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。

为研究四环素调控的胰岛素表达载体肌肉直接注射后对实验性糖尿病小鼠的降糖作用，构建了质粒prTA-tet42rhINS。以链脲佐菌素（STZ）诱导Balb/C小鼠成糖尿病模型，300μg质粒注射至小鼠的股部肌肉，并同时在饮水中加入不同浓度强力霉素（Dox），监测小鼠末梢血糖、体重，测定血清人胰岛素、C肽水平。用RT2PCR检测小鼠肌肉注射部位组织中人胰岛素原mRNA水平的表达情况。结果表明：质粒prTA2tet42rhINS注射后，给予Dox可显著降低糖尿病小鼠的血糖，血清人胰岛素、C肽水平相应升高，体重增加。效果持续大约二周。小鼠肌肉组织中有人胰岛素原mRNA表达。降糖效果和基因表达程度随Dox浓度增加而增强。质粒prTA2tet42rhINS对STZ诱导的糖尿病小鼠高血糖起到明显的降低作用。在糖尿病小鼠肌肉组织能很好地表达，并受Dox调控。

对单核苷酸多态性（SNP）的概念及特性作了简要说明，介绍了14种检测SNP的方法，讨论了各种方法的原理及优缺点，并对目前SNP在遗传图的绘制、遗传病致病基因的搜寻、药物设计及法医学等方面的应用及其研究进展进行了综述。引用文献29篇。

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

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.

对人类基因组中的单核苷酸多态性进行快速而准确的定位和分型是人类基因组计划的重要内容。本文利用SNaPshot试剂盒，建立了一种以多重引物延伸为基础、可同时对多个已知单核苷酸多态性位点进行快速而准确的遗传分型的方法。利用这一方法检测了20例大肠癌病人肿瘤组织中错配修复基因hMLH1和抑癌基因P53的8个单核苷酸多态性位点（包括5个突变热点），其中一例发现错配修复基因hMLH1的384位密码子处发生GTT→GAT的杂合性突变。对该基因外显子的直接测序结果与SNaPshot检测结果完全吻合，充分证明了该方法的可靠性。

Fluorescent-based single-strand conformation polymorphism(F-SSCP)analysis with capillary electrophoresis(CE)is the most common method for the detection of mutation because of its high sensitivity and resolution.In this study,we prepared an inexpensive linear polyacrylamide(LPA),and successfully applied it to CE-SSCP analysis and tandem CESSCP/heteroduplex analysis(HA)of the P53 gene on an ABI capillary genetic analyzer.A comparison of the sieving capabilities of a homemade LPA and commercial polydimethylacrylamide(PDMA)demonstrates that the homemade LPA has a higher resolution,a shorter analysis time,and is more suitable for tandem SSCP/HA than commercial PDMA.To show the usefulness,mutations of P53 gene exon 7-8 in 37 tumor samples were investigated by using homemade LPA.The results indicate that 10 mutations were found in 9 of 37 cases; the majority of P53 mutations were missense mutations,and 70% were located in exon 7,which plays an important role in neoplastic progression in human tumorigenesis.

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，

Objective:Thirteen urinary nucleosides,primarily degradation products of tRNA,were evaluated as potential tumor markers for breast cancer patients.Design and methods: The micellar electrokinetic chromatography(MEKC)method has been used to analyze the urinary nucleosides in 41 healthy controls,20 patients with benign breast tumors,and 26 breast cancer patients.Results: Urinary nucleoside concentrations of breast cancer patients were found to increase significantly compared to those of patients with benign breast tumors and healthy controls.By using 13 nucleoside concentrations as data vectors for principal component analysis (PCA), 73% (19/26) of breast cancer patients were correctly identified from healthy controls,while only 20% (4/20) of patients with benign breast tumors were indistinguishable from breast cancer patients. The mean level of all forms of urinary nucleosides in patients with metastatic breast cancer was higher than that in patients with primary breast cancer.The levels of modified nucleosides tended to decrease and return to normal after surgery.Conclusion: The results indicate that urinary nucleosides may be useful as tumor markers for breast cancer.