Serotonin (5-HT) has been found to stimulate meiotic maturation of oocytes in many molluscs. During maturation, several signaling pathways are involved, especially the phosphatidylinositol and cAMP pathways. In order ...Serotonin (5-HT) has been found to stimulate meiotic maturation of oocytes in many molluscs. During maturation, several signaling pathways are involved, especially the phosphatidylinositol and cAMP pathways. In order to examine the possible role of the phosphatidylinositol signaling pathway in regulating oocyte maturation in Mercenaria mercenaria, the effects of the activator/inhibitor of phospholipase (PLC) and protein kinase C (PKC) on serotonin-induced maturation were studied. Results show that high-concentrations of neomycin (inhibitor of PLC) blocked oocyte maturation, while 9, 10-dimethyl-1, 2-benzanthracene (DMBA, activator of PLC) promoted oocyte maturation in the presence of serotonin. It was also found that in the presence of serotonin, phorbol 12-myristate 13-acetate (PMA, activator of PKC) inhibited oocyte maturation, while sphingosine (inhibitor of PKC) stimulated oocyte maturation. These results indicate that serotonin-induced oocyte maturation requires the activation of the phosphatidylinositol pathway. Decrease of PLC inhibited serotonin-induced oocyte maturation, whereas a decrease of PKC stimulated the maturation. Thus, our study indicates that serotonin promotes maturation of M. mercenaria oocytes through PLC stimulated increase in calcium ion concentration via inositol-1, 4, 5-trisphosphate (IP3) but not PKC.展开更多
To investigate the epidemiological status of extended spectrum β lactamase (ESBL) producing Escherichia coli (E. coli) and Klebsiella pneumoniae (K. pneumoniae) and the drug resistance profiles of such organisms ...To investigate the epidemiological status of extended spectrum β lactamase (ESBL) producing Escherichia coli (E. coli) and Klebsiella pneumoniae (K. pneumoniae) and the drug resistance profiles of such organisms Methods A total of 282 clinical isolates of E coli and 180 of K pneumoniae were collected from different districts of Zhejiang Province Inhibitor potentiated broth dilution tests were performed for detecting extended spectrum β lactamases Etests were performed to detect the drug resistance of these strains against nine commonly used antibiotics Results The prevalence of extended spectrum β lactamases in E coli and K pneumoniae was 34 0% and 38 3%, respectively The average prevalence of extended spectrum β lactamases in E coli and K pneumoniae was 35 7% The resistance prevalence of extended spectrum β lactamase producing strains to ceftazidime and cefotaxime was 40% and 26% respectively, so were those to cefepime, cefoxitin, piperacillin tazobactam, cefoperazone sulbactam, amikacin and ciprofloxacin All these strains were sensitive to imipenem Conclusion The results in this study showed that the prevalence of extended spectrum β lactamases was high, while extended spectrum β lactamase producing strains were resistant to most antimicrobial agents except imipenem展开更多
基金Supported by the National High Tecnhology Research and Development Program of China (863 Program) (No. 2004AA603810)
文摘Serotonin (5-HT) has been found to stimulate meiotic maturation of oocytes in many molluscs. During maturation, several signaling pathways are involved, especially the phosphatidylinositol and cAMP pathways. In order to examine the possible role of the phosphatidylinositol signaling pathway in regulating oocyte maturation in Mercenaria mercenaria, the effects of the activator/inhibitor of phospholipase (PLC) and protein kinase C (PKC) on serotonin-induced maturation were studied. Results show that high-concentrations of neomycin (inhibitor of PLC) blocked oocyte maturation, while 9, 10-dimethyl-1, 2-benzanthracene (DMBA, activator of PLC) promoted oocyte maturation in the presence of serotonin. It was also found that in the presence of serotonin, phorbol 12-myristate 13-acetate (PMA, activator of PKC) inhibited oocyte maturation, while sphingosine (inhibitor of PKC) stimulated oocyte maturation. These results indicate that serotonin-induced oocyte maturation requires the activation of the phosphatidylinositol pathway. Decrease of PLC inhibited serotonin-induced oocyte maturation, whereas a decrease of PKC stimulated the maturation. Thus, our study indicates that serotonin promotes maturation of M. mercenaria oocytes through PLC stimulated increase in calcium ion concentration via inositol-1, 4, 5-trisphosphate (IP3) but not PKC.
文摘To investigate the epidemiological status of extended spectrum β lactamase (ESBL) producing Escherichia coli (E. coli) and Klebsiella pneumoniae (K. pneumoniae) and the drug resistance profiles of such organisms Methods A total of 282 clinical isolates of E coli and 180 of K pneumoniae were collected from different districts of Zhejiang Province Inhibitor potentiated broth dilution tests were performed for detecting extended spectrum β lactamases Etests were performed to detect the drug resistance of these strains against nine commonly used antibiotics Results The prevalence of extended spectrum β lactamases in E coli and K pneumoniae was 34 0% and 38 3%, respectively The average prevalence of extended spectrum β lactamases in E coli and K pneumoniae was 35 7% The resistance prevalence of extended spectrum β lactamase producing strains to ceftazidime and cefotaxime was 40% and 26% respectively, so were those to cefepime, cefoxitin, piperacillin tazobactam, cefoperazone sulbactam, amikacin and ciprofloxacin All these strains were sensitive to imipenem Conclusion The results in this study showed that the prevalence of extended spectrum β lactamases was high, while extended spectrum β lactamase producing strains were resistant to most antimicrobial agents except imipenem
