The outcome of acute hepatitis C predicted by the evolution of the viral quasispecies

The mechanisms by which hepatitis C virus (HCV) induces chronic infection in the vast majority of infected individuals are unknown. Sequences within the HCV E1 and E2 envelope genes were analyzed during the acute phase of hepatitis C in 12 patients with different clinical outcomes. Acute resolving hepatitis was associated with relative evolutionary stasis of the heterogeneous viral population (quasispecies), whereas progressing hepatitis correlated with genetic evolution of HCV. Consistent with the hypothesis of selective pressure by the host immune system, the sequence changes occurred almost exclusively within the hypervariable region 1 of the E2 gene and were temporally correlated with antibody seroconversion. These data indicate that the evolutionary dynamics of the HCV quasispecies during the acute phase of hepatitis C predict whether the infection will resolve or become chronic.     

Seroprevalence and epidemiological correlates of HTLV-I infection in U.S. blood donors

Screening for human T-lymphotropic virus type I (HTLV-I) antibodies was performed on sera from 39,898 blood donors at eight blood centers in geographically distinct areas of the United States. Ten donors (0.025 percent) showed evidence of HTLV-I seropositivity by enzyme immunoassays; this was confirmed by protein immunoblot and radioimmunoprecipitation. Seroprevalence rates ranged from 0 to 0.10 percent at the locations sampled, with HTLV-I antibodies found predominantly in donors from the southeastern and southwestern United States. Matched case-control interviews and laboratory studies were performed on five seropositive women and two seropositive men who participated in an identity-linked collection of sera from a subset of 33,893 donors at six of the eight blood centers. Four of the women and both men are black; one woman is Caucasian. Four of the seven seropositive individuals admitted to prior intravenous drug abuse or sexual contact with an intravenous drug user. Sexual contact with native inhabitants of an HTLV-I endemic area was the only identified risk factor for one male. The distribution of HTLV-I antibodies in this U.S. blood donor sample corroborates the previously reported epidemiology of this agent and suggests that additional donor screening measures, including the testing of donated blood for HTLV-I markers, may be necessary to prevent the spread of HTLV-I to transfusion recipients.     

人、猪和鸡血清中抗禽戊型肝炎病毒抗体的检测与鉴定

通过对人、猪和鸡血清中的抗禽戊型肝炎病毒(hepatitis E virus, HEV)ORF2抗体的检测以及对阳性血清抗体特异性的鉴定,本研究结果表明,人、猪和禽血清中抗禽HEV ORF2抗体阳性率为0.91%～62.5%.因为禽与哺乳动物HEV ORF2抗原具有共有的抗原表位,而阳性血清中抗禽HEV ORF2特异性抗原表位抗体的阳性率为41.3%～92.1%,提示人、猪和鸡都有感染禽HEV的可能性,这为进一步验证禽HEV可能造成的人兽共感染提供新的科学依据.     

胶体金免疫层析法检测猪瘟(强弱毒区分)抗体研究

以原核表达的重组猪瘟病毒E2蛋白为弱毒抗原,以猪瘟病毒(HCV)强毒株细胞培养物为强毒抗原,利用胶体金标记技术国内首次建立了HCV抗体检测(强弱毒区分)的免疫层析试纸条(双抗原夹心法)。研究结果表明,检测时只需将80μL待检测猪血清加于加样端20 min后观察结果即可。若观察区上端仅1条红色条带,即为HCV抗体阴性;2~3条条带即为HCV抗体阳性;若出现2条条带的位置为观察区上端和中间部位,即为HCV弱毒抗体阳性;若出现2条条带的位置位于观察区上端和下端部位,则为HCV强毒抗体阳性;若出现3条条带则HCV强弱毒抗体均为阳性。本试纸可很好地避免因试验操作造成的假阳性、假阴性,且操作简单、快速、简便、灵敏度高、特异好、不需特殊设备、价格低廉,20 min即可判断结果,且可区分强弱毒感染,适于基层实验室和现场检测。     

庚型病毒性肝炎22例临床观察(附7例病理报告)

目的：观察庚型肝炎（ Ｈ Ｇ）临床、生化和病理特点。方法：用逆转录聚合酶链反应（ Ｒ Ｔ Ｐ Ｃ Ｒ）检测血清 Ｈ Ｇ Ｖ Ｒ Ｎ Ａ,并对２２ 例 Ｈ Ｇ的临床表现、肝功能检查和７ 例肝组织的病理特征进行分析。结果：（１） Ｈ Ｇ 的传播以输血及血制品和注射途径为主;（２）７ 例单纯 Ｈ Ｇ 的临床表现有一定隐匿性,血清丙氨酸转氨酶（ Ａ Ｌ Ｔ）、总胆红素（ Ｔｂｉｌ）、白蛋白（ Ａ）、 Ａ／ Ｇ、和凝血酶原活动度（ Ｐ Ｔ Ａ）的异常程度均明显轻于 Ｈ Ｇ重叠慢丙肝（９ 例）或慢乙肝者（６ 例）（ Ｐ＜ ０．０５）;（３）肝组织学示３ 例单纯 Ｈ Ｇ者呈急性轻型肝炎改变,而４ 例 Ｈ Ｇ 合并慢丙肝或慢乙肝者的肝组织则呈现不同程度的炎症活动和肝纤维化。结论：单纯 Ｈ Ｇ Ｖ 感染的临床症状和肝损害均较轻、预后良好,而 Ｈ Ｇ重叠慢性乙肝或慢性丙肝者则肝功能损害可较明显。     

流式细胞术检测TcR Vα24/Vβ11双阳性NKT细胞及其在HCV感染者中的应用

目的研究丙肝病毒感染者外周血NKT细胞含量与HCV感染状态之间的相关性.方法应用流式细胞术检测TcR Vα24/Vβ11双阳性NKT细胞.结果抗-HCV阳性且HCVRNA也阳性的病例NKT细胞数量明显低于抗-HCV阳性而HCV RNA阴性的病例（P〈0.01）,明显低于正常对照组（P〈0.05）.结论由于NKT细胞数量减少或活化受阻,造成HCV的持续感染,不利于病毒的清除;另一方面,由于肝内有HCV的存在,NKT细胞大量向肝内趋化,导致外周血的数量相对减少.     

Complete replication of hepatitis C virus in cell culture

Many aspects of the hepatitis C virus (HCV) life cycle have not been reproduced in cell culture, which has slowed research progress on this important human pathogen. Here, we describe a full-length HCV genome that replicates and produces virus particles that are infectious in cell culture (HCVcc). Replication of HCVcc was robust, producing nearly 10(5) infectious units per milliliter within 48 hours. Virus particles were filterable and neutralized with a monoclonal antibody against the viral glycoprotein E2. Viral entry was dependent on cellular expression of a putative HCV receptor, CD81. HCVcc replication was inhibited by interferon-alpha and by several HCV-specific antiviral compounds, suggesting that this in vitro system will aid in the search for improved antivirals.     

Isolation of a cDNA clone derived from a blood-borne non-A, non-B viral hepatitis genome

A random-primed complementary DNA library was constructed from plasma containing the uncharacterized non-A, non-B hepatitis (NANBH) agent and screened with serum from a patient diagnosed with NANBH. A complementary DNA clone was isolated that was shown to encode an antigen associated specifically with NANBH infections. This clone is not derived from host DNA but from an RNA molecule present in NANBH infections that consists of at least 10,000 nucleotides and that is positive-stranded with respect to the encoded NANBH antigen. These data indicate that this clone is derived from the genome of the NANBH agent and are consistent with the agent being similar to the togaviridae or flaviviridae. This molecular approach should be of great value in the isolation and characterization of other unidentified infectious agents.     

Anti-idiotypic antibody vaccine for type B viral hepatitis in chimpanzees

Anti-idiotypic antibodies (anti-Id) that contain an internal image component that mimics the surface antigen of hepatitis B virus (HBsAg) were used to immunize chimpanzees. Four injections of the rabbit anti-Id preparation elicited an antibody response to HBsAg (anti-HBs). The antibody specificity appeared to be against the anti-Id, since the anti-Id immunogen was shown to bind the chimpanzee anti-HBs. Two chimpanzees immunized with the anti-Id, along with two control animals that were either untreated or received a nonimmune rabbit immunoglobulin G preparation, were challenged with infectious hepatitis B virus. Both control chimpanzees developed clinical and serological characteristics consistent with an active hepatitis B virus infection, whereas the two anti-Id treated chimpanzees were protected from infection. Since chimpanzees provide a relevant model of a human response to hepatitis B virus immunization and infection, these results indicate that anti-Id preparations such as that described here might be candidates for vaccines against human diseases.     

广西猪戊型肝炎血清流行病学调查

为了解广西各地猪群戊型肝炎（HE）的感染状况及其流行特点,采用双抗原夹心ELISA检测来自广西11个市34个猪场及南宁市某屠宰场猪血清中的抗HEV抗体,并比较分析不同地区、不同年龄段猪抗HEV抗体阳性率的差异。结果表明,所检测的34个猪场均为抗HEV抗体阳性猪场;537份血清中有448份呈阳性,阳性率为83．4％;其中2月龄以内、3-4月龄和5月龄以上猪的抗体阳性率分别为74．0％、47．0％和95．5％,差异显著（P〈0．05）;广西各地区猪群抗HEV抗体阳性率均在70．0％以上,差异不显著（P〉0．05）。可见,广西猪群普遍存在HEV感染,且母源抗体消失后,猪群抗HEV抗体阳性率随着年龄增长而升高。     

Amino acid homology between the encephalitogenic site of myelin basic protein and virus: mechanism for autoimmunity

Amino acid sequence homology was found between viral and host encephalitogenic protein. Immune responses were then generated in rabbits by using the viral peptide that cross-reacts with the self protein. Mononuclear cell infiltration was observed in the central nervous systems of animals immunized with the viral peptide. Myelin basic protein (MBP) is a host protein whose encephalitogenic site of ten amino acids induces experimental allergic encephalomyelitis. By computer analysis, hepatitis B virus polymerase (HBVP) was found to share six consecutive amino acids with the encephalitogenic site of rabbit MBP. Rabbits given injections of a selected eight- or ten-amino acid peptide from HBVP made antibody that reacted with the predetermined sequences of HBVP and also with native MBP. Peripheral blood mononuclear cells from the immunized rabbits proliferated when incubated with either MBP or HBVP. Central nervous system tissue taken from these rabbits had a histologic picture reminiscent of experimental allergic encephalomyelitis. Thus, viral infection may trigger the production of antibodies and mononuclear cells that cross-react with self proteins by a mechanism termed molecular mimicry. Tissue injury from the resultant autoallergic event can take place in the absence of the infectious virus that initiated the immune response.     

Natural variation of canine parvovirus

Canine parvovirus was first recognized during 1978. Analysis of isolates collected since its emergence revealed that viruses circulating after 1980 were antigenically different from earlier isolates. Monoclonal antibodies clearly distinguished the two strains, some being specific for either the old or the new viruses. Restriction enzyme analysis of viral DNA's showed that the post-1980 viruses were similar to earlier isolates, but some restriction site differences were present in the new strain. These results suggest that the canine parvoviruses infecting dogs in the seven areas of the United States that were sampled derive from a variant virus that replaced the original strain during 1980.     

乙型肝炎与戊型肝炎病毒重叠感染者血清HBV标记物结果分析

目的：观察乙型肝炎病毒（ＨＢＶ）与戊型肝炎病毒（ＨＥＶ）重叠感染对ＨＢＶ复制的影响。方法：以血清ＨＢｓＡｇ和抗ＨＥＶ均阳性患者３６例作为重叠组,以单纯ＨＢＶ感染患者３６例作为对照组。两组病例抗ＨＡＶ－ＩｇＭ和抗ＨＣＶ均为阴性。采用ＥＬＩＳＡ法测定两组的ＨＢＶ－Ｍ。结果：重叠组血清ＨＢｅＡｇ的阳性率明显低于对照组（Ｐ＜０．００１）,抗ＨＢｅ阳性率明显高于对照组（Ｐ＜０．０５）。结论：ＨＢＶ与ＨＥＶ重叠感染后,ＨＢＶ的复制受到一定程度的抑制     

Antibodies to hepatitis B surface antigen potentiate the response of human T lymphocyte clones to the same antigen

Human t-helper lymphocyte clones specific for hepatitis B virus surface antigen (HBsAg) proliferate on stimulation with HBsAg in vitro. Antibodies specific for HBsAg, but no other antibodies, augment this proliferative response. In the presence of antibodies to HBsAg, the maximum response could be achieved at HBsAg concentrations that were 1 percent of those required in the absence of the antibodies. These findings suggest that antigen-specific antibodies exert regulatory controls on T cells that recognize the same antigens.     

Autologous red cell agglutination assay for HIV-1 antibodies: simplified test with whole blood

An antibody detection procedure based on agglutination of autologous red cells has been developed for samples of whole blood. A nonagglutinating monoclonal antibody to human red blood cells conjugated to a synthetic peptide antigen (in this case residues 579 to 601 of the HIV-1 envelope precursor, Arg-Ile-Leu-Ala-Val-Glu-Arg-Tyr-Leu-Lys-Asp-Gln-Gln-Leu-Leu-Gly-Ile-Trp- Gly-Cys - Ser-Gly-Lys) permitted the detection of antibodies to the human immunodeficiency virus type 1 (HIV-1) in 10 microliters of whole blood within 2 minutes. Agglutination was specifically inhibited by addition of synthetic peptide antigen but not by unrelated peptides. The frequency of false positive results was 0.1% with HIV-1 seronegative blood donors (n = 874). The false negative results were approximately 1% (n = 81). The autologous red cell agglutination test is potentially suitable for simple, rapid, qualitative screening for antibodies to a variety of antigens of medical and veterinary diagnostic significance.     

Synergism between HIV gp120 and gp120-specific antibody in blocking human T cell activation

The human immunodeficiency virus (HIV) binds to CD4-positive cells through interaction of its envelope glycoprotein (gp120) with the CD4 molecule. CD4 is a prominent immunoregulatory molecule, and chronic exposure to antibody against CD4 (anti-CD4) has been shown to cause immunodeficiency in mice. T cell-dependent in vitro immune responses can also be inhibited by anti-CD4. Experimental findings reported here indicate that CD4-bound gp120 attracts gp120-specific antibodies derived from the blood of HIV-seropositive individuals to form a trimolecular complex with itself and CD4. Thus targeted to CD4, the gp120-specific antibody functions as an antibody to CD4; it cross-links and modulates the CD4 molecules and suppresses the activation of T cells as measured by mobilization of intracellular calcium (Ca2i+). The synergism between gp120 and anti-gp120 in blocking T cell activation occurs at low concentrations of both components. Neither gp120 nor anti-gp120 inhibits T cell activation by itself in the concentrations tested.     

Serologic evidence of chlamydial and mycoplasmal pharyngitis in adults

In a study of 763 adult patients we found serologic evidence of infection (a fourfold increase in antibodies) with Chlamydia trachomatis in 20.5 percent of the patients and with Mycoplasma pneumoniae in 10.6 percent, but with group A streptococcus (by culture) in only 9.1 percent. Pharyngitis, the most common problem for which patients seek medical care in the United States, may be caused by nonviral, potentially treatable organisms more often than had been suspected.     

不同免疫程序对MDV抗独特型抗体苗效果的影响

探讨不同免疫程序对MDV（Marek＇s DiseaseVirus,MDV）抗独特型抗体苗抗感染保护的影响.将MDV抗独特型抗体苗用胚内.皮下与单纯皮下相结合的方法免疫SPF鸡,以第二次免疫接种5 d攻毒后, 进行抗感染保护测定,比较各实验组淋巴细胞增生病变,病毒分离及大肠杆菌感染指标等的差异,确定MDV抗独特型抗体苗的免疫程序.结果表明,二种免疫效果相同,抗MD感染保护力达90%.     

Development of a cELISA for effective detection of the antibody against H7 subtype of avian influenza virus

H7 avian influenza viruses(AIVs) normally circulated among birds before. From 1996 to 2012, human infections with H7 AIVs(H7 N2, H7 N3, and H7 N7) were reported in Canada, Italy, Mexico, the Netherlands, the United Kingdom and the USA. Until March 2013, human infections with H7 N9 AIVs were reported in China. Since then, H7 N9 AIVs have continued to circulate in both humans and birds. Therefore, the detection of antibodies against the H7 subtype of AIVs has become an important topic. In this stu...     

慢性乙型肝炎患者血清e抗原抗体系统与病情和预后关系的探讨

本文分析了114例慢性乙型肝炎(CHB)患者血清e抗原抗体系统与病情和预后的关系。结果表明,HBeAg阳性者大多数表现为慢性迁延性肝炎(CPH),而HBeAg(-)抗HBe(+)者较多表现为慢性活动性肝炎(CAH)、肝硬化、慢重肝或肝癌。抗-HBe(+)者的病情和预后较HBeAg(+)者严重(P<0.001)。抗-HBe(+)者可能为乙型肝炎病毒(HBV)前C区突变株感染所致。分析CHB患者血清e抗原抗体系统以及其它HBV标记物的特点,对估计其所感染的HBV类型、肝病轻重和预后好坏,可能具有重要的临床意义。