| 1 | Somatic mutation analysis of p53 and ST7 tumor suppressor genes in gastric carcinoma by DHPLC显示文摘AIM: To verify the effectiveness of denaturing highperformance liquid chromatography (DHPLC) in detecting somatic mutation of p53 gene in gastric carcinoma tissues.The superiority of this method has been proved in the detection of germline mutations, but it was not very affirmative with respect to somatic mutations in tumor specimens. ST7 gene, a candidate tumor suppressor gene identified recently at human chromosome 7q31.1, was also detected because LOH at this site has also been widely reported in stomach cancer.METHODS: DNA was extracted from 39 cases of surgical gastric carcinoma specimen and their correspondent normal mucosa. Seven fragments spanning the 11 exons were used to detect the mutation of p53 gene and the four exons reported to have mutations in ST7 gene were amplified by PCR and directly analyzed by DHPLC without mixing with wild-type allele.RESULTS: In the analysis of p53 gene mutation, 9 aberrant DHPLC chromatographies were found in tumor tissues, while their normal-adjacent counterparts running in parallel showed a normal shape. Subsequent sequencing revealed nine sequence variations, 1 polymorphism and 8 mutations including 3 mutations not reported before. The mutation rate of p53 gene (21%) was consistent with that previously reported. Furthermore, no additional aberrant chromatography was found when wild-type DNA was added into the DNA of other 30 tumor samples that showed normal shapes previously. The positivity of p53 mutations was significantly higher in intestinal-type carcinomas (40 %) than that in diffuse-type (8.33 %) carcinomas of the stomach. No mutation of ST7 gene was found.CONCLUSION: DHPLC is a very convenient method for the detection of somatic mutations in gastric carcinoma. The amount of wild type alleles supplied by the non-tumorous cells in gastric tumor specimens is enough to form heteroduplex with mutant alleles for DHPLC detection. ST7 gene may not be the target gene of inactivation at 7q31 site in gastric carcinoma. | ChongLu Hui-MianXu QunRen YangAo Zhen-NingWang XueAo LiJiang YangLuo XueZhang | 2003 | World Journal of Gastroenterology2003，9，12： | 4 |
| 2 | 基于运行网络配流的客专列车开行方案遗传优化研究显示文摘借助于遗传算法的求解功能和特点,将客运专线旅客列车开行方案优化问题描述为对列车运行网络客流分配的寻优。最优的列车开行方案对应于最优的客流分配方案。首先,针对任意的列车开行方案,构建费用—容量运行网络,并通过该网络的最小费用流描述最优客流分配方案,用运行网络中客流分配的最小费用作为个体适应值函数;而后,考虑到网络中列车保本定员限制所产生大量不可行个体的优良遗传信息,设计出求解直线型客运专线单方向旅客列车开行方案优化问题的协同对称群体交叉遗传算法,并进一步将其推广到网状客运专线上。研究发现:可以将开行方案编码的个体描述为含有阶跃容量限制的费用—容量网络,个体的适应值对应于该网络的最小费用流;在非能力过剩网络中,不会出现违反阶跃容量限制的可行流,并且可以通过控制网络容量,避免产生固定费用和负费用。 | Dong, Shouqing Yan, Haifeng Li, Qunren | 2012 | 中国铁道科学2012，，4： | 3 |
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