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1.
Säo Paulo med. j ; 140(3): 474-485, May-June 2022. tab, graf
Article in English | LILACS | ID: biblio-1377386

ABSTRACT

ABSTRACT BACKGROUND: The thrombin generation test (TGT) has shown promise for investigation of hemorrhagic and thrombotic diseases. However, despite its potential, it still needs standardization. Moreover, few studies have established reference values for TGT parameters. In Brazil, these values have not yet been established. OBJECTIVE: To determine TGT performance and reference intervals for TGT parameters in healthy individuals. DESIGN AND SETTING: Cross-sectional study conducted among participants in the Brazilian Longitudinal Study of Adult Health (Estudo Longitudinal de Saúde do Adulto, ELSA-Brasil). METHODS: The reference sample consisted of 620 healthy individuals. The calibrated automated thrombogram (CAT) method, under low and high tissue factor (TF) conditions, was used to assess thrombin generation. Test performance was analyzed using intra and interassay coefficients of variation (CV) and reference intervals were calculated using the nonparametric method proposed by the International Federation of Clinical Chemistry and the Clinical and Laboratory Standards Institute. RESULTS: The intraassay CV ranged from 1.4% to 2.2% and the interassay CV, 6.8% to 14.7%. The reference intervals for TGT parameters under low and high TF conditions were, respectively: lagtime: 3.0-10.3 and 1.4-3.7 min; endogenous thrombin potential (ETP): 1134.6-2517.9 and 1413.6-2658.0 nM.min; normalized ETP: 0.6-1.3 and 0.7-1.4; peak: 103.2-397.7 and 256.4-479.0 nM; normalized peak: 0.3-1.3 and 0.7-1.2; and time-to-peak: 5.6-16.0 and 3.4-6.7 min. These parameters were categorized relative to sex. Conclusion: TGT performance was adequate and the proposed reference intervals were similar to those of other studies. Our findings may be useful for consolidating the TGT, through contributing to its standardization and validation.


Subject(s)
Humans , Thrombin , Reference Values , Brazil , Cross-Sectional Studies , Longitudinal Studies
2.
Article in Chinese | WPRIM | ID: wpr-928754

ABSTRACT

OBJECTIVE@#To construct a mouse model of Glanzmann's thrombasthenia (GT) with ITGA2B c.2659 C>T (p.Q887X) nonsense mutation by CRISPR/Cas9 technology, and then further explore the expression and function of glycoprotein αIIbβ3 on the surface of platelet membrane.@*METHODS@#The donor oligonucleotide and gRNA vector were designed and synthesized according to the ITGA2B gene sequence. The gRNA and Cas9 mRNA were injected into fertilized eggs with donor oligonucleotide and then sent back to the oviduct of surrogate mouse. Positive F0 mice were confirmed by PCR genotyping and sequence analysis after birth. The F1 generation of heterozygous GT mice were obtained by PCR and sequencing from F0 bred with WT mice, and then homozygous GT mice and WT mice were obtained by mating with each other. The phenotype of the model was then further verified by detecting tail hemorrhage time, saphenous vein bleeding time, platelet aggregation, expression and function of αIIbβ3 on the surface of platelet.@*RESULTS@#The bleeding time of GT mice was significantly longer than that of WT mice (P<0.01). Induced by collagen, thrombin, and adenosine diphosphate (ADP), platelet aggregation in GT mice was significantly inhibited (P<0.01, P<0.01, P<0.05). Flow cytometry analysis showed that the expression of αIIbβ3 on the platelet surface of GT mice decreased significantly compared with WT mice (P<0.01), and binding amounts of activated platelets to fibrinogen were significantly reduced after thrombin stimulation (P<0.01). The spreading area of platelet on fibrinogen in GT mice was significantly smaller than that in WT mice (P<0.05).@*CONCLUSION@#A GT mouse model with ITGA2B c.2659 C>T (p.Q887X) nonsense mutation has been established successfully by CRISPR/Cas9 technology. The aggregation function of platelet in this model is defective, which is consistent with GT performance.


Subject(s)
Animals , CRISPR-Cas Systems , Codon, Nonsense , Disease Models, Animal , Fibrinogen/genetics , Humans , Integrin alpha2/genetics , Mice , Oligonucleotides , Platelet Glycoprotein GPIIb-IIIa Complex/genetics , RNA, Guide , Thrombasthenia/genetics , Thrombin/genetics
3.
Pesqui. vet. bras ; 40(2): 113-120, Feb. 2020. tab, ilus
Article in English | LILACS, VETINDEX | ID: biblio-1098439

ABSTRACT

Patients with chronic kidney disease (CKD) have paradoxical hemostatic potential because they have bleeding episodes but are also prone to thrombosis. Few studies have evaluated blood viscoelastic properties in dogs with kidney disease; on the other hand, hypercoagulability has been observed in these patients. It is also emphasized that the platelet function and its participation in this process have not yet been fully understood. The objective of this study was to evaluate and compare the Thrombin Generation Test (TGT) and also viscoelastic properties of the blood measured by thromboelastometry (TEM) in dogs with proteinuria in CKD. Twenty healthy dogs (Control Group) and 19 dogs with CKD in stage III or IV, classified according to International Renal Interest Society - IRIS, were selected, and the reference test of urine protein:creatinine ratio (UPCR) should be greater than one (CKD group). Blood samples for TEM, thrombin generation, Prothrombin Time (PT), activated Partial Thromboplastin Time (aPTT), and fibrinogen concentration was collected at a single time for both groups after inclusion criteria being confirmed. Statistical analysis was performed according to the distribution of variables at 5% significance level. Differences were observed between healthy dogs and those with proteinuria in CKD noted in TEM. The TGT was unable to differentiate between sick and healthy groups. However, when the nephropathy was stratified, increases in TTP and peak thrombin concentration by TGT were observed in females and dogs over 30 days of diagnosis of CKD. Both tests signaled a discrete state of hypercoagulability. In fact, TEM is more sensitive to detect hypercoagulability in dogs with CKD. However, the TGT has potential clinical application by allowing long-term sample storage.(AU)


Os pacientes com doença renal crônica (DRC) apresentam um potencial hemostático paradoxal, pois apresentam episódios de sangramento, mas também são propensos à trombose. Poucos estudos avaliaram as propriedades viscoelásticas sanguíneas em cães com doenças renais, entretanto, a hipercoagulabilidade já foi observada nestes pacientes. Ressalta-se ainda que a função plaquetária e sua participação neste processo ainda não foram totalmente esclarecidas. O objetivo foi avaliar e comparar o teste de geração de trombina (TGT) e as propriedades viscoelásticas sanguíneas medidas pela tromboelastometria (TEM) em cães com DRC proteinúrica. Foram selecionados 20 cães saudáveis (grupo controle) e 19 cães com DRC em estágios III ou IV classificados segundo o IRIS e a relação proteína/creatinina urinária maior que um (grupo DRC). As amostras de sangue para a realização da tromboelastometria (TEM), geração de trombina, tempo de protrombina (TP), tempo de tromboplastina parcial ativada (TTPA) e concentração de fibrinogênio foram colhidas em momento único para ambos os grupos após os critérios de inclusão confirmados. A análise estatística foi realizada de acordo com a distribuição das variáveis, ao nível de 5% de significância. Foi observada diferença entre os cães saudáveis e os com DRC proteinúrica observados na TEM. O teste de geração de trombina não foi capaz de diferenciar os grupos doente e saudável. Entretanto, quando os nefropatas foram analisados de forma estratificada, foram observados aumentos do ETP e da concentração máxima de trombina (peak) pelo TGT em fêmeas e em cães com mais de 30 dias de diagnóstico da DRC. Ambos os testes sinalizando para um discreto estado de hipercoagulabiliade. A tromboelastometria é mais sensível para detectar a hipercoagulabilidade em cães com DRC. Entretanto, o teste de geração de trombina tem melhor aplicabilidade por permitir o armazenamento da amostra em longo prazo.(AU)


Subject(s)
Animals , Dogs , Thrombosis/prevention & control , Thrombin , Renal Insufficiency, Chronic/blood , Renal Insufficiency, Chronic/veterinary , Hemorrhage/prevention & control , Hemorrhage/veterinary , Hemostasis , Proteinuria/veterinary , Thrombelastography/veterinary
4.
Article in Chinese | WPRIM | ID: wpr-827188

ABSTRACT

OBJECTIVE@#To investigate the effect of protein kinase A (PKA) activation on aggregation funetion of platelets in vitro.@*METHODS@#The peripheral blood of healthy adults were collected, and the washed platelets were gained from collected peripheral blood. The washed platelets were treated with PKA activator Forskolin, then the platelet aggregation was induced by using Ristocetin, Thrombin, Collagen and ADP respectively, the platelet aggregation level was detected by the platelet aggregator.@*RESULTS@#Compared with the controls, 5 μmol/L forskolin significantly inhibited ADP and collagen-induced platelet aggregation (P<0.001), and showed mild inhibiting effect on Thrombin-induced platelet aggregation (P<0.05). 2.5-10 μmol/L forskolin significantly inhibited ADP and Collagen -induced platelet aggregation (P<0.001); but not showed significantly inhibitory effects on Ristocetin-induced platelet aggregation (P>0.05).@*CONCLUSION@#PKA activation inhibits agonists-induced platelet aggregation.


Subject(s)
Blood Platelets , Cyclic AMP-Dependent Protein Kinases , Humans , Platelet Aggregation , Platelet Aggregation Inhibitors , Ristocetin , Thrombin
5.
Hematol., Transfus. Cell Ther. (Impr.) ; 41(3): 244-252, July-Sept. 2019. tab, graf
Article in English | LILACS | ID: biblio-1039926

ABSTRACT

ABSTRACT Background: In order to standardize a thrombin generation() protocol, we analyzed the analytical variables and sensitivity of this test to hypo/hypercoagulability states. Methods: The effect of the tissue factor concentration and the intra- and interassay precision were analyzed. To evaluate the hypercoagulability status, the plasma of women under an oral contraceptive was tested, while plasma from hemophilia A patients at 1, 3 and 7 days after recombinant FVIII infusion, and lyophilized plasma deficient in FVII or FVIII were used for the evaluation of hypocoagulability. Results: The intra-assay coefficient of variation was <10% with 1 and 5 pM of low and high TF. The oral contraceptive users showed increased thrombin generation in comparison to non-users, which was more pronounced with low TF (endogenous thrombin potential ETP) p = 0.0009; peak p = 0.0009; lagtime p = 0.0008). In relation to the FVIII-deficient plasma, a higher TG was observed as FVIII levels were increased and a better discrimination was obtained for different concentrations of FVIII with low TF (ETP p < 0.0001; peak p < 0.0001; lagtime p = 0.0004). Using low TF, plasma from hemophilia A patients showed higher TG values after 1 day of recombinant FVIII infusion vs after 3 days (ETP p < 0.0001; peak p < 0.0001; lagtime p = 0.0407), while the lowest values were observed after 7 days. With FVII-deficient plasma, thrombin generation was lower than normal plasma and a more pronounced difference was observed with high TF compared to low TF (ETP p < 0.0001; peak p < 0.0001; lagtime p < 0.0001). Conclusion: Under our conditions the thrombin generation test seems to be sensitive to evaluation of hyper/hypocoagulability states. Standardization of the thrombin generation test may have an application in the evaluation of bleeding and thrombotic disorders.


Subject(s)
Humans , Male , Female , Adult , Thrombin , Thrombophilia
6.
Article in Chinese | WPRIM | ID: wpr-775261

ABSTRACT

OBJECTIVE@#To develop methods of extraction and purification of Cterminal NUDT9 homology domain of human transient receptor potential melastatin 2 (TRPM2) channel.@*METHODS@#After sonication and centrifuge of strain Rosetta (DE3) which was induced by isopropylthio-β-D-galactoside, GST-NUDT9-H was collected after the binding of supernatant with GST beads and eluted with reduced glutathione. Then the elution buffer containing fusion protein was purified by size exclusion chromatography after concentration and centrifuge. Finally, with the cleavage of thrombin and binding with the GST beads, NUDT9-H with high purity in supernatant was collected.@*RESULTS@#The GST-NUDT9-H fusion protein was stabilized with lysis buffer containing 0.5% n-dodecyl -β-d-maltoside (DDM), and wash buffer containing 0.025% DDM in size-exclusion chromatography system, and finally the NUDT9-H with high purity was obtained after cleaved by thrombin (1 U/2 mg fusion protein) for 24 h.@*CONCLUSIONS@#Due to the poor stability of NUDT9-H, it is necessary to add DDM in extraction and purification buffer to stabilize the conformation of NUDT9-H, so as to increase its yields and purity.


Subject(s)
Escherichia coli , Genetics , Glucosides , Chemistry , Humans , Protein Domains , Protein Stability , Pyrophosphatases , Chemistry , Genetics , Recombinant Fusion Proteins , Chemistry , TRPM Cation Channels , Chemistry , Thrombin , Metabolism
7.
Article in English | WPRIM | ID: wpr-758889

ABSTRACT

Platelet activation has a major role in hemostasis and thrombosis. Various agonists including adenosine diphosphate (ADP) and thrombin interact with G protein-coupled receptors (GPCRs) which transduce signals through various G proteins. Recent studies have elucidated the role of GPCRs and their corresponding G proteins in the regulation of events involved in platelet activation. However, agonist-induced platelet activation in companion animals has not been elucidated. This study was designed to characterize the platelet response to various agonists in dog platelets. We found that 2-methylthio-ADP-induced dog platelet aggregation was blocked in the presence of either P2Y₁ receptor antagonist MRS2179 or P2Y₁₂ receptor antagonist AR-C69931MX, suggesting that co-activation of both the P2Y₁ and P2Y₁₂ receptors is required for ADP-induced platelet aggregation. Thrombin-induced dog platelet aggregation was inhibited in the presence of either AR-C69931MX or the PKC inhibitor GF109203X, suggesting that thrombin requires secreted ADP to induce platelet aggregation in dog platelets. In addition, thrombin-mediated Akt phosphorylation was inhibited in the presence of GF109203X or AR-C69931MX, indicating that thrombin causes Gi stimulation through the P2Y₁₂ receptor by secreted ADP in dog platelets. Unlike human and murine platelets, protease-activated receptor 4 (PAR4)-activating peptide AYPGKF failed to cause dog platelet aggregation. Moreover, PAR1-activating peptide SFLLRN or co-stimulation of SFLLRN and AYPGKF failed to induce dog platelet aggregation. We conclude that ADP induces platelet aggregation through the P2Y₁ and P2Y₁₂ receptors in dogs. Unlike human and murine platelets, selective activation of the PAR4 receptor may be insufficient to cause platelet aggregation in dog platelets.


Subject(s)
Adenosine Diphosphate , Animals , Blood Platelets , Dogs , GTP-Binding Proteins , Hemostasis , Humans , Pets , Phosphorylation , Platelet Activation , Platelet Aggregation , Receptors, Proteinase-Activated , Thrombin , Thrombosis
8.
Article in English | WPRIM | ID: wpr-762798

ABSTRACT

BACKGROUND: Topical hemostatic agents are used when ligation, electrocauterization, or other conventional hemostatic methods are impractical. Because a hemostatic agent is a foreign body, it can cause foreign body reactions, inflammation, and infections that can interfere with the wound healing process. Therefore, we should select hemostatic agents after considering their effects on wound healing. Here, we compared the effects of hemostatic agents on wound healing in a rectus abdominis muscle defect in rats. METHODS: Twelve Sprague Dawley rats were subjected to creation of a 6 × 6 mm defect in the rectus abdominis muscle and divided into four groups: control group; group A, Tachosil fibrin sealant patch; group B, Surgicel Fibrillar oxidized regenerated cellulose; and group C, Surgicel Snow oxidized regenerated cellulose. For the histologic analysis, biopsies were performed on the 3rd, 7th, and 27th days. RESULTS: The foreign body reaction was the weakest in group A and most significant in group C. The inflammatory cell infiltration was the weakest in group A and similar in groups B and C. Muscle regeneration differed among periods. The rats in group A were the most active initially, while those in group C showed prolonged activity. CONCLUSION: Tachosil and Surgicel administration increased inflammation via foreign body reactions, but the overall wound healing process was not significantly affected. The increased inflammation in the Surgicel groups was due to a low pH. We recommend using Tachosil, because it results in less intense foreign body reactions than Surgicel and faster wound healing due to the fibrin action.


Subject(s)
Animals , Biopsy , Cellulose , Cellulose, Oxidized , Fibrin Tissue Adhesive , Fibrin , Fibrinogen , Foreign Bodies , Foreign-Body Reaction , Hemostatics , Hydrogen-Ion Concentration , Inflammation , Ligation , Rats , Rats, Sprague-Dawley , Rectus Abdominis , Regeneration , Snow , Thrombin , Wound Healing , Wounds and Injuries
9.
J. venom. anim. toxins incl. trop. dis ; 25: e20190038, 2019. tab, ilus
Article in English | LILACS, VETINDEX | ID: biblio-1040381

ABSTRACT

Fibrin biopolymers, previously referred as "fibrin glue" or "fibrin sealants", are natural biomaterials with diverse applications on health. They have hemostatic, adhesive, sealant, scaffold and drug delivery properties and have become widely used in medical and dental procedures. Historically, these biomaterials are produced from human fibrinogen and human or animal thrombin, and the possibility of transmission of infectious diseases by human blood is not ruled out. In the 1990s, to overcome this problem, a new heterologous biomaterial composed of a thrombin-like enzyme purified from Crotalus durissus terrificus venom and a cryoprecipitate rich in fibrinogen extracted from buffaloes Bubalus bubalis blood has been proposed. Therefore, a systematic review of studies on exclusively heterologous fibrin sealants published between 1989 and 2018 was carried out using the following databases: PubMed, SciELO and Google Scholar. The keyword used was "heterologous fibrin sealant". The search resulted in 35 scientific papers in PubMed, four in SciELO and 674 in Google Scholar. After applying the inclusion/exclusion criteria and complete reading of the articles, 30 studies were selected, which formed the basis of this systematic review. It has been observed that the only completely heterologous sealant is the one produced by CEVAP/UNESP. This heterologous biopolymer is proven effective by several studies published in refereed scientific journals. In addition, clinical trials phase I/II for the treatment of chronic venous ulcers authorized by the Brazilian Health Regulatory Agency (ANVISA) were completed. Preliminary results have indicated a safe and promising effective product. Phase III clinical trials will be proposed and required to validate these preliminary findings.(AU)


Subject(s)
Biopolymers , Fibrin , Hemostatics , Thrombin
10.
Article in English | LILACS, VETINDEX | ID: biblio-1002503

ABSTRACT

The prevalent class of snake venom serine proteases (SVSP) in Viperidae venoms is the thrombin-like enzymes, which, similarly to human thrombin, convert fibrinogen into insoluble fibrin monomers. However, thrombin-like serine proteases differ from thrombin by being unable to activate factor XIII, thus leading to the formation of loose clots and fibrinogen consumption. We report the functional and biological characterization of a recombinant thrombin-like serine protease from Crotalus durissus collilineatus, named rCollinein-1. Methods: Heterologous expression of rCollinein-1 was performed in Pichia pastoris system according to a previously standardized protocol, with some modifications. rCollinein-1 was purified from the culture medium by a combination of three chromatographic steps. The recombinant toxin was tested in vitro for its thrombolytic activity and in mice for its edematogenicity, blood incoagulability and effect on plasma proteins. Results: When tested for the ability to induce mouse paw edema, rCollinein-1 demonstrated low edematogenic effect, indicating little involvement of this enzyme in the inflammatory processes resulting from ophidian accidents. The rCollinein-1 did not degrade blood clots in vitro, which suggests that this toxin lacks fibrinolytic activity and is not able to directly or indirectly activate the fibrinolytic system. The minimal dose of rCollinein-1 that turns the blood incoagulable in experimental mice is 7.5 mg/kg. The toxin also led to a significant increase in activated partial thromboplastin time at the dose of 1 mg/kg in the animals. Other parameters such as plasma fibrinogen concentration and prothrombin time were not significantly affected by treatment with rCollinein-1 at this dose. The toxin was also able to alter plasma proteins in mouse after 3 h of injection at a dose of 1 mg/kg, leading to a decrease in the intensity of beta zone and an increase in gamma zone in agarose gel electrophoresis Conclusion: These results suggest that the recombinant enzyme has no potential as a thrombolytic agent but can be applied in the prevention of thrombus formation in some pathological processes and as molecular tools in studies related to hemostasis.(AU)


Subject(s)
Snake Venoms , Biological Products , Thrombin , Crotalus , Serine Proteases , Research Report
11.
Acta cir. bras ; 34(1): e20190010000006, 2019. graf
Article in English | LILACS | ID: biblio-983690

ABSTRACT

Abstract Purpose: To investigate whether hirudin exerts its antithrombin action to decrease the ratio of Human Microvascular Endothelial Cells (HMVECs) apoptosis. Methods: Human microvascular endothelial cells (HMVECs) cultured in the third and fifth generations were used. HMVECs were divided into normal group, thrombin group (T group), natrual hirudin group (H group), thrombin + natrual hirudin group (T + H group), AG490 group, thrombin + AG490 group (T + AG490 group), natrual hirudin + AG490 group (H + AG490 group), thrombin + natural hirudin + AG490 (T + H + AG490 group).Apart from the normal group, the other groups were exposed to the relevant drugs for 24 hours.HMVEC apoptosis was assessed by flow cytometric and double Immunofluorescence of phosphorylation of JAK (P-JAK2) and TUNEL assay. Results: Compared with the normal group, in thrombin group the HMVECs apoptosis rate were significantly increased (P<0.05).The results indicated that the index of apoptosis and the apoptosis rate were improved in cultures treated by natural hirudin (T + H group), relative to cultures with thrombin only (T group). We found that the index of apoptosis and the apoptosis rate in the AG490 + thrombin group were higher than that in the hirudin + thrombin group (P<0.05). Double Immunofluorescence of p-JAK2 and TUNEL assays showed that cells were double positive for P-JAK2 uptake and TUNEL detection liquid binding. Conclusion: The natural hirudin and JAK2/STATs signal inhibitor AG490 could block the effects of thrombin. Natural hirudin could attenuate HMVECs apoptosis via antagonizing thrombin and it is suggested that this effect may occur by blocking the JAK2/STATs signaling pathway and this signaling pathways appears to be not the only pathway.


Subject(s)
Humans , Thrombin/drug effects , Antithrombins/pharmacology , Hirudins/pharmacology , Apoptosis/drug effects , Endothelial Cells/drug effects , Protein Kinase Inhibitors/pharmacology , Signal Transduction/drug effects , Cell Proliferation/drug effects , Microvessels/drug effects , Microvessels/metabolism
12.
J. vasc. bras ; 17(4)out.-dez. 2018. graf, tab
Article in Portuguese | LILACS | ID: biblio-969128

ABSTRACT

A number of limitations of standard therapy with warfarin for deep vein thrombosis (DVT) have been established. This overview of systematic reviews presents the baseline results for efficacy and safety of the new direct oral anticoagulants (DOACs) thrombin inhibitors, and activated factor X (Xa) inhibitors in patients with DVT. Searches were run on PubMed and the Cochrane Database of Systematic Reviews. Twenty-three studies were retrieved, and one systematic review was judged eligible. This review scored maximum according to AMSTAR criteria and included 7,596 patients for analysis of thrombin inhibitors and 16,356 patients for analysis of factor Xa inhibitors. The results of the meta-analysis indicate that DOACs are similar for DVT treatment when compared to standard treatment with warfarin. The incidence of major bleeding is somewhat lower in patients treated with factor Xa inhibitors and similar to standard therapy when treated with direct thrombin inhibitors


A terapia padrão com varfarina para a trombose venosa profunda (TVP) tem uma série de limitações já estabelecidas. Essa revisão de revisões sistemáticas elenca os principais resultados de eficácia e segurança dos anticoagulantes orais diretos (DOACs), inibidores da trombina e do fator X ativado (Xa), em pacientes com TVP. A pesquisa foi realizada nas bases PubMed e Cochrane Database of Systematic Reviews. Foram recuperados 23 estudos, e uma revisão sistemática foi considerada elegível. Essa revisão atingiu escore máximo no AMSTAR e incluiu 7.596 pacientes para análise dos inibidores da trombina e 16.356 pacientes para a análise dos inibidores do fator Xa. Os resultados da metanálise indicam que os DOACs apresentam eficácia similar à terapia padrão no tratamento da TVP. A incidência de sangramento maior é um pouco menor nos pacientes tratados com os inibidores do fator Xa e similar à terapia padrão no tratamento com inibidores diretos da trombina


Subject(s)
Humans , Male , Female , Review , Venous Thrombosis/therapy , Anticoagulants/therapeutic use , Warfarin/therapeutic use , Heparin/therapeutic use , Thrombin , Risk Factors , Drug Interactions , Venous Thromboembolism/therapy , Factor Xa Inhibitors/therapeutic use , Rivaroxaban/therapeutic use , Dabigatran/therapeutic use , Hemorrhage
13.
São Paulo; s.n; 20180000. 101 p.
Thesis in Portuguese | LILACS, BBO | ID: biblio-970237

ABSTRACT

O receptor ativado por protease do tipo 1 (PAR1) foi o primeiro membro clonado da família de receptores acoplados à proteína G. Sua ativação tem sido associada ao reparo tecidual e cicatrização óssea. O objetivo do presente estudo foi avaliar o efeito da ativação do PAR1 nas atividades osteogênica e cementogênica de células mesenquimais do ligamento periodontal (CMLP). CMLP obtidas de 3 indivíduos foram cultivadas e tratadas com meio clonogênico (MC) ou meio osteogênico (MO) por 2, 7 e 14 dias. Depósitos de cálcio, concentração de cálcio (sobrenadante), atividade de fosfatase alcalina (ALP), proliferação celular, expressão gênica (qPCR) e níveis proteicos (ELISA) de fatores osteogênicos e cementogênicos foram avaliados na presença de trombina, agonista do PAR1 ou antagonista do PAR1. A ativação do PAR1 levou ao aumento da formação de depósitos de cálcio (p<0,05), o que foi associado ao aumento da concentração de cálcio (p<0,05), atividade da ALP (p<0,05) e proliferação celular (p<0,05). Além disso, os ensaios qPCR e ELISA mostraram que a ativação do PAR1 pode aumentar a expressão gênica de Runx2, OPG e CEMP1 (p<0,05) e níveis proteicos de Runx2 e OPG (p<0,05). Em conclusão, nossos resultados demonstram que a ativação de PAR1 aumenta as atividades osteogênica e cementogênica de CMLP.


Subject(s)
Thrombin , Guided Tissue Regeneration, Periodontal
14.
Chinese Journal of Traumatology ; (6): 311-315, 2018.
Article in English | WPRIM | ID: wpr-771647

ABSTRACT

Trauma-induced coagulopathy is classified into primary and secondary coagulopathy, with the former elicited by trauma and traumatic shock itself and the latter being acquired coagulopathy induced by anemia, hypothermia, acidosis, and dilution. Primary coagulopathy consists of disseminated intravascular coagulation and acute coagulopathy of trauma shock (ACOTS). The pathophysiology of ACOTS is the suppression of thrombin generation and neutralization of plasminogen activator inhibitor-1 mediated by activated protein C that leads to hypocoagulation and hyperfibrinolysis in the circulation. This review tried to clarify the validity of activated protein C hypothesis that constitutes the main pathophysiology of the ACOTS in experimental trauma models.


Subject(s)
Acute Disease , Animals , Blood Coagulation Disorders , Disease Models, Animal , Disseminated Intravascular Coagulation , Humans , Mice , Plasminogen Activator Inhibitor 1 , Protein C , Physiology , Thrombin , Wounds and Injuries
15.
Article in English | WPRIM | ID: wpr-758421

ABSTRACT

Arteriovenous malformation (AVM) of the mandible is a rare vascular condition that can manifest as a wide range of symptoms and, on rare occasions, cause fatal hemorrhage. The symptoms of mandibular AVM can range from soft tissue swelling and tooth mobility to severe hemorrhage. The recognition of early symptoms is crucial for the prevention of a fatal hemorrhage and for the proper diagnosis and treatment of mandibular AVM. For emergency hemostasis of a ruptured mandibular AVM, manual compression with gauze, topical thrombin, absorbable hemostat, suturing the lesion, and replanting the extracted tooth is recommended. Multiple treatment options for mandibular AVM are available, such as arterial embolization, venous embolization, direct surgical closure, and bone resection. A combination of treatment options should be considered in complicated cases. We report a case of a 10-year-old girl with a previous history of telangiectasia on the right cheek presented with cardiac arrest resulting from massive bleeding immediately after a tooth extraction.


Subject(s)
Arteriovenous Malformations , Cheek , Child , Diagnosis , Emergencies , Female , Heart Arrest , Hemorrhage , Hemostasis , Humans , Mandible , Telangiectasis , Thrombin , Tooth , Tooth Extraction , Tooth Mobility
16.
Article in English | WPRIM | ID: wpr-713195

ABSTRACT

Intraoperative bovine-derived topical thrombin is still widely used for hemostasis during surgery. A 38-year-old woman with chronic spontaneous urticaria was referred to the orthopedic surgery department for herniated disk and myelopathy. During the first stage of operation, bovine-derived thrombin powder soaked in Gelfoam was used as a hemostatic aid. After 30 minutes, the patient developed anaphylactic shock with systemic skin rash and angioedema. Repeated intravenous bolus and infusion of vasopressor were carried out, and her blood pressure normalized. Skin test and specific immunoglobulin E test showed positive results for bovine thrombin and beef, respectively. During the second stage of operation (After 10 days from first stage of operation), bovine-derived thrombin powder was excluded and the operation was successful without any unexpected events. Therefore, bovine thrombin should be used with caution because it might cause anaphylaxis.


Subject(s)
Adult , Anaphylaxis , Angioedema , Blood Pressure , Exanthema , Female , Gelatin Sponge, Absorbable , Hemostasis , Humans , Immunoglobulin E , Immunoglobulins , Intervertebral Disc Displacement , Orthopedics , Red Meat , Skin Tests , Spinal Cord Diseases , Thrombin , Urticaria
17.
Article in English | WPRIM | ID: wpr-739716

ABSTRACT

BACKGROUND: Platelet-rich plasma (PRP) stimulates cell proliferation and enhances matrix gene expression and synthesis. However, there have been no comparative study of the PRP effect on the normal and degenerative tenocytes. The purpose of this study was to compare the effect of PRP on tenocytes from normal and degenerative tendon. METHODS: Tendon tissues were obtained from patients undergoing arthroscopic repair (n=9) and from healthy donors (n=3). Tenocytes were cultured with 10% (vol/vol) platelet-poor plasma, PRP activated with calcium, and PRP activated with calcium and thrombin. The total cell number was assessed at days 7 and 14. The expressions of type I and III collagen, decorin, tenascin-C, and scleraxis were evaluated by quantitative real-time reverse transcriptase polymerase chain reaction. The total collagen and glycosaminoglycan (GAG) synthesis was evaluated at days 7 and 14. RESULTS: No differences were observed between the groups at day 7, but cell proliferation was remarkably increased in tenocytes from the degenerative tendon at day 14. In both tenocyte groups, the gene expressions of type I and III collagen were up-regulated. GAG synthesis was greater in the normal tendon, whereas the expressions of decorin and tenascin-C were increased in tenocytes from the degenerative tendon. Tenocytes from the degenerative tendon had higher fold-change of GAG synthesis and a lower collagen III/I ratio than normal tenocytes. CONCLUSIONS: PRP promoted the cell proliferation and enhanced the synthesis of tendon matrix in both groups. PRP has a greater positive effect on cell proliferation, matrix gene expression and synthesis in tenocytes from degenerative tendon.


Subject(s)
Calcium , Cell Count , Cell Proliferation , Collagen , Decorin , Gene Expression , Humans , Plasma , Platelet-Rich Plasma , Reverse Transcriptase Polymerase Chain Reaction , Rotator Cuff , Tears , Tenascin , Tendons , Thrombin , Tissue Donors
18.
Article in English | WPRIM | ID: wpr-739175

ABSTRACT

Hemorrhage following pancreatitis may become complicated during the disease course and with possibly fatal consequences. Radiologic findings are as follows: the presence of hematomas, hemorrhagic pseudocysts, extravasation of contrast media or the formation of arterial pseudoaneurysms. The digital subtraction angiography findings are as follows: contrast extravasation due to arterial rupture; pseudoaneurysm formation; and luminal irregularity. A pseudoaneurysm is considered to be treated as soon as detected due to its risk of rupture. Endovascular management, which includes embolization using coils, N-butyl cyanoacrylate, gelatin sponge, stents, and thrombin, is an effective option for the treatment for pancreatitis-related bleeding.


Subject(s)
Aneurysm, False , Angiography, Digital Subtraction , Cyanoacrylates , Embolization, Therapeutic , Endovascular Procedures , Extravasation of Diagnostic and Therapeutic Materials , Gelatin , Hematoma , Hemorrhage , Pancreatitis , Phenobarbital , Porifera , Rupture , Stents , Thrombin
19.
Blood Research ; : 41-48, 2018.
Article in English | WPRIM | ID: wpr-713630

ABSTRACT

BACKGROUND: Korean National Health Insurance reimburses factor VIII (FVIII) and factor IX (FIX) clotting factor concentrate (CFC) infusions to discrepant activity levels, allowing elevation of FVIII activity to 60 IU/dL and FIX to 40 IU/dL. We aimed to assess hemostatic response to these target levels using global hemostatic assays. METHODS: We enrolled 34 normal healthy men, 34 patients with hemophilia A, and 36 with hemophilia B, with residual factor activity of 3 IU/dL or less and without inhibitors. Patients with hemophilia A and B received injected CFCs according to reimbursement guidelines. Fifteen minutes after injection, we assessed hemostatic response with global hemostatic assays: thrombin generation assay (TGA), thromboelastography (TEG), and clot waveform analysis (CWA). RESULTS: Normal healthy men and patients with hemophilia A and B were 36.7, 37.2, and 35.1 years old, respectively. FVIII and recombinant FIX concentrate doses were 28.8 IU/kg and 43.6 IU/kg. Post-infusion FVIII activity rose from 0.5 IU/dL to 69.4 IU/dL, while FIX activity rose from 1.4 IU/dL to 46.8 IU/dL. Post-infusion peak thrombin concentrations in hemophilia A and B were 116.6 nM/L and 76.4 nM/L (P < 0.001). Post-infusion endogenous thrombin potential (ETP) in hemophilia A and B was 1349.8 nM/min and 915.6 nM (P < 0.001). TEG index of hemophilia A and B was 0.11 and −0.51 (P=0.006). CONCLUSION: Current reimbursed doses for FIX concentrates are insufficient to achieve hemostatic responses comparable to those after reimbursed doses for FVIII concentrates in terms of peak thrombin concentration, ETP, and TEG index.


Subject(s)
Factor IX , Factor VIII , Hemophilia A , Hemophilia B , Humans , Male , National Health Programs , Thrombelastography , Thrombin
20.
Rev. bras. hematol. hemoter ; 39(3): 259-265, July-Sept. 2017. tab, graf, ilus
Article in English | LILACS | ID: biblio-898939

ABSTRACT

Abstract The existing techniques to evaluate hemostasis in clinical laboratories are not sensitive enough to detect hypercoagulable and mild hypocoagulable states. Under different experimental conditions, the thrombin generation test may meet these requirements. This technique evaluates the overall balance between procoagulant and anticoagulant forces and has provided new insights in our understanding of the coagulation cascade, as well as of the diagnosis of hypocoagulability and hypercoagulability conditions. Thrombin generated in the thrombin generation test can be quantified as platelet-rich or platelet-poor plasma using the calibrated automated thrombogram method, which monitors the cleavage of a fluorogenic substrate that is simultaneously compared to the known thrombin activity in a non-clotting plasma sample. The calibrated automated thrombogram method is an open system, in which different antibodies, proteins, enzymes and peptides can be introduced to answer specific questions regarding hemostatic processes. The thrombin generation test has great clinical potential, such as in monitoring patients taking anticoagulants and antiplatelet drugs, screening for genetic or acquired thrombotic disorders, and evaluating bleeding risk control in patients with hemophilia using bypass agents or replacement therapy. Different to conventional coagulation tests, the thrombin generation test can be used for an overall evaluation of hemostasis, the results of which can then be used to evaluate specific characteristics of hemostasis, such as prothrombin time, activated partial thromboplastin time, and levels of fibrinogen and other coagulation factors. The introduction of this method will contribute to a better understanding and evaluation of overall hemostatic processes; however, this method still requires standardization and clinical validation.


Subject(s)
Thrombin , Homeostasis
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