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T Feizi

Publications and source records attributed to T Feizi.

At least 199 records · Page 11Linked to original sources
PubMed1979

Multiplicity of molecules carrying blood-group-I antigen on erythrocyte membranes.

A human serum containing a monoclonal anti-(blood-group I) antibody was used to investigate the distribution of blood-group-I antigen on erythrocyte membrane components. Sodium dodecyl sulphate/polyacrylamide-gel-electrophoresis profiles of immuneprecipitates by using 3H-labelled (by the galactose oxidase/NaB3H4 method) and 125I-labelled solubilized stroma were compared. Different radioactive profiles were revealed by the two radiolabelling methods. In the immunoprecipitates the predominant 125I radioactivity within the gel had the electrophoretic mobility of Band-3 protein (apparent mol.wt. 90 000--100 000), whereas the 3H radioactivity revealed a diffusely migrating component(s) (apparent mol.wt. range 40 000--70 000) in addition to radioactivity compatible with glycolipids at the dye front. The diffusely migrating 3H-labelled component was shown to have a similar electrophoretic mobility to a subpopulation of erythrocyte poly(glycosyl)ceramides with blood-group-I activity.

Blood Group Antigens↗
PubMed1979

Three types of blood group I specificity among monoclonal anti-I autoantibodies revealed by analogues of a branched erythrocyte glycolipid.

Blood group I activities of the purified glycosphingolipid lacto-N-iso-octaosyl ceramide (Fromula: see text) and 8 of its analogues have been evaluated with 11 anti-I sera including 5 anti-I sera previously tested. All but one of the antisera were inhibited by the lacto-N-iso-octaosyl structure. Three types of I-specificity could be distinguished although none of the anti-I sera was identical in its inhibition patterns with the nine glycophingolipid analogues. The anti-I sera Ma and Woj represent the first type and require an intact Galbeta1 leads to 4GlcNAcbeta1 leads to 6 chain, the anti-I sera Step, Gra, Ver, and Ful represent the second type which requires Galbeta1 leads to 4GlcNAcbeta1 leads to 3 chain with branching, and the anti-I sera Phi, Da, Sch, and Low belong to the third type which requires both branches to be intact. Anti-I antibodies varry in their ability to react with their antigenic determinants in the presence of external substitutions with alpha-linked galactose or sialic acid.

Antibody Specificity↗
PubMed1978

Blood-group-Ii-active gangliosides of human erythrocyte membranes.

More than ten new types of gangliosides, in addition to haematoside and sialosylparagloboside, were isolated from human erythrocyte membranes. These were separated by successive chromatographies on DEAE-Sephadex, on porous silica-gel columns and on thin-layer silica gel as acetylated compounds. Highly potent blood-group-Ii and moderate blood-group-H activities were demonstrated in some of the ganglioside fractions. The gangliosides incorporated into cholesterol/phosphatidylcholine liposomes stoicheiometrically inhibited binding of anti-(blood-group I and i) antibodies to a radioiodinated blood-group-Ii-active glycoprotein. The fraction with the highest blood-group-I-activity, I(g) fraction, behaved like sialosyl-deca- to -dodeca-glycosylceramides on t.l.c. Certain blood-group-I and most of the -i determinants were in partially or completely cryptic form and could be unmasked by sialidase treatment. Thus the I and i antigens, which are known to occur on internal structures of blood-group-ABH-active glycoproteins in secretions, also occur in the interior of the carbohydrate chains of erythrocyte gangliosides.

Blood Group Antigens↗
PubMed1977

Studies on the heterophile antibodies of infectious mononucleosis. I. Separation of four antibody populations, one of which contains lymphocytotoxic activity.

With the aid of insolubilized immunoadsorbents made with glycoproteins, extracted from cow red blood cells (RBC), and with guinea-pig kidney tissue, heterophile antibody populations of the Paul--Bunnell type and the Forssman type were eluted from infectious mononucleosis sera. Two Paul--Bunnell-type antibody populations were separated on the basis of their affinity for cow RBC antigens. The lymphocytotoxic antibodies in the infectious mononucleosis sera were eluted among the low-affinity Paul--Bunnell antibodies.

Adult↗
PubMed1977

An immunoglobulin heavy chain variable region (VH) marker associated with cross-reactive idiotypes in man.

The VH specificities of two rabbit antisera raised against the H chains of two human IgM cold agglutinins were studied with the aid of proteins on which the VH sequence data are available. They were found to recognize a new VH antigen (VHMar), which may represent a subgroup of VHI. This antigen is found on anti-Ii antibodies which have cross-reactive idiotypes. It is moderately well-expressed in normal gamma globulin and strongly expressed on 8% of unselected myeloma and macroglobulinaemia proteins. There is evidence to suggest that a proportion of the cross-reactive idiotypes among the anti-Ii antibodies involve this VH antigen.

Agglutinins↗
PubMed1976

Kappa chain (V kappa III) subgroup-related activity in an idiotypic anti-cold agglutinin serum.

In a search for H- or L-chain-related cross-idiotypic specificity among human anti-I and anti-i cold agglutinins, two idiotypic antisera raised against the IgMkappa cold agglutinin Da were tested for their binding activity to isolated cold agglutinin H and L chains. Negligible H-chain binding activity was found, but there was high-titre L-chain binding activity in one of the antisera. This was an unsuspected VkappaIII subgroup activity which enabled the classification of VkappaIII proteins into three subgroups. The kappa chains of five out of six anti-I and anti-i cold agglutinins belonged to the antigenically most active VkappaIII subgroup. Absorption of the idiotypic antiserum with a Bence Jones protein of this latter subgroup did not appreciably alter the precipitating cross-idiotypic activity of the antiserum when tested with intect cold agglutinins. However, these studies do not rule out the possible existence of a VkappaIII subgroup-associated conformational antigen in an intact Fab region, which is seen as a 'cross idiotypic' antigen by heterologous (rabbit anti-human) antisera.

Agglutinins↗
PubMed1975

Blood-group precursors and cancer-related antigens.

Glycoprotein extracts from colonic tumours were tested for blood-group precursor-like activities using human anti-I and anti-i cold agglutinins as reagents. Substantial activity was detected in the high-molecular-weight fractions of two metastatic tumours. A carcinoembryonic antigen (C.E.A.) fraction from one of these tumours was also active. The C.E.A. and the precursor-like activities were located on separate molecules. These data indicate that the levels of precursor-like antigens in entodermal tumours and their possible diagnostic value warrant detailed investigation.

Antigens, Neoplasm↗