Search PubMed⌕ Search

Biomedical subjects

A Goudeau

Publications and source records attributed to A Goudeau.

At least 19 recordsLinked to original sources
PubMed1995

Detection and typing of human papillomaviruses by in situ hybridization with biotinylated oligonucleotide mixtures.

The value of biotinylated oligonucleotide probes for screening and typing by in situ hybridization of the most frequent genital human papillomavirus infections (HPVs 6, 11, 16, 18, 31, and 33) was assessed. Optimal hybridization conditions were defined on a panel of paraffin-embedded tissue sections previously characterized with HPV full genome probes. Mixtures of oligonucleotides rather than single oligonucleotides were used to improve sensitivity and specificity. All HPV-positive specimens were detected by the screening mixture with a sensitivity and specificity similar to that of full genome probes. Typing mixtures were highly specific for each HPV type. This study confirms the potential of oligonucleotide probes for detecting and typing HPV infections.

Biotin↗
PubMed1995

A simple procedure to generate chimeric Pr55gag virus-like particles expressing the principal neutralization domain of human immunodeficiency virus type 1.

The Pr55gag human immunodeficiency virus type 1 (HIV-1) precursor protein that is capable of auto-assembling was used as a carrier for a consensus sequence of the principal neutralization domain (PND) of the HIV-1 envelope. For this purpose, a modified HIV-1 gag gene with deletion of the sequence encoding a previously described p24 epitope (amino acids 196-228 of Pr55gag) was first obtained using PCR with degenerate primers, and then cloned. This deleted gag gene allowed in a second time the insertion of a synthetic oligonucleotide cassette encoding the North American/European consensus PND precisely in place of the p24 epitope. The chimeric gene was then inserted into a baculovirus transfer vector and expressed in insect cells. The construct formed 100-140 nm virus-like particles that were released into the extracellular medium. The use of a serum-free medium that supports growth of insect cells facilitated the downstream purification of the extracellular particles. The chimeric particles were recognized by monoclonal antibodies directed to V3 by Western blot but not by immune electron microscopy, suggesting that, although the inserted sequence was still antigenic it was not exposed at the surface of the particles. The results show the ability of Pr55gag to serve as a carrier for easy insertion, in a precisely defined region, of selected epitopes of gp120 surface envelope protein, and to still auto-assemble in virus-like particles. However, the data indicate that exposed epitopes of the mature p24 protein are not presented similarly in the Pr55 precursor, and therefore that different constructs with various insertions in different places must be generated. Such constructs offer an attractive approach for HIV vaccine development and will need evaluation for both antigenicity and immunogenicity.

Amino Acid Sequence↗
PubMed1995

Incidence and prevalence of hepatitis B in France.

Reporting of hepatitis B is not compulsory in France, but it is estimated that 8500-9000 acute cases and 100,000 hepatitis B infections occur every year. Seroprevalence studies have been carried out in selected populations. Every blood donation is screened for HBsAg, alanine aminotransferase elevation and anti-HBc antibody. Prevalence of HBsAg has declined from 13.9 positive donations in 1986 per 10,000 to 5.3 in 1991. In pregnant women, overall seroprevalence is estimated at 0.8-1%, which represents more than 5000 children born each year to carrier mothers. Screening of HBsAg for all women when six months pregnant is now compulsory. Heterosexual patients at STD clinics were shown to have a very high risk of being infected with hepatitis B virus, with a chronic carrier rate of 4-5%. In hospital employees before the introduction of vaccination, the overall incidence of hepatitis B was 100-300 acute cases per 100,000 employees per year. Risk varied according to exposure to blood; the highest incidence was found in nurses in dialysis wards. Vaccination against hepatitis B is now compulsory for all hospital and laboratory workers and medical and paramedical students. In preventive medicine consultants, routine medical check-up showed an overall HBV prevalence of 2.2% and a carrier rate of 0.3% in men and 0.1% in women. Immunization of all newborns and adolescents has recently been adopted in France, vaccination at school of adolescents aged 10-11 years being the main target.

Blood Donors↗
PubMed1995

Genetic diversity of Pseudomonas aeruginosa strains isolated from patients with cystic fibrosis revealed by restriction fragment length polymorphism of the rRNA gene region.

The restriction fragment length polymorphism patterns of rDNAs from Pseudomonas aeruginosa strains isolated from the respiratory tracts of patients suffering from cystic fibrosis were obtained to evaluate the genetic polymorphism of this population of strains. Eighty-seven P. aeruginosa strains isolated from 87 patients from diverse areas of France and the ATCC 10145 strain were examined. Four restriction enzymes were used: BamHI, ClaI, EcoRI, and PstI. Forty-nine strains (56%) were in the three most frequent ribotypes (ribotypes R1 to R3). In addition, hierarchical clustering analysis of the data showed that 71 of the 88 strains (81%) clustered at a distance of less than one-third of the greatest distance observed in the total population. This indicates that clinical isolates implicated in the pathology of cystic fibrosis present a low degree of heterogeneity of rRNA operons, in contrast to the heterogeneity of strains of P. aeruginosa isolated from patients with various other pathologies. This relative homogeneity of rRNA genes was observed independently of the clinical status of the patient and the colony morphology.

Adolescent↗
PubMed1995

Relapse of herpes simplex encephalitis.

We report five children who had recurrent central nervous system signs after conventional acyclovir therapy for herpes simplex encephalitis. Secondary exacerbation was characterized clinically by severe ballismic movement disorder in all five children, associated with fever, impairment of consciousness, and seizures. Biologic analysis in all children and magnetic resonance imaging and neuropathology studies of the brain in three cases were compatible with inflammatory reaction. In contrast, all viral cultures remained negative, herpes simplex virus antigen in one child and DNA tested by polymerase chain reaction in four children were undetectable in the first samples of cerebrospinal fluid during the relapse, suggesting a postinfectious, immune-mediated mechanism of relapse in these patients.

Acyclovir↗
PubMed1995

Hepatitis B, C, D, and E markers in rural equatorial African villages (Gabon).

Serologic markers of hepatitis B virus (HBV), including HBV DNA, and of hepatitis delta virus were measured in three villages in Gabon. Of 303 subjects studied, 19% were carriers of hepatitis B surface antigen (HBsAg); 8.5% of these had anti-delta antibodies. No difference among the three villages was observed. All HBV DNA carriers were children less than 11 years of age. In the 2-9-year-old group, 71% of the HBsAg-positive children tested were HBV DNA carriers. These results indicate that HBV prevalence is high in Gabon and emphasize the importance of horizontal transmission of HBV in Africa. Antibodies to hepatitis C virus, assessed in one of the three villages, were found with a prevalence of 35% with a second generation enzyme-linked immunosorbent assay (ELISA) and 24% with a third generation ELISA. None of 35 subjects tested for antibodies to hepatitis E virus was positive.

Adolescent↗
PubMed1994

Serum alanine aminotransferase measurement as a guide to selective testing for hepatitis C during medical checkup.

The efficiency of elevated serum alanine aminotransferase values for selecting subjects to be tested for hepatitis B or C infections in a large French population undergoing a medical checkup was investigated. For 5 consecutive weeks, serum alanine aminotransferase values were controlled in 9044 subjects; 308 subjects (202 males) were selected with alanine aminotransferase levels 1.2-fold above the normal value (58 iu/l for men, 34 iu/l for women). For each selected case, an age- and sex-cross-matched control was included. Of the 308 subjects with elevated alanine aminotransferase values, one was HBsAg positive and 15 (seven males) were anti-HCV positive. All anti-HCV sera tested by enzyme immunoassay were also positive by three immunoblots and 11/15 (73%) were HCV-RNA positive by reverse transcription-polymerase chain reaction. Of the 308 control subjects, two were HBsAg positive and four (two males) were weakly anti-HCV positive by enzyme immunoassay. Only one weakly anti-HCV positive serum was reactive by one immunoblot and all were HCV-RNA negative. This study shows the usefulness of alanine aminotransferase screening to detect hepatitis C virus infection in the general French population. Many of the anti-HCV positive subjects detected in this study were not aware of their hepatitis C virus seropositivity (12/15) or that they were viremic (11/15). Use of this low-cost assay will considerably reduce the number of subjects to be tested for hepatitis C virus serological status and therefore the cost. It may make possible the investigation of large populations by setting up public health programs to detect and treat hepatitis C virus. Hepatitis C virus infected subjects detected in these programs could benefit from medical follow up, including antiviral therapy.

Adolescent↗
PubMed1993

High antigenic cross-reactivity of the V3 consensus sequences of HIV-1 gp120.

The principal neutralization determinant (PND) of the human immunodeficiency virus type 1 (HIV-1) is located within the variable V3 region of the external envelope protein gp120. Although it is recognized that V3 sequences induce antibody response with restricted neutralization activity in vitro, we observed that the V3 consensus sequences representing North American/European and African isolates were highly cross-reactive, binding 94 and 77%, respectively, of sera collected from HIV-1 individuals originating from various parts of the world. Even HIV-1-positive sera from some East African residents, infected by strains whose V3 loop sequences are undoubtedly distinct from the North American/European consensus V3 loop sequence, reacted better to the V3 North American/European consensus peptide than to African-specific V3 sequences. Results indicate that the V3 consensus sequences represent the best candidates for optimal cross-reactivity with a wide variety of strains. Furthermore, using immunoassays for antibodies to prototype-specific V3 sequences, it is shown that HIV-1 strains related to the MN group are prevalent in West Africa, indicating either a West African origin of the MN-related viruses or more probably an introduction of this group of viruses through European/North American contacts.

Africa↗
PubMed1993

Adherence to human cells of a cryptic Haemophilus genospecies responsible for genital and neonatal infections.

Haemophilus strains usually identified as Haemophilus influenzae biotype IV belonging to a cryptic genospecies are responsible for genital and neonatal infections. As a first approach to identifying the bacterial factors involved in the pathogenesis of these unusual diseases, we studied the piliation, adherence, and invasion properties of 17 strains assigned to this cryptic genospecies. Twelve strains spontaneously displayed abundant peritrichous piliation, and two strains expressed peritrichous pili after enrichment procedures. For virtually all strains, piliation correlated with adhesion to cultured HeLa cells of genital origin and to a lesser extent with adhesion to HEp-2 cells of laryngeal origin. A variation in the adherence properties of the various strains was observed: all piliated strains except one adhered to 50 to 100% of HeLa cells, with a mean number of bacteria per cell varying from 4 to 50. Adherence was not dependent on the state of growth for most strains, was more pronounced with HeLa cells than with HEp-2 cells for 10 of the 12 highly adherent strains, was time and inoculum dependent, and was not followed by significant invasion of cells. Most of the strains belonging to this unusual Haemophilus clone possess adhesins that do not recognize erythrocyte receptors, since agglutination of human erythrocytes was observed with only 3 of the 14 piliated strains.

Bacterial Adhesion↗
PubMed1993

Genetic characterization of a cryptic genospecies of Haemophilus causing urogenital and neonatal infections.

In recent years, reports originating from several areas of the world have identified biotype IV strains of Haemophilus influenzae as a cause of serious urogenital, neonatal, and mother-infant infections. Preliminary analysis of a sample of biotype IV isolates found evidence for a cryptic genospecies of Haemophilus (R. Quentin, A. Goudeau, R. J. Wallace, Jr., A. L. Smith, R. K. Selander, and J. M. Musser. J. Gen. Microbiol. 136:1203-1209, 1990). Eighteen biotype IV strains assigned to the cryptic genospecies were further characterized by their rDNA restriction fragment length polymorphism patterns and genomic DNA-DNA hybridization. Isolates of the cryptic genospecies have distinctive rDNA restriction fragment length polymorphisms that differ from those of Haemophilus haemolyticus and H. influenzae. Genomic hybridization studies show that these organisms are allied with H. influenzae and H. haemolyticus and suggest a distant trifurcation of H. influenzae, H. haemolyticus, and the cryptic genospecies.

Adult↗
PubMed1993

Prevalence and significance of hepatitis C virus (HCV) viremia in HCV antibody-positive subjects from various populations.

Hepatitis C virus (HCV) infection is currently assessed by detection of antibodies to HCV with immunoassays. However, in the absence of an in vitro system to isolate the virus, or an immunoassay to identify HCV antigen in blood, an ongoing acute or chronic HCV infection can be diagnosed only by detection of HCV RNA by polymerase chain reaction. We used a reverse transcription-nested polymerase chain reaction to detect an HCV 5' noncoding viral RNA sequence in serum specimens collected from anti-HCV-positive individuals belonging to different risk groups and compared the results with those obtained with a prototype recombinant immunoblot assay (Chiron HCV SIA prototype recombinant immunoblot assay [RIBA]) containing four different viral peptides (c22, c33c, c100, and NS5). The prevalence of HCV viremia ranged from 25.9% in HCV antibody-positive blood donors to 92% in HCV antibody-positive hemophiliacs. Elevated alanine aminotransferase values in HCV antibody-positive patients were clearly associated with viremia. Ninety-six percent of HCV RNA-positive patients reacted to two viral antigens or more, compared with only 64% of HCV RNA-negative patients. Contrary to previous reports, HCV viremia was not associated with either the presence or the absence of a particular antibody specificity. The newly introduced NS5 peptide did not improve the sensitivity or specificity of the RIBA. Although 20% of the patients in our study whose sera reacted to all of the antigens were HCV RNA negative, the positive predictive value of a RIBA considered positive by the manufacturer (two or more bands), was rather high (78%) and may allow suspicion of viremia in EIA2 enzyme-linked immunosorbent assay-positive patients.

Alanine Transaminase↗
PubMed1992

Persistent delta antigenaemia in chronic delta hepatitis and its relation with human immunodeficiency virus infection.

The prevalence of persistent hepatitis delta (HD) antigenaemia and associated factors in patients with chronic infection with the hepatitis delta virus (HDV) were investigated. Among 157 consecutive patients known to be carriers of hepatitis B surface antigen (HBsAg), 36 (23%) had one serum marker of HDV infection (anti-HD and/or HDAg). Nine of the patients with an HDV marker were HDAg positive, including three who were anti-HD negative. A follow-up over a mean period of 13 months showed that five of five patients had a persistent HD antigenaemia. This serological profile was associated with the presence of antibody to the human immunodeficiency virus (anti-HIV) (P < 0.01), serum HIV antigen (HIVAg) (P < 0.2), and the female sex (P < 0.05). Persistent HD antigenaemia could be the consequence of the suppression of T cell cytotoxic activity against hepatocytes expressing HDAg, a lower humoral response, and/or hormonal factors.

Adult↗
PubMed1992

Evaluation of four commercial methods for identification and biotyping of genital and neonatal strains of Haemophilus species.

Four commercial methods for identification of Haemophilus species were evaluated in comparison to conventional methods using 188 genital and neonatal Haemophilus strains. In the case of discrepancies between results obtained by the different methods, DNA-DNA hybridization was performed. The four commercial systems and conventional methods showed excellent correlation of results in 167 strains (88%). DNA-DNA hybridization was performed in 8 strains with discrepant identification results and 13 strains with discrepant biotyping results. In 15 cases discrepancies could be explained by the fact that the strains belonged to a newly recognised species of Haemophilus.

DNA, Bacterial↗
PubMed1992

Infection due to hepatitis delta virus in Africa: report from Senegal and review.

A review of the literature shows strong variations in the prevalence of hepatitis delta virus (HDV) among Africans seropositive for hepatitis B surface antigen (HBsAg). In Senegal, West Africa, prevalence of antibodies to HDV among asymptomatic HBsAg carriers appears to be linked to regional and/or socioeconomic factors. Antibodies to HDV were found in 22 (47%) of 47 HBsAg-seropositive patients with liver disease who were hospitalized in the main hospital of Dakar and in 4% to 44% of asymptomatic HBsAg carriers. Eight (36%) of 22 patients with liver disease were seropositive for IgM antibodies to HDV, whereas none of 18 asymptomatic subjects were seropositive (P less than .01). According to studies conducted in Europe and the United States, the presence of this marker may constitute support for the argument that HDV plays a role in the development of HBsAg-associated liver diseases in Senegal and, presumably, within the African continent.

Adult↗
PubMed1992

Acute measles encephalitis of the delayed type: neuroradiological and immunological findings.

A case of delayed acute measles encephalitis in an immunosuppressed child is reported. Detailed immunological studies have shown defective humoral immunity (defective IgA, IgG2 and IgG3) and decreased natural killer activity. Neuroradiological examination by magnetic resonance imaging revealed several high signal lesions on T2-weighted images in the gray matter without clinical or pathological correlation. The implications of these findings are discussed.

Antigens, Viral↗