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Biomedical subjects

J G Kral

Publications and source records attributed to J G Kral.

At least 91 records · Page 5Linked to original sources
PubMed1985

Morbid obesity and related health risks.

Persons 45.4 kg (100 lb) or more above desirable weight have exponential increases in mortality and serious morbidity compared with normal persons. The presence of a complication or an independent coronary risk factor along with obesity increases the mortality further. Among the "threshold conditions" that appear at a critical level of body weight (60% or more above desirable weight), the most important are sudden unexplained death, ventilatory disorders, circulatory congestion, and functional limitations in activities of daily living. Recent epidemiologic data on extreme obesity and data on cardiac dysfunction show impaired quality of life in young, morbidly obese patients. Because of the malignant nature of morbid obesity and the inability to achieve and maintain sufficient weight reduction by non-surgical means, surgery is justified in this population.

Activities of Daily Living↗
PubMed1984

Effects of castration on adipose tissue growth and regrowth in the male rat.

Adipose tissue has been found to regrow in the male rat following surgical removal (lipectomy) of inguinal subcutaneous depots, but the degree of regrowth has varied widely across experiments. It is possible that at least part of the disparity of previous findings occurred because of differences among the experiments in the testicular integrity of experimental animals. To address this possibility, the present study examined effects of castration on adipose tissue regrowth in rats treated either as weanlings or as young adults. Male Sprague-Dawley rats, at either 4 or 15 weeks of age, were subjected to one of four surgical procedures: bilateral lipectomy of the inguinal subcutaneous depots; castration; lipectomy and weight gain, but castrated rats achieved a higher ratio of adipose weight to body weight than noncastrated rats. In rats lipectomized but not castrated at 15 weeks of age, partial regeneration and a small increase in growth of noninguinal subcutaneous adipose tissue combined to produce substantial restoration of adipose mass. The same surgery in 4-week-old rats did not result in significant restoration because growth of noninguinal subcutaneous adipose tissue was reduced. In rats that were both castrated and lipectomized, regrowth of adipose tissue was substantial regardless of age at time of surgery. Thus, castration is seen to impede body weight gain while sparing ordinary growth of adipose tissue and facilitating regrowth of adipose tissue following lipectomy. Since adipose tissue regrowth varied with age only in noncastrated rats, it appears to be facilitated as well by testicular maturation.

Adipose Tissue↗
PubMed1984

Modification of weight gain by an alpha-glucosidase inhibitor during refeeding in rats.

In rats, the period of refeeding after a fast is associated with accelerated weight gain without a concomitant increase in food intake. In this study the alpha-glucosidase inhibitor, acarbose, was used to delay carbohydrate absorption in normal adult rats, and the effects on body weight, food intake, and intestinal enzyme activities were determined. Refeeding with acarbose in the food (500 mg/kg) reduced the rate of weight gain compared to refeeding without acarbose but did not change food intake. Acarbose also lowered midjejunal mass and blunted the refeeding-induced rise in certain brush border disaccharidase and intracellular glycolytic enzymes. However, acarbose refed rats still had accelerated weight gain compared to nonfasted rats, implying that the refeeding response was not totally abolished. These studies suggest that inhibition of carbohydrate absorption during refeeding might have a role in the maintenance of diet-induced weight loss.

Acarbose↗
PubMed1984

Accumulation of IgG and complement factor C3 in human arterial endothelium and atherosclerotic lesions.

Endothelial injury is associated with an intracellular accumulation of IgG. Fluorescent antibodies were used to detect IgG and complement factor C3 in biopsies of human arteries. Both proteins were found in endothelial cells with signs of injury, in normal and atherosclerotic arteries. Rhodamine-conjugated anti-IgG and FITC-conjugated anti-C3 were used to count the number of IgG- and C3-containing endothelial cells in non-atherosclerotic cystic arteries. IgG was found in 26% of the cells, with C3 in 38% of the IgG-containing cells. Both IgG and C3 were also observed in the subendothelial intima of cystic arteries and in atherosclerotic lesions of iliac and femoral arteries. The accumulation of IgG and C3 in injured endothelium and in atherosclerotic lesions could be of importance for complement-mediated tissue destruction and for the attraction and activation of white blood cells.

Adult↗
PubMed1983

Behavioral effects of vagotomy in humans.

Animal experiments and clinical observations have demonstrated significant effects of vagotomy on body weight. Weight loss or inability to regain are partly due to impaired motility and secretomotor activity of the vagus nerve causing disturbances in digestion which, however, are not sufficient to explain most of the weight deficit after vagotomy in animals or morbidly obese patients. The body weight deficit is also due to reduced caloric intake with changes in the quantity and quality of food and liquid intake, the latter accounting for more than one-third of the total reduction in caloric intake. Obese patients have consistent decreases in hunger ratings after vagotomy and also reveal changed hedonic ratings and estimations of taste intensity. Validation of vagotomy studies requires tests of vagal integrity to confirm the completeness of the surgery and rule out regeneration of nerve tissue or recruitment of function. Tests of completeness of vagotomy are difficult to perform and evaluate in morbidly obese patients due to insulin resistance. The finding of an inadequate gastric acid response to insulin hypoglycemia implies a defect hypothalamic response to hypoglycemic stress in these patients. A new postoperative test of completeness of vagotomy based on disrupted drinking after intravenous hypertonic saline challenge is introduced as an attractive alternative to the potentially hazardous insulin test.

Behavior↗
PubMed1983

Acute radiorenography during attacks of renal colic.

Acute radiorenography was compared to emergency excretory urography to evaluate its diagnostic accuracy in 22 patients with clinical signs of renal colic, including erythrocytes in the urinalysis. All 16 patients with delayed excretion and/or dilated renal pelves on excretory urography had delayed excretion of radioactivity on renography. Furthermore, 6 patients with reduced renal function judged by renography had marked or slight delay in excretion on excretory urography. Small stones not causing stasis were found on excretory urography in 2 patients with normal renograms. It is concluded that acute radiorenography is simple, rapid and safe, and identifies accurately patients with abnormal renal function during attacks of colic, with less risks than excretory urography of causing renal damage or aggravating the pain of renal colic.

Adult↗
PubMed1982

Arterial cholesterol and DNA contents in relation to serum lipids and apolipoproteins. Studies on cystic artery biopsies.

Though various relationships between serum lipoprotein levels and risk for atherosclerotic disease have been shown there are only a few studies on the relationships between serum lipoprotein levels and the lipid contents of the arterial wall. This study presents cholesterol and DNA contents of arterial tissue from biopsies of the cystic artery in 23 patients with uncomplicated cholecystolithiasis. Serum levels of cholesterol, triglycerides, alphalipoprotein cholesterol, apoA-I, A-II and B were determined, and the relationships between artery and serum variables were calculated. There was a positive correlation between serum apoB and the arterial cholesterol, normalized to the DNA contents (r = 0.43, P less than 0.05). There was a tendency towards an inverse correlation between the alpha-lipoprotein cholesterol levels and the arterial cholesterol (r = 0.39, P less than 0.10). There were no significant correlations between serum apoA-I or A-II and the arterial cholesterol contents. These data indicate that deposition of cholesterol in the arterial wall is related to the serum level of apoB, with higher levels of arterial cholesterol at higher serum levels of apoB. Earlier observations of an inverse correlation between alphalipoprotein cholesterol and arterial cholesterol could, however, not be conclusively confirmed.U

Adult↗
PubMed1982

Refeeding after fasting in the rat: energy substrate fluxes and replenishment of energy stores.

Rats were fasted and refed and concentrations of plasma glucose, glycerol, triglyceride, insulin, and glucagon as well as glucose kinetics after injection of labeled glucose and glycerol were determined. In addition, concentrations and synthesis in vivo (from tritiated water) and in vitro of glycogen, triglycerides, and protein were followed in liver, muscle, and adipose tissues. The refeeding state after fasting was characterized by a decrease in glucose and triglyceride concentrations in plasma. Glucose turnover rate was increased. Protein losses were repleted, first in the liver then in muscle tissue. Synthesis of glycogen and lipid increased above control in liver and adipose tissue. These results are compatible with an increased outflux during refeeding of different energy substrates from plasma into the depleted protein and energy stores to an extent causing lower concentration of these substrates. Such phenomena might be of importance for energy intake regulation during the phase.

Adipose Tissue↗
PubMed1982

Refeeding after a fast in rats: effects on small intestinal enzymes.

The effect of resuming food intake after a period of starvation (refeeding) on the specific activities of selected rat intestinal enzymes was determined. The rate of weight gain was higher in refed animals than in control animals, without a difference in food intake. Fasting caused intestinal atrophy which reversed rapidly on refeeding. Fasting decreased the specific activities of sucrase, maltase, and galactokinase, but did not affect the specific activities of hexokinase, pyruvate kinase, or crypt thymidine kinase. Sucrase, maltase, hexokinase, pyruvate kinase, and thymidine kinase specific activities all rose above control values during refeeding. The overshoot in intestinal enzyme specific activities may help promote the rapid weight gain observed in refed rats and is an integral part of the total adaptation to fasting and refeeding.

Animals↗
PubMed1981

Vagal mechanisms in appetite regulation.

Though the importance of the vagal nerve for appetitive behavior has been known for a decade, with extensive studies of vagal physiology being performed since the end of the last century, it has not been until recently that major progress has been made in elucidating some of the vagal mechanisms involved in food intake. This short review summarizes methods for studying vagal function, vagal transmission and physiological vagal effects important for appetite regulation normally and in relation to hypothalamic function. Particular emphasis is placed on effects of vagotomy on body weight.

Appetite Regulation↗
PubMed1981

Truncal vagotomy in morbid obesity.

Vagotomy has been shown to reduce body weight in several species of experimental animals. Due to the relative safety and simplicity of the procedure and the long-clinical evaluation of vagotomy in ulcer disease, truncal vagotomy without drainage has been performed in a series of 21 morbidly obese patients. The mean maximum body weight was 12.8 +/- 3 kg (s.e.). In the 14 patients observed for 12-40 months, the mean weight decrease is 20 +/- 4 kg (range: 0-51). Apart from lesion of the oesophagus in one patient, there have been no operative complications. In one 45-year-old patient sudden death due to myocardial fibrosis occurred three years after the operation. Four patients have had short episodes of diarrhea, and vomiting has occurred in two patients who "tested the limits'. There is no evidence of gastric dilatation or ulcers, yet gastric stasis is prevalent. Three patients are failures, two not having reduced and the third regaining 28 of her initial 31 kg weight loss postoperatively. Five patients have participated in programs for weight reduction in which they claim greater ease in complying than before operation, due to the characteristic lack of hunger sensations in all of the successful patients. The mechanisms for weight reduction after vagotomy are not known, yet seem to involve other factors than delayed gastric emptying of solids. Longer follow-up is necessary for evaluation of this procedure in the treatment of morbid obesity.

Adolescent↗
PubMed1980

Effects of jejuno-ileal bypass on serum lipoproteins and glucose tolerance in severely obese patients.

Plasma insulin and blood glucose during oral glucose tolerance tests (OGTT) and serial determinations of serum lipoprotein fractions before and after jejuno-ileostomy in twenty severely obese (mean weight 137 kg) patients with a mean age of 29 years revealed statistically significant postoperative decreases in all parameters concomitant with a mean weight loss of 42 kg. Before the operation the patients were hyperinsulinaemic and had elevated blood glucose levels during OGTT though no patient had overt diabetes. Serum triglyceride and total cholesterol levels were normal but HDL cholesterol was significantly lower than in controls. During follow-up at least until body weight had levelled off a mean 19 months post-operative, there were statistically significant reductions in blood glucose and plasma insulin as well as serum total cholesterol and lipoprotein fractions. There was no change in serum triglycerides. The low preoperative HDL levels decreased. In a subgroup of these patients we have earlier shown postoperative increases in arterial tissue cholesterol coincident with the present significant decreases in HDL as well as in LDL cholesterol. Correlations between total cholesterol and lipoprotein cholesterol values in serum and blood glucose and plasma insulin at fast and during OGTT and changes in these parameters demonstrate interrelationships between lipid and carbohydrate metabolism. The bypass procedure most likely reduces the intestinal synthesis of HDL which in turn may increase hepatic cholesterol synthesis. Evidently there is a multifactorial aetiology for the low HDL levels in the severely obese both before and after jejuno-ileostomy.

Adult↗