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Biomedical subjects

A Garbarg-Chenon

Publications and source records attributed to A Garbarg-Chenon.

At least 37 records · Page 2Linked to original sources
PubMed1997

Effect of laser irradiation on latency of herpes simplex virus in a mouse model.

Low power Laser irradiation is used in medical practice for different indications. Several firms which commercialise Laser claim that Laser irradiation may be beneficial towards Herpes virus pathogenicity. We observe that, in the ear experimental model of HSV latency [3], repeated exposure to infrared Laser radiation of cervical ganglia following HSV inoculation appears to specifically hinder the establishment of virus latency in mouse.

Animals↗
PubMed1996

Comparative DNA analysis of Bordetella pertussis clinical isolates by pulsed-field gel electrophoresis, randomly amplified polymorphism DNA, and ERIC polymerase chain reaction.

We used DNA fingerprinting by pulsed-field gel electrophoresis (PFGE), randomly amplified polymorphic DNA (RAPD) and PCR amplification of enterobacterial repetitive intergenic consensus sequences (ERIC-PCR) to compare 15 clinical isolates of Bordetella pertussis recovered between August 1993 and September 1995 from 13 infants and two adults, living in the same geographic area. PFGE produced 10 patterns and made it possible to differentiate all the isolates and to indicate an intrafamilial transmission. RAPD and ERIC-PCR generated banding patterns with small differences and had a poor discriminatory power. During the last 2 years, at Armand-Troussau pediatric hospital, 10 distinct clones of clinical B. pertussis isolates, with a predominant clone including seven strains, could be determined by the PFGE method.

Adult↗
PubMed1996

Molecular epidemiology of Burkholderia cepacia, Stenotrophomonas maltophilia, and Alcaligenes xylosoxidans in a cystic fibrosis center.

Burkholderia cepacia, Stenotrophomonas maltophilia, and Alcaligenes xylosoxidans have been isolated with increasing frequency from the sputum of patients with cystic fibrosis in a pediatric hospital. In 1994-95, 27 of 120 patients were persistently colonized, 17 with Burkholderia cepacia, eight with Alcaligenes xylosoxidans, and five with Stenotrophomonas maltophilia. Genotyping of 220 clinical isolates revealed that most of the Burkholderia cepacia strains were clonally related, suggesting either cross-infection or a common source of exposure. In contrast, neither cross-infection nor a common source of exposure appear to have occurred in the cases of Alcaligenes xylosoxidans or Stenotrophomonas maltophilia.

Alcaligenes↗
PubMed1996

Nosocomial CDC group IV c-2 bacteremia: epidemiological investigation by randomly amplified polymorphic DNA analysis.

The CDC group IV c-2 bacterium is a gram-negative bacillus rarely isolated from clinical specimens. This organism caused catheter-related bacteremia in five immunocompromised children hospitalized in two distinct wards of our institution between November 1993 and October 1994. Three patients recovered on empiric antibacterial chemotherapy combining ceftazidime and amikacin, and a fourth patient required imipenem instead of ceftazidime. The fifth patient recovered without treatment. Catheter removal was never necessary. The randomly amplified polymorphic DNA technique with three different primers was applied to nine isolates recovered by culturing blood from the five children and showed that all of the patients harbored isolates of the same genotype. The source of the outbreak could not be determined.

Adolescent↗
PubMed1996

[Molecular epidemiology of pneumococci with decreased susceptibility to penicillin isolated in a Parisian pediatric hospital].

Pneumococci with decreased susceptibility or resistant to penicillin (PRP) have been isolated with an increasing frequency in France. Among PRP, isolates of serotypes 23F and 9V were the most frequently recovered in our children's hospital. Penicillin-resistance is due to the appearance of altered penicillin binding proteins (PBPs) with reduced affinity for beta-lactam antibiotics. 3 PBPs have been well studied, 2b, 2x and 1a, and the sequences of their genes have been determined. Our molecular epidemiological study of 14 PRP 9V and 26 PRP 23F isolated mainly from otitis in 1993-94, consisted of determining chromosomic restriction patterns (Apa I) by pulsed-field gel electrophoresis, and restriction patterns (Hinf I) of PBP genes pbp 2b, pbp 2x and pbp 1a after PCR. All the PRP 9V exhibited the same pulsotype and identical patterns for each of the genes pbp 2b, pbp 2x and pbp 1a, suggesting a clonal origin. The origins of PRP 23F were more heterogenous: 5 clones could be defined, with one predominant clone composed of 20 isolates. Most of the PRP 23F shared identical profiles for the genes pbp 2b, pbp 2x and pbp 1a with the PRP 9V, suggesting a horizontal transfer of DNA. Molecular markers, which provide more informations than serotyping, were useful to clarify the complex epidemiology of PRP.

Child↗
PubMed1996

Pseudomonas (Burkholderia) cepacia in children with cystic fibrosis: epidemiological investigation by analysis or restriction fragment length polymorphism.

Since 1987, Pseudomonas cepacia has been isolated with an increasing frequency in the expectorants of children with cystic fibrosis followed at the Hôpital d'enfants Armand Trousseau (Paris, France). Colonization by P. cepacia may be responsible for serious secondary infections and rapid deterioration in respiratory function in these patients. Among the 130 children attending our centre, 14 (8 girls and 6 boys) aged 3 to 18, exhibited chronic colonization. 132 isolates, originating from sputum obtained between 1992 and 1994 were studied. Nine biochemical patterns and 6 antibiotic susceptibility patterns at least were defined, therefore exhibiting great polymorphism. Chromosome restriction patterns with Xba I after pulsed field gel electrophoresis enabled 4 pulsotypes to be identified: A, B, C and D. Thirteen patients harboured pulsotypes A, C and D, and 1 patient pulsotype B, the last being quite distinct from the first three. Pulsotypes A, C and D were almost similar, suggesting that closely related strains, probably the same strain, was harboured by 13 of the 14 patients. The origin could be contamination from a single source, or stem from patient-to-patient crossed transmission.

Adolescent↗
PubMed1994

Comparative analysis of VP8* sequences from rotaviruses possessing M37-like VP4 recovered from children with and without diarrhoea.

Rotavirus strains belonging to G types 1 to 4 and having a P3 genotype (M37-like VP4) were recovered from children with symptomatic and asymptomatic infections. Partial sequences of their VP4 genes were determined in an attempt to characterize these strains further. The genomic regions encoding VP8*, the connecting and putative fusion peptides and three other regions in VP5* were sequenced. The deduced amino acid sequences were compared with rotavirus strains belonging to different P genotypes that had been previously reported. High degrees of identity were found between the VP8* fragment of all human P3 strains (92.7 to 99.7%) suggesting that they belong to the same genotype, regardless of differences in their virulence. Furthermore, based on comparative sequence analysis, we did not identify any amino acid(s) that differ appreciably between symptomatic and asymptomatic strains and could therefore be associated with virulence. The results suggest that the P3 genotype, although frequently associated with asymptomatic infections, may not be the single determining factor in attenuation of symptoms.

Amino Acid Sequence↗
PubMed1994

[Cytomegalovirus pneumopathies in pediatric intensive care units].

BACKGROUND: Cytomegalovirus (CMV) infection can result in major complications in immunocompromised infants and children. CMV pneumonia may be difficult to diagnose and the true pathogenic role of the virus in the disease is not always clear. This report describes a cohort of 20 children who suffered from CMV pneumonia. POPULATIONS AND METHODS: Twenty children aged 1 month to 11 years 10 months were admitted to our intensive care unit between 1981 and 1990 because of pneumonia with evidence of CMV infection. They were classified into three groups: group I (cases 1-10) with hemopathy or cancer, group II (cases 11-14) with AIDS, and group III (cases 15-20): non immunodeficient or immunosuppressed children. CMV infection was diagnosed after isolation of CMV from bronchoalveolar lavage (BAL) fluid (15 patients), lung biopsy revealing intranuclear inclusions or CMV antigens, or CMV-positive cultures (four patients), CMV-positive urine cultures (one patient). RESULTS: Clinical manifestations and X-rays findings were unspecific; interstitial pneumonia was found only in immunodeficient patients. CMV pneumonia was diagnosed only in two patients on post mortem examination. Concomitant pneumocystis carinii was found on BAL in two patients (group I) and two others (group II). Thirteen patients required ventilation. Eleven patients were given ganciclovir for 2 or 3 weeks; one of them was given a single dose. This treatment was well tolerated. Mortality was 90% in group I, 100% in group II and 33% in group III. CONCLUSION: Ganciclovir did not appear to benefit the immunocompromised patients with CMV pneumonia. Future treatment should include hyperimmune CMV immunoglobulins plus ganciclovir. Careful hand washing is important for all those caring for these patients to prevent contamination as is the use of CMV-negative blood products.

Child↗
PubMed1993

Virus isolation, polymerase chain reaction and in vitro antibody production for the diagnosis of pediatric human immunodeficiency virus infection.

Viral culture (VC), polymerase chain reaction (PCR) and in vitro antibody production (IVAP) by peripheral blood mononuclear cells were compared for the early diagnosis of HIV-1 infection in 46 infants born to HIV-1 seropositive mothers. The ten children considered infected on the basis of clinical signs and persistence of anti-HIV-1 antibodies had at least one positive viral culture and seven were always positive in both PCR and IVAP tests. PCR and IVAP tests were occasionally negative in three infected children. Among 30 healthy children who became seronegative and were always negative for viral culture, 22 (73.3%) were also repeatedly negative in PCR and IVAP. We report 6 cases of children classified as P2A at the term of this study but who had lost anti-HIV-1 antibodies. They presented at least one positive viral culture and occasional positive PCR and/or IVAP results. The results indicate that the combination of viral culture, PCR and IVAP tests improves the early diagnosis of pediatric HIV infection.

Antibody Formation↗
PubMed1993

Epidemiological study of infantile rotavirus diarrhoea in Tananarive (Madagascar).

An epidemiological study of rotavirus infections was conducted in Tananrive, Madagascar, from November 1988 to October 1990. Rotavirus antigen was detected by ELISA in faecal specimens of 183 of 1,659 children with acute diarrhoea (11%) and in 11 of 631 specimens from children without diarrhoea (1.7%). Rotaviral diarrhoeas were most frequently found in infants aged 6 to 18 months and occurred throughout the year with a definite peak during the first winter months. Analysis of the viral RNA by polyacrylamide gel electrophoresis permitted the characterisation of 170 and 194 strains identified. Nine different electropherotypes (A-I) and one mixed infection were observed. The "short" electropherotypes (A-E) were predominant and represented 140 strains (82.4%), and the "long" electropherotypes (F-I and M) represented 30 strains (17.6%). The "short" electropherotype A (cafb) was the most frequent in our environment (45.3% of cases) and was predominant during the first 14 months of the study. The "long" electropherotype F (bbea) appeared in July 1990 and was predominant during the last three months. Among these children with diarrhoea, the presence of rotavirus was significantly associated with vomiting, fever, and moderate to severe dehydration. However, no significant differences in the occurrence of these symptoms were found between the "short" and "long" electropherotypes.

Adolescent↗
PubMed1992

Multicentre quality control of polymerase chain reaction for detection of HIV DNA.

OBJECTIVE: Seven French laboratories tested the specificity and sensitivity of the polymerase chain reaction (PCR) for the detection of HIV-1 DNA. METHODS: Following its own PCR protocols, each laboratory independently tested blind two panels of 20 coded peripheral blood mononuclear cell samples collected from HIV-1-seropositive individuals and from HIV-1-seronegative individuals at high or low risk of HIV infection. For the first panel, laboratories were free to select type and number of primers; for the second, all were required to use the two primer pairs Pol 3/4 and MMy 9/10' (Nef 1). RESULTS: False-positive and false-negative results were observed in all laboratories (concordance with serology ranged from 40 to 100%). In addition, the number of positive PCR results did not differ significantly between high- and low-risk seronegatives. The use of crude cell lysates in DNA preparation produced the same PCR results as phenol-extracted DNA. Discrepancies between laboratories indicated that factors other than primer pairs contributed strongly to laboratory variability. CONCLUSIONS: Our results emphasize the importance of both positive and negative controls in PCR and demonstrate the value of multicentre PCR quality control.

Base Sequence↗
PubMed1992

Detection of Mycoplasma pneumoniae in clinical samples from pediatric patients by polymerase chain reaction.

The polymerase chain reaction (PCR) technique was used to detect Mycoplasma pneumoniae DNA in clinical samples (nasopharyngeal aspirations or bronchoalveolar lavages) obtained from 100 children, 1 month to 16 years old. PCR allowed the detection of M. pneumoniae DNA from 20 out of the 100 patients studied. In 16 cases, PCR positivity was associated with acute respiratory symptomatology. For five PCR-positive patients, a positive culture or a serological response evidenced acute M. pneumoniae infections. A lack of antibody response was observed particularly with immunocompromised children and infants less than 12 months old. The amount of M. pneumoniae DNA in the PCR was estimated in a semiquantitative way by comparison of its hybridization signal with those obtained for 100, 10, and 1 color-changing unit (CCU) of the M. pneumoniae FH strain. Small amounts (less than or equal to 10(2) CCU/ml) of M. pneumoniae were found in samples from asymptomatic patients, while larger amounts (greater than or equal to 10(2) to greater than or equal to 10(4) CCU/ml) were found for 8 out of 10 patients with acute pneumonia.

Adolescent↗
PubMed1992

[Macrophage activation syndrome and dysgammaglobulinemia. Role of the Epstein-Barr virus].

The case of a five-year-old boy with macrophage activation syndrome and Epstein-Barr virus infection is reported. Several unusual features were found, including an early major increase in IgA levels, persistent oligoclonal gammapathy, and delayed development of anti-EA antibodies accompanied with an increase in anti-VCA antibodies. Despite the negative family history, an immune deficit and Purilo syndrome are discussed as possible diagnoses in this child.

Blotting, Southern↗
PubMed1991

[Virologic diagnosis of cutaneomucous herpes].

The virological diagnosis of herpes simplex infection rests on the demonstration of the virus or its constituents in lesions of the skin and/or mucous membranes. The reference method is isolation of the virus in cell cultures, but the recent development of enzyme immunoassays has led to a rapid and highly specific diagnosis. The present possibility of a selective and affective treatment enhances the value of an accurate virological diagnosis.

Herpes Simplex↗
PubMed1990

Nucleotide sequence of SHV-2 beta-lactamase gene.

The nucleotide sequence of plasmid-mediated beta-lactamase SHV-2 from Salmonella typhimurium (SHV-2pHT1) was determined. The gene was very similar to chromosomally encoded beta-lactamase LEN-1 of Klebsiella pneumoniae. Compared with the sequence of the Escherichia coli SHV-2 enzyme (SHV-2E.coli) obtained by protein sequencing, the deduced amino acid sequence of SHV-2pHT1 differed by three amino acid substitutions.

Amino Acid Sequence↗
PubMed1990

Dot ELISA for direct detection of BK virus in urine samples.

The dot ELISA technique was applied for direct detection of BK virus in clinical urine samples. The assay was performed on nitrocellulose paper dotted with the polyethylene glycol precipitated urine samples free of cellular debris. BK virus was detected with an anti-BK virus monoclonal antibody, and the complex was visualized by immunoperoxidase staining. Positive reaction appeared as well-defined dark blue spots. Of the 110 urine samples examined, 31 were positive in the dot ELISA and 79 proved negative. Comparing with the IIF results, the dot ELISA had a 88.46% of sensibility and 90.4% of specificity, and the results agreed completely in 99 samples. The simple dot ELISA technique can be recommended for detection of BK virus excretion in routinary diagnostic.

Animals↗