背景与目的：有研究表明，尿中修饰核苷的含量在多数恶性肿瘤患者中有明显升高。本研究拟探讨检测尿中核苷在胃癌诊断中的意义。方法：应用高效液相色谱法分别检测50名正常人与48例胃癌患者尿中15种核苷的水平，48例胃癌患者中有25例同时接受了血清CEA检测。结果：50名正常人和48例胃癌患者尿中15种核苷的平均值分别依次为：Pseu 22.91±4.90，34.87±21.41；00.34±0.32，0.62±0.82；AO.58±0.16，0.96+0.75；C0.17±0.15，0.24±0.19：m 500.03±0.07，0.07±0.06：10.26±0.10，0.43±0.36；mlll.34±0.34，2.44±1.39；ac4CO.75±0.24，1.08±0.72；GO.09±0.04，0.14±0.10；X1.20±0.42，1.90±1.09：m2G0。61±0.16，1.00±0。69；m6A0。04±1.13，0.07±0.08：mIA2.26±0.56，3.71±2.21：m22C1.34±0.27，2.25±1.39；mIG0。80±0。25，1。41±0.86。癌患者尿中除m5U外，其余14种核苷的平均值明显高于正常人（P<0.05）；次黄嘌呤与肿瘤大小，淋巴结转移正相关（P<0.05）；黄嘌呤核苷与肿瘤淋巴结转移正相关（JD<0.05）。以其中15种核苷浓度作为数据矢量，结合主成分分析。投影判别法区分正常人和胃癌患者，63%的胃癌患者被识别。识别率大大高于CEA检测（12%）。结论：胃癌患者尿中修饰核苷水平升高，检测尿中修饰核苷对胃癌的初筛有。定的参考意义。

Colorectal cancer(CRC)is one of the most common malignancies worldwide.The incidence of CRC in the Chinese population has increased dramatically during the last two decades; however,nonrandom chromosomal alterations in Chinese patients have not been described.In the present study, comparative genomic hybridization(CGH)was applied to detect recurrent chromosome alterations in 26 primary colorectal carcinomas and 21 colorectal adenomas from Chinese patients.In CRC,several recurrent chromosomal changes were found,including gains of 8q (14/26 cases, 54%), 20q (54%), 3q (50%), 13q( 50%), 5p (46%), 7p (42%), 7q (42%), and 12p (38%) and losses of 18q (65%) and 17p (42%). From comparison with previous CGH studies,the frequent gains of 3q and 12p might be distinctive occurrences in Chinese patients.The distribution of frequently found chromosomal alterations in different locations was studied.The gain of 20q was more frequently found in colon cancer (P<0.01) and the gain of 12p was more frequently found in rectal cancer.Chromosomal alterations were found in 19/21 of adenomas; the most frequent chromosomal alteration was the loss of 18q (9/21 cases, 43%). These recurrent alterations provide several starting points for the isolation of candidate oncogenes and tumor suppressor genes.

Accurate and fast genotyping of single nucleotide polymorphisms(SNPs)is important in the human genome project. Here an automated fluorescent method that can rapidly and accurately genotype multiplex known SNPs was developed by using a homemade kit, which has lower cost but higher resolution than commercial kit. With this method, oncogene K-ras was investigated, four known SNPs of K-ras gene exon 1 in 31 coloerctal cancer patients were detected. Results indicate that mutations were present in 8(26%)of 31 patients, and most mutations were localized in codon 12. The presence of these mutations is thought to be a critical step and plays an important role in human colorectal carcinogenesisas

利用自制试剂盒，在ABI310型遗传分析仪上建立了单链构象多态性分析、单链构象多态性/杂合分析及SNaPshot分析的基因突变检测方法，并将其应用于31例大肠癌病人P53基因外显子7-8和k-ras基因外显子1的突变筛查，结果表明，在各自的优化条件下，用自制试剂盒比用商品化的试剂盒分析时间更短，分离性能更好。对实际样品的检测结果表明，P53基因外显子7-8和k-ras基因外显子1在被检测人群中的突变频率分别为24%和26%，均为单点突变，其中大部分样品的突变发生在单个基因，只有一例样品同时在两个基因发生突变，这说明肿瘤的发生发展有多种途径，而且与多个基因的突变相关，