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S F Parsons

Publications and source records attributed to S F Parsons.

45 records · Page 3Linked to original sources

Individuals lacking the Gerbich blood-group antigen have alterations in the human erythrocyte membrane sialoglycoproteins beta and gamma.

Membranes from erythrocytes with a new Gerbich (Ge)-negative phenotype (Leach phenotype), as well as those from two other Ge-negative phenotypes, were examined. Whereas cells of the Leach phenotype apparently lack three minor sialoglycoproteins (beta, beta 1 and gamma), the membranes of Ge- Yus- and Ge- Yus+ erythrocytes apparently lack beta- and gamma-sialoglycoproteins but contain additional diffusely migrating components of apparent Mr 30 500-34 500 and 32 500-36 500 respectively. Immunoprecipitation experiments showed that the abnormal components of both Ge- Yus- and Ge- Yus+ erythrocytes reacted with two monoclonal antibodies, BRIC 4 and BRIC 10. These antibodies have been shown to react with sialoglycoproteins beta and beta 1 in normal erythrocytes. Cytoskeletal preparations from Ge- Yus- and Ge- Yus+ erythrocyte membranes contained the abnormal components. In contrast with cells of the Leach phenotype, which are elliptocytic, Ge- Yus- and Ge- Yus+ were of normal shape, despite their apparent lack of beta- and gamma-sialoglycoproteins. It seems likely that the abnormal components in these cells contribute to their normal shape. Ovalocytic erythrocytes were shown to incorporate more radioactivity in the sialoglycoprotein-beta 1 region than normal erythrocytes after labelling by the periodate/NaB3H4 technique. It is suggested that abnormal components in Ge- Yus- and Ge- Yus+ erythrocytes result from chromosomal misalignment with unequal crossing-over at meiosis between the genes giving rise to beta-, beta 1- and gamma-sialoglycoproteins.

Antibodies, Monoclonal↗

Two individuals with elliptocytic red cells apparently lack three minor erythrocyte membrane sialoglycoproteins.

We have studied the erythrocytes of two individuals (P. L. and K. W.) who lack the Gerbich (Ge) blood-group antigen. The erythrocytes of P. L. and K. W. were not reactive with two monoclonal antibodies (NBTS/BRIC 4 and NBTS/BRIC 10) which reacted with normal erythrocytes. The membranes of P. L. and K. W. erythrocytes appeared to lack three minor sialoglycoproteins (beta, beta 1 and gamma). These three minor sialoglycoproteins were found to be associated with the cytoskeletons of normal erythrocytes. Approx. 10% of the erythrocytes of P. L. and K. W. were frankly elliptocytic. We suggest that one or more of the minor sialoglycoproteins may play a part in maintaining the discoid shape of the human erythrocyte.

Blood Group Antigens↗

Glycophorin as a possible receptor for Plasmodium falciparum.

Human red cells deficient in glycophorin B are partly resistant to invasion by Plasmodium falciparum and become completely resistant when glycophorin A is removed from their surface by trypsin treatment. Similar treatment of cells which have a hybrid glycophorin molecule renders them glycophorin-deficient and resistant to invasion. Tn and Wrb -ve cells with defined alterations in glycophorin A or B are also resistant to invasion. These findings suggest that both glycophorins A and B are involved in parasite invasion, indicate which parts of these molecules may be involved in this process, and provide the basis for a tentative model of parasite/red-cell interactions.

Blood Group Antigens↗

NBTS/BRIC 8. A monoclonal anti-C3d antibody.

A stable mouse hybridoma line secreting monoclonal anti-C3d antibody (NBTS/BRIC 8) was produced. Ascitic fluid containing BRIC 8 can be used at a final dilution of 1 to 5000 to provide an excellent antiglobulin reagent when mixed with a conventional polyclonal rabbit anti-human IgG serum.

Animals↗

Evidence that the Lub blood group antigen is located on red cell membrane glycoproteins of 85 and 78 kd.

A murine monoclonal antibody of specificity anti-Lub was produced. Immunoblotting of the electrophoretically separated components of membranes from Lu(b+) red cells with the monoclonal antibody identified two glycoproteins of relative molecular mass 85 and 78 kd, respectively. The expression of Lub antigenic activity on these glycoprotein components was shown to be dependent on the presence of one or more N-glycosidically linked oligosaccharides and on the presence of disulphide bonding.

Antibodies, Monoclonal↗