Meal-feeding scheme: twenty years of research in Brazil

Naomi Shinomiya Hell was the first researcher to investigate the physiological adaptations to a meal-feeding scheme (MFS) in Brazil. Over a period of 20 years, from 1979 to 1999, Naomi's group determined the physiological and metabolic adaptations induced by this feeding scheme in rats. The group showed the persistence of such adaptations even when MFS is associated with moderate exercise training and the performance to a session of intense physical effort. The metabolic changes induced by the feeding training were discriminated from those caused by the effective fasting period. Naomi made an important contribution to the understanding of the MFS but a lot still has to be done. One crucial question still remains to be satisfactorily answered: what is the ideal control for the MFS?

Improved glycemic control by acarbose therapy in hypertensive diabetic patients: effects on blood pressure and hormonal parameters

A double-blind, randomized, placebo-controlled study was carried out on 44 hypertensive type 2 diabetic subjects previously treated by diet associated or not with sulfonylurea to assess the effects of acarbose-induced glycemic control on blood pressure (BP) and hormonal parameters. Before randomization and after a 22-week treatment period (100 to 300 mg/day), the subjects were submitted to a standard meal test and to 24-h ambulatory BP monitoring (ABPM) and had plasma glucose, glycosylated hemoglobin, lipid profile, insulin, proinsulin and leptin levels determined. Weight loss was found only in the acarbose-treated group (75.1 ± 11.6 to 73.1 ± 11.6 kg, P<0.01). Glycosylated hemoglobin decreased only in the acarbose group (6.4 ± 1.7 to 5.6 ± 1.9%, P<0.05). Fasting proinsulin decreased only in the acarbose group (23.4 ± 19.3 to 14.3 ± 13.6 pmol/l, P<0.05), while leptin decreased in both (placebo group: 26.3 ± 6.1 to 23.3 ± 9.4 and acarbose group: 25.0 ± 5.5 to 22.7 ± 7.9 ng/ml, P<0.05). When the subset of acarbose-treated patients who improved glycemic control was considered, significant reductions in diurnal systolic, diastolic and mean BP (102.3 ± 6.0 to 99.0 ± 6.6 mmHg, P<0.05) were found. Acarbose monotherapy or combined with sulfonylurea was effective in improving glycemic control in hypertensive diabetic patients. Acarbose-induced improvement in metabolic control may reduce BP in these patients. Our data did not suggest a direct action of acarbose on insulin resistance or leptin levels.

The control of deliberate waiting strategies in a stop-signal task

To inhibit an ongoing flow of thoughts or actions has been largely considered to be a crucial executive function, and the stop-signal paradigm makes inhibitory control measurable. Stop-signal tasks usually combine two concurrent tasks, i.e., manual responses to a primary task (go-task) are occasionally countermanded by a stimulus which signals participants to inhibit their response in that trial (stop-task). Participants are always instructed not to wait for the stop-signal, since waiting strategies cause the response times to be unstable, invalidating the data. The aim of the present study was to experimentally control the strategies of waiting deliberately for the stop-signal in a stop-task by means of an algorithm that measured the variation in the reaction times to go-stimuli on-line, and displayed a warning legend urging participants to be faster when their reaction times were more than two standard deviations of the mean. Thirty-four university students performed a stop-task with go- and stop-stimuli, both of which were delivered in the visual modality and were lateralized within the visual field. The participants were divided into two groups (group A, without the algorithm, vs group B, with the algorithm). Group B exhibited lower variability of reaction times to go-stimuli, whereas no significant between-group differences were found in any of the measures of inhibitory control, showing that the algorithm succeeded in controlling the deliberate waiting strategies. Differences between deliberate and unintentional waiting strategies, and anxiety as a probable factor responsible for individual differences in deliberate waiting behavior, are discussed.

Amniotic fluid amino acid levels in non-immune hydrops fetalis: a case-control study

In a prospective case-control study, we compared the amniotic fluid amino acid levels in non-immune hydrops fetalis (NIHF) and normal fetuses. Eighty fetuses underwent amniocentesis for different reasons at the prenatal diagnosis unit of the Department of Obstetrics and Gynecology, Faculty of Medicine, Dicle University. Forty of these fetuses were diagnosed with NIHF. The study included 40 women each in the NIHF (mean age: 27.69 ± 4.56 years) and control (27.52 ± 5.49 years) groups, who had abnormal double- or triple-screening test values with normal fetuses with gestational ages of 23.26 ± 1.98 and 23.68 ± 1.49 weeks at the time of sample collection, respectively. Amniotic fluid amino acid concentrations (intra-assay variation: 2.26-7.85%; interassay variation: 3.45-8.22%) were measured using EZ:faast kits (EZ:faast GC/FID free (physiological) amino acid kit; Phenomenex, USA) by gas chromatography. The standard for quantitation was a mixture of free amino acids from Phenomenex. The levels of 21 amino acids were measured. The mean phosphoserine and serine levels were significantly lower in the NIHF group, while the taurine, α-aminoadipic acid (aaa), glycine, cysteine, NH4, and arginine (Arg) levels were significantly higher compared to control. Significant risk variables for the NIHF group and odds coefficients were obtained using a binary logistic regression method. The respective odds ratios and 95% confidence intervals for the risk variables phosphoserine, taurine, aaa, Arg, and NH4 were 3.31 (1.84-5.97), 2.45 (1.56-3.86), 1.78 (1.18-2.68), 2.18 (1.56-3.04), and 2.41 (1.66-3.49), respectively. The significant difference between NIHF and control fetuses suggests that the amniotic fluid levels of some amino acids may be useful for the diagnosis of NIHF.

Alternative chromatographic system for the quality control of lipophilic technetium-99m radiopharmaceuticals such as [99mTc(MIBI)6]+

Knowledge of the radiochemical purity of radiopharmaceuticals is mandatory and can be evaluated by several methods and techniques. Planar chromatography is the technique normally employed in nuclear medicine since it is simple, rapid and usually of low cost. There is no standard system for the chromatographic technique, but price, separation efficiency and short time for execution must be considered. We have studied an alternative system using common chromatographic stationary phase and alcohol or alcohol:chloroform mixtures as the mobile phase, using the lipophilic radiopharmaceutical [99mTc(MIBI)6]+ as a model. Whatman 1 modified phase paper and absolute ethanol, Whatman 1 paper and methanol:chloroform (25:75), Whatman 3MM paper and ethanol:chloroform (25:75), and the more expensive ITLC-SG and 1-propanol:chloroform (10:90) were suitable systems for the direct determination of radiochemical purity of [99mTc(MIBI)6]+ since impurities such as99mTc-reduced-hydrolyzed (RH),99mTcO4- and [99mTc(cysteine)2]-complex were completely separated from the radiopharmaceutical, which moved toward the front of chromatographic systems while impurities were retained at the origin. The time required for analysis was 4 to 15 min, which is appropriate for nuclear medicine routines.

Effect of the implementation of the Hazard Analysis Critical Control Point (HACCP) prerequisite program in an institutional foodservice unit in Southern Brazil

The aims of this study were to investigate the hygienic practices in the food production of an institutional foodservice unit in Southern Brazil and to evaluate the effect of implementing good food handling practices and standard operational procedures using microbiological hygiene indicators. An initial survey of the general operating conditions classified the unit as regular in terms of compliance with State safety guidelines for food service establishments. An action plan that incorporated the correction of noncompliance issues and the training of food handlers in good food handling practices and standard operational procedures were then implemented. The results of the microbiological analysis of utensils, preparation surfaces, food handlers' hands, water, and ambient air were recorded before and after the implementation of the action plan. The results showed that the implementation of this type of practice leads to the production of safer foods.

Effect of standard and neutral-pH peritoneal dialysis solutions upon fibroblasts proliferation

Introduction: Continuous exposition of the peritoneal membrane to conventional dialysis solutions is an important risk factor for inducing structural and functional alterations. Objective: To compare in vitro mouse fibroblast NIH-3T3 cell viability after exposition to a neutral pH dialysis solution in comparison to cells exposed to a standard solution. Methods: Experimental study to compare the effects of a conventional standard or a neutral-pH, low-glucose degradation products peritoneal dialysis solution on the viability of exposed fibroblasts in cell culture. Both solutions were tested in all the commercially available glucose concentrations. Cell viability was evaluated with tetrazolium salt colorimetric assay. Results: Fibroblast viability was significantly superior in the neutral pH solution in comparison to control, in all three glucose concentrations (Optical density in nm-means ± SD: 1.5% 0.295 ± 0.047 vs. 0.372 ± 0.042, p < 0.001; 2.3% 0.270 ± 0.036 vs. 0.337 ± 0.051, p < 0.001; 4.25% 0.284 ± 0.037 vs. 0.332 ± 0.032, p < 0.001; control vs. neutral pH respectively, Student t Test). There was no significant difference in cell viability between the three concentrations of glucose when standard solution was used (ANOVA p = 0.218), although cell viability was higher after exposition to neutral pH peritoneal dialysis fluid at 1.5% in comparison to 2.3 and 4.25% glucose concentrations (ANOVA p = 0.008: Bonferroni 1.5% vs. 2.3% p = 0.033, 1.5% vs. 4.25% p = 0.014, 2.3% vs. 4.25% p = 1.00). Conclusion: Cell viability was better in neutral pH dialysis solution, especially in the lower glucose concentration. A more physiological pH and lower glucose degradation products may be responsible for such results.