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C Brechot

Publications and source records attributed to C Brechot.

At least 127 records · Page 7Linked to original sources
PubMed1988

Differential expression of insulin-like growth factor II mRNA in human primary liver cancers, benign liver tumors, and liver cirrhosis.

We investigated insulin-like growth factor II (IGF-II) mRNA in three groups of human liver samples including primary liver cancers, benign liver tumors and cirrhosis; indeed these pathological conditions would allow us to distinguish between different steps in liver carcinogenesis. A 40- to 100-fold increase in IGF-II mRNA was shown in 9/40 of the liver cancer samples as compared to normal adult liver. RNA blot analysis using both IGF-II cDNA and oligonucleotide probes showed the reexpression of two fetal (6 and 5 kilobases) IGF-II transcripts in primary liver cancers and in some cirrhotic adjacent tissues; these included all the samples with enhanced IGF-II expression. By contrast the adult (5.3 kilobases) IGF-II transcript was identified in most of the benign liver tumors and liver cirrhosis; in addition, in some of these samples, the 5-kilobase fetal transcript was also detected. The increase of IGF-II mRNA in some liver cancers is consistent with an autocrine mechanism conferring a selective growth advantage to tumorous liver cells. Furthermore, these results indicate a differential expression of IGF-II transcripts in nonmalignant hepatocyte proliferation (benign liver tumors and cirrhosis) as compared to liver cancer. Finally this study suggests that, in liver cirrhosis and in some benign liver tumors, premalignant proliferative states might be identified by the presence of IGF-II fetal transcripts.

Fetus↗
PubMed1988

Detection of HIV1 DNA in infants and children by means of the polymerase chain reaction.

The polymerase chain reaction (PCR) assay was used to investigate the possibility of HIV1 DNA detection in uncultured peripheral blood mononuclear cells from newborn infants and children of HIV-infected mothers. HIV1 DNA sequences were detected in mononuclear cells of six of fourteen symptom-free newborn infants of seropositive mothers. Only one of these infants had detectable HIV antigenaemia. In addition, HIV1 DNA was identified in the mononuclear cells of five of ten children (2-5 years old) of infected mothers who had become seronegative 12-15 months after birth; among these, four children had only mild clinical features related to HIV infection, while the other had none. HIV1 DNA was shown in all of eight seropositive children with HIV infection and none of fifteen normal seronegative controls. The PCR assay thus provides an early and direct identification of HIV infection in newborn infants and seronegative children born to infected mothers.

Child↗
PubMed1988

Detection of mononuclear cells expressing hepatitis B virus in peripheral blood from HBsAg positive and negative patients by in situ hybridisation.

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.

Adolescent↗
PubMed1988

Fulminant hepatitis due to reactivation of chronic hepatitis B virus infection after allogeneic bone marrow transplantation.

A case of hepatitis B reactivation following bone-marrow transplantation for leukemia in a previously healthy HBsAg carrier is reported. A number of changes in HBV serum markers were contemporary to the acute episode. All of them (increase of HBsAg concentration, conversion from anti-HBe to HBeAg, appearance of anti-HBc IgM and of serum HBV-DNA) were suggestive of a "switching-on" of viral replication. Institution of corticosteroid treatment at the onset of the acute phase did not prevent the fatal outcome.

Adult↗
PubMed1988

Regional mapping to 4q32.1 by in situ hybridization of a DNA domain rearranged in human liver cancer.

Recently, a unique cellular DNA segment, representing the normal allele counterpart of hepatitis B virus integration site, has been isolated. It has allowed the identification of a cellular domain in which rearrangements occur in approximately 10% of primary liver tumours. We here report on the assignment of this probe, D4S112, by in situ hybridization to band 4q32.1.

Carcinoma, Hepatocellular↗
PubMed1988

Hepatitis B virus and hepatitis B-related viral infection in renal transplant recipients. A prospective study of 90 patients.

Hepatitis B virus (HBV) infection may induce severe hepatitis and affect long-term survival of kidney transplant recipients. Persistent viral infection has been shown to occur despite the absence of usual serologic markers. The liver and serum HBV deoxyribonucleic acid (DNA) status of 90 patients were studied prospectively; recently transplanted patients, both hepatitis B virus surface antigen (HBsAg)-positive and negative, with and without liver disease, were investigated with HBV serology, serum HBV DNA, and liver histology. Thirty-four patients had detectable HBsAg, and 21 had viral multiplication at the time of transplantation. Serial HBV DNA determinations performed in 57 of 90 patients disclosed (a) reactivation of HBV replication in 11 of 12 HBsAg-positive patients, (b) increase of viral replication when positive on the initial sample in 6 of 11 patients, and (c) development of HBV replication in 7 of 35 of the HBsAg-negative patients. Moreover, liver HBV DNA studies showed a statistical correlation between the presence of integrated liver HBV DNA and chronic hepatitis in HBsAg-negative patients. This study demonstrates prospectively the significant association of HBsAg-positive as well as HBsAg-negative HBV infection with chronic hepatitis and suggests that immunosuppressive therapy may enhance the viral replication in both HBsAg-positive and negative subjects.

Adult↗
PubMed1988

Hepatitis B virus infection of adult human hepatocytes cultured in the presence of dimethyl sulfoxide.

We investigated the possibility of infecting normal adult human hepatocytes maintained in pure cultures or in cocultures with hepatitis B virus (HBV). Several assays with different infectious sera and hepatocyte populations from various donors identified only limited HBV replication, with significant variations from one cell preparation to another. The addition of 1.5% dimethyl sulfoxide to the culture medium markedly enhanced the infection process. Indeed, hepatitis B e antigen secretion, the appearance of both HBV DNA replicative forms and major HBV transcripts, and the release of complete HBV particles into the medium were demonstrated. It is possible that the significant increase in intracellular HBV DNA in dimethyl sulfoxide-treated cells was related to enhanced adsorption of the virus. When viral particles produced by a transfected HepG2 cell line were used to infect normal hepatocytes, the same results were obtained. In addition, comparative assays with hepatocytes from three different donors showed that although high amounts of intracellular viral DNA were found in all cases, viral replicative intermediates were visualized in only one case. These findings suggest that this HBV-producing cell line could serve as a reproducible source of infectious virus and that primary culturing of human hepatocytes represents a unique tool for analyzing intracellular regulating factors which, in addition to the penetration step, modulate HBV replication.

Cell Survival↗
PubMed1987

Genomic diversity of Zairian HIV isolates: biological characteristics and clinical manifestation of HIV infection.

We describe here several African isolates of HIV, compare them to U.S.-European prototype isolates and to each other, correlate the number of isolates with serological results, and provide insights into the disease spectrum associated with HIV infection in Africa. Three of 25 healthy Zairian donors and 54 of 87 Zairian patients selected for specific pathology and hospitalized in the internal medicine department of the University Clinic of Kinshasa, Zaire, were HIV positive over a six month period in 1985 either by serum antibody (42 cases) or virus isolation (40 cases). The virus positive cases showed a decrease in number of T4 cells and interleukin-2 (IL2) production by mononuclear cells. Restriction endonuclease analysis of HIV sequences from these isolates showed that genomic diversity is also observed in the Zairian isolates but closely related viruses could also be found, similar to the spectrum of diversity among isolates obtained from the U.S. and Europe. A number of isolates (12 of 40) were obtained from serum antibody negative adults. These results are difficult to explain by viral antigenic diversity alone since hybridization with a HTLV-III-B (clone BH10) probe under stringent conditions indicated an overall high degree of relatedness. Rather, these results indicate that some African HIV infected patients fail to make detectable antibodies to HIV or the antibodies were bound in immune complexes not detectable by current techniques.

Acquired Immunodeficiency Syndrome↗
PubMed1987

Monoclonal anti-HBs antibodies radioimmunoassay and serum HBV-DNA hybridization as diagnostic tools of HBV infection: relative prevalence among HBsAg-negative alcoholics, patients with chronic hepatitis or hepatocellular carcinomas and blood donors.

Anti-HBs monoclonal antibodies radioimmunoassay (m-RIA) and HBV-DNA hybridization techniques were used to detect HBs antigen (HBsAg)--associated determinants (evidence of HBV on-going infection) and HBV-DNA sequences (evidence of viral multiplication) in the serum samples of 479 patients who were HBsAg negative by standard solid-phase radioimmunoassay. They included 128 alcoholics, 104 patients with chronic hepatitis, fifty-four with an hepatocellular carcinoma, 100 with coagulation disorders and ninety-three blood donors. The aim of this study was the comparison in these populations of the prevalence of the various HBV markers. m-RIA detected HBsAg-associated determinants in 1% of blood donors, 3% of coagulation disorders, 3.1% of the alcoholics, 21.1% of chronic hepatitis and 16.6% of hepatocellular carcinoma; hybridization identified HBV-DNA sequences in 0.9%, 2.2%, 10.9%, 9.6% and 5.5% of these cases, respectively. The combined prevalence of both markers of an on-going HBV infection (with or without viral multiplication) was 14.16%, 26.9% and 22.2% in the latter groups, respectively, as compared with only 3% in patients with coagulation disorders and 2.1% of blood donors. These results confirm the frequency of HBV or HBV-related virus infection in alcoholics, in chronic hepatitis and hepatocellular carcinomas, despite the absence of HBsAg by standard RIA (or even of any other usual marker); this gives further evidence for variations in the expression of HBV infection. A high and quite similar prevalence of usual serum markers and hybridization results was observed in the alcoholics and in the patients with chronic hepatitis.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1986

[Hepatitis B virus DNA as a marker of viral multiplication: comparison with HBe antigen and anti-HBe antibody].

We have used D A-DNA hybridization techniques with a spot test procedure for the detection of hepatitis B virus (HBV) DNA in the serum of 156 HBsAg positive patients with chronic active hepatitis and 75 asymptomatic chronic carriers of the virus. The results were compared with those of HBeAg and anti HBe tests. HBV DNA was detected in the serum of 107 of the 132 (81%) HBeAg positive and 6 of the 24 (25%) anti HBe positive patients with chronic hepatitis. A semi-quantitative estimation of the amount of viral particles showed a marked heterogeneity among the positive sera. HBV DNA was not detected in the serum of 25 patients despite HBeAg positivity: serial samples were available for 13 of these subjects and HBe became undetectable in 9 cases after 6 to 12 months. Among the 75 anti HBe positives asymptomatic carriers HBV DNA was detected in 3 (4%). It appears that HBV DNA detection in the serum is a much more sensitive and direct assay for HBV multiplication than the HBeAg and anti HBe tests.

Carrier State↗
PubMed1986

Monoclonal antibody recognizing pre-S(2) epitope of hepatitis B virus: characterization of pre-S(2) epitope and anti-pre-S(2) antibody.

A hybrid cell line producing monoclonal antibodies recognizing an epitope encoded by the pre-(S)2 region of hepatitis B virus (HBV) genome was obtained by fusion of mouse myeloma cells with lymphocytes from mice immunized with HBV. The monoclonal antibody Mo-F124 secreted from the hybrid line reacted with the pre-S(2) epitope expressed on the surface of both viral and recombinant HBsAg particles--pre-S(2) and S gene product--localised on 34 kD glycoprotein of the viral envelope. The pre-S(2) epitope was sensitive to digestion with V8 protease from Staphylococcus aureus. The enzyme abolished reactivity with Mo-F124 and polymerized human serum albumin (pHSA) binding activity of recombinant particles. Mo-F124 antibody was used to develop highly sensitive radioimmunoassays for determination of pre-S(2) epitope and anti-pre-S(2) antibody in sera of hepatitis B patients. Detection of a pre-S(2) epitope by the monoclonal antibody-based assay in the early phase of acute HBV infection correlated well with the presence of markers of active viral replication (HBeAg, HBV DNA). The appearance of anti-pre-S(2) antibody, usually in the third month after onset of symptoms, was followed by elimination of circulating HBsAg and seroconversion to anti-HBs in all tested cases of uncomplicated acute hepatitis followed by recovery. Anti-pre-S(2) response was not observed in patients with chronic hepatitis B or acute HBV infection progressing to chronic disease. The observed correlation of anti-pre-S(2) response with recovery suggests that the pre-S(2) epitope may represent one of the epitopes inducing antibodies that neutralize the hepatitis B virus.

Acute Disease↗
PubMed1986

Hepatitis B vaccination in chronic alcoholics.

Given the possible role of hepatitis B virus in the occurrence of hepatocellular carcinoma and the high prevalence of HBV infection in alcoholics, we attempted to prevent HBV infection in alcoholic patients with or without cirrhosis. Among 32 cirrhosis, 20 received three injections of hepatitis B vaccine at monthly intervals and 12 had a 4th injection one month later. Effectiveness was evaluated on the anti-HBs titer at the 6th month; it did not differ between the 3- and 4-injection groups. Two patients were good responders (anti-HBs greater than 300 mU/ml), 14 had a low response (m-30 mU/ml at the peak) and 16 (50%) had no detectable anti-HBs. All alcoholics without cirrhosis were given 4 injections; all had detectable anti-HBs but their mean antibody response was 97.7 +/- 4 SD. No obvious statistical difference in the response to the vaccine was noted on the basis of sex or age, or on the discontinuation or not of alcohol intake. Deficient antibody response to vaccines has not previously been demonstrated in patients with cirrhosis or in alcoholics. It remains to be determined whether this response is specific of HBV and how it could be related to the role of HBV in the occurrence of liver alterations in alcoholics.

Adult↗
PubMed1986

Identification and transmission of hepatitis B virus-related variants.

We have identified long-incubation viral agents that share epitopes with hepatitis B virus (HBV). During chimpanzee infectivity studies, these agents may be recognized in the liver since they possess complementary nucleic acid sequences with HBV DNA; the genomic size was found to be 3.2 kilobases, identical to that of HBV. Liver injury was produced and there was antigen expression in hepatocytes. Chimpanzees were not protected by prior immunization with hepatitis B surface antigen; conversely, they were still susceptible to HBV after recovery from infection with such agents. These findings suggest that these hepatitis B virus-related variants appear to be immunologically distinct from HBV.

Animals↗
PubMed1985

Hepatitis B virus DNA sequences in lymphoid cells from patients with AIDS and AIDS-related complex.

A lymphotropic virus HTLV-III/LAV was recently identified as the etiologic agent of the acquired immune deficiency syndrome (AIDS). In a study of concomitant hepatitis B infections in patients with AIDS or the AIDS-related complex, DNA sequences of hepatitis B virus (HBV) were found in fresh and cultured lymphocytes from patients with AIDS even in the absence of conventional HBV serological markers. Furthermore, the restriction DNA pattern was consistent with the integration of the viral DNA. These results should prompt additional studies to reevaluate a possible role of HBV as a cofactor in AIDS in addition to the HTLV-III/LAV causal agent.

Acquired Immunodeficiency Syndrome↗
PubMed1985

Presence of HBV DNA in spermatozoa: a possible vertical transmission of HBV via the germ line.

Using molecular hybridization we studied the presence and state of HBV DNA in sperm samples obtained from 17 patients with HBV infection (eight HBsAg chronic carrier, nine acute hepatitis B). Presence of HBV DNA was detected in three samples of seminal fluid from three patients with acute hepatitis. Restriction enzyme patterns of cellular DNA were consistent with presence of integrated HBV DNA sequences in spermatozoa from two of these three patients. The results indicate that HBV DNA may be present in the semen, at least during the acute phase of HBV infection. The presence of HBV DNA in seminal fluid confirms the possibility of venereal transmission. The presence of integrated sequences in spermatozoa suggests the possibility of true vertical transmission of HBV via the germ line.

DNA, Viral↗