The Experts below are selected from a list of 165 Experts worldwide ranked by ideXlab platform
Beata Olas - One of the best experts on this subject based on the ideXlab platform.
-
Homocysteine and its thiolactone may promote apoptotic events in Blood Platelets in vitro.
Platelets, 2010Co-Authors: Beata Olas, Joanna Malinowska, Joanna RywaniakAbstract:The actions of homocysteine and its major metabolite, cyclic thioester, homocysteine thiolactone on endothelial cells, Blood Platelets, plasmatic fibrinogen and plasminogen – the important major components of haemostasis, regulating the flowing properties of Blood – are complex and sometimes controversial. Homocysteine (Hcys) can promote apoptosis in endothelial cells, but the role of Hcys and its thiolactone in the apoptotic process in Blood Platelets is unknown. In order to study the appearance of apoptosis in Platelets after treatment with the reduced form of Hcys or its thiolactone different markers were chosen: annexin V binding (phosphatidylserine exposure), platelet microparticle formation, mitochondrial membrane depolarization and αIIbβ3 expression in vitro. Apoptotic events and platelet activation were measured by a flow cytometer. In gel-filtered Platelets treated with different concentrations of the reduced form of Hcys (25, 50 and 100 µM, 10 min) a significant increase of phosphatidylserine ex...
-
comparative studies on homocysteine and its metabolite homocysteine thiolactone action in Blood Platelets in vitro
Platelets, 2008Co-Authors: Beata Olas, Magdalena Kedzierska, Barbara WachowiczAbstract:Homocysteine (Hcy), an intermediate formed during the catabolism of the essential dietary amino acid methionine, and its cyclic thioester, homocysteine thiolactone (TL) formed from Hcy in plasma, may be implicated in pathological haemostasis and atherosclerosis. The mechanism by which TL exerts the prothrombotic effect and influences Blood Platelets remains unclear. Activation of Blood Platelets plays an important role in prothrombotic events. The aim of our study was to establish and compare the influence of a reduced form of homocysteine (at final doses of 10–100 µM) and its cyclic thioester, homocysteine thiolactone (0.1–1 µM), on platelet activation induced by thrombin (platelet aggregation), on platelet protein modifications (determined by parameters such as level of protein carbonyl groups, 3-nitrotyrosine residues in proteins) and on superoxide anion radicals () generation using the model system in vitro. We have observed that TL, like its precursor, Hcy, stimulates the generation of in Platelets a...
-
Oxidative stress in Blood Platelets from schizophrenic patients.
Platelets, 2005Co-Authors: Anna Dietrich-muszalska, Beata Olas, Jolanta Rabe-jabłońskaAbstract:Oxidative stress in Blood Platelets is observed in various diseases, including neuropsychiatric disorders. The aim of our study was to evaluate oxidative stress in Blood Platelets from patients with schizophrenic disorders by measuring the activity of the platelet antioxidative enzyme, superoxide dismutase (SOD), concomitant with the level of thiobarbituric acid reactive species (TBARS). In Blood Platelets obtained from schizophrenic patients (with paranoid schizophrenia according to DSM-IV criteria) and from healthy volunteers the level of reactive oxygen species was also measured via chemiluminescence. In resting Blood Platelets from schizophrenic patients the chemiluminescence was higher than in Platelets from control subjects (P
-
inhibition of oxidative stress in Blood Platelets by different phenolics from yucca schidigera roezl bark
Nutrition, 2003Co-Authors: Beata Olas, Barbara Wachowicz, Anna Stochmal, Wieslaw OleszekAbstract:Abstract Objective We investigated the comparative effects of resveratrol ( trans -3,4′,5-trihydroxystilbene), trans -3,3′,5,5′tetrahydroxy-4′-methoxystilbene, and yuccaols A and C isolated from the bark of Yucca schidigera on oxidative stress in resting Blood Platelets and Blood Platelets activated by different agonists (thrombin or thrombin receptor activating peptide). Methods and results Tested phenolics (1–25 μg/mL) reduced, to different degrees, the level of reactive oxygen species measured by the luminol-dependent chemiluminescence and changed the production of O 2 − measured by the reduction of cytochrome c in resting Blood Platelets. They also inhibited the generation of free radicals in Blood Platelets activated by thrombin ( P P P > 0.05), whereas trans -3,3′,5,5′tetrahydroxy-4′-methoxystilbene and the alcohol yucca extract reduced lipid peroxidation in Blood Platelets ( P Conclusions Resveratrol and other phenolic compounds from the bark of Yucca schidigera inhibiting free radical generation in Blood Platelets may be beneficial in protecting against cardiovascular diseases when hyperactivity of Platelets is observed.
-
Resveratrol and vitamin C as antioxidants in Blood Platelets
Thrombosis research, 2002Co-Authors: Beata Olas, Barbara WachowiczAbstract:We investigated the effects of two different compounds with potential antioxidative action (found in many fruits, which can be used in therapy of cardiovascular disorders): trans-resveratrol (3,4',5-trihydroxystilbene) and vitamin C on oxidative stress in Blood Platelets. Oxidative stress in Blood Platelets was estimated by the measurement of: (1) the generation of superoxide radicals (O(2)(-*)) (reduction of cytochrome c) and other reactive oxygen species--ROS: H(2)O(2), singlet oxygen and organic radicals (chemiluminescence), (2) the production of thiobarbituric acid reactive substances (TBARS) and the level of conjugate dienes as markers of lipid peroxidation. We have shown that vitamin C at the concentrations of 750-3000 microM, but not at the concentration of 100 microM (prooxidative action) significantly inhibited peroxidation of lipids (measured by TBARS and conjugate dienes) and the production of ROS in Blood Platelets. After the incubation of Blood Platelets for 30 min at 37 degrees C with vitamin C at the concentration of 3000 microM, inhibition of ROS generation (above 90%) was achieved. The inhibition of ROS production caused by resveratrol at physiological plasma concentrations 0.05-2 microM was lower than by vitamin C. At the highest concentration of vitamin C used (3000 microM), the inhibition of O(2)(-*) generation was about 40%. Moreover, we did not observe any synergistic action of resveratrol and vitamin C at antioxidative dose (3000 microM) on the inhibition of lipid peroxidation and the production of O(2)(-*) or ROS in Blood Platelets. Resveratrol as an antioxidant reduced oxidative stress in Blood Platelets caused by vitamin C at prooxidative dose (100 microM).
Barbara Wachowicz - One of the best experts on this subject based on the ideXlab platform.
-
comparative studies on homocysteine and its metabolite homocysteine thiolactone action in Blood Platelets in vitro
Platelets, 2008Co-Authors: Beata Olas, Magdalena Kedzierska, Barbara WachowiczAbstract:Homocysteine (Hcy), an intermediate formed during the catabolism of the essential dietary amino acid methionine, and its cyclic thioester, homocysteine thiolactone (TL) formed from Hcy in plasma, may be implicated in pathological haemostasis and atherosclerosis. The mechanism by which TL exerts the prothrombotic effect and influences Blood Platelets remains unclear. Activation of Blood Platelets plays an important role in prothrombotic events. The aim of our study was to establish and compare the influence of a reduced form of homocysteine (at final doses of 10–100 µM) and its cyclic thioester, homocysteine thiolactone (0.1–1 µM), on platelet activation induced by thrombin (platelet aggregation), on platelet protein modifications (determined by parameters such as level of protein carbonyl groups, 3-nitrotyrosine residues in proteins) and on superoxide anion radicals () generation using the model system in vitro. We have observed that TL, like its precursor, Hcy, stimulates the generation of in Platelets a...
-
Effects of Lipopolysaccharides from Gram-Negative Bacteria on the Level of Thiols in Blood Platelets
Current Microbiology, 2005Co-Authors: Joanna Saluk-juszczak, Barbara Wachowicz, Edward Bald, Rafał GowackiAbstract:Lipopolysaccharide (endotoxin, LPS) activates Blood Platelets and stimulates generation of free radicals in these cells. The mechanism of platelet activation induced by LPS is not known. The aim of the present study was to examine how glutathione (GSH) and other thiol-containing compounds are involved in the oxidative stress in Blood Platelets caused by LPS. The HPLC technique has been used on the analysis of non-protein thiols from human Blood Platelets treated with lipopolysaccharides of different Gram-negative bacteria ( Proteus mirabilis, Escherichia coli, Klebsiella pneumoniae, and Pseudomonas aeruginosa ). Our results show that LPSs caused an increase (about 10%) of the level of reduced glutathione (GSH) and other nonprotein thiols such as cysteine (CSH) and cysteinylglycine (CGSH), whereas the total pool of these compounds was almost unchanged. LPS may react directly with thiols, since after incubation of LPSs with glutathione alone (in reduced form) we observed a distinct decrease of the level of platelet GSH.
-
inhibition of oxidative stress in Blood Platelets by different phenolics from yucca schidigera roezl bark
Nutrition, 2003Co-Authors: Beata Olas, Barbara Wachowicz, Anna Stochmal, Wieslaw OleszekAbstract:Abstract Objective We investigated the comparative effects of resveratrol ( trans -3,4′,5-trihydroxystilbene), trans -3,3′,5,5′tetrahydroxy-4′-methoxystilbene, and yuccaols A and C isolated from the bark of Yucca schidigera on oxidative stress in resting Blood Platelets and Blood Platelets activated by different agonists (thrombin or thrombin receptor activating peptide). Methods and results Tested phenolics (1–25 μg/mL) reduced, to different degrees, the level of reactive oxygen species measured by the luminol-dependent chemiluminescence and changed the production of O 2 − measured by the reduction of cytochrome c in resting Blood Platelets. They also inhibited the generation of free radicals in Blood Platelets activated by thrombin ( P P P > 0.05), whereas trans -3,3′,5,5′tetrahydroxy-4′-methoxystilbene and the alcohol yucca extract reduced lipid peroxidation in Blood Platelets ( P Conclusions Resveratrol and other phenolic compounds from the bark of Yucca schidigera inhibiting free radical generation in Blood Platelets may be beneficial in protecting against cardiovascular diseases when hyperactivity of Platelets is observed.
-
Resveratrol and vitamin C as antioxidants in Blood Platelets
Thrombosis research, 2002Co-Authors: Beata Olas, Barbara WachowiczAbstract:We investigated the effects of two different compounds with potential antioxidative action (found in many fruits, which can be used in therapy of cardiovascular disorders): trans-resveratrol (3,4',5-trihydroxystilbene) and vitamin C on oxidative stress in Blood Platelets. Oxidative stress in Blood Platelets was estimated by the measurement of: (1) the generation of superoxide radicals (O(2)(-*)) (reduction of cytochrome c) and other reactive oxygen species--ROS: H(2)O(2), singlet oxygen and organic radicals (chemiluminescence), (2) the production of thiobarbituric acid reactive substances (TBARS) and the level of conjugate dienes as markers of lipid peroxidation. We have shown that vitamin C at the concentrations of 750-3000 microM, but not at the concentration of 100 microM (prooxidative action) significantly inhibited peroxidation of lipids (measured by TBARS and conjugate dienes) and the production of ROS in Blood Platelets. After the incubation of Blood Platelets for 30 min at 37 degrees C with vitamin C at the concentration of 3000 microM, inhibition of ROS generation (above 90%) was achieved. The inhibition of ROS production caused by resveratrol at physiological plasma concentrations 0.05-2 microM was lower than by vitamin C. At the highest concentration of vitamin C used (3000 microM), the inhibition of O(2)(-*) generation was about 40%. Moreover, we did not observe any synergistic action of resveratrol and vitamin C at antioxidative dose (3000 microM) on the inhibition of lipid peroxidation and the production of O(2)(-*) or ROS in Blood Platelets. Resveratrol as an antioxidant reduced oxidative stress in Blood Platelets caused by vitamin C at prooxidative dose (100 microM).
-
generation of reactive oxygen species in Blood Platelets
Platelets, 2002Co-Authors: Barbara Wachowicz, Beata Olas, Halina Malgorzata Zbikowska, Andrzej BuczynskiAbstract:The generation of superoxide anion radicals (O . - 2 ) and the other reactive oxygen species (ROS) was estimated by means of cytochrome c reduction and chemiluminescence, as well in resting Blood Platelets and in Platelets stimulated by thrombin in the presence or absence of some inhibitors of pathways involved in platelet activation. We used allopurinol (xanthine oxidase inhibitor), wortmannin (PI 3-kinase inhibitor) and staurosporine (protein kinase C inhibitor). To determine the involvement of the glutathione in ROS generation, we used L-buthionine sulfoximine (BSO) which blocks GSH synthesis. Our results confirmed that thrombin stimulates the production of ROS concomitant with metabolism of arachidonate and production of malonyldialdehyde (MDA) in Blood Platelets ( P < 0.05) and showed that, in the presence of inhibitors, the generation of ROS in Platelets (resting and stimulated) was reduced. This indicates that xanthine oxidase, PI 3-kinase or protein kinase C take part in the formation of ROS in bl...
Miroslav Pecka - One of the best experts on this subject based on the ideXlab platform.
-
The influence of intrinsic coagulation pathway on Blood Platelets activation by oxidized cellulose.
Journal of Biomedical Materials Research Part A, 2007Co-Authors: P. Křı́žová, Másová L, Jiří Suttnar, Peter Salaj, Jiří Homola, Miroslav PeckaAbstract:Oxidized cellulose is an effective haemostat that works naturally to aid in Blood coagulation. The mechanism of its action is not very well understood. Little effect on Blood coagulation, but a pronounce decrease in platelet count has been reported upon the addition of the oxidized cellulose to the whole Blood. As a marker of platelet activation and aggregation we used serotonin release reaction and turbidity changes in time. We found that oxidized cellulose did not activate washed Platelets reconstituted in plasma-free medium or plasma-free medium with fibrinogen; no reduction of platelet count was observed. Serotonin release in platelet-rich plasma incubated with oxidized cellulose started in the range from 5 to 10 min. Serotonin release from Platelets reconstituted in plasma deficient in either coagulation factor V, VIII, IX, or XII was delayed. Blood Platelets activation by oxidized cellulose requires calcium ions present in dispersion of oxidized cellulose. Factor XIII deficiency had no influence on Blood Platelets activation by oxidized cellulose. Our results clearly indicate the significance of intrinsic coagulation pathway activation on Blood Platelets activation by oxidized cellulose and so indirectly on the haemostyptic effect of oxidized cellulose. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res 2007
-
The influence of intrinsic coagulation pathway on Blood Platelets activation by oxidized cellulose.
Journal of biomedical materials research. Part A, 2007Co-Authors: P Krízová, Jiří Suttnar, Peter Salaj, Jiří Homola, L Másová, Jan E. Dyr, Miroslav PeckaAbstract:Oxidized cellulose is an effective hemostat that works naturally to aid in Blood coagulation. The mechanism of its action is not very well understood. Little effect on Blood coagulation, but a pronounce decrease in platelet count has been reported upon the addition of the oxidized cellulose to the whole Blood. As a marker of platelet activation and aggregation we used serotonin release reaction and turbidity changes in time. We found that oxidized cellulose did not activate washed Platelets reconstituted in plasma-free medium or plasma-free medium with fibrinogen; no reduction of platelet count was observed. Serotonin release in platelet-rich plasma incubated with oxidized cellulose started in the range from 5 to 10 min. Serotonin release from Platelets reconstituted in plasma deficient in either coagulation factor V, VIII, IX, or XII was delayed. Blood Platelets activation by oxidized cellulose requires calcium ions present in dispersion of oxidized cellulose. Factor XIII deficiency had no influence on Blood Platelets activation by oxidized cellulose. Our results clearly indicate the significance of intrinsic coagulation pathway activation on Blood Platelets activation by oxidized cellulose and so indirectly on the hemostyptic effect of oxidized cellulose.
-
Hemostyptic effect of oxidized cellulose on Blood Platelets.
Sbornik lekarsky, 2003Co-Authors: L Másová, Jiří Suttnar, J. Ryšavá, Peter Salaj, Jakub Dostalek, Jiří Homola, Jan E. Dyr, Krízová P, K. Myška, Miroslav PeckaAbstract:Cellulose is one of the hemostyptic biomaterials, which are able to initiate or accelerate Blood coagulation at the site of their application. It belongs to surgical sealants. The mechanism of its action is not clearly understood. We studied the participation of Blood Platelets in this mechanism. As a marker of platelet activation we used serotonin release reaction. Serotonin release in platelet rich plasma incubated with various concentrations of oxidized cellulose (0.5%-2.0%) started in about 20 min. Washed Platelets were not directly activated by oxidized cellulose within one hour. Washed Platelets reconstituted in plasma obtained from two patients with coagulation factor XII deficiency were activated by oxidized cellulose with a prolonged lag phase. Our results demonstrate the significant influence of factor XII on Blood Platelets activation by oxidized cellulose.
Jiří Homola - One of the best experts on this subject based on the ideXlab platform.
-
The influence of intrinsic coagulation pathway on Blood Platelets activation by oxidized cellulose.
Journal of Biomedical Materials Research Part A, 2007Co-Authors: P. Křı́žová, Másová L, Jiří Suttnar, Peter Salaj, Jiří Homola, Miroslav PeckaAbstract:Oxidized cellulose is an effective haemostat that works naturally to aid in Blood coagulation. The mechanism of its action is not very well understood. Little effect on Blood coagulation, but a pronounce decrease in platelet count has been reported upon the addition of the oxidized cellulose to the whole Blood. As a marker of platelet activation and aggregation we used serotonin release reaction and turbidity changes in time. We found that oxidized cellulose did not activate washed Platelets reconstituted in plasma-free medium or plasma-free medium with fibrinogen; no reduction of platelet count was observed. Serotonin release in platelet-rich plasma incubated with oxidized cellulose started in the range from 5 to 10 min. Serotonin release from Platelets reconstituted in plasma deficient in either coagulation factor V, VIII, IX, or XII was delayed. Blood Platelets activation by oxidized cellulose requires calcium ions present in dispersion of oxidized cellulose. Factor XIII deficiency had no influence on Blood Platelets activation by oxidized cellulose. Our results clearly indicate the significance of intrinsic coagulation pathway activation on Blood Platelets activation by oxidized cellulose and so indirectly on the haemostyptic effect of oxidized cellulose. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res 2007
-
The influence of intrinsic coagulation pathway on Blood Platelets activation by oxidized cellulose.
Journal of biomedical materials research. Part A, 2007Co-Authors: P Krízová, Jiří Suttnar, Peter Salaj, Jiří Homola, L Másová, Jan E. Dyr, Miroslav PeckaAbstract:Oxidized cellulose is an effective hemostat that works naturally to aid in Blood coagulation. The mechanism of its action is not very well understood. Little effect on Blood coagulation, but a pronounce decrease in platelet count has been reported upon the addition of the oxidized cellulose to the whole Blood. As a marker of platelet activation and aggregation we used serotonin release reaction and turbidity changes in time. We found that oxidized cellulose did not activate washed Platelets reconstituted in plasma-free medium or plasma-free medium with fibrinogen; no reduction of platelet count was observed. Serotonin release in platelet-rich plasma incubated with oxidized cellulose started in the range from 5 to 10 min. Serotonin release from Platelets reconstituted in plasma deficient in either coagulation factor V, VIII, IX, or XII was delayed. Blood Platelets activation by oxidized cellulose requires calcium ions present in dispersion of oxidized cellulose. Factor XIII deficiency had no influence on Blood Platelets activation by oxidized cellulose. Our results clearly indicate the significance of intrinsic coagulation pathway activation on Blood Platelets activation by oxidized cellulose and so indirectly on the hemostyptic effect of oxidized cellulose.
-
Surface interactions of oxidized cellulose with fibrin(ogen) and Blood Platelets
Sensors and Actuators B-chemical, 2003Co-Authors: J. Ryšavá, Másová L, Jiří Suttnar, P. Křı́žová, J. Briestenský, I. Santar, Jakub Dostalek, Jiří Homola, Myska KAbstract:Abstract Hemostatic effects of oxidized cellulose are well known but the mechanism of its action is far from being well understood. Hemostatic (hemostyptic) biomaterials with their ability to initiate or accelerate thrombus formation belong to surgical sealants. Thrombus formation is a surface phenomenon. The exploitation of surface plasmon resonance sensing principle for the examination of interactions of oxidized cellulose with fibrinogen, fibrin and Blood Platelets is reported. Cellulose decreased and slowed down the interaction of immobilized fibrin monomer with fibrinogen as observed by surface plasmon resonance. Only weak interactions of cellulose with plasma proteins albumin and fibrinogen were observed. Delayed gelation and slower increase in turbidity occurred in fibrinogen–thrombin solutions in the presence of the cellulose. Platelets in plasma but not washed Platelets in a buffer were activated in the presence of cellulose. We suppose that activation of the coagulation contact system of Blood plasma initiated very likely by the negatively charged surface of the oxidized cellulose leads to the fibrin formation and activation and adhesion of Blood Platelets. The direct interactions of Platelets and fibrinogen with the cellulose seem to play a secondary role.
-
Hemostyptic effect of oxidized cellulose on Blood Platelets.
Sbornik lekarsky, 2003Co-Authors: L Másová, Jiří Suttnar, J. Ryšavá, Peter Salaj, Jakub Dostalek, Jiří Homola, Jan E. Dyr, Krízová P, K. Myška, Miroslav PeckaAbstract:Cellulose is one of the hemostyptic biomaterials, which are able to initiate or accelerate Blood coagulation at the site of their application. It belongs to surgical sealants. The mechanism of its action is not clearly understood. We studied the participation of Blood Platelets in this mechanism. As a marker of platelet activation we used serotonin release reaction. Serotonin release in platelet rich plasma incubated with various concentrations of oxidized cellulose (0.5%-2.0%) started in about 20 min. Washed Platelets were not directly activated by oxidized cellulose within one hour. Washed Platelets reconstituted in plasma obtained from two patients with coagulation factor XII deficiency were activated by oxidized cellulose with a prolonged lag phase. Our results demonstrate the significant influence of factor XII on Blood Platelets activation by oxidized cellulose.
Jiří Suttnar - One of the best experts on this subject based on the ideXlab platform.
-
The influence of intrinsic coagulation pathway on Blood Platelets activation by oxidized cellulose.
Journal of Biomedical Materials Research Part A, 2007Co-Authors: P. Křı́žová, Másová L, Jiří Suttnar, Peter Salaj, Jiří Homola, Miroslav PeckaAbstract:Oxidized cellulose is an effective haemostat that works naturally to aid in Blood coagulation. The mechanism of its action is not very well understood. Little effect on Blood coagulation, but a pronounce decrease in platelet count has been reported upon the addition of the oxidized cellulose to the whole Blood. As a marker of platelet activation and aggregation we used serotonin release reaction and turbidity changes in time. We found that oxidized cellulose did not activate washed Platelets reconstituted in plasma-free medium or plasma-free medium with fibrinogen; no reduction of platelet count was observed. Serotonin release in platelet-rich plasma incubated with oxidized cellulose started in the range from 5 to 10 min. Serotonin release from Platelets reconstituted in plasma deficient in either coagulation factor V, VIII, IX, or XII was delayed. Blood Platelets activation by oxidized cellulose requires calcium ions present in dispersion of oxidized cellulose. Factor XIII deficiency had no influence on Blood Platelets activation by oxidized cellulose. Our results clearly indicate the significance of intrinsic coagulation pathway activation on Blood Platelets activation by oxidized cellulose and so indirectly on the haemostyptic effect of oxidized cellulose. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res 2007
-
The influence of intrinsic coagulation pathway on Blood Platelets activation by oxidized cellulose.
Journal of biomedical materials research. Part A, 2007Co-Authors: P Krízová, Jiří Suttnar, Peter Salaj, Jiří Homola, L Másová, Jan E. Dyr, Miroslav PeckaAbstract:Oxidized cellulose is an effective hemostat that works naturally to aid in Blood coagulation. The mechanism of its action is not very well understood. Little effect on Blood coagulation, but a pronounce decrease in platelet count has been reported upon the addition of the oxidized cellulose to the whole Blood. As a marker of platelet activation and aggregation we used serotonin release reaction and turbidity changes in time. We found that oxidized cellulose did not activate washed Platelets reconstituted in plasma-free medium or plasma-free medium with fibrinogen; no reduction of platelet count was observed. Serotonin release in platelet-rich plasma incubated with oxidized cellulose started in the range from 5 to 10 min. Serotonin release from Platelets reconstituted in plasma deficient in either coagulation factor V, VIII, IX, or XII was delayed. Blood Platelets activation by oxidized cellulose requires calcium ions present in dispersion of oxidized cellulose. Factor XIII deficiency had no influence on Blood Platelets activation by oxidized cellulose. Our results clearly indicate the significance of intrinsic coagulation pathway activation on Blood Platelets activation by oxidized cellulose and so indirectly on the hemostyptic effect of oxidized cellulose.
-
Surface interactions of oxidized cellulose with fibrin(ogen) and Blood Platelets
Sensors and Actuators B-chemical, 2003Co-Authors: J. Ryšavá, Másová L, Jiří Suttnar, P. Křı́žová, J. Briestenský, I. Santar, Jakub Dostalek, Jiří Homola, Myska KAbstract:Abstract Hemostatic effects of oxidized cellulose are well known but the mechanism of its action is far from being well understood. Hemostatic (hemostyptic) biomaterials with their ability to initiate or accelerate thrombus formation belong to surgical sealants. Thrombus formation is a surface phenomenon. The exploitation of surface plasmon resonance sensing principle for the examination of interactions of oxidized cellulose with fibrinogen, fibrin and Blood Platelets is reported. Cellulose decreased and slowed down the interaction of immobilized fibrin monomer with fibrinogen as observed by surface plasmon resonance. Only weak interactions of cellulose with plasma proteins albumin and fibrinogen were observed. Delayed gelation and slower increase in turbidity occurred in fibrinogen–thrombin solutions in the presence of the cellulose. Platelets in plasma but not washed Platelets in a buffer were activated in the presence of cellulose. We suppose that activation of the coagulation contact system of Blood plasma initiated very likely by the negatively charged surface of the oxidized cellulose leads to the fibrin formation and activation and adhesion of Blood Platelets. The direct interactions of Platelets and fibrinogen with the cellulose seem to play a secondary role.
-
Hemostyptic effect of oxidized cellulose on Blood Platelets.
Sbornik lekarsky, 2003Co-Authors: L Másová, Jiří Suttnar, J. Ryšavá, Peter Salaj, Jakub Dostalek, Jiří Homola, Jan E. Dyr, Krízová P, K. Myška, Miroslav PeckaAbstract:Cellulose is one of the hemostyptic biomaterials, which are able to initiate or accelerate Blood coagulation at the site of their application. It belongs to surgical sealants. The mechanism of its action is not clearly understood. We studied the participation of Blood Platelets in this mechanism. As a marker of platelet activation we used serotonin release reaction. Serotonin release in platelet rich plasma incubated with various concentrations of oxidized cellulose (0.5%-2.0%) started in about 20 min. Washed Platelets were not directly activated by oxidized cellulose within one hour. Washed Platelets reconstituted in plasma obtained from two patients with coagulation factor XII deficiency were activated by oxidized cellulose with a prolonged lag phase. Our results demonstrate the significant influence of factor XII on Blood Platelets activation by oxidized cellulose.