摘要:

AbstractAn assay for the analysis of point mutations in DNA fragments amplified by the polymerase chain reaction is described. The method was applied to the analysis of mutations leading to single amino acid changes in the reverse transcriptase gene of human immunodeficiency virus type‐1 that are associated with decreased sensitivity of the virus to the effects of the nucleoside analogue zidovudine. The assay uses a mi‐crotitre format allowing large numbers of clinical samples to be analysed, and is a quantitative assay giving information on the relative proportions of wild‐type and mutant sequence at the point being analysed. The analysis of mutations in codons 67, 70, 215, and 219 of the RT gene in samples taken at various time points after the commencement of zidovudine therapy shows a high variability in the rate at which these mutations arise and in the proportions of wild‐type and mutant sequences observed. The method we describe has wide application to the analysis of other point mutations in clinical or research Studies. © 1992 Wiley

ISSN:0146-6615    

DOI:10.1002/jmv.1890370402

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1992

数据来源: WILEY

摘要:

AbstractHuman herpesvirus 6 (HHV‐6) prototype isolate GS is a newly identified lymphotropic herpesvirus and several subsequent herpes isolates were recognized as HHV‐6 by their hybridization to a HHV‐6(GS) DMA probe pZVH14. DNA restriction analysis and in vitro tropism studies show that HHV‐6 isolates can be divided into two groups, designated group A and group B. Antigenic relationships among 15 HHV‐6 isolates belonging to these two groups were examined using rabbit antibodies against HHV‐6(GS) infected cells, 11 monoclonal antibodies against three glycoproteins and four non‐glycoproteins of HHV‐6(GS), and sera from 136 healthy adults. More than 20 polypeptides from all these isolates were immu‐noprecipitated by rabbit polyclonal antibodies against HHV‐6(GS) infected cells. Reactivities of monoclonal antibodies segregated these isolates into the same two groups. Group A contains HHV‐6(GS), HHV‐6(U1102) from a Ugandan acquired immunodeficiency syndrome (AIDS) patient, and nine other HHV‐6 isolates from various disorders. HHV‐6(Z‐29) from a Zairian AIDS patient, HHV‐6(SF) isolated from the saliva of a human immunodeficiency virus (HlV)‐infected individual, HHV‐6(OK) from a child with exan‐them subitum, and HHV‐6(DC) from a leukopenia patient are in group B. Eighty‐one percent of the sera showed similar antibody titer in immunofluorescence assay with group A HHV‐6(GS) and group B HHV‐6(Z‐29) infected cells and 19% of the sera showed two‐ to four‐fold antibody titer differences. The mobilities of many of the polypeptides immunoprecipitated from group A HHV‐6(GS) and group B HHV‐6(Z‐29) infected cells were different and sera showed differences in the quantities and nature of polypeptides immunoprecipitated. Together, our data show that HHV‐6 related isolates segregate into two antigenically closely related yet distinct groups, exhibiting group common and group specific anti‐genie epitopes. The complex patterns of reactivities of human sera suggest that individuals may be

ISSN:0146-6615    

DOI:10.1002/jmv.1890370403

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1992

数据来源: WILEY

摘要:

AbstractPeripheral blood mononuclear cells (PBMC) from 25 patients with chronic hepatitis B were tested for the presence of free monomeric hepatitis B virus (HBV) DNA migrating as a single 3.2 Kb band by Southern blot analysis. The PBMC were cultured for 7 days in the presence of phytohemagglutinin (PHA) or concanavalin A (ConA) both of which yielded a proliferative response. By contrast, both bacterial lipopolysaccharide (LPS) and interleukin 2 (IL2) failed to do so. Dot blot assays were used to monitor HBV DNA level increase within PBMC. Following mitogen exposure HBV DNA levels increased above pre‐stimulation levels in 19/25 PHA cultures, 6/15 ConA cultures, 1/15 LPS cultures, and 1/15 IL2 cultures.In 15 patients, Southern blot analysis was carried out before and after PHA exposure. In 13/15 cases, a single 3.2 Kb band was observed in un‐stimulated cultures as well as in PHA cultures even though PHA induced a HBV DNA increase. One case exhibited bands migrating faster than the 3.2 Kb signal, compatible with replicating intermediates and one case provided evidence of viral concatemers within PBMC after PHA stimulation. No HBV DNA was detected in the culture supernatants. The increase of HBV DNA level in PBMC induced by mitogen was strongly associated with an increase in HBV DNA expression (HBV RNA and HBs antigen). These studies indicate that HBV DNA present in human PBMC does represent a potential reservoir for infection with endogenous reactivation following PBMC activation. © 1992 Wiley‐Lis

ISSN:0146-6615    

DOI:10.1002/jmv.1890370404

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1992

数据来源: WILEY

摘要:

AbstractWe studied epidemics of viral hepatitis occurring at three different places in India. One was a combined epidemic due to hepatitis E virus (HEV) and hepatitis A virus (HAV) infections. In this epidemic, HAV affected children below 10 years of age, whereas HEV infected the young adult population. HEV was transmitted to rhesus monkeys (Macaca mulata) and confirmed by the polymerase chain reaction (PCR) on bile from the animals. Fecal material from acutely infected patients in one of the epidemics was also found positive for HEV RNA by PCR. This may help in confirming the nature of future epidemics. The bile and liver from experimental animals can be used as a source of material for further virological and molecular biological studies of HEV. © 1992 Wiley‐Liss, I

ISSN:0146-6615    

DOI:10.1002/jmv.1890370405

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1992

数据来源: WILEY

摘要:

AbstractThe expression of transforming growth factor a (TGF‐α) was examined in a human hepatoblastoma cell line. Hep G2, which does not contain hepatitis B virus (HBV) DNA, and in the cell line 2.2.15, which was formed by the transfection of Hep G2 cells with the complete HBV DNA, to study the possibility that HBV and TGF‐α could function as co‐factors in hepatocarcinogenesis. Northern blot hybridization of RNA extracted from these cell lines, with densitometric analysis, revealed expression of the TGF‐α gene in the transfected cells at a level three times higher than in the nontransfected cells. Staining of the cells using a monoclonal antibody to TGF‐α and the avidin‐biotin‐peroxidase immunohistochemical method revealed a much higher intensity of TGF‐α staining in the transfected cell line. These findings show that the presence of HBV DNA appears to cause a significant up‐regulation of the TGF‐α gene. This effect on the TGF‐α gene may be a mechanism by which HBV contributes to the etiology of hepatocellular carcinoma in some pati

ISSN:0146-6615    

DOI:10.1002/jmv.1890370406

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1992

数据来源: WILEY

摘要:

AbstractSeventy‐three pediatric patients with acute hepatitis and 19 control patients without liver disease living in Cairo, Egypt, were evaluated with a newly developed Western blot assay for IgM antibody to hepatitis E virus (IgM anti‐HEV). The mean age of acute hepatitis patients was 6.4 years (range, 1‐13 years); 56% were male. Among the 73 acute cases, hepatitis A was diagnosed in 30 (41%), possible acute hepatitis B in three (4%), hepatitis E in nine (12%), and by exclusion, non‐A, non‐B hepatitis in 29 (40%). Two additional acute cases were positive for both IgM anti‐HAV and IgM anti‐HEV. None of the 19 control subjects had IgM anti‐HEV. Parenteral risk factors were associated with cases of non‐A, non‐B hepatitis but were not associated with acute hepatitis E. Contact with a family member with jaundice was associated with acute hepatitis A. In contrast to prior epidemics of enterically‐transmitted non‐A, non‐B hepatitis, HEV was found to be a common cause of acute hepatitis in a pediatric population. This study provides additional evidence that HEV may be a frequent cause of acute sporadic hepatitis among children living in some developing countrie

ISSN:0146-6615    

DOI:10.1002/jmv.1890370407

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1992

数据来源: WILEY

摘要:

AbstractSince the amount of hepatitis C virus (HCV) RNA might be correlated with the degree of severity of hepatitis and response to treatment, quantitation of HCV RNA in serum was established using competitive polymerase chain reaction (PCR). Known amounts of a plasmid containing HCV‐cDNA were co‐amplified with a standard dilution series of a competitive template which shared the primers' sequences but differed from the wild type cDNA in having a deletion. Accurate quantitation was obtained by comparing the amount of both products. Quantitation of serum HCV RNA was carried out in two patients' serum samples which were also used to infect chimpanzees. The concentration of HCV RNA in these two sera was calculated to be 1 pg/ml (non‐infectious at 10−3dilution) and 1–10 pg/ml (infectious at 10−5dilution). The procedure was subsequently used to analyze serial changes in serum HCV RNA in three patients who were treated with a‐interferon. During treatment, the levels of ala‐nine aminotransferase showed a significant decrease in all patients and the amount of HCV RNA fell from 1 fg/ml, 1 pg/ml, and>10 pg/ml to 0.1 fg/ml, 100 fg/ml, and 1 pg/ml, respectively. The decrease in the amount of HCV RNA after treatment was related to the initial amount of serum HCV RNA. These results suggest that quantitation of HCV RNA may be useful not only for understanding the course of HCV infection but also for evaluating treatment for HCV infection. © 1992

ISSN:0146-6615    

DOI:10.1002/jmv.1890370408

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1992

数据来源: WILEY

摘要:

AbstractAn enzyme‐linked immunosorbent assay (ELISA) was developed for the quantification of serum antibodies against group‐specific epitopes of the glycoproteins (G1, G2) and nucleoprotein (NP) of the genus Hantavirus. This assay was used to study the kinetics of the development of serum antibodies after natural infection with Puumala‐like virus in humans. To this end a panel of 34 serum samples collected from individuals at different times after natural infection was tested by the ELISA. The samples were also tested for specific IgM and IgG levels against Puumala‐like virus, which provided confirmatory data about the presumed timing of infection. It was shown that serum antibodies against the G1 epitope were present in the acute and early convalescent period just before antibodies to the NP epitope could be demonstrated. In contrast, antibodies to two G2 epitopes were present not earlier than in the convalescent and late convalescent period. Since all these categories of antibodies seem to persist for long periods, antibodies against the G1 epitope and the NP epitope may be of specific diagnostic value. Furthermore, levels of G1‐specific antibodies and antibodies to either NP or G2 may allow estimation of the time elapsed following initial infection. © 1992 Wiley

ISSN:0146-6615    

DOI:10.1002/jmv.1890370409

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1992

数据来源: WILEY

摘要:

AbstractOf sera from 1,878 Japanese blood donors who carried hepatitis B surface antigen (HBsAg), 420 were subtyped asadw(22.4%) and 1,443 asadr(76.8%); only 15 (0.8%) contained HBsAg of subtypeayworayr. Sera with HBsAg/adrhad higher HBsAg titres than those with HBsAg/adw (geometric mean of haemagglutination titre: 10.1 ± 2.4 vs. 9.7 ± 2.4,p<0.01), and a higher prevalence of hepatitis B e antigen (24% vs. 13%,p<0.001). Carriers of HBsAg/awr progressively predominated over those of HBsAg/adwwith increasing age. Of sera from 1,863 carriers of HBsAg/adwor HBsAg/adr, 182 (9.8%) contained HBsAg particles with both subtypic determinants in thewir allele. The presence of wandrdeterminants on the same particles was ascertained by sandwiching them between monoclonal antibody with the specificity for w and that with the specificity for r. HBsAg particles of compound subtype(adwr)were found more often in sera with hepatitis B e antigen than those without it (145/403 [36.0%] vs. 37/1,460 [2.5%],p<0.001). Sera with HBsAg/adwrparticles had HBsAg titres higher than those without them (12.4 ± 1.9 vs. 9.7 ± 2.3,p<0.001). HBsAg/adwrparticles arise from phenotypic mixing of the S‐gene product of wild‐type virus and that of mutants with point mutations for subtypic changes. The results obtained indicated that HBV strains of subtypeadrhave a higher replicative activity than those ofadw, and suggested that mutations in the S gene for subtypic changes would be associated with an active replication of hepatitis B virus. © 1992 Wiley

ISSN:0146-6615    

DOI:10.1002/jmv.1890370410

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1992

数据来源: WILEY

摘要:

AbstractSince hepatitis C virus (HCV) and hepatitis delta virus (HDV) are transmitted by the same routes as hepatitis B virus (HBV), simultaneous or concurrent HCV and HDV infection in patients with chronic HBV infection may occur. To test this hypothesis and to examine the clinicohistological and immunopathological presentations of such multiple hepatitis virus infections, acute and/or convalescent serum specimens from 86 patients with acute HDV superinfection were tested by enzyme immunoassay for antibodies to HCV. Of the 86 patients, 18 (20.9%) were associated with HCV infection. Although patients with early mortality cannot be evaluated by the HCV markers used in this study, the results showed that the clinical and histologic features were similar except that patients with HCV infection were older than those without HCV infection (P<0.01). Immunopathological studies carried out within 2 months after the onset of acute HDV superinfection demonstrated that hepatitis B core antigen (HBcAg) was not detected in any patient and HDV antigen was detected in 18.2% of the patients with HCV infection whereas HBcAg and HDAg were found in 7% and 65.1%, respectively, of those without HCV coinfection (P<0.02). It is concluded that concurrent HCV and HDV superinfections can and do occur in patients with chronic HBV infection. In these triple viral infections, HCV may even transiently suppress HDV and HBV. © 1992 Wiley‐Liss, I

ISSN:0146-6615    

DOI:10.1002/jmv.1890370411

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1992

数据来源: WILEY