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Dive into the research topics where Michèle Chevallier is active.

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Featured researches published by Michèle Chevallier.


The New England Journal of Medicine | 1995

A COMPARISON OF THREE INTERFERON ALFA-2B REGIMENS FOR THE LONG-TERM TREATMENT OF CHRONIC NON-A, NON-B HEPATITIS. MULTICENTER STUDY GROUP

Thierry Poynard; Pierre Bedossa; Michèle Chevallier; Philippe Mathurin; Catherine Lemonnier; Christian Trepo; Patrice Couzigou; Jean Louis Payen; Marc Sajus; Jean Marc Costa; Michel Vidaud; Jean Claude Chaput

BACKGROUND We studied the effects of long-term treatment with interferon on histologic features of the liver and serum alanine aminotransferase concentrations in patients with chronic non-A, non-B hepatitis. METHODS Consecutive patients who met the inclusion criteria were enrolled in the study. The diagnosis of chronic non-A, non-B hepatitis was established on the basis of the liver-biopsy findings and an abnormal serum alanine aminotransferase value (greater than 1.5 times the normal value) for at least one year. All patients were treated for six months with 3 million units of interferon alfa-2b given subcutaneously three times a week and were then randomly assigned to the same treatment for an additional 12 months (group 1), a regimen of 1 million units three times a week for 12 months (group 2), or no further treatment (group 3). Patients in group 3 who had elevated serum alanine aminotransferase concentrations for three consecutive months underwent the initial regimen once again. Follow-up continued for two years after the discontinuation of treatment. Histologic improvement was defined as a decrease of at least one grade in the score for necroinflammatory activity (0, no activity; 1, mild; 2, moderate; or 3, severe) between the first liver biopsy and a biopsy performed at 18 months. RESULTS Of the 329 patients initially treated, 303 were randomized: 103 to group 1, 101 to group 2, and 99 to group 3. Of the 286 patients tested, 252 (88.1 percent) had antibodies to hepatitis C virus. In an intention-to-treat analysis, 46 of the patients in group 1 (44.7 percent) had normal serum alanine aminotransferase values at 18 months, as compared with 27 of the patients in group 2 (26.7 percent, P = 0.008) and 30 of those in group 3 (30.3 percent, P = 0.04). Between 19 and 42 months, 23 of the patients in group 1 (22.3 percent) continued to have normal serum alanine aminotransferase values (measured every six months), as compared with 10 of the patients in group 2 (9.9 percent, P = 0.02) and 8 of those in group 3 (8.1 percent, P = 0.005). Among the 176 patients with repeated liver biopsies at 18 months, more patients in group 1 had improved histologic-activity scores (69.6 percent) than in group 2 (47.6 percent, P = 0.02) or group 3 (38.6 percent, P < 0.001). CONCLUSIONS Among patients with chronic non-A, non-B hepatitis, a regimen of 3 million units of interferon alfa-2b given three times a week for 18 months produced better histologic findings and serum alanine aminotransferase values than regimens involving a lower dose or a shorter duration of treatment.


Journal of Computer Assisted Tomography | 2001

Small nodule detection in cirrhotic livers : Evaluation with US, spiral CT, and MRI and correlation with Pathologic examination of explanted liver

Agnès Rode; Brigitte Bancel; Philippe Douek; Michèle Chevallier; Valérie Vilgrain; Georges Picaud; Luc Henry; Françoise Berger; Thierry Bizollon; Jean-Louis Gaudin; Christian Ducerf

Purpose The purpose of this work was to evaluate the detection and characterization of nodules ≥8 mm and small hepatocellular carcinomas (HCCs) in liver cirrhosis. Method Pathologic examination and results of US, helical CT, and dynamic MRI with gadolinium were compared after orthotopic liver transplantation (OLT) of 43 cirrhotic patients. Nodules were classified as macroregenerative nodules (MRNs), borderline nodules (BNs), and HCC. Results Pathologic examination classified 69 nodules: 50 MRNs, 6 BNs, and 13 HCCs. Sensitivities of MRN, BN, and HCC detection were, respectively, for US imaging 2% (1/50), 33.3% (2/6), and 46.2% (6/13); for helical CT 2% (1/50), 50% (3/6), and 53.8% (7/13); and for MRI 42% (21/50), 50% (3/6), and 76.9% (10/13). MRI detected 21 MRNs. They presented on T1/T2-weighted images as hyperintense/hypointense (n = 8), hyperintense/isointense (n = 7), hypointense/hypointense (n = 4), hypointense/isointense (n = 1), and hypointense depicted only on echo planar imaging (n = 1). The three detected BNs were hyperintense/hypointense nodules. The 10 detected HCCs appeared hyperintense/isointense (n = 7), hyperintense/hypointense (n = 2), and hypointense/isointense (n = 1). None of the MRNs but eight HCCs and one BN were enhanced after gadolinium injection. Conclusion Contrast-enhanced MRI is the most sensitive technique for detecting liver nodules. No MR signal intensity pattern characteristic of small HCCs enables differentiation from benign nodules, however. Gadolinium enhancement is the most sensitive and specific characteristic of HCC.


Gastroenterology | 1991

Comparison of 1 or 3 MU of interferon alfa-2b and placebo in patients with chronic non-A, non-B hepatitis

Xavier Causse; Hubert Godinot; Michèle Chevallier; P. Chossegros; Fabien Zoulim; Denis Ouzan; Jean-Paul Heyraud; Thierry Fontanges; Janice K. Albrecht; Carlton Meschievitz; Christian Trepo

Ninety patients with histologically documented chronic non-A, non-B hepatitis were randomly allocated to receive SC injections of placebo or of 1 or 3 MU of recombinant interferon alfa-2b three times weekly for 24 weeks. Complete normalization of alanine aminotransferase levels occurred posttreatment in 43.3% of patients receiving 3 MU, in 20% of those receiving 1 MU, and in 6.7% of untreated patients (P less than 0.0005 vs. those treated with 3 MU). Alanine aminotransferase normalization was sustained for 6 months after therapy in 13.3% of the patients treated with 3 MU and in 3.3% of those given 1 MU or placebo. The decline of alanine aminotransferase levels following interferon therapy showed independent, positive correlations with female sex (P less than 0.03) and younger age (P less than 0.05). The Knodells fibrosis score was strongly positively correlated with age (P less than 0.0001). It is concluded that 3 MU of interferon is a more effective dose than 1 MU for controlling disease activity in non-A, non-B chronic hepatitis patients. Women and younger and noncirrhotic patients are more likely to respond.


Journal of Hepatology | 2000

Rapid detection of genotypes and mutations in the pre-core promoter and the pre-core region of hepatitis B virus genome: correlation with viral persistence and disease severity

Cécile Grandjacques; Pierre Pradat; Lieven Stuyver; Michèle Chevallier; Philippe Chevallier; Christian Pichoud; Mireille Maisonnas; Christian Trepo; Fabien Zoulim

BACKGROUND/AIMS We aimed to clarify the clinical relevance of hepatitis B virus pre-core mutant detection in patients with chronic hepatitis B using a newly developed assay. METHODS Viral genotypes and pre-core mutations were studied in relation to viral persistence and liver disease severity using INNO-LiPA methodology. The study group included 151 patients with chronic hepatitis B, 85 positive for HBeAg (group I) and 66 positive for anti-HBe (group II). RESULTS The prevalence of viral genotypes in group I was: 64% A, 1% B, 15% C, 19% D, 0% E, 0% F and in group II: 39% A, 0% B, 2% C, 56% D, 2% E, 2% F (p<0.001). The prevalence of mutations at pre-core codon 28 (M2) was lower in group I (5%) than in group II (64%) (p<0.001). The prevalence of pre-core promoter mutations was also lower in group I (21%) than in group II (61%) (p<0.001). M2 mutations were more frequently detected in genotype D than in genotype A (p<0.001), while the other mutations were not influenced by viral genotype. Serum HBV DNA levels were significantly lower in group II versus group I (p<0.001), and in patients with any of the pre-core mutations versus wild-type sequence (p<0.01). Although cirrhosis was more frequent in group II (37%) versus group I (22%) and in patients with either one of the pre-core mutation (31%) versus wild-type sequence (25%), there was no statistical difference in liver severity assessed by ALT levels and Knodell score. CONCLUSION Pre-core mutants, whose molecular pattern is strongly dependent on viral genotypes, are associated with viral persistence in anti-HBe positive patients with ongoing chronic hepatitis B. The availability of this rapid assay should allow a precise monitoring of viral pre-core mutants during the course of chronic hepatitis B.


Hepatology | 2011

Impact of patatin‐like phospholipase‐3 (rs738409 C>G) polymorphism on fibrosis progression and steatosis in chronic hepatitis C

Eric Trepo; Pierre Pradat; Andrej Potthoff; Yukihide Momozawa; Eric Quertinmont; Thierry Gustot; Arnaud Lemmers; Pascale Berthillon; Leila Amininejad; Michèle Chevallier; Jerome Schlue; Hans Kreipe; Jacques Devière; Michael P. Manns; Christian Trepo; John J. Sninsky; Heiner Wedemeyer; Denis Franchimont; Christophe Moreno

Only 20% of patients with chronic hepatitis C (CHC) will develop cirrhosis, and fibrosis progression remains highly unpredictable. A recent genome‐wide association study identified a genetic variant in the patatin‐like phospholipase‐3 (PNPLA3) gene (rs738409 C>G) associated with steatosis that was further demonstrated to influence severity of fibrosis in nonalcoholic fatty liver disease. The aim of this study was to assess the impact of this polymorphism on histological liver damage and response to antiviral therapy in CHC. We recruited 537 Caucasian CHC patients from three European centers (Brussels, Belgium [n = 229]; Hannover, Germany [n = 171]; Lyon, France [n = 137]); these patients were centrally genotyped for the PNPLA3 (rs738409 C>G) polymorphism. We studied the influence of rs738409 and other variants in the PNPLA3 region on steatosis and fibrosis assessed both in a cross‐sectional and longitudinal manner. Seven other variants previously associated with fibrosis progression were included. Finally, we explored the impact of rs738409 on response to standard antiviral therapy using the interferon lambda 3 (IL28B) [rs12979860 C>T] variant both as a comparator and as a positive control. After adjustment for age, sex, body mass index, alcohol consumption, and diabetes, rs738409 mutant G allele homozygote carriers remained at higher risk for steatosis (odds ratio [OR] 2.55, 95% confidence interval [CI] 1.08‐6.03, P = 0.034), fibrosis (OR 3.13, 95% CI 1.50‐6.51, P = 0.002), and fibrosis progression (OR 2.64, 95% CI 1.22‐5.67, P = 0.013). Conversely, rs738409 was not independently associated with treatment failure (OR 1.07, 95% CI 0.46‐2.49, P = 0.875) and did not influence clinical or biological variables. Conclusion: The PNPLA3 (rs738409 C>G) polymorphism favors steatosis and fibrosis progression in CHC. This polymorphism may represent a valuable genetic predictor and a potential therapeutic target in CHC liver damage. (HEPATOLOGY 2011;)


Journal of Hepatology | 2001

Transglutaminase-mediated cross-linking is involved in the stabilization of extracellular matrix in human liver fibrosis

Pascale Grenard; Solange Bresson-Hadni; Saı̈d El Alaoui; Michèle Chevallier; Dominique A. Vuitton; Sylvie Ricard-Blum

BACKGROUND/AIMS Lysyl oxidase-mediated cross-linking contributes to the stabilization of collagen in liver fibrosis. We have investigated transglutaminase-mediated cross-linking, to determine if it participates in the stabilization of extracellular matrix in human liver fibrosis. METHODS Transglutaminase activity was assessed in vitro by incorporation of biotinylated amine into liver proteins. The product of the transglutaminase-catalyzed cross-linking reaction, Nepsilon(gamma-glutamyl)lysine, and the extracellular proteins cross-linked by it, were localized by immunohistochemistry in fibrotic livers. The cross-linked complexes were extracted from liver tissue, immunopurified and characterized by Western blot. RESULTS Transglutaminase, detected by immunohistochemistry, Western blot and by enzymatic activity, was found in higher amounts in fibrotic than in normal liver. The Nepsilon(gamma-glutamyl)lysine cross-link, undetectable in normal liver, was present extracellularly in fibrotic liver, where it was co-distributed with osteonectin, mostly in inflammatory areas submitted to an intense remodeling. Cross-linking of osteonectin by transglutaminase was confirmed by Western blot. In parasitic fibrosis transglutaminase also originates from the parasite. CONCLUSIONS Transglutaminase-mediated cross-linking occurs in liver extracellular matrix during the early, inflammatory, stage of liver fibrosis, whereas cross-linking by pyridinoline occurs mostly later in the fibrotic process. This could lead to the development of new anti-fibrotic treatments targeted to a specific stage of fibrosis.


Antimicrobial Agents and Chemotherapy | 2000

Characterization of the Antiviral Effect of 2′,3′-Dideoxy-2′, 3′-Didehydro-β-l-5-Fluorocytidine in the Duck Hepatitis B Virus Infection Model

Franck Le Guerhier; Christian Pichoud; Sylviane Guerret; Michèle Chevallier; Catherine Jamard; Olivier Hantz; Xiuyan Li; Shu-Hui Chen; Ivan King; Christian Trepo; Yung-Chi Cheng; Fabien Zoulim

ABSTRACT A novel l-nucleoside analog of deoxycytidine, 2′,3′-dideoxy-2′,3′-didehydro-β-l-5-fluorocytidine (β-l-Fd4C), was recently shown to strongly inhibit hepatitis B virus (HBV) replication in the 2.2.15 cell line. Therefore, its antiviral activity was evaluated in the duck HBV (DHBV) infection model. Using a cell-free system for the expression of the DHBV polymerase, β-l-Fd4C-TP exhibited a concentration-dependent inhibition of dCTP incorporation into viral minus-strand DNA with a 50% inhibitory concentration of 0.2 μM which was lower than that of other tested deoxycytidine analogs, i.e., lamivudine-TP, ddC-TP, and β-l-FddC-TP. Further analysis showed that β-l-Fd4C-TP is likely to be a competitive inhibitor of dCTP incorporation and to cause premature DNA chain termination. In primary duck hepatocyte cultures infected in vitro, β-l-Fd4C administration exhibited a long-lasting inhibitory effect on viral DNA synthesis but could not clear viral covalently closed circular DNA (CCC DNA). Results of short-term antiviral treatment in experimentally infected ducklings showed that β-l-Fd4C exhibited the most potent antiviral effect, followed by β-l-FddC, lamivudine, and ddC. Longer administration of β-l-Fd4C induced a sustained suppression of viremia (>95% of controls) and of viral DNA synthesis within the liver. However, the persistence of trace amounts of viral CCC DNA detected only by PCR was associated with a recurrence of viral replication after drug withdrawal. In parallel, β-l-Fd4C treatment suppressed viral antigen expression within the liver and decreased intrahepatic inflammation and was not associated with any sign of toxicity. Our data, therefore, demonstrate that in the duck model of HBV infection, β-l-Fd4C is a potent inhibitor of DHBV reverse transcriptase activity in vitro and suppresses viral replication in the liver in vivo.


Liver International | 2007

Progression to cirrhosis in hepatitis C patients: an age-dependent process

Pierre Pradat; Nicolas Voirin; Hans L. Tillmann; Michèle Chevallier; Christian Trepo

Background: Age at infection is known to be associated with disease progression rate in hepatitis C virus (HCV) infected patients. The aim of this study was to assess when cirrhosis is expected to occur according to host and viral factors.


Journal of Hepatology | 2011

Pharmacological inhibition of Frizzled-7 displays anti-tumor properties in hepatocellular carcinoma

Sarah B. Nambotin; Lydie Lefrancois; Xavier Sainsily; Pascale Berthillon; Miran Kim; Jack R. Wands; Michèle Chevallier; Pierre Jalinot; Jean-Yves Scoazec; Christian Trepo; Fabien Zoulim; Philippe Merle

BACKGROUND & AIMS We previously reported the frequent overexpression of the FZD7 membrane receptor in hepatocellular carcinoma (HCC) and its role for controlling cancer phenotype. Herein, this study aimed at assessing the anticancer properties of compounds inhibiting FZD7 activity by disrupting its binding with the cytosolic Dishevelled (DVL) adaptator. METHODS We have designed small interfering peptides (RHPDs) that are able to enter within cells and to competitively antagonize the binding of FZD7 to the PDZ domain of DVL. Their anti-neoplastic properties were assessed in vitro on a panel of human HCC cell lines and in vivo on the SV40-TAg transgenic mouse model of HCC. RESULTS We have shown that RHPDs decrease cell viability via apoptosis depending on their affinity for PDZ, with a therapeutic index between cancerous and non-cancerous cells. RHPD properties were linked to β-catenin degradation and PKCδ activation. In transgenic mice, intra-tumor injection of RHPDs inhibited HCC progression. CONCLUSIONS We have completed a proof-of-concept showing that in vitro and in vivo the pharmacological inhibition of FZD7 displays anti-cancerous properties against HCC. The mechanisms can involve β-catenin and PKCδ modulations. Further studies are warranted to design protocols showing the compatibility with systemic in vivo applications.


Virchows Archiv | 1992

Cell populations in the lesion of human cutaneous leishmaniasis: a light microscopical, immunohistochemical and ultrastructural study.

Philippe Esterre; J.P. Dedet; C. Frenay; Michèle Chevallier; Jean-Alexis Grimaud

To characterize the in situ cellular immune response in localized cutaneous leishmaniasis (LCL), the authors studied frozen skin biopsies from 50 patients with LCL due toLeishmania braziliensis guyanensis. A panel of 31 monoclonal antibodies was used, which defined the number and distribution of inflammatory cell subsets. Skin inflammatory infiltrates were composed of T cells (with a local CD4/CD8 ratio of 1.05±0.7 vs 1.48±0.3 in peripheral blood), macrophages and a smaller number of B cells, natural killer cells and granulocytes. Most of the T cells expressed activation markers (interleukin-2 and transferrin receptors, HLA-DR+) and an increase in T-cell-receptorγδ expression was noted. Analysis of the CD4+ subpopulations with newly available reagents showed that helper T cells (CD4+CD45RO+) exceeded the suppressor/inducer subset (CD4+CD45RA+) by 1.4∶1. There were no differences between local immune variables from patients with primary infection (45 patients) and those with recurrence (5). In 7 patients, biopsies were analysed before and 1 month after specific treatment, and did not show significant differences except for a small increase of dermal CD1a+ (Langerhans) cells/mm2. The observed pattern of cellular skin infiltration suggests an immune-mediated tissue injury including T-cell-mediated cytotoxicity and delayed hypersensitivity reactions in addition to direct parasitic action.

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Liana Codes

Federal University of Bahia

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