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1.
Biochem Biophys Res Commun ; 712-713: 149946, 2024 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-38643717

RESUMO

Platelets are small anucleate cells that play a key role in thrombosis and hemostasis. Our group previously identified apolipoprotein A-IV (apoA-IV) as an endogenous inhibitor of thrombosis by competitive blockade of the αIIbß3 integrin on platelets. ApoA-IV inhibition of platelets was dependent on the N-terminal D5/D13 residues, and enhanced with absence of the C-terminus, suggesting it sterically hinders its N-terminal platelet binding site. The C-terminus is also the site of common apoA-IV polymorphisms apoA-IV-1a (T347S) and apoA-IV-2 (Q360H). Interestingly, both are linked with an increased risk of cardiovascular disease, however, the underlying mechanism remains unclear. Here, we generated recombinant apoA-IV and found that the Q360H or T347S polymorphisms dampened its inhibition of platelet aggregation in human platelet-rich plasma and gel-filtered platelets, reduced its inhibition of platelet spreading, and its inhibition of P-selectin on activated platelets. Using an ex vivo thrombosis assay, we found that Q360H and T347S attenuated its inhibition of thrombosis at both high (1800s-1) and low (300s-1) shear rates. We then demonstrate a conserved monomer-dimer distribution among apoA-IV WT, Q360H, and T347S and use protein structure modelling software to show Q360H and T347S enhance C-terminal steric hindrance over the N-terminal platelet-binding site. These data provide critical insight into increased cardiovascular risk for individuals with Q360H or T347S polymorphisms.


Assuntos
Apolipoproteínas A , Plaquetas , Agregação Plaquetária , Trombose , Humanos , Trombose/genética , Trombose/metabolismo , Agregação Plaquetária/efeitos dos fármacos , Agregação Plaquetária/genética , Plaquetas/metabolismo , Plaquetas/efeitos dos fármacos , Polimorfismo Genético , Apoproteína(a)/genética , Apoproteína(a)/metabolismo , Apoproteína(a)/química , Selectina-P/genética , Selectina-P/metabolismo
2.
J Clin Med ; 12(24)2023 Dec 08.
Artigo em Inglês | MEDLINE | ID: mdl-38137642

RESUMO

BACKGROUND: Direct oral anticoagulants (DOACs) are widely used in patients with atrial fibrillation and venous thromboembolism. The lack of the need for laboratory monitoring and a better safety than vitamin K antagonists (VKAs) has probably changed the quality of life of patients on these oral anticoagulants. This was a real-life prospective observational cohort study. The aim was to evaluate if a long-term treatment with DOACs could offer a better quality of life than VKAs. Moreover, age, gender, education level, time in therapeutic range for VKAs, taking medication once or twice a day for DOACs, the total daily number of medications and thrombotic and bleeding complications were considered as variables probably associated with the quality of life of these patients. METHODS: Between January and December 2021, the Duke Anticoagulation Satisfaction Scale (DASS) 25-items was administered as an interview to patients on either VKAs or DOACs therapy. During the follow-up period, all of the patients were closely monitored to evaluate possible bleeding and thrombotic events. RESULTS: The analysis included 300 outpatients treated with VKAs and 254 treated with DOACs. In general, the quality of life was better in patients taking DOACs (DASS total score: DOACs = 44.7, 42.9-46.5 vs. VKAs = 51, 49.2-52.8, p < 0.0001) as the daily-life limitations, hassles and burdens and the psychological impact were less important than in patients on VKAs therapy. CONCLUSIONS: VKAs negatively influence the daily-life of the patients in terms of both less satisfaction and time-consuming tasks. DOACs confer a better quality of life even if some concerns emerge from not knowing how their therapy is working.

3.
Thromb Res ; 221: 173-182, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36402603

RESUMO

BACKGROUND: The balance between thrombosis and hemostasis is a difficult issue during extracorporeal membrane oxygenation (ECMO) support. The pathogenesis leading to thrombotic complications during ECMO support is not well understood. Neutrophil extracellular traps (NETs) were reported to participate in thrombosis and have a key role in inflammation. This study aimed to explore the role of NETs in thrombosis during ECMO support and investigate NETs as a predictive biomarker for thrombotic complications during ECMO assistance. METHODS: Ten ovine models of ECMO support were established. Animals were then randomly divided into 2 groups (5 sheep/group): venoarterial (VA) ECMO group and venovenous (VV) ECMO group. The venous blood samples were collected at different time points. Markers of NETs were detected in plasma, neutrophils, and thrombi from the vessels and membrane. Moreover, circulating NETs levels in 8 adults treated in the intensive care unit (ICU) who received VA-ECMO and 8 healthy controls were detected; patient survival was also recorded. RESULTS: In vivo study showed that neutrophils and NETs markers (dsDNA and citH3) levels were significantly elevated 6 h after ECMO compared to baseline. Isolated neutrophils from fresh blood at 6 h could release more NETs. dsDNA and citH3 levels were significantly higher in the VA mode than in the VV mode. NETs were found in thrombi from the vessel and membrane. Clinical data further revealed that dsDNA, citH3, and nucleosomes were higher in patients who received ECMO than in healthy controls. CONCLUSIONS: These data suggest NETs might be associated with thrombus during ECMO support, especially in the VA mode. These findings provide new insight into preventing thrombotic complications by targeting NETs. Also, NETs may potentially become an early warning biomarker for thrombosis under ECMO assistance.


Assuntos
Armadilhas Extracelulares , Oxigenação por Membrana Extracorpórea , Trombose , Animais , Ovinos , Oxigenação por Membrana Extracorpórea/efeitos adversos , Trombose/etiologia , Modelos Animais
4.
Thromb Res ; 218: 72-82, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-36027629

RESUMO

Therapeutic anticoagulation remains a fundamental backbone in the treatment and prevention of venous thromboembolism. However, while modern therapies are increasingly safe, anticoagulation is not without risks, particularly in those at high risk for or with recent bleeding. When weighing concurrent risks and benefits in each challenging clinical scenario, an individualized assessment of the risk and acuity of bleeding should be balanced by the indication for anticoagulation. Addressing modifiable risk factors and routine re-evaluation of any changes in this balance is critical. This review outlines available data and current guidelines for the management of anticoagulation in high-risk populations, including those with thrombocytopenia, elderly and high-fall risk, inherited bleeding disorders, and in acute coronary syndrome. We also examine management after clinically significant bleeding episodes, including intracranial hemorrhage, gastrointestinal bleeding, hemoptysis, retroperitoneal bleeding, hematuria, and abnormal uterine bleeding. The aim is to provide a comprehensive review of available literature to guide clinicians in providing optimal, safe, and individualized care for patients in these challenging scenarios.


Assuntos
Trombocitopenia , Tromboembolia Venosa , Idoso , Anticoagulantes/uso terapêutico , Coagulação Sanguínea , Hemorragia/induzido quimicamente , Hemorragia/complicações , Hemorragia/prevenção & controle , Humanos , Trombocitopenia/induzido quimicamente , Tromboembolia Venosa/etiologia
5.
Haemophilia ; 28 Suppl 4: 11-17, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35521725

RESUMO

Progress in both basic and translational research into the molecular mechanisms of VWD can be seen in multiple fields. GENETICS OF VWD: In the past several decades, knowledge of the underlying pathogenesis of von Willebrand disease (VWD) has increased tremendously, thanks in no small part to detailed genetic mapping of the von Willebrand Factor (VWF) gene and advances in genetic and bioinformatic technology. However, these advances do not always easily translate into improved management for patients with VWD and low-VWF levels. VWD AND PREGNANCY: For example, the treatment of pregnant women with VWD both pre- and postpartum can be complicated. While knowledge of the VWF genotype at some amino acid positions can aid in knowledge of who may be at increased risk of thrombocytopenia or insufficient increase in VWF levels during pregnancy, in many cases, VWF levels and bleeding severity is highly heterogeneous, making monitoring recommended during pregnancy to optimize treatment strategies. VWF AND COVID-19: New challenges related to the consequences of dysregulation of hemostasis continue to be discovered. The ongoing COVID-19 pandemic has highlighted that VWF has additional biological roles in the regulation of inflammatory disorders and angiogenesis, disruption of which may contribute to COVID-19 induced vasculopathy. Increased endothelial cell activation and Weibel-Palade body exocytosis in severe COVID-19 lead to markedly increased plasma VWF levels. Coupled with impairment of normal ADAMTS13 multimer regulation, these data suggest a role for VWF in the pathogenesis underlying pulmonary microvascular angiopathy in severe COVID-19. CONCLUSION: With the increased affordability and availability of next-generation sequencing techniques, as well as a push towards a multi-omic approach and personalized medicine in human genetics, there is hope that translational research will improve VWD patient outcomes.


Assuntos
COVID-19 , Doenças de von Willebrand , Feminino , Genótipo , Humanos , Pandemias , Gravidez , Doenças de von Willebrand/complicações , Doenças de von Willebrand/genética , Fator de von Willebrand/metabolismo
6.
J Matern Fetal Neonatal Med ; 35(17): 3259-3269, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32933344

RESUMO

BACKGROUND: Disseminated Intravascular Coagulation (DIC) is a life-threatening condition. Hemolysis, Elevated Liver enzymes and Low Platelets (HELLP) syndrome is one of the obstetrical syndromes mostly associated with DIC and thus, high rates of fatal complications. There is a lack of information regarding epidemiologic and clinical characteristics of women who developed HELLP syndrome with and without DIC. Additionally, until now, there is no adapted and widely accepted way to diagnose DIC among pregnant women presenting with HELLP syndrome, despite the evident maternal mortality linked to the disease.Objectives: (1) Address the gaps in knowledge regarding the prevalence, epidemiologic and clinical characteristics of women with HELLP syndrome who develop DIC; and (2) determine the risk factors for the development of DIC among women with HELLP syndrome. STUDY DESIGN: This was a population-based retrospective cohort study, including all women who delivered at the Soroka University Medical Center between the years 2001-2017. The study population was divided into three groups: (1) comparison group (n = 207,266 deliveries); (2) HELLP syndrome without DIC (n = 320); (3) HELLP syndrome with DIC (n = 21). The diagnosis of DIC was based on the ICD-9 code as recorded in the obstetrical database of the Soroka University Medical Center. The coding is based on the diagnosis made by the attending physician during hospitalization. RESULTS: (1) The rate of HELLP syndrome in the study population was 0.16% (341/207,607), of them 6.16% (21/341) had DIC; (2) among patients with HELLP syndrome, those with DIC had a higher median gravidity and parity; (3) a higher rate of severe maternal morbidity including blood product transfusion, placental abruption, eclampsia, acute renal failure and maternal death was observed in those who had HELLP syndrome and DIC compared to those with HELLP syndrome without DIC and the comparison group (p-value <.001 for comparison among the three groups); (4) among women with HELLP syndrome, those with DIC had a longer median PT difference, higher serum creatinine and lower AST as well as ALT median concentrations than those without DIC; (5) patients with HELLP syndrome and DIC had a higher rate of stillbirth and postpartum death than patients in the other groups (p-value <.001 for comparison among the three groups); and (6) placental abruption was an independent risk factor for the development of DIC in women with HELLP syndrome (p-value <.001). CONCLUSIONS: (1) Among women with HELLP syndrome, those who developed DIC had a higher rate of maternal and neonatal morbidity and mortality than those without DIC; and (2) placental abruption, but not abnormal liver function, was an independent risk factor for the development of DIC in women with HELLP syndrome.


Assuntos
Descolamento Prematuro da Placenta , Coagulação Intravascular Disseminada , Síndrome HELLP , Hepatopatias , Descolamento Prematuro da Placenta/epidemiologia , Coagulação Intravascular Disseminada/epidemiologia , Coagulação Intravascular Disseminada/etiologia , Feminino , Hemólise , Humanos , Recém-Nascido , Hepatopatias/complicações , Placenta , Gravidez , Estudos Retrospectivos , Natimorto
7.
J Res Med Sci ; 26: 102, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34899940

RESUMO

BACKGROUND: The coronavirus disease 2019 (COVID-19) presents various phenotypes from asymptomatic involvement to death. Disseminated intravascular coagulopathy (DIC) is among the poor prognostic complications frequently observed in critical illness. To improve mortality, a timely diagnosis of DIC is essential. The International Society on Thrombosis and Hemostasis (ISTH) introduced a scoring system to detect overt DIC (score ≥5) and another category called sepsis-induced coagulopathy (SIC) to identify the initial stages of DIC (score ≥4). This study aimed to determine whether clinicians used these scoring systems while assessing COVID-19 patients and the role of relevant biomarkers in disease severity and outcome. MATERIALS AND METHODS: An exhaustive search was performed according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses, using Medline, Embase, Cochrane, CINAHL, and PubMed until August 2020. Studies considering disease severity or outcome with at least two relevant biomarkers were included. For all studies, the definite, maximum, and minimum ISTH/SIC scores were calculated. RESULTS: A total of 37 papers and 12,463 cases were reviewed. Studies considering ISTH/SIC criteria to detect DIC suggested a higher rate of ISTH ≥5 and SIC ≥4 in severe cases and nonsurvivors compared with nonsevere cases and survivors. The calculated ISTH scores were dominantly higher in severe infections and nonsurvivors. Elevated D-dimer was the most consistent abnormality on admission. CONCLUSION: Higher ISTH and SIC scores positively correlate with disease severity and death. In addition, more patients with severe disease and nonsurvivors met the ISTH and SIC scores for DIC. Given the high prevalence of coagulopathy in COVID-19 infection, dynamic monitoring of relevant biomarkers in the form of ISTH and SIC scoring systems is of great importance to timely detect DIC in suspicious patients.

8.
Int J Cardiol Heart Vasc ; 36: 100850, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34401468

RESUMO

BACKGROUND: The optimal antithrombotic strategy, especially regarding oral anticoagulants (OACs) for atrial fibrillation (AF) patients with bleeding and thrombosis risk after percutaneous coronary intervention (PCI), remains unknown. This study explored the optimal oral anticoagulants for AF patients after PCI using a meta-analysis. METHODS: Randomised controlled trials were identified from PubMed, Embase, and the Cochrane Library through December 2020. Risk ratios, 95% confidence intervals, and random-effects models were used to compare different antithrombotic strategies through network meta-analysis, and the combination of antithrombotic agents was ranked according to the surface under the cumulative ranking curve and rankograms. Interval plots were drawn to observe pairwise comparisons between the different strategies. RESULTS: Five studies of 11,532 patients were included. Factor IIa inhibitor 110 mg bid plus a P2Y12 inhibitor had the greatest advantage for reducing Thrombolysis In Myocardial Infarction (TIMI) major or minor bleeding; Factor Xa inhibitor plus a P2Y12 inhibitor had the greatest advantage for reducing International Society on Thrombosis and Hemostasis major bleeding. For patients at risk of stroke plus all-cause death, factor IIa inhibitor 150 mg bid plus a P2Y12 inhibitor should be prioritised, and for those at risk of myocardial infarction and stent thrombosis, vitamin K antagonists plus a P2Y12 inhibitor were preferred. CONCLUSION: Factor IIa inhibitor 110 mg, factor IIa inhibitor 150 mg, factor Xa inhibitor and vitamin K antagonists should be selected in different situations.

9.
Oncologist ; 26(5): 427-432, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33523555

RESUMO

Patients with brain tumors are at high risk for thromboembolic complications and frequently require anticoagulation. Direct oral anticoagulants (DOACs) are a less burdensome treatment for cancer-associated thrombosis with safety and efficacy comparable to those of low molecular weight heparin (LMWH); however, there are few data to support the use of DOACs in patients with brain tumors. The purpose of this study was to better understand the safety profile of anticoagulants in patients with primary and metastatic brain tumors, with particular interest in the safety and efficacy of DOACs. Our hypothesis was that DOACs are as safe and effective as LWMH in this population. This study was conducted through a single-center retrospective chart review of 125 patients with primary and metastatic brain tumors on anticoagulation. Our primary outcomes were major bleeding and intracranial hemorrhage (ICH), with secondary outcomes of minor bleeding and recurrent thrombosis. The rate of major bleeding was 26% in the LMWH group versus 9.6% in the DOAC group (p = .03). The rate of ICH was 15% in the LMWH group versus 5.8% in the DOAC group (p = .09). The severity of ICH in both groups was low with median Common Terminology Criteria for Adverse Events version 5 scores of 2 in the LMWH group and 3 in the DOAC group. The rates of minor bleeding and recurrent thrombosis were low in both groups. Our conclusion is that DOAC use in patients with brain tumors is not associated with increased rates of major bleeding compared with LMWH and is a safe and effective option. IMPLICATIONS FOR PRACTICE: Patients with brain tumors are at high risk for venous thromboembolism and frequently require anticoagulation. Direct oral anticoagulants (DOACs) are less burdensome than low molecular weight heparin (LMWH) for treatment of thromboembolism, but there is concern in the community over increased risk of bleeding. This study provides much-needed objective evidence that there are fewer major bleeding events in patients with brain tumors on DOACs compared to LMWH with similar efficacy. As the paradigm of anticoagulation in patients with cancer shifts from LWMH toward DOACs, this work is particularly meaningful as it suggests DOACs are safe and effective for patients with brain tumors.


Assuntos
Neoplasias Encefálicas , Neoplasias , Tromboembolia Venosa , Administração Oral , Anticoagulantes/efeitos adversos , Neoplasias Encefálicas/complicações , Neoplasias Encefálicas/tratamento farmacológico , Heparina de Baixo Peso Molecular/efeitos adversos , Humanos , Neoplasias/tratamento farmacológico , Estudos Retrospectivos
11.
Artigo em Inglês | MEDLINE | ID: mdl-33001021

RESUMO

Platelets are small blood cells known primarily for their ability to adhere and aggregate at injured vessels to arrest bleeding. However, when triggered under pathological conditions, the same adaptive mechanism of platelet adhesion and aggregation may cause thrombosis, a primary cause of heart attack and stroke. Over recent decades, research has made considerable progress in uncovering the intricate and dynamic interactions that regulate these processes. Integrins are heterodimeric cell surface receptors expressed on all metazoan cells that facilitate cell adhesion, movement, and signaling, to drive biological and pathological processes such as thrombosis and hemostasis. Recently, our group discovered that the plexin-semaphorin-integrin (PSI) domains of the integrin ß subunits exert endogenous thiol isomerase activity derived from their two highly conserved CXXC active site motifs. Given the importance of redox reactions in integrin activation and its location in the knee region, this PSI domain activity may be critically involved in facilitating the interconversions between integrin conformations. Our monoclonal antibodies against the ß3 PSI domain inhibited its thiol isomerase activity and proportionally attenuated fibrinogen binding and platelet aggregation. Notably, these antibodies inhibited thrombosis without significantly impairing hemostasis or causing platelet clearance. In this review, we will update mechanisms of thrombosis and hemostasis, including platelet versatilities and immune-mediated thrombocytopenia, discuss critical contributions of the newly discovered PSI domain thiol isomerase activity, and its potential as a novel target for anti-thrombotic therapies and beyond.


Assuntos
Plaquetas/patologia , Hemostasia , Trombose/patologia , Animais , Plaquetas/citologia , Plaquetas/metabolismo , Moléculas de Adesão Celular/metabolismo , Humanos , Integrinas/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Ativação Plaquetária , Semaforinas/metabolismo , Trombocitopenia/sangue , Trombocitopenia/metabolismo , Trombocitopenia/patologia , Trombose/sangue , Trombose/metabolismo
12.
Int J Lab Hematol ; 40(2): 175-180, 2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29115727

RESUMO

BACKGROUND: Bleeding assessment tools have evolved in the last decade to standardize the assessment of the severity of bleeding symptom in a consistent way. In 2010, the International Society on Thrombosis and Hemostasis-Bleeding Assessment Tool (ISTH-BAT) was developed and validated. AIMS: Our aim was to administer ISTH-BAT questionnaire to the Omani patients with type 1 VWD and obtain the bleeding score (BS). We also studied the severity of their bleeding symptoms and correlated it with the BS as well as with the laboratory parameters. METHODS: Forty-eight type I VWD index cases and 52 normal subjects were interviewed and the ISTH-BAT questionnaire administered. The BS was calculated based on a history of bleeding symptoms from 12 different sites according to the standard ISTH-BAT questionnaire. Laboratory parameters were obtained from patient's medical records. RESULTS: The mean age of this cohort was 27 years (range, 6-49) with 60% being females. The median time to administer this questionnaire was 10 minutes with an interquartile range (IQR) from 8 to 17 minutes. Overall, the median BS was 7 (IQR; 2,11) although individual scores ranged between 0 and 36. The BS was negatively correlated with VWF: Ag, VWF: RCo, and VWF: CB and the Spearman's correlation coefficient "rho" was, respectively, -0.15, -0.08, and -0.22. CONCLUSION: The ISTH-BAT BS is designed to reflect the severity of bleeding. Our results demonstrate the inherent variability of this bleeding pattern. We also found that the ISTH-BAT BS significantly correlated with VWF: Ag and VWF: CB.


Assuntos
Hemorragia/diagnóstico , Doença de von Willebrand Tipo 1/complicações , Adolescente , Adulto , Criança , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Índice de Gravidade de Doença , Inquéritos e Questionários , Adulto Jovem , Fator de von Willebrand/análise
13.
J Nutr ; 147(10): 1917-1925, 2017 10.
Artigo em Inglês | MEDLINE | ID: mdl-28855423

RESUMO

Background: Platelets play an important role in hemostasis, thrombosis, and atherosclerosis. Glycoprotein VI (GPVI) is a major platelet receptor that interacts with exposed collagen on injured vessel walls. Our previous studies have shown that anthocyanins (a type of natural plant pigment) attenuate platelet function; however, whether anthocyanins affect collagen-induced GPVI signaling remains unknown.Objective: The objective of this study was to explore the effects of cyanidin-3-glucoside (Cy-3-g, one of the major bioactive compounds in anthocyanins) on platelet activation and thrombosis and the GPVI signaling pathway.Methods: Platelets from healthy men and women were isolated and incubated with different concentrations (0, 0.5, 5, and 50 µM) of Cy-3-g. The expression of activated integrin αIIbß3, P-selectin, CD63, and CD40L, fibrinogen binding to platelets, and platelet aggregation were evaluated in vitro. Platelet adhesion and aggregation in whole blood under flow conditions were assessed in collagen-coated perfusion chambers. Thrombosis and hemostasis were assessed in 3-4-wk-old male C57BL/6J mice through FeCl3-induced intravital microscopy and tail bleeding time. The effect of Cy-3-g on collagen-induced human platelet GPVI signaling was explored with Western blot.Results: Cy-3-g attenuated platelet function in a dose-dependent manner. The 0.5-µM dose of Cy-3-g inhibited (P < 0.05) human platelet adhesion and aggregation to collagen at both venous (-54.02%) and arterial (-22.90%) shear stresses. The 5-µM dose inhibited (P < 0.05) collagen-induced human platelet activation (PAC-1: -48.21%, P-selectin: -50.63%), secretion (CD63: -73.89%, CD40L: -43.70%), fibrinogen binding (-56.79%), and aggregation (-17.81%). The 5-µM dose attenuated (P < 0.01) thrombus growth (-66.67%) without prolonging bleeding time in mice. The 50-µM dose downregulated (P < 0.05) collagen-induced GPVI signaling in human platelets and significantly decreased phosphorylation of Syk-linker for activation of T cells (LAT)-SLP76 (Syk: -39.08%, LAT: -32.25%, SLP76: -40.00%) and the expression of Lyn (-31.89%), Fyn (-36.27%), and phospholipase C-γ2 (-39.08%).Conclusions: Cy-3-g inhibits human platelet activation, aggregation, secretion, and thrombus formation, and downregulates the collagen-GPVI signaling pathway. Supplementation of Cy-3-g may have protective effects against atherothrombosis.


Assuntos
Plaquetas/metabolismo , Fitoterapia , Extratos Vegetais/farmacologia , Plantas Comestíveis/química , Agregação Plaquetária/efeitos dos fármacos , Glicoproteínas da Membrana de Plaquetas/metabolismo , Trombose/prevenção & controle , Proteínas Adaptadoras de Transdução de Sinal/sangue , Adulto , Idoso , Animais , Antocianinas/farmacologia , Antocianinas/uso terapêutico , Antígenos CD/sangue , Aterosclerose/sangue , Aterosclerose/dietoterapia , Aterosclerose/etiologia , Colágeno/sangue , Feminino , Glucosídeos/farmacologia , Glucosídeos/uso terapêutico , Hemostasia/efeitos dos fármacos , Humanos , Masculino , Camundongos Endogâmicos C57BL , Pessoa de Meia-Idade , Selectina-P/sangue , Fosfoproteínas/sangue , Extratos Vegetais/uso terapêutico , Ativação Plaquetária/efeitos dos fármacos , Transdução de Sinais , Trombose/sangue , Trombose/etiologia
14.
Pharmacol Res ; 117: 283-287, 2017 03.
Artigo em Inglês | MEDLINE | ID: mdl-28065857

RESUMO

Circulating platelets participate in the process of numerous diseases including thrombosis, inflammation, and cancer. Thus, it is of great importance to understand the underlying mechanisms mediating platelet activation under disease conditions. Emerging evidence indicates that despite the lack of a nucleus, platelets possess molecules that are involved in gene transcription in nucleated cells. This review will summarize downstream regulatory element antagonist modulator (DREAM), a transcriptional repressor, and highlight recent findings suggesting its novel non-transcriptional role in hemostasis and thrombosis.


Assuntos
Fibrinolíticos/farmacologia , Fibrinolíticos/uso terapêutico , Proteínas Interatuantes com Canais de Kv/metabolismo , Trombose/tratamento farmacológico , Trombose/metabolismo , Animais , Plaquetas/efeitos dos fármacos , Plaquetas/metabolismo , Núcleo Celular/efeitos dos fármacos , Núcleo Celular/metabolismo , Humanos
15.
J Biomed Res ; 292015 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-26541706

RESUMO

Platelets are small anucleate cells generated from megakaryocytes in the bone marrow. Although platelet generation, maturation, and clearance are still not fully understood, significant progress has been made in the last 1-2 decades. In blood circulation, platelets can quickly adhere and aggregate at sites of vascular injury, forming the platelet plug (i.e. the first wave of hemostasis). Activated platelets can also provide negatively charged phosphatidylserinerich membrane surface that enhances cell-based thrombin generation, which facilitates blood coagulation (i.e. the second wave of hemostasis). Platelets therefore play central roles in hemostasis. However, the same process of hemostasis may also cause thrombosis and vessel occlusion, which are the most common mechanisms leading to heart attack and stroke following ruptured atherosclerotic lesions. In this review, we will introduce the classical mechanisms and newly discovered pathways of platelets in hemostasis and thrombosis, including fibrinogen-independent platelet aggregation and thrombosis, and the plasma fibronectin-mediated "protein wave" of hemostasis that precedes the classical first wave of hemostasis. Furthermore, we briefly discuss the roles of platelets in inflammation and atherosclerosis and the potential strategies to control atherothrombosis.

16.
Genes Dis ; 2(2): 173-185, 2015 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-28345015

RESUMO

Platelets play critical roles in hemostasis and thrombosis. Emerging evidence indicates that they are versatile cells and also involved in many other physiological processes and disease states. Fetal and neonatal alloimmune thrombocytopenia (FNAIT) is a life threatening bleeding disorder caused by fetal platelet destruction by maternal alloantibodies developed during pregnancy. Gene polymorphisms cause platelet surface protein incompatibilities between mother and fetus, and ultimately lead to maternal alloimmunization. FNAIT is the most common cause of intracranial hemorrhage in full-term infants and can also lead to intrauterine growth retardation and miscarriage. Proper diagnosis, prevention and treatment of FNAIT is challenging due to insufficient knowledge of the disease and a lack of routine screening as well as its frequent occurrence in first pregnancies. Given the ethical difficulties in performing basic research on human fetuses and neonates, animal models are essential to improve our understanding of the pathogenesis and treatment of FNAIT. The aim of this review is to provide an overview on platelets, hemostasis and thrombocytopenia with a focus on the advancements made in FNAIT by utilizing animal models.

17.
Korean J Hematol ; 45(4): 260-3, 2010 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21253428

RESUMO

BACKGROUND: An early diagnosis of disseminated intravascular coagulation (DIC) before its progression to an overt stage is necessary for early treatment and positive outcomes. In 2001, the Scientific and Standardization Committee (SCC) of the International Society on Thrombosis and Hemostasis (ISTH) proposed new criteria for the preclinical diagnosis of overt and non-overt DICs. We investigated the clinical usefulness of the modified ISTH criteria for non-overt DIC diagnosis. METHODS: We enrolled 296 DIC patients (170 males and 126 females) admitted and evaluated at the Gangnam Severance Hospital, Seoul, Korea, between March 2006 and April 2007. Hemostatic tests, including platelet counts, prothrombin time (PT), D-dimer levels with antithrombin, and protein-C levels, were evaluated by excluding negative scores with clinical signs, in which more than 5 points of interest denoted non-overt DIC. Mortality rates were also evaluated. RESULTS: There were 289 patients with increased D-dimer levels and significant parametric changes suggesting DIC progression. Protein C and antithrombin levels were lower (99.2% each) and appeared earlier in patients with non-overt DIC than in patients with overt DIC. In all, 125 (43.3%) patients had non-overt DIC and, of which 27 died (mortality rate, 21.6%). The sensitivity and specificity for mortality were 73.0% and 55.9%, respectively, which were same as those for the original ISTH criteria. CONCLUSION: The modified ISTH criteria can be used for the early detection of non-overt DIC, and may be useful for the improvement of outcomes of non-overt DIC patients.

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