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J S Keystone

Publications and source records attributed to J S Keystone.

At least 55 records · Page 3Linked to original sources
PubMed1992

Skin problems in returning travelers.

A new skin lesion in a returning traveler often poses a difficult diagnostic problem for the clinician whose knowledge of geographic medicine is limited. To reach a diagnosis the physician has to consider the location and style of travel, exposure to pathogens, length of stay, epidemiology, incubation period, and clinical presentation of dermatologic diseases in the countries visited. As with any dermatologic problem, the appearance of the presenting lesion should help to establish the differential diagnosis. This article is a guide to the diagnosis and investigation of skin lesions in returning travelers; it is not intended as a comprehensive review of tropical dermatology.

Diagnosis, Differential↗
PubMed1992

Circumsporozoite genotyping of global isolates of Plasmodium vivax from dried blood specimens.

The prevalence and global distribution of two circumsporozoite (CS) genotypes of Plasmodium vivax (VK210 and VK247) were determined by genetic analysis of isolates from 234 malaria-infected patients. Whole blood specimens were collected on filter paper from patients infected with malaria in Thailand, Mexico, Papua New Guinea, Peru, Afghanistan (Pakistan), India, and western Africa and from 50 asymptomatic smear-negative controls. Following extraction of DNA from the filter paper samples, the CS gene was amplified by the polymerase chain reaction and genotyped by using oligoprobes specific for the VK210 and VK247 repeat epitopes. The sensitivity of genotyping from a single blood dot was 95.2%. The VK247 CS genotype was identified in the blood of patients from all seven study areas and was the predominant form present in samples from Thailand (83%) and Papua New Guinea (90%). In contrast, VK247 DNA was present in only 9% of isolates from Mexico. Individuals infected with both genotypes simultaneously were identified in all study areas except Mexico and were particularly common in Thailand (58%) and Papua New Guinea (60%). These findings indicate that the VK247 genotype of P. vivax is widely distributed but that its prevalence varies geographically. In addition, we conclude that use of samples of whole blood on filter paper is a practical and sensitive method for determining the genotypes of large numbers of malaria isolates collected in field settings.

Amino Acid Sequence↗
PubMed1992

Prevention of traveler's diarrhea.

Preventing traveler's diarrhea is usually a matter of common sense, good luck, and the host's ability to defend against enteric pathogens, particularly enterotoxigenic Escherichia coli. Untreated tap water, ice cubes, unpasteurized milk products, salads, food from street vendors, and dining in unhygienic-appearing restaurants should be avoided. Well-cooked food that is served hot and carbonated, commercially bottled beverages are usually safe. Food and water precautions, however, are no guarantee of success in preventing traveler's diarrhea. Bismuth subsalicylate used prophylactically is somewhat inconvenient and is only moderately effective. Although antibiotic prophylaxis is very effective for traveler's diarrhea, particularly the quinolones, it should be reserved for high-risk travelers.

Anti-Bacterial Agents↗
PubMed1991

Cutaneous eruptions in Indian tick typhus.

Although frequently unrecognized, rickettsial infections may be an important cause for fever and exanthem in persons presenting to physicians in South India. Most often these patients are referred to dermatology departments with a diagnosis of "drug eruption." In the current study the authors analyzed 12 cases of rickettsial fever that were seen in the dermatology department of St. John's Medical College Hospital, Bangalore, between 1985 and 1989. The distinctive cutaneous eruption was found to be an important clue to an early clinical diagnosis. Specific serodiagnosis enabled us to confirm that Indian tick typhus, a member of the spotted fever group, was the most frequent cause for rickettsial fever presenting at our hospital.

Adolescent↗
PubMed1991

Transmission of health information on leprosy from children to their families: another approach to health education.

A controlled study was carried out in the North Arcot District of Tamil Nadu, South India to determine whether health information given to schoolchildren would influence the knowledge and attitudes of their families concerning leprosy. A total of 41 children and almost all of their household members participated in the study. The study, conducted by questionnaire, involved a pre-test of knowledge and attitude about leprosy of seventh standard students and their families. After one group of children received health education about leprosy and the other received information about tuberculosis, an identical post-test questionnaire was administered to all participants. Although significant improvement in knowledge about leprosy was detected in the leprosy educated group of children compared with controls, no transmission of information on leprosy was detected in the family members of either group. The attitudes of the children who had been educated about leprosy may have been adversely affected by the health education session. The reasons for our failure to detect significant transfer of information about leprosy in this setting are discussed, as well as the need for additional research in this area.

Adolescent↗
PubMed1990

Treatment of malaria--1990.

Malaria has become an increasingly common health problem in the 1970s and 1980s, both in areas where infection is endemic and in travellers returning to non-endemic areas. The severity of infection varies widely, depending on the plasmodial species involved, and there is an extensive chemotherapeutic armamentarium currently available to combat malarial infection. Drug chemistry, pharmacokinetics, mechanism of drug action and resistance, and toxicities are outlined for the cinchona alkaloids (quinine and quinidine), chloroquine, amodiaquine, pyrimethamine, the sulphonamides, pyrimethamine/sulfadoxine, mefloquine, pyrimethamine/sulfadoxine/mefloquine, the sesquiterpene lactones, primaquine, and other drugs. A knowledge of the distribution of drug resistance is vital for the provision of effective antimalarial therapy, and current information in this area is outlined. Chloroquine remains the mainstay of treatment for the erythrocytic stages of Plasmodium vivax, P. ovale, P. malariae, and chloroquine-sensitive P. falciparum malaria. The dormant hepatic stages of P. vivax and P. ovale also require further treatment with primaquine. Quinine, alone or in combination with other drugs, is the primary agent used to treat chloroquine-resistant falciparum malaria. Falciparum infection can rapidly become fatal, therefore its complications of multiple organ failure, heavy parasitaemias, cerebral malaria, and hypoglycaemia must be recognised and managed promptly. Because these protozoal parasitic infections are now encountered throughout the world and can become life-threatening, a wide variety of practitioners must become more familiar with their correct treatment.

Animals↗
PubMed1990

Prevention of malaria.

With the increased spread of chloroquine-resistant Plasmodium falciparum malaria and mounting evidence of lack of efficacy and toxicity of alternative drugs, it has become extremely difficult to propose simple, widely applicable and uniformly acceptable recommendations for malaria chemoprophylaxis. With regard to specific drugs, it is clear that because of its toxicity amodiaquine should no longer be used for chemoprophylaxis, and that pyrimethamine/sulfadoxine should, for the most part, be used only as a presumptive therapy. The pyrimethamine/dapsone combination is promising, but data on its efficacy are limited. Although proguanil (chloroguanide) is recommended by several sources because of its safety, disturbing reports of chemoprophylaxis failure in Africa and a well-documented lack of efficacy in South East Asia would suggest that its usefulness may be limited. However, a recent study has documented the efficacy of a proguanil-sulphonamide combination in Thailand, an area of high grade chloroquine resistance. Although long term studies of drug safety are not yet available, doxycycline and mefloquine appear to be the drugs of choice in areas where P. falciparum shows multidrug resistance. Regardless of the drug regimen recommended for chemoprophylaxis, travellers must be informed that no present-day antimalarial agent guarantees protection against malaria.

Animals↗
PubMed1990

Rewarding medical teaching excellence in a major Canadian teaching hospital.

A major Canadian teaching hospital has developed a program to recognize and reward excellence in medical education. The program includes a system to collect and evaluate feedback from trainees and administrators--with an annual celebration event where awards are presented. Three categories of hospital-wide awards are presented: educational administration, program development, and extraordinary contribution. There are departmental awards for best undergraduate and postgraduate physicians, allied health professional, and house staff/fellow. This program functioned well to evaluate teachers across departments and for all levels of trainees in the hospital and will expand to become part of the ongoing evaluation of teachers in the institution.

Awards and Prizes↗
PubMed1990

Effect of malaria chemoprophylaxis on the development of antibodies to Plasmodium falciparum in expatriates living in west Africa.

We studied the relationship between exposure to malaria, the use of long-term chemoprophylaxis with chloroquine, and the prevalence of sporozoite antibodies in 446 expatriates who had lived in 7 West African countries for 6 months-41 years. Filter paper blood samples from 12% of the subjects had antibodies to the repeat region of the Plasmodium falciparum circumsporozoite protein, with a positive correlation between enzyme-linked immunosorbent assay (ELISA) absorbance and years of exposure (r = 0.32, P = less than 0.01). Development of sporozoite antibodies did not correlate with reported use of chloroquine. Ten samples from expatriates with the highest ELISA titers and 10 samples from West African nationals, which were matched for ELISA titer and duration of exposure, were characterized more fully. All 20 samples reacted strongly with sporozoites by immunofluorescence. The 10 samples from nationals reacted strongly with liver-stage antigens by immunofluorescence and with blood-stage antigens by immunofluorescence and immunoblotting. In contrast, the 10 samples from expatriates were negative or only weakly positive in the liver- and blood-stage assays. These results imply that sporozoite antibodies are generally not cross-reactive with blood-stage antigens, and suggest that protective immunity to malaria does not develop during long-term malaria chemoprophylaxis against the erythrocytic stage.

Adolescent↗
PubMed1988

Recurrent hydatid disease during pregnancy.

A Syrian woman with pulmonary and hepatic Echinococcus granulosus had symptoms of hydatid disease during each of three consecutive pregnancies. We postulate that the decrease in cellular immunity that accompanies pregnancy might allow for increased parasite growth. Obstetricians should be aware of the potential during pregnancy for rapid progression and complications of hydatid disease.

Abortion, Spontaneous↗
PubMed1987

The electrophoretic isoenzyme patterns of strains of Entamoeba histolytica isolated in two major cities in Canada.

The isoenzyme patterns of 92 isolates of Entamoeba histolytica from British Columbia and 28 from Ontario were determined. Seropositivity for E. histolytica was assessed by indirect hemagglutination and enzyme-linked immunosorbent assay in the one center and by ELISA and amebic gel diffusion in the other. In both British Columbia and Ontario nonpathogenic zymodemes I and III were most common. A newly described isoenzyme pattern was identified in Ontario. Only 9 of 120 zymodeme patterns identified were found to be pathogenic strains of E. histolytica. Pathogenic isolates were strongly correlated with clinical symptoms and seropositivity.

Animals↗