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Biomedical subjects

M J Fowler

Publications and source records attributed to M J Fowler.

At least 19 recordsLinked to original sources

Hepatocellular carcinoma: clinical, aetiological and pathological features in British patients.

We have examined the clinical, prognostic, aetiological and pathological features of 41 consecutive British patients with hepatocellular carcinoma (HCC). Presenting symptoms were often vague, and patients were generally in poor condition at diagnosis, 56% being of WHO grade 2 performance score or higher. Ascites (46%) and jaundice (35%) were often present at diagnosis, and the median duration of survival from diagnosis was only 6 weeks. Only initial performance grade (p less than 0.0001) and serum bilirubin concentration (p = 0.02) significantly affected prognosis. Serum alphafoetoprotein (AFP) was positive by counter-immune electrophoresis in only 34%, but increased to 68% when radioimmunoassay was used. Cirrhosis was present in 33 patients (80%) and was most often cryptogenic (12) or alcoholic (7) in origin. Serum HBsAg was detected in 5 patients (12%) and, of the remainder tested, 21% had serological evidence of past HBV exposure. None of 8 serum HBsAg-negative tumour specimens had detectable HBV-DNA integration into the tumour cell genome. Liver-cell dysplasia was noted in 56% of patients with liver biopsies predating the diagnosis of HCC, and in 78% of biopsies taken at the time of HCC diagnosis. The commonest histological pattern was trabecular (71%). Other forms were rare; the fibrolamellar pattern was only seen in 2 patients.

Adolescent

Hepatocellular carcinoma and the hepatitis B virus: a study of British patients.

We have examined the relationship between hepatitis B virus infection and hepatocellular carcinoma in a series of 50 British patients with histologically-proven hepatocellular carcinoma. Serum HBsAg was detected in 10 patients (20 per cent), and of the remainder, 21 per cent of those tested had serological evidence of past hepatitis B virus exposure. None of nine tumour specimens from serum HBsAg negative patients had detectable HBV-DNA integration into the tumour cell genome. The presence or absence of serum HBsAg was of no prognostic significance in British patients with hepatocellular carcinoma. Liver cell dysplasia, a possible pre-malignant lesion, was noted in 53 per cent of patients who had had liver biopsies before the diagnosis of hepatocellular carcinoma, and in 79 per cent of biopsies taken at the time of diagnosis of hepatocellular carcinoma. The presence of liver cell dysplasia was not more common in serum HBsAg positive patients.

Adolescent

Integration of HBV-DNA may not be a prerequisite for the maintenance of the state of malignant transformation. An analysis of 110 liver biopsies.

Hundred and ten liver biopsy specimens from various parts of the world were examined for episomal and integrated HBV-DNA sequences. In 54 patients with HBsAg chronic liver disease episomal HBV-DNA was found in 83% of HBeAg-positive patients, compared to only 22% of patients with anti-HBe. Furthermore episomal HBV-DNA in the latter predominated among the Asians. Integrated HBV-DNA was found only in 5.5% of HBeAg-positive patients but in 16.5% of patients with anti-HBe. In 28 HBsAg-positive patients with hepatoma, episomal HBV-DNA was found in 50% of HBeAg-positive patients but in only 11% of anti-HBe patients. Conversely integrated sequences were less common (25%) in HBe-Ag-positive patients than in anti-HBe patients (50%), giving an overall incidence of integration in this group of 45%. No episomal, and only one case of integrated sequences of HBV-DNA, could be detected among 10 patients with HBsAg-negative hepatoma. In addition neither episomal nor integrated HBV-DNA could be detected in 18 patients with non-HBV-related liver disease. Our data suggests that stable integration of HBV-DNA into the host's genome is not necessarily a prerequisite for the maintenance of the state of malignant transformation but may be necessary for its initiation. Alternatively, the detection of integrated HBV-DNA may represent a 'snap shot' of a random integration event amplified by clonal expansion promoted by other factors.

Base Sequence

Cloning and analysis of integrated hepatitis B virus DNA of the adr subtype derived from a human primary liver cell carcinoma.

A 10 kb genomic DNA fragment derived from a human primary liver cell carcinoma (PLC) and containing integrated hepatitis B virus (HBV) DNA was cloned and analysed. Physical mapping showed the viral DNA to comprise a linear sequence of at least 2.8 kb (87%) of the HBV genome and to be of the adr subtype. Integration appeared to have occurred in the region of the viral genome spanning the cohesive ends. The cellular flanking DNA sequences to one side of the integrated viral DNA contained repeats of the Alu family. The finding of no apparent rearrangements of the integrated HBV DNA sequences in this clone is in contrast to the situation in the huSP and PLC/PRF/5 PLC cell lines in which the integrated viral DNA sequences are greatly rearranged and suggests that such rearrangements may be atypical of solid PLCs.

Base Sequence

Hepatitis B virus and primary liver cell carcinoma. The application of molecular biology.

Worldwide, primary liver cell carcinoma (PLC) is one of the most common tumours. Epidemiological evidence has implicated hepatitis B virus (HBV) in its aetiology and the mechanisms whereby HBV could operate at the genomic level have been investigated using the techniques of molecular biology. The resemblance of certain features of HBV to the retroviruses has also suggested mechanisms whereby malignant transformation may take place, but as yet there is no clear evidence for HBV being directly oncogenic. This has suggested to some that it is the persistent inflammatory reaction caused by HBV infection that is instrumental in causing PLC. We believe, however, that HBV can act independently of this mechanism and that the failure so far to show this at the molecular level may be due to technical reasons.

Carcinoma

Hepatitis B virus DNA in saliva, urine, and seminal fluid of carriers of hepatitis B e antigen.

Concentrated samples of saliva, urine, and seminal fluid from 23 men with chronic liver disease who were positive for hepatitis B e antigen were examined for the presence of hepatitis B virus deoxyribonucleic acid (HBV-DNA) by molecular hybridisation. HBV-DNA was detected in saliva from 15 of 17 men (88%), urine from 12 of 22 men (55%), and seminal fluid from 13 of 21 men (62%). The presence of hepatitis B virus in such secretions has important epidemiological implications for heterosexual and homosexual contact.

Autoradiography

Studies of HBV replication during acute hepatitis followed by recovery and acute hepatitis progressing to chronic disease.

The serologic and viral profiles of 24 patients who presented with acute hepatitis B virus (HBV) infection were studied. Although in rare cases, HBV-DNA was detectable before hepatitis B surface antigen (HBsAg) and e antigen (HBeAg), in the majority the viral proteins appeared first. In acute hepatitis followed by recovery, as IgM anti-HBc (hepatitis B core antigen) titres rose, the level of HBV replication fell and serum transaminases became elevated. In patients progressing to chronic HBV infection, IgM anti-HBc titres rose early, viral replication was initially low but continued to rise as the serum transaminase levels became elevated. 7S IgM anti-HBc, although present in the phase of established chronic HBV infection, was not found in the early phase of the chronic infection. Thus this antibody appears to be a consequence of, rather than a causative factor in, chronic HBV infection.

DNA, Viral

Detection of serum HBV-DNA by molecular hybridisation. Correlation with HBeAg/anti-HBe status, racial origin, liver histology and hepatocellular carcinoma.

The relationship of the presence of hepatitis B virus (HBV) DNA in serum, a measure of HBV-replication, to HBeAg/anti-HBe status has been examined. In Northern Europe, there is a strong positive correlation between the presence of HBV-DNA and HBe antigenaemia and a negative correlation with the presence of anti-HBe. These associations are less marked in patients from Southern Europe, Africa, the Middle and Far East. When HBV-DNA is present in the serum of anti-HBe carriers, it is usually associated with the presence of severe liver disease or carcinoma. Forty percent of patients with hepatocellular carcinoma had evidence of continuing HBV replication.

Carcinoma, Hepatocellular

Thrice weekly lymphoblastoid interferon is effective in inhibiting hepatitis B virus replication.

Six patients with chronic hepatitis B virus (HBV)-induced liver disease were treated with human lymphoblastoid interferon. Daily, alternate day or thrice weekly regimens were employed in two, one and three patients respectively. Thrice weekly intra-muscular injections of 7.5 to 10 megaunits of interferon/m2 appeared to be as effective as daily injections in producing inhibition of HBV replication, were associated with fewer side effects and could be continued for up to 3 months. The effectiveness of this regimen in producing long-term inhibition of viral replication must now be determined.

Adult

Analysis of the molecular state of HBV-DNA in the liver and serum of patients with chronic hepatitis or primary liver cell carcinoma and the effect of therapy with adenine arabinoside.

The pattern of replicative intermediates seen in the liver of HBe antigen and antibody positive patients was determined. During the phase of HBe antigenaemia the 3.2 Kb species of HBV-DNA (complete HBV genome) is present in the liver but not in the serum. When HBe antigen to antibody seroconversion occurs, either spontaneously or during antiviral therapy, the 3.2 Kb and lower molecular weight intermediates disappear from the liver and the 3.2 Kb band appears transiently in the serum. Integrated HBV-DNA was found in one of 15 patients during the period of HBe antigenaemia and in three of seven patients in the HBe antibody positive phase of the chronic infection before detection of primary liver cell carcinoma. Integrated sequences were found in tumour tissue of two patients with primary liver cell carcinoma who were anti-HBc positive but were absent from the tissues of two patients developing primary liver cell carcinoma at a late stage of autoimmune liver disease. These studies suggest that integration of the HBV genome occurs rarely or in only a small proportion of hepatocytes during the early (HBe antigen positive) phase of infection in Caucasians. They also show that not all primary liver cell carcinomas necessarily contain HBV-DNA.

Adult

Failure to detect nucleic acid homology between some non-A, non-B viruses and hepatitis B virus DNA.

Some studies suggest that there is antigenic and nucleic acid homology of one type of non-A, non-B hepatitis virus with hepatitis B viral (HBV) proteins and DNA. Using molecular hybridization under high and low stringency conditions with high specific activity 32P-HBV DNA as a probe, serum and liver samples from patients and nonhuman primates infected with non-A, non-B hepatitis were examined. Our results provide no evidence of significant homology between the DNA extracted from serum and liver of patients and nonhuman primates infected with one type of non-A, non-B hepatitis and HBV DNA.

Animals

Acyclovir in hepatitis B antigen-positive chronic liver disease: inhibition of viral replication and transient renal impairment with iv bolus administration.

Six patients with hepatitis B virus (HBV) related chronic liver disease were treated with acyclovir, 5-15 mg/kg 8 hourly, given as an iv bolus or iv infusion over 1 h for up to 7 days. Two patients treated with 10 and 15 mg/kg 8 hourly showed a decrease in HBV-DNA polymerase and HBV-DNA when mean trough acyclovir plasma concentrations of 5.0 +/- 0.6 and 13.2 +/- 3.0 microM were attained. Inhibition of viral replication was not seen in patients treated with lower doses. Transient renal impairment was seen in two patients who received high dosage by the iv bolus mode of administration. This complication may be prevented by a high oral fluid intake or iv infusion of the drug over 1 h. Further study with acyclovir 15 mg/kg 8-hourly given as an iv infusion for longer periods is warranted.

Acyclovir

Defective hepatitis B virus DNA molecules detected in a stable integration pattern in a hepatoma cell line, and in induced tumours and derived cell lines.

Hepatitis B virus (HBV) DNA was found to be integrated into seven sites in the DNA of the PLC/PRF/5 hepatoma cell line as determined by digestion with the restriction endonuclease HindIII which does not cut through the viral genome. The integration pattern was stable in the cell line, in tumours induced in athymic mice by this line and in cell lines derived from such tumours. Syntheses of hepatitis B surface antigen and alphafoetoprotein were maintained in the induced tumours and derived cell lines. A defective HBV DNA molecule (approx. 2.8 kilobase pairs) appears to be integrated in a head-to-tail tandem arrangement and it is proposed that such defective molecules may be involved in the process of neoplastic transformation by HBV.

Animals

Relationship between HBV-specific DNA polymerase and HBe antigen/antibody system in chronic HBV infection: factors determining selection of patients and outcome of antiviral therapy.

The sera of 23% of HBe antigen positive patients with chronic hepatitis are HBV-DNA polymerase negative. These patients are probably undergoing spontaneous seroconversion from a state of high to low viral replication and do not require antiviral therapy. In chronic HBV infection rapid changes in viral replication as a result of antiviral therapy are reflected by changes in HBV-DNA and HBV-DNA polymerase but not by changes in HBe antigen concentrations. Disappearance of HBe antigen from serum may be delayed for 180 days after permanent inhibition of HBV replication with adenine arabinoside or its monophosphate derivative.

DNA-Directed DNA Polymerase