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Biomedical subjects

C Salmon

Publications and source records attributed to C Salmon.

At least 199 records · Page 11Linked to original sources
PubMed1978

[An acquired B antigen in a subject of A2 group].

Almost all cases of acquired B antigen have been found in individuals. This report concerns a group A2 patient with acquired B antigen. The family was not available for genetic studies. Nevertheless two facts were in favour of A2 genotype: 10 after acetylation of the patient's red cells the A1 reactivity which usually reappears or is increased on acquired B cells, did not appear. 20 The study of the serum alpha-N acetyl galactosaminyl transferase showed an optimal activity at pH7, as it is usually found in A2. The respective roles of anti acquired B antibodies, group A specific structures and bacterial enzyme properties in the occurrence of acquired B antigen are discussed.

ABO Blood-Group System↗
PubMed1978

The antigen Duclos. A new high frequency red cell antigen related to Rh and U.

An antibody is described which defines a new high frequency red cell antigen, Duclos, whose expression seems to require the presence of both U and Rh fundamental antigens. Apart from the antibody maker's own red cells the only nonreactive samples were from Rhnull U impaired individuals, one example of which was shown however to yield very slight amounts of antibody through absorption-elution tests. Rhmod U weak cells gave very depressed and Rhnull U positive or Rh common U negative cells moderately depressed reactions. The proposita's red cells had an apparently normal Rh-LW condition but their U antigen was significantly decreased. No further Duclos negative individual was found by screening 8,500 blood donors in the Paris area.

Aged↗
PubMed1978

alpha-N-acetyl-D-galactosaminyl- and alpha-D-galactosyltransferase activities in sera of cis AB blood group individuals.

Thirteen cis AB persons from five families were examined for serum glycosyltransferase activities associated with the biosynthesis of A and B blood group characters. Their transferases were generally homogeneous within one family, except for A2/cis AB genotypes, whose A enzyme level was similar to the A2 normal sera, but they varied from one family to another. These activities differed quantitatively and qualitatively from A, B and AB normal sera. Studies of A transferase showed variations in the pH-dependent curve, the effect of cofactors and the capacity of conversion of O red cells into A-active cells. Moreover, A and B transferases behaved differently with respect to their relative levels than did AB heterozygous normal sera. The results were discussed and it was suggested that a mutation of a single enzyme transferring both galactose and N-acetyl-galactosamine could explain these properties.

ABO Blood-Group System↗
PubMed1978

Effects of proteolytic enzymes and neuraminidase on the I and i erythrocyte antigen sites. Quantitative and thermodynamic studies.

The effects of neuraminidase and proteolytic enzymes on I and i reactivities was studied with I and i adult red cells, using radioimmunological methods. An enhanced reactivity after enzyme treatment is not exclusively due to a membrane charge reduction. The increase in site numbers and association constants bring about the gain of the cold agglutinin fixation. The release of N-acetylneuraminic acid residues gradually increases the I antigen site density of I red cells and the i site density of i red cells. Similar behaviour was observed after proteolytic enzyme treatment with papain, bromelin or ficin. The proteolytic treatment of I erythrocyte reveals underlying i receptors on these cells. Following membrane glycoprotein chain removal, anti-i antibodies are specifically fixed on I erythrocytes. The accessibility to antibodies of the determinants responsible for I and i erythrocyte activities was influenced significantly by steric hindrance factors. While N-acetylneuraminic acid release increased antibody affinities for the antigenic receptor, the removal of glycopeptide chains greatly diminished steric hindrance and brought about higher affinity constants. After enzyme treatment, the antigenic structures become more homogeneous in their reaction with antibodies. The heterogeneity of binding constants observed with antigenic determinants of non-treated erythrocytes is probably due to the wide range of spatial distribution of these receptors within the membrane.

Adult↗
PubMed1977

[Antigen Fyx: quantitative study of subjects FybFyx, FyaFyx and FyxFyx from two new families].

Two new families are described in which multiple examples of antigen Fyx are found in homo-and heterozygous states. The expression of the antigen is evaluated by conventional methods (agglutination scoring) and HD50 assays using a polybren-citrate autoanalyzer technique. Individuals from both families are tested in parallel with those from the family of the first known examples of homozygous FyxFyx described by Cedergren and Giles [2], and with 59 known FyaFyb and FybFyb controls. No consanguinity is found in the two families reported. Quantitative study of anti-Fyb absorption by red cells reveals that the expression of Fyb in individuals considered to be FybFyx is weaker than in FybFyb and even FyaFyb controls. HD50 assay data obtained in the control donors population seem to indicate that, in contrast to the admitted opinion, intermediate degrees of antigenic strength do exist between "normal" Fyb and Fyx the definition of which, based on quantitative criteria, remains unprecise. Using a new potent anti-Fy3 (AR), the expression of Fy3 displayed a slight and variable decrease in FyxFyx samples investigated.

Blood Group Antigens↗