Impact of cyclodextrins on postprandial glycemia: evaluation in experimental animal model using the real-time continuous glucose monitoring system.

The impact of cyclodextrins (CDs) on postprandial glycemic response employing the real-time continuous glucose monitoring system (RT-CGMS) was investigated. For this purpose, α-CD, ß-CD, γ-CD, HP-ß-CD, curdlan, and dextrin at doses of 10 and 100 mg/kg were orally administered in rats. The RT-CGMS was efficient to evaluate the impact of CDs on postprandial glycemia. The results showed that α-CD, ß-CD, dextrin, and curdlan did not reduce the glycemic response after the administration of starch. In contrast, the HP-ß-CD (100 mg/kg) attenuated the rise in glycemia. Moreover, the γ-CD blunts the postprandial glycemic excursion at doses of 10 and 100 mg/kg. Therefore, γ-CD could attenuate the rise in glycemia promoted by oral administration of starch. Considering that the treatment of postprandial hyperglycemia is necessary to prevent type 2 diabetes, this study opens the perspective of better control of postprandial glycemia by the addition of γ-CD in food.

Infliximab treatment prevents hyperglycemia and the intensification of hepatic gluconeogenesis in an animal model of high fat diet-induced liver glucose overproduction

The effect of infliximab on gluconeogenesis in an animal model of diet-induced liver glucose overproduction was investigated. The mice were treated with standard diet (SD group) or high fat diet (HFD group). HFD group were randomly divided and treated either with saline (100 µl/dose, ip, twice a day) or infliximab (10 µg in 100 µl saline per dose, ip, twice a day, i.e., 0.5 mg/kg per day). SD group also received saline. The treatment with infliximab or saline started on the first day of the introduction of the HFD and was maintained during two weeks. After this period, the mice were fasted (15 h) and anesthetized. After laparotomy, blood was collected for glucose determination followed by liver perfusion in which L-alanine (5 mM) was used as gluconeogenic substrate. HFD group treated with saline showed higher (p < 0.05) liver glucose production from L-alanine and fasting hyperglycemia. However, these metabolic changes were prevented by infliximab treatment. Therefore, this study suggested that infliximab could prevent the glucose overproduction and hyperglycemia related with glucose intolerance and type 2 diabetes.

Coexistence of insulin resistance and increased glucose tolerance in pregnant rats: a physiological mechanism for glucose maintenance.

AIM: The contribution of insulin resistance (IR) and glucose tolerance to the maintenance of blood glucose levels in non diabetic pregnant Wistar rats (PWR) was investigated. MAIN METHODS: PWR were submitted to conventional insulin tolerance test (ITT) and glucose tolerance test (GTT) using blood sample collected 0, 10 and 60 min after intraperitoneal insulin (1 U/kg) or oral (gavage) glucose (1g/kg) administration. Moreover, ITT, GTT and the kinetics of glucose concentration changes in the fed and fasted states were evaluated with a real-time continuous glucose monitoring system (RT-CGMS) technique. Furthermore, the contribution of the liver glucose production was investigated. KEY FINDINGS: Conventional ITT and GTT at 0, 7, 14 and 20 days of pregnancy revealed increased IR and glucose tolerance after 20 days of pregnancy. Thus, this period of pregnancy was used to investigate the kinetics of glucose changes with the RT-CGMS technique. PWR (day 20) exhibited a lower (p<0.05) glucose concentration in the fed state. In addition, we observed IR and increased glucose tolerance in the fed state (PWR-day 20 vs. day 0). Furthermore, our data from glycogenolysis and gluconeogenesis suggested that the liver glucose production did not contribute to these changes in insulin sensitivity and/or glucose tolerance during late pregnancy. SIGNIFICANCE: In contrast to the general view that IR is a pathological process associated with gestational diabetes, a certain degree of IR may represent an important physiological mechanism for blood glucose maintenance during fasting.

Comparison of the bacteriological quality of tap water and bottled mineral water.

The bacteriological quality of tap water from municipal water supplies, 20-L bottles of mineral water from water dispensers and samples collected from new 20-L bottles of mineral water were comparatively studied. Total coliforms, termotolerant coliforms, Escherichia coli, fecal streptococci, Pseudomonas aeruginosa, Staphylococcus spp. and heterotrophic plate count were enumerated. The results showed that 36.4% of the tap water samples from municipal water systems and 76.6% of the 20-L bottles of mineral water from water dispensers were contaminated by at least one coliform or indicator bacterium and/or at least one pathogenic bacterium. The bacteriological quality of municipal tap water is superior when compared with the 20-L bottles of mineral water collected from water dispensers and samples collected from new 20-L bottles of mineral water before installation in the dispensers. This highlights the need for an improved surveillance system for the bottled water industry. For the municipal water systems, it is recommended to perform the Pseudomonas enumeration periodically, in addition to the routine data collected by most systems.

Adaptaçäo dos métodos da contagem na gota e da alça calibrada para a contagem de lactobacilos e estreptococos do grupo mutans da saliva / Adaptation of drop-plate and calibrated loop methods for enumerating lactobacilli and mutans streptococci group of saliva

Apesar de se encontrar amplamente reconhecido a importância do emprego dos testes de contagem de lactobacilos e de estreptococos do grupo mutans da saliva para avaliar o risco de pacientes à cárie dentária, no Brasil, por fatores técnicos e econômicos estes testes säo pouco utilizados na prática odontológica e também pouco divulgados junto aos laboratórios de análises clínicas. Com objetivo de investigar uma técnica simplificada para quantificar estes microrganismos na saliva, comparamos as adaptaçöes das técnicas da contagem na gota e da alça calibrada com os métodos padröes de contagem de lactobacilos e estreptococos do grupo mutans. Foram analisados 30 espécimes de saliva estimulada, obtidos de 30 indivíduos que apresentaram alto (n = 20), médio (n = 6) e baixo (n = 4) risco de cárie. Näo houve diferenças significativas entre os resultados da contagem (p>0,05), indicando que as adaptaçöes das técnicas da contagem na gota e da alça calibrada descritas em nosso estudo podem ser empregadas no laboratório de análises clínicas como uma alternativa simplificada e de baixo custo para a contagem de lactobacilos e de estreptococos do grupo mutans da saliva

Esterilizaçäo rápida de cones de guta-percha por glutaraldeído / Sterilization of gutta-percha cones with glutaraldehyde

Estudou-se, in vitro, o efeito bactericida e esporocida de cinco preparaçöes líquidas de glutaraldeído a 2 por cento (Glutaron II, Cidex 28, Glutalabor, Banicide e Anti-G-Plus). Utilizaram-se cones de guta-percha (nacional e estrangeiro) artificialmente contaminados com suspensöes de amostras de Staphylococcus aureus e Escherichia coli e de esporos de Bacillus subtilis. As soluçöes apresentaram açäo microbicida para as amostras de S. aureus e de E. coli após os tempos de contato de 1, 5, 10 e 15 min. O efeito esporacida nos cones nacionais (Dentsply)ocorreu em 10 min e, nos cones estrangeiros (Diadent), após 10 min (Cidex, Banicide e Anti-G-Plus) e 15 min (Glutaron e Glutalabor). As soluçöes de glutaraldeído testatas podem ser utilizadas na prática endodôntica pra a descontaminaçäo rápida de cones de guta-percha

Procedimento simplificado para detecção de bacteriúria significativa / Simplified procedure for the detection of significative bacteriuria

O estudo comparativo entre o exame microscópico de 0,01 mL de urina, utilizando-se alça calibrada de 10mL, com a clássica técnica da gota (0,05mL) de urina não centrifugada corada pelo Gram, para detecção de bacteriúria significativa em pacientes com suspeita de infecção urinária, mostrou 100% de correlação. Como método de referência foi realizada em paralelo a cultura quantitativa dos 300 espécimes de urina analisados no presente estudo, empregando-se a técnica da alça calibrada. A prevalência de Culturas positivas (≥ 105 UFCV/mL) foi de 27,3% (82/300), ocorrendo predomínio de bacilos Gram negativos entéricos entre os patógenos urinários isolados. Não foram encontradas diferenças significativas (p>0,05) em relação a média do número de bactérias observadas em 10, 20, 30, 40 e 50 campos microscópicos, dos espécimes de urina positivos, examinados pelas duas técnicas de microscopia. Foram: sensibilidade 98,78%; especificidade 98,62%; valor preditivo positivo 96,42% e valor preditivo negativo 99,53%; confirmando a indicação deste procedimento na prática bacteriológica como método de triagem de infecção urinária. Os resultados demonstraram que a técnica da alça (10mL) pode ser usada como uma alternativa a tradicional técnica da gota (50mL) para detecção de bacteriúria significativa, apresentando como vantagem maior rapidez e simplicidade de execução. Como critério de exame microscópico positivo recomenda-se a leitura de 10 campos microscópicos e a presença de ≥ 2 microorganismos por campo microscópico de imersão.