摘要:

AbstractAt least five species of unspliced mRNA of the hepatitis B virus (HBV), which are 3.5, 3.4, 2.4, 2.1 and 0.8 kb, have been identified. To study this amount of HBV proteins they were translationally regulated and bothin vitroandin vivoexperiments performed. The fourin vitrosynthesized RNA corresponding to the 2.1, 2.4, 3.4, and 3.5 kb mRNA, respectively, were translated in a rabbit reticulocyte lysate. In conjunction within vivotransfection experiments, it was demonstrated that: (i) a preferential translational initiation is involved in the differential amount of surface antigens; (ii) the 2.1 kb mRNA is the template for the synthesis of the middle and major surface antigens in a ratio of about 1 : 4; (iii) the 2.4 kb mRNA, although containing sequences for coding the large, middle and major surface antigen, is primarily used for the synthesis of large surface antigens; (iv) both the core and pol proteins can be independently synthesized from the 3.4 kb mRNA (pregenome RNA) and the synthesis of pol protein is favourably carried out via a leaky scanning mechanism; (v) the 3.5 kb mRNA (pre‐C mRNA) is the template for the production of precore protein (the precursor of hepatitis B e antigen) but not for the synthesis of both core and pol proteins. Taken together, the results indicate that: (i) the translational initiation context of each HBV‐encoded protein plays a key role in determining the level of protein synthesis; (ii) the occurrence of bifunctional mRNA of pregenome RNA and 2.1 kb mRNA provides another alternative means for minimization of the viral genome size; (iii) the leaky scanning mechanism is involved in the expression of the second protein in bifunctional m

ISSN:0815-9319    

DOI:10.1111/j.1440-1746.1993.tb01681.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

AbstractThe pGEX plasmid containing the gene of glutathione S‐transferase (GST) was employed to express various lengths of the hepatitis B virus pol protein in a form of fusion protein inEscherichia coli.Results of SDS‐PAGE and Western blot analyses indicated that: (i) expression of GST‐pol fusion proteins varied from undetectable to 30% of total protein in different clones; (ii) presence of the carboxyl terminus of the pol protein apparently lowered the expression amount of fusion proteins; (iii) some distinct pol protein bands of lower molecular weight were constantly detected in several clones. The presence of the smaller pol protein therefore raises a possibility that the pol protein contains protease cutting

ISSN:0815-9319    

DOI:10.1111/j.1440-1746.1993.tb01683.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

AbstractHepatocytes, known as polarized epithelia, are composed of sinusoid, basolateral and bile canalicular domains. Using monoclonal antibody and human hepatoma cell lines, the canalicular domain was shown to be established in well‐differentiated lines via vesicle fusion, but not in poorly differentiated lines. To understand the metabolic processing of the bile canalicular antigen in different human hepatoma cell lines, monoclonal antibody C2D4 was produced by immunizing BALB/C mice with human hepatoms cell line HA22T/VGH and fusing sensitized mouse spleen cells with mouse myeloma cells. Using two‐dimensional polyacrylamide gel electrophoresis, the monoclonal antibody C2D4 was shown to react with the same molecule recognized by monoclonal antibody 9B2, which had been known to react with the antigen on the bile canalicular domain of human hepatocytes and hepatoma cells, bothin vivoandin vitro.Analysed with pulse‐chase radioimmunoprecipitation, C2D4 precipitated the 140 kD polypeptide through a 1–4 day well‐differentiated cell line, Hep G2; whereas in addition to the 140 kD polypeptide, an 80 kD protein was recognized by C2D4 in a 2 or 3 day poorly differentiated line, SK‐HEP‐1. Together with peptide mapping and subcellular fractionation analysis, the 80 kD protein was postulated to be internally degraded in the intracellular compartment, but not on the cytoplasmic membrane. It was concluded that the human hepatoma cell lines could be a goodin vitromodel to study the metabolic processing of bile canalicular domains of human hepatocytes. Also, the loss of the cellular polarity in poorly differentiated human hepatoma cell lines provides a good natural variant to study the differentiation and progression of human h

ISSN:0815-9319    

DOI:10.1111/j.1440-1746.1993.tb01684.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

AbstractThe nucleotide sequence of the 5′ untranslated region of hepatitis C viruses (HCV) has been shown to be conserved. In contrast, this study detected in the region of several HCV isolates more sequence variation than hitherto expected. The nucleotide sequences of the 5′ untranslated region of these isolates differ significantly from that of the prototype but are very similar to each other. This study considers these isolates as belonging to the same type of HCV. Among 240 HCV RNA polymerase chain reaction positive specimens that were examined, seven of them belong to this type. The results suggest that the HCV variants detected represent a different type of HCV and that they are responsible for approximately 3% of HCV infections in this part of the United Sta

ISSN:0815-9319    

DOI:10.1111/j.1440-1746.1993.tb01685.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

AbstractIn order to investigate the possibility that hepatitis C virus (HCV) can be classified into subgroups based on the variations in the envelope region, the nucleotide and deduced amino acid sequences were compared among the reported viral isolates including HCV1, HCJ1, HCJ4, HCVJ, HCVBK, HCVNK and HCJ6. From the homology analysis, the HCV isolates were classified into three subgroups: group I (HCV1 and HCJ1); group II (HCJ4, HCVJ, HCVBK and HCVNK); and group III (HCJ6). Furthermore, two novel regions were found in the E1 envelope region. One is located at aa246–258 (intersubtype variable region 1; ISVR‐1) where the amino acid sequences were relatively conserved within each subgroup, while the sequences were extremely different among the subgroups. Another is located at aa315–328 (intersubgroup common region‐1; ISCR‐1) where the amino acid sequences were completely identical among all seven HCV isolates despite the fact that the marked variations were distributed throughout the envelope region. The results suggest that the combination of ISVR‐1 and ISCR‐1 can be utilized as marker sequences for the classification of HCV strains and that the letter region might be one of the candidates fo

ISSN:0815-9319    

DOI:10.1111/j.1440-1746.1993.tb01686.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

AbstractPeripheral blood mononuclear cells (PBMC) from 46 hepatitis B virus (HBV) surface antigen (HBsAg)‐positive chronic active hepatitis (CAH) patients were examined for the presence and for the physical states of HBV DNA by Southern blot analysis. Twenty‐one of 46 patients (45.7%) were found to have HBV DNA in their PBMC. Further fractionation of PBMC of these patients indicated that HBV DNA can be found in both T and B lymphocytes but not in macrophages. Results also suggested that the PBMC‐associated HBV DNA was in a changing and unstable state. No HBV DNA could be detected in the long‐term culture of either Epstein‐Barr virus‐immortalized B cells or in interleukin‐2‐cultured T cells of

ISSN:0815-9319    

DOI:10.1111/j.1440-1746.1993.tb01687.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

AbstractIn order to prevent perinatal infection, the child of a hepatitis B e antigen‐positive mother was given hepatitis B immune globulin and vaccinated against hepatitis B virus (HBV) at birth. Despite circulating antibody to hepatitis B surface antigen (anti‐HBs), the child became infected and is a carrier. Recent serum samples show the co‐existence of hepatitis B surface antigen and anti‐HBs. This study tries to determine whether failure to neutralize this virus by anti‐HBs was associated with a change in the amino acid sequence of the surface protein of HBV. The polymerase chain reaction was used to amplify the region of the hepatitis B surface open reading frame encoding the major antigenic determinants from serum samples taken from the child at 2, 5 and 6 years of age. Nucleotide sequence analysis of the products revealed a point mutation which resulted in a substitution of arginine for glycine at amino acid position (145) in the second loop of theade

ISSN:0815-9319    

DOI:10.1111/j.1440-1746.1993.tb01688.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

AbstractIn order to explore multiple risk factors of hepatocellular carcinoma (HCC), a total of 13 737 male adult residents in 12 townships were studied for an average follow‐up period of 5.2 years. Sociodemographic characteristics, history of cigarette smoking and alcohol drinking, dietary habits, as well as personal and familial history of chronic liver diseases were obtained through standardized interviews based on structured questionnaires at the recruitment. Blood samples were also collected from 9688 (71%) study subjects and examined for the hepatitis B surface antigen (HBsAg). A total of 60 new HCC cases occurred giving an incidence rate of 83.3 per 100 000 person‐years. Cox's proportional hazards models were used to analyse multiple risk factors of HCC. In addition the HBsAg carrier status which showed a multivariate‐adjusted relative risk of 17.0, cumulative cigarette smoking, alcohol drinking quantity, vegetarian habit and low vegetable consumption were associated with the development of HCC. The multivariate‐adjusted relative risk was 1.8 for those who smoked 26 or more pack‐years of cigarettes compared with non‐smokers, 3.1 for those who drank alcohol 50 mL or more per day compared with those who were non‐drinkers or drank less than 50 mL per day, 2.5 for vegetarians compared with non‐vegetarians, as well as 4.6 and 2.6, respectively, for those who had a weekly vegetable consumption frequency of less than two meals and two to five meals compared with those who had a frequency of si

ISSN:0815-9319    

DOI:10.1111/j.1440-1746.1993.tb01689.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

AbstractA total of 461 patients at the Veterans General Hospital, Taipei who had received blood transfusions since March 1981 were followed prospectively with serum biochemistry tests and viral hepatitis markers before and after the blood transfusions, periodically for at least 6 months. Sixty‐three (13.7%) patients developed post‐transfusion hepatitis (PTH). Of the patients with PTH, 71.4% were found to have antibody to hepatitis C virus (anti‐HCV) seroconversion during the 1 year follow‐up period by the first‐generation of the hepatitis C virus (HCV) enzyme immunoassay (EIA) antibody test, but the second‐generation EIA detected an increase to 88.9%. All sera positive by the first‐generation EIA were also positive by the second‐generation EIA. Their mean incubation of serum alanine aminotransferase (ALT) elevation was 6.5 weeks. The mean interval between the day of blood transfusion and the onset of active anti‐HCV seroconversion was 18.3 weeks if tested by the first‐generation EIA, but shortened to 9.5 weeks if tested by the second‐generation EIA. Of 49 acute PTH C patients who were followed up for more than 1 year, 32 (65.3%) still had abnormal serum ALT levels. The results of this study demonstrate that acute hepatitis C is a frequent and important complication in blood transfusions in Taiwan. The second‐generation HCV antibody EIA derived from HCV genes encoding both capsid and non‐structural proteins is more sensitive for detection of HCV infection than recombinant c100‐3 assay derived from the non‐structural re

ISSN:0815-9319    

DOI:10.1111/j.1440-1746.1993.tb01690.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

AbstractTwenty patients with acute post‐transfusion hepatitis C were prospectively followed after blood transfusion. All had seroconversion of serum antibody to hepatitis C virus (anti‐HCV) or hepatitis C virus (HCV) RNA. They were randomly allocated to two groups. Ten patients received a subcutaneous injection of recombinant interferon (IFN) α‐2b, 3 million units (MU) thrice weekly for 3 months; this was generally 8 weeks after the first post‐transfusional elevation of serum alanine transaminase (ALT). Ten patients without specific treatment were selected as a control group. During the 3 month period, nine (90%, 95% CI = 54–99%) patients in the IFN‐treated group normalized serum ALT level, while only three (30%, 95% CI = 8–65%) in the control group normalized the serum ALT spontaneously (P<0.01). Two (25%) of eight patients who initially showed a complete response to IFN‐treatment had serum ALT elevated again. After a 6 month follow‐up, five (63%, 95% CI = 26–90%) of eight patients in the IFN‐treated group and four (44%, 95% CI = 15–77%) of nine patients in the control group normalized serum ALT (P= 0.40). Among the nine patients who normalized serum ALT during IFN treatment, eight had undetectable serum HCV RNA and one showed a decreased level. Two patients had detectable serum HCV RNA accompanied by elevated serum ALT again after completion of the IFN treatment. After 6 months follow‐up four (50%, 95% CI = 17–83%) of eight patients lost their serum HCV RNA in the IFN‐treated group and two (22%, 95% CI = 4–60%) of nine patients spontaneously lost their HCV RNA in the control group (P= 0.25). All patients tolerated the IFN treatment well but had minor side effects such as fever, rigor, malaise, leukopenia, myalgia, headache and hair loss. In conclusion, recombinant IFN α‐2b injections in patients with acute post‐transfusion hepatitis C can successfully suppress the viral RNA and lead to normalization of serum ALT. Whether this regimen can prevent the development o

ISSN:0815-9319    

DOI:10.1111/j.1440-1746.1993.tb01691.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY