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Biomedical subjects

A Goudeau

Publications and source records attributed to A Goudeau.

At least 55 records · Page 3Linked to original sources
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↗
PubMed1994

Influence of human immunodeficiency virus infection on hepatitis delta virus superinfection in chronic HBsAg carriers.

It is generally agreed that hepatitis B virus (HBV) replication is reduced by hepatitis delta virus infection (HDV) and augmented by human immunodeficiency virus (HIV) infection. However, the precise nature of the interactions between HBV, HDV and HIV is controversial. The aim of this study was to evaluate the impact of HIV infection on HBV and HDV replication, and on histological scores during delta virus superinfection in HDV-positive, chronic carriers of hepatitis B surface antigen (HBsAg). We studied 38 men and six women, 15 of whom were HIV-positive and all of whom had at least one marker of HDV infection. Serum hepatitis B e antigen (HBeAg), HBV DNA, HDV RNA, anti-delta antigen antibodies (anti-HD) IgM, anti-HD IgG and hepatitis delta antigen (HDAg) were tested for in the serum and liver, respectively; anti-hepatitis C virus (HCV) antibodies were detected using a second-generation recombinant immunoblot assay. Histological specimens were scored blindly according to Knodell's classification for periportal and intralobular necrosis, portal inflammation and fibrosis. HBV DNA was detected more frequently in the HIV-positive patients than in those who were HIV-negative (25 vs 0%; P = 0.01), while markers of HDV replication (serum anti-HD IgM, serum HDV RNA and liver HDAg) were as frequent in the HIV-positive patients (69%, 40% and 50%, respectively) as in those who were HIV-negative (75%, 52% and 30%, respectively; P > 0.05). By contrast, 31% of the HIV-positive patients were serum HDAg-positive compared to only 6% of the HIV-negative patients (P = 0.001). HDV antigenaemia and anti-HD antibodies usually fluctuated in the HIV-positive patients during follow-up. The mean Knodell score was similar in the HIV-positive (11.5 +/- 3.2) and HIV-negative (10.7 +/- 2) subgroups, as was the mean semi-quantitative index of hepatic necrosis, inflammation and fibrosis. Our results provide evidence that in HDV-positive patients: (1) HIV infection counters the inhibitory effect of HDV superinfection on HBV replication; (2) serum anti-HD IgM. HDV RNA and liver HDAg are not more frequent in HIV-positive than in HIV-negative patients, suggesting that HIV infection has no effect on HDV replication (although the significance of the increased frequency of HD antigenaemia remains unclear); (3) the histological severity of liver disease is not influenced by HIV status.

Adult↗
PubMed1993

Use of nonradioactive DNA probes to identify a Campylobacter jejuni strain causing abortion.

A case of human abortion due to a Campylobacter infection is reported. Cultures revealed two morphologically different isolates with large and small colonies respectively. Using conventional methods of identification, the large colonies were identified as Campylobacter jejuni and the small colonies as Campylobacter coli. Dot blot hybridization and determination of rDNA restriction fragment patterns revealed that both colony types were the same strain of Campylobacter jejuni. This observation illustrates the need to use methods other than phenotypic methods when identifying strains of Campylobacter.

Abortion, Spontaneous↗
PubMed1993

Evaluation of a rapid latex test for direct detection of Streptococcus agalactiae in various obstetrical and gynaecological disorders.

Cervical samples collected during speculum examination in 413 women were tested for the presence of Streptococcus agalactiae by Gram staining, a new latex agglutination test and standard cultures. The results of each method are reported in correlation with the clinical circumstances of isolation. Gram stain and the latex agglutination test had a sensitivity of 30% and 78%, and a specificity of 89% and 98% respectively compared with culture. The sensitivity of the latex agglutination test was higher in cases of premature rupture of membranes (90%), presumed chorioamnionitis (86%), presumed post-partum endometritis (86%) and presumed salpingitis (87%). This latex agglutination test appears to be useful for identifying patients who are heavily colonized with Streptococcus agalactiae and are at a high risk of infection.

Evaluation Studies as Topic↗
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

Characterization of RNA-binding domains of hepatitis delta antigen.

Hepatitis delta antigen (HDAg), the only protein encoded by the hepatitis delta virus (HDV), binds specifically genomic and antigenomic strands of the HDV RNA. In a previous study, three recombinant HDAg subdomains were synthesized, covering residues 11 to 78, 79 to 163 and 164 to 212, and only the middle domain was shown to be responsible for the binding to HDV RNA. To investigate HDAg sequences involved in HDV RNA binding, we synthesized five peptides, 15 to 29 residues in length, and tested their ability to bind HDV RNA using a simple non-radioactive ELISA with digoxigenin-labelled HDV genomic or antigenomic RNA probes. The specificity of interactions was demonstrated by comparison with control peptides and non-HDV RNA probes, and with an inhibition assay using recombinant HDAg. The HDAg-binding domain found within the middle region (79 to 163) of HDAg was more finely mapped: it is located between residues 79 and 107. In addition, another domain (residues 2 to 27) of HDAg was also found to bind specifically to HDV RNA. These two peptides share sequence similarities at residues 2 to 10 and 97 to 107 with other RNA-binding domains.

Amino Acid Sequence↗
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↗
PubMed1993

Immune response to synthetic peptides of hepatitis delta antigen.

Hepatitis delta antigen (HDAg) is the only viral protein known to be expressed during hepatitis delta virus (HDV) infection. Detection of antibody to HDAg (anti-HD) is the usual method for diagnosis of HDV infection since viremia lasts only a few weeks. In an effort to identify the major epitopes recognized by humans during natural infection, four oligopeptides including residues 2 to 17 (SP1), 155 to 172 (SP2), 168 to 182 (SP3), and 189 to 211 (SP4) of the HDAg molecule were synthesized and probed by enzyme-linked immunosorbent assay with a panel of 80 serum specimens from 45 patients suffering from either HDV-hepatitis B virus coinfections (n = 17) or HDV superinfections (n = 28). Sera from infected patients recognized these relatively short peptides. Peptide SP2 was the most antigenic; 71% of serum specimens reacted. Antibody to SP2 was also the commonest in sera taken early in the course of the disease. Peptide SP2 corresponds to one of the two regions which is highly conserved between different isolates. Among the 63 serum specimens which scored anti-HD positive by a commercial assay, all but 3 reacted to at least one of the peptides (95% agreement). Peptide assays appeared to be significantly more sensitive than the commercial assay with native HDAg early in the course of HDV infection since 14 of 17 (82%) serum specimens which scored anti-HD negative in the commercial assay reacted to one or more peptides. All serum specimens giving one or more positive results with the various peptides were confirmed as being HDV positive by an inhibition assay with free peptide in solution. The immune response to HDAg peptides vared greatly between individuals. No specific reactivity profile could be assigned to those with either HDV-hepatitis B virus coinfections or HDV superinfections. Overall, HDAg peptides appeared to be convenient reagents in addition to native antigen for the development of new and improved diagnostic tests for HDV infection.

Amino Acid Sequence↗
PubMed1993

[Intraepithelial lesions of the cervix uteri and human papillomaviruses: comparative study of histological data and in situ hybridization. Apropos of a series of 77 cervical biopsies].

Seventy seven biopsy samples of cervical mucosa were tested for the presence of human papillomavirus (HPV) by immunohistochemistry and in situ hybridization. From the 38 samples identified as condyloma or cervical intraepithelial neoplasia (CIN), 31 were positive after in situ hybridization and 14 after immunochemical analysis. HPV 6 was found exclusively in condyloma acuminata (2 samples) whereas the HPV 16 probe essentially hybridized with high grade intraepithelial lesions (CIN II, CIN III). Low grade intraepithelial lesions (flat condyloma, CIN I) demonstrated a larger diversity of HPV types (HPV 16, 18, 31, 33). A close correlation was demonstrated between the histologic features of lesions and their HPV 6 or HPV 31 content but not for other HPV types. HPV 31 containing lesions showed a peculiar architecture with numerous, elongated papillae resulting in a spiked appearance.

Biopsy↗
PubMed1993

Prevalence and persistence of antibody titers to recombinant HIV-1 core and matrix proteins in HIV-1 infection.

Numerous studies have established the correlation between antibodies to the core protein p24 of HIV-1 and the progression of the acquired immunodeficiency syndrome. In this study, we analyzed the immune response to two recombinant gag proteins, p24 and p17, in order to evaluate their diagnostic or prognostic significance. Immune response to the immunodominant domain of the transmembrane glycoprotein gp41 was used as a reference. Sera collected from individuals from France and Burundi (Central Africa) at various CDC stages of HIV-1 infection were tested using three sandwich enzyme-linked immunoassays developed with a synthetic peptide corresponding to the immunodominant domain of gp41, SP gp41, or recombinant p24 and p17 cloned and expressed in Escherichia coli. These assays allowed detection of titer antibodies to the three cited antigens. Antibodies to SP gp41 were detected in every HIV-1-positive patient from France and Burundi, generally at a high and stable level. Results obtained with p24 confirmed the value of antibodies to p24 as a prognostic marker only in European and North American populations, since the African population had very high levels of these antibodies even at an advanced stage of the disease. They also confirmed that initial antibody response to p24 is more predictive of outcome than antibody titer change over time. Although antibodies to p17 decline during progression to AIDS, they are frequently absent in French patients at early, asymptomatic stages and therefore could not be used as a prognostic marker. In contrast, antibodies to p17 are significantly less common in African patients with AIDS when compared with symptomless HIV-1-infected African individuals.(ABSTRACT TRUNCATED AT 250 WORDS)

Acquired Immunodeficiency Syndrome↗
PubMed1993

Pseudomonas aeruginosa and cystic fibrosis: intrastrain variability in relation to intensity of immune response and clinical outcome.

Over periods exceeding two years, 63 Pseudomonas aeruginosa strains isolated from three children with cystic fibrosis were characterized using a 154 character auxanogram. Numerical analysis was carried out to establish intrastrain variability in relation to intensity of immune response and clinical outcome. For two patients, strains segregated in two distinct phenons. For the last patient, strains did not cluster. The degree of intrastrain variability during the infection was correlated with an increasing number of precipitins and with an unfavorable clinical outcome. This would suggest that strains which have a singular potential for antigenic variability are more likely to promote a host-bacteria conflict.

Bacterial Typing Techniques↗
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↗