Orally administered whey proteins have comparable effect on C-peptide secretion in healthy subjects as standard C-peptide stimulation tests.

Our study compared total C-peptide secretion after administration of whey proteins and whey proteins in combination with glucose with results of classical tests assessing beta cell function in the pancreas of healthy individuals. Eight young, healthy (7 males, 1 female; aged 20-26 years), non-obese (BMI: 17-25.9 kg/m²) participants with normal glucose tolerance underwent six C-peptide secretion tests. Three secretion tests measured C-peptide response to orally administered substances: whey proteins only (OWT), whey proteins with glucose (OWGT) and glucose only (OGTT); while three secretion tests measured C-peptide response to intravenously administered substances: arginine (AST), glucagon (GST) and glucose (IVGTT). OWT stimulated a greater (93 %, p<0.05) C-peptide response than AST and a 64 % smaller response (p<0.05) than OGTT. OWT also showed lower variability (p<0.05) in C-peptide responses compared to OWGT and OGTT. The greatest total C-peptide response was induced by OWGT (36 % higher than glucose). OWT consistently increased C-peptide concentrations with lower individual variability, while insignificantly increasing glucose levels. Results of this study suggest that both dietology and beta-cells capacity testing could take advantage of the unique property of whey proteins to induce C-peptide secretion.

Short-term dietary intake of C18:1 trans fatty acids decreases the function of cellular immunity in healthy young men.

AIM: In this study, we tested the impact of short-term intake of increased amounts of C18:1 trans fatty acids (TFAs) on parameters of cellular and humoral immunity in healthy young men. METHODS: Twenty-seven healthy young men were subsequently exposed to a standard diet for 7 days and an experimental TFA-enriched diet for 4 days. The mean energy content of these diets was 2,453 and 2,455 kcal/day, with 10, 35 and 55% of energy from proteins, fats and carbohydrates, respectively. Standard diet contained about 0.8 g and experimental diet 10.4 g TFAs. Plasma levels of C18:1 TFAs and immunological parameters were measured. RESULTS: The 4-day increased consumption of C18:1 TFAs led to a significant decrease in mitogen-induced CD69 expression on CD8+ T cells as well as decreased phagocytic activity on neutrophils. After returning to the participants' habitual diet (1 week after the end of the experimental diet), we observed a significant decrease in the mean level of circulating immune complexes. Concentrations of plasma immunoglobulins remained unchanged throughout the study. CONCLUSIONS: Acute impact of higher dietary C18:1 TFA intake on phagocytosis and cell-mediated immunity seems to be suppressive. This finding differs from results describing proinflammatory effects associated with long-term exposure to TFAs.

A comparison of the influence of a high-fat diet enriched in monounsaturated fatty acids and conventional diet on weight loss and metabolic parameters in obese non-diabetic and Type 2 diabetic patients.

AIMS: The aim of our study was to compare the influence of a hypocaloric, high-fat diet enriched with MUFA (M) and conventional diet (C) on weight loss and metabolic parameters in obese non-diabetic and obese Type 2 diabetic subjects over a 3-month period. It was our hypothesis that the enriched diet would be more effective in decreasing blood glucose and glycated haemoglobin (HbA(1c)) than the control diet. METHODS: Twenty-seven Type 2 diabetic patients (54.5 +/- 3.5 years; DM), treated with diet or oral glucose-lowering agents, and 31 obese non-diabetic subjects (53.6 +/- 3.5 years; OB) were randomized to M or C. Individual calculations of energy requirements were based on the formula: [resting energy expenditure (REE) x 1.5] - 600 kcal. Subjects were assessed by a dietitian every 2 weeks and by a physician every month. Statistical analyses were carried out between the four groups--DM/M, DM/C, OB/M and OB/C--using pair Student's test and anova. RESULTS: After 3 months, body weight, waist-hip ratio, total body fat, levels of C-peptide, triglycerides and homeostasis model assessment (HOMA) decreased in all four groups (P < 0.01). However, fasting blood glucose and HbA(1c) decreased (P < 0.01) and high-density lipoprotein cholesterol increased significantly only in the DM/M group (P < 0.05). In general, M was well tolerated. CONCLUSIONS: Individualized M and C diets were successful in improving metabolic and anthropometric parameters in both the obese non-diabetic and the Type 2 diabetic subjects. Although the superiority of the higher fat diet did not reach statistical significance, the decline in blood glucose and HbA(1c) in the Type 2 diabetic group on M was encouraging.

Can bioimpedance determine the volume of distribution of antibiotics in sepsis?

The relationship between the volume of distribution, assessed according to the two-compartmental pharmacokinetic model, and extracellular water estimated by bioimpedance was studied in mechanically ventilated patients with sepsis and capillary leak. A prospective observational study was performed in a twenty-bed general intensive care unit in the university hospital. Patients received either vancomycin (n = 16) or netilmicin (n = 12) for more than 48 hours. Those with ascites, pleural effusion, on renal replacement therapy or with haemodynamic instability were excluded. Serum concentrations of drugs were taken for pharmacokinetic analysis before, 1 hour and 4 hours after the 30 minute infusion. Bioimpedance measurement was performed at the time of the third sampling. The protocol was repeated after 24 hours. Fluid balance during the 24 hour interval was recorded. Extracellular water was increased and represented 45.6 to 46.6% of total body water Fluid balance correlated with the change of extracellular water (r = 0.82, P < 0.0001) and total body water (r = 0.74, P < 0.0001). Volumes of distribution of vancomycin (0.677 +/- 0.339 l/kg) and netilmicin (0.505 +/- 0.172 l/kg) were increased compared to normal values. A correlation was demonstrated between volume of distribution (Vd(area)) of vancomycin and extra cellular water/total body ratio (r = 0.70, P < 0.0001). The central compartment distribution volume (V1) of netilmicin correlated with extracellular water/total body water ratio (r = 0.60, P < 0.003). Serum concentrations above the recommended therapeutic range were detected in 81.2% of patients on vancomycin and in 50% of patients on netilmicin. Increased volumes of distribution can be estimated by the bioimpedance measurements but are not associated with requirements for higher dosage of the glycopeptide or aminoglycoside antibiotics.

[Diabetic diet and reduction diet are worthy of a basic discussion of their paradigms]. / Diabetická i redukcní dieta zasluhují základní diskusi o svých paradigmatech.

Present knowledge of etiopathogenesis of various types of diabetes postulate substantial differences between type I and type II diabetes. Whereas type I diabetes results from autoimmune destruction of pancreatic B-cells and subsequent absolute lack of insulin, type II diabetes is connected with insulin resistance and frequently with rather relative lack of sometimes absolutely elevated plasmatic insulin. From the viewpoint of the diet therapy an access to both types of diabetes fairly differs. Whilst in type I diabetes it is necessary to find out relationship among preprandial insulin dose, received carbohydrates, and expected physical activity soon after meal, treatment of type II diabetes is based in an effort to influence insulin resistance and the whole metabolic syndrome. Therefore, on one side carbohydrates with low glycemic index and plenty of fibers are administered in a diet and on the other side monoenic and polyenic fatty acids are preferred to saturated fatty acids and trans fatty acids are continuously reduced in a diet. Of course, diets for patients with overweight and for obese patients are low energy. From the viewpoint of the current structure of the diabetic diets it is suitable to differentiate diets for patients with type I and type II diabetes. Instead of the use of a fix proportion of nutrients we have to discuss diets with regard to a qualitative composition of fatty acids in fats, glycemic index of saccharides, and an amount of fibers in the diet.

Effect of diphenylhydantion on cortical epileptogenic foci in the rat.

In acute experiments we studied the effect of diphenylhydantoin (DPH, 60 mg/kg i.p.) on the activity of cortical penicillin foci in 81 male rats. DPH reduced the discharge frequencies (measured by means of histograms of the intervals between adjacent discharges) and limited the projection of the discharges into non-primary cortical areas. The results for the administration of DPH before formation and after stabilization of the focus were qualitatively the same. DPH statistically significantly slowed down synchronization of the activity of two symmetrical cortical foci, but did not affect the progress of the synchronization of two asymmetrical foci, which was also very slow in the controls. DPH did not inhibit the possibility of triggering focal discharges by peripheral nerve stimulation. A detailed evaluation of focal activity allows the anti-epileptic effect of DPH to be demonstrated even in a model as potent as the penicillin focus in animals without general anaesthesia.