The esophageal squamous cell carcinoma (ESCC) has high incidencein Shaanxi Province of China. More and more researches indicated that humanpapillomavirus type 16 (HPV16) might play an important role in carcinogenesis ofESCC but the relationship between HPV16 and CD44v6, nm23H1 has not beenelucidated. HPV16 was detected by amplifying HPV16 E6 gene through polymerasechain reaction (PCR) method and the expression of CD44v6,nm23H1in 40ESCCs and fifteen normal esophageal mucosa (NEM) from Shaanxi Province wasexamined by Streptavidin-Peroxidase (SP) method using monoclonal antibodyspecific to CD44v6 and nm23H1. The positive rates of HPV16 E6 gene, CD44v6and nm23H1 were 60% (24/40), 65% (26/40) and 45% (18/40) respectively inESCCs and 26.67% (4/15), 33.33% (5/15) and 86.67% (13/15) respectively inNEMs. There exited statistical difference for HPV16, CD44v6 and nm23H1between NEMs and ESCCs respectively (p<0.05). The relationship betweenHPV16 and the expression of CD44v6 in ESCCs was statistical significance(P=0.021), but no significant correlation was found between HPV16 and theexpression of nm23H1 (P=0.436) in ESCCs. The infection rate of HPV16 hadno statistical difference in all pathological features we observed, but the expressionrates of CD44v6 and nm23H1 had statistical correlation withinvasion (p=0.001, 0.013) and lymph nodes metastasis (p=0.014, 0.002) respectively.In different histology grade of ESSCs, the relationship between HPV16and CD44v6 was statistical significance in grade I (p=0.044) but was not ingrade II (p=0.165) and grade III (p=0.658), however as to the expressionof nm23H1 there exited no statistical significance in all histology grades of ESCC (p>0.05). The expression rates of CD44v6 and nm23H1 were statisticallydifferent between grade I and II (p=0.004, 0.016) respectively and betweengrade I and grade III (p=0.014, 0.020), but not statistically different betweengrade II and III (p=0.792, 0.943) respectively. Our data firstly suggested thatthere existed the statistical relationship between the infection of HPV16 and theexpression of CD44v6 in ESCCs and that HPV16 may be involved in invasion andmetastasis of ESCC.

Comparative genome analysis is performedbetween Shigella flexneri 2a strain 301 and its close relatives,the non-pathogenic E. coli K-12 strain MG1655. Resultshows that there are 136 DNA segments whose size is largerthan 1000 bp absent from Shigella flexneri 2a strain 301,which is up to 717253 bp in total length. These deleted segmentsaltogether contain 670 open reading frames (ORFs).Prediction of these ORFs indicates that there are 40% genesof unknown function. The other genes of definite functionsencode metabolic enzymes, structure proteins, transcriptionregulatory factors and some elements correlated with horizontaltransfer. Here we compare the complete genomicsequences of the two closely related species, which differ inpathogenic phenotype. To our knowledge, this not only revealsthe difference of genomic sequence between the twoimportant enteric pathogens for the first time, but alsoprovides valuable clues to further researches in its process ofphysiological activity, pathogenesis and the evolution of entericbacteria.

探讨了HPV16 E5基因突变与宫颈癌发病的关系。应用银染聚合酶链反应．单链构象多态性（PCR-SSCP）分析对50份人宫颈癌活检标本进行基因突变的筛查。PCR检测显示，50例官颈癌组织中艘V16 E5的检出率为 30%（15/50），其中6例宫颈癌唧V16 E5扩增片段在行SSCP分析时发现有泳动变位，突变率为40%（6/15）。可见HPVl6磷基因的突变在宫颈癌的发生过程中具有重要作用。

目的 建立人乳头瘤病毒16型E5基因的无性繁殖系为进一步研究其致癌机理作准备。方法 用PcR技术从HPVl6质粒DNA中扩增出E5基因序列连接到pGEM-T载体，将阳性的重组 DGEM-T用BamHI/ECORI双酶切并回收目的片段连接到原棱表 达载体DGEX 2T，转化DH5d菌株。取工程苗，IPTG诱导表达，SDS-PAGE电泳鉴定。结果 ①经PCR、测序和双酶切鉴定，认为HPVl6 E5正确插入上述表达载体，建立了该转化基因的无性繁殖 系。②经IPTG诱导的PGEX-2T-E5质粒表达出约42KD的融合蛋白，分析含有约16KDHPVl6E5蛋白，与预期含HPVl6 E5的融合蛋白分子量相符。结论 ①采用PCR克隆技术，扩增HPvl6 E5转化 基因目的片段，将其克隆到DGEM-T载体在国内首次建立了HPVl6E5转化基因的无性繁殖子。②成功构建HPVl6 E5基因的原 棱表达质粒，并表达出Gsr E5融合表达蛋白。

目的 在建立可靠的产前筛壹方法的同时，采用快速、简便、准确的产前诊断方法，防止唐氏综合征(DS)惠儿的出生。方法 采用酶联免疫方法剥定妊娠14～20w孕妇血清甲胎蛋白（AFP）和绒毛膜促性腺激素β亚基（β～HCG）浓度，结合孕妇年龄、孕周和体重，用计算机软件进行分析，得到每位孕妇所怀胎儿Ds风险系数。对筛查出胎儿詹氏综合征高风险孕妇，再利用2l号染色体上的6个多态性位点对其作产前基因诊断。姑果经产前筛查，在395例孕妇中发现10例胎儿唐氏综合征高风险孕妇，其中l例产前基因诊断为胎儿唐氏综合征，与染色体核型分析蛄果相符。蛄诒产前筛查结合基因多态性在唐氏综合征产前诊断中具有很好的应用价值。