Telomerase, a ribonucleoprotein enzyme, has been found in immortalized but not in most somatic adult human tissues, and thus emerged as a novel target for cancer chemotherapy. Recently it has been found that telomeras...Telomerase, a ribonucleoprotein enzyme, has been found in immortalized but not in most somatic adult human tissues, and thus emerged as a novel target for cancer chemotherapy. Recently it has been found that telomerase is a fruitful target for oncologic drug development. A new method for screening antitumor agents by using telomerase as a target has been established according to the phenomena that the enzyme activity can be affected by some types of antitumor agents or chemicals. The telomerase was extracted from HeLa cells. The telomeric repeat amplification protocol(TRAP) was used to measure enzyme activity. Telomerase activity can be inhibited by 4 kinds of chemical compounds.展开更多
Telomerase is a ribonucleoprotein that catalyzes telomere elongation through the addition of TTAGGG repeats in humans. Activation of telomerase is often associated with immortalization of human cells and cancer. Parti...Telomerase is a ribonucleoprotein that catalyzes telomere elongation through the addition of TTAGGG repeats in humans. Activation of telomerase is often associated with immortalization of human cells and cancer. Partially purification of telomerase was obtained by chromatography of HeLa cell extract on DEAE-Sepharose FF,Spermine-Sepharose CL-6B and Sephacryl S-300. To dissect the human telomerase enzyme mechanism, the optimal catalytic conditions of telomerase were measured and the human telomerase activity was reconstituted using a purified hTR RNA. The optimum pH is from 6^5 to 8^5, the optimum temperature is from 35℃ to 40℃, the optimum Mg 2+ concentration is from 1 mmol/L to 2^5 mmol/L,the apparent binding constant (K m app) of telomerase for the primer is about 8^6 nmol/L. Partially purified human telomerase extract was treated with MNase to remove endogenous telomerase RNA(hTR),the telomerase activity was inactivation. Telomerase activity was restored by incubating MNase-treated extract with purified hTR. These results might facilitate the development of the telomerase enzyme mechanism.展开更多
目的探讨血清营养学指标与全髋关节置换隐性失血之间的相关性。方法根据患者术中失血量、术后出血量、手术前后红细胞压积和输血量,计算患者的总失血量、隐性失血量、原血量和总失血量的比例,按照平均隐性失血量占总失血量的比,分低隐...目的探讨血清营养学指标与全髋关节置换隐性失血之间的相关性。方法根据患者术中失血量、术后出血量、手术前后红细胞压积和输血量,计算患者的总失血量、隐性失血量、原血量和总失血量的比例,按照平均隐性失血量占总失血量的比,分低隐失血组和高隐失血组,分析高隐失血与术前血清营养学指标总蛋白(TP)、白蛋白(ALB)、前白蛋白(PA)、转铁蛋白(TRA)、淋巴细胞计数(TLC)、淋巴细胞百分比(TLP)、血红蛋白(HB)之间的关系。结果所有患者失血量平均为1298.47 m L,占原血量的30.13%;隐性失血总量平均517.03 m L,占总失血量的39.82%;101例患者发生高隐性失血,高隐性失血量组术前ALB、PA、TRA和TLP的平均数值明显低于低隐失血量组(P<0.05),高隐性失血量组术前ALB、PA、TRA、TLC、TLP和HB评估的隐性失血发生率明显高于低隐失血量组(P<0.05),高隐失血与ALB、PA、TRA、TLP和HB相关性强(相关系数分别为0.587、0.517、0.687、0.395和0.387,均P<0.05)。结论血清营养学指标(ALB、PA、TRA、TLP和HB)与关节置换术后高隐性失血紧密相关,判断高隐性失血的重要指标。展开更多
文摘Telomerase, a ribonucleoprotein enzyme, has been found in immortalized but not in most somatic adult human tissues, and thus emerged as a novel target for cancer chemotherapy. Recently it has been found that telomerase is a fruitful target for oncologic drug development. A new method for screening antitumor agents by using telomerase as a target has been established according to the phenomena that the enzyme activity can be affected by some types of antitumor agents or chemicals. The telomerase was extracted from HeLa cells. The telomeric repeat amplification protocol(TRAP) was used to measure enzyme activity. Telomerase activity can be inhibited by 4 kinds of chemical compounds.
基金国家自然科学基金 (No .30 0 70 85 9)资助项目国家重点基础研究规划资助项目 (No .G2 0 0 0 0 5 70 0 1)~~
文摘Telomerase is a ribonucleoprotein that catalyzes telomere elongation through the addition of TTAGGG repeats in humans. Activation of telomerase is often associated with immortalization of human cells and cancer. Partially purification of telomerase was obtained by chromatography of HeLa cell extract on DEAE-Sepharose FF,Spermine-Sepharose CL-6B and Sephacryl S-300. To dissect the human telomerase enzyme mechanism, the optimal catalytic conditions of telomerase were measured and the human telomerase activity was reconstituted using a purified hTR RNA. The optimum pH is from 6^5 to 8^5, the optimum temperature is from 35℃ to 40℃, the optimum Mg 2+ concentration is from 1 mmol/L to 2^5 mmol/L,the apparent binding constant (K m app) of telomerase for the primer is about 8^6 nmol/L. Partially purified human telomerase extract was treated with MNase to remove endogenous telomerase RNA(hTR),the telomerase activity was inactivation. Telomerase activity was restored by incubating MNase-treated extract with purified hTR. These results might facilitate the development of the telomerase enzyme mechanism.
文摘目的探讨血清营养学指标与全髋关节置换隐性失血之间的相关性。方法根据患者术中失血量、术后出血量、手术前后红细胞压积和输血量,计算患者的总失血量、隐性失血量、原血量和总失血量的比例,按照平均隐性失血量占总失血量的比,分低隐失血组和高隐失血组,分析高隐失血与术前血清营养学指标总蛋白(TP)、白蛋白(ALB)、前白蛋白(PA)、转铁蛋白(TRA)、淋巴细胞计数(TLC)、淋巴细胞百分比(TLP)、血红蛋白(HB)之间的关系。结果所有患者失血量平均为1298.47 m L,占原血量的30.13%;隐性失血总量平均517.03 m L,占总失血量的39.82%;101例患者发生高隐性失血,高隐性失血量组术前ALB、PA、TRA和TLP的平均数值明显低于低隐失血量组(P<0.05),高隐性失血量组术前ALB、PA、TRA、TLC、TLP和HB评估的隐性失血发生率明显高于低隐失血量组(P<0.05),高隐失血与ALB、PA、TRA、TLP和HB相关性强(相关系数分别为0.587、0.517、0.687、0.395和0.387,均P<0.05)。结论血清营养学指标(ALB、PA、TRA、TLP和HB)与关节置换术后高隐性失血紧密相关,判断高隐性失血的重要指标。
