九源奖学金

Porcine Kidney 18kD peptidyl-prolyl cis-trans isomerase (PPIase) belongs to the cyclophilin family that is inhibited by the immunosuppressive drug cyclosporin A. The chaperone activity was studied using inactive, active, and alkylated PPIase during rabbit muscle creatine kinase (CK) refolding. The results showed that low concentration inactive or active PPIase was able to improve the refolding yields, while high concentration PPIase decreased the CK reactivation yields. Aggregation was inhibited by inactive or active PPIase, and completely suppressed at 32 or 80 times the CK concentration (2.7μM). However, alkylated PPIase was not able to prevent CK aggregation. In addition, the ability of inactive PPIase to affect CK reactivation and prevent CK aggregation was weaker than that of active PPIase. These results indicate that PPIase interacted with the early folding intermediates of CK, thus preventing their aggregation in a concentration-dependent manner. PPIase exhibited chaperone-like activity during CK refolding. The results also suggest that the isomerase activity of independent of the chaperone activity, and that the proper molar ratio was important for the chaperone activity of PPIase. The cysteine residues of PPIase may be a peptide binding site, and may be an essential group for the chaperone function.

作者：欧文斌（清华大学生物科学与技术系，生物化学与分子生物学博士，导师：周海梦教授）

2、Detecting bladder cancer in the Chinese by microsatellite analysis：Ethnic and Etiological Considerations （发表刊物：J Natl Cancer Inst 2001；93：45-50）

Background: Microsatellite analysis of urine sediments has shown promise as a highly sensitive and specific technique for the detection of bladder cancer. However, most studies have been conducted in Western countries with Caucasian subjects. We explored the potential of microsatellite analysis for detecting bladder cancer in Chinese people. Methods: We performed microsatllite analysis of surgical specimens and urine sediment cells collected from Chinese patients with bladder tumors. Those microsatellite markers giving clearly readable patterns and showing susceptibility to alterations were used as a panel to detect primary tumors. A blinded study of additional patients with bladder cancer was performed to investigate the practical value of this panel for detecting bladder cancer. All statistical tests were two-sided. Results: Thirty-eight bladder tumors and corresponding urine sediment specimens were initially screened for 60 microsatellite markers from 18 chromosomes. Nine markers, most of which were different from those that had been used for Western patients, with frequent alterations in the initial patients were selected for further analysis, In the subsequent blinded experiment, microsatellite alterations were observed in urine sediments from 22 (96%) of 23 patients with bladder cancer and from all three patients with inverted papilloma. None of the urine sediments from the one patient with bladder lipoma, from the one patient with neurofibroma, or from the 12 individuals without evidence of bladder tumor showed any microsatellite alterations. Conclusions :Microsatellite analysis of urine sediments could be a practical method for detecting bladder cancer in the Chinese. Our identification of different microsatellite markers highlights possible ethnic and etiologic disparities between the Chinese and Western bladder cancer patients.

作者：张建军（中国协和医科大学肿瘤所，中国医学科学院肿瘤医院肿瘤学博士，导师：程书钧院士）

3、African Origin of Modern Humans in East Asia：A Tale of 12,000 Y Chromosomes（发表刊物：SCIENCE（2001），Vol 292：1151-1153）

To test the hypotheses of modern human origin in East Asia, we sampled 12,127 male individuals from 163 populations and typed for three Y chromosome biallelic markers (YAP, M89, and M130). All the individuals carried a mutation at one of the three sites. These three mutations (YAP+, M89T, and M130T) coalesce to another mutation (M168T), which originated in Africa about 35,000to 89,000 years ago. Therefore, the date do not support even a minimal in situ hominid contribution in the origin of anatomically modern humans in East Asia.

作者：柯越海（复旦大学，遗传学博士，导师：金力教授）

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