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Biomedical subjects

J G Kral

Publications and source records attributed to J G Kral.

At least 109 records · Page 6Linked to original sources

Effects of castration and testosterone substitution on body composition and muscle metabolism in rats.

Male weanling Wistar rats were castrated or sham-operated and followed for 12 weeks without substitution or with large (2 mg . 14 days-1) or small (0.2 mg . 14 days-1) intramuscular dose of testosterone enantate. Castration without substitution was associated with lower body weight and smaller fat cell sizes in different adipose tissue depots. The epididymal and caudal subcutaneous depots were the most sensitive to castration. The percentage of fast-twitch high-oxidative (type II A) muscle fibers decreased in the non-substituted castrated animals. There was a decrease in phosphorylase and lactate dehydrogenase activities in the white portion of the gastrocnemius muscle of the castrates. These changes were reversed by the large dose of testosterone. Removal of testosterone by castration thus seems to "feminize" male rats with respect to body composition and muscle metabolism.

Adipose Tissue↗

Possible systemic metabolic effects of regional adiposity in a patient with Werner's syndrome.

A patient with Werner's syndrome, partial lipoatrophy and diabetes mellitus presented several of the metabolic alterations found in obesity and maturity-onset diabetes, in spite of a total body-fat mass which was markedly reduced when compared to randomly-selected women. The data show elevated blood sugar and free fatty acids, hyperinsulinemia, elevated glucaon and suppressed growth-hormone levels. Metabolic studies with isolated adipocytes show evidence of increased lipolytic response to catecholamines, diminished binding of insulin and decreased antilipolytic effect of this hormone. A striking feature of this patient's adipose tissue was the contrast between lipoatrophy in the subcutaneous tissue of the extremities and augmented abdominatl subcutaneous adipose tissue. The adipocyte size in this region was very large (1.6 micrograms lipid/cell) and among the largest ever recorded in this laboratory. It is proposed that a 'regional adiposity', particularly in the abdominal area, with enhanced adipocyte size and adipocyte metabolic contributions, may promote the metabolic events and alterations that are more typically observed in the generalized form of obesity.

Adipose Tissue↗

Inhibition of prostaglandin synthesis as a treatment for biliary pain.

Twenty patients with confirmed gallbladder disease were treated with intravenous indomethacin during 24 separate attacks of biliary pain. In all cases the pain was promptly relieved and there were no important side-effects. Indomethacin, and inhibitor of prostaglandin synthesis, may reduce intraluminal pressure in the gallbladder, and relieve pain.

Cholelithiasis↗

Vagotomy as a treatment for morbid obesity.

Based on animal experiments, on the original clinical observations of Dragstedt, and on similarities with appetitive behavior after jejunoileostomy, truncal vagotomy has been attempted as a treatment for morbid obesity in 13 patients with a mean weight of 123 kg. Weight decreases of 20 to 30 kg (range, 2 to 64 kg) have been observed so far. Impaired gastric emptying alone does not seem to account for the decreases. Possibly, improved glucose tolerance with reduction of hyperinsulinemia and other hormonal and/or neural effects are responsible for weight loss and lack of "hunger." The period of observation is short, yet 2 of the 13 patients seem to be failures, of whom one had gastric hyposecretion before operation. It is too early to consider the procedure for general clinical use, which must await further research efforts.

Adult↗

Histamine metabolism in severe obesity before and after jejuno-ileostomy.

Histamine metabolism was studied in three patients during histamine-reduced diet before and at intervals after jejuno-ileostomy by analyses of the urinary excretion of non-labelled and 14C-labelled histamine and its metabolites. Labelled histamine was administered intravenously and orally. The preoperative excretion of free histamine and its endogenously formed metabolites was essentially the same as in controls. After intestinal bypass the inactivation of [14C]histamine by both routes of administration was not impaired. Pronounced increases in the excretion of non-labelled conjugated histamine (acetylhistamine) and methylimidazoleacetic acid were found at different intervals postoperatively. This was probably due to histamine synthesis by intestinal bacteria since the diet only contained minute quantities of histamine. It is concluded that the increased urinary excretion of conjugated histamine after intestinal bypass indicated an abnormal bacterial activity in the intestine.

Adult↗

Increased arterial-tissue cholesterol after intestinal bypass in severe obesity.

Cholesterol content was measured in biopsy specimens of mesenteric artery taken at the time of jejuno-ileal bypass from 4 very obese patients aged 19, 22, 27, and 42. When their body-weight had become stable (mean 22 months) after operation, biopsy specimens of the temporal artery were obtained from 3 patients and of a mesenteric artery from 1. Cholesterol content had increased significantly. The increase in arterial-tissue cholesterol was concomitant with decreases in serum high-density (H.D.L.) and low-density (L.D.L.) lipoprotien cholesterol.

Adult↗

Vagotomy for treatment of severe obesity.

Three women weighing 137, 133, and 135 kg underwent truncal vagotomy; after 16, 20, and 24 weeks they had lost 10, 17, and 19 kg respectively without serious side-effects. No dietary restrictions have been imposed, but they are eating less than they were preoperatively and report a total lack of hunger. Truncal vagotomy may be a useful treatment for severe obesity.

Adult↗

Body composition and adipose tissue cellularity before and after jejuno-ileostomy in severely obese subjects.

In severe obesity with adipose tissue hyperplasia it is difficult to achieve and sustain weight decrease by conventional therapy. Fifteen severely obese patients (mean body weight 135 kg) with hyperplastic obesity had a jejuno-ileostomy according to Payne to induce weight reduction by controlled malabsorption. Body composition, adipose tissue cellularity, and glucose tolerance were studied before and after the operation when the patients had reached a new stable weight (WS) a mean 21 months after surgery. Preoperative fat cell number was unchanged at follow-up in contrast to all other variables of body composition. Reductions in fat cell size were evenly distributed in different major subcutaneous regions. Body potassium was determined immediately after operation and at 6 months intervals until WS. The postoperative decrease stopped at 6 months, thus differing from the decrease in body weight. Significant positive correlations between the postoperative decrease in body weight or body fat, and preoperative body weight, body fat and body cell mass were analysed by multiple stepwise regression. Preoperative body weight and body fat were shown to predict postoperative weight loss at a leve of P less than 0.005. A positive correlation between body fat decrease and fat cell number could be explained hypothetically by an increased caloric demand in hyperplastic obesity.

Adipose Tissue↗

Cholesterol and DNA content in arterial tissue in severe obesity: their relation to some risk factors for ischaemic heart disease.

Arterial tissue was obtained from twelve severely obese patients during jejuno-ileal by-pass surgery. The arterial DNA content was inversely correlated with the sum of venous glucose values during an oral glucose tolerance test (rs = -0.72). This observation may have implications on the known relationship between decreased glucose tolerance and early manifestations of atherosclerosis.

Adult↗

Surgical reduction of adipose tissue in the male Sprague-Dawley rat.

The lipostatic theory of regulation of adipose tissue mass was tested by a method for surgical reduction (adipectomy) of 24% of the total body fat of nonobese adult Sprague-Dawley rats, as judged from carcass analyses. The reduction persisted during an observation period of 12 wk without any evidence of altered food intake, weight gain, or compensatory hypertrophy or hyperplasia of adipose tissue compared with sham-operated controls. No changes were found in serum free fatty acids, glycerol, triglycerides, cholesterol, or insulin between adipectomized and control animals, implying an intact quantitative function of the remaining adipose tissue. It is concluded that the size of the adipocytes rather than the number is important for a presumed lipostatic regulation of adipose tissue mass in the adult male Sprague-Dawley rat.

Adipose Tissue↗

The effects of castration on body composition, adipose tissue cellularity and lipid and carbohydrate metabolism in adult male rats.

Gonadal hormones affect body composition, food intake, weight gain and serum lipids in numerous species including man. In this study, mature male Sprague-Dawley rats were castrated or sham-operated at 16 weeks of age. During the 6-week observation period with weekly records of food intake and weight gain, these parameters were significantly lower in the castrated group. The decrease in food intake in this group could not account for the difference in body weight between the groups, indicating a lower feed utilisation in the castrates. At sacrifice accessory reproductive organs, the levator ani muscle, thymus and adrenals were dissected for determination of organ weight and histology, revealing significant reductions in the accessory reproductive organs and levator ani of the castrates. The thymus was significantly heavier in the castrated animals. No differences were found in the adrenals. Two of the sham-operated animals had signs of accidental functional castration. The proportion of body cell mass and total lipid of the carcass was the same in both groups. Significant reductions in adipocyte weights were found in the epididymal depots of the castrated rats. Blood samples taken at sacrifice in pentobarbital anaesthesia were analysed for glucose, insulin, triglycerides, cholesterol, FFA, glycerol and protein. Statistically significant reductions in triglycerides and protein were recorded in the castrated animals without any significant changes in the other parameters studied. The results are discussed with reference to the age of castration and the importance of the reduced food intake in castrated animals.

Adipose Tissue↗

Surgical reduction of adipose tissue hypercellularity in man.

Surgical removal of adipose tissue is a widely practised form of plastic surgery most often aimed at correcting cosmetic defects after extreme weight reduction such as a pendulous abdomen. However, it has not been proposed as a cure for obesity. Evidence for an interaction between the adipose tissue mass and regulation of food intake and energy balance might suggest that a reduction of body fat could favorably influence obesity. This study presents body composition data on five patients with a mean body weight of 136 kg with hyperplastic obesity who after a mean weight reduction of 46 kg by conventional therapy were subjected to extensive plastic surgery aimed at removing supernumerary fat cells. Analysis of adipose tissue cellularity revealed that 12-18% of the total number of fat cells were removed by combinations of abdominoplasty and lumbar and femoral adipectomy. There were no indications that this reduction of adipose tissue mass could prevent the recurrence of obesity in these patients, though there was no evidence for regeneration of adipose tissue in situ.

Adipose Tissue↗