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1.
Pak J Pharm Sci ; 34(3): 925-932, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-34602415

RESUMO

MicroRNA (miRNA)-26a is one of the tumor suppressor genes that has been down regulated during the development of hepatocellular carcinoma (HCC). This work was conducted to evaluate the possible preventive effect of exogenous miRNA-26a administration on diethylnitrosamine (DEN)-mediated HCC. Balb/C mice were intraperitoneally injected with saline (Normal group), DEN (HCC group) or miRNA-26a (HCC+miRNA-26a group). On week 8, 12, 16 and 20, the concentrations of alpha-fetoprotein (AFP), des-gamma carboxyprothrombin (DCP), the levels of helper T cells-associated cytokines, and the vascular endothelial growth factor (VEGF), were measured. Flow cytometry determined the frequencies of regulatory T (Treg) cells. The concentrations of AFP, DCP and VEGF, as well as the frequency of Treg cells showed significantly lower values following miRNA-26a administration than in HCC group. miRNA-26a administration has reduced the levels of IL (interleukin)-2 and TNF (tumor necrosis factor)-α, in contrast, IL-10 level was markedly elevated in comparison to HCC model at all experimental time points. The restore of miRNA-26a function significantly (P<0.001) down regulated the expression levels of survivin & caspase-3 compared to HCC group. The obtained data introduce an evidence for the suppressive impact of miRNA-26a on liver tumor formation and its possible manipulation as a therapeutic design for HCC.


Assuntos
Carcinoma Hepatocelular/metabolismo , Neoplasias Hepáticas Experimentais/metabolismo , Neoplasias Hepáticas/metabolismo , Fígado/efeitos dos fármacos , MicroRNAs/farmacologia , Alquilantes/toxicidade , Animais , Apoptose/efeitos dos fármacos , Biomarcadores/metabolismo , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/patologia , Caspase 3/efeitos dos fármacos , Caspase 3/metabolismo , Citocinas/efeitos dos fármacos , Citocinas/metabolismo , Dietilnitrosamina/toxicidade , Interleucina-10/metabolismo , Interleucina-2/metabolismo , Fígado/metabolismo , Fígado/patologia , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/patologia , Neoplasias Hepáticas Experimentais/genética , Neoplasias Hepáticas Experimentais/patologia , Camundongos , Precursores de Proteínas/efeitos dos fármacos , Precursores de Proteínas/metabolismo , Protrombina/efeitos dos fármacos , Protrombina/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Survivina/efeitos dos fármacos , Survivina/metabolismo , Linfócitos T Auxiliares-Indutores/efeitos dos fármacos , Linfócitos T Auxiliares-Indutores/metabolismo , Fator de Necrose Tumoral alfa/efeitos dos fármacos , Fator de Necrose Tumoral alfa/metabolismo , Fator A de Crescimento do Endotélio Vascular/efeitos dos fármacos , Fator A de Crescimento do Endotélio Vascular/metabolismo , alfa-Fetoproteínas/efeitos dos fármacos , alfa-Fetoproteínas/metabolismo
2.
Medicine (Baltimore) ; 100(23): e26221, 2021 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-34115006

RESUMO

BACKGROUND: Vitamin K has long been regarded as a procoagulant drug by physicians, and concerns have been raised with regard to its effects on hemostasis. Although many studies have shown that vitamin K supplementation is safe for thrombotic events, the effect of vitamin K supplementation on the activities of vitamin K dependent procoagulation factors in healthy individuals is not available. OBJECTIVES: This study aimed to investigate whether vitamin K2 supplementation at recommended doses affects the activity of vitamin K dependent procoagulation factors in healthy individuals without any anticoagulation treatment. DESIGN: Forty healthy volunteers between 25 and 40 years of age were recruited. Menaquinone-7 (MK-7) was administrated at 90 µg for 30 days. Prothrombin time (PT), activated partial thromboplastin time (APTT), thrombin time (TT), and blood coagulation factors II, VII, IX, and X activities and Protein induced by vitamin K absence or antagonist-II (PIVKA-II) were measured on days 0 and 30 after MK-7 administration. RESULTS: PT, APTT, and TT showed no significant differences on day 30 when compared with baseline. The activities of coagulation factors II, VII, IX, and X on day 30 showed no significant differences with those at baseline. PIVKA-II levels were unchanged after 30 days of MK-7 supplementation. CONCLUSIONS: MK-7 supplementation at recommended dosage does not affect vitamin K-dependent coagulation factors' coagulation activity, and does not enhance the carboxylation of prothrombin in healthy individuals. This indicated that MK-7 administration does not alter hemostatic balance in healthy populations without anticoagulation treatment.


Assuntos
Fatores de Coagulação Sanguínea/efeitos dos fármacos , Suplementos Nutricionais/normas , Vitamina K 2/farmacologia , Adulto , Antifibrinolíticos/farmacologia , Antifibrinolíticos/uso terapêutico , Fatores de Coagulação Sanguínea/análise , Suplementos Nutricionais/estatística & dados numéricos , Fator IX/análise , Fator IX/efeitos dos fármacos , Fator VII/análise , Fator VII/efeitos dos fármacos , Fator X/análise , Fator X/efeitos dos fármacos , Feminino , Voluntários Saudáveis/estatística & dados numéricos , Humanos , Masculino , Tempo de Tromboplastina Parcial/métodos , Tempo de Tromboplastina Parcial/estatística & dados numéricos , Protrombina/análise , Protrombina/efeitos dos fármacos , Tempo de Protrombina/métodos , Tempo de Protrombina/estatística & dados numéricos , Tempo de Trombina/métodos , Tempo de Trombina/estatística & dados numéricos , Vitamina K 2/uso terapêutico
3.
J. vasc. bras ; 17(2): 109-116, abr.jun.2018.
Artigo em Português | LILACS | ID: biblio-910641

RESUMO

A anticoagulação oral com varfarina é usada por milhões de pacientes em todo o mundo, apresentando segurança e eficácia bem estabelecidas. Ainda assim, na atenção primária à saúde, os anticoagulantes estão entre as classes de medicamentos mais associadas a erros de medicação fatais. Objetivo: Verificar o nível de informação e a adesão ao tratamento com varfarina em pacientes acompanhados em ambulatório de atenção primária à saúde. Método: Foi realizado um estudo transversal de uma coorte prospectiva com 60 pacientes em uso de varfarina no município de Ijuí, Rio Grande do Sul. Utilizou-se questionário para verificar o nível de informações dos usuários quanto à prescrição e o nível das informações prestadas pela equipe de saúde aos usuários. A Escala de Adesão Terapêutica de Morisky de Oito Itens (MMAS-8) e o coeficiente internacional normatizado ( international normalized ratio , INR) foram usados para verificar a adesão ao tratamento. Resultados: Os resultados foram expressos em valores absolutos e relativos e razão de prevalência, com seu respectivo intervalo de confiança de 95%. Verificou-se que 83,3% dos participantes tiveram nível de informação insuficiente prestada pela equipe de saúde, 50,0% não souberam informar sobre o uso correto do medicamento, 86,7% foram não aderentes ao tratamento segundo a MMAS-8, e 63,3% estavam fora do intervalo terapêutico adequado. Conclusão: Neste estudo, observou-se a necessidade de melhorar a qualidade das informações prestadas aos usuários e criar estratégias para adesão ao tratamento, visando à segurança do paciente em tratamento com varfarina na atenção primária à saúde.


Oral anticoagulation therapy with warfarin is widely used around the world and its safety and efficacy are well-established. Nevertheless, anticoagulants are among the drug classes most associated with fatal medication errors in primary health care. Objective: To investigate patient knowledge, the level of information provided, and medication adherence in patients treated with warfarin at a primary health care service. Method: A cross-sectional study of a prospective cohort of 60 patients on warfarin treatment in the town of Ijuí, Rio Grande do Sul, Brazil. A questionnaire was administered to test patients' knowledge about their prescriptions and the level of information provided by the health team. The 8-item Morisky Medication Adherence Scale (MMAS-8) and International Normalized Ratio (INR) were used to verify adherence to treatment. Results: The results were expressed in absolute and relative values and prevalence ratios were calculated, with respective 95% confidence intervals. It was found that 83.3% of the participants had been given insufficient information by the health team, 50% did not know how to use the medication correctly, 86.7% were not adherent to the treatment according to MMAS-8 and 63.3% were outside of the correct INR range. Conclusion: In this study, we observed a need to improve the quality of information provided to users and to develop strategies to improve adherence to treatment, to ensure the safety of patients treated with warfarin in primary health care services.


Assuntos
Humanos , Feminino , Pessoa de Meia-Idade , Coagulação Sanguínea/efeitos dos fármacos , Atenção Primária à Saúde/ética , Protrombina/efeitos dos fármacos , Varfarina/administração & dosagem , Varfarina/efeitos adversos , Adesão à Medicação
4.
Clin Appl Thromb Hemost ; 23(3): 211-220, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-27553841

RESUMO

Recombinant factor VIIa (rFVIIa) is used in the management of bleeding in patients with hemophilia. A generic biosimilar version of NovoSeven is also developed (AryoSeven). To compare the activation profile of NovoSeven and AryoSeven, 2 commercially available protein complex concentrates (PCCs) were used. Profilnine activated by RecombiPlasTin 2G resulted in conversions of prothrombin to prethrombin and thrombin at 5 to 30 minutes. However, addition of rFVIIa at final concentration range of 0.25 to 0.5 µg/mL to the same mixture resulted in total conversion of prothrombin to thrombin with a doublet at 36 kDa. Recombinant factor VIIa alone did not generate thrombin in native Beriplex, and the addition of rFVIIa to Beriplex failed to generate thrombin. Beriplex activated by RecombiPlasTin 2G resulted in complete conversion of prothrombin to thrombin. Both NovoSeven and AryoSeven exhibited similar activation profiles. These studies indicate that the activation of PCCs by both rFVIIa preparations results in comparable generation of thrombin.


Assuntos
Fatores de Coagulação Sanguínea/efeitos dos fármacos , Fator VIIa/farmacologia , Hemorragia/tratamento farmacológico , Humanos , Protrombina/efeitos dos fármacos , Protrombina/metabolismo , Proteínas Recombinantes/farmacologia , Trombina/metabolismo
5.
Clin Exp Obstet Gynecol ; 43(3): 334-40, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27328486

RESUMO

PURPOSE OF INVESTIGATION: To compare the effects of desogestrel (DSG) 150 mcg/ethinyl estradiol (EE) 20 mcg for 21 days followed by either seven days of EE ten mcg (21/7-active) or no treatment (DSG/EE+no Tx) on hemostatic markers. MATERIALS AND METHODS: This was a randomized, multicenter, open-label study that enrolled healthy premenopausal women. Non-inferiority of 21/7-active to DSG/EE+no Tx was determined if the upper limit of the two-sided 95% CI of the mean treatment difference in prothrombin fragment 1+2 (F1+2) over 24 weeks between groups was < 130 pmol/L. RESULTS: 246 subjects (n = 125, 21/7-active; n = 121, DSG/EE+no Tx) comprised the primary analysis. Mean F1+2 levels increased in both 21/7-active and DSG/EE+no Tx regimens (least square [LS] mean changes +45 pmol/L and +56.8 pmol/L, respectively). LS mean treatment difference was -11.8 pmol/L (95% CI: -54.8, 31.2). CONCLUSION: The effect of adding EE ten mcg to the seven-day hormone-free interval of DSG/EE on F1+2 levels was non-inferior to traditional DSG/EE.


Assuntos
Coagulação Sanguínea/efeitos dos fármacos , Anticoncepcionais Orais Combinados/farmacologia , Anticoncepcionais Orais Sequenciais/farmacologia , Desogestrel/farmacologia , Etinilestradiol/farmacologia , Produtos de Degradação da Fibrina e do Fibrinogênio/efeitos dos fármacos , Fragmentos de Peptídeos/efeitos dos fármacos , Proteína C/efeitos dos fármacos , Proteína S/efeitos dos fármacos , Protrombina/efeitos dos fármacos , Adulto , Antitrombinas/sangue , Anticoncepcionais Orais Combinados/administração & dosagem , Anticoncepcionais Orais Sequenciais/administração & dosagem , Desogestrel/administração & dosagem , Etinilestradiol/administração & dosagem , Feminino , Produtos de Degradação da Fibrina e do Fibrinogênio/metabolismo , Humanos , Tempo de Tromboplastina Parcial , Fragmentos de Peptídeos/sangue , Proteína C/metabolismo , Proteína S/metabolismo , Adulto Jovem
6.
Nucleic Acid Ther ; 25(6): 297-305, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26390010

RESUMO

The tissue half-life of second-generation antisense oligonucleotide drugs (ASOs) is generally longer than traditional small molecule therapeutics. Thus, a strategy to reverse the activity of antisense drugs is warranted in certain settings. In this study, we describe a strategy employing the administration of a complementary sense oligonucleotide antidote (SOA). As a model system we have chosen to target the coagulation factor and antithrombotic drug target, prothrombin, to assess the feasibility of this approach. ASO targeting mouse prothrombin specifically suppressed >90% hepatic prothrombin mRNA levels and circulating prothrombin protein in mice. These effects were dose- and time-dependent, and as expected produced predictable increases in anticoagulation activity [prothrombin time/activated partial thromboplastin time (PT/aPTT)]. Treatment with prothrombin SOAs resulted in a dose-dependent reversal of ASO activity, as measured by a return in prothrombin mRNA levels and thrombin activity, and normalization of aPTT and PT. The antithrombotic activity of prothrombin ASOs was demonstrated in a FeCl3-induced thrombosis mouse model, and as predicted for this target, the doses required for antithrombotic activity were also associated with increased bleeding. Treatment with SOA was able to prevent prothrombin ASO-induced bleeding in a dose-dependent manner. These studies demonstrate for the first time the utility of SOAs to selectively and specifically reverse the intracellular effects of an antisense therapy.


Assuntos
Oligonucleotídeos Antissenso/antagonistas & inibidores , Oligonucleotídeos/farmacologia , Protrombina/efeitos dos fármacos , Animais , Relação Dose-Resposta a Droga , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Oligonucleotídeos Antissenso/farmacologia
7.
Arterioscler Thromb Vasc Biol ; 35(10): 2083-91, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26315404

RESUMO

As a novel class of therapeutics, aptamers, or nucleic acid ligands, have garnered clinical interest because of the ease of isolating a highly specific aptamer against a wide range of targets, their chemical flexibility and synthesis, and their inherent ability to have their function reversed. The following review details the development and molecular mechanisms of aptamers targeting specific proteases in the coagulation cascade. The ability of these anticoagulant aptamers to bind to and inhibit exosite function rather than binding within the active site highlights the importance of exosites in blocking protein function. As both exosite inhibitors and reversible agents, the use of aptamers is a promising strategy for future therapeutics.


Assuntos
Aptâmeros de Nucleotídeos/uso terapêutico , Coagulação Sanguínea/efeitos dos fármacos , Terapia de Alvo Molecular/métodos , Aptâmeros de Nucleotídeos/farmacologia , Coagulação Sanguínea/genética , Ensaios Clínicos Fase I como Assunto , Ensaios Clínicos Fase II como Assunto , Feminino , Humanos , Masculino , Protrombina/efeitos dos fármacos , Protrombina/metabolismo , Sensibilidade e Especificidade , Serina Endopeptidases/efeitos dos fármacos , Serina Endopeptidases/metabolismo , Trombina/efeitos dos fármacos , Trombina/metabolismo
8.
J Cardiol ; 65(3): 191-6, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25192595

RESUMO

BACKGROUND: Rivaroxaban is an oral anticoagulant that effectively prevents thromboembolic complications using fixed doses without requiring laboratory monitoring. In this study, we aimed to examine the coagulation status in patients with non-valvular atrial fibrillation (NVAF) treated with rivaroxaban compared with warfarin. METHODS AND RESULTS: The study group consisted of 85 consecutive Japanese patients with NVAF who received rivaroxaban (n=33) or warfarin (n=52) from June 2013 to February 2014. We compared the coagulation status between the rivaroxaban and warfarin treatments. The prothrombin time (PT) values did not significantly differ between the two groups. However, the prothrombin fragment 1+2 (F1+2) level, a marker of thrombin generation, was significantly higher in the rivaroxaban group than the warfarin group (202±88pmol/l vs. 114±79pmol/l, p<0.001). Next, we collected blood samples from 18 patients taking rivaroxaban at 3h and 15h after the drug intake and evaluated the time-dependent changes in the coagulation status. The PT values at 3h after the drug intake were significantly more prolonged than those at 15h (p<0.001). However, there were no significant differences in the F1+2 levels between the two time points (194±73pmol/l [at 3h] vs. 165±61pmol/l [at 15h], p=0.112). CONCLUSIONS: Our preliminary results suggest that the thrombin generation level is stable regardless of the time elapsed after rivaroxaban intake, and warfarin treatment may inhibit thrombin generation more aggressively than rivaroxaban.


Assuntos
Anticoagulantes/farmacologia , Fibrilação Atrial/sangue , Inibidores do Fator Xa/farmacologia , Fragmentos de Peptídeos/efeitos dos fármacos , Tempo de Protrombina , Protrombina/efeitos dos fármacos , Rivaroxabana/farmacologia , Trombina/metabolismo , Varfarina/farmacologia , Idoso , Idoso de 80 Anos ou mais , Povo Asiático , Feminino , Humanos , Japão , Masculino , Pessoa de Meia-Idade , Fatores de Tempo
9.
Bratisl Lek Listy ; 115(7): 434-8, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25077367

RESUMO

The venom of Echis carinatus is rich in proteins and peptides effective on the hemostatic system. This venom is contains metalloproteinase which convert prothrombin to meizothrombin. The prothrombin activator which leads to the formation of small blood clots inside the blood vessels throughout the body. To understand the mechanism of the effects of Iranian Echis carinatus venom, the effects of E. carinatus on human and Wistar rat plasma, plasma proteins (prothrombin and fibrinogen) and blood coagulation were studied. Proteolytic activity of the crude venom on blood coagulation factors such as prothrombin, partial thromboplastin and fibrinogen times were studied. In the present study the PT test for human plasma was reduced from 13.4 s (±0.59) to 8.6 s (±0.64) when human plasma was treated with crude venom (concentration of venom was 1 mg/ml) and for rat plasma PT was reduced from 14.5 s (±0.47) to 8 s (±0.49). Some possible biological and biochemical effects of IEc crude venom were investigated. The blood coagulation in human and in rat were investigated in vivo and in-vitro. In this paper, we show that the procoagulant action of Echis carinatus venom is due in part to a protein component that activates prothrombin and the procoagulant activity on human and rat plasma was evaluated (Tab. 2, Fig. 2, Ref. 31).


Assuntos
Coagulação Sanguínea/efeitos dos fármacos , Endopeptidases/farmacologia , Ativadores de Enzimas/metabolismo , Fibrinogênio/metabolismo , Protrombina/metabolismo , Venenos de Víboras/farmacologia , Adulto , Animais , Fibrinogênio/efeitos dos fármacos , Humanos , Plasma/efeitos dos fármacos , Plasma/metabolismo , Protrombina/efeitos dos fármacos , Ratos , Ratos Wistar
10.
J Am Heart Assoc ; 3(4)2014 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-25012289

RESUMO

BACKGROUND: C-reactive protein (CRP) binds to damaged cells, activates the classical complement pathway, is elevated in multiple inflammatory conditions, and provides prognostic information on risk of future atherosclerotic events. It is controversial, however, as to whether inhibiting CRP synthesis would have any direct anti-inflammatory effects in humans. METHODS AND RESULTS: A placebo-controlled study was used to evaluate the effects of ISIS 329993 (ISIS-CRPR x) on the acute-phase response after endotoxin challenge in 30 evaluable subjects. Healthy adult males were randomly allocated to receive 6 injections over a 22-day period of placebo or active therapy with ISIS 329993 at 400- or 600-mg doses. Eligible subjects were subsequently challenged with a bolus of endotoxin (2 ng/kg). Inflammatory and hematological biomarkers were measured before and serially after the challenge. ISIS-CRPR x was well tolerated with no serious adverse events. Median CRP levels increased more than 50-fold from baseline 24 hours after endotoxin challenge in the placebo group. In contrast, the median increase in CRP levels was attenuated by 37% (400 mg) and 69% (600 mg) in subjects pretreated with ISIS-CRPR x (P<0.05 vs. placebo). All other aspects of the acute inflammatory response were similar between treatment groups. CONCLUSION: Pretreatment of subjects with ISIS-CRPR x selectively reduced the endotoxin-induced increase in CRP levels in a dose-dependent manner, without affecting other components of the acute-phase response. These data demonstrate the specificity of antisense oligonucleotides and provide an investigative tool to further define the role of CRP in human pathological conditions.


Assuntos
Reação de Fase Aguda , Proteína C-Reativa/efeitos dos fármacos , Endotoxinas/farmacologia , Oligonucleotídeos Antissenso/farmacologia , Oligonucleotídeos/farmacologia , Adolescente , Adulto , Proteína C-Reativa/antagonistas & inibidores , Proteína C-Reativa/biossíntese , Quimiocina CCL2/sangue , Quimiocina CCL2/efeitos dos fármacos , Selectina E/sangue , Selectina E/efeitos dos fármacos , Produtos de Degradação da Fibrina e do Fibrinogênio/efeitos dos fármacos , Voluntários Saudáveis , Humanos , Interleucina-6/sangue , Masculino , Fragmentos de Peptídeos/sangue , Fragmentos de Peptídeos/efeitos dos fármacos , Protrombina/efeitos dos fármacos , Fator de Necrose Tumoral alfa/sangue , Fator de Necrose Tumoral alfa/efeitos dos fármacos , Adulto Jovem
11.
Braz. j. med. biol. res ; 45(10): 929-934, Oct. 2012. ilus, tab
Artigo em Inglês | LILACS | ID: lil-647751

RESUMO

Lopap, found in the bristles of Lonomia obliqua caterpillar, is the first exogenous prothrombin activator that shows serine protease-like activity, independent of prothrombinase components and unique lipocalin reported to interfere with hemostasis mechanisms. To assess the action of an exogenous prothrombin activator reversing the anticoagulant and antihemostatic effect induced by low molecular weight heparin (LMWH), male New Zealand rabbits (N = 20, weighing 3.8-4.0 kg) allocated to 4 groups were anticoagulated with 1800 IU/kg LMWH (iv) over 2 min, followed by iv administration of saline (SG) or recombinant Lopap (rLopap) at 1 µg/kg (LG1) or 10 µg/kg (LG10), 10 min after the injection of LMWH, in a blind manner. Control animals (CG) were treated only with saline. The action of rLopap was assessed in terms of activated partial thromboplastin time (aPTT), prothrombin fragment F1+2, fibrinogen, and ear puncture bleeding time (BT) at 5, 10, 15, 17, 20, 30, 40, 60, and 90 min after initiation of LMWH infusion. LG10 animals showed a decrease of aPTT in more than 50% and BT near to normal baseline. The level of prothrombin fragment F1+2 measured by ELISA had a 6-fold increase with rLopap treatment (10 µg/kg) and was inversely proportional to BT in LMWH-treated animals. Thus, Lopap, obtained in recombinant form using E. coli expression system, was useful in antagonizing the effect of LMWH through direct prothrombin activation, which can be a possible strategy for the reversal of bleeding and anticoagulant events.


Assuntos
Animais , Masculino , Coelhos , Anticoagulantes/uso terapêutico , Coagulação Sanguínea/efeitos dos fármacos , Hemorragia/tratamento farmacológico , Antagonistas de Heparina/farmacologia , Heparina de Baixo Peso Molecular/antagonistas & inibidores , Protrombina/efeitos dos fármacos , Serina Endopeptidases/farmacologia , Hemorragia/induzido quimicamente
12.
Braz J Med Biol Res ; 45(10): 929-34, 2012 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-22735179

RESUMO

Lopap, found in the bristles of Lonomia obliqua caterpillar, is the first exogenous prothrombin activator that shows serine protease-like activity, independent of prothrombinase components and unique lipocalin reported to interfere with hemostasis mechanisms. To assess the action of an exogenous prothrombin activator reversing the anticoagulant and antihemostatic effect induced by low molecular weight heparin (LMWH), male New Zealand rabbits (N = 20, weighing 3.8-4.0 kg) allocated to 4 groups were anticoagulated with 1800 IU/kg LMWH (iv) over 2 min, followed by iv administration of saline (SG) or recombinant Lopap (rLopap) at 1 µg/kg (LG1) or 10 µg/kg (LG10), 10 min after the injection of LMWH, in a blind manner. Control animals (CG) were treated only with saline. The action of rLopap was assessed in terms of activated partial thromboplastin time (aPTT), prothrombin fragment F1+2, fibrinogen, and ear puncture bleeding time (BT) at 5, 10, 15, 17, 20, 30, 40, 60, and 90 min after initiation of LMWH infusion. LG10 animals showed a decrease of aPTT in more than 50% and BT near to normal baseline. The level of prothrombin fragment F1+2 measured by ELISA had a 6-fold increase with rLopap treatment (10 µg/kg) and was inversely proportional to BT in LMWH-treated animals. Thus, Lopap, obtained in recombinant form using E. coli expression system, was useful in antagonizing the effect of LMWH through direct prothrombin activation, which can be a possible strategy for the reversal of bleeding and anticoagulant events.


Assuntos
Anticoagulantes/uso terapêutico , Coagulação Sanguínea/efeitos dos fármacos , Hemorragia/tratamento farmacológico , Antagonistas de Heparina/farmacologia , Heparina de Baixo Peso Molecular/antagonistas & inibidores , Protrombina/efeitos dos fármacos , Serina Endopeptidases/farmacologia , Animais , Hemorragia/induzido quimicamente , Masculino , Coelhos
13.
Int J Sports Med ; 32(7): 559-64, 2011 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-21567354

RESUMO

Erythropoietin promotes the production of red blood cells. Recombinant human erythropoietin is illicitly used to improve performance in endurance sports. Expression of the ERYTHROPOIETIN gene is negatively controlled by the transcription factor GATA-binding protein (GATA). Specific GATA inhibitors have recently been developed as novel drugs for the management of anemia. These drugs could, therefore, be illicitly used like recombinant human erythropoietin to improve performance in sports. To examine alterations in levels of plasma protein after administration of GATA inhibitors, proteomic analyses were conducted on mouse plasma samples treated with the potent GATA inhibitor K-11706. The analysis based on gel electrophoresis identified 41 protein spots differentially expressed when compared with normal plasma. Each spot was identified with liquid chromatography coupled to tandem mass spectrometry and 2 of them, fetuin-B and prothrombin, were verified by Western blotting. The results showed that the expression of fetuin-B in mice plasma was increased by K-11706, but not by recombinant human erythropoietin or hypoxia. These results suggest the potential of proteomic-based approaches as tools to identify biomarkers for the illegal use of novel drugs (e.g., GATA inhibitors). Also, fetuin-B could be a sensitive marker for the detection of abuse of GATA inhibitors.


Assuntos
Fatores de Transcrição GATA/antagonistas & inibidores , Proteômica/métodos , Animais , Biomarcadores/sangue , Western Blotting , Cromatografia Líquida , Doping nos Esportes , Eletroforese em Gel de Poliacrilamida , Eritropoetina/farmacologia , Fetuína-B , Regulação da Expressão Gênica/efeitos dos fármacos , Humanos , Masculino , Camundongos , Camundongos Endogâmicos ICR , Protrombina/efeitos dos fármacos , Protrombina/genética , Protrombina/metabolismo , Proteínas Recombinantes , Detecção do Abuso de Substâncias/métodos , Espectrometria de Massas em Tandem , alfa-Fetoproteínas/efeitos dos fármacos , alfa-Fetoproteínas/genética , alfa-Fetoproteínas/metabolismo
14.
J Am Acad Dermatol ; 63(4): 602-6, 2010 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-20675014

RESUMO

BACKGROUND: Cutaneous polyarteritis nodosa (CPN) is an uncommon disorder that can be difficult to manage effectively. We have previously suggested that CPN might be associated with the presence of anti-phosphatidylserine-prothrombin complex (anti-PS/PT) antibodies, members of the antiphospholipid antibody family. OBJECTIVE: To evaluate clinical manifestations and effective treatments of CPN. METHODS: We conducted a retrospective analysis of three patients with CPN who responded to warfarin therapy. IgG and IgM anti-PS/PT antibodies were measured with a specific enzyme-linked immunosorbent assay. RESULTS: There was a dramatic improvement in our three CPN patients following warfarin therapy adjusted to a target international normalized ratio (INR) of about 3.0. Active disease progression was halted by sustained warfarin therapy during which the patients experienced resolution of their skin manifestations. LIMITATIONS: A small number of cases were studied and the study design was retrospective. CONCLUSION: We propose that warfarin therapy at a target INR of roughly 3.0 could be effective for treating patients with CPN. We further believe that treatment with warfarin led to the effective attenuation of anti-PS/PT antibodies related to prothrombin, and improved the symptoms in our CPN patients.


Assuntos
Anticoagulantes/uso terapêutico , Úlcera da Perna/tratamento farmacológico , Poliarterite Nodosa/tratamento farmacológico , Varfarina/uso terapêutico , Adulto , Biópsia por Agulha , Relação Dose-Resposta a Droga , Esquema de Medicação , Ensaio de Imunoadsorção Enzimática , Feminino , Seguimentos , Humanos , Imuno-Histoquímica , Coeficiente Internacional Normatizado , Úlcera da Perna/etiologia , Úlcera da Perna/patologia , Pessoa de Meia-Idade , Poliarterite Nodosa/complicações , Poliarterite Nodosa/patologia , Protrombina/efeitos dos fármacos , Protrombina/metabolismo , Estudos Retrospectivos , Amostragem , Índice de Gravidade de Doença , Resultado do Tratamento , Cicatrização/efeitos dos fármacos , Adulto Jovem
15.
Menopause ; 17(6): 1122-7, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20613675

RESUMO

OBJECTIVE: Although the route of estrogen administration is known to be an important determinant of the thrombotic risk among postmenopausal women using hormone therapy, recent data have shown that norpregnane derivatives but not micronized progesterone increase venous thromboembolism risk among transdermal estrogens users. However, the differential effects of progesterone and norpregnanes on hemostasis have not yet been investigated. METHODS: We set up a cross-sectional study among healthy postmenopausal women aged 45 to 70 years. The impact of activated protein C (APC) on endogenous thrombin potential was investigated in the plasma samples of 108 women who did not use any hormone therapy (n = 40) or who were treated with transdermal estrogens combined with micronized progesterone (n = 30) or norpregnane derivatives (n = 38). RESULTS: After exclusion of women with factor V Leiden and/or G20210A prothrombin gene mutations, there was no significant change in APC sensitivity among women who used transdermal estrogens combined with micronized progesterone compared with nonusers. Women using transdermal estrogens combined with norpregnanes were less sensitive to APC than were nonusers (P = 0.003) or users of transdermal estrogens combined with micronized progesterone (P = 0.004). In addition, prothrombin fragment 1 + 2 concentration was higher in users of transdermal estrogens plus norpregnanes than in nonusers (P = 0.004). Other hemostatic parameters did not vary significantly across the different subgroups. CONCLUSIONS: Transdermal estrogens combined with norpregnanes may induce APC resistance and activate blood coagulation. These results provide a biological support to epidemiological data regarding the potential thrombogenic effects of norpregnanes. However, these findings need to be confirmed in a randomized trial.


Assuntos
Resistência à Proteína C Ativada/etiologia , Terapia de Reposição de Estrogênios/efeitos adversos , Estrogênios/administração & dosagem , Hemostasia/efeitos dos fármacos , Norpregnanos/administração & dosagem , Pós-Menopausa/sangue , Progestinas/administração & dosagem , Resistência à Proteína C Ativada/sangue , Administração Cutânea , Idoso , Estudos Transversais , Quimioterapia Combinada , Estrogênios/efeitos adversos , Feminino , Humanos , Modelos Lineares , Pessoa de Meia-Idade , Norpregnanos/efeitos adversos , Fragmentos de Peptídeos/sangue , Fragmentos de Peptídeos/efeitos dos fármacos , Progestinas/efeitos adversos , Protrombina/efeitos dos fármacos , Trombina/biossíntese , Trombina/efeitos dos fármacos
17.
Am Heart J ; 158(5): 726-33, 2009 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-19853689

RESUMO

BACKGROUND: Currently recommended anticoagulant agents used in the setting of percutaneous coronary intervention (PCI) inhibit, with varying degrees of intensity, 2 critical targets (factor Xa and/or IIa) of the coagulation cascade, yet they carry significant limitations. M118-a novel, rationally engineered heparin-provides consistent anti-Xa and anti-IIa activity with a constant anti-Xa:anti-IIa ratio over time. M118 also combines the desired anticoagulant effects of unfractionated heparin with the beneficial attributes of low-molecular-weight heparin, and may represent the next generation of heparin therapy in patients diagnosed with acute coronary syndrome. STUDY DESIGN: The EMINENCE trial is a prospective, randomized, open-label, multicenter phase 2 study that will evaluate the safety and feasibility of M118 as an anticoagulant versus unfractionated heparin in subjects with stable coronary artery disease undergoing PCI. The primary end point of the study will be the combined incidence of clinical events defined as the composite of 30-day death, myocardial infarction, repeat revascularization, catheter thrombus, stroke, thrombocytopenia, bailout use of glycoprotein IIb/IIIa inhibitors, and major or minor bleeding. CONCLUSION: The EMINENCE trial will assess the safety and feasibility of M118 as an anticoagulant in the setting of PCI and will provide important information to determine the appropriate therapeutic range of activated clotting time for M118 and the appropriate dose or doses to be explored in a phase 3 clinical trial.


Assuntos
Anticoagulantes/administração & dosagem , Doença da Artéria Coronariana/tratamento farmacológico , Fator X/efeitos dos fármacos , Heparina de Baixo Peso Molecular/administração & dosagem , Protrombina/efeitos dos fármacos , Feminino , Humanos , Masculino , Projetos de Pesquisa , Resultado do Tratamento
19.
Chemotherapy ; 55(1): 28-35, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-18974646

RESUMO

BACKGROUND: Des-gamma-carboxy prothrombin (DCP) is a serum protein produced by hepatocellular carcinoma (HCC) cells in the absence of vitamin K. Serum and tissue DCP expressions are thought to reflect the biological malignant potential of HCC. Hence, we aimed to examine the efficacy of vitamin K(2) on the production of DCP as well as tumor cell growth and invasion. METHODS: Cell growth and viability were evaluated by 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide assay. The in vivo efficacy of vitamin K(2) was examined in nude mice bearing HCC cells. A 24-well transwell chamber was used to evaluate the motility and invasive ability of HCC cells. Levels of DCP in supernatant of cultures and in serum of mice were measured using an electrochemiluminescence immunoassay method. Western blot and immunohistochemical analysis were employed to evaluate the expression of DCP in HCC. RESULTS: Vitamin K(2) (2-40 muM) significantly decreased the levels of DCP production in supernatant of PLC/PRF/5 and HepG2 cells and in serum of nude mice bearing HCC xenografts. The inhibition of DCP was also observed using the assays of Western blot analysis in HCC cultures and immunohistochemical analysis in HCC xenografts in mice. As a result of administration of vitamin K(2), the capacity of HCC growth was inhibited and the invasion and migration of tumor cells were decreased. Furthermore, the inhibitory effects of HCC growth were also observed in vivo and the sensitivity was well correlated with the decrease of DCP in the serum of mice. CONCLUSION: Vitamin K(2) might suppress the growth and invasion of HCC cells via decrease of DCP.


Assuntos
Biomarcadores/metabolismo , Carcinoma Hepatocelular/metabolismo , Neoplasias Hepáticas/metabolismo , Precursores de Proteínas/metabolismo , Protrombina/metabolismo , Vitamina K 2/farmacologia , Animais , Western Blotting , Carcinoma Hepatocelular/patologia , Divisão Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Humanos , Neoplasias Hepáticas/patologia , Medições Luminescentes , Camundongos , Camundongos Nus , Invasividade Neoplásica , Precursores de Proteínas/efeitos dos fármacos , Protrombina/efeitos dos fármacos , Vitamina K 2/metabolismo
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