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Biomedical subjects

R Oriol

Publications and source records attributed to R Oriol.

At least 127 records · Page 7Linked to original sources
PubMed1988

Expression of ABH and X (Lex) antigens in various cells.

Using a panel of reagents specific to the various subtypes of ABH antigens, it could be demonstrated that platelets carry ABH type 2 monofucosylated determinants on intrinsic glycoproteins. The presence of these antigens is controlled by the H gene and correlates with the presence of alpha-2-L-fucosyltransferase and the absence of alpha-3-L-fucosyltransferase. In contrast, intrinsic ABH antigens were not found on mononuclear cells, correlating with the absence of alpha-2-L-fucosyltransferase on these cells. However, after transformation with the Epstein-Barr virus and stimulation with 12-O-tetradecanoylphorbol-13-O-acetate (TPA), B lymphocytes were found to express the H antigen under control of the H gene and not the Se gene. The lymphoblastoid cell lines also expressed the X and sialylated X antigens which are normally markers of the myeloid lineage. These antigens are also normally found in epithelial cells of the digestive tract, kidney proximal convoluted tubules and hepatocytes. The alpha-3-L-fucosyltransferase responsible for the synthesis of this antigen is present in the serum but we report the existence of two individuals, a mother and her daughter, who lack more than 90% of this serum enzyme. The young girl suffers from a congenital kidney anomaly: oligomeganephronic hypoplasia. Her kidney tubules are devoid of X antigen. However, she and her mother have the X antigen on their granulocytes and its sialylated form on their monocytes. It therefore appears that there are distinct genetic controls for the expression of antigen X in different body compartments. This would be quite similar to the H and Se gene controls in tissues of distinct embryological origins.

ABO Blood-Group System↗
PubMed1988

Use of a simple method for the Epstein-Barr virus transformation of lymphocytes from members of large families of Réunion Island.

A simple method for the preparation of lymphoblastoid cell lines from small amounts (100 microliter) of frozen whole blood is described. A success score greater than 90% was obtained for EBV transformations using blood samples which had been collected several months before the infection. Due to the simplicity of the technique, up to 80 samples could be processed per day. This technique was used to prepared 242 permanent cell lines from 13 large families from Réunion Island showing blood group H deficiency. These cell lines are now available for genetic studies.

ABO Blood-Group System↗
PubMed1988

Failure of expression of alpha-3-L-fucosyltransferase in human serum is coincident with the absence of the X (or Le(x)) antigen in the kidney but not on leucocytes.

The X antigen, beta Gal(1----4)[alpha Fuc(1----3)]beta GlcNAc-R, is mostly found in epithelial cells of the digestive tract, proximal convoluted tubules of the kidney, and granulocytes. The alpha-3-L-fucosyltransferase responsible for synthesis of this antigen is normally present in the serum, but we found 2 individuals, a mother and her daughter, who lack more than 90% of the serum fucosyltransferase. They are of African origin and are both Le(a-b-). The young girl suffers from a congenital kidney anomaly: oligomeganephronic hypoplasia. Her kidney tubules are devoid of X antigen. However, her mother and herself normally possess the X antigen on granulocytes and its sialylated form on monocytes. Anephric patients showed reduced serum alpha-3-L-fucosyltransferase activity, suggesting that the kidney contributes to an important fraction of serum enzymic activity. It, therefore, appears that there are distinct genetic controls governing expression of the X antigen in different body compartments. Possibly, different alpha-3-L-fucosyltransferases could be at work in kidney and leucocytes.

ABO Blood-Group System↗
PubMed1988

Cardiac allotransplantation across major blood group barriers in the baboon.

In heterotopic heart transplantation experiments in Chacma baboons, some of the animals were significantly immunosuppressed with cyclosporine, resulting in prolonged cardiac allograft survival. ABO blood group incompatibility between recipient and donor did not significantly influence mean allograft survival, but early hyperacute (vascular) or acute (cellular) rejection occurred only when ABO incompatibility was present.

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PubMed1988

The jelly layers and cortex of the unfertilized Xenopus laevis egg: carbohydrate, phospholipid and protein analysis.

Differences in the carbohydrate composition were found in the jellies and the cortex of the unfertilized Xenopus laevis egg using lectins and blood group antibodies. Blood group H trisaccharide was detected in the outer jelly and "A-like" oligosaccharide was found in the inner jelly. The blood group A trisaccharide was detected in the vitelline envelope and the cortex. The plasma membranes were isolated and partially purified by differential centrifugation on sucrose cushion. The phospholipid composition of the membrane was assessed by quantitative two-dimensional thin layer chromatography. The major phospholipids were sphingomyelin (8%), phosphatidylcholine (55%), phosphatidylinositol and phosphatidylserine (7%), and phosphatidylethanolamine (26%). The external application of phospholipase A2 indicated a possible asymmetry of the phospholipids in the membrane such as the acidic phospholipids are preferentially located at the inner leaflet. The membrane protein and glycoprotein pattern was examined by gel electrophoresis using Triton and selective staining. Six major glycoproteins ranging from 250 to 32 kDa, were detected among the Triton-insoluble components.

Animals↗
PubMed1988

Expression of ABH and X (Lex) antigens on platelets and lymphocytes.

We used a panel of reagents, polyclonal and monoclonal antibodies, and lectins to define the expression of the ABH- and Lewis-related specificities on platelets and lymphocytes. We also determined the expression of the alpha 2- and alpha 3-L-fucosyltransferases necessary for their biosynthesis. The antigens that could be detected by immunofluorescence and Western blot analysis were based on type 2 monofucosylated structures. Antibodies directed toward types 1, 3, and 4 ABH-, X- and Lewis-related antigenic determinants were always negative because the small amounts of ABH and Lewis antigens adsorbed from the serum could not be detected by these techniques. The presence of the type 2 ABH antigens on intrinsic glycoproteins was controlled by the H gene. This correlates with the presence of alpha 2-L-fucosyltransferase and the absence of alpha 3-L-fucosyltransferase on platelets. In contrast, ABH antigens were not detected by immunofluorescence on normal peripheral lymphocytes. These cells thus have only the small amounts of antigens adsorbed from the serum, these being under control of the secretor and Lewis genes. This correlates with the absence of alpha 2-L-fucosyltransferase on lymphocytes. When lymphocytes were transformed in vitro by the Epstein-Barr virus (EBV), however, they strongly expressed the X and sialylated X antigens, which are specific markers of normal granulocytes and monocytes, respectively. Treatment of EBV-transformed lymphoblastoid cell lines with 12-O-tetradecanoylphorbol-13-O-acetate significantly decreased the expression of X and sialylated X antigens along with that of surface immunoglobulins, whereas it induced a significant expression of the H antigen under control of the H gene.

ABO Blood-Group System↗
PubMed1987

Heterogeneity of anti-A and anti-B monoclonal reagents. Agglutination of some weak ABH erythrocyte variants and recognition of synthetic oligosaccharide and tissue antigens.

Eight anti-A and seven anti-B monoclonal reagents were tested in parallel, with normal and weak ABH red cell phenotypes. A whole range of different reactivity patterns was found, but by making a comparison with the results obtained using polyclonal standard reagents, two major categories of reagents were distinguished: (a) stronger and more specific reagents, and (b) reagents similar to, or weaker than, the standard polyclonal controls. The analysis of the specificity of the reagents by tissue fluorescence staining and reactivity with synthetic oligosaccharides and purified glycolipids confirmed the existence of broad and restricted specificities. Two kinds of anti-A1 reagents are described. One related to type 3/4 structures, which stains the Golgi apparatus, and another with broad anti-A specificity which cross-reacts with 'A-like' structures. The inhibition of anti-A reagents with salivas and synthetic oligosaccharide antigens gave parallel results for the secretor salivas and the difucosylated A antigens.

ABO Blood-Group System↗
PubMed1987

Localization of H blood group antigen in ectoblastic derivatives of murine teratocarcinoma.

Ectoblastic derivatives (ectodermal and neuroectodermal components) constitute more than 90% of all structures in the murine teratocarcinoma derived from the PCC4-aza-1 line. This tumor was labeled immunocytochemically with fluoresceinated antibodies to A, B and H blood groups. A and B antigens were always noted to be absent from all structures of the three germ layers. With anti-H, however, embryonic and fetal endodermal components, e.g. alimentary or respiratory duct-like structures, gave positive staining. Mesodermal components, i.e. bone and cartilage structures, fibroblasts and myocytes of mature or embryonal type, were negative. Immature and mature ectodermal components, viz. epidermoid cysts or islets, were always positive. Neuroectodermal components, neuroblastic cysts and differentiated neuronal, glial and ependymal elements were always negative. Ectoblastic and/or neuroectoblastic individual cells or cell clusters, observed in the vicinity of positive differentiating ectodermal and neuroectodermal structures, were positive. Similar cells or clusters were negative when located close to negative neuroectodermal components. The undifferentiated, embryonal carcinoma cells and structures were always negative. These observations are compared to the staining patterns of H antigen in murine embryos and adult mice and in human teratocarcinomas. It is suggested that poorly differentiated, morphologically similar ectoblastic and/or neuroectoblastic structures are positive, if they concern ectodermal components, and negative, if they belong to neuroectodermal components, with the exception of some primary sensory cells that are positive. These last cells are also positive in normal fetal and adult tissues.

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