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Biomedical subjects

E Dussaix

Publications and source records attributed to E Dussaix.

At least 55 records · Page 3Linked to original sources
PubMed1996

Assessment of a standardized reverse-transcriptase PCR assay for quantifying HIV-1 RNA in plasma and serum.

The analytical variability of the new commercially available Reverse Transcriptase-Polymerase Chain Reaction (RT-PCR) assay, Amplicor HIV-1 Monitor, has been assessed to establish criteria for assessing the significance of HIV-1 RNA level measurements. Estimations of the standard deviations (SD) of log-copies in inter-assay (mean 0.09 log) and in inter-laboratory (mean 0.14 log) reproducibility experiments demonstrated that the assay can discriminate with 95% confidence between 3-fold (inter-assay) and 5-fold differences (inter-laboratory). The inter-lot reproducibility (mean 0.10 log) was similar to the inter-assay reproducibility. The HIV-1 RNA concentrations measured in plasma collected in potassium EDTA anticoagulant were slightly higher than those measured in plasma collected in sodium citrate. The HIV-1 RNA concentrations measured in sera were about 50% of the HIV-1 RNA concentrations measured in paired plasma samples. However, there was a strong correlation between these two measurements (P < 0.0001). The assay was used to measure viral RNA in the plasma of 50 HIV-1 positive individuals at different stages of infection. All the individuals had detectable HIV-1 RNA (300-957000 copies/ml). There was no correlation between HIV-1 RNA and Immune Complex Dissociated (ICD) p24 antigen, but HIV-1 RNA was correlated with CD4+ cell counts (P < 0.0001) and the clinical stage (P = 0.0042), with higher HIV-1 RNA concentrations in patients with a more advanced stage of the disease. The significant association of HIV-1 RNA with major markers of HIV infection and the reliability of this sensitive, easy-to-use RT-PCR assay indicate its suitability for use in clinical trials and suggest that this assay is appropriate for routine clinical applications.

Adult↗
PubMed1996

Enterovirus in sudden unexpected deaths in infants.

BACKGROUND: Conventional approaches to virus detection failed to provide convincing evidence of a viral etiology in sudden unexplained deaths in infants (SUDI). Many viruses may not have been detected by the routinely used methods; among them enteroviruses (EV) have seldom been found in SUDI. METHODS: In this study EV were sought directly in stools, in pharyngeal and tracheal samples and in myocardial and lung tissues, by using a nested PCR; they were also sought indirectly by detecting IgM antibodies with a new capture immunoassay. Twenty-four SUDI cases were divided into two groups: Group I, certainly associated with; or Group II, not associated with clinical, biologic or histologic signs of viral infection. RESULTS: EV were found in stools but their prevalence was not significantly different between Group I and Group II (20 and 22.2%, respectively). On the contrary EV were detected in respiratory tract and/or lung samples in 53.8% of infants of Group I and in none of Group II. Anti-EV IgM antibodies were detected in 55.5% of infants of Group I and in none of Group II. CONCLUSIONS: These results indicate that EV infection may be specifically associated with the subgroup of SUDI with viral signs, raising the question of its role in this condition.

Base Sequence↗
PubMed1996

Multicenter evaluating of a commercially available PCR assay for diagnosing enterovirus infection in a panel of cerebrospinal fluid specimens.

Thirteen laboratories participated in blind tests of a panel of 20 coded cerebrospinal fluid specimens (7 uninfected samples, 3 samples infected with 1 50% tissue culture infective dose [TCID50]/0.1 ml [nonenterovirus strains], and 10 samples infected with 10, 1, or 0.1 TCID50/0.1 ml [three different enterovirus serotypes]) on the Amplicor enterovirus PCR assay (Roche Diagnostic Systems). The panel was also evaluated by in-house PCR (two nested-PCR and three one-step PCR assay) or tissue culture (eight laboratories). The viral load was shown to influence greatly the sensitivity of the assay. The average sensitivity of the Amplicor test ranged from 67 to 98% for viral titers of 1 to 10 TCID50/0.1 ml, respectively; titers of 0.1 TCID50/0.1 ml resulted in a sensitivity of only 16%. The overall specificity of the Amplicor test was 98%. The Amplicor assay compared favorably to the five in-house PCR tests (no significant difference in either sensitivity or specificity) and was much more sensitive than tissue culture (P < 0.001), even for high viral loads. It was easy to perform, rapid (about 6 h), well-standardized, and appeared to be suitable for the diagnosis of enterovirus meningitis on a routine basis in laboratories trained in molecular biology techniques.

Base Sequence↗
PubMed1996

CMV-IGG avidity and CMV-IGM concentration in both immunocompromised and immunocompetent patients.

Both CMV-specific IgG avidity index (AI) and CMV-specific IgM concentration were studied in different stages of CMV infection in both immunocompromised and immunocompetent patients. In these two groups (61 patients), a past CMV infection was associated with a mean AI constantly higher than 80%, just as the secondary infections observed in 18 immunocompromised patients (mean AI = 92%). In the 5 immunocompromised patients with primary CMV infection, the maturation of CMV IgG activity was delayed for at least one year; in contrast, the CMV-specific IgM concentration was persistently high up to 12 months. In additions, the 10 pediatric liver recipients who developed a primary CMV infection despite the administration of CMV specific immunoglobulins during the first two months post-transplantation had initially a high AI for anti-CMV reflecting the AI of passively acquired immunoglobulins. In four immunocompetent patients whose sera were taken less than 100 days after seroconversion, the mean AI was low (less than 35%) and was associated for 3 out of these 4 patients with a high concentration of CMV-specific IgM (IgM ratio > 3). Likewise, the AI of CMV-specific IgG in sera from 25 immunocompetent patients with suspected CMV infection was usually inversely correlated with CMV-specific IgM concentration. Thus, the use of these two parameters may help to date a CMV infection in immunocompetent patients especially in pregnant women.

AIDS-Related Opportunistic Infections↗
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

Host and viral characteristics affecting the response to interferon therapy in chronic hepatitis C.

OBJECTIVE: To define parameters determined before and after 4 weeks of interferon therapy (3 MU three times per week for 24 weeks) which could be reliable predictors of a response to therapy. PATIENTS: Thirty-four patients with chronic hepatitis C virus (HCV) infection were investigated prospectively. METHODS: A complete response was defined as the normalization of serum alanine aminotransferase levels (ALT) at the end of treatment. The genotype of HCV was determined and the level of HCV-RNA was quantitated both before and after 4 weeks of treatment. RESULTS: After 4 weeks, 16 out of 20 responders [95% confidence interval (CI) 54-94%] and two out of 14 non-responders (95% CI 2-44%) normalized their ALT levels (P = 0.0002). The prevalence of genotype 1b was significantly (P < 0.04) higher among non-responders (eight out of 10; 95% CI 44-92%) than in responders (four out of 18; 95% CI 4-40%). Before treatment, the viraemia determined by branched DNA was significantly lower in responders than in non-responders (46.4 versus 116 x 10(5) eq virus/ml). After 4 weeks of treatment, the level of viraemia in responders was still significantly lower than that in non-responders (22.8 versus 66 x 10(5) eq virus/ml). In responders, a significant decrease in the level of viraemia was observed after 4 weeks of treatment. CONCLUSION: In a stepwise regression analysis only age and the normalization of ALT levels after 4 weeks of treatment were predictive of response to interferon at the end of treatment.

Adult↗
PubMed1994

Enhanced detection of antibodies to hepatitis C virus by use of a third-generation recombinant immunoblot assay.

Fifty-seven sera with indeterminate results by the second generation RIBA (RIBA 2) for confirmation of hepatitis C virus (HCV) enzyme linked immunoassay (ELISA) reactivity were tested by the new third generation RIBA (RIBA 3). Thirty three (57.9%) displayed reactivity for at least one other band and were therefore classified as positive; two became negative and 22 (38%) remained indeterminate. The incidence of HCV viremia, as determined by the RNA polymerase chain reaction (PCR), was 75% for the latter sera. The data show that it is important to subject RIBA 3 indeterminate samples to PCR.

Adolescent↗
PubMed1994

Analysis of sera indeterminate by Ortho-HCV RIBA-2 by using three confirmatory assays for anti-hepatitis C virus antibody.

The diagnostic performances of three commercially available recombinant immunoblot assays (RIBAs) for anti-hepatitis C virus antibody were evaluated on 50 ORTHO-HCV RIBA-2 (RIBA-2)-indeterminate serum samples. Concordant interpretations were obtained with the three tests in 60% of the samples, with 56% positive, 2% indeterminate, and 2% negative results. Considering test performance in regard to the number of remaining indeterminate results, analyzing sera by RIBA-3, INNO-LIA HCV Ab III, and DECISCAN HCV reduced the number of samples reacting indeterminately to 40, 6, and 8%, respectively. The three serum samples classified as indeterminate in the INNO-LIA HCV Ab III as well as three of four serum samples interpreted as indeterminate in the DECISCAN HCV and 16 of 20 samples classified as indeterminate in the RIBA-3 were hepatitis C virus RNA positive by PCR. This study clearly shows the good performance of the three tests as confirmatory assays compared with that of the RIBA-2. However, according to the manufacturers' criteria of positivity, the INNO-LIA HCV Ab III and DECISCAN HCV appeared to be more suitable than the RIBA-3 for interpreting serum samples found indeterminate in the RIBA-2.

Antigens, Viral↗
PubMed1994

Transmission of human parvovirus B19 by plasma derived factor VIII concentrates.

Although clotting factor concentrates prepared from large pools of plasma are considered to be safe for enveloped viruses (HIV, HBV and HCV), these products are likely to remain at risk for non lipid enveloped viruses. The prevalence of positive IgG serology for human parvovirus B19 (HPV-B19) was determined in 53 children suffering from haemophilia A, who had been treated from birth with only one brand of a highly purified factor VIII concentrate prepared by ion exchange chromatography with a solvent-detergent step (HPSD-VIII). HPV-B19 seropositivity ranged from 20 to 43% in 198 age matched controls. In contrast, the incidence of positive HPV-B19 IgG serology varied from 75 to 100% in haemophiliacs and all 10 severe haemophilia A patients under 3 years of age were seropositive. The presence of HPV-B19 in this clotting factor concentrate demonstrates that at least a proportion of such products continue to transmit non lipid enveloped viruses.

Adolescent↗
PubMed1994

[Exudative gastropathy associated with cytomegalovirus infection after allogenic bone marrow transplantation].

The authors report a case of protein losing gastropathy associated with cytomegalovirus. This form which is extremely rare in adults occurred alone after allogenic bone marrow transplantation and become apparent by a hypoalbuminaemia causing oedema of the lower limbs. Gastrocopy showed large red folds of approximately a centimetre covered in a whitish hypersecretion coating. Biopsy demonstrated active gastritis which appeared on a hypertrophic and hypersecretive gastritis. Outcome was favourable within 3 months without treatment.

Adult↗
PubMed1994

[Parvovirus B19 and pediatric pathology].

B 19 parvovirus is a widespread virus with primary infestation generally occurring in childhood through family and community outbreaks. Its most typical manifestation is transient erythroblastopenia with aplastic crisis, often profound, mostly affecting patients with chronic hemolytic anemia, and eventually patients with defective erythropoiesis (chronic hypoplastic anemia, iron deficiency anemia). In normal individuals the primary infestation is usually asymptomatic but may give transient hematological signs for few days: moderate reticulocytopenia, thrombopenia and neutropenia. Clinically two phases of the infection are described: 1.) a first phase of viremia of 2 to 3 days which may be accompanied by fever and myalgias; 2.) a second phase which may last for several weeks with dermatological signs, the most typical being erythema infectiosum, vasculitis, arthralgias or arthritis. In pregnant women, the primary infestation with B 19 parvovirus may lead to fetal anemia and hydrops fetalis with uneven outcomes: fetal death, chronic erythroblastopenia after birth, spontaneous resolution. Although the incidence of fetal infestation in non immunized pregnant women is still unknown, the question is raised of the recognition and protection of non immunized pregnant women at high risk of exposition to infested subjects. Long term persistence of the virus in the organism may be responsible for chronic manifestation, essentially but not exclusively in immunodeficient-patients: prolonged erythroblastopenia and chronic rheumatologic manifestations. It may be also responsible for cases of juvenile arthritis, thrombocytopenic purpura and chronic neutropenia of childhood. The diagnosis of the viral infestation is mainly based upon the detection of specific IgM, then IgG, antibodies by Elisa technique.

Child↗