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J Petitjean

Publications and source records attributed to J Petitjean.

At least 37 records · Page 2Linked to original sources
PubMed1995

Detection of respiratory syncytial virus by reverse transcription-PCR and hybridization with a DNA enzyme immunoassay.

Nasal aspirates from 238 infants hospitalized with acute respiratory infections during the winter of 1994 and 1995 were tested for respiratory syncytial virus (RSV) by immunofluorescence assay (IFA) and the viral isolation technique (VIT) and by two PCR and hybridization methods: reverse transcription PCR 1 (RT-PCR1), which amplifies the RNAs of all RSV strains, and RT-PCR-2, which allows subgroup classification of RSV. RT-PCR-1 and RT-PCR-2 detected viral sequences in 56.7% (135 of 238) and 48.3% (115 of 238) of the samples, respectively, while only 80 (33.6%) samples were found to be positive by IFA and VIT. Of the PCR-positive specimens, 57 were missed by these routine techniques in RT-PCR-1 and 45 were missed in RT-PCR-2. Although the RSV-PCR-1 and RSV-PCR-2 techniques amplified two different sequences of the RSV genome, they gave similar results for 218 (91.6%) nasal aspirates. Compared with conventional methods, the sensitivity, specificity, and agreement were 97.5, 63.9, and 75.2%, respectively, for RT-PCR-1 and 89.7, 71.9, and 77.7%, respectively, for RT-PCR-2, and for these two RT-PCR assays, the positive predictive value (PPV) and the index of agreement (kappa) were comparable and moderate, respectively: PPV was 57.8% and kappa was 0.52 in RT-PCR-1, and PPV was 60.9% and kappa was 0.54 in RT-PCR-2. However, there was a perfect correlation between the two RT-PCRs, with a PPV of 100% and an excellent index of agreement (kappa = 0.88). Therefore, most RT-PCR results were really true positive, and VIT and IFA, which missed some of them, appeared to be less sensitive.

Base Sequence↗
PubMed1994

[Virological diagnosis and treatment of respiratory syncytial virus infections].

Respiratory syncytial virus infections occur frequently in children, often localized in the upper respiratory tract. Outcome is usually quite satisfactory, but in nearly one half of the infants lower tract involvement may cause severe respiratory insufficiency leading to hospitalization in about 1% of the cases. Its frequency has been estimated at 20 to 30% of the viral infections in hospitalized infants, 10 times the frequency of the other respiratory virus. Respiratory syncytial epidemias last about 4 to 5 months with a seasonal peak in december and january. The direct detection of respiratory syncytial antigens in nasal specimens by immunofluorescence or enzymatic immunoassay is the key to rapid diagnosis. They appear as performant and more convenient than specific IgM antibodies or nucleic acid detections, and than virus isolation on cell culture, which is justified to evaluate strain sensitivity to ribavirin. Immunofluorescence has also been used to identify the subgroups A and B from 1981 to 1993, and respiratory syncytial subgroup A seems to signify more severe disease. Symptomatic assistance may require hydratation, oxygenotherapy and respiratory physical therapy. Antibiotics should not be given as a routine treatment since bacterial superinfection is infrequent, but may be indicated in cases with associated signs of complications. Indications for bronchodilators and corticosteroids are still under debate. Significant results have been obtained with ribavirin and specific anti respiratory syncytial immunoglobulins but further evaluations are still required to precise their use in clinical practice.

Antibodies, Viral↗
PubMed1994

Detection of enteroviruses in cerebrospinal fluids: enzymatic amplification and hybridization with a biotinylated riboprobe.

Cerebrospinal fluids from 54 children with meningitis syndrome were examined for the presence of enteroviruses by cell culture, by enzymatic amplification of viral cDNA and by hybridization. Viral sequences were found in 37/39 CSF specimens positive by cell culture (95%) and in 6/15 (40%) CSF specimens negative by cell culture. Thus, PCR, as a specific and sensitive technique, may be suitable for rapid diagnosis of enteroviral meningitis in clinical specimens from which enteroviruses are difficult to isolate.

Base Sequence↗
PubMed1994

Comparison of nested PCR for detection of DNA in plasma with pp65 leukocytic antigenemia procedure for diagnosis of human cytomegalovirus infection.

A nested PCR was used for the detection of human cytomegalovirus (HCMV) DNA in plasma. The presence of HCMV DNA and its correlation to pp65 leukocytic antigenemia were investigated with 299 blood samples from 45 organ transplant recipients and 63 AIDS patients. Of the 53 samples positive by nested PCR, 52 (98%) were also positive for leukocytic antigenemia and 23 had high levels of antigenemia (> 50 positive cells per 2 x 10(5) leukocytes). Of the 246 samples negative in PCR, only 3 (1.2%) had highly positive antigenemia. For 15 patients having a high antigenemia level in the course of their disease, consecutive blood samples were studied and also assessed for viremia in culture. The extent to which HCMV DNA, detected by PCR, was present in plasma correlated with increased levels of HCMV leukocytic antigenemia for six of the eight AIDS patients and for all the organ transplant recipients. Positivity for HCMV DNA in PCR and for viremia in cell culture was usually restricted to the highest antigenemia levels. From a total of 69 blood samples, PCR and culture gave positive results, respectively, for 17 of 32 samples (53%) and 14 of 32 samples (43%) from transplant recipients and for 15 of 37 samples (40%) and 9 of 37 samples (24%) from AIDS patients. Our findings have shown a strong correlation between high levels of leukocytic antigenemia and HCMV DNA in plasma. The detection of HCMV DNA in plasma by this nested PCR can prove HCMV dissemination in blood, but it lacks the rapidity and simplicity of the leukocytic pp65 antigenemia procedure.

AIDS-Related Opportunistic Infections↗
PubMed1993

Decreased blood TcR gamma delta+ lymphocytes in AIDS and p24-antigenemic HIV-1-infected patients.

The significance of blood TcR gamma delta+ lymphocyte level was evaluated in the context of immunodeficiency and infections in 209 HIV-1-infected patients. Blood TcR gamma delta+ lymphocyte values were found higher in patients belonging to the CDC group II/III than those in the CDC groups IV C1 and IV D (P < 0.001) and P < 0.01, respectively). TcR gamma delta+ lymphocyte counts were lower in patients with oral candidiasis (P < 0.01), and in association with pneumocystosis or toxoplasmosis (P < 0.001). In 81 patients with a detectable HIV-1 p24 antigenemia, TcR gamma delta+ lymphocyte counts were lower than those in nonantigenemic patients (P < 0.001). In the CDC II/III group, p24-antigenemic patients exhibited lower TcR gamma delta+ cell counts than those in patients without antigenemia (P = 0.06). Data suggest that depletion of the TcR gamma delta+ lymphocyte subset characterizes HIV-1-infected patients with oral candidiasis, pneumocystosis, toxoplasmosis, and/or HIV-1-antigenemia.

AIDS-Related Opportunistic Infections↗
PubMed1993

[Prevalence and clinical aspects of A and B subgroups of respiratory syncytial virus infection. Observation of 8 consecutive epidemics between 1982 and 1990].

BACKGROUND: Infants suffering from respiratory syncytial virus (RSV) infection can have severe responses that require intensive care. This study compares the epidemiologic patterns and the severity of respiratory diseases produced by RSV strain subtypes A and B. POPULATION AND METHODS: The prevalence of RSV subgroups was studied over 8 consecutive outbreaks from 1982 to 1990. The files of 73 infants aged from 1 to 24 months admitted because of RSV infection between October 1987 and March 1990 were studied. The criteria of severity were tachypnea and/or the use of the accessory muscles for respiration, apnea and/or cyanosis, hospitalization for > 8 days, hypercapnia and/or acidosis, oxygen therapy, use of corticosteroids and/or bronchodilators, nutritional difficulties. RESULTS: A total of 374 RSV strains were isolated: 142 were group A and were 232 group B. Subtype A predominated during the winter 1987-1988 and subtype B during 1983-1984, 1984-1985 and 1989-1990. Some indicators of severity, such as degree of respiratory distress, duration of hospitalization and levels of oxygen saturation, were correlated with A subgroup infections, but the difference in the severity index for the two subtypes was not statistically significant. CONCLUSIONS: The results are not consistent with other previous reports, perhaps because different indicators of severity were used in this study and infants less than one month old or having other underlying diseases were excluded.

Acute Disease↗
PubMed1993

[Virus and dilated cardiomyopathies].

Dilated cardiomyopathy is so called when an etiological investigation is negative and no cause can be found for ventricular dilatation-hypokinesia. Current research points to genetic, immunological and infectious factors, often associated, and the passage of subclinical viral myocarditis to chronic disease. There is a lot of evidence in favour of this hypothesis. In the experimental model, the relationship between viral myocarditis and dilated cardiomyopathy has been demonstrated with, as cofactors, a genetic predisposition and an immunitary deficiency leading to an auto-immune subacute myocarditis. In the clinical setting, the enterovirus with a high cardiac tropism seems to play an epidemiological role in the genesis of dilated cardiomyopathy. The concentrations of neutralising anti-coxsackie B virus antibodies is higher in subjects with dilated cardiomyopathy than in a control population. The frequency of lymphocytic infiltration, a marker of dysimmunitary myocarditis, is variable from study to study but the presence of sequences of enterovirus genome in the myocardium could explain slow replication of the virus progressively destroying the myocytes. Techniques of molecular hybridization with or without prior genic amplification by the "Polymerase Chain Reaction" have demonstrated such sequences of specific enterovirus genome but discordant results require further studies.

Cardiomyopathy, Hypertrophic↗
PubMed1993

[Cytomegalovirus infection after transplantation. Virological diagnosis, antiviral treatment].

Cytomegalovirus (CMV) is an important cause of morbidity in organ transplant recipients with two major clinical effects: allograft rejection and pneumonitis. The issue of effective therapy has increased the need for accurate and rapid laboratory methods for diagnosis of viral infections. ELISA, as the most serological sensitive tests, are useful for the identification of active CMV infection, and the serological response can be sometimes detected before viral excretion. There are several commercial reagents for the detection of IgG or IgM CMV antibody, and a great variability in terms of sensibility and specificity. Because of the slow process of isolating CMV in cell cultures, immediate-early antigen detection in infected cells within one or two days of culture, increases twice the sensitivity of viral isolation for leukocyte or bronchoalveolar (BAL) specimens. Differences in sensitivity of the direct detection of CMV antigen in BAL specimens has been reported. Direct detection of CMV antigen in leukocytes is particularly important because CMV viremia is considered to be predictive of significant CMV disease. CMV antigen detection within leucocytes, by immunofluorescence with the aid of monoclonal antibodies to CMV phosphoprotein PP-65, appears to be as specific, more sensitive, and allows a more rapid diagnosis than virus isolation techniques. Some specific CMV probes are now available, but the hybridization techniques involving dot-blot assays of urine or BAL are not enough sensitive to detect small amounts of virus. Closely sensitivity to isolation in culture has nevertheless been reported in the polymorphonuclear fraction of the blood cells.(ABSTRACT TRUNCATED AT 250 WORDS)

Antibodies, Viral↗
PubMed1993

[A prospective study of mycoplasma infection in a neonatal unit].

Ureaplasma urealyticum and Mycoplasma hominis were recovered from nasopharyngeal aspirates from 25% of 63 infants admitted to a neonatal unit; this proportion is significantly higher than that seen in a control population of maternity ward babies (0%). Birth by cesarean section was associated with a reduced risk of recovery of mycoplasmas. No specific diseases were significantly associated with recovery of mycoplasmas; furthermore, no obstetrical factors were associated with recovery of mycoplasmas from the neonates and no association was found between mycoplasma infection and respiratory distress. However, fetal distress, probably of multifactorial origin, was found in 44% of neonates with positive cultures for Ureaplasma urealyticum; this proportion was significantly elevated as compared with the subgroup of infants negative for U. urealyticum, suggesting that fetal distress may increase the infectivity of this opportunistic organism.

Cross Infection↗
PubMed1992

[Leukocytic cytomegalic antigen. A new diagnostic method of cytomegalovirus infection after transplantation].

The occurrence of cytomegalovirus (CMV) viremia after transplantation is predictive of visceral lesions. Three-hundred and sixty blood samples were collected from 21 transplant recipients and examined. Direct CMV antigen detection was positive in 41 samples (11.4 percent), rapid viral isolation in 24 samples (6.7 percent) and conventional cell culture in 9 cases (2.5 percent). Direct detection of CMV antigen in blood leucocytes is as specific as, and more sensitive and rapid than isolation in culture. In 50 percent of secondary infections the antigenaemia assay and serology were equally sensitive, and antigenemia appeared earlier in 2 primary infections.

Antibodies, Monoclonal↗
PubMed1992

Detection of enteroviruses in endomyocardial biopsy by molecular approach.

Enteroviruses are considered to be the most common agents implicated in myocarditis and cardiomyopathy. Recent studies have suggested persistent enterovirus infection in chronic disease showing the presence of enteroviral RNA in the myocardium. We used gene amplification by PCR which can demonstrate directly the presence of enteroviral sequences in endomyocardial biopsies. The primers were chosen in the 5' non-coding region of the genome representing highly conserved sequences among enteroviruses and therefore allowed the amplification of the majority of enteroviruses. The hybridization of the amplified products was effected with specific general riboprobe derived from 5' non-coding sequences internal of the amplified fragments. The results include 105 patients distributed in 6 groups: 45 idiopathic dilated cardiomyopathies with 66.7%, 17 alcoholic cardiomyopathies with 52.9%, 10 myocarditis with 30%, 5 multifactorial cardiomyopathies with 40%, 5 patients with immunosuppressive therapy with 100%, and 23 control group without viral etiology with 39.1% positive samples. The study suggested a positive link between viral infection and cardiomyopathies, but did not allow a direct relation between enterovirus infection and idiopathic dilated cardiomyopathy to be established.

Adolescent↗
PubMed1992

[Influenza A infection in children. Clinical spectrum and comparison with respiratory syncytial virus infection during the winter 1989-1990].

BACKGROUND: Respiratory syncytial viral (RSV) infection can be rapidly differentiated from influenza viral infection by immunofluorescence techniques. These tests were used to identify some epidemiological and clinical characteristics of both infections. METHODS AND PATIENTS: 77 RSV and 22 influenza viral infections were detected during an outbreak (November 1989 to March 1990) in 210 children less than 6 years admitted for lower respiration tract infections. The fluorescent antibody assay was performed on nasal aspirates. RESULTS: The RSV outbreak ran from November to March, while the influenza outbreak was shorter, during December and January. The patients infected with RSV were younger (mean age: 6.7 months) than those infected with influenza virus (mean age: 20.9 months) (p < 0.001). Those with influenza virus infection presented with higher temperatures, more often had initial seizures (p < 0.05) and displayed fewer clinical or X-ray respiratory symptoms (p < 0.001). Mean durations of hospitalization were 9.9 days for RSV infection and 7.7 days for influenza virus infection. The therapeutic use of bronchial dilators, oxygen and steroids was correlated with the degree and duration of respiratory manifestations. A 3 month follow-up was insufficient to show any difference between recurrences or complications in the two groups. CONCLUSION: The clinical and radiological differences in these two groups of patients viral-infected are similar to those described in the literature. Variability from one outbreak to another precludes any extrapolation to other populations and justifies the systematic use of the fluorescent antibody assay, especially when a specific antiviral therapy is considered.

Child↗
PubMed1991

[Virologic diagnosis of interstitial pneumonia].

Viral pneumonia is not very frequent in healthy adults; it is mostly observed in elderly subjects infected with an influenza virus, a respiratory syncytial virus (RSV) or an adenovirus (AdV). In immunocompromised subjects, cytomegalovirus (CMV) is the most common of causal agents. From the point of view of clinicians, virological diagnostic methods must be rapid and specific, and for this reason direct examination techniques for respiratory specimens and immunological detection of virus are currently being developed in virology laboratories. These techniques make it possible, for example, to identify in less than two hours influenza viruses, RSV or AdV in bronchial secretions and CMV in bronchoalveolar lavage fluid after celle centrifugation. Virus isolation in cell cultures is the reference method, but the result is often delayed and the search for seroconversion may take several weeks.

Adult↗