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Biomedical subjects

L Epstein

Publications and source records attributed to L Epstein.

At least 109 records · Page 6Linked to original sources

Enhancement of cysteamine cytotoxicity by hyperthermia and its modification by catalase and superoxide dismutase in Chinese hamster ovary cells.

Chinese hamster ovary cells were exposed to the sulfhydryl compound cysteamine at concentrations ranging from 0 to 8 mM for 120 min. No toxicity was found in cells maintained at 5 degrees during treatment; however, at 37 degrees and 44 degrees a paradoxical toxicity was observed, i.e., substantial toxicity was observed at cysteamine concentrations of 0.2 to 1 mM but decreased at higher drug concentrations. When drug-treated cells were exposed to a 30-min 44 degrees -heat treatment (surviving fraction, 0.15 in the absence of drug) toxicity was markedly enhanced. At 0.4 mM cysteamine, the surviving fraction was approximately 0.6 at 5 degrees, 0.01 at 37 degrees, and 0.00008 when the 44 degrees -heat treatment was also used. Cysteamine toxicity was not modified by the addition of superoxide dismutase (10 micrograms/ml) but was completely blocked by the addition of catalase (50 micrograms/ml) over the drug concentration range of 0.2 to 2.0 mM. Cysteamine autoxidation as measured by O2 uptake at 0.4 mM proceeds through hydrogen peroxide (H2O2) production as evidenced by the regeneration of O2 upon the addition of catalase. In contrast, at 4.0 mM cysteamine, O2 regeneration was not pronounced. The data suggest that the production of H2O2 is the first reaction step in the mechanism of cysteamine toxicity. The subsequent production of highly reactive oxygen species like hydroxyl radicals (.OH) from H2O2 in the presence of reduced metal (Fenton chemistry) probably leads to the observed cellular toxicity.

Animals↗

The meaning of patient satisfaction with prepaid primary health care in Israel.

This paper reports the development of a self-administered Hebrew-language questionnaire for assessing patient satisfaction with primary care in Israel. Four scale measures of patient satisfaction were empirically constructed. These scales pertained to doctor conduct, doctor-patient communication, teamwork, and ease of access. In addition, a single direct question was used to measure overall satisfaction with the care. Ratings of all aspects of care were negatively skewed, with doctor-conduct and doctor-patient communication usually being the most satisfactory aspects and access the least satisfactory. It was shown that different practices, or the same practice at different points in time, can easily and meaningfully be compared, using mean satisfaction scores, measures of standard deviation, or percentages in each practice with ratings above (or below) the overall mean of all practices. The use of specific measures of patient satisfaction for comparison and intervention is discussed.

Analysis of Variance↗

Family and community medicine: complementary components of primary health care.

An integrated practice of family and community medicine can address the problems of primary health care better than can either of these alone. This comprehensive practice will provide a family-oriented service based on epidemiologically defined needs and thus can perform ongoing evaluation of its programs. To become a reality, this requires changes in priorities and budget allocation in the health services as a whole, improvements in manpower training, and the provision of adequate tools for data collection and for epidemiological analysis.

Chronic Disease↗

Health-related behavior in Israel adolescents.

Eight hundred and four high school students were interviewed about selected health-related behaviors in an effort to determine the interrelationships of these characteristics. We found the age of onset and present use of cigarettes by the adolescents to be positively correlated to their use of hashish and having sexual intercourse. The use of hashish and having sexual intercourse were also positively related with each other and the use of hashish to drinking alcohol.

Adolescent↗

Cancer incidence in kibbutzim in Israel.

The incidence of cancer among the Jewish members of 43 collective settlements (kibbutzim) in the Beisan and Jezreel Valleys is reviewed. These settlements, apart from their geographical distribution, may be taken as a representative sample of the kibbutzim throughout Israel. This review covers the period 1960-72, during which 415 malignant tumors were diagnosed in a population experiencing 253,232 person-years of risk. The incidence was compared with that of the Jewish population in Israel as a whole, and the result was used as an approximation of the country's urban/kibbutz ratio. Cancers of the lip, malignant melanomas and cancer of the female breast were more common in the kibbutz population. Malignancies of the respiratory tract were less common among males living on kibbutzim than in the total Jewish male population of Israel. These differences are probably related to social and environmental factors.

Adolescent↗

Ischemic heart disease in Israel: changes over 30 years.

As in most of the industralized nations of the world, ischemic heart disease is the major cause of death in the adult population of Israel. The first two and a half decades since the founding of the State in 1948 were typified by a constant rise in morbidity and mortality from this disease in all ethnic groups in this heterogeneous population. Major changes in health-related behavior in the immigrant groups resulted in a rise in the disease rates that ranked this country among those with the highest incidence rates in the world. Since 1972-74 there is evidence of a fall in mortality in all ethnic groups. There is less conclusive evidence of a possible fall in morbidity as reflected by hospital admissions. These reductions are too recent for their full significance and the possible factors involved to be clear.

Adult↗

Multilocular cysts of kidney: a diagnostic dilemma.

Multilocular cyst of the kidney is a rare pathologic entity occurring in both children and adults. Although diagnosis cannot be firmly established preoperatively, the use of intravenous pyelography, angiography, ultrasonography, and delta scan may aid in its diagnosis. Because of the difficulty in accurate diagnosis and the documented association with renal neoplasia, we recommend exploration and possible nephrectomy as the treatments of choice.

Diagnosis, Differential↗

[Degradation by phytohemagglutinin of the antiviral state induced by interferon].

Phytohaemagglutinin (PHA M and P forms), when added to L 929 cells previously treated by murine interferon, degrades the antiviral state and restores virus sensitivity in the cells. This degradation depends on the amount of the lectin, the contact period with the cell and the presence of PHA membrane receptors. The importance of membrane configuration not only in the induction but also in the maintenance of the antiviral state is discussed.

Cell Membrane↗

Vigorous exercise in leisure time, coronary risk-factors, and resting electrocardiogram in middle-aged male civil servants.

During 1968 to 1970, approximately 17 000 middle-aged male executive grade civil service officers, all of them engaged in sedentary or very light work, recorded on a Monday morning their leisure time activities over the previous Friday and Saturday. In 1971 a sample of 509 of these men completed further questionnaires for medical, social, and smoking history; these men had a resting electrocardiogram, and height, weight, skinfold thickness, blood pressure, and plasma total cholesterol were measured. Vigorous exercise in leisure time had previously been reported by 125 (25%) of the men, and these as a group had significantly fewer electrocardiographic abnormalities (changes compatible with myocardial ischaemia, ectopic beats, and sinus tachycardia) than the men not reporting vigorous exercise (P less than 0-02). This difference remained when all men with any history suggestive of cardiovascular disease were excluded from the analysis. Blood pressure, plasma total cholesterol, and smoking habits were examined with respect both to vigorous exercise and to the electrocardiogram, but the only relation found was that electrocardiographic abnormality increased with increasing blood pressure. Even among men with higher pressures, however, those reporting vigorous exercise had fewer electrographic abnormalities than the others. The results provide further support for the association of habitual physical activity with coronary health.

Adult↗