Search PubMed⌕ Search

Biomedical subjects

C Dufour

Publications and source records attributed to C Dufour.

At least 55 records · Page 3Linked to original sources
PubMed1994

Identification of a mutation near a functional site of the beta cardiac myosin heavy chain gene in a family with hypertrophic cardiomyopathy.

Several mutations within the gene coding for the cardiac beta myosin heavy chain (designed MYH7) have been shown to be responsible for Familial Hypertrophic Cardiomyopathy (FHC) in several families, and evidence of genetic heterogeneity has been reported. To investigate the MYH7 gene as the cause of the disease in a small family with FHC, inheritance of the disease and chromosome 14 q11-q12 markers haplotype were studied, exons coding for the head domain of the cardiac beta myosin heavy chain (beta MHC) were analysed for mutations by MDE gel electrophoresis, and sequenced. We report a mutation within exon eight of the MYH7 gene at a very conserved amino acid at position 232, which results in the conversion of an asparagine to serine. This residue Asn-232 is located in a MHC area that has been recently identified as a critical site for ATPase activity. According to recent results on the three-dimensional structure of the myosin head or subfragment-1 (S1), Asn-232 is located in an alpha-helix which forms part of the nucleotide binding pocket. Although this mutation affects an active site, it seems to be associated with a favourable prognosis and a weak penetrance in this family.

Adult↗
PubMed1993

Mapping of a novel gene for familial hypertrophic cardiomyopathy to chromosome 11.

Familial hypertrophic cardiomyopathy (FHC) is a cardiac disorder transmitted as an autosomal dominant trait. FHC has been shown to be genetically heterogeneous with less than 50% of published pedigrees being associated with mutations in the beta myosin heavy chain (beta-MHC) gene on chromosome 14q11-q12. A second locus has recently been reported on chromosome 1. We examined the segregation of microsatellite markers in a French pedigree for which the disease is not linked to beta-MHC gene. We found significant linkage of the disease locus to several (CA)n repeats located on chromosome 11 (lod scores between +3.3 and +4.98). The data suggest the localization of the novel FHC gene in a region spanning 17 centiMorgans.

Cardiomyopathy, Hypertrophic↗
PubMed1993

Familial hypertrophic cardiomyopathy. Microsatellite haplotyping and identification of a hot spot for mutations in the beta-myosin heavy chain gene.

Familial hypertrophic cardiomyopathy (FHC) is a clinically and genetically heterogeneous disease. The first identified disease gene, located on chromosome 14q11-q12, encodes the beta-myosin heavy chain. We have performed linkage analysis of two French FHC pedigrees, 720 and 730, with two microsatellite markers located in the beta-myosin heavy chain gene (MYO I and MYO II) and with four highly informative markers, recently mapped to chromosome 14q11-q12. Significant linkage was found with MYO I and MYO II in pedigree 720, but results were not conclusive for pedigree 730. Haplotype analysis of the six markers allowed identification of affected individuals and of some unaffected subjects carrying the disease gene. Two novel missense mutations were identified in exon 13 by direct sequencing, 403Arg-->Leu and 403Arg-->Trp in families 720 and 730, respectively. The 403Arg-->Leu mutation was associated with incomplete penetrance, a high incidence of sudden deaths and severe cardiac events, whereas the consequences of the 403Arg-->Trp mutation appeared less severe. Haplotyping of polymorphic markers in close linkage to the beta-myosin heavy chain gene can, thus, provide rapid analysis of non informative pedigrees and rapid detection of carrier status. Our results also indicate that codon 403 of the beta-myosin heavy chain gene is a hot spot for mutations causing FHC.

Adolescent↗
PubMed1993

Exclusion of genes coding for proteins of the cytoskeleton and the extracellular matrix in familial hypertrophic cardiomyopathy using a candidate gene approach.

Familial hypertrophic cardiomyopathy (FHC), a primary cardiac pathology, is a genetically heterogeneous disease, with autosomal dominant inheritance. The first gene identified as responsible for FHC codes for beta-myosin heavy chain (beta-MHC). To find a second locus, a candidate gene approach was applied on two families for which the beta-MHC locus was excluded. Selection of candidate genes is based on the observation of tissular and cellular disorganisation in FHC, and included genes coding for proteins involved in human myocardium architecture: the extracellular matrix components and cytoskeleton proteins. Chromosomal areas containing the candidate genes were examined by linkage analysis with microsatellite markers. The genes coding for different types of collagens, laminins, fibronectin, fibrillins, desmin, titin, alpha-actinin, vinculin, cardiac and skeletal alpha-actins, ankyrin and spectrin were excluded as responsible for FHC.

Cardiomyopathy, Hypertrophic↗
PubMed1992

Radioimmunodetection of human bladder tumor xenografts in nude mice with radiolabeled monoclonal antibodies.

The tumor targeting potential of two monoclonal antibodies (mAbs) reacting with growth-regulated surface glycoproteins of human bladder cancer was investigated. The mAb T16 reacts more intensely with stationary cells while the mAb T43 is preferentially reactive with exponentially growing cells. The test target was T24 human bladder cancer cells grown subcutaneously in 30 nude mice. Controls for tumor specificity were human lung cancer cells grown on the contralateral side. Purified mAb's T16 and T43, and Om5, a non-reactive control, were radiolabeled with 131-Iodine and injected intravenously in doses ranging from 50 to 300 microCi in tumor-bearing animals. Consistent images of the bladder cancer xenografts were obtained at 48 and 72 hours with tumors as small as 0.1 gm. High resolution tumor images were obtained only with the reactive antibodies and according to their in vitro specificity. These results demonstrate that the two mAbs T16 and T43 can specifically and sensitively localize human bladder cancer cells in vivo.

Animals↗
PubMed1992

Hypertrophic gastropathy with transient sessile polyps.

We report an 8-year-old boy with hypertrophic gastropathy (HG) associated with duodenal Giardia lamblia infestation. The follow-up was complicated by the development of gastric polyps at the site of previous biopsies that spontaneously disappeared within 15 months. Despite the histological similarity, the different course between Ménétrier's disease (MD) in adults (chronic, with frequent development of sessile or pedunculate polyps) and HG (uncomplicated and usually spontaneously resolving) suggests a different pathogenesis. Viral (cytomegalovirus) and bacterial (Helicobacter pylori) infections have been described in association with HG and they could play an important pathogenetic role. The term HG better defines the childhood disease in which a conservative management is recommended.

Animals↗
PubMed1992

Exclusion of cardiac myosin heavy chain and actin gene involvement in hypertrophic cardiomyopathy of several French families.

Familial hypertrophic cardiomyopathy (FHC) is characterized by idiopathic myocardial hypertrophy, which often and predominantly involves the interventricular septum. The disease is transmitted as an autosomal dominant trait, and its major risk is sudden death. It was recently demonstrated that this disease is genetically heterogeneous and that in 13 of 18 unrelated families the morbid locus, termed FHC-1, maps to chromosome 14q11-12 in and/or very near the cardiac beta-myosin heavy chain gene. We have performed linkage analysis with five chromosomal markers detecting polymorphisms in either the cardiac beta-myosin heavy chain gene or the cardiac actin gene (located on chromosome 15q) on eight families from different regions of France. We show that 1) it is possible to analyze medium-sized families by using highly informative microsatellite markers located in these genes and 2) the disease is not linked to the two contractile protein genes in any of these families. Moreover, 10-20% of chromosome 14 and 20-40% of chromosome 15 in the vicinity of the respective markers were excluded as possible locations for the morbid locus. These results provide new insights into the identification of the genes responsible for FHC.

Actins↗
PubMed1990

Monoclonal antibody against a tumor-associated sialoglycoprotein of superficial papillary bladder tumors and cervical condylomas.

A mouse IgG1 monoclonal antibody (MAb), 19A211, defining a tumor-associated cell-surface antigen of superficial papillary bladder tumors, was generated by immunizing with fresh bladder tumor cells mice neonatally injected with normal human urothelial cells. The reactivity of the antibody with cell lines was examined by indirect immunofluorescence staining and was restricted to 3/14 bladder cancer lines and 3/31 cancer cell lines of non-bladder origin, including HeLa cervical cancer. No normal fibroblast, kidney cells, EBV-lymphocytes, erythrocytes or leukocytes expressed the antigen. Reactivity of MAb 19A211 was well preserved on tissue paraffin sections. Immunoperoxidase staining of normal adult or fetal tissues showed no reactivity except for a patchy or uniform staining of umbrella cells in 6/23 adult and 1/4 fetal urothelium samples. Positive and often heterogeneous staining was observed on 24/38 papillary superficial tumors (Ta) and 4/5 carcinoma in situ bladder lesions but on only 4/20 infiltrating tumors. It was also observed on 5/6 cervical condylomas and one bladder condyloma, but none of 6 penile or vulvar condylomas. All other tumors tested were negative. The antigenic determinant is present on a heterogeneous group of proteins with molecular weights ranging from 90 to 200 kDa. It is sensitive to periodate treatment and to neuraminidase but only partially sensitive to proteases. MAb 19A211 is different from other reported MAbs with similar reactivity to superficial bladder tumors and umbrella cells of normal urothelium. When tested in competition assays, several of these MAbs, but not 19A211, were found to react with Lewis X blood group determinant. Our results suggest that 19A211 may be useful for detection and stratification of bladder tumors.

Antibodies, Monoclonal↗
PubMed1988

Spermine and spermidine induce intestinal maturation in the rat.

In the present study, we aimed to induce precocious intestinal maturation in neonatal rats by the oral administration of polyamines. Groups of 5 rats received either saline, spermidine (10 mumol daily), or spermine (6 mumol daily) orally on the 12th, 13th, and 14th postnatal days. The rats were killed on the 15th postnatal day. After the small bowel was removed, a 1-cm distal ileal segment was removed for histologic examination and the remaining small bowel tissue was homogenized for further biochemical analysis. Polyamine administration was shown to induce structural and biochemical mucosal changes characteristic of postnatal maturation. Lactase, sucrase, and maltase specific activities (micromoles of substrate hydrolyzed per minute per gram of protein) were 80 +/- 10, 10 +/- 3, and 116 +/- 19 for the saline-treated rats; 51 +/- 7, 34 +/- 2, and 315 +/- 37 for the spermidine-treated rats; and 25 +/- 2, 46 +/- 5, and 419 +/- 63 for the spermine-treated rats, respectively. Similar results were obtained with rats, first treated with spermine (6 mumol) on the 7th postnatal day, receiving spermine (6 mumol) daily as described above and killed on the 10th postnatal day. Dose-response experiments performed as reported above in rats whose treatment began on the 12th postnatal day showed that the maturational effects of orally administered spermine are dose-dependent.

Age Factors↗