A novel mutation (Arg-->Leu in exon 18) in factor VIII gene responsible for moderate hemophilia A.
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Arginine↗
Biomedical subjects
M Delpech
Publications and source records attributed to M Delpech.
Study of a restriction fragment length polymorphism for serum amyloid P gene in rheumatoid arthritis with amyloidosis.
Amyloidosis is a severe complication of rheumatoid arthritis (RA). A restriction fragment length polymorphism (RFLP) using MspI for the serum amyloid P gene was recently found to be associated with amyloidosis in juvenile arthritis. The aim of our study was to determine whether this RFLP could serve as a genetic marker for the development of secondary amyloidosis in RA. The prevalence of this marker was determined in 4 groups of patients: patients with amyloidosis secondary to RA; with amyloidosis secondary to various diseases excluding RA; with RA but without amyloidosis; adult controls without any known disease related to reactive amyloidosis. No significant differences were seen between these 4 groups with relation to this polymorphism, so that it cannot serve as a genetic marker for amyloidosis complicating RA in our population.
Amyloidosis↗
Investigation of factor VIII:C gene restriction fragment length polymorphisms and search for deletions in hemophiliac subjects in Algeria.
The frequency of alleles for intragenic (intron 17 and intron 25) and extragenic (DXS15 and DXS52) F8C RFLPs was investigated in the Algerian population. Altogether 287 X chromosomes (97 males and 95 females) were studied. The allele frequencies found with the two intragenic F8C RFLPs were not substantially different from those reported in a Mediterranean population. At the highly polymorphic extragenic DXS52 locus the distribution in Algeria differed from that found in France. A new allele (14 kb), called 1 DZ, was found in 3.1% of the chromosomes. Fifty-one families with hemophilia A were studied with the same probes (374 subjects). Of the females, 94% were informative for at least one intra- or extragenic RFLP. Two recombinations were found between DXS52 and F8C, of which one occurred between the DXS15, DXS52 block and F8C, indicating that the two anonymous loci are on the same side of the F8C gene. Only two obvious gene deletions were observed in 73 unrelated hemophiliacs: one encompassed exons 14-22 (about 4.3 kb of cDNA and 36 kb of genomic DNA); the other removed the last exon (exon 26, representing 2 kb of cDNA).
Algeria↗
A new TaqI allele at DXS52 frequent in Algeria.
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Algeria↗
Purification and comparison of liver microsomal flavin-containing monooxygenase from normal and streptozotocin-diabetic rats.
Liver microsomal flavin-containing monooxygenase (FMO) activity towards thiobenzamide is two-fold increased in streptozotocin diabetic (insulin deficient) rats and mice and, to a lesser degree in congenital insulin resistant Ob/Ob mice. No difference in thermal stability appears between microsomal FMOs from both normal and diabetic rats. FMO has been purified to homogeneity from these two sources, with a 50-fold increase of specific activity. Their apparent molecular weight is respectively 50,000 and 49,000 and a discrete modification appears in the HPLC profiles of tryptic peptides from purified FMOs. They appear immunochemically very similar and present in equal quantity in microsomal membranes from both normal and diabetic rats, so that the increased activity cannot be ascribed to an increased concentration of the enzyme protein.
Animals↗
[Prenatal diagnosis by DNA analysis].
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DNA↗
Characterization of an arginine-specific protein kinase tightly bound to rat liver DNA.
A new protein kinase has been characterized among the proteins tightly bound to rat liver DNA and released by DNase I and RNase A treatment. This enzyme was separated by gel filtration from this released material. Its apparent molecular mass was found to be 34 kDa and it is made of a single unit. The main characteristic of this protein kinase is that it is arginine-specific. Isolation of phosphoarginine required the use of proteolytic enzymes at alkaline pH since the phosphate bond is highly acid-labile. This protein kinase is able to autophosphorylate and to phosphorylate a single chromosomal protein of 11 kDa also tightly bound to DNA. It uses ATP and dATP as phosphate donors and is cAMP-independent. Its optimal activity requires Mn2+ ions. Vanadate, spermine and heparin have no effect on its activity.
Animals↗
Rat liver nuclear protein kinases NI and NII. Purification, subunit composition, substrate specificity, possible levels of regulation.
Rat liver nuclear protein kinases NI and NII have been purified to homogeneity by an improved method. This method includes a casein-phosvitin-Sepharose column step, which separates the enzymes from the other chromosomal non-histone proteins, and a gel filtration at high ionic strength in the presence of a high concentration of protease inhibitors to separate the two enzymes from each other. NI has an apparent molecular mass of approximately 50 kDa and is composed of a single subunit. NII has an apparent molecular mass of 133 kDa and is composed of two subunits of identical molecular mass. The V and the Km of the two enzymes were determined for several substrates. Both enzymes phosphorylate chromosomal non-histone proteins with partly different specificities as shown by two-dimensional electrophoreses. When incubated in the absence of protease inhibitors, the enzymes were degraded into discrete polypeptides. Autophosphorylation of a polypeptide derived from NII was observed after incubation of the enzyme with ATP. This phosphorylation stimulated the enzyme activity. Several chromosomal proteins coeluted with NII from the casein-phosvitin-Sepharose column. They remained associated with the enzyme in sucrose gradients, during gel filtration performed at physiological ionic strength, and are dissociated at high ionic strength. These proteins were highly phosphorylated when the protein-NII complex was incubated with ATP.
Amino Acids↗
De novo mutation in hemophilia A established by DNA haplotype analysis and precluding prenatal diagnosis.
In a family with a single case of hemophilia A genetic counselling was requested by the pregnant aunt of the propositus. The haplotypes generated by two extra-genic RFLPs, at DXS52 (St14/Taq1) and DXS15 (DX13/BglII), and one intragenic RFLP in F8C (647/BclI) indicated that: she was not a carrier; the case of hemophilia resulted from a de novo mutation in a grandfather's gamete.
DNA↗
Separation of nuclear cAMP independent protein kinases NI and NII from their chromosomal protein substrates and enzyme inhibitors by the use of a casein-phosvitin-Sepharose column.
A casein-phosvitin-Sepharose chromatography column allows separation of nuclear protein kinases from their chromosomal phosphoprotein substrates and from at least some protein kinase inhibitors in a single step. The additional step of passing the eluted material through a partially hydrolyzed, dephosphorylated casein-Sepharose column separates the two protein kinases, NI and NII, from each other.
Animals↗
Nuclear accumulation of HMG1 protein is correlated to DNA synthesis.
The subcellular localization of HMG1 protein was studied by immunoelectron microscopy during growth of CV1 cells in culture and in confluent CV1 cells subsequently lytically infected with SV40. HMG1 was always detected in the cytoplasm of both non-infected and infected cells. On the other hand, this protein displayed a nuclear localization only in those cells active in cellular and/or viral DNA replication, that is, in actively dividing non-infected cells and in confluent cells following SV40 infection. The combination of electron microscope immunocytochemistry and autoradiography revealed that during SV40 lytic infection, HMG1 accumulates at sites of active viral DNA replication. Since HMG1 is a single-stranded DNA binding protein and acts in vitro as a physiological nucleosome assembly factor, we suggest that its presence in the nucleus is related to its requirement in the DNA replication process.
Animals↗
[Prenatal diagnosis of hemophilia A by analysis of DNA].
Early ante-natal diagnosis of haemophilia A and the detection of female carriers is now possible in some cases by analysis of DNA. The diagnosis may be established with a 100 p. 100 reliability in subjects with large deletion by direct analysis, and in 40 p. 100 of haemophiliac families by linkage studies with the intra-genic polymorphism revealed by the restriction enzyme BcII. Intensive research indicates that this percentage will increase in the near future. In the meantime, indicative studies are possible in other families. They consist in studying extra-genic restriction polymorphism. Over 90 p. 100 of families with haemophilia A may benefit from these studies using the probes currently available. Recombination, although not yet described, remains possible, and therefore ante-natal diagnoses made by the extra-genic probe should be controlled by foetal blood sampling at the 20th week of pregnancy.
DNA↗
Analysis and preparation of chromosomal high-mobility group proteins by ion-exchange high-performance liquid chromatography.
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Amino Acids↗
The 25 kDa protein kinase inhibitor present in liver cell is absent in fast growing HTC cells and is induced in sodium butyrate treated cells.
We have recently characterized a cAMP independent protein kinase inhibitor in rat liver. This inhibitor is absent or inactive in fast growing HTC cells and is induced according to exponential kinetics by sodium butyrate, a compound which arrests cell growth at the G1 phase of the cell cycle. It is suggested that the inhibitor could be involved in cell growth regulation.
Animals↗
A 25 000 dalton inhibitor of cAMP independent protein kinases present in rat liver HMG protein preparations.
A protein kinase inhibitor was found in rat liver cells as a component of HMG proteins. It is located in cytosol as well as in nuclei. It inhibits all tested cAMP independent protein kinases and has no effect on cAMP dependent protein kinases. This inhibitor is a 25 000 Da protein. It has no ATPase, phosphoprotein phosphatase or proteinase activity and is heat unstable.
Adenosine Triphosphatases↗
The protein kinases tightly bound to DNA are present in normal tissues and in regenerating liver, but strongly decreased in hepatomas.
We have previously described in rat liver two protein kinases tightly bound to DNA, one is serine-specific, the other arginine-specific. In this work we show that both enzymes are present in various rat tissues and in liver from various species. Both kinase specific activities are strongly decreased in methyl-DBA-induced hepatomas and in HTC cells but not in regenerating liver after hepatectomy. This decrease is then not related to cell proliferation.
Animals↗