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Biomedical subjects

J Simons

Publications and source records attributed to J Simons.

At least 55 records · Page 3Linked to original sources
PubMed1987

Chylomicrons and chylomicron remnants in coronary artery disease: a case-control study.

Epidemiologic studies of coronary artery disease have largely overlooked the role of triglyceride-rich lipoproteins circulating in the post-prandial state. We have conducted a case-control study in males which examined fasting plasma lipoproteins and lipoproteins circulating 4 h after ingestion of a test meal containing fat and cholesterol. The cases were 82 subjects with coronary artery disease confirmed by angiography, while there were two control groups: one group of 38 'hospital controls' free of significant coronary disease by angiography, and a second group of 61 'workforce controls' free of coronary disease on historical grounds. Mean plasma and LDL cholesterol levels were significantly higher and HDL cholesterol levels were significantly lower in cases than in controls. The apo-B48/apo-B100 ratio in lipoproteins Sf greater than 60 obtained 4 h post-prandially, a relative measure of chylomicron and remnant presence, was significantly higher in cases than in controls. After pooling of all data, the prevalence of coronary artery disease was found to increase progressively with the concentration of plasma cholesterol and triglycerides, total cholesterol/HDL cholesterol ratio and the apo-B48/apo-B100 ratio in Sf greater than 60, the relative risk being highest for total cholesterol/HDL cholesterol ratio. After controlling for the confounding effects of age and other lipid factors via multiple logistic regression, apo-B48/apo-B100 ratio was still a significant predictor of coronary artery disease presence (z = 1.97, P less than 0.05) in a 'dose-response' fashion. The risk of coronary artery disease in the top quartile of apo-B48/apo-B100 distribution was 2.2-fold greater than that for the bottom quartile, after adjustment for the effects of other risk factors.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1986

Non-Purkinje cell GABAergic innervation of the deep cerebellar nuclei: a quantitative immunocytochemical study in C57BL and in Purkinje cell degeneration mutant mice.

Purkinje cell degeneration (pcd) mutant mice, 3-4 months old, were used to identify and quantify the non-Purkinje cell GABAergic innervation of deep cerebellar nuclei. Glutamic acid decarboxylase (GAD) immunoreactive structures appeared as dark dots throughout the 4 nuclei. Ultrastructural examination confirmed that each dot corresponded to an axon terminal. GAD-labeled boutons were large, contained tightly packed flattened vesicles and established Gray type II synapses with all nuclear neuronal populations. Thus, cytological criteria did not distinguish between Purkinje cell and non-Purkinje cell GAD-positive nerve terminals, since they shared many common features. The number of GAD-immunoreactive axon terminals in the deep nuclei of pcd cerebella was compared to that of normal C57BL mice. Despite an almost complete disappearance of Purkinje cells in the pcd mouse (less than 0.05% of these neurons remained in the mutants), the surface density of GAD-positive nerve terminals in the deep nuclear region was 37% of control value. Taking into account a volumetric decrease of 58% for the deep nuclei of the mutant cerebellum, we estimated the percentage of GAD-positive boutons innervating these nuclei to be 15% of normal values. This important residual innervation of the deep nuclei might arise from local GABAergic neurons, which were identified in the normal and mutant cerebella by immunostaining with an anti-GABA antibody.

Animals↗
PubMed1986

Education level and coronary risk factors in Australians.

There is an inverse association between social class ranking and mortality from coronary heart disease in Australia and in some other countries. To explain whether this association is related to differences in risk factors, the relationship between coronary risk factors and the highest level of education completed was explored for a reasonably representative cross-section of the adult Australian population. After adjustment for the effects of age, relative weight and alcohol intake, blood pressure was found to vary inversely with education level in both sexes. In men only plasma cholesterol, triglycerides and high density lipoprotein cholesterol levels showed no significant variation with education level. In women, plasma triglycerides and high density lipoprotein cholesterol levels varied inversely with education level after adjustment. There was less cigarette smoking among more highly educated men but no clear smoking trends among women. The findings broadly confirm the results of similar analyses which used occupation as the measure of social class and have implications for future community education programmes in that present strategies may be inappropriate for less highly-educated members of society.

Alcohol Drinking↗
PubMed1986

Antihypertensive and biochemical dose-response study of tripamide.

Tripamide is an experimental sulfonamide-derived diuretic antihypertensive agent. Twenty-four hospitalized patients with essential hypertension received placebo followed by 10, 25, 50, or 100 mg of tripamide daily in a randomized, double-blind design. All doses of tripamide significantly lowered standing arterial pressure. Changes in blood pressure, heart rate, and weight were not dose related, but the decrease in mean arterial pressure was significantly related to both age (P less than 0.02) and pretreatment blood pressure (P less than 0.05). Serum potassium levels were lowered significantly by the 25 and 100 mg daily doses of tripamide, whereas all doses of tripamide significantly reduced serum chloride levels and produced an increase in serum uric acid levels. Disparate time courses of antihypertensive and diuretic effects and the lack of a relationship between the increase in urine volume and the change in blood pressure suggest an additional antihypertensive action of tripamide or a delayed physiologic adaptation to volume depletion. Equal antihypertensive effects over the range of 10 to 100 mg/day, but greater hypokalemia at higher doses, suggest that future studies should employ the lower doses of tripamide.

Adult↗
PubMed1986

A multimodal system for reconstruction and quantification of neurologic structures.

The utility of computers and computer graphics as aids in the study of nervous system architecture is growing. However, modern histologic, immunocytologic and biochemical methods for revealing the underlying microarchitecture and macroarchitecture of the nervous system yield data formats requiring disparate computer acquisition, analysis and display approaches, capable of spanning many orders of magnitude of scale. This paper describes the Image Graphics Laboratory data acquisition, processing and display system, whose various components and programs may be used singly or in concert to enable definition of various tissue properties at different levels of resolution and integration. Examples are given of the system's use in light microscopic two-dimensional and three-dimensional reconstructions, autoradiographic reconstructions, reconstructions from projected images, reconstructions of impregnated cells (e.g., whole neurons) and peripheral nerve image analysis.

Animals↗
PubMed1985

Simple fluorimetric screening for carazolol in swine kidneys by means of Sep-Pak cartridges.

A simple method to determine the beta-blocker carazolol in swine kidneys is presented. Spiked samples, homogenised under alkaline conditions, were heated. Passage of the ether extracts through C18 and silica Sep-Pak cartridges yielded a fraction containing the carazolol in 88% recovery. In this fraction carazolol was determined by fluorescence spectrophotometry. By this method a level of 1 microgram/kg in spiked samples can be detected. Injection of 10 micrograms/kg body weight, 105 minutes before slaughter, resulted in carazolol contents in kidneys ranging from 11 to 25 micrograms/kg (n = 8).

Adrenergic beta-Antagonists↗
PubMed1984

Health lifestyle education in high schools. A three-year follow-up study.

An experimental "healthy lifestyle programme" was initiated in Year 7 (first year of high school) in selected high schools in 1980 and was conducted over a three-year period. The programme had two main objectives: to influence attitudes and increase knowledge about health matters, in order to improve lifestyle; and to strengthen the general case for the more organized instruction of schoolchildren in this field. As part of the programme, children were given lessons on nutrition, physical activity and fitness, and on alcohol, tobacco and drugs. The programme was reasonably implemented in three of the four schools which took part in the experiment. Significant improvements, over three years, in attitudes and knowledge about health and nutrition and a reduction in cigarette smoking, were noted among children in schools where the programme had been implemented reasonably. The reasons for the partial success of the programme are discussed.

Attitude to Health↗
PubMed1984

How "representative" are subjects attending a coronary risk factor screening programme?

Coronary risk factors were compared in two groups of subjects aged 25-64 years. One group voluntarily, and at no cost, attended a risk factor screening clinic (n = 3844), while the second group represented a population sample drawn from the metropolitan Sydney electoral roll (n = 1394). Older subjects were over-represented in the screening clinic compared with the electoral roll sample. Hypercholesterolemia was more prevalent in the screening clinic in older females, while hypertension and current cigarette smoking were less prevalent in the screening clinic in older subjects of both sexes. Obesity was less prevalent in the screening clinic in older males. A voluntary screening programme may generate a unique and possibly unreproducible population sample.

Adult↗
PubMed1984

The interactions of body weight, age, cigarette smoking and hormone usage with blood pressure and plasma lipids in an Australian community.

The predicted variation of blood pressure and plasma lipid levels, based on association with body weight, age, cigarette smoking and oral contraceptive usage, was examined in 47 000 self-referred subjects who attended a community programme for coronary risk factor screening. In both sexes, blood pressure and plasma lipid (cholesterol and triglyceride) levels were positively correlated with age and body mass index (BMI, kg/m2). Plasma triglyceride concentrations were positively correlated with cigarette smoking. Partial correlation analysis showed age and BMI to be independently correlated with blood pressure and plasma lipids. Plasma cholesterol and triglyceride levels were correlated with each other independently of the effects of age and BMI. Multiple regression analysis showed age to be a more powerful predictor of blood pressure and plasma lipid levels in females than in males, while BMI was a more powerful predictor of blood pressure and plasma lipid levels in males than in females. Current cigarette smoking did not contribute to the prediction of blood pressure or plasma cholesterol level in either sex, but did predict a 10% higher plasma triglyceride level in both sexes. Oral contraceptive usage did not contribute to the prediction of plasma cholesterol level in multiple regression analysis, but did predict higher plasma triglyceride and blood pressure levels. In view of the high prevalence of overweight people in the Australian community, weight reduction would probably be associated with a significant fall in the risk of coronary heart disease, particularly in males.

Adolescent↗
PubMed1982

Health attitudes and knowledge, and coronary risk factors in high-school children, Sydney and Inverell.

Attitudes to, and knowledge of, health and nutrition, together with presence of major coronary risk factors, were assessed in New south Wales high-school students at the start of an experimental healthy lifestyle programme. Data were obtained for 2596 children (mean age, 12.5 to 15.5 years), of whom 1971 lived in Sydney and 625 in rural Inverell. Girls had higher scores than boys on questions related to nutrition and fitness attitudes. Girls' scores on questions related to health attitudes and knowledge and nutrition attitudes and knowledge increased with age. The earliest precursors of coronary heart disease and chronic lung diseases were present in this group of children, of whom 20% to 30% were smoking cigarettes, 30% were overweight or obese, 8% to 15% of boys and 2% to 7% of girls had high blood pressure, and 9% had hypercholesterolaemia.

Adolescent↗
PubMed1982

Preliminary results of Rorschach protocols of pre and post operative transsexuals.

Presented are initial descriptive results of two administrations of the Rorschach over a 5-year period to a group of 20 transsexuals. Of the 20, 10 were female to male and 10 were male to female. Five of the female to male transsexuals had during the 5-year period gone on for surgery, as had 5 of the female to males. Discussion focuses on the differences and similarities between pre- and post-operative groups as well as contrasting both groups with norms of the general population. Results suggest that there are no obvious differences between the transsexual group and norms for the general population.

Adult↗
PubMed1982

Fatness and skeletal maturity of Belgian boys 12 through 17 years of age.

Relationships between fatness and skeletal maturity are considered in a nationwide sample of 14,259 Belgian boys 12 through 17 years of age (The Leuven Growth Study of Belgian Boys). Absolute fatness was estimated from four skinfolds using the Drinkwater and Ross technique and from the sum of four skinfolds, and was related to skeletal maturity assessed by the Tanner-Whitehouse method (I and II). In addition, comparisons were made between the fattest 5% and leanest 5% of the boys at each age level. Correlations between the indices of fatness and skeletal age and relative skeletal age (the difference between skeletal and chronological ages) are positive and generally low, ranging from 0.12 to 0.39. They tend to decrease with age from 12 to 17 years. Comparisons between the extreme groups indicate that the leanest boys are more delayed in skeletal maturity, by about 0.8 years, than the fattest boys are advanced, by about 0.5 years. Stature data for the same boys are consistent with the skeletal maturity data and thus suggest that the size differences between the extreme groups are due in part to maturity differences. Over the age span 12 through 20 years, the leanest boys are reduced in stature by about -1.2 standard deviations, while the fattest boys are larger in stature by about +0.6 standard deviation units. The size differences, however, persist after skeletal maturity is attained so that there may be a specific role for fatness in influencing statural growth.

Adipose Tissue↗
PubMed1981

Coronary risk factors in a rural community which includes aborigines: Inverell Heart Disease Prevention Programme.

A coronary risk factor screening and referral service was established in Inverell, New South Wales, in July 1978. In non-Aboriginal subjects, there was an increasing prevalence of coronary risk factors with age (hyperlipidaemia, hypertension and obesity), except for cigarette smoking which showed a reverse trend. Allowing for minor differences in sampling, the average level of plasma cholesterol, blood pressure and cigarette smoking in rural inverell closely resembled that in Sydney. However, Inverell subjects of both sexes were consistently more overweight at all ages. Aboriginal subjects of both sexes showed an increased prevalence of hypertriglyceridaemia and cigarette smoking compared with non-Aboriginal subjects, whilst hypertension and obesity were also more prevalent in the Aboriginal females. High Coronary risk Inverell subjects sustained significant improvements in serum cholesterol, cigarette smoking and body weight levels over one year of follow-up. Community-wide control of hypertension was initially unsatisfactory and this remained so.

Adult↗