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Biomedical subjects

H C Seftel

Publications and source records attributed to H C Seftel.

At least 91 records · Page 5Linked to original sources
PubMed1981

The role of diet in the pathogenesis and control of hyperlipidemia after renal transplantation.

Twenty-one Caucasian renal transplant recipients with hyperlipidemia and normal renal function were assessed with regard to their diet. Their average daily intake of energy and cholesterol was lower and the ratio of polyunsaturated to saturated fat higher in their diet than in that of a comparable urban Caucasian South African population. Nevertheless modification of their diets in one year produced a significant lowering of their body weight and a statistically significant drop in the mean plasma cholesterol (9.2 +/- 0.5 mmoles/l to 7.6 +/- 0.5 mmoles/l, P less than 0.05). Although the fall in plasma triglyceride in the group as a whole was not statistically significant (3.8 +/- 0.6 mmoles/l to 3.2 +/- 0.5 mmoles/l) the level did decrease substantially in 13 of the 21 patients (4.2 +/- 0.9 mmoles/l to 2.5 +/- 0.5 mmoles/l, P less than 0.01). It is suggested that diet has a definite role in the control of post-transplant hyperlipidemia but should probably be introduced immediately after immunosuppression is started and be coupled with a suitable exercise program for optimal effect.

Adult↗
PubMed1980

The prevalence of ischaemic heart disease risk factors in middle-aged White miners.

The prevalence of ischaemic heart disease (IHD) risk factors was studied in a random sample of 3930 White miners, aged 45 - 62 years, of whom 202 had evidence of a definite or probable myocardial infarct (MI) on electrocardiographic and chest pain criteria. Ninety-two were classified as "suspect" MI cases and were excluded from the study. The prevalence of the major IHD risk factors (mildly elevated serum total cholesterol levels and blood pressure, and cigarette-smoking) in the 3636 White miners who had not had Mls did not differ from those in comparable populations in the UK, USA and Australia, nor did those of secondary IHD risk factors (elevated blood glucose and plasma uric acid levels and being overweight) differ in the various populations. There was, however, a relatively high percentage of middle-aged White miners with two (25.2%) and three (4.4%) simultaneous IHD risk factors. Such men have a much higher probability of an MI within 8 years than men with no IHD risk factors. This study indicates that 770 out of every 1000 middle-aged White miners would have one or more major IHD risk factors; of these, 252 would have two risk factors and 44 three risk factors. This finding points to the urgent need for an intervention programme for the early detection and prevention of IHD risk factors.

Blood Glucose↗
PubMed1980

A host of hypercholesterolaemic homozygotes in South Africa.

From 1972 to 1979 34 patients with homozygous familial hypercholesterolaemia were seen in one clinic in Johannesburg. All were Afrikaners and most lived in Transvaal Province. Their epidemiological, genetic, clinical, and biochemical characteristics were studied. The course of the disease varied considerably among the 34 patients, with no fewer than six surviving into their fourth or fifth decades. In some patients arterial atheroma was severe while cutaneotendinous xanthomas were slight and vice versa. Coronary heart disease was common but peripheral and cerebral arterial disease was rare. Another prominent finding was high concentrations of low-density lipoprotein cholesterol coupled with low high-density lipoprotein cholesterol values. The prevalences of homozygotes and heterozygotes with familial hypercholesterolaemia in Transvaal Afrikaners, calculated from this group of patients, were 1 in 30,000 and 1 in 100 respectively. These figures are the highest ever reported and may help to explain why South African whites have the highest death rate from coronary heart disease in the Western world.

Adolescent↗
PubMed1980

Familial hypercholesterolaemia--a common genetic disorder in the Afrikaans population.

Serum cholesterol levels have been studied in three groups of young White South Africans. The mean levels were highest among the Jewish (195,7 mg/dl or 5,10 mmol/l), lowest among the Afrikaans (174,9 mg/dl of 4,55 mmol/l), and intermediate in the English-speaking Gentile population (180,0 mg/dl or 4,67 mmol/l). Levels were significantly higher in females than in males in the Jewish and English-speaking Gentile populations, but not significantly higher in Afrikaans females compared with males. Studies carried out on the families of individuals found to have serum cholesterol levels above 300 mg/dl (7,8 mmol/l) emphasized that, in addition to the serum cholesterol studies, detailed family studies are essential if an accurate diagnosis of familial hypercholesterolaemia (FH) is to be made. From such studies in the Afrikaans population and also from the known number of homozygotes for FH in one area of South Africa, all of whom came from Afrikaans families, it has been estimated that the frequency of the FH gene is unusually high in this population. It is postulated that the latter finding could help to explain the high incidence of and mortality rate from ischaemic heart disease in young White South Africans.

Adolescent↗
PubMed1980

Distribution and biosocial correlations of blood pressure levels in Johannesburg blacks.

Blood pressures were measured in a sample of Johannesburg Blacks consisting of 5 018 men and 5 028 women attending the local Labour Bureau. Blood pressure levels correlated positively with age and body mass and were higher in males than females when weight was taken into account. Hypertension was common in both sexes and at most ages; in the 4th decade about one-third of men and women had phase 4 diastolic pressures greater than 90 mmHg. Correlations of blood pressure with a number of social variables were generally unimpressive. There was some evidence that blood pressure was inversely related to educational status and was higher in young adults who (a) lived apart from their families compared with those who lived in family units, and (b) grew up in a rural area and then migrated to Johannesburg compared with those who had lived in Johannesburg all their lives.

Adolescent↗
PubMed1980

Pituitary and thyroid function before and after portacaval anastomosis in patients with normal livers.

Basal plasma thyroid hormone, testosterone and cortisol levels, TSH and PRL responses to TRH, and LH and FSH responses to LRH were assessed in six young subjects with normal liver function and anatomy before and after portacaval anastomosis. All tests were normal and unchanged by the operations. It is concluded that in patients with normal liver function, portal systemic shunting does not produce alterations in the pituitary-gonadal and pituitary-thyroid axes. The abnormalities of these endocrine functions in patients with cirrhosis are probably related to the severity of hepatocellular dysfunction rather than to the effects of portal systemic shunting.

Adolescent↗
PubMed1979

The first published chemical analyses of smoke from South African cigarettes.

The smoke of 69 brands of cigarettes sold in South Africa in March 1978 was analysed for its content of tar, nicotine, carbon monoxide and carbon dioxide. The average yield of tar per cigarette varied between 30 and 38,5 mg in 27 brands and between 20 and 30 mg in all but one of the other 42 brands. The nicotine yields with one exception varied between 1,0 and 2,40 mg per cigarette and generally correlated well with those of tar (r = 0,75). The yields of carbon monoxide per cigarette generally ranged from about 14 to 32 mg, and those of carbon dioxide from about 50 to 85 mg. The results of this analysis, the first to be published with regard to South African cigarettes, are very disturbing. In particular, the tar yields are unacceptably high by international standards. They demand urgent action including (a) regular cigarette analyses by the Government, and publication of the results by the mass media, especially the SABC; (b) compulsory printing of the results of analyses on every cigarette pack and advertisement; (c) education of the public with regard to the meaning of the analyses; and (d) a programme designed to replace more dangerous cigarettes with less hazardous ones. Most important, all these measures must be implemented within the framework of a really meaningful, systematic, continuous and appropriate campaign aimed at combating the tobacco hazard at every level in all population groups.

Carbon Dioxide↗
PubMed1979

Haemostatic factors in Black and White diabetics.

Haemostatic factors in 33 Black and 32 White maturity-onset diabetics were analysed and compared with those in 19 normal Black and 19 White subjects. The Black-White diabetic group comparisons revealed depressed antithrombin (AT) III functional activity, a raised factor VII level and a raised factor V level in females in the White diabetic group. On comparing the White diabetics with their respective controls a rise in factor VIII and fibrinogen activity was demonstrated. These changes are suggestive of a hypercoagulable state in the White maturity-onset diabetic. In contrast, Black diabetics have higher functional AT III levels than their respective controls. This may indicate a protective reaction which would explain in part the reported lower incidence of occlusive vascular disease in this group. Platelet hyperactivity was not demonstrated in the majority of White and Black diabetics. Black diabetics and controls demonstrated higher factor VIII levels than the corresponding White groups, confirming previous observations of raised factor VIII levels among Blacks and suggesting that this feature is a racial characteristic.

Adult↗
PubMed1979

Treatment of familial hypercholesterolaemia by partial ileal bypass.

Ten patients with heterozygous familial hypercholesterolaemia (Fredrickson type II) were treated by the operation of partial ileal bypass. Postoperatively, serum cholesterol levels fell by an average of 34% (P less than 0.005), and the decrease was satisfactorily sustained over a period of 12-30 months. Angina and xanthomas also improved in some patients. Postoperatively all patients experienced considerable diarrhoea, which lessened with time. Other complications of surgery included abdominal distension and cramps, colonic dilatation, sepsis and intestinal obstruction. It is concluded that partial ileal bypass significantly lowers serum cholesterol levels, but that in view of the complications the operation should be offered only to carefully selected patients who are intolerant of or unresponsive to conservative measures.

Adult↗
PubMed1979

Adipose cell size in obese Africans: evidence against the existence of insulin resistance in some patients.

Aspects of adipose tissue cellularity were examined in 15 non-diabetic premenopausal African women with simple obesity living in Johannesburg. A smaller group of six non-obese Black women served as controls. Adipose tissue was obtained by biopsy from the deltoid, gluteal, and abdominal regions, and the mean fat cell size for each site was determined. Fasting plasma glucose, insulin, and lipid levels, and the glucose and insulin responses to a 100 g oral glucose load, in these subjects provided metabolic data for correlative analyses. As expected, the overall mean and regional adipocyte sizes were significantly larger in the overweight subjects. Significant regional variations in fat cell size were also seen, the gluteal region adipocytes being larger than those of other sites in both obese and non-obese women. A significant positive correlation was found between fat cell size and the percentage of ideal body weight. There was no significant relationship between adipocyte size, however, and any of the metabolic variables measured--notably basal or stimulated plasma insulin. Nearly half of the overweight women showed large adipocytes with normal plasma insulin concentrations. A proportion of African women with hypertrophic obesity do not appear to demonstrate any classical metabolic features of insulin resistance; this may be related partly to their high carbohydrate intake and unusual degree of physical activity. Our results do not, however, indicate that hyperinsulinaemia is completely absent in obese Black women.

Adipose Tissue↗
PubMed1979

Metabolic studies in acute asthma before and after treatment.

We studied the metabolism and hormone profile of 9 patients with moderately severe acute asthma before treatment, and again 10 min after intravenous aminophylline (250 mg) or the selective beta-adrenergic stimulant hexoprenaline (5 microgram) intravenously. Compared with basal values in normal subjects the untreated asthmatics had statistically significant raised mean plasma pancreatic glucagon, free fatty acid (FFA) and glucose levels in the plasma and a significantly depressed mean plasma potassium level. Insulin, growth hormone, cortisol, thyrotropin and ketone body levels were normal. The only significant changes after therapy were a further fall in plasma potassium in the hexoprenaline-treated patients and a rise in the mean lactate concentration of the group as a whole. The clinical implications of these findings are briefly considered.

Acute Disease↗
PubMed1978

The rarity of coronary heart disease in South African blacks.

Coronary heart disease (CHD) remains an uncommon disorder in the South African Black population. It has been suggested that herein lies an enigma, since it is believed that these people are considerably exposed to the conventional risk factors for CHD. To test this belief I have assessed the exposure of Black people, in time and degree, to the following CHD risk factors: affluence, age, hypertension, hyperlipidaemia, dietary excess, smoking, physical inactivity, diabetes, obesity, hyperuricaemia and hyperinsulinism. Among males only hypertension, and among females only hypertension and obesity, emerged as prominent factors. However, neither of these is significantly atherogenic in the social, nutritional and metabolic milieu in which Blacks generally live, and obesity is a doubtful atherogenic factor, even in westernized populations. It is therefore concluded that the rarity of CHD in Blacks is not enigmatic, but is appropriate to their environmental circumstances.

Adolescent↗
PubMed1978

Hormonal and metabolic responses to an oral glucose load in obese Black diabetics.

Plasma insulin responses to a 4-hour glucose tolerance (100 g) were studied in urbanized Black people. Persons of normal weight without diabetes (12) and obese persons without diabetes (18) were compared with obese diabetics (19). Fasting serum ketone levels were measured, and the plasma potassium, triglyceride and growth hormone responses during the glucose tolerance test were determined. Obese subjects without diabetes had a twofold greater total plasma insulin response (area under curve) than their counterparts of normal weight, but there was a progressive fall in total plasma insulin response from subjects with mild diabetes (with fasting normoglycaemia) to those with severe diabetes (with fasting hyperglycaemia). The early plasma insulin responses of the group with mild diabetes were significantly impaired, and the peak response was only reached at 120 minutes. The subjects with severe diabetes had a flat insulin response curve. Fasting serum ketone levels were highest in the group with severe diabetes. The growth hormone responses were similar in all the groups. Plasma potassium and tryglyceride levels fell less during the glucose tolerance test in the group with severe diabetes than in the other three groups. These data indicate that insulin secretion is reduced in obese Blacks with chemical evidence of diabetes and this reduction becomes severe in the symptomatic diabetic.

Adult↗