133 research outputs found

    Expression of Guanylyl Cyclase (GC)-A and GC-B during Brain Development: Evidence for a Role of GC-B in Perinatal Neurogenesis

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    Atrial (ANP) and C-type (CNP) natriuretic peptide generate physiological effects via selective activation of two closely related membrane receptors with guanylyl cyclase (GC) activity, known as GC-A and GC-B. As yet, however, the discrete roles for ANP/GC-A vs. CNP/GC-B signaling in many mammalian tissues are still poorly understood. We here used receptor affinity labeling and GC assays to characterize comparatively GC-A/GC-B expression and functional activity during rat brain development. The study revealed that GC-B predominates in the developing and GC-A in the adult brain, with regional differences each between cerebral cortex, cerebellum, and brain stem. Whereas GC-A levels nearly continuously increase between embryonal d 18 and adult, GC-B expression in brain is highest and widely distributed around postnatal d 1. The striking perinatal GC-B peak coincides with elevated expression of nestin, a marker protein for neural stem/progenitor cells. Immunohistochemical investigations revealed a cell body-restricted subcellular localization of GC-B and perinatal abundance of GC-B-expressing cells in regions high in nestin-expressing cells. However, and supported by examination of nestin-GFP transgenic mice, GC-B and nestin are not coexpressed in the same cells. Rather, GC-B(+) cells are distinguished by expression of NeuN, an early marker of differentiating neurons. These findings suggest that GC-B(+) cells represent neuronal fate-specific progeny of nestin(+) progenitors and raise the attention to specific and pronounced activities of CNP/GC-B signaling during perinatal brain maturation. The absence of this activity may cause the neurological disorders observed in GC-B-deficient mice

    Functional properties of Lactobacillus plantarum strains: A multivariate screening study

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    Abstract Thirty-two Lactobacillus plantarum strains isolated from different sources were genetically characterized at subspecies level with recA gene based multiplex PCR and pulsed-field electrophoresis. All the strains were tested in vitro for functional properties (ability to form biofilms, agglutination of yeast cells, bile salt hydrolase activity, β-galactosidase activity, surface hydrophobicity, resistance to lysozyme, gastric juice and bile salts), for antimicrobial activity and for antibiotic resistance. The presence of bsh and msa genes and of the pln bacteriocin loci were also evaluated. Hierarchical cluster analysis was used to identify eight different plantaritypes sharing similar patterns of pln loci. A global functional score was calculated by transforming values for continuous in vitro functional properties in an ordinal scale by cluster analysis, while a nominal scale was used for the other properties. Multidimensional scaling was used to evaluate the similarity in functional properties among the isolates and to evaluate the relationships between source of isolation and functional properties. Nine strains showed the best in vitro functional potential and a significant relationship was found between source of isolation and functional score. This study confirmed a high heterogeneity in functional properties among L. plantarum strains and provides insight for optimal screening strategies

    Polymorphisms in stress response genes in Lactobacillus plantarum: implications for classification and heat stress response

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    The polymorphism of 5 stress response genes (hrcA, ctsR, clpP, ftsH, dnaK) in 32 Lactobacillus plantarum strains was evaluated by multilocus restriction typing (MLRT) and by sequence analysis of ctsR, hrcA and clpP genes. Both these approaches allowed the discrimination of the subspecies L. plantarum ssp. plantarum and L. plantarum ssp. argentoratensis. HrcA sequence analysis also allowed discrimination at the species and subspecies level of several species of lactic acid bacteria, thus confirming that it can be used as a valuable taxonomic marker. No significant relationship was found between stress response gene polymorphism and resistance to heat treatments. The effect of temperature on growth kinetics and the protein expression were investigated for selected strains carrying different mutations in hrcA. L. plantarum ssp. argentoratensis NCIMB12120 and L. plantarum ssp. plantarum DPC2159, both of which had mutations in domains of HrcA which are important for the repressor functionality, had a reduced growth rate at all temperatures tested (25, 30, 37, 40, and 42 °C) compared to L. plantarum WCFS1. In L. plantarum DPC2159, protein expression upon temperature shifts from 25 to 40 °C or growth at 40 °C was altered compared to L. plantarum WCFS1, but further study is needed to unequivocally confirm the relationship with mutations in hrcA

    Influence of Maternal Obesity on Insulin Sensitivity and Secretion in Offspring

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    OBJECTIVE—The purpose of this study was to clarify the effects of maternal obesity on insulin sensitivity and secretion in offspring

    Reversal of type 2 diabetes: normalisation of beta cell function in association with decreased pancreas and liver triacylglycerol

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    The presence of Fc-receptor-blocking factors in the sera of normal and insulin-dependent diabetic pregnant women was investigated by means of an antibody-dependent cell-mediated cytotoxicity assay. Sera from normal pregnant women induced a significant depression of antibody dependent cell-mediated cytotoxicity when compared with sera from normal and diabetic non-pregnant women (p less than 0.0001; p less than 0.002, respectively). The effect of sera from diabetic pregnant women, however, was not different from that observed with sera from normal and diabetic non-pregnant women. Thus, we confirm the presence of Fc-receptor-blocking factors in the sera of normal pregnant women. The higher cytotoxicity levels measured in the presence of sera from pregnant women with insulin-dependent diabetes suggests that the titres of such factors are reduced in this conditio

    Improvement in Peripheral Glucose Uptake After Gastric Bypass Surgery Is Observed Only After Substantial Weight Loss Has Occurred and Correlates with the Magnitude of Weight Lost

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    # 2009 The Author(s). This article is published with open access at Springerlink.com Introduction Altered gut and pancreatic hormone secretion may bolster resolution of insulin resistance after Roux-en-Y gastric bypass (RYGB), but the independent effects of weight loss and hormonal secretion on peripheral glucose disposal are unknown. Methods Two groups of nondiabetic morbidly obese patients were studied: RYGB followed by standardized caloric restriction (RYGB, n=12) or caloric restriction alone (diet, n=10). Metabolic evaluations (euglycemic–hyperinsulinemic clamp, meal tolerance test) were done at baseline and 14 days (both groups) and 6 months after RYGB
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