PubMed Health⌕ Search

Biomedical subjects

O Rosmorduc

Publications and source records attributed to O Rosmorduc.

18 recordsLinked to original sources
PubMed2005

HHV-6-related acute liver failure in two immunocompetent adults: favourable outcome after liver transplantation and/or ganciclovir therapy.

Fulminant hepatitis of unknown origin remain a significant cause of mortality, for which liver transplantation is often considered as the only therapeutic option. In retrospective studies, human herpesvirus 6 (HHV-6) infections have been associated with such diseases, but the diagnosis of HHV-6 infection of the liver is rarely established during the acute phase of liver failure. Using real-time polymerase chain reaction (PCR), we diagnosed two cases of severe acute liver failure (ALF) related to HHV-6 occurring in immunocompetent young adults. Both cases had a favourable outcome, one after valganciclovir therapy, one after liver transplantation associated with ganciclovir. Viral origin was evidenced in each case by the detection of high amounts of HHV-6 DNA in liver tissue by the PCR assay. The decrease of intrahepatic viral load after therapeutic intervention was also monitored by quantitative PCR and paralleled in the two cases the clinical improvement. Diagnosis of HHV-6 infection must be systematically evoked in case of unexplained ALF, since it might lead to specific therapeutic interventions, in addition of liver transplantation.

Administration, Oral↗
PubMed2004

Gemcitabine combined with oxaliplatin (GEMOX) in advanced biliary tract adenocarcinoma: a GERCOR study.

BACKGROUND: Since gemcitabine-oxaliplatin (GEMOX) has been used in pancreatic adenocarcinoma, we studied its activity and tolerability in advanced biliary tract adenocarcinoma (ABTA). PATIENTS AND METHODS: Consecutive adult patients with confirmed ABTA were recruited from four centers. Those in group A had performance status (PS) 0-2, bilirubin <2.5x normal and received GEMOX as first-line chemotherapy. Those in group B had PS >2 and/or bilirubin >2.5x normal and/or prior chemotherapy. All received gemcitabine 1000 mg/m2 as a 10 mg/m2/min infusion on day 1, followed by oxaliplatin 100 mg/m2 as a 2-h infusion on day 2, every 2 weeks. RESULTS: Tumor sites were gallbladder (19), extrahepatic bile ducts (5), ampulla of vater (3) and intrahepatic bile ducts (29). Results for group A (n = 3) were: objective response 36% [95% confidence interval (CI) 18.7% to 52.3%], stable disease 26%, progressive disease 39%, median progression-free survival (PFS) 5.7 months and overall survival (OS) 15.4 months. Results for group B (n = 23) were: objective response 22% (95% CI 6.5% to 37.4%), stable disease 30%, progressive disease 48%, PFS 3.9 months and OS 7.6 months. National Cancer Institute Common Toxicity Criteria grade 3-4 toxicities were neutropenia 14% of patients, thrombocytopenia 9%, nausea/vomiting 5% and peripheral neuropathy 7%. CONCLUSION: The GEMOX combination is active and well tolerated in ABTA.

Adenocarcinoma↗
PubMed2003

A phase II study of the vitamin D analogue Seocalcitol in patients with inoperable hepatocellular carcinoma.

Hepatocellular carcinoma (HCC) is a common malignant tumour, which has a poor prognosis. Surgical resection can be curative but most patients are inoperable and most chemotherapy agents have minimal activity in this disease. Seocalcitol, a vitamin D analogue, induces differentiation and inhibits growth in cancer cell lines and in vivo. The vitamin D receptor is expressed in hepatocytes and more abundantly in HCC cells. In total, 56 patients with inoperable advanced HCC were included in an uncontrolled study of oral Seocalcitol treatment for up to 1 year (with possible extension for responders). The dose was titrated according to serum calcium levels. The treatment effect was evaluated by regular CT scans. Out of 33 patients evaluable for tumour response, two had complete response (CR), 12 stable disease and 19 progressive disease. The CRs appeared after 6 and 24 months of treatment, and lasted for 29 and at least 36 months (patient still in remission when data censored). Seocalcitol was well tolerated; the most frequent toxicity was hypercalcaemia and related symptoms. Most patients tolerated a daily dose of 10 micro g of Seocalcitol. This is the first study showing activity, by reduction in tumour dimensions, of a differentiating agent in patients with an advanced bulky, solid tumour. Seocalcitol may have an effect in the treatment of HCC, especially in early disease when a prolonged treatment can be instituted. The survival benefit with or without tumour response should be determined in controlled studies.

Administration, Oral↗
PubMed2001

MDR3 gene defect in adults with symptomatic intrahepatic and gallbladder cholesterol cholelithiasis.

BACKGROUND & AIMS: Many studies indicate that gallstone susceptibility has genetic components. MDR3 is the phosphatidylcholine translocator across the hepatocyte canalicular membrane. Because phospholipids are a carrier and a solvent of cholesterol in hepatic bile, we hypothesized that a defect in the MDR3 gene could be the genetic basis for peculiar forms of cholesterol gallstone disease, in particular those associated with symptoms and cholestasis without evident common bile duct stone. METHODS: We studied 6 adult patients with a peculiar form of cholelithiasis. MDR3 gene sequence was determined by reverse-transcription polymerase chain reaction amplification of mononuclear cell RNAs followed by direct sequencing. Hepatic bile was analyzed in 2 patients. RESULTS: All patients shared the following features: at least 1 episode of biliary colic, pancreatitis, or cholangitis; biochemical evidence of chronic cholestasis; recurrence of symptoms after cholecystectomy; presence of echogenic material in the intrahepatic bile ducts; and prevention of recurrence by ursodeoxycholic acid therapy. Hepatic bile composition showed a high cholesterol/phospholipid ratio and cholesterol crystals. In all patients, we found MDR3 gene mutations involving a conserved amino acid region. CONCLUSIONS: These preliminary observations suggest that MDR3 gene mutations represent a genetic factor involved in this peculiar form of cholesterol gallstone disease in adults. They require further studies to assess the prevalence of MDR3 gene defects in symptomatic and silent cholesterol gallstone disease.

ATP Binding Cassette Transporter, Subfamily B↗
PubMed2001

Inhibition of hepatitis B virus replication by the interferon-inducible MxA protein.

Human MxA is an alpha/beta interferon-inducible intracytoplasmic protein that mediates antiviral activity against several RNA viruses. We had previously shown that overexpression of the hepatitis B virus (HBV) capsid led to selective downregulation of MxA gene expression, suggesting a mechanism by which the virus escapes from the host defense system (O. Rosmorduc, H. Sirma, P. Soussan, E. Gordien, P. Lebon, M. Horisberger, C. Brechot and D. Kremsdorf, J. Gen. Virol. 80:1253-1262, 1999). In the present study, we investigated the antiviral activity of MxA protein against HBV. MxA-expressing HuH7 clones were established and transiently transfected with HBV, and viral replication was then studied. Viral protein secretion was profoundly reduced in MxA-expressing clones by 80% for HBV surface antigen (HBsAg) and 70% for HBV e antigen (HBeAg). The levels of intracytoplasmic HBsAg and HBeAg were reduced by about 80 and 50% in the two MxA-positive clones tested. A nearly complete disappearance of HBV DNA replicative intermediates was observed in MxA-expressing clones. Although the expression of total viral RNAs was not modified, two- to fourfold reductions in HBV cytoplasmic RNAs were found in MxA-expressing clones. This suggests the inhibition of HBV replication at a posttranscriptional level. Indeed, using the well-characterized posttranscriptional regulation element (PRE) reporter system, we were able to demonstrate a marked reduction (three- to eightfold) in the nucleocytoplasmic export of unspliced RNA in MxA-expressing clones. In addition, MxA protein did not interact with HBV nucleocapsid or interfere with HBV nucleocapsid formation. Our results show an antiviral effect of MxA protein on a DNA virus for the first time. MxA protein acts, at least in part, by inhibiting the nucleocytoplasmic export of viral mRNA via the PRE sequence.

Antiviral Agents↗
PubMed2000

Differential HFE allele expression in hemochromatosis heterozygotes.

BACKGROUND & AIMS: Hereditary hemochromatosis is associated with C282Y homozygosity. Some heterozygotes may also present with abnormal iron parameters. However, the precise role of H63D and C282Y mutations in iron overload is poorly understood. We investigated the level of expression of the mutated and unmutated HFE alleles in these heterozygous patients. METHODS: We studied the expression of HFE messenger RNAs in peripheral blood mononuclear cells from 34 heterozygotes using reverse-transcription polymerase chain reaction (PCR) followed by enzymatic digestion or sequence analysis of the PCR products, which allows relative quantification of mutated and unmutated transcripts. HFE proteins were quantified by Western blotting in Epstein-Barr virus-immortalized lymphocyte extracts from 2 C282Y and H63D homozygotes and a compound heterozygote. RESULTS: (187C > G; H63D) mutated transcripts predominated in H63D and compound heterozygotes and the normal transcripts in C282Y heterozygotes. The amount of HFE protein was increased in the H63D homozygotes and the compound heterozygote compared with the C282Y homozygotes. In addition, we found a new mutation at codon 282 (C282S) associated with severe iron overload. CONCLUSIONS: We demonstrate the existence of differential allelic expression of the HFE alleles, suggesting that the (187C > G; H63D) mutation plays a role in the disease expression in H63D heterozygotes, in particular when associated with environmental or host factors.

Adult↗
PubMed1999

Bile acids modulate the interferon signalling pathway.

We have previously shown that cholestasis and bile acids inhibit 2', 5' oligoadenylate synthetase (OAS) activity in the liver and in primary hepatocyte cultures. Here, we assessed the influence of bile acids on interferon (IFN) pathway activation in three hepatoma cell lines. In HepG2 cells, bile acids (100-200 micromol/L) inhibited IFN-induced 2',5' OAS activity to an extent depending on their surface activity index. In Western blot analysis, IFN-induced expression of two major antiviral proteins, MxA and OAS p100, was reduced by 54% +/- 8% and 44% +/- 12%, respectively, when cells were preincubated for 4 hours with 100 micromol/L chenodeoxycholic acid (CDCA). In the same conditions, CDCA did not modify the IFN-induced signal transducers and activators of transcription (STAT)s tyrosine phosphorylation. In contrast, it reduced IFN-induced MxA promoter activity by 60%. The inhibitory effect of CDCA was not mediated by a 4beta-phorbol 12beta-myristate 13alpha-acetate (PMA)-sensitive protein kinase C (PKC)-dependent pathway. Finally, using CHO cells stably expressing a functional human bile acid carrier (Na+-dependent taurocholate cotransporting polypeptide [NTCP]), we found that bile acid inhibition of the IFN pathway occurred in the range of more physiological concentrations (12-50 micromol/L). In summary, our results provide strong evidence that bile acids inhibit the induction of proteins involved in the antiviral activity of IFN. This might partly explain the lack of responsiveness to IFN therapy in some patients with advanced chronic viral liver diseases.

2',5'-Oligoadenylate Synthetase↗
PubMed1999

Hepatocellular hypoxia-induced vascular endothelial growth factor expression and angiogenesis in experimental biliary cirrhosis.

We tested the potential role of vascular endothelial growth factor (VEGF) and of fibroblast growth factor-2 (FGF-2) in the angiogenesis associated with experimental liver fibrogenesis induced by common bile duct ligation in Sprague-Dawley rats. In normal rats, VEGF and FGF-2 immunoreactivities were restricted to less than 3% of hepatocytes. One week after bile duct ligation, hypoxia was demonstrated by the immunodetection of pimonidazole adducts unevenly distributed throughout the lobule. After 2 weeks, hypoxia and VEGF expression were detected in >95% of hepatocytes and coexisted with an increase in periportal vascular endothelial cell proliferation, as ascertained by Ki67 immunolabeling. Subsequently, at 3 weeks the density of von Willebrand-labeled vascular section in fibrotic areas significantly increased. Semiquantitative reverse transcription polymerase chain reaction showed that VEGF(120) and VEGF(164) transcripts, that correspond to secreted isoforms, increased within 2 weeks, while VEGF(188) transcripts remained unchanged. FGF-2 mainly consisting of a 22-kd isoform, according to Western blot, was identified by immunohistochemistry in 49% and 100% of hepatocytes at 3 and 7 weeks, respectively. Our data provide evidence that in biliary-type liver fibrogenesis, angiogenesis is stimulated primarily by VEGF in response to hepatocellular hypoxia while FGF-2 likely contributes to the maintenance of angiogenesis at later stages.

Animals↗
PubMed1999

Inhibition of interferon-inducible MxA protein expression by hepatitis B virus capsid protein.

Chronic hepatitis B treatment has been significantly improved by interferon (IFN) treatment. However, some studies have suggested that hepatitis B virus (HBV) might have a direct effect on the resistance to IFN. Defective particles, generated by spliced HBV RNA and associated with chronic hepatitis B, have been previously characterized; expression of these particles leads to cytoplasmic accumulation of the capsid protein. The aim of this study was to investigate the role of these defective genomes in IFN resistance. The global antiviral activity of IFN was studied by virus yield reduction assays, the expression of three IFN-induced antiviral proteins was analysed by Western blotting and confocal microscopy, and the regulation of MxA gene expression was studied by Northern blotting and the luciferase assay, in Huh7 cells transfected with a complete or the defective HBV genome. Results showed that the expression of the defective genome reduces the antiviral activity of IFN and that this modulation involves a selective inhibition of MxA protein induction by the HBV capsid protein. Our results also show the trans-suppressive effect of the HBV capsid on the MxA promoter, which might participate in this phenomenon. In conclusion, this study shows a direct interplay between the IFN-sensitive pathway and the capsid protein and might implicate this defective HBV genome in virus persistence.

Blotting, Northern↗
PubMed1998

Cytosol is the prime compartment of hepatitis B virus X protein where it colocalizes with the proteasome.

The hepatitis B virus X protein plays an important role in the regulation of viral genome expression and has also been implicated in the development of liver cancer associated with chronic viral infection. Several effects have been attributed to X but their biological relevance remains elusive. One of the confusing issues has been so far the uncertainty concerning its cellular location. To gain insight into the mechanism(s) how X exerts its effects, we have analysed its subcellular distribution and its dependency on the cell cycle. We used two complementary approaches namely, immunolocalization using a cell line stably expressing X, and characterization of the dynamics of X location in living cells by means of the reporter gene GFP. Our data clearly define the cytosol as the prime location of X, irrespectively of the cell cycle and show in addition the close attachment of a fraction of X to the nuclear membrane. However, X does not associate with any cytoplasmic vesicles and organelles so far tested. In contrast, our study provides strong evidence for the codistribution of X with the cytosolic fraction of proteasomes. In pulse-chase experiments, X decayed with a half-life of less than 30 min and proteasome-inhibitors did not modify its turnover, suggesting that X colocalization with the proteasome does not simply point to its degradation pathway. The proteolytic processing of the p105 precursor of the p50 subunit of the NF-kappaB transcription factor, which has been shown to be proteasome-dependent, is markedly slow down in the presence of X. These findings suggest that X modulates the processing rate of p105 by acting presumably at the level of the proteasome. Thus, targeting of proteasomes by X might be one of the pathways employed by this viral protein to subvert cellular functions.

Animals↗
PubMed1998

Determinants of outcome of compensated hepatitis C virus-related cirrhosis.

The aim of this study was to assess the incidence of decompensation (ascites, jaundice, variceal bleeding, and encephalopathy), hepatocellular carcinoma (HCC) and death or liver transplantation in patients with compensated hepatitis C virus (HCV)-related cirrhosis, taking into account the viral genotype and interferon (IFN) therapy. Between 1989 and 1994, 668 patients with no clinical evidence of decompensation were referred to our department for liver biopsy because of positivity for anti-HCV antibodies and elevated aminotransferase activity; 103 of these patients had cirrhosis. The median follow-up was 40 months. Fifty-nine patients were treated with IFN for a mean duration of 11+/-6 months; 3 (5%) had a prolonged biochemical and virological response. Baseline characteristics of IFN-treated and untreated patients were not significantly different. HCV genotypes (InnoLiPa) were predominantly 1b (48%) and 3a (20%). During follow-up, complications of cirrhosis occurred in 26 patients, HCC in 11 patients, and decompensation not related to HCC in 19 patients. Sixteen patients died, 94% of liver disease. Three patients were transplanted for liver failure. The 4-year risk of HCC was 11.5% (annual incidence 3.3%) and that of decompensation was 20%. Survival probability was 96% and 84% at 2 and 4 years, respectively. In multivariate analysis, the absence of IFN therapy was the only independent factor predictive both for HCC and decompensation. A low albumin level at entry and the absence of IFN therapy were the two independent factors predictive of death or liver transplantation. Probability of survival at 2 and 4 years was significantly different between IFN-treated and untreated patients (respectively 97% and 92% vs 95% and 63%, P < .0001). In conclusion, in patients with compensated HCV-related cirrhosis: 1) complications of cirrhosis are frequent, whatever the viral genotype; and 2) the severity of cirrhosis and the absence of IFN therapy are independently predictive of bad outcome.

Adult↗
PubMed1998

Primary biliary cirrhosis-autoimmune hepatitis overlap syndrome: clinical features and response to therapy.

The association of primary biliary cirrhosis (PBC) and autoimmune hepatitis (AIH) is thought to be rare, and its optimal treatment is unknown. Of 130 consecutive patients with a diagnosis of PBC, we identified 12 cases (9.2%) of overlap syndrome (10 females, 2 males; median age, 50 years) strictly defined by the presence of at least two of the three recognized biochemical, serological, and histological criteria of each disease. One patient had initially pure PBC and developed AIH characterized by a flare of alanine transaminase (ALT) (1,330 IU/L; N < 35), elevated immunoglobulin G (IgG) (42 g/L; N < 14.0), and presence of anti-smooth muscle antibodies (ASMA) after 20 months of ursodeoxycholic acid (UDCA) therapy. A complete clinical and biochemical remission was achieved under combination of corticosteroids and UDCA. Eleven patients had features of both diseases at presentation: high serum levels of alkaline phosphatase (AP) (median: 280 IU/L; N < 100), ALT (140 IU/L), and IgG (30.8 g/L), presence of mitochondrial antibodies (n = 9) or ASMA (n = 9), florid bile duct lesions (n = 8), and moderate or severe periportal or periseptal lymphocytic piecemeal necrosis (n = 11). UDCA (13-15 mg/kg/d) given alone in 5 patients induced a significant decrease in biochemical cholestasis but not in ALT levels, and liver fibrosis progressed in 3 patients. Corticosteroids given alone in 6 patients induced a significant decrease in ALT, IgG, and AP levels, but none had a biochemical normalization. The patients with persistently abnormal liver tests under either UDCA or corticosteroids received both UDCA and corticosteroids. A further marked biochemical improvement was observed, and all patients became asymptomatic. We conclude that, in patients with PBC: 1) overlap syndrome with AIH is not rare; 2) flares of AIH may occur either spontaneously or under UDCA; and 3) combination of UDCA and corticosteroids is required in most patients to obtain a complete biochemical response. Overlap syndrome may represent an important and unrecognized cause of resistance to UDCA in patients with PBC.

Adrenal Cortex Hormones↗
PubMed1995

In vivo and in vitro expression of defective hepatitis B virus particles generated by spliced hepatitis B virus RNA.

The mechanisms involved in hepatitis B virus (HBV) persistence are still poorly understood. We have previously shown that the encapsidation of the singly spliced 2.2 kb-HBV RNA leads to the secretion of circulating HBV defective particles in patients with chronic hepatitis. We have now investigated the presence of the HBV defective particles in sera from patients with acute and chronic hepatitis, using polymerase chain reaction. These defective particles were detected in a larger amount in sera of patients with acute hepatitis that progressed to chronic hepatitis, or had already developed chronic hepatitis, as compared with those who recovered from acute hepatitis (the increase was estimated to be an average of 50-fold). In addition, we showed that the presence of these defective HBV particles is closely associated with the chronic course of hepatitis B virus infection and with viral multiplication. We also analyzed viral RNAs and proteins synthetized after in vitro transfection of Huh7 cell line with the corresponding defective hepatitis B virus DNA molecule. We showed that expression of the defective hepatitis B virus DNA alone leads to a marked intracellular accumulation of the major core protein (HBcAg) and to an increased secretion of hepatitis B e antigen (HBeAg). These observations may be consistent with a role of these defective hepatitis B virus (HBV) particles in viral persistence.

Base Sequence↗
PubMed1992

[Severe hepatic steatosis: a cause of sudden death in the alcoholic patient].

The authors report the cases of 4 patients with heavy chronic alcoholic intake who presented with hepatomegaly and jaundice without obvious hepatic failure and who died rapidly. In all 4 cases, histological examination of the liver showed massive microvesicular and macrovesicular steatosis involving approximately 100% of hepatocytes and, in 2 cases, minimal lesions of alcoholic hepatitis. Histochemical study, performed in 3 cases, showed that steatosis was constituted of triglycerides only, and that hepatic glycogen was completely depleted in 2 of 3 cases. No obvious cause of death was found in these 4 patients. Shortly, before their death, the 4 patients had increased their ethanol and decreased their food intake. The authors suggest that death as well as microvesicular steatosis could have be due to acute mitochondrial dysfunction.

Death, Sudden↗