Stimulation of enzyme secretion from isolated pancreatic acini by Clostridium difficile toxin B

Exposure of isolated rat pancreatic acini to increasing concentrations (10 ng - 800 ng/ml) of toxin B from Clostridium difficile produced a biphasic effect on the rate of secretion of amylase, trypsinogen, and chymotrypsinogen. Whereas doses of toxin B from 10-30 ng/ml increased enzyme secretion by 15-20%, doses between 30 ng and 60 ng/ml showed a regression of this effect, whereafter the rate of secretion of amylase, trypsinogen, and chymotrypsinogen increased with increasing concentrations of the toxin. Toxin B concentration of 800 ng/ml enhanced amylase, trypsinogen and chymotrypsinogen secretion by 119%, 185% and 195%, respectively, when compared with the basal level. Stimulation of enzyme secretion by toxin B was not affected by the presence of either actinomycin-D or cycloheximide, at a concentration which inhibited acinar RNA or protein synthesis by 80-90%. Although toxin B as well as CCK8, carbachol and secretin by themselves caused significant stimulation in amylase, trypsinogen and chymotrypsinogen secretion from isolated pancreatic acini, toxin B together with either CCK8, carbachol or secretin produced no further augmentation in enzyme secretion than what was observed with the secretagogues alone. It is concluded that toxin B of Cl. difficile exerts a direct effect on pancreatic acinar cells as evidenced by stimulation of enzyme secretion.     

Concentration and distribution pattern of selected micronutrients in preterm and term milk from urban Brazilian mothers during early lactation

The purpose of this study was to assess the concentration and binding pattern of zinc, iron, folate and vitamin B12 in milk of Brazilian women of low socioeconomic status giving birth at term or preterm, during early lactation. Protein, fat, total solids and ash concentrations were also determined. Protein and zinc concentrations decreased significantly as lactation proceeded whereas milk fat and folate increased with the lactation period. Total solids, ash, iron and vitamin B12 remained unchanged. Zinc was present mainly in the whey fraction while less than half of the total iron was present in this fraction, with no significant change due to stage of lactation. Unsaturated folate and vitamin B12 binding capacities and percentage of saturation of the folate binding protein increased with the stage of lactation. The vitamin B12 binding protein was highly unsaturated in all samples. There was no significant difference between term and preterm samples in the parameters investigated. Correlation analysis between milk components indicated significant relationships between total solids and fat, total zinc and whey zinc, folate and total folate binding capacity, unsaturated and total folate binding capacity, and unsaturated and total B12 binding capacity. In general, the nutrient concentrations found in this study are in good agreement with published data on milk composition of women from developed countries, with the possible exceptions of folate, which was lower, and iron, which was higher. The correlation of folate concentration with its binding protein found in this work supports the hypothesis of a regulatory role for folate levels in milk exerted by the folate binding protein in the mammary gland.     

Stability of risk factors for cardiovascular diseases in Portuguese children and adolescents from the Porto area.

An important aspect of preventive medicine is to identify subjects at risk as soon as possible, so preventive strategies can be introduced at early ages. The justification for this strategy is twofold: firstly, the assumption that children maintain a particular high value of a risk factor for disease throughout life; and secondly, the assumption that lowering the level of the risk factor in early life will have a greater impact on the disease than will risk factor changes in later life. In epidemiology the analysis of such factors over time is referred to as tracking. Tracking analysis has been applied to risk factors for cardiovascular diseases (CVD) in pediatric years. The aims of this study were: I) to analyze the stability of biological risk factors [high blood pressure (BP), high percentage of fat mass (%FM) and high total cholesterol (TC)] and lifestyle risk factors [low physical activity index (PAI)] in isolation; and II) to analyze the stability of zero, one, two or three biological risk factors. There were two evaluations in 692 children and adolescents (325 boys and 367 girls), aged between 8 and 15 years. The quartiles, adjusted for age and gender, were the criterion used to identify subjects with biological risk factors (fourth quartile) and with lifestyle risk factors (first quartile) for CVD. The stability was calculated through the relative frequency of subjects who maintained or changed quartile between the two evaluations. There is stability for biological risk factors as well as for behavioral and/or lifestyle risk factors. However, the highest stability is seen in biological risk factors.     

Effects of retinol on proliferation, cell adherence and extracellular matrix synthesis in a liver myofibroblast or lipocyte cell line (GRX).

We have studied the effect of retinol on an established murine cell line (GRX), representative of liver connective tissue cells. This cell line has myofibroblast characteristics; under retinol treatment it is induced into the lipocyte (Ito-cell) phenotype. Retinol decreased the proliferation rate in the entire cell population. It increased cell adherence to the substrate, which was correlated with the increased secretion of fibronectin. Collagen secretion was specifically decreased, whilst the total protein secretion remained stable. Heparan sulphate was decreased in the pericellular compartment, but other glycosaminoglycans were not affected by retinol treatment. Modulations of pericellular components induced by retinol may alter the relations among liver mesenchymal cells, and may be related to vitamin-A-induced modifications of the homoeostasis of hepatic connective tissue and hepatic fibrosis.     

Prophylactic antibiotherapy in urological surgery

The aim of prophylactic antibiotic therapy in urological surgery is the prevention of local or systemic infections. The authors treated 100 patients prophylactically; 62 were treated with amikacin and 38 with cefotaxime. Of the 62 patients treated with amikacin, 18 had infectious complications. Of the 38 patients treated with cefotaxime, ten had infectious complications. We conclude that in the Hospital do Desterro the incidence of infectious complications is high, despite antibiotic prophylaxis.Das Ziel der Antibiotikaprophylaxe bei urologischen Operationen ist die Verhinderung von lokalen und systemischen Infektionen. Die Autoren führten bei 100 Patienten eine Prophylaxe durch; 62 Patienten wurden mit Amikacin und 38 Patienten mit Cefotaxim behandelt. Von den 62 mit Amikacin behandelten Patienten hatten 18 und von den 38 mit Cefotaxim behandelten Patienten hatten zehn Patienten infektiöse Komplikationen. Daraus ergibt sich, daß trotz Antibiotikaprophylaxe das Auftreten infektiöser Komplikationen im Hospital do Desterro hoch ist.

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Dr.Calais da Silva's discussion could not be presented during the meeting because of an unforeseen event, but the kindly provided us with this discussion.     

Wilson's disease in children: 37-year experience and revised King's score for liver transplantation.

Wilson's disease (WD) is a rare liver-based disorder of copper metabolism. Prognostic criteria described by our group in 1986 to predict death without transplantation have not been universally validated. The clinical features of 88 children were reviewed, retrospectively in 74 and prospectively in 14. Data from the retrospectively recruited patients that died or survived on long-term chelation were used to evaluate the validity of our old scoring system and to devise a new prognostic index, then assessed in the 14 prospectively recruited patients. Using the old scoring system, 5 children scoring > or = 7, the cutoff value for death without transplantation, survived, whereas 4 scoring < or = 7 died (sensitivity 87% and specificity 90%). A new index based on serum bilirubin, international normalized ratio, aspartate aminotransferase (AST), and white cell count (WCC) at presentation identified a cutoff score of 11 for death and proved to be 93% sensitive and 98% specific, with a positive predictive value of 88%. When the new index was evaluated prospectively in 14 patients, it predicted the need for transplantation in only the 4 who required it, although 1 child with a score of 11 survived on medical treatment. In conclusion, the new Wilson Index is more sensitive and specific in predicting mortality without transplantation than the old scoring system, but needs to be validated in a larger number of patients.