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Biomedical subjects

N Vaisman

Publications and source records attributed to N Vaisman.

At least 55 records · Page 3Linked to original sources
PubMed1990

Tumour necrosis factor production and cell-mediated immunity in anorexia nervosa.

Fourteen patients with anorexia nervosa (AN) were studied for the production of tumour necrosis factor (TNF), the activation of the interferon (IFN) system and cell-mediated cytotoxicity (CMC) and the results were compared with 16 age-matched healthy women. AN patients had significantly increased spontaneous TNF production by peripheral blood mononuclear cells (PBMC) in vitro (16 +/- 5 U/ml versus 4 +/- 3 U/ml in the control group; P less than 0.05), although no TNF was detectable in the plasma from either group. TNF production in vitro, following stimulation of PBMC by phytohaemagglutinin (PHA) or tumour cells, was similar in AN patients and controls; however, lipopolysaccharide (LPS) induced TNF production was found to be lower in AN (P less than 0.1). CMC was significantly lower in AN patients (4 +/- 2 versus 10 +/- 3 in controls, expressed as lytic units/10(6) cells; P less than 0.05), but no difference could be found between AN and controls in IFN activity as reflected by the level of the IFN-induced enzyme 2'-5' oligoadenylate synthetase (2-5A) in PBMC. Beta-endorphins in the plasma were higher in the AN group (P less than 0.05) but these levels could not be correlated to those of IFN, CMC or TNF. Defective CMC and increased TNF production by PBMC in patients with anorexia nervosa may possibly result from the nutritional deficiencies and neuroendocrine abnormalities associated with the disease, and may contribute to the pathophysiology of AN.

Adolescent↗
PubMed1990

Effect of moderate semi-starvation on plasma lipids.

The effect of a daily intake of 200 kcal for 6 days on blood lipid levels of normal and obese subjects was examined. Subjects exhibited a decrease in body weight of 5.9 percent. Plasma glucose levels decreased with no change in insulin levels. FFA and cholesterol did not change significantly with the low caloric intake. Triglyceride and phospholipid concentrations, elevated in obese subjects before the dietary period, decreased significantly with low caloric intake. In contrast no significant changes were observed in triglycerides or phospholipids in normal subjects. Serum uric acid increased during diet in normal but not in obese subjects. These results show different patterns of changes in plasma lipids in normal and obese subjects on very low caloric intake and raise the possibility of differences in utilization of lipid and protein stores, and may also hint at a role for phospholipids in energy metabolism. Very low calorie and carbohydrate diets may be beneficial for weight reduction in obese subjects without increasing blood lipids.

Adult↗
PubMed1989

Energy metabolism in children with newly diagnosed acute lymphoblastic leukemia.

The effect of tumor burden in acute lymphoblastic leukemia on resting energy expenditure, thermic effect of food, and substrate utilization was investigated with open-circuit indirect calorimetry after an overnight fast. Nine patients (six females, three males) ages 6.5 to 15.8 y were studied. Patients were divided into two groups according to their tumor burden at diagnosis (i.e. white cell count, presence or absence of mediastinal mass, or massive organomegaly). The patients with a greater tumor burden had increased energy expenditure. Their resting energy expenditure returned to normal in response to chemotherapy. These results must be interpreted with caution due to the small patients numbers (high tumor burden n = 3; low tumor burden n = 6). Substrate utilization was altered by chemotherapy with an increase in carbohydrate utilization and a decrease in fat oxidation (p less than 0.009). The magnitude of the thermic effect of food tended to increase on treatment (p less than 0.016). Inasmuch as most chemotherapy programs for children last up to 3 y, we believe it is important that the effects of chemotherapy on intermediary metabolism be studied, particularly in relationship to any possible permanent effects on growth and development.

Adolescent↗
PubMed1988

Energy expenditure and body composition in patients with anorexia nervosa.

Blood biochemistry, body composition, and resting energy expenditure were studied in 25 patients with anorexia nervosa admitted to hospital during a period of 18 months. The patients' ages ranged from 12.9 to 17.2 years, and the abnormal feeding history from 3 to 12 months. Blood chemistry values were in the normal range, but fat body mass and lean body mass were reduced and extracellular water volume was expanded beyond normal values. Resting energy expenditure was reduced to 49% to 91% of values predicted by the Harris-Benedict equations. Substrate use after overnight fast indicated an abnormally high use of carbohydrates. Significant correlations were found between extracellular water volume and triceps skin-fold thickness, mid-arm muscle circumference and lean body mass, and substrate use and weight loss as a percentage of initial weight. We suggest that these simple anthropometric measurements can be used to assess and monitor the refeeding of patients with anorexia nervosa.

Adolescent↗
PubMed1988

Changes in body composition during refeeding of patients with anorexia nervosa.

Changes in body composition were studied in 13 girls with anorexia nervosa before and during 2 months of refeeding. Fat body mass and fat-free body mass were derived from skin-fold measurements. Total body potassium was measured by whole body counter, and intracellular water was calculated from it. Extracellular water was measured as the bromide space after oral bromide administration. A gradual increase was noted in weight, fat body mass, fat-free body mass, and total body potassium during refeeding. Extracellular water was expanded on admission and increased in all patients in the first weeks of treatment; later it fell to normal. Most of the changes in fat-free body mass over the first weeks of refeeding could be accounted for by an expansion in extracellular water. Particular care must therefore be taken with fluid balance during the first few weeks of refeeding.

Adipose Tissue↗
PubMed1988

The effect of a weight-reducing diet on the nitrogen metabolism of obese adolescents.

Rates of whole body amino nitrogen flux were measured in 16 obese adolescents undergoing weight reduction with a high protein low energy diet. The subjects received approximately 2.5 g of animal protein per day per kilogram ideal body weight and maintained nitrogen balance throughout the 18 days on the diet. Flux rates were calculated separately from the cumulative excretion of 15N in urinary ammonia and urea following the administration of a single dose of [15N]glycine. The pattern of 15N label appearance in urinary ammonia and urea nitrogen was followed for 72 h after the administration of [15N]glycine. Significant amounts of label continued to be excreted in both urinary ammonia and nitrogen for 36-48 h after label administration. The weight-reducing diet accelerated 15N cumulative excretion in urinary urea, but not in ammonia nitrogen compared with the control diet. Whole body nitrogen flux rates increased rapidly and significantly on the diet. Using the urea end product, this increase was evident on the 4th diet day, but not by the 7th or subsequent days. On the other hand, using the ammonia end product, flux rate increased markedly (p less than 0.0001) and remained elevated throughout the whole study. Our results demonstrate adaptive changes in whole body amino-nitrogen metabolism in response to the reducing diet. Different patterns of change are seen depending upon whether an ammonia or a urea end product is used. Our data thus add to the evidence for compartmentation of the body's amino-nitrogen pools.

Adaptation, Physiological↗
PubMed1988

Changes in body composition in children following kidney transplantation.

Rapid weight gain has been observed following kidney transplantation. To determine the accompanying changes in body composition, we studied 8 patients (7 females, 1 male) aged 3-17.5 years who underwent renal transplantation. Body composition measurements included weight, height, triceps skinfold thickness, total body potassium, total body water, and extracellular water. Excessive weight gain was observed in most of the patients. Weight as a percentage of ideal weight for height increased from 96.0 +/- 13.8 to 116.3 +/- 13.0% (p less than 0.01). This was accompanied by a gain in fat mass in the first 3 months and a subsequent increase in lean body mass in the next 3 months. Extracellular water was increased before transplantation (32.9 +/- 6.5% of body weight) and returned to normal (27.3 +/- 8.6%) 3 months after transplantation (p less than 0.01). The weight gain following kidney transplantation in children resulted mainly from increases in adipose tissue and lean body mass, and was not related to water retention.

Adolescent↗
PubMed1987

Energy expenditure of patients with cystic fibrosis.

Resting energy expenditure was measured by open-circuit indirect calorimetry in 71 patients, aged 8.9 to 35.5 years, with cystic fibrosis who had no recent history of acute lung infection. Pulmonary function and nutritional status were studied simultaneously. In most patients, resting energy expenditure was above normal (range 95% to 153% of predicted values for age, sex, and weight as derived from the Harris Benedict equations), and was negatively correlated with pulmonary function (P less than 0.01) and nutritional status (P less than 0.01) when expressed as a percentage of body fat. Pulmonary status was positively correlated with nutritional status (P less than 0.01). We conclude that resting energy expenditure in patients with cystic fibrosis exceeds normal values and that the increase correlates with a deterioration in lung function and nutritional status.

Adolescent↗
PubMed1987

Pharmacokinetics of inhaled salbutamol in patients with cystic fibrosis versus healthy young adults.

We studied the disposition of inhaled salbutamol in adolescents with cystic fibrosis (CF) and compared it with the pharmacokinetics of the drug given by the intravenous and inhaled routes in healthy adults. After inhalation of salbutamol, CF patients had a significantly larger area under the concentration-time curve derived from amounts of drug in the systemic circulation. The differences in serum concentration of salbutamol were not reflected in differences in change of heart rate. We conclude that the rate and extent of pulmonary absorption of inhaled salbutamol in patients with CF differ from those in healthy adults.

Administration, Inhalation↗
PubMed1987

Comparison of oral and intravenous administration of sodium bromide for extracellular water measurements.

Extracellular water (ECW) is a component of body composition and an indicator of nutritional status. Although bromide has been used to measure ECW, no data regarding serial measurements are available. We attempted to validate giving bromide orally and to determine whether serial measurements of ECW are possible. Seven healthy adult volunteers were studied. Each received 1 cc 3% NaBr solution per kg body weight once intravenously and 3 times orally over 6 wk. Bromide concentrations were determined by neutron activation. ECW did not differ significantly at 2, 3, or 4 h after drug administration although there was a small but significant difference between modes of administration (p = less than 0.05). With repeated oral doses the estimate of ECW was unchanged; thus, oral bromide can be used for serial determination of ECW.

Administration, Oral↗
PubMedDate not supplied

The effect of different nutritional states on cell-mediated cytotoxicity.

We have studied the effect of acute short-term starvation (in 9 patients) and of prolonged caloric deprivation (in 10 patients with anorexia nervosa), on cell-mediated cytotoxicity (CMC). CMC became severely depressed after six days on a very low caloric diet (1.2 +/- 1.4 vs. 7.0 +/- 2.9 lytic units/10(6) cells; P less than 0.01). CMC was also low in our patients with anorexia nervosa compared to a matched control group (3.3 +/- 1.7 vs. 10.0 +/- 3.0 lytic units/10(6) cells; P less than 0.01) and increased in most of the patients studied (five cases) after the first 3-4 weeks of refeeding in correlation with weight gain. Dietary deprivation may lead to a significant impairment in cell-mediated cytotoxicity, which appears to be reversible after refeeding.

Adolescent↗
PubMedDate not supplied

Comparison of nitrogen utilization of two elemental diets in patients with Crohn's disease.

Energy, nitrogen absorption, and nitrogen utilization of two commercial elemental diets, Vivonex and Vital, were compared in 10 teenage boys and girls with Crohn's disease. The diets were given in random order as overnight feedings and were the sole source of nutrients for two consecutive periods of 3 weeks each. Urine and stools were collected for 48 h at the end of each 3-week period. Energy absorption was slightly better on Vivonex (p less than 0.05), although 95-100% of energy was absorbed with both formulas. Nitrogen absorption was not different for the two formulas, but nitrogen utilization was significantly better on Vital (28.6 +/- 12.9% versus 9.7 +/- 17.7%, p less than 0.01). This difference may be attributable to the different concentrations of sulfur-containing and aromatic amino acids in the two formulas.

Absorption↗