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 1-15 z 26
Tytuł:
Blood platelets apoptosis in hemodialyzed patients
Autorzy:
Sobol, A.
Kamińska, M.
Walczyńska, M.
Stasiak, M.
Szymański, J.
Walkowiak, M.
Walkowiak, B.
Powiązania:
https://bibliotekanauki.pl/articles/284932.pdf
Data publikacji:
2009
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Polskie Towarzystwo Biominerałów
Tematy:
blood platelets
hemodialysis
apoptosis
Opis:
Blood platelet proteome of hemodialyzed uremic patients exhibits significant difference in comparison to the blood platelet proteome of healthy subjects. This alteration is manifested by the presence of high concentrations of low molecular peptides within the whole range of pI. Increased platelet apoptosis has been put forward as a possible cause of this phenomenon (1). The aim of the present research was to assess whether blood platelet populations from hemodialyzed uremic patients exhibit more binding sites for Annexin V (a marker of apoptosis) than control samples from healthy donors. Blood was obtained from uremic patients immediately before and after hemodialysis. At the same time samples from control healthy donors were also collected. Blood was anticoagulated with sodium citrate and was immediately exposed to propidium iodide, fluorescent labeled Annexin V and CD61 antibodies. The samples were incubated for 10 minutes in the dark and next the labeled samples were processed in a BectonDickinson FACScan flow cytofluorymeter. Our preliminary study was performed for 12 hemodialyzed patients, 13nondialyzed uremic patientsand 12 controls. It was found that the blood platelet population of hemodialyzed patients exhibited significantly higher level of fluorescence intensity attributed to Annexin V. Furthermore, this intensity was comparable before and after hemodialysis and was independent on patient age. The results support the hypothesis that blood platelet contact with artificial surfaces during the process of hemodialysys may be partially responsible for triggering blood platelet apoptosis.
Źródło:
Engineering of Biomaterials; 2009, 12, no. 89-91; 29-30
1429-7248
Pojawia się w:
Engineering of Biomaterials
Dostawca treści:
Biblioteka Nauki
Artykuł
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:
The role of hematological parameters in differentiating Plasmodium falciparum and others – a study from Somalia
Autorzy:
Özdemir, Serdar
Algın, Abdullah
Altunok, İbrahim
Arslan, Ebubekir
Powiązania:
https://bibliotekanauki.pl/articles/2216801.pdf
Data publikacji:
2022-12-30
Wydawca:
Uniwersytet Rzeszowski. Wydawnictwo Uniwersytetu Rzeszowskiego
Tematy:
malaria
Plasmodium falciparum
Plasmodium vivax
platelets
Opis:
Introduction and aim. Accurate identification of Plasmodium species is important because of the differences in their treatment. We aimed to investigate the role of hematological and biochemical parameters in the differentiation of Plasmodium falciparum and other plasmodium species. Material and methods. This is a retrospective study. Patients admitted to the emergency department with signs and symptoms of malaria were included into the study. Patients with malaria were grouped as P. falciparum and others. Hematological parameters of two groups were compared by univariate and multivariate analysis. Statistical analysis was performed using the Jamovi. Results. A total of 107 patients were included in the study. According to univariant and multivariant analysis there was no difference in between two groups in the terms of blood urea nitrogen, aspartate aminotransferase, total bilirubin, hemoglobin, hematocrit, white blood cell count, platelet count, and mean platelet volume (in univariate analysis p values were 0.029, 0.011, 0.019, 0.171, 0.870, 0.307, 0.042, and 0.276, respectively and in multivariate analysis p values for blood urea nitrogen, aspartate aminotransferase, total bilirubin, hemoglobin, and platelet count were 0.100, 0.535, 0.328, and 0.213, respectively). Conclusion. The investigated hematological and biochemical parameters were found to be not valuable in predicting type of malaria. On the other hand, we recommend confirming the results of our study with larger samples and multicenter studies.
Źródło:
European Journal of Clinical and Experimental Medicine; 2022, 4; 430-434
2544-2406
2544-1361
Pojawia się w:
European Journal of Clinical and Experimental Medicine
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Drug-induced thrombocytopenia – etiology and alternative therapeutic approaches
Autorzy:
Rajashekaraiah, Vani
Berikai Ananthakrishna, Anusha
Powiązania:
https://bibliotekanauki.pl/articles/29519508.pdf
Data publikacji:
2023-09-30
Wydawca:
Uniwersytet Rzeszowski. Wydawnictwo Uniwersytetu Rzeszowskiego
Tematy:
alternative therapeutics
drug-induced thrombocytopenia
phytochemicals
platelets
Opis:
Introduction and aim. The cumulative incidence of drug-induced thrombocytopenia (DIT) is 10 cases per one million people per year with a prevalence of approximately 25% in critically ill patients. This review provides a comprehensive view of drug-induced thrombocytopenia, diagnosis, underlying mechanisms, common strategies in therapeutics, and potential alternatives. Material and methods. Databases such as “Google Scholar”, “PubMed”, “Medline” and “MDPI” was used for literature review with the keywords, “platelets”, “platelet disorders”, “thrombocytopenia”, “drug-induced”, “oxidative stress” “plant extracts”, “phytochemicals”, “antioxidants”, for the articles published between 2013-2023 and written in the English language. Analysis of the literature. Several antimicrobials, anti-cancer drugs, and antivirals are often reported to cause adverse effects during treatment, such as thrombocytopenia. A thorough understanding of the underlying pathophysiology is important for appropriate treatment. Even though an improvement in platelet count is observed after the discontinuation of the causative drug, there is a dire need for treatment in some cases due to associated complications. There are various pitfalls with conventional treatments which include clinical complications and lack of effectiveness. Conclusion. Interventions in therapeutics through antioxidants can aid in faster recovery. Various plant extracts and phytochemicals have been employed as therapeutics in platelet disorders due to their exceptional antioxidant activity. It is imperative to explore the bioactive components of natural products and their influence on platelet efficacy. Also, it highlights how antioxidants can be used as a safe, yet effective option as therapeutics for treating a complicated disorder such as DIT or be used as supplements to prevent adverse effects of existing treatments involving antibiotics and chemotherapeutics.
Źródło:
European Journal of Clinical and Experimental Medicine; 2023, 3; 617-626
2544-2406
2544-1361
Pojawia się w:
European Journal of Clinical and Experimental Medicine
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 role of acetylsalicylic acid and circulating microRNAs in primary prevention of cardiovascular events in patients with Diabetes Mellitus Type 2 - a review
Autorzy:
Chabior, A.
Pordzik, J.
Mirowska-Guzel, D.
Postuła, M.
Powiązania:
https://bibliotekanauki.pl/articles/2085138.pdf
Data publikacji:
2019
Wydawca:
Instytut Medycyny Wsi
Tematy:
diabetes mellitus
primary prevention
platelets
acetylsalicylic acid
microRNA
Opis:
Introduction. Type 2 diabetes mellitus (T2DM) is a common metabolic disorder, which carries a risk for atherosclerosis and cardiovascular impairment. The purpose of this review is to demonstrate the role of acetylsalicylic acid (ASA) in primary cardiovascular prevention in T2DM patients, as well as present an outline of microRNAs (miRNA) relevant to ASA therapy and should be evaluated as targets to improve treatment. Brief description of state of knowledge. Although the etiology of hypercoagulable state in T2DM is considered multifactorial, attention mainly focuses on platelet disturbances. Platelets in T2DM not only demonstrate intensified adhesion, activation, aggregation, and thrombin generation, but are likely to deliver miRNAs at specific sites of action in the cardiovascular system, hence contributing to the pathogenesis of cardiovascular events. Objective. Since cardiovascular disease (CVD) is currently the leading cause of mortality among T2DM patients, appropriate risk stratification and management is necessary to reduce morbidity and mortality in this group. A large number of T2DM patients show inadequate response to antiplatelet therapy, which currently revolves around ASA, despite compliance with treatment regimens proposed by the guidelines. Conclusions. The review shows that the use of ASA for primary prevention is beneficial in patients at high cardiovascular risk. However, it is important to select patients in whom ASA therapy will bring the most beneficial outcome with minimal risk for adverse effects. This can be potentially achieved with the use of unique biomarkers. The biologically diverse characteristics of miRNA make them a promising novel biomarker and potential tool for better risk stratification, as well as antiplatelet therapy optimization.
Źródło:
Annals of Agricultural and Environmental Medicine; 2019, 26, 4; 515-522
1232-1966
Pojawia się w:
Annals of Agricultural and Environmental Medicine
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:
QUINOLINIC ACID DOES NOT INFLUENCE COAGULATION PROFILE, NOR FIBRINOLYTIC ACTIVITY, UNDER PHYSIOLOGICAL CONDITIONS IN RATS.
Autorzy:
Leszczyńska, Agnieszka
Kamiński, Tomasz W.
Misztal, Tomasz
Cylwik, Bogdan
Pawlak, Dariusz
Powiązania:
https://bibliotekanauki.pl/articles/895276.pdf
Data publikacji:
2019-10-30
Wydawca:
Polskie Towarzystwo Farmaceutyczne
Tematy:
rats
coagulation
platelets
fibrinolysis
Quinolinic acid (QA)
uremic toxin
Opis:
Disturbances of hemostatic system are commonly observed in chronic kidney disease (CKD) patients. Along with CKD progression, the levels of tryptophan-derived uremic toxins increase, including quinolinic acid (QA). Objective of the study was to evaluate the effect of QA, a representative of tryptophan metabolites, on coagulation and fibrinolytic activity in male Wistar rats in vivo and platelet activity in vitro. Rats received QA dissolved in drinking water in doses of 3, 10, and 30 mg/kg (or water, VEH) for 14 days. Next, the following parameters were measured in the rat‘s whole blood or plasma ex vivo: thromboelastometric (ROTEM) parameters, standard coagulation parameters and fibrinolytic parameters. To evaluate the direct effect of QA on coagulation and platelet activity, blood from control rats was drawn and analyzed in vitro in the following scheme: samples of whole blood were incubated with QA (100µM) before thromboelastometric (ROTEM) analysis and collagen-induced platelet aggregation, or samples of platelet rich plasma (PRP) were incubated with QA (100µM, 1 and 2mM) 10 minutes before collagen (1µg/ml) or ADP (10µM)-induced platelet aggregation. QA administrated for 14 days in drinking water had no effect per se on activation of coagulation and fibrinolytic parameters in rats ex vivo. Similarly, no changes were observed in a whole blood incubated directly with QA regarding coagulation parameters or collagen-induced platelet aggregation. QA inhibited ADP-induced platelets aggregation in PRP only at higher concentrations of 1 and 2 mM and when aggregation was initiated by the addition of 10µM ADP in vitro.
Źródło:
Acta Poloniae Pharmaceutica - Drug Research; 2019, 76, 5; 863-871
0001-6837
2353-5288
Pojawia się w:
Acta Poloniae Pharmaceutica - Drug Research
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:
Hemostaza – temat zawsze aktualny
Haemostasis – issue always up to date
Autorzy:
Pleban, Eliza
Powiązania:
https://bibliotekanauki.pl/articles/1033885.pdf
Data publikacji:
2015
Wydawca:
Medical Communications
Tematy:
clot
coagulation system
fibrinolysis
haemostasis
platelets
hemostaza
skrzep
układ krzepnięcia
fibrynoliza
płytki krwi
Opis:
Haemostasis is a set of processes with the aim to maintain blood in the liquid state in the vascular bed, and in the case of damage to the vessel – to prevent extravasation by clot formation (initially a platelet clot and then a fibrin clot). The main components of haemostasis include: platelets, vessel wall, plasma coagulation system, endogenous inhibitors of coagulation and fibrinolytic system. The stream of blood is also an important factor. Haemostasis is divided into two main phases: coagulation and fibrinolysis. These two phases take place simultaneously and remain in equilibrium. The prevalence of any of these processes is the result of the advantage of enzyme complex activity over the complex of the other process. In everyday practice, every physician encounters drugs that affect haemostasis. At the end of the article, the most commonly used anticoagulants and antiplatelet agents available in Poland are described with the mechanisms of their action. The effect of oral anticoagulants results from the inhibition of the transformation of vitamin K1 which is essential for the production of coagulation factors II, VII, IX and X. Acenocoumarol and warfarin are currently available in Poland. The group of new oral anticoagulants includes direct inhibitors of activated factor X: rivaroxaban, apixaban and dabigatran – a potent, competitive and reversible direct thrombin inhibitor. Anticoagulants which are used parenterally include unfractionated heparin, low molecular weight heparins and fondaparinux. Antiplatelet drugs can be divided into two groups based on the mechanism of action – drugs acting through the metabolism of arachidonic acid (aspirin) and acting on the platelet membrane receptors (ticlopidine, clopidogrel and prasugrel).
Hemostaza to zespół procesów mających na celu utrzymanie krwi w stanie płynnym w łożysku naczyniowym, a w przypadku uszkodzenia naczynia – zapobieganie wynaczynieniu poprzez utworzenie skrzepu (początkowo płytkowego, następnie fibrynowego). Spośród głównych elementów hemostazy należy wymienić płytki krwi, ścianę naczyń krwionośnych, osoczowy układ krzepnięcia, endogenne inhibitory krzepnięcia i układ fibrynolizy. Istotnym czynnikiem jest także strumień przepływającej krwi. Najczęściej hemostazę dzieli się na dwa główne etapy: krzepnięcie i fibrynolizę. Oba te procesy zachodzą jednocześnie i pozostają w równowadze. Dominacja któregoś z nich to rezultat przewagi aktywności kompleksu enzymatycznego nad aktywnością kompleksu drugiego procesu. W codziennej praktyce każdy lekarz spotyka się z lekami wpływającymi na hemostazę – na końcu artykułu omówiono więc najpowszechniej stosowane leki przeciwkrzepliwe i przeciwpłytkowe dostępne w Polsce oraz mechanizmy ich działania. Działanie doustnych leków przeciwkrzepliwych wynika z hamowania przemiany witaminy K1, niezbędnej do wytwarzania w organizmie człowieka czynników krzepnięcia: II, VII, IX i X. Obecnie dostępne są acenokumarol i warfaryna. W grupie nowych doustnych antykoagulantów znalazły się bezpośrednie inhibitory aktywnego czynnika X: rywaroksaban, apiksaban i dabigatran, który jest silnym, kompetycyjnym, odwracalnym, bezpośrednim inhibitorem trombiny. Antykoagulanty stosowane parenteralnie to heparyna niefrakcjonowana, heparyny drobnocząsteczkowe i fondaparynuks. Ze względu na mechanizm działania leki przeciwpłytkowe można podzielić na dwie grupy: leki działające przez metabolizm kwasu arachidonowego (kwas acetylosalicylowy) i działające na receptory błonowe płytek krwi (tiklopidyna, klopidogrel, prasugrel).
Źródło:
Pediatria i Medycyna Rodzinna; 2015, 11, 2; 166-176
1734-1531
2451-0742
Pojawia się w:
Pediatria i Medycyna Rodzinna
Dostawca treści:
Biblioteka Nauki
Artykuł
Wyświetlanie 1-15 z 26

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