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1.
Sci Rep ; 11(1): 5190, 2021 03 04.
Artigo em Inglês | MEDLINE | ID: mdl-33664450

RESUMO

In Coronavirus disease 2019 (COVID-19) subjects, recent evidence suggests the presence of unique coagulation abnormalities. In this study, we performed clot waveform analyses to investigate whether specific modulations are observed in COVID-19 subjects. We analyzed the second derivative of the absorbance in routine APTT tests performed using an ACL-TOP system. We observed high frequencies of abnormal patterns in APTT second-derivative curves that could be classified into an early shoulder type, a late shoulder type, or a biphasic type, high maximum first-derivative and second-derivative peak levels, and a low minimum second-derivative peak level in COVID-19 subjects. These modulations were not observed in subjects with disseminated intravascular coagulation. These abnormal patterns are also observed in patients with lupus anticoagulant, hemophilia, or factor IX deficiency. The plasma fibrinogen levels might also be involved in the abnormal APTT waveforms, especially the high maximum first-derivative and second-derivative peak levels. The abnormal patterns in the APTT second-derivative curves appear with highest frequency at around 2 weeks after the onset of COVID-19 and were not associated with the severity of COVID-19. These results suggest the possible presence of a specific abnormal coagulopathy in COVID-19.


Assuntos
Coagulação Sanguínea , /sangue , Idoso , Testes de Coagulação Sanguínea , Feminino , Fibrinogênio/metabolismo , Humanos , Masculino , Pessoa de Meia-Idade , Compostos Organometálicos , Triazóis
2.
Medicine (Baltimore) ; 100(9): e24978, 2021 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-33655967

RESUMO

RATIONALE: Severe hypofibrinogenemia after intravenous thrombolysis (IVT) with recombinant tissue plasminogen activator (rt-PA) is rare and easily overlooked, but hypofibrinogenemia increases the risk of major bleeding. However, it is unclear when hypofibrinogenemia reaches the peak and when hypofibrinogenemia is resolved. PATIENT CONCERNS: Case 1 was of a 66-year-old man who was hospitalized due to sudden onset of vague speech and right hemiplegia for 4 hours. Case 2 was of an 84-year-old woman who was hospitalized for sudden onset of left hemiplegia and vague speech for 4 hours. In case 1, fibrinogen levels decreased from normal values to <0.25 g/L within 4.5 hours after commencing IVT and returned to normal at 35 hours later. In case 2, fibrinogen levels decreased from 1.1 to <0.25 g/L within 2 hours after commencing IVT and normalized 36.5 hours later. DIAGNOSES: Both patients were diagnosed with rt-PA-related hypofibrinogenemia. INTERVENTIONS: No antiplatelet or symptomatic treatment was administered during the period of hypofibrinogenemia. OUTCOMES: Fibrinogen levels gradually recovered. In case 1, the patient did not experience cerebral hemorrhage during hypofibrinogenemia. His symptoms improved significantly within 1 week. In case 2, repeat computed tomography revealed minor cerebral hemorrhage, but no deterioration in her condition was noted until she was discharged. LESSONS: Rapid, severe, and prolonged hypofibrinogenemia may occur after IVT with rt-PA, which may increase the risk of massive hemorrhage and affect the related therapy. Prompt diagnosis of hypofibrinogenemia is important for preventing complications. We recommend checking the fibrinogen levels routinely after IVT. Fibrinogen replacement therapy and platelet transfusion are the main management routes for rt-PA-related symptomatic intracranial hemorrhage.


Assuntos
Afibrinogenemia/induzido quimicamente , Fibrinogênio/metabolismo , Acidente Vascular Cerebral/tratamento farmacológico , Terapia Trombolítica/efeitos adversos , Ativador de Plasminogênio Tecidual/efeitos adversos , Afibrinogenemia/sangue , Idoso , Idoso de 80 Anos ou mais , Biomarcadores/sangue , Feminino , Fibrinolíticos/efeitos adversos , Humanos , Masculino , Doenças Raras , Índice de Gravidade de Doença
3.
Am J Pathol ; 191(3): 575-583, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33608067

RESUMO

Central nervous system (CNS) lymphoma is an extranodal non-Hodgkin B-cell lymphoma characterized by malignant lymph tissue arising in the brain or spinal cord, associated with inflammation and blood-brain barrier (BBB) disruption. Although BBB disruption is known to occur in patients with CNS lymphoma, a direct link between these two has not been shown. Herein, abundant deposition of the blood coagulation protein fibrinogen around B-cell lymphoma was detected in CNS lymphoma patients and in the CNS parenchyma in an orthotopic mouse model. Functional enrichment analysis of unbiased cerebrospinal fluid proteomics of CNS B-cell lymphoma patients showed that coagulation protein networks were highly connected with tumor-associated biological signaling pathways. In vivo two-photon imaging demonstrated that lymphoma growth was associated with BBB disruption, and in vitro experiments identified a role for fibrinogen in promoting lymphoma cell adhesion. Overall, these results identify perivascular lymphoma clustering at sites of fibrinogen deposition, and suggest that fibrinogen may be a target for pharmacologic intervention in metastatic B-cell lymphoma associated with BBB disruption.


Assuntos
Adesão Celular , Neoplasias do Sistema Nervoso Central/patologia , Fibrinogênio/metabolismo , Inflamação/patologia , Linfócitos/patologia , Linfoma de Células B/patologia , Animais , Transporte Biológico , Neoplasias do Sistema Nervoso Central/etiologia , Neoplasias do Sistema Nervoso Central/metabolismo , Modelos Animais de Doenças , Fibrinogênio/genética , Humanos , Inflamação/etiologia , Inflamação/metabolismo , Linfócitos/metabolismo , Linfoma de Células B/etiologia , Linfoma de Células B/metabolismo , Masculino , Camundongos , Camundongos Nus
4.
Int J Mol Sci ; 22(2)2021 Jan 11.
Artigo em Inglês | MEDLINE | ID: mdl-33440782

RESUMO

Venous thrombosis occurs in patients with quantitative and qualitative fibrinogen disorders. Injury-induced thrombosis in zebrafish larvae has been used to model human coagulopathies. We aimed to determine whether zebrafish models of afibrinogenemia and dysfibrinogenemia have different thrombotic phenotypes. Laser injuries were used to induce venous thrombosis and the time-to-occlusion (TTO) and the binding and aggregation of fluorescent Tg(itga2b:EGFP) thrombocytes measured. The fga-/- larvae failed to support occlusive venous thrombosis and showed reduced thrombocyte binding and aggregation at injury sites. The fga+/- larvae were largely unaffected. When genome editing zebrafish to produce fibrinogen Aα R28C, equivalent to the human Aα R35C dysfibrinogenemia mutation, we detected in-frame skipping of exon 2 in the fga mRNA, thereby encoding AαΔ19-56. This mutation is similar to Fibrinogen Montpellier II which causes hypodysfibrinogenemia. Aα+/Δ19-56 fish had prolonged TTO and reduced thrombocyte activity, a dominant effect of the mutation. Finally, we used transgenic expression of fga R28C cDNA in fga knock-down or fga-/- mutants to model thrombosis in dysfibrinogenemia. Aα R28C expression had similar effects on TTO and thrombocyte activity as Aα+/Δ19-56. We conclude that thrombosis assays in larval zebrafish can distinguish between quantitative and qualitative fibrinogen disorder models and may assist in anticipating a thrombotic phenotype of novel fibrinogen mutations.


Assuntos
Biomarcadores , Plaquetas/metabolismo , Fibrinogênio/metabolismo , Trombose Venosa/sangue , Trombose Venosa/etiologia , Animais , Sequência de Bases , Coagulação Sanguínea , Modelos Animais de Doenças , Éxons , Fibrinogênio/química , Fibrinogênio/genética , Edição de Genes , Expressão Gênica , Plasmídeos/genética , Ativação Plaquetária , RNA Guia , Deleção de Sequência , Trombose Venosa/diagnóstico , Peixe-Zebra
5.
Arterioscler Thromb Vasc Biol ; 41(3): 1092-1104, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33472402

RESUMO

OBJECTIVE: GPVI (glycoprotein VI) is a key molecular player in collagen-induced platelet signaling and aggregation. Recent evidence indicates that it also plays important role in platelet aggregation and thrombus growth through interaction with fibrin(ogen). However, there are discrepancies in the literature regarding whether the monomeric or dimeric form of GPVI binds to fibrinogen at high affinity. The mechanisms of interaction are also not clear, including which region of fibrinogen is responsible for GPVI binding. We aimed to gain further understanding of the mechanisms of interaction at molecular level and to identify the regions on fibrinogen important for GPVI binding. Approach and Results: Using multiple surface- and solution-based protein-protein interaction methods, we observe that dimeric GPVI binds to fibrinogen with much higher affinity and has a slower dissociation rate constant than the monomer due to avidity effects. Moreover, our data show that the highest affinity interaction of GPVI is with the αC-region of fibrinogen. We further show that GPVI interacts with immobilized fibrinogen and fibrin variants at a similar level, including a nonpolymerizing fibrin variant, suggesting that GPVI binding is independent of fibrin polymerization. CONCLUSIONS: Based on the above findings, we conclude that the higher affinity of dimeric GPVI over the monomer for fibrinogen interaction is achieved by avidity. The αC-region of fibrinogen appears essential for GPVI binding. We propose that fibrin polymerization into fibers during coagulation will cluster GPVI through its αC-region, leading to downstream signaling, further activation of platelets, and potentially stimulating clot growth. Graphic Abstract: A graphic abstract is available for this article.


Assuntos
Fibrinogênio/metabolismo , Fragmentos de Peptídeos/sangue , Glicoproteínas da Membrana de Plaquetas/metabolismo , Animais , Proteínas de Transporte/química , Proteínas de Transporte/metabolismo , Produtos de Degradação da Fibrina e do Fibrinogênio/química , Produtos de Degradação da Fibrina e do Fibrinogênio/metabolismo , Fibrinogênio/química , Humanos , Técnicas In Vitro , Camundongos , Microscopia de Força Atômica , Fragmentos de Peptídeos/química , Peptídeos/química , Peptídeos/metabolismo , Agregação Plaquetária/fisiologia , Glicoproteínas da Membrana de Plaquetas/química , Domínios e Motivos de Interação entre Proteínas , Estrutura Quaternária de Proteína , Transdução de Sinais , Ressonância de Plasmônio de Superfície
6.
Methods Mol Biol ; 2217: 237-249, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33215384

RESUMO

Platelets are small, anucleate cells that play oversized roles in hemostasis, immunity, and inflammation. An important mediator of platelet function is integrin αIIbß3, which is required for fibrinogen-dependent platelet aggregation during hemostasis. This platelet response is dependent on conformational changes in the integrin induced by "inside-out" biochemical signals that are triggered by platelet agonists. In turn, fibrinogen binding to αIIbß3 initiates "outside-in" biochemical and mechanical signals that regulate the platelet cytoskeleton and help to promote full platelet aggregation and secretory responses. Without a nucleus, there is a limited range of experimental manipulations that are possible with human platelets to study the molecular basis of integrin signaling in these primary cells. Consequently, many studies of αIIbß3 function use genetic approaches that rely on heterologous expression systems or platelets from gene-targeted mice, sometimes with uncertain applicability to human platelets. This chapter will detail a method for genetic manipulation of megakaryocytes and platelets derived from human induced pluripotent stem cells for molecular studies of αIIbß3 signaling and for modeling of human platelet functions potentially relevant to hemostasis, immunity, and inflammation.


Assuntos
Plaquetas/metabolismo , Engenharia Celular/métodos , Megacariócitos/metabolismo , Agregação Plaquetária/genética , Complexo Glicoproteico GPIIb-IIIa de Plaquetas/genética , Complexo Glicoproteico GPIb-IX de Plaquetas/genética , Glicoproteína IIb da Membrana de Plaquetas/genética , Plaquetas/citologia , Diferenciação Celular , Linhagem Celular , Citoesqueleto/metabolismo , Citoesqueleto/ultraestrutura , Fibrinogênio/genética , Fibrinogênio/metabolismo , Regulação da Expressão Gênica , Hemostasia/genética , Humanos , Células-Tronco Pluripotentes Induzidas/citologia , Células-Tronco Pluripotentes Induzidas/metabolismo , Megacariócitos/citologia , Complexo Glicoproteico GPIIb-IIIa de Plaquetas/metabolismo , Complexo Glicoproteico GPIb-IX de Plaquetas/metabolismo , Glicoproteína IIb da Membrana de Plaquetas/metabolismo , Ligação Proteica , RNA Interferente Pequeno/genética , RNA Interferente Pequeno/metabolismo , Transdução de Sinais , Ubiquitinas/antagonistas & inibidores , Ubiquitinas/genética , Ubiquitinas/metabolismo
7.
Cardiol Rev ; 29(1): 43-47, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-32947478

RESUMO

The novel coronavirus (severe acute respiratory syndrome CoV-2 [SARS-CoV-2]), also known as COVID-19, is a single-stranded enveloped RNA virus that created a Public Health Emergency of International Concern in January 2020, with a global case burden of over 15 million in just 7 months. Infected patients develop a wide range of clinical manifestations-typically presenting with fever, cough, myalgia, and fatigue. Severely ill patients may fall victim to acute respiratory distress syndrome, acute heart injuries, neurological manifestations, or complications due to secondary infections. These critically ill patients are also found to have disrupted coagulation function, predisposing them to consumptive coagulopathies, and both venous and thromboembolic complications. Common laboratory findings include thrombocytopenia, elevated D-dimer, fibrin degradation products, and fibrinogen, all of which have been associated with greater disease severity. Many cases of pulmonary embolism have been noted, along with deep vein thrombosis, ischemic stroke, myocardial infarction, and systemic arterial embolism. The pathogenesis of coronavirus has not been completely elucidated, but the virus is known to cause excessive inflammation, endothelial injury, hypoxia, and disseminated intravascular coagulation, all of which contribute to thrombosis formation. These patients are also faced with prolonged immobilization while staying in the hospital or intensive care unit. It is important to have a high degree of suspicion for thrombotic complications as patients may rapidly deteriorate in severe cases. Evidence suggests that prophylaxis with anticoagulation may lead to a lower risk of mortality, although it does not eliminate the possibility. The risks and benefits of anticoagulation treatment should be considered in each case. Patients should be regularly evaluated for bleeding risks and thrombotic complications.


Assuntos
Transtornos da Coagulação Sanguínea/sangue , Embolia/sangue , Trombose/sangue , Anticoagulantes/uso terapêutico , Transtornos da Coagulação Sanguínea/tratamento farmacológico , Transtornos da Coagulação Sanguínea/etiologia , Transtornos da Coagulação Sanguínea/metabolismo , /tratamento farmacológico , Síndrome da Liberação de Citocina/sangue , Síndrome da Liberação de Citocina/complicações , Síndrome da Liberação de Citocina/metabolismo , Coagulação Intravascular Disseminada/sangue , Coagulação Intravascular Disseminada/etiologia , Coagulação Intravascular Disseminada/metabolismo , Coagulação Intravascular Disseminada/prevenção & controle , Embolia/etiologia , Embolia/metabolismo , Embolia/prevenção & controle , Endotélio Vascular/metabolismo , Produtos de Degradação da Fibrina e do Fibrinogênio/metabolismo , Fibrinogênio/metabolismo , Humanos , Hipóxia/sangue , Hipóxia/etiologia , Hipóxia/metabolismo , Imobilização , Inflamação/sangue , Inflamação/etiologia , Inflamação/metabolismo , /etiologia , /prevenção & controle , Infarto do Miocárdio/sangue , Infarto do Miocárdio/etiologia , Infarto do Miocárdio/metabolismo , Infarto do Miocárdio/prevenção & controle , Guias de Prática Clínica como Assunto , Embolia Pulmonar/sangue , Embolia Pulmonar/etiologia , Embolia Pulmonar/metabolismo , Embolia Pulmonar/prevenção & controle , Índice de Gravidade de Doença , Trombocitopenia/sangue , Trombocitopenia/etiologia , Trombose/etiologia , Trombose/metabolismo , Trombose/prevenção & controle , Trombose Venosa/sangue , Trombose Venosa/etiologia , Trombose Venosa/metabolismo
8.
Food Chem ; 334: 127507, 2021 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-32688180

RESUMO

A novel food-derived anticoagulant heptapeptides (P-3-CG) was isolated and characterized from oyster (Crassostrea gigas) pepsin hydrolysate. P-3-CG competed with fibrinogen against thrombin active domain by a spontaneous and exothermic reaction which was entropically driven. The residue Lys7 of P-3-CG anchored thrombin S1 pocket strongly, which inhibited fibrinogen binding to the thrombin, then blocked the conversion of fibrinogen to fibrin. The fibrinogen clotting time was prolonged to 27.55 s, and the reciprocally authenticated results of dynamic light scattering and scanning electron microscope further explained for fibrinogen clotting time extension. Inhibition of amidolytic activity of thrombin was affected significantly by reaction time and P-3-CG concentration. Furthermore, P-3-CG prolonged activated partial thromboplastin time significantly in vitro/vivo, and decreased the mortality which was confirmed by pulmonary pathological slide results. The obtained results demonstrated that P-3-CG may potentially serve as an alternative food-derived anticoagulant peptide that could be utilized for thrombosis prevention.


Assuntos
Anticoagulantes/metabolismo , Crassostrea/metabolismo , Oligopeptídeos/metabolismo , Trombina/metabolismo , Animais , Anticoagulantes/química , Fibrinogênio/metabolismo , Humanos , Hidrólise , Oligopeptídeos/química , Pepsina A/metabolismo , Trombina/química
9.
Blood ; 136(26): 3062-3069, 2020 12 24.
Artigo em Inglês | MEDLINE | ID: mdl-33367543

RESUMO

Fibrinogen is a key component of the coagulation cascade, and variation in its circulating levels may contribute to thrombotic diseases, such as venous thromboembolism (VTE) and ischemic stroke. Gamma prime (γ') fibrinogen is an isoform of fibrinogen that has anticoagulant properties. We applied 2-sample Mendelian randomization (MR) to estimate the causal effect of total circulating fibrinogen and its isoform, γ' fibrinogen, on risk of VTE and ischemic stroke subtypes using summary statistics from genome-wide association studies. Genetic instruments for γ' fibrinogen and total fibrinogen were selected, and the inverse-variance weighted MR approach was used to estimate causal effects in the main analysis, complemented by sensitivity analyses that are more robust to the inclusion of pleiotropic variants, including MR-Egger, weighted median MR, and weighted mode MR. The main inverse-variance weighted MR estimates based on a combination of 16 genetic instruments for γ' fibrinogen and 75 genetic instruments for total fibrinogen indicated a protective effect of higher γ' fibrinogen and higher total fibrinogen on VTE risk. There was also a protective effect of higher γ' fibrinogen levels on cardioembolic and large artery stroke risk. Effect estimates were consistent across sensitivity analyses. Our results provide evidence to support effects of genetically determined γ' fibrinogen on VTE and ischemic stroke risk. Further research is needed to explore mechanisms underlying these effects and their clinical applications.


Assuntos
Fibrinogênio , Variação Genética , Análise da Randomização Mendeliana , Tromboembolia Venosa , Feminino , Fibrinogênio/genética , Fibrinogênio/metabolismo , Estudo de Associação Genômica Ampla , Humanos , /epidemiologia , Masculino , Fatores de Risco , Tromboembolia Venosa/sangue , Tromboembolia Venosa/epidemiologia , Tromboembolia Venosa/genética
10.
Int J Mol Sci ; 21(24)2020 Dec 11.
Artigo em Inglês | MEDLINE | ID: mdl-33322373

RESUMO

Rheumatoid arthritis (RA) is an autoimmune disease associated with thrombotic complications. To elucidate pathogenic mechanisms, hemostatic disorders in RA were correlated with other laboratory and clinical manifestations. Hemostasis was assessed using relatively new complementary tests, the spatial growth of a plasma clot (Thrombodynamics assay), and contraction of whole blood clots. Platelet functionality was assessed with flow cytometry that quantified the expression of P-selectin and the fibrinogen-binding capacity of platelets before and after activation with a thrombin receptor-activating peptide. Parameters of fibrin clot growth and the kinetics of contraction of blood clots were significantly altered in patients with RA compared to the control group. In Thrombodynamics measurements, an increase in the clot growth rate, size, and optical density of plasma clots altogether indicated chronic hypercoagulability. The rate and extent of blood clot contraction in patients with RA was significantly reduced and associated with platelet dysfunction revealed by an impaired response to activation. Changes in the parameters of clot growth and contraction correlated with the laboratory signs of systemic inflammation, including hyperfibrinogenemia. These results confirm the pathogenic role of hemostatic disorders in RA and support the validity of fibrin clot growth and the blood clot contraction assay as indicators of a (pro)thrombotic state.


Assuntos
Artrite Reumatoide/metabolismo , Artrite Reumatoide/patologia , Fibrina/metabolismo , Trombose/metabolismo , Trombose/patologia , Adulto , Idoso , Coagulação Sanguínea/fisiologia , Feminino , Fibrinogênio/metabolismo , Humanos , Masculino , Pessoa de Meia-Idade , Selectina-P/metabolismo , Adulto Jovem
11.
Int J Mol Sci ; 21(24)2020 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-33322044

RESUMO

We identified a novel heterozygous variant, Bßp.Pro234Leu (fibrinogen Tokorozawa), which was suspected to be associated with hypofibrinogenemia. Therefore, we analyzed the assembly and secretion of this fibrinogen using Chinese hamster ovary (CHO) cells. To determine the impact on the synthesis and secretion of fibrinogen of the Bßp.P234L and γp.G242E substitutions, we established recombinant variant fibrinogen-producing CHO cell lines. Synthesis and secretion analyses were performed using an enzyme-linked immunosorbent assay (ELISA) and immunoblotting analysis with the established cell lines. In addition, we performed fibrin polymerization using purified plasma fibrinogen and in-silico analysis. Both Bßp.P234L and γp.G242E impaired the secretion and synthesis of fibrinogen. Moreover, immunoblotting analysis elucidated the mobility migration of the Bßγ complex in Bßp.P234L. On the other hand, the fibrin polymerization of fibrinogen Tokorozawa was similar to that of normal fibrinogen. In-silico analysis revealed that the Bßp.P234 residue is located in the contact region between the Bß and γ chains and contacts γp.G242 residue. The present study demonstrated that the Bßp.P234L substitution resulted in hypofibrinogenemia by decreasing the assembly and secretion of fibrinogen. Therefore, there is a possibility that substitutions in the contact region between the Bß and γ chains impact the assembly and secretion of fibrinogen.


Assuntos
Afibrinogenemia/genética , Fibrinogênio/genética , Multimerização Proteica , Substituição de Aminoácidos , Animais , Células CHO , Cricetinae , Cricetulus , Fibrinogênio/química , Fibrinogênio/metabolismo , Humanos , Transporte Proteico
12.
Eur Rev Med Pharmacol Sci ; 24(23): 12466-12479, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-33336766

RESUMO

OBJECTIVE: Severe Acute Respiratory Syndrome Coronavirus (SARS-CoV-2) infection may yield a hypercoagulable state with fibrinolysis impairment. We conducted a single-center observational study with the aim of analyzing the coagulation patterns of intensive care unit (ICU) COVID-19 patients with both standard laboratory and viscoelastic tests. The presence of coagulopathy at the onset of the infection and after seven days of systemic anticoagulant therapy was investigated. PATIENTS AND METHODS: Forty consecutive SARS-CoV-2 patients, admitted to the ICU of a University hospital in Italy between 29th February and 30th March 2020 were enrolled in the study, providing they fulfilled the acute respiratory distress syndrome criteria. They received full-dose anticoagulation, including Enoxaparin 0.5 mg·kg-1 subcutaneously twice a day, unfractionated Heparin 7500 units subcutaneously three times daily, or low-intensity Heparin infusion. Thromboelastographic (TEG) and laboratory parameters were measured at admission and after seven days. RESULTS: At baseline, patients showed elevated fibrinogen activity [rTEG-Ang 80.5° (78.7 to 81.5); TEG-ACT 78.5 sec (69.2 to 87.9)] and an increase in the maximum amplitude of clot strength [FF-MA 42.2 mm (30.9 to 49.2)]. No alterations in time of the enzymatic phase of coagulation [CKH-K and CKH-R, 1.1 min (0.85 to 1.3) and 6.6 min (5.2 to 7.5), respectively] were observed. Absent lysis of the clot at 30 minutes (LY30) was observed in all the studied population. Standard coagulation parameters were within the physiological range: [INR 1.09 (1.01 to 1.20), aPTT 34.5 sec (29.7 to 42.2), antithrombin 97.5% (89.5 to 115)]. However, plasma fibrinogen [512.5 mg·dl-1 (303.5 to 605)], and D-dimer levels [1752.5 ng·ml-1 (698.5 to 4434.5)], were persistently increased above the reference range. After seven days of full-dose anticoagulation, average TEG parameters were not different from baseline (rTEG-Ang p = 0.13, TEG-ACT p = 0.58, FF-MA p = 0.24, CK-R p = 0.19, CKH-R p  = 0.35), and a persistent increase in white blood cell count, platelet count and D-dimer was observed (white blood cell count p < 0.01, neutrophil count p = 0.02, lymphocyte count p < 0.01, platelet count p = 0.13 < 0.01, D-dimer levels p= 0.02). CONCLUSIONS: SARS-CoV-2 patients with acute respiratory distress syndrome show elevated fibrinogen activity, high D-dimer levels and maximum amplitude of clot strength. Platelet count, fibrinogen, and standard coagulation tests do not indicate a disseminated intravascular coagulation. At seven days, thromboelastographic abnormalities persist despite full-dose anticoagulation.


Assuntos
Anticoagulantes/uso terapêutico , Transtornos da Coagulação Sanguínea/sangue , /sangue , Tromboelastografia , Idoso , Idoso de 80 Anos ou mais , Antitrombinas/sangue , Transtornos da Coagulação Sanguínea/tratamento farmacológico , Testes de Coagulação Sanguínea , Enoxaparina/uso terapêutico , Feminino , Produtos de Degradação da Fibrina e do Fibrinogênio/metabolismo , Fibrinogênio/metabolismo , Heparina/uso terapêutico , Humanos , Coeficiente Internacional Normatizado , Contagem de Leucócitos , Contagem de Linfócitos , Masculino , Pessoa de Meia-Idade , Neutrófilos , Tempo de Tromboplastina Parcial , Contagem de Plaquetas , Estudos Prospectivos , Resultado do Tratamento
13.
Nat Commun ; 11(1): 5778, 2020 11 13.
Artigo em Inglês | MEDLINE | ID: mdl-33188196

RESUMO

Breakdown of vascular barriers is a major complication of inflammatory diseases. Anucleate platelets form blood-clots during thrombosis, but also play a crucial role in inflammation. While spatio-temporal dynamics of clot formation are well characterized, the cell-biological mechanisms of platelet recruitment to inflammatory micro-environments remain incompletely understood. Here we identify Arp2/3-dependent lamellipodia formation as a prominent morphological feature of immune-responsive platelets. Platelets use lamellipodia to scan for fibrin(ogen) deposited on the inflamed vasculature and to directionally spread, to polarize and to govern haptotactic migration along gradients of the adhesive ligand. Platelet-specific abrogation of Arp2/3 interferes with haptotactic repositioning of platelets to microlesions, thus impairing vascular sealing and provoking inflammatory microbleeding. During infection, haptotaxis promotes capture of bacteria and prevents hematogenic dissemination, rendering platelets gate-keepers of the inflamed microvasculature. Consequently, these findings identify haptotaxis as a key effector function of immune-responsive platelets.


Assuntos
Plaquetas/patologia , Vasos Sanguíneos/patologia , Quimiotaxia , Inflamação/patologia , Pneumonia/sangue , Complexo 2-3 de Proteínas Relacionadas à Actina/metabolismo , Adulto , Animais , Movimento Celular , Microambiente Celular , Modelos Animais de Doenças , Fibrinogênio/metabolismo , Humanos , Lipopolissacarídeos , Lesão Pulmonar/microbiologia , Lesão Pulmonar/patologia , Staphylococcus aureus Resistente à Meticilina/fisiologia , Camundongos Endogâmicos C57BL , Microvasos/patologia , Pneumonia/microbiologia , Pseudópodes/metabolismo
14.
Nat Commun ; 11(1): 5431, 2020 10 27.
Artigo em Inglês | MEDLINE | ID: mdl-33110079

RESUMO

Physical forces have profound effects on cellular behavior, physiology, and disease. Perhaps the most intruiguing and fascinating example is the formation of catch-bonds that strengthen cellular adhesion under shear stresses. Today mannose-binding by the Escherichia coli FimH adhesin remains one of the rare microbial catch-bond thoroughly characterized at the molecular level. Here we provide a quantitative demonstration of a catch-bond in living Gram-positive pathogens using force-clamp spectroscopy. We show that the dock, lock, and latch interaction between staphylococcal surface protein SpsD and fibrinogen is strong, and exhibits an unusual catch-slip transition. The bond lifetime first grows with force, but ultimately decreases to behave as a slip bond beyond a critical force (~1 nN) that is orders of magnitude higher than for previously investigated complexes. This catch-bond, never reported for a staphylococcal adhesin, provides the pathogen with a mechanism to tightly control its adhesive function during colonization and infection.


Assuntos
Adesinas Bacterianas/química , Infecções Estafilocócicas/microbiologia , Staphylococcus/metabolismo , Adesinas Bacterianas/genética , Adesinas Bacterianas/metabolismo , Aderência Bacteriana , Fibrinogênio/química , Fibrinogênio/metabolismo , Humanos , Ligação Proteica , Análise Espectral , Infecções Estafilocócicas/metabolismo , Staphylococcus/química , Staphylococcus/genética , Staphylococcus/crescimento & desenvolvimento
15.
Medicine (Baltimore) ; 99(39): e22424, 2020 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-32991476

RESUMO

Hypercoagulable is an important pathological state in anti-neutrophil cytoplasmic antibody-associated vasculitis (AAV). Fibrinogen (FIB) is the main protein in coagulation process. In this study, we aimed to investigate the clinical significance and influencing factors of FIB in AAV from Southwest China.A retrospective study was performed on AAV patients from Peoples Hospital of Deyang City from January 2007 to December 2018. Demographic and clinical characteristics were collected.A total of 463 AAV patients were included. In Wilcoxon rank sum test, FIB was significantly higher in AAV active group than inactive group (P = .005). FIB was also higher in bacterial infection group than in non-infection group both in active group (P = .008) and inactive group (P = .017). In receiver operating characteristic (ROC) curve analysis, the critical value of FIB for diagnosis of bacterial infection between AAV active and inactive groups was 3.385 g/L (P = .030), with sensitivity of 70.2% and specificity of 52.9%. In the multivariate analysis of variance (MANOVA), estimated glomerular filtration rate (eGFR) was shown to be an independent factor for FIB (P = .001). Least-significant difference showed the concentration of FIB (P < .05) increased with renal impairment, especially in endstage kidney disease (ESKD).FIB identified a certain reference value in distinguishing AAV activity from bacterial infection. ESKD had a statistical effect on it. Influencing factors of FIB should be evaluated based on the renal function impairment of patients.


Assuntos
Vasculite Associada a Anticorpo Anticitoplasma de Neutrófilos/sangue , Infecções Bacterianas/sangue , Fibrinogênio/metabolismo , Adulto , Idoso , Vasculite Associada a Anticorpo Anticitoplasma de Neutrófilos/complicações , Vasculite Associada a Anticorpo Anticitoplasma de Neutrófilos/epidemiologia , Infecções Bacterianas/complicações , China/epidemiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos
17.
Elife ; 92020 08 17.
Artigo em Inglês | MEDLINE | ID: mdl-32804081

RESUMO

Temporal inference from laboratory testing results and triangulation with clinical outcomes extracted from unstructured electronic health record (EHR) provider notes is integral to advancing precision medicine. Here, we studied 246 SARS-CoV-2 PCR-positive (COVIDpos) patients and propensity-matched 2460 SARS-CoV-2 PCR-negative (COVIDneg) patients subjected to around 700,000 lab tests cumulatively across 194 assays. Compared to COVIDneg patients at the time of diagnostic testing, COVIDpos patients tended to have higher plasma fibrinogen levels and lower platelet counts. However, as the infection evolves, COVIDpos patients distinctively show declining fibrinogen, increasing platelet counts, and lower white blood cell counts. Augmented curation of EHRs suggests that only a minority of COVIDpos patients develop thromboembolism, and rarely, disseminated intravascular coagulopathy (DIC), with patients generally not displaying platelet reductions typical of consumptive coagulopathies. These temporal trends provide fine-grained resolution into COVID-19 associated coagulopathy (CAC) and set the stage for personalizing thromboprophylaxis.


Assuntos
Betacoronavirus/isolamento & purificação , Transtornos da Coagulação Sanguínea/diagnóstico , Testes de Coagulação Sanguínea , Coagulação Sanguínea , Técnicas de Laboratório Clínico , Infecções por Coronavirus/diagnóstico , Pneumonia Viral/diagnóstico , Idoso , Betacoronavirus/patogenicidade , Biomarcadores/sangue , Transtornos da Coagulação Sanguínea/sangue , Transtornos da Coagulação Sanguínea/virologia , Infecções por Coronavirus/sangue , Infecções por Coronavirus/virologia , Progressão da Doença , Feminino , Fibrinogênio/metabolismo , Interações entre Hospedeiro e Microrganismos , Humanos , Contagem de Leucócitos , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Pandemias , Contagem de Plaquetas , Pneumonia Viral/sangue , Pneumonia Viral/virologia , Valor Preditivo dos Testes , Reprodutibilidade dos Testes , Estudos Retrospectivos , Fatores de Tempo
19.
Biomolecules ; 10(8)2020 08 09.
Artigo em Inglês | MEDLINE | ID: mdl-32784866

RESUMO

Glycosylation may strongly affect protein structure and functions. A high risk of cardiovascular complications seen in patients with end-stage renal disease (ESRD) is, at least partly associated with delayed clot formation, increased clot strength, and delayed cloth lysis. Taking into consideration that fibrinogen mediates these processes, we isolated fibrinogen from the plasma from patients with ESRD on peritoneal dialysis (ESRD-PD), and examined glycosylation of native fibrinogen and its subunits by lectin-based microarray and lectin blotting. Compared to healthy controls, fibrinogen from patients had increased levels of A2BG2 and decreased levels of FA2 glycan. The distribution of glycans on individual chains was also affected, with the γ chain, responsible for physiological functions of fibrinogen (such as coagulation and platelet aggregation), being most prone to these alterations. Increased levels of multi-antennary N-glycans in ESRD-PD patients were also associated with the type of dialysis solutions, whereas an increase in the fucosylation levels was strongly related to the peritoneal membrane damage. Consequently, investigation of fibrinogen glycans can offer better insight into fibrinogen-related complications observed in ESRD-PD patients and, additionally, contribute to prognosis, choice of personalised therapy, determination of peritoneal membrane damage, and the length of utilization of peritoneum for dialysis.


Assuntos
Fibrinogênio/química , Fibrinogênio/metabolismo , Fucose/metabolismo , Falência Renal Crônica/sangue , Diálise Peritoneal , Idoso , Idoso de 80 Anos ou mais , Biomarcadores/sangue , Feminino , Glicosilação , Humanos , Falência Renal Crônica/metabolismo , Falência Renal Crônica/patologia , Lectinas/sangue , Lectinas/química , Masculino , Pessoa de Meia-Idade , Polissacarídeos/sangue , Polissacarídeos/química , Polissacarídeos/metabolismo , Prognóstico , Análise Serial de Proteínas
20.
J Am Heart Assoc ; 9(19): e016796, 2020 10 20.
Artigo em Inglês | MEDLINE | ID: mdl-32794415

RESUMO

Background The coronavirus disease 2019 (COVID-19) has developed into a global outbreak. Patients with cardiovascular disease (CVD) with COVID-19 have different clinical characteristics and prognostic outcomes. This study aimed to summarize the clinical characteristics and laboratory indicators of patients with COVID-19 with CVD, especially the critically ill patients. Methods and Results This study included 244 patients diagnosed with COVID-19 and CVD (hypertension, coronary heart disease, or heart failure). The patients were categorized into critical (n=36) and noncritical (n=208) groups according to the interim guidance of China's National Health Commission. Clinical, laboratory, and outcome data were collected from the patients' medical records and compared between the 2 groups. The average body mass index of patients was significantly higher in the critical group than in the noncritical group. Neutrophil/lymphocyte ratio, and C-reactive protein, procalcitonin, and fibrinogen, and d-dimer levels at admission were significantly increased in the critical group. The all-cause mortality rate among cases of COVID-19 combined with CVD was 19.26%; the proportion of coronary heart disease and heart failure was significantly higher in deceased patients than in recovered patients. High body mass index, previous history of coronary heart disease, lactic acid accumulation, and a decrease in the partial pressure of oxygen were associated with death. Conclusions All-cause mortality in patients with COVID-19 with CVD in hospitals is high. The high neutrophil/lymphocyte ratio may be a predictor of critical patients. Overweight/obesity combined with coronary heart disease, severe hypoxia, and lactic acid accumulation resulting from respiratory failure are related to poor outcomes. Registration URL: https://www.chictr.org.cn; Unique identifier: ChiCTR2000029865.


Assuntos
Betacoronavirus , Doenças Cardiovasculares/epidemiologia , Infecções por Coronavirus/epidemiologia , Pneumonia Viral/epidemiologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Biomarcadores/sangue , Proteína C-Reativa/metabolismo , Doenças Cardiovasculares/sangue , Doenças Cardiovasculares/diagnóstico , China/epidemiologia , Comorbidade , Infecções por Coronavirus/diagnóstico , Feminino , Fibrinogênio/metabolismo , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Pandemias , Pneumonia Viral/diagnóstico , Pró-Calcitonina/sangue , Prognóstico , Estudos Retrospectivos , Taxa de Sobrevida/tendências , Tomografia Computadorizada por Raios X
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