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Biomedical subjects

M Hadchouel

Publications and source records attributed to M Hadchouel.

At least 55 records · Page 3Linked to original sources

Correction of fumarylacetoacetate hydrolase deficiency (type I tyrosinemia) in cultured human fibroblasts by retroviral-mediated gene transfer.

Type I hereditary tyrosinemia results from an inherited deficiency in fumarylacetoacetate hydrolase, the enzyme involved in the last step in tyrosine catabolic pathway. The cloning of the cDNA encoding FAH in human has opened the way to genetic treatment of HT 1. We have constructed recombinant retroviral vectors carrying the cDNA encoding human FAH. In the present report we show that these vectors are able to restore FAH activity stably in primary fibroblasts from HT 1 patients and at high level. The possibility to express FAH stably in deficient patients represents a first step towards future gene therapy for type I hereditary tyrosinemia and may help to decipher the pathogenesis of the disease at the molecular level.

Amino Acid Metabolism, Inborn Errors↗

Genetic heterogeneity of Crigler-Najjar syndrome type I: a study of 14 cases.

Crigler-Najjar syndrome type I (CN-I) is an autosomal recessive condition characterized by severe unconjugated hyperbilirubinemia caused by the lack of bilirubin-UDP-glucuronosyltransferase (B-UGT) activity in the liver. Two B-UGTs are coded for by a gene complex (UGT1) that maps to chromosome 2q37 and that also encodes two phenol-UDP-glucuronosyltransferases. Here, we report eleven mutations (including nine novel mutations) of the B-UGT1 gene in a large series of 14 unrelated CN-I children of various geographic origins: France (seven patients: A401P, Q357X, W335X, A368T, 1223insG, A291V, K426E, K437X); Portugal (two patients: G308E); Tunisia (two patients; Q357R); Turkey (one patient: S381R); italy (two siblings: S381R). Interestingly, 6/14 mutant alleles carried by unrelated probands of French ancestry bore the A401P mutation, indicating a founder effect; this effect is probably also present in Portugal, Turkey, and Tunisia. Since mutations occurred in exons 2-5 shared by all mRNAs species of the gene, a combined deficiency of B-UGT and P-UGT was observed in the liver of five patients in whom these activities were measured. The present study confirms that CN-I is genetically heterogeneous and suggests that different founder effects are involved in Western Europe, the Middle East, and North Africa.

Crigler-Najjar Syndrome↗

Deleted chromosome 20 from a patient with Alagille syndrome isolated in a cell hybrid through leucine transport selection: study of three candidate genes.

Alagille syndrome (AGS) is a well-defined genetic entity assigned to the short arm of Chromosome (Chr) 20 by a series of observations of AGS patients associated with microdeletions in this region. By fusing lymphoblastoid cells of an AGS patient that exhibited a microdeletion in the short arm of Chr 20 encompassing bands p11.23 to p12.3 with rodent thermosensitive mutant cells (CHOtsH1-1) deficient in-leucyl-tRNA synthetase, we isolated a somatic cell hybrid segregating the deleted human Chr 20. This hybrid clone, designated NR2, was characterized by several methods, including PCR, with eight pairs of oligonucleotides mapped to Chr 20: D20S5, D20S41, D20S42, D20S56, D20S57, D20S58, adenosine deaminase (ADA), and Prion protein (PRIP); Restriction Fragment Length Polymorphism (RFLP) analyses with four genomic anonymous probes (D20S5, cD3H12, D20S17, D20S18); and fluorescent in situ hybridization (FISH) with total human DNA and D20Z1, a sequence specific to the human Chr 20 centromere, as probes. The NR2 hybrid allowed us to exclude three candidate genes for AGS: hepatic nuclear factor 3 beta (HNF3 beta), paired box 1 (PAX1), and cystatin C (CST3) as shown by their localization outside of the deletion. The NR2 hybrid is a powerful tool for the mapping of new probes of this region, as well as for obtaining new informative probes specific for the deletion by subtractive cloning of the region. Such markers will be useful for linkage analysis and screening of cDNA libraries.

Alagille Syndrome↗

Evidence for defective primary bile acid secretion in children with progressive familial intrahepatic cholestasis (Byler disease).

To clarify the relationship of progressive familial intrahepatic cholestasis (Byler disease) to bile acid metabolism, we analysed, by high performance liquid chromatography, the bile acid composition of serum and bile in seven children with Byler disease and in eight control children with other cholestatic diseases. In serum, total bile acid concentration was increased in patients with Byler disease (0.30 +/- 0.05 mmol/l) and in control patients (0.21 +/- 0.08 mmol/l). Cholate (C) and chenodeoxycholate (CDC) comprised the major proportion of total bile acids in patients with Byler disease as in control patients. Hyocholate (HC) was only detected in patients with Byler disease and lithocholate was only present in control children. In bile, total bile acid concentration was very low in patients with Byler disease (1.1 +/- 1.4 mmol/l) compared to control patients (88.9 +/- 83.2 mmol/l). C and CDC were the major bile acids in control patients, whereas C and HC comprised the major proportion of bile acids in patients with Byler disease. These results suggest the existence of a defect of primary bile acid secretion in Byler disease characterized by the presence of high concentration of bile acids in serum and absence or very low concentration of bile acids in bile.

Bile↗

Portal cavernoma in congenital hepatic fibrosis. Angiographic reports of 10 pediatric cases.

A retrospective pediatric study of 30 angiograms in congenital hepatic fibrosis (CHF) was undertaken to analyze the different aspects of the portal venous system in this disease. Besides the classical angiographic signs (hepatofugal veins and intrahepatic duplications), a hepatopetal venous network was present in ten children, contrasting with the patency of the portal venous system. Analysis of the medical charts for these ten patients showed that the clinical signs and outcome were similar to classical CHF. Liver biopsies were available in six cases and, in addition to the diagnostic features of CHF, demonstrated paucity or absence of portal venules. This unusual association of hepatopetal and hepatofugal collateral veins in an intrahepatic block could be explained by hypoplasia or thrombosis of portal venules. Thus, the association between hepatomegaly and hepatopetal collateral veins without portal obstruction should be suggestive of CHF.

Angiography, Digital Subtraction↗

A new cause of progressive intrahepatic cholestasis: 3 beta-hydroxy-C27-steroid dehydrogenase/isomerase deficiency.

There have been a few reports of infants with severe neonatal cholestasis related to a defect in primary bile acid synthesis. To assess the importance of such deficiency among children with progressive intrahepatic cholestasis (Byler disease), screening for inborn errors in bile acid synthesis was performed by fast atom bombardment ionization-mass spectrometry of urine samples from 30 affected children. Bile acid analysis revealed a specific fast atom bombardment ionization-mass spectrometry profile for 3 beta-hydroxy-C27 steroid dehydrogenase/isomerase deficiency in five children who had jaundice, hepatosplenomegaly, and fatty stools beginning at ages ranging from 4 to 46 months. None of them had pruritus. Liver function tests showed persistently normal serum gamma-glutamyltransferase activity, low serum cholesterol and vitamin E levels, normal serum bile acid concentrations despite raised serum bilirubin levels, and decreased prothrombin time and clotting factor V. In four of the cases a similar disease was observed in siblings. Liver function returned to normal after oral ursodeoxycholic acid therapy. We conclude that 3 beta-hydroxy-C27-steroid dehydrogenase/isomerase deficiency should be considered when idiopathic cholestatic liver disease with clinical features akin to Byler disease is characterized by the association of normal serum gamma-glutamyltransferase activity, normal serum bile acid concentration, absence of pruritus, and a return to normal liver function during ursodeoxycholic acid therapy. Early identification of these children is essential because they benefit from bile acid therapy and might thus avoid the need for liver transplantation.

Alanine Transaminase↗

Sclerosing cholangitis in children.

We report on 56 children with sclerosing cholangitis (SC) seen between 1972 and 1992. The first symptoms occurred at a mean age of 3.7 years; 15 infants had neonatal cholestatic jaundice. At diagnosis, cholestatic jaundice was present in 25 children, hepatomegaly in 54, splenomegaly in 41, and ascites in 12. Serum alkaline phosphatase activity was increased in 49 patients and gamma-glutamyltransferase activity in all patients tested. Most often the histopathologic findings were extensive portal fibrosis and neoductular proliferation. Cholangiography showed abnormal intrahepatic bile ducts in all children and abnormal extrahepatic bile ducts in 35 (63%). The children were separated into three groups: (1) those with SC of neonatal onset (27%); (2) those with SC of postneonatal onset associated with another disease (55%)--histiocytosis X in 14 children, immunodeficiency syndromes in 8, chronic inflammatory bowel disease or autoimmune hepatitis in 8, and congenital psoriasis in 1; and (3) those with SC of postneonatal onset without an associated disease (18%). Biliary cirrhosis was present in all but three children after 6 months to 19.3 years of follow-up. Eleven children died of portal hypertension or liver failure, and six died of a complication related to the associated disease. Fifteen children had liver transplantation; 11 of these are alive 6 months to 6 1/2 years later without recurrence of SC. The overall estimated median survival time of children with SC was 10 years from clinical onset. These results indicate that SC should be suspected in all children with a chronic cholestatic disease and increased serum gamma-glutamyl transferase activity, especially when diseases known to be associated with SC are present. The prognosis is poor, but liver transplantation should be considered except in those with severe immunodeficiency syndromes.

Adolescent↗

Segregation analysis of Alagille syndrome.

Alagille syndrome (AGS) is a well defined genetic disorder characterised by five major features. An autosomal dominant mode of transmission with reduced penetrance has been suggested by the analysis of a limited number of families. However there has been no statistical analysis. We report here the first segregation analysis of AGS, using 33 families collected through 43 probands. Segregation analysis of these families allowed us to conclude that AGS is transmitted as a dominant disorder with 94% penetrance and 15% of cases are sporadic. The expressivity of the phenotype was variable and 26 persons (15 parents and 11 sibs) were identified as presenting minor forms of the disease. These results are valuable for genetic counselling.

Alagille Syndrome↗

Mapping of microsatellite markers in the Alagille region and screening of microdeletions by genotyping 23 patients.

Alagille syndrome (AGS) has been assigned to 20p11.23-20p12.2 according to minimum overlap between deletions observed on the chromosome 20 short arm of 9 patients. We report here the localisation of 5 microsatellite markers (D20S41, D20S48, D20S50, D20S56, and D20S58) within the deletion of one AGS patient. This study allows an estimation of the genetic extent of this deletion as being between 30 and 36 cM, and demonstrates its paternal origin. The search for submicroscopic deletions in 23 AGS patients, by typing these 5 markers, failed to reveal allelic loss. However, these results lead to the proposition that the AGS locus lies in one of the seven intervals defined by the six microsatellite markers in the region flanked by D20S5 and D20S18.

Alagille Syndrome↗

Induction of anti-hepatitis B surface antigen (HBsAg) antibodies in HBsAg producing transgenic mice: a possible way of circumventing "nonresponse" to HBsAg.

As a model for studying possible mechanisms of nonresponse toward hepatitis B surface antigen (HBsAg) in hepatitis B virus (HBV) carriers, we used transgenic (Tg) mice which constitutively express this antigen in the liver from before birth. The mice secrete large amounts of HBsAg particles into the sera without producing antibodies. Tg and control mice were immunized with either recombinant HBsAg particles of a different subtype, or with recombinant hybrid HBsAg particles carrying a human immunodeficiency virus (HIV) envelope determinant. The presence of determinants to which the mice are tolerant on the injected particles does not hamper the response to the foreign epitope. Moreover, a weak but significant anti-HBs response is clearly detectable in Tg mice immunized with these particles. Antibodies to epitopes carried by the transgenic antigen are made even after injection of homologous antigen, and a concomitant decrease in circulating HBsAg is observed. This immune response does not induce any liver damage. It was demonstrated that in these Tg mice, B cell self-tolerance toward HBsAg can be overcome by immunization. This phenomenon raises the possibility of designing more effective methods of immunotherapy for HBV carriers.

Animals↗

Genetic restriction of murine hepatitis virus type 3 expression in liver and brain: comparative study in BALB/c and C3H mice by immunochemistry and hybridization in situ.

To study the host-dependent genetic variations in murine hepatitis virus type 3 (MHV 3) induced diseases, we localized the sites of MHV 3 (Mill Hill strain) expression within liver and brain by immunohistochemistry or hybridization in situ. Two strains of mice were studied: BALB/c mice, which develop an acute and lethal hepatitis and C3H mice which develop a chronic brain infection. In BALB/c mice, viral RNA and antigens appeared during the first 24h post infection (p.i.) in liver, whereas viral RNA was barely detectable in brain, up until death at day 3 p.i. In C3H mice, viral RNA and antigens were detected simultaneously in liver and brain only at day 2 p.i. In brain, the virus was detected in meningeal and ependymal cells and in perivascular cortical areas (days 5 and 7 p.i.). After day 49, the virus was no longer detected in brain parenchyma, but persisted in meningeal cells. Two host-dependent genetic differences in viral processing were observed in the liver: (1) the virus was first detected in Kupffer cells in BALB/c mice and mostly in hepatocytes in C3H mice; (2) in BALB/c mice, the 180 kDa S viral glycoprotein appeared more frequently cleaved in 90 kDa form than in C3H mice.

Animals↗

The gene encoding the nucleocapsid protein: sequence analysis in murine hepatitis virus type 3 and evolution in Coronaviridae.

The nucleoprotein-encoding gene (N) of murine hepatitis virus type 3 (MHV 3), from the Mill Hill strain, was cloned and sequenced. It was compared to gene N from other murine coronaviruses and was found to share more similarities with N sequences from MHV 1 and MHV JHM strains than with the published MHV 3 N sequence which is almost identical to MHV A59. We suggest that the evolution of some MHV N sequences resulted from a double recombination phenomenon between two ancestors. Furthermore, comparison of protein N from avian and mammalian coronaviruses leads to the hypothesis that horizontal transfer events of the virus from one host species to another have occurred.

Amino Acid Sequence↗

Autoimmune hepatitis associated with anti-actin antibodies in children and adolescents.

The clinical, biochemical, morphological, and evolutive features of autoimmune hepatitis associated with serum smooth muscle antibodies of anti-actin specificity were retrospectively analyzed in 31 children and adolescents. Cirrhosis was present at diagnosis in all but six patients, including nine of the 12 diagnosed within 6 months from the onset. In 15 children, one or more associated diseases of an immune-mediated mechanism were present, including chronic arthritis, sclerosing cholangitis, inflammatory bowel disease, and cutaneous vasculitis. All patients were treated with prednisone and azathioprine with normalization or improvement of liver function tests: 28 children are currently alive after a mean follow-up of 4 years, 10 months. Treatment was interrupted in four patients only. Two patients died of liver failure in spite of immunosuppressive therapy before the era of liver transplantation. In spite of prolonged therapy, five other patients ultimately required liver transplantation during adolescence or early adulthood. These results (a) further define a group of autoimmune hepatitis in children characterized by the presence of serum anti-actin antibodies; (b) indicate that immunosuppressive therapy improves liver function, although in most cases it must be continued for a long period to maintain remission; and (c) suggest that progressive liver failure may occur in early adulthood and may require liver transplantation.

Actins↗

Intrahepatic bile duct damage in children with Kawasaki disease.

Three children with Kawasaki disease had liver biopsies because of evidence of hepatic disease. Cholangitis or bile duct injury and proliferation were found. Similar damage to the hepatic ductular system may explain the hydrops of the gallbladder sometimes seen in this disease.

Bile Ducts, Intrahepatic↗

Enhanced tumor necrosis factor alpha in coronavirus but not in paracetamol-induced acute hepatic necrosis in mice.

Previous reports have demonstrated that tumor necrosis factor alpha (TNF-alpha) plays an important role in the pathogenesis of fulminant hepatic necrosis. The purpose of this experimental study was to measure TNF-alpha blood activity in paracetamol-induced liver necrosis and in coronavirus (MHV3)-induced fulminant hepatitis in mice. No elevation of TNF-alpha activity was found in hepatic failure complicating paracetamol poisoning. In contrast, TNF-alpha activity significantly increased in response to MHV3, reaching 16.3 +/- 5.5 U/ml from 24 h post infection (P less than 0.01). This augmentation was observed even though the virus was not detectable in the liver. Serum alanine aminotransferase levels were low and no histological lesion was observed. In conclusion, our study further supports the implication of TNF-alpha in virus-induced hepatitis failure and confirms that paracetamol poisoning does not cause increased TNF-alpha activity in the circulation.

Acetaminophen↗