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Biomedical subjects

M E Reid

Publications and source records attributed to M E Reid.

At least 181 records · Page 10Linked to original sources
PubMed1990

Cromer-related blood group antigens and the glycosyl phosphatidylinositol-linked protein, decay-accelerating factor DAF (CD55).

Cromer-related blood group antigens are located on the complement regulatory glycoprotein, decay-accelerating factor (DAF). DAF is not detectable on red cells from individuals with a Cromernull) phenotype (termed Inab), which is probably an inherited condition. DAF is also absent from a subpopulation of red cells (PNH) III) from patients with paroxysmal nocturnal hemoglobinuria (PNH), an acquired hematological defect. PNH III red cells, like Inab cells, lack all the Cromer-related antigens described to date.

Journal Article↗
PubMed1989

Beta and beta-related sialoglycoproteins in the human red cell membrane.

Recent studies on beta and beta-related sialoglycoproteins (SGPs) in the human red cell membrane are reviewed. These SGPs are transmembrane glycoproteins with conserved cytoplasmic domains that interact with the membrane skeleton via protein 4.1. The inheritance of these SGPs is described, and the possible locations of Gerbich (Ge2 and Ge3) and Wb blood group antigens reviewed.

Blood Group Antigens↗
PubMed1989

Exposure of cryptantigens on red blood cell membranes in patients with acquired immune deficiency syndrome or AIDS-related complex.

Patients with acquired immune deficiency syndrome (AIDS) or AIDS-related complex (ARC) are subject to recurrent and severe infections due to organisms known to cause red blood cell membrane modifications. These red cell modifications include the exposure of novel carbohydrate cryptantigens that can react with naturally occurring antibodies and potentially result in hemolysis. We examined the frequency of cryptantigen exposure on the surface of red cells from AIDS/ARC patients. Blood samples from 108 patients with AIDS/ARC and from 65 non-AIDS/ARC patients were tested for most common forms of cryptantigens. The lectin Arachis hypogaea agglutinated red cells from 7% (8/108) of the AIDS/ARC patients and 3% (2/65) of non-AIDS/ARC patients, indicating the presence of T, Tk, or Th cryptantigen exposure. One sample from an AIDS patient with E. coli sepsis had T activation with polyagglutinable red cells. None of the samples showed evidence of exposed Tn or acquired B antigens. These results show that red cell cryptantigen exposure does occur in AIDS patients with a prevalence similar to that previously reported in patients with sepsis or malignancy. For this reason, and because polyagglutination has been associated with in vivo hemolysis, cryptantigen exposure should be considered in the differential diagnosis in AIDS patients with suspected immune hemolysis; it can be tested for by performing a minor crossmatch with ABO compatible serum.

ABO Blood-Group System↗
PubMed1988

Signal transduction by glycophorin A: role of extracellular and cytoplasmic domains in a modulatable process.

Binding of ligands to the extracellular region of the erythrocyte transmembrane protein glycophorin A induces a decrease in membrane deformability. Since the property of membrane deformability is regulated by the skeletal proteins on the cytoplasmic side of the membrane, this suggests that ligand binding may initiate a transmembrane signal. To further study this process, we examined which domains of the extracellular region of glycophorin are involved in signal transduction and whether the cytoplasmic domain of the molecule is necessary for transmitting the signal. Using the ektacytometer, we compared the effect on deformability of four monoclonal antibodies that detect different epitopes on glycophorin A. We found that 9A3 (which recognized the amino terminus of glycophorin) caused a 5.8-fold increase in rigidity, R-10 and 10F7 (which recognized epitopes in the mid-region of the extracellular domain) caused a 10.8-fold increase in rigidity and B14 (which binds to glycophorin close to the membrane) caused a 18-fold increase in rigidity. Further, a direct relationship was observed between the degree of antibody-induced rigidity and the amount of glycophorin A that became associated with the skeletal proteins in a Triton shell assay. In Miltenberger V erythrocytes, which contain a hybrid sialoglycoprotein with no cytoplasmic domain, antibody binding did not induce an increase in rigidity. These results imply that glycophorin A is capable of a modulatable form of transmembrane signaling that is determined by the extracellular domain to which the ligand binds, and the cytoplasmic domain of glycophorin A is crucial for this process.

Antibodies, Monoclonal↗
PubMed1988

Transient reduction in erythrocyte membrane sialoglycoprotein beta associated with the presence of elliptocytes.

Erythrocyte membranes from an anaemic patient receiving gold therapy for rheumatoid arthritis had reduced beta-sialoglycoprotein (beta-SGP) content but normal expression of sialoglycoproteins alpha, delta and gamma. Elliptocytes were present in the peripheral blood. The serum of the patient contained anti-beta-SGP which did not appear to bind to her own cells. It reacted with all erythrocytes apart from beta-SGP deficient Leach phenotype cells. The antibody was inhibited by purified beta-SGP from normal red cells, bound to beta-SGP on immunoblots and also reacted with the abnormal beta-related-SGP in erythrocyte membranes of both the Gerbich type and Yus type of Gerbich negative. Two years later the patient was no longer anaemic, no elliptocytes were seen in her peripheral blood film and her erythrocyte membranes had normal beta-SGP content. Antibody was no longer present in her serum and antibody from the earlier sample now reacted with the patient's erythrocytes. Erythrocyte membrane beta-SGP is known to be important in the maintenance of normal cell shape. It is likely that the transient occurrence of elliptocytes in the patient resulted from the concurrent temporary reduction in beta-SGP content of her erythrocyte membranes.

Arthritis, Rheumatoid↗
PubMed1988

Immunochemical specificity of autoanti-Gerbich from two patients with autoimmune haemolytic anaemia and concomitant alteration in the red cell membrane sialoglycoprotein beta.

Blood samples from two patients with autoimmune haemolytic anaemia, whose autoantibodies failed to agglutinate certain examples of red cells that lack Gerbich blood group antigens, were studied using immunochemical analyses. One of these autoantibodies differed from all other anti-Ge in that it showed a unique beta sialoglycoprotein (SGP) specificity. It reacted with normal beta but not with the abnormal beta-related SGPs associated with Gerbich-negative red cells of the Gerbich and Yus types. Red cells from this patient had an alteration of beta SGP, while the alpha, gamma and delta SGPs appeared to be normal. The autoantibody from the other patient did not show this unique characteristic. Its immunochemical specificity was similar to alloanti-Ge3 in that it reacted with both beta and gamma SGPs from normal red cell membranes and with the abnormal beta-related SGPs found in red cell membranes from individuals with Gerbich-negative red cells of the Yus type. Red cells from this patient could not be analysed because she had recently received a massive transfusion of red cells.

Adolescent↗
PubMed1988

Prevalence of ABO maternal-infant incompatibility in Asians, Blacks, Hispanics and Caucasians.

Previous studies suggest that race is a risk factor in ABO hemolytic disease of the newborn (ABO-HDN). In order to compare the prevalence of ABO-HDN in Asian, Black, Hispanic and Caucasian infants, we studied 10,611 consecutive births at one hospital over a 6-year period. Among group A infants born to group O mothers, the prevalence of positive DAT differed among the four groups (p = 0.007), and was highest in Asians (50%) and lowest in Caucasians (31%). However, the proportions of infants who required exchange transfusion were not different (p = 0.351). Among group B infants born to group O mothers, the prevalence of positive DAT was not different among the four groups (p = 0.26) and none of these 166 group B infants with a positive DAT result required exchange transfusion. Our findings suggest that there are small ethnic differences in the prevalence of positive DAT results in group A infants born to group O mothers, but the prevalence of clinical disease which requires exchange transfusion does not differ significantly among Asian, Black, Hispanic and Caucasian infants.

ABO Blood-Group System↗
PubMed1988

Evaluation of a third sequential tuberculin skin test in a chronic care population.

To evaluate factors that might influence the accuracy of tuberculin tests in identifying elderly persons recently infected with Mycobacterium tuberculosis, we performed as many as 3 sequential administrations of 5 tuberculin units of purified protein derivative in 1,726 persons residing in chronic care facilities. Significant reactions (greater than or equal to 10 mm of induration) to 1 of 3 tests were found in 702 (40.7%) persons. Of these, 68% were found with Test 1, 22.5% with Test 2, and 9.5% with Test 3. Of 1,146 persons with nonsignificant reactions to Test 1, 13.8% had significant reactions on Test 2, and of 769 persons with nonsignificant reactions to Tests 1 and 2, 8.7% had significant reactions on Test 3. Males, nonwhites, and persons between 50 and 79 yr of age had a greater proportion of significant reactions for each of the first 2 tests but not for the third test. These data indicate that continued boosting of the tuberculin reaction occurs in a substantial number of persons who receive a third sequential test. Marked increases in the size of reactions caused by boosting may explain high apparent conversion rates found in facilities where the third test is delayed for one year.

Adolescent↗
PubMed1988

Serological and immunochemical characteristics of Ge-negative red cells and anti-Ge.

Gerbich-negative red cells lack Beta and gamma sialoglycoproteins (SGPs), which are now known to carry the Gerbich (Ge) antigens. Gerbich and Yus-type Ge-negative red cells possess distinct diffuse SGPs that migrate on sodium dodecyl sulphate polyacrylamide gel electrophoresis in a position between those normally occupied by Beta and gamma SGPs. Both these SGPs lack tie2 antigens and possess epitopes recognized by monoclonal anti-Beta These SGPs differ from each other in at least two ways. The SGP associated with the Gerbich type also lacks the Ge3 antigen and is resistant to trypsin treatment. The SGP associated with the Yus type possesses the antigenic determinant recognized by anti-Ge3 and is sensitive to trypsin digestion.

Journal Article↗
PubMed1987

Structural relationships between human erythrocyte sialoglycoproteins beta and gamma and abnormal sialoglycoproteins found in certain rare human erythrocyte variants lacking the Gerbich blood-group antigen(s).

The human erythrocyte membrane sialoglycoproteins beta and gamma are important for the maintenance of the discoid shape of the normal erythrocyte. In this paper we show that the human erythrocyte sialoglycoproteins beta and gamma (hereafter called beta and gamma) are structurally related. Rabbit antisera produced against purified beta and beta 1 and rendered specific to the cytoplasmic portion of these proteins also react with the cytoplasmic portion of gamma. Some human anti-Gerbich (Ge) sera react with the extracellular portion of both beta and gamma. This reactivity is shown to be directed towards a common epitope on beta and gamma. However, most anti-Ge sera do not react with beta, but react with an extracellular epitope only present on gamma. All individuals who lack the Ge antigens lack beta and gamma. In some cases abnormal sialoglycoproteins are present in the erythrocytes, and these are shown to be structurally related to beta and gamma. Rabbit antisera raised against the purified abnormal sialoglycoprotein from a Ge-negative erythrocyte type reacted with the cytoplasmic portion of both beta and gamma. Unlike normal beta and gamma, the abnormal sialoglycoproteins found in Ge-negative erythrocytes migrate as a diffuse band on SDS/polyacrylamide-gel electrophoresis. Studies using endoglycosidases suggest that the diffuse nature of these bands results from carbohydrate heterogeneity and that the abnormal sialoglycoproteins contain N-glycosidically linked oligosaccharides with repeating lactosamine units. Such polylactosamine chains are not present on normal beta or gamma.

Blood Group Antigens↗
PubMed1987

Normal membrane function of abnormal beta-related erythrocyte sialoglycoproteins.

Red cells totally deficient in beta and gamma sialoglycoproteins (the Leach type of Gerbich-negative) are elliptocytic and have altered membrane physical properties as evidenced by marked decreases in both membrane mechanical stability and membrane deformability. Red cells from individuals who are of the Gerbich and Yus phenotypes of Gerbich-negative are also deficient in beta and gamma sialoglycoproteins, but possess abnormal beta-related sialoglycoproteins. In order to determine if these beta-related sialoglycoproteins can functionally substitute for normal sialoglycoproteins, we measured membrane deformability and stability of red cells of the Gerbich and Yus phenotypes. In contrast to the red cells of the Leach phenotype, cells of Gerbich and Yus phenotypes were found to have normal membrane deformability and stability. Moreover, flow cytometric analysis using a monoclonal anti-beta antibody revealed that the Gerbich and Yus phenotype red cells expressed the beta-related sialoglycoprotein to the same extent as its normal counterpart on normal cells. Based on these data, we suggest that the abnormal beta-related sialoglycoproteins can functionally substitute for normal beta and gamma sialoglycoproteins.

Erythrocyte Deformability↗
PubMed1987

Detection of the human erythrocyte surface antigen gerbich by flow cytometry using human antibodies and phycoerythrin for extreme immunofluorescence sensitivity.

We used indirect immunofluorescence and flow cytometry to detect the human erythrocyte surface antigen Gerbich. The procedure consisted of sequential erythrocyte-labeling with human antibody to Gerbich, biotinylated goat anti-human IgG and finally phycoerythrin-conjugated streptavidin. With maximal excitation of phycoerythrin at 546 nm, an increase in the fluorescence sensitivity was achieved. All erythrocytes from normal controls had detectable Gerbich antigen with little variation in antigen density between individuals. Six Gerbich-negative patients had no detectable antigen. By diluting the erythrocytes, as few as 0.1% antigen-positive cells in an antigen-negative population could be detected. These studies indicate that flow cytometry is a useful technique for the detection of erythrocyte surface antigens.

Antigens, Surface↗
PubMed1987

Inheritance of human-erythrocyte Gerbich blood group antigens.

The blood group-antigenic determinant Gerbich was first described greater than 25 years ago, but its mode of inheritance has not been established. We performed protein immunoblotting by means of anti-beta sialoglycoprotein (SGP) and anti-gamma SGP reagents. The anti-beta SGP was a monoclonal antibody that reacts with normal beta SGP and with the abnormal beta-related SGPs associated with Gerbich and Yus types of Ge-negative red cells. In the families studied, we have shown that the products of the Ge alleles are inherited in an autosomal codominant manner.

Alleles↗
PubMed1987

Identification of a functional role for human erythrocyte sialoglycoproteins beta and gamma.

Four distinct erythrocyte membrane sialoglycoproteins (SGPs) denoted alpha, beta, gamma, and delta have been described, but their functions have not yet been defined. Recent evidence suggests that several of these SGPs associate with membrane skeletal proteins. Because the membrane skeletal protein network plays an important role in regulating the membrane material properties of deformability and mechanical stability, we wanted to determine whether the SGPs, through their interaction with the membrane skeleton, can modulate these membrane properties. We measured membrane mechanical stability and membrane deformability of erythrocytes that were deficient in either alpha, or delta or beta and gamma SGPs. Only erythrocytes deficient in beta and gamma SGP had altered membrane properties, as evidenced by marked decreases in both membrane mechanical stability (50% of normal) and membrane deformability (40% of normal). Erythrocytes deficient in either alpha or delta SGP had normal deformability and stability. Based on these data, we suggest that an interaction of beta and/or gamma SGP with the membrane skeleton plays a functionally important role in regulating normal erythrocyte membrane properties.

Cytoskeletal Proteins↗
PubMed1986

A family demonstrating inheritance of the Leach phenotype: a Gerbich-negative phenotype associated with elliptocytosis.

The proposita of a Canadian family and 2 of her sibs have the rare Leach phenotype and provide the first evidence that the Leach phenotype is an inherited condition. Their red cells are Ge: -2, -3 and fail to react, by the antiglobulin test, with the monoclonal antibodies GERO, BRIC 4 and BRIC 10. The minor sialoglycoproteins beta, beta 1 and gamma are apparently absent from their red cell membranes. A proportion of their red cells are elliptocytes indicating that beta and/or beta 1 and/or gamma have a function in maintaining normal red cell shape.

Antibodies, Monoclonal↗
PubMed1985

Abnormal minor human erythrocyte membrane sialoglycoprotein (beta) in association with the rare blood-group antigen Webb (Wb).

Individuals whose erythrocytes are positive for the rare blood-group antigen Webb (Wb) have an altered form of the minor sialoglycoprotein beta (synonyms glycophorin C and glycoconnectin). This altered sialoglycoprotein beta (beta Wb) has an Mr about 2700 lower than that of normal sialoglycoprotein beta. Treatment of normal sialoglycoprotein beta with endo-beta-N-acetylglucosaminidase F decreased its Mr by about 3600, but similar treatment of sialoglycoprotein beta Wb had no effect. These results suggest the possibility that sialoglycoprotein beta Wb lacks the N-glycosidically linked oligosaccharide found on normal sialoglycoprotein beta.

Blood Group Antigens↗