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V Davé

Publications and source records attributed to V Davé.

21 records · Page 2Linked to original sources
PubMed1980

Blood group glycosyltransferase activities in plasma from blood chimera subjects.

Blood group glycosyltransferases (A and B) in plasma are mainly derived from other tissues, not from bone marrow where the blood group substances are synthesized. Therefore, it is possible to determine the original blood type of host subject and grafted cells by examining the enzyme activity in plasma from a chimera subject. Subject WD had 75-85% of O type cells and 15-25% of A1 type cells. A1 enzyme activity of the subject's plasma was the same as control A1 plasma, suggesting that subject WD is genetically A1O or A1A1 and O red cells are produced by OO bone marrow cells acquired in utero. Another subject EA has about 85% of B type and 15% of A1B type red cells. B enzyme activity of the subject's plasma is normal, but A enzyme activity is only 20% of normal level. Subject EA must be genetically BO or BB, and A gene is restricted to bone marrow cells acquired.

ABO Blood-Group System↗
PubMed1980

Membrane abnormality in red blood cells with weak type B expression.

The mechanisms of unusually weak blood group (A and B) expressions are not yet well understood. We examined properties of blood group galactosyltransferase (B-enzyme) and characteristics of red cell membrane components obtained from family members with A2Bm character. B-enzyme activity of the A1Bm plasma is in normal range, and kinetic properties (i.e., Km for UDP-Gal, Km for 2'-fucosyllactose, and pH optima) of B-enzyme from the A1Bm subjects are identical to that of normal B-enzyme. When A1Bm red cell were incubated with UDP-Gal and B-enzyme, the cells became strongly agglutinable with anti-B. When A1Bm membranes were incubated with B-enzyme or A-enzyme (i.e., blood group N-acetylgalactosaminyltransferase) and the appropriately labeled nucleotide sugar (UDP-Gal3H for B-enzyme and UDP-GalNAc3H for A-enzyme), significant incorporation of the sugar was observed. The amounts of the sugar incorporated into A1Bm membranes were about 40%-50% of that incorporated into O membranes at saturation, indicating that about one-half of H-sites remained unglycosylated in A1Bm red cells. Examination of radioactive components by isoelectric focussing revealed that the labeled components of A1Bm membranes were distinctively different from that of O membranes. Therefore, one can conclude that the weak B expression is not due to direct mutation of ABO locus, but due to a secondary consequence of genetic abnormality of a membrane component (or components) associated with blood group substances.

ABO Blood-Group System↗