Complete genomic sequences for hepatitis C virus subtypes 6e and 6g isolated from Chinese patients with injection drug use and HIV-1 co-infection

In one of our recent studies, two HCV genotype 6 variants were identified in patients from Hong Kong and Guangxi in southern China, with injection drug use and HIV-1 co-infection. We report the complete genomic sequences for these two variants: GX004 and

High prevalence of HIV-1 and hepatitis C virus coinfection among injection drug users in the southeastern region of Yunnan, China

The southeastern region of Yunnan province is a key site for drug trafficking and HIV-1 infection spread from the west of Yunnan and Laos to southeastern China. To investigate the prevalence of HIV-1 infection and hepatitis C virus (HCV) coinfection among injection drug users (IDUs) in southeastern Yunnan, three cohorts of 285 addicts, including 242 IDUs and 43 oral drug users, living in the cities of Gejiu and Kaiyuan and the county of Yanshan were studied. HIV-1 and HCV infections were detected by enzyme-linked immunosorbent assay and/or polymerase chain reaction. Data on the age, sex, risk behavior, drug use history, employment, ethnic background, and marriage status were obtained by interview. The overall prevalence of HIV-1 infection was 71.9%. The rate of HCV coinfection among 138 HIV-1-infected IDUs was 99.3%. Most HIV-infected IDUs were 20 to 35 years old (86.7%) and were ethnic Han (75.9%), suggesting that the epidemic in Yunnan is no longer confined to non-Han ethnic minorities, HIV prevalence in female IDUs (81.2%) was significantly higher than in male IDUs (68.2%) (p <.05). The prevalence of HIV infection reached 68.4% after 1 year of injection drug use. Needle/syringe sharing is the major high risk factor for the spread of HIV-1 and HCV infections. Large-scale educational campaigns are urgently needed to reduce the spread of HIV and HCV infection in these regions.

丙型肝炎病毒基因和蛋白结构研究进展

　估计全球约有117 亿人口感染丙型肝炎,是一种严重影 响人类健康的传染病。丙型肝炎的病原为丙型肝炎病毒 (Hepatitis C Virus ,HCV) 。1989 年Choo 等人首先获得HCV 基因组的cDNA 全序列,使HCV 成为病毒学史上第一个首先 通过基因克隆技术确认的病毒〔1 ,2〕。此后,HCV 的分子生物 学研究进展迅速。现将HCV 病毒分子结构的最新研究状况 做一综述。

丙型肝炎病毒(HCV)株的全基因组序列测定: 完成HCV 基因型6 全套17 个亚型基因组的测序

丙型肝炎病毒（Hepatitis C virus, HCV）的全基因组序列测定，曾经由于许多方面 的条件限制而难于完成。但是，其对于研究HCV 分子病毒学、流行病学、进化和致 病性却至关重要，特别是在临床应用中，不同序列的基因型决定α-干扰素治疗的不同 效果。在本研究完成之前，HCV 基因型6 仅有6 个亚型有其全基因组序列。因此， 本研究的主要目的在于，测定HCV 变异株代表基因型6 其余的11 个亚型和新亚型的 全基因组序列，并深入分析。 本研究从样品分别来自于中国、泰国，和在美国及加拿大生活的东南亚国家移民 的HCV 感染者。因为样品有限，改良传统的PCR 方法，摸索出“桥”和“岛”DNA 全序列扩增法，从每例样品100μl 血清或从100μl 血清中获得的cDNA 中测定了13 个HCV 全基因组核苷酸序列。 以来源于Genbank 的已知基因型6 的七个全长序列为参考对所测定的13 个亚型 全序列进行共同分析显示，这些全基因组核苷酸的两两比较相似率变化范围为 71.9%--82.7%，著地， 这四对序列间的相同率高于标准定义的HCV 基因亚型之间的 范围值75%-80%。为了进一步理解和证实这些亚型间的遗传相似性，本研究还测定 了代表这4 对亚型的病毒原型株的全基因序列，结果显示了相同的核苷酸水平上的变 异范围，这为HCV 基因亚型的分类提供了新的认识，亦强调了全长序列对于分类的 重要性。 从系统发育方面的分析证实，本研究所测得的13 个分离株都属于基因型6。在系 统发育树上，每个病毒株代表一个独立的枝。并形成了高度分化的HCV 基因型6 分 枝，从而清楚显示，各亚型的独立分布。本研究至此完成了基因型6 中17 个亚型的 全序列测定，而km41 和gz52557 因缺乏其临床上和流行病学上的多个感染病例的证 实，而继续保留其亚型未命名状态。结合来源于Los Alamos HCV database 的基因型6 的已知部分序列的变异株进一步分析，发现各相近亚型变异株均来自东南亚或东南亚国家移民，这提示了这些HCV 的相同感染源。 为了探讨HCV 夫妻间传播的可能性，本研究还测定了来自于泰国的两位感染 HCV 的献血员及其感染HCV 的配偶。这4 个基因序列C-0044 和C-0046 之间核苷 酸相同率为98.1%，而C-0185 和 C-0192 之间为97.8%。文献研究感染HCV 的夫妇 间的部分亚基因序列的相同率为96.3%至100%，本研究结果与此范围相符，并第一 次用全基因组序列提示了HCV 在夫妻间传播的可能性。 本研究还测定了基因型6 的另一个变异株的全基因组序列：HK6554，香港的某患 者，与上文中的GX004 一起，均为静脉吸毒者，并共同感染了HCV 和HIV-1。分析 结果还表明了一种趋势，即是在中国南方，基因亚型6e 有从以前的地方性传播方式 转为现有的流行性传播方式。这种转变可能由于静脉吸毒感染HCV 的人群的网络传 播而加快。 综上，本研究用传统PCR、简并引物结合链特异引物的方法有效地测定了共21 个病毒株的全基因序列。该方法也可用于其它分子流行病学的研究，特别在测定珍贵 的病毒序列然而样品量又受限时。本研究所测定的全基因组序列代表HCV 中最古老、 分化最多、地方性传播、又可能动物源性的基因型6 的全套17 个亚型。这有助于进 一步理解HCV 基因亚型的分类意义、更准确评价HCV 的进化和起源，亦有助于发 现HCV 新的变异株和提高临床诊断、治疗，为将来HCV 的流行及公众健康的预测、 预防和疫苗的制备奠定了坚实的分子遗传学基础。

Environmental enrichment and chronic restraint stress in ICR mice: Effects on prepulse inhibition of startle and Y-maze spatial recognition memory

In most studies regarding the improving or therapeutical effects induced by enriched environment (EE), EE was performed after the stress treatment or in patients with certain diseases. In the current study, the effects of chronic restraint stress (6 h/day) in mice living in an enriched environment or standard environment (SE) were tested. Mice were randomly divided into 4 groups: non-stressed or stressed mice housed in SE or EE conditions (SE, stress + SE, EE, stress + EE). Prepulse inhibition (PPI) of startle was tested after the 2 weeks or 4 weeks stress and/or EE treatment and 1 or 2 weeks withdrawal from the 4 weeks treatment. After the 4 weeks treatment, spatial recognition memory in Y-maze was also tested. The results showed that EE increased PPI in stressed and non-stressed mice after 2 weeks treatment. No effect of EE on PPI was found after the 4 weeks treatment. 4 weeks chronic restraint stress increased PPI in mice housed in standard but not EE conditions. Stressed mice showed deficits on the 1 h delay version of the Y-maze which could be prevented by living in an enriched environment. Our results indicated that living in an enriched environment reversed the impairing effects of chronic restraint stress on spatial recognition memory. However, EE did not change the effects of stress on PPI. (C) 2010 Elsevier B.V. All rights reserved.

Chronic effects of water-borne PFOS exposure on growth, survival and hepatotoxicity in zebrafish: A partial life-cycle test

Perfluorooctane sulfonate (PFOS) is widely distributed and persistent in the environment and wildlife. The main aim of this study was to investigate the impact of long-term exposure to low concentrations of PFOS in zebrafish. Zebrafish fry (F-0, 14d post-fertilization, dpf) were exposed via the water for 70d to 0 (control), 10, 50 and 250 mu g L-1 PFOS, followed by a further 30d to assess recovery in clean water. The effects on survival and growth parameters and liver histopathology were assessed. Although growth suppression (weight and length) was observed in fish treated with high concentrations PFOS during the exposure period, no mortality was observed throughout the 70d experiment. Embryos and larvae (F-1) derived from maternal exposure suffered malformation and mortality. Exposure to 50 and 250 mu g L-1 PFOS could inhibit the growth of the gonads (GSI) in the female zebrafish. Histopathological alterations, primary with lipid droplets accumulation, were most prominently seen in the liver of males and the changes were not reversible, even after the fish were allowed to recover for 30d in clean water. The triiodothyronine (T-3)) levels were not significantly changed in any of the exposure groups. Hepatic vitellogenin (VTG) gene expression was significantly up-regulated in both male and female zebrafish, but the sex ratio was not altered. The overall results suggested that lower concentrations of PFOS in maternal exposure could result in offspring deformation and mortality. (c) 2008 Elsevier Ltd. All rights reserved.

Rickettsia-like organism infection in a freshwater cultured fish Ophiocephalus argus C. in China

From 2001 to 2002, a new and emergent infectious disease of Ophiocephalus argus occurred in a fishery in Hubei Province, China, with an incidence of 60% similar to 70% and a mortality as high as 100 %. The diseased fish showed an enlarged abdomen, the millet-like nodules in internal organs, and the swollen kidney which was composed of 5 similar to 10 sarcoma-like bodies in cream or gray-white colour or ulcerated into beandregs-like substance. Light microscopic observation revealed the basophilic or acidphilic inclusions in cytoplasm of the cells and the granulomas, a diffusive chronic inflammation in internal organs. Further analysis under an electron microscope indicated that the intracytoplasmic inclusions were rickettsia-like organisms (RLOs) that are either spherical or coccoid, with variable size, ranging from 0.5 similar to 1.5 mum in diameter, and enclosed within membrane-bound cytoplasmic vacuoles. RLO had a central nucleoid region with some fine filamentous structures and an electron-dense granule. Its cytoplasm contained abundant ribosomal bodies. Occasionally, RLO appeared to be divided by binary fission. RLOs were also observed in the homogenized tissue of infected fish. The results suggested that the death of cultured O. argus was caused by RLO infection.

Dynamics of microcystins-LR and -RR in the phytoplanktivorous silver carp in a sub-chronic toxicity experiment

A sub-chronic toxicity experiment was conducted to examine tissue distribution and depuration of two microcystins (microcystin-LR and microcystin -RR) in the phytoplanktivorous filter-feeding silver carp during a course of 80 days. Two large tanks (A, B) were used, and in Tank A, the fish were fed naturally with fresh Microcystis viridis cells (collected from a eutrophic pond) throughout the experiment, while in Tank B, the food of the fish were M. viridis cells for the first 40 days and then changed to artificial carp feed. High Performance Liquid Chromatography (HPLC) was used to measure MC-LR and MC-RR in the M. viridis cells, the seston, and the intestine, blood, liver and muscle tissue of silver carp at an interval of 20 days. MC-RR and MC-LR in the collected Microcystis cells varied between 268-580 and 110-292 mug g(-1) DW, respectively. In Tank A, MC-RR and MC-LR varied between 41.5-99.5 and 6.9-15.8 mug g(-1) DW in the seston, respectively. The maximum MC-RR in the blood, liver and muscle of the fish was 49.7, 17.8 and 1.77 mug g(-1) DW, respectively. No MC-LR was detectable in the muscle and blood samples of the silver carp in spite of the abundant presence of this toxin in the intestines (for the liver, there was only one case when a relatively minor quantity was detected). These findings contrast with previous experimental results on rainbow trout. Perhaps silver carp has a mechanism to degrade MC-LR actively and to inhibit MC-LR transportation across the intestines. The depuration of MC-RR concentrations occurred slowly than uptakes in blood, liver and muscle, and the depuration rate was in the order of blood > liver > muscle. The grazing ability of silver carp on toxic cyanobacteria suggests an applicability of using phytoplanktivorous fish to counteract cyanotoxin contamination in eutrophic waters. (C) 2003 Elsevier Ltd. All rights reserved.