两种甲型肝炎病毒抗原快速检测方法的建立

目的建立两种甲型肝炎病毒抗原(HAV-Ag)检测试剂盒,并对其检测效果进行评价。方法生物素标记甲型肝炎病毒抗体(HAV-Ab)与辣根过氧化物酶标记亲和素联合应用建立甲型肝炎病毒抗原BA-ELISA检测法;同时使用辣根过氧化物酶标记HAV-Ab作放大系统建立双抗体夹心甲型肝炎病毒抗原ELISA检测试剂,对比两种检测方法的特异性、灵敏度及实际应用效果。结果用生物素标记甲型肝炎病毒抗体-辣根过氧化物酶标记亲和素作放大系统建立的甲型肝炎病毒抗原BA-ELISA检测法,较双抗体夹心ELISA检测方法灵敏度高1～2个稀释度;两种检测法均对10余种病毒无交叉,P/N值BA-ELISA检测法较高。结论甲型肝炎病毒抗原BA-ELISA检测法是一种灵敏度高,特异性好,方便快捷的检测方法,可广泛应用于甲型肝炎病毒研究及临床检测中。而甲型肝炎病毒抗原双抗体夹心ELISA检测法,检测灵敏度适中,操作简单,更适用于甲肝疫苗生产检定。     

Diamond-like carbon (DLC) microelectrode for electrochemical ELISA

A diamond-like carbon (DLC) microelectrode was applied to commercial ELISA kits for medical diagnosis of HIV (human immunodeficiency virus), HBV (human hepatitis B virus), HCV (human hepatitis C virus). In this work, quantification of oxidized 3,3',5,5'-tetramethylbenzidine (TMB) was carried out by using a microelectrode made of boron-doped DLC and cyclic voltammetric analysis method without the conventional quenching step which uses sulfuric acid. The microelectrode provided well-known step-shaped graphs, and limit of detection could be improved by clear determination of electrochemical oxidative and reductive peaks. To demonstrate the applicability of DLC microelectrode to conventional ELISA kits, commercial ELISA kits for detection of HIV antigen, HBV antigen and HCV antigen were also tested. These results proved that the applicability of DLC microelectrode to practical detection is feasible.     

Atomic force microscopy detection of serological markers of viral hepatites B and C

The possibility of detection of serological markers, containing the hepatitis B surface antigen (HBsAg) and hepatitis C virus core-antigen (HCVcoreAg) in human serum, by a new atomic force microscopy (AFM)-based nanotechnological approach has been demonstrated. The antibodies against the hepatitis B virus surface antigen (anti-HBsAg) and the antibodies against the hepatitis C virus core antigen (anti-HCVcoreAg) were immobilized on an AFM-chip. It was shown that such approach enables to detect HBsAg, HCVcoreAg and the viral fragments containing these antigens in the serum. The comparative analysis of detection of HBsAg- and HCVcoreAg-containing particles by the AFM method versus traditional methods (ELISA, PCR) has demonstrated the 75% coincidence of results between the AFM and two other methods.     

荧光定量PCR检测土拨鼠肝炎病毒核酸方法的建立

目的建立土拨鼠肝炎病毒（woodchuck hepatitis virus,WHV）核酸的荧光定量PCR（Real-time PCR）检测方法,应用于土拨鼠肝炎病毒模型的研究。方法分别根据土拨鼠肝炎病毒核心抗原（WHcAg）和表面抗原（WHsAg）的DNA序列设计13对扩增引物,从中筛选无非特异性扩增及引物二聚体且灵敏度高的引物,用于土拨鼠血清中WHV DNA的Real-time PCR检测。建立感染土拨鼠肝炎病毒的土拨鼠血清中WHV核酸的Real-timePCR检测方法。结果根据WHsAg基因的5＇端设计的一对引物WHVSF1与WHVSR1,检测灵敏度可达1×101拷贝/μL,病毒拷贝数与Real-time PCR Ct值的标准曲线的R2值为0.997,且电泳未见明显非特异性条带及引物二聚体。结论建立了土拨鼠血清中WHV DNA的Real-time PCR检测方法,该方法为进一步研究土拨鼠肝炎病毒模型奠定了基础。     

Suitability of yeast- and Escherichia coli-expressed hepatitis B virus core antigen derivatives for detection of anti-HBc antibodies in human sera

Antibody to hepatitis B virus core antigen (anti-HBc) is one of the most important serological markers during hepatitis B virus (HBV) infection. The quality of the hepatitis B virus core antigen (HBcAg; diagnostic antigen) is crucial to the accuracy of anti-HBc detection. In an attempt to explore the suitability of recombinant HBcAg (rHBcAg) for diagnostic purposes, HBcAg was expressed in Escherichia coli (E. coli) and Pichia pastoris (P. pastoris) and evaluated for the detection of anti-HBc. The expression level of the recombinant protein satisfied the criteria for large-scale biologic production. P. pastoris- and E. coli-derived rHBcAg were purified with gel filtration followed by sucrose gradient (reagents A and C) or with a monoclonal anti-HBc antibody binding (reagents B and D) and were utilized to detect anti-HBc in competitive inhibition enzyme-linked immunosorbent assay (ELISA) format. The ELISA using P. pastoris-derived rHBcAg had a higher specificity and sensitivity than that using E.coli-derived rHBcAg to detect the anti-HBc standard panel. Serum specimens were collected from HBV-infected patients and healthy individuals (voluntary blood donors). Anti-HBc was detected in those specimens using P. pastoris- and E. coli-derived rHBcAg. The positive rate of anti-HBc detection in HBV-infected patients' sera was 100% with reagents A and B, 96.4% with reagent C, and 93.6% with reagent D. The negative rate in healthy control sera was 100% with reagents A and B, 97.0% with reagent C, and 99.7% with reagent D. These data indicate that P. pastoris-derived rHBcAg is superior to E.coli-derived rHBcAg for the detection of anti-HBc using the diagnostic ELISA.     

Studies on the development of an ELISA kit for microbiological monitoring. 1. Evaluation of the reliability of the prototype kit by field tests

The prototype of an ELISA kit using protein A as the second reaction reagent for mice and anti-rat IgG for rats was prepared for seromonitoring of the Sendai virus and mouse hepatitis virus (MHV)/sialodacryoadenitis virus (SDAV)/Parker's rat coronavirus (PCV) infections. The respective antigen strains and protein concentrations were Sendai virus MN strain, 2 micrograms/ml and MHV Nu-67 strain, 5 micrograms/ml. The reliability of this prototype kit was investigated in two field tests performed on a total of 10,094 mouse and rat sera from 147 institutions. The results indicated that the two types of kits for the two species of animals were highly specific, but it is necessary to increase the detection sensitivity of the MHV antigen for the MHV antibody of mice and SDAV/PCV antibodies of rats.     

A hepatitis B surface antigen mutant that lacks the antigenic loop region can self-assemble and interact with the large hepatitis delta antigen

A novel hepatitis B virus surface antigen mutant harboring a deletion of most of the major antigenic loop region was competent for self-assembly and secretion. Although the mutant protein was competent for interaction with and incorporation of free large hepatitis delta antigen, it was partially defective in hepatitis delta virus RNP incorporation.     

Enhanced chemiluminescence ELISA for the detection of antibody to hepatitis B virus surface antigen

A chemiluminescent enzyme linked immunosorbent assay (ELISA) for the detection of antibody to hepatitis B virus surface antigen (anti-HBs) in human serum has been developed. Polystyrene microtitre plates were coated with recombinant, yeast-derived hepatitis B surface antigen (rec-HBsAg). Patient serum samples and appropriate controls were added to the rec-HBsAg-coated wells and incubated to bind anti-HBs. The wells were then washed and a fluorescein isothiocyanate (FITC) conjugate of a human plasma-derived hepatitis B surface antigen (HBsAg) was added. Following incubation and further washing the bound FITC-labelled HBsAg was detected after addition of a horseradish peroxidase (HRP) conjugate of a monoclonal anti-FITC antibody and assaying for the enzyme. The activity of the HRP was measured using luminol and hydrogen peroxide as substrates and iodophenol as a chemiluminescence enhancer. The luminescence was recorded using a camera luminometer. Preliminary tests have shown the assay to be suitable for the detection of antibody in sera from both vaccinees and also from individuals with a past hepatitis B virus infection. The use of the FITC-anti-FITC system together with the measurement of a chemiluminescence signal makes possible the completion of this assay in a few hours. The assay has been shown to be both specific and sensitive and provides a permanent photographic record.     

Effect of concurrent acute infection with hepatitis C virus on acute hepatitis B virus infection.

OBJECTIVE--To investigate the possible interference with acute hepatitis B virus infection by co-infection with hepatitis C virus. DESIGN--Analysis of stored sera collected for transfusion transmitted viruses study in 1970s. SETTING--Four major medical centres in the United States. PATIENTS--12 recipients of blood infected with hepatitis B virus. MAIN OUTCOME MEASURES--In 1970s, presence of antibodies in hepatitis B virus and raised serum alanine aminotransferase concentration; detection of antibodies to hepatitis C virus with new enzyme linked immunoassays. RESULTS--Five of the 12 patients were coinfected with hepatitis C virus. Hepatitis B surface antigen was first detected at day 59 in patients infected with hepatitis B virus alone and at day 97 in those coinfected with hepatitis C virus (p = 0.01); median durations of antigenaemia were 83 and 21 days respectively (p = 0.05), and the antigen concentration was lower in the coinfected patients. Alanine aminotransferase patterns were uniphasic when hepatitis B virus infection occurred alone (range 479-2465 IU/l) and biphasic in patients with combined acute infection (no value > 380 IU/l; p = 0.0025). Four coinfected recipients developed chronic hepatitis C virus infection. The fifth patient was followed for only four months. CONCLUSIONS--Acute coinfection with hepatitis C virus and hepatitis B virus inhibits hepatitis B virus infection in humans, and onset of hepatitis B may reduce the severity of hepatitis C virus infection but not frequency of chronicity. Alanine aminotransferase concentration showed a biphasic pattern in dual infection.     

Core antigen and antibody in woodchucks after infection with woodchuck hepatitis virus

The woodchuck hepatitis virus is a naturally occurring hepatitis B-like virus that infects the eastern woodchuck. Direct immunofluorescence staining for woodchuck hepatitis virus core antigen in liver biopsies demonstrated the presence of this antigen in 14 of 17 chronically infected woodchucks, and in 8 of 10 woodchucks undergoing acute infections. Fluorescent localization of woodchuck hepatitis virus core antigen was typically cytoplasmic, and this was confirmed further by electron microscopy. Experimental infection with woodchuck hepatitis virus was achieved in four of four woodchucks inoculated with serum from chronic carrier woodchucks. All infected animals developed a self-limited disease characterized by seroconversion to antibodies against the major viral antigens (core and surface antigens); naturally acquired acute infection demonstrated a similar course. A chimpanzee seronegative for all markers of hepatitis B virus developed a subclinical infection after inoculation with woodchuck hepatitis virus.     

Transient expression of hepatitis B virus surface antigen (HBsAg) gene in monkey cells by a SV40-based virus vector

Summary We have constructed a recombinant SV40-based vector carrying the S gene coding for the hepatitis B virus surface antigen (HBsAg). This vector replicates as an episome in monkey COS7 cells, producing high levels of hepatitis B virus surface antigen (HBsAg), which is liberated in the cell medium, probably as a membrane vesicule. The vector also carries the SV40-late genes and produces recombinant viruses. These viruses were used to infect fresh cell culture, with detection of HBsAg in the medium. Thus, this virus vector can efficiently transduce the gene for HBsAg.     

中缅树鼩自然感染六种病毒的血清流行病学

中缅树鼩作为一种新型实验动物,在医学生物学上,尤其是病毒学方面的应用受到越来越多的重视.实验动物自身病毒感染会影响动物健康和干扰实验结果,甚至危害实验人员生命安全.所以,实验动物病毒检测一直是动物质量控制的重要部分.中缅树鼩研究迄今缺乏清晰的病毒自然感染资料.为调查中缅树鼩的病毒感染状况,采集野生俘获和人工繁殖的中缅树鼩血清样本272份,全部血清样本通过ELISA方法对乙型肝炎病毒(HBV)表面抗原,丙型肝炎病毒(HCV)总抗体,以及戊型肝炎病毒(HEV)、腺病毒(ADV)、单纯疱疹病毒1型(HSV-1)和2型(HSV-2)的IgG抗体进行了检测.结果表明,ELISA初筛HBV表面抗原有3份阳性样本,但通过乙型肝炎两对半定量检测进一步确认为阴性:抗HCV抗体和抗HEV、ADV、HSV-1 IgO抗体检测均为阴性;抗HSV-2 IgG检测有1份阳性样本.提示仪抗原或抗体血清学指标检测树鼩肝炎结果并不能反应个体携带病毒的状态,应该再进行病毒学指标确认.同时建议中缅树嗣繁殖群应进行HSV-2的筛选,以便杜绝和控制该病毒的感染.     

The results of a controlled field trial of a dried erythrocytic immunoglobulin diagnostic agent for detecting the hepatitis A virus antigen]

The results of the controlled field trial of lyophilized erythrocytic immunoglobulin diagnosticum for the detection of hepatitis A virus antigen in the urine and feces of patients are presented. This diagnosticum was used for the study of urine and fecal samples from 225 patients (of these, 176 had hepatitis A) and 54 healthy persons in the passive hemagglutination (PHA) test. Their blood sera were studied in the PHA test (to detect HBsAg) and the radioimmunoassay (to detect anti-HAV IgM). The immunoglobulin diagnosticum under study was found to be nonspecific and faintly sensitive and, therefore, unsuitable for use in medical practice.     

Etiological structure of viral hepatitis in the area about one of the cities in Gorki Province

The etiological structure of viral hepatitides (VH) in one of the towns of the Gorky region was studied with the use of specific methods for diagnosing hepatitis A (detection of IgM to hepatitis A virus) and hepatitis B (detection of HBsAg in the passive hemagglutination test). The study revealed that hepatitis A was the major nosological from in the structure of VH among children and adults in the area under survey, which was documented by the detection of IgM to hepatitis A virus. The form, second in importance among VH cases, was hepatitis B. The ratio of these two forms of VH was determined by the epidemiological situation in the area. The proportion of hepatitis B cases increased at the period between epidemics. Nondifferentiated hepatitis constituted 6.8% of all cases of sporadic hepatitis among adults. In 90% of cases clinical diagnosis coincided with the serological one.     

Production of 22 nm HBsAG particles by human lymphocytes infected with a recombinant vaccinia virus containing the coding sequence for hepatitis B virus surface antigen.

To examine the possible role of lymphocytes in the course of hepatitis B virus infection, we studied peripheral blood lymphocytes and Epstein-Barr virus transformed B-cells for their capability to produce hepatitis B virus gene products. Infection of these cells with a recombinant vaccinia virus containing the hepatitis B virus surface antigen resulted in the production and secretion of hepatitis B virus surface antigen shortly after infection reaching a peak after three days. When the supernatants of the cells were analyzed on density gradients, a peak of reactivity for hepatitis B virus surface antigen was reached at 1.21 g/cm3. Electron microscopy revealed the presence of spherical and filamentous HBsAg particles. These findings show that human lymphocytes are capable of producing hepatitis B virus surface antigen.     

Hepatitis A and B: serologic survey of human and nonhuman primate sera

Sera of humans and seven species of nonhuman primates were tested by radioimmunoassay and enzyme immunoassay for the presence of hepatitis A antibody, hepatitis B surface antigen and antibody to hepatitis B surface antigen. The outcome of testing a total of 276 serum or plasma specimens was as follows: with the exception of squirrel monkeys (0%) and cotton-top marmosets (0%), a considerable percentage of all other species tested had detectable antibodies to hepatitis A virus: humans 45.9%, chimpanzees 36.6%, baboons 38.2%, vervets 57.9%, cebus monkeys 40.0% and common marmosets 50.0%. Only one human and two chimpanzees were carriers of hepatitis B surface antigen. Antibodies to hepatitis B surface antigen were detected in human (11.3%), chimpanzees (29.9%), baboons (36.2%) and squirrel monkeys (5%). Chimpanzees showed an increasing prevalence of antibodies to hepatitis A virus and hepatitis B surface antigen with age.     

A comparative analysis of the efficiency of bird and mammalian antibodies in HBsAg sandwich assay

The antigen-binding capacities of chicken and goat polyclonal antibodies and mouse monoclonal antibodies specific for the hepatitis B virus surface antigen were compared via enzyme immunoassay. It was shown that the use of both adsorbed and detecting chicken antibodies reduces significantly the analytical sensitivity of the sandwich method for the detection of this antigen. It was assumed that the reduced flexibility of IgY molecules hinders bivalent binding to antigen, which leads to the formation of more stable immune complexes.