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M Vidaud

Publications and source records attributed to M Vidaud.

138 records · Page 8Linked to original sources
PubMed1987

Mixed blood chimerism in T cell-depleted bone marrow transplant recipients: evaluation using DNA polymorphisms.

We have used DNA sequence polymorphism analysis to document engraftment after T cell-depleted bone marrow transplantation (BMT), with a selected panel of four DNA probes. In contrast to nondepleted BMT recipients, the patients who received T cell-depleted marrow exhibited a mixed blood chimerism. This mosaicism was observed before graft failure or relapse in six patients. However, in five other patients, this mixed chimerism was not followed by these complications with a follow-up of 9 to 31 months after transplantation. Our results support the hypothesis that transplanted bone marrow T cells may help to maintain engraftment by eliminating host cells that can cause graft failure.

Adult↗
PubMed1986

Hemoglobin S Antilles: a variant with lower solubility than hemoglobin S and producing sickle cell disease in heterozygotes.

We have found a sickling variant, Hb S Antilles, alpha 2 beta 2(6 Glu----Val, 23 Val----Ile), that has the same electrophoretic mobility as Hb S but a distinct isoelectric focus and produces sickling in the carriers of the Hb A/S Antilles trait. The carriers' erythrocytes tend to sickle at O2 partial pressures similar to those that induce sickling in Hb S/C disease. Pure deoxy-Hb S Antilles is 50% as soluble as deoxy-Hb S (saturating concentration = 11 g X dl-1 compared to 18.4 for Hb S). Dilute solutions of pure Hb S Antilles have a lower oxygen affinity than those of Hb A or Hb S (partial pressure for 50% binding is 9 mm Hg compared to 5.5 mm Hg for Hb A or S at pH 7.00). A/S Antilles erythrocytes have a much lower oxygen affinity than A/S cells; this is further decreased in dense cells fractionated on a Percoll density gradient. Their oxygen equilibrium curves had anomalous shapes like those of S/S cells. Fiber formation in the erythrocytes of Hb S Antilles carriers is clearly due to its low solubility and oxygen affinity, showing that heterozygosity for this hemoglobin presents another sickle cell syndrome and suggesting that Hb S heterozygotes who exhibit symptoms of sickle cell disease should be carefully screened for double mutations.

Amino Acid Sequence↗
PubMed1986

A de novo intragenic deletion of the potential EGF domain of the factor IX gene in a family with severe hemophilia B.

We have studied a family of three patients who were severely afflicted with hemophilia B without inhibitor for their factor IX genes through the use of factor IX cDNA and genomic DNA probes. The patients had detectable (30% of normal) factor IX antigen. DNA hybridization analysis demonstrated that these patients had a partial intragenic deletion in their factor IX gene. This 2.8-kb deletion included exon d and the surrounding sequences. This exon codes for the amino acid sequence from No. 47 through 84 of the factor IX protein and contains its first potential EGF domain; the de novo occurrence of the mutation in the grandfather's germ cells was established by linkage analysis. This specific gene has been named F IXStrasbourg.

Chromosome Deletion↗
PubMed1986

[DNA polymorphism in beta-thalassemia: a study of 15 families in Tunisia].

In order to perform prenatal diagnosis of beta-thalassemia by DNA analysis in Tunisia, we investigated molecular defects and their frequencies. We have determined which haplotypes are associated with beta zero or beta +-thalassemia phenotypes. Six of the haplotypes described by Orkin were observed among 15 patients homozygous for beta zero (11) or beta +-thalassemia (4). We also investigated the molecular defects. The frameshift mutation in codon 6, characterized by Mst II seems more frequent than the beta 39 non sense mutation indicating that Tunisian patients differ from other Mediterranean patients from Algeria or Italy. Results concerning beta +-thalassemia are too preliminary to draw any conclusion. The study is currently being enlarged with other molecular probes and restriction enzymes.

DNA↗
PubMed1986

[Alpha-thalassemia in Tunisia: molecular bases of hemoglobinosis H].

We report the study by restriction mapping of alpha genes in a case of Hb H disease in Tunisia. The genotype is: -alpha/-alpha which by itself is not usually responsible for the HbH phenotype. We postulate that the two remaining alpha genes are dysfunctional, this is under study.

Child↗
PubMed1985

[Association of hemoglobin E and thalassemia].

Double heterozygotism Hb E-beta zero thalassemia was discovered in two children born to an Alaouite Syrian family. Clinical, biological and radiological findings were similar to those in Cooley disease. Splenectomy allowed reduction in the frequency of blood transfusions. Hb E disease is frequent in South East Asia and results in a mild hemolytic anemia in homozygous patients. Hb E disease is a thalassemia syndrome with decrease production of beta E RNA messenger, and imbalanced alpha/beta E chains. Association with the thalassemia gene increases the imbalanced of chain synthesis explaining the severity of the disease. These were the first cases of Hb E-thal in Syria.

Child↗
PubMedDate not supplied

Improved DNA markers for efficient analysis of fragile X families.

We report the characteristics of two new probes that detect BclI RFLPs useful for analysis of fragile X families. With these two probes and a single blot, 34% of women are heterozygous both for the proximal marker DXS105 (closer to the fragile X locus than the factor IX gene) and for the distal markers DXS52 or the factor VIII gene. Combined with the analysis of previously described polymorphic markers, it is possible to have a majority of families fully informative for flanking markers using a limited number of probes and restriction digests.

DNA Probes↗
PubMedDate not supplied

Human TIP49b/RUVBL2 gene: genomic structure, expression pattern, physical link to the human CGB/LHB gene cluster on chromosome 19q13.3.

Bacterial DNA helicase RuvB protein is an essential component in homologous recombination and DNA double-strand break repair. Here, we report the gene structure of TIP49b/RUVBL2, a second putative human homologue of the bacterial RuvB gene. This gene contains 15 exons and 14 introns. The TIP49b/RUVBL2 open reading frame encodes a protein of 463 amino acids, showing 43% identity with the RUVBL1 protein. The TIP49b/RUVBL2 gene is physically linked to the human CGB/LHB gene cluster on chromosome 19q13.3. Genomic sequence analysis revealed that the TIP49b/RUVBL2 gene is very close (55 nucleotides in length) to the LHB gene, in the opposite orientation. The very close co-location of the mouse homologues of the human TIP49b/RUVBL2 and LHB genes was also conserved on mouse chromosome 7. Co-ordinated transcriptional regulation between the TIP49b/RUVBL2 and LHB genes was not observed. TIP49b/RUVBL2, like RUVBL1, was expressed ubiquitously in all human tissues examined and more strongly in testis. As TIP49b/RUVBL2 is expected to be involved in recombination repair and is located in a chromosome region frequently amplified in breast cancer, we quantified TIP49b/RUVBL2 gene expression by using real-time quantitative RT-PCR in a series of breast tumour samples. None of the tumour samples showed an altered TIP49b/RUVBL2 transcription level relative to normal breast tissue.

ATPases Associated with Diverse Cellular Activitie↗
PubMedDate not supplied

CCND1 mRNA overexpression is highly related to estrogen receptor positivity but not to proliferative markers in primary breast cancer.

To elucidate the role of CCND1 alterations in sporadic breast cancer we investigated the possible link between CCND1 mRNA levels versus estrogen-receptor (ER) status and a proliferation marker, S-phase fraction (SPF), measured by flow cytometry. CCND1 expression was quantified by means of real-time quantitative RT-PCR in a well-characterized series of 33 primary breast cancer patients. Eighteen tumors (54.5%) showed CCND1 overexpression ranging from 3.3 to 29.5 times the level observed in normal breast tissue. Seventeen (94.4%) of the 18 cases with CCND1 overexpression were ER-positive compared to seven (46.7%) of the 15 cases with normal CCND1 expression (p=0.0074). CCND1 overexpression was independent of SPF and DNA-ploidy status. These data suggest that the CCND1 gene does not act as an oncogene responsible for more rapid cell proliferation in breast cancer, but could be involved in the regulation of hormone sensitivity associated with ER.

Adult↗