摘要:

AbstractIn an attempt to interrupt perinatal and postnatal transmission of hepatitis B virus (HBV) infection, hepatitis B vaccine trials were initiated in October 1981 in Taiwan, starting in neonates of hepatitis B e antigen (HBeAg)‐positive hepatitis B surface antigen (HBsAg) carrier mothers and extending to neonates of non‐carrier mothers. All neonates had received a four‐dose schedule of Pasteur plasma‐derived hepatitis B vaccine. Among neonates of HBeAg‐positive HBsAg carrier mothers, the protective efficacy rate of vaccination was 75% in those who received vaccine alone and 90% in those who received vaccine plus hepatitis B immunoglobulin (HBIG) at birth. Among neonates of HBeAg‐negative HBsAg carrier mothers, the protective efficacy rate was 100% whether they had received vaccine alone or vaccine plus HBIG at birth. The protective efficacy rate was also 100% in neonates of non‐carrier mothers. During 6–9 years of long‐term follow‐up, 12 (6%) responsive vaccinees of HBeAg‐positive carrier mothers, one (2%) child of HBeAg‐negative carrier mothers and one child (0.4%) of non‐carrier mothers had seroconverted to antibody to hepatitis B core antigen (anti‐HBc) positivity. ‘Natural booster’ phenomenon, defined as a spontaneous sharp rise in serum antibody to HBsAg (anti‐HBs) titres in the absence of anti‐HBc and HBsAg, was observed in 7% of vaccinees whose mothers were HBeAg‐positive, 6% of vaccinees whose mothers were HBeAg‐negative HBV carriers, and 8% in vaccinees of non‐HBV carrier mothers. None of the responsive vaccinees had seroconverted to HBsAg. Thus, in the first decade of life, the protective efficacy in neonates who responded to pl

ISSN:0815-9319    

DOI:10.1111/j.1440-1746.1993.tb01692.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

AbstractThe hepatitis C virus (HCV) core antibody and NS‐4 antibody were measured in 25 cases of type C chronic hepatitis after interferon (IFN) treatment. The antibody titres were quantitated and the changes in the antibody titres and the therapeutic effects were compared. The titres of the passive haemagglutination assay (HCV‐PHA) before and after IFN administration were also measured and compared with the therapeutic effects. No significant correlation was seen between the core, NS‐4 and HCV‐PHA titres before IFN administration and the resultant therapeutic effects, but many cases showing excellent effects were seen among those with core antibody titres under 100 U/L and those with HCV‐PHA titres less than 2.16In a study of the changes in the core and NS‐4 antibody titres, these titres tended to decrease during IFN administration. In cases showing excellent effects, these decreases continued for a long period after completion of IFN administration and then became negative in some cases. However, in the remaining cases, titres showed increases up to 3 months after completion of IFN administration. HCV‐PHA showed reduced titres in many cases of excellent effects before and after IFN administration; and there were also cases showing decreases with two powe

ISSN:0815-9319    

DOI:10.1111/j.1440-1746.1993.tb01667.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

AbstractIn order to understand the cycle and disease process of hepatitis B virus (HBV) at the molecular level, the regulation of viral gene expression was studied. This paper reports the characterization of HBV core promoter: two 3.5 kb transcripts, the precore and the pregenomic RNA are made from it. A short sequence (from nt1744 to 1851, referred to as the basic core promoter or BCP) is identified, that is sufficient to direct the correct initiations of both precore and pregenomic messages. Sequences upstream of BCP (from nucleotide, nt1636 to 1744, referred to as the core upstream regulatory sequence or CURS) have a strong stimulatory effect on BCP. Deletion analysis of CURS suggests that it contains multiple regulatory elements that control BCP in an interactive manner. The CURS stimulates BCP in a position‐ and orientation‐dependent manner. Therefore, it is unlikely that the effect is mediated through the enhancer II that has been co‐localized to the same seq

ISSN:0815-9319    

DOI:10.1111/j.1440-1746.1993.tb01668.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

AbstractThe nucleocapsid core of hepatitis B virus (HBV) is composed of the hepatitis B core antigen (HBcAg), a viral genome, a polymerase and a protein covalently linked to the 5'‐end of the minus DNA strand. The interactions among the constituents are still very limited. By using thein vitrophosphorylation method, it was found that thepgene product formed complexes with HBcAg in the core particles through non‐covalent linkage. After complete digestion of the HBV genome, the complexes between the HBcAg andpgene product remained intact. These results indicate that the HBcAg andpgene product are not complexed through the HBV genome. Also, it was found that the 21 kD HBcAg formed oligomers through disulfide linkages in the extracellular viral partic

ISSN:0815-9319    

DOI:10.1111/j.1440-1746.1993.tb01669.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

AbstractHepatocellular carcinoma (HCC) has been documented to be associated with a multifactorial aetiology including hepatitis B virus (HBV), hepatitis C virus, exposure to aflatoxin, tobacco and alcohol. With the specific aim to examine the relationship between HCC and frequency of sister chromatid exchange (SCE) in peripheral lymphocytes as an indicator of integral carcinogen exposure, a total of 14 newly diagnosed untreated HCC patients and 13 healthy controls were studied. Study subjects were matched on age, sex, cigarette smoking and alcohol intake. Peripheral blood samples were collected using heparinized vacuum syringes. Lymphocytes were cultured in RPMI 1640 medium containing fetal calf serum and phytohaemagglutin. After lymphocytes were cultured for 24 h, 5‐bromo‐2‐deoxy uridine was added to the medium and colcemid was added after 70 h. Cells were harvested and fixed in methanol‐acetic acid (3 : 1) solution after 72 h. Cells were first stained with 33258 Hoechst and restained with Giemsa. Photographs were taken from at least 32 lymphocytes at the second metaphase of each study subject. The frequency of SCE was scored by two readers blindly. There was a significantly increased SCE frequency in peripheral lymphocytes of HCC patients than healthy controls, with a mean ± standard deviation of 15.1 ± 4.4 and 8.9 ± 2.7 SCE per metaphase II, respectively. The increased SCE frequency in lymphocytes of HCC patients may be due to the chronic HBV infection, exposure to chemical hepatocarcinoge

ISSN:0815-9319    

DOI:10.1111/j.1440-1746.1993.tb01670.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

AbstractIn order to study the implications of isolated hepatitis B surface antigen (HBsAg) positivity, 24 041 serum samples from schoolchildren aged 6–12 years were tested for HBsAg, antibody to HBsAg (anti‐HBs) and antibody to hepatitis B core antigen (anti‐HBc) by radio‐immunoassay. Five hundred and sixty‐two (2.3%) of the 24 041 cases were positive for HBsAg but negative for both anti‐HBs and anti‐HBc. The second and third testings were performed 1–4 and 5–9 months after the initial testing. The cases of group (V), those who lost HBsAg within 9 months, had low titres of HBsAg and were negative for both hepatitis B e antigen (HBeAg) and antibody to HBeAg (anti‐HBe); the cases of group (H), those who remained isolated HBsAg positive in the last testing, had high titres of HBsAg and were positive for HBeAg. Hepatitis B virus (HBV) DNA were detected by polymerase chain reaction method using oligonucleotide primers derived from C and pre‐C regions in 20 sera of group (V) and 11 sera of group (H). However, using primers from the S region, HBV DNA was detected in only 11 sera of group (H), but in none of 20 sera of group (V). On sequencing of HBV DNA from each two sera of both groups, nucleotide and amino acid sequences of C and pre‐C regions with high homology to that of the HBV‐adr strain were obtained from sera of both groups and also for S regions in group (H) but not in group (V). It is concluded that isolated HBsAg positivity could be ascribed to (i) HBV‐variant with probable mutation in the S region — (H); and (ii) immune incompetence of the host — (H); with prevalence rates of 2.17 and 0.087%, respectivel

ISSN:0815-9319    

DOI:10.1111/j.1440-1746.1993.tb01672.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

AbstractHepatitis B virus (HBV) infection and related diseases represent some of the major public health problems in Senegal. The prevalence of hepatitis B surface antigen (HBsAg) in infants increased steadily during their first years of life. HBsAg prevalence was 6% at 6 months of age and 13% at 2 years. HBV infection was detected in 30% at 2 years of age and in more than 90% of the population after the age of 10. Hepatitis B e antigen was detected in only 13–19% of HBsAg‐positive adults.As a consequence of this high frequency of HBV infection occurring early in life, a high frequency of hepatocellular carcinoma is observed in Senegal, with only two‐thirds of them being HBsAg carriers. However, the HBV genome was detected in 58% of HBsAg‐negative patients suffering from liver cirrhosis or primary liver cancer confirming the aetiological link between HBV and primary hepatic carcinoma in HBsAg‐negative patients. On the other hand, confirmed HCV infection has been detected in only 7% of the HBsAg‐negative liver cancer cases.More than 95% of the vaccinated infants had protective antibodies to HBsAg after a primary set of vaccine doses; this proportion decreased to 80% 6 years later and to 73% 10–12 years later. HBsAg was detected in 25% of infants from the control group and in 2.1% of immunized infants corresponding to an efficacy of more than 90%. No difference was observed between infants who received a booster dose at school age and those who did not. On the other hand, the results show that hepatitis B vaccine may be introduced into the existing recommended Expanded Programme on Immunization schedules without reducing the immune response to any of the currently recommended antigens nor increasing the frequency of untow

ISSN:0815-9319    

DOI:10.1111/j.1440-1746.1993.tb01673.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

ISSN:0815-9319    

DOI:10.1111/j.1440-1746.1993.tb01665.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY