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J D Bignon

Publications and source records attributed to J D Bignon.

78 records · Page 5Linked to original sources
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DNA-RFLP methods and interpretation scheme for HLA-DR and DQ typing.

DNA-restriction fragment length polymorphism (RFLP) typing is a well established and standard technique for identification of HLA-DR and DQ allotypes. We present a detailed review of methods for RFLP analysis and a scheme for interpretation of results. This scheme permits the routine identification of HLA-DR and DQ allotypes using the restriction endonucleases TaqI and either HindIII or MspI.

DNA↗
PubMedDate not supplied

Combined use of RFLP and PCR-ASO typing for HLA-DR-Dw and DQw typing.

Due to some limitations of restriction fragment length polymorphism (RFLP) analysis in HLA-DR-DQ typing, we present a combined use of RFLP and polymerase chain reaction (PCR)-allele-specific oligonucleotide (ASO) typing. This scheme consists in selectively amplifying the few RFLP ill-defined genes (DR1/DR'Br' and DR4-Dw subsets) using PCR with allele specific primers to avoid cross-hybridization.

Alleles↗
PubMedDate not supplied

Management of platelet and RhD maternal immunizations by PCR phenotypings after early amniocentesis.

This study evaluates the possibilities of prenatal diagnosis of maternofetal platelet and anti-RhD incompatibilities by using molecular typing on amniocytes. Twenty-four amniocenteses were performed between 15 and 35 weeks of gestation (WG), 19 times for study of the fetal karyotype and 5 times because of anti-D immunization. HPA-1, HPA-3 and HPA-5 platelet phenotypes using PCR-RFLP and RhD phenotypes using amplification-refractory mutation system PCR were assessed in amniotic fluid and compared with those of fetal (15 times) or newborn (9 times) blood and with parental phenotypes (46 blood samples). The four phenotypes were always determined in amniocytes, and no discrepancies with fetal blood or parental phenotypes were noted. The reliability and low iatrogenicity of this method makes it suitable for amniocentesis from 15 WG onward in any woman whose spouse is likely to be heterozygous. These allow radical change with a clear beneficial effect in obstetrical care of immunized women.

Adult↗
PubMedDate not supplied

[Test of differential anti-T and anti-B lymphocyte compatibility in renal transplantation. A partial solution to the problem of hyperimmune patients].

In view of their beneficial effect on the functional survival of transplanted kidneys, pretransplantation blood transfusions of haemodialysed patients have become routine procedure. At the same time, the number of hyperimmune patients awaiting transplantation has been increasing, as these are often excluded on account of positive cross-match. Cross-matching is usually done by testing recipients' sera against total donor's lymphocytes, so that positive cross-match due to specific anti-T cell cytotoxic antibodies cannot be differentiated from that due to anti-B cell antibodies. Differential anti-T cell and anti-B cell cross-matching showed no significant difference between the survival of 34 transplants with B cell-positive cross-match and that of 126 transplants with B cell-negative cross-match (67% and 60% respectively at 12 months). It also showed that anti-B cell antibodies had no adverse effect on the survival of transplants. The presence of antibodies or auto-antibodies with optimal cytotoxicity at 4 degrees C did not appear to correlate with a significantly longer transplant survival as compared to other transplanted patients. Finally, a high degree of a anti-T cell immunization or a strongly positive B cell cross-match on transplantation day did not seem to jeopardize transplant survival in a B-cell-positive cross-match population of transplanted patients. The differential cross-matching method has made it possible to successfully transplant a substantial number of hyperimmune patients: at least 62% of patients with B cell-positive cross-match also had positive total lymphocyte cross-match which would have precluded renal transplantation.

Antilymphocyte Serum↗