Objective: The integrated method was investigated to measure Vm/Km of mouse liver glutathione S-transferase (GST) activity on GSH and 7-Cl-4-nitrobenzofurazozan. Methods: Presetting concentration of one substrate twen...Objective: The integrated method was investigated to measure Vm/Km of mouse liver glutathione S-transferase (GST) activity on GSH and 7-Cl-4-nitrobenzofurazozan. Methods: Presetting concentration of one substrate twenty-fold above the others and taking maximum product absorbance Am as parameter while Km as constant, Vm/Km was obtained by nonlinear fitting of GST reaction curve to the integrated Michaelis-Menten equation ln [Am/(Am-Ai)]+Ai/(ε×Km)=(Vm/Km)×ti (1). Results: Vm/Km for GST showed slight dependence on initial substrate concentration and data range, but it was resistant to background absorbance, error in reaction origin and small deviation in presetting Km. Vm/Km was proportional to the amount of GST with upper limit higher than that by initial rate. There was close correlation between Vm/Km and initial rate of the same GST. Consistent results were obtained by this integrated method and classical initial rate method for the measurement of mouse liver GST. Conclusion: With the concentration of one substrate twenty-fold above the others, this integrated method was reliable to measure the activity of enzyme on two substrates, and substrate concentration of the lower one close to its apparent Km was able to be used.展开更多
目的：探讨重组人血管内皮抑素（recombinant human endostatin,rh-ES）联合化放疗治疗晚期恶性肿瘤的疗效及安全性。方法：回顾性分析我科2010年1月至2013年8月收治的27例晚期恶性肿瘤患者病例,27例患者均接受rh-ES联合化疗±放疗...目的：探讨重组人血管内皮抑素（recombinant human endostatin,rh-ES）联合化放疗治疗晚期恶性肿瘤的疗效及安全性。方法：回顾性分析我科2010年1月至2013年8月收治的27例晚期恶性肿瘤患者病例,27例患者均接受rh-ES联合化疗±放疗的综合治疗,rh-ES用药1周期后评价生活质量变化及不良反应,2周期后评价疗效。结果：23例可评价近期疗效的患者客观有效率30.4%,疾病控制率78.3%。18例非小细胞肺癌（non-small cell lung cancer,NSCLC）中位无进展生存期5.5月,中位总生存期12.0月,1年生存率50.0%,2年生存率28.6%。全组患者生活质量改善或稳定23例（85.2%）,Ⅲ~Ⅳ度不良反应8例次。结论：Rh-ES联合化放疗治疗晚期恶性肿瘤的疗效及安全性良好,可改善或稳定患者生活质量。与其他单纯化疗研究结果比较,晚期NSCLC的中位无进展生存期及1年生存率较高,值得临床推广。展开更多
文摘目的:探讨Dkkl cDNA抗结肠癌的机制.方法:利用脂质体介导pcDNA3.1(+)Dkk1进行瞬时转染结肠癌细胞CT26和表达Dkk1的肝癌细胞HEPA1-6,转染后的细胞为实验组,转染空载体pcDNA3.1(+)的细胞和未转染的细胞分别为空载体组和未转染组,用MTT法检测CT26增殖、免疫印迹法检测细胞Dkk1,p53,Bcl-2和Bax的表达量.结果:MTT实验显示在570 nm的吸光度均值CT26实验组明显低于其空载体组和未转染组(0.779±0.025 vs 0.968±0.016,0.973±0.016),P<0.05);与CT26空载体组和未转染组相比,实验组p53,Bcl-2的表达量降低、而Dkk1、Bax表达增高.结论:外源Dkk1可反馈抑制突变型p53的生成,下调Bcl-2,增加Bax因子表达而抑制结肠癌的增殖.
基金National Natural Science Foundation of China (No.30200266)
文摘Objective: The integrated method was investigated to measure Vm/Km of mouse liver glutathione S-transferase (GST) activity on GSH and 7-Cl-4-nitrobenzofurazozan. Methods: Presetting concentration of one substrate twenty-fold above the others and taking maximum product absorbance Am as parameter while Km as constant, Vm/Km was obtained by nonlinear fitting of GST reaction curve to the integrated Michaelis-Menten equation ln [Am/(Am-Ai)]+Ai/(ε×Km)=(Vm/Km)×ti (1). Results: Vm/Km for GST showed slight dependence on initial substrate concentration and data range, but it was resistant to background absorbance, error in reaction origin and small deviation in presetting Km. Vm/Km was proportional to the amount of GST with upper limit higher than that by initial rate. There was close correlation between Vm/Km and initial rate of the same GST. Consistent results were obtained by this integrated method and classical initial rate method for the measurement of mouse liver GST. Conclusion: With the concentration of one substrate twenty-fold above the others, this integrated method was reliable to measure the activity of enzyme on two substrates, and substrate concentration of the lower one close to its apparent Km was able to be used.
