Parasitic. Abstract. Entamoeba histolytica. Introduction
|
|
- Everett Small
- 6 years ago
- Views:
Transcription
1 PNEUMONIA / Parasitic 447 Parasitic T B Nutman and K R Talaat, National Institutes of Health, Bethesda, MD, USA & 2006 Elsevier Ltd. All rights reserved. Abstract Parasites are eukaryotic organisms that live within another organism or host. They are broadly divided into two groups: single-celled protozoa and multicellular helminths. Most parasites have complex life cycles with multiple stages, often requiring multiple host species to complete their life cycle. Humans acquire infection with parasitic organisms in a number of different ways. Some are ingested through a fecal-oral spread, others transmitted by insect vectors, still others by penetrating through the skin of the host from contaminated soil or water. This article focuses on the major parasitic infections that affect the lungs. Few parasites specifically go to the lungs as their final target organ, with the exception of Paragonimus, the lung fluke. For the majority of the organisms that cause pulmonary disease, either the lungs are secondary sites of infection (e.g., amebiasis and toxoplasmosis), or the parasites migrate through the lung en route to another organ system (e.g., Strongyloides, Ascaris). In some infections, pulmonary symptoms are due to a hypersensitivity immune response to parasite antigen as seen in the tropical pulmonary eosinophilia syndrome. Introduction Parasites are eukaryotic organisms that live within another organism or host. They are broadly divided into two groups: single-celled protozoa and multicellular helminths. Whereas protozoa are often intracellular, helminths are characteristically extracellular. Most parasites have complex life cycles with multiple stages, often requiring multiple host species to complete their life cycle. These host species could be another mammal (e.g., dogs and sheep for Echinococcus), an invertebrate host (crustaceans for Paragonimus sp.), or an insect vector such as Anopheline mosquitoes for the malaria parasites. For most of the infections being described in this article, humans are the definitive hosts (in which the adult or sexual stage (if there is one) is found). For other infections, humans are the intermediate hosts or the incidental dead-end hosts of a parasite that usually infects other species (e.g., Toxocara). Infection with parasitic organisms is acquired in a number of different ways. Some are ingested and are spread person to person or through fecal/oral or fecal/soil/oral transmission (i.e., Ascaris). Others require an insect vector for transmission. Still others have intermediate species in which they complete part of their life cycles. Some organisms can enter from a contaminated environment by penetrating the skin (e.g., Strongyloides, hookworm). Some of these organisms have worldwide distribution (e.g., Ascaris, Toxoplasma), but most have geographic foci of endemicity. Often, these foci are in regions of the world with limited resources and where free and easy access to clean water and sanitation is not available. In industrialized countries, these infections are most commonly encountered in immigrants or returning travelers. Once thought exotic, parasitic diseases account for an increasing presence in industrialized countries because of returning travelers, immigration, and mass movements of people as a result of political or socioeconomic upheavals. An awareness of the clinical manifestations and management of these diseases is therefore crucial for both primary care physicians and specialists. By no means comprehensive, this article will briefly examine those parasites most likely to cause pulmonary disease. Entamoeba histolytica Entamoeba histolytica, the causative organism of amebiasis, is a ubiquitous protozoan. It is more common in developing countries, especially in areas of low socioeconomic resources where access to adequate sanitation is not available. Cysts are ingested in fecally contaminated food and water. Excystation occurs in the small intestine, where the larvae divide into trophozoites that migrate from the intestine to the liver through the portal circulation. The clinical spectrum of E. histolytica infection is very broad. Only about 10% of people infected with E. histolytica develop disease; others can spontaneously clear their asymptomatic infection within 1 year of infection. The most common site for extraintestinal infection with E. histolytica is the liver. Liver disease occurs in 3 9% of cases of amebiasis. Lung disease occurs in 2 7% of those with invasive amebiasis. Most commonly, lung disease develops from extension of a liver abscess. It occurs by direct extension, insidiously from the liver through the diaphragm; by rupture, involving the pleura (leading to pleurisy, effusion, or empyema); or with development of pulmonary consolidation, lung abscess, or bronchohepatic fistula. Up to 40% of patients with liver abscess develop pulmonary complications. The most common is reactive pleuritis secondary to the hepatic abscess. Clinically, patients can complain of right upper quadrant pain with pleuritic chest pain. They frequently have normal liver enzymes. A pleural rub is common in patients with amoebic liver abscess. The fluid in the pleural space is exudative and sterile. If the abscess extends into the pleural cavity, an amoebic empyema can form. The onset of this can be insidious or acute.
2 448 PNEUMONIA / Parasitic Patients have fever, right upper quadrant and chest pain, and a dry cough. Rupture into the pleural cavity is often signaled by abrupt exacerbation of pain with rapidly progressive respiratory distress, possibly sepsis and shock. If invasion into a major bronchus occurs, hemoptysis can develop containing the anchovy paste-like pus coming from the amoebic abscess. Physical examination findings of amoebic lung disease often include hepatic enlargement and tenderness, dullness to percussion at the right base with decreased or absent breath sounds, and a pleural rub with occasional crepitation. If the lung disease is chronic, cachexia and clubbing can sometimes be found. Chest X-ray abnormalities occurred in 57% of patients with amoebic liver disease. Untreated, the mortality of invasive amebiasis is over 80%. The diagnosis of invasive amebiasis is made by identifying the organism, by serology or by polymerase chain reaction (PCR). Treatment is with metronidazole and paromomycin or dioxanide furoate. Toxoplasma gondii Toxoplasma gondii is an obligate intracellular parasite in which humans are the incidental host. It is most frequently acquired by ingestion of cysts excreted in cat feces. Once inside the host, the organism can invade any cell of the body, most commonly the brain, lymph node, heart, and lung. The vast majority of immunocompetent persons who are infected is clinically asymptomatic. Immunosuppressed individuals can have more fulminant toxoplasmosis, either during primary infection or with reactivation of latent infection. In the lung, T. gondii infection can cause a necrotizing pneumonia with nodule formation, diffuse alveolar damage, and interstitial pneumonitis. Edema develops in the alveolar capillary interface with lymphocytic infiltration. AIDS patients with Toxoplasma pneumonia present with cough, dyspnea, and fever. Toxoplasmosis is diagnosed by serology or by identifying tachyzoites in bronchioalveolar lavage (BAL) smears. Pyrimethamine with folinic acid and sulfadiazine is the treatment of choice for Toxoplasma pneumonia. Paragonimus Few helminths specifically go to the lungs as their final target organ, the notable exception being Paragonimus, or the lung fluke. Found throughout the world, but primarily in Asia, paragonimiasis is acquired by ingestion of raw, undercooked or pickled crabs or other crustaceans. Once ingested the larvae penetrate through the intestines and migrate through the diaphragm and pleura into the lungs. There, worm pairs encyst together near bronchial passages and mature into adult worms that lay eggs. Paragonimiasis is rarely a serious or fatal infection. The symptoms depend on the location of the worms and their developmental stage. Shortly after infection, patients may complain of diarrhea or abdominal pain or discomfort, although most people are asymptomatic initially. The initial penetration of the larvae through the diaphragm and pleura can cause pleuritic chest pain and pneumothoraces. Symptoms of paragonimiasis include cough, hemoptysis, and chest pain. The hemoptysis is usually of rusty or chocolate sputum; large amounts of frank bright red blood are unusual. Pleural effusions can form and, if large, can result in dyspnea. Chronic infection is often mistaken for tuberculosis, especially in areas where paragonimiasis is less prevalent; however, in some instances, tuberculosis and paragonimiasis can coexist. The physical exam is usually normal, although rales may be heard. Rarely, clubbing of the fingers is seen. Radiographically, nodules, pneumothoraces and interstitial infiltrates, effusions, cavities, or ring cysts resembling bronchiectasis can be seen. Parenchymal consolidation is seen in the majority of patients. The infiltrates can be transient, especially in acute infection as the worms migrate. CT can show the migration tracks of the worms as linear opacities and later as cysts within the parenchymal consolidations (see Figure 1). The chest X-ray can be normal in 10 20% of cases. Once suspicion of paragonimiasis has been aroused by a history of handling or eating freshwater crabs or crayfish, isolating Paragonimus eggs in the sputum or stool make the diagnosis. Treatment is with praziquantel. Intestinal Roundworms: Ascaris, hookworm, Strongyloides Roundworms or nematodes can be classified broadly into those inhabiting the intestine, which are by far the most common, and those infecting deep tissue. It is estimated that there are more than 1 billion cases of ascariasis worldwide. With the exception of Strongyloides stercoralis, intestinal nematodes do not multiply within humans, and finding either eggs or parasites, usually in the stool, makes the diagnosis. Strongyloides, through its autoinfection cycle, can multiply and disseminate widely in an immunocompromised individual (hyperinfection syndrome). Pulmonary disease in intestinal helminth infections is relatively uncommon but can occur during the stage of larval migration through the lungs en route to the intestine. When apparent in immunocompetent hosts, pulmonary disease usually occurs as
3 PNEUMONIA / Parasitic 449 Figure 1 Computed tomography image of Paragonimus westermani infection in a 46 year Korean man showing a cystic lesion within an infiltrate. The patient also developed a pulmonary effusion. Courtesy of Myoung-don Oh, Seoul National University College of Medicine, South Korea. a Loeffler s syndrome with cough, asthma, fever, patchy pulmonary infiltrates on chest radiographs, and eosinophilia. Ascaris, hookworm, and Strongyloides are the most common causes of this syndrome among the intestinal helminths. Ascariasis is the most common cause worldwide of transient eosinophilic pulmonary infiltrates. In some areas, the pneumonitis occurs at specific times of the year depending on the climate. Infection is acquired by ingestion of eggs on contaminated foods or from soil. Symptoms develop 9 12 days after ingestion of the eggs and can last from 2 to 3 weeks. Larval migration through the lungs leads to pneumonitis, which can manifest as a nonproductive cough, asthma, burning substernal pain that is pleuritic in nature, dyspnea, and occasionally mild hemoptysis, rales, or wheezes. These may be associated with an urticarial rash or low-grade fever. Rarely, an adult worm can ectopically migrate into the lungs or other viscera and get lost. Human hookworm disease is caused primarily by either Ancylostoma duodenale or Necator americanus. Larvae enter the skin and then migrate to the lungs. From there, they crawl up the bronchial tree to the epiglottis, where they are swallowed. Once in the small intestine, the adult worm develops and starts shedding eggs. The migration of the larvae through the lungs may cause a Loeffler s syndrome similar to that in ascariasis. Patients may have a mild cough, or the symptoms may be more severe, with associated dyspnea and wheezing. Symptoms generally last B2 weeks; in heavy infections, they can last up to 3 months. Chest X-ray can show transient, migratory opacities, especially in the hilar areas, with spontaneous clearing. Strongyloides infection is also acquired when larvae penetrate through skin on contact with fecally contaminated soil or water. In strongyloidiasis, the pulmonary symptoms are predominantly cough, dyspnea, and bronchospasm during the migratory phase, although persistent asthma due to Strongyloides infection has been reported. Patients with chronic lung disease may retain the larvae in the lungs, where they molt into adults and complete their entire life cycle, leading to worsening lung disease with chronic cough and bronchospasm. In disseminated disease, intense worm burdens or inflammatory response can cause acute respiratory distress syndrome (ARDS), alveolar hemorrhage, or bacterial superinfection of the lungs. During the initial, pulmonary phase of infection, intestinal roundworm infections are difficult to diagnose. Once the mature worms have started shedding eggs in the intestines, these eggs (for Ascaris and hookworm), or larvae (for Strongyloides), can be identified in the stool. Anthelmintic treatment of intestinal infections probably has no effect on larval stages in the lungs; however, pulmonary disease is usually self-limited and does not require specific treatment, except for symptomatic relief. To treat intestinal disease, albendazole or mebendazole can be used for ascariasis and hookworm, and ivermectin is the treatment of choice for strongyloidiasis. Lymphatic Filariasis Filariae are a family of tissue-dwelling roundworms that infect adults in the tropics and subtropics. The major pulmonary manifestation of these organisms is tropical pulmonary eosinophilia (TPE) seen in
4 450 PNEUMONIA / Parasitic infection with the lymphatic filariae, Wuchereria bancrofti and Brugia malayi. TPE is felt to be secondary to increased immune responsiveness to the parasites, and is really a systemic syndrome, with the pulmonary component being the most significant. Initially, patients complain of vague systemic symptoms, including low-grade fevers and myalgias. Then pulmonary symptoms start, and these include cough (which can be paroxysmal) and wheezing, both being worse at night, dyspnea, and occasionally chest pain. This can often be mistaken for asthma, and patients may be incorrectly treated for more common disorders. Pulmonary function is abnormal in these patients. As the disease progresses, the symptoms can spontaneously remit and recur and gradually worsen, with a decrease in the wheezing but an increase in dyspnea. This eventually leads to chronic lung disease with dyspnea and hypoxia at rest, which in later stages is indistinguishable from any cause of interstitial pulmonary fibrosis. Rarely, TPE can present as cor pulmonale. The diagnosis of TPE requires that a patient meets both clinical and laboratory criteria with marked elevations of peripheral eosinophil and IgE levels. Most patients respond dramatically to treatment with diethylcarbamazine. Toxocara Visceral larva migrans (VLM) or toxocariasis is a zoonotic infection usually caused by dog or cat ascarids of the Toxocara genus. The eggs are ingested and then hatch into larvae, which penetrate the intestine and start migrating. Because humans are not the definitive host, the larvae cannot mature, and so continue migrating for months or years. Most people who are infected with Toxocara spp. are asymptomatic. Symptoms depend on the extent and frequency of infection, the distribution of larvae in tissues, and the inflammatory response of the host. There are two clinical syndromes of infection: VLM and ocular larval migrans (OLM). The symptoms of VLM are related to the organ invaded, most commonly the liver, lung, or other thoracic or abdominal organ. VLM usually affects children o5 years old, although it can affect adults. In children with VLM 33 86% had pulmonary symptoms: most commonly, chronic cough, which may be paroxysmal and worse at night, wheezing, and pulmonary infiltrates. On exam, 65% had hepatomegaly, 43% had an abnormal lung exam (wheezes or rales). VLM is diagnosed by serology and treated with albendazole. Echinococcus Humans can develop lung disease after being incidentally infected with Echinococcus sp., which are usually parasites of canines, sheep, and other domestic ungulates. Infection with Echinococcus is always asymptomatic for months to decades. Cysts are commonly found when symptoms develop or on routine or screening imaging. Symptoms develop because of one or more of three processes: (1) mechanical pressure or deformation of tissues, or nearby vascular structures; (2) rupture or leakage of the cyst; or (3) superinfection. The liver is the organ most commonly affected in 60% of cases, and the lungs are affected in 20 30% of cases. Pulmonary symptoms have been reported in 67 89% of patients with lung cysts. Most commonly, symptoms are cough, fever, and chest pain. Occasionally, hemoptysis can occur, and rarely, biliptysis, pneumothorax, or pleuritis. With rupture of the cyst into a bronchus, hydatid vomica of cystic contents can occur: clear, salty/peppery fluid with or without hemoptysis. The fluid can be purulent if superinfected. With dissemination of the antigenic fluid, respiratory failure or anaphylaxis can occur. One-third of diagnosed cases of pulmonary hydatid cyst show ruptured or infected cysts. Diagnosis is made by clinical history and radiologic findings. Early surgical intervention promptly after diagnosis can help prevent complications. Perioperatively, or for unresectable lesions, medical therapy with anthelmintics (albendazole) should also be used. See also: Allergy: Allergic Reactions. Asthma: Overview. Human Immunodeficiency Virus. Leukocytes: Eosinophils. Pneumonia: Overview and Epidemiology; The Immunocompromised Host. Systemic Disease: Eosinophilic Lung Diseases. Further Reading Chu E, Whitlock WL, and Dietrich RA (1990) Pulmonary hyperinfection syndrome with Strongyloides stercoralis. Chest 97: DeFrain M and Hooker R (2002) North American paragonimiasis: case report of a severe clinical infection. Chest 121(4): Dogan R, Yuksel M, Cetin G, et al. (1989) Surgical treatment of hydatid cysts of the lung: report on 1055 patients. Thorax 44(3): Gottstein B and Reichen J (2002) Hydatid lung disease (echinococcosis/hydatidosis). Clinics in Chest Medicine 23(2): ix. Huntley CC, Costas MC, and Lyerly A (1965) Visceral larva migrans syndrome: clinical characteristics and immunologic studies in 51 patients. Pediatrics 36: Ibarra-Perez C (1981) Thoracic complications of amebic abscess of the liver. Report of 501 cases. Chest 79: Mandell GL, Bennett JE, and Dolin R (eds.) (2000) Principles and Practice of Infectious Diseases, 5th edn. Philadelphia: Churchill Livingstone. Meehan AM, Virk A, Swanson K, and Poeschla EM (2002) Severe pleuropulmonary paragonimiasis 8 years after emigration from
5 PNEUMONIA / Mycobacterial 451 a region of endemicity. Clinical Infectious Diseases 35(1): O Lorcain P and Holland CV (2000) The public health importance of Ascaris lumbricoides. Parasitology 121(supplement): S51 S71. Ottesen EA and Nutman TB (1992) Tropical pulmonary eosinophilia. Annual Review of Medicine 43: Sarinas PSA and Chitkara RK (1997) Ascariasis and hookworm. Seminars in Respiratory Infections 12(2): Shamsuzzaman SM and Hashiguchi Y (2002) Thoracic amebiasis. Clinics in Chest Medicine 23(2): Stanley SL Jr (2003) Amoebiasis. Lancet 361(9362): Talaat KR and Nutman TB (2005) Parasitic infections. In: Murray JF, Nadel JA, Mason RJ, and Broaddus VC (eds.) Textbook of Respiratory Medicine, 4th edn. Philadelphia: Elsevier. Tor M, Atasalihi A, Altunas N, et al. (2000) Review of cases with cystic hydatid lung disease in a tertiary referral hospital located in an endemic region: a 10 years experience. Respiration 67(5): Mycobacterial N W Schluger, Columbia University College of Physicians and Surgeons, New York, NY, USA J Burzynski, New York City Department of Health, New York, NY, USA & 2006 Elsevier Ltd. All rights reserved. Abstract Tuberculosis has probably been the cause of more deaths than any other infectious disease. Although the disease is almost always treatable with a handful of antibiotics taken once a day, it continues to cause tremendous suffering and is a leading cause of death. Despite the recent attention and efforts at control in the short term, rates are likely to increase. In many parts of the world, current tuberculosis control programs are ineffective and the number of tuberculosis cases is rising. A program of directly observed therapy short (DOTS) course has been widely accepted as a standard of care but less than half of all persons with tuberculosis receive treatment with directly observed therapy. In many countries with high disease burden, coinfection with human immunodeficiency virus (HIV) has contributed to increasing rates of tuberculosis. Tuberculosis is the leading cause of death from an opportunistic infection in persons with acquired immunodeficiency syndrome (AIDS) worldwide. Epidemiology One-third of the world s population is infected with tuberculosis and infection leads to over eight million cases of active disease and two million deaths per year. Case rates of active disease vary greatly by geographic region and by country and are influenced by many factors including varying case definitions and completeness of reporting. The highest incidence rates are in sub-saharan Africa; China and India have the highest number of total cases. Case rates in the US and Western Europe trended downwards for most of the twentieth century and are currently at the lowest rate in recorded history. A thorough understanding of the epidemiology of tuberculosis is essential in establishing effective public health control measures. Clinicians understanding of the epidemiology and the ability to suspect and establish the diagnosis is heavily influenced by an understanding of a patient s epidemiologic risk factors. Case rates are highest in young adults as a result of increased social interaction and an initial opportunity for exposure to someone else with an infectious form of the disease. At the extremes of age, young children and the elderly are also especially prone to developing active disease. Children who are infected after an exposure to an active case have a much higher rate of progression to active disease. While overall, 5 10% of infected contacts progress to active disease after an exposure to an active case, 43% of infants under 1 year of age and 24% of children 1 5 years old develop active disease after recent infection. The elderly have a higher case rate as a result of reactivation disease. With the advances of age, a weakened immune system can no longer control dormant bacteria from a previous infection and active disease develops. In low incidence countries like the US and most of the countries of Western Europe, tuberculosis cases are more common in men than in women but now in some countries with high rates of HIV infection, tuberculosis case rates are higher in women than in men. Certain host characteristics are associated with disease progression. Clinicians have long noticed more cases of pulmonary disease associated with tall, lean persons. Poor nutrition and being underweight are also risk factors. Certain medical conditions in the host are associated with an increased risk of tuberculosis disease, including HIV infection, diabetes mellitus (particularly when poorly controlled), end-stage renal disease, and silicosis. These conditions that have an effect on the response of the immune system all have well-documented associations with active tuberculosis disease. The use of certain medications that affect host defenses including corticosteroids, blockers of tumor necrosis factor (TNF), and immunosuppressive medications used for patients with organ transplantation also pose significant risks for developing active tuberculosis. Nothing has had more impact on tuberculosis epidemiology than HIV. HIV coinfection is the greatest risk factor for reactivation of latent infection into clinical tuberculosis disease. HIV-positive persons
Parasitic Protozoa, Helminths, and Arthropod Vectors
PowerPoint Lecture Slides for MICROBIOLOGY ROBERT W. BAUMAN Chapter 23 Parasitic Protozoa, Helminths, and Arthropod Vectors Helminthic Parasites of Humans Helminths are macroscopic, multicellular, eukaryotic
More informationParasites List of Pinworm (Enterobius vermicularis) Giardia ( Giardia lamblia Coccidia ( Cryptosporidium
Parasites List of Pinworm (Enterobius vermicularis) Pinworm, also known as seatworm or threadworm, is one of the most prevalent intestinal parasites in the United States, with approximately 40 million
More informationEosinophilic lung diseases
Eosinophilic lung diseases Chai Gin Tsen Department of Respiratory and Critical Care Medicine Tan Tock Seng Hospital The eyes do not see what the mind does not know Not very common A high index of suspicion
More informationParasitology Questions. Choose the best correct answer in the following statements
Parasitology Questions Choose the best correct answer in the following statements ١. A.. is the larval stage of a fluke that is covered with cilia and swims about seeking out a snail to serve as an intermediate
More information1.Nematodes. Parasitology/Helminths
1.Nematodes Parasitology/Helminths Helminths all helminths are relatively large (> 1 mm long); some are very large (> 1 m long). all have well-developed organ systems and most are active feeders. the body
More informationNematodes (roundworms)
Intestinal human nematodes Dr Mohammed Abdulla FIBMS (general medicine), FIBMS (G&H), MRCP SCE (G&H). Medically-important nematodes Nematodes (roundworms) There are >60 species of nematodes (roundworms)
More informationPARASITOLOGY CASE HISTORY #82 (Lynne S. Garcia)
PARASITOLOGY CASE HISTORY #82 (Lynne S. Garcia) ***Reminder: Slides are copyrighted and cannot be copied for publication. A 57 year old male was seen at a local clinic with a year-long history of productive
More information8/11/16. Kevin Letz DNP, MSN, MBA, RN, CEN, CNE, FNP-C, PCPNP-BC, ANP-BC, FAANP
Kevin Letz DNP, MSN, MBA, RN, CEN, CNE, FNP-C, PCPNP-BC, ANP-BC, FAANP Eosinophilia Eosinophilia refers to an absolute eosinophil count in the peripheral blood of 500 eosinophils/microl; this is considered
More informationParagonimiasis added Jan 2016
added Jan 2016 BASIC EPIDEMIOLOGY Infectious Agent Paragonimus species, a parasitic lung fluke (flat worm). More than 30 species of trematodes (flukes) of the genus Paragonimus have been reported which
More informationEDO UNIVERSITY IYAMHO
EDO UNIVERSITY IYAMHO FACULTY OF SCIENCE SEMINAR SERIES INTESTINAL HELMINTHIASIS: SOIL TRANSMITTED INFECTIONS. PRESENTED BY Mrs. Habibat Joy, Ozemoka 3rd August, 2018 INTRODUCTION Intestinal helminthiasis
More informationHelminths (Worms) General Characteristics: Eukaryotic, multicellular parasites, in the kingdom Animalia.
Parasite II Helminths (Worms) General Characteristics: Eukaryotic, multicellular parasites, in the kingdom Animalia. They are worm-like organisms that live and feed off living hosts, receiving nourishment
More informationStrongyloidesstercoralisstercoralis
Strongyloides: What you always wanted with breakfast { Global to Local lecture series: Parasitic infections 73 yocambodian Male Former truck driver 15 pack-year h/o smoking; quit 1989 Hospitalized April
More informationRoberto Barrios Abida K. Haque Editors. Parasitic Diseases of the Lungs
Roberto Barrios Abida K. Haque Editors Parasitic Diseases of the Lungs 123 Parasitic Diseases of the Lungs Roberto Barrios Abida K. Haque Editors Parasitic Diseases of the Lungs Editors Roberto Barrios
More informationL:7, L:8 Parasitology
L:7, L:8 Parasitology 2.Fasciola hepatica Adult The adult Fasciola hepatica worm is flattened, leaf like shape, equipped with shoulders, somewhat oblong. Adult Fasciola hepatica measuring 3cm by 1cm in
More informationAscaris lumbricoides
Case History A 4-year-old Caucasian male child of Turkish nationality was admitted to the emergency department with Abdominal pain and biliary vomiting for three days. Physical Examination revealed abdomen
More informationProtozoans and Helminthes
Protozoans and Helminthes 1 Protozoans 2 3 4 5 6 Worm: Leishmania donovani General Family: Trypanosomes (Blood/tissue flagellates) Larvae or Adult Sketch of dermal, post-visceral kala-azar Life Cycle:
More informationImmunological Aspects of Parasitic Diseases in Immunocompromised Individuals. Taniawati Supali. Department of Parasitology
Immunological Aspects of Parasitic Diseases in Immunocompromised Individuals Taniawati Supali Department of Parasitology 1 Defense mechanism in human Th17 (? ) Acute Chronic Th1 Th 2 Intracellular Treg
More informationLecture-7- Hazem Al-Khafaji 2016
TOXOPLASMOSIS Lecture-7- Hazem Al-Khafaji 2016 TOXOPLASMOSIS It is a disease caused by Toxoplasma gondii which is a protozoan parasite that is infects a variety of mammals and birds throughout the world.
More informationPOSTGRADUATE INSTITUTE OF MEDICINE UNIVERSITY OF COLOMBO MD (MEDICAL PARASITOLOGY) EXAMINATION JANUARY, 2001 PAPER 1
JANUARY, 2001 Date: 15 th January 2001 Time: 2.00 p.m. -500 p.m. PAPER 1 Answer all five (5) questions Answer each question in a separate book 1. Discuss the underlying principles relating to the use of
More informationGiardia lamblia (flagellates)
Giardia lamblia (flagellates) Dr. Hala Al Daghistani Giardia lamblia (Giardia duodenalis or Giardia intestinalis) is the causative agent of giardiasis and is the only common pathogenic protozoan found
More informationEx. Schistosoma species (blood flukes) and Fasciola hepatica.
TREMATODES: INTRODUCTION: Ex. Schistosoma species (blood flukes) and Fasciola hepatica. The life cycle of trematodes involves a sexual cycle in humans and asexual reproduction in freshwater snails (intermediate
More informationWelcome to Parasitic. Fall 2008
Welcome to Parasitic Diseases Fall 2008 Dickson Despommier, Ph.D. Charles Knirsch, MPH, MD Josh Stillman, MD Parasite Any organism that takes metabolic advantage of another organism Viruses Rickettsiae
More informationIntroduction to Parasitic Helminths
Introduction to Parasitic Helminths Lecture 4 Medical Parasitology Course (MLAB 362) Dr. Mohamed A. El-Sakhawy 1 Parasitic Helminths Eukaryotic, multicellular animals that usually have digestive, circulatory,
More informationSigns and Symptoms of Parasitic Diseases
Signs and Symptoms of Parasitic Diseases Abdominal pain Entamoeba histolytica (amebic colitis, liver infection) Giardia lamblia Cryptosporidium Intestinal helminths (Ascaris, Strongyloides) Anisakis (symptoms
More informationPediatric emergency medicine in Laos when horses turn to zebras
Pediatric emergency medicine in Laos when horses turn to zebras "When you hear hoofbeats, think of horses not zebras Capital: Vientiane Currency: Lao kip Population: 6.77 million (2013) Official language:
More informationPULMONARY TUBERCULOSIS RADIOLOGY
PULMONARY TUBERCULOSIS RADIOLOGY RADIOLOGICAL MODALITIES Medical radiophotography Radiography Fluoroscopy Linear (conventional) tomography Computed tomography Pulmonary angiography, bronchography Ultrasonography,
More informationPathology of pulmonary tuberculosis. Dr: Salah Ahmed
Pathology of pulmonary tuberculosis Dr: Salah Ahmed Is a chronic granulomatous disease, caused by Mycobacterium tuberculosis (hominis) Usually it involves lungs but may affect any organ or tissue Transmission:
More informationUnit II Problem 2 Pathology: Pneumonia
Unit II Problem 2 Pathology: Pneumonia - Definition: pneumonia is the infection of lung parenchyma which occurs especially when normal defenses are impaired such as: Cough reflex. Damage of cilia in respiratory
More informationCase Report Primary Pulmonary Amebiasis Complicated with Multicystic Empyema
Case Reports in Pulmonology Volume 2016, Article ID 8709347, 4 pages http://dx.doi.org/10.1155/2016/8709347 Case Report Primary Pulmonary Amebiasis Complicated with Multicystic Empyema Ali Zakaria, Bayan
More informationBacillary Dysentery (Shigellosis)
Bacillary Dysentery (Shigellosis) An acute bacterial disease involving the large and distal small intestine, caused by the bacteria of the genus shigella. Infectious agent Shigella is comprised of four
More informationCoccidia. Eucoccidioside
Coccidia Kingdom Sub-Kingdom Phylum Class Order Family Genus Species Protista Protozoa Apicomplexa Sporozoasida Eucoccidioside Sarcocystidae Toxoplasma gondii 1 Toxoplasma gondii (life cycle) Sexual cycle
More informationAscariasis rev Jan 2018
rev Jan 2018 BASIC EPIDEMIOLOGY Infectious Agent is caused by the soil transmitted helminths Ascaris lumbricoides and Ascaris suum. Both are roundworm intestinal nematodes. Ascaris lumbricoides is found
More informationTB Intensive Houston, Texas
TB Intensive Houston, Texas October 15-17, 17 2013 Diagnosis of TB: Radiology Rosa M Estrada-Y-Martin, MD MSc FCCP October 16, 2013 Rosa M Estrada-Y-Martin, MD MSc FCCP, has the following disclosures to
More informationComplicated echinococcal cyst to Biopsy or not to biopsy. V. Rusanov MR Kramer Pulmonary Institute, Rabin medical center
Complicated echinococcal cyst to Biopsy or not to biopsy V. Rusanov MR Kramer Pulmonary Institute, Rabin medical center Case 1 84 y.o. Male, Iraq descend, past smoker 40 PY Medical History- HTN, Rheumatoid
More informationHelminths in tropical regions
Helminths in tropical regions Schistosoma spp. Blood flukes Schistosomiasis is one of the most widespread parasitic infections in humans Humans are the principal hosts for: Schistosoma mansoni, Schistosoma
More informationOnly one take home point for the talk 9/26/2018. Infectious Diseases and Donor Derived Infections. Don t forget about donor-derived infections
Shane Colombo 1993 2018 Infectious Diseases and Donor Derived Infections Peter Chin-Hong, MD Division of Infectious Diseases UCSF Only one take home point for the talk Don t forget about donor-derived
More informationTROPICAL AND SUBTROPICAL PARASITIC INFECTIONS OF THE CHEST: A GUIDE FOR RADIOLOGISTS
TROPICAL AND SUBTROPICAL PARASITIC INFECTIONS OF THE CHEST: A GUIDE FOR RADIOLOGISTS GSP Meirelles, J Capobianco, D Jasinowodolinski, D Escuissato, C Araujo Neto, B Hochhegger, A Soares Souza Jr, E Marchiori
More informationSchistosome life cycle.
Schistosomiasis infects approximately 200 million persons and kills approximately 280,000 annually. Most of the mortality comes from hepatic granulomas and fibrosis Schistosoma japonicum and Schistosoma
More information1. Parasitology Protozoa 4
Contents 1. Parasitology 1 Host Parasite Relationship 2 Mode of Transmission 2 2. Protozoa 4 Classification 4 Reproduction 5 Immunity 5 Pathogenesis 6 Laboratory Diagnosis 6 Treatment 8 Entamoeba 8 Classification
More informationThe Missing Piece. Kathryn B. Robertson, M.D., William J. Janssen, M.D., Sanjay Saint, M.D., M.P.H., and Steven E. Weinberger, M.D.
The new england journal of medicine clinical problem-solving The Missing Piece Kathryn B. Robertson, M.D., William J. Janssen, M.D., Sanjay Saint, M.D., M.P.H., and Steven E. Weinberger, M.D. In this Journal
More informationTuberculosis: The Essentials
Tuberculosis: The Essentials Kendra L. Fisher, MD, PhD THORACIC TUBERCULOSIS: THE BARE ESSENTIALS Kendra Fisher MD, FRCP (C) Department of Radiology Loma Linda University Medical Center TUBERCULOSIS ()
More informationNEW YORK STATE Parasitology Proficiency Testing Program. Parasitology (General) 01 February Sample Preparation and Quality Control
NEW YORK STATE Parasitology Proficiency Testing Program Parasitology (General) 01 February 2011 The purpose of the New York State Proficiency Testing Program in the category of Parasitology (General) is
More informationNEGLECTED DISEASES. Elsa Herdiana Murhandarwati Dept. Parasitologi 2017
NEGLECTED DISEASES Elsa Herdiana Murhandarwati Dept. Parasitologi 2017 2 3 Taeniasis 4 Survives for years Take 2 months to become adult survives for years days to months in environment Life cycle image
More informationToxoplasma gondii. Definitive Host adult forms sexual reproduction. Intermediate Host immature forms asexual reproduction
Toxoplasma gondii cosmopolitan distribution seropositive prevalence rates vary generally 20-75% generally causes very benign disease in immunocompetent adults tissue cyst forming coccidia predator-prey
More informationAlberta Health and Wellness Public Health Notifiable Disease Management Guidelines August 2011
August 2011 Amoebiasis Revision Dates Case Definition Reporting Requirements Remainder of the Guideline (i.e., Etiology to References sections inclusive) Case Definition August 2011 August 2011 October
More informationClinical Radiological Pathological Conference
Clinical Radiological Pathological Conference CASE 1: A 59-year-old female Housekeeper Live in Phuket, Thailand Progressive dyspnea for 1 year Present illness 1 year PTA : She developed dyspnea on exertion
More informationPARASITE MRS. OHOUD S.ALHUMAIDAN
PARASITE MRS. OHOUD S.ALHUMAIDAN OUTLINE Intruduction Important terms classification of hosts Mode of parasitic infections General Classification of parasites Specific Classification of parasites Protozoa
More informationSystemic lupus erythematosus (SLE): Pleuropulmonary Manifestations
08/30/10 09/26/10 Systemic lupus erythematosus (SLE): Pleuropulmonary Manifestations Camila Downey S. Universidad de Chile, School of Medicine, Year VII Harvard University, School of Medicine Sept 17,
More informationSushi Worms Diagnostic Challenges
Department Medicine Diagnostic Centre Swiss TPH Winter Symposium 2017 Helminth Infection from Transmission to Control Sushi Worms Diagnostic Challenges Beatrice Nickel Fish-borne helminth infections Consumption
More informationAmoebas are motile by means of pseudopodia cytoplasmic extensions which allow it to crawl across surfaces.
Chapter 23 Eukaryotic Parasites of Medical Importance: Protozoa and Helminths* *Lecture notes are to be used as a study guide only and do not represent the comprehensive information you will need to know
More informationAmoebiasis. (Amoebic dysentery)
Amoebiasis (Amoebic dysentery) Causative agent: Entamoeba histolytica Amoebiasis Harbouring of protozoa E. histolytica inside the body with or without disease only 10% of infected develop disease two types
More informationParasite Organism Chart Parasite Description Habitat/Sources of Isolation Blastocystis hominis
Blastocystis hominis B. hominis has recently been reclassified as a protozoan, of which there are thought to be four separate serologic groups. 1 This organism is transmitted via the fecal-oral route or
More informationGut parasites in general practice
Gut parasites in general practice A biased account Dr. Samson Wong Department of Microbiology The University of Hong Kong Classification of parasites Protozoa Helminths Arthropods Nematodes (roundworms)
More informationPurpose: To observe the different structures of a male and female Ascaris lumbricoides.
Biology 1 Name: Pre-lab Discussion: There are over 15,000 species in the Phylum Nematoda. They are round, unsegmented worms. Members of this phylum are free-living or parasitic. The parasitic species can
More informationTuberculosis Pathogenesis
Tuberculosis Pathogenesis Renuka Khurana, MD, MPH May 12, 2015 TB for Community Providers May 12, 2015 Phoenix, Arizona EXCELLENCE EXPERTISE INNOVATION Renuka Khurana, MD, MPH has the following disclosures
More informationTuberculosis Intensive
Tuberculosis Intensive San Antonio, Texas April 3 6, 2012 Tuberculosis Pathogenesis Lynn Horvath, MD April 3, 2012 Lynn Horvath, MD has the following disclosures to make: No conflict of interests No relevant
More informationRespiratory Diseases and Disorders
Chapter 9 Respiratory Diseases and Disorders Anatomy and Physiology Chest, lungs, and conducting airways Two parts: Upper respiratory system consists of nose, mouth, sinuses, pharynx, and larynx Lower
More informationCLINICAL FEATURES IN PULMONARY TUBERCULOSIS
CLINICAL FEATURES IN PULMONARY TUBERCULOSIS Dr. Amitesh Aggarwal Department of Medicine Tuberculosis Captain of all the Men of Death Great White Plague devastating effect on society 100 years ago one in
More informationImaging Spectrum of Allergic Lung Disease: Hypersensitivity Reactions on the Lung Parenchyma
Imaging Spectrum of Allergic Lung Disease: Hypersensitivity Reactions on the Lung Parenchyma Moon Sung Kim 1, Ki-Nam Lee 1, Won Jin Choi 1, Bo Ra Kim 1, Eun-Ju Kang 1 1 Department of Radiology, Dong-A
More informationDiagnosis and Medical Management of Latent TB Infection
Diagnosis and Medical Management of Latent TB Infection Marsha Majors, RN September 7, 2017 TB Contact Investigation 101 September 6 7, 2017 Little Rock, AR EXCELLENCE EXPERTISE INNOVATION Marsha Majors,
More informationIntroduction. Causes. Roundworms. Worms. Flatworms. How Flatworms are transmitted. Fast fact. Fast fact
Module 5 Worms MODULE 5 INTRODUCTION Introduction Worms Worms or helminths are parasites that live on or in human or animal hosts and draw nutrients from their host 1. Worms are multi-cellular, have complex
More informationRHODOCOCCUS EQUI. Post-mortem Environmental Persistence Specific Control Measures Release of Animals from Isolation
RHODOCOCCUS EQUI Definition Clinical Signs Transmission Diagnostic Sampling, Testing and Handling Post-mortem Environmental Persistence Specific Control Measures Release of Animals from Isolation Biosecurity
More informationChapter 16. Lung Abscess. Mosby items and derived items 2011, 2006 by Mosby, Inc., an affiliate of Elsevier Inc.
Chapter 16 Lung Abscess 1 EDA PM C AFC RB A B Figure 16-1. Lung abscess. A, Cross-sectional view of lung abscess. B, Consolidation and (C) excessive bronchial secretions are common secondary anatomic alterations
More informationTropical Parasitic Lung Diseases
Review Article Tropical Parasitic Lung Diseases V.K. Vijayan Vallabhbhai Patel Chest Institute, University of Delhi, Delhi, India ABSTRACT Though parasitic lung diseases are frequently seen in tropical
More informationReview Article Parasitic Pneumonia and Lung Involvement
BioMed Research International, Article ID 874021, 18 pages http://dx.doi.org/10.1155/2014/874021 Review Article Parasitic Pneumonia and Lung Involvement Attapon Cheepsattayakorn 1,2 and Ruangrong Cheepsattayakorn
More informationRadiological Aspects of Pulmonary Tuberculosis in Immunocompetent Hosts
Nov 2003 Radiological Aspects of Pulmonary Tuberculosis in Immunocompetent Hosts Josh Rempell, Harvard Medical School Year III Tuberculosis: the captain of all (wo)men of death Overall, one third of the
More informationParasitic infections of the lung: a guide for the respiratory physician
1 Department of Respiratory Medicine, Birmingham Heartlands Hospital, Birmingham, UK 2 Department of Clinical Parasitology, Hospital for Tropical Diseases, London, UK 3 Department of Respiratory Medicine,
More informationBrief Survey of Common Intestinal Parasites in the Tokyo Metropolitan Area. Tsukasa NOZAKI1), Kouichi NAGAKURA2)*, Hisae FUSEGAWA3)
Brief Survey of Common Intestinal Parasites in the Tokyo Metropolitan Area Tsukasa NOZAKI1), Kouichi NAGAKURA2)*, Hisae FUSEGAWA3) and Yasuhiko AND01),3) 1) Central Clinical Laboratoly, Tokai University
More informationTuberculosis. By: Shefaa Q aqa
Tuberculosis By: Shefaa Q aqa Tuberculosis is a communicable chronic granulomatous disease caused by Mycobacterium tuberculosis. It usually involves the lungs but may affect any organ or tissue in the
More informationStrongyloidiasis STATE-OF-THE-ART CLINICAL ARTICLE
949 STATE-OF-THE-ART CLINICAL ARTICLE Strongyloidiasis Adel A. F. Mahmoud Human infection with the intestinal nematode Strongyloides stercoralis is prevalent in tropical and subtropical regions of the
More informationAn Introduction to Radiology for TB Nurses
An Introduction to Radiology for TB Nurses Garold O. Minns, MD September 14, 2017 TB Nurse Case Management September 12 14, 2017 EXCELLENCE EXPERTISE INNOVATION Garold O. Minns, MD has the following disclosures
More informationParasitic Protozoa, Helminths, and Arthropod Vectors
PowerPoint Lecture Slides for MICROBIOLOGY ROBERT W. BAUMAN Chapter 23 Parasitic Protozoa, Helminths, and Arthropod Vectors Parasitic Diseases Protozoan and helminthic parasites are emerging as serious
More informationEnteric Parasites Overview ENTERIC PARASITES 101 GIARDIASIS. Description. Transmission
Enteric Parasites Overview ENTERIC PARASITES 101 Shira Shafir, PhD, MPH Assistant Professor Department of Center for Global and Immigrant Health UCLA School of Public Health 1 Types of Parasites: Protozoa:
More informationPARASITOLOGY CASE HISTORY #13 (BLOOD PARASITES) (Lynne S. Garcia)
PARASITOLOGY CASE HISTORY #13 (BLOOD PARASITES) (Lynne S. Garcia) An epidemiologic survey was undertaken in a small town in Myanmar (Burma) endemic for lymphatic filariasis. Blood specimens were collected
More informationDiseases: If you think about the spread of disease caused by parasites such as blindness, There are several infective causes of blindness :
Introduction : -The parasites are usually negligible and we don't take it seriously. - They cause diseases in the world. ( morbidity ) - Parasite means الطفيلي somebody who eats at someone else's table!!!!
More informationThe Nematodes (Round worms)
The Nematodes (Round worms) - Small, round, elongated, Non-segmented worms with body cavity. They have separate sexes, usually don t need an I.H and do not multiply in human host because eggs don t hatch
More informationAdvisory on Plague WHAT IS PLAGUE? 19 October 2017
19 October 2017 Advisory on Plague WHAT IS PLAGUE? Plague is an infectious disease caused by the zoonotic bacteria, Yersinia pestis. This bacteria often infects small rodents (like rats, mice, and squirrels)
More informationFungal Diseases of the Respiratory System
Fungal Diseases of the Respiratory System Histoplasmosis(cave disease) Dr. Hala Al Daghistani Histoplasmosis is a disease caused by the fungus Histoplasma capsulatum. Histoplasma capsulatum, is usually
More informationHepatitis E FAQs for Health Professionals
Hepatitis E FAQs for Health Professionals Index of Questions ± Overview and Statistics What is Hepatitis E? How common is Hepatitis E in the United States? Where is Hepatitis E most common? Are there different
More informationASTHMATIC PULMONARY EOSINOPHILIA
ASTHMATIC PULMONARY EOSINOPHILIA Pages with reference to book, From 300 To 302 Mohammad Zaman ( Department of Pulmonary Medicine, Pakistan Institute of Medical Sciences, Islamabad. ) Asthmatic pulmonary
More informationChapter 22. Pulmonary Infections
Chapter 22 Pulmonary Infections Objectives State the incidence of pneumonia in the United States and its economic impact. Discuss the current classification scheme for pneumonia and be able to define hospital-acquired
More informationIntroduction Parasitology. Parasitology Department Medical Faculty of Universitas Sumatera Utara
Introduction Parasitology Parasitology Department Medical Faculty of Universitas Sumatera Utara Parasite Definition: Dependence of one living organism on another 2 CLASSIFICATION (based on habitat) t)
More informationRe-Emerging Infectious of the CNS Danny A. Milner, Jr. MD
Re-Emerging Infectious of the CNS Danny A. Milner, Jr. MD This symposium has several main objectives: 1. Demonstrate the global burden of disease and the disproportionate amount of infectious diseases
More informationLearning Objectives. 3. Epidemiology distribution; endemic; 4. Basic Morphology 5. Name of diesease 6. Prevention and Control
Learning Objectives At the end of the class student will able to state 1. Life cycle Environment, Human, Animals 2. Name of parasite: (Genus), (Species) 3. Epidemiology distribution; endemic; 4. Basic
More informationTransient pulmonary infiltrations in cystic fibrosis due to allergic aspergillosis
Thorax (1965), 20, 385 Transient pulmonary infiltrations in cystic fibrosis due to allergic aspergillosis MARGARET MEARNS, WINIFRED YOUNG, AND JOHN BATTEN From the Queen Elizabeth Hospital, Hackney, and
More informationYersinia pestis. Yersinia and plague. Dr. Hala Al Daghistani
Yersinia pestis Dr. Hala Al Daghistani Yersinia species Short, pleomorphic gram-negative rods that can exhibit bipolar staining. Catalase positive, and microaerophilic or facultatively anaerobic. Animals
More informationTuberculosis - clinical forms. Dr. A.Torossian,, M.D., Ph. D. Department of Respiratory Diseases
Tuberculosis - clinical forms Dr. A.Torossian,, M.D., Ph. D. Department of Respiratory Diseases 1 TB DISEASE Primary Post-primary (Secondary) Common primary forms Primary complex Tuberculosis of the intrathoracic
More informationLiver Cancer (Hepatocellular Carcinoma or HCC) Overview
Liver Cancer (Hepatocellular Carcinoma or HCC) Overview Recent advances in liver cancer care seek to address the rising incidence of liver cancer, which has steadily increased over the past three decades.
More informationInterpretation of Chest Radiographs Paul Christensen, MD 10/21/09. Diagnostic Evaluation. Medical Evaluation & CXR Interpretation.
Diagnostic Evaluation Medical Evaluation & CXR Interpretation University of Michigan TB Consultant Washtenaw County Medical history Physical examination Testing for TB exposure (previously covered) Radiologic
More informationTuberculosis & Refugees in Philadelphia
Tuberculosis & Refugees in Philadelphia Philadelphia TB Control Program Daniel P. Dohony, MPH Philadelphia TB Control Program Health Information Portal Website: hip.phila.gov Contains Information On» Disease
More informationLEARNING OBJECTIVES Ø Describe the process or chain of infection. Ø Discuss the body s defenses for fighting infection and disease
Infectious Diseases LEARNING OBJECTIVES Ø Describe the process or chain of infection Ø Discuss the body s defenses for fighting infection and disease Ø Discuss the spread of infectious disease Ø Explain
More informationHelminths in the lungs
Parasite Immunology, 2014, 36, 463 474 DOI: 10.1111/pim.12102 Review Article Helminths in the lungs J. M. CRAIG & A. L. SCOTT Department of Molecular Microbiology and Immunology, Bloomberg School of Public
More informationParasitology. Helminthology (Helminths)
Parasitology Protozoology (Protozoa) Helminthology (Helminths) Entomology (Arthropodes) Platyhelminthes (flat worms) Nematheminthes (round worms) Trematodes Nematodes Cestodes Collection of the specimens
More informationDiagnosis of TB: Radiology David Finlay, MD
TB Intensive Tyler, Texas June 2-4, 2010 Diagnosis of TB: Radiology David Finlay, MD June 3, 2010 2stages stages- Tuberculosis 1. primary infection 2. reactivation, or post primary disease 2 1 Primary
More informationTrematodes General characteristics:-
Trematodes General characteristics:- 1- They are commonly referred to as flukes. 2- Life cycle have 3 morphologica form:- a- Egg b- Multiple larval stage c- Adult worm 3- The eggs, which are the primary
More informationThe Roundworms pg. 689
The Roundworms 27-2 pg. 689 What are the defining features of roundworms Advances over Platyhelminthes (the flatworms) Body plans and body systems 2 broad types and their example animals Parasitic worms:
More informationInfectious And Parasitic Diseases Of Captive Carnivores
Infectious And Parasitic Diseases Of Captive Carnivores 1 / 7 2 / 7 3 / 7 Infectious And Parasitic Diseases Of Journal Articles References and abstracts from MEDLINE/PubMed (National Library of Medicine)
More information