为探讨庚型肝炎病毒（GBV-C/HGV）感染有无致病性，利用GBV-C/HGV不同基因区序列设计并优选出5套引物，建立起灵敏、特异的HGV逆转录套式聚合酶链反应（RT-nPCR）检测方法。应用此方法对临床上诊断为乙型肝炎及慢性丙型肝炎的患者，按照其血清中HGV RNA的阳性与否分组，并进行病例对照研究。结果显示，单独HBV或HCV感染的肝炎患者与混合HGV感染的肝炎患者的血清肝功能异常指标无显著性差异（P>0.05）。因此，病毒性肝炎患者混合感染HGV后，未发现加重HBV或HCV感染的肝功能异常程度，不支持HGV有明显的嗜肝致病性。

目的 探讨乳酸杆菌（Lactobacillus, LB）对小鼠宫颈鳞癌U14的抗癌作用及对U14细胞凋亡的诱导作用。方法 建立KM和615近交系鼠U14移植瘤动物模型，并随机分组，检测实验组与对照组小鼠的瘤体平均重量和抑瘤率；采用TUNEL法检测细胞凋亡指数（AI）。结果 与对照组比较，嗜酸乳杆菌（L. acidophilus, LA）对两种品系小鼠移植瘤的抗癌作用，差异均具有非常显著性（P<0.01）；提前给予LA组小鼠，其移植瘤生长速度显著慢于对照组（P<0.01）；LA及干酪乳杆菌（L. casie, LC）对于小鼠U14移植瘤，亦具有显著抗癌作用（P<0.01），但LA与LC两组间的抗癌作用，差异无显著性（P>0.05）；在615系小鼠模型组、LA及顺铂（Diaminodichloroplatin, DDP）组小鼠之间，AI的差异具有非常显著性（P<0.01）。结论 LB对小鼠宫颈鳞癌具有显著的抗癌作用，可有效地抑制肿瘤的发生和发展，其抗癌作用机制中包括诱导肿瘤细胞凋亡。

目的 调查我国输血后丙型肝炎病毒（HCV）感染的自然史及其影响预后的因素。方法 河北省赵县某农村单采血浆还输血细胞献血员（简称献浆员），于1993年8月经现场调查及血清学检测被诊断为HCV感染者172例，未进行任何抗病毒治疗，2002年7月对其HCV感染9年后的转归以及影响转归的因素进行调查分析。结果　在172例HCV感染者中,9年后2例死于晚期肝病，4例死于脑出血，1例意外死亡，9年后实际追踪到142例,失访率为1319%（23/165）,肝病的病死率为112%（2/172）。该组HCV感染者的慢性化率为9115%（130/142），自然阴转率为814%（12/142）。在持续性HCV感染者中，经B型超声检查提示，肝硬化率为311%（4/130）；重度肝炎占619%（9/130）；中度肝炎3612%（47/130）；轻度5311%（69/130）；另有1010%（13/130）诊断为脂肪肝。HCV RNA阳性组的丙氨酸氨基转移酶、天冬氨酸氨基转移酶、和γ谷氨酸转肽酶的平均水平显著高于阴性组（P<01001）。HCV/HBV混合感染者肝硬化进程显著快于单独HCV感染（P<0105）。结论 输血后HCV感染者的慢性化率远远高于乙型肝炎病毒（HBV）感染者，HCV/HBV混合感染者较单一感染者预后差。

AIM: There is limited information on the natural history of HCV infection in China. We investigated the outcome of HCV infection after nine-year follow-up and the risk factors in blood donors in China in order to provide the foundation for prevention and therapy. METHODS: A total of 172 cases of HCV infection with anti-HCV positive and ALT abnormality were enrolled in the archives when was screened blood in Hebei Province in 1993. In them 142 blood donors were followed up till July 2002. No antiviral treatment was applied to them during the period of infection. In the present study, anti-HCV, HCV-RNA and aminotransferase were detected and genotyping was conducted by the method of restriction fragment length polymorphism (RFLP). B-type ultrasound detection was performed in all the patients. Age, sex, alcohol consumption and clinical symptoms were questioned. RESULTS: After nine years' follow-up, 10.56% (15/142) of the cases were negative for anti-HCV and 16.42% (12/134) of them were negative for HCV-RNA. The genotypes 1b, 2a and 1b/2a were 91.07%, 6.25% and 2.68% respectively. Twelve cases (8.45%) were negative for both HCV-RNA and anti-HCV. The rate of chronicity in this group was 83.58% (112/134), and the rate of viral spontaneous resolution was 16.42% (22/134). The mean level of ALT, AST, γ−GT in HCV RNA positive cases was significantly higher than that in HCV RNA negative cases (P<0.001). The abnormal rate of ALT and/or AST in male donors was significantly higher than that in female donors (P=0.005). The rate of progression to liver irrhosis from chronic hepatitis C was significantly higher in the cases of super-infection with HBV than that in the cases of single HCV infection. Overdose alcohol consumption promoted the progression to chronicity. CONCLUSION: This area (Hebei Province) has a higher rate of chronicity in HCV infection, and measures should be taken to prevent its progression to serious liver diseases, especially for patients super-infected with HCV and HBV.

AIM: To investigate the effect of interleukin-12 p40 gene (IL12B) 3'-untranslated region polymorphism on the outcome of HCV infection. METHODS: A total of 133 patients who had been infected with HCV for 12-25 (18.2

AIM: To determine the pathogenicity of GB virus C (GBV-C) on liver and the effects of its co-infection on the clinical features and prognosis of patients with hepatitis B and C. METHODS: Cross-sectional study was carried out in 413 patients with acute, chronic hepatitis B or liver cirrhosis, and in 67 hemodialysis patients. A 20-month prospective cohort study was carried out in 95 hepatitis B and 80 hepatitis C patients. A reverse transcriptase nested polymerase chain reaction (RT-nPCR) of the 5'-noncoding region was used to detect circulating GBV-C RNA. Liver function was determined by an automated analyzer for all patients. RESULTS: The prevalence of GBV-C in the high-riskpopulations with the virus transmitted via blood was high, ranging from 16.2 to 28.8%. Co-infection with GBV-C in hepatitis B patients did not affect the clinical features of the disease or liver function. The dialysis patients infected with GBV-C alone did not develop functional changes to the liver. Prospective cohort study showed that GBV-C co-infection did not affect the clinical features, prognosis or negative serum conversion rate of chronic hepatitis B and C. CONCLUSION: The results suggest that GBV-C has no marked pathogenicity on liver, so it may not be a hepatitis virus.