慢性HBV感染患者bcp/pc区点突变模式、pres区缺失及其临床意义

目的阐明HBV(hepatitis B virus,HBV)感染患者不同临床阶段bcp/pc(basic core promoter,BCP/precore,PC)点突变模式及pres区缺失突变规律,并探讨其临床意义。方法慢性HBV感染患者180例,其中,无症状HBV携带者13例,慢性乙型肝炎者75例,HBV相关肝硬化及肝癌分别为62、30例。Qiagen法提取血清HBV-DNA,常规PCR扩增目的基因,纯化PCR产物ABI377DNA自动测序仪直接双向测序。直接测序失败者,回收目的 DNA与PMD-18T载体连接,克隆质粒双向测序。DNAStar软件包的SeqMan软件进行生物信息分析。结果 Bcp/pc区点突变包括nt1753、nt1762、nt1764、nt1776、nt1803、nt1846、nt1896。HBV携带者、慢性乙型肝炎、HBV相关肝硬化及肝癌患者nt 1762(nt 1764)点突变率分别为7.7%、68.0%、72.7%(68.0%)及90.9%(81.8%),肝癌患者G1896A突变频率占54.6%。A1762T+G1764A联合突变占36%;A1762T、G1764A、G1896A联合突变占11%;T1753A/C、A1762T、G1764A、G1896A发生率为7%。克隆测序显示,肝硬化及肝癌患者bcp区起始点A1727G点突变率分别为72%、63%。HBeAg阴性患者存在更多的基因变异(P=0.022),G1776A和G1896A突变是HBeAg阴性的独立预测因素(P<0.05)。Bcp区点突变与HBeAg阴性无明显关系。肝硬化和肝癌患者pres基因缺失突变频率最高,肝癌及肝硬化患者pres1、pres2及pres1+s2缺失频率分别为7.1%、71.4%、7.1%及41.2%、58.8%、29.4%(P<0.05)。结论 A1727G、A1762T、G1764A及A1762T/G1764A联合突变、pres缺失在HBV相关肝硬化及肝癌患者多见,可能是肝脏疾病进展的危险因素,G1776A和G1896A突变是HBeAg阴性的独立预测因素。Bcp/pc点突变及pres区缺失可能为肝癌发生的早期预测因素,值得进一步研究。     

CD133多克隆抗体制备及肿瘤干细胞鉴定

目的 制备肿瘤干细胞标志性蛋白CD133的多克隆抗体,为进一步研究肿瘤组织中肿瘤干细胞的生物学特性以及筛选肿瘤干细胞、制备肿瘤干细胞的小鼠模型奠定基础.方法 以人CD133蛋白细胞外膜表面肽段为抗原,免疫新西兰大白兔制备多克隆抗体,进而用其对肿瘤组织进行Western blot以及免疫组化染色.结果 Western blot证实该抗体可以识别过表达的myc-CD133以及内源性CD133,进一步免疫组化结果显示该抗体可以识别恶性胶质瘤中的肿瘤干细胞.结论 成功制备高效、特异的CD133多克隆抗体,该抗体可以用于肿瘤组织的免疫染色及肿瘤干细胞的筛选.     

野牡丹止痢片的薄层鉴别研究

目的建立野牡丹止痢片的薄层鉴别方法。方法通过对吸附剂、展开剂、显色剂、点样量的优化和对相对湿度、温度等影响因素的考察,确定最佳的薄层色谱条件。结果最佳条件为:以硅胶H为吸附剂,二氯甲烷-甲酸乙酯-甲酸(6:3:1)为展开剂1,%FeCl3乙醇溶液为显色剂,点样量为供试品溶液与对照药材溶液4μl、对照品溶液2μl;相对湿度、温度对实验结果无明显不良影响。结论所建立的方法操作简便、分离快速、专属性强、耐用性好,可用于该制剂的质量控制。     

Increased rifampicin resistance in blood isolates of meticillin-resistant Staphylococcus aureus (MRSA) amongst patients exposed to rifampicin-containing antituberculous treatment

The aim of this study was to determine the rifampicin (RIF) resistance rate of meticillin-resistant Staphylococcus aureus (MRSA) amongst patients with MRSA bacteraemia who have or have not been exposed to RIF-containing antituberculous (anti-TB) treatment. From 2000 to 2008, patients with MRSA bacteraemia and previous exposure to RIF-containing anti-TB therapy were selected. Patients matched for sex, age and time of culture of MRSA bacteraemia but without exposure to anti-TB therapy were selected as a control group. A total of 139 patients, comprising 49 with RIF exposure and 90 without RIF exposure, were analysed. The RIF resistance rate was higher in patients with previous RIF exposure (61.2% vs. 20.0%; P<0.001). The minimum inhibitory concentration of RIF that inhibited 50% of MRSA isolates (MIC(50)) for the study group was also higher (128 mg/L vs. 0.015 mg/L; P<0.001). The mortality rate was higher in the study group (59.2% vs. 41.1%; P=0.041). MRSA isolates recovered from patients with current usage of a RIF-containing anti-TB regimen were more likely to be resistant to RIF (87.5% vs. 36%; P=0.001), with higher MIC(50) values (256 mg/L vs. 1mg/L; P=0.002), and resulted in a higher mortality rate than isolates from patients with remote usage of an anti-TB regimen (79.2% vs. 40%; P=0.005). Multivariate analysis showed that current anti-TB drug usage was the only risk factor for RIF resistance [odds ratio (OR)=7.457, 95% confidence interval (CI) 1.581-35.167] and mortality (OR=7.201, 95% CI 1.583-32.766). Given the high rate of RIF resistance in patients with prior anti-TB treatment, RIF susceptibility testing should be performed before considering combination treatment of RIF in MRSA infection.