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Biomedical subjects

C Buffet-Janvresse

Publications and source records attributed to C Buffet-Janvresse.

At least 19 recordsLinked to original sources
PubMed1999

[Does hepatitis c virus-related autoimmune thyroiditis exist? Reflections on a controlled study of 58 consecutive subjects].

PURPOSE: Interferon alpha treatment for virus C hepatitis may be responsible for autoimmune thyroiditis. Relationships between thyroiditis and virus C infection are still debated. The aim of this study was to evaluate the existence of this association. METHODS: The prevalence of autoimmune thyroiditis in 58 patients (35 male and 23 female patients, mean age 52.6) with untreated virus C hepatitis was compared to that of 56 alcoholic patients (41 male and 15 female patients, mean age 53.8). Autoimmune thyroiditis was defined as the association of abnormal TSH and an increase in antithyroid antibodies. RESULTS: We did not find any statistical difference in either autoimmune thyroiditis or antithyroid antibodies prevalences. CONCLUSION: Both our results and a literature review suggest that the few reported cases of related autoimmune thyroiditis and virus C infection are probably coincidental.

Adult↗
PubMed1999

Nucleic acid extraction from polluted estuarine water for detection of viruses and bacteria by PCR and RT-PCR analysis.

We describe an extraction protocol for genomic DNA and RNA of both viruses and bacteria from polluted estuary water. This procedure was adapted to the molecular study of microflora of estuarine water where bacteria and viruses are found free, forming low-density biofilms, or intimately associated with organo-mineral particles. The sensitivity of the method was determined with seeded samples for RT-PCR and PCR analysis of viruses (10 virions/mL), and bacteria (1 colony-forming unit mL). We report an example of molecular detection of both poliovirus and Salmonella in the Seine estuary (France) and an approach to studying their association with organo-mineral particles.

Biomarkers↗
PubMed1998

Detection of adenovirus in the waters of the Seine River estuary by nested-PCR.

Several systems for isolating viruses from environmental samples have been tested. The most promising method is based on genomic amplification. The authors attempted to detect adenovirus in nucleic-acid extracts from the Seine River estuary by a two-step amplification of a 220-bp segment of the conserved coding region of type 2 adenovirus hexon protein L3. The primers used in this study detected the most prevalent adenovirus serotypes in human disease in France, but not other virus strains or bacteria. The sensitivity of the nested polymerase chain reaction (PCR) amplification was estimated to be 10(2) copies of the adenovirus target sequence per ml of Seine River water. Nucleic-acid extracts from Seine River estuary waters were analysed and some tested positive for the presence of adenoviruses.

Adenoviridae↗
PubMed1997

Detection and genotyping of the hepatitis C RNA in tear fluid from patients with chronic hepatitis C.

Tear fluid from 51 patients with chronic hepatitis C virus (HCV) infection was analyzed for the presence of the hepatitis C RNA to assess the potential role of this fluid in virus transmission. HCV sequences were amplified from sera and tear fluids by nested polymerase chain reaction using primers from the 5' non coding region of the virus genome. Positive samples were genotyped by the LiPA procedures. HCV RNA was detected in 76.5% (39/51) of the sera and in 9.8% (5/51%) of the tear fluid samples. The presence of the RNA in the tear fluid was independent of the severity of the hepatitis and of the viral load as measured by the branched DNA assay. The genotypes of the tears and serum isolates were different for two patients. For another patient, the HCV RNA was positive in the tear sample but negative in the serum sample. These findings suggest that tear fluid may transmit HCV but the source of HCV RNA in this fluid needs to be better understood.

Chronic Disease↗
PubMed1997

GEMHEP multicenter quality control study of PCR detection of GB virus C/hepatitis G virus RNA in serum.

PCR is, to date, the only available tool for the detection of GB virus C (GBV-C) and hepatitis G virus (HGV) RNAs. Twenty-two French laboratories participated in a quality control study to assess the sensitivity and specificity of their procedures. The panel included 13 positive controls and 7 negative controls. The laboratories used either in-house PCR techniques adapted from the literature or partly standardized commercial tests. Three laboratories performed faultlessly with the entire panel. Most laboratories had excellent specificity (100% in 20 of 22 laboratories). Sensitivity was acceptable (85 to 100%) in 15 centers and insufficient (38 to 77%) in 7. As with nonstandardized in-house PCR, the commercial assays gave discrepant performances in different laboratories. These results suggest that laboratories willing to use PCR for detection of GBV-C/HGV RNA for research or diagnostic purposes should participate in multicenter quality control trials.

Flaviviridae↗
PubMed1995

Hepatitis C virus infection in an HIV-positive population in Normandy: antibodies, HCV RNA and genotype prevalence.

The prevalence and the characteristics of hepatitis C virus infection (HCV) in 161 HIV-positive patients were studied. HCV seroprevalence was determined by enzyme immunoassay and recombinant immunoblot assay (RIBA). Two different reverse transcriptase polymerase chain reaction (RT-PCR) methods were also used to test the HCV-seropositive samples and 50 EIA-negative sera used as controls. The RNA HCV-positive sera were genotyped by the LiPA procedure. Associations of HCV status with demographic characteristics and risk factors were assessed by chi 2 and Fisher's exact tests. The seroprevalence of HCV was 34.2% with a significant difference between blood and sexual exposure risk groups (60.6% vs. 13.6%, respectively; P < 0.0001). Thirty-six of the 55 anti-HCV-positive sera were also positive for HCV RNA, and PCR detected HCV RNA in 8 HCV-seronegative patients. Various RIBA profiles were found and all sera were positive for antibodies to the c33 protein. A proportion of sera had elevated levels of transaminase activity (37.2%), and abnormal liver function as associated with HCV infection. Forty-two samples were genotyped and five genotypes and subtypes of the HCV virus were detected. Genotype 1a was the most frequent in this cohort, although genotype 1b is generally more common in France. The majority (94.1%) of the patients with genotype 1a had a history of blood exposure, which may account for the difference.

Adolescent↗
PubMed1993

Herpes simplex hepatitis with chronic cholestasis in a newborn.

In the case of the central nervous system or hepatic involvement, the prognosis of neonatal herpes simplex infection remains poor, despite antiviral drugs, presumably effective if given early. We report the case of a neonate with herpes simplex hepatitis, where the course of the illness was unusual with chronic, ultimately fatal, cholestasis. The treatment was not effective, because its administration was delayed, because of high infant C reactive protein level and the absence of clinical maternal genital infection, and because it was interrupted due to misleading information: clinical improvement, negative viral tests and raised herpes IgG antibody titer.

Cholestasis↗
PubMed1992

HIV-1 sensitivity to zidovudine: a consensus culture technique validated by genotypic analysis of the reverse transcriptase.

In order to select and standardize a reliable assay for the analysis of sensitivity of HIV isolates to AZT, we have compared two culture methods. The first assay (Cell-Associated Isolate Sensitivity Assay: CAISA) quantified AZT-resistant HIV isolates by end-point dilution cultures of peripheral blood mononuclear cells (PBMCs) in the presence of various concentrations of AZT. In the second assay (Cell-Free Isolate Sensitivity Assay: CFISA), following a conventional isolation of HIV, dilutions of infected cell-free supernatants were cultivated with fresh normal donor PBMCs in the presence of increasing concentrations of AZT. Samples from 64 untreated and AZT-treated patients were studied by CAISA (41), CFISA (43) or both assays (20). The CFISA, which allows the determination of titration parameters with respect to various kinetics patterns of viral replication was selected, and some of the CFISA phenotypically characterized isolates were further studied by nucleotide sequence analysis of the reverse transcriptase gene. CFISA showed that isolates from untreated patients were susceptible to AZT while the frequency of resistance increased with the duration of therapy. Genotypic analysis of CFISA-resistant isolates exhibited mutations at crucial positions, particularly at residue 215. We consider CFISA as a consensus culture technique for longitudinal studies of isolates from patients receiving AZT or other analogs of nucleosides.

Cell-Free System↗
PubMed1987

Rapid decrease in the levels of the double-stranded RNA-dependent protein kinase during virus infections.

The double-stranded RNA-dependent protein kinase from human cells is a 68,000 molecular weight protein (p68 kinase), the level of which is enhanced significantly in cells treated with interferon. With a monoclonal antibody specific for p68 kinase, here we show the phosphorylation and steady-state levels of p68 kinase during virus infection. The p68 kinase is phosphorylated in interferon-treated cells during infection with encephalomyocarditis virus (EMCV), vesicular stomatitis virus (VSV), and vaccinia virus, thus indicating activation of p68 kinase during these virus infections, an essential step required for autophosphorylation of p68 kinase. However, in spite of this activation, the level of p68 kinase is rapidly decreased in virus-infected cells. The half-life of p68 kinase in uninfected cells is 6 to 7 hr, whereas in EMCV-infected cells it is 2 to 3 hr. This decrease in the level of p68 kinase is dependent on the multiplicity of virus infection and it seems to be specific since other cellular proteins as well as the activity of 2'-5'-oligoadenylate synthetase are not modified. Decreased levels of p68 kinase are also observed in cells infected with VSV and vaccinia virus. In the absence of virus infection, decreased levels of p68 kinase occur in cells following incubation with poly(I).poly(C).

2',5'-Oligoadenylate Synthetase↗
PubMed1987

[Mycoplasmas and pregnancy].

The pathogenic role of mycoplasms during pregnancy remains quite controverted, depending on the studies; for some it has an incidence on prematurity, delayed growth in utero and premature rupture of the membranes. The purpose of this study was, from a population of patients with term delivery, without any specific pathology, to verify the frequency of mothers carrying Mycoplasma Hominis or ureaplasma, and to determine the possible consequences on the newborn. A linear analysis of the evolution of the samples between D0 and D6 in the mother and the new born, shows that the presence of mycoplasms in the genital passages is as frequent in this non-risk population, and that the child may be contaminated about every other time; but this contamination appears to be very transient and without any consequences on the immediate neo-natal pathology. Systematic screening of genital mycoplasms in pregnant women does not permit, therefore, to select a group of exposed patients. In newborns who are contaminated, the risk of infection appears to be very low, but it would perhaps be desirable to study the long range future evolution of healthy carriers.

Female↗
PubMed1986

Enhanced level of double-stranded RNA-dependent protein kinase in peripheral blood mononuclear cells of patients with viral infections.

The protein kinase activity dependent on double-stranded RNA was assayed in extracts of peripheral blood mononuclear (PBM) cells from healthy volunteers and in patients with different types of virus infections. The protein kinase was assayed after one-step purification on an immunoaffinity column containing monoclonal antibody against the 68,000 Mr protein, a subunit of the protein kinase. In healthy individuals, the activity of the protein kinase remains constant. In contrast, the activity of the protein kinase is enhanced significantly in patients with viral infections and is decreased during the course of the disease in parallel with clinical ameliorations and reversal of clinical symptoms. There is a strong correlation between the enhanced levels of the protein kinase activity and another interferon-mediated enzyme, 2-5A synthetase. Both of these enzymes, therefore, could be used as markers to evaluate the state of the disease and recovery. In the different populations of lymphocytes, most of the protein kinase activity was found to be present in T and B lymphocytes, T lymphocytes showing a higher activity than B lymphocytes.

2',5'-Oligoadenylate Synthetase↗
PubMed1985

Enhancement of natural killer cell activity and 2-5A synthetase in operable breast cancer patients treated with polyadenylic; polyuridylic acid.

Treatment of operable breast cancer patients with a single injection of 60 mg poly(A); poly(U) (polyadenylic, polyuridylic acid) resulted in an enhancement of natural killer (NK) cell cytotoxicity against human myeloid K562 target cells. Furthermore, the level of 2-5A synthetase in peripheral blood lymphocytes of such patients was increased after the treatment. Both of these effects, measured 24 and 48 hours after the injection of poly(A); poly(U), were statistically significant compared to their respective levels before the treatment. These events, therefore, may be used as markers to monitor the immediate response of patients toward treatment with this synthetic double-stranded RNA.

2',5'-Oligoadenylate Synthetase↗
PubMed1985

Continuous production of interferon in normal mice: effect of anti-interferon globulin, sex, age, strain and environment on the levels of 2-5A synthetase and p67K kinase.

Two interferon-mediated enzymes, a 2-5A synthetase and a kinase that phosphorylates a 67 000 mol. wt. (p67K) protein were found at variable levels in different organs of mice. Among the different strains of mice included in this study, germ-free mice had the lowest levels of these enzymes. The levels of 2-5A synthetase and p67K kinase were enhanced significantly in all mice following treatment with mouse (alpha + beta) interferon. Here, we show that the presence of 2-5A synthetase and p67K kinase in different organs of normal mice (untreated) was due, at least in part, to a constant production of interferon under different physiological conditions. Accordingly, injection of normal mice with anti-mouse interferon (alpha + beta) globulin led to a significant decrease in the level of 2-5A synthetase and p67K kinase. In conventional mice (C3H/He), the level of both of these enzymes was higher in female than in male animals and was decreased with age or when such animals were reared isolated in a pathogen-free protected unit. The levels of 2-5A synthetase and p67K kinase were also decreased in normal mice following injection with a powerful antibiotic against a very wide spectrum of Gram-positive and Gram-negative bacteria. These results suggest that the production of interferon was induced continuously in normal mice. Such induction was mediated by both internal and external agents.

2',5'-Oligoadenylate Synthetase↗
PubMed1984

Enzyme markers for the presence of circulating interferon: 2-5A synthetase in blood lymphocytes and protein kinase in platelet-rich plasma.

The level of 2-5A synthetase in extracts of peripheral blood lymphocytes and a specific protein kinase activity in platelet-rich plasma were measured in normal individuals and in patients suffering from viral or bacterial infections. The level of these enzymes was tested at different times during the disease. The level of 2-5A synthetase and the protein kinase activity was enhanced by several-fold during viral and bacterial infections and decreased during the course of the disease in parallel with clinical ameliorations and reversal of clinical symptoms. Among the different types of infections studied, higher levels of these enzymes were observed during viral than bacterial infections. Our results emphasize the use of these enzymes as markers to evaluate the state of the disease and recovery. Furthermore, they provide evidence for the production of interferon during different types of infection.

2',5'-Oligoadenylate Synthetase↗