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Biomedical subjects

J Ducos

Publications and source records attributed to J Ducos.

At least 55 records · Page 3Linked to original sources
PubMed1980

HLA-a, B typing in Basque and other Pyrenean populations.

Fourteen HLA-A and 18 HLA-B antigens were studied in three samples of Pyrenean populations: 198 unrelated individuals of a "Pays Basque" group; 212 non-Basque individuals from a valley in Bearn, l'Ouzom; and 73 non-Basque individuals from the neighboring valley of Bareges. The results in the Basque and the non-Basque people from l'Ouzom were comparable: the gene frequencies of HLA-A29, Aw19.2, B17 were increased and the haplotypes HLA-Aw19.2, B18; A29, B12; A2, B5; A1, B17 were found frequently with a striking linkage disequilibrium; HLA-B18 had an increased gene frequency in all these Pyrenean populations, while Bw35 was frequent in l'Ouzom and Bareges, but not among the Basques. The characteristics of Bareges were very different: the gene frequencies of HLA-A2, A11, B7 were increased while the frequency of HLA-B5 was low; the most characteristic haplotypes were HLA-A2, B12; A2, B18; A11, Bw35; A11, B27. It is interesting to note discrepancies between ethnic and HLA classification of the Basques and the non-Basque population of l'Ouzom. The HLA characteristics are quite different in the Hareges sample, more closely resembling those of Northern Europe.

Ethnicity↗
PubMed1980

High frequency of the properdin factor Bf F1 and its linkage to HLA in French Basques.

We studied 201 unrelated French Basque individuals for HLA and Bf polymorphisms. The haplotypes of eighty-seven of them were deduced from family studies. The results show the frequency of the Bf F1 allele (0.1393) which is the highest one currently reported. They confirm the high frequencies of HLA-Aw19.2 and B18 previously reported in that population and show that a whole haplotype with strong linkage disequilibria, namely Aw19.2, Cw5, B18, Bf F1, DRw3 is frequent. On the other hand, the gene frequency of Bf S is decreased (0.5497) as compared with the other European Caucasoïd populations, while a slight increase in the Bf F gene frequency (0.2960) appears. These results point out that it is of importance to consider the genetic background choosing the population where linkage disequilibria are to be studied.

Alleles↗
PubMed1980

Antiglobulins in normal human sera which react with baboon Ig G.

Antiglobulins of the Ig M class which react with the Ig G of baboons have been discovered in approximately half the number of normal human sera investigated by the technique of hemagglutination of red blood cells coated with baboon immune serum. The frequency of these antiglobulins is significantly higher among patients suffering from seropositive rheumatoid arthritis but there is no correlation with the presence of Milgröm-type antiglobulins. The inhibition of several sera containing these antiglobulins by the sera of baboon of different species is also reported.

Animals↗
PubMed1978

[Critical study of techniques for the detection of "light" rheumatoid factors (author's transl)].

In a number of cases of true rheumatoid arthritis, it is not possible to demonstrate the presence of 19 S "heavy" rheumatoid factors by the Waaler-Rose and globulin latex techniques. However, in some of them, 7 S rheumatoid factors are suspected. Three techniques for the detection of these "light" rheumatoid factors are described and critically evaluated. The authors report their own experience of the immuno-absorption and indirect immunofluorescence technique performed on 156 sera from RA patients. Immuno-absorption is not felt to be a reliable technique on several grounds. Indirect immunofluorescence is of value only in the diagnosis of seronegative rheumatoid arthritis where it provides information in addition to that offered by classical techniques. It is positive in 53.3% of seronegative rheumatoid arthritis sera.

Arthritis, Juvenile↗
PubMed1978

[Irregular antibody screening by Groupamatic at the Paris (C.N.T.S.) and Toulouse (C.R.T.S.) blood transfusion centers].

We report here the experience of 3 years of irregular antibody automated screening with Groupamatic, that is to say of 661,511 samples tested in Paris and 269, 162 samples tested in Toulouse. The positive reactions in Paris were 16,296 (2.46%) out of which 2,021 irregular antibodies were identified (0.30%). The positive reactions in Toulouse were 8,266 (3.07%) out of which 2,138 irregular antibodies were identified (0,79%). The difference between the number of screened positive reactions and the identified one is due to false positive reactions (half of the cases) and to autoantibodies whose number is roughly the same than the number of identified alloantibodies. During the years 1970, 1971 and 1972, the irregular antibodies were systematically screened in Toulouse on all blood donors with a manual technique on opaline plate using enzyme treated red cell tests (papain). 7,147 positive reactions were detected, out of 240,080 tests (2.98%). 1,954 (0,81%) were alloantibodies and 1,529 (0.64%) autoantibodies; 3.455 were false positive reactions and 209 were non identified antibodies. These figures are superimposed with those obtained with Groupamatic during the following years, thus pointing out the interest of this equipment.

Autoanalysis↗
PubMed1978

Lymphocytotoxic antibodies and antiglobulins in renal allograft recipients. Correlative study with acute rejection.

In 45 patients who received kidney transplants, both homologous and heterologous human antiglobulins (anti-Ig) and HLA cytotoxic antibodies have been studied before and after transplantation and in some cases after nephrectomy. A similar study has been performed in a control group of 1,019 healthy blood donors and in 130 patients with acute or chronic glomerulonephritis. After transplantation, homologous anti-IgG were found in 60% of the patients, as compared with 3.5% in the healthy blood donors and 21% in patients with various forms of glomerulonephritis. This difference is particularly striking in sera obtained prior to nephrectomy; the presence of anti-IgG and cytotoxic antibodies in the same patient being significantly associated with early transplant failure. Anti-IgA were found in 75% of the patients with transplants and in 37% of the patients with glomerulonephritis. There was no relationship between the anti-IgA and the outcome of the graft. On the other hand, heterologous anti-Ig were unchanged in the three groups investigated. The mechanism of formation of the anti-IgG is not clear. They are probably antibodies against antigenic structures of the patient's own antibodies, previously combined with a soluble antigen or an antigen on the transplant that has undergone molecular transformation in the course of this reaction. Their pathogenic role, although not demonstrated, can be strongly suspected, and, in a practical way, screening for the anti-Ig in kidney transplant recipients could be of value as a prognostic test.

Antibodies↗
PubMed1976

[Certain human anti-Gm antisera have an antiglobulin reacting specifically with IgG of baboons].

An antiglobulin anti-Baboon IgG exists in human sera [with or without an anti-Gm (1)]. There is no correlation between this antiglobulin and another one of the Milgröm type. Its occurrence is not characteristic of the anti-Gm sera. Therefore, it cannot explain the different specificities between the two types of anti-Gm (1) discordant at the level of non-human Primate immunoglobulins.

Animals↗
PubMed1976

[Practical interest of a micromethod for neuraminidase treatment of lymphocytes in transplantation immunology (author's transl)].

Vibrio cholerae neuraminidase treatment increases the cell sensitivity to complement and antibodies cytotoxic action. This property can be applied to the microlymphocytotoxicity technic for antibodies study in dialysed and kidney transplanted patients and for pretransplantation cross-matches. The enzymatic treatment usually employed needs a great deal of lymphocytes submitted in a second step to antibodies cytotoxic action. But this method appeared difficult to be routinely applied. We developed a simpler method consisting in treating only the lymphocytes needed to perform the test, on the reaction plate itself. This method gives the same results as the classical enzymatic treatment: the intensity of the weakly positive reaction is strongly increased, after pretreatment of cells; in certain cases, it allows one to detect cytotoxic antibodies not revealed without neuraminidase. These antibodies can be related (or not) to HLA system but practically the more important fact is the ability of this method to reveal an eventual incompatibility.

Antibodies↗
PubMed1975

A case of Ax phenotype transmitted by an A2B parent.

The authors report a family in which the father is Ax, the mother B, the paternal grandmother Ax; 3 children out of 6 are A2B and the other three Ax. One of A2B children is married to an O subject, and she had a son of phenotype Ax. It was observed that Ax gene in position trans of a B gene behaves phenotypically as an A2.

ABO Blood-Group System↗