providing
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the other one was healthy. This has meant that many urological surgeons are involved in the removal of kidneys and also in kidney transplants. Kidney removal and kidney transplants are now major areas of medical science. Although kidney transplants have been carried out since the late 1950s, major progress was made only in 1963 when the immunosuppressive drug azathioprine was developed to prevent the recipient’s body rejecting the new kidney. Many famous people have had kidney transplants: the Australian media identity and billionaire Kerry Packer whose donor was his helicopter pilot and the Philippine president Ferdinand E. Marcos who survived one failed operation, had a second using a kidney from his sister, and eventually succumbed to kidney problems. SEE ALSO: Kidney Transplantation; Urologist. BIBLIOGRAPHY. Austin Ingram Dodson, Urological Surgery (Mosby, 1970); Andrew C. Novick, Inderbir S. Gill, and J.
Urilogical surgeons conduct surgery involving the kidneys, the bladder, the ureters, and the urethra, and also the male reproductive organs. They are involved in the removal of kidneys and also in kidney transplants.
1724 Urologist Stephen Jones, eds., Operative Urology: At the Cleveland Clinic (Springer-Verlag New York, LLC. 2006); John Reynard, et al., Oxford Handbook of Urology (Oxford University Press, 2005); J. Swinney and D. P. Hammersley, A Handbook of Operative Urological Surgery (Livingstone, 1963). Justin Corfield Geelong Grammar School, Australia
Urologist A urologist is a medical doctor who works in the field of diagnosis and treatment of diseases and disorders that affect the urinary tract of both males and females, which include the kidneys, the bladder, the ureters, and the urethra, and also the male reproductive organs. As such, their work combines the management of nonsurgical problems which include urinary infections, and also surgical issues which range from the correction of congenital abnormalities to the surgical management of cancer. Many urologists are also involved in the assessment and treatment of incontinence and related disorders. Some urologists specialize in particular fields with urologic oncology, stone disease, pediatric urology, sexual dysfunction, and male infertility being some of those areas. One of the earliest urologists was the Spanish surgeon Francisco Diaz, who in 1588, wrote the first book on the diseases of the bladder, kidneys, and the urethra, and is now generally acknowledged as the founder of modern urology. The German urologist Max Nitze developed the cytoscope in 1877—this tube serving as a viewing instrument and preventing the need for invasive surgery to examine and drain the bladder. Today, X-ray techniques provide extremely important ways of diagnosing problems, but the cytoscope is still used for certain procedures. Another well-known urologist is Charles B. Huggins. He was responsible for researching the relationship between hormones and certain types of cancer, sharing the Nobel Prize for Physiology or Medicine in 1966 with the pathologist Peyton Rous. Another well-known pioneer urologist was William F. Braasch, whose account of his work at the Mayo Clinic in the United States, Early Days in the
Mayo Clinic (1969), describes his work. The American Urological Association Inc. was founded in 1902 and has about 12,000 members. The Association publishes The Journal of Urology each month, and the AUA News six times a year. SEE ALSO: Bladder Diseases; Urological Surgeon. BIBLIOGRAPHY. William F. Braasch, Early Days in the Mayo Clinic (Charles C. Thomas, 1969); John Reynard, et al., Oxford Handbook of Urology (Oxford University Press, 2005); Richard Uebelhoer, Renal Diseases as Seen by the Urologist (CIBA, 1961).
Justin Corfield Geelong Grammar School, Australia
Uruguay Uruguay is located on the southeastern coast of South America, between Brazil and Argentina. It is the second-smallest nation in South America, comparable in size to Washington State and home to just 3 million people. Over 90 percent of the population is of European descent, primarily Spanish and Italian; it is the only state in South America that has no Amerindian . Uruguay has a large, educated, urban middle-class and an diversified economy driven by agricultural exports, tourism, and a broad mix of service and factory-based industries. The population is 3,461,000 and growing at 0.504 percent annually. The birth rate is 14.41 per 1,000 and the death rate is 9.16 per 1,000. Median age is 32.9 years. Life expectancy is 72.68 years for males and 79.3 years for females. Gross national income in $4,360 per person, with 27 percent defined as living in poverty. Uruguay’s export-oriented economy took a severe downturn in 2001–2 as the economies of neighboring Argentina and Brazil faltered, but has begun a modest rebound. Ninety-three percent of Uruguyans live in urban areas. Uruguay is free from malaria, dengue fever, yellow fever, plage and schistosomiasis. The spread of Chagas’ disease seems to have ended in 1997. Leprosy, once a major health problem, is down a to a few, sporadic cases a year. All Uruguayans have access to
clean water and sanitary waste disposal. There is a low level of viral hepatitis. Immunization rates among children are 98 percent. Polio, diphtheria and neo-natal tetanus have been eradicated. Hantavirus arrived in the country in 1997, and there have been limited outbreaks of meningitis in recent years. The prevalence rate for tuberculosis is 36 per 100,000 people. HIV/AIDS is present in 0.5 percent of the population, or about 9,600 people. Although this rate is low, the virus is spreading rapidly through the young, with women most at risk. UNAIDS believes Uruguay needs to be more aggressive in implementing education and treatment programs. Cardiovascular disease is the leading killer of Uruguayans, responsible for 30 percent of all deaths, and 80 percent of deaths in those over the age of 60. The main risk factor seems to be diet. The standard Uruguayan diet is high in fat: a survey in the 1990s found that fat comprised 32 percent of people’s total caloric intake. In another study of 4,000 adults in the capital city of Montevideo 47 percent of males and 58 percent of females were found to have a high body mass index. Diabetes is another growing problem, with 154,000 diabetics in 2000 expected to increases to 224,00 by 2030. Additionally, cancers are responsible for 22 percent of all deaths. Child mortality is low in Uruguay, with 14 deaths per 1,000 in infants under 1, and 15 deaths per 1,000 in children between the ages of 1-5 years. Accidents and acute respiratory illnesses are the leading causes of death in the young. Rates of malnutrition and stunting are low, but childhood obesity may be on the rise. Maternal mortality is also low, with 27 deaths per 100,000 live births. Ninety-four percent of women receive prenatal care and almost all births take place in a hospital. The total fertility rate is 1.97 children born per woman, with 84 percent of women using contraception. Abortion is prohibited in Uruguay, and complications from illegal procedures are the leading cause of maternal deaths within the country. Attempts to liberalized abortion laws failed in 2005. The government spends around $136 per capita on health each year. There are both public and private care systems. With 3.65 physicians and 0.85 nurses per 1,000 population, health facilities have adequate staff to meet the needs of the population. There are 24 hospital beds per 10,000 people.
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SEE ALSO: AIDS; Arteriosclerosis; Diabetes. Bibliography. Central Intelligence Agency, “Uruguay,” CIA World Factbook. www.cia.gov/library/publications/ the-world-factbook/geos/uy.html (cited July 2007); Globalis: An Interactive World Map, “Uruguay—Tuberculosis cases per 100,000 people,” .globalis.gvu.unu.edu/indicator_detail. cfm?IndicatorID=78&Country=UY (cited July 2007); The Joint United Nations Programme on HIV/AIDS, “Uruguay,” www.unaids.org/en/Regions_Countries/Countries/uruguay.asp (cited July 2007); New Internationalist, “Women’s Rights: A drama unfolds,” www.newint.org/issue373/drama. htm (cited July 2007); Pan American Health Organization, “Health in the Americas: Uruguay (1998),” www.paho.org/ english/HIA1998/Uruguay.pdf (cited July 2007) United Nations Children’s Fund, “Uruguay—Statistics,” http://www. unicef.org/infobycountry/uruguay_statistics.html#28 (accessed July 2, 2007); World Health Organization, “A guide to statistical information,” www.who.int/whosis/en/index. html (cited July 2007).
Heather K. Michon Independent Scholar
Usher Syndrome Usher Syndrome is the most common condition that involves both hearing and visual disturbances. Between 3-6 percent of deaf children or children with hearing impairment have Usher’s, roughly four in 100,000 live births in the United States. Signs and symptoms include moderate to severe hearing impairment, retinitis pigmentosa, and normal to severe balance problems. Usher Syndrome was first described in Germany in the middle of the 19th century by Albrecht Von Graefe but is named for Charles Usher, a British ophthalmologist who showed the inheritance pattern of this syndrome in 1914. There are three types of Usher Syndrome; all passed by autosomal recessive inheritance. This indicates that both parents have a copy of the mutated gene and it was passed via a non-sex chromosome. USH1 is the most severe; children are born deaf or nearly deaf, have severe balance problems, and develop vision problems by the age of ten. USH2 is characterized by moderate to severe hearing impairment,
1726 Uterine Cancer normal balance, and vision problems beginning in the teenage years. USH3 is highly variable. Typically children are born with normal hearing, most have normal balance, and characteristics of Usher’s develop after puberty with blindness and deafness occurring in mid-adulthood. The visual problems of Usher Syndrome are due to retinitis pigmentosa, a degeneration of the photoreceptor cells in the retina. There are two types of photoreceptor cells: rod cells and cone cells. Rod cells are for night vision and see objects in the periphery. Cone cells help distinguish fine detail and also perceive color. The most common type of retinitis pigmentosa seen with Usher Syndrome is rod cell dystrophy. Patients will first note night blindness, followed by loss of peripheral vision with a progression toward tunnel vision; full blindness may or may not occur. The diagnosis of Usher Syndrome is made by the combination of hearing impairment and retinitis pigmentosa. A full history and complete eye and hearing exam are important in making the diagnosis. Additional tests can be run for early detection, including electronystagmography (ENG) to assess balance and electroretinography (ERG) to detect retinitis pigmentosa. Treatment options are limited, as there is no cure for Usher Syndrome. Vitamin A may slow the progression of retinitis pigmentosa. Hearing aids and cochlear implants are sometimes helpful, but not curative. The most important treatment is counseling, orientation and mobility training, as well as educational programs for anticipated lifestyle changes. Research is underway to determine the exact gene(s) associated with Usher Syndrome. Twelve loci have been identified and seven of these contain proteins that have already been linked to Usher Syndrome. This knowledge will help with genetic counseling, early detection, and treatment for patients living with Usher Syndrome. SEE ALSO: Child Development; Chromosome; Deafness;
Developmental Disabilities; Genetic Disorders; Genetic Testing/Counseling; Infant and Toddler Development; Rare Diseases.
BIBLIOGRAPHY. National Institute on Hearing and Oth-
er Communication Disorders, “Usher Syndrome,” www. nidcd.nih.gov/health/hearing/usher.htm (cited August
2006); Emanuel Rubin, Rubin’s Pathology Clinicopathologic Foundations of Medicine, 4th ed. (Lippincott Williams & Wilkins, 2005). Gautam J. Desai, D.O. Erin Smith, MS II Kansas City University of Medicine and Biosciences College of Osteopathic Medicine
Uterine Cancer Uterine cancer is often called endometrial cancer because that is the most common cell type tumor found in uterine cancers. The uterus is the reproductive organ in a woman’s body where a fetus develops. Uterine cancer is ergo a type of reproductive cancer. Men do not have a uterus and therefore cannot develop uterine cancer. The greatest risks for developing uterine cancer include being post-menopausal, using estrogen replacement therapy, and obesity. Probably in relation to being post-menopausal, women over fifty years of age are at an increased risk of developing uterine cancer, compared to younger women. Additionally, higher than normal levels of circulating estrogens in the body may predispose a woman to uterine cancer. Elevated estrogens are seen in very overweight people, as well as people with high blood pressure and diabetes. Despite this relation between uterine cancer and high levels of estrogens, hormone replacement therapy of estrogen in conjunction with progestin does not seem to lead to uterine cancer as hormone therapy with estrogen alone will. The progestin is believed to protect the endometrial lining of the uterus from the effects of estrogen. In a similar fashion, women who take contraceptives that contain both estrogen and progesterone are at a decreased risk of developing uterine cancer. There are additional factors which may affect a woman’s probability of developing uterine cancer. These factors include early onset of menses (prior to the age of 12 years old), late onset of menopause (after the age of 50 years old), never having been pregnant, and the use of Tamoxifen for blocking estrogens as a treatment for advanced breast cancer. Uterine cancer has symptoms such as abnormal vaginal bleeding (such as after a woman has gone through menopause), unusual vaginal discharge, pain in the pel-
vic area, pain during intercourse, and difficulty in urination. Pelvic pain usually occurs in the later stages of cancer. As with many cancers, the probability of successful treatment for uterine cancer increases dramatically as the diagnosis is earlier. While vaginal bleeding and discharge may be signs of a benign condition, approximately 90 percent of uterine cancer patients experience these symptoms, according to the American Cancer Society. It is therefore important for a woman to see a physician immediately if such symptoms appear. There are several types of exams to diagnose uterine cancer. The quickest, least involved procedure is an endometrial biopsy. During this type of biopsy, the doctor inserts a slim tube into the patient’s vagina and uses this tube to excise a small piece of tissue from the uterine wall. The location of the sample is usually selected by the physician after examining the uterus via ultrasound for suspicious areas. The biopsied tissue sample is then examined under a microscope, for the presence or evidence of cancerous cells. The entire tissue sampling process usually takes under a minute, and should cause only minimal discomfort to the patient. As a prophylactic measure, the woman may take a nonsteroidal anti-imflammatory drug (such as Ibuprofen) prior to the procedure. A more invasive procedure is called Dilatation and Curettage, or D & C for short. The patient is usually under general anesthesia for this procedure, during which the physician dilates her cervix (the opening to the uterus), and collects uterine tissue via scraping or suctioning of the uterine wall. Some patients prefer conscious sedation, whereby intravenous medication makes them drowsy but not asleep as anesthesia would. The patient need not stay at the physician’s office for long; generally, she can leave after one hour, and most patients feel minimal or no discomfort following the procedure. In the case of a patient who for other medical reasons such as being extremely overweight or having high blood pressure cannot undergo general anesthesia, certain medical imaging techniques can be employed to visualize the uterus and look for tumors. Options include Magnetic Resonance Imaging (MRI), a Computed Tomography (CT) scan, and an ultrasound. Once diagnosed, uterine cancer is classified on a Staging scale. The Stage tells physicians how advanced the cancer is, and how far it has spread; i.e., if it has invaded other tissues or has remained in the uterus.
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This knowledge affects the treatment regimen, as well as helps to determine the prognosis. Staging is based on accepted standards by the International Federation of Gynecology and Obstetrics (FIGO). It is a surgical grading system, based on the tissue samples removed during a procedure. There are four stages of uterine cancer, I-IV; the lower the grade, the less advanced the cancer. In Stage I, the cancer is still localized to the uterus. It can be limited to the endometrium (Stage IA), have progressed less than halfway through the muscular myometrial wall (Stage IB), or more than halfway through the myometrium while remaining in the uterus (Stage IC). In Stage II, the cancer has spread from the uterus to its opening into the vagina below, called the cervix. It can be limited to the inner lining cervical glands (endocervical glands – Stage IIA), or it can have invaded the connective tissue of the cervix, called the stroma (Stage IIB). Once the cancer has spread beyond the uterus and cervix, but is still within the pelvic area, it is classified as Stage III. Stage IIIA uterine cancer has affected one or more of the following: the outer uterine layer, the surrounding fallopian tubes or ovaries, or the cells in the peritoneal fluid, which washes the inner lining of the abdomen and pelvis. Stage IIIB uterine cancer has invaded the vagina. Stage IIIC uterine cancer may have affected some or none of the peri-uterine areas, but has invaded the lymph nodes immediately draining the uterus. Once the cancer has spread beyond these regions, it is classified as Stage IV, the furthest progressed. Stage IVA uterine cancer has invaded the inner rectal lining and/ or that of the bladder; however, lymph nodes may or may not be involved. If the cancer has spread to any other more distant organs such as the lungs or liver, regardless of its size in the uterus or if it has affected any lymph nodes, it is Stage IVB. To treat uterine cancer, the most common surgical intervention is removal of the uterus, a procedure called a hysterectomy. Sometimes it is necessary to remove the fallopian tubes and ovaries, as well, to best protect the patient. Following surgery, radiation and / or chemotherapy may be administered. Additionally, the woman may take progesterone supplements, to balance out the high levels of estrogen in her body. According to the American Cancer Society, the fiveyear survival rate for women who undergo surgery while still in Stage IA is 91 percent.
1728 Uterine Diseases SEE ALSO: American Fertility Association (AFA); Ameri-
can Society of Clinical Oncology; Breast Cancer; Cancer (General); Cancer Alternative Therapy; Cancer Chemotherapy; Cancer Radiation Therapy; Cancer—Coping with Cancer; Chemoradiotherapy; Chemotherapy; National Cancer Institute (NCI); National Coalition for Cancer Survivorship (NCCS); National Program of Cancer Registries (NPCR); Oncologist; Oncology; Ovarian Cancer. BIBLIOGRAPHY. American Cancer Society, “How is En-
dometrial Cancer Staged?”, www.cancer.org (cited August 2007); Fran Drescher, Cancer Schmancer (Warner Books, 2003); Arlan F. Fuller Jr., Robert H. Young, and Michael V. Seiden, Uterine Cancer (American Cancer Society Atlas of Clinical Oncology) (BC Decker, 2004); David M. Luesley, Frank Lawton, and Andrew Berchuck, Uterine Cancer (Informa Healthcare, 2005); Mayo Clinic, Mayo Clinic: Guide to Women’s Cancers (Kensington Publishing Corporation, 2005). Claudia Winograd University of Illinois at Urbana-Champaign
Uterine Diseases The uterus is a hollow, pear-shaped organ of the female reproductive tract. It is located in the pelvis, with the bladder anteriorly and the rectum posteriorly. The lower end of the uterus is a narrow canal, called the cervix, that opens into the vagina. The upper end of the uterus opens on either side to the two fallopian tubes that form canals between the uterus and the ovaries. The uterus, cervix, vagina, ovaries, and fallopian tubes comprise the female reproductive system. In the years between menarche (the onset of menstruation and ovulation) and menopause (cessation of menstruation and ovulation), the inner layer of the uterus (endometrium) is prepared monthly for the possible implantation of an embryo. There is a thickening of endometrium triggered by hormonal changes. If no implantation occurs, the inner layer sloughs off, leading to menstruation. The outer later of the uterus (myometrium) is the muscular layer that can stretch significantly during pregnancy. There are multiple disease processes, both malignant and benign,
that can affect the uterus, causing significant morbidity and mortality worldwide. Benign Diseases of the Uterus Endometrial polyps are overgrowths of glands in the uterine endometrium. They are soft, pliable, and protrude from the inner surface of the uterus, often by stalks or pedicles, although they can be sessile, or closely apposed to the endometrial surface. Diameter varies from a few millimeters to several centimeters. The majority of women with endometrial polyps have no symptoms. However, endometrial polyps can cause abnormal bleeding, such as heavier-than-normal menstruation (menorrhagia) or bleeding between menstruation. It is estimated that 25 percent of reproductive-aged women have endometrial polyps. There is a low risk (0.5 percent) of malignant transformation of a polyp. If a polyp is causing symptoms, it can be removed using curettage or long forceps. Leiomyomas, commonly referred to as fibroids, are the most common benign tumor in the pelvis, and are composed of muscle cells and some fibrous tissue. Up to 25 percent of Caucasian women will have leiomyomas, and up to 50 percent of African women have leiomyomas. They may be small but can grow to large sizes, displacing organs in the pelvis and abdomen. Leiomyomas are categorized by the location within the layers of the uterus, including intramural, subserous, and submucous. Often, leiomyomas are asymptomatic, but if submucosal, they can lead to abnormal vaginal bleeding, infertility, or abortion. Common symptoms of leiomyomas include pelvic pain. Their growth is linked to the mount of circulating estrogen, leading to increases in size, for example, during pregnancy. This hormone responsiveness also means that leiomyomas are not detected before the onset of puberty. If a female is experiencing symptoms, it is possible to treat leiomyomas medically, with compounds that reduce circulating levels of estrogen and progesterone. Additionally, a myomectomy (removal of the leiomyoma) or a hysterectomy (removal of the uterus) can be performed. Adenomyosis is the growth of endometrial glands and stroma into the muscular layer of the uterus, the myometrium. These areas do not undergo the normal cyclical changes associated with menstruation. Usually, adenomyosis does not produce symptoms, and is more common in women between the ages of 35 and 50.
Uterine Diseases
When adenomyosis does produce symptoms, they include painful menstruation (dysmenorrhea) and heavy menstruation (menorrhagia). Diagnosis includes biopsy of the endometrium, but finding adenomyosis does not rule out the presence of more serious causes of vaginal bleeding. There are no medical treatments available for adenomyosis. Treatment involves a hysterectomy. Endometriosis is the presence and growth of uterine tissue in locations outside of the uterus. The most common site is the ovary. These aberrantly located glands and stroma of endometrial origin are sensitive to hormonal changes and will grow under the influence of these hormones. The most common symptom of endometriosis is cyclic pelvic pain. Treatment can be medical use of sex hormones or surgical removal of ectopic endometrial tissue without the removal of the uterus, fallopian tubes, and ovaries. Malignant Diseases of the Uterus Endometrial carcinoma is the most common pelvic cancer in women. There are two types of endometrial carcinomas: those associated with unopposed estrogen exposure and endometrial hyperplasia and those that grow independently of estrogen and are found in a setting of endometrial atrophy. Women exposed to high levels of estrogens, through estrogen therapy with no progesterone, polycystic ovary syndrome, or chronic anovulation have an increased rate of endometrial carcinoma. Three-quarters of females diagnosed with endometrial carcinoma are over the age of 75, with Caucasian women having a higher incidence as compared to African women. Symptoms of abnormal vaginal bleeding, such as intermenstrual spotting or postmenopausal bleeding, occur in 80 percent of women with endometrial carcinoma. Additionally, patients may experience pelvic pain and cramping. Treatment is often operative, with a hysterectomy, and may include radiation therapy, hormone therapy, or chemotherapy. Survival after treatment for endometrial carcinoma is largely based on the stage of the disease when discovered. If found early, five-year survival rates are as high as 80 to 95 percent, while stage four carries a five-year survival of only 5 to 20 percent. Sarcomas of the uterus are relatively rare but are highly malignant. Different forms of sarcomas can arise from the myometrial smooth muscle or endometrial stromal cells. A common feature of these tumors is early metastasis to the abdomen, liver, and
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lungs. These tumors are most common after age 40. Again, the most common symptom of a uterine sarcoma is abnormal uterine bleeding, often with pelvic pain, constipation, and a mass in the abdomen. Pts may also have complications from blood loss, such as anemia. Treatment relies heavily on surgical resection via hysterectomy, as well as removal of lymph nodes. Chemotherapy and radiation therapy may be used in addition to surgery. The grade of the tumor at the time of diagnosis is an important predictor of survival. In patients with high-grade sarcomas, the presence of metastasis bodes for a less-than-10-percent survival rate at two years. Low-grade sarcomas, however, have an 80 to 100 percent five-year survival rate. Common features of both benign and malignant diseases of the uterus are abnormal vaginal bleeding and pelvic pain, making it important to determine the cause of these symptoms rather than presume that the cause is a benign process. In addition, education of women and awareness of changes in menstrual patterns are important considerations when evaluating the global burden of uterine cancer. Similarly, access to a gynecologist is often a limiting factor in diagnosing and treating both benign and malignant disorders. Diagnosis of many of these diseases can be accomplished via endometrial biopsy, where a small piece of endometrial tissue is removed and examined under a microscope. In addition, in a resource-rich setting, an option to aid in diagnosis is a hysteroscopy, using a video camera to see the inside of the uterus. SEE ALSO: Obstetrician/Gynecologist; Uterine Cancer;
Women’s Health (General).
BIBLIOGRAPHY. Icon Health Publications, The Official Pa-
tient’s Sourcebook on Uterine Sarcoma: A Revised and Updated Directory for the Internet Age (Icon Health Publications, 2002); Gale Reference Team, “Uterine Cancer; Facts to Know,” NWHRC Health Center—Uterine Cancer (June 8, 2006); Susan E. Hankinson, et al., eds., Healthy Women, Healthy Lives: A Guide to Preventing Disease, from the Landmark Nurses’ Health Study (Free Press, 2002); PM Medical Health News, 21st Century Complete Medical Guide to Uterine Diseases and Uterine Fibroids (Progressive Management, 2004). Christine Curry Independent Scholar
1730 Uzbekistan
Uzbekistan Uzbekistan is located in Central Asia in the center of a neighborhood of “stans,” bordered by Kazakhstan, Kyrgyzstan, Tajikistan, Turkmenistan and Afghanistan. Occupied since the 2nd Century b.c.e., Uzbekistan was folded into the Soviet Union at the start of the 20th Century CE. Independence came with the fall of the Soviet state in 1991. Uzbekistan is the most populous country in Central Asia and is rich in natural resources, including oil, natural gas, gold, coal, copper, silver and uranium. It is the world’s fourth largest producer of cotton and seventh largest exporter of gold. Uzbekistan shows great promise for future development, but for now, most of its citizens remain locked in poverty. The population is 27,780,000 and growing at 1.732 percent. The birth rate is 26.46 per 1,000 and the death rate is 7.73 per 1,000. Median age is 22.9 years. Life expectancy is 61.57 years for males and 68.56 years for females. Gross national income is $510 per person, with a third of the population living in poverty and 17 percent living on less than $1 a day. The official unemployment rate is 3 percent, but 20 percent are underemployed; the official inflation rate is 7.6 percent, but a 2006 survey found a 38 percent increase in the cost of consumer goods. Mortality from communicable diseases is lower in Uzbekistan than other Central Asian States, with 35 deaths per 100,000 stemming from communicable causes, compared with more than 60 per 1,000 in nearby Tajikistan. Eighty-two percent of the population has access to safe water and 67 percent use sanitary waste facilities. About 70 percent of all infections are intestinal disorders, including dysentery, salmonella poisoning, and viral hepatitis. Uzbekistan used to have the highest viral hepatitis rates in Central Asia, with a prevalence rate of 1,400 per 100,000 in 1992-94, although this figure dropped to about 700 by 1998. The country also used to have Central Asia’s highest malaria rates, with 80 percent of the population affected annually, but after eradication program in the 1960s, infections became far more sporadic. The prevalence of HIV/AIDS is low, affecting 0.2 percent of the adult population, or about 31,000 people. The government has taken steps to institute education and prevention programs, but strong taboos against discussing sex has made open dialog difficult. Discrimination against those with HIV is common.
Cardiovascular disease is the leading cause of mortality in Uzbekistan. Mortality due to cirrhosis and other chronic liver disease is the highest in Europe, although it seem to stem more from the high viral hepatitis rate rather than alcohol abuse. Excessive use of alcohol is rare in Uzbekistan, with 88 percent of the population belonging to the Muslim faith. The country has lower rates of alcohol-related traffic accidents, and fewer alcoholic poisoning. Rates of homicide and suicide are also lower than the other Central Asian Republics. The main risk factors for disease are obesity and tobacco use. A survey in the 1990s found that 50-55 percent of males used tobacco, with chewing tobacco being the most common. About 18 percent of the population is overweight, and in 2000 the World Health Organization estimated 430,000 diabetics within the country. That figure is expected to rise to almost 1.2 million by 2030. Cancer rates within Uzbekistan are the lowest in Europe. Total fertility rates for women have been dropping steadily since the 1990s, now at 2.88 children per woman. Almost 70 percent of women use contraception, and abortion is legal through the first 12 weeks of pregnancy. Ninety-seven percent of women receive prenatal care, and 96 percent have trained attendants during delivery. Maternal mortality is 24 deaths per 100,000. Infant mortality is 57 per 1,000, and child mortality is 68 per 1,000. Immunization is almost universal. Uzbekistan spends about $8 per capita on health. While healthcare is free and universal under the Constitution, in reality, most Uzbekis end up paying for care out of their own pockets. SEE ALSO: Healthcare, Asia and Oceania; Hepatitis; Ma-
laria.
Bibliography. Embassy of Uzbekistan to The United
States, “About Uzbekistan/Health,” www.uzbekistan.org/ uzbekistan/health/ (cited August 2007); World Health Organization, “Highlights on Health in Uzbekistan,” www. euro.who.int/document/e71959.pdf (cited August 2007); World Health Organization, “Malaria in the WHO European Region—Uzbekistan,” www.euro.who.int/malaria/ ctryinfo/affected/20020712_7 (cited August 2007). Heather K. Michon Independent Scholar
V Vaginal Cancer Carcinoma of the vagina that is not an extension of cervical or vulvar neoplasia is extremely rare. Studies estimate that vaginal cancer is responsible for only 1 to 3 percent of all gynecologic cancers. Most cancers discovered in the vagina are a result from local spread from the cervix or vulva, or are metastases from the endometrium, ovary, bladder, or colon/rectum. The most common location for vaginal carcinoma is the upper third of the vagina. Like cervical or vulvar cancers, vaginal cancers are categorized as preinvasive (or intraepithelial) or invasive. Preinvasive lesions are usually detected by an abnormal Pap smear of the vagina in a woman who has had a hysterectomy. It is possible that an abnormal Pap smear of a woman with a cervix is determined to have a preinvasive cancer of the vagina and not the cervix, but this is very rare. The majority of women with these lesions have a history of either vulvar or cervical neoplasias. In either case, intraepithelial lesions are small areas of atypical cell growth and not likely to provide any signs or symptoms. Invasive lesions can be larger and go deeper into the vaginal tissue. These types of lesions can cause vaginal bleeding, but only in later stages. Earlier signs may be a bloody vaginal discharge or increased frequency or ur-
gency of urination if the lesion is on the anterior vaginal wall near the neck of the bladder. Although these cancers can occur in adult women across the lifetime, most cases are seen in women between 60 and 80 years of age. The cause of vaginal cancer remains a mystery, but many of the known risk factors for cervical cancer correlate very highly with attributes of women with vaginal cancer causing some to suspect that the human papillomavirus (HPV) may play a role in this disease as well. Women with vaginal cancer are more likely to have had an early sexual debut, have more than five lifetime sexual partners, and smoke cigarettes than a group of similar women without vaginal cancer. In addition, HPV DNA was identified in the tumors of 60to 80 percent of women with vaginal cancer. Antibodies to HPV type 16 is highly correlated with risk of vaginal cancer. Treatment options vary depending on the category (preinvasive or invasive) and extent of the disease. In small, preinvasive lesions, treatment might consist of a local excision or chemotherapeutic cream applied to the walls of the vagina at night over a period of several months. Alternatively, it might be possible to laser ablate the lesion or use cryosurgery in a manner similar to treatment of preinvasive cervical lesions, although this remains somewhat controversial. Invasive lesions of the vagina are usually treated with some combination of surgery and local radiation depending on the
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1732 Vaginal Diseases stage of the disease. In these cases, lymph node dissection may also be necessary. Because vaginal cancer is so rare, studying adequate numbers of treated patients is difficult; however, a few studies of five-year survival are available. For women with early-stage disease, five-year survival is better than 70 percent. Survival drops to less than 50 percent for women with advanced vaginal cancer at time of diagnosis. Although vaginal cancer is very rare, there has been an increased awareness of it by the general population because of the DES-daughters phenomenon. Diethylstilbestrol (DES) is a nonsteroidal synthetic estrogen that was given to women during their first trimester of pregnancy in the late 1940s to 1960s. In the 1970s, it was discovered that some of the daughters of women who received this medicine during their pregnancy were developing a rare form of a rare cancer, namely clear cell adenocarcinoma of the vagina. The risk of developing clear cell carcinoma was 0.14 to 1.14 per 1,000 in daughters of DES-exposed women. DES is no longer given to pregnant women and cases of clear cell adenocarcinoma (even those not related to DES exposure) are exceedingly rare today. As with several other malignancies of the female reproductive tract, regular gynecologic exams and utilization of screening tools such as the Pap smear are vital to early detection and long-term survival. Although survival rates for vaginal cancer are not as high as those for cervical or vulvar cancer, very good treatment options are available and, in many case, vaginal malignancies are highly curable. Women who smoke and/or have already tested positive for HPV from a previous Pap smear should be extra vigilant about their gynecologic care. SEE ALSO: Cervical Cancer; Gynecology; Obstetrician/
Gynecologist; Vulvar Cancer.
Bilbiography. W. T. Creasman, “Vaginal Cancers,” Current
Opinion in Obstetrics & Gynecology (v.17, 2005); R. DeBernardo, et al., “Vulvar and Vaginal Cancers,” in B. J. Bankowski, et al., eds., The Johns Hopkins Manual of Gynecology and Obstetrics, 2nd ed. (Lippincott Williams, & Wilkins, 2002); N. F. Hacker, “Vaginal Cancer,” Practical Gynecologic Oncology, 4th ed. (Lippincott, Williams, & Wilkins, 2005). Megan K. Guffey, M.D., M.P.H. Independent Scholar
Vaginal Diseases Vaginal infections are one of the most common reasons for women to visit their family physician every year in the United States. Vaginal infections normally manifest as an itching, discharge, and malodor of the vaginal area. There are many kinds of vaginal diseases and all involve an infection or inflammation of the vagina. These include bacterial vaginosis, genital warts, herpes infections, gonorrhea, pelvic inflammatory disease (PID), syphilis, trichomoniasis, and vaginal yeast infections. Vaginal infections can be caused by viruses, bacteria, yeast, or parasites. Most vaginal diseases are acquired by sexual contact as sexually transmitted diseases (STDs), but some are transmitted by other methods. The three main types of vaginal diseases that will be considered here are bacterial vaginosis, trichomoniasis, and vaginal yeast infections. Genital warts, herpes infections, gonorrhea, PID, and syphilis are considered sexually transmitted diseases. These infections can affect men as well as women. Normal Vaginal Flora All outer surfaces of the human body contain a population of bacteria known as the normal flora. These bacteria are also called commensals. Normal flora colonize the human skin, gastrointestinal tract, and other mucous membranes that may readily come in contact in the environment. This includes the vaginal area. In general, normal flora act to benefit the host by colonizing the host surfaces to exclude potential pathogens and by stimulating the host immune system. A healthy vagina will typically contain normal flora consisting of Lactobacillus sp., Staphylococcus epidermidis, other Gram-positive cocci, Neisseria sp., various members of the Enterobacteriaceae family, and some Mycoplasma species. Lactobacillus sp. (especially Lactobacillus acidophilus in particular) are most commonly associated with normal vaginal flora and these bacteria play a key role in producing acids and reducing the vaginal pH. These conditions help to inhibit the growth of potential pathogens, thereby making the vagina a less hospitable environment for those potential pathogens. A decline in normal vaginal flora or an increase in vaginal pH, due to either the administration of antibiotics or any other reason, is thought to be a contributing factor for the onset of vaginal infections.
Bacterial Vaginosis Bacterial vaginosis is thought to be caused by bacterial species that are normally found in low numbers in a healthy vagina as part of the normal vaginal flora. Among women of childbearing age, bacterial vaginosis is the most common cause of vaginitis and it is the most frequent reason that women in the United States visit their physician. The Centers for Disease Control and Prevention (CDC) estimates that as many as 16 percent of pregnant women have a bacterial vaginosis infection in the United States each year. The most common causes of bacterial vaginosis are overgrowth by the following bacterial species: Gardnerella vaginalis, Bacteroides sp., Mycoplasma hominis, Ureaplasma urealyticum, and anaerobic bacteria such as Mobiluncus sp. and Prevotella species. The specific causes of bacterial vaginosis are not clear; however, activities or behaviors that upset the normal balance of bacterial normal flora in the vagina put women at increased risk. These risk activities and behaviors may include having a new sex partner or multiple sex partners, douching, and/or the use of an intrauterine device (IUD) for contraception.
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Bacterial vaginosis manifests clinically as a homogeneous and thin abnormal vaginal discharge that is often white or gray with a milk-like consistency. This discharge often has a foul smell that may be described as a fish-like odor. The discharge can be associated with itching or burning in the vaginal area. Other symptoms may include burning on urination and lower abdominal pain. That being said, however, it is estimated that about half of women who are infected with bacterial vaginosis will not experience any symptoms. Bacterial vaginosis is diagnosed by analysis of a sample of the vaginal discharge. Bacterial vaginosis is confirmed if three of the following four signs are observed: (1) presence of “clue cells” (vaginal epithelial cells that are covered with numerous bacterial species, normally associated with the membrane of the vaginal epithelial cell) and an associated absence of Lactobacilli species; (2) thin and/or homogeneous abnormal discharge; (3) the pH of the discharge is greater than 4.5; (4) the presence of a fishy or amine odor. Because the exact causes of bacterial vaginosis are not completely understood, prevention mechanisms are not fully clear. However, this infection is associated
A healthy vagina typically contains a normal amount and type of bacteria; however a decline in these vaginal flora or an increase in vaginal pH, due to either the administration of antibiotics or any other reason, is thought to be a contributing factor for the onset of vaginal infections.
1734 Vaginal Diseases with having a new sex partner or having multiple sex partners and women who have never had intercourse are rarely infected. As such, abstinence is thought to reduce the risk of infection. Avoidance of douching may also decrease the risk of bacterial vaginosis. Bacterial vaginosis is not normally associated with major complications in most otherwise healthy women. However, this infection can lead to premature delivery and low-birth weight if associated with pregnancy, so it is recommended that pregnant women with previous bacterial vaginosis infections be tested and treated if necessary. There is also evidence that bacterial vaginosis is associated with an increased chance of contracting other sexually transmitted infections, such gonorrhea, Chlamydia, or human immunodeficiency virus (HIV) infections. Trichomoniasis Trichomonas vaginalis is the most common protozoal urogenital tract infection and is the causative agent of trichomoniasis. For women, the vagina is the most common site of infection, whereas the urethra is the most common for men. Symptoms are more commonly manifested in women and infected men are often asymptomatic. Women who have abnormal vaginal alkalinity are believed to be predisposed to infections by Trichomonas vaginalis. Trichomoniasis is transmitted by sexual contact and is classified as a sexually transmitted disease. Trichomoniasis is the most common curable STD among young, sexually active women. The CDC estimates that 7.4 million new cases of trichomoniasis occur in men and women each year in the United States. Trichomoniasis often does not manifest clinically with any obvious symptoms, especially among infected men. Classically symptomatic women may present with an abnormal vaginal discharge that is described as copious, frothy, green or yellow in color, creamy, and extremely malodorous. Some women experience pain upon urination, itching and irritation around the vagina, and discomfort during sexual intercourse. If these symptoms are present, they normally appear within 5 to 28 days after infection. In the rare instance when men do experience symptoms, dysuria is the most common manifestation and in severe cases, a thin and whitish exudate may be present. Trichomoniasis can be diagnosed by collecting vaginal (or penile) secretions and observing a saline
wet mount. The presence of Trichomonas vaginalis is confirmed by observing a motile trophozoite. The motility is characteristic due to the undulating membrane and flagella of this protozoa. Infection by Trichomonas vaginalis can be prevented using the same methods for prevention of any sexually transmitted infection. Abstinence from sexual contact or commitment to a mutually monogamous relationship with an uninfected partner are the best methods to prevent contraction of all sexually transmitted infections. Use of latex condoms may also prevent the spread of trichomoniasis. There is some contradictory evidence that Trichomonas vaginalis can also be transmitted by wet towels, washcloths, and bathing suits, so avoidance of these items may also prevent infection. Trichomonas vaginalis infections may be associated with serious complications. It is hypothesized that trichomoniasis may be associated with a three- to fivefold increased risk of HIV transmission. Furthermore, trichomoniasis infection may increase the risk that an HIV-infected individual will transmit HIV to his or her sexual partner(s). Trichomoniasis may also be associated with the delivery of low-birth-weight or premature infants in infected pregnant women. Vaginal Yeast Infections Vaginal yeast infections are also known as vulvovaginal candidiasis, vaginal candidiasis, or mycotic vulvovaginitis. These infections occur when there is overgrowth of Candida species of fungi, typically Candida albicans. Candida sp. colonize the human body in small quantities as part of the normal vaginal flora. When there is an imbalance in the normal vaginal flora (i.e., normal vaginal bacterial flora numbers are reduced due to antibiotic treatment, hormonal changes, or if the normal vaginal acidity changes), Candida sp. of yeast can multiply and candidiasis symptoms can appear. Vaginal yeast infections are very common among women and it is estimated that up to 75 percent of women will have an infection due to Candida sp. with symptoms at some time in their life. Although vaginal yeast infections are not considered to be sexually transmitted infections, 12 to 15 percent of men typically develop symptoms after sexual contact with an infected partner. Risk factors for contracting a vaginal yeast infection are the same risk factors that cause a decrease
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in the normal bacterial vaginal flora. These include becoming pregnant, using oral contraceptives, taking antibiotics, and having diabetes mellitus. There is limited evidence to suggest that wearing tight clothing and underwear may also contribute to vaginitis. Vaginal yeast infections normally manifest clinically as itching, burning, and irritation of the vagina. Vaginal discharge may or may not be present, but if it is present, it is normally a white and thick discharge that is described as being curd-like. White spots may be seen in the vagina and the vaginal pH may or may not increase slightly during an infection. Some women will experience pain during urination and intercourse. It is estimated that up to 5 percent of women will experience chronic and reoccurring vaginal yeast infections. A recurrent yeast infection is defined as an infection that occurs four or more times over the course of one year in the absence of antibiotic use. Most infected males do not experience any symptoms. However, some men will experience a temporary rash or a burning/itchy penis. These symptoms, if present, normally manifest directly following intercourse with an infected woman. Vaginal yeast infections are diagnosed by examination of vaginal secretions in a KOH preparation. A Gram stain of the exudate may show yeast and/or mycelial forms that typically stain Gram-positive. Vaginal exudate may also be cultured on Sabouraud agar if necessary.
preventable. Some vaginal infections are transmitted by sexual contact (such as trichomoniasis), whereas others may be transmitted by other means (such as vaginal yeast infections).
Summary The three main types of vaginal infections are bacterial vaginosis, trichomoniasis, and vulvovaginal candidiasis. Bacterial vaginosis and vulvovaginal candidiasis both typically manifest when there is a disruption of the normal vaginal flora. The causative agents (typically Gardnerella vaginalis and Candida albicans, respectively) normally colonize a healthy vagina in small numbers. If there is a disruption in the normal flora (i.e., if the individual is taking antibiotics), the numbers of these pathogens can increase, leading to vaginal disease. Trichomonas vaginalis, on the other hand, is transmitted by direct contact and results in the clinical manifestation of trichomoniasis. Vaginal diseases are an important women’s health issue in the United States. Infections and inflammations involving the vagina are the number one reason for women to visit the family doctor each year. Most vaginal infections are treatable and some are
Vanuatu is an archipelago in the South Pacific Ocean, about 1,100 miles east of Australia. The island chain was long known as the New Hebrides, and was claimed by both the United Kingdom and France in the 19th century. In 1906, they agreed to rule jointly through a pact called the British–French Condominium, which lasted until the rise of an independence movement in the 1970s, culminating in the establishment of the Republic of Vanuatu in 1980. Vanuatu is comprised of 83 islands formed by volcanic action over many centuries. There are still a number of active volcanoes in the chain, which touch off frequent earthquakes and occasional eruptions. The population of Vanuatu is around 209,000 and growing at 1.4 percent annually. The crude birth rate is 22.72 per 1,000 population. Life expectancy is 67 years for males and 70 years f or females. The infant mortality rate is 27 deaths per 1,000 live births. The fertility rate for Vanuatuan women is 4.8 children.
SEE ALSO: AIDS; Bacterial Infections; Centers for Disease
Control and Prevention (CDC); Chlamydia Infections; Gonorrhea; Herpes Simplex; Infectious Diseases (General); Infertility; Sexually Transmitted Diseases; Viral Infections. Bilbiography. G. F. Brooks, et al., Jawetz, Melnick, and
Adelberg’s Medical Microbiology, 23rd ed. (Lange Medical Books/McGraw-Hill, 2004); M. R. Joesoef and G. Schmid, “Bacterial Vaginosis,” Clinical Evidence (v.13, 2005); F. S. Southwick, Infectious Diseases in 30 Days (McGraw-Hill, 2003); D. Spence, “Candidiasis (vulvovaginal),” Clinical Evidence (v.14, 2005); B. Van Der Pol, “Trichomonas vaginalis Infection: The Most Prevalent Nonviral Sexually Transmitted Infection Receives the Least Public Health Attention,” Clinical Infectious Diseases (v.44, 2007). Tracey A. Hunt, Ph.D. Kansas City University of Medicine and Biosciences
Vanuatu
1736 Varco, Richard L. Communicable and vectorborne diseases remain a source of concern on Vanuatu. In 2002, 60 percent of the population had safe drinking water and 50 percent had adequate sanitary facilities. Malaria and tuberculosis rates remain high; there were 14,700 cases of malaria in 2004 alone. The country is benefiting from funding provided by the Global Fund to Fight HIV/AIDS, Tuberculosis, and Malaria (GFATM). The island’s first human immunodeficiency virus (HIV) case was identified in 2002. The Ministry of Health used the occasion to educate the population about the risks of AIDS, and requests for AIDS testing among the young began to increase. There is also a high prevalence of sexually transmitted diseases in Vanuatu. Noncommunicable “lifestyle” diseases have not yet taken as high a toll on Vanuatuans as on other Pacific Islanders, but recent years have seen a spike in hypertension and diabetes cases. In 2003, the 10 leading causes of morbidity were acute respiratory disease, malaria, scabies and other skin diseases, worms, diarrhea, tooth and gum disease, eye infections, arthritis, injuries, and conjunctivitis. The leading causes of mortality were asthma, stroke, heart failure, diabetes, malaria, pneumonia, cardiac arrest, tuberculosis, septicemia, and malignancies. The Ministry of Health oversees the country’s single general hospital, 4 district hospitals, and 25 primary health centers. The medical community is small, with 29 doctors, 319 nurses, 50 midwives, and 51 support staff. Government expenditures on health totals 3.9 percent of the Gross Domestic Product. Vanuatu is believed to be the first country to lose land to global warming. In 2005, the 100 residents of the Lateu settlement on Tegua Island were forced to relocate due to rising ocean waters and higher tides, perhaps the first “climate refugees.” SEE ALSO: AIDS; Healthcare, Asia and Oceania. Bilbiography. Fadia Saadah and James Knowles, The
World Bank Strategy for Health, Nutrition, and Population in the East Asia and Pacific Region (World Bank Publications, 2001); World Health Organization, The World Health Report 2006: Working Together for Health (World Health Organization, 2006). Heather K. Michon Independent Scholar
Varco, Richard L. (1912–2004) Born on August 14, 1912, in Fairview, Montana, Richard L. Varco helped invent the implantable drug pump used in chemotherapy and heparin delivery, and eventually used to infuse insulin, spinal drugs, and anticlotting medicine into the body. Varco founded the University of Minnesota transplant unit, performing its first organ transplant. Instrumental in open heart surgery and corresponding research, he influenced the work of such transplant pioneers as Christiaan A. Barnard and Norman E. Shumway. Varco earned three degrees at the University of Minnesota: an M.B. in Physiology (1936), an M.D. (1937), and a Ph.D. with a major in Surgery and a minor in Biological Problems (1944). By 1950, he served as a full professor at the university. He married his wife Louise around 1940, and the couple raised eight children—Richard Jr., Robert, John, James, Anne, Charles, Mary, and Catherine. Varco lived to see the birth of 17 grandchildren and the death of one. On September 2, 1952, Varco served as the assistant in the world’s first successful direct-vision open heart surgery, performed at the University of Minnesota. Led by Dr. C. Walton Lillehei and Dr. F. John Lewis, the surgical team lowered the body temperature of the 5-year-old girl to protect her brain, anesthetized her, and used their 10-minute window of opportunity to stitch a hole located between the two upper chambers of her heart. In 1954, Varco served as the assistant in the first open heart operation using cross-circulation. The following year, he led the first bypass operation. The initial organ transplant operation that he performed at the university was a living donor kidney transplant between identical twins; each lived a healthy life for several decades thereafter. He received the Lasker Award (often dubbed the American Nobel Prize) in 1955, along with three colleagues, for his work on open heart surgery techniques. He served on the American Board of Surgery oral examinations. Varco died on May 3, 2004, and is buried in Austin, Minnesota. He had been married for 64 years, and his obituary listed the following personal interests: reading, hunting, gardening, cooking, playing bridge, and storytelling.
Vasculitis
SEE ALSO: Heart Transplantation; Organ Transplantation;
Surgery.
Bilbiography. The CardioThoracic Surgery Network, “In
Memoriam: Richard L. Varco,” www.ctsnet.org/doc/9219 (cited April 2007); G. W. Miller, King of Hearts, (Crown Publishers, 2002); J. S. Najarian, “Moments in Surgery: Richard L. Varco, The Compleat Academic Surgeon,” Surgery (v.133, 2003). Kelly Boyer Sagert Independent Scholar
Vasculitis The term vasculitis literally means inflammation of the walls of blood vessels. Vasculitides include a spectrum of diseases with variable causative factors and features which are classified on the basis of site and type of blood vessels involved. However, there is no standard classification of vasculitis because the causes and process of disease development are only superficially understood and the clinical presentations tend to overlap. It may occur in association with other systemic diseases or it may occur as a primary disease process, in which case, it is termed primary systemic vasculitides. Secondary vasculitis may occur as a complication of other systemic autoimmune diseases such as systemic lupus erythematosus and rheumatoid arthritis. The common complaints of patients who report early in the clinics include fever, muscle and joint pains, malaise, and night sweats. Common investigations will reveal a rise in erythrocyte sedimentation rate, C-reactive protein, and plasma viscosity on examination of a blood specimen in active disease. The human vascular system is endowed with a multitude of blood vessels, responsible for providing oxygen and nutrients to the deepest and farthest cells. Integrity of the vascular system keeps the body alive and warm. These vessels, namely the arteries (red), veins (blue), and capillaries, vary in size from an inch in diameter (aorta) to smaller, thinner vessels, barely visible to the human eye. Thence, the vasculitides are divided on the basis of size of vessels into large, medium, and small vessel vasculitis.
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Large vessel vasculitis has two types: giant cell arteritis and Takayasu’s arteritis. Giant cell or temporal arteritis usually victimizes patients older than 50 years. It is the most common type of primary systemic vasculitis affecting 200 per 1,000,000 population per year. It presents itself with throbbing headache of one side, facial pain, and claudicating of jaw when eating. It may affect the aorta, the largest vessel emerging from the heart, and its major branches, often it affects the temporal artery supplying the side of head. The inflammation is chronic and is characterized by the presence of giant cells and granulomas (any small aggregation of mononuclear inflammatory cells) in tissue sections, attributing the disease its name. Later in its course, the inflammation can be so intense that it may lead to loss of vision, usually sudden and painless, affecting part or the entire visual field. Double vision may also occur. The therapeutic strategy is that of high-dose corticosteroids (antiinflammatory agents) until the disease goes into remission. The patient is kept on a low-maintenance dose for two years to avoid relapse and visual loss. Biopsy is the confirmatory test. The disease is monitored by analyzing serum CRP, ESR, and plasma viscosity. Takayasu’s arteritis is also an inflammation (fibrous thickening) of the aorta and its main branches, but it occurs in younger patients below 50 years of age. It is most common in Asia and the Far East, affecting primarily women younger than 40. It is characterized by involvement of eyes and weakening of pulses in arms (pulseless disease). If the disease affects the vascular supply to the arms, head, neck, and heart, it is called aortic arch syndrome and it presents as claudication of the arms, loss of arm pulses, variation in blood pressure if recorded from both arms of more than 10 mm Hg, arterial bruits, angina, back flow of blood into the left ventricle of the heart, dizziness and syncope (temporary loss of consciousness), stroke, and visual disturbances. If the disease affects the descending branches of aorta, it is termed descending aortic syndrome, affecting the intestines, urinary system, and hypertension secondary to renal ischemia. ESR and CRP are markers but magnetic resonance imaging (MRI) and angiography are diagnostic tests. Treatment is with steroids or other cytotoxic adjuvant drugs such as cyclophosphamide.
1738 Vasculitis The medium vessel vasculitis is categorized into polyarteritis nodosa inflammation and Kawasaki disease. Polyarteritis nodosa means necrotizing or lethal of small and medium-sized vessels. It might be associated with hepatitis B infections in some patients. It may affect kidneys, lungs, heart, liver, spleen, gut, or peripheral nerves. Diagnosis is made on angiography of the affected vessel showing aneurysms (dilated pouches in a vessel) or biopsy of the affected nerve or muscle as a confirmatory test. Typical treatment is corticosteroid therapy except for hepatitis B involvement where an adjuvant antiviral like interferon alpha may be added with a high-dose short course of steroids. Kawasaki disease, affecting children younger than 12 years, is a more serious disease featuring coronary artery disease and may lead to myocardial infarction. It affects large, medium, and small arteries associated with mucocutaneous lymph node syndrome. Diagnosis is made on an echocardiogram showing aneurysms and treatment is with high-dose intravenous immunoglobulins in very early disease to prevent further aneurysms. Small vessel vasculitides involving only the microvessels are being acknowledged more frequently, mainly because of more research and awareness. The early symptoms of these disorders are nonspecific with fever, malaise, weight loss, and muscle and joint pains. The patients in which these symptoms are persistent should be screened for antineutrophilic cytoplasmic antibodies (ANCA), along with ESR, CRP, and urine examination for blood cells. If diagnosis is not made in time, it may lead to fateful kidney or lung damage. In patients who are ANCA positive, the vasculitis is of three types: Wegener’s granulomatosis, microscopic polyangitis, and Churg-Strauss syndrome. Wegener’s granulomatosis causes inflammation of small to medium-sized vessels and causes inflammation of the respiratory tract and kidneys. The three hallmarks of Wegener’s are granulomatous vasculitis of small to medium-sized vessels, granulomas in upper respiratory tract, and inflammation in kidneys (crescentic glomerulitis). Limited Wegener’s is the term give to the condition when the full triad is not manifested in a patient. Upper respiratory tract infections are extremely common and include sinusitis, nasal bleeding and crusting, infections of the middle ear, and constriction of the wind pipe (trachea). However, it may have lung involvement as well with cough, bloody sputum, and breathlessness, which may advance to lethal pulmonary
hemorrhage (bleeding into the lungs). In 80 percent of people, the kidneys are also affected; resulting is loss of proteins in urine, examined by dipstick testing and microscopy. Other associated features are purpuric rashes (purple spots), nail fold infarcts, multiple eye complications, bleeding into the gut, ischemia of the heart, and neurological symptoms causing pain sensations. Microscopic polyangitis has many similarities to Wegener’s other than involvement of upper respiratory tract infections which may not occur in polyangitis. The diagnosis is made on biopsy and presence of ANCA detected by enzyme-linked immunosorbent assay (ELISA) and indirect immunofluoresence. Treatment strategy comprises induction of remission and the maintenance of remission. Steroids, cytotoxic drugs, and plasma exchange methods are employed. Five-year survival rate is over 80 percent. Churg-Strauss syndrome is seen in people with allergic tendencies, usually asthma. It may affect heart, lung, and organ circulation. Purple rashes and nodules under the skin are common presentations. Inflammation of the kidney is also common. Diagnosis is made on the basis of skin, lung, and kidney biopsy and raised eosinophils in blood sample. ANCA may not be positive in all subjects. High-dose steroids alone provide satisfactory therapy with alleviation of asthma. A variety of patients who are ANCA negative can also be classified as having vasculitis. These include the following: • Henoch-Schonlein purpura, affecting skin, gut, and kidneys in children, which resolves itself and only supportive treatment is required • Cryoglobulinemic vasculitis, affecting only skin and kidneys, associated with hepatitis C infection in 80 percent of individuals • Isolated cutaneous leukocytoclastic vasculitis, associated with drug allergy • Goodpasture’s disease The two most common mechanisms of any type of vasculitis are the direct invasion of vascular wall by infectious agents and immune-mediated mechanisms. Infections could be bacterial, fungal, viral, rickettsial, or spirochetal. Infections can sometimes induce an immune-mediated noninfectious vasculitis. It is critical to distinguish between the two causative mechanisms because antiinflammatory and immunosuppressive therapy will be useful for immune-mediated vasculitis but would be potentially harmful for noninfectious
Venezuela
type. Physical injury such as toxins, chemical, and mechanical injury can also cause direct vascular damage. SEE ALSO: Coronary Disease; Hepatitis. Bilbiography. Nicholas A. Boon, et al., eds., Davidson’s
Principles and Practice of Medicine, 20th ed. (Elsevier, 2006); Richard Donnelly and Nick J M London, “ABC of arterial and venous disease: Ulcerated lower limb,” Evid Based Med (v.320, 2000); Norman W. Dorland, Dorland’s Pocket Medical Dictionary, 25th ed. (Saunders, 1995); Graham Douglas, et al, Macleod’s Clinical Examination, 11th ed. (Elsevier, 2005); Vinay Kumar, et al., Robbins and Cotran Pathologic Basis Of Disease, 7th ed. (Saunders, 2004). Sidrah Farooq Independent Scholar
Venezuela Venezuela is located on the northern coast of South America, bounded by Brazil, Guyana and Colombia on the south and the Caribbean Ocean on the north. When Christopher Columbus arrived in 1498, he named the area Tierra de Gracia, or the Land of Grace. It is one of the world’s most bio-diverse areas, containing within its borders both the northern tip of the Andes Mountains and the northern edge of the Amazonian rainforest. The broad Orinoco River flows across the middle of the country, and Angel Falls, the world’s highest waterfall, lies on the Churún River in central Bolivar state. Venezuela is a founding member of OPEC and one of the world’s top petroleum producers, as well as a leading producer of coffee and cocoa. Yet, despite its material wealth, many Venezuelans continue to suffer from poverty and malnutrition. The population is 26,034,000 and increasing at 1.486 percent annually. The birth rate is 21.22 per 1,000 and the death rate is 5.08 per 1,000. Median age is 24.9 years. Life expectancy is 70.24 years for males and 76.48 years for females. Gross national income is $4810 per capita, with 38 percent of the population living below the poverty level, and 8 percent living on less that $1 a day. Oil is the driving force of the economy, comprising 90 percent of export earnings and 30 percent of the gross domestic product. Most Venezu-
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elans work in industry or services, with just 13 percent of the population working in agriculture. Many of the communicable diseases that have impacted Venezuelans most over the decades are beginning to wane. Malaria is decreasing, although it was still prevalent throughout a quarter of the country in the late 1990s. Dengue fever, both hemorrhagic and classic, are endemic in several regions, as is onchocerciasis, or river blindness. Three million people live in at-risk areas for Chagas’ disease. There was a yellow fever outbreak in 2004 after years of relative quiet. At the same time, plague seems to be dormant, and cases of leprosy, schistosomiasis, Venezuelan hemorrhagic fever, and equine encephalitis are increasingly sporadic. Based on somewhat limited reporting, the prevalence rate for HIV/ AIDS is believed to be around 0.7 percent. As Venezuela develops a more modern economy, health concerns are shifting from communicable to non-communicable disorders. Obesity rates are climbing, and more people are becoming accustomed to a sedentary lifestyle. Smoking and alcohol use are other leading risk factors. The leading causes of death are now cardiovascular disease, accidents and violence, and cancers. In 2000, about 600,000 Venezuelans had diabetes. By 2020, the World Health Organization estimates the figure will be closer to 1.6 million. Children have been faring better in recent years. Mortality rates are low, with 18 deaths per 1,000 in infants and 21 deaths per 1,000 for children between age 1 to 5. Immunization rates are in the 90th percentile, and the country is polio and diphtheria free. UNICEF notes that despite these gains, serious problems exist. By their estimates, 21 percent of children are malnourished and 13 percent show signs of stunting. Access to education is unequal, particularly for children of African or indigenous descent. Adolescent pregnancy rates have climbed, but the overall fertility rate for Venezuelan women is dropping, now at 2.55 children per woman. Contraceptive use is at 77 percent. Most women receive prenatal care, and 95 percent give birth with the help of trained attendants, cutting the maternal mortality rate to 96 deaths per 100,000. Abortion is illegal in Venezuela under any circumstances, putting an unknown number of women at risk for complications and death stemming from unsafe procedures. The presidency of Hugo Chavez has brought great chance to the Venezuelan healthcare system. Under his
1740 Vietnam stated policy of using the country’s vast oil wealth to improve life for all the people, in the spring of 2003, the government launched Mision Bario Adentro, bringing healthcare into poor neighborhoods and communities that had been traditionally undeserved by the system. Some Venezuelan doctors refused to work in the worst, or most isolated areas, so Chavez imported 20,000 Cuban doctors to take the posts. Venezuela is now trying to emulate the Cuban system, offering free medical training in return for community service. See Also: Chagas Disease; Dengue; Diabetes; Healthcare,
South America; Onchocerciasis.
Bibliography. Green Left Online, “Beginnings of a So-
cial Health Revolution in Venezuela,” www.greenleft.org. au/2007/697/36216 (cited June 2007); The Joint United Nations Programme on HIV/AIDS, “Sierra Leone, “Epidemiological Fact Sheet 2004 – Venezuela,” www. data.unaids.org/Publications/Fact-Sheets01/venezuela_ en.pdf?preview=true (cited June 2007); “Venezuela,” www. cia.gov/library/publications/the-world-factbook/geos/ ve.html (cited June 2007); “Venezuela: Health in the Americas, 1998,” Pan American Health Organization (PAHO). www.paho.org/english/HIA1998/Venezuela.pdf (cited June 2007); United Nations Children’s Fund, “At a Glance: Venezuela (Bolivarian Republic of) Statistics,” www.unicef.org/ infobycountry/venezuela_statistics.html (cited June 2007); World Health Organization, InfoBase Home Page, www. who.int/infobase/report.aspx (cited June 2007). Heather Michon Independent Scholar
Vietnam Vietnam is located in Southeast Asia, bordered on the north and west by China, Laos and Cambodia, and to the east by the South China Sea. With rich farmlands fed by the Red and Mekong River deltas, Vietnam had an ancient and largely peaceful history until the 20th Century. Today, it is struggling to recover from the devastation of the Indochina War (1946-54) and the Vietnam War (1959-75). More than a million Vietnamese were killed and more than a million displaced during those wars, and the nation’s infrastructure was
decimated. Corruption and mismanagement by Socialist leaders in the post-war period led to high rates of unemployment and widespread poverty. The economy is just beginning to rebound, due to investments in tourism and high-tech industries. The population is 85,200,000 and growing at 1 percent annually. The birth rate is 16.63 per 1,000 and the death rate is 6.19 per 1,000. Median age is 26.4 years. Life expectancy is 68.27 years for males and 74.08 years for females. Gross national income is $620 per person, with 19.5 percent living in poverty. Almost 60 percent of Vietnamese still rely on agriculture for work. In 2003, there were 63 diagnosed cases of Severe Acute Respiratory Syndrome (SARS), leading to 5 fatalities. Vietnam has also seen a number of infections from the H5N1 avian flu. Normally harmless to humans, within Vietnam it often turns into HPAI, or highly pathogenic avian influenza, and has killed 42 of the 93 known to be infected in 2005–06. As Vietnam modernizes, non-communicable disorders are taking a larger role in public health. Tobacco and alcohol use are common, and are expected to lead to heightened rates of cardiovascular disease. Cancers are also on the rise, although it is often not diagnosed until a late stage. With increased urbanization, the country is already seeing an rise in traffic and industrial accidents, murders, suicides, accidental poisoning, drug overdoses, and mental health problems. Child mortality has improved dramatically since 1990, with just 16 deaths per 1,000 in infants and 19 deaths per 1,000 in children aged 1 to 5. Three quarters of under-5 deaths are accidents in the home (primarily drowning) and traffic accidents. Immunization rates are high and 97 percent of children are enrolled in school. However, the economic changes sweeping the country are having an impact on children and families. More adolescents are using drugs, and 1 in 10 AIDS victims is under the age of 19. Women in Vietnam suffer a higher incidence of illhealth during their lifetimes, but are less likely to seek medical attention and more likely to self-treat their illnesses. This seems to stem largely from cultural expectations about a woman’s role in the family. The total fertility rate is low, 1.89 children per woman. Almost 80 percent of women use contraception. Eighty-five percent have skilled attendants during childbirth. Maternal mortality is 130 deaths per 100,000 live births.
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Vietnam has a large medical infrastructure, with 730 general hospitals, 101 specialized hospitals, 946 primary care facilities, and 11,375 clinics. The pool of medical personnel includes 48,200 physicians and 50,000 nurses. The system is improving, but still needs to be extended into some of the more remote and rural parts of the country. See Also: AIDS; Alcohol Consumption; Healthcare,
Asia and Oceania; Severe Acute Respiratory Syndrome (SARS); Smoking. Bibliography. “A guide to statistical information at
WHO,” World Health Organization. www.who.int/whosis/ en/index.html (cited June 2007); “Country Health Profile: Viet Nam,” WHO/Western Pacific Regional Office. www. wpro.who.int/countries/vtn/ (cited June 2007); “Vietnam,” CIA World Factbook. www.cia.gov/library/publications/ the-world-factbook/geos/vm.html (cited June 2007); “Viet Nam – Statistics,” UNICEF. www.unicef.org/infobycountry/vietnam_statistics.html (cited June 2007); “Viet Nam,” UNAIDS: The Joint United Nations Programme on HIV/ AIDS. www.unaids.org/en/Regions_Countries/Countries/ viet_nam.asp (cited June 2007); “WHO Global InfoBase: InfoBase Home Page,” World Health Organization. www. who.int/infobase/report.aspx (cited June 2007). Heather Michon Independent Scholar
Viral Infections There are more than 400 different viruses that are capable of infecting humans. Other viruses such as bacteriophages (viruses that infect bacteria), plant viruses and animal viruses also exist. There are many means by which a viral transmission can occur. For instance, they can be airborne viruses, arthropod-borne viruses, person-to-person transmitted viruses, food- and waterborne viruses, sexually transmitted viruses, and prions. Infection occurs when a virus takes over the cell machinery and makes many copies of it. While the virus replicates, host cells are either destroyed or are reduced in their normal functional activity. The progeny that is released then continues the cycle by affecting other cells and multiplying to form more copies of the
A virus under magnification: A viral infection may be systemic or localized, depending upon the type of virus that infects the body.
virus. It ultimately ends up destroying the host cells completely. A virus particle or virion can be made up of a single- or double-stranded DNA or RNA. Virions are obligate intracellular pathogens that absolutely require a host cell to reproduce. Thus, viruses work in a simple way and yet give rise to a range of diseases by means of genetic variation. This type of simplicity of viruses that leads to intense pathological features, clinical consequences and death is what makes virology (study of viruses) important. Infection caused by virus can affect all types of body tissue. Symptoms for viral infections include headache, high fever, weakness, muscle pain, nausea, vomiting, diarrhea, and abdominal pain. Although there is no accurate treatment available for viral infections, physicians usually treat them with antibiotics. Antiviral drugs against some viruses are also available. A viral infection may be systemic (spread throughout the body) or localized (infect only at one location) depending upon the type of virus that infects. Infectious Mononucleosis Epstein-Barr virus is a chief cause of infectious mononucleosis or mono. A person usually gets infected by transmission of virus through oral contact. Kissing an infected person is a major mode of transmission. The virus can then spread to other organs of the body. Although most cases of mono occur due to Epstein-Barr virus infection, a virus known as cytomegalovirus is
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Viral Infections
also capable of resulting into this type of illness. Stress and anxiety are also linked to the cause of infection. Young adults are most susceptible. Shingles Shingles is a condition that affects adults due to reactivation of an infection caused by chicken pox virus. The varicella zoster virus, which causes chicken pox infection in early years, causes shingles in adults by remaining in a dormant state. The virus stays inactive in the brain tissue, spinal cord, or nerve cells for years. Reactivation from this state takes place in reaction to external factors that stimulate the virus to switch back to an active form. Stress, cancer, hormonal imbalance, and weakened immune system are examples of situations under which the virus might activate. These types of stimulations can cause many reoccurrences of the shingles infection. Shingles cannot be transmitted from person to person. On the contrary, an individual with no previous infection of varicella zoster virus can develop chicken pox if transmission of virus from a shingles-infected person takes place. Rashes or blisters with severe pain are an initial symptom. This pain may continue even after complete recovery from blisters resulting in a condition known as postherpetic neuralgia. All body parts are at equal risk of being affected. If the infection occurs in facial region or near the eyes of a patient, then it may lead to temporary paralysis of face and/or low vision. In addition, infection to auditory nerves may result in hearing problems. Dengue Dengue virus spreads infection to humans via mosquito bites. Aedes are female mosquitoes (the same mosquitoes that transmit malaria) that are capable of infecting with dengue. This virus thrives around water pools and in unsanitary conditions. Cleanliness to eradicate the Aedes mosquitoes is an important measure to be taken when an area is threatened by dengue. Central and south America, southeast Asia, China, India, Caribbean, Africa, and Middle East are areas most hit by this arthropod-borne infection. Rabies Rabies virus spreads to humans via an intermediate host that is infected. For example, when an infected animal bites or scratches a person, it can transfer the
virus. When the infection is passed on, the rabies virus finds its way into the nearest nerve ending that will lead it to the brain leading to a life-threatening illness. Household pets can be vaccinated against rabies virus to prevent them from getting infected. However, wild animals such as bats, foxes, coyotes, and raccoons seldom transmit the infection to a human host. Influenza Influenza viruses transmit from person to person and are causative agents of a highly contagious, often serious acute respiratory illness. The virus is passed by a respiratory droplet transmission. For example, coughing or sneezing by an infected individual can release the influenza virus in the air. The virus then can infect other available hosts. It takes about one to four days for influenza virus to incubate in the host before it starts shedding and becomes infectious. Influenza in immunocompromised patients can be critical. In addition, patients with severe influenza infection may suffer from secondary acute infections caused by bacteria and other pathogens. Symptoms may include headache, fever, cough, sore throat, and malaise. Influenza viruses are of different subtypes. For example, the avian influenza virus responsible for causing bird flu is an influenza A virus, also known as the H5N1 virus. H5N1 virus does not spread from human to human. Study of influenza virus is important as it gives rise to pandemics from time to time. This happens as the virus forms a new strain by undergoing a genetic shift. A new strain of infectious virus originates and affects the human population when an influenza virus from bird and a human influenza virus combine to form a new strain in an intermittent host reservoir, such as a pig. This new virus from pigs is then capable of infecting humans. Although the avian flu virus is not directly harmful to humans, H5N1 cases have occurred due to direct handling of birds. Influenza vaccines can prevent a person from getting an infection. Most cases of influenza are treated by using antiviral drugs amantidine and rimatadine. H5N1 virus in Asia is now resistant to these two antiviral and is provided by using other antiviral medications such as oseltamavir and zanamavir. Vaccine for H5N1 is yet to be discovered and so there is no prevention regimen available at present. Avian flu in Asia has led to severe
Virology
illness and death similar to that of 1918 pandemic of Spanish flu. The most susceptible age group then was young adults and elderly patients older than 65 years. It was a devastating disease that killed more people than World War I. Means of Viral Diseases Different viruses give rise to many types of diseases. Airborne viral diseases such as chicken pox, shingles, and influenza can occur directly or indirectly through the respiratory system. Arthropod-borne viral diseases, which include West Nile virus and yellow fever, can be transmitted to humans from arthropod vectors that infect other human or animal hosts. Viral diseases such as AIDS, genital herpes, hepatitis, rabies, and infectious mononucleosis are transmitted from person-to-person contact. Sexually transmitted diseases (STDs) usually spread through oral or fecal sexual contact. It is transmitted via the medium of blood or sputum. Food- and waterborne viruses enter the body via oral route and usually infect the intestinal system. They are shed in the feces of an infected person and can then spread to other individuals who come in contact. Acute viral gastroenteritis caused by rotavirus, hepatitis A, and poliomyelitis are examples of such viruses. Some viruses may spread by autoinoculation such as direct or indirect contact, scratching, or through an open wound. Common skin warts caused by human papillomaviruses fall under this category. A prion is a small protein particle that remains dormant for a long time before the onset of symptoms. Kuru, fatal familial insomnia and progressive multifocal leukoencephalopathy are few examples. Because most prions infect the central nervous system, infections caused by them are chronic and life threatening. SEE ALSO: AIDS and Infections; Dengue; Genital Herpes;
Guillain-Barre Syndrome; Herpes Simplex; Immune System and Disorders; Immunosuppression; Influenza; Measles; Meningitis; Mumps; Rabies; Smallpox; Urinary Tract Infections; Virology. Bilbiography. American Medical Association Family
Medical Guide, 4th ed. (Wiley, 2004); Department of Health and Human Services: Centers for Disease Control (CDC) and Prevention, “Influenza Flu: Clinical Description and
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Diagnosis,” www.cdc.gov/flu/professionals/diagnosis/ (cited January 2007); Martins S. Lipsky, American Medical Association: Concise Medical Encyclopedia (Random House Reference, 2007); MedicineNet.Com: We Bring Doctors Knowledge to You, “Definition of Viral Infection,” www. medterms.com/script/main/art.asp?articlekey=11557 (cited January 2007); Prescott Harley Klein, et al., Microbiology, 5th ed. (McGraw-Hill, 2002); Stanford University, “The Influenza Pandemic of 1918,” http://virus.stanford. edu/uda/ (cited January 2007). Jinal Mehta University of Missouri-Kansas City
Virology Virology is the study of virus structure, assembly, biology, and pathogenesis (ability to cause disease). Virology is often classified with bacteriology (the study of bacteria) under the term “microbiology” to include the study of all microscopic organisms. Virology is critical for global health as it is how scientists gather information about viral diseases. Numerous infectious diseases are caused by viruses, and it is one of the goals of the Centers for Disease Control (CDC) to prevent and control viral outbreaks in the United States and around the world. Virus Structure Viruses are comprised of a heterogeneous group of microorganisms that vary in size, morphology, host range, complexity, replication strategy, and pathogenesis. All viruses are obligate intracellular parasites that depend on a host cell for replication. A single virus particle is termed a virion, and the genome of a given virus can be made up of single or double-stranded RNA or DNA. For example, the West Nile virus genome is a single strand of RNA of positive polarity, while the smallpox virus genome is double stranded DNA. There are two main classes of viral proteins: structural and non-structural proteins. The structural proteins make up the viral particle. Capsid proteins surround the genome to comprise the nucleocapsid while the matrix and envelope glycoproteins, together with the lipid envelope comprise the outer layer of enveloped viruses. Non-structural proteins
1744 Virology are involved in virus replication and other processes such as host immune evasion. Virus Taxonomy Similar to other biological classification schemes, the classification system for viruses includes the order, family, genus, and species. In general, virus families share common characteristics, such as type of nucleic acid, morphology, and replication strategy. Family names end in “–idae”, for example the Paramyxoviridae family. Genus names end in “–virus” and members of the same genus often share serologic cross-reactivity due to common proteins recognized by antibodies. Mumps virus is a species of the Rubulavirus genus and is part of the Paramyxoviridae family.
nome are also produced. The strategy that a given virus uses will depend heavily on the type of nucleic acid of the genome. In general, DNA viruses such as herpes simplex virus will replicate in or near the nucleus, while RNA viruses such as SARS virus will replicate in the cytoplasm. Once the viral genome and structural proteins have been synthesized, the newly formed structural proteins assemble around the newly replicated viral genome during assembly. The last step of viral replication involves virus maturation or egress from the host cell. Newly formed infectious virions typically leave the host cell either by lysis of the cell or by budding through a cellular membrane, and these virions are free to infect new naïve host cells.
Virus Replication The general replication cycle of viruses can be divided into various steps: adsorption, penetration, uncoating, replication, assembly, and egress. During the first step (adsorption or attachment), a specific viral protein binds to a specific receptor on the host cell surface. For example, polio virus surface proteins bind to CD155 (also called the polio virus receptor) on host cell membranes. The attachment step is often essential for virus infection and research in the area of viral pathogenesis frequently focuses on adsorption. Following adsorption, viruses penetrate and gain entry into a host cell either by translocation across the membrane, pinocytosis, or membrane fusion of the viral and cell envelopes. For example, the causative agent of chickenpox and shingles (varicellazoster virus) enters the host cell through fusion of the viral and host cell membranes, thereby allowing the nucleocapsid to enter the cell. Penetration is followed by uncoating, where the viral capsid and other viral proteins disaggregate from the viral genome. Often, uncoating occurs simultaneously with penetration of the virus. The fourth step of virus replication involves the transcription, translation, and replication of the viral genome. This step can vary widely and different virus families use different replication strategies. Some viruses replicate in the cytoplasm, while others replicate in the host cell nucleus. In general, RNA transcripts generated from the viral genome are used to synthesize viral structural and nonstructural proteins. Multiple copies of the viral ge-
Viral Pathogenesis There are many potential outcomes of a viral infection, ranging in severity from asymptomatic, acute, persistent, and chronic infections. Most individuals infected asymptomatically show no signs of infection and completely recover, although some may still be carriers and can pass virus particles to susceptible individuals. Acute viral infections proceed rapidly, but the virus can also be rapidly cleared from the body. Most cases of rubella (German measles) follow this trend as infected children exhibit a mild respiratory infection and rash, but the symptoms are self-limiting and complete recovery usually follows. Persistent viral infections include latent infections which are characteristic of members of the Herpesviridae family. Herpes simplex virus is able to survive in a latent state in cells of the nervous system. Following a stimulus (i.e. stress), the virus is able to re-activate and cause the characteristic herpes virus lesions. Persistent virus infections can also be in the form of a chronic infection, whereby the virus remains in an infectious state for months, years, or even a lifetime. Hepatitis B virus and HIV are examples of viruses that typically cause chronic infections. Many viral factors contribute to the various outcomes of an infection. Tissue tropism is important as the severity of a viral infection often depends on the tissue or body part that is infected. Tissue tropism is largely determined by the presence or absence of viral receptors on the surface of host cells. For example, influenza A virus binds to sialic acid on respiratory
Vitamin A Deficiency
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epithelial cells, thereby causing respiratory symptoms (the flu). Conversely, measles virus binds to a protein found on nearly all cell types, and causes a systemic infection throughout the body. Virulence factors expressed by viruses also play an important role in viral pathogenesis. Common virulence factors include protein products that are toxic to host cells. A rotavirus nonstructural protein (NSP4), for example, acts as an enterotoxin to induce diarrhea. Other viral virulence factors allow the virus to spread more easily, replicate faster, or survive inside the host for long periods of time. Some virulence factors allow viruses to evade or defeat the host immune system. Poxviruses, for example, are well-known for their ability to modulate the immune system. Many viruses in this family secrete proteins that mimic or disrupt cytokines and other important components of the host immune system in order to “hide” from the immune system during an infection.
Summary Viruses are a diverse group of obligate intracellular parasites that vary greatly in structural composition, replication strategies, and virulence factor production. Studies of viral replication and virulence factor mechanisms have and will continue to aid in the development of specific treatments, vaccines, and immunization strategies for viral infections. The global eradication of smallpox virus is the crowning achievement for the concept of vaccination and the field of virology, and hopefully the elimination of other viral diseases will follow. The continuing study of viruses is critical to our increasing understanding of infectious disease with the goal of improving global health.
Effect of Host Factors on Viral Pathogenesis In addition to viral factors, numerous host factors also contribute to the outcome of a viral infection. The severity of many viral illnesses varies with age, with the young and elderly generally being the most seriously affected. For example, rubella virus infections are extremely serious and can result in death in a developing fetus, whereas childhood rubella infection generally involves a rash and is self-limiting. Nutrition and general state of health also play a major role in the severity of viral infection. Healthy and well-nourished individuals tend to experience milder symptoms in response to virus infection than those individuals that are malnourished, stressed or immunosuppressed. Another major host factor affecting virus infectivity is prior immunity. The existence of specific antibodies or memory T cells against a virus normally greatly reduces a person’s susceptibility to infection. This adaptive immunity can be either the result of previous exposure to the same virus or from vaccination. Because prior immunity is so successful in protecting individuals from viral infections, childhood immunization has become a cornerstone in the ability of global heath initiatives to greatly reduce the frequency and severity of many viral diseases.
Medical Microbiology, 23rd ed. (Lange Medical Books/ McGraw-Hill, 2004); Y. Dong, et al., Proc. Natl. Acad. Sci. (v.94, 1997); J. B. Johnston and G. McFadden, J. Virol. (v.77, 2003); D. M. Knipe and P. M. Howley, eds., Fields Virology, 4th ed. (Lippincott Williams & Wilkins, 2001).
SEE ALSO: Chickenpox; Common Cold; Hepatitis C; Her-
pes Simplex; Immunization/V63accination; Infectious Diseases (General); Influenza; Measles; Mumps; Polio; Rabies; Rubella; SARS; Smallpox; Viral Infections; West Nile Virus. Bilbiography. G. Brooks, et al., Melnick, and Adelberg’s
Tracey A. Hunt, Ph.D. Kansas City University of Medicine and Biosciences John M. Taylor, M.Sc. University of Alberta
Vitamin A Deficiency Vitamin A refers to the fat-soluble retinol compound that is essential for various biological functions. Retinaldehydes and retinoic acids are biologically active derivatives from retinol. 11-cis retinaldehyde is an essential form of vitamin A that is required for normal vision. Retinoic acid is essential for normal cell morphogenesis, growth, and differentiation. Vitamin A is also needed for iron utilization and normal immunity. Deficiency of vitamin A can lead to visual impairment and skin lesions. However, they can be effectively treated with appropriate levels of the vitamin.
1746 Vitamins and Minerals Dietary Sources and Epidemiology Vitamin A can be derived from metabolites of carotenoids. In nature, carotene is the most prevalent carotenoid in the food supply. Liver and fish are excellent sources of preformed vitamin A. Sources of pro-vitamin A carotenoids include dark green and dark-colored vegetables and fruits. Developing infants and children are at most risk for vitamin A deficiency because breast and cow milk contain low levels of vitamin A. In developing countries vitamin A deficiency is one of the common causes of blindness, affecting more than a quarter of a million children each year with a 50 percent mortality rate within the year. Increased mortality in children is due primarily from infectious diseases, measles, respiratory diseases, and diarrhea. In the United States, vitamin A deficiency is typically due to diseases associated with malabsorption of fat such as celiac sprue. Because 90 percent of absorbed vitamin A is stored in the liver, zinc deficiency can also interfere with the release of vitamin A from storage. Chronic alcoholism can also cause deficiency because alcohol competes for alcohol dehydrogenase, a key enzyme required for the conversion of retinol to retinaldehyde in the eye. Other causes of deficiency include interference from drugs such as neomycin and mineral oil laxative abuse. Clinical Symptoms and Treatment Patients often present to their doctors complaining of difficulty in seeing in the dark (night blindness). This is due to low levels of 11-cis retinaldehyde, an important molecule required for dark adaptation of vision. Other symptoms of deficiency include dryness of the conjunctiva (xerosis), corneal ulcers and necrosis (keratomalacia), hyperkeratotic skin lesions (increased keratinization of the epithelium), and development of small white patches on the conjunctiva (Bitot’s spots). Normal range of serum vitamin A level is 30–65 mg/dL. Serum levels below the norm are commonly seen in advanced stages of deficiency. Night blindness, poor wound healing, and other signs of deficiency can be effectively treated with appropriate levels of vitamin A. Excessive levels of vitamin A should be avoided as the vitamin is fat soluble and can accumulate in the body, leading to symptoms of vitamin A toxicity and can lead to congenital malformations in women who are pregnant.
SEE ALSO: Birth Defects; Blindness; Disease and Poverty;
Nutrition.
Bilbiography. A. Catharine Ross, “Retinoid Production
and Catabolism: Role of Diet in Regulating Retinol Esterification and Retinoic Acid Oxidation,” Journal of Nutrition (v.133/1, 2003); A. Catharine Ross, “Vitamin A Supplementation as Therapy—Are the Benefits Disease Specific?” American Journal of Clinical Nutrition (v.68/1, 1998); “Vitamin A Deficiency,” e-Medicine, www.emedicine.com/ med/topic2381.htm (cited February 2007). Andrew J. Waskey Dalton State College
Vitamins and Minerals Vitamins and mineral are chemical compounds used by the body to metabolize food. Although a part of an organism’s food, that is, its nutrients, vitamins and minerals have no calories. They are tiny unseen chemicals in foods nutrients which act as catalysts to promote growth and health. Catalytic reactions increase the speed and efficiency of chemical reactions usually without being consumed in the reaction. Vitamins make it possible for the body to react efficiently with foods to convert them into nutrients that can then perform essential biochemical reactions. Vitamins are “micronutrients” because only a small amount of the essential vitamin is necessary for the chemical reactions that convert food into energy and living tissues. The Food and Nutrition Board of the National Research Council has developed the Recommended Daily Allowance (RDA) of vitamins needed daily for good health. The actually amount of vitamins and minerals needed varies between individuals. Most people get their RDA from the food they eat and do not need vitamin supplements. The amounts of vitamins needed are very small, but the consequences of their absence can be severe. A vitamin deficiency disease is a condition caused by a metabolic or dietary deficiency. The absence of each vitamin can contribute to a specific disease. Several infamous vitamin deficiency diseases in humans are scurvy (Vitamin C), rickets (Vitamin D), Beriberi (thiamine) and pella-
gra (niacin). These diseases are now unknown in the developed world where fortified food products and vitamin supplements are readily available. However, they are common in the tropics and other areas of the undeveloped world. The World Health Organization (WHO), governments, and many non-governmental agencies (NGOs) have made studies of the geography and demographic factors contributing to vitamin deficiency diseases. For example iodine is needed in small quantities by the thyroid gland to make both thyroxine and triiodothyronine. Without iodine, for which sea salt is a vital source, the body will develop goiters and other serious health problems. People living in areas remote from the sea often have goiter. Fortunately, iodine is easily added to table salt that is mined as rock salt. Vitamin deficiencies have been classified as either primary or secondary. Primary vitamin deficiencies are caused by not getting enough of a particular vitamin from the food that is eaten. Scurvy in healthy young adults during long sea voyages is an example. In contrast a condition of secondary vitamin deficiency is caused by either an underlying disorder which is metabolic in nature or by a lifestyle factor. The underlying disorder may be due to cancer or some other disease such as a mal-absorption disease. The lifestyle factor may be due to the excessive consumption of alcohol, smoking tobacco, the abuse of drugs and restrictive diets. Moreover, the use of prescription medications (usually for long periods of time) may interfere with either the absorption or utilization of the vitamin by the body’s chemistry. People who eat normal diets are not likely to develop vitamin deficiencies. People on restrictive diets are at risk of developing a vitamin deficiency disease which can lead to a painful death. Vitamin deficiencies can cause severe problems, but so can excess amounts of vitamins. Some vitamins when taken in large amounts have side effects that increase with the dosage. Overdosing on vitamins from food that is eaten is remote. However, the excessive use of vitamin supplements can cause nausea, diarrhea and vomiting. Vitamin abuse can occasionally even be fatal. Usually there are not permanent consequences if the doses are reduced to normal levels. The dosage of vitamins tolerated by individuals varies widely with most cases of overdoses involving children under the age of 6 years.
Vitamins and Minerals
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The thirteen known vitamins are vitamin A, (retinol), thiamine (vitamin B1), riboflavin (vitamin B2), niacin (nicotinic acid), pyridoxine (vitamin B6), pantothenic acid, cobalamin (vitamin B12), biotin, folate, vitamin C (ascorbic acid), vitamin D, vitamin E, and vitamin K. Five vitamins are manufactured in the body by bacteria. They are manufactured in sufficient quantities that dietary supplements are not needed. The five vitamins manufactured in the body are biotin, niacin, pantothenic acid, vitamin D and vitamin K. Vitamins are either fat soluble or water soluble. Vitamins A, D, E and K are fat-soluble and are stored in the liver for long periods of time. The water soluble vitamins are thiamine (vitamin B1), riboflavin (vitamin B2), niacin (nicotinic acid), pyridoxine (vitamin B6), pantothenic acid, cobalamin (vitamin B12), biotin, folate and vitamin C (folic acid). Vitamin A is actually a family of vitamins that are fat-soluble, some of which are derived from animal products such as egg yokes, milk and liver. Probably
If a daily diet includes foods of all groups in adequate amounts, it will be balanced and enough vitamins for health will be available.
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Vitamins and Minerals
the most active form of vitamin A is retinol. It can be converted to retinal and to retinoic acid or other forms of vitamin A. Some plants are also important as sources of vitamin A indirectly, such as those containing orange pigments called carotenes or “provitamin A” that can be converted by the liver into retinol. If fetuses and babies do not get enough vitamin A they will suffer from vitamin A deficiency (VAD) which can lead to problems with sight. Blindness, loss of night vision, and the loss of the fetus are very possible consequences from VAD. These symptoms can be seen in millions of people in developing countries especially in Africa and Southeast Asia. The spread of HIV/AIDS in these areas has increased the likelihood of VAD, especially in the third trimester where the demand for vitamin A by both the mother and the developing fetus are greatest. Adults who do not get enough vitamin A can also develop eye problems. Xerophthalmia is a condition of the eye in which the surface dries. The dryness increases the likelihood of eye infections and blindness. Loss of night vision is an early symptom of VAD. vitamin A forms part of the two pigments that help the eyes adjust to variations in the intensity of light. Vitamin B is actually a complex of vitamins. It was at first thought to be a single vitamin but further research showed that it instead eight: thiamine (vitamin B1), riboflavin (vitamin B2), niacin, pyridoxine (vitamin B6), Pantothenic acid, biotin, cobalamin (vitamin B12), and folic acid. Thiamine (vitamin B1) is derived from green vegetables, nuts, soybeans, legumes, yeast, whole-grain and enriched breads and cereals. Pork is an especially rich source of thiamine. Without thiamine the vitamin deficiency disease of Beriberi can develop. Beriberi has been common in Asian countries were polished white rice has been eaten instead of the whole rice grain, whose outer husks contain thiamine. Riboflavin (vitamin B2) is found in a variety of foods including fish, liver, milk, poultry, greens, leafy vegetables and eggs. It is an active agent in growth and in healthy skin and eyes. Oxygen in the body that is used to convert food into nutrients uses riboflavin as a catalyst. Without riboflavin the skin around the mouth may develop cracks. In addition the lips may become inflamed and the tongue swollen. Scaly skin may develop around the eyes and ears while the eyes may become very sensitive to light.
Niacin (vitamin B3) is also called nicotinic acid. It is essential for thiamine and riboflavin reactions. The absence of niacin may cause the vitamin deficiency disease of pellagra which has commonly occurred among people whose diet was centered on corn (maize). It has frequently occurred in rural Africa, South America, southern American states and in institutions where the diet was very poor. Symptoms include scaly skin lesions, diarrhea, inflamed mucous membranes, delusions and mental confusion. Some proteins, especially those that contain tryptophan which is an amino acid, will prevent or minimize pellagra because tryptophan can be converted by the body into niacin. If tryptophan is present in the diet and much of it is used by the body for protein production niacin deficiency may still result. Milk, although it does not contain tryptophan or niacin can be converted by the body into niacin. Pyridoxine (vitamin B6) is an important catalyst in converting amino acids into nutrients. Symptoms of a vitamin B6 deficiency include skin and nerve damage. Pantothenic acid is converted by the body into coenzyme A. This organic chemical is a vital part of the conversion of nutrients into energy. Biotin is an important chemical in the body’s production of energy. It is used to convert fats into fatty acids which aid the energy process. Cobalamin (vitamin B12) is linked with folic acid. Cobalamin contains cobalt and works with folic acid to produce deoxyribonucleic acid (DNA). The body’s cells all contain DNA which instructs and guides cell activities. Without either vitamin B12 or folic acid the body will suffer from anemia. Pernicious anemia may be treated with small amounts of vitamin B12 usually through injections. Nerve damage can result without this vital vitamin. Folic acid (folacin) is the last of the vitamin B complex. It is crucial for the development of a fetus. Food sources for folic acid and cobalamin are eggs, milk and animal proteins such as liver. Vitamin C (ascorbic acid) is often called the antiscorbutic vitamin because it prevents or cures scurvy. It is also essential in the formation of collagen. Symptoms of scurvy include liver spots on the skin, especially on the thighs and legs, bleeding from the mucous membranes, weakening of the gums, loosening of the teeth, depression, malaise, and paleness. As the disease advances wounds may open on the skin
Vitiligo
and teeth may fall out. Death in the most advance cases is an inevitable result. Citrus fruits, tomatoes and other fruits such as strawberries, cantaloupe, raw cabbage are important sources of ascorbic acid. In the Arctic and elsewhere native peoples have not developed scurvy because they have eaten the whole of some animals such as the eyeballs of seals which contain vitamin C. Vitamin D is important in the prevention of rickets. It comes from several sources including sunshine. Vitamin E (tocopherol) is found in wheat germ, lettuce, many vegetables, Kiwi fruit, berries, eggs, milk, liver, fish and meat. It is an important chemical in the maintenance of cell membranes. Tocopherol has eight forms (isomers) and is an important antioxidant. Each form has its own biological function. Vitamin E prevents polyunsaturated fats from being oxidized into solid fats in the body. It also enables the capture of free radicals in the body. Vitamin K is a group of chemicals that are lipohilic and hydrophobic and are essential for the proper functioning of blood clotting. Good food sources include green leafy vegetables such as cabbage, cauliflower, kale, spinach. Pork liver is also an excellent source. Some of the “friendly” bacteria in the human intestinal tract also make vitamin K. Deficiencies of this vitamin are rare and almost always due to a very poor diet. In addition to vitamins there are over sixty minerals that are used in the body as part of it nutritional chemistry. Over twenty of these are essential for good health. Sodium for example is essential for overall health and calcium is necessary for the development of bones. Potassium is also important and enough can usually be obtained from a balanced diet. Bananas are a good source of potassium. Insufficient potassium in the elderly can cause temporary dementia. Iron is also an essential mineral that is needed by red blood cells to transport oxygen. Without enough iron the body can develop anemia. Vitamin C combined with the consumption of iron rich foods can aid in the body’s absorption and utilization of iron. Minor or trace minerals include boron, chromium, cobalt, fluorine, iodine, iron, manganese, molybdenum, selenium, silicon, vanadium and zinc. Other minerals that are major minerals requiring larger amounts for good health include phosphorous, sulfur, chlorides, and magnesium.
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Zinc participates in several aspects of cellular metabolism to promote growth, immune responses, reproduction and neurological functions. There are about one hundred enzymes that are zinc dependant as a catalyst. Selenium is another mineral that is important in the manufacture of proteins. Crohns disease can be worsened by the disease’s disruption of the body’s absorption of selenium. See Also: Birth Defects; Blindness; Disease and Poverty;
Nutrition.
BIBLIOGRAPHY. Phyllis A. Balch, Prescription for Nu-
tritional Healing: A Practical A-to-Z Reference to DrugFree Remedies Using Vitamins, Minerals, Herbs and Food Supplements (Penguin Group, 2006); Mary Dan Eades and Philip Lief Group, Doctor’s Complete Guide to Vitamins and Minerals (Dell Publishing, 2000); Alan R. Gaby, ed., AZ Guide to Drug-Herb-Vitamin Interactions: Improve Your Health and Avoid Side Effects when Using Common Medications and Natural Supplements Together (Crown Publishing Group, 2006); Shari Lieberman and Nancy Bruning, Real Vitamin and Mineral Book (Avery, 2003); Frank L. Meyskens and Kedar N. Prasad, eds., Vitamins and Cancer: Human Cancer Prevention by Vitamins and Micronutrients (Springer-Verlag, 1986); Earl Mindell and Hester Mundis, Earl Mindell’s New Vitamin Bible (Warner Books, 2004); Michael T. Murray, Encyclopedia of Nutritional Supplements (Crown Publishing Group, 1996); Annette B. Natow and Jo-Ann Heslin, The Vitamin and Mineral Food Counter (Simon & Schuster, 2004); Harold M. Silverman, et al., The Vitamin Book (Bantam Books, 1999); Andrew Weil, Vitamins and Minerals (Random House, 1998). Andrew J. Waskey Dalton State College
Vitiligo Vitiligo is a condition in which the skin loses melanocytes (skin cells that produce pigment). This results in lighter than normal patches of skin. It often involves hands, wrists, and armpits, areas around eyes and lips, and genital skin. Although vitiligo only affects about 1 percent of the population, all races are affected and it can cause disfigurement, especially in
1750 Vitiligo blacks. It may cause social stigmatization and isolation in severe causes, and may lead to psychological trauma. There are some theories about the cause, but no definite etiology has been determined. CAUSES The most likely cause is autoimmune, where the body’s own immune system attacks the melanocytes. This type of vitiligo may be associated with other autoimmune diseases such as pernicious anemia (immune system attacks stomach cells resulting in deficient absorption of vitamin B12, leading to anemia), Addison’s disease (immune system attacks the adrenal glands), and thyroiditis (immune system attacks thyroid gland). Another theory is that chemical injury leads to depigmentation. Breakdown products of excess neurotransmitters generate free radicals and hydrogen peroxide. These chemicals are toxic to melanocytes and destroy them. Additional theories are stress and heredity (20 to 30 percent of patients have a relative with vitiligo). TREATMENT Treatment of vitiligo can be managed pharmacologically with traditional and herbal medicine as well as surgically, and cosmetically. Treatment can further be divided into repigmentation therapy and depigmentation therapy. Repigmentation therapy includes surgery, and medications such as steroids, calcineurin inhibitors, PUVA, NBUVB, and some herbal remedies. Depigmentation therapy includes topical use of medication (hydroquinone or monobenzone). This does not stop the disease process, but the depigmentation of unaffected skin may give it a more even appearance. A side effect is local skin irritation. One traditional treatment approach is the use of topical steroids. These repigment the skin, but side effects include thinning of the skin where they are applied. Another treatment is using calcinurin inhibitors such as tacrolimus and pimecrolimus. These repigment the skin like steroids but do not cause skin thinning. However, these products have been linked to lymphoma and skin cancer. Other repigmentation therapies include using ultraviolet light. For example, UVA light with psoralen (a UV light sensitizer) and narrow band UVB light are used to repigment the skin. A side effect is very tan skin.
Some herbal remedies have been used to repigment the skin as well. Experimentation with many of the herbs listed have increased melanocyte migration and growth in labs only and may show promise in helping those with vitiligo, but they have not been proven in scientific studies. The following herbs may eventually show promise in repigmentation: Gingko (Ginkgo Biloba), Radix Salviae Miltiorrhizae (Danshen), Semen Cuscutae (Cuscuta chinensis Lam), Flos Carthami (Safflower), Fructus Tribuli (Tribulus Fruit), Radix Astragali (Astragalus Root), Fructus Psoraleae (Fruit of Psoralea), Fructus Ligustri Lucidi (Ligustrum seed), Radix Angelicae Dahuricae (Dahurian angelica root), and Piper Nigrum Fruit (Black pepper extract). Surgery is another treatment option for people with vitiligo. There are three possibilities: (1) using pigmented skin from one area of the body and attaching it to the depigmented area (autologous skin grafting), (2) obtaining melanocytes from a pigmented area, growing more of them in a lab, and then transplanting them onto the depigmented area (autologous melanocyte transplant), (3) tattooing the depigmented area with skin-colored ink. A variety of make-ups designed to conceal the depigmented area are also available, and are extremely helpful when vitiligo is present in a highly visible area, such as the face or hands. SEE ALSO: Autoimmune Diseases (General); Skin Diseases
(General); Skin Pigmentation Disorders.
Bilbiography. Beth Goldstein and Adam Goldstein,
Vitiligo, www.uptodate.com (cited October 2006); Vinay Kumar, et. al, Robbins and Cotran Pathologic Basis of Disease, 7th ed. (Elsevier, 2005); Z. Lin, et al., “Stimulation of Mouse Melanocyte Proliferation by Piper Nigrum Fruit Extract and its Main Alkaloid, Piperine,” Planta Med (v.65/7, 1999); K. H. Mou, et al., “Promoting of Melanocyte Adhesion and Migration by Malytea Scurfpea Fruit In Vitro,” Meth Find Exp Clin Pharmacol (v.26, 2004); X. Zhang, et al., “Effects of Single Herbal Drugs on Adhesion And Migration of Melanocytes,” Journal of Traditional Chinese Medicine (v.25/3, 2005). Gautam J. Desai, D.O. Regan Barnes, MS III Kansas City University of Medicine and Biosciences College of Osteopathic Medicine
Voice Disorders Voice is one of the most important elements of human communication. It is the means by which we verbally express ourselves. Social interactions rely heavily on spoken messages between communication partners for the exchange of ideas. When an individual has problems with voice production, communication is adversely affected. Voice Production Voice is produced by the cyclical vibrations of the vocal folds within the larynx. The vocal folds at rest are apart to allow breathing. During speech production, they approximate, relax, and repeat to produce a vibration pattern. This pattern is measured in cycles per second and represents an individual’s fundamental frequency, or the frequency band of their speaking voice. Males typically have a fundamental frequency around 150 cycles per second, and females around 250 cycles per second. The fundamental frequency changes when a person has, or acquires, a voice disorder. Voice disorders are categorized by various voice qualities associated with difficulties in voice production at the level of the larynx. There is either a problem with the vocal folds being able to sufficiently approximate or relax during the vibration cycle. Both aspects of the cycle are critical to appropriate voice production, function, and quality. Etiology There are several categories of voice disorders, each representing a type of dysfunction of the vocal mechanism. The main categories are breathy, harsh, and hoarse. A breathy voice is the by-product of an air leakage during the approximation phase of the vibratory cycle. This leakage causes noise and a weak sounding voice. There are many things that could prevent complete vocal fold approximation, such as vocal nodules, edema, vocal fold paralysis, physical asymmetry, infection, or contact ulcers. In some cases, the dysfunction may originate from the neural level, subsequently causing laryngeal dysfunction, as in the case of stroke and other brain lesions. A harsh voice is similar in physiology to a breathy voice but the periodicity of vocal fold vibration is much lower. One or both vocal folds are not able to
Voice Disorders
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vibrate at their optimal speed, creating a noisy lowpitched voice. Vibration is also aperiodic, creating random acoustic patterns in the voice. Some common causes attributing to harsh voice are smoking, alcohol use, and vocal abuse such as yelling. Yelling causes increased friction between the vocal folds and can lead to vocal pathologies such as vocal nodules, contact ulcers, and polyps. A hoarse voice is one that presents elements of both the breathy and harsh voices. A hoarse voice has a periodicity that is so low that you can often hear each separate vibration cycle. People who have a hoarse voice often avoid speaking altogether because of associated pain, vocal fold damage, and social judgment. Acute laryngitis is a common cause of a hoarse voice, where the vocal folds are swollen, thick, heavy, and unable to vibrate efficiently. Chronic exposure to smoke, pollution, and other carcinogens can produce lesions on the vocal folds, which may render them paralyzed. Treatment Individuals experiencing a degradation in voice quality should see an otolaryngologist for a physical evaluation. Often, a hoarse voice is a symptom of a more serious pathology, such as laryngeal cancer. In this case, a laryngectomy may be necessary, and normal speech production permanently lost. Assistive speech devices and alternative speech strategies are options for laryngectomy patients, but can be upsetting to communication partners and affect both communication and social interactions. Some cases of disordered voice are temporary and clear up with the passing of an illness. Others are treatable with surgery or speech therapy. A speech therapist may be able to coach a client on strategies to use when speaking that will eliminate or reduce the disordered effect. If one vocal fold remains tense, causing a strained voice, the client may be instructed to turn their head slightly to one side to shorten the tense fold and lengthen its pair. Although this strategy may not correct the physical asymmetry behind the voice disorder, it does serve to reduce or minimize the adverse vocal quality. Prevention Some individuals are born with physical asymmetry of the vocal mechanism, preventing normal voice
1752 Voluntary Euthanasia Society (VES) production. However, for most of us, voice disorders are preventable by practicing good health measures in our everyday lives. The most prevalent cause of voice disorders is vocal abuse and misuse. Vocal abuse includes lifestyle choices such as smoking and drinking alcohol, excessive talking, throat clearing, coughing, inhaling irritants or pollutants, screaming, and yelling. Vocal misuse involves speaking too loudly or persistent use of pitch that is too low or too high. Smoking can lead to cancer and paralysis of one or both vocal folds. The raspy and rough voice of a smoker is the sign of vocal abuse and the onset of a voice disorder that was preventable. Singers are also at risk for voice disorders. Many voice coaches advise their students on proper vocal maintenance and hygiene, but it is not rare for a singer to lose his or her voice due to the abuse endured during a long tour or from poor voice practices. Many of the ailments of singers are temporary and alleviated with rest, but singers are sometimes forced to retire their careers because of vocal pathologies created by constant high-intensity friction on the vocal folds. Other high-risk professions include auctioneer, teacher, sports coach, clergy, lawyer, and construction foreman. SEE ALSO: Otolaryngologist; Otolaryngology; Speech and
Communication Disorders.
Bilbiography. “Disorders of Vocal Abuse and Misuse,”
www.nidcd.nih.gov/health/voice/vocalabuse.asp (cited April 20, 2006); “Fact Sheet: Nodules, Polyps, and Cysts,” www. entnet.org/healthinfo/throat/vocal-cord-lesions.cfm (cited April 2006); Willard R. Zemlin, Speech and Hearing Science: Anatomy and Physiology, 4th ed. (Prentice Hall, 1998). Laura Chute Independent Scholar
Voluntary Euthanasia Society (VES) The Voluntary Euthanasia Society (VES) was formed in the United Kingdom in 1935 by a group of clergy, physicians and lawyers who believed in an adult
patient’s right to choice near the end of his or her life and the right to die with dignity. Independent of any religious group or governmental agency, the organization, which officially changed its name to Dignity in Dying in 2005, advocates for legal medically assisted dying under tight guidelines and with the patient in charge of pain relief and medical care; more open discussion about dying; and more quality support for medical personnel who must deal with end-of-life issues. VES educates medical personnel, government officials, and the general public on a person’s rights near the end of life. To that end, they supply living wills, a document that allows a person to state what degree of treatment he or she desires when too seriously ill to communicate with healthcare personnel. Choices include asking for life-prolonging treatment or to refuse such treatment. VES lobbies Parliament to change the current laws, working with a Parliament member to draft the Assisted Dying for the Terminally Ill bill. The group states several objections to the current law, including that it is uncertain and arbitrary. The Suicide Act 1961 states that anyone assisting another with suicide has committed a crime punishable by 14 years in prison; in reality, in 15 percent of these cases, no charges are filed. Furthermore, the law is not preventing doctors or family members from performing euthanasia or “mercy killings.” VES cites surveys showing that doctors perform nearly 3,000 cases of euthanasia annually, while a 2004 poll revealed that 47 percent of people stated a willingness to assist with a loved one’s suicide. The group points out that some terminally ill patients commit suicide before they are unable to do so without help; changing the law, VES believes, will allow these people to live a longer life. Moreover, some UK citizens are traveling to Switzerland, where a group called Dignitas is assisting them with their dying. According to some reports, Dignitas is not limiting this practice to those terminally ill; VES believes that a tightly controlled assisted dying law in the United Kingdom is a better and more humane choice. Finally, VES cites a 1996 British Social Attitude Survey wherein 82 percent of those surveyed said that people suffering from terminal illness should have the right to ask their doctors for assistance in dying.
Vulvar Cancer
VES provides speakers on a donation basis, and they publish a significant number of reports on end-of-life issues. Copies of most of these reports can be downloaded from their Web site (www.dignityindying.org.uk). In 1980, VES members in Scotland broke off from the British organization and formed an independent VES association. There are also other VES groups around the world, including the South Australian Voluntary Euthanasia Society (SAVES) and the Voluntary Euthanasia Society of Queensland, Inc. (VESQ), formed in 1987, among others. SEE ALSO: Death and Dying; Suicide. Bilbiography. “New Pro-Euthanasia Group Name Row,”
BBC News (January 23, 2006), www.news.bbc.co.uk/1/hi/ health/4638766.stm (cited June 2007); Voluntary Euthanasia Society (VES), www.dignityindying.org.uk. Kelly Boyer Sagert Independent Scholar James S. Yeh Boston University
Vulvar Cancer While cancer of the vulva is not one of the most common cancers of the female genital tract, the incidence of in situ vulvar carcinoma has more than doubled over the past 20 years. This, coupled with newer, less radical surgical treatments make it an important part of the reproductive health picture for women globally. Cancer of the vulva represents approximately 5 percent of all gynecologic cancers, afflicting nearly 4,000 new women each year and claiming 1,000 lives in the United States alone. Applying similar incidence rates to worldwide populations indicates a large number of women live with this illness in developing countries as well, but this remains less well documented. This type of cancer is seen in two populations of women, those in their 70s and younger women less than 40 to 50 years of age. It is in younger women that the biggest increases in incidence have been seen and
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it is thought that these cases are related to human papillomavirus (HPV) infection. HPV is the virus that causes cervical cancer. These HPV-related lesions of the vulva tend to be slow growing and have a long preinvasive period during which they can be detected and treated before invasive carcinoma develops. Older women tend to have the non-HPV–related lesions and the etiology for these lesions is unknown. While the most common symptom is an itching sensation in the vulva, women also complain of burning, bleeding, or pain in the area. Under a physician’s exam, a visible lesion is often present and should be biopsied. Once a biopsy has revealed cancer with some indication of the depth of invasion of the lesion, a treatment plan is created. Years ago, the treatment for vulvar cancer was a massive surgical resection of the groin. Although successful, this procedure often left women feeling badly disfigured, depressed, sexually disrupted, and with long-term problems of swelling and difficult wound healing. Today, there are better surgical options that are appropriate for most patients. Studies show that it is possible to achieve good survival rates by surgically removing the area of the lesion(s) and a separate incision(s) in the groin to remove lymph nodes that may also harbor cancerous cells. The location of the lesion and depth of invasion indicate whether the lymph node dissection needs to be done only on one side of the groin or both sides. Alternatively, if only unilateral groin lymph node dissection was indicated before surgery but early pathology results indicate positive nodes, then the lymph nodes on the other side of the groin will also need to be removed. Women with positive lymph nodes or more advanced disease will need postoperative radiation to the groin and pelvis. Some women with inoperable lesions may require chemotherapy as well as radiation. With these treatments, vulvar cancer is a largely curable condition. In 85 to 90 percent of cases, these techniques will result in control of the disease and no recurrence. For those women who do have recurrences, nearly half will be in the vulva and need to be assessed for treatment. Five-year survival rates for vulvar cancer vary with the initial size of the tumor. Women who came to their physicians with relatively small lesions less than 2 cm in diameter have nearly 90 percent survival five
1754 Vulvar Cancer years later. Even women with less than 2-cm lesions and positive lymph nodes have five-year survival rates of nearly 80 percent. Women with primary lesions greater than 4 cm and positive lymph nodes have 45 percent survival at five years. A diagnosis of vulvar cancer is by no means a death sentence. Vulvar lesions are highly treatable so long as they are seen and diagnosed early by a physician. Regular gynecologic exams are an important part of reproductive health and should not be skipped. Women who smoke and/or have already tested positive for HPV from a previous Pap smear should be extra vigilant about their gynecologic care.
SEE ALSO: Cervical Cancer; Gynecologist; Gynecology; Ob-
stetrician/Gynecologist; Vaginal Cancer; Vaginal Diseases.
Bilbiography. R. DeBernardo, et al., “Vulvar and Vagi-
nal Cancers,” The Johns Hopkins Manual of Gynecology and Obstetrics, 2nd ed. (Lippincott, Williams, & Wilkins, 2002); N.F. Hacker, “Vulvar Cancer,” Practical Gynecologic Oncology, 4th ed. (Lippincott, Williams, & Wilkins, 2005); F.B. Stehman and K.Y. Look, “Carcinoma of the Vulva,” Obstetrics & Gynecology (v.107/3, 2006). Megan K. Guffey, M.D., M.P.H. Independent Scholar
W Warshaw, Joseph (1936–2003) Joseph Warshaw was a American pediatrician who investigated the growth of human organs in fetuses using biochemical, cell biological, and molecular techniques. Throughout his career, Warshaw was a staunch supporter of education for pediatric scientists and was responsible for launching new academic programs and raising funds for medical research. He is unanimously considered a leading figure in pediatrics for his contributions to the understanding of how organs mature during pregnancies. Warshaw was born in Miami, Florida, in 1936. He earned a bachelor’s degree in biology at the University of Florida. He then went on to Duke University where he received his medical degree. He served his residency in pediatrics at Duke and the University of Rochester. Warshaw held faculty positions at prestigious institutions such as Harvard Medical School and Massachusetts General Hospital from 1967 to 1973; the University of Texas Southwestern Medical Center in Dallas, where he was hired as a professor and chair of pediatrics between 1982 and 1987; the Children’s Hospital at Yale-New Haven, where he was Physician-in-Chief; and Yale University School of Medicine, where he served as Professor and Chairman of Pediatrics and Deputy Dean for Clinical Af-
fairs. Warshaw worked at Yale from 1973 to 1982 and from 1987 to 2000. After he left Yale, he became Dean of the University of Vermont College of Medicine, a position he retained until his death. Since his early career at Harvard, Warshaw developed a particular interest in the care of newborns and in the area of developmental metabolism. His extensive research in these fields are summarized in more than 100 papers and several book-length studies. Warshaw served on many editorial boards of academic journals, including Pediatrics and Pediatric Research, and he coedited Oski’s Principles and Practice of Pediatrics. Because of the prominent positions he held as university administrator in various institutions, Warshaw’s career was equally divided between scientific research and academic organization. He always encouraged medical students to apply scientific discoveries to daily patient care. While dean at the University of Vermont, he gave a fundamental contribution to the launching of the university’s new medical curriculum in 35 years, which combines basic and clinical sciences with notions of leadership and team building. While at UMV, Warshaw also helped to devise the joint M.D./Ph.D. program and to attract more funds for university research, focusing in particular on areas such as
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1756 Watson, James cancer, cardiovascular disease, neuroscience, and lung biology. In addition to holding prestigious positions at American universities, Warshaw was also a Josiah Macy Faculty Scholar at the University of Oxford. Throughout his career, he served on medical societies, committees, and boards of trustees. Warshaw was a member of the American Society for Clinical Investigation, the Association of American Physicians, the Society for Pediatric Research becoming its president in 1982, the American Pediatric Society, the American Society for Biologic Chemists, the American Society for Cell Biology, the Eastern Society for Pediatric Research, and the Institute of Medicine of the National Academy of Science. Warshaw founded and served on the Steering and Selection Committees for the Pediatrician/Scientist Training Program and took part in the Advisory Council of the National Institute of Child Health and Human Development of the National Institutes of Health. He chaired the board of trustees of the International Pediatric Research Foundation and lent his expertise to many external review committees, including the Scientific Advisory Board of St. Jude’s Children’s Research Hospital, Toronto Children’s Hospital Research Institute, and the Children’s Hospital of Cincinnati. Warshaw died on December 29, 2003, in Burlington, Vermont, after a long battle against multiple myeloma. SEE ALSO: Child Development; Pediatrics. BIBLIOGRAPHY: Julia A. McMillan, ed., Frank A. Oski, Ralph
D. Feigin, Joseph B. Warshaw, and Catherine D. DeAngelis, Oski’s Pediatrics: Principles and Practice (Lippincott Williams & Wilkins 1999); “Pediatrician Joseph Warshaw, an Expert on Neonatal Care,” Yale Bulletin and Calendar, www. yale.edu/opa/v32.n17/story14.html (cited June 2007).
Luca Prono Independent Scholar
Watson, James (1928– ) American scientist who shared the 1962 Nobel Prize in Physiology or Medicine with Francis Crick and Maurice Wilkins for their discovery of the structure
of DNA. Watson helped Crick and Wilkins to determine the molecular structure of nucleic acids, thus advancing the understanding of how genetic information is passed on. Starting with the attribution of the Nobel Prize, Watson’s career has never eschewed controversy and the scientist’s problematic views on genetically modified food, homosexuality, and genetic engineering have received wide press coverage. Watson was born on April 6, 1928, in Chicago. Due to his precocity as a student, he gained entrance to the University of Chicago at 15 and obtained his B.Sc. in zoology in 1947. His Ph.D. application was turned down by both Harvard and the California Institute of Technology, institutions where Watson would teach later in his life. Watson was accepted by Indiana University where he worked on a Ph.D. in genetics and came into contact with important figures in the field such as Salvador Luria and Max Delbrück. Through them, Watson came into contact with the so-called Phage Group, which challenged the conventional notions of DNA. After graduating with a Ph.D. in zoology in 1950, Watson went to Europe for his postdoctoral research, first to Denmark and then to England. In 1951, Watson started working with Francis Crick at the Cavendish Laboratory of the University of Cambridge, a collaboration which eventually led to the discovery of the helical structure of DNA only a year and a half later. Using the x-ray crystallography experiments of Rosalind Franklin and Maurice Wilkins which had been carried out at King’s College, Watson and Crick published their results on DNA structure in the April 25, 1953, issue of Nature. The model of the DNA as a double helix revolutionized research in the emerging fields of molecular genetics and biochemistry. It also sparked controversy as Watson and Crick used data obtained from another laboratory. Watson returned to the United States where he obtained a teaching position at Harvard and set out to write The Double Helix, his personal account of the DNA discovery. Dropped by Harvard University Press for its frank and, at times, brash descriptions of colleagues and controversies, the book was published in 1968 by a commercial press. That same year, Watson was appointed Director of the Cold Spring Harbor Laboratory (CSHL), where he proved his fund-raising skills and became a vocal advocate for freedom of scientific research. Thanks to his direc-
West Nile Virus
torship, the CSHL turned out to be one of the leading centers in molecular biology. Watson’s impressive record as a scientific researcher and his success as an administrator led to his appointment as Head of the Human Genome Project at the National Institutes of Health (NIH) in 1988. He resigned from this position after four years due to disagreements with the newly appointed NIH director, Bernadine Healy. In 1994, he also resigned from Director of the Cold Spring Harbor Laboratory, remaining its president for other 10 years and then assuming the title of Chancellor. In addition to The Double Helix, Watson has produced several important textbooks which enjoyed wide use, including Molecular Biology of the Gene, Molecular Biology of the Cell, and Recombinant DNA. He has also written books published by commercial presses such as Random House, where he has taken several controversial stances. In DNA: The Secret of Life, for example, he has explicitly argued in favor of genetically modified crops, praising their potential benefits and challenging their critics. In public lectures and interviews, he has supported genetic screening claiming that stupidity is comparable to a disease that should be treated with biotechnology. SEE ALSO: DNA; Genetics; Genotype. BIBLIOGRAPHY: James Watson, DNA: The Secret of Life
(Random House, 2003); James Watson, The Double Helix: A Personal Account of the Discovery of the Structure of DNA (Atheneum, 1968); James Watson, Genes, Girls, and Gamow: After the Double Helix (Random House, 2002). Luca Prono Independent Scholar
West Nile Virus First isolated in Uganda in 1937, the West Nile Virus was characterized in Egypt in the 1950s. The flavivirus containing RNA first appeared in the United States in 1999 in New York City. The prevalence of the disease has spread across the United States. Epidemiologists noted a westward trend for spreading
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across the country and by the summer of 2006 the virus had been reported in 48 states. Monitoring by public health departments included trapping of mosquitoes to determine the size of the mosquito population and classifying the mosquitoes to find West Nile Virus carriers. The also studied sentinel chicken flocks as a predictor for the emergence of the virus, and tested birds for presence of the virus. The practice of setting up and testing sentinel chicken flock was not always a good predictor of the virus’ presence. West Nile Virus is spread by vector transmission where a living organism passes the virus to the human. The pathogen or cause of disease spends part of its lifecycle in the vector and then completes the rest within the human. The most common vector for West Nile Virus is the Culex tarsalis mosquito. In addition to contracting West Nile Virus through the bite of a mosquito carrier, transmission through blood transfusion also may occur. After 23 transfusion-related infections were reported in the United States in 2002, blood banks around the country began to test potential blood donors for West Nile Virus during warm weather. In 2003, Colorado’s state health department declared an end to the West Nile Transmission season on October 1. Thirteen days later, Bonfils Blood Center in Colorado received a positive test revealing the presence of viral genes for West Nile Virus in one donor’s blood. This indicated the virus stays in the blood longer than previously believed. People will develop West Nile symptoms within 314 days of being bitten by an infected mosquito. Symptoms include fever, extreme fatigue, headache, body aches, and occasionally a skin rash and swollen lymph nodes; the illness is similar to a bad case of influenza. Physicians who saw patients with these symptoms advised them to drink plenty of fluids and rest. If the virus leaves the blood stream and enters the nervous system, a severe form of the illness develops. Meningoencephalitis is an inflammation of the brain and membrane that envelops the brain and spinal cord. Some infected with West Nile Encephalitis have reported continued problems with movement and parasthesia in the limbs for months following the illness. Specific antiviral therapy is not available for the treatment of West Nile Virus nor is a vaccine approved for use in humans, though veterinarians do have a vaccine for use in horses.
1758 Western Sahara In 2005, The National Institute for Allergy and Infectious Diseases began an experimental trial of a gene-based vaccine that doesn’t carry live virus; it is composed of a plasmid, a circular piece of DNA. Multiple copies of the plasmid are injected into the muscle with a high-pressure needleless gun, which has been found more effective than traditional needle injection. Inside the muscle, the body uses the DNA to create the two proteins. The proteins are then released into the bloodstream and the immune system creates antibodies to the proteins to fight the infection. As part of the testing of the vaccine, horses received the vaccine and were later exposed to the virus. The horses did not come down with the West Nile Encephalitis. Prevention is currently the best protection against West Nile Virus. Methods of prevention for contracting West Nile Virus include using an insect repellant containing DEET, Picariden or oil of lemon eucalyptus; dressing in long sleeves and pants, avoiding the outdoors during the period from dusk to dawn, and draining standing water in ponds, birdbaths and pools to reduce the breeding areas for mosquitoes. Insecticide in two forms can be used to kill mosquito populations; a larvicide in special form for use in standing water can be placed in the standing water to kill mosquito eggs and adulticide can be sprayed to kill adult mosquitoes. The West Nile Virus has been reported in countries around the world in Europe, Africa and Asia with reports of animal, avian and human illness. The prevalence of West Nile Virus in humans may be related to the weather, an especially wet mosquito season provides increased breeding areas for mosquitoes. Vigilance in controlling the mosquito population through use of insecticide and in the use of insect repellants helps prevent contracting the virus. See Also: Centers for Disease Control and Prevention
(CDC); Meningitis; Mosquito Bites; Viral Infections.
BIBLIOGRAPHY: Jim Erickson, “Virus lurks in the Blood
for Weeks” Rocky Mountain News (November 29, 2003); Ben Harder, “Seeking Immunity” Popular Mechanics (September 2006); “NIAID Begins Clinical Trial of West Nile Virus Vaccine” (NIH, April 18, 2005); Samuel Shelburne III, MD and Wayne X. Shandera, MD, “Infectious
Diseases: Viral and Rickettsial”, Current Medical Diagnosis and Treatment (Lange Medical Books, 2004); “West Nile Virus Activity: United States, January 1–July 18, 2006” MMWR (July 21, 2006). Lyn Michaud Independent Scholar
Western Sahara Located on the North Atlantic Ocean, Western Sahara has a history of war and uncertainty. Since the status of the country is so ambiguous, there is virtually no data available on the health of the 273,008 people who live in this north African nation. Reliable information on even basic indicators such as per capita income and mortality rates are not accessible. It is believed that the standard of living is well below that of Morocco, which the United Nations Development Programme (UNDP) Human Development Reports rank 123rd in the world on general quality-of-life issues. Some social programs have been instituted to promote the well-being of the Saharawi people. For instance, the Promotion Nationale supplements the incomes of the poorest families. Child labor is not common in Western Sahara, but many children join other family members in shepherding. Even though a minimum wage is in place, it is often ignored. Some workers are forced to labor in fish processing plants six days a week for up to 12 hours a day, earning only subsistence wages. Workers do have basic occupation and safety protections. In the mid- to late 1970s, Morocco annexed twothirds of the northern section of Western Sahara, and tensions escalated until guerilla warfare broke out. In 1991, the United Nations brokered a tenuous ceasefire. The lack of a peaceful solution to the conflict is chiefly due to an unwillingness on the part of Morocco and the pro-independence Polisario Front of Western Sahara to settle the question of whether the Saharawi have the right of suffrage. American attempts to mediate the dispute have been rebuffed. As political and civil unrest continues, the health of the Saharawi has suffered as economic and social conditions continue to deteriorate. Accusations of human rights abuses, particularly among political
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eral population, is a result of heavy inbreeding. Those who suffer from celiac disease are unable to digest the gluten present in wheat, rye, and barley, all of which are staples in the Saharawi diet. Side effects of the disease include bronchitis, loss of appetite, fever, vomiting, and abdominal pain and distension. SEE ALSO: Disease and Poverty; Morocco. BIBLIOGRAPHY: Central Intelligence Agency, “Western Sa-
Desert lands: Like many other poor African nations, Western Sahara suffers from a number of easily preventable diseases.
prisoners, continue to surface, and violence has become an everyday occurrence. The desert climate of Western Sahara is hot, and the health of the population is threatened by dust and sand-filled sirocco winds in the spring and winter and by the harmattan-induced haze that is present for 60 percent of the year. Despite a coastline of 1,110 km, there is a grave shortage of fresh water available. Half the population is involved in the agricultural sectors, and most farming is done at the subsistence level. However, only 0.2 percent of all land area is arable, and most food is imported. Fishing is important to the economy, as is phosphate mining. Morocco is currently exploring the Western Saharan coast for oil. Like many other poor African nations, Western Sahara suffers from a number of easily preventable diseases. The population has an intermediate risk of contracting food and waterborne diseases such as bacterial and protozoal diarrhea, hepatitis A, and typhoid fever. From April to November, waterborne diseases pose a threat in certain areas. Locusts, amounting to near plague status, have been sighted in the southern area of Western Sahara. High incidences of celiac disease have been found among the thousands of Saharawi people who have migrated to Algerian refugee camps. Geneticists believe the disease, which is from five to ten times more common among the Saharawi than among the gen-
hara,” www.cia.gov/cia/publications/factbook/geos/wi.html (cited June 2007); Erik Jensen, Western Sahara: Anatomy of a Stalemate (Lynne Rienner, 2005); New Internationalist, “Western Sahara,” www.newint.org/columns/country/2004/12/01/western-sahara/ (cited June 2007); Akbarali Thobhani, Western Sahara since 1975 under Moroccan Administration: Social, Economic, and Political Transformation (Edwin Mellen, 2002); World Bank, Changing the Future: Choosing Prosperity for the Middle East and North Africa (World Bank, 1995); World Health Organization, Bulletin (June 2001). Elizabeth R. Purdy, Ph.D. Independent Scholar
Whooping Cough Pertussis, commonly referred to as whooping cough, was first identified in 1578 by French physician Guillaume Baillou who described the disease, which affected mostly children, as an irritation of the lungs in which patients experienced high fevers, swelling, fatigue, vomiting, and upset stomachs. The disease was characterized by a “whooping” cough, and death often resulted from hemorrhages or asphyxiations brought on by excessive coughing or from the pneumonia and bronchitis that often accompanied the disease. Symptoms were generally less severe in adults. Doctors had little understanding of the disease, and it was resistant to all known medications. Folklore methods, such as taking a patient to a high hill where the air was clear or administering powdered mice in milk or white ants brewed in tea, also proved useless. In the 17th century, British physician Thomas Sydenham named the disease pertussis, meaning
1760 Whooping Cough “severe cough” in Latin. By the early 20th century, scientists had isolated the bacterium that caused whooping cough and learned that it is spread through coughing, sneezing, or mucus. England lost more than 120,000 people to pertussis between 1588 and 1865, and around 84,000 Prussians died from the disease between 1875 and 1880. One of the worst epidemics on record occurred in Scandinavia over a 15-year period in the 18th century when approximately 3,000 lives were lost each year. By the turn of the 20th century, whooping cough epidemics were still ravaging populations around the world, frequently claiming the lives of all children within a family. The United States experienced epidemics in the 1920s and 1930s, and it was estimated that 73 percent of all American children had contracted the disease by the age of 10. The first pertussis vaccine was developed in 1912 by Belgian scientists Jules Bordet and Octave Gengou. After several refinements to the vaccine, the first completely successful vaccine was developed by American scientists Pearl Kendrick and Grace Eldering in 1938. Improved sanitation, nutrition, housing, and healthcare also helped to cut down on the spread of the disease. During World War II, the introduction of antibiotics, allowing pneumonia and bronchitis to be treated, led to a substantial drop in fatalities associated with whooping cough. The pertussis vaccination, which is given in conjunction with vaccinations against diphtheria and tetanus (DPT), has proved to be extremely controversial. After taking the vaccines, many infants run fevers up to 103 degrees Fahrenheit and experience a period of lethargy and heavy sleeping. Other postvaccine symptoms include high-pitched screaming, an inability to be comforted, and loss of consciousness. A minority of infants develop medication-resistant convulsions, mental retardation, learning disabilities, hyperactivity, or physical handicaps. Some children die from pertussis-related complications, and a number of researchers have linked the vaccine to the onset of sudden infant death syndrome (SIDS). Parents are advised to discuss with their pediatricians the possibility that pertussis be removed from the DPT regimen for infants who have suffered negative reactions. The nonprofit organization, Dissatisfied Parents Together, based in Vienna, Virginia, provides information for parents who wish to know more about the vaccine.
Critics of the pertussis vaccination claim that drug companies in some countries place desire for profit over the health of children. The medical profession has also earned a share of the criticism for not doing an adequate job of educating parents about possible side effects of the vaccines that are given at two, four, and six months, supplemented by two additional shots. In the United States, the vaccine is required for entry into school, and 96 percent of all children receive the vaccine. Japan has developed an alternate vaccine that is considered safer, and some nations in western Europe have removed pertussis from the list of required vaccines. Whooping cough is generally believed to have been eradicated in the industrialized world by the latter 20th century. However, the Centers for Disease Control and Prevention (CDC) report that 5,000 to 7,000 cases are still reported in the United States each year. They note that the incidence of cases has been steadily rising since the 1980s. Pertussis is most common in developing countries. In 1996, a whooping cough epidemic broke out in Basra, Iraq. Approximately 133 cases were identified. Most victims were females who had been immunized. The United Nations Children’s Fund (UNICEF) reported in 2005 that whooping cough and measles were the major causes of death among Afghani children. Global health experts have expressed grave concern that children in sub-Saharan Africa, the poorest and most vulnerable section on Earth, are not receiving the necessary DPT vaccinations. It is estimated that 26,000 infants around the world are never immunized against diphtheria, pertussis, and tetanus. See Also: Immunization/Vaccination; Respiratory Dis-
eases (General); Sudden Infant Death Syndrome (SIDS).
BIBLIOGRAPHY: R. E. Behrman, et al., Nelson Textbook of
Pediatrics (Saunders, 2000); Centers for Disease Control and Prevention, “Health, United States 2005,” www.cdc. gov/nchs/data/hus/hus05.pdf (cited June 2007); Centers for Disease Control and Prevention, “Pertussis,” www. cdc.gov/ncidod/dbmd/diseaseinfo/pertussis_t.htm (cited June 2007); Harris L. Coulter and Barbara Loe Fisher, A Shot in the Dark (Harcourt, Brace, Jovanovich, 1985); Ralph H. Henderson, “Immunization: Going the Extra Mile,” www.unicef.org/pon98/health1.htm (cited June 2007); United Nations Children’s Fund, “Brutally Cold
Wilson’s Disease
Weather and Whooping Cough Threaten Children,” www. unicef.org/infobycountry/afghanistan_25164.html? (cited June 2007); World Health Organization, “GIVS Global Immunization Vision and Strategy,” www.who.int/vaccines-documents/DocsPDF05/GIVS_Final_EN.pdf (cited June 2007). Elizabeth R. Purdy, Ph.D. Independent Scholar
Wilkins, Lawson (1894–1963) Lawson Wilkins was the American founder of pediatric endocrinology, often dubbed as the veritable father of the discipline, who focused in particular on problems related to genetics and growth. Wilkins was born on March 6, 1894, in Baltimore, Maryland. His father was a general practitioner. Wilkins enrolled at Johns Hopkins before World War I but had to interrupt his studies to serve in the American Expeditionary Force in France after the American entry into war in 1917. He graduated from Johns Hopkins Medical School in 1918 and joined its medical staff two years later. Wilkins trained as a pediatrician at Yale’s New Heaven Hospital and at the Harriet Lane Home. Although he started a private practice as a pediatrician in Baltimore, he remained in contact with his colleagues at Johns Hopkins Hospital. He became Assistant Professor of Pediatrics in 1928 and seven years later was appointed Director of the Endocrine Clinic where he began to investigate the influence of the endocrine organs to growth. Wilkins progressed to Associate Professor in 1942 and four years later, he gave up his private practice to pursue his academic career full time. He remained director of the clinic until 1954, when he became Acting Pediatric in Chief at the Harriet Lane Home. In 1957, Wilkins became Professor of Pediatrics at Johns Hopkins Medical School and two years later, he was appointed Emeritus Professor. He died on September 28, 1963. Wilkins carried out important research on the metabolic growth and developmental aspects of endocrine disorders in children. During the 1950s, Wilkins attracted great interest with his work on anomalous sex characteristics caused by congenital enlargement and overactivity of the adrenal glands. Wilkins suggested
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that the activity of these glands could be reduced through small doses of cortisone. Building upon his research, Wilkins published Diagnosis and Treatment of Endocrine Disorders in Childhood and Adolescence, which soon became a standard textbook for students in the fields and received international praise. Wilkins won several important prizes including the John Howland Award from the American Pediatric Association, the Koch Award from the American Endocrine Society, and the Borden Award of the American Academy of Pediatrics. Wilkins was also the president of the Endocrine Society and of the American Pediatric Society. SEE ALSO: Endocrine Diseases (General); Endocrinology;
Metabolic Disorders; Pediatrics.
BIBLIOGRAPHY: H. R. Wiedemann, “Lawson Wilkins,”
European Journal of Pediatrics (v.151/10, 1992); Lawson Wilkins, Diagnosis and Treatment of Endocrine Disorders in Childhood and Adolescence (Charles C Thomas Publisher, Limited 1966). Luca Prono Independent Scholar
Wilson’s Disease Wilson’s Disease (WD) is a genetically inherited disorder that affects the way the human body metabolizes copper. Copper is essential to body metabolism and when there is too much or too little, problems arise. Wilson’s Disease disables the body’s ability to properly dispose of copper and accumulation begins to cause damage to internal organs. Globally it is understood that one in 30,000 individuals actively have the disease and that it is most common in communities where consanguineous marriage (mating between blood relatives) is common. In the developing world many issues can arise from late or no diagnosis and complete lack of definitive treatment. If left untreated Wilson’s Disease is fatal. Dr. Samuel Wilson first described the disease in a scientific paper in 1912 and treatment began in the 1950’s. The accumulation of copper begins at birth. Copper should be excreted by the liver and with WD it is retained and accumulates. The accumulated copper
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Wilson’s Disease
causes damage and inflammation or hepatitis develops. If left untreated, the liver becomes so damaged that copper will enter the bloodstream and cause damage to other organs including the kidneys, eyes, bone and the brain and eventual death. Major symptoms generally develop during adolescence. Genetic Disorder WD is an autosomal recessive (not sex-linked) disease and can occur equally in men and women. The gene that carries WD is passed down to the offspring by both parents. Two abnormal genes are required to have the disease. If one child has only one gene from one parent, they will not show signs of the disease. WD affects all races and no nationalities or regions are immune. The related gene is located on chromosome 13 and linked to copper transport ATP7B. Mutations can occur anywhere on the 21 exons and to date more than 200 different mutations have been identified. Some cases of WD can occur due to spontaneous mutations. Most patients have no family history of WD. People with only one abnormal gene are called carriers. Furthermore, it has been noted that heterozygote’s (gene carriers who do not show signs of the disease) may have mild abnormalities of copper metabolism. This conclusion is still controversial and under review by the National Academy of Sciences and may be closely linked to increased copper in the diet or drinking water. It has been difficult to devise a simple genetic screening test for the disease due to so many mutations. However, in a particular family, if the precise mutation is identified, a genetic diagnosis is possible. This may help in finding symptom-free relatives so that they may be treated before they become ill or show signs of the disease. Diagnosis The earlier the diagnose of WD, the better the chance of definitive treatment. Without diagnosis and consequent proper treatments, severe liver damage occurs before there are signs of the disease. Those with WD may appear to be in excellent health while copper is accumulating. This is why it is such a problem for the small number of those inflicted throughout the developing world which lack access to correct diagnosis and treatment.
Some diagnostic tests are: ophthalmologic slit lamp examination for Kayser-Fleischer rings (small green to brown rings on the cornea); Serum ceruloplasmin test (copper containing protein in blood serum); 24-hour urine copper test; liver biopsy for cell values of copper and genetic testing, haplotype analysis for siblings and mutation analysis (finding the specific gene that causes the disease in the patient). At present there is no ability to perform prenatal testing. Treatment With proper therapy, disease progress can be halted and symptoms improved. Treatment is aimed at removing excess accumulated copper and preventing its re-accumulation. Therapy must be met with strict compliance and is lifelong. Treatment is not curative. Successful treatment began in 1956 with the use of penicillamine which binds to copper. This form of treatment does not correct the problem but increases the elimination of copper into urine and prevents copper overload and its effects on organs. Vitamin B6 (pyridoxine) can be given with penicillamine, to counter the possibility for deficiency of this vitamin to develop during chronic penicillamine administration. An alternative to this conventional treatment is triethylene tetramine dihydrochloride (Trien). It is a suitable alternative binding agent with fewer side effects. Also, oral zinc acetate has proved highly effective by blocking copper in the intestinal tract which involves greater binding of dietary copper and decreased overall absorption. Tetrathiomolybdate, a molecule that forms stable tripartite complexes with protein and copper is undergoing clinical trials as therapy for WD. This drug both decreases copper absorption and reduces circulating free copper. It is fast acting and can restore normal copper balance within several weeks compared with several months required with other copper chelators or with zinc. It should also be said that liver transplantation can reverse the basic metabolic abnormality and improve both hepatic and neurological symptoms. Other than pharmacologic treatment, dietary restriction of shellfish and liver as well as drinking water sources must be monitored for copper concentration. Lastly, in newly diagnosed patients, there is also frequent need for speech therapy, physical or occupational therapy, and psychiatric counseling. Many of
Women’s Health (General)
the above seemingly simple treatment measures may not be available for much of the developing world and lead to no treatment and consequential death. Worldwide In regions that have increased copper in the diet or a disproportionate amount of copper in the drinking water supply, this may cause a faster and more lethal threat. If WD can be diagnosed early and treated adequately the prognosis is favorable. However, in areas where access to healthcare, proper diagnosis and treatment are not accessible the prognosis is poor. SEE ALSO: Drinking Water; Ecogenetics; Genetic Disorders;
Liver Disease (General); Vitamin and Mineral Supplements.
Bibliography: American Association for the Study of Liv-
er Diseases, www.aasld.org/eweb/docs/wilson_withcorrection.pdf (cited June 2007); George Brewer, Wilson’s Disease for the Patient and Family: A Patient’s Guide to Wilson’s Disease and Frequently Asked Questions About Copper (Xlibris Corporation, April 2002); Stephan Kaler, Cecil: Text Book of Medicine. Part XVI Metabolic Diseases, Section 224 Wilson’s Disease (Saunders 2004); Eva Roberts, and Michael Schilsky, “A Practice Guideline on Wilson Disease,” Hepatology (June 2003); Wilson’s Disease gene mutation main database, www. medgen.med.ualberta.ca/wilson (cited June 2007), Wilson’s Disease, www.wilsonsdisease.org. John Michael Quinn V, MPH University of Illinois at Chicago
Women’s Health (General) Any influence on a woman’s physical, psychological and emotional well being is a women’s health issue. Historically women’s health was limited to reproductive health; after landmark research such as the Harvard Nurses’ Health Study, science and medicine take a more holistic view of women’s health by assessing disease risk and prevention, understanding how women differ from men on shared health concerns, and recognizing the influence of work, relationships and society on women’s health. From a biological perspective, health issues related to the female reproductive organs, including the men-
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strual cycle, pregnancy, and childbirth and illness associated with the female reproductive organs are gender-specific health issues. Some health issues are more common to women—breast cancer, domestic violence/ abuse, rape, eating disorders, osteoporosis. Heart disease (earlier seen mainly and studied in men) is now the leading cause of women’s death in the United States. Globally, issues relating to women’s health include: prenatal and maternal health services, quality of care in pregnancy termination; safe sex promotion, contraception, and care of sexually transmitted diseases, insurance coverage for the cost of contraceptives, primary care services, and screening for breast and cervical cancer. Women’s health can also be greatly assisted by making domestic violence and rape a public health issue, and providing counseling and shelter to women in need. REPRODUCTIVE HEALTH The ovarian cycle is the cyclical preparation of the human female reproductive organs for conception. Menarche (the first menstrual period) occurs between the ages of 11 and 15. The menstrual/ovarian cycle continues until climacteric or menopause between the ages of 48 and 55. Each woman experiences variations in timing and duration of the cycle from 25 to 35 days, with an average of 28 days. Pregnancy is the fertilization and implantation of the fertilized embryo. During the approximately 40 weeks of gestation, medical care includes prenatal care to ensure health of child and mother, as well as promoting preventive measures including nutrition and appropriate weight gain. Classes on childbirth can help women relax during birth and provide techniques to reduce pain and stress. Breastfeeding after childbirth has both benefits and risks, and new mother’s should be provided with information. A controversial women’s health issue is abortion. Governments can ensure safe and quality care in abortions by preventing the politicalization of the issue, which will decrease the potential for unsafe abortions performed by untrained professionals under unsanitary conditions. Menopause is the permanent cessation of monthly menstruation and the beginning of related medical issues associated with the end of childbearing. Menopause occurs between the ages of 48 and 55, with an average age of 51. For five to ten years before menopause, changes in the endocrine and ovarian system
1764 Women’s Health (General) result in menstrual cycle changes (shorter periods, irregular periods, changes in menstrual flow). The gradual reduction in the production of estrogen hormones leads to changes in estrogen-responsive tissues— vagina, vulva, uterus, bladder, urethra, breast, bones, heart, blood vessels, brain, skin, hair and mucous membranes. Clinical evaluation during this time is essential for baseline testing and risk awareness for associated health issues including heart disease and osteoporosis. OTHER HEALTH ISSUES Women may experience a variety of issues depending on their stage of life. Heart disease is the leading cause of women’s death in the United States. Though women develop atherosclerosis (the buildup of plaque on the walls of blood vessels), females tend to experience heart disease differently from men. Women have a decreased risk of heart disease during the reproductive years and an increased risk after menopause. Women are less likely to experience chest pain and in diagnostic stress testing as their hearts responds differently, making it difficult for clinicians to interpret abnormalities.
Osteoporosis is a systemic and often debilitating skeletal disease in which bones become less dense and brittle, with increased susceptibility to fracture. Preventive measures should begin before menopause and include maintaining a healthy diet with adequate protein and calories, as well as nutritional supplementation with calcium and vitamin D. A wide range of medication treatment options includes hormone replacement, and medications that improve bone density and prevent the removal of calcium from bones. Eating disorders share the primary characteristic of eating disturbances (anorexia, bulimia, pica) and often a preoccupation with food and weight, poor self esteem, and distorted body image. Reported in 4 percent of adolescent and young adults, the age of onset is mid-teens and early 20s. Routine cancer screening for breast cancer include breast self exams and mammography to detect the presence of lumps in the breast. Routine pap tests can identify abnormal cells from the cervix and other parts of the female reproductive tract, and should reveal cancer in its early stages. Vaccination protects against infectious diseases. In addition to measles, mumps, polio, Hepatitis B and Hepatitis, and smallpox, the need for vaccination differs depending on the part of the world and the endemic infections within the populations. The newest vaccination recommended for human papillomavirus (HPV) was approved for use in the United States, Canada and the European Union in 2006. The recombinant vaccine, marketed under the names Gardisil and Silgard , is used as a prophylaxis against diseases (including prevention of cervical cancer) caused by four types of HPV. The vaccine is given in three doses (an initial dose, a second dose two months later, and a third dose 6 months from initial dose). Clinical study data shows that the vacccine is 100 percent effective in preventing cervical precancers and non-invasive cervical cancers related to HPV 16 and HPV 18 types. It is 95 percent effective in preventing adenocarcinoma in situ, and 100 percent effective in preventing vulvar and vaginal precancers related to HPV 16 and HPV 18.
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All nations should have legislation and enforcement mechanisms in place to protect women from battery, rape, and forced prostitution.
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PSYCHOLOGICAL/EMOTIONAL WELL-BEING The difference between mental health and mental illness is a fine line and must be understood in the context of each individual’s thoughts, actions and performance of daily activities such as work, school,
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sleep, self-care, caregiving and social relationships. Types of mental illnesses include anxiety disorders, mood disorders, psychotic disorders, personality disorders, cognitive disorders, dissociative disorders, somatoform disorders, factititious disorders, substance related disorders, impulse-control disorders and eating disorders. Post-partum depression pertains specifically in women. Post-partum depression occurs anywhere from two weeks to six months after giving birth. Many women experience mood changes attributable to hormonal changes. Psycho-social stressors and symptoms may be relieved with reassurance and support. For severe depression, sleep deprivation, volatile behavior and manic-like symptoms, medication therapy is indicated. Women may also experience Seasonal Affective Disorder (SAD), a depression which reoccurs during the fall and winter months. The body goes into pseudo-hibernation behavior (long periods of sleep, overeating calories and sweets). The diagnosis is made by exclusion of other illnesses and must only occur on a seasonal basis. Treatment with light therapy, counseling, and anti-depressant medication may help relieve symptoms. Post traumatic stress disorder is common in women after trauma (rape, abuse, and other crises). Counseling combined with behavior modification therapy, relaxation, stress management allows the woman to accept the trauma and recover a sense of control.
reduced risk for some cancers (breast, lung, colon, pancreas), and added bone strength to gain or maintain density. Psychological benefits include the release of endorphins which can act as an antidepressant, decrease stress, and improve coping skills. Cosmetic changes to improve appearance include cosmetic dentistry, plastic surgery, breast augmentation, botox and collagen injections, chemical peels, and dermabrasion. Most cosmetic interventions are elective (not required for medical health) and not covered by insurance. The risks include pain, discomfort, infection, bleeding, nerve damage and scarring. Caution should be taken to make sure the procedures are performed by a trained professional and under the supervision of a physician who will assess the overall health of the woman and monitor any health considerations (diabetes, high blood pressure, allergies, asthma and substance abuse) to reduce the risk of complications. Smoking in women can lead to damage to the respiratory and cardiovascular systems, low birth weight in children, accelerated onset of menopause, increased chance of premature delivery, miscarriage, still birth, osteoporosis and skin damage. The benefits to quitting smoking include a reversal of the risks associated with chronic illness. A variety of smoking cessation techniques are available and can be combined with a formal program, support from family and friends, Aids to quitting include nicotine replacement (patches, gum, inhaler) and medications.
LIFESTYLE Proper nutrition and weight control are important because of obesity-associated risks for developing chronic disorders like heart disease, stroke, diabetes, colon cancer. The diet should contain enough nutrients for the maintenance of healthy weight, contain fiber, limit fats and sweets, and have sufficient variety to ensure the vitamins and mineral necessary for biochemical functions. Exercise is recommended for everyone to develop healthy and fit lifestyle, to prevent obesity, and to minimize risks of disease. Research suggests a 30 minute brisk walk, several times per week will maintain physical fitness. Weight training may be of great benefit in preserving bone mass, increasing strength and balance, adding muscle mass, and improving metabolism. The physical benefits of any type of exercise include lessened risk for heart attacks, strokes,
SAFETY In addition to actions women can take to protect themselves from dangerous situations, including taking self-defense classes and practicing safe sex, all nations should have legislation and enforcement mechanisms in place to protect women from battery, rape, and forced prostitution. These are health issues due to the short-term and long-term impacts on women’s well-being; counseling and shelter should be available and accessible to women for protection from dangerous situations. Safe sex practices are intended to protect a woman from sexually transmitted diseases. Women should not have sex with anyone who hasn’t been tested for HIV, and should use a condom or latex barrier for sex and oral/genital contact. Monogamous, long-term relationships in which both parties have been tested for STDs may allow for an exception.
1766 World Health Organization (WHO) Domestic violence and child abuse are challenging for medical professionals to treat. Victims may be reluctant to leave their domestic situation, and if a girl or woman does chooses to leave, she needs a safe haven. Sexual abuse of female children can lead to scarring and damage of the genitals, rectum, mouth and throat, and an increased risk for sexually transmitted disease. Long term psychological effects include depression, substance abuse, self-destructive behavior, eating disorders, and sexual dysfunction. Treatment by counseling and support groups are recommended. While rape is a nonconsensual and violent crime of penetration of vaginal/anal/oral openings by a penis, hand, or object and can involve servere physical injury and psychological aftermath, various jurisdictions define the crime differently. The medical team must take proper care to collect the necessary specimens for law enforcement in a respectful manner. Treatment options should include vaccination for Hepatitis B virus, tetanus toxoid for deep injuries or exposure to soil, prophylactic antibiotics for sexually transmitted diseases, and the offer of post-coital contraception information as well as psychological support. Sexual harassment is defined as unwanted sexual attention in a situation with an inequality of power. Often the victim feels she must endure the treatment or suffer adverse consequences. The emotional stress can lead to substance abuse or other risks to health and well-being. Victims must understand they did not ask for the sexual harassment and are not to blame. Women may find support from other women or from women’s advocacy organizations. Occupational safety is often overlooked as a source of women’s illnesses, but include respiratory, musculoskeletal, and reproductive damage from exposure to hazardous materials while on the job. Hazardous materials include exposure to airborne particles, chemical and radiation exposure, repetitive stress and strain, sharp objects, and heavy machinery. Women in low paying jobs with low job security may hesitate to complain about working conditions and don’t have time to research options for job safety because of balancing work and home life. see also: Abortion; Birth Control/Contraception; Cli-
macteric; Gynecology; Hormones; Infertility; Menstruation and PMS; Mental Health; Nutrition; Obstetrics; Occupational Safety and Health Administration (OSHA);
Pregnancy; Psychiatry; Psychology; Reproductive Health; Sexual Health (General); Uterine Diseases. BIBLIOGRAPHY. Karen J. Carlson, Stephanie A. Eisenstat,
and Terra Ziporyn, The Harvard Guide to Women’s Health (Harvard University Press, 1996); Paul A Fitzgerald, “Endocrinology” Current Medical Diagnosis and Treatment (Lange Medical Books, 2004); “HPV Vaccine for the Prevention of Cervical Cancer and Other Diseases in EU” ctep. info.nih.gov; Graham A. Colditz, Susan E. Hankinson, et al., Healthy Women, Healthy Lives A Guide to Preventing Disease from the Landmark Nurses’ Health Study (Simon & Schuster, 2001); Trent MacKay, “Gynecology” Current Medical Diagnosis and Treatment (Lange Medical Books, 2004); Fred Neff, Self-Protection Guidebook for Girls and Women (Lerner Publications Co, 1977); World Health Organization, “Vienna Statement on Investing in Women’s Health in the Countries of Central and Eastern Europe, 1994” www.euro.who.int (cited August 2007). Lyn Michaud Independent Scholar
World Health Organization (WHO) The World Health Organization (WHO) is the United Nations agency responsible for promoting good health among all peoples of the world. Addressing health disparities between the developed and developing world has become a major focus of WHO activity. The foundation for an international health organization can be traced to July 1851 when Paris hosted the first Sanitary Conference in the midst of the Industrial Revolution with the expressed intention of developing measures to eradicate plague, yellow fever, and cholera. A number of other countries established their own sanitary boards, and the United States founded the Pan American Sanitary Bureau. However, there was a general consensus that a permanent international health organization was needed. In 1907, the Office International d’Hygiène Publique was founded in Paris, and the scope of activity soon expanded to include nutrition and housing. The establishment of the United Nations (UN) in the postwar era paved the way for the creation of WHO
on April 7, 1948. WHO was charged with attaining the highest possible levels of health on a global basis. According to WHO’s constitution, health refers to “a state of complete physical, mental, and social well-being and not merely to the absence of disease or infirmity.” Much of the work of WHO has been concentrated on improving the lives of children, and in the late 1970s, WHO joined forces with the United Nations Children’s Fund (UNICEF) to promote access to primary healthcare for all children. Governance is provided by the World Health Assembly, which is composed of representatives from 193 member states. This Assembly serves as the policy-making body of WHO. An Executive Board of 34 health professionals makes policy recommendations and facilitates the work of the Assembly. Day-to-day governance is carried out by the Director-General who is assisted by nine Assistant Directors-General. Two assistants serve as general advisers, and the other seven are responsible for Evidence and Information for Policy, Communicable Diseases, Noncommunicable Diseases and Mental Health, General Management, Family and Community Health, Sustainable Development and Healthy Environments, and Health Technology and Pharmaceuticals. The Secretariat is a body of 3,500 health professionals, experts, and support staff who carry out daily activities. WHO is headquartered at Avenue Appia 20, 1211 Geneva 27, Switzerland. E-mail (
[email protected]) is the preferred channel for general inquiries, but WHO can be reached by telephone (+421 22 791 21 11) or telegraph (UNISANTE GENEVA). WHO’s Web site (http://www.who.int/en/) is a major resource for information on the organization and for research on global health issues. WHO also maintains six regional offices: Africa (Brazzaville, Congo), the Americas (Washington, D.C.), southeast Asia (New Delhi, India), Europe (Copenhagen, Denmark), eastern Mediterranean (Cairo, Egypt), and western Pacific (Manila, Philippines). WHO officials and researchers publish a substantial quantity of material, which can be purchased at the online book store and is available in many academic libraries. The WHO Library database indexes information on WHO publications from 1948 to the present. The Bulletin of the World Health Organization is a general journal that contains research findings and policy-based discussions. Journals that
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focus on specific regions include the Eastern Mediterranean Health Journal and the Pan American Journal of Public Health. The Weekly Epidemiological Record serves as a tool for the collation and dissemination of epidemiological data, granting priority to diseases and risk factors that endanger international health. The World Health Report focuses on a specific theme each year, addressing the topic from a holistic perspective. WHO serves as a valuable resource for statistics on all issues affecting global health. A detailed online country database contains information on the state of health in individual countries, and WHO Drug Information provides a wealth of pharmaceutical material. Statistical information is also available on health systems, the burden of disease, mortality, annexes of The World Health Report, and specific diseases and conditions. A global atlas of the health workforce and the WHO Global Infobase may also be accessed online. WHO’s multimedia center contains audio, video, and photographic resources. In 2006, WHO joined with 29 international partners to warn consumers around the world that half of all medicines sold through rogue Web sites are fake. These medicines may cost lives because they do not treat diagnosed conditions and may provoke drug resistance. According to WHO estimates, a third of all medicines sold in some areas of Latin America, southeast Asia, and sub-Saharan Africa, and a fifth of those sold in former Soviet republics are counterfeit. In highly developed countries with strong regulatory methods, less than 1 percent of medicines sold on the market are counterfeit, but the percentage of counterfeit internet drugs is 50 percent. WHO is involved in ongoing programs that target diseases and practices that threaten populations, such as those dealing with the elimination of water-, air-, and vector-borne diseases that are common among the poorest nations of the world. WHO is also heavily involved in responding to the global HIV/AIDS crisis. WHO estimates that 39.5 million people are currently living with HIV/AIDS, and reports indicate that 4.3 million people were infected with the disease in 2006. Some 65 percent of those were concentrated in subSaharan Africa. Infection rates in eastern Europe and central Asia have risen by more than 50 percent since 2004. Around the globe, 2.9 million people died in 2006 from AIDS-related illnesses.
1768 Wrist/Arm Injuries and Disorders WHO closely monitors outbreaks of infectious diseases and health crisis situations. In January 2007, for instance, WHO officials reported outbreaks of avian influenza in Indonesia and Egypt and Rift Valley fever in Kenya. That same month, WHO identified an emergency health crisis in Chad after nonessential UN workers were withdrawn. Ethiopia, Kenya, and Somalia were all in crisis as a result of heavy flooding that led to displacement, crowded living conditions, and lack of access to safe water and sanitation. It was estimated that between 1.5 and 1.8 million people were at risk for contracting cholera, measles, malaria, and nutritional deficiencies. SEE ALSO: Disease Prevention; Healthcare, Africa; Health-
care, Asia and Oceania; Healthcare, Europe; Healthcare, South America; Healthcare, U.S. and Canada; United Nations Children’s Fund (UNICEF). BIBLIOGRAPHY: Maggie Black, Children First: The Story of
UNICEF, Past and Present (Oxford University Press, 1996); Anne-Christine D’Adesky, Moving Mountains: The Race to Treat Global AIDS (Verso, 2004); William H. Foege, et al., Global Health Leadership and Management (Jossey-Bass, 2005); Philip J. Hilts, Rx for Survival: Why We Must Rise to the Global Health Challenge (Penguin, 2005); Introducing WHO (World Health Organization, 1976); Michael H. Merson, et al., International Public Health: Diseases, Programs, Systems, and Policies (Aspen, 2001); Joyce Brennfleck Shannon, ed., Worldwide Health Sourcebook (Omnigraphics, 2001); Javed Siddigi, World Health and World Politics: The World Health Organization and the UN System (University of South Carolina Press, 1995); World Health Organization, The Second Ten Years of the World Health Organization, 1958–1967 (World Health Organization, 1968). Elizabeth R. Purdy, Ph.D. Independent Scholar
Wrist/Arm Injuries and Disorders The wrist is a complex joint formed by the articulation of several bones surrounded primarily by ligaments creating one of the most essential components of the upper limb. Given the primarily bony and ligamen-
tous components comprising the joint of the wrist, injuries to this region as a result of trauma are more numerous due partly to the lack of strong surrounding muscular attachments. Disorders of the wrist and arm frequently result from repetitive use injuries, the most notable being that of carpal tunnel. In general, the most common disorders plaguing the wrist and arm can be classified and further differentiated based on the surrounding ligamentous origin of the disorder, bony fracture involvement, and/or the arthritic components of the ailment. The proximal segment of the hand, otherwise recognized as the wrist, consists of the carpal bones, their articulation with the radius and ulna, and the associated soft tissue supporting structures. The wrist is composed of eight carpal bones arranged in rows of four. The carpal bones are unique in their alignment and articulations providing flexibility to the wrist. Movement at the wrist joint is achieved by the two rows of carpals gliding on one another as well as each carpal gliding against the adjacent carpal bone. Similar action takes place with the movements between the carpals and the radius and ulna. The radius and ulna comprise the bony structures of the lower arm. Providing the essential link between the upper arm and hand, these two bones and their muscular/ligamentous attachments are often the site of common disorders. The wrist joint is frequently injured in a wide variety of activities ranging from sport-related to repetitive overuse in the work environment. Injury may result from a direct traumatic event, such as falling on an outstretched arm, or as a result of repetitive use, including such activities as typing. Any activity that requires the use of the hands and fingers, especially a motion in which the repetitive nature of the activity will continuously create friction between the ligaments crossing the wrist joint to the fingers, may stress the surrounding tissue that comprises the joint to the point of injury. Carpal Tunnel (Compression Neuropathy) Representing the most common of all nerve entrapment syndromes, carpal tunnel syndrome is a compilation of distinctive symptoms and signs that occurs most often as a result of repetitive use. Inflammation and the resulting swelling lead to the characteristic symptoms
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following the entrapment of the median nerve within the carpal tunnel. Usual symptoms include a lack of sensation, paresthesias (an abnormal sensation, such as of burning, pricking, tickling, or tingling), and pain in the median nerve sensory distribution. Therefore, these symptoms could be accompanied by noticeable differences in strength of median nerve supplied structures in the hand, which are the thumb and musculature involved in opposition. This weakness will often be demonstrated by the inability to hold a coffee cup, for example. A definite cause of the syndrome is far from clear. It is suspected that a complex interaction between any number of activities of daily living, work habits, demographical influence, and even genetic factors play a role. The multifactorial nature of the syndrome is evidenced by the fact that even joint swelling that has resulted from other causes such as pregnancy or injury may also apply pressure to the nerves that travel through the wrist. Any localized swelling in this particular region can cause damage to the nerves and develop compression neuropathy or lead to carpal tunnel syndrome. Tennis Elbow (Lateral Epicondylitis) Lateral epicondylitis has been demonstrated to occur in up to 50 percent of tennis players. However, this condition is not limited to tennis players and has been reported to be the result of overuse from many activities. Lateral epicondylitis is extremely common in today’s active society. Individuals complaining of lateral elbow and forearm pain exacerbated by use with the typical history of repetitive use activities are likely to be suffering from lateral epicondylitis. The classic individual is a man or woman aged 35 to 55 years who is either a recreational athlete or one who engages in rigorous daily activities. Nonsurgical treatment is the mainstay of care for patients with lateral epicondylitis. The goal of initial treatment is the termination of the injurious activity. Often the use of a brace and nonsteroidal antiinflammatory drugs (NSAIDs) provide relief of symptoms. The use of wrist splinting and/or corticosteroid injections may also be necessary. Sprain The ligaments of the wrist may be compromised, for example, during a fall. The natural response to sudden loss of balance is to move the hands to brace for poten-
Disorders of the wrist and arm frequently result from repetitive use injuries, the most notable being carpal tunnel.
tial fall. Once the hand makes contact with the surface of support, the wrist is likely to be forced either into a flexed or extended position, which can stretch and perhaps tear the ligaments that connect bone to bone within the joint. The resulting injury is a sprain. Wrist sprains are graded, depending on the degree of injury to the tissues. The range of sprain falls between the grades of 1 to 3. Signs and symptoms of a wrist sprain may vary in intensity and location, depending on the mechanism and degree of injury. Indications of a wrist sprain include swelling of the effected region, tenderness on movement or palpation and possibly a bruising or discoloration of the surrounding skin. Fracture Several bones comprise the bony articulations of the wrist each susceptible to injury themselves. In discus-
1770 Wrist/Arm Injuries and Disorders sion of the common fractures of the wrist, six bones make up the frequent wrist joint fracture locations: the two bones of the lower arm (the radius and the ulna) and four of the eight wrist bones (carpals). Fracture of both the radius and ulna are usually the result of severe trauma. Isolated fractures also occur and will usually be associated with dislocation of communicating joint structures as the two bones are connected by a membrane to aid in their stability. Direct injury may be responsible to injury to any bony component of the joint. Osteoporosis (resulting in weakening of the bone matrix) is a common associated risk factor in fractures of these bones. Injury typically results secondary to an accidental fall, with the resulting impact being absorbed in the wrist to brace the fall. The scaphoid (the carpal behind the thumb in contact with ulna) is the most frequently fractured carpal bone. Again, it often results from a fall on the palm with the arm and hand outstretched for support. Pain will ensue and initial radiograph of the affected region may not demonstrate the fracture and a more severe injury may be misinterpreted as a severe sprain. With poor blood supply to this region, and possibly further compromised by injury, the healing process is quite long (up to three months) with the ever-present risk of avascular necrosis (death of bone secondary to inadequate blood supply) creating a degenerative joint disease. In extreme cases, it may be necessary to surgically fuse the joint (arthrodesis) as a last resort for treatment. Arthritis Arthritis affects millions of people in the United States. Often, arthritis strikes at the weight-bearing joints of the body, such as the knees and the shoulders. But a significant number of people suffer from arthritis in their wrists and hands that make it difficult for them to perform the activities of daily living. Two major designations exist with regard to the arthritic classifications, which are those of arthritis derived from either an osteopathic or rheumatologic origin. Osteoarthritis, commonly referred to as degenerative joint disease, is one of the most common causes of disability in the developed world. Individuals younger than 55 years have an equal distribution of affected joints regardless of gender. Osteoarthritis of the wrist joint typically manifests with pain, swelling of the joint, weakness, and a lim-
ited range of motion. These symptoms are usually limited to the wrist joint itself. Osteoarthritis is a progressive condition that destroys the smooth articular cartilage covering the ends of bones. The bare bones rub against each other, resulting in pain, stiffness, and weakness. Osteoarthritis can develop due to normal “wear and tear” on the wrist or as a result of a traumatic injury to the forearm, wrist, or ligaments. The principal pathological feature of osteoarthritis is the progressive erosion articular cartilage. The cartilage will then become soft, frayed, and progressively thinned. Eventually, the exposed bone (subchondral) will convert to a more dense substance with a smooth surface, a process known as eburnation. Simultaneously, there will be bony protuberant outgrowths, known as osteophytes, from the bone margins, ultimately leading to pain and loss of function as a result. Rheumatoid arthritis is a systemic inflammatory disease that affects the joint linings and destroys bones, tissues, and joints. Rheumatoid arthritis often starts in smaller joints, such as those found in the hand and wrist, and is symmetrical, meaning that it usually affects the same joint on both sides of the body. Rheumatoid arthritis of the wrist joint usually manifests in tenderness, limited range of motion, and swelling, and decreased grip strength is usually observed. Hand function, such as writing and grasping, may be impaired and there may be pain in the joints forming the knuckles. The disease is more prevalent in women and predominantly affects connective tissue; arthritis is the dominant clinical manifestation. This form of arthritis frequently involves many joints. The pathology of rheumatoid arthritis varies from that of osteoarthritis with the former representing an inflammatory process and the latter representing a noninflammatory condition. In addition, osteoarthritis creates a thinning of connective articular membranes, whereas rheumatoid arthritis will be accompanied by thickening of articular soft tissue, with extension of synovial tissue over articular cartilages, which become eroded; the course is variable but it is often chronic and progressive, leading to deformities and disabilityWhen conservative methods are no longer effective or if hand function decreases, surgery is an option. The goal of surgery is to alleviate pain and suffering. With regard to the maintenance of function, prognosis depends on the type of surgery; joint
function may be affected. Surgical options include removing the arthritic bones, joint fusion (making the joint solid and preventing any movement at the wrist), and joint replacement. SEE ALSO: Arthritis; Fractures; Hand Injuries and Disor-
ders; Rheumatoid Arthritis; Surgery.
BIBLIOGRAPHY: David Fuller, Carpal Tunnel Syndrome,
www.emedicine.com/orthoped/topic455.htm (cited July 2004); D. L. Kasper, et al., Harrison’s Principles of Internal Medicine, 16th ed. (McGraw-Hill, 2005); Keith L.
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Moorse and Arthur F. Dailey, Clinically Oriented Anatomy, 5th ed. (Lippincott Williams and Wilkins, 2006); Robert A. Novelline, Squires Fundamentals of Radiology, 6th ed. (Harvard University Press, 2004); E. Seeman and P. D. Delmas, “Bone Quality—The Material and Structural Basis of Bone Strength and Fragility,” New England Journal of Medicine (v.354/21, 2006); Jakub Tolar, MD, Ph.D., et al., “Osteoporosis,” New England Journal of Medicine (v.351, 2004). Donald Hohman, Jr. Kern Medical Center
Y Yemen Yemen is located on the southern tip of the Arabian Peninsula, bordered to the south and west by the Arabian Sea and the Red Sea and to the north by Saudi Arabia and Oman. The region was part of the Ottoman Empire for generations, but at the end of World War I, the Western powers redrew the maps of the Middle East to create a variety of new countries, including North and South Yemen. These two countries did not formally unite until 1990. With little oil and a harsh desert climate, Yemen is today the poorest country in the Middle East. Yemen’s population is 22.2 million, growing at almost 3.5 percent annually. This is largely driven by a high birth rate; there are 42.67 births per 1,000 population and the fertility rate is 6.49 births per women. Life expectancy is low for the region, at approximately 61 years for males and 65 years for females. Infant mortality is 76 deaths per 1,000 and under-5 mortality is 102 per 1,000. This is an improvement over the 1990s, but high for the region as a whole. More than 45 percent of Yemenis live below the poverty line, with unemployment affecting 35 percent of the population. Less than a quarter of Yemenis work in the industrial or service industry. Most people work in agriculture or herding. Only 26 percent live in urban areas.
There are few widespread communicable diseases in Yemen, many of them stemming from poor sanitation, especially outside the cities. Only 28 percent of Yemenis outside the cities have sanitary facilities, and only 43 percent can access safe drinking water. Rates of various strains of hepatitis are high. Immunization rates among children are generally low. In 2000, there was a serious outbreak of Rift Valley fever (a viral hemorrhagic fever spread by animals that have been bitten by infected mosquitoes), and in 2005, there was a small polio epidemic. The chewing of qat, the leaves of a tree widely cultivated in eastern Africa and the Arabian peninsula, is practiced by the majority of adults in Yemen and holds an uncertain place in the country’s health profile. Qat is pharmacologically similar to amphetamines, providing users with a mild boost of energy. There is some belief that it also eases digestive disorders, relieves asthma attacks, and stabilizes blood sugars. Others believe that long-term usage can cause cardiovascular damage and increase the risk of oral, esophageal, and intestinal cancers. Overuse can lead to anxiety, depression, and loss of appetite, and may be particularly harmful to those predisposed to mental illness. Women in Yemen have the highest rates of maternal mortality in the region, with 336 deaths per
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100,000 live births. An estimated eight women die in childbirth every day. Researchers believe that 75 percent of those deaths are preventable, and stem mostly from social issues. Child marriage is not uncommon in Yemen, with 14 percent of girls married by the age of 15; early childbearing often results in maternal death. Literacy and education among women is restricted, and poverty increases the likelihood of malnutrition and general poor heath. Another risk factor is the continuing practice of female genital mutilation. Almost 85 percent of Yemeni women give birth at home, without the help of trained assistants or close access to medical facilities. Access to medical care is a problem for many Yemenis. There is a countrywide shortage of doctors, with only one physician for every 10,000 people. Medical services are concentrated in or near the main
cities, leaving 40 percent of the population with little chance to receive treatment. SEE ALSO: Healthcare, Asia and Oceania. BIBLIOGRAPHY: Abdul W. Al Serouri, et al. eds., Cost Sharing
for Primary Health Care: Lessons from Yemen (Oxfam Working Papers) (Oxfam Publishing, 2002); CIA, “Yemen,” World Factbook, www.cia.gov/library/publications/the-world-factbook/geos/ym.html (cited June 2007); World Bank, Republic of Yemen: Health Sector Review (World Bank Country Study) (World Bank, 1994); World Health Organization, The World Health Report 2006: Working Together for Health (World Health Report) (World Health Organization, 2006). Heather K. Michon Independent Scholar
Z Zambia Zambia is located in southern Africa, bordered by eight other countries: the Democratic Republic of the Congo, Tanzania, Malawi, Mozambique, Zimbabwe, Botswana, Namibia, and Angola. Explorer David Livingstone discovered the magnificent Victoria Falls on the Zambizi River in 1855, but the region was largely untouched by Europeans until British mining interests led by the colonialist Cecil Rhodes arrived in the late 1880s; the entire area (including present-day Zimbabwe) was named Rhodesia in his honor. Northern Rhodesia won full independence from the British in 1964 and took the name Zambia. It has since struggled to build and maintain a stable government. The collapse of copper prices in the 1970s destroyed the national economy. Today, seven in 10 Zambians live in poverty and AIDS rates are among the world’s highest. The population is 11.5 million, growing at 1.7 percent annually. The AIDS epidemic and increased child mortality rates are the driving factors of this slow population growth, and life expectancy is now in decline. In 1980, life expectancy was 52 years; by 2003, it had dropped to 37. Infant mortality is 102 deaths per 1,000 births. For children, 182 of every 1,000 will die before their fifth birthday. Maternal mortality varies, with an overall rate of 750 deaths
per 100,000 live births, but increasing to perhaps 1,300 deaths per 100,000 births in rural areas. The Zambian government has taken affirmative steps to deal with the country’s economic problems in recent years, and there are some signs of better days ahead. That said, 64 percent of the population gets by on less than $1 a day, and 86 percent live in poverty. Food insecurity has been a problem for about 60 percent of all Zambians since the early 1990s. A prolonged drought in recent years has reduced crop yields to critical levels, and the World Health Organization believes that 1.2 million Zambians currently need food aid. Close to 30 percent of children under the age of 5 are underweight, and 47 percent show signs of stunting. Zambia has a high burden of communicable diseases, particularly in rural areas, where 35 percent of people have access to safe water and 71 percent have sanitary facilities. Diarrhea, typhoid, and hepatitis A are prevalent in many areas. Vector-borne diseases such as malaria are endemic in many regions. Most deaths in children under 5 are attributable to malaria. Immunization planning is poor, and drug inventories lack many needed medications with which to treat the ill. Like its neighbors, Zambia suffers from a sweeping AIDS epidemic, with 17 percent of the population infected with the virus. This means that one out
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1776 Zimbabwe of every six Zambians between the ages of 15 and 49 is now infected. Four times as many women between 15 and 24 are infected as men of the same age, and there is a high level of mother-to-child transmission. In 2005, there were approximately 44,000 people receiving antiretroviral drugs out of an estimated 183,000 who were in need of treatment. The government has committed itself to halt the spread of the disease, and the rate of increase seems to have stabilized in the past few years. Zambia is still a rural country, with only 36 percent of the population living in urban areas. In the cities, 90 percent of people have some access to medical care, but in the countryside, only about 50 percent are within walking distance of a facility. Medical transport between the rural areas and the cities are infrequent. Hospitals routinely lack electrical power and water. The country also suffers to a high degree from a “brain drain” of medical personnel, with many trained professionals choosing to leave the country for better opportunities abroad. SEE ALSO: AIDS; Disease and Poverty; Healthcare, Africa. BIBLIOGRAPHY: Joseph M. Kasonde and John D. Martin,
eds., Experiences With Primary Health Care in Zambia— Public Health in Action (World Health Organization, 1994); Kelley Lee, ed., Health Impacts of Globalization: Towards Global Governance (Palgrave Macmillan, 2003); Oliver S. Saasa and Jerker Carlsson, Aid and Poverty Reduction in Zambia: Mission Unaccomplished (Nordic Africa Institute, 2002); World Health Organization Regional Office for Africa, The Health of the People: The African Regional Health Report (World Health Organization, 2006). Heather K. Michon Independent Scholar
Zimbabwe Zimbabwe is located in southern Africa between the Zambizi and Limpopo Rivers, bordered to the north by Zambia and to the south by South Africa. For most of the 20th century, the area was known as Southern Rhodesia, named in honor of British colonialist Cecil Rhodes, who took control of the area in 1888. The
country followed a chaotic path to independence, and took the name of Zimbabwe in 1980. Under the control of a single president, the controversial Robert Mugabe, the government has pursued various schemes of land reform and redistribution of power from wealthy white landowners to common Zimbabweans. However, most of the citizens remain desperately poor. The population of Zimbabwe is 12.3 million, growing at 0.6 percent annually. The AIDS epidemic and high child mortality have stalled population growth and decreased life expectancy from 61 years in 1990 to 33 years in 2006. According to the United Nations Children’s Fund (UNICEF), Zimbabwe has seen one of the sharpest increases in child mortality in modern history: in 1990, there were 80 deaths per 1,000 for children under 5; by 2005, there were 132 deaths per 1,000. Maternal mortality has also risen dramatically, from 695 deaths per 100,000 live births in 1999 to over 1,000 deaths per 100,000 live births in 2002. Zimbabwe’s economy has declined precipitously in recent years, fueled in part by the cost of war with the Democratic Republic of the Congo between 1998 and 2002. Government services have ceased or have been severely restricted. A crackdown on illegal housing and businesses has left 700,000 homeless and out of work. The overall unemployment rate is 80 percent. Urban poverty rose 66 percent between 1995 and 2003. Over 80 percent of the population gets by on less than $2 a day. Food insecurity is also on the rise; the World Health Organization estimates that 3 million Zimbabweans, out of a total population of 11.3 million, are in need of food assistance. With much of the public water and sanitation system in disrepair, waterborne and food-borne illnesses are on the rise. Recent years have seen an increase in diarrheal diseases, and there have been several outbreaks of cholera. Malaria is a continuing problem. As the AIDS epidemic has expanded, tuberculosis cases have risen by 500 percent in the last decade. Zimbabwe has the world’s fourth highest rate of human immunodeficiency virus (HIV)/AIDS, and while the rate of infection has dropped slightly in recent years to 20.1 percent, an estimated 1.7 million Zimbabweans are currently living with the disease, and 3,000 die of AIDS each week. Donor support for those living with HIV is down to $4 per person per day, and only 24,000 of the 500,000 people who would benefit from antiretroviral drugs are currently being
Zoll, Paul
treated. Education programs have shut down for lack of funding. There is little help for the 1.1 million children orphaned by the diseases. While Zimbabwe once had a fairly modern medical infrastructure, it is today in a state of collapse. Any country where one in 10 citizens is chronically ill would be hard-pressed to provide adequate care, but in a country where government expenditure on healthcare is only $14 per person per year, and where 8 in 10 people are unable to pay for services, it has proven impossible. Many doctors and medical staff have left the country for better opportunities abroad. Many of those who remain are ill themselves, with an estimate 2.5 percent of remaining medical personnel dying each year from AIDS and other diseases. SEE ALSO: AIDS; Healthcare, Africa; Malaria. BIBLIOGRAPHY. Abel Chikanda, “Skilled health profes-
sionals’ migration and its impact on health delivery in Zimbabwe,” Journal of Ethnic and Migration Studies (v.32/4, 2006); Amy S. Patterson, ed., The African State And the AIDS Crisis—Global Health (Ashgate Publishing, 2005); World Health Organization Regional Office for Africa, The Health of the People: The African Regional Health Report (World Health Organization, 2006). Heather K. Michon Independent Scholar
Zoll, Paul (1911–99) American cardiologist who pioneered the development of the cardiac monitor, pacemaker, and defibrillator. Throughout his career, Zoll made fundamental contributions to the fields of electrical resuscitation of the heart, conversion of cardiac arrhythmias, longterm stimulation, and cardiac monitoring. Zoll was born on July 15, 1911, in Boston, where he grew up and received his primary and secondary education. After graduating from Boston Latin School, he entered Harvard College where he became increasingly interested in philosophy and psychology and obtained his degree in 1936. He attended Harvard Medical School and completed his internship at the Boston Beth Israel Hospital, followed by a year of res-
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idency at Bellevue Hospital in New York City. In 1939, Zoll returned to Beth Israel Hospital to study coronary artery diseases, but the outbreak of World War II interrupted his fellowship. Zoll went to the United Kingdom with the 160th U.S. Army Station Hospital, working as a cardiologist and a chief of medicine. Zoll returned to Boston in 1945 and started to research how to develop a technique for pacing the heart through the intact chest during asystole. In a groundbreaking 1952 article in the prestigious New England Medical Journal, he described how he had successfully revived a 65-year-old man applying electrodes on his bare chest. Zoll’s discovery of the possibility to electrically stimulate a blocked heart to beat countered the previously lethal effects of cardiac standstill. By 1956, Zoll had refined the electrical technique to resuscitate a patient from cardiac arrest. Because such technique was more effective with a prompt recognition of an arrest, Zoll also developed a monitoring device to display heart activity. Through the 1950s, he was Chief of the Cardiac Clinic at Beth Israel Hospital. In the early 1960s, Zoll took his discoveries on how to electrically stimulate the heart a step farther. Together with his team, he developed pacemakers that could be implanted in the human body, thus providing long-term direct electrical stimulation of the heart. Zoll designed these pacemakers to prevent the seizures typical of Stokes-Adams disease, but their use has greatly expanded since their invention and they have now become a major form of cardiac therapy. In 1977, he became Clinical Professor of Medicine, Emeritus. Throughout the 1970s and 1980s, Zoll’s contribution to the reduction of mortality due to heart diseases earned him many important scientific awards. Zoll died on January 5, 1999, in Chestnut Hill, near Boston. SEE ALSO: Arrhythmia; Heart Diseases. BIBLIOGRAPHY. Pierre J. Birkui, Jacques A. Trigano, and
Paul M. Zoll, eds., Noninvasive Transcutaneous Cardiac Pacing (Blackwell Publishers 1992); “Paul Maurice Zoll: Faculty of Medicine, Memorial Minute,” Harvard University Gazette (April 19, 2001), www.hno.harvard.edu/gazette/2001/04.19/12-zoll.html (cited May 2007). Luca Prono Independent Scholar
Resource Guide BOOKS Abraham, J. Science, Politics and the Pharmaceutical Industry (UCL Press, 1995) Abraham, J. and Lewis, G. Regulating Medicines in Europe (Routledge, 2000) Alberts, David S. and Hess, Lisa M. Fundamentals of Cancer Prevention (Springer, 2005) Aron, Joan L. and Patz, Jonathan A. Ecosystem Change and Public Health: A Global Perspective (Johns Hopkins University Press, 2001) Athanasou, Nicholas. Pathological Basis of Orthopaedic & Rheumatic Disease (Arnold, 2001) Basch, Paul. Textbook of International Health (Oxford University Press, 1999) Beck, A.T. Cognitive Theory and The Emotional Disorders. (Penguin Books, 1979) Bickley, Lynn S. Bates’ Guide to Physical Examination and History Taking, Eighth Edition (Lippincott Williams and Wilkins, 2003) Braunwald, Eugene, et al. Harrison’s Principles of Internal Medicine, Fifteenth Edition (McGraw- Hill, 2001) Buckingham, Robert. A Primer on International Health (Benjamin Cummings, 2000) Burbank, Patricia M. Vulnerable Older Adults: Health Care Needs and Interventions (Springer, 2006) Coope, John. Doctor Chekhov: A Study in Literature and Medicine (Cross Publishing, 1997)
Cooper, B.S. and How, S. Medicare’s Future: Current Picture, Trends, and Medicare Prescription Drug Improvement & Modernization Act of 2003 (The Commonwealth Fund, 2004) Debre, Patrice. Louis Pasteur (Flammarion, 1994) Dipiro, Joseph T., et al. Pharmacotherapy: A Pathophysiologic Approach (McGraw-Hill, 2005) Dowell, Scott F. and Levitt, Alexandra M. Protecting the Nation’s Health in an Era of Globalization: CDC’s Global Infectious Disease Strategy (HHS and CDC, 2002) Evans, Audrey E. Advances in Neuroblastoma Research (Raven Press, 1980) Fort, Meredith, et al. Sickness and Wealth: The Corporate Assault on Global Health (Sound End Press, 2004) Foster, K. Wade and Elmets, Craig A. Sunburn (Conn’s Current Therapy, 2006) Framer, Paul. Infections and Inequalities: The Modern Plagues (University of California Press, 2001) French, H.E. The Productivity of Health Care and Pharmaceuticals: An International Comparison (AEI Press, 1999) Global Health Watch. Global Health Watch 2005-06: An Alternative World Health Report (Zed, 2005) Greenberg, Mark S. Handbook of Neurosurgery, Fifth Edition (Thieme, 2001) Gunn, S.W.A., et al. Understanding the Global Dimensions of Health (Springer, 2005) 1779
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Harrison, A. Getting the Right Medicine? (King’s Fund, 2003) Henderson, J.W. Health Economics and Policy (South-Western College Pub., 1999) Hennig, Willi. Phylogenetic Systematics (University of Illinois Press, 1966) Hirshkowitz, Max and Smith, Patricia B. Sleep Disorders for Dummies (Wiley, 2007) Hodges, L. Environmental Pollution (Holt, Rinehart and Winston, 1973) Hoffman G.F., et al. Inherited Metabolic Diseases (Lippincott Williams & Wilkins, 2002) House, William F., et al. Acoustic Tumors: Diagnosis and Management (Singular, 1997) Kasmauski, Karen. Impact: On the Frontlines of Global Health (National Geographic, 2003) Kasper, Dennis L. Harrison’s Principle’s of Internal Medicine (McGraw-Hill Inc., 2005) Kinder, Molly and Levine, Ruth. Millions Saved: Proven Successes in Global Health (Center for Global Development, 2004) Klug, William S. and Cummings, Michael R. Concepts of Genetics (Prentice Hall, 2002) Koop, C. Everett, et al. Critical Issues in Global Health (Jossey-Bass, 2002) Krapp, Kristine and Wilson, Jeffrey. The Gale Encyclopedia of Children’s Health: Infancy through Adolescence (Thomas Gale, 2005) Kufe, Donald. Cancer Medicine, Sixth Edition (Hamilton, 2003) Kumar, Vinay, et al. Pathologic Basis of Disease (Elsevier Saunders, 2005) Lang, Laura. GIS for Health Organizations (ESRI Press, 2000) Last, John. A Dictionary of Epidemiology (Oxford University Press, 2000) Lipsky, Martins S. American Medical Association: Concise Medical Encyclopedia (Random House Reference, 2007) Lopez, Alan D., et al. Global Burden of Disease and Risk Factors (World Bank Publications, 2006) MacKay, Ian R. and Rose, Noel Richard. The Autoimmune Diseases, Fourth Edition (St. Louis, 2006) Malt, Robert A. The Practice of Surgery (W.B. Saunders, 1993) Meade, Melinda S. and Earickson, Robert J. Medical Geography, Second Edition (Guilford Press, 2005) Merson, Michael. International Public Health (Jones and Bartlett, 2005)
Meyer, Jerrold S. and Quenzer, Linda F. Psychopharmacology: Drugs, the Brain, and Behavior (Sinauer & Associates, 2004) Moeller, D.W. Environmental Health (Harvard University Press, 1992) Monagle, John F. Health Care Ethics: Issues for the 21st Century (Aspen, 1998) Murray, J.L. and Lopes, A.D. The Global Burden of Disease (Harvard University Press, 1996) Nadakavukaren, Anne. Our Global Environment: A Health Perspective, Sixth Edition (Waveland Press, 2005) National Bioethics Advisory Commission, Ethical Issues in Human Stem Cell Research, Volume 1: Report and Recommendations (National Bioethics Advisory Commission, 1999) Nussbaum, R.L., et al. Thompson & Thompson: Genetics in Medicine, Sixth Edition (Saunders, 2004) O’Neil, Edward. A Practical Guide to the Global Health Service (American Medical Association, 2006) Payne-James, Jason, et al. Forensic Medicine: Clinical and Pathological Aspects (Greenwich Medical Media, 2003) Pilling, Lucille B. The Global Health Alliance: Lessons Learned (Unlimited Publishing, 2006) Prados, Michael. Brain Cancer (B.C. Decker, 2002) Pratt, Carlos W. PsychiatricRehabilitation (Academic Press, 2002) Riddle, John M. Eve’s Herbs: A History of Contraception and Abortion in the West (Harvard University Press, 1999) Rockefeller, David, et al. Global Health Leadership and Management (Jossey-Bass, 2005) Rosenberg, R.N., et al. The Molecular and Genetic Basis of Neurological Disease, Second Edition (Butterworth-Heinemann, 1997) Rothman, Kenneth and Greenland, Sander. Modern Epidemiology (Lippincott Williams & Wilkins, 1998) Sackett, David, Evidence-based Medicine: How to Practice and Teach EBM (Churchill Livingstone, 1988) Sallis, Robert and Massimino, Ferdy. Essentials of Sports Medicine (Mosby, 1997) Schumacher Jr., H. Ralph. Primer of Rheumatic Diseases (Arthritis Foundation, 1993) Shalley, Halie. Williams Obstetrics: Breech Presentation and Delivery (McGraw-Hill, 2006)
Silverstein, Arthur. A History of Immunology (Academic Press, 1989) Skinner, B.F. About Behaviorism (Alfred A. Knopf, 1974) Stekel, Dov. Microarray Bioinformatics (Cambridge University Press, 2003) Walkup JT, et al. Tourette Syndrome (Lippincoot Williams and Wilkins, 2006) Wanjek, C. Bad Medicine: Misconceptions and Misuses Revealed, from Distance Healing to Vitamin O (John Wiley, 2002) Weinberg, Robert A. Racing to the Beginning of the Road: The Search for the Original Cancer (Harmony Books, 1996) Wermuth, Laurie. Global Inequality and Human Needs: Health and Illness in an Increasingly Unequal World (Allyn and Bacon, 2003) Werner, David. Where There Is No Doctor: A Village Health Care Handbook (Hesperian Foundation, 2006) Wolinsky, Howard and Brune, Tom. The Serpent on the Staff: The Unhealthy Politics of the American Medical Association (Putnam, 1994) World Health Organization, Unsafe Abortion: Global and Regional Estimates of the Incidence of Unsafe Abortion and Associated Mortality in 2000 (World Health Organization, 2004) Zemlin, Willard R. Speech and Hearing Science: Anatomy and Physiology, Fourth Edition (Prentice Hall 1998) Zipperer, Lorri A. The Health Care Almanac: A Resource Guide to the Medical Field (American Medical Association, 1995) JOURNALS American Family Physician American Journal of Ophthalmology American Journal of Psychology American Journal of Public Health American Journal of Tropical Medicine and Hygiene Annals of the New York Academy of Sciences British Medical Journal British Journal of General Practice International Journal of Developmental Biology International Journal of Epidemiology Journal of Allergy and Clinical Immunology Journal of Clinical Infectious Diseases Journal of Clinical Psychiatry Journal of Health Psychology Journal of Holistic Nursing Journal of Molecular Evolution
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Journal of Obstetrics and Gynecology Journal of Pediatric Neurology Journal of Perinatology Journal of Psychosomatic Research Journal of the American Medical Association Journal of the American Geriatrics Society Journal of Youth and Adolescence New England Journal of Medicine Psychiatric Quarterly The European Journal of Contraception and Reproductive Health Care INTERNET www.aapm.org American Association of Physicists in Medicine www.heart.org American Heart Association www.ama-assn.org American Medical Association www.redcross.org American Red Cross www.asaging.org American Society on Aging www.telepathology.upmc.edu American Telemedicine Association www.cdc.gov Centers for Disease Control and Prevention www.emedicine.com eMedicine World Health Library www.marchofdimes.com March of Dimes www.mrc.ac.uk Medical Research Council www.nawho.org National Asian Women’s Health Organization www.natlbcc.org National Breast Cancer Coalition www.cancer.gov National Cancer Institute www.ninds.nih.gov National Institute of Neurological Disorders and Stroke www.nmha.org National Mental Health Association (NMHA) www.immunizationinfo.org National Network for Immunization Information www.oif.org Osteogenesis Imperfecta Foundation www.paho.org Pan American Health Organization
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www.scoliosis-world.com Scoliosis World www.sophe.org Society for Public Health Education www.ninds.nih.gov Spinal Cord Injury Information Page www.foodallergy.org The Food Allergy & Anaphylaxis Network www.nlm.nih.gov The National Library of Medicine
www.channing.harvard.edu/nhs/ The Nurses Health Study Website www.unitedhealthfoundation.org United Health Foundation www.unos.org United Network for Organ Sharing www.dignityindying.org Voluntary Euthanasia Society www.who.org World Health Organization
Glossary
abdomen: area between the chest and the hips that contains the stomach, small intestine, large intestine, liver, gallbladder, pancreas, and spleen. abdominal bracing: technique of tensing the stomach muscles to support the spine. abdominal hysterectomy: a procedure in which the uterus is removed through the abdomen via a surgical incision. abdominoplasty (also called “tummy tuck.”): a procedure that minimizes the abdominal area. In abdominoplasty, the surgeon makes a long incision from one side of the hipbone to the other. Excess fat and skin are surgically removed from the middle and lower abdomen and the muscles of the abdomen wall are tightened. abdominoscopy: a type of surgery using a laparoscope (a long, thin tube with a camera lens attached), which is inserted into one or more small incisions, to examine the abdominal cavity. ablation: elimination or removal. ablative therapy: treatment that removes or destroys the function of an organ, such as surgical removal of an organ or some types of chemotherapy. abortion: medical termination of a pregnancy before the fetus has developed enough to survive outside the uterus. abscess: hole filled with pus that forms as a result of a local infection.
absorption: the process by which nutrients from food move from the small intestine into the body cells. abutment teeth: the surrounding teeth of each side of the gap where teeth are missing. accessory digestive organs: organs that help with digestion but are not part of the digestive tract. These organs include the tongue, pancreas, liver, gallbladder, and glands in the mouth that make saliva. accessory movement: joint movements that cannot be performed voluntarily or in isolation by the patient. accommodation: the ability of the eye to focus. ACE (angiotensin-converting enzyme) inhibitor: a medication that lowers blood pressure. acetaminophen: a pain-relieving and fever-reducing drug found in many over-the-counter medications (i.e., Tylenol, Tempra, or Feverall). acetylcholine: a chemical in the brain that acts as a neurotransmitter. achalasia: a rare disorder of the esophagus in which the muscle at the end of the esophagus does not relax enough for the passage to open properly. Achilles tendonitis: Inflammation of the Achilles tendon. acne: a chronic disorder of the hair follicles and sebaceous glands. Acne is characterized by black heads, pimple outbreaks, cysts, infected abscesses, and (sometimes) scarring. 1783
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acoustic neurinoma: a tumor, usually benign, which develops on the hearing and balance nerves and can cause gradual hearing loss, tinnitus, and dizziness. acquired deafness: loss of hearing that occurs or develops over the course of a lifetime; deafness not present at birth. acquired immune deficiency syndrome (AIDS): a disease caused by the human immunodeficiency virus (HIV), which kills or impairs cells of the immune system and progressively destroys the body’s ability to fight infections and certain cancers. HIV is most commonly spread by sexual contact with an infected partner. The term AIDS applies to the most advanced stages of an HIV infection. acromegaly: excessive growth due to the production of excessive growth hormone by the pituitary gland. acromion: the roof, or highest point, of the shoulder that is formed by a part of the scapula, or shoulder blade. actinic keratosis: a precancerous condition of thick, scaly patches of skin. action tremor: a tremor that increases when the hand is moving voluntarily. activated charcoal: an over-the-counter product that may help relieve intestinal gas. activities of daily living (ADLs): personal care activities necessary for everyday living, such as eating, bathing, grooming, dressing, and toileting; a term often used by healthcare professionals to assess the need and/or type of care a person may require. acupuncture points: anatomic points on the body used in acupuncture. acute: severe; sharp; begins quickly. acute appendicitis: acute inflammation of the appendix due to infection. acute lymphocytic leukemia (ALL): a rapidly progressing cancer of the blood in which too many immature (not fully formed) lymphocytes, a type of white blood cell, are found in the bone marrow, blood, spleen, liver, and other organs. acute myelogenous leukemia (AML): a rapidly progressing cancer of the blood in which too many immature (not fully formed) granulocytes, a type of white blood cell, are found in the bone marrow and blood. adenocarcinoma: cancerous tumors of the glands, such as in the ducts or lobules of the breast. adenoma: benign growths which often appear on glands or in glandular tissue. adhesion: a band of scar tissue that joins normally separated internal body structures, most often after surgery, inflammation, or injury in the area.
adhesions: abnormal bands of tissue that grow between joint surfaces, restricting motion. adjuvant treatment: treatment that is added to other therapies to increase effectiveness. adrenal cortex: outer portion of the adrenal gland that secretes hormones that are vital to the body. adrenal glands: two small glands located on top of the kidneys that secrete hormones. adrenaline (also called epinephrine): one of two chemicals (the other is norepinephrine) released by the adrenal gland that increases the speed and force of heart beats. It dilates the airways to improve breathing and narrows blood vessels in the skin and intestine so that an increased flow of blood reaches the muscles and allows them to cope with the demands of exercise. advance directives: legal documents, such as living wills and durable powers of attorney for healthcare decisions, stating a patient’s medical preferences in the event the patient should become incapable of voicing his/her opinion. advanced cancer: stage of cancer in which the disease has spread from the primary site to other parts of the body. aerophagia: condition that occurs when a person swallows too much air; causes gas and frequent belching. African trypanosomiasis (also called “African sleeping sickness.”): a systemic disease caused by parasite of the Trypanosoma brucei family, and transmitted by the bite of the tsetse fly. There is West African trypanosomiasis and East African trypanosomiasis, referring to the areas in Africa where they are found. ageusia: loss of the sense of taste. agitation: a non-specific symptom of one or more physical or psychological processes in which vocal or motor behavior (screaming, shouting, complaining, moaning, cursing, pacing, fidgeting, wandering) pose risk or discomfort, become disruptive or unsafe, or interfere with the delivery of care in a particular environment. agonist: a drug that increases neurotransmitter activity by stimulating the dopamine receptors directly. agoraphobia: a Greek word that literally means “fear of the marketplace.” This anxiety disorder involves the fear of experiencing a panic attack in a place or situation from which escape may be difficult or embarrassing. air bags: safety devices installed in most newer vehicles that inflate to protect the driver and/or passenger in certain collisions.
air pollution: the presence of noxious substances in the air that we breathe. akinesia: no movement. alactasia: inherited condition that causes a lack of the enzyme needed to digest milk sugar. albinism: a rare, inherited disorder characterized by a total or partial lack of melanin (skin pigment) in the skin. albumin: a protein found in blood plasma and urine, which can be a sign of kidney disease. alcohol-induced chronic hepatitis: one type of hepatitis; continued liver damage throughout the liver from heavy alcohol consumption. aldosterone: a hormone secreted by the adrenal cortex that controls sodium and potassium in the blood. alimentary canal: gastrointestinal (GI) tract. allergen: a substance that triggers an allergic reaction. allergic conjunctivitis: red, itchy, watery eyes; a result of an exposure to an allergen or an irritant. allergy: an acquired, abnormal immune response to a substance that can cause a broad range of inflammatory reactions. allodynia: pain due to a stimulus that does not normally provoke pain. allogeneic bone marrow transplantation: a procedure in which a person receives stem cells from a compatible donor. allogeneic transplant: the transfer of bone marrow from one person to another. alopecia: a partial or complete loss of hair that may result from radiation therapy to the head, chemotherapy, skin disease, drug therapy, and natural causes. alpha thalassemia: an inherited blood disorder affecting the alpha chains of the hemoglobin molecule. alpha-fetoprotein (AFP): a protein produced by a developing fetus that is present in amniotic fluid and, in smaller amounts, in a pregnant woman’s blood. Abnormal levels of AFP found in a blood test between the 15th and 18th weeks of pregnancy can indicate abnormalities in the fetus. Alport’s syndrome: A hereditary condition characterized by kidney disease, sensorineural hearing loss, and some difficulties with eye defects. alternative medicine: any form of therapy used alone, without recommended standard/conventional treatment. alveolus: air sac where gas exchange takes place. Alzheimer’s disease: A progressive, degenerative disease that occurs in the brain and results in impaired memory, thinking, and behavior.
Glossary
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amblyopia: sometimes called “lazy eye,” is the reduction or dimming of vision in an eye that appears to be normal. amebiasis: acute or chronic infection; symptoms vary from mild diarrhea to frequent, watery diarrhea and loss of water and fluids in the body. amenorrhea: absence or cessation of menstrual periods. amenorrhea, primary: from the beginning and lifelong; menstruation never begins at puberty. amenorrhea, secondary: due to some physical cause and usually of later onset; a condition in which menstrual periods which were at one time normal and regular become increasing abnormal and irregular or absent. American Cancer Society (ACS): An organization that supports research, produces educational materials and programs, and offers many other services to cancer patients and their families. American National Standards Institute (ANSI): An organization that evaluates and approves helmets. American Sign Language (ASL): Manual (hand) language with its own syntax and grammar used primarily by people who are deaf. American Society for Testing and Materials (ASTM): An organization that evaluates and approves helmets. amniocentesis: a test performed to determine chromosomal and genetic disorders and certain birth defects. The test involves inserting a needle through the abdominal and uterine wall into the amniotic sac to retrieve a sample of amniotic fluid. amniotic fluid: clear liquid that surrounds and protects the fetus throughout pregnancy. amniotic sac: a thin-walled sac that surrounds the fetus during pregnancy. The sac is filled with amniotic fluid: liquid made by the fetus and the amnion (the membrane that covers the fetal side of the placenta) which protects the fetus from injury and helps to regulate the temperature of the fetus. Amsler grid: A chart featuring horizontal and vertical lines used to test vision. amyloidosis: a rare disease which causes the buildup of amyloid, a protein and starch, in tissues and organs. amyotrophic lateral sclerosis (also called ALS or Lou Gehrig’s disease): a terminal, neurological disorder characterized by progressive degeneration of motor cells in the spinal cord and brain. anal fissure: small tear in the anus that may cause itching, pain, or bleeding.
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Glossary
anal fistula: channel that develops between the anus and the skin. Most fistulas are the result of an abscess (infection) that spreads to the skin. analgesia: absence of pain in response to stimulation that would normally be painful. analgesic: any drug intended to alleviate pain. anaphylaxis (also called anaphylactic shock): a sudden, severe, potentially life-threatening allergic reaction caused by food allergy, insect stings, or medications. Symptoms can include hives, swelling (especially of the lips and face), difficulty breathing (either because of swelling in the throat or an asthmatic reaction), vomiting, diarrhea, cramping, and a fall in blood pressure. anastomosis: operation to connect two body parts. An example is an operation in which a part of the colon is removed and the two remaining ends are rejoined. androgen hormone: a hormone that stimulates activity of male sex organs, and encourages development of male sex characteristics. anemia: blood disorder caused by a deficiency of red blood cells or hemoglobin (the oxygen-carrying protein in red blood cells). anesthesia: lack of normal sensation, especially the awareness of pain, which may be brought on by anesthetic drugs. General anesthesia causes loss of consciousness; local or regional anesthesia causes loss of feeling only to a specified area. anesthetics: medications that cause loss of sensation to pain or awareness. aneurysm: a weakened, pouched area on the wall of an artery. angina pectoris (also called angina): recurring chest pain or discomfort that happens when some part of the heart does not receive enough blood. angiodysplasia: abnormal or enlarged blood vessels in the gastrointestinal tract. angiogenesis: the formation of new blood vessels. angiogenesis inhibitor: a chemical which signals the process of angiogenesis to stop. angiography: an x-ray that uses dye injected into arteries so that blood circulation can be studied. angioma: a benign tumor in the skin, which is made up of blood or lymph vessels. angioplasty: the use of a small balloon on the tip of a catheter inserted into a blood vessel to open up an area of blockage inside the vessel. ankle sprain: over-stretched lateral (outside) ligament of the ankle joint. ankylosing spondylitis: disease that affects the spine, causing the bones of the spine to grow together.
anomaly: a health problem or feature not normally present in a healthy individual; a deviation from the normal. anorexia nervosa (also called anorexia): an eating disorder characterized by low body weight (less than 85 percent of normal weight for height and age), a distorted body image, and an intense fear of gaining weight. anoscopy: test to look for fissures, fistulae, and hemorrhoids using a special instrument, called an anoscope, to look into the anus. anosmia: absence of the sense of smell. anovulation: failure of the ovaries to produce or release mature eggs. antacids: medications that balance acids and gas in the stomach. anterior chamber: the front section of the eye’s interior where aqueous humor flows in and out of providing nourishment to the eye and surrounding tissues. anterior cruciate ligament (ACL): the ligament, located in the center of the knee, that controls rotation and forward movement of the tibia (shin bone). anterolateral shin splint: a type of shin splint that affects the front and outer part of the muscles of the shin and is caused by a congenital (present at birth) imbalance in the size of opposite muscles. antibiotic: a chemical substance produced by living organisms or synthesized (created) in laboratories for the purpose of killing other organisms that cause disease. antibodies: proteins produced by the immune system to fight specific bacteria, viruses, or other antigens. antibody: a special protein produced by the body’s immune system that recognizes and helps fight infectious agents and other foreign substances that invade the body. anticholinergics: medications that calm muscle spasms in the intestine. anticipatory grief: the deep emotional distress that occurs when someone has a prolonged illness and death is expected often by the patient as well as the family. Anticipatory grief can be just as painful and stressful as the actual death of the person. anticoagulant: a medication that keeps blood from clotting. antidiarrheals: medications that help control diarrhea. antiemetics: medications that prevent and control nausea and vomiting. antiestrogen: substance (i.e., tamoxifen) that blocks the effects of estrogen on tumors.
antigen: a substance that can trigger an immune response causing the production of antibodies as part of the body’s defense against infection and disease. antihistamine: a medication that blocks the effects of histamine, a chemical released in body fluids during an allergic reaction. antihypertensive: a medication or other therapy that lowers blood pressure. anti-inflammatory: medications that reduce the symptoms and signs of inflammation. antioxidants: compounds that protect against cell damage inflicted by molecules, called oxygen-free radicals, which are a major cause of disease and aging. antisocial personality disorder: persons with this disorder characteristically disregard the feelings, property, authority, and respect of others for their own personal gain. This may include violent or aggressive acts involving or targeting other individuals, without a sense or remorse or guilt for any of their destructive actions. antispasmodics: medications that help reduce or stop muscle spasms in the intestines. antivenin: an antidote to snake venom used to treat serious snake bites. Antivenin is derived from antibodies created in a horse’s blood serum when the animal is injected with snake venom. Because antivenin is obtained from horses, snake bite victims sensitive to horse products must be carefully managed. antrectomy: operation to remove the upper portion of the stomach, called the antrum, to help reduce the amount of stomach acid. anus: opening at the end of the digestive tract where the bowel contents leave the body. aorta: blood vessel that delivers oxygen-rich blood from the left ventricle to the body; it is the largest blood vessel in the body. aortic valve: the valve that regulates blood flow from the heart into the aorta. Apert syndrome: A craniofacial abnormality characterized by an abnormal head shape, small upper jaw, and fusion of the fingers and toes. apex: top portion of the upper lobes of the lungs. Apgar test: A scoring system to evaluate the condition of a newborn immediately after birth. aphasia: total or partial loss of ability to use or understand language; usually caused by stroke, brain disease, or injury. apheresis: a procedure in which blood is removed from a patient, certain fluid and cellular elements are removed, and the blood is then infused back into the patient.
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aphonia: complete loss of voice. aplastic anemia: one type of anemia that occurs when the bone marrow produces too few of all three types of blood cells: red blood cells, white blood cells, and platelets. appendectomy: the surgical removal of the appendix (to treat acute appendicitis) appendicitis: inflammation and reddening of the appendix caused by infection, scarring, or blockage. appendix: a small pouch, attached to the first part of the large intestine, whose function in the body is unknown. apraxia: inability to make a voluntary movement in spite of being able to demonstrate normal muscle function. areola: dark area of skin that surrounds the nipple of the breast. arrhythmia (also called dysrhythmia): an abnormal heartbeat. arteriogram (also called an angiogram): an x-ray of the arteries to detect blockage or narrowing of the vessels. arterioles: small branches of arteries. arteriosclerosis (also called “hardening of the arteries”): a variety of conditions caused by fatty or calcium deposits in the artery walls causing them to thicken. artery: a blood vessel that carries oxygenated blood away from the heart to the body. arthralgia: pain in a joint, usually due to arthritis or arthropathy. arthritis: inflammation of a joint, usually accompanied by pain, swelling, and sometimes a change in structure. arthrogram: an x-ray to view bone structures following an injection of a contrast fluid into a joint area. When the fluid leaks into an area that it does not belong, disease or injury may be considered, as a leak would provide evidence of a tear, opening, or blockage. arthroplasty: total joint replacement. arthroscopy: a minimally-invasive diagnostic and treatment procedure used for conditions of a joint. This procedure uses a small, lighted, optic tube (arthroscope) which is inserted into the joint through a small incision in the joint. Images of the inside of the joint are projected onto a screen; used to evaluate any degenerative and/or arthritic changes in the joint; to detect bone diseases and tumors; to determine the cause of bone pain and inflammation. articular cartilage: covers the ends of bones and allows the distribution of compressive loads over the
1788
Glossary
cross section of bones; provides frictionless and wearresistant surface for joint movement. articulation disorder: inability to correctly produce speech sounds (phonemes) because of imprecise placement, timing, pressure, speed, or flow of movement of the lips, tongue, or throat. artificial insemination: a procedure that involves the placement of relatively large numbers of healthy sperm either at the entrance of the cervix or into a women’s uterus, bypassing the cervix, to have direct access to the fallopian tubes. artificial ventilation: the process of supporting breathing by manual or mechanical means when normal breathing is inefficient or has stopped. ascending colon: part of the colon on the right side of the abdomen. ascites: fluid build-up in the abdominal cavity. assisted living facility (ALF): an out-of-home care option for elderly persons who continue to lead relatively active, healthy, and independent lives. Most ALFs feature apartment-style living and many services for the elderly. assisted reproductive technology (ART): medical procedures, such as intrauterine insemination, that are performed to help infertile couples conceive. assistive devices: technical tools and devices such as alphabet boards, text telephones, or text-to-speech conversion software used to assist people with physical or emotional disorders in performing certain actions, tasks, and activities. asthma: a chronic, inflammatory lung disease characterized by recurrent breathing problems and is usually triggered by allergens. Infection, exercise, cold air, and other factors may also be allergic triggers. astigmatism: a vision problem that results in blurred images. asymmetry: lacking symmetry; parts of the body are unequal in shape or size. asymptomatic: to be without symptoms of disease. ataxia: loss of balance. atherectomy: a non-surgical procedure that involves removing plaque from the walls of arteries with a rotating blade. atherosclerosis: a type of arteriosclerosis caused by a build-up of plaque in the inner lining of an artery. athetosis: slow, involuntary movements of the hands and feet. atonic colon (also called lazy colon): lack of normal muscle tone or strength in the colon caused by the overuse of laxatives or by Hirschsprung’s disease; may result in chronic constipation.
atopic dermatitis (also called eczema): a skin disorder that is characterized by itching, scaling, and thickening of the skin; usually located on the face, elbows, knees, and arms. atresia: lack of a normal opening from the esophagus, intestines, or the anus. atrioventricular (AV) node: a cluster of cells between the atria and ventricles that regulate the electrical current. atrioventricular block: an interruption of the electrical signal between the atria and the ventricles. atrium: one of two upper chambers in the heart. atrophic gastritis: chronic inflammation of the stomach lining that causes the breakdown of the mucous membranes of the stomach. atrophic skin: skin that is thin and wrinkled. atrophy: wasting away of a body part or tissue. attention-deficit/hyperactivity disorder (ADHD): a syndrome (a group of symptoms or signs) that is usually characterized by serious and persistent difficulties, resulting in inattentiveness or distractibility, impulsivity, and hyperactivity. atypical: not usual; often refers to the appearance of precancerous or cancerous cells. audiologist: a healthcare professional trained to identify and measure hearing impairments and related disorders using a variety of tests and procedures. auditory brainstem response (ABR) test: used to test hearing in infants and young children, or to test for brain functioning in unresponsive patients. auditory nerve: eighth cranial nerve that connects the inner ear to the brainstem. auditory perception: ability to identify, interpret, and attach meaning to sound. auditory prosthesis: device that substitutes or enhances the ability to hear. augmentative devices: tools that help individuals with limited or absent speech to communicate. aural rehabilitation: techniques used with people who are hearing impaired to improve ability to speak and to communicate. autism: brain disorder that begins in early childhood and persists throughout adulthood; affects three crucial areas of development: communication, social interaction, and creative or imaginative play. autoimmune hepatitis: liver disease caused when the body’s immune system destroys liver cells for no known reason. autoimmune process: a process in which the body’s immune system attacks and destroys body tissue that it mistakes for foreign matter.
autologous bone marrow transplantation: a procedure in which a patient’s own bone marrow is removed, treated with anticancer drugs or radiation, then returned to the patient. autologous tissue breast reconstruction: the use of the patient’s own tissues to reconstruct a new breast mound. The common technique is the TRAM (transverse rectus abdominous muscle) flap. A TRAM flap involves removing an area of fat, skin, and muscle from the abdomen and stitching it in place to the mastectomy wound. autopsy: examination of a body after death. Autopsies are performed to determine cause of death, or to verify a diagnosis. autosomal recessive inheritance: a gene on one of the first 22 pairs of chromosomes, which, when present in two copies, causes a trait or disease to be expressed. avascular necrosis: death of tissue due to depletion of blood supply. avoidant personality disorder: persons with this disorder are hypersensitive to rejection and thus, avoid situations with any potential for conflict. This reaction is fear-driven, however, persons with avoidant personality disorder become disturbed by their own social isolation, withdrawal, and inability to form close, interpersonal relationships. avulsion: when a muscle is forcefully stretched beyond its freely-available range of motion, or when it meets a sudden unexpected resistance while contracting forcefully. axilla: armpit. axillary dissection: a surgical procedure in which the lymph nodes in the armpit (axillary nodes) are removed and a microscopic examination is performed. axon: the long, hair-like extension of a nerve cell that carries a message to the next nerve cell. bacteremia: the presence of bacteria in the bloodstream. balance: biological system that enables individuals to know where their bodies are in the environment and to maintain a desired position; normal balance depends on information from the labyrinth in the inner ear, and from other senses such as sight and touch, as well as from muscle movement. balance disorder: disruption in the labyrinth, the inner ear organ that controls the balance system allowing individuals to know where their bodies are in the environment. balloon urethroplasty: a thin tube with a balloon is inserted into the opening of the penis and guided to the narrowed portion of the urethra. The balloon is
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then inflated to widen the urethra and ease the flow of urine. barium: a metallic, chemical, chalky, liquid used to coat the inside of organs so that they will show up on an x-ray. barium enema (also called lower GI, or gastrointestinal, series): a procedure that examines the rectum, large intestine, and lower part of the small intestine. A fluid called barium (a metallic, chemical, chalky, liquid used to coat the inside of organs so that they will show up on an x-ray) is given into the rectum as an enema. barium beefsteak meal: during this test, the patient eats a meal containing barium, allowing the radiologist to watch the stomach as it digests the meal. The amount of time it takes for the barium meal to be digested and leave the stomach gives the physician an idea of how well the stomach is working and helps to detect emptying problems that may not show up on the liquid barium x-ray. barium swallow: upper gastrointestinal (GI) series. barotrauma: injury to the middle ear caused by a reduction of air pressure. basal body temperature: temperature of a person’s body taken first thing in the morning after several hours of sleep and before any activity, including getting out of bed or talking; often charted to determine the time of ovulation. basal cell carcinoma: the most common form of skin cancer; characterized by small, shiny, raised bumps on the skin that may bleed. basal cells: a type of cells found in the outer layer of skin. Basal cells are responsible for producing the squamous cells in the skin. basal ganglia: several large clusters of nerve cells, including the striatum and the substantia nigra, deep in the brain below the cerebral hemispheres. basal metabolic rate (BMR): a measurement of energy required to keep the body functioning at rest. Measured in calories, metabolic rates increase with exertion, stress, fear, and illness. base: bottom portion of lower lobes of the lungs, located just above the diaphragm. bed sores: ulcers that occur on areas of the skin that are under pressure from lying in bed, sitting in wheelchairs, wearing a cast, or being immobile for a long period of time. belching (also called burping): noisy release of gas from the stomach through the mouth. Bell’s palsy: An unexplained episode of facial muscle weakness or paralysis that begins suddenly and steadily worsens.
1790
Glossary
benign: non-cancerous. benign paroxysmal positional vertigo (BPPV): balance disorder that results in a sudden onset of dizziness, spinning, or vertigo that occurs when suddenly moving the head from one position to another. benign prostatic hyperplasia (also called BPH or benign prostatic hypertrophy): an enlargement of the prostate caused by disease or inflammation. It is not cancer, but its symptoms are often similar to those of prostate cancer. benign tumor: an abnormal growth that is not cancer and does not spread to other areas of the body. bereavement: to be in a sad or lonely state due to a loss or death. Bernstein test: Test to find out if heartburn is caused by acid in the esophagus; involves dripping a mild acid, similar to stomach acid, through a tube placed in the esophagus. beta blocker: an antihypertensive medication that limits the activity of epinephrine (a hormone that increases blood pressure). beta cells: cells that make insulin; found in areas of the pancreas called the islets of Langerhans. beta thalassemia: an inherited blood disorder affecting the beta chains of the hemoglobin molecule. bezoar: ball of food, mucus, vegetable fiber, hair, or other material that cannot be digested in the stomach, which can cause blockage, ulcers, and bleeding. biarthrodial muscles: muscles that span over two joints and have a function over those joints. bilateral: affecting both sides of the body. For example, bilateral breast cancer is cancer occurring in both breasts at the same time. bile: yellowish-brown or green fluid secreted by the liver that carries away waste and aids in the digestive process. bile acids: acids made by the liver that work with bile to break down fats. bile ducts: tubes that carry bile from the liver to the gallbladder for storage, and to the small intestine for use in digestion. biliary atresia: condition present from birth in which the bile ducts inside or outside the liver do not have normal openings. Bile becomes trapped in the liver, causing jaundice and cirrhosis. Without surgery, the condition may cause death. biliary stricture: narrowing of the biliary tract from scar tissue. The scar tissue may result from injury, disease, pancreatitis, infection, or gallstones. biliary tract (also called biliary system or biliary tree): gallbladder and the bile ducts.
bilirubin: a yellowish-green substance formed when hemoglobin breaks down. Bilirubin gives bile its color. Bilirubin is normally passed in stool. Too much bilirubin causes jaundice. binge eating disorder: an illness that resembles bulimia nervosa and is characterized by episodes of uncontrolled eating or bingeing. It differs from bulimia, however, because its sufferers do not purge their bodies of the excess food, via vomiting, laxative abuse, or diuretic abuse. bingeing: persons with bulimia nervosa and binge eating disorder engage in a destructive pattern of excessively overeating, called bingeing. binocular vision: the ability to use both eyes at once. biological therapy (also called immunotherapy, biotherapy, or biological response modifier therapy): uses the body’s immune system, either directly or indirectly, to fight cancer or to lessen side effects that may be caused by some cancer treatments. biopsy: a procedure performed to remove tissue or cells from the body for examination under a microscope. birthmark: abnormality of the skin that is present at birth or shortly afterward. bismuth subsalicylate: nonprescription medication used to treat diarrhea, heartburn, indigestion, and nausea; also part of the treatment for ulcers caused by the bacterium Helicobacter pylori. bladder: a triangular-shaped, hollow organ located in the lower abdomen that holds urine. It is held in place by ligaments that are attached to other organs and the pelvic bones. The bladder’s walls relax and expand to store urine, and contract and flatten to empty urine through the urethra. bladder instillation (also called a bladder wash or bath): a procedure in which the bladder is filled with a solution that is held for varying periods of time, from a few seconds to 15 minutes, before being drained through a catheter. blasts: immature blood cells. blepharoplasty (also called eyelid lift): a procedure in which the physician surgically removes excess fat, muscle, and skin from both the upper and lower eyelids to redefine the shape of the eye. blink rate: number of times per minute that the eyelid automatically closes: normally 10 to 30 per minute. blister: a raised area on the skin containing fluid. The fluid can be blood or serum, the clear liquid portion of the blood. bloating: fullness or swelling in the abdomen that often occurs after meals.
blood: the life-maintaining fluid which is made up of plasma, red blood cells (erythrocytes), white blood cells (leukocytes), and platelets; blood circulates through the body’s heart, arteries, veins, and capillaries; it carries away waste matter and carbon dioxide, and brings nourishment, electrolytes, hormones, vitamins, antibodies, heat, and oxygen to the tissues. blood banking: the process that takes place in the laboratory to ensure that donated blood, or blood products, are safe before they are used in blood transfusions and other medical procedures. Blood banking includes typing the blood for transfusion and testing for infectious diseases. blood clot: a gelled mass of blood tissue. blood glucose: the main sugar that the body makes from food; cells cannot use glucose without the help of insulin. blood plasma: the fluid part of blood that contains nutrients, glucose, proteins, minerals, enzymes, and other substances. blood pressure: pressure of blood against the walls of a blood vessel or heart chamber. blood pressure cuff: a device usually placed around the upper of the arm to measure blood pressure. blood-brain barrier: the protective membrane that separates circulating blood from brain cells. body mass index (BMI): the number, derived by using height and weight measurements, that gives a general indication if weight falls within a healthy range. boil: tender, swollen areas that form around hair follicles. bone: living tissue that makes up the body’s skeleton. bone density: measurement of the bone’s mass in relation to its volume. bone graft: a surgical procedure in which healthy bone is transplanted from another part of the patient’s body into the affected area. bone marrow: the soft, spongy tissue found inside bones. It is the medium for development and storage of about 95 percent of the body’s blood cells. bone marrow aspiration and biopsy: a procedure in which marrow is removed by aspiration or a needle biopsy under local anesthesia. In aspiration biopsy, a fluid specimen is removed from the bone marrow. In a needle biopsy, marrow cells (not fluid) are removed. These methods are often used together. bone marrow transplantation (BMT): the transfusion of healthy bone marrow cells into a person after their unhealthy bone marrow has been eliminated. bone scan: a nuclear imaging method to evaluate any degenerative and/or arthritic changes in the joints; to
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detect bone diseases and tumors; to determine the cause of bone pain or inflammation. booster seat: a seat to help raise a child in a vehicle so that the vehicle’s seat belt fits properly. borborygmi: rumbling sounds, or stomach “growling,” caused by gas moving through the intestines. borderline personality disorder: persons with this disorder present instability in their perceptions of themselves, and have difficulty maintaining stable relationships. Moods may also be inconsistent, but never neutral: their sense of reality is always seen in “black and white.” Persons with borderline personality disorder often feel as though they lacked a certain level of nurturing while growing up and, as a result, incessantly seek a higher level of caretaking from others as adults. This may be achieved through manipulation of others, leaving them often feeling empty, angry, and abandoned, which may lead to desperate and impulsive behavior. botanical: of plants and plant life. botulinum toxin type A: an injection of botulinum toxin into specific muscles will immobilize those muscles, preventing them from forming wrinkles and furrows. bowel: another word for the small and large intestines. bowel movement: body wastes passed through the rectum and anus. bowel prep: process used to clean the colon with enemas and a special drink; used before surgery of the colon, colonoscopy, or barium x-ray. brachytherapy: a type of radiation treatment in which the radioactive substance is placed inside the patient as close as possible to the area being treated. “brady-”: prefix meaning slow. bradycardia: abnormally slow heartbeat. bradykinesia: slowness of movement. bradyphrenia: slowness of thought processes. brain attack (also called stroke): occurs when brain cells die due to inadequate blood flow to the brain. brain scan: an imaging method used to find abnormalities in the brain, including brain cancer and cancer that has spread to the brain from other places in the body. brainstem implant: auditory prosthesis that bypasses the cochlea and auditory nerve to help individuals who cannot benefit from a cochlear implant because the auditory nerves are not working. Braxton-Hicks contractions: Painless contractions during pregnancy that help the uterus to grow and to help the blood circulate through the uterus.
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Glossary
BRCA1: gene, which, when altered, indicates an inherited susceptibility to breast cancer. BRCA2: gene, which, when altered, indicates an inherited susceptibility to breast and/or ovarian cancer. breast augmentation (also called augmentation mammaplasty): a procedure to reshape the breast in order to make it larger. The procedure can also be performed to reconstruct the breast following breast surgery. breast cancer: a cancerous tumor of the breast tissue. breast conservation therapy: surgery to remove a breast cancer and a small amount of benign tissue around the cancer without removing any other part of the breast. These procedures include a lumpectomy or a partial (segmental) mastectomy. breast implant: a manufactured, silicone, rubber sac which is filled with sterile saline or silicone gel that is used for either breast augmentation or reconstruction. breast reconstruction: surgery to rebuild a breast mound following a mastectomy. breast self-examination (BSE): a method in which a woman examines her breasts and the surrounding areas for lumps or changes. A BSE should be performed once a month, usually at a time other than the days before, during, or immediately after the menstrual period. breast specialist: term describing healthcare professionals who have a dedicated interest in breast health. breech birth: an abnormal delivery presentation in which the baby’s feet, knees, or buttocks come into the birth canal first, before the baby’s head. bromocriptine: a medication which acts on hormoneproducing tumors to suppress its hormone-producing function. bronchiolitis: inflammation that involves the bronchioles (small airways). bronchitis: an inflammation of the mucous membranes of the bronchial tubes, causing a persistent cough that produces considerable quantities of sputum (phlegm). bronchodilators: a group of medications that widen the airways in the lungs. bronchoscopy: the examination of the bronchi (the main airways of the lungs) using a flexible tube (bronchoscope). Bronchoscopy helps to evaluate and diagnose lung problems, assess blockages, obtain samples of tissue and/or fluid, and remove a foreign body. bronchus: any of the larger air passages that connect the trachea to the lungs.
bruise (also called contusion): a collection of blood due to broken blood vessels underneath the skin usually caused by trauma. A bruise causes discoloration and swelling in the area. bruxism: the condition of incessant grinding and clenching of the teeth, unintentionally, and at inappropriate times. Budd-Chiari syndrome: Rare liver disease in which the veins that drain blood from the liver are blocked or narrowed. bulimia nervosa (also known as bulimia): a disease in which there are uncontrolled episodes of overeating that are usually followed by purging (self-induced vomiting), misuse of laxatives, enemas, or medications that cause increased production of urine, fasting, and/ or excessive exercise to control weight. bulking agents: laxatives that make bowel movements soft and easy to pass. bundle-branch block: a condition in which the heart’s electrical system is unable to normally conduct the electrical signal. bunion: an inflammation and thickening of the bursa in the joint of the big toe. bursa: a sac filled with fluid located between a bone and a tendon or muscle. bursitis: repeated small stresses and overuse that cause the bursa to swell and become irritated. CA-125 test: Blood test to detect an elevated level of a protein antigen called CA-125, which may indicate ovarian cancer, among other disorders. calcification: the gathering of small deposits of calcium in the breast tissue, usually found by mammography. calcitonin: a hormone secreted by the thyroid gland which controls the levels of calcium and phosphorous in the blood. calcium: mineral that gives strength to bones and teeth and has an important role in muscle contraction, blood clotting, and nerve function. calcium channel blocker (or calcium blocker): a medication that lowers blood pressure. calculi: stones or solid lumps such as gallstones. calluses: thick, hardened areas of the skin, usually on the foot, caused by friction or pressure. CAM (Complementary & Alternative Medicine): Non-conventional approaches to healing, beyond traditional medicine. Complementary medicine is any form of therapy used in combination with other alternative treatments or standard/conventional medicine. Alternative medicine is used alone, without recommended standard treatment.
Campylobacter pylori: Original name for the bacterium that causes ulcers; new name is Helicobacter pylori. cancellous tissue: the sponge-like tissue inside bones. cancer: abnormal cells that divide without control, which can invade nearby tissues or spread through the bloodstream and lymphatic system to other parts of the body. candidiasis (also called yeast infection): a skin infection caused by yeast that can occur in the skin folds, navel, vagina, penis, mouth, and nail beds. capillaries: tiny blood vessels between arteries and veins that distribute oxygen-rich blood to the body. capsular contracture: the most common complication of breast reconstruction surgery; occurs if the scar or capsule around the implant begins to tighten. capsule: the layer of cells around an organ such as the prostate. captioning: text display of spoken words presented on a television or a movie screen that allows a deaf or hard-of-hearing viewer to follow the dialogue and the action of a program simultaneously. carbohydrates: one of the three main classes of food and a source of energy. Carbohydrates are the sugars and starches found in breads, cereals, fruits, and vegetables, which, during digestion, are changed into a simple sugar called glucose. Glucose is stored in the liver until cells need it for energy. carbon monoxide (CO): a colorless, odorless gas which can be created whenever a fuel (such as wood, gasoline, coal, natural gas, or kerosene) is burning. carbuncles: clusters of boils on the skin. carcinogen: substance that is known to cause cancer. carcinoma: cancer found in body tissues that cover or line surfaces of organs, glands, or body structures. carcinoma in situ: cancer that is confined to the cells in which it first developed and has not invaded the surrounding tissues (metastasized). cardiac: pertaining to the heart. cardiac arrest: the stopping of the heartbeat. cardiac catheterization: a diagnostic procedure in which a tiny, hollow tube (catheter) is advanced from a vessel in the groin through the aorta into the heart in order to image the heart and blood vessels. cardiac output: total amount of blood being pumped by the heart over a particular period of time. cardiology: the clinical study and practice of treating the heart. cardiomyopathy: a disease of the heart muscle that causes it to lose its pumping strength.
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cardiopulmonary resuscitation (CPR): an emergency life-saving method in which artificial respirations and chest compressions are used to restart the heart and lungs. cardiovascular (CV): pertaining to the heart and blood vessel (circulatory) system. cardioversion: the procedure of applying electrical shock to the chest to change an abnormal heartbeat into a normal one. caregiver: someone who provides assistance, generally in the home environment, to an aging parent, spouse, other relative, or unrelated person, or to an ill or disabled person of any age. A caregiver can be a family member, friend, volunteer, or paid professional. carotid artery: the major artery in the neck that supplies blood to the brain. carpal tunnel syndrome: a condition in which the median nerve is compressed as it passes through the carpal tunnel in the wrist, a narrow confined space. Since the median nerve provides sensory and motor functions to the thumb and three middle fingers, many symptoms may result. Carpenter syndrome: A birth defect that typically includes traits such as abnormally short fingers, webbed toes, extra toes, underdeveloped jaw, highly arched palate, widely spaced eyes, and/or low-set, deformed ears. Half of patients with Carpenter syndrome also have heart defects. cartilage: a smooth material that covers bone ends of a joint to cushion the bone and allow the joint to move easily without pain. cast: a cast holds a broken bone in place as it heals, prevents, or decreases muscle contractures, or provides immobilization, especially after surgery. Casts immobilize the joint above and the joint below the area that is to be kept straight and without motion. cataract: a change in the structure of the crystalline lens that causes blurred vision. cathartics: laxatives. catheter: a thin, flexible tube that carries fluids into or out of the body. cavernous hemangioma: a raised, red or purple mark in the skin, made up of enlarged blood vessels. cecostomy: tube that goes through the skin into the beginning of the large intestine to remove gas or feces; it is a short-term way to protect part of the colon while it heals after surgery. cecum: beginning of the large intestine; it is connected to the lower part of the small intestine, the ileum. celiac disease (also called celiac sprue or gluten sensitive enteropathy): a sensitivity to gluten, a wheat
1794
Glossary
protein. Individuals with this disease must avoid gluten-containing grains, which include all forms of wheat, oats, barley, and rye. cellular pathology (also called cytopathology): the study of cellular alterations in disease. cellulitis: a bacterial infection of the skin that is characterized by swelling and tenderness. central auditory processing disorder: inability of individuals with normal hearing and intelligence to differentiate, recognize, or understand sounds. central nervous system: the brain and spinal cord. cephalohematoma: an area of bleeding underneath one of the cranial bones that appears as raised lump on the baby’s head. cerebellum: a large structure consisting of two halves (hemispheres) located in the lower part of the brain; responsible for the coordination of movement and balance. cerebral embolism: a stroke that occurs when a wandering clot (embolus), or some other particle, forms in a blood vessel away from the brain: usually in the heart. cerebral hemorrhage: a type of stroke that occurs when a defective artery in the brain bursts, flooding the surrounding tissue with blood. cerebral spinal fluid analysis (also called spinal tap or lumbar puncture): a procedure used to make an evaluation or diagnosis by examining the fluid withdrawn from the spinal column. cerebral thrombosis: the most common type of stroke; occurs when a blood clot (thrombus) forms and blocks blood flow in an artery bringing blood to part of the brain. cerebrovascular: pertaining to blood vessels in the brain. cerebrovascular accident: apoplexy or stroke; an impeded blood supply to the brain. cerebrovascular occlusion: an obstruction in the blood vessel in the brain. cerebrum: consists of two parts (lobes), left and right, which form the largest and most developed part of the brain; initiation and coordination of all voluntary movement take place within the cerebrum. The basal ganglia are located immediately below the cerebrum. cervical dysplasia: condition in which cells in the cervix have undergone precancerous changes, as detected by a Pap smear; treatment can prevent it from progressing to cervical cancer. cervical intraepithelial neoplasia (CIN): term used to classify the degree of precancerous changes in cells of the cervix in a condition called cervical dysplasia.
cervical spine: the area of the spinal cord located in the neck. cervicitis: an irritation of the cervix by a number of different organisms. Cervicitis is generally classified as either acute or chronic. cervix: the lower, narrow part of the uterus (womb) located between the bladder and the rectum. It forms a canal that opens into the vagina, which leads to the outside of the body. cesarean delivery (also called c-section): surgical procedure to deliver a baby through an incision in the lower abdomen and uterus. CHAMPUS: The Civilian Health and Medical Program for Uniformed Services. chemical burns: burns due to strong acids or alkalies coming into contact with the skin and/or eyes. chemical peels: a procedure often used to minimize sun-damaged skin, irregular pigment, and superficial scars. The top layer of skin is removed with a chemical application to the skin. By removing the top layer, the skin regenerates, often improving the skin’s appearance. chemosensory disorders: disorders or diseases of smell or taste. chemotherapy: treatment to destroy cancer cells with drugs. chickenpox: a highly infectious viral disease, usually associated with childhood. By adulthood, more than 95 percent of Americans have had chickenpox. The disease is caused by the varicella-zoster virus (VZV). Transmission occurs from person-to-person by direct contact or through the air. child safety seat: special seats for infants and toddlers that are secured in a vehicle with seat belts or special anchors to increase the safety of the child in the event of a crash. chlamydial infection: very common sexually transmitted disease or urinary tract infection caused by a bacteria-like organism in the urethra and reproductive system. chlorhydria: too much hydrochloric acid in the stomach. cholangiography: series of x-rays of the bile ducts. cholangitis: irritated or infected bile ducts. cholecystectomy: surgery to remove the gallbladder. cholecystitis: inflammation of the gallbladder wall. cholecystography: x-ray that shows the flow of contrast fluid through the intestines into the gallbladder. cholecystokinin: hormone released in the small intestine; causes muscles in the gallbladder and the colon to tighten and relax.
choledocholithiasis: a condition characterized by gallstones present in the bile ducts. cholelithiasis: a condition in which gallstones are present in the gallbladder. cholera: an acute, infectious disease caused by the consumption of water or food contaminated with the bacterium Vibrio cholerae. cholestasis: any interruption in the flow of bile. cholesteatoma: accumulation of dead cells in the middle ear caused by repeated middle ear infections. cholesterol: a waxy substance that is produced in the human body, animal fats, and in dairy products and is transported in the blood. chondroblasts: immature cartilage-producing cells. chorea: rapid, jerky movement of the body. chorionic villus sampling (CVS): diagnostic test, usually performed between the 10th and 12th weeks of pregnancy, in which a small sample of tissue is taken from the placenta and examined to detect genetic abnormalities in a fetus. choroid: the thin, blood-rich membrane that covers the whites of the eyeballs; responsible for supplying blood to the retina. chromatography: a laboratory test performed on a pregnant woman’s urine to detect illegal drugs, such as cocaine, heroin, and marijuana. chromosomes: filaments of genetic material in every cell nucleus that are made up of genes and that transmit genetic information from one generation of cells to the next. chronic: referring to a disease or disorder that usually develops slowly and lasts for a long period of time. chronic fatigue syndrome (also called CFS or chronic fatigue and immune dysfunction syndrome): a debilitating condition characterized by profound fatigue, regardless of bedrest. chronic lymphocytic leukemia (CLL): a slowly progressing cancer of the blood in which too many lymphocytes, a type of white blood cell, are produced by the bone marrow and by organs of the lymph system. chronic myelogenous leukemia (CML): a slowly progressing cancer of the blood in which too many white blood cells are produced in the bone marrow. chyme: thick liquid made of partially digested food and stomach juices; made in the stomach and moves into the small intestine for further digestion. ciliary body: the part of the eye that produces aqueous humor. cineangiography: the procedure of taking moving pictures to show the passage of dye through blood vessels.
Glossary
1795
circulatory system: pertaining to the heart and blood vessels, and the circulation of blood. circumcision: surgical procedure to remove the skin covering the end of the penis, called the foreskin. cirrhosis: a long-term disease of the liver in which the liver becomes covered with fiber-like tissue and has difficulty removing toxins and poisonous substances from the body. Alcohol, medications, and other substances may build up in the bloodstream and cause problems. Cirrhosis may be a result of scarring and damage from other diseases, such as biliary atresia and alcoholism. claudication: pain or fatigue in arms and legs due to poor supply of oxygen to the muscles. cleft lip: an abnormality in which the lip does not completely form. The degree of the cleft lip can vary greatly, from mild (notching of the lip) to severe (large opening from the lip up through the nose). cleft palate: occurs when the roof of the mouth does not completely close, leaving an opening that can extend into the nasal cavity. The cleft may involve either side of the palate. It can extend from the front of the mouth (hard palate) to the throat (soft palate). The cleft may also include the lip. climacteric (also called perimenopause): the transition period of time before menopause, marked by a decreased production of estrogen and progesterone, irregular menstrual periods, and transitory psychological changes. clinical trials: organized research studies that provide clinical data aimed at finding better ways to prevent, detect, diagnose, or treat diseases. Clostridium difficile (C. difficile): Bacteria naturally present in the large intestine that make a substance that can cause a serious infection called pseudomembranous colitis in people taking antibiotics. coagulation disorders: problems with either the inability for blood to clot properly, resulting in excessive bleeding, or excessive clotting leading to obstruction of veins and arteries (thrombosis). cochlea: snail-shaped structure in the inner ear that contains the organ of hearing. cochlear implant: medical device that bypasses damaged structures in the inner ear and directly stimulates auditory nerve to allow some deaf individuals to learn to hear and interpret sounds and speech. cognition: mental functions such as the ability to think, reason, and remember. cold knife cone biopsy: a procedure in which a laser or a surgical scalpel is used to remove a piece of tissue. This procedure requires the use of general anesthesia.
1796
Glossary
cold sore: small blisters around and in the mouth caused by the herpes simplex virus. colectomy: partial or complete removal of the large bowel or colon. colic: attacks of abdominal pain, caused by muscle spasms in the intestines. colitis: irritation of the colon. collagen: a protein produced by skin cells that provide strength and resilience to the skin. collagen injections: collagen, a protein, is sometimes injected to raise sunken scars. However, collagen is not safe in patients with certain diseases and retreatment is often necessary. collagen/fat injectable fillers (also called soft-tissue augmentation): a plastic surgery technique used to correct wrinkles, depressions in the skin, and/or scarring. collagenous colitis: type of colitis caused by an abnormal band of collagen, a threadlike protein. colon: large intestine. colon polyps: small, fleshy, mushroom-shaped growths in the colon. colonic inertia: condition of the colon in which the muscles do not work properly, causing constipation. colonoscopic polypectomy: removal of tumor-like growths (polyps) using a device inserted through a colonoscope. colonoscopy: a test that uses a long, flexible tube with a light and camera lens at the end (colonoscope) to examine inside the large intestine. colorectal cancer: cancer that occurs in the colon (large intestine) or the rectum. colorectal transit study: a test to show how well food moves through the colon. The patient swallows capsules containing small markers which are visible on x-ray. The patient follows a high-fiber diet during the course of the test, and the movement of the markers through the colon is monitored with abdominal x-rays taken several times three to seven days after the capsule is swallowed. colostomy: operation that makes it possible for stool to leave the body after the rectum has been removed. colostrum: thin, white, first milk produced by the breasts during late pregnancy and for a few days after childbirth. It provides a nursing infant with essential nutrients and infection-fighting antibodies. colposcopy (also called colposcopic biopsy): a procedure which uses an instrument with magnifying lenses, called a colposcope, to examine the cervix for abnormalities. If abnormal tissue is found, a biopsy is usually performed.
common bile duct: tube that carries bile from the liver to the small intestine. common bile duct obstruction: blockage of the common bile duct, often caused by gallstones. compact tissue: the harder, outer tissue of bones. comparative pathology: the study of disease in animals and how it compares in humans. complementary medicine: any form of therapy used in combination with other alternative treatments or standard/conventional medicine. complete blood count (CBC): a measurement of size, number, and maturity of the different blood cells in a specific volume of blood. composite resins (also called white fillings): a toothcolored plastic mixture filled with glass (silicon dioxide) that is used primarily for cosmetic improvements of the smile by changing the color of the teeth or reshaping disfigured teeth. compound fracture: a broken bone that protrudes through the skin. computed tomography scan (also called a CT or CAT scan): a diagnostic imaging procedure that uses a combination of x-rays and computer technology to produce cross-sectional images (often called slices), both horizontally and vertically, of the body. A CT scan shows detailed images of any part of the body, including the bones, muscles, fat, and organs. CT scans are more detailed than general x-rays. conductive hearing impairment: hearing loss caused by dysfunction of the outer or middle ear. cone biopsy (also called conization): a biopsy in which a larger, cone-shaped piece of tissue is removed from the cervix by using the loop electrosurgical excision procedure or the cold knife cone biopsy procedure. The cone biopsy procedure may be used as a treatment for precancerous lesions and early cancers. congenital: present at birth. congenital anomaly: a health problem present at birth (not necessarily genetic). congestive heart failure: a condition in which the heart cannot pump out all of the blood that enters it, which leads to an accumulation of blood in the vessels and fluid in the body tissues. conjunctiva: the membrane that lines the exposed eyeball and the inside of the eyelid. conjunctivitis: inflammation of the conjunctiva of the eye. constipation: a condition in which stool becomes hard and dry. contact dermatitis: a rash or an inflammation of the skin caused by an exposure to an allergen or irritant.
continence: ability to hold in a bowel movement or urine. continent ileostomy: operation to create a pouch from part of the small intestine. Stool that collects in the pouch is removed by inserting a small tube through an opening made in the abdomen. contractions, labor: rhythmic tightening of the muscular wall of the uterus to push the fetus down through the vagina during childbirth. contracture: inability to move a joint due to a permanent rigidity or contraction of a muscle. contusion (also called bruise): a collection of blood due to broken blood vessels underneath the skin usually caused by trauma. A bruise causes discoloration and swelling in the area. corn: a yellowish, callus growth that develops on top of the toes. cornea: the clear, dome-shaped surface that covers the front of the eye. corneal curvature: the shape of the front surface of the eye. coronal suture: the joining line (suture) between the frontal and parietal bones of the skull that crosses the top of the skull from temple to temple. coronary arteries: arteries that come from the aorta to provide blood to the heart muscle. coronary artery bypass graft (CAB or CABG): a surgical procedure in which a healthy blood vessel is transplanted from another part of the body into the heart to replace or bypass a diseased vessel. coronary artery spasm: a sudden closing of an artery, which cuts off blood flow to the heart and causes symptom of angina or heart attack. coronary heart disease: a condition in which the coronary arteries narrow from an accumulation of plaque (atherosclerosis) and cause a decrease in blood flow. coronary occlusion: an obstruction of one of the coronary arteries that decreases flow to the heart muscle. coronary thrombosis: the formation of a clot in one of the arteries that carry blood to the heart muscle. cortex: the outer layer of the cerebrum, densely packed with nerve cells. corticosteroids (also called glucocorticoids): potent, anti-inflammatory hormones that are made naturally in the body or synthetically for use as drugs; most commonly prescribed drug of this type is prednisone. cosmetic plastic surgery (also called aesthetic plastic surgery): one type of plastic surgery performed to repair or reshape otherwise normal structures of the body, primarily to improve the patient’s appearance and self-esteem.
Glossary
1797
craniectomy: excision of a part of the skull. craniofacial: pertaining to the head (skull) and face. craniosynostosis: a condition in which the sutures (soft spots) in the skull of an infant close too early, causing problems with normal brain and skull growth. Premature closure of the sutures may also cause the pressure inside of the head to increase and the skull or facial bones to change from a normal, symmetrical appearance to an abnormal, asymmetrical appearance. craniotomy: surgical opening of the skull to gain access to the intracranial structures. creeping eruption: a skin infection, caused by hookworms, that is characterized by severe itching. crepitus: grinding noise or sensation within a joint. Crohn’s disease (also called regional enteritis and ileitis): A chronic form of inflammatory bowel disease that usually affects the lower small intestine (called the ileum) or the colon, but can also affect the entire gastrointestinal tract. Crouzon’s syndrome: A birth defect characterized by abnormalities in the skull and facial bones. This syndrome often causes the skull to be short in the front and the back. Flat cheek bones and a flat nose are also typical of this disorder. crown: a “cap” that covers a cracked or broken tooth, unfixed by a filling, to approximate its normal size and shape. crust (also called scab): a formation of dried blood, pus, or other skin fluid over a break in the skin. cryosurgery: use of liquid nitrogen, or a probe that is very cold, to freeze and kill cancer cells. cryoprostatectomy: freezing of the prostate through the use of liquid nitrogen probes guided by transrectal ultrasound of the prostate. cryothalamotomy: a surgical procedure in which a super-cooled probe is inserted into a part of the brain called the thalamus in order to stop tremors. cryptorchidism: failure of one or both of the testicle(s) to move down into the scrotum. cryptosporidia: parasite that can cause gastrointestinal infection and diarrhea. cryptosporidiosis: a diarrheal infection caused by the parasite Cryptosporidium. The parasite is transmitted after drinking or swallowing contaminated food or water, including water swallowed while swimming. cubital tunnel: a tunnel of muscle, ligament, and bone on the inside of the elbow. cued speech: method of communication that combines speech reading with a system of handshapes placed near the mouth to help deaf or hard-of-hearing
1798
Glossary
individuals differentiate words that look similar on the lips. culdocentesis: a procedure in which a needle is inserted into the pelvic cavity through the vaginal wall to obtain a sample of pus. cupping: the use of warmed glass jars to create suction on certain points of the body. cyanosis: bluish discoloration of the skin from lack of oxygen. cyclic vomiting syndrome (CVS): sudden, repeated attacks of severe vomiting (especially in children), nausea, and physical exhaustion with no apparent cause. cyst: a fluid-filled or semi-solid sac in or under the skin. cystic duct: tube that carries bile from the gallbladder into the common bile duct and the small intestine. cystic duct obstruction: blockage of the cystic duct, often caused by gallstones. cystitis: inflammation of the bladder, usually caused by a bacterial infection. cystocele: condition in which weakened pelvic muscles cause the base of the bladder to drop from its usual position down into the vagina. cystometry: diagnostic procedure that measures bladder capacity and pressure changes as the bladder fills and empties. cystoscopy (also called cystourethroscopy): a procedure in which a cystoscope, a flexible tube and viewing device, is inserted through the urethra to examine the bladder and urinary tract for structural abnormalities or obstructions, such as tumors or stones. cystourethrocele: condition that results when the urethra and its supporting tissues weaken and drop into the vagina leading to stress incontinence. cystourethrogram (also called a voiding cystogram): a specific x-ray that examines the urinary tract. A catheter (hollow tube) is placed in the urethra (tube that drains urine from the bladder to the outside of the body) and the bladder is filled with a liquid dye. X-ray images will be taken as the bladder fills and empties. cytology: the study of individual cells. cytomegalovirus (congenital): one group of herpes viruses that infects humans and can cause a variety of clinical symptoms including deafness or hearing impairment; infection with the virus may be either before or after birth. debridement: the surgical removal of foreign material and/or dead, damaged, or infected tissue from a wound or burn. decibel: unit of measuring the intensity or loudness of sound.
deciduous teeth: also known as “baby” or primary teeth. deep vein thrombosis (DVT): blockage of the deep veins; particularly common in the leg. defecation: passage of bowel contents through the rectum and anus. defecography: an x-ray of the anorectal area that evaluates completeness of stool elimination, identifies anorectal abnormalities, and evaluates rectal muscle contractions and relaxation. defibrillator: an electronic device used to establish a normal heartbeat. dehydration: loss of fluids from the body, often caused by diarrhea. delayed gastric emptying (also called gastroparesis): nerve or muscle damage in the stomach that causes slow digestion and emptying, vomiting, nausea, or bloating. delusions: a perception that is thought to be true by the person experiencing it, although the perception is wrong. There are many types of delusions (i.e., delusions of grandeur). dementia: not a disease itself, but group of symptoms that characterize diseases and conditions; it is commonly defined as a decline in intellectual functioning that is severe enough to interfere with the ability to perform routine activities. dendrite: a threadlike extension from a nerve cell that serves as an antenna to receive messages from the axons of other nerve cells. dengue fever: a viral disease transmitted by Aedes mosquitoes mainly in tropical and subtropical areas of the world. dental amalgams (also called silver fillings): dental fillings that are comprised of a mixture of mercury (45 to 50 percent), and an alloy of silver, tin, and copper (50 to 55 percent). dental fluorosis: a condition that results from drinking overly fluoridated water that often causes the teeth to become discolored and the enamel of the teeth to look spotted, pitted, or stained. dental implants: small dental appliances that are inserted into the upper and lower jaws to help restore a mouth that has little or no non-restorable teeth. dental pulp: the soft tissue around the tooth that contains nerves, blood vessels, and connective tissue. dental sealant: a thin, plastic film that is painted on the chewing surfaces of the back teeth: the molars and premolars: to prevent tooth decay. dependent personality disorder: persons with this disorder rely heavily on others for validation and ful-
fillment of basic needs. Often unable to properly care for themselves, persons with dependent personality disorder lack self-confidence and security, and are deficient in making decisions. depression: a depressive disorder characterized by extreme feelings of sadness, lack of self-worth, and dejection. depth perception: the ability to distinguish objects in a visual field. dermabrasion: a procedure used to minimize small scars, minor skin surface irregularities, surgical scars, and acne scars. As the name implies, dermabrasion involves removing the top layers of skin with an electrical machine that “abrades” the skin. As the skin heals from the procedure, the surface appears smoother and fresher. dermaplaning: a plastic surgery technique used to treat deep acne scars with a hand-held instrument called a dermatome. dermatitis: an inflammation of the skin characterized by redness and itching. dermatofibroma: small, red or brown bumps in the skin. dermatome: an instrument that resembles an electric razor and has an oscillating blade that moves back and forth to evenly “skim” off the surface layers of skin that surround craters or other facial defects. dermatopathology: the study of the skin in diagnosing skin diseases. dermis: the middle layer of skin, which is made up of blood vessels, lymph vessels, hair follicles, sweat glands, collagen bundles, and fibroblasts. dermoid cyst: a benign tumor made up of hairs, sweat glands, and sebaceous glands. descending colon: the middle part of the colon located on the left side of the abdomen. DEXA (dual energy x-ray absorptiometry): imaging technique that uses a very low dose of radiation to measure bone density for the diagnosis of osteoporosis. diabetes mellitus: disorder that occurs when the body is not able to use sugar for growth and energy for daily activities. There are two main types of diabetes mellitus: insulin-dependent (Type 1) and noninsulindependent (Type 2). diagnosis: identifying a disease by its signs, symptoms, and laboratory findings. diagnostic mammogram: an x-ray of the breast used to diagnose unusual breast changes, such as a lump, pain, nipple thickening or discharge, or a change in breast size or shape. A diagnostic mammogram is also
Glossary
1799
used to evaluate abnormalities detected on a screening mammogram. diagnostic radiology: the use of various radiological techniques, mostly noninvasive, to diagnose an array of medical conditions. Diagnostic radiology includes the use of x-rays, computed tomography (CT) scans, magnetic resonance imaging (MRI) scans, and ultrasound. dialysis: a medical procedure to remove wastes and additional fluid from the blood after the kidneys have stopped functioning. diaper rash: an irritation of the skin in the diaper area. diaphragm: primary muscle used for respiration, located just below the lung bases. diarrhea: frequent, loose, and watery bowel movements. diastolic blood pressure: the lowest blood pressure measure in the arteries, which occurs between heartbeats. diathermy machine: a piece of equipment used in the operating room to control bleeding. diffuse axonal injury (DAI): the shearing (tearing) of the brain’s long connecting nerve fibers (axons) that can occur with severe brain injury. digestants: medications that aid or stimulate digestion. digestion: process the body uses to break down food into substances for energy, growth, and cell repair. digestive system: the group of organs that breaks down foods into chemical components that the body can absorb and use for energy, and for building and repairing cells and tissues. digital rectal examination (DRE): a procedure in which the physician inserts a gloved finger into the rectum to examine the rectum and the prostate gland for signs of cancer. dilate: relax; expand. dilation and curettage (also called D & C): a minor operation in which the cervix is dilated (expanded) so that the cervical canal and uterine lining can be scraped with a curette (spoon-shaped instrument). diphtheria: a serious, infectious disease that produces a toxin (poison) and an inflammation in the membrane lining of the throat, nose, trachea, and other tissues. diplopia: double vision. direct fluorescent antibody test (dFA): a test most frequently used to diagnose rabies in animals. disability: the inability to perform an activity in a normal way as a result of an impairment, such as not being able to walk due to a weakness or paralysis in a leg.
1800
Glossary
disc herniation (also called disc prolapse, disc bulge, or slipped disc): a protruding or bulging of the padded areas, called discs, between the vertebrae in the spine. dislocation: occurs when extreme force is put on a ligament causing the two bone ends to separate. Dislocations can also affect a joint, the point where two or more bones come together. The joint is created as a “ball-and-socket” joint. A dislocated joint causes the head of the bone (ball) to partially or completely come out of the socket. distention: bloating or swelling; usually referring to the abdomen. diuretic: a medication that lowers blood pressure by causing excess fluid to be excreted. diverticula: plural form of diverticulum. diverticulosis: condition that occurs when small pouches (diverticula) push outward through weak spots in the colon. diverticulum: small pouch in the colon. These pouches are not painful or harmful unless they become infected or irritated. dizziness: physical unsteadiness and lightheadedness that may be associated with balance disorders. DMD: Doctor of Dental Medicine. domestic violence: violence and abuse by family members or intimate partners such as a spouse, former spouse, boyfriend or girlfriend, ex-boyfriend or ex-girlfriend, or date. dopa decarboxylase: an enzyme present in the body that converts levodopa to dopamine. dopamine: a chemical substance, a neurotransmitter, found in the brain that regulates movement, balance, and walking. Doppler ultrasound: A procedure that uses sound waves to evaluate heart, blood vessels, and valves. ducts: narrow tube structures or channels that carry body fluids. In the breast, ducts transport milk from the lobules to the nipple. dumping syndrome (also called rapid gastric emptying): condition that occurs when food moves too fast from the stomach into the small intestine. duodenal ulcer: ulcer in the lining of the first part of the small intestine (duodenum). duodenitis: irritation of the first part of the small intestine (duodenum). duodenum: the first section of the small intestine. durable power of attorney: a legal document denoting a friend or family member as the legal guardian in case a person is unable to make medical decisions for himself/herself.
dysarthria: group of speech disorders caused by disturbances in the strength or coordination of the muscles of the speech mechanism as a result of damage to the brain or nerves. dysentery: infectious disease of the colon; symptoms include bloody, mucus-filled diarrhea, abdominal pain, fever, and loss of fluids from the body. dysequilibrium: any disturbance of balance. dysfluency: disruption in the smooth flow or expression of speech. dysgeusia: distortion or absence of the sense of taste. dyskinesia: an involuntary movement including athetosis and chorea. dysmenorrhea: pain or discomfort experienced just before or during a menstrual period. dysmenorrhea, primary: from the beginning and usually lifelong; severe and frequent menstrual cramping caused by uterine contractions. dysmenorrhea, secondary: due to some physical cause and usually of later onset; painful menstrual periods caused by an another medical condition present in the body (i.e., pelvic inflammatory disease, endometriosis). dysosmia: distortion or absence of the sense of smell. dyspareunia: pain in the vagina or pelvis experienced during sexual intercourse. dyspepsia: indigestion. dysphagia: difficulty in swallowing. dysphonia: any impairment of the voice or difficulty speaking. dysplasia: abnormal development of tissue. dyspnea: shortness of breath. dyspraxia of speech: partial loss of the ability to consistently pronounce words in individuals with normal muscle tone and coordination of the speech muscles. dysrhythmia: an abnormal heart rhythm. dysthymia (also known as dysthymic disorder): classified as a type of affective disorder or mood disorder that often resembles a less severe, yet more chronic form of major (clinical) depression. However, persons with dysthymia may also experience major depressive episodes at times. dystonia: abnormal muscle tone muscles. dystrophin: a protein; a chemical substance made by muscle fibers. E. coli O157:H7 (also called E. coli. or Escherichia coli): Species of bacteria found in the intestines of man and healthy cattle; often the cause of urinary tract infections, diarrhea in infants, and wound infections. ear infection: presence and growth of bacteria or viruses in the ear.
ear wax: yellow secretion (cerumen) from glands in the outer ear that keeps the skin of the ear dry and protected from infection. echocardiography: a procedure that evaluates the structure and function of the heart by using sound waves recorded on an electronic sensor that produce a moving picture of the heart and heart valves. eclampsia: a serious, life-threatening condition in late pregnancy in which very high blood pressure can cause a woman to have seizures. ectopic pregnancy (also called tubal pregnancy): an abnormal pregnancy in which the fertilized egg implants outside of the uterus, usually in one of the fallopian tubes. ectropion: turning outward of an edge; generally refers to a rare condition of the eyelid in which the lining of the eyelid is exposed. eczema (also called atopic dermatitis): a skin disorder that is characterized by itching, scaling, and thickening of the skin; usually located on the face, elbows, knees, and arms. EDD: Estimated Due Date. edema: swelling due to the build-up of fluid. ejection fraction: the measurement of the blood pumped out of the ventricles. elder care: a relatively new and growing area of healthcare concerned with providing medical and other services for the rapidly growing, aging population (most often persons 65 years of age and older). elective surgery (also called optional surgery): an operation the patient chooses to have done, which may not be essential to continuation of quality of life. electric and magnetic fields: refers to the electric and magnetic fields which surround both big power lines that distribute power and the smaller but closer electric lines in homes and appliances. electrical burns: burns due to contact with an electrical current. electrocardiogram (ECG or EKG): a test that records the electrical activity of the heart, shows abnormal rhythms (arrhythmias or dysrhythmias), and detects heart muscle damage. electrochemotherapy: uses a combination of chemotherapy and electrical pulses to treat cancer. electrocoagulation: procedure that uses an electrical current passed through an endoscope to produce coagulation. electroconvulsive therapy (ECT): a procedure that causes a brief convulsion by passing an electric current through the brain; used to treat some mental disorders.
Glossary
1801
electrodermal activity (EDA): measures changes in perspiration rate. electrodesiccation: electrosurgery which destroys tissue. electrodiagnostic tests (i.e., electromyography and nerve conduction velocity): studies that evaluate and diagnose disorders of the muscles and motor neurons. Electrodes are inserted into the muscle, or placed on the skin overlying a muscle or muscle group, and electrical activity and muscle response are recorded. electroencephalogram (EEG): a procedure that records the brain’s continuous electrical activity by means of electrodes attached to the scalp. electrolytes: chemicals such as salts and minerals needed for various functions in the body. electromyogram (EMG ): a test to evaluate nerve and muscle function. electrophysiological study (EPS): cardiac catheterization to study persons who either have or may have cardiac arrhythmias. electrosurgery: surgery which uses electrical instruments. embolization: the insertion of a substance through a catheter into a blood vessel to stop hemorrhaging, or excessive bleeding. embolus: a “wandering” blood clot. embryo: the fetus is first called an embryo during the first eight weeks after conception. emergency surgery (also called urgent surgery): an operation performed immediately as a result of a urgent medical condition. emerging infectious diseases: commonly defined as diseases that have newly appeared in a population, and/or diseases that have existed in the past, but are rapidly increasing in incidence or geographic range. Emerging diseases include: AIDS, Lyme disease, Escherichia coli O157: H7 (E. coli), and others. Re-emerging diseases include: malaria, tuberculosis, cholera, pertussis, influenza, and others. encephalitis: a viral infection of the brain. encopresis: constipation and intestinal obstruction (blockage) lead to an involuntary leakage of loose stool, or encopresis. endarterectomy: the surgical removal of plaque or blood clots in an artery. endemic: a disease caused by the health conditions constantly present within a community. It usually describes an infection that is transmitted directly or indirectly between humans and is occurring at the usual expected rate. endocarditis: a bacterial infection of the heart lining.
1802
Glossary
endocardium: the membrane that covers the inside surface of the heart. endocervical curettage (ECC): a procedure which uses a narrow instrument called a curette to scrape the lining of the endocervical canal. This type of biopsy is usually completed along with the colposcopic biopsy. endodontist (also called a pulp specialist): an endodontist has undergone specialized training in performing root canal therapy. endolymph: fluid in the labyrinth: the organ of balance located in the inner ear. endometrial ablation: a procedure to destroy the lining of the uterus (endometrium). endometrial biopsy: a procedure in which a sample of tissue is obtained through a tube which is inserted into the uterus. endometrial hyperplasia: abnormal thickening of the endometrium caused by excessive cell growth. endometrial implants: fragments of endometrium that relocate outside of the uterus, such as in the muscular wall of the uterus, ovaries, fallopian tubes, vagina, or intestine. endometriosis: condition in which tissue resembling that of the endometrium grows outside the uterus, on or near the ovaries or fallopian tubes, or in other areas of the pelvic cavity. endometrium: mucous membrane lining of the inner surface of the uterus that grows during each menstrual cycle and is shed in menstrual blood. endorphins: biochemical substances made by the body that may help reduce the level of pain. endoscope: small, flexible tube with a light and a lens on the end used to look into the esophagus, stomach, duodenum, colon, or rectum. It can also be used to take tissue from the body for testing or to take color photographs of the inside of the body. Colonoscopes and sigmoidoscopes are types of endoscopes. endoscopic retrograde cholangiopancreatography (ERCP): a procedure that allows the physician to diagnose and treat problems in the liver, gallbladder, bile ducts, and pancreas. The procedure combines x-ray and the use of an endoscope: a long, flexible, lighted tube. The scope is guided through the patient’s mouth and throat, then through the esophagus, stomach, and duodenum. The physician can examine the inside of these organs and detect any abnormalities. A tube is passed through the scope, and a dye is injected which will allow the internal organs to appear on an x-ray. endoscopic sphincterotomy (also called endoscopic papillotomy): operation to cut the muscle between the common bile duct and the pancreatic duct.
endoscopy: procedure that uses an endoscope, a long, flexible, lighted tube, to diagnose or treat a condition. endothelial cells: the delicate lining, only one cell thick, of the organs of circulation. enema: liquid put into the rectum to clear out the bowel or to administer medications or food. enlarged heart: a condition of the heart in which it is abnormally larger than normal. enteral nutrition (also called tube feeding): a way to provide food through a tube placed in the nose, stomach, or small intestine. A tube in the nose is called a nasogastric or nasoantral tube. A tube that goes through the skin into the stomach is called a gastrostomy or percutaneous endoscopic gastrostomy (PEG). A tube into the small intestine is called a jejunostomy or percutaneous endoscopic jejunostomy (PEJ) tube. enteritis: irritation of the small intestine. enterocele: condition caused by weakened muscles in the pelvis in which a portion of the intestines bulges into the top of the vagina. enteroscopy: examination of the small intestine with an endoscope. enterostomy: ostomy, or opening, into the intestine through the abdominal wall. enuresis: involuntary discharge of urine, usually during sleep at night. environmental medicine: the healthcare specialty concerned with human illnesses or dysfunctions that result from environmental factors. enzyme-linked immunosorbent assay (ELISA): blood test used to detect Helicobacter pylori bacteria; also used to diagnose an ulcer. enzymes: proteins that regulate chemical reactions in the body. eosinophilic gastroenteritis: infection and swelling of the lining of the stomach, small intestine, or large intestine. epicardium: the membrane that covers the outside of the heart. epidemic: a disease that spreads rapidly through a demographic segment of the human population, such as everyone in a given geographic area, or a similar population segment; also refers to a disease whose incidence is beyond what is expected. epidemiology: the study of the spread, control, and prevention of disease in a group of persons. epidermis: the outermost layer of skin. epidural anesthetic: an anesthetic which is injected into the “epidural space” in the middle and lower back, just outside the spinal space, to numb the lower extremities.
epilepsy (also called seizure disorder): a brain disorder involving recurrent seizures. epinephrine: one of two chemicals (the other is norepinephrine) released by the adrenal gland that increases the speed and force of heartbeats. It dilates the airways to improve breathing and narrows blood vessels in the skin and intestine so that an increased flow of blood reaches the muscles and allows them to cope with the demands of exercise. episiotomy: incision made in the skin between the vagina and anus to enlarge the vaginal opening and facilitate childbirth. epithelial cells: one of many kinds of cells that form the epithelium and absorb nutrients. epithelium: a specialized type of tissue that normally lines the surfaces and cavities of the body. erectile dysfunction (also called impotence): the inability to achieve an erection, and/or dissatisfaction with the size, rigidity, and/or duration of erections. ergonomics: the science of obtaining a correct match between the human body, work-related tasks, and work tools. eructation: belching. erysipelas: a bacterial skin infection that usually affects the arms, legs, or face, characterized by shiny, red areas, small blisters, and swollen lymph nodes. erythema multiforme: a skin condition characterized by symmetrical, red, raised skin areas all over the body. erythema nodosum: a skin condition characterized by red bumps that usually appear on the lower leg. erythrasma: a skin infection of the top layer of skin characterized by irregular pink patches that turn to brown scales. erythrocyte sedimentation rate (also called ESR or sed rate): a measurement of how quickly red blood cells fall to the bottom of a test tube. When swelling and inflammation are present, the blood’s proteins clump together and become heavier than normal. Thus, when measured, they fall and settle faster at the bottom of the test tube. Generally, the faster the blood cells fall, the more severe the inflammation. erythroplakia: a red patch of mucous membrane inside the mouth; one cause of oral cancer. esophageal manometry: a diagnostic test that helps to determine the strength of the muscles in the esophagus. It is useful in evaluating gastroesophageal reflux and swallowing abnormalities. A small tube is guided into the nostril, then passed into the throat, and finally into the esophagus. The pressure the esophageal muscles produce at rest is then measured.
Glossary
1803
esophageal Ph monitoring: a test to measure the amount of acid in the esophagus. esophageal spasms: muscle cramps in the esophagus that cause pain in the chest. esophageal stricture: narrowing of the esophagus often caused by acid flowing back from the stomach. esophageal ulcer: sore in the esophagus caused by long-term inflammation or damage from the residue of medications. esophageal varices: stretched veins in the esophagus that occur when the liver is not working properly. esophagitis: irritation of the esophagus, usually caused by acid that flows up from the stomach. esophagogastroduodenoscopy (also called EGD or upper endoscopy): a procedure that allows the physician to examine the inside of the esophagus, stomach, and duodenum. A thin, flexible, lighted tube, called an endoscope, is guided into the mouth and throat, then into the esophagus, stomach, and duodenum. The endoscope allows the physician to view the inside of this area of the body, as well as to insert instruments through a scope for the removal of a sample of tissue for biopsy (if necessary). esophagus: the muscular canal that connects the mouth to the stomach. estrogen: a hormone secreted by the ovaries which affects many aspects of the female body, including a woman’s menstrual cycle and normal sexual and reproductive development. estrogen replacement therapy (ERT): use of the female hormone estrogen to replace that which the body no longer produces naturally after medical or surgical menopause. euphoria: a feeling of elation or well-being that is not based on reality and is commonly exaggerated. evoked potentials: procedures that record the brain’s electrical response to sensory stimuli. exanthem: a rash. excisional: cutting away cancerous tissue with a scalpel or other instrument to completely remove it and (possibly) some surrounding tissue. There are many types of excisional surgeries, each named for the particular area of the body in which they are performed, or the particular purpose for which they are performed. excisional biopsy: surgery to remove tissue for examination. excoriation: an area of the skin covered by a crust, or scab, usually caused by scratching. expander/implant breast reconstruction: the use of an expander to create a breast mound, followed by the placement with a permanently-filled breast implant.
1804
Glossary
expectant management (also called expectant therapy): “watchful waiting” or close monitoring of a disease by a physician instead of immediate treatment. expiration: exhaling; giving off carbon dioxide. extensor muscle: any muscle that causes the straightening of a limb or other part. external urethral sphincter muscle: a voluntary and involuntary ring-like band of muscle fibers that are voluntarily contracted to stop urinating. extracorporeal shockwave lithotripsy (ESWL): a procedure that uses shock waves to break gallstones up into tiny pieces that can pass through the bile ducts without causing blockages. extragenital: outside of, away from, unrelated to the genital organs. extrahepatic biliary tree: bile ducts located outside the liver. extrapyramidal system: system consisting of nerve cells, nerve tracts, and pathways that connects the cerebral cortex, basal ganglia, thalamus, cerebellum, reticular formation, and spinal neurons that is concerned with the regulation of reflex movements such as balance and walking. extrinsic asthma: asthma that is triggered by an allergic reaction, usually to something that is inhaled. facial implant: cosmetic plastic surgery to change the shape of the chin, check, or jaw. This procedure is typically done to enhance certain facial features, or to bring a certain aspect of the face into proportion with the rest of the facial structures. factor: a protein in the blood that is needed to form the blood clot. factor V Leiden: an inherited mutation (change in a gene) in factor V which increases a person’s risk for venous thrombosis. fallopian tubes: two thin tubes that extend from each side of the uterus, toward the ovaries, as a passageway for eggs and sperm. false negative report: a negative result when in reality it is positive in nature. false positive report: a positive result when in reality it is negative in nature. familial: a clustering of disease in a family, with no specific inheritance pattern, but more cases than chance alone would predict. familial polyposis: an inherited disease that causes polyps in the colon. These polyps can lead to cancer. fat: one of three nutrients that supply calories to the body. fat necrosis: a benign breast condition in which painless, round, firm lumps caused by damaged and disin-
tegrating fatty tissues form in the breast tissue, often in response to a bruise or blow to the breast. fatty liver (also called steatosis): build-up of fat in liver cells. fecal fat test: test to measure the body’s ability to break down and absorb fat. fecal incontinence: being unable to hold stool in the colon and rectum. fecal occult blood test: a test to check for hidden (occult) blood in the stool. It involves placing a very small amount of stool on a special card, which is then tested in the physician’s office or sent to a laboratory; screening test for cancer of the colon or rectum. feces (also called stool): solid wastes that pass through the rectum as bowel movements. Stools are undigested foods, bacteria, mucus, and dead cells. fertile: able to become pregnant. festination: walking with a series of quick, small, shuffling steps as if hurrying forward to keep balance. fetal alcohol syndrome: set of serious birth defects that can occur when a pregnant woman drinks excessive amounts of alcohol. fetus: an unborn baby from the eighth week after fertilization until delivery. fever (also called pyrexia): an abnormal temperature of the body. A fever generally indicates that there is an abnormal process occurring in the body. fiber: substance in foods that comes from plants, which helps with digestion by keeping stool soft so that it moves smoothly through the colon. fibrillation: rapid contractions of the heart muscles. fibroadenoma: a solid, smooth, benign (non-cancerous) lump in the breast that is painless and moves around easily when touched. fibrocystic breast disease (also called fibroid breasts or generalized breast lumpiness): non-cancerous irregularities and lumpiness in the breast tissue. fibrocystic breasts: non-cancerous condition in which small lumps and cysts develop in the breasts. fibroid embolization: a new, experimental technique which involves identifying which arteries are supplying blood to the fibroids and then blocking off these arteries, which cuts off the fibroids’ blood supply and causes them to shrink. Physicians are still evaluating the long-term implications of this procedure on fertility and regrowth of the fibroid. fibroids: non-cancerous growths in, on, or within the walls of the uterus. fibromyalgia (also called fibrositis): a chronic, widespread pain in muscles and soft tissues surrounding the joints throughout the body.
fibrosis: the growth of scar tissue due to infection, inflammation, injury, or even healing. fine needle aspiration: the use of a thin, hollow needle to withdraw tissue from the body. fish poisoning: poisoning that occurs by eating various species of fish and shellfish at certain times of the year when they contain poisonous biotoxins. This can occur even if the fish is well-cooked. fistula: abnormal passage between two organs or between an organ and the outside of the body, caused when damaged tissues come into contact with each other and join together while healing. flap surgery: one type of surgery that involves transporting healthy, live tissue from one location of the body to another: often to areas that have lost skin, fat, muscle movement, and/or skeletal support. There are several different types of flap surgery methods that may be utilized, depending upon the location of the flap and the structures that need to be repaired. flatulence: excessive gas in the stomach or intestine; may also cause bloating. flexor muscle: any muscle that causes the bending of a limb or other body part. fluoride: a natural chemical that strengthens enamel, the hard outer coating on teeth, helps prevent tooth decay, and helps repair early damage to teeth. fluoroscopy: a study of moving body structures, similar to an x-ray “movie.” A continuous x-ray beam is passed through the body part being examined, and is transmitted to a TV-like monitor so that the body part and its motion can be seen in detail. flutter: ineffective contractions of the heart muscles. folate deficiency: the lack of folic acid (one of the B vitamins) in the blood. folic acid: a nutrient found in some green leafy vegetables, nuts, beans, citrus fruits, fortified breakfast cereals, and some vitamin supplements. Folic acid can help reduce the risk of birth defects of the brain and spinal cord. follicle-stimulating hormone (FSH): hormone secreted by the pituitary gland in the brain that stimulates the growth and maturation of eggs in females and sperm in males, and sex hormone production. folliculitis: an inflammation of the hair follicles due to an infection or irritation. food allergy: a physiological reaction caused when the immune system mistakenly identifies a normally harmless food as damaging to the body. food exchanges: a way to help people stay on special food plans by letting them replace items from one food group with items from another group.
Glossary
1805
food intolerance: an adverse reaction of the body to a certain food(s) that does not affect the immune system, although some symptoms may be the same as in food allergy. Lactose intolerance is an example. food-drug interaction: occurs when food eaten affects the ingredients in a medication being taken, preventing the medication from working the way it should. forehead lift: the surgical removal of excess fat and skin, as well as a tightening of the muscles in the forehead area. It can correct sagging brows or deep furrows between the eyes. It is often done in conjunction with a facelift in order to create a smoother facial appearance overall. fracture: a partial or complete break in the bone. freckles: darkened, flat spots that typically appear only on sun-exposed areas of skin. free skin graft: the detaching of healthy skin from one part of the body to repair areas of lost or damaged skin in another part of the body. frostbite: an injury to the body caused by freezing. frozen shoulder (also called capsulitis): a shoulder injury which has four stages: pain, pain and stiffness, stiffness, and resolution. functional disorders (also called motility disorders): conditions that result from poor nerve and muscle function. functional incontinence: leakage of urine due to a difficulty reaching a restroom in time because of physical conditions such as arthritis. fundus: the top of the enlarged uterus. gait: pattern of walking or locomotion. galactose: a type of sugar in milk products and sugar beets, also produced within the body. galactosemia: a build-up of galactose in the body, caused by a lack of one of the enzymes needed to breakdown galactose into glucose. gallbladder: organ that stores the bile made in the liver and sends bile into the small intestine to help digest fat. gallstones: solid masses or stones made of cholesterol or bilirubin that form in the gallbladder or bile ducts. gamma camera: a device used in nuclear medicine to scan patients who have been injected with small amounts of radioactive materials. ganglion cysts: non-cancerous, fluid-filled cysts are common masses or lumps in the hand; usually found on the back of the wrist. gangrene: a death of body tissue that usually occurs when there has been an interruption of blood supply, followed by bacterial invasion.
1806
Glossary
Gardner’s syndrome: A condition in which many polyps form throughout the digestive tract. gas: air that comes from the normal breakdown of food and is passed out of the body through the rectum (flatus) or the mouth (belch). gastrectomy: complete or partial removal of the stomach. gastric: related to the stomach. gastric juices: liquids produced in the stomach to help break down food and kill bacteria. gastric resection: operation to remove part or all of the stomach. gastric ulcer (also called stomach ulcer): open sore in the stomach lining. gastrin: hormone released after eating, which causes the stomach to produce more acid. gastritis: inflammation of the stomach lining. gastrocolic reflex: increase of muscle movement in the gastrointestinal tract when food enters an empty stomach, which may cause the urge to have a bowel movement right after eating. gastroenteritis: infection or irritation of the stomach and intestines, which may be caused by bacteria or parasites from spoiled food or unclean water, or eating food that irritates the stomach lining and emotional upsets such as anger, fear, or stress. gastroenterologist: physician who specializes in digestive diseases. gastroenterology: field of medicine concerned with the function and disorders of the digestive system. gastroesophageal reflux disease (GERD): a digestive disorder that is caused by gastric acid flowing from the stomach into the esophagus. gastroparesis (also called delayed gastric emptying): nerve or muscle damage in the stomach that causes slow digestion and emptying, vomiting, nausea, or bloating. gastroscopy: examining the lining of the esophagus, stomach, and the first part of the small intestine with a long viewing tube. gastrostomy: an artificial opening from the stomach to a hole (stoma) in the abdomen where a feeding tube is inserted. gastrostomy tubes: a gastrostomy tube (feeding tube) is inserted into the stomach if the patient is unable to take food by mouth. gated blood pool scan: a nuclear scan to see how the heart wall moves and how much blood is expelled with each heartbeat. general anesthetic: an anesthetic which causes the patient to become unconscious during surgery.
generalized anxiety disorder (GAD): a mental disorder that causes its sufferers chronic and exaggerated worry and tension that seem to have no substantial cause. Persons with generalized anxiety disorder often worry excessively about health, money, family, or work, and continually anticipate disaster. genes: basic, functional units of heredity, each occupying a specific place on a chromosome. genetic counseling: providing information, advice, and testing to prospective parents at risk of having a child with a birth defect or genetic disorder. genetics: the study of how traits and diseases are inherited from one generation to the next. genital herpes: a sexually transmitted disease caused by the herpes simplex virus. genital warts (also called venereal warts or condylomata acuminata): caused by a virus related to the virus that causes common skin warts. Usually, genital warts first appear as small, hard, painless bumps in the vaginal area, on the penis, or around the anus. genitals: external sex organs. genu valgum: commonly known as “knock knees.” genu varum: commonly known as “bowed legs.” gestational diabetes: form of diabetes which begins during pregnancy in women who have not been known to have diabetes before, and usually disappears following delivery. giant cell arteritis (also called cranial arteritis, temporal arteritis, or Horton’s disease): a disease that causes inflammation of the temporal arteries and other arteries in the head and neck, causing the arteries to narrow, reducing blood flow in the affected areas; may cause persistent headaches and vision loss. giardiasis: an infectious, diarrheal disease caused by the parasite Giardia lamblia, which can be transmitted through oral-fecal contact and by water contaminated by feces. GIFT (gamete intrafallopian transfer): method of treating infertility by removing eggs from a woman’s ovaries, combining them with sperm from her partner or a donor in the laboratory, and placing the eggs and sperm together in one of her fallopian tubes, where fertilization can occur. glaucoma: increased intraocular pressure that can result in optic nerve damage and loss of sight. glomerulonephritis: a type of glomerular kidney disease in which the kidneys’ filters become inflamed and scarred, and slowly lose their ability to remove wastes and excess fluid from the blood to make urine. glomerulosclerosis: the term used to describe scarring that occurs within the kidneys in the small balls of
tiny blood vessels called the glomeruli. The glomeruli assist the kidneys in filtering urine from the blood. glucagon: a protein hormone secreted by the pancreas to stimulate the liver to produce glucose. glucose: a simple sugar, which is the body’s main source of energy. glucose tolerance test: blood test used to make the diagnosis of diabetes, including gestational diabetes. glucose-6-phosphate dehydrogenase deficiency (G6PD): a deficiency of an enzyme (G6PD) in red blood cells, causing hemolytic anemia. gluten: a protein found in wheat, rye, barley, and oats. gluten sensitive enteropathy (also called celiac sprue or celiac disease): a sensitivity to gluten, a wheat protein. Individuals with this disease must avoid gluten-containing grains, which include all forms of wheat, oats, barley, and rye. gluteus maximus: large, superficial, buttock muscle. glycogen: converted glucose for storage. Glycogen plays a role in controlling blood sugar levels. goiter: an overgrown thyroid gland. gonadotropins: luteinizing hormone and folliclestimulating hormone,produced by the pituitary gland. gonorrhea: a common sexually transmitted disease caused by a bacterium, which can lead to infertility in women. Goodpasture syndrome: A rare, autoimmune disease that can affect the lungs and kidneys. gout: a result of a defect in body chemistry (such as uric acid in the joint fluid), this painful condition most often attacks small joints, especially the big toe. It can usually be controlled with medication and diet. grade: the grade of a cancer reflects how abnormal it looks under the microscope. There are several grading systems for different types of cancer. grades of movement: standardized means of documenting techniques of mobilization, relating it to the true feel of joint movement. grading: a process for classifying cancer cells to determine the growth rate of the tumor. The cancer cells are measured by how closely they look like normal cells. graft-versus-host disease (GVHD): when the donor’s immune system acts against the recipient’s tissue, after transplantation. granulocytes: a type of white blood cell. The different types of granulocytes include: basophils, eosinophils, and neutrophils. granuloma annulare: a chronic skin condition characterized by small, raised bumps that form a ring with a normal or sunken center.
Glossary
1807
gray matter: the darker-colored tissues of the central nervous system; in the brain, the gray matter includes the cerebral cortex, thalamus, basal ganglia, and outer layers of the cerebellum. guided imagery: envisioning a certain goal to help cope with health problems. Guillain-Barré syndrome: A disorder in which the body’s immune system attacks part of the nervous system. Gulf War syndrome: A widely used term referring to unexplained illnesses occurring in Gulf War veterans. gustation: act or sensation of tasting. gynecomastia: a condition in which the male’s breast tissue enlarges. Gynecomastia literally means “woman breast.” This increase in tissue usually occurs at times when the male is having hormonal changes, such as during infancy, adolescence, and old age. H2-blockers: medications used to treat gastroesophageal reflux disease (GERD) that decrease the amount of acid made by the stomach. The stomach lining has sites that react to a chemical normally found in the body called histamine. When histamine attaches to these sites, the stomach produces acid that aids in digestion of food. H2-blockers prevent the stomach from reacting to histamine, thereby decreasing stomach acid. Haemophilus influenzae (also called H. influenzae): Represents a group of bacteria that may cause different types of infections in infants and children. H. influenzae most commonly causes ear, eye, or sinus infections, and pneumonia. hair cells: sensory cells of the inner ear, which are topped with hair-like structures (stereocilia), which transform the mechanical energy of sound waves into nerve impulses. halitosis: an oral health condition characterized by consistently odorous breath. hallucinations: a strong perception of an event or object when no such situation is present; may occur in any of the senses (i.e., visual, auditory, gustatory, olfactory, or tactile). hammertoe: a permanent sideways bend in the middle toe joint. hamstrings: muscles located in the posterior compartment of the thigh. handicap: barriers imposed by society, the environment, or attitudes that prevent a person with a disability from performing a role that is normal for that person. hay fever (also called rhinitis): an inflammation of the mucous membrane that lines the nose, often due
1808
Glossary
to allergy to pollen, dust or other airborne substances, which causes sneezing, itching, a runny nose and nasal congestion. headache: pain or discomfort in the head or face area. Headaches can be single or recurrent in nature, and localized to one or more areas of the head and face. headache (primary): includes tension (muscular contraction), vascular (migraine), and cluster headaches not caused by other underlying medical conditions. headache (secondary): includes headaches that result from other medical conditions. These may also be referred to as traction headaches or inflammatory headaches. hearing: series of events in which sound waves in the air are converted to electrical signals that are sent as nerve impulses to the brain where they are interpreted. hearing aid: electronic device that brings amplified sound to the ear. hearing disorder: disruption in the normal hearing process; sound waves are not converted to electrical signals and nerve impulses are not transmitted to the brain to be interpreted. heart attack (also called myocardial infarction): occurs when one of more regions of the heart muscle experience a severe or prolonged decrease in oxygen supply caused by a blocked blood flow to the heart muscle. heart block: interrupted electrical impulse to heart muscles. heart rate: the rate at which the heart beats. Normal heart rates range between 60 and 100 beats per minute. heart valve prolapse: a condition of the heart valve in which it is partially open when it should be closed. heartbeat: one complete contraction of the heart. heartburn: painful, burning feeling in the chest caused by stomach acid flowing back into the esophagus. heart-lung machine: a machine that pumps blood during open heart surgery. heat exhaustion: a form of heat-related illness that is more severe than heat cramps and results from a loss of water and salt in the body. It occurs in conditions of extreme heat and excessive sweating without adequate fluid and salt replacement. Heat exhaustion occurs when the body is unable to cool itself properly. If left untreated, heat exhaustion can lead to heat stroke. heat stroke: the most severe form of heat illness and is a life-threatening emergency. It is the result of long, extreme exposure to the sun, in which a person does not sweat enough to lower body temperature.
heel spur: a bone growth on the heel bone. Heimlich maneuver: An emergency, first-aid treatment consisting of a series of under-the-diaphragm abdominal thrusts used on a person choking on food or a foreign object. Helicobacter pylori (H. pylori): Spiral-shaped bacterium found in the stomach. H. pylori damages stomach and duodenal tissue, causing ulcers; previously called Campylobacter pylori. hemarthrosis: bleeding into a joint. hematocrit: the measurement of the percentage of red blood cells found in a specific volume of blood. hematologist: a physician who specializes in the functions and disorders of the blood. hematology: the scientific study of blood and bloodforming tissues. hematoma: blood that collects under the skin or in an organ. hematopathology: the study of blood, bone marrow, and the organs and tissues that use blood cells to perform their functions. hematopoiesis: the process of producing and developing new blood cells. hematuria: the presence of red blood cells (RBCs) in the urine. hemochromatosis (also called iron overload disease): a metabolic disorder that causes increased absorption of iron, which is deposited in the body tissues and organs. The iron accumulates in the body where it may become toxic and cause damage. hemoglobin: substance in the red blood cells that supplies oxygen to the cells of the body. hemoglobin A1c (also called HbA1c test): a test that shows the average amount of sugar in the blood over the last three months. The result will indicate if the blood sugar level is under control. hemolytic anemia: one type of anemia in which the red blood cells are destroyed prematurely. hemolytic uremic syndrome: a rare kidney disorder that mostly affects children under the age of 10. It is often characterized by damage to the lining of blood vessel walls, destruction of red blood cells, and/or kidney failure. hemophilia (also called coagulation disorder): an inherited bleeding disorder caused by low levels, or absence of, a blood protein that is essential for clotting; hemophilia A is caused by a lack of the blood clotting protein factor VIII; hemophilia B is caused by a deficiency of factor IX. hemorrhoidectomy: the surgical removal of hemorrhoids.
hemorrhoids: swollen blood vessels in and around the anus that cause itching, pain, and sometimes bleeding. hepatic: related to the liver. hepatitis: inflammation of the liver that sometimes causes permanent damage; caused by viruses, drugs, alcohol, or parasites. Hepatitis has the following forms: hepatitis A: a form of infectious hepatitis caused by the hepatitis A virus. The virus may be spread by fecaloral contact, fecal-infected food or water, and may also be spread by a blood-borne infection (which is rare). hepatitis B: a form of infectious hepatitis caused by the hepatitis B virus. Transmission of the hepatitis B virus occurs through blood and body fluid exposure such as blood semen, vaginal secretions, or saliva. hepatitis C: a form of infectious hepatitis caused by the hepatitis C virus. Transmission of the hepatitis C virus occurs primarily from contact with infected blood, but can also occur from sexual contact or from an infected mother to her baby. hepatitis D: a form of infectious hepatitis caused by the hepatitis D (Delta) virus. This form of hepatitis can only occur in the presence of hepatitis B. Transmission of hepatitis D occurs the same way as hepatitis B. hepatitis E: a form of infectious hepatitis caused by the hepatitis E virus. This form of hepatitis is similar to hepatitis A. Transmission occurs through fecal-oral contamination. Hepatitis E is most common in poorly developed countries and is rarely seen in the US. hepatitis G: the newest form of infectious hepatitis. Transmission is believed to occur through blood and is seen in IV drug users, individuals with clotting disorders, such as hemophilia, and individuals who require hemodialysis for renal failure. hepatologist: physician who specializes in liver diseases. hepatomegaly: enlarged liver. hernia: a protrusion of part of an organ through the muscle that surrounds it. herpes genitalis: an infection caused by the herpes simplex virus (HSV) and usually spread by sexual contact. Symptoms may include painful blisters or open sores in the genital area, which may be preceded by a tingling or burning sensation in the legs, buttocks, or genital region. The herpes sores usually disappear within a few weeks, but the virus remains in the body and the lesions may recur from time to time. herpes zoster (also called shingles): a viral infection of the nerves, characterized by a painful skin rash of small blisters anywhere on the body.
Glossary
1809
hiatal hernia: small opening in the diaphragm that allows the upper part of the stomach to move up into the chest and causes heartburn from stomach acid flowing back up through the opening. high blood glucose: a condition that occurs in people with diabetes when their blood glucose levels are too high. high blood pressure: a condition in which the blood circulates through the arteries with too much force. high-density lipoprotein (HDL): a protein in the blood plasma that promotes breakdown and removal of cholesterol from the body. hip: the region on each side of the pelvis; made up of three sections: ilium, ischium, and pubis; the upper part of the femur (upper leg bone) fits into the hip via a ball-and-socket joint; the socket is a cup-shaped bone of the pelvis, called the acetabulum, and the ball is the head of the femur. Hirschsprung’s disease: Birth defect in which some nerve cells are lacking in the large intestine. hirsutism: excessive hairiness. histamine: a chemical present in cells throughout the body that is released during an allergic reaction and one of the substances responsible for the symptoms of inflammation. histrionic personality disorder: persons with this disorder are overly conscious of their appearance, are constantly seeking attention, and often behave dramatically in situations that do not warrant this type of reaction. The emotional expressions of persons with histrionic personality disorder are often judged as superficial and exaggerated. hives (also called urticaria): a condition in which red, itchy, and swollen areas appear on the skin: usually as an allergic reaction from eating certain foods or taking certain medications. hoarseness: abnormally rough or harsh-sounding voice caused by vocal abuse and other disorders. Hodgkin’s disease: A type of lymphoma, a cancer in the lymphatic system; a rare disease, accounting for less than 1 percent of all cases of cancer in the U.S., and occurs most often in people between the ages of 15 and 34, and in people over age 55. Hodgkin’s disease causes the cells in the lymphatic system to abnormally reproduce, eventually making the body less able to fight infection. Steady enlargement of lymph glands, spleen, and other lymphatic tissue occurs. Holter monitor: An EKG recording done over a period of 24 or more hours. hormone replacement therapy (HRT): use of the female hormones estrogen and progestin (a synthetic
1810
Glossary
form of progesterone) to replace those hormones the body no longer produces after menopause. hormone therapy: the use of hormones, medications, or surgery to suppress (block) or mimic hormones and alter the growth of hormone-sensitive cancer. hormones: chemical substances created by the body that control numerous body functions. hospice: literal meaning “a place of shelter.” Today, hospice refers to supportive care of a terminally ill patient. human chorionic gonadotropin: a hormone produced by the placenta about 10 days after fertilization. human papillomaviruses (HPVs): a group of viruses that can cause warts. Some HPVs are sexually transmitted and cause wart-like growths on the genitals. HPV is associated with some types of cancer. humerus: the bone of the upper arm. hyaloid canal: narrow passageway that allows blood to flow through the eye. hydrochloric acid: acid made in the stomach that works with pepsin and other enzymes to break down proteins. hydrocortisone: a hormone secreted by the adrenal cortex which affects metabolism. hydronephrosis: a condition that occurs as a result of urine accumulation in the upper urinary tract; usually occurs from a blockage somewhere along the urinary tract. hydrotherapy: rehabilitation exercises performed in water. hyperactive: describes a situation in which a body tissue is especially likely to have an exaggerated reaction to a particular situation. hyperextension: active or passive force which takes the joint into extension, but beyond its normal range. hyperglycemia (also called high blood glucose): a condition that occurs in people with diabetes when their blood glucose levels are too high. hyperopia: farsightedness. hyperplasia: an abnormal increase in the number of cells in a tissue or an organ (i.e., cervix or the lining of the uterus). hypertension: abnormally high blood pressure. hypertrophic obstructive cardiomyopathy (HOCM): a bulge in the ventricle that causes impeded blood flow. hypertrophy: an increase in the size of tissue. hypogeusia: diminished sensitivity to taste. hypoglycemia: condition in which the blood sugar is lower than normal.
hypomobility: a decrease in the normal range of joint movement. hyposmia: diminished sensitivity to smell. hypotension: abnormally low blood pressure. hypothalamus: small structure at the base of the brain that regulates many body functions, including appetite, body temperature, and stimulation of the pituitary gland. hypothermia: an abnormally low body temperature brought on by staying in cold temperatures for a long period of time; a life-threatening emergency. hypoxia: abnormally low oxygen content in the organs and tissues of the body. hysterectomy: surgical removal of the uterus. hysterosalpingography: x-ray examination of the uterus and fallopian tubes that uses dye and is often performed to rule out tubal obstruction. hysteroscope: a viewing instrument inserted through the vagina for a visual examination of the canal of the cervix and the interior of the uterus. hysteroscopy: a visual examination of the canal of the cervix and the interior of the uterus using a viewing instrument (hysteroscope) inserted through the vagina. IBCLC: International Board of Certified Lactation Consultants. ibuprofen: a nonsteroidal anti-inflammatory drug (NSAID) found in many over-the-counter medications (i.e., Advil or Motrin). ice therapy: cooling of deeper tissues. idiopathic: of unknown origin. idiopathic thrombocytopenic purpura: a blood disorder characterized by an abnormal decrease in the number of blood platelets, which results in internal bleeding. There are two forms of idiopathic thrombocytopenic purpura: acute thrombocytopenic purpura and chronic thrombocytopenic purpura. ileal: related to the ileum, the lowest end of the small intestine. ileoanal anastomosis (also called a pull-through operation): an operation to remove the colon and inner lining of the rectum, but leave the outer muscle of the rectum. The bottom end of the small intestine (ileum) is pulled through the remaining rectum and joined to the anus, allowing stool to pass normally. ileoanal reservoir: an operation to remove the colon, upper rectum, and part of the lower rectum. An internal pouch is created from the remaining intestine to hold stool. ileocecal valve: a valve that connects the bottom end of the small intestine (ileum) and the upper part of the
large intestine (cecum). This valve controls the flow of fluid in the intestines and prevents backflow. ileocolitis: irritation of the lower part of the small intestine (ileum) and colon. ileostomy: operation that makes it possible for stool to leave the body after the colon and rectum are removed. An opening is made in the abdomen and the bottom of the small intestine (ileum) attaches to it. ileum: lower end of the small intestine. illusions: a false perception; the mistaking of something for what is not. imaging: tests or evaluation procedures that produce pictures of areas inside the body. immobilization: preventing movement to allow for natural healing to take place. immune system: a collection of cells, proteins, antibodies, and organs that work together to protect the body from potentially harmful, infectious microorganisms, such as bacteria, viruses, and fungi. immunization: a process by which protection to an infectious disease is administered. immunocompromised: an abnormal condition in which one’s ability to fight infection is decreased. This can be due to a disease process, certain medications, or a condition present at birth. immunoglobulin E (IgE): a type of antibody, formed to protect the body from infection, which attaches to mast cells in the respiratory and intestinal tracts and may cause allergic rhinitis, asthma, or eczema. immunoglobulins: antibodies or proteins found in blood and tissue fluids produced by cells of the immune system to bind to substances in the body that are recognized as foreign antigens. Immunoglobulins sometimes bind to antigens that are not necessarily a threat to health and provoke an allergic reaction. immunology: the study of the body’s immune system and its functions and disorders. immunosuppresive medications: medications that suppress the body’s immune system; used to minimize rejection of transplanted organs. immunotherapy: treatment of allergy to substances such as pollens, house dust mites, fungi, and stinging insect venom involving giving gradually increasing doses of the substance, or allergen, to which the person is allergic. impaction: trapping of an object in a body passage, such as stones in the bile duct or stool in the colon. impaired glucose tolerance (IGT): a condition in which blood sugar levels are higher than normal, but are not high enough to be classified as diabetes; a risk factor for type 2 diabetes.
Glossary
1811
impairment: loss of normal function of part of the body due to disease or injury, such as paralysis of the leg. impedance plethysmography: a test to evaluate blood flow through the leg. impetigo: a bacterial skin infection characterized by microscopic, pus-filled blisters. impotence (also called erectile dysfunction): the inability to achieve an erection, and/or dissatisfaction with the size, rigidity, and/or duration of erections. in vitro fertilization: treatment for infertility in which a woman’s egg is fertilized outside her body with her partner’s sperm or sperm from a donor. incidence: statistic that equals the number of new cases of a particular disease that occur in a population during a defined period of time, usually one year. incontinence, urinary: uncontrollable, involuntary leaking of urine. indigestion (also called dyspepsia): poor digestion; symptoms include heartburn, nausea, bloating, and gas. infection: the invasion of the body by microorganisms that cause disease. infectious arthritis: an infection in the joint fluid and tissues. inferior vena cava: the large blood vessel (vein) that returns blood from the legs and abdomen to the heart. infertility: not being able to produce a child. inflammation: the response of the tissues of the body to irritation or injury. The signs of inflammation are redness, heat, swelling, and pain. inflammatory bowel diseases (IBD): diseases that cause irritation and ulcers in the intestinal tract. Crohn’s disease and ulcerative colitis are the most common inflammatory bowel diseases. influenza (also called the flu): a viral respiratory tract infection. The influenza viruses are divided into three types: A, B, and C. informed consent: a legal document that explains a course of treatment, the risks, benefits, and possible alternatives; the process by which patients agree to treatment. infusion therapy (also called intravenous therapy): the introduction of fluid other than blood into a vein. inguinal hernia: part of the small intestine that pushes through an opening in the abdominal muscle, causing a bulge underneath the skin in the groin area. inner ear: part of the ear that contains both the organ of hearing (cochlea) and the organ of balance (labyrinth).
1812
Glossary
inotropic medications: medications that increase strength of the contractions in the heart. inpatient surgery: surgery which requires the patient to be admitted and stay in the hospital. insomnia: inability to sleep or to remain asleep throughout the night. inspiration: inhaling; taking in oxygen. insulin: hormone produced by the pancreas, which helps glucose leave the blood and enter the muscles and other tissues of the body. insulin-dependent diabetes (also called type 1 diabetes): a condition in which the pancreas makes so little insulin that the body cannot use blood glucose as energy, which must be controlled with daily insulin injections. insulin-resistance: partial blocking of the effect of insulin. intercostal muscles: muscles lying between ribs; often injured by muscle strain. interferon: a biological response modifier that stimulates the growth of certain disease-fighting blood cells in the immune system. interleukin-2: a biological response modifier that stimulates the growth of certain blood cells in the immune system that can fight cancer. internal derangement of the joint: a dislocated jaw or displaced disc, or injury to the condyle (the rounded edges of the jaw). interstitial cystitis: a complex, chronic disorder characterized by an inflamed or irritated bladder wall. interventional radiology: an area of specialty within the field of radiology which uses various radiological techniques (such as x-ray, computed tomography (CT) scans, magnetic resonance imaging (MRI) scans, and ultrasounds) to place wires, tubes, or other instruments inside a patient to diagnose or treat an array of conditions. intervertebral disc: disc that forms a cartilaginous joint between the vertebrae to provide shock absorption. intestinal flora: bacteria, yeasts, and fungi that grow normally in the intestines. intestinal mucosa: surface lining of the intestines where the cells absorb nutrients. intolerance: allergy or sensitivity to a food, drug, or other substance. intracranial pressure (ICP): pressure inside the skull. intraductal papilloma: a small, wart-like growth that projects into the breast ducts near the nipple, which may cause a bloody or sticky discharge.
intrauterine insemination: treatment for infertility in which semen is introduced into the uterus via a slim tube inserted through the vagina. intravascular echocardiography: echocardiography used in cardiac catheterization. intravascular ultrasound: the use of ultrasound inside a blood vessel to visualize the interior of the vessel in order to detect problems. intravenous: introducing a fluid into the bloodstream through a vein (usually in the patient’s forearm). intravenous line: a thin, plastic tube inserted into a vein (usually in the patient’s forearm) through which a volume of fluid is injected into the bloodstream. intravenous pyelogram (IVP): a series of x-rays of the kidney, ureters, and bladder with the injection of a contrast dye into the vein; to detect tumors, abnormalities, kidney stones, or any obstructions, and to assess renal blood flow. intrinsic asthma: asthma that has no apparent external cause. invasive cancer: cancer that begins in one area and then spreads deeper into the tissues of that area. investigational new drug: a drug allowed by the U.S. Food and Drug Administration (FDA) to be used in clinical trials, but not approved for sale to the general public. iris: the colored part of the eye; partly responsible for regulating the amount of light permitted to enter the eye. iron-deficiency anemia: the most common type of anemia; characterized by a lack of iron in the blood, which is necessary to make hemoglobin. ischemia: lack of oxygen. ischemic colitis: decreased blood flow to the colon, which causes fever, pain, and bloody diarrhea. ischemic heart disease: coronary artery disease or coronary heart disease caused by narrowing of the coronary arteries and decreased blood flow to the heart. islets of Langerhans: pancreatic cells that produce insulin and glucagon; important regulators of sugar metabolism. isometric: muscle contraction without movement at the joint. isthmus: tissue that connects the lobes of the thyroid. jaundice: a yellow discoloration of the skin and whites of the eyes due to abnormally high levels of bilirubin (bile pigmentation) in the bloodstream. jejunostomy: operation to create an opening in the jejunum to a hole (stoma) in the abdomen, to allow for enteral nutrition.
jejunum: middle section of the small intestine between the duodenum and ileum. joint: where the ends of two or more bones meet. joint locking: extremely painful condition usually caused by entrapment of a loose body within the joint. Jordan frame: Specialized stretcher developed for transport of suspected spinal injured patients. jugular veins: veins that carry blood from the head back to the heart. jumper’s knee (also called patellar tendonitis): a condition characterized by inflammation of the tendons in the knee area that causes local pain and tenderness. juvenile rheumatoid arthritis (JRA): a form of arthritis in children ages 16 or younger that causes inflammation and stiffness of joints for more than six weeks. Unlike adult rheumatoid arthritis, which is chronic and lasts a lifetime, children often outgrow juvenile rheumatoid arthritis. However, the disease can affect bone development in the growing child. Kegel exercises: Repeatedly tightening and releasing the pelvic muscle, in order to prevent urine leakage. keloids: smooth, pink, raised, firm, fibrous growths on the skin that form secondary to injury. keratinocytes (also called squamous cells): the primary cell types found in the epidermis, the outer layer of skin. keratitis: inflammation of the cornea. keratoacanthomas: round, flesh-colored growths with craters that contain a pasty material. keratosis pilaris: a common skin condition characterized by small, pointed bumps, especially on the back and sides of the upper arms. ketoacidosis: high blood glucose, often caused by illness or taking too little insulin. ketone: break down product of fat that accumulates in the blood as a result of inadequate insulin or inadequate calorie intake. kidney stone: a solid piece of material that forms from crystallization of excreted substances in the urine. kidney transplantation: a procedure that places a healthy kidney from one person into a recipient’s body. kidneys: a pair of bean-shaped organs located below the ribs toward the middle of the back. knee reconstruction: surgical restoration of the knee. kyphosis: a forward curvature of the back bones (vertebrae) in the upper back area, giving a “humpback” appearance.
Glossary
1813
labia: the folds of skin at the opening of the vagina (and other organs). labyrinth: organ of balance located in the inner ear. The labyrinth consists of three semicircular canals and the vestibule. labyrinthine hydrops: excessive fluid in the organ of balance (labyrinth) that can cause pressure or fullness in the ears, hearing loss, dizziness, and loss of balance. labyrinthitis: viral or bacterial infection or inflammation of the inner ear that can cause dizziness, loss of balance, and temporary hearing loss. lactase: an enzyme in the small intestine needed to digest lactose, a sugar found in milk and milk products. lactase deficiency: lack of an enzyme made by the small intestine called lactase, which prevents the body from digesting lactose (a sugar found in milk and milk products) properly. lactose: sugar found in milk and milk products, which the body breaks down into galactose and glucose. lactose intolerance: inability to digest lactose, the sugar in milk, because the body does not produce the lactase enzyme. lactose tolerance test: a test that determines the body’s ability to digest lactose (a sugar found in milk and milk products). laminectomy: surgical procedure which includes removal of a portion of the lamina to provide more room in the vertebral canal; usually for disc herniation or spinal canal stenosis. Landau-Kleffner syndrome: A childhood disorder of unknown origin that can be identified by gradual or sudden loss of the ability to understand and use spoken language. language: system for communicating ideas and feelings using sounds, gestures, signs, or marks. language disorders: problems with verbal communication and the ability to use or understand the symbol system for interpersonal communication. lanugo: fine, downy hair that covers the fetus until shortly before or after birth. laparoscope: a long, thin tube with a camera lens attached that allows the physician to examine the organs inside the abdominal cavity: to check for abnormalities, and to operate through small incisions. laparoscopic cholecystectomy: an operation to remove the gallbladder. The physician inserts a laparoscope, and other surgical instruments, through small holes in the abdomen. The camera allows the physician to see the gallbladder on a television screen. The physician removes the gallbladder through the holes.
1814
Glossary
laparoscopic lymph node sampling: lymph nodes are removed through a viewing tube called a laparoscope, which is inserted through a small incision in the abdomen. laparoscopic lymphadenectomy: the removal of pelvic lymph nodes with a laparoscope performed through small incisions in the lower abdominal region. laparoscopy: use of a viewing tube with a lens or camera (and a light on the end), which is inserted through a small incision in the abdomen to examine the contents of the abdomen and remove tissue samples. laparotomy: a surgical procedure that involves an incision from the upper to lower abdomen; often used when making a diagnosis by less invasive tests is difficult. large intestine: part of the intestine that goes from the cecum to the rectum. laryngeal neoplasms: abnormal growths in the larynx (voice box) that can be cancerous or non-cancerous. laryngeal nodules: non-cancerous, callous-like growths on the inner parts of the vocal folds (vocal cords). laryngeal paralysis: loss of function or feeling of one or both of the vocal folds. laryngectomy: surgery to remove part or all of the larynx (voice box). laryngitis: hoarse voice or the complete loss of the voice because of irritation to the vocal folds (vocal cords). laryngoscopy: inspecting the larynx (voice box) with a mirror or viewing tube. larynx: valve structure between the trachea (windpipe) and the pharynx (the upper throat) that is the primary organ of voice production. laser resurfacing: uses high-energy light to burn away damaged skin. Laser resurfacing may be used to minimize wrinkles and fine scars. laser surgery: using a device which emits a beam of light radiation, surgeons can cauterize a wound, repair damaged tissue, or cut through tissue. lateral collateral ligament (LCL): the ligament that gives stability to the outer knee. lateral epicondylitis (also known as tennis elbow): pain is caused by damage to the tendons that bend the wrist backward away from the palm. lavage: cleaning of the stomach and colon using a special drink and enemas. laxatives medications to relieve constipation. lead poisoning: an abnormal condition often caused by breathing or swallowing substances that contain lead.
learning disability (LD): a disorder that affects people’s ability to either interpret what they see and hear, or to link information from different parts of the brain. These limitations are characterized by difficulty in reading, writing, and arithmetic. lens (also called crystalline lens): the transparent structure inside the eye that focuses light rays onto the retina. lesion: a destructive change in body tissue, such as a wound, injury, or inflammation. leukapheresis: a procedure to remove excess lymphocytes from the body. leukemia: a cancer of the blood-forming tissue. Leukemic cells look different than normal cells and do not function properly. leukoplakia: a whitish patch of mucous membrane inside the mouth; one cause of oral cancer. leukorrhea: whitish vaginal discharge during pregnancy. Levator syndrome: A feeling of fullness in the anus and rectum with occasional pain, caused by muscle spasms. levodopa (L-dopa): the single most effective anti-Parkinson drug; it is changed into dopamine in the brain. Lewy body: A pink-staining sphere, found in the bodies of dying cells, that is considered to be a marker for Parkinson’s disease. lice: tiny parasites that can infest the skin; characterized by intense itching. lichenification: skin that has thickened. ligament: a white, shiny, flexible band of fibrous tissue that binds joints together and connects various bones and cartilage. lipid: a fatty substance in the blood. lipomas: round or oval lumps under the skin caused by fatty deposits. lipoproteins: transporters of fatty substances in the blood. liposuction: type of cosmetic surgery in which localized areas of fat are removed from beneath the skin using a suction-pump device inserted in an incision. lithotripsy, extracorporeal shock wave (ESWL): method of breaking up bile stones and gallstones with a specialized tool and shock waves. liver: largest organ in the body, which carries out many important functions, such as making bile, changing food into energy, and cleaning alcohol and poisons from the blood. liver enzyme tests (also called liver function tests): blood tests to determine how well the liver and biliary system are working.
living will: a legal document which states your medical preferences for treatment and resuscitation in the event a person can no longer speak for himself/herself. LMP: last menstrual period. lobe: a roundish projection of any structure. In the breast, lobes of the mammary glands radiate from the central area to the nipple area like wheel spokes. lobectomy: removal of an entire lobe of the lung. lobule: a subdivision of a lobe in the breast. local anesthesia: anesthetic medicine injected into the site of the operation to temporarily numb that area. locally invasive: a tumor which can invade the tissues surrounding it by sending out “fingers” of cancerous cells into normal tissue. locking clip: a special device used when the vehicle’s lap/shoulder belts do not lock. A locking clip will help secure a child safety seat tightly into a vehicle. loop electrosurgical excision procedure (LEEP): a procedure which uses an electric wire loop and lowenergy current to remove abnormal tissue. loose body: name given to an object, located within a joint, that has become detached. lordosis (also called sway-back): an exaggeration of the forward curve of the lower part of the back. low blood glucose: a condition that occurs in people with diabetes when their blood glucose levels are too low. low-density lipoprotein (LDL): a blood substance containing large amounts of cholesterol. lower back (also called lumbar spine): a complex structure that connects the upper body to the lower body; consists of vertebrae, disks, spinal cord, and nerves. lower esophageal sphincter: muscle between the esophagus and stomach. lower GI (gastrointestinal) series (also called barium enema): a procedure that examines the rectum, the large intestine, and the lower part of the small intestine. A fluid called barium (a metallic, chemical, chalky, liquid used to coat the inside of organs so that they will show up on an x-ray) is given into the rectum as an enema. An x-ray of the abdomen shows strictures (narrowed areas), obstructions (blockages), and other problems. lumbar puncture (also called spinal tap): a special needle is placed into the lower back, into the spinal canal. This is the area around the spinal cord. The pressure in the spinal canal and brain can then be measured. A small amount of cerebral spinal fluid (CSF) can be removed and sent for testing to determine if
Glossary
1815
there is an infection or other problems. CSF is the fluid that bathes the brain and spinal cord. lumpectomy: a surgical procedure to remove a tumor and surrounding tissue. lung volume: the amount of air the lungs hold. luteinizing hormone (LH): hormone secreted by the pituitary gland in the brain that stimulates the growth and maturation of eggs in females and sperm in males. Lyme disease (LD): A multi-stage, multi-system bacterial infection caused by the spirochete Borrelia burgdorferi, a spiral-shaped bacterium that is most commonly transmitted by a tick bite. lymph: part of the lymphatic system; a thin, clear fluid that circulates through the lymphatic vessels and carries blood cells that fight infection and disease. lymph node biopsy: a procedure performed to remove tissue or cells from the body for examination under a microscope. lymph nodes (also called lymph glands): small organs located in the channels of the lymphatic system which store special cells to trap bacteria or cancer cells traveling through the body in lymph. Clusters of lymph nodes are found in the underarms, groin, neck, chest, and abdomen. lymph vessels: part of the lymphatic system; thin tubes that carry lymph fluid throughout the body. lymphadenectomy: a procedure in which lymph nodes are taken from the body for purposes of diagnosing or staging cancer. lymphangiogram: an x-ray that uses a special dye to determine whether cancer has spread to the lymph nodes. lymphangioma: a raised, yellow-tan or red mark in the skin, made up of enlarged lymphatic vessels. lymphatic system: a complex network of capillaries, thin vessels, valves, ducts, nodes, and organs that helps to protect and maintain the fluid environment of the body by filtering and draining lymph and by producing blood cells. lymphedema: a disorder in which lymph accumulates in the soft tissues, resulting in swelling. Lymphedema may be caused by inflammation, obstruction, or removal of the lymph nodes during surgery. lymphocytes: part of the lymphatic system; white blood cells that fight infection and disease. lymphocytic leukemia: a type of leukemia in which the cancer develops in the lymphocytes (lymphoid cells). macrodactyly: a congenital problem in which there is an abnormal growth of a finger.
1816
Glossary
macrosomia: a condition in which a baby is considerably larger than normal. macula: the portion of the eye that allows us to see fine details clearly. macular degeneration: degeneration in the macular region of the retina that results in decreased central vision and, sometimes, blindness. macular stains (also called angel’s kisses or stork bites): faint, red marks that appear on the skin at birth. Angel’s kisses are marks on the forehead and eyelids. Stork bites are marks on the back of the neck. macule: the smaller version of a patch; a flat, discolored spot. mad cow disease: scientifically known as bovine spongiform encephalopathy (BSE), this disease in cattle is related to a disease in humans called new variant Creutzfeldt-Jakob disease (nvCJD). Both disorders are fatal brain diseases caused by an unconventional transmissible agent. magnetic resonance imaging (MRI): a diagnostic procedure that uses a combination of large magnets, radiofrequencies, and a computer to produce detailed images of organs and structures within the body. major depression (also known as clinical depression or unipolar depression): classified as a type of affective disorder or mood disorder that goes beyond the day’s ordinary ups and downs, becoming a serious medical condition and important health concern in the US. malabsorption syndromes: conditions that may result when the small intestine cannot absorb nutrients from foods. malaria: a disease caused by a parasite that is transmitted person-to-person by the bite of an infected Anopheles mosquito. These mosquitoes are present in the tropics and subtropics in almost all countries. Malaria is the most deadly of all tropical parasitic diseases. malignant: cancerous cells are present. malignant melanoma: a rare, but sometimes deadly, skin cancer that begins as a mole that turns cancerous. malignant tumor: a mass of cancer cells that may invade surrounding tissues or spread to distant areas of the body. malnutrition: condition caused by not eating enough food or not eating a balanced diet. malocclusion: an orthodontic problem that means “bad bite,” including crowded, missing, or crooked teeth, extra teeth, or a misaligned jaw. mammogram: x-ray of the breast tissue.
mania: a mood disorder which may be characterized by extreme elation, impulsivity, irritability, rapid speech, nervousness, distractibility, and/or poor judgment. manic depression (also known as bipolar disorder): classified as a type of affective disorder or mood disorder that goes beyond the day’s ordinary ups and downs. Manic depression is characterized by periodic episodes of extreme elation, elevated mood, or irritability (also called mania) countered by periodic, classic depressive symptoms. manometry: tests that measure muscle pressure and movements in the gastrointestinal (GI) tract. Mantoux test: A skin test used to identify most people with M. tuberculosis within six to eight weeks after initial exposure. manual therapy: passive movement techniques. massage: mechanical form of therapy in which the soft tissues are made more pliable, promoting increased blood flow and healing. mast cells: cells, which synthesize and store histamines, found in most body tissues, particularly just below the epithelial surfaces, serous cavities, and around blood vessels. In an allergic response, an allergen stimulates the release of antibodies, which attach themselves to mast cells. mastalgia: pain in the breast that is generally classified as either cyclical (associated with menstrual periods) or non-cyclical. mastectomy: surgical removal of all or part of the breast. mastitis: an inflammation of the breast tissue. mastoid: back portion of the temporal bone behind the ear. mastoid surgery: surgical procedure to remove infection from the mastoid bone. maxillofacial: pertaining to the jaws and face. meal plan: a guide to help people include the proper amount of calories, carbohydrates, proteins, fats, vitamins, minerals, and fiber in their diet. mean blood pressure: average blood pressure, taking account of the rise and fall that occurs with each heartbeat. It is often estimated by multiplying the diastolic pressure by two, adding the systolic pressure, and then dividing this sum by three. measles: a very contagious viral illness characterized by a distinct rash and a fever; spread through airborne droplets of nasal secretions. Meckel’s diverticulum: Birth defect in which a small sac forms in the ileum (lower end of the small intestine).
meconium: a sticky, greenish-black substance that forms in the intestines during fetal development and is the first bowel movement of a newborn. medial collateral ligament (MCL): the ligament that gives stability to the inner knee. medial epicondylitis (also known as golfer’s elbow, baseball elbow, suitcase elbow, or forehand tennis elbow): pain caused by damage to the tendons that bend the wrist toward the palm. median nerve: large nerve, comprising segments from the cervical spine, that is involved in nerve function of the upper limb; commonly compressed in the carpal tunnel of the wrist. Medicaid: Federally- and state-funded healthcare program for low-income individuals. Medicare: Federally-funded healthcare program for individuals over age 65. megacolon: huge, swollen colon; results from severe constipation. megaloblastic (pernicious) anemia: a rare blood disorder in which the body does not absorb enough vitamin B12 from the digestive tract, resulting in an inadequate amount of red blood cells produced. Meige syndrome: A movement disorder that can involve excessive eye blinking (blepharospasm) with involuntary movements of the jaw muscles, lips, and tongue (oromandibular dystonia). melanin (also called pigment): a substance that gives the skin its color. melanocytes: cells present in the epidermis that produce melanin (skin pigment). melanoma: the most serious, life-threatening form of skin cancer. melasma: dark, brown, symmetrical patches of pigment on the face. menarche: a young woman’s first menstrual period. Ménétrier’s disease (also called giant hypertrophic gastritis): Long-term disorder that causes large, coiled folds in the stomach. Ménière’s disease: An inner ear disorder that can affect both hearing and balance; can cause vertigo, tinnitus, and the sensation of fullness in the ear. meningitis: inflammation of the meninges, the membranes that envelop the brain and the spinal cord. menisci: two crescent-shaped discs of connective tissue between the bones of the knees that act as shock absorbers to cushion the lower part of the leg from the weight of the rest of the body. menopause: end of menstruation; commonly used to refer to the period ending the female reproductive phase of life.
Glossary
1817
menorrhagia (also called dysfunctional uterine bleeding): the most common type of abnormal uterine bleeding characterized by heavy and prolonged menstrual bleeding. In some cases, bleeding may be so severe and relentless that daily activities become interrupted. menses: menstrual flow. menstruation: a cyclical process of the endometrium shedding its lining, along with discharge from the cervix and vagina, from the vaginal opening. This process results from the mature egg cell (ovum) not being fertilized by a sperm cell as it travels from one of the ovaries down a fallopian tube to the uterus, in the process called ovulation. mercury poisoning: an abnormal condition caused by breathing or swallowing a mercury substance. metabolism: the chemical activity that occurs in cells, releasing energy from nutrients or using energy to create other substances, such as proteins. metaplasia: the phenomenon by which one type of tissue is replaced by another type. metastasis: the spread of cancer cells to distant areas of the body by way of the lymph system or blood stream. metastasize: when cancer cells spread to other parts of the body. methyl-tert-butyl ether: a solution injected into the gallbladder to dissolve gallstones. metrorrhagia: any irregular, acyclic, non-menstrual bleeding from the uterus; bleeding between menstrual periods. micrographia: a change in handwriting with the script becoming smaller and more cramped. microsurgical fertilization: a procedure used to facilitate sperm penetration into the oocyte, and fertilization takes place under the microscope. middle ear: part of the ear that includes the eardrum and three tiny bones of the middle ear, ending at the round window that leads to the inner ear. milia: tiny, white, hard spots that look like pimples on a newborn’s nose. minimally invasive surgery: any technique involved in surgery that does not require a large incision. miosis: constriction of the pupil. misarticulation: inaccurately produced speech sound (phoneme) or sounds. miscarriage: spontaneous termination of a pregnancy before the fetus has developed enough to survive outside the uterus. mitral valve: the valve that controls blood flow between the left atrium and left ventricle in the heart.
1818
Glossary
mitral valve prolapse: a bulge in the valve between the left atrium and left ventricle of the heart that causes backward flow of blood into the atrium. mobility: movement. modified radical mastectomy: the removal of the entire breast (including the nipple, areola, and overlying skin), some of the lymph nodes under the arm (also called the axillary lymph glands), and the lining over the chest muscles. In some cases, part of the chest wall muscles is also removed. mold: a microscopic fungus that grows and lives on plant or animal matter or on non-organic objects. Most molds are made up of filaments and reproduce through the production of spores, which spread by air, water, or insects. moles: small skin marks caused by pigment-producing cells in the skin. Mongolian spots: Bluish-black marks on the lower back and buttocks; affects mainly African-American or Asian children. monoclonal antibodies: substances that can locate and bind to cancer cells wherever they are in the body. monounsaturated fats: dietary fats, such as olive oil or canola oil, that do not seem to have any affect on blood cholesterol. morning-after pills: hormonal medications to prevent pregnancy taken within 72 hours of having unprotected intercourse. Moro reflex: Movement of arms and legs that occurs when a newborn is startled by a loud sound or movement. Morton’s neuroma: A pinched nerve that usually causes pain between the third and fourth toes. motility: movement of food through the digestive tract. motion sickness: dizziness, sweating, nausea, vomiting, and generalized discomfort experienced when an individual is in motion. motor speech disorders: group of disorders caused by the inability to accurately produce speech sounds. moulding: elongation of the shape of a baby’s head due to delivery through the birth canal. moxibustion: the burning of herbal leaves on or near the body. mucosal lining: lining of gastrointestinal (GI) tract organs that makes mucus. mucosal protective drugs: medications that protect the stomach lining from acid. mucus: a thick, jelly-like substance made by the intestines and other organs of the body (such as the nose),
that helps coat and protect the lining of the organ. Mucus also helps stool pass through the large intestine and rectum more easily. multifidus: deep lumbar spine muscle that stabilizes the lumbar spine. multiple chemical sensitivity: a diagnostic label for people who suffer multi-system illnesses as a result of contact with, or proximity to, a variety of airborne agents and other substances. multiple sclerosis (MS): an unpredictable disease of the central nervous system that can be relatively benign, disabling, or devastating, leaving the patient unable to speak, walk, or write. multiple semen analysis: at least two semen examples are collected on separate days to examine the semen and sperm for various factors, such as semen volume, consistency, and pH, and the sperm count, motility, and morphology (shape). mumps: an acute and highly contagious viral disease that usually occurs in childhood. Spread by airborne droplets from the upper respiratory tract, the disease usually takes two to three weeks to appear. murmur: a blowing or rasping sound heard while listening to the heart that may or may not indicate problems within the heart or circulatory system. muscular dystrophy (MD): a broad term that describes a genetic (inherited) disorder of the muscles. MD causes the muscles in the body to become very weak. The muscles break down and are replaced with fatty deposits over time. The most common form of MD is called Duchenne muscular dystrophy (DMD). musculoskeletal system: the complex system involving the body’s muscles and skeleton, and including the joints, ligaments, tendons, and nerves. mycoplasma: very common sexually transmitted disease or urinary tract infection caused by a bacterialike organism in the urethra and reproductive system. mycosis fungoides: cutaneous T-cell lymphoma skin tumors. mydriasis: dilation of the pupil. myelogenous leukemia: a type of leukemia in which the cancer develops in the granulocytes or monocytes (myeloid cells). myelogram: involves the injection of a dye or contrast material into the spinal canal; a specific x-ray study that also allows careful evaluation of the spinal canal and nerve roots. myeloproliferative disorders: diseases in which the bone marrow produces too many of one of the three types of blood cells: red blood cells, which carry oxygen to all the tissues in the body; white blood cells,
which fight infection; and platelets, which control bleeding. myocardial infarction (also called heart attack): occurs when one of more regions of the heart muscle experience a severe or prolonged decrease in oxygen supply caused by a blocked blood flow to the heart muscle. myocardial ischemia: insufficient blood flow to part of the heart. myocardium: the muscle wall of the heart. myoclonus: jerking, involuntary movements of the arms and legs; may occur normally during sleep. myofascial pain: the most common form of temporomandibular disorder; discomfort or pain in the muscles that control jaw function and the neck and shoulder muscles. myomectomy: surgical procedure done to remove fibroids from the uterus while leaving the uterus intact. myopia: nearsightedness. myringotomy: a surgical opening of the eardrum to release pressure on the middle ear. narcissistic personality disorder:persons with this disorder present severely overly-inflated feelings of self-worth, grandiosity, and superiority over others. Persons with narcissistic personality disorder often exploit others who fail to admire them, and are overly sensitive to criticism, judgment, and defeat. nasal: relating to the nose. National Cancer Institute: The U.S. Government agency for cancer research and information. nausea: a feeling or sensation leading to the urge to vomit. near point of accommodation: the closest point in front of the eyes that an object may be clearly focused. near point of convergence: the maximum extent the two eyes can be turned inward. necrosis: pertaining to the death of tissue. needle aspiration (of the breast): a procedure that uses a thin needle and syringe to collect tissue or drain a lump after using a local anesthetic. needle biopsy: use of a needle to extract tissue, cells, or fluid for microscopic examination. neoadjuvant therapy: treatment such as chemotherapy, radiation therapy, or hormone therapy which is given before the primary treatment. neoplasm: any abnormal growth of new tissue; a proliferation of cells no longer under normal physiologic control. These may be benign (non-cancerous) or malignant (cancerous). nephrectomy: surgical removal of the kidney.
Glossary
1819
nephritis: inflammation of the kidneys. nephrology: the medical specialty concerned with diseases of the kidneys. nephropathy: diabetic kidney disease. nephrotic syndrome: a condition characterized by high levels of protein in the urine, low levels of protein in the blood, tissue swelling, and high cholesterol. nerve conduction tests: procedure to determine nerve impulse generation. nerve sparing technique: a surgical technique during a radial prostatectomy in which one or both of the neurovascular bundles controlling erections are spared. neural plasticity: ability of the brain and/or certain parts of the nervous system to change in order to adapt to new conditions, such as an injury. neural prostheses: devices that substitute for an injured or diseased part of the nervous system to enhance the function. neural stimulation: to activate or energize a nerve through an external source. neural tube defect: type of birth defect, such as spina bifida, that results from failure of the spinal cord or brain to develop normally in a fetus. neuralgia: pain in distribution of nerve or nerves. neuritis: inflammation of a nerve or nerves. neurofibromatosis: a group of inherited disorders in which non-cancerous tumors grow along several nerves; can affect the development of other tissues, including bones and skin, possibly leading to developmental abnormalities. neurogenic: of nerve origin. neurogenic bladder (also called neuropathic bladder): a bladder disorder that can be caused by a tumor or other condition of the nervous system. neurogenic communication disorder: inability to exchange information with others because of hearing, speech, and/or language problems caused by impairment of the nervous system. neurological: pertaining to the nervous system. neuron: a cell specialized to conduct and generate electrical impulses and to carry information from one part of the brain to another. neuropathology: the pathology of the nervous system. neuropathy: diabetic nerve damage. neurosonography: a procedure that uses ultra highfrequency sound waves that enable the physician to analyze blood flow in cases of possible stroke. neurotransmitters: chemical substances that carry impulses from one nerve cell to another; found in the space (synapse) that separates the transmitting neu-
1820
Glossary
ron’s terminal (axon) from the receiving neuron’s terminal (dendrite). nigral: of or referring to the substantia nigra. nitroglycerin: a medication used to relax or dilate arteries. nodule (also called papule): a solid, raised bump. noise-induced hearing loss: hearing loss that is caused either by a one-time or repeated exposure to very loud sound or sounds at various loudness levels over an extended period of time. non-Hodgkin’s lymphoma: a type of lymphoma, a cancer in the lymphatic system; causes the cells in the lymphatic system to abnormally reproduce, eventually causing tumors to grow. Non-Hodgkin’s lymphoma cells can also spread to other organs. noninvasive procedures: a diagnostic effort or treatment that does not require entering the body or puncturing the skin. nonsteroidal anti-inflammatory drugs (NSAIDs): medication that produces fever reducing, analgesic (pain relieving), and anti-inflammatory effects. nonsyndromic hereditary hearing impairment: hearing loss or deafness that is inherited and is not associated with other inherited clinical characteristics. nonulcer dyspepsia: constant pain or discomfort in the upper gastrointestinal (GI) tract. norepinephrine: a neurotransmitter found mainly in areas of the brain that are involved in governing autonomic nervous system activity, especially blood pressure and heart rate. nuclear medicine: a specialized area of radiology that uses very small amounts of radioactive substances to examine organ function and structure. Nutcracker syndrome: Abnormal muscle tightening in the esophagus. nutrients: proteins, carbohydrates, fats, vitamins, and minerals provided by food and necessary for growth and the maintenance of life. obesity: overweight by 30 percent of the ideal body weight. obsessive-compulsive disorder (OCD): an anxiety disorder in which a person has an unreasonable thought, fear, or worry that he/she tries to manage through a ritualized activity to reduce the anxiety. Frequently occurring disturbing thoughts or images are called obsessions, and the rituals performed to try to prevent or dispel them are called compulsions. obstetrician/gynecologist (OB/GYN): physician who specializes in general women’s medical care, diagnosis and treatment of disorders of the female reproductive system, and care of pregnant women.
obstruction: blockage in the gastrointestinal (GI) tract that prevents the flow of liquids or solids. occluded artery: an artery that is narrowed by plaque that impedes blood flow. occult: disease or symptoms that are not readily detectable by physical examination or laboratory tests. occult bleeding: blood in stool that is not visible to the naked eye. ocular hypertension: high (greater than 21 mm Hg) intraocular pressure. odorant: substance that stimulates the sense of smell. olfaction: the act of smelling. olfactometer: device for estimating the intensity of the sense of smell. oligomenorrhea: infrequent or light menstrual cycles. oncogenes: genes that promote normal cell division. “-oma”: a suffix meaning “tumor” or “lump.” oncologist: a physician who specializes in treating cancer, including surgical oncologist, radiation oncologist, pediatric oncologist, gynecologic oncologist, and medical oncologist. on-off effect, on-off phenomena: a change in the patient’s condition, with sometimes rapid fluctuations between uncontrolled movements and normal movement, usually occurring after long-term use of levodopa and probably caused by changes in the ability to respond to this drug. oophorectomy: removal of one or both ovaries. oophoritis: inflammation of the ovary. open heart surgery: surgery that involves opening the chest and heart while a heart-lung machine performs for the heart. open surgery: cutting the skin and tissues during surgery to expose a full view of the structures and organs involved in the procedure. open-set speech recognition: understanding speech without visual clues. ophthalmoscopy: examination of the internal structure of the eye. optic nerve: a bundle of more than one million nerve fibers that connects the retina with the brain. The optic nerve is responsible for interpreting the impulses it receives into images. optional surgery (also called elective surgery): an operation the patient chooses to have done, which may not be essential to continuation or quality of life. oral and maxillofacial surgeon: orthopaedic facial surgeon who is responsible for treating a wide variety of dental problems, including the removal of impacted teeth and reconstructive facial surgery.
oral cancer: a cancer found in the oral cavity (mouth), on the lip, and the oropharynx (the part of the throat at the back of the mouth). oral dissolution therapy: method of dissolving cholesterol gallstones. orchiectomy (also called castration): the surgical removal of the testicles. orchitis: inflammation of the testicle. oropharynx: the part of the throat at the back of the mouth. orthodontics: the dental specialty that focuses on the development, prevention, and correction of irregularities of the teeth, bite, and jaws. orthokeratology: the use of contact lenses to change the shape of the cornea in order to correct refractive error. orthopaedic surgeon (also called an orthopaedist): a physician who diagnoses, treats, manages the rehabilitation process, and provides prevention protocols for patients who suffer from injury or disease in any of the components of the musculoskeletal system. orthopaedic surgery (also called orthopaedics): the medical specialty devoted to the diagnosis, treatment, rehabilitation, and prevention of injuries and diseases of the body’s musculoskeletal system. orthosis: a brace or splint used to strengthen or stabilize part of the body, usually an arm or leg. orthostatic hypotension: a large decrease in blood pressure upon standing; may result in fainting. osteitis pubis: an inflammation of the pubic symphysis, the bone to which the two hip bones connect in front of the body. osteoarthritis: a condition caused by wear and tear that causes inflammation of the joint, causing swelling, pain, and stiffness. osteoblast: cell found in bone; its function is to form the tissue and minerals that give bone its strength. osteoclast: very large cell formed in bone marrow; its function is to absorb and remove unwanted tissue. osteocyte: cell found within the bone; its function is to help maintain bone as living tissue. osteophyte: outgrowth of bone. osteoporosis: disorder in which bones thin and become brittle and more prone to fracture; most common in women after menopause due to estrogen deficiency. ostomy: operation that makes an artificial opening in the abdomen to allow for the release of urine or feces. Colostomy and ileostomy are types of ostomy. otitis externa: inflammation of the outer part of the ear extending to the auditory canal.
Glossary
1821
otitis media: inflammation of the middle ear caused by infection. otoacoustic emissions: low-intensity sounds produced by the inner ear that can be quickly measured with a sensitive microphone placed in the ear canal. otolaryngologist: physician/surgeon who specializes in diseases of the ears, nose, throat, head, and neck. otologist: physician/surgeon who specializes in diseases of the ear. otoplasty (also called ear surgery): a type of cosmetic plastic surgery procedure aimed at setting prominent ears closer to the head, or reducing the size of larger ears. otosclerosis: abnormal growth of bone in the inner ear, which prevents structures within the ear from working properly, resulting in a gradual loss of hearing. otoscope: a lighted instrument that allows the physician to see inside the ear. ototoxic drugs: drugs that can damage the hearing and balance organs located in the inner ear. outer ear: external portion of the ear, consisting of the pinna, or auricle, and the ear canal. outpatient surgery: surgery which allows the patient to go home the same day. ovaries: pair of small glands, located on either side of the uterus, in which egg cells develop and are stored and the female sex hormones estrogen and progesterone are produced. overflow incontinence: leakage of urine that occurs when the quantity of urine produced exceeds the bladder’s capacity to hold it. overuse conditions: injuries due to minor trauma involving soft-tissue injuries: injuries that affect the bone, muscles, ligaments, and/or tendons. ovulation: release of a mature egg from an ovary. ovum: a mature egg cell released during ovulation from an ovary. oxytocin: hormone produced by the pituitary gland that stimulates contractions of the uterus during labor and release of milk during breastfeeding. pacemaker: an electronic device that is surgically implanted into the patient’s heart and chest to regulate heartbeat. pain: an unpleasant sensory or emotional experience primarily associated with tissue damage, or described in terms of tissue damage, or both. pain threshold: the least experience of pain that a person can recognize. pain tolerance level: the greatest level of pain that a person is prepared to tolerate.
1822
Glossary
palliative treatment: therapy that relieves symptoms, such as pain, but does not alter the course of the disease. Its primary purpose is to improve the quality of life. pallidotomy: a surgical procedure in which a part of the brain, called the globus pallidus, is lesioned in order to improve symptoms of tremor, rigidity, and bradykinesia. palming: an imaging technique involving the visualization of color. palpation: examination by feeling part of the body. palpitation: sensation of rapid heartbeats. palsy: paralysis of a muscle or group of muscles. pancreas: long gland that lies behind the stomach, which manufactures insulin and digestive enzymes. pancreatitis: inflammation of the pancreas. panic disorder: characterized by chronic, repeated, and unexpected panic attacks: bouts of overwhelming fear of being in danger when there is no specific cause for the fear. In-between panic attacks, persons with panic disorder worry excessively about when and where the next attack may occur. Pap test (also called Pap smear): Test that involves microscopic examination of cells collected from the cervix; used to detect changes that may be cancer or may lead to cancer, and to show non-cancerous conditions, such as infection or inflammation. papillary stenosis: condition in which the openings of the bile ducts and pancreatic ducts narrow. paranoid personality disorder: persons with this disorder are often cold, distant, and unable to form close, interpersonal relationships. Often overly, yet unjustifiably, suspicious of their surroundings, persons with paranoid personality disorder generally cannot see their role in conflict situations and often project their feelings of paranoia as anger onto others. paraplegia: loss of movement and sensation in both legs. parenteral nutrition (also called hyperalimentation or total parenteral nutrition): a way to provide liquid food mixture through a special tube in the chest. parietal cells: cells in the stomach wall that make hydrochloric acid. parkinsonism: the name given to a group of disorders with similar features; four primary symptoms, including tremor, rigidity, postural instability, and bradykinesia, resulting from the loss of dopamine-producing brain cells. Parkinson’s disease (PD): The most common form of parkinsonism; a slowly progressing, degenerative disease that is usually associated with the following
symptoms, all of which result from the loss of dopamine-producing brain cells: tremor or trembling of the arms, jaw, legs, and face; stiffness or rigidity of the limbs and trunk; bradykinesia (slowness of movement); postural instability, and/or impaired balance and coordination. paronychia: a skin infection around a finger or toenail. parosmia: any disease or perversion of the sense of smell, especially the subjective perception of odors that do not exist. partial (segmental) mastectomy: surgery to remove the breast cancer and a larger portion of the normal breast tissue around the breast cancer. The surgeon may also remove the lining over the chest muscles below the tumor and some of the lymph nodes under the arm. partial abdominoplasty: a “mini tummy tuck.” This procedure is ideal for individuals who have fat deposits limited to the area below the navel. partial colectomy: the removal of part of the large intestine. partial nephrectomy: surgery to remove the kidney; only the part of the kidney that contains the tumor is removed. patellar tendonitis: inflammatory condition of the patellar ligament, usually due to overuse. pathologist: physician who identifies diseases by studying cells and tissues under a microscope. pathology: the study of diseases. pauciarticular: a form of juvenile rheumatoid arthritis that affects four or less joints. peak flow meter (PFM): a device used to measure the air flowing out of the lungs, called peak expiratory flow rate (PEFR). During an asthma or other respiratory flare up, the large airways in the lungs slowly begin to narrow. This will slow the speed of air leaving the lungs and can be measured by a PFM. This measurement is very important in evaluating how well or how poorly the disease is being controlled. prick skin test: a test to determine if a patient is allergic to certain substances. A physician places a drop of the substance being tested on the patient’s forearm or back and pricks the skin with a needle, allowing a tiny amount to enter the skin. If the patient is allergic to the substance, a wheal (mosquito bite-like bump) will form at the site within about 15 minutes. peak flow monitoring: a measure of lung function. pediatric dentist: a specialist in the field of dentistry whose primary concern involves the oral healthcare of children, from infancy through the teenage years.
pediatrics: the branch of medicine that deals with diagnosis, treatment, and prevention of diseases in children. pelvic examination: an internal examination of the uterus, vagina, ovaries, fallopian tubes, bladder, and rectum. pelvic inflammatory disease (PID): inflammation of the pelvic organs caused by a type of bacteria. pelvic lymph node dissection: removal of some lymph nodes from the pelvis. pelvic node dissection: a procedure in which lymph nodes near the prostate are removed to determine if cancer has spread. pelvis: a basin-shaped structure that supports the spinal column and contains the sacrum, coccyx, and hip bones (ilium, pubis, and ischium). penis: the outer reproductive organ of a male. pepsin: enzyme made in the stomach that breaks down proteins. peptic: related to the stomach and the duodenum, where pepsin is present. peptic ulcer: sore in the lining of the esophagus, stomach, or duodenum; usually caused by the bacterium Helicobacter pylori. An ulcer in the stomach is a gastric ulcer. An ulcer in the duodenum is a duodenal ulcer. perception (hearing): process of knowing or being aware of information through the ear. percutaneous transhepatic cholangiography: xray of the gallbladder and bile ducts; a dye is injected through the abdomen to make the organs show up on the x-ray. percutaneous transluminal coronary angioplasty (PTCA): a technique to treat heart disease and chest pain by using angioplasty in the coronary arteries to permit more blood flow into the heart. perforated ulcer: ulcer that breaks through the wall of the stomach or duodenum and causes the stomach contents to leak into the abdominal cavity. perforation: hole in the wall of an organ. perfusion: flow. perianal: area around the anus. pericardiocentesis: a diagnostic procedure that uses a needle to draw fluid from the pericardium (the membrane that surrounds the heart). pericarditis: inflammation of the membrane that surrounds the heart. pericardium: the membrane that surrounds the heart. perilymph fistula: leakage of inner ear fluid to the middle ear that occurs without apparent cause, or is
Glossary
1823
associated with head trauma, physical exertion, or barotrauma. perimenopause (also called climacteric): the transition period of time before menopause, marked by a decreased production of estrogen and progesterone, irregular menstrual periods, and transitory psychological changes. perineal: related to the perineum. perineum: area between the anus and the sex organs. periodontal disease (also called gum diseases): serious bacterial infections that destroy the gums and the surrounding tissues of the mouth. periodontist: a specialist in the field of dentistry responsible for the care and prevention of gum-related diseases, guided bone regeneration, and dental implants. periosteum: fiber-like covering of the bones; beneath the hard outer shell of the periosteum, there are tunnels and canals through which blood and lymphatic vessels run to carry nourishment for the bone. peripheral stem cell transplantation: a process in which the stem cells (immature cells from which blood cells develop) are removed, treated with anticancer drugs, and frozen until returned to the patient. peristalsis: wavelike contractions that move food through the digestive tract. peritoneum: lining of the abdominal cavity. peritonitis: infection of the peritoneum. personal flotation device (PFD): any type of item that keeps a person afloat in water. Only U.S. Coast Guard-approved PFDs should be used on boats. pertussis (also called whooping cough): mainly affects infants and young children; caused by a bacterium, pertussis is characterized by paroxysms of coughing that end with the characteristic whoop as air is inhaled. Pertussis caused thousands of deaths in the 1930s and 1940s, but with the advent of a vaccine, the rate of death has declined dramatically. pessary: rubber or plastic device that is inserted through the vagina to help hold the uterus in place in women who have prolapse of the uterus. petechia: tiny red dots under the skin that are the result of very small bleeds. Peutz-Jeghers syndrome: Inherited condition in which many polyps grow in the intestine. Peyronie’s disease: A plaque, or hard lump, that forms on the erection tissue of the penis. The plaque often begins as an inflammation that may develop into a fibrous tissue. Pfeiffer syndrome: A birth defect characterized by abnormalities of the skull, hands, and feet.
1824
Glossary
Phalen’s test: Test for carpal tunnel syndrome in which the wrists are flexed for one minute. phantom pain: pain that occurs after an amputation, below the level of the amputated limb. pharynx: space behind the mouth that serves as a passage for food from the mouth to the esophagus and for air from the nose and mouth to the larynx. phlebotomy: a procedure that involves removing blood from the body. phobia: an uncontrollable, irrational, and persistent fear of a specific object, situation, or activity. phonology: study of speech sounds. photodynamic therapy: uses a certain type of light and a special chemical to kill cancer cells. photophobia: sensitivity to light. photorefractive keratectomy (PRK): procedure using an excimer laser to change the cornea. physiatry: branch of medicine that deals with restoring function for a person who has been disabled as a result of a disease, disorder, or injury. pigmentosa: a rare, inherited, skin disease that causes the skin to become very sensitive to ultraviolet light. pinguecula: irritation caused by the degeneration of the conjunctiva. pituitary gland: gland at the base of the brain that secretes hormones and regulates and controls other hormone-secreting glands and many body processes, including reproduction. pityriasis rosea: a common skin condition characterized by scaly, pink, and inflamed skin. placenta: organ that develops in the uterus during pregnancy; links the blood supplies of a pregnant woman to the fetus to provide nutrients and remove waste products. placenta previa: abnormal location of the placenta in the lower part of the uterus, near or over the cervix. placental abruption: premature detachment of the placenta from the wall of the uterus, causing severe bleeding that is life threatening to both a pregnant woman and fetus. plantar fascia: a long band of connecting tissue running from the heel to the ball of the foot. plantar warts: warts that occur on the sole of the foot and look like calluses; result from an infection or a specific virus. plaque: fat or substances attached to the artery wall. plasma: the watery, liquid part of the blood in which the red blood cells, the white blood cells, and platelets are suspended. plastic surgery: the surgical specialty that deals with the reconstruction of facial and body tissue that re-
quires a reshaping or remolding due to disease, a defect, or disorder: in order to approximate a normal appearance or to repair working ability. plateletpheresis: a procedure to remove extra platelets from the blood. platelets: cells found in the blood that are needed to control bleeding; often used in the treatment of leukemia and other forms of cancer. pleura: membrane that covers the outside of the lung. pleural effusion: a collection of fluid between the lung and chest wall. pleurisy: inflamed membranes around the lungs. pluripotent stem cell: the most primitive, undeveloped blood cell. pneumatic otoscope: an instrument that blows a puff of air into the ear to test eardrum movement. pneumoconiosis: a lung disease caused by the longterm breathing (ingestion) of dust. pneumonectomy: removal of an entire lung. pneumothorax: air becomes trapped in the pleural space (the area between the lung and the chest wall); causes the lung to collapse. poliomyelitis: a highly contagious infectious disease caused by various types of poliovirus. Spread though feces and airborne particles, the poliovirus usually causes no more than a mild illness. However, some of the more serious manifestations of the disease include meningitis, which can lead to extensive paralysis. polyarticular: a form of juvenile rheumatoid arthritis that affects five or more joints. polycystic kidney disease (PKD): a genetic disorder characterized by the growth of numerous cysts filled with fluid in the kidneys. polycythemia vera: a blood disorder in which there is an increase in all types of blood cells, particularly red blood cells. polydactyly: a congenital problem characterized by an increase in the number of fingers or toes. polymenorrhea: too frequent menstruation. polymyalgia rheumatica: condition of unknown cause that affects the lining of joints, particularly in the shoulders and hips. polyp: growth that projects, usually on a stem, from a membrane in the body; can sometimes develop into cancer. polyposis: presence of many polyps. polyunsaturated fat: a type of fat found in vegetable oils and margarines that does not appear to raise blood cholesterol levels. pontic tooth: false tooth.
porcelain veneers: a ceramic material is bonded to the front of teeth to change the tooth’s color, size, and/ or shape. porphyria: group of rare, inherited, blood disorders in which cells fail to change chemicals (porphyrins) to the substance (heme) that gives blood its color. portal hypertension: abnormally high blood pressure in the portal vein, which supplies the liver with blood from the intestine. portal vein: large vein that carries blood from the intestines and spleen to the liver. portosystemic shunt: operation to create an opening between the portal vein and other veins around the liver. port-wine stain: a flat, pink, red, or purple colored birthmark. port-wine stains (also called nevi flammeus): permanent flat, pink, red, or purple marks on the skin. positron emission tomography (PET) scan: a computer-based imaging technique that uses radioactive substances to examine body processes. For example, a PET scan of the heart provides information about the flow of blood through the coronary arteries to the heart. post-anesthesia care unit (also called recovery room): the area a patient is brought to after surgery to recover. postcholecystectomy syndrome (also called biliary dyskinesia): condition that occurs after gallbladder removal in which the muscle between the gallbladder and the small intestine does not work properly, causing pain, nausea, and indigestion. posterior chamber: the back section of the eye’s interior. posterior cruciate ligament (PCL): the ligament, located in the center of the knee, that controls backward movement of the tibia (shin bone). posterior optical segment: portion of the eye located behind the crystalline lens, and including vitreous, choroid retina, and optic nerve. posterior vitreous detachment (PVD): the separation of the vitreous from the retina. posteromedial shin splint: a type of shin splint that affects the back and inner part of the muscles of the shin and is caused by running and/or by wearing inappropriate footwear. postgastrectomy syndrome: condition that occurs after an operation to remove the stomach (gastrectomy). postlingually deafened: individual who becomes deaf after having learned language.
Glossary
1825
post-Lyme disease syndrome (PLDS): a condition also known as chronic Lyme disease, characterized by persistent musculoskeletal and peripheral nerve pain, fatigue, and memory impairment. postmenopausal bleeding: any bleeding that occurs more than six months after the last normal menstrual period at menopause. post-traumatic stress disorder (PTSD): a debilitating condition that often follows a terrifying physical or emotional event causing the person who survived the event to have persistent, frightening thoughts and memories, or flashbacks, of the ordeal. Persons with PTSD often feel chronically, emotionally numb. Once referred to as “shell shock” or “battle fatigue.” postvagotomy stasis: delayed stomach emptying; occurs after surgery on the vagus nerve. pouch: special bag worn over a stoma to collect stool; sometimes referred to as an ostomy appliance. predisposition: tendency to develop a certain disease. prednisolone: corticosteroid medication; usually used for inflammation. preeclampsia: a condition characterized by pregnancy-induced high blood pressure, protein in the urine, and swelling (edema) due to fluid retention. prelingually deafened: individual who is either born deaf or who lost hearing early in childhood, before learning language. premature: a baby born before full term or 37 weeks of gestation. premature ejaculation (PE): the inability to maintain an erection long enough for mutual satisfaction. premenstrual dysphoric disorder (PMDD): a much more severe form of the collective symptoms known as premenstrual syndrome (PMS), premenstrual dysphoric disorder (PMDD) is considered a severe and chronic medical condition that requires attention and treatment. premenstrual syndrome (PMS): a group of physical and emotional symptoms that some women experience during their menstrual cycle. Although the symptoms usually cease with onset of the menstrual period, in some women, symptoms may last through and after their menstrual periods. presbycusis: loss of hearing that gradually occurs because of changes in the inner or middle ear in individuals as they grow older. presbyopia: a form of farsightedness in which it is difficult to focus on close objects or to read. preterm labor: labor that begins before the 37th week of pregnancy.
1826
Glossary
prevalence: statistic that equals the total number of people in a population with a disease at a time. priapism: persistent erection of the penis, usually accompanied by tenderness and pain. prickly heat: a rash caused by trapped sweat under the skin. primary sclerosing cholangitis: irritation, scarring, and narrowing of the bile ducts inside and outside the liver. primary site: the location where cancer begins. Primary cancer is named after the organ in which it originates. For example, cancer that starts in the kidney is always kidney cancer, even if it spreads (metastasizes) to other organs such as bones or lungs. proctalgia fugax: intense pain in the rectum that occasionally happens at night; caused by muscle spasms around the anus. proctectomy: operation to remove the rectum. proctitis: inflammation of the rectum. proctocolectomy (also called coloproctectomy): operation to remove the colon and rectum. proctocolitis: inflammation of the colon and rectum. proctologist: physician who specializes in disorders of the anus and rectum. proctoscope: short, rigid metal tube used to look into the rectum and anus. proctoscopy: examination of the rectum and anus with a proctoscope. proctosigmoiditis: inflammation of the rectum and the sigmoid colon. proctosigmoidoscopy: endoscopic examination of the rectum and sigmoid colon. progesterone: a hormone secreted by the ovaries which affect manyaspects of the female body, including menstrual cycles and pregnancy. prolactin: a hormone secreted by the pituitary gland which affects growth of the mammary glands. progestin: synthetic form of the female sex hormone progesterone. prognosis: predicting the likely outcome of a disease based on the condition of the patient and the action of the disease. prokinetic drugs: medications that cause the muscles in the gastrointestinal tract to move food. prolactin: hormone produced by pituitary gland that stimulates breast development and milk production. prolapse: condition that occurs when a body part slips from its normal position. prolapse of the uterus: displacement of the uterus down into the vagina caused by a weakening of supporting tissues in the pelvis.
prostatalgia: pain in the prostate gland. prostate: a sex gland in men. It is about the size of a walnut, and surrounds the neck of the bladder and urethra, the tube that carries urine from the bladder. It is partly muscular and partly glandular, with ducts opening into the prostatic portion of the urethra. It is made up of three lobes: a center lobe with one lobe on each side. prostate acid phosphatase (PAP): an enzyme produced by the prostate that is elevated in some patients when prostate cancer has spread beyond the prostate. prostatectomy: surgical procedure for the partial or complete removal of the prostate. prostate-specific antigen (PSA): an antigen made by the prostate gland and found in the blood; may indicate cancer in the prostate gland. prostate-specific antigen (PSA) blood test: a blood test used to help detect prostate cancer by measuring a substance called prostate-specific antigen produced by the prostate. prostatism: any condition of the prostate that causes interference with the flow of urine from the bladder. prostatitis: an inflamed condition of the prostate gland that may be accompanied by discomfort, pain, frequent urination, infrequent urination, and, sometimes, fever. prosthesis: an artificial body part replacement. prosthodontist: a dental specialist who has undergone additional training and certification in the restoration and replacement of broken teeth with crowns, bridges, or removable prosthetics (dentures). protein: substance found in many parts of the body that helps the body to resist disease. proteinuria: large amounts of protein in the urine. proton pump inhibitors: medications that stop the stomach’s acid pump. prune belly syndrome (also called Eagle-Barrett syndrome): condition of newborn babies, in which the baby has no abdominal muscles, so the stomach looks like a shriveled prune. pruritus ani: itching around the anus. pseudomembranous colitis: severe irritation of the colon caused by Clostridium difficile bacteria; occurs after taking oral antibiotics, which kill bacteria that normally live in the colon. psoriasis: a chronic skin condition characterized by inflamed, red, raised areas that develop silvery scales. psoriatic arthritis: a form of arthritis associated with psoriasis, a skin and nail disease. psychiatrist: a medical doctor who specializes in the diagnosis and treatment of mental disorders.
psychologist: a specialist in the study of the structure and function of the brain and related behaviors or mental processes. puberty: a sequence of events by which a child becomes a young adult; characterized by secretions of hormones, development of secondary sexual characteristics, reproductive functions, and growth spurts. pubic symphysis: anterior joint of the pelvis. pudendal block: pain relieving procedure used during childbirth in which an anesthetic is injected into tissues surrounding the pudendal nerves on either side of the vagina. It blocks pain in the tissues between the vagina and anus. pulmonary: pertains to lungs and respiratory system. pulmonary artery: blood vessel delivering oxygenpoor blood from the right ventricle to the lungs. pulmonary edema: a condition in which there is a fluid accumulation in the lungs caused by an incorrectly functioning heart. pulmonary hypertension: abnormally high blood pressure in the arteries of the lungs. pulmonary valve: the heart valve located between the right ventricle and the pulmonary artery that controls blood flow to the lungs. pulmonary vein: the vessel that carries newly oxygenated blood to the heart from the lungs. pulse oximeter: a device that measures the amount of oxygen in the blood. punch grafts: small skin grafts to replace scarred skin. A hole is punched in the skin to remove the scar, which is then replaced with unscarred skin (often from the back of the earlobe). Punch grafts can help treat deep acne scars. pupil: the dark center in the middle of the iris through which light passes to the back of the eye. pupillary response: the constriction or dilation of the pupil as stimulated by light. purging: persons with bulimia nervosa engage in a destructive pattern of ridding their bodies of the excess calories (to control their weight) by: vomiting, abusing laxatives or diuretics, taking enemas, and/or exercising obsessively: a process called purging. purines: components of certain foods that metabolize into uric acid in the body. pustule (also called pimple): inflamed lesions that look like pink bumps. pyelonephritis: an infection of the kidney. pyloric sphincter: muscle between the stomach and the small intestine. pyloric stenosis: narrowing of the opening between the stomach and the small intestine.
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1827
pyloroplasty: operation to widen the opening between the stomach and the small intestine to allow contents to pass more freely from the stomach. pylorus: opening from the stomach into the top of the small intestine (duodenum). pyogenic granuloma: red, brown, or bluish-black raised marks caused by excessive growth of capillaries. pyramidal pathway: a collection of nerve tracts that travel from the cerebral cortex through the pyramid of the medulla oblongata in the brainstem to the spinal cord. Within the pyramid of the medulla, fibers cross from one side of the brain to the opposite side of the spinal cord; the pyramidal pathway is intact in Parkinson’s disease. Qi: Chinese word for life force. quadriceps: a large, four-part muscle at the front of the thigh that facilitates leg extension. quadriplegia: loss of movement and sensation in all four limbs. rabies: a widespread, viral infection of warm-blooded animals caused by a virus in the Rhabdoviridae family Rabies attacks the nervous system and, once symptoms develop, is 100 percent fatal in animals. radial keratotomy: a surgical procedure in which incisions are made into the epithelium of the cornea to correct refractive errors. radiation: use of high-energy radiation from x-rays, neutrons, and other sources to kill cancer cells and shrink tumors. radiation colitis: damage to the colon from radiation therapy. radiation enteritis: damage to the small intestine from radiation therapy. radiation therapy (also called radiotherapy): treatment with high-energy rays (such as x-rays or gamma rays) to kill cancer cells; may be by external radiation or by internal radiation from radioactive materials placed directly in or near the tumor. radical mastectomy: surgery to remove the entire breast (including the nipple, areola, and overlying skin), the lymph nodes under the arm, also called the axillary lymph glands, and the chest muscles. radical prostatectomy: surgery to remove the prostate along with the two seminal vesicle glands attached to the prostate. radical retropubic prostatectomy: an operation to remove the entire prostate gland and seminal vesicles through the lower abdomen. radioisotope: a radioactive material injected into the body so that a nuclear scanner can make pictures.
1828
Glossary
radioisotope scan: a procedure that uses radioactive substances introduced into the body to create an image. radioisotopes: materials that produce radiation. radiologist: a physician specializing in the medical field of radiology. radionuclide bone scan: a nuclear imaging technique that uses a very small amount of radioactive material, which is injected into the patient’s bloodstream to be detected by a scanner. This test shows blood flow to the bone and cell activity within the bone. radionuclide scan: an imaging scan in which a small amount of radioactive substance is injected into the vein. A machine measures levels of radioactivity in certain organs, thereby detecting any abnormal areas or tumors. radionuclide ventriculography: a diagnostic procedure used to determine the shape and size of the heart’s chambers. radiopharmaceutical (also called a tracer or radionuclide): basic radioactively-tagged compound necessary to produce a nuclear medicine image. radius: the shorter of the two bones of the forearm. radon: a colorless, naturally-occurring, radioactive, inert gas formed by radioactive decay of radium atoms in soil or rocks. Rancho scales: Levels of a patient’s response to external stimuli and the environment following a brain injury. range of motion: measurement of the extent to which a joint can go through all of its normal spectrum of movements. rape: forced or manipulated nonconsensual sexual contact, including vaginal or anal intercourse, oral sex, or penetration with an object. RAST (RadioAllergoSorbent Test, a trademark of Pharmacia Diagnostics): a laboratory test used to detect IgE antibodies to specific allergens. A RAST requires a blood sample, which is sent to a medical laboratory where tests are done with specific foods to determine whether the patient has IgE antibodies to that food. reactive arthritis (also called Reiter’s syndrome): a type of arthritis that occurs as a reaction to infection. recommended dietary allowance (RDA): recommendations for daily intake of specific nutrients for groups of healthy individuals set by the Food and Nutrition Board of the National Research Council of the National Academy of Science. reconstructive plastic surgery: one type of plastic surgery that is performed on abnormal structures of
the body that may be caused by trauma, infection, developmental abnormalities, congenital defects, disease, and/or tumors. This type of surgery is usually performed to improve function, but may also be performed to approximate a normal appearance. rectal manometry: test that uses a thin tube and balloon to measure pressure and movements of the rectal and anal sphincter muscles. rectal prolapse: condition in which the rectum slips so that it protrudes from the anus. rectal ultrasound: a test in which a probe is inserted in the rectum and directs sound waves at the prostate. The patterns of the sound waves form an image of the prostate gland on a screen. rectocele: condition in which weakening of the lower vaginal wall causes the rectum to bulge into the vagina. rectum: lower end of the large intestine, leading to the anus. recur: to occur again; reappearance of cancer cells at the same site or in another location. red blood cells (also called RBCs or erythrocytes): blood cells that transport oxygen to all the tissues in the body. reflux (also called regurgitation): condition that occurs when gastric juices or small amounts of food from the stomach flow back into the esophagus and mouth. reflux esophagitis: irritation of the esophagus because stomach contents flow back into the esophagus. refractive error: the degree to which light reaches the back of the eye: myopia, hyperopia, astigmatism. regional anesthetic: an anesthetic used to numb a portion of the body. regurgitation: backward flow of blood caused by a defective heart valve. rehabilitation: the process of helping a person achieve the highest level of function, independence, and quality of life possible. From the Latin “habilitas,” which means “to make able.” renal: pertains to kidneys. renal angiography (also called renal arteriography): a series of x-rays of the renal blood vessels with the injection of a contrast dye into a catheter, which is placed into the blood vessels of the kidney; to detect any signs of blockage or abnormalities affecting the blood supply to the kidneys. renal ultrasound: a non-invasive test in which a transducer is passed over the kidney producing sound waves which bounce off of the kidney, transmitting a picture of the organ on a video screen. The test is used to determine the size and shape of the kidney, and to
detect a mass, kidney stone, cyst, or other obstruction or abnormalities. required surgery: an operation which is necessary to continue quality of life. Required surgery may not have to be done immediately, like emergency surgery. residential care facility (RCF): an out-of-home care option for elderly persons who are no longer able to live alone and independently, but do not require skilled nursing care. RCFs typically provide assistance with personal hygiene, grooming, and other activities of daily living, as well as recreational and social services. respiration: gas exchange from air to the blood and from the blood to the body cells. respiratory diphtheria: when a person is infected with diphtheria, the bacterium usually multiplies in the throat, leading to the respiratory version of diphtheria. A membrane may form over the throat and tonsils, causing a sore throat. Other common symptoms of respiratory diphtheria may include: breathing difficulty, a husky voice, enlarged lymph glands, and an increased heart rate. respiratory system: the group of organs responsible for carrying oxygen from the air to the bloodstream, and for expelling carbon dioxide. resting tremor: a tremor of a limb that increases when the limb is at rest. retching: dry vomiting. retina: the light-sensitive nerve layer that lines the back of the eye. The retina sense light and creates impulses that are sent through the optic nerve to the brain. retinal detachment: separation of the retina from the epithelium layer and from blood supply. retinopathy: diabetic eye disease. retrolisthesis: posterior slippage of one vertebra onto another. retropulsion: the tendency to step backwards if bumped from the front or upon initiating walking; usually seen in patients who tend to lean backwards because of problems with balance. Reye syndrome: A potentially fatal disease that causes severe problems with the brain and other organs. Although the exact cause of the disease is not known, there has been an association with giving aspirin to children and developing the disease. It is now advised not to give aspirin to children during illnesses, unless prescribed by your child’s physician. rheumatic fever: a childhood disease that may damage the heart valves or the outer lining of the heart. rheumatoid arthritis: an inflammatory disease that involves the lining of the joint (synovium). The inflam-
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1829
mation often affects the joints of the hands and the feet and tends to occur equally on both sides of the body. rheumatoid factor: special kind of antibody often found in people with rheumatoid arthritis. rhinitis: an inflammation of the mucous membrane that lines the nose, often due to an allergy to pollen, dust, or other airborne substances, which causes sneezing, itching, runny nose, and nasal congestion. rhinoplasty: the surgical repair of a defect of the nose, including reshaping or resizing the nose. Rhinoplasty may be performed to change the size of the nose, change the shape of the nose, narrow the nostrils, and/or change the angle between the nose and lips. Rhinoplasty involves the resculpting of the bone and cartilage. rhytidectomy (also called facelift): a surgical procedure that involves the removal of excess facial fat, the tightening of facial muscles, and the stretching of facial skin: to approximate a smoother, firmer appearance. The procedure takes place on either the face, neck, or both. R.I.C.E. (Rest, Ice, Compression, and Elevation): treatment plan for acute injury to prevent inflammatory processes from becoming uncontrolled and to speed up the recovery process by eliminating swelling; acute injury management. rigidity: increased resistance to the passive movement of a limb. ringworm: a fungal skin infection characterized by ring-shaped, red, scaly, or blistery patches. risk factor: activity or factor that may increase the chance of developing a disease. rooting: when a newborn turns his/her head toward touch near the mouth. rosacea: a common skin condition characterized by redness, pimples, and broken blood vessels. rotator cuff: muscles and tendons that form a cuff over the shoulder joint and attach the scapula to the bone in the upper arm (humerus); major function is to control and produce rotation of the shoulder. round window: membrane separating the middle ear and inner ear. rubella (also called German measles): an acute viral infection that causes a mild illness in children and slightly more severe illness in adults. The disease is spread person-to-person through airborne particles and takes two to three weeks to incubate. rupture: break or tear in any organ or soft tissue. Saethe-Chotzen: A birth defect characterized by an unusually short or broad head. In addition, the eyes
1830
Glossary
may be spaced wide apart and have droopy eyelids, and fingers may be abnormally short and webbed. safe sex: sex in a monogamous relationship where neither party is infected with a sexually transmitted disease or urinary tract infection is considered to be “safe.” However, many healthcare professionals believe there really is no such thing as “safe” sex, and the only way to be truly safe is to abstain as all forms of sexual contact carry some risk. salicylic acid: a keratolytic drug (a drug that removes the outer layer of skin) that is used to treat various skin conditions. saline solution: a solution containing sodium chloride. saliva: mixture of water, protein, and salts that makes food easy to swallow and begins digestion. salmonella: bacterium that may cause intestinal infection and diarrhea. salmonella infections: diarrheal infections caused by the bacteria Salmonella. There are many kinds of Salmonella bacteria that cause diarrheal illnesses in humans. salpingectomy: surgical removal of one or both fallopian tubes. salpingo-oophorectomy: surgery to remove the fallopian tubes and ovaries. sarcoidosis: condition that causes small, fleshy swellings in the tissue around the organs, usually in the liver, lungs, and spleen. saturated fat: fat that is found in foods from animal meats and skin, dairy products, and some vegetables. scabies: an infestation of mites in the skin characterized by small pimples that itch. scales: dead skin cells that look like flakes or dry skin. scar: the body’s natural way of healing and replacing lost or damaged skin. A scar is usually composed of fibrous tissue. Scars may be formed for many different reasons, including as a result of infections, surgery, injuries, or inflammation of tissue. Schiller test: A diagnostic test in which the cervix is coated with an iodine solution to detect the presence of abnormal cells. schizoid personality disorder: persons with this disorder are often cold, distant, introverted, and have an intense fear of intimacy. Persons with schizoid personality disorder are often too absorbed in their own thinking and daydreaming that they exclude themselves from attachment with persons and reality. schizophrenia: one of the most complex of all mental health disorders; involves a severe, chronic, and disabling disturbance of the brain.
schizotypal personality disorder: similar to schizoid personality disorder, persons with this disorder are often cold, distant, introverted, and have an intense fear of intimacy and closeness. Yet, with schizotypal personality disorder, persons also exhibit disordered thinking, perception, and ineffective communication skills. Many symptoms of schizotypal personality disorder resemble schizophrenia, but are less mild. sciatica (also called lumbar radiculopathy): a pain that originates along the sciatic nerve. sclera: the white, visible portion of the eyeball. The muscles that move the eyeball are attached to the sclera. scleroderma: a very serious disease of the body’s connective tissue that causes thickening and hardening of the skin. sclerosing adenosis: a benign breast condition that involves excessive growth of tissues in the breast’s lobules, often resulting in breast pain. sclerotherapy: method of stopping upper gastrointestinal (GI) bleeding. A needle is inserted through an endoscope to administer hardening agents to the location that is bleeding. scoliosis: a lateral, or sideways, curvature and rotation of the back bones (vertebrae), giving the appearance that the person is leaning to one side. scotoma: an area of partial or complete loss of vision surrounded by an area of normal vision. screening mammogram: an x-ray of the breast used to detect breast changes in women who have no signs of breast cancer. scrotum: the bag of skin that holds the testicles. seasonal affective disorder (SAD): a mood disorder characterized by depression related to a certain season of the year: especially winter. sebaceous glands: glands in the skin that secrete oil to the surface of the skin. seborrheic keratosis: flesh-colored, yellow, brown, or black wart-like spots. sebum: oily substance produced by sebaceous glands in the skin. secondary tumor: a tumor that forms as a result of spread (metastasis) of cancer from the location where it originated. secretin: hormone made in the duodenum that causes the stomach to produce pepsin, the liver to make bile, and the pancreas to produce a digestive juice. segmental mastectomy: surgery to remove a portion of the breast. segmentation: process by which muscles in the intestines move food and wastes through the body.
seizure: occurs when part(s) of the brain receives a burst of abnormal electrical signals that temporarily interrupts normal electrical brain function. self-monitoring blood glucose: method for people with diabetes to find out how much glucose is in their blood. sella turcica: bony structure that houses the pituitary gland. sensorineural hearing loss: hearing loss caused by damage to the sensory cells and/or nerve fibers of the inner ear. sepsis: the presence of bacteria, virus, fungus, or other organism in the blood or other tissues and the toxins associated with the invasion. septal defect: a hole in the wall of the heart. septoplasty: the surgical correction of defects and deformities of the nasal septum (the partition between the nostrils). septum: the muscle wall that divides the heart chambers. serology: the study of blood serum (the clear fluid that separates when blood clots). serotonin: a chemical necessary for communication between nerve cells. serum: a clear fluid that separates when blood clots. sexually transmitted disease (STD): infection spread through sexual intercourse and other intimate sexual contact. shigellosis: infection with the bacterium Shigella, usually causing a high fever, acute diarrhea, and dehydration. shin splints: damage to one of two groups of muscles along the shin bone that cause pain. shock: impaired body function due to blood loss or a disturbance in the circulatory system. short bowel syndrome (also called short gut syndrome): problems related to absorbing nutrients after removal of part of the small intestine. shunt: a connector to allow blood flow between two locations. Shwachman’s syndrome: Digestive and respiratory disorder of children in which certain digestive enzymes are missing and white blood cells are few. sialorrhea: drooling. sickle cell anemia: an inherited blood disorder characterized by defective hemoglobin. sigmoid colon: lower part of the colon that empties into the rectum. sigmoidoscopy: a diagnostic procedure that allows the physician to examine the inside of a portion of the large intestine, and is helpful in identifying the causes
Glossary
1831
of diarrhea, abdominal pain, constipation, abnormal growths, and bleeding. A short, flexible, lighted tube, called a sigmoidoscope, is inserted into the intestine through the rectum. The scope blows air into the intestine to inflate it and make viewing the inside easier. sign language: language of hand shapes, facial expressions, and movements used as a form of communication. silent ischemia: ischemia not accompanied by chest pain. simple mastectomy: surgical removal of the breast and possibly a few of the axillary lymph nodes close to the breast. sinus node: the cells that produce the electrical impulses that cause the heart to contract. sinuses: air cavities within the facial bones, lined by mucous membranes similar to those in other parts of the airways. sinusitis: inflammation of the membranes lining the facial sinuses, often caused by bacterial or viral infection, or allergic reaction. skilled nursing facility (SNF): an out-of-home care option for elderly persons who require continuous nursing care. SNFs can provide extensive care services, such as intravenous feedings, blood pressure monitoring, medication injections, and care for patients on ventilators. skin (cutaneous) diphtheria: one type of diphtheria; the symptoms are usually milder and may include yellow spots or sores (similar to impetigo) on the skin. skin cancer: a malignant tumor that grows in the skin cells. skin grafts: a skin graft may be used to cover skin that has been damaged and/or is missing. This surgical procedure involves removing healthy portions of skin from one part of the body to restore normal appearance and/or function to another portion of the same body. The location where the skin is removed is called the donor site. There are various types of skin grafts that may be utilized, depending upon the size and location of needed skin. skin tags: soft, small, flesh-colored skin flaps on the neck, armpits, or groin. small intestine: the digestive tract between the stomach and the large intestine. Most of digestion occurs here as nutrients are absorbed from food. smallpox: a highly contagious disease caused by a type of poxvirus; symptoms usually include a fever and a blistery-like rash. smell: to perceive odor or scent through stimuli affecting the olfactory nerves.
1832
Glossary
smell disorder: inability to perceive odors that may be temporary or permanent. smooth muscle: muscle that performs automatic tasks, such as constricting blood vessels. social phobia: an anxiety disorder in which a person has significant anxiety and discomfort related to a fear of being embarrassed, humiliated, or scorned by others in social or performance situations. soft tissues: the ligaments, tendons, and muscles in the musculoskeletal system. somatosensory: refers to sensory signals from all tissues of the body including skin, viscera, muscles, and joints. somatostatin: hormone in the pancreas that helps tell the body when to make the hormones insulin, glucagon, gastrin, secretin, and renin. sound vocalization: ability to produce voice. spasm: a condition in which a muscle or group of muscles involuntarily contract. spasmodic dysphonia: momentary disruption of voice caused by involuntary movements of one or more muscles of the larynx (voice box). spasms: muscle movements such as those in the colon that cause pain, cramps, and diarrhea. spasticity: increased muscle tone that results in a tightening and shortening of a muscle. specific language impairment (SLI): difficulty with the organized symbol-system communication in the absence of problems such as mental retardation, hearing loss, or emotional disorders. specific phobia: a type of phobia characterized by extreme fear of an object or situation that is not harmful under general conditions. speech: making definite vocal sounds that form words to express thoughts and ideas. speech disorder: defect or abnormality that prevents an individual from communicating by means of spoken words. speech processor: part of a cochlear implant that converts speech sounds into electrical impulses to stimulate the auditory nerve. speech-language pathologist: professional trained to evaluate and treat people who have voice, speech, language, or swallowing disorders, including hearing impairment, that affect their ability to communicate. sperm disorders: problems with the production and maturation of sperm; the single most common cause of male infertility. Sperm may be immature, abnormally shaped, unable to move properly, or, normal sperm may be produced in abnormally low numbers (oligospermia).
SPF: Sun Protection Factor. sphincter: ring-like band of muscle that opens and closes an opening in the body. sphincter muscles: circular muscles that help keep urine from leaking by closing tightly like a rubber band around the opening of the bladder. sphincter of Oddi: muscle between the common bile duct and pancreatic ducts. sphincterotomy: a procedure to open the muscle sphincter: a ring of muscle around a natural opening that acts like a valve: wide enough so stones can pass into the intestine. sphygmomanometer: the instrument used to measure blood pressure. spider angioma: a bright red mark with a distinct dark spot in the skin. spinal anesthesia: injection of an anesthetic into the area around the spinal cord to block pain sensation during surgery. spinal cord: a bundle of nerves that carries messages between the brain and the rest of the body. spinal instability: increased motion between vertebra, usually resulting from an injury; pain typically feels like tingling in the neck or arms. spinal stenosis: narrowing of the nerve openings either around the spinal cord or nerve roots that can cause symptoms similar to a pinched nerve; pain is described either as an aching or an electrical feeling down the arm. spinal tap (also called lumbar puncture): a special needle is placed into the lower back, into the spinal canal. This is the area around the spinal cord. The pressure in the spinal canal and brain can then be measured. A small amount of cerebral spinal fluid (CSF) can be removed and sent for testing to determine if there is an infection or other problems. CSF is the fluid that bathes the brain and spinal cord. spine: a column in the body consisting of 33 vertebrae. spirogram: a record of the amounts of air being moved in and out of the lungs. spirometer: an instrument that measures the amount of air moved in and out of the lungs (the amount of inhaled and exhaled air). spirometry: a pulmonary test of the lungs using a spirometer. spleen: organ that cleans blood and makes white blood cells. splenectomy: surgical removal of the spleen. splenic flexure syndrome: condition that occurs when air or gas collects in the upper parts of the colon.
splints: a device for preventing movement of a joint or holding in place any part of the body. spondylitis: inflammation of the spine. spondylolisthesis: forward displacement of one vertebra on its lower neighbor. spondylosis: a degenerative process of the cervical spine that causes narrowing of the spinal canal and neural foramina, and produces compression of the spinal cord and nerve roots. sporadic: occurring by chance. sprain: a partial or complete tear of a ligament. sputum (also called phlegm): mucus from the lungs. squamous cell cancer: a slow-growing cancer in cells in the top layer of the skin. squamous cell carcinoma: a form of skin cancer that affects about 20 percent of patients with skin cancer. This highly treatable cancer is characterized by red, scaly skin that becomes an open sore. squamous cells (also called keratinocytes): the primary cell types found in the epidermis, the outer layer of skin. squamous intraepithelial lesion (SIL): a term used to classify the degree of precancerous change in cells of the cervix in a condition called cervical dysplasia. stage: the extent of a cancer; whether the disease has spread from the original site to other bosy parts. staging: an evaluation of the extent of disease that provides the basis for making treatment recommendations. steatorrhea: condition in which the body cannot absorb fat. stem cell transplantation: removing stem cells from the patient’s or a donor’s bone marrow and re-infusing them into the patient to help produce healthy blood cells; a method of replacing stem cells which are destroyed by cancer treatment. stem cells: the blood cells that produce other blood cells. It is the stem cells that are needed in bone marrow transplantation. stenosis: the narrowing or constriction of a blood vessel or valve in the heart. stent: a device implanted in a vessel used to help keep it open. stereopsis: ability to perceive three-dimensional depth. sternum: the breastbone. stethoscope: the instrument used to listen to the heart and other sounds in the body. stirrups: technique of ankle strapping using rigid tape placed on the ankle, medial to lateral adhering to the undersurface of the heel, mimicking a stirrup.
Glossary
1833
stoma: a surgically created opening in an organ. stomach: organ between the esophagus and the small intestine. The stomach is where digestion of protein begins. stomach ulcer (also called a gastric ulcer): open sore in the stomach lining. stool (also called feces): solid wastes that pass through the rectum as bowel movements. Stools are undigested foods, bacteria, mucus, and dead cells. stork bite (also called salmon patch): small pink or red patches often found on a baby’s eyelids, between the eyes, upper lip, and back of the neck. straight leg raise (SLR): technique for measuring sciatic nerve mobility and/or hamstring length. strain: a tear of a muscle or tendon. strawberry hemangioma: a bright or dark red, raised or swollen, bumpy area on the skin of a baby or child. streptokinase: a clot-dissolving medication. stress: mental or physical tension that results from physical, emotional, or chemical causes. stress fractures: weak spots or small cracks in the bone caused by continuous overuse. stress incontinence: the most common type of incontinence that involves the leakage of urine during exercise, coughing, sneezing, laughing, lifting heavy objects, or other body movements that put pressure on the bladder. stress ulcer: upper gastrointestinal (GI) ulcer from physical injury such as surgery, major burns, or critical head injury. striatum: part of the basal ganglia; a large cluster of nerve cells, consisting of the caudate nucleus and the putamen, that controls movement, balance, and walking; the neurons of the striatum require dopamine to function. stricture (also called stenosis): abnormal narrowing of a body opening. stroke (also called brain attack): occurs when brain cells die because of inadequate blood flow to the brain. stuttering: frequent repetition of words or parts of words that disrupts the smooth flow of speech. subarachnoid hemorrhage: a stroke that occurs when a blood vessel on the surface of the brain ruptures and bleeds into the space between the brain and the skull (but not into the brain itself ). subchondral tissue: the smooth tissue at the ends of bones, which is covered with another type of tissue called cartilage. subcutis (also called subcutaneous layer): the deepest layer of skin.
1834
Glossary
substantia nigra: a small area of the brain containing a cluster of black-pigmented nerve cells that produce dopamine, which is then transmitted to the striatum. subtotal or partial gastrectomy: surgical removal of a portion of the stomach. sudden deafness: loss of hearing that occurs quickly from such causes as explosion, a viral infection, or the use of some drugs. sudden death: death that occurs unexpectedly or immediately after onset of symptoms. sudden infant death syndrome (SIDS): unexplained, sudden death of an infant up to 1 year of age. suicide: the intentional taking of one’s own life. sunburn: a visible reaction of the skin to overexposure to the sun’s invisible ultraviolet (UV) rays. sunscreen: a product that protects the skin again sunburns by blocking the penetration of the sun’s ultraviolet (UV) rays. superior vena cava: the large vein that returns blood to the heart from the head and arms. suprarenal glands: another name for the adrenal glands. surgery: operation to remove or repair a part of the body, or to determine if disease is present. suspensory ligament of lens: a series of fibers that connect the ciliary body of the eye with the lens, holding it in place. sustention (postural) tremor: a tremor of a limb that increases when the limb is stretched. swallowing disorders: any of a group of problems that interfere with the transfer of food from the mouth to the stomach. synapse: a tiny gap between the ends of nerve fibers across which nerve impulses pass from one neuron to another; at the synapse, an impulse causes the release of a neurotransmitter, which diffuses across the gap and triggers an electrical impulse in the next neuron. syncope: light-headedness or fainting caused by insufficient blood supply to the brain. syndactyly: a congenital problem characterized by a union of fingers or toes. syndromic hearing impairment: hearing loss or deafness that is inherited or passed through generations of a family. synovial fluid: a clear, sticky fluid that is released by the synovial membrane and acts as a lubricant for joints and tendons. synovial membrane: a tissue that lines and seals the joint. synovitis: inflammation of the synovial membrane, the tissue that lines and protects the joint.
synovium: a fibrous envelope that produces a fluid to help to reduce friction and wear in a joint. syphilis: a sexually transmitted disease caused by Treponema pallidum bacteria. The initial symptom of syphilis is a painless open sore that usually appears on the penis or around or in the vagina. If untreated, syphilis may go on to more advanced stages, including a transient rash and, eventually, serious involvement of the heart and central nervous system. syrup of ipecac: an emetic made from the dried root of a plant called ipecacuanha, which is grown in Brazil. An emetic is an agent that causes vomiting. systemic: disease or symptoms that affect many different parts of the body. systemic chemotherapy: chemotherapy taken by pill or needle injection into a vein or muscle. systemic juvenile rheumatoid arthritis: a form of juvenile rheumatoid arthritis that affects joints and, sometimes, internal organs. systemic lupus erythematosus (also called SLE or lupus): a very serious, chronic, autoimmune disorder characterized by periodic episodes of inflammation of and damage to the joints, tendons, other connective tissues, and organs, including the heart, lungs, blood vessels, brain, kidneys, and skin. systemic treatment or therapy: treatment or therapy that reaches and affects cells throughout the body. systolic blood pressure: the highest pressure to which blood pressure rises with the contraction of the ventricles. tachycardia: rapid heartbeat. tachypnea: rapid breathing. tamoxifen: a drug used in hormone therapy to treat breast cancer by blocking the effects of estrogen. taste: sensation produced by a stimulus applied to the gustatory nerve endings in the tongue; the four tastes are salt, sour, sweet, and bitter; some say there is a fifth taste described as savory. taste buds: groups of cells located on the tongue that enable one to recognize different tastes. taste disorder: inability to perceive different flavors. telemetry unit: a small transmitter that is used to send information about the heart via radio transmission to healthcare professionals for evaluation. temporal arteries: vessels located over the temples on each side of the head, that supply blood to part of the head. temporomandibular joints (TMJ): the two joints that connect the jaw to the skull. tendon: the tough cords of tissue that connect muscles to bones.
tendonitis: an inflammation in a tendon or the tendon covering. tenesmus: straining to have a bowel movement. tennis elbow (also called lateral epicondylitis): an injury to the tendons on the lateral portion of the elbow that bend the wrist backward away from the palms of the hands. testicular cancer: cancer that develops in a testicle. testis: one of the pair of male gonads that produce semen. testosterone: male sex hormone produced mostly by the testicles, which stimulates bone and muscle growth and the development of male sex characteristics. tetanus: an acute, sometimes fatal, disease of the central nervous system; caused by the toxin of the tetanus bacterium, which usually enters the body through an open wound. The tetanus bacterium live in soil and manure, but also can be found in the human intestine and other places. thalassemia: an inherited blood disorder in which the chains of the hemoglobin (a type of protein in red blood cells that carries oxygen to the tissues) molecule are abnormal; alpha thalassemia results when a mutation occurs in the alpha chain, while beta thalassemia results when the mutation occurs in the beta chain; signs and symptoms of thalassemias vary from mild (little to no symptoms) to severe (life threatening). thallium stress test: a study in which a radioactive substance is carried by the blood and its progress through the circulation of a specific body area is followed by x-ray pictures. thermal burns: burns due to external heat sources which raise the temperature of the skin and tissues and cause tissue cell death or charring. Hot metals, scalding liquids, steam, and flames, when coming in contact with the skin, cause thermal burns. thoracic spine: the 12 vertebrae between the cervical and lumbar spines that provide attachments for the ribs. thoracotomy: surgery to view the lung that may be used to confirm cancer, or for chest trauma to detect the source of bleeding. throat disorders: disorders or diseases of the larynx (voice box) or esophagus. thrombolysis: the breaking up of a blood clot. thrombolytic therapy: the use of a medication that dissolves blood clots. thrombosis: excess clotting which obstructs veins (venous thrombosis) and arteries (arterial thrombosis). thrombosis, deep-vein: formation of blood clots in veins deep inside the legs.
Glossary
1835
thrombus: a blood clot. thyroid scan: uses a radioactive substance to create an image of the thyroid as it is functioning. thyroplasty (also known as laryngeal framework surgery): surgical technique to improve voice by altering the cartilages of the larynx. thyroxine (T4): a hormone secreted by the thyroid gland which regulates metabolism. triiodothyronine (T3): a hormone secreted by the thyroid gland which regulates metabolism. tibia: shin bone or larger bone of the lower leg. tinea versicolor: a common fungal skin infection characterized by white or light brown patches on the skin. tinnitus: sensation of a ringing, roaring, or buzzing sound in the ears or head; often associated with various forms of hearing impairment. tissue: group or layer of cells that together perform specific functions. tissue expansion: a surgical procedure that involves inserting a balloon-like device (called an expander) under the skin. The expander then slowly secretes liquid into the area to be repaired to actually stretch and expand the skin. This serves the function of “growing” extra skin to repair nearby lost or damaged skin. tissue plasminogen activator (TPA): a medication used to dissolve blood clots. tomography: from the Greek words “to cut or section” (tomos) and “to write” (graphein), in nuclear medicine, it is a method of separating interference from the area of interest by imaging a cut section of the object. tongue: large muscle on the floor of the mouth that manipulates food for chewing and swallowing; the main organ of taste, and helps form speech sounds. tonometry: test to measure intraocular pressure for glaucoma. topical chemotherapy: chemotherapy given as a cream or lotion placed on the skin to kill cancer cells. torticollis (also called wryneck): a twisting of the neck that causes the head to rotate on an angle. total (or simple) mastectomy: surgery to remove the entire breast (including the nipple, areola, and most of the overlying skin) and may also remove some of the lymph nodes under the arm, also called the axillary lymph glands. total hysterectomy: the surgical removal of the uterus, including the cervix; the fallopian tubes and the ovaries remain. total hysterectomy with bilateral salpingo-oophorectomy: the entire uterus, fallopian tubes, and the ovaries are surgically removed.
1836
Glossary
Tourette’s syndrome: Neurological disorder characterized by tics and other movements such as eye blinks or facial twitches that cannot be controlled. toxic epidermal necrolysis: a life-threatening skin disorder characterized by blistering and peeling of the top layer of skin. toxoplasmosis: an infection caused by a parasite that can lead to serious illness or death in the fetus. tracheoesophageal fistula (TEF): condition that occurs when there is a gap between the upper and lower segments of the esophagus, and food and saliva cannot pass through. tracheostomy: surgical opening into the trachea (windpipe) to help someone breathe who has an obstruction or swelling in the larynx (voice box) or upper throat. trans fat: vegetable oil that has been treated with hydrogen in order to make it more solid and give it a longer shelf life. transcutaneous electrical nerve stimulation (TENS): a method of providing pain relief using electrical signals which are sent to the nerve endings. transesophageal echocardiography (TEE): a diagnostic test that is used to measure the sound waves that bounce off of the heart. transferrin saturation test (TS): a type of iron study (blood test) that measures the percentage of transferrin and other mobile, iron-binding proteins saturated with iron. transient ischemic attack (TIA): a stroke-like event that lasts for a short period of time and is caused by a blocked blood vessel. transplantation: replacing an organ. transrectal ultrasound of the prostate: a test using sound wave echoes to create an image of an organ or gland to visually inspect for abnormal conditions such as gland enlargement, nodules, penetration of tumor through capsule of the gland, and/or invasion of seminal vesicles. It may also be used for guidance of needle biopsies of the prostate gland and guiding the nitrogen probes in cryosurgery. transurethral hyperthermia: an investigative procedure that uses heat, usually provided by microwaves, to shrink the prostate. transurethral incision of the prostate (TUIP): a procedure that widens the urethra by making some small cuts in the bladder neck, where the urethra joins the bladder, and in the prostate gland itself. transurethral laser incision of the prostate (TULIP): the use of laser through the urethra that melts the tissue.
transurethral resection of the prostate (TURP): a surgical procedure by which portions of the prostate gland are removed through the penis. transurethral surgery: surgery in which no external incision is needed. For prostate transurethral surgery, the surgeon reaches the prostate by inserting an instrument through the urethra. transvaginal ultrasound (also called ultrasonography): an ultrasound test using a small instrument, called a transducer, that is placed in the vagina. transverse colon: part of the colon that extends across the abdomen from right to left. transverse frictions: deep massage technique used for tendon and ligament conditions. transverse myelitis: inflammation and swelling along the spinal cord with motor or sensory nerve dysfunction. trauma: a physical injury or wound caused by an external force of violence, which may cause death or permanent disability. Trauma is also used to describe severe emotional or psychological shock or distress. travel medicine: a specialized area of healthcare that focuses on the needs of travelers, particularly those who travel to other countries. traveler’s diarrhea: a term used to describe diarrhea caused by infection with bacteria, protozoa, or viruses ingested by consuming food or water that has been contaminated. Two life-threatening types of traveler’s diarrhea are caused by cholera and giardiasis. tremor: a rhythmical shaking of a limb, head, mouth, tongue, or other part of the body. tretinoin: a drug which is chemically related to vitamin A; used to treat acne and other scaly skin disorders. trichomoniasis: very common type of vaginitis caused by a single-celled organism usually transmitted during sexual contact. trichotillomania: a disorder characterized by recurrent, compulsive hair pulling. tricuspid valve: the heart valve that controls blood flow from the right atrium into the right ventricle. trigger finger: an irritation of the digital sheath that surrounds the flexor tendons of the finger. When the tendon sheath becomes thickened or swollen, it pinches the tendon and prevents it from gliding smoothly. In some cases, the tendon catches and then suddenly releases as though a trigger were released. trigger point: hypersensitive area or site in muscle or connective tissue, usually associated with myofascial pain syndromes. triglyceride: a fat-like substance found in the blood.
trimester: a pregnancy is divided into phases, each lasting about three months. trimester: period of three months. tropical sprue: condition of unknown cause. Abnormalities in the lining of the small intestine prevent the body from absorbing food normally. tubal ligation: surgical sterilization procedure in which the fallopian tubes are sealed or cut to prevent sperm from reaching an egg. tube feeding (also called enteral nutrition): a way to provide food through a tube placed in the nose, stomach, or small intestine. A tube in the nose is called a nasogastric or nasoantral tube. A tube that goes through the skin into the stomach is called a gastrostomy or percutaneous endoscopic gastrostomy (PEG). A tube into the small intestine is called a jejunostomy or percutaneous endoscopic jejunostomy (PEJ) tube. tuberculosis (TB): an infectious disease that was once a major killer worldwide. The predominant TB organism is Mycobacterium tuberculosis (M. tuberculosis). Spread person-to-person in airborne droplets caused by sneezing or coughing, the bacteria usually infects the lungs. However, due to improved nutrition, housing, sanitation, medical care, and the introduction of antibiotics this century, reported TB cases in the U.S. have declined dramatically. tumor: an abnormal lump or mass of tissue. Tumors can be benign (non-cancerous) or malignant (cancerous). tunica vaginalis: a thin pouch that holds the testes within the scrotum. tunnel surgery (also called percutaneous nephrolithotomy): a small cut is made in the patient’s back and a narrow tunnel is made through the skin to the stone inside the kidney. The physician can remove the stone through this tunnel. tympanometry: a test that allows for air and sound to be directed into the middle ear. tympanoplasty: surgical repair of the eardrum (tympanic membrane) or bones of the middle ear. type 1 diabetes: a condition in which the body’s immune system destroys the cells in the pancreas that produce insulin. Insulin allows glucose to enter the cells of the body to provide energy. Persons with type 1diabetes must take daily insulin injections. type 2 diabetes: a condition in which the body either makes too little insulin or cannot properly use the insulin it makes to convert blood glucose to energy. Type 2 diabetes may be controlled with diet, exercise, and weight loss, or may require oral medications and/ or insulin injections.
Glossary
1837
typhoid fever: a life-threatening bacterial infection caused by the bacterium Salmonella Typhi (S. Typhi); often transmitted by contaminated water, food, or milk. tyrosine: the amino acid from which dopamine is made. ulcer: sore on the skin surface or on the stomach lining. ulcerative colitis: a serious disease that causes ulcers and irritation in the inner lining of the colon and rectum. ulnar bone: the longer of the two bones in the forearm. ultrasound (also called sonography): a diagnostic imaging technique which uses high-frequency sound waves and a computer to create images of blood vessels, tissues, and organs. Ultrasounds are used to view internal organs as they function, and to assess blood flow through various vessels. ultraviolet radiation: invisible rays that come from the sun. Ultraviolet radiation can damage the skin and cause melanoma and other types of skin cancer. umbilical cord: a rope-like cord connecting the fetus to the placenta. The umbilical cord contains two arteries and a vein, which carry oxygen and nutrients to the fetus and waste products away from the fetus. umbilical cord blood transplant: a procedure in which stem cells are taken from an umbilical cord immediately after delivery of an infant. umbilical hernia: a weakness in the abdominal muscles. unilateral: affecting one side of the body. For example, unilateral kidney cancer occurs in one kidney only. upper GI (gastrointestinal) series (also called barium swallow): a diagnostic test that examines the organs of the upper part of the digestive system: the esophagus, stomach, and duodenum (the first section of the small intestine). A fluid called barium (a metallic, chemical, chalky, liquid used to coat the inside of organs so that they will show up on an x-ray) is swallowed. X-rays are then taken to evaluate the digestive organs. urea: the nitrogen part of urine produced from the breakdown of protein. urea breath test: test used to detect Helicobacter pylori (H. pylori) infection. The test measures breath samples for urease, an enzyme H. pylori produces. ureterocele: the portion of the ureter closest to the bladder becomes enlarged because the ureter opening is very tiny and obstructs urine outflow; urine backs up in the ureter tube.
1838
Glossary
ureteroscope: an optical device which is inserted into the urethra and passed up through the bladder to the ureter; to inspect the opening of the ureters. ureters: two narrow tubes that carry urine from the kidneys to the bladder. urethra: narrow channel through which urine passes from the bladder out of the body. urethritis: an infection limited to the urethra. urge incontinence: the inability to hold urine long enough to reach a restroom. It is often found in people who have conditions such as diabetes, stroke, dementia, Parkinson’s disease, and multiple sclerosis, but may be an indication of other diseases or conditions that would also warrant medical attention. urgent surgery (also called emergency surgery): an operation performed immediately as a result of an urgent medical condition. urinalysis: laboratory examination of urine for various cells and chemicals, such as red blood cells, white blood cells, infection, or excessive protein. urinary incontinence: the loss of bladder control. urinary retention: the inability to empty the bladder. urinary tract infection (UTI): an infection that occurs in the urinary tract; often caused by bacteria such as Escherichia coli. A urinary tract infection often causes frequent urination, pain, and burning when urinating, and blood in the urine. urine flow study: a test in which the patient urinates into a special device that measures how quickly the urine is flowing. A reduced flow may suggest benign prostatic hyperplasia(BPH). urogenital: refers to the urinary and reproductive systems. urology: the branch of medicine concerned with the urinary tract in both genders, and with the genital tract or reproductive system in the male. urticaria (also called hives): a condition in which red, itchy, and swollen areas appear on the skin: usually as an allergic reaction from eating certain foods or taking certain medications. urushiol: resin in poison ivy plants that causes an allergic skin reaction. Usher’s syndrome: A hereditary disease that affects hearing and vision. uterine wall: the wall of the uterus. uterus (also called the womb): a hollow, pear-shaped organ located in a woman’s lower abdomen, between the bladder and the rectum, that sheds its lining each month during menstruation and in which a fertilized egg (ovum) becomes implanted and the fetus develops.
vacuum aspiration: procedure in which a suction tube attached to a vacuum pump is inserted through the vagina into the uterus to loosen and remove its contents. vacuum extraction: procedure used to ease delivery by applying a metal or plastic cup to the baby’s scalp and using suction to pull the baby gradually out of the vagina. vagina (also called the birth canal): the passageway through which fluid passes out of the body during menstrual periods. The vagina connects the cervix (the opening of the womb, or uterus) and the vulva (the external genitalia). vaginal atrophy: often a symptom of menopause; the drying and thinning of the tissues of the vagina and urethra. This can lead to dyspareunia (pain during sexual intercourse) as well as vaginitis, cystitis, and urinary tract infections. vaginal hysterectomy: the uterus is removed through the vaginal opening. vaginitis: inflammation, redness, or swelling of the vaginal tissues; usually resulting from a bacterial infection. vaginitis, atrophic: a form of noninfectious vaginitis which usually results from a decrease in hormones because of menopause, surgical removal of the ovaries, radiation therapy, or even after childbirth: particularly in breastfeeding women. Lack of estrogen dries and thins the vaginal tissue, and may also cause spotting. vaginitis, bacterial: very common vaginal infection characterized by symptoms such as increased vaginal discharge or itching, burning, or redness in the genital area. vaginitis, noninfectious: a type of vaginitis that usually refers to vaginal irritation without an infection being present. Most often, the infection is caused by an allergic reaction to, or irritation from, vaginal sprays, douches, or spermicidal products. It may also be caused by sensitivity to perfumed soaps, detergents, or fabric softeners. vaginitis, viral: very common vaginal infection, often sexually transmitted, that is caused by one of many different types of viruses. vagotomy: operation to cut the vagus nerve, which causes the stomach to produce less acid. vagus nerve: nerve in the stomach that controls the production of stomach acid. valgus deformity: a lateral inclination of a distal bone of a joint from the midline. valve: fold in the lining of an organ that prevents fluid from flowing backward.
valves: the “doors” between the chambers of the heart. The heart valves are tricuspid, pulmonic, mitral, and aortic. valvuloplasty: the repair of a heart valve using a balloon catheter inside the valve. varices: stretched veins such as those that form in the esophagus from cirrhosis. varicose veins: enlarged, curving veins just beneath the skin, usually in the legs. varus deformity: a medial inclination of a distal bone of a joint from the midline. vas deferens: the tubes leading to the testes. vasculitis: inflamed blood vessels. vasectomy: a surgical procedure performed to make a man sterile, or unable to father a child. It is a permanent male birth control measure, and a means of contraception used in many parts of the world. vasodepressors: medication that raises blood pressure. vasodilator: a medication that dilates or widens the opening in a blood vessel. vein: a blood vessel that carries blood from the body back into the heart. velocardiofacial syndrome: inherited disorder characterized by cleft palate, heart defects, characteristic facial appearance, minor learning problems, and speech and feeding problems. venipuncture: drawing blood with a needle from a vein usually in the forearm. ventilation: movement of air (gases) in and out of the lungs. ventricle: one of the two pumping chambers of the heart; right ventricle receives oxygen-poor blood from the right atrium and pumps it to the lungs through the pulmonary artery; left ventricle receives oxygen-rich blood from the left atrium and pumps it to the body through the aorta. ventricular fibrillation: a condition in which the ventricles contract in rapid and unsynchronized rhythms and cannot pump blood into the body. ventricular tachycardia: a condition in which the ventricles cause a very fast heartbeat. vernix caseosa (also called vernix): a white substance that covers the skin of the fetus (while inside the uterus) and helps to protect the fetus. vertebrae (also called the back bone): bony structures that surround the spinal cord. vertigo: illusion of movement; sensation that the external world is revolving around an individual (objective vertigo) or that the individual is revolving in space (subjective vertigo).
Glossary
1839
vesicoureteral reflux (VUR): the abnormal flow of urine from the bladder back into the ureters; often as a result of a urinary tract infection or birth defect. vestibular neuronitis: infection at the vestibular nerve. vestibular system: system in the body that is responsible for maintaining the body’s orientation in space, balance, and posture; also regulates locomotion and other movements and keeps objects in visual focus as the body moves. vestibule: bony cavity of the inner ear. vibrotactile aids: mechanical instruments that help individuals who are deaf detect and interpret sound through the sense of touch. villi: tiny, fingerlike projections on the surface of the small intestine that help absorb nutrients. viral hemorrhagic fevers: a term that refers to a group of illnesses caused by several distinct families of viruses. While some of these cause illnesses that are relatively mild, many cause severe, life-threatening diseases with no known cure, such as the Ebola virus. visual acuity: the space visible to an eye in a given position of gaze. vitiligo: smooth, white patches in the skin caused by the loss of pigment-producing cells. vitrectomy: an operation to remove the blood that sometimes collects at the back of the eyes when a person has eye disease. vitreous body: a clear, jelly-like substance that fills the center of the eye. vocal cord paralysis: inability of one or both vocal folds (vocal cords) to move because of damage to the brain or nerves. vocal cords (also called vocal folds): muscularized folds of mucous membrane that extend from the larynx (voice box) wall; enclosed in elastic vocal ligament and muscle that control the tension and rate of vibration of the cords as air passes through them. vocal tremor: trembling or shaking of one or more of the muscles of the larynx resulting in an unsteadysounding voice. voice: sound produced by air passing out through the larynx and upper respiratory tract. volvulus: twisting of the stomach or large intestine. vomiting: the release of stomach contents through the mouth. vulva: external, visible part of the female genital area. vulvitis: an inflammation of the vulva, the soft folds of skin outside the vagina. This is not a condition but rather a symptom that results from a host of diseases, infections, injuries, allergies, and other irritants.
1840
Glossary
Waardenburg syndrome: Hereditary deafness that is characterized by hearing impairment, a white shock of hair, and/or distinctive blue color to one or both eyes, as well as wide-set inner corners of the eyes; balance problems are also associated with some types of Waardenburg syndrome. wart: a non-cancerous skin growth caused by a virus. watermelon stomach: parallel red sores in the stomach that look like the stripes on a watermelon. wedge resection of the lung: a small, localized section of the lung is removed: often for a lung biopsy. white blood cells (also called WBCs or leukocytes): blood cells involved in the destruction of viruses, bacteria, and fungi. white matter: nerve tissue that is paler in color than gray matter because it contains nerve fibers with large amounts of insulating material (myelin). The white matter does not contain nerve cells. In the brain, the white matter lies within the gray layer of the cerebral cortex. whole blood: blood containing all its components, such as red and white blood cells, platelets, and more. Wolff-Parkinson-White syndrome: An extra electrical pathway that connects the atria and ventricles and causes rapid heartbeat. xerostomia: a dry mouth condition; can be caused by a number of things, including rheumatoid arthritis, diabetes, kidney failure, infection with HIV (the virus
that causes AIDS), drugs used to treat depression, and radiation treatment for mouth or throat cancer. x-ray: a diagnostic test which uses invisible electromagnetic energy beams to produce images of internal tissues, bones, and organs onto film. yeast infection (also called Candida): one type of vaginitis caused by the Candida fungus characterized by itching, burning, or redness of the vaginal area. yellow fever: a viral disease that is transmitted by the Aedes aegypti mosquito. Yin and Yang: Chinese words for complementary and opposite forces that make up the life force (Qi). yoga: Indian word for “union.” Yoga is a posturing and breathing technique to induce relaxation. Zenker’s diverticulum: Pouches in the esophagus from pressure in and around the esophagus. Zollinger-Ellison syndrome: Group of symptoms that occur when a tumor called a gastrinoma forms in the pancreas. The tumor releases large amounts of the hormone gastrin, which causes too much acid in the duodenum, resulting in ulcers and bleeding. zygote intrafallopian transfer (ZIFT): method of treating infertility by removing eggs from a woman’s ovaries, fertilizing them in the laboratory with sperm from her partner or a donor, and inserting one or more of the fertilized eggs into one of her fallopian tubes. Rush University Medical Center
Appendix
World Health Organization
Core Health Indicators by Country The information provided in this appendix has been compiled from various sources, mainly national health information bulletins and publications, as well as official publications of WHO and other UN agencies. Data related to each country has been verified and validated by the responsible officials in the Ministries of Health of Member States. All efforts have been madeto collect, compile, analyze and present the most recent data for each specified time period, and to adhere to WHO’s five criteria for statistical reporting: validity, reliability, cross-population comparability, data audit trail and consultation with national authorities. However, the data published in this brochure is subject to some limitations due to the capacity and capability of some national health information systems, as well as differences in definitions, concepts and measurement units. Therefore, caution should be exercised, particularly when using the data for trend analysis or intercountry comparisons.
1841
1842 Appendix
Afghanistan Indicator
Value (year
Life expectancy at birth (years) males
Life expectancy at birth (years) females
42.0 (2004)
Healthy life expectancy (HALE) at birth (years) males
42.0 (2004)
Healthy life expectancy (HALE) at birth (years) females
35.3 (2002)
35.8 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
509 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males
258 (2004)
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
448 (2004)
256 (2004) 6.5 (2003)
26 (2003)
29,863 (2005)
Per capita GDP in international dollars
430 (2004)
Albania Indicator
Value (year)
Life expectancy at birth (years) males Life expectancy at birth (years) females
69.0 (2004)
Healthy life expectancy (HALE) at birth (years) males Healthy life expectancy (HALE) at birth (years) females
74.0 (2004)
59.5 (2002)
63.3 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
171 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
Per capita GDP in international dollars
96 (2004)
19 (2004)
18 (2004) 6.5 (2003) 366 (2003) 3,130 (2005)
6,158 (2004)
Appendix
1843
Algeria Indicator
Value (year)
Life expectancy at birth (years) males
Life expectancy at birth (years) females
69.0 (2004)
Healthy life expectancy (HALE) at birth (years) males
72.0 (2004)
Healthy life expectancy (HALE) at birth (years) females
59.7 (2002)
61.6 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
153 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males
41 (2004)
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
124 (2004)
39 (2004) 4.1 (2003)
186 (2003)
32,854 (2005)
Per capita GDP in international dollars
4,860 (2004)
Andorra Indicator
Value (year)
Life expectancy at birth (years) males Life expectancy at birth (years) females
77.0 (2004)
Healthy life expectancy (HALE) at birth (years) males Healthy life expectancy (HALE) at birth (years) females
83.0 (2004)
69.8 (2002)
74.6 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
108 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
Per capita GDP in international dollars
46 (2004)
7 (2004)
6 (2004) 7.1 (2003) 2,453 (2003) 67 (2005)
36,535 (2004)
1844 Appendix
Angola Indicator
Value (year)
Life expectancy at birth (years) males
Life expectancy at birth (years) females
38.0 (2004)
Healthy life expectancy (HALE) at birth (years) males
42.0 (2004)
Healthy life expectancy (HALE) at birth (years) females
31.6 (2002)
35.1 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
591 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males
276 (2004)
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
504 (2004)
243 (2004) 2.8 (2003)
49 (2003)
15,941 (2005)
Per capita GDP in international dollars
1,942 (2004)
Antigua and Barbuda Indicator
Value (year)
Life expectancy at birth (years) males Life expectancy at birth (years) females
70.0 (2004)
Healthy life expectancy (HALE) at birth (years) males Healthy life expectancy (HALE) at birth (years) females
75.0 (2004)
60.1 (2002)
63.6 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
191 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
Per capita GDP in international dollars
120 (2004)
14 (2004)
10 (2004) 4.5 (2003) 442 (2003) 81 (2005)
10,907 (2004)
Appendix
1845
Argentina Indicator
Value (year)
Life expectancy at birth (years) males
Life expectancy at birth (years) females
71.0 (2004)
Healthy life expectancy (HALE) at birth (years) males
78.0 (2004)
Healthy life expectancy (HALE) at birth (years) females
62.5 (2002)
68.1 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
173 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males
20 (2004)
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
90 (2004)
16 (2004) 8.9 (2003)
1,067 (2003)
38,747 (2005)
Per capita GDP in international dollars
13,331 (2004)
Armenia Indicator
Value (year)
Life expectancy at birth (years) males Life expectancy at birth (years) females
65.0 (2004)
Healthy life expectancy (HALE) at birth (years) males Healthy life expectancy (HALE) at birth (years) females
72.0 (2004)
59.4 (2002)
62.6 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
248 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
Per capita GDP in international dollars
111 (2004)
34 (2004)
30 (2004) 6.0 (2003) 302 (2003) 3,016 (2005)
5,697 (2004)
1846 Appendix
Australia Indicator
Value (year)
Life expectancy at birth (years) males
Life expectancy at birth (years) females
78.0 (2004)
Healthy life expectancy (HALE) at birth (years) males
83.0 (2004)
Healthy life expectancy (HALE) at birth (years) females
70.9 (2002)
74.3 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
86 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males
6 (2004)
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
50 (2004)
5 (2004) 9.5 (2003)
2,874 (2003)
20,155 (2005)
Per capita GDP in international dollars
31,454 (2004)
Austria Indicator
Value (year)
Life expectancy at birth (years) males Life expectancy at birth (years) females
76.0 (2004)
Healthy life expectancy (HALE) at birth (years) males Healthy life expectancy (HALE) at birth (years) females
82.0 (2004)
69.3 (2002)
73.5 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
114 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
Per capita GDP in international dollars
55 (2004)
5 (2004)
5 (2004) 7.5 (2003) 2,306 (2003) 8,189 (2005)
31,648 (2004)
Appendix
1847
Azerbaijan Indicator
Value (year)
Life expectancy at birth (years) males
Life expectancy at birth (years) females
63.0 (2004)
Healthy life expectancy (HALE) at birth (years) males
68.0 (2004)
Healthy life expectancy (HALE) at birth (years) females
55.8 (2002)
58.7 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
205 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males
94 (2004)
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
113 (2004)
85 (2004) 3.6 (2003)
140 (2003)
8,411 (2005)
Per capita GDP in international dollars
4,337 (2004)
Bahamas Indicator
Value (year)
Life expectancy at birth (years) males Life expectancy at birth (years) females
70.0 (2004)
Healthy life expectancy (HALE) at birth (years) males Healthy life expectancy (HALE) at birth (years) females
76.0 (2004)
61.0 (2002)
66.0 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
256 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
Per capita GDP in international dollars
145 (2004)
14 (2004)
12 (2004) 6.4 (2003) 1,220 (2003) 323 (2005)
19,930 (2004)
1848 Appendix
Bahrain Indicator
Value (year)
Life expectancy at birth (years) males
Life expectancy at birth (years) females
73.0 (2004)
Healthy life expectancy (HALE) at birth (years) males
75.0 (2004)
Healthy life expectancy (HALE) at birth (years) females
64.2 (2002)
64.4 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
112 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males
11 (2004)
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
82 (2004)
11 (2004) 4.1 (2003)
813 (2003)
727 (2005)
Per capita GDP in international dollars
21,441 (2004)
Bangladesh Indicator
Value (year)
Life expectancy at birth (years) males Life expectancy at birth (years) females
62.0 (2004)
Healthy life expectancy (HALE) at birth (years) males Healthy life expectancy (HALE) at birth (years) females
63.0 (2004)
55.3 (2002)
53.3 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
251 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
Per capita GDP in international dollars
258 (2004)
81 (2004)
73 (2004) 3.4 (2003) 68 (2003) 141,822 (2005)
2,098 (2004)
Appendix
1849
Barbados Indicator
Value (year)
Life expectancy at birth (years) males
Life expectancy at birth (years) females
71.0 (2004)
Healthy life expectancy (HALE) at birth (years) males
78.0 (2004)
Healthy life expectancy (HALE) at birth (years) females
62.9 (2002)
68.2 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
191 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males
12 (2004)
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
105 (2004)
13 (2004) 6.9 (2003)
1,050 (2003)
270 (2005)
Per capita GDP in international dollars
16,240 (2004)
Belarus Indicator
Value (year)
Life expectancy at birth (years) males Life expectancy at birth (years) females
63.0 (2004)
Healthy life expectancy (HALE) at birth (years) males Healthy life expectancy (HALE) at birth (years) females
74.0 (2004)
56.6 (2002)
64.9 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
377 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
Per capita GDP in international dollars
135 (2004)
11 (2004)
9 (2004) 6.4 (2003) 570 (2003) 9,755 (2005)
11,807 (2004)
1850 Appendix
Belgium Indicator
Value (year)
Life expectancy at birth (years) males
Life expectancy at birth (years) females
75.0 (2004)
Healthy life expectancy (HALE) at birth (years) males
81.0 (2004)
Healthy life expectancy (HALE) at birth (years) females
68.9 (2002)
73.3 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
122 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males
5 (2004)
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
65 (2004)
4 (2004) 9.4 (2003)
2,828 (2003)
10,419 (2005)
Per capita GDP in international dollars
31,481 (2004)
Belize Indicator
Value (year)
Life expectancy at birth (years) males Life expectancy at birth (years) females
65.0 (2004)
Healthy life expectancy (HALE) at birth (years) males Healthy life expectancy (HALE) at birth (years) females
72.0 (2004)
58.4 (2002)
62.2 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
243 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
Per capita GDP in international dollars
135 (2004)
44 (2004)
33 (2004) 4.5 (2003) 309 (2003) 270 (2005)
7,151 (2004)
Appendix
1851
Benin Indicator
Value (year)
Life expectancy at birth (years) males
Life expectancy at birth (years) females
52.0 (2004)
Healthy life expectancy (HALE) at birth (years) males
53.0 (2004)
Healthy life expectancy (HALE) at birth (years) females
43.4 (2002)
44.5 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
388 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males
152 (2004)
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
350 (2004)
153 (2004) 4.4 (2003)
36 (2003)
8,439 (2005)
Per capita GDP in international dollars
836 (2004)
Bhutan Indicator
Value (year)
Life expectancy at birth (years) males Life expectancy at birth (years) females
62.0 (2004)
Healthy life expectancy (HALE) at birth (years) males Healthy life expectancy (HALE) at birth (years) females
65.0 (2004)
52.9 (2002)
52.9 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
255 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
Per capita GDP in international dollars
196 (2004)
80 (2004)
80 (2004) 3.1 (2003) 59 (2003) 2,163 (2005)
2,035 (2004)
1852 Appendix
Bolivia Indicator
Value (year)
Life expectancy at birth (years) males
Life expectancy at birth (years) females
63.0 (2004)
Healthy life expectancy (HALE) at birth (years) males
66.0 (2004)
Healthy life expectancy (HALE) at birth (years) females
53.6 (2002)
55.2 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
248 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males
70 (2004)
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
184 (2004)
68 (2004) 6.7 (2003)
176 (2003)
9,182 (2005)
Per capita GDP in international dollars
2,762 (2004)
Bosnia and Herzegovina Indicator
Value (year)
Life expectancy at birth (years) males Life expectancy at birth (years) females
70.0 (2004)
Healthy life expectancy (HALE) at birth (years) males Healthy life expectancy (HALE) at birth (years) females
77.0 (2004)
62.3 (2002)
66.4 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
188 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
Per capita GDP in international dollars
88 (2004)
17 (2004)
14 (2004) 9.5 (2003) 327 (2003) 3,907 (2005)
3,845 (2004)
Appendix
1853
Botswana Indicator
Value (year)
Life expectancy at birth (years) males
Life expectancy at birth (years) females
40.0 (2004)
Healthy life expectancy (HALE) at birth (years) males
40.0 (2004)
Healthy life expectancy (HALE) at birth (years) females
36.0 (2002)
35.4 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
786 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males
123 (2004)
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
770 (2004)
109 (2004) 5.6 (2003)
375 (2003)
1,765 (2005)
Per capita GDP in international dollars
7,344 (2004)
Brazil Indicator
Value (year)
Life expectancy at birth (years) males Life expectancy at birth (years) females
67.0 (2004)
Healthy life expectancy (HALE) at birth (years) males Healthy life expectancy (HALE) at birth (years) females
74.0 (2004)
57.2 (2002)
62.4 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
237 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
Per capita GDP in international dollars
127 (2004)
38 (2004)
31 (2004) 7.6 (2003) 597 (2003) 186,405 (2005)
8,140 (2004)
1854 Appendix
Brunei Darussalam Indicator
Value (year)
Life expectancy at birth (years) males
Life expectancy at birth (years) females
76.0 (2004)
Healthy life expectancy (HALE) at birth (years) males
78.0 (2004)
Healthy life expectancy (HALE) at birth (years) females
65.1 (2002)
65.5 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
107 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males
10 (2004)
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
81 (2004)
8 (2004) 3.5 (2003)
681 (2003)
374 (2005)
Per capita GDP in international dollars
19,767 (2004)
Bulgaria Indicator
Value (year)
Life expectancy at birth (years) males Life expectancy at birth (years) females
69.0 (2004)
Healthy life expectancy (HALE) at birth (years) males Healthy life expectancy (HALE) at birth (years) females
76.0 (2004)
62.6 (2002)
67.1 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
217 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
Per capita GDP in international dollars
92 (2004)
17 (2004)
13 (2004) 7.5 (2003) 573 (2003) 7,726 (2005)
8,269 (2004)
Appendix
1855
Burkina Faso Indicator
Value (year)
Life expectancy at birth (years) males
Life expectancy at birth (years) females
47.0 (2004)
Healthy life expectancy (HALE) at birth (years) males
48.0 (2004)
Healthy life expectancy (HALE) at birth (years) females
34.9 (2002)
36.3 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
472 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males
193 (2004)
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
410 (2004)
191 (2004) 5.6 (2003)
68 (2003)
13,228 (2005)
Per capita GDP in international dollars
1,263 (2004)
Burundi Indicator
Value (year)
Life expectancy at birth (years) males Life expectancy at birth (years) females
42.0 (2004)
Healthy life expectancy (HALE) at birth (years) males Healthy life expectancy (HALE) at birth (years) females
47.0 (2004)
33.4 (2002)
36.8 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
593 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
Per capita GDP in international dollars
457 (2004)
196 (2004)
184 (2004) 3.1 (2003) 15 (2003) 7,548 (2005)
507 (2004)
1856 Appendix
Cambodia Indicator
Value (year)
Life expectancy at birth (years) males
Life expectancy at birth (years) females
51.0 (2004)
Healthy life expectancy (HALE) at birth (years) males
58.0 (2004)
Healthy life expectancy (HALE) at birth (years) females
45.6 (2002)
49.5 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
430 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males
154 (2004)
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
276 (2004)
127 (2004) 10.9 (2003)
188 (2003)
14,071 (2005)
Per capita GDP in international dollars
1,839 (2004)
Cameroon Indicator
Value (year)
Life expectancy at birth (years) males Life expectancy at birth (years) females
50.0 (2004)
Healthy life expectancy (HALE) at birth (years) males Healthy life expectancy (HALE) at birth (years) females
51.0 (2004)
41.1 (2002)
41.8 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
444 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
Per capita GDP in international dollars
432 (2004)
156 (2004)
143 (2004) 4.2 (2003) 64 (2003) 16,322 (2005)
1,606 (2004)
Appendix
1857
Canada Indicator
Value (year)
Life expectancy at birth (years) males
Life expectancy at birth (years) females
78.0 (2004)
Healthy life expectancy (HALE) at birth (years) males
83.0 (2004)
Healthy life expectancy (HALE) at birth (years) females
70.1 (2002)
74.0 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
91 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males
6 (2004)
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
57 (2004)
5 (2004) 9.9 (2003)
2,989 (2003)
32,268 (2005)
Per capita GDP in international dollars
31,389 (2004)
Cape Verde Indicator
Value (year)
Life expectancy at birth (years) males Life expectancy at birth (years) females
67.0 (2004)
Healthy life expectancy (HALE) at birth (years) males Healthy life expectancy (HALE) at birth (years) females
71.0 (2004)
58.8 (2002)
62.9 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
209 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
Per capita GDP in international dollars
139 (2004)
38 (2004)
35 (2004) 4.6 (2003) 185 (2003) 507 (2005)
4,244 (2004)
1858 Appendix
Central African Republic Indicator
Value (year)
Life expectancy at birth (years) males
Life expectancy at birth (years) females
40.0 (2004)
Healthy life expectancy (HALE) at birth (years) males
41.0 (2004)
Healthy life expectancy (HALE) at birth (years) females
37.0 (2002)
37.7 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
667 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males
201 (2004)
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
624 (2004)
185 (2004) 4.0 (2003)
47 (2003)
4,038 (2005)
Per capita GDP in international dollars
1,182 (2004)
Chad Indicator
Value (year)
Life expectancy at birth (years) males Life expectancy at birth (years) females
45.0 (2004)
Healthy life expectancy (HALE) at birth (years) males Healthy life expectancy (HALE) at birth (years) females
48.0 (2004)
39.7 (2002)
41.7 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
497 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
Per capita GDP in international dollars
422 (2004)
212 (2004)
188 (2004) 6.5 (2003) 51 (2003) 9,749 (2005)
1,199 (2004)
Appendix
1859
Chile Indicator
Value (year)
Life expectancy at birth (years) males
Life expectancy at birth (years) females
74.0 (2004)
Healthy life expectancy (HALE) at birth (years) males
81.0 (2004)
Healthy life expectancy (HALE) at birth (years) females
64.9 (2002)
69.7 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
133 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males
10 (2004)
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
66 (2004)
9 (2004) 6.1 (2003)
707 (2003)
16,295 (2005)
Per capita GDP in international dollars
12,505 (2004)
China Indicator
Value (year)
Life expectancy at birth (years) males Life expectancy at birth (years) females
70.0 (2004)
Healthy life expectancy (HALE) at birth (years) males Healthy life expectancy (HALE) at birth (years) females
74.0 (2004)
63.1 (2002)
65.2 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
158 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
Per capita GDP in international dollars
99 (2004)
27 (2004)
36 (2004) 5.6 (2003) 278 (2003) 1,315,844 (2005)
5,581 (2004)
1860 Appendix
Colombia Indicator
Value (year)
Life expectancy at birth (years) males
Life expectancy at birth (years) females
68.0 (2004)
Healthy life expectancy (HALE) at birth (years) males
77.0 (2004)
Healthy life expectancy (HALE) at birth (years) females
57.8 (2002)
66.3 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
226 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males
24 (2004)
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
93 (2004)
17 (2004) 7.6 (2003)
522 (2003)
45,600 (2005)
Per capita GDP in international dollars
7,319 (2004)
Comoros Indicator
Value (year)
Life expectancy at birth (years) males Life expectancy at birth (years) females
62.0 (2004)
Healthy life expectancy (HALE) at birth (years) males Healthy life expectancy (HALE) at birth (years) females
67.0 (2004)
53.9 (2002)
55.3 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
254 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
Per capita GDP in international dollars
182 (2004)
76 (2004)
64 (2004) 2.7 (2003) 25 (2003) 798 (2005)
985 (2004)
Appendix
1861
Congo Indicator
Value (year)
Life expectancy at birth (years) males
Life expectancy at birth (years) females
53.0 (2004)
Healthy life expectancy (HALE) at birth (years) males
55.0 (2004)
Healthy life expectancy (HALE) at birth (years) females
45.3 (2002)
47.3 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
442 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males
113 (2004)
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
390 (2004)
103 (2004) 2.0 (2003)
23 (2003)
3,999 (2005)
Per capita GDP in international dollars
1,223 (2004)
Cook Islands Indicator
Value (year)
Life expectancy at birth (years) males Life expectancy at birth (years) females
70.0 (2004)
Healthy life expectancy (HALE) at birth (years) males Healthy life expectancy (HALE) at birth (years) females
75.0 (2004)
60.6 (2002)
62.7 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
158 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
Per capita GDP in international dollars
104 (2004)
24 (2004)
17 (2004) 3.8 (2003) 425 (2003) 18 (2005)
11,788 (2004)
1862 Appendix
Costa Rica Indicator
Value (year)
Life expectancy at birth (years) males
Life expectancy at birth (years) females
75.0 (2004)
Healthy life expectancy (HALE) at birth (years) males
80.0 (2004)
Healthy life expectancy (HALE) at birth (years) females
65.2 (2002)
69.3 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
124 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males
14 (2004)
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
71 (2004)
11 (2004) 7.3 (2003)
616 (2003)
4,327 (2005)
Per capita GDP in international dollars
8,949 (2004)
Côte d’Ivoire Indicator
Value (year)
Life expectancy at birth (years) males Life expectancy at birth (years) females
41.0 (2004)
Healthy life expectancy (HALE) at birth (years) males Healthy life expectancy (HALE) at birth (years) females
47.0 (2004)
37.6 (2002)
41.3 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
585 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
Per capita GDP in international dollars
500 (2004)
225 (2004)
162 (2004) 3.6 (2003) 57 (2003) 18,154 (2005)
1,602 (2004)
Appendix
1863
Croatia Indicator
Value (year)
Life expectancy at birth (years) males
Life expectancy at birth (years) females
72.0 (2004)
Healthy life expectancy (HALE) at birth (years) males
79.0 (2004)
Healthy life expectancy (HALE) at birth (years) females
63.8 (2002)
69.3 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
160 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males
8 (2004)
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
66 (2004)
7 (2004) 7.8 (2003)
838 (2003)
4,551 (2005)
Per capita GDP in international dollars
11,406 (2004)
Cuba Indicator
Value (year)
Life expectancy at birth (years) males Life expectancy at birth (years) females
75.0 (2004)
Healthy life expectancy (HALE) at birth (years) males Healthy life expectancy (HALE) at birth (years) females
80.0 (2004)
67.1 (2002)
69.5 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
131 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
Per capita GDP in international dollars
85 (2004)
8 (2004)
7 (2004) 7.3 (2003) 251 (2003) 11,269 (2005)
3,649 (2004)
1864 Appendix
Cyprus Indicator
Value (year)
Life expectancy at birth (years) males
Life expectancy at birth (years) females
77.0 (2004)
Healthy life expectancy (HALE) at birth (years) males
82.0 (2004)
Healthy life expectancy (HALE) at birth (years) females
66.7 (2002)
68.5 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
94 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males
5 (2004)
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
47 (2004)
5 (2004) 6.4 (2003)
1,143 (2003)
835 (2005)
Per capita GDP in international dollars
15,602 (2004)
Czech Republic Indicator
Value (year)
Life expectancy at birth (years) males Life expectancy at birth (years) females
73.0 (2004)
Healthy life expectancy (HALE) at birth (years) males Healthy life expectancy (HALE) at birth (years) females
79.0 (2004)
65.9 (2002)
70.9 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
161 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
Per capita GDP in international dollars
69 (2004)
5 (2004)
4 (2004) 7.5 (2003) 1,302 (2003) 10,220 (2005)
18,598 (2004)
Appendix
1865
Democratic People’s Republic of Korea Indicator
Value (year)
Life expectancy at birth (years) males
Life expectancy at birth (years) females
65.0 (2004)
Healthy life expectancy (HALE) at birth (years) males
68.0 (2004)
Healthy life expectancy (HALE) at birth (years) females
58.0 (2002)
59.7 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
231 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males
56 (2004)
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
168 (2004)
54 (2004) 5.8 (2003)
74 (2003)
22,488 (2005)
Per capita GDP in international dollars
1,339 (2004)
Democratic Republic of the Congo Indicator
Value (year)
Life expectancy at birth (years) males Life expectancy at birth (years) females
42.0 (2004)
Healthy life expectancy (HALE) at birth (years) males Healthy life expectancy (HALE) at birth (years) females
47.0 (2004)
35.0 (2002)
39.1 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
576 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
Per capita GDP in international dollars
446 (2004)
217 (2004)
192 (2004) 4.0 (2003) 14 (2003) 57,549 (2005)
382 (2004)
1866 Appendix
Denmark Indicator
Value (year)
Life expectancy at birth (years) males
Life expectancy at birth (years) females
75.0 (2004)
Healthy life expectancy (HALE) at birth (years) males
80.0 (2004)
Healthy life expectancy (HALE) at birth (years) females
68.6 (2002)
71.1 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
117 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males
5 (2004)
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
72 (2004)
5 (2004) 9.0 (2003)
2,762 (2003)
5,431 (2005)
Per capita GDP in international dollars
31,664 (2004)
Djibouti Indicator
Value (year)
Life expectancy at birth (years) males Life expectancy at birth (years) females
54.0 (2004)
Healthy life expectancy (HALE) at birth (years) males Healthy life expectancy (HALE) at birth (years) females
57.0 (2004)
42.5 (2002)
43.2 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
373 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
Per capita GDP in international dollars
312 (2004)
131 (2004)
120 (2004) 5.7 (2003) 72 (2003) 793 (2005)
1,323 (2004)
Appendix
1867
Dominica Indicator
Value (year)
Life expectancy at birth (years) males
Life expectancy at birth (years) females
72.0 (2004)
Healthy life expectancy (HALE) at birth (years) males
76.0 (2004)
Healthy life expectancy (HALE) at birth (years) females
61.9 (2002)
65.6 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
204 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males
13 (2004)
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
122 (2004)
15 (2004) 6.3 (2003)
320 (2003)
79 (2005)
Per capita GDP in international dollars
5,241 (2004)
Dominican Republic Indicator
Value (year)
Life expectancy at birth (years) males Life expectancy at birth (years) females
64.0 (2004)
Healthy life expectancy (HALE) at birth (years) males Healthy life expectancy (HALE) at birth (years) females
70.0 (2004)
57.2 (2002)
61.9 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
280 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
Per capita GDP in international dollars
169 (2004)
34 (2004)
30 (2004) 7.0 (2003) 335 (2003) 8,895 (2005)
4,986 (2004)
1868 Appendix
Ecuador Indicator
Value (year)
Life expectancy at birth (years) males
Life expectancy at birth (years) females
70.0 (2004)
Healthy life expectancy (HALE) at birth (years) males
75.0 (2004)
Healthy life expectancy (HALE) at birth (years) females
59.8 (2002)
64.1 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
210 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males
29 (2004)
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
128 (2004)
24 (2004) 5.1 (2003)
220 (2003)
13,228 (2005)
Per capita GDP in international dollars
4,620 (2004)
Egypt Indicator
Value (year)
Life expectancy at birth (years) males Life expectancy at birth (years) females
66.0 (2004)
Healthy life expectancy (HALE) at birth (years) males Healthy life expectancy (HALE) at birth (years) females
70.0 (2004)
57.8 (2002)
60.2 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
239 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
Per capita GDP in international dollars
158 (2004)
36 (2004)
36 (2004) 5.8 (2003) 235 (2003) 74,033 (2005)
4,274 (2004)
Appendix
1869
El Salvador Indicator
Value (year)
Life expectancy at birth (years) males
Life expectancy at birth (years) females
68.0 (2004)
Healthy life expectancy (HALE) at birth (years) males
74.0 (2004)
Healthy life expectancy (HALE) at birth (years) females
57.2 (2002)
62.3 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
244 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males
30 (2004)
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
138 (2004)
26 (2004) 8.1 (2003)
378 (2003)
6,881 (2005)
Per capita GDP in international dollars
4,793 (2004)
Equatorial Guinea Indicator
Value (year)
Life expectancy at birth (years) males Life expectancy at birth (years) females
42.0 (2004)
Healthy life expectancy (HALE) at birth (years) males Healthy life expectancy (HALE) at birth (years) females
44.0 (2004)
44.7 (2002)
46.3 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
577 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
Per capita GDP in international dollars
522 (2004)
213 (2004)
195 (2004) 1.5 (2003) 179 (2003) 504 (2005)
15,707 (2004)
1870 Appendix
Eritrea Indicator
Value (year)
Life expectancy at birth (years) males
Life expectancy at birth (years) females
58.0 (2004)
Healthy life expectancy (HALE) at birth (years) males
62.0 (2004)
Healthy life expectancy (HALE) at birth (years) females
49.3 (2002)
50.8 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
345 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males
89 (2004)
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
281 (2004)
75 (2004) 4.4 (2003)
50 (2003)
4,401 (2005)
Per capita GDP in international dollars
1,132 (2004)
Estonia Indicator
Value (year)
Life expectancy at birth (years) males Life expectancy at birth (years) females
66.0 (2004)
Healthy life expectancy (HALE) at birth (years) males Healthy life expectancy (HALE) at birth (years) females
78.0 (2004)
59.2 (2002)
69.0 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
301 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
Per capita GDP in international dollars
108 (2004)
10 (2004)
6 (2004) 5.3 (2003) 682 (2003) 1,330 (2005)
14,102 (2004)
Appendix
1871
Ethiopia Indicator
Value (year)
Life expectancy at birth (years) males
Life expectancy at birth (years) females
49.0 (2004)
Healthy life expectancy (HALE) at birth (years) males
51.0 (2004)
Healthy life expectancy (HALE) at birth (years) females
40.7 (2002)
41.7 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
451 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males
175 (2004)
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
389 (2004)
158 (2004) 5.9 (2003)
20 (2003)
77,431 (2005)
Per capita GDP in international dollars
381 (2004)
Fiji Indicator
Value (year)
Life expectancy at birth (years) males Life expectancy at birth (years) females
66.0 (2004)
Healthy life expectancy (HALE) at birth (years) males Healthy life expectancy (HALE) at birth (years) females
71.0 (2004)
56.9 (2002)
60.6 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
270 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
Per capita GDP in international dollars
169 (2004)
21 (2004)
19 (2004) 3.7 (2003) 220 (2003) 848 (2005)
6,240 (2004)
1872 Appendix
Finland Indicator
Value (year)
Life expectancy at birth (years) males
Life expectancy at birth (years) females
75.0 (2004)
Healthy life expectancy (HALE) at birth (years) males
82.0 (2004)
Healthy life expectancy (HALE) at birth (years) females
68.7 (2002)
73.5 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
137 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males
5 (2004)
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
62 (2004)
3 (2004) 7.4 (2003)
2,108 (2003)
5,249 (2005)
Per capita GDP in international dollars
30,415 (2004)
France Indicator
Value (year)
Life expectancy at birth (years) males Life expectancy at birth (years) females
76.0 (2004)
Healthy life expectancy (HALE) at birth (years) males Healthy life expectancy (HALE) at birth (years) females
83.0 (2004)
69.3 (2002)
74.7 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
132 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
Per capita GDP in international dollars
60 (2004)
5 (2004)
4 (2004) 10.1 (2003) 2,902 (2003) 60,496 (2005)
30,093 (2004)
Appendix
1873
Gabon Indicator
Value (year)
Life expectancy at birth (years) males
Life expectancy at birth (years) females
55.0 (2004)
Healthy life expectancy (HALE) at birth (years) males
59.0 (2004)
Healthy life expectancy (HALE) at birth (years) females
50.2 (2002)
52.6 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
411 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males
102 (2004)
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
344 (2004)
80 (2004) 4.4 (2003)
255 (2003)
1,384 (2005)
Per capita GDP in international dollars
5,942 (2004)
Gambia Indicator
Value (year)
Life expectancy at birth (years) males Life expectancy at birth (years) females
55.0 (2004)
Healthy life expectancy (HALE) at birth (years) males Healthy life expectancy (HALE) at birth (years) females
59.0 (2004)
48.5 (2002)
50.5 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
344 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
Per capita GDP in international dollars
263 (2004)
129 (2004)
115 (2004) 8.1 (2003) 96 (2003) 1,517 (2005)
1,288 (2004)
1874 Appendix
Georgia Indicator
Value (year)
Life expectancy at birth (years) males
Life expectancy at birth (years) females
70.0 (2004)
Healthy life expectancy (HALE) at birth (years) males
77.0 (2004)
Healthy life expectancy (HALE) at birth (years) females
62.2 (2002)
66.6 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
161 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males
51 (2004)
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
60 (2004)
38 (2004) 4.0 (2003)
174 (2003)
4,474 (2005)
Per capita GDP in international dollars
4,829 (2004)
Germany Indicator
Value (year)
Life expectancy at birth (years) males Life expectancy at birth (years) females
76.0 (2004)
Healthy life expectancy (HALE) at birth (years) males Healthy life expectancy (HALE) at birth (years) females
82.0 (2004)
69.6 (2002)
74.0 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
112 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
Per capita GDP in international dollars
58 (2004)
5 (2004)
5 (2004) 11.1 (2003) 3,001 (2003) 82,689 (2005)
28,075 (2004)
Appendix
1875
Ghana Indicator
Value (year)
Life expectancy at birth (years) males
Life expectancy at birth (years) females
56.0 (2004)
Healthy life expectancy (HALE) at birth (years) males
58.0 (2004)
Healthy life expectancy (HALE) at birth (years) females
49.2 (2002)
50.3 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
349 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males
113 (2004)
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
319 (2004)
111 (2004) 4.5 (2003)
98 (2003)
22,113 (2005)
Per capita GDP in international dollars
2,250 (2004)
Greece Indicator
Value (year)
Life expectancy at birth (years) males Life expectancy at birth (years) females
77.0 (2004)
Healthy life expectancy (HALE) at birth (years) males Healthy life expectancy (HALE) at birth (years) females
82.0 (2004)
69.1 (2002)
72.9 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
110 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
Per capita GDP in international dollars
46 (2004)
6 (2004)
4 (2004) 9.9 (2003) 1,997 (2003) 11,120 (2005)
21,437 (2004)
1876 Appendix
Grenada Indicator
Value (year)
Life expectancy at birth (years) males
Life expectancy at birth (years) females
66.0 (2004)
Healthy life expectancy (HALE) at birth (years) males
69.0 (2004)
Healthy life expectancy (HALE) at birth (years) females
58.4 (2002)
60.0 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
256 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males
24 (2004)
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
218 (2004)
19 (2004) 6.7 (2003)
473 (2003)
103 (2005)
Per capita GDP in international dollars
7,022 (2004)
Guatemala Indicator
Value (year)
Life expectancy at birth (years) males Life expectancy at birth (years) females
65.0 (2004)
Healthy life expectancy (HALE) at birth (years) males Healthy life expectancy (HALE) at birth (years) females
71.0 (2004)
54.9 (2002)
59.9 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
276 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
Per capita GDP in international dollars
152 (2004)
45 (2004)
45 (2004) 5.4 (2003) 235 (2003) 12,599 (2005)
4,486 (2004)
Appendix
1877
Guinea Indicator
Value (year)
Life expectancy at birth (years) males
Life expectancy at birth (years) females
52.0 (2004)
Healthy life expectancy (HALE) at birth (years) males
55.0 (2004)
Healthy life expectancy (HALE) at birth (years) females
43.9 (2002)
45.6 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
364 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males
160 (2004)
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
319 (2004)
150 (2004) 5.4 (2003)
95 (2003)
9,402 (2005)
Per capita GDP in international dollars
1,809 (2004)
Guinea-Bissau Indicator
Value (year)
Life expectancy at birth (years) males Life expectancy at birth (years) females
45.0 (2004)
Healthy life expectancy (HALE) at birth (years) males Healthy life expectancy (HALE) at birth (years) females
48.0 (2004)
39.6 (2002)
41.5 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
482 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
Per capita GDP in international dollars
413 (2004)
212 (2004)
194 (2004) 5.6 (2003) 45 (2003) 1,586 (2005)
815 (2004)
1878 Appendix
Guyana Indicator
Value (year)
Life expectancy at birth (years) males
Life expectancy at birth (years) females
62.0 (2004)
Healthy life expectancy (HALE) at birth (years) males
64.0 (2004)
Healthy life expectancy (HALE) at birth (years) females
53.1 (2002)
57.2 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
291 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males
64 (2004)
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
258 (2004)
64 (2004) 4.8 (2003)
283 (2003)
751 (2005)
Per capita GDP in international dollars
6,198 (2004)
Haiti Indicator
Value (year)
Life expectancy at birth (years) males Life expectancy at birth (years) females
53.0 (2004)
Healthy life expectancy (HALE) at birth (years) males Healthy life expectancy (HALE) at birth (years) females
56.0 (2004)
43.5 (2002)
44.1 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
417 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
Per capita GDP in international dollars
358 (2004)
122 (2004)
112 (2004) 7.5 (2003) 84 (2003) 8,528 (2005)
1,100 (2004)
Appendix
1879
Honduras Indicator
Value (year)
Life expectancy at birth (years) males
Life expectancy at birth (years) females
65.0 (2004)
Healthy life expectancy (HALE) at birth (years) males
70.0 (2004)
Healthy life expectancy (HALE) at birth (years) females
56.3 (2002)
60.5 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
258 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males
42 (2004)
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
159 (2004)
40 (2004) 7.1 (2003)
184 (2003)
7,205 (2005)
Per capita GDP in international dollars
2,748 (2004)
Hungary Indicator
Value (year)
Life expectancy at birth (years) males Life expectancy at birth (years) females
69.0 (2004)
Healthy life expectancy (HALE) at birth (years) males Healthy life expectancy (HALE) at birth (years) females
77.0 (2004)
61.5 (2002)
68.2 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
249 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
Per capita GDP in international dollars
108 (2004)
9 (2004)
7 (2004) 8.4 (2003) 1,269 (2003) 10,098 (2005)
15,826 (2004)
1880 Appendix
Iceland Indicator
Value (year)
Life expectancy at birth (years) males
Life expectancy at birth (years) females
79.0 (2004)
Healthy life expectancy (HALE) at birth (years) males
83.0 (2004)
Healthy life expectancy (HALE) at birth (years) females
72.1 (2002)
73.6 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
79 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males
3 (2004)
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
52 (2004)
2 (2004) 10.5 (2003)
3,110 (2003)
295 (2005)
Per capita GDP in international dollars
32,590 (2004)
India Indicator
Value (year)
Life expectancy at birth (years) males Life expectancy at birth (years) females
61.0 (2004)
Healthy life expectancy (HALE) at birth (years) males Healthy life expectancy (HALE) at birth (years) females
63.0 (2004)
53.3 (2002)
53.6 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
275 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
Per capita GDP in international dollars
202 (2004)
81 (2004)
89 (2004) 4.8 (2003) 82 (2003) 1,103,371 (2005)
1,830 (2004)
Appendix
1881
Indonesia Indicator
Value (year)
Life expectancy at birth (years) males
Life expectancy at birth (years) females
65.0 (2004)
Healthy life expectancy (HALE) at birth (years) males
68.0 (2004)
Healthy life expectancy (HALE) at birth (years) females
57.4 (2002)
58.9 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
239 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males
41 (2004)
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
200 (2004)
36 (2004) 3.1 (2003)
113 (2003)
222,781 (2005)
Per capita GDP in international dollars
3,840 (2004)
Iran (Islamic Republic of) Indicator
Value (year)
Life expectancy at birth (years) males Life expectancy at birth (years) females
68.0 (2004)
Healthy life expectancy (HALE) at birth (years) males Healthy life expectancy (HALE) at birth (years) females
72.0 (2004)
56.1 (2002)
59.1 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
190 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
Per capita GDP in international dollars
118 (2004)
39 (2004)
36 (2004) 6.5 (2003) 498 (2003) 69,515 (2005)
8,367 (2004)
1882 Appendix
Iraq Indicator
Value (year)
Life expectancy at birth (years) males
Life expectancy at birth (years) females
51.0 (2004)
Healthy life expectancy (HALE) at birth (years) males
61.0 (2004)
Healthy life expectancy (HALE) at birth (years) females
48.8 (2002)
51.5 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
452 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males
130 (2004)
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
201 (2004)
120 (2004) 2.7 (2003)
64 (2003)
28,807 (2005)
Per capita GDP in international dollars
3,554 (2004)
Ireland Indicator
Value (year)
Life expectancy at birth (years) males Life expectancy at birth (years) females
75.0 (2004)
Healthy life expectancy (HALE) at birth (years) males Healthy life expectancy (HALE) at birth (years) females
81.0 (2004)
68.1 (2002)
71.5 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
105 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
Per capita GDP in international dollars
60 (2004)
7 (2004)
5 (2004) 7.3 (2003) 2,496 (2003) 4,148 (2005)
36,371 (2004)
Appendix
1883
Israel Indicator
Value (year)
Life expectancy at birth (years) males
Life expectancy at birth (years) females
78.0 (2004)
Healthy life expectancy (HALE) at birth (years) males
82.0 (2004)
Healthy life expectancy (HALE) at birth (years) females
70.5 (2002)
72.3 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
91 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males
6 (2004)
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
48 (2004)
6 (2004) 8.9 (2003)
1,911 (2003)
6,725 (2005)
Per capita GDP in international dollars
22,731 (2004)
Italy Indicator
Value (year)
Life expectancy at birth (years) males Life expectancy at birth (years) females
78.0 (2004)
Healthy life expectancy (HALE) at birth (years) males Healthy life expectancy (HALE) at birth (years) females
84.0 (2004)
70.7 (2002)
74.7 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
91 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
Per capita GDP in international dollars
47 (2004)
5 (2004)
4 (2004) 8.4 (2003) 2,266 (2003) 58,093 (2005)
27,952 (2004)
1884 Appendix
Jamaica Indicator
Value (year)
Life expectancy at birth (years) males
Life expectancy at birth (years) females
70.0 (2004)
Healthy life expectancy (HALE) at birth (years) males
74.0 (2004)
Healthy life expectancy (HALE) at birth (years) females
64.2 (2002)
65.9 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
188 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males
21 (2004)
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
120 (2004)
19 (2004) 5.3 (2003)
216 (2003)
2,651 (2005)
Per capita GDP in international dollars
4,330 (2004)
Japan Indicator
Value (year)
Life expectancy at birth (years) males Life expectancy at birth (years) females
79.0 (2004)
Healthy life expectancy (HALE) at birth (years) males Healthy life expectancy (HALE) at birth (years) females
86.0 (2004)
72.3 (2002)
77.7 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
92 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
Per capita GDP in international dollars
45 (2004)
4 (2004)
3 (2004) 7.9 (2003) 2,244 (2003) 128,085 (2005)
30,039 (2004)
Appendix
1885
Jordan Indicator
Value (year)
Life expectancy at birth (years) males
Life expectancy at birth (years) females
69.0 (2004)
Healthy life expectancy (HALE) at birth (years) males
73.0 (2004)
Healthy life expectancy (HALE) at birth (years) females
59.7 (2002)
62.3 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
187 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males
28 (2004)
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
119 (2004)
26 (2004) 9.4 (2003)
440 (2003)
5,703 (2005)
Per capita GDP in international dollars
4,947 (2004)
Kazakhstan Indicator
Value (year)
Life expectancy at birth (years) males Life expectancy at birth (years) females
56.0 (2004)
Healthy life expectancy (HALE) at birth (years) males Healthy life expectancy (HALE) at birth (years) females
67.0 (2004)
52.6 (2002)
59.3 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
424 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
Per capita GDP in international dollars
187 (2004)
83 (2004)
62 (2004) 3.5 (2003) 315 (2003) 14,825 (2005)
9,982 (2004)
1886 Appendix
Kenya Indicator
Value (year)
Life expectancy at birth (years) males
Life expectancy at birth (years) females
51.0 (2004)
Healthy life expectancy (HALE) at birth (years) males
50.0 (2004)
Healthy life expectancy (HALE) at birth (years) females
44.1 (2002)
44.8 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
477 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males
129 (2004)
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
502 (2004)
110 (2004) 4.3 (2003)
65 (2003)
34,256 (2005)
Per capita GDP in international dollars
1,586 (2004)
Kiribati Indicator
Value (year)
Life expectancy at birth (years) males Life expectancy at birth (years) females
63.0 (2004)
Healthy life expectancy (HALE) at birth (years) males Healthy life expectancy (HALE) at birth (years) females
67.0 (2004)
52.3 (2002)
55.6 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
297 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
Per capita GDP in international dollars
175 (2004)
66 (2004)
64 (2004) 13.1 (2003) 253 (2003) 99 (2005)
1,973 (2004)
Appendix
1887
Kuwait Indicator
Value (year)
Life expectancy at birth (years) males
Life expectancy at birth (years) females
76.0 (2004)
Healthy life expectancy (HALE) at birth (years) males
78.0 (2004)
Healthy life expectancy (HALE) at birth (years) females
67.2 (2002)
67.1 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
72 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males
12 (2004)
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
54 (2004)
11 (2004) 3.5 (2003)
567 (2003)
2,687 (2005)
Per capita GDP in international dollars
17,451 (2004)
Kyrgyzstan Indicator
Value (year)
Life expectancy at birth (years) males Life expectancy at birth (years) females
59.0 (2004)
Healthy life expectancy (HALE) at birth (years) males Healthy life expectancy (HALE) at birth (years) females
67.0 (2004)
52.2 (2002)
58.4 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
336 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
Per capita GDP in international dollars
162 (2004)
72 (2004)
63 (2004) 5.3 (2003) 161 (2003) 5,264 (2005)
3,287 (2004)
1888 Appendix
Lao People’s Democratic Republic Indicator
Value (year)
Life expectancy at birth (years) males
Life expectancy at birth (years) females
58.0 (2004)
Healthy life expectancy (HALE) at birth (years) males
60.0 (2004)
Healthy life expectancy (HALE) at birth (years) females
47.1 (2002)
47.0 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
331 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males
88 (2004)
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
300 (2004)
78 (2004) 3.2 (2003)
56 (2003)
5,924 (2005)
Per capita GDP in international dollars
1,878 (2004)
Latvia Indicator
Value (year)
Life expectancy at birth (years) males Life expectancy at birth (years) females
66.0 (2004)
Healthy life expectancy (HALE) at birth (years) males Healthy life expectancy (HALE) at birth (years) females
76.0 (2004)
58.0 (2002)
67.5 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
300 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
Per capita GDP in international dollars
115 (2004)
11 (2004)
11 (2004) 6.4 (2003) 678 (2003) 2,307 (2005)
11,802 (2004)
Appendix
1889
Lebanon Indicator
Value (year)
Life expectancy at birth (years) males
Life expectancy at birth (years) females
68.0 (2004)
Healthy life expectancy (HALE) at birth (years) males
72.0 (2004)
Healthy life expectancy (HALE) at birth (years) females
59.2 (2002)
61.6 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
198 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males
35 (2004)
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
136 (2004)
26 (2004) 10.2 (2003)
730 (2003)
3,577 (2005)
Per capita GDP in international dollars
7,336 (2004)
Lesotho Indicator
Value (year)
Life expectancy at birth (years) males Life expectancy at birth (years) females
39.0 (2004)
Healthy life expectancy (HALE) at birth (years) males Healthy life expectancy (HALE) at birth (years) females
44.0 (2004)
29.6 (2002)
33.2 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
845 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
Per capita GDP in international dollars
728 (2004)
87 (2004)
76 (2004) 5.2 (2003) 106 (2003) 1,795 (2005)
2,152 (2004)
1890 Appendix
Liberia Indicator
Value (year)
Life expectancy at birth (years) males
Life expectancy at birth (years) females
39.0 (2004)
Healthy life expectancy (HALE) at birth (years) males
44.0 (2004)
Healthy life expectancy (HALE) at birth (years) females
33.6 (2002)
37.0 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
596 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males
249 (2004)
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
477 (2004)
220 (2004) 4.7 (2003)
17 (2003)
3,283 (2005)
Per capita GDP in international dollars
386 (2004)
Libyan Arab Jamahiriya Indicator
Value (year)
Life expectancy at birth (years) males Life expectancy at birth (years) females
70.0 (2004)
Healthy life expectancy (HALE) at birth (years) males Healthy life expectancy (HALE) at birth (years) females
75.0 (2004)
62.3 (2002)
65.0 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
186 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
Per capita GDP in international dollars
109 (2004)
20 (2004)
19 (2004) 4.1 (2003) 327 (2003) 5,853 (2005)
7,703 (2004)
Appendix
1891
Lithuania Indicator
Value (year)
Life expectancy at birth (years) males
Life expectancy at birth (years) females
66.0 (2004)
Healthy life expectancy (HALE) at birth (years) males
78.0 (2004)
Healthy life expectancy (HALE) at birth (years) females
58.9 (2002)
67.7 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
304 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males
10 (2004)
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
102 (2004)
9 (2004) 6.6 (2003)
754 (2003)
3,431 (2005)
Per capita GDP in international dollars
12,572 (2004)
Luxembourg Indicator
Value (year)
Life expectancy at birth (years) males Life expectancy at birth (years) females
76.0 (2004)
Healthy life expectancy (HALE) at birth (years) males Healthy life expectancy (HALE) at birth (years) females
81.0 (2004)
69.3 (2002)
73.7 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
118 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
Per capita GDP in international dollars
59 (2004)
6 (2004)
5 (2004) 6.8 (2003) 3,680 (2003) 465 (2005)
57,938 (2004)
1892 Appendix
Madagascar Indicator
Value (year)
Life expectancy at birth (years) males
Life expectancy at birth (years) females
55.0 (2004)
Healthy life expectancy (HALE) at birth (years) males
59.0 (2004)
Healthy life expectancy (HALE) at birth (years) females
47.3 (2002)
49.9 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
338 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males
128 (2004)
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
270 (2004)
117 (2004) 2.7 (2003)
24 (2003)
18,606 (2005)
Per capita GDP in international dollars
965 (2004)
Malawi Indicator
Value (year)
Life expectancy at birth (years) males Life expectancy at birth (years) females
41.0 (2004)
Healthy life expectancy (HALE) at birth (years) males Healthy life expectancy (HALE) at birth (years) females
41.0 (2004)
35.0 (2002)
34.8 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
663 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
Per capita GDP in international dollars
638 (2004)
179 (2004)
172 (2004) 9.3 (2003) 46 (2003) 12,884 (2005)
519 (2004)
Appendix
1893
Malaysia Indicator
Value (year)
Life expectancy at birth (years) males
Life expectancy at birth (years) females
69.0 (2004)
Healthy life expectancy (HALE) at birth (years) males
74.0 (2004)
Healthy life expectancy (HALE) at birth (years) females
61.6 (2002)
64.8 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
200 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males
14 (2004)
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
109 (2004)
11 (2004) 3.8 (2003)
374 (2003)
25,347 (2005)
Per capita GDP in international dollars
10,613 (2004)
Maldives Indicator
Value (year)
Life expectancy at birth (years) males Life expectancy at birth (years) females
66.0 (2004)
Healthy life expectancy (HALE) at birth (years) males Healthy life expectancy (HALE) at birth (years) females
68.0 (2004)
59.0 (2002)
56.6 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
186 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
Per capita GDP in international dollars
140 (2004)
47 (2004)
44 (2004) 6.2 (2003) 364 (2003) 329 (2005)
6,440 (2004)
1894 Appendix
Mali Indicator
Value (year)
Life expectancy at birth (years) males
Life expectancy at birth (years) females
44.0 (2004)
Healthy life expectancy (HALE) at birth (years) males
47.0 (2004)
Healthy life expectancy (HALE) at birth (years) females
37.5 (2002)
38.3 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
490 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males
230 (2004)
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
414 (2004)
208 (2004) 4.8 (2003)
39 (2003)
13,518 (2005)
Per capita GDP in international dollars
830 (2004)
Malta Indicator
Value (year)
Life expectancy at birth (years) males Life expectancy at birth (years) females
76.0 (2004)
Healthy life expectancy (HALE) at birth (years) males Healthy life expectancy (HALE) at birth (years) females
81.0 (2004)
69.9 (2002)
72.9 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
82 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
Per capita GDP in international dollars
48 (2004)
7 (2004)
5 (2004) 9.3 (2003) 1,436 (2003) 402 (2005)
18,308 (2004)
Appendix
1895
Marshall Islands Indicator
Value (year)
Life expectancy at birth (years) males
Life expectancy at birth (years) females
60.0 (2004)
Healthy life expectancy (HALE) at birth (years) males
64.0 (2004)
Healthy life expectancy (HALE) at birth (years) females
53.9 (2002)
55.7 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
327 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males
66 (2004)
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
275 (2004)
52 (2004) 13.1 (2003)
477 (2003)
62 (2005)
Per capita GDP in international dollars
3,673 (2004)
Mauritania Indicator
Value (year)
Life expectancy at birth (years) males Life expectancy at birth (years) females
55.0 (2004)
Healthy life expectancy (HALE) at birth (years) males Healthy life expectancy (HALE) at birth (years) females
60.0 (2004)
42.8 (2002)
46.3 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
325 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
Per capita GDP in international dollars
246 (2004)
134 (2004)
115 (2004) 4.2 (2003) 59 (2003) 3,069 (2005)
1,531 (2004)
1896 Appendix
Mauritius Indicator
Value (year)
Life expectancy at birth (years) males
Life expectancy at birth (years) females
69.0 (2004)
Healthy life expectancy (HALE) at birth (years) males
75.0 (2004)
Healthy life expectancy (HALE) at birth (years) females
60.3 (2002)
64.6 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
217 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males
17 (2004)
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
112 (2004)
14 (2004) 3.7 (2003)
430 (2003)
1,245 (2005)
Per capita GDP in international dollars
12,306 (2004)
Mexico Indicator
Value (year)
Life expectancy at birth (years) males Life expectancy at birth (years) females
72.0 (2004)
Healthy life expectancy (HALE) at birth (years) males Healthy life expectancy (HALE) at birth (years) females
77.0 (2004)
63.3 (2002)
67.6 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
161 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
Per capita GDP in international dollars
94 (2004)
31 (2004)
25 (2004) 6.2 (2003) 582 (2003) 107,029 (2005)
10,158 (2004)
Appendix
1897
Micronesia (Federated States of) Indicator
Value (year)
Life expectancy at birth (years) males
Life expectancy at birth (years) females
68.0 (2004)
Healthy life expectancy (HALE) at birth (years) males
71.0 (2004)
Healthy life expectancy (HALE) at birth (years) females
57.0 (2002)
58.4 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
202 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males
26 (2004)
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
169 (2004)
19 (2004) 6.4 (2003)
270 (2003)
110 (2005)
Per capita GDP in international dollars
4,358 (2004)
Monaco Indicator
Value (year)
Life expectancy at birth (years) males Life expectancy at birth (years) females
78.0 (2004)
Healthy life expectancy (HALE) at birth (years) males Healthy life expectancy (HALE) at birth (years) females
85.0 (2004)
70.7 (2002)
75.2 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
105 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
Per capita GDP in international dollars
45 (2004)
5 (2004)
3 (2004) 9.7 (2003) 4,487 (2003) 35 (2005)
48,371 (2004)
1898 Appendix
Mongolia Indicator
Value (year)
Life expectancy at birth (years) males Life expectancy at birth (years) females
61.0 (2004)
Healthy life expectancy (HALE) at birth (years) males Healthy life expectancy (HALE) at birth (years) females
69.0 (2004)
53.3 (2002)
58.0 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
303 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
Per capita GDP in international dollars
185 (2004)
60 (2004)
45 (2004)
6.7 (2003) 140 (2003) 2,646 (2005)
2,373 (2004)
MONTENEGRO No data yet available for Montenegro. Joint data for the former state union Serbia and Montenegro, from the period before the declaration of independence by Montenegro on June 3, 2006, can be found at http://www.who.int/countries/srb/en/
Appendix
1899
Morocco Indicator
Value (year)
Life expectancy at birth (years) males
Life expectancy at birth (years) females
69.0 (2004)
Healthy life expectancy (HALE) at birth (years) males
73.0 (2004)
Healthy life expectancy (HALE) at birth (years) females
59.5 (2002)
60.9 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
157 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males
47 (2004)
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
102 (2004)
38 (2004) 5.1 (2003)
218 (2003)
31,478 (2005)
Per capita GDP in international dollars
4,557 (2004)
Mozambique Indicator
Value (year)
Life expectancy at birth (years) males Life expectancy at birth (years) females
44.0 (2004)
Healthy life expectancy (HALE) at birth (years) males Healthy life expectancy (HALE) at birth (years) females
46.0 (2004)
36.3 (2002)
37.5 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
627 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
Per capita GDP in international dollars
549 (2004)
154 (2004)
150 (2004) 4.7 (2003) 45 (2003) 19,792 (2005)
1,053 (2004)
1900 Appendix
Myanmar Indicator
Value (year)
Life expectancy at birth (years) males
Life expectancy at birth (years) females
56.0 (2004)
Healthy life expectancy (HALE) at birth (years) males
63.0 (2004)
Healthy life expectancy (HALE) at birth (years) females
49.9 (2002)
53.5 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
334 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males
116 (2004)
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
219 (2004)
93 (2004) 2.8 (2003)
51 (2003)
50,519 (2005)
Per capita GDP in international dollars
1,949 (2004)
Namibia Indicator
Value (year)
Life expectancy at birth (years) males Life expectancy at birth (years) females
52.0 (2004)
Healthy life expectancy (HALE) at birth (years) males Healthy life expectancy (HALE) at birth (years) females
55.0 (2004)
42.9 (2002)
43.8 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
548 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
Per capita GDP in international dollars
489 (2004)
70 (2004)
57 (2004) 6.4 (2003) 359 (2003) 2,031 (2005)
5,921 (2004)
Appendix
1901
Nauru Indicator
Value (year)
Life expectancy at birth (years) males
Life expectancy at birth (years) females
58.0 (2004)
Healthy life expectancy (HALE) at birth (years) males
65.0 (2004)
Healthy life expectancy (HALE) at birth (years) females
52.7 (2002)
57.5 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
448 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males
35 (2004)
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
303 (2004)
24 (2004) 12.3 (2003)
763 (2003)
14 (2005)
Per capita GDP in international dollars
6,401 (2004)
Nepal Indicator
Value (year)
Life expectancy at birth (years) males Life expectancy at birth (years) females
61.0 (2004)
Healthy life expectancy (HALE) at birth (years) males Healthy life expectancy (HALE) at birth (years) females
61.0 (2004)
52.5 (2002)
51.1 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
297 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
Per capita GDP in international dollars
285 (2004)
74 (2004)
79 (2004) 5.3 (2003) 64 (2003) 27,133 (2005)
1,277 (2004)
1902 Appendix
Nepal Indicator
Value (year)
Life expectancy at birth (years) males
Life expectancy at birth (years) females
61.0 (2004)
Healthy life expectancy (HALE) at birth (years) males
61.0 (2004)
Healthy life expectancy (HALE) at birth (years) females
52.5 (2002)
51.1 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
297 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males
74 (2004)
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
285 (2004)
79 (2004) 5.3 (2003)
64 (2003)
27,133 (2005)
Per capita GDP in international dollars
1,277 (2004)
New Zealand Indicator
Value (year)
Life expectancy at birth (years) males Life expectancy at birth (years) females
77.0 (2004)
Healthy life expectancy (HALE) at birth (years) males Healthy life expectancy (HALE) at birth (years) females
82.0 (2004)
69.5 (2002)
72.2 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
95 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
Per capita GDP in international dollars
62 (2004)
7 (2004)
6 (2004) 8.1 (2003) 1,893 (2003) 4,028 (2005)
24,643 (2004)
Appendix
1903
Nicaragua Indicator
Value (year)
Life expectancy at birth (years) males
Life expectancy at birth (years) females
67.0 (2004)
Healthy life expectancy (HALE) at birth (years) males
71.0 (2004)
Healthy life expectancy (HALE) at birth (years) females
59.7 (2002)
63.1 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
214 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males
41 (2004)
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
151 (2004)
35 (2004) 7.7 (2003)
208 (2003)
5,487 (2005)
Per capita GDP in international dollars
2,832 (2004)
Niger Indicator
Value (year)
Life expectancy at birth (years) males Life expectancy at birth (years) females
42.0 (2004)
Healthy life expectancy (HALE) at birth (years) males Healthy life expectancy (HALE) at birth (years) females
41.0 (2004)
35.8 (2002)
35.2 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
506 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
Per capita GDP in international dollars
478 (2004)
256 (2004)
262 (2004) 4.7 (2003) 30 (2003) 13,957 (2005)
650 (2004)
1904 Appendix
Nigeria Indicator
Value (year)
Life expectancy at birth (years) males
Life expectancy at birth (years) females
45.0 (2004)
Healthy life expectancy (HALE) at birth (years) males
46.0 (2004)
Healthy life expectancy (HALE) at birth (years) females
41.3 (2002)
41.8 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
513 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males
198 (2004)
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
478 (2004)
195 (2004) 5.0 (2003)
51 (2003)
131,530 (2005)
Per capita GDP in international dollars
1,085 (2004)
Niue Indicator
Value (year)
Life expectancy at birth (years) males Life expectancy at birth (years) females
68.0 (2004)
Healthy life expectancy (HALE) at birth (years) males Healthy life expectancy (HALE) at birth (years) females
74.0 (2004)
58.9 (2002)
62.0 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
178 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
Per capita GDP in international dollars
138 (2004)
50 (2004)
20 (2004) 9.7 (2003) 153 (2003) 1 (2005)
1,586 (2004)
Appendix
1905
Norway Indicator
Value (year)
Life expectancy at birth (years) males
Life expectancy at birth (years) females
77.0 (2004)
Healthy life expectancy (HALE) at birth (years) males
82.0 (2004)
Healthy life expectancy (HALE) at birth (years) females
70.4 (2002)
73.6 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
93 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males
4 (2004)
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
57 (2004)
4 (2004) 10.3 (2003)
3,809 (2003)
4,620 (2005)
Per capita GDP in international dollars
38,813 (2004)
Oman Indicator
Value (year)
Life expectancy at birth (years) males Life expectancy at birth (years) females
71.0 (2004)
Healthy life expectancy (HALE) at birth (years) males Healthy life expectancy (HALE) at birth (years) females
77.0 (2004)
62.7 (2002)
65.3 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
164 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
Per capita GDP in international dollars
92 (2004)
13 (2004)
12 (2004) 3.2 (2003) 419 (2003) 2,567 (2005)
13,651 (2004)
1906 Appendix
Pakistan Indicator
Value (year)
Life expectancy at birth (years) males
Life expectancy at birth (years) females
62.0 (2004)
Healthy life expectancy (HALE) at birth (years) males
63.0 (2004)
Healthy life expectancy (HALE) at birth (years) females
54.2 (2002)
52.3 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
222 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males
102 (2004)
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
198 (2004)
100 (2004) 2.4 (2003)
48 (2003)
157,935 (2005)
Per capita GDP in international dollars
2,151 (2004)
Palau Indicator
Value (year)
Life expectancy at birth (years) males Life expectancy at birth (years) females
67.0 (2004)
Healthy life expectancy (HALE) at birth (years) males Healthy life expectancy (HALE) at birth (years) females
70.0 (2004)
58.7 (2002)
60.5 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
224 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
Per capita GDP in international dollars
206 (2004)
27 (2004)
28 (2004) 9.7 (2003) 798 (2003) 20 (2005)
8,646 (2004)
Appendix
1907
Panama Indicator
Value (year)
Life expectancy at birth (years) males
Life expectancy at birth (years) females
73.0 (2004)
Healthy life expectancy (HALE) at birth (years) males
78.0 (2004)
Healthy life expectancy (HALE) at birth (years) females
64.3 (2002)
68.0 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
139 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males
26 (2004)
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
82 (2004)
22 (2004) 7.6 (2003)
555 (2003)
3,232 (2005)
Per capita GDP in international dollars
8,103 (2004)
Papua New Guinea Indicator
Value (year)
Life expectancy at birth (years) males Life expectancy at birth (years) females
58.0 (2004)
Healthy life expectancy (HALE) at birth (years) males Healthy life expectancy (HALE) at birth (years) females
61.0 (2004)
51.4 (2002)
52.4 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
322 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
Per capita GDP in international dollars
265 (2004)
98 (2004)
87 (2004) 3.4 (2003) 132 (2003) 5,887 (2005)
4,008 (2004)
1908 Appendix
Paraguay Indicator
Value (year)
Life expectancy at birth (years) males
Life expectancy at birth (years) females
70.0 (2004)
Healthy life expectancy (HALE) at birth (years) males
74.0 (2004)
Healthy life expectancy (HALE) at birth (years) females
59.6 (2002)
64.2 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
176 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males
25 (2004)
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
127 (2004)
23 (2004) 7.3 (2003)
301 (2003)
6,158 (2005)
Per capita GDP in international dollars
4,276 (2004)
Peru Indicator
Value (year)
Life expectancy at birth (years) males Life expectancy at birth (years) females
69.0 (2004)
Healthy life expectancy (HALE) at birth (years) males Healthy life expectancy (HALE) at birth (years) females
73.0 (2004)
59.6 (2002)
62.4 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
184 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
Per capita GDP in international dollars
134 (2004)
31 (2004)
27 (2004) 4.4 (2003) 233 (2003) 27,968 (2005)
5,671 (2004)
Appendix
1909
Philippines Indicator
Value (year)
Life expectancy at birth (years) males
Life expectancy at birth (years) females
65.0 (2004)
Healthy life expectancy (HALE) at birth (years) males
72.0 (2004)
Healthy life expectancy (HALE) at birth (years) females
57.1 (2002)
61.5 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
269 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males
40 (2004)
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
149 (2004)
28 (2004) 3.2 (2003)
174 (2003)
83,054 (2005)
Per capita GDP in international dollars
5,856 (2004)
Poland Indicator
Value (year)
Life expectancy at birth (years) males Life expectancy at birth (years) females
71.0 (2004)
Healthy life expectancy (HALE) at birth (years) males Healthy life expectancy (HALE) at birth (years) females
79.0 (2004)
63.1 (2002)
68.5 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
198 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
Per capita GDP in international dollars
79 (2004)
8 (2004)
7 (2004) 6.5 (2003) 745 (2003) 38,530 (2005)
12,647 (2004)
1910 Appendix
Portugal Indicator
Value (year)
Life expectancy at birth (years) males
Life expectancy at birth (years) females
74.0 (2004)
Healthy life expectancy (HALE) at birth (years) males
81.0 (2004)
Healthy life expectancy (HALE) at birth (years) females
66.7 (2002)
71.7 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
144 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males
6 (2004)
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
61 (2004)
5 (2004) 9.6 (2003)
1,791 (2003)
10,495 (2005)
Per capita GDP in international dollars
19,475 (2004)
Qatar Indicator
Value (year)
Life expectancy at birth (years) males Life expectancy at birth (years) females
76.0 (2004)
Healthy life expectancy (HALE) at birth (years) males Healthy life expectancy (HALE) at birth (years) females
75.0 (2004)
66.7 (2002)
63.8 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
75 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
Per capita GDP in international dollars
70 (2004)
12 (2004)
11 (2004) 2.7 (2003) 685 (2003) 813 (2005)
27,284 (2004)
Appendix
1911
Republic of Korea Indicator
Value (year)
Life expectancy at birth (years) males
Life expectancy at birth (years) females
73.0 (2004)
Healthy life expectancy (HALE) at birth (years) males
80.0 (2004)
Healthy life expectancy (HALE) at birth (years) females
64.8 (2002)
70.8 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
151 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males
5 (2004)
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
55 (2004)
7 (2004) 5.6 (2003)
1,074 (2003)
47,817 (2005)
Per capita GDP in international dollars
20,901 (2004)
Republic of Moldova Indicator
Value (year)
Life expectancy at birth (years) males Life expectancy at birth (years) females
64.0 (2004)
Healthy life expectancy (HALE) at birth (years) males Healthy life expectancy (HALE) at birth (years) females
71.0 (2004)
57.2 (2002)
62.4 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
300 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
Per capita GDP in international dollars
150 (2004)
32 (2004)
24 (2004) 7.2 (2003) 177 (2003) 4,206 (2005)
2,709 (2004)
1912 Appendix
Romania Indicator
Value (year)
Life expectancy at birth (years) males
68.0 (2004)
Life expectancy at birth (years) females
Healthy life expectancy (HALE) at birth (years) males
76.0 (2004)
Healthy life expectancy (HALE) at birth (years) females
61.0 (2002)
65.2 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
232 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males
22 (2004)
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
100 (2004)
18 (2004) 6.1 (2003)
540 (2003)
21,711 (2005)
Per capita GDP in international dollars
9,884 (2004)
Russian Federation Indicator
Value (year)
Life expectancy at birth (years) males Life expectancy at birth (years) females
59.0 (2004)
Healthy life expectancy (HALE) at birth (years) males Healthy life expectancy (HALE) at birth (years) females
72.0 (2004)
52.8 (2002)
64.1 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
485 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
Per capita GDP in international dollars
180 (2004)
18 (2004)
14 (2004) 5.6 (2003) 551 (2003) 143,202 (2005)
10,865 (2004)
Appendix
1913
Rwanda Indicator
Value (year)
Life expectancy at birth (years) males
Life expectancy at birth (years) females
44.0 (2004)
Healthy life expectancy (HALE) at birth (years) males
47.0 (2004)
Healthy life expectancy (HALE) at birth (years) females
36.4 (2002)
40.2 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
518 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males
211 (2004)
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
435 (2004)
195 (2004) 3.7 (2003)
32 (2003)
9,038 (2005)
Per capita GDP in international dollars
893 (2004)
Saint Kitts and Nevis Indicator
Value (year)
Life expectancy at birth (years) males Life expectancy at birth (years) females
69.0 (2004)
Healthy life expectancy (HALE) at birth (years) males Healthy life expectancy (HALE) at birth (years) females
72.0 (2004)
59.9 (2002)
63.1 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
197 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
Per capita GDP in international dollars
145 (2004)
21 (2004)
22 (2004) 5.3 (2003) 670 (2003) 43 (2005)
13,633 (2004)
1914 Appendix
Saint Lucia Indicator
Value (year)
Life expectancy at birth (years) males
Life expectancy at birth (years) females
71.0 (2004)
Healthy life expectancy (HALE) at birth (years) males
77.0 (2004)
Healthy life expectancy (HALE) at birth (years) females
61.2 (2002)
64.2 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
209 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males
15 (2004)
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
116 (2004)
13 (2004) 5.0 (2003)
294 (2003)
161 (2005)
Per capita GDP in international dollars
6,084 (2004)
Saint Vincent and the Grenadines Indicator
Value (year)
Life expectancy at birth (years) males Life expectancy at birth (years) females
66.0 (2004)
Healthy life expectancy (HALE) at birth (years) males Healthy life expectancy (HALE) at birth (years) females
73.0 (2004)
59.9 (2002)
62.2 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
301 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
Per capita GDP in international dollars
174 (2004)
26 (2004)
19 (2004) 6.1 (2003) 384 (2003) 119 (2005)
6,855 (2004)
Appendix
1915
Samoa Indicator
Value (year)
Life expectancy at birth (years) males
Life expectancy at birth (years) females
66.0 (2004)
Healthy life expectancy (HALE) at birth (years) males
70.0 (2004)
Healthy life expectancy (HALE) at birth (years) females
59.2 (2002)
60.3 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
235 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males
42 (2004)
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
203 (2004)
17 (2004) 5.4 (2003)
209 (2003)
185 (2005)
Per capita GDP in international dollars
4,151 (2004)
San Marino Indicator
Value (year)
Life expectancy at birth (years) males Life expectancy at birth (years) females
79.0 (2004)
Healthy life expectancy (HALE) at birth (years) males Healthy life expectancy (HALE) at birth (years) females
84.0 (2004)
70.9 (2002)
75.9 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
66 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
Per capita GDP in international dollars
34 (2004)
4 (2004)
3 (2004) 7.5 (2003) 3,133 (2003) 28 (2005)
40,552 (2004)
1916 Appendix
Sao Tome and Principe Indicator
Value (year)
Life expectancy at birth (years) males
Life expectancy at birth (years) females
57.0 (2004)
Healthy life expectancy (HALE) at birth (years) males
60.0 (2004)
Healthy life expectancy (HALE) at birth (years) females
54.2 (2002)
54.7 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
301 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males
122 (2004)
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
236 (2004)
114 (2004) 8.6 (2003)
93 (2003)
157 (2005)
Per capita GDP in international dollars
1,139 (2004)
Saudi Arabia Indicator
Value (year)
Life expectancy at birth (years) males Life expectancy at birth (years) females
68.0 (2004)
Healthy life expectancy (HALE) at birth (years) males Healthy life expectancy (HALE) at birth (years) females
74.0 (2004)
59.8 (2002)
62.9 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
196 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
Per capita GDP in international dollars
120 (2004)
29 (2004)
24 (2004) 4.0 (2003) 578 (2003) 24,573 (2005)
15,307 (2004)
Appendix
1917
Senegal Indicator
Value (year)
Life expectancy at birth (years) males
Life expectancy at birth (years) females
54.0 (2004)
Healthy life expectancy (HALE) at birth (years) males
57.0 (2004)
Healthy life expectancy (HALE) at birth (years) females
47.1 (2002)
48.9 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
358 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males
141 (2004)
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
288 (2004)
132 (2004) 5.1 (2003)
58 (2003)
11,658 (2005)
Per capita GDP in international dollars
1,232 (2004)
The former state union Serbia and Montenegro Indicator
Value (year)
Life expectancy at birth (years) males Life expectancy at birth (years) females
70.0 (2004)
Healthy life expectancy (HALE) at birth (years) males Healthy life expectancy (HALE) at birth (years) females
75.0 (2004)
62.7 (2002)
64.9 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
191 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
Per capita GDP in international dollars
98 (2004)
17 (2004)
13 (2004) 9.6 (2003) 373 (2003) 10,503 (2005)
4,272 (2004)
1918 Appendix
Seychelles Indicator
Value (year)
Life expectancy at birth (years) males
Life expectancy at birth (years) females
67.0 (2004)
Healthy life expectancy (HALE) at birth (years) males
78.0 (2004)
Healthy life expectancy (HALE) at birth (years) females
57.4 (2002)
64.9 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
232 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males
14 (2004)
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
83 (2004)
13 (2004) 5.9 (2003)
599 (2003)
81 (2005)
Per capita GDP in international dollars
10,245 (2004)
Sierra Leone Indicator
Value (year)
Life expectancy at birth (years) males Life expectancy at birth (years) females
37.0 (2004)
Healthy life expectancy (HALE) at birth (years) males Healthy life expectancy (HALE) at birth (years) females
40.0 (2004)
27.2 (2002)
29.9 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
579 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
Per capita GDP in international dollars
497 (2004)
296 (2004)
269 (2004) 3.5 (2003) 34 (2003) 5,525 (2005)
1,039 (2004)
Appendix
1919
Singapore Indicator
Value (year)
Life expectancy at birth (years) males
Life expectancy at birth (years) females
77.0 (2004)
Healthy life expectancy (HALE) at birth (years) males
82.0 (2004)
Healthy life expectancy (HALE) at birth (years) females
68.8 (2002)
71.3 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
92 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males
4 (2004)
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
51 (2004)
3 (2004) 4.5 (2003)
1,156 (2003)
4,326 (2005)
Per capita GDP in international dollars
28,848 (2004)
Slovakia Indicator
Value (year)
Life expectancy at birth (years) males Life expectancy at birth (years) females
70.0 (2004)
Healthy life expectancy (HALE) at birth (years) males Healthy life expectancy (HALE) at birth (years) females
78.0 (2004)
63.0 (2002)
69.4 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
203 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
Per capita GDP in international dollars
76 (2004)
9 (2004)
8 (2004) 5.9 (2003) 777 (2003) 5,401 (2005)
14,310 (2004)
1920 Appendix
Slovenia Indicator
Value (year)
Life expectancy at birth (years) males
Life expectancy at birth (years) females
73.0 (2004)
Healthy life expectancy (HALE) at birth (years) males
81.0 (2004)
Healthy life expectancy (HALE) at birth (years) females
66.6 (2002)
72.3 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
158 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males
5 (2004)
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
67 (2004)
4 (2004) 8.8 (2003)
1,669 (2003)
1,967 (2005)
Per capita GDP in international dollars
20,326 (2004)
Solomon Islands Indicator
Value (year)
Life expectancy at birth (years) males Life expectancy at birth (years) females
66.0 (2004)
Healthy life expectancy (HALE) at birth (years) males Healthy life expectancy (HALE) at birth (years) females
70.0 (2004)
55.4 (2002)
57.1 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
193 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
Per capita GDP in international dollars
143 (2004)
60 (2004)
52 (2004) 4.8 (2003) 87 (2003) 478 (2005)
1,913 (2004)
Appendix
1921
Somalia Indicator
Value (year)
Life expectancy at birth (years) males
Life expectancy at birth (years) females
43.0 (2004)
Healthy life expectancy (HALE) at birth (years) males
45.0 (2004)
Healthy life expectancy (HALE) at birth (years) females
36.1 (2002)
37.5 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
524 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males
222 (2004)
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
428 (2004)
228 (2004) n/a (2003)
n/a (2003)
8,228 (2005)
Per capita GDP in international dollars
n/a (2004)
South Africa Indicator
Value (year)
Life expectancy at birth (years) males Life expectancy at birth (years) females
47.0 (2004)
Healthy life expectancy (HALE) at birth (years) males Healthy life expectancy (HALE) at birth (years) females
49.0 (2004)
43.3 (2002)
45.3 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
667 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
Per capita GDP in international dollars
598 (2004)
72 (2004)
62 (2004) 8.4 (2003) 669 (2003) 47,432 (2005)
8,506 (2004)
1922 Appendix
Spain Indicator
Value (year)
Life expectancy at birth (years) males
Life expectancy at birth (years) females
77.0 (2004)
Healthy life expectancy (HALE) at birth (years) males
83.0 (2004)
Healthy life expectancy (HALE) at birth (years) females
69.9 (2002)
75.3 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
113 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males
5 (2004)
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
45 (2004)
4 (2004) 7.7 (2003)
1,853 (2003)
43,064 (2005)
Per capita GDP in international dollars
24,325 (2004)
Sri Lanka Indicator
Value (year)
Life expectancy at birth (years) males Life expectancy at birth (years) females
68.0 (2004)
Healthy life expectancy (HALE) at birth (years) males Healthy life expectancy (HALE) at birth (years) females
75.0 (2004)
59.2 (2002)
64.0 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
232 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
Per capita GDP in international dollars
119 (2004)
16 (2004)
12 (2004) 3.5 (2003) 121 (2003) 20,743 (2005)
3,800 (2004)
Appendix
1923
Sudan Indicator
Value (year)
Life expectancy at birth (years) males
Life expectancy at birth (years) females
56.0 (2004)
Healthy life expectancy (HALE) at birth (years) males
60.0 (2004)
Healthy life expectancy (HALE) at birth (years) females
47.2 (2002)
49.9 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
390 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males
98 (2004)
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
304 (2004)
84 (2004) 4.3 (2003)
54 (2003)
36,233 (2005)
Per capita GDP in international dollars
1,361 (2004)
Suriname Indicator
Value (year)
Life expectancy at birth (years) males Life expectancy at birth (years) females
65.0 (2004)
Healthy life expectancy (HALE) at birth (years) males Healthy life expectancy (HALE) at birth (years) females
70.0 (2004)
56.7 (2002)
60.8 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
261 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
Per capita GDP in international dollars
159 (2004)
42 (2004)
36 (2004) 7.9 (2003) 309 (2003) 449 (2005)
4,329 (2004)
1924 Appendix
Swaziland Indicator
Value (year)
Life expectancy at birth (years) males
Life expectancy at birth (years) females
36.0 (2004)
Healthy life expectancy (HALE) at birth (years) males
39.0 (2004)
Healthy life expectancy (HALE) at birth (years) females
33.2 (2002)
35.2 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
823 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males
163 (2004)
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
741 (2004)
150 (2004) 5.8 (2003)
324 (2003)
1,032 (2005)
Per capita GDP in international dollars
5,893 (2004)
Sweden Indicator
Value (year)
Life expectancy at birth (years) males Life expectancy at birth (years) females
78.0 (2004)
Healthy life expectancy (HALE) at birth (years) males Healthy life expectancy (HALE) at birth (years) females
83.0 (2004)
71.9 (2002)
74.8 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
82 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
Per capita GDP in international dollars
51 (2004)
4 (2004)
3 (2004) 9.4 (2003) 2,704 (2003) 9,041 (2005)
30,336 (2004)
Appendix
1925
Switzerland Indicator
Value (year)
Life expectancy at birth (years) males
Life expectancy at birth (years) females
78.0 (2004)
Healthy life expectancy (HALE) at birth (years) males
83.0 (2004)
Healthy life expectancy (HALE) at birth (years) females
71.1 (2002)
75.3 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
87 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males
5 (2004)
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
49 (2004)
5 (2004) 11.5 (2003)
3,776 (2003)
7,252 (2005)
Per capita GDP in international dollars
34,087 (2004)
Syrian Arab Republic Indicator
Value (year)
Life expectancy at birth (years) males Life expectancy at birth (years) females
70.0 (2004)
Healthy life expectancy (HALE) at birth (years) males Healthy life expectancy (HALE) at birth (years) females
74.0 (2004)
60.4 (2002)
63.1 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
186 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
Per capita GDP in international dollars
125 (2004)
19 (2004)
14 (2004) 5.1 (2003) 116 (2003) 19,043 (2005)
2,449 (2004)
1926 Appendix
Tajikistan Indicator
Value (year)
Life expectancy at birth (years) males
Life expectancy at birth (years) females
62.0 (2004)
Healthy life expectancy (HALE) at birth (years) males
64.0 (2004)
Healthy life expectancy (HALE) at birth (years) females
53.1 (2002)
56.4 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
166 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males
120 (2004)
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
139 (2004)
115 (2004) 4.4 (2003)
71 (2003)
6,507 (2005)
Per capita GDP in international dollars
1,816 (2004)
Thailand Indicator
Value (year)
Life expectancy at birth (years) males Life expectancy at birth (years) females
67.0 (2004)
Healthy life expectancy (HALE) at birth (years) males Healthy life expectancy (HALE) at birth (years) females
73.0 (2004)
57.7 (2002)
62.4 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
265 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
Per capita GDP in international dollars
154 (2004)
23 (2004)
20 (2004) 3.3 (2003) 260 (2003) 64,233 (2005)
8,373 (2004)
Appendix
1927
The former Yugoslav Republic of Macedonia Indicator
Value (year)
Life expectancy at birth (years) males
Life expectancy at birth (years) females
69.0 (2004)
Healthy life expectancy (HALE) at birth (years) males
76.0 (2004)
Healthy life expectancy (HALE) at birth (years) females
61.9 (2002)
65.0 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
198 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males
16 (2004)
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
84 (2004)
12 (2004) 7.1 (2003)
389 (2003)
2,034 (2005)
Per capita GDP in international dollars
5,892 (2004)
Timor-Leste Indicator
Value (year)
Life expectancy at birth (years) males Life expectancy at birth (years) females
61.0 (2004)
Healthy life expectancy (HALE) at birth (years) males Healthy life expectancy (HALE) at birth (years) females
66.0 (2004)
47.9 (2002)
51.8 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
267 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
Per capita GDP in international dollars
184 (2004)
91 (2004)
69 (2004) 9.6 (2003) 125 (2003) 947 (2005)
1,271 (2004)
1928 Appendix
Togo Indicator
Value (year)
Life expectancy at birth (years) males
Life expectancy at birth (years) females
52.0 (2004)
Healthy life expectancy (HALE) at birth (years) males
56.0 (2004)
Healthy life expectancy (HALE) at birth (years) females
43.5 (2002)
45.7 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
401 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males
151 (2004)
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
327 (2004)
128 (2004) 5.6 (2003)
62 (2003)
6,145 (2005)
Per capita GDP in international dollars
1,123 (2004)
Tonga Indicator
Value (year)
Life expectancy at birth (years) males Life expectancy at birth (years) females
71.0 (2004)
Healthy life expectancy (HALE) at birth (years) males Healthy life expectancy (HALE) at birth (years) females
70.0 (2004)
61.9 (2002)
61.8 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
140 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
Per capita GDP in international dollars
194 (2004)
32 (2004)
17 (2004) 6.5 (2003) 300 (2003) 102 (2005)
4,771 (2004)
Appendix
1929
Trinidad and Tobago Indicator
Value (year)
Life expectancy at birth (years) males
Life expectancy at birth (years) females
67.0 (2004)
Healthy life expectancy (HALE) at birth (years) males
73.0 (2004)
Healthy life expectancy (HALE) at birth (years) females
59.8 (2002)
64.2 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
257 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males
24 (2004)
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
156 (2004)
15 (2004) 3.9 (2003)
532 (2003)
1,305 (2005)
Per capita GDP in international dollars
14,903 (2004)
Tunisia Indicator
Value (year)
Life expectancy at birth (years) males Life expectancy at birth (years) females
70.0 (2004)
Healthy life expectancy (HALE) at birth (years) males Healthy life expectancy (HALE) at birth (years) females
74.0 (2004)
61.3 (2002)
63.6 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
166 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
Per capita GDP in international dollars
110 (2004)
29 (2004)
22 (2004) 5.4 (2003) 409 (2003) 10,102 (2005)
8,162 (2004)
1930 Appendix
Turkey Indicator
Value (year)
Life expectancy at birth (years) males
Life expectancy at birth (years) females
69.0 (2004)
Healthy life expectancy (HALE) at birth (years) males
73.0 (2004)
Healthy life expectancy (HALE) at birth (years) females
61.2 (2002)
62.8 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
180 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males
33 (2004)
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
112 (2004)
31 (2004) 7.6 (2003)
528 (2003)
73,193 (2005)
Per capita GDP in international dollars
7,688 (2004)
Turkmenistan Indicator
Value (year)
Life expectancy at birth (years) males Life expectancy at birth (years) females
56.0 (2004)
Healthy life expectancy (HALE) at birth (years) males Healthy life expectancy (HALE) at birth (years) females
65.0 (2004)
51.6 (2002)
57.2 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
350 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
Per capita GDP in international dollars
166 (2004)
117 (2004)
88 (2004) 3.9 (2003) 221 (2003) 4,833 (2005)
5,947 (2004)
Appendix
1931
Tuvalu Indicator
Value (year)
Life expectancy at birth (years) males
Life expectancy at birth (years) females
61.0 (2004)
Healthy life expectancy (HALE) at birth (years) males
62.0 (2004)
Healthy life expectancy (HALE) at birth (years) females
53.0 (2002)
53.1 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
325 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males
50 (2004)
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
277 (2004)
52 (2004) 6.1 (2003)
74 (2003)
10 (2005)
Per capita GDP in international dollars
1,247 (2004)
Uganda Indicator
Value (year)
Life expectancy at birth (years) males Life expectancy at birth (years) females
48.0 (2004)
Healthy life expectancy (HALE) at birth (years) males Healthy life expectancy (HALE) at birth (years) females
51.0 (2004)
41.7 (2002)
43.7 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
525 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
Per capita GDP in international dollars
446 (2004)
144 (2004)
132 (2004) 7.3 (2003) 75 (2003) 28,816 (2005)
1,088 (2004)
1932 Appendix
Ukraine Indicator
Value (year)
Life expectancy at birth (years) males
Life expectancy at birth (years) females
62.0 (2004)
Healthy life expectancy (HALE) at birth (years) males
73.0 (2004)
Healthy life expectancy (HALE) at birth (years) females
54.9 (2002)
63.6 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
386 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males
21 (2004)
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
144 (2004)
15 (2004) 5.7 (2003)
305 (2003)
46,481 (2005)
Per capita GDP in international dollars
6,216 (2004)
United Arab Emirates Indicator
Value (year)
Life expectancy at birth (years) males Life expectancy at birth (years) females
76.0 (2004)
Healthy life expectancy (HALE) at birth (years) males Healthy life expectancy (HALE) at birth (years) females
79.0 (2004)
63.5 (2002)
64.2 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
89 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
Per capita GDP in international dollars
67 (2004)
8 (2004)
7 (2004) 3.3 (2003) 623 (2003) 4,496 (2005)
18,754 (2004)
Appendix
1933
United Kingdom Indicator
Value (year)
Life expectancy at birth (years) males
Life expectancy at birth (years) females
76.0 (2004)
Healthy life expectancy (HALE) at birth (years) males
81.0 (2004)
Healthy life expectancy (HALE) at birth (years) females
69.1 (2002)
72.1 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
102 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males
6 (2004)
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
63 (2004)
5 (2004) 8.0 (2003)
2,389 (2003)
59,668 (2005)
Per capita GDP in international dollars
31,308 (2004)
United Republic of Tanzania Indicator
Value (year)
Life expectancy at birth (years) males Life expectancy at birth (years) females
47.0 (2004)
Healthy life expectancy (HALE) at birth (years) males Healthy life expectancy (HALE) at birth (years) females
49.0 (2004)
40.0 (2002)
40.7 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
551 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
Per capita GDP in international dollars
524 (2004)
134 (2004)
117 (2004) 4.3 (2003) 29 (2003) 38,329 (2005)
732 (2004)
1934 Appendix
United States of America Indicator
Value (year)
Life expectancy at birth (years) males
Life expectancy at birth (years) females
75.0 (2004)
Healthy life expectancy (HALE) at birth (years) males
80.0 (2004)
Healthy life expectancy (HALE) at birth (years) females
67.2 (2002)
71.3 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
137 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males
8 (2004)
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
81 (2004)
7 (2004) 15.2 (2003)
5,711 (2003)
298,213 (2005)
Per capita GDP in international dollars
39,901 (2004)
Uruguay Indicator
Value (year)
Life expectancy at birth (years) males Life expectancy at birth (years) females
71.0 (2004)
Healthy life expectancy (HALE) at birth (years) males Healthy life expectancy (HALE) at birth (years) females
79.0 (2004)
63.0 (2002)
69.4 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
172 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
Per capita GDP in international dollars
87 (2004)
16 (2004)
12 (2004) 9.8 (2003) 824 (2003) 3,463 (2005)
9,630 (2004)
Appendix
1935
Uzbekistan Indicator
Value (year)
Life expectancy at birth (years) males
Life expectancy at birth (years) females
63.0 (2004)
Healthy life expectancy (HALE) at birth (years) males
69.0 (2004)
Healthy life expectancy (HALE) at birth (years) females
57.9 (2002)
60.9 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
223 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males
80 (2004)
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
141 (2004)
57 (2004) 5.5 (2003)
159 (2003)
26,593 (2005)
Per capita GDP in international dollars
3,125 (2004)
Vanuatu Indicator
Value (year)
Life expectancy at birth (years) males Life expectancy at birth (years) females
67.0 (2004)
Healthy life expectancy (HALE) at birth (years) males Healthy life expectancy (HALE) at birth (years) females
69.0 (2004)
58.5 (2002)
59.4 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
212 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
Per capita GDP in international dollars
170 (2004)
40 (2004)
40 (2004) 3.9 (2003) 110 (2003) 211 (2005)
2,877 (2004)
1936 Appendix
Venezuela (Bolivarian Republic of) Indicator
Value (year)
Life expectancy at birth (years) males
Life expectancy at birth (years) females
72.0 (2004)
Healthy life expectancy (HALE) at birth (years) males
78.0 (2004)
Healthy life expectancy (HALE) at birth (years) females
61.7 (2002)
66.7 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
185 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males
20 (2004)
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
97 (2004)
17 (2004) 4.5 (2003)
231 (2003)
26,749 (2005)
Per capita GDP in international dollars
6,104 (2004)
Viet Nam Indicator
Value (year)
Life expectancy at birth (years) males Life expectancy at birth (years) females
69.0 (2004)
Healthy life expectancy (HALE) at birth (years) males Healthy life expectancy (HALE) at birth (years) females
74.0 (2004)
59.8 (2002)
62.9 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
197 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
Per capita GDP in international dollars
122 (2004)
24 (2004)
22 (2004) 5.4 (2003) 164 (2003) 84,238 (2005)
3,298 (2004)
Appendix
1937
Yemen Indicator
Value (year)
Life expectancy at birth (years) males
Life expectancy at birth (years) females
57.0 (2004)
Healthy life expectancy (HALE) at birth (years) males
61.0 (2004)
Healthy life expectancy (HALE) at birth (years) females
48.0 (2002)
50.7 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
298 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males
118 (2004)
Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
225 (2004)
104 (2004) 5.5 (2003)
89 (2003)
20,975 (2005)
Per capita GDP in international dollars
1,653 (2004)
Zambia Indicator
Value (year)
Life expectancy at birth (years) males Life expectancy at birth (years) females
40.0 (2004)
Healthy life expectancy (HALE) at birth (years) males Healthy life expectancy (HALE) at birth (years) females
40.0 (2004)
34.8 (2002)
35.0 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
683 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
Per capita GDP in international dollars
656 (2004)
190 (2004)
173 (2004) 5.4 (2003) 51 (2003) 11,668 (2005)
1,013 (2004)
1938 Appendix
Zimbabwe Indicator
Value (year)
Life expectancy at birth (years) males Life expectancy at birth (years) females
37.0 (2004)
Healthy life expectancy (HALE) at birth (years) males Healthy life expectancy (HALE) at birth (years) females
34.0 (2004)
33.8 (2002)
33.3 (2002)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) males
857 (2004)
Probability of dying (per 1 000 population) between 15 and 60 years (adult mortality rate) females Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) males Probability of dying (per 1 000 population) under five years of age (under-5 mortality rate) females Total expenditure on health as percentage of gross domestic product Per capita total expenditure on health at international dollar rate Population (in thousands) total
Per capita GDP in international dollars
849 (2004)
136 (2004)
121 (2004) 7.9 (2003) 132 (2003) 13,010 (2005)
1,588 (2004)
Index Note: Page numbers in boldface refer to volume numbers and major topics. Article titles are in boldface. A
Accreditation Council for Continuing Medical
abdominal aortic aneurysms (AAA), 1:136–137
Education (ACCME), 1:92, 94, 116 Accutane, 1:7
abdominal pain, 2:528–529
acetaminophen, 1:197
Abdullah II, 2:962
Achenbach, Thomas, 1:384
Abel, John Jacob, 3:1368
achilles tendon, injuries of, 2:681, 4:1603
Abittan, C. S., 3:1025
acid-fast stain, 1:207
ABO blood type system, 1:60
acid peptic disease, 4:1615–1616
abortion, 1:1–4, 3:1203, 4:1480–1481
acid rain, 1:49–50
abscess, anal/rectal, 1:129
acid reflux, 1:5–6
Abse, Dannie, 1:5
Ackerman, B. H., 4:1645
abuse:
ACL injury, 4:1602–1603
alcohol, 1:55–58
acne, 1:5–7
child, 1:381–383
acne vulgaris, 1:6–7
drug and substance, 1:420–422
acoustic neuroma, 1:7–8, 290
of elder populations, 2:591–593
Acquired Childhood Aphasia, 1:155
physical, 1:381, 382
Acquired Immune Deficiency Syndrome (AIDS),
sexual, 1:381, 382
1:36–41, 209, 210, 212, 253, 286, 334, 364,
spousal, 1:29
399, 443, 444, 454, 2:598, 793, 801, 841, 880, I-1
I-2
Index
908, 928–930, 933–934, 3:991, 995, 1018,
adrenal glands, 1:14–15, 2:599
1144, 1162–1163, 1424, 4:1481, 1482, 1504,
adrenocortical carcinoma, 1:24–25
1505, 1534, 1535, 1536, 1635, 1636, 1653,
adrenocorticotropic hormone (ACTH), 1:292
1697, 1698, 1775, 1776
Adult Congenital Heart Association (ACHA),
infections associated with, 1:41–43
1:25–26
living with, 1:44–46
adult immunization, 1:26–27
and pregnancy, 1:43–44
adult onset acne, 1:7
acquired immunity, 1:8–10, 2:919
advanced practice registered nurses (APRNs), 1:175
acquired mutation, 1:10, 4:1583–1584
Advisory Committee of Immunization Practices
Action for Clean Air Committees, 1:103
(ACIP), 1:82
active immunity, 1:8, 10–11
advocacy, 1:90, 91, 96, 103, 104, 105, 112, 115
active immunization, 2:882
aerospace medicine, 1:27–28
Activities of Daily Living (ADLs), 1:11–12, 69,
Afghanistan, 1:28–29
3:1228, 1379 acupuncture, 1:12–13, 65–66, 339 acute inflammatory demyelinating polyradiculoneuropathy (AIDP), 2:758
aflatoxins, 3:1022 Africa, 1:142, 285, 326–327, 333–334, 364–365, 370–371, 2:598, 783–787, 3:1050–1052 African-American health, 1:30–32
acute lymphangitis, 3:1043
African Meningitis Belt, 1:221, 321, 370
acute lymphocytic leukemia (ALL), 3:1014
African sleeping sickness, 3:1335, 4:1684, 1697
acute myelocytic leukemia (AML), 3:1015
Agency for Healthcare Research and Quality
acute renal failure, 3:975 acute respiratory distress syndrome (ARDS), 1:204 acute stress disorder, 1:153
(AHRQ), 1:32–33 Agency for Toxic Substances and Disease Registry (ATSDR), 1:33–34
Addison, Thomas, 1:14, 2:864
Agent Orange, 1:338, 2:610
Addison’s disease, 1:14–15, 4:1660
Age-Related Eye Disease Study (AREDS), 1:35
adenine (A), 2:713
age-related macular degeneration (AMD), 1:34–
adenomas, 3:1384
35, 269, 352, 2:647, 3:1178, 4:1487
adenomyosis, 2:765, 4:1728–1729
age-specific mortality, 3:1137
adenosine triphosphate (ATP), 1:316
aging, 1:119–120, 2:731–732, 736, 737, 3:1192–1194
Ader, Robert, 3:1444–1445
agoraphobia, 1:152
ADHA Institute for Oral Health, 1:97
AIDS-related malignancies, 1:47
Administration for Children and Families (ACF),
air pollution, 1:48–50, 180, 410, 2:523–524, 901–
1:15–16
902, 3:1394
Administration on Aging (AoA), 1:16–17
Air Pollution Control Act, 1:50
adolescent development, 1:17–19
airway hyperresponsiveness, 1:180
adolescent health, 1:19–23, 173
Alan Guttmacher Institute, 1:105
adoption medicine, 1:23
Alar, 1:122
Index
Albania, 1:51
amebiasis, 2:946
albinism, 4:1552–1553, 1554
amenorrhea, 2:764
Albrecht, Ruth, 2:736
American Academy of Addiction Psychiatry
alcohol attributable premature deaths (AAPD), 1:54 alcoholic liver disease, 3:1025 Alcoholics Anonymous (AA), 1:58 alcoholism, 1:55–58 alcohol use/abuse, 1:20, 52–55, 2:792, 866, 3:1194– 1195, 1206, 1246, 1255, 1415, 1424 Alexander II, 4:1503 Alexander III, 4:1503 Alexander the Great, 3:1391 Algeria, 1:59 allele, 1:59–60, 2:709, 725, 775–776 allelomorph, 1:59 Allen, Bennet, 2:601 allergic cascade, 1:354–355 allergic rhinitis, 1:62 allergy, 1:60–63, 2:879–880, 3:1131, 1181–1182 allograft, 1:63 allopathy, 1:64 Al-Najjar, Jamal, 4:1553 alopecia areata, 2:769 alpha error, 1:64–65 alpha fetoprotein (AFP), 3:1022 alpha radiation, 4:1463 alternative medicine, 1:65–68, 229, 393, 3:1114, 1166–1167 Alzheimer, Alois, 1:70, 3:1227 Alzheimer’s Association, 1:68–69 Alzheimer’s caregivers, 1:69–70 Alzheimer’s disease (AD), 1:70–72, 2:481–482,
I-3
(AAAP), 1:75 American Academy of Child and Adolescent Psychiatry, 1:183 American Academy of Family Physicians (AAFP), 1:75–76, 3:1181 American Academy of General Practice, 1:76 American Academy of Nurse Practitioners (AANP), 1:76–77 American Academy of Ophthalmology (AAO), 1:77–78 American Academy of Orthopedic Surgeons (AAOS), 1:78–79 American Academy of Pediatrics (AAP), 1:80, 183, 3:1181, 4:1626 American Association for Cancer Research (AACR), 1:81–82 American Association for Health, Physical Education, and Recreation (AAHPER), 1:93 American Association for Health Education (AAHE), 1:82–83 American Association of Orthodontists (AAO), 1:83–84 American Association of Retired Persons (AARP), 3:1096 American Burn Association, 1:322 American Cancer Society (ACS), 1:84–85, 98, 276, 338 American College Health Association (ACHA), 1:85–86
483–484, 3:1115, 1192, 1227–1228, 1445,
American College of Cardiology, 1:98
4:1568
American College of Epidemiology (ACE), 1:86–
Alzheimer’s Disease Education and Referral (ADEAR) Center, 1:73 amblyopia, 1:74
87 American College of Nurse-Midwives (ACNM), 1:87–88
I-4
Index
American College of Obstetricians and Gynecologists (ACOG), 1:88–89 American College of Occupational and Environmental Medicine (ACOEM), 1:89– 90 American College of Physicians (ACP), 1:90–91 American College of Preventive Medicine (ACPM), 1:92 American College of Rheumatology (ACR), 3:1038 American College of Sports Medicine (ACSM), 1:93–94 American College of Surgeons (ACS), 1:94–95 American Council for Fitness and Nutrition (ACFN), 1:95
American Osteopathic Association (AOA), 1:107– 108 American Pharmacists Association (APhA), 1:108–109 American Podiatric Medical Association (APMA), 1:109–110, 2:680 American Pregnancy Association (APA), 1:110– 111 American Psychiatric Association, 1:151, 152, 187, 319, 3:1063, 1104 American Psychological Association (APA), 1:111–112 American Public Health Association (APHA), 1:112–113
American Dental Association (ADA), 1:96–97
American Red Cross, 1:113–115
American Dental Hygienists’ Association
American Social Health Association (ASHA),
(ADHA), 1:97 American Diabetes Association (ADA), 1:98–99, 2:502, 506
1:115 American Society for Reproductive Medicine (ASRM), 1:116
American Fertility Association (AFA), 1:99
American Society of Addiction Medicine, 1:55
American Foundation of Urological Diseases
American Society of Bariatric Physicians, 1:107
(AFUD), 1:121 American Geriatrics Society (AGS), 1:100 American Health Care Association (AHCA), 1:100–101 American Heart Association (AHA), 1:101–102, 168, 2:634, 636, 639 American Lung Association (ALA), 1:102–103, 3:1144 American Medical Association (AMA), 1:103– 104, 108, 2:592, 3:1144 American Medical Women’s Association (AMWA), 1:104–105 American National Standards Institute (ANSI), 4:1510
American Society of Clinical Oncology (ASCO), 1:116–117 American Society of Clinical Pathology (ASCP), 1:118 American Society of Human Genetics (ASHG), 1:118–119 American Society of Internal Medicine (ASIM), 1:90 American Society on Aging (ASA), 1:119–120 American Stroke Association, 1:101 Americans with Disabilities Act, 1:85 American trypanomyiasis, 1:371 American Urological Association (AUA), 1:120– 121 Ames, Bruce, 1:121–123
American Nurses Association (ANA), 1:105–106
ametropia, 4:1473–1474
American Obesity Association (AOA), 1:106–107
amphetamines, 1:123–125, 3:1416
Index
amphibole asbestos, 1:167 amputation, 1:165–166
I-5
anterior cruciate ligament (ACL) injury, 4:1602– 1603
amputees, 1:125–126
anthrax, 1:144–145, 229, 231, 232, 238–239, 3:1202
Amyotrophic lateral sclerosis (ALS), 1:311, 2:482,
anthropometrics, 2:753, 756
3:1029–1030, 1153, 1187, 1226–1227, 1232,
antibiotics, 1:145–148, 3:1370, 4:1632, 1684
1233
antibodies, 1:8–10, 193
Anabolic Steroid Control Act, 1:127
antidiuretic hormone (ADH), 3:1383
anabolic steroids, 1:126–127
antigens, 1:193
anabolism, 3:1118
Antigua, 1:148–149
anal cancer, 1:127–129
antineutrophilic cytoplasmic antibodies (ANCA),
anal/rectal diseases, 1:129–132
4:1738
analytical toxicology, 4:1674
antinuclear antibodies (ANA), 3:1456
anaphylaxis, 1:62, 2:670–671
antioxidants, 1:149–150
anaplastic thyroid cancer, 4:1664–1665
antiretroviral therapy (ART), 1:42, 46
anatomy, 2:473–474
anti-venom, 3:1340
ancillary mental health providers, 3:1112
anus, disorders/diseases of, 1:129–132, 3:1426
Andorra, 1:132–133
anxiety, 2:496
Andre, Nicholas, 3:1294
anxiety disorders, 1:150–154, 3:1115
androgenic steroids, 1:126–127
aortic valve insufficiency, 2:815–816
androgens, 1:6
aortic valve stenosis, 2:815, 819
anemia, 1:133–135, 281–282, 2:824
Apert, Eugene, 1:253
anencephaly, 1:297
Apert’s syndrome, 2:778
anesthesia, 4:1632, 1633
APGAR score, 2:903
aneurysms, 1:135–139
aphasia, 1:155–156, 4:1588
Angell, Marcia, 3:1074
aplastic anemia, 1:281
Angelman syndrome, 1:253
apoptosis, 3:1427
angina, 1:139–140
appendicitis, 1:156
angioplasty, 1:140–141
Appia, Louis, 2:932
Angle, Edward Hartley, 1:83
apraxia, 4:1588
Angola, 1:142
archaea, 1:206
Anholt, R., 4:1645
Argentina, 1:157–158, 2:800–801
animal physiology, 3:1381
Aristotle, 3:1377, 1433, 1440
ankle sprains, 2:681
Armenia, 1:158–159
ankylosing spondylitis, 1:163, 3:1213
Armstrong, Bruce, 3:1283
Annie E. Casey Foundation, 1:173
arm/wrist injuries and disorders, 4:1768–1771
anorexia nervosa (AN), 1:20, 143–144, 273, 2:525,
aromatherapy, 1:66
577
arrhythmia, 1:159–160
I-6
Index
arteries, “hardening” of, 1:160–161
Astwood, Edwin B., 2:601
arteriosclerosis, 1:160–161
ataxia, 3:1142
arthritis, 1:161–165, 3:1182–1183, 4:1540–1541,
atherosclerosis, 1:160–161
1770–1771
athetosis, 3:1141
arthritis mutilans, 1:163, 164
Athletes Against Autism (Triple A), 1:192
arthropods, study of, 3:1078–1081
athlete’s foot, 2:679, 681–682, 4:1553
articular injuries, 2:852
Atiman, Adrien, 4:1644
articulation disorders, 4:1588
Atkins, Robert Coleman, 3:1259–1260
artificial insemination, 2:913
Atkinson, Richard L., 1:107
artificial intelligence, 3:1003
Atomic Energy Act, 2:489
artificial limbs, 1:165–166
Atomic Energy Commission, 2:489
asbestos/asbestosis, 1:166–169, 2:902, 3:1059–
atopic dermatitis (eczema), 1:61, 62, 2:497
1061
atopy, 1:60, 177
ascaris, 1:23
atresia, anal, 1:129
ascorbic acid, 4:1748–1749
atrial septal defect (ASD), 1:440, 2:814
Aselli, Gaspare, 3:1282
attention deficit disorder (ADD), 1:181–182, 384
aseptic necrosis, 3:1301–1302
attention deficit hyperactivity disorder (ADHD),
Asherman’s syndrome, 1:252 Asia and Oceania, healthcare systems in, 2:787– 791
1:123, 124, 182–183,
2:874, 3:1114
audiologists, 3:1309
Asian-American health, 1:169–171
Auerbach, Gerald, 2:601
Asperger, Hans, 1:188, 190
Augustus Frederick, 3:1147
Asperger’s syndrome, 1:187, 188–189
Aum Shinrikyo Cult, 1:238
Aspergillus, 3:1022, 1131
auricular microsystem, 1:13
association, 3:1100
Austen, Jane, 1:15
Association for International Cancer Research
Australia, 1:183–185, 2:789–790
(AICR), 1:172 Association of Maternal and Child Health Programs (AMCHP), 1:172–173 Association of Schools of Public Health (ASPH), 1:174 Association of Women’s Health, Obstetric, and Neonatal Nurses (AWHONN), 1:175–176 asthma, 1:30, 62, 176–179, 310, 4:1485 in children, 1:180–181 guidelines for treatment of, 1:178–179, 180 astrocytoma, 1:290, 292
Austria, 1:185–186 autism, 1:186–192, 3:1115 Autism Behavior Checklist, 1:191 Autism Diagnostic Observation Scale, 1:191 autism spectrum disorders (ASD), 1:186, 250 autoimmune arthritis, 1:162–163 autoimmune diseases (AD), 1:192–196, 2:880 autoimmune hepatitis, 3:1025 autoimmune lymphoproliferative syndrome (ALP), 3:1044 autoimmune myopathies, 3:1149
Index
autonomic nervous system (ANS), 1:292, 2:895, 3:1226, 1230 autosomal dominant polycystic kidney disease (ADPKD), 3:1398 autosomal recessive polycystic kidney disease (ARPKD), 3:1398–1399
Bailey, Ian, 4:1576 Baillie, Matthew, 3:1343 Baillou, Guillaume, 4:1759 Balk, Jannecke, 3:1427 ball and socket joint, 2:849–852 ballism, 3:1141
avascular necrosis (AVN), 2:851, 3:1301–1302
Balo, Joszef, 3:1147
Avery, Oswald T., 1:196–197, 2:722
Banda, Hastings, 2:786
Averzoar, 3:1281
Bandura, Albert, 1:17, 389
avian influenza (bird flu), 1:197, 242–245, 362,
Bangladesh, 1:210–211
2:612, 675, 917, 4:1484, 1678, 1742
Bannister, Roger, 3:1230
aviation medical examiners (AME), 1:28
Barbados, 1:211–212
Avicenna, 2:947, 3:1136, 1281, 1371, 4:1522, 1644
Barbellion, W. N. P., 3:1147
avoidant disorder, 1:151, 152
Barbuda, 1:148–149
Axelrod, Julius, 1:197, 3:1368
Bardet, Georges Louis, 1:253
Ayim, Emmanuel N., 2:786
Bardet-Biedl syndrome, 1:253
Ayurvedic medicine, 1:65, 66, 2:838
Barham, Jay, 3:987
Azerbaijan, 1:198
barium X-ray, 4:1614 Barker, L. R., 4:1646
B
Barnard, Christiaan, 1:348, 2:785, 818, 3:1292
Baby Boomers, 3:1105
Barré, Jean Alexandre, 2:758
Bacillus anthracis, 1:144–145, 232, 238–239
Barrett’s esophagus, 1:5, 6, 4:1616
Bacillus cereus, 2:674
Barton, Clara, 1:113, 2:939
background radiation, 1:199–200
bartonellosis, 3:1138
back injuries, 1:200–201
basal ganglia, 2:482, 869–870, 3:1140, 4:1468
back pain, 1:201–203
Basedow’s disease, 4:1664
bacteremia, 1:205
base excision repair, 1:212–213
bacterial infections, 1:203–206
base repair (bp), 1:213
bacterial meningitis, 3:1101–1102
base sequence, 1:213–214
bacterial physiology, 3:1381
Bassi, Agostino, 3:1450
bacterial vaginosis (BV), 4:1535, 1733–1734
Bastyr, John, 3:1208
bacteriology, 1:206–208
Battle’s sign, 3:1310
Badham, Charles, 1:408
Bavolek, Cecilia, 2:740
Bagshaw, Malcolm, 3:1282
Bayley Scales of Infant Development, 2:499
Bahamas, 1:208–209
B cells, 1:61, 193, 195, 2:879, 881, 885
Bahrain, 1:210
Beach, Wooster, 2:836
Bailar, John Christian III, 3:1283
Beadle, George Wells, 3:1003
I-7
I-8
Index
Beals, Rodney K., 1:214
beta radiation, 4:1463
Beals-Hecht syndrome, 1:214
Bettelheim, Bruno, 1:190
Beck, Aaron, 3:1110, 1437
Bevan, Aneurin, 4:1703
Becker, Peter Emil, 3:1151
Beveridge, Charles E. G., 2:785
Becker’s muscular dystrophy (BMD), 3:1151
Bhutan, 1:225–226
bed sores, 4:1700
biceps tendonitis, 4:1600–1601
Beers, Clifford W., 3:1201
Biedl, Arthur, 1:253
Behring, Emil von, 2:883
Bignami, Amico, 3:1053
Beijerinck, Martinus W., 1:215
bile, 2:694–695
Belarus, 1:215–216
bile duct cancer, 1:226–227
Belgium, 1:216–218
bile duct/gallbladder diseases, 2:694–696
Belize, 1:218–219
Bilharzia, 4:1523
Bell, Alexander Graham, 3:1243
Bill and Melinda Gates Foundation, 3:1452
Bell, Charles, 1:219–220, 221
Billings, John Shaw, 3:1197
Bell, John, 1:219
Binder, William, 4:1553
Bell, Paul, 2:601
binge drinking, 1:52
Bell’s palsy, 1:219, 220–221
binge eating, 2:577–578
Belorussia, 1:215–216
bingeing and purging, 1:319
Ben Aberazerim, Bulchasim, 3:1371
Binkley, Neil, 3:1306
Benacerraf, Baruj, 3:1136, 1147
biochemical cascade, 1:354–355
Beneden, Edouard van, 1:406
biochemistry, 1:227–228
Benedict, Jeff, 3:1301
biodefense, 1:228–229
Benedict, Ruth, 3:1104
biodegradable, 3:1394
benign breast diseases (BBDs), 1:301–302, 305
bioengineering, 3:1184
benign prostatic hyperplasia (BPH), 1:262, 375,
biofeedback, 1:229–230, 3:1114
3:1428, 1430–1431 Benin, 1:221–222 Bennett, Arthur, 3:987 bereavement, 1:222–224 beriberi, 1:224–225, 4:1746
bioinformatics, 1:230–231 biological and chemical weapons, 1:231–233, 4:1563 Biological and Toxin Weapons Convention (BTWC), 1:237, 240
Bernard, Claude, 2:600, 862, 3:1342
biological warfare, 1:228–229, 2:610
Bernard-Soulier disease, 1:264
biomarker, 1:234
Berson, Solomon A., 2:601
biomedical imaging, 3:1184
Berthold, Arnold Adolph, 2:600
biopesticides, 3:1360
Bertillon, Jacques, 2:930
bioprospecting, 1:208
Best, Ruth S., 2:786
biopsy, 3:1280, 1312
beta error, 1:64, 225
biopsychiatry, 3:1437
Index
biosafety, 1:235–237
Blount’s disease, 3:1004
bioterrorism, 1:229, 237–240
B-lymphocytes (B-cells), 1:9
biotherapy, 1:240–241
Boadicea, Queen, 4:1628
biotin, 4:1748
body cell mass, 1:272
bipolar disorder, 3:1063–1065, 1115, 1188
body image, 1:20
body mass index (BMI), 1:272–273, 2:509, 814,
See Manic Depressive Illness
bird flu (avian influenza), 1:197, 242–245, 362, 2:612, 675, 917, 4:1484, 1678, 1742
3:998, 999, 1261, 1263 body surface area, 1:273–274
birth, breech, 1:312
Bohan, A., 3:1149, 1157
birth cohort, 1:246
Bolivia, 1:274–275, 2:797–798
birth control/contraception, 1:1, 12, 246–250,
Bonadonna, Gianni, 3:1283
2:766–767
I-9
Bonaparte, Napoleon, 2:938
birth defects, 1:250–254, 3:1174–1175
bone cancer, 1:276–277
birthmarks, 1:254–255
bone diseases, 1:277–279, 3:1319–1322
birth rate, 1:255–256
bone health, 1:280–281, 283, 331
bisexual, 1:256–257
bone marrow diseases, 1:281–282
Bissell, Emily, 1:102
bone marrow transplant, 1:282, 392
bithorax complex, 3:1017
bone mass density (BMD), 1:282–283, 3:1306
Black, James, 3:1368
bone mineral density, 1:283–284
Black Death, 2:477, 612, 667, 3:1083
bones, fractures of, 2:685, 773, 851, 4:1540, 1599,
black flies, 3:1279
1602, 1603, 1769–1770
Blackwell, Elizabeth, 1:257–258
bone tumors, 1:391
bladder cancer, 1:258–259, 262
Bono, 3:1452
bladder diseases, 1:259–262
Bordet, Jules, 2:883, 4:1760
bleeding disorders, 1:263–266
Borel, Raymond, 3:1095
blepharitis, 1:266–267, 2:646
Borgia, Cesare, 3:1391
blepharospasm, 1:267–268
Borrelia burgdorferi, 3:1040–1042
Bleuler, Eugen, 3:1435
Bosetti, C., 2:622
blindness, 1:268–270, 356–357
Bosnia and Herzegovina, 1:284–285
blister agents, 1:233
Botkin, Eugene, 4:1503
Bloch, Felix, 3:996
Botkin, Sergei, 4:1503
blood agents, 1:233
Botswana, 1:285–286
blood/blood transfusion, 1:270–272, 4:1719–1720,
botulism, 1:232, 286–287
1757 blood pressure, 2:846–847, 3:972, 1030–1031 blood urea nitrogen (BUN), 3:972, 1218 Bloomberg, Michael, 3:1452
Bourns, Frank S., 3:1376 bovine spongiform encephalopathy (BSE), 1:287– 289, 2:675 bowel, inflammatory diseases of, 2:913–915
I-10
Index
Bowen’s disease, 3:1058, 1351
Brock, Norbert, 3:1283
boxer’s knuckle, 4:1602
Brodie, Bernard, 1:197
Boyle, Robert, 1:228
Brokaw, Tom, 1:192
Braasch, William F., 4:1724
bronchiectasis, 4:1486
BRACA2 gene, 1:302, 306
bronchitis, 1:312–314, 4:1485
brachytherapy, 1:377–378
bronchodilators, 1:178, 180
Braid, James, 3:1435
Bross, Irwin D. J., 1:314
brain and head injuries, 2:776–778
Brown, Barbara B., 1:230
brain aneurysms, 1:138–139
Brown, L. M., 2:622
Brain Awareness Week (BAW), 3:1237
Brown, Louise, 1:315
brain cancer, 1:289–292, 337
Brown, Michael, 2:660
brain dead, 1:432
Brown, Michael Stuart, 1:315–316
brain diseases, 1:292–295, 3:1016
brown fat, 1:316
brain disorders, genetic, 2:717–718
Brown-Séquard, Charles-Édouard, 2:600
brain injuries, 1:295–296, 430–433
Brucellosis, 1:232–233
brain malformations, 1:297–298
Brücke, Erich von, 2:594
brain stem glioma, 1:290
Brunei, 1:316–317
brain tumors, 1:391
Bruner, Jerome, 3:1442
Braxton, Toni, 1:192
bubonic plague, 1:239–240
Brazil, 1:298–299, 2:797
Budd, W., 1:411
BRCA1 gene, 1:302, 306
Budd-Chiari syndrome, 3:1025
breast cancer, 1:10, 32, 299–304, 305, 306, 337, 342,
Bulgaria, 1:317–318
3:1163–1164
bulimia, 1:20, 318–320, 2:525, 577
breast diseases, 1:304–306
bunions, 2:680, 682
breastfeeding, 1:43, 46, 307–308, 435, 2:903, 907,
Bunke, Harry, 3:1125
3:1382, 4:1482
buprenorphine, 2:842
breast implants/breast reconstruction, 1:308–309
Burgess, Anthony, 2:827
breast self-exams, 1:302
Burkholderia mallei, 1:233
breathing problems, 1:310–311. See also
Burkina Faso, 1:320–321
respiratory diseases
Burkitt, Denis Parsons, 2:786
Breckinridge, Mary, 1:87
Burma (Myanmar), 3:1154–1155
breech birth, 1:312
burning mouth syndrome (BMS), 2:651–652
Brenner, Sydney, 3:1427
burns, 1:321–323
Bright, Richard, 1:14
bursitis, 1:323–326, 2:851, 4:1600, 1601, 1602
British Cohort Study, 1:246
Burundi, 1:326–327
Broca, Paul, 2:867
Bush, George H. W., 3:968
Broca’s aphasia, 1:155
Bush, George W., 1:69, 171, 433, 4:1481, 1482
Index
Bush, Jeb, 1:433
cannabis sativa, 3:1068–1070
Bushido, 4:1628
cannibalism, 1:288
I-11
Cannon, Walter Bradford, 2:600, 3:1230 C
Cape Verde, 1:343–344
Cabrinovic, Nedeljko, 3:1391
carbohydrates, 2:525
caesarian section (C-section), 1:312
carbon monoxide, 2:902
café-au-lait spots, 3:1225
carcinoembryonic antigen (CEA), 1:227
caffeine, 1:329–330
carcinogens, 1:121–122
Calabresi, Paul, 1:330–331
carcinoid tumors, 1:344–345
calcium, 1:331–332, 3:1336–1337
carcinoma of unknown primary, 1:345–346
calicivirus, 1:229
cardiogenic syncope, 2:654–655
California Proposition 128, 1:122
cardiology, 1:347–350, 4:1777
Cambodia, 1:332–333
cardiomyopathies, 2:815–816
Cameroon, 1:333–334
cardiopulmonary resuscitation (CPR), 1:113, 2:478
Camper, Pieter, 1:455
cardiovascular diseases (CVDs), 2:816–818
Campylobacter, 2:674, 676, 677
cardioversion, 1:350–351
Camus, Albert, 2:786
cardologists, 1:346–347
Canada, 1:334–336, 2:801–805, 924
caregivers, 1:351
cancer, 3:1279–1280
Carlsson, Arvid, 3:1369
alternative therapies for, 1:339–340
carotenoid, 1:352
of blood (leukemia), 3:1013–1015
carotid endartectomy, 1:141
carcinogenic causes, 1:121–123
carpal tunnel syndrome (CTS), 1:352–353, 2:772,
chemotherapy for, 1:340–341
4:1768–1769
childhood, 1:389–393
Carrel, Alexis, 3:1292
coping with, 1:341–342
Carson, Rachel, 1:338, 2:610, 3:1282, 1390, 1452
general information, 1:336–339
Carswell, Robert, 3:1147
metastatic, 1:338, 345
Cartagena Protocol on Biosafety, 1:236–237
prevention of, 1:339
Carter, Jimmy, 2:491, 659, 3:1188, 1452
radiation therapy for, 1:343
Carter, Rosalyn, 3:1188
research in, 1:81–82, 172
Casals-Ariet, Jordi, 1:354
subspecialties of, 1:116–117
cascade, biochemical, 1:354–355
treatments of, 1:330–331
case-control studies, 1:355
See also specific organ, system or tissue
case crossover studies, 1:458–459
Cancer Prevention Study, 1:427
Castleman, Benjamin, 3:1044
cancer registries, 3:1202–1203, 4:1686–1688
Castleman disease, 3:1044
cancer survivorship, 3:1176
Castro, Fidel, 1:462
Candida, 1:42, 4:1661, 1734–1735
catabolism, 3:1118
I-12
Index
cataphoresis, 2:707
cervical intraepithelial neoplasia (CIN), 1:367
cataract, 1:268–269, 356–357, 2:646, 3:968
cervical spine, 1:369–370
cauda equina syndrome, 4:1592
cervical spondylosis, 3:1213, 4:1592–1593
cause-specific mortality, 3:1137
Ceylon, 4:1605–1606
Caverly, C. S., 3:1395
Chad, 1:370–371
Cavuto, Neil, 3:1147
Chagas disease, 1:371–372, 4:1684
celiac disease, 1:357–358
Chain, Ernest, 1:146
cell death, programmed, 3:1427
Chamberland, Charles, 3:1341
cell-mediated responses, 1:9
Charcot, Jean-Martin, 3:1147, 1230, 1338
cellulitis, 1:204, 358–359
Charcot-Marie-Tooth disease, 3:1153, 1356
centenarian, 1:359–360
Charles, Marie, 2:929
Center for American Nurses, 1:106
Charles I, 2:856
Center for Food Safety and Applied Nutrition
Charles II, 2:856
(CFSAN), 1:360–361 Centers for Disease Control and Prevention (CDC), U.S., 1:10–11, 29, 31, 32, 33, 113, 168, 180, 187, 232, 235, 237, 244, 361–362, 2:513,
Chauliac, Guy de, 3:1282, 4:1631 Chekhov, Anton, 1:372 chemical and biological weapons, 1:231–233, 4:1563
613, 3:1167, 1168, 1171, 1173, 1181, 1453,
chemical mutagens, 1:121–122
4:1625, 1627, 1678, 1679
chemical sensitivities, 3:1144–1145
Centers for Medicare and Medicaid Services (CMS), 1:363
chemokines, 1:373 chemokinesis, 1:373–374
Central African Republic, 1:364–365
chemoprevention, 1:374–377
Central American Free Trade Agreement (CAFTA),
chemoradiotherapy, 1:377–378
2:589
chemotherapy, 1:338, 339, 378–379, 392, 429
central geographic atrophy (CGA), 1:34
Chen, Zhong Wei, 1:379–380
central nervous system (CNS), 1:290, 292, 311,
Chernobyl nuclear accident, 1:216, 338, 389, 2:604,
3:1222, 1226, 1230 central retinal artery occlusion (CRAO), 4:1487 central retinal vein occlusion (CRVO), 4:1487
610, 675, 927, 3:1390 chickenpox, 1:26, 220, 380–381, 2:908, 3:1202, 4:1491
cerebellar dysfunction/tremor, 3:1142
child abuse, 1:381–383
cerebral aneurysms, 1:138
Child Behavior Checklist, 1:384
cerebral palsy, 1:254, 365–367
child behavior disorders, 1:383–384
cerebrospinal fluid (CSF), 1:8, 2:870–871, 3:1101–
childbirth, 3:1126–1127, 1413–1414
1102
child development, 1:385–389
cerebrovascular accidents (CVAs), 4:1623
childhood cancers, 1:389–393
cerebrovascular disease (CVD), 1:293–294
childhood disintegrative disorder (CDD), 1:187, 189
cervical cancer, 1:32, 337, 367–369, 2:766
childhood immunizations, 1:11, 393–394, 3:1181
Index
child mental health, 1:394–396
choroidal neovascularization (CNV), 1:34
children:
choroid plexus tumors, 1:290
I-13
accidental poisonings of, 3:1389–1390
chromosomes, 1:406, 467–468, 2:774
asthma in, 1:180–181
chronic fatigue syndrome (CFS), 1:406–407
care of, 3:1348–1349
chronic inflammatory demyelinating polyneuropathy
dental health of, 1:384–385
(CIDP), 3:1356
depression in, 2:496
chronic lymphocytic leukemia (CLL), 3:1014–1015
exercise for, 2:633–634
chronic myelogenous leukemia (CML), 3:1015
growth and development of, 2:904–907
chronic obstructive pulmonary disease (COPD),
hearing problems in, 2:809–810
1:176, 310, 313, 314, 408–410, 2:595, 3:1036,
hip injuries and disorders in, 2:849–850
4:1483, 1485
incontinence problems of, 2:896–897
chronic renal failure, 3:975–976
institutionalization of, 3:1349
chronic wasting disease (CWD), 1:288
Children’s Environmental Health Centers, 1:191
chronology of global health, 1:410–412
Children’s Heart Foundation, 1:26
Churchland, Patricia, 1:456
Child-Robot with Biominetic Body (CB2), 2:907
Churg-Strauss syndrome, 4:1738
child safety, 1:396–397
circadian rhythms, 1:412–414
Chile, 1:397–398, 2:798
circumcision, 2:903
China, 1:242, 244, 245, 398–401, 2:837–838
cirrhosis, 1:226, 265, 414–415
Chinese Classification of Mental Disorders, 3:1438
Civil Rights Act, 1:30
Chinese Medicine, Traditional (TCM), 1:400,
cladograms, 3:1378
402–403, 2:837–838
clavicles, fractures of, 4:1599
chiropractic profession, 1:403–404
Clean Air Act, 1:50
chiropractic system, 1:66
cleanliness, 2:872–873
chlamydia infections, 1:22, 368, 404–405, 4:1534,
cleft lip and palate, 1:253, 415–416
1674
climacteric, 1:416–417
choking agents, 1:233
clinical breast exams (CBE), 1:306
cholangiocarcinoma, 1:226–227
clinical oncology, 1:116–117
cholecystitis, 2:695–696
clinical pathology, 1:118, 3:1344–1345
choledocholithiasis, 2:696
clinical psychology, 3:1112, 1439
cholelithiasis, 2:695
clinical toxicology, 4:1674
cholera, 1:405, 411, 2:612, 613, 909, 3:1083, 1239,
clinical trials, 1:417–418
1451, 4:1582, 1678, 1683 cholesterol, 1:315, 406, 2:634, 811, 814, 3:1175– 1176, 1362, 4:1676, 1720
Clinton, Bill, 3:1189, 1451, 4:1481 clone/cloning, 1:418–419, 4:1608 Closing the Health Gap Campaign, 1:31
chondrosarcoma, 1:276
Clostridium botulinum, 1:232, 286
chorea, 3:1141
Clostridium perfringens, 2:674
I-14
Index
Clostridium tetani, 4:1655
colonoscopy, 1:129–130, 427, 428–429
clotting disorders, 1:263–266
colon polyps, 1:426, 2:704
club drugs, 1:420
color blindness, 2:645
club foot, 3:1004
colorectal cancer, 1:426–429
cluster headaches, 2:782
colorectal surgeons, 3:1426
coagulation factors, 1:264–265
color therapy, 1:68
coarctation of the aorta (COA), 1:439, 441
colpocephaly, 1:297
cobalamin (B12), 4:1748
coma, 1:430–433
Cobbett, John, 3:1125
Combating Autism Act, 1:191–192
cocaine abuse, 1:420–422, 3:1416
Combe, Andrew, 3:1377
Codex Alimentarius Commission, 2:677
Combe, George, 3:1377
coding/sense strand, 1:213
Committee on Scientific Research, 1:104
codons, 2:723, 3:1248, 1388, 1400
common cold, 1:433–436, 4:1483–1484
coefficient of inbreeding, 1:422–423
Commonwealth Fund, 1:173
coffee, 1:329
communication and speech disorders, 3:1195–
Cogan’s syndrome, 3:1310 cognitive behavioral therapy (CBT), 1:320, 384 cognitive development, 1:387–388
1196, 4:1587–1589 Communication and Symbolic Behavior ScalesDevelopment Profile, 1:191
cognitive psychology, 3:1441–1442
community-acquired pneumonia, 1:45, 3:1386
Cohen, Nicholas, 3:1444, 1445
comorbidity, 2:731, 732
Cohen, Ruth Schwartz, 2:697
Comoros, 1:436–437
Cohn, F., 1:206, 411
complementary and alternative medicine (CAM),
cohort studies, 1:423
1:65–68, 229, 2:831, 833, 3:1114, 1166–1167
colds/cold virus, 1:433–436, 4:1483–1484
complete blood count (CBC), 3:1014
colitis, 1:131
complex humanitarian emergency (CHE), 1:437–
Collaborative Programs of Excellence in Autism (CPEA), 1:191 Collaborative Study on the Genetics of Alcoholism (COGA), 1:53 collagen, 4:1527
438 complex regional pain syndrome (CRPS), 4:1472– 1473 compound heterozygote, 2:845 Comprehensive Environmental Response
collagen vascular disease, 1:290
Compensation and Liability Act (CERCLA),
College Drinking Prevention, 3:1195
1:33
Collins, James, 3:1090
compression neuropathy, 4:1768–1769
Colombia, 1:424, 2:799
compression of spinal cord, 4:1593
colon, disorders of, 3:1426
computerized tomography (CT), 1:200, 2:516, 864
colon cancer, 1:337
concussions, 1:438–439, 4:1599
colonic diseases, 1:425
condoms, 1:248, 249, 4:1481, 1482
Index
I-15
conductive hearing loss, 2:474
cornea/corneal diseases, 1:449–450
congenital adrenal hyperplasia, 4:1470
coronary artery bypass graft (CABG), 1:141, 2:812
congenital heart defects, 1:25–26
coronary artery disease (CAD), 1:140, 2:813–814
congenital heart disease, 1:439–443, 2:814–815
coronary disease (CD), 1:450–452
Congenital Heart Information Network, 1:26
coronary heart disease (CHD), 2:504
congenital kidney diseases, 3:973
coronavirus, 1:433–434, 4:1532
congenital muscular dystrophy (CMD), 3:1152
cortex, degenerative disease of, 2:481–482
congenital rubella syndrome, 4:1502
cortisol resistance, 2:755
congestive heart failure (CHF), 1:311, 349
Cosby, Bill, 1:192
Congo, 1:443–444
cosmetics, 1:360–361
Congo, Democratic Republic of the (DRC), 1:444–
Costa Rica, 1:452–453
445 conjunctivitis, 1:445–446, 2:646 connective tissue disease (CTD), 1:446–447, 4:1471–1472
Côte d’Ivoire, 1:453–454 Council on Naturopathic Medical Education (CNME), 3:1209 Cowdry, Edmund V., 2:736
consanguinity, 2:893
cowpox, 4:1563
consciousness, 1:430–433, 2:653–656
Cox, David, 3:1282
Consolidated Omnibus Budget Reconciliation Act
Coxiella burnetii, 1:232
(COBRA), 2:598
cranial nerves, 1:7–8, 220, 221, 4:1645
constipation, 1:447–448, 2:529–530, 701
craniofacial disorder, 2:649
contact dermatitis, 2:497–498
craniology, 1:454–455
continuing medical education (CME), 1:121
craniometry, 1:454–455
contraception/birth control, 1:1, 12, 246–250,
craniopharyngioma, 1:291, 3:1384
2:766–767
craniosynostosis, 2:778
Controlled Substances Act, 3:1421
Crateuas, 3:1368
conventional medicine, 1:448–449
Creutzfeldt-Jakob disease (CJD), 1:287, 2:675, 4:1678
convulsive disorders, 1:294
crib death. See sudden infant death syndrome (SIDS)
Cook, James, 4:1670
Crichton-Browne, James, 2:867
Cook, Robert E., 3:1185
Crick, Francis, 4:1756
Cooper, Irving, 1:461
Crick, Francis, 1:456–457
coping with stress, 4:1622
Croatia, 1:457–458
copper, 4:1761–1763
Crohn’s disease, 1:131, 164, 192, 194, 427, 2:701, 704,
“copycat drug,” 3:1074
913, 914
Cordus, Valerius, 3:1371
Cronin, Thomas, 1:308
co-relational studies, 3:1443–1444
Cross, Claude, 3:1436
Corfield, William Henry, 2:873
crossing over, 1:458
Cormack, Allan, 4:1466
crossover studies, 1:458–459
I-16
Index
cross-sectional study, 1:459–460
cystoscopy, 4:1724
Crouzon’s disease, 2:778
cytogenetics, 1:467–468
cruciate ligaments, 4:1602–1603
cytokines, 1:373, 468–469, 2:887
crude birth rate (CBR), 1:255–256
cytomegalovirus (CMV), 1:43, 45, 3:1024, 1178,
crude death rate, 2:480
4:1488
crude mortality rate (CMR), 1:460, 3:1136
cytosine (C), 2:713
Cruveilhier, Jean, 3:1147
cytotoxic T lymphocytes, 2:916
Cruzan, Nancy Beth, 1:432
Czaja, Albert, 3:1025
Cruzan v. Director, Missouri Department of Health,
Czech Republic, 1:469–470
1:432 cryonics, 1:461
D
cryopreservation, 1:460–461
DaFoe, Byron, 1:192
cryosurgery, 1:461–462
daily reference values (DRVs), 2:471
cryptococcal meningitis, 3:1102
Dale, Henry, 3:1368
cryptococcosis, 2:691
Dalton, Katharina, 3:1109
cryptosporidium, 2:945–946, 3:1316
Damásceno, R. G., 3:1053
crystalloid arthritis, 1:164
Dandy, Walter, 3:1234
Cuba, 1:462–463
Darlington, Cyril D., 1:406
Culpeper, Nicholas, 2:836
D’Arsonval Jacques-Arsène, 2:594
culture-bound syndromes, 1:320
Darwin, Charles, 2:472, 697, 723, 730, 3:1378
culture-specific anxiety disorders, 1:154
Darwin, Erasmus, 2:472
cumulative incidence, 2:895
Daschle, Tom, 1:231
Cure Autism Now Foundation, 1:192
date rape, 2:472–473
Curie, Marie, 2:600, 3:1282, 4:1466
Dausset, Jean, 2:669–670, 3:1147
Curie, Pierre, 3:1282
Davidson, E. W., 3:1053
Currie, Alastair, 3:1427
Da Vinci, Leonardo, 2:473–474
Curtis, Alva, 2:837
Davis, Nathan Smith, 1:104
Cushing, Harvey, 2:600, 864
Dawber, Thomas Royle, 2:686
Cushing’s disease, 1:292
Dawson, Lord, 3:1425
Cushing’s syndrome, 1:7, 24, 2:754
Day, Harry G., 2:668
cyanide, 1:233
deafness, 2:474–476, 3:1195–1196
Cyprus, 1:463–464
Deane, Leonidas, 3:1053
cystic fibrosis (CF), 1:254, 464–467, 2:716, 719,
death and dying, 2:476–480, 732, 3:986–987
845, 4:1486
death rate, 2:480–481
Cystic Fibrosis Foundation, 1:465
DeBakey classification system, 1:137
cystic medial degeneration, 1:137
Debierne, André-Louis, 4:1467
cystitis, 4:1721
decibels, 3:1243–1244
Index
I-17
decompression sickness (DCS), 1:28
developmental disorders, 1:293
decubitus ulcers, 4:1700
deviated septum, 3:1252
deep brain stimulation (DBS), 3:1228
Devic, Eugène, 3:1147
deep vein thrombosis (DVT), 3:1454
de Vieussens, Raymond, 1:347
defibrillation, 1:350
de Vries, Hugo, 2:730
degenerative arthritis, 3:1213
DeVries, William, 1:348
degenerative disorders, 2:499
Diabetes Care Coalition, 1:98
degenerative joint disease, 3:1297–1299, 4:1770
Diabetes Control and Complications Trial (DCCT),
degenerative nerve diseases, 2:481–483
2:504, 508
Degos, Laurent, 3:1283
diabetes insipidus (DI), 2:501
Delbrück, Max, 4:1756
diabetes mellitus (DM), 1:98–99, 168, 2:501–505,
dementia, 1:70–72, 2:483–484, 3:1115, 1228
599, 680, 817, 3:972, 1186–1187, 1329
demographic transition, 2:484–485
in African American populations, 1:30
dengue, 2:485–486, 3:1138, 4:1513, 1678, 1684,
and pregnancy, 2:505–506
1742 Denmark, 2:486–487 dental health, 1:96, 384–385, 2:487–489, 515, 761–762
See also Type 1 diabetes mellitus (T1DM); Type 2 diabetes mellitus (T2DM) diabetic eye problems, 2:511 diabetic foot problems, 2:512–513
dental hygiene, 1:97
diabetic ketoacidosis (DKA), 2:503, 507
dental pathology, 2:651
diabetic kidney problems, 2:513–514
deoxyribonucleic acid (DNA), 3:1242, 4:1464, 1520–
diabetic nerve problems, 2:514–515
1521, 1756–1757 base excision repair in, 1:212–213 structure, 1:456–457 Department of Energy (DOE), 2:489–490, 936 depression, 1:20, 2:492–496, 3:1049–1050, 1063, 1115, 1405–1408, 4:1568
diabetic retinopathy, 1:269–270, 2:647–648, 4:1487 diabetic teeth and gum problems, 2:515 Diagnostic and Statistical Manual of Mental Disorders, 4th edition (DSM-IV), 1:55, 143, 152, 183, 187, 273, 293, 319, 384, 395, 2:493,
depressive disorders, 2:492, 493
494, 499, 577, 3:1000–1001, 1063, 1069, 1114,
dermatitis, 2:497–498
1266, 1406, 1438
dermatology, 4:1550
diagnostic imaging, 2:516–517
dermatomyositis, 3:1149–1150, 1157
diagnostic tests, 2:518–520
dermatophytosis, 4:1553
dialysis, 2:521, 3:975–976
Derryberry, Mayhew, 3:1451
diarrhea, 1:204, 2:522–523, 529, 701, 3:1289,
Descartes, 3:1440
4:1582, 1680
descending aortic syndrome, 4:1737
Diaz, Francisco, 4:1724
developmental disabilities, 2:498–500, 3:1174–
Dick, George Frederick, 3:1344
1175
Dickens, Charles, 1:15
I-18
Index
diesel exhaust, 2:523–524
Doctors Without Borders (MSF), 3:1095–1096
Dietary Supplement Heath and Education Act
Doll, Richard, 1:338, 355, 2:614, 3:1036, 1282
(DSHEA), 1:66
dominant allele, 1:60
dietary supplements, 1:66, 3:1314–1315
dominant inheritance, 2:724, 845
diet/diet plans/dieting, 2:524–527
Donaldson, Mary, 1:257
diethylstilbestrol (DES), 1:368, 4:1732
Donald W. Reynolds Foundation, 1:100
digestive diseases, 2:528–531, 3:1186–1187
Dooley, Tom, 3:995
digital rectal exam (DRE), 1:128, 129
Dorn, Friedrich Ernst, 4:1467
Dignity in Dying, 4:1752
Dottering, C. T., 1:140
dilatation and curettage (D&C), 1:4, 4:1727
Down, John Langdon, 1:252
Dioscorides, 2:836
Down syndrome, 1:252, 2:721, 754, 3:1111
dioxins, 2:674
Dracula, 3:1403
diphtheria, 1:11, 149, 2:531–532, 882, 908
Drinker, Cecil, 2:585
Diplococcus pneumonite, 1:196
Drosophila fly, 3:1017
diplopia, 2:646
drug abuse and addictions, 2:792–793, 3:1196–1197,
directly observed therapy strategy (DOTS), 4:1685
1370
direct-to-consumer advertising, 3:1363
drug-induced depression, 2:492
Disabilities Education Improvement Act (IDEIA),
drug-induced myopathies, 3:1150
3:1001
drug resistant bacteria, 1:205–206, 4:1607
disability adjusted life years (DALYs), 1:178
Druker, Brian J., 3:1282
Disaster Preparedness and Medical Response,
dry beriberi, 1:224
1:104 disasters and emergency preparedness, 1:113– 114, 437–438, 2:532–533, 659–660, 3:1325– 1326 disease-modifying antirheumatic drugs (DMARDs), 4:1495
dry eye syndrome, 2:646 dual energy x-ray absorptiometry test (DEXA scan), 1:282, 283, 284 Du Bois-Reymond, Emil Heinrich, 2:594 Duchenne, Guillaume Benjamin Amand, 3:1151, 1230
disease vectors, 3:1078–1081
Duchenne’s muscular dystrophy (DMD), 3:1151
disfluent speech, 4:1588
Duchesne, Ernest, 1:145
dislocation, 2:851–852, 4:1539, 1599–1600
Duclaux, Emile, 3:1341
disseminated intravascular disorder (DIC), 1:264
Dufour, Guillaume Henri, 2:932
distal muscular dystrophy (DD), 3:1153
Dumas, Jean-Baptiste-André, 2:746
distress, 4:1619
DumDum fever, 3:1009
diurnal incontinence, 2:896–897
dumping syndrome, 4:1616
diverticulitis, 2:704
Dunant, Henri, 2:932, 938
DNA mismatch repair, 3:1128–1129
du Pré, Jacqueline, 3:1147
Dobson, Tamara, 3:1147
Dupuytren, Guillaume, 3:1343
Index
Dupuytren’s disease, 2:773–774
edema, 2:585
Durlacher, Lewis, 3:1387
Edinburgh Postnatal Depression Scale (EPDS),
dysentery, 2:909
I-19
3:1406
dyslipidemia, 2:817–818
Edward, Prince of Wales, 2:873
dysmenorrhea, 2:764
Edwards, Charles, 4:1689
dyspepsia, 2:700, 4:1615–1616
Edwards, Robert, 3:1269
dysphagia, 4:1661–1662
Edwin Smith surgical papyrus, 4:1631
dyspnea, 1:310, 311, 2:596, 3:1454
Egypt, 2:586–587
dysthanasia, 2:480
Ehlers-Danlos Syndrome, 1:136, 137, 139, 2:587–
dysthymia, 2:492, 494
588 Ehrlich, Paul, 2:588–589
E
Ehrlichia, 2:583–584
ear, nose, and throat (ENT), 3:1306–1307
Einhorn, Lawrence H., 3:1282
ear disorders, 2:573–574
Einstein, Albert, 4:1526
ear infections, 2:575–576
Einthoven, Willem, 1:349
Early Childhood Longitudinal Study, 1:246
Eiselberg, Anton Freiherr von, 2:746
Early Head Start, 1:15
Eisenhower, Dwight D., 2:491
East Timor, 2:576–577
Eisenmenger phenomenon, 1:443
eating disorders, 1:20, 143–144, 318–320, 2:577–
elbows, injuries and disorders of, 2:590–591
581, 3:1115
elder abuse, 2:591–593
Eaton-Lambert syndrome, 3:1149
Eldering, Grace, 4:1760
Ebbinghaus, Hermann, 3:1440
elderly/senior populations, 1:119–120, 2:635–636,
Ebert, Roger, 1:221
731–732, 736–737
Ebola virus, 1:232, 236, 361, 4:1697
electrocardiogram (ECG or EKG), 1:159, 347, 350
Eccles, John Carew, 2:594
electroconvulsive therapy (ECT), 2:495, 3:1446
Echinacea, 2:833, 835
electroencephalography (EEG), 1:230, 295
echolalia, 1:188
electromagnetic fields (EMFs), 2:593–594
Eco, Umberto, 3:1391
electromyogram (EMG), 1:230
ecogenetics, 2:581–582
electron microscopy, 2:517
E. coli infections, 1:204, 205, 264, 361, 2:582–583,
electrophysiology, 2:594–595
674, 676, 722, 4:1722
elephantiasis/filariasis, 2:665
ecotoxicology, 2:609–610
Elion, Gertrude B., 3:1368
ectoparasites, 2:583–584
Elizabeth I, 2:873
ectopic/tubal pregnancy, 2:765
Elizabeth II, 1:218, 4:1512
Ecuador, 2:584–585, 798–799
Elkin, Stanley, 3:1147
eczema, 1:60
Elkind, Mortimer M., 3:1282
Edelman, Gerald, 2:883
Ellwood, Paul, 2:806–807
I-20
Index
El Salvador, 2:589–590
Entamoeba histolytica, 2:946
Elston, Robert, 2:614
Enterococci, 1:204
Elwyn, Herman, 2:585
entomology, medical, 3:1078–1081
emergency, complex humanitarian (CHE), 1:437–
environmental health, 2:602–603, 920–921,
438 Emergency Medical Treatment and Labor Act (EMTALA), 2:802 emergency preparedness and disasters, 1:113– 114, 437–438, 2:532–533, 659–660, 3:1325– 1326 Emery-Dreifuss muscular dystrophy (EDMD), 3:1152
3:1167–1168, 1177, 1187–1188 environmental medicine, 1:89–90, 2:603–606 environmental pollution, 3:1393–1394 environmental tobacco smoke (ETS), 1:177, 2:608–609 environmental toxicology, 2:609–610, 4:1674 Enzyme-Linked Immunosorbent Assay (ELISA), 1:39, 45, 380, 2:611
emesis, 3:1210–1211
ependymoma, 1:291
emmetropia, 4:1473–1474
ephedra, 2:832
emotional abuse, 1:381, 382–383
epicondylitis, 3:1149, 4:1601, 1769
emotional development, 1:388–389
epidemics, 2:611–613
emphysema, 1:310, 2:595–597, 4:1485
epidemiologists, 2:613–614
empiric risk, 2:597
epidemiology, 1:86–87, 2:613, 614–615, 939–940,
Employment Retirement Income Security Act (ERISA), 2:597–598
4:1577 epidermoid cyst, 1:291
encephalitis, 1:294, 2:584, 3:1138
epidural anesthesia, 3:1071
endemic, 2:598–599
epidural hematoma, 2:777
endocarditis, 1:204
epigenetics, 2:616–617
endocrine diseases, 1:24–25, 2:599–600, 863
epilepsy, 2:617–618, 718, 866, 3:1229, 4:1529–
endocrinology, 2:600–601, 4:1660, 1761
1530
endolymphatic hydrops, 3:1101
episodic vertigo, 3:1100–1101
endometrial cancer, 2:766, 4:1726
epityphlitis, 1:156
endometriosis, 2:765, 4:1729
Epstein-Barr virus (EBV), 1:43, 47, 290, 2:855,
endoparasites, 3:1335 endoscopic retrograde cholangiopancreatography (ERCP), 1:227
3:1024, 1245, 4:1741 Equatorial Guinea, 2:618–619 equine encephalitis, 3:1138
end-stage liver disease (ESLD), 3:1026–1027
Erb, Wilhelm Heinrich, 3:1152
end-stage renal disease (ESRD), 2:513, 3:1096
Erb’s disease, 3:1152
Engel, George L., 3:1439
erectile dysfunction (ED), 2:888, 3:1058
Engels, E. A., 3:1245
Erikson, Erik, 1:18, 21, 22
engrams, 2:601–602
Eritrea, 2:619–620
enhanced physiologic tremor, 3:1142
erythrocyte sedimentation rate (ESR), 3:1401, 1456
Index
Escherichia coli. See E. coli infections
I-21
exercise, 2:526, 527
esophageal cancer, 1:5, 6, 2:620–623, 780
for children, 2:633–634
esophageal hiatus, 2:704
physical fitness, 2:636–640
esophageal ulcerations, 4:1616
for seniors, 2:635–636
esophagus, 1:5–6
exercise treadmill test (ETT), 2:640
esophagus disorders, 2:623–625
Expanding the Promise of Individuals with Autism
Esquirol, J. E. D., 3:1435 essential tremor, 3:1142, 4:1681
Act, 1:192 extensively drug-resistant (XDR) tuberculosis,
Este, Augustus Frederick d’, 3:1147
4:1684
Estonia, 2:625–626
external head injuries, 2:776, 777
estrogen replacement therapy (ERT), 2:626–627
extracorporeal shock wave lithotripsy (ESWL),
ethics, in global health, 2:743–744
3:973
Ethiopia, 2:627–628
extragonadal germ cell tumor (EGCT), 2:641
eugenics, 2:697
eyelids, disorders of, 1:266–26268
Euler, Ulf von, 3:1368
eye-movement desensitizing and reprocessing
Europe, healthcare in, 2:791–797 European Association for Cancer Research
(EMDR), 3:1448 eyes:
(EACR), 2:628–629
cancer in, 2:641–643
European Association for the Study of Obesity
care of, 2:644–645
(EASO), 2:629
diseases of, 2:645–648
European Biosafety Society, 1:235
See also vision
European Centre on Health of Societies in Transition (ECOHOST), 4:1691
F
European Food Safety Authority (EFSA), 2:630
Fabella, Jose, 3:1376
European Medicines Agency (EMEA), 3:1369–1370
Fabry, William, 3:1282
European Public Health Alliance (EPHA), 2:631
Fabry’s disease, 3:1118
European Public Health Association (EUPHA),
facial deformities, 2:651
2:631–632 European Union (EU), 1:457, 469, 2:631, 791–797 Euro-REVES, 1:12
facial injuries and disorders, 2:649–652 facioscapulohumeral muscular dystrophy (FSHD), 3:1151–1152
Eustachian tube, 2:573, 574, 809
failure to thrive, 2:652–653
eustress, 4:1619
fainting, 2:653–656
euthanasia, 2:479–480, 3:1086, 4:1752–1753
Fairbanks, Douglas, 1:114
Evans, R. D., 2:601
falls, 2:656–657
evidence-based medicine (EBM), 2:632–633
false negative, 2:657
evolution, 2:710
false positive, 2:657–658
Ewing’s sarcoma, 1:276
Family and Medical Leave Act, 1:85
I-22
Index
family planning, 1:246–250, 4:1479–1480
filariasis, 2:665, 3:1138
Fanconi, Guido, 3:1408
finger fractures, 2:773
Farmer, Paul, 2:658, 3:1452
Finland, 2:666–667
Fasting Plasma Glucose (FPG) Test, 1:98
Fischhoff, J., 4:1542
fatal familial insomnia (FFI), 1:288, 289, 2:719
fissures, anal, 1:130
fatigue, 1:341, 406–407
fistula, anorectal, 1:130
fats, 2:525, 526, 3:1246, 4:1521, 1675–1676, 1720–
fitness, 1:95
1721
Fitz, Reginald H., 1:156
fatty liver, 3:1025
flagellates, 3:1335–1336
fecal incontinence, 2:895, 896, 2:897
flash-lamp pumped pulsed dye laser (FPDL), 1:255
fecal occult blood test (FOBT), 1:428
flatworms, 4:1523
Federal Aviation Administration (FAA), 1:28
flavivirus, 2:486, 4:1757
Federal Emergency Management Agency (FEMA),
fleas/flea bites, 2:667–668
2:659–660
Fleming, Alexander, 1:145–146
fee for service, 2:661
Flemming, Walther, 1:406
Feingold, Ben F., 1:181
Florey, Howard, 1:146
feline spongiform encephalopathy (FSE), 1:288
flu/influenza, 2:915–917, 4:1484
Felke, Pastor, 2:950
flukes, 1:226
Felten, David L., 3:1445
fluorescence in situ hybridization (FISH), 1:468,
Felter, Harvey Wickes, 2:837
2:709
female circumcision, 1:364, 2:662
fluoride, 1:385, 2:668
female genital mutilation (FGM), 1:364, 370–371,
flu shots, 2:916, 917, 4:1742
2:620, 627, 662, 764–765, 954, 4:1482–1483,
folic acid, 2:669, 4:1748
1582
follicle stimulating hormone (FSH), 3:1107
Ferlay, Jacques, 2:623
follicular thyroid cancer, 4:1664
Ferrier, David, 2:867
folliculitis, 2:769
fertility, 1:99
Fondation Jean Dausset (CEPH), 2:669–670
fertility awareness (FA), 1:249
food additives, 2:960–961
fetal alcohol syndrome (FAS), 1:23, 57, 253, 2:662–
food allergy, 1:60, 2:525, 670–671
663, 3:1415, 1420 fever, 2:663–664
Food and Agriculture Organization of the United Nations (FAO), 2:671–672
fiber, 1:427, 428, 447
foodborne diseases, 2:678
Fibiger, Johannes, 3:1344
food contamination/poisoning, 1:286–287, 2:674–
fibroids, 2:765, 4:1728
676, 3:1390
fibromyalgia, 1:407
Food Guide Pyramid, 1:331, 2:525–526
fifth metatarsal fracture, 4:1603
food safety, 1:360–361, 2:630, 672, 673, 675, 676–
Fiji, 2:664–665
678, 794
Index
football finger, 4:1601–1602
Friedan, Betty, 2:736, 3:1105
foot/feet:
fright disorders, 1:154
care with diabetes, 2:512
Frost, Robert, 2:614
foot health, 2:679–681, 3:1387
Frost, Wade Hampton, 1:246
injuries and disorders of, 2:681–682, 3:1005–
functional incontinence, 2:896
1006 management of, 1:109–110
I-23
fungal infections, 2:690–692, 3:1132, 4:1553 fungus, 3:1131–1132
Forattini, Oswaldo, 3:1053 foreign bodies, 1:130–131
G
forensic medicine, 2:682–684
Gabaldón, Arnoldo, 3:1053
forensic pathology, 3:1344
GABA receptors, 1:56
forensic toxicology, 4:1674
Gabon, 2:693–694
Fowler, Lorenzo Niles, 3:1377
Gage, Phineas, 2:694
Fowler, Orson Squire, 3:1377
gait, disorders of, 3:1142
fractures, 2:685, 773, 776, 777, 851, 4:1540, 1602,
Galen, 1:240, 2:493, 3:1236, 1281, 1345, 1369,
1603, 1769–1770
4:1631, 1689
Fragile X, 3:1400
Gall, Franz Josef, 1:455, 3:1377, 1435
Framework Convention on Tobacco Control
gallbladder/bile duct diseases, 1:226–227, 2:694–
(FCTC), 1:409
696
Framingham Heart Study, 1:423, 2:686
gallbladder cancer, 2:696–697
France, 2:686–688
Gallo, Robert, 1:36
Francis, Thomas, Jr., 3:1451
gallstones, 2:701
Francisella tularensis, 1:232
Galton, Sir Francis, 2:697
Franklin, Rosalind, 1:456, 4:1756
Galvanic skin response, 1:230
Franz Ferdinand, 3:1391
Galvão, B., 3:1053
fraternal twins, 2:688–689
Gambia, 2:698
freckles, 4:1555, 1701
gamekeeper’s thumb, 4:1602, 1605
Freda, Vincent, 3:1269
gamma radiation, 4:1463
Fredrickson, Donald, 2:689–690
ganglioglioma, 1:291
Frei, Emil III, 3:1282
ganglion cysts, 2:772–773
Freire, Paulo, 3:1452
garlic, 1:376, 2:833
Freireich, Emil J., 3:1282
Garret-Jones, C., 3:1053
“French paradox,” 1:55
Garrod, Archibald, 2:717
Frerichs, Göre, 3:1053
Garza, Venustiano Carranza, 3:1123
Freud, Sigmund, 1:17, 151, 365, 389, 2:889, 3:1010,
gastric cancer, 4:1613–1614
1011, 1110, 1230, 1435, 1440, 1447 friable, defined, 1:167
gastric reflux, 2:700 gastroenterologists, 2:699
I-24
Index
gastroenterology, 2:699–702
genetic neuromuscular disorders, 4:1595–1596
gastroesophageal reflux, 2:702–703
genetics, 1:59–60, 118–119, 2:723–726, 775–776
gastroesophageal reflux disease (GERD), 1:5–6,
genetic testing and counseling, 2:721–722
2:530, 621, 4:1615, 1616, 1652
genetic transformation, 2:722
gastrointestinal bleeding, 1:129–130, 2:703–705
gene transfer, 2:712
gastrointestinal diseases, 3:1186–1187, 1352–1353,
Geneva Protocol, 1:237, 240
4:1560–1561 gastrointestinal inflammation, upper and lower, 2:704
Gengou, Octave, 4:1760 genital amputation, 1:126 genital disorders, male, 3:1057–1058
gastrointestinal stromal tumor (GIST), 4:1614
genital herpes, 2:726–727, 4:1534
gastroparesis (delayed gastric emptying), 4:1616–
genocide, 4:1504
1617
genomic imprinting, 2:727–728
Gatmaitan, Clemente S., 3:1377
genomic library, 2:728–729
Gaucher, Philippe, 2:705
genotype, 2:729–730, 3:1373
Gaucher’s disease (GD), 2:705–706, 3:1118
geographic information systems (GIS), 3:1083
gay genes, 2:706
geography, medical, 3:1081–1083
Gay-Related Immune Deficiency (GRID), 1:36, 2:859
George, David Lloyd, 3:1378
gel electrophoresis, 2:707
George III, 3:1147, 1403
gender-specific mortality, 3:1137
Georgia, 2:730–731
gene array analysis, 2:707–708
Gerberding, Julie, 1:347
gene knockouts, 3:983–984
Gerhardt, Reid, 3:1053
gene mapping, 2:708–710
geriatric failure to thrive, 2:652–653
gene polymorphisms, 3:1246
geriatrics, 1:100, 2:731–733
gene pool, 2:710–711
German measles (rubella), 1:11, 26, 253, 2:882, 908,
general adaptation syndrome (GAS), 4:1618–1619, 1620
3:1202, 4:1501–1502, 1744, 1745 Germany, 2:733–734, 924
general fertility rate (GFR), 1:256
germinoma, 1:292
generalized anxiety disorder (GAD), 1:153
germline mutation, 2:735
generalized scleroderm, 4:1527
germ theory, 2:615, 3:1342
generic drug, 2:712–713
gerontology, 2:736–737, 3:1192–1193
genes and gene therapy, 2:713–716
Gerow, Frank, 1:308
gene silencing, 2:711
Gerstmann-Straussler-Scheinker disease (GSS),
gene therapy, 2:884, 887
1:288, 289
genetically modified organisms (GMOs), 2:677–678
Gesell, Arnold, 1:386
genetic brain disorders, 2:717–718
gestalt therapy, 3:1448
genetic code, 2:718–719, 725–726
gestational diabetes, 1:98, 2:503, 848
genetic disorders, 2:719–720
Gestational Diabetes Act, 1:99
Index
gestational trophoblastic tumors, 2:765
glucocorticoid deficiency, 2:755
Ghadirian, P., 2:621
glucose, 2:874–875
Ghana, 2:738
glucose metabolism, 2:501–506
GHB, 2:473
gluten-induced enteropathy, 1:357
giant cell arteritis, 4:1737
GM2 gangliosidosis, 4:1647–1648
Giardia infection, 1:23, 2:701, 739, 946, 3:1316,
Goebbels, Josef, 3:1390
1335
I-25
Goering, Hermann, 3:1390–1391, 4:1628
Gibbon, John H., 3:979
goiter, 1:226, 2:745–746, 4:1667
Gibbon, John H., Jr., 2:740
Goldstein, Joseph L., 1:315
Giemsa Banding, 3:1027
Golgi, Camillo, 3:1053, 1236
Giesel, Friedrich O., 4:1467
gonadotropic releasing hormone (GnRH), 3:1106
gigantism, 2:755
gonorrhea, 2:746–747, 4:1534
Gilman, Alfred G., 3:1368, 4:1497
Goodpasture, E. W., 3:1344
ginger, 2:833, 834
Goodpasture’s disease, 4:1738
gingivitis, 2:515, 761
Goodwin, J., 3:1294
Gini Index of Human Inequality, 1:184
Gordis, Leon, 2:614
ginkgo biloba, 2:833
Gosling, Raymond, 1:456
ginseng, 2:833
Gotting, Alwyn, 4:1459
Glanders, 1:233
Gotting, Fay, 4:1459
Glasgow Coma Scale (GCS), 1:296, 430, 431, 2:777
Gottron’s sign, 3:1150, 1157
glaucoma, 1:269, 2:646–647, 740–741
Gould, Stephen Jay, 1:455
Gliddon, George, 1:455
gout/pseudogout, 1:164, 2:747–750
Global Campaign Against Epilepsy, 2:618
Government Performance and Results Act, 1:50
global climate changes, 1:50
G6PD deficiency, 1:23
global health, history/chronology of, 1:410–412
Graefe, Albrecht Von, 4:1725
Global Health Council (GHC), 2:742–743
gram stain, 1:207
global health ethics, 2:743–744
Grancher, Joseph, 3:1341
Global Initiative for Asthma (GINA), 1:176, 178, 179
Granit, Ragnar Arthur, 2:595
Global Initiative for Obstructive Lung Disease
Grant, Florence, 3:1376
(GOLD), 1:409
grape seed extract, 1:376
Global Polio Eradication Initiative (GPEI), 3:1397
Grassi, Giovanni Batista, 3:1053
Global Tobacco Treaty, 1:412
Graves, Robert, 2:864
Global Youth Tobacco Survey (GYTS), 4:1566
Graves’ disease, 4:1664, 1666
globus sensation, 4:1661
gravitationally-induced loss of consciousness (G-
glomerular disease, 2:744–745, 3:1219
LOC), 1:28
glomerular filtration rate (GFR), 3:972, 1218
greater trochanter bursitis, 4:1602
glomerulonephritis, 3:972
Greece, 2:751–752
I-26
Index
Green, Adele, 3:1283
hair dye, 2:770–771
Green, Elmer, 1:230
Haiti, 2:771–772
Greengard, Paul, 3:1369
Hale, Benjamin, 1:258
Greenland, Sander, 2:614
Hall, G. Stanley, 1:17, 2:736
green tea, 1:376
Hamer, Dean, 2:706
Grenada, 2:752–753
Hamilton, J. G., 2:601, 4:1466
Grenadines and Saint Vincent, 4:1513–1514
Hamlin, Catherine, 2:787
grief, stages of, 1:222–224
Hamon, J., 3:1053
Griesinger, Wilhelm, 3:1435
Han, J. S., 1:13
Grieve, Maud, 2:836
hand acupuncture, 1:13
Griffith, Frederick, 2:722
hand injuries and disorders, 2:772–774
Group A Streptococcus, 1:204
hand reattachments, 1:379–380
group therapy, 3:1449
hand washing, 2:872–873, 3:1423
growth disorders, 2:753–756
Handy, Ronald, 3:1306
growth hormone, 3:1382
Hansen’s Disease, 3:1009–1010, 4:1684
Grubbe, Emil, 1:343
hantavirus, 4:1678
Gruentzig, Andreas, 1:141
haploid, 2:774
guanine (G), 2:713
Hardy, James D., 2:774–775
Guatemala, 2:757–758
Hardy-Weinberg law, 2:775–776
Guillain, Georges, 2:758
Harlem-Brundtland, Gro, 3:1452
Guillain-Barré Syndrome, 2:758–759, 3:1356
Harris, Geoffrey, 3:1224
Guillemin, Roger, 3:1224
Harrison Narcotic Act, 1:421
Guinea, 2:759–760
Hartline, Haldan, 2:595
Guinea-Bissau, 2:760–761
Harvard-Brown Anxiety Disorder Research
Gulf War syndrome, 1:338
Program, 1:152
Gull, William, 1:143
Harvey, William, 1:347, 449
gum disease, 2:761–762
Hashimoto’s disease, 4:1666
Guthrie, Charles, 3:1292
hashish, 3:1068
Guyana, 2:762–763
Havighurst, Robert J., 2:736
gynecologists, 2:763–764, 3:1269
headaches and migraines, 2:781–783
gynecology, 1:88–89, 2:764–767
head and brain injuries, 1:438–439, 2:776–778 head and brain malformations, 2:778–779
H
head and neck cancers (HNCs), 2:779–780
Haemophilus influenzae, 1:149, 158, 184, 186, 203,
head lice, 2:780–781
204, 212, 218, 2:882, 908, 3:1185
Head Start, 1:15
Hahnemann, Samuel, 1:64, 66, 2:856
head trauma, 1:431
hair diseases/hair loss, 1:341–342, 2:769–770
health geography, 3:1081–1083
Index
health insurance, 2:923–925
helper T-cells, 2:879
Health Insurance Portability and Accountability
hemangioblastomas (HGB), 1:291
Act (HIPAA), 2:805–806 health maintenance organizations (HMOs), 2:806–808, 3:1062, 1389, 1410 Health Resource and Services Administration
hemangiomas, 1:254–255 hematologists, 2:822–823 hematology, 2:823–824 hematomyelia, 4:1593
(HRSA), 2:808–809
hemiparesis, 3:1334
healthy immigrant, theory of, 2:853
hemiplegia, 3:1334
Healthy Marriage Initiative, 1:15, 16
hemizygous, 2:825
Healthy People 2010, 1:171, 3:1170
hemochromatosis, 2:825–826
“Healthy People” initiative, 1:30
hemoglobin, 1:133–135
Healy, Bernadine, 4:1757
hemoglobin A1c (HbA1c), 2:504, 505, 510, 513
hearing, 3:1195–1196, 1307, 1308, 1309–1311
hemolytic anemia, 1:133–134
ear disorders in, 2:573–574
hemolytic uremic syndrome (HUS), 1:264
loss of, 2:474–476
hemophilia, 1:252, 265, 2:822, 825
hearing problems, 2:574, 809–810 heart:
I-27
hemorrhagic fevers (HFs), 1:232, 2:826–827, 4:1678
anatomy and structures of, 1:349–350
hemorrhagic stroke, 4:1623
congenital diseases of, 1:439–443
hemorrhoids, 1:131, 2:701, 704, 827–828, 3:1426
coronary disease of, 1:450–452
Hench, P. S., 1:14, 2:601
heart attack, 2:810–811
Henle, J., 1:411
heart bypass surgery, 2:812–813
Henoch-Schonlein purpura, 4:1738
heart disease, 1:101–102, 348, 439–443, 2:813–
Henry VIII, 3:1391
816, 816–818
hepatic vascular disease, 3:1025
heart-lung machine, 2:740
hepatitis, 1:414–415, 2:701–702, 828–829
heart rhythm, irregularities of, 1:159–160
Hepatitis A virus (HAV), 1:23, 27, 29, 197, 394,
heart transplantation, 2:818–819, 3:1292 heart valve diseases, 2:815, 819–820
2:828, 829, 882, 3:1413 Hepatitis B virus (HBV), 1:11, 22, 23, 27, 197, 394,
heat index, 2:820–821
2:828, 829, 882, 908, 3:1022, 1413, 4:1744
Heatley, Norman, 1:146
Hepatitis C virus (HCV), 1:23, 2:828, 829–830,
Hecht-Beals syndrome, 1:214 Helicobacter pylori, 3:1211, 1245, 1352, 4:1613, 1614, 1615, 1616, 1700
3:1022 Hepatitis D virus (HDV), 2:828 Hepatitis E virus (HEV), 2:828
Heller, Theodor, 1:189
hepatocellular carcinoma (HCC), 3:1022–1023
Helmholtz, Hermann von, 2:594
herbalism/herbal medical practices, 2:836–838
helminthology, medical, 3:1083–1084
herbalists, 2:839
helminths (worms), 2:944–945, 3:1335
herbal medicine, 1:66, 375–376, 2:830–834, 3:1114
I-28
Index
herbal remedies, 2:835, 4:1750
Hirschhorn, Norbert, 3:1289
Herbst, Roy, 3:1283
Hirschowitz, Basil I., 1:338, 3:1282
herd immunity, 4:1618
hirsutism, 2:769
hereditary kidney diseases, 3:973
Hispanic American health, 2:853–854
hereditary nonpolyposis colorectal cancer (HNPCC),
Hiss, Alger, 3:1436
1:427
histidine pathways, 1:121
heredity, 2:697, 723–726
histology, 2:854–855
Herelle, Felix d’, 3:1369
histoplasmosis, 2:691
HER2 gene, 1:10
Hitchings, George H., 3:1368
hernias, 2:840, 3:1058
Hitler, Adolf, 3:1390, 4:1628
herniated discs, 1:202, 3:1213, 4:1592
hives, 1:60
heroin abuse, 2:841–843
H5N1, bird flu, 1:242–246
Herpes Resource Center (HRC), 1:115
Hodgkin, Alan Lloyd, 2:594
herpes simplex virus (HSV), 1:220, 2:726, 843–
Hodgkins, Thomas, 2:855
844, 4:1534–1535, 1744
Hodgkin’s lymphoma, 2:855–856, 4:1663
herpes zoster (shingles), 4:1538, 1742
Hollander, Bernard, 3:1377
Herrick, James B., 4:1541–1542
Holley, Robert William, 3:1242
Hertz, S., 2:601
Hollows, Fred, 2:787
heterosexuality, 2:844–845
Holmes, O. W., 1:411
heterozygote, 2:845
holoprosencephaly, 1:297
Heymann, David, 3:1397
Holzheimer, R. G., 2:621
hiatal hernia, 2:702–703
Homeland Security, Department of (DHS), 2:659
high blood pressure/hypertension, 2:846–847,
homeopathy, 1:64, 66, 2:856–857
3:972
homeostasis, 1:263
high-density lipoprotein (HDL), 2:637, 811, 814
homicide, 2:857–858
“high-functioning autism,” 1:187
homocystinuria, 2:756
highly active antiretroviral therapy (HAART), 1:39,
homology, 1:231
40, 46, 3:1142
homosexuality, 2:706, 858–859
high-risk pregnancy, 2:847–849
homozygote, 2:860
Hill, Austin, 2:614
Honduras, 2:860–861
Hilleman, Maurice, 3:1148
Hong Kong flu, 2:917
Himmler, Heinrich, 3:1390
Hoogsteen base pair, 1:213
hinged-type joints, 3:980–983
hookworms, 1:134
hip disorders/injuries, 2:849–852, 3:1004
Hooper, Robert, 3:1147
Hippocrates, 2:836, 3:1083, 1281, 1345, 1369, 1387,
hordeolum, 2:646
4:1631 Hirschfeld, Magnus, 2:706, 859, 3:1011
hormone replacement therapy (HRT), 1:105, 2:626–627, 766, 861–862, 863, 3:1105
Index
hormones, 1:344–345, 2:754–756, 862–864, 912, 3:1336–1337, 1382–1384, 1409 horse flu, 2:917
I-29
humanitarian emergencies, complex (CHE), 1:437–438 human papillomavirus (HPV), 1:22, 43, 45–46, 47,
horticultural therapy, 1:68
81–82, 128, 130, 367, 368, 374–375, 2:679,
Horvitz, H. Robert, 3:1427
765, 883, 4:1481, 1534, 1731, 1753
hospital-acquired pneumonia, 3:1386
human physiology, 3:1381–1382
hot flashes, 3:1103–1104, 1105
human placental stem cells (hPSCs), 4:1608
Hounsfield, Godfrey, 2:864–865, 4:1466
humoral defense, 1:9
House, William F., 3:1309
Hungary, 2:868–869
household poisons, 2:865–866
Hunter, John, 1:337, 2:600
Howard, John, 1:184
Hunter, William, 3:1269
Huggins, Charles B., 4:1724
Huntington, George, 2:870
Hughlings Jackson, John, 2:866–867
Huntington’s disease (HD), 1:254, 2:482, 869–870
human adult stem cells (hASCs), 4:1608, 1609
hurricanes, 1:114, 175, 363, 437, 2:492, 532, 659,
human chorionic gonadotropin (HCG), 4:1653, 1691 human embryonic stem cells (hESCs), 4:1608, 1609– 1611 Human exposure dose/rodent dosage dose (HERP), 1:123
660 Hussein, Saddam, 1:48, 231 Hutchinson, Jonathan, 3:1343 Huxley, Andrew Fielding, 2:594 hydranencephaly, 1:297
human fetal stem cells (hFSCs), 4:1608
hydrocephalus, 2:870–872
human genetics, 1:118–119
hygiene, 2:872–873
Human Genome Organization, The (HUGO),
hyperactivity, 1:384, 2:873–874
2:867–868 Human Genome Project (HGP), 2:708, 714, 717, 936, 3:1180, 1237, 4:1757
hypercalcemia, 1:332 hypercoagulable disorders, 1:263 hypercortisolism, 1:292
human herpesvirus-8 (HHV-8), 1:22, 43, 47
hyperkinetic disorders, 3:1140, 1141
Human Immunodeficiency Virus (HIV), 1:22, 23,
hyperopia (farsightedness), 4:1474
36, 209, 210, 212, 253, 308, 334, 364, 365, 373,
hyperpigmentation, 4:1554–1555
412, 443, 444, 454, 2:598, 726–727, 793, 801,
hypertension/high blood pressure, 2:814, 817,
822, 829, 830, 841, 882, 885, 887, 908, 928–
846–847, 3:972
930, 933–934, 3:995, 1018, 1142, 1162–1163,
hyperthyroidism, 2:755, 4:1664, 1665, 1666–1667
1170–1171, 1424, 1432, 4:1481, 1482, 1504,
hypguesia, 4:1645
1505, 1534, 1535, 1536, 1635, 1653, 1678,
hypnosis, 1:68, 3:1114
1680, 1744
hypobaric environments, 1:28
infections associated with, 1:41–43
hypocalcemia, 1:331
screening of, 1:4
hypoglycemia, 2:874–875
human influenza virus, 1:242
hypogonadism, 2:755
I-30
Index
hypokinetic disorders, 3:1140–1141
inborn maturational blueprint, 1:386
hypopigmentation, 4:1554
inbreeding, 2:893–895
hyposmia, 4:1645
inbreeding, coefficient of, 1:422–423
hypotension/low blood pressure, 3:1030–1031
incidence of disease occurrence, 2:895
hypothermia, 2:875–876
inclusion body myositis, 3:1150
hypothyroidism, 4:1664, 1665, 1666
inclusion body myositis (IBM), 3:1157
hypovolemia, 3:1031
incomplete abortion, 3:1416
hysterectomy, 1:369, 2:766
incontinence, 2:895–897
Hyvärinen, Lea, 4:1576
increased intracranial pressure (ICP), 2:778 India, 2:897–899
I
Indian Health Service (IHS), U.S., 2:899–900,
Iceland, 2:877–878
3:1205
identity, formation of, 1:22
individualized education plan (IEP), 2:500, 3:1002
idiot savant, 1:187
Individuals with Disabilities Education Act (IDEA),
immune globulins, 1:9, 3:1340 immune system, 1:60–63, 192–196, 2:878–882, 881–882, 3:1439 cells in, 1:45 immunity, 1:381
1:183 Indonesia, 2:789, 900–901 indoor air pollution, 2:901–902 industrialization, 3:1393 Industrial Revolution, 1:411
acquired, 1:8–10, 2:919
Infant Formula Act, 3:1168
active, 1:8, 10–11
infants, 4:1625–1627
herd, 4:1618 innate, 2:919 passive, 3:1340–1341 immunizations/vaccinations, 1:26, 393–394, 2:881–883, 904, 908, 3:1181, 1201–1202, 4:1474, 1563
care of, 1:172–173, 175–176, 2:903–904, 3:1271, 4:1479 growth and development of, 2:904–907 health of, 2:907–909 nutrition of, 2:907–909 infections:
immunodeficiency diseases, 2:880
bacterial, 1:203–206
immunoglobulins, 1:60–61
fungal, 2:690–692
immunologists, 2:883–884
infectious arthritis, 1:164–165
immunology, 2:884–885, 4:1658
infectious diseases, 2:909–910, 3:1171–1172,
immunosuppression, 2:885–886
1181–1182, 4:1683
immunotherapy, 1:392–393, 2:886–887
infectious mononucleosis, 4:1741–1742
impetigo, 1:23, 2:887–888
infectious myopathies, 3:1150
impingement syndrome, 4:1540
infectious parotitis (mumps), 3:1148
impotence, 2:888–890
infertility, 1:99, 2:911–913, 4:1480
inborn errors of metabolism, 2:717
infibulation, 2:662
Index
inflammatory bowel disease (IBD), 1:131, 427, 2:701, 913–915
International AIDS Vaccine Initiative (IAVI), 2:928–929
inflammatory myopathies, 3:1149–1150
International Atomic Energy, 4:1510
influenza, 1:11, 103, 2:882, 915–917, 3:1202,
International Atomic Energy Agency (IAEA),
4:1484, 1742–1743 informed consent, 2:479 inhalants, 2:918 inhalation burn injuries, 1:323 inheritance, 2:860 iniencephaly, 1:297 innate immunity, 2:919 inner ear compartment, 2:574, 576 inoculation, 1:26 inpatient medical treatment, 2:919–920 insecticides, 3:1139, 1358 insecticide-treated nets (ITNs), 3:1051, 4:1474 insects:
I-31
2:517 International Center for Equal Healthcare Access (ICEHA), 2:929–930 International Classification of Diseases (ICD), 1:250, 2:930–931, 3:1433, 1438 International Classification of Mental and Behavioral Disorders, 1:143, 187 International Clinical Epidemiology Network (INCLEN), 2:931–932 International Committee of the Red Cross (ICRC), 2:932–933 International Council of AIDS Service Organizations (ICASO), 2:933–934
as disease vectors, 3:1080–1081
International Diabetes Foundation (IDF), 3:1264
study of, 3:1078–1081
International Epidemiological Association (IEA),
in situ, 2:890 insomnia, 4:1555–1556 Institute for Children’s Environmental Health (ICEH), 2:920–921 Institute of Medicine (IOM), 2:921–922 Institutional Review Board (IRB), 2:892, 922–923 Instrumental Activities of Daily Living (IADLs), 1:12, 69 insulin, 1:98–99, 2:501, 503, 505, 507, 508, 874 insurance, 2:923–925
2:934–935 International Federation of Red Cross and Red Crescent Societies (IFRC), 2:935–936 International Genetic Epidemiology Society (IGES), 2:936 International Health Ministries Office (IHMO), 2:937 International Labor Organization (ILO), 3:1244, 1272, 1273, 1274 International Red Cross and Red Crescent
intelligence testing, 2:519–520
Movement (RCRC), 1:113–115, 2:937–939,
intensity of impression, 3:1100
3:1096
internal head injuries, 2:776–777 internal medicine, 2:925–927 International Agency for Research on Cancer (IARC), 2:927–928 International Agency for the Prevention of Blindness (IAPB), 1:270
International Society for Environmental Epidemiology (ISEE), 2:939–940 International Society for Pharmacoepidemiology (ISPE), 2:940–941 International Society of Bone and Soft Tissue Pathology, 1:276
I-32
Index
International Society of Geographical and Epidemiological Ophthalmology (ISGEO),
itching, 1:131 Ivory Coast, 1:453–454
2:941–942 International Study of Asthma and Allergies in Childhood (ISAAC), 1:63 International Women’s Health Coalition (IWHC), 2:942–943
J Jacobson, Jules, 3:1125 Jamaica, 2:957–958 Janet, Pierre, 3:1230
internists, 2:925–927, 943–944
Jansson, C., 2:622
interstitial cystitis, 1:262
Japan, 2:787–788, 958–960
interstitial lung disease, 3:1455–1456
Jarvick, Robert, 1:348
intestinal parasites, 2:944–946
Jarvis, S., 4:1551
intracranial injuries, 2:777
Jaspers, Karl, 3:1435
intracranial neoplasm, 1:294
jaundice, 3:1328
intracranial pressure, 1:289
Jenner, Edward, 1:26, 411, 2:881, 883, 884, 3:1369,
intraocular lens (IOL), 1:357
1451, 4:1563
intrauterine devices (IUDs), 1:248–249
Jensen, Bernard, 2:950
in vitro, 2:890–892
Jensen, Elwood, 2:601, 3:1282
in vitro fertilization (IVF), 1:315, 2:891, 913, 4:1608
Jersey finger, 4:1601–1602
in vivo, 2:892–893
Jesty, Benjamin, 3:1451
iodine deficiency disorders, 4:1667
Jesus, Vicente de, 3:1376
ionizing radiation, 4:1463–1464
Jinnah, Mohammed Ali, 3:1322
ipecac, syrup of, 2:866
Johannsen, Wilhelm Ludvig, 2:729, 3:1373
Iran, 2:946–947
John A. Hartford Foundation, 1:100
Iraq, 2:947–948
John of Arderne, 3:1282
Ireland, 2:948–949, 4:1703–1707
John Paul II, 3:1138
iridology, 2:950
Johnson, Lyndon B., 1:363, 2:904, 3:1076, 1091, 1188,
iron, 4:1749 irritable bowel syndrome (IBS), 2:700–701, 950–
1242, 4:1525 Johnson-Sirleaf, Ellen, 3:1017
952
Joint FAO/WHO Expert Committee on Food
ischemia, 4:1593
Additives (JECFA), 2:960–961
ischemic heart disease (IHD), 1:348
joints, tumors of, 1:391
ischemic necrosis, 3:1301–1302
Jones, Ian, 1:243, 244
ischemic stroke, 4:1623
Jong-Wook, Lee, 3:1452
isografts, 1:63
Jordan, 2:962–963
Israel, 2:952–953
Juarez, Benito, 3:1123
Italy, 2:953–954
Judkins, M. P., 1:140
Itard, Jean Marc Gaspard, 1:190
jurisprudence, medical, 3:1085–1086
Index
juvenile dermatomyositis, 3:1150 juvenile rheumatoid arthritis (JRA), 2:964–965 Juvenile Type I Diabetes, 2:507–508
I-33
kidney diseases, 2:513–514, 744–745, 3:971–974, 1186–1187, 1217, 1398–1399 kidney failure and dialysis, 2:521, 3:975–976 kidney stones, 3:973, 976–977
K
kidney transplantation, 3:977–978
Kala-Azar, 3:1009
Kim, Jim, 3:1452
Kallmann syndrome, 4:1646
King, John, 2:837
Kandel, Eric, 2:601, 3:1369
Kinsey, Alfred, 1:257, 2:859
Kane, Carol, 2:661
Kiribati, 3:978
Kanner, Leo, 1:188, 190
Kirk, Samuel, 3:999
Kant, Immanuel, 2:744
Kirklin, John W., 3:979
Kaplan, Henry S., 3:1282
Kitasato, Shibasaburo, 2:883
Kaposi’s sarcoma (KS), 1:36, 47, 4:1580
Klein, Fred, 1:257
Karen McNulty Scholarship Fund, 1:26
Kleinbaum, David, 2:614
Katz, Bernard, 1:197, 3:1368
Klinefelter, Harry, 3:979
Katz ADL Scale, 1:12
Klinefelter’s syndrome, 1:252, 2:756, 3:979–980
Kawasaki disease, 4:1738
knees, injuries/disorders of, 3:980–983, 1004,
Kayser-Fleischer rings, 4:1762
1006, 4:1602–1603
Kazakhstan, 3:967–968
knockouts, genetic, 3:983–984
Keel, Pamela, 1:320
Know What to Do for Life Campaign, 1:31
Kelly, Ned, 3:1377
Knudson, Alfred G., 2:735
Kelman, Charles D., 3:968
Koch, Christof, 1:456
Kendall, E. C., 1:14, 2:601
Koch, Robert, 1:144, 207, 215, 411, 2:883, 884,
Kendrick, Pearl, 4:1760
3:1053, 4:1685
Kennedy, John F., 1:15, 3:1185
Kohlberg, Lawrence, 1:19, 21, 3:1442
Kenya, 3:969–970
Kokot, Franciszek, 2:601
keratosis pilaris, 2:769
Kolzig, Olaf, 1:192
Kerr, John F. R., 3:1427
Koop, C. Everett, 3:1449
Kertbeny, Karl-Maria, 2:858
Korea, North, 3:984–985
ketamine, 2:473
Korea, South, 3:985–986
Kevorkian, Jack, 4:1628
koro, 1:154
Khalifa, Sheikh, 4:1459
Korsakoff amnestic syndrome, 1:57
Khan, Imran, 3:1323
Kouchner, Bernard, 3:1095, 1096
Khmer Rouge, 1:333
Krabbe’s disease, 3:1118–1119
Khoraha, Har Gobind, 3:1242
Kraepelin, Emil, 3:1435, 1436
Kick the Habit, 1:103
Krieger, Dolores, 1:67–68
kidney cancer, 3:970–971, 973–974
Krueger, Diane, 3:1306
I-34
Index
Kübler-Ross, Elisabeth, 1:222, 3:986–987
LASIK (laser-assisted in-situ keratomileusis), 3:1285
Kuhl, David E., 3:1282
Lasker, Mary, 1:84
kuru, 1:288
Lassa fever, 1:354
Kuwait, 3:987–988
lateral epicondylitis, 4:1601, 1769
kwashiorkor, 3:988
Latvia, 3:995–996
Kyrgyzstan, 3:988–989
Lauterbur, Paul, 3:996–997, 1065, 1282 Laval, Pierre, 3:1391, 4:1628
L
Laveran, Charles Louis Alphonse, 3:1053
Labhart, Alexis, 3:1408
Lavoisier, Antoine-Laurent, 1:228
laboratory tests, 3:992–993
Lawrence, D. H., 2:873
Lacassagne, Antoine, 2:600
laxatives, 1:447
lactose intolerance, 3:993–994
“lazy eye,” 1:74
Laënnec, René, 1:348, 408, 414
lead poisoning, 3:997–998, 1390
Lagergren, J., 2:622
lean body mass, 3:998–999
Lahlous, Leila, 3:1136
learning, 1:386
Laing, R. D., 3:1436
Learning and Developmental Disability Initiative
Lamarck, Jean-Baptiste, 2:472, 723
(LDDI), 2:921
Lambl, V., 2:739
learning disabilities, 3:999–1002
La Montagne, John, 3:991–992
learning disorders, 3:999–1002
Landau-Kleffner Syndrome (LKS), 1:155
learning problems, 3:1349
landmines, 1:29, 166
Leaver, Christopher J., 3:1427
Landolt, Edmund, 4:1576
Lebanon, 3:1002–1003
Landouzy-Dejerine Syndrome, 3:1152
Leburton’s Law, 1:217
land pollution, 3:1394
Lederberg, Joshua, 3:1003–1004
Landry, Jean, 2:758
Ledermann, Barbara, 4:1497
Landsteiner, Karl, 1:270, 2:883
leeches, 1:240
language-based learning disabilities, 4:1589
Leeuwenhoek, Anton van, 1:207, 247, 3:1450
language development, 1:388
legal medicine, 3:1085–1086
Laos, 3:994–995
Legg-Calvé-Perthes disease, 3:1004, 1302
Lapouge, Georges Vacher de, 1:455
leg injuries/disorders, 3:1004–1006
Laron, Zvi, 2:601
Legionella pneumophilia, 3:1007
laryngitis, 4:1751
Legionnaire’s disease, 3:1006–1008, 4:1678
larynx cancers, 2:780
Leighton, Margaret, 3:1147
larynx (voice box), 4:1661, 1751–1752
leiomyoma, 4:1728
Lasègue, Ernest-Charles, 1:143
Leishmania brazilensis, 3:1009
LASEK (laser subepithelial keratectomy), 3:1285
Leishmaniasis, 3:1009, 1138, 1335, 4:1553, 1684
Lashley, Karl, 2:601
Lejeune, Jerome, 1:252
Index
Leonhard, Karl, 3:1435
Listeria monocytogenes, 2:674
leprosy, 1:29, 269, 3:1009–1010, 4:1684
lithium, 3:1064, 1113
leptospirosis, 4:1513, 1678
Lithuania, 3:1020–1021
lesbianism, 3:1010–1012
Little, William, 1:365
Lesotho, 3:1012–1013
Littlejohn, J. Martin, 3:1303
leukemias, 1:281, 337, 390, 2:822, 824, 3:1013–
liver cancer, 1:57, 391, 3:1022–1023
1015
I-35
liver diseases, 1:414–415, 3:1023–1026
leukodermia, 4:1551
liver spots, 4:1555
leukodystrophies, 3:1016
liver transplantation, 3:1026–1027
LeVay, Simon, 2:706
Livingstone, David, 2:785
Levy, Ronald, 3:1283
Lloyd, John Uri, 2:837
Lewi, M. J., 3:1387
localized scleroderm, 4:1527
Lewis, Edward B., 3:1017
locus, genetic, 3:1027–1028
Lewis, F. J., 4:1736
Lofting, Hugh, 2:785
Lewis, John, 1:348
longitudinal studies, 3:1028–1029, 1444
Lewy body disease, 2:484, 3:1141
Lou Gehrig’s disease, 1:311, 2:482, 3:1029–1030,
Liberia, 3:1017–1018
1153, 1187, 1227, 1233
Libya, 3:1018–1019
Louis XVI, 2:856
lice, 2:780–781, 4:1535
Lovell, Joseph, 3:1199
Lidwina of Schiedam, 3:1147
Lovelock, James, 1:461
Liechtenstein, 3:1019–1020
Lovie, Jan, 4:1576
Lightman, Stafford, 2:601
low birth weight (LBW) infants, 3:1215–1216,
Lillard, Harvey, 1:403–404
4:1479
Lillehei, C. Walton, 4:1736
low blood pressure/hypotension, 3:1030–1031
limb-girdle muscular dystrophy (LGMD), 3:1152
low-density lipoprotein (LDL), 1:150, 316, 2:637,
Lincoln, Abraham, 2:672
811, 814, 4:1676, 1720
Lincoln, Edith, 1:102
Lowei, Otto, 3:1368
line source air pollution, 1:48
lower esophageal sphincter (LES), 1:5, 2:702, 703
Ling, Victor, 3:1283
lower motor neurons (LMNs), 3:1029
Linnaeus, 3:1378
lower respiratory infections (LRIs), 1:203–204
Linne, Carl von, 2:836
low vision, 1:269, 3:1032–1033
lipodystrophy, 2:755
Lubic, Ruth, 3:1414
lipopolysaccharide (LPS), 2:919
Ludwig, Carl, 2:594
Lisker-Melman, M., 3:1025
lung cancer, 1:337, 3:1033–1036, 4:1486–1487
lissencephaly, 1:297
lung diseases, 1:102–103, 408–410, 2:595–597,
Lister, Charles, 1:332 Lister, J., 1:270, 411, 2:614, 4:1632
3:1455–1458 lung transplantation, 1:467, 3:1036–1037
I-36
Index
lupus (SLE), 3:1037–1039, 1183
Magendie, François, 1:219
Luria, Salvador, 4:1756
maggots, 1:240
Lust, Benedict, 3:1208
magnetic resonance cholangiopancreatography
luteinizing hormone (LH), 3:1107 Luxembourg, 3:1039–1040 lycopene, 1:376
(MRCP), 1:227 magnetic resonance imaging (MRI), 1:72, 200, 2:516, 3:1065
Lydon, Nicholas, 3:1283
magnetic therapy, 1:66
Lyell, Charles, 2:472
Mahalanabis, Dilip, 3:1289
Lyme borreliosis, 3:1040–1042
Ma Huang, 2:832
Lyme disease, 2:583, 3:1040–1042
maintenance medication, 3:1049–1050
lymphadenitis, 3:1043
major depression, 2:492, 494, 3:1063
lymphadenopathy, 3:1213
malabsorption, 2:530, 702, 4:1496
lymphangioleiomyomatosis (LAM), 3:1044
malaria, 1:29, 218, 334, 411, 444, 2:598, 613, 720,
lymphangioma, 3:1043–1044
909, 945, 3:969, 995, 1050–1052, 1138, 1239,
lymphangiosarcoma, 3:1043
1349, 1357, 1377, 1413, 1453, 4:1474, 1584,
lymphatic diseases, 3:1042–1045
1625, 1634, 1677, 1678, 1679–1680, 1683,
lymphatic filariasis, 4:1684
1684, 1690, 1776
lymphatic system, 3:1042
malariologists, 3:1052–1053
lymphedema, 2:665, 3:1042–1043
malariology, 3:1053–1054
lymph nodes, 1:345–346, 359, 429
Malawi, 3:1054–1055
lymphocytes, 2:879
Malaysia, 3:1055–1056
lymphoid organs, 2:878
Maldives, 3:1056–1057
lymphomas, 1:337, 390, 2:824, 855–856, 3:1044
male genital disorders, 3:1057–1058
Lynch, Eliza, 2:786
malformations: head and brain, 2:778–779
M
vascular, 1:255
MacArthur-Bates Communicative Development Inventory, 1:191
Mali, 3:1059 malignant mesothelioma, 3:1059–1061
MacDonald, Russell, 3:1053
Mall, Franklin P., 4:1508
Macedonia (FYROM), 3:1047–1048
mallet finger, 4:1601
MacLeod, Colin, 1:196, 2:722
malnourishment, 3:1256–1259
MacMahon, Brian, 4:1612
malnutrition, 1:211, 226, 3:988, 1066–1067, 1257,
macrocytic anemia, 1:133
4:1496, 1505
macrophages, 2:919
malpractice reforms, 1:104
Madagascar, 3:1048–1049
Malta, 3:1061–1062
mad cow disease, 1:287–289
Mam, Sonn, 1:333
Madsen, Pamela, 1:99
mammograms, 1:302, 305
Index
I-37
managed care, 3:1062
Maudsley method, 1:144
Manhattan Project, 2:489
Maunoir, Theodore, 2:932
manic-depressive illness, 1:241, 242, 3:1063–1065
Mauritania, 3:1071–1072
Mannick, J. A., 2:621
Mauritius, 3:1072–1073
Mansfield, Peter, 3:996, 1065–1066
Maus, L. M., 3:1376
Manson, Patrick, 3:1053
maxillofacial injuries, 2:649–652
manual vacuum aspiration (MVA), 1:4
Mayo, Charles, 4:1613
marasmus, 3:1066–1067
Mayo Clinic, 1:258
Marburg, Otto, 3:1147
McCarthy, Jenny, 1:192
Marburg virus, 1:232, 236
McCarty, Maclyn, 1:196, 2:722
March of Dimes Foundation, 1:251
McClain, H. M., 1:48
Marcia, James, 1:22
McClintock, Barbara, 3:1073–1074
Marcos, Ferdinand, 4:1723
McKeown, Thomas, 3:1451
Marcos, Pacifico Edralin, 3:1377
McKinley, John, 3:1104
Marfan, Antoine, 3:1067
McKinley, Sonja, 3:1104
Marfan syndrome, 1:136, 137, 2:756, 3:1067–1068
MDMA, 1:123, 124
Margulis, Lynn, 3:1427
Mead, Margaret, 1:17, 3:1074–1075, 1103, 1104
Marie, Pierre, 3:1230
Meager, Leonard, 1:68
marijuana, use/abuse of, 1:20, 3:1068–1070
measles, 1:11, 29, 2:598, 882, 908, 3:1075–1076
marital rape, 2:473
mechanistic toxicology, 4:1674
Mark A. Jerstad Information Resource Center, 1:101
Mechnikov, Ilya, 2:588, 3:1341
Mark Antony, 4:1628
Meckel, H., 3:1053
Marshall Islands, 3:1070–1071
meconium ileus, 1:465
Martin, Tisha Campbell, 1:192
medial collateral ligament (MCL) injury, 3:982
Marx, Gertie, 3:1071
medial epicondylitis, 4:1601
Massa, Niccolo, 3:1430
Medicaid, 1:17, 32, 363, 2:802, 805, 3:1076–1077
massage therapies, 1:66–67
Medical College Admissions Test (MCAT), 3:1078
mastectomy, 1:303, 306, 308
medical devices, 3:1314
maternal healthcare, 1:172–173, 175–176, 3:1269–
medical entomology, 3:1078–1081
1272
MedicAlert, 3:1090
Maternal Mortality Ratio (MMR), 3:1269
medical geography, 3:1081–1083
mathematics disorders, 3:1001
medical helminthology, 3:1083–1084
Mathey, Heinrich, 1:404
medical jurisprudence, 3:1085–1086
Mattioli, Pietro, 2:836
medical licensing, 4:1710
maturation, 1:386
medical physics, 3:1086–1087
maturity-onset diabetes of the young (MODY),
Medical Research Council (MRC), 3:1087–1088
2:503
medical tests, 2:518
I-38
Index
medical tibial stress syndrome (MTSS), 4:1603 medical tourism, 2:899, 3:1088–1090 Medicare, 1:17, 184, 363, 2:802, 805, 3:1091–1095, 1096–1097
meningitis, 1:204, 221, 294, 321, 370, 3:1101–1102, 1213 meningococcus, 1:27, 2:883 meniscus injury, 3:982
medication abortion, 1:2, 3
menopause, 1:301, 2:861, 862, 3:1102–1106
medications, 3:1049–1050, 1420–1422, 4:1710–
menstruation, 3:1106–1109
1711, 1736 adverse drug reactions (ADRs), 3:1364
mental health, 1:20–21, 394–396, 3:1109–1116, 1188–1189, 1200–1201, 4:1567–1568
categories of, 3:1370
mental health counselors, 3:1112
over-the-counter (OTC), 3:1313–1315, 1361
mental illness, 1:241–242, 3:1109–1116, 4:1628
placebos and, 3:1384–1385
mental retardation, 1:252
side effects of, 3:1364
mercury, 3:1116–1117
medicine, conventional, 1:448–449
Mering, Joseph Freiherr von, 3:1368
medicine, evidence-based (EBM), 2:632–633
Mesmer, Franz Anton, 3:1435
Médicins Sans Frontières (MSF), 1:333, 3:1095–
mesothelioma, malignant, 3:1059–1061
1096
messenger ribonucleic acid (mRNA), 2:711, 3:1248
medico-legal medicine, 3:1085–1086
meta-analysis, 3:1117–1118
Medigap policy, 3:1096–1097
metabolic diseases/disorders, 1:293, 2:499,
MEDLINE, 3:1097
3:1118–1119
medullary thyroid cancer, 4:1664
metabolic liver disease, 3:1025
megalencephaly, 1:297
metabolic myopathies, 3:1150
megaloblastic anemia, 2:669
metabolism, 1:228
Mehl-Madrona, Lewis, 3:1206
Metchnikoff, Elie, 2:736, 884
Meister, Joseph, 4:1461
methadone, 2:842
Melanchthon, Philipp, 3:1440
methamphetamine abuse, 1:123, 124, 3:1119–
melanoma, 1:338, 4:1549, 1550–1551 melasma, 4:1554–1555 Mellanby, Edward, 3:1087
1122, 1416 methicillin-resistant Staphylococcus aureus (MRSA), 4:1607
Mellanby, Scott, 1:192
methylation, 3:1122–1123
memory, 3:1097–1100
“me-too drug,” 3:1074
memory cells, 1:10, 11, 2:881
Mexico, 3:1123–1124
menarche, 1:17, 300–301, 3:1106, 4:1728
Meyer, Adolf, 3:1435
Mendel, Gregor Johann, 2:723
Meyeus, Philippus, 2:950
Mendelian inheritance, 2:616, 723, 724, 725, 727,
microbial physiology, 3:1380
4:1583
microbiology, 1:206
Ménière’s disease, 3:1100–1101
microcephaly, 1:297
meningiomas, 1:291
Micronesia, Federated States of, 3:1124–1125
Index
micronutrients, 4:1746–1749
Monaco, 3:1133
microscopic polyangitis, 4:1738
Mona Lisa syndrome, 1:219
microsurgery, 1:379–380, 3:1125–1126
Monckeberg medial calcific sclerosis, 1:160, 161
middle ear compartment, 2:573–574, 575
Mongolia, 3:1133–1134
midwives, 1:87–88, 3:1126–1127
Moniz, Egas, 3:1235
migraines and headaches, 2:781–783
monoamine oxidase inhibitors (MAOIs), 3:1446
milestones, 1:386
monoclonal gammopathy of undetermined
Milgram, Stanley, 3:1444 Millennium Development Goals (MDGs), 3:1453, 4:1479, 1481
signification (MGUS), 3:1145 mononucleosis, infectious, 4:1741–1742 monozygotic twins (MZ), 3:1134–1135
Miller, Jacques, 4:1662–1663
Montagnier, Luc, 1:36
Miller, Neal, 1:229–230
Montenegro, 4:1531–1532
minerals and vitamins, 4:1746–1749
mood disorders, 2:492–496
miners/mining, 3:1127–1128, 1274, 1275
moral development, 1:21
Mine Safety and Health Administration (MSHA),
moral hazard, 2:923
3:1127–1128 Mini-Mental State Examination, 1:71
I-39
Morbidity and Mortality Weekly Report (MMWR), 1:36
minor depressive episode, 2:494
Morgan, John, 1:14
miscarriage, 1:1
Morita, Shoma, 1:154
Mishima, Yukio, 4:1628
morning sickness, 3:1412
mismatch repair, 3:1128–1129
Morocco, 3:1136
missed abortion, 3:1416
mortality, 3:1136–1137
missense mutation, 3:1129
Morton, Samuel George, 1:455
mistletoe, 3:1164–1165
Moscati, St. Joseph, 3:1137–1138
mitochondrial decay, 1:123
mosquitoes/mosquito-borne diseases, 2:485–
mitochondrial diseases, 1:293
486, 665, 909, 3:1050–1052, 1138–1139,
mitochondrial myopathies, 3:1150
4:1757
mitral valve disease, 2:815, 820
motor development, 1:386–387
mixed hearing loss, 2:474
motor neuron disorders, 2:718
mixed incontinence, 2:896
mourning, 1:222, 223
mnemonic devices, 3:1100
mouth disorders, 3:1139–1140
Moerman, Daniel, 2:836
mouth guards, 2:650
Moldova, 3:1129–1130
movement disorders, 2:717–718, 3:1140–1143
molds, 2:690–692, 3:1131–1132
Moynier, Gustave, 2:932
molecular cloning, 2:729
Mozambique, 3:1143–1144
moles, 4:1555
mucosa-associated lymphoid tissue (MALT),
Momen, Hakim, 2:946
4:1614
I-40
Index
Mugabe, Robert, 4:1776
myeloproliferative disorders, 2:824
Muhler, Joseph, 2:668
Mylrea, Stanley, 3:987
Mullen Scales of Early Learning, 1:191
myocardial infarction (MI), 1:451, 2:810–811,
Müller, Paul, 3:1053
816
Mullerian Agenesis, 1:252
myoclonus, 3:1141
multidrug-resistant tuberculosis (MDR-TB), 1:206,
myopia, 4:1474
4:1684 Multimodal Treatment Study of Children with ADHA, 1:183 Multiple Chemical Sensitivity (MCS), 3:1144–
myositic ossificans, 3:1150 myositis, 3:1157–1158 myotonic muscular dystrophy (MMD), 3:1152 myxomatosis, 1:229
1145 multiple myeloma, 1:276, 3:1145–1146
N
multiple sclerosis (MS), 3:1146–1147, 4:1593
Nägeli, Karl Willem von, 1:406
mumps, 1:11, 26, 2:882, 908, 3:1148, 1202
Nalin, David R., 3:1289
mumps, measles, and rubella (MMR), 3:1076, 1148
Namibia, 3:1159–1160
Munchausen-by-proxy, 1:383
Napoleon I, 2:827
Munthe, Axel M. F., 3:1230
narcolepsy, 4:1557
Murray, Joseph, 2:883, 886
Narraro, Constantino, 3:1138
muscle disorders, 3:1148–1150, 1157–1158
nasal cavity cancer, 2:779, 3:1252
muscle injuries, 3:1149
nasal polyps, 3:1252
muscular dystrophy, 1:254, 2:718, 3:1151–1154,
Nascher, Ignatz, 1:100, 2:736
1232 Muslim populations, 1:158 mutagens, chemical, 1:121–122 mutations, 3:1129 nonsense, 3:1248–1249 somatic, 4:1583–1584 Myanmar (Burma), 3:1154–1155 myasthenia gravis (MG), 3:1149, 1153, 1155–1157, 1232–1233 mycobacterium avium complex (MAC), 1:45 Mycobacterium leprae, 1:269, 3:1009–1010 Mycobacterium tuberculosis, 1:42, 205, 4:1486 mycoses, 2:690–692 mycotoxins, 3:1131–1132 myelodysplastic syndrome (MDS), 1:281 myelomas, 2:824
National Aeronautics and Space Administration (NASA), 3:1003 National Asian Women’s Health Organization (NAWHO), 3:1160–1161 National Association for Sport and Physical Education (NASPE), 2:634 National Association of Health Data Organizations (NAHDO), 3:1161–1162 National Association of People with AIDS (NAPWA), 3:1162–1163 National Biodefense Analysis and Countermeasures Center (NBACC), 1:229 National Breast Cancer Coalition (NBCC), 3:1163–1164 National Cancer Institute (NCI), 1:73, 258, 278, 314, 3:1164–1165, 4:1634, 1635
Index
National Center for Assisted Living (NCAL), 1:101 National Center for Chronic Disease Prevention and Health Promotion (NCCDPHP), 3:1165–1166 National Center for Complementary and Alternative Medicine (NCCAM), 1:65, 3:1166–1167 National Center for Environmental Health (NCEH), 3:1167–1168 National Center for Health Marketing (NCHM), 3:1168–1169 National Center for Health Statistics (NCHS), 3:1169–1170 National Center for HIV, STD, and TB Prevention (NCHSTP), 3:1170–1171 National Center for Infectious Diseases (NCID), 3:1171–1172 National Center for Injury Prevention and Control (NCIPC), 3:1172–1173 National Center for Public Health Informatics (NCPHI), 3:1173–1174 National Center on Birth Defects and Developmental Disabilities (NCBDDD), 3:1174–1175 National Cholesterol Education Program (NCEP), 1:451, 3:1175–1176 National Coalition for Cancer Survivorship (NCCS), 3:1176 National Commission for Health Education Credentialing (NCHEC), 1:82 National Environmental Health Association (NEHA), 3:1177 National Epidemiologic Survey on Alcohol and Related Conditions (NESARC), 1:52 National Eye Institute (NEI), 3:1177–1179 National Family Caregiver Support Program (NFCSP), 1:16–17
I-41
National Health and Nutrition Examination Survey (NHANES), 2:515 National Heart, Lung and Blood Institute (NHLBI), 3:1179–1180 National HPV and Cervical Cancer Prevention Resource Center, 1:115 National Human Genome Research Institute (NHGRI), 3:1180 National Immunization Program (NIP), 3:1181 National Institute of Allergy and Infectious Diseases (NIAID), 2:611, 3:1181–1182, 4:1757–1758 National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS), 3:1182–1183 National Institute of Biomedical Imaging and Bioengineering (NIBIB), 3:1184 National Institute of Child Health and Human Development (NICHD), 3:1185–1186 National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), 3:1186– 1187 National Institute of Environmental Health Sciences (NIEHS), 3:1187–1188 National Institute of Mental Health (NIMH), 3:1188–1189 National Institute of Neurological Disorders and Stroke (NINDS), 1:73, 289, 292, 366, 2:758, 3:1189–1190, 1356, 4:1595 National Institute of Nursing Research (NINR), 3:1190–1191 National Institute of Occupational Safety and Health (NIOSH), 3:1191–1192 National Institute of Standards and Technology (NIST), 1:96 National Institute on Aging (NIA), 1:72, 73, 3:1192–1194
I-42
Index
National Institute on Alcohol Abuse and Alcoholism (NIAAA), 1:52, 3:1194–1195 National Institute on Deafness and Other
naturopathic medicine/naturopathy, 1:67, 3:1208–1209 Nauru, 3:1210
Communication Disorders (NIDCD),
nausea and vomiting, 2:529, 3:1210–1212
3:1195–1196
neck and head cancer, 2:779–780
National Institute on Drug Abuse (NIDA), 3:1196–1197
neck disorders and injuries, 3:1212–1214 neglect, 1:383
National Institute on Mental Health (NIMH), 1:73
Neimann-Pick disease, 4:1488
National Institute on Nursing Research (NINR), 1:73
Neisseria gonorrhoeae, 2:746
National Institutes of Health (NIH), U.S., 1:32, 33,
Neisseria meningitidis, 1:204
65, 72, 107, 191, 3:1197–1199 National Library of Medicine (NLM), 3:1199– 1200 National Mental Health Association (NMHA), 3:1200–1201 National Network for Immunization Information (NNii), 3:1201–1202
nematodes, 3:1083–1084 neonatal intensive care units (NICU), 3:1214, 1418 neonatal nurses, 1:175–176 neonatologists, 3:1214 neonatology, 3:1214–1216 Nepal, 3:1216–1217 nephritis, 3:973
National Network on Aging, 1:17
nephrogenic diabetes insipidus (NDI), 2:501
National Organ Procurement and Transplantation
nephrologists, 3:1217–1218
Network (OPTN), 3:1292
nephrology, 3:1218–1219
National Organ Transplant Act (NOTA), 4:1709
nerve agents, 1:233
National Osteoporosis Foundation, 1:283
nerve disorders, peripheral, 3:1354–1356
National Program of Cancer Registries (NPCR),
nervous system:
3:1202–1203
degenerative nerve disease in, 2:481–483
National Research Priority, 1:185
diabetic neuropathy of, 2:514–515
National Survey on Drug Use and Health (NSDUH),
disabilities, 2:498–499
3:1069, 1420 National Tuberculosis and Respiratory Disease Association, 1:103 National Women’s Health Organization (NWHO), 3:1203–1204
Netherlands, 3:1219–1221 Neugarten, Bernice, 3:1105 neuralgia, 2:649–650 neural tube defects (NTDs), 1:251, 252, 2:669, 3:1221–1222
National Women’s Law Center, 1:105
neuroblastoma, 1:391, 3:1222–1224
Native American health, 2:899–900, 3:1204–
neurodegenerative diseases/disorders, 1:293, 3:1190,
1207
1228–1229
natural family planning (NFP), 1:249
neurodermatitis, 2:498
natural killer cells, 1:9
neuroendocrine tumors, 1:344
natural selection, 2:472, 730
neuroendocrinology, 3:1224–1225
Index
neurofibromatosis, 2:756, 3:1225–1226
Nitze, Max, 4:1724
neurogenic bladder, 1:261–262
Niven, David, 3:1147
neurogenic fainting, 2:653–654
Nixon, Richard M., 1:238, 3:1282, 4:1525
neurogenic thoracic outlet syndrome, 4:1659
NMDA receptors, 1:56
neurological diseases/disorders, 3:1189–1190,
nociceptive pain, 3:1320–1321
1226–1229
I-43
nocturnal incontinence, 2:897
neurologists, 3:1230
noise, 3:1243–1244
neurology, 2:866, 3:1230–1232, 4:1468
Nol, Lon, 1:333
neuromuscular disorders, 3:1232–1233
nonalcoholic fatty liver disease (NAFLD), 3:1025
neuropathic pain, 3:1320–1321
non-articular injuries, 2:852
neuropathies, 3:1232, 1320–1321
non-communicable disease (NCD), 2:889–890
neuropsychiatry, 3:1437
nongovernmental organizations (NGOs), 1:15, 185,
neuropsychological testing, 2:520 neuropsychologists, 3:1233–1234 neuroradiologists, 3:1234 neuroradiology, 3:1234–1235 neuroscience, 3:1236–1237
412 non-Hodgkin lymphoma (NHL), 1:390–391, 3:1244–1248, 4:1663 nonnucleoside reverse transcriptase inhibitor (NNRTI), 1:46
neuroscientists, 3:1237–1238
nonsense mutation, 3:1248–1249
neutrophils, 2:919
non-specific secondary response of immune system,
Nevis and Saint Kitts, 4:1511–1512 nevus, 4:1555 newborns, care of, 2:903–904, 4:1479
2:879 nonsteroidal anti-inflammatory drugs (NSAIDs), 1:72, 323, 325, 353, 2:750, 4:1495
New Zealand, 2:790–791, 3:1238–1239
nontropical sprue, 1:357
Ngor, Haing S., 1:333
normal flora, 4:1732
niacin (B3), 4:1748
North American Association for the Study of
Nicholas II, 3:1301
North Atlantic Treaty Organization (NATO), 1:231
nicotine, 4:1566–1569, 4:1570, 1573
Norway, 3:1250–1251
Niemann-Pick disease, 3:1119
nosebleeds, 3:1252
Niger, 3:1240–1241
nose disorders, 3:1251–1252
Nigeria, 3:1241–1242
Notestien, F. W., 2:484
night blindness, 4:1746
Not on Tobacco (NOT), 1:103
Nightingale, Florence, 2:938, 4:1689
Nott, Josiah C., 1:455
night sweats, 3:1104
Nourbakhsji, Hoseini, 2:946
9/11, 1:104, 114
nuclear magnetic resonance (NMR), 3:996
Nirenberg, Marshall W., 3:1242
nuclear medicine, 3:1253–1254
Nitschke, Philip, 4:1628
nuclear radiation, 4:1612
Nicaragua, 3:1239–1240
Obesity (NAASO), 3:1249–1250
I-44
Index
Nuclear Regulatory Commission, 2:489
Oceania, healthcare systems in, 2:787–791
nucleoside reverse transcriptase inhibitors, 1:40
oculopharyngeal muscular dystrophy (OPMD),
null hypothesis, 1:64
3:1152–1153
nurse-midwives, 1:87–88
odds ratio (OR), 1:355
nurse practitioners, 1:76–77, 3:1425
Office of Environmental Management (EM), 2:489
Nurses Health Study (NHS), 2:510, 3:1254–1256
Office of Health and Safety and Security (HSS),
nurses/nursing, 1:105–106
2:490
nursing research, 2:510, 3:1190–1191, 1254–1256
Older Americans Act, 1:16, 17
Nüsslein-Volhard, Christiane, 3:1017
olecranon bursitis, 4:1601
nutrition, 1:31, 95, 307–308, 352, 360–361, 2:471,
oligodendrogliomas (ODG), 1:291
524–527, 3:1256–1259, 4:1474, 1525–1526,
Oliver, C. P., 3:1017
1577–1578, 1746–1749
Olympic Games, 1:166
nutritional iron deficiency anemia (IDA), 1:133
Oman, 3:1278
nutritionists, 3:1259–1260
Omran, A. R., 3:1451
Nyswander, Dorothy Bird, 3:1451–1452
onchocerciasis, 1:269, 3:1138, 1278–1279, 4:1487– 1488, 1684
O
oncologists, 1:330–331, 392, 3:1279–1280
obesity, 1:32, 106–107, 185, 273, 301, 2:503, 525,
oncology, 1:116–117, 3:1280–1283, 1445–1446
629, 3:1124, 1249–1250, 1255, 1256, 1261–
Open Airways for Schools, 1:103
1266, 4:1578
open-heart surgery, 2:740
Obesity Abatement program, 1:31
Operation Lindbergh, 4:1651
obsessive-compulsive disorder (OCD), 1:151, 153,
ophthalmologists, 3:1283
3:1115, 1266–1268 obstetric anesthesiology, 3:1071 obstetric fistula, 1:321, 3:1240–1241, 1268, 1270– 1271
ophthalmology, 1:77–78, 2:941–942, 3:968, 1284– 1286 opiate abuse, 2:841–843, 3:1420 Oppenheimer, Steven B., 4:1462, 1463, 1464
obstetricians, 3:1269, 1353–1354
optometrists, 3:1286
obstetric nurses, 1:175–176
oral cancer, 2:779, 3:1287–1289
obstetrics, 1:88–89, 3:1269–1272
oral contraceptives, 3:1255
obstructive sleep apnea (OSA), 3:1264
oral deformities, 2:651
occupational health, 3:1272–1274
oral glucose tolerance test (OGTT), 1:98, 2:502, 503,
occupational injuries, 3:1274–1275
506, 510
occupational medicine, 1:27, 89–90, 3:1275–1276
oral health, 1:96
Occupational Safety and Health Administration
oral rehydration salts (ORS), 2:522, 523, 3:1289
(OSHA), 1:166, 167, 235, 3:1145, 1276–
oral rehydration therapy (ORT), 1:405, 3:1289
1277, 4:1510
oral surgeons, 3:1289–1290
Occupied Palestinian Territory (OPT), 3:1324
organ donation, 3:1290–1291
Index
Organization for Economic Cooperation and Development (OECD), 1:12 Organ Procurement and Transplantation Network (OPTN), 2:818, 3:977, 4:1709 organ procurement organizations (OPOs), 3:1290, 4:1709 organ transplantation, 2:818–819, 883, 885, 3:972,
I-45
otoacoustic emissions (OAE), 2:476 otolaryngologists, 3:1307 otolaryngology, 3:1307–1308 otology, 3:1309–1311 outer ear, 2:573, 575–576 “Out of Africa” hypothesis, 2:710 outpatient medical treatment, 3:1311
977–978, 1026–1027, 1036–1037, 1292,
ovarian cancer, 3:1311–1313
1326–1327, 4:1633, 1709
ovarian neoplasms, 2:766
orphan diseases (rare diseases), 4:1469–1471
overanxious disorder, 1:151, 152
Orringer, Mark B., 2:623
overflow incontinence, 2:896
Orta, Garcia de, 2:784
over-the-counter (OTC) drugs, 3:1313–1315,
orthodontics, 1:83–84
1361
orthomolecular medicine, 3:1292–1294
overtraining, 4:1599
orthopedics, 1:78–79, 3:1294–1296
Owens, R. B., 4:1467
orthopedists, 3:1296
ozone, 1:50, 3:1316–1317
orthostatic hypotension, 2:654, 656 orthothanasia, 2:480
P
Osgood-Schlatter disease, 3:982
pacemakers, 4:1777
Osler, William, 2:758, 3:1297
Pacific Islander populations, 1:169–171
osteitis deformans, 3:1319–1320
Packer, Kerry, 4:1723
osteoarthritis, 1:161–162, 2:773, 850–851, 3:983,
Paffenbarger Research Center (PRC), 1:96
1183, 1213, 1297–1299, 4:1540–1541, 1770
Paget, James, 1:277, 3:1319
osteogenesis imperfecta (OI), 1:280, 3:1299–1300
Paget’s disease of bone, 1:277,
osteology, 3:1301
osteomalacia, 1:277, 278
pain, 3:1320–1322
osteomyelitis, 3:1213
Pakistan, 3:1322–1323
osteonecrosis (ON), 1:279, 3:1301–1302
Palau, 3:1323
osteopathic manipulative treatment (OMT), 1:201,
pa-leng, 1:154
353
3:1319–1320
Palestine, 3:1324
osteopathic medicine, 1:67
palliative care, 2:479, 480
osteopathy, 1:107–108, 200, 3:1302–1305
Palmer, B. J., 1:404
osteopenia, 1:282, 2:580
Palmer, Daniel David, 1:403–404
osteopetrosis, 1:278
Panama, 3:1324–1325
osteoporosis, 1:277, 279, 280–281, 282, 331,
Pan American Health Organization (PAHO),
3:1305–1306 osteosarcoma, 1:276, 278, 337
3:1325–1326 panax ginseng, 1:376
I-46
Index
pancreas:
Pasteur Institute, 3:1341
cancer of, 3:1327–1329
pasteurization, 3:1342–1343
diseases of, 3:1329–1331
Patarroyo, Manuel, 3:1053
function of, 1:57
patellar dislocation, 3:982
transplantation of, 3:1326–1327
patent ductus arteriosus (PDA), 1:440, 441, 2:814
pandemics, 2:915, 917
Pathet Lao, 3:994
panic disorders, 1:152, 154, 311
pathogen-associated molecular patterns (PAMPs),
pantothenic acid, 4:1748
2:919
papatasi fever, 3:1138
pathogenic organisms, 1:236
papillary thyroid cancer, 4:1664
pathogens, 2:909–910
Pap smear, 1:367–368, 2:763, 766, 859, 4:1731
pathologists, 3:1343–1344
Papua New Guinea, 3:1331–1332
pathology, 1:118, 3:1344–1346
Paracelsus, 3:1389
pathophysiology, 3:1346–1347
Paraguay, 3:1332–1333
patientINFORM, 1:98
Paralympic Games, 1:166
Patient Protection Act II, 1:104
paralysis, 3:1333–1334, 4:1594
Patient’s Bill of Rights, 1:104
paralytic polio, 3:1395–1398
Pauling, Linus, 1:435, 3:1293, 1347, 4:1542
paramyxovirus, 1:434, 3:1148, 4:1515
Pavlov, Ivan, 3:1110, 1440, 1444
paranasal sinus cancer, 3:1252
Pearson, Karl, 2:697
paraplegia, 3:1334
Peate, W. F., 4:1552
parasites, 1:23, 134, 2:583–584, 944–946, 4:1523,
Pecquet, Jean, 3:1282
1535 parasitic diseases, 1:371–372, 3:1009, 1335–1336, 4:1683–1684
Péczely, August von, 2:950 Péczely, Ignatz von, 2:950 pediatric failure to thrive, 2:652
parathyroid disorders, 3:1336–1337
pediatricians, 4:1755–1756
Paré, Ambroise, 4:1632
pediatrics, 1:80, 96, 3:1348–1350, 4:1761
Parkinson, James, 3:1228, 1338
Peete, Holly Robinson, 1:192
parkinsonian tremor, 3:1142
pellagra, 4:1746–1747
Parkinson’s disease (PD), 2:482, 869, 3:1140–1141,
pelvic floor, disorders of, 3:1426
1228–1229, 1338–1340, 4:1681 parotid gland, 4:1514
pelvic inflammatory disease (PID), 1:404, 2:912, 4:1534
Partners in Health (PIH), 2:658
Pemberton, John, 2:934
passive immunity, 1:9, 3:1340–1341
Penicillium, 1:145, 146
passive immunization, 2:882
penile cancer, 3:1350–1351
Pasternak, Boris, 4:1503
penis, 3:1058
Pasteur, Louis, 1:207, 215, 228, 411, 2:883, 3:1341,
peppermint, 2:834
1342, 1450, 1451, 4:1461, 1632
peptic ulcer disease (PUD), 3:1352–1353, 4:1700
Index
percutaneous transluminal coronary angioplasty (PTCA), 1:141
I-47
pharmacopeia/pharmacopoeia, 3:1371–1372 pharmacy, 3:1372–1373
Peretti, Massimiliano, 1:230
Phelps, Michael, 3:1283
perimenopause, 3:1103
phenotype, 2:724, 3:1373
perinatologists, 3:1353
phenylketonuria (PKU), 1:251, 2:903, 3:1374–1375
perinatology, 3:1353–1354
pheochromocytoma, 3:1375–1376
periodontitis, 2:515, 761–762
Philip II, 3:1123
peripheral nerve disorders, 3:1354–1356
Philippines, 2:788–789, 3:1376–1377
peripheral nervous system (PNS), 1:292, 3:1226,
phobias, 1:152–153
1230
phrenology, 1:455, 3:1377–1378
peripheral vascular disease (PVD), 2:504
phylogenetics, 3:1378–1379
peritoneal dialysis, 3:976
physiatry, 3:1379
Perls, Fritz, 3:1448
physical abuse, 1:381, 382
pernicious anemia, 1:133
physical fitness/exercise, 2:636–640
Perrotta, Raffaele, 3:1138
physical therapy, 3:1379–1380
Persian Gulf War, 1:48
physics, medical, 3:1086–1087
personal health information (PHI), 2:805, 806
physiology, 3:1380–1382
personality testing, 2:520
phytotherapy, 2:835
pertussis (whooping cough), 1:11, 149, 2:882, 908,
Piaget, Jean, 1:19, 387–388, 3:1442
4:1759–1760
Pickens, Allen, 2:623
Peru, 2:800, 3:1356–1357
Pickford, Mary, 1:114
Perutz, M. F., 1:456
Pierce, Nathaniel F., 3:1289
pervasive development disorder, 1:187, 189
Pinkel, Donald, 3:1283
pesticides, 2:605, 3:1357–1360
pink eye, 1:445–446
Peter, J. B., 3:1149, 1157
Pinto, M. J., 3:1053
Peter the Wild Boy, 1:189
Pirajno, Alberto Denti di, 2:787, 3:1018
Phage Group, 4:1756
piriformis syndrome, 4:1602
phagocytes, 2:879, 919
Pirogov, Nikolai, 2:938
phantosmia, 4:1646
Pitt, Peter, 2:746
pharmaceutical industry, worldwide, 3:1360–
pituitary adenoma, 1:292
1365
pituitary disorders, 2:599, 3:1382–1383
pharmacists, 1:108–109, 3:1365–1366
pituitary tumors, 3:1383–1384
pharmacoepidemiology, 2:940–941, 3:1366–1367
Pizzorno, Joseph E., 3:1208
pharmacogenetics, 3:1367
placebo, 3:1384–1385
pharmacogenomics, 3:1367, 1368
plague, 1:232, 239–240, 2:612, 667, 883, 3:1083,
pharmacologists, 3:1368–1369 pharmacology, 3:1369–1371
4:1691 Planned Parenthood, 1:105
I-48
Index
plantar fasciitis, 2:682, 4:1603
polymorphism, 3:1400–1401
plasma, 1:271
polymyalgia rheumatica, 3:1401–1402
plasmacytoma, 2:824
polymyositis, 3:1149, 1157
plasmids, 2:728
polyps, 1:131–132, 426
Plasmodium, 3:1050, 1335, 4:1679
Pontiac fever, 3:1008
platelets, 1:264, 271, 281
porencephaly, 1:298
Plato, 3:1433
porphyria, 3:1402–1403
platyhelminths, 3:1083, 1084
Porter, Rodney, 2:883
pneumococcal disease, 1:11
Portugal, 3:1404–1405
pneumocystis carinii (PC), 1:36
port wine stain, 1:255
Pneumocystis jiroveci, 1:45
positron emission tomography (PET), 1:72, 295
pneumonia, 3:1385–1387, 4:1484–1485
postabortion care (PAC), 1:4
podiatrists, 3:1387
post-concussion syndrome, 1:439
podiatry, 1:109–110
post-exposure prophylaxis (PEP), 1:40, 46
point mutation, 3:1387–1388
post-infectious arthritis, 1:165
point of service (POS), 3:1388–1389
postmenopause, 3:1103
point prevalence, 3:1422
postpartum blues, 3:1406
point source air pollution, 1:48
postpartum depression, 3:1405–1408
Poison Control Centers, 2:865, 866, 4:1674
postpartum psychosis, 3:1406
poisons/poisoning, 3:1389–1391
post-polio syndrome (PPS), 3:1395, 1397–1398
accidental, 3:1389–1390 household, 2:865–866 lead, 3:997–998
post-traumatic stress disorder (PTSD), 1:151, 153, 3:1115, 4:1619, 1620 Pott, Percivall, 1:337, 338, 2:890, 3:1282
Poland, 3:1391–1393
poverty, 1:19, 211
polio, 1:11, 2:882, 908, 3:1395–1398, 4:1507
poxviruses, 4:1745
poliomyelitis, 1:26, 29, 104, 147
Prader, Andrea, 3:1408
poliosis, 2:769
Prader-Willi syndrome (PWS), 3:1408–1409
polio vaccine, 3:1396
precocious puberty, 2:755
Pollack, Otto, 2:736
preeclampsia, 2:848, 3:1409–1410
pollution, 2:901–902, 3:1393–1394
preferred provider organization (PPO), 3:1410–
polyarteritis nodosa, 4:1738
1411
polychlorinated biphenyls (PCBs), 2:674, 4:1553
preferred provider organizations (PPOs), 3:1389
polycystic kidney disease (PKD), 3:972, 1219,
pregestational diabetes (PGDM), 2:506
1398–1399 polycystic ovarian syndrome (PCOS), 1:7, 2:766 polymerase chain reaction (PCR), 2:707, 3:992, 1009, 1041, 1399–1400
pregnancy, 3:1126–1127, 1409–1410, 1411–1415, 1418–1420, 4:1479, 1501–1502, 1590–1591 AIDS transmission in, 1:38 bipolar disorder and, 3:1065
Index
diabetes mellitus (DM) and, 2:505–506
processive stressors, 4:1620
ectopic/tubal, 2:765
proctitis, 1:132
education and advocacy of, 1:110–111
proctology, 3:1426–1427
gestational diabetes with, 1:98
progestin-only pill (POP), 1:248, 249
high-risk, 2:847–849
programmed cell death, 3:1427
kidney abnormalities associated with, 3:974
progressive necrotizing myelopathy, 4:1593
smoking and, 4:1569–1570
progressive neurological deficit, 1:289
substance abuse during, 3:1415–1416
prolapse:
in teenage populations, 1:22, 4:1648–1650
rectal, 1:132
unwanted, 1:22
uterus, 2:765
pregnancy loss, 3:1416–1417
prospective studies, 3:1427–1428
premature babies, 3:1417–1418, 4:1488
prostate:
premenstrual syndrome (PMS), 2:764, 863, 3:1106, 1108–1109
I-49
cancer of, 3:1428–1430 diseases of, 3:1430–1431
premenstrual tension (PMT), 3:1108
prostate-specific antigen (PSA), 3:1429, 1430–1431
prenatal care, 3:1418–1420
prostatitis, 2:926, 4:1721
prepatellar bursitis, 3:982–983
prostheses, 1:165–166
prescription drug abuse, 3:1420–1422
protease inhibitors, 1:40
preterm labor, 2:848
protein, 2:525, 3:1246
prevalence, 3:1422
protein-energy malnutrition (PEM), 3:1066–1067
preventive care, 3:1422–1424
proton pump inhibitors (PPI), 4:1615
preventive medicine, 1:27, 92, 257
protozoa, 2:945–946, 3:1335, 4:1535
PRICEMM (protection, relative rest, ice,
pruritis, 1:131
compression, elevation, medication and
Prusiner, Stanley, 2:675
modalities), 1:325
pseudogout/gout, 1:164, 2:747–750
primary bone cancer, 1:278
psoriasis, 1:163, 3:1432–1433, 4:1551
primary care, 3:1425–1426
psoriatic arthritis, 1:163–164
primary care physician (PCP), 2:807
psychiatric nurses, 3:1112
primary CNS lymphoma (PCNSL), 1:290
psychiatrists, 3:1433
primary hypogonadism, 2:911, 912
psychiatry, 3:1110–1112, 1433–1438
primary systemic amyloidosis (PSA), 1:282
psychogenic movement disorders, 3:1142
primitive neuroectodermal tumors (PNET), 1:292
psychoimmunology, 3:1439
Principe and Sao Tome, 4:1518–1519
psychological testing, 2:518–520
Prinzmetal’s angina, 1:139, 140
psychologists, 3:1439–1440
prion diseases, 1:287
psychology, 1:111, 3:1440–1444
priority of impressions, 3:1100
psychoneuroimmunology (PNEI), 3:1444–1445
probiotics, 1:376
psychooncology, 3:1445–1446
I-50
Index
psychosomatic diseases, 4:1620 psychotherapy, 2:494–495, 3:1113, 1446–1449 puberty, 1:17, 18 public health, 1:112–113, 174, 2:602–603, 631, 794–796, 3:1074, 1173–1174, 1349–1350, 1449–1453, 4:1578–1579, 4:1711–1712
Racial and Ethnic Approaches to Community Health (REACH), 3:1166 radiation, 1:338 background, 1:199–200 exposure to, 4:1462–1464 radiation therapy, 1:377, 392, 429
Public Health Assessments (PHAs), 1:33
radiologists, 4:1464–1465
Public Health Security and Bioterrorism
radiology, 4:1465–1466
Preparedness and Response Act, 1:240
radiotherapy, 1:343
puerperal fever, 3:1413
radon, 1:200, 4:1467
pulmonary embolism (PE), 3:1454–1455
Rafinesque, Constantine, 2:836
pulmonary fibrosis, 3:1455–1456
Rajneeshee Cult, 1:231, 238
pulmonary tuberculosis, 4:1685
Ramón y Cajal, Santiago, 3:1236
pulmonology, 3:1456–1458
Ramsay, William, 4:1467
Purcell, Edward, 3:996
Ramsay Hunt, James, 4:1468
Putin, Vladimir, 4:1504
Ramsay Hunt syndrome, 4:1468
pyelonephritis, 3:1219, 4:1721
randomized clinical trials, 4:1468–1469
pyloroplasty, 4:1616
rare diseases, 4:1469–1471
pyrexis, 2:663–664
rational emotive behavioral therapy (REBT),
pyridoxine (B6), 4:1748
3:1448 Raynaud, Maurice, 4:1471
Q
Raynaud’s disease, 3:1149, 4:1471–1472
Qadhafi, Muammar al, 3:1018
Raynaud’s phenomenon, 4:1471, 1472
Qatar, 4:1459
reactive oxygen species (ROS), 1:150
Q-fever, 1:232
reading disorders, 3:1001
qi (ch’i), 1:12–13
Reagan, Ronald, 1:37, 105, 2:942, 3:1189, 4:1481
qigong, 1:67
recessive allele, 1:60
quadriplegia, 3:1334
recessive inheritance, 2:845
quality-adjusted life-years (QUALYs), 3:1452
Recklinghausen, Friedrich Daniel von, 3:1344
Quatrefarges, Xavier, 2:786
recombination, 1:458
Quetelet, Adolphe, 1:272
Recommended Dietary Allowance (RDA), 1:224,
Quinlan, Karen Ann, 1:432 Quirino, Elpidio, 3:1377
3:1258, 4:1746 rectal cancer, 1:127–129, 130, 337 Recto, Claro M., 3:1377
R
rectum, diseases/disorders of, 1:129–132, 3:1426
rabbit hemorrhagic disease, 1:229
red blood cells (RBCs), 1:133–135, 270, 281
rabies, 4:1461–1462, 1742
Red Crescent, 2:935–936, 937–939
Index
Red Cross, 1:113–115, 2:932–933, 935–936, 937–
retinal disorders, 4:1487–1488
939
retinal pigment epithelium (RPE), 1:34
Reddy, Helen, 1:15
retinoblastoma, 1:10, 391, 2:735, 4:1488
red eye, 1:445–446
retinopathy of prematurity (ROP), 4:1488
red wine, 1:376–377
retrospective studies, 4:1489
refeeding syndrome, 3:988
retrovirus, 1:37
reflex sympathetic dystrophy (RSD), 4:1472–
Rett, Andreas, 1:189, 4:1489
1473
I-51
Rett syndrome (RS), 1:187, 189–190, 4:1489–1490
refractive errors, 2:645, 4:1473–1474
Retzius, Anders, 1:454–455
“refrigerator mothers,” 1:190
Reye syndrome, 1:380, 2:915, 4:1490–1492
Refsum’s disease, 3:1119
rhabodomyosarcoma, 1:392
refugee health, 4:1474–1475
Rhee, Syngman, 3:985
regional source air pollution, 1:48
rheumatic fever (RF), 2:815, 4:1492
regulatory T cells (Treg), 1:61
rheumatic heart disease, 4:1492
regulatory toxicology, 4:1674
rheumatoid arthritis (RA), 1:162–163, 192, 194,
rehabilitation, 4:1475–1477
195, 290, 2:851, 852, 964–965, 3:1213,
Rehnquist, William, 4:1665
4:1493–1496, 1541, 1770–1771
Reichstein, Tadeus, 1:14
Rh factor, 3:1269
Reiki therapy, 1:67
rhinitis, 3:1251–1252
Reil, Johann Christian, 3:1435
rhinosinusitis, 4:1546–1547
Reiter syndrome, 1:163
rhinovirus, 4:1483–1484
Remaking American Medicine, 1:98
Rhodes, Cecil, 4:1775, 1776
renal disease, 2:513–514
Rhogam, 3:1269
renal endartectomy, 1:141
rhythm methods, 1:248
renal failure, 3:975–976
Riberio, U., 2:622
renin, 3:1218
riboflavin (B2), 4:1748
repetition, 3:1100
ribonucleic acid (RNA), 3:1242
repetitive strain injury (RSI), 3:1275
ricin, 1:233
reproductive health, 4:1477–1483
rickets, 1:277, 278–279, 4:1496–1497, 1746
reproductive medicine, 1:116
Rickettsia, 1:233, 2:583–584
Research Diagnostic Criteria (RDC), 4:1652
right-to-die issues, 1:432
respiratory diseases, 1:310–311, 408–410, 2:595–
ringworm, 3:1057, 4:1553
597, 3:1385–1387, 4:1483–1487, 1532–1533
Ripley, William Z., 1:455
respiratory distress syndrome (RDS), 1:103
risk assessment, 4:1509–1510
respiratory syncytial virus (RSV), 1:434, 3:1207
risk management, 4:1509
respiratory system, 1:310–311
river blindness, 1:269, 3:1138, 1278–1279, 4:1487–
retinal detachment, 2:647
1488, 1684
I-52
Index
Roberts, A., 2:601
Sachs, Bernard, 4:1647
Robins, James, 2:614
Sachs, Jeffrey, 4:1508–1509
Rockefeller, John D., 3:1297
Safe Kids, 1:396
Rodbell, Martin, 3:1187, 1369, 4:1497
Safe Motherhood Initiative, 3:1271, 4:1479
roentgenology, 4:1498–1499
safety, 1:396–397, 4:1509–1511
Roentgen/Röntgen, Wilhelm Conrad, 1:343,
Saint Kitts and Nevis, 4:1511–1512
3:1282, 4:1464, 1465, 1466, 1497–1498, 1632
Saint Lucia, 4:1512–1513
Roe v. Wade, 3:1203, 4:1481
Saint Vincent and the Grenadines, 4:1513–1514
Rogers, Carl, 3:1448
salivary glands, 4:1547–1549
rohypnol, 2:473
cancers of, 2:780
Romania, 4:1499–1500
disorders of, 4:1514–1515
Roosevelt, Franklin D., 3:1395
tumors, 4:1515
rosacea, 4:1500–1501
salivary stones (sialolithiasis), 4:1514–1515
Rosenberg, Barnett, 3:1283
Salk, Jonas, 3:1395, 1396, 1451, 4:1507
Ross, Emanuel, 3:987
salmon bias, theory of, 2:853
Ross, Ronald, 1:411, 3:1053
salmonella infections, 1:231, 238, 361, 2:674, 676,
rotator cuff, injuries of, 4:1539–1540, 1600
678, 4:1515–1516
Rotavirus, 1:394, 2:883, 4:1745
Samoa, 4:1516–1517
Rothman, Kenneth, 2:614
sand fly, 3:1138
Rous, Peyton, 4:1724
Sanger, Margaret, 4:1480
Roussimoff, Andre, 3:1384
sanitation, 2:872–873, 3:1049
Roux, Emile, 3:1341
Sanjose, Silvia de, 2:771
Roxas, Manuel, 3:1377
San Marino, 4:1517–1518
RU-486, 1:4, 3:1203
Sao Tome and Principe, 4:1518–1519
rubella, 1:11, 26, 253, 2:882, 908, 3:1202, 4:1501–
sarcoidosis, 1:30, 4:1519–1520
1502, 1744, 1745
sarcoma, soft tissue, 4:1579–1581
Rush, Benjamin, 3:1435
sarin gas, 1:231, 233, 238
Russell’s sign, 2:579
satellite DNA, 4:1520–1521
Russia, 4:1502–1504
saturated fats, 4:1521
Rutherford, Ernst, 4:1467
Saudi Arabia, 4:1522
Rwanda, 4:1504–1505
saw palmetto, 1:377, 2:833, 834
Ryan, F. J., 3:1004
scabies, 1:23, 4:1553
Ryan White Care Act, 3:1162
scalp acupuncture, 1:13 scaphoid fracture, 4:1602
S
Schally, Andrew, 3:1224
Sabin, Albert, 3:1396, 1451, 4:1507
Schiavo, Michael, 1:432–433
Sabin, Florence R., 4:1508
Schiavo, Terri, 1:432–433
Index
Schilder, Paul Ferdinand, 3:1147
sensorineural hearing loss, 2:474, 475
schistosomiasis, 4:1523, 1678, 1684
sensory-related disabilities, 2:499
schizencephaly, 1:298
sentinel lymph node (SLN), 1:303
schizophrenia, 3:1115, 4:1523–1525
separation anxiety, 1:151–152
Schneider, Kurt, 3:1435
sepsis, 1:205
Scholl, William Mathias, 3:1387
septic arthritis, 1:164–165
Schönbein, Christian Friedrich, 3:1316
Serbia, 4:1531–1532
School Nutrition Association (SNA), 4:1525–1526
serenity, 4:1619
school phobia, 1:152–153
serpentine asbestos, 1:167
Schüller, Arthur, 3:1234
Severe Acute Respiratory Syndrome (SARS),
I-53
schwannomatosis, 3:1225
1:184, 336, 2:954, 960, 3:991, 4:1532–1533,
Schwarzenegger, Arnold, 1:79
1586, 1678, 1684, 1740
Schweitzer, Albert, 2:786, 4:1526
Severe Combined Immune Deficiency (SCID), 2:716
Sciammarella, Joseph, 4:1553
Severini, Marco Aurelio, 3:1282
scleroderma, 1:194, 3:1183, 4:1526–1527
sex hormones, disorders of, 2:599
sclerosing cholangitis, 1:226
sex-linked diseases, 1:293
scoliosis, 4:1528–1529
sexual abuse, 1:381, 382
scrapie, 1:288
sexual health, 4:1478–1479, 1482–1483
scrotum, 3:1057, 1058
sexually transmitted diseases (STDs)/sexually
Scudder, John Milton, 2:837
transmitted infections (STIs), 1:4, 22, 40,
scurvy, 4:1746
45, 105, 173, 204–205, 249, 250, 253, 2:746–
seasonal affective disorder, 2:496
747, 765, 960, 3:1170–1171, 1351, 1424,
seborrhoeic dermatitis, 2:498
4:1474, 1478, 1479–1482, 1533–1536, 1649,
second-hand smoke, 1:195, 2:608–609, 3:1034,
1650, 1732, 1743
4:1570
sexual slavery, 1:370
second impact syndrome, 1:439
Seychelles, 4:1537
secular trend, 1:18, 19
Shafai, Mozafar, 2:946
seizures, 1:294, 2:617–618, 865–866, 3:1229,
Shape Up America, 1:107
4:1529–1530 selective serotonin reuptake inhibitors (SSRIs), 1:20, 124, 3:1113, 1268, 1436, 1446
Shapiro, Sam, 3:1283 Sheehan’s syndrome, 3:1383 Sheehy, Gail, 3:1105
selenium, 4:1749
Shigella, 1:204
Selye, Hans, 1:407, 4:1618–1619, 1620, 1621
shingles (herpes zoster), 1:39, 220, 381, 4:1538,
Semmelweis, I., 1:411, 3:1269, 1413, 1451
1742
Sénac, Jean-Baptiste, 1:347
shinkeishitsu, 1:154
Senegal, 4:1530–1531
shin splints, 4:1603
seniors, exercise for, 2:635–636
shivering, 2:876
I-54
Index
Shoemaker, Eugene Merle, 1:15
sleep disorders, 3:1412, 4:1555–1557
shoulder injuries and disorders, 4:1538–1541,
sleepwalking, 4:1557
1599–1600
Sloan, Louise, 4:1576
shunts, 2:871
Sloane, Hans, 3:1371
sick building syndrome, 2:902
Slovakia, 4:1557–1558
sickle cell anemia (SCA), 2:720, 4:1541–1543
Slovenia, 4:1559
sickle cell disease (SCD), 4:1541–1543
small-for-gestational-age (SGA) babies, 3:1416
Sierra Leone, 4:1543–1544
small intestine cancer, 4:1560–1561
Sihanouk, Norodom, 1:332, 333
smallpox, 1:11, 26, 147, 232, 238, 239, 394, 2:881,
silicone implants, 1:308, 309
882, 884, 909, 3:1202, 1345, 1369, 1451,
Simon, Gustav, 4:1723
4:1561–1565, 1745
Simpson, Keith, 3:1301
small vessel vasculitis, 4:1738
Simpson’s paradox, 3:1117
smell and taste disorders, 4:1645–1646
Sims, James Marion, 3:1269
Smellie, William, 3:1269
Singapore, 4:1544–1545
Smith, Anna Nichole, 3:1085
single photon emission computed tomography
Smith, Dannie Lynn, 3:1085
(SPECT), 1:295
Smith, Edwin, 4:1631
sinusitis, 3:1252, 4:1546–1547
Smith, P. E., 2:601
situational phobias, 1:152–153
smokeless tobacco, 1:337, 4:1565
Sjogren’s syndrome, 1:290, 4:1514, 1547–1549
smoking, 1:103, 136, 258, 301, 337, 409, 427, 2:596,
skier’s thumb, 4:1602, 1605
792, 814, 817, 902, 3:1033–1036, 1037, 1207,
skin:
1246, 1255, 1412, 1415, 1423, 1452, 4:1486,
acne in, 1:6–7
1566–1569
burns of, 1:321–323
cessation methods, 4:1573–1574
cellulitis of, 1:358–359
effects of second-hand, 1:195, 2:608–609, 3:1034,
dermatitis of, 2:497–498 diseases of, 3:1182–1183, 1432–1433, 4:1500– 1501, 1526–1527, 1551–1554
4:1570 during pregnancy, 4:1569–1570 by teens/youth, 4:1571–1573
layers of, 1:321–323
Snell, George, 3:1147
photodamage of, 4:1629
Snellen, Herman, 4:1576
pigmentation disorders of, 4:1554–1555
Snellen’s chart, 4:1576
skin cancer, 1:337, 4:1549–1551, 1629, 1701– 1702
snoring, 3:1252 Snow, C. P., 3:1378
Skinner, B. F., 3:1110, 1440
Snow, J., 1:411, 2:612, 613, 3:1083, 1451
Skipper, Howard, 3:1283
Social Darwinism, 2:723
skull fractures, 2:776, 777
social development, 1:388–389
sleep apnea, 4:1556–1557
social hygiene, 1:115
Index
social phobias, 1:152–153
“speed,” 3:1119–1122
Social Security Act, 1:17
Spencer, Herbert, 2:723
social workers, 3:1112
spermicides, 1:247–248
Society for Healthcare Epidemiology of America
sperm washing, 1:44
(SHEA), 4:1577 Society for Neuroscience (SfN), 3:1236–1237 Society for Nutrition Education (SNE), 4:1577– 1578 Society for Public Health Education (SOPHE), 4:1578–1579 Society of Research in Child Development (SRCD), 2:904 sodium, 4:1749
spider bites, 4:1589 spina bifida (SB), 1:252, 3:1222, 1232, 1233, 4:1590–1591 spinal cord: diseases of, 2:482–483, 4:1528, 1591–1594 managing with back pain, 1:200–201 vertebral segments of, 1:369–370 spinal cord injuries (SCI), 3:1212–1213, 4:1594– 1595
soft tissue sarcoma, 4:1579–1581
spinal epidural hemorrhage, 4:1594
solid tumors, 1:391
spinal muscular atrophy (SMA), 4:1595–1596
Solomon, George F., 3:1439
spinal stenosis, 1:202–203, 4:1592, 1596–1597
Solomon Islands, 4:1581–1582
spinal subarachnoid hemorrhage, 4:1593
Solovin, Sergei, 4:1576
spindle cell sarcoma, 1:276
SOMA, 1:457
Spitzer, Robert, 3:1436
Somalia, 4:1562, 1582–1583
spleen diseases, 4:1597–1599
somatic cell nuclear transfer (SCNT), 1:99, 4:1608–
splenomegaly, 4:1598
1609, 1610–1611
spondyloarthropathies, 1:163–164
somatic gene therapy, 2:715
spondylolisthesis, 4:1592
somatic mutation, 1:10, 4:1583–1584
spontaneous abortion, 1:1
Soper, Fred L., 4:1584
sports injuries, 4:1599–1603
Soros, George, 3:1452
sports medicine, 1:93–94
South Africa, 1:178, 4:1584–1585
sprains and strains, 4:1604–1605, 1769
South America, 2:797–801
Spurzheim, Joseph Caspar, 3:1377
soy, 2:834
squamous cell carcinoma, 3:1287
Spain, 4:1585–1587
squamous intraepithelial lesion (SIL), 1:367
Spanish flu epidemic, 4:1743
Sri Lanka, 4:1605–1606
spasmodic dysphonia, 4:1589
St. John’s wort, 2:832, 833–834
specific phobias, 1:152–153
stable angina, 1:139, 140
specific secondary response of immune system,
Stadler, Lewis, 3:1073
2:879 speech and communication disorders, 4:1587– 1589
I-55
Stalin, Josef, 4:1503 standards development organizations (SDOs), 4:1510
I-56
Index
Stanford-Binet Intelligence Scale, 2:499
stress incontinence, 2:896
Stanford classification system, 1:137
stress treadmill test, 1:347
Staphylococcus aureus, 1:204, 205, 324, 359, 2:674,
Strohl, Andre, 2:758
887, 3:1107–1108, 4:1606–1607 Staphylococcus infections, 1:145, 146, 205, 4:1606–1607 State Children’s Health Insurance Program (SCHIP), 2:802, 3:1091 Stead, Gilbert, 4:1464
stroke (CVA), 3:1227, 1334, 4:1623,
1676–1677
Studies to Advance Autism Research and Treatment (START), 1:191 Study of Women’s Health Across the Nation (SWAN), 3:1106
Steiner, Rudolf, 1:68
stuttering, 4:1588
Steinert’s disease, 3:1152
subacromial bursitis, 4:1600
Stelluti, Francesco, 1:207
subarachnoid hemorrhage (SAH), 1:138–139
stem cells/stem cell transplantation, 1:99, 2:716,
subdural hematoma, 2:777
3:1146, 4:1607–1612
sublingual glands, 4:1514
Stensen’s duct, 4:1514
submandibular glands, 4:1514
stents, 1:141
substance abuse, 3:1196–1197, 1206–1207, 1370,
Steptoe, Patrick, 3:1269 Stern, Judith S., 1:107 steroids, anabolic, 1:126–127
1415–1416 Substance Abuse and Mental Health Services Administration (SAMHSA), 4:1623–1624
stethoscope, 1:348, 349, 408
substance-induced anxiety disorder, 1:154
Stewart, Alice, 4:1612
Sudan, 4:1624–1625
Stickler, Gunnar B., 4:1612–1613
sudden infant death syndrome (SIDS), 1:251,
Stickler syndrome, 4:1613
2:609, 779, 904, 905, 908, 3:1185, 1415, 1420,
Still, Andrew Taylor, 1:107, 3:1303, 1304
4:1542, 1569, 1625–1627, 1760
Still, George, 1:181 stillbirth, 1:223
suicide, 1:20, 2:495, 496, 3:1065, 1115, 1390, 4:1627–1628
stomach cancer, 4:1613–1614
Suit, Herman, 3:1283
stomach disorders, 4:1615–1617
Sulston, John E., 3:1427
Stowell, Thomas E. A., 3:1301
Sumner, William Graham, 2:723
strains and sprains, 3:1149, 4:1604–1605, 1769
sun exposure, 4:1629, 1630–1631
Strax, Philip, 3:1283
sun protection factor (SPF), 4:1629, 1630–1631
“strep throat,” 4:1660–1661
sunscreen, 4:1552, 1629, 1701
Streptococcus infections, 1:359, 2:887, 4:1617–
“super bugs,” 2:747
1618 Streptococcus pneumoniae, 1:203, 204, 311, 4:1617– 1618 stress, 4:1618–1622, 1627
Superfund law, 1:33 surgery, 1:94–95, 3:1125–1126, 4:1631–1633, 1651–1652 Suriname, 4:1634
Index
Surveillance, Epidemiology and End Results Program (SEER), 1:390, 4:1634–1635
I-57
Tay-Sachs disease (TSD), 1:251, 2:893, 3:1118, 4:1470–1471, 1488, 1647–1648
Sushruta, 4:1631
Tazania, 4:1644
Susser, Ezra, 2:615
T cells, 1:61, 193, 195, 2:879, 881, 885, 4:1662
Susser, Mervyn, 2:615
tea tree oil, 2:888
susto, 1:154
teenage pregnancy, 4:1648–1650
Sutherland, Earl W., Jr., 3:1368
Teens Against Tobacco, 1:103
swallowing, disorders of, 4:1661–1662
teeth, impacted, 2:650
Swaziland, 4:1635–1636
telepathology, 4:1650–1651
Sweden, 4:1636–1637
telesurgery, 4:1651–1652
swine flu, 2:917
temporal arteritis, 2:647, 4:1737
Switzerland, 4:1638–1639
temporomandibular disorders (TMDs), 4:1652–
Sydenham, Thomas, 4:1759 syncope, 2:653–656 synkinesis, 1:221
1653 temporomandibular joint (TMJ), 2:650–651, 3:1310, 4:1652
syphilis, 1:22, 23, 2:588, 3:1450–1451, 4:1534
tendonitis of the wrist, 2:773
Syria, 4:1639–1640
tennis elbow (lateral epicondylitis), 4:1769
systemic lupus erythematosus (SLE), 1:30, 192,
Tenorio, Luis, 3:1397
194, 195, 3:1037–1039, 1183 systemic stressors, 4:1620 Szasz, Thomas, 3:1436
tension headaches, 2:782 terrorists/terrorism, chemical/biological weapons in, 1:231–233 testicles, 3:1057, 1058
T
testicular cancer, 3:1058, 4:1653–1654
Tager-Flusberg, Helen, 1:191
tests/testing:
Taiwan, 4:1641–1642
diagnostic, 2:518–520
Tajikistan, 4:1642–1643
genetic testing/counseling, 2:721–722
Takayasu’s arteritis, 4:1737
of intelligence, 2:519–520
Taliban, 1:28
laboratory, 3:992–993
Tamoxifen, 1:374
neuropsychological, 2:520
Tangum, M., 3:1294
of personality, 2:520
Tanner, James Mourilyan, 4:1643
psychological, 2:518–520
Tanner Stages/Tanner Scale, 4:1643–1644
test-tube baby, 1:315
taste and smell disorders, 4:1645–1646
tetanus, 1:11, 26, 149, 2:882, 908, 3:1202, 1340,
Tatum, Edward Lawrie, 3:1003, 1004
4:1654–1656
Taussig-Bing complex, 1:440, 442
tetrahydrocannabinol (THC), 3:1068
Tay, Warren, 4:1647
tetralogy of Fallot (TF), 1:439, 440–441
Taylor, Hugh, 4:1576
Thailand, 1:241, 244, 4:1656–1657
I-58
Index
thalidomide, 1:253
smokeless, 4:1565
Theophrastus, 2:836
See also smoking
therapeutic futility, 2:478, 480
tobacco smoke, environmental (ETS), 2:608–609
therapeutic touch, 1:67
Tobago, 4:1682
thiamine (B1), 1:224–225, 4:1748
tocopherol, 4:1749
Third World, 4:1657–1658
toddlers:
Thomas, E., 2:883, 3:1283
growth and development of, 2:904–907
Thomas, Lewis, 4:1658
health of, 2:907–909
Thomson, Samuel, 2:837
nutrition of, 2:907–909
thoracic aortic aneurysms (TAA), 1:137–138
toe fracture, 4:1603
thoracic outlet syndrome (TOS), 3:1213, 4:1658–
Togo, 4:1670
1659
Tonga, 4:1670–1671
Thorn, George W., 4:1660
total abortion rate (TAR), 1:1–2
throat disorders, 4:1660–1662
total body surface area (TBSA), 1:322
thrombocytopenia, 1:263–264
total fertility rate (TFR), 1:256
thrombotic thrombocytopenic purpura (TTP),
Tourette, Georges Gilles de la, 4:1671–1672
1:264
Tourette syndrome (TS), 3:1141, 4:1671–1672
Thucydides, 2:883
tourism, medical, 3:1088–1090
thymine (T), 2:713
toxic exposures, 1:33–34, 3:1150, 4:1673–1674
thymus cancer, 4:1662–1663
toxicology, 4:1673–1674
thyroid cancer, 4:1664–1665, 1667
toxic shock syndrome (TSS), 3:1107, 4:1470
thyroid diseases/disorders, 1:23, 2:600, 745–746,
toxin-induced myopathies, 3:1150
4:1665–1667
toxins, 3:1389–1391
thyroiditis, 1:194
Toxoplasma gondii, 1:43
thyroid-stimulating hormone (TSH), 1:316
toxoplasmosis, 4:1470
tic disorders, 3:1141, 4:1672
Toy, John, 3:1036
ticks/tick bites, 2:583–584, 3:1040, 4:1668–
trachoma, 1:269, 4:1675
1669 Tidd, Jacob, 2:836 Tierney, Lawrence, 4:1645
traditional birthing assistants (TBAs), 3:1127 Traditional Chinese Medicine (TCM), 1:12–13, 65, 400, 402–403
tinnitus, 4:1669–1670
Trager, William, 3:1053
Tiselius, Arne, 2:707
trans fats, 4:1675–1676
tissue plasminogen activator (TPA), 3:1227
transient ischemic attack (TIA), 3:1227, 4:1676–
Titchener, Edward, 3:1440
1677
T-lymphocytes, 1:9
transmissible mink encephalopathy (TME), 1:288
tobacco, 1:20, 32, 103, 301, 337, 2:792, 902, 3:1134,
transmissible spongiform encephalopathies (TSEs),
1246, 1287, 1423, 4:1486
1:287–289
Index
transplantation of organs, 1:63, 2:818–819, 880, 883, 885, 3:972, 977–978, 1026–1027, 1036–1037,
Tuvalu, 4:1693 twins:
1292, 1326–1327, 4:1633, 1709
fraternal, 2:688–689
transposition of the great arteries (TGA), 1:439, 440 traumatic brain injuries (TBIs), 1:294, 295–296, 438–439 traveler’s health, 4:1678–1681
monozygotic (MZ), 3:1134–1135 Twort, Frederick William, 3:1369 Tyler-Smith, Chris, 4:1520 type 1 diabetes mellitus (T1DM), 1:98, 192, 194,
travel medicine, 4:1677–1678 tremor, 3:1141–1142, 4:1681–1682
I-59
2:503, 504, 507–508, 3:1329 type 2 diabetes mellitus (T2DM), 1:98, 427, 2:501,
trepanation, 4:1631
503, 504, 507, 509–511, 3:1261, 1263, 1329
trichiasis, 4:1675
Type 2 helper T cells (Th2), 1:61
trichomoniasis, 1:22, 4:1734
Type I error, 1:64
Trichopoulos, Deimitrios, 3:1283
typhoid, 1:29, 2:873, 4:1693–1695
trigger finger, 2:773
typhus, 1:233, 2:667, 909
Trinidad, 4:1682 Trisomy-21, 3:1111
U
Trivers, Robert, 2:727
Udovikov, Serge, 1:156
tropical medicine, 4:1683–1684
Uganda, 4:1697–1698
Truhart, R., 2:609, 610
Ukraine, 4:1698–1699
Truman, Harry S, 4:1525
ulcerative colitis (UC), 1:131, 164, 427, 2:701, 704,
Trypanosoma cruzi, 1:371 tuberculosis (TB), 1:29, 42, 102–103, 147, 205–206,
913, 914 ulcers, 4:1699–1700
2:883, 886, 899, 3:1170–1171, 1453, 4:1474,
gastric, 2:704
1486, 1635, 1642, 1684–1685
peptic, 3:1352–1353
tuberous sclerosis/tuberous sclerosis complex (TSC), 4:1686 tubular necrosis, 3:1219 tularemia, 1:232
Ulrichs, Karl Heinrich, 2:706, 858 ultrasound, 2:516–517 ultraviolet (UV) radiation, 1:356, 3:1245, 4:1549, 1700–1702
tumor registries, 4:1686–1688
Underwood, Michael, 3:1395
tumors:
Uniform Donor Card, 3:1290
carcinoid, 1:344–345
United American Nurses, 1:106
solid, 1:391
United Arab Emirates (UAE), 4:1702–1703
Tunisia, 4:1689
United Kingdom Prospective Diabetes Study
Turkey, 4:1689–1690
(UKPDS), 2:505, 510
Turkmenistan, 4:1690–1691
United Kingdom (UK), 2:924–925, 4:1703–1707
Turner, Henry, 4:1691
United Nations Children’s Fund (UNICEF), 1:221,
Turner’s syndrome (TS), 2:721, 754, 4:1691–1693
225, 405, 412, 424, 454, 4:1707–1708, 1760
I-60
Index
United Nations Development Programme (UNDP), 1:51, 149, 157, 158, 183, 185, 208, 212, 215 United Nations Joint Programme on AIDS (UNAIDS), 1:36, 40, 44, 2:961–962 United Nations Office on Drugs and Crime, 1:124 United Nations Secretariat of the Convention on Biological diversity, 1:235 United Nations (UN), 1:245, 437, 3:1453 United Network for Organ Sharing (UNOS), 2:818, 3:977, 1026–1027, 1290, 4:1709 United States, 2:925
United States Health Care Financing Administration, 1:32 United States Health Resources and Services Administration, 1:32 United States Medical Licensing Examination (USMLE), 4:1710 United States Medical Research Institute of Infectious Diseases (USAMRIID), 1:229 United States National Council on Alcoholism, 1:55 United States National Institute for Occupational
healthcare in, 2:801–805
Safety and Health (NIOSH), 1:166, 3:1191–
statistics, 4:1712–1719
1192
United States Agency for Toxic Substances and Disease Registry (ATSDR), 3:1116 United States Army Corps of Engineers, 1:33 United States Cancer Statistics Working Group, 2:622 United States Department of Agriculture (USDA), 1:236, 2:471, 673, 3:1258 United States Department of Health and Human Services (DHHS), 1:15, 16, 31, 166, 168, 180, 2:491–492 United States Department of Homeland Security (DHS), 1:33 United States Department of Toxic Substance Control (DTSC), 1:33
United States National Institute of Allergy and Infectious Diseases (NIAID), 2:611, 3:1181– 1182, 4:1757–1758 United States National Institutes of Health (NIH), 1:32, 33, 65, 72, 107, 191, 3:1197–1199 United States Occupational Safety and Health Administration (OSHA), 1:166, 167, 235, 3:1145, 1276–1277, 4:1510 United States Pharmacopeia and National Formulary (USP-NF), 4:1710–1711 United States Public Health Service, 4:1711– 1712 universal donor, 4:1719–1720 unsaturated fats, 4:1720–1721
United States Department of Veteran Affairs, 3:1144
unstable angina, 1:139, 140
United States Drug Enforcement Agency (DEA),
upper gastrointestinal (UGI) endoscopy, 4:1616
1:123, 2:841, 3:1119, 1420, 1421 United States Environmental Protection Agency
upper motor neurons (UMNs), 3:1029 upper respiratory infections (URIs), 1:203
(EPA), 1:33, 50, 166, 167, 2:603, 606–608,
urethritis, 4:1721
864, 3:1116, 1117, 1144, 1359, 4:1463
urge incontinence, 2:896
United States Food and Drug Administration
urinalysis, 3:972
(FDA), 1:32, 37, 82, 309, 360, 374, 2:672–
urinary incontinence, 1:261, 2:895–896
673, 701, 832, 892, 922, 3:1116, 1117, 1167,
urinary tract infections (UTIs), 1:205, 261, 3:974,
1313, 1314, 1343, 1364, 4:1510, 1676
4:1721–1722
Index
urolithiasis (stones), 3:1219
I-61
venereal diseases, 1:22, 45, 105, 115, 173, 250, 253,
urological surgeon, 4:1723
2:747–747, 765, 960, 3:1170–1171, 1351,
urologists, 4:1724
1424, 4:1533–1536, 4:1732, 1743
urology, 1:120–121
Venezuela, 2:799–800, 4:1739–1740
Uruguay, 2:799, 4:1724–1725
ventricular septal defect (VSD), 1:440, 442, 2:814
U.S. Consumer Product Safety Commission (CPSC),
vertebrae, 1:200
3:1144, 4:1510
vestibular schwannomas, 1:8
Usher, Charles, 4:1725
Vibrio cholerae, 1:204, 405
Usher Syndrome, 4:1725–1726
Vibrio parahaemolyticus, 2:674
uterine cancer, 4:1726–1728, 1729
Vietnam, 1:242, 244, 245, 4:1740–1741
uterine diseases, 4:1728–1729
Vietnam War, 1:338, 2:610
Uzbekistan, 4:1730
Vineland Adaptive Behavior Scales Survey Form, 1:191
V
violence, 1:105, 106
vaccinations/immunizations, 1:26, 393–394,
viral encephalitis, 3:1138
2:881–883, 904, 908, 3:1181, 1201–1202,
viral hemorrhagic fevers (VHFs), 2:826–827
4:1474, 1563
viral hepatitis, 3:1024–1025
Vaccina virus vaccine, 4:1563
viral infections, 4:1741–1745
vaccine-derived polioviruses (VDPV), 3:1397
viral meningitis, 3:1101–1102
vacuum aspiration, 1:2, 4
Virchow, Rudolf, 3:1053, 1346, 1451
vagal response, 2:653–654
virology, 4:1743–1745
vaginal cancer, 4:1731–1732
vision, 3:1177–1179, 1283, 1284, 4:1473–1474,
vaginal diseases, 4:1732–1735 vagotomy, 4:1616 VanHoosen, Bertha, 1:104
1487–1488, 4:1576 age-related macular degeneration (AMD) in, 1:34–35, 269, 352, 2:647, 3:1178, 4:1487
Van’t Hoff, J. H., 1:215
cataracts in, 1:268–269, 356–357, 646, 3:968
Vanuatu, 4:1735–1736
cornea/corneal diseases, 1:449–450
Varco, Richard, 4:1736–1737
diabetic eye problems of, 2:511
varicella, 1:11, 380–381, 2:882, 908, 4:1491, 1538
eye cancers in, 2:641–643
varicose veins, 2:704
eye care and health of, 2:644–645
Variola major, 4:1561–1565
glaucoma in, 2:740–741
vascular dementia, 2:484
“lazy eye” in, 1:74
vascular malformation, 1:255
low vision, 3:1032–1033
vascular thoracic outlet syndrome, 4:1659
Snellen’s chart for, 4:1576
vasculitis, 4:1737–1739
See also eyes
vasospasm, 1:139 Veldman, J. E., 3:1310
Vision 2020: The Right to Sight, 1:270, 3:1284, 1285– 1286
I-62
Index
visualization, 3:1100
Warshaw, Joseph, 4:1755–1756
vitamin A, 1:269, 3:1076, 4:1488, 1745–1746,
washing, 2:872–873
1747–1748
Washington, George, 3:1308
vitamin B, 4:1748
water pollution, 3:1394
vitamin B1, 4:1748
Watson, James, 1:456, 3:1283, 4:1756–1757
vitamin B3, 4:1748
Watson-Crick base pair, 1:213
vitamin B12, 4:1748
Wechsler Intelligence Scales, 2:499
vitamin B2, 4:1748
Watson, John B., 3:1440
vitamin B6, 4:1748
Webber, Anthony Lloyd, 1:221
vitamin C, 1:435–436, 4:1748–1749
Weed, Samuel, 1:404
vitamin D, 1:279, 4:1496–1497, 1629, 1700–1701, 1749
Wegener’s granulomatosis, 4:1738
vitamin E, 4:1749
weight control, 1:106–107
vitamin K, 1:265, 266, 4:1749
Weinberg, Robert, 3:1283
vitamins and minerals, 4:1746–1749
Weinberg Progression Model, 1:10, 4:1583
vitiligo, 3:1183, 4:1551, 1554, 1749–1750
Wentworth, Paul, Jr., 3:1316
Vocational Rehabilitation Act, 1:183
Werdnig-Hoffman disease, 4:1596
voice disorders, 4:1589, 1751–1752
Wernicke’s aphasia, 1:155
Voluntary Euthanasia Society (VES), 4:1752–1753
Wernicke’s encephalopathy (WE), 1:57
vomiting, 3:1210–1212
Western Sahara, 4:1758–1759
von Euler, Ulf, 1:197
West Nile virus, 3:1138, 4:1757–1758
Von Graefe, Albrecht, 4:1725
wet beriberi, 1:224
von Recklinghausen disease, 3:1225
Wetherill, Charles M., 2:672
von Willebrand disease (vWD), 1:264
Wharton’s duct, 4:1514
vulvar cancer, 2:766, 4:1753–1754
whiplash injuries, 3:1212–1213
Vygotsky, Lev, 3:1442
Whistleblower Program, 1:98 White, Ryan, 2:822, 3:1162
W
white blood cells (WBCs), 1:270–271, 281
W. K. Kellogg Foundation, 1:173
Whitten, Charles F., 4:1542
Wagner-Jauregg, Julius, 3:1053
WHO Global Database on Child Growth and
Wald, George, 2:595 Waldeyer Hartz, Heinrich Wilhelm Gottfried von, 1:406
Malnutrition, 2:756 WHO Global Strategy for the Containment of Antimicrobial Resistance, 1:148
Wall, Monroe, 3:1283
WHO Model List of Essential Drugs, 1:148
Wallace, Alfred Russell, 2:472
whooping cough (pertussis), 1:11, 149, 2:882, 908,
Walsh, Patrick, 3:1283
4:1759–1760
Wani, Mansukhal, 3:1283
Whytlaw-Gray, Robert, 4:1467
Waniek, D. A., 2:950
Wieschaus, Eric, 3:1017
Index
I-63
Wilk, Chester A., 1:404
wrist/arm injuries and disorders, 4:1768–1771
Wilkins, Lawson, 4:1761
written expression, disorders of, 3:1001
Wilkins, Maurice, 1:456, 457, 4:1756
Wundt, Wilhelm, 3:1440
Willard, Harold N., 2:934
Wyllie, Andrew H., 3:1427
Willi, Heinrich, 3:1408
Wynder, Ernst Ludwig, 3:1283
William, Montel, 3:1147 William IV, 1:220
X
Williams-Steiger Act, 3:1277
xenobiotics, 4:1673
Willis, Thomas, 3:1231
xenografts, 1:63
Wilson, Christopher Wilson, 2:786
X-linked diseases, 2:825
Wilson, Robert A., 3:1105
X-linked severe immunodeficiency (SXCID), 2:715–
Wilson, Samuel, 4:1761 Wilson’s Disease (WD), 4:1761–1763
716 X-rays, 2:516, 4:1612
WISEWOMAN, 3:1166 withdrawal, from caffeine, 1:329
Y
Withers, H. Rodney, 3:1283
YAG (yttrium-aluminum-garnet) laser, 3:1285
Wolf, Caspar, 3:1269
Yalow, Rosalyn S., 2:601
Wolman’s disease, 3:1119
yeasts/yeast infections, 1:42, 2:690–692, 729, 3:1057,
women’s health, 1:88, 102, 3:1203–1204, 1256, 4:1763–1766
4:1734–1735 yellow fever, 2:882, 3:1138, 1202, 4:1584
Women’s Health Initiative (WHI), 3:1256
Yemen, 4:1773–1774
women’s movement, 2:736–737
Yersinia pestis, 1:232
workplace safety, 3:1191–1192
YLF (yttrium-lithium-fluoride) laser, 3:1285
World Bank, 1:412
Young, James, 3:1269
World Food Day, 1:114
Y-shaped antibodies, 1:9, 2:879
World Health Organization (WHO), 1:12, 26, 27, 36, 45, 134, 147, 148, 187, 232, 235, 239, 243,
Z
245, 268, 270, 307, 337, 385, 394, 405, 416,
Zaltzman, Perola, 3:1242
2:502, 504, 509, 522, 609, 644, 676–677, 931,
Zambia, 4:1775–1776
941, 3:1051, 1143, 1215, 1285, 1452, 4:1478,
Zhang, Yawei, 2:771
1533, 1562, 1569, 1675, 1678, 1679, 1685,
Zidovudine (AZT), 1:43
1747, 1766–1768
Ziegler, Andrew, 3:1408
World Organization for Animal Health (OIE), 1:244–245
Zimbabwe, 4:1776–1777 zinc, 4:1749
World Trade Organization (WHO), 3:1361
Zoll, Paul, 4:1777
worms, 2:944–945, 3:1083–1084, 1335
Zondek, Bernhard, 2:601
Wright, Sewell, 1:422
zoonisis, 1:371
I-64
Photo Credits
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