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- ItemAcesso aberto (Open Access)Avaliação da agregação plaquetária e dosagem do fibrinogênio em pacientes com doenças cardiovasculares e sua correlação com o uso de aspirina e fatores de risco coronariano(Sociedade Brasileira de Cirurgia Cardiovascular, 2006-09-01) Gabriel, Sthefano Atique; Tristão, Cristiane Knopp; Izar, Luciana Cristante; Domingues, Carolina; Gabriel, Edmo Atique [UNIFESP]; Cliquet, Marcelo Gil; Faculdade de Medicina de Sorocaba; Universidade Federal de São Paulo (UNIFESP)OBJECTIVE: To evaluate aspirin resistance in patients with cardiovascular diseases and to compare the amount of serum fibrinogen in patients taking aspirin with those who do not. To correlate the platelet aggregation and serum fibrinogen to cardiovascular risk parameters. METHODS: Eighty-two patients were divided into two groups: Group 1 - 41 patients who took 100mg aspirin daily and Group 2 - 41 patients who did not utilized platelet antiaggregates. Epidemiological data were collected including age, gender and information on smoking and alcohol intake and serum fibrinogen and platelet aggregation were mesured. RESULTS: In the groups analyzed, advanced age (p=0.011), smoking (p=0.009) and alcoholism (p=0.007) were directly associated to the serum fibrinogenen level. There were no correlations between smoking, alcoholism, serum fibrinogen and platelet aggregation values (p>0.05). In Group 1, 29% of the patients presented with aspirin resistance. Of these, smokers (p=0.029) and the alcoholics (p=0.033) had higher serum fibrinogen levels. CONCLUSION: Aspirin resistance was present in a high number of patients. Moreover, advanced age, smoking and alcoholism had a direct influence on the serum fibrinogen levels.
- ItemSomente MetadadadosCan gamma-radiation modulate hemagglutinating and anticoagulant activities of PpyLL, a lectin from Phthirusa pyrifolia?(Elsevier Science Bv, 2017) Costa, Romero M. P. B.; Campos Albuquerque, Wendell Wagner; Silva, Mariana C. C. [UNIFESP]; de Paula, Raiana Apolinario; Melo, Mychely Sheila; Oliva, Maria L. V. [UNIFESP]; Figueiredo Porto, Ana LuciaBlood coagulation and platelet-dependent primary homeostasis are important defense mechanisms against bleeding and novel inhibitors have been researched to obtain pharmacological and clinical applications. In this work, the PpyLL, a lectin obtained from Phthirusa pyrifolia, was characterized in terms of its molecular structure and biological functions (anticoagulant, antiplatelet agreggation and hemagglutinating activities) in presence or absence of Gamma radiation exposure. Results revealed a lectin with secondary-structure content by approximately 49% of beta-sheet, 20% of beta-turn and 31% of disordered structure. Irradiation effect demonstrated possible different sites of function by lectin on anticoagulant and hemagglutinating activities, once a decrease about 80% was observed when compared the activities under 0.5 kGy of exposition to gamma radiation. An emphatic discussion about the use of gamma radiation as a possible modulator of the lectin activity was made, and once the ionizing radiation affected differently the anticoagulation and hemagglutinating activities, we speculated that the results are determined by selective molecular damages in different binding sites. PpyLL biological activities and gamma radiation modulation could be considered for future researches in biomedical field aiming possible medical applications. (C) 2017 Elsevier B.V. All rights reserved.
- ItemAcesso aberto (Open Access)Comparação entre ticagrelor e prasugrel na inibição do receptor P2Y12 em pacientes submetidos a terapia fármaco-invasiva: estudo randomizado sampa(Universidade Federal de São Paulo (UNIFESP), 2018-08-24) Guimaraes, Leonardo de Freitas Campos [UNIFESP]; Caixeta, Adriano Mendes [UNIFESP]; http://lattes.cnpq.br/9639977817621119; Universidade Federal de São Paulo (UNIFESP)Background: A pharmacodynamic comparison between ticagrelor and prasugrel after fibrinolytic therapy has not yet been performed. Methods: In the singlecenter, 50 consecutive STelevation myocardial infarction (STEMI) patients previously treated with clopidogrel and undergoing a pharmacoinvasive strategy were randomized to either a ticagrelor (n = 25) 180 mg loading dose followed by 90 mg bid, or a prasugrel (n = 25) 60 mg loading dose followed by 10 mg/day, initiated after fibrinolytic therapy but before angiography. Platelet reactivity was assessed with the VerifyNow P2Y12 assay at 0, 2, 6, and 24 h after randomization. Results: Mean times from fibrinolysis to prasugrel or ticagrelor administration were 11.1 ± 6.9 and 13.3 ± 6.3 h, respectively (p = 0.24). The values of PRU decreased significantly from baseline to 2 h (p < 0.001) and from 2 h to 6 h (p < 0.001) in both groups. There was no difference in PRU values between 6 h and 24 h. The mean PRU values at 0, 2, 6, and 24 h were 234.9, 127.8, 45.4, and 48.0 in the prasugrel group and 233.1, 135.1, 67.7, and 56.9 in the ticagrelor group, respectively. PRU values did not significantly differ between groups at any time period of the study. Conclusions: In patients with STEMI treated with fibrinolytic therapy, platelet inhibition after clopidogrel is suboptimal and can be further increased with more potent agents. Ticagrelor and prasugrel demonstrated a similar extent of P2Y12 receptor inhibition within 24 h, although maximal platelet inhibition after these potent agents was not achieved for 6 h.
- ItemAcesso aberto (Open Access)Efeitos da terapia combinada atorvastatina e clopidogrel na biodisponibilidade da estatina e na função plaquetária em pacientes com doença coronária estável(Sociedade Brasileira de Hemodinâmica e Cardiologia Intervencionista - SBHCI, 2010-06-01) Pinheiro, Luiz Fernando Muniz [UNIFESP]; Izar, Maria Cristina de Oliveira [UNIFESP]; Kasmas, Soraia Hani [UNIFESP]; França, Carolina Nunes [UNIFESP]; Fischer, Simone Cristina Matheus [UNIFESP]; Barbosa, Simone Pinto de Melo [UNIFESP]; Nucci, Gilberto de; Ilha, Jaime; Chen, Lu Chi; Carvalho, Antonio Carlos [UNIFESP]; Póvoa, Rui Manuel dos Santos [UNIFESP]; Bianco, Henrique Tria [UNIFESP]; Fonseca, Francisco Antonio Helfenstein [UNIFESP]; Universidade Federal de São Paulo (UNIFESP); Instituto GalenoBACKGROUND: Atorvastatin 80 mg is recommended in patients with coronary artery disease to reduce cardiovascular events, however, there is controversy regarding the pharmacokinetic interactions between high doses of statins and the concomitant use of clopidogrel, since they share the same biotransformation pathway. This study evaluated the effects of the atorvastatin/clopidogrel combination therapy on the pharmacokinetics of statins and on platelet function of patients with stable coronary artery disease receiving chronic statins METHOD: Patients were admitted four times (V1 to V4) to a day-clinic. Statin was discontinued seven days (D) before the first admission. Patients then received atorvastatin 80 mg (D1 to D22) and clopidogrel 75 mg/day (D8 to D29). Fasting blood samples were obtained at all time points for lipid measurements, platelet function tests (cone and plate technique), and quantification of atorvastatin plasma levels (liquid chromatography and mass spectrometry) RESULTS: The discontinuation of statins for one week changed the lipid profile (P < 0.05 vs. baseline), with an early improvement of all lipid parameters after the administration of atorvastatin 80 mg (P < 0.005; V1 > V2, V3 and V4). Platelet adhesion was lower with clopidogrel alone (P = 0.003; V4 < V1, V2 and V3), whereas platelet aggregation values were lower following the atorvastatin/clopidogrel combination therapy or clopidogrel alone when compared to the other time points (P < 0.0001; V3 and V4 < V1 and V2). The use of clopidogrel did not affect atorvastatin serum levels CONCLUSION: High-dose atorvastatin did not affect platelet responses to clopidogrel, however the short-term statin discontinuation worsened the lipid profile and platelet function.
- ItemAcesso aberto (Open Access)Effects of simvastatin/ezetimibe on microparticles, endothelial progenitor cells and platelet aggregation in subjects with coronary heart disease under antiplatelet therapy(Associação Brasileira de Divulgação Científica, 2014-05-02) Camargo, Luciano M.[UNIFESP]; França, Carolina Nunes [UNIFESP]; Izar, Maria Cristina de Oliveira [UNIFESP]; Bianco, Henrique Tria [UNIFESP]; Lins, Liliane S.; Barbosa, Simone Pinto de Melo [UNIFESP]; Pinheiro, Luiz Fernando Muniz [UNIFESP]; Fonseca, Francisco Antonio Helfenstein [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)It is not known whether the addition of ezetimibe to statins adds cardiovascular protection beyond the expected changes in lipid levels. Subjects with coronary heart disease were treated with four consecutive 1-week courses of therapy (T) and evaluations. The courses were: T1, 100 mg aspirin alone; T2, 100 mg aspirin and 40 mg simvastatin/10 mg ezetimibe; T3, 40 mg simvastatin/10 mg ezetimibe, and 75 mg clopidogrel (300 mg initial loading dose); T4, 75 mg clopidogrel alone. Platelet aggregation was examined in whole blood. Endothelial microparticles (CD51), platelet microparticles (CD42/CD31), and endothelial progenitor cells (CD34/CD133; CDKDR/CD133, or CD34/KDR) were quantified by flow cytometry. Endothelial function was examined by flow-mediated dilation. Comparisons between therapies revealed differences in lipids (T2 and T3T1 and T4, P=0.001). Decreased platelet aggregation was observed after aspirin (arachidonic acid, T1
- ItemAcesso aberto (Open Access)Hemorrhagic and thrombotic complications in patients with myeloproliferative diseases(Associação Paulista de Medicina - APM, 1997-12-01) Vignal, Carla Valladares [UNIFESP]; Lourenco, Dayse Maria [UNIFESP]; Noguti, Maria Aparecida Eiko [UNIFESP]; Chauffaille, Maria de Lourdes Lopes Ferrari [UNIFESP]; Kerbauy, José [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)OBJECTIVE: To correlate the incidence of hemorrhage and thrombosis to bleeding time (BT) and platelet aggregation in 27 consecutive patients with myeloproliferative diseases (MPD). DESIGN: Retrospective study. SETTING: Public tertiary referral center. PATIENTS: Eighteen patients with chronic myelogenous leukemia (CML), 5 with polycytemia vera (PV), 2 with essential thrombocytemia (ET) and 2 with idiopathic myelofibrosis (MF). Duke's BT and epinephrine-induced platelet aggregation were performed on the patients and on 10 healthy individuals. RESULTS: Eleven patients presented symptoms (41 %): 9 with hemorrhage (33%) and 5 with thrombosis (19%).There were less symptomatic patients in the CML group (28%) than in the other MPD (67%), without statistical significance (Fisher, p=0.06). Duke's BT was longer in symptomatic patients (Mann-Whitney, p<0.05). Platelet aggregation was abnormal in 7 patients (26%) and 71% of them were symptomatic (Fisher, p = 0.07). CONCLUSIONS: The high incidence of bleeding and thrombosis in patients with MPD was related to prolonged BT, but not to platelet aggregation abnormalities.
- ItemAcesso aberto (Open Access)Leucurogin, a new recombinant disintegrin cloned from Bothrops leucurus (white-tailed-jararaca) with potent activity upon platelet aggregation and tumor growth(Elsevier B.V., 2011-07-01) Higuchi, D. A.; Almeida, M. C.; Barros, C. C.; Sanchez, E. F.; Pesquero, P. R.; Lang, E. A. S.; Samaan, M.; Araujo, Ronaldo Carvalho [UNIFESP]; Pesquero, João Bosco [UNIFESP]; Pesquero, J. L.; Universidade Federal de Minas Gerais (UFMG); Univ Mogi das Cruzes; Proteobras Desenvolvimento Biotecnol Ltda; Fundacao Ezequiel Dias; Universidade Federal de São Paulo (UNIFESP)Disintegrins and disintegrins-like proteins are able to inhibit platelet aggregation and integrin-mediated cell adhesion. the aim of this study was to produce one disintegrin-like cloned from Bothrops leucurus venom gland and to characterize it regarding biological activity. the recombinant protein was purified by one step procedure involving anion-exchange chromatography (DEAE-cellulose) and presented a molecular mass of 10.4 kDa. the purified protein was able to inhibit platelet aggregation induced by collagen (IC(50) = 0.65 mu M) and to inhibit growth of Ehrlich tumor implanted in mice by more than 50% after 7 days administration of 10 mu g/day. No effects were observed upon adenosine 5'diphosphate (ADP)-and arachidonic acid (AA)-induced platelet aggregation. the recombinant protein was recognized by an antibody specific for jararhagin one metalloproteinase isolated from Bothrops jararaca venom, and therefore it was named leucurogin. Anti-angiogenesis effect of leucurogin was evaluated by the sponge implant model. After 7 days administration leucurogin inhibited, in a dose dependent way, the vascularization process in the sponge. Leucurogin represents a new biotechnological tool to understand biological processes where disintegrins-like are involved and may help to characterize integrins that can be involved in development and progression of malignant cells. (C) 2011 Elsevier B.V. All rights reserved.
- ItemSomente MetadadadosA novel phospholipase A2, BJ-PLA2, from the venom of the snake Bothrops jararaca: Purification, primary structure analysis, and its characterization as a platelet-aggregation-inhibiting factor(Academic Press Inc, 1999-07-01) Serrano, Solange Maria de Toledo [UNIFESP]; Reichl, Antonia P.; Mentele, Reinhard; Auerswald, Ennes A.; Santoro, Marcelo Larami; Sampaio, Claudio Augusto Machado [UNIFESP]; Camargo, Antonio Carlos Martins de [UNIFESP]; Assakura, Marina Tizuko; Inst Butantan; Universidade Federal de São Paulo (UNIFESP); Univ MunichThis paper describes the isolation and primary structure analysis of a new phospholipase A2 with platelet-aggregation-inhibiting activity from the venom of Bothrops jararaca. the protein, named BJ-PLA2, was isolated by means of ammonium sulfate precipitation and anion-exchange and reversed-phase chromatographies and behaved as a homogeneous single-chain protein on SDS-PAGE. Its amino acid sequence was determined by N-terminal sequencing and analysis of overlapped chemical and proteolytic fragments by automated Edman degradation and mass spectometry determination. BJ-PLA2 consists of 124 amino acid residues and has the structural features of snake venom class II phospholipases A2, Chemical modification with p-bromophenacylbromide caused complete loss of enzymatic activity and partially affected the platelet-aggregation-inhibiting activity of BJ-PLA2. (C) 1999 Academic Press.
- ItemSomente MetadadadosPlasma kallikrein enhances platelet aggregation response by subthreshold doses of ADP(Elsevier France-Editions Scientifiques Medicales Elsevier, 2017) Ottaiano, Tatiana F. [UNIFESP]; Andrade, Sheila S. [UNIFESP]; de Oliveira, Cleide [UNIFESP]; Silva, Mariana C. C. [UNIFESP]; Buri, Marcus V. [UNIFESP]; Juliano, Maria A. [UNIFESP]; Girao, Manoel J. B. C. [UNIFESP]; Sampaio, Misako U. [UNIFESP]; Schmaier, Alvin H.; Wlodawer, Alexander; Maffei, Francisco H. A.; Oliva, Maria Luiza V. [UNIFESP]Human plasma kallikrein (huPK) potentiates platelet responses to subthreshold doses of ADP, although huPK itself, does not induce platelet aggregation. In the present investigation, we observe that huPK pretreatment of platelets potentiates ADP-induced platelet activation by prior proteolysis of the G-protein -coupled receptor PAR-1. The potentiation of ADP-induced platelet activation by huPK is mediated by the integrin alpha(IIb)beta(3) through interactions with the KGD/KGE sequence motif in huPK. Integrin alpha(IIb)beta(3) is a cofactor for huPK binding to platelets to support PAR-1 hydrolysis that contributes to activation of the ADP signaling pathway. This activation pathway leads to phosphorylation of Src, AktS(473), ERK1/2, and p38 MAPK, and to Cat(2+) release. The effect of huPK is blocked by specific antagonists of PAR-1 (SCH 19197) and alpha(IIb)beta(3) (abciximab) and by synthetic peptides comprising the KGD and KGE sequence motifs of huPK. Further, recombinant plasma kallikrein inhibitor, rBbKI, also blocks this entire mechanism. These results suggest a new function for huPK. Formation of plasma kallikrein lowers the threshold for ADP-induced platelet activation. The present observations are consistent with the notion that plasma kallikrein promotes vascular disease and thrombosis in the intravascular compartment and its inhibition may ameliorate cardiovascular disease and thrombosis. (C) 2017 Elsevier B.V. and Societe Francaise de Biochimie et Biologie Moleculaire (SFBBM). All rights reserved.
- ItemSomente MetadadadosPurification and partial characterization of two phospholipases A(2) from Bothrops leucurus (white-tailed-jararaca) snake venom(Elsevier B.V., 2007-03-01) Higuchi, Debora Ayame; Barbosa, Christiano Marcello Vaz; Bincoletto, Claudia; Chagas, Jair Ribeiro; Magalhaes, Arinos; Richardson, Michael; Sanchez, Eladio Flores; Pesquero, João Bosco [UNIFESP]; Araújo, Ronaldo de Carvalho; Pesquero, Jorge Luiz; Univ Mogi Das Cruzes; Universidade Federal de São Paulo (UNIFESP); Universidade Federal de Minas Gerais (UFMG)Two proteins with phospholipase A(2) (PLA(2)) activity were purified to homogeneity from Bothrops leucurus (white-tailed-jararaca) snake venom through three chromatographic steps: Conventional gel filtration on Sephacryl S-200, ion-exchange on Q-Sepharose and reverse phase on Vydac C4 HPLC column. the molecular mass for both enzymes was estimated to be approximately 14 kDa by SDS-PAGE. the N-terminal sequences (48 residues) show that one enzyme presents lysine at position 48 and the other an aspartic acid in this position, and therefore they were designated blK-PLA(2) and blD-PLA(2) respectively. blK-PLA(2) presented negligible levels of PLA(2) activity as compared to that of blD-PLA(2). the PLA(2) activity of both enzymes is Ca2+-dependent. blD-PLA(2) did not have any effect upon platelet aggregation induced by arachidonic acid, ADP or collagen, but strongly inhibits coagulation and is able to stimulate Ehrlich tumor growth but not angiogenesis. (c) 2006 Elsevier Masson SAS. All rights reserved.
- ItemAcesso aberto (Open Access)Purification, primary structure and potential functions of a novel lectin from Bauhinia forficata seeds(Elsevier B.V., 2012-07-01) Silva, Mariana Cristina Cabral [UNIFESP]; Santana, Lucimeire Aparecida de [UNIFESP]; Mentele, Reinhard; Ferreira, Rodrigo da Silva [UNIFESP]; Miranda, Antonio [UNIFESP]; Silva-Lucca, Rosemeire Aparecida; Sampaio, Misako Uemura [UNIFESP]; Correia, Maria Tereza dos Santos; Oliva, Maria Luiza Vilela [UNIFESP]; Universidade Federal de São Paulo (UNIFESP); Univ Estadual Oeste Parana; Universidade Federal de Pernambuco (UFPE); Inst Clin Neuroimmunol LMU; Max Planck Inst BiochemA new lectin. Bfl. was purified from Bauhinia forficata seeds by ammonium sulfate fractionation. DEAE-Sephadex ion exchange chromatography, Sepharose-4B and chitin affinity chromatographies and Superdex 75 size exclusion chromatography. the molecular homogeneity and purity of BfL were assessed by reversed-phase H PLC. BfL appeared as a single band of approximately 27.0 kDa on SDS-PAGE under non-reducing and reducing conditions, and its molecular weight was determined to be 27,850 Da by LC/ESI-MS. Bit is a glycoprotein with a carbohydrate content of 6.24% determined by the phenol-sulfuric acid method. Fetuin, asialofetuin, thyroglobulin and azocasein inhibited the hemagglutinating activity of BfL, whereas saccharides did not. Bfl hemagglutinating activity was stable at 100 degrees C for 30 min, pH-dependent, with the highest activity at pH 6.0, and metal-independent. the primary structure of BfL shows similarity with other lectins from the genus Bauhinia. Deconvolution of the BfL circular dichroism (CD) spectrum indicated the presence of alpha-helix and beta structures. BfL increases coagulation time, but this effect is not related to human plasma kallikrein or human factor Xa inhibition. Bfl also inhibits ADP- and epinephrine-induced platelet aggregation in a dose-dependent manner and is the only currently described lectin from Bauhinia that exhibits anticoagulant and antiplatelet aggregating properties. (c) 2012 Elsevier B.V. All rights reserved.