Informacja

Drogi użytkowniku, aplikacja do prawidłowego działania wymaga obsługi JavaScript. Proszę włącz obsługę JavaScript w Twojej przeglądarce.

English (EN)·Polski (PL)·Yкраїнський (UK)
Przejdź do strony domowej biblioteki Centralna Biblioteka Wojskowa Link otwiera się w nowym oknie Logo biblioteki Prolib Integro - strona głównaCentralna Biblioteka Wojskowa

Wyszukujesz frazę "platelets" wg kryterium: Temat

  Lista filtrów
Wyrównaj
    Wyświetlanie 1-10 z 10
    Tytuł:
    A biochemical study on the level of lipids and glycoproteins in the serum and platelets of liver cirrhotic bleeders
    Autorzy:
    Vijayalakshmi, Sivagurunathan
    Geetha, Arumugam
    Jeyachristy, Sam
    Powiązania:
    https://bibliotekanauki.pl/articles/1041294.pdf
    Data publikacji:
    2006
    Wydawca:
    Polskie Towarzystwo Biochemiczne
    Tematy:
    glycoproteins
    lipids
    cirrhosis
    adenosine triphosphatases
    platelets
    Opis:
    Bleeding complication and abnormal platelet functions are associated with liver cirrhosis. The aim of the present investigation was to assess the functional integrity of platelets in terms of lipids like cholesterol and phospholipids, glycoproteins and membrane-bound enzymes. Liver cirrhotic patients with bleeding complications were studied. Age and sex matched normal healthy volunteers were also involved in this study as a control group. Levels of cholesterol, phospholipids, glycoproteins and adenosine triphosphatases were assessed in isolated platelet membrane fraction. The level of glycoproteins and the activity of adenosine triphosphatases were found to be decreased significantly in cirrhotic patients. The cholesterol/phospholipid ratio was found to be altered significantly, indicating an alteration in the fluidity of platelet membrane. The results of this study reveal that the functional impairment of platelets in liver cirrhotic patients which is responsible for their bleeding tendency might also be due to altered lipid and enzyme levels in platelet membrane.
    Źródło:
    Acta Biochimica Polonica; 2006, 53, 1; 213-220
    0001-527X
    Pojawia się w:
    Acta Biochimica Polonica
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Involvement of Na+/H+ exchanger in desmopressin-induced platelet procoagulant response.
    Autorzy:
    Tomasiak, Maria
    Stelmach, Halina
    Bodzenta-Łukaszyk, Anna
    Tomasiak, Marian
    Powiązania:
    https://bibliotekanauki.pl/articles/1041558.pdf
    Data publikacji:
    2004
    Wydawca:
    Polskie Towarzystwo Biochemiczne
    Tematy:
    Na+/H+ exchanger
    platelets
    desmopressin
    procoagulant activity
    Opis:
    Desmopressin (DDAVP) action on platelets is associated with the development of procoagulant response but the underlying mechanism of this phenomenon is not known. We investigated whether this effect of DDAVP might be due to activation of plasma membrane Na+/H+ exchanger. The DDAVP-induced platelet procoagulant response, measured as phospholipid-dependent thrombin generation, was dose dependent and significantly weaker than that produced by collagen or monensin (mimics Na+/H+ antiport). Both the DDAVP- and collagen-produced procoagulant responses were less pronounced in the presence of EIPA, an Na+/H+ exchanger inhibitor. Flow cytometry studies revealed that in vitro treatment of platelets with DDAVP or collagen was associated with the appearance of both degranulated (and fragmented) and swollen cells. The DDAVP-evoked rise in size and granularity heterogeneity was similar to that produced by collagen or monensin and was not observed in the presence of EIPA. Using flow cytometry and annexin V-FITC as a probe for phosphatidylserine (PS) we demonstrated increased and uniform binding of this marker to all subsets of DDAVP-treated platelet population. The DDAVP-evoked PS expression was dose dependent, strongly reduced by EIPA and weaker than that caused by monensin or collagen. As judged by optical swelling assay, DDAVP in a dose dependent manner produced a rise in platelet volume. The swelling was inhibited by EIPA and its kinetics was similar to that observed in the presence of monensin. Electronic cell-sizing measurements showed an increase in mean platelet volume and a decrease in platelet count and platelet crit upon treatment with DDAVP. DDAVP elicited a slow (much slower than collagen) alkalinization of platelet cytosol. Altogether the data indicate an involvement of Na+/H+ exchanger in the generation of procoagulant activity in DDAVP-treated platelets.
    Źródło:
    Acta Biochimica Polonica; 2004, 51, 3; 773-788
    0001-527X
    Pojawia się w:
    Acta Biochimica Polonica
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Peroxynitrite can affect platelet responses by inhibiting energy production
    Autorzy:
    Rusak, Tomasz
    Tomasiak, Marian
    Ciborowski, Michal
    Powiązania:
    https://bibliotekanauki.pl/articles/1041172.pdf
    Data publikacji:
    2006
    Wydawca:
    Polskie Towarzystwo Biochemiczne
    Tematy:
    aggregation
    porcine platelets
    peroxynitrite
    mitochondria
    glycolysis
    secretion
    Opis:
    Peroxynitrite (ONOO-) strongly inhibits agonist-induced platelet responses. However, the mechanisms involved are not completely defined. Using porcine platelets, we tested the hypothesis that ONOO- reduces platelet aggregation and dense granule secretion by inhibiting energy production. It was found that ONOO- (25-300 µM) inhibited collagen-induced dense granule secretion (IC50 = 55 ± 7 µM) more strongly than aggregation (IC50 = 124 ± 16 µM). The antiaggregatory and antisecretory effects of ONOO- were only slightly (5-10%) reduced by 1H-[1,2,4]-oxadiazolo-[4,3-α]quinoxalin-1-one (ODQ), an inhibitor of soluble guanylate cyclase. In resting platelets ONOO- (50-300 µM) enhanced glycolysis rate and reduced oxygen consumption, in a dose dependent manner. The ONOO- effects on glycolysis rate and oxygen consumption were not abolished by ODQ. The extent of glycolysis stimulation exerted by ONOO- was similar to that produced by respiratory chain inhibitors (cyanide and antimycin A) or an uncoupler (2,4-dinitrophenol). Stimulation of platelets by collagen was associated with a rise in mitochondrial oxygen consumption, accelerated lactate production, and unchanged intracellular ATP content. In contrast to resting cells, in collagen-stimulated platelets, ONOO- (200 µM) distinctly decreased the cellular ATP content. The glycolytic activity and oxygen consumption of resting platelets were not affected by 8-bromoguanosine 3',5'-cyclic monophosphate. Blocking of the mitochondrial ATP production by antimycin A slightly reduced collagen-induced aggregation and strongly inhibited dense granule secretion. Treatment of platelets with ONOO- (50-300 µM) resulted in decreased activities of NADH : ubiquinone oxidoreductase, succinate dehydrogenase and cytochrome oxidase. It is concluded that the inhibitory effect of ONOO- on platelet secretion and to a lesser extent on aggregation may be mediated, at least in part, by the reduction of mitochondrial energy production.
    Źródło:
    Acta Biochimica Polonica; 2006, 53, 4; 769-776
    0001-527X
    Pojawia się w:
    Acta Biochimica Polonica
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Nitric oxide and platelet energy metabolism.
    Autorzy:
    Tomasiak, Marian
    Stelmach, Halina
    Rusak, Tomasz
    Wysocka, Jolanta
    Powiązania:
    https://bibliotekanauki.pl/articles/1041559.pdf
    Data publikacji:
    2004
    Wydawca:
    Polskie Towarzystwo Biochemiczne
    Tematy:
    mitochondrial energy production
    porcine platelets
    nitric oxide
    glycolysis
    Opis:
    This study was undertaken to determine whether nitric oxide (NO) can affect platelet responses through the inhibition of energy production. It was found that NO donors: S-nitroso-N-acetylpenicyllamine, SNAP, (5-50 μM) and sodium nitroprusside, SNP, (5-100 μM) inhibited collagen- and ADP-induced aggregation of porcine platelets. The corresponding IC50 values for SNAP and SNP varied from 5 to 30 μM and from 9 to 75 μM, respectively. Collagen- and thrombin-induced platelet secretion was inhibited by SNAP (IC50 = 50 μM) and by SNP (IC50 = 100 μM). SNAP (20-100 μM), SNP (10-200 μM) and collagen (20 μg/ml) stimulated glycolysis in intact platelets. The degree of glycolysis stimulation exerted by NO donors was similar to that produced by respiratory chain inhibitors (cyanide and antimycin A) or uncouplers (2,4-dinitrophenol). Neither the NO donors nor the respiratory chain blockers affected glycolysis in platelet homogenate. SNAP (20-100 μM) and SNP (50-200 μM) inhibited oxygen consumption by platelets. The effect of SNP and SNAP on glycolysis and respiration was not reduced by 1H-[1,2,4]oxadiazolo-[4,3-a]quinoxalin-1-one, a selective inhibitor of NO-stimulated guanylate cyclase. SNAP (5-100 μM) and SNP (10-300 μM) inhibited the activity of platelet cytochrome oxidase and had no effect on NADH:ubiquinone oxidoreductase and succinate dehydrogenase. Blocking of the mitochondrial energy production by antimycin A slightly affected collagen-evoked aggregation and strongly inhibited platelet secretion. The results indicate that: 1) in porcine platelets NO is able to diminish mitochondrial energy production through the inhibition of cytochrome oxidase, 2) the inhibitory effect of NO on platelet secretion (but not aggregation) can be attributed to the reduction of mitochondrial energy production.
    Źródło:
    Acta Biochimica Polonica; 2004, 51, 3; 789-803
    0001-527X
    Pojawia się w:
    Acta Biochimica Polonica
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    The mutual cooperation of blood platelets and lymphocytes in the development of autoimmune thyroid diseases
    Autorzy:
    Tomczyńska, Małgorzata
    Saluk-Bijak, Joanna
    Powiązania:
    https://bibliotekanauki.pl/articles/1038518.pdf
    Data publikacji:
    2018
    Wydawca:
    Polskie Towarzystwo Biochemiczne
    Tematy:
    autoimmune thyroid diseases
    autoantibodies
    blood platelets
    chronic inflammation
    lymphocytes
    Opis:
    Autoimmune thyroid diseases include several distinct clinical entities, mainly Graves' disease and Hashimoto's thyroiditis. An incompetent immune response directed against the body's own tissues, and the production of antibodies against specific cell antigens accompanied by chronic inflammation, all occur in autoimmune thyroid diseases. The autoimmune process is induced by genetic and environmental factors that are difficult to identify and generates the development of concomitant diseases in other systems. Leukocyte activation and overproduction of inflammatory mediators, as well as improper levels of thyroid hormones, play an essential role in the chronic course of these diseases. The development of autoimmune thyroid diseases results from the impairment of the regulatory and suppressor functions of T-cells or NK cells and activation of B cells, or from the changes in the number of those cells. Many reports have shown the significant role of platelet-leukocyte interaction in inflammation. Autoantibodies react with target antigens in different kinds of cells, including blood platelets, and autoimmune processes can modulate the mutual cooperation of blood platelets and lymphocytes. The activity of blood platelets and lymphocytes is reciprocally regulated. It has been suggested that blood platelets can influence lymphocyte function by direct contact with receptors, and indirectly via soluble mediators. The interactions of platelet-immune cells (neutrophils, monocytes, lymphocyte and dendritic cells) can have a potent enhancing effect on immune cells functions.
    Źródło:
    Acta Biochimica Polonica; 2018, 65, 1; 17-24
    0001-527X
    Pojawia się w:
    Acta Biochimica Polonica
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    The disturbance of hemostasis induced by hyperhomocysteinemia; the role of antioxidants
    Autorzy:
    Malinowska, Joanna
    Kolodziejczyk, Joanna
    Olas, Beata
    Powiązania:
    https://bibliotekanauki.pl/articles/1039731.pdf
    Data publikacji:
    2012
    Wydawca:
    Polskie Towarzystwo Biochemiczne
    Tematy:
    homocysteine thiolactone
    blood platelets
    fibrinogen
    hemostasis
    hyperhomocysteinemia
    antioxidant
    homocysteine
    plasminogen
    Opis:
    Elevated concentration of homocysteine (Hcy) in human tissues, definied as hyperhomocysteinemia has been correlated with some diseases, such as cardiovascular, neurodegenerative, and kidney disorders. Homocysteine occurs in human blood plasma in several forms, including the most reactive one, the homocysteine thiolactone (HTL) - a cyclic thioester, which represents up to 0.29% of total plasma Hcy. In the article, the effects of hyperhomocysteinemia on the complex process of hemostasis, which regulates the flowing properties of blood, are described. Possible interactions of homocysteine and its different derivatives, including homocysteine thiolactone, with the major components of hemostasis such as endothelial cells, blood platelets, plasmatic fibrinogen and plasminogen, are also discussed. Modifications of hemostatic proteins (N-homocysteinylation or S-homocysteinylation) induced by Hcy or its thiolactone seem to be the main cause of homocysteine biotoxicity in hemostatic abnormalities. It is suggested that Hcy and HTL may also act as oxidants, but various polyphenolic antioxidants are able to inhibit the oxidative damage induced by Hcy or HTL. We also discuss the role of phenolic antioxidants in hyperhomocysteinemia -induced changes in hemostasis.
    Źródło:
    Acta Biochimica Polonica; 2012, 59, 2; 185-194
    0001-527X
    Pojawia się w:
    Acta Biochimica Polonica
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Fluorometric assay of oleate-activated phospholipase D isoenzyme in membranes of rat nervous tissue and human platelets
    Autorzy:
    Krzystanek, Marek
    Trzeciak, Henryk
    Krzystanek, Ewa
    Małecki, Andrzej
    Powiązania:
    https://bibliotekanauki.pl/articles/1040386.pdf
    Data publikacji:
    2010
    Wydawca:
    Polskie Towarzystwo Biochemiczne
    Tematy:
    human platelets
    membranes
    rat brain
    fluorometric assay
    phospholipase D
    astrocytes
    Opis:
    Phospholipase D plays a key role in the biosynthesis of phosphatidic acid, a second messenger involved in essential cellular processes. Oleate-activated phospholipase D was the first mammalian phospholipase D isoform to be discovered but is the least known. The study was aimed to test a fluorometric method of assessment of oleate-activated phospholipase D activity in different biological materials. The brain cortex of male Wistar rats, cultured rat brain astrocytes, and human platelets were processed to yield plasmatic membranes for experiments. To assess phospholipase D activity the modified fluorometric method was used. Previously, the method was used only to determine H2O2. In this enzyme-coupled assay phospholipase D activity is monitored indirectly using 10-acetyl-3,7-dihydroxyphenoxazine. First, phospholipase D cleaves exogenous phosphatidylcholine to yield choline and phosphatidic acid. Second, choline is oxidized by choline oxidase to betaine and H2O2. Finally, in the presence of horseradish peroxidase, H2O2 reacts with 10-acetyl-3,7-dihydroxyphenoxazine to generate the highly fluorescent product, resorufin. The concentration of resorufin was measured using excitation and emission at 560 nm and 590 nm, respectively. The proposed optimal parameters of the tested assay are 25 µg of rat brain cortex protein, 50 µg of rat brain astrocyte protein, and 50 µg of human platelet protein in a reaction volume of 200 µL, and 2 min enzymatic reaction at 37°C. The fluorometric method may be applied to assay phospholipase D in different biological materials.
    Źródło:
    Acta Biochimica Polonica; 2010, 57, 3; 369-372
    0001-527X
    Pojawia się w:
    Acta Biochimica Polonica
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    The role of Na+/H+ exchanger in serotonin secretion from porcine blood platelets
    Autorzy:
    Tomasiak, Marian
    Ciborowski, Michal
    Stelmach, Halina
    Powiązania:
    https://bibliotekanauki.pl/articles/1041323.pdf
    Data publikacji:
    2005
    Wydawca:
    Polskie Towarzystwo Biochemiczne
    Tematy:
    platelet swelling
    platelet secretion
    serotonin release
    Na+/H+ exchanger
    platelets
    Opis:
    This study was undertaken to evaluate whether a link exists between the activation of protein kinase C (PKC), operation of Na+/H+ exchanger (NHE), cell swelling and serotonin (5-HT) secretion in porcine platelets. Activation of platelets by thrombin or phorbol 12-myristate 13-acetate (PMA), a PKC activator, initiated a rapid rise in the activity of Na+/H+ exchanger and secretion of 5-HT. Both thrombin- and PMA-evoked activation of Na+/H+ exchanger was less pronounced in the presence of ethyl-isopropyl-amiloride (EIPA), an NHE inhibitor, and by GF 109203X, a PKC inhibitor. Monensin (simulating the action of NHE) caused a dose-dependent release of 5-HT that was not abolished by GF 109203X or EGTA. Lack of Na+ in the suspending medium reduced thrombin-, PMA-, and monensin-evoked 5-HT secretion. GF 109203X nearly completely inhibited 5-HT release induced by PMA-, partly that induced by thrombin, and had no effect on 5-HT release induced by monensin. EIPA partly inhibited 5-HT release induced by thrombin and nearly totally that evoked by PMA. Electronic cell sizing measurements showed an increase in mean platelet volume upon treatment of cells with monensin, PMA or thrombin. The PMA- and thrombin-evoked rise in mean platelet volume was strongly reduced in the presence of EIPA. As judged by optical swelling assay monensin and PMA produced a rapid rise in platelet volume. The swelling elicited by PMA was inhibited by EIPA and its kinetics was similar to that observed in the presence of monensin. Hypoosmotically evoked platelet swelling did not affect platelet aggregation but significantly potentiated thrombin-evoked release of 5-HT and ATP. Taken together, these results show that in porcine platelets PKC may promote 5-HT secretion through the activation of NHE. It is hypothesized that enhanced Na+/H+ antiport may result in a rise in cell membrane tension (due to cell swelling) which in turn facilitates fusion of secretory granules with the plasma membrane leading to 5-HT secretion.
    Źródło:
    Acta Biochimica Polonica; 2005, 52, 4; 811-822
    0001-527X
    Pojawia się w:
    Acta Biochimica Polonica
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    The involvement of Na+/K+-ATPase in the development of platelet procoagulant response
    Autorzy:
    Tomasiak, Marian
    Stelmach, Halina
    Rusak, Tomasz
    Ciborowski, Michał
    Radziwon, Piotr
    Powiązania:
    https://bibliotekanauki.pl/articles/1041052.pdf
    Data publikacji:
    2007
    Wydawca:
    Polskie Towarzystwo Biochemiczne
    Tematy:
    cardiac glycosides
    ouabain
    Na+/K+-ATPase
    atrial fibrillation
    platelets
    procoagulant activity
    Opis:
    In circulation, platelets may come into contact with both exogenous (cardiac glycoside treatment) and endogenously produced inhibitors of Na+/K+-ATPase. We examined whether blocking of platelet Na+/K+-ATPase by ouabain results in generation of procoagulant activity. It was shown that an in vitro treatment of platelets with ouabain (20-200 µM for 20 to 60 min) is associated with an intracellular accumulation of sodium ([Na+]i), generation of a weak calcium signal, and expression of procoagulant activity. The ouabain-induced procoagulant response was dose- and time-related, less pronounced than that evoked by collagen and similar to that produced by gramicidin, not affected by EDTA or aspirin, and strongly reduced in the absence of extracellular Na+ or by hyperosmolality. Flow cytometry studies revealed that ouabain treatment results in a unimodal left shift in the forward and side scatter of the entire platelet population indicating morphological changes of the plasma membrane. The shift was dose related, weaker than that evoked by collagen and similar to that produced by gramicidin. Ouabain-treated platelets express phosphatidylserine (PS). The ouabain-evoked PS expression was dose- and time-dependent, weaker than that produced by collagen and similar to that evoked by gramicidin. Electronic cell sizing measurements showed a dose-dependent increase in mean platelet volume upon treatment with ouabain. Hypoosmotically-evoked platelet swelling resulted in the appearance of procoagulant activity. Thromboelastography measurements indicate that, in whole blood, nanomolar (50-1000 nM, 15 min) concentrations of ouabain significantly accelerate the rate of clot formation initiated by contact and high extracellular concentration of calcium. We conclude that inefficiently operating platelet Na+/K+-ATPase results in a rise in [Na+]i. An increase in [Na+]i and the swelling associated with it may produce PS exposure and a rise in membrane curvature leading to the generation of a procoagulant activity.
    Źródło:
    Acta Biochimica Polonica; 2007, 54, 3; 625-639
    0001-527X
    Pojawia się w:
    Acta Biochimica Polonica
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Allelic polymorphism of endothelial NO-synthase gene and its functional manifestations
    Autorzy:
    Dosenko, Victor
    Zagoriy, Vyacheslav
    Haytovich, Nikolay
    Gordok, Olga
    Moibenko, Alexey
    Powiązania:
    https://bibliotekanauki.pl/articles/1041240.pdf
    Data publikacji:
    2006
    Wydawca:
    Polskie Towarzystwo Biochemiczne
    Tematy:
    activity of nitric oxide synthase
    endothelial nitric oxide synthase
    RNA expression
    platelets
    allelic polymorphism
    Opis:
    Investigation of the mechanisms of phenotypic realization of allelic polymorphism of the eNOS gene has shown that the level of eNOS mRNA and activity of this enzyme in platelets depends from genotype. We identified a T-786→C polymorphism in the promoter region, a variable number of tandem repeats (4a/4b) in intron 4 and the G894→T polymorphism in exon 7 of the eNOS gene in isolated human platelets. We measured eNOS mRNA in isolated platelets by reverse transcription-PCR and eNOS enzyme activity by fluorimetric detection system FCANOS-1 using diaminofluorescein diacetate (DAF-2A). It was shown that the level of eNOS mRNA is the lowest for the -786C/C promoter genotype. In exon 7 homozygotes (894T/T) the level of RNA is lower than in normal homozygotes (894G/G), but higher than in heterozygotes (894G/T). The eNOS activity in platelets is lower in carriers of the 786C/C promoter genotype than in normal homozygotes (2.1 × P=0.03), and lower comparing to heterozygotes (2.9 × P>0.05). The eNOS activity accompanying the 894T/T variant of exon 7 is also lower than in normal homozygotes (P>0.05). Regarding the polymorphism in intron 4 - the enzyme's activity is lower in carriers of the 4a/4a genotype comparing to normal homozygotes (1.7 × P>0.05) and lower than in heterozygotes (1.9 × P>0.05). These results allow one to conclude that the T-786→C polymorphism of the eNOS gene promoter most significantly affects the gene expression and eNOS activity.
    Źródło:
    Acta Biochimica Polonica; 2006, 53, 2; 299-302
    0001-527X
    Pojawia się w:
    Acta Biochimica Polonica
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
      Wyświetlanie 1-10 z 10

      Ta witryna wykorzystuje pliki cookies do przechowywania informacji na Twoim komputerze. Pliki cookies stosujemy w celu świadczenia usług na najwyższym poziomie, w tym w sposób dostosowany do indywidualnych potrzeb. Korzystanie z witryny bez zmiany ustawień dotyczących cookies oznacza, że będą one zamieszczane w Twoim komputerze. W każdym momencie możesz dokonać zmiany ustawień dotyczących cookies