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One hundred and five hepatitis B surface antigen (HBsAg) positive patients presenting with chronic persistent hepatitis (n = 46) or chronic active hepatitis without cirrhosis (n = 59) were followed longitudinally for one to 16 years (mean 5.5 years) and underwent follow up biopsy. During a mean histological follow up of 3.7 years, active cirrhosis developed in 21 (20%) patients one to 13 years after entry to the study with a calculated annual incidence of 5.9%. The probability of evolution to cirrhosis was significantly higher in patients with chronic active hepatitis and bridging hepatic necrosis than in those with moderate chronic active hepatitis or chronic persistent hepatitis (p less than 0.0001). Cox multiple regression analysis showed that the following three variables independently implied poor prognosis: older age, presence of bridging hepatic necrosis, and persistence of hepatitis B virus DNA in serum (p less than 0.0001). These findings indicate that patients with severe chronic active hepatitis and persistent hepatitis B virus replication are at very high risk of rapid progression to cirrhosis.

Medical, nursing, laboratory and other staff of the Mersey Regional Blood Transfusion Centre at risk of acquiring hepatitis B were vaccinated against the virus with a recombinant vaccine. Altogether, 86% staff developed greater than 10 mIU/ml antibody to hepatitis B virus surface antigen after immunisation but the proportion was lower in older staff. After a further injection of vaccine was given to poor and non-responders the overall proportion responding rose to 93%. The difference in response between the sexes was significant. Women had a higher rate of response and, among those persons responding, women developed a higher concentration of antibody.

More than 90% of lipids of hepatitis B virus surface antigen (HBsAg) particles produced by two human hepatoma cell lines (huGK-14 and PLC/PRF/5) were composed of phospholipids, with phosphatidylcholine being the dominant component, accounting for more than 80% of total membrane lipids. Analysis of subclass compositions of phospholipids of HBsAg particles and the host cell lines revealed that 1,2-diacyl glycerophosphocholine was preferentially incorporated into the membrane of the HBsAg particles, although both host cell lines contained extremely high concentrations (more than 60% of total phospholipids) of ether-linked phospholipids. Phospholipids of other hepatoma cell lines (HuH-7, Hep-G2, and huL-1) which were not associated with hepatitis B virus (HBV) infection, were composed mostly of 1,2-diacylglycerophospholipids. Activities of dihydroxyacetone-phosphate acyltransferase, which is known to be an obligatory enzyme in ether lipid biosynthesis, were found to be elevated by three- to fourfold in both huGK-14 and PLC/PRF/5 cells compared to those of other hepatoma cell lines. The results suggest a possible relationship between HBV-induced hepatocellular carcinogenesis and the drastic change in the metabolism of membrane phospholipids.

Markers of hepatitis-B virus (HBV) infection were determined in 42 patients with chronic liver disease (CLD) and in 42 age and sex matched healthy controls. At least one marker for HBV was found in 38 patients (90%) and in 29 controls (69%). HBsAg was present in 29 patients (69%) as opposed to 14 controls (33%; p less than 0.001). The very high prevalence of HBV infection, the significant difference with respect to HBV markers, particularly HBsAg, between patients and controls and in particular the high percentage of healthy HBV-carriers poses a considerable risk to the population of North-Sulawesi and stresses the need for HBV-vaccination.

The aim of this study was to evaluate the long-term outcome of chronic hepatitis B in 27 children who had increased alanine aminotransferase activity and antibody to hepatitis B e antigen in serum from the time of their first clinical observation. Initial histologic changes were consistent with chronic active hepatitis in 13 cases (three with associated cirrhosis) and with persistent or lobular hepatitis in the remaining cases. On the basis of virologic testing, three groups of patients were identified: (1) two children had hepatitis delta antigen in the liver and anti-delta antibody in serum, and both had severe hepatitis; (2) 10 children had hepatitis B virus DNA in serum, and 60% of them had active hepatitis; (3) 15 patients had no hepatitis B virus DNA, and 33% of them had active hepatitis. During a follow-up period of 12 months to 12 years (mean +/- SD: 6.1 +/- 2.4 years), the disease remained active in both children with anti-delta antibody, but they had no major complaints. In all eight patients who could be followed in group 2, test results became negative for hepatitis B virus DNA and alanine aminotransferase activity normalized within 4 years; biochemical remission was delayed in three patients with higher hepatitis B virus DNA levels on entry, and one of these patients had a severe exacerbation of disease activity before remission. In group 3, a total of 10 patients (71%) achieved biochemical remission within 1 year, and two within 26 months; only two patients, who were transfused at birth, had long-lasting liver damage. These results indicate a trend to early remission of liver disease in children with chronic hepatitis B with antibody to hepatitis B e antigen without delta virus infection. Antiviral therapy aimed at accelerating the termination of hepatitis B virus replication may be indicated only in those with higher levels of hepatitis B virus DNA.

Sera from 20 Chinese patients with chronic hepatitis B were examined for hepatitis B e antigen and hepatitis B virus (HBV) DNA. There was considerable discordance with HBV DNA not being detectable in 10 out of 13 (77%) patients who were hepatitis B e antigen positive. Further testing for anti-HBe and HBV-DNA polymerase activity confirmed the results. Possible reasons for this discordance are discussed but neither hepatitis D (delta) infection nor the acquired immunodeficiency syndrome (AIDS) could be implicated.

Hepatitis B, a major public health concern worldwide, is caused by hepatitis type B virus, a hepdnavirus that infects only human and certain nonhuman primates, and replicates strictly in hepatocytes. By using the techniques of slot and Southern blot DNA hybridization, and electron microscopy, the presence of HBV was identified in the cerebrospinal fluid of three affected individuals.

Vaccines and chemotherapy may soon strengthen the armamentarium for control of type B hepatitis. The incidence of type A is still declining in the U.S., and now that type non-A, non-B has been transmitted to animals, a marker for it is being widely sought.

Hepatitis B surface antigen (HBsAg) of subtype ay predominates among narcotic addicts infected with hepatitis B virus (HBV) in Europe, Australia and the United States. However, the ad subtype predominates among the non-addict carriers of HBsAg. We investigated the possibility that heroin lots were contaminated with HBV at a source of opium production, the Middle East, a geographical region where HBsAg/ay predominates in the general population. One hundred and nine lots of street heroin were assayed for HBsAg by radioimmunoassay. None of the lots tested was reproduceably HBsAg positive. These results suggest that the heroin itself is not responsible for the high incidence of HBV infection or for the predominance of HBsAg/ay in the addict population. The predominance of HBsAg/ay among addicts in Europe and Australia as well as the United States might be due to extensive needle sharing among a mobile population of drug abusers, although such worldwide dissemination of one subtype by these means is unlikely.

Sera from 153 Israeli patients in various stages of hepatitis B virus (HBV) infection with undetectable hepatitis Be antigen (HBeAg) were studied for the presence of HBV DNA in the serum by molecular hybridization. HBV DNA was detected in 10 patients: 3 with acute hepatitis, 4 asymptomatic hepatitis B surface antigen (HBsAg) carriers, 1 with chronic active hepatitis, 1 with cirrhosis, and 1 with mixed cryoglobulinemia. HBV DNA was detected in 7 of 10 HBeAg-positive control samples tested. Hybridization analysis was used for quantitative comparison of HBV DNA levels in serum. HBV DNA levels, found in HBeAg-negative patients sometimes exceeded the levels found in HBeAg-positive patients. Restriction enzyme analysis of serum HBV DNA from four HBeAg-negative samples gave undistinguishable digestion patterns as compared to 3 HBeAg-positive samples. However, heterogeneity in HBV DNA restriction fragments was detected among HBV genomes in sera of HBeAg-positive samples. These data demonstrate that HBV DNA may be present in the serum at various stages of HBV infection, regardless of HBeAg detection. Failure to detect HBeAg in these patients does not necessarily reflect low serum levels of viral particles, or the occurrence of HBV genome variants.

We measured serum aspartate transaminase (AST) concentration and serum hepatitis B virus (HBV) DNA concentration in homosexual men with chronic HBV infection and a spectrum of immune deficiency as a result of exposure to human immunodeficiency virus (HIV). Serum AST and HBV DNA concentrations were similar in patients with varying immune function as indicated by in vivo criteria (diagnosis and skin tests reactivity) and in vitro criteria (lymphocyte transformation responses to mitogens and Candida and tetanus antigens) and were unrelated to the number of circulating T cells, suppressor/cytotoxic cells, helper cells, natural killer cells, and the helper:suppressor ratio. Serum AST concentration and indices of cellular immune function were similar in patients with varying HBV replicative activity (high and low HBV DNA concentrations). The observed lack of relationship between serum AST concentration and indices of cellular immune function and HBV replication suggests either that other factors determine the severity of hepatic inflammation in chronic HBV infection, or that currently available tests of cellular immune function and HBV replicative activity do not accurately reflect processes in the liver.

Forty-five patients with chronic hepatitis B were entered into a randomized controlled trial of recombinant human alpha-interferon therapy. All patients had hepatitis B surface antigen in serum for at least 1 yr and had stable serum levels of both hepatitis B virus deoxyribonucleic acid and hepatitis B e antigen. During the 4-mo period of therapy, 10 of 31 (32%) treated patients and only 1 of 14 (7%) control patients became negative for serum hepatitis B virus deoxyribonucleic acid and deoxyribonucleic acid polymerase. All 10 patients who became negative for serum hepatitis B virus deoxyribonucleic acid subsequently had a marked improvement in serum aminotransferase activities and lost hepatitis B e antigen from serum, and 9 of them had improvement in liver histology. Comparison of responders to nonresponders indicated that female sex and a high initial level of serum aspartate aminotransferase correlated best with response to interferon therapy. These findings indicate that a 4-mo course of recombinant alpha-interferon can induce a remission in disease in approximately one-third of patients with chronic hepatitis B.

Two antigenic systems of the woodchuck hepatitis virus have been identified. The relationship between viral antigens of the woodchuck hepatitis virus and the human hepatitis B virus was determined by using immunoprecipitation, hemagglutination, and immune electron microscopy techniques. Antigens found on the cores of the two viruses were cross-reactive. Lack of cross-reactivity between the surface antigens of the two viruses in immunodiffusion experiments suggested that the major antigenic determinants of the viral surfaces are different; however, results of passive hemagglutination tests indicated that there are common minor determinants. Nucleic acid homology, as measured by liquid hybridization, was found to be 3 to 5% of the viral genomes. The results of this study provide further evidence that woodchuck hepatitis virus is the second member of a new class of viruses represented by human hepatitis B virus. Since virus-infected woodchucks may acquire chronic hepatitis and hepatocellular carcinoma, these antigens and their respective antibodies will be useful markers for following the course of virus infection in investigations of the oncogenic potential of this class of viruses. The nucleocapsid antigen described may be a class-specific antigen of these viruses and, thus, may be useful in discovering new members of the group.

A collection of 1,985 lots of normal serum albumin (NSA) and 1,361 lots of plasma protein fraction (PPF) prepared between 1958 and 1974 were tested for the presence of hepatitis B surface antigen (HBsAg). Twenty-one percent of NSA lots and 71 per cent of PPF lots were HBsAg-positive by radioimmunoassay. There was considerable variation in frequency of HBsAg-positive lots among the 17 different manufacturers of NSA and the six manufacturers of PPF. In general, those lots prepared from volunteer donor plasma and placental material demonstrated lower rates of HBsAg-positivity than those prepared from commercial donor plasma. A striking decrease in the prevalence of HBsAg-positive lots of both NSA and PPF occurred during the period 1971 to 1973, coincident with the onset of routine screening of all plasma for HBsAg. Although NSA and PPF can be HBsAg-positive, they probably do not transmit type B hepatitis. Serologic tests for HBsAg and antibody to HBsAg revealed that albumin products prepared from infectious, icterogenic plasma were infectious prior to pasteurization, but that they no longer transmitted type B hepatitis after heat treatment at 60 C for ten hours.

Conventional HBV serological markers, as well as serum alanine amino transferase and hepatitis B virus DNA (HBV DNA) were studied in a population of 667 institutionalized mentally handicapped males and females and in 676 staff members. The role of Down's syndrome (DS), sex and age-related factors with respect to the prevalence of these markers was analyzed. A young age at admission was found as one of the important factors in the development of the chronic HBsAg carrier state in females. The well-known higher prevalence of HBsAg carriership in DS patients appeared to be restricted to males. Markers indicative of viral replication, HBeAg and HBV DNA, were also more prevalent in male than in female DS residents, or OMR residents. These findings indicate that the phase of active viral replication is prolonged in male HBsAg carriers with DS. However, only 66.7 per cent of HBV DNA-positive and 26.2 per cent of HBsAg-positive residents had abnormal serum alanine aminotransferase (ALT) values. In addition, more than 50 per cent of residents with elevated serum alanine amino transferase values were negative for HBV serological markers. We conclude that male DS residents are the main source of HBV infection in institutions for the mentally handicapped and that determination of ALT values is not very useful in identifying those HBsAg carriers capable of transmission the infection.

1065 sera from patients with acute and chronic hepatitis-B-virus-(HBV-) infections, double infections (HBV, HAV, nonA-nonB, delta-Ag) as well as patients with HBs-Ag-negative hepatitis (HAV, nonA-nonB) and healthy subjects were investigated for the presence of hepatitis-B-virus-DNA using molecular hybridisation. The sensitivity of the method was 0.1 pg HBV-DNA/100 microliters. HBV-DNA could be detected in 62% of cases of HBs-Ag-positive sera with HBe-Ag, in 8.9% with anti-HBe and in 11% of e-marker free sera. In acute hepatitis HBV-DNA was present in 44%, in chronic hepatitis in 71% of HBe-Ag-positive sera. In HBs-Ag-negative sera containing only anti-HBc, HBV-DNA, depending on the anti-HBc-titre, was present in 13-24% of cases. HBV-DNA could not be detected in patients with HBV infections (anti-HBc and anti-HBs positive) in the past or in HBV-marker-negative hepatitis. Follow-up investigations on acute and chronic HBV-infections showed that the disappearance of HBV-DNA generally preceded the disappearance of HBe-antigen by about 2-3 weeks. In chronic hepatitis the time interval can amount to several months or years. Double infections with other hepatotropic viruses (nonA-nonB and delta-virus) can lead to a temporary suppression of HBV-DNA replication.

A commercial radioimmunoassay was adapted to detect serum Dane particle-associated HBeAg in patients whose sera contained homologous antibody. HBeAg was released from Dane particles with guanidine HCl. Dane particles were separated from anti-HBe by gel-filtration (Sepharose 4B) and ultracentrifugation of the eluate. Dane particle-HBeAg was tested in 45 HBsAg carriers with anti-HBe and was present in 8 (18%) carriers, all of whom had chronic liver disease. By contrast, HBeAg was not found in 10 carriers with normal liver histology. Serum or liver HBcAg was found in 6 of 8 patients with Dane particle-HBeAg. None of the carriers without Dane particle-HBeAg had other markers of hepatitis B virion synthesis. We conclude that Dane particle-HBeAg provides a sensitive index of active hepatitis B virus replication, a guide to the presence of chronic hepatitis in HBsAg carriers with anti-HBe, and a noninvasive method to follow infection in these patients.

Twenty-one pretreatment variables were assessed for their significance in response prediction using data from 114 patients given alpha-interferon for chronic hepatitis B virus infection. In those patients who had received a minimum of 90 million units per m2 total dose over 12 weeks, a negative anti-human immunodeficiency virus antibody status (p less than 0.001), chronic active hepatitis on liver biopsy (p less than 0.005), high AST level (p less than 0.001), low hepatitis B virus DNA level (p less than 0.001) and a history of acute hepatitis (p less than 0.005) were all associated with an increased likelihood of response on univariate analysis. On stepwise logistic regression analysis, hepatitis B virus DNA, AST and a history of acute hepatitis predicted response independently (p less than 0.05). The most reliable combination of predictive factors was a negative anti-human immunodeficiency virus antibody status, with either a positive history of acute icteric hepatitis and AST greater than 45 IU per liter or no history of acute icteric hepatitis and AST greater than 85 IU per liter, which predicted response in 77% with a specificity of 79% (p less than 0.001). The loss of HBsAg in addition to HBeAg and hepatitis B virus DNA was more likely to occur in patients with chronic infection of less than 2 years duration (p less than 0.001).

Particles with properties similar to those associated with human hepatitis B were found in serum from woodchucks with chronic hepatitis and hepatocellular carcinoma. It is suggested that woodchuck hepatitis virus is a second member of a novel class of viruses represented by the human hepatitis B virus.

In situ hybridisation was used to detect RNA of Hepatitis B virus (HBV) in peripheral mononuclear blood cells. Presence of HBV-RNA was detected in 10/17 HBsAg positive HBeAg positive patients, in 8/18 HBsAg positive HBeAg negative patients, in 1/3 anti-HBs positive subjects. Four control subjects were negative. The frequency of labelled cells varied from 1 to 10% of mononuclear cells. These results indicate that the DNA detected so far in mononuclear blood cells may be transcriptionally active.

The core of the Dane particle was shown to contain a DNA polymerase and a circular double stranded DNA with a molecular weight of 1.6 X 10(6) daltons which served as the primer-template for the enzyme. The product of the DNA polymerase reaction was in a base paired form and was covalently attached to the circular DNA. Neither the circular DNA nor the attached DNA product of the enzyme reaction was attacked by the DNase or released from intact cores until the cores were disrupted with sodium dodecyl sulfate, suggesting that they are internal components of the core. The DNA polymerase is a specific marker for Dane particles and can be used to distinguish sera with high and low concentrations of Dane particles. The DNA polymerase reaction can also be used to radiolabel Dane particle cores for a specific and sensitive radioimmunoprecipitation assay for antibody against the hepatitis B core antigen (anti-HBc).

Receptors for polymerized human serum albumin ( pHSA ) were studied by solid-phase radioimmunoassay on different hepatitis B surface antigen (HBsAg) particles subpopulations prepared both from hepatitis B e antigen (HBeAg) and from anti-HBe-positive sera. HBsAg particles in HBeAg-positive serum showed higher expression of the receptor compared with HBsAg particles from anti-HBe-positive serum. Analysis of different morphological forms of virus particles was performed after separation by density-gradient ultracentrifugation. Maximum receptor expression was detected in HBV particles containing fractions while the 22-nm HBsAg particles had significantly lower receptor activity. These observations support the hypothesis of a pathogenetic role of the pHSA receptor in mediating virus access to hepatocytes. Indeed, the higher pHSA binding activity on HBV particles could allow selective attachment of the infectious virion to liver cells that bear similar albumin receptors on their surface.

The sera of 15 individuals with transfusion-associated acute or chronic non A, non B hepatitis, which lacked hepatitis B virus markers, were tested for hepatitis B virus DNA by dot blot hybridization test. Three sera of two patients positive in this test, however, also gave positive results when the labeled plasmid was used as probe instead of labeled HBV-DNA, indicating false positive results in the initial test. In conclusion, the data indicated that sera of patients with confirmed non A, non B hepatitis do not contain DNA-sequences in the serum hybridizing with HBV-DNA.

Complete and defective hepatitis B virus (HBV) particles in sera and hepatocytes were observed by electron microscopy for an understanding of the maturation process of hepatitis B virus. To distinguish Dane particles with or without DNA on the basis of staining density with uranyl acetate, Dane particles, purified from sera of asymptomatic carriers, and Dane particle cores, separated by ultracentrifugation in a metrizamide density gradient, were observed by electron microscopy. Complete cores at a low density (1.19 to 1.23 gm/cm3) were electron dense and incomplete cores at a high density (1.23 to 1.27 gm/cm3) were partially electron dense or empty. These findings demonstrated that the presence or absence of DNA is reflected by the electron density of the core. Our result, in which less than 10% serum Dane particles have full cores in ultrathin sections of the pellet, is in agreement with Gerin's finding that defective Dane particles are predominent in sera. Naked core particles and Dane particles in two biopsy specimens from patients with hepatitis B surface antigen, hepatitis B e antigen, and DNA polymerase-positive, chronic active hepatitis were classified into complete versus incomplete particles on the basis of electron density. Nine hundred and fourteen naked core particles were detected in nuclei and cytosol of 68 hepatocytes. One hundred and five core particles (11.5%) were electron dense and 809 core particles (88.5%) were partially electron dense or empty. Furthermore, 488 Dane particles were observed in the cisternae of the endoplasmic reticulum of these hepatocytes. Fifty Dane particles (10.2%) had full cores, and 438 Dane particles (89.8%) had partially full or empty cores. These findings suggest that DNA may be incorporated into about 1 to 10% of core particles when they are assembled in nuclei of hepatocytes. Morphologic differences in damage to hepatocytes containing various frequencies of full Dane particles were also studied, but no significant correlation was found between damage in hepatocytes and frequency of full Dane particles.

DNA from the pre-S region of the duck hepatitis B virus (DHBV) genome was inserted into an open reading frame vector designed to give high-level expression in Escherichia coli. The resulting fusion protein contained the first 8 amino acids of beta-galactosidase, 86 amino acids of the DHBV pre-S region, and 219 amino acids of chloramphenicol acetyltransferase at the C terminus (beta-gal:pre-S:CAT). Rabbit antiserum against purified beta-gal:pre-S:CAT was used to identify pre-S-containing polypeptides in DHBV particles by Western blotting. A dominant species of 36 kilodaltons (kDa) was identified. Antiserum against the major 17-kDa DHBsAg polypeptide also reacted with the 36-kDa protein. This suggests that the DHBV envelope gene polypeptides share the same carboxyl terminus, but differ in the sites from which translation is initiated. N-linked carbohydrate was not detected on either the 17- or 36-kDa envelope proteins. Anti-beta-gal:pre-S:CAT abolished infectivity of the virus in an in vitro assay. Thus, the pre-S region is exposed on the surfaces of infectious virions and may be directly involved in binding of virus to host-cell receptors.

During the past decade new development in hepatitis research have shed new light on the etiologic, epidemiologic, immunologic, and prophylactic aspects of type A and B hepatitis virus infection. Recent advances in hepatitis A virus research include: (1) identification of the virus as a 27 nm particle with characteristics resembling an enterovirus, (2) transmission of the infection to marmosets and chimpanzees, and (3) development of specific complement fixation and immune adherence antibody tests. Recent advances in hepatitis B research include: (1) identification of the virus as a 42 nm particle (Dane particle) containing an outer coat, the hepatitis B surface antigen, and an inner core, the hepatitis B core antigen, (2) development of specific tests to detect the hepatitis B antigens and their respective antibodies, (3) transmission of the infection to chimpanzees, (4) development of a specific hepatitis B immune serum globulin, and (5) development of an inactivated hepatitis B vaccine.

Different population groups from the Shanghai area were surveyed by radioimmunoassay for serologic markers of previous infections with hepatitis A virus and hepatitis B virus. There were no significant differences in the prevalence of antibodies to hepatitis A virus (anti-HAV) in males and females, or in persons living in rural or urban areas. The prevalence of anti-HAV showed a biphasic increase with age, approaching 100% above age 50 years whereas the geometric mean titers declined. The rate of infection (attack rate) with hepatitis A among susceptibles in Shanghai declined appreciably between 1950 and 1960. The prevalence of hepatitis B markers also did not differ in the sexes, or in rural and urban populations. The patterns of prevalence of hepatitis B markers at different ages were compared to various theoretical mathematical models, and the data fitted best a model constructed from the assumption that two subpopulations of approximately equal size, one at low and the other at high risk, existed in the population groups studied. It was estimated that in Shanghai up to 12% of all individuals infected with hepatitis B became chronic hepatitis B surface antigen (HBsAg) carriers, although the overall prevalence of HBsAg carriers was only 6.9%. All HBsAg-positive individuals subtyped had been infected with hepatitis B virus of the subtype ad; 41.7% of HBsAg carriers also had hepatitis B e antigen (HBeAg), whereas in 32% of HBsAg carriers antibodies to HBe were present. Antibodies to HBsAg appeared to be lower in titer than in Western populations and to decline with age, and age-specific prevalence data indicated a relatively longer persistence of antibodies to hepatitis B core antigen.

A radiolabeled probe specific for hepatitis B virus (HBV) nucleotide sequences was hybridized in situ to liver tissue from three patients with chronic hepatitis B. The HBV genome was detected not only in infected hepatocytes but also in bile duct epithelial cells, endothelial cells, and smooth muscle cells. These findings extend the known host cell range for HBV, suggest new mechanisms of viral dissemination, and illustrate the usefulness of in situ hybridization in the study of pathogenesis of HBV infection.

Forty six selected autopsy livers with hepatic disorders were classified histologically into three groups, i.e., hepatitis 8, liver cirrhosis 16 and hepatocellular carcinoma 22, chiefly by histological findings. These groups were subdivided into two categories after determining the presence or absence of three HBV associated markers, i.e., the hepatitis B surface antigen (HBsAg), the antibody to hepatitis B surface antigen (anti-HBs) and the antibody to hepatitis B core antigen (anti-HBc) in the sera and liver homogenates. At least one of these markers was found to be present in the sera and homogenates of 38% of the livers with hepatitis, 69% of the livers with liver cirrhosis and 77% of the livers with hepatocellular carcinoma. When the liver tissues were examined for the presence of HBV DNA using Southern blot technique, the majority of them (10 out of 11) which proved to be positive for at least one HBV associated marker were also positive for HBV DNA. However, HBV DNA could not be detected in the other 10 livers which contained no HBV associated markers. These results showed that a HBV associated serological marker was always expressed, when liver tissue HBV DNA was demonstrable. The results of the two detection methods we used in this study were found to be almost equivalent. These results showed no evidence of nucleic acid homology between DNA from the liver of patients with non-B type liver disorders and HBV DNA.

Thirty-five 1-day-old Pekin-Aylesbury ducks were inoculated intravenously or intraperitoneally with duck hepatitis B virus, and the time-course of infection was examined by Southern-blot, dot-blot, and in situ hybridization and by immunohistochemistry. Randomly scattered single infected hepatocytes were first seen on days 1 and 2 after inoculation and by day 3 occurred as single cells, pairs, and groups of 5-10 adjoining cells. From day 4 after inoculation all hepatocytes were positive for duck hepatitis B surface antigen and deoxyribonucleic acid. Duck hepatitis B virus deoxyribonucleic acid levels in liver extracts and serum increased logarithmically from days 2 to 3 to a plateau by days 4 to 5 after inoculation. Infected and control birds showed no significant differences during the first 7 days in terms of liver histology, hepatocyte morphology, or mitotic activity. It was concluded that (a) virus gains access to randomly distributed hepatocytes without first replicating in other cell types, and then begins disseminating to adjacent cells following anatomic boundaries; (b) markers of infection in liver and serum show reproducible kinetics, thus making this in vivo system amenable to further quantitative study; and (c) hepatocytes in this system are highly permissive to virus replication without the development of significant cytopathology.

The core and coat of hepatitis B virus were found by electron microscopy in parenchymal cells of a liver biopsy from a 61 year old man with chronic active hepatitis and cirrhosis of the liver. Laparoscopy, 35 days after liver biopsy, and autopsy 42 days later confirmed the cirrhosis and showed in addition a well differentiated hepatoma. The possibility of a viral aetiology for the cirrhosis and primary carcinoma of the liver is considered.

In order to determine the relationship between hepatitis B virus (HBV) infection of human white blood cells and different forms of HBV-associated liver diseases, we tested for HBV DNA in the sera and leukocytes of 11 healthy individuals without any serological markers of HBV infection and 91 patients with HBV infection and other gastrointestinal and urinary diseases by dot and Southern blot hybridization. HBV DNA was found in leukocytes of chronic HBV carriers, in acute and chronic hepatitis, and in patients with liver cirrhosis and hepatocellular carcinoma. Between 27 and 50% of individuals in different categories of patients examined were positive for leukocyte HBV DNA. HBV DNA was also detected in the sera of some of these patients but was absent in others. Serum HBV DNA-positive rates seemed to be highest in hepatitis B e antigen-positive asymptomatic carriers (8/10, 80%), and tended to drop to lower levels as the disease progressed to liver cirrhosis (0/8) while leukocyte HBV DNA-positive rates were highest in patients with cirrhosis (4/8, 50%). The results also show that in individuals who were serologically negative for hepatitis B surface antigen (HBsAg) and positive for antibodies to HBsAg and/or HBcAg, HBV DNA was absent in most of the sera (27/28, 96%) but it was present in leukocytes of some of these patients (7/28, 25%). In control experiments with 11 healthy individual, HBV DNA was not detected in either sera or leukocytes. In all the cases with leukocyte HBV DNA, the HBV DNA molecules were present in free forms with discrete sizes. The exceptions were a case of liver cirrhosis and a case of chronic hepatitis with possible HBV sequence integration into high molecular weight cellular DNA. Since HBV does infect human leukocytes, it may perhaps interfere with the immunological functions of the white blood cells, and thus play an important role in the pathogenesis of HBV-induced liver disease.

The circular DNA of hepatitis B Dane particles, which serves as the primer/template for an endogenous DNA polymerase, was analyzed by electrophoresis before and after a polymerase reaction and after digestion by restriction endonuclease or single-strand-specific endonuclease S1. The unreacted molecules extracted from the particles were electrophoretically heterogeneous, and treatment with S1 nuclease produced double-stranded linear DNA ranging in length from 1,700 to 2,800 base pairs (bp). After an endogenous DNA polymerase reaction, two discrete species of DNA molecules were found: a circular form and a linear form 3,200 bp long. The reaction resulted in a population of molecules with an elongated and more homogeneous double-stranded region. These results suggest that the circular molecules in Dane particles have single-stranded regions of varying lengths that are made double stranded during the DNA polymerase reaction. The endogenous DNA polymerase was found to initiate apparently at random in a region spanning more than a third of the molecule. Analysis of restriction endonuclease cleavage fragments of the fully elongated DNA revealed that although the molecules were of a uniform length, they were somewhat heterogeneous in sequence. The sum of the sizes of the 10 major endonuclease Hae III-generated fragments, detected by ethidium bromide, was 3,880 bp. Two additional fragments (B and G) detected by autoradiography after an endogenous DNA polymerase reaction with (32)P-labeled deoxynucleoside triphosphates made the total 4,910 bp.

Earlier reported findings of hepatitis B virus (HBV) DNA in white blood cells of patients with hepatoma, and in a patient with autoimmune haemolytic anaemia, led to the examination of HBV DNA in a series of twenty three patients with acquired immune deficiency syndrome (AIDS), including nine with opportunistic infections and fourteen with Kaposi's sarcoma, by Southern blot hybridization method, using 32P labelled HBV DNA specific probe obtained by nick translation of HBV DNA cloned into plasmid pBR325. Four of the patients were found to be positive for HBV DNA or HBV related DNA in their leucocytes. The HBV DNA was found free or integrated in the leucocytes of the patients.

Treatment of serum with sodium thiocyanate in HBs antigen carrier patients leads to liberation of circulating HBc antigen which can be demonstrated radioimmunologically. Investigations were done in 54 HBs antigen carriers, 44 of whom had chronic inflammatory liver disease (22 patients each HBe antigen positive and negative), and in 10 patients who were asymptomatic (so-called healthy HBs antigen carriers). Out of the 22 HBe antigen positive patients 17 were HBc antigen positive serologically. In the HBe antigen negative group of HBs antigen carriers two out of 22 patients with HBc antigen in serum were detected. All 10 asymptomatic HBs antigen carriers were HBc antigen negative. In 11 out of the 40 immunohistologically assessed patients HBc antigen could be demonstrated in hepatocellular nuclei; these 11 patients also demonstrated HBc antigen in serum. The liberated HBc antigen was associated with Dane particles in the density gradient. Serologic demonstration of HBc antigen may thus be considered as direct evidence of presence of hepatitis B virus.

Plasmid pHBV 114 DNA, which contains 73% of the genome of hepatitis B virus (HBV), was radiolabelled with tritium to 1-2 X 10(8) dpm/microgram by nick translation and used as a radioactive probe to detect HBV DNA present in sections of infected liver tissue by in situ hybridisation followed by autoradiography. Factors affecting the sensitivity of the reaction were examined, including different methods of fixation, hybridisation time, temperature, and buffers. The specificity of the reaction for detecting viral DNA was carefully established by the use of unrelated DNA probes, pretreatment of sections with DNAase, and comparing the stability of the binding of DNA probe at different temperatures, with the melting curve of double-stranded DNA in solution. In the one liver studied in detail, cells containing large amounts of viral DNA were distributed in foci corresponding to areas containing morphologically damaged hepatocytes. This observation suggested a relationship between active viral replication and cell damage. Viral DNA was found mainly in the cytoplasm, although a minority of nuclei in these foci were also positive.

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.

A model image of the organization of the HBV coat is proposed on the ground of published evidence, as well as the authors' own results concerning the dissociation of the viral coat into lipoprotein subunits devoid of HBsAg activity. Structural relationships are envisaged and the existence of a hypothetical polypeptide structure possessing hydrophobic and/or polar binding sites is inferred.

Five male patients with HbsAg-positive liver disease were treated with ara-A at dosages ranging between 5 mg and 10 mg/kg/day for five days. Before treatment, all of them had detectable DNA polymerase activity and HbeAg in their sera. The five-day course of the drug resulted in a rapid fall in DNA polymerase activity in every patient, the effect being dose-dependent. The amount of circulating Dane particles also decreased simultaneously, or with a short time lag, with the fall of the enzyme activity. The following decrease in HBeAg concentration was observed in all patients, and it was also noteworthy that antiHBe response was found in two of the five. HBsAg titers were significantly diminished in two patients. In the present series of ara-A treatment, these effects were temporary in two patients, while, in the remaining three, they lasted for two to three months. Ara-A had no serious side effects at dosages of 10 mg/kg/day or less, and can thus be counted among the valuable therapeutic drugs against chronic HBV infection.

Recombinant DNA techniques have recently contributed a great deal of informations on hepatitis B virus (HBV) infection. Serum HBV-DNA appeared as the most sensitive marker of viral replication activity both in hepatitis B e antigen (HBeAg)-positive and in anti-HBe-positive patients. In the latter group, a significant correlation between serum viral DNA positivity and liver disease activity was present. In our experience, more than 50% of anti-HBe-positive cases with chronic liver disease showed circulating HBV-DNA, while none of healthy HBsAg chronic carriers was found positive for serum HBV-DNA. In type B acute hepatitis, viral nucleic acid sequences were detectable only in a small number of uncomplicated cases, but were observed in all the patients who progressed to chronic hepatitis. HBV-DNA represents therefore an early and useful prognostic parameter in acute infection. Several epidemiological studies have established a striking correlation between HBV infection and development of hepatoma. Using molecular hybridization techniques, viral DNA has been identified in liver cancer cells. Finally, HBV-DNA has also been identified in the pancreas, kidney, skin, bile ducts and in cells of the vascular system. In addition, the presence of viral genome has been recently identified in circulating lymphocytes of patients with acute or chronic HBsAg-positive hepatitis. These findings add further informations to the understanding of viral biology and of virus-host interactions in the natural history of the infection and associated liver disease.

Techniques of recombinant DNA and molecular biology have recently been applied to the study of hepatitis B virus (HBV) in human tissues and have enhanced our knowledge of viral persistence and chronic liver disease. These molecular studies strengthen previous epidemiologic evidence for an association between HBV chronic carriers and hepatocellular carcinoma (HCC). A recently described group of animal viruses with structural and biological properties similar to HBV, termed Hepadna viruses, provides animal models for future studies of hepatitis B virus, especially with regard to the mechanisms for virus replication and persistance and the relationship of these processes to development of HCC.

Half the Dane particle concentrates isolated from 84 serum samples of patients infected with hepatitis B virus (HBV) contained more than one HBV DNA species. At most, six HBV DNA molecules migrated on hybridization blots. The fastest migrating species was single minus-strand DNA, and the five slower species all were double-stranded relaxed circular DNA. One of the latter forms corresponded to the full-length HBV genome; the four others contained shorter plus strands of different lengths and might represent replicative intermediates. These results indicate that the replicative forms of HBV previously found in infected liver cells might be coated and exported as early as the step of single minus-strand synthesis.