磷甲酸三纳抗鸭乙肝病毒作用的研究

用嗜肝病毒动物模型对磷甲酸三钠的抗乙肝病毒作用机理和效果作了初步的研究。１８只持续感染鸭乙肝病毒的麻鸭腹腔内隔日注射２００－４００ｍｇ／ｋｇ磷甲酸三钠共６周，给期间分别取血清和肝细胞以斑点杂交和Ｓｏｕｔｈｅｒｎｂｌｏｔ试验检测乙肝病毒ＤＮＡ。结果显示；尽管用药过程中血清病毒ＤＮＡ滴度有一过性下降，但肝内仍显示出活跃的病毒复制。表明磷甲酸三钠的抗乙肝病毒作用机理主要不是在于抑制病毒ＤＮＡ或ＲＮＡ聚合     

无环鸟苷在治疗慢性乙肝中的应用

乙肝病毒感染的标志包括:乙肝表面抗原(HBsAg),核心抗原(HBcAg),e抗原(HBeAg)及其相应的特异抗体,HBc抗体及乙肝病毒DNA多聚酶(HBV-DNAP)。肝细胞的损害与乙肝病毒(HBV)在肝细胞内的复制密切相关。当HBV活跃增殖时,循环内出现HBeAg、DNA多聚酶(DNAP)和HBV DNA,此时往往可见临床症状,肝功能异常及肝组织病变。HBV中止复制对,血清出现抗HBe,病毒的上述几个指标从血中消失,病情缓解。如果血中HBsAg持续阳性,说明HBV-DNA     

两种抗乙肝病毒的新药

随着病毒分子生物学研究的不断进展,已知乙肝病毒(HBV)复制分为转录期、逆转录期及DNA复制期3个阶段。因此,阻断病毒复制环节中不同靶点是开发新的抗HBV药物的方向。抗病毒作用靶点的重点在于抑制病毒复制酶,清除细胞核内的病     

膦甲酸钠对HepG 2.2.15细胞分泌HBsAg、HBeAg和HBV DNA的抑制作用

膦甲酸钠为广谱抗病毒药物，能直接抑制病毒特异的DNA多聚酶和逆转录酶，对Ⅰ、Ⅱ型单纯疱疹病毒、巨细胞病毒等有抑制作用。临床用于抗乙肝病毒，尤其是用于治疗重型肝炎。本文采用HepG2．2．15细胞模型进行了膦甲酸钠的体外抗乙型肝炎病毒作用的研究。     

用PCR检测常规杂交试验HBV DNA阴性的慢性乙型肝炎儿童血清和肝组织中的HBV DNA

作者取慢性乙型肝炎患儿血清216份,肝组织活检样品104份,分别用斑点印迹法和DNA印迹杂交法检测乙型肝炎病毒(HBV)DNA。结果87份血清和40份肝活检组织未检出病毒DNA。将这些阴性样品再用聚合酶链反应(PCR)法检测HBV DNA。结果87份血清中73份PCR阴性,其中HBeAg阳性14份,抗-HBe阳性56份,HBeAg和抗     

慢性乙型病毒性肝炎的临床治疗分析

目的探讨干扰素治疗慢性乙型病毒性肝炎的疗效。方法选择2008年6月至2009年12月慢性乙肝患者106例。以谷丙转氨酶（ALT）、乙肝五项、乙肝病毒DNA（HBV DNA）为观察指标,比较不同治疗方案对指标的影响。结果治疗3个月,慢性乙肝患者血清HBeAg/抗HBeAg转换率分别为48.48%;慢性乙肝患者血清HBVDNA的阴转率分别为75.8%。结论其抗病毒治疗效果优于单用干扰素组。     

聚乙二醇干扰素α-2a抗病毒过程中cccDNA的变化

目的探讨聚乙二醇干扰素α-2a对慢性乙型肝炎患者肝组织中共价闭合环状DNA(cccDNA)的影响。方法将76例慢性乙型肝炎患者分为对照组和治疗组,对照组应用普通干扰素,治疗组给予聚乙二醇干扰素α-2a治疗48周,观察肝组织中乙肝病毒(HBV)cccDNA检出率和含量,肝组织和血清HBV DNA病毒含量及血清ALT、AST和总胆红素(TBIL)的含量。结果 2组治疗后HBV cccDNA检出率和含量均明显降低(P<0.05),肝组织和血清HBV DNA病毒含量及血清ALT、AST和TBIL的含量均明显降低(P<0.05),治疗组治疗后降低量更显著(P<0.05)。结论聚乙二醇干扰素α-2a对慢性乙型肝炎患者肝组织中cccDNA的清除疗效显著优于普通干扰素。     

磷甲酸三钠体外抗巨细胞病毒及柯萨奇B_4病毒作用

磷甲酸三钠（ＰＦＡ）是一种通过选择性抑制病毒聚合酶而实现抗病毒作用的新药。本研究观察了ＰＦＡ抑制巨细胞病毒（ＣＭＶ）和柯萨奇Ｂ４（ＣＢ４）病毒在细胞培养中诱导的细胞病变作用。结果表明．ＰＦＡ能有效抑制巨细胞病毒复制．其５０％抑制浓度为３９．４μｍｏｌ·Ｌ－１，在５００μｍｏｌ·Ｌ－１浓度下对ＣＭＶ的抑制指数为１０００。但对柯萨奇Ｂ４病毒的抑制作用甚微。     

桑黄调节细胞因子及其在抗肝纤维化中的意义

目的 研究桑黄调节细胞因子与抗肝纤维化。方法 以四氯化碳诱导大鼠肝纤维化，观察桑黄对肝纤维化的治疗作用；体外培养人外周血单个核细胞(PMNCs)，考察桑黄对其产生γ-干扰素的增强作用。结果 桑黄能抑制肝纤维化大鼠肝脏内胶原纤维增生，明显降低血清氯基酸转移酶水平和胶原成分含量，降低血清白细胞介素-4水平，而显著提高血清γ-干扰素水平；体外实验表明，桑黄能促进PMNCs生成γ-干扰素，且呈浓度依赖性特征。结论 桑黄具有明显的抗肝纤维化作用，诱生γ-干扰素可能是其作用机理之一。     

乙型肝炎病毒表面抗原低水平阳性血清的病毒核酸载量分析

目的：探讨分析血清中乙型肝炎病毒表面抗原（HBV-HBsAg）低水平阳性与病毒核酸载量的关系。方法 HBsAg弱阳性的患者3632例,通过酶联免疫吸附试验（ELISA）检测血清（HBsAg）、使用荧光定量聚合酶链反应（FQ-PCR）检测血清乙型肝炎病毒DNA（HBV-DNA）。结果3632例HBsAg弱阳性的患者病毒DNA检出率为80.55%,病毒核酸载量的平均值为7.305。结论乙型肝炎病毒表面抗原低水平阳性对乙型肝炎的诊断不具有代表性,只能能说明体内含有乙肝病毒外壳,还需要结合血清病毒核酸载量检测来判断患者体内是否具有乙肝病毒DNA。只有在HBsAg阳性且合并病毒核酸载量值异常时,才有助于乙型病毒性肝炎的诊断和疗效的评估。     

Antiviral therapeutic efficacy of foscarnet in hepatitis B virus infection

Foscarnet (PFA), a viral DNA polymerase inhibitor, is a clinical agent for herpes viruses. The goal of the study was to evaluate the therapeutic efficacy of PFA in hepatitis B virus (HBV) infection. Intravenous infusion of PFA (1 g/day) for 4 weeks significantly reduced serum HBeAg (p<0.01) and HBV DNA copies (p<0.05) in 31 patients who were diagnosed with active chronic HBV infection (CHB) and had not received antiviral treatment previously. Alanine aminotransaminase (ALT), aspartate aminotransaminase (AST) and gamma glutamyl transpeptidase (gamma-GT) of the patients declined (p<0.001, 0.001 and 0.01, respectively). Kidney function (blood creatinine and urea nitrogen) remained unchanged. Another 21 lamivudine-resistant CHB patients with mutations at the tyrosine-methionine-aspartate-aspartate motif (YMDD) displayed a response to PFA similar to that mentioned above, with reductions in HBeAg (p<0.05), HBV DNA (p<0.01) and liver enzymes (ALT and AST, p<0.001; gamma-GT, p<0.05). Moreover, PFA reduced serum HBeAg (p<0.01), HBV DNA (P<0.05), AST (p<0.05) and ALT (p<0.02) in a cohort of 13 severe CHB patients with advanced liver damage. PFA was also evaluated in vitro and in vivo. PFA inhibited HBV DNA replication in HBV-transfected human HepG2 cells (2.2.15 cells) with reduced amount of HBV RC-DNA and DS-DNA. In the duck HBV-infected ducklings, PFA reduced viral DNA and duck HBsAg in the serum (p<0.01 for both).     

Antiviral effects of PNA in duck hepatitis B virus infection model

AIM: To study the efficacy of antiviral treatment with PNA for the duck model of HBV (DHBV)-infected ducks. PNA is a 2-amine-9-(2,3-dideoxy-2,3-dihydro-beta-D-arabinofuranosyl)-6-methoxy-9H-purine. METHODS: The Sichuan Mallard ducklings in the hepatitis B virus model were treated with PNA, a new antiviral agent. DHBV DNA from the blood serum and liver tissues were measured at 0, 5, and 10 d during the treatment and at 3 d withdrawal by real-time PCR. The duck hepatitis B surface antigen (DHBsAg) in the liver cells was observed by Immunohistochemistry (IHC). Pathological changes in the liver tissues were also observed. Control group I was administered with distilled water and control group II was administered with 3-thiacytidine. Treatment group I was administered with PNA at a dose of 40 mg/kg and treatment group II was administered perorally (po) with PNA at a dose of 80 mg/kg. Treatment group III was administered with PNA at a dose of 20 mg/kg and treatment group IV was intravenously administered with PNA at a dose of 40 mg/kg. Each group contained 15 ducklings. RESULTS: PNA can significantly lower the DHBV replication levels in serum and liver. Compared with control group II, there were no significant differences in inhibiting efficacy in treatment groups I and III (P>0.05) and there were significant differences in inhibiting efficacy in treatment groups II and IV (P<0.05). Interestingly, significant differences were observed at 3 d withdrawal. The DHBV replication levels in each group slightly increased at 3 d withdrawal, but rebounded slightly in the PNA treatment groups than in control group II (P<0.05). The DHBV replication levels in the treatment groups were lower than in control group I. The DHBV replication levels in sera had a positive relationship with that in the liver, but the DHBV replication levels in the liver was lower than that in sera. Pathological changes in the treatment groups were obviously improved and the changes were associated with liver viral DNA levels. CONCLUSION: The results demonstrate that PNA is a strong inhibitor of DHBV replication in the DHBV-infected duck model.     

拉米夫定治疗慢性乙型病毒性肝炎的新进展

目的:探索拉米夫定治疗慢性乙型病毒性肝炎的机制和优点。方法:总结拉米夫定抑制乙型病毒性肝炎复制的分子机制,研究近年来大量拉米夫定抗病毒治疗的大规模临床研究以深入研究拉米夫定在慢性乙型病毒性肝炎治疗中的特点、优势和安全性。结果:拉米夫定(LMV)具有高效的抗HBV活性,对乙肝病毒有长期稳定的抑制作用,长期应用可引起病毒变异发生,但拉米夫定联合其他抗病毒药物治疗能减少耐药株的产生并增强治疗效果,同时,不良反应少见。结论:拉米夫定治疗慢性乙型病毒性肝炎是安全和有效的。     

Immunomodulation as an option for the treatment of chronic hepatitis B virus infection: preclinical studies in the woodchuck model

New therapeutic approaches for chronic hepatitis B virus infection based on immunomodulation are now under investigation. The woodchuck model for hepatitis B virus infection has emerged as a useful animal model for the evaluation of such approaches, after developing necessary assays and reagents for immunologic studies in this model. Conventional and novel vaccines such as DNA vaccines were tested in woodchucks for their ability to induce protective immune responses against challenge infection with the woodchuck hepatitis virus (WHV). Furthermore, immunotherapeutic approaches for the control of chronic hepadnaviral infection were evaluated in woodchucks. Immunizations with WHV proteins and DNA vaccines led to the development of antibodies to the WHV surface antigen and to a significant decrease of viral load in chronically WHV-infected woodchucks. Viral vector-mediated gene transfer was explored for the delivery of antiviral cytokines IFN-alpha in woodchucks and resulted in the decrease of viral replication. It is now generally accepted that a combination of antiviral treatment and immunization will be necessary to achieve successful immunomodulation with a long-term control of chronic hepatitis B virus infection.     

Management of cytomegalovirus infection in patients with acquired immunodeficiency syndrome

The clinical manifestations of cytomegalovirus (CMV) infection in persons with AIDS are described, and recent advances in the management of these syndromes with antiviral agents are reviewed. CMV infection is the most common serious opportunistic viral infection in AIDS patients. Clinical manifestations include chorioretinitis, gastroenteritis, hepatitis, pneumonia, CNS infection, adrenalitis, and a wasting syndrome. The diagnosis of CMV infection requires laboratory demonstration of a serologic response to the virus, detection of viral components or products, or isolation of the virus. Ganciclovir is an acyclic nucleoside analogue marketed for the treatment of CMV-related retinitis in immunocompromised hosts. After i.v. ganciclovir induction therapy, more than 80% of patients show improvement or stabilization of retinitis. Relapse is common in AIDS patients, however, and low-dose i.v. maintenance therapy is recommended. The most serious dose-limiting effect is neutropenia. Intravitreal injection of ganciclovir has been well tolerated and efficacious. Ganciclovir has shown some efficacy in the treatment of other life-threatening CMV infections, especially gastroenteritis, but data are limited. Ganciclovir-resistant strains have been reported. Foscarnet, a pyrophosphate analogue with activity against both human CMV and human immunodeficiency virus, is undergoing clinical trials. Foscarnet has shown promise in the therapy of CMV-related retinitis, but results for other CMV infections are disappointing. Nephrotoxicity is the major dose-limiting effect. AIDS patients with sight-threatening and rapidly progressive CMV-related retinitis should be treated with ganciclovir. Foscarnet may offer an alternative when it becomes available. More must be learned about the efficacy of these drugs in the treatment of CMV infection in patients with AIDS.     

Main properties of duck hepatitis B virus DNA polymerase: comparison with the human and woodchuck hepatitis B virus DNA polymerases

The main properties of the duck hepatitis B virus (DHBV) DNA polymerase have been studied and compared with those of the human hepatitis B virus (HBV) and of the woodchuck hepatitis virus (WHV) DNA polymerases. All 3 enzymes are active under high salt conditions in the presence of high magnesium concentration. DHBV DNA polymerase was found less sensitive to ethanol and to operate at higher optimal pH than the HBV and WHV DNA polymerases. Like the other two viral endogenous DNA polymerases, the DHBV enzyme was strongly inhibited by phosphonoformic acid but not by aphidicolin, sulfhydryl group blockers or phosphonoacetic acid. Inhibition of DHBV DNA polymerase by the triphosphate derivatives of several nucleoside analogs appeared similar to that reported for HBV or WHV endogenous polymerase. FIACTP was the most, and ACVTP the least effective inhibitor; BVdUTP was of intermediary potency; araCTP and araTTP had a greater inhibitory effect on DHBV DNA polymerase than HBV or WHV DNA polymerase. The similarities in the properties of DHBV and HBV DNA polymerase justify the use of the duck hepatitis B polymerase model for screening and evaluation of potentially active drugs against HBV infection.     

AM3 inhibits HBV replication through activation of peripheral blood mononuclear cells

In this report, we have analyzed the effect of AM3, a glycoconjugate of natural origin with immunomodulatory properties, which is available under the commercial name of Inmunoferon, on hepatitis B virus (HBV) replication in HBV-transfected cells. We found that AM3 inhibited HBV RNA expression as well as DNA synthesis and viral antigen expression by an indirect mechanism. We found that AM3 lacked intrinsic antiviral properties, and that the antiviral effect of the glycoconjugate was due to stimulation of secretion of molecules with antiviral properties by peripheral blood mononuclear cells. Our data indicate that the employment of AM3 as an adjuvant administered simultaneously with conventional antiviral drugs may potentiate the endogenous response against viral infection.     

Adefovir dipivoxil added to ongoing lamivudine therapy in patients with lamivudine-resistant hepatitis B e antigen-negative chronic hepatitis B

BACKGROUND: Long-term treatment with lamivudine is required to control viral replication in patients with hepatitis B e antigen-negative chronic hepatitis B, but is associated with a high rate of viral resistance. The role of adefovir dipivoxil in these patients has not been definitively evaluated. AIM: To address the role of adefovir in the management of patients with lamivudine-resistant hepatitis B e antigen-negative chronic hepatitis B. METHODS: Patients were assigned to receive adefovir 10 mg once daily plus ongoing lamivudine 100 mg once daily for 52 weeks. The primary end point was reduction in serum hepatitis B virus DNA level (hepatitis B virus DNA response). Secondary end points included the proportion of patients with undetectable hepatitis B virus DNA at week 52 (complete virological response) and the percentage of patients with normalization of alanine transferase level at week 52 (biochemical response). RESULTS: A total of 49 consecutive patients were enrolled in this study. After 52 weeks of treatment, all patients had an hepatitis B virus DNA response and 57.1% had complete virological response. Biochemical response occurred in 75.6% of patients. CONCLUSIONS: Administration of adefovir in patients with lamivudine-resistant chronic hepatitis B results in significant suppression of viral replication. Nevertheless, continuous therapy will probably be needed in order to maintain remission in these patients.     

恩替卡韦抗乙型肝炎病毒感染量效关系及安全性的研究

目的:探讨恩替卡韦(ETV)治疗慢性乙型肝炎抗病毒感染的量效关系及安全性。方法:采用随机、双盲、安慰剂对照的临床试验,选择未经抗病毒治疗的慢性乙型肝炎病毒(HBV)感染者,按1:1:1的比例分为3组:ETV0.5mg/d组、ETV0.1mg/d组和安慰剂组,治疗28d,停药观察56d,然后用ETV0.5mg/d开放治疗48周,再次停药观察24周。结果:ETV0.5mg/d的疗效优于0.1mg/d,停药后HBV DNA的反跳也较缓慢。开放治疗期间有81.6%的受试者HBV DNA<0.7mmol/ml,HBeAg/抗HBe的血清转换率为7.9%,但停药后80%的受试者HBV DNA再度升高。给药组和安慰剂组受试者不良事件发生率无统计学差异(P=0.428),开放治疗期间未发现与恩替卡韦相关的严重不良反应。结论:ETV有较强的抗HBV活性,其抗病毒作用与剂量相关。恩替卡韦0.5mg/d治疗慢性乙型肝炎更为有效和安全。     

Zidovudine inhibits hepatitis B virus replication.

Hepatitis B virus DNA polymerase is a viral enzyme that can use viral DNA as well as viral RNA as a template for DNA synthesis. Since both activities are essential for the production of new virus particles, blocking of this enzyme should reduce viral replication. In the present study the in vitro effect of zidovudine triphosphate on hepatitis B virus DNA polymerase activity and the in vivo effect of zidovudine on viral replication in chronic HBsAg-positive patients are investigated. Zidovudine triphosphate inhibited in vitro DNA polymerase activity by 50% at a concentration of 0.3 microM. Serum DNA polymerase activity was significantly reduced in 7 patients who received zidovudine (200 mg orally 4 times daily) for one week. A dose-response effect was suggested by the results found for 6 patients who received 100 mg, 200 mg and 300 mg orally 4 times daily for one week with 2 drug-free weeks between each course. We conclude that zidovudine may be of value for non-responders to alpha-interferon therapy or patients with high initial levels of viral replication prior to the start of interferon treatment.