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1

The levels of glycosphingolipids, ceramides, sialic acid and glycogen are changed in plasma membranes of rat platelets harvested during recovery from immune-mediated thrombocytopenia

100%

Zdebska E. , Soszynska B. , Dobrowolski Z. , Koscielak J.

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tom 43

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nr 3

EN

Plasma membranes of rat platelets produced at normal platelet counts and during early recovery from immune-mediated thrombocytopenia were examined for the contents of carbohydrates, lipids and glycosphingolipids. Glucosylceramide, two monosialo-gangliosides and one disialo-ganglioside were found to be the major glycosphingolipids of platelets. During thrombocytopenia the contents of these glycosphingolipids as well as of ceramides were several fold elevated. Among carbohydrate constituents of platelets and platelet plasma membranes, glycogen content was increased and that of sialic acid decreased. These results are discussed in the light of literature data on relevant biochemical characteristics of megakaryocytes at different stages of maturation and on thrombopoiesis during acute experimental thrombocytopenia.

2

In comparison to progenitor platelets, microparticles are deficient in GpIb, GpIb-derived carbohydrates, glycerophospholipids, glycosphingolipids, and ceramides

100%

Zdebska E. , Wozniak J. , Dzieciatkowska A. , Koscielak J.

Acta Biochimica Polonica

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1998

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tom 45

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nr 2

EN

Activated blood platelets shed microparticles with procoagulant activity that probably participate in normal hemostasis. We have isolated spontaneously formed microparticles from human blood and analysed them for ultrastructure, antigenic profile, and biochemical composition. In transmission electron microscopy microparticles appeared as regular vesicles with a mean diameter of 300 nm (50-600 nm). In flow cytometry almost all microparticles reacted with fluorescein isothiocyanate (FITC) labeled antibody to platelet glycoprotein complex IIb-IIIa (GpIIb-IIIa) and with FITC-annexin V but only 40-50% of microparticles reacted with FITC-antibody to platelet glycoprotein Ib (GpIb). The latter result was confirmed by double labeling of microparticles with FITC-antibody to GpIIb-IIIa and phycoerythrin (PE) labeled antibody to GpIb. Large microparticles reacted better with anti-GpIb than the small ones. A decreased level of GpIb was also demonstrated by SDS/polyacrylamide gel electrophoresis of microparticles. Compositional studies indicated, that in terms of cholesterol and protein contents, microparticles resembled platelets rather than platelet membranes as previously thought. They are, however, deficient in certain components. Thus, in comparison to platelets, microparticles had reduced contents of sialic acid (by 56.4%), galactosamine (by 48.2%), glucosamine (by 22.4%), galactose by (11.8%) and fucose (by 21.6%). Mannose content was increased by 11.8%. Total phospholipids in microplatelets were lower by 17.8%. Glycerophospholipids only were affected with phosphatidylserine being decreased as much as by 43.2%. Neutral glycosphingolipids, gangliosides and ceramides in microparticles were reduced by half. We conclude that the biochemical composition of microparticles probably reflects previous activation of progenitor platelets

3

Glycophorin A in two patients with congenital dyserythropoietic anemia type I and type II is partly unglycosylated

100%

Zdebska E. , Adamczyk-Poplawska M. , Koscielak J.

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2000

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tom 47

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nr 3

EN

Glycophorins A from erythrocyte membranes of two patients with congenital dyserythropoietic anemia type I and type II (CDA type I and II) were analyzed for carbohydrate molar composition employing a modification of the recently published method that allowed simultaneous determination of carbohydrates and protein in electrophoretic bands of glycoproteins separated by sodium dodecyl sulfate- polyacrylamide gel electrophoresis (Zdebska & Koscielak, 1999, Anal. Biochem., 275, 171-179). The modification involved a preliminary extraction of erythrocyte membranes with aqueous phenol, subsequent electrophoresis and analysis of the extracted glycophorins rather than electrophoresis and analysis of the glycophorin from intact erythrocyte membranes. The results showed a large deficit of N-acetylgalactosamine, galactose, and sialic acid residues in glycophorin A from patients with CDA type I and type II amounting to about 45% and 55 %, respectively. The results strongly suggest that glycophorin A in these patients is partly unglycosylated with respect to O-linked glycans. In addition, glycophorin A from erythrocytes of a patient with CDA II but not CDA I exhibited a significant deficit of mannose and N-acetylglucosamine suggesting that its N-glycosylation site was also partly unglycosylated.

4

Wrodzone niedokrwistości dyserytropoetyczne

100%

Zdebska E.

Diagnostyka Laboratoryjna

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2002

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tom 38

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nr 3

5

Quantitative analysis of LacCer-CDw17 in human myelogenous leukaemic cells

88%

Spychalska J. , Smolenska-Sym G. , Zdebska E. , Wozniak J. , Koscielak J.

Cellular and Molecular Biology Letters

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2003

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tom 08

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nr 4

EN

LacCer/CDw17 is the most abundant GSL in neutrophils. The cell-surface and intracellular presence of LacCer was determined quantitatively using anti-CDw17 mAbs in a flow cytometry assay. The quantified alterations in the level of CDw17 antigen expression are consistent with alterations in LacCer content, determined chemically. Our results show that CDw17 antigen expression defines successive stages in the maturation of the myeloid cell. The assessment of cell-surface and intracellular CDw17 expression may be useful in evaluating neutrophil physiological status.

6

Activity of platelet alpha-6-fucosyltransferase is inversely related to blood platelet concentration

88%

Koscielak J. , Antoniewicz-Papis J. , Zdebska E. , Maj S. , Leszko B.

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nr 1

EN

The activity of serum a-6-fucosyl transferase, a platelet derived enzyme, determined in sera of 22 normal individuals and 86 patients with various disorders was positively correlated with platelet counts. When the enzyme activity in 1 jil serum was calculated per 1000 of platelets in blood (coefficient F/P) an inverse correlation became evident in that F/P was proportionally the higher the lower was platelet count in blood. The F/P values were in a good agreement with the results of direct assays of enzyme activities in isolated platelets. Neither granulocytes, lymphocytes nor red cells significantly contributed to serum enzyme activity though granulocytes enhanced the thrombin-induced enzyme release from platelets. In platelets separated by centri- fugation in density gradients the enzyme was shown to be present in platelets of intermediate and high density but missing from the light ones. It is suggested that a-6-fucosyltransferase of platelets may be a marker of the ploidy level of megakaryocytes.

7

Molecular analysis of three novel G6PD variants: G6PD Pedoplis-Ckaro, G6PD Piotrkow and G6PD Krakow

63%

Maciag M. , Plochocka D. , Jablonska-Skwiecinska E. , Mendek-Czajkowska E. , Golaszewska E. , Strojny W. , Balwierz W. , Zdebska E. , Burzynska B.

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tom 54

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nr 4

877-881

EN

We present three novel mutations in the G6PD gene and discuss the changes they cause in the 3-dimensional structure of the enzyme: 573C→G substitution that predicts Phe to Leu at position 191 in the C-terminus of helix αe, 851T→C mutation which results in the substitution 284Val→Ala in the β+α domain close to the C-terminal part of helix αj, and 1175T→C substitution that predicts Ile to Thr change at position 392.

8

Contents of total and protein-bound carbohydrates are low in leukemic leucocytes from patients with acute myelogenous leukemia

63%

Smolenska-Sym G. , Zdebska E. , Golaszewska E. , Wozniak J. , Durzynski T. , Maj S. , Mokras U. , Koscielak J.

Acta Biochimica Polonica

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1998

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tom 45

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nr 2

EN

Leukemic leukocytes from 12 patients with acute myelogenous leukemia (AML) and two patients with chronic myelogenous leukemia (CML) were isolated by centrifugations in Percoll gradients, and examined for total carbohydrates. In leukemic leukocytes from 10 of these patients ceramide-bound carbohydrates were also determined. Protein-bound carbohydrates were calculated by subtraction of ceramide-bound carbohydrates from total carbohydrates. In all samples analysed the contents of total and protein-bound carbohydrates were much lower in leukemic leukocytes than in normal neutrophils, irrespective whether the results were expressed relative to protein, DNA, cell number or dry mass. For immature leukemic cells of MO-M1 phenotype differences up to 10-fold were observed. Contents of ceramide-bound carbohydrates, i.e. those of neutral and acidic glycosphingolipids (GSLs) were also low in leukemic cells. However, when GSL carbohydrates were calculated as percentage of total carbohydrates, GSLs in leukemic leukocytes were elevated in half of the AML patients but depressed in the other half. The results are discussed in the light of the hypothesis on GSL function by one of us (Kościelak J., 1986, Glycoconjugate J. 3, 95-108). According to one element of the hypothesis, during cell differentiation newly synthesized glycoproteins (GPs) that perform specific functions are added to house-keeping GPs that are present in plasma membranes of all types of cells. Thus, during differentiation, the GP content of the cell membrane should increase and that of the so called "membrane packing" glycosphingolipids should decrease.