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Biomedical subjects

M Chambon

Publications and source records attributed to M Chambon.

At least 19 recordsLinked to original sources
PubMed2002

[Enteroviral meningitis in adults, underestimated illness: description of 30 observations from 1999 to 2000, and evolution of clinical practices during 2001].

Enteroviral meningitis is well documented in children but underestimated in adults. The analysis of 30 cases of adult meningitis prospectively diagnosed by enterovirus genome detection (RT-PCR) in cerebrospinal fluid (CSF) between 1999 and 2000 in routine practice showed diagnosis to be problematic. Characteristic symptoms were inconstant (the association of fever/headache/stiff neck absent in 41%) and sometimes misleading (the presence of peribuccal lesions). CSF data showed a predominance of lymphocytes in only 44% of patients. The most reliable criterion was normal constant CSF glucose levels. Thirty three per cent of patients were admitted during cold months. Management of patients varied markedly between departments, and included computed tomography (33%), and the prescription of aciclovir (20%) or antibiotics (53%). A report of positive enterovirus RT-PCR had only low impact on management because it took 6 days to obtain the results (versus 3 days in children during the same period). These findings were communicated to all hospital physicians concerned and as a result, the number of RT-PCR in adults increased significantly during 2001. Again, enteroviral meningitis was diagnosed in adults despite a much lower incidence of the illness in 2001 compared to 2000. Thus this pathology should not be underestimated in adults. Considerable medical expenditure might be avoided (cumulative numbers of 172 days in hospital and 82 days of antibiotics in this study), if rapid and accurate diagnostic techniques were available.

Acyclovir↗
PubMed2001

Circulation of enteroviruses and persistence of meningitis cases in the winter of 1999-2000.

The seasonal incidence of enterovirus meningitis was analyzed in a prospective study of patients admitted for suspected meningitis from October 1, 1998 to April 30, 2000. In-house reverse transcription-polymerase chain reaction (RT-PCR) in cerebrospinal fluid (CSF) was used irrespective of cytological results. Fifty-two (45.2%) of the 115 patients had positive RT-PCR in CSF, including 44/86 children (51.2%) and 8/29 adults (27.6%). Six of the 52 (11.5%) had no pleocytosis. The numbers of CSF specimens with a predominance of lymphocytes or a predominance of neutrophils were closely similar. In 33 of the positive patients, an enterovirus, mainly echoviruses type 6 (48%) and 30 (24%), was recovered in one or more specimens. Sixteen cases of enteroviral meningitis were observed between November 1999 and March 2000 as against 2 cases between November 1998 and March 1999, showing that the disease persisted through the winter months of 1999-2000. During the same period, 96 enterovirus isolates were recovered from clinical specimens from other patients. The number of isolates was higher in the winter of 1999-2000 (P < 0.01) than in the winter of 1998-1999, indicating that the risk of enterovirus infection increased significantly in winter 1999-2000. Sixteen patients had aseptic meningitis, made a rapid recovery and had an enterovirus in throat swabs and stools (9/16) or in one of the two (7/16). RT-PCR was not requested. Nine patients were admitted during the cold months. The clinical management of both adult and child patients could be improved by year-round use of enterovirus generic RT-PCR.

Adolescent↗
PubMed2001

Prospective analysis of 61 cases of enteroviral meningitis: interest of systematic genome detection in cerebrospinal fluid irrespective of cytologic examination results.

BACKGROUND: Enteroviruses are the most commonly identified cause of viral meningitis. Detection of the enterovirus genome in cerebrospinal fluid (CSF) using reverse-transcription polymerase chain reaction (PCR) has proved to be useful in diagnosis and is more rapid and sensitive than viral cultures. In routine practice, cytologic examination results of CSF are obtained swiftly and PCR indication is performed as a second step. OBJECTIVES: The aim of this study was to determine, by analysis of complete data from CSF results for 61 cases of proven enteroviral meningitis, whether cytologic CSF findings can be used to establish viral etiology and to indicate if PCR assay should be performed. STUDY DESIGN: From a prospective study of children admitted during 1997 for suspected enterovirus meningitis in which PCR and viral cultures of CSF were systematically performed, we selected 61 patients with proven enterovirus meningitis. We compared global white cell count (WCC), relative percentage of lymphocytes/neutrophils, PCR and culture for enterovirus, patient age, and clinical data. RESULTS: 92% of patients (56/61) had positive PCR in CSF and in 48% (29/61) enterovirus was isolated in CSF. Nine patients (14.75%) had WCC<10/mm(3); eight of them had positive PCR and two had positive culture. There were comparable numbers of CSF with a predominance of lymphocytes (n=25) and CSF with a predominance of neutrophils (n=22), and of positive PCR and positive cultures of CSF in the two groups. Results were not influenced by the age of the patients. CONCLUSION: Irrespective of other CSF parameters, it seems difficult to dispense with PCR assay for enterovirus genome detection. It should be introduced as a true rapid routine test. Early reporting of a positive PCR result could result in a considerable saving in health resources.

Adolescent↗
PubMed2000

Effects of liver transplantation on long-chain polyunsaturated fatty acid status in infants with biliary atresia.

BACKGROUND: The long-chain polyunsaturated fatty acid (LC-PUFA) status of infants with untreated biliary atresia (BA) is known to be poor and is correlated to the severity of the liver disease. Liver transplantation (LT) markedly increases survival of patients with BA but the extent to which this reverses poor LC-PUFA status is not known. METHODS: To explore this question, the erythrocyte (red blood cell, RBC) phospholipid content of eight infants with BA who underwent LT was determined 2 months after an initial portoenterostomy, immediately before LT, and 6 and 12 months after LT. Before LT, all infants were fed a protein hydrolysate formula containing medium-chain triglycerides and essential fatty acids. Afterward, they were fed a normal diet for age. The RBC phospholipid content at each time point was compared with that of 28 age-matched control infants. RESULTS: Just before LT, median RBC phospholipid content of C20:4n-6, C20:5n-3, and C22:6n-3 was 25%, 48%, and 30% lower, respectively, than that observed in age-matched control infants. After LT, the RBC phospholipid content of most fatty acids reached normal values by 6 months. However, that of C20:4n-6 and C22:6n-3 contents remained 5% and 15% lower, respectively, than in normal control infants. Twelve months after LT, C20:4n-6 content remained lower than in normal children, but that of C22:6n-3 did not differ. The ratio of C20:3n-6/C20:4n-6, a reflection of delta-5 desaturase activity, was abnormal compared with normal children before LT (0.17 vs. 0.10, P < 0.009) but normalized by 6 months after LT (0.11 vs. 0.10, not significant). CONCLUSIONS: These data show that the abnormal LC-PUFA status of children with BA improves after LT but is not entirely reversed within a year after surgery. They suggest that the abnormal status before LT may be secondary, in part, to low delta-5 desaturase activity. The extent to which a different pre- and/or post-LT diet can prevent PUFA deficiency and/or hasten recovery of PUFA status remains to be determined.

Biliary Atresia↗
PubMed2000

Genomic variations in echovirus 30 persistent isolates recovered from a chronically infected immunodeficient child and comparison with the reference strain.

Seven sequential isolates of echovirus type 30 (EV30) were recovered over 22 months from a child with severe combined immune deficiency syndrome. The nucleotide sequences of the 5' halves of the genomes (4,400 nucleotides) of the first (S1) and last (S7) isolates were determined and compared with that of the EV30 Bastianni reference strain, also determined in this study. In genome regions P1 and P2, 101 variations were identified between the two isolates. Synonymous differences far outnumbered nonsynonymous differences. Amino acid changes affected both capsid and nonstructural polypeptides (particularly 2B). The VP1 nucleotide sequences of the seven isolates were determined to analyze genome evolution during the chronic infection. In the phylogenetic tree, the seven isolates were directly related to the prototype strain in an individual monophyletic group, strongly suggesting that the chronic infection in the child arose from a single persistent EV30 isolate. Four lineages were observed in the persistent isolates. Isolates S2, S4, S5, and S6 were close relatives of one another, whereas isolates S1 and S3 formed individual lineages. Isolate S7, distantly related to all other isolates, formed the fourth lineage. These findings suggest the quasispecies nature of the genomes of the seven sequential EV30 isolates. Grouping of persistent isolates on the basis of replicative capacities was consistent with phylogenetic relationships. Overall, the results indicate that genetically related EV30 variants with different replicative capacities coexisted in a carrier state, probably in the gastrointestinal tract, during the infection of the child.

5' Untranslated Regions↗
PubMed2000

Nosocomial transmission of echovirus 30: molecular evidence by phylogenetic analysis of the VP1 encoding sequence.

We investigated six cases of enterovirus infection in a neonatal unit. The index patient, a 5-day-old boy, was admitted with aseptic meningitis due to echovirus 30 (E30). Secondary infections with E30 occurred in five babies. Comparison of the complete VP1 sequences showed that the isolates recovered from the index patient and his mother were closely related to those recovered from the five babies with secondary infections, demonstrating a nosocomial transmission of the virus. In the phylogenetic tree reconstructed from the VP1 sequences, the isolates formed a monophyletic cluster related to an E30 strain collected in June 1997 during an outbreak of aseptic meningitis.

Adult↗
PubMed1999

[The re-emergence in 1997 of rubella infections during pregnancy. 11 cases in Clermont-Ferrand].

OBJECTIVE: Describe the clinical and laboratory features of rubella observed during the first semester of pregnancy in 11 patients in 1997. PATIENTS AND METHODS: Eleven pregnant women, aged 15-30 years, were referred to the Clermont-Ferrand University Hospital for suspected rubella. Four had had at least 1 prior pregnancy, none had been vaccinated. Rubella serology was obtained for all 11 patients and polymerase chain reaction viral amplification was performed on amniotic fluid in 9 cases. RESULTS: The virology laboratory identified 8 cases of primary rubella (2 prior to 12 weeks gestation) and 3 reinfections (1 prior to 12 weeks gestation). Fetal infection was evidenced in I gravida II patient at 17-18 weeks gestation. All pregnancies were continued to term and no case of congenital rubella malformation was observed. However specific IgM assays were performed at birth in 6 of the 11 infants and revealed infection in 3. CONCLUSION: These observations indicate that a local epidemic of rubella occurred in the general population. They illustrate the risk of a rubella epidemic in France and the lack of sufficient vaccination of the young adult population, finally they emphasize that current anti-rubella vaccination programs should be promoted.

Adolescent↗
PubMed1999

An outbreak due to echovirus type 30 in a neonatal unit in France in 1997: usefulness of PCR diagnosis.

Between February and August 1997, 53 patients with enterovirus meningitis were hospitalized in Clermont-Ferrand, France. All but one were children. Echovirus type 30 was involved in 70% of cases with identified serotype. The outbreak ceased on August 8. Two months later, a neonate was admitted to the neonatal unit with an echovirus type 30 meningitis thought to be acquired at delivery. Twenty days later a nosocomial outbreak of echovirus type 30 involving five neonates occurred. Two of them presented with meningitis and two with febrile seizure; One was asymptomatic. The retrospective examination of the maternal sera in a neutralization test, using the index case strain as a source of antigen, showed that none of the neonates was passively immunized before hospitalization. The use of genome detection in cerebrospinal fluid allowed rapid diagnosis and infection was contained by re-inforcing hygiene measures. Prospective examination of stools in the neonatal and paediatric units showed no further occurrences of the disease. No sporadic case was observed in the general population. Hence, nosocomial infections can occur a long time after an outbreak in the general population; rapid diagnosis with molecular tools is useful both for a definite diagnosis in patients already hospitalized, and to act as a rapid alert, even in intervals between seasonal outbreaks.

Adult↗
PubMed1997

Comparative sensitivities of Sabin and Mahoney poliovirus type 1 prototype strains and two recent isolates to low concentrations of glutaraldehyde.

Significant intratypic differences in the glutaraldehyde (GTA) sensitivity of echovirus isolates have been shown. While exploring ways to optimize the study of GTA sensitivity of enteroviruses, we also observed intratypic differences in poliovirus type 1 isolates collected in France. A suspension procedure was used for assessing the virucidal effect of GTA at low concentrations (< or = 0.10%) against purified viruses. Two recent isolates of poliovirus type 1 tested were first fully characterized by the PCR restriction fragment length polymorphism (RFLP) test. The RFLP pattern of clinical isolate 5617 was similar to that of poliovirus type 1 LS-c, 2ab (Sabin strain), confirming the vaccine origin of strain 5617. The RFLP pattern of strain 5915 recovered from sewage was different from that of the Mahoney strain, suggesting a genetic variation in this wild isolate. We then analyzed under the same controlled conditions the GTA sensitivities of both isolates and their respective prototype strains. The wild Mahoney and 5915 strains exhibited significantly lower sensitivities to GTA than did the vaccine Sabin and 5617 strains. The inactivation rates of clinical isolates 5617 and 5915 were very similar to those of their corresponding reference Sabin and Mahoney strains. Both the conformational structure of the capsid of each strain and the amino acid constitution of structural polypeptides could be involved in the variations observed. The relevance of our comparative sensitivity studies to standardization of virucidal tests is discussed.

Animals↗
PubMed1996

[Waldman's disease. Primary intestinal lymphangiectasis].

INTRODUCTION: Primary intestinal lymphangiectasias are often associated with lymphoedema. OBSERVATION: The diagnosis was performed at 4 months when Maxime presented with lymphoedema, diarrhea, hypoprotidemia and hypolipemia. Duodenum biopsies revealed intestinal lymphangiectasias. An hyperprotidic and low fat diet, medium chain triglyceride-supplemented and an elastic contention allowed a decline of the oedemas. DISCUSSION: We report one case of Waldman's disease. It shows very well the typical circumstances of diagnosis in this disease and the two types of oedema (lymphoedema and hypoprotidic oedema).

Dietary Proteins↗
PubMed1995

Complications of percutaneous liver biopsy in infants and children.

UNLABELLED: In this study, 144 consecutive percutaneous liver biopsies performed with a 1.6 mm Menghini needle, during a 2-year period were reviewed. All the children were aged under 15 years, 57 patients less than 1 year and 87 more than 1 year. All biopsies were adequate and the mean number of portal tracts examined was 17.6 per biopsy (14.3 in patients weighing less than 10 kg and 19.1 in the others). There were no deaths and we observed only bleeding complications. In patients with normal coagulation (128 cases), 1 bleeding requiring transfusion occurred; and in patients with abnormal coagulation (16 cases), we observed 2 bleeding cases requiring transfusion. CONCLUSION: Percutaneous liver biopsy can be performed with 1.6 mm needles in children. For increased safety, ultrasound-guided biopsies are recommended.

Adolescent↗
PubMed1994

Cathepsin D cytosolic assay and immunohistochemical quantification in human prostate tumors.

We quantified cathepsin D by immunoradiometric assay (IRMA) and quantitative immunohistochemistry in fifteen human prostate cancers, seventeen BPH, and nine normal prostates. The cytosolic cathepsin D concentration was higher in prostatic carcinoma (mean: 31.5 pmol/mg cytosol proteins; range: 10.2-66.2) than in normal prostate (16.0 pmol/mg cytosol proteins; 7.2-25.5; P = 0.01). Prostatic hyperplasia showed intermediate values (20.2 pmol/mg cytosol proteins; 7.6-33.9). Immunostaining of cathepsin D and prostatic acid phosphatase on serial frozen sections of prostate tissues was only observed in glandular epithelial cells. Immunostaining was quantified by computer-assisted image analysis as an quantitative immuno-cytochemical score (QIC score) expressed in arbitrary units (A.U.). QIC scores for cathepsin D were dispersed and had a tendency to be higher in benign prostatic hyperplasia (mean: 178.3 A.U.; range: 95-297) compared to normal prostate (85.2 A.U.; 2-173 P < 0.01) and prostatic carcinoma (90.0 A.U.; 21-179 P = 0.0002). Prostatic cathepsin D levels in cytosols or immunostaining sections were independent of other clinicobiological parameters.

Acid Phosphatase↗
PubMed1994

Replication of echo virus type 25 JV-4 reference strain and wild type strains in MRC5 cells compared with that of poliovirus type 1.

In echo virus type 25/JV-4 the shut off of host cell protein synthesis took significantly longer and the kinetics of the synthesis of viral proteins and viral RNA occurred much later than in the poliovirus. However, these characteristics impaired neither polyprotein processing nor virus production in the JV-4 strain. In contrast the two wild strains M.1262 and Th.222 had a lower virus yield than strain JV-4. The presence of a high Mr protein in the pattern of viral proteins of wild strains suggested that a defect in the polyprotein processing was responsible for the decreased virus yield. The infectious cycle of strain Th.222 differed from that of strains JV-4 and M.1262 in the rapid inhibition of host cell translation and the extent of viral protein synthesis. The sensitivity to actinomycin D was also investigated. Strain M.1262 was found to be insensitive. The virus yield of strains JV-4 and Th.222 was three- and fourfold lower respectively in the presence of actinomycin D. This sensitivity to the antibiotic was observed during viral RNA synthesis in strain JV-4 and during viral protein synthesis in strain Th.222. These results suggest that cellular factors are involved in the replication of echo virus type 25 strains in MRC5 cells.

Cell Line↗