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Biomedical subjects

J D Kark

Publications and source records attributed to J D Kark.

At least 109 records · Page 6Linked to original sources
PubMed1982

A serological survey of Rift Valley fever antibodies in the northern Sinai.

In the aftermath of an extensive Egyptian Rift Valley fever (RVF) epidemic during 1977-78, RVF activity in the adjacent Sinai peninsula has been inferred from the presence of haemagglutination-inhibition (HI) antibodies in sera from indigenous humans and rodents. We attempted to confirm these findings by HI testing of sera from Israeli soldiers serving in the region of the El Arish Wadi system in the Sinai, and from indigenous rodents. Six of 199 human sera (3.0%) and two of 88 rodent sera (2.3%) were positive, but none reacted in the more specific plaque-reduction neutralization test. We conclude that there is no definitive serological evidence for RVF activity in the Sinai and that sera reacting in the HI test must be confirmed by a more specific serological procedure.

Animals↗
PubMed1982

A rift Valley fever vaccine trial. I. Side effects and serologic response over a six-month follow-up.

A formalin-inactivated Rift Valley fever vaccine, originally produced in primary monkey kidney cells, has been used to protect laboratory workers. A trial of a modified vaccine, newly formulated in well-characterized diploid fetal rhesus lung cells, was conducted with 114 men aged 19--24 years. Of the 107 subjects who received up to three injections of 0.1 to 1 ml vaccine (an additional seven received a placebo) one had a local hypersensitivity-type reaction and another a generalized urticarial syndrome. Both cases had a prior history of hypersensitivity states. No pyrogenicity was detected and only insignificant systemic reactions were recorded. Mild and transient local reactions ranged from 5% at the lowest dose level to 43% at the highest. Serologic response, as assessed by plaque reduction neutralizing antibody titers, was dose dependent. Within a single vaccine lot tested at multiple dose levels, peak (day 42) geometric mean titers ranged from 48 (at 0.1 ml x 3) to 436 (at 1.0 ml x 3). Reciprocal titers of greater than or equal to 40 are considered to be protective. Comparison of three lots at the 0.5 ml level indicated between lot variability, though this was not statistically significant. A sharp decline in antibody titers was observed in all vaccination groups by day 84; six months after vaccination apparently protective antibody titers were present only in groups that received 1 ml x 3 and 0.5 ml x 3 of the most antigenic lot of vaccine. These results suggest that 1) the vaccine is generally nonreactogenic, but individuals with a prior history of hypersensitivity states should be observed for allergic side effects; 2) existing vaccine supplies cannot be extended by using lower dose levels without a lower and less sustained serologic response; 3) a booster dose is necessary six months or more following the primary series; 4) although the current TSI-GSD-200 vaccine is immunogenic, a more potent vaccine is needed.

Adult↗
PubMed1982

Pre-exposure prophylaxis with immune serum globulin for prevention of viral hepatitis in army recruits.

A controlled trial with pre-exposure immune serum globulin was undertaken in Israel Defence Forces (IDF) recruits, an indigenous population living in a hyperendemic area for hepatitis A. The objective was to examine whether the prevailing IDF policy of postexposure administration of immune serum globulin prophylaxis should be modified to further reduce the incidence of infectious hepatitis in the IDF. Altogether 23 447 recruits were systematically allocated on their first day of service into an intervention group and a control group. Over the 18-month follow-up period 18 cases of non-B viral hepatitis were identified among the 10 943 vaccinees and 41 among the 12 504 non-immunised group. Protection over six months was about 85%, and over the entire 18 months 50%. Protection was evident until about 40 weeks' follow-up and may have persisted for longer. Rates in the non-immunised were lower than expected, alluding to the possibility of herd immunity. IDF immunisation policy was successfully altered after this trial.

Adolescent↗
PubMed1982

Seasonal changes in plasma lipid and lipoprotein levels in Jerusalem.

Seasonal variations were observed for fasting total plasma cholesterol, high-density lipoprotein-cholesterol (HDL-C), estimated low-density lipoprotein-cholesterol (LDL-C), and the ratio of HDL-C to total cholesterol (TC), measured in 5,244 middle-aged men and women in Jerusalem. HDL-C was highest in winter and lowest in summer, and triglycerides showed a mirror image of this pattern. TC and LDL-C followed a more complex wave form, levels of these being high in the winter, decreasing to a trough in the summer and increasing rapidly to a peak in the autumn. The ratio of HDL-C to TC was lowest in early autumn and highest in winter and early spring. There were two- to fivefold changes in the prevalence of hypercholesterolemia, hypertriglyceridemia and high LDL-C according to the season of examination. These findings imply that clinicians should take season into account when diagnosing hyperlipidemia and when evaluating apparent success or failure in its treatment. Studies of lipid distributions and of interventions aimed at lipid modification need to consider the potentially confounding effects of season.

Cholesterol↗
PubMed1982

Reported physical activity and blood lipids in Jerusalem adults.

The association of physical activity and fasting plasma lipids and lipoproteins was studied in an adult Jerusalem population consisting of 1,095 men and 614 women. Participants were questioned about habitual physical activity, and the relationship of their reported levels of activity of fasting lipid and lipoprotein values was examined. After adjustment was made for age, ethnic origin, body mass, season, cigarette smoking and alcohol consumption, the following associations were found: 1) an inverse association of reported physical activity with triglyceride, total cholesterol and very low-density lipoprotein-cholesterol (not significant), and 2) a significant positive association between reported activity and high-density lipoprotein-cholesterol in men. These findings generally confirm results found in other Western populations. Too few women reported moderate or strenuous physical activity to permit an examination of lipid associations in women.

Adult↗
PubMed1982

Nutrient intake in Jerusalem--effects of origin, social class and education.

The independent association of ethnic group, social class and education with nutrient intake was studied in a sample of 1,294 adults in the Jerusalem Lipid Research Clinic (LRC) population. By univariate analysis, intake of fat and saturated fatty acids (SFA) was higher (P less than or equal to 0.05) in males and females of the upper social classes (classified by the occupation of the head of the family) than in the lower classes, while the opposite trend was found for the consumption of carbohydrates and starch. In men, an association between social class and the intakes of protein and other carbohydrates (i.e., other than sucrose and starch) and the ratio of polyunsaturated fatty acids (PFA) to SFA (P:S ratio) was also found. In both sexes, the mean intakes of SFA and other carbohydrates were higher and that of starch lower in subjects with a higher level of education (P less than or equal to 0.05). Education was also associated with the consumption of protein and fat in males and with that of carbohydrates and sucrose in females. Country of origin was related (P less than or equal to 0.05) to the intake of fat, SFA and other carbohydrates in both sexes, to that of protein and cholesterol in males and to that of carbohydrates, sucrose and starch in females. The P:S ratio of the diet of male subjects was also associated with origin. Using various models of analysis of variance, it was shown that origin was associated with nutrient intake (P less than or equal to 0.10), independent of the effect of social class and education for protein, fat, SFA, cholesterol, sucrose and other carbohydrates in males, and for fat, SFA, PFA and other carbohydrates in females. The P:S ratio of the male diet was also associated with origin. The level of education was independently related (P less than or equal to 0.10) to the intake of fat, SFA, starch and other carbohydrates in males and to that of sucrose in females, while social class was associated independently with carbohydrate consumption in males only. After prior adjustment for origin, education had a stronger residual effect than did social class in males, while in females the associations of social class and education with nutrient intake were almost identical.

Adolescent↗
PubMed1982

Cigarette smoking, blood pressure and pulse rate in the Jerusalem Lipid Research Clinic Prevalence Study.

The relationship between cigarette smoking and blood pressure (BP) and pulse rate (PR) was studied in a sample of 1,242 Jerusalem youngsters and 1,703 adults. Confounding effects of age, body mass, ethnic origin and season were controlled in the analysis. Both mean systolic (SBP) and diastolic blood pressure (DBP) were lower in smokers than in nonsmokers, with greater differences in both generations in females (women 4.5 mm Hg, P = 0.004 and girls 3.9 mm Hg, P less than 0.001 for SBP; women 2.3 mm Hg, P = 0.024 and girls 2.6 mm Hg, P = 0.002 for DBP) than among the males (men 1.5 mm Hg, P = 0.15 and boys 2.0 mm Hg, P = 0.022 for SBP; men 1.3 mm Hg, P = 0.05 and boys 1.8 mm Hg, P = 0.01 for DBP). The relative odds of being in the upper age, ethnic and body mass index-adjusted quintiles of SBP for nonsmokers were 1.3, 1.9, 2.1, and 3.5 for men, boys, women, and girls, respectively. For DBP they were 1.3, 1.7, 1.1, and 2.1, respectively. No significant trends for BP varying with number of cigarettes smoked were noted in either adults or youngsters. Only adult male smokers had slightly higher PRs. The relatively small differences in BP may be of pharmacologic or psychobehavioral interest, but do not counter the well-described deleterious effects of cigarette smoking.

Adolescent↗
PubMed1982

Correlates of biochemical variables in the Jerusalem Lipid Research Clinic population.

The associations of sex, age and ethnic origin with hematocrit and biochemical variables were studied in the Visit 2 population of the Jerusalem Lipid Research Clinic--1,709 adults and 1,248 17-yr-olds. Differences in globulin, alkaline phosphatase, creatinine and uric acid levels were statistically significant by ethnic origin in both youngsters and adults. Differences by sex and age in many of the variables studied suggested hormonal effects that were more pronounced before the age of menopause. The data presented, relating to a multiethnic free-living population, may provide a useful reference for physicians in this region for distributions of these variables in the population.

Adolescent↗
PubMed1982

Cigarette smoking and its relation to anthropometric characteristics and biochemical variables in Jerusalem 17-year-olds and adults.

The relationship of weight, height, Quetelet index, hematocrit and blood levels of thyroxine, globulin, bilirubin, creatinine, aspartate aminotransferase, uric acid, alkaline phosphatase and glucose to smoking was studied in a Jerusalem population sample of youngsters aged 17 yr and their parents. Among youngsters, male smokers had a higher body mass index than did male nonsmokers. In adults, both men and women smokers were slightly leaner than ex-smokers and, in women, smokers were clearly leaner than those who had never smoked. Generally, the associations of smoking with the biochemical variables were weaker in youngsters than in adults. In men, lower mean levels of creatinine, bilirubin, aspartate aminotransferase and uric acid were observed among smokers. Hematocrit levels were somewhat higher in both young and adult smokers of both sexes, being more so in adults. Smokers showed consistently lower globulin levels than did nonsmokers. Plasma glucose levels were somewhat lower in youngsters of both sexes who smoked. Serum thyroxine levels were slightly increased in female smokers, suggesting a hormonal effect of smoking. These findings are discussed in light of the published literature.

Adolescent↗
PubMed1982

Calculation of LDL-cholesterol from total cholesterol, triglyceride and HDL-cholesterol: a comparison of methods in the Jerusalem Lipid Research Clinic Prevalence Study.

Methods for estimating the cholesterol content of the plasma very low-density lipoprotein (VLDL-C) and low-density lipoprotein (LDL-C) fractions were examined in an ethnically diverse population sample from the Jerusalem Lipid Research Clinic Prevalence Study. None of these methods required the use of preparative ultracentrifuge. The often-used method for estimating VLDL-C by multiplying the triglyceride (TG) value by 0.20 was compared with two other models in which linear regression functions were computed for VLDL-C (determined by ultracentrifugation) as the dependent variable and TG as the independent variable. Subsequently, the intercept and the slope coefficients were used for estimation of VLDL-C and LDL-C. In the first regression model, overall age and sex regression coefficients were applied, whereas in the second regression model, the coefficients were calculated within different TG ranges. All three models were similar in their predictive accuracy when applied to the total population sample. However, in subjects with high TG levels, the second regression model was preferable.

Adolescent↗
PubMed1981

Hepatitis A antibody in Israel Defence Forces recruits.

Sera drawn from a sample of 1,147 military inductees, representative of the conscript population entering service in the Israel Defence Forces (IDF), in 1977, were examined by radioimmunoassay for hepatitis A virus (HAV) antibody. The prevalence of HAV antibody is considerably higher in males of Eastern origin (84.4%) than of Western origins (39.7%) and in females of Eastern origin (79.9%) as compared with those of Western origin (30.3%). The difference between males and females is not statistically significant when level of education is controlled. An inverse association between years of schooling and HAV antibodies is evident both for males and females, but is stronger in Westerners than Easterners. These findings have implications for HAV prevention in the IDF.

Adolescent↗
PubMed1981

The antigenicity of whole virus versus subunit trivalent influenza vaccines -- a field trial in the Israel Defence Forces, 1978.

A single dose of a commercial trivalent influenza subunit vaccine (SV) and two whole virus vaccines (WVV) were compared in a randomized, placebo-controlled field trial of subjects under 23 years of age in the Israel Defence Forces. Sixty percent of SV recipients and 29% and 37% of WVV recipients showed no measurable response to the H1N1 subtype (A/USSR). When the prevaccination titer to H1N1 was less than 10, SV did not differ significantly from the placebo, and when greater than or equal to 10, the SV was poorer than the WVV. Response to the H3N2 (A/Texas) component was excellent, but when the prevaccination titer was less than 10, SV appeared less immunogenic than WVV. All three vaccines performed equally against the B/Hong Kong strain.

Adolescent↗
PubMed1981

The relationship between epidemic influenza (A(H1N1) and ABO blood group.

An outbreak of influenza caused by the A(H1N1) subtype in military recruits in February 1978 afforded an opportunity to study the association of ABO blood groups with influenza morbidity and serological response. Fifty-eight per cent of 336 recruits became clinically ill. There was no differential distribution of clinical influenza by blood group. However, seroconversion to a titre of greater than or equal to 20 was significantly and appreciably higher in groups A and B than O and AB. Also, among those with serologically confirmed clinical influenza, the occurrence was significantly higher in groups A and B than groups O and AB.

ABO Blood-Group System↗
PubMed1981

Smoking and epidemic influenza-like illness in female military recruits: a brief survey.

An outbreak of influenza-like disease caused illness among 48 per cent of 173 female military recruits, 35 per cent of whom smoked cigarettes. The risk of influenza-like illness was greater in smokers (60.0 per cent) than in nonsmokers (41.6 per cent), with a risk ratio of 1.44 (95 per cent CL 1.03-2.01). Among those ill, a significantly greater proportion of smokers visited the clinic than nonsmokers. This could have been due to more severe illness among smokers, or to a greater tendency to visit the physician. The proportion of influenza-like disease attributable to smoking in this population was 13 per cent.

Female↗