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Biomedical subjects

C Doinel

Publications and source records attributed to C Doinel.

At least 55 records · Page 3Linked to original sources
PubMed1983

Study of blood group B antigen with a specific monoclonal antibody (anti-B, b-183).

A murine anti-B monoclonal antibody was obtained by the hybridoma technique. This antibody called anti-B (b-183) is of IgM nature; it is capable of agglutinating normal B, B3, Bx, cis AB and some acquired B red cells. Its association constant is 1.1 X 10(8) l/mol, and appears high compared to those of the monoclonal anti-A. This monoclonal anti-B was used to determine the number of B sites on B3 and Bx red cells.

ABO Blood-Group System↗
PubMed1981

Thermodynamic and immunological properties of a monoclonal antibody to human blood group A.

A murine anti-A monoclonal antibody was obtained by the hybridoma technique. This antibody, of an IgM nature, is capable of agglutinating A1, A2 and A3 red blood cells. Thermodynamic study confirmed its monoclonal character; its association constant is 1,6 10(6) l/mole. The enthalpy change of the antigen/antibody reaction is nul which indicates the absence of the role of temperature on antibody fixation. This weak affinity makes it necessary to concentrate the supernatant so as to enable use of these reagents under the same conditions as those used at present.

ABO Blood-Group System↗
PubMed1980

Relationship between I and H antigens. II. Study of the H and I deficient phenotypes.

H and I substances are present in the plasma and the saliva. In the plasma there is no quantitative relationship between H and I substances, whereas in the saliva only non-secretors produce I substance [shown by anti-Is serum, (Sti.)]. The study of I and H substances in the plasma and the saliva of H and I deficient subjects gives a better understanding and enables the completion of the classification of these rare phenotypes. The results also allow the proposal of a synthetic scheme of Is and H substances in the saliva.

Agglutination↗
PubMed1979

Human IgE response to the administration of blood components. II. Repeated gammaglobulin injections.

43 adults from a renal dialysis unit staff have received regularly spaced gamma-globulin administrations for hepatitis B prophylaxis. Several blood samples were collected over a prolonged period of time (160 days). Following gamma-globulin administration, anti-immunoglobulin antibodies of the IgE class were detected in 80% of this population, a fortnight after the first injection using serum absorptions on polymerized gamma-globulins or a specific inverse RAST method. The reactivity pattern of these IgE anti-immunoglobulin antibodies was similar to that observed for the anti-immunoglobulin antibodies with "limited specificity" detected by passive hemagglutination, in that they reacted with only one of the immunoglobulins of the panel used for their detection. A decrease of the overall IgE levels was observed in 62% of the subjects for a prolonged period of time following gamma-globulin administration. This suggests a feedback regulation mechanism for the reagin production in man, as it has already been observed in animals. A high incidence of anti-immunoglobulin antibodies of various classes was observed in this study. However, only a small number (4/43) of adverse reactions appeared following gamma-globulin administration. For some of these subjects, the presence of specific IgE anti-immunoglobulin, detected by the inverse-RAST technique, suggests a possible role of such antibodies in some intolerance reactions to gamma-globulin administration.

Absorption↗
PubMed1979

Induction of Tk polyagglutination by Bacteroides fragilis culture supernatants. Associated modifications of A B H and I i antigens.

Tk transformed red blood cells were obtained in vitro by treatment with supernatants from cultures of three different Bacteroides fragilis strains. The reactions of these cells with AB sera show that Tk is different from other known types of polyagglutination. Beside the already known modifications of A B H antigens, we found that Tk activated cells have an important modification of I and i antigens: both are reduced, and can even be completely destroyed.

ABO Blood-Group System↗
PubMed1979

Localization of blood-group A and I antigenic sites on inside-out and rightside-out human erythrocyte membrane vesicles.

Investigations of the fixation of 125I-labelled anti-A and anti-I antibodies onto rightside-out and inside-out membrane vesicles prepared from human A1 and OI erythrocytes, respectively, showed that both antibodies were bound to the rightside-out vesicles, giving clear evidence that blood group A and I antigenic sites are exclusively localized on the external surface of the membrane.

ABO Blood-Group System↗
PubMed1978

[I and i antigens of human erythrocytes : their detection by means of immunofluorescence technic and their changes during ontogenesis].

I and i antigens were detected by indirect immunofluorescence on human erythrocytes. 80% of the cord blood cells were brightly fluorescent with anti-i, 15% only with anti-I. In adult blood, this ratio is reversed, 2% only of the cells being intensively labelled with anti-i. The percentages characteristic of adult blood are established within the first 8 months of life.

Antigens↗
PubMed1976

[I antigenicity of the Bombay red cells].

Different homogeneous IgM cold agglutinins have been used to determine the antigen site density of Oh and OHm erythrocytes in comparison with O (H). The equilibrium constants and the delta Ho and delta S o have been measured. When H antigen is absent on the O red blood cells, there is no apparition of new I and i antigenic sites. Competition between gene products converting i into I and Hh genes for a common precursor substance appears unlikely. Nevertheless, the affinity of all antibodies tested increases with Oh and OHm cells and the thermodynamic parameters are accordingly modified. These results could be explained by: either a lesser steric hindrance in the absence of H antigen, the I determinants that are normally hidden by H antigen become more accessible, or by a modification of the molecular environment, as the interaction between fucosyl and N-acetyl residue of the penultimate sugar on the basic oligo-saccharidic chain is abolished. The structure of some I determinants may be modified, particularly of those which include the beta-D-Glu-NAc. Another explanation for these peculiar reactivities could be the substitution on the Bombay cells of this fucose by a neuraminyl residue. In the Sch. siblings, a heterozygous Hh subject was evidenced. His thermodynamic characteristics are nearing those of the hh propositus; the hypothesis of a competition between fucosyl and neuraminyltransferases for the same substrate is then proposed.

ABO Blood-Group System↗
PubMed1976

Groups of alpha-D- galactosyltransferase activity in sera of individuals with normal B phenotype. II. Relationship between transferase activity and red cell agglutinability.

In the Paris population of blood donors with normal B phenotype, two groups can be formed owing to their respective serum alpha-D-galactosyltransferase activity and red cell agglutinability with an anti-B antibody. Both parameters are closely correlated. The agglutinability groups partially overlap. In an African population from various ethnical origins, this correlation was observed only in some individuals. 11 among 20 subjects belonged to a third group defined by a high transferase activity. The third group with the strongest agglutinability previously described by GIBBS et al. [6] were not encountered. On the other hand, serum transferase activity varied inversely as agglutination scores with anti-H (Ulex). Both parameters are closely correlated but not in the same way in Caucasian as in African individuals. In the latter, this relation does not depend on the agglutinability group. The H antigen strength variability, according to ethnical origins, may explain these results.

ABO Blood-Group System↗
PubMed1976

Quantitative and thermodynamic measurements on I and i antigens of human red blood cells.

Different homogeneous IgM cold agglutinins (two anti-I, two anti-i and one anti-Il cross-reacting antibodies) have been used to determine the antigen site densities of adult I and i erythrocytes and of cord red cells. The equilibirium constants and the thermodynamic constants of these reactions have been determined. The two anti-I antibodies, which did not combine with i or cord red blood cells, recognized two different determinants on I red cells. The antigen density of the I Fla. receptor was 120,000 sites per erythrocyte and the standard enthalpy change (-deltaH degrees) of the reaction was 18 to 25 kcal/mole. The antigen density of the I Loi. determinant varied according to the red cells tested and the enthalpy change (-deltaH degrees) of these reactions was 50-65 kcal/mole. The i and cord erythrocytes reactive structures were more heterogeneous than those present on I erythrocytes. The equilibrium constants rapidly decreased as the temperature rose and the standard enthalpy changes (-deltaH degrees) ranged from 50 to 90 kcal/mole. Two types of i determinants were observed; one of the anti-i antibodies reacted mainly with an i component present on cord erythrocytes, the other antibody reacted with a different i component present on i adult red-cells. The determinants, recognized by the cross -reacting antibody on I red cells, differed fromthose on i or cord red cells in equilibrium constant, thermodynamic constants, index of heterogeneity of the reaction and in their sensitivity to formalin treatment.

Adult↗
PubMed1975

A correction to the autoanalyzer data for quantitative agglutination measurements.

The AutoAnalyzer was used for quantitative measurements of antibody agglutinating activity by a Polybrene agglutination technique. Since the continuous flow system introduces an experimental error to the determination of true agglutination percentage, it is necessary to apply a correction factor. The experimental method of correction is described.

Autoanalysis↗