ABSTRACT
BACKGROUND: Human granulocyte-macrophage colony stimulating factor (hGM-CSF) is a kind of cytokine which can stimulate the differentiation and proliferation of haematopoictic precursor cells and plays an important role in the process of immunoloregulation. Escherichia coli (E.coli) expression system has advantages,such as low cost and high output, over other systems.Therefore, E.coli is still the most commonly used exogenous gene expression system.OBJECTIVE: To observe the expression of hGM-CSF in the E.coli swain DH5α.DESIGN, TIME AND SETTING: The present observational experiment was performed at the Central Laboratory of Biotechnology Research,China Three Gorges University between February and June 2007. MATERIALS: Plasmid pBR322hGM-CSF was purchased from American Type Culture Collection, USA.hGM-CSF antibody was sourced from Sigma Company, USA.IPTG, X-gal,and vector pMGT-18 were purchased from Shanghai Bioengineering Technology Company, China. METHODS: Primer was designed according to hGM-CSF gene. Taking cloning vector plasmid pBR322-hGM-CSF as template, hGM-CSF gene was acquired and recombined into prokaryotic expression vector pGEX-4T-1. Recombinant plasmid confirmed by enzyme digestion and sequencing was transformed into E.coli strain DH5α and induced by isopropy-β-D-thiogalactoside (IPTG). Expression product was identified by sodium dodecyl sulfate polyacrylamide gel electropheresis (SDS-PAGE) and detected by Western blotting assay. MAIN OUTCOME MEASURES: hGM-CSF expression in the E.coli strain DH5α. RESULTS: SDS-PAGE results revealed that the recombinant hGM-CSF protein with relative molecular weight of 40 500 was produced up to approximately 17.9% of total protein. Western blotting detection results indicated that there was a 40 500 bp brand. CONCLUSION: The present study reconstructed prokaryotic expression vector pGEX-hGM-CSF, induced its expression in the E.coli strain DH5α, and obtained hGM-CSF fusion protein.
ABSTRACT
The paper concluded systematically the progress of study on KCNQ1 in recent years.Firstly,the structure of ? subunit or ? subunit and its interaction between each other were explained in the paper.Secondly,the physiological function of complex KCNQ1/KCNE was interviewed,such as many kinds of inherited cardiac arrhythmias induced by mutation of KCNQ1 or KCNE and secretion of KCNQ1 in different epithelial cells.Eventually,the paper introduced the study of antagonists and agonists on KCNQ1 channel.
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AIM To study the protective and antiperoxidative effects of baicalin on myocardial ischemia. METHODS The rat anterior decenging branch of left coronary artery was occluded for 40 min and reperfusion for 120 min. Hemodynamics (LVP, LV d p /d t ) and electrocardiogram (ECG, lead Ⅱ) monitored continuously with polygraph,then the myocardium were taken to assay lactate dehydrogenase(LDH), malondialdehyde (MDA) contents and superoxide dismatase (SOD). RESULTS Baicalin 10 or 40 mg?kg -1 iv depressed changes in LDH, MDA and SOD in myocardium after ischemia for 40 min and reperfusion for 120 min in rats. Baicalin 10 and 40 mg?kg -1 iv markedly improved the ?d p /d t max (kPa?s -1 ), LVSP in rat after ischemia for 40 min and reperfusion. CONCLUSION Baicalin possesses a protective effect against myocardial ischemia via attenuating lipid peroxidation.
ABSTRACT
The action of Tetrahydroberberine ( THB ) on arrhythmias of the animal models were studied. The arrhythmias induced by CaCl2 and BaCl2 were significantly counteracted by THB ( 30mg/kg ip ) without markedly changing the hemodynamic parameters of rats, but those evoked by aconitine or ouabain were not inhibited in rats or guinea pigs. THB ( 40mg/kg ip) was used to be prevented the arrhythmias induced by ischaemia-reperfusion of left anterior des-cending coronary artery in rats. It could decrease the incidence of vetricular fibrillation, short restored time of the sinus rhythm and diminish the mortality. THB ( 10mg/kg iv ) effectively reduced the incidence of the ventricular arrhythmia induced by hypothalamic electric stimulation in rabbits. The results indicate that THB possess significant antiarrhythmic effect. It may be concerned the action of THB to blok calcium entry