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Biomedical subjects

D Capron

Publications and source records attributed to D Capron.

At least 19 recordsLinked to original sources
PubMed2007

Hepatitis C Virus p7 membrane protein quasispecies variability in chronically infected patients treated with interferon and ribavirin, with or without amantadine.

A clinical study was carried out to compare the response rate of two groups of non-responder (NR) hepatitis C virus (HCV) genotype 1 chronically infected patients treated with interferon and ribavirin, with or without amantadine. The viral load decreased more markedly in the group treated by tritherapy including amantadine, but the response rate at the end of treatment was not significantly different between bitherapy and tritherapy. As amantadine could have an antiviral effect on the ion channel activity of the p7 HCV protein, the p7 quasispecies was characterized by cloning and sequencing. Sequence data were analyzed to determine the pattern and significance of p7 genetic heterogeneity and a possible relationship with therapy. Subtype differences were confirmed between p7 HCV genotypes 1a and 1b, and quasispecies analysis showed a reduction of genetic diversity in subtype 1a, but not 1b, during tritherapy. However, the absence of changes at numerous positions, as well as the conservative changes at other positions, indicated the high conservation of the p7 structure. Residue His-17, proposed to interact with amantadine, was fully conserved in both subtypes 1a and 1b, independently of amantadine administration. In conclusion, although the analysis of the p7 sequences revealed a selective pressure during therapy, no specific residues appeared to be linked to the effect of amantadine on viral decline. These results suggest that the potential antiviral effect of amantadine might be non-specific and related to a reduction in endosomal acidification and therefore reduced viral entry of HCV via its pH-dependent pathway.

Adult↗
PubMed2005

Reverse cascade screening of newborns for hereditary haemochromatosis: a model for other late onset diseases?

BACKGROUND: Genetic testing can determine those at risk for hereditary haemochromatosis (HH) caused by HFE mutations before the onset of symptoms. However, there is no optimum screening strategy, mainly owing to the variable penetrance in those who are homozygous for the HFE Cys282Tyr (C282Y) mutation. The objective of this study was to identify the majority of individuals at serious risk of developing HFE haemochromatosis before they developed life threatening complications. METHODS: We first estimated the therapeutic penetrance of the C282Y mutation in people living in la Somme, France, using genetic, demographic, biochemical, and follow up data. We examined the benefits of neonatal screening on the basis of increased risk to relatives of newborns carrying one or two copies of the C282Y mutation. Between 1999 and 2002, we screened 7038 newborns from two maternity hospitals in the north of France for the C282Y and His63Asp (H63D) mutations in the HFE gene, using bloodspots collected on Guthrie cards. Family studies and genetic counselling were undertaken, based on the results of the baby's genotype. FINDINGS: In la Somme, we found that 24% of the adults homozygous for the C282Y mutation required at least 5 g iron to be removed to restore normal iron parameters (that is, the therapeutic penetrance). In the reverse cascade screening study, we identified 19 C282Y homozygotes (1/370), 491 heterozygotes (1/14) and 166 compound heterozygotes (1/42) in 7038 newborns tested. The reverse cascade screening strategy resulted in 80 adults being screened for both mutations. We identified 10 previously unknown C282Y homozygotes of whom six (four men and two women) required venesection. Acceptance of neonatal screening was high; parents understood the risks of having HH and the benefits of early detection, but a number of parents were reluctant to take the test themselves. Neonatal screening for HH is straightforward. Reverse cascade screening increased the efficiency of detecting affected adults with undiagnosed haemochromatosis. This strategy allows almost complete coverage for HH and could be a model for efficient screening for other late onset genetic diseases.

Adult↗
PubMed2004

[Advances in iron metabolism: a transition state].

PURPOSE: Advances towards the understanding of gene regulation and protein function recently discovered through iron metabolism disorders are the subject of this review. CURRENT KNOWLEDGE AND KEY POINTS: Within a few years the discovery of genes that determine heritable defects of cellular iron uptake or regulation in mice as in humans have provided new insights for investigation into iron metabolism pathways. FUTURE PROSPECTS AND PROJECTS: It is still unclear how connections are made between new proteins in iron uptake, trafficking and regulation of iron homeostasis. Gene expression studies using microarrays technology in different iron conditions should help to explore iron homeostasis further.

Absorption↗
PubMed2004

[Molecular basis in hereditary haemochromatosis].

PURPOSE: Recent discoveries in molecular mechanisms of iron metabolism have changed the classical view of hereditary iron overload conditions. We present natural mutations in newly discovered genes and related phenotypes observed in patients with different form of haemochromatosis. CURRENT KNOWLEDGE AND KEY POINTS: Most haemochromatosis patients are homozygous for the C282Y mutation in the HFE gene. Ferroportin, TFR2, hemojuvelin and hepcidin mutations also cause iron overload. Recent data support the hypothesis that haemochromatosis should no longer be considered a monogenic disease but rather an oligogenic disorder. Several results suggest that haemochromatosis could result from digenic inheritance of mutations in HFE and HAMP. FUTURE PROSPECTS AND PROJECTS: Other modifier genes probably influence penetrance in C282Y homozygous patients. Such genes could enhance or reduce the phenotypic expression in various iron overload conditions.

Hemochromatosis↗
PubMed2003

A targeted approach significantly increases the identification rate of patients with undiagnosed haemochromatosis.

OBJECTIVE: To determine the optimal means of identifying patients with undiagnosed haemochromatosis. DESIGN: Case-control study where cases are defined by the presence of specific clinical diagnoses or symptoms. SETTING: Primary care patients were recruited from three Oxfordshire practices and secondary care patients were recruited from those patients attending specialist clinics in Amiens University Hospital. SUBJECTS: A total of 569 patients recruited via hospital clinics and 60 primary care patients (recruited from 4022 consultations) presenting with the following haemochromatosis associated conditions, diabetes, arthralgia/chronic fatigue, osteoporosis or arthropathy were studied. The control group, a total of 991 healthy volunteers, were recruited through a Health Appraisal Centre. Patients and controls were included in the study if they or their family members had not previously been diagnosed with hereditary haemochromatosis. MAIN OUTCOME MEASURES: Serum ferritin concentration, transferrin saturation (Tsat) and presence of HFE mutations, C282Y and H63D. The check-up in controls consisted of a questionnaire, clinical examination, biochemical tests and screening for the presence of the C282Y and H63D mutations. RESULTS: Patient groups presenting with unstable diabetes or chronic fatigue and arthralgia together with a raised serum ferritin concentration showed an enrichment in the haemochromatosis-associated genotype HH/YY, odds ratio (OR) = 40.1, confidence interval (CI) = 8.0-202.1 and OR = 103, CI = 22.9-469.7, respectively. CONCLUSION: Patients presenting to hospital clinics with haemochromatosis associated conditions should be screened biochemically for iron overload. Only those with a serum ferritin >300 microg L-1 or Tsat >40% should subsequently go on to be genotyped for HFE mutations. The patients at greatest risk of having undiagnosed haemochromatosis are those presenting with unstable diabetes, or fatigue and/or arthralgia in the absence of any other explanation.

Adult↗
PubMed1999

Hepatitis C virus infection risk factors in patients admitted in hospital emergency departments in Picardy. Value of oriented screening based on recommendations of the 'Direction Générale de la Santé'.

OBJECTIVE AND DESIGN: Oriented hepatitis C virus (HCV) screening on the basis of transfusion, previous or current parenteral drug addiction, invasive procedures, and in family members of patients with hepatitis C, was recommended in France by the 'Direction Générale de la Santé' (DGS). The aim of this study was to estimate the frequency of these risk factors in patients admitted in hospital emergency departments in Picardy. METHODS: Between 1 June and 31 July 1996, physicians of the emergency units of seven hospitals in Picardy were asked to question admitted patients about risk factors mentioned in the DGS recommendations, and to suggest a screening test when at least one of these risk factors was present. RESULTS: Among 1648 patients, 68.7% had at least one of these risk factors. Screening was accepted by 723 patients, 58.7% of those with at least one risk factor, and more than 70% of those with history of transfusion and/or drug addiction. It was immediately performed in 451, and 2.4% had anti-HCV antibodies. The prevalence of anti-HCV antibodies was 1.5% in patients without history of transfusion or drug addiction and 7.9% in those with at least one of these two risk factors. CONCLUSION: Oriented screening based on transfusion or drug addiction history seems to have better efficiency than the screening policy recommended by the DGS. Poor reliability of answers about medical history was observed probably because of stress related to emergency circumstances. A screening test proposed to patients with these major risk factors by their usual physician would be probably more efficient.

Aged↗
PubMed1998

Hepatic nodules as single organ involvement in an adult with Langerhans cell granulomatosis. A case report.

Liver involvement manifesting as hepatomegaly in Langerhans cell granulomatosis (LCG) is well known, but the definitive diagnosis is generally possible because other organs are involved. We report a 41-year-old white man who presented with cholestasis and liver nodules as an isolated hepatic LCG. The diagnosis of LCG was suspected based on routine histopathologic examination; the diagnosis became definitive 4 years later when Birbeck granules were found in the liver, an uncommon occurrence in this organ. This is an unusual presentation of a benign form of this disease and one of the first that reported Birbeck granules in the liver.

Adult↗
PubMed1998

[Adult idiopathic ductopenia. 1 case].

Idiopathic adult ductopenia is very rare. We report one case in a 30-year-old man, whose clinical course was characterized by jaundice and pruritus. Laboratory investigations revealed cholestasis and polyclonal hypergammaglobulinemia. Serum antinuclear, antimitochondrial, and anti-smooth muscle antibodies and serological markers for viral hepatitis were negative. Endoscopic retrograde cholangiography showed no liver or biliary tract abnormalities. Histological examination of a liver specimen showed a vanishing bile duct syndrome and moderate portal infiltration with lympho-histiocytic cells; there were no granulomas. Liver transplantation was performed due to rapid development of cirrhosis. The differential diagnosis of idiopathic adult ductopenia with small duct primary sclerosing cholangitis, auto-immune cholangiopathy, and non syndromic paucity of intrahepatic bile ducts is unclear.

Adult↗
PubMed1997

Mutations of hepatitis C virus 1b NS5A 2209-2248 amino acid sequence do not predict the response to recombinant interferon-alfa therapy in French patients.

BACKGROUND/AIMS: Studies of HCV quasispecies during interferon treatment have shown the selection of resistant clones. Enomoto et al. have defined the interferon sensitivity-determining region in an amino acid stretch of the HCV-1b NS5A region. Patients with a mutant strain before treatment were complete responders, whereas those with wild-type HCV-J strain were resistant to interferon. The same region was studied in HCV isolates of French patients. METHODS: Forty-three HCV-1b chronically infected patients, consisting of 26 non-responders and 17 complete responders to interferon-alfa treatment (3 MUI tiw for 6 months), were included retrospectively. We directly sequenced the NS5A(2209-2248) HCV region of these patients before treatment. The viral load could be obtained from six complete responders and 15 non-responders. RESULTS: We detected wild-type and intermediate strains, but only two mutant strains were present. One of them was found in a non-responder. In three complete responders, we found a wild-type strain. The distribution of the various strains was rather different from that found in Japan. Before treatment, the viral load was lower in complete responders (p=0.01). CONCLUSIONS: Only two mutant strains were detected in our study. This could partially explain the low response rate to interferon treatment of French HCV-1b-infected patients, although the dose regimen was lower than in Japanese studies. Also, wild-type strains were found in some complete responders, and no correlation was determined between the mutation number in the NS5A(2209-2248) region and response to alfa interferon therapy. This may be related to epidemiological differences between HCV-1b strains present in France and those in Japan. Searching for the mutant NS5A pattern before treatment does not appear to be useful in French patients as it is too uncommon.

Adult↗
PubMed1997

Comparison of hepatitis C virus serotyping and genotyping in French patients.

BACKGROUND: Hepatitis C virus (HCV) serotyping has been proposed as an alternative assay to determine the respective genotype as it is more rapid, simple and less expensive than polymerase chain reaction (PCR) based typing methods. OBJECTIVES: A serotyping assay was compared with a genotyping assay to determine the infecting hepatitis C virus type in chronically HCV infected patients eligible for interferon therapy. STUDY DESIGN: An enzyme immunoassay (HC01, Murex) was tested to identify HCV types 1, 2 and 3 specific antibodies in 134 PCR-positive sera from chronically infected patients which had been previously genotyped by a reverse hybridization assay (INNO-LiPA HCV I, Innogenetics). Respectively nine and seven sera were from HIV-seropositive and hemodialysis patients. Unreactive sera and those with discrepant results were retested by a new version (HC02) extended to types 4, 5 and 6. RESULTS: The distribution frequency of HCV genotypes was subtype 1a, 16.4%; subtype 1b, 46.3%; subtype 2a, 7.5%; subtype 3a, 20.9%; type 4, 4.5%; type 5, 0.7%; and co-infections, 3.7%. Among all the patients, 95% were of type 1, 2 or 3. The antibody reactivities of hemodialysis (1/7; P < 0.05) and HIV-seropositive patients (4/9; P = 0.06) were lower than for the patients seen at the hepatology unit (87/118). For these latter patients, the serotyping assay was interpretable in 71% and concordant in 64% of the samples with the genotyping assay. Out of the 84 samples with interpretable results, 75 sera were correctly serotyped (89% specificity). The two mixed results obtained by serotyping did not correspond to genotype co-infections (n = 3) and reciprocally. Six discrepancies were ruled out by the new assay, but the 2 untypeable sera remained unsolved, and four out of six sera with genotype 4 were serotyped as type 5. CONCLUSIONS: Serotyping could be an attractive approach if the reactivity was improved and the subtyping possible.

Adult↗
PubMed1997

Cirrhosis: a new, but expected cause of biliary sludge.

BACKGROUND/AIMS: Biliary sludge is increasingly recognized as a natural stage in gallstone formation. Logically, cirrhosis, a well-documented cause of black pigment cholelithiasis, should be another condition predisposing to the development of sludge. The aim of this study was to assess the prevalence of biliary sludge in an unselected population and to test the hypothesis that cirrhosis could be one of the causes of sludge. METHODS: We reviewed the clinical findings and ultrasonograms of 2138 patients, hospitalized or not, consecutively seen in our department between January 1993 and December 1994. Sonograms showing biliary sludge mixed with stones were excluded. Three hundred and eighty-eight of the 2138 were cirrhotic patients. RESULTS: The overall prevalence of biliary sludge was 4%. Sludge was found in 44 of 388 (11%) of the cirrhotic patients (alcoholism, n = 39; chronic viral B hepatitis, n = 3; hemochromatosis, n = 1; and cryptogenic, n = 1), compared with 42 of 1750 (2%) noncirrhotic patients (p < 0.000001). Thirteen cirrhotic patients received intravenous alimentation for 2 to 17 days, 8 were given somatostatin for variceal bleeding, and 7 have previously had 1 to 5 sessions of endoscopic sclerotherapy of esophageal varices with polidocanol. CONCLUSIONS: This study convincingly demonstrates that cirrhosis must be added to the growing list of conditions associated with biliary sludge.

Adult↗
PubMed1997

[Research of type 1, 2 and 3 hepatitis C virus specific antibodies in relation to the viral genotype in chronically infected patients].

The determination of the viral genotype in chronically HCV infected patients is used as an epidemiologic tool, a predictive marker of the evolution of the disease and especially of the response to the interferon alfa therapy. Its determination needs an amplification of the selected genomic region and remains expensive. Thus an indirect determination of the genotype has been proposed using the characterization of type-specific antibodies. In 101 chronically HCV infected patients, a serologic method specific for HCV type 1, 2 and 3 has been evaluated in relation to the genotyping one. The test was interpretable in 64 sera and in agreement with the genotyping method in 92% of the samples. The reactivity of the test was lower in hemodialysis and IVDUs patients (p < 0.02). The mixed results obtained by the serologic typing method were not in agreement with the results of the genotyping coinfections. We could not differentiate the possible past infections from the cross-reactivities of the test. The serotyping methods was simple and rapid, allowing generally a deduction of the viral genotype. It could be an attractive approach if the reactivity was improved and the subtyping was possible.

Adult↗
PubMed1996

[Seroprevalence of viral hepatitis A in at the Amiens University Hospital].

OBJECTIVES AND METHODS: The epidemiology of viral hepatitis A has been evolved in the past few years, resulting in an increasing number of people without immunity to this virus. Health care workers are usually considered to be a group at risk of contamination by hepatitis A. A sero-epidemiologic study was performed in 525 members of the Pediatry, Gastroenterology, Internal medicine, Digestive radiology, kitchen and maintenance department staffs in the Amiens University Hospital. The aim of this study was to describe the epidemiology of hepatitis A and to estimate the level of occupational hazard it represents in the hospital. RESULTS: Age, low education level, country of origin in an endemic region and more than 2 siblings or children were significantly associated with the presence of anti-HAV antibodies. The prevalence of 50% was similar to that observed in other hospitals, but lower than that found in the general population. Seroprevalence was not higher in departments exposed to stools (Pediatry, Digestive endoscopy and laboratories) than in others. A higher rate of seroprevalence was observed in kitchen and maintenance staffs than in medical, laboratory and Radiology staffs, in Internal medicine than in the Gastroenterology Department, and in the laboratory than in Radiology Department. These differences disappeared after adjustment for extraprofessional parameters which appeared to be most important for hepatitis A epidemiology. CONCLUSIONS: The hospital occupational hazard for hepatitis A virus did not seem higher than that observed in the general population.

Adult↗
PubMed1996

[Helicobacter pylori and gastroduodenal lesions in 547 symptomatic young adults].

OBJECTIVES: Helicobacter pylori (H. pylori) is involved in the pathogenesis of gastric inflammatory disorders. Both antral chronic gastritis and H. pylori infection prevalence increase with age. The aim of the study was to assess the prevalence of H. pylori infection in young adults and to study the relationship between endoscopical and histological features and H. pylori infection. METHODS: The study concerned 547 young patients (age: 18-25 years), undergoing endoscopy for upper gastrointestinal symptoms. The severity and the activity of chronic gastritis was graded by histological examination of antral biopsies. The diagnosis of H. pylori infection was based on histology and culture or urease test. RESULTS: Fifty-three percent of the patients had a normal endoscopy; 44 ulcers were found: 34 duodenal ulcers and 10 gastric ulcers. H. pylori infection was detected in 34% of cases. The prevalence of H. pylori infection was 29.8% in non-ulcer patients, 50% in gastric ulcers and 91% in duodenal ulcers (P < 0.01). Duodenal ulcer, aspect of antral mosaic mucosa and nodular gastritis, were closely related to the presence of H. pylori. There was a significant relationship between H. pylori infection and both the severity (P < 0.01) and the activity (P < 0.01) of the antral chronic gastritis. The prevalence of follicular gastritis was 22% : it was present in 60% of H. pylori positive patients and 2.4% of H. pylori negative patients. H. pylori infection was more frequent in patients from Africa than in Europeans (P < 0.01). There was no significant association between H. pylori infection and different types of diets, settlements (rural vs urban) or symptoms. CONCLUSION: These results show that in the young population studied, duodenal ulcer, nodular gastritis, antral mosaic mucosa, active chronic gastric and follicular gastritis are closely related to H. pylori infection. They suggest that in the subgroup of non ulcer symptomatic patients, H. pylori prevalence is higher than in the general population.

Adolescent↗