Hepatitis A virus replication in tamarins and host immune response in relation to pathogenesis of liver cell damage

Hepatitis A virus (HAV) shedding in the faeces, appearance of HAV-Ag (antigen) in the liver, and development of humoral immunity to HAV have been studied in experimentally infected tamarins. The appearance of liver damage measured by transaminase elevation and histology, in relation to the above variables, suggests that the virus is not cytopathic and the immune system contributes to the production of liver cell damage. Preliminary data suggest that HAV replication may occur in the mucosa of the small intestine and in the liver.     

甲型肝炎患者血清特异性IgM、IgA及总抗体动态变化与临床意义

对６０例甲型肝炎患者血清抗甲型肝炎病毒（ＨＡＶ）ＩｇＭ、ＩｇＡ及总抗体从发病起进行了１年动态观测，并以病程、病情不同分组观察分析。发现病程、病情不同患者抗－ＨＡＶ－ＩｇＡ滴度变化不同，病程长、病情重者，该抗体下降缓慢，持续阳性时间稍长。     

体外细胞培养中甲肝病毒的连续传代及激光扫描共聚焦成像

观察甲肝病毒(HAV)在体外细胞培养中连续传代的特点及细胞内病毒荧光的激光扫描共聚焦成像。实验中采用了间接免疫荧光法(IF)与激光扫描共聚焦显微镜(LSCM)结合技术，并与ELISA进行比较。ISCM技术发现将NJ-3株HAV接种于PLC／PRF／5细胞1h后细胞表面有病毒吸附，2-4h病毒吸附量增多，4h后逐步减少。在病毒随细胞连续传代中，至第7代病毒增殖量可达到稳定状态并至少可连续传77代，感染病毒的细胞可达95％以上；细胞传代或病毒收获的最佳周期为5d；经多次冻存、复苏，仍保持良好的细胞形态和产毒性能。结果表明ISCM技术能更早地检出细胞表面吸附的少量病毒和胞浆内微弱的HAAs荧光，而ELISA则需要较多量病毒才能显示阳性。提示前者更适合于少量病毒时的定性，特别是在初次病毒分离时；后者则适合于病毒量较多时的整体定量。     

吸毒者HAV、HBV、HCV重叠感染现况及影响因素研究

目的 了解吸毒者HAV、HBV、HCV重叠感染现况及其影响因素。方法 采用现况调查的方法，随机抽取某男性戒毒所和某女性戒毒所中的吸毒者，用问卷方式调查吸毒者有关资料，并用ELISA法测定其血清中HAV-1gG、表面抗原和HCV抗体，用SPSS10．0进行数据统计分析。结果 吸毒者HAV、HBV、HCV总的重叠感染率为5．3％，男性、女性重叠感染率分别为7．5%(34／452)和2．2％(7／320)。不同的吸毒方式和不同文化程度男性、女性重叠感染率有显著性差异(P＜0．05)，是否接种乙肝疫苗在女性重叠感染率有显著性差异(P＜0．05)。结论 男性、女性的重叠感染率均与吸毒方式和文化程度有关，注射方式较非注射方式感染率高(P＜0．01)，文化程度越低，感染率越高(P＜0．05)。对吸毒者接种甲肝乙肝联合疫苗及进行文化教育是降低HAV、HBV、HCV重叠感染风险的有效途径。     

甲肝和水痘病毒在同一细胞中增殖动态的研究

目的 研究甲肝病毒(HAV)和水痘病毒(VZV)混合感染人胚肺二倍体细胞(2BS)病毒增殖动态。方法 将HAV和VZV间隔3周感染同一2BS细胞，同时HAV和VZV分别同步单独感染同一批次的2BS细胞。收获不同阶段的细胞培养物，电镜观察HAV和VZV在细胞内的超微结构和增殖数量；同时检测两种病毒的滴度水平。结果 在同一2BS细胞中观察到HAV和VZV的完整病毒形态，但VZV与单独感染的病毒达到增殖高峰期时间相比推迟4d左右，增殖达到高峰期时病毒滴度略低，但无显著性差异。结论 HAV和VZV可在同一2BS细胞中增殖，无明显干扰现象。     

Implementation of a hepatitis A prevention policy in haemophiliacs: results from the French cohort

In the early nineties, the occurrence of hepatitis A outbreaks in some patients with haemophilia in some countries led French health authorities to recommend hepatitis A virus (HAV) vaccination in HAV-seronegative haemophiliacs. The French 'Suivi thérapeutique National des Hémophiles' cohort permitted to assess the implementation of this recommendation by the analysis of the vaccinal process, i.e. HAV seropositivity assessment and vaccination of HAV-seronegative patients, in a survival approach. In a subgroup of 812 patients diagnosed earlier than 1990 (prevalent cohort), the implementation of vaccinal process increased quickly from 0% in 1993 to 41.8% in 1994 and to 71.2% in 1996, suggesting a 'notification effect'. The vaccinal process was associated to three cofactors in a Cox model analysis (age, severity of haemophilia, centre of treatment). No infection was observed during the survey in this group. In another subgroup of 201 boys born since 1993 (incident cohort), 27.5% and 15.4% patients remained exposed to the risk at 3 and 5 years from diagnosis respectively, again with a 'centre effect', which might be linked to various factors such as regain in confidence for products or economic reasons. Only five infectious seroconversions were assessed over the 7-year survey, which represents 14.5 cases per 1000 person-year incidence without any relationship with products. Our data combined with the contemporary hepatitis A epidemiology and the current safety of anti-haemophilic concentrates, should lead to a new assessment of the risk of hepatitis A in haemophiliacs. We suggest that among patients with bleeding disorder, as well as in other populations, HAV prevention policy might be stressed on those who already suffer from chronic liver disease and/or travel in endemic countries.     

甲型肝炎早期诊断──酶联捕获法检测唾液IgM－抗HAV研究

对７０例急性肝炎患者，用酶联捕获法检测血清和唾液ＩｇＭ－抗ＨＡＶ，证实为甲型肝炎者５４例，包括甲、乙型肝炎混合感染１９例。５４例患者血清与唾液ＩｇＭ－抗ＨＡＶ阳性符合率９２．６％（５０／５４）。在８１例对照组中，血清与唾液均未测出ＩｇＭ－抗ＨＡＶ，两者阳性及阴性总符合率９７．４％。（１４７／１５１）。唾液抗体滴度１０－１至１０－３比血清抗体滴度１０－３至１０－６为低。但低滴度并不影响酶联反应的结果，本组资料表明病人唾液ＩｇＭ－抗ＨＡＶ阳性可做为甲型肝炎早期诊断的依据，唾液标本具有采集容易，操作简便，检测结是容易判定等优点，因而可用于基层医疗单位。     

Prevalence of hepatitis A among drug users in north-eastern Italy. Is vaccination necessary in low prevalence areas?

BACKGROUND: The authors report on the prevalence of, and risk factors for, hepatitis A virus (HAV) in a group of drug users in Italy. METHODS: 404 heroin users were recruited and compared with a control group of 107 subjects in the general population. RESULTS: Drug users born in north-eastern Italy have a prevalence of anti-HAV similar to the control group. A much higher prevalence was found in drug users born in southern Italy. CONCLUSION: The similar prevalence of anti-HAV in drug users born in north-eastern Italy and in the general population, suggests that their lifestyle does not involve a substantial additional risk of HAV. The much higher prevalence found in drug users born in southern Italy is more likely to be related to infection during infancy.     

RT—PCR法检测甲肝疫苗滴度

建立快速灵敏特异的甲肝减毒活疫苗滴度的ＲＴ－ＰＣＲ检测法。方法：以编码甲肝病毒（ＨＡＶ）ＶＰ３羧基端的基因区为目标区，运用ＲＴ－ＰＣＲ法对甲肝疫苗病毒进行检测，并与ＴＣＩＤ５０检测法进行比较。结果：ＲＴ－ＰＣＲ法灵敏度和特异性均与ＴＣＩＤ５０法相似，...