38 research outputs found

    A mRNA landscape of bovine embryos after standard and MAPK-inhibited culture conditions: a comparative analysis.

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    BACKGROUND: Genes and signalling pathways involved in pluripotency have been studied extensively in mouse and human pre-implantation embryos and embryonic stem (ES) cells. The unsuccessful attempts to generate ES cell lines from other species including cattle suggests that other genes and pathways are involved in maintaining pluripotency in these species. To investigate which genes are involved in bovine pluripotency, expression profiles were generated from morula, blastocyst, trophectoderm and inner cell mass (ICM) samples using microarray analysis. As MAPK inhibition can increase the NANOG/GATA6 ratio in the inner cell mass, additionally blastocysts were cultured in the presence of a MAPK inhibitor and changes in gene expression in the inner cell mass were analysed. RESULTS: Between morula and blastocyst 3,774 genes were differentially expressed and the largest differences were found in blastocyst up-regulated genes. Gene ontology (GO) analysis shows lipid metabolic process as the term most enriched with genes expressed at higher levels in blastocysts. Genes with higher expression levels in morulae were enriched in the RNA processing GO term. Of the 497 differentially expressed genes comparing ICM and TE, the expression of NANOG, SOX2 and POU5F1 was increased in the ICM confirming their evolutionary preserved role in pluripotency. Several genes implicated to be involved in differentiation or fate determination were also expressed at higher levels in the ICM. Genes expressed at higher levels in the ICM were enriched in the RNA splicing and regulation of gene expression GO term. Although NANOG expression was elevated upon MAPK inhibition, SOX2 and POU5F1 expression showed little increase. Expression of other genes in the MAPK pathway including DUSP4 and SPRY4, or influenced by MAPK inhibition such as IFNT, was down-regulated. CONCLUSION: The data obtained from the microarray studies provide further insight in gene expression during bovine embryonic development. They show an expression profile in pluripotent cells that indicates a pluripotent, epiblast-like state. The inability to culture ICM cells as stem cells in the presence of an inhibitor of MAPK activity together with the reported data indicates that MAPK inhibition alone is not sufficient to maintain a pluripotent character in bovine cells

    Antibacterial Efficacy of Dihydroxylated Chalcones in Binary and Ternary Combinations with Nalidixic Acid and Nalidix Acid–Rutin Against Escherichia coli ATCC 25 922

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    In order to determine the existence of synergism, the bacteriostatic action of flavonoids against Escherichia coli ATCC 25 922 between dihydroxylated chalcones and a clinically interesting conventional antibiotic, binary combinations of 2′,3-dihydroxychalcone, 2′,4-dihydroxychalcone and 2′,4′-dihydroxychalcone with nalidixic acid and its ternary combinations with rutin (inactive flavonoid) were assayed against this Gram negative bacterium. Using a kinetic-turbidimetric method, growth kinetics were monitored in broths containing variable amounts of dihydroxychalcone alone, combinations of dihydroxychalcone variable concentration–nalidixic acid constant concentration and dihydroxychalcone variable concentration–nalidixic acid constant concentration–rutin constant concentration, respectively. The minimum inhibitory concentrations of dihydroxychalcones alone and its binary and ternary combinations were evaluated. All chalcones, and their binary and ternary combinations showed antibacterial activity, being rutin an excellent synergizing for the dihydroxychalcone–nalidixic acid binary combination against E. coli ATCC 25 922. Thus, this synergistic effect is an important way that could lead to the development of new combination antibiotics against infections caused by E. coli

    Vagal determinants of exercise capacity

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    British Heart Foundation (A.V.G., G.L.A.; Ref: RG/14/4/30736), The Wellcome Trust (A.V.G.; Refs 095064 and 200893), Medical Research Council (S.K.; Ref: MR/L020661/1), Academy of Medical Sciences/Health Foundation Clinician Scientist Fellowship (G.L.A.), and Royal College of Anaesthetists/British Journal of Anaesthesia Basic Science Career Development Award (G.L.A.). MB PhD funding for A.M. was provided by the Medical Research Council and The Rosetrees Trust. A.V.G. is a Wellcome Trust Senior Research Fellow

    Real-time monitor on the release of salicylic acid from chitosan gel beads by means of dielectric spectroscopy

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    The release processes of salicylic acid (SA) from the chitosan gel beads (CGB) with different crosslinking densities were monitored in real time by means of dielectric spectroscopy. Distinct dielectric relaxations attributed to interfacial polarization were observed, which exhibited obvious dependences on the crosslinking density and the release time. In line with Hanai's equation, the properties of CGB and release media were quantitatively determined from the dielectric profiles. Based on these properties and dielectric behaviors, the release profiles were analyzed. It was found that only the dispersion of CGB with the lowest crosslinking density exhibited release behavior, while other dispersions showed an obvious adsorption process following a burst of drug diffusion. The total loading and release amount of SA were determined and compared, and the influence of crosslinking degree on the drug loading and release was discussed. In addition, the release behavior was confirmed to be diffusionally controlled, and the diffusion coefficient of SA was determined

    IFN-γ is essential for the inhibition of B16BL6 melanoma lung metastasis in chronic alcohol drinking mice

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    We previously found that chronic alcohol consumption (20% w/v in drinking water) that models the level consumed by human alcoholics, when administered to female C57BL/6 mice inhibits B16BL6 melanoma metastasis to the lung; however, the mechanism is not known. Chronic alcohol consumption increases IFN-γ producing NK, NKT, CD4+, and CD8+ T cells. To examine the impact of IFN-γ on metastasis, we inoculated B16BL6 melanoma cells i.v. into control and chronic alcohol drinking IFN-γ knockout (KO) mice. Knockout of the ifn-γ gene abrogated the anti-metastatic effects associated with alcohol consumption. We examined metastasis in common gamma-chain (γC) KO mice, which are deficient in NK, NKT and CD8+ T cells, and in Vα14Jα281−/− KO mice, which are deficient in invariant NKT (iNKT) cells, in order to assess the importance of specific IFN-γ producing cell types to this effect. We found that the antimetastatic effect of alcohol was still present in γC KO mice and also in γC KO mice depleted of Gr-1+ cells. Knockout of iNKT cells reduced the degree but not the antimetastatic effect associated with alcohol. These results indicate that the antimetastatic effect induced by chronic alcohol consumption is IFN-γ dependent and that multiple IFN-γ producing cell types contribute to this effect
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